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Biomedical subjects

G Turpin

Publications and source records attributed to G Turpin.

At least 73 records · Page 4Linked to original sources
PubMed1997

[Relationship between iron status and diet in 410 hyperlipidemic patients].

In order to examine the influence of a low-fat diet on iron status, we carried out a study which involved 410 out-patients with hyperlipidaemia, i.e. 256 men and 154 women. Serum iron was positively correlated with protein intake (p = 0.11; p < 0.05) and transferrin saturation was inversely correlated with fat intake (p = - 0.12; p < 0.05). A positive iron balance (serum iron > 27 mumol/l and transferrin saturation > 45%) was found in 1.6% of the male subjects, a frequency which could be explained by the presence of the hemochromatosis genes. A negative iron balance (serum iron < 10 mumol/l and tranferrin saturation < 15%) was found in 13.7% for women aged 21-49 yr, 3.7% for women aged 50-77 yr and 3.5% for men aged 21-77 yr. We found no association between low-fat diet and iron deficiency. Men with iron deficiency had 12% decrease in total calorie intake compared to the Recommended Dietary Allowance. Our results do not provide evidence that hypolipidemic diet is associated with a high frequency of iron deficiency.

Adult↗
PubMed1997

[Lipid risk factors of atherosclerosis: who, when, how to treat?].

Hyperlipidemia, particularly hypercholesterolemia, is a well established risk factor for cardiovascular disease, specially coronary heart disease. Lipid-lowering therapies are associated with a reduction in cardiovascular morbidity and mortality in secondary as well as primary prevention. A precise lipid pattern is necessary before any treatment. The target level depends on the clinical data and associated cardiovascular risk factors. Diet is the first step approach and should always be continued. Cholestyramine and statins are the treatments of choice in case of hypercholesterolemia (type IIa). In case of isolated or associated hypertriglyceridemia (types IV and IIb) fibrates are the most efficient. No treatment is really efficient on Lp(a) level. A good observance is required for a lifelong treatment.

Child↗
PubMed1996

[Hyperlipidemia in pregnancy].

Hyperlipidemia is one of the most striking modification of biological parameters occurring during normal pregnancy. Hypertriglyceridemia is the most prominent feature, with a less dramatic increase of total cholesterol levels. Besides these quantitative changes, most lipoproteins undergo qualitative modification throughout pregnancy such as triglyceride enrichment of the particles. Kinetics and magnitude of plasma lipids changes have been well recognized, but the mechanisms, metabolic fate and impact on the pathogenesis of cardiovascular disease are not totally unravelled. The primary modulators are estrogens, insulin and lipoprotein lipase. Hyperlipidemia is a result of the metabolic adaptation of the maternal organism to pregnancy allowing to save glucose and energy for the fetus, reversible within a few weeks in postpartum. However some have suggested a trend toward an increased risk for coronary disease after multiple pregnancies. In case of preexisting hyperlipidemia, whether familial or not-primary or secondary, pregnancy presents an additional challenge. Except from exceptional complications, dietary counselling will be the only treatment, under a close follow-up.

Female↗
PubMed1996

[Characteristic pathological associations in multiple endocrine neoplasia type 1].

OBJECTIVES: Multiple endocrine neoplasia type 1 (MEN 1) is an inherited disorder characterised by slow progressing tumors of the parathyroids, of the endocrine pancreas and of the anterior pituitary. A genetic locus predisposing to this disease has been localised on chromosome 11. Predictive diagnosis of carriers of the defective gene is possible in families using genetic markers at this locus. However, this analysis presupposes a precise identification of affected subjects. Moreover, expression of the disease may vary from one family to the other. The aim of the present study was to define the typical clinical features of the syndrom. METHODS: We assessed retrospectively 26 cases of MEN 1 identified during 20 years in the same medico-surgical center. Among 11 men and 15 women, all those who had a genealogical investigation had a positive family history of MEN 1. RESULTS: Bifocal and trifocal tumors were the main patterns of associations, and were diagnosed at a mean age of 48.6 years. Parathyroid involvement was most frequent and earliest (96% of cases). The second most frequent was pancreatic involvement (69.2% of cases) predominantly manifesting with gastrinomas (N = 13). Multifocal tumors were usually diagnosed before or within 5 years following diagnosis of the first tumor. Among pituitary tumors one case of meningioma was observed, a feature not reported previously. An asymptomatic adrenal involvement was observed in about 1/3 of cases. Other silent tumors (euthyroid nodules, lipomas) were also noted. CONCLUSION: These data suggest that the clinical presentation and course of MEN 1 is homogeneous and are in agreement with the hypothesis of a recessive tumor-suppressor gene expressed in specific endocrine cell lines, suggesting that careful family studies should be conducted when a case of MEN 1 is diagnosed to facilitate early carrier detection among relatives.

Adult↗
PubMed1996

[Lipoprotein lipase: a multifunctional enzyme in lipoprotein metabolism].

Lipoprotein lipase (LPL) is a rate-limiting enzyme for the hydrolysis of triglycerides. Recently new insights into non-enzymatic functions have emerged. Complete lipoprotein lipase deficiency associated with chylomicronemia is an uncommon (1/10(6) in the general population) autosomal recessive disorder caused by many different lipoprotein lipase gene mutations and is characterized by high fasting plasma triglyceride levels, that can be complicated with acute pancreatitis. To date, about sixty gene mutations have been described throughout the world. Conversely to the homozygous state, the heterozygous state predisposes to a lipid profile that may be atherogenic evenly frequent (approximately 1/500) in the general population. These new clinical and biological insights reinforce the multifunctional role of lipoprotein lipase.

Acute Disease↗
PubMed1996

Efficacy and safety of ciprofibrate in hyperlipoproteinaemias.

Ciprofibrate is an effective treatment for three main types of atherogenic hyperlipoproteinaemia: type IIa hypercholesterolaemia, type IIb combined hyperlipidaemia, and type IV hypertriglyceridaemia. In type IIa hypercholesterolaemia, administration of 100 mg/day of ciprofibrate, to approximately 3000 patients, decreased total cholesterol (TC), triglycerides, apolipoprotein B (apo B) and low-density lipoprotein (LDL) cholesterol. Levels of apolipoproteins in high-density lipoprotein (HDL) cholesterol and apolipoprotein AI (apo A-I) were increased. Administration of the same dose of ciprofibrate, to approximately 3500 patients with type IIb combined hyperlipidaemia, had a marked cholesterol- and triglyceride-lowering effect, in addition to producing a decrease in LDL cholesterol and apo B, and an increase in apo A-I. TC levels were also decreased in type IV hypertriglyceridaemia following administration of 100 mg/day of ciprofibrate to 800 patients. The decrease in TC levels was attributable to a decrease in triglyceride levels and an increase in HDL cholesterol levels. The pharmacokinetics, mechanism of action and safety of ciprofibrate treatment are also discussed.

Animals↗
PubMed1996

Men treated with hypolipidaemic drugs complain more frequently of erectile dysfunction.

The objective of this study was to assess whether there is an association between impotence and treatment with hypolipidaemic drugs. We asked patients referred to a lipid clinic for primary hyperlipidaemia whether they were complaining of erectile dysfunction. All the patients with a previous cardiovascular history were excluded. The main cardiovascular risk factors and the treatments currently being taken were carefully recorded to analyse their association with erectile dysfunction. The population consisted of two groups (treatment group and control) of 339 age-matched men (mean age: 48 +/- 9.5 years). Our results revealed that there were more impotent men in the group of patients treated with hypolipidaemic drugs (12% vs. 5.6%, P = 0.0029). Multivariate analysis showed that erectile dysfunction was dependent on treatment with fibrate derivatives (odds ratio: 1.46; 1.27-1.68) and statins (odds ratio: 1.51; 1.26-1.80). We conclude that erectile dysfunction is a frequent disorder in hyperlipidaemic men. Our results suggest that this symptom could be a side-effect of hypolipidaemic drugs. If further studies confirm our data, the search for the mechanism and the consequences of this possible side-effect will be useful and important.

Adult↗
PubMed1996

Fenofibrate reduces plasma cholesteryl ester transfer from HDL to VLDL and normalizes the atherogenic, dense LDL profile in combined hyperlipidemia.

The effect of fenofibrate on plasma cholesteryl ester transfer protein (CETP) activity in relation to the quantitative and qualitative features of apoB- and apoA-I-containing lipoprotein subspecies was investigated in nine patients presenting with combined hyperlipidemia. Fenofibrate (200 mg/d for 8 weeks) induced significant reductions in plasma cholesterol (-16%; P < .01), triglyceride (-44%; P < .007), VLDL cholesterol (-52%; P = .01), LDL cholesterol (-14%; P < .001), and apoB (-15%; P < .009) levels and increased HDL cholesterol (19%; P = .0001) and apoA-I (12%; P = .003) levels. An exogenous cholesteryl ester transfer (CET) assay revealed a marked decrease (-26%; P < .002) in total plasma CETP-dependent CET activity after fenofibrate treatment. Concomitant with the pronounced reduction in VLDL levels (37%; P < .005), the rate of CET from HDL to VLDL was significantly reduced by 38% (P = .0001), whereas no modification in the rate of cholesteryl ester exchange between HDL and LDL occurred after fenofibrate therapy. Combined hyperlipidemia is characterized by an asymmetrical LDL profile in which small, dense LDL subspecies (LDL-4 and LDL-5, d = 1.039 to 1.063 g/mL) predominate. Fenofibrate quantitatively normalized the atherogenic LDL profile by reducing levels of dense LDL subspecies (-21%) and by inducing an elevation (26%; P < .05) in LDL subspecies of intermediate density (LDL-3, d = 1.029 to 1.039 g/mL), which possess optimal binding affinity for the cellular LDL receptor. However, no marked qualitative modifications in the chemical composition or size of LDL particles were observed after drug treatment. Interestingly, the HDL cholesterol concentration was increased by fenofibrate therapy, whereas no significant change was detected in total plasma HDL mass. In contrast, the HDL subspecies pattern was modified as the result of an increase in the total mass (11.7%) of HDL2a, HDL3a, and HDL3b (d = 1.091 to 1.156 g/mL) at the expense of reductions in the total mass (-23%) of HDL2b (d = 1.063 to 1.091 g/mL) and HDL3c (d = 1.156 to 1.179 g/mL). Such changes are consistent with a drug-induced reduction in CETP activity. In conclusion, the overall mechanism involved in the fenofibrate-induced modulation of the atherogenic dense LDL profile in combined hyperlipidemia primarily involves reduction in CET from HDL to VLDL together with normalization of the intravascular transformation of VLDL precursors to receptor-active LDLs of intermediate density.

Adult↗
PubMed1996

[Chemodectoma secreting carotid glomus: characteristics and contribution of magnetic resonance imaging. Apropos of 2 cases].

Two cases of carotid glomus chemodectomas with production of catecholamines are reported. The place of chemodectomas among the neuroendocrine tumors called paragangliomas is recalled. Chemodectomas only very infrequently produce catecholamines (1 to 10%). Magnetic resonance imaging is superior to computerized tomography and metaiodobeuzylguanidine scintigraphy in the detection and the characterization of adrenal and extra-adrenal functioning paragangliomas of the orthosympathic system. Few data are available for the imaging of functioning parasympathetic paragangliomas (chemodectomas). The two case reports illustrate the contribution of the magnetic resonance imaging in the detection and the characterization of chemodectomas.

Adult↗
PubMed1995

[Atherogenicity of low-density lipoproteins (LDL). A problem of quantity or quality?].

The relationship between elevated plasmatic LDL and increased risk of coronary artery disease is definitively established. However the qualitative aspect of the particles also appear to play a significant role: a structural heterogeneity within the LDL particles themselves has been recognized for a number of years. Multiple subclasses have been characterized in several populations of normal and hyperlipidaemic subjects. Some of these subclasses are linked with an atherogenic potential, this is the case for the smaller and the more dense of the particles, defined as the phenotype B. Epidemiological studies have consistently shown an association of this phenotype with an increased risk of coronary artery disease, and various reports have linked it with clinical and angiographic indices of the disease. However, these studies do not allow for causality, and after adjustment for the plasma TG level LDL subclasses distribution is not an independent predictor of coronaropathy anymore. The underlying mechanisms leading to the association are not yet established, but it is possible that small dense LDL are per se atherogenic. Considerable evidence is now available to support some of the hypothesis: denser LDL have a lower affinity for the LDL BE receptor, are more succeptible to oxidative damage, and may have modified interaction with various components of the arterial wall. Moreover several authors have shown that a number of lipid lowering drugs, like fibrates, could normalize to a significant extent the plasma profile of LDL as a result of preferential reduction in the elevated levels of the denser more atherogenic subspecies.

Arteriosclerosis↗
PubMed1995

[Granular cell tumors. Rare tumors of the neurohypophysis].

Granular cell tumours of neurohypophysis are rare. These tumours are more often encountered as incidental autopsy findings seen in up to 17% of unselected adult autopsy cases. There are few reports of parasellar granular cell tumours large enough to cause symptoms. We present three cases of neurohypophysis granular cell tumour and a review of the literature. In one patient, the asymptomatic granular cell tumour was incidentally discovered at surgical removal of a corticotroph microadenoma. The remaining 2 patients had a symptomatic tumour which caused neurological symptoms such as visual disturbance and headaches and endocrine disorders such as hypopituitarism or hyperprolactinaemia. In these 2 cases, computerized tomography showed a well-circumscribed, contrast-enhanced, intrasellar and suprasellar mass. Magnetic resonance imaging demonstrated an isointense gadolinium-enhanced mass in T1-weighted images. Transsphenoidal partial resection was performed and histology was interpreted as a granular cell tumour. The immunohistochemical study was positive for glial fibrillary acidic protein (GFAP) and neuron specific enolase (NSE) in 1 of the 2 tumours and positive for S100 protein and vimentin in both tumours but negative for CD68. The histogenesis of neurohypophysis granular cell tumours is still controversial but ultrastructural and immunohistochemical studies support the theory that they may arise from pituicytes, the glial cells of neurohypophysis. Management of these benign, slow-growing, tumours is based mainly on neurosurgical resection. Data from the literature do not support a beneficial effect of postoperative radiation therapy on postoperative recurrences.

Adult↗
PubMed1995

[Substitutive hormonal treatment of menopause. Effects on lipoprotein metabolism].

A number of epidemiological studies have clearly shown that post-menopausal women on hormone therapy (which tends to simulate normal ovarian production) have a reduced risk of cardiovascular disease (coronary heart disease, stroke and thrombotic events). In fact most of the studies have involved equine oestrogen (Premarin) taken orally. The effects of oestrogens and the progestins depend on the type of administration (oral or percutaneous administration) and the variety of the drug chosen and finally is also dose dependent. The most favourable effect is obtained in normolipidaemic women with the combination of conjugated oestrogens given orally and a non-androgenic progestins. Such therapy is associated with an increase in HDL-cholesterol and a decrease in LDL-cholesterol. HDL subfraction analysis shows that HDL2 are the main species involved in this increase. The mechanism of action of oestrogens and progestins can be summarized as follows: oestrogens stimulate hepatic triglyceride secretion, inhibit the action of hepatic lipase, augment LDL breakdown via the cellular receptor apo B-E and may decrease LDL oxidability and Lp(a) levels. Although several points remain obscure, we may notice that most of studies show that the atherogenic profile of the women who are currently being treated tends to improve.

Cardiovascular Diseases↗
PubMed1995

Estrogens and progestins in postmenopausal women: influence on lipid parameters and cardiovascular risk.

Postmenopausal women are 2-3 times more likely to have a heart attack than premenopausal women. According to the results of the Framingham study, angina is one of the main manifestations of coronary heart disease in women, whereas myocardial infarction and sudden death are more frequent in men. Cigarette smoking, high blood pressure and hypercholesterolemia are major risk factors for coronary heart disease in both men and women, while diabetes mellitus and hypo-high-density lipoproteinemia are more clearly associated with cardiovascular disease in women than in men. Endogenous and exogenous hormones may be a major determinant of the cardiovascular risk in women. Premenopausal women have a considerably lower incidence of coronary heart disease than postmenopausal women, and estrogen therapy is associated with a reduced risk in the latter. Part of this protective effect seems to be due to the influence of estrogen therapy on lipoprotein metabolism, i.e. a decrease in LDL cholesterol and an increase in HDL cholesterol. Progestins, to an extent which depends on their androgenic potency, have the opposite effects. A large study (the Postmenpausal Estrogen Progestin Intervention Trial) has been launched to test the effect of the estrogen-progestin combination on various cardiovascular risk factors.

Cardiovascular Diseases↗
PubMed1995

Familial acromegaly: a specific clinical entity--further evidence from the genetic study of a three-generation family.

Familial acromegaly is a very rare inherited disorder, characterized by the clustering within a single family of several related cases with somatotroph adenomas and acromegaly. The causes of these dominantly inherited pituitary tumours remain unknown. Although these families have a clinical presentation distinct from that of multiple endocrine neoplasia type 1 (MEN-1), the question of this syndrome as being linked to the MEN-1 locus has remained open. Our aim was to study a three-generation family with cases of acromegaly in a mother and her son, to explore better the clinical presentation of the disease, its pattern of inheritance and to test the hypothesis of a genetic linkage to the MEN-1 locus using closely linked polymorphic genetic markers. The refined analysis of 15 unaffected relatives revealed miscellaneous non-specific endocrine dysfunctions and the presence of multiple lipomata, as noted previously in some cases. Moreover, the notion of acromegalo-gigantism in the maternal grandmother and an incomplete penetrance appeared even more typical, suggesting that familial acromegaly is a specific clinical entity. Finally, under the hypotheses assumed for segregation analysis, no clinical, biological or genetic evidence of linkage to the MEN-1 locus could be retained in this family. However, these conclusions were limited because of incomplete penetrance and uncertain definition of the carrier status. Therefore, we conclude that further identification of the genetic predisposition to familial acromegaly might be obtained from the combined molecular genetic analysis of several families presenting with the same clinical features.

Acromegaly↗
PubMed1995

[Genetic aspects of primary atherogenic dyslipoproteinemia].

Large progress have been made in the last 15 years about knowledge of genetic of atherogenic dyslipoproteinemias. The genes of apolipoproteins, lipoprotein receptors and enzymes of lipoprotein metabolism are now located and their structures are known. Many gene defects are described and are responsible of definite diseases such as familial hypercholesterolemia, familial dysbetalipoproteinemia, familial hypoalphalipoproteinemia. Beside this pure genetic disorders, other atherogenic dyslipoproteinemias are result of interactions of genetic and environmental factors. This new physio-pathological approach gives a better comprehension of the clinical features than phenotype classification based on plasma cholesterol and triglycerides levels and lipoprotein electrophoretic pattern.

Humans↗
PubMed1994

[Elevation of lipoprotein(a) levels in patients following transplantation for ischemic cardiopathy].

OBJECTIVES: Increased levels of serum lipoprotein (a) in heart transplant patients has been recently shown to be related to early recurrence of coronary artery disease. In order to evaluate the effect of the ischaemic origin of the heart disease we compared lipoprotein (a) levels observed in heart transplant patients who underwent transplantation due to ischaemic heart disease and non-obstructive cardiomyopathy with those in healthy control subjects. METHODS: Serum levels lipoprotein (a) were measured in 62 cardiac transplantation recipients who had a hyperlipidemia. The results were compared with those of 212 control subjects matched for age and who were referred for hyperlipidemia. RESULTS: In the whole population 40 patients had been operated on for coronary heart disease and 22 for idiopathic cardiomyopathy. The two populations did not differ with regard to their cardiovascular risk factors except for the smoking status. The mean Lp(a) values were significantly higher in the subjects with coronary heart disease as compared with those with idiopathic cardiomyopathy (0.33 +/- 0.24 and 0.21 +/- 0.17 mg/dl respectively; p < 0.05). The latter were not different from the control group (0.22 +/- 0.19 mg/ml). We did not find any difference between the two populations concerning the drugs taken by the patients (especially cyclosporine), LDL-cholesterol, creatinine, fasting blood glucose and TSH. CONCLUSION: Our data confirm the relation between coronary atherosclerosis and high lipoprotein (a) levels.

Adult↗