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Biomedical subjects

W M Tunbridge

Publications and source records attributed to W M Tunbridge.

At least 37 records · Page 2Linked to original sources
PubMed1982

Age-associated change in QRS axis: intrinsic or extrinsic ageing?

Human ageing is most usefully conceptualised as an interaction between intrinsic and extrinsic processes. Comparison of age-associated trends in populations living under different environmental conditions provides a method of recognising the effects of extrinsic influences. This paper compares the age-associated trend in mean frontal plane QRS axis in the male adult population of Pukapuka with the trend observed in an age-matched sample from a British population. The Pukapukans show no rise in mean blood pressure with age and have other features placing them at low risk of coronary heart disease. Although the British population showed the shift to the left in mean QRS axis characteristic of economically advanced populations there was no change in mean QRS axis with age among the Pukapukans. The conclusion is drawn that the shift with age in QRS axis observed in advanced populations is extrinsic in origin but is not necessarily a manifestation of coronary heart disease.

Adult↗
PubMed1981

Natural history of autoimmune thyroiditis.

One hundred and sixty-three asymptomatic people with thyroid antibodies or raised serum thyrotrophin (TSH) concentrations, or both, and 209 age-matched and sex-matched controls without either marker of thyroid disorder were followed up for four years to determine the natural history of autoimmune thyroiditis. Mildly raised TSH concentrations alone and the presence of thyroid antibodies alone did not significantly increase the risk of developing overt hypothyroidism during the four years compared with the controls. Overt hypothyroidism developed at the rate of 5% a year in women who initially had both raised TSH concentrations and thyroid antibodies. Prophylactic treatment with thyroxine may be justified in women found to have both markers of impending thyroid failure. The cost effectiveness of screening the adult population remains to be evaluated.

Adult↗
PubMed1981

Low incidence of chlorpropamide-alcohol flushing in diet-treated, non-insulin-dependent diabetes.

50 diet-treated, non-insulin-dependent diabetics were tested subjectively and objectively for chlorpropamide-alcohol flushing (CPAF) with a single challenge test. Of the 12 (24%) who reported a subjective flush, 9 (18%) also flushed when a placebo was given instead of chlorpropamide, so the true incidence of chlorpropamide-alcohol flushing was 4% (1 patient was not retested with placebo). In a control group of 21 non-diabetics, 2 showed the specific CPAF phenomenon. Temperature measurement did not improve discrimination, but it did show a faster rise in facial temperature in CPAF-positive subjects than in alcohol flushers. This study does not confirm previous higher estimates of the incidence of the CPAF phenomenon in non-insulin-dependent diabetes.

Adult↗
PubMed1979

Identification in human seminal fluid of an inhibin-like factor which selectively regulates FSH secretion.

Human seminal plasma obtained by centrifugation of human semen contains a factor capable of selectively inhibiting the secretion of FSH both in vivo (reduction of the levels of FSH in rats 24 h after castration) and in vitro (reduction of the FSH released by LH-RH in rat pituitary cell culture). This effect is not due to testosterone, oestradiol-17 beta or progesterone present in the active fractions. The factor has the characteristics of a protein in that its biological activity is destroyed by heat and trypsin digestion. It does not resemble androgen-binding protein. The biological action is not completely specific for FSH as inhibition of LH can be seen with doses usually higher than those which produce inhibition of FSH alone. There is no effect on TSH or prolactin levels in vitro. The factor clearly acts on the release and synthesis of gonadotrophins by gonadotrophs but an effect on the hypothalamus is not excluded. This factor fits the definition of inhibin.

Animals↗
PubMed1978

Thyroid hormone concentrations in a large scale community survey. Effect of age, sex, illness and medication.

Total thyroid hormone concentrations have been measured in the course of a large scale community survey to determine the distribution of these variables in the normal population and to assess the effect of age, sex, previously undectected thyroid disease and medication upon these parameters. 2779 subjects were studied. Serum T4 concentrations were normally distributed. A progressive increase in T4 levels with age was noted in the males, and a smaller increase in females which was concealed by the raised T4 values secondary to oral contraceptive therapy in females under the age of 45. Serum T3 levels were also normally distributed. There was a small reduction in T3 with age in the males but this fall was not seen in the females. T3 values were relatively higher in females under the age of 45 but this increase was not noted after exclusion of subjects taking an oral contraceptive. The changes in thyroid hormone concentrations with age are relatively minor (particularly with respect to T3) in a randomly selected sample from an English town. It is suggested that the changes reported by other authors reflect the process of selection used, and the high frequency of undetected thyroid disease, other illness and medication in hospital-based communities.

Adolescent↗
PubMed1976

Information loss in limb-lead electrocardiograms compared with twelve-lead tracings in a population survey among the elderly.

A total of 235 telve-lead electrocardiogram tracings representing all those traces with positive Minnesota codings from a population sample of persons aged 65 and over were re-coded on the basis of the six limb-leads alone. The over-all loss of information amounted to about 22.3 per cent of major abnormalities, as defined, but was higher than 50 per cent for some individual abnormalities such as abnormal Q and QS waves. Possible implications of these findings are discussed.

Aged↗
PubMed1975

Bromocriptine therapy in acromegaly.

Bromocriptine (CB-154, Sandoz) has been given to 21 acromegalic patients (11 female, 10 male) for a period of 6-10 months. The mean serum growth-hormone (G.H.) levels ranged from 10 mug/1 to 512 mug/1 before therapy. Bromocriptine suppressed G.H. values to 5 mug/1 or less in 4 patients and to less than 10 mug/1 in a further 8 patients, but in 2 patients G.H. levels did not show any significant reduction. Bromocriptine did not block stress-induced G.H. secretion. It did not distrub pituitary function other than secretion of prolactin and had negligible side-effects. Its effect on tumour size is uncertain and it is therefore unsuitable for patients with suprasellar extension of the tumour. Otherwise it seems reasonable to offer a trial of bromocriptine to all patients with acromegaly where therapy is deemed necessary. In those who show a full response of G.H. levels with a dose of 20-40 mg of bromocriptine per day, external radiation to the pituitary can be used to prevent tumour expansion and bromocriptine withdrawn at intervals to assess the effect of the radiation. In patients with a partial response to bromocriptine, the decision to offer alternative therapy depends on the extent of the response and on the age and medical condition of the patient. In patients who fail to respond to bromocriptine, particularly those younger patients with active disease, more definitive local treatment (e.g., trans-sphenoidal removal of the tumour or yttrium-90 implantation) would be indicated. Bromocriptine may also be used with benefit in the large number of patients who have shown a partial response to other forms of therapy.

11-Hydroxycorticosteroids↗
PubMed1975

Thyroid function after subtotal thyroidectomy for hyperthyroidism.

Among 76 patients who had had a subtotal thyroidectomy for hyperthyroidism from one to seven years previously recurrent hyperthyroidism was found in three and hypothyroidism in 13. The remaining 60 subjects were clinically euthyroid but a raised level of serum thyroid-stimulating hormone (TSH; greater than 5-0 mu U/ml) was found in 39. Analysis of the data showed that their serum thyroxine was significantly lower than in the subjects with a normal TSH. The serum triiodothyronine (T-3) was similar in both groups. It is concluded that subjects with a raised TSH remain clinically euthyroid by maintaining a normal serum T-3 concentration. There was no evidence of any long-term progressive deterioration of thyroid function after subtotal thyroidectomy.

Humans↗