Implication of non-coding PAX6 mutations in aniridia

There is an increasing implication of non-coding regions in pathological processes of genetic origin. This is partly due to the emergence of sophisticated techniques that have transformed research into gene expression by allowing a more global understanding of the genome, both at the genomic, epigenomic and chromatin levels. Here, we implemented the analysis of PAX6, whose coding loss-of-function variants are mainly implied in aniridia, by studying its non-coding regions (untranslated regions, introns and cis-regulatory sequences). In particular, we have taken advantage of the development of high-throughput approaches to screen the upstream and downstream regulatory regions of PAX6 in 47 aniridia patients without identified mutation in the coding sequence. This was made possible through the use of custom targeted resequencing and/or CGH array to analyze the entire PAX6 locus on 11p13. We found candidate variants in 30 of the 47 patients. 9/30 correspond to the well-known described 3' deletions encompassing SIMO and other enhancer elements. In addition, we identified numerous different variants in various non-coding regions, in particular untranslated regions. Among these latter, most of them demonstrated an in vitro functional effect using a minigene strategy, and 12/21 are thus considered as causative mutations or very likely to explain the phenotypes. This new analysis strategy brings molecular diagnosis to more than 90% of our aniridia patients. This study revealed an outstanding mutation pattern in non-coding PAX6 regions confirming that PAX6 remains the major gene for aniridia.

Treatment of high-grade glioma in children and adolescents

Pediatric high-grade gliomas (HGGs)--including glioblastoma multiforme, anaplastic astrocytoma, and diffuse intrinsic pontine glioma--are difficult to treat and are associated with an extremely poor prognosis. There are no effective chemotherapeutic regimens for the treatment of pediatric HGG, but many new treatment options are in active investigation. There are crucial molecular differences between adult and pediatric HGG such that results from adult clinical trials cannot simply be extrapolated to children. Molecular markers overexpressed in pediatric HGG include PDGFRα and P53. Amplification of EGFR is observed, but to a lesser degree than in adult HGG. Potential molecular targets and new therapies in development for pediatric HGG are described in this review. Research into bevacizumab in pediatric HGG indicates that its activity is less than that observed in adult HGG. Similarly, tipifarnib was found to have minimal activity in pediatric HGG, whereas gefitinib has shown greater effects. After promising phase I findings in children with primary CNS tumors, the integrin inhibitor cilengitide is being investigated in a phase II trial in pediatric HGG. Studies are also ongoing in pediatric HGG with 2 EGFR inhibitors: cetuximab and nimotuzumab. Other novel treatment modalities under investigation include dendritic cell-based vaccinations, boron neutron capture therapy, and telomerase inhibition. While the results of these trials are keenly awaited, the current belief is that multimodal therapy holds the greatest promise. Research efforts should be directed toward building multitherapeutic regimens that are well tolerated and that offer the greatest antitumor activity in the setting of pediatric HGG.

[Flow through an improved ball valve for the heart assist device]

Objective of the present study is the hemodynamic investigation of the fluidmechanics a ball valve developed for ventricular assist devices with improved parameters. The flow was investigated using Digital Particle Image Velocimetry with an enlarged model of the valve (2.8:1). The flow was recorded using a high speed video camera with 250 fps and analyzed by a cross-correlation method implemented in the software DaVis by LaVision. The results confirmed the improvement of the ball valve performed by a numerical study. The flow separations on the ball valve housing observed in the first design version was eliminated in the final design of the novel valve. Hence a valve of this design applied in ventricular assist devices can be expected to have a lower rate of thromboembolic complications.

[Determining wall shear stress in artificial blood pumps of heart assist devices]

The walls in blood pumps are made of artificial material and thus are thrombogenic to a lesser or larger degree. Also the flow plays a role: a blood flow with no flow separations and stagnation zones is required to avoid the generation of thrombi. A precondition for solving this problem is the assessment of the wall shear rate. However this parameter is difficult to assess because of the deformability of the walls and the pulsation of the flow. Two methods are proposed to estimate the wall shear stress in bloodpumps. The paint erosion method allows a characterisation of the flow near the wall. The second method is a special development of standard Particle Image Velocimetry (PIV). A vector field of the flow close to the wall results. Both methods should permit the assessment of the wall shear stress in bloodpumps.

[Management of malnutrition in peritoneal dialysis]

Peritoneal dialysis is associated with nutritional abnormalities due to peritoneal glucose absorption and protein or amino acid losses into the dialysate. Nutritional assessment, every four months, is essential, based on body composition, anthropometric measurements, clinical characteristics, biochemical parameters and dietary survey. Thus 1.2 g to 1.3 protein/kg/day and 30 to 35 kcal/kg/day energy intake may be required. Oral, parenteral or intraperitoneal amino acids supplementation can improve the nutritional status in peritoneal dialysis patients.

[Prevalence and significance of the C virus antibody in chronic hepatopathy not related to B virus in alcoholics]

The presence of antibody to the hepatitis C virus was determined in 254 alcoholic patients with non-B chronic hepatitis and a titre of antinuclear antibodies of 1/40 or lower. Alcoholic hepatitis was present in 12 patients, steatohepatitis in 20, active chronic hepatitis in 22, cirrhosis in 181, and hepatocarcinoma in 19. Twenty patients had previously received blood transfusion alone or during surgery, 49 had undergone previous surgery without transfusion, a clinical episode of hepatitis could be traced in 14, 4 patients were drug addicts, 41 had received blood transfusion after the diagnosis was made, and 128 presented with alcoholism alone. Anti-hepatitis C antibody was found in 20 out of 2,000 blood donors (1%) in our hospital. Anti-hepatitis C antibody was found in 87 patients (34.2%) in our series, a figure unaltered by past medical history. Patients with anti-HC antibody had higher levels of AST, ALT, total proteins, gamma-globulin, and IgG. The incidence of active chronic hepatitis was higher among patients with anti-HC antibody, whereas the incidence of steatohepatitis was higher among patients without anti-HC. Regarding findings on liver biopsy, the incidence of anti-HC was significantly higher (p less than 0.001) among patients with active chronic hepatitis (72.7%) than in any other group; no significant differences were found between patients with cirrhosis (33.3%), hepatocarcinoma (31.5%), steatohepatitis (15%), or alcoholic hepatitis (16.7%). Among HBsAg-negative patients, the incidence of anti-HC was similar between those with (39.7%) and without other serum markers of HB (32.9%).(ABSTRACT TRUNCATED AT 250 WORDS)

[Serum and bronchial concentrations of netilmicin during its continuous intratracheal administration]

Respiratory tract infections in intensive care units have a high fatality rate, perhaps as a result of the poor diffusion into bronchial secretions of aminoglucosides given by a systemic route. Endotracheal administration of aminoglycosides has been advocated but the optimal dosage remains to be determined. To investigate this problem we studied 13 patients free of renal failure and 6 patients with renal failure. Netilmicin was given by continuous endotracheal infusion in a daily dosage of 3 to 30 mg/kg. A good correlation was found between infused doses and serum concentrations; very high bronchial secretion concentrations were consistently found. There is a significant risk of accumulation in patients with renal failure. The characteristics of the respiratory tract secretions had no influence on the passage of netilmicin into the bloodstream. The dosages we advocate on the basis of our results are 8 mg/kg/day in patients free of renal failure and 4 mg/kg/day in patients with renal failure; serum netilmicin concentrations should not exceed 1 microgram/ml.

Endoscopic retrograde cholangiopancreatography in Echinococcus (hydatid) cysts of the liver

Endoscopic retrograde cholangiopancreatography (ERCP) was carried out on 19 patients with hydatid cyst of the liver, either before or after operation. Cholangiographic findings included biliary tract obstruction in 8 cases, intrinsic compression in 4 cases, laminated membranes or daughter cysts in the biliary tree in 3 cases, perforation into the biliary tract in 2 cases, stricture in the biliary ductal system in 1 case, and biliary fistula in the remaining case. Biliary tract obstruction was secondary to chemical cholangitis by formalin in 2 patients. ERCP is a useful procedure in patients with suspected intrabiliary rupture or when symptoms occur after surgical removal of the cyst.