PubMed HealthSearch

Biomedical subjects

B Sharma

Publications and source records attributed to B Sharma.

At least 37 records · Page 2Linked to original sources

Six-year survival of patients with and without painless myocardial ischemia and out-of-hospital ventricular fibrillation.

Out-of-hospital ventricular fibrillation (OHVF) is the most common cause of sudden cardiac death. Of 1,070 patients with OHVF who entered this study, 150 were discharged alive. Of this group, 120 were free of anoxic brain damage. Of these survivors, 67 (57%) had no previously demonstrated anginal symptoms. Treadmill stress testing revealed painless ST depression in 76% of these neurologically intact patients. Exercise ventriculography in a subset of 9 patients without angina before OHVF and in 6 patients with typical anginal symptoms revealed marked left ventricular dysfunction with ST depression in the absence of chest pain in all 15 patients. Sublingual nitroglycerin reversed this evidence of ischemia in the asymptomatic patients. Patients were followed for 6 years after discharge. No statistical difference in mortality could be demonstrated for patients who had previous anginal symptoms vs those who did not, nor was age a predictor of mortality. Women had the same risk of death as men at 2 years after OHVF, but a significantly higher risk by year 6. Myocardial infarction associated with OHVF did not predict lower mortality throughout the study.

Death, Sudden

Detection of goat pox antigen and antibody by the counter immunoelectrophoresis test.

The counterimmunoelectrophoresis (CIE) test was standardised for the detection of goat pox antigen and antibody using inactivated antigens. The chloroform inactivated and live antigens were equally sensitive for detection of goat pox precipitins. The precipitinogens of goat pox virus (GPV) were found to be soluble in nature. The CIE test was quick as well as more sensitive than the agar gel precipitation test for detection of GPV antibody/antigen. The CIE employing inactivated antigen has been used for the first time in the detection of GPV antibodies/antigens.

Animals

Stability of oral polio vaccine at different temperatures.

The stability of five batches of oral polio vaccine stored at -20, 4-8, 22 and 36 degrees C for 7, 14 and 21 days was studied. The virus titrations were performed by the standard macro-method. There was little loss in virus titre when samples were kept at -20 and 4-8 degrees C for 21 days, whereas the samples exposed to 36 degrees C for 21 days showed almost complete loss in virus titre. The average loss in virus titre in a year (log TCID50) was 0.47 at -20 degrees C and 0.65 at 4-8 degrees C when various samples were stored at these temperatures. At 22 degrees C the average loss in virus titre after 21 days was about 1.50. The samples subjected to ten cycles of freezing and thawing did not show any loss in virus titre. Likewise there was not much loss in virus titre in three samples stored at 4-8 degrees C for a year. Oral polio vaccine stabilized with magnesium chloride is quite a stable vaccine and maintenance of a proper cold chain is recommended for the delivery of a potent vaccine in countries with high ambient temperature.

Drug Stability

Percutaneous transluminal coronary angioplasty of one vessel for refractory unstable angina pectoris: efficacy in single and multivessel disease.

Forty patients with unstable angina refractory to medical treatment had one vessel percutaneous transluminal angioplasty to the most stenotic lesion in a major coronary artery. The procedure was successful in 35 patients, and the remaining five patients underwent emergency coronary artery bypass graft surgery. The initial success rate (84%) for the 16 patients with single or the 19 patients with multivessel disease (90%) was similar. At early follow up (average nine days) all patients with successful angioplasty remained symptomatically improved; 10 patients (83%) with single and 10 patients (63%) with multivessel disease had negative treadmill stress tests. Five of six cardiac events occurred within the intermediate (average 11 months) follow up period; two patients had recurrent refractory unstable angina, two had angioplasty for progression of disease in a vessel not previously treated by angioplasty, and one had bypass graft surgery. During late (average 26 months) follow up one patient had a non-fatal myocardial infarction while seven patients (58%) with single vessel disease and nine patients (75%) with multivessel disease had negative stress tests; 29 of 40 patients showed long term improvement.

Adult

Inhibition of the generation of cytotoxic lymphocytes by potassium ion channel blockers.

Recent studies with patch-clamp technique have shown the presence of voltage-gated K+ channels in human T lymphocytes and natural killer cells. Blockers of voltage-gated K+ channel currents (4-Aminopyridine, 4-AP, and tetraethylammonium, TEA), were used here in a pharmacological approach to examine a role of K+ channels in the differentiation of precursors of cytotoxic cells into functionally active cytotoxic lymphocytes. The data presented here demonstrated that activation of peripheral blood lymphocytes with CCRF-HSB-2, 3163 and other allogeneic lymphoid cells for 5 days in mixed lymphocyte culture (MLC) renders them cytotoxic to the respective target cells. Both 4-AP and TEA (2-4 mM), when added to cultures, inhibited the development of cytotoxic effectors in a dose-dependent manner. Maximum inhibition of the generation of cytotoxic lymphocytes occurred when 4-AP was present at the start of cultures. Little or no inhibition was, however, observed when 4-AP was added 1 day of incubation. The results also demonstrate that the addition of recombinant IL-2 (rIL-2) overcame the 4-AP- or TEA-mediated inhibition of the generation of cytotoxic lymphocytes in a dose-dependent manner. The maximum reversal of 4-AP-induced inhibition occurred when exogenous IL-2 was added at Day 0 or 1. Taken together, these data suggest a role of K+ channels in the generation of cytotoxic lymphocytes.

4-Aminopyridine

Application of ELISA in the detection of goat pox antigen and antibodies.

Enzyme linked immunosorbent assay (ELISA) was standardized for detection of goat pox virus (GPV) antibodies and antigen using live and inactivated antigens and hyperimmune serum (HIS), convalescent, post-vaccinal, as also post-challenge sera. The ELISA was most sensitive in detection of antibody when compared with agar gel precipitation (AGP) and counterimmunoelectrophoresis (CIE) tests. There was no complete correlation between the antibody status of vaccinated goats and protective immunity as animals having detectable seroconversion were also solidly immune to virulent challenge. The application of ELISA in pox infections of goats has been discussed.

Animals

Detection of rinderpest antigen by latex agglutination test.

A slightly modified latex agglutination test was applied for detection of rinderpest antigen. The antigen was added to sensitized latex particles in the presence of hyperimmune antiserum to facilitate agglutination. Out of 129 samples tested by latex agglutination (LA), solid phase aggregation of coated erythrocytes (SPACE), reverse phase passive haemagglutination (RPHA) and counter immunoelectrophoresis (CIE) test, 86.0, 86.8, 84.4 and 79.8 per cent, respectively, were found positive.

Antigens, Viral

Demonstration of exercise-induced painless myocardial ischemia in survivors of out-of-hospital ventricular fibrillation.

To ascertain if myocardial ischemia is the mechanism of out-of-hospital ventricular fibrillation (VF), left ventricular (LV) function was assessed at rest and during submaximal exercise in 15 patients who survived out-of-hospital VF. They were separated into asymptomatic (9 patients, group A) and symptomatic (6 patients, group S) groups for a history of angina or myocardial infarction. Both groups had significant (at least 70% diameter stenosis) coronary artery disease. At catheterization no patient had angina during exercise, but 12 of 15 had ST depression or increased ST depression (group A, 1.9 +/- 1.4 mm; group S, 1.1 +/- 1.2 mm) and 11 had abnormal wall motion. From rest to exercise, patients in group S had increased LV end-diastolic pressure (from 21 +/- 9 to 37 +/- 11 mm Hg, p = 0.009) and volume (from 100 +/- 25 to 107 +/- 26 ml/m2, p = 0.006), with no significant change in LV ejection fraction (from 40 +/- 13 to 42 +/- 12%). In group A LV end-diastolic pressure increased from 19 +/- 4 to 31 +/- 8 mm Hg (p = 0.001), but neither end-diastolic volume nor ejection fraction changed significantly (from 83 +/- 13 to 92 +/- 23 ml/m2 and from 55 +/- 13% to 46 +/- 13%, respectively). Thus, patients with coronary artery disease who survive out-of-hospital VF may have evidence of myocardial ischemia during exercise without pain. Painless ischemia may have a role in out-of-hospital VF.

Adult

Reverse phase passive haemagglutination test for the detection of rinderpest antigen.

Reverse phase passive haemagglutination [RPHA] test was applied for the detection of rinderpest antigen in various organs of rinderpest infected cattle. The results of RPHA were compared with counter immunoelectrophoresis [CIE] and single radial haemolysis [SRH] test. RPHA was as sensitive as CIE and SRH in detecting rinderpest antigen.

Animals

Aortic dissection, a diagnostic dilemma: case report.

A case of type I (type A) aortic dissection proved by postmortem examination could not be fully delineated relative to the type of dissection by dynamic CT as well as three positive contrast aortograms. Small tears in the ascending aorta and their strategic locations can escape even intensive radiologic evaluation. We present a case in which medical therapy was provided and, inappropriately, surgery was not performed.

Aortic Dissection

Application of solid phase aggregation of coated erythrocytes technique for detection of rinderpest antigen.

A solid phase aggregation of coated erythrocytes (SPACE) technique was standardized and used for the detection of rinderpest antigen in 129 samples of 9 visceral organs; from 50 clinical samples such as gum scraping, tongue scraping, faeces, urine, nasal swabs; blood from 18 rinderpest infected cattle and 2 field samples. The comparative sensitivity of SPACE, reverse phase passive haemagglutination and counter-immuno-electrophoresis tests was found to be 86.8, 84.5 and 79.8%, respectively.

Animals

Serodiagnosis of Fasciola gigantica infection in buffaloes.

The agar gel precipitation test (AGPT), counter immunoelectrophoresis (CIEP) and indirect haemagglutination (IHA) were evaluated for the diagnosis of fascioliasis due to Fasciola gigantica in buffaloes. The sensitivity of these tests varied with the intensity of infection; and was greatest when the fluke burden in liver exceeded 100. CIEP detected 76.06% of infected sera and was most sensitive, followed by IHA which detected 68.37% of the infected sera. The AGPT was found to be least sensitive, detecting only 57.4% of the infected sera. Although these tests were limited by the occurrence of false-positive reactions, their use may be an aid for effective diagnosis of fascioliasis in buffaloes.

Animals

Acid secretory capacity and plasma gastrin concentration after administration of omeprazole to normal subjects.

In a randomized double-blind study, two groups of eight healthy volunteers received either placebo or omeprazole 40 mg o.m. for 14 days. Fasting plasma gastrin concentration and peak acid output in response to a maximal intravenous dose of pentagastrin were measured before, during and after the 14 days of treatment. Omeprazole caused a 68% (mean) decrease in the peak acid output when measured 24 hours after the last dose, with a simultaneous increase in the fasting plasma gastrin concentration. When measured 1, 2, 3 and 8 weeks after cessation of treatment, there was no significant difference in the peak acid output between the two groups. The study demonstrates that there is no increase in the acid production capacity after 2 weeks of treatment with omeprazole. Thus it would appear that the rise in the plasma gastrin concentration during short-term treatment with omeprazole does not induce parietal cell hypertrophy or hyperplasia.

Adult

Residual myocardial jeopardy in patients with Q-wave and non-Q-wave infarctions.

The correlation between the presence of areas of jeopardized myocardium and the electrocardiographic patterns of anterior and inferior Q-wave and non-Q-wave infarctions was studied in 486 patients who had had stable symptoms for at least six months after a single myocardial infarction. Myocardial jeopardy was identified on a ventriculogram in the right anterior oblique position if normal or hypokinetic wall motion was seen in all segments distal to a lesion that caused stenosis of greater than 50% and less than 100% in the proximal or mid left anterior descending coronary artery (anterior jeopardy), or in the proximal or mid right coronary artery or proximal circumflex coronary artery in a left dominant circulation (inferior jeopardy). Patients with non-Q-wave anterior infarctions had a significant increase in the frequency of jeopardized myocardium when compared with patients with Q-wave inferior or anterior infarctions. The group with non-Q-wave anterior infarction also had a significantly lower percentage of myocardial segments with absent wall motion in the area of infarction than all other groups. This combination of coronary narrowing with retained wall motion may contribute to the increased frequency of reinfarction seen in some studies of non-Q-wave infarction.

Adrenergic beta-Antagonists

Serodiagnosis of fascioliasis in buffaloes by immunoprecipitation using adult Fasciola gigantica antigens.

Partial purification of a saline extract of adult Fasciola gigantica by chromatography on Sephadex G200 gave four peaks, of which only the first two contained material which gave a precipitation reaction with sera from infected buffaloes. None of these gave false reactions with sera from uninfected animals but even the first and most sensitive fraction only reacted with 57.5 per cent of sera from animals known to be infected with moderate numbers of F gigantica.

Animals