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Biomedical subjects

S Sharma

Publications and source records attributed to S Sharma.

At least 1,171 records · Page 65Linked to original sources
PubMed1989

Balloon mitral valvotomy. A new technique.

Balloon mitral valvotomy is a new technique for non-operative treatment of mitral stenosis and is performed by using single or double balloon. The technique is complex, involves transseptal puncture, however, can be safely performed in experienced catheterisation laboratory. The technique has been applied in calcific and noncalcific valves, mitral restenosis and also in presence of atrial fibrillation. The results with double balloon valvotomy at the present time is costlier than closed mitral valvotomy. The technique is promising and large trials are awaited to see its future status.

Blood Pressure↗
PubMed1989

Effect of denervation on loss of ions in chick skeletal muscle.

Leaching behaviour of chick gastrocnemius muscle has been studied with respect to the loss of Na+, K+ and Ca2+ ions in a donor-solvent (muscle-water) system under normal as well as denervated conditions. An attempt has been made to explain the alterations in the rate of electrolytic loss in terms of membrane dysfunctions induced as a result of loss of neural control.

Animals↗
PubMed1989

Comparative antifilarial efficacy of the N-oxides of diethylcarbamazine and two of its analogues.

The N-oxides of 1-diethyl carbamoyl-4-methyl piperazine (DEC), 3-ethyl-8-methyl, 1,3,8-triazabicyclo (4,4,0) decan-2-one (centperazine) and 1-methyl-4-(pyrrolidin-1-yl-carbonyl) piperazine (CDRI Comp. 72/70) have been evaluated against Limotosoides carinii infection in cotton rats to establish whether conversion of the three antifilarials into N-oxides would lead to exertion of better antifilarial activity. Of the three N-oxides, N-oxide of DEC showed significantly more suppressive effect on circulating microfilariae in comparison to its parent compound. However, adult worms were unaffected. It was observed that basicity of the N-CH3 group did not play major role in exertion of activity of DEC and related compounds. Nevertheless, two other N-oxides were inactive.

Animals↗
PubMed1989

Evaluation of coagglutination test for serotyping of enteropathogenic bacteria.

Results of conventional agglutination and coagglutination (COA) tests for serotyping of enteropathogenic Escherichia coli (EPEC), Shigella, Salmonella and Vibrio cholerae were compared. Eighty isolates of different serotypes of EPEC falling in the Wellcome polyvalent (OK) 2, 3 and 4 antisera, showed good (4+) agglutination with COA reagent up to 1:960 dilution. Out of 50 strains of Shigella species tested, 25 of Sh. dysenteriae and 5 of Sh. sonnei gave good reaction up to 1:1920 dilution and 15 of Sh. flexneri up to 1:960 dilution in COA test. Similar reaction (4+) by 5 strains of Sh. boydii was seen up to 1:480 dilution only. All 100 isolates of different Salmonella species viz., S. paratyphi A (5), S. typhimurium (50), S. typhi (15), S. weltevreden (5) and S. senftenberg (25), when serotyped by COA, gave good reaction in 1:480 dilution except S. typhi factor 9 and dH antisera, which gave very weak reaction at 1:480 dilution and good reaction at 1:280 dilution. All seven isolates of V. cholerae gave good reaction in COA test even up to 1:1920 dilution. No cross reaction with any COA reagent was obtained in the 1206 heterologus isolates tested. Thus due to its higher efficiency, lower cost and good specificity, COA may prove to be a better method for serotyping of enteropathogens.

Agglutination Tests↗
PubMed1989

Alterations in phospholipid content of chick skeletal muscle under stress conditions.

Alterations in the phospholipid levels of three gastrocnemii (G. externus, G. medius and G. internus) of chick have been studied during 56 days postembryonic growth of the three muscles. The effects of denervation and work-overload stress on their phospholipid content during the same period have been discussed in the light of denervation-induced membrane breakdown and exercise-induced fibre hypertrophy.

Animals↗
PubMed1989

False-negative IV-DSA in external jugular phlebectasia.

We report a patient with external jugular phlebectasia in whom we performed intravenous digital subtraction angiography but failed to demonstrate the lesion. Direct injection of contrast into the lesion is the preferred method of radiological demonstration.

Adult↗
PubMed1989

Characterization of the ros1-gene products expressed in human glioblastoma cell lines.

Most glioblastoma-derived cell lines express an 8.3 kb ros1 transcript and a 280 kD glycoprotein designated gp280ros1, which can be specifically immunoprecipitated with an anti-ROS antibody. This 280 kD protein possesses in vitro autokinase activity and was observed in four independent glioblastoma cell lines. In a fifth glioblastoma cell line, U-118 MG, a smaller ros1 transcript of 4.0 kb was observed. Immunoprecipitation analysis reveals that the U-118 MG expressed a smaller, 116 kD ros1 gene product. cDNA cloning and sequencing of the U-118 MG ros1 transcript indicates it encodes the entire tyrosine kinase domain and two amino acids of the transmembrane domain of ros1 at its 3' end. Sequences at its 5' end likely arise from another gene.

Amino Acid Sequence↗
PubMed1989

Drainage after elective cholecystectomy: a prospective study.

Prospective analysis of 100 consecutive patients who underwent elective cholecystectomy with drainage over a one year period is presented. Drainage after cholecystectomy detected bleeding and bile leak in four patients. Conservative management of bile leak was adequate in two patients while one patient with bleeding required re-exploration. Drainage did not increase morbidity in the form of wound infection, hospital stay or rate of other complications. After cholecystectomy routine drainage through the right flank is recommended.

Adult↗
PubMed1989

Cardiac tamponade as a presentation of mucoepidermoid bronchogenic carcinoma.

We report a young patient who had massive pericardial effusion and tamponade diagnosed clinically and by echocardiography as the presenting manifestation of underlying malignancy. Pericardial and lymphnode biopsy revealed features of mucoepidermoid carcinoma and bronchoscopy localised the primary to be in the left main bronchus.

Adult↗
PubMed1988

The amyloid percursor protein of Alzheimer disease is expressed as a 130 kDa polypeptide in various cultured cell types.

The vascular and parenchymal amyloid deposits in Alzheimer disease (AD), normal aging and Down syndrome are mainly composed of a 4 kDa polypeptide (A4), which derives from a larger precursor protein (APP). There is evidence that APP is a transmembrane glycoprotein present in most tissues, but the characteristics of APP in intact cells are not yet known. In order to investigate this issue, we examined the immunoreactivity of fibroblasts of human and nonhuman cell lines with antisera raised to synthetic peptides corresponding to A4 and to two other domains of the APP. All three antisera recognized a 130 kDa polypeptide (APP-130) in immunoblots from all cell lines. In fibroblasts, an additional polypeptide of 228 kDa (APP-228) was recognized by the antiserum to A4. In immunoblots of two dimensional gels, APP-130 showed a pI of 6.2, while APP-228 failed to focus in the pH range of 4.7-7.0. Sequential extractions of cells with buffer and with Triton X-100 indicate that APP-130 is extractable with nonionic detergents at high ionic strength, whereas 228 kDa APP is a cystolic component. Immunofluorescence staining is consistent with an intracellular perinuclear and plasma membrane localization. It is concluded that APP-130 and APP-228 are two forms of the APP which result from extensive posttranslational modifications of a smaller original gene product. It is likely that APP undergoes similar posttranslational modifications in different cell types.

Alzheimer Disease↗
PubMed1988

Sequence analysis and regulation of the htrA gene of Escherichia coli: a sigma 32-independent mechanism of heat-inducible transcription.

Previous work has established that the E. coli htrA gene product is essential for bacterial survival at temperatures above 42 degrees. We have sequenced the htrA gene region and found an open reading frame (ORF) coding for a protein of 491 amino acids with a calculated molecular weight of 51,163 daltons. This molecular weight corresponds well with that seen following electrophoresis on SDS-polyacrylamide gels. This protein has an amino-terminal sequence typical for a leader peptide and undergoes post-translational modification by cleavage of an amino-terminal portion. The insertional mutations which affect the function of the htrA gene map inside this ORF. The levels of htrA mRNA increase rapidly and transiently upon heat shock in a manner independent of the rpoH gene, which encodes the sigma 32 RNA polymerase subunit and is known to regulate transcription of typical heat shock genes. Using S1 mapping and RNA primer extension, we have identified the htrA promoter and found that it is similar to the P3 promoter of the rpoH gene. The P3 promoter is especially active at high temperatures and is recognized by a recently identified transcriptional factor, sigma E.

Amino Acid Sequence↗
PubMed1988

Molecular events during B lymphocyte differentiation. Induction of endogenous mouse mammary tumor proviral envelope transcripts after B cell stimulation.

We have identified a gene whose expression appears to be associated with a late stage in the differentiation of B lymphocytes into antibody secreting cells, as shown by using the inducible B cell lymphoma, CH12. Restriction mapping and partial sequencing of a cDNA clone isolated by subtraction analysis demonstrated that the clone, SC34, represents an envelope (env) gene transcript of a mouse mammary tumor virus (MMTV). In CH12 cells and in normal B cells, levels of MMTV RNA were increased after stimulation with LPS. The env transcript was the predominant MMTV RNA species and increased more dramatically than did levels of the genomic transcript. In differentiating CH12 cells, env transcripts increased as much as 20-fold above levels found in replicating, antibody nonsecreting CH12 cells. The major increase in expression appeared to be associated with B cell differentiation and not replication. By Southern blot analysis, only bands characteristic of endogenous proviruses were found in CH12, indicating that viral sequences were not amplified in this cell line. Restriction mapping indicated that the SC34 cDNA clone was a product of the Mtv-9 locus. Mtv-9 previously was shown to encode a complete MMTV provirus on chromosome 12, on which Ig heavy chain genes also are located. Increases in MMTV transcripts followed distinct kinetics and were quantitatively different from changes in immunoglobulin gene products. The expression of env RNA appears to more accurately reflect differentiation to antibody secretion in CH12 cells than does the expression of immunoglobulin gene transcripts.

Animals↗
PubMed1988

Postnatal development and environmental regulation of hippocampal glucocorticoid and mineralocorticoid receptors.

We report here on developmental changes in [3H]RU 28362 (glucocorticoid receptor) and [3H]aldosterone (mineralocorticoid receptor) binding capacity in soluble fractions prepared from hippocampal tissue. [3H]RU 28362 binding was low on Day 3 of life (less than 30% of that observed in adults) and increased towards adult values during the second and third weeks of life, a pattern virtually identical to that previously reported for dexamethasone binding. In contrast, [3H]aldosterone binding on Day 3 of life was only slightly lower than that observed in adults and reached adult values by Day 7. Postnatal handling of rat pups, which has been shown to increase dexamethasone binding in hippocampus, resulted in a significant increase in [3H]RU 28362 binding capacity in hippocampus, but had no effect on [3H]aldosterone binding.

Adrenalectomy↗
PubMed1988

Association of coronary calcification with obstructive disease in coronary arteries in Indian patients.

A total of 1150 consecutive patients (1052 males and 98 females; age 51.2 +/- 10.1 years) with suspected coronary artery disease (Group I) were subjected to fluoroscopy for detection of coronary artery calcification (CAC) and coronary angiography. Another group (Group II) of 120 patients (95 males and 25 females; age 51.4 +/- 9.4 years) catheterized for cardiac diseases other than coronary artery disease (CAD) were subjected to the same protocol of fluoroscopy and coronary angiography to exclude incidental CAD in view of their age. CAC was present in 240 patients (20.0%) in Group I. Of these, 200 (83.4%) had triple-vessel disease (TVD); 20 (8.3%) had double-vessel disease (DVD); 19 (7.9%) had single-vessel disease (SVD); and 37 (15.4%) patients had left main coronary disease (LMCAD). Only one of these patients had insignificant CAD considered as "normal" coronary arteries (NC). Incidence of LMCAD, TVD, DVD, SVD, and NC in patients without CAC was 4.4%, 56.3%, 18.2%, 14.0%, and 11.5%, respectively. Incidence of CAC in patients with LMCAD, TVD, DVD, SVD, and NC was 48.1%, 28.1%, 10.8%, 13.0%, and 1.0% respectively. In Group II (n = 120), 24 patients (20%) had CAD, CAC was present in 5 patients with CAD (20.9%), and in two patients without CAD (2%). CAC is relatively uncommon in Indian CAD patients. Its presence, however, indicates severe multivessel disease.

Adult↗
PubMed1988

Expression of CD23 antigen is not necessary for human 12-kDa B cell growth factor-mediated B cell proliferation.

In an attempt to understand the relationship between the CD23 antigen and the human 12-kDa B cell growth factor (BCGF) receptor, we have undertaken studies to define the biological efficacy of 12-kDa-BCGF on CD23+ (Raji) and CD23- (P3HR1) human Burkitt B cell lines. Our results show that recombinant 12-kDa-BCGF can induce efficient [3H]thymidine incorporation and proliferation in cells of either phenotype. These results strongly suggest that a functional receptor for the 12-kDa-BCGF may exist independently of the CD23 molecule.

Antigens, Differentiation, B-Lymphocyte↗