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Biomedical subjects

S Sharma

Publications and source records attributed to S Sharma.

At least 1,099 records · Page 61Linked to original sources
PubMed1990

Purification and characterization of cellulolytic enzymes produced by Aspergillus nidulans.

Three exo-glucanases, two endo-glucanases and two beta-glucosidases were separated and purified from the culture medium of Aspergillus nidulans. The optimal assay conditions for all forms of cellulase components ranged from pH 5.0 to 6.0 and 50 degrees C and 65 degrees C for exo-glucanases and endo-glucanases but 35 degrees C and 65 degrees C for beta-glucosidases. A close relation of enzyme stability to their optimal pH range was observed. All the cellulase components were stable for 10 min at 40-50 degrees C. Exo-II and Exo-III (Km, 38.46 and 37.71 mg/ml) had greater affinity for the substrate than Exo-I (Km, 50.00 mg/ml). The Km values of Endo-I and Endo-II (5.0 and 4.0 mg/ml) and their maximum reaction velocities (Vmax, 12.0 and 10.0 IU/mg protein) were comparable. beta-Glucosidases exhibited Km values of 0.24 and 0.12 mmol and Vmax values of 8.00 and 0.67 IU/mg protein. The molecular weights recorded for various enzyme forms were: Exo-I, 29,000; Exo-II, 72,500; Exo-III, 138,000; Endo-I, 25,000; Endo-II, 32,500; beta-Gluco-I, 14,000 and beta-Gluco-II, 26,000. Exo- and endo-glucanases were found to require some metal ions as co-factors for their catalytic activities whereas beta-glucosidases did not. Hg2+ inhibited the activity of all the cellulase components. The saccharification studies demonstrated a high degree of synergism among all the three cellulase components for hydrolysis of dewaxed cotton.

Aspergillus nidulans↗
PubMed1990

Adult embryonal rhabdomyosarcoma of the vagina complicating pregnancy: a case report and review of the literature.

Embryonal rhabdomyosarcoma of the vagina in adults per se is uncommon and pregnancy complicated by such tumors is extremely rare. We wish to report one case of vaginal embryonal rhabdomyosarcoma, diagnosed at the age of 23 years who was carrying at the time of initial presentation. The problem of management of rhabdomyosarcoma in adults, particularly when they are associated with pregnancy is discussed. We advocate the use of multiagent chemotherapy and pelvic radiotherapy in its overall management.

Adult↗
PubMed1990

Virological investigations of acute encephalopathy in India.

A total of 740 consecutive children aged between 6 months and 12 years who presented with acute encephalopathic illnesses during a three year period were assessed both clinically and by laboratory investigations. Cerebrospinal fluid was examined for the presence of cells or other abnormal substances, and any organisms were cultured. Blood examination included white cell count and estimations of haemoglobin, urea, glucose, and electrolyte concentrations and serum alanine aminotransferase and aspartate aminotransferase. A firm diagnosis was established in 278 patients (38%). Pyogenic meningitis (n = 134), measles encephalopathy (n = 38), and electrolyte imbalance (n = 23) were important causes in this group, cerebral malaria (n = 4) was uncommon and there were no cases of Reye's syndrome. The diagnoses of the remaining 462 were combined under the heading 'acute unexplained encephalopathy'. Altogether 394 of the 462 patients underwent virological investigations for arboviruses and 92 (23%) had one or more indicators of Japanese encephalitis. No other arboviruses could be isolated. Throat swabs from 187 patients with acute unexplained encephalopathy were studied on monkey kidney tissue cell lines of which 14 were positive (8%). These were identified as adenovirus, parainfluenza, influenza, poliomyelitis, Coxsackie, and echovirus; in two cases the virus was untypable. Japanese encephalitis is an important cause of acute childhood encephalopathy in this region. Clinical features of the illness may be mimicked by several disorders which require specific treatment. Thirty four of the 92 died (37%).

Acute Disease↗
PubMed1990

Comparative studies on the effect of vitamin A, B1 and B6 deficiency on oxalate metabolism in male rats.

The study was conducted to investigate the effect of vitamin A, B1 and B6 deficiency on oxalate metabolism in rats. A significant hyperoxaluria was the common observation in all the three vitamin deficiencies (vitamin B6 greater than vitamin A greater than vitamin B1). The activities of hepatic glycolate oxidase and glycolate dehydrogenase were markedly enhanced in vitamin-A- and vitamin-B6-deficient rats. However, lactate dehydrogenase levels remained unaltered in these deficiencies as compared to their respective pair-fed controls. Vitamin B1 deficiency of 4 weeks' duration could augment the activity of glycolate oxidase only, with no alterations in the glycolate dehydrogenase and lactate dehydrogenase levels. Intestinal oxalate uptake studies revealed increased bio-availability of oxalate from the gut in vitamin-A- and vitamin-B6-deficient rats. Thus, the results suggest the relative contribution of both exogenous as well as endogenous oxalate in the process of calculogenesis under various nutritional stress conditions in rat.

Animals↗
PubMed1990

Initial experience with percutaneous transluminal angioplasty in the management of Takayasu's arteritis.

We have performed percutaneous transluminal angioplasty (PTA) for 15 arterial stenoses in 11 patients with Takayasu's arteritis. The lesions included tight, proximally located renal artery stenosis (12 stenoses; nine patients), localized abdominal aortic stenosis (two patients) and occluded left common iliac artery (one patient). Clinically successful dilatation was achieved in seven patients (10 stenoses) with renal artery stenosis, in both the patients with abdominal aortic stenosis and in the only patient with an occluded left common iliac artery. No complications related to the procedure were encountered. The follow-up period (n = 7) ranged between 1 and 16 months, mean follow-up period after renal angioplasty was 5 months and after abdominal aortic angioplasty was 12.5 months. Initial success has been maintained in both the patients with abdominal aortic stenoses and in four out of five patients with renal artery stenosis. Percutaneous transluminal angioplasty offers an attractive alternative for the management of stenosing lesions in Takayasu's arteritis with good short term results.

Adolescent↗
PubMed1990

Benign nerve sheath tumors: a light microscopic, electron microscopic and immunohistochemical study of 102 cases.

One hundred and two cases of benign nerve sheath tumors (NSTs) were studied with a combined approach using routine light microscopy (LM), immunohistochemistry (IH) for myelin basic protein (MBP) and S-100 protein as well as transmission electron microscopy (TEM) with the aim of obtaining greater insight into the true nature of these neoplasms, and also to establish the importance of IH and TEM in their diagnosis. Myelin basic protein was not identified in any of these tumors, whereas S-100 protein was positive to a variable degree in both schwannomas and neurofibromas. TEM revealed that Schwann cells predominated in tumors which were strongly positive for S-100 protein and appeared as schwannomas by LM. However, neurofibromas showing a variable patchy positivity for S-100 were composed of an admixture of Schwann cells, fibroblast-like cells and intermediate cells considered to be modified Schwann cells. Perineurial cells in typical form were not seen. It is concluded that all NSTs are basically of Schwann cell origin and that the intermediate cells and fibroblast-like cells are variants of Schwann cells. The different morphological appearances and biological behaviour of schwannomas and neurofibromas may be related to some other factors like micro-environment or genetic predisposition. Further, both IH, especially for S-100 protein, and TEM play an important role in establishing their diagnosis.

Cranial Nerve Neoplasms↗
PubMed1990

Effect of vitamin A deficiency on oxalate uptake by rat intestinal brush border membrane vesicles (BBMV) and its contribution towards urolithiasis.

The intestinal uptake of [14C]oxalate, [14C]glyoxylate, and [14C]glycolate are studied in brush border membrane vesicles (BBMV) isolated from vitamin A-deficient and pair-fed control rats. The data obtained indicate that oxalate and its precursors are transported across the BBMV by passive diffusion. The intestinal uptake of glyoxylate and glycolate remains unaltered in vitamin A deficiency, while uptake rate of oxalate was significantly increased (p less than 0.01) in vitamin A-deficient rats as compared to pair-fed controls. In conclusion, the results indicate that vitamin A deficiency leads to hyperabsorption of oxalate through the gut.

Animals↗
PubMed1990

Mechanism of protection provided by active immunization with porins in mice challenged with Salmonella typhi.

Oxygen free radical (OFR) generation capacity of peritoneal macrophages was studied by chemiluminescent technique. Chemiluminescent (CL) response of macrophages from control, infected and immunized-infected mice was observed using non specific (Latex) and specific (S. typhi, cells and porins) stimulants at different time intervals. CL response was found to be significantly higher in immunized-infected group throughout the study period using all the three stimulants as compared to that in the infected as well as uninfected control mice. The mode of action of porin vaccine in increasing capacity of generating OFR is probably through increased expression of porin (protein) as well as carbohydrate receptors on the macrophage surface which leads to the stimulation of the whole caseade of respiratory burst or through the increase in the respiratory burst enzyme activities linked with each receptor or both.

Animals↗
PubMed1990

Localization of carcinoembryonic antigen in uterine cervical neoplasia.

Tissues for 74 uterine cervical lesions including 64 invasive squamous cell carcinomas, 4 adenocarcinomas and 6 cervical intraepithelial neoplasia (CIN) were studied by peroxidase-antiperoxidase (PAP) method for presence of carcinoembryonic antigen (CEA). CEA was absent in normal squamous and endocervical epithelium. The antigen was demonstrated in all the cases of CIN (100%) and in 48 invasive carcinomas (70.6%). A heterogeneous pattern of staining was noted in different cases and also within a tumour. None of the 6 endometrial carcinomas showed CEA reactivity while all sections from endocervical carcinomas were positive for CEA. Carcinoembryonic antigen may be a useful tumour marker in the diagnosis of cervical neoplasia and helpful in differentiating endocervical carcinoma from endometrial carcinoma.

Adenocarcinoma↗
PubMed1990

Gemfibrozil in familial and type V hyperlipidaemias. Report of 3 cases.

Gemfibrozil, a lipid lowering agent, was administered to two patients with familial hyperlipidaemia and one patient with insulin dependent diabetes mellitus. It was partially effective in familial hyperlipidaemia. It dramatically reduced triglyceride and cholesterol levels in the patient with Type V hyperlipidaemia and insulin dependent diabetes mellitus. Patients with familial and Type V hyperlipidaemias should be given a trial of gemfibrozil therapy.

Adult↗
PubMed1990

Occult carcinoma esophagus metastatic to spine producing paraplegia--a case report and review of literature.

An extremely rare case of asymptomatic squamous cell carcinoma of the esophagus metastatic to the spine leading to paraplegia is reported. The rarity of such an event signifies the relationship between hypercalcaemia and carcinoma of the esophagus. Its occurrence as a second silent primary neoplasm and its association with a negative esophagogram is highlighted.

Carcinoma, Squamous Cell↗
PubMed1990

Rapid diagnosis of Japanese encephalitis by immunofluorescent examination of cerebrospinal fluid.

An indirect immunofluorescent technique for rapid diagnosis of patients of Japanese encephalitis (JE) was developed by demonstrating the viral antigen in CSF cells. The CSF samples of 31 consecutive patients admitted with acute viral encephalitis during 1987 were studied. In 15 patients the diagnosis of JE virus infection was made on the same day. Classical techniques for virus detection and antibody serology were also conducted in these patients. The indirect immunofluorescence for JE virus antigen detection in CSF cells proved to be a rapid and simple procedure for making a quick diagnosis of infection.

Acute Disease↗
PubMed1990

Bioecological factors & rotavirus diarrhoea.

Rotavirus was detected (using Rotalex) in 11.72 per cent (120 of 1024) children below 3 yr age with diarrhoea. None of the 25 healthy control children excreted rotavirus in their faeces. Group specific ELISA for 89 Rotalex positive samples revealed 30 subgroup I and 43 subgroup II whereas 10 were untypable. Rotavirus infection ranged from 2.8 to 22.20 per cent in different months. There was no correlation with mean minimum and maximum temperatures. However, the incidence showed a negative correlation (r = -0.645) with relative humidity. Children between the age of 10 to 12 months had the maximum incidence of rotavirus infection. Male patients were found to be more susceptible to infection than females (3.3:1).

Child, Preschool↗
PubMed1990

Clinical features & prognostic indicators of Japanese encephalitis in children in Lucknow (India).

This communication reports the clinical features of 92 children with Japanese encephalitis diagnosed on the basis of viral isolation from brain or cerebrospinal fluid and/or a 4-fold or higher rise in antibody titre in paired sera by haemagglutination inhibition (HI) test, followed by detection of specific IgM HI antibody. More than a third of the patients (38%) were from urban areas. A high incidence of fever (94.5%), coma (100%) and convulsions (84.7%) was seen. Focal neurological deficit was found in 29.3 per cent of patients and pleocytosis in the cerebrospinal fluid in 32.3 per cent. An extrapyramidal syndrome developed in 21.3 per cent patients during the convalescent stage. Thirty four (36.9%) patients died while in hospital. Mortality was significantly related to a short prodromal stage, deep coma, abnormalities in tone and breathing and decerebrate posturing. Japanese encephalitis represents a severe disease in children with a high early mortality.

Child↗