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Biomedical subjects

S Bhaduri

Publications and source records attributed to S Bhaduri.

At least 37 records · Page 2Linked to original sources
PubMed1997

GP's management of genital Chlamydia: a survey of reported practice.

BACKGROUND: Genital chlamydial infection is the commonest curable sexually transmitted disease in the industrialized world. Little is known about how GPs manage this condition. OBJECTIVES: We aimed to determine current knowledge concerning genital chlamydia among GPs and to establish how patients with this infection are managed in primary care. METHODS: A confidential self-administered postal questionnaire survey was sent to all 494 GPs in one English health district (Leicestershire). RESULTS: Completed questionnaires were returned by 290 GPs (a response rate of 59%). A much higher proportion of GPs had tested and/or treated female patients for chlamydia [70%, 95% confidence interval (CI) 64-75%] as opposed to male patients (20%, CI 15-25%). Female patients (70%, CI 64-75%) were also more likely to be managed in general practice than male patients (56%, CI 50-62%). A majority of GPs (66%, CI 60-72%) routinely used an appropriate method of testing for chlamydia although a high vaginal swab, an inappropriate method of testing, was used by a fifth of GPs (19%, CI 15-24%). A large number of different treatment regimes were used by GPs. The majority of GPs (85%, CI 79-89%) prescribed an appropriate antibiotic although few GPs (19%, CI 14-25%) specified a chlamydia treatment regime in accordance with accepted international guidelines with respect to drug, dosage and duration of therapy. CONCLUSIONS: Female patients with known or suspected genital chlamydial infection are commonly managed in UK general practice. There is scope to improve the management of this infection in general practice.

Anti-Bacterial Agents↗
PubMed1997

Direct detection and isolation of plasmid-bearing virulent serotypes of Yersinia enterocolitica from various foods.

A procedure was developed for direct detection, isolation, and maintenance of plasmid-bearing virulent serotypes of Yersinia enterocolitica from different food sources. Plasmid-bearing virulent strains of Y. enterocolitica representing five serotypes were simultaneously detected and isolated from enriched swab samples of artificially contaminated pork chops, ground pork, cheese, and zucchini, using Congo red binding and low-calcium-response tests. The method was also effective in isolating plasmid-bearing virulent strains of Y. enterocolitica from naturally contaminated porcine tongues. Virulence of the strains isolated from these foods was confirmed by PCR, the expression of plasmid-associated phenotypes, and mouse pathogenicity.

Animals↗
PubMed1997

Use of a single procedure for selective enrichment, isolation, and identification of plasmid-bearing virulent Yersinia enterocolitica of various serotypes from pork samples.

Many selective enrichment methods for the isolation of Yersinia enterocolitica from foods have been described. However, no single isolation procedure has been described for the recovery and identification of various plasmid-bearing serotypes. A single improved procedure for selective enrichment, isolation, identification, and maintenance of plasmid-bearing virulent serotypes of Y. enterocolitica from pork samples was developed. Enrichment at 12 degrees C in Trypticase soy broth containing yeast extract, bile salts, and Irgasan was found to be an efficient medium for the recovery of plasmid-bearing virulent strains of Y. enterocolitica representing O:3; O:8; O:TACOMA; O:5, O:27; and O:13 serotypes. MacConkey agar proved to be a reliable medium for the isolation of presumptive colonies, which were subsequently confirmed as plasmid-bearing virulent strains by Congo red binding and low calcium response. Further confirmation by multiplex PCR employed primers directed at the chromosomal ail and plasmid-borne virF genes, which are present only in pathogenic strains. The method was applied to pig slaughterhouse samples and was effective in isolating plasmid-bearing virulent strains of Y. enterocolitica from naturally contaminated porcine tongues. Strains isolated from ground pork and tongue expressed plasmid-associated phenotypes and mouse pathogenicity.

Animals↗
PubMed1997

Clinical aspects of sensitization.

1. The incidence of broad sensitization has decreased significantly over the past 8 years, probably due to a decrease in pretransplant blood transfusions. Graft survival rates among broadly sensitized patients have improved over this time period (76% graft survival at 2 years posttransplant for patients transplanted in 1995-1996 compared with 66% for patients transplanted in 1989-1990). This is probably due to an improvement in immunosuppression and a related decrease in the incidence of acute rejection episodes. 2. As has been shown before, blood transfusions, previous pregnancies and failed allografts independently increased the incidence of sensitization. It is clear that certain subgroups of patients are more likely to become sensitized, given antigenic stimulation, as evidenced, for example, by the fact that 52% of patients receiving more than 10 units of blood prior to transplant were relatively unsensitized. Males seem to be less apt than nulliparous females to become broadly sensitized, although this may be due to the lower age of nulliparous females. Asians are the least likely race to become broadly sensitized. Among multiparous Asians who received more than 5 units of blood, 27% were broadly sensitized compared with 35% of comparable Whites and African Americans. 3. The incidence of acute rejection episodes increased with increasing degrees of sensitization. About 46% of first cadaveric allograft recipients with PRA levels greater than 50% had at least one acute rejection episode within 6 months after transplantation compared with 38% of unsensitized individuals. In addition, sensitized individuals were more likely to have an episode of early acute rejection before discharge from the hospital. 4. Induction with antilymphocyte antibody preparation was more commonly used in broadly sensitized patients. However, this therapeutic modality did not reduce the incidence of rejection episodes measured at 6 months posttransplant. In addition, the use of induction therapy for broadly sensitized patients has decreased with the advent of newer immunosuppressive protocols that include Neoral, MMF and FK506. 5. There was an association between the incidence of broad sensitization and delayed graft function. Induction therapy was more commonly used in patients with both delayed graft function and broad sensitization, although the decision to use this therapeutic modality seems to be made based on the presence of broad sensitization rather than the presence of delayed graft function. 6. Choosing the optimal immunosuppressive drug regimen is an important decision in broadly sensitized individuals because of the increase in acute rejections and decrease in overall graft survival in this group. Classic teaching suggests that this group of patients should be administered induction therapy with antilymphocyte antibody preparations. Early data suggests, however, that the combination of Neoral, mycophenolate and prednisone may be the optimal regimen for these individuals with respect to graft survival and that the addition of antibody induction therapy to any of the other commonly used regimens does not improve graft survival (at least up to 3 years after transplantation).

Blood Transfusion↗
PubMed1995

Expanded response surface model for predicting the effects of temperatures, pH, sodium chloride contents and sodium nitrite concentrations on the growth rate of Yersinia enterocolitica.

The previously reported data set for the low temperature (5, 12 and 19 degrees C) of Yersinia enterocolitica was expanded to include higher abusive temperature (28, 37 and 42 degrees C). In addition to temperature, the data set included the effects and interactions of pH (4.5-8.5), sodium chloride (0.5-5%) and sodium nitrite (0-200 micrograms ml-1) on the aerobic growth of Y. enterocolitica in brain heart infusion broth. Growth curves were modeled by fitting viable count data to the Gompertz equation. Quadratic models of natural logarithm transformations of the Gompertz B and M values and the derived values for lag phase durations and generation times were obtained using response surface analyses. Predictions based on the models for B and M values were comparable to predictions based on the derived values. These revised models provide an expanded means for rapidly estimating how the bacterium is likely to respond to any combination of the four variables within the specified ranges.

Aerobiosis↗
PubMed1994

Response surface model of the effect of pH, sodium chloride and sodium nitrite on growth of Yersinia enterocolitica at low temperatures.

A fractional factorial design was used to measure the effects and interactions of temperature (5, 12, 19 degrees C), pH (4.5-8.5), sodium chloride (0.5-5%) and sodium nitrite (0-200 micrograms/ml) on the aerobic growth of Y. enterocolitica in brain heart infusion broth. Growth curves were modeled by fitting plate count data to the Gompertz equation. Quadratic models of natural logarithm transformations of the Gompertz B and M values and the derived values for lag phase durations and generation times were obtained using response surface analysis. Predictions based on the models for B and M values were comparable to predictions based on the derived values. These models provide a means for rapidly estimating how the bacterium is likely to respond to any combination of the four variables within the specified ranges.

Cold Temperature↗
PubMed1993

Studies on Escherichia coli serotype O157:H7 strains containing a 60-MDa plasmid and on 60-MDa plasmid-cured derivatives.

Seventeen strains of Escherichia coli serotype O157:H7 producing Shiga-like toxin were examined for the presence of plasmids and for the ability to adhere to HEp-2 and Intestine 407 cells. All of the strains possessed a common 60-MDa plasmid. To determine the role of the 60-MDa plasmid, plasmid-cured strains were compared with the parent strains for their ability to produce pili and to adhere to epithelial cells in culture. The total cell lysate protein and outer-membrane protein (OMP) profiles were also compared. Both the parent strains and their plasmid-cured derivatives produced pili. Immunofluorescence assay results indicated that the plasmid-cured and parent strains adhered equally well to HEp-2 and Intestine 407 cells; overall adherence was greater with intestinal cells than HEp-2 cells. SDS-PAGE of polypeptides synthesised in an E. coli system in vitro showed that plasmid DNA encodes c. 35 proteins. SDS-PAGE of OMP preparations demonstrated that the 60-MDa plasmid appears to be involved in the synthesis of a 33-kDa OMP. Two strains cured of the 60-MDa plasmid, one that possessed no plasmids and one that still contained a 2.2-MDa plasmid, produced exopolysaccharide (EPS) when cultured on solid medium at 25 degrees C. Two other strains, which were cured of the 60-MDa plasmid but contained a 4.5-MDa plasmid, did not produce visible amounts of EPS. Gas chromatography analysis showed that the EPS consisted of fucose, glucose and galactose in an approximate molar ratio of 2.0:0.9:1.1 and also had 7% of a uronic acid sugar as part of its structure.

Bacterial Adhesion↗
PubMed1991

Catabolite repression vs derepression, an approach to differentiation during sporulation in Bacillus subtilis.

Glutamine, like glucose, repressed sporulation and the synthesis of mycobacillin and dipicolinic acid by Bacillus subtilis, and these syntheses were depressed by dibutyryl cyclic GMP but not by dibutyryl cyclic AMP. Neither of these dibutyryl cyclic nucleotides affected sporulation or a number of spore-associated parameters in the strain under normal physiological conditions. Mutants insensitive to glutamine repression were indifferent to the addition of either of the dibutyryl cyclic nucleotides both in the presence and in the absence of glutamine. Sporulation resulted from the remission of repression obtained under the catabolically active state.

Bacillus subtilis↗
PubMed1990

Calcium-responsive expression of plasmid-mediated outer membrane proteins from Yersinia enterocolitica grown on solid media.

In vitro synthesis of proteins directed by Yersinia enterocolitica virulence plasmid DNA was studied using a cell-free Escherichia coli coupled transcription-translation system. Out of a total of twenty-four polypeptides synthesized in vitro, ten were identified (based on virtually identical molecular masses) as outer membrane proteins synthesized in vivo when virulent plasmid-bearing Y. enterocolitica cells were grown on four different solid media. Two high molecular weight outer membrane proteins synthesized in vivo by plasmid-bearing cells were not detected in the in vitro protein synthesizing system. Different plasmid-mediated outer membrane proteins were expressed in vivo in Y. enterocolitica grown on different media. Y. enterocolitica grown on media with high calcium concentration (1.4-1.5 mM) expressed twice the number of lower molecular weight outer membrane proteins than the organism grown on low calcium (238-311 microM) media. This is the first report that a single serotype has been shown to synthesize all the reported virulence plasmid-encoded outer membrane proteins including three new polypeptides. The constituents in the medium as well as the level of calcium appeared to have a regulatory role in plasmid gene expression for lower molecular weight outer membrane proteins.

Bacterial Outer Membrane Proteins↗
PubMed1990

Simple assay of calcium dependency for virulent plasmid-bearing clones of Yersinia enterocolitica.

A simplified procedure to detect the calcium dependency of virulent plasmid-bearing strains of Yersinia enterocolitica was developed. A low-calcium, agarose-based medium of brain heat infusion with added magnesium effectively differentiated plasmid-bearing and plasmidless isolates. Further, the expression of calcium dependency in plasmid-bearing strains of Y. enterocolitica as measured by the average colony diameter was proportional to the calcium concentration of the assay.

Calcium↗
PubMed1989

Repression of sporulation: isolation and characterization of repression-resistant mutants of Bacillus subtilis.

The sporulation of Bacillus subtilis B34 was repressed by 24 h if glutamine or ammonium chloride but not glutamate was added at late log phase (70 h) when glucose and glutamate were nearly exhausted. Glutamine-resistant mutants were isolated by selective heat treatment during the delay period induced by glutamine. Glutamine-resistant mutants showed cross resistance not only against ammonium chloride but also against glucose just as glucose-resistant mutants showed resistance against nitrogenous catabolites.

Ammonium Chloride↗
PubMed1987

Assay of crystal violet binding for rapid identification of virulent plasmid-bearing clones of Yersinia enterocolitica.

A rapid, reliable, and simple method based on the binding of crystal violet (CV) is described for differentiating virulence-plasmid-bearing strains of Yersinia enterocolitica from their plasmidless derivatives. As with other plasmid-mediated properties of this organism, the binding of CV occurs at 37 degrees C but not at 25 degrees C. The CV-binding technique provides a simple and efficient means of screening Y. enterocolitica for virulence and for identifying individual plasmid-bearing colonies.

Animals↗
PubMed1983

Antimicrobial prophylaxis in acute leukaemia: prospective randomized study comparing two methods of selective decontamination.

In a prospective study the efficacy of two regimens for selective decontamination of the digestive tract was studied in patients with acute leukaemia during remission induction therapy. Seventy-eight patients were randomized to receive either a combination of cotrimoxazole, polymyxin B and nystatin (group A) or a combination of nalidixic acid, polymyxin B, neomycin and nystatin. With both regimens the gastrointestinal tract could be decontaminated equally effectively from potential pathogens. In the oropharyngeal region the decontamination from Enterobacteriaceae was significantly better in group A (P less than 0.01). In both groups less than 10% of the acquired infections were caused by gram-negative bacilli and no gram-negative septicaemia occurred in either group. The median time interval until the first acquired infection was 17 days in group A and 36 days in group B, respectively (P less than 0.05). It is concluded that regimen A might be more effective than regimen B though both regimens prevent reliably severe gram-negative infections.

Acute Disease↗