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Biomedical subjects

F R Heller

Publications and source records attributed to F R Heller.

At least 19 recordsLinked to original sources
PubMed2003

Impact of genetic defects on coronary atherosclerosis in patients suspected of having familial hypercholesterolaemia.

BACKGROUND: In the present study we assessed whether the presence of genetic mutations typical of familial hypercholesterolaemia (FH) was associated with greater atherosclerosis in the coronary vessels in patients with severe hypercholesterolaemia and a family history of early cardiovascular disease. MATERIALS AND METHODS: Two hundred and thirty-five patients selected for having severe hypercholesterolaemia and a family history of cardiovascular disease were classified as FH (57 men and 38 women) or non-FH (84 men and 56 women) according to a genetic analysis of the LDL-R or ApoB genes. Coronary atherosclerosis was evaluated by performing a thoracic CT scan and exercise stress testing. RESULTS: Familial hypercholesterolaemia individuals had a significantly higher prevalence of coronary calcification than the non-FH patients from among both the men (OR = 3.90; 95% CI 1.86-8.19; P < 0.001) and the women (OR = 2.34; 95% CI 1.01-5.48; P = 0.05). In exercise stress testing, ECG abnormalities suggestive of cardiac ischaemia were found with a higher prevalence in the FH patients than the non-FH patients from among both the men (OR 6.15; 95% CI 2.16-17.5; P < 0.001) and the women (OR 4.76; 95% CI 0.91-24.6; P = 0.06). All differences were statistically significant after adjusting for age and cholesterol and for most classical risk factors that differed between the FH and non-FH groups. CONCLUSION: Among patients with severe hypercholesterolaemia and a family history of early cardiovascular disease, the presence of a genetically ascertained FH is associated with a higher prevalence of coronary artery calcifications and a positive exercise stress test. These results suggest that despite a similar phenotype, patients carrying mutations suggestive of FH may have a greater cardiovascular risk than patients without these mutations.

Adult↗
PubMed2001

The use of Achilles tendon ultrasonography for the diagnosis of familial hypercholesterolemia.

Differentiating FH from other causes of hypercholesterolemia has important clinical and therapeutic implications but is often not possible by standard clinical criteria. As accumulation of cholesterol in tendon is generally considered as pathognomonic of FH, we evaluated the sensitivity and specificity of clinical and ultrasonographic tendon characteristics using the data of 127 genetically ascertained FH and 160 controls with various lipid profiles. Upon clinical examination, none of the controls and 29% of FH individuals (17% FH women and 38% FH men) presented with xanthomata in Achilles tendons, but no female and only 6% of male FH patients also showed xanthomata in the extensor tendon of the hand. Amongst all possible quantitative parameters (thickness, breadth, section and roundness) of Achilles tendon (AT) measured by ultrasonography, the thickness presented the best receiver operating curves. AT thickness above 5.8 mm was the most useful threshold for diagnosis of FH, procuring sensitivity of 75% and specificity of 85%. Analysis of variation of AT thickness with age and sex indicated that this clinical criterion performed better in females older than 45 and in males under 45. In patients carrying the APOB-R3500Q mutation, AT-thickness appeared significantly less important compared with those carrying LDLR mutations. In conclusion, this study recommends identification of possible FH individuals amongst hypercholesterolemic patients using a criteria of AT-thickness over 5.8 mm eventually associated with a specific genetic test for APOB-R3500Q mutation.

Achilles Tendon↗
PubMed2001

Impact of genetic defects on atherosclerosis in patients suspected of familial hypercholesterolaemia.

BACKGROUND: Among patients with severe hypercholesterolaemia and a family history of early cardiovascular disease, we assessed whether patients with mutations of low-density lipoprotein (LDL) receptor and apolipoprotein B genes related to familial hypercholesterolaemia (FH) have a different degree of atherosclerosis than those without such mutations. METHOD: In our lipid clinics, 273 patients were selected on the basis of a severe hypercholesterolaemia (cholesterol above 95th percentile) and a family history of early cardiovascular disease. By molecular genetic test, 122 patients were classified as FH. Atherosclerosis was evaluated by the ultrasonographic measurement of intima-media thickness (IMT) in the carotid and femoral arteries. RESULT: Despite the fact that non-FH individuals had a higher prevalence of obesity, hypertension, diabetes and hypertriglyceridaemia, FH individuals had significantly greater carotid and femoral IMT than non-FH patients: difference between carotid and femoral IMT, respectively, 0.19 mm (95% CI, 0.08-0.29; P < 0.001) and 0.20 mm (95% CI, 0.09-0.35; P = 0.001), respectively. These differences remained statistically significant after adjustment for the various risk factors as well as in sub-analysis restricted to the patients with LDL-cholesterol between 240 and 300 mg dL-1 (range with similar distribution in the two groups). When classified according to the severity of their mutations, FH individuals with null LDL receptor allele tended to have thicker carotid IMT than FH individuals carrying the LDL receptor-defective allele. CONCLUSION: Among patients with severe hypercholesterolaemia and a family history of early cardiovascular disease, the presence of a genetically ascertained FH is associated with a higher degree of atherosclerosis. This suggests that molecular genetic identification of FH may be helpful to evaluate better the coronary heart disease risk in these patients.

Adult↗
PubMed1999

Hypoxic hepatitis caused by acute exacerbation of chronic respiratory failure: a case-controlled, hemodynamic study of 17 consecutive cases.

Out of a prospective series of 142 consecutive episodes of hypoxic (ischemic) hepatitis (HH), we identified 17 episodes associated with an acute exacerbation of chronic respiratory failure (CRF) without left cardiac failure. In the aim to evaluate the role of arterial hypoxemia in the pathogenesis of HH associated with respiratory failure, these 17 episodes of HH (study group) were hemodynamically compared with a control group of 17 episodes of HH associated with congestive heart failure (CHF) (control group 1) and a group of 16 episodes of acute respiratory failure (ARF) not complicated by HH (control group 2). Arterial hypoxemia was significantly more severe in the study group (arterial blood tension in O2 [PaO2], 34 mm Hg) than in control group 1 (PaO2, 70 mm Hg; P <.0001) and control group 2 (PaO2, 45.5 mm Hg; P =.002). The role of arterial hypoxemia, however, appeared weakened by comparable degrees of systemic hypotension and liver passive congestion in episodes of HH associated with CRF and episodes of HH associated with CHF. Finally, the causative role of arterial hypoxemia emerged from hemodynamic measurements of cardiac index (CI), systemic vascular resistances (SVR), and oxygen transport: systemic hypotension in HH associated with CHF (control group 1) was the result of a fall in CI (median, 2. 33 L/min. m2; range, 1.21-3.14 L/min. m2) associated with high SVR (median, 2,492 dyn. s/cm5. m2; range, 1,382-4,053 dyn. s/cm5. m2), whereas in HH associated with respiratory failure (study group), systemic hypotension was the result of a fall in SVR (median, 1,053 dyn. s/cm5. m2; range, 646-3,148 dyn. s/cm5. m2), resulting in high CI (median, 4.23 L/min. m2; range, 1.9-5.32 L/min. m2) (P =.0087 and. 0038 for cardiac index and SVR, respectively). Moreover, measurements of oxygen transport in patients with HH associated with respiratory failure showed low values of O2 delivery (DO2) (median, 376 mL/min. m2; range, 253-427 mL/min. m2) as a result of extreme arterial hypoxemia despite high CI. In conclusion, these hemodynamic results and additional measurements of hepatic blood flow (HBF) by the method of galactose clearance at a low concentration suggest that in the setting of HH associated with respiratory failure, the liver is not "ischemic," despite hypotension, but rather "hypoxic" as a result of the combination of severe arterial hypoxemia and elevated central venous pressure (CVP).

Aged↗
PubMed1999

Prevention of cardiovascular events by hypolipidemic therapy evidence-based medicine criteria.

Studies in which hypolipidemic therapy were used for preventing cardiovascular diseases are analyzed on the basis of the number of patients to treat to avoid a clinical event, one of the most accepted evidence-based medicine criteria. The benefit of treatment appears to be related to the risk profile of the population and to the reduction of LDL-Cholesterol concentration but not to the type of therapy. Total mortality is decreased only when statins are used. Special groups of patients (women, aged patients, diabetics) also appear to benefit from the treatment.

Age Factors↗
PubMed1998

LDL oxidation: therapeutic perspectives.

The peroxidation step of lipid transormation is considered to be essential in the pathogenesis of atherosclerosis. Although data concerning the mechanisms by which lipid peroxidation occurs in vivo are scarce, several lines of evidence suggest that some endogenous and exogenous compounds with antioxidant activity could have some beneficial effects in the prevention of atherosclerosis. Ascorbic acid (vitamin C) and alpha-tocopherol (vitamin E) act as the most important hydrophilic and lipophilic antioxidants, respectively in vivo. Accordingly, animal and human studies suggest that these compounds may have some preventive effect against the development of clinical coronary heart disease. Many plant phenols and flavonoids may be important dietary antioxidants and it has been speculated that these compounds in red wine or in the Mediterranean diet could explain the 'French paradox'. Several studies show that antioxidants such as probucol and butylated hydroxytoluene can inhibit development of atherosclerotic lesions in Watanabe and cholesterol-fed rabbits. Some drugs such as beta-blockers, calcium antagonists, hypolipodemic drugs,...appear to have at least in vitro antioxidant effects but the clinical relevance of these properties remains unkonwn. Moreover, some interventions aimed to decrease the LDL-oxidative susceptibility have not been shown to attenuate atherogenesis when cholesterol levels remain markedly elevated.

Animals↗
PubMed1997

Hypoxic hepatitis caused by severe hypoxemia from obstructive sleep apnea.

Cardiac and circulatory failure are the main causes of hypoxic hepatitis. In a prospective study of 142 cases of hypoxic hepatitis collected during a 10-year period, we encountered two cases resulting from extreme arterial hypoxemia without congestive heart failure, cor pulmonale, or circulatory failure. Both patients were morbidly obese women admitted to the intensive care unit for carbonarcosis. Oxygen arterial saturation was very low, less than 35% in both patients, but there was no history of cardiac or respiratory failure and no clinical evidence of circulatory failure. Cardiac function, evaluated by isotopic scintigraphy, was normal. After the episode of hypoxic hepatitis, a diagnosis of obstructive sleep apnea was made clinically and confirmed by performing nocturnal oximetry, which showed multiple episodes of oxygen desaturation in both patients. Polysonography could be performed in one case and was typical of obstructive sleep apnea. Liver ischemia is the main mechanism leading to hypoxic hepatitis. More recently, the role of passive congestion of the liver has been emphasized. Arterial hypoxemia, however, is generally considered to be a minor factor. Our two cases support the hypothesis that severe arterial hypoxemia may lead to hypoxic hepatitis even in the absence of cardiac and circulatory failure.

Aged↗
PubMed1997

High prevalence of a novel mutation in the exon 4 of the low-density lipoprotein receptor gene causing familial hypercholesterolemia in Belgium.

In a cohort of 70 unrelated patients living in Southern Belgium with autosomal dominantly inherited hypercholesterolemia, 11 had a hitherto undescribed mutation in exon 4. It consisted in a C-->A mutation at nucleotide 366, resulting in a stop codon at residue Cys122. This C122X mutation is expected to cause a class I receptor defect. The biochemical and clinical data collected from the patients carrying the mutation were consistent with a severe form of familial hypercholesterolemia (FH). Some differences between generations were noted. Amongst the C122X carriers, those born after 1926 had cardiovascular complications earlier than those born before 1926. This raises the possibility that changes in environmental factors during the course of the century have had an unfavorable impact on the prognosis of the disease. The mutation was found in 16% of the suspected FH patients and less frequently (less than 3% of suspected FH) in Northern Belgium. The haplotype of the chromosomes carrying the mutation was the same in all C122X families, but extensive genealogical studies failed to reveal a common ancestor. We conclude that C122X is an old and common cause of FH in Belgium. Screening for this mutation may be useful in the diagnosis of FH in Belgium.

Adult↗
PubMed1996

An improved method for detection of low density lipoprotein receptor defects in human T lymphocytes.

Familial hypercholesterolemia (FH) results from an inherited functional defect of the low density lipoprotein (LDL) receptor and is complicated by premature atherosclerosis. FH diagnosis is obtained by sophisticated techniques or is suggested by clinical criteria. We have developed a technique based on flow cytometry for the measurement of DiI-labeled LDL uptake in human peripheral blood T lymphocytes left for 2 days in a lipoprotein-deficient culture medium. Flow cytometry allowed us to discriminate the uptake of DiI-LDL by T lymphocytes subpopulation from the uptake by the whole mononuclear population using a T cell-specific anti-CD3 antibody. The method appeared to be highly specific for the receptor-mediated pathway of LDL uptake as DiI-LDL uptake was inhibited in the presence of a 10-fold excess of unlabeled LDL and by EDTA. A good relationship was found between the uptake of DiI-LDL and 125I-labeled LDL degradation. The test was applied in three groups of patients: patients with normal cholesterol levels, patients with heterozygous FH, and patients with high cholesterol levels but without clinical criteria of FH. The mean fluorescence intensities were 23.1 +/- 8.9, 6.3 +/- 1.7, and 17.1 +/- 3.5 (mean +/- standard deviation), respectively. The ability to measure the fluorescence in T lymphocytes improved the discrimination between FH and non-FH subjects when compared with values obtained from the whole mononuclear cell population. These results suggest that our method could be useful for LDL receptor defects screening.

Adolescent↗
PubMed1995

[Lipoprotein (a) in liver diseases. Correlation between low levels and liver function].

OBJECTIVES: To analyze the role of the liver function on the serum levels of lipoprotein(a) (Lp(a)), a lipoprotein considered to be a risk factor for atherosclerosis. METHODS: To measure the Lp(a) levels in patients with liver disease (n = 68) due to various causes and in patients with no liver disease and of similar age and sex-ratio (n = 62) and to analyze the relationship between Lp(a) levels on one hand and liver function and lipid and apoprotein levels on the other hand. RESULTS: Patients with liver disease had significantly lower levels of Lp(a). Lp(a) levels were significantly lower in patients with more severe liver disease (Child Turcotte classification) and significantly correlated with liver function tests, in particular those related to the microsomal function and the synthetic capacity of the liver (albumin, coagulation tests, apoprotein A-II). In patients with liver disease, mean Lp(a) levels were not significantly different between those with and those without chronic alcohol intake. CONCLUSIONS: Patients with liver disease have low levels of Lp(a) that are related to reduced synthetic capacity of this organ and are not linked to a specific cause of liver disease, in particular excess alcohol intake.

Adult↗
PubMed1994

Variable regions of chromosome 11 loss in different pathological tissues of a patient with the multiple endocrine neoplasia type I syndrome.

Multiple endocrine neoplasia type 1 (MEN1) is an autosomal dominant inherited disorder characterized by nodular proliferation of the parathyroid glands and tumors of the anterior pituitary gland, the endocrine pancreas, and the neuroendocrine cell system of the gut. Loss of the putative tumor suppressor effect of the MEN1 gene is probably responsible for the development of MEN1-associated tumors. We report here a genetic study of a female MEN1 patient with the association of nodular hyperplasia of two parathyroid glands, an insulinoma, multiple duodenal gastrinomas, a prolactinoma, and a gastric carcinoid. We performed loss of heterozygosity (LOH) studies of chromosome 11 on all affected tissues except the insulinoma. Allelic losses of chromosome 11 were detected in several tumors, but the chromosomal regions of LOH were different, suggesting that different somatic mutational events are involved in the pathogenesis of these tumors. LOH of chromosome 11 was also detected in the prolactinoma of this patient, which indicates that the MEN1 gene has a tumor suppressor effect in the pituitary.

Calcium↗
PubMed1993

[Genetic hemochromatosis and mixed gonadal dysgenesis].

We report a case of association between genetic haemochromatosis and mixed gonadal dysgenesis. To our knowledge, this case is the first reported in the literature. We discuss the mechanisms of hypogonadism observed in this patient.

Adult↗
PubMed1993

Ischemic hepatitis in cirrhosis. Rare but lethal.

We report two cases of ischemic hepatitis in patients with alcoholic cirrhosis. In both, hepatic ischemia was induced by hemorrhagic shock and severe sepsis. Despite control of the bleeding and restoration of normal hemodynamics, liver failure deteriorated to hepatic coma and death in both cases. Ischemic hepatitis occurred in 1.5% of 130 consecutive cases of cirrhosis admitted for hemorrhage on our medical intensive care unit. Although cirrhotic patients run an increased risk of ischemic hepatitis, our experience and our review of the literature indicate that this condition is rare in these patients.

Aged↗
PubMed1993

Serum lipoprotein(a) in patients with diabetes mellitus.

OBJECTIVE: To investigate subjects with different types of diabetes mellitus regarding their serum levels of lipoprotein(a). High serum Lp(a) concentration is associated with a high risk of coronary heart disease. Diabetic patients are prone to developing coronary heart disease. RESEARCH DESIGN AND METHODS: The subjects were 66 type I diabetic patients, 100 type II diabetic patients treated with diet alone or diet combined with oral hypoglycemic agents, and 46 insulin-requiring type II diabetic patients. Subjects were compared with 142 nondiabetic outpatients. RESULTS: Subjects with insulin-requiring type II diabetes mellitus were found to have an increase both in serum Lp(a) concentration and in prevalence of serum Lp(a) concentration > 30 mg/dl compared with the other groups of diabetic patients and nondiabetic control subjects. A nonsignificant increase in the prevalence of coronary heart disease was also found in insulin-requiring type II diabetic patients. The levels of serum concentrations of Lp(a) were not significantly related to the degree of glycemic control, duration of diabetes, presence of macrovascular disease, or intake of female hormone therapy. High levels of Lp(a) in this group of diabetic patients could not be explained by the presence of albuminuria. CONCLUSIONS: Insulin-requiring type II diabetic patients have high levels of Lp(a). Chronic hyperinsulinemia might be an eventual causal factor.

Aged↗