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Biomedical subjects

F Clark

Publications and source records attributed to F Clark.

At least 91 records · Page 5Linked to original sources
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↗
PubMed1977

Value of thyroid-stimulating-antibody determinations in predicting short-term thyrotoxic relapse in Graves' disease.

Thirty consecutive patients with hyperthyroid Graves' disease received a 6-month course of antithyroid drugs. Sixteen patients relapsed within 6 months of the withdrawal of antithyroid therapy. All patients with high levels of thyroid-stimulating antibodies (TSAb) at the time of drug withdrawal relapsed within 2 months of discontinuing the antithyroid treatment while all patients with low or undetectable TSAb activity at the time of drug withdrawal remained in remission. It was not possible to predict the disease course in patients who had intermediate levels of TSAb when antithyroid therapy was stopped.

Adult↗
PubMed1977

Immunoreactive beta-melanocyte-stimulating hormone in cerebrospinal fluid and plasma in hypopituitarism: evidence for an extrapituitary origin.

Immunoreactive beta-melanocyte-stimulating hormone (beta-MSH) was measured in the plasma of 19 patients with hypopituitarism and in the cerebrospinal fluid (CSF) of five of these patients. In neither plasma nor CSF were the beta-MSH concentrations significantly different from those in normal controls. These observations raise the possibility that beta-MSH may be produced by and secreted from neural tissue; this is supported by the findings of beta-MSH in high concentrations in many parts of the brain.

Brain Chemistry↗
PubMed1977

Thyroid-stimulating immunoglobulins in ophthalmic Graves' disease.

Thyroid-stimulating immunoglobulins (TSI) have been detected by receptor assay in the sera of 43% of patients with ophthalmic Graves' disease. Comparison of the receptor assay studies with thyroid function tests indicated that in several patients the antibodies detected by receptor assay were biologically inactive. In other patients, thyroid function appeared to be under TSI control with hyperthyroidism prevented by autoimmune destruction of the thyroid.

Adult↗
PubMed1977

Practolol-induced autoantibodies and their relation to oculo-cutaneous complications.

Tissue auto-antibodies were investigated in fifty-one patients (twenty-five female, twenty-six male) receiving practolol for ischaemic heart disease or dysrhythmias and compared with those found in 204 patients (fifty-eight female, 146 male) with ischaemic heart disease who did not receive practolol. Antinuclear factor (ANF) was found in 24% female and 16% male patients receiving practolol, but only in 5% of female and 4% of male patients who were not taking practolol. Thyroid cytoplasmic antibody (TCA) was detected in 16% female and 20% of male patients receiving practolol, compared to 10% of females and 6% of males in the control group. The incidence of ANF and TCA was significantly higher (P less than 0-05) in patients receiving practolol compared to the control group. The occurrence of gastric parietal cell antibody (PCA) and smooth muscle antibody (SMA) was not associated with practolol therapy (odds ratio of 2-4 and 1-9 respectively). The incidence of skin and eye complications was found to be 10% and the female to male ratio of this complication was 4 : 1. The correlation between autoantibody production and oculo-cutaneous complications could not be established in such a small group but three of the patients with the complications were found to have PCA, although PCA was found not to be associated with practolol therapy. Four of the five patients with the complications did not have circulating ANF.

Adult↗
PubMed1977

Oxyphenbutazone-induced goitre.

A woman who had taken oxyphenbutazone for 4 years because of back pain presented with goitre and hypothyroidism. This was shown to be due to an organification defect, caused or aggravated by oxyphenbutazone.

Back Pain↗
PubMed1976

Studies on the control of thyrotrophin secretion in normal man.

The effect of graded doses of thyroxine (T4) and triiodothyronine (T3) separately on the pituitary-thyroid axis has been studied in normal subjects. It has been demonstrated that small doses (50 mug T4 or 20 mug T3) cause significant suppression of the pituitary-thyroid axis. There was a strong negative correlation between the TSH value 20 min after TRH and the dose of thyroid hormone. T4 supplements led to a progressive dose-related rise in serum T4 and no significant change in T3 until high daily doses (greater than 200 mug) were administered. T3 supplements led to a progressive reduction in serum T4 and there was no change in T3 until substantial supplements were given (greater than 50 mug/day). Concurrent administration of 6 PTU had no effect on the pattern of pituitary suppression or thyroid hormone concentrations in contrast to its reported effect in hypothyroid subjects.

Adult↗
PubMed1976

Thyroid-stimulating immunoglobulins and the control of thyroid function.

Triiodothyronine (T3) suppression and thyrotropin-releasing hormone (TRH) tests were used to study thyroid function in 50 patients with thyroid disease. The results of the thyroid function tests were compared with the levels of serum thyroid-stimulating immunoglobulins (TSI) measured by a radio-receptor assay. In euthyroid and hyperthyroid patients, the presence of TSI corresponded with the absence of TSH control of thyroid function. However, in two hypothyroid patients with serum TSI levels readily detectable in the receptor assay, T3 suppression and TRH tests indicated that thyroid function was under TSH control.

Adult↗
PubMed1975

Electrocardiographic abnormalities associated with raised intracranial pressure.

Serial electrocardiographic (E.C.G.) recordings were taken in seven patients suffering from intracranial conditions, for which their intracranial pressure was directly and continuously monitored with a Konigsberg extradural transducer. The E.C.G. changes observed in patients with raised intracranial pressure were prominent U waves, ST-T segment changes, notched T waves, and shortening and prolongation of Q-T intervals. Two patients with normal intracranial pressure showed no E.C.G. abnormalities but also establish a relationship between E.C.G. abnormalities and changing intracranial pressure.

Adult↗
PubMed1974

Neonatal hyperthyroidism and long-acting thyroid stimulator protector.

Neonatal hyperthyroidism has been thought to result from transplacental passage of long-acting thyroid stimulator (L.A.T.S.) from a mother with Graves's disease. A case is presented here in which no L.A.T.S. was detected in the mother or neonate but another immunoglobulin, L.A.T.S. protector, a specific human thyroid stimulator, was shown to be present in the mother's serum. This stimulator may have been the cause of the neonatal hyperthyroidism.

Adult↗