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Biomedical subjects

W S Watson

Publications and source records attributed to W S Watson.

At least 55 records · Page 3Linked to original sources
PubMed1986

Food iron and lead absorption in humans.

Food iron and lead absorption were measured simultaneously in 28 subjects by extrinsically labeling three consecutive meals with the radioactive tracers, iron 59-sulfate and lead 203-chloride. Absorption was measured directly in all subjects by whole-body counting and indirectly in 15 subjects by assessing subsequent levels of tracer in blood. Iron status of the subjects ranged from iron deficient to replete, thus providing a wide range of iron absorption. Statistically significant positive correlations were obtained between food-iron and lead absorption measured by whole-body counting and also between the tracer levels of iron and lead in the blood. However, the correlation between the absorption of the two elements was not strong, as evidenced by the fact that only 50% of the subjects who hyperabsorbed iron also hyperabsorbed lead.

Administration, Oral↗
PubMed1985

Endocrine studies in cyanotic congenital heart disease.

Seven male patients with cyanotic congenital heart disease were studied. Serum testosterone, androstenedione, dehydroepiandrosterone, thyroxine and triiodothyronine levels did not differ significantly from control values. Thyroid stimulating hormone and prolactin responses to injected thyrotrophin releasing hormone were normal. Impaired gonadotrophin responses to injected gonadotrophin releasing hormone were noted in two patients. The hypothalmic-pituitary-testicular axis appears to be better preserved in cyanotic congenital heart disease than in chronic obstructive airways disease and restrictive lung disease for a similar degree of hypoxia. Possible explanations are discussed.

Adolescent↗
PubMed1984

Kinetics of lead following intravenous administration in man.

Whole body retention of lead (Pb) and lead kinetics in blood, urine and faeces were determined over 2 weeks following i.v. administration of 203Pb-labelled chloride to 2 subjects. Pb was retained with a biological half-life of 73 days (mean). After day 1 Pb excreted in urine and faeces remained fairly constant at 1% and 0.3% of administered dose, respectively. There was a daily loss of 0.5% by other routes. There was a rapid clearance of isotope from plasma with a half-life of 1 min (mean). At 60 min 45% of the administered dose was in erythrocytes; this changed little over the 2 weeks.

Adult↗
PubMed1984

Patient-initiated autonomous pacemaker tachycardia.

Multiparameter programmable DDD pacemakers are said to have an uncountable number of possible parameter combinations. It is probable that a number of these combinations, particularly when triggered by one or more critically timed native events, will result in bizarre and unanticipated rhythms sustained entirely within the timing circuit of the pulse generator. We report the occurrence and analysis of one such rhythm termed a sustained autonomous pacemaker tachycardia. In this rhythm, both atrial and ventricular outputs occur at the maximum tracking rate of the pacemaker with an apparently shortened AV interval. Once initiated, the ability to sustain the tachycardia requires that the maximum tracking rate interval exceed the atrial escape interval. It will then continue until the pulse generator is programmed to parameters that alter this critical timing or a properly timed ventricular sensed event occurs. It is anticipated that this will be only one of many similar rhythms encountered in patients treated with complex devices from all the manufacturers. In the future, once such a rhythm is noted and its mechanism identified, modifications of the basic circuit design will allow these parameters to be used without danger to the patient and without having to limit the options of the device.

Bradycardia↗
PubMed1984

Sex hormone suppression and sexual impotence in hypoxic pulmonary fibrosis.

Eight men with hypoxia associated with idiopathic pulmonary fibrosis were studied. Serum testosterone concentrations were low in two subjects and fell to subnormal levels in two others as the clinical condition and arterial oxygen tension deteriorated. There was a significant correlation between serum testosterone concentrations and arterial oxygen tensions (p less than 0.05). Three patients showed evidence of suppression of luteinising hormone secretion at the pituitary level. Only occasional abnormalities of thyroid and prolactin concentrations were noted. Most of the men suffered from organic sexual impotence, which is considered to be due at least in part to endocrine disturbance. These findings are similar to observations in patients with hypoxic chronic obstructive airways disease and support the hypothesis that hypoxia of lung disease suppresses the hypothalamo-pituitary-testicular axis.

Adult↗
PubMed1984

The effect of acute alcohol withdrawal on the serum potassium and total body potassium in heavy drinkers.

In a group of 20 patients with heavy alcohol intake a relation was found between withdrawal symptoms and fall in serum potassium. Total body potassium (TBK) was measured in all subjects and was lower in the group of subjects who displayed symptoms than in the group who did not. The subgroup of the four most severe reactors had a mean TBK value significantly less than the 'non-reactor' group. The minimum serum potassium levels observed for all subjects in the four day period following alcohol withdrawal correlated with their TBK values. We suggest that the mechanism for the serum potassium fall might be overactivity of the Na-K pump caused by ethanol consumption. There was also an association between withdrawal reaction and abnormal liver function and a transient rise in serum phosphate in the more severely reacting subjects.

Adenosine Triphosphatases↗
PubMed1983

Malabsorption of vitamin B12 and intrinsic factor secretion during biguanide therapy.

In a survey of 46 randomly selected diabetic patients on biguanide therapy, 30% had malabsorption of vitamin B12. Withdrawal of the drug resulted in normal absorption in only half of those with malabsorption. In most patients with persistent malabsorption, the results of absorption tests with exogenous intrinsic factor suggested the diagnosis of coincidental intrinsic factor deficiency. Further considerations, however, led to the concept that biguanides can induce malabsorption by two different mechanisms. One of these is temporary and unrelated to intrinsic factor secretion and the other is permanent and mediated by depression of intrinsic factor secretion.

Adult↗
PubMed1983

A fast method of measuring vitamin B12 absorption using a whole-body counter.

The conventional method of measuring vitamin B12 absorption using a whole-body counter normally involves a delay of fourteen days before complete faecal excretion of unabsorbed B12 tracer can be assumed. A modified technique has been used which reduces the delay to four days. A non-absorbable tracer, 51Cr-chromic chloride, was administered firstly with 58Co-labelled vitamin B12 and then three hours later with 57Co-labelled vitamin B12 and then three hours later with 57Co-labelled vitamin B12 plus 50 mg hog intrinsic factor which normalises B12 malabsorption in patients with pernicious anaemia. Three days later, the residual whole-body activities of the three radionuclides were measured. The retention of 51Cr indicated the efficiency of faecal excretion of unabsorbed B12 tracer and could be used to quantify vitamin B12 absorption before complete excretion of unabsorbed B12 tracer. Vitamin B12 absorption values were measured at four days by this technique and compared with the corresponding values at fourteen days in 38 tests on 33 subjects, 16 of whom had pernicious anaemia. Excellent correlations between the results obtained at four and 14 days were obtained for both B12 tracers.

Anemia, Pernicious↗
PubMed1983

Endocrine and metabolic studies in unstable cor pulmonale.

Serum testosterone, follicle-stimulating hormone, luteinising hormone, and dihydro-epiandrosterone concentrations rose significantly in seven men studied during recovery from a severe exacerbation of chronic obstructive airways disease. Urinary 17-ketosteroids also rose significantly though serum androstenedione and prolactin concentrations did not. Our findings suggest that hypoxia in this condition suppresses the hypothalamus or pituitary or both and that such suppression is reversible. In view of previous reports of increase in total body potassium and intracellular water with recovery from cor pulmonale, we also carried out metabolic studies on our patients. Low body potassium concentrations in cor pulmonale fell further with recovery, in part reflecting a fall in lean body tissue. Intracellular water appeared to increase on recovery despite a fall in other lean body mass indices (the simplest and most reliable being skinfold thickness). We suspect this result to be spurious and due to problems with equilibration in isotope dilution. Alternatively it may reflect waterlogging of cells. A false figure for intracellular water could be responsible for an unexpectedly low estimated intracellular potassium concentration on recovery. Our results cast doubt on isotope dilution methods for measuring body water compartments in disease states likely to cause changes in cell permeability.

17-Ketosteroids↗
PubMed1982

The effect of megadose ascorbic acid ingestion on the absorption and retention of vitamin B12 in man.

Radiotracer B12 analogues, hydroxy- and cyano-cobalamin have been used to study the effects of megadose L-ascorbic acid (vitamin C) ingestion on vitamin B12 metabolism in man. By employing whole body counter techniques it has been shown that, while ascorbic acid can partially inactivate both the important dietary analogue, hydroxycobalamin, and the gastric secretion, intrinsic factor which is essential for B12 absorption, the rapid binding of the B12 analogue to intrinsic factor protects the hydroxycobalamin from attack. As a result, the absorption of hydroxcobalamin is unaffected by the simultaneous ingestion of 1 g ascorbic acid. The absorption of cyanocobalamin, the most stable analogue but not found in quantity in the diet, is slightly increased by ascorbic acid. Whole body retention studies on normal subjects ingesting 2 g ascorbic acid per day show no significant evidence of in vivo destruction of body B12 stores.

Anemia, Pernicious↗
PubMed1981

Hypothalamic-pituitary dysfunction in respiratory hypoxia.

Eight hypoxic male patients with stable chronic obstructive airways disease were submitted for combined anterior pituitary function testing. All subjects showed normal growth hormone and essentially normal cortisol responses to adequate hypoglycaemia, two subjects showed delayed responses of thyroid stimulating hormone to administered thyrotrophin releasing hormone and all had basal prolactin levels within normal limits. Basal levels of luteinising hormone were significantly lower than in the group of age-matched controls (p less than 0.02) but there was a normal increment after the injection of gonadotrophin releasing hormone. Basal levels of follicle stimulating hormone were significantly lower than in the controls (p less than 0.01), and there was also a reduced response from the pituitary after injection of gonadotrophin releasing hormone (p less than 0.01). Resting levels of the thyroid hormones thyroxine and tri-iodothyronine were normal while the expected subnormal testosterone level was observed (p less than 0.05). These results show that hypoxia can produce abnormalities of hypothalamic-pituitary function and that these are primarily located in the hypothalamic-pituitary-testicular axis.

Adult↗
PubMed1980

Body composition in cachexia resulting from malignant and non-malignant diseases.

The body composition of 23 patients with cachexia resulting from malignant or benign inflammatory disease was studied. Skinfold thickness and radioisotope tracer measurements enabled us to estimate total body fat, lean body mass, the ratio of fat loss to lean body loss, erythrocyte and plasma volumes, total body water, extra-, and intracellular water volumes, total body potassium, and intracellular potassium concentration. The total body fat and lean body mass information suggests that the body composition in cancerous cachexia differs from that in cachexia caused by benign inflammatory disease, in that lean tissue appears to be better conserved in the former. The radioactive tracer studies showed that the cachectic patients were anemic, potassium-deficient, and overhydrated; however, fluid partitioning into extra- and intracellular compartments was normal.

Adolescent↗