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Biomedical subjects

G Stenström

Publications and source records attributed to G Stenström.

35 records · Page 2Linked to original sources

Effects of thyroid hormone and beta-adrenoceptor blocking agents on urinary excretion of 3-methylhistidine and plasma amino acids in man.

The aim of this investigation was to study the effect of beta-adrenoceptor blockade on alterations in protein metabolism induced by administration of 3,5,3'-triiodothyronine (T3) to man. Urinary excretion of 3-methylhistidine and plasma concentrations of amino acids were measured in seven healthy subjects following 1 weeks's administration of T3 alone or T3 in combination with the selective beta 1-adrenoceptor blocking agent metoprolol or the non-selective beta-adrenoceptor blocking agent propranolol. Urinary excretion of 3-methylhistidine and plasma concentrations of valine, methionine, lysine, tyrosine, phenylalanine, isoleucine, leucine, and total essential and branched chain amino acids increased following administration of T3, probably in part reflecting accelerated muscle proteolysis. Neither metoprolol nor propranolol normalized 3-methylhistidine excretion or plasma concentrations of amino acids during T3 treatment. The results indicate that metabolic alterations induced by T3 and giving rise to enhanced 3-methylhistidine excretion and elevated concentrations of plasma amino acids are not normalized by beta-adrenoceptor blockade.

Adult↗

Pheochromocytoma in Sweden 1958-1981. An analysis of the National Cancer Registry Data.

An epidemiological study of 439 cases (184 males, 255 females) of pheochromocytoma (paraganglioma) diagnosed in Sweden from 1958-81 is presented. From the mid 1960's an average of 22 cases have been diagnosed each year. In 255 cases, the pheochromocytoma was diagnosed by clinical examination and/or surgery. In 184 cases (40%), the diagnosis was achieved by autopsy and out of which 60 (14% of all cases) were reported as incidental findings. Ninety-five pheochromocytomas (22%) were located outside the adrenals. The average (+/- SD) age at diagnosis for the total study population was 55.8 +/- 17.7 years. Clinically diagnosed tumour cases were significantly younger (48.5 +/- 16.3 years) compared to cases diagnosed at autopsy (65.8 +/- 14.0). Pheochromocytomas were more common among women than among men. The age specific incidence rate increased continuously for both sexes from the youngest to the oldest age groups. The average incidence of pheochromocytoma in the 24 counties of Sweden was 2.1 cases per million inhabitants per year, range 0.9-5.3. A North to South gradient was noted with a higher incidence in the Southern parts of the country. Whether this is due to a real geographical variation of incidence, to a larger number of unreported cases in the Northern parts, or to presence of families with Sipple's syndrome in the South is unclear.

Adrenal Gland Neoplasms↗

Reduced insulin binding to human fat cells following beta-adrenergic stimulation--experimental evidence and studies in patients with a phaeochromocytoma.

The effect of beta-adrenergic stimulation on insulin binding was studied in human fat cells in vitro. Isoproterenol rapidly (approximately 5 min) reduced insulin binding through a beta-adrenergic and dose-dependent mechanism. The reduced binding was enhanced by the addition of adenosine deaminase and was also elicited by the addition of dibutyryl cAMP. This effect was due to a decreased number of binding sites. The reduction was rapidly reversed by propranolol (t1/2 approximately 10 min) and other beta-adrenoreceptor blocking agents. Insulin binding was also measured in fat cells from 6 patients with a phaeochromocytoma. A significant negative correlation between tracer binding and the log value of total urinary catecholamine excretion was found (r = -0.821, p less than 0.05). Mean tracer insulin binding was reduced about 30% as compared to cells from 16 carefully matched control subjects. Decreased insulin binding was again mainly attributable to a decreased number of binding sites. Thus, beta-adrenergic stimulation, both in vitro and in vivo, leads to a decreased number of binding sites for insulin in human fat cells.

Adipose Tissue↗

Cardiomyopathy in phaeochromocytoma: report of a case with a 16-year follow-up after surgery and review of the literature.

A 39-year-old woman had suffered from congestive heart failure of unknown cause for 3.5 years before a phaeochromocytoma was diagnosed. After pretreatment with phenoxybenzamine, the tumour was removed by surgery resulting in disappearance of signs of heart disease. The patient was followed for 16 years: at that time she was free of symptoms and X-ray and echocardiography showed only a slightly enlarged heart and a minor impairment of left ventricular performance. Six similar cases from the literature are reviewed. The significance of catecholamines in causing heart disease in patients with phaeochromocytoma is discussed.

Adrenal Gland Neoplasms↗

Positive correlation between urinary excretion of catecholamine metabolites and tumour mass in pheochromocytoma. Results in patients with sustained and paroxysmal hypertension and multiple endocrine neoplasia.

In a series of 53 pheochromocytoma patients operated on at Sahlgren's Hospital during 1956-82, a positive linear correlation is established between the 24-hour urinary excretion of vanilmandelic acid (mumol/24 h) and tumour mass (g). A similar correlation was found between the excretion of metanephrines and tumour mass in 33 subjects. The patients were subgrouped according to their type of hypertension. A statistically significant correlation between vanilmandelic acid excretion and tumour mass persisted in groups IA (sustained hypertension without attacks), IB (sustained hypertension with attacks), and II (paroxysmal hypertension) but not in group III (miscellaneous patients). There was also a correlation between metanephrine excretion and tumour mass in groups IB (n = 8) and II (n = 12). In 10 patients with the syndrome of multiple endocrine neoplasia, a positive correlation was found between tumour mass and the excretion of vanilmandelic acid, metanephrines and adrenaline.

Adrenal Gland Neoplasms↗

The blood volume in pheochromocytoma patients before and during treatment with phenoxybenzamine.

Total blood volume (TBV), red cell volume (RCV) and plasma volume (PV) were determined in 15 pheochromocytoma patients (9 males and 6 females) prior to and during preoperative treatment with phenoxybenzamine. Seventeen healthy male volunteers served as controls. Untreated male patients did not differ from the controls with respect to TBV, RCV or PV. In the total group of pheochromocytoma patients, phenoxybenzamine, in a dose of 145.6 +/- 45.2 (SD) mg/day over 14.3 +/- 5.7 (SD) days, induced significant increases in TBV (+9.4%) and PV (+14.5%), whereas RCV remained unchanged. During phenoxybenzamine, the mean PV in male patients significantly exceeded the control mean. We conclude that pheochromocytoma patients adapt their TBV to excessive catecholamine production and that they rarely present with profound hypovolemia. Moderate but higher doses of phenoxybenzamine than previously recommended induced marked increases in TBV secondary to PV expansion. Phenoxybenzamine counteracts the development of hypovolemia most effectively, thereby constituting one of several important measures for successful surgical management of pheochromocytoma patients.

Adrenal Gland Neoplasms↗

Influence of pre-operative treatment with phenoxybenzamine on the incidence of adverse cardiovascular reactions during anaesthesia and surgery for phaeochromocytoma.

The influence of pre-operative treatment with the alpha-adrenoceptor blocking agent, phenoxybenzamine, on the incidence of adverse cardiovascular reactions during anaesthesia and surgery for phaeochromocytoma was evaluated in a series of 62 patients. Fifty-one of them received pre-operative treatment with phenoxybenzamine and eight of these were also treated with beta-adrenoceptor blocking agents. The median final daily dose of phenoxybenzamine was 160 mg and the median period of treatment 23 days. The evening before surgery and in the early morning on the day of surgery, intravenous infusion of phenoxybenzamine was given to 42 of the patients. Eleven patients operated on between 1956 and 1963 received no specific pre-operative treatment and served as a reference group. The alpha-adrenoceptor blocking treatment resulted in a considerably smoother peroperative course, as evidenced by a statistically significant reduction in the incidence of excessive blood-pressure variations. The blockade was not complete since 69% of the patients had systolic peaks greater than 175 mmHg during surgery. Pre-operative blood transfusions did not significantly affect the incidence of hypotensive episodes. Pre-operative beta-adrenoceptor blockade did not reduce the incidence of peroperative arrhythmia. On the basis of our experience, we recommend that all phaeochromocytoma patients be treated pre-operatively with alpha-adrenoceptor blocking agents.

Adolescent↗

Pheochromocytoma in pregnancy. Experience of treatment with phenoxybenzamine in three patients.

Three cases of pheochromocytoma diagnosed ante partum are reported. The first woman received phenoxybenzamine for 72 days until operation and the other 2 were given the drug for 2 and 3 days, respectively. Healthy infants were delivered by cesarean section followed by removal of the pheochromocytomas. The 29 cases reported in the literature of pheochromocytoma diagnosed ante partum and treated with alpha-receptor blockade are reviewed with respect to results of treatment. It is concluded that pheochromocytoma diagnosed during the 1st trimester is probably best managed by tumor resection as soon as possible. In order to avoid the risk of abortion during surgery in cases diagnosed in the 2nd trimester, the patient may well be brought to term under adequate treatment with an alpha-receptor blocking agent, when the infant is delivered by cesarean section followed by tumor removal. Third-trimester cases should be managed in the same way.

Adrenal Gland Neoplasms↗

Protein metabolism in skeletal muscle tissue from hyperthyroid patients after preoperative treatment with antithyroid drug or selective beta-blocking agent. Results from a prospective, randomized study.

Protein metabolism in skeletal muscle tissue was studied in three groups of patients undergoing thyroid surgery: group I (n = 8), hyperthyroid patients preoperatively treated with an antithyroid drug and T4; group II (n = 8), hyperthyroid patients preoperatively treated with the beta 1-selective adrenoreceptor blocking agent metoprolol; group III (n = 5), euthyroid patients operated on for nodular goiter or adenoma. The study was prospective and hyperthyroid patients were randomly allocated to one of the two preoperative regimens. During operation a biopsy was taken from the sternohyoid muscle and rates of protein synthesis and degradation were measured in incubated muscle tissue. Clinical improvement was equal in the two groups of hyperthyroid patients during preoperative treatment but serum T3 concentrations remained elevated in patients treated with metoprolol. Thus, these patients were biochemically hyperthyroid at the time of operation. The rate of protein degradation was significantly higher in hyperthyroid patients treated with metoprolol than in patients of groups I and III. A significant positive correlation was found between serum T3 and rate of protein degradation in skeletal muscle. Protein synthesis rates were similar in the three groups of patients. This study demonstrated for the first time increased proteolysis in skeletal muscle tissue from patients with high serum T3 concentrations. The results indicate that changes of skeletal muscle protein metabolism in hyperthyroid patients are not normalized by beta 1-blockade despite the fact that this treatment effectively controlled symptoms and signs of hyperthyroidism.

Adrenergic beta-Antagonists↗

Diabetes mellitus in phaeochromocytoma. Fasting blood glucose levels before and after surgery in 60 patients with phaeochromocytoma.

Sixty patients undergoing operation for phaeochromocytoma were investigated in the pre- and postoperative states with respect to fasting blood glucose levels. When 6 previously known or suspected diabetics were excluded, preoperative diabetes (fasting blood glucose levels greater than or equal to 7.0 mmol/l) were found in 3 of 13 (23%) with sustained hypertension, in 6 of 12 (50%) with sustained hypertension associated with paroxysms and in 4 of 24 (17%) with paroxysmal hypertension. None of the 5 patients with atypical clinical symptoms had glucose levels greater than or equal to 7.0 mmol/l. In the groups of patients with particularly high urinary excretion of catecholamines and vanilmandelic acid higher blood glucose levels were also found. The postoperative blood glucose levels in the follow-up study were normal and less than 5.8 mmol/l in all cases except in 3 of the 4 still living patients with a previously known diabetes and in 1 patient with a malignant tumour. Thus, manifest diabetes, defined as fasting glucose levels greater than or equal to 7.0 mmol/l, is frequently present in patients with phaeochromocytoma (24% in the present study) and the diabetes is reversed by removal of the tumour.

Adrenal Gland Neoplasms↗

Excretion of adrenaline, noradrenaline, vanilmandelic acid and metanephrines in 64 patients with pheochromocytoma. Results of repeated analyses in patients with sustained and paroxysmal hypertension.

Sixty-four patients with pheochromocytoma were operated upon at Sahlgrenska Hospital during 1956-82. The excretion of adrenaline and/or noradrenaline as well as their metabolites was high at each observation in 28 subjects with sustained hypertension, one patient, however, showing only slightly increased excretion of adrenaline at one observation. Another of the hypertensive patients consistently displayed normal amounts of vanilmandelic acid and metanephrines. Most of 28 patients with paroxysmal hypertension showed similar results. In five subjects with few attacks, however, normal findings were obtained on one or several occasions. Among the remaining patients the excretion of catecholamines was normal in the face of severe hypertension in two, the high blood pressure being probably due to diseases other than pheochromocytoma. Five normotensive subjects without hypertensive attacks presented variable findings. The results from analyses of catecholamines were somewhat more helpful than those from measurements of vanilmandelic acid, which failed completely in one hypertensive patient and in three others with paroxysmal attacks.

Adrenal Gland Neoplasms↗

Surgical excision of an adrenal myelolipoma.

Myelolipoma of the adrenal gland is a benign tumour composed of fat and haematopoietic cells. It is usually asymptomatic and discovered as an incidental finding at autopsy. Only twenty-five patients have previously been described in whom an adrenal myelolipoma had been removed surgically. The patient reported in this paper had a myelolipoma in his left adrenal gland. The tumour was diagnosed by intravenous pyelography, ultrasonography, arteriography and computed tomography. No endocrine symptoms were present and hormonal analyses were normal. Surgical excision of the tumour was performed with an uneventful postoperative course. The diagnosis should be considered in patients with a suprarenal mass manifesting features that are atypical of other tumours of this region.

Adrenal Gland Neoplasms↗