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Biomedical subjects

V Kapoor

Publications and source records attributed to V Kapoor.

At least 55 records · Page 3Linked to original sources
PubMed1997

Distribution of D-amino acid oxidase (DAO) activity in the medulla and thoracic spinal cord of the rat: implications for a role for D-serine in autonomic function.

The activity and regional distribution of D-amino acid oxidase (DAO), an enzyme that inactivates D-serine, were examined in the medulla and spinal cord of the rat by biochemical and histochemical procedures. DAO activity was noticeably low or absent in the nucleus of the solitary tract, ventrolateral medulla and intramediolateral cell column of the spinal cord. This may be indicative of a neuromodulatory role for endogenous D-serine (at the NMDA-glycine site) in in the central control of blood pressure.

Amino Acid Oxidoreductases↗
PubMed1996

Altered responsiveness of medullary depressor neurones to L-glutamate and D-serine in SHR rats.

We have investigated the effects of microinjection of L-glutamate, D-serine and glycine into the caudal ventrolateral medulla (CVLM) of spontaneously hypertensive (SHR) and Wistar Kyoto (WKY) rats. In SHR the depressor responses to L-glutamate were significantly enhanced compared to WKY rats, while those to the NMDA-glycine site agonists, D-serine and glycine (in the presence of strychnine) were significantly diminished. Depressor responses to NMDA and D-serine could be blocked with 5-fluro-indole-2-carboxylic acid (FICA, an NMDA-glycine site antagonist). In support of our previous findings, the larger responses of NMDA-glutamate site agonists and smaller responses of NMDA-glycine site agonists in SHR, may suggest that SHR have reduced levels of the endogenous glutamate antagonist, kynurenic acid.

Animals↗
PubMed1996

The paradox of the StatCap carbon dioxide indicator. An experimental evaluation of rebreathing.

The StatCap semiquantitative carbon dioxide detector was evaluated in an experimental setting. The monitor underread at progressively higher concentrations of carbon dioxide. During simulated rebreathing, progressive increases in inspired carbon dioxide resulted in the StatCap readings decreasing. It is recommended that the StatCap be used with caution in circumstances where rebreathing may occur, for example, during manual ventilation with an Ayre's T-piece.

Carbon Dioxide↗
PubMed1996

The 'small spleen' in malaria.

A cardinal feature of malaria, splenomegaly, is usually absent in adult patients who have already suffered from falciparum malaria or who are natives of an endemic falciparum zone. This is an attribute of the past episode of clinical or sub-clinical malaria which usually results in regression of the splenic size to below-normal. An ultrasonographic evaluation of spleens was done in 90 healthy adult males, who had suffered from vivax (n = 28) or falciparum (n = 25) malaria in the past, except the controls (n = 22) and natives from an endemic falciparum area (n = 15) who never suffered from malaria. Their ultrasonographic details of spleens, including the size, were compared. Besides other conspicuous differences in the ultrasonographic picture, spleen size was found significantly decreased (p < 0.01) in the group who had been affected by P. falciparum malaria; the smallest measured 7.8 cms. In P. vivax group the decrease was not significant (p < 0.1), but was highly significant in inhabitants of endemic falciparum region (p < 0.001). The present study establishes the 'Small Spleen' and looks at echotexture pattern variations thereof for the first time.

Adult↗
PubMed1994

Kynurenic acid, an endogenous glutamate antagonist, in SHR and WKY rats: possible role in central blood pressure regulation.

1. Kynurenine aminotransferase catalyzes the conversion of kynurenine to kynurenic acid, an endogenous antagonist of excitatory amino acid receptors. The kynurenic acid content and kynurenine aminotransferase activity was measured in micro-dissected regions of spontaneously hypertensive rats (SHR) and their normotensive controls (Wistar-Kyoto rats: WKY). 2. Of the brain regions examined the highest kynurenine aminotransferase activity was found in the medulla followed by the olfactory bulb and the cerebellum, with the spinal cord showing the lowest activity. 3. All samples from SHR showed greatly reduced kynurenine aminotransferase activity compared to WKY. These reductions were most pronounced in the medulla and spinal cord, approximately 45-55%, and lowest in the cerebellum and olfactory bulbs, approximately 25-30%. 4. The kynurenic acid content of the rostral and caudal medulla as well as the spinal cord was also significantly lower in SHR. 5. These results suggest that there may be a deficiency in the kynurenic acid content and kynurenine aminotransferase activity in the SHR. 6. Given the accumulating evidence of the importance of medullary glutamatergic pathways in the control of blood pressure, as well as the higher sensitivity of cardiovascular neurons of SHR to applied glutamate, it seems possible that endogenous kynurenic acid in the brain may play a role in the control of blood pressure and the pathogenesis of experimental hypertension in the SHR.

Animals↗
PubMed1993

Blood transfusion and immunomodulation: a possible mechanism.

To induce an immunogenic response in vivo, an antigen-presenting (stimulator) cell must present both antigen-specific (class II MHC) and an accessory signal to the CD4 T cell. Failure to express the accessory signal has been shown in vitro to induce a state of specific unresponsiveness (anergy) in the T cell. We have shown that although stimulator cells in blood continue to express class II MHC molecules during refrigerated storage, their ability to present the accessory signal diminishes, reaching zero in all units tested by about 13 days. This implies that blood in excess of 2 weeks old should not alloimmunize but could induce some degree of immunosuppression. UV-B irradiation and, to a lesser extent, gamma-irradiation, were also shown to inhibit expression of the accessory signal by stimulator cells in blood.

Antibodies, Monoclonal↗
PubMed1993

The effect of aspirin, paracetamol and analgin on pharmacokinetics of chloroquine.

The effect of Aspirin, paracetamol and analgin on the kinetic profile of a single oral dose of chloroquine was studied in 8 healthy subjects. Aspirin did not alter the kinetic parameters of chloroquine whereas paracetamol and analgin significantly enhanced the Cmax and AUC0-alpha of chloroquine (P < 0.01, < 0.05 respectively).

Acetaminophen↗
PubMed1993

A randomized prospective study of a hydroactive dressing vs conventional treatment after shave biopsy excision.

BACKGROUND AND DESIGN: Fifty shave biopsy sites were prospectively randomized to treatment with either a hydroactive dressing or conventional therapy (bacitracin plus Band-Aid). Time to complete epithelialization, pain, infection, and convenience of the therapy were assessed. RESULTS: There was no significant difference between the two dressings with regard to time to heal, wound infection rate, or pain. However, patients preferred the hydroactive dressing because of convenience. CONCLUSION: Hydroactive dressings did not accelerate healing compared with conventional therapy, but may facilitate wound management because of convenience and time savings in dressing changes.

Bacitracin↗
PubMed1992

Ventral medulla stimulation increases blood pressure and spinal cord amino acid release.

Microdialysis in combination with HPLC and fluorescence detection was used to measure the release of endogenous amino acids from the region of the intermediolateral cell column of rat thoracic spinal cord in response to electrical stimulation of the rostral ventrolateral medulla (RVLM). Stimulation of the RVLM led to a marked rise in blood pressure (74 +/- 6 mm Hg) accompanied by an immediate increase in the release of glutamate (80%) and aspartate (50%). Small increases in the release of glycine and taurine were found, but there were no changes in alanine and serine release. These results suggest that the RVLM pressor pathway to the thoracic spinal cord may use, at least in part, excitatory amino acids as neurotransmitters, supporting previous pharmacological and neuroanatomical investigations of this bulbospinal pathway.

Alanine↗
PubMed1992

Kainic acid injection in NTS evokes hypertension and c-fos expression in spinal cord.

Kainic acid injected into rat nucleus tractus solitarius (NTS) caused a slowly developing hypertension, with a 2-fold increase in Fos-immunoreactive (Fos-IR) nuclei in the area of the presympathetic bulbospinal neurons in the rostral ventrolateral medulla (RVLM) and a widespread activation of sympathetic preganglionic neurons (SPN) in the spinal cord, particularly in the mid to lower thoracic cord. The highest segmental concentration of Fos-IR SPN was in T8, with Fos-IR nuclei increased 12-fold compared with the vehicle injected group. More than 60% of retrogradely labelled sympathoadrenal neurons in T8 were Fos-IR after kainic acid injection, consistent with the 60-fold increases in plasma adrenaline levels observed in these rats.

Animals↗