Microbiota, Oral Microbiome, and Pancreatic Cancer

Only 30% of patients diagnosed with pancreatic cancer survive one year post-diagnosis. Progress in understanding the causes of pancreatic cancer has been made, including solidifying the associations with obesity and diabetes, and a proportion of cases should be preventable through lifestyle modifications. Unfortunately, identifying reliable biomarkers of early pancreatic cancer has been extremely challenging, and no effective screening modality is currently available for this devastating form of cancer. Recent data suggest the microbiota may play a role in the disease process, but many questions remain. Future studies focusing on the human microbiome, both etiologically and as a marker of disease susceptibility, should shed light on how to better tackle prevention, early detection, and treatment of this highly fatal disease

Implications of WMAP observations on Li abundance and stellar evolution models

The WMAP determination of the baryon-to-photon ratio implies, through Big Bang nucleosynthesis, a cosmological Li abundance larger, by a factor of 2 to 3, than the Li abundance plateau observed in the oldest Pop II stars. It is however inescapable that there be a reduction by a factor of at least 1.6 to 2.0 of the surface Li abundance during the evolution of Pop II field stars with [Fe/H] < -1.5. That the observed Li be lower than cosmologically produced Li is expected from stellar evolution models. Since at turnoff most of the Li abundance reduction is caused by gravitational settling, the presence of Lithium 6 in some turnoff stars is also understood. Given that the WMAP implications for Li cosmological abundance and the Li Spite plateau can be naturally explained by gravitational settling in the presence of weak turbulence, there appears little need for exotic physics as suggested by some authors. Instead, there is a need for a better understanding of turbulent transport in the radiative zones of stars. This requires simulations from first principles. Rather strict upper limits to turbulent transport are determined for the Sun and Pop II stars.Comment: The Astrophysical Journal, in pres

Insights into Naxi and Pumi at the end of the 19th century: evidence on sound changes from the word lists by Charles-Eudes Bonin

International audienceThe word lists published in 1903 by C.-E. Bonin for several languages of East Asia are highly rudimentary; the transcription is based on French spelling conventions. These lists nonetheless provide hints about the pronunciation of these languages at the end of the 19th century. We examine two of Bonin's lists in light of more recent and more systematic descriptions of the same languages, looking for evidence about phonetic evolutions. The Naxi word list offers hints about the pronunciation of vowels /i/, /y/ and /o/ and the degree of palatalization of velars before high front vowels. The list for Pumi shows that the initial cluster /st-/ was still present at the time in the dialect recorded.Les vocabulaires de cinq langues d'Asie orientale publiés en 1903 par Charles-Eudes Bonin sont transcrits de façon rudimentaire, selon les conventions orthographiques du français. Ils fournissent néanmoins des indices concernant la prononciation de ces langues peu avant 1900. Nous examinons deux des listes de Bonin à la lumière de données plus récentes et plus systématiques, afin de déceler d'éventuelles indications sur des changements phonétiques. La liste de mots naxi fournit des indices concernant le degré de palatalisation des vélaires devant les voyelles fermées d'avant et la prononciation des voyelles /i/, /y/ et /o/. La liste de mots pumi révèle que le groupe /st-/ existait encore à l'époque dans le dialecte étudié

Metabolic Activity and mRNA Levels of Human Cardiac CYP450s Involved in Drug Metabolism

Tissue-specific expression of CYP450s can regulate the intracellular concentration of drugs and explain inter-subject variability in drug action. The overall objective of our study was to determine in a large cohort of samples, mRNA levels and CYP450 activity expressed in the human heart.CYP450 mRNA levels were determined by RTPCR in left ventricular samples (n = 68) of explanted hearts from patients with end-stage heart failure. Samples were obtained from ischemic and non-ischemic hearts. In some instances (n = 7), samples were available from both the left and right ventricles. A technique for the preparation of microsomes from human heart tissue was developed and CYP450-dependent activity was determined using verapamil enantiomers as probe-drug substrates.Our results show that CYP2J2 mRNA was the most abundant isoform in all human heart left ventricular samples tested. Other CYP450 mRNAs of importance were CYP4A11, CYP2E1, CYP1A1 and CYP2C8 mRNAs while CYP2B6 and CYP2C9 mRNAs were present at low levels in only some of the hearts analyzed. CYP450 mRNAs did not differ between ischemic and non-ischemic hearts and appeared to be present at similar levels in the left and right ventricles. Incubation of verapamil with heart microsomes led to the formation of nine CYP450-dependent metabolites: a major finding was the observation that stereoselectivity was reversed compared to human liver microsomes, in which the R-enantiomer is metabolized to a greater extent.This study determined cardiac mRNA levels of various CYP450 isozymes involved in drug metabolism and demonstrated the prevalent expression of CYP2J2 mRNA. It revealed that cardiomyocytes can efficiently metabolize drugs and that cardiac CYP450s are highly relevant with regard to clearance of drugs in the heart. Our results support the claim that drug metabolism in the vicinity of a drug effector site can modulate drug effects

Décrochage, raccrochage et rétention scolaires selon les Jeunes franco-ontariens

L’article présente les résultats d’une recherche menée dans les écoles de langue française de l’Ontario sur le décrochage de l’école secondaire, en soulignant le phénomène du « décrochage culturel », selon lequel les jeunes quittent l’école de langue française pour poursuivre leurs études en anglais. À partir du point de vue de jeunes qui vivent, qui ont vécu ou qui sont à risque de vivre le décrochage, les auteurs illus­trent la complexité de cette question dans une perspective multi­factorielle et multidimensionnelle.The paper presents the results of a province-wide study of drop-outs in Ontarian French-language secondary schools. It highlights the phenomena of cultural drop-outs, relating to students who decide to pursue their studies in English-language schools instead of continuing in French. The authors illustrate the complexity of the issue through the multidi­men­sional perspect­ives of youths who have dropped out of school or are at risk of doing so