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Biomedical subjects

S Mishra

Publications and source records attributed to S Mishra.

At least 127 records · Page 7Linked to original sources
PubMed1993

Exogenous phosphotyrosine modulates epidermal growth factor receptor tyrosine phosphorylation.

Protein tyrosine phosphatases (PTPases) are potential tumor suppressor proteins which reverse the effects of protein tyrosine kinases (PTKs). We hypothesized that the induction of PTPase activity by the nutritional agent O-phospho-L-tyrosine (P-Tyr), a broad PTPase substrate, could potentially enhance total cellular PTPase activity and inhibit cell growth. In this study, we report that P-Tyr inhibited the growth of MDA-MB 468 cells in a dose-dependent fashion. P-Tyr incubation increased total cellular PTPase activity in MDA-MB 468 breast carcinoma cells. The increase of PTPase activity, as measured by a standard radioactive assay for PTPases, occurred within 10 min of P-Tyr incubation and was dependent on the concentration and time of incubation with P-Tyr. The increased PTPase activity in P-Tyr treated cells was also evident from a non-isotopic PTPase assay involving the dephosphorylation of epidermal growth factor receptor (EGFR). Epidermal growth factor (EGF)-mediated tyrosine phosphorylation of EGFR was decreased in situ in a time- and dose-dependent manner in P-Tyr-treated cells. Orthovanadate (100 microM for 4 h) inhibited this decrease, implicating the role of cellular PTPase in P-Tyr-mediated control of EGFR tyrosine phosphorylation. Further, EGFR kinase activity was found to be decreased in P-Tyr-treated cells. We conclude that P-Tyr may inhibit cell growth by decreasing cellular tyrosine phosphorylation. Both a decrease in activity of the EGFR kinase and increases in PTPase activity may have accounted for the growth inhibiting property of P-Tyr.

Breast Neoplasms↗
PubMed1993

A microsatellite-based index map of human chromosome 11.

We have constructed a continuous index map of 25 microsatellite markers on human chromosome 11. The markers have been typed in 40 CEPH families, have heterozygosities of 69% or higher and can be typed by PCR. The odds against inversion of adjacent marker loci order are at least 10(5):1. The sex average map covers a total of 162 cM with no gap exceeding 15 cM. Total lengths for female and male maps are 205 and 123 cM, respectively. By use of a hybrid cell panel or by in situ hybridization, 16 of the markers have also been mapped cytogenetically, providing a good correlation of the index map with the cytogenetic map. The map will facilitate high resolution mapping of additional polymorphic loci and of disease genes on chromosome 11.

Chromosome Mapping↗
PubMed1993

ARI control programme: results in hospitalized children.

One hundred cases of pneumonia with chest indrawing were treated according to the treatment protocol of the ARI control programme. The majority of children were > 2 months old (85 per cent) with male predominance (61 per cent). All cases with severe pneumonia survived. A mortality rate of 7.7 per cent was seen in cases of very severe pneumonia. Three children in the severe pneumonia group deteriorated on benzyl penicillin to very severe pneumonia but subsequently improved on chloramphenicol. Six patients were treated as cases of Staphylococcal pneumonia and one of them died. Thirteen children (21.3 per cent) in the severe pneumonia group required oxygen for breathing rates > 70 per minute. Seventy-four per cent in the very severe pneumonia group required administration of IV fluids. Blood counts did not prove to be of help in differentiating the children at risk of dying. There was no significant difference in roentgenographic findings in the two groups. Congestive cardiac failure was the most common complication, seen in 33.3 per cent of cases of the very severe pneumonia group. The duration of stay was significantly less in cases of severe pneumonia (4.21 +/- 1.59 days) as compared to very severe pneumonia (9.35 +/- 2.39 days). The data from this study suggest that the treatment protocol for the ARI control programme for hospitalized children is reasonably effective and can be implemented in small hospitals.

Acute Disease↗
PubMed1993

High dose-rate endobronchial irradiation in malignant airway obstruction.

We evaluated the effectiveness of high dose rate (HDR) endobronchial irradiation for palliation of malignant airway obstruction. Between May 1989 and February 1992, 39 patients were treated in our department. Thirty-two patients (82 percent) had primary lung neoplasms and 7 (18 percent) had metastatic disease. Thirty-three patients (85 percent) had prior external irradiation (either alone or in combination with chemotherapy), and 9 patients (23 percent) received laser excision before treatment. Of the 39 patients, 14 (36 percent) presented with hemoptysis, 20 (51 percent) with cough, 15 (38.5 percent) had dyspnea, and 15 patients (38.5 percent) had pneumonia or atelectasis. There were 57 applications performed in the 39 patients. Patients with hemoptysis had 93 percent complete response (CR), 20 percent with cough had CR; 60 percent improved (partial response [PR]); no response was seen in 20 percent. Atelectasis and pneumonia resolved in 20 percent of patients. Eighteen patients (46 percent) underwent a second procedure and were evaluated for objective response; 34 percent had CR, 44 percent had PR, and 22 percent did not respond. There were two acute (one bronchospasm, one pneumothorax) and three late (two strictures, and one exsanguination) complications. In our experience, HDR was highly effective in the palliation of airway symptoms caused by malignant tumors, with acceptable toxicity.

Adult↗
PubMed1993

Need of dietary energy at critical implantation time when local ovarian hormones are obligatory for conceptus development.

Role of dietary energy and local ovarian hormones in conceptus development in the rat was evaluated by giving ip injections of estrogen and progesterone under diet restricted and/or dextrose supplemented conditions, using the experimental model of ovarian compensatory hypertrophy. Replacement of estrogen on day 2 and progesterone on day 3 was necessary for conceptus development in the ipsilateral uterine horn after unilateral ovariectomy on day 2. Continuation of progesterone injection up to day 9 improved the percentage of conceptus development. Conceptus development was normal when unilateral ovariectomy was performed after day 2 of pregnancy. Compensatory increases in corpus luteum (CL) volume and the activity of delta 5 3 beta-hydroxy steroid dehydrogenase (3 beta-HSD) in contralateral ovary were observed after unilateral ovariectomy on day 2-4 of pregnancy. However, 70% diet restriction reducing the energy intake (from 90 to 27 kcal/rat/day) abolished the single dose hormone therapy effects in ipsilateral horn conceptus development and also reduced the effects of continued progesterone, percentage of contralateral horn conceptus development, compensatory changes in the CL volume and delta 5 3 beta-HSD activity of the contralateral ovary. However, dietary dextrose supplementation (increasing calorie intake from 27 to 56 kcal/rat/day) significantly improved/restored hormone response for conceptus development, compensatory changes of the CL volume and enzyme activity in contralateral ovary. The results suggest that day 2-3 of pregnancy is the critical time when local ovarian supply of estrogen and progesterone are obligatory for establishment and conceptus development in the rat. During this period adequate mobilizable source of energy is necessary for execution of hormonal message.

3-Hydroxysteroid Dehydrogenases↗
PubMed1992

Galactocerebroside mediates Ca2+ signaling in cultured glioma cells.

Expression of galactocerebroside (GalC) was detected in human glioma cell line (U-87 MG). Exposure of cells to antibody against GalC and fluoresceinated second antibody showed intense fluorescence on the plasma membrane. Possible involvement of GalC in receptor-mediated transmembrane signaling was explored in this cell line. Antibodies raised against GalC were used as ligands. Binding of anti-GalC to these cells caused a transient increase in intracellular free calcium ([Ca2+]i). The response was observed both in the presence and absence of extracellular calcium demonstrating that the rise in [Ca2+]i induced by anti-GalC was due to an influx of Ca2+ through plasma membrane as well as the release of Ca2+ from intracellular pools. Ca2+ influx was blocked by verapamil, indicating that influx is mediated by voltage-sensitive channels. Our results suggest that GalC can play a role in transmembrane signaling by modulation of voltage-sensitive Ca2+ channels.

Calcium↗
PubMed1992

Primary reconstruction of major human bite wounds of the face.

Primary reconstruction of 36 major human bite wounds of the face without clinical infection has been carried out successfully as late as the fourth day after the initial injury. Primary healing was achieved in all patients. The postoperative period was free from major infection in all patients except one, including the latecomers. Extensive bacteriologic studies reveal that the infection in human bite wounds occurs secondarily as invasion to devitalized tissue. We therefore consider that debridement of wound edges to eliminate the crushed devitalized tissue is the key to success.

Adolescent↗
PubMed1992

Clinical presentation as a guide to early prognosis in vertebrobasilar stroke.

BACKGROUND AND PURPOSE: This study attempts to assess the feasibility and heuristic value of a classification scheme for vertebrobasilar stroke. METHOD: Fifty-seven consecutive patients with vertebrobasilar stroke were classified on the basis of clinical features and computed tomographic abnormalities into single-sector (n = 19), multisector (n = 11), and top-of-the-basilar (n = 27) groups; a sector was defined as that portion of the brain stem supplied by a single penetrating (median) or branch (paramedian or lateral) artery. RESULTS: Thirty-day and 3-year survival rates were 100% and 71%, respectively, in the single-sector group, and 96% and 73%, respectively, in the top-of-the-basilar group. Thirty-day and 3-year stroke recurrence free survival rates were 89% and 76%, respectively, in the single-sector group, and 96% and 88%, respectively, in the top-of-the-basilar group. Seven of the 11 patients in the multisector group died within 2 months of ictus, three having experienced recurrence. CONCLUSIONS: These data, in part supported by prior studies, demonstrate the feasibility and heuristic value of the classification scheme and suggest that single-sector and top-of-the-basilar stroke patients have a relatively benign early prognosis and modest long-term stroke rates.

Actuarial Analysis↗
PubMed1992

Influences on cigarette smoking quantity. Selection, stress, or culture?

The selection, job stress, and job culture models of the association between occupation and smoking quantity were empirically evaluated in a random sample of 556 employed smoking adults in Orange County, California. Almost three quarters of the sample were heavy smokers (20 or more cigarettes per day). The largest percent of heavy smokers were blue-collar workers (77%). Age, sex, ethnicity, and the industry in which one works were all associated with heavy smoking, implying that selection and culture models contribute to smoking behavior. For example, men had twice the odds of being heavy smokers than did women, and Anglos had almost two and a half times the odds of being a heavy smoker than did non-Anglos. Smokers employed in the service, financial, insurance, and retail industries were one fourth as likely to be heavy smokers as those employed in the public administration sector. Smokers employed in the public administration sector had the highest percent of heavy smokers (88.9%). Job stress was not associated with heavy smoking compared with light smoking. Smoking cessation and prevention programs should address the social and job cultures in which the behavior occurs. Job-culture models of intervention should include elements that focus on individual coping mechanisms involving susceptibility to social pressure; social environment models imply that change in organizational culture is necessary.

Adult↗
PubMed1992

Multidrug resistant typhoid fever: therapeutic considerations.

Forty six blood culture positive cases were studied during the current outbreak of multidrug resistant typhoid fever (MRTF). The present outbreak was caused by E1 phage type and organisms were resistant to all commonly used drugs for the treatment of typhoid fever, viz., chloramphenicol (78%), co-trimoxazole (76%) and ampicillin (68%). Treatment failures with chloramphenicol (45.5%) corroborated well with in vitro resistance. No treatment failure was seen with chloramphenicol and ceftriaxone, when these drugs were used in cases infected with sensitive strains. Among the alternative drugs used in cases with in vitro sensitivity, successful clinical response was seen with ceftriaxone (4/4) and cefotaxime (8/9) as compared to cephalexin (3/5) or a combination of cephalexin and furazolidone (9/12).

Ampicillin Resistance↗
PubMed1992

Niemann-Pick disease presenting as hepatic disorder.

A 2 year old female child with Niemann-Pick disease was referred as case of chronic liver disease; clinically, she had neurological involvement. Liver biopsy showed Niemann-Pick cells. Hepatic manifestations of Niemann-Pick disease as seen in nine cases reported from India are discussed.

Child, Preschool↗
PubMed1991

Transcription of Clostridium thermocellum endoglucanase genes celF and celD.

Transcripts of the Clostridium thermocellum endoglucanase genes celF and celD, encoding endoglucanases F and D, respectively, were characterized. The size of the mRNAs was about 2.35 kb for celF and 2.1 kb for celD, indicating monocistronic transcription of both genes. A unique 5' end, located 218 bp upstream from the initiation codon, was found for celF mRNA. No convincing homology could be identified between the sequence upstream from the celF 5' end and other procaryotic promoters. Two 5' ends, located 124 and 294 bp upstream from the initiation codon, were mapped for celD mRNA. The -10 and the -35 sequences preceding the ATG-distal 5' end of celD mRNA were homologous to the consensus sequence of Bacillus subtilis sigma 43 promoters. The sequence upstream from the ATG-proximal 5' end had some similarity with the -10 sequence of B. subtilis sigma 28 promoters. During growth on cellobiose, the 5' end of celD transcripts was found predominantly at the -124 site during the late exponential phase but almost exclusively at the -294 site during the early stationary phase. The kinetics of appearance of celA, celC, celD, and celF mRNA was followed by dot blot analysis. Transcripts of celA, celD, and celF were detected during late exponential and early stationary phase. In contrast, the celC transcript was detected almost exclusively during early stationary phase. Since growth was limited by the availability of cellobiose, the results suggest that the genes are regulated by a mechanism analogous to catabolite repression.

Amino Acid Sequence↗