Prevalence of Diabetic Retinopathy in Urban India: The Chennai Urban Rural Epidemiology Study (CURES) Eye Study, I

PURPOSE. To assess the prevalence of diabetic retinopathy (DR) in type 2 diabetic subjects in urban India using four-field stereo color photography. METHODS. The Chennai Urban Rural Epidemiology Study (CURES) is a population-based study conducted on a representative population of Chennai (formerly Madras) city in South India. Individuals Ն20 years in age (n ϭ 26,001) were screened for diabetes. Of the 1529 known diabetic subjects, 1382 (90.4%) participated in the study. Subjects with newly detected diabetes (n ϭ 354) by the oral glucose tolerance test (OGTT) also consented to participate in the study. All the subjects underwent four-field stereo color photography, and retinopathy was graded in the color fundus photographs according to Early Treatment Diabetic Retinopathy Study (ETDRS) criteria. RESULTS. The overall prevalence of DR in the population was 17.6% (95% confidence interval [CI]: 15.8 -19.5), which included 20.8% (95% CI: 18.7-23.1) in known diabetic subjects and 5.1% (95% CI: 3.1-8.0) in subjects with newly detected diabetes. The prevalence of DR was significantly higher in men than in women (21.3% vs. 14.6%; P Ͻ 0.0001) and among subjects with proteinuria (P ϭ 0.002). Logistic regression analysis showed that for every 5-year increase in the duration of diabetes, the risk for DR increased 1.89-fold (95% CI: 1.679 -2.135; P Ͻ 0.0001). For every 2% elevation of glycated hemoglobin (HbA1c), the risk for DR increased by a factor of 1.7 (95% CI: 1.545-1.980; P Ͻ 0.0001). CONCLUSIONS. This study shows that the prevalence of diabetic retinopathy is lower in urban South Indians than in other ethnic groups. However, due to the large number of diabetic subjects, DR is likely to pose a public health burden in India; hence, routine retinal examination is mandatory to detect DR in the early stages. (Invest Ophthalmol Vis Sci. 2005;46: 2328 -233

Reduced Graphene Oxide-Poly(3,4-ethylenedioxythiophene) Polystyrenesulfonate Based Dual-Selective Sensor for Iron in Different Oxidation States

A dual-selective sensor platform for detection of iron in ferrous (Fe²⁺) and ferric (Fe³⁺) oxidation states was developed. Upon dispersing reduced graphene oxide (rGO) sheets into poly­(3,4-ethylenedioxythiophene) polystyrenesulfonate (PEDOT:PSS) polymer, we deposited a hybrid film of rGO-PEDOT:PSS onto a glassy carbon electrode (GCE) surface. Effective intercalation of rGO sheets in PEDOT:PSS film was observed by Raman spectroscopy, UV–vis-NIR spectroscopy, and scanning electron microscopy. The rGO-PEDOT:PSS/GCE sensor showed high electrocatalytic activity for Fe²⁺/Fe³⁺ redox reaction. Using amperometry with controlled applied potential, we demonstrated selective detection of both Fe²⁺ and Fe³⁺ with rGO-PEDOT:PSS/GCE. The sensor responded linearly to Fe²⁺ from 20–833 μM (at 0.6 V) and Fe³⁺ from 1–833 μM (at 0.4 V) in 0.5 M KCl + 0.05 M HCl. The presence of several common metal and organic interferents such as Cu²⁺, Co²⁺, Ag⁺, Pb²⁺, Cd²⁺, Zn²⁺, Mn²⁺, Ni²⁺, Hg²⁺, l-glycine, l-cysteine, l-tyrosine, glucose, KCN, guanine, uric acid, xanthan, salicylate, tartrazine, and naphthol yellow did not affect the selective detection of Fe²⁺ and Fe³⁺. In addition, detection of Fe²⁺ and Fe³⁺ ions in a red wine sample and iron supplement tablets were performed with satisfactory results. The sensor was also useful in determining oxidation kinetics of Fe²⁺ using hydrogen peroxide and measuring Fe³⁺ by differential pulse voltammetry. Thus, rGO/PEDOT:PSS hybrid film based electrode we developed can serve as a practical sensor for detecting iron in its different oxidation states in real samples for different applications

Prevalence of diabetic retinopathy in Urban India: the Chennai Urban Rural Epidemiology Study (CURES) eye study, I

Purpose: To assess the prevalence of diabetic retinopathy (DR) in type 2 diabetic subjects in urban India using four-field stereo color photography. Methods: The Chennai Urban Rural Epidemiology Study (CURES) is a population-based study conducted on a representative population of Chennai (formerly Madras) city in South India. Individuals ≥20 years in age (n = 26,001) were screened for diabetes. Of the 1529 known diabetic subjects, 1382 (90.4%) participated in the study. Subjects with newly detected diabetes (n = 354) by the oral glucose tolerance test (OGTT) also consented to participate in the study. All the subjects underwent four-field stereo color photography, and retinopathy was graded in the color fundus photographs according to Early Treatment Diabetic Retinopathy Study (ETDRS) criteria. Results: The overall prevalence of DR in the population was 17.6% (95% confidence interval [CI]: 15.8-19.5), which included 20.8% (95% CI: 18.7-23.1) in known diabetic subjects and 5.1% (95% CI: 3.1-8.0) in subjects with newly detected diabetes. The prevalence of DR was significantly higher in men than in women (21.3% vs. 14.6%; P &lt; 0.0001) and among subjects with proteinuria (P = 0.002). Logistic regression analysis showed that for every 5-year increase in the duration of diabetes, the risk for DR increased 1.89-fold (95% CI: 1.679-2.135; P &lt; 0.0001). For every 2% elevation of glycated hemoglobin (HbA<SUB>1c</SUB>), the risk for DR increased by a factor of 1.7 (95% CI: 1.545-1.980; P &lt; 0.0001). Conclusions. This study shows that the prevalence of diabetic retinopathy is lower in urban South Indians than in other ethnic groups. However, due to the large number of diabetic subjects, DR is likely to pose a public health burden in India; hence, routine retinal examination is mandatory to detect DR in the early stages

Intrinsic halotolerance of the psychrophilic alpha-amylase from Pseudoalteromonas haloplanktis

The halotolerance of a cold adapted alpha-amylase from the psychrophilic bacterium Pseudoalteromonas haloplanktis (AHA) was investigated. AHA exhibited hydrolytic activity over a broad range of NaCl concentrations (0.01-4.5 M). AHA showed 28% increased activity in 0.5-2.0 M NaCl compared to that in 0.01 M NaCl. In contrast, the corresponding mesophilic (Bacillus amyloliquefaciens) and thermostable (B. licheniformis) alpha-amylases showed a 39 and 46% decrease in activity respectively. Even at 4.5 M NaCl, 80% of the initial activity was detected for AHA, whereas the mesophilic and thermostable enzymes were inactive. Besides an unaltered fluorescence emission and secondary structure, a 10 degrees C positive shift in the temperature optimum, a stabilization factor of > 5 for thermal inactivation and a Delta T-m of 8.3 degrees C for the secondary structure melting were estimated in 2.7 M NaCl. The higher activation energy, half-life time and T-m indicated reduced conformational dynamics and increased rigidity in the presence of higher NaCl concentrations. A comparison with the sequences of other halophilic alpha-amylases revealed that AHA also contains higher proportion of small hydrophobic residues and acidic residues resulting in a higher negative surface potential. Thus, with some compromise in cold activity, psychrophilic adaptation has also manifested halotolerance to AHA that is comparable to the halophilic enzymes