PubMed HealthSearch

Biomedical subjects

W Maher

Publications and source records attributed to W Maher.

6 recordsLinked to original sources

Plasmid analysis of 26 staphylococcal species by a rapid microscale technique.

OBJECTIVE: Evaluate a plasmid typing technique for a diverse group of staphylococci. DESIGN: In vitro testing on known isolates. SETTING: University hospital. INTERVENTION: The plasmid content of 195 isolates representing 26 staphylococcal species was analyzed by agarose gel electrophoresis following lysostaphin-alkaline-SDS lysis, with and without acetone treatment. RESULTS: Isolates yielded plasmid profiles with 0 to 7 extra-chromosomal bands (median, 1; 1.5); 171 (88%) had a profile with at least 1 band. Species with more than one isolate available for testing showed considerable diversity of plasmid profiles, except for Staphylococcus haemolyticus. CONCLUSIONS: The ease of the procedure and the diversity of plasmid profiles within each species examined suggests that plasmid profiling is an accessible and useful epidemiologic tool applicable to most staphylococcal species by epidemiologic units or clinical laboratories.

Bacterial Typing Techniques

Low-volume microwave digestion of marine biological tissues for the measurement of trace elements.

The use of low-volume (7 ml) Teflon vessels and microwave heating is described for the digestion of three marine biological tissues representing a mollusc, a fish and a crustacean. Freeze-dried samples (< 0.1 g dry mass) and 1 ml of nitric acid were placed in 7 ml screw-topped Teflon vessels and treated using a programmed three-stage digestion. The first two stages were kept consistent (600 W, 2 min; 0 W, 2 min) and the third stage was varied from 150 to 450 W over 15-60 min to find the optimum microwave digestion conditions. Trace elements were determined using flame atomic absorption spectrometry, or electrothermal atomic absorption spectrometry when analysing samples containing very low concentrations of cadmium. Quantitative recoveries of copper, zinc and cadmium were obtained from the five marine reference materials under the following conditions: 600 W, 2 mins; 0 W, 2 min; 450 W, 45 mins.

Animals

Hypertensive crisis induced by eating in a patient with pheochromocytoma.

Catecholamines have an important effect on the gastrointestinal tract. Patients with pheochromocytomas frequently have gastrointestinal complaints. We report a 13-year-old girl with a 250-g intra-abdominal pheochromocytoma who presented with symptoms of excessive catecholamines release and hypertensive crisis that was provoked by eating. The patient's pheochromocytoma was so large that it was palpable and compressing the greater curvature of the stomach.

Adolescent