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Biomedical subjects

N Norman

Publications and source records attributed to N Norman.

At least 37 records · Page 2Linked to original sources
PubMed1987

Decreased central dopaminergic activity in essential hypertension.

Baseline serum prolactin (PRL) was found to be similar in 35 men with untreated essential hypertension (149 +/- 2/98 +/- 1 mmHg; means +/- s.e.) and 44 healthy normotensive men (126 +/- 1/80 +/- 1 mmHg), all 40 years old. A correlation between baseline PRL and aldosterone was found in the normotensive (r = 0.534, P less than 0.001), but not in the hypertensive group (r = -0.011, NS). Ten subjects from each group received intravenous metoclopramide, a competitive dopamine antagonist, while another 12 normotensive subjects were given saline only, and the effect on PRL, vasopressin (AVP) and catecholamines was followed. An exaggerated PRL response to metoclopramide was observed in the hypertensive group compared with the normotensive (P less than 0.05), and the mean normotensive peak value never exceeded the hypertensive. Plasma noradrenaline increased significantly compared with baseline (P less than 0.05) and the control group (P less than 0.001), concomitant with increased heart rate (P less than 0.05), after the administration of metoclopramide both in the hypertensive and normotensive group. After intravenous injection of metoclopramide, forearm blood flow increased significantly by 50% in the hypertensive (P less than 0.001), and 80% in the normotensive group (P less than 0.001) compared with the control group. Mean blood pressure remained unchanged as did plasma AVP, dopamine and adrenaline. The present study indicates an altered central dopaminergic activity in essential hypertension. Even at rest, endogenous dopamine exerts a modulating effect on noradrenaline release in both hypertensive and normotensive men.

Adult↗
PubMed1987

Gynaecomastia following cytotoxic therapy for testicular cancer.

Sixteen patients in complete remission after chemotherapy or radiotherapy for testicular cancer developed gynaecomastia which appeared 2 to 9 months after the end of therapy and had a mean duration of 4.8 months. These patients had statistically significant higher levels of oestradiol, FSH and oestradiol/testosterone ratio than a control group without gynaecomastia that had received similar treatment. Both groups tended to have testosterone levels in the lower normal range and all patients had normal levels of beta-HCG, prolactin and progesterone. The gynaecomastia in our patients was probably the result of an absolute increase in oestradiol or an increase relative to testosterone. Cytotoxic therapy affects both spermatogenesis and Leydig cell function, with a resultant rise in gonadotrophins which may in turn increase testicular oestrogen secretion. In testicular cancer patients, gynaecomastia may be a sign of tumour activity but it may also be caused by hormonal changes resulting from cytotoxic therapy. It is our experience that the latter treatment-related type is harmless, transient and unrelated to the patient's prognosis.

Adolescent↗
PubMed1987

Endocrine effects of ovarian electrocautery in patients with polycystic ovarian disease.

The mechanism by which ovarian electrocautery induces regular ovulatory cycles was studied in 16 women with polycystic ovarian disease (PCO) and compared with 25 normal fertile women who were undergoing sterilization by tubal electrocautery. Gonadotrophins (LH and FSH), prolactin, androgens, oestrogens, 17-hydroxyprogesterone and progesterone were determined immediately before operation and 24 h later. Following the sampling of blood for these tests, 100 micrograms of gonadotrophin releasing hormone (GnRH) was given intravenously and the LH and FSH responses were measured at 30 min. In the PCO-group, these tests were repeated after the first induced ovulatory cycle. After operation, LH increased only in the patients with PCO and this increase was associated with an enhanced response to GnRH, FSH showed a similar response to GnRH, also confined to the PCO-group. These pituitary responses are best explained by a change in ovarian feedback induced by the direct electrocautery of the glands in the PCO-group. There was little change in serum oestrogen. Prolactin showed an increment in all cases and serum androgens were reduced in all groups, most pronounced in the PCO patients, possibly as a result of the stress of operation. An ovarian factor--released or reduced by the electrocautery--seems to be responsible for the changes.

Adult↗
PubMed1987

Ketoconazole high dose in the hormonal treatment of advanced carcinoma of the prostate. A pilot study.

Five previously untreated patients with advanced carcinoma of the prostate were treated with the non-estrogenic antifungal agent Ketoconazole in high doses. A rapid fall in serum testosterone, adrenal androgens and serum prostatic acid phosphatases was recorded accompanied by a striking clinical response with reduction of skeletal pain and improvement of performance status. In one patient this was dramatically shown by reduction of a large pelvic tumor and associated edema of the left lower limb. Side-effects such as weakness, fatigue and loss of appetite made four of the patients withdraw from the study. Serum testosterone and serum prostatic acid phosphatase initially suppressed, increased slowly during the treatment period. Consequently, Ketoconazole as sole therapy in the treatment of advanced carcinoma of the prostate was stopped. However, the initial rapid decrease in serum testosterone and the striking positive clinical effect may possibly be utilized combined with orchiectomy or treatment with LHRH agonist analogues.

Adenocarcinoma↗
PubMed1987

Endocrine and haemodynamic responses to graded dopamine infusion in essential hypertension.

Hormonal, mean arterial blood pressure, forearm blood flow and heart rate responses to graded dopamine infusion (0.5-2.0 micrograms/kg/min) were examined in 10 men with untreated essential hypertension WHO group I (147 +/- 4/100 +/- 1 mmHg, means +/- SE), and in 10 normotensive men (129 +/- 2/85 +/- 1 mmHg), all 40 years old. Another 12 normotensive men (126 +/- 3/80 +/- 2 mmHg) were given only saline infusion. Dopamine increased heart rate significantly in the hypertensive group (8 +/- 2 beats/min, p less than 0.001), but the heart rate remained unchanged in the normotensive group (1 +/- 1 beats/min, NS). Although dopamine infusion tended to decrease mean blood pressure, the changes were not significantly different from those observed in the control group. No change in forearm blood flow was observed in either group. In the groups given dopamine, prolactin levels decreased only slightly compared to the control group given saline, the decrement tending to be more pronounced in the hypertensive group. Plasma vasopressin remained unchanged in both groups during dopamine infusion. These results indicate that hypertensive patients exhibit increased sensitivity to the cardiovascular effects of dopamine.

Adult↗
PubMed1986

Pills and attitude change: misattribution of arousal or excuses for negative actions?

Two experiments evaluated the competing interpretations of cognitive dissonance and impression management theories regarding the pill and misattribution studies of attitude change in the forced compliance situation. Attitude change was eliminated when subjects were told about the tension side effects of taking a placebo, replicating the usual effect. Attitude change was also eliminated, however, when subjects took the pill following counterattitudinal behavior. In one condition of the second experiment, subjects were given instructions about tension side effects but were also told that the drug would not affect their moral judgment or behavior. These instructions eliminated attitude change in a standard pill condition. The typical finding of attitude change was manifested in the misattribution/no-excuse condition. The primary and secondary data from both studies provided more support for the impression management interpretation of the standard misattribution manipulations than for a theory of misattribution of dissonance-produced arousal.

Arousal↗
PubMed1986

Plasma somatostatin is elevated in primary hypothyroidism compared with hyperthyroidism.

Increased pancreatic somatostatin (somatotrophin release inhibiting factor (SRIF) has been found in hypothyroid rats. Therefore, we wanted to investigate plasma SRIF in patients with hypo- and hyperthyroidism. Two groups of patients, 7 cases with autoimmune hypothyroidism, 31-75 years old, and 7 cases with Graves' disease, 19-43 years old, were compared with regard to plasma SRIF before, during and after an arginine infusion (0.5 g/kg/20 min). None of the patients suffered from diabetes mellitus or obesity. Plasma SRIF was higher in the hypothyroid patients (mean basal value 21.5 +/- 3.9, peak value 28.7 +/- 5.1 pmol/l) compared with the hyperthyroid group (mean basal value 11.6 +/- 3.3, peak value 16.2 +/- 4.0 pmol/l). The hypothyroid group also had significantly higher serum insulin values during arginine stimulation. No difference was found in plasma glucagon, serum growth hormone (GH) or blood glucose. In conclusion, plasma SRIF is elevated in primary hypothyroidism compared with hyperthyroidism. The reason for this finding is uncertain, but a reduced SRIF clearance is a possible explanation. The association of our findings with the reduced glucose tolerance in hyperthyroidism is discussed.

Adult↗
PubMed1985

Adrenaline and preeclampsia.

Twenty-one preeclamptic women had increased venous plasma-free adrenaline (45 +/- 5 vs 27 +/- 2 pg/ml, mean +/- SE, P less than 0.01) and plasma-free dopamine (137 +/- 25 vs 55 +/- 6 pg/ml, P less than 0.01) compared with fifteen normotensive pregnant women. Plasma renin activity (P less than 0.001) and aldosterone concentration (P less than 0.02) were depressed in the preeclamptic and serum potassium increased (P less than 0.02). Plasma adrenaline correlated with blood pressure (r=0.80, P less than 0.001) supporting increased sympathetic nervous tone in the development of preeclampsia.

Adult↗
PubMed1985

Effects of synthetic corticotropin-releasing factor in normal individuals and in patients with hypothalamic-pituitary-adrenocortical disorders.

Plasma adrenocortical hormone (ACTH) and cortisol response to four dose levels (25, 50, 100 and 300 micrograms) corticotropin-releasing factor (CRF) were studied in 5 healthy men, and the response to 100 micrograms CRF in 12 patients with various disorders of the hypothalamic-pituitary-adrenocortical function. In normals, mean plasma ACTH and cortisol concentration rose at all dose levels of CRF and peaked at 30 and 60 min respectively. The increment in plasma cortisol at 60 and 90 min was significantly higher on 100 and 300 micrograms CRF than on 25 micrograms, but the total cortisol concentration was not. Seven patients had Cushing's syndrome. In 2 patients with adrenocortical carcinoma the basal plasma ACTH was suppressed. After CRF a small increase was seen in plasma ACTH and cortisol in one patient successfully treated with mitotane, while the other patient did not respond. In 1 patient with ectopic ACTH syndrome an increase in plasma ACTH 15 min after CRF was not accompanied by any increase in plasma cortisol. One patient with bilateral multinodular adrenocortical hyperplasia did not respond to CRF. The plasma ACTH and cortisol response to CRF was supernormal in 2 patients with Cushing's disease, while a third patient responded in the normal range. In 2 patients with Nelson's syndrome the plasma ACTH response was excessive. Two out of three hypophysectomized patients did not respond to CRF, while one patient with a slightly positive response to hypoglycemia also responded (subnormally) to CRF. Our data indicate that CRF in doses of 50-100 micrograms will be a valuable substance in the differential diagnosis of Cushing's syndrome. Some overlap in the response is, however, seen between patients with Cushing's disease and other patients with Cushing' syndrome. CRF will possibly be of value also for the diagnosis of secondary adrenocortical failure.

Adrenocorticotropic Hormone↗
PubMed1985

Post-treatment fertility in patients with testicular cancer. II. Influence of cis-platin-based combination chemotherapy and of retroperitoneal surgery on hormone and sperm cell production.

Active sperm production was observed in 20 of 35 patients with testicular cancer 1 year after discontinuation of all treatment (retroperitoneal surgery only: 13; cis-platin-based chemotherapy (CVB) +/- other treatment: 22). The percentage of patients who regained spermatogenesis increased slightly after a further 1 to 2 years. Fourteen patients (of 121 under observation) impregnated their wives (after retroperitoneal surgery: 9; after CVB +/- other therapy: 5). The individual serum FSH values correlated significantly with the results of sperm analysis: an FSH value greater than or equal to 20 iu/l indicated azoospermia in 8 of 12 patients, whereas only 5 of 30 patients with FSH levels less than or equal to 12 iu/l were azoospermic. Serum testosterone and pituitary serum LH were virtually unaffected by the treatment. In conclusion, 1 to 3 years after cis-platin-based multi-modality treatment for testicular cancer, 50 to 60% of patients have active spermatogenesis and fatherhood can be achieved by a significant number of them.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1985

11-Deoxycortisol induces hepatic tryptophan oxygenase in rats.

11-Deoxycortisol (cortexolone) has previously been used as a glucocorticoid antagonist in vitro and in adrenalectomized rats. Antiglucocorticoid properties of 11-deoxycortisol in intact rats were examined by studying the effect of 11-deoxycortisol on the induction of hepatic tryptophan oxygenase (TO) by corticosterone. No antiglucocorticoid effect was observed. When 11-deoxycortisol was injected into rats, the TO activity increased. This was probably mainly caused by an elevation of the serum corticosterone level. The induction of TO by 11-deoxycortisol was inhibited by metyrapone. However, 11-deoxycortisol (100 mg/kg) was still not a glucocorticoid antagonist even in presence of metyrapone.

17-Hydroxycorticosteroids↗
PubMed1985

Increased peripheral venous somatostatin concentration and decreased glucagon response to arginine in patients with insulin dependent diabetes mellitus without residual B-cell function. Increased plasma SRIF in IDDM.

The glucagon response to insulin hypoglycaemia is frequently reduced in patients with IDDM. In the present study arginine infusion, thought to act directly on the islet cells, was used to stimulate somatostatin (SRIF) and glucagon in IDDM without residual B-cell function. Thirteen IDDM patients' were compared with 13 sex- and age matched normal controls following an arginine infusion. The plasma SRIF concentrations in the 'IDDM group' and normal controls increased from 24.2 +/- 2.5 to 31.1 +/- 3.9 pmol/l (P less than 0.01) and 19.7 +/- 1.7 to 23.9 +/- 3.4 pmol/l respectively after 10 min (P less than 0.01). The plasma glucagon concentrations increased from 27 +/- 4.7 to 176 +/- 23.1 pmol/l (P less than 0.01) and 36 +/- 5.0 to 302 +/- 31.9 pmol/l (P less than 0.01) respectively after 20 min. Thus, in long standing IDDM without residual B-cell function, increased plasma SRIF concentrations are found and the glucagon response to arginine is reduced. The last observation further explains why these patients are especially vulnerable to hypoglycaemia.

Adolescent↗
PubMed1981

The influence of dihydralazine and angiotensin-II blockade on renal extraction of [131I]hippuran.

The renal extraction of [131I]ortho-iodohippuran ([131I]OIH) was measured during the first minutes after the bolus injection during renal vein catheterization of two groups of hypertensive patients. Concomitantly the hippuran clearance (effective renal plasma flow (ERPF) was determined with a quantitative renographic technique based on net kidney uptake between 1 1/2 and 2 1/2 min and plasma radioactivity 2 min after the bolus injection of hippuran. The study was repeated 30 min after intravenous administration of dihydralazine (0.1 mg/kg body weight) in 14 subjects (group A) and during continuous infusion of the angiotensin II blocking agent Saralasin (5 micrograms/kg . min) in 10 subjects (group B). Before dihydralazine was given, the rate of [131I]OIH extraction was (Mean +/- S.D.) 74.0 +/- 16.7% in the 2 min sample after bolus injection of hippuran, 67.5 +/- 17.3% after 10 min, falling to 53.0 +/- 15.3% after 30 min. There was no difference after dihydralazine administration, as the extraction values were 75.6 +/- 17.5 and 65.6 +/- 21.4% 2 and 10 min after the bolus injection of hippuran. The extraction values before Saralasin infusion were 74.2 +/- 15.7%, 59.8 +/- 18.2% and 47.1 +/- 16.6% at 2, 10 and 25 min after bolus injection of hippuran. Saralasin elicited no change in the extraction, as the values were 74.1 +/- 18.6% and 64.3 +/- 23.2%, 2 and 10 min after hippuran injection. For kidneys with ERPF above 100 ml/min . 1.73 m2 the extraction 2 min after hippuran injection was at the level of 82%, whereas the extraction fell rapidly with further reduction in ERPF. It is concluded that ERPF determined with the renographic technique, reflects the renal plasma flow when the clearance for the individual kidney exceeds 100 ml/min . 1.73 m2. This is the case also after dihydralazine and Saralasin administration.

Adult↗