A new mechanism for exchange processes observed in the compounds [M(η-C_5H_5)_2(exo-η-RCH = CH_2)H], M = Nb and Ta

Dynamic n.m.r. studies of the exchange processes in the complexes [M(η-C_5H_5)(exo-η-RCH=CH_2)H], M = Nb, Ta, lead to the proposal of a new mechanism involving intermediates with agostic bonding

Recanalization of obstructed metallic uncovered biliary stent using endobiliary radiofrequency ablation

International audienc

Relationship Between the Expression of O-Methylguanine-DNA Methyltransferase (MGMT) and p53, and the Clinical Response in Metastatic Pancreatic Adenocarcinoma Treated with FOLFIRINOX

BACKGROUND: To date, no predictive biomarker for the efficacy of FOLFIRINOX in metastatic pancreatic adenocarcinoma has been demonstrated. Deficiency in O-methylguanine-DNA methyltransferase (MGMT) has been associated with a therapeutic response in endocrine tumors of the pancreas and the lack of expression of protein 53 (p53) could interfere with the action of MGMT. OBJECTIVE: The aim of our study was to assess the prevalence of MGMT and p53 in patients with metastatic pancreatic adenocarcinoma treated with FOLFIRINOX as a first-line treatment and to investigate their association with therapeutic response and survival. PATIENTS AND METHODS: The immunohistochemical expression of MGMT was recorded as present or absent and the expression of p53 was semi-quantitatively scored in 30 patients with metastatic pancreatic adenocarcinoma, at Angers Hospital in France between September 2011 and June 2015. Clinical and radiologic data were collected retrospectively. RESULTS: The presence or absence of MGMT expression entailed no significant differences in response rate. Median values of progression-free survival (PFS) and overall survival (OS) were lower in patients with MGMT expression, but sample size is too small to conclude that there is a statistically significant difference. No significant relationship for response rate and PFS was observed in relation with p53 expression. By contrast, patients with a strong tumor expression of p53 had a significantly lower OS compared to patients with no or weak expression of the protein (p = 0.027). There was a positive correlation between the expression of p53 and MGMT (p = 0.08). CONCLUSIONS: These preliminary findings suggest that for patients treated with FOLFIRINOX as a first-line treatment for metastatic pancreatic adenocarcinoma, the immunohistochemical evaluation of MGMT could not predict the clinical outcome; however, the survival was not significant probably because of the under-powered study (due to small sample size). A strong tumor expression of p53 is associated with a poor prognosis of OS

Screening of esophageal varices by esophageal capsule endoscopy: results of a French multicenter prospective study

BACKGROUND AND STUDY AIM: Esophageal video capsule endoscopy (ECE) is a new technique that allows examination of the esophagus using a noninvasive approach. The aim of this study was to compare ECE with esophagogastroduodenoscopy (EGD) for the diagnosis of esophageal varices in patients with cirrhosis. PATIENTS AND METHODS: A total of 330 patients with cirrhosis and with no known esophageal varices were prospectively enrolled. Patients underwent ECE first, followed by EGD (gold standard). The endoscopists who performed EGD were blind to the ECE result. Patient satisfaction was assessed using a visual analog scale (maximum score 100). RESULTS: A total of 30 patients were excluded from the analysis because they did not undergo any endoscopic examinations. Patients (mean age 56 years; 216 male) had mainly alcoholic (45 %) or viral (27 %) cirrhosis. The diagnostic indices of ECE to diagnose and correctly stage esophageal varices were: sensitivity 76 % and 64 %, specificity 91 % and 93 %, positive predictive value 88 % and 88 %, and negative predictive value 81 % and 78 %, respectively. ECE patient satisfaction scored significantly higher than EGD (87 ± 22 vs. 58 ± 35; P < 0.0001). CONCLUSIONS: ECE was well tolerated and safe in patients with liver cirrhosis and suspicion of portal hypertension. The sensitivity of ECE is not currently sufficient to replace EGD as a first exploration in these patients. However, due to its excellent specificity and positive predictive value, ECE may have a role in cases of refusal or contraindication to EGD. ECE might also improve compliance to endoscopic follow-up and aid important therapeutic decision making in the prophylaxis of bleeding. TRIAL REGISTRATION: EudraCT (ID RCB 2009-A00532-55) and ClinicalTrials.gov (NCT00941421)

A structural model of a P450-ferredoxin complex from orientation-selective double electron-electron resonance spectroscopy

This research was supported by the Engineering & Physical Sciences Research Council (EPSRC) and the Biotechnology & Biological Sciences Research Council (BBSRC), UK (EP/D048559). AMB and EOJD were supported by graduate studentships from the BBSRC (BB/F01709X/1) and NJH and JEL were supported by graduate studentships from the EPSRC, and JEL after her DPhil by EP/D048559. AMB gratefully acknowledges her current fellowship support from the Royal Society and EPSRC for a Dorothy Hodgkin Fellowship (DH160004). JRH acknowledges support from the ARC (FT120100421) and the Centre for Advanced Imaging, The University of Queensland.Cytochrome P450 (CYP) monooxygenases catalyze the oxidation of chemically inert carbon-hydrogen bonds in diverse endogenous and exogenous organic compounds by atmospheric oxygen. This C–H bond oxy-functionalization activity has huge potential in biotechnological applications. Class I CYPs receive the two electrons required for oxygen activation from NAD(P)H via a ferredoxin reductase and ferredoxin. The interaction of Class I CYPs with their cognate ferredoxin is specific. In order to reconstitute the activity of diverse CYPs, structural characterization of CYP-ferredoxin complexes is necessary, but little structural information is available. Here we report a structural model of such a complex (CYP199A2-HaPux) in frozen solution derived from distance and orientation restraints gathered by the EPR technique of orientation-selective double electron-electron resonance (os-DEER). The long-lived oscillations in the os-DEER spectra were well modeled by a single orientation of the CYP199A2-HaPux complex. The structure is different from the two known Class I CYP-Fdx structures: CYP11A1-Adx and CYP101A1-Pdx. At the protein interface, HaPux residues in the [Fe2S2] cluster-binding loop and the α3 helix, and the C-terminus residue interact with CYP199A2 residues in the proximal loop and the C helix. These residue contacts are consistent with biochemical data on CYP199A2-ferredoxin binding and electron transfer. Electron-tunneling calculations indicate an efficient electron-transfer pathway from the [Fe2S2] cluster to the heme. This new structural model of a CYP-Fdx complex provides the basis for tailoring CYP enzymes for which the cognate ferredoxin is not known, to accept electrons from HaPux and display monooxygenase activity.PostprintPeer reviewe

The effects of ectopic UCP1 expression on gene expression in skeletal muscle [Mus Musculus]

This SuperSeries is composed of the following subset Series: GSE45991: Amino acid deprivation due to overexpression of UCP1 in skeletal muscle: signalling via FGF-21 GSE45992: Transgenic overexpression of UCP1 in skeletal muscle in mice fed a HFD: signalling via FGF-21 Skeletal muscle FGF21 secretion: part of a novel metabolic rescue cycle Susanne Keipert, Mario Ost, Janine Dokas, Evert M. van Schothorst, Mariona Jove, Reinald Pamplona, Manuel Portero-Otin, Jaap Keijer, Susanne Klau