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Biomedical subjects

W H Thomson

Publications and source records attributed to W H Thomson.

At least 73 records · Page 4Linked to original sources
PubMed1985

The value of syringe shields in a nuclear medicine department.

The radiation dose to the pulp of both index fingers has been measured in a radiopharmacy supplying 11 000 patient doses a year, in a hospital dispensary (4500 doses a year) and in its injection area. Tungsten syringe shields were used for one week and not used during the other week. In the radiopharmacy and the dispensary the highest finger dose recorded was 6.8 mSv, which corresponds to an annual figure of 330 mSv. Syringe shields gave a protection factor of less than two, and the dose to the left hand was approximately half that to the right. When giving injections the corresponding weekly and annual doses were 4.6 and 220 mSv respectively. If all injections had been given by a single person the corresponding annual dose would have been 430 mSv. Using syringe shields this could be reduced by factors of at least eight for the right hand but only 1.3 for the left hand. Dose rates for unshielded syringes expressed per 10 GBq handled are similar to other data in the literature. However, syringe shields reduce the dose rates less than anticipated. Tungsten 1.94 to 3.05 mm thick would be expected to give an attenuation factor of 27 to 178.

Body Burden↗
PubMed1984

Physiological characteristics of high-ability prepubescent wrestlers.

The present study compared the physiological responses to exercise, the anaerobic fitness, and the body composition of high-ability prepubescent wrestlers and normally active boys. The wrestlers (N = 15, mean age +/- S.D. = 11.3 +/- 0.30 yr) were recruited to participate in a summer wrestling camp. Their wrestling experience averaged 3.0 +/- 1.63 yr, during which time they won 78 +/- 10.5% of the matches. The comparison boys (N = 13, 10.7 +/- 0.36 yr) were volunteers from a local Boy's Club. Each subject performed a graded treadmill exercise test (Bruce protocol) and an anaerobic cycle ergometer test. Additionally, body composition was assessed using densitometry and skinfolds. There were no differences (P greater than 0.05) between the wrestlers and the comparison subjects for age or height. The wrestlers exercised for 1.5 min longer on the treadmill and obtained a higher VO2max (54.0 +/- 1.15 ml X min-1 X kg-1, P less than 0.05) than the comparison subjects (45.6 +/- 2.10 ml X min-1 X kg-1). Also, the wrestlers had higher anaerobic test scores, greater body densities, and lower subcutaneous fat totals at all sites than the normally active boys. These data indicate that the favorable fitness and body composition scores found previously for more mature wrestlers are already present in prepubescent wrestlers.

Adipose Tissue↗
PubMed1983

Comparison of thiazides and amiloride in treatment of moderate hypertension.

The biochemical disturbance produced by thiazide diuretics and by amiloride during treatment of moderate hypertension were compared. Two parallel studies were initiated. In one 40 patients with newly diagnosed hypertension were treated with metoprolol and a diuretic, either hydrochlorothiazide or amiloride. In a second study 38 patients receiving longstanding treatment with hypotensives and thiazides either continued the treatment or replaced the thiazide with amiloride. Initial biochemical assessments were compared with those after two years in the study. In previously untreated patients, thiazide produced a significant fall in plasma potassium and hyperuricaemia that did not occur with amiloride (p less than 0.001). Those patients receiving long term treatment for their hypertension who continued to take thiazides had persistent hypokalaemia and hyperuricaemia. Substitution with amiloride corrected the hypokalaemia and serum uric acid returned toward normal ranges, but this change was not statistically significant. Patients receiving long term treatment also had impaired glucose tolerance, this remained unchanged in those receiving thiazide but was corrected in those receiving amiloride. Compared with amiloride thiazides produced undesirable but reversible biochemical changes. As control of hypertension was equally effective with both preparations, we suggest that a combination of amiloride with a beta blocker in treatment of moderate hypertension in preferred.

Adult↗
PubMed1982

The body composition and physical dimensions of 9- to 12-year-old experienced wrestlers.

Body composition and physical dimensions were compared between 23 young, experienced wrestlers (mean age +/- SE = 11.0 +/- 0.21 yr) and 23 school children (11.2 +/- 0.24 yr). The wrestlers were among the best wrestlers from local wrestling clubs and averaged 2.7 (+/- 0.27) yr of experience. They had won 72% (+/- 1.8%) of the total 75 (+/- 9.1) matches. The comparison group consisted of volunteers from local elementary schools. Standard densitometric and anthropometric techniques were used to measure the body composition and physical dimensions of each group. The wrestlers were 4 kg lighter (P less than 0.05) and had a smaller percent fat than the comparison group (13.3 +/- 0.66% and 20.0 +/- 1.13%, respectively). The weight difference between groups was due to the larger fat weight of the comparison group since lean weight differed by only 0.8 kg. Fat differences were also reflected in the larger skinfolds and "fat" circumferences of the comparison group. No group differences were noted in diameters. It is concluded that compared to other children young experienced wrestlers have similar skeletal structures and lean body weights. The comparison group possessed more body fat.

Adipose Tissue↗
PubMed1980

Effects of oestrogens on erythrocyte enzyme efflux in normal men and women.

In the normal female range for serum creatine kinase, the large diminutions associated with the reproductive period and with pregnancy are apparently related to oestrogen production. Specimens of heparinised blood from healthy men and women were stressed by chilling, and showed the predictably large efflux of erythrocyte aldolase and lactate dehydrogenase into plasma. In aliquots of the same specimens simultaneously stressed in the same way, previous substitution of the natural plasma with pregnant plasma rich in oestrogens gave a marked significant reduction in the efflux of both enzymes in women, but not in men. The significance of these findings is discussed.

Adolescent↗
PubMed1978

X-linked recessive (Duchenne) muscular dystrophy (DMD) and purine metabolism: effects of oral allopurinol and adenylate.

Data are presented which suggest that Duchenne muscular dystrophy (DMD) may have some origin in a severe deficiency of total muscle adenine nucleotides. Using double-blind techniques, this possibility was tested in 16 DMD patients by giving oral allopurinol, a synthetic inhibitor of the purine catabolic enzyme xanthine oxidase. Sublingual procaine adenylate was also briefly tested. Instances of clinical improvement quickly occurred which were statistically significant; they were accompanied by a significant increase in physical strength. These improvements have been maintained for more than 6 mo by administration of a small amount of allopurinol daily. Procaine adenylate had little effect. These results support the above view of DMD and seem to indicate that existing purines, retained and recycled after allopurinol, can sustain such improvement, and that additional adenylate is unnecessary.

Adenosine Monophosphate↗
PubMed1978

An improved method for the diagnosis of polycythaemia.

The red cell mass was measured in 44 normal subjects and showed a closer correlation with total body water or surface area than with body weight. The results obtained in a group of patients with polycythaemia, however, still overlap with the normal range. When the total number of circulating red cells is measured these patients form a group quite separate from the normals. The diagnostic value of this measurement is therefore considerably greater than results obtained with the red cell mass.

Adult↗
PubMed1977

Carrier detection in X-linked recessive (Duchenne) muscular dystrophy: pyruvate kinase isoenzymes and creatine phosphokinase in serum and blood cells.

Allosterism allows individual assay of both isoenzymes, one abundant in muscle, of pyruvate kinase (PK), recently reported superior to serum creatine phosphokinase (CPK) in detecting patients with and female carriers of X-linked recessive (Duchenne) muscular dystrophy (DMD). Extensive comparative studies did not support these findings and confirmed the marked superiority of CPK over rariants of PK or other enzymes in sensitivity, stability and convenience. Deducting the adenylate kinase increment (AKI) further refined the CPK assay, eliminating the effect of haemolysis in diagnosis and enabling studies of blood cell content. Both leucocytes and erythrocytes liberated PK and lactate dehydrogenase (LDH) after brief chilling or disruption. Only erythrocytes showed a CPK content, however, constantly adjusted to match that of serum as if by free cell membrane passage, but less accomodating to a sudden large influx of CPK than of LDH, where an apparent buffering effect could account for differences in clinical response.

Adenylate Kinase↗
PubMed1975

Studies on the carrier state in X-linked recessive (Duchenne) muscular dystrophy.

Observations in 12 normal women and 12 female carriers of X-linked recessive Duchenne muscular dystrophy (DMD), of whom 4 had symptoms and 8 had none, were compared between all 4 groups and with those in 2 DMD boys, one active and one crippled. Carrier symptoms were readily ascertained by systematic examination. Measurement of both lower legs in all 24 women showed neither calf enlargement nor asymmetry in carriers beyond normal variation. Two DMD carrier daughters were noted of the same DMD carrier mother but by different fathers. Whole body counting showed the biological half-life of previously administered 86Rb to be much reduced in DMD, but no differences were found between normal women and any group of carriers. The test is thus valueless for carrier detection, and reasons are given why it should be so. Simultaneous measurement of total body K+, with subsequent determination by isotope dilution of total body water as 3H2O space and extracellular water as NH4 82Br space, showed increased intracellular water and reduced intracellular K+ concentration in all carriers, as if due to osmotic causes, with actual loss of muscle mass and slight diminution of serum K+ in the 4 symptomatic carriers only. Because of diurnal and other variations, the means and standard deviations for six serum enzymes from six fortnightly assays in all subjects were used to measure precise individual status. Their coefficients of variation were abnormal only in symptomatic carriers and ambulant DMD, easily overtexed by even accustomed exertion. This is shown to support previous propositions on the pathogenesis of DMD and the escape of muscle cell content into the circulation.

Adolescent↗
PubMed1975

The nature of haemorrhoids.

An anatomical and clinical study aimed at uncovering factors likely to be helpful in understanding the true nature of haemorrhoids is described. The main finding was of specialized 'cushions' of submucosal tissue lining the anal canal; it is argued that piles are merely the result of their displacement.

Adolescent↗