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Biomedical subjects

D Williams

Publications and source records attributed to D Williams.

At least 577 records · Page 32Linked to original sources

Perceived exertion of professional hockey players.

18 professional hockey players were tested on the treadmill with a modified Balke procedure and also for maximum isokinetic strength with the Cybex II instrument. Immediately after each test the subject completed the Borg Scale of Perceived Exertion. The treadmill effort was perceived as being "somewhat hard work" while the maximum strength effort was considered "very light." This conflicts with previous literature. It may be that professional hockey players adapt to physical stress and do not respond perceptually to such stimuli in a typical manner.

Adult↗

Hemoglobin Riyadh-beta 0-thalassemia in an Indian family.

An Indian (Asian) patient with compound heterozygosity for Hb Riyadh and beta 0-thalassemia is described. Hb Riyadh forms about 95% of the hemoglobin present. The clinico-pathological picture is identical to that of simple beta-thalassemia trait confirming the harmless nature of the substitution beta 120(GH3) Lys leads to Asn.

Adult↗

Vehicle noise and the passenger.

Little effort has been put into studying the noise climate inside passenger vehicles. This paper shows that noise levels in motor cars and heavy goods vehicles are unacceptable to the passenger at typical cruising speeds. It is suggested that one factor responsible for this state of affairs is the lack of criteria for acceptable noise levels. Research into the subjective response to noise in motor vehicles, both on the road and in the laboratory, is described. The importance of very low frequencies is shown in determining levels of comfort, as well as the difficulties in accurately reproducing in-vehicle noise in the laboratory. A tentative criterion is given for acceptable noise levels in passenger vehicles and work is described which, it is hoped, will lead to a more precise measure of subjective rating.

Journal Article↗

Neutron uniformity studies related to clinical total body in vivo neutron activation analysis.

Methods of assessing the uniformity of thermal and fast neutron fluence in relation to total body in vivo neutron activation analysis are described. Results are presented for 14 MeV neutrons emitted by sealed tube generators housed in a massive concrete shield, representing a substantial source of neutrons degraded in energy. Optimisation of conditions for patient irradiations is discussed and it is shown that acceptable uniformity of fluence can be achieved with little or no premoderation of the incident neutrons.

Activation Analysis↗

Effects of azathioprine therapy on the MCV of patients with renal grafts: evidence for alterations in the kinetics of erythropoiesis over a prolonged period.

The changes in MCV at various times after renal transplantation were studied in a group of patients with functioning cadaveric renal grafts who had received azathioprine from the time of transplantation and in a constant dose from 2-8 weeks later. A post-transplantation increase in the MCV was seen in the majority of the cases studied and in these cases the MCV did not reach a maximum value until as long as 11-40 months after transplantation. In most cases the MCV then feel although frequently not to within the normal range and in some cases it showed further fluctuations. These data suggest gradual alterations over a period of years in the various cytokinetic changes which serve to maintain a reasonably high output of red cells from the marrow despite the cytotoxic effects of azathioprine.

Azathioprine↗

A histochemical method for the detection of metals in tissues, with reference to the use of surgical implants.

This report describes a method for the detection of metals in tissues that is suitable for a routine pathology laboratory. The method has been developed specifically for the examination of soft tissues taken at biopsy from the site of surgical implants. It involves the mineralization of organic matter in sections by sodium metasilicate and the conversion of the metals to sulphates by sulphuric acid, which are then stained by appropriate solutions. The method is described with particular reference to titanium and cobalt.

Animals↗

Symptom patterns in primary and secondary depression. A comparison of primary depressives with depressed opiate addicts, alcoholics, and schizophrenics.

The primary-secondary distinction in affective disorders has been proposed to reduce the heterogeneity of depression. An investigation of the frequency of secondary depression and its nature in depressed opiate addicts, alcoholics, and schizophrenics was undertaken. Findings show that secondary depression in ambulatory patients with other psychiatric disorders is relatively common. The sociodemographic characteristics of the secondary depressive are consistent with the population from which they derive but differ from primary depressives. The symptom patterns of secondary depressives are similar to primary depressives but are overall less severe. These findings give further support to the value of separating out secondary from primary depression in future research studies.

Adult↗

Influence of test site on ventricular fibrillation threshold.

An influence of VFT test site location on measured values of VFT was demonstrated in dogs with coronary occlusions, in dogs with localized areas of short recovery properties induced by warm thermal lesions, and with a computer simulation of fibrillation threshold. Under these experimental conditions VFT did not significantly change from control values when the measurement was made at a site distant to the lesion. Differences in the temporal relationship of time of recovery following application of VFT test stimuli to various locations are probably responsible for the observed differences in effects of lesions on VFT measured at these sites.

Animals↗

Left ventricular performance in patients with left ventricular hypertrophy caused by systemic arterial hypertension.

To assess the adaptation of the left ventricle to a chronic pressure overload we used echocardiography to study 18 patients with left ventricular hypertrophy caused by systemic arterial hypertension. Increased values for either posterior wall or interventricular septal thickness or both confirmed the presence of left ventricular hypertrophy in all patients and an increase in the average wall thickness to radius ratio was consistent with the development of concentric hypertrophy. No patient had clinical evidence of ischaemic heart disease. Ejection phase indices of left ventricular performance (mean Vcf, fractional per cent of shortening, normalised posterior wall velocity, and ejection fraction) were within the normal range in the basal state in 16 of the 18 patients. The hypothesis is advanced that patients with concentric left ventricular hypertrophy resulting from systemic arterial hypertension usually have normal left ventricular performance in the basal state because values for wall stress remain within the normal range. We conclude that the hypertrophic response to a chronic increase in systemic arterial pressure does not per se result in depression of the basal inotropic state of the left ventricle.

Adult↗

Inhibition of dopamine-induced release of growth hormone by thyrotropin-releasing hormone.

The effects of thyrotropin-releasing hormone (TRH) and dopamine (DA) on serum growth hormone (GH) levels were examined in the adolescent male baboon. Intravenously administered DA (40 microgram/kg-min-1 for 20 min) raised serum GH and glucose and lowered serum insulin concentrations but caused no increase in blood pressure. Concomitant intravenous infusion of TRH at 2 doses (96 ng/kg-min-1 and 40 microgram/kg-min-1 for 20 min) blocked the DA-induced increase in serum GH. The relatively low effective doses of TRH used to suppress the DA-induced GH increase suggest an interaction with catecholamines at the hypothalamic and/or pituitary to influence GH release.

Animals↗