In vitro prediction of stop-codon suppression by intravenous gentamicin in patients with cystic fibrosis: a pilot study

BACKGROUND: Cystic fibrosis (CF) is caused by mutations in the gene encoding the cystic fibrosis transmembrane conductance regulator (CFTR) protein, which acts as a chloride channel activated by cyclic AMP (cAMP). The most frequent mutation found in 70% of CF patients is F508del, while premature stop mutations are found in about 10% of patients. In vitro aminoglycoside antibiotics (e.g. gentamicin) suppress nonsense mutations located in CFTR permitting translation to continue to the natural termination codon. Pharmacologic suppression of stop mutations within the CFTR may be of benefit to a significant number of patients. Our pilot study was conducted to determine whether intravenous gentamicin suppresses stop codons in CF patients and whether it has clinical benefits. METHODS: A dual gene reporter system was used to determine the gentamicin-induced readthrough level of the most frequent stop mutations within the CFTR in the French population. We investigated readthrough efficiency in response to 10 mg/kg once-daily intravenous gentamicin perfusions in patients with and without stop mutations. Respiratory function, sweat chloride concentration, nasal potential difference (NPD) and CFTR expression in nasal epithelial cells were measured at baseline and after 15 days of treatment. RESULTS: After in vitro gentamicin incubation, the readthrough efficiency for the Y122X mutation was at least five times higher than that for G542X, R1162X, and W1282X. In six of the nine patients with the Y122X mutation, CFTR immunodetection showed protein at the membrane of the nasal epithelial cells and the CFTR-dependent Cl(- )secretion in NPD measurements increased significantly. Respiratory status also improved in these patients, irrespective of the gentamicin sensitivity of the bacteria present in the sputum. Mean sweat chloride concentration decreased significantly and normalised in two patients. Clinical status, NPD and sweat Cl(- )values did not change in the Y122X patients with no protein expression, in patients with the other stop mutations investigated in vitro and those without stop mutations. CONCLUSION: Suppression of stop mutations in the CFTR gene with parenteral gentamicin can be predicted in vitro and is associated with clinical benefit and significant modification of the CFTR-mediated Cl(- )transport in nasal and sweat gland epithelium

Impact of metabolic syndrome on the outcomes of superficial femoral artery interventions

BackgroundMetabolic syndrome (MetSyn) is an epidemic in the United States and is associated with early onset of atherosclerosis, increased thrombotic events, and increased complications after cardiovascular intervention. MetSyn is found in ∼50% of patients with peripheral vascular disease. However, its impact on peripheral interventions is unknown. The aim of this study is to determine the outcomes of superficial femoral artery (SFA) interventions in patients with and without MetSyn.MethodsA database of patients undergoing endovascular treatment of SFA disease between 1999 and 2009 was retrospectively queried. MetSyn was defined as the presence of ≥3 of the following criteria: blood pressure ≥130 mm Hg/≥85 mm Hg; triglycerides ≥150 mg/dL; high-density lipoprotein ≤50 mg/dL for women and ≤40 mg/dL for men; fasting blood glucose ≥110 mg/dL; or body mass index ≥30 kg/m2. Kaplan-Meier survival analyses were performed to assess time-dependent outcomes. Factor analyses were performed using a Cox proportional hazard model for time-dependent variables.ResultsA total of 1018 limbs in 738 patients (64% male, average age 67 years) underwent endovascular treatment for symptomatic SFA disease with 45% of patients meeting the criteria for MetSyn. MetSyn patients were more likely to be female (P = .001), to present with critical ischemia (rest pain/tissue loss: 55% MetSyn vs 45% non-MetSyn; P = .001), have poorer ambulatory status (P = .001), and have more advanced SFA lesions (TransAtlantic Inter-Society Consensus II C/D: 51% vs 11%; P = .001) and worse tibial runoff (P = .001). MetSyn patients required more complex interventions (P = .0001). There was no difference in mortality and major adverse cardiac events, but systemic complications (4% vs 1%; P = .001) and major adverse limb events (12% vs 7%; P = .0009) were significantly higher in the MetSyn group. Immediate postprocedural hemodynamic improvement, resolved or improved symptoms, and restoration of impaired ambulation were equivalent in both groups. Early failure (<6 months) was more common in those with MetSyn. At 5 years, primary, assisted primary, and secondary patencies were not affected by the presence of MetSyn. The presence of MetSyn was associated with a decrease in clinical efficacy, decreased freedom from recurrent symptoms, and decreased freedom from major amputation at 5 years.ConclusionsMetSyn is present in nearly half of the patients presenting with SFA disease. These patients present with more advanced disease and have poorer symptomatic and functional outcomes compared with those patients without MetSyn

Mitchell-Riley Syndrome : Improving Clinical Outcomes and Searching for Functional Impact of RFX-6 Mutations

Aims/HypothesisCaused by biallelic mutations of the gene encoding the transcription factor RFX6, the rare Mitchell-Riley syndrome (MRS) comprises neonatal diabetes, pancreatic hypoplasia, gallbladder agenesis or hypoplasia, duodenal atresia, and severe chronic diarrhea. So far, sixteen cases have been reported, all with a poor prognosis. This study discusses the multidisciplinary intensive clinical management of 4 new cases of MRS that survived over the first 2 years of life. Moreover, it demonstrates how the mutations impair the RFX6 function. MethodsClinical records were analyzed and described in detail. The functional impact of two RFX6(R181W) and RFX6(V506G) variants was assessed by measuring their ability to transactivate insulin transcription and genes that encode the L-type calcium channels required for normal pancreatic beta-cell function. ResultsAll four patients were small for gestational age (SGA) and prenatally diagnosed with duodenal atresia. They presented with neonatal diabetes early in life and were treated with intravenous insulin therapy before switching to subcutaneous insulin pump therapy. All patients faced recurrent hypoglycemic episodes, exacerbated when parenteral nutrition (PN) was disconnected. A sensor-augmented insulin pump therapy with a predictive low-glucose suspension system was installed with good results. One patient had a homozygous c.1517T>G (p.Val506Gly) mutation, two patients had a homozygous p.Arg181Trp mutation, and one patient presented with new compound heterozygosity. The RFX6(V506G) and RFX6(R181W) mutations failed to transactivate the expression of insulin and genes that encode L-type calcium channel subunits required for normal pancreatic beta-cell function. Conclusions/InterpretationMultidisciplinary and intensive disease management improved the clinical outcomes in four patients with MRS, including adjustment of parenteral/oral nutrition progression and advanced diabetes technologies. A better understanding of RFX6 function, in both intestine and pancreas cells, may break ground in new therapies, particularly regarding the use of drugs that modulate the enteroendocrine system.Peer reviewe

Diagnostic performance of FibroTest, SteatoTest and ActiTest in patients with NAFLD using the SAF score as histological reference

BACKGROUND: Blood tests of liver injury are less well validated in non‐alcoholic fatty liver disease (NAFLD) than in patients with chronic viral hepatitis. AIMS: To improve the validation of three blood tests used in NAFLD patients, FibroTest for fibrosis staging, SteatoTest for steatosis grading and ActiTest for inflammation activity grading. METHODS: We pre‐included new NAFLD patients with biopsy and blood tests from a single‐centre cohort (FibroFrance) and from the multicentre FLIP consortium. Contemporaneous biopsies were blindly assessed using the new steatosis, activity and fibrosis (SAF) score, which provides a reliable and reproducible diagnosis and grading/staging of the three elementary features of NAFLD (steatosis, inflammatory activity) and fibrosis with reduced interobserver variability. We used nonbinary‐ROC (NonBinAUROC) as the main endpoint to prevent spectrum effect and multiple testing. RESULTS: A total of 600 patients with reliable tests and biopsies were included. The mean NonBinAUROCs (95% CI) of tests were all significant (P < 0.0001): 0.878 (0.864–0.892) for FibroTest and fibrosis stages, 0.846 (0.830–0.862) for ActiTest and activity grades, and 0.822 (0.804–0.840) for SteatoTest and steatosis grades. FibroTest had a higher NonBinAUROC than BARD (0.836; 0.820–0.852; P = 0.0001), FIB4 (0.845; 0.829–0.861; P = 0.007) but not significantly different than the NAFLD score (0.866; 0.850–0.882; P = 0.26). FibroTest had a significant difference in median values between adjacent stage F2 and stage F1 contrarily to BARD, FIB4 and NAFLD scores (Bonferroni test P < 0.05). CONCLUSIONS: In patients with NAFLD, SteatoTest, ActiTest and FibroTest are non‐invasive tests that offer an alternative to biopsy, and they correlate with the simple grading/staging of the SAF scoring system across the three elementary features of NAFLD: steatosis, inflammatory activity and fibrosis

La sous-traitance internationale

Bismuth Jean-Louis. La sous-traitance internationale. In: Droit international privé : travaux du Comité français de droit international privé, 6e année, 1984-1985. 1986. pp. 23-80

Diabète de la mucoviscidose (développement, mécanismes et conséquences)

Le diabète est fréquent et apparaît précocement chez les patients atteints de mucoviscidose. Il est associé à une détérioration de l'état nutritionnel et respiratoire. Objectifs : Mieux décrire l'histoire naturelle, les mécanismes et les conséquences du diabète chez les patients atteints de mucoviscidose, de l'enfance à l'âge adulte. Méthodes : Cinq cent dix sept hyperglycémies provoquées par voie orale (HGPO) ont été réalisées chez 237 enfants atteints de mucoviscidose (109 garçons, 128 filles ; 12 +- 5,6 ans), suivis entre 1988 et 2005 à l'hôpital Necker-Enfants Malades. Les données anthropométriques, biologiques (HBA1c, formule sanguine, vitesse de sédimentation), immunologiques (ICA) et génétiques (HLA, génotype CFTR), ainsi que les événements majeurs (transplantation, décès) ont été recueillis. La fonction b pancréatique a été estimée par des rapports insuline/glucose dérivés des données de l'HGPO (Aire sous la courbe, II30-0 /G30, HOMA-b). La sensibilité à l'insuline a été estimée en utilisant le modèle homéostatique HOMA-S. La progression des anomalies de la tolérance glucidique (intolérance au glucose, diabète à l'HGPO, traitement par insuline) a été évaluée par une analyse pour données censurées ; les taux de transplantations pulmonaires et de décès par une analyse de survie. Résultats : L'intolérance au glucose apparaît précocement (20% à l'âge de 10 ans), le risque cumulé augmente à 50% à l'âge de 15 ans, 75% à 20 ans et 82% à 30 ans. Le risque de diabète est > 20% à 15 ans, 45% à 20 ans et 70% à 30 ans ; celui de traitement par insuline est de 30% à 20 ans et 40% à 30 ans. Ces anomalies tendent à être plus précoces chez les filles. La précocité d'apparition des anomalies de la tolérance glucidique est associée à une mortalité accrue et à un taux plus important de transplantation pulmonaire. L'aire glycémique est inversement corrélée à l'indice de masse corporelle et à la taille. Le diabète est associé à une diminution de tous les indices de sécrétion d'insuline, l'intolérance au glucose à une diminution de la phase précoce de sécrétion d'insuline ( II30-0 /G30). On ne retrouve pas de corrélation avec l'indice de sensibilité à l'insuline HOMA-S, mais l'inflammation est associée à une diminution de la sensibilité à l'insuline et à une détérioration de la tolérance glucidique. Conclusion : Le diabète de la mucoviscidose est principalement dû à un déficit de sécrétion d'insuline. Il est extrêmement fréquent tôt dans la vie chez ces patients et est associé à une altération de l'état nutritionnel et à un taux accru d'insuffisance respiratoire terminale et de décèsPARIS6-Bibl.Pitié-Salpêtrie (751132101) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF