bluuebunny/crossref_metadata_2025 huggingface dataset:
Gene signatures reflect the marked heterogeneity of tissue‐resident macrophages
Authors: Gorgani Nick N , Ma Yan , Clark Hilary F
Published: November 2007

Tissue‐resident macrophages play an important role in defense against pathogens and perform key functions in organ homeostasis, innate and adaptive immunity. Tissue macrophages originate from blood monocytes that infiltrate virtually every organ in the body. Macrophages in different tissues share many characteristics, including their ability to migrate, phagocytose particles, metabolize lipids and present antigens. Morphologically they are quite heterogeneous, and some distinct functions have been reported. The gene expression profile of macrophages is reflective of both their shared and distinct biological functions. Here, we show that macrophages from murine spleen, liver and peritoneum display dramatically different expression profiles. Clusters of genes were found to represent unique biological functions related to adhesion, antigen presentation, phagocytosis, lipid metabolism and signal transduction. Some gene families, such as integrins, are differentially expressed among the macrophages resident in different tissues, suggesting that the tissue of residence influences their biological function.
Exact solution for anisotropic diffusion-controlled reactions with partially reflecting conditions
Authors: Traytak Sergey D. , Price William S.
Published: November 2007

We investigate a generalization of the model of Solc and Stockmayer to describe the diffusion-controlled reactions between chemically anisotropic reactants taking into account the partially reflecting conditions on two parts of the reaction surface. The exact solution of the relevant mixed boundary-value problem was found for different ratios of the intrinsic rate constants. The results obtained may be used to test numerical programs that describe diffusion-controlled reactions in real systems of particles with anisotropic reactivity.
Quasi-simultaneous imaging/pulling analysis of single polyprotein molecules by atomic force microscopy
Authors: Valbuena Alejandro , Oroz Javier , Vera Andrés Manuel , Gimeno Alejandro , Gómez-Herrero Julio , Carrión-Vázquez Mariano
Published: November 2007

Most of studies in protein nanomechanics have used the atomic force microscope (AFM) in its force-measuring mode on immobilized protein repeats (polyproteins) as single-molecule markers. Here, we add imaging capabilities to a standard, state-of-the-art AFM “puller” and integrate the most powerful programs of analysis available for both AFM modes. This unique instrument allows high-resolution, quasi-simultaneous imaging/force spectroscopy in aqueous solution. We demonstrate its capabilities using polyproteins of a model system (titin I27 domain). This tool should greatly facilitate the development of a much needed universal functionalization system for AFM, one that should allow better sample control and an improved efficiency of protein immobilization.
Microwave absorption properties and mechanism of cagelike ZnO∕SiO2 nanocomposites
Authors: Cao Mao-Sheng , Shi Xiao-Ling , Fang Xiao-Yong , Jin Hai-Bo , Hou Zhi-Ling , Zhou Wei , Chen Yu-Jin
Published: November 2007

In this paper, cagelike ZnO∕SiO2 nanocomposites were prepared and their microwave absorption properties were investigated in detail. Dielectric constants and losses of the pure cagelike ZnO nanostructures were measured in a frequency range of 8.2–12.4GHz. The measured results indicate that the cagelike ZnO nanostructures are low-loss material for microwave absorption in X band. However, the cagelike ZnO∕SiO2 nanocomposites exhibit a relatively strong attenuation to microwave in X band. Such strong absorption is related to the unique geometrical morphology of the cagelike ZnO nanostructures in the composites. The microcurrent network can be produced in the cagelike ZnO nanostructures, which contributes to the conductive loss.
Oblique axisymmetric stagnation flows in magnetohydrodynamics
Authors: Amaouche M. , Naït-Bouda F. , Sadat H.
Published: November 2007

The present paper deals with the influence of the Lorentz force associated with an applied radial magnetic field on the axisymmetric stagnation flow impinging obliquely onto a uniformly rotating circular cylinder. It is found that the boundary layer flow is described by an exact solution of the Navier–Stokes equations when Hall effects are ignored. The stability of this basic solution is then considered in the framework of Görtler–Hammerlin assumption according to which linear disturbances inherit the underlying symmetry of the basic flow. The resulting eigenvalue problem is solved numerically by means of a pseudospectral method using Laguerre’s polynomials. The scheme is specifically designed to solve boundary layer equations. The numerical experiments indicate that the effect of cylinder rotation is to reduce the stability of the basic flow and most importantly the magnetic field acts to either increase or decrease it, depending on whether the rotation rate is smaller or greater than some critical value that changes with the Hartmann number. At criticality, the basic flow undergoes Hopf bifurcations leading to branching off solutions in the form of azimuthally travelling waves. In the case of axisymmetric disturbances the bifurcation remains of Hopf type provided that the Hartmann number is small enough, a saddle-node bifurcation is encountered in the opposite case.
Planar Josephson tunnel junctions in a transverse magnetic field
Authors: Monaco R. , Aaroe M. , Mygind J. , Koshelets V. P.
Published: November 2007

Traditionally, since the discovery of the Josephson effect in 1962, the magnetic diffraction pattern of planar Josephson tunnel junctions has been recorded with the field applied in the plane of the junction. Here we discuss the static junction properties in a transverse magnetic field where demagnetization effects imposed by the tunnel barrier and electrodes geometry are important. Measurements of the junction critical current versus magnetic field in planar Nb-based high-quality junctions with different geometry, size, and critical current density show that it is advantageous to use a transverse magnetic field rather than an in-plane field. The conditions under which this occurs are discussed.
Relation between giant magnetoresistance and interlayer exchange coupling in the magnetic multilayers
Authors: Xu M. , Xiong G. , Xu S.
Published: November 2007

In this paper, we reveal the relation between the giant magnetoresistance (GMR) effect and the phase of interlayer exchange coupling. A factor (α) drawn from the phase shift of interlayer exchange coupling can well account for the GMR of ferromagnetic/nonmagnetic (FM/NM) multilayers. It is shown that the achievable maximum GMR value generally occurs to the FM/NM multilayered structure with the α value approaches 1.0. The result presented in this work is highly relevant in the search for the multilayered ferromagnetic/nonmagnetic system possessing high GMR.
Hole states in Ge∕Si quantum-dot molecules produced by strain-driven self-assembly
Authors: Yakimov A. I. , Mikhalyov G. Yu. , Dvurechenskii A. V. , Nikiforov A. I.
Published: November 2007

Space-charge spectroscopy was employed to study hole emission from the confined states in vertically self-aligned double Ge quantum dots separated by a Si barrier. From the temperature- and frequency-dependent measurements, the hole binding energy was determined as a function of the separation between the dots, tSi. Increasing of the ground state hole energy due to formation of a bonding molecular orbital was found to be as large as ∼50meV at tSi=1.5nm. For a dot layer separation exceeding 3nm, the hole binding energy in double-dot molecule becomes smaller than the ionization energy of the single Ge dot, contrasting with a simplified quantum-mechanical molecular model. To analyze the experiment the electronic structure of two vertically coupled pyramidal Ge quantum dots embedded in Si was investigated by a nearest neighbor tight-binding single-particle Hamiltonian with the sp3 basis. The elastic strain due to the lattice mismatch between Ge and Si was included into the problem. The three-dimensional spatial strain distribution was found in terms of atomic positions using a valence-force-field theory with a Keating interatomic potential. It was demonstrated that formation of single-particle hole states in self-organized molecules is governed by the interplay among two effects. The first is the quantum-mechanical coupling between the individual states of two dots constituting the molecule. The second one originates from asymmetry of the strain field distribution within the top and bottom dots due to the lack of inversion symmetry with respect to the medium plane between the dots. Analysis of the biaxial strain distribution showed that anomalous decreasing of the hole binding energy below the value of the single dot with increasing interdot separation is caused by the partial strain relaxation upon dot stacking accompanied by the strain-induced reduction of the hole confinement potential. We found that the molecule-type hole state delocalized fairly over the two dots is formed only at tSi<3.3nm and at tSi>3.8nm. For the intermediate distances (3.3nm⩽tSi⩽3.8nm), the hole becomes confined mostly inside the bottom, most strained Ge dot. The overall agreement between theory and experiment turns out to be quite good, indicating the crucial role played by strain fields in electronic coupling of self-assembled quantum-dot molecules.
Migration volume for polaron dielectric relaxation in disordered materials
Authors: Papathanassiou A. N. , Sakellis I. , Grammatikakis J.
Published: November 2007

A theoretical study of the influence of pressure on the dielectric relaxation related with polaron tunneling and phonon-assisted hopping in disordered solids is developed. The sign and absolute value of the migration volume, which is obtained by employing the present formulation, evidence the nature of the relaxation. As a paradigm, positive and negative values of migration volume are evaluated by analyzing recently published dielectric loss measurements under pressure in semiconducting polypyrrole. A straightforward relation between the value of the migration volume and the nature of short-range polaron flow and the size of polaron distortion is revealed.
Enhancement of thermal conductivity in magnetite based nanofluid due to chainlike structures
Authors: Philip John , Shima P. D. , Raj Baldev
Published: November 2007

We observe a dramatic enhancement of thermal conductivity in a nanofluid containing magnetite particles of average diameter of 6.7nm under the influence of an applied magnetic field. The maximum enhancement in the thermal conductivity observed is 300% (k∕kf=4.0) at a particle loading of 6.3vol%. The increase in thermal conductivity is attributed to the effective conduction of heat through the chainlike structures formed in the nanofluid. This finding is consistent with the theoretical prediction of enhanced thermal conductivity in nanofluid containing fractal aggregates [R. Prasher et al., Appl. Phys. Lett.89, 143119 (2006)].
Large scale, highly ordered assembly of nanowire parallel arrays by differential roll printing
Authors: Yerushalmi Roie , Jacobson Zachery A. , Ho Johnny C. , Fan Zhiyong , Javey Ali
Published: November 2007

A differential roll printing strategy is developed to enable large-scale and uniform assembly of highly aligned and ordered nanowire arrays on various rigid and flexible substrate materials. The dynamics of the process are explored by tuning the linear sliding motion of the roller with respect to the rolling motion, clearly demonstrating the importance of the differential rolling process in the controlled assembly of nanowires. The potency and versatility of the method is further demonstrated by fabrication of nanowire transistor arrays on flexible substrates.
Initial phases in sputter deposited HfO2–Al2O3 nanolaminate films
Authors: Hoppe E. E. , Aita C. R. , Gajdardziska-Josifovska M.
Published: November 2007

Nanolaminate films of crystalline HfO2 and amorphous Al2O3 were grown by reactive sputter deposition on unheated fused SiO2 and the surface oxide of ⟨111⟩ Si. X-ray diffraction showed the amount of monoclinic (m) HfO2 decreased with decreasing HfO2 layer thickness, consistent with a finite crystal size effect. High resolution transmission electron microscopy of individual crystallites detected tetragonal (t) and orthorhombic (o) HfO2 as the initial phases formed. Whereas the t→m transition is accomplished by a shear mechanism, we demonstrate the important role of polysynthetic twinning for the o→m transition.
Metric conversion and geophysics
Authors: Green R.
Published: November 2007

Following the Metric Conversion Act of July, 1970, the Metric Conversion Board has circulated Universities and will be encouraging industry to commence the conversion to the new International System (SI) units.
Floristic and structural contrasts between natural savannas and anthropogenic pastures in a tropical dry landscape
Authors: López-Olmedo L. I. , Meave J. A. , Pérez-García E. A.
Published: November 2007

The magnitude of the biological differentiation between natural savannas and pastures (anthropogenic grasslands) coexisting in a single landscape, in terms of their floristic composition and community structure, was studied in the Nizanda region, Isthmus of Tehuantepec, Oaxaca State, southern Mexico. Vegetation samples of 15 m2 each were taken at 20 savanna and 11 pasture sites. Cover- and species richness-based diversity and dominance indices were calculated. Geomorphological and edaphic characteristics were also compared. Savannas generally occurred in hill summits with very shallow and stony, discontinuous and acidic soils; contrastingly, pastures were located in piedmonts and floodplains, with more neutral and less stony soils. Savanna sites differed from pasture sites in species richness and Shannon diversity. They did not differ in Simpson dominance index, but the identity of the dominant species was different in each community: Trachypogon spicatus (L.f.) Kuntze in savanna and Megathyrsus maximus (Jacq.) B.K.Simon et S.W.L.Jacobs in pasture. A low species-level similarity (Sørensen Index) was observed between them (8.2%), and genus-level similarity was only slightly higher (27.1%). The magnitude of the biological differentiation in both community floristics and structure between these two grass-dominated communities was larger than anticipated. Current management of savannas as pasture lands may potentially trigger a severe deterioration process involving both the landscape and its plant components.
Genetic diversity of citrus bacterial canker pathogens preserved in herbarium specimens
Authors: Li Wenbin , Song Qijian , Brlansky Ronald H. , Hartung John S.
Published: November 2007

Citrus bacterial canker (CBC) caused by
Xanthomonas axonopodis
pv.
citri
(Xac) was first documented in India and Java in the mid 19th century. Since that time, the known distribution of the disease has steadily increased. Concurrent with the dispersion of the pathogen, the diversity of described strains continues to increase, with novel strains appearing in Saudi Arabia, Iran, and Florida in the last decade. Herbarium specimens of infected plants provide an historical record documenting both the geographic distribution and genetic diversity of the pathogen in the past. However, no method was available to assess the genetic diversity within these herbarium samples. We have developed a method, insertion event scanning (IES), and applied the method to characterize the diversity present within CBC populations documented as herbarium specimens over the past century. IES is based on the specific amplification of junction fragments that define insertion events. The potential for IES in current forensic applications is demonstrated by finding an exact match of pathogen genotypes preserved in herbarium specimens from Japan and Florida, demonstrating the source of the original outbreak of citrus canker in Florida in 1911. IES is a very sensitive technique for differentiating bacterial strains and can be applied to any of the several hundred bacteria for which full genomic sequence data are available.
Visual grouping in human parietal cortex
Authors: Xu Yaoda , Chun Marvin M.
Published: November 2007

To efficiently extract visual information from complex visual scenes to guide behavior and thought, visual input needs to be organized into discrete units that can be selectively attended and processed. One important such selection unit is visual objects. A crucial factor determining object-based selection is the grouping between visual elements. Although human lesion data have pointed to the importance of the parietal cortex in object-based representations, our understanding of these parietal mechanisms in normal human observers remains largely incomplete. Here we show that grouped shapes elicited lower functional MRI (fMRI) responses than ungrouped shapes in inferior intraparietal sulcus (IPS) even when grouping was task-irrelevant. This relative ease of representing grouped shapes allowed more shape information to be passed onto later stages of visual processing, such as information storage in superior IPS, and may explain why grouped visual elements are easier to perceive than ungrouped ones after parietal brain lesions. These results are discussed within a neural object file framework, which argues for distinctive neural mechanisms supporting object individuation and identification in visual perception.
ANCCA, an estrogen-regulated AAA+ ATPase coactivator for ERα, is required for coregulator occupancy and chromatin modification
Authors: Zou June X. , Revenko Alexey S. , Li Li B. , Gemo Abigael T. , Chen Hong-Wu
Published: November 2007

AAA+ proteins play crucial roles in diverse biological processes via their ATPase-driven remodeling of macromolecular complexes. Here we report our identification of an evolutionarily conserved AAA+ protein, ANCCA/pro2000, endowed with a bromodomain that is strongly induced by estrogen in human breast cancer cells and is a direct target of protooncogene ACTR/AIB1/SRC-3. We found that ANCCA associates directly with estrogen-bound estrogen receptor (ER) α and ACTR. It is selectively recruited, upon estrogen stimulation, to a subset of ERα target genes including cyclin D1, c-myc, and E2F1 and is required for their estrogen-induced expression as well as breast cancer cell proliferation. Further studies indicate that ANCCA binds and hydrolyzes ATP and is critical for recruitment of coregulator CBP and histone hyperacetylation at the ER target chromatin. Moreover, mutations at the ATP binding motifs rendered ANCCA defective as a coactivator in mediating estrogen induction of gene expression. Together, our findings reveal an unexpected layer of regulatory mechanism in hormone signaling mediated by ANCCA and suggest that hormone-induced assembly of transcriptional coregulator complexes at chromatin is a process facilitated by AAA+ ATPase proteins.
Cdk1 phosphorylation of BubR1 controls spindle checkpoint arrest and Plk1-mediated formation of the 3F3/2 epitope
Authors: Wong Oi Kwan , Fang Guowei
Published: November 2007

Accurate chromosome segregation is controlled by the spindle checkpoint, which senses kinetochore– microtubule attachments and tension across sister kinetochores. An important step in the tension-signaling pathway involves the phosphorylation of an unknown protein by polo-like kinase 1/Xenopus laevis polo-like kinase 1 (Plx1) on kinetochores lacking tension to generate the 3F3/2 phosphoepitope. We report here that the checkpoint protein BubR1 interacts with Plx1 and that phosphorylation of BubR1 by Plx1 generates the 3F3/2 epitope. Formation of the BubR1 3F3/2 epitope by Plx1 requires a prior phosphorylation of BubR1 on Thr 605 by cyclin-dependant kinase 1 (Cdk1). This priming phosphorylation of BubR1 by Cdk1 is required for checkpoint-mediated mitotic arrest and for recruitment of Plx1 and the checkpoint protein Mad2 to unattached kinetochores. Biochemically, formation of the 3F3/2 phosphoepitope by Cdk1 and Plx1 greatly enhances the kinase activity of BubR1. Thus, Cdk1-mediated phosphorylation of BubR1 controls checkpoint arrest and promotes the formation of the kinetochore 3F3/2 epitope.
A genome-wide RNAi screen reveals multiple regulators of caspase activation
Authors: Yi Caroline H. , Sogah Dodzie K. , Boyce Michael , Degterev Alexei , Christofferson Dana E. , Yuan Junying
Published: November 2007

Apoptosis is an evolutionally conserved cellular suicide mechanism that can be activated in response to a variety of stressful stimuli. Increasing evidence suggests that apoptotic regulation relies on specialized cell death signaling pathways and also integrates diverse signals from additional regulatory circuits, including those of cellular homeostasis. We present a genome-wide RNA interference screen to systematically identify regulators of apoptosis induced by DNA damage in Drosophila melanogaster cells. We identify 47 double- stranded RNA that target a functionally diverse set of genes, including several with a known function in promoting cell death. Further characterization uncovers 10 genes that influence caspase activation upon the removal of Drosophila inhibitor of apoptosis 1. This set includes the Drosophila initiator caspase Dronc and, surprisingly, several metabolic regulators, a candidate tumor suppressor, Charlatan, and an N-acetyltransferase, ARD1. Importantly, several of these genes show functional conservation in regulating apoptosis in mammalian cells. Our data suggest a previously unappreciated fundamental connection between various cellular processes and caspase-dependent cell death.
Notch ligand Delta-like 4 regulates disease pathogenesis during respiratory viral infections by modulating Th2 cytokines
Authors: Schaller Matthew A. , Neupane Rupak , Rudd Brian D. , Kunkel Steven L. , Kallal Lara E. , Lincoln Pamela , Lowe John B. , Man Yunfang , Lukacs Nicholas W.
Published: November 2007

Recent data have indicated that an important instructive class of signals regulating the immune response is Notch ligand–mediated activation. Using quantitative polymerase chain reaction, we observed that only Delta-like 4 (dll4) was up-regulated on bone marrow–derived dendritic cells after respiratory syncytial virus (RSV) infection, and that it was dependent on MyD88-mediated pathways. Using a polyclonal antibody specific for dll4, the development of RSV-induced disease was examined. Animals treated with anti-dll4 had substantially increased airway hyperresponsiveness compared with control antibody-treated animals. When the lymphocytic lung infiltrate was examined, a significant increase in total CD4+ T cells and activated (perforin+) CD8+ T cells was observed. Isolated lung CD4+ T cells demonstrated significant increases in Th2-type cytokines and a decrease in interferon γ, demonstrating an association with increased disease pathogenesis. Parellel in vitro studies examining the integrated role of dll4 with interleukin-12 demonstrated that, together, both of these instructive signals direct the immune response toward a more competent, less pathogenic antiviral response. These data demonstrate that dll4-mediated Notch activation is one regulator of antiviral immunity.
A protein associated with Toll-like receptor (TLR) 4 (PRAT4A) is required for TLR-dependent immune responses
Authors: Takahashi Koichiro , Shibata Takuma , Akashi-Takamura Sachiko , Kiyokawa Takashi , Wakabayashi Yasutaka , Tanimura Natsuko , Kobayashi Toshihiko , Matsumoto Fumi , Fukui Ryutaro , Kouro Taku , Nagai Yoshinori , Takatsu Kiyoshi , Saitoh Shin-ichiroh , Miyake Kensuke
Published: November 2007

Immune cells express multiple Toll-like receptors (TLRs) that are concomitantly activated by a variety of pathogen products. Although there is presumably a need to coordinate the expression and function of TLRs in individual cells, little is known about the mechanisms governing this process. We show that a protein associated with TLR4 (PRAT4A) is required for multiple TLR responses. PRAT4A resides in the endoplasmic reticulum, and PRAT4A knockdown inhibited trafficking of TLR1 and TLR4 to the cell surface and ligand-induced trafficking of TLR9 to lysosomes. Other cell-surface molecules were expressed normally on immunocytes from PRAT4A−/− mice. There was impaired cytokine production to TLR ligands, except to the TLR3 ligand poly(I:C), and to whole bacteria. Activation of antigen-specific T helper type 1 responses were also defective. Moreover, PRAT4A−/− bone marrow chimeric mice were resistant to lipopolysaccharide-induced sepsis. These results suggest that PRAT4A regulates the subcellular distribution and response of multiple TLRs and is required for both innate and adaptive immune responses.
Mast cell deficiency in KitW-sh mice does not impair antibody-mediated arthritis
Authors: Zhou Joseph S. , Xing Wei , Friend Daniel S. , Austen K. Frank , Katz Howard R.
Published: November 2007

We previously reported that joint swelling, synovial thickening, and cartilage matrix depletion induced by the injection of anti-collagen monoclonal antibodies and lipopolysaccharide (LPS) in BALB/c mice are increased in the absence of inhibitory leukocyte immunoglobulin (Ig)-like receptor B4 (LILRB4; formerly gp49B1) in a neutrophil-dependent manner. Because both mast cells and neutrophils express LILRB4, we sought a mast cell requirement with mast cell–deficient mouse strains, but unexpectedly obtained full arthritis in KitW-sh mice and full resistance in KitW/KitW-v mice. KitW-sh mice were indeed mast cell deficient as assessed by histology and the absence of IgE/mast cell–dependent passive cutaneous anaphylaxis in the ear and joint as well as passive systemic anaphylaxis. Deletion of LILRB4 in KitW-sh mice exacerbated anti-collagen/LPS-induced joint swelling that was abolished by neutrophil depletion, establishing a counterregulatory role for LILRB4 in the absence of mast cells. Whereas blood neutrophil levels and LPS-elicited tissue neutrophilia were equal in KitW-sh and Kit+ mice, both were impaired in KitW/KitW-v mice. Although both strains are mast cell deficient and protected from IgE-mediated anaphylactic reactions, their dramatically different responses to autoantibody-mediated, neutrophil-dependent immune complex arthritis suggest that other host differences determine the extent of mast cell involvement. Thus, a conclusion for an absolute mast cell role in a pathobiologic process requires evidence from both strains.
A Segment of γ ENaC Mediates Elastase Activation of Na+ Transport
Authors: Adebamiro Adedotun , Cheng Yi , Rao U. Subrahmanyeswara , Danahay Henry , Bridges Robert J.
Published: November 2007

The epithelial Na+ channel (ENaC) that mediates regulated Na+ reabsorption by epithelial cells in the kidney and lungs can be activated by endogenous proteases such as channel activating protease 1 and exogenous proteases such as trypsin and neutrophil elastase (NE). The mechanism by which exogenous proteases activate the channel is unknown. To test the hypothesis that residues on ENaC mediate protease-dependent channel activation wild-type and mutant ENaC were stably expressed in the FRT epithelial cell line using a tripromoter human ENaC construct, and protease-induced short-circuit current activation was measured in aprotinin-treated cells. The amiloride-sensitive short circuit current (INa) was stimulated by aldosterone (1.5-fold) and dexamethasone (8-fold). Dexamethasone-treated cells were used for all subsequent studies. The serum protease inhibitor aprotinin decreased baseline INa by approximately 50% and INa could be restored to baseline control values by the exogenous addition of trypsin, NE, and porcine pancreatic elastase (PE) but not by thrombin. All protease experiments were thus performed after exposure to aprotinin. Because NE recognition of substrates occurs with a preference for binding valines at the active site, several valines in the extracellular loops of α and γ ENaC were sequentially substituted with glycines. This scan yielded two valine residues in γ ENaC at positions 182 and 193 that resulted in inhibited responses to NE when simultaneously changed to other amino acids. The mutations resulted in decreased rates of activation and decreased activated steady-state current levels. There was an ∼20-fold difference in activation efficiency of NE against wild-type ENaC compared to a mutant with glycine substitutions at positions 182 and 193. However, the mutants remain susceptible to activation by trypsin and the related elastase, PE. Alanine is the preferred P1 position residue for PE and substitution of alanine 190 in the γ subunit eliminated INa activation by PE. Further, substitution with a novel thrombin consensus sequence (LVPRG) beginning at residue 186 in the γ subunit (γTh) allowed for INa activation by thrombin, whereas wild-type ENaC was unresponsive. MALDI-TOF mass spectrometric evaluation of proteolytic digests of a 23-mer peptide encompassing the identified residues (T176-S198) showed that hydrolysis occurred between residues V193 and M194 for NE and between A190 and S191 for PE. In vitro translation studies demonstrated thrombin cleaved the γTh but not the wild-type γ subunit. These results demonstrate that γ subunit valines 182 and 193 are critical for channel activation by NE, alanine 190 is critical for channel activation by PE, and that channel activation can be achieved by inserting a novel thrombin consensus sequence. These results support the conclusion that protease binding and perhaps cleavage of the γ subunit results in ENaC activation.
Evidence for a Deep Pore Activation Gate in Small Conductance Ca2+-activated K+ Channels
Authors: Bruening-Wright Andrew , Lee Wei-Sheng , Adelman John P. , Maylie James
Published: November 2007

Small conductance calcium-gated potassium (SK) channels share an overall topology with voltage-gated potassium (Kv) channels, but are distinct in that they are gated solely by calcium (Ca2+), not voltage. For Kv channels there is strong evidence for an activation gate at the intracellular end of the pore, which was not revealed by substituted cysteine accessibility of the homologous region in SK2 channels. In this study, the divalent ions cadmium (Cd2+) and barium (Ba2+), and 2-aminoethyl methanethiosulfonate (MTSEA) were used to probe three sites in the SK2 channel pore, each intracellular to (on the selectivity filter side of) the region that forms the intracellular activation gate of voltage-gated ion channels. We report that Cd2+ applied to the intracellular side of the membrane can modify a cysteine introduced to a site (V391C) just intracellular to the putative activation gate whether channels are open or closed. Similarly, MTSEA applied to the intracellular side of the membrane can access a cysteine residue (A384C) that, based on homology to potassium (K) channel crystal structures (i.e., the KcsA/MthK model), resides one amino acid intracellular to the glycine gating hinge. Cd2+ and MTSEA modify with similar rates whether the channels are open or closed. In contrast, Ba2+ applied to the intracellular side of the membrane, which is believed to block at the intracellular end of the selectivity filter, blocks open but not closed channels when applied to the cytoplasmic face of rSK2 channels. Moreover, Ba2+ is trapped in SK2 channels when applied to open channels that are subsequently closed. Ba2+ pre-block slows MTSEA modification of A384C in open but not in closed (Ba2+-trapped) channels. The findings suggest that the SK channel activation gate resides deep in the vestibule of the channel, perhaps in the selectivity filter itself.
Suicidal thoughts and associated factors in an elderly population
Authors: Forsell Y. , Jorm A. F. , Winblad B.
Published: November 2007

This study examined the prevalence of suicidal thoughts and associated factors in an elderly population. Data for 969 elderly subjects from a population‐based study were used, and examinations by physicians, including psychiatric examination and informants' interview, were assessed. In total, 13.3% of the subjects had had suicidal thoughts during the last 2 weeks (10.8% fleetingly and 2.5% frequently). Of those who had had fleeting suicidal thoughts, 26.7% also had major depression, while 50% of those who had frequent suicidal thoughts were depressed. In addition, suicidal thoughts were associated with increased disability in daily living, institutionalization, visual problems and the use of psychotropic drugs. It is concluded that a careful psychiatric assessment is necessary when suicidal thoughts are expressed by an elderly person.
Cotard's syndrome in a 15‐year‐old girl
Authors: Cohen D. , Cottias C. , Basquin M.
Published: November 2007

We here describe a case of Cotard's syndrome in a 15‐year‐old girl who exhibited a short period of malignant catatonia, and the positive effect of electroconvulsive therapy (ECT) on her disorder. A psychopathological hypothesis is proposed.
Attitudes of psychiatric nursing personnel towards patients who have attempted suicide
Authors: Samuelsson M. , Åsberg M. , Gustavsson J. P.
Published: November 2007

The aim of this study was to examine the attitudes towards suicidal patients of a group of psychiatric nursing personnel (n=197) and to establish a baseline of attitudinal measures against which the effects of a subsequent educational programme can be assessed. A scale, known as the Understanding of Suicide Attempt Patient Scale (USP Scale) was developed for this purpose. The reliability of the scale was satisfactory, and its correlation with visual analogue scale (VAS) scores based on clinical vignettes suggests that it has validity. Women tended to be more sympathetic than men, and older personnel were more favourably disposed than the younger nurses. Differences between personnel working in different settings were found, which might be explained by differences in the frequency of contact with suicide‐prone patients, more frequent exposure being associated with more positive attitudes.
The assessment of light intensity preference in psychiatric patients: a questionnaire
Authors: Gerbaldo H. , Cassady S. , Maurer K. , Pieschl D.
Published: November 2007

The assessment of abnormal light‐related behaviour is important for methodological reasons, and has a prophylactic and heuristic value. Since no operationalization of these behaviour patterns has been published until now, we constructed a questionnaire to identify abnormal light intensity preference based on a systematic study and previous case reports. We administered the questionnaire to patients with schizophrenia (n=46) or major depression (n=55), and to healthy control subjects (n=70). Photophilia was more frequently diagnosed in schizophrenia than in depression (P<0.001). Photophobia was more frequently observed in depression than in schizophrenia; however, this difference was not statistically significant. None of the healthy subjects showed these phenomena. The kappa value was 0.66 for photophilia and 0.65 for photophobia. Patients with schizophrenia had a higher mean photophilia score than depressive patients (P<0.001) and healthy subjects (P<0.05). Depressed patients had higher photophobia scores than schizophrenics (P<0.05) and healthy subjects (P<0.001). The photophilia score was positively correlated and the photophobia score was negatively correlated with the light intensity preference (measured by means of a photometer) (P<0.001). A significant positive correlation between the photophilia score and the percentage of time spent in bright and very bright areas was observed (P<0.05). Scores were not related to age or gender. These results represent initial data in support of the validity and reliability of our questionnaire for distinguishing between patients with and without abnormal light‐exposure behaviour patterns.
Down‐rating lifetime suicide risk in major depression
Authors: Blair‐West G. W. , Mellsop G. W. , Eyeson‐Annan M. L.
Published: November 2007

For 25 years the medical profession has accepted that of every 100 individuals with major depressive disorder (MDD), 15 subjects will ultimately commit suicide. The present paper demonstrates that the lifetime suicide risk in this condition cannot be so high. Conservative age‐specific calculations give a lifetime suicide risk in MDD of 3.5%. Selection of hospital‐based, high suicide risk, study populations in the index research, when most sufferers are out‐patients, is the primary contributor to the overestimation of suicide risk. Evolving classification systems are a further factor. In terms of suicide risk, MDD is not a homogenous diagnostic category. As has been reliably replicated, the small subgroup of patients who have experienced hospital admission do experience a much greater lifetime suicide risk.
Partial remission in depressive disorders
Authors: Cornwall P. L. , Scott J.
Published: November 2007

Although the concept of partial or incomplete remission from depression has been noted in the literature for many decades, it is only recently that a precise definition of partial remission has been formulated (1). This paper reviews publications relating to this concept, in terms of prevalence, clinical characteristics and implications for prognosis. There have been too few studies to allow conclusive evidence to be presented, but partial remission may affect one third of subjects treated for depression, and may increase the risk of further depressive relapse and adversely affect social and work performance. This paper highlights the need to increase awareness of this concept among clinicians so that residual symptoms may be aggressively treated, and also comments on the need for researchers to consider this important group in all treatment and outcome studies.
The hypothalamic‐pituitary‐thyroid axis in major depression
Authors: Sullivan P. F. , Wilson D. A. , Mulder R. T. , Joyce P. R.
Published: November 2007

We investigated the capacity of several thyroid‐axis measures to distinguish between depressed and control subjects and determined whether these variables were related to antidepressant treatment response. We studied 105 subjects who fulfilled the DSM‐III‐R criteria for a current major depressive episode and 41 volunteers with no current mental disorder. The following thyroid‐axis variables were measured: difference between T4 levels at 09.00 hours and 13.00 hours; baseline TSH; maximal TSH response to 400 μg TRH (Δmax TSH); and presence of a blunted Δmax TSH. The T4 difference variable alone distinguished between depressed and control subjects. In multivariate analyses, T4 difference and Δmax TSH were independently related to antidepressant‐treatment outcome, and predicted a modest proportion (14%) of the variance in outcome. The relationship between these two variables and treatment outcome was particularly strong in depressed male subjects who were receiving desipramine, for whom they accounted for 36% of the variance in treatment outcome. The T4 difference variable both distinguished between depressed and control subjects and was related to treatment outcome. Although this finding requires replication, it is consistent with other reports of the usefulness of thyroid‐axis indices measured at different times of day in depressed patients.
Low body weight in male children an adolescents with schizoid personality disorder or Asperger's disorder
Authors: Hebebrand J. , Hennighausen K. , Nau S. , Himmelmann G. W. , Schulz E. , Schäfer H. , Remschmidt H.
Published: November 2007

This study explored the hypothesis that body weight is reduced in male children and adolescents with schizoid personality disorder or Asperger's disorder. The body weights of 33 consecutively admitted male subjects with one of these disorders were retrospectively assessed with percentiles for the body mass index (BMI). The mean percentile (±SD) for the BMI was 31.6±27.6 and differed significantly from the expected value of 50 (P < 0.001). Ten subjects had a BMI of ≤10th age percentile. Post hoc comparisons revealed that BMI percentiles were (a) reduced to a similar extent in patients with schizoid personality disorder and Asperger's disorder and (b) reduced to a greater extent in patients with abnormal eating behaviour. During childhood and adolescence both diagnoses are associated with an increased risk of being underweight. Population‐based BMI percentiles are useful for detecting associations between specific psychopathological syndromes and body weight.
Suicides among physicians, engineers and teachers: the prevalence of reported depression, admissions to hospital and contributory causes of death
Authors: Lindeman S. , Läärä E. , Vuori E. , Lönnqvist J.
Published: November 2007

The number of admissions to hospital, reported diagnoses, prevalence of reported depression and contributory causes of death among Finnish physicians, engineers and teachers who committed completed suicide between 1986 and 1993 were studied. The data for hospital admissions with diagnoses were obtained from the Finnish Hospital Discharge Register. Thin‐layer chromatography was used to detect drugs in the liver, a dual‐column gas chromatographic method was used for screening and quantification of drugs in the blood sample, and a head‐space chromatographic method was used to measure blood alcohol levels. Physicians had more somatic diagnoses than the reference groups, and the prevalence of reported depression was higher among females than males. A minority of the depressed subjects had been admitted to hospital, although depression was observed to be the most prevalent contributory cause of death in all of the groups studied. The physicians used solid or liquid substances, especially barbiturates, as the main method of suicide. It is possible that depression in physicians, especially in male subjects, is undertreated in psychiatric hospitals.
Parent, teacher and self‐reports as predictors of signs of disturbance in adolescents: whose information carries the most weight?
Authors: Verhulst F. C. , Dekker M. C. , van der Ende J.
Published: November 2007

We evaluated the ability of parents, teachers and self‐reports to predict signs of maladjustment in 353 11‐ to 14‐year‐olds from the general population, over a 4‐year time interval. Odds ratios were computed in order to test the ability of problem scales to predict later mental health referral and measures of parents’ and children's own perceptions of the existence of major problems. Each informant made its own unique and indispensable contribution to the prediction of signs of maladjustment. Although teachers are often perceived as less able to assess internalizing problems than mothers and the children themselves, the present study showed that teachers’ evaluations of internalizing problems are highly relevant if we take their ability to predict the subject's own perceptions of having problems as the criterion.
Eating disorders and antecedent anxiety disorders: a controlled study
Authors: Bulik C. M. , Sullivan P. F. , Fear J. I. , Joyce P. R.
Published: November 2007

We compared the prevalence and age of onset of adult and childhood anxiety disorders relative to the primary diagnosis in 68 women with anorexia nervosa (AN), 116 women with bulimia nervosa (BN), 56 women with major depression with no eating disorder (MD) and 98 randomly selected controls (RC) in order to determine whether antecedent anxiety disorders are plausible risk factors for AN and BN. Comorbid anxiety disorders were common in all three clinical groups (AN, 60%; BN, 57%; MD, 48%). In 90% of AN women, 94% of BN women and 71 % of MD women, anxiety disorders preceded the current primary condition (P=0.01), although panic disorder tended to develop after the onset of AN, BN or MD. In multivariate logistic regressions, the odds ratios (ORs) for overanxious disorder (OR=13.4) and obsessive‐compulsive disorder (OR=11.8) were significantly elevated for AN. The ORs for overanxious disorder and social phobia were significantly elevated for BN (OROAD,=4.9; ORSP=15.5) and MD (OROAD,=6.1; ORSP=6.4). These data suggest that certain anxiety disorders are non‐specific risk factors for later affective and eating disorders, and others may represent more specific antecedent risk factors.
A cross‐cultural breakdown of Swedish suicide
Authors: Ferrada‐Noli M.
Published: November 2007

In this cross‐cultural, nation‐wide study including all immigrant groups in Sweden, over 10 000 suicides and undetermined cases occurring during the period 1987‐1991 were analysed. Diagnoses of the underlying causes of death were classified according to ICD‐9, all of the alternatives E950‐E959 and E980‐E989 being selected. Definite and overall suicide rates were estimated for each immigrant group represented. We found an overrepresentation of immigrants in the Swedish suicide statistics nationwide. A total of 15 countries (60% of the immigrant population) manifested more observed than expected suicides and undetermined cases. This overrepresentation was statistically significant among immigrants from Russia, Finland, Germany, Denmark and Norway (the immigrant population of these countries represents nearly 50% of the total population of immigrants in Sweden). Other nationalities with an increased suicide incidence were from Poland, Hungary, Czechoslovakia, Austria, Korea, The Netherlands, France, Spain and Uruguay. The risk of an immigrant dying of a cause related to suicide was found to be 1.5 times higher than that for a native Swede. Furthermore, the increased suicide rates observed among the immigrant groups in Sweden were found to be higher than in the respective countries of origin for 90% of the nationalities investigated, including those characterized by a relatively high refugee flow to Sweden, the rank order being generally the same both in the countries of origin and in Sweden. The immigrant groups with the highest suicide rates in our study were from Russia, Finland and Hungary. Suggestions are made concerning the possible involvement of underlying cultural, anthropological and genetic factors in this phenomenon.
Hopelessness, impulsiveness and intent among suicide attempters with major depression, alcohol dependence, or both
Authors: Suominen K. , Isometsä E. , Henriksson M. , Ostamo A. , Lönnqvist J.
Published: November 2007

The present study examined differences in hopelessness, impulsiveness and suicide intent between suicide attempters with either major depression or alcohol dependence, comorbid major depression and alcohol dependence, and those without these disorders. A sample of 114 patients from consecutive cases of attempted suicide referred to a general hospital in Helsinki was interviewed and diagnosed according to DSM‐III‐R. Suicide intent was measured by the Beck Suicide Intent Scale (SIS) and hopelessness was assessed by the Beck Hopelessness Scale (HS). Impulsiveness of the suicide attempt was measured by two items of the SIS. Suicide attempters with major depression without comorbid alcohol dependence had higher suicide intent and lower impulsiveness than attempters with non‐depressive alcohol dependence. Suicide attempts may differ between subjects with major depression, alcoholism or both disorders in terms of impulsiveness and suicide intent.
First‐trimester maternal gestational infection and cycloid psychosis
Authors: Stöber G. , Kocher I. , Franzek E. , Beckmann H.
Published: November 2007

Using a structured interview, the mothers of patients with cycloid psychosis, manic depression and controls (40 mothers in each case) were investigated in order to assess the occurrence of maternal gestational infection and other obstetric complications during pregnancy with the affected child. The cycloid psychoses with low heritability and a good long‐term prognosis were found to be significantly associated with first‐trimester respiratory infection (i.e. influenza and febrile cold). Furthermore, maternal infection seems to predict an early onset in cycloids. In manic depression, we failed to identify a significant link with maternal gestational infection or other obstetric complications. These findings are discussed in the light of our previous reports of an excess of maternal gestational infections during the second trimester in chronic schizophrenics. Our results suggest that the exogenously induced disturbances of fetal brain maturation during the first trimester of gestation caused by maternal respiratory infection via live virus or disturbed maternal immune response are involved in the aetiology of cycloid psychoses.