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Biomedical subjects

R Kapoor

Publications and source records attributed to R Kapoor.

At least 253 records · Page 14Linked to original sources
PubMed1982

The effect of hypoxia on the synthesis of collagen and glycosaminoglycans by cultured pig aortic endothelium.

Porcine aortic endothelium cultured at 20% oxygen concentration synthesizes collagen and three of its marker enzymes - proline and lysine hydroxylases and lysine oxidase, the cross-link enzyme. It also synthesizes and secretes hyaluronic acid, dermatan sulphate, possibly heparan sulphate, large amounts of chondroitin 4-sulphate and smaller amounts of chondroitin 6-sulphate. Growth of these cells for 24 h in 0%, or 2% oxygen results in little change in cell numbers or cell protein but a fall in collagen synthesis and in proline and lysine hydroxylases, but a rise in lysine oxidase. There is a considerable increase in synthesis and secretion of all the glycosaminoglycans found. The cell lipids appear qualitatively unchanged. Apart from increased lysosomes seen at 0% oxygen, no ultrastructural changes appear to occur. These findings illustrate the lability of the endothelial response to oxygen lack.

Animals↗
PubMed1981

Bovine aortic chondroitin sulphate- and dermatan sulphate-containing proteoglycans. Isolation, fractionation and chemical characterization.

1. Guanidinium chloride (4M) in the presence of proteinase inhibitors extracted 90% of bovine aorta galactosaminoglycans as proteoglycans that were subsequently purified by ion-exchange and gel chromatography. 2. Fractionation of the calcium salts of the purified proteoglycans with increasing concentration of ethanol yielded fractions PG-25 (28%), PG-35 (45%) and PG-50 (37%). 3. Fraction PG-50 contained proteochondroitin 6-sulphate, whereas fractions PG-25 and PG-35 were proteodermatan sulphates of greatly different carbohydrate composition; the molar proportions of L-iduronate-N-acetylgalactosamine 4-sulphate, D-glucuronate-N-acetyl-galactosamine 4-sulphate and D-glucuronate-N-acetylgalactosamine 6-sulphate were 75: 18 :7 in fraction PG-25 and 14 :46 :40 in fraction PG-35. 4. The presence of alternating or mixed sequences with L-iduronate- and D-glucuronate-containing repeating disaccharides was indicated by the formation of tetrasaccharides after chondroitinase AC digestion (single L-iduronate residues) and by the release of fragments containing four or five consecutive D-glucuronate-N-acetylgalactosamine repeats after periodate oxidation and alkaline elimination. 5. The amino acid compositions of fractions PG-25 and PG-35 were similar and markedly different from that of fraction PG-50, which also contained more side chains.

Amino Acids↗
PubMed1981

Glucose 6-phosphate activation of pyruvate kinase from Mycobacterium smegmatis.

1. Activation of glucose 6-phosphate is one of the unique properties of pyruvate kinase from Mycobacterium smegmatis. 2. Pyruvate kinase, partially purified from ultrasonic extracts of the mycobacteria by (NH4)2SO4 fractionation, exhibited sigmoidal kinetics at various concentrations of phosphoenolpyruvate, with a high degree of co-operativity (Hill coefficient, h = 3.7) and S0.5 value of 1.0 mM. 3. In the presence of glucose 6-phosphate, the degree of co-operativity shown by the phosphoenolpyruvate saturation curve was decreased to h = 2.33 and the S0.5 value was lowered to 0.47 mM. 4. The enzyme was activated by AMP and ribose 5-phosphate also, but the activation constant was lowest with glucose 6-phosphate (0.24 mM). 5. The enzyme was strongly inhibited by ATP at all phosphoenolpyruvate concentrations. The concentrations of ATP required to produce half-maximal inhibition of enzyme activity at non-saturating (0.2 mM) and saturating (2 mM) phosphoenolpyruvate concentrations were 1.1 mM and 3 mM respectively. 6. The inhibition of ATP was partially relieved by glucose 6-phosphate. 7. The enzyme exhibited Michaelis-Menten kinetics with ADP as the variable substrate, with an apparent Km of 0.66 mM. 8. The enzyme required Mg2+ or Mn2+ ions for activity. It was not activated by univalent cations. 9. The kinetic data indicate that under physiological conditions glucose 6-phosphate probably plays a significant role in the regulation of pyruvate kinase activity.

Enzyme Activation↗
PubMed1980

Intrathecal human tetanus immunoglobulin in early tetanus.

97 patients with symptoms of early tetanus at the time of admission to hospital were treated with sedation, antibiotics, and human tetanus immune globulin (TIG). After intrathecal TIG 250 IU 3 patients out of 49 got worse but only 1 died while in a closely similar group of 48 patients in whom TIG was administered intramuscularly in dose of 1000 IU, the clinical features of the disease became severer in 15 (31%) and 10 (21%) died. The intrathecal use of TIG was devoid of side effects.

Adolescent↗
PubMed1977

Effects of electroshock and drugs administered in vivo on protein kinase activity in rat brain.

The effect of electroshock and treatment with reserpine, amphetamine or lithium chloride on protein kinase activity in synaptic membrane fragments prepared from rat brain was investigated. Naive rats subjected to electroshock procedures showed significant increases in both basal and cyclic AMP-stimulated activity irrespective of whether the treatment was sham, acute or chronic. These increases did not occur in animals which had been tamed by daily handling for 15 days prior to treatment, suggesting that the response was induced by the stress of an unfamiliar situation. Administration of lithium chloride and reserpine caused a small but significant increase in the stimulated activity. Doses of d-amphetamine of 5 mg/kg had no effect on either basal or stimulated activity, but higher doses (up to 15 mg/kg) resulted in a pronounced increase in both activities, which may have been related to drug-induced stress.

Animals↗
PubMedDate not supplied

Fetal loss and contraceptive acceptance among the Bhopal gas victims.

The rates of fetal loss and family planning acceptance among Bhopal gas victims from 1984 to 1989 were compared to those of a control group. In all, 136 eligible women in the affected area and 139 women in the control area were interviewed. Care was taken to ensure that these women had conceived at least once during the previous five years. The The fetal loss rate among the gas-affected women was abnormally high (26.3 per cent) compared to that of women in the control area (7.8 per cent). Family planning acceptance in both areas was similar, with most women using permanent methods. In the case of temporary methods, the percentage of use was higher in the gas-affected area.

Abortion, Spontaneous↗
PubMedDate not supplied

Enhanced sensitivity of medullary depressor neurons to N-methyl-D-aspartate-glycine site antagonists in the spontaneously hypertensive rat.

1. The effects of the specific N-methyl-D-aspartate (NMDA)-glycine site antagonist 5-fluoro indole-2-carboxylic acid (FICA) and NMDA, microinjected into the vasodepressor caudal ventrolateral medulla, were compared in spontaneously hypertensive rats (SHR) and in Wistar-Kyoto (WKY) rats. 2. 5-Fluoro indole-2-carboxylic acid elicited a significant pressor response (+20.0 +/- 4.9 mmHg) in SHR, but no change was found in the basal blood pressure of WKY rats. 3. The depressor response due to NMDA microinjection was significantly larger in SHR (-48.0 +/- 4 mmHg) than in WKY rats (-23.0 +/- 1.9 mmHg). 4. Pre-injection of FICA attenuated the depressor effects of NMDA significantly, this blockade being significantly more pronounced in SHR (37.0 +/- 2.7 mmHg) than in WKY rats (12.0 +/- 1.2 mmHg). 5. The enhanced responses to FICA may reflect the lower levels of the endogenous NMDA-glycine antagonist kynurenic acid in SHR compared with WKY rats.

Animals↗
PubMedDate not supplied

Factors that influence patient choice of contact lens or photorefractive keratectomy.

OBJECTIVE: To explore characteristics of patients and factors that influence their decision in selecting photorefractive keratectomy (PRK) and contact lenses. METHODS: A questionnaire was presented to 255 PRK and 240 contact lens patients, covering patient demographics, refraction, reasons for choosing PRK or contact lens, and advice from clinicians or friends/relatives. RESULTS: Mean patient age was 37 years for PRK and 26 years for contact lens (P < .0001). The magnitude of the mean spherical equivalent refraction in the better eye was 4.14 D for PRK and 3.26 D for contact lens. Advertising influenced 36% (n = 92) of PRK compared to 17% (n = 41) of contact lens patients. In the PRK group, 52% (n = 133) opted for PRK based on cost; in the contact lens group the cost of PRK was thought to be high by 68% (n = 163). Eighty-four percent (n = 214) of the PRK group were contact lens wearers; of these, 32% (n = 68) were intolerant to contact lenses and 13% (n = 28) were intolerant to lens care solutions. Fifty-six percent (n = 134) of the contact lens group were concerned about the long-term effects of PRK and 49% (n = 118) were afraid to undergo a surgical procedure. CONCLUSIONS: PRK patients were significantly older but had only marginally higher refractive error than contact lens patients. Many patients appeared to discontinue contact lens use due to tolerance problems.

Adult↗
PubMedDate not supplied

Transabdominal gastroesophageal devascularization without esophageal transection for emergency treatment of variceal hemorrhage.

BACKGROUND: The Suguira procedure is an effective non-shunting operation to treat life-threatening hemorrhage from esophageal or gastric varices. The goal of esophageal transection is interruption of submucosal varices, but this leads to high morbidity and mortality rates from esophageal fistulization. AIM: To evaluate a variant of this procedure in which the esophagus is not transected, but the varices are underrun from outside the lumen. METHODS: During the last four and a half years, we performed this modified gastroesophageal devascularization with or without splenectomy in 18 patients as emergency treatment of bleeding esophageal and gastric varices. The data were analyzed retrospectively. RESULTS: Bleeding was controlled in all patients. Three patients with Child's class C disease undergoing emergency surgery died during the early postoperative period. Rebleeding rate was 17% (3 patients). The overall survival was 72.2% (13 of 18). No patient had encephalopathy over a mean follow up of 30 months. CONCLUSION: Gastroesophageal devascularization with variceal under-running without esophageal transection is an effective and safe alternative to shunt surgery in the emergency situation.

Emergency Treatment↗
PubMedDate not supplied

Stones associated renal pelvic malignancies.

BACKGROUND: The clinico-pathological characteristics of renal pelvic malignancies associated with stones were retrospectively analyzed. AIMS: The main objective was to define the biological behavior and prognostic factors for these malignancies. SETTINGS & DESIGN: The tumors were classified according to the pathological types. The clinical data, imaging features and pathological features were analyzed with relation to prognosis. MATERIAL AND METHODS: Eighteen cases of malignancies associated with stone disease were retrospectively studied. The institute review board permitted the study. RESULTS: High incidence (15/18) of squamous cell carcinoma (SCC) was noted. The prognosis in this group of patients was uniformly poor. The median survival time was 3.6 months in the SCC group, 7.5 months in the Transitional Cell Carcinoma (TCC) group and 24 months in the Adenocarcinoma (AC) group. Infectious and systemic symptoms were noted in the majority of the patients. Preoperative Imaging techniques revealed tumor in only 2 cases. Both underwent radical extirpation and the median survival is 18 months till date. In the other 16 patients, where the initial diagnosis was made only on histological analysis of incomplete nephrectomy specimens, the survival was 3.56 months. All patients had prolonged history of staghorn stone disease with associated non-functioning kidney. We found that the main prognostic factor was the stage of the disease. CONCLUSIONS: Malignancies associated with stone disease have insidious onset of clinical symptoms and need a high degree of suspicion to identify them pre-operatively. The grave prognosis associated with incomplete excision makes it imperative to diagnose them earlier.

Adenocarcinoma↗
PubMedDate not supplied

Correlation of radiological and clinical features of metanephric neoplasms in adults.

The main objective was to determine the clinical and radiological features of metanephric neoplasms. The tumors were diagnosed on histopathological examination. The clinical data and imaging features were retrospectively analyzed. Between 1998 and 2003, 3 patients underwent radical nephrectomy for renal masses turning out as metanephric neoplasms on histopathology. Two of these tumors were metanephric adenoma (MA) and one was metanephric adenofibroma (MAF). Clinical and radiological features were reviewed. All patients were adult females who presented with flank pain. Tumor was detected on screening ultrasound as a hyperechoic lesion. In all cases CT showed a hyper-attenuating exophytic lesion with cystic areas that enhanced with IV contrast. Based on combination of clinical and imaging features it may be possible to prospectively identify metanephric neoplasms and thus avoid unnecessary radical nephrectomy in favor of conservative surgery.

Adenofibroma↗
PubMedDate not supplied

Prognosticfactors in patients with renal cell carcinoma: is TNM (1997) staging relevant in Indian subpopulation?

BACKGROUND: RCC (Renal Cell Carcinoma) is a common genitourinary malignancy, but its behavior has not been studied in the Indian Subpopulation. AIMS: The aim of this study was to assess the validity of 1997 AJCC TNM staging in Indian subpopulation and also to identify independent predictors for survival in patients having RCC. SETTING AND DESIGN: Retrospective uncontrolled analysis of patients with RCC was performed at our centre. MATERIAL AND METHODS: Medical records of patients of undergoing radical nephrectomy at our center between 1994 to August 2003 were identified retrospectively. Medical records of 178 patients were available for analysis. Patient characteristics, preoperative imaging and surgical details were reviewed. Each tumor was staged according to the 1997 AJCC TNM classification. Nuclear grade was assigned according to the Fuhrman's grading system. STATISTICAL METHODS: Statistical analysis was performed using statistical software and descriptive statistics and survival functions were obtained. Univariate and multivariate analysis of factors affecting outcome of the patient were performed. RESULTS: Mean follow up period was 42.3 months (range 3 to 108 months). Stage wise 5-year Cancer specific survival was 87.2% in stage 1 disease, 74.3% in stage 2, 36.4% in stage 3 and 3.1% in stage 4. Univariate analysis revealed that stage, grade and lymph node status were statistically significant (P=0.009, 0.007 and 0.003 respectively). Sub-classifying stage 1 tumors between tumor of less than 4 cm. and more than 4 cm. did not reveal any statistically significant difference in survival (P=0.32). Multivariate analysis model revealed that Fuhrman's grade and lymph node status were statistically significant (P=0.007 and 0.002 respectively). CONCLUSION: This study validates the TNM (1997) staging for RCC as having significant survival impact in the Indian subpopulation. Sub-classifying stage 1 tumors between tumor of less than 4 cm. and more than 4 cm is not of much importance. Nuclear grade and lymph node involvement are important independent predictors of survival. Organ confined tumors with high nuclear grades need to be followed up more rigorously.

Adult↗
PubMedDate not supplied

Papillary cystic neoplasm of the pancreas. Report of a case diagnosed by fine needle aspiration cytology.

Fine needle aspiration (FNA) performed on a young woman who presented with a mass in the left hypochondrium yielded fluid. Smears and Cytospin preparations of the fluid showed good cellularity, consisting of relatively monomorphic cells forming a perivascular papillary pattern. FNA cytology thus suggested a diagnosis of papillary cystic neoplasm of the pancreas. Surgical removal of the pancreatic tumor and detailed histologic study confirmed the cytologic diagnosis.

Adult↗