Medical College and Hospital, Kolkata

About: Medical College and Hospital, Kolkata is a education organization based out in Kolkata, West Bengal, India. It is known for research contribution in the topics: Population & Outpatient clinic. The organization has 1835 authors who have published 1801 publications receiving 12941 citations. The organization is also known as: Kolkata Medical College & Calcutta Medical College.

Protective role of magnesium in cardiovascular diseases: a review.

Abstract: A considerable number of experimental, epidemiological and clinical studies are now available which point to an important role of Mg2+ in the etiology of cardiovascular pathology. In human subjects, hypomagnesemia is often associated with an imbalance of electrolytes such as Na+, K+ and Ca2+. Abnormal dietary deficiency of Mg2+ as well as abnormalities in Mg2+ metabolism play important roles in different types of heart diseases such as ischemic heart disease, congestive heart failure, sudden cardiac death, atheroscelerosis, a number of cardiac arrhythmias and ventricular complications in diabetes mellitus. Mg2+ deficiency results in progressive vasoconstriction of the coronary vessels leading to a marked reduction in oxygen and nutrient delivery to the cardiac myocytes. Numerous experimental and clinical data have suggested that Mg2+ deficiency can induce elevation of intracellular Ca2+ concentrations, formation of oxygen radicals, proinflammatory agents and growth factors and changes in membrane permeability and transport processes in cardiac cells. The opposing effects of Mg2+ and Ca2+ on myocardial contractility may be due to the competition between Mg2+ and Ca2+ for the same binding sites on key myocardial contractile proteins such as troponin C, myosin and actin. Stimulants, for example, catecholamines can evoke marked Mg2+ efflux which appears to be associated with a concomitant increase in the force of contraction of the heart. It has been suggested that Mg2+ efflux may be linked to the Ca2+ signalling pathway. Depletion of Mg2+ by alcohol in cardiac cells causes an increase in intracellular Ca2+, leading to coronary artery vasospasm, arrhythmias, ischemic damage and cardiac failure. Hypomagnesemia is commonly associated with hypokalemia and occurs in patients with hypertension or myocardial infarction as well as in chronic alcoholism. The inability of the senescent myocardium to respond to ischemic stress could be due to several reasons. Mg2+ supplemented K+ cardioplegia modulates Ca2+ accumulation and is directly involved in the mechanisms leading to enhanced post ischemic functional recovery in the aged myocardium following ischemia. While many of these mechanisms remain controversial and in some cases speculative, the beneficial effects related to consequences of Mg2+ supplementation are apparent. Further research are needed for the incorporation of these findings toward the development of novel myocardial protective role of Mg2+ to reduce morbidity and mortality of patients suffering from a variety of cardiac diseases.

Ascorbic acid metabolism in diabetes mellitus

Abstract: In contrast to normal subjects diabetic patients and very low plasma ascorbic acid and significantly high (p less than 0.001) dehydroascorbic acid irrespective of age, sex, duration of the disease, type of treatment, and glycemic control. However, there was no significant difference between the mean leukocyte ascorbate concentrations of the two populations. The in vitro rates of dehydroascorbate reduction in the hemolysate and the erythrocyte reduced glutathione levels and the glucose-6-phosphate dehydrogenase activities, which regulate the dehydroascorbate reduction, were similar in normal and diabetic subjects. The turnover of ascorbic acid was higher in the diabetics than that in the normal volunteers. Experiments with diabetic rats indicated that the increased turnover of ascorbic acid was probably due to increased oxidation of ascorbate to dehydroascorbate in tissue mitochondria. Ascorbic acid supplementation at a dose of 500 mg per day for a brief period of 15 days resulted in an increase in the plasma ascorbate level temporarily, but it did not lower the blood glucose level of the diabetic patients.

Immune Thrombocytopenia Secondary to COVID-19: a Systematic Review.

Abstract: Immune thrombocytopenia, often known as immune thrombocytopenic purpura (ITP), has emerged as an important complication of COVID-19. A systematic review was done to analyze the clinical profile and outcomes in a total of 45 cases of new-onset ITP in COVID-19 patients described in literature until date. A comprehensive approach is essential for diagnosing COVID-19-associated ITP after excluding several concomitant factors that can cause thrombocytopenia in COVID-19. Majority of ITP cases (71%) were found to be elderly (> 50 years) and 75% cases had moderate-to-severe COVID-19. Three patients (7%) were in the pediatric age group. Reports of ITP in asymptomatic COVID-19 patients (7%) underscore the need for COVID-19 testing in newly diagnosed patients with ITP irrespective of COVID-19 symptoms amid this pandemic. ITP onset occurred in 20% cases 3 weeks after onset of COVID-19 symptoms, with many reports after clinical recovery. SARS-CoV-2-mediated immune thrombocytopenia can be attributed to the underlying immune dysregulation, susceptibility mutations in SOCS 1, and other mechanisms, including molecular mimicry, cryptic antigen expression, and epitope spreading. No bleeding manifestations were reported in 31% cases at diagnosis. Severe life-threatening bleeding was uncommon. One case of mortality was attributed to intracranial hemorrhage. Secondary Evans syndrome was diagnosed in one case. Good initial response to short course of glucocorticoids and intravenous immunoglobulin has been found with the exception of delayed lag response in one case. Thrombopoietin receptor agonist usage as a second-line agent has been noted in few cases for short duration with no adverse events. In the relatively short follow-up period, four relapses of ITP were found.

Hospital-based perinatal outcomes and complications in teenage pregnancy in India.

Abstract: Teenage pregnancy is a worldwide problem bearing serious social and medical implications relating to maternal and child health. A cross-sectional observational study was undertaken to compare the different sociodemographic characteristics and perinatal outcomes of teenage primigravida mothers with those of adult primigravida mothers in a tertiary-care hospital in eastern India. A sample of 350 each in cases and comparison group comprised the study subjects. Data were collected through interviews and by observations using a pretested and predesigned schedule. Results revealed that the teenage mothers had a higher proportion (27.7%) of preterm deliveries compared to 13.1% in the adult mothers and had low-birthweight babies (38.9% vs 30.4% respectively). Stillbirth rate was also significantly higher in teenage deliveries (5.1% vs 0.9% respectively). The teenage mothers developed more adverse perinatal complications, such as preterm births, stillbirths, neonatal deaths, and delivered low-birthweight babies, when compared with those of the adult primigravida mothers. Teenage pregnancy is still a rampant and important public-health problem in India with unfavourable perinatal outcomes and needs to be tackled on a priority basis.

Deregulation and cross talk among Sonic hedgehog, Wnt, Hox and Notch signaling in chronic myeloid leukemia progression.

Abstract: Deciphering the BCR-ABL-independent signaling exploited in chronic myeloid leukemia (CML) progression is an important aspect in cancer stem-cell biology. CML stem-cell compartment is dynamic as it progresses to terminal blast crisis where myeloid and lymphoid blasts fail to differentiate. We demonstrate cross-regulation of signaling network involving Sonic hedgehog (Shh), Wnt, Notch and Hox for the inexorable blastic transformation of CD34(+) CML cells. Significant upregulation in Patched1, Frizzled2, Lef1, CyclinD1, p21 (P < or =0.0002) and downregulation of HoxA10 and HoxB4 (P< or =0.0001) transcripts in CD34(+) cells distinguish blast crisis from chronic CML. We report Shh-dependent Stat3 activation orchestrates these mutually interconnected signaling pathways. Stimulation of CD34(+) CML cells with either soluble Shh or Wnt3a did not activate Akt or p44/42-mitogen activated protein kinase (MAPK) pathways. Interestingly, unlike dominant negative Stat3beta, introduction of constitutive active Stat3 in CD34(+) CML cells induces cross-regulation in gene expression. Additionally, Shh and Wnt3a-dependent regulation of cyclin-dependent kinase inhibitors (CDKI) in CML suggests their role in the network. Taken together, our findings propose that deregulation in the form of hyperactive Shh and Wnt with repressed Notch and Hox pathways involving Stat3, Gli3, beta-catenin, CyclinD1, Hes1, HoxA10 and p21 might act synergistically to form an important hub in CML progression.