Measurement of the cross-section and forward-backward charge asymmetry for the b and c-quark in e+e- annihilation with inclusive muons at sqrt(s) = 58 GeV

We have studied inclusive muon events using all the data collected by the TOPAZ detector at sqrt(s)=58 GeV with an integrated luminosity of 273pb-1. From 1328 inclusive muon events, we measured the ratio R_qq of the cross section for qq-bar production to the total hadronic cross section and forward-backward asymmetry A^q_FB for b and c quarks. The obtained results are R_bb = 0.13+-0.02(stat)+-0.01(syst), R_cc = 0.36+-0.05(stat)+-0.05(syst), A^b_FB = -0.20+-0.16(stat)+-0.01(syst) and A^c_FB = -0.17+-0.14(stat)+-0.02(syst), in fair agreement with a prediction of the standard model.Comment: To be published in EPJ C. 24 pages, 12 figure

Scope and Mechanistic Study of the Coupling Reaction of α,β-Unsaturated Carbonyl Compounds with Alkenes: Uncovering Electronic Effects on Alkene Insertion vs Oxidative Coupling Pathways

The cationic ruthenium-hydride complex [(C6H6)(PCy3)(CO)RuH]+BF4– (1) was found to be a highly effective catalyst for the intermolecular conjugate addition of simple alkenes to α,β-unsaturated carbonyl compounds to give (Z)-selective tetrasubstituted olefin products. The analogous coupling reaction of cinnamides with electron-deficient olefins led to the oxidative coupling of two olefinic C–H bonds in forming (E)-selective diene products. The intramolecular version of the coupling reaction efficiently produced indene and bicyclic fulvene derivatives. The empirical rate law for the coupling reaction of ethyl cinnamate with propene was determined as follows: rate = k[1]1[propene]0[cinnamate]−1. A negligible deuterium kinetic isotope effect (kH/kD = 1.1 ± 0.1) was measured from both (E)-C6H5CH═C(CH3)CONHCH3 and (E)-C6H5CD═C(CH3)CONHCH3 with styrene. In contrast, a significant normal isotope effect (kH/kD = 1.7 ± 0.1) was observed from the reaction of (E)-C6H5CH═C(CH3)CONHCH3 with styrene and styrene-d8. A pronounced carbon isotope effect was measured from the coupling reaction of (E)-C6H5CH═CHCO2Et with propene (13C(recovered)/13C(virgin) at Cβ = 1.019(6)), while a negligible carbon isotope effect (13C(recovered)/13C(virgin) at Cβ = 0.999(4)) was obtained from the reaction of (E)-C6H5CH═C(CH3)CONHCH3 with styrene. Hammett plots from the correlation of para-substituted p-X-C6H4CH═CHCO2Et (X = OCH3, CH3, H, F, Cl, CO2Me, CF3) with propene and from the treatment of (E)-C6H5CH═CHCO2Et with a series of para-substituted styrenes p-Y-C6H4CH═CH2 (Y = OCH3, CH3, H, F, Cl, CF3) gave the positive slopes for both cases (ρ = +1.1 ± 0.1 and +1.5 ± 0.1, respectively). Eyring analysis of the coupling reaction led to the thermodynamic parameters, ΔH⧧ = 20 ± 2 kcal mol–1 and ΔS⧧ = −42 ± 5 eu. Two separate mechanistic pathways for the coupling reaction have been proposed on the basis of these kinetic and spectroscopic studies

TP53 mutations, amplification of P63 and expression of cell cycle proteins in squamous cell carcinoma of the oesophagus from a low incidence area in Western Europe

In Europe, high incidence rates of oesophageal squamous cell carcinoma (SCCE) are observed in western France (Normandy and Brittany) and in north-eastern Italy. Analysis of TP53 mutations in tumours from these regions has shown a high prevalence of mutations at A:T basepairs that may result from DNA damage caused by specific mutagens. However, the spectrum of TP53 mutations in regions of low incidence is unknown. We report here TP53 mutation analysis in 33 SCCE collected in Lyon, an area of low incidence. These tumours were also examined for MDM2 and P63 amplification, and for expression of p16INK4a/CDKN2a, cyclin E, p27Kipland Cox2. TP53 mutations were detected in 36% of the cases (12/33). In contrast with regions of high incidence, the mutation spectrum did not show a high prevalence of mutations at A:T base pairs. P63 was amplified in 5/32 cases tested (15.5%). No amplification of MDM2 was found. Expression studies revealed frequent loss of p16INK4a/CDKN2a(46%) and p27Kipl(25%) expression, and frequent overexpression of Cyclin E (70%) and Cox2 (42%). Overall, these results indicate that in Europe, SCCE from areas of high and low incidence present a similar pattern of molecular alterations but differ by the type of TP53 mutations. © 2001 Cancer Research Campaign http://www.bjcancer.co

Induction of transforming growth factor-beta 1 by androgen is mediated by reactive oxygen species in hair follicle dermal papilla cells

The progression of androgenetic alopecia is closely related toandrogen-inducible transforming growth factor (TGF)-β1 secretionby hair follicle dermal papilla cells (DPCs) in bald scalp.Physiological levels of androgen exposure were reported toincrease reactive oxygen species (ROS) generation. In thisstudy, rat vibrissae dermal papilla cells (DP-6) transfected withandrogen receptor showed increased ROS production followingandrogen treatment. We confirmed that TGF-β1 secretion isincreased by androgen treatment in DP-6, whereas androgeninducibleTGF-β1 was significantly suppressed by the ROSscavenger,N-acetyl cysteine. Therefore, we suggest that inductionof TGF-β1 by androgen is mediated by ROS in hair follicleDPCs.This study was supported by a grant from the Korea Healthcare Technology R&D Project, Ministry of Health & Welfare, Republic of Korea (Grant No. A103017) and partially by a research agreement with AmorePacific Corporation, Republic of Korea.OAIID:oai:osos.snu.ac.kr:snu2013-01/102/0000045457/8SEQ:8PERF_CD:SNU2013-01EVAL_ITEM_CD:102USER_ID:0000045457ADJUST_YN:NEMP_ID:A079130DEPT_CD:801CITE_RATE:1.634FILENAME:(460-464)bmb 12-228.pdfDEPT_NM:의학과EMAIL:[email protected]_YN:YCONFIRM:

Hippocampal Deletion of BDNF Gene Attenuates Gamma Oscillations in Area CA1 by Up-Regulating 5-HT3 Receptor

Background: Pyramidal neurons in the hippocampal area CA3 express high levels of BDNF, but how this BDNF contributes to oscillatory properties of hippocampus is unknown. Methodology/Principal Findings: Here we examined carbachol-induced gamma oscillations in hippocampal slices lacking BDNF gene in the area CA3. The power of oscillations was reduced in the hippocampal area CA1, which coincided with increases in the expression and activity of 5-HT3 receptor. Pharmacological block of this receptor partially restored power of gamma oscillations in slices from KO mice, but had no effect in slices from WT mice. Conclusion/Significance: These data suggest that BDNF facilitates gamma oscillations in the hippocampus by attenuating signaling through 5-HT3 receptor. Thus, BDNF modulates hippocampal oscillations through serotonergic system