bluuebunny/crossref_metadata_2025 huggingface dataset:
Benzophenone semicarbazone protection strategy for synthesis of aza‐glycine containing aza‐peptides
Authors: Bourguet Carine B. , Sabatino David , Lubell William D.
Published: October 2008

Aza‐glycine has been incorporated into peptide mimics as a tool for studying the active conformation and characterizing structure‐function relationships for activity. Side reactions, such as intramolecular cyclizations to form hydantoins and oxadiazalones, have, however, inhibited efforts to make activated aza‐Gly residues in solution using carbamate protection. Herein, we describe efficient incorporation of aza‐glycine into aza‐peptides using diphenyl hydrazone protection. Hydrazone acylation with p‐nitrobenzyl chloroformate provided the protected aza‐Gly activated ester, which was used to acylate a set of amino ester and amino acids to provide aza‐Gly‐Xaa aza‐dipeptide fragments for peptide synthesis. Removal of the hydrazone protection was performed under acidic conditions to provide the hydrochloride salt of the aza‐Gly residue for subsequent elongation of the aza‐peptide chain using standard coupling conditions. A proof of concept for the use of benzophenone protection has been established by the synthesis of an aza‐peptide analog of a potent activator of caspase 9 in cancer cells. © 2008 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 90: 824–831, 2008.

This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Lipopolysaccharide bound structures of the active fragments of fowlicidin‐1, a cathelicidin family of antimicrobial and antiendotoxic peptide from chicken, determined by transferred nuclear overhauser effect spectroscopy
Authors: Bhunia Anirban , Mohanram Harini , Bhattacharjya Surajit
Published: October 2008

Cathelicidins comprise a major family of host‐defense antimicrobial peptides in vertebrates. The C‐terminal part of the cathelicidins is bestowed with antimicrobial and lipopolysaccharide (LPS) neutralizing activities. In this work, we repot high resolution solution structures of two nontoxic active fragments, residues 1–16 or RG16 and residues 8–26 or LK19, of fowlicidin‐1, a cathelicidin family of peptide from chicken, as a complex with LPS using two‐dimensional transferred nuclear Overhauser effect (Tr‐NOE) spectroscopy. Both peptides are highly flexible and do not assume any preferred conformations in their free states. Upon complexation with endotoxin or LPS, peptides undergo structural transitions towards folded conformations. Structure calculations reveal that the LK19 peptide adopts a well defined helical structure with a bend at the middle. By contrast, the first seven amino acids of RG16 are found to be flexible followed by a helical conformation for the residues L8‐A15. In addition, a truncated version of LK19 encompassing residues A15‐K26 or AK12 displays an amphipathic helical structure in LPS. Saturation transfer difference (STD) NMR studies demonstrate that all peptides, RG16, LK19, and AK12, are in close proximity with LPS, whereby the aromatic residues showed the strongest STD effects. Fluorescence studies with fluorescein isothiocyanate (FITC) labeled LPS in the presence of full‐length fowlicidin‐1, LK19, RG16, and AK12 indicated that LPS‐neutralization property of these peptides may result from plausible dissociation of LPS aggregates. The helical structures of peptide fragments derived from fowlicidin‐1 in LPS could be utilized to develop nontoxic antiendotoxic compounds. © 2008 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 92: 9–22, 2009.

This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Loop‐length‐dependent SVM prediction of domain linkers for high‐throughput structural proteomics
Authors: Ebina Teppei , Toh Hiroyuki , Kuroda Yutaka
Published: October 2008

The prediction of structural domains in novel protein sequences is becoming of practical importance. One important area of application is the development of computer‐aided techniques for identifying, at a low cost, novel protein domain targets for large‐scale functional and structural proteomics. Here, we report a loop‐length‐dependent support vector machine (SVM) prediction of domain linkers, which are loops separating two structural domains. (DLP‐SVM is freely available at: http://www.tuat.ac.jp/∼domserv/cgi‐bin/DLP‐SVM.cgi.) We constructed three loop‐length‐dependent SVM predictors of domain linkers (SVM‐All, SVM‐Long and SVM‐Short), and also built SVM‐Joint, which combines the results of SVM‐Short and SVM‐Long into a single consolidated prediction. The performances of SVM‐Joint were, in most aspects, the highest, with a sensitivity of 59.7% and a specificity of 43.6%, which indicated that the specificity and the sensitivity were improved by over 2 and 3% respectively, when loop‐length‐dependent characteristics were taken into account. Furthermore, the sensitivity and specificity of SVM‐Joint were, respectively, 37.6 and 17.4% higher than those of a random guess, and also superior to those of previously reported domain linker predictors. These results indicate that SVMs can be used to predict domain linkers, and that loop‐length‐dependent characteristics are useful for improving SVM prediction performances. © 2008 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 92: 1–8, 2009.

This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Autonomic innervation of the developing heart: Origins and function
Authors: Hildreth Victoria , Anderson Robert H. , Henderson Deborah J.
Published: October 2008

Maintenance of homeostatic circulation in mammals and birds is reliant upon autonomic innervation of the heart. Neural branches of mixed cellular origin and function innervate the heart at the arterial and venous poles as it matures, eventually coupling autonomic output to the cardiac components, including the conduction system. The development of neural identity is controlled by specific networks of genes and growth factors, whereas functional properties are governed by the use of different neurotransmitters. In this review, we summarize briefly the anatomic arrangement of the vertebrate autonomic nervous system and describe, in detail, the innervation of the heart. We discuss the timing of cardiac innervation in the chick and mouse, emphasizing the relationship of the cardiac neural networks to the anatomical structures within the heart. We also discuss the variable contribution of the neural crest to vagal cardiac nerves, and summarize the main neurotransmitters secreted by the developing sympathetic and parasympathetic autonomic divisions. We provide an overview of the main growth factor and gene families involved in neural development, discussing how these factors may impact upon the development of cardiac abnormalities in congenital syndromes associated with autonomic dysfunction. Clin. Anat. 22:36–46, 2009. © 2008 Wiley‐Liss, Inc.
Identification of Additional Players in the Alternative Biosynthesis Pathway to Isovaleryl‐CoA in the Myxobacterium Myxococcus xanthus
Authors: Bode Helge B. , Ring Michael W. , Schwär Gertrud , Altmeyer Matthias O. , Kegler Carsten , Jose Ivy R. , Singer Mitchell , Müller Rolf
Published: October 2008

Isovaleryl‐CoA (IV‐CoA) is usually derived from the degradation of leucine by using the Bkd (branched‐chain keto acid dehydrogenase) complex. We have previously identified an alternative pathway for IV‐CoA formation in myxobacteria that branches from the well‐known mevalonate‐dependent isoprenoid biosynthesis pathway. We identified 3‐hydroxy‐3‐methylglutaryl‐CoA (HMG‐CoA) synthase (MvaS) to be involved in this pathway in Myxococcus xanthus, which is induced in mutants with impaired leucine degradation (e.g., bkd−) or during myxobacterial fruiting‐body formation. Here, we show that the proteins required for leucine degradation are also involved in the alternative IV‐CoA biosynthesis pathway through the efficient catalysis of the reverse reactions. Moreover, we conducted a global gene‐expression experiment and compared vegetative wild‐type cells with bkd mutants, and identified a five‐gene operon that is highly up‐regulated in bkd mutants and contains mvaS and other genes that are directly involved in the alternative pathway. Based on our experiments, we assigned roles to the genes required for the formation of IV‐CoA from HMG‐CoA. Additionally, several genes involved in outer‐membrane biosynthesis and a plethora of genes encoding regulatory proteins were decreased in expression levels in the bkd− mutant; this explains the complex phenotype of bkd mutants including a lack of adhesion in developmental submerse culture.
Structure and Charge Control in Metal–Organic Frameworks Based on the Tetrahedral Ligand Tetrakis(4‐tetrazolylphenyl)methane
Authors: Dincǎ Mircea , Dailly Anne , Long Jeffrey R.
Published: October 2008

Use of the tetrahedral ligand tetrakis(4‐tetrazolylphenyl)methane enabled isolation of two three‐dimensional metal–organic frameworks featuring 4,6‐ and 4,8‐connected nets related to the structures of garnet and fluorite with the formulae Mn6(ttpm)3⋅5 DMF⋅3 H2O (1) and Cu[(Cu4Cl)(ttpm)2]2⋅CuCl2⋅5 DMF⋅11 H2O (2) (H4ttpm=tetrakis(4‐tetrazolylphenyl)methane). The fluorite‐type solid 2 displays an unprecedented post‐synthetic transformation in which the negative charge of the framework is reduced by extraction of copper(II) chloride. Desolvation of this compound generates Cu4(ttpm)2⋅0.7 CuCl2 (2 d), a microporous material exhibiting a high surface area and significant hydrogen uptake.
Phosphorus‐Based Heteropentacenes: Efficiently Tunable Materials for Organic n‐Type Semiconductors
Authors: Dienes Yvonne , Eggenstein Matthias , Kárpáti Tamás , Sutherland Todd C. , Nyulászi László , Baumgartner Thomas
Published: October 2008

Benzo‐condensed dithieno[3,2‐b:2′,3′‐d]phospholes have been synthesized that allow convenient tuning of properties that are essential for application as semiconductor materials in organic field‐effect transistor (OFET) devices. The versatile reactivity of the trivalent phosphorus atom in these heteropentacenes provides access to a series of materials that show different photophysical properties, significantly different organization in the solid state, and distinctly different electrochemical properties that can be achieved by simple chemical modifications. The materials show strong photoluminescence in solution and in the solid state that depends on the electronic nature of the phosphorus center. Electrochemical studies revealed that the phosphorus atom intrinsically furnishes materials with n‐channel or ambipolar behavior, also depending on its electronic nature. The experimental data were verified by DFT quantum chemical calculations and suggest that the phosphorus‐based heteropentacenes could be excellent candidates for n‐channel OFET semiconductor materials.
β′‐Hydroxy‐α,β‐unsaturated ketones: A new pharmacophore for the design of anticancer drugs. Part 2.
Authors: León Leticia G. , Carballo Rubén M. , Vega‐Hernández María C. , Miranda Pedro O. , Martín Víctor S. , Padrón Juan I. , Padrón José M.
Published: October 2008

Novel antiproliferative β′‐acyloxy‐α,β‐unsaturated ketones were obtained by means of an iron(III)‐catalyzed multicomponent domino process (ABB′ 3CR). The most active derivatives displayed GI50 values in the range of 0.5–3.9 μM against a panel of representative human solid tumor cell lines: A2780, SW1573, HBL‐100, T‐47D and WiDr. Analysis of cells following 24 h exposure to these drugs showed cell cycle arrest in the S and G2/M phase, in a dose‐dependent manner. Our data indicate that the β′‐acyloxy‐α,β‐unsaturated ketones cause permanent damage to the cells and induce apoptosis.
Synthesis and Properties of a Mitochondrial Peripheral Benzodiazepine Receptor Conjugate
Authors: El Alaoui Abdessamad , Schmidt Frédéric , Sarr Marianne , Decaudin Didier , Florent Jean‐Claude , Johannes Ludger
Published: October 2008

Peripheral benzodiazepine receptors are potential targets for cancer therapeutics through the use of specific ligands such as the pro‐apoptotic benzodiazepine RO5‐4864. However, the poor water solubility of this compound has been a limitation to its application in vivo. Herein we describe an efficient synthesis for the conjugation, via a cleavable linker arm, of RO5‐4864 to a novel tumour‐delivery tool, the B‐subunit of Shiga toxin (STxB). The conjugate is water soluble and specifically targets cancer cells that overexpress the glycolipid Gb3, the cellular Shiga toxin receptor that is found on several human tumours. After internalisation via retrograde transport, the prodrug is cleaved inside cells to release the active principle. Delivery by STxB therefore increases the cytotoxic activity of RO5‐4864 and its tumour specificity.
Treatment of core‐binding‐factor in acute myelogenous leukemia with fludarabine, cytarabine, and granulocyte colony‐stimulating factor results in improved event‐free survival
Authors: Borthakur Gautam , Kantarjian Hagop , Wang Xuemei , Plunkett William K. , Gandhi Varsha V. , Faderl Stefan , Garcia‐Manero Guillermo , Ravandi Farhad , Pierce Sherry , Estey Elihu H.
Published: October 2008

BACKGROUND.

Acute myelogenous leukemia (AML) associated with core‐binding‐factor (CBF) abnormalities is the type of leukemia most responsive to cytarabine (ara‐C) therapy and is of relative favorable prognosis. In vitro and ex vivo observations suggest that increases in intracellular ara‐C levels influenced by administration of fludarabine and granulocyte colony‐stimulating factor (GCSF) increase the effect of ara‐C, prompting us to clinically evaluate the efficacy of such combinations.

METHODS.

We analyzed the event‐free survival of patients with newly diagnosed CBF AML treated with fludarabine and ara‐C (FA) (N = 45) or with FA and GCSF (FLAG) (N = 22) and compared results to patients treated with regimens consisting of idarubicin and ara‐C with or without GCSF (IA/IAG) (N = 47).

RESULTS.

After accounting for prognostic covariates other than treatment (including year in which treatment was administered), FA, and in particular FLAG, were associated with longer event‐free survival than IA/IAG.

CONCLUSIONS.

Thus, our data lends clinical credence to the observed modulation of ara‐C by fludarabine and GCSF. Cancer 2008. © 2008 American Cancer Society.
Intrinsic connections of the macaque monkey hippocampal formation: I. Dentate gyrus
Authors: Kondo Hideki , Lavenex Pierre , Amaral David G.
Published: October 2008

We have carried out a detailed analysis of the intrinsic connectivity of the Macaca fascicularis monkey hippocampal formation. Here we report findings on the topographical organization of the major connections of the dentate gyrus. Localized anterograde tracer injections were made at various rostrocaudal levels of the dentate gyrus, and we investigated the three‐dimensional organization of the mossy fibers, the associational projection, and the local projections. The mossy fibers travel throughout the transverse extent of CA3 at the level of the cells of origin. Once the mossy fibers reach the distal portion of CA3, they change course and travel for 3–5 mm rostrally. The associational projection, originating from cells in the polymorphic layer, terminates in the inner one‐third of the molecular layer. The associational projection, though modest at the level of origin, travels both rostrally and caudally from the injection site for as much as 80% of the rostrocaudal extent of the dentate gyrus. The caudally directed projection is typically more extensive and denser than the rostrally directed projection. Cells in the polymorphic layer originate local projections that terminate in the outer two‐thirds of the molecular layer. These projections are densest at the level of the cells of origin but also extend several millimeters rostrocaudally. Overall, the topographic organization of the intrinsic connections of the monkey dentate gyrus is largely similar to that of the rat. Such extensive longitudinal connections have the potential for integrating information across much of the rostrocaudal extent of the dentate gyrus. J. Comp. Neurol. 511:497–520, 2008. © 2008 Wiley‐Liss, Inc.
An Investigation of Protonation Sites and Conformations of Protonated Amino Acids by IRMPD Spectroscopy
Authors: Wu Ronghu , McMahon Terry B.
Published: October 2008

The protonation sites and structures of a series of protonated amino acids (Gly, Ala, Pro, Phe, Lys and Ser) are investigated by means of infrared multiple‐photon dissociation (IRMPD) spectroscopy and electronic‐structure calculations. The IRMPD spectra of the protonated species are recorded using the combination of a free‐electron laser (FEL) and an electrospray‐ion‐trap mass spectrometer. The structures of different possible isomers of these protonated species are optimized at the B3LYP/6‐311+G(d, p) level of theory and the IR spectra calculated using the same computational method. For every amino acid studied herein, the current results indicate that a proton is bound to the α‐amino nitrogen, except for lysine, in which the protonation site is the amino nitrogen in the side chain. According to the calculated and experimental IRMPD results, the structures of the protonated amino acids may be assigned unambiguously. For Gly, Ala, and Pro, in each of the most stable isomers the protonated amino group forms an intramolecular hydrogen bond with the adjacent carbonyl oxygen. In the case of Gly, the isomer containing a proton bound to the carbonyl oxygen is theoretically possible. However, it does not exist under the experimental conditions because it has a significantly higher energy (i.e. 26.6 kcal mol−1) relative to the most stable isomer. For Ser and Phe, the protonated amino group forms two intramolecular hydrogen bonds with both the adjacent carbonyl oxygen and the side‐chain group in each of the most stable isomers. In protonated lysine, the protonated amino group in the side chain forms two hydrogen bonds with the α‐amino nitrogen and the carbonyl oxygen, which is a cyclic structure. Interestingly, for protonated lysine the zwitterionic structure is a local minimum energy isomer, but the experimental spectrum indicates that it does not exist under the experimental conditions. This is consistent with the fact that the zwitterionic isomer is 9.2 kcal mol−1 higher in free energy at 298 K than the most stable isomer. The carbonyl stretching vibration in the range of 1760–1800 cm−1 is especially sensitive to the structural change. In addition, IRMPD mechanisms for the protonated amino acids are also investigated.
Efficient Synthesis of Dimethyl Ether over HZSM‐5 Supported on Medium‐Surface‐Area β‐SiC Foam
Authors: Ivanova Svetlana , Vanhaecke Estelle , Louis Benoit , Libs Suzanne , Ledoux Marc‐Jacques , Rigolet Sévérine , Marichal Claire , Pham Charlotte , Luck Francis , Pham‐Huu Cuong
Published: October 2008

In this study, we aimed to produce a highly selective and stable catalyst for the production of dimethyl ether by methanol dehydration. The activities were compared of different active phases of the employed system, zeolite HZSM‐5 or γ‐alumina, supported on silicon carbide as foam, and it was found that the supported zeolite catalysts are more active than and as selective as the alumina‐based catalysts. The as‐prepared zeolite/SiC composites reveal good stability in long‐term tests in the presence or absence of steam. The high stability is attributed to the presence of highly dispersed micrometer‐sized zeolite particles, which make the active sites more accessible to the reactants and promote the quick transfer of the desired product, dimethyl ether, out of the catalyst bed, minimizing deactivation of the catalyst.
Polysialic acid regulates the clustering, migration, and neuronal differentiation of progenitor cells in the adult hippocampus
Authors: Burgess Alison , Wainwright Steven R. , Shihabuddin Lamya S. , Rutishauser Urs , Seki Tatsunori , Aubert Isabelle
Published: October 2008

Newborn cells of the adult dentate gyrus in the hippocampus are characterized by their abundant expression of polysialic acid (PSA), a carbohydrate attached to the neural cell adhesion molecule (NCAM). PSA+ newborn cells of the dentate gyrus form clusters with proliferating neural progenitor cells, migrate away from these clusters, and terminally differentiate. To identify the roles of PSA in the development of adult progenitors of the dentate gyrus, we injected endoneuraminidase N (endoN) into the hippocampus of adult rats to specifically cleave PSA from NCAM. Two days later, we administered the mitotic marker, 5‐bromo‐2′‐deoxyuridine (BrdU). Three days after BrdU injection, BrdU+ cells were found inside and outside the clusters of newborn cells. In endoN‐treated animals, the total number of BrdU+ cells was not changed but significantly more BrdU+ cells were present within clusters, suggesting that PSA normally facilitates the migration of progenitors away from the clusters. Seven days post‐BrdU injection, endoN‐treated animals had significantly more BrdU+ cells which were also positive for the mature neuronal nuclear marker NeuN compared with controls, indicating that the loss of PSA from progenitor cells increases neuronal differentiation. This report is the first demonstration that PSA is involved in controlling the spatio‐temporal neuronal maturation of adult hippocampal progenitors in the normal brain. In vitro, the removal of PSA from adult‐derived neural progenitors significantly enhanced neuronal differentiation, strengthening our in vivo findings and indicating that PSA removal on isolated progenitor cells, apart from a complex in vivo environment, induces neuronal maturation. © 2008 Wiley Periodicals, Inc. Develop Neurobiol, 2008.
1,2‐Diboracyclopentanes without Strong Donor Substituents: Synthesis, Reactions, and Computational Analysis
Authors: Präsang Carsten , Sahin Yüksel , Hofmann Matthias , Geiseler Gertraud , Massa Werner , Berndt Armin
Published: October 2008

The 1,2‐diduryl‐1,2‐diboracyclopentane 1a was obtained in good yield from the recently described 1,2‐dichloro‐1,2‐diboracyclopentane 1c. Thermolysis of 1a led to a mixture of compounds from which degradation products 5a and 6a as well as isomer 7a could be isolated. Sterically less‐hindered 1b spontaneously transformed into its isomer 7b. Attempts to prepare 4a by deprotonation of 1a led to ring enlarged anions 8a and 8b. The structures of all new compounds were definitively proven by X‐ray structural analyses. Computations at the B3LYP/6‐311+G** level of theory suggest that derivatives of the kinetically preferred isomer 2u of 1u are the key intermediates on the route to 5a and 6a, which are the main products of the thermolysis of 1a. In contrast to expectation, derivatives of thermodynamically preferred isomer 3u could neither be observed nor shown by computations to be involved in the formation of the products obtained from 1a and 1b.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Synthetic Studies towards Guaianolide Sesquiterpene Lactones
Authors: Reboul Isabelle , Boddaert Thomas , Coquerel Yoann , Rodriguez Jean
Published: October 2008

A promising synthetic route towards bioactive guaianolide sesquiterpene lactones is presented. The strategy is based on a recently invented multicomponent reaction (MARDi cascade) and subsequent highly chemoselective and domino transformations for the expeditious stereoselective preparation of the tricyclic core of the natural products. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Effect of particle density and inflow concentration of suspended sediment on bedload transport in rill flow
Authors: Nord Guillaume , Esteves, Michel , Lapetite Jean‐Marc , Hauet Alexandre
Published: October 2008

Laboratory flume experiments were carried out to evaluate the effect of particle density on bedload transport of sand‐sized particles and the effect of a suspended load of clay particles (kaolinite) on bedload transport of sand‐sized particles in rill flow conditions. Three materials in the range 400–600 µm were selected to simulate bedload transport of primary particles and aggregates: sand (2650 kg/m3), crushed brick (2450 kg/m3) and anthracite (1300–1700 kg/m3). In the two first experiments, two different methods were applied to determine bedload transport capacity of coarse particles for various conditions of flow discharge (from 2 to 15 L/min) and slope (2.2, 3 and 4%). In the third experiment, clear water was replaced with kaolinite–water mixture and bedload transport capacity of crushed brick particles was determined for a 4% slope and different concentrations of kaolinite (0, 7, 41 and 84 g/L). The results showed that bedload transport increased significantly with the decrease in particle density but the effect of particle density on transport rates was much less important than flow discharge. Velocity measurements of clear flow, flow mixed with coarse particles and coarse particles confirmed the existence of a differentiation between suspended load and bedload. In these experimental conditions, suspended load of kaolinite did not affect bedload rates of crushed brick particles. Three transport capacity formulae were tested against observed bedload rates. A calibration of the Foster formula revealed that the shear stress exponent should be greater than 1.5. The Low and the Govers unit stream power (USP) equations were then evaluated. The Low equation was preferred for the prediction of bedload rates of primary particles but it was not recommended in the case of aggregates of low density because of the limited experimental conditions applied to derive this equation. Copyright © 2008 John Wiley & Sons, Ltd.
Alterations in hepatic glucose and energy metabolism as a result of calorie and carbohydrate restriction
Authors: Browning Jeffrey D. , Weis Brian , Davis Jeannie , Satapati Santhosh , Merritt Matthew , Malloy Craig R. , Burgess Shawn C.
Published: October 2008

Carbohydrate restriction is a common weight-loss approach that modifies hepatic metabolism by increasing gluconeogenesis (GNG) and ketosis. Because little is known about the effect of carbohydrate restriction on the origin of gluconeogenic precursors (GNG from glycerol [GNGglycerol] and GNG from lactate/amino acids [GNGphosphoenolpyruvate {PEP}]) or its consequence to hepatic energy homeostasis, we studied these parameters in a group of overweight/obese subjects undergoing weight-loss via dietary restriction. We used 2H and 13C tracers and nuclear magnetic resonance spectroscopy to measure the sources of hepatic glucose and tricarboxylic acid (TCA) cycle flux in weight-stable subjects (n = 7) and subjects following carbohydrate restriction (n = 7) or calorie restriction (n = 7). The majority of hepatic glucose production in carbohydrate restricted subjects came from GNGPEP. The contribution of glycerol to GNG was similar in all groups despite evidence of increased fat oxidation in carbohydrate restricted subjects. A strong correlation between TCA cycle flux and GNGPEP was found, though the reliance on TCA cycle energy production for GNG was attenuated in subjects undergoing carbohydrate restriction. Together, these data imply that the TCA cycle is the energetic patron of GNG. However, the relationship between these two pathways is modified by carbohydrate restriction, suggesting an increased reliance of the hepatocyte on energy generated outside of the TCA cycle when GNGPEP is maximal.

Conclusion:

Carbohydrate restriction modifies hepatic GNG by increasing reliance on substrates like lactate or amino acids but not glycerol. This modification is associated with a reorganization of hepatic energy metabolism suggestive of enhanced hepatic β-oxidation. (Hepatology 2008;48:1487–1496.)
High incidence of hepatitis C virus reinfection in a cohort of injecting drug users
Authors: Aitken Campbell Kynoch , Lewis Jennifer , Tracy Samantha Lilly , Spelman Timothy , Bowden David Scott , Bharadwaj Mandvi , Drummer Heidi , Hellard Margaret
Published: October 2008

An estimated 170 million people worldwide carry the hepatitis C virus (HCV), and in more developed countries the prevalence and incidence of HCV is particularly high among injecting drug users (IDUs). Spontaneous clearance of HCV infection and reinfection is well recognized but the level of protection against further infection conferred by HCV infection and clearance remains uncertain. We conducted a prospective study of HCV infection in IDUs recruited in Melbourne, Australia, using a much shorter median testing interval than in previous studies. Incidences of naive infection and reinfection were calculated by the person-year method and Cox proportional hazards regression used to adjust for covariates. A significantly higher HCV incidence rate was measured in previously infected IDUs (46.8% per year) compared with HCV-naive IDUs (15.5% per year). The hazard ratio for previously infected IDUs compared to HCV-naive IDUs, after adjustment for time-dependent covariates, was 2.54 (95% confidence interval, 1.11–5.78,

P

> |z| < 0.05). Viral persistence after reinfection appeared similar to that following naive infection.

Conclusion:

Our data suggest that HCV infection in IDUs is more likely following prior infection and clearance than in HCV-naive individuals, implying no increased immunity against further infection. This result has important implications for the future development of an HCV vaccine. (Hepatology 2008;48:1746-1752.)
Rat hepatocyte spheroids formed by rocked technique maintain differentiated hepatocyte gene expression and function #
Authors: Brophy Colleen M. , Luebke-Wheeler Jennifer L. , Amiot Bruce P. , Khan Harris , Remmel Rory P. , Rinaldo Piero , Nyberg Scott L.
Published: October 2008

The culture of primary hepatocytes as spheroids creates an efficient three-dimensional tissue construct for hepatic studies in vitro. Spheroids possess structural polarity and functional bile canaliculi with normal differentiated function. Thus, hepatocyte spheroids have been proposed as the cell source in a variety of diagnostic, discovery, and therapeutic applications, such as a bioartificial liver. Using a novel rocking technique to induce spheroid formation, kinetics of spheroid formation, cell-cell adhesion, gene expression, and biochemical activities of rat hepatocyte spheroids were tested over 14 days of culture. Evidence was provided that the formation of spheroids occurred faster and with fewer nonadherent hepatocytes in rocked suspension culture compared to a traditional rotational system. Hepatocyte spheroids in rocked culture showed stable expression of more than 80% of 242 liver-related genes including those of albumin synthesis, urea cycle, phase I and II metabolic enzymes, and clotting factors. Biochemical activity of rocked spheroid hepatocytes was superior to monolayer culture of hepatocytes on tissue culture plastic and collagen. Conclusion: Spheroid formation by rocker technique was more rapid and more efficient than by rotational technique. Rocker-formed spheroids appear suitable for application in a bioartificial liver or as an in vitro liver tissue construct. (Hepatology 2009.)
Human inhibitor of growth 1 inhibits hepatoma cell growth and influences p53 stability in a variant-dependent manner #
Authors: Zhu Zhi , Luo Zhigang , Li Yongmei , Ni Canrong , Li Honghua , Zhu Minghua
Published: October 2008

Inhibitor of growth 1 (ING1) is a type II tumor suppressor that affects cell function by altering chromatin structure and regulating transcription. Recently, three ING1 splice variants have been cloned, but their roles in apoptosis and p53 regulation in human hepatocellular carcinoma (HCC) have not been fully elucidated. The present study found that ING1, in a variant-dependent manner, inhibited hepatoma cell proliferation and colony formation, induced apoptosis and cell cycle arrest at G0/G1 phase, and postponed tumor formation in nude mice. Expression of p33ING1b and p24ING1c variants, but not p47ING1a, was markedly reduced in HCC samples. Reverse transcription polymerase chain reaction and western blotting analysis revealed that ectopic overexpression of p33ING1b or p24ING1c variant increased the expression of p53 downstream genes such as p21waf1 and bax, and repressed bcl-2 expression (P < 0.01), whereas p47ING1a inactivated p21waf1 promoter (P < 0.01). Furthermore, we found that p33ING1b and p24ING1c repressed Mdm2 expression (P < 0.01) and competed with Mdm2 for binding to p53. Interestingly, p33ING1band p24ING1c did not directly bind to Mdm2 protein but strongly increased p14arf expression (P < 0.01) and interacted with p14arf protein to stimulate p53. Moreover, we found that ectopic overexpression of p33ING1b or p24ING1c significantly induced p53 protein acetylation at Lys-373/Lys-382 residue, but did not alter the phosphorylation status of p53. Conclusion: ING1 variants p33ING1b and p24ING1c may modulate p53 activity and subsequently inhibit hepatoma cell growth by at least two possible mechanisms: interacting with Mdm2 and p14arf to stabilize and activate p53, or increasing p53 acetylation. (Hepatology 2009.)
Predicting in-hospital mortality in patients with cirrhosis: Results differ across risk adjustment methods #
Authors: Myers Robert P. , Quan Hude , Hubbard James N. , Shaheen Abdel Aziz M. , Kaplan Gilaad G.
Published: October 2008

Risk-adjusted health outcomes are often used to measure the quality of hospital care, yet the optimal approach in patients with liver disease is unclear. We sought to determine whether assessments of illness severity, defined as risk for in-hospital mortality, vary across methods in patients with cirrhosis. We identified 258,731 patients with cirrhosis hospitalized in the Nationwide Inpatient Sample between 2002 and 2005. The performance of four common risk adjustment methods (the Charlson/Deyo and Elixhauser comorbidity algorithms, Disease Staging, and All Patient Refined Diagnosis Related Groups [APR-DRGs]) for predicting in-hospital mortality was determined using the c-statistic. Subgroup analyses were conducted according to a primary versus secondary diagnosis of cirrhosis and in homogeneous patient subgroups (hepatic encephalopathy, hepatocellular carcinoma, congestive heart failure, pneumonia, hip fracture, and cholelithiasis). Patients were also ranked according to the probability of death as predicted by each method, and rankings were compared across methods. Predicted mortality according to the risk adjustment methods agreed for only 55%–67% of patients. Similarly, performance of the methods for predicting in-hospital mortality varied significantly. Overall, the c-statistics (95% confidence interval) for the Charlson/Deyo and Elixhauser algorithms, Disease Staging, and APR-DRGs were 0.683 (0.680–0.687), 0.749 (0.746–0.752), 0.832 (0.829–0.834), and 0.875 (0.873–0.878), respectively. Results were robust across diagnostic subgroups, but performance was lower in patients with a primary versus secondary diagnosis of cirrhosis. Conclusion: Mortality analyses in patients with cirrhosis require sensitivity to the method of risk adjustment. Because different methods often produce divergent severity rankings, analyses of provider-specific outcomes may be biased depending on the method used. (Hepatology 2008.)
Determinants of relapse after a short (12 weeks) course of antiviral therapy and re-treatment efficacy of a prolonged course in patients with chronic hepatitis C virus genotype 2 or 3 infection #
Authors: Mangia Alessandra , Minerva Nicola , Bacca Donato , Cozzolongo Raffaele , Agostinacchio Ernesto , Sogari Fernando , Scotto Gaetano , Vinelli Francesco , Ricci Giovanni Luciano , Romano Mario , Carretta Vito , Petruzzellis Daniela , Andriulli Angelo
Published: October 2008

In hepatitis C virus (HCV) genotypes 2 and 3 patients, the high rate of relapse after 12 to 16 weeks of antiviral therapy is the main concern for shortening treatment duration. This study was undertaken to delineate predictors of relapse after short treatment in patients with undetectable HCV RNA at treatment week 4 (RVR), and to report in RVR patients with relapse the sustained virological response (SVR) after a second 24-week course of therapy. RVR patients received pegylated interferon (Peg-IFN) alfa-2b (1.5 μg/kg) and ribavirin (1000-1200 mg/day) for 12 weeks; those who relapsed were re-treated with the same drug doses but for the extended standard duration of 24 weeks. Logistic regression analysis was applied to delineate predictors of relapse by using age, sex, route of transmission, body mass index (BMI), serum alanine aminotransferase (ALT), HCV genotypes, serum HCV RNA levels, and platelet counts as covariates. Of 718 patients with genotypes 2 and 3 who were started on therapy, 496 (69.1%) had undetectable HCV RNA at week 4. Of them, 409 patients (82.5%, CI 79.1-85.8) attained SVR, and 67 (14.1%, CI 10.4-16.5) relapsed. At regression analysis, only platelet count less than 140,000 mm3 [odds ratio, 2.51; confidence interval (CI), 1.49-4.20] and BMI 30 or higher (odds ratio, 1.7; CI, 1.03-2.70) were independently associated with relapse. Forty-three of 67 patients with relapse agreed to be re-treated, and an SVR was achieved in 30 (70.0%) of them. Conclusion: We recommend 12 weeks course of therapy for patients with undetectable HCV RNA at treatment week 4, providing they present with no advanced fibrosis and low BMI. (Hepatology 2008.)
The interleukin-17 pathway is involved in human alcoholic liver disease # †
Authors: Lemmers Arnaud , Moreno Christophe , Gustot Thierry , Maréchal Raphaël , Degré Delphine , Demetter Pieter , de Nadai Patricia , Geerts Albert , Quertinmont Eric , Vercruysse Vincent , Le Moine Olivier , Devière Jacques
Published: October 2008

Immune dysregulations in alcoholic liver diseases are still unclear, especially regarding alcoholic hepatitis inflammatory burst. Interleukin-17 (IL-17) is known to enhance neutrophil recruitment. We studied the IL-17 pathway in alcoholic cirrhosis and alcoholic hepatitis. Patients with alcoholic liver disease were compared with patients with chronic hepatitis C virus (HCV) infection or autoimmune liver disease and with healthy controls. IL-17 plasma levels and peripheral blood mononuclear cell secretion were assessed by enzyme-linked immunosorbent assay (ELISA) and T cell phenotype by flow cytometry. IL-17 staining and co-staining with CD3 and myeloperoxidase were performed on liver biopsy specimens. IL-17 receptor expression was studied on liver biopsies and in human hepatic stellate cells as well as their response to recombinant IL-17 by chemotaxis assays. IL-17 plasma levels were dramatically increased in alcoholic liver disease patients. Peripheral blood mononuclear cells of patients with alcoholic liver disease produced higher amounts of IL-17, and their CD4+ T lymphocytes disclosed an IL-17–secreting phenotype. In the liver, IL-17–secreting cells contributed to inflammatory infiltrates in alcoholic cirrhosis, and alcoholic hepatitis foci disclosed many IL-17+ cells, including T lymphocytes and neutrophils. In alcoholic liver disease, liver IL-17+ cells infiltrates correlated to model for end-stage liver disease score, and in alcoholic hepatitis to modified discriminant function. IL-17 receptor was expressed in alcoholic liver disease by hepatic stellate cells, and these cells recruited neutrophils after IL-17 stimulation in a dose-dependent manner through IL-8 and growth related oncogen α (GRO-α) secretion in vitro. Conclusion: Human alcoholic liver disease is characterized by the activation of the IL-17 pathway. In alcoholic hepatitis, liver infiltration with IL-17–secreting cell infiltrates is a key feature that might contribute to liver neutrophil recruitment. (Clinical trials number NCT00610597). (Hepatology 2009;49:646–657.)
Numerical simulation of vortex structures and heat transfer behind a hill in a laminar boundary layer
Authors: Yanaoka Hideki , Inamura Takao , Suenaga Yosuke , Kobayashi Yasuo
Published: October 2008

The present study examines a three‐dimensional numerical simulation of vortex structures and heat transfer behind a hill mounted in a laminar boundary layer. A vortex pair is formed symmetrically in the separation bubble behind the hill, and a hairpin vortex is periodically shed in the wake. The hairpin vortex moves downstream with time, and the gradient of the head of the hairpin vortex increases. Further downstream, the hairpin vortex is deformed to an Ω‐shaped structure. In the growth process of the hairpin vortex, horn‐shaped secondary vortices grow near the wall. The dissipation rate of the temperature fluctuation around the hairpin vortex increases because the heated fluid near the wall is removed to the free stream by Q2 ejection. Heat transfer increases due to the legs of the hairpin vortex and secondary vortices. These vortices generate high turbulence in the flow field and also contribute to an increase in Reynolds shear stress and turbulent heat flux. © 2008 Wiley Periodicals, Inc. Heat Trans Asian Res, 37(7): 398–411, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.20217
Condensate drop movement in Marangoni condensation by applying bulk temperature gradient on heat transfer surface
Authors: Utaka Yoshio , Kamiyama Tomoki
Published: October 2008

The spontaneous movement of condensate drops by application of a bulk temperature gradient on the heat transfer surface in Marangoni condensation was investigated, with consideration for applications to heat transfer devices. In the Marangoni condensation process, the removal of condensate on the heat transfer surface is important to maintain good heat transfer. A heat transfer device, in which the liquid movement occurs without external forces such as gravity and vapor shear force, may be useful in various applications. As a result of experiments using a water–ethanol vapor mixture, the movement of droplets from the low‐temperature side to high‐temperature side could be observed on a horizontally arranged heat transfer surface. The relation between the velocity of drop movement and the gradient of surface tension was studied for different concentrations. Furthermore, the effect of inclination of the condensing surface was examined. © 2008 Wiley Periodicals, Inc. Heat Trans Asian Res, 37(7): 387–397, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.20218
Flood simulation using the gauge‐adjusted radar rainfall and physics‐based distributed hydrologic model
Authors: Sik Kim Byung , Kyung Kim Bo , Soo Kim Hung
Published: October 2008

This paper reports the results of an investigation into flood simulation by areal rainfall estimated from the combination of gauged and radar rainfalls and a rainfall–runoff model on the Anseong‐cheon basin in the southern part of Korea. The spatial and temporal characteristics and behaviour of rainfall are analysed using various approaches combining radar and rain gauges: (1) using kriging of the rain gauge alone; (2) using radar data alone; (3) using mean field bias (MFB) of both radar and rain gauges; and (4) using conditional merging technique (CM) of both radar and rain gauges. To evaluate these methods, statistics and hyetograph for rain gauges and radar rainfalls were compared using hourly radar rainfall data from the Imjin‐river, Gangwha, rainfall radar site, Korea. Then, in order to evaluate the performance of flood estimates using different rainfall estimation methods, rainfall–runoff simulation was conducted using the physics‐based distributed hydrologic model, Vflo™. The flood runoff hydrograph was used to compare the calculated hydrographs with the observed one. Results show that the rainfall field estimated by CM methods improved flood estimates, because it optimally combines rainfall fields representing actual spatial and temporal characteristics of rainfall. Copyright © 2008 John Wiley & Sons, Ltd.
Social differences in breast cancer survival in relation to patient management within a National Health Care System (Sweden)
Authors: Eaker Sonja , Halmin Märit , Bellocco Rino , Bergkvist Leif , Ahlgren Johan , Holmberg Lars , Lambe Mats
Published: October 2008

Epidemiologic studies have shown that cancer survival is poorer in low compared with high socioeconomic groups. We investigated whether these differences were associated with disparities in tumour characteristics and management. This cohort study was based on 9,908 women aged 20–79 years at diagnosis with primary breast cancer identified in a Swedish population‐based clinical register. Information on socioeconomic standing was obtained from a social database. The 5‐year cause‐specific survival (CSS) and mortality hazard ratios (HR) were estimated by Cox proportional hazard models to assess differences in survival between socioeconomic groups while adjusting for diagnostic intensity, tumour characteristics and treatment. Following adjustment for age, year and stage at diagnosis, the risk of dying of breast cancer was 35% lower among women with high education compared with that of low education (HR = 0.65, 95% CI 0.53–0.80). When compared with women with high education, a lower percentage of women with low education had been investigated for proliferation (84 vs. 76%) or hormone receptor status (89 vs. 81%), had tumours ≤20 mm (68 vs. 64%), were treated at a main hospital (75 vs. 68%) and had received radiation treatment (80 vs. 67%) or chemotherapy (31 vs. 18%). However, these proportional differences could not explain the observed social gradient in survival. To minimize social differences in breast cancer survival, further research should address not only factors leading to inequities in management but also focus on patient factors such as health awareness, comorbidity burden and compliance to adjuvant treatment. © 2008 Wiley‐Liss, Inc.
Breast cancer incidence and mortality in a Caribbean population: Comparisons with African‐Americans
Authors: Hennis Anselm J. , Hambleton Ian R. , Wu Suh‐Yuh , Leske Maria Cristina , Nemesure Barbara ,   on behalf of the Barbados National Cancer Study Group
Published: October 2008

We describe breast cancer incidence and mortality in the predominantly African‐origin population of Barbados, which shares an ancestral origin with African‐Americans. Age‐standardized incidence rates were calculated from histologically confirmed breast cancer cases identified during a 45‐month period (July 2002–March 2006). Mortality rates were estimated from death registrations over 10‐years starting January 1995. There were 396 incident cases of breast cancer for an incidence rate of 78.1 (95% confidence interval (CI) 70.5–86.3), standardized to the US population. Breast cancer incidence in African‐Americans between 2000 and 2004 was 143.7 (142.0–145.5) per 100,000. Incidence peaked at 226.6 (174.5–289.4) per 100,000 among Barbadian women aged 50–54 years, and declined thereafter, a pattern in marked contrast to trends in African‐American women, whose rates continued to increase to a peak of 483.5 per 100,000 in those aged 75–79 years. Incidence rate ratios comparing Barbadian and African‐American women showed no statistically significant differences among women aged ≥ 55 years (p ≤ 0.001 at all older ages). The age‐standardized mortality rate in Barbados was 32.9 (29.9–36.0) per 100,000; similar to reported US rates. The pattern of diverging breast cancer incidence between Barbadian and African‐American women may suggest a greater contribution from genetic factors in younger women, and from environmental factors in older women. Studies in intermediate risk populations, such as Barbados, may assist the understanding of racial disparities in breast cancer. © 2008 Wiley‐Liss, Inc.