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Biomedical subjects

K Singh

Publications and source records attributed to K Singh.

At least 307 records · Page 17Linked to original sources
PubMed1995

Hyperaggregation of platelets in intestinal tuberculosis: role of platelets in chronic inflammation.

Eighty-eight percent (38/43) patients of intestinal tuberculosis showed significant hyperaggregation of platelets (P < 0.001). Serum and plasma from 15 patients when incubated with normal platelets caused hyperaggregation. Gel filtered platelets from 2 patients suspended in normal plasma showed hyperaggregation of platelets with arachidonic acid. Tubercular protein had no effect on platelet aggregation. A role of hyperactive platelets in chronic inflammatory response is discussed.

Adolescent↗
PubMed1995

Fine structure and primary sensory projections of sensilla located in the sacculus of the antenna of Drosophila melanogaster.

Sensilla lining the inner walls of the sacculus on the third antennal segment of Drosophila melanogaster were studied by light and transmission electron microscopy. The sacculus consists of three chambers: I, II and III. Inside each chamber morphologically distinct groups of sensilla having inflexible sockets were observed. Chamber I contains no-pore sensilla basiconica (np-SB). The lumen of all np-SB are innervated by two neurons, both resembling hygroreceptors. However, a few np-SB contain one additional neuron, presumed to be thermoreceptive. Chamber II houses no-pore sensilla coeloconica (np-SC). All np-SC are innervated by three neurons. The outer dendritic segments of two of these neurons fit tightly to the wall of the lumen and resemble hygroreceptor neurons. A third, more electron-dense sensory neuron, terminates at the base of the sensillum and resembles a thermoreceptor cell. Chamber III of the sacculus is divided into ventral and dorsal compartments, each housing morphologically distinct grooved sensilla (GS). The ventral compartment contains thick GS1, and the dorsal compartment has slender sensilla GS2. Ultrastructurally, both GS1 and GS2 are double-walled sensilla with a longitudinal slit-channel system and are innervated by two neurons. The dendritic outer segment of one of the two neurons innervates the lumen of the GS and branches. On morphological criteria, we infer this neuron to be olfactory. The other sensory neuron is probably thermoreceptive. Thus, the sacculus in Drosophila has sensilla that are predominantly involved in hygroreception, thermoreception, and olfaction. We have traced the sensory projections of the neurons innervating the sacculus sensilla of chamber III using cobaltous lysine or ethanolic cobalt (II) chloride. The fibres project to the antennal lobes, and at least four glomeruli (VM3, DA3 and DL2-3) are projection areas of sensory neurons from these sensilla. Glomerulus DL2 is a common target for the afferent fibres of the surface sensilla coeloconica and GS, whereas the VM3, DA3 and DL3 glomeruli receive sensory fibres only from the GS.

Animals↗
PubMed1995

Duodenal ulcer. Calcium status in isolated parietal cells.

Although the etiology of duodenal ulcer is not known, its treatment with drugs that reduce acid secretion is well accepted. The central role of calcium in stimulus-secretion coupling resulting in acid secretion by gastric parietal cells is documented. However, the status of intracellular calcium in gastric parietal cells in the basal state in patients with duodenal ulcer is not known. Multiple endoscopic gastric mucosal biopsies from the corpus of the stomach of 52 patients were processed and isolated parietal cells were studied. Intracellular calcium was estimated using fura-2-acetoxymethyl ester. Influx and efflux were determined by using radioactive calcium. Acridine orange retention was used to assess acid production. Only calcium influx at 20 min was significantly (P < 0.01) more in patients with duodenal ulcer as compared to the control group. There was no difference between the groups in calcium influx at 0 and 60 min; calcium efflux at 0, 20, and 60 min; intracellular free calcium and acid secretion. We conclude that in the unstimulated state calcium homeostasis in isolated parietal cells of patients with duodenal ulcer shows only a minimal difference as compared to controls.

Adult↗
PubMed1995

Pattern of hepatitis A and hepatitis B virus markers in cases of acute sporadic hepatitis and in healthy school children from north west India.

The pattern of viral markers in acute sporadic hepatitis in 329 children and those in 334 healthy school children from North West India were studied. Hepatitis A was found to be the commonest infection in sporadic cases (78 per cent). Of these, 86 per cent were under 10 years and 50 per cent less than 5 years of age. Hepatitis B was positive in 8 per cent, non-A non-B in 13 per cent, A as well as B in 1 per cent, and none had Delta virus infection. Viral markers in healthy school children showed anti-HAV IgG positivity in 96 and 85 per cent in those belonging to low and high socio-economic groups, respectively, indicating past infection. HBsAg was positive in 1 per cent of cases. Viral hepatitis is an important public health problem in children and warrants active immunization.

Adolescent↗
PubMed1995

Tangential excision and skin grafting for ash burns of the foot in children: a preliminary report.

In India, isolated burns of the feet in children are common, but people seldom seek specialized treatment. These burns result from careless disposal of hot ash or embers after cooking or religious functions. Five children were treated for acute burns of the feet, with tangential excision and skin grafting. Early surgical treatment of these seemingly innocuous burns offers distinct advantages, i.e., avoidance of painful dressings, the need for reconstructive procedures, and reduced hospital stay. It also helps in early return to childhood activities and normal growth of the foot. A new concept of excising deep dermal burns of the "sole" is emphasized to preserve sensate unburned dermis.

Burns↗
PubMed1995

A study of hepatitis delta virus infection in patients with acute and chronic liver disease from northern India.

To assess the prevalence of hepatitis delta virus (H delta V) in northern India, 204 adult patients with acute and chronic liver disease who were positive for hepatitis B virus (HBV) markers were screened for anti-H delta V antibody by enzyme-linked immunosorbent assay (ELISA). Anti-H delta V antibodies were positive in 29 (14.2%) patients. The incidence of H delta V infection was higher (21.4%) in patients with chronic liver disease when compared with those with acute viral hepatitis (10.7%) (P < 0.05). H delta V antibodies were positive in 16.6% of patients with fulminant hepatic failure (FHF) and in 25% of cases with hepatocellular carcinoma. Co-infections were significantly higher in acute hepatitis (80%), while superinfections predominated (66.7%) in chronic liver disease (P < 0.05). Our data show that H delta V is endemic in northern India and should be considered a major health problem.

Acute Disease↗
PubMed1995

Surgical treatment of transposition of great arteries with interrupted pulmonary artery: a rare association of embryopathies.

The first case of TGA with VSD, ASD, and interrupted LPA and its successful surgical treatment is being reported along with a review of the relevant literature. The dominant presenting clinical features have been explained and an attempt has been made to explain the paucity of records in regard to this embryopathy. An arterial switch for TGA and a glutaraldehyde pretreated autologous pericardial roll for repair of interrupted LPA were carried out. Pre- and postoperative hemodynamics and angiography data are also presented.

Ductus Arteriosus, Patent↗
PubMed1995

Inhibitory effects of melatonin on testosterone but not on androstenedione production during winter in the vespertilionid bat, Scotophilus heathi.

The possible effects of melatonin on testosterone and androstenedione production in vitro by testes of wild-caught bats, Scotophilus heathi, during different reproductive phases were investigated. Bats were captured during reproductive quiescent (April-August), recrudescent (September-October), breeding (November-February), and winter dormancy (late December-January) phases. Testes were incubated in media-199 for 2 h at 37 degrees C with luteinizing hormone (LH) and with or without melatonin. Melatonin had no effect on LH-induced testosterone (T) or androstenedione (A) production during the quiescent, recrudescent, and breeding phases. However, it significantly (P < 0.05) suppressed LH-induced T production but had no effect on A during winter dormancy. Testicular 17 beta-hydroxy steroid dehydrogenase (17 beta-HSD) activity was then measured in the testes from bats trapped during quiescence, breeding, and winter dormancy. Interestingly, melatonin along with LH caused suppression of 17 beta-HSD activities (3.56 +/- 0.03 unit/min/mg protein) when compared with levels of LH treated testes (7.10 +/- 1.15 unit/min/mg protein) during winter dormancy, while it had no significant effect on 17 beta-HSD activity during quiescence and breeding phases. These results suggest that in S. heathi, melatonin during winter dormancy suppresses LH-induced T production by the testes via the suppression of 17 beta-HSD activity. This may be the reason for the decline in testicular activity during winter dormancy.

17-Hydroxysteroid Dehydrogenases↗
PubMed1995

Survival and drug discontinuation analyses in a large cohort of methotrexate treated rheumatoid arthritis patients.

OBJECTIVES: To determine the probability of drug continuation in a large cohort of methotrexate treated rheumatoid arthritis (RA) patients, the reasons for discontinuation of methotrexate, the overall survival of the members of this cohort, and the causes of death in these patients. METHODS: Yearly follow up was conducted in methotrexate treated RA patients who formed a cohort between 1981 and 1986 at a tertiary care centre. The probability of drug continuation and the patients' survival were calculated using standard statistical procedures; standardised mortality ratios were calculated using death certificate data and USA general population and mortality tables. RESULTS: The probability of methotrexate continuation at 10 years from the time the first members entered the cohort was 30%. Toxicity (and its severity) was the most frequent cause of discontinuing methotrexate. The cumulative probability of survival was 85% for women and 45% for men. A greater than expected number of deaths from infections was observed, but the number of deaths from cancer and cardiovascular diseases were within the range expected. CONCLUSIONS: Toxicity remains the most common cause for methotrexate discontinuation. Survival was comparable to that of other RA cohorts. Methotrexate may be implicated as an associated factor in the deaths from infections.

Arthritis, Rheumatoid↗
PubMed1995

Effect of chronic ethanol administration and dietary protein regimens on intestinal absorption of macromolecules in rats.

The effect of feeding ethanol daily for 40 days has been studied on intestinal absorption of bovine serum albumin (BSA) and gamma-globulin (IgG) in rats fed a low (8%) protein (LP) or a high (30%) protein (HP) diet. Feeding the LP diet enhanced the tissue uptake of BSA (p < 0.05) and absorption of BSA and IgG into serum (p < 0.001) as compared with controls. Feeding the HP diet also augmented the uptake of IgG (p < 0.001) by the intestinal tissue and significantly enhanced serum levels of BSA and IgG. Ethanol feeding to rats for 40 days enhanced the uptake of BSA and IgG (24-84%) and their absorption into serum (p < 0.001) as compared with the controls. Ethanol administration to rats fed LP or HP diets did not alter the uptake of these proteins as compared with their respective controls. Luminal degradation of BSA and IgG was higher in ethanol-administered (48-50% and 36-39%, respectively) and LP-fed rats (50 and 38%, respectively). It was reduced by 17-21% in HP-fed rats as compared with the control group. This indicated that the observed increase in protein absorption is not related to the luminal degradation of the proteins under these conditions. These findings suggest that the absorption of macromolecules from intestine in response to ethanol feeding is influenced by the dietary status of the animals.

Animals↗
PubMed1995

A clinical study of clozapine treatment and predictors of response in a Canadian sample.

OBJECTIVE: To study the clinical response to clozapine in patients with refractory schizophrenia. METHOD: Open trial of clozapine in 61 consecutively-treated patients. RESULTS: Following clozapine, the level of function of patients was improved relative to admission (p = 0.0001) and to the highest level in the previous year (p = 0.0001). Severity of illness was decreased (p = 0.0001). Overall, 31% of the patients were classified as responders to clozapine and the responders were all identified by 32 weeks of treatment. Poor functioning in the previous year was associated with less favourable response. At a mean interval of 26 months following discharge, 72% of the patients were continuing clozapine treatment. CONCLUSIONS: This open trial of patients who were treated consecutively indicates a comparable degree of response to clozapine as observed in controlled clinical trials, and that level of functioning in the previous year was the best predictor of response.

Adolescent↗