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Biomedical subjects

B K Sharma

Publications and source records attributed to B K Sharma.

At least 19 recordsLinked to original sources
PubMed1992

Oxygen free radicals in essential hypertension.

Membrane abnormalities in essential hypertensives (EH) are well known. The respiratory burst enzyme, NADPH oxidase is located in the cell membrane of the neutrophil (PMNLs) and its activity is important in generation of oxygen derived free radical (OFR). Recently OFR have been implicated in vascular changes in variety of conditions. An attempt was made to delineate the status of OFR and antioxidants in EH. Ten, age and sex-matched, healthy controls (GpI) and 26 untreated EH (Gp IIA mild-8, Gp IIB Moderate-8, Gp IIC Severe-10) were studied. After clinical examination and basic laboratory evaluation of subjects, neutrophils isolated from their blood were studied. Chemiluminescence (CL) emitted by PMNLs after stimulation was measured (counts/min) in a luminometer and was taken as measure of OFR production and thereby of NADPH oxidase activity. The levels of antioxidants, superoxide dismutase (SOD) and reduced glutathione (GSH), were also estimated. Chemiluminescence was increased significantly (p less than 0.01) in Gp IIC (243.04 +/- 24.9 x 10(3) counts per minute) as compared to Gp IIA (2.80 +/- 1.87), Gp IIB (34.54 +/- 30.24) and Gp I (0.52 +/- 0.15) and SOD was reduced significantly (p less than 0.05) in all EH (Gp IIA 3.9 +/- 0.3 units per mg protein, Gp IIB 3.5 +/- 0.3 and Gp IIC 3.12 +/- 0.3) as compared to controls (4.1 +/- 0.2). Similarly GSH was reduced (p less than 0.05) in EH (Gp IIA 11.2 +/- 1.7 mg per gm protein, Gp IIB 8.5 +/- 1.1 and Gp IIC 6.6 +/- 0.3) as compared to Gp I (13.5 +/- 2.5).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Takayasu arteritis in India.

Takayasu arteritis is the commonest cause of renovascular hypertension in India. The clinical and radiological features, complications and course of 83 patients (51 females, 32 males) seen during the period from 1972-1990 are described in this study. The age of the patients ranged from 5 to 53 years with the mean +/- SD of 26.9 +/- 9.7. Hypertension (n = 50) and the related symptom of headache (n = 40), dyspnea (n = 24), and giddiness (n = 20) were common at presentation. Twelve patients were in congestive cardiac failure. The symptoms of activity with fever and arthralgia were present in only 16% contrary to reports from Japan and Mexico. Abnormal arterial pulses and bruit over abdominal (37%) or extra abdominal great arteries (25%) were useful clinical clues to suspect Takayasu arteritis. Rapid sequence intravenous urography was a sensitive screening procedure and predicted correctly the presence of renovascular disease in 80% of the patients. The diagnosis was confirmed on aortography in 72. In the rest, the clinical features and autopsy findings confirmed the same. The four patterns of the disease based on the anatomical extent of involvement were recognised. These were: type I (n = 8) with involvement of aortic arch and its branches, type II (n = 25) descending thoracic and abdominal aorta type III (n = 46) combination of I and II and type IV (n = 4) pulmonary artery in addition to any of the above.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

Immunopathogenesis of Takayasu arteritis.

Takayasu arteritis is a common cause of renovascular hypertension in India. Sensitization to infective agents, particularly mycobacterium tuberculosis or autoimmune disturbances have been incriminated in its pathogenesis. Twenty patients of Takayasu arteritis along with groups of normal individuals, patients of essential hypertension, autoimmune disorders, tuberculosis, and healthy tuberculin reactors were studied. Besides detailed immunological profiles including LE cell phenomenon, serum complement C3 levels, antibodies to single (SS) and double stranded (DS) DNA, rheumatoid factor, lymphocyte subsets, blast transformation to antigens including, phytohemagglutinin, PPD, pokeweed, and purified human aortal antigen (PHAA) were examined. Soluble protein from human aorta was fractionated into 9 peaks by DEASE-52 and Sephadex G-75 chromatography, and 25 micrograms of major protein fraction-II was used for blast transformation study. Blast transformation by PHAA was higher in Takayasu arteritis as compared to all other groups (P < 0.05). Blast transformation to PPD showed wide variation in all the groups, and was significantly higher only in tuberculin reactors as compared to controls. These observations support aortal sensitization to PHAA playing a role in pathogenesis of Takayasu arteritis and do not relate tuberculosis to Takayasu arteritis, at least immunologically. In addition, the ratio of CD-4 positive to CD-8 positive lymphocytes changing in favor of the former and the concomitant increase in B lymphocytes favor the presence of autoimmune disturbances in Takayasu arteritis.

Adolescent↗
PubMed1992

Coarctation repair in neonates with subclavian-sparing advancement flap.

A modification of the technique of using the subclavian-sparing advancement flap for severe coarctation of the aorta was successfully used in 7 neonates ranging in age from 3 to 30 days (mean age, 12 days). Four of the 7 patients had associated cardiac defects with congestive heart failure. The procedure was performed through a left thoracotomy incision, and the coarctation repair was performed by advancing the origin of the left subclavian artery as a flap while preserving flow to the left arm. No deaths occurred, and there was patency of the repair in all patients at follow-up ranging from 1 1/2 to 2 1/4 years (mean, 2 years). In 7 of the 8 patients there was no clinically significant gradient either by examination or Doppler echocardiography at follow-up. One patient underwent balloon angioplasty at the time of catheterization to evaluate other cardiac defects 1 year postoperatively, at which time he was noted to have a peak systolic gradient of 30 mm Hg across the repair site. The technique of subclavian-sparing advancement is a reasonable addition to the surgical armamentarium for coarctation repair in neonates. It provides the advantages of subclavian flap aortoplasty without sacrificing the blood supply to the left arm. Because of the unique anatomic variations associated with coarctation of the aorta, we suggest that the choice of repair be individualized for patients with this condition.

Aortic Coarctation↗
PubMed1992

Ca2+ transport in unstimulated platelets of essential hypertensives and their blood relatives.

OBJECTIVE: Intracellular free Ca2+ concentration has been shown to be elevated in platelets from essential hypertensive patients. This study was designed to characterize Ca2+ homeostasis in platelets of essential hypertensives. DESIGN: A double-blind study was carried out. Untreated and treated (propranolol therapy) essential hypertensives were studied in comparison with normotensive control subjects. First-degree blood relatives of essential hypertensives were also studied. The various procedures used in the study were already standardized and well-established methods. METHOD: For Ca2+ uptake and efflux studies, 45Ca was used. For intracellular free Ca2+ concentration studies the fluorescent Ca2+ chelator dye fura-2/acetoxymethyl ester (fura-2/AM) was used. RESULTS: The uptake of 45Ca by unstimulated platelets of untreated essential hypertensives and their relatives was significantly higher than for controls. However, essential hypertensives treated with a beta-blocker drug showed no significant difference in Ca2+ uptake compared with controls. A significantly decreased Ca2+ efflux was observed in essential hypertensives (both untreated and treated) compared with controls. Relatives also showed a depressed Ca2+ efflux compared with controls. CONCLUSIONS: It appears that the elevated intracellular free Ca2+ concentration levels in platelets (also observed by us) may be due to both an enhanced uptake into, and decreased efflux of Ca2+ from, the cell. Beta-blocker therapy may help to normalize the elevated intracellular free Ca2+ concentration levels observed in essential hypertensives. Relatives exhibit a state predisposed towards the development of hypertension.

Adolescent↗
PubMed1992

Fluorescein angiography in systemic hypertension.

This study evaluates the role of fluorescein angiography (FA) in detecting changes in the retinal and choroidal capillary bed in hypertension and defines its advantages over direct ophthalmoscopy. 37 patients with varying degree of severity of hypertension were studied. Direct ophthalmoscopy and FA was done in all cases. No significant difference was found in documenting vessel calibre and arteriovenous crossing changes with either of the methods. Hard exudates were not visualized on FA. Capillary bed and choroidal abnormalities could be better studied on FA which can be employed in selected patients of hypertension but its use is not advocated as a routine in all hypertensives.

Adult↗
PubMed1992

Prolonged undiagnosed fever in northern India.

A prospective study for five years along with a retrospective analysis of all patients admitted over 10 years with the diagnosis of prolonged undiagnosed fever was carried out in a referral hospital of North India to determine the specific disorders responsible for it. One hundred and fifty patients (80 prospective and 70 retrospective) were included in the study. Infections, especially tuberculosis, was the most dominant cause (50%), followed by lymphoreticular and haematological disorders (21.32%), collagen vascular disorders and neoplasms (8.67%) each. Miscellaneous causes were responsible in 6.67% and in 4.67% the cause of fever remained undiagnosed.

Academies and Institutes↗
PubMed1992

Chemiluminescence response of phagocytes in E. coli induced experimental ascending pyelonephritis.

The mechanism of tissue injury at the cellular level by following the chemiluminescence response of various phagocytes in E. coli induced experimental pyelonephritis in mice was investigated. There was a marked increase in the capacity of various phagocytic cells viz; renal neutrophils and macrophages peritoneal macrophages, blood monocytes and neutrophils to produce reactive oxygens species through the respiratory burst activity as monitored by the chemiluminescence response. The chemiluminescence response was observed to be increased significantly (p less than 0.001) with increasing days post infection in all phagocytic cells. However, the quantity of total reactive oxygen species produced per million cells was much more in the renal and peritoneal macrophages as compared to blood monocytes and neutrophils. The peak chemiluminescence response time was observed to be decreased from 4 to 2 minutes with the progression of the diseases. The implications of these findings have been discussed.

Animals↗
PubMed1992

Extrathoracic Castleman's disease.

Castleman's disease is an uncommon clinical entity. We report two cases of this disease with a brief review of literature. Both of them had extrathoracic disease which is relatively infrequent. One of them presented with localized hyaline vascular type of the disease and the other with the multicentric plasmacytic variety. The patient with the latter form of Castleman's disease had sclerodactyly, which has not been reported earlier in association with this disease.

Adolescent↗
PubMed1992

Visceral larva migrans in an adult.

Visceral larva migrans is rare in adults. An adult male in whom the diagnosis was made by suggestive clinical features and muscle biopsy and who responded to thiabendazole is described.

Adult↗
PubMed1991

Blood pressure in schoolchildren in northwest India.

Blood pressure was determined among 2,453 schoolchildren aged between 7 and 16 years in the northwest Indian town of Chandigarh to establish the norms. The percentiles were calculated for each age group in both sexes. Both systolic and diastolic blood pressure had a positive correlation with age, weight, height, and body surface area (r = 0.112-0.178, p less than 0.01). There was no difference in the systolic and diastolic pressures of boys compared with girls of corresponding age. The upper limits of normal (90th percentile) systolic/diastolic pressure were 113/74, 119/76, and 126/79 in children aged 7-9 years, children aged 10-12 years, and adolescents aged 13-16 years, respectively. The lower limits of hypertension (95th percentile) for systolic/diastolic pressure were 119/80, 124/81, and 132/82 in each of these groups, respectively. The 99th percentile values indicative of severe hypertension for systolic/diastolic pressure in these groups were 128/88, 135/88, and 149/89, respectively. The 90th percentile of height and weight shown in the percentile table should be taken into consideration whenever blood pressure exceeds the 90th percentile for age and sex while planning the management of an individual.

Adolescent↗
PubMed1991

Supravalvar aortic stenosis: a 29-year review of surgical experience.

Between February 1960 and August 1989, 73 consecutive patients underwent surgical correction for supravalvar aortic stenosis (SVAS) at the Texas Heart Institute. There were 43 male (59%) and 30 female patients (41%) ranging in age from 5 days to 27 years (mean age, 12 years). Preoperatively, 8 patients were in New York Heart Association functional class I, 43 in class II, 18 in class III, and 4 in class IV. Of the 73 patients, 62 had localized SVAS and 11 (15%), diffuse SVAS. For all procedures, patients were placed on cardiopulmonary bypass. Those with localized SVAS were successfully treated with patch aortoplasty, whereas those with diffuse SVAS required either an apicoaortic conduit or extensive end-arterectomy with extended patch aortoplasty. There were eight early deaths (less than or equal to 30 days postoperatively) (11%) and four late deaths (greater than 30 days postoperatively) (6%) in a follow-up period ranging from 2 months to 28 years. Sixteen patients (25%) underwent one or more additional operations in the follow-up period. Postoperatively, there were 44 patients in New York Heart Association functional class I and 17 in class II. Preoperative functional class III and class IV (p less than 0.0005), diffuse SVAS (p = 0.05), and the presence of associated congenital defects (p less than 0.01) were important determinants of death.

Adolescent↗
PubMed1991

Reduced serum concentrations of insulin-like growth factor-I (IGF-I) in protein-restricted growing rats are accompanied by reduced IGF-I mRNA levels in liver and skeletal muscle.

The serum concentration of insulin-like growth factor-I (IGF-I) is reduced in growing rats fed a low-protein diet, and this decrease is age-dependent, being more pronounced in younger animals. To determine whether this decrease in serum IGF-I is related to a decrease in IGF-I mRNA, growing female rats were given free access to either a 15% protein-sufficient or a 5% protein-deficient diet for 1 week. Protein restriction in 4-week-old rats decreased body weight gain by 44% (P less than 0.001 compared with 4-week controls), serum IGF-I concentration by 67% (P less than 0.001) and liver IGF-I mRNA abundance by 51% (P less than 0.001). During week 6, protein restriction for 1 week resulted in a 20% increase in food intake with no change in weight gain, a 38% reduction in serum IGF-I (P less than 0.001 compared with 6-week controls) and a 39% decrease in liver IGF-I mRNA (P less than 0.001). The serum IGF-I concentration was highly correlated (r = 0.80; P less than 0.001) with the hepatic IGF-I mRNA concentration. Skeletal muscle IGF-I mRNA abundance was also decreased significantly by protein restriction (37% at week 4, P less than 0.001, and 24% at week 6, P less than 0.01) and was closely correlated (r = 0.71; P less than 0.001) with body weight gain. Liver GH-binding protein and GH receptor mRNA abundance were reduced by 1 week of protein deprivation at week 6 but not at week 4.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Effect of dietary rumen-protected choline in lactating dairy cows.

Two experiments were conducted to test the effects of graded amounts of rumen-protected choline on milk yield and composition in lactating dairy cows fed 40% corn silage and 60% concentrate diets (DM basis). In Experiment 1, 48 Holstein cows were fed 0, .078, .156, and .234% rumen-protected choline (choline chloride basis) from wk 5 to 21 postpartum. Increasing choline had no effect on DMI and tended to increase milk yield only from 1 to 2.2 kg/d. Milk fat percentage was reduced in the .078% choline treatment and increased to control levels thereafter with .156 and .234% choline. In Experiment 2, 16 Holstein cows in midlactation were assigned randomly to either 13.0 or 16.5% dietary CP (DM basis). Within CP concentration, cows were fed 0, .08, .16, and .24% rumen-protected choline in a replicated 4 x 4 Latin square design. Dietary protein had no effect on milk yield, although milk protein percentage and yield were increased .25 percentage units and 63 g/d, respectively, by increased dietary CP. Increasing dietary choline to .24% linearly increased milk yield 2.6 kg/d, although it had no consistent effects on milk fat or protein percentage. There was only a slight tendency for greater responses in milk yield to dietary choline with lower dietary CP. Data from these experiments confirm earlier results with postruminal choline infusions, suggesting that choline may be a limiting nutrient for milk production.

Animal Feed↗
PubMed1991

Identification of human papillomaviruses in paraffin embedded cervical pathological tissues from Indian women by polymerase chain reaction.

The polymerase chain reaction (PCR) technology was used to identify human papillomaviruses (HPV) in 52 paraffin embedded cervical tissues from Indian women with chronic cervicitis, different grades of cervical dysplasia and invasive cervical carcinoma. The tissues were screened for amplification of the cellular beta-globin gene as well as of HPVs. Sets of primers designed to amplify a portion of the E6 gene of HPV 6, 11, 16, 18, 31, 33 and 35 were employed. HPV 6, 16 and 31 were identified in 58% of 33 beta-globin positive tissues as compared to 16% of 19 beta-globin negative tissues. HPV 11, 18, 33 and 35 were not identified in any of the specimens. Double infection of HPV 16 and 31 was observed in one case of carcinoma in situ and one case of invasive carcinoma. HPV-16 was the predominant virus in HPV positive cases of higher grades of cervical dysplasia (severe dysplasia and carcinoma in situ) and cervical cancer.

Carcinoma↗
PubMed1991

Variability in beta-globin and HPV DNA amplification by PCR from fixed tissues.

Paraffin-embedded tissues from a variety of sources and treated with different fixatives were tested for beta-globin and HPV amplification by polymerase chain reaction (PCR). In tests of tissues collected in the previous 2 to 3 yr, excellent rates (87% to 93%) for beta-globin amplification were obtained for specimens fixed in buffered formalin, Bouin's, and Hartmann's solutions. In contrast, the rate of beta-globin amplification was low for tissues fixed in Hollande's solution (7%) and in Hartmann's solution with eosin (33%). The results of beta-globin amplification from archival tissues stored for variable time periods showed no decrease in the amplification rate with longer periods of storage. Human papillomaviruses (HPVs) were identified in 17% of globin negative and in 43% of globin positive tissues. HPV-16 amplification was more efficient when the targeted DNA sequence was small. Variability in amplification depends not only on the type of fixative used, but also on other ill-defined factors. Therefore, conditions for optimal amplification should be determined before undertaking studies of archival material.

Blotting, Southern↗