bluuebunny/crossref_metadata_2025 huggingface dataset:
Density‐Dependent Formation of the Pure trans‐Isomer of the Unsaturated Alcohol by Selective Hydrogenation of Citral in Supercritical Carbon Dioxide
Authors: Chatterjee M. , Ikushima Y. , Yokoyama T. , Sato M.
Published: February 2008

Selective hydrogenation of citral to unsaturated alcohol [geraniol (trans) + nerol (cis)] was carried out in supercritical carbon dioxide (scCO2) using an MCM‐41 supported plantinum catalyst (∼1  wt% Pt). A remarkable rate of isomerization of the unsaturated alcohol [nerol (cis) to geraniol (trans)] during the hydrogenation of citral was achieved simply by tuning the density of CO2. Optimum reaction conditions were developed to obtain only geraniol (trans) with a selectivity of 98.8% and citral conversion of 99.8%. A significant change in the cis:trans ratio of the product (1:82.3) from the substrate (1:1.3) was observed depending on the various reaction parameters like carbon dioxide and hydrogen pressure, reactant concentration, reaction time and, particularly, the total selectivity for unsaturated alcohol [geraniol (trans) +nerol (cis)]. It has been observed that the presence of hydrogen is necessary for isomerization. Our results were explained in terms of a density‐dependent, two‐step model. The kinetic behaviour shows that the rate of isomerization was higher in scCO2 compared to other organic solvents and the pure form of geraniol (trans) was obtained exclusively. A probable reaction pathway was proposed in order to explain the isomerization during hydrogenation of citral in scCO2 medium.
A systematic approach for modeling chromatographic processes—Application to protein purification
Authors: Chan Sharon , Titchener‐Hooker Nigel , Bracewell Daniel G. , Sørensen Eva
Published: February 2008

In this article, a systematic approach is presented which allows the estimation of model parameters including isotherm parameters for equilibrium‐dispersive and general rate models including a procedure for how to subsequently select the most appropriate isotherm and model for a given application. The approach consists of three parts: determination of feed concentration, parameter estimation, and model selection. Accurate modeling of any separation process depends on the starting point, i.e. the feed and the feed concentration, however, for many chromatographic separations, this concentration is unknown. The first part of this work therefore presents a systematic procedure for feed concentration determination. The estimation of isotherm or other model parameters is done using the simulation and optimization tool gPROMS. Finally, the predictions from each model alternative are then compared using fractionation and maximum purification diagrams. The estimation approach is successfully applied to three case studies, including purification of alcohol dehydrogenase from a yeast homogenate supernatant and gradient elution ion‐exchange of myoglobin, which illustrate the approach and the relative suitability and range of application of the models in describing the behavior of complex chromatographic separations. It is found that, while the equilibrium‐dispersive model is a good approximation in most cases, there are cases when the more detailed general rate model is required. © 2008 American Institute of Chemical Engineers AIChE J, 2008
Rye flour allergens: An emerging role in baker's asthma
Authors: Letrán Antonio , Palacín Arantxa , Barranco Pilar , Salcedo Gabriel , Pascual Cristina , Quirce Santiago
Published: February 2008

Background

Exposure to wheat flour is usually considered the most important cause of baker's asthma. However, other flours frequently used in bakeries may play an emerging role as relevant allergens causing occupational asthma.

Aims of study

We report on two cases of baker's asthma mainly caused by exposure to rye flour. The profile of allergen sensitization to cereal flour was investigated.

Methods

Two bakery workers suffering from rhinoconjunctivitis and asthma symptoms at work underwent an in vivo study (skin prick tests and bronchial allergen challenge) and in vitro study (total serum IgE, specific serum IgE and immunoblotting).

Results

Specific inhalation challenge with wheat flour did not elicit an asthmatic reaction, however both patients showed an early asthmatic reaction with the rye flour challenge. Rye flour‐immunoblotting showed IgE‐binding bands around 12–15 kDa, that correspond to rye flour enzymatic inhibitors which were not present in the wheat flour immunoblot.

Conclusions

Both bakers had developed occupational asthma to rye flour (confirmed by specific inhalation challenge test). Rye flour allergens (enzymatic inhibitors) are important allergens that should be considered in the diagnosis of baker's asthma. Am. J. Ind. Med. 51:324–328, 2008. © 2008 Wiley‐Liss, Inc.
Molecular cytogenetic characterization of a unique and complex de novo 8p rearrangement
Authors: Cooke Susanna L. , Northup Jill K. , Champaige Neena L. , Zinser William , Edwards Paul A.W. , Lockhart Lillian H. , Velagaleti Gopalrao V.N.
Published: February 2008

Human chromosome 8p is prone to recurrent rearrangements with inv dup del(8p) being most common. Each of these recurrent rearrangements is associated with different clinical manifestations. Some of these recurrent rearrangements at 8p are mediated by an 8p submicroscopic paracentric inversion between the olfactory gene clusters present in one of the parents. However, recent reports have shown that some of the rearrangements are unique and complex and are mediated by other repetitive elements within 8p. Here, we report on a unique and complex 8p rearrangement with seizures as the major presenting feature in the patient. Extensive fluorescence in situ hybridization and microarray analyses with tiling path 8p array showed that the rearrangement is unique in that the 8p duplication is a direct tandem duplication and, unlike the more common inv dup del(8p), is not derived from parental submicroscopic inversion. Also unlike the inv dup del(8p), the phenotype in our case is milder with no central nervous system malformations or cardiac defects. © 2008 Wiley‐Liss, Inc.
Engineering extruded collagen fibers for biomedical applications
Authors: Zeugolis D. I. , Paul R. G. , Attenburrow G.
Published: February 2008

Extruded collagen fibers constitute a promising biomimetic scaffold for tissue engineering applications. In this study, we compared the structural, thermal, and mechanical properties of fibers produced from either NaCl or poly(ethylene glycol) with a number‐average molecular weight of 8000 (PEG 8K), the only two coagents that have been used in the fabrication process. As novel, we report the fabrication of fibers with properties similar to native or synthetic fibers using other coagents. NaCl derived fibers were characterized by higher thermal stability (p < 0.026), stress (p < 0.001), and modulus (p < 0.0025) values than PEG 8K, whereas the latter yielded more extendable fibers (p < 0.012). Poly(ethylene glycol)s with number‐average molecular weights of 200 and 1000 produced fibers with similar mechanical properties (p > 0.05) that were thinner (p < 0.033), stiffer (p < 0.022), and less extendable (p < 0.0002) than those of PEG 8K. Poly(vinyl alcohol) (PVA) with a number‐average average molecular weight of 9–10,000 and PEG 8K yielded fibers with similar diameters and stress‐at‐break values (p > 0.05); however, the poly(ethylene glycol) derived fibers were more extendable (p < 0.0003), whereas the PVA fibers were stiffer (p < 0.029). Gum‐arabic‐ and soluble‐starch‐derived fibers were of similar tensile strength, extendibility, and stiffness (p > 0.05). In this in vitro study, the thickest (p < 0.011) and the weakest (p < 0.0066) fibers were produced in the presence of sodium sulfate. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Transcriptional response of dermal fibroblasts in direct current electric fields
Authors: Jennings Jessica , Chen Dongquan , Feldman Dale
Published: February 2008

During the course of normal wound healing, fibroblasts at the wound edge are exposed to electric fields (EFs) ranging from 40 to 200 mV/mm. Various forms of EFs influence fibroblast migration, proliferation, and protein synthesis. Thus, EFs may contribute to fibroblast activation during wound repair. To elucidate the role of EFs during the normal progression of healing, this study compares gene expression in normal adult dermal fibroblasts exposed to a 100 mV/mm EF for 1 h to non‐stimulated controls. Significantly increased expression of 162 transcripts and decreased expression of 302 transcripts was detected using microarrays, with 126 transcripts above the level of 1.4‐fold increases or decreases compared to the controls. Above the level of twofold, only 11 genes were significantly increased or decreased compared to controls. Many of these significantly regulated genes are associated with wound repair through the processes of matrix production, cellular signaling, and growth. Activity within specific cellular signaling pathways is noted, including TGF‐β, G‐proteins, and inhibition of apoptosis. In addition, RT‐PCR analysis of the expression of KLF6, FN1, RGS2, and JMJD1C over continued stimulation and at different field strengths suggests that there are specific windows of field characteristics for maximum induction of these genes. EFs thus appear to have an important role in controlling fibroblast activity in the process of wound healing. Bioelectromagnetics 29:394–405, 2008. © 2008 Wiley‐Liss, Inc.
Attractin/mahogany protein expression in the rodent central nervous system
Authors: Nakadate Kazuhiko , Sakakibara Shin‐Ichi , Ueda Shuichi
Published: February 2008

Attractin/Mahogany protein (Atrn) is known to be involved in a number of physiological and neuropathological events. Although the ubiquitous distribution of atrn mRNA has been described in neurons, lack of detailed information concerning the cellular and subcellular localization of protein product is impeding understanding of the role of Atrn. The present study immunohistochemically examined distributions of Atrn in rat and mouse central nervous systems (CNSs) by using a novel antibody for Atrn. Atrn was intensely expressed in most neurons and dendrites of large neurons, such as cortical pyramidal neurons and cerebellar Purkinje neurons. Intense Atrn expression was also observed in the neuropil of gray matter in many regions of the CNS, such as the main and accessory olfactory bulb, cerebral cortex, caudate putamen, dorsal lateral geniculate nucleus, medial eminence, superior colliculus, hippocampus, dentate gyrus, and layers 1 and 2 of the spinal cord. Furthermore, we found that astrocytes, microglia, and ependymal cells also express Atrn protein. Immunoelectron microscopy showed the subcellular distribution of Atrn in the plasma membrane of cell soma, dendrites, and spines in neurons and in the cytoplasmic membrane of Golgi apparatus, endoplasmic reticulum, and mitochondria in neurons and glial cells. These findings indicate that Atrn is more widely expressed throughout the CNS than previously reported, and expression of Atrn by various cell types suggests that Atrn may serve multiple functions in the CNS. J. Comp. Neurol. 508:94–111, 2008. © 2008 Wiley‐Liss, Inc.
Visualizing glutamatergic cell bodies and synapses in Drosophila larval and adult CNS
Authors: Daniels Richard W. , Gelfand Maria V. , Collins Catherine A. , DiAntonio Aaron
Published: February 2008

Glutamate is the major excitatory neurotransmitter in the vertebrate central nervous system (CNS) and at Drosophila neuromuscular junctions (NMJs). Although glutamate is also used as a transmitter in the Drosophila CNS, there has been no systematic description of the central glutamatergic signaling system in the fly. With the recent cloning of the Drosophila vesicular glutamate transporter (DVGLUT), it is now possible to mark many, if not all, central glutamatergic neurons and synapses. Here we present the pattern of glutamatergic synapses and cell bodies in the late larval CNS and in the adult fly brain by using an anti‐DVGLUT antibody. We also introduce two new tools for studying the Drosophila glutamatergic system: a dvglut promoter fragment fused to Gal4 whose expression labels glutamatergic neurons and a green fluorescent protein (GFP)‐tagged DVGLUT transgene that localizes to synapses. In the larval CNS, we find synaptic DVGLUT immunoreactivity prominent in all brain lobe neuropil compartments except for the mushroom body. Likewise in the adult CNS, glutamatergic synapses are abundant throughout all major brain structures except the mushroom body. We also find that the larval ventral nerve cord neuropil is rich in glutamatergic synapses, which are primarily located near the dorsal surface of the neuropil, segregated from the ventrally positioned cholinergic processes. This description of the glutamatergic system in Drosophila highlights the prevalence of glutamatergic neurons in the CNS and presents tools for future study and manipulation of glutamatergic transmission. J. Comp. Neurol. 508:131–152, 2008. © 2008 Wiley‐Liss, Inc.
Self‐Assembly of Triorganotin Complexes: Syntheses, Characterization, and Crystal Structures of Dinuclear, 1D Polymeric Chain, and 2D Network Polymers Containing Chiral (+)‐(1R,3S)‐Camphoric Acid and meso‐cis‐4‐Cyclohexene‐1,2‐dicarboxylic Acid Ligands
Authors: Ma Chunlin , Wang Qingfeng , Zhang Rufen
Published: February 2008

Eight new chiral triorganotin(IV) complexes, (R3Sn)2[C8H14(COO)2] (R = C6H5: 1; PhCH2: 2), {(R3Sn)2[C8H14(COO)2]}n(R = nBu: 3; Me: 4), (R3Sn)2[C6H8(COO)2] (R = C6H5: 5; PhCH2: 6), {(R3Sn)[C6H8(COO)2]}n (R = nBu: 7), and {(R3Sn)2[C8H14(COO)2]}n (R = Me: 8) have been synthesized by the reaction of (+)‐(1R,3S)‐camphoric acid and meso‐cis‐4‐cyclohexene‐1,2‐dicarboxylic acid with triorganotin(IV) chloride in the presence of sodium ethoxide. All of the complexes were characterized by elemental analysis, FT‐IR, NMR (1H, 13C and 119Sn) spectroscopy, and TGA. Except for 2, 5, and 6, all of the complexes were also characterized by X‐ray crystallography. Complex 1 has a dinuclear structure, and complex 3 has a 1D zigzag chain structure and forms a 3D organotin framework through weak intermolecular O···Sn interactions. Complex 7 also has a 1D zigzag chain structure in which meso‐cis‐4‐cyclohexene‐1,2‐dicarboxylic acid acts as a bidentate ligand coordinated to tri‐n‐butyltin(IV) ions. Complexes 4 and 8 have 2D network structures in which (+)‐camphoric acid and meso‐cis‐4‐cyclohexene‐1,2‐dicarboxylic acid act as tetradentate ligands coordinated to trimethyltin(IV) ions.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Fluorophobic Effect in Metallomesogens – The Synthesis and Mesomorphism of Ag, Au, Cu, Fe, Pd, and Pt Fluorous Isocyanide Complexes
Authors: Dembinski Roman , Espinet Pablo , Lentijo Sergio , Markowicz Marcin W. , Martín‐Alvarez Jose M. , Rheingold Arnold L. , Schmidt Daniel J. , Sniady Adam
Published: February 2008

The synthesis of Ag(CNAr)2BF4, Ag(CNAr)2NO3, AuCl(CNAr), CuCl(CNAr), [CuCl(CNAr)2]2, Fe(CO)4CNAr, trans‐[PdI2(CNAr)2], and trans‐[PtI2(CNAr)2] complexes containing the fluorous isocyanide ligand CNAr [Ar = 4‐F(CF2)8(CH2)4OC6H4] and the examination of the mesomorphic properties of these novel fluorous organometallics are reported. The fluorous isocyanide ligand is mesomorphic, as opposed to its hydrocarbon analogue. In general, the fluorophobic effect enhances the microsegregation in the investigated organometallic/isocyanide complexes, as compared to their hydrocarbon analogues. The fluorous mesophases are stable over a wider temperature range and exhibit higher transition temperatures.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Chemical Modification of a Bridging Ligand Inside a Metal–Organic Framework while Maintaining the 3D Structure
Authors: Costa José Sánchez , Gamez Patrick , Black Cory A. , Roubeau Olivier , Teat Simon J. , Reedijk Jan
Published: February 2008

A new metal–organic framework (MOF) with amino groups situated inside the pores has been synthesized. This MOF has been modified by post‐synthesis with two different functionalities. The crystal structures of the two functionalized MOFs clearly demonstrate that it is possible to transform the cavities of a MOF without modifying its original 3D structure. These unprecedented results open up tremendous possibilities in the field of MOF chemistry because many potential applications in the fields of catalysis, material science ornanochemistry can be envisaged when applying the reported synthetic pathway.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
External vs. Internal Interactions in the Enantiodiscrimination of Fluorinated α‐Amino Acid Derivatives by Heptakis[2,3‐di‐O‐acetyl‐6‐O‐(tert‐butyldimethylsilyl)]‐β‐cyclodextrin, a Powerful Chiral Solvating Agent for NMR Spectroscopy
Authors: Uccello‐Barretta Gloria , Balzano Federica , Pertici Francesca , Jicsinszky Laszlo , Sicoli Giuseppe , Schurig Volker
Published: February 2008

NMR spectroscopic investigations involving extensive use of ROESY and DOSY techniques and comparison withsilylated‐acetylated linear dextrins as acyclic model compounds shed light on the origin of the phenomenon ofenantiodiscrimination of fluorinated α‐amino acid derivatives by heptakis[2,3‐di‐O‐acetyl‐6‐O‐(tert‐butyldimethylsilyl)]‐β‐cyclodextrin. The effectiveness and versatility of the cyclic derivatized oligosaccharide as a chiral solvating agent for the NMR determination of enantiomeric purity in the same class of compounds is demonstrated. A regular correlation between the relative positions of enantiomers' signals and absolute configurations is observed. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Design of Amperometric Biosensors and Biofuel Cells by the Reconstitution of Electrically Contacted Enzyme Electrodes
Authors: Zayats Maya , Willner Bilha , Willner Itamar
Published: February 2008

The electrical contacting of redox enzymes with electrodes is the most fundamental requirement for the development of amperometric biosensors and biofuel cell elements. For the effective electrical communication of redox enzymes with electrodes the use of electron relay units that transport the electrons between the enzyme redox center and the conducting surface is essential. Also, the structural alignment of the redox enzyme units in respect to the electrode in a configuration where the enzyme redox center is in close proximity to the conductive surface is needed. The present report summarizes the reconstitution paradigm developed by our laboratory in the last decade as a versatile method to electrically contact redox enzymes with electrodes, and as a generic approach to develop amperometric biosensors and biofuel cell elements. The process is based on the reconstitution of the apo‐enzyme on a relay‐cofactor monolayer on thin film‐functionalized electrode. Different relay units were used to electrically communicate flavin adenine dinucleotide (FAD)‐containing enzymes (flavoenzymes) or pyrroloquinoline quinone (PQQ)‐containing enzymes with electrodes. This included molecular redox‐active relays, molecular redox‐active ‘shuttles’, redox‐active polymers (e.g., polyaniline), Au nanoparticles, and carbon nanotubes. The reconstitution of different apo‐enzymes on these relay‐cofactor‐functionalized electrodes led to unprecedented efficient electrical contacting between the redox centers of the enzymes and the electrodes. Besides very sensitive amperometric biosensors that emerged from this method, the resulting amperometric biosensors revealed high selectivity and specificity. A related approach to establish electrical contact between redox enzymes dependent on diffusional cofactors and electrodes and to develop an integrated bioelectrocatalytically active enzyme electrode was developed. The method involved assembly of a relay‐cofactor diad on the electrode, and the surface crosslinking of an affinity complex generated between the enzyme and the surface‐confined cofactor units. This method was successfully applied to electrically contact nicotinamide adenine dinucleotide (phosphate) NAD(P)+‐dependent enzymes and cytochrome c‐dependent enzymes. For example, enzyme‐modified electrodes for the bioelectrocatalyzed oxidation of alcohol, lactate and malate were fabricated by the electrical contacting of the respective NAD(P)+‐dependent dehydrogenases. Similarly, the bioelectrocatalytic reduction of O2 was accomplished by an integrated cytochrome c/cytochrome oxidase‐functionalized electrode. The electrically contacted enzyme electrodes were also used to develop noncompartmentalized biofuel cell elements. Biofuel cell elements consisting of electrically contacted reconstituted enzyme electrodes were constructed. Glucose or alcohol were used in these systems as fuel substrates and O2 as oxidizer.
Analysis of Bio‐Processes using Ion Mobility Spectrometry
Authors: Vautz W. , Baumbach J. I.
Published: February 2008

Bio‐processes are ruled by the metabolism of the involved microorganisms. During the process, the metabolism of these microorganisms changes their environment and as a consequence, the metabolites produced by the microorganisms will change too. Therefore, those metabolites can be used to characterize such processes. Many of the metabolites are volatile or semi‐volatile organic compounds which can be identified and quantified with high temporal resolution and sufficient sensitivity using ion mobility spectrometry. The potential of this method, especially when multi‐capillary‐columns are used for rapid pre‐separation, is illustrated on several representative and successful examples such as beer fermentation control, wine characterization, identification of fungi and bacteria as well as quantification of their metabolites as a measure for the growth of the culture. Those examples, representing recent work of the ion mobility spectrometry group at ISAS – Institute for Analytical Sciences in Dortmund, Germany, illustrate the potential of ion mobility spectrometry for bio‐process control, on one hand, and the existing challenges, on the other.
Biosensors and Eco‐toxicology
Authors: Hansen P.‐D.
Published: February 2008

Sensors and biosensors as well as ecotoxicological tools like bio‐analytical systems, bioassays and biomarkers provide us with detection systems for signaling a potential damage in the environment (environmental signaling). These responses of early recognition will prevent the eventual damage in the environmental matrices. Once an ecosystem damage has occurred, the remedial action processes for recovery could be expensive and pose certain logistical problems. Ideally, “early warning signals” in ecosystems using sensing systems (biosensors) and biochemical responses (biomarkers) as well as the classical effect‐related bioassays would not only tell us the initial levels of damage, but these signals will also provide us with answers for the development of control strategies and precautionary measures. In order to understand the complexity of the structure of populations and processes behind environmental health, our efforts have to be directed to promote rapid and cost‐effective new emerging parameters, such as effect‐related parameters like biochemical responses (biomarkers) in the field of immunotoxicity and endocrine disruption. Environmental effects, e.g. genotoxicity, were detected in organisms from various “hot spots“ and UV‐B exposed fish embryos. One problem is always to find the relevant interpretation and risk assessment tools for the environment in the context of the reference areas.
Current Stem Cell Technology: Limitations and Realistic Expectations
Authors: Kruse C. , Danner S. , Rapoport D. H.
Published: February 2008

The exploration of stem cells has always been strongly associated with the intent to advance more efficient tools for regenerative medicine, especially the repair of damaged tissue. To date, apart from very few working therapies, the success of this approach has been quite limited, and for clinical applications there are no immediate major breakthroughs in sight. Besides the known ethical and fundamental scientific issues, the reader should be pointed to a number of technical issues, that are believed to hamper the progress of applied stem cell research considerably: (i) The provision of a sufficient amount of stem cells with the propensity to differentiate into the desired cell type; (ii) The production of an ample amount of the desired cell type, which can afterwards effectively contribute to recover the impaired tissue; and (iii) The reliable exclusion of pathological side effects, like cancer generation or immunological host versus graft reactions. Here, the authors propose that some of these difficulties might be overcome by employing alternative stem cells, like adult stem cells from exocrine glands. Additionally, the authors suggest some novel uses of stem cells, which are not directly aimed at regenerative medicine and have received comparatively little attention, although they are readily available.
Solving the advection–dispersion equation with discontinuous Galerkin and multipoint flux approximation methods on unstructured meshes
Authors: Younes Anis , Ackerer Philippe
Published: February 2008

In this work, we develop a new model to solve the advection–dispersion transport equation on unstructured triangular meshes. The model combines numerical methods that are specifically suited to achieve high accuracy for each type of equation without using the time splitting procedure. It is based on a combination of the upwind discontinuous Galerkin (DG) method for advection and the multipoint flux approximation (MPFA) method for dispersion.

In contrast to mixed finite elements, MPFA methods provide fluxes at element interfaces explicitly by weighted sums of discrete element concentrations. Therefore, the combination of DG and MPFA methods allows taking into account total flux boundary conditions while using different numerical techniques.

A theta‐scheme time discretization is developed for advection and an implicit scheme for dispersion. Accuracy of the numerical model is shown by simulating (i) the transport of a tracer in a simplified bidimensional problem with highly unstructured mesh and (ii) a laboratory‐scale experiment with high viscosity contrasts. Copyright © 2008 John Wiley & Sons, Ltd.
Minerals provide tints and possible binder/extender in pigments in san rock paintings (South Africa)
Authors: Arocena Joselito M. , Hall Kevin , Meiklejohn Ian
Published: February 2008

Minerals such as iron oxides and clays provide high tinting strength and improve the adhesive properties of pigments. In this study, we investigated the mineral composition of pigments from samples of San rock art. We used X‐ray diffraction and scanning electron microscopy to determine the mineral composition and micromorphology of pigments. Results showed that the major minerals in pigments in San rock art are whewellite, quartz, gypsum, hematite, and various alumino‐silicate minerals. The red hue in the pigment is due to hematite; gypsum and clays provide the white coloration, whereas black might be due to amorphous manganese compounds. We believe that whewellite with globular habit was extracted from plant sap (e.g., aloe vera) and added to the pigment, perhaps as binder, extender, or whitener. Whewellite with needle‐shaped morphology was present in cracks that developed in pigments and indicated an early stage of deterioration of the rock art. We propose that conservationists should seriously evaluate any change in the environmental conditions at the art site (e.g., removal of vegetation to improve touristic view) because such changes might significantly increase thermal fluctuations in pigments and promote crack formation and hence the decay of the San rock art. © 2008 Wiley Periodicals, Inc.
Rainfall‐discharge relationships for a monsoonal climate in the Ethiopian highlands
Authors: Liu Ben M. , Collick Amy S. , Zeleke Gete , Adgo Enyew , Easton Zachary M. , Steenhuis Tammo S.
Published: February 2008

This study presents a simple rainfall‐discharge analysis for the Andit Tid, Anjeni, and Maybar watersheds of northern Ethiopia. The Soil Conservation Research Programme (SCRP) established monitoring stations in each of these sites during the 1980s, with climate and stream flow measurements being recorded up to the present. To show how these data could be used to provide insight into catchment‐level runoff mechanisms, simple linear relationships between effective precipitation and runoff are developed for each watershed, with the conclusion that all three watersheds exhibit consistent hydrologic behaviour after approximately 500 mm of cumulative effective seasonal rainfall has fallen since the beginning of season. After the 500 mm rainfall threshold is reached, approximately 50% of any further precipitation on these watersheds will directly contribute to catchment runoff. Copyright © 2008 John Wiley & Sons, Ltd.
Metastasis is promoted by a bioenergetic switch: New targets for progressive renal cell cancer
Authors: Langbein Sigrun , Frederiks Wilma M. , zur Hausen Axel , Popa Juljane , Lehmann Jan , Weiss Christel , Alken Peter , Coy Johannes F.
Published: February 2008

Targeted therapies have demonstrated clinical benefit with limited impact on long‐term disease specific survival in the treatment of renal cell cancer (RCC). New opportunities for the treatment of tumors that are resistant or have relapsed, are needed. Increased anaerobic glucose fermentation to lactate (aerobic glycolysis), leading to oxygen‐ and mitochondria‐independent ATP generation is a hallmark of aggressive cancer growth. This metabolic shift results in increased lactate production via cycling through the pentose phosphate pathway (PPP), and plays an important role in tumor immune escape, progression and resistance to immune‐, radiation‐ and chemo‐therapy. This study explored the activity and impact of the oxidative and nonoxidative branches of the PPP on RCC to evaluate new therapeutic options. Activity was determined in the oxidative branch by glucose‐6‐phosphate‐dehydrogenase (G6PD) activity, and in the nonoxidative branch by the total transketolase activity and the specific expression of the transketolase‐like‐1 (TKTL1) protein. Transketolase and G6PD activity were intensely elevated in tumor tissues. Transketolase, but not G6PD activity, was more elevated in metastasizing tumors and TKTL1 protein was significantly overexpressed in progressing tumors (p = 0.03). Lethal tumors, where surrogate parameters such as grading and staging had failed to predict progression, showed intensive TKTL1 protein expression. RCC was found to have activated oxidative and nonoxidative glucose metabolism through the PPP, displaying a bioenergetic shift toward nonoxidative glucose fermentation in progressing tumors. The coexistence of cancer cells with differentially regulated energy supplies provides new insights in carcinogenesis and novel anticancer targets. © 2008 Wiley‐Liss, Inc.
DCC promoter hypermethylation in esophageal squamous cell carcinoma
Authors: Lui Park Hannah , Sook Kim Myoung , Yamashita Keishi , Westra William , Lopes Carvalho Andre , Lee Juna , Jiang Wei‐Wen , Hyen Baek Jin , Liu Junwei , Osada Motonobu , Moon Chul‐So , Califano Joseph A. , Mori Masaki , Sidransky David
Published: February 2008

Deleted in Colorectal Cancer (DCC) is a putative tumor suppressor gene, whose loss has been implicated in colorectal tumorigenesis. Decreased or loss of DCC expression has been demonstrated in a number of human cancers, including esophageal cancer. In this study, we analyzed esophageal squamous cell carcinoma (ESCC) cell lines and primary ESCCs as well as normal esophageal tissues for DCC methylation by bisulfite sequencing, methylation‐specific PCR (MSP) and/or quantitative methylation‐specific PCR (qMSP). When a qMSP cut‐off value for positivity was set to 1.0, DCC methylation was detected in 10 of 12 ESCC cell lines tested, 74% of primary ESCCs (n = 70), 0% of corresponding normal esophageal tissues (n = 20) and 0% of normal esophagus from healthy individuals (n = 19). DCC expression was undetectable in the majority of ESCC cell lines, and treatment with the DNA methyltransferase inhibitor 5‐aza‐2′‐deoxycytidine reactivated gene expression. DCC overexpression suppressed colony formation in ESCC cell lines, suggesting that DCC may function as a tumor suppressor gene in the esophagus. However, DCC methylation was not associated with any clinical or pathologic parameters measured. We have demonstrated that DCC methylation is a frequent and cancer‐specific event in primary ESCCs, suggesting that DCC and associated pathways may represent a new diagnostical therapeutic target. © 2008 Wiley‐Liss, Inc.
An immunochromatographic assay to detect reduced level of laminin‐5 γ2 in sulfur mustard‐exposed normal human epidermal keratinocytes
Authors: Jin Xiannu , Ray Radharaman , Ray Prabhati
Published: February 2008

The need for reliable methods to detect the nature and extent of poisoning with chemical warfare agents is evident from the recent threat of use of these agents in warfare and terrorist attacks. Sulfur mustard (SM; 2,2′‐dichlorodiethyl sulfide) is an alkylating vesicant agent, which has been used as a chemical weapon in various conflicts during the 20th century. The injuries resulting from SM‐exposure are mainly characterized by epithelial damage of the tissues through which it is absorbed, i.e. skin, eye and the respiratory tract. Proteins in the skin mostly affected by SM‐exposure are laminin‐5 and integrin α6β4. Laminin‐5 constitutes the anchoring filaments and binds the transmembrane protein integrin α6β4. Recent studies have shown that SM alkylation causes a significant reduction of laminin‐5, disruption of α6β4 integrin and decreases the expression of integrin α6 and β4 subunits, therefore, leads to destabilization of dermal–epidermal attachments and potentiates vesication. This study established a unique immunochromatographic detection method (strip assay) to detect the degradation of laminin‐5 in SM‐exposed NHEK (normal human epidermal keratinocytes) extract. This method may serve as a rapid SM‐exposure diagnostic/screening procedure that could be applied directly to skin extracts of individuals who have supposedly been exposed to SM. Copyright © 2008 John Wiley & Sons, Ltd.
Posttraumatic growth in accident survivors: openness and optimism as predictors of its constructive or illusory sides
Authors: Zoellner Tanja , Rabe Sirko , Karl Anke , Maercker Andreas
Published: February 2008

Posttraumatic growth (PTG), the phenomenon of self‐reported positive outcomes of trauma, is assumed to consist of two sides: a constructive and an illusory side. This study investigates the relationship between PTG and its possible illusory and constructive predictors, as well as the moderating role of posttraumatic stress disorder (PTSD) severity. One‐hundred two motor vehicle accident (MVA) survivors with full, subsyndromal, and without PTSD were assessed by multiple psychometric measures targeting PTSD severity, posttraumatic growth, optimism, and openness to experience. Hierarchical regression analysis yielded differential interaction effects between PTSD severity and optimism, as well as openness facets pointing to the moderating role of PTSD severity in the prediction of an illusory and a constructive factor in PTG. © 2008 Wiley Periodicals, Inc. J Clin Psychol. 64: 245–263, 2008.
Therapist effects on outcome and alliance in inpatient psychotherapy
Authors: Dinger Ulrike , Strack Micha , Leichsenring Falk , Wilmers Fabian , Schauenburg Henning
Published: February 2008

As an addition to the ongoing discussion concerning the magnitude of therapist effects on outcome in psychotherapy, we investigated therapist variability in a large inpatient psychotherapy sample. We included global symptomatic outcome (Global Severity Index of the Symptom Checklist‐90 Revised [SCL‐90‐R]; German version, Franke, 1995) and alliance (Helping Alliance Questionnaire; German version, Bassler, Potratz & Krauthauser, 1995) ratings of 2554 inpatients who were treated by 50 psychotherapists. Multilevel regression analyses (HLM; Raudenbush, Bryk, Cheong, & Congdon, 2004) were used for analyses. Overall, therapists accounted for a much greater variability on alliance (33%) than on outcome (3%). Therapists were differentially effective with regard to their patients' symptom severity at the beginning of treatment, and therapists differed in the degree that a positive alliance was associated with therapeutic outcome. The relatively small therapist effect on outcome is attributed to compensatory mechanisms in the specific context of inpatient therapy. © 2008 Wiley Periodicals, Inc. J Clin Psychol 64: 344–354, 2008.
Responsibility, thought‐action fusion, and thought suppression in Turkish patients with obsessive–compulsive disorder
Authors: Yorulmaz O. , Karanci A.N , Bastug B. , Kisa C. , Goka E.
Published: February 2008

Although an inflated sense of responsibility, thought—action fusion, and thought suppression are influential factors in cognitive models of obsessive–compulsive disorder (OCD), their impact on OCD has generally been demonstrated in samples from Western countries. The aim of the present study is to evaluate these cognitive factors in Turkish patients with OCD, other anxiety disorders, and community controls. Group comparisons showed that responsibility based on self‐dangerousness and thought suppression significantly distinguished OCD patients from patients with other anxiety disorders and controls. Moreover, correlation and discriminant function analyses indicated that thought–action fusion in morality and likelihood was also associated with OCD symptoms. The present findings provide support for the international validity and specificity of cognitive factors and model for OCD. © 2008 Wiley Periodicals, Inc. J Clin Psychol 64: 308–317, 2008.
Hepatitis B virus–cell interactions and pathogenesis
Authors: Nguyen David H. , Ludgate Laurie , Hu Jianming
Published: February 2008

Like all viruses, hepatitis B virus (HBV) replication and pathogenesis depends on the critical interplay between viral and host factors. In this review, we will focus on the recent progress in understanding the virus–host interactions at the level of the infected cell. These interactions include the requirement of cellular chaperones for the initiation of HBV reverse transcription, the role of the HBV X protein (HBx) in modifying viral and cellular transcription and signaling, the formation of the HBV episomal DNA and its epigenetic regulation in viral persistence, and the cellular factors involved in viral entry, nucleocapsid maturation, and virion secretion. J. Cell. Physiol. 216: 289–294, 2008. © 2008 Wiley‐Liss, Inc.
Modulation of cellular proliferation and differentiation through GABAB receptors expressed by undifferentiated neural progenitor cells isolated from fetal mouse brain
Authors: Fukui Masaki , Nakamichi Noritaka , Yoneyama Masanori , Ozawa Shusuke , Fujimori Sayumi , Takahata Yoshifumi , Nakamura Nobuhiro , Taniura Hideo , Yoneda Yukio
Published: February 2008

In this study, we have attempted to evaluate the possible role of metabotropic GABAB receptors (GABABR) expressed by neural progenitor cells prepared from neocortex of embryonic Std‐ddY mice. Immunocytochemical analysis confirmed the validity of isolation procedures of neural progenitors, while round spheres were formed with clustered cells during culture with epidermal growth factor (EGF) for 10 days. A reverse transcription polymerase chain reaction analysis revealed constitutive expression of GABAAR, GABABR, and GABACR subtypes in undifferentiated progenitors and neurospheres formed within 10 days. Exposure to GABA led to concentration‐dependent increases in the total area and proliferation activity of neurospheres at 10–300 µM, while the GABABR agonist baclofen at 100 µM significantly increased the size of neurospheres expressing both GABABR1 and GABABR2 subunits in a manner sensitive to a GABABR antagonist. By contrast, a significant decrease was seen in the total areas of neurospheres prepared from mice deficient of the GABABR1 subunit. In neurospheres of GABABR1‐null mice, a significant increase was induced in the number of cells immunoreactive for a glial marker protein, with a concomitant decrease in that of a neuronal marker protein, upon spontaneous differentiation after the removal of EGF. These results suggest that GABABR may be functionally expressed by neural progenitor cells to preferentially promote the commitment toward a neuronal lineage after the activation of cellular proliferation toward self‐replication in the developing mouse brain. J. Cell. Physiol. 216: 507–519, 2008. © 2008 Wiley‐Liss, Inc.
The hyomandibulae of rhizodontids (Sarcopterygii, stem‐tetrapoda)
Authors: Brazeau Martin D. , Jeffery Jonathan E.
Published: February 2008

Despite its important role in the study of the evolution of tetrapods, the hyomandibular bone (the homologue of the stapes in crown‐group tetrapods) is known for only a few of the fish‐like members of the tetrapod stem‐group. The best‐known example, that of the tristichopterid Eusthenopteron, has been used as an exemplar of fish‐like stem‐tetrapod hyomandibula morphology, but in truth the conditions at the base of the tetrapod radiation remain obscure. We report, here, four hyomandibulae, from three separate localities, which are referable to the Rhizodontida, the most basal clade of stem‐tetrapods. These specimens share a number of characteristics, and are appreciably different from the small number of hyomandibulae reported for other fish‐like stem‐tetrapods. While it is unclear if these characteristics represent synapomorphies or symplesiomorphies, they highlight the morphological diversity of hyomandibulae within the early evolution of the tetrapod total‐group. Well‐preserved muscle scarring on some of these hyomandibulae permit more robust inferences of hyoid arch musculature in stem‐tetrapods. J. Morphol., 2008. © 2008 Wiley‐Liss, Inc.
Ultrastructure and function of the mastax in Dicranophorus forcipatus (Rotifera: Monogononta)
Authors: Riemann Ole , Ahlrichs Wilko H.
Published: February 2008

Rotifers are characterized by a complex set of cuticularized jaw elements in the pharynx. The fine structure of the jaw elements has been the subject of SEM studies for some time, but only very limited information exists on the ultrastructure of the jaw elements and their function beyond taxonomic considerations. Drawing on SEM and TEM techniques, the present study presents a detailed analysis of the mastax in Dicranophorus forcipatus, a carnivorous monogonont rotifer species from freshwater habitats characterized by an extrusible, grasping jaw apparatus. Based on ultrathin serial sections, the jaw elements are reconstructed and, in total, nine paired and two unpaired muscles identified. Possibly homologous muscles in other rotifer species are discussed and functional considerations of the forcipate mastax are suggested. J. Morphol., 2008. © 2008 Wiley‐Liss, Inc.
The Alzheimer's disease neuroimaging initiative (ADNI): MRI methods
Authors: Jack Clifford R. , Bernstein Matt A. , Fox Nick C. , Thompson Paul , Alexander Gene , Harvey Danielle , Borowski Bret , Britson Paula J. , L. Whitwell Jennifer , Ward Chadwick , Dale Anders M. , Felmlee Joel P. , Gunter Jeffrey L. , Hill Derek L.G. , Killiany Ron , Schuff Norbert , Fox‐Bosetti Sabrina , Lin Chen , Studholme Colin , DeCarli Charles S. , Gunnar Krueger  , Ward Heidi A. , Metzger Gregory J. , Scott Katherine T. , Mallozzi Richard , Blezek Daniel , Levy Joshua , Debbins Josef P. , Fleisher Adam S. , Albert Marilyn , Green Robert , Bartzokis George , Glover Gary , Mugler John , Weiner Michael W.
Published: February 2008

The Alzheimer's Disease Neuroimaging Initiative (ADNI) is a longitudinal multisite observational study of healthy elders, mild cognitive impairment (MCI), and Alzheimer's disease. Magnetic resonance imaging (MRI), (18F)‐fluorodeoxyglucose positron emission tomography (FDG PET), urine serum, and cerebrospinal fluid (CSF) biomarkers, as well as clinical/psychometric assessments are acquiredat multiple time points. All data will be cross‐linked and made available to the general scientific community. The purpose of this report is to describe the MRI methods employed in ADNI. The ADNI MRI core established specifications thatguided protocol development. A major effort was devoted toevaluating 3D T1‐weighted sequences for morphometric analyses. Several options for this sequence were optimized for the relevant manufacturer platforms and then compared in a reduced‐scale clinical trial. The protocol selected for the ADNI study includes: back‐to‐back 3D magnetization prepared rapid gradient echo (MP‐RAGE) scans; B1‐calibration scans when applicable; and an axial proton density‐T2 dual contrast (i.e., echo) fast spin echo/turbo spin echo (FSE/TSE) for pathology detection. ADNI MRI methods seek to maximize scientific utility while minimizing the burden placed on participants. The approach taken in ADNI to standardization across sites and platforms of the MRI protocol, postacquisition corrections, and phantom‐based monitoring of all scanners could be used as a model for other multisite trials. J. Magn. Reson. Imaging 2008. © 2008 Wiley‐Liss, Inc.
Molecular and cellular MR imaging: Potentials and challenges for neurological applications
Authors: Hoehn Mathias , Himmelreich Uwe , Kruttwig Klaus , Wiedermann Dirk
Published: February 2008

This review presents the state of the art of molecular MRI and its application to experimental neurology and neuroscience. We do not repeat a broad, comprehensive overview over the rapidly growing literature in the field of “molecular MRI,” which is achieved by several recent reviews. Instead, we focus here on the potential of this imaging technique and its challenges to achieve useful new information in various fields of application with the aim of visualizing cellular processes in the brain, in both the physiological and pathophysiological context. Particular attention will be given to the visualization of cells grafted into the brain. For this goal, the recent most exciting studies are selected as the best examples to elucidate the method's fast expanding potentials. Attention is also given to the aspects of producing synergies by combining molecular MRI with other molecular imaging modalities, thus generating the most complex pictures of cellular and molecular events in the brain under in vivo conditions. J. Magn. Reson. Imaging 2008. © 2008 Wiley‐Liss, Inc.
Nonlinear myocardial signal intensity correction improves quantification of contrast‐enhanced first‐pass MR perfusion in humans
Authors: Hsu Li‐Yueh , Kellman Peter , Arai Andrew E
Published: February 2008

Purpose

To study the nonlinearity of myocardial signal intensity and gadolinium contrast concentration during first‐pass perfusion MRI, and to compare quantitative perfusion estimates using nonlinear myocardial signal intensity correction.

Materials and Methods

The nonlinearity of signal intensity and contrast concentration was simulated by magnetization modeling and evaluated in phantom measurements. A total of 10 healthy volunteers underwent rest and stress dual‐bolus perfusion studies using an echo‐planar imaging sequence at both short and long saturation‐recovery delay times (TD70 and TD150). Perfusion estimates were compared before and after the correction.

Results

The phantom data showed a linear relationship (R2 = 1.00 and 0.99) of corrected signal intensity vs. contrast concentrations. Peak myocardial contrast concentration averaged 0.64 ± 0.10 mmol · L−1 at rest and 0.91 ± 0.21 mmol · L−1 during stress for TD70 and were similar for TD150 (P = not significant [NS]). The corrections were larger for stress than rest perfusion and larger for TD150 than TD70 studies (both P < 0.01). Perfusion estimates of TD70 and TD150 stress studies were significantly different before the correction (P < 0.01) but equivalent after the correction (P = NS).

Conclusion

The nonlinearity between signal intensity and myocardial contrast concentration in perfusion MRI can be corrected through magnetization modeling. A nonlinear correction of myocardial signal intensity is feasible and improves quantitative perfusion analysis. J. Magn. Reson. Imaging 2008. © 2008 Wiley‐Liss, Inc.