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Biomedical subjects

S Ghosh

Publications and source records attributed to S Ghosh.

At least 631 records · Page 35Linked to original sources

Low bone mineral density in Crohn's disease, but not in ulcerative colitis, at diagnosis.

BACKGROUND/AIMS: The pathogenesis of low bone mineral density in patients with inflammatory bowel disease is unclear, and the relevance of secondary osteopenic influences is controversial. Our aim was to study bone mineral density in newly diagnosed patients. METHODS: Bone mineral density and biochemical parameters of bone metabolism were measured in 15 patients with Crohn's disease and 15 patients with ulcerative colitis, all of whom were newly diagnosed. Lumbar and forearm bone mineral densities were measured by dual energy x-ray absorptiometry, and Z scores were obtained by comparison with age- and sex-matched normal values. Twenty-three patients had repeat measurements 1 year later, and 20 had received systemic steroids. RESULTS: At diagnosis, the mean Z score for patients with Crohn's disease (spine, -1.06 +/- 0.86; forearm, -1.04 +/- 0.86) was significantly lower than that for patients with ulcerative colitis (spine, -0.03 +/- 1.16; forearm, 0.11 +/- 1.24). Inflammatory activity, disease localization, body mass index, smoking habits, sex, physical activity, or biochemical parameters did not account for this difference. Spine and forearm Z scores were significantly correlated. Mean Z scores after 1 year were not significantly different from initial Z scores. CONCLUSIONS: At diagnosis, low bone mineralization is a feature of Crohn's disease but not ulcerative colitis. Treatment with corticosteroids did not result in further bone loss in 1 year.

Adolescent↗

Rapid detection of rotavirus by using colloidal gold particles labeled with monoclonal antibody.

A rapid single-step, sensitive and specific immunogold assay is described for detection of rotavirus. Murine monoclonal antibody (MCA) to the group antigen of rotavirus was dotted on a nitrocellulose paper strip. This was used to capture the rotavirus antigen which was revealed using a conjugate consisting of the MCA conjugated to gold particles. This assay detects 5 x 10(7) particles of rotavirus. It also acutely detected rotavirus from fecal samples, but failed to show any reaction with microscopically confirmed fecal samples containing G. lamblia and E. histolytica. The time taken for the test was approximately 10 min. Its versatility, simplicity, sensitivity and specificity makes it useful for third world countries.

Acute Disease↗

A disease locus for hereditary haemorrhagic telangiectasia maps to chromosome 9q33-34.

Hereditary haemorrhagic telangiectasia (HHT), or Osler-Weber-Rendu disease, is an autosomal dominant vascular dysplasia of unknown pathogenesis leading to 'widespread' dermal, mucosal and visceral telangiectases and recurrent haemorrhage. We have mapped the HHT gene, by linkage analysis, to markers on 9q33-34 in two large multi-generation families. Haplotype analysis and mapping of recombination breakpoints gives a 4 cM interval between D9S61 and D9S63 as the most likely location of the gene. The closest marker, D9S65, is estimated to be within 1 cM of the gene and shows a combined lod score of 11.41. Two potential candidate genes, COL5A1 and ZNF79, are also located within 9q33-34. These results provide a starting point for the eventual cloning of the HHT gene.

Adult↗

Dietary and serum magnesium levels in patients with acute myocardial infarction, coronary artery disease and noncardiac diagnoses.

OBJECTIVE: To study the relation of dietary and serum levels of magnesium (Mg) in acute myocardial infarction (AMI) and its complications in relation to noncardiac diagnoses. METHODOLOGY: Case control study in a primary and secondary care center for AMI patients. The study included 460 subjects with definite AMI (n = 335, group A), possible AMI (n = 64, group B), unstable angina (n = 19, group C) and controls with noncardiac chest pain (n = 42, group D). Demographic variables, dietary intake, and clinical and biochemical data were compared. Mean age, sex, body weight, and body mass index were comparable in all the groups. RESULTS: Dietary fat and cholesterol intakes were significantly higher and carbohydrate intakes were lower in group A, B and C patients with coronary artery disease compared to control group D. Dietary consumption of Mg was comparable in all groups; however, in 85 patients in group A (272.5 mg/day) and 17 in group B (280.4 mg/day) in whom ventricular arrhythmias were present, Mg intake was relatively lower compared to control group D (316.6 mg/day). Serum Mg levels in group A (1.66 mEq/L), B (1.65 mEq/L), and C (1.66 mEq/L) were within normal (1.74 mEq/L) limits, but were significantly lower than in control group D. CONCLUSIONS: Lower serum Mg in group A, B and C patients was attributed to increased demand during AMI, although in patients with complications (ventricular arrhythmias), Mg deficiency may in part result from relatively lower Mg intake, a hypothesis which requires further study.

Arrhythmias, Cardiac↗

Characterization of monoclonal antibodies to conserved antigens of Entamoeba histolytica and E. dispar and development of a stool ELISA.

Eight murine monoclonal antibodies (MAbs) were generated against Entamoeba histolytica NIH:200. All MAbs reacted with three axenic strains of E. histolytica, NIH:200, HM-1: IMMS, and SAW 1734R clAR, but not with enteric bacteria or Giardia lamblia. Five of the MAbs reacted with low-molecular-weight, periodate-sensitive antigens of 14-21 kD, while one (AB31) reacted with high-molecular-weight, 90 to 200-kD protein determinants. MAb PC14 appeared to be specific for antigen in its native state. Another MAb (BB12) agglutinated live trophozoites and caused membrane fluorescence in contrast to the five other MAbs tested. Although BB12 reacted with the same 14 to 21-kD band on Western blot as AC55, the latter reacted with different cytoplasmic epitopes. All the MAbs reacted to five pathogenic (E. histolytica) and six nonpathogenic (E. dispar) clinical isolates. These MAbs may be helpful for studying conserved antigens of E. histolytica and were used to develop a sandwich ELISA for the diagnosis of intestinal amoebiasis. The assay was sensitive to 60 ng of E. histolytica antigen. A comparative study of microscopic examination of stool samples and the sandwich ELISA was conducted on 102 samples from patients with gastrointestinal complaints. The ELISA could detect all microscopically positive samples with a sensitivity of 100% and specificity of 93%. A sandwich ELISA using a monoclonal antibody to conserved antigens of E. histolytica has the potential to be a reliable method for the diagnosis of intestinal amoebiasis.

Agglutination Tests↗

Achalasia of the oesophagus in elderly patients responds poorly to conservative therapy.

In a retrospective study the symptoms and results of pneumatic dilatation in achalasia of the oesophagus were analysed in 11 patients (six women) aged 65 years and above (group 1) and compared with 19 younger patients (two women, group 2) over a 48-month period. Weight loss occurred in 91% of group 1 patients and 53% of group 2 patients. Pulmonary complications were commoner in group 1 than in group 2. All patients in group 1 and 84% of patients in group 2 complained of regurgitation. Lower oesophageal sphincter pressures were similar in the groups but the median diameter of the oesophageal body was greater in group 1 patients. The duration of dysphagia before presentation was longer in group 1 (median 5 years; range 1-9 years) compared with group 2 (median 2 years; range 0.5-4 years). None of the six elderly patients receiving pharmacological treatment with nifedipine or nitrates improved while five of the six younger patients treated with medications reported transient improvement. In group 1 only 50% of the pneumatic dilatations resulted in improvement and the median duration of improvement was 12 weeks. These results were significantly worse than those in group 2 where 90% of the dilatations resulted in improvement which lasted for a median duration of 52 weeks. Long-term results were satisfactory in six of the 11 elderly patients and 16 of the 19 younger patients.

Aged↗

Inhaled nitric oxide in patients with normal and increased pulmonary vascular resistance after cardiac surgery.

We studied the haemodynamic effects of inhaled nitric oxide 40 p.p.m. in two groups of patients after cardiac surgery (mitral valve surgery or coronary artery bypass grafting). Nitric oxide caused a significant reduction in pulmonary vascular resistance after mitral valve surgery in patients who had pre-existing pulmonary hypertension, but no change in haemodynamic state in the coronary artery bypass group of patients, who had normal pulmonary arterial pressures.

Administration, Inhalation↗

The role of soda lime during administration of inhaled nitric oxide.

We have studied the ability of three commercially available preparations of soda lime to act as nitrogen dioxide scavengers during administration of inhaled nitric oxide. Soda lime, with a green to brown colour change (indicator = potassium permanganate), markedly reduced concentrations of nitrogen dioxide, but also markedly reduced inhaled concentrations of nitric oxide. The other varieties of soda lime, with colour changes from pink to white (indicator = kenazol yellow) or white to violet (indicator = ethyl violet), produced little effect on concentrations of nitrogen dioxide. None of the above soda limes can be recommended for use as a nitrogen dioxide scavenger during administration of inhaled nitric oxide.

Calcium Compounds↗

Clinical evaluation of Tc-99m cystine. A new renal radiopharmaceutical.

Tc-99m cystine has been proved to be a good renal agent in animals. Its clinical evaluation has not been reported. In this study, Tc-99m cystine is used for evaluation of renal function in normal subjects and patients with chronic renal failure as well as in renal transplant patients. The results are compared with similar studies using Tc-99m DTPA and Tc-99m GHA. The clearance values also are compared with I-131 OIH. The results show that Tc-99m cystine has good radiopharmaceutical characteristics suitable for evaluation of both renal function as well as morphology.

Cystine↗

Clinical evaluation of Tc-99m cystine. A new renal radiopharmaceutical.

Tc-99m cystine has been proven to be a good renal agent in animals, but its clinical evaluation has not been reported. In this study, Tc-99m cystine was used for evaluation of renal function in normal subjects and patients with chronic renal failure as well as in renal transplant patients. The results are compared with similar studies that used Tc-99m DTPA and Tc-99m GHA. The clearance values also have been compared with I-131 OIH clearance. The results show that Tc-99m cystine has good radiopharmaceutical characteristics suitable for evaluation of both renal function as well as morphology.

Cystine↗

Molecular cloning and sequencing of an operon, carRS of Azospirillum brasilense, that codes for a novel two-component regulatory system: demonstration of a positive regulatory role of carR for global control of carbohydrate catabolism.

A pleiotropic carbohydrate mutant, CR17, of Azospirillum brasilense RG (wild type) that assimilates C4 dicarboxylates (succinate and malate) but not carbohydrate (fructose, arabinose, galactose, glycerol, and gluconate) as C sources for growth was used to identify the car (carbohydrate regulation) locus by complementation analysis. The 2.8-kb genomic fragment that complemented the Car- defect of CR17 and overlapped the fru operon (S. Chattopadhyay, A. Mukherjee, and S. Ghosh, J. Bacteriol. 175:3240-3243, 1993) has now been completely sequenced. The sequence contains an operon, carRS, coding for two proteins, CARR and CARS, having 236 and 352 amino acid residues, respectively. The 3'-flanking region of the carRS operon showed sequence homology with the 5' terminus of the fruB gene of a related bacterium, Rhodobacter capsulatus. A complementation study with carRS deletion clones showed that only the carR+ gene was required to complement the Car- defect of CR17, signifying that the carbohydrate pleiotropy was due to a lesion within this gene. Although the 2.8-kb DNA containing the carRS operon when introduced by conjugation into CR17 also complemented the Car- defect, the complemented transconjugant was unable to utilize succinate as a C source. The reason for this is not clear. A sequence analysis of the two protein products strongly suggests that the protein pair may constitute a novel two-component regulatory system for global expression of carbohydrate catabolic pathways in A. brasilense.

Amino Acid Sequence↗

Prevention of biliary stent occlusion using cyclical antibiotics and ursodeoxycholic acid.

This study reports an open randomised controlled trial of cyclical antibiotics and ursodeoxycholic acid in prevention of plastic biliary stent occlusion. Seventy patients with malignant distal bile duct obstruction were randomised to either active treatment with cyclical antibiotics (ampicillin, metronidazole, ciprofloxacin) and ursodeoxycholic acid or no treatment after successful stent insertion. The two groups were well matched. The follow up was complete with stent occlusion or death being the end points. There was no difference in the incidence of stent occlusion between the two groups and the overall survival was similar. In conclusion, this study did not show any benefit of treatment with antibiotics and ursodeoxycholic acid in prolonging stent patency or improving survival.

Aged↗