bluuebunny/crossref_metadata_2025_split huggingface dataset:
Oxidative Demethylation of DNA and RNA Mediated by Non‐Heme Iron‐Dependent Dioxygenases
Authors: Lu Lining , Zhu Chenxu , Xia Bo , Yi Chengqi 
Published: June 2014

AbstractDNA/RNA methylation can be generated by methyltransferases and thus plays a critical role in regulating cellular processes; alternatively, nucleic acid methylation can be produced by methylation agents and is cytotoxic/mutagenic if left unrepaired. Oxidative demethylation mediated by non‐heme iron‐dependent dioxygenases is an efficient way to reverse either the cellular roles of regulatory methylation or the cytotoxic/mutagenic effects of methylation damage. In this Focus Review we summarize recent advances in the study of nucleic acid dioxygenases exemplified by the TET and AlkB family proteins, with an emphasis on chemical insights from the recent literature. Comparison of the chemical mechanisms of these dioxygenases revealed that differences in the mechanism also contribute significantly to their distinct biological functions.
Effects of licochalcone A on the bioavailability and pharmacokinetics of nifedipine in rats: possible role of intestinal CYP3A4 and P‐gp inhibition by licochalcone A
Authors: Choi Jin‐Seok , Choi Jun‐Shik , Choi Dong‐Hyun 
Published: June 2014

ABSTRACTThe purpose of this study was to investigate the possible effects of licochalcone A (a herbal medicine) on the pharmacokinetics of nifedipine and its main metabolite, dehydronifedipine, in rats. The pharmacokinetic parameters of nifedipine and/or dehydronifedipine were determined after oral and intravenous administration of nifedipine to rats in the absence (control) and presence of licochalcone A (0.4, 2.0 and 10 mg/kg). The effect of licochalcone A on P‐glycoprotein (P‐gp) and cytochrome P450 (CYP) 3A4 activity was also evaluated. Nifedipine was mainly metabolized by CYP3A4. Licochalcone A inhibited CYP3A4 enzyme activity in a concentration‐dependent manner with a 50% inhibition concentration (IC50) of 5.9 μm. In addition, licochalcone A significantly enhanced the cellular accumulation of rhodamine‐123 in MCF‐7/ADR cells overexpressing P‐gp. The area under the plasma concentration–time curve from time 0 to infinity (AUC) and the peak plasma concentration (Cmax) of oral nifedipine were significantly greater and higher, respectively, with licochalcone A. The metabolite (dehydronifedipine)–parent AUC ratio (MR) in the presence of licochalcone A was significantly smaller compared with the control group. The above data could be due to an inhibition of intestinal CYP3A4 and P‐gp by licochalcone A. The AUCs of intravenous nifedipine were comparable without and with licochalcone A, suggesting that inhibition of hepatic CYP3A4 and P‐gp was almost negligible. Copyright © 2014 John Wiley & Sons, Ltd.
Simultaneous determination of three dipeptides (JBP485, Gly–Sar and JBP923) in the cell lysates by liquid chromatography‐tandem mass spectrometry: application to identify the function of the PEPT1 transfected cell
Authors: Guo Xinjin , Meng Qiang , Liu Qi , Wang Changyuan , Huo Xiaokui , Zhang Zhe , Kaku Taiichi , Liu Kexin 
Published: June 2014

ABSTRACTA simple and rapid liquid chromatography–tandem mass spectrometry (LC‐MS/MS) method for the simultaneous determination of JBP485, Gly–Sar and JBP923 in the cell lysates using methanol as a deproteinization solvent was developed and validated. Detection was performed by turbo ionspray ionization in multiple reaction monitoring mode using the transitions of m/z 147.1 → m/z 90.1 for Gly–Sar, m/z 201.1 → m/z 86.1 for JBP485, m/z 219.1 → m/z 86.1 for JBP923 and m/z 152.0 → m/z 110.0 for paracetamol (internal standard). The analytes were separated on a Hypersil ODS C18 HPLC column using isocratic elution mode with a mobile phase containing 0.1% formic acid in water–methanol (97:3, v/v) at a flow rate of 0.2 mL/min. The calibration curves were demonstrated to be linear over the concentration range of 5.00−5000 nm with coefficient of 0.9968 for Gly–Sar, 0.9975 for JBP485 and 0.9952 for JBP923. The intra‐ and inter‐day precisions were <10.2% for each quality contro; level, and the accuracy was within ±5.6% for each analyte. The matrix effect, the extraction recovery and stabilities of LC‐MS/MS analysis were also investigated. This validated method was successfully applied to the simultaneous determination of JBP485, Gly–Sar and JBP923 in the cell lysates for identification of stably transfected HeLa cells with human PEPT1. Copyright © 2014 John Wiley & Sons, Ltd.
A randomized, phase II study of the anti‐insulin‐like growth factor receptor type 1 (IGF‐1R) monoclonal antibody robatumumab (SCH 717454) in patients with advanced colorectal cancer
Authors: Lin Edward H. , Lenz Heinz‐Josef , Saleh Mansoor N. , Mackenzie Mary J. , Knost James A. , Pathiraja Kumudu , Langdon Ronald B. , Yao Siu‐Long , Lu Brian D. 
Published: June 2014

AbstractOverexpression of insulin‐like growth factor receptor type 1 (IGF‐1R) may promote tumor development and progression in some cancer patients. Our objective was to assess tumor uptake of fluorodeoxyglucose by positron‐emission tomography in patients with chemotherapy‐refractory colorectal cancer treated with an anti‐insulin‐like growth factor receptor type 1 (anti‐IGF‐1R) monoclonal antibody, robatumumab. This was a randomized, open‐label study with two periods (P1 and P2). Patients were randomized 3:1 into treatment arms R/R and C/R that received, respectively, one cycle of 0.3 mg/kg robatumumab or one or more cycles of second‐line chemotherapy in P1, followed in either case by 10 mg/kg robatumumab biweekly in P2. The primary measure of fluorodeoxyglucose uptake was maximum standardized uptake value (SUVmax). The primary endpoint was the proportion of patients in the R/R arm having a mean percent decrease from baseline in SUVmax (DiSUV) greater than 20% 12–14 days postdose in P2. Secondary endpoints included Response Evaluation Criteria in Solid Tumors (RECIST)‐defined tumor response and pharmacodynamic measures of target engagement. Among 41 patients who were evaluable for the primary endpoint, seven (17%, 95% CI 7%–32%) had DiSUV greater than 20%. Fifty robatumumab‐treated patients were evaluable for RECIST‐defined tumor response and six (12%) had stable disease lasting greater than or equal to 7 weeks in P2. Pharmacodynamic endpoints indicated target engagement after dosing with 10 mg/kg robatumumab, but not 0.3 mg/kg. The most frequently reported adverse events were fatigue/asthenia, nausea, anorexia, and gastrointestinal disturbances. In this study, few patients with chemotherapy‐refractory colorectal cancer appeared to benefit from treatment with the IGF‐1R antagonist robatumumab.
Real world comparison of the MGuard Stent versus the bare metal stent for ST Elevation myocardial infarction (The REWARD‐MI study)
Authors: Fernández‐Cisnal Agustín , Cid‐Álvarez B. , Álvarez‐Álvarez B. , Cubero‐Gómez J.M. , Ocaranza‐Sánchez R. , López‐Otero D. , Souto‐Castro P. , Díaz de la Llera L.S. , Trillo‐Nouche R. , González‐Juanatey J.R. 
Published: June 2014

Aim: The MGuard Stent (MGS) was designed to prevent distal embolization of thrombus and has been shown to improve microcirculation in ST‐elevation myocardial infarction (STEMI). However, there are no real world data comparing it with the bare metal stent (BMS). The aim of this study is to determine the efficacy and safety of the MGS in STEMI in the real world compared to the BMS.Methods and Results: In total, 262 patients were included from a single centre, of which 35.9% had an MGS implanted. Two groups of 79 patients were established after propensity score matching, and they were similar in terms of baseline and periprocedural variables. The mean follow‐up was 321 ± 12.94 days. There was no difference in mortality (7.6% in both groups), major adverse cardiac events (20.3% vs. 12.7%, P = 0.198), non‐cardiac mortality, or non‐fatal myocardial infarction (6.3% in both groups). Target lesion revascularization (TLR) was significantly higher in the MGS group (11.4% (9) vs. 1.3% (1) P < 0.01; RR 10.02 [1.23–81.16]).Conclusion: Our study is the first to compare the MGS with the BMS in STEMI in the real world, and it also appears to confirm that although the MGS is a safe device in STEMI that is not associated with increased mortality, it is associated with a higher long‐term TLR rate. © 2014 Wiley Periodicals, Inc.
MitraClip for severe symptomatic mitral regurgitation in patients at high surgical risk
Authors: Philip Femi , Athappan Ganesh , Tuzcu E. Murat , Svensson Lars G. , Kapadia Samir R. 
Published: June 2014

BackgroundThe optimal treatment of patients with severe mitral regurgitation (MR) at high surgical risk (HSR) is unknown. Recently, the EVEREST II (Endovascular Valve Edge‐to‐Edge Repair) High Risk Study suggested MitraClip (MC) was a safe and effective treatment option.MethodsWe performed a search strategy for MC or mitral valve surgery (MVS) in patients at HSR for surgical mortality (logistic EuroSCORE >18 or STS score > 10) using Medline databases, proceedings of international meetings, and the STS database. We identified 21 studies utilizing MC (n = 3,198) and MVS (n = 3,265, >90% from the STS database) from 2003 to 2013. Information about patient characteristics, surgical risk, and 30‐day and 1‐year outcomes were extracted.ResultsPatients who underwent MC or MVS had a mean age of 74 ± 10 years with no differences in surgical risk, NYHA class, or MR grade (P = 0.46). Technical success was achieved in 96% of patients undergoing MC versus 98% in the MVS group (P = 0.45). Patients undergoing MC were treated with one or two MC in 90% (n = 2,878) with only a few requiring repeat MC (0.4%, n = 13) or mitral surgery (0.3%, n = 52) at 30 days. The pooled event rates for mortality was 3.2% (95% CI [2.5–4.2]), stroke was 1.1% (95% CI [0.7–0.2]) at 30 days. At 31 days to 1 year, the pooled event rate for mortality was 13.0% [95% CI (9–18.3)], stroke was 1.6% [95% CI (0.8–3.2)], and repeat MVS was 1.3% [95% CI (0.7–2.6)] with the majority of patients in the mild/moderate MR grade and NYHA class after MC. The 30‐day event rates for mortality and stroke were 16.8% (95% CI [14–19]) and 4.5% (95% CI [3.9–5.3]) after MVS, respectively.ConclusionBased on high risk MC studies and high risk MVS data predominantly from STS database, patients with severe MR who are at HSR can be effectively treated with MC or MVS. MC can be safely implanted in high risk patients with relatively low mortality and stroke risk. © 2014 Wiley Periodicals, Inc.
Two‐year safety and effectiveness of the platinum chromium everolimus‐eluting stent for the treatment of small vessels and longer lesions
Authors: Teirstein Paul S. , Meredith Ian T. , Feldman Robert L. , Rabinowitz A. Charles , Cannon Louis A. , Lee Tommy C. , Dens Joseph , Dubois Christophe L. , Mooney Michael R. , Pompili Vincent J. , Saito Shigeru , Allocco Dominic J. , Dawkins Keith D. , Stone Gregg W. 
Published: June 2014

ObjectivesTo report 1‐ and 2‐year clinical outcomes of patients receiving platinum chromium everolimus‐eluting stents (PtCr‐EES) in the prospective, single‐arm PLATINUM small vessel (SV) and long lesion (LL) studies.BackgroundSmall vessel diameter and long lesion length are independently associated with increased risk of adverse cardiac events after drug‐eluting stent implantation.MethodsThe PLATINUM SV study enrolled 94 patients with coronary artery lesions in vessels ≥2.25 mm to <2.50 mm in diameter and ≤28 mm in length. The PLATINUM LL study enrolled 102 patients with lesions >24 to ≤34 mm long in vessels ≥2.50 to ≤4.25 mm in diameter. The primary endpoint for both studies was target lesion failure (TLF) at 1 year compared to a prespecified performance goal based on outcomes with the TAXUS Express paclitaxel‐eluting stent in small vessels and long lesions.ResultsOne‐year TLF rates with the PtCr‐EES were significantly (P < 0.001) lower than the predetermined performance goals: 2.4% versus 21.1% in the SV cohort and 3.2% versus 19.4% in the LL cohort. Cumulative rates of TLF to 2 years were 4.7% in the SV cohort and 8.8% in the LL cohort. No myocardial infarction or ARC definite/probable stent thromboses occurred in either cohort through 2‐year follow‐up.ConclusionsThe clinical efficacy and safety outcomes observed in these small vessel and long lesion cohorts support the use of the PtCr‐EES in the treatment of small diameter vessels and long lesions. © 2014 Wiley Periodicals, Inc.
Intravenous xenogeneic transplantation of human adipose‐derived stem cells improves left ventricular function and microvascular integrity in swine myocardial infarction model
Authors: Hong Soon Jun , Rogers Pamela I. , Kihlken John , Warfel Jessica , Bull Chris , Deuter‐Reinhard Maja , Feng Dongni , Xie Jie , Kyle Aaron , Merfeld‐Clauss Stephanie , Johnstone Brian H. , Traktuev Dmitry O. , Chen Peng‐Sheng , Lindner Jonathan R. , March Keith L. 
Published: June 2014

ObjectivesThe potential for beneficial effects of adipose‐derived stem cells (ASCs) on myocardial perfusion and left ventricular dysfunction in myocardial ischemia (MI) has not been tested following intravenous delivery.MethodsSurviving pigs following induction of MI were randomly assigned to 1 of 3 different groups: the placebo group (n = 7), the single bolus group (SB) (n = 7, 15 × 107 ASCs), or the divided dose group (DD) (n = 7, 5 × 107 ASCs/day for three consecutive days). Myocardial perfusion defect area and coronary flow reserve (CFR) were compared during the 28‐day follow‐up. Also, serial changes in the absolute number of circulating CD4+T and CD8+T cells were measured.ResultsThe increases in ejection fraction were significantly greater in both the SB and the DD groups compared to the placebo group (5.4 ± 0.9%, 3.7 ± 0.7%, and −0.4 ± 0.6%, respectively), and the decrease in the perfusion defect area was significantly greater in the SB group than the placebo group (−36.3 ± 1.8 and −11.5 ± 2.8). CFR increased to a greater degree in the SB and the DD groups than in the placebo group (0.9 ± 0.2, 0.8 ± 0.1, and 0.2 ± 0.2, respectively). The circulating number of CD8+T cells was significantly greater in the SB and DD groups than the placebo group at day 7 (3,687 ± 317/µL, 3,454 ± 787/µL, and 1,928 ± 457/µL, respectively). The numbers of small vessels were significantly greater in the SB and the DD groups than the placebo group in the peri‐infarct area.ConclusionsBoth intravenous SB and DD delivery of ASCs are effective modalities for the treatment of MI in swine. Intravenous delivery of ASCs, with its immunomodulatory and angiogenic effects, is an attractive noninvasive approach for myocardial rescue. © 2014 Wiley Periodicals, Inc.
Importance of guiding catheter disengagement during measurement of fractional flow reserve in patients with an isolated proximal left anterior descending artery stenosis
Authors: Aminian Adel , Dolatabadi Dariouch , Lefebvre Pascal , Khalil Georges , Zimmerman Robert , Michalakis Georges , Lalmand Jacques 
Published: June 2014

ObjectiveTo determine the impact of ostial guiding catheter disengagement during measurement of fractional flow reserve (FFR) in patients with an isolated proximal left anterior descending artery (LAD) stenosis.MethodsMeasurements of FFR were performed in 21 patients with an isolated intermediate lesion of the proximal LAD. Proximal aortic pressure (Pa), distal post stenotic pressure (Pd), and Pd/Pa were recorded at baseline, after at least 90 sec of intravenous (IV) adenosine infusion with the guiding catheter still engaged in the coronary ostium (Pa1, Pd1, FFReng), and after at least 30 sec of guiding catheter disengagement back to the aorta (Pa2, Pd2, FFRdis).ResultsThe average value of Pd/Pa at baseline was 0.92 ± 0.04. After 110 ± 8 sec of IV adenosine infusion, FFReng was 0.81 ± 0.07, which decreased to 0.77 ± 0.08 (FFRdis) after 38 ± 6 sec of guiding catheter disengagement. The mean ΔFFR (FFReng − FFRdis) was 0.05 ± 0.04. As compared to baseline values, the mean change in FFR values was significantly increased after disengagement of the guiding catheter (Pd/Pabaseline − FFRdis vs. Pd/Pabaseline − FFReng, 0.15 ± 0.05 vs. 0.10 ± 0.04, P < 0.0001). Before guiding catheter disengagement, eight patients (38%) had an FFR value ≤ 0.8. Following disengagement of the guiding catheter, the new FFR values decreased below 0.8 in six additional patients (28%), with subsequent change in treatment strategy.ConclusionsDuring FFR assessment of isolated intermediate proximal LAD lesions, guiding catheter disengagement is associated with a decrease in mean FFR values. In patients with FFR values lying close to the treatment threshold, this can have an impact on treatment strategy. © 2014 Wiley Periodicals, Inc.
Comparison of early clinical outcomes between ABSORB bioresorbable vascular scaffold and everolimus‐eluting stent implantation in a real‐world population
Authors: Costopoulos Charis , Latib Azeem , Naganuma Toru , Miyazaki Tadashi , Sato Katsumasa , Figini Filippo , Sticchi Alessandro , Carlino Mauro , Chieffo Alaide , Montorfano Matteo , Colombo Antonio 
Published: June 2014

ObjectivesTo compare the early clinical outcomes between ABSORB bioresorbable vascular scaffold (BVS) (Abbott Vascular, Santa Clara, CA) and cobalt chromium everolimus‐eluting stents in real‐world patients with mostly complex disease.BackgroundBVS represents the most interesting development in the drug‐eluting stent field over recent years with promising results emerging from clinical trials. Available data however on the use of the ABSORB in real‐world patients is limited.MethodsAll patients (n = 92) treated with BVS and 1296 patients treated with EES were included in this study. Propensity score matching was performed to adjust for differences in baseline clinical characteristics, yielding 92 patient pairs (BVS = 92 patients with 137 lesions and EES = 92 patients with 124 lesions). Clinical outcomes were examined between the 2 groups at 6‐months.ResultsIn both groups, most lesions were classified as either B2 or C (83.9% vs. 77.4%, P = 0.19). Predilatation (97.8% vs. 75.8%, P < 0.01) as well as postdilation (99.3% vs. 77.4%, P < 0.01) was more common in the BVS group. Clinical outcomes at 6‐months were similar between the two groups with respect to both target lesion revascularization (3.3% vs. 5.4%, P = 0.41) and major adverse cardiac events (defined as the composite of target vessel revascularization, follow‐up myocardial infraction and all‐cause death) (3.3% vs. 7.6%, P = 0.19).ConclusionsABSORB BVS for the treatment of complex lesions appears to be associated with good procedural and early clinical outcomes similar to those observed with conventional drug‐eluting stents. Larger studies with long‐term follow‐up are required in order to fully assess the role of BVS in the treatment of such lesions and how this compares with that of conventional stents. © 2014 Wiley Periodicals, Inc.
Easy Access to Ni3N– and Ni–Carbon Nanocomposite Catalysts
Authors: Clavel Guylhaine , Molinari Valerio , Kraupner Alexander , Giordano Cristina 
Published: June 2014

AbstractIn the search for alternative materials to current expensive catalysts, Ni has been addressed as one of the most promising and, on this trail, its corresponding nitride. However, nickel nitride is a thermally unstable compound, and therefore not easy to prepare especially as nanoparticles. In the present work, a sol–gel‐based process (the urea glass route) is applied to prepare well‐defined and homogeneous Ni3N and Ni nanoparticles. In both cases, the prepared crystalline nanoparticles (∼25 nm) are dispersed in a carbon matrix forming interesting Ni3N‐ and Ni‐based composites. These nanocomposites were characterised by means of several techniques, such as XRD, HR‐TEM, EELS, and the reaction mechanism was investigated by TGA and IR and herein discussed. The catalytic activity of Ni3N is investigated for the first time, to the best of our knowledge, for hydrogenation reactions involving H2, and here compared to the one of Ni. Both materials show good catalytic activities but, interestingly, give a different selectivity between different functional groups (namely, nitro, alkene and nitrile groups).
Direct Assembly of 2‐Oxazolidinones by Chemical Fixation of Carbon Dioxide
Authors: Niemi Teemu , Perea‐Buceta Jesus E. , Fernández Israel , Alakurtti Sami , Rantala Erika , Repo Timo 
Published: June 2014

AbstractThe reaction of β‐ and γ‐haloamines with carbon dioxide to give pharmaceutically relevant 2‐oxazolidinones and 1,3‐dioxazin‐2‐ones, was found to proceed efficiently in the presence of a base and in the absence of catalyst. After optimization of reaction conditions, the system was successfully expanded to a variety of haloamines, even at multigram scale. The reaction was further studied in silico by DFT calculations.
Synthesis of Spirocyclic Enones by Rhodium‐Catalyzed Dearomatizing Oxidative Annulation of 2‐Alkenylphenols with Alkynes and Enynes
Authors: Kujawa Szymon , Best Daniel , Burns David J. , Lam Hon Wai 
Published: June 2014

AbstractThe dearomatizing oxidative annulation of 2‐alkenylphenols with alkynes and enynes proceeds with high yields and regioselectivities under RhIII catalysis. These reactions are successful using Cu(OAc)2 or air as the stoichiometric oxidant, and provide spirocyclic enones, the basic ring system of which appears in several natural products. Application of this process to the preparation of a highly functionalized tetracycle is also demonstrated.
Glühlampen und Chemiefasern
Authors: Vogler Herbert 
Published: June 2014

AbstractZu den Erfindungen, die das tägliche Leben maßgebend veränderten, zählt die Glühlampe. Nach häufig zu hörender Meinung ist Thomas Alva Edison diese wichtige Erfindung zu verdanken. Dass die Glühlampe auch einen zweiten Erfinder, nämlich Joseph Wilson Swan hat, bleibt oft unerwähnt. Lediglich in seiner Heimat England gilt Swan als Erfinder, Edison wird dort in diesem Zusammenhang oft übersehen – in Amerika ist es genau umgekehrt, dort ist selbstverständlich Edison der alleinige Erfinder. Wer war es denn nun?
Wie Jugendliche die Chemie sehen
Authors: Pietsch Sebastian , Barke Hans‐Dieter 
Published: June 2014

Abstract“Der Chemielehrer ist vermutlich der einzige, der zu Beginn seines Unterrichts vor eine Klasse treten muss, die sich ihre Meinung über den Wert oder besser Unwert des Faches gemacht hat, welches nun auf sie zukommt. Das bewusste oder unbewusste Gefühl, sozusagen aus der Defensive heraus lehren zu müssen, wirkt sich auf Form und Inhalt seines Unterrichts aus”. Heilbronner und Wyss [1] hatten zu Beginn der 1980er Jahre durch empirische Erhebungen festgestellt, dass die Einstellungen vieler Jugendlicher zur Chemie sehr negativ waren. Wie sieht es heute aus?