Monte Carlo simulation and experimental validation of plant microtubules cathode in biodegradable battery

For the first time, electrochemical methods are utilized to study the response of tubulin monomers (extracted from plant source such as Green Peas: Arachis Hypogea) towards charge perturbations in the form of conductivity, conformational changes via self-assembly and adsorption on Au surface. The obtained dimerization and surface adsorption energetics of the tubulins from Cyclic Voltammetry agree well with the literature value of 6.9 and 14.9 kCal/mol for lateral and longitudinal bond formation energy respectively. In addition to the effects of charge perturbations on change in structure, ionic and electronic conductivity of tubulin with increasing load are investigated and found to be 1.25 Sm^-1 and 2.89 mSm^-1 respectively. The electronic conductivity is 1.93 times higher than the literature value of 1.5 mSm^-1, demonstrating the fact that the microtubules (dimer of tubulins, MTs) from plant source can be used as a semiconductor electrode material in energy conversion and storage applications. Thus, motivated by the Monte Carlo simulation and electrochemical results the MTs extracted from plant source are used as cathode material for energy storage device such as Bio-battery and the Galvanostatic Charge/Discharge studies are carried out in coin cell configuration. The configuration of the bio-battery cell is as follows: Al/CB//PP-1M KCl//MTs/SS; where SS and Al are used as current collectors for cathode and anode respectively, Polypropylene (PP) membrane soaked in 1M KCl as electrolyte and Carbon Black (CB) is the anode material. Another configuration of the cell would be replacement of CB by biopolymer such as ethyl cellulose anode (Al/EC/PP-1M KCl/MTs/SS).

Computational mechanistic insights on Ag2O as a host for Li in lithium-ion batteries

The lithiation mechanism of Ag₂O with one and two Li atoms per unit cell carried out using density functional theory (DFT) studies indicate the adsorption of one Li atom at the tetrahedral interstitial site (TIS) as the most stable one with the formation of the Li-Ag₂O compound. PDOS plots depict the hybridization of Li 2s with O 2p and Ag 5s states, resulting in the formation of both Li-O and Li-Ag bonds. Also, the Bader charge analysis validates the bonding of Li at TIS with both Ag and O atoms. The band structure plots showcase a surge in electronic conductivity, accounting for the metallic transition of Ag₂O with the addition of Li. The difference in the charge distribution between the pairs of surface and subsurface silver atoms in charge density difference plots (CDDP) reveal the incorporation of Li, invoking charge inequivalence in addition to the symmetry inequivalence in the optimized structure. In the case of two Li atoms, Li placed on the top of oxygen (O_top) and at the subsurface of silver (Ag_ss) was found to be the most stable structure with the formation of two strong Li-O bonds, indicating the feasibility of the conversion mechanism. The increase in the Bader charge of O (-1.28e) as well as CDDP establish the formation of Li₂O by the conversion mechanism. Thus, the increase in the Li⁺ ion concentration becomes the deciding factor for the transition of the lithiation mechanism from Li-Ag₂O compound formation to the conversion mechanism. The molecular dynamics (MD) simulations feature Li as an "antisite defect producing guest", leading to the formation of Li-O bonds with a concomitant reduction in the number of Ag-O bonds as a function of time. This confirms a shift in the reaction kinetics from the formation of Li-Ag₂O to the conversion mechanism.

Investigation of Adsorption Behavior of Anticancer Drug on Zinc Oxide Nanoparticles: A Solid State NMR and Cyclic Voltammetry (CV) Analysis

The present study aims to comprehend the adsorption behavior of a set of anticancer drugs namely 5-fluorouracil (5-FU), doxorubicin and daunorubicin on ZnO nanoparticles (ZnO NPs) proposed as drug delivery systems employing solid state (ss) NMR, FTIR and Cyclic Voltammetry (CV) analysis. FTIR and ¹H MAS ssNMR data recorded for bare ZnO nanoparticle confirmed the presence of adsorbed -OH groups on the surface. ¹³C CP-MAS NMR spectra recorded for free and ZnO surface adsorbed drug samples exhibited considerable line broadening and chemical shift changes that complemented our earlier report on UV-DRS and XRD data of surface adsorption in case of 5-FU. Moreover, a remarkable enhancement of ¹³C signal intensity in case of loaded 5-FU was observed. This clearly indicated rigid nature of the drug on the surface allowing efficient transfer of ¹H polarization from the hetero nitrogen of 5-FU to ZnO to form surface hydroxyl (-OH) groups and the same has been observed in the quantum chemical calculations. To further analyze the motional dynamics of the surface adsorbed 5-FU, longitudinal relaxation times (T₁) were quantified employing Torchia method that revealed significant enhancement of ¹³C relaxation rate of adsorbed 5-FU. The enhanced rate suggested an effective role of quadrupolar contribution from ⁶⁷Zn to the ¹³C relaxation mechanism of ZnO_5-FU. The heterogeneous rate constant (k_het), average free energy of activation (∆G^≠) and point of zero charge (PZC) measured for free and drug loaded ZnO NPs samples using CV further support the SS-NMR results.

Are excess carbohydrates the main link to diabetes & its complications in Asians?

Dietary carbohydrates form the major source of energy in Asian diets. The carbohydrate quantity and quality play a vital function in the prevention and management of diabetes. High glycaemic index foods elicit higher glycaemic and insulinaemic responses and promote insulin resistance and type 2 diabetes (T2D) through beta-cell exhaustion. This article reviews the evidence associating dietary carbohydrates to the prevalence and incidence of T2D and metabolic syndrome (MS) in control of diabetes and their role in the complications of diabetes. Cross-sectional and longitudinal studies show that higher carbohydrate diets are linked to higher prevalence and incidence of T2D. However, the association seems to be stronger in Asian-Indians consuming diets high in carbohydrates and more marked on a background of obesity. There is also evidence for high carbohydrate diets and risk for MS and cardiovascular disease (CVD). However, the quality of carbohydrates is also equally important. Complex carbohydrates such as brown rice, whole wheat bread, legumes, pulses and green leafy vegetables are good carbs. Conversely, highly polished rice or refined wheat, sugar, glucose, highly processed foods such as cookies and pastries, fruit juice and sweetened beverages and fried potatoes or French fries are obviously ‘bad’ carbs. Ultimately, it is all a matter of balance and moderation in diet. For Indians who currently consume about 65-75 per cent of calories from carbohydrates, reducing this to 50-55 per cent and adding enough protein (20-25%) especially from vegetable sources and the rest from fat (20-30%) by including monounsaturated fats (e.g. groundnut or mustard oil, nuts and seeds) along with a plenty of green leafy vegetables, would be the best diet prescription for the prevention and management of non-communicable diseases such as T2D and CVD.

Thermodynamic insights into the free energy of the processes in lithium iron phosphate batteries

Thermodynamic insights into the free energy of the discharge processes in lithium iron phosphate batteries.

A selective and sensitive high performance liquid chromatography assay for the determination of cycloserine in human plasma

BACKGROUND

Cycloserine (CYC) is a second line antitubercular drug that is used for the treatment of multidrug resistant tuberculosis (MDR-TB) along with other antitubercular agents and is often used in developing countries. Monitoring CYC levels in plasma could be useful in the clinical management of patients with MDR-TB. A high performance liquid chromatography method for the determination of CYC in human plasma was developed.

METHODS

The method involved extraction of the sample using solid phase extraction cartridges and analysis of the extracted sample using a reverse phase T3 column (150mm) and detection at 240nm with Photo Diode Array (PDA) detector. The chromatogram was run for 15min at a flow rate of 0.4ml/min at 30°C.

RESULTS AND CONCLUSION

The assay was specific for CYC and linear from 5.0 to 50.0μg/ml. The relative standard deviations of within- and between-day assays were less than 10%. Recovery of CYC ranged from 102% to 109%. The interference of other second line anti-TB drugs in the assay of CYC was ruled out. The assay spans the concentration range of clinical interest. The specificity and sensitivity of this assay makes it highly suitable for pharmacokinetic studies.

N-acetyltransferase gene polymorphisms & plasma isoniazid concentrations in patients with tuberculosis

Background & objectives:

Variations in the N-acetyltransferase (NAT2) gene among different populations could affect the metabolism and disposition of isoniazid (INH). This study was performed to genotype NAT2 gene polymorphisms in tuberculosis (TB) patients from Chennai, India, and compare plasma INH concentrations among the different genotypes.

Methods:

Adult patients with TB treated in the Revised National TB Control Programme (RNTCP) in Chennai, Tamil Nadu, were genotyped for NAT2 gene polymorphism, and two-hour post-dosing INH concentrations were compared between the different genotypes. Plasma INH was determined by high-performance liquid chromatography. Genotyping of the NAT2 gene polymorphism was performed by real-time polymerase chain reaction method.

Results:

Among the 326 patients genotyped, there were 189 (58%), 114 (35%) and 23 (7%) slow, intermediate and fast acetylators, respectively. The median two-hour INH concentrations in slow, intermediate and fast acetylators were 10.2, 8.1 and 4.1 μg/ml, respectively. The differences in INH concentrations among the three genotypes were significant (P<0.001).

Interpretation & conclusions:

Genotyping of TB patients from south India for NAT2 gene polymorphism revealed that 58 per cent of the study population comprised slow acetylators. Two-hour INH concentrations differed significantly among the three genotypes.

Pharmacokinetics of thrice-weekly rifampicin, isoniazid and pyrazinamide in adult tuberculosis patients in India

OBJECTIVE

To study the pharmacokinetics of rifampicin (RMP), isoniazid (INH) and pyrazinamide (PZA) in adult tuberculosis (TB) patients and examine factors that influence drug pharmacokinetics.

METHODS

Adult TB patients (n = 101) receiving thrice-weekly anti-tuberculosis treatment in the Revised National TB Control Programme (RNTCP) were studied. The study was conducted at steady state after directly observed drug administration. RMP, INH and PZA concentrations were estimated using high-performance liquid chromatography and NAT2 genotyping by real-time polymerase chain reaction.

RESULTS

RMP peak concentration (Cmax) was sub-therapeutic (<8 μg/ml) in 88% of the patients. The Cmax of RMP, INH and PZA at 2 h was observed in respectively 83.2%, 97.0% and 92.1% of the patients. The Cmax and area under the curve from 0 to 8 h (AUC0-8) of PZA was lower in TB patients with diabetes mellitus than in non-diabetics. Significant associations were observed between the Cmax and the AUC0-8 of RMP, INH and PZA with drug doses; RMP with category of treatment; INH with smoking, body mass index and N-acetyl transferase 2 genotype; and PZA with sex and smoking.

CONCLUSIONS

Several risk factors for drug concentration variations were identified. Two-hour post-dosing drug concentrations mimicked Cmax. A high proportion of TB patients had RMP Cmax below the expected range, which is a matter of concern.

l-Alanine capping of ZnO nanorods: increased carrier concentration in ZnO/CuI heterojunction diode

ZnO nanorods were capped with a simple amino acid, viz., l-alanine to increase the carrier concentration and improve the performance of ZnO/CuI heterojunction diodes. The effect of l-alanine capping on the morphology, structural, optical, electrochemical and electrical properties of ZnO nanorods had been studied in detail. The stable structure with two equally strong Zn–O coordinate bonds predicted by density functional theory was in agreement with the experimental results of FTIR spectroscopy. Due to the presence of electron-releasing (+I effect) moieties in l-Alanine, the carrier concentration of capped ZnO nanorods was two orders of magnitude higher and the ZnO/CuI heterojunction device showed more than a two-fold increase in the photovoltaic power conversion efficiency.

ZnO nanorods were capped with a simple amino acid, viz., l-Alanine to increase the carrier concentration and improve the performance of ZnO/CuI heterojunction diodes.

High fat diet modifies the association of lipoprotein lipase gene polymorphism with high density lipoprotein cholesterol in an Asian Indian population

Background

Single nucleotide polymorphisms (SNPs) in lipoprotein lipase gene (LPL) have been shown to influence metabolism related to lipid phenotypes. Dietary factors have been shown to modify the association between LPL SNPs and lipids; however, to date, there are no studies in South Asians. Hence, we tested for the association of four common LPL SNPs with plasma lipids and examined the interactions between the SNPs and dietary factors on lipids in 1,845 Asian Indians.

Methods

The analysis was performed in 788 Type 2 diabetes cases and 1,057 controls randomly chosen from the cross-sectional Chennai Urban Rural Epidemiological Study. Serum triacylglycerol (TAG), serum total cholesterol, and high-density lipoprotein cholesterol (HDL-C) were measured using a Hitachi-912 autoanalyzer (Roche Diagnostics GmbH, Mannheim, Germany). Dietary intake was assessed using a semi-quantitative food frequency questionnaire. The SNPs (rs1121923, rs328, rs4922115 and rs285) were genotyped by polymerase chain reaction followed by restriction enzyme digestion and 20% of samples were sequenced to validate the genotypes obtained. Statistical Package for Social Sciences for Windows version 22.0 (SPSS, Chicago, IL) was used for statistical analysis.

Results

After correction for multiple testing and adjusting for potential confounders, SNPs rs328 and rs285 showed association with HDL-C (P = 0.0004) and serum TAG (P = 1×10⁻⁵), respectively. The interaction between SNP rs1121923 and fat intake (energy %) on HDL-C (P = 0.003) was also significant, where, among those who consumed a high fat diet (28.4 ± 2.5%), the T allele carriers (TT + XT) had significantly higher HDL-C concentrations (P = 0.0002) and 30% reduced risk of low HDL-C levels compared to the CC homozygotes. None of the interactions on other lipid traits were statistically significant.

Conclusion

Our findings suggest that individuals carrying T allele of the SNP rs1121923 have increased HDL-C levels when consuming a high fat diet compared to CC homozygotes. Our finding warrants confirmation in prospective studies and randomized controlled trials.

Electronic supplementary material

The online version of this article (doi:10.1186/s12986-016-0155-1) contains supplementary material, which is available to authorized users.

A phenomenological thermodynamic approach for evaluating the energetics involved in the discharge of lithium ion battery

Illustrative representation of the discharge process in lithium ion battery constituted by porous electrodes.

Grand Canonical Monte Carlo coupled multiscale simulation for electrochemical and solvent parameters of silver halide systems in water

Grand Canonical Monte Carlo methods in conjunction with continuum Multiscale simulation to estimate the hydration energies and surface potentials of silver halides as demonstrated elsewhere is employed by incorporating random distribution of molecules, nearest neighbor distances and hydration numbers. The extent of dehydration during each step and the corresponding variation in the hydration numbers are evaluated, assuming the validity of hard spheres. These estimates are then employed to deduce the redox potential of the reaction viz. 2AgX(solution)⇔2Ag(solid)+X2(gas). The dependence of these values on the nature of the halides and solvation characteristics is indicated.

Pharmacokinetics of rifabutin during atazanavir/ritonavir co-administration in HIV-infected TB patients in India

SETTING

Rifabutin (RBT) is reported to be as effective as and to have less inducing effect on cytochrome P450 enzymes than rifampicin against tuberculosis (TB). The optimal dose of RBT during ritonavir (RTV) co-administration remains a matter of debate.

OBJECTIVE

To study the pharmacokinetics of 150 mg RBT thrice weekly during concomitant atazanavir/RTV administration in human immunodeficiency virus (HIV) infected TB patients.

METHODS

This observational study was conducted in 16 adult HIV-infected TB patients being treated for TB with an RBT-containing regimen and an antiretroviral therapy regimen with RTV; the dose of RBT was 150 mg thrice weekly. Serial blood draws were performed at pre-dosing and at 1, 2, 4, 6, 8, 12 and 24 h after the drug was administered. Plasma RBT was estimated using high-performance liquid chromatography.

RESULTS AND CONCLUSIONS

Peak RBT concentration was below the lower therapeutic limit (<0.3 μg/ml) in seven patients, while 10 patients had trough concentrations below the minimal inhibitory concentration against Mycobacterium tuberculosis (0.06 μg/ml), suggesting that the RBT dosage may be inadequate. Prospective studies in different settings are required to arrive at the proper therapeutic dose for RBT to be used during co-administration with RTV.

Simple and Rapid Liquid Chromatography Method for Determination of Rifabutin in Plasma

A high performance liquid chromatographic method for determination of rifabutin in human plasma was  developed. The method involved deproteinisation of the sample with acetonitrile and analysis of the  supernatant using a reversed-phase C18 column (250mm) and UV detection at a wavelength of 265nm.  The assay was specific for rifabutin and linear from 0.025 to 10.0μg/ml. The relative standard deviation  of intra- and inter-day assays was lower than 10%. The method was able to remove interfering materials  in plasma, yielding an average recovery of rifabutin from plasma of 101%. Due to its simplicity, the assay  can be used for pharmacokinetic studies of rifabutin. SAARC Journal of Tuberculosis, Lung Diseases & HIV/AIDS; 2012; IX(2) 26-29 DOI: http://dx.doi.org/10.3126/saarctb.v9i2.7975

Association between Medication Adherence Outcomes and Adverse Drug Reactions to Highly Active Antiretroviral Therapy in Indian Human Immunodeficiency Virus-Positive Patients

In India, interruptions to highly active antiretroviral therapy (HAART) are due to adverse drug reactions. This study was aimed to assess the association between HAART adherence and adverse drug reactions (ADRs) in human immunodeficiency virus (HIV) patients. This prospective study was conducted at a Medicine department in a South Indian tertiary care teaching hospital. HIV-positive patients were interviewed for adherence using ACTG adherence questionnaire and intensively monitored for ADRs to HAART. The percentage of adherence was calculated based on missed doses, and graded as less than 80%, 80-95%, and >95%. The World Health Organization (WHO) probability scale was used for causality assessment. Logistic regression analysis as well as univariate analysis was used to assess the association (P value < 0.05). A total of 105 HIV-positive patients had been taking HAART out of whom 50 (47.6%) patients agreed for adherence assessment, and 23 (21.9%) refused due to social stigma. Upon evaluation of the patient characteristics in the reported adherence, 78% were in males (53.8%) and 22% were in females (46.2%) with the level of adherence greater than 95%. Six (12%) patients had a regular alcoholic intake with adherence less than 80% compared to 31 (62%) patients who never had any alcoholic intake (P < 0.05). A significant association between ADRs and adherence was found (P < 0.05). Causality found by the WHO scale was "probable." Clinicians must focus on education regarding the need for adherence, possible adverse effects, and early detection and prevention of ADRs to HAART.

Finger millet (Ragi, Eleusine coracana L.): a review of its nutritional properties, processing, and plausible health benefits

Finger millet or ragi is one of the ancient millets in India (2300 BC), and this review focuses on its antiquity, consumption, nutrient composition, processing, and health benefits. Of all the cereals and millets, finger millet has the highest amount of calcium (344mg%) and potassium (408mg%). It has higher dietary fiber, minerals, and sulfur containing amino acids compared to white rice, the current major staple in India. Despite finger millet's rich nutrient profile, recent studies indicate lower consumption of millets in general by urban Indians. Finger millet is processed by milling, malting, fermentation, popping, and decortication. Noodles, vermicilli, pasta, Indian sweet (halwa) mixes, papads, soups, and bakery products from finger millet are also emerging. In vitro and in vivo (animal) studies indicated the blood glucose lowering, cholesterol lowering, antiulcerative, wound healing properties, etc., of finger millet. However, appropriate intervention or randomized clinical trials are lacking on these health effects. Glycemic index (GI) studies on finger millet preparations indicate low to high values, but most of the studies were conducted with outdated methodology. Hence, appropriate GI testing of finger millet preparations and short- and long-term human intervention trials may be helpful to establish evidence-based health benefits.

Simple and rapid liquid chromatography method for simultaneous determination of isoniazid and pyrazinamide in plasma

Introduction: Treatment of tuberculosis (TB) requires a combination of drugs. Isoniazid (INH) and pyrazinamide (PZA) are key components of the fi rst-line regimen used in the treatment of TB and monitoring these drug levels in plasma would help in better patient care. The objective of the study is to develop and validate a simple and rapid high performance liquid chromatographic method for simultaneous determination of INH and PZA in human plasma. Methodology: The method involved deproteinisation of plasma with para hydroxy benzaldehyde and trifl uoroacetic acid and analysis using a reversed-phase C8 column and UV detection at 267nm. The fl ow rate was set at 1.5 ml/min at ambient temperature. The accuracy, linearity, precision, specifi city, stability and recovery of the method were evaluated. The method was applied to estimate plasma INH and PZA collected from six children with TB. Results: Well resolved peaks of PZA and INH at retention times of 3.2 and 6.1 minutes respectively were obtained. The assay was linear from 0.25 - 10.0 ìg/ml for INH and 1.25 – 50.0 ìg/ml for PZA. The within-day and between-day relative standard deviation for standards were below 10%. The average recoveries of INH and PZA from plasma were 104 and 102% respectively. Conclusions: A rapid and accurate method for simultaneous determination of INH and PZA in plasma was validated. The assay spans the concentration range of clinical interest. The easy sample preparation and small sample size makes this assay highly suitable for pharmacokinetic studies of INH and PZA in TB patients. SAARC Journal of Tuberculosis, Lung Diseases & HIV/AIDS 2012; IX (1) 13-18 DOI: http://dx.doi.org/10.3126/saarctb.v9i1.6960

Thermal and mechanical properties of POSS-Cyanate ester/epoxy nanocomposites

A new cyanate ester functionalized polyhedral oligomeric silsesquioxane (POSS-Cy) monomer was prepared by reacting hydroxyl functionalized POSS-OH with cyanogen bromide (CNBr) in the presence of triethylamine (Et3N). The precursor POSS-OH and the corresponding cyanate ester POSS-Cy were characterized by Fourier transform infrared (FTIR), 1H and 13C nuclear magnetic resonance (13C-NMR) spectral techniques. Nanocomposites were prepared by reacting diglycidylether of bisphenol-A, POSS-Cy and 4,4’-diaminodiphenylmethane (DDM). The structure of the cross-linked networks was confirmed by FT-IR. The POSS particles formed clusters in some regions leading to phase separation as revealed by scanning electron microscopy (SEM) analysis. Dynamic mechanical analysis (DMA) shows that the glass transition temperature decreases from 161oC to 155oC when the POSS-Cy content was increased from 0% to 15%. But, the T10% of the epoxy resin (369oC) increased significantly (404°C) on incorporating 15% of POSS-Cy. The LOI values indicate that these blends have good flame-retardant properties.

Prevalence of diabetes and prediabetes (impaired fasting glucose and/or impaired glucose tolerance) in urban and rural India: phase I results of the Indian Council of Medical Research-INdia DIABetes (ICMR-INDIAB) study

AIMS/HYPOTHESIS

This study reports the results of the first phase of a national study to determine the prevalence of diabetes and prediabetes (impaired fasting glucose and/or impaired glucose tolerance) in India.

METHODS

A total of 363 primary sampling units (188 urban, 175 rural), in three states (Tamilnadu, Maharashtra and Jharkhand) and one union territory (Chandigarh) of India were sampled using a stratified multistage sampling design to survey individuals aged ≥ 20 years. The prevalence rates of diabetes and prediabetes were assessed by measurement of fasting and 2 h post glucose load capillary blood glucose.

RESULTS

Of the 16,607 individuals selected for the study, 14,277 (86%) participated, of whom 13,055 gave blood samples. The weighted prevalence of diabetes (both known and newly diagnosed) was 10.4% in Tamilnadu, 8.4% in Maharashtra, 5.3% in Jharkhand, and 13.6% in Chandigarh. The prevalences of prediabetes (impaired fasting glucose and/or impaired glucose tolerance) were 8.3%, 12.8%, 8.1% and 14.6% respectively. Multiple logistic regression analysis showed that age, male sex, family history of diabetes, urban residence, abdominal obesity, generalised obesity, hypertension and income status were significantly associated with diabetes. Significant risk factors for prediabetes were age, family history of diabetes, abdominal obesity, hypertension and income status.

CONCLUSIONS/INTERPRETATIONS

We estimate that, in 2011, Maharashtra will have 6 million individuals with diabetes and 9.2 million with prediabetes, Tamilnadu will have 4.8 million with diabetes and 3.9 million with prediabetes, Jharkhand will have 0.96 million with diabetes and 1.5 million with prediabetes, and Chandigarh will have 0.12 million with diabetes and 0.13 million with prediabetes. Projections for the whole of India would be 62.4 million people with diabetes and 77.2 million people with prediabetes.

Nutritional and sensory profile of two Indian rice varieties with different degrees of polishing

Traditional hand-pounded rice has been replaced today with highly polished white rice in the Asian Indian diets. The study aimed to evaluate the nutritional as well as the sensory differences between the brown (0% polish) and the rice milled to different degrees of polish (2.3, 4.4 and 8.0%). Bapatla and Uma (red pigmented) varieties in both raw and parboiled forms were used. The protein, fat, dietary fibre, γ-oryzanol, polyphenols, vitamin E, total antioxidant activity and free radical scavenging abilities of the brown rice decreased while the available carbohydrates increased with polishing. Sensory attributes of the cooked rice samples (whiteness, grain intactness, fluffiness, firmness, stickiness, chewiness and the cooked rice aroma) were evaluated by trained panelists. Scores for branny taste and chewiness decreased with polishing. On the whole, brown rice of both the varieties was readily accepted by the well-informed sensory trained panelists.

Glycaemic index of three Indian rice varieties

Three commonly consumed Indian rice varieties (Sona Masuri, Ponni and Surti Kolam) were tested for their glycaemic index (GI). Healthy volunteers were recruited and after an overnight fast were given a 50 g available carbohydrate portion of glucose (reference food) or different varieties of cooked rice (test foods) on separate occasions. The fasting as well as postprandial capillary blood glucose response was determined over 2 h, and the incremental area under the curve (IAUC) was calculated. The GI was calculated as the IAUC of the test food/IAUC of the reference food (glucose) × 100. The differences between the GI values for Sona Masuri (72.0 ± 4.5), Ponni (70.2 ± 3.6) and Surti Kolam (77.0 ± 4.0) rice varieties were non-significant (p = 0.606) and are all classified as high GI varieties of rice. There is an urgent need to study the GI of other commonly consumed rice varieties and to develop rice of a lower GI value.

Comparison of HPLC & spectrophotometric methods for estimation of antiretroviral drug content in pharmaceutical products

BACKGROUND & OBJECTIVES

Simple and reliable methods to estimate drugs in pharmaceutical products are needed. In most cases, antiretroviral drug estimations are performed using a HPLC method, requiring expensive equipment and trained technicians. A relatively simple and accurate method to estimate antiretroviral drugs in pharmaceutical preparations is by spectrophotometric method, which is cheap and simple to use as compared to HPLC. We undertook this study to standardise methods for estimation of nevirapine (NVP), lamivudine (3TC) and stavudine (d4T) in single tablets/capsules by HPLC and spectrophotometry and to compare the content of these drugs determined by both these methods.

METHODS

Twenty tablets/capsules of NVP, 3TC and d4T each were analysed for their drug content by HPLC and spectrophotometric methods. Suitably diluted drug solutions were run on HPLC fitted with a C18 column using UV detection at ambient temperature. The absorbance of the diluted drug solutions were read in a spectrophotometer at 300, 285 and 270 nm for NVP, 3TC and d4T respectively. Pure powders of the drugs were used to prepare calibration standards of known drug concentrations, which was set up with each assay.

RESULTS

The inter-day variation (%) of standards for NVP, 3TC and d4T ranged from 2.5 to 6.7, 2.1 to 7.7 and 6.2 to 7.7, respectively by HPLC. The corresponding values by spectrophotometric method were 2.7 to 4.7, 4.2 to 7.2 and 3.8 to 6.0. The per cent variation between the HPLC and spectrophotometric methods ranged from 0.45 to 4.49 per cent, 0 to 4.98 per cent and 0.35 to 8.73 per cent for NVP, 3TC and d4T,respectively.

CONCLUSIONS

The contents of NVP, 3TC and d4T in the tablets estimated by HPLC and spectrophotometric methods were similar, and the variation in the amount of these drugs estimated by HPLC and spectrophotometric methods was below 10 per cent. This suggests that the spectrophotometric method is as accurate as the HPLC method for estimation of NVP, 3TC and d4T in tablet/capsule. Hence laboratories that do not have HPLC equipment can also undertake these drug estimations using spectrophotometer.

Glycaemic index of common foods tested in the UK and India

The aim of this study was to ascertain whether international glycaemic index (GI) values, predominantly developed using peoples living in Europe, North America or Australia, are applicable to Asian Indians resident in their own country. Thirty-four Caucasian subjects were recruited in Oxford, UK and thirteen Asian Indian subjects in Chennai, India. Two types of sweet biscuits and three breakfast cereals were tested for glycaemic response in each group. Subjects were served equivalent available carbohydrate amounts (50 g) of test foods and a reference food (glucose), on separate occasions. Capillary blood glucose was measured from finger-prick samples in fasted subjects ( - 5 and 0 min) and at 15, 30, 45, 60, 90 and 120 min after starting to eat. For each test food, the incremental area under the curve (IAUC) and GI values were determined. Although the glycaemic response to the reference food was higher in Asian Indian subjects compared with UK Caucasian subjects (IAUC 219 mmol/min per litre v. 157 mmol/min per litre, respectively; P < 0.01), there was no significant difference in GI values of the five test foods between the two groups. This is the first study known to the authors to examine the role of ethnicity on GI when the subjects are resident in their own countries. The findings from this study have important implications for the use of the GI concept worldwide and support the application of international values to different ethnic groups. The higher glycaemic response to all foods in Asian Indians may represent another mechanism for increased diabetes susceptibility among Asian Indians.

Gene-Environment Interactions and the Diabetes Epidemic in India

The prevalence of diabetes is rising rapidly in all developing countries and India already has the largest number of people with diabetes. Evidence for the rising prevalence of diabetes in India comes from recent population-based studies such as the Chennai Urban Population Study (n = 1,262) and the Chennai Urban Rural Epidemiology Study (n = 26,001). These two studies revealed that the current age-standardized prevalence of diabetes in Chennai in adults >/=20 years of age is 14.3%, which is 70% higher than that seen in the year 1989 (8.3%). In the Chennai Urban Population Study, we observed that the higher-income group who consumed excess fat and calorie-rich food had an increased prevalence of diabetes compared to the lowerincome group. There was also a linear increase in the prevalence of diabetes with an increase in visible fat consumption. In addition, we observed that visible fat consumption and physical inactivity showed a cumulative effect on increasing the prevalence of diabetes. We carried out gene-diet interaction studies, which revealed that the adiponectin gene polymorphism (+10211T - G) contributed to insulin resistance and diabetes and this was exaggerated in those consuming diets with higher glycemic loads. These subjects also had an increased risk for hypoadiponectinemia. Similarly, the Ala54Thr polymorphism of the fatty acid-binding protein 2 gene showed a synergistic effect with a high glycemic load increasing the risk for hypertriglyceridemia. These studies indicate that gene-diet interactions could play a major role in increasing the risk for diabetes. However, given the imprecision in measuring dietary intake, very large sample sizes would be needed for meaningful conclusions to be drawn.

Reproducibility and validity of an interviewer-administered semi-quantitative food frequency questionnaire to assess dietary intake of urban adults in southern India

We report on the reproducibility and validity of a food frequency questionnaire (FFQ) developed for southern India. One hundred and two adult subjects aged > or =20 years drawn from the Chennai Urban Rural Epidemiology Study participated. The FFQ was developed based on local foods and habits, and was administered three times at 0, 6 and 12 month periods (called FFQ1, FFQ2 and FFQ3) to assess the reproducibility. To test the validity of the FFQ, multiple 24-h recalls collected at 2-monthly intervals for a period of 1 year and the estimated energy intake/basal metabolic rate (EI/BMR) ratio were used. The 'EpiNu' in-house food and nutrient database was used to compile dietary intakes, which were analyzed for statistical analysis. The intraclass correlation coefficient for all three FFQs ranged from 0.72 for carbohydrates to 0.45 for folate. The de-attenuated Pearson correlation for the energy adjusted nutrients between FFQ3 and 24-h recalls ranged from 0.73 for carbohydrates to 0.35 for calcium. Bland and Altman plots for energy intake between the two methods showed the limits of agreement ranged from 768 to -1358 calories/day (+/-2 standard deviations). Misclassification was low for most of the nutrients. Under-reporting of the energy intake (EI/BMR ratio<1.2) was higher in females than males. This FFQ appears to be a robust tool to measure dietary intakes in southern India.

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.

Atypical presentation of adult rubella

A 55 year old female presented with fever, skin rash and subconjunctival hemorrhage. She also developed hepatitis. Fever and skin rash lasted for more than three weeks. This patient was diagnosed to have rubella, highlighting the fact that rubella can present with atypical features like prolonged fever and rash, subconjunctival hemorrhage and hepatitis, especially in adults.

An unusual presentation of tropical pyomyositis

Tropical pyomyositis is a primary pyogenic infection of skeletal muscle, often caused by Staphylococcus aureus. The most common presentation of tropical pyomyositis is that of multiple acute abscesses with fever. Hepatitis is a rare manifestation of this disease. We report a case of tropical pyomyositis who presented with hepatic encephalopathy leading to initial diagnostic dilemma.

Efficacy and tolerability of Dianex in Type 2 diabetes mellitus: a non randomized, open label non-comparative study

OBJECTIVE AND STUDY DESIGN

A nonrandomized open labeled clinical trial to evaluate the efficacy and tolerability of Dianex (a poly herbal formulation developed by Apex Laboratories [PVT] Chennai, Tamil Nadu, India) in type 2 diabetes mellitus was carried out during a 6-month period.

SETTING/LOCATION

This study was conducted in TMA Pai Hospital, Udupi, South India.

SUBJECTS

A total of 40 patients were recruited for this study. Three patients dropped out of the study leaving a total of 37 patients (11 for monotherapy and 26 for add on therapy).

OUTCOME MEASURES

Eighteen (18) clinical variables were investigated, including liver enzymes, kidney function tests, hematologic parameters, blood glucose, and insulin and lipid profiles.

RESULTS

at the end of 12 weeks it was found that there was a significant decrease in the level of glycated hemoglobin, fasting plasma insulin level, insulin resistance, and systolic and diastolic blood pressure. At the end of 24 weeks results were similar to those at 12 weeks. Dianex did not alter the liver function tests, hematological parameters, or kidney function tests.

CONCLUSION

In this preliminary study, Dainex is found to be an effective adjuvant drug with either oral antidiabetic agents or insulin that can be used in the control of blood sugars in diabetic patients. Dianex is a safe drug that does not cause any clinical, hematological or biochemical alteration in major organ systems.

A simple simulation methodology for estimation of dehydration energies and surface potentials of concentrated NaCl solutions

A novel simulation procedure for estimating the dehydration energies of NaCl solutions spanning a wide range of concentrations, which incorporates ionic and molecular sizes, ion-pair formation, etc., is proposed on geometric and phenomenological considerations. The extent of dehydration during each movement of the hydrated molecule is evaluated using the expected and actual displacement of the species and mean nearest-neighbor distances. The interdependence between the size of the simulation box, number of molecules, and electrolyte concentration is pointed out.