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Biomedical subjects

W S Watson

Publications and source records attributed to W S Watson.

At least 37 records · Page 2Linked to original sources
PubMed1996

The measurement of radioactivity in people living near the Dounreay Nuclear Establishment, caithness, scotland.

In 1986, a statistically significant excess of leukaemia was reported in young people living near the Dounreay Nuclear Establishment in northern Scotland. The committee on Medical Aspects of Radiation in the Environment (COMARF) confirmed this finding and concluded that, based on conventional dose and risk estimates, the radioactive discharges from the plant could not be held responsible. However, COMARF, recognizing the uncertainties involved in the dose and risk calculations, recommended that levels of radioactivity should be measured in the general population living near the plant. Alpha-emitting contamination has been measured by urinary 239Pu analysis and 241Am in-vivo skull measurements in 66 subjects associated with the Dounreay area and in 42 subjects living remote from reprocessing plants. Whole-body counting was employed to check for gamma ray-emitting contamination. Urinary 90Sr and chromosome abnormality analyses were also carried out on subsets of the study group. No significant inter-group differences for measurements of contamination were demonstrated for groups of leukaemia cases, siblings, parents, matched local controls and controls living remote from reprocessing plants. The findings suggest that it is unlikely that the observed increased incidence in leukaemia is due to the single factor of personal radioactive contamination from the Dounreay Nuclear Establishment.

Adolescent↗
PubMed1994

Relationship between weight loss, reduction of body cell mass and inflammatory response in patients with cancer.

Reduced food intake is a major cause of continuing weight loss in patients with cancer. Previous work has suggested that an ongoing inflammatory response may also contribute to weight loss and alter the nature of body tissue loss. To examine this, body cell mass was estimated using measurements of total body potassium (TBK) in 31 patients with gastrointestinal cancer and weight loss with or without an inflammatory response (C-reactive protein level above 5 mg/l). Albumin levels, total body water and 24-h urinary creatinine clearance were also measured. When measured TBK was expressed as a percentage of predicted normal values there was a significant reduction in TBK for patients with an inflammatory response compared with that of those without (P = 0.04). However, when a different prediction equation for TBK was used this difference was not significant (P = 0.29). Therefore, it remains uncertain whether an ongoing inflammatory response in patients with cancer and weight loss contributes to loss of body cell mass.

Aged↗
PubMed1994

Effect of megestrol acetate on weight loss, body composition and blood screen of gastrointestinal cancer patients.

Reduced food intake is probably the major cause of continuing weight loss in cancer patients. Therefore, agents which stimulate food intake may be of significant benefit to such patients. To examine this, a randomized double-blind placebo controlled study of megestrol acetate was carried out. 38 gastrointestinal cancer patients with weight loss (8-43% of pre-illness stable weight) were entered into the study. 26 were evaluable at 6 weeks and 21 at 12 weeks. Clinical details, serum biochemistry and haematology were examined at 6 and 12 weeks and total body water, total body potassium at 12 weeks after the baseline assessment. There was no significant weight change in either group over the 6 or 12 weeks. Furthermore, there was no significant difference in total body water, total body potassium, blood biochemistry or haematology between the groups over the study period. It does not appear that megestrol acetate at a dose of 480 mg/day results in weight gain in advanced gastrointestinal cancer patients with weight loss.

Journal Article↗
PubMed1993

Abnormal arginine-vasopressin secretion and water metabolism in patients with postviral fatigue syndrome.

Water metabolism and the responses of the neurohypophysis to changes in plasma osmolality during the water loading and water deprivation tests were studied in nine patients with postviral fatigue syndrome (PVFS) and eight age and six-matched healthy control subjects. Secretion of arginine-vasopressin (AVP) was erratic in these patients as shown by lack of correlation between serum and urine osmolality and the corresponding plasma AVP levels. Patients with PVFS had significantly low baseline arginine-vasopressin levels when compared with healthy subjects. Patients with PVFS as a group also showed evidence of increased total body water content. These results may be indicative of hypothalamic dysfunction in patients with PVFS.

Adult↗
PubMed1991

Radiological protection guidance for radioactive patients--new data for therapeutic 131I.

Patients leaving hospital after 131I treatment for thyrotoxicosis face restrictions on their contact with other members of the public. These restrictions depend on the level of residual body radioactivity which for practical purposes can be taken to be almost entirely in the thyroid gland. This study provides an appropriate data base from which to draw advice to patients consistent with current radiological protection requirements in terms of the duration of these restrictions. Thyroidal retention of 131I was measured in 77 thyrotoxic patients over a period of 1-50 days after a first therapeutic administration of the radionuclide. Mean 131I activity in the gland (+/- S.D.) at 1 day was 56.1 +/- 11.1% of the administered dose activity and thereafter retention followed a single exponential decay pattern with a mean effective half-life (+/- S.E.M.) of 6.35 +/- 0.14 days. In patients who required further 131I therapy, there was evidence that retention could be markedly reduced if there was virtual ablation of thyroid tissue. It is proposed that these retention data can be used to determine body radioactivity at any interval after the administration of 131I for treatment of thyrotoxicosis, thus obviating the need for serial measurements in every individual patient.

Adult↗
PubMed1988

The effect of the vehicle formulation on the stratum corneum penetration characteristics of clobetasol 17-propionate in vivo.

The multiple skin surface biopsy technique to measure stratum corneum (SC) penetration characteristics in vivo has been more accurately quantified and used to provide information on the kinetics of transfer of a topical steroid through the SC. Radiolabelled clobetasol 17-propionate formulated in two different vehicles, consisting primarily of dibutyl adipate or of propylene glycol, was applied and the penetration characteristics compared. Using exponential expressions for radioactivity in skin surface biopsies as a function of SC depth, and total SC radioactivity as a function of time, a mathematical model was developed to calculate the rate of loss of steroid through superficial shedding and the rate of transfer of steroid from the SC into the epidermis. When a topical steroid was applied for 8 h under gauze occlusion, over 80% was recovered from the gauze.

Adult↗
PubMed1988

The lateral spread of clobetasol 17-propionate in the stratum corneum in vivo.

Radiolabelled clobetasol 17-propionate in two different bases, propylene glycol (PG) and di-n-butyl adipate (BA), was applied to the backs of 10 normal male volunteers, and the application sites protected. After 8 h samples of stratum corneum (SC) were taken from the application site and an adjacent site, and the level of steroid measured. At the application site there were higher concentrations of the PG formulation at the deeper levels of the SC. At the adjacent sites there were higher concentrations of the BA formulation at the superficial levels. The mean radioactivity at the adjacent sites expressed as a percentage of that at the corresponding application sites (+/- SEM) was 7.8 +/- 5.3% for the BA formulation and 3.0 +/- 2.9% for the PG, (P = 0.0002). Total percentage of the applied dose in the skin adjacent to the application site was 11.7 +/- 6.3% for the BA formulation and 5.3 +/- 5.7% for the PG (P less than 0.0002). Clobetasol 17-propionate, therefore, moves laterally to a greater extent in BA than in PG.

Adipates↗
PubMed1987

A simple blood sample method for measuring oral zinc absorption in clinical practice.

Tracer activity in blood 14 days after the oral ingestion of zinc-65 has been compared with zinc absorption measured by whole-body counting in 10 controls and 25 subjects with Crohn's disease. Highly significant linear correlations (P less than 0.001) were obtained between blood tracer activity and zinc absorption for both the control group (previously reported) and the Crohn's disease group, thus allowing zinc absorption to be predicted from blood tracer activity with an accuracy of +/- 7.1% for the control group, +/- 17.1% for an active Crohn's disease sub-group and +/- 18.0% for a quiescent Crohn's disease sub-group. Relative to the whole-body counting method, the prediction of zinc absorption from blood tracer activity had a sensitivity of approximately 88%, a specificity of approximately 89% and an overall performance accuracy of approximately 88%. Therefore, where whole-body counting facilities are not available, the blood tracer technique for predicting zinc absorption could be a useful alternative.

Administration, Oral↗
PubMed1987

Total body potassium measurement--the effect of fallout from Chernobyl.

As a result of fallout from the nuclear accident at Chernobyl in April 1986, the caesium radioisotopes, 134Cs and 137Cs, have been detected in man. A minor consequence of this is that total body potassium (TBK) measurements obtained from the whole body activity of 40K, a naturally occurring radioisotope of potassium, can be overestimated because of gamma spectrum overlap between 134Cs and 40K. Whole-body activities for 134Cs and 40K were measured in 18 healthy adults (13 M, 5 F) in June/July, 1986, using a whole-body counter with NaI crystal scintillation detectors. Studies using anthropometric phantoms containing known activities of the two radionuclides, allowed the contribution of 134Cs to the '40K activity' in the human subjects to be assessed. The group mean 134Cs level was 172 Bq, resulting in an average overestimate in TBK of 2.8%. It is recommended that when TBK measurements are being undertaken and 134Cs contamination is suspected, then 134Cs levels should be measured and their effect corrected for.

Accidents↗