ARTICLE | doi:10.20944/preprints201810.0392.v1
Subject: Medicine And Pharmacology, Clinical Medicine Keywords: albumin; mortality; necrotizing fasciitis
Online: 17 October 2018 (17:18:59 CEST)
Background: Hypoalbuminemia is known to be associated with adverse outcome in critical illness. In this study, we attempted to identify if hypoalbuminemia on emergency department (ED) arrival a reliable predictor for in-hospital mortality in necrotizing fasciitis (NF). patients. Method: A retrospective cohort study of hospitalized patients with NF was conducted in a tertiary teaching hospital in Taiwan between March 2010 and March 2018. Blood samples were collected in the ED upon arrival, and serum albumin levels were determined. we evaluated the predictive value of serum albumin level at ED presentation for in-hospital mortality. All collected data were statistically analyzed. Result: Of the 707 NF patients, 40 (5.66%) died in the hospital. The mean serum albumin level was 3.1 ± 0.9 g/dL and serum albumin levels were significantly lower in the non-survivor group than in the survivor group (2.8± 0.7 g/dL vs. 3.5 ± 0.8 g/dL). In the multivariable logistic regression model, albumin was associated with in-hospital mortality significantly (odds ratio[OR] 0.92, 95% confidential interval (CI) 0.88–0.96, P <0.001). The area under-the-receiver-operating-characteristic curve (AUC) for in-hospital survival was 0.77 (95% CI 0.72–0.82) and corresponding sensitivity, specificity, positive predictive value, negative predictive value, positive and negative likelihood ratio were 66%, 74%, 33%, 88%, 2.25 and 0.48, respectively. High sensitivity (96%) was shown at albumin level of 4.0 g/dL and high specificity (91%) was shown at level of 2.5 g/dL. Conclusion: Initial serum albumin levels were independently associated with in-hospital mortality among adult patients with necrotizing fasciitis and demonstrated fair discriminative performance in the prediction of in-hospital mortality. NF patients with hypoalbuminemia on ED arrival should be closely monitored for signs of deterioration and consider early and aggressive intervention to prevent mortality.
REVIEW | doi:10.20944/preprints202209.0125.v1
Subject: Medicine And Pharmacology, Gastroenterology And Hepatology Keywords: Human serum albumin; COVID-19 vulnerabilities; fluid therapy; albumin binding deficiency; lymphatic nutrient pump; colloid pressure; interstitial spaces; albumin infusion; hepatic portal vein
Online: 8 September 2022 (13:40:16 CEST)
COVID-19 and long COVID-19 vulnerabilities may be caused indirectly by albumin binding deficiency (ABD) which can be corrected by the correct administration of human serum albumin (HSA). The liver is the primary site of nutrient regulation and fluid volume maintenance, control of both is by changes to albumin concentration. In healthy subjects the HSA lymphatic nutrient pump (HSALNP) ensures continual pumping of nutrients from the liver are appropriately distributed to organs. Nutrients are delivered to cells according to the availability of binding to HSA. The HSALNP therefore maintains the correct nutrients and colloidal pressure balance in all tissues independently. In unhealthy tissues, following COVID-19 infection, the passage of HSA/nutrients through the interstitial spaces and lymph will be impeded. Fluid therapy into the periphery leads to dilution of essential nutrients attached to the protein-carriers such as albumin. The levels of albumin being charged by the liver with nutrients is critical in maintaining immune stability by maintaining nutrient support and colloidal pressure of cellular structures. The site of HSA binding by the liver is of great importance and direct infusion of albumin into the Hepatic Portal Vein is the most appropriate method of maintaining colloid pressure and cellular nutrient levels.
REVIEW | doi:10.20944/preprints202302.0354.v1
Subject: Medicine And Pharmacology, Clinical Medicine Keywords: Albumin; Covid; Albumin Binding Disease; insulin; diabetes; fluid therapy; saline; plasma; blood volume; nutrition; cellular
Online: 21 February 2023 (08:24:48 CET)
Human serum albumin (HSA) is the ultimate, homeostatic determinant of fluid volume (FV) in all compartments of the body. The ability to change the pressure and flow of nutrient medium to cellular structures selectively has clinical significance in almost all areas of clinical medicine. We have shown that present fluid therapy (FT) using either colloid or saline dilutes nutrients. HSA binds and delivers nutrients, a lack of HSA binding causes Albumin Binding Disease (ABD) changing both colloidal pressure and nutrients leading to symptoms of sepsis. A reduction in HSA binding can be through lack of HSA or external ligands taking up binding sites on HSA. Many diseases cause ABD when immunoglobulins, infectious particles and by products bind to HSA including COVID-19 and other bacterial diseases like streptococcus as well as metabolic and cardiac disease due to incorrect pressure and nutrients. To raise HSA binding potential and remove vulnerabilities to these diseases we propose raising HSA. We show how present methods of fluid therapy (FT) are inefficient in that control of both pressure and nutrients forms initial equilibrium in the liver. HSA production and binding to nutrients is maintained at a level by the pressure in hepatocytes with the pancreatic and adrenal hormones moderating. Glucose and Ke-tone production are critical in the management of HSA binding and control of blood, colloidal pressure, and health of cells. Ketones provide a distinct mechanism of liver to lungs-heart metabolism during hypoglycaemia and activity. This known chain of nutrition becomes critical during disease like acute respiratory distress syndrome (ARDS) when ketones may be overproduced. HSA must therefore be infused into the liver to raise HSA levels safely. We investigated the control of HSA as a product of the actions of pressure in hepatocytes and changes in pancreatic and adrenal hormones. We found that in addition to pressure during glucose abundancy HSA is re-leased with ketones on administration of insulin and consider that this mechanism retains HSA moderation. HSA can therefore be increased by increasing insulin in the presence of glucose in the correct amounts. We suggest a protocol to increase FV, blood, lymph volume by infusion of HSA, insulin, and glucose direct to the liver so that the level of HSA stabilises. We suggest this will raise all other nutrients in the new FV, blood, lymph culminating in the creation of new blood cells. We propose that in a clinical situation maintaining this protocol will alleviate the symptoms of ABD and decrease the likelihood of serious illness and death.
ARTICLE | doi:10.20944/preprints202103.0309.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: CXCR4; EPI-X4; human serum albumin
Online: 11 March 2021 (10:55:07 CET)
Background: Endogenous Peptide Inhibitor of CXCR4 (EPI-X4) is a natural antagonist of the CXC chemokine receptor 4 (CXCR4). EPI-X4 is a 16-mer peptide that is released from human serum albumin (HSA) by acidic aspartic proteases such as Cathepsin D and E. Since human serum albumin (HSA) is an important medicinal substance we asked whether different pharmaceutical HSA products contain EPI-X4 which could have been generated during manufacturing and whether HSA can serve as a substrate for cathepsins despite of the presence of stabilizers like caprylate. Methods: Eight pharmaceutical HSA preparations representing all currently used fractionation technologies were analyzed. The previously described specific EPI-X4 ELISA was used for quantification; in vitro EPI-X4 generation by acidification in the presence or absence of cathepsins was followed by quantification with ELISA. Results: None of the pharmaceutical HSA preparations tested contained EPI-X4. Acidification of HSA did not generate EPI-X4. Addition of cathepsins D and E to acidified HSA yielded high concentrations of EPI-X4 in all HSA preparations, indistinguishable between individual products. Conclusion: Medicinal HSA preparations per se do not contain EPI-X4, but will replenish its precursor which can be cleaved to EPI-X4 in vivo, environmental conditions permitting.
ARTICLE | doi:10.20944/preprints202203.0342.v1
Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: albumin-globulin ratio; postoperative pancreatic fistula; pancreaticoduodenectomy
Online: 25 March 2022 (09:00:37 CET)
Background and aim: The albumin-globulin ratio (AGR) is one of the indicators of inflammation and immunity and it has a prognostic significance in many malignant diseases. Previous studies have shown the relationship between inflammatory mediators and POPF. This study aimed to evaluate the relation of AGR, which is a relatively new indicator, with postoperative pancreatic fistula (POPF). Methods: Pancreaticoduodenectomy (PD) patients between 2017 and 2020 were retrospectively analyzed and divided into two groups as those with and without clinically relevant POPF (CR-POPF). They were compared in terms of preoperative-postoperative AGR and clinicodemographic characteristics. AGR was calculated as Albumin / (Total protein-albumin) and the cutoff point for AGR was determined according to Youden’s index. Results: CR-POPF developed in 21% of 121 patients who underwent PD. There was no difference between the groups in terms of age, gender, comorbid disease status, pancreatic duct width, and anastomosis technique. Preoperative and postoperative day-3 (POD3) albumin levels and AGR were found to be significantly lower in the CR-POPF group. Multivariate analysis showed that AGR and pancreatic tissue stiffness are independent risk factors for the development of POPF. Conclusions: Low AGR is an independent risk factor for the development of CR-POPF. To reduce the incidence of POPF, this ratio should be tried to be kept at an optimal level.
ARTICLE | doi:10.20944/preprints202210.0058.v1
Subject: Medicine And Pharmacology, Pharmacology And Toxicology Keywords: EPI-X4; albumin carrier; peptide stability; CXCR4 antagonist;
Online: 6 October 2022 (08:50:49 CEST)
Advanced derivatives of the CXCR4 antagonist EPI-X4 have shown therapeutic efficacy upon topical administration in animal models of asthma and dermatitis. Here, we studied plasma stability of the EPI-X4 lead compounds WSC02 and JM#21, using mass spectrometry to monitor the chemical integrity of the peptides and a functional fluorescence-based assay that determines peptide function in a CXCR4-antibody competition assay. Although mass spectrometry revealed a very rapid disappearance of both peptides in human plasma within seconds, the functional assay revealed a significantly higher half-life of 9 minutes for WSC02 and 6 minutes for JM#21, respectively. Further analyses demonstrated that WSC02 and JM#21 interact with low molecular weight plasma components and serum albumin. Albumin binding is mediated by the formation of a disulfide bridge between Cys10 in the EPI-X4 peptides and Cys34 in albumin. These covalently linked albumin-peptide complexes have a higher stability in plasma as compared to the non-bound peptides and retain the ability to bind and antagonize CXCR4. Remarkably, chemically synthesized albumin-EPI-X4 conjugates coupled by non-breakable bonds have a drastically increased plasma stability of over 2 hours. Thus, covalent coupling of EPI-X4 to albumin in vitro before administration or in vivo post administration may significantly increase the pharmacokinetic properties of the new class of CXCR4 antagonists.
Subject: Physical Sciences, Biophysics Keywords: conformation of protein; albumin protein; non-gaussian chain
Online: 7 August 2019 (09:59:10 CEST)
We study a conformation of an albumin protein in the temperature range of 300K-315K, i.e. in the physiological range of temperature. Using simulations we calculate values of two backbone angles, that carry most of information about positioning of the protein chain in a conformational space. Given these, we calculate energy components of such protein. Further, using the Flory theory we determine the temperature in which investigated albumin chain model is closest to the free joined chain model. Near the Flory temperature, we study energy components and the conformational entropy, both derived from two angles that reflect most of the chain dynamics in a conformational space. We show that the conformational entropy is an oscillating function of time in considered range of temperature. Our finding is that, the only regular oscillation pattern appears near the Flory temperature.
ARTICLE | doi:10.20944/preprints202108.0291.v1
Subject: Biology And Life Sciences, Biology And Biotechnology Keywords: ferulic acid; UVA light; cyclic peptide; bovine serum albumin
Online: 13 August 2021 (08:48:39 CEST)
Ferulic acid (FA) is known for its excellent antioxidant properties that can provide a lot of health benefits. One of its drawbacks is being unstable under UVA light that limits its potency. In this study, new peptides LW2 (QNKRFYFRKNQ) and CW2 (a cyclic form of LW2) have been designed based on bovine serum albumin site ⅡA conformation. UVA irradiation experiment was performed to investigate the protective ability of these peptides towards FA against UVA damage. The percentage of FA remaining under UV irradiation by the protection of CW2 and LW2 was 83%, 76% respectively. The results showed the importance of the cationic residues and hydrophobic residues included in the peptide sequences. Moreover, the cyclic rigid structure showed more protecting ability over that of the linear counterpart.
ARTICLE | doi:10.20944/preprints201911.0020.v1
Subject: Chemistry And Materials Science, Surfaces, Coatings And Films Keywords: magnesium; Covalent bonds; anti-corrosion; biocompatibility; bovin serum albumin
Online: 3 November 2019 (16:01:41 CET)
Herein, we describe precisely on covalent modification of pure magnesium (Mg) surface and applied to induce in vitro osteogenic differentiation. A new concept, chemical bonding method is proposed for developing stable chemical bonds on Mg surface through serial assembly of bioactive additives including ascorbic acid (AA) and bovine serum albumin (BSA). The coating with such potential materials shows strong integrity to the Mg and could suitable for cell-interface interaction with the host tissue during implantation in bone tissue repair. The physicochemical and electrochemical properties of surface modified Mg assess how these nanoscales layered of biomolecules could demonstrate the significance improvement in chemical stability of coating. The modified Mg-OH-AA-BSA exhibits better anti-corrosion behavior with high corrosion potential (Ecorr ~ ‒ 0.96 V) and low corrosion current density (Icorr ~ 0.2 µA cm-2) as compared to pure Mg (Ecorr ~ ‒1.46 V, Icorr ~ 10.42 µA cm-2). Outer layer of BSA on Mg protects fast degradation rate of Mg which is the consequence of strong chemicals bonds between amine groups on BSA with carboxylic groups on AA. Collectively, the results suggest that surface modified Mg provides strong bio-interface and enhances the proliferation and differentiation of pre-osteoblast (MC3T3-E1) cells through protein-lipid interaction. Owing to this fact, the cost-effective and scalable covalent functionalization of Mg surface inherits biological advantage in orthopedic and dental implants with long term stability.
ARTICLE | doi:10.20944/preprints202103.0552.v1
Subject: Biology And Life Sciences, Anatomy And Physiology Keywords: Huma Serum Albumin; Acinetobacter baumannii; quorum sensing; iron; human fluids.
Online: 22 March 2021 (15:49:16 CET)
Acinetobacter baumannii is a nosocomial pathogen capable of causing serious infections associated with high rates of morbidity and mortality. Due to its antimicrobial drug resistance profile, A. baumannii is categorized as an urgent priority pathogen by the Centers for Disease Control and Prevention in the United States and priority group 1 critical microorganism by the World Health Organization. Understanding how A. baumannii adapts to different host environments may provide critical insights into strategically targeting this pathogen with novel antimicrobial and biological therapeutics. Exposure to human fluids was previously shown to alter the gene expression profile of a highly drug susceptible A. baumannii strain A118 leading to persistence and survival of this pathogen. Herein, we explore the impact of human pleural fluid (HPF) and human serum albumin (HSA) on the gene expression profile of a highly multi-drug resistant strain of A. baumannii AB5075. Differential expression was observed for ~30 genes, whose products are involved in quorum sensing, quorum quenching, iron acquisition, fatty acid metabolism, biofilm formation, secretion systems and type IV pilus formation. Phenotypic and further transcriptomic analysis using quantitative RT-PCR confirmed RNA-seq data and pointed out a distinctive role of HSA as the molecule involved in A. baumannii response.
ARTICLE | doi:10.20944/preprints201702.0070.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: albumin; oxidative stress; exercise; ultra-marathon mountain race; protein oxidation
Online: 17 February 2017 (15:02:03 CET)
The aim of this study was to examine the oxidation of human serum albumin (HSA) caused by oxidative stress after an exhaustive exercise such as ultra-marathon race. Thus, blood samples from 12 adult runners who underwent a 103 km mountain ultra-marathon race were collected pre- and 24, 48 and 72 h post race. HSA was partially purified using affinity chromatography and then was subjected to Western blot analysis for disulfide dimers determination, indicating oxidation. The results were correlated with those from a previous study in which the same samples were analyzed using different oxidative stress markers and a good correlation with protein carbonyls (PC) at all time points was observed. Moreover there was a significant correlation with static oxidation-reduction potential (sORP) at 24 h, and a negative correlation with capacity oxidation-reduction potential (cORP) at 24 and 48 h. In addition, an individual analysis of albumin dimers exhibited great inter-individual differences. This inter-individual variability in the oxidation of HSA may suggest different interventions (e.g. through diet) in order to confront the effects on athletes’ organism after a strenuous exercise. In conclusion, this study supported the importance of the assessment of albumin dimers as a predictive marker for exercise-induced oxidative stress.
REVIEW | doi:10.20944/preprints202005.0363.v1
Subject: Medicine And Pharmacology, Ophthalmology Keywords: Ocular Surface; Tear Film; Albumin; Pharmacology; Animal Models; Translational Research; One Health
Online: 23 May 2020 (05:59:39 CEST)
Preclinical animal studies provide valuable opportunities to better understand human diseases and contribute to major advances in medicine. This review provides a comprehensive overview of ocular parameters in humans and selected animals, with a focus on the ocular surface, detailing species differences in ocular surface anatomy, physiology, tear film dynamics and tear film composition. We describe major pitfalls that tremendously limit the translational potential of traditional laboratory animals (ie., rabbits, mice and rats) in ophthalmic research, and highlight the benefits of integrating companion dogs with clinical analogues to human diseases into preclinical pharmacology studies. This One Health approach can help accelerate and improve the framework in which ophthalmic research is translated to the human clinic. Studies can be conducted in canine subjects with naturally occurring or non-invasively induced ocular surface disorders (eg., dry eye disease, conjunctivitis), reviewed herein, and tear fluid can be easily retrieved from canine eyes for various bioanalytical purposes. In this review, we discuss common tear collection methods, including capillary tubes and Schirmer tear strips, and provide guidelines for tear sampling and extraction to improve the reliability of analyte quantification (drugs, proteins, others).
ARTICLE | doi:10.20944/preprints202212.0368.v1
Subject: Medicine And Pharmacology, Hematology Keywords: Betulinic acid; bovine serum albumin; doxorubicin; drug delivery system; lung cancer; synergistic effect.
Online: 20 December 2022 (10:40:12 CET)
Nanosized drug delivery systems (DDS) have been studied as a novel strategy against cancer due to their potential to simultaneously decrease drug inactivation and systemic toxicity and increase passive and/or active drug accumulation within the tumor(s). Triterpenes are plant-derived compounds with interesting therapeutic properties. Betulinic acid (BeA) is a pentacyclic triterpene which has great cytotoxic activity against different cancer types. Herein, we developed a nanosized protein-based DDS of bovine serum albumin (BSA) as the drug carrier combining two compounds: doxorubicin (Dox) and the triterpene BeA using an oil-water-like micro-emulsion method. Spectrophotometric assays were performed to determine protein and drug concentrations in the DDS. The biophysical properties of these DDS were characterized using dynamic light scattering (DLS) and circular dichroism (CD) spectroscopy confirming nanoparticle (NP) formation and drug loading into the protein structure, respectively. The encapsulation efficiency was 77% for Dox and 18% for BeA. More than 50% of both drugs were released within 24 h, at pH 6.8, while less drug was released at pH 7.4 in this time period. Co-incubation viability assays of Dox and BeA alone for 24 h demonstrated synergistic cytotoxic activity in the low μM range against the non-small cell lung carcinoma (NSCLC) A549 cells. Viability assays of the BSA(Dox+BeA) DDS demonstrated a higher synergistic cytotoxic activity than the two drugs with no carrier. Moreover, confocal microscopy analysis confirmed cellular internalization of the DDS and nucleus accumulation of the Dox. We determined the mechanism of action of the BSA(Dox+BeA) DDS, confirming S-phase cell cycle arrest, DNA damage, caspase cascade activation, and downregulation of the epidermal growth factor receptor (EGFR) expression. This DDS has the potential to synergistically maximize the therapeutic effect of Dox and diminish chemoresistance induced by EGFR expression using a natural triterpene against NSCLC.
ARTICLE | doi:10.20944/preprints202007.0320.v1
Subject: Medicine And Pharmacology, Oncology And Oncogenics Keywords: sarcopenia; hepatocellular carcinoma; grip strength; skeletal muscle index; lenvatinib; modified albumin-bilirubin grade
Online: 15 July 2020 (08:45:55 CEST)
Although sarcopenia is characterized by a loss of muscle strength and skeletal muscle mass, few studies have evaluated the effect of muscle strength on hepatocellular carcinoma (HCC) patients. We separately evaluated the impact of sarcopenia-related factors (grip strength [GS] and the skeletal muscle index [SMI]) on the survival among lenvatinib-treated unresectable HCC (u-HCC) patients. This single-center cohort study was conducted at a university hospital. The study population included 63 lenvatinib-treated u-HCC patients managed between April 2018 and April 2020. A decreased GS and decreased SMI were found in 21 (33.3%) and 22 (34.9%) patients, respectively. The overall survival (OS) of the normal GS group was significantly higher than that of the decreased GS group, while that of the normal and decreased SMI groups did not differ markedly. There were no significant differences in the progression-free survival between the normal GS and decreased GS groups or the normal SMI and decreased SMI groups. A multivariate Cox proportional hazards model showed that ALBI2b (hazard ratio [HR] 4.39) and a decreased GS (HR 3.55) were independently associated with an increased risk of poor prognosis. In addition to the hepatic functional reserve, a decreased GS was a poor prognostic factor in lenvatinib-treated u-HCC patients.
ARTICLE | doi:10.20944/preprints201909.0180.v1
Subject: Chemistry And Materials Science, Biomaterials Keywords: ferromagnetic fibre network; human albumin; fibrin hydrogel; human foetal osteoblasts; human endothelial cells
Online: 17 September 2019 (04:48:21 CEST)
Porous coatings on prosthetic implants encourage implant fixation. Enhanced fixation may be achieved using a magneto-active porous coating that can deform elastically in vivo on application of an external magnetic field, straining in-growing bone. Such coating, made of 444 ferritic stainless steel fibres, was previously characterised in terms of its mechanical and cellular responses. In this work, co-cultures of human osteoblasts and endothelial cells were seeded into a novel fibrin-based hydrogel embedded in a 444 ferritic stainless steel fibre network. Albumin was successfully incorporated into fibrin hydrogels improving the specific permeability and the diffusion of fluorescently-tagged dextrans without affecting their Young’s modulus. The beneficial effect of albumin was demonstrated by upregulation of osteogenic and angiogenic gene expression. Furthermore, mineralisation, extracellular matrix production and formation of vessel-like structures were enhanced in albumin-enriched fibrin hydrogels compared to fibrin hydrogels. Collectively, the results indicate that the albumin-enriched fibrin hydrogel is a promising bio-matrix for bone tissue engineering and orthopaedic applications.
ARTICLE | doi:10.20944/preprints201907.0092.v1
Subject: Medicine And Pharmacology, Dietetics And Nutrition Keywords: Type 2 diabetes; urea albumin excretion; food frequency questionnaire survey; β-cryptoxanthin; fruits
Online: 8 July 2019 (14:44:24 CEST)
Background: The dietary factors and nutrients contributing to the prevention of microalbuminuria in type 2 diabetic nephropathy is unclear, so we investigated dietary factors affecting urinary albumin excretion in patients with type 2 diabetes. Methods: 42 patients with type 2 diabetes were participated, the subjects were divided to a normal albuminuria group (urinary albumin / creatinine ratio of less than 30 mg / g Cr) and a microalbuminuria group of 30 mg / g to 299 mg / g Cr. We performed casual blood sampling and conducted a food frequency questionnaire survey. Results: There were no significant differences in age, BMI and other physiological and biochemical data, the average daily intake of energy and many of nutrients, while β-cryptoxanthin was significantly lower in the microalbuminuria group than in the normal group (506.4 ± 793.9 μg/day vs. 715.3 ± 500.3 μg/day, p <0.05). The intake of 17 food groups per day showed that the intakes of fruits were significantly lower in the microalbuminuria group than in the normal group (76.9 ± 134.1 g vs. 111.9 ± 84.5 g, p <0.05). Conclusion: These results suggest that fruits and foods rich in β-cryptoxanthin would make it possible to prevent diabetic nephropathy progression.
ARTICLE | doi:10.20944/preprints201709.0070.v1
Subject: Medicine And Pharmacology, Pharmacology And Toxicology Keywords: Coumarin; Mycobacterium tuberculosis; Cholinesterase inhibitor; Monoamine oxidase B inhibitor; Structure activity relationship; Albumin binding, Neuroprotection
Online: 15 September 2017 (17:34:38 CEST)
An in vitro medium-throughput screen using M. tuberculosis H37Rv was employed to screen an in-house library of structurally diverse compounds for antimycobacterial activity. From this initial screen, eleven 7-substituted coumarin derivatives with confirmed monoamine oxidase-B and cholinesterase inhibitory activities, demonstrated growth inhibition of more than 50% at a 50 µM concentration. This prompted further exploration of all the 7-substituted coumarins in our library, nineteen in total, as potential antimycobacterial agents. Four derivatives showed promising antimycobacterial activity with MIC99 values of 8.31 – 29.70 µM and 44.15 – 57.17 µM on M. tuberculosis H37Rv in independent assays using Gaste-Fe and 7H9 + OADC media, respectively. These compounds were found to bind to albumin which may explain the variations in MIC between the two assays. Preliminary antimycobacterial evaluation of moxifloxacin resistant M. tuberculosis show that these compounds are able to maintain their activity in fluoroquinolone resistant mycobacteria. Analysis of structure activity relationships for antimycobacterial versus neuronal enzyme inhibitory activity indicate that structural modification on position 4 and/or 7 of the coumarin scaffold may be utilized to improve selectivity towards either inhibition of neuronal enzymes or antimycobacterial effect. Cytotoxicity evaluations of the compounds indicate moderate cytotoxicity with slight selectivity towards mycobacteria. Further neuroprotective assays on SH-SY5Y human neuroblastoma cells indicate significant neuroprotection for selected compounds irrespective of their neuronal enzyme inhibitory properties. These coumarin molecules are thus interesting lead compounds that may provide insight into the design of new antimicrobacterial and/or neuroprotective agents.
ARTICLE | doi:10.20944/preprints202002.0088.v1
Subject: Chemistry And Materials Science, Analytical Chemistry Keywords: structural mass spectrometry; protein structure; chemical cross-linking; disuccinimidyl glutarate; bis(sulfosuccinimidyl) glutarate; bovine serum albumin
Online: 7 February 2020 (02:54:08 CET)
The combination of chemical cross-linking and mass spectrometry is currently a progressive technology for deriving structural information of proteins and protein complexes. In addition, chemical cross-linking is a powerful tool for stabilizing macromolecular complexes for single particle cryo-electron microscopy. Broad pallets of cross-linking chemistry, currently available for the majority of cross-linking experiments, still rely on the amine-reactive N-hydroxysuccinimide esters targeting mainly N-termini and lysine side chains. These cross-linkers are divided into two groups: water soluble and water insoluble; and research teams prefer one or another speculating on the benefits of their choice. However, the effect of cross-linker polarity on the outcome of cross-linking reaction has never been studied. Herein, we use both polar (bis(sulfosuccinimidyl) glutarate) and non-polar (disuccinimidyl glutarate) cross-linkers and systematically investigated the impact of cross-linker hydrophobicity on resulting distance constraints, using bovine serum albumin as a model protein.
REVIEW | doi:10.20944/preprints202007.0448.v1
Subject: Medicine And Pharmacology, Obstetrics And Gynaecology Keywords: C-reactive protein; hs-CRP; albumins; Glasgow Prognostic Score; Endometrial Cancer; CRP to albumin ratio; CRP; Cancer; Inflammation
Online: 19 July 2020 (21:13:19 CEST)
Endometrial Cancer (EC) is the sixth most commonly occurring cancer in women with 380 000 cases in 2018. Sadly, EC morbidity and mortality are continuously increasing, therefore the medical society have a substantial need for an accurate and inexpensive diagnostic test for EC early detection and a prognostic tool for treatment planning and evaluation. Considering experience with different types of cancers C-reactive protein (CRP) appears to be a promising diagnostic and prognostic factor. Aiming to investigate its potential and in view of EC authors, this paper reviewed the following databases for metanalysis, randomized controlled trials and review articles published up to June 2020: Pubmed, Scopus, Google scholar and ClinicalKey. Studies indicate CRP >3.33 mg/l correlate with EC incidence with HR = 2.29 (p<0.05). Moreover, High-sensitivity CRP assay allows to detect CRP in very low concentrations and distinguish patients with endometriosis, soft tissue sarcomas and possibly EC. Preoperational and postoperational CRP, as well as its dynamic change are independent prognostic factors for EC and are more reliable if analyzed together. However, CRP-to-albumin ratio as well as Glasgow Prognostic Scale have greater prognostic value that CRP alone. Additionally, CRP is possibly a mediator of carcinogenesis and cancer progression through activation of inter alia FcgRs/MAPK/ERK, FcgRs/IL-6/AKT/STAT3 and FcgRs/NF-κB/NLRP3 pathways.
ARTICLE | doi:10.20944/preprints201911.0339.v1
Subject: Chemistry And Materials Science, Medicinal Chemistry Keywords: human albumin; hydrogen bonds; hp contacts; π- π / cation-π interactions; bonds roughness; decay curve; power spectrum; interaction between amino-acids
Online: 27 November 2019 (09:35:09 CET)
In this paper we review dynamics and roughness of bonds in proteins on example of albumin, that is important from the physiological point of view. We have performed computer simulations of albumin chain. Statistics were collected by performing many simulations realizations for each experimental setting. We concentrate on hydrogen bonds, cation-π and π- π interactions and NP contacts. Histograms of hydrogen bonds length are positively skewed in contrary to histograms of interactions and HP contacts that are negatively skewed. Scaling exponents of power spectra of energies of bonds / interactions /contacts are in range -0.2 to -0.5 and significantly differ between various hydrogen bonds or interactions. Varying scaling of such spectra can be used to classify between distinct bonds or contacts. Concerning particular amino-acids, largest amount of HBO H20 bonds are between Glutamate (GLU) amino-acids and water particle, while large amount of HBO bonds are formed with Lysine (LYS). For HP contacts the mayor role plays Phenylalanine (PHE) and Leucine (LEU) amino-acids. From decay curves HBO H2O bonds decays in fastest rate, while HBO bonds and HP contacts at slowest rate. We present as well decay curves of bonds formed by particular amino-acids, that gives interesting results.
ARTICLE | doi:10.20944/preprints202105.0480.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: camptothecin; drug distribution; drug-membrane interaction; biophysical profiling; biomimetic models; partition coefficient; ADMET/PK prediction; small and wide-angle X-ray diffraction; fluorescence spectroscopy; human serum albumin (HSA)
Online: 20 May 2021 (10:52:33 CEST)
Camptothecin (CPT) is a potent anticancer drug, and its putative oral administration is envisioned although difficult due to physiological barriers that must be overcome. A comprehensive biophysical analysis of CPT interaction with biointerface models can be used to predict some pharmacokinetic issues after oral administration of this or other drugs. To that end, different models were used to mimic the phospholipid composition of normal, cancer, and blood-brain barrier endothelial cell membranes. The logD values obtained indicate that the drug is well distributed across membranes. CPT-membrane interaction studies also confirm the drug’s location at the membrane cooperative and interfacial regions. The drug can also permeate membranes at more ordered phases by altering phospholipid packing. The similar logD values obtained in membrane models mimicking cancer or normal cells imply that CPT has limited selectivity to its target. Furthermore, CPT binds strongly to serum albumin, leaving only 8.05% of free drug available to be distributed to the tissues. The strong interaction with plasma proteins, allied to the large distribution (VDSS=5.75 ± 0.932 L·Kg-1) and tendency to bioaccumulate in off-target tissues, were predicted to be pharmacokinetic issues of CPT, implying the need to develop drug delivery systems to improve its biodistribution.
ARTICLE | doi:10.20944/preprints202209.0291.v1
Subject: Biology And Life Sciences, Virology Keywords: COVID-19; Multidimensional Analysis; HCA; Hierarchical cluster analysis; regression analysis; mild; moderate; severe; Age; Score index of the chest X-ray; percentage and quantity of neutrophils; Albumin; C reactive protein; ratio of Lymphocytes
Online: 20 September 2022 (04:50:36 CEST)
INTRODUCTION: The purpose of the study was to determine (a) the overall preclinical character; (b) the cumulative cutoff values and the risk ratio, and (c) the factors associated with severity by a unidimensional and multidimensional analysis on 2173 Sars-Cov2 patients. METHODS: The machine learning study population consisted of 2173 patients (1587 mild and non symptoms patients, 377 moderate patients, 209 severe patients). The status of the patients was recorded from September 2021 to March 2022. RESULTS: The Covid19 Severity directly links with a significant correlation to Age, Score index of the chest X-ray, percentage and quantity of neutrophils, Albumin, C reactive protein, and ratio of Lymphocytes. Their important cut off values (from regression analysis) respectively are: 77.56 years old (the mild-moderate group), 5.53 (the mild-moderate group) and 10.51 (the moderate-severe group), 84.80% (the mild-moderate group) and 87.74%(the moderate-severe group), 11.77G/L (the moderate-severe group), 29.73g/L (the moderate-severe group), 7.46mg/dL (the mild-moderate group), 6.32% (the moderate-severe group). Their significant (p<0.0001) R score correlation with the severity of Covid19, are: 0.44, 0.52 and 0.52, 0.33 and 0.44, 0.42, -0.43, 0.40, -0.41. Their significant risk ratio (p<0.00001) from the meta-analysis, respectively are: 4.19 [3.58-4.95], 3.29 [2.76-3.92] and 3.03 [2.4023;3.8314], 3.18 [2.73-3.70] and 3.32 [2.6480;4.1529], 3.15 [2.6153;3.8025], 3.4[2.91-3.97], 0.46 [0.3650;0.5752] (p<0.00001), 0.34 [0.2743;0.4210]. The pair ALT – Leucocytes and Transferrin – Anion Chloride get the most important correlation shift. ALT – Leucocytes show the important negative link (R=-1, p<0.00001) in the mild group to the significant positive correlation in the moderate group (R=1, p<0.00001). Transferrin–anion Chloride has an important positive association (R=1, p<0.00001) in the mild group with a significant negative correlation in the moderate group (R=-0.59, p<0.00001). The network map and HCA show that in the mild-moderate group, the closest neighbors with the Covid19 severity are ferritins, Age. Then there is C-reactive protein, SI of X-ray, Albumin, and Lactate dehydrogenase, which are the next close neighbors of these three factors. In the moderate-severe group, the closest neighbors with the Covid19 severity are Ferritin, Fibrinogen, Albumin, the quantity of Lymphocytes, SI of X-ray, white blood cells count, Lactate dehydrogenase, and quantity of neutrophils. CONCLUSIONS: Complete multidimensional study in 2173 Covid19 patients in Vietnam shows the whole picture of all the preclinical factors, which may become the clinical reference marker for surveillance and diagnostic management