bluuebunny/crossref_metadata_2025 huggingface dataset:
State‐dependent hemispheric specialization in the songbird brain
Authors: George Isabelle , Cousillas Hugo , Richard Jean‐Pierre , Hausberger Martine
Published: May 2005

Lateralization of brain functions is a widespread phenomenon in vertebrates. With the well‐known lateralization in the processing of human speech and the parallels that exist between birdsong and language, songbirds are interesting for addressing such questions. In the present study, we investigated the central processing of communicative and artificial sounds in starlings, in an integrative part of the song system: the HVC. Neuronal responses to acoustic stimuli were systematically recorded in both hemispheres while the birds were awake, and then anesthetized, allowing quantitative comparisons of the responses obtained in each situation. The total proportion of responsive sites in the HVC of the left and right hemispheres of all birds revealed a significant predominance of the HVC of the right hemisphere when the birds were awake, whereas a high interindividual variability appeared when the birds were anesthetized. When neuronal responses as a whole were further examined, the responses to each type of stimulus appeared to be nonrandomly distributed over the different situations, and some specialization may appear. The results suggest a complex and state‐dependent hemispheric specialization toward behaviorally relevant classes of stimuli. In awake birds, the HVC of the left hemisphere may be more involved in the processing of songs that are used in individual recognition at distance, whereas the HVC of the right hemisphere may deal with long and complex sequences of a song that is involved in short‐distance communication, especially between males and females. With birds under anesthesia, this pattern is strongly modified. J. Comp. Neurol. 487:48–60, 2005. © 2005 Wiley‐Liss, Inc.
Cell cycle kinetic dysregulation in HIV‐infected normal lymphocytes
Authors: Asmuth David M. , Wang Nan , Lu Ying , Li Xiao‐Dong , Reece Lisa , Terry Nicholas H. A. , Pollard Richard B. , Nokta Mostafa , Leary James F. , White R. Allen
Published: May 2005

Background

Viruses alter cellular gene transcription and protein binding at many steps critical for cell cycle regulation to optimize the milieu for productive infection. Reasoning that virus–host cell interactions would result in perturbations of cell cycle kinetics, measurement of the duration of the phases of the cell cycle in normal T lymphocytes infected with human immunodeficiency virus (HIV) was undertaken.

Methods

Flow cytometric measurement of bromodeoxyuridine‐labeled and DNA content‐stained cells at multiple points through the cell cycle allowed estimation of the fraction of cells in each phase, the potential doubling‐time, and the durations of S and G2/M phases. Separate analysis of the HIV+and HIV−populations within the infected cultures was performed based on intracellular, anti‐HIV core p24 antibody labeling. A novel mathematical model, which accounted for cell loss, was developed to estimate cell cycle phases.

Results

(a) S phase was prolonged in the HIV‐1SF2–infected cells compared with control. (b) This delay in S phase was due to delay in the population of cells not expressing HIV‐1 antigens (p24 negative). (c) Accumulation of cells in G2/M phase was confirmed in HIV‐1–infected cultures and was proportional to the level of infection as measured by p24 fluorescent intensity. However, all mock and HIV‐1–infected populations predicted to proceed through cell division demonstrated similar G2/M‐phase durations. (c) Potential doubling times were longer in the infected cultures; in contrast, the p24+subpopulations accounted for this delay. This suggests an isolated delay in the G0/G1phase for that population of cells.

Conclusions

Multiple phases of host cell cycle durations were affected by HIV‐1SF2infection in this in vitro model, suggesting novel HIV‐1 pathogenesis mechanisms. Prolonged S‐phase durations in HIV‐1 infected/p24−and G0/G1‐phase durations in HIV‐1 infected/p24+subpopulations require further study to identify mechanistic pathways. © 2005 Wiley‐Liss, Inc.
New method to detect histone acetylation levels by flow cytometry
Authors: Ronzoni Simona , Faretta Mario , Ballarini Marco , Pelicci PierGiuseppe , Minucci Saverio
Published: May 2005

Background

Reversible histone acetylation affects chromatin structural organization, thus regulating gene expression and other nuclear events. Levels of histone acetylation are tightly modulated in normal cells, and alterations of their regulating mechanisms have been shown to be involved in tumorigenesis.

Methods

We developed a new flow cytometric technique for detection of histone acetylation, based on a specific monoclonal antibody that recognizes acetylated histone tails. Bivariate analysis for histone acetylation levels and DNA were performed to study modulation of chromatin organization during the cell cycle and after induction of histone hyperacetylation by the histone deacetylase (HDAC) inhibitor trichostatin A (TSA). Histone acetylation and transcription levels were monitored during differentiation induced by retinoic acid alone or in combination with TSA. Blood samples from patients were analyzed with the described protocol to monitor the effects of HDAC inhibitors in vivo and validate the developed protocol for clinical usage.

Results

Flow cytometric detection of acetylation status can successfully detect modifications induced by HDAC inhibitor treatment in vivo as demonstrated by analysis of various blood samples from patients treated with valproic acid. Changes in acetylation levels during the cell cycle demonstrated a reproducible increase in histone acetylation during the replication phase that was subsequently decreased at the G2M entrance, thus paralleling the behavior of DNA replication and transcriptional activity.

Conclusions

Multiparameter analysis of histone acetylation and expression of molecular markers, DNA ploidy, and/or cell cycle kinetics can provide a quick and statistically reliable tool for the diagnosis and evaluation of treatment efficacy in clinical trials using HDAC inhibitors. © 2005 Wiley‐Liss, Inc.
A Pulse Radiolysis Study of Catalytic Superoxide Radical Dismutation by a Manganese(II) Complex with an N‐Tripodal Ligand
Authors: Durot Stéphanie , Lambert François , Renault Jean‐Philippe , Policar Clotilde
Published: May 2005

This article presents a pulse radiolysis study of the reactivity of a SOD‐mimic MnII complex [MnII(IPG)]+ 1 with superoxide. It uses an improved set‐up with a circulating cell. It provides convergent pieces of evidence that 1 catalyses efficiently the dismutation of superoxide. Three sets of experiments are described: (1) Transient formation and decay of an adduct labeled {MnOO}6 were studied. (2) A multi‐pulse experiment showed a reproducible behaviour upon successive superoxide pulses. (3) Superoxide decay was monitored at 270 nm to provide an overall kinetic constant. A mechanism is proposed. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Synthetic, Structural, Spectroscopic, and Electrochemical Studies of Heteroleptic Tris(phthalocyaninato) Rare Earth Complexes
Authors: Bian Yongzhong , Li Lei , Wang Daqi , Choi Chi‐Fung , Cheng Diana Y. Y. , Zhu Pehua , Li Renjie , Dou Jianmin , Wang Rongming , Pan Na , Ng Dennis K. P. , Kobayashi Nagao , Jiang Jianzhuang
Published: May 2005

Three heteroleptic tris(phthalocyaninato) rare‐earth triple‐decker complexes [(Pc)M(Pc)M{Pc(α‐OC5H11)4}] [M = Sm, Gd, Lu; Pc = phthalocyaninate; Pc(α‐OC5H11)4 = 1,8,15,22‐tetrakis(3‐pentyloxy)phthalocyaninate] have been prepared as racemic mixtures by treating [M{Pc(α‐OC5H11)4}(acac)], generated in situ, with the bis(phthalocyaninato) rare‐earth double‐decker complex [M(Pc)2] in refluxing n‐octanol. The molecular structures of the gadolinium and lutetium complexes have been determined by single‐crystal X‐ray diffraction analysis, both of which adopt the asymmetrical structure [(Pc)M(Pc)M{Pc(α‐OC5H11)4}]. The outer Pc and Pc(α‐OC5H11)4 rings are significantly domed, while the inner Pc ring is essentially planar. The ring‐to‐ring separation between the two adjacent Pc rings, as defined by the two N4 mean planes, diminishes from [(Pc)Gd(Pc)Gd{Pc(α‐OC5H11)4}] to [(Pc)Lu(Pc)Lu{Pc(α‐OC5H11)4}] as a result of the smaller LuIII ion. The decreased molecular symmetry for these complexes has also been revealed by the NMR spectra of the samarium and lutetium analogs, in which four sets of signals appear for the inner Pc ring protons due to the special disposition of the neighboring Pc(α‐OC5H11)4 ring. Electrochemical studies have revealed four one‐electron oxidations and up to five one‐electron reductions for these complexes. The dependence of the phthalocyanine Q band as well as the first and second oxidation potentials on the size of the metal center indicates that substantial π‐π interactions are present in these compounds. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Stereoselective Michael‐Type Addition of Organocopper Reagents to Enones Derived from Glycals in the Synthesis of 2‐Phosphono‐α‐C‐Glycosides
Authors: Leonelli Francesca , Capuzzi Marinella , Calcagno Vincenzo , Passacantilli Pietro , Piancatelli Giovanni
Published: May 2005

Michael‐type additions of various organocopper reagents to the novel carbohydrate‐derived 2‐(diethoxyphosphoryl)hex‐1‐en‐3‐uloses are described. The reactions have proved to be rapid, clean and stereoselective, giving rise to the formation of 3‐oxo‐2‐phosphono‐α‐C‐glycosides or the corresponding enol acetates. These compounds are direct precursors of 2‐phosphono‐α‐C‐glycosides, a very interesting class of molecules never described before. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Divergent and Linear Solid‐Phase Synthesis of PNA Containing Thiazole Orange as Artificial Base
Authors: Jarikote Dilip V. , Köhler Olaf , Socher Elke , Seitz Oliver
Published: May 2005

Fluorescent nucleobase surrogates provide nucleic acids with interesting properties. We have recently introduced thiazole orange as base surrogate into PNA and found that the so‐called FIT (Forced Intercalation of Thiazole orange) PNA probes signal hybridization by enhancements of fluorescence. Common approaches of modifying nucleobases or introducing nucleobase surrogates draw upon the usage of monomer building blocks that have been synthesized in solution phase. The need to prefabricate a base‐modified building block can hold up progress if several base modifications or base surrogates are to be evaluated. Herein, a method for divergent solid‐phase synthesis is presented that serves the purpose to facilitate the screening for base surrogates that fluoresce upon hybridization. An Fmoc/Aloc‐protected submonomer allowed the application of commonly used Fmoc‐based solid‐phase synthesis protocols while removal of the fully orthogonal Aloc group enabled the on‐resin introduction of base surrogates after the linear chain assembly had been completed. The divergent solid‐phase synthesis strategy is automatable, gives overall yields matching those of linear solid‐phase synthesis and, most importantly, provides rapid access to any kind of base‐modified PNA. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Radiation Grafted Membranes for Polymer Electrolyte Fuel Cells
Authors: Gubler L. , Gürsel S. A. , Scherer G. G.
Published: May 2005

The cost of polymer electrolyte fuel cell (PEFC) components is crucial to the commercial viability of the technology. Proton exchange membranes fabricated via the method of radiation grafting offer a cost‐competitive option, because starting materials are inexpensive commodity products and the preparation procedure is based on established industrial processes. Radiation grafted membranes have been used with commercial success in membrane separation technology. This review focuses on the application of radiation grafted membranes in fuel cells, in particular the identification of fuel cell relevant membrane properties, aspects of membrane electrode assembly (MEA) fabrication, electrochemical performance and durability obtained in cell or stack tests, and investigation of failure modes and post mortem analysis. The application in hydrogen and methanol fuelled cells is treated separately. Optimized styrene / crosslinker grafted and sulfonated membranes show performance comparable to perfluorinated membranes. Some properties, such as methanol permeability, can be tailored to be superior. Durability of several thousand hours at practical operating conditions has been demonstrated. Alternative styrene derived monomers with higher chemical stability offer the prospect of enhanced durability or higher operating temperature.
A method for determining the magnitude of change across different cognitive functions in clinical trials: the effects of acute administration of two different doses alprazolam
Authors: Snyder Peter J. , Werth John , Giordani Bruno , Caveney Angela F. , Feltner Douglas , Maruff Paul
Published: May 2005

While there is no doubt that benzodiazepine administration leads to transient cognitive impairment in healthy adults, the nature and magnitude of such impairment has not been well described. The cognitive effects of a single dose of alprazolam 0.5 and 1 mg were therefore assessed in 36 healthy adults on measures of psychomotor function, visual attention, working memory, planning and learning in a double‐blind parallel‐groups study. Measures of these different cognitive functions were selected on the basis of their brevity and because they yielded distributions of performance data that were without skew, floor or ceiling effects of range restriction (i.e. normal distributions). With data satisfying the assumptions for parametric analysis, measures of effect size could be computed in addition to significance testing, thus allowing for direct and meaningful comparison between the different performance measures used. Alprazolam 0.5 mg reduced only the speed of attentional performance although the magnitude of this reduction was large (d = 0.8). At 1.0 mg, impairments in psychomotor function, equivalent to that seen for attentional function at the lower dose, were observed. In addition, moderate (d approx = 0.5) impairments in working memory, and learning also became obvious. When considered together, these results suggest that low‐dose alprazolam primarily alters visual attentional function. At the higher dose psychomotor functions also become impaired, and it is likely that the combination of these led to the observed moderate impairments in higher level executive and memory processes. The current study also illustrates a method for directly comparing the magnitude of change in cognitive function between measures with different performance metrics. Copyright © 2005 John Wiley & Sons, Ltd.
The effect of escitalopram on sleep problems in depressed patients
Authors: Lader M. , Andersen H. F. , Bækdal T.
Published: May 2005

The results from three 8‐week escitalopram studies in major depressive disorder are presented with respect to efficacy and the effect on sleep quality, both in the full population and the subpopulation of patients with sleep problems at baseline.

Analysis of pooled data from these randomized, double‐blind, placebo‐controlled, studies in which citalopram was the active reference, showed a significant improvement for escitalopram‐treated patients (n = 52·0) in the Montgomery‐Åsberg depression rating scale (MADRS) item 4 (‘reduced sleep’) scores at weeks 6 and 8 compared with placebo (n=398; p < 0.01) and at weeks 4, 6 and 8 (n = 403; p < 0.05) compared with citalopram.

Escitalopram‐treated patients with sleep problems (MADRS item 4 score ≥ 4; n = 254) at baseline showed a statistically significant improvement in mean MADRS item 4 scores at weeks 4, 6 and 8 compared with patients treated with placebo (n = 191; p < 0.05) or citalopram (n = 193; p < 0.01). These patients also showed a statistically significant (p < 0.05) and clinically relevant improvement in MADRS total score after escitalopram treatment compared with citalopram at weeks 1, 4, 6 and 8 (observed cases) and endpoint (−2.45; last observation carried forward [LOCF]). Statistical significance in favour of escitalopram versus placebo treatment was found at all visits, including endpoint (−4.2; LOCF).

Thus, these post‐hoc analyses suggest that escitalopram has a significant beneficial effect compared with placebo or citalopram in reducing sleep disturbance in patients suffering from major depressive disorder. The effect of escitalopram in improving ‘reduced sleep’ scores was clearly seen in patients with more severe sleep disturbance at baseline. A further prospective study is needed to establish this useful clinical effect in insomniac depressives. Copyright © 2005 John Wiley & Sons, Ltd.
Safety and tolerability of duloxetine in the treatment of major depressive disorder: analysis of pooled data from eight placebo‐controlled clinical trials
Authors: Hudson James I. , Wohlreich Madelaine M. , Kajdasz Daniel K. , Mallinckrodt Craig H. , Watkin John G. , Martynov Oleg V.
Published: May 2005

Objective

To examine the safety and tolerability of the antidepressant duloxetine across multiple studies for major depressive disorder (MDD).

Method

Safety data were integrated from the acute phases of eight double‐blind, placebo‐controlled trials in which patients were randomized to duloxetine (40–120 mg/d; n = 1139) or placebo (n = 777) for up to 9 weeks. This data set included all acute‐phase clinical trials that formed the basis of the New Drug Application (United States) or European Union submission package for duloxetine in the treatment of MDD. Two studies included continuation phases in which acute treatment responders received duloxetine or placebo for an additional 26 weeks. Safety assessments included serious adverse event reports, rates of discontinuation, spontaneously reported treatment‐emergent adverse events, changes in vital signs and laboratory values, and electrocardiograms.

Results

The rates of serious adverse events for duloxetine‐ and placebo‐treated patients were 0.3% and 0.6%, respectively (p = 0.282). Adverse events led to discontinuation in 9.7% of duloxetine‐treated patients, compared with 4.2% of patients receiving placebo (p < 0.001). Treatment‐emergent adverse events with an incidence for duloxetine ≥ 5.0% and significantly greater than placebo were nausea, dry mouth, constipation, insomnia, dizziness, fatigue, somnolence, increased sweating and decreased appetite. Mean changes in blood pressure and heart rate were small, and the incidence of increases above normal ranges was low. Duloxetine‐treated patients had a mean decrease in weight of 0.5 kg compared with an increase of 0.2 kg for patients receiving placebo (p < 0.001). No significant differences were found between duloxetine and placebo in the incidence of potentially clinically significant laboratory values at anytime while on treatment.

Conclusion

These results are consistent with those obtained previously from smaller pooled data sets, and suggest that duloxetine is safe and well tolerated in patients with MDD. Copyright © 2005 John Wiley & Sons, Ltd.
Gelatin/chondroitin‐6‐sulfate copolymer scaffold for culturing human nucleus pulposus cells in vitro with production of extracellular matrix
Authors: Yang Shu‐Hua , Chen Po‐Quang , Chen Yi‐Fang , Lin Feng‐Huei
Published: May 2005

Tissue‐engineering approaches for treating degenerative intervertebral discs aim to regenerate intervertebral disc tissues in order to retard or even reverse the degenerative process. This study was designed to investigate the feasibility of the glutaraldehyde crosslinked gelatin/chondroitin‐6‐sulfate copolymer scaffold to serve as a bioactive scaffold for culturing human nucleus pulposus (NP) cells in vitro with preservation of the cell viability, cell proliferation, and production of important extracellular matrix, including glycoaminoglycans (GAG) and Type II collagen. Each experimental sample was seeded with 1 × 106 human NP cells, and then the cell–scaffold hybrids were cultured in vitro for 6 or 12 weeks. SEM showed a highly porous structure with an average pore size of 100 μm in the copolymer scaffold. Immediately after cell seeding, SEM showed that the seeded cells penetrated deeply and distributed evenly in the copolymer scaffold. Water‐soluble tetrazolium salt‐1 (WST‐1) assay showed good viability and active proliferation of cultured human NP cells in the copolymer scaffolds up to 12 weeks. The cell–scaffold hybrids contained significantly higher levels of sulfated GAG than the control samples (41.29 μg vs 6.04 μg per scaffold). Immunohistochemical study showed Type II collagen fibrils on the surface of scaffold substrate after 6 weeks of cultivation. More abundant deposition of Type II collagen could be detected after 12 weeks. The results achieved in this study indicate that the gelatin/chondroitin‐6‐sulfate copolymer scaffold is a promising bioactive scaffold for regeneration of nucleus pulposus tissue. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2005
Effect of laser perforation on the remodeling of acellular matrix grafts
Authors: Bergmeister Helga , Boeck Peter , Kasimir Marie‐Theres , Fleck Tatjana , Fitzal Florian , Husinsky Wolfgang , Mittlboeck Martina , Stoehr Hans Georg , Losert Udo , Wolner Ernst , Grabenwoeger Martin
Published: May 2005

Autologous cells migrate only slightly into acellular matrix grafts. This study was carried out in small‐diameter, allogeneic matrix grafts to investigate the effects on cell repopulation and remodeling caused by increased wall porosity induced by laser perforation. Allogeneic ovine carotid arteries were decellularized by dye‐mediated photooxidation (Photofix™). Matrix grafts (10 cm × 4 mm i.d.) were perforated with holes of 50 μm diameter at a density of 50 holes/cm2 using a Ti–sapphire laser. The grafts were implanted in the carotid arteries of 10 sheep and were compared to nonperforated grafts implanted contralaterally. The prostheses were retrieved after 6 weeks or 3 or 6 months following implantation and were evaluated by histologic examination, immunohistochemical staining, and scanning electron microscopy. All grafts, except one of the perforated specimens, remained patent. Perforated implants, examined at 6 weeks, showed faster recellularization with endothelial cells than did the corresponding contralateral controls. Perforated grafts, examined at 6 months, showed a significantly thicker neointima and clear signs of neovascularization: endothelial cells, basal lamina, elastic fibers, circular and longitudinally orientated smooth muscle cells in comparison to nonperforated specimens. Repopulation of the decellularized matrix with host cells was higher in the perforated than in the nonperforated prostheses. These results suggest that the increased matrix porosity induced by laser perforation promotes graft remodeling and reconstitution with host cells. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2005
Towards automated 3D finite element modeling of direct fiber reinforced composite dental bridge
Authors: Li Wei , Swain Michael V. , Li Qing , Steven Grant P.
Published: May 2005

An automated 3D finite element (FE) modeling procedure for direct fiber reinforced dental bridge is established on the basis of computer tomography (CT) scan data. The model presented herein represents a two‐unit anterior cantilever bridge that includes a maxillary right incisor as an abutment and a maxillary left incisor as a cantilever pontic bonded by adhesive and reinforced fibers. The study aims at gathering fundamental knowledge for design optimization of this type of innovative composite dental bridges. To promote the automatic level of numerical analysis and computational design of new dental biomaterials, this report pays particular attention to the mathematical modeling, mesh generation, and validation of numerical models. To assess the numerical accuracy and to validate the model established, a convergence test and experimental verification are also presented. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2005
Degree bounds for the circumference of 3‐connected graphs
Authors: Jung Heinz A. , Vumar Elkin
Published: May 2005

Let C be a longest cycle in the 3‐connected graph G and let H be a component of G − V(C) such that |V(H)| ≥ 3. We supply estimates of the form |C| ≥ 2d(u) + 2d(v) − α(4 ≤ α ≤ 8), where u,v are suitably chosen non‐adjacent vertices in G. Also the exceptional classes for α = 6,7,8 are characterized. © 2005 Wiley Periodicals, Inc. J Graph Theory
Non‐linear performance comparison for FD and PD SOI MOSFETs based on the integral function method and Volterra modelling
Authors: Parvais B. , Cerdeira A. , Schreurs D. , Raskin J.‐P.
Published: May 2005

The harmonic and intermodulation distortions of both fully‐depleted (FD) and partially‐depleted (PD) silicon‐on‐insulator (SOI) MOSFETs are studied. The analysis is based on the recently developed integral function method and the results are compared to a third‐order Volterra model of the MOSFET. This modelling helps us to understand the non‐linear mechanisms of the considered devices and to predict their frequency behaviour. The models are validated through large‐signal network analyser measurements. The devices performances are discussed. Copyright © 2005 John Wiley & Sons, Ltd.
Risk Stratification and Targeted Antifungal Prophylaxis for Prevention of Aspergillosis and Other Invasive Mold Infections After Liver Transplantation
Authors: Hellinger Walter C. , Bonatti Hugo , Yao Joseph D. , Alvarez Salvador , Brumble Lisa M. , Keating Michael R. , Mendez Julio C. , Kramer David J. , Dickson Rolland C. , Harnois Denise M. , Spivey James R. , Hughes Christopher B. , Nguyen Justin H. , Steers Jeffery L.
Published: May 2005

Antifungal prophylaxis has been proposed for liver transplant recipients at increased risk for invasive mold infection. Risk factors for invasive mold infection after liver transplantation were selected to divide recipients into 3 groups: (1) high risk—transplantation on hemodialysis or delay of hospital discharge beyond day 7 after transplantation because of allograft or renal insufficiency; (2) intermediate risk—retransplantation or transplantation for fulminant hepatic failure; (3) low risk—absence of conditions in groups 1 and 2. During an intervention period (February 1999–April 2001), prophylactic administration of a lipid complex of amphotericin (Abelcet) at 5 mg/kg intravenously every 24 to 48 hours was recommended for high-risk recipients. The frequency of mold infection was compared to that of a preintervention period (February 1998–January 1999) when antifungal prophylaxis was not provided. During the intervention period, invasive mold infection developed in 2 (6%) of 35 high-risk recipients, 0 of 28 intermediate-risk recipients, and 1 (0.5%) of 187 low-risk recipients. Overall, of 58 liver transplant recipients, 3 (5%) developed an invasive mold infection during the preintervention period, compared with 3 (1%) of 250 during the intervention period (

P

= 0.08). The only death from invasive mold infection occurred during the preintervention period. Rates of pulse corticosteroid treatment of rejection and cytomegalovirus infection were lower during the intervention period. In conclusion, readily identifiable patient characteristics can be used to stratify liver transplant recipients for risk of invasive mold infection. Antifungal prophylaxis given to high-risk recipients may provide cost-effective prevention of these infections.
Tobacco Use Following Liver Transplantation for Alcoholic Liver Disease: An Underestimated Problem
Authors: DiMartini Andrea , Javed Lubna , Russell Sarah , Dew Mary Amanda , Fitzgerald Mary Grace , Jain Ashok , Fung John
Published: May 2005

Alcohol and tobacco use commonly co-occur, with at least 90% of those with an alcohol problem also using tobacco. Thus, 3 years ago when we discovered higher rate of late deaths due to lung and oropharyngeal cancer in patients who had received a transplant for alcoholic liver disease (ALD), we hypothesized that these patients were continuing to expose themselves to tobacco after liver transplantation (post-LTX) and that this behavior was increasing their risk for cancer. We subsequently began a prospective investigation of post-LTX tobacco use in patients having undergone LTX for ALD (n = 172). For 33 recipients we had data starting from our first assessment at 3 months post-LTX and for this subgroup we report on the details of the timing of tobacco use resumption and the redevelopment of nicotine addiction. We found that on average more than 40% are smoking across all time periods. ALD recipients resume smoking early post-LTX, increase their consumption over time, and quickly become tobacco dependent. These data highlight an underrecognized serious health risk for these patients and demonstrate our need for more stringent clinical monitoring and intervention for tobacco use in the pre- and post-LTX periods.
Modulation of Mitochondrial Calcium Management Attenuates Hepatic Warm Ischemia-Reperfusion Injury
Authors: Anderson Christopher D. , Pierce Janene , Nicoud Ian , Belous Andrey , Knox Clayton D. , Chari Ravi S.
Published: May 2005

Hepatic warm ischemia and reperfusion (IR) injury occurs in many clinical situations and has an important link to subsequent hepatic failure. The pathogenesis of this injury involves numerous pathways, including mitochondrial-associated apoptosis. We studied the effect of mitochondrial calcium uptake inhibition on hepatic IR injury using the specific mitochondrial calcium uptake inhibitor, ruthenium red (RR). Rats were subjected to 1 hour of 70% warm hepatic ischemia following RR pretreatment or vehicle injection. Sham-operated animals served as controls. Analysis was performed at 15 minutes, 1 hour, 3 hours, or 6 hours after reperfusion. Serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) concentrations were determined. Terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling (TUNEL) staining was performed to assess apoptosis, and hepatocellular necrosis was semiquantitated from hematoxylin and eosin–stained tissue sections. RR pretreatment significantly decreased both AST and ALT serum levels after 6 hours of reperfusion (AST: 1,556 ± 181 U/L vs. 597 ± 121 U/L,

P

= 0.005; ALT: 1,118 ± 187 U/L vs. 294 ± 39 U/L,

P

= 0.005). Apoptosis was observed within 15 minutes of reperfusion in vehicle-pretreated animals and peaked after 3 hours of reperfusion (98 ± 21 cells/high-power field [hpf]). Apoptosis was inhibited at all time points by RR pretreatment. Histologic evidence of necrosis was not observed prior to 3 hours of reperfusion (23% ± 4%), and maximal necrosis was observed after 6 hours of reperfusion (26% ± 1% percent area). RR pretreatment significantly decreased the necrotic percent area at both the 3-hour and the 6-hour time points (4.2% ± 2%; 3.7% ± 1%, respectively). Hepatic IR injury resulted in both apoptotic and necrotic cell death, which were attenuated by RR pretreatment. In conclusion, these observations implicate mitochondrial calcium uptake in the pathogenesis of hepatic IR injury.
Impact of Donor Gender on Male Rat Recipients of Small-for-Size Liver Grafts
Authors: Gu Yanli , Dirsch Olaf , Dahmen Uta , Ji Yuan , He Qing , Chi Haidong , Broelsch Christoph Erich
Published: May 2005

The aim of this study was to assess the impact of donor gender on small-for-size (SFS) liver transplantation in male recipients using a rat model. Adult female or male Lewis rats were used as donors and male Lewis rats as recipients. Size-matched (SM) and SFS liver grafts from either male or female donors were transplanted into male recipients. Animals receiving SFS grafts were sacrificed at postoperative week 1, week 4, and week 12, respectively (n = 6-8 per group), those receiving SM grafts after 3 months. The cumulative survival rate (SVR) in the female-to-male (F-M) SFS group was significantly lower (62%; 13 of 21) compared with the male-to-male (M-M) group (90%; 18 of 20) (

P

< 0.05). Spontaneous death occurred in the F-M SFS combination either in the early postoperative period (<3 weeks) in animals with confluent hepatic necrosis or in the late postoperative period (>8 weeks) in animals with biliary obstruction. In contrast, no death was observed in the early posttransplantation period after M-M liver transplantation. The relative graft size in the SM F-M group was significantly higher (graft-to-recipient weight ratio [GRWR] 2.40% ± 0.8%) than in the SFS M-M group (GRWR 1.35% ± 0.2%;

P

< 0.001). Regardless of graft size, the outcome was worse in terms of SVR as well as regarding the incidence and severity of biliary complications in F-M compared with M-M liver transplantation. In conclusion, male recipients of female livers had a less favorable outcome irrespective of graft size. Confluent hepatic necrosis as well as biliary obstruction were perceived as consequence of a severe perfusion problem in F-M liver transplantation, which was possibly related to an enhancement of ischemia-reperfusion (I/R) injury by the lack of estrogen in male recipients of female grafts.
Liver Transplant Recipient Selection: MELD vs. Clinical Judgment
Authors: Fink Michael A. , Angus Peter W. , Gow Paul J. , Berry Roger S. , Wang Bao-Zhong , Muralidharan Vijayaragavan , Christophi Christopher , Jones Robert M.
Published: May 2005

Minimization of death while waiting for liver transplantation involves accurate prioritization according to clinical status and appropriate allocation of donor livers. Clinical judgment in the Liver Transplant Unit Victoria (LTUV) was compared with Model for End-Stage Liver Disease (MELD) in a retrospective analysis of the LTUV database over the 2-year period August 1, 2002, through July 31, 2004. A total of 1,118 prioritization decisions occurred. Decisions were concordant in 758 (68%), comparing priorities assigned by clinical judgment with those assigned by MELD,

P

< 0.01. A total of 263 allocation decisions occurred. Decisions were concordant in 190 (72%) and 203 (77%) of the cases, comparing donor liver allocation with prioritization by MELD and clinical judgment, respectively. Of the 52 patients allocated a liver, only 23 would have been allocated on the basis of MELD while 29 had been prioritized on the waiting list in the week prior to transplantation. A total of 10 patients died on the waiting list in the 2-year period (annual adult waiting list mortality is 9.3%). Patients who subsequently died waiting were 3 times as likely to be prioritized by MELD as clinical judgment (29% vs. 9%, respectively). One half (3 of 6) of the patients who could have received a donor liver but who died waiting would have been allocated the organ on the basis of MELD. In conclusion, an allocation process based on MELD rather than clinical judgment would significantly alter organ allocation in Australia and may reduce waiting list mortality.
Liver Transplantation for Severe Intrahepatic Noncirrhotic Portal Hypertension
Authors: Krasinskas Alyssa M. , Eghtesad Bijan , Kamath Patrick S. , Demetris Anthony J. , Abraham Susan C.
Published: May 2005

Intrahepatic noncirrhotic portal hypertension can be idiopathic or associated with known toxic, developmental, vascular, or biliary tract diseases. Most patients are successfully managed medically or with shunting procedures. The goal of this study was to explore the reasons some patients require orthotopic liver transplantation (OLT). The clinical features, gross and microscopic liver explant pathology, and posttransplantation course in 16 patients who underwent OLT for intrahepatic noncirrhotic portal hypertension were studied. There were 11 men and 5 women with a mean age of 47 years. Clinical manifestations included gastrointestinal varices (n = 12), ascites (n = 8), encephalopathy (n = 3), and hepatopulmonary syndrome (n = 3). Cirrhosis was misdiagnosed clinically, radiographically and/or histologically in 13 patients (81%). Grossly, liver explants weighed a mean of 1,100 g, and 12 had a nodular appearance. Histologically, all 16 livers had portal tract vascular abnormalities, 15 had nodular regenerative hyperplasia (NRH), and 9 had incomplete septal cirrhosis. After OLT, mild NRH features were noted in 2 patients, and 1 of these patients developed evidence of portal hypertension. This study demonstrates that a subset of patients with intrahepatic noncirrhotic portal hypertension have severe symptoms requiring OLT. Accurate pre-OLT diagnosis is frequently difficult at advanced stages of the disease; 81% of our patients carried a diagnosis of cirrhosis. Morphologically, the explanted livers showed evidence of vascular abnormalities, NRH, and increased fibrosis, but not cirrhosis. Importantly, however, a diagnosis of cirrhosis is not required in this group of patients to qualify them for OLT, and these patients have good long-term graft function after OLT.
Dynamic Left Ventricular Outflow Tract Obstruction in An Orthotopic Liver Transplant Recipient
Authors: Cywinski Jacek B. , Argalious Maged , Marks Theodore N. , Parker Brian M.
Published: May 2005

A 53 year-old man with Laennec's and hepatitis C–related cirrhosis was found to have dynamic left ventricular outflow tract obstruction during routine evaluation for orthotopic liver transplantation. The outflow tract obstruction gradient was quantified as being 155 to 189 mmHg maximally during dobutamine stress echocardiography. The patient subsequently underwent successful orthotopic liver transplantation at our institution. We discuss here the use of intraoperative transesophageal echocardiography to detect early signs of dynamic outflow tract obstruction and provide a rational guide for fluid and hemodynamic management. We conclude that the measured pressure across the left ventricular outflow tract during dobutamine stress testing does not necessarily predict either intraoperative hemodynamic perturbations such as obstruction or outcome in these patients.
Polymerisation of Acrylates Catalysed by Methylaluminoxane Activated Ditertiary Phosphine Complexes of Iron and Cobalt Dichlorides
Authors: Castro Pascal M. , Lankinen Mikko P. , Leskelä Markku , Repo Timo
Published: May 2005

Summary: Diphosphane complexes of iron(II) are active catalysts for the polymerisation of methyl acrylate (MA) monomers in the presence of methylaluminoxane (MAO). High molar mass atactic MA polymers ($\overline M _{\rm n}$ ∼ 200 kg/mol) were obtained under mild conditions with relatively narrow polydispersities (PDI ∼ 2). Polymerisation activity and polymer molar masses are strongly dependent on the ligand frame. The polymerisation requires the coordination of MA to a vacant coordination site at the metal centre, and processes with chain‐transfer to aluminium. Cobalt analogues proved to be less efficient catalysts, giving activities in the range of 50–250 kg/mol · h instead of 200–450 kg/mol · h for the iron complexes. MAO activated FeCl2 and CoCl2 salts also perform the polymerisation of MA with low activity.

Ditertiary phosphine complex of iron(II) chloride as methyl acrylate polymerisation catalyst.

image

Ditertiary phosphine complex of iron(II) chloride as methyl acrylate polymerisation catalyst.
Controlled Anionic Block Copolymerization with N,N‐Dialkylacrylamide as a Second Block
Authors: Vinogradova Ljudmila , Fedorova Ljubov , Adler Hans‐Juergen P. , Kuckling Dirk , Seifert Denis , Tsvetanov Christo B.
Published: May 2005

Summary: Novel well‐defined block copolymers composed of polystyrene, poly(2‐vinylpyridine), poly(ethylene oxide), or poly(tert‐butyl methacrylate) as the first block and poly(N,N‐dialkylacrylamide) (PDAlAAm) as the second block were synthesized by ligated anionic polymerization. The latter was carried out in tetrahydrofuran (THF) initiated by 1,1‐diphenyloligostyryllithium in the presence of ZnEt2 and LiCl. At first the role of the additives LiCl and ZnEt2 on the mode of the anionic homopolymerization of N,N‐dialkylacrylamide was investigated. Polymerization in the presence of ZnEt2 resulted in syndiotactic polymers with narrow molecular weight distribution only. In the presence of both additives, the reaction mixture became heterogeneous with a high degree of isotacticity of the polymers. Despite the fact that the polymerizations were performed in heterogeneous phase, the DAlAAm monomers were polymerized in a quantitative yield. The efficiency of the first block of active sites was always higher than 0.71. Preliminary studies using dynamic light scattering of aqueous hydrochloric acid solutions of poly[(2‐vinylpyridine)‐block‐(N,N‐diethylacrylamide)] block copolymers at different temperatures and at pH 2 showed that above 45 °C, micelle‐like aggregates were formed. The heating and cooling cycles were reversible but showed hysteresis, which was obviously due to the isotactic structure of the poly(N,N‐diethylacrylamide) block.

Temperature dependence of the scattering intensity of various poly[(2‐vinylpyridine)‐block‐(N,N‐diethylacrylamide)] block copolymers.

image

Temperature dependence of the scattering intensity of various poly[(2‐vinylpyridine)‐block‐(N,N‐diethylacrylamide)] block copolymers.
Saturated Red Light‐Emitting Copolymers of Poly(aryleneethynylene)s with Narrow‐Band‐Gap (NBG) Units: Synthesis and Luminescent Properties
Authors: Shi Chenjun , Wu Yun , Zeng Wenjin , Xie Yuqing , Yang Kaixia , Cao Yong
Published: May 2005

Summary: A series of novel poly(fluoreneethynylene) (PFE) copolymers containing a molar ratio less than or equal to 50% of narrow‐band‐gap (NBG) comonomers, 4,7‐dithienyl‐2,1,3‐benzothiadiazole (DBT), and 2,1,3‐benzothiadiazole (BT), is prepared by the Pd‐Cu‐catalyzed coupling reaction. The copolymers are soluble in common organic solvents. All the polymers are fluorescent in solution and in solid state. Chemical and photophysical properties of these copolymers were thoroughly studied. Devices based on the copolymers emit saturated red light, and the emission slightly red‐shifted gradually with increasing NBG comonomer content. The maximal external quantum efficiency of the polymer light‐emitting diodes (PLED) reaches 0.41% with the emission maximum at 638 nm.

Synthesis of PFE by Pd‐Cu‐catalyzed coupling reaction.

image

Synthesis of PFE by Pd‐Cu‐catalyzed coupling reaction.
Cover: Macromol. Mater. Eng. 5/2005
Authors: Rodgers Reneé M. , Mahfuz Hassan , Rangari Vijaya K. , Chisholm Nathaniel , Jeelani Shaik
Published: May 2005

Cover: The picture on the cover shows the crack formation in epoxy (or polymer) nanocomposites. Further details can be found in the Full Paper by R. M. Rodgers, H. Mahfuz,* V. K. Rangari, N. Chisholm, and S. Jeelani on page 423.
The face of the un‐consumer: An empirical examination of the practice of voluntary simplicity in the United States
Authors: Huneke Mary E.
Published: May 2005

The practice of voluntary simplicity is inextricably linked to consumer behavior and has attracted the attention of researchers in a number of disciplines, including psychology and marketing. Yet the daily practice of voluntary simplicity in the United States remains largely unexamined. The research presented here is the first to look at voluntary simplicity with the use of a nationwide sample of American consumers. A more refined application of Maslow's theory of human motivation to the understanding of this social phenomenon is proposed. The practices considered most important to this lifestyle are identified, as are key impediments to its consistent practice. Factor analysis is used to identify the underlying dimensions of U.S. voluntary simplicity: ecological and social responsibility; community; and maintaining a spiritual life. Findings indicate that people of moderate income are more likely to practice voluntary simplicity than was previously believed. This research also compares highly committed simplifiers to those who are less committed, finding that more committed practitioners are more likely to be consistent in practices requiring ongoing effort, such as composting. © 2005 Wiley Periodicals, Inc.
Molecular Evolution of Polymers through Photoageing: A New UV in situ Viscoelastic Technique
Authors: Verney Vincent , Commereuc Sophie
Published: May 2005

Summary: Dienic elastomers are highly sensitive towards oxidation. During UV exposure, both scission and/or recombination reactions compete which involves an evolution of the molecular structure of the material. We developed an in situ technique to monitor the viscoelastic property changes upon UV irradiation of polymers in a single experiment. We illustrated this photorheology technique in the case of two kinds of elastomers. From our findings, this method is assumed to bring significant new advantages.

Photograph of the photorheometer used in this study.

magnified image

Photograph of the photorheometer used in this study.
Photoswitchable Smectic Liquid‐Crystalline Elastomers
Authors: Beyer Patrick , Zentel Rudolf
Published: May 2005

Summary: We succeeded in the synthesis of azo side chain containing polysiloxanes with broad smectic C* and A phases. In these polymers the phase transition temperatures can be shifted reversibly by up to 17 °C by irradiation with UV (cis) or VIS (trans) light. Thin films of these polymers in the smectic phase (both on substrates and as free‐standing films) orient perfectly in a homeotropic manner. As a consequence, the azo chromophores do no longer absorb during a perpendicular illumination with light (dichroism). It is thus possible to crosslink these films photochemically to prepare “photoswitchable smectic LC elastomers”.

The trans‐cis isomerization in homeotropically oriented LC elastomers.

magnified image

The trans‐cis isomerization in homeotropically oriented LC elastomers.
Expression profiling the human septin gene family
Authors: Hall Peter A , Jung Kenneth , Hillan Kenneth J , Russell SE Hilary
Published: May 2005

The septins are an evolutionarily conserved family of GTP‐binding proteins involved in diverse processes including vesicle trafficking, apoptosis, remodelling of the cytoskeleton, infection, neurodegeneration, and neoplasia. The present paper reports a comprehensive study of septin gene expression by DNA microarray methods in 10 360 samples of normal, diseased, and tumour tissues. A novel septin, SEPT13, has been identified and is shown to be related to SEPT7. It is shown that SEPT13 and the other known human septins are expressed in all tissue types but some show high expression in lymphoid (SEPT1, 6, 9, and 12) or brain tissues (SEPT2, 3, 4, 5, 7, 8, and 11). For a given septin, some isoforms are highly expressed in the brain and others are not. For example, SEPT8_v2 and v1, 1* and 3 are highly expressed in the brain and cluster with SEPT2, 3, 4, 5, 7, and 11. However, a probe set specific for SEPT8_v1 with low brain expression clusters away from this set. Similarly, SEPT4 has lymphoid and non‐lymphoid forms; SEPT2 has lymphoid and central nervous system (CNS) forms; and SEPT6 and SEPT9 are elevated in lymphoid tissues but both have forms that cluster away from the lymphoid forms. Perturbation of septin expression was widespread in disease and tumours of the various tissues examined, particularly for conditions of the CNS, where alterations in all 13 septin genes were identified. This analysis provides a comprehensive catalogue of the septin family in health and disease. It is a key step in understanding the role of septins in physiological and pathological states and provides insight into the complexity of septin biology. Copyright © 2005 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.