Association and interaction of -58C>T and ±9 bp polymorphisms of BDKRB2 gene causing susceptibility to essential hypertension.

INTRODUCTION: Bradykinin, a vasodilator by nature has been documented to have a protective role against hypertension and cardiovascular complications. Polymorphisms of bradykinin B2 receptor (BDKRB2) gene are reported to be predisposing factors for hypertension. Evaluation of the association between -58C>T and ±9 bp polymorphisms of BDKRB2 with essential hypertension (EHT) was attempted. METHODS: Two hundred and fourteen primary hypertensives and 249 controls were genotyped for the selected markers by polymerase chain reaction, gel electrophoresis (±9 bp), and SSCP (-58C>T). RESULTS: While -58C>T polymorphism did not reveal any association with EHT, ±9 bp polymorphism showed a significant association with high risk for heterozygotes (+9/-9) when tested against the pooled frequencies of homozygotes (OR [odds ratio] = 1.63, 95% confidence interval [CI] = 1.12-2.38, P = .02), and this risk was 1.7 folds high in males (OR = 1.74, 95% CI = 1.05-2.86, P = .06) and 1.9 folds high in familial cases (OR = 1.96, 95% CI = 1.09-3.53, P = .04). In contrast, significant protective effect was observed for -9/-9 genotype against EHT when tested under dominant model in general (OR = 0.59, 95% CI = 0.41-0.86, P = .01), in males (OR = 0.49, 95% CI = 0.30-0.82, P = .01), and in familial cases (OR = 0.50, 95% CI = 0.28-0.89, P = .04). Significant risk for +9 bp allele was observed in general (OR = 1.39, 95% CI = 1.05-1.86, P = .04) and in males (OR = 1.65, 95% CI = 1.13-2.41, P = .02). The interaction information analysis revealed a synergistic effect between the two polymorphisms contributing to EHT. +9/+9 genotype of ±9 bp polymorphism when present in combination with CC genotype of -58C>T polymorphism showed 2.2-fold higher risk for developing EHT. CONCLUSIONS: The results suggest that allele +9 bp might be a risk factor for EHT in general and specially in males. Markers -58C>T and ±9 bp may act synergistically causing susceptibility to EHT.

TNF-alpha -308G/A and -238G/A polymorphisms and its protein network associated with type 2 diabetes mellitus.

Several reports document the role of tumor necrosis factor alpha (TNF-α) and lipid metabolism in the context of acute inflammation as a causative factor in obesity-associated insulin resistance and as one of the causative parameter of type 2 diabetes mellitus (T2DM). Our aim was to investigate the association between -308G/A and -238G/A polymorphisms located in the promoter region of the TNF-α gene in T2DM in the Indian population with bioinformatics analysis of TNF-α protein networking with an aim to find new target sites for the treatment of T2DM. Demographics of 100 diabetes patients and 100 healthy volunteers were collected in a structured proforma and 3 ml blood samples were obtained from the study group, after approval of Institutional Ethics Committee of the hospital (IEC). The information on clinical parameters was obtained from medical records. Genomic DNA was extracted; PCR-RFLP was performed using TNF-α primers specific to detect the presence of SNPs. Various bioinformatics tools such as STRING software were used to determine its network with other associated genes. The PCR-RFLP studies showed that among the -238G/A types the GG genotype was 87%, GA genotype was 12% and AA genotype was 1%. Almost a similar pattern of results was obtained with TNF-α -308G/A polymorphism. The results obtained were evaluated statistically to determine the significance. By constructing TNF-α protein interaction network we could analyze ontology and hubness of the network to identify the networking of this gene which may influence the functioning of other genes in promoting T2DM. We could identify new targets in T2DM which may function in association with TNF-α. Through hub analysis of TNF-α protein network we have identified three novel proteins RIPK1, BIRC2 and BIRC3 which may contribute to TNF-mediated T2DM pathogenesis. In conclusion, our study indicated that some of the genotypes of TNF-α -308G/A, -238G/A were not significantly associated to type 2 diabetes mellitus, but TNF-α -308G/A polymorphism was reported to be a potent risk factor for diabetes in higher age (>45) groups. Also, the novel hub proteins may serve as new targets against TNF-α T2DM pathogenesis.

Fluorescent amplified fragment length polymorphism (FAFLP) based molecular epidemiology of hospital infections in a tertiary care setting in Hyderabad, India.

Bacterial isolates from respiratory and urinary tract infections in an Indian hospital setting were genotyped using FAFLP analysis. The 77 different isolates analyzed belonged to five genera namely Escherichia, Staphylococcus, Pseudomonas, Enterobacter and Pantoea. Before carrying out FAFLP analysis all the isolates were subjected to16S-23S ribosomal RNA-based species identification. Cluster analysis of FAFLP profiles of 77 isolates generated five groups corresponding to five bacterial genera that are used in the study. Further analyses of the dendrograms revealed efficient species and strain differentiation. Cluster analysis identified genetically distant clones among the clinical isolates of Staphylococcus aureus, two distinct genetic lineages among the Escherichia coli strains and a single cluster of closely related Pseudomonas aeruginosa isolates. Ribosomal spacer region amplification identified different species accurately but intraspecies discrimination could not be accomplished completely. Comparison of FAFLP profiles of our isolates, with a pilot database of validated strains, was very useful in identification and worked better in conjunction with dendrogram analysis.

Association of CYP1A1 Gene Polymorphism with Ischemic Stroke in South Indian Population.

Stroke is a major cause of morbidity and mortality worldwide. Genetic and environmental factors are involved in the pathogenesis of stroke. Hypertension, diabetes mellitus, and cigarette smoking are the major risk factors, and smoking doubles the risk of ischemic stroke. Smoking cessation decreased the risk for ischemic stroke. CYP1A1 is the phase I metabolizing enzyme which plays a key role in metabolic activation of polycyclic aromatic hydrocarbons which are present in cigarette smoke and considered carcinogenic. So far, the association of CYP1A1 gene polymorphism with stroke has not been investigated in Indian population. So, the study is taken up to evaluate the association of this polymorphism with ischemic stroke in a South Indian population. We genotyped 215 ischemic stroke patients and 162 age-matched controls using polymerase chain reaction-restriction fragment length polymorphism. Statistical analysis showed that CYP1A1 "CC" genotype is associated with five times increased risk of ischemic stroke (odds ratio (OR) = 5.14; 95% confidence interval (95% CI) = 1.14-23.14, p = 0.01), while "TT" (OR = 0.78, 95% CI = 0.51-1.19, p = 0.25) and "TC" (OR = 1.04, 95% CI = 0.67-1.60, p = 0.85) genotypes were nonsignificant with the increased risk of stroke. T and C allele frequencies in stroke were 76.5% and 23.5% as against 81.8% and 18.2% in control group, respectively, thus, suggesting no statistically significant differences in the T (OR = 0.72, 95% CI = 0.50-1.03, p = 0.07) and C (OR = 1.37, 95% CI = 0.96-1.97, p = 0.07) allele frequencies between the two groups. The distribution of CYP1A1 genotypes and allelic frequency within the stroke subtypes showed a significant association of CC genotype only in intracranial large artery atherosclerosis (OR = 5.21, 95% CI = 1.03-26.38, p = 0.02) while other subtypes did not show any association. Further analysis of CYP1A1 genotypes in patients and control subjects with smoking habit also showed a similar trend. Hence, we conclude that the CYP1A1 CC genotype is associated with the increased risk of ischemic stroke.

Effect of fixed dose combinations of metoprolol and amlodipine in essential hypertension: MARS--a randomized controlled trial.

AIM: To compare two strengths of a fixed drug combination (FDC) containing metoprolol XL and amlodipine (metoprolol/amlodipine 50/5; and metoprolol/amlodipine 25/2.5) with its components in hypertension. METHODS: We conducted this multicentre, randomized, open-label, trial in Indian patients with hypertension (140-180 mmHg/90-114 mmHg) in 11 centres from nine cities. Eligible patients (n = 402) were randomized into one of five treatment groups (metoprolol XL 50 mg + amlodipine 5 mg, metoprolol XL 25 mg + amlodipine 2.5 mg, metoprolol XL 50 mg, metoprolol XL 25 mg or amlodipine 5 mg) and treated for 8 weeks with five follow-up visits to record blood pressure (BP) and clinical status. RESULTS: At baseline, treatment groups were well balanced; mean +/- SD BP was 154.87 +/- 11.91/96.63 +/- 6.97 mmHg. The greatest reduction in BP from baseline to 8 weeks was seen in the high-dose FDC group (23.61/14.91 mmHg; p<0.001). The remaining 4 groups too demonstrated a significant reduction (p< 0.001): low-dose FDC - 22.29/ - 14.66; metoprolol 50, - 23.17/ - 13.37; metoprolol 25,- 18.41/ 12.50 and amlodipine 5, - 23.01/- 13.08. BP reductions by FDCs, however, were not statistically superior to monotherapies. Responder rates (sitting diastolic BP< 90 mmHg or reduction > or =10 mmHg) were 93% in the high-dose FDC group and 97% in the low-dose FDC group, and control rates (sitting BP < 140/90 mmHg) were 66% and 58%, respectively. These rates were higher than that seen in individual components. There were no reports of serious adverse events related to study medications. One each from the low-dose FDC and metoprolol 25 mg group discontinued because of adverse events. CONCLUSIONS: FDCs of metoprolol and amlodipine are effective and safe in mild to moderate hypertension.