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Biomedical subjects

S K Jain

Publications and source records attributed to S K Jain.

At least 55 records · Page 3Linked to original sources
PubMed2002

Racial differences in the frequency of symptoms and complications of gastro-oesophageal reflux disease.

BACKGROUND: A number of reports have suggested that there are substantial racial differences in the frequency of gastro-oesophageal reflux disease and its complications, but few studies have compared directly the frequency of this disorder amongst different racial groups. AIM: To explore the racial differences in the frequency of gastro-oesophageal reflux disease and its complications. METHODS: We reviewed endoscopy reports and medical records for data on race and complications of gastro-oesophageal reflux disease in 2,477 consecutive patients who had endoscopic examinations at the general endoscopy unit of an academic hospital. In addition, we prospectively interviewed 129 out-patients attending general medical clinics in the hospital and in an Asian community health centre in Boston to obtain data on race and gastro-oesophageal reflux disease symptoms. RESULTS: One or more gastro-oesophageal reflux disease complications (peptic oesophageal ulcer, stricture or Barrett's oesophagus) were observed in 267 of 2,174 white patients (12.3%), seven of 249 black patients (2.8%), one of 21 West Asian patients (4.8%) and none of 33 East Asian patients seen at the general endoscopy unit (P < 0.001); 34.6% of whites, 46.1% of blacks and 2.6% of East Asian patients interviewed claimed that they had heartburn (P < 0.01), but the term 'heartburn' was understood by only 34.6%, 53.8% and 13.2% of whites, blacks and East Asians, respectively (P < 0.01). CONCLUSIONS: Asian patients in Boston infrequently complain of heartburn, whereas heartburn is commonly reported by both white and black patients. Many patients do not understand the meaning of the term heartburn, however, and so physicians should be cautious when using the term during patient interviews. Complicated gastro-oesophageal reflux disease appears to be predominantly a disorder of whites.

Adult↗
PubMed2002

Fungistatic activity of some perfumes against otomycotic pathogens.

The sporostatic effect of five otomycotic pathogens, i.e. Aspergillus niger, A. flavus, Absidia corymbifera, Penicillium nigricans and Candida albicans to nine different perfumes was determined on the basis of their spore germination. These organisms were isolated from patients suffering from fungal infection of the external auditory canal. Volatile vapours emanating from musk, phulwari, jasmine, nagchampa and bela caused approximately 100% inhibition in spore germination of all the test fungi. Volatiles emanating from chandan, khas and hina showed no inhibition for the test pathogens, displaying their resistant character to these perfumes.

Antifungal Agents↗
PubMed2002

Unique oligomeric intermediates of bovine liver catalase.

Catalases, although synthesized from single genes and built up from only one type of subunit, exist in heterogeneous form with respect to their conformations and association states in biological systems. This heterogeneity is not of genetic origin, but rather reflects the instability of this oligomeric heme enzyme. To understand better the factors that stabilize the various association states of catalase, we performed studies on the multimeric intermediates that are stabilized during guanidine-hydrochloride- and urea-induced unfolding of bovine liver catalase (BLC). For the first time, we have observed an enzymatically active, folded dimer of native BLC. This dimer has slightly higher enzymatic activity and altered structural properties compared to the native tetramer. Comparative studies of the effect of NaCl, GdmCl, and urea on BLC show that cation binding to negatively charged groups present in amino acid side chains of the enzyme leads to stabilization of an enzymatically active, folded dimer of BLC. Besides the folded dimer, an enzymatically active expanded tetramer and a partially unfolded, enzymatically inactive dimer of BLC were also observed. A complete recovery of native enzyme was observed on refolding of expanded tetramers and folded dimers; however, a very low recovery (maximum of approximately 5%) of native enzyme was observed on refolding of partially unfolded dimers and fully unfolded monomers.

Anilino Naphthalenesulfonates↗
PubMed2002

Esophageal tuberculosis: is it so rare? Report of 12 cases and review of the literature.

OBJECTIVE: Mycobacterial involvement of the esophagus is rare in both immunocompetent and immunocompromised hosts with advanced pulmonary tuberculosis, even in countries with high prevalence rates like India. Most of the reported cases of esophageal tuberculosis (ET) are secondary to tuberculosis elsewhere in the body, most commonly pulmonary tuberculosis. Very few cases of isolated or primary ET have been reported, and most of them have been from developing countries. The upsurge in reported cases of tuberculosis linked to the AIDS epidemic has increased the incidence of this infection in developed countries also. Our aim is to study tuberculosis as an etiological factor in the causation of dysphagia, the role of cytology and histopathology in establishing its diagnosis, and the outcome of antitubercular treatment in these patients. METHODS: A hospital-based, retrospective study was performed. We reviewed records of all of the patients who underwent upper GI endoscopic examination for complaints of persistent dysphagia (>6 wk) in a tertiary care hospital in India between 1995 and 1999. Patients with abnormal endoscopic findings were subjected to endoscopic fine needle aspiration/brush cytology and biopsies. Those with pathological findings suggestive of tuberculosis were treated with antitubercular therapy. RESULTS: Tubercular involvement of the esophagus, confirmed by pathological examination, was found in 12 patients. They constituted 0.5% of all patients with persistent dysphagia, and 1.3% of all patients having abnormal esophagoscopic findings. Cytological examination provided a very useful diagnostic parameter in detection of these cases. Patients diagnosed as having ET responded well to antitubercular therapy. CONCLUSIONS: Tuberculosis as a causative factor for dysphagia should be considered in developing countries with high incidences of tuberculosis and in immunocompromised hosts. Detection of these cases by careful examination of cytological smears and biopsies and treatment with standard antitubercular therapy appear effective.

Adolescent↗
PubMed2002

Asymptomatic giant pheochromocytoma.

An interesting case of pheochromocytoma is being presented which remained asymptomatic despite attaining a size of 16 x 11 cm. On intensive investigations, it was found to be a dopamine secreting tumour with certain features in favour of malignancy. The case was successfully operated and advised regular follow up.

Adrenal Gland Neoplasms↗
PubMed2002

Laser palliation of esophageal carcinoma.

OBJECTIVE: Forty-five cases of advanced esophageal carcinoma were treated with Nd:YAG laser, to relieve dysphagia. METHODS: There were 36 males (80%) and nine female (20%) patients. The mean age of the patients was 55.87 years. Thirty-nine patients (86.6%) were found to have squamous cell carcinoma. Middle third growths were found to be most common (66.6%), followed by lower third (20%) and upper third (13.3%) tumours. The mean dysphagia grade at presentation was 3.33 with all 45 patients (100%) having dysphagia. RESULTS: After three months of treatment, the mean dysphagia grade improved to 1.73 with 39 patients being able to eat at least soft or solid food. Mean number of laser sessions required was 3.3. The mean weight of the patients also increased from 45.13 Kg to 47.71 Kg. Three patients developed an esophageal perforation (6.6%), out of whom two died. No other major complication was observed. CONCLUSION: Nd:YAG laser is thus an excellent means of palliation of distressful symptom of carcinoma of esophagus with expectable morbidity and mortality.

Carcinoma, Squamous Cell↗
PubMed2002

Bronchial stenosis after blunt chest trauma.

A young boy who sustained blunt chest trauma 24 months back, presented with repeated chest infections. His chest skiagram revealed right hemithorax opaque and CT scan of thorax showed collapse of right lung. Fiberoptic bronchoscopy helped to diagnose the post-traumatic stenosis of right main bronchus. Laser resection was utilized to restore the patency.

Adolescent↗
PubMed2002

Sacral perineural cyst presenting as chronic perineal pain: a case report.

We present an interesting case of sacral perineural cyst which caused chronic perineal pain. Perineural cyst is relatively rare, especially the sacral region. Chronic perineural pain is an often encountered problem that is difficult to evaluate and sacral perineural cyst may be the etiology of chronic perineal pain in many instances.

Bone Cysts↗
PubMed2001

Chromium chloride inhibits oxidative stress and TNF-alpha secretion caused by exposure to high glucose in cultured U937 monocytes.

Chromium supplementation has been proposed to promote the action of insulin and the lowering of blood glucose levels in diabetic patients. However, the molecular mechanism by which chromium increases insulin sensitivity is not known. Using U937 monocytes as a cell culture model, this study demonstrates that chromium inhibits the secretion of TNF-alpha, a cytokine known to inhibit the sensitivity and action of insulin. U937 cells were cultured with high levels of glucose (mimicking diabetes) in the presence or absence of chromium chloride in the medium at 37 degrees C for 24 h. This study demonstrates that chromium supplementation prevents the increase in TNF-alpha levels and oxidative stress caused by the high levels of glucose in cultured U937 monocytic cells. Similarly, chromium supplementation prevented elevated TNF-alpha secretion and lipid peroxidation levels in H(2)O(2)-treated U937 cells. This study demonstrates for the first time that chromium supplementation inhibits TNF-alpha secretion in U937 monocytes cultured in high-glucose medium, which appears to be mediated by its antioxidative effect. This provides evidence for a novel molecular mechanism by which chromium supplementation may increase insulin sensitivity and glycemic control in diabetic patients.

Antioxidants↗
PubMed2001

Xanthine oxidase-derived reactive oxygen metabolites contribute to liver necrosis: protection by 4-hydroxypyrazolo[3,4-d]pyrimidine.

Xanthine oxidase (XO) generates reactive oxygen metabolites (ROM) as a by-product while catalyzing their reaction. The present study implicates these ROM in the pathogenesis of liver necrosis produced in rats by the intraperitoneal administration of thioacetamide (TAA; 400 mg/kg b.wt.). After 16 h of TAA administration, the activity of rat liver XO increased significantly compared to that of the control group. At the same time, the level of serum marker enzymes of liver necrosis (aminotransferases and alkaline phosphatase) and tissue malondialdehyde content also increased in TAA treated rats. Tissue malondialdehyde concentration is an indicator of lipid peroxidation and acts as a useful marker of oxidative damage. Pretreatment of rats with XO inhibitor (4-hydroxypyrazolo[3,4-d]pyrimidine; allopurinol (AP)) followed by TAA could lower the hepatotoxin-mediated rise in malondialdehyde level as well as the level of marker enzymes associated with liver necrosis. The survival rate also increased in rats given AP followed by the lethal dose of TAA. In either case, the effect of AP was dose-dependent. Results presented in the paper indicate that increased production of XO-derived ROM contributes to liver necrosis, which can be protected by AP.

Alkaline Phosphatase↗
PubMed2001

Dynamin inhibits phosphatidylinositol 3-kinase in hematopoietic cells.

Phosphatidylinositol 3-kinase (PI 3-kinase) plays a role in late stages of endocytosis as well as in cellular proliferation and transformation. The SH3 domain of its regulatory p85 subunit stimulates the GTPase activity of dynamin in vitro. Dynamin is a GTPase enzyme required for endocytosis of activated growth factor receptors. An interaction between these proteins has not been demonstrated in vivo. Here, we report that dynamin associates with PI 3-kinase in hematopoietic cells. We detected both p85 and PI 3-kinase activity in dynamin immune complexes from IL-3-dependent BaF3 cells. However, this association was significantly reduced in BaF3 cells transformed with the BCR/abl oncogene. After transformation only a 4-fold increase in PI 3-kinase activity was detected in dynamin immune complexes, whereas grb2 associated activity was elevated 20-fold. Furthermore, dynamin inhibited the activity of both purified recombinant and immunoprecipitated PI 3-kinase. In BaF3 cells expressing a temperature-sensitive mutant of BCR/abl, a significant decrease in p85 and dynamin association was observed 4 h after the induction of BCR/abl activity. In contrast, in IL-3-stimulated parental BaF3 cells, this association was increased. Our results demonstrate an in vivo association of PI 3-kinase with dynamin and this interaction regulates the activity of PI 3-kinase.

Animals↗
PubMed2001

Pyridoxine and pyridoxamine inhibits superoxide radicals and prevents lipid peroxidation, protein glycosylation, and (Na+ + K+)-ATPase activity reduction in high glucose-treated human erythrocytes.

Vitamin B(6) (pyridoxine) supplementation has been found beneficial in preventing diabetic neuropathy and retinopathy, and the glycosylation of proteins. Oxygen radicals and oxidative damage have been implicated in the cellular dysfunction and complications of diabetes. This study was undertaken to test the hypothesis that pyridoxine (P) and pyridoxamine (PM) inhibit superoxide radical production, reduce lipid peroxidation and glycosylation, and increase the (Na+ + K+)-ATPase activity in high glucose-exposed red blood cells (RBC). Superoxide radical production was assessed by the reduction of cytochrome C by glucose in the presence and absence of P or PM in a cell-free buffered solution. To examine cellular effects, washed normal human RBC were treated with control and high glucose concentrations with and without P or PM. Both P and PM significantly lowered lipid peroxidation and glycated hemoglobin (HbA(1)) formation in high glucose-exposed RBC. P and PM significantly prevented the reduction in (Na+ + K+)-ATPase activity in high glucose-treated RBC. Thus, P or PM can inhibit oxygen radical production, which in turn prevents the lipid peroxidation, protein glycosylation, and (Na+ + K+)-ATPase activity reduction induced by the hyperglycemia. This study describes a new biochemical mechanism by which P or PM supplementation may delay or inhibit the development of complications in diabetes.

Cytochrome c Group↗
PubMed2001

An experimental and theoretical study of excited-state dipole moments of some flavones using an efficient solvatochromic method based on the solvent polarity parameter, E(N)(T).

The electronic absorption and fluorescence spectra of some biologically active natural flavones have been recorded at room temperature (298 K) in solvents of different polarities. The effects of the solvents upon the spectral properties are discussed. Difference in fluorescence intensity of flavones has been explained on the basis of intersystem crossing and degree of non-planarity calculated theoretically using Austin Model 1 (AM1) method. Excited-state dipole moments have been determined using the solvatochromic method based on the microscopic solvent polarity parameter, E(N)(T). A reasonable agreement has been observed between experimental and AM1 calculated dipole moment changes. Our results are found to be quite reliable in view of the fact that the correlation of the solvatochromic Stokes shifts with microscopic solvent polarity parameter, E(N)(T) is superior to that obtained using bulk solvent polarity functions for all the systems studied here.

Flavonoids↗
PubMed2001

Intramolecular excited-state proton-transfer studies on flavones in different environments.

The absorption and fluorescence spectra of some biologically active flavones have been studied as a function of the acidity (pH/H0) of the solution. Dissociation constants have been determined for the ground and first excited singlet states. The results are compared with those obtained from Forster-Weller calculations. The acidity constants obtained by fluorimetric titration method are in complete agreement (in most of the systems) with ground state data indicating a excited state deactivation prior to prototropic equilibration. Compared to umbelliferones, flavones are only weakly fluorescent in alkaline solution. This behaviour is explained by the small energy difference between the singlet excited state and triplet excited state giving rise to more efficient intersystem crossing. Most of the flavones studied here undergo adiabatic photodissociation in the singlet excited state indicating the formation of an exciplex or a phototautomer.

Flavonoids↗