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V Rastogi

Publications and source records attributed to V Rastogi.

At least 19 recordsLinked to original sources

Simple technique for proper approximation and closure of peritoneal and rectus sheath defects at port site after laparoscopic surgery.

Complex intra-abdominal surgical procedures can now be performed with laparoscopy, and laparoscopic cholecystectomy has become the gold standard in the care of patients with cholelithiasis. This and other surgically challenging procedures involve use of multiple large (10-mm-15-mm) ports. A standard laparoscopic cholecystectomy employs two 10-mm trocar incisions. Development of incisional hernia from these port sites is well recognized unless the rectus sheath is closed properly. This makes proper closure of the incisions for larger ports critical, especially 10-mm to 15-mm ports. However, securing abdominal wall bleeding and closing facial defects through a small incision can be a cumbersome task. We have developed a simple technique using the regular curved needle and sutures for closure of rectus sheath defects through a small port-site incision.

Adolescent↗

Mutagenesis of organophosphorus hydrolase to enhance hydrolysis of the nerve agent VX.

Organophosphorus hydrolase (OPH) is capable of hydrolyzing a wide variety of organophosphorus pesticides and chemical warfare agents. However, the hydrolytic activity of OPH against the warfare agent VX is less than 0.1% relative to its activity against parathion and paraoxon. Based on the crystal structure of OPH and the similarities it shares with acetylcholinesterase, eight OPH mutants were constructed with the goal of increasing OPH activity toward VX. The activities of crude extracts from these mutants were measured using VX, demeton-S methyl, diisopropylfluoro-phosphate, ethyl parathion, paraoxon, and EPN as substrates. One mutant (L136Y) displayed a 33% increase in the relative VX hydrolysis rate compared to wild type enzyme. The other seven mutations resulted in 55-76% decreases in the relative rates of VX hydrolysis. There was no apparent relationship between the hydrolysis rates of VX and the rates of the other organophosphorus compounds tested.

Acetylcholinesterase↗

Serum cholesterol and coronary artery disease in populations with low cholesterol levels: the Indian paradox.

OBJECTIVE: To examine the relation between serum cholesterol and coronary artery disease prevalence below the range of cholesterol values generally observed in developed countries. DESIGN AND SETTING: Cross-sectional survey of two randomly selected villages from Moradabad district and 20 randomly selected streets in the city of Moradabad. SUBJECTS AND METHODS: 3575 Indians, aged 25-64 years including 1769 rural (894 men, 875 women) and 1806 urban (904 men, 902 women) subjects. The survey methods were questionnaires, physical examination and electrocardiography. RESULTS: The overall prevalences of coronary artery disease were 9.0% in urban and 3.3% in rural subjects and the prevalences were significantly (P<0.001) higher in men compared to women in both urban (11.0 vs. 6.9%) and rural subjects (3.9 vs. 2.6%). The average serum cholesterol concentrations were 4.91 mmol/l in urban and 4.22 mmol/l in rural subjects without any sex differences. The prevalences of coronary artery disease were significantly higher among subjects with low and high serum cholesterol concentration compared to subjects with very low cholesterol and showed a positive relation with serum cholesterol within the range of serum cholesterol level studied in both rural and urban in both sexes. Among subjects with low serum cholesterol, there was a higher prevalence of coronary risk factors, hypertension, diabetes, obesity and sedentary lifestyle. Serum cholesterol level showed a significant positive relation with low density lipoprotein cholesterol and triglycerides in all the four subgroups. Logistic regression analysis after pooling of data from both rural and urban, with adjustment of age showed that low serum cholesterol level (odds ratio: men 0.96, women 0.91) had a positive strong relation with coronary artery disease and there was no evidence of any threshold. Diabetes mellitus (men 0.73, women 0.74) and sedentary lifestyle (men 0.86, women 0.74) were significant risk factors of coronary disease in both sexes. Hypertension (men 0.82, women 0.64) and smoking (men 0.81, women 0.52) were weakly associated with coronary disease in men but not in women. CONCLUSION: Serum cholesterol level was directly related to prevalence of coronary artery disease even in those with low cholesterol concentration (<5.18 mmol/l). It is possible that some Indian populations may benefit by increased physical activity and decline in serum cholesterol below the range of desired serum cholesterol in developed countries.

Adult↗

Coenzyme Q in cardiovascular disease.

Coenzyme Q10 or ubiquinone normally present in many plant and animal cells is an antioxidant. Coenzyme Q10 deficiency has been observed in patients with congestive heart failure, angina pectoris, coronary artery disease, cardiomyopathy, hypertension, mitral valve prolapse and after coronary revascularization. Coenzyme Q10 is involved in the synthesis of ATP and hence is useful in preventing cellular damage during ischaemia-reperfusion injury. The clinical benefits are mainly due to its ability to improve energy production, antioxidant activity, and membrane stabilizing properties. Several studies showed that coenzyme Q could be useful in patients with congestive heart failure, angina pectoris, cardiomyopathy, coronary artery disease and in the preservation of myocardium. Coenzyme Q10 is normally present in the low density lipoprotein cholesterol fraction and inhibits its oxidation. It can also regenerate vitamin E. Coenzyme Q10 is known for producing minor gastrointestinal discomfort and elevation in SGOT and LDH when used.

Animals↗

Randomized, double-blind, placebo-controlled trial of fish oil and mustard oil in patients with suspected acute myocardial infarction: the Indian experiment of infarct survival--4.

In a randomized, placebo-controlled trial, the effects of treatment with fish oil (eicosapentaenoic acid, 1.08 g/day) and mustard oil (alpha-linolenic acid, 2.9 g/day) were compared for 1 year in the management of 122 patients (fish oil, group A), 120 patients (mustard oil, group B), and 118 patients (placebo, group C) with suspected acute myocardial infarction (AMI). Treatments were administered about (mean) 18 hours after the symptoms of AMI in all three groups. The extent of cardiac disease, rise in cardiac enzymes, and lipid peroxides were comparable among the groups at entry into the study. After 1 year total cardiac events were significantly less in the fish oil and mustard oil groups compared with the placebo group (24.5% and 28% vs. 34.7%, p < 0.01). Nonfatal infarctions were also significantly less in the fish oil and mustard oil groups compared with the placebo group (13.0% and 15.0% vs. 25.4%, p < 0.05). Total cardiac deaths showed no significant reduction in the mustard oil group; however, the fish oil group had significantly less cardiac deaths compared with the placebo group (11.4% vs. 22.0%, p < 0.05). Apart from the decrease in the cardiac event rate, the fish oil and mustard oil groups also showed a significant reduction in total cardiac arrhythmias, left ventricular enlargement, and angina pectoris compared with the placebo group. Reductions in blood lipoproteins in the two intervention groups were modest and do not appear to be the cause of the benefit in the two groups. Diene conjugates showed a significant reduction in the fish oil and mustard oil groups, indicating that a part of the benefit may be caused by the reduction in oxidative stress. The findings of this study suggest that fish oil and mustard oil, possibly due to the presence of n-3 fatty acids, may provide rapid protective effects in patients with AMI. However, a large study is necessary to confirm this suggestion.

Adult↗

Prevalence and determinants of hypertension in the Indian social class and heart survey.

To determine the association of socio-economic status (SES) and prevalence of hypertension and its risk factors in a rural population, a cross sectional survey was conducted in two randomly selected villages in the Moradabad district in North India. There were 1935 residents aged over 25 (984 men and 951 women) who were randomly selected and categorised into social classes 1-4 depending upon SES based on occupation, housing conditions, land holding, total per capita income, ownership of consumer durables and education. The prevalence of hypertension diagnosed by JNC V criteria (>140/90 mm Hg) was significantly higher among social class 1 and 2 and showed positive relation with SES in both sexes. Among social class 1 and 2 subjects, there was a higher prevalence of overweight and obesity and sedentary lifestyle. Logistic regression analysis with adjustment of age showed that SES had a positive relation with hypertension (odds ratio: men 1.09, 95% CI 1.05-1.14; women 1.08, 95% CI 1.05-1.13), body mass index (odds ratio: men 1.12, 1.08-1.18; women 1.11, 1.06-1.16) and sedentary lifestyle (odds ratio: men 1.45, 1.32-1.58; women 1.38, 1.26-1.49). Only weak but significant associations were observed with smoking, alcohol and salt intake. The association of hypertension with social class was reduced after adjustment of body mass index, sedentary lifestyle, smoking and salt intake (odds ratio: men 0.96, 0.81-1.14; women 0.73, 0.54-1.04). There was an increase in the prevalence of hypertension and age-specific blood pressure (BP) with increasing age in both sexes. The overall prevalence of hypertension by WHO criteria (>160/95) was 4.6% and by JNC V criteria 20.8%, and the rates were comparable in both sexes. Social class 1 and 2 subjects in rural North India have a higher prevalence of hypertension and its risk factors of overweight and sedentary lifestyle.

Adult↗

Epidemiological study of hypertension and its determinants in an urban population of North India.

OBJECTIVES: To determine age-specific prevalence of hypertension and blood pressure (BP) levels in relation to diet and lifestyle factors in North Indians. DESIGN AND SETTING: Cross-sectional survey in 20 randomly selected streets in Moradabad, North India. SUBJECTS AND METHODS: A total of 1806 subjects from North India (904 males and 902 females) age range 25-64 years. The survey methods were as follows: dietary diaries for 7 days food intake record; BP measurements; physician administered questionnaire and anthropometric measurements. Diagnosis of hypertension was based on new World Health Organization/International Society of Hypertension (WHO/ISH) criteria. Risk factors were assessed based on WHO guidelines. RESULTS: The prevalence of hypertension according to WHO/ISH criteria was 23.7% and by old WHO criteria 13.3%. In the WHO/ISH hypertensive group, isolated diastolic hypertension was present in 47.3% males and 40.6% females. Males have a slightly higher prevalence than females in the young age group, however, the prevalence rates are comparable in the older age groups. In both sexes, the prevalence rates and BP level increased with older age. Multivariate analysis revealed that age, higher body mass index, central obesity and higher socioeconomic status were independently and strongly associated with hypertension in both sexes. Higher dietary fat and salt intake and lower physical activity were weakly but significantly associated with hypertension. CONCLUSION: Association of higher socioeconmic status, higher body mass index and central obesity in North Indian adults with higher fat intake, lower physical activity and higher prevalence and level of hypertension indicate that these populations may benefit by decreasing the dietary fat intake and increasing physical activity, with an aim to decrease central obesity for decreasing hypertension in North Indians.

Adult↗

Epidemiologic study of trace elements and magnesium on risk of coronary artery disease in rural and urban Indian populations.

OBJECTIVE: To determine the association of trace elements and magnesium with risk of coronary artery disease (CAD) in rural and urban populations of India. DESIGN AND SETTING: Cross-sectional surveys on the randomly selected municipal streets in Moradabad city and one village in Moradabad tahsil in North India. SUBJECTS AND METHODS: There were 162 rural (86 men and 96 women) and 152 urban (80 men and 72 women) subjects between 26 to 65 years of age. Evaluations were obtained by physician- and dietitian-administered, validated questionnaires, physical examination, electrocardiogram and blood examination. RESULTS: The prevalence of CAD and coronary risk factors was 2.5 times higher in the urban population compared to rural subjects (8.6 vs. 3.0%). In rural subjects, dietary intakes and plasma levels of vitamins and minerals were comparable with those of urban subjects except for higher dietary intake of magnesium in rural subjects and higher plasma vitamin A level in urban subjects. In both rural and urban subjects, low serum zinc (80 +/- 82 vs. 110 +/- 11.0 micrograms/dl, p < 0.05) and magnesium levels (1.60 +/- 0.36 vs. 1.71 +/- 0.41 mEQ/L, p < 0.05) and lower zinc/copper ratio (0.58 +/- 0.08 vs. 1.11 +/- 0.25 p < 0.50) were inversely associated with CAD. Serum levels of copper and iron were significantly higher and plasma levels of antioxidant vitamins A, E and C and beta-carotene were significantly lower in patients with CAD compared to the rest of the subjects. In both rural (7.1 +/- 1.2 mg/day) and urban subjects (8.6 +/- 1.6 mg/day), zinc consumption was half of the recommended dietary allowances. Higher prevalence of CAD in urban compared to rural subjects was attributed to higher dietary fat intake and higher prevalence of risk factors in urban subjects. CONCLUSIONS: The findings suggest that lower serum levels of zinc and magnesium and lower zinc copper ratio were inversely associated with CAD. It is possible that urban populations with higher risk of CAD may benefit by decreasing dietary fat intake and by increasing their intake of foods rich in zinc and magnesium.

Adult↗

Prevalence of coronary artery disease and coronary risk factors in rural and urban populations of north India.

OBJECTIVE: This study was conducted to determine and compare the prevalence of coronary artery disease and coronary risk factors in both a rural and an urban population of Moradabad in north India. DESIGN AND SETTING: A cross-sectional survey of two randomly selected villages from the Moradabad district and 20 randomly selected streets in the city of Moradabad. SUBJECTS AND METHODS: The 3575 subjects were between 25 and 64 years old; 1769 (894 men and 875 women) lived in the countryside and 1806 (904 men and 902 women) lived in the city. The survey methods were questionnaires, physical examination and electrocardiography. RESULTS: The overall prevalence of coronary artery disease, based on a clinical diagnosis and an electrocardiogram, was 9.0% in the urban and 3.3% in the rural population. The prevalences were significantly (P < 0.001) higher in the men compared with the women in both urban (11.0 vs 6.9%) and rural (3.9 vs 2.6%) populations, respectively. The prevalence of symptomatic coronary artery disease (known coronary disease and Rose questionnaire-positive angina) was 2.3% in the men (n = 19) and 1.5% in the women (n = 13) in the rural subjects, and 8.5% in the men (n = 77) and 3.4% in the women (n = 31) in the urban population. When diagnosed on the basis of electrocardiographic changes alone, the prevalences were 1.5% (n = 26) in the rural population and 3.0% (n = 55) in the urban. Coronary risk factors were two- or three-fold more common among urban subjects compared to the rural population in both sexes. Central obesity was four times more common in the urban population compared to the rural in both sexes. Sedentary lifestyle and alcohol intake were significantly (P < 0.01) higher in the urban population compared to the rural subjects. There was a significant association between coronary disease and age, hypercholesterolaemia, hypertension and central obesity in both sexes. Smoking was a significant risk factor of coronary disease in men. CONCLUSIONS: Coronary artery disease and coronary risk factors were two or three times higher among the urban compared with the rural subjects, which may be due to greater sedentary behaviour and alcohol intake among urbans. It is possible that some Indian populations can benefit by reducing serum cholesterol, blood pressure and central obesity and increasing physical activity.

Adult↗

Social class and coronary disease in rural population of north India. The Indian Social Class and Heart Survey.

OBJECTIVE: To demonstrate the association of socio-economic status with prevalence of coronary artery disease and coronary risk factors. DESIGN AND SETTING: Cross-sectional survey in two randomly selected villages in the Moradabad district in North India. SUBJECTS AND METHODS: One thousand seven hundred and sixty-seven subjects (894 males and 875 females; 25-64 years of age) were randomly selected from two villages. They were divided into social classes 1 to 4, according to education, occupation, housing conditions, ownership of land, ownership of consumer durables and per capita income. The survey was based on questionnaires administered by dietitians and physicians, physical examination and electrocardiography. RESULTS: Social classes 1 and 2 were mainly high and middle socio-economic groups and 3 and 4 low income groups. The prevalence of coronary artery disease was significantly higher among classes 1 and 2 in both sexes, and there was a higher prevalence of hypercholesterolaemia, hypertension, and sedentary lifestyle. This population also showed a significant association with higher serum cholesterol, body mass index, triglycerides and blood pressures. Logistic regression analysis with adjustment for age showed that social class positively related to coronary disease (odds ratio: men 0.83, women 0.61), hypercholesterolaemia (men 0.85, women 0.87), hypertension (men 0.89, women 0.87), body mass index (men 0.91, women 0.93) and smoking in men (0.68). Smoking and sedentary lifestyle were not associated with social class in women. The association between coronary artery disease and social class abated after adjustment for smoking, sedentary lifestyle, body mass index and blood pressure (odds ratio: men 0.96, women 0.81). CONCLUSION: Subjects in social classes 1 and 2 in rural North India have a higher prevalence of coronary artery disease and of the coronary risk factors hypercholesterolaemia, hypertension, higher body mass index and sedentary lifestyle. The overall prevalence of coronary artery disease was 3.3%.

Adult↗

Blood pressure trends, plasma insulin levels and risk factors in rural and urban elderly populations of north India.

OBJECTIVE: To compare the prevalence of hypertension and its risk factors with age-specific blood pressures in rural and urban subjects. DESIGN AND SETTING: A cross-sectional survey of two randomly selected villages and 20 randomly selected streets in Moradabad, north India. SUBJECTS AND METHODS: The subjects were 255 rural people (140 men, 115 women) and 311 urban people (172 men, 139 women) aged 60-84 years. The survey methods were questionnaires, blood pressure and anthropometric measurements and electrocardiography. RESULTS: The mean +/- SD blood pressures, both systolic (137.7 +/- 13 versus 131.2 +/- 12 mmHg) and diastolic (89.8 +/- 41 versus 85.8 +/- 9 mmHg) were significantly higher in urban men than they were in rural men. Similar differences between systolic (135.6 +/- 11 versus 129.2 +/- 10 mmHg) and diastolic (90 +/- 10 versus 87.6 +/- 9 mmHg) blood pressures were found among urban and rural women, respectively. A significant correlation between systolic blood pressures and increasing age was observed both for rural and for urban subjects of both sexes. The overall prevalences of hypertension based on World Health Organization criteria (17.6 versus 5.0%) and Joint National Committee fifth report criteria (34.0 versus 10.1%) were significantly higher among urban than they were among rural subjects. Multivariate logistic regression analysis revealed that age, body mass index, central obesity, glucose intolerance, 2 h plasma insulin and triglyceride level were associated independently with hypertension. CONCLUSIONS: The findings indicate that urban subjects had higher blood pressures than did rural subjects and that age, body mass index, central obesity and 2 h plasma insulin levels were significant risk factors for hypertension in an elderly population.

Age Factors↗

Association of trans fatty acids (vegetable ghee) and clarified butter (Indian ghee) intake with higher risk of coronary artery disease in rural and urban populations with low fat consumption.

These cross-sectional surveys included 1769 rural (894 men and 875 women) and 1806 urban (904 men and 902 women) randomly selected subjects between 25-64 years of age from Moradabad in North India. The total prevalence of coronary artery disease based on clinical history and electrocardiogram was significantly higher in urban compared to rural men (11.0 vs. 3.9%) and women (6.9 vs. 2.6%), respectively. Food consumption patterns showed that important differences in relation to coronary artery disease were higher intake of total visible fat, milk and milk products, meat, eggs, sugar and jaggery in urban compared to rural subjects. Prevalence of coronary artery disease in relation to visible fat intake showed a higher prevalence rate with higher visible fat intake in both sexes and the trend was significant for total prevalence rates both for rural and urban men and women. Subgroup analysis among urban (694 men and 694 women) and rural (442 men and 435 women) subjects consuming moderate to high fat diets showed that subjects eating trans fatty acids plus clarified butter or those consuming clarified butter as total visible fat had a significantly higher prevalence of coronary artery disease compared to those consuming clarified butter plus vegetable oils in both rural (9.8, 7.1 vs. 3.0%) and urban (16.2, 13.5 vs. 11.0%) men as well as in rural (9.2, 4.5 vs. 1.5%) and urban (10.7, 8.8 vs. 6.4%) women. Univariate and multivariate regression analysis with adjustment for age showed that sedentariness in women, body mass index in urban men and women, milk and clarified butter plus trans fatty acids in both rural and urban in both sexes were significantly associated with coronary artery disease. It is possible that lower intake of total visible fat (20 g/day), decreased intake of milk, increased physical activity and cessation of smoking may benefit some populations in the prevention of coronary artery disease.

Adult↗

Effect of diet and moderate exercise on central obesity and associated disturbances, myocardial infarction and mortality in patients with and without coronary artery disease.

OBJECTIVE: To test whether a fat modified and fruit and vegetable enriched diet in conjunction with moderate physical activity reduces the cardiac event rate in patients with coronary artery disease (CAD) and its risk factors in an urban setting in India. SUBJECTS AND METHODS: 480 patients either with CAD or with risk factors. Those with definite or possible CAD including angina pectoris (n = 210) based on World Health Organization criteria and patients with risk factors were assigned to diet A (n = 231) or diet B (n = 232) for a period of 3 years. Both groups were advised to follow a fat modified diet. Group A was also advised to consume at least 400 g/day of fruits, vegetables and legumes according to World Health Organization advice and include moderate physical activity. RESULTS: Waist-hip ratios, fasting and post-prandial blood glucose, plasma insulin levels, blood pressure and weight fell significantly in patients in group A compared with those in group B. While triglycerides in group A showed a significant decrease, high density lipoprotein cholesterol showed a significant increase. Both groups showed a significant reduction in total and low density lipoprotein cholesterol, although the decrease was greater in group A than group B. Central obesity decreased by 6.2% in group A vs. 1.2% in group B, 95% confidence interval of difference 2.3 to 7.8. The incidence of cardiac events was significantly lower in group A than group B (29 vs. 43 patients, p < 0.01). All-cause mortality also significantly declined in group A compared with group B (16 vs. 24 died, p < 0.05). The group A patients with better adherence to exercise and diet showed greater reduction in central obesity and greater decline in cardiac event rates and total mortality compared to control group B. CONCLUSIONS: It is possible that moderate physical activity in conjunction with dietary changes in patients with CAD may cause substantial reductions in central obesity and associated disturbances corresponding to a significant decrease in cardiac events and mortality during the follow-up of 3 years.

Blood Glucose↗

Epidemiological study of magnesium status and risk of coronary artery disease in elderly rural and urban populations of north India.

Cross-sectional surveys were conducted in 20 randomly selected streets in Moradabad city and two villages in Moradabad district in North India to determine the association of magnesium with risk of coronary artery disease (CAD). There were 501 rural (270 men and 231 women) and 505 urban (250 men and 255 women) subjects between 50-54 years of age inclusive. The overall prevalence of CAD was three times higher in urban than in rural subjects (11.7 vs. 3.98) and the rates were comparable in both sexes. Dietary intake of magnesium was significantly (P < 0.05) higher in rural subjects in both men (520 +/- 58 vs. 415 +/- 47 mg/d) and women (432 +/- 40 vs. 316 +/- 38 mg/d). Dietary magnesium intake and serum magnesium were inversely correlated with CAD. The odds ratio for dietary magnesium intake indicates a higher prevalence of CAD at lower intakes of magnesium in both rural (0.67, 95 per cent confidence interval 0.51 to 0.86) and urban (0.72, 95 per cent CI 0.54 to 0.90) subjects. Multivariate regression analysis showed that serum and dietary magnesium were significantly associated with CAD. Hypertension was not associated with CAD, and serum cholesterol showed only weak association in both rural and urban subjects. The inverse association of dietary and serum magnesium with CAD shows that some urban populations of India may benefit from increased consumption of dietary magnesium and higher serum magnesium levels.

Aged↗

Epidemiological study of magnesium status and risk of hypertension in a rural population of north India.

This cross-sectional survey was conducted in two randomly selected villages in Moradabad in North India to demonstrate the association of magnesium status with hypertension in relation to socioeconomic status (SES) in a rural population. There were 1769 subjects (894 males, 875 females) between 25 and 64 years of age, randomly selected and divided into social classes 1-4 depending upon various sociological attributes. The survey methods were a validated questionnaire, blood pressure measurements by mercury manometer, and blood analysis for serum magnesium. Social class 1 and 2 were associated with a greater prevalence of hypertension. The overall prevalence of hypertension diagnosed by JNC-V criteria (> 140/90 mm Hg) was 17.7 per cent (n = 313) and the prevalence was comparable in both sexes and increased with age. Among social class 1 and 2 subjects, there was a higher prevalence of obesity and sedentary lifestyle, a lower intake of dietary magnesium, and a lower serum magnesium compared to social class 3. Logistic regression analysis with adjustment for age showed that SES has a positive relation with hypertension (odds ratio 1.08 men, 1.07 women, P < 0.05), body mass index (odds ratio 1.14 men, 1.13 women, P < 0.01), and sedentary lifestyle (odds ratio 1.38 men, 1.32 women, P < 0.05) in both sexes, and with salt intake in women (odds ratio 1.28, P < 0.05). The odds ratio indicated that a higher intake of magnesium (odds ratio 1.14 men, 1.17 women, P < 0.05) and a higher serum magnesium (odds ratio 1.12 men, 1.15 women, P < 0.05) were associated with a lower risk of hypertension. The findings suggest that social class 1 and 2 subjects in some rural populations of India have a higher prevalence of hypertension and dietary intake of magnesium, and serum magnesium levels were inversely associated with the risk of hypertension.

Adult↗

Magnesium and antioxidant vitamin status and risk of complications of ageing in an elderly urban population.

This cross-sectional survey was conducted in 20 randomly selected streets in Moradbad city in North India to determine the association of magnesium and antioxidant vitamins with risk of ageing. There were 595 subjects (314 males, 281 females) between 50-84 years of age inclusive. The overall prevalence of hypo-magnesemia was 11.8 per cent (n = 60) with a prevalence of 13.2 per cent (n = 33) in males and 10.6 per cent (n = 27) in females. The prevalence of hypomagnesemia showed significant declining trend in the concentration of serum magnesium, vitamin C, vitamin E and beta-carotene and a rising trend in lipid peroxides and diene conjugates with increase in age from 50-59 years to 70-84 years in both men and women. Multivariate logistic regression analysis showed that serum magnesium, vitamin C, vitamin E and beta-carotene were significant risk factors of ageing in both men and women. The findings suggest that some urban populations of India can benefit by consuming higher dietary magnesium, potassium and antioxidant vitamins for prevention of ageing.

Aged↗

Symbiotic nitrogen fixation by a nifA deletion mutant of Rhizobium meliloti: the role of an unusual ntrC allele.

In the N2-fixing alfalfa symbiont Rhizobium meliloti, the three sigma 54 (NTRA)-dependent positively acting regulatory proteins NIFA, NTRC, and DCTD are required for activation of promoters involved in N2 fixation (pnifHDKE and pfixABCX), nitrogen assimilation (pglnII), and C4-dicarboxylate transport (pdctA), respectively. Here, we describe an allele of ntrC which results in the constitutive activation of the above NTRC-, NIFA-, and DCTD-regulated promoters. The expression and activation of wild-type NTRC occur in response to nitrogen availability, whereas in cells carrying the ntrC283 allele, the NTRC283 protein appears constitutively active and is constitutively expressed. The ntrC283 allele was shown to carry a single mutation resulting in the replacement of an Asp by a Tyr residue in the helix-turn-helix motif of ntrC283. Introduction of the ntrC283 allele into a nifA deletion mutant restores the N2-fixation ability to 70 to 80% of the wild-type level. Thus, the nifA gene is dispensable for symbiotic N2 fixation.

Alleles↗

Overexpression of the dctA gene in Rhizobium meliloti: effect on transport of C4 dicarboxylates and symbiotic nitrogen fixation.

Symbiotic nitrogen fixation may be limited by the transport of C4 dicarboxylates into bacteroids in the nodule for use as a carbon and energy source. In an attempt to increase dicarboxylate transport, a plasmid was constructed in which the Rhizobium meliloti structural transport gene dctA was fused to a tryptophan operon promoter from Salmonella typhimurium, trpPO. This resulted in a functional dctA gene that was no longer under the control of the dctBD regulatory genes, but the recombinant plasmid was found to be unstable in R. meliloti. To stably integrate the trpPO-dctA fusion, it was recloned into pBR325 and recombined into the R. meliloti exo megaplasmid in the dctABD region. The resultant strain showed constitutive dctA-specific mRNA synthesis which was about 5-fold higher than that found in fully induced wild-type cells. Uptake assays showed that [14C]succinate transport by the trpPO-dctA fusion strain was constitutive, and the transport rate was the same as that of induced control cells. Acetylene reduction assays indicated a significantly higher rate of nitrogen fixation in plants inoculated with the trpPO-dctA fusion strain compared with the control. Despite this apparent increase, the plants had the same top dry weights as those inoculated with control cells.

Bacterial Proteins↗