bluuebunny/crossref_metadata_2025 huggingface dataset:
Infarct‐like Acute Myocarditis: Relation Between Electrocardiographic Findings and Myocardial Damage as Assessed by Cardiac Magnetic Resonance Imaging
Authors: Nucifora Gaetano , Miani Daniela , Di Chiara Antonio , Piccoli Gianluca , Artico Jessica , Puppato Michela , Slavich Gianaugusto , De Biasio Marzia , Gasparini Daniele , Proclemer Alessandro
Published: December 2012

Background:

Acute myocarditis (AM) may occasionally have an infarct‐like presentation. The aim of the present study was to investigate the relation between electrocardiographic (ECG) findings in this group of patients and myocardial damage assessed by cardiac magnetic resonance imaging (MRI) with the late gadolinium enhancement (LGE) technique.

Hypothesis:

Myocardial damage may be associated with ECG changes in infarct‐like AM.

Methods:

Forty‐one consecutive patients (36 males; mean age, 36 ± 12 years) with diagnosis of AM according to cardiac MRI Lake Louise criteria and infarct‐like presentation were included. The relation between site of ST‐segment elevation (STE), sum of STE (sumSTE), time to normalization of STE, and development of negative T wave with the extent of LGE (expressed as % of left ventricular mass [%LV LGE]), was evaluated.

Results:

Most (80%) patients presented with inferolateral STE; mean sumSTE was 5 ± 3 mm. Normalization of STE occurred within 24 hours in 20 (49%) patients. Development of negative T wave occurred in 28 (68%) patients. Cardiac MRI showed LGE in all patients; mean %LV LGE was 9.6 ± 7.2%. Topographic agreement between site of STE and LGE was 68%. At multivariate analysis, sumSTE (β = 0.42, P < 0.001), normalization of STE >24 hours (β = 0.39, P < 0.001), and development of negative T wave (β = 0.49, P < 0.001) were independently related to %LV LGE.

Conclusions:

Analysis of the site of STE underestimates the extent of myocardial injury among patients with infarct‐like myocarditis. However, some ECG features (ie, sumSTE, normalization of STE >24 hours, and development of negative T wave) may help to identify patients with larger areas of myocardial damage.

The authors have no funding, financial relationships, or conflicts of interest to disclose.
Synthesis and Biological Evaluation of Diaryl‐Substituted Carboranes as Inhibitors of Hypoxia Inducible Factor (HIF)‐1 Transcriptional Activity
Authors: Minegishi Hidemitsu , Matsukawa Takuya , Nakamura Hiroyuki
Published: December 2012

Diaromatic‐substituted ortho‐ and meta‐carboranes were synthesized as mimics of manassantin A. Among the carboranes synthesized, compounds 1 and 2 showed significant inhibition of hypoxia‐induced HIF‐1 transcriptional activity, with IC50 values of 3.2 and 2.2 μM, respectively. Compounds 1 and 2 similarly suppressed hypoxia‐induced HIF‐1α accumulation in a concentration‐dependent manner without affecting the expression level of HIF‐1α mRNA. The hypoxia‐induced accumulation and translocation of HIF‐1α into nuclei were not observed in HeLa cells treated with compounds 1 and 2 by immunofluorescence analysis, revealing that the inhibition of hypoxia‐induced HIF‐1 transcriptional activity is induced by compounds 1 and 2 through a degradation pathway of the HIF‐1α protein under hypoxic conditions.
Butyltin(IV) Benzoates: Inhibition of Thioredoxin Reductase, Tumor Cell Growth Inhibition, and Interactions with Proteins
Authors: Navakoski de Oliveira Kely , Andermark Vincent , von Grafenstein Susanne , Onambele Liliane A. , Dahl Gregor , Rubbiani Riccardo , Wolber Gerhard , Gabbiani Chiara , Messori Luigi , Prokop Aram , Ott Ingo
Published: December 2012

Thioredoxin reductase (TrxR) is overexpressed in cancer cells and is therefore a putative cancer target. Inhibition of this enzyme is considered an important strategy for the development of new chemotherapeutic agents with a specific mechanism of action. Organotin compounds have been described as experimental antitumor agents, yet their mechanism of action remains largely unknown. Based on the outcome of a virtual screening study, various di‐ and tri‐n‐butyltin(IV) carboxylates were synthesized, and their biological properties were evaluated. All synthesized compounds were able to inhibit TrxR selectively within the micromolar range and showed potent antitumor activity against HT‐29 and MCF‐7 cancer cell lines. Moreover, tin(IV) organometallics were found to strongly induce apoptosis in the BJAB lymphoma cell line. Mass spectrometry and atomic absorption spectroscopy experiments revealed metal binding to proteins, and efficient cellular uptake was observed using a di‐n‐butyltin(IV) complex as an example.
How to Tickle Spins with a Fourier Transform NMR Spectrometer
Authors: Segawa Takuya F. , Carnevale Diego , Bodenhausen Geoffrey
Published: December 2012

In the long bygone days of continuous‐wave nuclear magnetic resonance (NMR) spectroscopy, a selected transition within a multiplet of a high‐resolution spectrum could be irradiated by a highly selective continuous‐wave (CW) radio‐frequency (rf) field with a very weak amplitude ${\omega _2 }$/(2π)≤J. This causes splittings of connected transitions, allowing one to map the connectivities of all transitions within the energy‐level diagram of the spin system. Such “tickling” experiments stimulated the invention of two‐dimensional spectroscopy, but seem to have been forgotten for nearly 50 years. We show that tickling can readily be achieved in homonuclear systems with Fourier transform spectrometers by applying short pulses in the intervals between the sampling points. Extensions to heteronuclear systems are even more straightforward since they can be carried out using very weak CW rf fields.
Debinding Mechanisms in Thermoplastic processing of a Ba0.5Sr0.5Co0.8Fe0.2O3−δ‐ Stearic Acid–Polystyrene Mixture
Authors: Salehi Mehdi , Clemens Frank , Otal Eugenio H. , Ferri Davide , Graule Thomas , Grobéty Bernard
Published: December 2012

In the present study, we address the interaction between a thermoplastic binder system and Ba0.5Sr0.5Co0.8Fe0.2O3−δ (BSCF) during thermal treatment of the thermoplastic feedstock. BSCF powder was coated with different amounts of stearic acid (SA) acting as a surfactant. Oxygen release from the uncoated BSCF surface changes the decomposition of polystyrene (PS) in inert atmospheres from a pyrolytic to a thermoxidative mechanism, thereby decreasing the break‐down temperature and the activation energy. In mixtures with coated BSCF powder, the decomposition products of SA carbonatize the BSCF surface, which inhibits oxygen release. Mass spectrometry of the breakdown products indicates that the decomposition of SA in the presence of BSCF also modifies the decomposition pathway of PS. The influence of BSCF on the polymer decomposition reaction in air is not as strong. Oxygen diffusion seems to be responsible for the differences to pure PS in reaction rates and the activation energies.
Structural and Photoelectrochemical Evaluation of Nanotextured Sn‐Doped AgInS2 Films Prepared by Spray Pyrolysis
Authors: Cheng Qian , Peng Xihong , Chan Candace K.
Published: December 2012

Spray pyrolysis was used to prepare films of AgInS2 (AIS) with and without Sn as an extrinsic dopant. The photoelectrochemical performance of these films was evaluated after annealing under a N2 or S atmosphere with different amounts of the Sn dopant. DFT was used to calculate the band structure of AIS and understand the role of Sn doping in the observed properties. All AIS films were n‐type, and Sn was found to increase the photocurrent and carrier concentration of AIS with an optimum doping level of x=[Sn]/([Ag]+[In])=0.02, which gave a photocurrent of 4.85 mA cm−2. Above this level, the Sn dopants were detrimental to the photoelectrochemical performance, likely a result of a self‐compensating effect and the introduction of a deep acceptor level, which could act as a recombination site for photogenerated carriers.
Ordered Mesoporous Tungsten Suboxide Counter Electrode for Highly Efficient Iodine‐Free Electrolyte‐Based Dye‐Sensitized Solar Cells
Authors: Jeong Inyoung , Jo Changshin , Anthonysamy Arockiam , Kim Jung‐Min , Kang Eunae , Hwang Jongkook , Ramasamy Easwaramoorthi , Rhee Shi‐Woo , Kim Jin Kon , Ha Kyoung‐Su , Jun Ki‐Won , Lee Jinwoo
Published: December 2012

A disulfide/thiolate (T2/T−) redox‐couple electrolyte, which is a promising iodine‐free electrolyte owing to its transparent and noncorrosive properties, requires alternative counter‐electrode materials because conventional Pt shows poor catalytic activity in such an electrolyte. Herein, ordered mesoporous tungsten suboxide (m‐WO3−x), synthesized by using KIT‐6 silica as a hard template followed by a partial reduction, is used as a catalyst for a counter electrode in T2/T−‐electrolyte‐based dye‐sensitized solar cells (DSCs). The mesoporous tungsten suboxide, which possesses interconnected pores of 4 and 20 nm, provides a large surface area and efficient electrolyte penetration into the m‐WO3−x pores. In addition to the advantages conferred by the mesoporous structure, partial reduction of tungsten oxide creates oxygen vacancies that can function as active catalytic sites, which causes a high electrical conductivity because of intervalence charge transfer between the W5+ and W6+ ions. m‐WO3−x shows a superior photovoltaic performance (79 % improvement in the power conversion efficiency) over Pt in the T2/T− electrolyte. The superior catalytic activity of m‐WO3−x is investigated by using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and Tafel polarization curve analysis.
Production of Hybrid Diesel Fuel Precursors from Carbohydrates and Petrochemicals Using Formic Acid as a Reactive Solvent
Authors: Zhou Xiaoyuan , Rauchfuss Thomas B.
Published: December 2012

We report the one‐pot alkylation of mesitylene with carbohydrate‐derived 5‐(hydroxymethyl)furfural (HMF) as a step toward diesel‐range liquids. Using FeCl3 as a catalyst, HMF is shown to alkylate toluene, xylene, and mesitylene in high yields in CH2Cl2 and MeNO2 solvents. Efforts to extend this reaction to greener or safer solvents showed that most ether‐based solvents are unsatisfactory. Acid catalysts (e.g, p‐TsOH) also proved to be ineffective. Using formic acid as a reactive solvent, mesitylene could be alkylated to give mesitylmethylfurfural (MMF) starting from fructose with yields up to approximately 70 %. The reaction of fructose with formic acid in the absence of mesitylene gave rise to low yields of the formate ester of HMF, which indicates the stabilizing effect of replacing the hydroxyl substituent with mesityl. The arene also serves as a second phase into which the product is extracted. Even by using formic acid, the mesitylation of less expensive precursors such as glucose and cellulose proceeded only in modest yields (ca. 20 %). These simpler substrates were found to undergo mesitylation by using hydrogen chloride/formic acid via the intermediate chloromethylfurfural.
Occupational exposures to aluminum and iron and risk of lung epithelium atypia in sudan
Authors: Ahmed Hussain Gadelkarim , Mahmoud Tagreed Ahmed , Ginawi Ibrahim A.
Published: December 2012

This study investigated the risk of lung cytological atypical changes in regards to occupational exposure to aluminum and iron. Detailed job histories were elicited from 130 incident cases with confirmed exposure to aluminum (50) or iron (80) and 157 population controls (nonexposed). Cytological atypia in sputum (dysplasia) was identified in four cases and none of controls (RR =10.8550; 95% CI = 0.5898 to 199.7815, P = 0.1086), hence, metaplasia was observed among 15 (11.5%) of the cases and 10 (6%) of controls (RR = 1.8115; 95% CI = 0.8424–3.8956; P = 0.1283). Evidences of viral infection were observed in 18 (14%) of the cases and 8 (5%) of controls (RR = 2.7173; 95% CI = 1.2213–6.0460; P = 0.0143). Moniliasis was observed in 28 (22%) of the cases and 19 (12%) of controls (RR = 1.6632; 95% CI = 0.9728–2.8435; P = 0.06). Cross‐categorizations of aluminum exposure and iron use suggest greater risk associated with iron exposure than aluminum in these workers. Diagn. Cytopathol. 2013. © 2012 Wiley Periodicals, Inc.
Electrochemical Immunosensor for Ultrasensitive Detection of Human Chorionic Gonadotropin Based on Pd@SBA‐15
Authors: Wu Dan , Zhang Yong , Shi Li , Cai Yanyan , Ma Hongmin , Du Bin , Wei Qin
Published: December 2012

A simple and sensitive electrochemical immunosensor was conducted for the determination of human chorionic gonadotropin (hCG) with Pd@SBA‐15. Thionine (TH) was selected as an electron transfer mediator, and modified onto the electrode together with functionalized graphene nanomaterial (HSO3−GS) through electrostatic adsorption. Then Pd@SBA‐15 was immobilized onto the as‐prepared film for biomolecules anchoring. Pd@SBA‐15 composites not only retain the good biocompatibility of the SBA‐15, but also exhibit an excellent catalytic activity of Pd and low Pd leaching. hCG antibody was immobilized onto the composite film for the detection of hCG. hCG can be determined in the range of 0.01–16.00 ng/mL and the detection limit is 8.60 pg/mL. The method has been applied to the analysis of hCG in human serum samples with satisfactory results.
Multiwalled Carbon Nanotubes Modified by NTA‐Copper Complex for Label‐Free Electrochemical Immunosensor Detection
Authors: Chebil S. , Macauley N. , Hianik T. , Korri‐Youssoufi H.
Published: December 2012

A biomaterial based on multiwalled carbon nanotubes (MWCNTs) modified with His‐tagged single chain D‐dimer antibody trough nitrilo‐triacetic‐acid (NTA)/copper complex was designed for monitoring D‐dimers, which were used as biomarkers of Deep Vein Thrombosis (DVT). The immunosensing evaluation of D‐Dimer was followed by measuring the redox process of such complex. We demonstrate that using simple chemistry and exploiting the high surface area, electronic properties of MWCNTs and redox signal of the NTA/Cu2+ complex an efficient electrochemical immunosensor for the evaluation of wide range of D‐dimer concentrations was obtained.
Hybridization Detection of Osmium Tetroxide Bipyridine‐Labeled DNA and RNA on Heated Gold Wire Electrodes
Authors: Jacobsen Martin , Flechsig Gerd‐Uwe
Published: December 2012

We report about hybridization detection of different nucleic acids on capture probe‐modified heated gold wire electrodes. We have compared three kinds of nucleic acid targets: DNA, uracil‐conjugated DNA, and RNA. All three sorts of nucleic acids targets could be labeled with osmium tetroxide bipyridine, hybridized with immobilized DNA capture probes and then detected by square‐wave voltammetry. Heating the gold electrode instead of the entire bulk hybridization solution leads to improved hybridization efficiency in most cases. The reason could be found in a thermal micro‐stirring effect around the heated wire electrode. Also selectivity was improved. Mismatches could be discriminated for DNA and uracil‐conjugated DNA targets. Mismatches in RNA strands, however, are more difficult to detect due to relatively stable secondary structures.
Simultaneous Determination of Antimony(III) and Molybdenum(VI) by Adsorptive Stripping Voltammetry Using Quercetin as Complexing Agent
Authors: Rojas Carlos , Arancibia Verónica , Gómez Marisol , Nagles Edgar
Published: December 2012

A sensitive and selective voltammetric method for simultaneous determination of Sb(III) and Mo(VI) using Quercetin (Q) as complexing agent is described. Optimal conditions were found to be: pH 3.7, CQ=6.0 µmol L−1 and Eacc=−0.10 V. The LOD (3σ) for Sb(III) are 0.076 and 0.040 µg L−1, whereas for Mo(VI) are 0.086 and 0.048 µg L−1 with tacc of 60 and 120 s, respectively. The method was validated using synthetic sea water (ASTM D665) and was applied to the determination of Sb(III) and Mo(VI) in natural waters with satisfactory results.
Label‐Free Analysis of Thrombin or Hg2+ Ions by Nucleic Acid‐Functionalized Graphene Oxide Matrices Assembled on Field‐Effect Transistors
Authors: Sharon Etery , Liu Xiaoqing , Freeman Ronit , Yehezkeli Omer , Willner Itamar
Published: December 2012

Graphene oxide (GO) is deposited onto the Al2O3 gates of field‐effect transistor devices to yield a functional matrix for the sensing of thrombin or Hg2+ ions. The deposition of an aptamer subunit against thrombin or a tailored nucleic acid with appropriate T mismatches on the GO, yield active surfaces for the analysis of thrombin or Hg2+ ions. The desorption of the aptamer‐subunit from GO, through the formation of the aptamer‐thrombin complex, or the desorption of the T–Hg2+–T‐bridged duplex DNA alter the gate potential, thus providing a signal for the sensing events.
Economic Comparison of Continuous and Batch Production of Biodiesel Using Soybean Oil
Authors: Benavides Pahola T. , Salazar Juan , Diwekar Urmila
Published: December 2012

The Lawrence K. Cecil Award in Environmental Chemical Engineering recognizes an individual's outstanding chemical engineering contribution and achievement in the preservation or improvement of the environment. The recipient must be a member of AIChE, have 15 years of chemical engineering experience in the environmental field, and demonstrate leadership in research, teaching, engineering, or regulatory activities in either the public or private sector. The award is presented annually by the Environmental Division. This paper was prepared by the 2011 Cecil Award recipient based on work presented at the AIChE national meeting in Minneapolis.
Sensorial evolution of cassava flour (Manihot esculenta crantz) added to protein concentrate cassava leaves
Authors: Lima Elaine C. S. , Feijo Márcia B. S. , Freitas Maria C. J. , dos Santos Edna R. , Sabaa‐Srur Armando U. O. , Moura Luciana S. M.
Published: December 2012

Cassava is regarded as the nutritional base of populations in developing countries, and flour, product made of cassava, is the most consumed in the world. The cassava leaves are very rich in vegetable proteins, but a big amount is lost in processing the crop. The objective of this study was to do a sensory evaluation of cassava flour to which a protein concentrate obtained from cassava leaves (CPML) was added. The CPML was obtained from cassava leaves by isoelectric precipitation and added to cassava paste for preparation of flour in three parts 2.5, 5, and 10%. The acceptance test was done by 93 consumers of flour, using hedonic scale of 7 points to evaluate characteristics like color, scent, flavor, bitterness, texture, and overall score. By the method of quantitative descriptive analysis (QDA), eight trained tasters evaluated the following characteristics: whitish color, greenish color, cassava flavor, bitter flavor, characteristic flavor, lumpiness, raw texture, leaf scent, and cassava scent. The acceptability test indicated that flour cassava with 2.5 was preferred. Whitish color, greenish color, cassava flavor, bitter flavor, salty flavor, characteristic flavor, lumpiness texture, raw texture, and the smell of the leaves and cassava flour were the main descriptors defined for flour cassava with CPML has better characteristics.
Chemical characterization of commercial liquid smoke products
Authors: Montazeri Naim , Oliveira Alexandra C. M. , Himelbloom Brian H. , Leigh Mary Beth , Crapo Charles A.
Published: December 2012

The objective of this study was to determine important chemical characteristics of a full‐strength liquid smoke, Code 10‐Poly, and three refined liquid smoke products (AM‐3, AM‐10 and 1291) commercially available (Kerry Ingredients and Flavors, Monterey, TN). The pH of the products were significantly different (P < 0.05) and ranged from 2.3 (Code 10‐Poly) to 5.7 (1291). The pH was inversely correlated with titratable acidity (R2 = 0.87), which was significantly different (P < 0.05) among products ranging from 10.3% acetic acid (Code 10‐Poly) to 0.7% acetic acid (1291). Total phenol content was quantified using the Gibbs reaction; the only liquid smoke containing appreciable level of phenolic compounds was Code 10‐Poly at 3.22 mg mL−1. Gas chromatography‐mass spectrometry (GC‐MS) analysis of liquid smoke dichloromethane extracts revealed that carbonyl‐containing compounds were major constituents of all products, in which 1‐hydroxy‐2‐butanone, 2(5H)‐furanone, propanal and cyclopentenone predominated. Organic acids were detected by GC‐MS in all extracts and correlated positively (R2 = 0.98) with titratable acidity. The GC‐MS data showed that phenolic compounds constituted a major portion of Code 10‐Poly, and were detected only in trace quantities in 1291. The refined liquid smokes had lighter color, lower acidity, and reduced level of carbonyl‐containing compounds and organic acids. Our study revealed major differences in pH, titratable acidity, total phenol content, color and chemical make‐up of the full‐strength and refined liquid smokes. The three refined liquid smoke products studied have less flavor and color active compounds, when compared with the full‐strength product. Furthermore, the three refined products studied have unique chemical characteristics and will impart specific sensorial properties to food systems. Understanding the chemical composition of liquid smokes, be these refined or full‐strength products, is an important step to establish their functions and appropriate use in food systems.
Polymorphisms of the Core, NS3, and NS5a Proteins of Hepatitis C Virus Genotype 1b Associate With Development of Hepatocellular Carcinoma
Authors: El-Shamy Ahmed , Shindo Michiko , Shoji Ikuo , Deng Lin , Okuno Tadao , Hotta Hak
Published: December 2012

Hepatocellular carcinoma (HCC) is one of the common sequelae of hepatitis C virus (HCV) infection. It remains controversial, however, whether HCV itself plays a direct role in the development of HCC. Although HCV core, NS3, and NS5A proteins were reported to display tumorigenic activities in cell culture and experimental animal systems, their clinical impact on HCC development in humans is still unclear. In this study we investigated sequence polymorphisms in the core protein, NS3, and NS5A of HCV genotype 1b (HCV-1b) in 49 patients who later developed HCC during a follow-up of an average of 6.5 years and in 100 patients who did not develop HCC after a 15-year follow-up. Sequence analysis revealed that Gln at position 70 of the core protein (core-Gln70), Tyr at position 1082 plus Gln at 1112 of NS3 (NS3-Tyr1082/Gln1112), and six or more mutations in the interferon/ribavirin resistance-determining region of NS5A (NS5A-IRRDR≥6) were significantly associated with development of HCC. Multivariate analysis identified core-Gln70, NS3-Tyr1082/Gln1112, and α-fetoprotein (AFP) levels (>20 ng/L) as independent factors associated with HCC. Kaplan-Meier analysis revealed a higher cumulative incidence of HCC for patients infected with HCV isolates with core-Gln70, NS3-Tyr1082/Gln1112 or both than for those with non-(Gln70 plus NS3-Tyr1082/Gln1112). In most cases, neither the residues at position 70 of the core protein nor positions 1082 and 1112 of the NS3 protein changed during the observation period.

Conclusion

: HCV isolates with core-Gln70 and/or NS3-Tyr1082/Gln1112 are more closely associated with HCC development compared to those with non-(Gln70 plus NS3-Tyr1082/Gln1112). (HEPATOLOGY 2013;58:555-563)
Brahma-Related Gene 1 Bridges Epigenetic Regulation of Proinflammatory Cytokine Production to Steatohepatitis in Mice
Authors: Tian Wenfang , Xu Huihui , Fang Fei , Chen Qi , Xu Yong , Shen Aiguo
Published: December 2012

Chronic inflammation, inflicted by the spillover of proinflammatory mediators, links metabolic dysfunction to nonalcoholic steatohepatitis (NASH). The epigenetic maneuverings that underscore accelerated synthesis of proinflammatory mediators in response to nutritional inputs are not clearly defined. Here we report that the ATP-dependent chromatin remodeling proteins Brahma-related gene 1 (Brg1) and Brahma (Brm) were up-regulated

in vitro

in cultured hepatocytes treated with free fatty acid or glucose and

in vivo

in animal models of NASH. Occupancy of Brg1 and Brm on the promoter regions of proinflammatory genes was increased

in vitro

in cells and

ex vivo

in liver tissues. Estradiol suppressed the induction and recruitment of Brg1/Brm by palmitate. Recruitment of Brg1 and Brm relied on nuclear factor kappa B/p65; reciprocally, Brg1 and Brm contributed to the stabilization of p65 binding. Importantly, overexpression of Brg1/Brm enhanced, whereas knockdown of Brg1/Brm attenuated, the induction of proinflammatory mediators in hepatocytes challenged with excessive nutrient. Mechanistically, Brg1 and Brm were involved in the maintenance of a chromatin microenvironment marked by active histone modifications and friendly to the access of the general transcriptional machinery. Finally, depletion of Brg1/Brm by short hairpin RNA attenuated the release of proinflammatory mediators in the liver and significantly ameliorated hepatic pathology in NASH mice.

Conclusion

: Our data illustrate a Brg1-dependent pathway that connects the epigenetic regulation of proinflammatory genes to the pathogenesis of NASH and point to a potential druggable target in the therapeutic intervention of NASH. (HEPATOLOGY 2013;58:576–588)
Quantitative proteomics: A strategic ally to map protein interaction networks
Authors: Marcilla Miguel , Albar Juan Pablo
Published: December 2012

Many physiological processes are regulated by dynamic protein interaction networks whose characterization provides valuable information on cell biology. Several strategies can be used to analyze protein–protein interactions. Among them, affinity purification combined with mass spectrometry (AP‐MS) is arguably the most widely employed technique, not only owing to its high throughput and sensitivity but also because it can answer critical questions such as where, when, and how protein–protein interactions occur. In AP‐MS workflows, both the target protein and its interacting partners are isolated before being identified by MS. The main challenge of this approach is to distinguish bona fide binders from background contaminants. This review focuses on the different strategies designed to circumvent this limitation. In this regard, the combination of quantitative proteomics and affinity purification emerges as one of the most powerful, yet relatively simple, strategies to characterize protein–protein interactions. © IUBMB Life, 65(1):9–16, 2013
Internal friction in enzyme reactions
Authors: Rauscher Anna , Derényi Imre , Gráf László , Málnási‐Csizmadia András
Published: December 2012

The empirical concept of internal friction was introduced 20 years ago. This review summarizes the results of experimental and theoretical studies that help to uncover the nature of internal friction. After the history of the concept, we describe the experimental challenges in measuring and interpreting internal friction based on the viscosity dependence of enzyme reactions. We also present speculations about the structural background of this viscosity dependence. Finally, some models about the relationship between the energy landscape and internal friction are outlined. Alternative concepts regarding the viscosity dependence of enzyme reactions are also discussed. ©2012 IUBMB Life, 65(1):35–42, 2013
Structure analysis of the global metabolic regulator Crc from Pseudomonas aeruginosa
Authors: Wei Yong , Zhang Heng , Gao Zeng‐Qiang , Xu Jian‐Hua , Liu Quan‐Sheng , Dong Yu‐Hui
Published: December 2012

The global metabolic regulator catabolite repression control (Crc) has recently been found to modulate the susceptibility to antibiotics and virulence in the opportunistic pathogen Pseudomonas aeruginosa and been suggested as a nonlethal target for novel antimicrobials. In P. aeruginosa, Crc couples with the CA motifs from the small RNA CrcZ to form a post‐transcriptional regulator system and is removed from the 5′‐end of the target mRNAs. In this study, we first reported the crystal structure of Crc from P. aeruginosa refined to 2.20 Å. The structure showed that it consists of two halves with similar overall topology and there are 11 β strands surrounded by 13 helices, forming a four‐layered α/β‐sandwich. The circular dichroism spectroscopy revealed that it is thermostable in solution and shares similar characteristics to that in crystal. Comprehensive structural analysis and comparison with the homologies of Crc showed high similarity with several known nucleases and consequently may be classified into a member exodeoxyribonuclease III. However, it shows distinct substrate specificity (RNA as the preferred substrate) compared to these DNA endonucleases. Structural comparisons also revealed potential RNA recognition and binding region mainly consisting of five flexible loops. Our structure study provided the basis for the future application of Crc as a target to develop new antibiotics. © 2012 IUBMB Life, 65(1):50–57, 2013
Recombinant human CXCL8(3‐72)K11R/G31P regulates smooth muscle cell proliferation and migration through blockage of interleukin‐8 receptor
Authors: Qin YuanHua , Fan FuShun , Zhao Ying , Cui Ying , Wei XiaoQing , Kohama Kazuhiro , Gordon John R. , Li Fang , Gao Ying
Published: December 2012

Atherosclerosis is a chronic inflammatory disease with multiple contributing factors. Hyperlipidemia is one of the major independent risks, and interleukin‐8 (IL‐8), as an inflammatory factor, plays an important role in the development of atherosclerosis. The aims of the study were to examine the therapeutic efficacy of G31P, an antagonist of IL‐8 receptor, with a mouse model of hyperlipidemia and the potential mechanisms of G31P through the vascular smooth muscle cell (VSMC) proliferation and migration in a cell line. In vivo study: Male BALB/c mice were fed a high‐fat diet for 6 months. G31P was injected subcutaneously. Blood keratinocyte chemoattractant, lipid profile, and aorta expression of inflammatory factors, matrix metalloproteinases, MMP2 and MMP9 were investigated. In vitro study: A7R5 cells were treated with IL‐8 with/without G31P. Cell proliferation and migration were investigated. G31P significantly suppressed the hyperlipidermia‐induced abnormal lipid profile and increased IL‐8, proinflammatory factor, MMP2 and MMP9 expression. G31P also inhibited VSMC proliferation and migration both in vitro and in vivo. These findings indicate the potential therapeutic effects of G31P in preventing the development of atherosclerosis by antagonizing IL‐8 receptor and decreasing the biologic activity of IL‐8. © 2012 IUBMB Life, 65(1):67–75, 2013
Toward an understanding of immune cell sociology: real‐time monitoring of cytokine secretion at the single‐cell level
Authors: Shirasaki Yoshitaka , Yamagishi Mai , Shimura Nanako , Hijikata Atsushi , Ohara Osamu
Published: December 2012

The immune system is a very complex and dynamic cellular system, and its intricacies are considered akin to those of human society. Disturbance of homeostasis of the immune system results in various types of diseases; therefore, the homeostatic mechanism of the immune system has long been a subject of great interest in biology, and a lot of information has been accumulated at the cellular and the molecular levels. However, the sociological aspects of the immune system remain too abstract to address because of its high complexity, which mainly originates from a large number and variety of cell–cell interactions. As long‐range interactions mediated by cytokines play a key role in the homeostasis of the immune system, cytokine secretion analyses, ranging from analyses of the micro level of individual cells to the macro level of a bulk of cell ensembles, provide us with a solid basis of a sociological viewpoint of the immune system. In this review, as the first step toward a comprehensive understanding of immune cell sociology, cytokine secretion of immune cells is surveyed with a special emphasis on the single‐cell level, which has been overlooked but should serve as a basis of immune cell sociology. Now that it has become evident that large cell‐to‐cell variations in cytokine secretion exist at the single‐cell level, we face a tricky yet interesting question: How is homeostasis maintained when the system is composed of intrinsically noisy agents? In this context, we discuss how the heterogeneity of cytokine secretion at the single‐cell level affects our view of immune cell sociology. While the apparent inconsistency between homeostasis and cell‐to‐cell heterogeneity is difficult to address by a conventional reductive approach, comparison and integration of single‐cell data with macroscopic data will offer us a new direction for the comprehensive understanding of immune cell sociology. © 2012 IUBMB Life, 65(1):28–34, 2013
Opportunities for protein interaction network‐guided cellular engineering
Authors: Wright Phillip C. , Jaffe Stephen , Noirel Josselin , Zou Xin
Published: December 2012

As we move further into the postgenomics age where the mountain of systems biology‐generated data keeps growing, as does the number of genomes that have been sequenced, we have the exciting opportunity to understand more deeply the biology of important systems, those that are amenable to genetic manipulation and metabolic engineering. This is, of course, if we can make ‘head or tail’ of what we have measured and use this for robust predictions. The use of modern mass spectrometry tools has greatly facilitated our understanding of which proteins are present in a particular phenotype, their relative and absolute abundances and their state of modifications. Coupled with modern bioinformatics and systems biology modelling tools, this has the opportunity of not just providing information and understanding but also to provide targets for engineering and suggest new genetic/metabolic designs. Cellular engineering, whether it be via metabolic engineering, synthetic biology or a combination of both approaches, offers exciting potential for biotechnological exploitation in fields as diverse as medicine and energy as well as fine and bulk chemicals production. At the heart of such effective designs, proteins' interactions with other proteins or with DNA will become increasingly important. In this work, we examine the work done until now in protein–protein interactions and how this network knowledge can be used to inform ambitious cellular engineering strategies. Some examples demonstrating small molecules/biofuels and biopharmaceuticals applications are presented. © 2012 IUBMB Life, 65(1):17–27, 2013
Artificial lymphatic drainage systems for vascularized microfluidic scaffolds
Authors: Wong Keith H. K. , Truslow James G. , Khankhel Aimal H. , Chan Kelvin L. S. , Tien Joe
Published: December 2012

The formation of a stably perfused microvasculature continues to be a major challenge in tissue engineering. Previous work has suggested the importance of a sufficiently large transmural pressure in maintaining vascular stability and perfusion. Here we show that a system of empty channels that provides a drainage function analogous to that of lymphatic microvasculature in vivo can stabilize vascular adhesion and maintain perfusion rate in dense, hydraulically resistive fibrin scaffolds in vitro. In the absence of drainage, endothelial delamination increased as scaffold density increased from 6 to 30 mg/mL and scaffold hydraulic conductivity decreased by a factor of 20. Single drainage channels exerted only localized vascular stabilization, the extent of which depended on the distance between vessel and drainage as well as scaffold density. Computational modeling of these experiments yielded an estimate of 0.40–1.36 cm H2O for the minimum transmural pressure required for vascular stability. We further designed and constructed fibrin patches (0.8 × 0.9 cm2) that were perfused by a parallel array of vessels and drained by an orthogonal array of drainage channels; only with the drainage did the vessels display long‐term stability and perfusion. This work underscores the importance of drainage in vascularization, especially when a dense, hydraulically resistive scaffold is used. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2013.
Enzymatic saccharification of acid–alkali pretreated sugarcane bagasse using commercial enzyme preparations
Authors: Giese Ellen C. , Pierozzi Maurício , Dussán Kelly J. , Chandel Anuj K. , da Silva Silvio S.
Published: December 2012

Background

The bioconversion of lignocellulosic biomass to second generation ethanol has the potential to replace some fossil fuels. Sugarcane bagasse (SB) is a readily available feedstock for ethanol production. The aim of this work was to study the enzymatic saccharification of consecutively acid–alkali pretreated SB using different commercial enzyme preparations.

Results

Under the most favourable enzymatic hydrolysis conditions, a maximum sugar recovery of 0.89 g of reducing sugars g‐1 acid–alkali pretreated SB was obtained. Scanning electron microscopy (SEM) revealed the structural disruption in the SB morphology after acid–alkali pretreatment followed by enzymatic hydrolysis.

Conclusion

These results improve research strategies and show the susceptibility of SB under different enzymatic actions. This is thought to be the first report on utilization of cellulase AF28918 for SB saccharification into fermentable sugars.
Three‐Dimensional Locations of Destinations Have Species‐Dependent Effects on the Choice of Paths and the Gap‐Bridging Performance of Arboreal Snakes
Authors: Hoefer K. Marie , Jayne Bruce C.
Published: December 2012

Challenges for moving in arboreal environments include sizable gaps and variable three‐dimensional locations between the discrete destinations created by branches. Different three‐dimensional orientations of the body change the mechanical demands of crossing gaps, especially for elongate animals, but these effects on both the maximal gap distance crossed (Gapmax) and the choice of destinations are poorly understood despite many animals frequently encountering these circumstances. We tested and compared the effects of three‐dimensional gap location on the bridging ability of three species of snakes with similar length but moderately stout (Boa constrictor), intermediate (Pantherophis guttatus) or slender (Boiga irregularis) shapes, and we tested for bias in choice of destinations for the latter two species. The effects of both gap location and species on Gapmax were highly significant, and the rank order of species from greatest to least Gapmax was often from the most slender to the stoutest species. Although the effects of yaw (horizontal) angles were statistically significant, they were small compared to those of pitch (vertical) angles, which created nearly twofold variation in the values of Gapmax within each species. The greatest values of Gapmax occurred when snakes went straight down. Within a horizontal plane, P. guttatus and B. irregularis had similar preferences for choosing gaps with smaller yaw angles. However, when pitch angle was varied, P. guttatus preferred lower destinations, whereas B. irregularis preferred higher destinations. Thus, despite quite uniform effects of gap location on bridging abilities and torques acting on the animals, some preferences for locations were species specific. J. Exp. Zool. 319A:124–137, 2013. © 2012 Wiley Periodicals, Inc.
Effect of wind energy development on breeding duck densities in the Prairie Pothole Region
Authors: Loesch Charles R. , Walker Johann A. , Reynolds Ronald E. , Gleason Jeffrey S. , Niemuth Neal D. , Stephens Scott E. , Erickson Michael A.
Published: December 2012

Industrial wind energy production is a relatively new phenomenon in the Prairie Pothole Region and given the predicted future development, it has the potential to affect large land areas. The effects of wind energy development on breeding duck pair use of wetlands in proximity to wind turbines were unknown. During springs 2008–2010, we conducted surveys of breeding duck pairs for 5 species of dabbling ducks in 2 wind energy production sites (wind) and 2 paired reference sites (reference) without wind energy development located in the Missouri Coteau of North Dakota and South Dakota, USA. We conducted 10,338 wetland visits and observed 15,760 breeding duck pairs. Estimated densities of duck pairs on wetlands in wind sites were lower for 26 of 30 site, species, and year combinations and of these 16 had 95% credible intervals that did not overlap zero and resulted in a 4–56% reduction in breeding pairs. The negative median displacement observed in this study (21%) may influence the prioritization of grassland and wetland resources for conservation when existing decision support tools based on breeding‐pair density are used. However, for the 2 wind study sites, priority was not reduced. We were unable to directly assess the potential for cumulative impacts and recommend long‐term, large‐scale waterfowl studies to reduce the uncertainty related to effects of broad‐scale wind energy development on both abundance and demographic rates of breeding duck populations. In addition, continued dialogue between waterfowl conservation groups and wind energy developers is necessary to develop conservation strategies to mitigate potential negative effects of wind energy development on duck populations. Published 2012. This article is a U.S. Government work and is in the public domain in the USA.
Factors influencing the reaction of mountain goats towards all‐terrain vehicles
Authors: St‐Louis Antoine , Hamel Sandra , Mainguy Julien , Côté Steeve D.
Published: December 2012

The increasing popularity of recreational activities in the wild has led to concerns about their potential impacts on wildlife. All‐terrain vehicles (ATVs) often bring people into wildlife habitats, where they may disturb animal populations. We assessed the influence of ATVs on the behavior of mountain goats (Oreamnos americanus) in a long‐term study population at Caw Ridge, Alberta, Canada. We used multinomial models containing environment‐, disturbance‐, and group‐related factors, to evaluate the response of mountain goats to the approach of ATVs. Goats were moderately to strongly disturbed by ATVs 44% of the time, and disturbance levels were mainly influenced by the direction and speed of the approaching vehicles. Environment‐ or group‐related factors (e.g., time of year, distance to escape terrain, group size or type) did not affect mountain goat responses to ATVs. Because goat reactions were influenced by disturbance‐level factors, we propose mitigating measures regarding the use of ATVs in the wild to minimize the disturbance to mountain goats, and potentially other alpine ungulates. © 2012 The Wildlife Society.
Simulating density‐dependent relationships in south Texas northern bobwhite populations
Authors: DeMaso Stephen J. , Sands Joseph P. , Brennan Leonard A. , Hernández Fidel , Deyoung Randy W.
Published: December 2012

Density dependence influences northern bobwhite (Colinus virginianus) reproduction and overwinter mortality. However, the functional forms of these density‐dependent relationships or the factors that influence them during the annual life cycle events of this bird are not clear. We used a systems analysis approach with a compartment model based on difference equations (Δt = 3 months) for bobwhites in South Texas to simulate population behavior using 16 different functional forms of density‐dependent production and overwinter mortality. During the reproductive season, a weak linear density‐dependent relationship resulted in the longest population persistence (up to 100.0 yr), whereas a reverse‐sigmoid density‐dependent relationship had the worst population persistence (2.5–3.5 yr). Regarding overwinter mortality, a sigmoid or weak linear density‐dependent relationship and a weak linear or no density‐dependent reproduction relationship had the longest population persistence (87.5–100.0 yr). Weak linear density‐dependent reproduction with either sigmoid or weak linear overwinter mortality produced stable fall population trends. Our results indicated that density dependence may have a greater influence on overwinter survival of bobwhites than previously thought. Inclusion of density‐dependent functional relationships that represent both density‐dependent reproduction and overwinter mortality, were critical for our simulation model to function properly. Therefore, integrating density‐dependent relationships for both reproductive and overwinter periods of the annual cycle of bobwhite life history events is essential for conducting realistic bobwhite population simulation analyses that can be used to test different management scenarios in an integrated and interdisciplinary manner. © 2012 The Wildlife Society.
Assessing the drinking status of liver transplant patients with alcoholic liver disease
Authors: Allen John P. , Wurst Friedrich M. , Thon Natasha , Litten Raye Z.
Published: December 2012

The accurate assessment of drinking by patients with alcoholic liver disease is important both before and after liver transplantation. Unfortunately, self-reports by these individuals often underestimate their actual alcohol consumption. Several recently developed biochemical measures can provide additional information on a patient's use of alcohol. This article describes ethyl glucuronide, ethyl sulfate, phosphatidyl ethanol, and carbohydrate-deficient transferrin as biomarkers of drinking and summarizes research dealing with their application in patients with alcohol use disorders who are candidates for or recipients of liver transplantation. The article also offers suggestions for enhancing the reliability of self-report measures of drinking status. Liver Transpl 19:369–376, 2013. © 2013 AASLD.
Complete tumor encapsulation on magnetic resonance imaging: A potentially useful imaging biomarker for better survival in solitary large hepatocellular carcinoma
Authors: Lu David S. , Siripongsakun Surachate , Kyong Lee Jeong , Wei Sindy H. , Cheng Phillip M. , Sabounchi Saman , Lee Jong Seok , Raman Steven , Tong Myron J. , Busuttil Ronald W. , Sayre James
Published: December 2012

The aim of this study was to determine the prognostic value of complete tumor encapsulation as visualized on magnetic resonance imaging (MRI) in patients with a solitary large hepatocellular carcinoma (HCC) beyond the Milan criteria for liver transplantation (LT). Between December 2000 and March 2011, 57 patients who had a solitary HCC exceeding 5 cm in diameter at the time of initial MRI before any treatment were identified. MRI images of the patients were independently reviewed by 2 experienced readers for the presence of complete tumoral encapsulation. The medical records of the patients were reviewed for an outcome analysis. Thirty of the 57 patients had completely encapsulated HCC according to MRI. There was excellent interobserver agreement between the 2 readers for the assessment of complete encapsulation (κ=0.86). Overall survival was significantly longer for patients with completely encapsulated HCC versus patients with incompletely or nonencapsulated tumors (P<0.001), and this included a subanalysis of 33 patients who received locoregional treatment (LRT; P=0.04). The presence of complete encapsulation was a strong predictor for survival in these patients according to both univariate [hazard ratio (HR)=0.24, 95% confidence interval (CI)=0.12–0.52, P<0.001] and multivariate analyses (HR=0.25, 95% CI=0.07–0.85, P=0.03). The rates of down-staging (P<0.001) and eventual LT (P=0.02) after LRT were also significantly higher in the patients with completely encapsulated tumors. In conclusion, complete tumor encapsulation on MRI is a potentially useful predictor for favorable biology in patients with a solitary large HCC. This new imaging biomarker may have a role in treatment selection for patients whose tumors exceed the Milan criteria size limits.