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A Vyas

Publications and source records attributed to A Vyas.

18 recordsLinked to original sources
PubMed2006

Prolonged behavioral stress enhances synaptic connectivity in the basolateral amygdala.

Recently identified cellular and molecular correlates of stress-induced plasticity suggest a putative link between neuronal remodeling in the amygdala and the development of anxiety-like behavior. Rodent models of immobilization stress, applied for 10 consecutive days, have been reported to enhance anxiety, and also cause dendritic elongation and spine formation in the basolateral amygdala (BLA). Paradoxically, longer exposure to stress, which is also anxiogenic, fails to affect key molecular markers of neuronal remodeling in the BLA. This has raised the possibility of homeostatic mechanisms being triggered by more prolonged stress that could potentially dampen the morphological effects of stress in the BLA. Therefore, we examined the cellular and behavioral impact of increasing the duration of stress in rats. We find that prolonged immobilization stress (PIS), spanning 21 days, caused significant enhancement in dendritic arborization of spiny BLA neurons. Spine density was also enhanced along these elongated dendrites in response to PIS. Finally, this striking increase in synaptic connectivity was accompanied by enhanced anxiety-like behavior in the elevated plus-maze. Thus, we did not detect any obvious morphological correlate of adaptive changes within the BLA that may have been activated by prolonged and repeated application of the same stressor for 21 days. These findings add to accumulating evidence that structural encoding of aversive experiences, through enhanced availability of postsynaptic dendritic surface and synaptic inputs on principal neurons of the BLA, may contribute to the affective symptoms of stress disorders.

Amygdala↗
PubMed2005

Marked differences in the IGF system that are associated with migration in comparable populations of Gujaratis living in Sandwell, UK, and Gujarat, India.

AIMS/HYPOTHESES: We previously reported independent links between the IGF system and the development of impaired glucose tolerance and cardiovascular risk. This study tests the hypothesis that the lifestyle change which accompanies population migration, with attendant increases in cardiovascular risk, is reflected by changes in the IGF system. MATERIALS AND METHODS: We compared a specific Gujarati community in Sandwell, UK (n=205), with people still resident in the same villages of origin near Navsari, India (n=246). We performed anthropometry and measured fasting plasma insulin, IGF-I, insulin-like growth factor binding protein (IGFBP)-1 and IGFBP-3. RESULTS: Daily calorie intake, BMI and WHR were significantly higher in UK Gujaratis than in Indian Gujaratis. IGFBP-1 was significantly lower in UK migrants (mean 29.5 [95% CI 25.9-33.0] vs 56.5 [50.6-62.5] microg/l; F=48.4, p<0.001). Conversely, fasting insulin, IGFBP-3 and IGF-I were all higher in UK Gujaratis (mean IGF-I 145.9 [138.1-153.6]ng/ml in UK Gujaratis and 100.9 [94.6-107.3] ng/ml in Navsari Gujaratis; F=76.6, p<0.001). These differences were still apparent when adjustment was made for BMI by location for IGF-I (F=57.4, p<0.001) and IGFBP-3 (F=5.7, p=0.02), but were no longer apparent for IGFBP-1 and insulin. At the population level, the decrease in IGFBP-1 for a given increase in insulin was significantly smaller in UK Gujaratis, suggesting greater hepatic insulin resistance in this group. CONCLUSIONS/INTERPRETATION: Environmental factors have profound effects on circulating IGF system components and on the relationship between IGFBP-1, IGF-I and related metabolic variables. This may have long-term implications for the development of worsening glucose tolerance and cardiovascular disease.

Blood Glucose↗
PubMed2005

Impact of migration on coronary heart disease risk factors: comparison of Gujaratis in Britain and their contemporaries in villages of origin in India.

The causes of the excess coronary heart disease (CHD) risk in South Asian migrants from the Indian subcontinent remain unclear. Comparisons of CHD risk factors amongst South Asian migrants living in Britain with those of the general UK population provide only a partial explanation. We compared Gujaratis in Britain with similar, non-migrant Gujaratis in India, to test the hypothesis that differences in CHD risk factors associated with migration would be more informative. Randomly sampled Gujaratis aged 25-79 years living in Sandwell (n = 242) were compared with age-, gender- and caste-matched contemporaries remaining in their villages of origin in Navsari, India (n = 295). Lifestyle indices, food intake and physical activity, were assessed with standardised questionnaires and energy expenditure and metabolic parameters measured. British Gujaratis had higher, mean body mass indices by 6 (4.5-7.4) kg/m(2) mean (95% CI), and greater dietary energy intake, fat intake, blood pressure, fasting serum cholesterol, apolipoprotein B, triglycerides, non-esterified fatty acid (NEFA) and C-reative protein concentrations than Gujaratis in India. Dietary folate and serum folate and Vitamin B(12) were lower and plasma homocysteine was higher in India. Smoking was less prevalent and high-density lipoprotein cholesterol tended to be higher in Britain. Diabetes prevalence was high in both populations and impaired fasting or 2 h post-glucose challenge plasma glucose was even more prevalent in Gujarat. In India, however, where insulin secretion and NEFA were lower diabetes and impaired glucose tolerance were less frequently accompanied by excess metabolic CVD risk factors. In conclusion, exposure to increased fat intake and obesity related to migration is likely to explain the disproportionate combination of established and emerging CHD risk factors prevalent in Gujaratis in Britain. Strategies to improve nutrition and to identify and treat cardiovascular risk factors such as dyslipidaemia and hypertension are urgently required.

Adult↗
PubMed2005

Dietary intake and the insulin-like growth factor system: effects of migration in two related populations in India and Britain with markedly different dietary intake.

BACKGROUND: The insulin-like growth factor (IGF) system is implicated in the pathogenesis of diabetes and cardiovascular disease. OBJECTIVE: We report the effects of total energy intake on the IGF system in two populations with markedly different dietary macronutrient intake and cardiovascular event rate. DESIGN, SUBJECTS AND SETTING: Dietary macronutrient intake was measured in a specific Gujarati migrant community in Sandwell, UK (n=205) compared with people still resident in the same villages of origin in India (n=246). Fasting IGF-I, IGF-binding protein (IGFBP)-1 and IGFBP-3, insulin and glucose (0 and 2-hour) were measured. RESULTS: Total energy and total fat intake were higher in UK migrants, as were IGFBP-3 and IGF-I (mean (95% confidence interval): 145.9 (138.1-153.6) vs. 100.9 (94.6-107.3) ng ml(-1); F=76.6, P<0.001). IGFBP-1 was lower in UK migrants (29.5 (25.9-33.0) vs. 56.5 (50.6-62.5) microg l(-1); F=48.4, P<0.001). At both sites, IGF-I correlated positively with total energy (Spearman's rho=0.45, P<0.001) and total fat (rho=0.44, P<0.001) as did IGFBP-3 with total energy (rho=0.21, P<0.05) and fat (rho=0.26, P<0.001). Conversely, in Indian Gujaratis, IGFBP-1 fell with increasing total energy (rho=-0.27, P<0.001) and fat intake (rho=-0.26, P<0.01) but not in UK Gujaratis. Multiple linear regression modelling showed that increasing quartiles of fat intake were associated with higher IGF-I (beta=0.42, P=0.007) independent of age, body mass index, plasma insulin, fatty acids and 2-hour glucose. CONCLUSION: In these genetically similar groups, migration to the UK and adoption of a different diet is associated with marked changes in the IGF system, suggesting that environmental factors profoundly modulate serum concentrations and actions of IGFs.

Blood Glucose↗
PubMed2004

Dietary advice for treatment of type 2 diabetes mellitus in adults.

BACKGROUND: While initial dietary management immediately after formal diagnosis is an 'accepted' cornerstone of treatment of type 2 diabetes mellitus, a formal and systematic overview of its efficacy and method of delivery is not currently available. OBJECTIVES: To assess the effect of type and frequency of different types of dietary advice to all adults with type 2 diabetes on weight, measures of diabetic control, morbidity, total mortality and quality of life. SEARCH STRATEGY: We carried out a comprehensive search of The Cochrane Library (The Cochrane Library Issue 3, 2003), MEDLINE (1966 to October Week 1, 2003), EMBASE (1980 to Week 40, 2003), CINAHL (1982 to October Week 1, 2003), AMED (1985 to October 2003), bibliographies and contacted relevant experts. SELECTION CRITERIA: All randomised controlled trials, of six months or longer, in which dietary advice was the main intervention in adults with type 2 diabetes mellitus. DATA COLLECTION AND ANALYSIS: The lead investigator performed all data extraction and quality scoring with duplication being carried out by one of the other six investigators independently with discrepancies resolved by discussion and consensus. Authors were contacted for missing data. For continuous outcomes, endpoint data were preferred to change data. MAIN RESULTS: Thirty-six articles reporting a total of eighteen trials following 1467 participants were included. Dietary approaches assessed in this review were low-fat/high-carbohydrate diets, high-fat/low-carbohydrate diets, low-calorie (1000 kcal per day) and very-low-calorie (500 kcal per day) diets and modified fat diets. Two trials compared the American Diabetes Association exchange diet with a standard reduced fat diet and five studies assessed low-fat diets versus moderate fat or low-carbohydrate diets. Two studies assessed the effect of a very-low-calorie diet versus a low-calorie diet. Six studies compared dietary advice with dietary advice plus exercise and three other studies assessed dietary advice versus dietary advice plus behavioural approaches. The studies all measured weight and measures of glycaemic control although not all studies reported these in the articles published. Other outcomes which were measured in these studies included mortality, blood pressure, serum cholesterol (including LDL and HDL cholesterol), serum triglycerides, maximal exercise capacity and compliance. The results suggest that adoption of regular exercise is a good way to promote better glycaemic control in type 2 diabetic patients, however all of these studies were at high risk of bias. REVIEWERS' CONCLUSIONS: There are no high quality data on the efficacy of the dietary treatment of type 2 diabetes, however the data available indicate that the adoption of exercise appears to improve glycated haemoglobin at six and twelve months in people with type 2 diabetes. There is an urgent need for well-designed studies which examine a range of interventions, at various points during follow-up, although there is a promising study currently underway.

Adult↗
PubMed2004

Dietary advice for treatment of type 2 diabetes mellitus in adults.

BACKGROUND: While initial dietary management immediately after formal diagnosis is an 'accepted' cornerstone of treatment of type 2 diabetes mellitus, a formal and systematic overview of its efficacy and method of delivery is not currently available. OBJECTIVES: To assess the effect of type and frequency of different types of dietary advice to all adults with type 2 diabetes on weight, measures of diabetic control, morbidity, total mortality and quality of life. SEARCH STRATEGY: We carried out a comprehensive search of The Cochrane Library (The Cochrane Library Issue 3, 2003), MEDLINE (1966 to October Week 1, 2003), EMBASE (1980 to Week 40, 2003), CINAHL (1982 to October Week 1, 2003), AMED (1985 to October 2003), bibliographies and contacted relevant experts. SELECTION CRITERIA: All randomised controlled trials, of six months or longer, in which dietary advice was the main intervention in adults with type 2 diabetes mellitus. DATA COLLECTION AND ANALYSIS: The lead investigator performed all data extraction and quality scoring with duplication being carried out by one of the other six investigators independently with discrepancies resolved by discussion and consensus. Authors were contacted for missing data. For continuous outcomes, endpoint data were preferred to change data. MAIN RESULTS: Thirty-six articles reporting a total of eighteen trials following 1467 participants were included. Dietary approaches assessed in this review were low-fat/high-carbohydrate diets, high-fat/low-carbohydrate diets, low-calorie (1000 kcal per day) and very-low-calorie (500 kcal per day) diets and modified fat diets. Two trials compared the American Diabetes Association exchange diet with a standard reduced fat diet and five studies assessed low-fat diets versus moderate fat or low-carbohydrate diets. Two studies assessed the effect of a very-low-calorie diet versus a low-calorie diet. Six studies compared dietary advice with dietary advice plus exercise and three other studies assessed dietary advice versus dietary advice plus behavioural approaches. The studies all measured weight and measures of glycaemic control although not all studies reported these in the articles published. Other outcomes which were measured in these studies included mortality, blood pressure, serum cholesterol (including LDL and HDL cholesterol), serum triglycerides, maximal exercise capacity and compliance. The results suggest that adoption of regular exercise is a good way to promote better glycaemic control in type 2 diabetic patients, however all of these studies were at high risk of bias. REVIEWERS' CONCLUSIONS: There are no high quality data on the efficacy of the dietary treatment of type 2 diabetes, however the data available indicate that the adoption of exercise appears to improve glycated haemoglobin at six and twelve months in people with type 2 diabetes. There is an urgent need for well-designed studies which examine a range of interventions, at various points during follow-up, although there is a promising study currently underway.

Adult↗
PubMed2004

Recovery after chronic stress fails to reverse amygdaloid neuronal hypertrophy and enhanced anxiety-like behavior.

The hippocampus and amygdala are important components of the neural circuitry mediating stress responses. While structural plasticity in the hippocampus may mediate cognitive aspects of behavioral impairments caused by severe stress, changes in the amygdala are more likely to contribute to the affective aspects of stress disorders. Recent reports have identified cellular and molecular correlates of stress-induced amygdaloid plasticity that may underlie anxiety. Hence, we examined the impact of chronic stress, in terms of its duration, at the cellular and behavioral levels in rats. We found that, even after 21 days of stress-free recovery, animals exposed to chronic immobilization stress (CIS) continue to exhibit enhanced anxiety, as manifested by a significant reduction in open-arm exploration and risk-assessment behavior in the elevated plus-maze. At the cellular level, we tested if CIS-induced dendritic remodeling in the amygdala is also as long-lasting as enhanced anxiety after 21 days of recovery. Indeed, long-lasting facilitation of CIS-induced anxiety is accompanied by a persistent increase in dendritic arborization of basolateral amygdala (BLA) spiny neurons. Moreover, CIS-induced BLA hypertrophy is distinct from hippocampal CA3 atrophy, which is reversible within the same period of stress-free recovery. These findings on persistent dendritic remodeling in the amygdala, in addition to highlighting important differences with hippocampal structural plasticity, may provide a cellular basis for examining anxiety and mood disorders triggered by chronic stress.

Amygdala↗
PubMed2004

Sodium valproate for painful diabetic neuropathy: a randomized double-blind placebo-controlled study.

BACKGROUND: Various drugs are effective in the management of painful diabetic neuropathy, but none is completely satisfactory. We previously found sodium valproate to be effective and safe in a short-term study. AIM: To test the effectiveness and safety of sodium valproate in the management of painful diabetic neuropathy over 3 months. DESIGN: Randomized double-blind placebo-controlled study. METHODS: Consecutive attending patients with type 2 diabetes mellitus with painful neuropathy were asked to participate in the trial: 48 agreed. Five were excluded: three with HbA(1c) > 11, one with too low a pain level and one who withdrew consent. The remaining 43 were given either drug (group A) or placebo (group B). Each patient was assessed clinically. Quantitative assessment of pain was done by McGill Pain Questionnaire, Visual Analogue Score and Present Pain Intensity, at the beginning of the study, after 1 month and after 3 months. Motor and sensory nerve conduction velocities were measured initially and after 3 months. Liver function tests and other adverse drug-related effects were assessed periodically. RESULTS: Of the 43 patients, four dropped out: one in group A and three in group B. There was significant improvement in pain score in group A, compared to group B, at 3 months (p < 0.001). Changes in electrophysiological data were not significant. The drug was well-tolerated by all patients, except one, who had raised serum AST and ALT levels after 1 month of treatment, and whose treatment was discontinued. DISCUSSION: Sodium valproate is well-tolerated, and provides significant subjective improvement in painful diabetic neuropathy.

Adult↗
PubMed2003

A pilot randomized trial in primary care to investigate and improve knowledge, awareness and self-management among South Asians with diabetes in Manchester.

AIMS: To investigate whether a secondary-primary care partnership education package could improve understanding of diabetes care among South Asians. METHODS: In a pilot randomized controlled trial, in the setting of eight general practices randomized to intervention or control, patients were invited to four or more rotating visits per year by one of a diabetes specialist nurse, dietician or chiropodist working with general practice staff. Participants were from lists of South Asian patients with known Type 2 diabetes in each (general) practice. RESULTS: Patients and practice scores at baseline and 1-year follow-up, from an interview using a questionnaire on knowledge, awareness and self-management of diabetes. Responses were developed into educational packages used during intervention. Of the 411 patients listed at baseline only 211 were traced for interview (refusal only 4%). Mean age was 55.4 years, age of diabetes onset 47.1 years. Fourteen percent were employed and 35% were able to communicate in English fluently. Only 118 could be traced and interviewed at 1 year, although there was no significant difference in demography between those who completed the study and those who did not. Despite a mean of four visits/patient, intervention had no impact on scores for diabetes knowledge, or awareness [score change 0.14, 95% confidence interval (CI) -0.20, 0.49] or self-management (-0.05, 95% CI -0.48, 0.39) between baseline and 1 year. CONCLUSIONS: This form of secondary/primary care support did not transfer information effectively, and we suspect similar problems would arise in other similar communities. Different methods of clinician/patient information exchange need to be developed for diabetes in this South Asian group.

Adult↗
PubMed2000

Survey of symptoms, respiratory function, and immunology and their relation to glutaraldehyde and other occupational exposures among endoscopy nursing staff.

OBJECTIVES: To find the nature and incidence of symptoms experienced by a large sample of hospital endoscopy nurses. To find whether nurses in endoscopy units develop asthma under current working conditions in endoscopy units. To obtain analytically reliable data on exposure concentrations of glutaraldehyde (GA) vapour in endoscopy units, and to relate them to individual hygiene and work practices. To characterise any exposure-response relations between airborne GA and the occurrence of work related symptoms (WRSs). Due to the growing concern about the perceived increase in WRSs among workers regularly exposed to biocides, all of whom work within a complex multiexposure environment, a cross sectional study was designed. METHODS: Current endoscopy nurses (n=348) from 59 endoscopy units within the United Kingdom and ex-employees (who had left their job for health reasons (n=18) were surveyed. Symptom questionnaires, end of session spirometry, peak flow diaries, skin prick tests (SPTs) to latex and common aeroallergens, and measurements of total immunoglobulin E (IgE) and IgE specific to GA and latex were performed. Exposure measurements included personal airborne biocide sampling for peak (during biocide changeover) and background (endoscopy room, excluding biocide changeover) concentrations. RESULTS: All 18 ex-employees and 91.4% of the current nurses were primarily exposed to GA, the rest were exposed to a succinaldehyde-formaldehyde (SF) composite. Work related contact dermatitis was reported by 44% of current workers exposed to GA, 56.7% of those exposed to SF composite, and 44.4% of ex-employees. The prevalence of WRSs of the eyes, nose, and lower respiratory tract in current workers exposed to GA was 13.5%, 19.8%, and 8.5% respectively and 50%, 61.1%, and 66.6% in the ex-employees. The mean percentage predicted forced expired volume in 1 second (ppFEV(1)) for ex-employees (93.82, 95% confidence interval (95% CI) 88.53 to 99.11) was significantly lower (p<0.01) than that of current workers exposed to GA (104.08, 95% CI 102.35 to 105.73). Occupational peak flow diaries completed by current workers with WRSs of the lower respiratory tract showed no evidence of bronchial asthma (<15% variation). Six per cent of the population had positive latex SPTs. Positive indications of one GA specific IgE and 4.1% latex specific IgE occurred. There was no conformity between the latex specific IgE and positive SPTs. Positive SPTs to latex were associated with WRSs of dermatitis and ocular WRSs, but no other WRSs. Exposures were above the current maximum exposure limit (MEL) of 0.2 mg/m(3) (0.05 ppm) in eight of the units investigated. A significant relation existed between peak GA concentrations and work related chronic bronchitis and nasal symptoms (after adjustment for types of local ventilation) but not to other WRSs. Peak GA concentrations were significantly higher in units that used both negative pressure room and decontaminating unit ventilation. CONCLUSION: This study documents a significant level of symptoms reported in the absence of objective evidence of the physiological changes associated with asthma. Ex-employees and current workers with WRSs warrant further study to elucidate the cause and mechanisms for their symptoms. Ventilation systems used for the extraction of aldehydes from the work area may be less effective than expected and due to poor design may even contribute to high peak exposures.

Air Pollutants, Occupational↗
PubMed1989

Semantic priming: subliminal perception or context?

Briefly presented, masked priming stimuli that cannot be identified by themselves can affect the processing of subsequent targets. The effect, which is sometimes viewed as a demonstration of unconscious processing, has been linked to the subliminal perception literature. Experiments 1 and 2 indicated that the identification of primes in the context of semantically related targets is superior to the identification of primes presented alone, and that the identification of primes in the context of semantically unrelated targets is inferior to the identification of primes presented alone. Experiment 3 indicated parallel findings in a recognition task. Consequently, an explanation of semantic priming in terms of the interactive nature of stimuli that are near to one another in time seems preferable to one based upon concepts of unconscious processing and subliminal perception.

Adult↗
PubMed1983

Feeding, illness and nutritional status of young children in rural Gujarat.

Eighty children, aged 0-18 months, were studied over a period of 6 months. Information was obtained from monthly interviews with mothers, when the children were also weighed. Feeding practices, incidence of illness and weight gain were described. The children who were nutritionally most at risk were identified. The average weight of the children was 1 kg less than the NCHS international reference by 3 months, 1.7 kg by 9 months. The majority of mothers did not introduce foods other than breast milk before 9 months. The children from labourers' households gained less weight between 3 and 6 months, had a higher prevalence of malnutrition and more reports of illness than children from non-labourers' households. The implications of these results for workers in child health and nutrition programmes are discussed.

Breast Feeding↗