xygen-compromised environments, such as high altitude, are associated with platelet hyperactivity. Platelets confined within the relatively impervious core of an aggregate/thrombus have restricted access to oxygen, yet they continue to perform energy-intensive procoagulant activities that sustain the thrombus. Studying platelet signaling under hypoxia is, therefore, critical to our understanding of the mechanistic basis of thrombus stability. We report here that hypoxia-inducible factor (HIF)-2a is translated from pre-existing mRNA and stabilized against proteolytic degradation in enucleate platelets exposed to hypoxia. Hypoxic stress, too, stimulates platelets to synthesize plasminogen-activator inhibitor-1 (PAI-1) and shed extracellular vesicles, both of which potentially contribute to the prothrombotic phenotype associated with hypoxia. Stabilization of HIF-a by administering hypoxia-mimetics to mice accelerates thrombus formation in mesenteric arterioles. In agreement, platelets from patients with chronic obstructive pulmonary disease and high altitude residents exhibiting thrombogenic attributes have abundant expression of HIF-2a and PAI-1. Thus, targeting platelet hypoxia signaling could be an effective antithrombotic strategy.

No abstract

Background:The role of sirtuins in regulating platelet aging is largely unexplored. Results: Sirtuin inhibitors induced apoptosis-like changes in blood platelets, associated with a rise in active Bax and a significant drop in platelet count. Conclusion: Sirtuins act as a central player in the determination of platelet aging. Significance: This study refocuses attention on the potential side effect of sirtuin inhibition in delimiting platelet life span and management of thrombosis.

Introduction: Dyslipidemia is highly prevalent among type 2 diabetic patients. It increases the risk of atherosclerosis and consequent mortality in diabetic patients. The aim of this study was to find out the prevalence of dyslipidemia among type 2 diabetic patients. Methods: This was a descriptive cross-sectional study in 355 type 2 diabetic patients at tertiary care hospital from 15th May, 2020 to 15th November, 2020 after taking ethical clearence from Institutional Review Committee (Reference no. IRC-PA-052/2077-78). Convenience sampling was done. Demographic and lipid profile variables were recorded based on the structured questionnaires. Data were analyzed by Statistical Package for the Social Sciences version 20. Point estimate at 95% Confidence Interval was calculated along with frequency and percentage for binary data. Results: Out of total 355 cases of type 2 Diabetes mellitus, prevalence of dyslipidemia was 224 (63.1%). It was more prevalent in male 145 (69.4%) than female 79 (54.1%). Increased Low density Lipoprotein (94.2%) was the most prevalent type followed by mixed dyslipidemia (91.1%). Conclusions: Dyslipidemia was common among type 2 diabetic patients and was higher in male gender, older age, obesity and longer duration of diabetes. Hence type 2 diabetic patient should undergo the routine monitoring of blood sugar and lipid profile so that any abnormalities can be identified and preventive measures along with interventions can be initiated at the earliest.

Background: Notch signaling dictates cell fate decisions in mammalian cells including megakaryocytes. Existence of functional Notch signaling in enucleate platelets remains elusive. Methods: Transcripts/peptides of Notch1 and Delta-like ligand (DLL)-4 were detected in platelets isolated from human blood by RT-qPCR, Western analysis and flow cytometry. Platelet aggregation, granule secretion and platelet-leucocyte interaction were analyzed by lumi-aggregometry and flow cytometry. Platelet-derived extracellular vesicles were documented with Nanoparticle Tracking Analyzer. Platelet thrombus on immobilized collagen was quantified using microfluidics platform. Intracellular calcium was monitored by fluorescence spectrophotometry. Whole blood coagulation was studied by thromboelastography. Ferric chloride-induced mouse mesenteric arteriolar thrombosis was imaged by intravital microscopy. Results: We demonstrate expression of Notch1, its ligand DLL-4 and their respective transcripts in human platelets. Synthesis and surface translocation of Notch1 and DLL-4 were upregulated by thrombin. DLL-4, in turn, instigated neighbouring platelets to switch to 'activated' phenotype through cleavage of Notch receptor and release of its intracellular domain (NICD), which was averted by inhibition of γ-secretase and phosphatidylinositol-3-kinase (PI3K). Inhibition of Notch signaling, too, restrained agonist-induced platelet activation, and significantly impaired arterial thrombosis in mice. Strikingly, prevention of DLL-4-Notch1 interaction by a blocking antibody abolished platelet aggregation and extracellular vesicle shedding induced by thrombin. Conclusions: Our study presents compelling evidence in support of non-canonical juxtacrine Notch signaling within platelet aggregates that synergizes with physiological agonists to generate occlusive intramural thrombi. Thus, Notch pathway can be a potential anti-platelet/anti-thrombotic therapeutic target. Funding: Research was supported by grants received by DD from JC Bose Fellowship (JCB/2017/000029), ICMR (71/4/2018-BMS/CAR), DBT (BT/PR-20645/BRB/10/1541/2016) and SERB (EMR/2015/000583). SNC, ME and VS are recipients of ICMR-Scientist-C, CSIR-SRF and UGC-SRF support, respectively. Funders had no role in design, analysis and reporting of study.

Background: Notch signaling is an evolutionarily conserved pathway that dictates cell fate decisions in mammalian cells including megakaryocytes. Existence of functional Notch signaling in enucleate platelets that are generated as cytoplasmic buds from megakaryocytes still remains elusive. Methods: Platelets were isolated from human blood by differential centrifugation under informed consent. Expression of transcripts as well as peptides of Notch1 and DLL-4 in platelets was studied by employing RT-qPCR, Western analysis and flow cytometry. Platelet activation responses that include aggregation, secretion of granule contents and platelet-leucocyte interaction were analyzed by Born's aggregometry, flow cytometry, Western analysis and lumi-aggregometry. Shedding of extracellular vesicles from platelets was documented with Nanoparticle Tracking Analyzer. Platelet adhesion and thrombus growth on immobilized matrix was quantified by employing microfluidics platform. Intracellular free calcium in Fura-2-loaded platelets was monitored from ratiometric fluorescence spectrophotometry. Coagulation parameters in whole blood were studied by thromboelastography. Ferric chloride-induced mesenteric arteriolar thrombosis in murine model was imaged by intravital microscopy. Results: Here we demonstrate significant expression of Notch1 and its ligand, the Delta-like ligand (DLL)-4, as well as their respective transcripts, in human platelets. Synthesis and surface translocation of Notch1 and DLL-4 were upregulated when cells were challenged with physiological agonists like thrombin. DLL-4, in turn, instigated neighbouring platelets to switch to 'activated' phenotype, associated with cleavage of Notch receptor and generation of its intracellular domain (NICD). DLL-4-mediated pro-thrombotic attributes were averted by pharmacological inhibition of γ-secretase and phosphatidylinositol 3-kinase. Inhibition of Notch signaling, too, restrained agonist-induced platelet activation, and significantly impaired arterial thrombosis in mice, suggestive of synergism between thrombin- and DLL-4-mediated pathways. Strikingly, prevention of DLL-4-Notch1 interaction by a blocking antibody abolished platelet aggregation and extracellular vesicle shedding induced by thrombin. Conclusions: Our study presents compelling evidence in support of non-canonical Notch signaling that propagates in juxtacrine manner within platelet aggregates and synergizes with physiological agonists to generate occlusive intramural thrombi. Thus, targeting Notch signaling can be investigated as a potential anti-platelet/anti-thrombotic therapeutic approach. Funding: This research was supported by J. C. Bose National Fellowship (JCB/2017/000029) and grants received by D. Dash from the Indian Council of Medical Research (ICMR) under CAR (71/4/2018-BMS/CAR), Department of Biotechnology (DBT) (BT/PR-20645/BRB/10/1541/2016) and Science and Engineering Research Board (SERB) (EMR/2015/000583), Government of India. S.N. Chaurasia is a recipient of financial assistance from the ICMR. M. Ekhlak is a recipient of CSIR-SRF and V. Singh is a recipient of UGC-SRF. D. Dash acknowledges assistance from the Humboldt Foundation, Germany. Funders have no role in the design, analysis and reporting of the study.

Background: TSH and circulating thyroid hormones are measured in serum as part of a thyroid function test (TFT), which evaluates the thyroid gland's ability to produce and regulate thyroid hormones. The objective of the current study was to compare the technical performance between ELISA, FEIA and the currently marketed automated CLIA for measuring the TSH level. Material and methods: A total of 1,200 participants were enrolled in the study. Subjects were chosen randomly, either OPD patients or inpatients of Birat Medical College Teaching Hospital. Chemiluminescence Immunoassay (CLIA), Enzyme-linked Immunoassay (ELISA) and Fluorometric Enzyme Immunoassay (FEIA) technologies were performed. Results: The total number of patients (1200) was categorized into group I, normal TSH (n = 680); group II, elevated TSH (n = 300); and group III, decreased TSH (n = 220). CLIA and FEIA based results were significantly more sensitive compared to ELISA results for TSH detection. Conclusion: Chemiluminescence assay system, when compared to FEIA and ELISA, is far superior in terms of accuracy and sensitivity for reporting both subnormal and above normal TSH levels and can be helpful in the detection of subclinical thyroid dysfunction (SCTD) and in the screening of thyroid diseases.

Introduction: Thyroid hormones control growth, development and metabolic processes. Either excessive or deficient secretion of these hormones interfere with metabolism. Thyroid hormones, therefore, can alter a person's blood sugar. Relatively, thyroid peroxidise enzyme plays a key role in thyroid hormone production. The individuals who suffer from autoimmune thyroid diseases produce auto antibodies against thyroid peroxidise (called anti-TPO). Objectives: We aimed to investigate an association of anti-TPO titer among type-2 diabetic patients suffering from thyroid disorders attending the local hospital. Methodology: Based on findings of thyroid variables [such as total triiodothyronine (TT3 ), thyroxine (T4 ) and thyroid stimulated  hormone (TSH)], type-2 diabetic patients were categorized into Euthyroidism, Subclinical hypothyroidism and Hypothyroidism. In this hospital-based prospective study, venipuncture was performed to collect anti-cubital venous blood samples (n=100) from January to December, 2018. After separation of sera, estimation of certain parameters such as TT3, T4 , TSH and anti-TPO were carried out for correlative analyses. In this aspect, based on WHO guidelines, the patients who had fasting as well as postprandial blood sugar levels > 126 and 200 mg/dl were confirmed for diabetes mellitus. In addition, if these patients exhibited HbA1C levels > 10.8 %, they were enrolled into the 1 study. The patients who were hyperglycemic (with fasting as well as post-prandial blood sugar levels < 126 and 200 mg/dl) were excluded. Results: In the three groups as stated above, we observed that more a rise in level of glucose, greater were the values of TSH and anti-TPO. Conclusion Such findings emphasize and put an impact in situations of thyroid abnormality among type-2 local diabetic population.