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Biomedical subjects

B Wren

Publications and source records attributed to B Wren.

18 recordsLinked to original sources
PubMed2004

Reducing absenteeism in hospital cleaning staff: pilot of a theory based intervention.

AIMS: To develop, pilot, and evaluate a workplace intervention to reduce sickness absence, based on a demand-control-support model of job strain. METHODS: Changes in the working arrangements of hospital cleaning staff were introduced with the aim of increasing their control over work and the support received at work. The study design was quasi-experimental, with 221 cleaning staff in the intervention group and 91 catering staff in the control group. The dependent variable was the difference in percentage monthly sickness absence between the 12 months preceding and following the intervention. Differences in sickness absence between staff groups for each month after the intervention were compared with differences between staff groups for the equivalent month one year prior to it. RESULTS: There was a significant reduction in the difference in sickness absence rates between the intervention and control group of 2.3% in the six months after the intervention, compared to the six months before. The difference was not maintained at 12 months. CONCLUSIONS: These results suggest that a workplace intervention aimed at increasing control and support at work has a small effect on reducing sickness absence among hospital cleaning staff in the short term. Future research should seek to replicate this effect in larger, experimental studies, analyse postulated mediators of such theory based interventions, and develop interventions that maintain improvement.

Absenteeism↗
PubMed2001

Molecular characterization of the surface layer proteins from Clostridium difficile.

Many bacteria express a surface-exposed proteinaceous layer, termed the S-layer, which forms a regular two-dimensional array visible by electron microscopy. Clostridium difficile is unusual in expressing two S-layer proteins (SLPs), which are of varying size in a number of strains. In an approach combining molecular biology with mass spectrometric sequencing strategies, we have identified the structural gene (slpA) for the S-layer from three strains of C. difficile. Both proteins are derived from a common precursor, and processing involves the removal of a signal peptide and a second cleavage to release the two mature SLPs. To our knowledge, this is the first example in which two SLPs have been shown to derive from a single gene product through post-translational processing, rather than from the expression of separate genes. The higher molecular weight (MW) SLP is highly conserved among the three strains, whereas the lower MW SLP shows considerable sequence diversity, reflecting the results from Western blotting. The high-MW SLP shows weak homology to N-acetyl muramoyl-L-alanine amidase from Bacillus subtilis, and both the native SLP from C. difficile and a recombinant protein expressed in Escherichia coli were found to display amidase activity by zymography. The high-MW SLPs showed evidence of glycosylation, whereas the lower MW proteins did not. A family of genes with sequence homology to the amidase domain of the high-MW SLP was identified in the C. difficile strain 630 genome, some of which are located in the same region of the genome as slpA and were shown by reverse transcription-polymerase chain reaction (RT-PCR) analysis to be transcribed.

Amidohydrolases↗
PubMed1999

Effect of hormone replacement therapy on left ventricular hypertrophy.

The mechanisms behind the reduction in cardiovascular morbidity and mortality in postmenopausal women receiving hormone replacement therapy are not fully understood. In this case-control study, we report a statistically significant lower left ventricular mass in a group of elderly women who were receiving hormone replacement therapy for >10 years than in age-matched controls.

Aged↗
PubMed1998

A cohort study of hormone replacement therapy given to women previously treated for breast cancer.

UNLABELLED: Women who have been previously treated for breast cancer are usually advised to avoid hormone therapy for fear of increasing their risk of tumor recurrence. However, for some women, menopausal symptoms are so severe that their quality of life is poor. Because ethic committees are reticent to permit a double-blind randomized trial, we performed a cohort study of hormone therapy after breast cancer. METHODS: The study group comprised 1472 women with breast cancer. A total of 167 subjects had used an oral or transdermal estrogen after their treatment for breast cancer. Amongst these estrogen users, 152 (91%) had also used a progestin. In total, 106 other women had used a progestin alone as a treatment for menopausal flushes and not as a treatment for breast cancer. Cox regression analysis was performed using estrogen as a time-dependent covariate with disease-free interval as the outcome. RESULTS: The uncorrected hazard ratio for the estrogen-progestin users was 0.67 (95% confidence interval (CI) 0.38-1.16) and for the progestin alone users was 0.85 (95% CI 0.44-1.65). CONCLUSIONS: This study was unable to demonstrate a significant increase in risk of breast cancer recurrence for women who used HRT and suggests that the time is now appropriate for a randomized prospective trial of hormone therapy after breast cancer.

Breast Neoplasms↗
PubMed1998

Influence of route of vaccine administration against experimental intramammary infection caused by Escherichia coli.

The route of immunization of a commercially available Escherichia coli J5 bacterin was investigated. Jersey cows were randomly assigned to one of three treatment groups: 1) unvaccinated (control), 2) vaccinated subcutaneously in the neck, and 3) vaccinated in the area of the supramammary lymph node. Cows were vaccinated at drying off and at 2 wk prior to anticipated calving. Two quarters of each cow were challenged with approximately 60 cfu of E. coli at 14 d postcalving. Route of immunization in the neck or the area of the supramammary lymph node did not influence severity of coliform mastitis. However, the mean number of colony-forming units of E. coli recovered from challenged quarters was significantly lower for vaccinated cows than for control cows at 24 h postchallenge. A quicker milk yield recovery following intramammary challenge was also observed for vaccinated cows. Serum immunoglobulin (Ig) G, IgG1, and IgG2 and whey IgG1 and IgG2 antibody titers against E. coli J5 whole-cell antigens were significantly enhanced in vaccinated cows. Somatic cell counts in milk from challenged quarters and rectal temperatures following intramammary challenge were not different for cows across treatment groups. Immunization did not prevent intramammary infection.

Animals↗
PubMed1997

Are bacterial exotoxins cytokine network regulators?

Bacterial exotoxins are generally thought to act by damaging cells or altering cell metabolism. However, recent work has established that many exotoxins modulate eukaryotic cell cytokine synthesis. Cytokine induction may play a significant role in exotoxin action, and therapeutic targeting of cytokines could be beneficial in infectious diseases involving bacterial exotoxins.

Adenosine Diphosphate Ribose↗
PubMed1996

Epidemiology and typing of Clostridium difficile.

Clostridium difficile is now established as the most common nosocomial enteric pathogen causing pseudomembranous colitis, antibiotic-associated colitis and antibiotic-associated diarrhoea. Antibiotic therapy is the most important risk factor in colonization and infection with C. difficile. However, other factors are involved such as age and underlying illness. The introduction of reliable typing and fingerprinting methods has demonstrated hospital acquisition and cross-infection with C. difficile and has been important in improving our understanding of the epidemiology and pathogenicity of C. difficile.

Anti-Bacterial Agents↗
PubMed1996

Menorest: a clinical overview.

Menorest is an adhesive matrix patch containing 17 beta-estradiol at various doses. Menorest 50 micrograms/day has been compared with oral equine estrogens (Premarin 0.625 mg/day) and with a reservoir patch, Estraderm at 50 micrograms/day. Menorest was as effective as either of the two comparison treatments in controlling vasovagal and urinogenital symptoms of the menopause. None of the treatments produced any significant effects on blood pressure or the lipid profile. All three treatments were well-tolerated, but there appeared to be slightly more side effects with Estraderm than with Menorest, particularly with regard to local erythema and itching.

Administration, Cutaneous↗
PubMed1996

Hormonal therapy and genital tract cancer.

The use of hormonal replacement therapy following genital tract cancer is often denied to women because of the fear of increasing the risk of recurrence or new growth. The paucity of articles written on this subject during the past decade is an indication of the attitude of the medical profession to the needs of women suffering from symptoms of sex hormone deficiency. During 1994-1995 there were few articles published on the use of hormonal therapy to treat menopausal symptoms following genital tract cancer. Several articles, however, reviewed the relationship between hormones and genital tract cancer, some explored the value of antioestrogens in controlling recurrent or secondary disease, and a few others discussed the risk of developing uterine cancer when tamoxifen was used to manage postmenopausal breast cancer. Some suggestions are made that will allow women suffering from symptoms of hormone deficiency to receive alternative regimens of hormonal therapy. Maintaining quality of life without reducing the potential length of life is paramount in reaching a decision on the use of hormonal therapy following genital tract cancer.

Contraindications↗
PubMed1995

Efficacy and tolerance of Menorest compared to Premarin in the treatment of postmenopausal women. A randomised, multicentre, double-blind, double-dummy study.

Two-hundred and fourteen (214) menopausal women with moderate to severe vasomotor symptoms, aged 40-65 years, were randomised. After a 4-week treatment-free period, each women received a continuous regimen of Menorest 50 twice weekly or Premarin 0.625 mg daily, for 12 weeks. Didrogesterone 10 mg was also given to all women for 12 days of every 28-day cycle. The objectives were to compare the efficacy and safety profiles of Menorest and an oral estrogen. A statistically significant reduction in the mean number of hot flushes occurred in each group compared to baseline with a decrease from 7.1 at baseline to 0.9 at 12 weeks in the Menorest group, and from 6.7 to 0.5 in the oral estrogen group; there was no statistically significant difference between the two groups (P = 0.36). With each successive treatment cycle, there was a continuous improvement in the number of hot flushes. The incidence and severity of menopausal symptoms were reduced in the same manner in both groups. There were no statistically significant differences in the mean plasma estradiol and estrone concentrations between the two treatment groups after 10 weeks of therapy. The mean estradiol to estrone ratio was similar in both groups, as was the number of adverse events observed. In summary, Menorest was as effective as an oral estrogen in alleviating menopausal symptoms.

Administration, Cutaneous↗
PubMed1993

The efficacy of the pipelle endometrial biopsy in detecting endometrial carcinoma.

The purpose of this study was to determine the efficacy rate of the Pipelle endometrial biopsy sampler (Pipelle de Cornier) (1) in detecting endometrial carcinoma, and to analyze the tumour variables that may influence the success rate. Thirty seven women with known endometrial carcinoma were tested preoperatively; there were 25 correct diagnoses (67%), the remaining 12 cases (33%) failed to demonstrate the correct diagnosis: 4 showed 'atypical epithelium', 2 showed 'atypical hyperplasia', 3 showed 'nonspecific epithelium' and the remaining 3 showed 'necrotic hyalinized material'. All cases were analyzed with respect to several tumour parameters, including the degree of differentiation, tumour volume, depth of invasion, and the extent to which the tumour filled the endometrial cavity. Poor results were obtained in well differentiated, low volume, and minimally invasive tumours, i.e. most early tumours, precluding its use as a screening tool. A positive biopsy can save patients the time, cost, and inconvenience of a dilatation and curettage. However, in the light of these findings, a nonspecific finding should be interpreted with caution.

Biopsy↗
PubMed1990

Genetic analysis of a tetracycline resistance element from Clostridium difficile and its conjugal transfer to and from Bacillus subtilis.

A tetracycline resistance (Tcr) determinant from Clostridium difficile strain 630 was cloned into the Escherichia coli plasmid vector pUC13. The resulting plasmid pPPM20, containing an insert of 3.4 kbp, was mapped and a 1.1 kbp SacI-HindIII fragment wholly within the Tcr gene was identified. Dot-blot hybridization studies with the 1.1 kbp fragment showed that the Tcr gene belonged to hybridization class M. Tcr could be transferred between C. difficile strains and to Bacillus subtilis at a frequency of 10(-7) per donor cell. The element could be returned from B. subtilis to C. difficile at a frequency of 10(-8) per donor cell. This is the first demonstration of C. difficile acting as a recipient in intergeneric crosses. DNA from C. difficile transconjugants digested with EcoRV always has two hybridizing fragments of 9.5 and 11.0 kbp when probed with pPPM20. DNA from B. subtilis transconjugants digested with EcoRV produced one hybridizing band of variable size when probed with pPPM20. The behaviour of the element was reminiscent of the conjugative transposons. Therefore we compared the element to the conjugative transposon Tn916. The HincII restriction maps of the two elements differed and no hybridization was detected to oligonucleotides directed to the ends of Tn916. However, the elements do have some sequence homology, detected by hybridization analysis.

Bacillus subtilis↗
PubMed1988

Clostridium difficile infection in patients with haematological malignant disease. Risk factors, faecal toxins and pathogenic strains.

Two hundred and forty-eight patients from shared oncology and general medical wards were prospectively studied over a 6-month period for carriage of Clostridium difficile during an outbreak of clinical disease with an epidemic strain of the organism. Risk factors for infection were assessed. Acute leukaemia and/or its treatment were identified as significantly increasing the risk of infection. The relationship between the type of C. difficile isolated (as defined by a typing system based on the incorporation of [35S]methionine into bacterial proteins followed by gel electrophoresis), the presence of faecal toxins A and B and clinical symptoms were analysed. Carriage of the epidemic strain, type X, had a significant association with symptoms amongst oncology patients, with two thirds of these patients having detectable faecal toxin A and one third detectable faecal toxin B. During an outbreak of C. difficile-associated disease, typing the organism and assaying for both faecal toxins in symptomatic patients may be of benefit in determining which patients require specific, urgent treatment.

Adolescent↗
PubMed1987

Association between production of toxins A and B and types of Clostridium difficile.

One hundred and seventy two strains of Clostridium difficile isolated from 62 patients with antibiotic associated diarrhoea or pseudomembranous colitis were analysed for the production of toxins A and B and typed using 35S-methionine labelling followed by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). There was a correlation between production of toxins A and B and the type of C difficile. One hundred and forty four of 172 strains were either high or low producers of both toxins. Toxins were not detected in 28 of 172 strains. Types A and Y were consistently non-toxin producers; types B and E were high toxin producers. Type X, the epidemic strain, showed variable toxin production. Symptoms of 49 patients with haematological malignant pathology who were part of a documented outbreak of antibiotic associated diarrhoea, were analysed in relation to toxin production and type of the clinical strains isolated. In general, there was a correlation between symptoms of antibiotic associated diarrhoea, the type of C difficile, and its potential for producing toxins.

Anti-Bacterial Agents↗
PubMed1985

The effect of low-dose piperazine oestrone sulphate and low-dose levonorgestrel on blood lipid levels in post-menopausal women.

Prolonged used of oestrogens has been shown to reduce the risk of arteriosclerotic heart disease by increasing the levels of circulating high density lipoprotein cholesterol. It has also been shown that progestogens derived from the 19-nortestosterone molecule will reverse this beneficial effect when given in 250-500 mg doses. When levonorgestrel was used in doses as low as 30 micrograms daily, there was no change in cholesterol levels over a period of 6 mth, suggesting that the adverse effect of the androgenic type progestogens is dose-related and is probably only significant when extremely high dosages are administered.

Cholesterol↗