Search PubMed⌕ Search

Biomedical subjects

A Stewart

Publications and source records attributed to A Stewart.

At least 343 records · Page 19Linked to original sources

Enhancement of renal excretion of uric acid during long-term thiazide therapy.

The effect of thiazide (hydrochlorothiazide 100 mg per day orally in two divided doses for up to 3 years) on uric acid metabolism was examined in 21 patients with renal stones suffering from renal hypercalciuria or absorptive hypercalciuria. Serum concentration of uric acid increased during thiazide therapy in every patient. In 12 of 21 patients, there was a transient or persistent rise in urinary uric acid of more than 50 mg per day during treatment. The mean urinary uric acid produced by thiazide was positively correlated with the change in the renal clearance of uric acid. Thus, an increase in urinary uric acid was often associated with a rise in uric acid clearance. The results suggest that thiazide may either increase the production of uric acid or decrease the extrarenal disposal of uric acid, in some patients.

Administration, Oral↗

The meaning of health: understanding functional limitations.

Results of psychometric studies of 14 questionnaire items commonly used to define chronic functional limitations due to poor health are reported. Self-administered questionnaires were used to gather data from 1,209 persons 14 years of age and older. Data were used to study: scalability of items; test-retest reliability of alternate forms of scales; validity of scales in relation to 13 health status variables and age; and precision of scales in detecting differences in health. Three scales pertaining to chronic limitations in mobility, physical activity, and social role activity functions satisfied the criteria of scalogram analysis. Four-month test-retest reliability estimates for alternate forms were very high. Strong associations (some curvilinear) were observed among functional limitation scales, and between these scales and survey measures of physical abilities, general health perceptions, health worry/concern, chronic disease conditions, and age. Measures of physical abilities and functional limitations appeared to define opposite ends of a function-dysfunction continuum. Statistical modeling of precision indicates that, due to the skewed distribution of scores, large sample sizes would be required to detect differences in functional limitations in studies using only a posttest.

Activities of Daily Living↗

Metabolic effects of parathyroidectomy in asymptomatic primary hyperparathyroidism.

Effects of parathyroidectomy on parathyroid function and calcium (Ca) metabolism were carefully evaluated in 6 patients with primary hyperparathyroidism without symptoms normally attributed to the disease and in 7 with bone disease or nephrolithiasis. Before parathyroidectomy, both groups of patients demonstrated evidence of the sequelae of parathyroid hormone (PTH) excess, since they presented one or more of the following features: low bone density by 125I-photon absorption, hypercalciuria (urinary Ca greater than 200 mg/day on an intake of 400 mg/day), negative Ca balance (absorbed Ca less than urinary Ca), elevated fasting urinary Ca greater than 0.2 mg/mg creatinine for a night-time sample after a 6-hour fast), and decreased renal function (creatinine clearance of less than 65 ml/min). Following parathyroidectomy, most of these deleterious effects were reversed commensurate with the return of immunoreactive serum PTH, serum Ca, and urinary cyclic AMP toward normal. These quantitative non-invasive techniques may be useful for the initial evaluation and follow-up of patients with asymptomatic primary hyperparathyroidism.

Adult↗

A comparison of two bipolar exercise electrocardiographic leads to lead V5.

ST-segment depression and slope were compared in three lead systems (V5, CC5, and CM5) and in two groups of patients using both visual analysis of electrocardiographic paper and computerized techniques. Bipolar lead CC5 was found to be comparable to lead V5 when visual analysis of electrocardiographic recordings was utilized. Bipolar lead CM5 was found not to be comparable to lead V5 and to be less sensitive if classic criteria for slope were used. The technique of computerized analysis mad measurements of slope and amplitude to a reproducible level not possible with the standard technique. Statistically significant differences were found between the exercise electrocardiographic leads utilizing computerized electrocardiographic analysis . We conclude that computerized techniques of electrocardiographic analysis require new criteria for defining an abnormal repolarization response. The criteria must be specific for different electrocardiographic leads if the repolarization changes in these leads are to have comparable diagnostic significance.

Adult↗

Photon absorptiometric analysis of bone density in primary hyperparathyroidism.

The density of bone in the distal third of the radius was measured in 13 men and 17 women with primary hyperparathyroidism. The bone density was significantly reduced (as compared to age-matched controls) in 7 of 11 postmenopausal women. However, it was reduced in only 2 of 13 men and in 1 of 6 premenopausal women. Thus, most of the postmenopausal women with primary hyperparathyroidism had low bone density, whereas most men and premenopausal women with this condition had normal bone density. The results support the conclusion that oestrogen deficiency may contribute to the development of bone disease by sensitising bone to the action of parathyroid hormone.

Adult↗

Infant leukaemias and cot deaths.

Infant leukaemias differ from childhood leukaemias in ways which suggest that when haemopoietic neoplasms combine fetal origins with rapid growth rates they prevent normal development of the reticuloendothelial system and thus cause the sudden death of apparently healthy babies (stillbirths or cot deaths). Cot deaths are commoner in boys and have a peak incidence during the first half of infancy-that is, during the period most affected by the switch from passive to active immunity. Babies born from July to December, who are intensively exposed to winter conditions form 1 to 5 months of age, are also at special risk. During this period more girls and more children born form January to June die of leukaemia; and within three months of birth an exceptionally high ratio of myeloid to lymphatic leukaemias has been replaced by a low ratio, which persists throughout childhood.

Age Factors↗

Parents of babies of very low birth weight: long-term follow-up.

On hundred and sixty babies of birth weight less than or equal to 1500 g who survived after perinatal intensive care have been followed up and observations have been made on their parents. In spite of attempts to minimize maternal separation and the distressing aspects of the birth and management of a baby of very low birth weight, an emotional crisis was observed in the mothers which was not fully resolved until the parents had been looking after the baby at home. The duration and degree of the crisis varied but the mothers who received sympathy and support from the baby's father appeared to have least difficulty. A rigid maternal personality and circumstances surrounding the birth which predisposed to feelings of failure and guilt appeared to prolong the crisis. Nevertheless, most of these parents subsequently formed satisfactory relationships with their children, although they tended to be over-protective and anxious. Failure to establish an adequate relationship was rare and occurred only among mothers with personality or psychiatric disorders. Although serious behaviour disorders among the children were rare, more children than would be expected were mildly over-dependent, shy and anxious at follow-up.

Birth Weight↗