ARTICLE | doi:10.20944/preprints201611.0048.v2
Subject: Medicine & Pharmacology, Pharmacology & Toxicology Keywords: 2S-UTP; 4S-UTP; P2Y12 receptors; ADP; platelet aggregation
Online: 28 December 2016 (10:46:04 CET)
Platelet P2Y12 is an important ADP receptor that is involved in agonist-induced platelet aggregation and is a valuable target for the development of anti-platelet drugs. Here we characterise the effects of thio-analogues of uridine triphosphate (UTP) on ADP-induced platelet aggregation. Using human platelet-rich plasma we demonstrate that UTP inhibits P2Y12 but not P2Y1 receptors and antagonises 10 μM ADP-induced platelet aggregation in a concentration-dependent manner with an IC50 value of ~250 μM. An 8-fold higher platelet inhibitory activity was observed with a 2-thio analogue of UTP (2S-UTP), with an IC50 of 30 μM. The 4-thio analogue (4S-UTP) with an IC50 of 7.5 μM was 33-fold more effective. A 3-fold decrease in inhibitory activity, however, was observed by introducing an isobutyl group at the 4S- position. A complete loss of inhibition was observed with thio-modification of the γ phosphate of the sugar moiety, which yields an enzymatically stable analogue. The interaction of UTP analogues with P2Y12 receptors was verified by P2Y12 receptor binding and cAMP assays. These novel data demonstrate for the first time that 2- and 4-thio analogues of UTP are potent P2Y12 receptor antagonists that may be useful for therapeutic intervention.
ARTICLE | doi:10.20944/preprints202011.0706.v1
Subject: Life Sciences, Biochemistry Keywords: Chlorogenic acid; coffee; cyclooxygenase; espresso; instant coffee; platelet aggregation
Online: 30 November 2020 (08:07:40 CET)
Coffee is rich in caffeine (CF), chlorogenic acid (CGA) and phenolics. Differing types of coffee beverages and brewing procedures may result in differences in total phenolic contents (TPC) and biological activities. Inflammation and increases of platelet activation and aggregation can lead to thrombosis. We focused on determining the chemical composition, antioxidant activity and inhibitory effects on agonist-induced platelet aggregation and cyclooxygenase (COX) of coffee beverages in relation to their preparation method. We prepared instant coffee and brewed coffee beverages using drip, espresso and boiling techniques. Coffee extracts were assayed for their CF and CGA contents using HPLC, TPC using colourimetry, platelet aggregation with an aggregometer and COX activity using ELISA. The findings have shown all coffee extracts, except the decaffeinated types, contained nearly equal amounts of CF, CGA and TPC. Inhibitory effects of coffee extracts on platelet aggregation differed depending on the activation pathways induced by different agonists. All espresso, drip and boiled coffee extracts caused dose dependent inhibition of platelet aggregation induced by ADP, collagen, epinephrine, and arachidonic acid (ARA). The most marked inhibition was seen at low doses of collagen or ARA. Espresso and drip extracts inhibited collagen-induced platelet aggregation more than purified caffeine or CGA. Espresso, boiled and drip coffee extracts were also a more potent inhibitors of COX-1 and COX-2 than purified caffeine or CGA. We conclude that inhibition of platelet aggregation and COX-1 and COX-2 may contribute to anti-platelet and anti-inflammatory effects of espresso and drip coffee extracts.
REVIEW | doi:10.20944/preprints202104.0039.v1
Subject: Medicine & Pharmacology, Nutrition Keywords: Platelet function, platelet activation, platelet hyperactivity, platelet-leukocyte aggregates, inflammation, immunothrombosis, particulate air pollution, dietary antiplatelet, water-soluble tomato extract; Fruitflow; Tomato
Online: 2 April 2021 (08:12:22 CEST)
Understanding platelet functionality has undergone a sea change in the last decade. No longer are platelets viewed simply as regulators of haemostasis; they are now acknowledged to be pivotal in coordinating the inflammatory and immune responses. This expanded role for platelets brings new opportunities for controlling a range of health conditions, targeting platelet activation and their interactions with other vascular cells. Antiplatelet drugs may be of wider utility than ever expected but often cause too strong a platelet suppression to be used out of clinical settings. Dietary antiplatelets represent a nutritional approach that can be efficacious while safe for general use. Here we review potential new uses for dietary antiplatelets outside the field of cardiovascular health, with specific reference to the water-soluble tomato extract Fruitflow®. Uses in different aspects of inflammation and immune function are discussed, highlighting exercise-induced inflammation, mediating the effects of air pollution, and controlling thrombotic aspects of the immune response. Potential future developments in women’s health, erectile dysfunction, and the allergic response give an indication of how wide-ranging the utility of dietary antiplatelets can possibly be.
REVIEW | doi:10.20944/preprints202012.0136.v1
Online: 7 December 2020 (10:34:31 CET)
Emerging data have demonstrated a strong association between the gut microbiota and the development of cardiovascular disease (CVD) risk factors such as atherosclerosis, inflammation, obesity, insulin resistance, platelet hyperactivity, and plasma lipid abnormalities. Several studies in humans and animal models have demonstrated an association between gut microbial metabolites, such as trimethylamine-N-oxide (TMAO), short-chain fatty acids, and bile acid metabolites, amino acid breakdown products, with CVD. Human blood platelets are a critical contributor to the hemostatic process. Besides, these blood cells play a crucial role in developing atherosclerosis and, finally, contribute to cardiac events. Since the TMAO, and other metabolites of the gut microbiota, are associated with platelet hyperactivity, lipid disorders, and oxidative stress, the diet-gut microbiota interactions have become an important research area in the cardiovascular field. Platelets became hyperactive in people with diabetes mellitus, sedentary lifestyle, obesity, and insulin resistance and exhibited increased sensitivity at a baseline level and in response to agonists, ultimately contributing to increased aggregation plaque development. In addition to these factors, TMAO also contributes to platelet hyperactivity. Several approaches are now suggested to reduce plasma TMAO levels, such as microbiota modulation using probiotics, prebiotics, and oral broad-spectrum antibiotics. This review describes the association between microbiota-derived metabolites and CVD development.
REVIEW | doi:10.20944/preprints202112.0363.v1
Subject: Medicine & Pharmacology, General Medical Research Keywords: Platelet; ACKR3/CXCR7; Thrombosis; Thrombo-inflammation; Anti-platelet therapy; Cardiovascular disease; Coronary artery disease
Online: 22 December 2021 (12:27:01 CET)
The manifold actions of the pro-inflammatory and regenerative chemokine CXCL12/SDF-1α are executed through the canonical GProteinCoupledReceptor CXCR4, and the non-canonical ACKR3/CXCR7. Platelets express CXCR4, ACKR3/CXCR7, and are a vital source of CXCL12/SDF-1α themselves. In recent years, a regulatory impact of the CXCL12-CXCR4-CXCR7 axis on platelet biogenesis i.e. megakaryopoiesis, thrombotic and thrombo-inflammatory ac-tions have been revealed through experimental and clinical studies. Platelet surface expression of ACKR3/CXCR7 is significantly enhanced following myocardial infarction (MI) in acute coro-nary syndrome (ACS) patients, also associated with improved functional recovery and progno-sis. The therapeutic implications of ACKR3/CXCR7 in myocardial regeneration and improved recovery following an ischemic episode, are well documented. Cardiomyocytes, cardi-ac-fibroblasts, endothelial lining of the blood vessels perfusing the heart, besides infiltrating platelets and monocytes, all express ACKR3/CXCR7. This review recapitulates ligand induced differential trafficking of platelet CXCR4-ACKR3/CXCR7 affecting their surface availability, and in regulating thrombo-inflammatory platelet functions and survival through CXCR4 or ACKR3/CXCR7. It emphasizes the pro-thrombotic influence of CXCL12/SDF-1α exerted through CXCR4, as opposed to the anti-thrombotic impact of ACKR3/CXCR7. Offering an innovative translational perspective, this review also discusses the advantages and challenges of utilizing ACKR3/CXCR7 as a potential anti-thrombotic strategy in platelet associated cardiovascular dis-orders, particularly in coronary artery disease (CAD) patients post-MI.
TECHNICAL NOTE | doi:10.20944/preprints202205.0022.v1
Subject: Medicine & Pharmacology, Obstetrics & Gynaecology Keywords: menopause; infertility; platelet activation; ovarian rejuvenation
Online: 5 May 2022 (05:23:28 CEST)
Platelets are a uniquely mammalian physiologic attribute. As the only non-marine vertebrate class to experience menopause, humans have a substantial post-reproductive lifespan and are believed to have a limited, non-renewable oocyte supply. Ovarian reserve typically declines after about age 35yrs, marking losses which cannot be recovered by available fertility medications. When in vitro fertilization fails due to low or absent ovarian response, gonadotropin adjustments are often ineffectual and if additional oocytes are occasionally harvested, egg quality is usually poor. This problem was confronted by Greek researchers who developed a new surgical method to insert autologous platelet-rich plasma (PRP) into ovaries; the first ovarian PRP success to improve reproductive outcomes was published from Athens in 2016. This innovation influenced later research with condensed platelet-derived growth factors, leading to correction of oocyte ploidy error, normal blastocyst development, and additional term livebirths. Yet women’s health was among the last clinical domains to explore PRP, and its role in ‘ovarian rejuvenation’ remains unsettled. One critical aspect in this procedure is platelet activation, a commonly overlooked step in the cytokine release cascade considered essential for successful transition of undifferentiated ovarian stem cells to an oocyte lineage. Poor activation of platelets thus becomes an unforced error, potentially diminishing or even negating post-treatment ovarian follicular response. To answer this query, relevant theory, current disagreements, and new data on platelet activation are presented, along with clinical challenges for regenerative fertility practice.
ARTICLE | doi:10.20944/preprints202007.0567.v1
Online: 23 July 2020 (13:12:36 CEST)
Exercise training influences the risk of vascular thrombosis in patients with peripheral arterial disease (PAD). Mitochondrial functionalities in platelets involve the cellular bioenergetics and thrombogenesis. This study aimed to elucidate the effect of cycling exercise training (CET) on platelet mitochondrial bioenergetics in PAD patients. Forty randomly selected patients with PAD engaged in general rehabilitation (GR) with CET (i.e., cycling exercise at ventilation threshold for 30 min/day, 3 days/week) (GR+CET, n=20) or to a control group that only received GR course (n=20) for 12 weeks. Systemic aerobic capacity and platelet mitochondrial bioenergetics that included oxidative phosphorylation (OXPHOS) and electron transport system (ETS) were measured using automatic gas analysis and high-resolution respirometry, respectively. The experimental results demonstrated that GR+CET for 12 weeks significantly (i) elevated VO2peak and lowered VE-VCO2 slope, (ii) raised resting ankle-brachial index and enhanced cardiac output response to exercise, (iii) increased the distance in 6-minute walk test and raised the Short Form-36 physical/mental component scores, and (iv) enhanced capacities of mitochondrial OXPHOS and ETS in platelets by activating FADH2 (Complex II)-dependent pathway. Moreover, changes in VO2peak levels were positively associated with changes in platelet OXPHOS and ETS capacities. However, no significant changes in systemic aerobic capacity, platelet mitochondrial bioenergetics, and health-related quality of life (HRQoL) occurred following GR alone. Hence, we conclude that CET effectively increases the capacities of platelet mitochondrial bioenergetics by enhancing Complex II activity in patients with PAD. Moreover, the exercise regimen also enhanced functional exercise capacity, consequently improving HRQoL in PAD patients.
REVIEW | doi:10.20944/preprints202010.0069.v1
Subject: Medicine & Pharmacology, Allergology Keywords: platelet-rich plasma; regenerative medicine; platelet dosing; neutrophils; monocytes; lymphocytes; inflammation; angiogenesis; serotonin; analgesic effects; immunomodulation; rehabilitation.
Online: 5 October 2020 (11:00:53 CEST)
Emerging autologous cellular therapies that utilize platelet-rich plasma (PRP) applications have the potential to play adjunctive roles in a variety of regenerative medicine treatment plans. There is a global unmet need for tissue repair strategies to treat musculoskeletal (MSK) and spinal disorders, osteoarthritis (OA), and patients with chronic complex and recalcitrant wounds. PRP therapy is based on the fact that platelet growth factors (PGFs) support the three phases of wound healing and repair cascade (inflammation, proliferation, remodeling). Many different PRP formulations have been evaluated, originating from human, in vitro, and animal studies. However, recommendations from in vitro and animal research often lead to different clinical outcomes because it is difficult to translate non-clinical study outcomes and methodology recommendations to human clinical treatment protocols. In recent years, progress has been made in understanding PRP technology and the concepts for bioformulation, and new research directives and new indications have been suggested. In this review, we will discuss recent developments regarding PRP preparation and composition regarding platelet dosing, leukocyte activities concerning innate and adaptive immunomodulation, serotonin (5-HT) effects and pain killing. Furthermore, we discuss PRP mechanisms related to inflammation and angiogenesis in tissue repair and regenerative processes. Lastly, we will review the effect of certain drugs on PRP activity, and the combination of PRP and rehabilitation protocols.
REVIEW | doi:10.20944/preprints202103.0473.v1
Subject: Medicine & Pharmacology, Allergology Keywords: Pterygium; Platelet-rich membrane; Surgery; Ocular; Repair
Online: 18 March 2021 (10:59:34 CET)
Pterygium is a common ocular disease caused by abnormal cellular proliferation leading to abnormal fibrovascular growth of the conjunctiva. The main treatment is surgical removal; however, despite the improvement of surgical techniques and development of adjuvant therapies, postoperative recurrence, which can be as high as 89%, remains a challenge. Currently, pterygium excision with conjunctival autograft remains the preferred surgical technique to decrease recurrence, especially when combined with ciclosporin eye drops. Nevertheless, there is no gold standard surgical technique to prevent pterygium recurrence. Therefore, this review aims to assess the safety, effectiveness and, applicability of platelet-rich fibrin membrane for primary pterygium surgery and assess its possible benefits in resource-limited settings.
ARTICLE | doi:10.20944/preprints202110.0404.v1
Subject: Medicine & Pharmacology, Other Keywords: pathogen reduction; blood safety; platelet transfusion; INTERCEPT; plasma
Online: 27 October 2021 (12:27:33 CEST)
(1) Background: We reviewed the logistics of the implementation of pathogen inactivation (PI) using the INTERCEPT Blood System™ for platelets and the experience with routine use and clinical outcomes in the patient population at the Sírio-Libanês Hospital of São Paulo, Brazil. (2) Methods: Platelet concentrate (PC), including pathogen reduced (PR-PC) production, inventory management, discard rates, blood utilization, and clinical outcomes were analyzed over the 40 months before and after PI implementation. Age distribution and wastage rates were compared over the 10 months before and after approval for PR-PC to be stored for up to 7 days. (3) Results: A 100% PR-PC inventory was achieved by increasing double apheresis collections and production of double doses using pools of two single apheresis units. Discard rates decreased from 6% to 3% after PI implementation and further decreased to 1.2% after 7-day storage extension for PR-PCs. The blood utilization remained stable, with no increase in component utilization. A significant decrease in adverse transfusion events was observed after the PI implementation. (4) Conclusion: Our experience demonstrates the feasibility for Brazilian blood centers to achieve a 100% PR-PC inventory. All patients at our hospital received PR-PC and showed no increase in blood component utilization and decreased rates of adverse transfusion reactions.
CASE REPORT | doi:10.20944/preprints202012.0597.v1
Online: 23 December 2020 (16:12:26 CET)
Peri-implant diseases are defined as pathological inflammatory reactions in the tissue surrounding the osseointegrated implants. They are classified into two categories: mucositis - defined as peri-implant soft tissue inflammation and peri-implantitis - bone loss in the peri-implant region. A clinical case of a 61-years-old woman with an implant in the 46 anatomical position and a 5-year follow-up is presented. A probe depth of 5mm and a bone defect length of 35% was observed. The Implacure® Protocol was applied, with the main objective of eliminating the biofilm present on the exposed implant surface. There are multiple approaches to treat peri-implant diseases. While non-surgical treatment is essential for mucositis control, the treatment of peri-implantitis surgical treatment should be considered. Regenerative bone reconstruction promotes bone repair in the defect area and reduces bleeding during probing. To achieve that, autologous fibrin combined with Cerasorb M® was used. The proposed approach in the exposed clinical case involves the application of Implacure® Protocol, whose combination of the physical decontamination technique, together with the use of chlorhexidine and orthophosphoric acid, added with the combination Piperacillin + Tazobactam together with hyaluronic acid, provide a base that allows to regenerate bone using platelet-rich fibrin with Cerasorb M® and increase the survival time of the implant.
REVIEW | doi:10.20944/preprints201802.0084.v1
Subject: Medicine & Pharmacology, Cardiology Keywords: dual anti platelet therapy; acute coronary syndrome; stents
Online: 12 February 2018 (05:13:18 CET)
Percutaneous coronary intervention(PCI) with stenting for the treatment of acute coronary syndrome(ACS) is the contemporary standard of care. Such treatment is followed by Dual anti-platelet therapy(DAPT) comprising of aspirin and a P2Y12 inhibitor. The efficacy of this therapy has been well established but the optimal duration of DAPT remains elusive, and has thus far attracted a prodigious deal of scientific attention. Decision regarding DAPT duration can be challenging clinically in the modern era with the evolution of newer stents, more potent antiplatelet agents and novel anticoagulant drugs in addition to an older patient population with multiple comorbidities. Major societal guidelines have emphasized comprehensive assessment of ischemic and bleeding risk, in turn recommending individualization of DAPT duration, thus encouraging "shared decision making". The following review is aimed at critically evaluating the available evidence to help make these crucial clinical decisions regarding duration of DAPT and triple therapy.
REVIEW | doi:10.20944/preprints202011.0334.v1
Subject: Medicine & Pharmacology, Allergology Keywords: antiplatelet; aspirin; clopidogrel; ischemic stroke; TIA; platelet function analysis; antiplatelet therapy modification; secondary stroke prevention; high on-treatment platelet reactivity
Online: 12 November 2020 (09:35:12 CET)
Background: Antiplatelet medications such as aspirin and clopidogrel are used following thrombotic stroke or transient ischemic attack (TIA) to prevent a recurrent stroke. However, the antiplatelet treatments fail frequently, and patients experience recurrent stroke. One approach to lower the rates of recurrence, may be the individualized antiplatelet therapies (antiplatelet therapy modification (ATM)) based on the results of platelet function analysis (PFA). This review was undertaken to gather and analyse the evidence about the effectiveness of such approaches. Methods: We searched Medline, CINAHL, Embase, Web of Science and Cochrane databases to 7 January 2020. Results: Two observational studies involving 1136 patients were included. The overall effects of PFA-based ATM on recurrent strokes (OR 1.05; 95% CI 0.69 to 1.58), any bleeding risk (OR 1.39; 95% CI 0.92 to 2.10) or death hazard from any cause (OR 1.19; 95% CI 0.62 to 2.29) were not significantly different from the standard antiplatelet therapy without ATM. Conclusions: The two studies showed opposite effects of PFA-guided ATM on the recurrent strokes in aspirin non-responders, leading to an insignificant difference in the subgroup meta-analysis (OR 1.59; 95% CI 0.07 to 33.77), while the rates of any bleeding events (OR 1.04; 95% CI 0.49 to 2.17) or death from any cause (OR 1.17; 95% CI 0.41 to 3.35) were not significantly different between aspirin non-responders with ATM and those without ATM. There is a need for large randomized controlled trials which account for potential confounders such as ischemic stroke subtypes, technical variations in the testing protocols, patient adherence to therapy, and pharmacogenetic differences.
HYPOTHESIS | doi:10.20944/preprints202006.0253.v1
Subject: Life Sciences, Biochemistry Keywords: Platelet Activating Factor; PAF; SARS-CoV-2; Covid-19
Online: 21 June 2020 (10:27:22 CEST)
Purpose of this article is to project from the point of view of the scientific data concerning PAF and as a new approach by involving PAF, in order to contribute to clarification and proposal a possible mechanism of action of the coronavirus SARS-CoV-2 and to give a possible explanation for its observed side effects-complications of Covid-19 disease. The article is not intended to suggest any specific drugs, but clarifying the mechanism is the first step in illuminating the direction of prescribing the targets of medication that may be appropriate for the prevention, treatment, and cure of Covid-19 disease. More specifically, the purpose of this article is to provide unequivocal evidence indicating that: 1 It would not be unexpected for PAFR to participate in the entry of coronavirus SARS-CoV-2 into the cell. 2 There is interdependence and relationship of the receptors ACER and PAFR, which means the involvement of PAF in the processes related to coronavirus SARS-CoV-2 as well as to its effects exercised by the coronavirus SARS-CoV-2. 3 The receptors ACER, PAFR and TLRs are also involved in inflammation as well as in virus binding to stabilize and enter into the cell, and so they are "communicating vessels" with PAF being " a missing link" 4 Consequently there is a correlations of COVID-19 disease manifestations and biological characteristics with those caused by PAF, which shows the involvement of PAF in COVID-19 disease.
ARTICLE | doi:10.20944/preprints202005.0443.v1
Subject: Biology, Other Keywords: Mesenchymal Stromal Cells; Good Manufacturing Practice; Inactivated Platelet Lysate
Online: 27 May 2020 (08:15:13 CEST)
For their clinical use Mesenchymal Stromal Cells (MSCs), isolated from bone marrow (BM-MSCs) are considered Advanced Therapy Medicinal Products (ATMP) and need to be produced according to Good Manufacturing Practice (GMP). Human platelet lysate (HPL) represents a good GMP-compliant alternative to animal serum and after pathogen inactivation with Psoralen was more efficient and safer to produce MSCs in GMP. In this study MSCs cultivated in FBS (FBS-MSC) or inactivated HPL (iHPL-MSC), were compared for their immunomodulant properties. In particular, the effects of MSCs on: 1)proliferation of total Lymphocytes (Ly) and on naïve T Ly subsets induced to differentiate versus Th1 and Th2 Ly; 2) the immunophenotype of different T cell subsets; 3)the cytokine release to verify Th1, Th2 and Th17 polarization were analyzed by using in vitro co-culture system. We observed that iHPL-MSCs showed the same immunomodulant properties observed in the FBS-MSCs co-cultures. Although, a more efficient effect on the increase of naïve T cells and, in the Th1 cytokine release related to iHPL was observed. This study confirms that iHPL, used as medium supplement, may be considered a good alternative to FBS for a GMP-compliant MSC expansion to preserve their immunomodulant proprieties.
Subject: Medicine & Pharmacology, Other Keywords: inherited platelet disorders; hereditary thrombocytopenias; blood smear; immunofluorescence; bleeding tendency
Online: 20 January 2020 (09:50:59 CET)
Inherited platelet disorders (IPDs) are rare diseases featured by low platelet count and/or defective platelet function. Patients have variable bleeding diathesis and sometimes additional features that can be congenital or acquired. Identification of an IPD is desirable to avoid misdiagnosis of immune thrombocytopenia and use of improper treatments. Diagnostic tools include platelet function studies and genetic testing. The latter can be challenging as the correlation of its outcomes with phenotype is not easy. The immune-morphological evaluation of blood smear (by light- and immunofluorescence microscopy) represents a reliable method to phenotype subjects with suspected IPD. It is relatively cheap, not excessively time-consuming, and applicable to shipped samples. In some forms, it can provide diagnosis by itself, as for MYH9-RD, or in addition to other first-line tests as aggregometry or flow cytometry. In regard to genetic testing, it can guide specific sequencing. Since only minimal amounts of blood are needed for preparation of blood smears, it can be used to further characterize thrombocytopenia in pediatric patients and even newborns. In principle it is based on visualizing alterations in the distribution of proteins, which result from specific genetic mutations, by using monoclonal antibodies. It can be applied to identify deficiencies in membrane proteins, disturbed distribution of cytoskeletal proteins, and alpha as well as delta granules. On the other hand mutations associated with impaired signal transduction are difficult to identify by immunofluorescence of blood smears. This review summarizes technical aspects and the main diagnostic patterns achievable by this method.
Subject: Medicine & Pharmacology, Allergology Keywords: vaccine; adenovirus; COVID-19; spike; endothelial; vector; coagulation; clot; thrombopenia; platelet
Online: 15 April 2021 (14:05:48 CEST)
Prothrombotic thrombocytopathy mimicking heparin-induced thrombocytopenia has been observed in patients with severe COVID-19 and after immunisation with the Vaxzevria vaccine. Herein, we discuss the pathogenesis of this disorder focusing on the possible involvement of anti-platelet factor 4 (PF4) autoantibodies.
REVIEW | doi:10.20944/preprints202012.0343.v1
Subject: Medicine & Pharmacology, Allergology Keywords: COVID-19; platelet activating factor; thrombosis; inflammation; Mediterranean diet; PAF-inhibitors
Online: 14 December 2020 (14:16:37 CET)
The new coronavirus disease 2019 (COVID-19) pandemic is an emerging situation with high rates of morbidity and mortality, in the pathophysiology of which inflammation and thrombosis are implicated. The disease is directly connected to the nutritional status of patients and a well-balanced diet is recommended by official sources. Recently, the role of platelet activating factor (PAF) was suggested in the pathogenesis of COVID-19. In the present review several micronutrients (vitamin A, vitamin C, vitamin E, vitamin D, selenium, omega-3 fatty acids, minerals), phytonutrients and Mediterranean diet compounds (olive oil, fish, honey, plant foods) with potential anti-COVID activity are presented. We further underline that the well-known anti-inflammatory and anti-thrombotic actions of the investigated nutrients and/ or holistic dietary schemes, such as the Mediterranean diet, are also mediated through PAF. In conclusion, although there is no single food to prevent coronavirus, the aim is to follow a healthy diet containing PAF inhibitors in order to target both inflammation and thrombosis and try to avoid or/and reduce the deleterious effects of the COVID-19 epidemic.
ARTICLE | doi:10.20944/preprints201705.0037.v1
Subject: Medicine & Pharmacology, Other Keywords: autologous; buffy coat; growth factor level; platelet-rich fibrin; thrombocyte concentrate
Online: 4 May 2017 (08:37:59 CEST)
Fibrin rich of platelets (PRF®) of Choukroun represents a new step in the therapeutic concept of platelet gel with a simplified processing and biochemical changes little artificial. A valid method of preparation of the PRF must effectively separate the plates by erythrocytes and concentrate without damaging or lysing the plates themselves. In this study the experimental design is to standardize the production of L-PRF in horse directing it to human production. Our hypothesis is that the L-PRF is easy to produce in the horse, without modifications of the human protocol, thus allowing a better standardization of the human protocol. A new device for the preparation and the standardization of L-PRF clots and membranes is the L-PRF Wound Box®. The optical microscopy, most cell bodies were highlighted concentrated in the proximal portion of each membrane, the last 1/4 was observed at the center; the distal part had only residual traces of cell bodies. The L-PRF will form constantly when the phases described above are strictly adhered to. The success of the art L-PRF depends entirely on the speed of blood collection and transfer in centrifuge within a minute and by a temperature of centrifugation and compression is higher than 21°C (between 21 and 30°C). Our experiments on the horse will no doubt be able to improve our understanding on wound healing, in particularly in chronic skin lesions therapy.
ARTICLE | doi:10.20944/preprints202011.0729.v1
Subject: Medicine & Pharmacology, Allergology Keywords: osteomyelitis; buffy coat; level of growth factors; platelet-rich fibrin; thrombocyte concentrate
Online: 30 November 2020 (13:38:48 CET)
The supposition is that the usage of fibrin rich in leukocytes and platelets advanced (A-PRF) in ulcerative osteomyelitis of the diabetic foot allows rehabilitation from this critical illness. In this investigation, the focus was to normalize the use of PRF in patients with osteomyelitis not amputated, to use this second generation platelet concentrate as a regeneration enabler. The researchers submitted and utilized A-PRF membranes (1300 g × 8 min) in 7 patients (all diabetics) with osteomyelitis and cutaneous injury for 6 months. The membranes, in combination with the supernatant fluid produced by stress, have been integrated into the skin lesion down to the bone after surgical debridement. The advancement of the lesions after some period of time has been analyzed. All seven subjects had a Probe-to-Bone positive assay; MRI indicated a cortico-periosteal coagulation and/or foci of cortico-spongeous osteolysis contiguous to the lesion. Gram-positive bacterium were identified in our procedures in 52% of cases. Gram+ Cocci, for example, S. Aureus (15.6%), S. Hemolytic (12.1%), S. Viridans (7.1%), and Gram-negative Bacteria, for example, Pseudomonas (10.6%), Proteus (7.8%), Enterobacter (5.7%) are present. Candida Albicans is active in 2.8%. The blood count shows no relevant differences. To date, cutaneous lesions have cured in 6 of the seven subjects treated (one patient for more than five years) without any evidence of infection or recurrence. The results obtained on our subjects indicate that PRF membranes may be a therapeutic option in this problematic disease.
ARTICLE | doi:10.20944/preprints201902.0131.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: Platelet-rich fibrin, A-PRF, Gingival graft harvesting, Healing, Periodontal plastic surgery
Online: 14 February 2019 (10:29:29 CET)
This study aimed to investigate the healing effect of advanced platelet-rich fibrin (A-PRF) clot membranes in the reduction of palatal wounds resulting from free gingival graft (FGG) harvesting, in the re-epithelization rate and in the pain experience after surgery. Twenty-five patients requiring soft tissue augmentation (gingival recession coverage or keratinized gingiva augmentation) participated in this prospective randomized clinical study. After FGG harvesting, the test group (n=14) received A-PRF clot membranes at the palatal wound and the control group (n=11) a gelatin sponge. Epithelialization rate of the palatal wound, wound healing area, correspondent percentage of reduction and post-surgical pain experience were assessed. The follow-up period was 90 days. There was a significantly higher reduction of the palatal wound area in the A-PRF group vs. the control group, at 7 (p<0.001), 14 (p=0.009) and 30 days (p<0.001) follow-up. The maximum difference between groups was attained at 30 days (91.5% for A-PRF vs. 59.0% for the control group). At 14 days a significant difference in the proportion of patients showing total epithelization was found: 64.3% for A-PRF vs. 9.1% for the control group (p=0.012). At 90 days, both groups showed total recovery. Overall, the control group experienced a higher level of pain and discomfort until the 14th day, being significantly higher on the second day (p=0.013). The results suggest that A-PRF membranes haste the healing process by promoting a greater reduction along the recovery period and an apparent less painful postoperative period.
COMMUNICATION | doi:10.20944/preprints202207.0069.v1
Subject: Medicine & Pharmacology, Other Keywords: olfactory; smell; olfaction; anosmia; odor; rhinology; head neck surgery; otolaryngology; platelet rich plasma; recovery
Online: 5 July 2022 (08:33:30 CEST)
Objective: To describe technique of platelet rich plasma injection into the olfactory cleft in patients with long-term COVID-19 olfactory dysfunction. Methods: The technique starts with the blood extraction and the isolation of PRP through a 10-min centrifugation (4,200 rpm). The supernatant was injected in nasal regions with a 27-G needle after a local anesthesia with Xylocain 10% spray. The injection was performed through a 0° rigid optic. Precisely, several points of 0.2–0.5 mL were performed in the nasal septum in regard of the head of the middle turbine, and in the head of the middle turbine in both sides. Clinical, psychophysical and pain outcomes were evaluated pre- to post-injection. Results: A 22-year-old female with 24-month post-COVID-19 anosmia was recruited for the injection of PRP. The olfactory cleft endoscopic scale score was 0 and the threshold, discrimination and identification scores were 1, 8 and 0, respectively. The Olfactory Disorder Questionnaire score was 51. The patient benefited from the injection of 2.2 mL of PRP in nasal regions, which was done without complication. The procedure pain level was 2/10, while the local anesthesia with xylocaine 10% was judged as the most annoyance step with a score of 3/10. At 2-month post-injection, the TDI scores reached 16, 16, and 16 (48), while the Olfactory Disorder Questionnaire was 73. The patient described its recovery as very rapid, lasting 3-4 days, and occurring 3-week post-injection. Conclusion: The injection of PRP into the olfactory cleft is a safe and easiness new approach that may improve the recovery of smell sense.
REVIEW | doi:10.20944/preprints202010.0163.v1
Subject: Medicine & Pharmacology, Allergology Keywords: cholesterol; BMI; blood sugar; psychosis; LDL; HDL; antidepressants; antipsychotics; metabolism; metabolic abnormalities, platelet aggregation
Online: 8 October 2020 (09:03:41 CEST)
Patients with schizophrenia (SCZ) are at high risk of cardiovascular disease (CVD) due to an inherited predisposition, a sedentary life style and the use of antipsychotic medications. Several approaches have been taken to minimize this risk but results continue to be unsatisfactory. A potential alternative is prescribing Selective Serotonin Reuptake Inhibitors (SSRIs). SSRIs decrease platelet aggregation and reduce the risk of coronary heart disease in patients with depression. We therefore aim to investigate whether there is evidence that supports the use of SSRIs to reduce the risk for CVD in SCZ. A systematic review of the literature revealed five published reports relating to the impact of SSRIs on CV risk in SCZ. Three trials assessed the influence on metabolic parameters of fluvoxamine when combined with clozapine. Two of those studies found improvements with fluvoxamine. Of the other two reports, one indicates SSRIs as a group caused minimal but statistically significant increments in total cholesterol, LDL and triglyceride. The second report suggests that when SSRIs are combined with antipsychotics, the metabolic impact depends on the antipsychotic prescribed. While there are promising results, further studies are needed to establish the impact of SSRIs on CV risk in SCZ.
ARTICLE | doi:10.20944/preprints201803.0082.v1
Subject: Materials Science, General Materials Science Keywords: bismuth vanadate, molten salt synthesis, platelet morphology, multi-foil shape, Wulff shape, Ostwald ripening
Online: 12 March 2018 (06:46:50 CET)
10% copper substituted (BiCUVOX/Bi2V0.9Cu0.1O5.5−δ) and 5% copper/titanium double-substituted bismuth vanadate (BiCUTIVOX/Bi2V0.9(Cu0.05Ti0.05)O5.5−δ) platelets were formed by molten salt synthesis (MSS) using a eutectic KCl/NaCl salt mixture. The product was phase pure within the limits of X-ray diffraction. The size and form of the platelets could be controlled by changing the heating temperature and time. The crystallite growth rate at a synthesis temperature of 650 °C, and activation energy for grain growth were determined for BICUTIVOX, which experienced inhibited growth compared to BICUVOX. Quasi-equilibrium, multi-foil shapes consisting of lobes around the perimeter of the platelets were observed and explained in the context of relative two-dimensional nucleation and edge growth rates.
REVIEW | doi:10.20944/preprints202106.0725.v1
Subject: Life Sciences, Biochemistry Keywords: mRNA vaccine; viral vector vaccine; Spike protein; antigen presentation; polyethylene glycol; platelet factor 4; thrombosis
Online: 30 June 2021 (09:46:15 CEST)
Infection with Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2) causes Coronavirus Disease 2019 (COVID-19), which has reached pandemic proportions. A number of effective vaccines have been produced, including mRNA vaccines and viral vector vaccines, which are now being implemented on a large scale in order to control the pandemic. The mRNA vaccines are composed of the Spike S1 protein encoding mRNA, incorporated in a lipid nanoparticle, stabilized by polyethylene glycol (PEG). mRNA vaccines are novel in many respects, including cellular uptake, the intracellular routing, processing, and secretion of the viral protein. Viral vector vaccines have incorporated DNA sequences encoding the SARS-CoV-2 Spike S1 protein into (attenuated) adenoviruses. The antigen presentation routes in MHC class I and class II, in relation to induction of virus neutralizing antibodies and cytotoxic T-lymphocytes will be reviewed. In rare cases, mRNA vaccines induce unwanted immune mediated side effects. mRNA based vaccines may lead to an anaphylactic reaction. This reaction may be triggered by PEG. The intracellular routing of PEG, and potential presentation in the context of CD1 will be discussed. Adenovirus vector based vaccines have been associated with thrombocytopenic thrombosis events. The anti-platelet factor 4 antibodies found in these patients could be generated due to conformational changes of relevant epitopes presented to the immune system.
ARTICLE | doi:10.20944/preprints202208.0070.v1
Subject: Medicine & Pharmacology, Cardiology Keywords: adipocyte-derived mesenchymal stem cells; cardiomyocyte-like cells; platelet rich fibrin; growth factor; stem cell therapy
Online: 3 August 2022 (03:31:51 CEST)
Background: There is several challenges to solve irreversible loss of cardiomyocytes due to myocardial infarction. Cell therapy is believed as an ideal treatment for cardiac regeneration in the infarct area. Obtaining adipose-derived stem cells increases seems to be promising, however it is limited by the capacity to differentiate. Stimulation by injectable platelet-rich fibrin appears to have the beneficial effects to accelerate cardiomyocyte-like cells differentiation. Objective: To analyse the benefit of injectable platelet-rich fibrin to accelerate differentiation of adipose-derived mesenchymal stem cells into cardiomyocyte-like cells. Methods: This study is a true experimental randomized post-test design study. Adipose-derived mesenchymal stem cells were isolated from adipose tissues and cultured until 4 passages. The characteristics of adipose-derived mesenchymal stem cells were measured by the expression of CD 34-, CD 45-, and CD 105+ using flowcytometry. The samples were divided into 3 groups, i.e. negative control (α-MEM), positive control (differentiation medium) and treatment group (platelet-rich fibrin). The assessment of GATA-4 marker expression was conducted using flowcytometry on the fifth day and troponin was conducted using immunocytochemistry on the tenth day to determine the differentiation to cardiomyocyte. Data analysis was conducted using T-test and One-Way ANOVA on normally distributed data determined through Shapiro-Wilk test. Results: Flowcytometry on GATA-4 expression revealed significant difference on addition of platelet-rich fibrin compared with negative and positive controls (68.20 ± 6.82 vs 58.15 ± 1.23; p<0.05; 68.20 ± 6.82 vs 52.96 ± 2.02; p<0.05). This was supported by the results of immunocytochemistry on troponin expression which revealed significant difference between platelet-rich fibrin group compared with negative and positive controls (50.66 ± 7.2 vs 10.73 ± 2.39; p<0.05; 50.66 ± 7.2 vs 26.00 ± 0.4; p<0.05). Conclusion: Injectable platelet-rich fibrin has beneficial effect to accelerate differentiation of adipose-derived mesenchymal stem cells into cardiomyocyte-like cells.
ARTICLE | doi:10.20944/preprints202105.0144.v1
Subject: Medicine & Pharmacology, Allergology Keywords: luminal breast cancer; neoadjuvant therapy; neutrophil to lymphocyte ratio (NLR); platelet to lymphocyte ratio (PLR); predictive/prognostic biomarkers
Online: 7 May 2021 (12:26:14 CEST)
Neutrophil to lymphocyte ratio (NLR) is a promising predictive and prognostic factor in breast cancer. We investigated its ability to predict disease-free survival (DFS) and overall survival (OS) in patients with luminal A or luminal B-HER2-negative breast cancer who received neoadjuvant chemotherapy (NACT). Pre-treatment complete blood cell counts from 168 consecutive patients with luminal breast cancer were evaluated to assess NLR. The study population was stratified into NLRlow or NLRhigh according to a cut-off value established by receiving operator curve (ROC) analysis. Data on additional pre- and post-treatment clinical-pathological characteristics were also collected. Kaplan-Meier curves, log-rank tests, and Cox proportional hazards models were used for statistical analyses. Patients with pre-treatment NLRlow showed a significantly shorter DFS (HR 6.97, 95% CI 1.65-10.55, p= 0.002) and OS (HR 7.79, 95% CI 1.25-15.07, p= 0.021) compared to those with NLRhigh. Non-ductal histology, luminal B subtype, and post-treatment Ki67≥ 14% were also associated with worse DFS (p= 0.016, p= 0.002, and p= 0.001, respectively). In multivariate analysis, luminal B subtype, post-treatment Ki67≥ 14%, and NLRlow remained independent prognostic factors for DFS, while only post-treatment Ki67≥ 14% and NLRlow affected OS. The present study provides evidence that pre-treatment NLRlow helps identify women at higher risk of recurrence and death among patients affected by luminal breast cancer treated with NACT.
ARTICLE | doi:10.20944/preprints202103.0354.v1
Subject: Biology, Anatomy & Morphology Keywords: Endometrial Mesenchymal Stromal Cells; Good Manufacturing Practice (GMP); infertility; Asherman’s syndrome, endometrial thickness; Human platelet lysate (HPL); endometrial sampling
Online: 12 March 2021 (20:51:55 CET)
The cyclic regeneration of human endometrium is guaranteed by the proliferative capacity of Endometrial Mesenchymal Stromal Cells (E-MSCs). Due to this, the autologous infusion of E-MSCs has been proposed to support endometrial growth in a wide range of gynecological diseases. We aimed to compare two different endometrial sampling methods, the surgical curettage and the Vacuum Aspiration Biopsy Random Assay, and to validate a novel xeno-free method to culture human E-MSCs. Six E-MSCs cell lines were isolated after a mechanical tissue homogenization and cultured using human platelet lysate. E-MSCs were characterized for the colony formation capacity, proliferative potential and multilineage differentiation. The expression of mesenchymal and stemness markers was tested by FACS analysis and Real-Time PCR, respectively. Chromosomal alterations were evaluated by karyotype analysis, whereas tumorigenic capacity and invasiveness were tested by soft agar assay. Both endometrial sampling techniques allowed to efficiently isolate and expand E-MSCs using a xeno-free method preserving their mesenchymal and stemness phenotype, proliferative potential and multi-lineage differentiation ability during the culture. No chromosomal alterations and invasive/tumorigenic capacity were observed. Herein we report the first evidence of efficient E-MSCs isolation and culture in Good Manufacturing Practice compliance conditions, suggesting Vabra endometrial sampling as alternative to surgical curettage.
REVIEW | doi:10.20944/preprints201709.0027.v1
Subject: Life Sciences, Biotechnology Keywords: EVs; endothelial-derived microparticles; platelet-derived microparticles; non-invasive biomarkers; miRNAs signature; diabetes associated complications; micro-macrovascular damage; diabetic nephropathy
Online: 8 September 2017 (09:38:47 CEST)
Extracellular vesicles (EVs) represent a heterogeneous population of small vesicles, consisting of a phospholipidic bilayer surrounding a soluble interior cargo. Almost all cell types release EVs, thus they are naturally present in all body fluids. Among the several potential applications, EVs could be used as drug delivery vehicles in disease treatment, in immune therapy because of their immunomodulatory properties and in regenerative medicine. In addition to general markers, EVs are characterized by the presence of specific biomarkers (proteins, miRNAs) that allow the identification of their cell- or tissue-origin. For these features, they represent a potential powerful diagnostic tool to monitor state and progression of specific diseases. As regards, a large body of studies supports the idea that endothelial derived (EMPs) together with platelet-derived microparticles (PMPs) are deeply involved in the pathogenesis of diseases characterized by micro- and macrovascular damages, including diabetes. Existing literature suggests that the detection of circulating EMPs and PMPs and their specific miRNA profile may represent a very useful non-invasive signature to achieve informations about the onset of peculiar disease manifestations. In this Review, we discuss the possible utility of EVs in the early diagnosis of diabetes-associated microvascular complications, specifically related to kidney.
ARTICLE | doi:10.20944/preprints202006.0199.v1
Subject: Medicine & Pharmacology, Cardiology Keywords: C-reactive protein; platelet to lymphocyte ratio; neutrophil to lymphocyte ratio; hematocrit; red blood cell distribution width; contrast induced nephropathy; coronary intervention
Online: 16 June 2020 (07:51:20 CEST)
Background: Strong indicators of inflammation, such as C-reactive protein (CRP), hypersensitive CRP (hs-CRP), and a series of hematological indices, including platelet to lymphocyte ratio (PLR), neutrophil to lymphocyte ratio (NLR), hematocrit (HCT) and red blood cell distribution width (RDW), are regarded related with the incidence of contrast induced nephropathy (CIN) closely. Whereas, it remains unclear whether they can function as predictors of CIN onset. The objective of this meta-analysis was to determine the relationship between above indicators and CIN incidence among patients receiving coronary intervention. Methods: Clinical studies were retrieved from the electronic databases of PubMed, EMBASE, Google Scholar, Clinical Trials, and science direct from their inception to June 3rd, 2020. Meta-analysis was performed on pool eligible studies. Two reviewers screened all titles and abstracts and independently assessed all articles. Results: A total of 26 studies involving 29,454 patients were included in the meta-analysis. Pooled analysis results revealed that patients with higher CRP (odds ratio [OR]=1.06, 95% confidence interval [CI]: 1.01–1.12, P=0.02), hs-CRP (OR=1.03, 95% CI: 1.01–1.06, P=0.004), NLR (OR=1.11, 95% CI: 1.01–1.20, P=0.02), RDW (OR=1.35, 95% CI: 1.19–1.53, P<0.00001), and lower HCT (OR=0.94, 95% CI: 0.92–0.97, P=0.0003) all exhibited significantly higher CIN rates, but there was no significant association between PLR and CIN risk (OR=1.12, 95% CI: 0.99–1.26, P=0.07). Conclusion: The meta-analysis reported here demonstrates that pre-angiography CRP/hs-CRP and some hematological indices are associated with CIN.
REVIEW | doi:10.20944/preprints202203.0135.v1
Subject: Medicine & Pharmacology, Nutrition Keywords: Aspirin; COVID-19; Human blood platelets; Platelet hemostatic function; Angiogenesis; Fatty acids; Immunity; Inflammation; Non-hemostatic function; Atherosclerosis; Cancer; Diabetes; Obesity; Hypertension; Bioactive compound; Water-soluble tomato extract; Kiwi fruit; Fruitflow®; papaya leaf extract; Polyphenols; Evodiamine; Polyphenols
Online: 10 March 2022 (02:42:26 CET)
Platelets have long been associated with sustaining the balance between hemostasis and thrombosis. Platelets, however, are also involved in a wide range of biological activities, including inflammation, immunology, wound healing, cancer biology, and angiogenesis. Platelets' diverse roles are mediated by the expression of various adhesive and immune receptors and the secretion of a diverse array of bioactive proteins, ions stored in granules, and several lipid mediators. Platelets also release pro-inflammatory and anti-inflammatory, and angiogenic factors and shed microparticles into the bloodstream. The challenge for therapeutic intervention in non-hemostatic disease is identifying the factors that primarily inhibit specific targets implicated in platelets' complicated contribution to inflammation or tumor growth while leaving their hemostatic function intact. In addition, blood platelets are involved in infection and innate and adaptive immunity by mediating complicated vascular homeostasis via specialized receptors and granule release, RNA transfer, and mitochondrial secretion. Anti-platelet drugs/bioactive compounds are developed based on their platelet anti-aggregatory properties; however, very little information is available on their effects on non-hemostatic function. Therefore, a better understanding of the impact of the anti-platelet bioactive on the platelets' diverse roles and mechanisms may help develop new strategies and prevent CVD and other diseases. In this review, a comprehensive overview of platelet multifunctional roles in CVD and other diseases and dietary factors' modulatory effects are described.
ARTICLE | doi:10.20944/preprints202211.0236.v1
Subject: Medicine & Pharmacology, General Medical Research Keywords: Acute exacerbation chronic obstructive pulmonary disease (AECOPD); platelet-to-lymphocyte ratio (PLR); neutrophil-to-lymphocyte ratio (NLR); monocyte-to-lymphocyte ratio (MLR); baso-phil-to-lymphocyte ratio (BLR); eosinophil-to-lymphocyte ratio (ELR); in-hospital mortality; nom-ogram; decision curve analysis (DCA); clinical impact curve (CIC)
Online: 14 November 2022 (04:42:59 CET)
The study comprehensively evaluated the prognostic roles of PLR, NLR, MLR, BLR, and ELR in patients with acute exacerbation chronic obstructive pulmonary disease (AECOPD). 619 patients with AECOPD and 300 healthy volunteers were retrospectively included into the study. The clinical characteristics containing laboratory findings of the AECOPD patients and the blood cell counts (CBCs) of the healthy volunteers were collected. Compared with the healthy volunteers, PLR, NLR, and MLR were elevated in COPD patients in stable condition, and were further ele-vated during exacerbation. ELR showed the opposite trend. PLR, NLR, and MLR were all posi-tively correlated with hospital LOS as well as CRP. In contrast, ELR was negatively correlated with hospital LOS as well as CRP. Elevated PLR, NLR, and MLR were all associated with more serious airflow limitation in AECOPD. Elevated PLR, NLR, and MLR were all associated with increased in-hospital mortality while Elevated ELR was associated with decreased in-hospital mortality in AECOPD. A nomogram was construct to predict in-hospital mortality in AECOPD. The nomo-gram had a C-index of 0.850 (95% CI: 0.799 – 0.901) with good predictive value and clinical ap-plicability. In summary, PLR, NLR, MLR, and ELR served as predictors for clinical outcomes in patients with AECOPD.