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Biomedical subjects

F Berthezene

Publications and source records attributed to F Berthezene.

At least 19 recordsLinked to original sources
PubMed1992

Hypertriglyceridemia: cause or consequence of insulin resistance?

An overproduction of VLDL by the liver and a slower clearance of these lipoproteins are usually seen in diabetic patients. There is correlation between insulin resistance and plasma triglyceride concentration. Triglyceride may influence an early step in the insulin action pathway and alternatively, insulin resistance may cause hypertriglyceridemia. Hyperinsulinemia and/or hypertriglyceridemia may play a strong role in the cardiovascular risk of patients with type II diabetes. There is an important need to conduct trials to define therapy that can reduce the risk of cardiovascular complications.

Cardiovascular Diseases↗
PubMed1987

Influence of vitamin E administration on platelet functions in hormonal contraceptive users.

Platelet functions (aggregation, clotting activity), platelet lipid biosynthesis, sterol composition and phospholipid fatty acids were studied in relation to plasma lipids and fatty acids as well as dietary habits at day 5 and 21 of the menstrual cycle in 30 women having used hormonal contraceptive for several years. The women were studied again on day 21 of the second cycle after they had taken for two months 200 mg vitamin E per day in addition to the contraceptive. At day 21 (after 3 weeks of hormonal contraceptive) as compared to day 5, there was a significant increase in the clotting activity of platelets and the response to ADP-induced aggregation concomitant with a decrease in plasma vitamin E. After vitamin E administration, platelet activity at day 21 was markedly decreased, being similar to the activity at day 5, with a significant increase in the level of vitamin E in plasma and platelets. The high response of platelets to aggregation in women using contraceptives does not seem to be associated with the intake of saturated fat but rather with that of 18:2. The aggregation to thrombin was mostly related to lanosterol biosynthesis and the aggregation to ADP to platelet cholesterol, but not to plasma lipids or apoproteins. The present pilot study suggests that the platelet hyperactivity of long-term hormonal contraceptive users might be dependent upon a low level of platelet alpha-tocopherol which can be rapidly overcome by giving a supplement of vitamin E.

Adult↗
PubMed1987

High density lipoprotein alterations induced by bezafibrate in healthy male volunteers.

The alterations of HDL structure and metabolism induced by bezafibrate administration were studied in healthy male volunteers. As usually observed in hyperlipaemic patients, bezafibrate induced a decrease of the plasma concentrations of apo B and LDL-cholesterol and an increase of that of HDL-cholesterol. Analysis of HDL by gradient polyacrylamide gel electrophoresis revealed that bezafibrate administration resulted in a change of the particle size distribution likely suggesting a drop of the HDL2/HDL3 ratio. This was accompanied by a 30% enhancement of the plasma concentration of apoprotein A-II, while that of apoprotein A-I remained unchanged. These data suggest an increase of the HDL concentration, preferentially in the HDL3 subfraction. In spite of these HDL alterations, there was no evidence of change in the three stages of the reverse pathway of cholesterol, since bezafibrate did not induce any significant alteration in the in vitro properties of plasma with respect to (a) cholesterol transport from cultured cells, (b) cholesterol esterification, and (c) transfer of cholesteryl esters from HDL to VLDL-LDL.

Adult↗
PubMed1987

Time-course of alterations of high density lipoproteins (HDL) during thyroxine administration to hypothyroid women.

Serum HDL cholesterol, apolipoproteins AI and AII and post heparin lipolytic activities (PHLA) have been measured in a group of fourteen hypothyroid women without ovarian oestrogen secretion before and during a 2-month thyroxine treatment. The more rapid and consistent observed event was a decrease in apo AI levels (164 +/- 5 vs. 149 +/- 5 mg dl-1, mean +/- SEM, P less than 0.05) correlated (r = 0.79, P less than 0.05) to a slight increment of PHLA. A slight decrease in apo AII concentration was seen only after 5 days (25 +/- 2 vs. 22 +/- 2 mg dl-1, P less than 0.05) and in HDL cholesterol only after 60 days (1.3 +/- 0.6 vs. 1.1 +/- 0.5 mmol 1-1, P less than 0.05). Apo AI, HDL2 and HDL3 cholesterol were measured in another group of seven hypothyroid postmenopausal women before and after a 2-month thyroxine treatment. We observed a decrease in HDL2 cholesterol (1.69 +/- 0.20 vs. 1.17 +/- 0.09 mmol 1-1, P less than 0.02) with no changes in HDL3 cholesterol (0.88 +/- 0.09 vs. 0.99 +/- 0.06 mmol 1-1, NS). The decrease in HDL2 cholesterol correlated (r = 0.72, P = 0.05) with that for apo AI. The differential influence of thyroxine (T4) administration on the major HDL components might reflect changes in HDL composition due to the multiple effects of thyroid hormones on lipid metabolism. It can be hypothesized that the decrease in apo AI and HDL2 cholesterol concentrations are due, at least in part, to the increase in hepatic lipase activity.

Adolescent↗
PubMed1987

High voltage orbital radiotherapy and surgical orbital decompression in the management of Graves' ophthalmopathy.

We report on 2 groups of patients with Graves' ophthalmopathy. A group of 21 patients was treated by high voltage (18 MV) orbital radiotherapy combined with mean doses of corticoids. The results were good or excellent in 12 patients (mean score 6.62 before and 4.0 after, soft tissues greater than proptosis greater than extraocular muscle involvement), without any complications from irradiation. Patients undergoing surgery initially presented less severe symptoms, even 7 patients treated after corticoid and/or radiotherapy failure. The results were satisfactory in all patients (mean score 5.1 before and 2.4 after, proptosis greater than soft tissues greater than extraocular muscle involvement). Both methods showed results within 3 months, and they can be combined.

Eye Diseases↗
PubMed1986

[Comparison between the value of urinary free cortisol and 17-hydroxycorticosteroids for the diagnosis of Cushing's syndrome].

The usefulness for the diagnosis of Cushing's syndrome of urinary free cortisol and urinary 17-hydroxycorticosteroid (17-OHCS) determination was compared by measuring these substances in 17 normal and 28 obese subjects and in 19 patients with established Cushing's syndrome. These measurements were repeated in 16 obese subjects and 11 Cushing's syndrome patients after oral administration of dexamethasone (2 mg/day for 2 days, then 8 mg/day for 2 days). As a group, the patients with Cushing's syndrome had higher (p less than 0.001) excretion rate of both free cortisol and 17-OHCS, but the values observed in this group overlapped with those of normal and obese subjects. The overlap was not significantly different for free cortisol and 17-OHCS excretion. In each obese subject, oral dexamethasone decreased the urinary excretion rate of both free cortisol and 17-OHCS. Seven out of the eleven patients with Cushing's syndrome had no decrease of urinary free cortisol or 17-OHCS, whereas both values were slightly lower in one and decreased to levels similar to those obtained in obese subjects in the three remaining patients. It is concluded that there is no advantage in measuring free cortisol excretion instead of 17-OHCS excretion, either before of after a pituitary-adrenal suppression test, for the diagnosis of Cushing's syndrome.

17-Hydroxycorticosteroids↗
PubMed1986

Pattern of plasma levels of cortisol, dehydroepiandrosterone and pregnenolone sulphate in normal subjects and in patients with homozygous familial hypercholesterolaemia during ACTH infusion.

The aim of this study was to determine whether patients with homozygous familial hypercholesterolaemia (FH) have impaired adrenal cortical function. Plasma levels of cortisol, dehydroepiandrosterone (DHA), pregnenolone sulphate (PS) and DHA sulphate (DHAS) were measured during and 8 h ACTH infusion in six controls and two patients with homozygous FH. The basal PS levels of both patients and the basal DHA level of one were abnormally low for age and pubertal stage. During ACTH infusion we observed in both patients: (1) a mild impairment of control response after sustained stimulation (P less than 0.002); (2) a clear impairment of PS response (values less than 2 SD of those in controls); (3) a clear impairment of DHA response (values less than 2 SD) until 4 h in the boy who was at pubertal stage 4 and whose response could be compared to controls; no increase at all in the affected girl (pubertal stage 2) at a stage where normal subjects respond with significant increase. These results suggest that patients with FH lack cholesterol for corticosteroid biosynthesis under maximal ACTH stimulation and that mild chronic ACTH stimulation due to a deficit in the cholesterol supply to adrenal cells might increase the conversion of delta 5 to delta 4-steroids. They provide further evidence to support the primordial role of low density lipoprotein (LDL)-cholesterol in adrenal steroidogenesis in vivo.

Adrenal Cortex↗
PubMed1986

[Pulmonary metastases in medullary cancers of the thyroid. Study of 4 cases. Originality of the lymphangitic form with amyloid stroma].

We studied the clinical and radiological features of pulmonary metastases present in 4 out of 22 patients with medullary carcinoma of thyroid. Two patients presented with common metastases: macronodules in one, and micronodules in the other one. The other two patients presented initially with reticulonodular perihilar lesions on chest X-ray, leading to the diagnosis of sarcoidosis in both of them. The observation of such pulmonary metastases is original: initially latent, they progress very slowly, and they correspond to a lymphangitic spread of the tumour with amyloid deposition in peribronchovascular structures without alveolar involvement, as shown in one of our cases with pathologic study.

Adult↗
PubMed1986

[New area of endemic goiter : the northeast Bénoué, (North Cameroon)].

Endemic goiter was thought to essentially spread in the southern part of Cameroun. In fact the North-East Benoué (NEB) area also appears to be concerned. We studied 1242 individuals from 5 representative villages. The overall goiter frequency was 28.4%. Study of emigrants showed a spreading of the endemic area towards the boundary part of Tchad. However increase of morbidity was related to the duration of settlement in NEB (18% after 1 year vs 34% after 5 years, p less than 0.01). Samples of urine from one single micturition were kept at 4 degrees C and assayed for iodide within 3 days. The results exhibited marked iodine deficiency (iodide : 9.6 +/- 1.5 micrograms/l; urinary ratio : iodide/creatinine : 17.9 micrograms/l). The way of preserving urine before iodine assay was critical. After 8 days of daylight exposure of the samples at 30 degrees C, the most part of assayable iodine had disappeared. The goitrogenic effect of manioc was weak : there was no relationship between the presence of goiter and the amount of ingested manioc. Concentration of thiocyanates in urine was correlated neither with manioc consumption nor with goiter volume. An automatic classification was obtained by computerization of several parameters. 88% of the patients distributed in 10 groups whose goiter frequencies were markedly different. Because of the well-defined characteristics of each group, it seems possible to perform valid biological or nutritional studies using a limited number of individuals.

Adolescent↗
PubMed1984

Glucose metabolism in experimental hyperthyroidism: intact in vivo sensitivity to insulin with abnormal binding and increased glucose turnover.

The characteristics of the dose response of insulin on the glucose turnover rate and erythrocyte insulin binding parameters were determined in five normal men before and during experimentally induced hyperthyroidism [L-T4 (2 micrograms kg-1 day-1) for 4 weeks with additional L-T3 (1 microgram kg-1 day-1) for the following 3 weeks]. Hyperthyroidism was characterized by significant rises in T3 from 1.92 +/- 0.17 (+/- SEM) to 3.66 +/- 0.17 nmol/liter (P less than 0.01) and resting metabolic rate from 39 +/- 0.7 to 48 +/- 1 watt/m2 (P less than 0.001). While the subjects received a diet adapted to the metabolic rate, blood glucose rose from 3.8 +/- 0.07 to 4.46 +/- 0.11 mmol/liter (P less than 0.05) without a significant change in plasma insulin. During the insulin dose-response study, glucose infusion rates were unaltered by hyperthyroidism, and neither the maximum effect nor the sensitivity to insulin was altered. Glucose turnover rate, measured using [6,6-2H2]glucose as tracer, was determined in the basal state and during the 0.4 mU kg-1 min-1 insulin infusion. In the basal state, it was significantly increased by hyperthyroidism (control, 2.3 +/- 0.1; hyperthyroidism, 3.7 +/- 0.1 mg kg-1 min-1). During the insulin infusion, hepatic glucose production was totally suppressed before T4 and T3 treatment, but was 0.96 +/- 0.39 mg kg-1 min-1 during T4 and T3 treatment. A marked decrease in the insulin binding affinity to erythrocytes was found without a change in the insulin receptor number. In conclusion, glucose metabolism in experimental hyperthyroidism is characterized by 1) increases in basal glucose production and utilization; 2) antagonism between the effect of insulin and hyperthyroidism at the hepatic level; and 3) lack of peripheral insulin resistance in spite of marked alteration in erythrocyte insulin binding affinity.

Adult↗
PubMed1979

[Malignant pheochromocytoma].

The reported incidence of malignant pheochromocytoma varies from series to series. In this series 4 cases (7.2 p. 100) were observed out of a total of 55. In two cases the tumour progressed rapidly but in the other two cases, metastases were detected 3 to 12 years after the apparent cure of a histologically benign pheochromocytoma. The urinary levels of catecholamines and their metabolites gave no indication of the underlying malignancy. The diagnosis was only made from the clinical and radiological detection of metastases (2 hepatic, 2 bone). There is no satisfactory treatment and various therapeutic methods have to be used in succession; surgery for a single metastasis, radiotherapy and antiadrenergic agents to combat clinical manifestations. The natural history of this tumour is relatively long.

Adrenal Gland Neoplasms↗
PubMed1978

Thyroid function and blood pressure in two new strains of spontaneously hypertensive and normotensive rats.

1. The influence of thryoid function on the development of hypertension was studied in strains of spontaneously hypertensive (SH) and normotensive rats. 2. Surgical thyroidectomy decreased systolic blood pressure more markedly in SH rats than in normotensive rats. The effects of oral administration of 5 and 100 micrograms of thyroxine 24 h-1 100 g-1 were studied in the thyroidectomized animals. In the two strains the blood pressure returned to control levels only after administration of the larger dose. 3. The evolution of body weight, total plasma tri-iodothyronine (T3) and tetraiodothyronine (T4) concentrations were followed as a function of age in SH rats and normotensive rats from 5 to 21 weeks. At each age, SH rats showed significantly larger body weight and decreased T4 concentrations. Plasma T3 in SH rats was lower than in normotensive rats until 15 weeks of age, after which the difference was not significant. At 11 weeks, plasms free T3 and T4 concentrations were slightly lower in SH rats than in normotensive rats. 4. The more marked hypotensive effects of surgical thyroidectomy in SH rats cannot be related to increased thyroid function.

Aging↗