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Biomedical subjects

S K Roy

Publications and source records attributed to S K Roy.

At least 19 recordsLinked to original sources
PubMed2006

Validity of an alternative anthropometric trait as cardiovascular diseases risk factor: example from individuals with traumatic lower extremity amputation.

BACKGROUND: Published studies reveal that individuals with lower extremity amputation are vulnerable to cardiovascular diseases (CVD) because of poor physical activity level. Many cardiovascular risk assessment studies have utilized anthropometric traits (primarily body mass index and waist circumference) as cardiovascular risk factor. However, some studies emphasized the technical limitations of measuring waist circumference for studying cardiovascular risk, and so it is difficult to obtain correct measurement from the individuals with lower extremity amputation. OBJECTIVES: The objectives of the present article are to study the prevalence of CVD risk factors among the individuals with traumatic lower extremity amputation and to test the validity of upper arm circumference (UAC) as an alternative anthropometric measurement for screening the CVD risk condition. SUBJECTS AND SETTING: Anthropometric data and other cardiovascular traits data have been collected from unilateral traumatic lower extremity amputated adult males (n = 85) residing in Calcutta and adjoining areas. RESULTS: Results show higher prevalence of cardiovascular risk factor among individuals with above-knee amputation than below-knee amputation. The receiver operating characteristics curve analysis shows significant ability of upper arm circumference to diagnose cardiovascular risk condition. The cutoff value of UAC > 26.6 cm show maximum sensitivity and specificity for the diagnosis of cardiovascular risk condition. Although, binomial tests for equality of proportion does not show any significant difference, however, agreement statistics reveal better diagnostic ability of cutoff value of UAC than the existing cutoff value of waist circumference. CONCLUSIONS: Therefore, UAC provides a better assessment of cardiovascular risk condition than does waist circumference especially for individuals with lower extremity amputation. SPONSORSHIP: Indian Statistical Institute, Kolkata.

Adult↗
PubMed2006

Impact of zinc deficiency on vibrio cholerae enterotoxin-stimulated water and electrolyte transport in animal model.

The effect of zinc deficiency on the function of the intestine to absorb water and electrolytes was studied in animal models, stimulated by Vibrio cholerae enterotoxin. Sprague-Dawley rats, used in the study, were divided into four groups: Zinc-deficient, ad libitum zinc-fed control, zinc weight-matched control, and zinc-deficient acutely-repleted. 14C-labelled polyethylene glycol solution was used for measuring the absorption capacity of the small intestine. Significantly lower absorption of water and sodium per cm of the intestine was observed in the zinc-deficient animals compared to the ad libitum zinc-fed control animals (p < 0.01). An improved absorption capacity was equally observed in the zinc-deficient acutely-repleted animals and ad libitum zinc-fed control group. The zinc-deficient animals showed four times greater cholera toxin-induced net secretions of water and sodium compared to the ad libitum zinc-fed group (p < 0.01), while a 40% reduction was observed in the zinc-deficient acutely-repleted group. The results suggest that zinc deficiency is associated with reduced absorption of water and electrolytes and increased secretion of the same stimulated by cholera toxin.

Animals↗
PubMed2005

Redox control of K+ channel remodeling in rat ventricle.

Electrical remodeling of the diseased heart contributes to contractile dysfunction and arrhythmias, and is characterized by down-regulation of K(+) channels that control action potential morphology. We have recently shown that remodeling of K(+) channels underlying the transient outward current (I(to)) involves a shift in cell redox balance that is reflected by a depletion of the endogenous redox buffer, glutathione (GSH). This study used a pharmacological model to further examine the role of redox-mediated mechanisms in regulating cardiac K(+) currents. Inhibition of major redox pathways was elicited in normal rats by daily injections of 1,3-bis-(2-chloroethyl)-1-nitrosourea (BCNU), an inhibitor of thioredoxin and glutathione reductases, and buthionine sulfoximine (BSO), a blocker of GSH synthesis. Fluorescence microscopy studies showed that [GSH] in isolated ventricular myocytes was decreased ~50% from control after 3 days of BCNU/BSO treatment (P<0.05), consistent with a shift in cell redox state. In voltage-clamp experiments, maximum I(to) density was decreased 33% from control in left ventricular myocytes from BCNU/BSO-treated rats (P<0.05), while the inward rectifier and steady state outward currents were not significantly altered. Decreased I(to) density correlated with significant decreases in Kv4.2 mRNA and proteins levels of Kv4.2 and Kv1.4. Down-regulation of I(to) in myocytes from BCNU/BSO rats was reversed in vitro by exogenous GSH or N-acetylcysteine, a GSH precursor and antioxidant. I(to) density and [GSH] were also up-regulated by receptor tyrosine kinase activation with insulin or a tyrosine phosphatase inhibitor. The effect of these activators on I(to) was blocked by inhibitors of PI 3-kinase, MEK and p38 MAP kinases. These data suggest that expression of cardiac I(to) channels is regulated by endogenous oxidoreductase systems and that receptor tyrosine kinase signaling functionally impacts K(+) channel remodeling through its control of cell redox state.

Animals↗
PubMed2005

Chromosome breakage is primarily responsible for the micronuclei induced by 1,4-dioxane in the bone marrow and liver of young CD-1 mice.

1,4-Dioxane, a widely used industrial chemical and rodent hepatocarcinogen, has produced mixed, largely negative results in the mouse erythrocyte micronucleus assay. In contrast, a recent report has indicated that 1,4-dioxane induces micronuclei in mouse hepatocytes following in vivo treatment. The objective of this study was to confirm these earlier results and identify the origin of the induced micronuclei. Following an initial range-finding study, mice were administered 1,4-dioxane by gavage at doses ranging from 1500 to 3500 mg/kg. The test animals were also implanted with BrdU-releasing osmotic pumps to allow cell proliferation to be measured in the liver and to increase the sensitivity of the hepatocyte assay. Upon sacrifice, the frequency of micronuclei in the bone marrow erythrocytes and in the proliferating BrdU-labeled hepatocytes was determined. Significant dose-related increases in micronuclei were seen in both the liver and the bone-marrow with significant increases being detected at all the tested doses in the bone marrow and at the 2500 and 3500 mg/kg doses in the liver. Using CREST staining or pancentromeric FISH to determine the origin of the induced micronuclei, it was determined that 80-90% of the micronuclei in both tissues originated from chromosomal breakage. Small increases in centromere-containing micronuclei were also seen in the hepatocytes. Decreases in hepatocyte proliferation as well as in the ratio of bone marrow PCE:NCE were also observed. Based on these results, we conclude that at high doses: (i) dioxane exerts genotoxic effects in both the mouse bone marrow and liver; (ii) the induced micronuclei are formed primarily from chromosomal breakage; and (iii) dioxane can interfere with cell proliferation in both the liver and bone marrow.

Animals↗
PubMed2005

Plasmodium falciparum: genetic diversity of C-terminal region of MSP-1 in isolates from Indian sub-continent.

Malaria parasites exhibit sequence diversity for a number of stage specific antigens. Several studies have proved that merozoite surface protein-1 (MSP-1) is an effective target eliciting a protective immune response. The MSP-1(42) region comprising two EGF-like domains is involved in generating protective immune response in humans and other experimental animals. Searching for point mutations in this region is essential in view of vaccine development. We have investigated the sequence variations in Plasmodium falciparum MSP-1 carboxy terminal region in field isolates from different regions in India. Our study reveals the presence of eight variant types of MSP-1(19) in the Indian sub-continent, which comprise of E-TSR-L, Q-TSR-L, E-TSG-L, Q-KNG-L, Q-KNG-F, E-KNG-L, E-KNG-F, and E-KYG-F. The last named allele is a novel variant being reported for the first time.

Alleles↗
PubMed2005

Effects of a food supplementation program on the nutritional status of pregnant women in Bangladesh.

BACKGROUND: The Government of Bangladesh implemented a comprehensive nutrition intervention in 1997 to reduce the rates of malnutrition among women and children. The pilot program, the Bangladesh Integrated Nutrition Program (BINP), adopted a multisectoral approach targeting women and children through food supplementation, home gardening, and health and nutrition education. OBJECTIVE: This paper estimates the effectiveness of BINP's food supplementation and nutrition education on the nutritional status of pregnant women. Methods. Three effectiveness measures were considered: target efficiency, improvements in the nutritional status of beneficiaries, and the persistence of nutritional effects. To isolate the effects of the intervention, the nutritional status of participants and nonparticipants was compared after controlling for various demographic and socioeconomic characteristics. Data were collected in 2000 from a random sample of 3262 households in a BINP intervention area. RESULTS: Thirty-nine percent of pregnant women were correctly targeted by the program's food supplementation activities. The nutrition program reduced the prevalence of thinness among participant pregnant women by about 3 percentage points per month of enrollment. The prevalence of thinness among program graduates was 62%, which was much higher than that of the matched (nonparticipant) group (35%). This finding is perplexing but it may simply imply that those who enrolled at the initial phase of the project were severely underweight and they fell back to their original status within a short period of time. CONCLUSIONS: The nutrition program was intended to improve the nutritional status of women in the longer run through the provision of nutrition education during the food supplementation phase. The prevalence of thinness or severe underweight in women who exited the program after completion of the enrollment period was found to be much higher than in women of similar age and socioeconomic status in the community. This apparent lack of persistence of program benefits requires careful re-evaluation of alternative mechanisms for improving the long-term nutritional status of women.

Adolescent↗
PubMed2005

Risk factors for mortality due to shigellosis: a case-control study among severely-malnourished children in Bangladesh.

To determine the risk factors for death of severely-malnourished Bangladeshi children with shigellosis, a case-control study was conducted at the Clinical Research and Service Centre of ICDDR,B: Centre for Health and Population Research in Dhaka, Bangladesh. One hundred severely-malnourished children (weight-for-age <60% of median of the National Center for Health Statistics), with a positive stool culture for Shigella dysenteriae type 1 or S. flexneri, who died during hospitalization, were compared with another 100 similar children (weight-for-age <60% and with S. dysenteriae type 1 or S. flexneri-associated infection) discharged alive. Children aged less than four years were admitted during December 1993-January 1999. The median age of the cases who died or recovered was 9 months and 12 months respectively. Bronchopneumonia, abdominal distension, absent or sluggish bowel sound, clinical anaemia, altered consciousness, hypothermia, clinical sepsis, low or imperceptible pulse, dehydration, hypoglycaemia, high creatinine, and hyperkalaemia were all significantly more frequent in cases than in controls. In multivariate regression analysis, altered consciousness (odds ratio [OR]=2.6, 95% confidence interval [CI] 1.0-6.8), hypoglycaemia (blood glucose <3 mmol/L (OR=7.8, 95% CI 2.9-19.6), hypothermia (temperature <36 degrees C) (OR=5.7, 95% CI 1.5-22.1), and bronchopneumonia (OR=2.5, 95% CI 1.1-5.5) were identified as significant risk factors for mortality. Severely-malnourished children with shigellosis having hypoglycaemia, hypothermia, altered consciousness and/or bronchopneumonia were at high risk of death. Based on the findings, the study recommends that early diagnosis of shigellosis in severely-malnourished children and assertive therapy for proper management to prevent development of hypothermia, hypoglycaemia, bronchopneumonia, or altered consciousness and its immediate treatment are likely to reduce Shigella-related mortality in severely-malnourished children.

Bangladesh↗
PubMed2005

Intensive nutrition education with or without supplementary feeding improves the nutritional status of moderately-malnourished children in Bangladesh.

This prospective randomized trial was carried out to test the efficacy of a specific intervention for reducing the extent of their malnutrition and to change behaviour of mothers relating to child-feeding practices, care-giving, and health-seeking practices under the Bangladesh Integrated Nutrition Project (BINP). The study was conducted in rural Bangladesh among 282 moderately-malnourished (weight-for-age between 61% and 75% of median of the National Center for Health Statistics standard) children aged 6-24 months. Mothers of the first intervention group received intensive nutrition education (INE group) twice a week for three months. The second intervention group received the same nutrition education, and their children received additional supplementary feeding (INE+SF group). The comparison group received nutrition education from the community nutrition promoters twice a month according to the standard routine service of BINP. The children were observed for a further six months. After three months of interventions, a significantly higher proportion of children in the INE and INE+SF groups improved (37% and 47% respectively) from moderate to mild or normal nutrition compared to the comparison group (18%) (p < 0.001). At the end of six months of observation, the nutritional status of children in the intervention groups improved further from moderate to mild or normal nutrition compared to the comparison group (59% and 86% vs 30%, p < 0.0001). As the intensive nutrition education and supplementation given were highly effective, more children improved from moderate malnutrition to mild or normal nutritional status despite a higher incidence of morbidity. The frequency of child feeding and home-based complementary feeding improved significantly (p < 0.001) in both the intervention groups after three months of interventions and six months of observation. Body-weight gain was positively associated with age, length-for-age, weight-for-length, frequency of feeding of khichuri, egg, and potato (p < 0.05). Ability of mothers to identify malnutrition improved from 15% to 99% in the INE group and from 15% to 100% in the INE+SF group, but reduced from 24% to 21% in the comparison group. Use of separate feed pots, frequency of feeding, and cooking of additional complementary feeds improved significantly in the INE and INE+SF groups compared to the comparison group after three months of interventions and six months of observation. It can be concluded from the findings of the study that intensive nutrition education significantly improves the status of moderately-malnourished children with or without supplementary feeding.

Analysis of Variance↗
PubMed2004

Influence of storage environment, surface coating, and individual shrink wrapping on quality assurance of guava (Psidium guajava) fruits.

Guava (Psidium guajava) fruits of cv. L-49 with individual shrink wrapping using 9 micro LLDPE film could be successfully stored up to 12 days at ambient and 18 days in evaporative cool chamber with negligible loss in vitamin C content. The untreated fruits lose 25-30% of ascorbic acid within 1 week after harvest. Delay in senescence and metabolic activities as supported by less changes in soluble solids, sugars, acidity, respiration, and ethylene evaluation rate was also observed in individual shrink wrapped fruits in cool chamber. The spoilage of fruits by Fusarium rots was significantly less in cool chamber in individually shrink wrapped fruits followed by Sta-fresh treatment. Sta-fresh was more effective in cool chamber than ambient. Individually stored wrapped fruits scored a better value of sensory score than Sta-fresh under both the storage condition.

Antioxidants↗
PubMed2003

Influence of an organic mulching on fertilizer nitrogen use efficiency and herb and essential oil yields in geranium (Pelargonium graveolens).

In a field study, conducted at Lucknow ( 26.5 degrees N, 80.5 degrees E and 120 m altitude), India for two years (1996-1997 and 1997-1998), eight treatment combinations of two variables of organic mulch (paddy straw at 7 t/ha and no mulch) and four levels of fertilizer nitrogen (0, 80, 160 and 240 kg/ha) were examined to observe the effect of organic mulching on N-use efficiency and essential oil yield in a multi-harvested geranium crop. Results revealed that application of paddy straw mulch increased the herb and essential oil yields in geranium by 23% and 27%, respectively, over the unmulched control at planted crop harvest. Corresponding values at regenerated crop harvest were 18.7% and 19.2%. A significant response to N was observed with 160 kgN/ha in mulched plot over the same level of N in the unmulched plot. Using paddy straw mulch, nitrogen uptake by plants of planted and regenerated crops was increased by 33% and 28.4%, respectively, over the unmulched control. Apparent N recoveries by planted and regenerated crops were estimated to be 33.7% and 22.7% for the unmulched control, as against 40% and 29.2% with paddy straw mulch at 160 kgN/ha. The quality of essential oil of geranium in terms of its major constituents, citronellol and geraniol, was not affected by the use of organic mulching and nitrogen fertilization and these constituents were found to be of a standard acceptable in international trade. It was concluded from this study that use of an organic mulch with 160 kgN/ha proved better in terms of economising 80 kgN/ha to produce an economic yield of 96.1 kg geranium oil from two harvests under subtropical conditions of the north Indian plains. At 160 kgN/ha, paddy straw mulch application permitted the geranium crop to produce 18.4 kg/ha more oil which gave an additional return of Rs. 53,600/ha than that of unmulched control. Paddy straw mulch and nitrogen fertilization had no adverse effect on the quality of essential oil of geranium.

Agriculture↗
PubMed2003

Environmental pollution in rural areas of Orissa state due to industrial emissions--with special reference to fluoride.

Angul - Talcher belt in Central Orissa, having a number of industries contributing to a great extent to deteriorate the air quality of the surrounding villages. Previous reports showed higher SPM, SO2, NO, levels in air and prevalence of respiratory illness, skin and teeth disorders among village population. Higher ground water fluoride, urine and serum fluoride among the cattle were also reported in some villages. Present study reports SPM, SO2, NOx and Fluorides (gaseous and Particulate) in ambient air around aluminium smelter during February and August 1996. High volume sampling technique for SPM and the standard colorimetric methods (BIS) for analyses of SO2 and NOx were adopted. Fluoride in air and water were estimated by standard fluoride ion selective electrode method. Higher SPM, SO2 and NOx values than prescribed CPCB standard were obtained in February. Gaseous fluoride in village air were varied between, 1.66 - 7.64 mg/m3 in February and 1.11 - 22.75 mg/m3 in August, whereas particulate fluoride ranged between, 0.054 - 19.61 mg/m3. Water sources of the villages near the smelter showed fluoride values above permissible limit. The study indicated higher fluoride pollution in air and water of the surrounding villages.

Air Movements↗
PubMed2002

Impact of lactational performance on bone mineral density in marginally-nourished Bangladeshi women.

This cross-sectional study, carried out during July 1997-June 1998, evaluated the effects of prolonged breast-feeding and lactational amenorrhoea on bone mineral density (BMD) in 400 marginally-nourished Bangladeshi women aged 20-81 years. A bone densitometer was used for measuring BMD in the distal and ultra-distal end of radius and ulna. The results showed that the women who breastfed for 60 months or less had a higher mean BMD compared to those who breastfed for 61-120 months and for over 120 months. There was a significantly higher BMD in the women who had a shorter duration of lactational amenorrhoea compared to those having a longer duration of lactational amenorrhoea. BMD was significantly and negatively correlated with total duration of lactational amenorrhoea (slope -0.024, p<0.05) after controlling for parity, physical workload, and total duration of breast-feeding. The study concluded that there was a negative correlation between longer duration of breast-feeding and BMD, but it was not found when other factors were controlled in multivariate analysis. The duration of lactational amenorrhoea, which is a proxy indicator of breast-feeding, showed a negative correlation with BMD. It is recommended that all lactating women be given diet with adequate calcium to support breast-feeding for maintaining good nutrition of their bones.

Adult↗
PubMed2002

Perceptions of mothers and use of breastmilk substitutes in Dhaka, Bangladesh.

To explore the actual practices and perceptions of giving breastmilk and breastmilk substitutes (BMS), this cross-sectional study was conducted among 326 mothers of low (income/month < Tk 4,000, n = 163) and middle (income/month > Tk 4,000, n = 163) socioeconomic status (SES) with infants aged 6-12 months in Dhaka city during February-April 2001. Qualitative data on perceptions of mothers on appropriate breast-feeding practices were also documented through focus-group discussions (FGDs). The prevalence of exclusive breast-feeding was low in both the socioeconomic groups but was comparatively higher among the mothers of middle SES (3.1% vs 12.3%, p < 0.001), although predominant breast-feeding was high among the mothers of low SES. In addition, the use of BMS was higher among the mothers of middle SES than among the mothers of low SES (55.8% vs. 43.5%, p < 0.001). The majority (62.3%) of the mothers mentioned insufficiency of breastmilk as the main reason for introducing BMS. Perception on appropriate feeding practices was also significantly different between the two groups. Approximately, 90% of the mothers of low SES could not differentiate between infant formula and milk powder compared to 70% of the mothers of middle SES (p < 0.001). The findings of FGDs revealed that some middle-class mothers thought that infant formula was the best food for their infants. Programmes to impart proper knowledge on breast-feeding practices should be strengthened.

Adult↗
PubMed2001

Production of safe therapeutic feeds from contaminated water supplies.

We have assessed the effectiveness of using an osmotic sachet for safe rehydration of therapeutic milk from contaminated water supplies in a poor urban area of Bangladesh. 35 women were given sachets to hydrate in their homes and comparison of the hydration water and the reconstituted milk showed that the high bacterial contamination reported in the domestic water supply was removed by use of the sachet. The mean rehydration time was 4.5 h (range 3.4-5.5). This rehydration method could have a role in the preparation of therapeutic feeds where microbiological contamination of the environment is a serious problem and availability of adequate water is not a limiting factor.

Adult↗
PubMed2001

Effect of a rigid nonpolar solute on the splay, bend elastic constants, and on rotational viscosity coefficient of 4,4'-n-octyl-cyanobiphenyl.

The effect of a rigid nonpolar nonmesogenic solute "biphenyl," that is, C6H5-C6H5 on the splay and bend elastic constants and on the rotational viscosity coefficient of 4,4'-n-octyl-cyanobiphenyl is reported. The experiments involve the measurement of the voltage dependence of the capacitance of a cell filled with the mixture. Anomalous behavior of both K11 and Deltaepsilon near the N-S(A) transition have been observed.

Journal Article↗
PubMed2001

ERK1 and ERK2 activate CCAAAT/enhancer-binding protein-beta-dependent gene transcription in response to interferon-gamma.

Interferons (IFNs) regulate the expression of a number of cellular genes by activating the JAK-STAT pathway. We have recently discovered that CCAAAT/enhancer-binding protein-beta (C/EBP-beta) induces gene transcription through a novel IFN response element called the gamma-IFN-activated transcriptional element (Roy, S. K., Wachira, S. J., Weihua, X., Hu, J., and Kalvakolanu, D. V. (2000) J. Biol. Chem. 275, 12626-12632. Here, we describe a new IFN-gamma-stimulated pathway that operates C/EBP-beta-regulated gene expression independent of JAK1. We show that ERKs are activated by IFN-gamma to stimulate C/EBP-beta-dependent expression. Sustained ERK activation directly correlated with C/EBP-beta-dependent gene expression in response to IFN-gamma. Mutant MKK1, its inhibitors, and mutant ERK suppressed IFN-gamma-stimulated gene induction through the gamma-IFN-activated transcriptional element. Ras and Raf activation was not required for this process. Furthermore, Raf-1 phosphorylation negatively correlated with its activity. Interestingly, C/EBP-beta-induced gene expression required STAT1, but not JAK1. A C/EBP-beta mutant lacking the ERK phosphorylation site failed to promote IFN-stimulated gene expression. Thus, our data link C/EBP-beta to IFN-gamma signaling through ERKs.

Animals↗
PubMed2001

Retention of quality characteristics of dehydrated green leaves during storage.

Green leafy vegetables are the most underexploited class of vegetables despite high nutritional value. Reports on nutritional composition and storage of some of the fresh leaves are available but the storage behavior of dehydrated leaves apparently has not been studied. Therefore, in the present study, two green leafy vegetables, savoy beets (Beta vulgaris var. bengalensis) and fenugreek (Trigonella foenum graecum) were dehydrated in a low temperature drier and stored for 9 months under ambient and cold stored conditions after packaging in single or double layers of high density polyethylene film (200 gauge). The quality was determined on the basis of retention of beta-carotene, ascorbic acid and chlorophyll, and the extent of browning during storage. Retention of these quality characteristics depended on the crop and storage conditions. Double packed and cold stored samples of fenugreek retained 67% beta-carotene, whereas savoy beet leaves retained only 57% of the initial beta-carotene under similar conditions. Similarly, higher retention of ascorbic acid and chlorophyll, and lower browning was observed in double packed, cold stored samples. Results indicated the efficacy of double packed and cold stored samples over other combinations.

Ascorbic Acid↗