bluuebunny/crossref_metadata_2025_split huggingface dataset:
Polarizable Empirical Force Field for Acyclic Polyalcohols Based on the Classical Drude Oscillator
Authors: He Xibing , Lopes Pedro E. M. , MacKerell Alexander D. 
Published: May 2013

ABSTRACTA polarizable empirical force field for acyclic polyalcohols based on the classical Drude oscillator is presented. The model is optimized with an emphasis on the transferability of the developed parameters among molecules of different sizes in this series and on the condensed‐phase properties validated against experimental data. The importance of the explicit treatment of electronic polarizability in empirical force fields is demonstrated in the cases of this series of molecules with vicinal hydroxyl groups that can form cooperative intra‐ and intermolecular hydrogen bonds. Compared to the CHARMM additive force field, improved treatment of the electrostatic interactions avoids overestimation of the gas‐phase dipole moments resulting in significant improvement in the treatment of the conformational energies and leads to the correct balance of intra‐ and intermolecular hydrogen bonding of glycerol as evidenced by calculated heat of vaporization being in excellent agreement with experiment. Computed condensed phase data, including crystal lattice parameters and volumes and densities of aqueous solutions are in better agreement with experimental data as compared to the corresponding additive model. Such improvements are anticipated to significantly improve the treatment of polymers in general, including biological macromolecules. © 2013 Wiley Periodicals, Inc. Biopolymers 99: 724–738, 2013.
Conformational preferences of helix foldamers of γ‐peptides based on 2‐(aminomethyl)cyclohexanecarboxylic acid
Authors: Byun Byung Jin , Kang Young Kee 
Published: May 2013

ABSTRACTThe conformational preferences of helix foldamers having different sizes of the H‐bonded pseudocycles have been studied for di‐ to octa‐γ2,3‐peptides based on 2‐(aminomethyl)cyclohexanecarboxylic acid (γAmc6) with a cyclohexyl constraint on the Cα–Cβ bond using density functional methods. The helical structures of the γAmc6 oligopeptides with homochiral configurations are known to be much stable than those with heterochiral configurations in the gas phase and in solution (chloroform and water). In particular, it is found that the (P/M)−2.514‐helices are most preferred in the gas phase and in chloroform, whereas the (P/M)−2.312‐helices become most populated in water due to the larger helix dipole moments. As the peptide sequence becomes longer, the helix propensities of 14‐ and 12‐helices are found to increase both in the gas phase and in solution. The γAmc6 peptides longer than octapeptide are expected to exist as a mixture of 12‐ and 14‐helices with the similar populations in water. The mean backbone torsion angles and helical parameters of the 14‐helix foldamers of γAmc6 oligopeptides are quite similar to those of 2‐aminocyclohexylacetic acid oligopeptides and γ2,3,4‐aminobutyric acid tetrapeptide in the solid state, despite the different substituents on the backbone. © 2013 Wiley Periodicals, Inc. Biopolymers 101: 87–95, 2014.
Circular dichroism and electron microscopy studies in vitro of 33‐mer gliadin peptide revealed secondary structure transition and supramolecular organization
Authors: Herrera María G. , Zamarreño Fernando , Costabel Marcelo , Ritacco Hernan , Hütten Andreas , Sewald Norbert , Dodero Verónica I. 
Published: May 2013

ABSTRACTGliadin, a protein present in wheat, rye, and barley, undergoes incomplete enzymatic degradation during digestion, producing an immunogenic 33‐mer peptide, LQLQPF(PQPQLPY)3PQPQPF. The special features of 33‐mer that provoke a break in its tolerance leading to gliadin sensitivity and celiac disease remains elusive. Herein, it is reported that 33‐mer gliadin peptide was not only able to fold into polyproline II secondary structure but also depending on concentration resulted in conformational transition and self‐assembly under aqueous condition, pH 7.0. A 33‐mer dimer is presented as one initial possible step in the self‐assembling process obtained by partial electrostatics charge distribution calculation and molecular dynamics. In addition, electron microscopy experiments revealed supramolecular organization of 33‐mer into colloidal nanospheres. In the presence of 1 mM sodium citrate, 1 mM sodium borate, 1 mM sodium phosphate buffer, 15 mM NaCl, the nanospheres were stabilized, whereas in water, a linear organization and formation of fibrils were observed. It is hypothesized that the self‐assembling process could be the result of the combination of hydrophobic effect, intramolecular hydrogen bonding, and electrostatic complementarity due to 33‐mer's high content of proline and glutamine amino acids and its calculated nonionic amphiphilic character. Although, performed in vitro, these experiments have revealed new features of the 33‐mer gliadin peptide that could represent an important and unprecedented event in the early stage of 33‐mer interaction with the gut mucosa prior to onset of inflammation. Moreover, these findings may open new perspectives for the understanding and treatment of gliadin intolerance disorders. © 2013 Wiley Periodicals, Inc. Biopolymers 101: 96–106, 2014.
Amphiphilic Cytosolic Glycans from Mycobacteria: Occurrence, Lipid‐Binding Properties, Biosynthesis, and Synthesis
Authors: Xia Li , Lowary Todd L. 
Published: May 2013

ABSTRACTPolymethylated polysaccharides (PMPSs), glycans composed of 10–20 carbohydrate residues the majority of which carry a single methyl group, are produced by some mycobacterial species. O‐Methylation thus occurs on 20–30% of all the hydroxyl groups within the molecule, rendering them amphiphilic. A property of PMPSs is their ability to form high‐affinity complexes with fatty acids and their derivatives, suggesting a role in mycobacterial fatty acid biosynthesis. However, direct evidence for their in vivo function is still lacking. Over the past several decades the lipid‐binding properties, biosynthesis, and chemical synthesis of PMPSs have been explored and this review will provide an overview of progress made in these areas. © 2013 Wiley Periodicals, Inc. Biopolymers 99: 697–712, 2013.
High expression of ZNF703 independent of amplification indicates worse prognosis in patients with luminal B breast cancer
Authors: Reynisdottir Inga , Arason Adalgeir , Einarsdottir Berglind O. , Gunnarsson Haukur , Staaf Johan , Vallon‐Christersson Johan , Jonsson Goran , Ringnér Markus , Agnarsson Bjarni A. , Olafsdottir Kristrun , Fagerholm Rainer , Einarsdottir Thorbjorg , Johannesdottir Gudrun , Johannsson Oskar Thor , Nevanlinna Heli , Borg Ake , Barkardottir Rosa Bjork 
Published: May 2013

AbstractAmplification of 8p12‐p11 is relatively common in breast cancer and several genes within the region have been suggested to affect breast tumor progression. The aim of the study was to map the amplified 8p12‐p11 region in a large set of breast tumors in an effort to identify the genetic driver and to explore its impact on tumor progression and prognosis. Copy number alterations (CNAs) were mapped in 359 tumors, and gene expression data from 577 tumors (359 tumors included) were correlated with CNA, clinical–pathological factors, and protein expression (39 tumors). 8p12‐p11 was amplified in 11.4% of tumors. The smallest region of amplification harbored one full‐length gene, ZNF703. ZNF703 mRNA expression was significantly higher in estrogen receptor (ER)‐positive than ER‐negative tumors (P = 2 × 10−16), a reflection of high expression in luminal tumors. Forty‐eight percent of tumors with ZNF703 amplification were luminal B tumors in which the best correlation between DNA copy number and mRNA was seen (P = 1.2 × 10−7) as well as correlation between mRNA and protein expression (P = 0.02). High ZNF703 mRNA correlated with poor survival in patients with ER‐positive luminal B tumors (log rank P = 0.04). Furthermore, high ZNF703 mRNA expression correlated with poor outcome in patients with ZNF703 copy number neutral, ER‐positive, luminal B tumors (log rank P = 0.004). The results support ZNF703 as the driver gene of the 8p12 amplification and suggest that independent of amplification, high expression of the gene affects prognosis in luminal B tumors.
Vascular, downstream, and pharmacokinetic responses to treatment with a low dose drug‐coated balloon in a swine femoral artery model
Authors: Yazdani Saami K. , Pacheco Erica , Nakano Masataka , Otsuka Fumiyuki , Naisbitt Scott , Kolodgie Frank D. , Ladich Elena , Rousselle Serge , Virmani Renu 
Published: May 2013

ObjectivesThis study was designed to evaluate the safety of a novel drug‐coated balloon (DCB) with 2 µg/mm2 paclitaxel and a carrier comprised of polysorbate and sorbitol in a swine femoral artery model.BackgroundDCB have emerged as a therapeutic alternative in the treatment of peripheral vascular disease.MethodsThe femoral arteries of 45 swine were treated with low pressure balloon inflation either 1× clinical dose (single inflation, 2 µg/mm2 paclitaxel) or 4× dose (2 DCBs, each with 4 µg/mm2 paclitaxel) or control (uncoated) balloons. The treated arteries, downstream vascular beds, and organs were assessed histologically at 28, 90, and 180‐days. Twenty‐four swine were treated with 1× dose for pharmacokinetic analysis through 30 days.ResultsArterial tissue paclitaxel concentration was 58.8 ± 54.2 ng/mg at 1‐hr and 0.3 ± 0.4 ng/mg at 30 days, whereas plasma paclitaxel could no longer be detected after 1 day. The treated arteries displayed minimal endothelial loss, fibrin deposition, and inflammation with long‐term dose‐dependent drug effect (medial smooth muscle cell loss) peaking at 90 days for both 1× (1.1 ± 1.4 vs. 0.0 ± 0.0, P = 0.008) and 4× dose (2.0 ± 1.5 vs. 0.0 ± 0.0, P < 0.001). In parallel, healing of the treated arteries was evident by significantly greater medial proteoglycan and collagen deposition at 180 days. No evidence of ischemia from downstream emboli or systemic toxicity was observed even for 4× DCB groups.ConclusionsThe findings indicate desired pharmacologic levels with biologic effects at early and healing at late time points in the treated arteries, without evidence of significant downstream emboli or systemic toxicity, consistent with safety of the Lutonix® DCB. © 2013 Wiley Periodicals, Inc.
Clinical effects of routine postdilatation of drug‐eluting stents
Authors: Pasceri Vincenzo , Pelliccia Francesco , Pristipino Christian , Roncella Adriana , Irini Diego , Varveri Antonio , Bisciglia Andrea , Speciale Giulio 
Published: May 2013

ObjectivesTo assess the clinical effects of postdilatation of drug‐eluting stents (DES).BackgroundSubotpimal stent expansion occurs after DES deployment. Postidlatation may improve DES expansion, but it is unclear whether postdilatation may also improve clinical outcomes.MethodsSince July 2009, we adopted a strategy of routine postdilatation with noncompliant balloons of all DES, while previously postdilatation was performed only for suboptimal results. The first 279 consecutive patients (age 62 ± 9 years, 231 men) who underwent routine postilatation were compared with 262 patients (age 61 ± 9 years, 220 men) who received DES in the previous 6 months (standard treatment).ResultsThe two groups were similar for age, sex, clinical presentation, and main risk factors, including incidence of diabetes. Routine postdilatation resulted in an improved minimal lumen diameter at the end of the procedure (2.60 ± 0.34 vs. 2.51 ± 0.37 mm, P = 0.003). At 12‐month follow‐up incidence of MACE (including periprocedural myocardial infarction) was 19.5% in the standard treatment group and 12.5% in routine postdilatation group (P = 0.04), with a significant difference in target vessel revascularization (10.7% vs. 5.4%, P = 0.03), while incidence of myocardial infarction was not significantly different between the two groups (10.7% vs. 9.3%, P = 0.70). Stent thrombosis (definite or probable) occurred in 3 patients in standard treatment group, while no case of stent thrombosis occurred among patients treated with routine postdilatation (1.1% vs. 0%, P = 0.11).ConclusionsOur results suggest that a strategy of routine postdilatation with non compliant balloons may improve clinical outcomes of DES. © 2013 Wiley Periodicals, Inc.
The myocardium supplied by a chronic total occlusion is a persistently ischemic zone
Authors: Sachdeva Rajesh , Agrawal Mayank , Flynn Shawn E. , Werner Gerald S. , Uretsky Barry F. 
Published: May 2013

Well‐developed collaterals to a myocardial segment supplied by a chronic total occlusion (CTO) and/or left ventricular dysfunction in the CTO regions in patients with chronic stable angina suggest that severe ischemia is unlikely to be present. We evaluated the presence and severity of ischemia using fractional flow reserve (FFR) of the myocardium supplied by a CTO in patients and compared the results with a non‐CTO control group.MethodsPatients undergoing FFR and successful percutaneous coronary intervention (PCI) of a CTO were evaluated and compared to a matched non‐CTO control group.ResultsOne hundred patients were included (50 CTO/50 controls). CTO lesions were longer (31.6 ± 18.9 vs 20.2 ± 14.9 mm, P = 0.004) and required more stents (2.2 ± 0.8 vs 1.2 ± 0.5, P = 0.001). FFR was lower (P = 0.0003) with CTO (0.45 ± 0.15) than controls (0.58 ± 0.17) prior to intervention but similar after PCI (CTO 0.91 ± 0.05 vs non‐CTO 0.90 ± 0.08). All CTO patients demonstrated an ischemic FFR, even with severe regional dysfunction or well‐developed collaterals. Resting ischemia was present in 78% (39/50) of CTO patients as evidenced by a resting Pd/Pa of <0.80.ConclusionIn symptomatic patients, a CTO, even with regional left ventricular impairment and/or excellent collateral development, reveals an ischemic zone. This ischemic zone can be normalized by PCI with outcomes appearing to be comparable to non‐CTO patients. © 2013 Wiley Periodicals, Inc.
Procedural success and long‐term outcomes of aspiration thrombectomy for the treatment of stent thrombosis
Authors: Waldo Stephen W. , Armstrong Ehrin J. , Yeo Khung‐Keong , Patel Mitul , Reeves Ryan , MacGregor John S. , Low Reginald I. , Mahmud Ehtisham , Rogers Jason H. , Shunk Kendrick 
Published: May 2013

BackgroundStent thrombosis (ST) is associated with a significant burden of coronary thrombus and potential microvascular obstruction. Aspiration thrombectomy may decrease the extent of microvascular obstruction in patients with acute myocardial infarction but its role in the treatment of ST is uncertain. The present study sought to evaluate the association between aspiration thrombectomy, procedural success and long‐term outcomes among patients presenting with ST.MethodsIn a multicenter cohort of patients with definite ST, procedural success, long‐term mortality, and major adverse cardiovascular events (death, stroke, re‐infarction, revascularization) were ascertained. Propensity weighting was used to determine the association between aspiration thrombectomy and long‐term outcomes.ResultsA total of 205 patients with ST were identified. Among these, 115 (56%) patients underwent adjunctive aspiration thrombectomy during percutaneous coronary intervention. Patients undergoing aspiration thrombectomy were more likely to present with ST‐elevation myocardial infarction (75% vs. 52%, P < 0.003) and require hemodynamic support (19% vs. 10%, P = 0.07). Aspiration thrombectomy was associated with improved procedural outcomes including postprocedural TIMI 3 flow, resulting in higher angiographic and procedural success (each 96% vs. 83%, P < 0.001). Despite improved angiographic outcomes, the use of aspiration thrombectomy was not associated with a difference in long‐term mortality (adjusted HR 0.99, 95% CI 0.44–2.24) or major adverse cardiovascular events (adjusted HR 1.06, 95% CI 0.45–2.48).ConclusionsAspiration thrombectomy is associated with improved coronary flow and procedural success but is not associated with improved long‐term outcomes among patients undergoing percutaneous intervention for definite ST.Clinical Trial Registration: NCT00931502 (http://www.clinicaltrials.gov/ct2/show/NCT00931502) © 2013 Wiley Periodicals, Inc.
The Presence of angiographic collaterals in Non‐ST elevation myocardial infarction is a predictor of long‐term clinical outcomes
Authors: Kloepfer Angela M. , Lipson Lewis C. , Keeley Ellen C. 
Published: May 2013

ObjectivesTo determine whether the presence of angiographic coronary collaterals is a predictor of long‐term clinical outcomes in patients with non‐ST elevation myocardial infarction (NSTEMI).BackgroundThe presence of coronary collaterals on angiography provides prognostic information in patients with STEMI, but it is unknown whether they provide prognostic information in patients with NSTEMI.MethodsThis was a prospective cohort study of 931 consecutive patients undergoing coronary angiography of which 269 (29%) had a NSTEMI. Baseline characteristics, angiographic details, and long‐term clinical outcomes including death, recurrent MI, coronary artery bypass graft surgery (CABG), percutaneous coronary intervention (PCI), stroke, and congestive heart failure (CHF) were collected. Each clinical outcome as well as the combined endpoint of death, recurrent MI, CABG, PCI stroke and CHF was compared in subjects with and without collaterals.ResultsAt one year, individuals with collaterals had significantly increased rates of the combined endpoint compared with those without (25% vs. 16%, P = 0.0001). On multivariate analysis, the presence of collaterals was a strong predictor of the combined endpoint of death, recurrent MI, CABG, PCI, stroke and CHF (HR 1.95, CI 95% 1.08−3.52; P = 0.027). Similarly, in the subset of 115 patients (43%) in whom the culprit artery was identified, the presence of collaterals was a strong negative predictor (HR 3.71, CI 1.31−10.57, P = 0.014), driven by a 13‐fold increase in subsequent CABG.ConclusionsIn patients with NSTEMI the presence of angiographic coronary collaterals is a predictor of long‐term clinical outcomes primarily driven by increased rates of surgical revascularization. © 2013 Wiley Periodicals, Inc.
Drug‐eluting balloons for De Novo coronary artery disease
Authors: Zhang Tuo , Sun Shiqun , Shen Linghong , He Ben 
Published: May 2013

ObjectivesTo evaluate the effectiveness of drug‐eluting balloons (DEBs) in the treatment of de novo coronary artery disease by performing a meta‐analysis of randomized controlled trials (RCTs).BackgroundsCurrent evidence regarding the success of DEBs is insufficient to formulate formal recommendations.MethodsSeven RCTs were ultimately included. The primary angiographic endpoint was in‐segment diameter stenosis, compared by measuring weighted mean difference (WMD). The primary clinical endpoint was incidence of major adverse cardiovascular events (MACEs) during a 1‐year follow‐up, compared by measuring pooled risk ratio (RR).ResultsFor de novo native coronary lesions intervention, DEB plus bare metal stent (BMS) was not superior to BMS alone in both primary angiographic and clinical endpoints (in‐segment diameter stenosis: WMD, −2.59% [95% confidence interval (CI): −9.13% to 3.94%]; MACEs: RR, 0.83 [95%CI: 0.48–1.46]), and DEB with/without BMS was associated with worse outcomes when compared with DES alone (in‐segment diameter stenosis: WMD, 10.64% [95%CI: 2.41–18.87%]; MACEs: RR, 1.54 [95%CI: 0.91–2.61]). Subgroup analysis showed that DEB plus BMS significantly increased the risk of MACEs for simple de novo coronary lesions intervention when compared with DES alone (RR, 1.87 [95%CI: 1.33–2.63]).ConclusionsCurrent data does not support the use of DEBs for de novo coronary lesions, especially for simple coronary lesions. © 2013 Wiley Periodicals, Inc.
Carotid artery stenting according to the “tailored CAS” algorithm performed in the very elderly patients: The thirty day outcome
Authors: Dzierwa Karolina , Pieniazek Piotr , Tekieli Lukasz , Musialek Piotr , Przewlocki Tadeusz , Kablak‐Ziembicka Anna , Kosobucka‐Peszat Renata , Machnik Roman , Trystula Mariusz , Podolec Piotr 
Published: May 2013

ObjectivesTo assess safety and efficacy of carotid artery stenting (CAS) according to “tailored—CAS” algorithm in the elderly (≥75 years) in relation to younger patients.BackgroundAlthough CAS has grown as an alternative to carotid endarterectomy the data on safety of CAS in the very elderly are inconsistent.Material and Methods1,139 patients with significant carotid stenosis underwent 1,252 CAS procedures in one high‐volume center between years 2001–2011. CAS procedures were performed with lesion and patient dependent selection of neuroprotection type (“tailored‐CAS”). There were 193 subjects ≥75‐years‐old (17%) and 946 <75‐years‐old. No major differences in atherosclerosis risk factors and comorbidities between groups were noted. In both groups the majority of patients were male (70.4% vs. 68.6%, P = NS) and half of the patients were symptomatic (50.2% vs. 55.2%, P = NS). Bilateral carotid stenosis was present in 25% of patients from CAS ≥75 group and 22% from CAS< 75 group, P = NS. Proximal neuroprotection devices use for high risk or symptomatic lesions accounted for 31% in CAS≥ 75 group and 32% in CAS<75 group, P = NS.ResultsIn symptomatic patients aged ≥75 years 30‐day stroke and death rate was 7% versus 1.9% in symptomatic patients aged <75; P = 0.01 and vs. 1.8% in asymptomatic elderly, P = 0.09. No myocardial infarcts were noted.ConclusionsSymptomatic elderly is a group of highest CAS risk and the use of “tailored CAS” algorithm does not equalize CAS risk in this patients' group. “Tailored CAS” remains a safe procedure for asymptomatic elderly as well as symptomatic and asymptomatic young patients. © 2013 Wiley Periodicals, Inc.
Experimental and Computational Studies on the Formation of Three para‐Benzyne Analogues in the Gas Phase
Authors: Kirkpatrick Lindsey M. , Vinueza Nelson R. , Jankiewicz Bartłomiej J. , Gallardo Vanessa A. , Archibold Enada F. , Nash John J. , Kenttämaa Hilkka I. 
Published: May 2013

AbstractExperimental and computational studies on the formation of three gaseous, positively‐charged para‐benzyne analogues in a Fourier transform ion cyclotron resonance (FT‐ICR) mass spectrometer are reported. The structures of the cations were examined by isolating them and allowing them to react with various neutral reagents whose reactions with aromatic carbon‐centered σ‐type mono‐ and biradicals are well understood. Cleavage of two iodine–carbon bonds in N‐deuterated 1,4‐diiodoisoquinolinium cation by collision‐activated dissociation (CAD) produced a long‐lived cation that showed nonradical reactivity, which was unexpected for a para‐benzyne. However, the reactivity closely resembles that of an isomeric enediyne, N‐deuterated 2‐ethynylbenzonitrilium cation. A theoretical study on possible rearrangement reactions occurring during CAD revealed that the cation formed upon the first iodine atom loss undergoes ring‐opening before the second iodine atom loss to form an enediyne instead of a para‐benzyne. Similar results were obtained for the 5,8‐didehydroisoquinolinium cation and the 2,5‐didehydropyridinium cation. The findings for the 5,8‐didehydroisoquinolinium cation are in contradiction with an earlier report on this cation. The cation described in the literature was regenerated by using the literature method and demonstrated to be the isomeric 5,7‐didehydro‐isoquinolinium cation and not the expected 5,8‐isomer.