Platelet functions in lymphatic filariasis patients.

Filariasis is a chronic disease where parasitic worms survive in human hosts even for decades and lead to complications like lymphedema and elephantiasis. Despite the persistent existence of filarial parasites in human hosts, fatal and thrombotic complications are not known, unlike other parasitic diseases like malaria. This suggests that filarial parasites might be affecting the host's platelet functions. This study was conducted to examine platelet functions in confirmed filariasis patients and healthy controls. Results showed that filariasis patients had larger platelets, inhibited aggregation, and slower speed of aggregation, compared to controls. However, in vivo markers of platelet activation and degranulation (beta thromboglobulin and soluble P-selectin) were not affected. Observations suggested that there is increased platelet turnover, cellular apoptosis and inhibited platelet functions in filariasis patients compared to controls. Platelet function inhibition was not associated with the duration of disease, lymphedema-affected organs, or gender of patients. This study confirms that filarial parasites modulate platelet functions in human hosts.

CTLA4 Gene Polymorphism and its Association with Disease Occurrence, Clinical Manifestations, Serum Markers and Cytokine Levels in SLE Patients from North India.

Background: Cytotoxic T lymphocyte-associated protein-4 (CTLA-4) or CD152 is an inhibitory receptor expressed constitutively on CD4+CD25+ T regulatory lymphocytes (Treg) and transiently on activated CD4+ and CD8+ T lymphocytes. Association of CTLA4 gene polymorphisms with Systemic Lupus Erythematosus (SLE) has been reported in south Indians, but not in north Indians. This study aims to investigate CTLA4 gene polymorphism and its association with the occurrence of SLE, its clinical manifestation and serological markers in north Indians. Methods: This cross sectional study was done in a tertiary health care centre in north India. Patients reporting to the hospital and diagnosed with systemic lupus erythematosus were included in study. +49 A/G (snp- rs231775) CTLA4 gene polymorphism was analysed in 41 SLE patients and 21 matched healthy controls by real time PCR method. ANA (Antinuclear Antibody), anti dsDNA, Interferon-γ (IFN- γ), TGF-ß, IL-10 were measured by ELISA kits. Complement (C3 and C4) and immunoglobulins (IgA, IgG, IgM) estimation were done with the turbidometry method. Chi-square test was used for comparison between groups and odds ratio with 95% confidence interval was calculated to estimate the associated risk. Results: A/A genotype was most common (51.2%) followed by the A/G genotype (46.3%) and G/G genotype (2.4%, detected in only 1 patient). The frequency of A allele was 74.4%, while of G allele was only 25.6%. A/G genotype SLE patients showed a higher risk (odds ratio 37.5, 95% CI- 6.048-232.51) of developing edema compared to A/A genotype patients. There was no statistically significant association of various CTLA4 genotypes with the occurrence of SLE and serum markers. Conclusions: A/A was the most common CTLA4 genotype in both SLE patients and healthy controls of north India. Contrary to the previous report in south Indians, there was no statistically significant association between CTLA4 genotype and occurrence of SLE in north Indians. Only the presence of generalised edema was found significantly associated with the A/G genotype.

Fibrinogen Mitigates Prion-Mediated Platelet Activation and Neuronal Cell Toxicity.

Prion peptide (PrP) misfolds to infectious scrapie isoform, the ß pleat-rich insoluble fibrils responsible for neurodegeneration and fatal conformational diseases in humans. The amino acid sequence 106-126 from prion proteins, PrP(106-126), is highly amyloidogenic and implicated in prion-induced pathologies. Here, we report a novel interaction between PrP(106-126) and the thrombogenic plasma protein fibrinogen that can lead to mitigation of prion-mediated pro-thrombotic responses in human platelets as well as significant decline in neuronal toxicity. Thus, prior exposure to fibrinogen-restrained PrP-induced rise in cytosolic calcium, calpain activation, and shedding of extracellular vesicles in platelets while it, too, averted cytotoxicity of neuronal cells triggered by prion peptide. Interestingly, PrP was found to accelerate fibrin-rich clot formation, which was resistant to plasmin-mediated fibrinolysis, consistent with enhanced thrombus stability provoked by PrP. We propose that PrP-fibrinogen interaction can be clinically exploited further for prevention and management of infectious prion related disorders. Small molecules or peptides mimicking PrP-binding sites on fibrinogen can potentially mitigate PrP-induced cellular toxicity while also preventing the negative impact of PrP on fibrin clot formation and lysis.

Effects of Nanoceria on Human Platelet Functions and Blood Coagulation.

PURPOSE: Cerium oxide nanoparticles (nanoceria) exist in either 3+ or 4+ oxidation state with interesting redox properties and exhibit both oxidant and antioxidant attributes based on concentration, environment and pH. Thanks to their wide spread use in fuel, cosmetics and other industries as well as in biomedical field, nanoceria particles get released into environment with risk of significant human exposure, and thus necessitate careful examination and optimization of their biomedical applications. METHODS: This research was planned to explore effects of nanoceria on human platelet functions and whole blood coagulation. Platelets and whole blood from volunteer healthy donors were treated with different doses of nanoceria and various platelet functions, fibrin polymerization and blood coagulation were tested. RESULTS: Nanoceria particles were found to reduce platelet aggregation and secretion of granule contents in a dose-dependent manner, impaired fibrin polymerization and retraction of fibrin-rich thrombi, associated with reduced cytosolic filamentous actin. Remarkably, nanoceria instigated early clot formation in whole blood attributable to putative activation of coagulation cascade. CONCLUSION: Above observations provide cautionary framework to critically re-evaluate and accordingly plan biomedical applications of nanoceria.

Engineered human platelet-derived microparticles as natural vectors for targeted drug delivery.

Drug targeting has opened a new paradigm in therapeutics with development of delivery vectors like liposomes and polymeric nanoparticles. Although their clinical application is crippled by limited biological adaptability. Off-target toxicity and biocompatibility still remains one of the critical problems in anticancer therapeutics that can be life-threatening. Here we report a quick, simple and facile method of engineering human platelets to generate drug loaded platelet-derived microparticles (PMPs) by top-down approach, which are biocompatible and naturally target leukemia cells. Drug loaded PMPs and cancer cell uptake were characterized by flow cytometry, confocal microscopy, Nanoparticle Tracking Analysis and fluorimetry. Effective drug delivery was tested in cancer cell lines as well as in clinical samples from leukemia patients. We explored that PMPs are capable of carrying multiple drug payloads, have long shelf life and can be harvested in large quantity in short period. Importantly, PMPs exhibited remarkably higher toxicity towards cancer cells than free drug and had lower escape into extravascular spaces. Transfer of drug to cancer cells of leukemia patients was significantly higher than free drug, when delivered through PMPs. Our experiments validated therapeutic application of PMPs as biocompatible drug delivery vector against cancer cells with minimal off-target delivery.

Role of CTLA4 A49G polymorphism in systemic lupus erythematosus and its geographical distribution.

CTLA-4 (cytotoxic T-lymphocyte-associated protein-4) or CD152 is an inhibitory receptor expressed constitutively on CD4+ CD25+ T regulatory lymphocytes and transiently on activated CD4+ and CD8+ T lymphocytes. Its inhibitory function promotes long-lived anergy in immune cells and prevents autoimmunity. Therefore, it plays a crucial role in T cell-mediated autoimmunity, and thus in susceptibility to autoimmune diseases, including systemic lupus erythematosus (SLE). It is encoded by CTLA4 gene in humans. AtoG polymorphism at position +49 of CTLA4 gene is the only polymorphism which changes amino acid sequence from alanine to threonine in the leader sequence, which may affect the function of CTLA-4. Association of CTLA4 polymorphisms with SLE has been investigated in several reports in different ethnic populations from different countries, which have shown highly inconsistent findings. In this review, we have compiled previous studies which have reported the association of CTLA4 A49G polymorphism in SLE and its geographical distribution.

Regulatory T Cells and Their Association with Serum Markers and Symptoms in Systemic Lupus Erythematosus and Rheumatoid Arthritis.

PURPOSE: Impairment in number and functions of regulatory T cells (Treg) has been found to be associated with many autoimmune diseases including systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA). This study was conducted to identify and compare Treg by flow cytometry using two different staining approaches. METHODS: Treg were identified by using CD4+CD25+high and CD4+CD25+CD127dim staining approaches in SLE and RA patients and healthy controls. Association of both identified Treg levels with various serum markers and clinical presentation was also examined. RESULTS: Blood CD4+CD25+CD127dim cells levels were 11.4+3.57 %, 9.76+2.37 % and 6.95+1.16 %; while CD4+CD25+high cells were 1.46+1.09 %, 0.95+0.59 % and 1.87+1.14 % in SLE patients, RA patients and healthy controls respectively. Number of CD4+CD25+CD127dim cells was higher than CD4+CD25+high cells in blood samples of all three study groups. Levels of CD4+CD25+CD127dim cells were significantly higher in SLE and RA patients, compared to healthy controls, but this difference was not observed for CD4+CD25+high Treg. CD4+CD25+high levels showed significant correlation with serum C4, IFN-γ and IL-10 levels in healthy subjects and with C4 levels and fever in SLE patients. CD4+CD25+CD127dim levels showed significant association with alopecia and oral ulcers in SLE patients only, but no correlation with measured serum markers. CONCLUSION: Results suggest that both staining approaches detect Treg differently and also that Treg play different role in pathogenesis of SLE and RA.

Platelet-derived microparticles analysis: Techniques, challenges and recommendations.

Platelet-derived microparticles (PMP) are nano size fragments (100-1000 nm) released from platelets under various physiological and pathological conditions. PMP are the most abundant microparticles present in human blood. In recent past years PMP have caught attention of many clinicians as well as researchers for being associated with many diseases like cardio-vascular diseases, infections etc; and have emerged as potential biomarkers. Owing to their small size and diverse phenotype, structure and functions, microparticles including PMP render many challenges during sample handling, estimation and characterization. PMP can be analyzed for many parameters like absolute count, size distribution, functions, content, surface proteins and other phenotypic characteristics. Many techniques have been invented to analyze PMP and other extracellular vesicles for these parameters, but none of them is capable of examining all parameters alone. Apart from it, every technique has its own advantages, limitations and sets of recommendations while using it. This often leads to applying multiple techniques in combination for accurately measuring various parameters and user has to decide cautiously which technique has to be used for their selected parameter testing. This review compiles various methods, techniques, challenges during PMP analysis and recommendations based on previous studies, aimed at guiding users for selecting the most suitable techniques for their experiments with PMP.

Effects of 6-Week Sprint-Strength and Agility Training on Body Composition, Cardiovascular, and Physiological Parameters of Male Field Hockey Players.

Sharma, HB and Kailashiya, J. Effects of 6-week sprint-strength and agility training on body composition, cardiovascular, and physiological parameters of male field hockey players. J Strength Cond Res 32(4): 894-901, 2018-Optimal physiological and cardiovascular characteristics are essential for optimal physical performance. Different types of training regimes affect these characteristics and lead to trainees' adaptation and changes in relevant parameters. In the present interventional study, we have evaluated the effects of 6-week sprint-strength and agility training on such parameters. Twenty-four young Indian national hockey players volunteered for this study. Body weight (BW), body mass index (BMI), percentage body fat, lean body mass (LBM), resting heart rate (rHR), resting blood pressure (rBP), resting double-product (rDP), P/power (using Running-based Anaerobic Sprint Test), vertical jump (VJ), seated shot put test (SP), ball-hitting speed (BS), Tm (505-agility test), and V[Combining Dot Above]O2max were measured, and changes (d) after specified training regime were studied. The training proved to be "short yet effective." Significant improvements after training were found in body composition, cardiovascular, aerobic, anaerobic, strength, agility, and performance-related parameters; but not in BW, BMI, P/LBM, SP/LBM, and V[Combining Dot Above]O2max/LBM. Change in VJ (dVJ) was associated with change in Tm (dTm); change in SP (dSP) with change in VO2max, which also related to change in rHR, rBP and rDP. Change in BS (dBS) was more among those with lower initial BW, BMI, and BF. dBS, along with change in VO2max/LBM, was more mainly among those with lower initial anaerobic-aerobic fitness. The findings will be useful for coaches, sports managers, players, and also for general population for better, individual, and sport-based designing of "short yet effective" training programs and monitoring of outcomes. Specific physiological parameter improvement-targeted training can also be designed based on this research.

Telomerase based anticancer immunotherapy and vaccines approaches.

Telomerase is a Reverse Transcriptase that maintains the telomere length. It is absent in most somatic cells but is found in stem cells, germ cells and around 90% of cancers. It plays a crucial role in developing and maintaining cancer cells. Telomerase, a HLA class-I antigen, is able to stimulate cell mediated immune response by inducing cytotoxic T-cells. This property of telomerase is being exploited in targeting cancers by host's own immune responses; stimulated by various Human Telomerase Reverse Transcriptase (hTERT) derived vaccines. Many approaches and studies including clinical trials have shown effective anticancer responses of these vaccines, without toxicity to non cancer cells. In this article we have compiled different hTERT based anticancer immunotherapy approaches, vaccines and their performances.

The Anthropometric Correlates for the Physiological Demand of Strength and Flexibility: A study in Young Indian Field Hockey Players.

INTRODUCTION: Optimal strength and flexibility are essential for performance enhancement and injury prevention in hockey, and anthropometry is known to influence these parameters. AIM: To find anthropometric correlates for strength and flexibility score in young Indian field hockey players. MATERIALS AND METHODS: Thirteen female and 19 male subjects volunteered for the study. Selected anthropometric variables: lengths, breadths, girths and body composition; strength and sit and reach score were measured for each subject. RESULTS: Males were taller, leaner and stronger with longer upper limbs and broader chests. With few exceptions, taller, heavier and leaner players with longer trunks and limbs, broader chest and hip, and bulkier arms and lower limbs had stronger grip, back, upper and lower limbs. Heavier and taller players with longer trunk and more percentage of body fat were more flexible. Also, the stronger players had more percentage body fat and body mass index, which might be due to the strong positive correlation of percentage body fat and body mass index with fat free mass. CONCLUSION: Anthropometric variables, especially heights, breadths and body composition, show significant correlation with strength and flexibility, and hence may serve as monitoring tool and for talent identification.

Gender Difference in Aerobic Capacity and the Contribution by Body Composition and Haemoglobin Concentration: A Study in Young Indian National Hockey Players.

INTRODUCTION: Although gender difference in aerobic capacity is known, the contributing factors have been researched seldom. AIM: To investigate the gender gap and the contribution by percentage Body Fat (BF), Body Mass Index (BMI) and haemoglobin concentration Hb. MATERIALS AND METHODS: The study was conducted on 30 (17 males, 13 females) training status matched young hockey players. Healthy players who were playing upto national level competition were included. BW (Body Weight), BF, BMI, LBM (Lean Body Mass), rHR (restring Heart Rate), HRR (Heart Rate Recovery), Hb, a/rVO2max (absolute/relative), a/rPWC (Physical Work Capacity) and RMR (Resting Metabolic Rate) were measured and analysed. RESULTS: There was significant gender difference in the measured parameters. Difference in a/rVO2max remained significant even after controlling for BF, BMI and Hb. Multiple regression and correlation analysis revealed gender difference in VO2max/LBM was due to: BMI(31.91%)>BF(27.60%)>Hb(9.91%). BMI also significantly contributed 3.66% of VO2max/LBM variance, independent of that by gender. Difference in RMR was mainly related to LBM, BF and BMI. CONCLUSION: The study provided an understanding for gender gap in aerobic capacity. Differences in BMI & BF were one of the main reasons.

Gender Difference in Fatigue Index and its Related Physiology.

Fatigue index exhibits gender difference. This study was carried out to compare fatigue index of young, national level male and female field hockey players; and to explore physiological variables contributing to this difference. We measured running-based anaerobic sprint fatigue index and selected physiological parameters in male and female players matched for age, duration of training, diet, habitual physical activity, body weight and BMI. The male hockey players showed lower resistance to repeated sprints fatigue than the female players. Body weight, BMI and power variables positively correlated to fatigue index in both sexes; while lean body mass and age in males only, and body fat % in females only were found to be correlated to fatigue index. Difference in lean body mass, body fat %, strength and anaerobic power might be responsible for gender difference in intermittent & repeated sprints fatigue index observed in studied players.

Graphene oxide-based biosensor for detection of platelet-derived microparticles: A potential tool for thrombus risk identification.

We report here design of a graphene oxide-based electrochemical biosensor for detection of platelet-derived microparticles (PMPs), a major risk factor for arterial pro-thrombotic pathologies like acute myocardial infarction and stroke. Electrodes were fabricated with immobilized layers of graphene oxide and a specific antibody targeted against active conformation of integrin αIIbß3 on PMP surface. Results showed progressive rise in impedance in Nyquist plots with increasing number of PMPs in analyte. The sensor was highly specific for PMPs and did not identify microparticles originating from other cells. Blood obtained from patients diagnosed with acute myocardial infarction exhibited significantly higher values of impedance, consistent with larger number of circulating PMPs in these patients, as compared to samples from healthy individuals, thus validating biosensor as a specific, sensitive, label-free and cost-effective tool for rapid point-of-care detection of PMPs at bedside. Our biosensor is most ideal for mass population screening programs at periphery-level healthcare units with limited resources. It is aimed at early detection of individuals having higher imminent cardiovascular risk, as well as for routine analysis, which in turn would contribute to better management and survival of screened 'high-risk' subjects.

Sitagliptin: anti-platelet effect in diabetes and healthy volunteers.

Sitagliptin, a selective dipeptidyl peptidase-4 inhibitor drug is used to treat type-2 diabetes (T2DM). We investigated the anti-platelet activity of sitagliptin in patients with T2DM and in in vitro samples obtained from healthy humans. Patients with T2DM (27 male + 23 female) were selected and followed up before (control) and after treatment with sitagliptin for up to 3 months. Platelets were isolated from the blood of sitagliptin treated patients and controls. Patients with T2DM treated with sitagliptin for 1and 3 months, showed 10 ± 2% and 30 ± 5% inhibition of platelet aggregation, respectively. For the in vitro study, platelets from 10 normal humans (n = 10) were isolated. Platelet aggregation, intracellular free calcium and tyrosine phosphorylation of multiple proteins were measured by aggregometer, spectrofluorometer and western blotting, respectively. Platelets pre-treated with 5 and 10 µg/ml of sitagliptin, showed 25 ± 4% and 40 ± 6% inhibition of thrombin-induced platelet aggregation, respectively. Sitagliptin decreased intracellular free calcium (2.5-fold) and tyrosine phosphorylation of multiple proteins in thrombin-induced platelet activation. Sitagliptin inhibited platelet aggregation in T2DM as well as in healthy humans. Sitagliptin has significant concentration-dependent anti-platelet activity. This activity was due to its inhibitory effect on intracellular free calcium and tyrosine phosphorylation.