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Biomedical subjects

R Kumar

Publications and source records attributed to R Kumar.

At least 739 records · Page 41Linked to original sources
PubMed1996

Civilian vascular trauma: an experience of 54 cases.

Fifty-four patients with civilian vascular injuries of the extremities caused by blunt trauma in 41 patients and by penetrating trauma in 13 patients were evaluated. Twenty-nine patients (53.7%) had associated fractures/dislocations and 19 sustained concomitant venous injuries. Twenty-nine patients (53.7%) came with a lagging period of more than 12 hours. Vascular injuries were diagnosed both clinically and by Doppler examination. In patients with equivocal findings, arteriography was performed. Arterial repair was done in 19 patients and saphenous vein interposition grafting was done in 2 patients. Fifteen patients required fasciotomy. Amputation was done in 13 patients (24.07%). It is concluded that the time lag, incorrect and incomplete assessment, and the reluctance to perform fasciotomy early and completely are some of the factors responsible for poor results.

Adolescent↗
PubMed1996

Bcl-2 expression regulates sodium butyrate-induced apoptosis in human MCF-7 breast cancer cells.

Sodium butyrate (butyrate) is a potent growth inhibitor and differentiating agent for many cell types, including breast cancer cells. Programmed cell death, or apoptosis, is a physiological mechanism of cell death that is dependent on both preexisting proteins and de novo protein synthesis. In the studies presented here, we investigated the role of apoptosis in the growth regulation of human MCF-7 breast cancer cells by sodium butyrate. We report that butyrate treatment of breast cancer MCF-7 cells causes a nonreversible growth inhibition by inducing apoptosis in a time- and dose-dependent manner. Treatment of MCF-7 cells for as little as 12 h with butyrate caused a 5.6-fold induction in apoptotic cell death, which continued to increase up to 27-fold by 48 h treatment. The butyrate-induced apoptosis in MCF-7 cells was closely linked with the down-regulation of expression of Bcl-2 mRNA and Bcl-2 protein, a gene product known to be involved in the regulation of apoptosis in mammalian cells. The observed relationship between the down-regulation of Bcl-2 and induction of apoptosis was not causal because stable overexpression of Bcl-2 resulted in protection of MCF-7 cells from the cytotoxic morphological changes and growth-inhibitory effects of butyrate (15% growth inhibition compared to 60% growth inhibition in the parental cells). In addition, Bcl-2-overexpressing MCF-7 cells exhibited a significant suppression in butyrate-induced stimulation of apoptosis (5-fold increase in apoptosis compared to 27-fold in parental MCF-7 cells). These findings demonstrate that the levels of Bcl-2 expression regulate the butyrate-induced apoptosis in breast cancer cells and that butyrate may potentially be useful in sensitizing the breast cancer cells to chemotherapy-induced apoptosis.

Apoptosis↗
PubMed1996

Primary tuberculosis of esophagus.

Primary tuberculosis of the esophagus is rare. We report a young lady with odynophagia who had esophageal tuberculosis without evidence of the disease elsewhere in the body.

Adult↗
PubMed1996

Carcinoma penis in a young boy. A case report.

Carcinoma of the penis below the age of fifteen years is a rarity. A 14 year old boy presenting with advanced carcinoma penis with bilateral fungating inguinal lymphadenopathy is the subject of this case report.

Adolescent↗
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↗
PubMed1996

Overexpression of HER2 modulates bcl-2, bcl-XL, and tamoxifen-induced apoptosis in human MCF-7 breast cancer cells.

Overexpression of HER2 in estrogen receptor (ER)-positive human breast tumors has been associated with resistance to endocrine therapy. Here we investigated the effects of HER2 on expression of apoptotic pathways and modulation of tamoxifen-induced apoptosis in ER-positive MCF-7 breast cancer cells. We report that HER2 overexpression in MCF-7 cells is accompanied by up-regulation of antiapoptotic Bcl-2 and Bcl-XL proteins and suppression of tamoxifen-induced apoptosis. In addition, human tumor cell lines that are both ER positive and overexpress HER2 also express enhanced levels of Bcl-2 compared to cells that are either ER positive or overexpress HER2 alone. Our findings suggest that possible deregulation of antiapoptotic Bcl-2 and Bcl-XL may be associated with the enhanced survival of HER2-overexpressing and ER-positive breast cancer cells treated with antiestrogens.

Apoptosis↗
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

Purification, crystallization and preliminary X-ray crystallographic analysis of lactoperoxidase from buffalo milk.

The lactoperoxidase was prepared from buffalo milk and purified using CM-Sephadex C-50 and Sephadex G-100. The activity of the enzyme was measured using 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) diammonium salt as a chromogenic substrate at pH 6.0. The purified protein was crystallized from 0.01 M sodium phosphate buffer (pH 8.0) with 10%(v/v) ethanol by the sitting-drop vapour-diffusion method. The green-coloured plate-like crystals are orthorhombic in space group P2(1)2(1)2(1) with unit-cell dimensions a = 116.9, b = 103.2 and c = 62.3 A. The asymmetric unit contains one molecule with a solvent content of 52%. The crystals were stable in the X-ray beam and diffract beyond 3.2 A. The native data to 3.5 A have been collected and the structure determination is in progress.

Journal Article↗