Revisiting the susceptibility testing of Mycobacterium tuberculosis to ethionamide in solid culture medium.

Background & objectives: Increase in the isolation of drug resistant phenotypes of Mycobacterium tuberculosis necessitates accuracy in the testing methodology. Critical concentration defining resistance for ethionamide (ETO), needs re-evaluation in accordance with the current scenario. Thus, re-evaluation of conventional minimum inhibitory concentration (MIC) and proportion sensitivity testing (PST) methods for ETO was done to identify the ideal breakpoint concentration defining resistance. Methods: Isolates of M. tuberculosis (n=235) from new and treated patients were subjected to conventional MIC and PST methods for ETO following standard operating procedures. Results: With breakpoint concentration set at 114 and 156 μg/ml, an increase in specificity was observed whereas sensitivity was high with 80 μg/ml as breakpoint concentration. Errors due to false resistant and susceptible isolates were least at 80 μg/ml concentration. Interpretation & conclusions: Performance parameters at 80 μg/ml breakpoint concentration indicated significant association between PST and MIC methods.

Effect of taurine on carotid intima media thickness in patients with type 2 diabetes mellitus.

Background : Carotid intima-media thickness (CIMT) has been proposed as a surrogate marker to identify diabetic patients at higher risk for CAD. Oxidative stress has been postulated to be involved in the development of atherosclerosis. Objective: The present study was to evaluate the effect of taurine on serum lipids, lipid peroxidation and RBC antioxidant status and vessel changes in type 2diabetes. Design :Twenty individuals T2DM, aged 35 -50 were enrolled. Twenty age and sex-matched healthy individuals served as controls. Taurine was given to both controls and diabetics at a dose of 500mg / day for a period of 30 days. Blood glucose, serum lipids, TBARS in plasma,RBC, antioxidant status in RBC were estimated before and after taurine supplementation. Intima media thickness in both common carotid arteries were assessed by using Doppler B mode ultrsonograghy. Results: Taurine significantly reduced the serum lipids, lipid peroxidation and improved the antioxidant enzymes in diabetics. Intima media thickness was significantly high in type 2 diabetics.Taurine significantly reduced the intima media thickness in both common carotid arteries in type 2 diabetics. Conclusion: Taurine by its antioxidant effect could be useful in retarding atherosclerosis in diabetics and thereby preventing the complications.

Dietary salt intake and hypertension in an urban south Indian population--[CURES - 53].

OBJECTIVE: The aim of the study was to determine the mean dietary salt intake in urban south India and to look at its association with hypertension. METHODS: The Chennai Urban Rural Epidemiology Study (CURES) is an ongoing population based study on a representative population of Chennai city in southern India. Phase 1 of CURES recruited 26,001 individuals aged > or = 20 years, of whom every tenth subject (n = 2600) was invited to participate in Phase 3 for detailed dietary studies and 2220 subjects participated in the present study (response rate: 84.5%). Participants with self-reported history of hypertension, diabetes or heart disease were excluded from the study (n = 318) and thus the final study numbers were 1902 subjects. Dietary salt, energy, macronutrients and micronutrients intake were measured using a validated semi-quantitative food frequency questionnaire. Diagnosis of hypertension was based on the National Cholesterol Education Programme (NCEP) Adult Treatment Panel III criteria. Logistic regression analysis was used to look at the association of dietary salt with hypertension. RESULTS: Mean dietary salt intake (8.5 g/d) in the population was higher than the recommended by the World Health Organization (< 5g/d). Higher salt intake was associated with older age and higher income (p for trend < 0.0001). Subjects in the highest quintile of salt intake had significantly higher prevalence of hypertension than did those in the lowest quintile (48.4 vs 16.6%, p < 0.0001). Both systolic and diastolic blood pressure significantly increased with increase in quintiles of total dietary salt both among hypertensive and normotensive subjects (p for trend p < 0.0001). Addition of salt > 1 teaspoon/day at the dining table was associated with a higher prevalence for hypertension compared to zero added salt (38.5% vs 23.3%, Chi-square = 18.95; p < 0.0001). Multiple logistic regression analysis revealed that even after adjusting for age, gender, body mass index, total energy intake and dietary fat, total dietary salt intake was positively associated with hypertension. [Odds ratio (OR): 1.161, 95% Confidence Interval (CI): 1.115-1.209, p < 0.0001]. CONCLUSION: Intake of dietary salt in urban south India is higher than currently recommended. Increasing salt intake is associated with increased risk for hypertension even after adjusting for potential confounders. This calls for urgent steps to decrease salt consumption of the population at high risk.