Surya Kumar Singh

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.

Prevalence and severity of vitamin D deficiency in patients with diabetic foot infection

The aim of the present research was to study the prevalence and severity of vitamin D deficiency in patients with diabetic foot infection. Patients were enrolled in two groups: diabetic patients with foot infection (n 125) as cases and diabetic patients without the infection as controls (n 164). Serum 25-hydroxyvitamin D (25(OH)D) was measured by RIA. Data were presented as means and standard deviations unless otherwise indicated and were analysed by SPSS. Results revealed that 25(OH)D (nmol/l) was significantly lower (40·25 (sd 38·35) v. 50·75 (sd 33·00); P < 0·001) in cases than in controls. Vitamin D inadequacy (25(OH)D < 75 nmol/l) was equally common in cases and controls (OR 1·45, 95 % CI 0·8, 3·0; P = 0·32), but cases had a greater risk of vitamin D deficiency (25(OH)D < 50 nmol/l) than controls (OR 1·8, 95 % CI 1·1, 3·0; P = 0·02). Risk of severe vitamin D deficiency (25(OH)D < 25 nmol/l) was significantly higher in cases than in controls (OR 4·0, 95 % CI 2·4, 6·9; P < 0·0001). Age, duration of diabetes and HbA1c were significantly higher in cases than in controls and therefore adjusted to nullify the effect of these variables, if any, on study outcome. The study concluded that vitamin D deficiency was more prevalent and severe in patients with diabetic foot infection. This study opens up the issue of recognising severe vitamin D deficiency (< 25 nmol/l) as a possible risk factor for diabetic foot infections and the need for vitamin D supplementation in such patients for a better clinical outcome. This could be substantiated by similar data from future studies.

Rapid Genotypic Detection of rpoB and katG Gene Mutations in Mycobacterium tuberculosis Clinical Isolates from Northern India as Determined by MAS-PCR

There is a growing need to develop rapid laboratory research methods to counter the menace of drug resistant tuberculosis (MDR‐TB) cases worldwide especially in developing countries. The present study was undertaken to investigate the type and frequency of rpoB and katG mutations in rifampicin (RIF) and isoniazid (INH) resistant strains respectively of Mycobacterium tuberculosis (MTB) circulating in Northern India and to explore the utility of multiplex‐allele‐specific (MAS)‐PCR assay for detection of drug‐resistant MTB isolates in low resource set up. J. Clin. Lab. Anal. 27:31–37, 2013.

A new approach to touch down method using betaine as co-solvent for increased specificity and intensity of GC rich gene amplification.

Tissue specific genes that contain high GC segments are difficult to amplify by standard PCR. We report an improved method for successful amplification of gene segment that has >70% GC base pairs. This new method of touch down PCR differed by having an initial annealing temperature (Ta) 1.5°C below the primers melting temperature that descended 0.2°C per cycle for 20 cycles and continued thereafter at fixed Ta for next 15 cycles. Different co-solvents were tested with this method to improve the result and betaine proved better than the other co-solvents. This new method is economical, fast and specific in amplifying GC rich region of other genes also.

Waist circumference cutoff and its importance for diagnosis of metabolic syndrome in Asian Indians: A preliminary study

Background: There is inconsistency in accepting waist circumference (WC) as mandatory and also regarding its significance for diagnosis of metabolic syndrome (MetS) for different populations. Aim: To study the association of individual parameters of MetS with WC cutoffs suitable for South Asian Indians. Materials and Methods: From an ongoing hospital-based study on MetS as per the criteria of diagnosis of modified NCEP ATP III, 713 subjects having a minimum three of the four parameters, i.e., dyslipidemia [low high density lipoprotein (HDL), high triglycerides], dysglycemia and hypertension, without regard to cutoffs of WC, were included in the present study. Results: Receiver operator characteristic curve analysis of WC cut-off points for males was 90 cm with a sensitivity and specificity of 71% and 96%, respectively, and for females was 85 cm with a sensitivity and specificity of 86% and 93%, respectively, associated with the risk factors of MetS. Multiple logistic regression analysis for low density lipoprotein (LDL) cholesterol concentration of ≥3.38 mmol/l showed an odds ratio of 5.03 (95% CI = 1.29–19.5) in males and 3.17 (95% CI = 1.14–8.76) in females which was statistically significant (P < 0.02); in addition to higher WC, higher level of triglyceride (P ≤ 0.0001) and lower level of high density lipoprotein cholesterol (P ≤ 0.02) were observed. Conclusion: This study suggests that WC of 90 cm in males and 85 cm in females should be a mandatory criterion of MetS in our subset of population. LDL may be considered one of the components of MetS along with the currently defined WC cutoffs.

The Etiopathogenesis of the Diabetic Foot: An Unrelenting Epidemic

Diabetes mellitus is a metabolic disease that is associated with hyperglycemia affecting various organ systems of the body. One of the most dreaded complications of this disease is the diabetic foot. The diabetic foot is the end result of multiple causal pathways, which include peripheral neuropathy and vascular disease. The problem is compounded by the increased incidence of infection. This article deals with the various pathogenic pathways associated with the development of the diabetic foot.

Squamous Cell Carcinoma Developing in a Diabetic Foot Ulcer

Documented cases of malignant transformation of foot ulcer in a diabetic patient in medical literature are very few. This study presents 2 interesting cases of long-standing diabetic foot ulcer, which were subsequently diagnosed to have squamous cell carcinoma on histopathological examination.

Identification, antifungal resistance profile, in vitro biofilm formation and ultrastructural characteristics of Candida species isolated from diabetic foot patients in Northern India.

Purpose: Diabetic foot ulcers are a serious cause of diagnostic and therapeutic concern. The following study was undertaken to determine the fungal causes of diabetic foot ulcers, with their phenotypic and genotypic characterisation. Materials and Methods: A total of 155 diabetic foot ulcers were studied for 1 year. Deep tissue specimen was collected from the wounds, and crushed samples were plated on Sabouraud dextrose agar with chloramphenicol (0.05 g). Identification was done by growth on cornmeal agar, germ tube formation and urease test. For molecular identification, conserved portion of the 18S rDNA region, the adjacent internal transcribed spacer 1 (ITS1) and a portion of the 28S rDNA region were amplified, using the ITS1 and ITS2 primers. Antifungal susceptibility against voriconazole, fluconazole and amphotericin B was determined by standard broth microdilution method. Biofilm formation was studied in three steps. First, on the surface of wells of microtiter plates followed by quantification of growth by fungal metabolism measurement. Finally, biofilms were analysed by scanning electron microscopy (SEM). Results: Fungal aetiology was found in 75 patients (48.38%). All were identified as Candida species (100%). The prevalence of different species was Candida tropicalis (34.6%), Candida albicans (29.3%), Candida krusei (16.0%), Candida parapsilosis (10.6%), Candida glabrata (9.33%). All were susceptible to amphotericin B (100%). On microtiter plate, all the isolates were viable within 48 h showing biofilms. The metabolic activity of cells in the biofilm increased with cellular mass, especially in the first 24 h. On SEM, majority showed budding yeast form. Conclusion: Non-albicans Candida spp. with potential biofilm forming ability are emerging as a predominant cause of diabetic foot ulcers.

Risk factors of diabetes in North Indians with metabolic syndrome

AIM Metabolic syndrome progresses to diabetes and determinants of this progression like hyperinsulinemia, hypertriglyceridemia and genetic factors have been speculative. The present study was aimed at quantifying the insulin resistance and influence of family history of diabetes in subjects with metabolic syndrome developing prediabetes and diabetes. METHODS Consecutive subjects attending the endocrine clinic were evaluated for metabolic syndrome as per definition of International Diabetes Federation, 2005. The family history of diabetes in their first degree relatives was ascertained and Homeostasis model assessment of Insulin resistance (HOMA-IR), Homeostasis model assessment for beta cell function (HOMA-B) and Quantitative insulin sensitivity check index (QUICKI) were calculated in 163 subjects enrolled. RESULTS HOMA-IR was higher (p<0.05) but HOMA-B and QUICKI were lower (p<0.0001) in subjects with metabolic syndrome+prediabetes or diabetes compared to metabolic syndrome with normal glucose tolerance. HOMA-B was lower and prevalence of prediabetes and diabetes was higher in metabolic syndrome subjects with family history of diabetes than in those without such family history (p<0.05). CONCLUSIONS subjects with metabolic syndrome having prediabetes and diabetes had more severe insulin resistance than those with metabolic syndrome only. Beta cell dysfunction was remarkable and prevalence of prediabetes was high in metabolic syndrome subjects with family history of diabetes. Both the severity of the insulin resistance and family history of diabetes are therefore proposed to be determinants of diminished Beta cell function leading to diabetes in metabolic syndrome.

Vitamin D status of patients with type 2 diabetes and sputum positive pulmonary tuberculosis

Introduction: Vitamin D deficiency is expected to be higher in patients with diabetes and pulmonary tuberculosis (TB). Studies estimating prevalence in the subset of patients with both diabetes and pulmonary TB are scarce. Materials and Methods: A total of 155 subjects were recruited; 46 patients with type 2 diabetes, 39 non-diabetic healthy controls, 30 patients of pulmonary TB and 40 patients with both pulmonary TB and type 2 diabetes. Vitamin D level (25 OH vitamin D) levels were done for all the 4 groups. Results: Mean vitamin D levels were not different between groups with TB, diabetes mellitus or combination of both, but the prevalence of severe vitamin D deficiency was higher in the group with both diabetes and TB (45%) as compared with the group with only TB (26.66%) and diabetes (17.39%) and healthy controls (7.69%). Conclusion: The prevalence of patients with severe vitamin D deficiency is higher in patients with dual affection of TB and diabetes mellitus as compared with either disorder alone implying that patients with type 2 diabetes with the most severe vitamin D deficiency are the one of the most predisposed to pulmonary TB.