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Biomedical subjects

M Hayes

Publications and source records attributed to M Hayes.

At least 127 records · Page 7Linked to original sources
PubMed1983

Plasma prednisolone studies in rheumatic patients.

Prednisolone concentration in plasma after a daily maintenance steroid dose was monitored in 83 patients with rheumatic diseases. Although no restrictions were imposed on the intake of food or drink, plasma drug levels tended to peak at 1 h after the ingestion of the standard tablets, whereas intestinal absorption of the enteric-coated preparation was found to be most unpredictable. A profound individual variation was observed in plasma prednisolone concentrations, and neither total nor unbound drug levels showed any consistent relationship with the size of the prednisolone dose or the control of the disease activity. The basal cortisol production was suppressed in one-third of the patients. There is no support from this study for the concept of an 'optimum therapeutic range' of plasma prednisolone for the treatment of rheumatic disease.

Adult↗
PubMed1983

Effects of age, gender, and cigarette smoking on human immunoregulatory T-cell subsets: establishment of normal ranges and comparison with patients with colorectal cancer and multiple sclerosis.

Normal ranges for peripheral circulating mature functional T cells (OKT3+), T helper-inducer cells (OKT4+), and T cytotoxic-suppressor cells (OKT8+) were determined in 161 normal male and female volunteers. Children between 5 and 15 years of age showed higher circulating OKT3+ cell numbers than adults, and in male children the circulating OKT4+ cell number was also higher. In adults, females demonstrated higher circulating OKT4+ cell numbers than males, and smokers demonstrated higher circulating numbers of both OKT3+ and OKT4+ cells than nonsmokers. There was a significant interaction between gender and smoking, with female smokers exhibiting the highest circulating OKT3+ cell numbers. Two groups of patients entering longitudinal T-cell subset monitoring studies were compared to their appropriate normal control groups. It was found that 48% of patients with colorectal cancer were T-cell (OKT3+) lymphopenic at presentation, and that 62% had a low OKT4/OKT8 ratio. Colorectal surgery tended to correct this T-cell lymphopenia. However, only transient rises in low OKT4/OKT8 ratios were observed after surgery. Of 11 patients with multiple sclerosis in a trial of transfer factor therapy, 7 were found to have high OKT4/OKT8 ratios prior to treatment; these ratios have persisted to date during treatment.

Adolescent↗
PubMed1983

The reaction of ovine neutrophils to Histophilus ovis in relation to genital infection of rams.

Histophilus ovis was shown to be phagocytized by neutrophils when the organisms enter the lumen of the reproductive tract of the ram. The phagocytosis and destruction of H. ovis by neutrophils was demonstrated in vitro by the viable count method and by electron microscopy. It was shown that immunoglobulins and complement had no influence on the phagocytosis and destruction of H. ovis. Phagocytosis and killing of H. ovis was accomplished equally well by neutrophils from immunized and non-immunized rams. Immunized rams showed a massive infiltration of neutrophils into the walls, epithelium and lumen of their ampullae when dead H. ovis were introduced into their lumen.

Actinobacillus↗
PubMed1983

Retardation of wool growth in Merino sheep caused by bacteria.

A condition evidenced by retarded growth of wool with alteration of the yolk into a yellow, sticky, wax-like substance was investigated. The condition was associated with hyperaemia and cellular infiltration into the dermis in the affected areas. Three bacterial species, viz. Enterobacter aerogenes, E. agglomerans and Hafnia alvei, which could grow on the water-extractable component of wool-yolk, were incriminated as the cause of the condition.

Animals↗
PubMed1982

A standardised multicentre procedure for plasma gonadotrophin radioimmunoassay.

A radioimmunoassay method for the assay of luteinising hormone (LH) and follicle-stimulating hormone (FSH) in serum/plasma has been designed for use in laboratories of varying expertise in the United Kingdom. The major sources of experimental error leading to poor within-laboratory performance and between-laboratory comparability were identified: quality of tracer, use of calibration standards, and separation procedure. A simple rugged kit was designed which was extensively tested first in our laboratory and then in a small multi-centre field trial before being made available. It is now used routinely by 26 health service and research laboratories. The working range of the assays is 1-50 IU/l (LH) and 0.3-16 IU/l (FSH). The between-batch reproducibility was 5-11% (CV) over the dose range 4.8-18 IU/l (LH) and 1.6-15 IU/l (FSH).

Animals↗
PubMed1981

Prednisolone concentrations in plasma, saliva and urine.

Prednisolone was measured in plasma, saliva and urine at various times after a single dose. Peak plasma prednisolone levels were observed about 1 h after the dose. Saliva prednisolone levels were measurable for at least 3 h after dosing but showed no consistent relationship to either total or free plasma prednisolone concentrations. Unchanged prednisolone in amounts up to 14% of the dose administered was found in the 24 h urine and most of it was excreted in the first 5 h.

Adult↗
PubMed1981

Inverse relationship between onset and duration of EEG effects of six peripherally administered peptides.

Electrical activity in the rat brain after the peripheral injection of equimolar (0.1 mM) doses of Metenkephalin, Leu-enkephalin, beta-endorphin, gamma-endorphin, DSIP, and alpha-MSH was assessed by power spectral analysis. The mean onset of EEG activity for each peptide varied between 13.7 and 20.7 minutes and lasted between 27.8 and 40.8 minutes. The significant (p less than 0.001) interaction between duration and latency revealed that the longer the latency, the shorter the duration. Similar findings were observed after injection of the same peptides at a fixed dose of 80 microgram/kg body weight. Thus, the results demonstrate that peripherally injected peptides can exert EEG effects that last longer the sooner they start.

Animals↗
PubMed1981

Radionuclide angiographic correlation of the R wave, ejection fraction, and volume responses to upright bicycle exercise.

The change in the R wave and the response of the ejection fraction to upright bicycle stress testing with radionuclide angiographic studies were determined for 18 control subjects and 29 patients with coronary arterial disease (70 percent stenosis or more). In the control group, all had an increase in the ejection fraction from 64.8 +/- 7.7 to 75.7 +/- 9.4 percent with stress (P less than 0.01). All control subjects had a decrease in the R wave with exercise. In the group with coronary arterial disease, most patients had a decrease in the ejection fraction averaging from 63.5 +/- 10.9 to 58.6 +/- 12.8 percent (P less than 0.01). An appropriate response of the R wave and ejection fraction (decrease in R wave and increase in ejection fraction or increase in R wave and decrease in ejection fraction) occurred in 23 (79 percent) of 29 subjects (P less than 0.005). The sensitivity, specificity, and predictive value for the response of the ejection fraction were as follows: 83 percent (24/29); 100 percent (18/18); and 100 percent (24/24). Of the patients with coronary arterial disease and an increase in the R wave, 17 (94 percent) had multivessel disease, while six (55 percent) of 11 with a decrease in the R wave had multivessel disease (P less than 0.05). The systolic volume decreased in all control subjects by -15.9 +/- 8.6 units (P less than 0.01) and increased in most of the group with coronary arterial disease by 13.7 +/- 17.8 units (P less than 0.01) in response to stress. There were 20 of 29 patients (P less than 0.05) with an appropriate response of the R wave and systolic volume to stress (increase in R wave and systolic volume or decrease in both). The change in the R wave did not correlate with the change in the diastolic volume with stress (P greater than 0.05). Changes in the R wave with exercise correlate with the change in the ejection fraction (and hence ventricular function) and with the changes in systolic volume, which may be one of the mechanisms of the response of the R wave, suggesting that the change in the R wave is related to changes in contractility. Increase in the R wave with stress suggests multivessel coronary arterial disease.

Adult↗
PubMed1981

Effect of synthetic thyrotrophin-releasing hormone and its analogues on growth hormone secretion in the domestic fowl (Gallus domesticus).

Variations in plasma growth hormone (GH) concentrations following iv or sc administration of synthetic thyrotrophin-releasing hormone (TRH, Pyr-His-Pro-NH2) have been followed in immature and adult domestic fowl. TRH markedly stimulated GH secretion in newly hatched (1 and 2 day old) chicks and in 6-week-old cockerels but in adult male or female birds of two strains had very little effect, if any. Intravenous injection of 4 TRH analogues (Pyr-His-Mep-NH2, Pyr-Meh-Mep-NH2, Pyr-Meh-Mep-NH and Pyr-Meh-Pro-NH2) were also potent GH secretagogues in 6-week-old birds. The stimulatory effect of TRH or the TRH-analogues on GH secretion was not dose-related.

Age Factors↗
PubMed1980

Lung imaging with radioaerosols for the assessment of airway disease.

Aerosol inhalation lung scans offer distinct advantages in the evaluation of airways and the qualitative distribution of ventilation. The sensitivity in detecting mild obstructive disease is similar to that of xenon washout and both probably surpass standard pulmonary function tests that measure total rather than regional ventilation. Although imaging studies using krypton gas are ideal for assessment of rapidly ventilated space, krypton's short half-life precludes its usefulness for demonstrating air trapping. Neither 133Xe nor 81mKr gas demonstrates sites of airway abnormality as aerosol does. Aerosols are ideal for the general nuclear medicine practice in community hospitals because of their convenience, cost effectiveness, and information yield. Current technique using same-day multiple-view aerosol scans after a preliminary perfusion scan, makes use of the most logical diagnostic scheme in the vast majority of patients with chest complaints, since a normal perfusion scan often eliminates the need for a ventilation scan.

Adult↗
PubMed1979

Improved radioaerosol administration system for routine inhalation lung imaging.

An improved radioaerosol administration system has been developed to reduce the number of droplets larger than 2.0 micron in diameter which have caused abnormal hyperdeposition of inhaled aerosols in the large airways. The new system has achieved this goal by interposing a reservoir-setting bag in the aerosol delivery line between the nebulizer and the patient. The components are inexpensive, commercially available and easily assembled in any nuclear medicine service.

Adult↗