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Biomedical subjects

R Pelkonen

Publications and source records attributed to R Pelkonen.

At least 109 records · Page 6Linked to original sources
PubMed1983

Plasma lipoproteins, lipolytic enzymes, and very low density lipoprotein triglyceride turnover in Cushing's syndrome.

Plasma lipoproteins, triglyceride turnover, and lipolytic enzymes were measured in 11 women with Cushing's syndrome. The studies were repeated 3 and 12 months after surgical treatment. Eleven healthy women of similar age and relative body weight served as controls. Before treatment the mean values of total cholesterol and triglyceride, of very low-density lipoprotein (VLDL) triglyceride and cholesterol, low density lipoprotein triglyceride and cholesterol, and high density lipoprotein cholesterol were all significantly increased in the patients with Cushing's syndrome. The triglyceride levels were only moderately elevated, the highest values being found in patients with adrenocortical adenoma. The production rate of VLDL triglyceride was higher in patients (13.2 mg/h . kg) than in controls (9.5 mg/h . kg, P less than 0.05), whereas the fractional catabolic rate of VLDL triglyceride was not significantly different. Consistent with the latter finding, the lipoprotein lipase activities of adipose tissue, skeletal muscle, and postheparin plasma were similar in patients and controls. The postheparin plasma hepatic lipase activity of the patients was at the lower end of the normal range. All lipid and lipoprotein abnormalities were completely abolished after successful surgery. It is concluded that endogenous hypercortisolism stimulates the hepatic production of VLDL particles. The effect is probably based on multifactorial mechanisms. In the presence of unchanged removal this leads to elevated levels of VLDL, low density lipoprotein, and high density lipoprotein.

Adult↗
PubMed1983

Hyperthyroidism and acromegaly caused by a pituitary TSH- and GH-secreting tumour.

A female patient with acromegaly, TSH-induced hyperthyroidism and a large eosinophilic pituitary adenoma is reported. Granules in the adenoma cells were by immunohistochemical methods shown to contain GH and with monoclonal TSH-antibodies it was shown that 5-10 per cent of the cells secreted TSH. The basal serum TSH was elevated in the hyperthyroid phases and was not suppressible by exogenous T3 but decreased markedly with dexamethasone. There was a small subnormal rise in serum TSH after TRH injection which was totally suppressed by T3 (but not dexamethasone). L-dopa, bromocriptine and somatostatin caused a 20-30 per cent decrease in serum TSH. The alpha-subunit concentration was also elevated and was equally depressed by bromocriptine and somatostatin. The urinary excretion of TRH was within reference limits. This mixed tumour obviously secreted an excess of both GH and TSH causing acromegaly and hyperthyroidism.

Acromegaly↗
PubMed1983

Increased frequency of HLA-Cw4 in type 2 diabetes.

UNLABELLED: In order to investigate whether there is an association between the HLA system and type 2 diabetes, we have determined HLA-A, B- and C-antigens in 227 patients with onset of diabetes between the ages of 35 and 70 years and compared them with the HLA-antigen frequencies in Finnish blood donors. One hundred and sixty-eight patients (74%) were treated with diet or oral antidiabetic drugs (non-insulin dependent), whereas 59 patients (26%) were treated with insulin (insulin-dependent). The HLA-antigen Cw4 was found in 38.7% of the non-insulin dependent patients (relative risk 2.67, p = 0.00005) and in 15.6% of the insulin dependent diabetics (relative risk 0.785 NS) compared with 19.1% in blood donors. In addition, there was an increase in the frequency of HLA-Bw35 antigen among the non-insulin dependent patients (relative risk 1.6, P = 0.007), which could be explained by the known positive linkage disequilibrium between HLA-Bw35 and HLA-Cw4. In insulin-dependent patients there was a decrease in the frequency of HLA-B7 (relative risk 0.226, P = 0.001) and an increase in the frequencies of HLA-B8 (relative risk 1.91, P = 0.031), B12 (relative risk 2.22, P = 0.01) and B15 (relative risk 2.04, P = 0.019) compared with blood donors. CONCLUSION: these data provide evidence that genes in the HLA region may have some influence in genetic susceptibility to type 2 diabetes. They further suggest that maturity onset (type 2) diabetes is a heterogeneous disease in terms of HLA antigens.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1983

Current therapy of pituitary Cushing's disease.

The current methods of treatment of Cushing's disease are reviewed. Therapeutic measures can be directed to all levels of the hypothalamic-pituitary-adrenal axis regulating cortisol secretion. The excessive production of cortisol can be suppressed by adrenal surgery, adrenal blocking and adrenolytic agents. The modern trend, however, is to treat the cause of the disease by pituitary surgery, radiotherapy and neuropharmacological means. The most important progress has been made in the field of transsphenoidal microsurgery which has to great extent replaced the traditional bilateral adrenalectomy.

Adrenalectomy↗
PubMed1982

Reduced level of cellular glucocorticoid receptors in patients with anorexia nervosa.

Specific glucocorticoid receptors were measured in circulating mononuclear leukocytes from 12 patients with anorexia nervosa and 21 healthy control subjects. Cells from patients were found to contain a significantly (p less than 0.01) lower level of glucocorticoid receptor (3830 +/- 210 sites/cell, mean +/- SE) than those from controls (4930 +/- 250 sites/cell). A partial glucocorticoid receptor defect may well explain the abnormal cortisol metabolism and glucocorticoid resistance commonly found in patients with anorexia nervosa.

Adolescent↗
PubMed1982

Serum lipids, postheparin plasma lipase activities and glucose tolerance in patients with prolactinoma.

UNLABELLED: Serum total cholesterol and triglyceride levels were determined in forty-seven women with prolactinoma and in eighty-four age- and weight-matched control women. Oral glucose tolerance tests (OGTT) were performed and postheparin plasma lipoprotein lipase (LPL) and hepatic lipase (HL) activities were determined in twelve patients before and after transsphenoidal removal of the prolactinoma. The mean levels of serum cholesterol and triglyceride were significantly higher in patients than in controls. The 90% cut-off line of controls for serum cholesterol was exceeded by 36% and that for serum triglyceride by 23% of the patients. The triglyceride levels were raised only in patients with GH-deficiency whereas patients with normal GH secretion had normal triglyceride. Plasma LPL activity was significantly reduced whereas plasma HL activity was in the upper range of normal. After the removal of prolactinoma the serum prolactin levels decreased in all patients and seven started to menstruate. The oral glucose tolerance was improved and the plasma insulin response decreased. Serum lipid levels and the lipase activities, however, did not change. CONCLUSION: prolactinoma is associated with metabolic abnormalities characterized by hyperlipidaemia, low plasma LPL activity and insulin resistance.

Adult↗
PubMed1982

Recurrence of chromophobe pituitary adenomas after operation and postoperative radiotherapy.

The rate of recurrence is reported in a prospective study of 56 patients (28 men, 28 women) with large chromophobe pituitary adenoma (with or without hyperprolactinemia). The surgical approach was transfrontal in 44 and transseptosphenoidal in 12 patients. Cryoapplication was combined with the transsphenoidal operation. All but one patient received postoperative pituitary irradiation. Altogether, 11 (20%) clinical relapses (10 men) occurred between 0.5 and 6 years after the transfrontal operation. Patients that relapsed had had larger tumors than those remaining in remission. Occurrence of the tumors appeared with a deterioration of the visual field defect in 9 patients. There were no differences in the degrees of hypopituitarism in patients who relapsed as compared to patients remaining in remission.

Adenoma, Chromophobe↗
PubMed1982

Interrelationship between TSH- and prolactin secretion in patients with prolactinoma and autoimmune thyroiditis.

The relationship between the TSH and prolactin (Prl) responses to TRH has been investigated in 36 patients with prolactinoma, in 12 patients with symptomless autoimmune thyroiditis (SAT) and in 10 patients with Graves's disease in remission (GD). Autoimmune thyroiditis in combination with prolactinoma was found in 3 patients. The TSH -response was exaggerated in 4 prolactinoma patients without autoimmune thyroiditis. Moreover, in the patients with prolactinoma and intact function of the non-tumours pituitary gland the mean TSH increment was higher than in the controls. In patients with SAT, on the other hand, the Prl-response to TRH was significantly greater than that in the controls and in patients with GD. The significance of these findings is not obvious but they suggest that TRH may be involved in the development of prolactin secreting adenomata.

Adult↗
PubMed1982

Seasonal variation of urinary calcium and oxalate excretion, serum 25(OH)D3 and albumin level in relation to renal stone formation.

Seasonal variations in urinary calcium and oxalate excretion, serum 25(OH)D3 and albumin level were studied in 11 normo- and 11 hypercalciuric renal stone-formers, in 10 healthy subjects and in 14 long-stay hospital patients during one year. Serum albumin levels increased significantly during May--October in all four groups, whereas no significant changes occurred in serum calcium values when adjusted for differences in serum albumin concentration. Serum 25(OH)D3 level, urinary calcium and oxalate excretion were significantly higher during May--October than November--April in all except the long-stay hospital patients, whose corresponding values showed no seasonal changes and whose serum 25(OH)D3 levels as well as urinary calcium excretion were significantly lower than in the other three groups. The serum 25(OH)D3 level was significantly higher throughout the year in hypercalciuric than normocalciuric stone-formers. The hypercalciuric patients also passed more stones than the normocalciuric patients during a period of 9 years. There was a positive correlation between serum 25(OH)D3 and urinary calcium, between serum 25(OH)D3 and stone episodes and between urinary calcium and stone episodes. Because of this positive correlation, it might be useful to concentrate preventive therapy for recurrent renal stones to the light period only.

Adult↗
PubMed1982

The influence of rapid changes in blood glucose on glycosylated hemoglobin measured by microcolumn and macrocolumn chromatography.

The effect of a rapid rise in blood glucose on glycosylated hemoglobin (HbA1) was measured by two different cation exchange chromatographic methods. Blood samples were taken after fasting and one hour after breakfast from 32 insulin treated diabetics for the measurement of 1) HbA1 with a microcolumn procedure with and without prior incubation of the samples in saline overnight and 2) HbA1 and HbA1c with the macrocolumn chromatographic method of Trivelli with and without prior dialysis of the hemolysates. Mean (+/- SEM) blood glucose concentration rose significantly one hour after breakfast from 9.8 +/- 0.8 mmol/l to 14.9 +/- 0.8 mmol/l (p less than 0.001). The corresponding HbA1-concentrations measured by microcolumn chromatography without incubation of the samples were 15.2 +/- 0.5% (fasting) of total hemoglobin and 15.8 +/- 0.6% (postprandial) (p less than 0.001) and after incubation 13.3 +/- 0.4% and 13.2 +/- 0.4%, respectively (NS). The HbA1-concentrations measured by the method of Trivelli without dialysis were 14.7 +/- 0.5% (fasting) and 14.9 +/- 0.5% (postprandial) (p less than 0.01) and after dialysis of the hemolysates 14.3 +/- 0.5% and 14.3 +/- 0.5%, respectively (NS). The HbA1c-concentrations measured by the macrocolumn method without dialysis were 11.1 +/- 0.4% (fasting) and 11.2 +/- 0.4% (postprandial) (p less than 0.05) and after dialysis 10.9 +/- 0.4% and 10.8 +/- 0.4%, respectively (NS). Acute hyperglycemia may cause an increase in HbA1-values determined by microcolumn chromatography, the magnitude of which can exceed 20% in an individual case. The acute effect can be abolished by incubation of the samples in saline overnight.

Adult↗
PubMed1981

Pituitary function in patients with enlarged sella turcica and primary empty sella syndrome.

The pituitary function in 20 patients with primary empty sella syndrome has been evaluated. The only endocrine symptom was secondary amenorrhoea in four patients. In half of the patients, pituitary function tests showed minor abnormalities, the most common being impaired growth hormone response to glucagon. In addition to the empty sella, other intracranial abnormalities such as pituitary tumour and hydrocephalus were found in four patients. Although commonly a benign condition, the empty sella may occasionally be associated with clinically important endocrine dysfunction, pituitary tumours and other intracranial abnormalities.

Adult↗
PubMed1981

Pituitary function in prolactinoma. Effect of surgery and postoperative bromocriptine therapy.

Forty-five women and fifteen men with prolactinomas have been treated surgically. Patients with large tumours received pituitary irradiation and postoperative hyperprolactinaemia was treated with bromocriptine. The patients have been followed-up for 6-36 months following the operation. The tumours were larger and the levels of production higher in men as compared with women. All women had amenorrhoea. Galactorrhoea was present in forty-three women but not in the men. After surgery serum prolactin levels fell significantly in all women but remained above normal in thirty-six; prolactin remained high in twelve men. Bromocriptine effectively decreased the postoperative hyperprolactinaemia. The surgical complications were oculomotor nerve paresis in one woman and one man. After surgery six (23%) women developed impaired GH secretion, six (15%) impaired thyroid function, eight (18%) impaired cortisol secretion and five (17%) impaired LH secretion in isolation or combination which had not been present preoperatively. Three patients relapsed. Fifteen women menstruated after surgery and ten began to do so during the subsequent bromocriptine treatment. Thus, menstruation was restored in all six women with microadenomas in sixteen of twenty patients with intrasellar macroadenomas and three of nineteen patients with suprasellar adenomas. The preoperative LH-reserve proved to be an important prognostic indicator. Nine patients, i.e. 50% of patients desiring fertility became pregnant. In the men gonadal function deteriorated in four patients and did not improve in any without testosterone treatment.

Adenoma↗
PubMed1981

Plasma insulin, C-peptide, and blood glucose in portal, hepatic and peripheral veins in liver cirrhosis. Effect of intravenous tolbutamide.

The responses of portal, hepatic and peripheral venous blood glucose (BG), plasma insulin (IRI) and C-peptide (IRC) levels to iv tolbutamide (200 mg) have been determined in 9 non-diabetic patients with liver cirrhosis and in 6 control subjects. The basal levels of plasma IRI and IRC were similar in patients and controls as were the portal and peripheral BG levels. In the hepatic vein, however, the BG-levels were higher in cirrhotic patients than in controls. After tolbutamide administration the BG-levels were unchanged in the cirrhotic patients but a significant fall in hepatic vein BG was observed in controls. In both groups of subjects the highest post-tolbutamide IRI-levels were found in the portal vein whereas the corresponding IRC-levels were as high in the hepatic as in the portal vein. The increments of portal venous IRI and IRC were significantly higher in controls as compared to the cirrhotic patients. Nevertheless, in the peripheral veins the increments of IRI and IRC were very similar in both groups of subjects or even less in the control subjects. The results suggest that in patient with liver cirrhosis the secretion of insulin is not increased but slightly decreased. The production of glucose by the liver also seems to be increased either due to insulin resistance or portal venous shunting of insulin.

Adult↗