Déficit familial de la LCAT au Québec : description d’une première mutation et contribution du génotype de l’APO E sur le phénotype lipoprotéique

Le déficit familial de LCAT (FLD) est une maladie caractérisée par un défaut de l’activité de l’enzyme lecithin:cholesterol acyltransferase (LCAT). Ce défaut résulte en une concentration plasmatique de C-HDL extrêmement basse, des opacités cornéennes prématurées, la présence d’anémie, de protéinurie et d’insuffisance rénale. Nous avons identifié les premiers patients canadiens-français atteints de déficit familial de LCAT. Deux frères, présentant les signes classiques de FLD étaient homozygotes pour une nouvelle mutation du gène de la LCAT: la mutation c.102delG. Cette mutation se traduit au niveau protéique par un changement du cadre de lecture au niveau du codon His35 et l’insertion d’un codon stop en position 61 entraînant une abolition de l’activité LCAT in vitro et in vivo. La présence de cette mutation cause une réduction importante du C-HDL chez les hétérozygotes (22%) et les homozygotes (88%) ainsi qu’une baisse du C-LDL chez les hétérozygotes (35%) et les homozygotes (58%). De plus, le profil lipidique différait de manière importante entre les deux frères atteints de FLD qui présentaient des génotypes APOE différents. Nous suggérons que APOE est un gène qui modifie le phénotype du FLD et pourrait expliquer l’hétérogénéité des profils lipidiques chez les patients atteints de FLD. Nos résultats suggèrent également que l’association du génotype LCAT-/- a un allèle APOE ε2 est un nouveau mécanisme conduisant à la dysbétalipoproteinemie. Finalement nous avons montré des différences importantes dans les sous-populations des HDL chez les deux sujets atteints de FLD. Le porteur de l’allèle APOE ε2 présentait une proportion beaucoup plus importante de HDL immatures (preβ discoïdaux) par rapport a son frère (77.9% vs. 31.0%).Familial LCAT deficiency (FLD) is a disease characterized by a defect in the enzyme lecithin:cholesterol acyltransferase (LCAT) resulting in low HDL-C, premature corneal opacities, anaemia as well as proteinuria and renal failure. We have identified the first French Canadian kindred with familial LCAT deficiency. Two brothers, presenting classical signs of FLD, were shown to be homozygous for a novel LCAT mutation. This c.102delG mutation occurs at the codon for His35 and causes a frameshift that stops transcription at codon 61 abolishing LCAT enzymatic activity both in vivo and in vitro. It has a dramatic effect on the lipoprotein profile, with an important reduction of HDL-C in both heterozygotes (22%) and homozygotes (88%) and a significant decrease in LDL-C in heterozygotes (35%) as well as homozygotes (58%). Furthermore, the lipoprotein profile differs markedly between the two affected brothers who had different APOE genotypes. We propose that APOE could be an important modifier gene explaining heterogeneity in lipoprotein profiles observed among FLD patients. Our results suggest that a LCAT-/- genotype associated with an APOE ε2 allele could be a novel mechanism leading to dysbetalipoproteinemia. Finally we have identified major differences in the HDL sub-populations of both subjects affected by FLD. The carrier of the APOE ε2 allele presented a much higher proportion of immature HDL particles (discoid preβ) compared to his brother (77.9% vs. 31.0%)

L’influence des relations familiales et sociales sur la consommation de médicaments psychotropes chez les personnes âgées

Les psychotropes occupent le deuxième rang dans la consommation de médicaments chez les personnes âgées. L'objectif de cette étude est de vérifier un modèle explicatif de la consommation de psychotropes dans cette population. Notre principale hypothèse est que la qualité des relations qu'entretient une personne âgée avec autrui, et particulièrement avec ses enfants, a une influence directe sur son bien-être psychologique, lequel a une influence directe sur la non-consommation de psychotropes. Une enquête a été réalisée auprès d'un échantillon de 500 personnes âgées de 65 à 84 ans, vivant à domicile. Au cours des trois mois précédant l'entrevue, 31,8 % des répondants ont consommé des psychotropes. Les données empiriques n'ayant pas permis de vérifier le modèle théorique retenu, des analyses multivariées ont conduit à l'élaboration d'un modèle explicatif de la consommation qui met en évidence que le bien-être psychologique et la santé sont les meilleurs prédicteurs de cette consommation. Un bien-être psychologique élevé diminue la consommation alors qu'un mauvais état de santé l'augmente. Les relations sociales influencent directement le bien-être psychologique alors que les relations familiales ont un effet de moindre importance. Le modèle explicatif proposé explique 13 % du phénomène de la consommation de psychotropes chez les personnes âgées.Psychotropic drugs are the second most commonly used medication by Quebec's elderly. The objective of this study is to test a theoretical model of psychotropic drug use in the elderly. The principal hypothesis is that the quality of relationships the elderly person has with others, particularly with his or her children, has a direct influence on his or her psychological well-being, which, in turn, directly affects the consumption of psychotropic agents. A survey was conducted on a sample of 500 elderly people, aged 65-84 years, living at home. 31.8% of the respondents used psychotropic drugs during the three-month period preceding the interview. Path analysis led to the elaboration of a modified model for the consumption of psychotropic drugs by the elderly which indicates that the best predictors of consumption are both the psychological well-being and the state of health of the individual. More elevated is the psychological well-being, less is the consumption of psychotropic drugs, whereas poor health condition increases it. The quality of an individual's social relationships has a direct influence on his or her psychological well-being, whereas family relationships are of lesser importance. Our model accounts for 13% of the predictors of psychotropic consumption by the elderly

Regulation of poly(A) binding protein function in translation: Characterization of the Paip2 homolog, Paip2B

The 5′ cap and 3′ poly(A) tail of eukaryotic mRNAs act synergistically to enhance translation. This synergy is mediated via interactions between eIF4G (a component of the eIF4F cap binding complex) and poly(A) binding protein (PABP). Paip2 (PABP-interacting protein 2) binds PABP and inhibits translation both in vitro and in vivo by decreasing the affinity of PABP for polyadenylated RNA. Here, we describe the functional characteristics of Paip2B, a Paip2 homolog. A full-length brain cDNA of Paip2B encodes a protein that shares 59% identity and 80% similarity with Paip2 (Paip2A), with the highest conservation in the two PABP binding domains. Paip2B acts in a manner similar to Paip2A to inhibit translation of capped and polyadenylated mRNAs both in vitro and in vivo by displacing PABP from the poly(A) tail. Also, similar to Paip2A, Paip2B does not affect the translation mediated by the internal ribosome entry site (IRES) of hepatitis C virus (HCV). However, Paip2A and Paip2B differ with respect to both mRNA and protein distribution in different tissues and cell lines. Paip2A is more highly ubiquitinated than is Paip2B and is degraded more rapidly by the proteasome. Paip2 protein degradation may constitute a primary mechanism by which cells regulate PABP activity in translation

Low density lipoprotein delays clearance of triglyceride-rich lipoprotein by human subcutaneous adipose tissue

A floral capital, detail; The Pavilion of Trajan (also Kiosk of Trajan) is a rectangular building that has fourteen columns with beautifully carved floral capitals that once supported a wooden roof. Only two of the screen walls between the columns are completed. They show the Emperor Trajan burning incense before Isis and Osiris and offering wine to Isis and Horus. The Kiosk is often ascribed to Trajan, but might well have been built earlier than this, possibly during the reign of Augustus. This unfinished building is one of the most popular monuments of Philae and in ancient times was probably intended to serve as a ceremonial landing stage for the island temple. Source: Tour Egypt; http://www.touregypt.net/ (accessed 1/18/2008

Familial Hypercholesterolemia-Risk-Score: A New Score Predicting Cardiovascular Events and Cardiovascular Mortality in Familial Hypercholesterolemia

International audienceObjective: Familial hypercholesterolemia (FH) is associated with a high risk of premature atherosclerotic cardiovascular disease (ASCVD). However, this risk is highly heterogeneous and current risk prediction algorithms for FH suffer from limitations. The primary objective of this study was to develop a score predicting incident ASCVD events over 10 years in a large multinational FH cohort. The secondary objective was to investigate the prediction of major adverse cardiovascular events and cardiovascular mortality using this score. Approach and Results: We prospectively followed 3881 patients with adult heterozygous FH with no prior history of ASCVD (32 361 person-years of follow-up) from 5 registries in Europe and North America. The FH-Risk-Score incorporates 7 clinical variables: sex, age, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, hypertension, smoking, and lipoprotein (a) (Lp(a)) with a Harrell C-index for 10-year ASCVD event of 0.75, which was superior to the SAFEHEART-RE (Spanish Familial Hypercholesterolemia Cohort; 0.69). Subjects with an elevated FH-Risk-Score had decreases in 10-year ASCVD-free survival, 10-year major adverse cardiovascular event-free survival, and 30-year survival for CV mortality compared with the low-risk group, with hazard ratios of 5.52 (3.94–7.73), 4.64 (2.66–8.11), and 10.73 (2.51–45.79), respectively. The FH-Risk-Score showed a similar performance in subjects with and without an FH-causing mutation. Conclusions: The FH-Risk-Score is a stronger predictor of future ASCVD than the SAFEHEART-RE and was developed in FH subjects with no prior cardiovascular event. Furthermore, the FH-Risk-Score is the first score to predict CV death and could offer personalized cardiovascular risk assessment and treatment for patients with FH. Future studies are required to validate the FH-Risk-Score in different ethnic groups

Effect of the LDL receptor mutation type on incident major adverse cardiovascular events in familial hypercholesterolaemia

International audienceAbstract Aims Patients with familial hypercholesterolaemia (FH) are at increased risk of cardiovascular disease (CVD) due to extremely high circulating LDL cholesterol (LDL-C) concentrations. Our objective was to study the effect of the type of LDL receptor (LDLR) mutation on the incidence of major adverse cardiovascular events (MACEs). Methods and results This was a multinational prospective cohort study, which included patients with heterozygous FH aged 18–65 years, without a prior history of CVD, and carrying a pathogenic or likely pathogenic variant in the LDLR gene. A total of 2131 patients (20 535person-years of follow-up) were included in the study, including 1234 subjects carrying a defective mutation in the LDLR and 897 subjects carrying a null mutation. During the follow-up, a first MACE occurred in 79 cases (6%) in the defective group and in 111 cases (12%) in the null group. The mean baseline LDL-C concentration was 17% higher in the null group than in the defective group (7.90 vs. 6.73 mmoL/L, P < 0.0001). In a Cox regression model corrected for traditional cardiovascular risk factors, the presence of a null mutation was associated with a hazard ratio of 2.09 (1.44–3.05), P = 0.0001. Conclusion Carriers of a null mutation have an independent ∼2-fold increased risk of incident MACE compared with patients carrying a defective mutation. This study highlights the importance of genetic screening in FH in order to improve patient care

Validation of the <scp>Fatty Liver Index</scp> for identifying non‐alcoholic fatty liver disease in a Kenyan population

AbstractBackground and AimFatty Liver Index (FLI) is a simple clinical scoring system estimating non‐alcoholic fatty liver disease (NAFLD). It is validated in European‐descent and Asian populations, but not in sub‐Saharan Africans. The aim of this study is to evaluate the validity of the FLI for predicting NAFLD in a population from Kenya.MethodsParticipants were recruited from a community‐based study conducted in Kenya. NAFLD was diagnosed using hepatic ultrasonography. Clinical, anthropometrical, biochemical and lifestyle data were obtained. The accuracy and cut‐off point of the FLI to detect NAFLD were evaluated by area under the receiver operator characteristic curve and the maximum Youden index analysis.ResultsA total of 640 participants (94 with NAFLD) were included. Mean age was 37.4 ± 0.4 years and 58.7% were women. Mean body mass index (BMI) was 22.3 ± 0.2 kg/m2 and waist circumference (WC) 79.1 ± 0.4 cm. A total of 15 (2.3%) participants were diagnosed with type 2 diabetes and 65 (10.2%) with obesity (BMI ≥ 30 kg/m2). AUROC of FLI for predicting NAFLD was 0.80 (95% CI 0.74–0.85), which was significantly higher compared to individual components gamma‐glutamyl transferase and triglycerides (p &lt; 0.05), but not compared to anthropometric parameters BMI (AUROC of 0.83, 95% CI 0.79–0.88) and WC (AUROC of 0.81, 95% CI 0.76–0.87).ConclusionsFLI is a simple valid scoring system to use in rural and urban Kenyan adults. However, this index might not be superior to BMI or WC to predict NAFLD, and those measurements might therefore be more appropriate in limited settings.</jats:sec