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Biomedical subjects

R Kumari

Publications and source records attributed to R Kumari.

At least 37 records · Page 2Linked to original sources
PubMed1998

Alterations in the vasoreactivity of hypertensive rat aortic rings: role of nitric oxide and superoxide radicals.

OBJECTIVES: Present study was undertaken to investigate involvement of nitric oxide (NO) and superoxide radicals in the modulation of vasoreactivity in a model of renal hypertension. METHOD: Hypertension was induced in the male Sprague Dawley rats by aortic banding just above the left kidney. Relaxation or contraction following cumulative addition of acetylcholine (Ach, 1 x 10(-8) to 1 x 10(-5) M) or phenylephrine (PE, 1 x 10(-8) to 1 x 10(-5) mol/l) was studied in the aortic rings obtained from sham operated normotensive, hypertensive and captopril pretreated rats. Ach and PE responses were taken in the presence or absence of NO synthase inhibitor (L-NAME; 1 x 10(-5) and 1 x 10(-4) mol/l). Spontaneous release of NO from the aortic rings was evaluated by studying the inhibition of adenosine diphosphate stimulated platelet aggregation, while superoxide radicals were estimated by cytochrome c reduction method. RESULTS: Ach induced vasorelaxation in PE precontracted rings was impaired following 8 wk after aortic banding, while spontaneous release of NO remained unaffected. Captopril pretreatment restored the aortic ring responsiveness to Ach. An increase in the superoxide radical generation and PE induced contraction following L-NAME treatment in the hypertensive rat aortic rings was observed. CONCLUSION: Attenuation in the Ach induced NO release and augmentation in the superoxide radical generation seems to play an important role in the modulation of vasoreactivity following renal hypertension in rats.

Acetylcholine↗
PubMed1998

Susceptibility status of malaria vectors to insecticides in India.

The use of chemical insecticides for control of malaria vector populations continues to be the mainstay of malaria control strategy in India. Monitoring vector susceptibility to chemical insecticides is an important activity under the National Malaria Eradication Programme to ensure judicious and effective use of chemical Insecticides. 72 entomological zones were established under NMEP in 1977 for undertaking entomological studies in the malaria problematic areas. These zones have been generating insecticide susceptibility data in respect of the various malaria vectors. In this paper the insecticide susceptibility data, in respect of major vectors of malaria as on 1997, is presented.

Animals↗
PubMed1997

Alterations in the free radical generation and nitric oxide release from rat peripheral polymorphonuclear leukocytes following thrombosis.

The present investigation was undertaken to study the alterations in free radical generation and release of nitric oxide (NO) from polymorphonuclear leukocytes (PMNLs) following thrombosis. Thrombosis was induced in rats by intravenous injection of collagen and adrenaline. PMNLs were separated from rat blood by using dextran sedimentation and Ficoll-Hypaque. Arachidonic acid (AA), formyl methionine leucine phenylalanine (FMLP) and opsonized zymosan (OZ) induced free radical generation was estimated as luminol (LCL) and Lucigenin (LUCDCL) dependent chemiluminescence. PMNLs nitric oxide synthase (NOS) activity and NO release were measured by using [14C] L-Arginine (L-Arg) and oxy-hemoglobin respectively. LCL and LUCDCL responses in rat PMNLs were significantly attenuated following thrombosis. There was no change in the release of myeloperoxidase enzyme (MPO) from PMNLs obtained following thrombosis. PMNLs NOS activity and NO release were also found to be increased after thrombosis. Pretreatment of rat PMNLs with 10 mM L-NAME (NO precursor) or 100 microM sodium nitroprusside (NO donor), resulted in significant reduction of AA induced LCL response. Results obtained indicate that NO release form PMNLs was augmented while free radical generation response was attenuated after the induction of thrombosis.

Animals↗
PubMed1996

Interaction of nitric oxide synthase inhibitors and their D-enantiomers with rat neutrophil luminol dependent chemiluminescence response.

1. Formyl-methionyl-leucyl-phenylalanine (FMLP) or arachidonic acid (AA) induced luminol dependent chemiluminescence (LCL) response of rat polymorphonuclear leukocytes (PMNLs) was found to be inhibited by nitric oxide synthease inhibitors and their D-enantiomers. 2. Rat PMNLs LCL response was inhibited by NG-nitro-L-arginine methyl ester (L-NAME), D-NAME, NG-monomethyl-L-arginine (L-NMMA) or D-NMMA, in a concentration- and time-dependent manner. 3. It was observed that both L- and D-enantiomers of the arginine analogues (1000 microM) did not inhibit AA induced lucigenin-dependent chemiluminescence (LUCDCL) response and cytochrome c reduction, used for estimating the NADPH-oxidase activity in the cells and in the cell free system, respectively. 4. None of the L- and D-enantiomers had any effect on either rat basal PMNLs or AA-induced oxygen consumption. 5. In addition, neither the L nor D-enantiomers of NAME altered either AA-induced release or the activity of myeloperoxidase from rat PMNLs azurophilic granules. 6. The results obtained indicate that the attenuation of the LCL response by L- and D-enantiomers of arginine analogues, is a non-specific effect as there was no inhibition of NADPH-oxidase and MPO activity, MPO release or oxygen consumption. Therefore, the data obtained indicate that these agents should be used with caution to analyse the role of nitric oxide in rat PMNLs LCL response.

Animals↗
PubMed1995

Motor neurone disease like picture in hyperthyroidism.

Five patients of hyperthyroidism with Motor Neurone Disease like picture seen over a span of five years are described. The illness was of over 3 years duration and all patients were males. One patient had even the diagnosis of "MND'. It took 1 to 3 months for disappearance of MND picture with antithyroid drugs. In MND like disease every effort should be made to exclude hyperthyroidism.

Aged↗
PubMed1994

Effect of platelet activating factor antagonists in different models of thrombosis.

Effect of three specific PAF antagonists, SR-27417, BN-50739 and ginkgolide derivative BN-52021 have been evaluated in models of thrombosis in the mouse, rat and cat. Thrombosis in the mouse was induced by intravenous infusion of collagen and adrenaline. In rats it was induced by inserting a metallic wire into the inferior vena cava. In the cat, thrombus formation was assessed in the extracorporeal shunt. All the antagonists offered a dose-dependent protection against pulmonary thromboembolism in mice (1, 3 and 10 mg/kg) and the thrombosis monitored in the extracorporeal shunt in cats (0.3, 1 and 3 mg/kg). In rats, no significant protection was observed with these antagonists even at the highest dose used.

Animals↗
PubMed1994

Modulation of rat peripheral polymorphonuclear leukocyte response by nitric oxide and arginine.

The effect of nitric oxide (NO) on the luminol-dependent chemiluminescence (LCL) response of rat polymorphonuclear leukocytes (PMNLs) was analyzed by using sodium nitroprusside (SNP), a NO donor, and L-arginine (L-arg), a NO precursor. A significant reduction in the LCL intensity was observed in presence of SNP (100 mumol/L) or L-arg (5 or 10 mmol/L) in arachidonic acid (AA) phorbol ester (PMA) and formyl-methionyl-leucyl-phenylalanine stimulated PMNLs. However, opsonized zymosan-induced LCL was not attenuated significantly. Reduction in hydroxyl radical and superoxide generation was also observed in SNP- or L-arg-pretreated cells. D-Arg (10 mmol/L) pretreatment did not inhibit PMNLs' LCL response. Furthermore, methylene blue (5 mumol/L) and L-NG-mono methyl-L-arginine (100 or 300 mumol/L) significantly attenuated the LCL response, as induced by various agonists. Cyclic GMP did not alter the reactive oxygen species generation from rat PMNLs. In addition, AA-induced release of myeloperoxidase, a marker of azurophilic granules, was found to be enhanced in L-arg- (10 mmol/L) pretreated PMNLs. The results suggest that NO inhibits free radical generation from rat PMNLs.

Animals↗
PubMed1994

Alterations in the bioantioxidants following thrombosis.

The role of free radicals in rat thrombosis has been demonstrated by studying its scavenging enzyme system. Changes in the bio-antioxidants (GSH-redox cycle, total thiol groups, vitamins E and C) that also offer protection against the free radicals, have, however, not been studied so far. This investigation was undertaken to understand the involvement of these antioxidants during thrombosis. The tissues investigated following thrombosis were blood, platelets, polymorphonuclear leukocytes (PMNLs), heart, and lung. Glutathione (GSH) content in the platelets was observed to be depleted. However, oxidized glutathione (GSSG) contents in the platelets, PMNLs, and blood remain unaltered. In addition, in the whole blood GSH levels were increased significantly, whereas there was no change in the GSSG level. Activity of glutathione reductase (GR) was decreased significantly in platelets and lungs with an increase in the total thiol groups in the lung homogenate. Activity of Glutathione peroxidase (Gpx) remained unaltered in all the tissues studied. In addition, 24% and 15% decrease in the alpha-tocopherol concentration was observed in thrombocytes and PMNLs, respectively, with no change in the ascorbate levels in these cells. Results of this investigation suggest alterations in the GSH-redox cycle in blood, platelets, and lung after thrombosis in the rat.

Animals↗
PubMed1994

Resting and biting habits of Anopheles sundaicus in Car Nicobar Island.

Resting and biting habits of An. sundaicus were studied in Car Nicobar Island. Results of resting behaviour revealed that although substantial numbers of An. sundaicus rest outdoor, still the species prefer to rest indoors, and much less in human dwellings. High parity rate (73.38%) in An. sundaicus and close contact with man were the factors responsible for high transmission in Car Nicobar. An. sundaicus population in Car Nicobar is susceptible to DDT. Indoor man-biting of An. sundaicus was significantly higher than outdoors and the species showed bimodal biting activity with first peak between 2130 to 2230 hrs and second between 0130 to 0230 hrs. An. sundaicus preferred to feed on people's legs and hands. Due to complex behaviour of An. sundaicus, an integrated approach comprising (i) chemical, (ii) bioenvironmental control, and (iii) personal protection methods was suggested to interrupt malaria transmission in Car Nicobar Island.

Abdomen↗
PubMed1993

Free radical scavenging mechanisms during pulmonary thromboembolism in rats.

In the present investigation alterations in the free radical generating and scavenging enzymes in platelets, neutrophils (PMNLs), heart and lung homogenates following rat pulmonary thromboembolism have been studied. Thrombosis was induced by intravenous infusion of collagen and adrenaline. Levels of malonaldehyde (MDA) were elevated in the PMNLs after thrombosis. Activities of superoxide dismutase (SOD) and catalase (CAT) were found to increase in platelets and PMNLs respectively. However, there was no significant alteration in the lactate dehydrogenase (LDH), lysozyme (LYS), ratio of xanthine oxidase to dehydrogenase (XO/XH) and PMNLs O2- generation before and after thrombosis. Migration of PMNLs following thrombosis was indicated by increased activity of myeloperoxidase (MPO) in the heart. In addition, pretreatment with allopurinol, a xanthine oxidase inhibitor and indomethacin, a cyclooxygenase inhibitor offered protection against thromboembolism induced death/paralysis. Results suggest the involvement of free radicals in thrombosis.

Allopurinol↗
PubMed1993

Feeding preferences of Anopheles sundaicus in Car Nicobar Island.

Host feeding behaviour of An. sundaicus population in Car Nicobar Island was studied by bloodmeal analysis and bait collection. Results indicated the zoophagic nature of the species in different resting sites. However, a human blood index of 0.18 was observed in specimens collected from human dwellings. The highest proportion of females was found positive for porcine antigen. Bait collections also indicated a similar feeding pattern.

Animals↗
PubMed1993

Serum enzyme abnormalities in protein energy malnutrition.

Six serum enzymes, alkaline phosphatase, cholinesterase, lactate dehydrogenase, aspartate aminotransferase, alanine aminotransferase and gamma-glutamyl transpeptidase were studied in 30 cases of protein energy malnutrition (PEM). The mean serum values of alkaline phosphatase, cholinesterase and lactate dehydrogenase in cases of PEM were significantly lower than the controls, lowering being maximum in PEM Grade IV. The mean serum values of aspartate aminotransferase and alanine aminotransferase in patients with PEM were significantly higher than the controls. The mean serum values of gamma-glutamyl transpeptidase showed similar significant rise in all but PEM Grade IV. The degree of increase in the serum values of these three enzymes were maximum in cases with PEM Grade I. These findings suggest that abnormalities in blood levels of these enzymes occur in any form of PEM and these are related to the severity of the disease.

Adolescent↗
PubMed1993

Pulmonary thromboembolism-induced alterations in nitric oxide release from rat circulating neutrophils.

We have earlier reported that neutrophils play an important role in pulmonary thromboembolism. The effect of circulating polymorphonuclear leukocytes (PMNL) isolated from normal and thrombotic rats was, therefore, studied on platelet aggregation in platelet-rich plasma. PMNL inhibited the platelet aggregation in a concentration- and time-dependent manner at 37 degrees C. The platelet aggregation inhibitory response of PMNL was more pronounced in the presence of superoxide dismutase and was abolished by hemoglobin and methylene blue. These observations suggested that the inhibitory effect of PMNL on platelets was mediated by neutrophil-derived relaxing factor. PMNL, obtained after thromboembolism, inhibited the platelet aggregation response more strongly due to an increased release of nitric oxide from them. It is suggested that PMNL play an important role in the regulation of hemostasis.

Adenosine Deaminase↗
PubMed1992

Effect of pulmonary thromboembolism on circulating neutrophils in mice.

The role of free radical generation and its scavenging enzymes in circulating mice polymorphonuclear leukocytes (PMNLs) has been studied following pulmonary thromboembolism. Levels of malonaldehyde (MDA), 02- radical generation, activity of superoxide dismutase (SOD), catalase (CAT), lactate dehydrogenase (LDH), myeloperoxidase (MPO) and lysozyme were estimated in lysed neutrophil preparations. Activities of SOD and CAT were increased in neutrophils, while animals showed 60 +/- 4% thrombocytopenia. Levels of MDA in PMNLs were also elevated significantly following thrombosis. However, there was no significant change in superoxide radical generation, after thrombotic challenge, in mice neutrophils. The present study provides evidence for the involvement of free radicals in mice pulmonary thromboembolism.

Animals↗
PubMedDate not supplied

Manpower utilization in pulse polio immunization.

The present study was conducted in Union Territory of Chandigarh to find out the utilization pattern of manpower engaged in the implementation of Pulse Polio Campaign (PPI) on 7th December, 1997 with the objective to achieve a coverage close to 100% and thereby, eradicating poliomyelitis. Over 100,000 under-five children were expected to participate on PPI day. Out of 240 polio centres established in the Union Territory, 16 were selected by stratified random sampling covering 14,858 children. The observing teams recorded the information about the children and presence of staff members throughout the day between 8.00 a.m. and 5.00 p.m. It was observed that nearly half of the children received the polio drops within the first three hours while only a little over 5% visited polio centres in the last two hours. The average number of manpower varied between 5 and 6 throughout the day (more than the recommended four). The staff posted at urban, rural and slum centres did not visit the houses except for the few volunteers in slums. Unimmunized children should be identified by the staff in last two hours when the load at polio centres is extremely low. Adequate utilization of the full potential of the manpower will help in enhancing the PPI coverage close to 100%.

Child↗