bluuebunny/crossref_metadata_2025 huggingface dataset:
Minimal but significant improvement in survival for non–hepatitis C–related adult liver transplant patients beyond the one-year posttransplant mark
Authors: McCaughan Geoffrey W. , Shackel Nicholas A. , Strasser Simone I. , Dilworth Pamela , Tang Patrick
Published: January 2010

Although 1-year survival rates following liver transplantation over the last 20 years may have improved, there is doubt about improvement in long-term survival. We examined survival with and without initial 12-month mortality in adult liver transplant recipients over a 20-year period. Patient and allograft survival for 3 different time periods was compared: 1986-1994 (group 1, n = 547), 1995-2000 (group 2, n = 735), and 2000-2005 (group 3, n = 749). After this, all deaths in the first 12 months of each group were removed. Patient and allograft survival was then once again compared across the 3 groups. There was significant improvement in both patient and allograft survival across the 20-year period (P < 0.001). Overall patient and allograft survival improved in non–hepatitis C virus (HCV) patients but not in HCV patients. A similar comparison with deaths in the first year removed, however, showed no difference in patient survival (P = 0.07) and only a marginal improvement in allograft survival (P = 0.048) between the 3 time periods. When patients were divided into HCV-positive and HCV-negative groups with deaths in the first year removed, there was, however, improved patient and allograft survival in the HCV-negative group but not in the HCV-positive group. The causes of death between 1 and 5 years were then compared. There were 48 deaths in period 1, 63 in period 2, and 43 in period 3 (P = not significant). There were more deaths due to cardio/cerebrovascular disease and hepatitis B virus recurrence in the first time period, but there were more deaths due to recurrent HCV and de novo malignancy in later time periods. In conclusion, although overall survival following liver transplantation in adults seems to be improving over time, the long-term results are not, particularly in HCV patients.
Impact of pretransplant infections on clinical outcomes of liver transplant recipients
Authors: Sun Hsin-Yun , Cacciarelli Thomas V. , Singh Nina
Published: January 2010

Whether pretransplant nonviral infections influence outcomes after transplantation in liver transplant recipients in the current era is not well defined. One hundred consecutive patients undergoing liver transplantation in 2005-2008 were studied. Demographics, posttransplant clinical events, and mortality were compared between recipients with and without infections within 12 months before transplantation. In all, 32% of the patients (32/100) developed 45 episodes of pretransplant infections, which included spontaneous bacterial peritonitis (35.6%), bloodstream infections (28.9%), cellulitis (13.3%), pneumonia (8.9%), urinary tract infections (6.7%), and other infections (6.7%). Compared with 68 recipients without pretransplant infections, those with infections had a higher Model for End-Stage Liver Disease score and a lower likelihood of transplantation from home and required longer and more frequent hospital care before and after transplantation (P < 0.05). Mortality at 90 (9.4% versus 2.9%) and 180 days (15.6% versus 10.3%) post-transplant did not differ significantly between recipients with and without pretransplant infections (P = not significant). A higher Model for End-Stage Liver Disease score (P < 0.05) and posttransplant infections (P < 0.05 and P < 0.001), but not pretransplant infections, were associated with posttransplant mortality at 90 and 180 days. In conclusion, pretransplant infections that have been adequately treated do not pose a significant risk for poor outcomes, including posttransplant mortality.
Optimization of the cryopreservation and thawing protocol for human hepatocytes for use in cell transplantation
Authors: Terry Claire , Dhawan Anil , Mitry Ragai R. , Lehec Sharon C. , Hughes Robin D.
Published: January 2010

Cryopreservation of human hepatocytes is important for their use in hepatocyte transplantation. On thawing, cryopreserved hepatocytes often have reduced viability and metabolic function in comparison with fresh cells. The aim of this study was to modify the different steps in the standard cryopreservation procedure in an attempt to improve the overall outcome. Human hepatocytes with a viability of 69% ± SD 16% were isolated from donor livers with a collagenase perfusion technique. Different cell densities, concentrations, rates, and methods of addition of dimethyl sulfoxide were tested for the freezing solution. Modified controlled-rate freezer programs were tested to obtain a linear decrease in the temperature. Once they were frozen, the storage time and thawing method for hepatocytes were investigated. The effects on thawed cell viability and attachment, lactate dehydrogenase release, cytochrome P450 1A1/2 activity, and albumin synthesis were determined. The results were used to produce an improved cryopreservation protocol suitable for good manufacturing practice conditions. With a cell density of 107 cells/mL in University of Wisconsin solution containing 300 mM glucose, 10% (vol/vol) dimethyl sulfoxide was added dropwise over 5 minutes, and was immediately frozen. Thawing was done rapidly at 37°C, and dilution was performed with Eagle's minimum essential medium containing 300 mM glucose and 4% human serum albumin. Hepatocytes could be stored at −140°C without significant further loss of function for up to 3 years. With this protocol, hepatocytes had a viability of 52% ± 9%, an attachment efficiency of 48% ± 8%, and lactate dehydrogenase leakage of 17% ± 4%. This protocol is currently in use to cryopreserve hepatocytes for use in cell transplantation at our center.
Health-related quality of life and survival in liver transplant candidates
Authors: Tanikella Rajasekhar , Kawut Steven M. , Brown Robert S. , Krowka Michael J. , Reinen Jenna , Dinasarapu Chandrasekhar R. , Trotter James F. , Roberts Kari E. , Mohd Mustafa A. , Arnett Donna K. , Fallon Michael B.
Published: January 2010

Health-related quality of life (HRQOL) is an important measure of the effects of chronic liver disease in affected patients that helps guide interventions to improve well-being. However, the relationship between HRQOL and survival in liver transplant candidates remains unclear. We examined whether the Physical Component Summary (PCS) and Mental Component Summary (MCS) scores from the Short Form 36 (SF-36) Health Survey were associated with survival in liver transplant candidates. We administered the SF-36 questionnaire (version 2.0) to patients in the Pulmonary Vascular Complications of Liver Disease study, a multicenter prospective cohort of patients evaluated for liver transplantation in 7 academic centers in the United States between 2003 and 2006. Cox proportional hazards models were used with death as the primary outcome and adjustment for liver transplantation as a time-varying covariate. The mean age of the 252 participants was 54 ± 10 years, 64% were male, and 94% were white. During the 422 person years of follow-up, 147 patients (58%) were listed, 75 patients (30%) underwent transplantation, 49 patients (19%) died, and 3 patients were lost to follow-up. Lower baseline PCS scores were associated with an increased mortality rate despite adjustments for age, gender, Model for End-Stage Liver Disease score, and liver transplantation (P for the trend = 0.0001). The MCS score was not associated with mortality (P for the trend = 0.53). In conclusion, PCS significantly predicts survival in liver transplant candidates, and interventions directed toward improving the physical status may be helpful in improving outcomes in liver transplant candidates.
Using In Silico Tools in a Weight of Evidence Approach to Aid Toxicological Assessment
Authors: Ellison Claire M. , Madden Judith C. , Judson Philip , Cronin Mark T. D.
Published: January 2010

Integrated testing strategies are an important and useful approach to reduce animal usage in toxicity testing. Increased usage of integrated testing strategies is foreseen in current chemical legislation, e.g. REACH. Skin sensitisation is a well studied endpoint and many in silico models have been developed for the prediction of the skin sensitising potential of chemicals. This paper discusses the use of the OECD (Q)SAR Application Toolbox, Derek for Windows, the CAESAR global model and SMARTS rules for reactivity within a weight of evidence approach to predict skin sensitisation. Conclusions drawn from a weight of evidence approach can be used within an integrated testing strategy to reduce the requirement for in vivo tests. Using all four models in this manner enabled 76% of the conclusive predictions made regarding the test data to be in agreement with the observed toxicities. In addition, using all four models in conjunction identified areas where further information is required, as confounding results were produced. The actual data requirements for an integrated testing strategy are discussed along with what considerations need to be made for the remaining compounds that were misclassified or for which the programs contradicted one another and a definitive conclusion could not be reached.
Attractors in Sequence Space: Agent‐Based Exploration of MHC I Binding Peptides
Authors: Jäger Natalie , Wisniewska Joanna M. , Hiss Jan A. , Freier Anja , Losch Florian O. , Walden Peter , Wrede Paul , Schneider Gisbert
Published: January 2010

Ant Colony Optimization (ACO) is a meta‐heuristic that utilizes a computational analogue of ant trail pheromones to solve combinatorial optimization problems. The size of the ant colony and the representation of the ants’ pheromone trails is unique referring to the given optimization problem. In the present study, we employed ACO to generate novel peptides that stabilize MHC I protein on the plasma membrane of a murine lymphoma cell line. A jury of feedforward neural network classifiers served as fitness function for peptide design by ACO. Bioactive murine MHC I H‐2Kb stabilizing as well as nonstabilizing octapeptides were designed, synthesized and tested. These peptides reveal residue motifs that are relevant for MHC I receptor binding. We demonstrate how the performance of the implemented ACO algorithm depends on the colony size and the size of the search space. The actual peptide design process by ACO constitutes a search path in sequence space that can be visualized as trajectories on a self‐organizing map (SOM). By projecting the sequence space on a SOM we visualize the convergence of the different solutions that emerge during the optimization process in sequence space. The SOM representation reveals attractors in sequence space for MHC I binding peptides. The combination of ACO and SOM enables systematic peptide optimization. This technique allows for the rational design of various types of bioactive peptides with minimal experimental effort. Here, we demonstrate its successful application to the design of MHC‐I binding and nonbinding peptides which exhibit substantial bioactivity in a cell‐based assay.
Structuring Chemical Space: Similarity‐Based Characterization of the PubChem Database
Authors: Cincilla Giovanni , Thormann Michael , Pons Miquel
Published: January 2010

The ensemble of conceivable molecules is referred to as the Chemical Space. In this article we describe a hierarchical version of the Affinity Propagation (AP) clustering algorithm and apply it to analyze the LINGO‐based similarity matrix of a 500 000‐molecule subset of the PubChem database, which contains more than 19 million compounds. The combination of two highly efficient methods, namely the AP clustering algorithm and LINGO‐based molecular similarity calculations, allows the unbiased analysis of large databases. Hierarchical clustering generates a numerical diagonalization of the similarity matrix. The target‐independent, intrinsic structure of the database , derived without any previous information on the physical or biological properties of the compounds, maps together molecules experimentally shown to bind the same biological target or to have similar physical properties.
Forecasting CYP2D6 and CYP3A4 Risk with a Global/Local Fusion Model of CYP450 Inhibition
Authors: Ewing Todd , Feher Miklos
Published: January 2010

This work presents a method to utilize the ever‐expanding corporate collections of CYP450 inhibition data to forecast the future risk of compounds not yet synthesized. The global/local fusion method differs from existing QSAR methods, in that each prediction is derived from a custom‐built QSAR model, constructed on‐the‐fly, using a customized training set assembled for each prediction. It uses a consensus of global and local descriptor‐based models along with pharmacophore‐based fingerprint similarity to form a prediction and to assess the uncertainty of the prediction on a case‐by‐case basis. We also present a new forward prediction testing and validation scheme in which the corporate dataset is split chronologically, and predictions for a molecule are based on the pool of existing data available before the molecule is registered and tested. The validation accuracy of the CYP2D6 and CYP3A4 models approaches the underlying accuracy of the data, about 0.4 logIC50units standard error (or nearly 70%r2correlation) for the most confident predictions, and extends to about 0.6 logIC50units standard error (or under 30%r2correlation) for the least confident predictions. As a classification model for CYP2D6 and CYP3A4 activity, the validation accuracy is about 79% for predicted actives and 85% for predicted inactives, which is consistent with existing published models.
Probing Small‐Molecule Binding to the Liver‐X Receptor: A Mixed‐Model QSAR Study
Authors: Spreafico Morena , Smiesko Martin , Peristera Ourania , Rossato Gianluca , Vedani Angelo
Published: January 2010

The LXR model has been added in the VirtualToxLab, a fully automated technology that allows for the identification of the endocrine‐disrupting potential of drugs, chemicals and natural products. This protocol has then been applied to screen a series of 161 natural compounds probing their binding to the LXR. The results of the simulation were compared with experimental data (where available) and suggest that the LXR model can be applied to predict the binding affinity of existing or hypothetical compounds for screening purposes. The binding of 52 ligands towards the liver X receptors (LXRs) was identified trough docking to the three‐dimensional protein structure and quantified by multidimensional QSAR (mQSAR), an approach referred to as ‘mixed‐model QSAR’. The model was validated by the prediction of 17 external compounds (oxysterols) present neither in the training nor in the test set. The robustness of the model was verified by consensus scoring using a conceptually different methodology, and chance correlation was ruled out by a series of scramble tests.
Drug‐Target Networks
Authors: Vogt Ingo , Mestres Jordi
Published: January 2010

Far from the traditional view of selective drug‐target interactions, the recent accumulation of large amounts of interaction data for small‐molecule drugs and protein targets requires innovative visualisation and analysis tools that are able to deal with what has become a truly complex system. In this context, network theory offers both a robust and illustrative framework to investigate drug‐target connections and has been swiftly and widely embraced by the chemical biology and molecular informatics communities. A survey of the most recent applications of drug‐target networks to detect cross‐pharmacology relationships among targets and to identify new targets for known drugs is provided. Finally, some of the current limitations are also discussed, including the actual completeness of interaction data and the information loss intrinsically associated with the one‐mode projection of drug‐target networks.
Transporter‐Mediated Efflux Influences CNS Side Effects: ABCB1, from Antitarget to Target
Authors: Broccatelli Fabio , Carosati Emanuele , Cruciani Gabriele , Oprea Tudor I.
Published: January 2010

We examined the relationship between sedation and orthostatic hypotension, two central side effects and ABCB1 transporter‐mediated efflux for a set of 64 launched drugs that are documented as histamine H1 receptor antagonists. This relationship was placed in the context of passive diffusion (estimated using LogP, the octanol/water partition coefficient), receptor affinity, and the adjusted therapeutic daily dose, in order to account for side effect variability. Within this set, CNS permeability was not dependent on passive diffusion, as no significant differences were found for LogPand its pH‐corrected equivalent, LogD74. Sedation and orthostatic hypotension can be explained within the framework of ABCB1‐mediated efflux and adjusted dose, while target potency has less influence. ABCB1, an antitarget for anticancer agents, acts in fact as a drug target for nonsedating antihistamines. An empirical set of rules, based on the incidence of these two side effects, target affinity and dose was used to predict efflux effects for a number of drugs. Among them, azelastine and mizolastine are predicted to be effluxed via ABCB1‐mediated transport, whereas aripiprazole, clozapine, cyproheptadine, iloperidone, olanzapine, and ziprasidone are likely to be noneffluxed.
Long‐term energy production of III–V triple‐junction solar cells on the Martian surface
Authors: Hoheisel R. , Philipps S. P. , Bett A. W.
Published: January 2010

Based on theoretical considerations, optimum triple‐junction bandgap combinations are determined in order to achieve highest electrical energy production for a mission on the Martian surface. The solar cell structures analysed in this contribution are based on the GayIn1–yP, GaxIn1–xAs and Ge material system. A comparison of theoretical and already realised triple‐junction solar cell structures is presented. For the evaluation of long‐term electrical energy production, different geographic and climatic Martian scenarios are considered. Copyright © 2010 John Wiley & Sons, Ltd.
Detection of the voltage distribution in photovoltaic modules by electroluminescence imaging
Authors: Potthoff Torben , Bothe Karsten , Eitner Ulrich , Hinken David , Köntges Marc
Published: January 2010

We introduce an approach to determine the operating voltage of individual solar cells in photovoltaic (PV) modules by electroluminescence (EL) imaging. The highest EL signal of each solar cell is proportional to its operating voltage. Moreover the sum of all operating voltages equals the externally applied module voltage. Thus the operating voltage of individual solar cells is determined from the measured EL signal. The reliability of this relation is verified by measurements on specially prepared PV modules allowing us to measure the individual operating cell voltage. The experimentally measured cell voltages are deduced with an uncertainty of ±1% from an EL image.

Moreover, the operating cell voltages determined from the EL image are used to calculate the module series resistance. Comparing experimentally determined values from the operating cell voltage and the total current flowing supplied to the module with calculated module series resistances using tabulated material and typical solar cell parameters, a very good correspondence is found. Copyright © 2010 John Wiley & Sons, Ltd.
Six‐element circuit for maximum power point tracking in photovoltaic‐motor systems with variable‐frequency drives
Authors: Driemeier C. , Zilles R.
Published: January 2010

A low‐cost circuit was developed for stable and efficient maximum power point (MPP) tracking in autonomous photovoltaic‐motor systems with variable‐frequency drives (VFDs). The circuit is made of two resistors, two capacitors, and two Zener diodes. Its input is the photovoltaic (PV) array voltage and its output feeds the proportional‐integral‐derivative (PID) controller usually integrated into the drive. The steady‐state frequency–voltage oscillations induced by the circuit were treated in a simplified mathematical model, which was validated by widely characterizing a PV‐powered centrifugal pump. General procedures for circuit and controller tuning were recommended based on model equations. The tracking circuit presented here is widely applicable to PV‐motor system with VFDs, offering an efficient open‐access technology of unique simplicity. Copyright © 2010 John Wiley & Sons, Ltd.
Effects of using multi‐component electrolytes on the stability and properties of solar cells sensitized with simple organic dyes
Authors: Giannouli M. , Syrrokostas G. , Yianoulis P.
Published: January 2010

In this paper we present experimental results for electrochemical (dye‐sensitized) solar cells that were prepared in our laboratory in order to examine some of the major factors affecting the efficiency and the stability of such cells. Nanostructured TiO2 thin films were prepared and sensitized using an organic dye. For the purpose of this study three different types of electrolytes were developed: a standard‐type electrolyte containing potassium iodide and iodine in propylene carbonate (PC) and two novel, multi‐component electrolytes containing potassium iodide and iodine dissolved in varying mixtures of PC and EG (ethylene glycol). It was demonstrated that the combined properties of the two solvents in the multi‐component electrolytes enhance the efficiency and improve considerably the stability of the cells. Copyright © 2010 John Wiley & Sons, Ltd.
Efficiency (>15%) for thin‐film epitaxial silicon solar cells on 70 cm2 area offspec silicon substrate using porous silicon segmented mirrors
Authors: Kuzma‐Filipek I. , Nieuwenhuysen K.V. , Hoeymissen J.V. , Payo M.R. , Kerschaver E.V. , Poortmans J. , Mertens R. , Beaucarne G. , Schmich E. , Lindekugel S. , Reber S.
Published: January 2010

We report on the beneficial use of embedded segmented porous silicon broad‐band optical reflectors for thin‐film epitaxial silicon solar cells. These reflectors are formed by gradual increase of the spatial period between the layer segments, allowing for an enhanced absorption of low energy photons in the epitaxial layer. By combining these reflectors with well‐established solar cell processing by photolithography, a conversion efficiency of 15·2% was reached on 73 cm2 area, highly doped offspec multicrystalline silicon substrates. The corresponding photogenerated current densities (Jsc) were well above 31 mA/cm2 for an active layer of only 20 µm. Copyright © 2010 John Wiley & Sons, Ltd.
Comparative proteomics of human embryonic stem cells and embryonal carcinoma cells
Authors: Chaerkady Raghothama , Kerr Candace L. , Kandasamy Kumaran , Marimuthu Arivusudar , Gearhart John D. , Pandey Akhilesh
Published: January 2010

Pluripotent human embryonic stem cells (ESCs) can be differentiated in vitro into a variety of cells which hold promise for transplantation therapy. Human embryonal carcinoma cells (ECCs), stem cells of human teratocarcinomas, are considered a close but malignant counterpart to human ESCs. In this study, a comprehensive quantitative proteomic analysis of ESCs and ECCs was carried out using the iTRAQ method. Using two‐dimensional LC and MS/MS analyses, we identified and quantitated ∼1800 proteins. Among these are proteins associated with pluripotency and development as well as tight junction signaling and TGFβ receptor pathway. Nearly ∼200 proteins exhibit more than twofold difference in abundance between ESCs and ECCs. Examples of early developmental markers high in ESCs include β‐galactoside‐binding lectin, undifferentiated embryonic cell transcription factor‐1, DNA cytosine methyltransferase 3β isoform‐B, melanoma antigen family‐A4, and interferon‐induced transmembrane protein‐1. In contrast, CD99‐antigen (CD99), growth differentiation factor‐3, cellular retinoic acid binding protein‐2, and developmental pluripotency associated‐4 were among the highly expressed proteins in ECCs. Several proteins that were highly expressed in ECCs such as heat shock 27 kDa protein‐1, mitogen‐activated protein kinase kinase‐1, nuclear factor of κ light polypeptide gene enhancer in B‐cells inhibitor like‐2, and S100 calcium‐binding protein‐A4 have also been attributed to malignancy in other systems. Importantly, immunocytochemistry was used to validate the proteomic analyses for a subset of the proteins. In summary, this is the first large‐scale quantitative proteomic study of human ESCs and ECCs, which provides critical information about the regulators of these two closely related, but developmentally distinct, stem cells.
An integrated proteomics and transcriptomics reference data set provides new insights into the Bradyrhizobium japonicum bacteroid metabolism in soybean root nodules
Authors: Delmotte Nathanaël , Ahrens Christian H. , Knief Claudia , Qeli Ermir , Koch Marion , Fischer Hans‐Martin , Vorholt Julia A. , Hennecke Hauke , Pessi Gabriella
Published: January 2010

Bradyrhizobium japonicum, a gram‐negative soil bacterium that establishes an N2‐fixing symbiosis with its legume host soybean (Glycine max), has been used as a symbiosis model system. Using a sensitive geLC‐MS/MS proteomics approach, we report the identification of 2315 B. japonicum strain USDA110 proteins (27.8% of the theoretical proteome) that are expressed 21 days post infection in symbiosis with soybean cultivated in growth chambers, substantially expanding the previously known symbiosis proteome. Integration of transcriptomics data generated under the same conditions (2780 expressed genes) allowed us to compile a comprehensive expression profile of B. japonicum during soybean symbiosis, which comprises 3587 genes/proteins (43% of the predicted B. japonicum genes/proteins). Analysis of this data set revealed both the biases and the complementarity of these global profiling technologies. A functional classification and pathway analysis showed that most of the proteins involved in carbon and nitrogen metabolism are expressed, including a complete set of tricarboxylic acid cycle enzymes, several gluconeogenesis and pentose phosphate pathway enzymes, as well as several proteins that were previously not considered to be present during symbiosis. Congruent results were obtained for B. japonicum bacteroids harvested from soybeans grown under field conditions.
Substituent effect on the UV spectra of p‐disubstituted compounds XPh(CHCHPh)nY (n = 0, 1, 2)
Authors: Chen Guanfan , Cao Chenzhong
Published: January 2010

Three parameters, ${\rm \sigma }_{\rm CC}^{\rm ex} $, ${\rm \sigma }_{\rm CC}^{\rm ex} ({\rm XY)}$ and $\upsilon_{{\rm max,}\,{\rm parent}} $, are developed to express the substituent effect and the effect of the parent molecular structure of p‐disubstituted compounds XPh(CHCHPh)nY (n = 0, 1, 2). The investigated result shows a good correlation between the UV absorption wavenumbers (υmax) and the three parameters for a diverse set of title compounds, and the correlation equation can be used to predict the UV absorption energy of compounds with the mentioned structure. This approach provides a new insight for the quantitative structure‐property relationship (QSPR) correlation of the UV absorption energy of p‐disubstituted homologues. Copyright © 2010 John Wiley & Sons, Ltd.
Relationship between ground ice and solifluction: Field measurements in the Daisetsu Mountains, northern Japan
Authors: Matsumoto Hotaka , Yamada Shuji , Hirakawa Kazuomi
Published: January 2010

Soil temperature, surface heave and downslope movements were monitored continuously for one year (1998–99) within a solifluction lobe developed on seasonally frozen ground in the Daisetsu Mountains, northern Japan. Observations were also made of soil moisture and ice segregation. Seasonal freeze‐thaw cycles produced both frost creep and gelifluction. In layers shallower than 60 cm, ice segregation during the freezing season induced seasonal frost heave, and ice melt at the same depths during the thaw season promoted gelifluction as well as seasonal frost creep. At greater depths, gelifluction did not occur even when the thaw plane reached the ice‐rich layers. The results at the study site demonstrate that segregated ice plays an important role in gelifluction, but only at shallower depths. Copyright © 2010 John Wiley & Sons, Ltd.
Soil organic carbon pools in a periglacial landscape: a case study from the central Canadian Arctic
Authors: Hugelius Gustaf , Kuhry Peter , Tarnocai Charles , Virtanen Tarmo
Published: January 2010

We investigated total storage and landscape partitioning of soil organic carbon (SOC) in continuous permafrost terrain, central Canadian Arctic. The study is based on soil chemical analyses of pedons sampled to 1‐m depth at 35 individual sites along three transects. Radiocarbon dating of cryoturbated soil pockets, basal peat and fossil wood shows that cryoturbation processes have been occurring since the Middle Holocene and that peat deposits started to accumulate in a forest‐tundra environment where spruce was present (∼6000 cal yrs BP). Detailed partitioning of SOC into surface organic horizons, cryoturbated soil pockets and non‐cryoturbated mineral soil horizons is calculated (with storage in active layer and permafrost calculated separately) and explored using principal component analysis. The detailed partitioning and mean storage of SOC in the landscape are estimated from transect vegetation inventories and a land cover classification based on a Landsat satellite image. Mean SOC storage in the 0–100‐cm depth interval is 33.8 kg C m−2, of which 11.8 kg C m−2 is in permafrost. Fifty‐six per cent of the total SOC mass is stored in peatlands (mainly bogs), but cryoturbated soil pockets in Turbic Cryosols also contribute significantly (17%). Elemental C/N ratios indicate that this cryoturbated soil organic matter (SOM) decomposes more slowly than SOM in surface O‐horizons. Copyright © 2010 John Wiley & Sons, Ltd.
The temporal, social, spatial, and legal dimensions of return and onward migration
Authors: Jeffery Laura , Murison Jude
Published: January 2010

This special issue revisits key themes in the social science literature on transnationalism and mobility before addressing specific issues associated with return, circular, and onward migration arising from this special issue. We frame our discussion around the interconnected temporal, spatial, social, and legal dimensions explored by our contributors: the relationship between migration, generation, and stage in the life cycle; the implications of changing responsibilities to kin in the home and host countries; the notion of returning ‘home’ or to the ‘homeland’; and the relationship between citizenship, documentation, and (national) identification. Copyright © 2010 John Wiley & Sons, Ltd.
Gardenia jasminoides inhibits tumor necrosis factor‐alpha‐induced vascular inflammation in endothelial cells
Authors: Hwang Sun Mi , Lee Yun Jung , Yoon Jung Joo , Lee So Min , Kang Dae Gill , Lee Ho Sub
Published: January 2010

Inflammatory mediators such as tumor necrosis factor‐alpha (TNF‐α) enhance binding of low‐density lipoprotein to endothelium and upregulate the expression of endothelial leukocyte adhesion molecules during atherogenesis. The present study examined the effect of ethanol extract of Gardenia jasminoides (EGJ) on vascular inflammation in primary cultured human umbilical vein endothelial cells (HUVEC). TNF‐α‐induced the expression of vascular cell adhesion molecule‐1 (VCAM‐1) and endothelial cell‐selectin (E‐selectin) expression was inhibited in HUVEC pretreated with EGJ. In a functional study, EGJ dose‐dependently attenuated adhesion of HL‐60 monocytes to endothelial monolayers. A further analysis indicated that EGJ attenuated TNF‐α‐induced nuclear p65 nuclear factor‐kappa B (NF‐κB) translocation, suggesting that EGJ primarily affects the TNF‐α‐induced NF‐κB signaling pathway. Taken together, we provided here the first evidence showing that EGJ is able to inhibit TNF‐α‐induced NF‐κB activation, adhesion molecule expression, and monocyte‐endothelial interaction, suggesting an anti‐inflammatory role of EGJ, which may be useful in preventing vascular diseases, such as atherosclerosis. Copyright © 2010 John Wiley & Sons, Ltd.
Polarimetric signatures and hydrometeor classification of West African squall lines
Authors: Evaristo Raquel , Scialom Georges , Viltard Nicolas , Lemaître Yvon
Published: January 2010

During the AMMA campaign, the Doppler and polarimetric radar Ronsard was deployed in Kopargo, Benin. In the present paper, three squall lines sampled during that period are described. It was the first time this type of system had been observed with a polarimetric radar in the West African region. The strongest case occurred on 28 July 2006, and the others on 12 September and 30 June. The polarimetric characteristics of these systems are described and a hydrometeor classification algorithm is applied in order to identify the microphysics of the systems. Finally, the 3D wind field is retrieved for the 28 July event. The convective part of the squall lines is generally characterized by maxima of reflectivity, differential reflectivity (ZDR), and specific differential phase (KDP). The results of the hydrometeor classification show that the convective region is composed of strong (>30 mm h−1) to moderate rain (5–30 mm h−1) below the melting level, and graupel above. This zone seems to be characterized by relatively strong updraughts (5–10 m s−1), responsible both for the formation of graupel by riming and for the growth of drops due to coalescence. To the rear the systems are characterized by light rain (<5 mm h−1) below and snow or ice crystals above. These regions present downward flow below the melting layer, which prevents drop growth by condensation, consistent with the light rain observed. The stratiform part of these systems can be very non‐uniform, due to the presence of old cells dissipating, associated with moderate rain and thus stronger reflectivities. Copyright © 2010 Royal Meteorological Society
The influence of riparian shade on lowland stream water temperatures in southern England and their viability for brown trout
Authors: Broadmeadow S. B. , Jones J. G. , Langford T. E. L. , Shaw P. J. , Nisbet T. R.
Published: January 2010

Suitable thermal conditions in streams are necessary for fish and predictions of future climate changes infer that water temperatures may regularly exceed tolerable ranges for key species. Riparian woodland is considered as a possible management tool for moderating future thermal conditions in streams for the benefit of fish communities. The spatial and temporal variation of stream water temperature was therefore investigated over 3 years in lowland rivers in the New Forest (southern England) to establish the suitability of the thermal regime for fish in relation to riparian shade in a warm water system. Riparian shade was found to have a marked influence on stream water temperature, particularly in terms of moderating diel temperature variation and limiting the number of days per year that maximum temperatures exceeded published thermal thresholds for brown trout. Expansion of riparian woodland offers potential to prevent water temperature exceeding incipient lethal limits for brown trout and other fish species. A relatively low level of shade (20–40%) was found to be effective in keeping summer temperatures below the incipient lethal limit for brown trout, butca. 80% shade generally prevented water temperatures exceeding the range reported for optimum growth of brown trout. Higher levels of shade are likely to be necessary to protect temperature‐sensitive species from climate warming. © Crown copyright 2010.
Isocyanate‐free Route to Starch‐graft‐Polycaprolactone via Carbonyldiimidazole (CDI)‐mediated End Group Conversion
Authors: Najemi Loubna , Jeanmaire Thomas , Zerroukhi Amar , Raihane Mustapha
Published: January 2010

This paper reports on the synthesis of biodegradable starch‐graft‐poly ϵ‐caprolactone (starch‐g‐PCL) in two steps. First, poly ϵ‐caprolactone (PCL) was modified on the terminal groups by using carbodiimidazole (CDI) as coupling agent. Then, the starch graft copolymers with PCL were prepared through a carbonate bond using carboimidazole function. Monofunctional and bifunctional reactive end‐group PCL terminated with carboimidazole groups were prepared and reacted with hydroxyl groups of starch. The resulting starch‐g‐PCL copolymers were characterized by FT‐IR, NMR, HR‐MAS‐NMR, DSC, MEB and XRD.
Synthesis of Octenyl Succinic Derivative of Mechanically Activated Indica Rice Starch
Authors: Zhang Zhengmao , Zhao Siming , Xiong Shanbai
Published: January 2010

Indica rice starch was mechanically activated by ball milling and then esterified by octenyl succinic anhydride (OSA) in aqueous slurry systems. The process of esterification was studied with respect to the time of mechanical activation, OSA/starch ratio, temperature, pH, starch slurry concentration and reaction time. The effects of these reaction conditions were evaluated on the basis of degree of substitution (DS) and reaction efficiency (RE). The results indicated that mechanical activation could enhance the reaction of OSA and starch. The DS and RE of OSA starch increased sharply when the time of mechanical activation increased from 0 h to 10 h, after which it was not significantly affected until 50h. The suitable conditions for the synthesis of OSA starch from Indica rice starch that was mechanically activated for 10 h (MAIS10) were an OSA/starch ratio 3%, temperature 35°C, pH 8.5, starch slurry concentration 12.5% and reaction time 3h. For native Indica rice starch (NIS), all conditions were identical to MAIS10 except for the starch slurry concentration of 40% and reaction time of 4 h. The maximum DS and RE of OSA‐MAIS10 (0.02037, 88.03%) was higher than that of OSA‐NIS (0.01700, 73.46%) at OSA/starch ratio 3%. The esterification of MAIS10 with OSA showed a low sensitivity to pH and a higher stability than OSA‐NIS. Scanning electron microscopy (SEM) revealed that the modified OSA starches did not show any detectable change in the morphological structural characteristics. The esterification between OSA and starch was confirmed by Fourier transform infrared (FT‐IR) spectroscopy.
Use of Rigid Nephroscope for Laparoscopic Common Bile Duct Exploration—A Single‐Center Experience
Authors: Khan Muneer , Qadri Syed Javid Farooq , Nazir Syed Sajad
Published: January 2010

Background

Increasingly, laparoscopic biliary surgeons are undertaking laparoscopic cholecystectomy and laparoscopic common bile duct exploration for patients with cholelithiasis and choledocholithiasis. In laparoscopic common bile duct exploration a flexible choledochoscope is ordinarily used, and with this instrument the surgeon usually fails to remove large impacted stones. In contrast with use of a rigid nephroscope it is possible to remove all common bile duct stones irrespective of size and degree of impaction. The present study evaluates the efficiency of rigid nephroscope for managing common bile duct stones laparoscopically.

Methods

In the present study laparoscopic common bile duct exploration for stones was performed in 80 patients via standard laparoscopic cholecystectomy port sites. Patients with a common bile duct diameter >10 mm were included in this study. The rigid nephroscope was passed through the epigastric port and negotiated into the common bile duct through a choledochotomy. Stones were removed with graspers. Large hard stones were fragmented by pneumatic lithotripsy.

Results

Of the 80 patients treated in this manner, 72 (90%) had multiple common bile duct calculi, and 8 (10%) had a solitary common bile duct calculus. Mean common bile duct diameter was 15.3 mm (range: 10–37 mm). Conversion to open common bile duct exploration was necessary in 1 case (1.25%) because of difficult dissection secondary to extensive dense adhesions. In 7 patients (8.75%) a pneumatic lithotripter was used to fragment stones. Choledochotomy was managed by placing a T‐tube in 21 (26.25%) patients, by effecting primary closure in 58 (72.5%) patients, and by choledochoduodenostomy in 1 (1.25%) patient. The mean operative time in this series was 83 min (range: 53–135 min). The mean postoperative hospital stay was 4.2 days (range: 3–19 days). One patient (1.25%) developed cholangitis 5 months after laparoscopic common bile duct exploration; the cause was a residual common bile duct stone.

Conclusions

A rigid nephroscope can be used for managing all types of common bile duct calculi irrespective of site, size, composition, or degree of impaction. Its use can be expected to become the standard for laparoscopic common bile duct exploration, especially for removing large calculi from a dilated common bile duct.
Weight Difference Between Double Parathyroid Adenomas Is the Cause of False‐positive IOPTH Test After Resection of the First Lesion
Authors: Sitges‐Serra Antonio , Díaz‐Aguirregoitia Francisco Javier , de la Quintana Aitor , Gil‐Sánchez Jesús , Jimeno Jaime , Prieto Rosa , Sancho Joan J.
Published: January 2010

Background

Some patients with double parathyroid adenoma show a greater than 50% decline in intraoperative parathyroid hormone (IOPTH) after resection of the first lesion. The present study was designed to test the hypothesis that significant adenoma weight differences may explain this inappropriate decline of IOPTH.

Methods

We reviewed prospective database records at two tertiary institutions. Patients with a histopathologic diagnosis of double adenoma and no familial history of hyperparathyroidism were included. Diagnosis of double adenoma was confirmed either preoperatively (double uptake), intraoperatively (bilateral exploration), or at reintervention. IOPTH was determined following the Miami protocol. The 10‐min postexcision sample was considered as the 0‐min sample for IOPTH determinations at the time of resection of the second lesion.

Results

Thirteen patients met the inclusion criteria. After resection of the first lesion, IOPTH failed to decline in four patients and a second adenoma was removed. They had similar weight (404 vs. 598 mg). In nine patients IOPTH showed a false greater than 50% decline. These patients had the largest adenoma removed first (846 ± 226 mg), and only two had normal PTH serum concentrations 10 min after resection. The second adenoma was always smaller (284 ± 177 mg; P = 0.02) and its resection either during the same operation (7 cases) or at reoperation (2 cases) led to normalization of IOPTH at 10 min in all cases.

Conclusions

Two‐thirds of patients with double parathyroid adenoma show a false‐positive decline of IOPTH after resection of the first adenoma. This appears to be due to the initial removal of the larger lesion.
Mouse models for nuclear DNA‐encoded mitochondrial complex I deficiency
Authors: Koene Saskia , Willems Peter H. G. M. , Roestenberg Peggy , Koopman Werner J. H. , Smeitink Jan A. M.
Published: January 2010

Mitochondrial diseases are a group of heterogeneous pathologies with decreased cellular energy production as a common denominator. Defects in the oxidative phosphorylation (OXPHOS) system, the most frequent one in humans being isolated complex I deficiency (OMIM 252010), underlie this disturbed‐energy generation. As biogenesis of OXPHOS complexes is under dual genetic control, with complex II being the sole exception, mutations in both nuclear DNA (nDNA) and mitochondrial DNA (mtDNA) are found. Increasing knowledge is becoming available with respect to the pathophysiology and cellular consequences of OXPHOS dysfunction. This aids the rational design of new treatment strategies. Recently, the first successful treatment trials were carried out in patient‐derived cell lines. In these studies chemical compounds were used that target cellular aberrations induced by complex I dysfunction. Before the field of human clinical trials is entered, it is necessary to study the effects of these compounds with respect to toxicity, pharmacokinetics and therapeutic potential in suitable animal models. Here, we discuss two recent mouse models for nDNA‐encoded complex I deficiency and their tissue‐specific knock‐outs.
DGAT1, DGAT2 and PDAT Expression in Seeds and Other Tissues of Epoxy and Hydroxy Fatty Acid Accumulating Plants
Authors: Li Runzhi , Yu Keshun , Hildebrand David F.
Published: January 2010

Triacylglycerol (TAG) is the main storage lipid in plants. Acyl‐CoA: diacylglycerol acyltransferase (DGAT1 and DGAT2) and phospholipid: diacylglycerol acyltransferase (PDAT) can catalyze TAG synthesis. It is unclear how these three independent genes are regulated in developing seeds, and particularly if they have specific functions in the high accumulation of unusual fatty acids in seed oil. The expression patterns of DGAT1, DGAT2 and a PDAT in relation to the accumulation of oil and epoxy and hydroxy fatty acids in developing seeds of the plant species Vernonia galamensis, Euphorbia lagascae, Stokesia laevis and castor that accumulate high levels of these fatty acids in comparison with soybean and Arabidopsis were investigated. The expression patterns of DGAT1, DGAT2 and the PDAT are consistent with all three enzymes playing a role in the high epoxy or hydroxy fatty acid accumulation in developing seeds of these plants. PDAT and DGAT2 transcript levels are present at much higher levels in developing seeds of epoxy and hydroxy fatty acid accumulating plants than in soybeans or Arabidopsis. Moreover, PDAT,DGAT1 and DGAT2 are found to be expressed in many different plant tissues, suggesting that these enzymes may have other roles in addition to seed oil accumulation. DGAT1 appears to be a major enzyme for seed oil accumulation at least in Arabidopsis and soybeans. For the epoxy and hydroxy fatty acid accumulating plants, DGAT2 and PDAT also show expression patterns consistent with a role in the selective accumulation of these unusual fatty acids in seed oil.
The 2007 General Elections in Nigeria: An Account of the Politics of Personal Rule in an African Country by a former Presidential Aide
Authors: Okolie Andrew C.
Published: January 2010

This article is an insider's account of the vicious political struggles that shaped the April 2007 general elections in Nigeria which were adjudged to be fraudulent. It argues that the form of political struggles that gave rise that election derive from the enthronement of a particularly vicious and violent form of personal rule which is itself a product of Nigeria's colonial rule and long history of military dictatorship which saw to the concentration of power and resources in the state in the context of the existence of a weak bourgeois class and generalized poverty for the generality of the population. The intrigues and power struggles in Nigeria during its 4th Republic 1999–2007, particularly the power struggle between the country's President and his deputy are discussed to illustrate the character of Nigerian (and perhaps African) politics. Some suggestions are offered for a more just and stable Nigerian polity.
MiRNA‐26b regulates the expression of cyclooxygenase‐2 in desferrioxamine‐treated CNE cells
Authors: Ji Yanhong , He Yonghong , Liu Le , Zhong Xingyuan
Published: January 2010

Here we report that miR‐26b is involved in COX‐2 overexpression in desferrioxamine (DFOM)‐treated carcinoma of nasopharyngeal epithelial (CNE) cells. The level of miR‐26b in DFOM‐treated CNE cells is inversely proportional to the expression level of the COX‐2 protein. Overexpression of miR‐26b in DFOM‐treated CNE cells inhibits cell proliferation. A luciferase reporter gene experiment suggests that the 3′ untranslated region of COX‐2 carries a binding site for miR‐26b. Overexpression of miR‐26b marginally reduces the levels of COX‐2 protein in DFOM‐treated CNE cells. Moreover, knockdown of COX‐2 expression had a similar effect to overexpression of miR‐26b. Taken together, these results suggest that miR‐26b regulates COX‐2 expression in DFOM‐treated cells.