Search PubMed⌕ Search

Biomedical subjects

S Kumar

Publications and source records attributed to S Kumar.

At least 1,765 records · Page 98Linked to original sources
PubMed1989

Coping with symptoms of relapse in schizophrenia.

A pilot study is reported of 30 chronic schizophrenic patients at the psychiatric out-patient facility of Government General Hospital, Madras, India. The objectives of the study were to assess the patients' perception of prodromata of relapse and their coping mechanisms. Patients were questioned on these aspects, using a semi-structured interview guide. The study showed a high degree of perception of prodromal signs amongst the cohort. Only 4 patients were unable to perceive any prodromata of relapse. Most commonly noted prodromal symptoms were disturbed sleep and slowness and underactivity. Patients had also resorted to various coping measures such as internal dialogue and talking to a close relative or friend. The study has clearly proved that Indian schizophrenic patients are perceptive of prodromata of relapse and developed self-help methods. These methods, if properly identified, could be incorporated in psychosocial intervention programmes.

Adaptation, Psychological↗
PubMed1989

The effect of hyaluronate and its oligosaccharides on endothelial cell proliferation and monolayer integrity.

Hyaluronidase treatment of hyaluronic acid produced a series of oligosaccharides. Those between 3 and 16 disaccharides in length stimulated angiogenesis in vivo and the proliferation of tissue cultured endothelial cells in vitro. This effect appears to be cell type specific, as no stimulation of fibroblasts or smooth muscle cells was observed. Endothelial cells were found to endocytose both high- and low-molecular-mass hyaluronate, which might be receptor mediated. Fibroblasts and smooth muscle cells, cultured under the same conditions, showed negligible uptake of hyaluronate. Thus, the cell-specific effects may be due to the differences in internalization of hyaluronate. High-molecular-weight hyaluronate both inhibited endothelial cell proliferation and disrupted newly formed monolayers. These data are consistent with the ability of hyaluronate to inhibit new blood vessel formation in vivo and also suggest that hyaluronate metabolism plays a pivotal role in the regulation of angiogenesis.

Animals↗
PubMed1989

Tuberculous abscess of the brain stem.

Three cases of tuberculous abscess of the brain stem were treated with excision of the abscess supplemented with antitubercular therapy for 12 to 18 months. The lesions were frankly purulent and tubercle bacilli were demonstrated in the pus. A computed tomography scan demonstrated the site and extent of the lesion. Two of three patients developed the abscess during the course of antitubercular therapy for associated tubercular lesions. In spite of modern antitubercular treatment the abscess did not resolve and surgical excision had to be employed as a curative treatment.

Abscess↗
PubMed1989

The effects of dieldrin, dimethoate and permethrin on Tetrahymena pyriformis.

The effects of three insecticides, dieldrin, dimethoate and permethrin, on the growth of a holotrichous ciliate, Tetrahymena pyriformis, were studied for 5 days. The ciliate was very sensitive to dieldrin and dimethoate. Both these insecticides produced approximately 81% and 84% inhibition of growth within two days. Dieldrin caused rounding of cells, while dimethoate induced cell lysis. Dimethoate also triggered a general mucocyst discharge. Of the three insecticides, permethrin was the least toxic and induced no morphological alterations.

Journal Article↗
PubMed1989

Role of GSSG-reductase and a thiol oxidant diethylmaleate (DEM) in skin tumorigenesis induced by jute batching oil.

Single topical application of jute batching oil (JBO-P) elevated the status of enzyme GSSG-reductase in mouse skin and multiple applications produced a persistent increase in the enzyme levels. Also an increase in NADPH-dependent GSSG-reductase activity was registered after single topical application of known carcinogenic polyaromatic hydrocarbons (PAHs), e.g. benzo(a)pyrene (BaP), 7,12-dimethyl-benzanthracene (DMBA) and 3-methylcholanthrene (3-MC). This suggests that the change in GSSG-reductase activity induced by JBO-P is intrinsic to its tumorigenic activity rather than the toxic effect of the oil. Pretreatment of mouse skin with diethylmaleate (DEM), an SH-inactivating agent, increases the latent period of JBO-P induced tumorigenesis. No tumour was recorded in animals belonging to Group IV (DEM + JBO) while in animals belonging to Group II (JBO-P alone) 100% tumorigenesis was recorded during the period of study (i.e. up to 20 wk).

Animals↗
PubMed1989

Comparative metabolism of benzo[f]quinoline by liver microsomes from brown bullheads and rats.

1. Liver microsomes from rats were considerably more active in metabolizing benzo[f]quinoline (B f Q) than those from brown bullheads (Ictalurus nebulosus). 2. The main B f Q metabolites formed by both rat and brown bullhead liver microsomes were qualitatively similar and included B f Q-7,8-dihydrodiol, B f Q-9,10-dihydrodiol, B f Q-N-oxide, 7-hydroxy B f Q, and 9-hydroxy B f Q. 3. The liver microsomes from control brown bullheads and rats metabolized B f Q primarily at the 7,8-and 9,10-positions, respectively, whereas in the case of microsomes from 3-methylcholanthrene (3-MC)-treated rats or brown bullheads, the major site of metabolic attack was the 7,8-position. 4. A 3-MC-type of cytochrome P-450 appears to be primarily responsible for the oxidation of B f Q by control brown bullhead liver microsomes, whereas a phenobarbital-inducible type of cytochrome P-450 seems to be involved in the metabolism of B f Q by control rat liver microsomes.

Animals↗
PubMed1989

Culture of Rhinosporidium seeberi: preliminary report.

Every year 400 to 450 cases of Rhinosporidium are reported from Trivandrum Medical College. Twenty-five swabs were collected from patients suffering from Rhinosporidiosis and cultured in standard media. Positive results were obtained in 23 cases. The conidia produced from the colony were compared with the structures obtained from the patient material. Light microscopy using histopathological techniques were used. The consistent appearance of the organism in patient material, the repeatability of growth in subcultures and the negative growth in controls indicated that the organism grown in culture is the causative agent of the disease. The effect of parameters like pH, temperatures, etc, were also studied.

Culture Media↗
PubMed1989

Prognostic relevance of DNA content in childhood renal tumours.

The DNA content of paraffin embedded tumour specimens from 100 children with kidney tumours was studied by flow cytometry. Data of adequate quality were obtained from 93 cases comprising 67 Wilms' tumours with a favourable histology (FH), 12 Wilms' tumours with unfavourable histology (UH) (pleomorphic), 8 bone-metastasising renal tumours of childhood (BMRTC) and 6 rhabdoid renal tumours. Only 4.5% FH compared with 75% UH Wilms' were aneuploid (P less than 0.001). Although BMRTC and rhabdoid tumours are associated with poor prognosis, there were no examples of aneuploidy in these tumours. The proliferation index was found to be of no prognostic value. Staging and ploidy were not correlated with each other in any of the various histological types of renal tumours studied.

Child↗
PubMed1989

Time to stop counting the tablets?

We attempted to assess compliance using both a pharmacologic indicator (low-dose phenobarbital) and a return tablet count in 225 patients who were taking part in three separate studies. There were 216 patients (96%) who kept a follow-up appointment after 28 days; 161 patients appeared to have good compliance (90% to 109%) by return tablet count. Of these 161 patients, 51 (32%) had plasma phenobarbital concentrations (corrected for dose and weight) that were less than 90% of the lowest value previously found in normal volunteers, which suggested poorer compliance. When compared with the age-related volunteer values, 77 (48%) had values that were less than 90% of the lowest volunteer value. There were 6 of 10 patients with apparently excessive (greater than or equal to 110%) compliance by return tablet count and 4 of 12 who failed to return their container who also had phenobarbital concentrations that were less than 90% of the lowest volunteer value. We concluded that return tablet count grossly overestimates compliance.

Drug Therapy↗
PubMed1989

T cell receptor gene rearrangement and expression in ataxia-telangiectasia B lymphoblastoid cells.

Immunoglobulin and T cell receptor gene probes have been used to investigate cell lineage and monoclonality in lymphoid malignancies. In the present study we have used T cell receptor beta- and gamma-chain gene probes to screen for abnormal rearrangements of these genes in B lymphoblastoid cells from patients with ataxia-telangiectasia (A-T). No rearrangement of either gene was observed but deletion of a beta-chain gene allele is described for one A-T cell line. Expression of mRNA hybridizing to the beta-chain gene probe was demonstrated for two A-T homozygotes (brother and sister) as well as for their mother (heterozygote). This transcript was found to be truncated in all three cases.

Ataxia Telangiectasia↗
PubMed1989

Human placenta protein-tyrosine-phosphatase: amino acid sequence and relationship to a family of receptor-like proteins.

The amino acid sequence of the cytosolic human placenta protein-tyrosine-phosphatase 1B (PTPase 1B; protein-tyrosine-phosphate phosphohydrolase, EC 3.1.3.48) has been determined. It consists of a single chain of 321 residues with an N-acetylated N-terminal methionine and an unusually proline-rich C-terminal region. The enzyme is structurally related to the two cytoplasmic domains of both the leukocyte common antigen CD45 and LAR, a CD45-like molecule with an external segment that resembles a neural cell adhesion molecule. A low molecular weight protein encoded by a cDNA clone from T cells also shows extensive sequence similarities. The present study defines homologous domains common to this diverse family of PTPases that includes both soluble and receptor-like transmembrane forms. The cysteinyl residues 121 and 215 of PTPase 1B are conserved among all members of the family and are candidates for involvement in catalysis since PTPase 1B is inactivated by thiol modifying reagents. Two segments rich in positively charged residues (residues 33-47 and 227-238) may provide sites of interaction with inhibitory anionic polymers such as heparin or poly(Glu/Tyr).

Amino Acid Sequence↗
PubMed1989

In vitro galactosylation of a 110-kDa glycoprotein by an endogenous cell surface galactosyltransferase correlates with the invasiveness of adrenal carcinoma cells.

We have examined the role of a cell surface galactosyltransferase, laminin, and laminin-binding protein (receptor) in the invasion of clonal derivatives of a murine adrenal carcinoma cell line. Although a 10-fold variation was found in the ability to invade a reconstituted basement membrane matrix, levels of intracellular laminin and the laminin-binding protein were shown to be present and secreted equally in all lines. Of the eight lines tested, seven showed a correlation between invasion and the incorporation of [3H]galactose from UDP-[3H]galactose into a 90- to 110-kDa protein. One noninvasive line (clone HSR), however, retained high galactosyltransferase activity yet could not galactosylate the endogenous 90- to 110-kDa substrate. Interestingly, this clone was unable to attach to laminin. Although high galactosyltransferase activity can be consistent with cells of high invasiveness, our results suggest that the galactosylation status of a 90- to 110-kDa Y1 cell surface glycoprotein is most indicative of invasion potential.

Adrenal Gland Neoplasms↗
PubMed1989

Differential regulation of oligodendrocyte markers by glucocorticoids: post-transcriptional regulation of both proteolipid protein and myelin basic protein and transcriptional regulation of glycerol phosphate dehydrogenase.

During neonatal development glucocorticoids potentiate oligodendrocyte differentiation and myelinogenesis by regulating the expression of myelin basic protein, proteolipid protein, and glycerol phosphate dehydrogenase (sn-glycerol-3-phosphate: NAD+ 2-oxidoreductase, EC 1.1.1.8). The actual locus at which hydrocortisone exerts its developmental influence on glial physiology is, however, not well understood. Glycerol phosphate dehydrogenase is glucocorticoid-inducible in oligodendrocytes at all stages of development both in vivo and in vitro. In newborn rat cerebral cultures, between 9 and 15 days in vitro, a 2- to 3-fold increase in myelin basic protein and proteolipid protein mRNA levels occurs in oligodendrocytes within 12 hr of hydrocortisone treatment. Immunostaining demonstrates that this increase in mRNAs is followed by a 2- to 3-fold increase in the protein levels within 24 hr. In vitro transcription assays performed with oligodendrocyte nuclei show an 11-fold increase in the transcriptional activity of glycerol phosphate dehydrogenase in response to hydrocortisone but no increase in transcription of myelin basic protein or proteolipid protein. These results indicate that during early myelinogenesis, glucocorticoids influence the expression of key oligodendroglial markers by different processes: The expression of glycerol phosphate dehydrogenase is regulated at the transcriptional level, whereas the expression of myelin basic protein and proteolipid protein is modulated via a different, yet uncharacterized, mechanism involving post-transcriptional regulation.

Animals↗
PubMed1989

Combined upper and lower gastrointestinal endoscopy: a prospective study in alcoholic and nonalcoholic cirrhosis.

Upper gastrointestinal hemorrhage is one of the more important complications of cirrhosis. Most of the available data regarding the prevalence of upper and lower gastrointestinal sites of bleeding in cirrhotic patients have been obtained in individuals with alcoholic cirrhosis evaluated in the course of an acute gastrointestinal bleeding episode. Few data exist, however, as to the prevalence of either potential bleeding sites or of normal endoscopic findings in hemodynamically stable individuals with cirrhosis of any etiology. Five hundred ten cirrhotic subjects, who were evaluated for possible liver transplantation (OLTx) between January 1985 and June 1987, were included in this study. Seventy-five had alcoholic cirrhosis and 435 had nonalcoholic cirrhosis of various etiologies. Of these 510 patients, 412 underwent combined upper and lower gastrointestinal endoscopy and 98 underwent upper gastrointestinal endoscopy alone. Gastritis, gastric and duodenal ulcer disease were found significantly (each at least p less than 0.025) more often in patients with alcoholic liver disease than in those with nonalcoholic liver disease. The prevalence of the various lower gastrointestinal lesions in both groups was similar. Of particular interest is the fact that in alcoholic cirrhotics, the prevalence of gastritis, gastric ulcer and duodenal ulcer disease was unrelated to the degree of portal hypertension, whereas in the nonalcoholic cirrhotics the prevalence of gastritis and duodenal ulcer disease but not gastric ulcer disease was associated significantly with the degree of portal hypertension as assessed by the presence or absence of large esophageal varices, ascites, and hepatic encephalopathy.

Ascites↗