G C Donaldson — Page 3

PubMed1985

A method to determine significant levels of immunoglobulin G to Aspergillus fumigatus antigens in an ELISA system and a comparison with counterimmunoelectrophoresis and double diffusion techniques.

A method is described which assesses results obtained from an ELISA system for the determination of human serum levels of IgG class antibodies to Aspergillus fumigatus. The method is used to discriminate positive from negative samples, and significant antibody activity may be reported to the clinician, relative to a reference positive control serum monitored simultaneously under the same test conditions. Antibody content is expressed as the absorbance of a certain dilution of serum. Duplicate samples were analysed at a single serum dilution and their absorbtion values obtained from a semi-automated ELISA microplate reader. These were entered into a computer programmed to convert the data into units on a logarithmic scale. In parallel experiments, ELISA results were compared with those obtained by the techniques of counterimmunoelectrophoresis and double diffusion which measure precipitating antibody of all classes. A relatively good degree of correlation between tests was found only among sera with a high level of antibody.

Antibodies, Fungal↗

PubMedDate not supplied

Cardiovascular responses to heat stress and their adverse consequences in healthy and vulnerable human populations.

This paper reviews the basic thermoregulatory physiology of healthy people in relation to hazards from external heat stress and internal heat loads generated by physical exercise or radiofrequency (RF) radiation. In addition, members of the population are identified who may be particularly vulnerable to the effects of heat stress. These data are examined in relation to current international guidance on occupational and public exposure to RF radiation. When body temperature rises, heat balance of the body is normally restored by increased blood flow to the skin and by sweating. These responses increase the work of the heart and cause loss of salt and water from the body. They impair working efficiency and can overload the heart and cause haemoconcentration, which can lead to coronary and cerebral thrombosis, particularly in elderly people with atheromatous arteries. These adverse effects of thermoregulatory adjustments occur with even mild heat loads and account for the great majority of heat-related illness and death. They are, therefore, particularly relevant to determination of safe population exposures to additional sources of heat stress. It is concluded that exposure to RF levels currently recommended as safe for the general population, equivalent to heat loads of about one tenth basal metabolic rate, could continue to be regarded as trivial in this context, but that prolonged exposures of the general population to RF levels higher than that could not be regarded as safe in all circumstances.

Adaptation, Physiological↗