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Biomedical subjects

S Sharma

Publications and source records attributed to S Sharma.

At least 1,009 records · Page 56Linked to original sources
PubMed1991

Concurrent double balloon valvotomy for combined rheumatic mitral and tricuspid stenosis.

We expanded the application of percutaneous balloon valvotomy (PBV) to 4 adults (age 14 to 30 years, average 22.2 years) with combined rheumatic mitral and tricuspid stenosis. Double balloon dilatation reduced the transmitral gradient from 17.36 +/- 3.54 to 5.52 +/- 0.89 (P less than 0.025) and transtricuspid gradient from 12.65 +/- 2.67 to 3.67 +/- 0.95 (P less than 0.025). Mitral and tricuspid valve area increased from 0.73 +/- 0.20 to 2.57 +/- 0.67 (P less than 0.005) and from 0.77 +/- 0.24 to 2.67 +/- 0.24 cm2 (P less than 0.005), respectively. The procedures were well tolerated, with no significant increase in valvular regurgitation or left to right shunt across the atrial septum. The excellent symptomatic and haemodynamic benefits are sustained at 3-24 months follow-up. It is concluded that combined dilatation of stenotic valves by double balloon technique can emerge as an alternative to surgery in selected patients with polyvalvar rheumatic heart disease.

Adolescent↗
PubMed1991

Differential inhibition of interleukin 2- and interleukin 4-mediated human B cell proliferation by ionomycin: a possible regulatory role for apoptosis.

Surface immunoglobulin (Ig) cross-linking by anti-IgM (mu) antibodies leads to B cell activation resulting in numerous early biochemical events including an increase in intracellular [Ca2+]. Furthermore, anti-mu-activated B cells become able to proliferate in response to interleukin (IL)2 and IL4. These studies examined the effect of the calcium ionophore ionomycin, an enhancer of cytoplasmic [Ca2+] levels, on IL2 and IL4-mediated proliferation of anti-mu-stimulated normal human B cells. Ionomycin inhibited the proliferative response of anti-mu-activated B cells to IL4. In contrast, IL2 and phorbol 12,13 dibutyrate (PBu2)-mediated B cell proliferation was refractory to the growth inhibitory effects of ionomycin. In an attempt to delineate a possible mechanism(s) for this differential growth effect of ionomycin, we first studied direct effects of ionomycin on activated B cells. Our data suggested that ionomycin induced DNA fragmentation in anti-mu-costimulated B cells. Interestingly, in contrast to PBu2, IL4 did not prevent ionomycin-dependent DNA fragmentation. Importantly, H7, an inhibitor of protein kinase C activation, down-regulated only the IL2 and PBu2-driven B cell proliferation but not B cell proliferative response to IL4. These results suggest that putative protein kinase C activation, either by direct treatment with phorbol ester or during IL2 signaling, counteracts the inhibitory effects of ionomycin. In contrast, IL4 signaling does not exhibit the same protective properties.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed1991

Thoracoscopy in the diagnosis of pleural effusion of ambiguous etiology.

Between 1985 and 1989, 27 patients underwent thoracoscopy for an undiagnosed pleural effusion. Prior thoracocentesis (in all patients) and a needle pleural biopsy (in 15 patients) had been nondiagnostic. The rigid thoracoscope was used in 21 patients, the cystoscope in 4 patients, and the flexible bronchoscope in 2 patients. We had one mortality, and there was no operative morbidity. Thoracoscopy was diagnostic in 24 of the 27 patients (4 benign, 20 malignant). The average duration of stay in the hospital was 48 hr. We conclude that thoracoscopy is an important diagnostic aid in the management of a pleural effusion of ambiguous origin and that it is a relatively safe procedure that can be performed with an acceptable morbidity and mortality.

Aged↗
PubMed1991

Guinea pig proacrosin is synthesized principally by round spermatids and contains O-linked as well as N-linked oligosaccharide side chains.

Proacrosin is the zymogen precursor of acrosin, a sperm protease believed to play an essential role in fertilization. In this study, we used primary cultures of guinea pig spermatogenic cells to examine the temporal appearance and mechanisms of synthesis and processing of proacrosin during acrosome development. Following [35S]methionine incorporation and immunoprecipitation, cultured spermatogenic cells were found to synthesize two forms of proacrosin (Mr 54,000 and 57,000). Proacrosin was synthesized mainly by round spermatids. By immunoblotting, proacrosin became very prominent in round spermatids and persisted throughout spermiogenesis. Pulse-chase experiments demonstrated that the Mr 54,000 form of proacrosin was converted to the Mr 57,000 form, presumably reflecting posttranslational processing of carbohydrate side chains. When spermatogenic cells were cultured in the presence of tunicamycin, the synthesized proacrosin had an Mr of 54,000. However, in vitro translation of mRNA extracted from guinea pig testis followed by immunoprecipitation indicated that the core polypeptide of proacrosin has an Mr of 44,000. Guinea pig spermatogenic cells incorporated glucosamine and fucose into the oligosaccharides of proacrosin. Treatment of guinea pig testis proacrosin with N-glycosidase or O-glycosidase reduced the Mr by 3-7%. These results indicate that proacrosin is synthesized by postmeiotic cells and the enzyme contains N- and O-linked oligosaccharides.

Acrosin↗
PubMed1991

Maturation of guinea pig sperm in the epididymis involves the modification of proacrosin oligosaccharide side chains.

Proacrosin from guinea pig cauda epididymal sperm has a lower molecular weight compared with the testicular zymogen. In this study, we have examined the structural basis of this change and where the conversion in proacrosin molecular weight occurs during sperm maturation. Immunoblotting of trifluoromethanesulfonic acid-deglycosylated testicular and cauda epididymal sperm extracts with antibody to guinea pig testicular proacrosin demonstrated that the polypeptide backbones of proacrosins from the testis and cauda epididymal sperm had the same molecular weights (approximately 44,000). Keratanase, an endo-beta-galactosidase specific for lactosaminoglycans, partially digested testicular proacrosin but had no effect on proacrosin from cauda epididymal sperm. In extracts of testis, caput epididymis, and corpus epididymis analyzed by immunoblotting, anti-proacrosin recognized a major antigen with an apparent molecular weight (Mr) of 55,000, although a 50,000-Mr minor antigen began to appear in the corpus epididymis. By contrast, extracts of cauda epididymis, vas deferens, and cauda epididymal sperm had the 50,000 Mr protein as the only immunoreactive antigen. By enzymography following electrophoresis, the major bands of proteolytic activity in extracts of testis, caput epididymis, and corpus epididymis had 55,000 Mr. A band of protease activity with 55,000 Mr also appeared in extracts of the corpus epididymis. However, the most prominent bands of proteolytic activity in cauda epididymis, vas deferens, and cauda epididymal sperm had 50,000 Mr. In addition, two other major protease activities were detected with 32,000 and 34,000 Mr; the relationships of these proteases to proacrosin are unclear. From these results, we conclude that the oligosaccharides of proacrosin are altered during epididymal transit and that this modification occurs in the corpus epididymis.(ABSTRACT TRUNCATED AT 250 WORDS)

Acrosin↗
PubMed1991

Serum soluble interleukin-2 (IL-2) receptor levels in women with breast carcinoma and its correlation with IL-2 receptor expression on blood lymphocytes and lymphocytic infiltration within the tumour.

This study describes serum levels of soluble interleukin-2 receptor (sIL-2R) in 13 healthy women, 10 women with breast dysplasia and 37 patients with breast carcinoma. A difference was found between sIL-2R levels in normal women and cancer patients. sIL-2R increased with the advance in stage of cancer but the extent of increase fell from stage III to stage IV as compared to the change from stage II to stage III. Of the 15 patients who were followed after surgery and/or therapy, 10 (67%) showed a fall in the serum sIL-2R levels. A negative correlation was found between sIL-2R levels and lymphocytic infiltration only within the malignant tissue. These findings probably indicate that sIL-2R exerts an immunomodulatory effect on blood lymphocytes by preventing their infiltration into the tumour tissue. To our knowledge, this is the first report of its kind in immunology of breast carcinoma.

Adolescent↗
PubMed1991

Altered hemolysin production in urine-grown uroisolates of Escherichia coli.

Fifteen uroisolates of E. coli were studied for both cell-free and cell-bound hemolysin production. Estimations were done in Trypticase soy broth (TSB, providing iron-replete medium) TSB + 2,2'-bipyridine (providing experimentally created iron-depleted conditions) and pooled normal human urine (providing natural iron-depleted growth medium). In TSB 40% of strains showed no detectable cell-free hemolysin, they were able to produce it in the presence of 2,2'-bipyridine and more so when grown in urine. The cell-bound hemolysin was produced by all the strains in TSB, but in the presence of 2,2'-bipyridine and urine an insignificant increase was observed. All the strains when given 2nd and 3rd passage in urine, were found to elaborate significantly more cell-free as well as cell-bound hemolysin.

Bacterial Proteins↗
PubMed1991

Cardiac involvement in nonspecific aortoarteritis (Takayasu's arteritis).

Fifty-four patients (18 males and 36 females, ages 2 to 37 years) with nonspecific aortoarteritis (NSAA) were studied. Evaluation revealed hypertension in 35, congestive heart failure (CHF) in 24, mild to moderate mitral regurgitation in six, and mild aortic regurgitation in two. Erythrocyte sedimentation rate was raised (greater than 35 mm in the first hour) in 38 patients. The arterial lesions included type I in seven, type II in eight, and type III in 34. Pulmonary artery involvement was present in 4 (type IV) of the 20 patients in whom it was studied. Selective coronary angiography was done in 11 patients and revealed 90% left main stenosis in one patient. Hemodynamic data revealed raised (greater than 7 mm Hg) mean right atrial pressure in nine, raised mean pulmonary artery pressure (greater than 20 mm Hg) in 29, and raised left ventricular filling pressure (greater than 12 mm Hg) in 27 patients. Radionuclide ventriculography revealed reduced (less than 45%) left ventricular ejection fraction (LVEF) in 27 patients. The myocardial morphology as evaluated on right ventricular endomyocardial biopsy revealed normal histology in nine, features of inflammatory myocarditis in 24, and nonspecific changes suggestive of dilated cardiomyopathy in six patients. Marked right ventricular endocardial thickening was present in three. All patients with CHF had some histologic abnormality. We emphasize that myocardial involvement including myocarditis is common in NSAA and may precipitate CHF in these patients.

Adolescent↗
PubMed1991

Experience with a potent LH-RH agonist, buserelin, alone and in combination with testosterone for antispermatogenic activity, reversibility and toxicity in langur monkey.

Chronic intermittent treatment of LH-RH superagonist Buserelin alone or in combination with testosterone enanthate were given to adult male langurs for 90 days to evaluate antispermatogenic activity of alone and combination therapy, maintenance of normal androgenicity, possible toxic effects of agonist treatment, related side effects of testosterone supplementation and complete reversibility of the procedure. A gradual decrease in sperm count was recorded in both treatment groups, along with reduced motility and vitality of the spermatozoa. In the combination group, oligospermia was achieved in 4 out of 5 animals, whereas, only 2 animals became oligospermic in the agonist alone group. Significant decrease in serum testosterone levels along with impaired libido and other testosterone withdrawal symptoms were observed in the Buserelin alone group, conversely normal testosterone levels and libido were observed in the combination group. An elevation in haematological variables and serum total protein concomitant with a slight gain in body weight of the animals were recorded in the combination group; these changes were not encountered in the agonist alone group. Reversibility of all the altered parameters to control range was observed in both treatment groups following 75 to 90 days of treatment withdrawal.

Acid Phosphatase↗
PubMed1991

Noninvasive preoperative localization of an intracardiac bullet.

A 40-year-old patient with intracardiac gunshot injury is reported. The bullet was localized preoperatively within the pericardium at the junction of the right atrium and the inferior caval vein and was removed successfully at surgery. The role of various imaging techniques in the preoperative localization of intracardiac missiles is discussed.

Adult↗
PubMed1991

Probe angioplasty through an intracoronary probing catheter in lesions which are difficult to cross.

The clinical records of the first 17 consecutive patients (20 lesions) in whom percutaneous transluminal coronary angioplasty was done using the ultra-low profile "balloon-on-wire probe" passed through an intracoronary probing catheter were reviewed. All patients had high-grade "difficult" lesions. In 15 lesions (12 patients) other balloon systems (over-the-wire low profile balloons (n = 9), and balloon-on-wire used alone, (n = 6)) had failed to cross the lesion. Acute ischemia due to complete occlusion at the site of the lesion during attempts to cross was seen in 3 of these patients. The intracoronary probing catheter was used to deliver the probe across the lesion in all these cases. Successful dilatation was achieved in 14 lesions (93%). In 5 lesions (5 patients) this combination was used as the initial strategy. Three of these had chronic total occlusions. Successful dilatation was achieved in 3 lesions (60%) using this combination and in 1 lesion over-the-wire balloon finally succeeded. There was 1 failure. The intracoronary probing catheter in combination with probe balloon wire offers a promising method to increase the success rate in patients with high grade "difficult" lesions. This combination is especially useful in situations where other balloon systems fail to cross the lesion.

Angioplasty, Balloon, Coronary↗
PubMed1991

Coarctation of aorta with unusual association of diverticulum of the left ventricle and double orifice mitral valve.

We describe a case of coarctation of aorta with two unusual associated anomalies, namely, a diverticulum of the left ventricle and double orifice of the mitral valve. Echocardiography and colour flow mapping precisely diagnosed the bridging tongue of leaflet tissue responsible for the double orifice of the mitral valve. Balloon angioplasty for coarctation produced dramatic benefits which are sustained at follow-up. The other two lesions caused no haemodynamic abnormality.

Adolescent↗
PubMed1991

"Anatomically corrected malposition": a rare case with bilateral absence of a complete subarterial muscular infundibulum.

A unique case of anatomically corrected malposition of great arteries with a bilateral absence of a complete subarterial muscular infundibulum is presented. The other unusual feature of the case was absence of any complex associations and interestingly an intact ventricular septum. The presenting lesion was valvar pulmonary stenosis and balloon valvotomy could not be achieved because of abnormal relationship of the great vessels.

Adult↗
PubMed1991

The morphology of coronary arterial dissection occurring subsequent to angioplasty and its influence on acute complications.

We reviewed the records of 402 patients undergoing percutaneous transluminal coronary angioplasty to identify factors predicting an ischemic event with arterial disruption during an otherwise uncomplicated angioplasty. Major dissection of the coronary arteries without immediate occlusion was found in 25 patients, who exhibited 28 dissected lesions. Dissections were classified into 2 types: those producing a continuous extraluminal and parallel filling tract, and those with a continuous parallel filling tract extending into and compromising the lumen. Ischemic complications (defined as myocardial infarction, the need for repeat angioplasty, or coronary arterial bypass surgery) occurred in 6 patients (24%) within 24 hours of the completion of the procedure. The remaining 19 patients had an uncomplicated hospital course. Acute ischemic complications following dissection correlated with the percentage of luminal compromise 50 +/- 0% in those with complications as opposed to 17 +/- 21% in those without: P less than 0.001) and the development of dissection producing a filling tract which compromised at least half the lumen (100% in those with complications versus 9.1% in those without: P less than 0.001). There was a trend towards an increase in ischemic complications in patients with proximal and eccentric lesions. We conclude that patients who develop dissections which produce significant luminal compromise after an otherwise uncomplicated angioplasty are at a high risk of developing an acute ischemic complication within 24 hours of the procedure.

Acute Disease↗