bluuebunny/crossref_metadata_2025_split huggingface dataset:
Virus filtration of high‐concentration monoclonal antibody solutions
Authors: Marques Bruno F. , Roush David J. , Göklen Kent E. 
Published: April 2009

AbstractThe ability to process high‐concentration monoclonal antibody solutions (> 10 g/L) through small‐pore membranes typically used for virus removal can improve current antibody purification processes by eliminating the need for feed stream dilution, and by reducing filter area, cycle‐time, and costs. In this work, we present the screening of virus filters of varying configurations and materials of construction using MAb solutions with a concentration range of 4–20 g/L. For our MAbs of interest—two different humanized IgG1s—flux decay was not observed up to a filter loading of 200 L/m2 with a regenerated cellulose hollow fiber virus removal filter. In contrast, PVDF and PES flat sheet disc membranes were plugged by solutions of these same MAbs with concentrations >4 g/L well before 50 L/m2. These results were obtained with purified feed streams containing <2% aggregates, as measured by size exclusion chromatography, where the majority of the aggregate likely was composed of dimers. Differences in filtration flux performance between the two MAbs under similar operating conditions indicate the sensitivity of the system to small differences in protein structure, presumably due to the impact of these differences on nonspecific interactions between the protein and the membrane; these differences cannot be anticipated based on protein pI alone. Virus clearance data with two model viruses (XMuLV and MMV) confirm the ability of hollow fiber membranes with 19 ± 2 nm pore size to achieve at least 3–4 LRV, independent of MAb concentration, over the range examined. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009
Teaching chemical reaction engineering using EMSO simulator
Authors: Rodrigues Rodolfo , Soares Rafael P. , Secchi Argimiro R. 
Published: April 2009

AbstractNowadays, the use of computational tools in classroom is quite habitual and important by making the learning process more constructive and dynamic. The objective of this work is to introduce a support didactic material for use in computational classes of Chemical Reaction Engineering. The development of the work is based on a direct implementation of examples of the well‐known Fogler's textbook “Elements of Chemical Reaction Engineering” in an equation‐based dynamic simulator: EMSO. The problems were implemented in a way to preserve the structure of the problem as described in the textbook. The results are illustrated by graph plots generated in the simulator, allowing comparisons with the results presented in the textbook and detailed analyses for effects of variables in the problem. The problems are easily modified, allowing the student to analyze several possibilities, changing equations and values of variables, for example, and observing the results. © 2009 Wiley Periodicals, Inc. Comput Appl Eng Educ 18: 607–618, 2010; View this article online at wileyonlinelibrary.com; DOI 10.1002/cae.20255
Tarennanosides A–H, Eight New Lignan Glucosides from Tarenna attenuata and Their Protective Effect on H2O2‐Induced Impairment in PC12 Cells
Authors: Yang Xian‐Wen , He Hong‐Ping , Du Zhi‐Zhi , Liu Hai‐Yang , Di Ying‐Tong , Ma Yan‐Lin , Wang Fang , Lin Hua , Zuo Yi‐Qing , Li Ling , Hao Xiao‐Jiang 
Published: April 2009

Abstractmagnified imageEight new lignan glucosides, tarennanosides A–H (1–8, resp.), were isolated from the whole plant of Tarenna attenuata, together with three known compounds, fernandoside, (−)‐lyoniresinol, and (−)‐isolariciresinol. The planar structures of new compounds were elucidated mainly by analysis of physical and spectroscopic data, and the absolute configurations were determined by acid hydrolysis as well as CD spectroscopy. Compounds 1 and 2 exhibited potent antioxidant activities against H2O2‐induced impairment in PC12 cells. Preliminary mechanism study by the 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) method showed that these two compounds could act as radical scavengers.
Two Unusual Naphthalene‐Containing Compounds from a Freshwater Fungus YMF 1.01029
Authors: Dong Jin‐Yan , Song Hong‐Chuan , Li Jian‐Hua , Wang Chun‐Ren , Sun Rong , Tang Yu‐Shu , Shen Kai‐Ze , Wang Le , Wang Li‐Mei , Zhou Yong‐Ping , Li Lei , Zhang Ke‐Qin 
Published: April 2009

Abstractmagnified imageTwo novel naphthalene‐containing compounds, colelomycerones A and B (1 and 2, resp.), and three known metabolites, including preussomerin D (3), (2RS,2′SR,3′E,3SR,4E,8E)‐1‐O‐(β‐D‐glucopyranosyl)‐3‐hydroxy‐2‐[(2‐hydroxyoctadec‐3‐enoyl)amino]‐9‐methyloctadeca‐4,8‐diene (4), and 3β‐hydroxy‐5α,8α‐epidioxyergosta‐6,22‐diene (5), were isolated from the culture broth of an unidentified freshwater water fungus YMF 1.01029. This fungus was collected from a decaying branch of an unidentified tree near Lake Fuxian in Yunnan Province, China. The structures of these five compounds were determined on the basis of their spectroscopic and mass‐spectrometric data. Colelomycerones A and B (1 and 2, resp.) represent unprecendented examples of naphthalene‐1,2‐diones with novel cyclic acetals. Compounds 1–3 showed noticeable antifungal and antibacterial activities.
Proton Speciation and Microspeciation of Serotonin and 5‐Hydroxytryptophan
Authors: Mazák Károly , Dóczy Veronika , Kökösi József , Noszál Béla 
Published: April 2009

Abstractmagnified imageProtonation equilibria of the neurotransmitter serotonin and its precursor 5‐hydroxytryptophan (5‐HTP) are characterized at the macroscopic and microscopic levels. 1H‐NMR–pH and UV–pH titrations were carried out to determine the macroconstants. Microconstants were obtained by appropriate combination of interactivity parameters and model compounds, allowing the calculation of all the twelve microconstants, the eight microspecies concentrations, and three site‐interactivity parameters of 5‐HTP, for which no microconstants have been reported earlier. NMR–pH Profiles, macro‐ and microscopic protonation schemes, and species‐specific distribution diagrams are presented. The physicochemical data obtained can help to understand the steric and electronic features governing the selectivity of binding and to design new therapeutic agents.
Seasonal Variations in Bioactive Marker Contents in Australian‐Grown Salvia miltiorrhiza Roots
Authors: Sheng Shu Jun , Pang Edwin C. K. , Xue Charlie Chang Li , Li Chun Guang 
Published: April 2009

Abstractmagnified imageSeasonal variations in contents of bioactive markers in Australian‐grown Salvia miltiorrhiza roots were investigated in a two‐year field trial. Cryptotanshinone, tanshinone I, tanshinone IIA, and salvianolic acid B were quantitatively determined by reversed‐phase (RP) HPLC. Similar accumulation patterns were observed for the three tanshinones throughout the trial period, although roots harvested in the first year was found to contain relatively higher contents of these compounds. In contrast, the content of salvianolic acid B was peaked at 250 days after planting in the first year, and subsequently maintained at a plateau level in the second‐year period. Linear correlations between the contents of individual tanshinones were observed, but not between those of tanshinones and salvianolic acid B. The findings suggest that tanshinones and salvianolic acid B have different accumulation patterns in Australian‐grown Salvia miltiorrhiza roots, which should be critically considered for optimum harvesting of the roots for pharmaceutical applications.
Quantitative Structure–Activity Relationship (QSAR) Modeling of Human Blood : Air Partitioning with Proper Statistical Methods and Validation
Authors: Basak Subhash C. , Mills Denise , Hawkins Douglas M. , Kraker Jessica J. 
Published: April 2009

Abstractmagnified imageBlood : air partition coefficient (BApc) is important in assessing toxicokinetics of chemicals. Since very few experimental data are available, quantitative structure–activity relationship (QSAR) models based on calculated molecular descriptors can be useful in estimating BApc. Since all descriptors used in the analysis are computed strictly from structure, they can be applied to any chemical, real or hypothetical. In this article, we report models for BApcestimation using four methods, including stepwise ordinary least‐squares regression, which is commonly used in QSAR studies but often results in an inflated ‘naïve’q2, over‐representing the predictive ability of the model. The models developed using proper statistical techniques hadq2values of 0.825 and 0.841, and may be used to reliably predict BApcvalues for new compounds that are structurally similar to those upon which the models are based. The models developed using improper techniques had associatedq2values, as computed using naïve methods, of 0.920 and 0.934, severely overstating their actual quality.
Anti‐Androgenic Activity of Fatty Acids
Authors: Liu Jie , Shimizu Kuniyoshi , Kondo Ryuichiro 
Published: April 2009

AbstractIn this study, we show that 5α‐reductase derived from rat fresh liver was inhibited by certain aliphatic free fatty acids. The influences of chain length, unsaturation, oxidation, and esterification on the potency to inhibit 5α‐reductase activity were studied. Among the fatty acids we tested, inhibitory saturated fatty acids had C12–C16 chains, and the presence of a CC bond enhanced the inhibitory activity. Esterification and hydroxy compounds were totally inactive. Finally, we tested the prostate cancer cell proliferation effect of free fatty acids. In keeping with the results of the 5α‐reductase assay, saturated fatty acids with a C12 chain (lauric acid) and unsaturated fatty acids (oleic acid and α‐linolenic acid) showed a proliferation inhibitory effect on lymph‐node carcinoma of the prostate (LNCaP) cells. At the same time, the testosterone‐induced prostate‐specific antigen (PSA) mRNA expression was down‐regulated. These results suggested that fatty acids with 5α‐reductase inhibitory activity block the conversion of testosterone to 5α‐dihydrotestosterone (DHT) and then inhibit the proliferation of prostate cancer cells.
Synthesis of (−)‐Epicatechin 3‐(3‐O‐Methylgallate) and (+)‐Catechin 3‐(3‐O‐Methylgallate), and Their Anti‐Inflammatory Activity
Authors: Iijima Takashi , Mohri Yoshihiro , Hattori Yasunao , Kashima Atsushi , Kamo Tsunashi , Hirota Mitsuru , Kiyota Hiromasa , Makabe Hidefumi 
Published: April 2009

Abstractmagnified imageA concise synthesis of (−)‐epicatechin 3‐(3‐O‐methylgallate) (1; ECG3″Me), which is a minor constituent of tea, and (+)‐catechin 3‐(3‐O‐methylgallate) (2; CG3″Me) via condensation of equimolar amount of catechin and gallate derivatives has been achieved. The anti‐inflammatory effect of the synthetic compounds on 12‐O‐tetradecanoylphorbol‐13‐acetate (TPA)‐induced inflammation of mouse ears was examined. Compounds 1 and 2 suppressed the TPA‐induced inflammation of mouse ears by 50 and 43%, respectively, at a dose of 200 μg. Their activities are stronger than those of indomethacin and glycyrrhetinic acid, the normally used anti‐inflammatory agents.
Structure–Activity Relationship Studies on the Mosquito Toxicity and Biting Deterrency of Callicarpenal Derivatives
Authors: Cantrell Charles L. , Klun Jerome A. , Pridgeon Julia , Becnel James , Green Solomon , Fronczek Frank R. 
Published: April 2009

Abstractmagnified imageCallicarpenal (=13,14,15,16‐tetranorclerod‐3‐en‐12‐al=[(1S,2R,4aR,8aR)‐1,2,3,4,4a,7,8,8a‐octahydro‐1,2,4a,5‐tetramethylnaphthalen‐1‐yl]acetaldehyde; 1) has previously demonstrated significant mosquito bite‐deterring activity against Aedes aegypti and Anopheles stephensi in addition to repellent activity against host‐seeking nymphs of the blacklegged tick, Ixodes scapularis. In the present study, structural modifications were performed on callicarpenal (1) in an effort to understand the functional groups necessary for maintaining and/or increasing its activity and to possibly lead to more effective insect control agents. All modifications in this study targeted the C(12) aldehyde or the C(3) alkene functionalities or combinations thereof. Mosquito biting deterrency appeared to be influenced most by C(3) alkene modification as evidenced by catalytic hydrogenation that resulted in a compound having significantly less effectiveness than 1 at a test amount of 25 nmol/cm2. Oxidation and/or reduction of the C(12) aldehyde did not diminish mosquito biting deterrency, but, at the same time, none of the modifications were more effective than 1 in deterring mosquito biting. Toxicities of synthesized compounds towards Ae. aegypti ranged from an LD50 value of 2.36 to 40.11 μg per mosquito. Similarly, LD95 values ranged from a low of 5.59 to a high of 104.9 μg.
Enzymatic Glycosylation of Triazole‐Linked GlcNAc/Glc–Peptides: Synthesis, Stability and Anti‐HIV Activity of Triazole‐Linked HIV‐1 gp41 Glycopeptide C34 Analogues
Authors: Huang Wei , Groothuys Stan , Heredia Alonso , Kuijpers Brian H. M. , Rutjes Floris P. J. T. , van Delft Floris L. , Wang Lai‐Xi 
Published: April 2009

AbstractLong‐lasting sweet proteins: The chemoenzymatic synthesis of a triazole (T)‐linked glycosylated C34 fragment from HIV‐1 gp41 is described. The glycopeptide shows high solubility, excellent fusion inhibition, and as shown in the graph, promising protease resistance.magnified imageEndoglycosidase‐catalyzed transglycosylation of triazole‐linked glucose (Glc) and N‐acetylglucosamine (GlcNAc)‐containing dipeptides and polypeptides was achieved by using synthetic sugar oxazoline as the donor substrate. It was found that both N‐ and C‐linked Glc/GlcNAc‐containing triazole derivatives were effective substrates for endo‐β‐N‐acetylglucosaminidase from Arthrobacter (Endo‐A) for transglycosylation; this demonstrates a broad acceptor substrate specificity for Endo‐A. This chemoenzymatic method was successfully used for the synthesis of a novel triazole‐linked C34 glycopeptide derived from the HIV‐1 envelope glycoprotein, gp41. We found that the synthetic C34 glycopeptide possesses potent anti‐HIV activity with an IC50 of 21 nM. The triazole‐linked C34 glycopeptide demonstrated a much enhanced stability against protease‐ and glycoamidase‐catalyzed digestion; this shows the protective effects of glycosylation and the stability of the triazole linkage. These favorable properties suggest that the triazole‐linked C34 glycopeptide might be valuable for further development as an anti‐HIV drug candidate.
Optimization of an Electrochemical DNA Assay by Using a 48‐Electrode Array and Redox Amplification Studies by Means of Scanning Electrochemical Microscopy
Authors: Neugebauer Sebastian , Zimdars Andreas , Liepold Petra , Gębala Magdalena , Schuhmann Wolfgang , Hartwich Gerhard 
Published: April 2009

AbstractSensible DNA: An electrochemical DNA assay based on specific Salmonella spp. capture probes and enzyme labeling with alkaline phosphatase was optimized by using a 48‐electrode microarray and scanning electrochemical microscopy (SECM). SECM was further used to evaluate potential amplification strategies due to redox cycling.magnified imageDue to insufficient detection limits and selectivity, electrochemical DNA sensors are not yet used as everyday tools in diagnostics. Here, we present an electrochemical DNA assay that is based on specific Salmonella spp. capture probes. Our optimization strategies and the specific features of related electrochemical DNA sensor arrays, which are comprised of a chip with 48 gold electrodes, are also described. A ssDNA monolayer is formed by chemisorption of the thiol‐modified capture strand on the different gold electrodes of the array after spotting with a needle spotter. The assay parameters were optimized for the use of minimum amounts of sample and reagents and short assay times. Scanning electrochemical microscopy (SECM) has been used to visualize the local activity of an enzyme label used for amplified hybridization detection at high lateral resolution. The potential of SECM to further amplify the sensor signal by means of redox cycling is demonstrated by using single‐stranded DNA capture probe modified gold microelectrodes as SECM tips. The detection limit of the proposed DNA sensor is shown to be in the femtomolar range without redox cycling amplification.
Critical review of indications for renal artery stenting: Do randomized trials give the answer?
Authors: Schwarzwälder Uwe , Zeller Thomas 
Published: April 2009

AbstractSignificant renal artery stenosis (RAS) is a well accepted cause of deterioration of arterial hypertension and of renal insufficiency. Just recently, more interest has been focused on the impact of RAS on structural heart disease and patient survival. Technical improvements of diagnostic and interventional endovascular tools have lead to a more widespread use of endoluminal renal artery revascularization and extension of the indications for this type of therapy during the past 2 decades. Since the first renal artery angioplasties performed by Felix Mahler and Andreas Grüntzig, numerous single centre studies have reported the beneficial effect of percutaneous transluminal renal angioplasty, and since the early 1990's stenting of renal artery stenosis caused either by atherosclerosis or fibromuscular dysplasia. However, none of the so far published or presented randomized controlled trials (RCT) could prove a beneficial outcome of RAS revascularization compared with medical management. As a result of these negative trials including the recently presented ASTRAL trial, referrals to endovascular renal artery revascularization went down and moreover, reimbursement of these procedures became a matter of debate. This article summarizes the background and the limitations of the so far published and still ongoing controlled trials. Moreover, we discuss why well‐designed registries might give important insight on the impact of endovascular revascularization of hemodynamically relevant atherosclerotic RAS. © 2009 Wiley‐Liss, Inc.
Preliminary experiences using the MGuard stent platform in saphenous vein graft lesions
Authors: Vaknin‐Assa Hana , Assali Abid , Kornowski Ran 
Published: April 2009

AbstractThe MGuard stent has been designed as a plaque trapping device to treat athero‐thrombotic lesions in saphenous vein grafts and native coronary lesions. It was utilized in seven coronary bypass patients to treat eight vein grafts. The average graft age was 15 years. Procedural success was 100% without any intraprocedural, in‐hospital, and/or 30‐day major adverse cardiac events (e.g. death, myocardial infarction, and need for repeat graft revascularization). No patient experienced distal embolization and/or procedure‐related CK enzymatic rise. This strategy seems to be a promising approach in percutaneous vascular management of vein graft lesions. © 2009 Wiley‐Liss, Inc.
Dobutamine Infusion for Unmasking Long QT Syndrome and Torsades de Pointes
Authors: Quan Fang , Peng Gao , Kangan Cheng , Dayi Hu , Cuilan Li , Richard Conti C. 
Published: April 2009

AbstractProlonged QT interval is usually seen on routine electrocardiogram (ECG), but in some patients it may only be seen immediately before the evolution of torsades de pointes (Tdp). To unmask the potential risk of Tdp in a patient with normal or borderline prolongation of QTc interval and recurrent syncope, dobutamine was given intravenously at a rate of 20 µg/kg/min. Strikingly, QTc prolongation was induced along with syncope after dobutamine infusion. Torsades de pointes occurred 5 d later when the patient received an implantable cardioverter defibrillator (ICD). Genetic testing revealed a mutation of the KNCQ1‐gene encoding serine instead of glycine. The patient was treated with 75 mg of metoprolol twice daily, and at 12 mo follow‐up he had no syncope or chest tightness. The ICD revealed no ventricular tachyarrhythmias or therapy delivered. Copyright © 2009 Wiley Periodicals, Inc.
Comparison of Ischemic Side Effects of Levosimendan and Dobutamine with Integrated Backscatter Analysis
Authors: Duygu Hamza , Nalbantgil Sanem , Zoghi Mehdi , Ozerkan Filiz , Yildiz Ahmet , Akilli Azem , Akin Mustafa 
Published: April 2009

AbstractBackgroundLevosimendan improves cardiac contractility without increasing oxygen consumption. However, its effects on ischemia were not supported with the utilization of a noninvasive parameter of myocardial characterization.HypothesisThe changes observed in integrated backscatter (IBS) may be reflective of change in myocardial ischemia. In this study, the effect of levosimendan on ischemia detected by IBS was evaluated in patients with ischemic heart failure (HF).MethodsPatients who had LVEF < 40% and NYHA III–IV symptoms of HF were included in this study. Patients were randomized to levosimendan (n = 21), or to dobutamine (n = 25) groups. The cyclic variation of integrated backscatter (CVIBS) was determined as the difference between the maximal and minimal values in a cardiac cycle, average of three consecutive beats. CVIBS was taken from the mid‐anteroseptal, mid‐inferior, and mid‐posterolateral areas of the parasternal short axis images before the drug administration and at the end of the 24‐hour infusion period.ResultsBaseline characteristics and concomitant medications were similar in both groups. A significant reduction in CVIBS was detected in anteroseptal (7.6 ± 1.4 dB versus 5.9 ± 0.8 dB,p= 0.01), inferior wall (7.4 ± 0.8 dB versus 6.7 ± 1.5 dB,p= 0.03), and posterolateral wall (9.0 ± 1.2 dB versus 8.2 ± 0.6 dB,p= 0.04) after dobutamine administration, while no significant changes were observed in the levosimendan group in all walls.ConclusionsUnlike dobutamine, levosimendan may not induce myocardial ischemia as shown by CVIBS at commonly used dosages in the setting of decompensated HF without active ischemia. Copyright © 2009 Wiley Periodicals, Inc.
Risk of Stroke and Thrombus Formation From Delay Incontinence of a PLAATO‐Device in Friedreich Ataxia
Authors: Stöllberger Claudia , Finsterer Josef , Avanzini Marion , Mölzer Günther , Weidinger Franz 
Published: April 2009

AbstractWe present the case of a 76‐year‐old female with suspected Friedreich ataxia, in whom leakage and thrombosis of a percutaneously implanted left atrial appendage occluder (PLAATO) was observed 2 years after implantation. Because of late developing leakages and thrombi, regular transesophageal echocardiographic examinations should be carried out in patients with occluded left atrial appendagaes. In view of these complications and the potential important hemodynamic role of the left atrial appendage, the benefit of its occlusion is questionable, and the indications of PLAATO should be strongly reconsidered. Copyright © 2009 Wiley Periodicals, Inc.