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Biomedical subjects

R Kumar

Publications and source records attributed to R Kumar.

At least 199 records · Page 11Linked to original sources
PubMed1996

Value of CT scan in the diagnosis of meningitis.

OBJECTIVE: To study the diagnostic test characteristics of computed tomography (CT scan) in differentiating tuberculous (TBM) and pyogenic (PM) meningitis. DESIGN: Prospective diagnostic test evaluation. SETTING: Teaching hospital. METHODS: Children beyond 1 month of age admitted with meningitis were enrolled prospectively and CT scan done. Results of CT scan were compared with predefined gold standards for the diagnosis of either TBM or PM. RESULTS: CT scan was performed in 154 patients with meningitis. Of these 94 were TBM, 52 had PM and 8 were indeterminate and excluded from analysis. Basal enhancement, ventriculomegaly, tuberculoma and infarction were all significantly more common in the TBM group, while subdural collections were seen more in the PM group. The highest sensitivity (89.2%) and specificity (100%) for diagnosis of TBM were found for basal enhancement or tuberculoma or both. CONCLUSIONS: CT scan can be used to effectively distinguish TBM and PM.

Cerebral Infarction↗
PubMed1996

Plasma vitamin A, zinc and selenium concentrations in children with acute and persistent diarrhoea.

Plasma zinc, selenium, and vitamin A concentrations in 25 children with persistent diarrhoea (PD) and acute diarrhoea (AD) were determined and compared with 25 age-matched control children. Plasma retinol concentrations (PRC) and plasma zinc concentrations (PZC) (3.92 micrograms/dL and 79.4 micrograms/dL respectively) were found to be significantly lower (p < 0.05) in children with PD. PZCs were also significantly reduced (p < 0.05) in children with AD. However, reduction in PZC was more in PD than that in AD. There was no significant difference in PSC in children with either types of diarrhoea as compared with the control group. The results of the study showed that there was deficiency of vitamin A and zinc in diarrhoeas which needs to be correlated for proper nutritional management.

Acute Disease↗
PubMed1996

Study of fungi associated with bronchopulmonary disorders.

Two hundred samples from sputum (160), bronchial secretions (35) and pleural aspirate (5) were analysed from patients of bronchopulmonary disorders. One hundred nine samples (54.5%) were positive for the fungi. Candida species (50%) were the predominant fungus isolated, followed by Aspergillus species (3.5%). Among various species of Candida, C. albicans accounted for 29.5% cases of bronchopulmonary disorders.

Aspergillosis↗
PubMed1996

Normal levels of the vitamin D receptor and its message in psoriatic skin.

Treatment with vitamin D3 analogs improves psoriasis. The vitamin D receptor (VDR) mediates most, if not all, the effects of vitamin D3. The purpose of this study was to determine the levels of the VDR mRNA and VDR protein in normal and in involved and uninvolved psoriatic skin. Although VDR mRNA was not detected by Northern analysis of human skin samples, it was readily detectable by use of the more sensitive ribonuclease protection assay. The VDR mRNA levels were normal in acute guttate as well as in chronic plaque lesions. There was also no difference in VDR mRNA levels between normal and uninvolved psoriatic skin. The VDR protein was detected by Western analysis using the monoclonal 9A7 gamma anti-VDR antibody and a polyclonal rabbit anti-VDR antibody. For comparison, VDR levels were analyzed in cultures of normal human keratinocytes and the epithelial cell line MCF-7. Studies of the extraction procedures for VDR showed that at least 60% of Escherichia coli-expressed VDR added to the skin biopsy specimens was recovered. The VDR concentration in normal human adult skin was approximately 50 pg/microgram protein, and the concentrations of VDR in involved and uninvolved psoriatic skin were of the same order of magnitude. Using the 9A7 gamma anti-VDR antibody, the VDR (M(r) 53,000) was constantly present in lower amounts than a band of M(r) 80,000 in both skin specimens and keratinocyte cultures. This high-molecular-weight band is most likely a cross-reacting protein not related to VDR, because it was absent when using the polyclonal anti-VDR antibody.

Adult↗
PubMed1995

Identification of metal-binding sites in rat brain calcium-binding protein.

Calbindin D28K binds 3 mol of terbium per mol of protein. To determine which of six EF-hand structures in the protein are responsible for terbium binding, we constructed three mutant forms of this protein, one lacking EF-hand 2 (RCaBP delta 2), the other lacking EF-hands 2 and 6 (RCaBP delta 2,6), and the third containing only EF-hands 3 and 4 (RCaBP delta 1,2,5,6), and examined their binding properties by fluorescence techniques. Full-length calbindin D28K and RCaBP delta 2 and RCaBP delta 2,6 bound 3 mol of terbium per mol of protein with high affinity. Thus, EF-hand domains 2 and 6 are not essential for calcium binding to the proteins, and an absence of EF-hands 2 and/or 6 does not alter the pattern of terbium binding to the protein. Using resonance energy transfer from tryptophan residues, one of the high affinity terbium-binding sites (site A) had a greater affinity than the other two sites (sites B and C) of each protein. Site A was filled before the other two sites. Calcium competition experiments showed that a greater amount of calcium was required to displace terbium from site A than from sites B or C. Energy transfer experiments from terbium to holmium showed that two of the terbium-binding sites are in close proximity while the third site is distant from the other two sites. To determine whether EF-hand 3 or 4 was responsible for binding of terbium, we examined the terbium binding properties of a delta 1,2,5,6 RCaBP construct. The truncated protein RCaBP delta 1,2,5,6 contained a single terbium-binding site. Analysis of the terbium binding to RCaBP delta 1,2,5,6 construct showed that site 4 bound terbium, whereas site 3 did not. Analysis of the terbium binding characteristics of the proteins suggests that EF-hands 1, 4, and 5 of rat brain calbindin D28K are responsible for terbium binding.

Amino Acid Sequence↗
PubMed1995

A case-control investigation on cancer of the ovary in Bangalore, India.

Cancer of the ovary is the sixth leading cancer among females in Bangalore, and is a leading site of cancer in other population-based cancer registries in India. A case-control investigation was conducted utilizing the data from the population-based cancer registry in Bangalore. In addition to the core patient information, certain other details pertaining to consumption of tobacco, reproductive and obstetric factors and those related to the practice of family planning, including the method adopted, were available with the registry, for the period 1982-1985. Identical information was also available for patients residing in the registry area who did not have cancer. Ninety-seven cases of ovarian cancer in ever-married women were age-matched with 194 controls from the same area who showed no evidence of cancer. The risk of ovarian cancer was not influenced by tobacco habits, alcohol consumption, diet or the various reproductive factors. However, tubectomy as a method of family planning appeared to reduce the risk of development of ovarian cancer. This reduction in risk was not influenced by parity or age of the woman at the time of birth of the first child.

Case-Control Studies↗
PubMed1995

The cytostatic activity of 5-(1-azidovinyl)-2'-deoxyuridine (AzVDU) against herpes simplex virus thymidine kinase gene-transfected FM3A cells is due to inhibition of thymidylate synthase and enhanced by UV light (lambda = 254 nm) exposure.

5-(1-Azidovinyl)-2'-deoxyuridine (AzVDU) and a series of 5-[1-azido-2-halogenoethyl]-derivatives of beta-D-arabinofuranosyluracil (AU) proved markedly inhibitory to the replication of herpes simplex virus type 1 (HSV-1) and varicella zoster virus (VZV), but not thymidine kinase (TK)-deficient HSV-1 and VZV strains. None of the compounds were cytostatic. However, AzVDU, but not the 5-[1-azido-2-halogenoethyl]-AU derivatives became highly cytostatic against HSV-1 and HSV-2 TK gene-transfected FM3A tumor cells. The molecular target for the cytostatic effect of AzVDU proved to be thymidylate synthase. Short exposure of AzVDU-treated FM3A TK-/HSV-1 TK+ cells to irradiation at lambda = 254 nm enhanced the cytostatic activity of AzVDU by 5-fold.

Animals↗
PubMed1995

P-selectin glycoprotein ligand-1 is the major counter-receptor for P-selectin on stimulated T cells and is widely distributed in non-functional form on many lymphocytic cells.

P-selectin glycoprotein ligand-1 (PSGL-1) is the high affinity counter-receptor for P-selectin on myeloid cells (Sako, D., Chang, X.J., Barone, K.M., Vachino, G., White, H.M., Shaw, G., Veldman, G.M., Bean, K.M., Ahern, T.J., Furie, B., Cumming, D. A., and Larsen, G. R. (1993) Cell 75, 1179-1186). Here we demonstrate that PSGL-1 is also widely distributed on T- and B-lymphocytic tumor cell lines, resting peripheral blood T and B cells, and on stimulated peripheral blood T cell and intestinal intraepithelial lymphocyte (IEL) lines. However, the majority of PSGL-1-positive resting peripheral blood lymphocytic cells and lymphoid tumor cell lines do not display significant P-selectin binding. In contrast, in vitro stimulated peripheral blood T cell and IEL lines avidly bind P-selectin, and PSGL-1 is the sole high affinity counter-receptor mediating this binding. During the course of in vitro stimulation, cell surface expression levels of PSGL-1 do not change as P-selectin binding increases. Rather, the activities of two glycosyltransferases reportedly involved in the production of functional PSGL-1 in myeloid cells are substantially higher in the stimulated T-lymphocytic lines than in resting T lymphocytes, consistent with the hypothesis that activation-dependent post-translational events contribute to the expression of functional PSGL-1 on lymphocytes.

Amino Acid Sequence↗
PubMed1995

Safety of intramuscular influenza immunization among patients receiving long-term warfarin anticoagulation therapy.

BACKGROUND: The effect of influenza vaccine on the prothrombin time (PT) among patients taking warfarin is unclear, as previous studies have shown conflicting results and the clinical significance of such a purported effect is uncertain. Moreover, to our knowledge, there are no data confirming the safety of intramuscular injections in patients receiving anticoagulant therapy with regard to possible local hematoma formation. We measured the effect of influenza vaccine on the PT among patients receiving long-term warfarin sodium therapy and evaluated the safety of intramuscular injections among them. METHODS: Forty-one adult patients who were receiving anticoagulant therapy were given 0.5 mL of influenza vaccine intramuscularly. Prothrombin time and arm girth were measured at baseline and on days 3, 7, and 14 after immunization. Local pain and tenderness were assessed on a five-point scale. Patients and study nurses were blinded to all prior measurements. Differences between baseline PT and that at each subsequent visit and the maximal change in arm circumference from baseline were calculated for each patient. Mean, range, and 95% confidence intervals were calculated for the entire group. RESULTS: There was no statistically significant change in PT between baseline and days 3, 7, and 14 after vaccination, and no significant change in arm circumference was noted. There were no clinically detectable local complications after intramuscular injection and no major or minor bleeding episodes after influenza vaccination. CONCLUSIONS: Influenza vaccine has no significant effect on the PT in patients who are being treated with warfarin. Influenza vaccine can be administered intramuscularly to patients who are receiving anticoagulant therapy without the risk of local bleeding complications.

Aged↗
PubMed1995

N-nitrosodimethylamine and 7-methylguanine DNA adducts in tissues of rats fed Chinese salted fish.

Previous studies have demonstrated that rats fed Chinese salted fish developed carcinomas of the nasopharynx and nasal cavity. In the present work the contents of nitrosamines in salted fish from the city of Guangzhou, southern China, and the contents of nitrosamines and possible nitrosamine-induced DNA adducts in organs of rats fed the fish were analysed. Similar levels of N-nitrosodimethylamine (NDMA) were detected in tough and soft salted fish. The NDMA content in steamed fish was higher than in raw fish. In vitro incubation of salted fish with gastric juice significantly increased the level of NDMA. NDMA was found in liver and kidney from rats fed salted fish for 2 years, but no dose-dependence was found between salted fish treatment and NDMA content. The level of 7-methylguanine in rat liver DNA was found to be slightly higher than in DNA from nasopharynx. However, there were no significant differences in the level of 7-methylguanine in DNA samples from rats fed salted fish and rats fed standard diet.

Animals↗
PubMed1995

Dual modulation of phosphorylation of a 60 kDa nuclear protein in interferon-alpha treated Daudi cells.

To explore the modulation of phosphorylation and/or kinase activity of cellular proteins in interferon-alpha (IFN-alpha) treated Daudi cells, experiments were performed to determine the effect of IFN-alpha on the ability of cellular proteins to undergo autophosphorylation reaction in-vitro. Treatment of cells with IFN-alpha significantly inhibited the amount of phosphorylation of a nuclear protein of about 60 kDa [+/- 3000 KDa, (P60)]. Results of phosphoamino acids analysis indicated that the nuclear P60 was a phosphotyrosine containing protein and was predominantly phosphorylated on threonine and serine in the absence of IFN-alpha. Treatment with IFN-alpha had a dual effect on relative phosphoamino acids content of P60: inhibited the phosphorylation on threonine residue, and enhanced the phosphorylation on serine and tyrosine residues. The nuclear P60 is not one of earlier described IFN-responsive signaling protein as it was not translocated from the cytosol.

B-Lymphocytes↗
PubMed1995

Significance of the secreted form of IpaC, a 45 kDa protein of Shigella dysenteriae 1, in the invasive process as determined by monoclonal antibodies.

Invasion plasmid antigen C (IpaC), a 45 kDa plasmid encoded protein, is associated with the virulence of virulent Shigella spp. In S. dysenteriae type 1 the 45 kDa IpaC protein is secreted to a greater extent into the surrounding medium in comparison to other Shigella spp. Monoclonal antibodies (mAbs) to the secreted form of IpaC protein were raised in this study. Of the four secretory hybrid cells, one (3G4) was found to have a very high antibody titre as determined by ELISA. The specificity of 3G4 was confirmed by immunoblotting of whole cell extract of Escherichia coli strain MC1061 carrying the plasmid pHW756 which synthesizes both the IpaB and C proteins. The effect of the mAbs on plaque formation by virulent Shigella dysenteriae 1 was determined and it was found that the clone 3G4 substantially (55%) reduced plaque formation on HeLa cell monolayer. The epitope specificity of the mAb 3G4 was competitively inhibited by the convalescent phase sera from human, suggesting that the epitope recognized by clone 3G4 was expressed during the natural course of infection and also indicating that the 45 kDa (IpaC) protein in secreted form has a definite role in the invasive process.

Animals↗
PubMed1995

Clinical survey of a psychiatric mother and baby unit: characteristics of 100 consecutive admissions.

Demographic, obstetric, clinical features and clinical outcome of 100 consecutive admissions to a psychiatric mother and baby unit are presented. Referral patterns by health services involved are also examined. 56% of admissions occurred within 2 weeks of delivery and the mean duration of admission was 2 months. Patients were categorized as having schizophrenia (n = 20), affective psychosis (n = 56) or non-psychotic disorders (n = 24) and these three groups were compared. There were few demographic and obstetric differences between diagnostic categories. The affective psychosis group were more likely to have acute illnesses with an onset and admission occurring within 2 weeks of delivery. Women with non-psychotic disorders were also most likely to become ill within 2 weeks of delivery but tended to be admitted later. Only 7% of the affective psychotic and non-psychotic women were discharged separated from their infants. Women with schizophrenia were less likely to have acute admissions and required greater input of nursing and service resources than mothers with other illnesses but 50% were discharged without their infants. More research is needed into matching models of care to the needs of mothers with different kinds of chronic, recurrent and new episodes of mental illness that present after childbirth. There are few guidelines to aid clinical staff in assessing the risk, current or future, of significant harm to an infant as a consequence of maternal mental illness, particularly of schizophrenia.

Adult↗