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Biomedical subjects

N Tripathi

Publications and source records attributed to N Tripathi.

10 recordsLinked to original sources
PubMed2001

Toxic effects of arsenic (III) on some hematopoietic and central nervous system variables in rats and guinea pigs.

OBJECTIVE: To evaluate the effects of arsenic (III) exposure on porphyrin metabolism and the central nervous system supplemented with data on the effect of hepatic and renal tissues of rats and guinea pigs. METHODS: Rats and guinea pigs were exposed to 10 or 25 ppm arsenic in drinking water for 16 weeks. RESULTS: Following chronic arsenic (III) exposure, delta-aminolevulinic acid dehydratase activity in blood showed a significant reduction as did the total cell counts (RBC and WBC) and reduced glutathione with increased urinary delta-aminolevulinic acid. Zinc protoporphyrin, a sensitive indicator of iron deficiency and impairment of heme biosynthesis, showed a significant increase in arsenic exposure. The hepatic delta-aminolevulinic acid dehydratase and delta-aminolevulinic acid synthetase activity increased in chronic arsenic (III) exposure in rats and guinea pigs. Significant changes in the steady-state level of three major neurotransmitters, dopamine, norepinephrine, and 5-hydroxytryptamine, and monoamine oxidase were observed following chronic arsenic (III) exposure. CONCLUSION: At low doses (10 and 25 ppm in drinking water), the effects of arsenic on hematopoietic indices and whole-brain neurotransmitter concentrations were more prominent in guinea pigs than in rats with some variability in the dose response.

5-Aminolevulinate Synthetase↗
PubMed1998

Effects of thiamin and methionine administration in preventing cadmium-induced biochemical alterations and metal concentration in male rats.

Thiamin or methionine supplementation was equally and moderately effective in preventing the accumulation of cadmium in soft organs and alterations in a few selected biochemical indices during concomitant administration. Adequate intake of sulfur amino acid following methionine supplementation might increase the bioavailability of glutathione, facilitating the prevention of the binding of cadmium to different compartments and consequently reversing cadmium-induced biochemical disorders. In the case of thiamine the possibility of formation of a readily excretable complex between cadmium and thiamine or an increase in the body's resistance to cadmium might be the beneficial factor.

Absorption↗
PubMed1998

Hepatic and renal metallothionein induction following single oral administration of gallium arsenide in rats.

Metallothionein genes (MT) are inducible by a variety of agents, including heavy metals. We report the induction of MT expression by gallium arsenide (GaAs), a superior intermetallic semiconductor material at two time intervals following single oral exposure in rats. The data is also supplemented with two additional groups exposed to gallium (III) as gallium oxide and arsenic (III) as sodium arsenite to determine which of the two moieties in GaAs is responsible for any such possible effects. The results indicate that GaAs administration does significantly induces MT in hepatic tissues accompanied by an increase in cytosolic glutathione, arsenic, zinc and copper concentration. It thus proves that arsenic moiety is chiefly responsible for such an effect.

Administration, Oral↗
PubMed1998

Effects of some thiol chelators on enzymatic activities in blood, liver and kidneys of acute arsenic (III) exposed mice.

The effects of meso 2, 3-dimercaptosuccinic acid (DMSA), sodium 2, 3-dimercaptopropane 1-sulfonate (DMPS) and S-adenosyl L-methionine (SAM) on the enzymatic activities of mice were studied. The mice were given intraperitoneal (i.p.) injections of these chelating agents (1 mmol/kg) and 3 h later the activity of delta-aminolevulinic acid dehydratase (ALAD) in the blood, and aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma-glutamyltranspeptidase (gamma-GT), alkaline phosphatase (ALP) in the liver and kidney were determined. The activity of blood ALAD was significantly increased by the administration of DMSA and SAM while DMPS had only a moderate effect. The activities of other hepatic enzymes changed little when the mice were treated with these chelating agents, except for a significant reduction in hepatic ALP activity following DMPS administration. Arsenic (III) administration markedly increased the activities of ALT and ALP in the liver and kidneys. The changes in the enzymatic activities by treatment with arsenic were prevented by injection of DMSA, DMPS and SAM, DMSA being the most effective. These results indicate that DMSA, DMPS and SAM were not toxic to the liver or kidneys of mice and that treatment with DMSA is more effective than DMPS or SAM in protecting mice from acute hepatic or renal toxicity caused by arsenic.

Alanine Transaminase↗
PubMed1997

Arsenic-induced changes in certain neurotransmitter levels and their recoveries following chelation in rat whole brain.

Arsenic as sodium arsenite (100 ppm in drinking water) was administered to male rats for 16 weeks. Animals were then treated either with meso-2,3-dimercaptosuccinic acid (DMSA), sodium 2,3-dimercaptopropane 1-sulfonate (DMPS), dimethyl DMSA (DmDMSA), or diisopropyl DMSA (DiPDMSA) twice daily (50 mg/kg) intraperitoneally for 5 days. After 5 days of rest period, the animals were again given a second course of chelation therapy. The animals were sacrificed subsequently for the determination of whole brain biogenic amines levels, acetylcholinesterase (AChE), monoamine oxidase (MAO) and delta-aminolevulinic acid dehydratase (ALAD) activities. A number of biochemical parameters and arsenic concentrations in some tissues were also determined. The results suggest a significant increase in brain arsenic concentration accompanied by alterations in neurotransmitters levels following As(III) exposure. Although chelation treatment was effective in reducing As burden, the altered biochemical variables responded less favorably to chelation therapy. The DMSA-diesters, particularly DiPDMSA, produced a more pronounced increase in brain arsenic burden, as well as alterations in a few neurotransmitters. It can be concluded that the lipophilic character of As antidotes may lead to unfavorable results following intraperitoneal administration.

Alanine Transaminase↗
PubMed1992

Sequential MTX-5 FU chemotherapy in pallination of advanced cancer cervix.

Twenty four patients with advanced cancer of cervix were submitted to sequential chemotherapy 5FU and MTX. The response rate was 85% in stage III and 50% in stage IV. Overall response rate was 75%. Patients who had not received radiotherapy earlier responded better than those who had received it earlier. This easy and economical modality has importance in view of late reporting and advanced stage of disease encountered in our set up.

Aged↗
PubMed1990

Peri-operative oxytetracycline in prophylaxis of surgical wound infections.

Experience with peri-operative oxytetracycline coverage in prevention of wound infection following elective surgery is presented; of 150 cases included in control group 21 developed infection (14%), whereas only 4 of the study group (170 cases) had infection (2.5%). The importance of peri-operative antibiotic umbrella is emphasised and some of the shortcomings of recommended schedule is highlighted.

Adolescent↗
PubMedDate not supplied

Left ventricular pacing through coronary sinus tributaries: initial experience.

BACKGROUND: Left ventricular pacing is increasingly being used as a part of biventricular pacing in congestive heart failure but data on safety, feasibility, reliability and lead maturation are sparse. METHODS AND RESULTS: Seventeen patients (13 males and 4 females) with persistent symptomatic degenerative complete heart block underwent temporary left ventricular pacing by a left subclavian puncture through the coronary sinus to its tributaries using a unipolar permanent pacing lead connected to an external pulse generator. The left ventricular pacing was done for two weeks. Permanent right ventricular apical pacing was also done at the same time through a right cephalic vein cut-down or subclavian puncture and the pacing rate was kept below that of the initial left ventricular pacing rate. Pacing parameters of the left and right ventricles were assessed at the time of implantation and at two weeks. Out of 17 patients, left ventricular pacing was successful in 11 (67.7%) patients. The time taken for the total procedure was 56+/-18.1 min. Lead displacement was noted in one patient without loss of pacing. At the time of implant and after two weeks, left ventricular pacing threshold, impedance, R wave height and slew rate were not different as compared to right ventricular pacing. Holter recording for 24 hours revealed regular left ventricular pacing at the end of two weeks in all patients. CONCLUSIONS: The present study shows that left ventricular pacing through coronary sinus tributaries is feasible and reliable. Acute and subacute maturation of left ventricular pacing are similar to right ventricular apical pacing.

Aged↗
PubMedDate not supplied

Short-term (48 hours) versus long-term (7 days) antibiotic prophylaxis for permanent pacemaker implantation.

BACKGROUND: Infection following permanent pacemaker implantation is a dreaded complication. Antibiotic prophylaxis for 1-10 days at the time of implant has been used in the past but there is no consensus regarding its duration. We carried out a prospective, randomized study of two durations of antibiotic prophylaxis to determine which one was more effective. METHODS AND RESULTS: One hundred and seventy-eight patients undergoing permanent pacemaker implantation for the first time were randomized to receive short duration (group A, n = 8 8) or longer duration (group B, n = 90) antibiotic prophylaxis for 2 days and 7 days, respectively. Patients in both groups received cloxacillin 2 g 2 hours prior to the procedure followed by ampicillin and cloxacillin (50 mg/kg/day in 4 divided doses) and gentamicin (3 mg/kg/day in 2 divided doses) for the respective duration. Patients were followed up for 1-17.3 months (9.3 +/- 1.8 months) in group A and 1-16.5 months (8.9 +/- 2 months) in group B. One patient in group B had an infection at the pacemaker site and two patients in each group had to undergo reimplantation due to pus in the pocket. There was no significant difference in the primary end-point in both groups. CONCLUSIONS: A short course (48 hours) of antibiotic prophylaxis following permanent pacemaker implantation is as effective as a longer course (7 days).

Anti-Bacterial Agents↗