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Biomedical subjects

A Gunn

Publications and source records attributed to A Gunn.

At least 73 records · Page 4Linked to original sources
PubMed1984

Beta-adrenoceptor blockade and anaesthesia for thyroidectomy.

The administration of beta-adrenoceptor blocking drugs in the pre-operative preparation and operative management of thyrotoxic patients undergoing subtotal thyroidectomy is reviewed. Particular reference is made to some of the recent advances and it is emphasised that there has been a considerable reduction in the incidence of problems following judicious use of these drugs. The choice of anaesthetic technique employed for thyroidectomy is less important than the degree of control of thyrotoxicosis by the beta-adrenoceptor blocking drug. Propranolol has proved safe and effective for the majority of patients. The longer acting agent nadolol is easier to administer, particularly in the peri-operative period. Patients are rendered less thyrotoxic and safety thereby enhanced by adding potassium iodide for 10 days preoperatively. The combination of nadolol and potassium iodide offers real advantages in the preparation of the thyrotoxic patient for surgery.

Adrenergic beta-Antagonists↗
PubMed1983

Late onset hypothyroidism after subtotal thyroidectomy for hyperthyroidism: implications for long term follow-up.

A follow-up register has been used in Aberdeen and Dundee to record early and late onset hypothyroidism occurring in a large population of post-thyroidectomy patients treated for hyperthyroidism. In one centre, in a total of 1170 patients, the prevalence of postoperative hypothyroidism, at the time of entry to the register, was 41 per cent. Of these early cases of hypothyroidism 93 per cent occurred within 18 months of operation. Results are presented from a 12-year prospective study of patients treated in two centres, who were euthyroid when entered on the follow-up register. In one centre, based on 683 patients, the 10-year incidence of late onset hypothyroidism estimated by actuarial methods was 7.4 per cent (95 per cent confidence limits, 3.8-11.1); in the other centre with 156 patients the 5-year incidence was 10.8 per cent (95 per cent confidence limits, 3-18.6). The minimum predicted annual incidence is 1 per cent. Large thyroid remnants do not protect some patients against early or late postoperative hypothyroidism but do lead to an increased risk of recurrent hyperthyroidism. Hypothyroidism after subtotal thyroidectomy for hyperthyroidism shows a bimodal pattern and this study emphasizes the need to maintain life-long follow-up.

Follow-Up Studies↗
PubMed1983

Moniezia expansa: the interproglottidal glands and their secretions.

Acetylcholinesterase (EC 3:1:1:7) and alkaline phosphatase (EC 3:1:3:1) were detected in secretions of Moniezia expansa maintained in vitro. Ultrastructural cytochemical studies demonstrated acetylcholinesterase activity on the surface of the microtriches at the base of the interproglittidal glands and in the gland lumen but not in the distal tegument or the gland cells. Alkaline phosphatase activity was demonstrated in the cytoplasm of the gland cells and especially in their protoplasmic connections with the distal tegument. Activity was also found in the distal tegument and the microtriches. It is suggested that the acetylcholinesterase secreted by M. expansa performs a metabolic role at the worm's surface.

Acetylcholinesterase↗
PubMed1983

The destruction of peripheral-blood lymphocytes by extracorporeal exposure to ultraviolet radiation.

Venous blood from healthy adult human donors was circulated through a wholly extracorporeal circuit for periods up to 140 min without apparent damage to the lymphocytes. However, when the blood was exposed to short-wave ultraviolet radiation (UVC; lambda, 254 nm), separated mononuclear cells showed a depressed response to mitogen stimulation: the magnitude of this effect was related to the duration of exposure. This depression cannot be attributed to change in blood pH, partial pressures of oxygen and carbon dioxide, temperature of cell trauma. Plasma from irradiated blood was less satisfactory than non-irradiated plasma for the support of growth of phytohaemagglutinin-stimulated lymphocytes in culture, probably because of depletion of essential nutrients, and there was little evidence for the generation of growth-inhibitory humoral factors. The UVC-irradiated lymphocytes had normal ultrastructure when removed from the extracorporeal circuit, but underwent apoptosis and necrosis during the first day of tissue culture with or without mitogen stimulation.

Adult↗
PubMed1982

Nadolol and potassium iodide in combination in the surgical treatment of thyrotoxicosis.

With the two aims of rapidly reducing circulating thyroid hormone levels and controlling the symptoms of thyrotoxicosis, we have prepared 17 thyrotoxic patients for subtotal thyroidectomy, using a combination of potassium iodide administered for 10 days and the long acting beta-adrenoceptor antagonist nadolol. All 17 patients had normal serum thyroxine levels after 10 days of such treatment although 10 still showed elevation of serum tri-iodothyronine and considerable elevation in the most severely toxic patient. All patients were, however, clinically euthyroid preoperatively. Nadolol was administered once daily, hence avoiding the problems of drug administration in the immediate postoperative period, and plasma nadolol concentrations were high throughout the perioperative period. Serum thyroxine and tri-iodothyronine levels were significantly lower and reverse tri-iodothyronine levels higher 24 h postoperatively than before operation. All patients remained stable throughout the perioperative period. We conclude that this regimen has a number of advantages in the preparation of patients for thyroidectomy, in reducing the degree of thyrotoxicosis, in convenience of drug administration and in ensuring adequate circulating concentrations of beta-adrenoceptor antagonist whilst still retaining a relatively short preoperative phase of drug treatment.

Adrenergic beta-Antagonists↗
PubMed1981

Familial benign hypercalcaemia.

At least ten members in four generations of a large family had familial benign hypercalcaemia (FBH) (familial hypocalciuric hypercalcaemia). Three members of the family had had parathyroid explorations (one on two occasions) before it was realised that they did not have primary hyperparathyroidism. FBH resembles hyperparathyroidism in that the plasma phosphate level is often in the low-normal range and in that parathyroid hormone is often detectable in the plasma. Urinary excretion of calcium is exceptionally low in FBH; indices reflecting tubular handling of calcium, such as calcium excretion per litre of glomerular filtrate, are better than 24 h urinary calcium in discriminating between FBH and primary hyperparathyroidism.. FBH may be more common than is generally appreciated; it is important that it should be recognised so that patients may be spared unnecessary surgery.

Adult↗
PubMed1981

Conservative parotidectomy by the peripheral approach.

A series of 30 consecutive conservative parotidectomies is reported with a detailed assessment of the extent and duration of facial nerve damage. There was one case of severe temporary facial nerve paralysis but no cases of permanent palsy. All operations were performed using the peripheral approach to the facial nerve and the technique employed is described.

Adult↗
PubMed1981

Hyperparathyroidism in peptic ulcer patients.

The high incidence of peptic ulcers and abdominal pain from other causes in patients with primary hyperparathyroidism has been recognized for many years. This paper reports 20 patients with hyperparathyroidism: 12 with peptic ulcers and 8 with abdominal pain from other causes. Only in a minority of these was the diagnosis of hypercalcaemia made as a result of a deliberately sought assay; in most the plasma calcium had been measured as part of a 'screening' procedure with a multichannel analyser. In almost all of the patients who had parathyroid surgery the abdominal symptoms were completely relieved. We urge that plasma calcium assays should be made in all patients with dyspepsia particularly those with recurrent symptoms.

Abdomen↗
PubMed1981

Propranolol in the surgical treatment of hyperthyroidism, including severely thyrotoxic patients.

The perioperative course of 44 hyperthyroid patients prepared for surgery with propranolol alone, including 11 with severe thyrotoxicosis was compared to that of 20 euthyroid patients prepared for surgery with carbimazole. Conventional propranolol at a dosage of 160 mg/day was frequently insufficient to produce a high degree of beta-adrenergic blockade, particularly in severely thyrotoxic patients. A greater than 25 per cent reduction in sitting pulse rate was associated with a high degree of beta-blockade. The clinical course of patients with mild or moderate thyrotoxicosis was similar to that of the patients prepared with carbimazole. In contrast, the course of severely thyrotoxic patients was complicated and, in addition to a higher preoperative propranolol dosage, these patients commonly required supplemental propranolol after operation. Although thyroid crisis did not occur in any patient, we cannot recommend the use of propranolol alone for the severely thyrotoxic patient.

Adult↗
PubMed1981

Altered endocrine response to partial thyroidectomy in propranolol-prepared hyperthyroid patients.

The endocrine response to partial thyroidectomy in a group of twenty hyperthyroid patients prepared with propranolol alone was compared to that of a matched control group of ten euthyroid patients. In propranolol-prepared patients the glucose response to surgery was reduced (P less than 0.05) for up to 4 h post-operatively and biochemical hypoglycaemia was noted in one patient. Both thyroxine and triiodothyronine (T3) fell significantly, associated with a marked rise in reverse T3. Growth hormone levels were higher (P less than 0.05) both pre- and post-operatively in propranolol-prepared patients, whereas prolactin levels, although similar pre-operatively, were lower (P less than 0.05) in these patients post-operatively. Cortisol and ACTH levels were lower (P less than 0.05) both before and following thyroidectomy in propranolol-prepared patients. These results suggest that the endocrine response to surgical stress is markedly altered in propranolol-prepared hyperthyroid patients.

Adrenocorticotropic Hormone↗
PubMed1981

The relationships between surgical histometry, outcome and pre-treatment in Graves' disease.

Quantitative histometric methods were used to established the relationships between the extent of thyroid lymphocytic infiltration at operation, and outcome exactly 18 months later in 50 surgically-treated Graves' disease patients prepared by carbimazole and triiodothyronine. Periods of pre-operative treatment, surgical technique, histometric analysis and diagnostic criteria were all standardised. Controls (107) were obtained from the forensic laboratory. Thirty-seven patients became euthyroid, but there was no relationship between outcome and epithelial or lymphoid content of the thyroid gland. Neither was there any correlation between the size of lymphoid infiltrate and epithelial mass of the resected thyroids, suggesting that simple lymphocyte infiltrations do not replace thyroid tissue as once thought. The variation in thyroid epithelial content was nearly 3-fold, so that a surgeon, even if able accurately to judge the anatomical mass of the remnant, would still have little or no idea of its functional mass. The scatter of epithelial content was even greater in glands from patients prepared for surgery by propranolol alone (38 glands, variation X 5.5) or propranolol and iodide (32 glands, variation X 5.9). Outcome after sub-total thyroidectomy for Graves' disease seems unrelated to the lymphocyte content of the gland and it is questionable to what extent the surgeon can either predict or control the outcome of thyroidectomy in individual Graves' disease patients.

Adult↗
PubMed1980

Influence of surgery on plasma propranolol levels and protein binding.

The influence of surgery and anesthesia on perioperative plasma propranolol levels was studied in 25 hyperthyroid and five euthyroid patients undergoing thyroidectomy. Propranolol levels fell markedly after surgery as a consequence of poor drug administration in the immediate postoperative period due largely to patients' nausea and inability to swallow. Propranolol was not detectable in the plasma of three hyperthyroid patients 8 hr after surgery. When propranolol was given through a nasogastric tube, propranolol levels were satisfactory throughout. Compared with preoperative levels, in all patients there was a two- to threefold rise in total and free propranolol levels 24 hr after surgery, suggesting decreased hepatic clearance of propranolol. The degree of plasma protein binding of propranolol had also increased on the day after surgery, leading to a 30% reduction in propranolol free fraction. Surgery and anesthesia greatly influence the handling of propranolol in the perioperative period.

Absorption↗