Biomedical subjects

W N McDonell

Publications and source records attributed to W N McDonell.

3 recordsLinked to original sources

PubMed1979

Pulmonary function testing in horses.

Pulmonary function tests in horses are in the early stages of development and there will be a limit in the range of tests available since those requiring patient cooperation cannot be conducted in animals. Some tests such as blood gas analysis, A-aDo2 and delta Ppl measurements could presently be used to a greater extent under field conditions. Others that require expensive equipment and considerable technical assistance will be limited to the larger referral type veterinary clinics until the time is reached when there is adequate information to select those procedures that give a reasonable cost to benefit ratio to make their use more widespread.

Animals↗

PubMed1979

Radiographic evidence of impaired pulmonary function in laterally recumbent anaesthetised horses.

Studies in conscious and anaesthetised ponies demonstrated that starvation, anaesthesia and changes in body position influence the radiographic appearance of the lungs in the lateral and dorsoventral views. Radiographic appearances could not be closely correlated with blood gas values, but they suggested that the volume of the lowermost lung of the laterally recumbent animal is greatly reduced.

Anesthesia↗

PubMed1979

A precursor role for DHA in a feto-placental unit for oestrogen formation in the mare.

Plasma levels of total oestrogens and dehydroepiandrosterone (DHA) were measured by radioimmunossay in samples taken from various blood vessels in both maternal and fetal compartments in 11 Pony mates. High concentrations of oestrogens (greater than 100 ng/ml of plasma), expressed as oestrone equivalents, were found in the fetal circulation. On both the fetal and maternal sides, oestrogen concentrations were lower in blood going to than from the placenta. DHA concentrations, on the other hand, were higher in blood flowing to the placenta from the fetus. The fetal gonads were seen as the source of DHA, which was present in remarkably high concentrations (greater than 800 ng/ml of plasma) in venous samples from fetal ovaries and fetal testes. A precursor role in placental oestrogen formation is suggested for DHA secretion by the fetal gonads.

Animals↗