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Biomedical subjects

V K Sharma

Publications and source records attributed to V K Sharma.

At least 217 records · Page 12Linked to original sources
PubMed1994

Which way for drug-mediated immunosuppression?

The basic immunosuppressive protocol involves the use of multiple drugs, each directed at a discrete site in the T-cell activation cascade. The prevailing paradigm regarding the mechanisms of action of immunosuppressants is that they function to prevent allograft rejection by preventing cell activation, proliferation and/or cytokine production. A new hypothesis is that some of the immunosuppressants might function by stimulating the expression of immunosuppressive molecules and/or cells.

Animals↗
PubMed1994

Transcriptional regulation by TrsN of conjugative transfer genes on staphylococcal plasmid pGO1.

The major conjugative transfer gene cluster of staphylococcal plasmid pGO1 (trs) consists of 13 open reading frames (trsA to trsM) transcribed from one DNA strand and a single 189-bp open reading frame (trsN) within the first 348 bp of trs that is transcribed divergently. Promoter regions for trsN and trsA partially overlap. TrsN, a 7,181-Da protein, was purified as a fusion to glutathione S-transferase and found to have DNA-binding activity. Increasing concentrations of the fusion protein progressively retarded the gel migration of PCR-generated DNA fragments containing predicted promoters 5' to trsL, trsA, and trsN. The target sequences contained areas of identity, including regions of dyad symmetry, that were protected in DNase I footprinting studies. The binding of TrsN to its trsL target was required for this target DNA to be stably introduced into Staphylococcus aureus on a high-copy-number vector. Provision of excess TrsN from this high-copy-number vector in S. aureus decreased beta-galactosidase activity from a trsL-lacZ transcriptional fusion and decreased pGO1 conjugation frequency. Conversely, both transcription and conjugation increased in the presence of excess trsL target. We propose that TrsN negatively regulates the transcription of genes essential for conjugative transfer by binding to regions 5' to their translational start sites.

Amino Acid Sequence↗
PubMed1994

Isolation of an unknown compound, from both blood of Bhopal aerosol disaster victims and residue of tank E-610 of Union Carbide India Limited--chemical characterization of the structure.

A total of more than 28 chemical entities/reaction products in the form of gases, vapour and particulate matter were reported from the tank E-610 of methyl isocyanate (MIC) storage tank of Union Carbide India Limited on the night of 2/3 December 1984 in Bhopal. In earlier studies, methyl isocyanate and its trimer, with a few other compounds, were reported in the human victims preserved in deep freeze. Randomly selected samples were analysed by gas chromatograph coupled with mass spectrometer (ITD-800, Finnigan MAT, UK). Four of the cases showed the peaks and fragmentation pattern identified with one of the unidentified compound of molecular weight 269 amu in the Tank Residue, which constituted about 0.2 area per cent on GC-ITD. After isolation by column chromatography and being exposed to characterization, it was identified as a Spiro compound. It was possibly formed by the polymerization of five molecules of methyl isocyanate.

Accidents, Occupational↗
PubMed1994

Breast feeding pattern in neonates.

The present study comprised 100 mothers of newborn babies with regard to their belief and practices about lactation. A vast majority (98.2%) of the mothers were breast feeding, 87.9% mothers used prelacteal feeds of one sort or the other. Only 0.5% breast fed their babies within 6 hours and nearly 50% started after 48 hours. Colostrum was discarded by 82.9% of mother and nearly 73% wanted to continue breast feeding beyond 1 year. The age of weaning preferred was after 1 year by 91%. Only 24.7% mothers had undergone antenatal check ups. Hence, much needs to be done with regards to proper antenatal care and advice to discourage wrong and harmful feeding practices.

Attitude↗
PubMed1994

Mortality patterns in breast versus artificially fed term babies in early infancy: a longitudinal study.

In this study 500 full term breast fed and 500 full term top fed babies were divided into 2 groups of weight > 2.5 kg and < or = 2.5 kg each, and were followed up for the mortality pattern. Eight hundred of these completed the full follow up period of 6 months. Neonatal mortality in term babies in the present study was 40 per thousand and mortality during 1-6 months period was 55 per thousand. Early neonatal mortality in breast fed > 2.5 kg was 0.55% against 7.8% in < or = 2.5 kg breast fed babies. The corresponding figures in artificially fed was 1.17% and 9.37% respectively. Late neonatal mortality in breast fed > 2.5 kg was 0 and in < or = 2.5 kg was 2.14%. These values in artificially fed were 0 and 3.12%, respectively. Mortality in 1-6 months period in breastfed > 2.5 kg was 0.64% and in < or = 2.5 kg was 15.5%; and in artificially fed 1.66% and 23% respectively. Thus LBW babies whether breast fed or artificially fed had higher mortality and artificially fed had overall higher mortality in comparison to breast fed. It is concluded that attention should be directed towards promotion of breast feeding and on prevention of low birth weight for decreasing mortality in early infancy.

Bottle Feeding↗
PubMed1994

Human giardiasis. A morphometric study of duodenal biopsy specimens in relation to the trophozoite count in the duodenal aspirate.

We present a morphometric analysis of findings from a histopathologic study of duodenal giardiasis in relation to the trophozoite count in the duodenal aspirate. Of 30 patients with giardiasis whose conditions were studied, a mean trophozoite count of 10(3)/mL or greater was found in 21, and a mean trophozoite count of less than 10(3)/mL was found in nine--these two types of trophozoite counts in these 30 patients represented the acute phase (group 1) and the clearance phase (group 2) of giardiasis, respectively. Group 1 patients had a low mean villus height that was significantly less than that found in the control subjects. Group 2 patients had a high mean crypt depth that was significantly greater than that found in the control subjects. Partial villus atrophy was seen in only seven of the group 1 patients, including five with villus epithelial cell lesions. Groups 1 and 2 showed minor differences of an inflammatory response that was significantly greater than that shown in the control subjects.

Adult↗
PubMed1993

Synergism between the CD3 antigen- and CD2 antigen-derived signals. Exploration at the level of induction of DNA-binding proteins and characterization of the inhibitory activity of cyclosporine.

We have demonstrated earlier that the crosslinkage of the CD3/TCR complex with the CD2 antigen results in the proliferation of normal human T cells. The effect of this synergism was perceptible at the level of induction of the IL-2 gene, a process critical for T cell growth. To further understand the molecular and nuclear basis for this synergism, we have explored the induction of DNA-binding proteins in highly purified normal human T cells signaled via the CD3 and/or CD2 proteins. The effect of transmembrane signaling of T cells with ionomycin, and/or sn-1,2 dioctanoyl glycerol, was also determined. The emergence of nuclear binding proteins was investigated using interleukin-2 sequence specific oligonucleotide probes in the electrophoretic mobility shift assay. Our studies demonstrate for the first time that CD3 antigen-derived signals and CD2 antigen-derived signals are synergistic in inducing the emergence of transcription factors that bind to the NF-AT1, AP-1, and NF-kB sites located in the promoter/enhancer region of the IL-2 gene. Moreover, cyclosporine, at concentrations readily accomplished in clinical practice, was found to inhibit the emergence of these DNA-binding proteins in normal human T cells signaled via cell surface proteins implicated in antigen-dependent T cell activation and in T cells stimulated by mobilization of cellular calcium and activation of protein kinase C.

Antigens, Differentiation, T-Lymphocyte↗
PubMed1993

Tongue involvement in lepromatous leprosy.

BACKGROUND: Involvement of the oral cavity in lepromatous leprosy is well-documented. The tongue may demonstrate multiple nodules, thickening, and scarring. METHODS: Ten consecutive untreated patients with lepromatous leprosy with a bacteriologic index of 4+ or more were clinically and histopathologically studied for evidence of tongue involvement. RESULTS: Three patients showed clinical tongue involvement, as a nodulo-plaque lesion in one patient and fissured tongue (lingua plicata) in two patients. Tongue was clinically normal or showed nonspecific changes in the remaining seven patients. Histologic evidence of tongue involvement by lepromatous process was seen in six patients, including three without clinical involvement. CONCLUSIONS: We conclude from this study that the tongue is as prone to involvement by lepromatous process as buccal and palatal mucosa.

Adult↗
PubMed1993

Exchange transfusion in neutropenic septicemic neonates: effect on granulocyte functions.

Depletion neutropenia caused by overwhelming bacterial infection is associated with fatal outcome and is an objective indicator of the severity of sepsis. Studies on controlled evaluation of exchange transfusion in the management of severe neonatal sepsis have not considered neutropenia as an inclusion criterion, and randomized, controlled trials on evaluation of neutrophil functions after exchange transfusion are scarce. This prompted us to carry out the present study. Septicemic neonates were enrolled if they had neutropenia and were randomized to undergo exchange transfusion (study group, n = 20) or not (controls, n = 10). Granulocyte functions were assessed using the nitro blue tetrazolium (NBT) reduction test and the staphylococcidal index. Blood was drawn for granulocyte function tests once from controls and donors, and before, immediately after and 6 h after exchange transfusion in the study group. Mortality was 35% in the study group and 70% in controls. Gram-negative organisms accounted for 80% in the study group and 90% in controls. Mean total leukocyte count and neutrophil count increased significantly immediately after exchange transfusion and 6 h later. Absolute band count decreased significantly immediately after exchange transfusion and increased 6 h later. NBT reduction in septicemic neonates in the study group, as well as in controls, was significantly decreased as compared to donor cells. NBT reduction improved significantly immediately after exchange transfusion and 6 h later. The values of the percentage of viable staphylococci recovered from neutrophils also improved significantly immediately after exchange transfusion and 6 h later.(ABSTRACT TRUNCATED AT 250 WORDS)

Bacteremia↗
PubMed1993

Concurrent skin and nerve histology in leprosy and its role in the classification of leprosy.

Concurrent skin and nerve histology was evaluated in 60 leprosy patients (25 BT, 28 BL and 7 LL). The twin aims were to study the comparative histology and the usefulness of nerve histology in the classification of the disease. In BT patients, clinical and histological classification was in agreement in 11 (44%) skin and 17 (68%) nerve biopsies. Concurrent skin and nerve histology was in consonance in 14 (56%) BT patients, while in 6 (24%) patients, only nerve histology was helpful in the classification of the disease, the skin histology being non-specific. Nerve histology was classified as BL in 3 (12%) BT patients, the skin histology was non-specific. In the BL group, the histology of 23 (82.4%) nerve biopsies correlated with the clinical classification, in contrast to skin histology which correlated with clinical assessment in 19 (68%) patients only. In the LL patients, the histology of nerve correlated with the clinical classification in 5 patients (71.4%), compared to histology of the skin in 4 (57%) patients only. The GF was higher in the nerves than in the skin throughout the leprosy spectrum (BT, BL, LL); the difference was, however, marginal in BL leprosy. The average bacteriological index (BI) was higher in nerves (4+) compared to that of skin histology and slit skin smears (3+) in BL leprosy. There was, however, no difference in the BI of the slit skin smears, skin and nerve biopsies in lepromatous leprosy.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

Transport of amino-acids across renal brush border membrane vesicles in Mycobacterium leprae infected Swiss albino mice--effect of Convit vaccine.

Brush border membrane vesicles prepared from kidneys of Mycobacterium leprae infected (non-vaccinated) and vaccinated-infected Swiss albino mice were used to assess the effect of Convit's combined vaccine (BCG + M. leprae) on amino acid transport activity across the tubular basement membrane. The protective effect of Convit's vaccine was more pronounced with respect to the uptake of L-alanine than L-aspartate. Uptake of L-lysine showed no significant difference in the different groups. Footpad counts followed characteristic growth curves in the non-vaccinated infected group but showed a lag in the development of peak levels in the vaccinated group. Further Convit's vaccine appeared to have a protective effect on renal impairment in the mouse model of leprosy in the initial stages of infection only, as indicated by the transient reversal of amino acid uptake and a diminution in the footpad counts induced by M. leprae infection. No significant (P > 0.05) protective effect of the vaccine was found in the advanced disease state.

Amino Acids↗