CASE REPORT | doi:10.20944/preprints201912.0170.v1
Subject: Medicine & Pharmacology, Dermatology Keywords: sphingomonas; gram-negative bacterial infection; skin disease; bacterial
Online: 12 December 2019 (10:01:35 CET)
Sphingomonas paucimobilis is an opportunist pathogen bacillus gram-negative aerobic with a rare occurrence. We present a case in an immunocompetent man successfully treated by surgical debridement, purulent drainage and with an associated course of antibiotics. A large necrotic infection, approximately 5 cm x 3 cm, in a 74-year-old man was identified. Empirical antibiotic therapy with ciprofloxacin 400mg EV 12/12 hours, associated with clindamycin 600mg EV 6/6 hours and pain control was done through dipyrone 1gr, tramadol 400 mg. Deep venous thrombosis was prevented through the prescription of enoxaparin 40mg subcutaneous once a day during hospitalization. The case was well illustrated with pictures throughout treatment. Complete healing was achieved after 90 days. Herein, we present a case of cutaneous contamination. The presented case is the third cutaneous contamination case reported in the literature and the first reported case in the Amazonia region in Brazil.
ARTICLE | doi:10.20944/preprints202207.0149.v1
Subject: Medicine & Pharmacology, Pathology & Pathobiology Keywords: clinical S.aureus; skin carriage; geriatric-MRSA pneumonia; endogenous-S.aureus
Online: 11 July 2022 (04:33:22 CEST)
The changing epidemiology of Staphylococcus aureus has created several gaps in its population structure and emergence of strains. Two global shifts in the aftermath of the past methicil-lin-resistant S. aureus (MRSA) pandemic are: a rise in healthcare-associated infections and evolu-tion of cutaneous and soft tissue infections with high morbidities and mortalities. Furthermore, bitter lessons from COVID-19 showed S. aureus necrotizing-pneumonia and skin conditions ag-gravating Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) and Monkeypox manifestations. Limited data and paucity of high-quality evidence exist for many key clinical questions. Using clinical microbiology, molecular characterization, hospital data on age and in-fection sites, and antibiograms, we have investigated S. aureus infection patterns. We showed that age-specific distribution in both intensive care unit (ICU) and non-ICU revealed highest infection rates (94.7%) in senior-patients >50 years; most were MRSA (81.99%). However, specific distribu-tions of geriatric MRSA and MSSA rates were 46.5% and 4.6% in ICU and 35.48% and 8.065% in non-ICU, respectively. Intriguingly, age groups 0-20 years showed uniquely similar MRSA pat-terns in ICU and non-ICU patients (13.9%, 9.7%, respectively) and MSSA in ICU (11.6%). In age groups 20-50 years, MRSA were 2-fold in non-ICU (35%) than ICU (18.6%). Interestingly, highly significant association was found between infection-site and age-groups (P-value .000). Skin in-fections remained higher in all ages; pediatrics 32.14%, adults 56%, and seniors 25% while res-piratory infections were lower in pediatrics (14.3%) and adult 17%), and highest in seniors (38%). Blood and “other” sites in pediatrics recorded (28.6%; 25%, respectively), slightly lower in adults (18.6%; 8.6%) and seniors (14%); 22.8%), respectively. Further, significant association existed between infection-site and MRSA (Chi-Square Test, P-value .002). The common cutaneous infec-tions across all age-groups and the significant association of MRSA to geriatric-respiratory infec-tions have a high potential for skin-carriage as reservoir for endogenous infection. The similar frequencies of both lineages in youth in all settings imply MSSA-carriage as potential evolutionary origins for MRSA. These findings have important clinical implications for strategic planning in patient management and S. aureus control particularly in age-specific infections and vigilance for potential viral coinfections.
Subject: Life Sciences, Microbiology Keywords: skin microbiome; skin microbiome biodiversity; biodiversity; skin ecosystem; skin allergy epidemic; benchmark skin health values; skin bacteria; 21st century skin ailments; measure skin health; healthy skin ecosystem; healthy skin bacteria; damaged skin bacteria;
Online: 18 June 2020 (12:40:57 CEST)
A catastrophic loss of microbial biodiversity on the skin has led to alarming increase in the prevalence of allergies and long-term damage to the skin, which could also have damaging knock on effects to overall health. This study uses 50 human participants, to obtain an average (benchmark) value for the biodiversity of ‘healthy’ western skin, which is crucial in updating our 2017 skin health measuring mechanism to use standardised methodology. Previous work with a larger sample size was unsatisfactory for use as a benchmark due to its use of different and outdated diversity indices. We also investigated the effect of age and sex, two known skin microbiome affecting factors. Although no statistical significance is seen for age- and sex- related changes in diversity, there appear to be changes related to age which elaborates on previous work which used larger, more general age ranges. Our study indicates adults age 28-37 have highest diversity, and age 48-57 the lowest. Crucially, because of this study we are now able to update the skin health measuring mechanism from our 2017 work. This will aid diagnostic assessment of susceptibility to cutaneous conditions or diseases, and treatment. Testing any human subject will be rapidly improved by obtaining future benchmark diversity values for any age, sex, body site and area of residence, to which they can be compared. This improvement means we can also more accurately investigate the ultimate question: What factors in the western world are a main cause of the skin allergy epidemic? This could lead to future restriction of certain synthetic chemicals or products found to be particularly harmful to the skin.
ARTICLE | doi:10.20944/preprints202211.0495.v1
Subject: Mathematics & Computer Science, Artificial Intelligence & Robotics Keywords: skin classification; skin detection; skin segmentation; skin database; neural networks
Online: 28 November 2022 (05:16:35 CET)
Skin detection, the process of distinguishing between skin and non-skin regions in a digital image, is widely used in a variety of applications ranging from hand gesture analysis to body part tracking to facial recognition. Skin detection is a challenging problem that has received a lot of attention from experts and proposals from the research community in the context of intelligent systems, but the lack of common benchmarks and unified testing protocols has hampered fairness among approaches. Comparisons are very difficult. Recently, the success of deep neural networks has had a major impact on the field of image segmentation detection, resulting in various successful models to date. In this work, we survey the most recent research in this field and propose fair comparisons between approaches using several different datasets. The main contributions of this work are: (i) a comprehensive literature review of approaches to skin color detection and a comparison of approaches that may help researchers and practitioners choose the best method for their application; (ii) a comprehensive list of datasets that report ground truth for skin detection; (iii) a framework for evaluating and combining different skin detection approaches. Moreover, we proposed an ensemble of convolutional neural networks and transformers that obtains state of the art performance. All the code is made publicly available at https://github.com/LorisNanni
ARTICLE | doi:10.20944/preprints201703.0227.v1
Subject: Medicine & Pharmacology, Dermatology Keywords: biodiversity; skin allergy; benchmark skin health values; effect of synthetic cosmetics on skin; 21st century skin ailments; measure skin health; healthy skin ecosystem; healthy skin bacteria; damaged skin bacteria; perfect skin
Online: 31 March 2017 (08:52:14 CEST)
There is a skin allergy epidemic in the western world, and the rate of deterioration has increased significantly in the past 5-10 years. It is probable that there are many environmental contributing factors, yet some studies have linked it primarily to the rise in the use of synthetic chemical ingredients in modern cosmetics. Our challenge, therefore, was to find a mechanism to determine the effect these substances have on skin health, and whether they really are a primary cause of long term damage to the skin. The first problem is the lack of any definitive way to measure skin health. Motivated by the overwhelming evidence for a link between deficient gut flora and ill health, we decided to look at whether our skin microbiota could similarly be used as an indicator of skin health. Our research illustrates how it is microbiota diversity alone that can predict whether skin is healthy or not, after we revealed a complete lack of conclusive findings linking the presence or abundance of particular species of microbe to skin problems. This phenomenon is replicated throughout nature, where high biodiversity always leads to healthy ecosystems. ‘Caveman’ skin, untouched by modern civilisation, was far different to ‘western’ skin and displayed unprecedented levels of bacterial diversity. The less exposed communities were to western practices, the higher the skin diversity, which is clear evidence of an environmental factor in the developed world damaging skin. For the first time we propose benchmark values of diversity against which we can measure skin to determine how healthy it is. This gives us the ability to be able to predict which people are more likely to be prone to skin ailments, and start to test whether cosmetic ingredients and products are a main cause of the skin allergy epidemic.
REVIEW | doi:10.20944/preprints202010.0223.v1
Subject: Medicine & Pharmacology, Allergology Keywords: Epstein-Barr virus; hydroa vacciniforme; lymphoproliferative disorders; photodermatosis; sunlight; skin; ultraviolet radiation
Online: 12 October 2020 (10:30:05 CEST)
Hydroa vacciniforme (HV) is a rare form of photosensitivity disorders in children and is frequently associated with Epstein-Barr virus (EBV) infection, whereas HV-like lymphoproliferative disorders (HVLPD) describe a spectrum of EBV-associated T-cell or NK-cell lymphoproliferations with HV-like cutaneous manifestations, including EBV-positive HV, atypical HV, and HV-like lymphoma. Classic HV occurs in childhood with vesiculopapules on sun-exposed areas, which is usually induced by sunlight and ultraviolet irradiation, and mostly resolves by early adult life. Unlike classic HV, atypical or severe HV manifests itself as recurrent papulovesicular eruptions in sun-exposed and sun-protected areas associated occasionally with facial edema, fever, lymphadenopathy, oculomucosal lesions, gastrointestinal involvement, and hepatosplenomegaly. Notably, atypical or severe HV may progress to EBV-associated systemic T-cell or natural killer (NK)-cell lymphoma after a chronic course. Although rare in the United States and Europe, atypical or severe HV and HV-like lymphoma are predominantly reported in children from Asia and Latin America with high EBV DNA levels, low numbers of NK cells, and T cell clones in the blood. In comparison with the conservative treatment used for patients with classic HV, systemic therapy such as immunomodulatory therapy is recommended as the first-line therapy for patients with atypical or severe HV. This review aims to provide an integrated, overview of current evidence and knowledge of HV and HVLPD to elucidate the pathophysiology, practical issues, environmental factors, and the impact of EBV infection.
ARTICLE | doi:10.20944/preprints201812.0177.v1
Subject: Life Sciences, Microbiology Keywords: skin allergy epidemic; skin microbiome; skin microbiome diversity; effect of synthetic cosmetics on skin; biodiversity; synthetic ingredients in modern cosmetics; skin health; healthy skin bacteria; damaged skin bacteria
Online: 17 December 2018 (07:27:34 CET)
As described in previous work, the use of synthetic chemical ingredients in modern cosmetics is postulated to be a cause of damage to the skin microbiome. The discovery that biodiversity on the human skin is currently the only reliable indicator of skin health, meant that for the first time, a mechanism to test for healthy skin was possible. Using this mechanism and in collaboration with The Medical University of Graz, who carried out the independent study, this work aimed to help answer whether modern day synthetic cosmetics are a main cause of long term damage to the skin microbiome. Thirty-two human participants tested three different face washes for their effect on the skin’s microbial diversity, along with skin pH, moisture and TEWL (trans-epidermal water loss), washing twice a day for four weeks. The upper volar forearm of the volunteers was swabbed at the beginning, two weeks in and end (four weeks). 16S rRNA sequencing was used. One leading ‘natural’ brand full of synthetic ingredients, a leading synthetic brand and a 100% natural face wash were used. Results give the first indications of a link between synthetic ingredients in a cosmetics product, and its effect on skin microbiome biodiversity. It paves the way for future studies on the topic with a larger sample group, longer test period and standardised methodology to create a universal standard for testing the health of skin using benchmark diversity values. This can be used in the future to test the effectiveness of cosmetics or ingredients on skin health, leading to the banning of products proven to harm the skin’s natural environment.
REVIEW | doi:10.20944/preprints202103.0229.v1
Subject: Life Sciences, Biochemistry Keywords: skin regeneration; wound healing; skin stem cells; skin vascularization; 3D printing.
Online: 8 March 2021 (15:26:04 CET)
In the past decades, regenerative medicine applied on skin lesions has been a field of constant improvement for both human and veterinary medicine. The process of healing cutaneous wound injuries implicates a well-organized cascade of molecular and biological processes. However, sometimes the normal process fails and can result in a chronic lesion. In addition, wounds are considered an increasing clinical impairment, due to the progressive ageing of the population, as well as the prevalence of concomitant diseases, such as diabetes and obesity, that represent risk aggravating factors for the development of chronic skin lesions. Stem cells regenerative potential has been recognized worldwide, including towards skin lesion repair, Tissue engineering techniques have long been successfully associated with stem cell therapies, namely the application of 3D bioprinted scaffolds. With this review we intend to explore several stem cell sources with promising aptitude towards skin regeneration, as well as different techniques used to deliver those cells and provide a supporting extracellular matrix environment, with effective outcomes. Furthermore, different studies are discussed, both in vitro and in vivo, towards their relevance in the skin regeneration field.
ARTICLE | doi:10.20944/preprints201901.0100.v1
Subject: Engineering, Other Keywords: Assessing efficacy of skin care products; PhabrOmeter; Artificial skin; Changes of skin attributes
Online: 10 January 2019 (14:02:58 CET)
Current instrumental technology in evaluating performance of skin care creams is still rather limited and there are no industrial standard testing equipment, method and performance specifications for it. In this paper, we report our attempt in using an instrument called PhabrOmeter for this purpose. PhabrOmeter is a commercialized instrument for sensory performance evaluation of textiles, leather, paper and nonwoven and has been designated by American Association of Textile Chemists and Colorists (AATCC) as a standard test method for textiles, AATCC TM 202 in 2013. By adopting artificial skin samples treated with skin care creams, we have developed a procedure to apply this instrument for evaluation of skin care creams from sample preparation, measurement to data analysis and interpretation. The results using commercial skin care creams to demonstrate the feasibility and advantages of this instrument are provided.
ARTICLE | doi:10.20944/preprints202210.0366.v1
Subject: Mathematics & Computer Science, Other Keywords: skin segmentation; skin detection; computer vision; digital image processing
Online: 24 October 2022 (12:50:24 CEST)
A single paragraph of about 200 words maximum. For research articles, abstracts should give a pertinent overview of the work. We strongly encourage authors to use the following style of structured abstracts, but without headings: (1) Background: place the question addressed in a broad context and highlight the purpose of the study; (2) Methods: describe briefly the main methods or treatments applied; (3) Results: summarize the article’s main findings; (4) Conclusions: indicate the main conclusions or interpretations. The abstract should be an objective representation of the article, it must not contain results which are not presented and substantiated in the main text and should not exaggerate the main conclusions.
REVIEW | doi:10.20944/preprints201705.0064.v1
Subject: Physical Sciences, Optics Keywords: multispectral skin imaging; skin autofluorescence and photobleaching; photoplethysmography imaging
Online: 8 May 2017 (12:19:30 CEST)
Optical tissue imaging has several advantages over the routine clinical imaging methods, including non-invasiveness (does not change the structure of tissues), remote operation (avoids infection) and ability to quantify the tissue condition by means of specific image parameters. Dermatologists and other skin experts need compact (preferably pocket-size), self-sustained and easy-to-use imaging devices. The operational principles and designs of ten portable in-vivo skin imaging prototypes developed at the Biophotonics Laboratory of Institute of Atomic Physics and Spectroscopy, University of Latvia during the recent five years are presented in this paper. Four groups of imaging devices are considered. Multi-spectral imagers offer possibilities for distant mapping of specific skin parameters, so facilitating better diagnostics of skin malformations. Autofluorescence intensity and photobleaching rate imagers show a promising potential for skin tumor identification and margin delineation. Photoplethysmography video-imagers ensure remote detection of cutaneous blood pulsations and can provide real-time information on cardiovascular parameters and anesthesia efficiency. Multimodal skin imagers perform several of the above-mentioned functions by taking a number of spectral and video images with the same image sensor. Design details of the developed prototypes and results of clinical tests illustrating their functionality are presented and discussed.
REVIEW | doi:10.20944/preprints202210.0105.v1
Subject: Life Sciences, Microbiology Keywords: topical probiotics; skin microbiome; probiotics; biodiversity; microbiome; skin allergy; cosmetics
Online: 9 October 2022 (03:34:01 CEST)
In this paper we aim to help topical probiotics research and development achieve its potential as an incredible future solution for skin problems by investigating whether the current products on the market satisfy criteria for safe and effective use on the skin microbiome. As previously defined, this includes whether they use microbes known to be part of a healthy skin microbiome and in healthy amounts. In addition, we evaluate whether they contain live microbes, and therefore can be classified as probiotics according to the WHO’s definition. Using recent market analysis at least 84% of products do not contain live microbes. Of the products that appeared to use live microbes, they contained those used in research and development of probiotics for the gut. Due to the varying composition of each person’s microbiome, there is not a one size fits all probiotic solution. Personalisation of probiotics products is essential to satisfy the criteria for safe and effective use, but none of the products on the market, understandably, offer this. Upsetting the delicate ecosystem balance of the skin microbiome could have damaging effects and regulation could help to stop a loss of trust between consumers and cosmetics industry. Future work will perform an in-depth evaluation of the topical probiotics on the market in the EU, USA, and Canada. We will also investigate how to move the topic closer to achieving its potential by updating the criteria, including by discussing how to measure the success of a probiotic solution.
REVIEW | doi:10.20944/preprints202111.0043.v1
Subject: Medicine & Pharmacology, Dermatology Keywords: Skin Aging; Rejuvenation; Skin Cream; Retinoid formulation; RetileX-A; Vercilex
Online: 2 November 2021 (10:55:27 CET)
Skin ageing is a progressive but modifiable, multi-factorial disorder that involves all skin tissues. Pertaining to its wide range of physiological and psychosocial complications, skin ageing requires rigorous clinical attention. Topical retinoids and per-oral proteoglycans are promising, non-invasive, therapeutic modalities. To overcome the low bioavailability of conventional free retinoids, Nourella® cream with Retilex-A® (Pharma Medico, Aarhus, Denmark) was developed using a proprietary nano-encapsulation technology. The nano-encapsulation is a sophisticated ‘permeation/penetration enhancer’ that optimises topical drug delivery by increasing surface availability and net absorption ratio. Treatment adherence is also improved by minimising skin irritation. Interventional evidence supports the higher efficacy of Retilex-A® in improving skin thickness and elasticity compared with conventional free forms. It is also reported that the rejuvenating efficacy of Retilex-A® and tretinoin are comparable. Another skin anti-ageing approach is proteoglycan replacement therapy (PRT) with Vercilex®. Vercilex® in Nourella® tablet has the potential to ameliorate proteoglycan dysmetabolism in the aged skin by activating skin cells and improving collagen/elastin turnover. Replicated clinical trials evidenced that PRT can significantly enhance the density, elasticity and thickness of both intrinsically aged and photoaged skin. Evidently, Vercilex® and Retilex-A® share a range of bioactivities, which underlies their synergistic activity observed in a clinical trial. Dual therapy with Nourella® tablets and cream produced higher effect sizes on skin characteristics than monotherapy with each of the two treatments. In conclusion, Nourella® cream and tablets are safe and effective treatments for skin ageing; however, combining the two in a ‘dual skin rejuvenation system’ significantly improves treatment outcomes.
REVIEW | doi:10.20944/preprints202104.0036.v1
Subject: Life Sciences, Biochemistry Keywords: mast cells; innate immunity; host defense; skin; inflammatory skin disorders
Online: 1 April 2021 (17:44:17 CEST)
Mast cells (MCs) are best known as key effector cells of immediate type allergic reactions that may even culminate in life-threatening anaphylactic shock syndromes. However, strategically positioned at host-environment interfaces and equipped with a plethora of receptors, MCs also play an important role in the first line defense against pathogens. Their main characteristic, the huge amount of preformed pro-inflammatory mediators embedded in secretory granules, allow for a rapid response and initiation of further immune effector cell recruitment. The same mechanism, however, may account for detrimental overshooting responses. MCs are not only detrimental in MC-driven diseases, but also responsible for disease exacerbation in other inflammatory disorders. Focusing on the skin as the largest immune organ, we herein review both beneficial and detrimental functions of skin MCs all the way from skin barrier integrity via host defense mechanisms to MC-driven inflammatory skin disorders. Moreover, we emphasize the importance of IgE-independent pathways of MC activation and their role in sustained chronic skin inflammation and disease exacerbation.
REVIEW | doi:10.20944/preprints201807.0425.v1
Subject: Medicine & Pharmacology, Dermatology Keywords: hyperpigmentation; palpebral region; geographic skin differences; ethnic predisposition; skin disorder;
Online: 23 July 2018 (12:56:47 CEST)
POH (Peri Orbital Hyperpigmentation) represents a minor clinical entity that attracts immense aesthetic damages and it generates social integration difficulties. This review focuses on the etiopathogenic causes of this entity, differentiating and reclassifying this defect as having, on the one hand, genetic causes of melanic hyperproduction – for Fitzpatrick cutaneous phototypes IV and V – and, on the other hand, both genetic and acquired vascular causes, in individuals with light-coloured skin phototypes. Hence, there is a big difference in the field of pathogenic treatment, for the two entities. In addition, this study notes the direct relationship between skin aging and POH, especially for aquired vascular causes. In this reasoning, other aesthetic deficiencies of the skin in the palpebral area should be also considered, like: blepharochalasis, wrinkles, the anatomical causes of the lower eyelid shading, symmetrical or asymmetric suborbital oedema. All of these issues will complicate the therapeutic decision and subsidiary, the pharmaceutical advice. In this context, the review shows the guidelines for a honest councelling of the patients, pointing the efficiency limit for the topical pharmaceutical medication (depigmentants, exfoliants) versus the necessity of minimally invasive or/ and surgical treatments (in blefarochalasis).
ARTICLE | doi:10.20944/preprints201711.0150.v1
Subject: Biology, Anatomy & Morphology Keywords: radiation; skin barrier; sebaceous gland; transepidermal water loss; skin pH
Online: 23 November 2017 (08:33:29 CET)
Abstract: Radiation-induced skin injury can be a serious cutaneous damage and have specific characteristics. Asymptomatic periods are classified as the latent stage. The skin barrier plays a critical role in the modulation of skin permeability and hydration and protects the body against a harsh external environment. However, an analysis on the skin barrier dysfunction against radiation exposure in the latent stage has not been conducted. Thus, we investigated whether skin barrier is impaired by irradiation in the latent stage and aimed to identify the molecules involved in skin barrier dysfunction. We analyzed skin barrier function and its components in SKH-1 mice that received 20 and 40 Gy local irradiation. Increased transepidermal water loss and skin pH were observed in the latent stage of the irradiated skin. Skin barrier components, such as structural proteins and lipid synthesis enzymes in keratinocyte, increased in the irradiated group. Interestingly, we noted sebaceous gland atrophy and increased serine protease and inflammatory cytokines in the irradiated skin during the latent period. This finding indicates that the main factor of skin barrier dysfunction in the latent stage of radiation-induced skin injury is sebaceous gland deficiency, which could be an intervention target for skin barrier impairment.
REVIEW | doi:10.20944/preprints202003.0293.v1
Online: 19 March 2020 (02:23:21 CET)
Recently scientific research began to shift their focus on looking at both the gut and the skin microbiota as having a reciprocal and integral relationship with one another, rather than assessing them as separate and unrelated fields. In the past five years, the field of microbial endocrinology emerged, which examines how our gut microbiota influences and modulates hormones. We’ve known for decades that hormones greatly affect the condition of the skin, and many skin conditions are often treated with oral hormonal therapy as means to internally treat skin conditions visible on the dermis. Now, a growing body research and discourse examining this triad of biological spheres – gut microbiota, skin microbiota, and the endocrine system – as interconnected rather than binary and unrelated. While there is ample research established and being conducted examining the gut-skin axis, the gut-brain axis, and the gut-hormone axis, through this paper I will review and synthesize some of the significant advancements in this emerging and inclusive field of science to suggest that the fields need to expand the axis and their modality for researching these fields as a connected whole in order to better understand the role of the microbiota in disease prevention as a whole.
REVIEW | doi:10.20944/preprints202212.0315.v1
Subject: Medicine & Pharmacology, Dermatology Keywords: Melasma; Treatment; Darker skin types; Fitzpatrick skin types IV-VI; mapping review
Online: 19 December 2022 (03:45:26 CET)
Melasma is a challenging chronic skin condition associated with hyperpigmentation and un-known etiology. This scoping review mapped evidence of available treatments and their effectiveness in darker skin types. A comprehensive, systematic online search was conducted in Scopus, PubMed, CINAHL Complete, Cochrane, ScienceDirect, and Web of Science Core Collection. All eligible titles were exported to an Endnote20 library. Thematic content analysis was performed to summarise data on current melasma treatments for darker skin types. The quality of included articles was appraised using the Mixed Methods Appraisal Tool (MMAT) 2018 version. A total of 2863 articles were retrieved from the databases, and 10 met the eligibility criteria following abstract and full-text screening. Our findings demonstrate that topical treatments, chemical peels, lasers, and tranexamic acid are common treatment modalities used in darker skin types. Although these treatments may be effective in the short term, they bring about un-desirable side effects and sometimes worsen or result in reoccurrences of melasma. Based on the evidence mapped, current treatment modalities are not suitable for darker skin types. There are very few studies conducted on individuals of African descent. Further research is necessary to investigate treatment interventions which may be user-friendly when dealing with darker skin types.
REVIEW | doi:10.20944/preprints201808.0058.v1
Subject: Medicine & Pharmacology, Pediatrics Keywords: infant; premature; pain; acupuncture; skin to skin contact; sucrose; massage; musical therapy; breastfeeding
Online: 3 August 2018 (04:09:31 CEST)
Pain is a major problem in sick newborn infants, especially for those needing intensive care. Pharmacological pain relief is the most commonly used but may be ineffective, have side effects, including long-term neurodevelopmental sequelae. The effectiveness and safety of alternative analgesic methods are ambiguous. The objective is to review the effectiveness and safety of non-pharmacological methods of pain relief in newborn infants and to identify those that are the most effective. PubMed and Google Scholar were searched using the terms: ‘infant’, ‘premature’, ‘pain’, ‘acupuncture’, ‘skin to skin contact’, ‘sucrose’ ‘massage’, ‘musical therapy’ and ‘breastfeeding’. We included 24 studies assessing different methods of non-pharmacological analgesic techniques. Most resulted in some degree of analgesia but many were ineffective and some were even detrimental. Sucrose, for example, was often ineffective but more effective than music therapy, massage, breast milk (for extremely premature infants) or non-invasive electrical stimulation acupuncture. There were also conflicting results for acupuncture, skin to skin care and musical therapy. Most non-pharmacological methods of analgesia provide some modicum of relief for preterm infants but none are completely effective and there is no clearly superior method. Study is also required to assess potential long-term consequences of any of these methods.
ARTICLE | doi:10.20944/preprints202205.0356.v1
Subject: Medicine & Pharmacology, Dermatology Keywords: Teledermatology; Teledermoscopy; skin cancer diagnosis
Online: 26 May 2022 (07:53:54 CEST)
Background Due to the COVID-19 pandemic, teledermoscopy has been increasingly used in the remote diagnosis of skin cancers. In a study conducted in 2020, we demonstrated a potential role of an inexpensive device (NurugoTM Derma) as a first triage to select the skin lesions that require a face-to-face consultation with dermatologists. Herein, we report the results of a novel study that aims to better investigate the performance of NurugoTM. Objectives i) verify whether the NurugoTM can be a communication tool between the General Practitioner (GP) and dermatologist in the first assessment of skin lesions; ii) analyze the degree of diagnostic-therapeutic agreement between dermatologists; iii) estimate the number of potentially serious diagnostic errors. Methods One hundred forty-four images of skin lesions were collected at the Dermatology Outpatient Clinic in Novara using a conventional dermatoscope (instrument F), the NurugoTM (instrument N), and the latter with the interposition of a laboratory slide (instrument V). The images were evaluated in-blind by four dermatologists, and each was asked to make a diagnosis and to specify a possible treatment. Results: Our data show that F gave higher agreement values for all dermatologists, concerning the real clinical diagnosis. Nevertheless, a medium/moderate agreement value was obtained also for N and V instruments and that can be considered encouraging and indicate that all examined tools can potentially be used for the first screening of skin lesions. The total amount of misclassified lesions was limited (especially with the V tool), with up to nine malignant lesions wrongly classified as benign. Conclusions NurugoTM, with adequate training, can be used to build a specific support network between GP and dermatologist or between dermatologists. Furthermore, its use could be extended to the diagnosis and follow-up of other skin diseases, especially for frail patients in emergencies such as the current pandemic context.
ARTICLE | doi:10.20944/preprints201809.0490.v1
Online: 25 September 2018 (15:43:11 CEST)
Background: Melatonin is a potent mitochondrial, cytoprotective and antioxidant molecule with potentially strong anti-aging properties. Topical melatonin has shown to improve the clinical signs of skin aging. Melatosphere™ is a new lipid-based delivery system able to improve stability and skin penetration of melatonin when used in topical formulations. No clinical studies, using objective instrumental data, are available so far regarding the positive effect of Melatosphere™ in improving wrinkles in women with mild-to-moderate skin aging. Study Aim: We evaluate, in an open prospective, evaluator-blinded trial, the effects on skin texture of 2 months treatment with a Melatosphere™ based cream. Subjects and Methods: 15 women aged >45 years with mild to moderate facial skin aging (Glogau score ≥2) participated in the trial, after their informed consent. An ANTERA 3D computer-assisted skin analysis evaluation for the assessment of coarse and fine wrinkles of the periorbital area and melanin content was performed at baseline and after two months of treatment. An evaluator-blinded Investigator Global assessment of skin elastosis, roughness, level of dyscromia, skin dryness and presence of actinic damage was also performed at the same time points using a 4-grade score from 0 (no sign) to 3 (severe sign). Results: At baseline the mean (SD) IGA score was 8.2(1.0). After 2 months the IGA score significantly decrease to 4.2(1.4) (49% reduction) (P=0.0007). ANTERA 3D evaluations showed a significant reduction in skin coarse and fine wrinkles volume in the target area of -31% and -18%, respectively. Melanin content was reduced significantly by -17%. Conclusion: Topical melatonin carried in Melatosphere improves in the short-term signs of skin aging evaluated clinically and by ANTERA 3D device in women with mild to moderate skin aging.
ARTICLE | doi:10.20944/preprints202009.0564.v1
Subject: Life Sciences, Other Keywords: air pollution; skin; nutraceutical; natural compound; polyphenols; antioxidant; skin barrier; anti-agein; clinical trial
Online: 24 September 2020 (04:38:10 CEST)
Repeated air pollution exposure is one of the major threats to skin health. Air pollution causes skin damage and accelerates skin ageing mainly through oxidative stress mechanisms. Since it is difficult to minimize skin exposure from air pollutants, especially in urban areas, strategies to protect the skin are needed. On the other hand, plant phenolic compounds have been found to be effective in attenuating cellular oxidative stress and inflammation induced by different air pollutants. Therefore, we conducted a 12-week randomized, placebo-controlled, double blind study to assess the efficacy of a polyphenol-enriched dietary supplement (comprised of olive leaf, lemon verbena, rosemary and Sophora japonica extracts) in reducing pollution-induced oxidative stress and in improving different skin parameters related to skin ageing of Caucasian and Asian volunteers living in a polluted urban European area (Milan). One hundred healthy women were recruited and randomized in the placebo or in the test dietary supplement treatment arms. To assess the efficacy of the dietary supplement, the total antioxidant capacity on saliva (FRAP) was determined, as well as the oxidative damage on skin (lipoperoxides content), the skin moisture (corneometry), the trans-epidermal water loss (Tewameter), the skin radiance and the skin colour, (spectrophotometry), the skin elasticity (cutometry), the skin sebum content (sebumeter), and the skin roughness (image analysis). As a result, both inter-group and intra-group analysis proved that the dietary supplement improved all clinical and biochemical monitored parameters, in both Caucasian and Asian individuals. In conclusion, the results of the study indicate a reduced oxidative stress-induced skin damage in both Asian and Caucasian women living in a polluted urban area.
ARTICLE | doi:10.20944/preprints201807.0274.v1
Subject: Life Sciences, Other Keywords: asymmetry; mean skin temperature; non-uniform; outdoor environment; physiological response; skin temperature; solar radiation
Online: 16 July 2018 (10:46:36 CEST)
Depending on human body conditions and environmental conditions, it is sometimes difficult to conduct subject experiments. In such cases, it is effective to use a thermal manikin. There are few studies that investigate the effect of the non-uniform and asymmetric outdoor thermal environment on the mean skin temperature. The purpose of this study is to clarify the influence of the non-uniform and asymmetric thermal radiation of short-wavelength solar radiation in an outdoor environment on the calculation of the mean skin temperature. The skin temperature of the front of the coronal surface, which was facing the sun and where the body received direct short-wavelength solar radiation, and the skin temperature of the rear of the coronal surface, which was in the shadow and did not receive direct short-wavelength solar radiation were respectively measured. The feet, upper arm, forearm, hand and lower leg, which are susceptible to short-wavelength solar radiation in a standing posture, had a noticeable difference in skin temperature between sites in the sun and in shade. The mean skin temperature of sites facing the sun was significantly higher than the mean skin temperature of those in the shade.
ARTICLE | doi:10.20944/preprints202009.0637.v1
Online: 26 September 2020 (13:44:40 CEST)
Malassezia is lipid-dependent commensal yeast of the human skin. The different culture media and skin sampling methods used to grow these fastidious yeasts are a source of heterogeneity in culture-based epidemiological study results. This study aimed to compare the performances of three methods of skin sampling, and two culture media for the detection of Malassezia yeasts by culture from the human skin. Three skin sampling methods, namely sterile gauze, dry swab and TranswabTM with transport medium, were applied on 10 healthy volunteers. Each sample was further inoculated onto either the novel FastFung medium or the reference Dixon agar for the detection of Malassezia spp. by culture. At least one colony of Malassezia spp. grew on 93/300 (31%) of the cultures, corresponding to 150 samplings. The positive culture rate was 67%, 18%, and 15% (P < 10-3), for samples collected with sterile gauze, TranswabTM, and dry swab, respectively. The positive culture rate was 62% and 38% (P < 0.003) by using the FastFung and the Dixon media, respectively. Our results showed that sterile gauze rubbing skin sampling followed by inoculation on FastFung medium should be implemented in the routine clinical laboratory procedure for Malassezia spp. cultivation.
Subject: Medicine & Pharmacology, General Medical Research Keywords: astaxanthin; antioxidant; skin; ultraviolet; photoaging; capillary
Online: 20 January 2020 (09:55:03 CET)
Abstract: Ultraviolet (UV) induces skin photoaging, which is characterized by thickening, wrinkling, pigmentation, and dryness. Astaxanthin, a ketocarotenoid from Haematococcus pluvialis, has been extensively studied with respect to its possible effect on skin health as well as UV protection. In addition, astaxanthin attenuates increases in the generation of reactive oxygen species (ROS) and capillary regression of skeletal muscle. In the present study, we investigated whether astaxanthin would protect UV-induced photoaging and capillary regression in the skin of HR-1 hairless mice. UV induces wrinkle formation, thickness and capillary regression in dermis of hairless mice and the administration of astaxanthin decreased the UV-induced wrinkle formation, skin thickness, and increase in collagen fibers in skin. Astaxanthin supplementation also inhibited the levels of ROS generation and attenuated the decreases in wrinkle formation, thickness and capillary number in the skin. We also found an inverse correlation between wrinkling and capillary number, and the photoaging associated with capillary regression in skin. These results suggest that astaxanthin can protect against photoaging caused by ultraviolet irradiation and the effects of astaxanthin in photoaging inhibition may be associated with the protection of capillary regression in skin.
Online: 6 August 2019 (12:33:31 CEST)
Data on the KIT mutation rate in skin melanoma in the central European region is missing. Accordingly, in a cohort of 79 double wild type (BRAF/NRAS) skin melanoma KIT mutation was assessed by Sanger sequencing of exons 9,11,13,17 and 18. In this skin melanoma cohort KIT mutation frequency was found to be 34/79 (43%) with a significantly higher rate in acrolentiginous melanoma (ALM) as compared to UV-induced common variants (20/34, 58.8% versus 14/45, 31.1%, p=0.014). Exon 11 was the most frequent mutation site (44.7%) followed by exon 9 (21.1%) equally characterizing UV-induced common histotypes and ALM tumors. KIT mutation hotspots were identified in exon 9 (c491/492), in exon 11 (c559,c572, c570), in exon 13 (c642), in exon 17 (c822) and in exon 18 (c853). The relatively high KIT mutation rate in skin melanoma in this central-European cohort justifies regular testing of this molecular target.
REVIEW | doi:10.20944/preprints201807.0615.v1
Subject: Medicine & Pharmacology, Dermatology Keywords: onchodermatitis; onchocercal skin disease; onchocerciasis; ivermectin
Online: 31 July 2018 (09:47:34 CEST)
Onchocerciasis causes debilitating pruritus and rashes as well as visual impairment and blindness . Prior to control measures, eye disease was particularly prominent in savanna areas of sub-Saharan Africa whilst skin disease was more common across rainforest regions of tropical Africa. Mass drug distribution with ivermectin is changing the global scene of onchocerciasis. There has been successful progressive elimination in Central and Southern American countries and the World Health Organization has set a target for elimination in Africa of 2025. This literature review was conducted to examine progress regarding onchocercal skin disease. PubMed searches were performed using keywords "onchocerciasis", "onchodermatitis" and "onchocercal skin disease" over the past eight years. Articles in English, or with an English abstract, were assessed for relevance, including any pertinent references within the articles. Recent progress in awareness of, understanding and treatment of onchocercal skin disease is reviewed with particular emphasis on publications within the past 5 years. The global burden of onchodermatitis is progressively reducing and is no longer seen in children in many formerly endemic foci.
ARTICLE | doi:10.20944/preprints202211.0133.v1
Subject: Medicine & Pharmacology, Dermatology Keywords: skin infection; antibiotics; quinolone; S. aureus; geriatrics
Online: 8 November 2022 (01:57:03 CET)
INTRODUCTION: Superficial cutaneous bacterial infections have a high incidence in geriatric patients. The most implicated pathogens are gram-positive cocci (Staphylococcus aureus, Streptococcus pyogenes) while gram-negative germs are also implicated. Resistances to common topical antibiotics (mupirocin, fusidic acid) require alternatives to gram-positive and gram-negative microorganisms.Ozenoxacin cream for topical use (non-fluorinated bactericidal quinolone), in other countries and with other galenics, is indicated in children older than 6 months and in adults as a treatment of superficial bacterial infections, such as acne. In Spain, ozenoxacin cream is indicated only for non-bullous impetigo; scientific evidence show effectiveness also in other superficial skin bacterial infections.A cases series of clinical use of ozenoxacin in bacterial superficial skin infections in geriatric patients (institutionalized or community dwelling) is presented.METHODS: Multicenter case series (March-August 2022) of bacterial superficial skin infections treated with ozenoxacin cream (10mg/g every 12h, 5days); data from medical records (controls: 1-3-5 days), after obtaining informed consent (use of data and images).RESULTS: Series of 28 patients (mean age: 84,79) from nine nursing homes and one outpatient geriatric service, including acute and subacute/chronic cases.In all cases treatment was ozenoxacin 10mg/g topical cream applied every 12 hours for 5 days according to medical prescription (except for one case in which 3 days were enough for complete healing and another case treated for 10 days).Results showed complete healing in all 20 acute cases and significant clinical improvement in all subacute/chronic cases (with complete healing in one of them). Professionals scored the effectiveness in acute cases as a mean 4.5 points (maximum score: 5, p<.0001) and in subacute/chronic cases as 3.8 points (p=.010).There was no skin irritation or other adverse effects in anyone of the patients, and clinical improvement of pain, itching and other symptoms was observed, suggesting an anti-inflammatory effect. DISCUSSION AND CONCLUSIONS: Our results seem to demonstrate the effectiveness and tolerability of ozenozacin cream in bacterial infections other than non-bullous impetigo. Ozenoxacin cream is indicated only for the treatment of non-bullous impetigo; however, it is also shown to be effective, both in the scientific evidence and in our case series, for other superficial bacterial skin infections, both acute and subacute/chronic, suggesting the opportunity for clinical studies with an experimental design to evaluate the findings of clinical practice and to be able to have a therapeutic alternative to compensate for the complications of the appearance of resistance.
Subject: Life Sciences, Biochemistry Keywords: skin aging; punicalagin; niosomes; UV radiation; collagen
Online: 24 March 2021 (17:35:18 CET)
Skin aging is one of the most common problems facing humanity. It occurs because of altering the balance between free radicals and antioxidants and increasing the amount of the reactive oxygen species (ROS) in skin cells, which leads to oxidative stress especially when exposed to UV radiation. Antioxidants can neutralize the harmful effects of ROS, and secondary plant metabolites can help protect against UV radiation. In this study, punicalagin was extracted from pomegranate and concentrations of total polyphenolics and flavonoids were determined and antioxidant activities measured. Punicalagin was loaded onto niosomes and its morphology and release were studied. An in vitro study was performed on human fibroblast cell line HFB4 cells with aging induced by H2O2 and UV radiation. Cell cycle arrest was studied and different genes (MMP3, Col1A1, Timp3, and TERT) involved in the skin aging process were selected to measure punicalagin's effect. Punicalagin succeeded in reducing the growth arrest of HFB4 cells, activated production of the Col1A1 and Timp3 genes, maintained collagen level, and lowered of MMP3. Punicalagin increased human TERT concentration in skin cells. Punicalagin is promising as a natural antioxidant to protect human skin from aging.
ARTICLE | doi:10.20944/preprints202103.0550.v1
Subject: Materials Science, Biomaterials Keywords: biocompatibility; carbon nanomaterials; graphite; phototherapy; skin disease.
Online: 22 March 2021 (15:47:21 CET)
Nanostructured carriers have been widely used in pharmaceutical formulations for dermatological treatment. They offer targeted drug delivery, sustained release, improved biostability, and low toxicity, usually presenting advantages over conventional formulations. Due to its large surface area, small size and photothermal properties, graphene oxide (GO) has the potential to be used for such applications. Nanographene oxide (GOn) presented average sizes of 197.6 ± 11.8 nm, and a surface charge of -39.4 ± 1.8 mV, being stable in water for over 6 months. 55.5 % of the mass of GOn dispersion (at a concentration of 1 mg mL-1) permeated the skin after 6 h of exposure. GOn dispersions have been shown to absorb near-infrared radiation, reaching temperatures up to 45.7 °C, within mild photothermal therapy temperature range. Furthermore, GOn in amounts superior to those which could permeate the skin were shown not to affect human skin fibroblasts (HFF-1) morphology or viability, after 24 h of incubation. Due to its large size, no skin permeation was observed for graphite particles in aqueous dispersions stabilized with Pluronic P-123 (Gt-P-123). Altogether, for the first time, GOn potential as a topic administration agent and for delivery of photothermal therapy has been demonstrated.
ARTICLE | doi:10.20944/preprints202006.0166.v2
Subject: Medicine & Pharmacology, Allergology Keywords: Tattoo; Tattoo ink; Oxidative stress; Phthalocyanine; Skin
Online: 2 December 2020 (11:05:29 CET)
Biomedical aspects of tattooing have been extensively discussed in literature, however pathophysiological effects of tattoo inks in the human body are still unexplored. Oxidative stress is considered responsible for the adverse effects of tattooing, however no experimental evidence for tattoo ink-related oxidative stress in the human body currently exists. The aim was to examine the effect of a blue tattoo on skin redox regulatory network (RRN) parameters in a single human subject. Skin surface oxidation-reduction potential (ORP) was analyzed with a PH60F flat probe. Interstitial and intracellular fluid enriched capillary blood from the tattoo and the control area was extracted and analyzed with I2/KI-stabilized microORP, nitrocellulose redox permanganometry (NRP), carbonato-cobaltate (III) formation-derived H2O2 dissociation rate assay, 1,2,3-trihydroxybenzene autoxidation assay, thiobarbituric reactive substances (TBARS) assay and 5,5,’-dithio-bis-(2-nitrobenzoic acid) (DTNB)-based determination of free thiol content in low molecular weight and protein precipitate fractions. Surface ORP analysis revealed a greater antioxidant capacity of tattooed skin in comparison with the control (CTR). Capillary blood analysis confirmed greater reductive capacity in the tattoo sample both by microORP (-4.33mV vs CTR) and NRP (+10.8%). Hydrogen peroxide dissociation rate (+11.8%), and protein sulfhydryl content (+8.5%) were increased, and lipid peroxidation (-15%) was reduced in the tattoo sample in comparison with the CTR. In this N-of-1 study, RRN of tattooed skin was shifted towards a more reductive state with all parameters indicating reduced levels of oxidative stress in comparison with nontattooed skin. The local antioxidant effect of copper(II) phthalocyanine provides one possible explanation of the observed effects.
REVIEW | doi:10.20944/preprints202002.0360.v1
Online: 25 February 2020 (05:23:17 CET)
Although man is still rapidly evolving, he has not co-evolved with all of the modern chemicals made by man, including those in cosmetic products. Care must be taken when formulating products so that commonly used ingredients, such as polyethylene glycol, can be substituted with safer ingredients to which man has adapted and that will not cause irritation and inflammation. This is especially important given that induction of skin inflammation will cause systemic inflammation. A review of the literature and of commercially available products was made to highlight techniques and products that remediate inflammation or induce inflammation. Many skin care products contain chemicals that induce irritation and inflammation that may lead to chronic, systemic inflammation. Well studied natural products, especially skin identical chemicals, may offer an advantage compared to recent man-made chemicals in cosmetic and topical formulations and help to reduce skin inflammation as well as skin derived systemic chronic inflammation.
ARTICLE | doi:10.20944/preprints201905.0135.v1
Subject: Biology, Animal Sciences & Zoology Keywords: Skin; Cell culture; Stem cells; Differentiation; Camel
Online: 10 May 2019 (15:04:59 CEST)
Elite camels often suffer from massive injuries. Thus, there is a pivotal need for a cheap and readily available regenerative medicine source. We isolated novel stem-like cells from camel skin and investigated their multipotency and resistance against various stresses. Skin samples were isolated from ears of five camels. Fibroblasts, keratinocytes, and spheroid progenitors were extracted. After separation of different cell lines by trypsinization, all cell lines were exposed to heat shock. Then, fibroblasts and dermal cyst-forming cells were examined under cryopreservation. Dermal cyst-forming cells were evaluated for resistance against osmotic pressure. The results revealed that resistance periods against trypsin were 1.5, 4, and 7 minutes for fibroblasts, keratinocytes, and spheroid progenitors, respectively. Furthermore, complete recovery of different cell lines after heat shock along with the differentiation of spheroid progenitors into neurons was observed. Fibroblasts and spheroid progenitors retained cell proliferation after cryopreservation. Dermal cyst-forming cells regained their normal structure after collapsing by osmotic pressure. The spheroid progenitors incubated in the adipogenic, osteogenic, and neurogenic media differentiated into the adipocytes, osteoblasts, and neurons, respectively. To the best of our knowledge, we isolated different unique cellular differons and stem-like cells from the camel skin and examined their multipotency for the first time.
ARTICLE | doi:10.20944/preprints201809.0607.v1
Subject: Chemistry, Applied Chemistry Keywords: Roasted Fish Skin, PAHs mutagenicity risk, Limonene
Online: 30 September 2018 (10:03:24 CEST)
Traditional edible barbecue products use with lemon juice not only make the barbecue more delicious but also reduce the risk of PAHs in the barbecue products. One of the major economics crops in Taiwan, the waste from citrus fruits was very tremendous mass. However, the peelings of citrus fruits are rich in essential oil, especially, the limonene is the major. Whether the anti-carcinogenesis activities of terpene, such as limonene, in citrus fruits essential oil extraction. This study to demonstrate the PAHs content in fish skin increased markedly after being roasted at 210℃ for 20 minutes and greater mutagenicity risk of roasted fish skin was observed by Ame's test. The reduction of mutagenicity risk of roasted fish skin, which the antimutagenic abilities of substances in descending order were limonene > cold pressure oil > lemon >grapefruit. The antimutagenicity rate and ability of the three extracts were limonene: 18–23%; cold-pressed lemon oil: 18–22%; and steam distilled lemon essential oil: 8–16%. The obvious anti- mutagenicity effects against the PAHs mutagenicity of roasted fish skins can be found in citrus fruits essential oil extraction.
Subject: Medicine & Pharmacology, Dermatology Keywords: topical steroid withdrawal; topical steroids; eczema; atopic dermatitis; skin microbiome; gut mi-crobiome; microbiome; biodiversity; skin allergy epidemic;
Online: 8 September 2021 (20:19:35 CEST)
We set up this preliminary study to evaluate one main question: could strengthening the microbiome have potential benefits for patients suffering with adverse effects after stopping long term topical steroid use? We aim to turn it into a much larger study if the results show promise. After commonly being prescribed for eczema, cessation of topical steroid use, especially after long periods of inappropriate use, can leave lasting adverse effects on the body and skin, known by some as topical steroid withdrawal (TSW). Furthermore, the subsequent withdrawal the body experiences when coming off the drug can leave lasting adverse effects on the body and skin, known by some as topical steroid withdrawal (TSW). This preliminary study involved seven human participants suffering with skin problems associated with TSW who approached Dr. Anja Gijsberts-Veens of their own volition because they were interested in more natural recovery methods. Five completed the study in full. Progress in skin condition was tracked by self-assessed symptom severity questionnaires filled out at the beginning and end of the study. The skin microbiome was addressed by using a 100% natural product shown in previous work to significantly increase skin microbiome biodiversity. Three participants implemented dietary changes and supplementation in response to guidance after fecal sample analysis to improve their gut health and biodiversity. The average improvement in skin symptoms for all participants was 40% and average symptom improvement ranged from 14% for Patient 5 to 92% for Patient 1. On average, the participants saw an improvement in 85% of their symptoms and a stagnation or regression in 11% and 4% respectively. We believe these results show enough promise to warrant expansion of this research to use a larger sample size, preferably 50+ participants, in future work. We also aim to swab the skin of participants to assess the effect on the skin microbiome from skin and gut treatments, as well as including more in-depth analysis of skin and gut microbiomes.
ARTICLE | doi:10.20944/preprints202301.0497.v1
Subject: Biology, Other Keywords: matrix metalloproteinases; skin fibrosis; gene expression; laser therapy
Online: 27 January 2023 (07:17:38 CET)
Matrix metalloproteinases (MMPs) are often considered biomarkers of skin fibrosis. At the early stages of the pathological process, an elevation of their enzymatic activity causes significant changes in the composition of the extracellular matrix. MMPs secreted by immune cells facilitate their migration to the site of damage. Then, the immune cells eliminate the affected cells and biomolecules. Moreover, bidirectional changes in the activity of proteolytic enzymes, including MMPs, accompany wound healing. This study aimed to assess changes in the expression of Mmp2, Mmp3, and Mmp9 after treating the mice with laser therapy using the experimental model of bleomycin-induced skin fibrosis. Using immunohistochemistry, we characterized the histological features of scarred skin. We also analyzed changes in the expression of MMPs using real-time polymerase chain reaction before and after the irradiation with laser. We showed that treatment of the mice with CO2 laser partially normalized the histological features of scarred skin. We also noticed a decrease in the expression of Mmp2, Mmp3 (both p < 0.05), and Mmp9 (p = 0.065) during scar healing. The obtained results suggest that normalization of skin homeostasis requires a control of MMPs activities via induction of their genes.
ARTICLE | doi:10.20944/preprints202210.0168.v1
Subject: Medicine & Pharmacology, Pharmacology & Toxicology Keywords: diaper; polycyclic aromatic hydrocarbons; skin cancer; neurobehavioral changes
Online: 12 October 2022 (09:55:13 CEST)
In September 2021, the European Chemicals Agency evaluated a dossier for restricting polycyclic aromatic hydrocarbons (PAHs) in infant diapers and concluded that risks were not demonstrat-ed because of inconclusive exposure data. To fill this gap, we measured the 16 priority PAHs of the U.S. Environmental Protection Agency in the diaper core of four brands and in the sheets and fastening tapes of six brands of commercially available diapers. Health risks were conservatively assessed by assuming that dermally absorbed PAHs can cause both local (skin cancer) and sys-temic critical effects (neurobehavioral changes). Total concentrations of PAHs in diaper core and top sheet, the only significant contributors to skin exposure, averaged 34.5 μg/kg and 66.8 μg/kg, respectively. Excess skin cancer risks and hazard quotients for neurobehavioral effects calculated with the daily dose of total PAHs from combined diaper core and top sheet averaged 1.4 x 10-7 and 1.19 x 10-2, respectively. The median daily dose of total PAHs and of its ben-zo[a]pyrene-equivalent from breast milk estimated worldwide are 171 and 30 times greater than that from combined diaper core and top sheet, respectively. Altogether these findings indicate that trace levels of PAHs found in infant diapers are unlikely to pose health risks.
COMMUNICATION | doi:10.20944/preprints202210.0124.v1
Subject: Medicine & Pharmacology, Sport Sciences & Therapy Keywords: microbiome; skin microbiome; sports recovery; sports performance; cosmetics
Online: 10 October 2022 (11:13:00 CEST)
This short communication reports on the initial results of a much larger, ongoing project, the aim of which is to investigate the question: could the skin microbiome, just like the gut microbiome, play a role in sports recovery and performance – and if so, could this role be as significant a one as that played by the gut microbiome? 17 high performance college athletes addressed their skin microbiome by minimizing contact with synthetic chemicals and by using topical skin supplements, shown previously to significantly increase skin microbiome biodiversity, for two weeks after training. 76% said their skin softness improved, 35% said their muscle stiffness and recovery after sport improved, 12% said their sleep quality improved, and 100% said they would be likely to use skin supplements again. Future work will use hundreds of athletes.
ARTICLE | doi:10.20944/preprints202112.0236.v1
Subject: Medicine & Pharmacology, Oncology & Oncogenics Keywords: cat; cutaneous lymphocytosis; dog; immunohistochemistry; lymphoma; PARR; skin
Online: 14 December 2021 (13:01:19 CET)
Cutaneous lymphocytosis (CL) is an uncommon and controversial lymphoproliferative disorder described in dogs and cats. CL is generally characterized by a heterogeneous clinical presentation and histological features that may overlap with epitheliotropic lymphoma. Therefore, its neoplastic or reactive nature is still debated. Here, we describe clinicopathological, immunohistochemical and clonality features of a retrospective case series of 19 cats and 10 dogs with lesions histologically compatible with CL. In both species, alopecia, erythema and scales were the most frequent clinical signs. Histologically, a dermal infiltrate of small to medium-sized lymphocytes, occasionally extending to the subcutis, was always identified. Conversely, when present, epitheliotropism was generally mild. In cats, the infiltrate was consistently CD3+; in dogs, a mixture of CD3+ and CD20+ lymphocytes was observed only in 4 cases. The infiltrate was polyclonal in all cats, while BCR and TCR clonal rearrangements were identified in dogs. Overall, cats had a long-term survival (median overall survival=1080 days) regardless of the treatment received, while dogs showed a shorter and variable clinical course, with no evident associations with clinicopathological features. In conclusion, our results support a reactive nature of the disease in cats, associated with prolonged survival; despite a similar histological picture, canine CL was associated with a more heterogeneous lymphocytic infiltrate, clonality results, and response to treatment.
ARTICLE | doi:10.20944/preprints202005.0500.v1
Subject: Medicine & Pharmacology, Dermatology Keywords: skin microbiome; skincare; cosmetic products; ecobiology; microbiome friendly
Online: 31 May 2020 (20:12:40 CEST)
Background: Skincare products are used daily to maintain a healthy skin (cleansing, moisturizing, protecting…), but their impact on this first layer, which corresponds to the skin microbiome, is still poorly understood. Preserving natural resources and mechanisms of the skin ecosystem is essential; an original approach based on these premises, called ecobiology, has recently emerged in skincare. Ecobiology considers the skin as an ever-evolving ecosystem which hosts human and microbial cells that interact together with their environment. In this context, we evaluated the impact on the skin microbiome of three types of leave-on face skincare products: a hydrophilic sterile solution, a micellar solution, and an oil-in-water emulsion. Materials and Methods: The individual microbial profiles of 20 Caucasian females were investigated. Samples were obtained twenty-four hours and four days following a daily application of the skincare products versus control area where no product was applied. To analyze the bacterial diversity and abundance of skin microbiome, a 16SrRNA gene sequencing was performed using the Illumina MiSeq platform. Results: Our results confirm the overall diversity of skin microbiome as previously observed and notably reveal the prevalence of Cutibacterium spp. and Staphylococcus spp. on sebaceous site (the back). Bacterial diversity and abundance were not affected by the products either twenty-four hours or four days after application, as indicated by comparison with the control. Moreover, no dissimilarity was observed between the three products versus their control, neither between each product. Conclusions: These preliminary results demonstrated for the first time that three different types of leave-on face skincare products such as a hydrophilic sterile solution, a micellar solution, and an emulsion have no impact on skin microbiome and can be considered as “microbiome friendly”.
ARTICLE | doi:10.20944/preprints201910.0305.v1
Online: 27 October 2019 (11:04:31 CET)
Collagen type I production decreases with aging, leading to wrinkles and impaired skin function. Prostaglandin E2 (PGE2), a lipid-derived signaling molecule produced from arachidonic acid by cyclo-oxygenase, inhibits collagen production and induces matrix metallopeptidase 1 (MMP1) expression by fibroblasts in vitro. PGE2-induced collagen expression inhibition and MMP1 promotion are aging mechanisms. This study investigated the role of E-prostanoid 1 (EP1) in PGE2 signaling in normal human dermal fibroblasts (NHDFs). When EP1 expression was inhibited by EP1 small interfering RNA (siRNA), there were no significant changes in messenger RNA (mRNA) levels of collagen, type I, alpha 1 (COL1A1)/MMP1 between siRNA-transfected NHDFs and siRNA-transfected NHDFs with PGE2. This result showed that EP1 is a PGE2 receptor. Extracellular signal-regulated kinase 1/2 (ERK1/2) phosphorylation after PGE2 treatment significantly increased by ~2.5 times. In addition, PGE2 treatment increased the intracellular Ca2+ concentration in NHDFs. These results indicated that PGE2 is directly associated with EP1 pathway–regulated ERK1/2 and inositol trisphosphate (IP3) signaling in NHDFs.
ARTICLE | doi:10.20944/preprints201908.0178.v1
Subject: Life Sciences, Molecular Biology Keywords: DHA; reconstructed human models; filaggrin; skin barrier; inflammation
Online: 16 August 2019 (08:17:51 CEST)
Atopic dermatitis (AD) is a chronic inflammatory skin disease, which can cause skin barrier function damaged. Although co-incubation with docosahexaenoic acid (DHA) exerts a positive effect in deficient skin model, there is no study to investigate the effects of topical treatment with DHA in inflammatory reconstructed human epidermis (RHE) model. The effects of DHA on monolayer normal human epidermal keratinocyte (NHEK) cells were evaluated via CCK-8, qPCR and ELISA. The skin related barrier function was assessed by hematoxylin-eosin (HE) staining, western blot (WB), Immunohistofluorescence (IF) and ELISA in normal and inflammatory RHE models. DHA upregulated filaggrin and loricrin expression at mRNA levels in addition to suppress overexpression of TNF-α，IL-1α and IL-6 stimulated by poly I:C plus LPS (stimulation cocktail) in cultured NHEK cells. After topical treatment with DHA, cocktail induced inflammatory characteristics of skin diseases including barrier morphological, differentiation proteins and TSLP secretion, which were alleviated in RHE models. Supplementation with DHA can improved related barrier function and have anti-inflammation effects in monolayer keratinocytes and RHE models, which indicated that DHA may have a potential value for the treatment of inflammation-associate skin diseases.
REVIEW | doi:10.20944/preprints201810.0772.v1
Subject: Medicine & Pharmacology, Dermatology Keywords: Marine algae; Carbohydrates; Oligosaccharides; Monosaccharides; Skin health; Cosmeceuticals
Online: 1 November 2018 (18:19:37 CET)
Marine algae have been considered as abundant source of bioactive compounds with cosmeceutical potential. Recently, a great deal of interest has focused on the health-promoting effects of marine bioactive compounds. Carbohydrate is a major and abundant constitute of marine algae that have been utilized in cosmetic formulations, such as moisturizing and thickening agents. In addition, marine carbohydrates have been suggested as promising bioactive biomaterials for various skin beneficial properties, such as anti-oxidant, anti-melanogenic and anti-skin aging. Therefore, marine algae carbohydrates have potential of skin health benefits for value-added cosmeceutical application. The present review focused on the various biological capacities and potential skin health benefits of bioactive marine carbohydrates.
REVIEW | doi:10.20944/preprints201711.0204.v1
Subject: Medicine & Pharmacology, Pediatrics Keywords: burns; treatment; pediatric; autograft; biological skin substitute; thermal
Online: 30 November 2017 (14:12:10 CET)
Burns is a pervasive and oppressive basic care issue. In children, burn injuries are a major reason for bleakness and mortality. The quirks in the physiology of liquid and electrolyte taking care of, the vital necessity and the distinctions in the different body extends in children direct that the pediatric wounds administration ought to be brought with an alternate point of view than for adults. Notwithstanding, for the intensivist, challenges regularly exist that muddle quiet help and adjustment. Moreover, burn injuries are mind-boggling and can show exceptional challenges that require deep-rooted recovery. Investigation in burn wound care has yielded progressions that will keep on improving practical recuperation. What's more, pain management all through this period is essential. Managing these wounds requires escalated therapeutic treatment for multi-organ dysfunction, and forceful surgical treatment to forestall sepsis and other inconveniences. The biological therapeutic bilayered skin substitutes with a long shelf life that recapitulates the normal barrier function of the intact human skin and stimulate wound repair and skin regeneration. A definitive objective is to accomplish a perfect skin substitute that gives a successful and without scar wound recuperating. This review article features the headway in pediatric burn wounds with an emphasis on the pathophysiology and treatment of burn wounds.
ARTICLE | doi:10.20944/preprints202301.0431.v1
Subject: Biology, Ecology Keywords: Blood microbiome; skin microbiome; migration; Kerguelen Islands; 16S rRNA.
Online: 24 January 2023 (10:52:08 CET)
Our understanding of how microbiome signatures are modulated in wild fish populations remains poorly known and has, until now, mostly been inferred from studies in commercial and farmed fish populations. Here, we have studied for the first time changes in the skin and blood microbiomes of the Salmo trutta population of the volcanic Kerguelen archipelago located at the northern limit of the Antarctic Ocean. Kerguelen is a natural framework of population expansion and a likely situation under further climate change in distribution areas. Our results showed that S. trutta of Kerguelen has a microbiome signature distinct from those of salmonids of the Northern Hemisphere. Our study also revealed that the skin and blood microbiomes differ between sedentary and migratory S. trutta. While 18 phyla were shared between both groups of trout, independent of the compartment, six phyla were unique to migratory trout. Further analyses showed that microbiome signatures undergo significant site-specific variations that correlate, in some cases, to the peculiarity of specific ecosystems. Our study also revealed the presence of potential pathogens at particular sites and the impact of abiotic factors on the microbiome, most notably due to the volcanic nature of the environment. This study contributes to a better understanding of the factors that modulate the microbiome signatures of migratory and sedentary fish populations. It will also help better monitor climate change's impacts on the colonization process in the sub-Antarctic region.
REVIEW | doi:10.20944/preprints202211.0099.v1
Subject: Medicine & Pharmacology, Dermatology Keywords: Clothing; Health Promotion; Skin Cancer Prevention; Sport; Ultraviolet Radiation
Online: 7 November 2022 (02:06:38 CET)
Australia and New Zealand have the highest incidence of skin cancer. Sport is a fundamental part of Australasian culture, beginning in childhood, often with life-long participation. Participating in outdoor sports can contribute significantly to the lifetime ultraviolet radiation (UVR) dose individuals receive and their risk of developing skin cancer. This systematic scoping review explores the use of sun-protection by outdoor sporting participants in Australasia and considers how sun-protection practices may be better evaluated and improved in the community. A search of electronic databases using the search strategy “sun protection” AND “sport” AND “Australia” yielded 17 studies published in English from January 1992 to August 2021. Study methods included using UV-dosimeters to measure individual UVR-exposure; remote estimates of clothing-adjusted UVR-exposure; direct observation of sun-protection practices; and self-reported sun-exposure and sun-protection. Despite 40-years of ‘Slip Slop Slap’ campaigns in Australia, the use of sun-protection in most outdoor sports is inadequate. The paucity of comparable data limited our analyses, demonstrating a need for standardized, objective evaluation tools. Such tools, if used across a range of sports, should inform the development of workable recommendations that sporting clubs could implement and adopt into policy, thus empowering them to better protect the health of their participants.
REVIEW | doi:10.20944/preprints202203.0107.v1
Subject: Medicine & Pharmacology, Oncology & Oncogenics Keywords: Nanobiotechnology; Biomarkers; Biosensors; Lung cancer; Skin Cancer; Colorectal Cancer
Online: 7 March 2022 (15:03:00 CET)
In the era of nanotechnology, researchers are implementing point to care service to cancer patients to detect malignancy beforehand and to reduce the mortality rate of cancers. Cancer is known to be the most fatal disease among all other diseases and the survivability from cancer is quite impossible if the stage of the cancer is an advanced level. Though the early detection of cancer can increase the chances of survival with a double fold. Biosensor is a part of nanotechnology which is capable to provide point to care service in the field of medicine. With the rising number of cancer occurrences being identified around the world and the increasing number of deaths because of the identification of advanced cancer, biosensors can play a significant part in the early detection of cancer. New molecular methods, including as genomic and proteomic approaches, are increasingly being used to study patient molecular profiles. When such diagnosis method is paired with bioinformatics tools, they generate new data that can be used to discover new disease biomarkers. Finding precise and sensitive indicators that are corelated to a specific disease, as with many other diseases, can be challenging. Furthermore, the concentration of biomarkers in biological fluids varies according to illness states and phases. Peptides, proteins, up or down regulated expression of gene markers, and gene alternation are all examples of molecular markers that are commonly used to diagnose cancer. In this article, we have highlighted six different deadliest cancers such as Ovarian, Breast, Prostrate, Lung, Colorectal and Liver cancer. The article contains distinct types of biomarkers which are normally found in these kinds of cancer and generally used as a potential diagnostic target in the medicine field. The article mainly summarized the application of different types of biosensors devices in the detection of the mostly found biomarkers in the above cancer types.
ARTICLE | doi:10.20944/preprints202106.0722.v1
Subject: Medicine & Pharmacology, Allergology Keywords: Hair cosmetic toxicity; Skin models; Chemical hair straighteners actives
Online: 30 June 2021 (09:38:38 CEST)
Most hair relaxers or straighteners used for Afro-textured hair have a pH above 11. This pH, according to international occupational health and safety guidelines, is corrosive to the skin. Further, relaxers are associated with a 3-6 times increased risk of alopecia. The skin also gets into contact with these hair straightening products during application resulting in skin irritation. Using animals as test subjects to determine these products' potential risk and safety margin is standard practice; however, with the European Union (EU) ban on animal testing, the testing method needs to be replaced by newer in vitro laboratory technologies. This study used previously and newly established in vitro cell-based technologies and human-skin derived cells as laboratory models to evaluate relaxer-induced cytotoxicity. These technologies include endpoint (MTT, CCK-8 and flow cytometry) and real-time assays (real-time cell analysis (RTCA) and extracellular flux analysis). Cellular toxicity was evident following treatment of keratinocytes and fibroblasts with acceptable concentrations of thioglycolic acid (TGA, HSCH2COOH), ammonium bisulphite (NH4HSO3), lithium hydroxide (LiOH) and sodium hydroxide (NaOH) based relaxers. Real-time assays showed significant reductions (P<0.001) in cell index and ATP production following treatment of keratinocytes with as little as one-tenth of the acceptable concentrations. Increased apoptosis (47.9%, 58.0%, 76.7% and 80.3%) also occurred in cells after treatment with TGA, NH4HSO3, NaOH and LiOH, respectively. In conclusion, this study demonstrated that using skin cells in conjunction with advanced cell-based technologies could serve as alternatives to laboratory animals for accessing the toxicity margin of hair relaxers, straighteners and other cosmetics.
COMMUNICATION | doi:10.20944/preprints202011.0298.v1
Subject: Biology, Anatomy & Morphology Keywords: control measures; diagnosis; epidemiological data; Kazakhstan; lumpy skin disease
Online: 10 November 2020 (10:13:28 CET)
Lumpy skin disease (LSD) is an emerging transboundary viral disease of cattle originating from the African continent. Here we describe the first LSD outbreak reported in the Republic of Kazakhstan, in July 2016. Initially, LSD was reported in a cattle farm located 49 km from Kazakh –Russian border in, Atyrau Oblast in West Kazakhstan. Subsequently, the disease spread to neighbouring farms situated within the same district. Following a preliminary investigation, the local State Veterinary Service declared a strict quarantine according to the State Contingency Plan, along with immediate total stamping out and cattle movement restrictions. During the outbreak, the number of affected cattle within an epidemiological unit reached 459 cattle out of registered 3557 susceptible cattle with 12.90% morbidity and 0.96%, mortality. This manuscript presents the epidemiological situation, the diagnosis, the control measures including mass vaccination and the stamping out campaign.s
ARTICLE | doi:10.20944/preprints202003.0192.v1
Subject: Biology, Other Keywords: epidermal keratinocytes; inflammation; nicotinamide; skin; ultraviolet radiation; environmental stressors
Online: 12 March 2020 (03:23:18 CET)
Daily exposure of skin to environmental stressors leads to molecular and morphological changes ascribed as premature aging. These stressors include solar radiation, industrial pollution, fossil fuel and carbon emissions, which cause cellular damage that induces an inflammatory response in skin. Several inflammatory components are known to be involved in triggering the senescence-associated secretory phenotype (SASP) which is known to accelerate aging. It is hypothesized that preventing induction of inflammation by environmental stressors can prevent premature aging. Since it is known that nicotinamide (Nam) has anti-inflammatory properties, we tested whether Nam can inhibit environmental stressor-induced inflammation. Exposure of keratinocytes to UVB, urban dust, diesel exhaust, and cigarette smoke extract stimulated production of the inflammatory mediators PGE2, IL-6, and IL-8 and induced gene expression patterns associated with apoptosis, DNA repair, and cell cycle control. In all cases, Nam treatment significantly inhibited these stress-induced responses. Nam also reduced IL-8 levels stimulated by the combination of topically applied particulate matter (PM2.5) and UV exposure in 3D skin equivalents. Under 5% 02 conditions that more closely mimic physiological 02 levels, Nam had a heightened inhibitory effect on UVB-induced PGE2 levels in keratinocytes. In a UV-challenge study, treatment with Nam reduced skin surface IL-1RA/IL-1 inflammatory biomarkers and erythema that were induced by solar simulated radiation. These findings provide a body of evidence that Nam can mitigate in part the skin’s inflammatory response elicited by exposure to environmental stressors. This supports the potential that Nam can inhibit premature aging and help maintain skin’s functionality and appearance.
ARTICLE | doi:10.20944/preprints201910.0370.v1
Subject: Engineering, Biomedical & Chemical Engineering Keywords: polyurethane; polylactide; tissue engineering; skin scaffold; antibacterial; degradable; medical
Online: 31 October 2019 (09:52:06 CET)
The aim of performed studies was to fabricate an antibacterial and degradable scaffold that may be used in the field of skin regeneration. To reach the degradation criterion the biocompatible polyurethane (PUR), obtained by using amorphous macrodiol α,ω-dihydroxy(ethylene-butylene adipate) macrodiol (PEBA), was used and processed with so-called “fast-degradable” polymer polylactide (PLA) (5 wt% or 10 wt%). To meet the antibacterial requirement obtained hybrid PUR-PLA scaffolds (HPPS) were modified with ciprofloxacin (Cipro) (2 wt% or 5 wt%), the fluoroquinolone antibiotic inhibiting growth of bacteria such as Pseudomonas aeruginosa, Escherichia Coli and Staphylococcus aureus, which are main cause of wound infections. Obtained unmodified and Cipro-modified HPPS were studied towards their chemical composition to detect presence or absence of characteristic functional groups of PUR, PLA and Cipro, and as well to indicate the participation of hydrogen bonds in the HPPS structure in dependence on PLA addition and ciprofloxacin modification. Mechanical properties were studied to determine the possible application of HPPS as a skin tissue scaffold. Scanning electron microscopy (SEM) was used to study morphology of unmodified and Cipro-modified HPPS and to performed elementary analysis by using energy-dispersive x-ray spectroscopy (EDX) of obtained materials. Finally, the microbiological tests were performed to indicate the antibacterial effect of Cipro-modified HPPS on S.aureus growth. Performed studies showed that Cipro-modified HPPS, obtained by using 5 % of PLA, possess suitable mechanical characteristic, morphology, degradation rate and demanded antimicrobial properties to be further developed as a potential scaffolds for skin tissue engineering.
ARTICLE | doi:10.20944/preprints201905.0037.v1
Subject: Life Sciences, Genetics Keywords: Bos taurus; skin; bovine dermcidin; RT-PCR; antimicrobial activity
Online: 6 May 2019 (08:35:59 CEST)
Description of a novel bovine antimicrobial peptide and its antimicrobial spectrum. RNA isolation and RT-PCR were done from various tissues. DCD peptide was synthesized, and antimicrobial activity was analyzed. Bovine dermcidin gene contains five exons intermittent by 4 introns. Bovine DCD-mRNA was 398 bp with ORF 336 bp. Bovine DCD was expressed in skin and blood. Analysis of the amino acid compositions revealed that cysteine was repeated 6 times indicating the presence of 3 disulfide bonds that play role in the peptide stability. Staphylococcus epidermidis, Streptococcus bovis, and Enterococcus faecalis were affected by Bovine DCD peptide. Highest antimicrobial effect was at 50 and 100 µg/ml. The effect on Escherichia coli and Candida albicans was slightly low. In all bacteria, Bovine DCD peptide activity did not affect by varying pH values, but in Staphylococcus aureus, the activity was affected greatly at pH 4.5 and 5.5. The optimum salt concentrations were 100 and 50 mM NaCl with all bacterial strains and E. coli, respectively. In case of C. albicans, the antimicrobial activity of Bovine DCD peptide decreased with increasing the pH value regardless the NaCl concentration. The pH 6.5 of the sweat buffer was the optimum for the Bovine DCD peptide activity.
ARTICLE | doi:10.20944/preprints201901.0003.v1
Subject: Life Sciences, Immunology Keywords: mast cell; dexamethasone; trimeric G protein; Mrgpr; skin; inflammation
Online: 3 January 2019 (08:55:29 CET)
Steroidal anti-inflammatory drugs are widely used for treatment of chronic cutaneous inflammation, such as atopic dermatitis, although it remains unknown how they modulate cutaneous mast cell functions. Murine connective tissue-type mast cells, which were sensitive to mast cell secretagogues, such as compound 48/80 and substance P, were generated by co-culture of bone marrow-derived mast cells with Swiss 3T3 fibroblasts in the presence of stem cell factor. This process was accompanied by up-regulation of a subunit of a trimeric G protein, Gi1, and several Mas-related G protein-coupled receptor (Mrgpr) subtypes. Secretagogue-induced degranulation and up-regulation of these genes were suppressed when they were cultured in the presence of a synthetic glucocorticoid, dexamethasone. The profiles of granule constituents were drastically altered by dexamethasone. Several Mrgpr subtypes were found to be expressed in the cutaneous tissues and their expression levels were decreased in response to topical application of dexamethasone. The numbers of degranulated cutaneous mast cells in response to compound 48/80 were decreased in mice treated with dexamethasone. These results suggest that mast cell-mediated IgE-independent cutaneous inflammation could be suppressed by steroidal anti-inflammatory drugs through down-regulation of Gai1 and several Mrgpr subtypes in mast cells.
REVIEW | doi:10.20944/preprints201809.0215.v1
Subject: Medicine & Pharmacology, Dermatology Keywords: gut microbiota; skin microbiota; inflammation; psoriasis; psoriatic arthritis; dysbiosis
Online: 12 September 2018 (07:49:33 CEST)
Psoriasis is a chronic inflammatory disease characterized by skin lesions. Psoriasis development has been associated both with genetic and environmental factors. Though skin and gut microbiota has been implicated in number of pathologies including atopic dermatitis, inflammatory bowel disease, Crohn’s disease, allergy, obesity, its role has been poorly studied in psoriatic disease, which incorporates both psoriasis and psoriatic arthritis. This literature review summarizes the most recent and major findings on microbiota features in psoriatic disease as well as gives immune system role in the given condition. Despite conflicting findings, psoriasis patients were frequently found to have distinct microbial composition in both skin and guts especially in the major bacterial phyla, Firmicutes, Bacteroidetes, and Akkermansia. Furthermore, bacterial DNA has been found in psoriatic patients both locally and systemically, and altogether suggesting role of bacteria in the chronic disease and future studies in this field.
ARTICLE | doi:10.20944/preprints201703.0133.v1
Subject: Life Sciences, Biophysics Keywords: erythema; swimming; re-application; exposed skin surface; natural sunlight
Online: 17 March 2017 (04:59:23 CET)
Background: The efficacy of sunscreen is evaluated by SPF values, which are quantitatively determined in laboratories on the backs of human subjects according to a standardized procedure. However, SPF cannot be directly translated to sunburn protection under real-life situations because actual efficacy depends on various factors related to human behaviors and environmental conditions. This study clinically evaluated the efficacy of two sunscreen sprays (SPF 30 and SPF 70) under natural sunlight exposure on healthy subjects at the beach. Methods: Twenty subjects were divided into two cells for the two sunscreen sprays (SPF 70 and SPF 30) in a single-center, actual usage test. The primary endpoint of the study was sunburn protection on the dorsal arms and the secondary endpoint was protection on the face and neck. Subjects stayed at the beach for 4 h after application of the sunscreens with normal beach activities. Subjects’ behavior at the beach, the amounts of sunscreen applied and reapplied, and environmental conditions were all recorded. Results: There was no significant sunburn for a majority of the subjects in either cell. However, neither sunscreen completely blocked the sunburn, especially for the face/neck area. We found that the SPF 70 sunscreen was more effective than the SPF 30 sunscreen. Conclusion: Modern sunscreen sprays, applied liberally, are effective in providing sunburn protection for the body in a beach setting.
Subject: Biology, Animal Sciences & Zoology Keywords: feminine hygiene; feminine gel wash; lactic acid; vulvar skin pH; vulvar microbiome; skin microflora; vulvovaginal environment; bacterial 16S rRNA gene; fungal ITS
Online: 9 December 2019 (03:53:52 CET)
Background: While intimate feminine hygiene products are widely used by women as part of daily cleansing routines, little is known about how these products impact the vulvovaginal area and its microbiome stability. A novel gel wash containing lactic acid (pH 4.2) for external daily use was formulated to provide gentle cleansing, freshness, and antimicrobial protection to maintain a healthy balance of the vulvar skin area. This 4-week clinical study assessed tolerance of the gel wash when used on the external genital area and its effects on skin hydration, vulvar skin pH, and the vulvar microbiome. After a 7-day pre-study conditioning period, 36 healthy females in 3 balanced age groups (18-29, 30-44, and 45-55 years) used the gel wash to cleanse their external genital area (mons pubis and vulva) and entire body at least once per day for 28 days. The primary endpoint wasSkin tolerance of the gel wash was assessed by the gynecologist. Effects of the gel wash on vulvar skin microbiota were studied by performing bacterial 16S rRNA and fungal ITS microbial richness and diversity analysis. Results: Based on gynecologic assessment after 28 days of use, the gel wash showed acceptable tolerance, with no signs of increased dryness, redness, edema, itching, stinging, or burning. Use of the gel wash was associated with a significant increase in both short-term (single application) and longer-term (daily use for 28 days) skin moisturization. There was no significant change in vulvar skin pH over time with daily product use, and the gel wash did not significantly affect the natural vulvar microbiome species richness or diversity for bacteria or fungi. Conclusions: Results of the study showed that this new gel wash is a mild, moisturizing cleanser that does not harm and instead maintains the natural pH and microbial diversity of vulvar skin. To our knowledge, this was the first study to assess the effect of an antimicrobial feminine gel wash on the natural pH and vulvar microbiome habitat of the skin using bacterial 16S rRNA and fungal ITS genetic sequencing techniques, thereby providing a better understanding of the bacterial and fungal communities that inhabit the external vulvar area in healthy women.
ARTICLE | doi:10.20944/preprints202211.0179.v1
Subject: Life Sciences, Genetics Keywords: Population genetics; Pigmentary traits; Phototype; Pleiotropy; Skin disease; Eye disease
Online: 10 November 2022 (01:06:40 CET)
Human pigmentation has been largely associated with different disease prevalence among populations, but most of these studies are observational and inconclusive. Known to be genetically determined, pigmentary traits have been largely studied by GWAS, mostly in Caucasian ancestry cohorts from North Europe, identifying robustly, several loci involved in many of the pigmentary traits. Here, we conduct a detailed analysis of 13 pigmentary-related traits in a South European cohort of Caucasian ancestry (n=20,000). We observed fair phototype strongly associated with non-melanoma skin cancer and other dermatoses and confirmed by PRS-approach the shared genetic basis with skin and eye diseases, such as melanoma (OR=0.95), non-melanoma skin cancer (OR=0.93), basal cell carcinoma (OR=0.97) and darker phototype with vitiligo (OR=1.02), and cataracts (OR=1.04). Detailed genetic analyses revealed 37 risk loci associated with 10 out of 13 analyzed traits, and 16 fine-mapped genes significantly associated with at least two pigmentary traits. Some of them widely reported, such as MC1R, HERC2, OCA2, TYR, TYRP1, SLC45A2, and unveiling three new candidates RP11-1084J3.4, C1QTNF3 and C17orf112, not reported in GWAS Catalog. These results highlight the importance of phototype assessment as a genetic proxy of skin functionality when evaluating disease screening in mixed populations.
ARTICLE | doi:10.20944/preprints202209.0215.v1
Subject: Mathematics & Computer Science, Artificial Intelligence & Robotics Keywords: pretrained model; transfer learning; skin cancer; deep learning; ISIC 2020
Online: 15 September 2022 (03:02:06 CEST)
Skin cancer is an uncommon but serious malignancy. Dermoscopic images examination and biopsy are required for cancer detection. Deep learning (DL) is extremely effective in learning characteristics and predicting malignancies. However, DL requires a large number of images to train. Image augmentation and transferring learning were employed to overcome the lack of images issue. In this study we divided images into two categories: benign and malignant. To train and test our models, we used the public ISIC 2020 database. Melanoma is classified as malignant in the ISIC 2020 dataset. Along with categorization, the dataset was studied to demonstrate variation. The performance of three top pretrained models was then benchmarked in terms of training and validation accuracy. Three optimizers were employed to optimize the loss: RMSProp, SGD, and ADAM. Using ResNet, VGG16, and MobileNetV2, we obtained training accuracy of 98.73%, 99.12%, and 99.76%, respectively. Using these three pretrained models, we attained a validation accuracy of 98.39%.
ARTICLE | doi:10.20944/preprints202206.0367.v1
Subject: Medicine & Pharmacology, Other Keywords: rosmarinic acid; anti-inflammatory activity; comet assay; sunscreen; skin biocompatibility
Online: 27 June 2022 (13:22:01 CEST)
The skin acts as a protective barrier, guarding the body against microorganisms, chemicals, and several environmental factors. Accordingly, this all-important organ must be kept healthy to maintain its optimal functionality. One approach to maintain skin health is the application of multifunction bioactive sunscreens containing antioxidant molecule(s). Rosmarinic acid (RA), a phenolic compound, is known for its antioxidant activity. Herein, the safety and efficacy of a multifunction prototype sunscreen were investigated, aiming to probe putative synergies of this polyphenol with two known and widely used UV filters (bemotrizinol and octyl p-methoxycinnamate). Samples protected the DNA fragmentation compared to UV control, by the comet assay, and showed good skin compatibility in subjects. Formulations F1 and F3 were able to increase skin hydration, and, possibly, the RA interfered with this attribute. An increase in transepidermal water loss was observed for formulations F1, F2 and F4, which may be related to vehicle containing or not the RA. No decreases were observed in the inflammatory reaction caused by the ethyl nicotinate with any of the evaluated formulations. As a perspective, we suggest trials with a greater number of subjects or protocol modifications. Altering the vehicle qualitative and quantitative composition is also a pertinent perspective.
ARTICLE | doi:10.20944/preprints202202.0131.v1
Subject: Medicine & Pharmacology, Dermatology Keywords: AD; allergy; skin; DNCB; Panax ginseng; red ginseng marc; fermentation
Online: 9 February 2022 (10:26:55 CET)
Atopic dermatitis (AD) is a chronic and allergic skin disease, however, there is no cure for the disease. Many studies have shown anti-AD potentials of red ginseng, while red ginseng marc (RGM) remained after the ginseng extraction is discarded as industrial waste. However, it is recently reported that RGM, particularly fermented RGM (fRGM), still contains the bioactive properties. Thus, anti-allergic effects of fRGM were examined in 2,4-dinitrochlorobenzene-induced AD-like mice model. The model was topically treated with distilled water (control), dexamethasone, or fRGM for six weeks. The treatments of fRGM alleviated the skin lesions and reduced serum IgE levels, compared with the control. The fRGM also reduced skin levels of lipid peroxidation and superoxide anion, however, increased glutathione contents, with down-regulated gene expressions for inflammatory mediators. The histopathological analyses demonstrated that fRGM suppressed the epidermal thickening, collagen deposition, and inflammatory cell and mast cell infiltration, which involved the anti-inflammatory, anti-oxidant, and anti-apoptotic effects. Further, fRGM suppressed hypertrophic changes and inflammatory responses in the spleen and lymph node. The beneficial effects were observed in the dexamethasone and fRGM groups, however, the antioxidant effects were evident only in the fRGM treatments. These provide useful information for developing fRGM as therapeutic sources for AD.
ARTICLE | doi:10.20944/preprints202104.0561.v1
Subject: Medicine & Pharmacology, Allergology Keywords: Pseudomonas; antibiotic resistance; dog; infection; skin, otitis externa, perianal abscess.
Online: 21 April 2021 (09:02:48 CEST)
Treating infections caused by Pseudomonas aeruginosa is increasingly difficult due to high antimicrobial resistance, materialized through the presence of multiple resistance strains, as well as due to rapid development of resistance throughout treatment. The present survey was conducted to investigate the antibiotic susceptibility profile of Pseudomonas aeruginosa pathogens, in two University Veterinary hospitals from different geographical regions of Romania (i.e., south-west - Timisoara county and north-east – Iasi county) involved in canine superficial infections. A total of 142 swab specimens were collected from dogs with superficial infections (superficial skin infections, otitis externa, perianal abscess), with the aim of assessing the presence of Pseudomonas aeruginosa, based on phenotypic and molecular characterization. Fifty-eight samples (40.84%; 58/142) were positive for Pseudomonas aeruginosa (according to their confirmed morphological and molecular features). Susceptibility to usual antibiotics used in the treatment of canine skin conditions was tested for all Pseudomonas strains that were isolated from canine superficial infections, using the Kirby Bauer disc diffusion method. Drug resistance was observed in the case of all tested antibiotics. The susceptibility rate of P. aeruginosa strains that were tested in this study was in the following order: ampicillin sulbactam (55.17%; 32/58), followed by ceftazidime (53.44%; 31/58), aztreonam (51.72%; 30/58), amikacin (44.82%; 26/58), azithromycin (41.37%; 24/58), gentamycin (37.93%; 22/58), cefepime (36.20%; 21/58) meropenem (25.86%; 13/58), piperacillin-tazobactam (25.86%; 13/58) imipenem (22.41%; 13/158), ciprofloxacin (17.24%; 10/58) tobramycin (8.62; 5/58), and polymyxin B (1.72; 1/58) respectively. The results highlight the importance of antibiotic susceptibility testing in Pseudomonas aeruginosa isolates from dogs with superficial infections, in order to use an adequate treatment plan for the management of the skin condition, and other pathology (otitis externa and perianal abscesses).
ARTICLE | doi:10.20944/preprints202102.0414.v1
Subject: Physical Sciences, Optics Keywords: Skin hydration; Optical sensor; near infrared spectroscopy; Monte Carlo Simulation
Online: 18 February 2021 (12:07:29 CET)
Dermal water content is an important biophysical parameter in preserving skin integrity and preventing skin damage. Traditional electrical-based and open-chamber evaporimeters have several well-known limitations. In particular, such devices are costly, sizeable, and only provide arbitrary outputs. They also do not permit continuous and non-invasive monitoring of dermal water content, which can be beneficial for various consumer, clinical and cosmetic purposes. We report here on the design and development of a digital multi-wavelength optical sensor that performs continuous and non-invasive measurement of dermal water content. In-silico investigation on porcine skin was carried out using the Monte Carlo modelling strategy to evaluate the feasibility and characterise the sensor. Subsequently, an in-vitro experiment was carried out to evaluate the performance of the sensor and benchmark its accuracy against a high-end, broad band spectrophotometer. Reference measurements were made against gravimetric analysis. The results demonstrate that the developed sensor can deliver accurate, continuous, and non-invasive measurement of skin hydration through measurement of dermal water content. Remarkably, the novel design of the sensor exceeded the performance of the high-end spectrophotometer due to the important denoising effects of temporal averaging. The authors believe, in addition to wellbeing and skin health monitoring, the designed sensor can particularly facilitate disease management in patients presenting diabetes mellitus, hypothyroidism, malnutrition, and atopic dermatitis.
ARTICLE | doi:10.20944/preprints202012.0123.v1
Subject: Life Sciences, Biochemistry Keywords: Skin cancer; Photoprotection habits; Photoexposure; University students; Teachers health sciences
Online: 7 December 2020 (07:04:11 CET)
Background: Excessive sun exposure, together with insufficient protection, is the main risk factor for the onset of Melanoma and Non Melanoma skin cancer, namely the most common cancer in fair-skinned populations across the world, and of several other skin and eye adverse health effects. Epidemiological data show the existence of scant awareness of this risk, and of high rates of sunburn among young people. The main aim of the present study is to examine sun exposure habits and protection behaviour in university students. Methods: We performed a cross-sectional questionnaire-based study to investigate sun exposure and protection practices in a group of education sciences students at a university in southern Spain. This survey provided data for a descriptive and comparative analysis, by groups and gender, of photoprotection and skin self-examination practices. The reliability and validity of the questionnaire have been analysed. Results: The questionnaire was completed by 315 students. Most of them (74.6%) have suffered at least one sunburn in the last year. The use of sunscreen or protective clothing is not frequent, and 89.5% of students do not self-examine their skin. The metric properties of the questionnaire showed high values of reliability and validity. Conclusions: The awareness of solar exposure risk in Spanish university students of Education Sciences is low, self-protection is scant, the potential exposure to dangerous levels of UV radiation is high and most students have suffered one or more sunburns in the last year. Intervention strategies should be introduced in these students to highlight the risks involved and the need of more adequate sun protection practices. Information campaigns should be conducted to address the problem so that, when these students become teachers, they have an adequate knowledge of the risk and of the benefits of a higher attention to this problem, and can translate these competences in health education.
ARTICLE | doi:10.20944/preprints202010.0572.v1
Subject: Life Sciences, Biochemistry Keywords: aging; collagen; extracellular matrix; fibroblast; skin; tenascin C; TGF-β
Online: 28 October 2020 (08:49:54 CET)
Tenascin C (TNC) is an element of the extracellular matrix (ECM) of various tissues, including the skin, and is involved in modulating ECM integrity and cell physiology. Although skin aging is apparently associated with changes in the ECM, little is known about the role of TNC in skin aging. Here we found that Tnc mRNA level was significantly reduced in the skin tissues of aged mice compared with young mice, consistent with reduced TNC protein expression in aged human skin. TNC-large (TNC-L; 330-kDa) and -small (TNC-S; 240-kDa) polypeptides were observed in conditional media from primary dermal fibroblasts. Both recombinant TNC polypeptides, corresponding to TNC-L and TNC-S, increased the expression of type I collagen and reduced the expression of matrix metalloproteinase-1 in fibroblasts. Treatment of fibroblasts with a recombinant TNC polypeptide, corresponding to TNC-L, induced phosphorylation of SMAD2 and SMAD3. TNC increased the level of TGF-β1 mRNA and upregulated the expression of type I collagen by activating the TGF-β signaling pathway. In addition, TNC also promoted the expression of type I collagen in fibroblasts embedded in a three-dimensional collagen matrix. Our findings suggest that TNC contributes to the integrity of ECM in young skin and to prevention of skin aging.
ARTICLE | doi:10.20944/preprints202009.0627.v1
Subject: Engineering, Automotive Engineering Keywords: multi-strand cable lines; ampacity; skin and proximity effects; symmetry
Online: 26 September 2020 (12:17:53 CEST)
Skin and proximity effects have a considerable impact on current distribution in multi-strand cable lines. Under unfavorable heat exchange conditions some strands may be subject to excessive overheating, what may lead to serious malfunctions or even fires of the installation. The paper proposes a new criterion for a quick choice of spatial configurations, for which the effect might be minimized. A comprehensive analysis of literature cases is provided, including the recommendations of the U.S. National Code and the Canadian standard.
ARTICLE | doi:10.20944/preprints201806.0331.v1
Subject: Engineering, Electrical & Electronic Engineering Keywords: capacitive imaging; skin hydration; solvent penetration; water content; solvent content
Online: 21 June 2018 (05:21:42 CEST)
Capacitive contact imaging has shown potential in measuring skin properties including hydration, micro relief analysis, as well as solvent penetration measurements. Through calibration we can also measure the absolute permittivity of the skin, and from absolute permittivity we then work out the absolute solvent content in skin. In this paper, we present our latest study of capacitive contact imaging for skin characterizations and vivo skin solvent penetration. We will show how to use capacitive occlusion measurements to characterize skin damages, and how to calculate the absolute water content and solvent content in skin.
ARTICLE | doi:10.20944/preprints202212.0364.v1
Subject: Medicine & Pharmacology, Dermatology Keywords: Phaseolus angularis seed extract (PASE); anti-aging; health skin, cosmetic products
Online: 20 December 2022 (09:03:36 CET)
Skin photoaging is caused by prolonged exposure to ultraviolet (UV) radiation from sunlight. UV-exposed skin appears rough, thick, dry, loose, and shows deep wrinkles, and thickening. Our previous research showed that a Phaseolus angularis seed extract (PASE) effectively inhibits photoaging through UVB protection in HaCaT cells. However, its efficacy has not been evaluated in clinical trials so far. In this single-centered, randomized, double-blind study, we investigated the anti-aging effect of PASE in eye wrinkle areas. To these 21 healthy adult women aged 30 to 65, a PASE cream was applied to the right eye wrinkle area and a placebo to the left eye wrinkle area twice a day (morning and evening) for 12 weeks. The change in thick, deep crease wrinkles around the eyes was confirmed by visual evaluation, skin measurements, and a questionnaire. As a result, the R1 (surface roughness), R2 (maximum roughness), R3 (average roughness), R4 (smoothness depth), and R5 (arithmetic mean roughness) values in the group using the PASE cream all decreased. Particularly, R1, R4, and R5 significantly decreased by 18.1%, 18.6%, and 25.0%. In addition, no participants reported side effects. Our study showed that PASE led to clinically significant levels of wrinkle improvement. In conclusion, as PASE is a natural food, safe, and with few side effects, it can be a good resource for natural anti-wrinkle cosmetics in the future.
CASE REPORT | doi:10.20944/preprints202212.0172.v1
Subject: Medicine & Pharmacology, Other Keywords: muscle-skeletal traumas (MST); injury; fracture stabilization; local flaps; skin-grafting
Online: 9 December 2022 (07:13:55 CET)
The combined muscle-skeletal traumas (MST) are very frequent over the last few years. The emergency care try to save the life of the patient and to receive resuscitation treatment. The role of Trauma surgeon is to choose the right moment for surgery. Aim: To present the management of patient with combined height injury, fracture stabilization, partial foot amputation, local flaps, skin grafting and HIFU – thermotherapy as scar treatment. Materials and methods: 40 years old mail patient, injured after a fall from 8 meters in an elevator shaft. After resuscitation treatment to control the shock the Imaging results are: burst fracture of L3 with spinal canal stenosis, fracture of the sacral bone Denis I, fracture of the right humerus in the proximal third, Monteggia fracture of the left arm, fracture of the proximal third of the right tibia as well as comminuted fractures of both calves and of both heel bones. Results: After a few operations his final result was well healed bone fractures and a good quality soft tissue coverage allowing the patient a satisfactory quality of life. Conclusions: Combined traumas of the muscle- skeletal system are severe, serious and difficult to manage. The good outcome in their treatment requires a team approach between the different medical specialists.
REVIEW | doi:10.20944/preprints202201.0117.v1
Subject: Life Sciences, Cell & Developmental Biology Keywords: G protein-coupled receptor; mouse models; skin cancer; UVR; drug; network
Online: 10 January 2022 (13:41:08 CET)
G protein-coupled receptors (GPCRs) serve prominent roles in melanocyte lineage physiology, with an impact at all stages of development, as well as on mature melanocyte functions. GPCR ligands are present in the skin and regulate melanocyte homeostasis, including pigmentation. The role of GPCRs in the regulation of pigmentation and, consequently, protection against external aggression, such as ultraviolet radiation, has long been established. However, evidence of new functions of GPCRs directly in melanomagenesis has been highlighted in recent years. GPCRs are coupled, through their intracellular domains, to heterotrimeric G proteins, which induce cellular signaling through various pathways. Such signaling modulates essential cellular processes of melanomagenesis, such as proliferation and migration. GPCR-associated signaling in melanoma can be activated by the binding of paracrine factors to their receptors or directly by activating mutations. In this review, we present melanoma-associated alterations of GPCRs and their downstream signaling and discuss the various preclinical models used to evaluate new therapeutic approaches against GPCR activity in melanoma. Recent striking advances in our understanding of the structure, function, and regulation of GPCRs will undoubtedly broaden treatment options in melanoma in the future.
ARTICLE | doi:10.20944/preprints202109.0209.v1
Subject: Keywords: Skin Disease Detection; Machine Learning (ML); Deep Learning(DL); Artificial Intelligence
Online: 13 September 2021 (11:54:04 CEST)
Skin disease is a very common disease for humans. In the medical industry detecting skin disease and recognizing its type is a very challenging task. Due to the complexity of human skin texture and the visual closeness effect of the diseases, sometimes it is really difficult to detect the exact type. Therefore, it is necessary to detect and recognize the skin disease at its very first observation. In today's era, artificial intelligence (AI) is rapidly growing in medical fields. Different machine learning (ML) and deep learning(DL) algorithms are used for diagnostic purposes. These methods drastically improve the diagnosis process and also speed up the process. In this paper, a brief comparison between the machine learning process and the deep learning process was discussed. In both processes, three different and popular algorithms are used. For the machine Learning process Bagged Tree Ensemble, K-Nearest Neighbor (KNN), and Support Vector Machine(SVM) algorithms were used. For the deep learning process three pre-trained deep neural network models
ARTICLE | doi:10.20944/preprints202102.0378.v1
Subject: Materials Science, Biomaterials Keywords: salt-cured cod skin; Gadus morhua; collagen; fishery by-products; biomaterials
Online: 17 February 2021 (10:39:19 CET)
Collagen is the most abundant protein in the animal kingdom. Industrial collagen is mainly bovine and porcine origin. However, due to religious beliefs, allergic issues, and infectious diseases, alternative sources of collagen as marine are gaining increasing interest. In this work, the acid-soluble collagen (ASC) were extracted from salt-cured Atlantic cod (Gadus morhua) skin and characterized. The extraction yield was about 2.0%, equivalent to the extraction yield reported for other fish skins. The electrophoretic pattern showed the typical type I structure (α, β and γ chains). UV-VIS and FTIR absorbance spectra suggested a very pure ASC with an intact triple helical structure. The integrity and the adequate porosity required for different applications were then confirmed by electron micrograph. Our findings allow us to say that, for the first time, we extracted acid-soluble type I collagen from salt-cured Atlantic cod skin, with characteristics suitable for application in various fields, such as biomedical.
ARTICLE | doi:10.20944/preprints202012.0067.v1
Subject: Medicine & Pharmacology, Allergology Keywords: ABC transporters; SLC transporters; in vitro; skin; inflammation; cytokines; UVA; UVB
Online: 2 December 2020 (14:48:32 CET)
The majority of skin cancers are caused by over exposure to ultraviolet (UV) radiation. The effects of UV radiation on the expression of drug transporters expressed in human skin has never been studied. In this the effects of UVA and UVB irradiation on the expression of ATP-binding cassette (ABC) transporters and Solute carrier (SLC) transporters was evaluated in normal human epidermal keratinocytes (NHEK) and normal human dermal fibroblasts (NHDF) in primary culture. First experiments were intended to validate the inflammatory reaction in response to stimulation by lipopolysaccharide (LPS) in NHEK, NHDF and 3D-reconstructed human epidermis (3D-RHE) model. LPS treatment has shown to increase the expression of IL-8 and TNF-alpha in all three in vitro models. Expression of the most expressed ABC and SLC transporters was then measured in NHEK and NHDF after UVA (30 J/m²) and UVB (40 mJ/m²) irradiation. The most striking result was a significant 29-fold increase of the expression of SLCO4A1 in normal human dermal fibroblasts. In summary, this study shows for the first time a significant regulation of the expression of SLCO4A1 in human dermal fibroblasts induced by UVA irradiation. This finding is of particular interest as most of skin cancers are caused by over exposure to ultraviolet radiation and need to be considered in pharmacokinetic evaluation of topical drugs.
Subject: Life Sciences, Biochemistry Keywords: Ultraviolet; superoxide; singlet Oxygen; cell blebbing; skin aging; peroxidative cascade; antioxidants
Online: 21 October 2020 (10:32:55 CEST)
The interaction of ultraviolet radiation with biological matter results in direct damage such as pyrimidine dimers in DNA. It also results in indirect damage provoked by the production of Reactive Oxygen Species (ROS) catalyzed by photo-sensitizers. Photosensitizers can be endogenous (e.g. Tryptophan) or exogenous (e.g. TiO2 and other photo-stable UVA sunscreens). Direct damage triggers an inflammatory response and the oxidative and proteolytic bursts that characterize its onset. The inflammatory reaction multiplies the effects of one single photon. Indirect damage, such as the peroxidative cascade in membrane lipids, can extend to thousands of molecular modifications per absorbed photon. Sunscreens should therefore be formulated in the presence of appropriate anti-oxidants. Superoxide and Singlet Oxygen are the main ROS that need to be tackled: this review describes some of the molecular, biochemical, cellular and clinical consequences of exposure to UV radiation as well as some results associated with scavengers and quenchers of Superoxide and Singlet Oxygen, as well as with inhibitors of singlet Oxygen production.
ARTICLE | doi:10.20944/preprints201911.0171.v1
Subject: Medicine & Pharmacology, Dermatology Keywords: ulmus parvifolia; wound healing; matrix metalloproteinase; transforming growth factor; skin rejuvernation
Online: 15 November 2019 (04:05:45 CET)
Ulmus species have been widely used in Korean folk medicine because of their anti-inflammatory and antimicrobial properties. We intended to investigate the wound healing effect of the powder of Ulmus parvifolia (UP) root bark in a mouse wound healing model. We also determined the mechanisms of effects of Ulmus parvifolia (UP) in skin and skin wound healing effect using keratinocyte model. in vivo experiments showed that the wound lesions in the mice decreased by U. parvifolia with 200 mesh size of root bark powder and significantly reduced by treatment with UP, compared with those treated with U. macrocarpa (UM). Results from in vitro experiments also revealed that UP extract promoted the migration of human skin keratinocytes. UP powder treatment upregulated the expression of the matrix metalloproteinase-2 and -9 protein and significantly increased transforming growth factor (TGF)-β levels. We confirmed that topical administration of the bark powder of exerted a significant effect on skin wound healing by upregulating the expression of MMP and transforming growth factor-β. TGF-β In, Our study suggests that U. parvifolia may be a potential candidate for skin wound healing including epidermal skin rejuvernation.
ARTICLE | doi:10.20944/preprints201810.0756.v1
Subject: Mathematics & Computer Science, Artificial Intelligence & Robotics Keywords: Dermoscopic Image, Skin Lesion, Melanoma, Simulation, Generative Adversarial Networks, Deep Learning
Online: 1 November 2018 (17:54:12 CET)
Automated skin lesion analysis is one of the trending fields that has gained attention among the dermatologists and healthcare practitioners. Skin lesion restoration is an essential preprocessing step for lesion enhancements for accurate automated analysis and diagnosis. Digital hair removal is a non-invasive method for image enhancement by solving the hair-occlusion artefact in previously captured images. Several hair removal methods were proposed for skin delineation and removal. However, manual annotation is one of the main challenges that hinder the validation of these proposed methods on a large number of images or using benchmarking datasets for comparison purposes. In the presented work, we propose a realistic hair simulator based on context-aware image synthesis using image-to-image translation techniques via conditional adversarial generative networks for generation of different hair occlusions in skin images, along with the ground-truth mask for hair location. Besides, we explored using three loss functions including L1-norm, L2-norm and structural similarity index (SSIM) to maximise the synthesis quality. For quantitatively evaluate the realism of image synthesis, the t-SNE feature mapping and Bland-Altman test are employed as objective metrics. Experimental results show the superior performance of our proposed method compared to previous methods for hair synthesis with plausible colours and preserving the integrity of the lesion texture.
ARTICLE | doi:10.20944/preprints201806.0174.v1
Subject: Materials Science, Metallurgy Keywords: operational aircraft; skin corrosion; fatigue crack growth; stress corrosion cracking; buckling
Online: 12 June 2018 (08:36:13 CEST)
This paper studies the combined effect of corrosion and fatigue on the growth of cracks in aircraft and on the effect of skin corrosion and stress corrosion cracking on the load bearing capacity of rib stiffened aircraft wings. In this context it is shown that the growth of cracks from surface pitting, and also from intergranular cracking at a fastener hole, can be accurately computed using the Hartman-Schijve variant of the NASGRO crack growth equation. The examples studied support the lead crack approach, that has been independently developed by the USAF and the Australian Defence Science Technology Group, in which the growth of lead cracks is often exponential. In the case of skin corrosion it is shown that to be consistent with the US Joint Service Structural Guidelines (JSSG2006) assessment of its effect on the load bearing capacity of the wing should involve an assessment of whether at 115% DLL the remaining material exceeds the yield stress of the material.
ARTICLE | doi:10.20944/preprints202211.0463.v1
Subject: Behavioral Sciences, Behavioral Neuroscience Keywords: Neuroscience; Education; Learning; Brain activity; Heart activity; Skin Conductance; Neuroimaging; Wearable devices
Online: 25 November 2022 (02:40:05 CET)
Nowadays, fostered by technological progress and contextual circumstances such as economic crisis and pandemic restrictions, remote education is living a growing deployment. However, this growth generated widespread doubts about the actual effectiveness of remote/online compared to face-to-face education. The present study aimed at comparing face-to-face and remote education through a multimodal neurophysiological approach. It involved forty students at a driving school, during a real classroom, experiencing both the modalities. Wearable devices to measure brain, ocular, heart and sweating activities were employed in order to analyse the students’ neurophysiological signals to obtain insights about their cognitive dimension. In particular, four parameters were considered, the Eye Blink Rate, the Heart Rate and its Variability and the Skin Conductance Level. Also, the students filled a questionnaire at the end to obtain an explicit measure of their learning performance. Data analysis showed a higher cognitive activity, in terms of attention and mental engagement, in presence with respect to remote modality. On the other hand, students by remote felt more stressed, in particular during the first part of the lesson. Analysis of questionnaires demonstrated worst performance by remote, thus suggesting a common “disengaging” behaviour when attending remote courses, thus undermining their effectiveness. In conclusion, neuroscientific tools could help to obtain insights about mental concerns, often «blind», such as attentional decreasing and stress increasing, as well as their dynamics during the lesson itself, so allowing to define proper countermeasures to emerging issues when introducing new practices into daily life.
ARTICLE | doi:10.20944/preprints202201.0289.v1
Subject: Life Sciences, Biochemistry Keywords: food allergy; allergens; allergenicity reduction; skin prick test; proteomic analysis; physical treatments
Online: 20 January 2022 (08:34:30 CET)
Hazelnut is a widespread nut species, especially in Europe, that can be consumed raw or roasted, due to its pleasant taste and nutritional properties. Despite the renowned beneficial properties, hazelnuts contain several proteins capable of inducing food allergy in sensitized individuals such as Cor a 2 (profilin), Cor a 8 (lipid transfer protein), Cor a 9 (11S seed storage globulin, legumin-like) and Cor a 11 (7S seed storage globulin, vicilin-like). In the present paper we investigated the effectiveness of autoclave based treatments in decreasing the allergic potential of hazelnut as also assessed by submitting the treated material to in vivo skin prick test and to in vitro immunoblot analysis with sera of allergic individuals exposed to the treated food material. This preliminary analysis shows that autoclave treatment, preceded by hydration and/or followed by drying, seems to be a promising approach and appears to be effective in reducing the allergenicity of hazelnut in most patients, probably due to the denaturation of most major and minor allergenic proteins. This work will open to the opportunity to produce, in perspective, hypoallergenic hazelnut derivatives tolerated by the allergic subjects.
ARTICLE | doi:10.20944/preprints202201.0258.v1
Subject: Mathematics & Computer Science, Artificial Intelligence & Robotics Keywords: Skin cancer; Deep learning; Hybrid feature extractor; Local binary pattern; Feature extraction
Online: 18 January 2022 (12:43:50 CET)
Skin cancer is an exquisite disease globally nowadays. Because of the poor contrast and apparent resemblance between skin and lesions, automatic identification of skin cancer is complicated. The rate of human death can be massively reduced if melanoma skin cancer can be detected quickly using dermoscopy images. In this research, an anisotropic diffusion filtering method is used on dermoscopy images to remove multiplicative speckle noise and the fast-bounding box (FBB) method is applied to segment the skin cancer region. Furthermore, the paper consists of two feature extractor parts. One of the two features extractor parts is the hybrid feature extractor (HFE) part and another is the convolutional neural network VGG19 based CNN feature extractor part. The HFE portion combines three feature extraction approaches into a single fused feature vector: Histogram-Oriented Gradient (HOG), Local Binary Pattern (LBP), and Speed Up Robust Feature (SURF). The CNN method also is used to extract additional features from test and training datasets. This two-feature vector is fused to design the classification model. This classifier performs the classification of dermoscopy images whether it is melanoma or non-melanoma skin cancer. The proposed methodology is performed on two ordinary datasets and achieved the accuracy 99.85%, sensitivity 91.65%, and specificity 95.70%, which makes it more successful than previous machine learning algorithms.
ARTICLE | doi:10.20944/preprints202112.0516.v1
Subject: Medicine & Pharmacology, Pediatrics Keywords: health attitudes; health knowledge; skin cancer; sun protection; ultraviolet radiation; UV index
Online: 31 December 2021 (11:56:09 CET)
More than twenty-five years ago the Global Solar UV index (UVI) has been introduced as a simple means of visualizing the intensity of ultraviolet radiation and to alert people to the need for sun protection. In our survey among directors of 436 kindergartens in southern Germany we investigated the level of awareness and knowledge about the UVI as well as the practical consequences for sun protection in kindergartens. Less than half of the directors (n=208, 47.7%) had ever heard of the UVI, and only a small minority of them (n=34, 8.7%) used the daily UVI information to adapt sun protective measures in their kindergartens. Detailed knowledge about the UVI was a rarity among the respondents. The proportion of respondents with self-perceived detailed UVI knowledge was five times higher than actual knowledge assessed by an in-depth structured interview using open-ended questions about the UVI (14.2% vs. 2.8%). No clear relationship of UVI awareness, knowledge, and use to directors' age and gender was found. The UVI-related variables also showed no association with directors' knowledge of risk factors for skin cancer and their attitudes towards tanned skin. Overall, the results paint a sobering picture regarding the penetration of the UVI into sun protection policies of German kindergartens. Future public health campaigns should target increasing awareness and understanding of the UVI as well as its importance for sun protection of children.
ARTICLE | doi:10.20944/preprints202112.0178.v1
Subject: Materials Science, Biomaterials Keywords: hydrogel dressing; full-thickness skin regeneration; 3D cell culture; VE-cadherin; FGF
Online: 10 December 2021 (13:10:47 CET)
The process of full-thickness skin regeneration is complex and has many parameters involved, which makes it difficult to use a single dressing to meet the various requirements of the complete regeneration at the same time. Therefore, developing hydrogel dressings with multifunction, including tunable rheological properties and aperture, hemostatic, antibacterial and super cytocompatibility, is a desirable candidate in wound healing. In this study, a series of complex hydrogels were developed via the hydrogen bond and covalent bond between chitosan (CS) and alginate (SA). These hydrogels exhibited suitable pore size and tunable rheological properties for cell adhesion. Chitosan endowed hemostatic, antibacterial properties and great cytocompatibility and thus solved two primary problems in the early stage of the wound healing process. Moreover, the sustained cytocompatibility of the hydrogels was further investigated after adding FGF and VE-cadherin via the co-culture of L929 and EC for 12 days. The confocal 3D fluorescent images showed that the cells were spherical and tended to form multicellular spheroids, which distributed in about 40-60μm thick hydrogels. Furthermore, the hydrogel dressings significantly accelerate defected skin turn to normal skin with proper epithelial thickness and new blood vessels and hair follicles through the histological analysis of in vivo wound healing. The findings mentioned above demonstrated that the CS/SA hydrogels with growth factors have tremendous potential as multifunctional hydrogel dressings for full-thickness skin regeneration incorporated with hemostatic, antibacterial, sustained cytocompatibility for 3D cell culture and normal skin repairing.
ARTICLE | doi:10.20944/preprints202102.0614.v1
Subject: Life Sciences, Biochemistry Keywords: Mesenchymal stem cells; Camelus dromedaries; skeletal muscle; dermal skin; adipose tissue; differentiation
Online: 1 March 2021 (17:40:43 CET)
Mesenchymal stem cells (MSCs) showed in vitro mesoderm-lineage differentiation and self-renew capacity. However, no comparative study was reported on the biological characteristics of stem cells derived from skeletal muscle (SM-MSCs), dermal skin (DS-MSCs), and adipose tissues (A-MSCs) from a single donor in camels. The present study aimed to evaluate the influence of MSCs source on stem cell characteristics. We evaluated proliferation capacity and mesoderm-lineage differentiation potential from SM-MSCs, DS-MSCs, and A-MSCs. They showed spindle-like morphology after homogenization. The proliferation ability was no significant difference in all groups. Furthermore, the portion of the cell cycle and expression of pluripotent markers (Oct4, Sox2, and Nanog) were similar in all cell lines at passage 3. The differentiation capacity of A-MSCs into adipocytes was significantly higher than that of SM-MSCs and DS-MSCs. However, the osteoblast differentiation capacity of A-MSCs was significantly lower than that of SM-MSCs and DS-MSCs. Additionally, after osteoblast differentiation, the ALP activity and calcium content was significantly decreased in A-MSCs as compared to SM-MSCs and DS-MSCs. To the best of our knowledge, we primally established MSCs from the single camel and demonstrated their comparative characteristics including expression of pluripotent factors and proliferation, and in vitro differentiation capacity into adipocytes and osteoblasts.
BRIEF REPORT | doi:10.20944/preprints202004.0150.v1
Subject: Medicine & Pharmacology, Dermatology Keywords: actinic keratosis; cutaneous squamous cell carcinoma; cytoplams; skin cancer; heat shock protein
Online: 9 April 2020 (12:21:19 CEST)
Background: Cutaneous squamous skin cell carcinoma (SCC) is the second most frequent type of non- melanoma skin cancer and the second cause of death by skin cancer in caucasian population. However, at present it is difficult to predict patients with worst SCC prognosis. Objective: To identify proteins whose expression level could predict SCC infiltration in SCC arising from actinic keratosis (AC). Methods: A total of 20 biopsies of 20 different patients were studied, 10 were from SCC-AK samples and 10 from normal skin. Early infiltrated SCC-AK were selected on histological examination and to determine the expression of proteins fresh skin samples were processed by 2DE-electrophoresis Results: The expression levels of three proteins namely alpha-hemoglobin, heat shock protein (Hsp)-27 and 70 were significantly increased in SCC-AK samples with respect to normal control skin. However, only the expression level of Hsp70 protein positively correlated with the level of SCC-AK dermis infiltration. Immnunohistological examination suggested that the increased expression of Hsp70 proteins seems to mainly occur in the keratinocytes cytoplasm. The increased cytoplasmic Hsp70 expression in SCC-AK was confirmed by Western-blot experiments. Conclusion: Cytoplasmic expression of Hsp70 could be potential biomarker of early infiltration of SCC arising from an AK. Keywords: actinic keratosis, cutaneous squamous cell carcinoma; cytoplasm, skin cancer; heat shock protein.
ARTICLE | doi:10.20944/preprints202002.0231.v1
Subject: Mathematics & Computer Science, Artificial Intelligence & Robotics Keywords: Convolutional Neural Networks; ensemble of classifiers; activation functions; image classification; skin detection
Online: 17 February 2020 (01:50:08 CET)
In recent years, the field of deep learning achieved considerable success in pattern recognition, image segmentation and may other classification fields. There are a lot of studies and practical applications of deep learning on images, video or text classification. In this study, we suggest a method for changing the architecture of the most performing CNN models with the aim of designing new models to be used as stand-alone networks or as a component of an ensemble. We propose to replace each activation layer of a CNN (usually a ReLu layer) by a different activation function stochastically drawn from a set of activation functions: in this way the resulting CNN has a different set of activation function layers.
REVIEW | doi:10.20944/preprints201912.0393.v1
Subject: Medicine & Pharmacology, Oncology & Oncogenics Keywords: cutaneous lymphoma in elderly; skin tumors; T-cell lymphomas; sport activity training
Online: 30 December 2019 (05:43:39 CET)
PcALCL mainly concerns elderly patients. It is a large CD30+ T-cell neoplasm composed of large cells with anaplastic, pleomorphic or immunoblastic morphology, with exclusively cutaneous onset and localization. The clinical course of pcALCL is predominantly indolent. Most elderly patients with lymphoma tend to have a sedentary lifestyle, which has a negative effect on their quality of life (QoL) and on their survival. Several studies indicate that exercise has a positive impact on QoL because it reduces peak oxygen consumption, improves physical capacity, increases self-esteem, reduces accumulated stress and promotes relaxation. Therefore, particularly in indolent lymphomas, it is necessary to indicate a program of physical activity to be practiced systematically. The complete surgical excision and local radiotherapy are the first line gold standard in pcALCL with solitary lesion.
ARTICLE | doi:10.20944/preprints201909.0142.v1
Subject: Keywords: uremic pruritus; ion channels; cell signaling; Cav3.2 calcium channel; RT-PCR; skin
Online: 14 September 2019 (19:00:34 CEST)
Background: We investigated ion channels at the skin, including peripheral nerve endings, which serve as output machines and molecular integrators of many pruritic inputs mainly received by multiple G protein-coupled receptors (GPCRs). Methods: Based on the level of chronic kidney disease–associated pruritus (CKD-aP), subjects were divided into two groups: non-CKD-aP (no or slight pruritus; n=12) and CKD-aP (mild, moderate, or severe pruritus; n=11). Skin samples were obtained from the forearm or elbow during operations on arteriovenous fistulas. We measured ion channels expressed at the skin, including peripheral nerve endings by RT-PCR: Nav1.8, Kv1.4, Cav2.2, Cav3.2, BKCa, Anoctamin1, TRPV1, TRPA1, and ASIC. Results: Expression of Cav3.2, BKCa, and anoctamin1 was significantly elevated in patients with CKD-aP. On the other hand, expression of TRPV1 was significantly reduced in these patients. We observed no significant difference in the levels of Cav2.2 or ASIC between subjects with and without CKD-aP. TRPA1, Nav1.8，and Kv1.4 were not expressed. Conclusions: It was concluded that this greater difference in expression of ion channels at the skin tissue including specific for cutaneous peripheral nerve endings in CKD patients with CKD-aP may increase generator potential related to itching.
ARTICLE | doi:10.20944/preprints202301.0022.v1
Subject: Mathematics & Computer Science, Artificial Intelligence & Robotics Keywords: artificial intelligence; imbalanced classification; cost-sensitive learning; multimodal neural networks; skin cancer; melanoma
Online: 3 January 2023 (08:45:52 CET)
Currently, skin cancer is the most commonly diagnosed form of cancer in humans and is one of the leading causes of death in patients with cancer. Biopsy methods are an invasive research method and are not always available for primary diagnosis. Imaging methods have low accuracy and depend on the experience of the dermatologist. Artificial intelligence technologies can match and surpass visual analysis methods in accuracy, but they have the risk of a false negative response when a malignant pigmented lesion can be recognized as benign. One possible way to improve accuracy and reduce the risk of false negatives is to analyze heterogeneous data, combine different preprocessing methods, and use modified loss functions to eliminate the negative impact of unbalanced dermatological data. The paper proposes a multimodal neural network system with a modified cross-entropy loss function that is sensitive to unbalanced heterogeneous dermatological data. The accuracy of recognition in 10 diagnostically significant categories for the proposed system was 85.19%. The novelty of the proposed system lies in the use of cross-entropy loss when training the modified function with the help of weight coefficients. The introduction of weighting factors has reduced the number of false negative forecasts, as well as improved accuracy by 1.02-4.03 percentage points compared to the original multimodal systems. The introduction of the proposed multimodal system as an auxiliary diagnostic tool can reduce the consumption of financial and labor resources involved in the medical industry, as well as increase the chance of early detection of skin cancer.
REVIEW | doi:10.20944/preprints202201.0135.v1
Subject: Materials Science, Biomaterials Keywords: Wearable sensors; skin-like; heart rate monitoring; continuous glucose monitoring; battery-free sensors
Online: 11 January 2022 (12:18:36 CET)
Currently, old-style personal medicare techniques rely mostly on traditional methods, such as cumbersome tools and complicated processes, which can be time-consuming and inconvenient in some circumstances. Furthermore, such old methods need the use of heavy equipment, blood draws, and traditional bench-top testing procedures. Invasive ways of acquiring test samples can potentially cause patients discomfort and anguish. Wearable sensors, on the other hand, may be attached to numerous body areas to capture diverse biochemical and physiological characteristics as a developing analytical tool. Physical, chemical, and biological data transferred via the skin is used to monitor health in various circumstances. Wearable sensors can assess the aberrant conditions of the physical or chemical components of the human body in real-time, exposing the body state in time, thanks to unintrusive sampling and high accuracy. Most commercially available wearable gadgets are mechanically hard components attached to bands and worn on the wrist, with form factors ultimately constrained by the size and weight of the batteries required for the power supply. Wearable gadgets with “skin-like” qualities are a new type of automation that is only starting to make its way out of research labs and into pre-commercial prototypes. In this paper, we studied the recent advancement in battery-powered wearable sensors established on optical phenomena and skin-like battery-free sensors which brings a breakthrough in wearable sensing automation.
Subject: Medicine & Pharmacology, Allergology Keywords: DPTM; Methicillin-resistant Staphylococcus aureus (MRSA); Antibacterial activity; Murine skin wound model; MIC
Online: 12 April 2021 (12:18:08 CEST)
Staphylococcus aureus (S. aureus) is a major human pathogen that requires new antibiotics with unique mechanism. A new pleuromutilin derivative, 14-O-[(4,6-Diaminopyrimidine-2-yl) thioacetyl] mutilin (DPTM), has been synthesized and proved as a potent antibacterial agent using in vitro and in vivo assays. In the present study, DPTM was further in vitro evaluated against Methicillin-resistant Staphylococcus aureus (MRSA) isolated from dairy farms and outperformed tiamulin fumarate, a pleuromutilin drug used for veterinary. Moreover, a murine skin wound model caused by MRSA infection was established and the healing effect of DPTM was investigated. The results showed that DPTM could promote the healing of MRSA skin infection, reduce the bacterial burden of infected skin MRSA and decrease the secretion of IL-6 and TNF-α inflammatory cytokines in plasma. These results provided the basis for further in-depth drug targeted studies of DPTM as a novel antibacterial agent.
ARTICLE | doi:10.20944/preprints202102.0558.v1
Subject: Medicine & Pharmacology, Allergology Keywords: urinary incontinence; fecal incontinence; double incontinence; pressure skin injury; special elderly nursing home
Online: 24 February 2021 (16:56:21 CET)
Urinary and fecal incontinence as well as skin pressure injury are common healthcare problems in nursing home; however, these prevalence and related risk factors were not well understood in the Japanese special elderly nursing home settings. We surveyed the prevalence of urinary, fecal and double incontinence, and skin pressure injury among the elderly living in special elderly nursing home in Japan. A nationwide cross-sectional epidemiological survey was conducted with a total of 4,881 residents. The prevalence of urinary, fecal and double incontinence was 82.9%, 68.9% and 64.9%, respectively. Skin pressure injury was found in 283 residents (283/4881, 5.8%). Age, Care-Needs level, loss of voiding desire, and fecal incontinence were significant risk factors for urinary incontinence. Residential period, Care-Needs level, loss of voiding and defecation desires, and urinary incontinence were significant risk factors for fecal incontinence. Only male sex was a significant risk factor for skin pressure injury. Our study revealed continence status and the prevalence of pressure skin injury among older adult residents who receive an end-of-life care in special nursing homes in Japan. Further studies should be conducted to examine whether recovery of urinary and fecal sensations improves continence status.
ARTICLE | doi:10.20944/preprints202012.0217.v1
Subject: Engineering, Automotive Engineering Keywords: Eddy current sensor; defect orientation; angled crack, thin-skin regime; non-destructive testing.
Online: 9 December 2020 (10:57:15 CET)
Electromagnetic sensors have been used for inspecting small surface defects of metals. Based on the eddy-current thin-skin regime, a revised algorithm is proposed for a triple-coil drive-pickup eddy-current sensor scanning over long surface crack slots (10 mm) with different rotary angles. The method is validated by the voltage measurement of the designed EC sensor scanning over a benchmark (ferromagnetic) steel with surface defects of different depths and rotary angles. With an additional sensing coil for the designed EC sensor, the defect angle (or orientation) can be measured without spatially and coaxially rotating the excitation coil. By referring to the voltage change (due to the defect) diagram (voltage sum versus voltage different) of two sensing pairs, the rotary angle of the surface crack is retrieved with a maximum residual deviation of 3.5 %.
ARTICLE | doi:10.20944/preprints202007.0730.v1
Subject: Life Sciences, Other Keywords: TSS; fruit quality; firmness; ammonium thiosulphate; skin colour; tree vigour; thinning of flowers
Online: 31 July 2020 (04:54:38 CEST)
The study’s objective was to evaluate the influence of thinning on the quality and regularity of yield of 'Regina' cherries grown on a dwarf Gisela 5 rootstock. The experiments were conducted in the years 2009-2012 in Western Poland. Trees were thinned using a chemical agent, ammonium thiosulphate (ATS) at doses of 20g ATS × L-1, 30g ATS × L-1 and 40g ATS × L-1, and by hand, and the results of chemical and hand thinning were compared with those obtained for unthinned trees. The course of weather conditions in winter and during flowering had a significant impact on yield. Chemical thinning is known to be an effective method to regulate fruiting of pome trees, but it can also be successful if applied to cherry trees, as reflected by the alternate bearing index, which was the lowest after applying ATS at a dose of 40g. ATS treatment improved fruit quality in full crop years. Thinning resulted in, among other things, larger and darker fruit and higher content of total soluble solids and titratable acidity. Treatment with 40g ATS × L-1 significantly stimulated the vegetative growth of trees.
Subject: Engineering, Electrical & Electronic Engineering Keywords: Resistive sensor array; measurement error; zero potential methods; liquid metal; flexible electrical skin
Online: 24 January 2020 (14:49:03 CET)
Liquid metal alloy, incorporated with microfluidic manipulation, has become a promising candidate for flexible resistive sensor array (RSA) that can imitate the functions of human skin. One advantage of RSA with shared rows and shared columns is to reduce the number of wires from M × N to M + N (rows: M and columns: N) and hence to greatly lessen the complexity and burden on the electrical system. The associated drawback is the crosstalk effect between adjacent elements during measurement. Although many literatures have reported several methods to resolve this limitation, almost all of them focus only on the high resistance value (≥100 Ω) RSA. There is a lack of detailed experimental data that addresses low resistance RSA with sensing elements below 100 Ω. Here, we aim to fill the gap of this field. We established two common RSA readout systems, i.e. zero potential methods (ZPM) (setting non-scanned-sampling-electrode zero potential (S-NSSE-ZP) and setting non-scanned-sampling-electrode zero potential with amplifier (S-NSSE-ZP-A)) and to compare their performances in low resistance value (≤100 Ω) RSA. For ideal resistor RSA, the measurement results show that S-NSSE-ZP has at least one time higher error than S-NSSE-ZP-A.
ARTICLE | doi:10.20944/preprints201810.0726.v1
Subject: Life Sciences, Other Keywords: oral administration; lactic acid bacteria metabolites; skin barrier function; water content; atopic dermatitis
Online: 30 October 2018 (14:18:16 CET)
The effects of orally administered lactic acid bacteria metabolites on the skin were studied using an atopic dermatitis-like murine model created by feeding mice with HR-AD. The lactic acid bacteria metabolites were obtained by inoculating 35 strains of 16 species of lactic acid bacteria into soy milk and culturing them. The atopic dermatitis-like murine model was created by feeding HR-1 mice HR-AD for 40 days. The skin condition of mice that were fed HR-AD worsened compared with normal mice, i.e., reduced water content in the stratum corneum, increased transepidermal water loss (TEWL), reduced ceramide AP content in the stratum corneum, and increased epidermis thickness. When mice that had been fed the HR-AD diet was administered a raw liquid of lactic acid bacteria metabolites orally, the measured values related to water content in the stratum corneum, TEWL, ceramide AP content in the stratum corneum, and epidermis thickness improved. To find out the active components for these effects, filtrate and residue from the raw liquid of lactic acid bacteria metabolites and lipid components extracted from the raw liquid were examined at the same time. Results showed that the water-soluble components or residue after filtration did not demonstrate effects but the raw liquid and the lipid fraction did. These findings suggest that lactic acid bacteria metabolites improve skin injury in an atopic dermatitis-like murine model.
REVIEW | doi:10.20944/preprints201711.0096.v1
Subject: Biology, Other Keywords: Hedgehog signaling; skin; epidermis; hair follicle; development; homeostasis; basal cell carcinoma; signaling crosstalk
Online: 15 November 2017 (07:11:15 CET)
The epidermis is the outermost layer of skin and provides a protective barrier against environmental insults. It is a rapidly renewing tissue undergoing constant regeneration, maintained by several types of stem cells. Hedgehog (HH) ligands activate one of the fundamental signaling pathways that contribute to epidermal development, homeostasis and repair. The HH pathway interacts with other signal transduction pathways such as those activated by Wnt and bone morphogenetic protein. Furthermore, aberrant activation of HH signaling is associated with various tumors, including basal cell carcinoma. Therefore, an understanding of the regulatory mechanisms of the HH signaling pathway is important to elucidate fundamental mechanisms underlying both organogenesis and carcinogenesis. In this review, we discuss the role of the HH signaling pathway in skin development, homeostasis and basal cell carcinoma formation, providing an update of current knowledge in this field.
ARTICLE | doi:10.20944/preprints202212.0397.v2
Subject: Medicine & Pharmacology, Other Keywords: antibiotic therapy; diabetic foot infections; non-beta-lactam antibiotics; skin commensals; treatemet failures; associations with treatment failures
Online: 20 January 2023 (15:13:51 CET)
In diabetic foot infections (DFI), the clinically virulence of skin commensals are generally pre-sumed to be of low virulence. In this single-center study, we divided the wound isolates into two groups: skin commensals (coagulase-negative staphylococci, micrococci, corynebacteria, cutibacteria); and, pyogenicpathogenic pathogens, and followed the patients for ≥ 6 months. In this retrospective study among 1,018 DFI episodes (392 [39%] with osteomyelitis), we identified skin commensals as the sole culture isolates (without accompanying pyogenicpathogenic patho-gens) in 54 cases (5%). After treatment (antibiotic therapy [median of 20 days], hyperbaric oxy-gen in 98 cases [10%]), 251 episodes (25%) were clinical failures. Group comparisons between those growing only skin commensals and controls found no difference in clinical failure (17% vs 24 %, p=0.23) or microbiological recurrence (11% vs 17 %, p=0.23). The skin commensals were mostly treated with non-beta-lactam oral antibiotics. In multivariate logistic regression analysis, isolation of only skin commensals was not associated with failure (odds ratio 0.4, 95% confi-dence interval 0.1-3.8). Clinicians might wish to consider these isolates as potential pathogens when selecting a targeted antibiotic regimen, which may equally base on oral non-beta-lactam antibiotic agents susceptible to the corresponding skin pathogens.
ARTICLE | doi:10.20944/preprints202205.0302.v1
Subject: Mathematics & Computer Science, Artificial Intelligence & Robotics Keywords: skin cancer; melanoma; computer-aided diagnostics; image classification; CoAtNet; convolutional neural networks; deep learning
Online: 23 May 2022 (10:55:45 CEST)
Melanoma is considered to be the most aggressive form of skin cancer. Due to the similar shape of malignant and benign cancerous lesions, doctors spend considerably more time when diagnosing these findings. At present, the evaluation of malignancy is performed primarily by invasive histological examination of the suspicious lesion. Developing an accurate classifier for early and efficient detection can minimize and monitor the harmful effects of skin cancer and increase patient survival rates. This paper proposes a multi-class classification task using the CoAtNet architecture, a hybrid model that combines the depthwise convolution matrix operation of traditional convolutional neural networks with the strengths of Transformer models and self-attention mechanics to achieve better generalization and capacity. The proposed multi-class classifier achieves an overall precision of 0.901, recall 0.895, and AP 0.923, indicating high performance compared to other state-of-the-art networks.
COMMUNICATION | doi:10.20944/preprints202109.0133.v1
Subject: Medicine & Pharmacology, Clinical Neurology Keywords: cerebrospinal fluid; alpha-synuclein; skin biopsy; seeded aggregation assays; tau, amyloid; Lewy body dementia
Online: 7 September 2021 (16:26:51 CEST)
The Lewy Body Dementia Association (LBDA) held a virtual event, the LBDA Biofluid/Tissue Biomarker Symposium, on January 25, 2021, to present advances in biomarkers for Lewy Body Dementia (LBD), which includes Dementia with Lewy Bodies (DLB) and Parkinson's Disease Dementia (PDD). The meeting featured eight internationally known scientists from Europe and the United States and attracted over 200 scientists and physicians from academic centers, the National Institutes of Health and the pharmaceutical industry. Methods for confirming and quantifying the presence of Lewy body and Alzheimer pathology as well as novel biomarkers were discussed.
Subject: Life Sciences, Other Keywords: Pomegranate; Punica granatum L.; Pomegranate skin extract; Pomegranate fruit extract; Nutraceutical properties; Biological properties
Online: 8 September 2020 (05:05:55 CEST)
The pomegranate, an ancient plant native to Central Asia, cultivated in different geographical areas including the Mediterranean basin and California, consists of flowers, roots, fruits and leaves. Presently, it is utilized not only for the exterior appearance of its fruit but above all, for the nutritional and health characteristics of the various parts composing this last one (carpellary membranes, arils, seeds and bark). The fruit, the pomegranate, is rich in numerous chemical compounds (flavonoids, ellagitannins, proanthocyanidins, mineral salts, vitamins, lipids, organic acids) of high biological and nutraceutical value that make it the object of study for many research groups, particularly in the pharmaceutical sector. Its interest is mainly addressed to the knowledge of its biological and functional properties and the research of new formulations to apply it in a wide range of diseases such as neoplastic, cardiovascular, viral, inflammatory, metabolic, microbial, intestinal, reproductive and skin diseases. In this review we highlight the health-promoting properties of pomegranate and its bioactive compounds against human diseases.
ARTICLE | doi:10.20944/preprints202108.0285.v1
Subject: Engineering, Electrical & Electronic Engineering Keywords: Eddy current driver–pickup sensor; surface crack; depth measurement; thin-skin regime; non-destructive testing.
Online: 13 August 2021 (08:27:46 CEST)
Electromagnetic eddy current sensors are commonly used to identify and quantify the surface notches of metals. However, the unintentional tilt of eddy current sensors affects results of size profiling, particularly for the depth profiling. In this paper, based on the eddy current thin-skin regime, a revised algorithm has been proposed for the analytical voltage or impedance of a tilted driver–pickup eddy current sensor scanning across a long ideal notch. Considering the resolution of the measurement, the bespoke driver–pickup, also termed as transmitter-receiver (T-R) sensor is designed with a small mean radius of 1 mm. Besides, the T-R sensor is connected to the electromagnetic instrument and controlled by a scanning stage with high spatial travel resolution , with a limit of 0.2 μm and selected as 0.25 mm. Experiments have been out on the voltage imaging of an aluminium sheet with 7 machined long notches of different depths using T-R sensor under different tilt angles. By fitting the measured voltage (both real and imaginary part) with proposed analytical algorithms, the depth profiling of notches is less affected by the tilt angle of sensors. From the results, the depth of notches can be retrieved within a deviation of 10 % for tilt angles up to 60 degrees.