Epidemiology of potential association between L-tryptophan ingestion and eosinophilia-myalgia syndrome

This article examines the methodology of the epidemiological studies of the association between L-tryptophan and eosinophilia-myalgia syndrome (EMS) and evaluates the validity of the conclusions from these studies. In the initial case-control studies of L-tryptophantryptophan and EMS there were a variety of methodological problems, including different sources and different exclusion criteria for cases and controls, which could have resulted in selection bias, as well as problems with information bias and confounding. The studies of manufacturer and brand also had similar potential for bias. The L-tryptophan-EMS association is based on two small studies that had important methodological inadequacies. Subsequent studies of brand of L-tryptophan also contained errors in design, which may have produced biased results and call the conclusions into question. The cause of eosinophilia-myalgia syndrome remains unknown.     

Serological characterisation and antimicrobial susceptibility of Actinobacillus pleuropneumoniae strains isolated from pigs in Spain

Seventy-one isolates of Actinobacillus pleuropneumoniae isolated from the lungs of pigs in outbreaks of pleuropneumonia in Spain were serotyped by indirect haemagglutination. Serotype 4 (42.2 per cent), serotype 7 (22.5 per cent) and serotype 2 (12.8 per cent) were predominant, whereas serotypes 1, 3, 6, 8, 9, 12 and untypable isolates were present only in small numbers. Serotypes 1, 2, 4 and 7 originated mainly from cases of acute pleuropneumonia, whereas serotypes 3, 6, 8, 9 and 12 were associated with chronically infected herds. The susceptibility of the isolates to 20 antimicrobial agents was determined by agar disc diffusion. Most were susceptible to cefuroxime, cefaclor, cefazolin, kanamycin, tobramycin, gentamicin, oxolinic acid, ciprofloxacin, enoxacin, thiamphenicol, colistin and trimethoprim/sulphamethoxazole. Marked resistance was found with amoxicillin, ticarcillin, oxytetracycline, doxycycline and metronidazole. Rifampicin, fosfomycin and tiamulin were the agents most effective against the isolates tested.     

A second-generation interactive classroom television system for the partially sighted

This paper describes the various parts of a new interactive classroom television system (ICTS) that is being used by partially sighted elementary school children. This ICTS permits children to view one of seven separately controlled TV screens and thereby be in continuous visual communication with their teacher, classmates, and classroom. Comments are made on the advantages of educating partially sighted children separately from normally sighted children.     

Spatiotemporal dynamics of clotting and pattern formation in human blood

We examined the spatial dynamics of in vitro clot growth in human blood and plasma and found that initially, a clot grows at a constant speed, then abruptly stops and becomes surrounded by an 'inhibition zone' in which coagulation is strongly suppressed. We also observed the formation of 'stratified structures' (target patterns) in which solid layers alternated with liquid plasma. These and other spatial regimes of clotting are explained in terms of two interacting concentration waves propagating without attenuation. The experimental results are consistent with a hypothesis that blood is a bi-excitable medium, a new type of excitable medium.     

No association between the 20210 G/A prothrombin gene mutation and premature coronary artery disease

The 20210 G/A prothrombin gene mutation is associated with an increased risk of venous thrombosis but whether there is an association of the mutation with premature coronary artery disease and acute myocardial infarction remains unclear. To further assess the role of the G/A genotype as a risk factor for arterial vascular disease, we performed a case-control study of 644 patients aged less than 50 years with angiographically proven coronary artery disease, 402 of whom had myocardial infarction, and 679 unrelated healthy control subjects aged less than 50 years, randomly selected from the electoral roll. The prevalence of the G/A genotype was 2.5% in patients with coronary artery disease, and 3.2% in control subjects (odds ratio 0.8; 95% confidence interval 0.35 to 1.83). The mutation was not more frequent among patients with a history of myocardial infarction (2.2%, odds ratio 0.7; 95% confidence interval 0.27 to 2.05), and there was no evidence of an interaction between the prothrombin mutation and conventional cardiovascular disease risk factors. There was no association between genotype and extent of angiographic coronary artery disease (p=0.73). We conclude that the 20210 G/A prothrombin gene mutation is not a major risk factor for premature coronary artery disease in our predominantly Caucasian Australian population.     

Separation of rotenoids by high-pressure liquid chromatography

The external auditory canal is self-cleaning. Excessive cerumen accumulation usually results from misguided attempts to remove wax and may go unnoticed until a hearing loss occurs. Mechanical removal of the wax or use of a ceruminolytic agent to soften it is recommended--irrigation may contaminate the middle ear space.