Genetic aspects of valvulopathies

Valvular dystrophies due to myxoid degeneration are common and potentially serious cardiac pathologies. They constitute a heterogeneous group of which the most usual is idiopathic mitral valvular prolapse (Barlow's disease). The majority of mitral valvular prolapses are sporadic, but there are several familial forms. Transmission is usually autosomal dominant with incomplete penetrance and variable expression. The first chromosomal location to be identified was on the 16p11-13 chromosome. Since then, two other loci have been identified on the 11p15.4 and 13q31-32 chromosomes. Our team has recently identified the first gene responsible for myxoid valvulopathy linked to the X chromosome, from a large family of 318 members. This is the gene that codes for filamin A, which is a cytoskeleton protein. The frequency of mutations in this gene is still unknown, but out of 7 families in which transmission was compatible with X-linked transmission, mutations were discovered in 4 of the families. Thanks to a genetic epidemiological approach, we have also demonstrated that there are familial forms of aortic stenosis, which are probably common. Identification of the genes implicated in these common forms of valvular pathology is important, as it will allow a better understanding of the pathophysiology of these valvular disorders and could lead to better therapeutic management in the future.     

Prevalence and impact of metabolic syndrome on hospital outcomes in acute myocardial infarction

BACKGROUND: The impact of metabolic syndrome after acute myocardial infarction (AMI) has not yet been studied. In a population-based sample of patients with AMI, we sought to determine the prevalence of metabolic syndrome in patients with AMI, its impact on hospital outcomes, and to assess the relative influence of each of the components of the National Cholesterol Education Program (NCEP) Adult Treatment Panel (ATP) III definition of metabolic syndrome on the risk of death and heart failure. METHODS: A total of 633 unselected, consecutive patients hospitalized with AMI were categorized according to the NCEP ATP III metabolic syndrome criteria (presence of >/=3 of the following: hyperglycemia; triglyceride level >/=150 mg/dL [>/=1.7 mmol/L]; high-density lipoprotein cholesterol level <40 mg/dL [<1.04 mmol/L] in men and <50 mg/dL [<1.30 mmol/L] in women; blood pressure >/=130/85 mm Hg; and waist circumference >102 cm in men or 88 cm in women). RESULTS: Among the 633 patients, 290 (46%) fulfilled the criteria for metabolic syndrome. Patients with metabolic syndrome were older and more likely to be women. Acute myocardial infarction characteristics and left ventricular ejection fraction rates were similar for both groups. In-hospital case fatality was higher in patients with metabolic syndrome compared with those without, as was the incidence of severe heart failure (Killip class >II). In multivariate analysis, metabolic syndrome was a strong and independent predictor of severe heart failure, but not in-hospital death. Analysis of the predictive value of each of the 5 metabolic syndrome components for severe heart failure showed that hyperglycemia was the major determinant (odds ratio, 3.31; 95% confidence interval, 1.86-5.87). CONCLUSIONS: In an unselected population of patients with AMI, the prevalence of metabolic syndrome was high. Metabolic syndrome appeared associated with worse in-hospital outcome, with a higher risk of development of severe heart failure. Among metabolic syndrome components, hyperglycemia was the main correlate of the risk of development of severe heart failure during AMI.     

Electrochemical sensory detection of Sus scrofa mtDNA for food adulteration using hybrid ferrocenylnaphthalene diimide intercalator as a hybridization indicator

In this study, an electrochemical DNA biosensor was developed based on the fabrication of silicon nanowires/platinum nanoparticles (SiNWs/PtNPs) on a screen-printed carbon electrode (SPCE) for the detection of Sus scrofa mitochondrial DNA (mtDNA) in food utilizing a new hybrid indicator, ferrocenylnaphthalene diimide (FND). The morphology and elemental composition of the SiNWs/PtNPs-modified SPCE was analyzed by field emission scanning electron microscopy (FESEM) combined with energy dispersive X-ray spectroscopy (EDX). Cyclic voltammetry (CV) was used to study the electrical contact between the PtNPs and the screen-printed working electrode through SiNWs, while electrochemical impedance spectroscopy (EIS) was used to measure the charge transfer resistance of the modified electrode. The results clearly showed that the SiNWs/PtNPs were successfully coated onto the electrode and the effective surface area for the SiNWs/PtNPs-modified SPCE was increased 16.8 times as compared with that of the bare SPCE. Differential pulse voltammetry used for the detection of porcine DNA with FND as an intercalator confirmed its specific binding to the double-stranded DNA (dsDNA) sequences. The developed biosensor showed a selective response towards complementary target DNA and was able to distinguish non-complementary and mismatched DNA oligonucleotides. The SiNWs/PtNPs-modified SPCE that was fortified with DNA hybridization demonstrated good linearity in the range of 3 × 10⁻⁹ M to 3 × 10⁻⁵ M (R² = 0.96) with a detection limit of 2.4 × 10⁻⁹ M. A cross-reactivity study against various types of meat and processed food showed good reliability for porcine samples.

An electrochemical DNA biosensor was developed based on the fabrication of silicon nanowires/platinum nanoparticles on a screen-printed carbon electrode for the detection of Sus scrofa mitochondrial DNA in food.     

Atrial fibrillation during myocardial infarction with and without ST segment elevation

INTRODUCTION: The occurrence of atrial fibrillation (AF) in the acute phase of myocardial infarction with ST segment elevation is common and responsible for an excess hospital mortality. The aim of this work was to define the incidence, predictive factors, and the prognostic impact of AF during MI with and without raised ST segment in the RICO study. PATIENTS AND METHODS: Between January 2001 and July 2003, 1701 patients were included in this study: 130 (7.6%) had AF in the first 24 hours of management (AF+ group); 1571 (92.4%) remained in sinus rhythm (AF- group). RESULTS: Among the 1701 patients included in this study, 1197 (70.4%) had MI with raised ST and 504 (29.6%) had MI without raised ST. The incidence of AF was identical whatever the type of MI (7.6% with raised ST versus 7.7% without, p=0.334). The presence of Killip class >2 on admission and chronic obstructive pulmonary disease were independent predictive factors for the occurrence of AF (OR=3.84, p=0.007, and OR=2.47, p=0.014 respectively). The presence of AF was significantly associated with the occurrence of ventricular arrhythmia and/or cardiovascular mortality during admission in the non-selected MI population whatever the type of MI (raised ST ; AF+; 34% and AF-; 18%, p<0.01 versus without raised ST; AF+; 36% and AF-; 16%, p = 0.01). CONCLUSION: This study provides evidence that the incidence of AF during the first 24 hours of MI, as well as its poor prognosis, are identical whether or not there is ST segment elevation.     

Unusual clinical presentation in a family with catecholaminergic polymorphic ventricular tachycardia due to a G14876A ryanodine receptor gene mutation

A family was identified, of whom which 11 members were carriers of the G14876A ryanodine 2 receptor mutation. All but 1 were symptomatic at the time of the study. Exercise testing showed bidirectional or polymorphic arrhythmias in 4 patients, whereas in 5 patients, it showed monomorphic or rare minor polymorphic ventricular arrhythmias. Two young patients died suddenly at rest while asleep. This study demonstrates that arrhythmias occurring during exercise stress testing in patients affected by catecholaminergic polymorphic ventricular tachycardia (CPVT) could be minor even in very symptomatic patients. The diagnosis of CPVT must be considered in these patients with a familial history of typical CPVT.     

Seroepidemiology of Hepatitis B virus infection in Saudi children 8 years after a mass hepatitis B vaccination programme

OBJECTIVES: On October 1 1989, a programme was begun in Saudi Arabia in which the HBV vaccine was added as the 'seventh' primary immunogen of the Extended Programme of Immunization (EPI). In 1990, another programme was launched by the Ministry of Health to vaccinate all school children. Eight years after this mass vaccination programme, the efficacy of HBV vaccine was evaluated in a community-based study. METHODS: A community-based study was carried out in Saudi children in urban and rural areas, covering all the regions of Saudi Arabia. After informed consent, blood samples were obtained and tested for HBV markers. RESULTS: Among 4791 vaccinated Saudi children aged 1-12 years, only 15 were found to be HbsAg-positive (0.31%). HbsAg-positivity was 0.16% in children vaccinated at birth compared with 0.7% in those vaccinated at school entry. The overall HbsAg carrier rate dropped from 6.7% in 1989 to 0.3% in 1997 (P<0.00001). Similarly, there was a significant reduction in the prevalence of anti-HBc from 4.2% in 1989 to 0.46% in 1997 (P<0.00001). The overall seroconversion rate to HB vaccine among 4087 Saudi children up to 12 years of age was about 77%. Seroconversion rate in those vaccinated at birth was 77% compared with 71% in those vaccinated at school entry. After 8 years of receiving the third vaccine dose, close to 65% of the children had an anti-HBs titre of more than 10 IU/l compared with about 28% who had an anti-HBs titre of more than 100 IU/l after the same period. CONCLUSION: The result of this study demonstrates the tremendous impact of the mass HB vaccination programme on the seroepidemiology of HBV infection in Saudi Arabia. The ultimate goal of preventing HBV-related chronic liver disease and hepatocellular carcinoma in Saudi Arabia is foreseeable in the near future.     

Double sténose gastrique et duodénale révélant une maladie de Crohn (à propos d’un cas)

Abstract

Gastric and duodenal in Crohn’s disease is rare. We report an exceptional case of double gastric and duodenal stenosis revealing a Crohn’s disease, we define its epidemiological, clinical, therapeutic and evolutive caracteristics.

Case report

patient, 25 years old, followed since 2004 for chronic diarrhea, was wrongly treated for intestinal tuberculosis without clinical improvement, Crohn’s disease was diagnosed on the following arguments.

Clinical

presence of postprandial food vomiting, a feeling of fullness, two episodes of of low abundance hematemesis and epigastric pain.

Endoscopic and histological

an oesogastroduodénale endoscopy showed erythematous gastritis, gastric stenosis, micronodular duodenal mucosa. Gastric biopsy revealed noncaseating granulomas. Colonoscopy was normal. Colonic biopsy found a noncaseating granulomas. Radiology: The upper gastrointestinal transit found a gastric and duodenal stasis and short, regular antral stenosis. The SBFT showed a duodenal stenosis. The patient was treated with corticosteroids, immunosuppressive drugs and proton pump inhibitor with a good clinical and biological evolution.