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Biomedical subjects

S K Dwivedi

Publications and source records attributed to S K Dwivedi.

At least 19 recordsLinked to original sources
PubMed2006

Nucleotide polymorphism associated with ethambutol resistance in clinical isolates of Mycobacterium tuberculosis.

Ethambutol (EMB) is a first-line drug used for antitubercular therapy in combination with other drugs as recommended by World Health Organization DOTS/DOTS-Plus regimens. EMB is also effective in the treatment of opportunistic mycobacterial infections in patients with human immunodeficiency virus. The emb locus has been considered as a drug target for EMB, and substitutions of codon 306 in Mycobacterium tuberculosis gene embB have been shown to be the most frequent and predictive mutations for EMB resistance. The aim of the present study was to detect embB and embC gene mutations in EMB-resistant clinical isolates. A total of 23 isolates of M. tuberculosis from patients with pulmonary tuberculosis were included in the study. Drug sensitivity was tested by proportion method and E-test. All 23 isolates were EMB resistant. Primers to amplify the embB and embC gene were designed, and polymerase chain reaction products were subjected for sequence analysis. H37Rv standard laboratory strain was used as control. Nucleotide sequencing showed that 16 strains had a mutation in the embB gene. The most common mutation observed in the embB gene was at codon 306, followed by mutations at codons 299 and 378 in 4 and 2 isolates, respectively. Novel mutations have been reported at codons 239, 240, 247, 282, 311, 368, 397, 446, 469, and 471. Sequence analysis of the embC gene showed mutation in 8 isolates at codon 270. Novel mutations in embC have been reported at codons 251 and 254. The most common nucleotide polymorphism in our isolates was at codons 306 and 299 in the embB gene and at codon 270 in the embC gene. A mutation at codon 306 was usually associated with high-level ethambutol resistance.

Antitubercular Agents↗
PubMed2006

Diastolic and systolic right ventricular dysfunction precedes left ventricular dysfunction in patients paced from right ventricular apex.

BACKGROUND: Cardiac dysfunction after right ventricular (RV) apical pacing is well known but its extent, time frame of appearance and individual effect on left ventricular (LV), RV systolic and diastolic parameters has not evaluated in a systematic fashion. METHODS: Patients with symptomatic bradycardia and ACC-AHA Class I indication for permanent pacemaker implantation (PPI) were implanted a single chamber (VVI) pacemaker. They were followed prospectively by echocardiographic examination which was done at baseline, 1 week, 1 month and 6 months after implantation. Parameters observed were chamber dimensions (M-line), chamber volumes, cardiac output (modified Simpson's method), systolic functions (ejection fraction, pre-ejection period, ejection time and ratio) and diastolic functions( isovolumic relaxation time & deceleration time) of left and right heart. RESULTS: Forty eight consecutive patients (mean age 65.6+/-11.8 yrs, 66.7% males, mean EF 61.82+/-10.36%) implanted a VVI pacemaker were enrolled in this study. The first significant change to appear in cardiac function after VVI pacing was in diastolic properties of RV as shown by increase in RV isovolumic relaxation time (IVRT) from 65.89+/-15.93 to 76.58+/-17.00 ms,(p<0.001) at 1week and RV deceleration time (DT) from 133.84+/-38.13 to 153.09+/-31.41 ms, (p=0.02) at 1 month. Increase in RV internal dimension (RVID) from 1.26+/-0.41 to 1.44+/-0.44, (p<0.05) was also noticed at 1 week. The LV diastolic parameters were significantly altered after 1 month with increase in LV-IVRT from 92.36+/-21.47 to 117.24+/-27.21ms, (p<0.001) and increase in LV DT from 147.56+/-31.84 to 189.27+/-28.49ms,(p<0.01). This was followed by LV systolic abnormality which appeared at 6 months with an increase in LVPEP from 100.33+/-14.43 to 118.41+/-21.34ms, (p<0.001) and increase in LVPEP/LVET ratio from 0.34+/-0.46 to 0.44+/-0.10, (p<0.001)]. The reduction in LV EF was manifested at 6 months falling from 61.82+/-10.36% to52.52+/-12.11%, (p<0.05) without any significant change in the resting cardiac output. CONCLUSION: The present study shows that dysfunction of right ventricle is the first abnormality that occurs in VVI paced patients, which manifests by 1 week followed by LV dysfunction which starts appearing by 1 month and the diastolic dysfunctions precede the systolic dysfunction in both ventricles.

Journal Article↗
PubMed2005

Blood lead level in dogs from urban and rural areas of India and its relation to animal and environmental variables.

Lead is a common environmental pollutant with deleterious health effects on human and animal. Industrial and other human activities enhance the lead level in the environment leading to its higher residues in exposed population. The present study was aimed at determining blood lead concentration in dogs from two urban areas and in surrounding rural areas of India and analyzing lead level in dogs in relation to environmental (urban/rural) and animal (age, sex, breed and housing) variables. Blood samples were collected from 305 dogs of either sex from urban (n=277) and unpolluted rural localities (n=28). Irrespective of breed, age and sex, the urban dogs had significantly (P<0.01) higher mean blood lead concentration (0.25+/-0.01 microg/ml) than rural dogs (0.10+/-0.01 microg/ml). The mean blood lead level in stray dogs either from urban or rural locality (0.27+/-0.01 microg/ml) was significantly (P<0.01) higher than that of pets (0.20+/-0.01 microg/ml), and the blood lead concentration was significantly higher in nondescript dogs (0.25+/-0.01 microg/ml) than pedigreed dogs (0.20+/-0.01 microg/ml). The locality (urban/rural) was the major variable affecting blood lead concentration in dogs. Breed and housing of the dogs of urban areas and only housing (pet/stray) in rural areas significantly (P<0.01) influenced the blood lead concentration in dogs.

Animals↗
PubMed2004

Lead in blood of urban Indian horses.

A cross sectional study recorded the Lead (Pb) concentrations in blood from 288 horses in urban areas. Mean blood Pb concentration was estimated as 0.47 +/- 0.02 and 0.55 +/- 0.02 ppm in horses for industrial and highway-adjacent localities respectively. Mean blood Pb in horses from rural areas was 0.38 +/- 0.03 ppm. The mean Pb in forage samples from these horses was 36.96 +/- 6.23, 52.08 +/- 9.86 and 11.72 +/- 1.34 ppm in industrial, highway-adjacent and rural localities respectively. No overt signs of Pb toxicosis were seen in these animals

Animals↗
PubMed2002

Fluoride concentrations in thoroughbred horses in India.

Fluoride possesses both essential and toxic potentials. A cross-sectional study recorded the fluoride concentrations in sera of thoroughbred horses 5y of age from 4 localities in India. A total of 628 serum samples of were analyzed for fluoride content using ion selective potentiometry. The mean serum fluoride was estimated as 0.018 +/- 0.002, 0.096 +/- 0.004, 0.16 +/- 0.008 and 0.32 +/- 0.02 ppm in horses from the eastern, central. western and southern parts of the country respectively. Although there were significant difference in fluoride concentration among horses from different zones, all werewithin the normal range for this species.

Animals↗
PubMed2001

Antioxidant effects of alpha tocopherol, ascorbic acid and L-methionine on lead induced oxidative stress to the liver, kidney and brain in rats.

Lead exposure related oxidative stress has been incriminated, at least in part, to its toxic effects in different organs. The present investigation was carried out to study the ameliorative effects of antioxidant (ascorbic acid, alpha tocopherol or L-methionine) alone and antioxidant (alpha tocopherol) plus a conventional chelator (CaNa2 EDTA) on some of the parameters indicative of oxidative stress in the liver, kidney and brain in lead-exposed rats. Rats were given 0 (n=6, healthy controls) or 1 mg of Pb(2+)/kg b.w (n=30) as lead acetate solution in sterile normal saline ip for a period of 4 weeks. The ip injections were then withdrawn and lead exposed rats were randomly divided into five equal groups. Six lead-exposed rats were given no treatment during the 5th week (Pb group) to serve as positive controls. The rest four groups received either ascorbic acid, alpha tocopherol or L-methionine in the 5th week at the daily dose of 100 mg/kg b.w orally or alpha tocopherol as above plus CaNa2 EDTA at the rate of 110 mg/kg b.w twice a day ip for a period of 4 days. All the animals were sacrificed 1 day after the end of the experiment, and the liver, kidney and brain were quickly excised for the estimation of lead burden and alteration in the oxidative indices. Lead exposure for a period of 4 weeks followed by a period of 1 week to recover, resulted in significantly (P<0.05) higher accumulation of lead, associated with significant (P<0.05) increases in lipid peroxide level in the liver and brain, and non-protein bound thiol contents in the brain. Changes in the superoxide dismutase and catalase activities in lead-exposed rats did not reach statistical (P<0.05) significance. Treatment with antioxidants alone resulted in reversal of oxidative stress without significant decline in tissue lead burden. Tissue specific changes, following lead exposure and responses to the treatment with different antioxidants were recorded in the parameters of oxidative damage viz. lipid peroxide level, antioxidant enzymes and thiol contents.

Animals↗
PubMed2001

Silent ischemic interval on exercise test is a predictor of response to drug therapy: a randomized crossover trial of metoprolol versus diltiazem in stable angina.

BACKGROUND AND HYPOTHESIS: There is no method available to predict the relative antianginal efficacy of beta blockers and calcium-channel antagonists. The present study was undertaken to assess the role of silent ischemic interval (SII) on exercise treadmill test (ETT) as a predictor of response to therapy with metoprolol and diltiazem in patients with stable angina. METHODS: Thirty-four patients with stable angina were divided into two groups depending upon the presence or absence of an SII gap of at least 1 min between onset of ST depression and appearance of angina on ETT. Metoprolol (50-100 mg twice daily) and diltiazem (60-120 mg three times daily) were randomly assigned for 6 weeks to patients in each group, and then patients were crossed over for further 6 weeks after a washout period of 2 weeks. Antianginal efficacy was assessed by clinical and exercise parameters. RESULTS: In patients with SII, the clinical responder rate was better with metoprolol than with diltiazem (90 vs. 60%, respectively), and on ETT, metoprolol produced significant improvement in the total exercise time (p< 0.01), time to 1 mm ST depression (p <0.01), time to angina (p <0.01), and a significant decrease in peak rate-pressure product (p<0.001), whereas diltiazem had no significant effect on exercise parameters. However, in patients without SII, metoprolol and diltiazem had a similar clinical responder rate (57%), and both produced a significant increase in total exercise time (p < 0.01), time to 1 mm ST depression (p < 0.01), and time to angina (p < 0.01). In addition, metoprolol had a significant effect on peak rate-pressure product (p < 0.001). CONCLUSION: Silent ischemic interval on ETT can be a predictor of response to antianginal therapy in stable angina, as patients with SII respond better to metoprolol and those without SII respond equally to both metoprolol and diltiazem.

Adrenergic beta-Antagonists↗
PubMed2001

Effect of garlic (Allium sativum L.) extract on tissue lead level in rats.

The prophylactic efficacy of garlic (Allium sativum L.) extract to reduce tissue lead (Pb) concentration was evaluated experimentally in rats. Thirty female rats were divided into five groups, keeping group A as a healthy control. Rats of groups B, C, D and E received lead acetate orally at the rate of 5 mg per kg body weight daily for 6 weeks. The garlic extract was tried in three doses, viz. 100 (low), 200 (medium) and 400 mg (high) per kg body weight orally and given simultaneously with lead salt to the rats of group C, D and E, respectively. Mean blood lead concentrations in lead-exposed rats ranged between 0.13+/-0.02 and 0.96+/-0.06 microg/ml, whereas in garlic-treated rats, the range was between 0.16+/-0.01 and 0.80+/-0.05; 0.13+/-0.01 and 0.71+/-0.06 and 0.14+/-0.01 and 0.60+/-0.05 microg per ml in low, medium and high dose groups, respectively. The mean lead concentration in liver, kidneys, brain and bone of lead exposed rats was 2.943+/-0.206, 4.780+/-0.609, 1.019+/-0.100 and 44.075+/-2.60 microg per ml, respectively. Concomitant use of garlic extract at the three different doses was found to reduce lead concentration considerably indicating the potential therapeutic activity of garlic against lead.

Animals↗
PubMed2001

Enhanced lipid peroxide levels in the erythrocytes of calves with haemoglobinuria.

Eight 6-9 month old calves, showing clinical signs of intermittent haemoglobinuria, even after treatment with an antipiroplasmal drug (4,4-diamidinodiazaminobenzene diaceturate), were examined for oxidative damage to their erythrocytes and the presence of hemoprotozoa in blood smears. Four calves without signs of haemoglobinuria served as controls. The blood smears from three of the eight calves contained piroplasms for Theileria annulata. Irrespective of the presence of piroplasms in their blood smears, the calves with haemoglobinuria had significantly (p < 0.01) lower haemoglobin concentrations (Hb) and packed cell volumes (PCV). The lipid peroxide level in the erythrocytes, but not in the plasma, of calves with red urine was significantly (p <0.05) higher than that for the controls. It is concluded that haemoglobinuria, irrespective of the presence of piroplasms in blood smears, is associated with oxidative stress to erythrocytes and peroxidation of polyunsaturated fatty acids of cell membrane.

Animals↗
PubMed2001

Lead poisoning in cattle and buffalo near primary lead-zinc smelter in India.

Varying degrees of lead (Pb) poisoning was recorded in cows and buffaloes near a primary lead-zinc smelter in India. Affected animals had history of clinical signs characterized by head pressing, violent movement, blindness and salivation. These animals revealed considerably high lead levels in blood (1.43 +/- 0.07 ppm) and milk (0.75 +/- 0.19 ppm). Animals from the same place without the history of clinical signs suggestive of Pb poisoning recorded lower blood Pb levels than the affected animals; however, their blood Pb was higher than that reported for cattle in rural and urban areas of India. Affected animals also carried high levels of cadmium (Cd) in blood (0.11 +/- 0.01 ppm) and milk (0.05 +/- 0.01 ppm). These values were considerably higher than those for rural cattle in India. The findings indicated varying degrees of exposure of animals to Pb and Cd in the vicinity of the smelter.

Animal Feed↗
PubMed2000

Industrial fluorosis in cattle and buffalo around Udaipur, India.

Signs of dental discolouration, difficulty in mastication, bony lesions, lameness, debility and mortality in domesticated animals, reared around superphosphate fertiliser plants located approximately 15 km north of Udaipur, Rajasthan prompted us to investigate for the occurrence of fluorosis. Out of 166 animals clinically examined, the prevalence rate was 17.4% (4/23) in calves below 1 year of age, 37.2% (16/43) in cattle between 1 and 3 years, 61.3% (46/75) in cattle above 3 years and 72% (18/25) in buffalo above 1 year. Dental fluorosis was common in buffalo compared to cattle of all the age groups. Fluoride levels in fodder and water, consumed by the animals were much higher than the recommended permissible limit. Mean fluoride concentrations in serum and urine were 1.53 +/- 1.27 and 26.4 +/- 6.17 mg l(-1) in calves below 1 year of age, 0.56 +/- 0.17 and 26.2 +/- 3.86 mg l(-1) in cattle of 1-3 years, 0.49 +/- 1.13 and 27.5 +/- 4.63 mg l(-1) in cattle above 3 years and 0.60 +/- 0.07 and 28.6 +/- 4.73 mg l(-1) in buffalo over 1 year, respectively. The values were significantly (P < 0.01) higher than those of control animals kept over a 15-km distance from the factories. Fluoride concentrations in the environmental sample collected from the affected locality were 534.4 +/- 74.9 mg kg(-1) in fodder, 1.19 +/- 0.29 mg l(-1) in pond water and 0.479 +/- 0.351 mg l(-1) in tube well water. It was concluded that the consumption of fodder and water contaminated by the fumes and dusts emitting from superphosphate fertiliser plants resulted in the development of chronic fluorotic lesions in cattle and buffalo.

Air Pollutants↗
PubMed2000

Blood lead and cadmium in dogs from urban India.

Concentrations of lead and cadmium were estimated in blood samples of 43 healthy dogs from urban India. Concentrations were 19.5+/-2.1 microg lead/dL and 0.74+/-0.13 microg cadmium/dL, which were considerably higher for rural dogs. Sex, age, and diet had no significant effect on lead and cadmium blood concentrations, yet male and adult dogs had higher levels than females and young dogs. The use of dogs as sentinels for environment quality in India was indicated by this study.

Animals↗
PubMed2000

Effect of thiamine hydrochloride on lead induced lipid peroxidation in rat liver and kidney.

Thiamine hydrochloride was studied on lead-induced endogenous lipid peroxidation in rat hepatic and renal tissues following po doses of 2.73 mg lead/kg bw for 6 w. Simultaneous use of 25 mg thiamine hydrochloride/kg bw po reduced lead accumulation in liver and kidneys. There were significant decreases in endogenous lipid peroxide in liver and kidney from thiamine hydrochloride-treated rats. Histopathological lesions in thiamine-treated livers and kidneys were milder in comparison to lesions in untreated Pb-exposed animals. This indicates the prophylactic potential of thiamine for lead-induced lipid peroxidation.

Animals↗
PubMed1999

Lead and cadmium concentrations in milk and blood of Indian cows with mastitis.

Mean milk lead in cows with clinical or subclinical mastitis was 0.35 +/- 0.03 or 0.42 +/- 0.04 ppm whereas cadmium was 0.16 +/- 0.01 or 0.15 +/- 0.01 ppm. Concentrations in blood were 0.45 +/- 0.05 lead or 0.08 +/- 0.05 ppm cadmium in clinical and 0.47 +/- 0.06 lead or 0.088 +/- 0.001 ppm cadmium in subclinical mastitic cows.

Animals↗
PubMed1998

Left ventricular diastolic collapse in low-pressure cardiac tamponade.

A case of systemic hypotension with volume depletion not responding to intravenous fluids was found to have features of cardiac tamponade on two-dimensional (2-D) echocardiography. Intracardiac pressures were normal on cardiac catheterization. An interesting observation was the presence of left ventricular (LV) collapse on 2-D echocardiography. To the authors' best knowledge, such a case of low pressure cardiac tamponade with LV collapse has not been reported earlier.

Adolescent↗
PubMed1997

Hydrofluorosis in water buffalo (Bubalus bubalis) in India.

The concentration of fluoride was determined in water, forage and urine and serum samples of buffaloes from the Unnao district of India. The water and forage samples contained 2.01 +/- 0.51 and 22.50 +/- 0.82 ppm of fluoride, respectively. The analysis of biosamples collected from the affected animals revealed higher levels of fluoride in serum (0.58 +/- 0.05 ppm) and urine (10.64 +/- 1.23 ppm). Clinical examination identified a 40.34% prevalence rate of clinical lesions suggestive of fluorosis in buffalo of this locality. Dental lesions were present invariably in all affected animals whereas lameness, painful bony exostosis and emaciation were recorded in 28.17%, 8.45% and 76.00% of the animals. Based on the clinical lesions and fluoride content in water, serum and urine, it was concluded that the problem of fluorosis in buffalo is attributable to drinking water containing toxic levels of fluoride.

Animal Feed↗
PubMed1997

Hypoglycaemic, antihyperglycaemic and hypolipidemic activities of Caesalpinia bonducella seeds in rats.

Hypoglycaemic, antihyperglycaemic and hypolipidemic activities of the aqueous and 50% ethanolic extracts of Caesalpinia bonducella Fleming (Leguminosae) seeds were studied in normal and streptozotocin (SZ)-diabetic rats. In normal rats, both the extracts exhibited hypoglycaemic activity as early as 4 h after administration at a lower dose of 100 mg/kg. The hypoglycaemia produced by the aqueous extract was of prolonged duration as compared to ethanolic extract. In diabetic rats, both the extracts produced significant (P < 0.01) antihyperglycaemic effect from day 5 onwards. Aqueous extract also exhibited antihypercholesterolemic and antihypertriglyceridemic effects in SZ-diabetic rats. These results suggest that C. bonducella seeds possess an antidiabetic principle and can be useful for treatment of diabetes. Further studies are warranted to fractionate the active principle and to find out its exact mechanism of action.

Administration, Oral↗