Search PubMed⌕ Search

Biomedical subjects

G Singh

Publications and source records attributed to G Singh.

At least 307 records · Page 17Linked to original sources
PubMed1996

Bacteriology of necrotizing infections of soft tissues.

BACKGROUND: Necrotizing infections of soft tissues (NIST) are being attributed to a large variety of organisms, besides the originally described beta-haemolytic Streptococcus. A detailed bacteriological study of these infections was thought worthwhile. METHODS: A prospective study of 55 patients with NIST was carried out. Analysis of surface swabs and debrided tissue for aerobic and anaerobic bacteria and fungal infection was performed. A detailed bacteriological profile was obtained in 50 patients. RESULTS: A total of 257 isolates (167 aerobic, 90 anaerobic) was obtained. One to nine strains of bacteria were isolated from each patient. Aerobic bacteria alone were isolated in 26 patients while the remaining patients grew both aerobic and anaerobic bacteria. Forty-two patients had at least one Gram-positive bacterium while 40 had at least one Gram-negative bacterium. Staphylococcus aureus was the organism isolated most frequently (52%), followed by Bacteroides fragilis (40%) and anaerobic cocci (38%). Group A beta-haemolytic streptococci were isolated in 16%. Blood cultures were positive in only eight patients. Fungal cultures were positive in six patients. Aspergillus fumigatus was the commonest pathogen. CONCLUSIONS: Necrotizing infections of soft tissues are polymicrobial and no single bacterium is associated with a specific clinical entity. Importance should be placed on early recognition and treatment of the disease rather than on isolation of bacteria.

Adolescent↗
PubMed1996

Tachyphylaxis to histamine-induced wheal suppression by topical 0.05% clobetasol propionate in normal versus croton oil-induced dermatitic skin.

BACKGROUND: Patients often tell about reduced effectiveness of topical steroids on repeated use. Tachyphylaxis to these agents has been demonstrated in humans for vasoconstriction and histamine-induced wheal suppression in normal skin, but not in diseased skin. Relevance of these data to diseased skin is not clear. Further, the clinical impression does not appear to match tachyphylaxis shown in normal skin with regard to the time course. OBJECTIVES: To examine whether tachyphylaxis to histamine-induced wheal suppression by a topical steroid occurs in dermatitic skin and to determine its time course vis-à-vis normal skin. METHODS: Pharmacodynamic response to 0.05% clobetasol propionate applied daily under occlusion was measured by histamine-induced wheal suppression assay in 10 individuals. This test was performed on a steroid-treated normal site, on a steroid-treated site where dermatitis was induced by occlusive application of 40% croton oil, and on a vehicle-treated site in each individual at different intervals up to 14 days. RESULTS: Suppression of wheal volume started from second day in steroid-treated sites. There was significant difference in the wheal volume in steroid treated normal vs. dermatitic sites from day 2 to day 10. Maximum wheal suppression occurred earlier in dermatitic skin (day 4 vs. day 6). After this, the volume of wheal started increasing and became equal to control (complete tolerance) on 12th day in dermatitic skin and on 14th day in normal skin. CONCLUSIONS: Time courses of tachyphylaxis to the action of 0.05% clobetasol propionate were significantly different in normal skin and dermatitic skin. Complete tolerance occurred earlier in dermatitic skin compared to normal skin.

Administration, Topical↗
PubMed1996

Interstitial cystitis: involvement of the intestine.

Two patients with intractable interstitial cystitis are presented. Both have had substitution enterocystoplasty and in both, unabated symptoms have resulted in ileal loop diversion. In both patients the excised neobladder had shown extensive changes of interstitial cystitis involving all layers, including the muscle layers of the explanted intestine. Also in one of these patients, symptoms suggestive of interstitial cystitis persisted and biopsies taken from the ileal loop have shown histological changes characteristic of interstitial cystitis. The presentation of interstitial cystitis in the intestine is discussed and we conclude that interstitial cystitis does manifest in the intestine.

Cystitis, Interstitial↗
PubMed1996

Keratinocyte growth factor and embryonic rat lung morphogenesis.

We examined possible roles of keratinocyte growth factor (KGF) and hepatocyte growth factor (HGF) in lung morphogenesis. By polymerase chain reaction, transcripts for both KGF and its receptor were detected early (rat gestational days 16 and 14, respectively) and their abundance increased during lung morphogenesis. To evaluate possible role of KGF in lung morphogenesis, day 14 lung explants were cultured in Dulbecco's modified Eagle medium + 10% fetal calf serum for 1 to 4 days in the presence (5-50 ng/ml) or absence of KGF (control). KGF (at 25 and 50 ng/ml) induced a marked reduction in the number of terminal branches and destination of the distal epithelium into cyst-like structures. These effects of exogenous KGF were progressively diminished by increasing concentrations of anti-KGF (2-16 micrograms/ml). Electron microscopic examination revealed that the epithelial cells of the cystic structures contained lamellar bodies, and were therefore type II cells and/or their progenitors. Northern blot analysis showed higher expression of surfactant protein C (SP-C) mRNA (a marker for alveolar epithelial type II cells) in KGF-treated fetal lungs. In situ hybridization of the KGF-treated lungs revealed that the SP-C mRNA-expressing cells were arranged distally in the form of linear arrays, a pattern distinctly different from that in control lungs. Acidic fibroblast growth factor, which also binds KGF receptors, in the presence of heparin mimicked the effect of KGF on branching. Transforming growth factor-beta(1) (TGF-beta 1) inhibited branching of fetal lungs in culture, and this effect dominated over that induced by KGF. Blocking of endogenous HGF with antibodies or addition of HGF to cultures of fetal lung explants had no significant effect on branching or growth. In conclusion, KGF markedly influences branching, and epithelial growth, differentiation, and patterning during lung morphogenesis.

Animals↗
PubMed1996

Ontogeny of Clara cell-specific protein and its mRNA: their association with neuroepithelial bodies in human fetal lung and in bronchopulmonary dysplasia.

Clara cell-specific 10-KD protein (CCSP) is an abundant product of nonciliated bronchiolar epithelial (Clara) cells in the lung. We have determined the temporal-spatial distribution of CCSP and its mRNA in developing human lung and in neonatal lung disease, using immunohistochemistry and in situ hybridization. CCSP immunoreactivity was found in nonciliated bronchiolar epithelial cells from 12 weeks of gestation onward. Tracheal and bronchial epithelia showed positive immunoreactivity at each gestational week after 15 weeks and 14 weeks, respectively. CCSP mRNA was seen in the bronchial and bronchiolar epithelia from 16 weeks onward and was detected in the trachea from 19 through 23 weeks of gestation. CCSP immunoreactivity and mRNA were present in nonciliated single cells of bronchial and bronchiolar epithelia in fetuses and in infants with and without lung disease. CCSP- and CCSP mRNA-containing epithelial cells also formed dusters around neuroepithelial bodies (NEBs), especially at airway branch points, suggesting that NEBs and Clara cells might interact during development and during pulmonary regeneration. Because of evidence of overlapping of some but not all cells expressing CCSP, SP-A, and pro-SP-B during lung development, a common cell lineage is proposed, with subsequent divergence of phenotypes.

Bronchopulmonary Dysplasia↗
PubMed1996

Embryonic mouse lung epithelial progenitor cells co-express immunohistochemical markers of diverse mature cell lineages.

Developmental expression of marker genes representative of different mature cell types can be used to study differentiation of cell lineages. We used immunohistochemistry to study expression in developing mouse lung of calcitonin gene-related peptide (CGRP), Clara cell 10-KD protein (CC10), and surfactant protein-A (SP-A), markers that are differentially expressed in neuroendocrine cells, Clara cells, and Type II alveolar cells. Two distinct developmental phases were revealed. The earlier phase (embryonic days 13-15; E13-E15) was characterized by CGRP, CC10, and SP-A immunostaining in all epithelial cells of the distal airways, with the three patterns being virtually identical in adjacent sections. The later phase (E16-E18) was characterized by emergence of staining of the differentiated cell types. These expression patterns were recapitulated in serumless organ culture, demonstrating that information necessary to generate both phases of gene expression is present within the lung analage by E11. We conclude that CGRP, CC10, and SP-A are co-expressed in most or all cells of the distal lung epithelium at E13-E15 and later become restricted to different cell lineages. This transient expression in progenitor cells of gene products characteristic of diverse differentiated cell types may reflect an underlying mechanism of gene regulation.

Animals↗
PubMed1996

Preparation and characterization of human recombinant protein 1/Clara cell M(r) 10,000 protein.

Protein 1, which is identical to human Clara cell M(r) 10(4) protein, is a homodimeric, low molecular mass protein (M(r) 14,000) and an effective inhibitor of phospholipase A2 activity. We have expressed this protein in E. coli and characterized its physiochemical and biological properties. Using a pET expression system, about 1.7 mg of purified recombinant protein 1 was obtained from 250 ml of E. coli culture. The amino-terminal sequence of recombinant protein 1 up to the 20th residue was identical to that of native protein 1 except for an extra methionine at the amino-terminus. On reversed-phase HPLC, recombinant protein 1 eluted at the same retention time as native protein 1. The dose-response curves of recombinant protein 1 and native protein 1 in an enzyme-linked immunosorbent assay for protein 1 were identical. Recombinant protein 1 inhibited both porcine pancreas and cobra venom phospholipase A2 activities. These results indicated that recombinant protein 1 is structurally and biologically identical to native protein 1. We found that recombinant protein 1 also inhibits phosphatidylinositol-specific phospholipase C activity.

Chromatography, High Pressure Liquid↗
PubMed1996

Effect of zinc on the epithelial lining of mice epididymis--a light microscopic study.

Intraperitoneal zinc chloride was administered at 7.5 micrograms/g body weight and 15 micrograms/g body weight to 10-12 weeks old Swiss albino mice for 5 consecutive days. Control animals were given normal saline. The testis and epididymis were dissected and examined under the light microscope. Micrographs of the testes appeared normal in both treated and nontreated animals. However the group of animals treated with the higher dosage of zinc chloride showed evidence of rupture and collapse of the epididymal epithelial lining. The testes were not affected probably because of (a) known higher testicular concentration of metallothioneins which can bind the zinc and consequently detoxify the metal and (b) "stratified" epithelium comprising of spermatogenic and Sertoli cells.

Animals↗
PubMed1996

The role of anti-malarials in rheumatoid arthritis--the American experience.

Rheumatoid Arthritis (RA) is a chronic disease with significant morbidity and functional disability. The traditional treatment for RA relied on the use of NSAIDs early in the disease course, followed by disease-modifying agents later. More recently, the disease-modifying anti-rheumatic drugs (DMARDs) have become the mainstay of RA therapy because of the recognition of their superior efficacy/toxicity profile. The antimalarial drugs, chloroquine and hydroxychloroquine, are some of the most commonly used DMARDs in the management of RA. They have been shown to be significantly more effective than NSAIDs alone in several clinical trials, and have a benign toxicity profile. A combination of hydroxychloroquine with methotrexate appears to reduce significantly the hepatic toxicity of methotrexate. In this review, we summarize the efficacy and toxicity profiles of the antimalarial drugs in rheumatoid arthritis.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1996

Role of botulinum toxin in treatment of achalasia cardia.

Pneumatic dilatation and surgery are equally effective in the treatment of achalasia cardia but carry some risk of complications. We report our initial experience with the use of botulinum toxin in the treatment of achalasia. Six of seven patients treated responded, with improvement lasting till the end of follow-up at 3 months. No adverse effect was observed.

Adult↗
PubMed1996

Improved method for study of chromosomes of chorionic villus samples.

Chorionic villus sampling (CVS) offers rapid prenatal diagnosis of chromosomal disorders. We evaluated four methods for chromosomal analysis of chorionic villi (three based on direct preparations and one on long-term culture) in order to define a method which would provide good quality metaphases in sufficient numbers. The direct culturing method using synchronisation and dissociation with dispase was as good as long-term culturing. The optimal period of gestation for study was 10-12 wk.

Chorionic Villi Sampling↗
PubMed1996

Trichinosis--a case report.

A case of human trichinosis is reported. This is the first case of human trichinosis being reported in India.

Adult↗
PubMed1996

Cytogenetic studies in ataxia telangiectasia & their use in prenatal diagnosis.

Cytogenetic studies were carried out in obligate ataxia telangiectasia (AT) heterozygotes, AT homozygotes and control subjects. Rate of chromosomal aberrations and the frequency of micronuclei were examined before and after radiation (100 rads). Significant differences in the rate of chromosomal aberrations and micronuclei were observed among heterozygotes, homozygotes and controls. The same methods were then applied for prenatal diagnosis of AT using amniotic cell culture in two families.

Ataxia Telangiectasia↗
PubMed1996

Endodermal sinus tumour of cervix--case report.

Endodermal sinus tumor of Cervix is an extremely rare cause of vaginal bleeding. Because of its rarity and interesting features, it is reported with a brief review of literature.

Combined Modality Therapy↗