Design of the Intravenous Magnesium Efficacy in Acute Stroke (IMAGES) trial [ISRCTN19943732]

The Intravenous Magnesium Efficacy in Acute Stroke (IMAGES) trial is a multicentre,randomised, placebo-controlled trial of magnesium sulphate (MgSO₄) funded by the UK Medical Research Council. When complete, it will be the largest single neuroprotective study undertaken to date. Conscious patients presenting within 12 h of acute stroke with limb weakness are eligible. The primary outcome measure is combined death and disability as measured using the Barthel Index at 90-day follow up. By randomizing 2700 patients, the study will have 84% power to detect a 5.5% absolute reduction in the primary end-point. By April 2000, 86 centres were participating, with representation in Canada, USA, Europe, South America, Singapore and Australia. So far, 1206 patients have been randomised, of whom 37% were treated within 6 h. Overall 3-month mortality was 20% and the primary outcome event rate was 43%. The study is ongoing and centres worldwide are encouraged to participate.     

THE INFLUENCE OF SODIUM, POTASSIUM AND LANTHANUM ON AMINO ACID RELEASE FROM SPINAL–MEDULLARY SYNAPTOSOMES

Abstract— The effects of electrical pulses and raised potassium on glycolysis and the release of the putative transmitter amino acids glutamate, aspartate, glycine and GABA from spinal medullary synaptosomes is studied and compared with effects on glutamine, alanine and serine. The actions of ouabain, p -hydroxymercuribenzoate ( p -HMB), lanthanum chloride and lowered sodium levels on the release of all the amino acids is examined. All agents caused a change in the pattern of release of the amino acids, mostly, producing an increase, but only lanthanum, p -HMB and lowered sodium prevented the stimulus-induced release.     

Vibrios in the Louisiana gulf coast environment

A polyphasic approach, using bacteriological, immunological, and molecular biological techniques was used to elucidate the distribution of pathogenicVibrio species in the Louisiana coastal environment. A variety ofVibrio species pathogenic for man, includingV. cholerae, V. parahaemolyticus, V. fluvialis, andV. vulnificus, were found to be ubiquitous in Louisiana.Vibrio species monitored were shown to fluctuate in response to environmental factors of temperature, salinity, and nutrient level, and to vary independently of fecal coliform counts. A comprehensive serological screening system, based on species specific H antigens, was developed to identify pathogenicVibrio sp. 1 step after primary isolation.Vibrio sp. were correctly identified with accuracies ranging from 93–100%, depending on the specific H antiserum. Over 2,500V. cholerae isolates were rapidly screened for production of cholera toxin by DNA hybridization of specific toxin gene probes to colonies inoculated on nitrocellulose filter paper. The toxin gene probes, together with O antigen analysis, revealed that enterotoxigenicV. cholerae 01 serovars were recovered only from sewage stations or human disease, whereas enterotoxigenicV. cholerae non 01 serovars were recovered from environmental samples in addition to clinical and sewage samples. The results of this study indicate that techniques of immunology and molecular biology are very valuable supplements to conventional bacteriological techniques in studying the epidemiology and ecology of pathogenicVibrio sp.     

Trypanosoma musculi: Passive hemagglutination technique to measure antibody in mice

A passive hemagglutination assay was developed to measure Trypanosoma musculi-specific antibody in mice. Indicator-erythrocyte donor mice received 550 rad ⁶⁰Co 24 hr before intraperitoneal injection of 3 × 10⁴T. musculi. T. musculi antigen-coated erythrocytes were obtained from these mice on Day 9 postinfection. T. musculi antigen-coated erythrocytes obtained in this manner were used as indicator erythrocytes in a passive hemagglutination procedure. Serum from hyperimmunized mice (three consecutive infections at 21-day intervals) gave titers as high as 1:1024. Titers of 1:256 and 1:512 were obtained from singly infected mice on Days 18 and 28 postinfection, respectively. In marked contrast, nude mice infected with T. musculi did not produce a detectable agglutinating antibody response. Erythrocytes obtained from either irradiated (550 rad ⁶⁰Co) uninfected mice, nonirradiated infected mice, or normal mice did not agglutinate when combined with any of the sera tested. These data suggest the usefulness of this passive hemagglutination assay for the measurement of antibody to T. musculi in the serum of infected mice.