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Biomedical subjects

R Hall

Publications and source records attributed to R Hall.

At least 451 records · Page 25Linked to original sources
PubMed1979

Developmental protein malnutrition: influences on the central nervous system of the rat.

Our group has been carrying out interdisciplinary studies on the effects of prenatal and postnatal protein malnutrition on the developing rat brain. Anatomical, physiological, biochemical and behavioral approaches using the same animal model have revealed that protein malnutrition affects the brain at various levels, i.e., (1) anatomical, as revealed by Golgi findings of deranged dendritic trees on analysis of cortical and subcortical areas; (2) physiological, as revealed by delayed sleep pattern maturation, disturbances in seizure thresholds, slowing of sensory cortico-cortical and thalamocortical evoked potentials, and changed power in hippocampal theta activity; (3) biochemical, as revealed by marked increases in biogenic amines dating from birth, as well as modifications in tryptophan metabolism; and (4) behavioral, as revealed by various changes in responses to different kinds of aversive stimulation. Reversal studies have revealed that many changes are permanent and not amenable to nutritional rehabilitation even at birth, which is before the brain growth spurt in the rat. Our paradigm closely mimicks the human condition of low level, chronic protein undernutrition and thus reveals the underlying disturbances due to malnutrition. The dietary reversal studies are attempts at pin-pointing critical brain growth periods, beyond which recovery of functions is not possible.

Animals↗
PubMed1979

Treatment of Cushing's disease with adrenal blocking drugs and megavoltage therapy to the pituitary.

Eighteen patients with Cushing's disease were seen over a 40-month period and considered for treatment by pituitary irradiation and adrenal blocking drugs. Fourteen patients entered the study and each received megavoltage therapy to give a mean dose of 4600 rad to the pituitary over 31 days. Each patient was treated for one (two patients) or two (12 patients) years with one or both of the adrenocortical enzyme inhibitors, metyrapone or aminoglutethmide to suppress cortisol secretion. Doses were adjusted to maintain urinary free cortisol secretion below 300 nmol/24 h. One patient failed to complete the trial. Normal urinary free cortisol excretion and plasma cortisol concentration were maintained after treatment in eight of the remaining 13 patients after therapy. Only one patient required cortisol replacement and normal menstrual function was restored in five of the six women. The remaining five patients relapsed and four were subsequently treated by total adrenalectomy. It was noted that the patients who responded to treatment were substantially younger than the therapeutic failures. It is suggested that this treatment is most useful in the management of younger patients.

Adrenocorticotropic Hormone↗
PubMed1979

beta-Adrenergic blocking agents with acute antihypertensive activity.

Modification of the pharmacological profile of the vasodilating/beta-adrenergic blocking agent 2-[4-[3-(tert-butylamino)-2-hydroxypropoxy]phenyl]-4-(trifluoromethyl)imidazole (1) has been investigated. Introduction of selected substitutents onto the imidazole ring, in place of the trifluoromethyl group, has yielded highly cardioselective beta-adrenergic blocking agents such as 7, 17, and 18. The placement of alkyl or chloro groups onto the aryl ring of 1, as illustrated by 33, has produced a class of compounds characterized as antihypertensive beta-adrenergic blocking agents. In these examples, the acute antihypertensive activity does not appear to be due to either vasodilating or beta 2-agonist properties.

Adrenergic beta-Antagonists↗
PubMed1979

Several standard elective operations for duodenal ulcer: ten to 16 year clinical results.

A survey was undertaken of 558 men with duodenal ulcer who had been treated ten to 16 years previously by truncal vagotomy and drainage, truncal vagotomy and antrectomy and subtotal gastrectomy. Of the 558, 65 had died and 111, presumed living, could not be traced, leaving 382 available for assessment. Between 75 and 85% of the traced patients were considered to have an excellent or very good result, which is a slight improvement on the previously published results in this same group of patients at five to eight years follow-up. Some of the side effects of operation had diminished slightly in frequency and there had been no significant increase in the incidence of recurrent ulceration since the previous survey. Anemia was an uncommon finding. As between the various forms of operation, truncal vagotomy and antrectomy and subtotal gastrectomy demonstrated significantly better protection against proven recurrent ulcer than did truncal vagotomy and pyloroplasty (p less than 0.05). Compared with truncal vagotomy and gastroenterostomy, however, the results of both resection operations, though better, did not achieve statistical significance at p - 0.5 level (p less than 0.1). In regard to Visick gradings the resection procedures had better scores, but the differences were not significant at the p - 0.05 level, except for vagotomy and antractomy as compared with vagotomy and pyloroplasty. But it is stressed that in formulating a policy of surgical therapy for duodenal ulcer the greater inherent immediate risks of resection operations need to be borne in mind.

Drainage↗
PubMed1979

The pituitary-gonadal response to the gonadotrophin releasing hormone analogue D-Ser (TBU)6-Des Gly10-LHRH-ethylamide in normal men.

We have studied the dose-response characteristics of the LHRH analogue D-Ser (TBU)6-Des Gly10-LHRH-ethylamide administered subcutaneously to five normal male volunteers. The relative potency of the analogue is about sixty times (FSH) and forty times (LH) that of the parent peptide and the increased potency and duration of action of the analogue lead to enhanced biological effect in terms of testosterone release. The prolonged duration of action of the analogue suggests that a single daily dosage regime could be used although further chronic studies with this potent analogue should be undertaken in normal volunteers to determine optimum dosage schedules.

Adult↗
PubMed1979

Thyroid stimulating antibodies and metastatic thyroid carcinoma.

A patient with previously treated follicular carcinoma of the thyroid developed Graves' disease with a high titre of thyroid-stimulating antibodies (TSAb). He developed functioning pulmonary metastases leading to hyperthyroidism. Levels of TSAb paralleled the functional status of the metastases suggesting that hyperfunction of the neoplastic tissues was caused by TSAb.

Adenocarcinoma↗
PubMed1979

Comparison of long-acting analogues of luteinizing hormone releasing hormone in man.

Currently, LHRH, when used therapeutically, is given by parenteral injection every 8 h. We have looked at the release of LH and FSH induced by five analogues of LHRH and compared this with gonadotrophin release after synthetic LHRH. The analogues were substituted in position 6 or in positions 6 and 10 and were given intravenously, intranasally or subcutaneously in three separate studies. After intravenous administration of 100 micrograms, all analogues caused greater release of LH and FSH than did synthetic LHRH. Given intranasally in a dose of 500 micrograms, three of the four analogues tested caused greater LH and FSH release than did LHRH. With tryptophan substitution in position 6 (D-TRP6-LHRH), mean LH levels in five subjects were still above the normal range 24 h after a single intranasal dose. The intranasal administration of selected analogues of LHRH has great potential in the treatment of conditions associated with deficient gonadotrophin secretion, provided that pituitary overstimulation, which may eventually lead to a decrease in LH and FSH output by the anterior pituitary, is avoided.

Administration, Intranasal↗
PubMed1979

Effect of somatostatin on abnormal growth hormone and prolactin secretion in patients with the carcinoid syndrome.

Growth hormone (GH) secretion has been studied in two patients with the carcinoid syndrome during glucose loading and growth hormone-release inhibiting hormone (GHRIH, somatostatin) infusion. Both patients had elevated fasting GH levels which were not suppressed by glucose; GH levels fell rapidly during GHRIH infusion. One patient also had hyperprolactinaemia with galactorrhoea and the prolactin (PRL) levels were unaltered by GHRIH. The association between carcinoid tumours and abnormalities of GH and PRL secretion is discussed.

Adult↗
PubMed1979

Dopamine is a physiological regulator of thyrotrophin (TSH) secretion in normal man.

Using a sensitive and precise radioimmunoassay for human TSH we have demonstrated significant elevations in serum TSH levels in euthyroid volunteers following administration of the dopamine receptor blocking drug metoclopramide when compared with placebo. The degree of TSH response is significantly greater in females than in males and is sustained over a 3-hour period after a single oral 10 mg dose of metoclopramide. The degree of TSH release after metoclopramide is inversely related to the basal TSH level suggesting that dopamine is a determinant of low daytime TSH levels and is thus implicated in the circadian rhythm of TSH secretion. Pretreatment with 10 mg of metoclopramide orally, one hour before TRH administration leads to significant enhancement of the TSH response to TRH. Our findings provide further evidence for the physiological inhibitory role of dopamine in the contol of TSH secretion in normal man. The possible mode of action of dopamine and the clinical implications of this neuroregulatory pathway are discussed.

Adult↗
PubMed1979

Effects of radioiodine on thyrotrophin binding inhibiting immunoglobulins in Graves' disease.

We have studied the effects of 131I therapy on thyrotrophin binding inhibiting immunoglobulins (TBII) in fifty-five patients with Graves' disease and five patients with toxic multinodular goitre (MNG). A group of forty patients with Graves' disease and four patients with toxic MNG were treated with drugs and acted as controls. In 78% of patients treated with 131I there was a marked increase in the serum TBII activity during the 3 months following therapy, whereas drug-treated patient showed a decrease (77%) or no change in TBII activity over the same period. TBII activity was not detectable in patients with toxic MNG before or after drug or 131I therapy. Consideration of the mechanisms involved in the changes in serum TBII activity after 131I treatment or during drug treatment provide insight into the basic defects responsible for the development of hyperthyroid Graves' disease and suggest that both the thyroid and immune system are involved.

Female↗
PubMed1979

Function of the hypothalamo-hypophysial-thyroid axis in chronic renal failure.

Hypothalamo-hypophysial-thyroid function has been studied in twenty-five patients with chronic renal failure. Eight were receiving conservative treatment, nine peritoneal dialysis and eight haemodialysis. All were clinically euthyroid. Total thyroxine (T4) and triiodothyronine (T3) levels were reduced but free T4 levels were normal, while free T3 was reduced in patients with the most severe renal failure. It is suggested that the binding of thyroid hormones by the transport proteins is reduced and that peripheral conversion of T4 to T3 is impaired in renal failure. The thyrotrophin response to thyrotrophin-releasing hormone (TRH) is reduced in renal failure but this reduction is probably independent of alterations in thyroid hormone metabolism. Growth hormone was released by TRH in seven of the patients studied, possibly as a result of protein malnutrition.

Adolescent↗
PubMed1979

A study of triplets with Hashimoto's thyroiditis.

Genetic predisposition to Hashimoto's thyroiditis is suggested by its striking aggregation in families and its occurrence in twins. The manifestations range from overt clinical and biochemical hypothyroidism to the detection of thyroid autoantibodies in healthy, symptom-free individuals and their relatives. So far as the authors are aware, the finding of Hashimoto's thyroiditis in identical triplets has not previously been reported and they therefore present the cases of Faith, Hope and Charity, 63-year-old triplet sisters.

Adult↗