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Biomedical subjects

S N Ray

Publications and source records attributed to S N Ray.

At least 19 recordsLinked to original sources
PubMed2005

Insensitivity to the alpha2-adrenergic receptor blocker yohimbine hydrochloride and occurrence of spontaneous platelet macroaggregation (SPMA) in diabetes.

We report here a study of platelet aggregation in diabetes, induced by epinephrine and its inhibition by yohimbine hydrochloride (YH), an alpha(2)-adrenergic receptor-blocking agent. Interestingly, emergence of spontaneous platelet macroaggregation (SPMA) was observed in six out of 75 cases in the absence of any agonist. The SPMA cases were strongly associated with insensitivity to YH (in contrast with non-SPMA cases) when epinephrine was used as an agonist. We suggest that the observed correlation is a result of over expression of platelet alpha(2)-adrenoceptors in such subjects. The quantitative nature of the effect is supported by the observation that addition of YH at higher concentration (more than 5 microM) led to restoration of the adrenergic receptor-blocking activity of the said agent. Eventually for non-SPMA subjects YH exhibited blocking activity even at lower concentration. The aggregation profile and the platelet morphology of the SPMA cases had distinctive features as compared to microaggregates formed in other diabetic subjects (non-SPMA cases).

Adrenergic alpha-2 Receptor Agonists↗
PubMed2001

Lipid peroxidation associated protein damage in rat brain crude synaptosomal fraction mediated by iron and ascorbate.

In crude synaptosomal fractions from rat brain exposed to iron and ascorbate, enhanced lipid peroxidation (more than 3-fold compared to control), loss of protein thiols up to the extent of 40% compared to control, increased incorporation of carbonyl groups into proteins (more than 4.5-fold compared to control) and non-disulphide covalent cross-linking of membrane proteins have been observed. The phenomena are not inhibited by catalase or hydroxyl radical scavengers like mannitol or dimethyl sulphoxide. However, chain breaking antioxidants like alpha-tocopherol and butylated hydroxytoluene prevent both lipid peroxidation and accompanying protein oxidation. It is suggested that in this system lipid peroxidation propagated by the decomposition of preformed lipid hydroperoxides by iron and ascorbate is the primary event and products of the peroxidation process cause secondary protein damage. In view of high ascorbate content of brain and availability of several transition metals, such ascorbate mediated oxidative damage may be relevant in the aetiopathogenesis of several neurodegenerative disorders as well as ageing of brain.

Animals↗
PubMed1995

Significance of nuchal cord.

Perinatal events of 180 babies with nuchal cord (umbilical cord entanglement around foetal neck) over one year have been studied. The incidence of nuchal cord was 5.74% of all hospital deliveries. More than one third (39%) of them had tight nuchal cord (TNC) and 61% had loose nuchal cord (LNC). Babies with TNC were more frequently met with foetal distress (51%), prolonged second stage (11%), non-toxaemic accidental haemorrhage (7%) and operative delivery (56%) when compared to babies with LNC and controls (without nuchal cord). Nearly one fourth (24%) of the babies with TNC were born as small for date, had birth asphyxia (61%) and 8.5% died during perinatal period. Perinatal outcome was adversely affected by TNC in comparison to LNC and controls.

Female↗
PubMed1978

Effect of trimethoprim-sulphamethoxazole on vibrio clearance in cholera (El Tor): a comparative study.

The efficacy of trimethoprim-sulphamethoxazole (TMP-SMX) has been compared with that of tetracycline and chloramphenicol in 175 bacteriologically confirmed cases of cholera admitted to the Infectious Diseases Hospital Delhi. Vibrio cholerae, biotype El Tor, serotype ogawa, were isolated from all the patients. TMP-SMX showed greater in vitro inhibition and earlier eradication from the intestinal tract and is recommended as a suitable vibriocidal agent against cholera.

Chloramphenicol↗
PubMed1977

Undernutrition and immunity: smallpox vaccination in chronically starved, undernourished subjects and its immunologic evaluation.

This study illustrates the specific immune response of chronically starved, undernourished adults after inoculation of live smallpox vaccine. It produced no adverse effect, and major vaccinial reaction was observed in all. 63% of undernourished individuals showed a fourfold or greater rise of the neutralizing antibody titre. In contrast, only 9% of normal healthy subjects could show similar response. However, the prevaccination titre was much lower in the undernourished group than in the control group, and the postvaccination titre also remained persistently lower in the former than in the latter group. Furthermore, whereas the specific humoral antibody response in the undernourished subjects was partially adequate, the development of specific cellular immunity against vaccinia was remarkably poor, indicating that smallpox vaccination in these subjects might be less effective against variola infection. This observed profound effect of chronic starvation and severe undernutrition on the immune apparatus was possibly multifactorial, protein depletion being the most important factor, as proved by the significantly low serum albumin level. The significantly low peripheral blood lymphocyte count and spectacular unresponsiveness to many antigens in these individuals suggested profound depression of the thymolymphatic system. Further, the significantly low level of neutralizing antibody in the malnourished subjects suggested that the formation of this protective antibody might necessitate the cooperation of T lymphocytes.

Adult↗