Biomedical subjects
Publications and source records attributed to J Leggate.
TECHNIQUE: We present the use of a zig-zag bicoronal scalp incision for cranial-facial cases in paediatric neurosurgery. CONCLUSION: The authors believe that this technique leads to improved cosmesis, especially when the hair is wet.
AIMS: Different indicator enzymes and fluorogenic or chromogenic substrates were compared as detector systems in a novel polymyxin-based enzyme-linked immunosorbent assay (ELISA) for Escherichia coli O157 lipopolysaccharide (LPS) antigens. METHODS AND RESULTS: An ELISA system was developed using polymyxin immobilized in the wells of a microtitre plate as a high-affinity adsorbent for E. coli O157 LPS antigens, which were immunoenzymatically detected using anti-E. coli O157 antibody-enzyme conjugates. With peroxidase as the indicator enzyme the fluorogenic substrates Amplex Red and QuantaBlu produced only slight improvement in the performance characteristics of the polymyxin-ELISA compared with the use of the chromogenic substrate tetramethylbenzidine (TMB). On the other hand, with alkaline phosphatase as the indicator enzyme a pronounced improvement in assay performance was noted using the fluorogenic substrate Attophos compared with the chromogenic substrate p-nitrophenylphosphate. CONCLUSIONS: The detection system exhibiting the best characteristics with respect to cost, ease of use and overall performance in the detection of E. coli O157 in enrichment cultures from a variety of solid foods was based on the use of peroxidase as the indicator enzyme with the chromogenic substrate TMB. SIGNIFICANCE AND IMPACT OF THE STUDY: The polymyxin-ELISA provides a rapid, simple and inexpensive assay system for the detection of E. coli O157 in foods.
Explore the source record for details and available documents.
Cerebral aspergillosis carries a high mortality in immunocompromised patients. However, favorable outcome can be achieved by the prolonged use of antifungal agents and the maintenance of adequate drug levels. The authors report a 2-year-old girl who developed an aspergillus brain abscess during treatment for acute lymphoblastic leukemia. Predisposing factors for the fungal infection and details of the antifungal therapy are described. Prolonged treatment with AmBisome and 5-flucytosine successfully eradicated the lesion, but the girl's antileukemic therapy was compromised due to the infection. She developed a central nervous system and bone marrow relapse 9 and 15 months, respectively, after the initial presentation. The report emphasizes the need for further consideration of effective, long-term antifungal prophylaxis and a careful balance between aggressive treatment for severe infection and antileukemic therapy.
Weekly fasting serum calcitonin levels and biochemical indices of bone metabolism were measured in 13 postmenopausal women being given hormone replacement therapy over a period of 8 weeks. All of the biochemical indices except urinary hydroxyproline creatinine ratios fell significantly, indicating that the treatments were effective in reducing bone turnover. Calcitonin levels fell significantly and, within the individual, levels were positively correlated with adjusted calcium levels. These findings do not support the theory that estrogen conserves bone by stimulating calcitonin secretion.
Various biochemical aspects of calcium metabolism were studied serially in 32 post-menopausal patients treated with subdermal implants of oestrogen, either alone or in combination with testosterone. Significant reductions in serum calcium, serum phosphate, the renal phosphate threshold (TmPO4) and the urinary calcium/creatinine ratio were observed for periods of up to 6 mth in both treatment groups as compared with baseline. The findings suggest that oestrogen replacement therapy by subdermal implant is effective in reversing the characteristic alterations in calcium metabolism which occur in the post-menopausal patient. The addition of testosterone does not appear to confer any additional benefit with respect to the parameters assessed.
Lipoprotein concentrations were measured in 31 post-menopausal women during 1 yr of treatment with Trisequens, a natural oestrogen-progestogen preparation. Serum triglyceride, high density lipoprotein and very low density lipoprotein cholesterol concentrations did not change significantly, but low density lipoprotein cholesterol concentrations fell over the first 6 mth. After 1 yr none of the lipoprotein fractions differed significantly in concentration from pre-treatment levels.
Explore the source record for details and available documents.
Fasting serum calcitonin levels were measured in 54 postmenopausal women who had for 10 years been taking part in a double blind trial to assess the effect of the synthetic oestrogen, mestranol, on postmenopausal bone loss. There were no differences in calcitonin levels between mestranol treated and placebo groups. Fifteen of the women were challenged with a calcium infusion to measure the secretory reserve of calcitonin. Oestrogen treatment did not increase the calcitonin response to calcium infusion. The three patients who exhibited the greatest responses were placebo treated. Bone density was measured by gamma-ray absorptiometry over the ten year period and the annual rate of change of bone density calculated. No correlation could be found between basal calcitonin level or calcitonin reserve and change in bone density. Our results indicate that postmenopausal osteoporosis is not caused by a deficiency of calcitonin and that the action of oestrogen therapy to prevent bone loss does not involve calcitonin.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
The synthesis of beta-lactamase in response to 2-(2'-carboxyphenyl)-benzoyl-6-aminopenicillanic acid as inducer was studied in Staphylococcus aureus. The inducer was not detectably hydrolyzed by beta-lactamase and had minimal antibacterial activity. The kinetics of induction showed a lag of 4 to 6 min in a nutrient broth medium and 8 to 12 min in a defined medium, followed by constant differential rates of synthesis of beta-lactamase. The differential rate of beta-lactamase synthesis in nutrient broth was unaltered by supplementing the medium with glucose, galactose, lactose, arabinose, glycerol, or sucrose. Variations in the partial pressure of oxygen did not alter the differential rate of synthesis of beta-lactamase over the range 18 to 50% oxygen in nitrogen. Even when the rate of growth was considerably reduced by high-oxygen tension, the differential rate of synthesis of the enzyme remained the same. The differential rate of beta-lactamase synthesis at low inducer concentration increased after a shift down in growth rate. The effect was observed with several inducers and under different nutritional conditions, but was always preceded by a change in growth rate. It is suggested that the change in growth rate itself causes the increase in differential rate of beta-lactamase synthesis.
Explore the source record for details and available documents.