bluuebunny/crossref_metadata_2025 huggingface dataset:
Subconscious Manipulation of Pain Expectation Can Modulate Cortical Nociceptive Processing
Authors: Lewis Gwyn N. , Leys Adam , Rice David A. , McNair Peter J.
Published: December 2013

Objective

To determine whether manipulation of the expectation of pain inhibition can enhance the efficacy of conditioned pain modulation in healthy participants

Methods

A conditioned pain modulation paradigm was used to investigate the effect of psychological manipulation of expectation on pain inhibition. In 19 healthy men, the lower limb nociceptive flexion reflex was elicited in isolation (test stimulus) and during application of 2 forms of conditioning stimuli. Following application of the first conditioning stimulus (CS1), the participants were informed that the subsequent conditioning stimulus (CS2) would elicit a greater amount of inhibition of test pain compared with the first. Lower limb flexion reflex size, perceived pain ratings of the test stimulus, and ratings of expected pain modulation were obtained for both test and conditioning protocols.

Results

The inhibition of perceived pain was significantly greater with CS2 compared with CS1; however, there was no significant difference in inhibition of nociceptive flexion reflex size or the participant's reported expectation of pain modulation between the 2 conditioning stimuli.

Discussion

As perceived pain inhibition was enhanced but flexion reflex size unchanged following the intervention, we suggest that the intervention gave rise to an inhibition of ascending nociceptive information at a supraspinal level resulting in reduced pain perception without influencing spinal level processing of nociceptive input. The finding that conditioned pain modulation can be enhanced is of relevance to clinical pain populations who commonly show impaired inhibition.
Functional characterization of the two ferrochelatases in Arabidopsis thaliana
Authors: SCHARFENBERG MICHAEL , MITTERMAYR LUKAS , VON ROEPENACK‐LAHAYE EDDA , SCHLICKE HAGEN , GRIMM BERNHARD , LEISTER DARIO , KLEINE TATJANA
Published: December 2013

The enzyme ferrochelatase catalyses the formation of protoheme by inserting Fe2+ into protoporphyrin IX. Although most organisms express only one ferrochelatase, all land plants analysed so far possess at least two ferrochelatase proteins. Analysis of publicly available expression data suggests that the two Arabidopsis thaliana ferrochelatases, FC1 and FC2, serve different functions, corroborating previous assumptions. Co‐expression analysis of FC1 and FC2, together with microarray analyses, implies that fc1 and fc2 trigger different modes of plastid signalling in roots and leaves, respectively, and indicates that FC2 might be involved in stress responses. Thus, loss of FC2 increases resistance to salt and flagellin treatment. Whereas fc1 plants showed no obvious mutant phenotype, fc2 mutants formed abnormally small, pale green rosette leaves; were low in chlorophylls, carotenoids and several photosynthetic proteins; and their photosynthetic performance was impaired. These phenotypes are attenuated by growth in continuous light, in agreement with the finding that fc2 plants accumulate protochlorophyllide and display a fluorescent (flu) phenotype in the dark. In consequence we show that, contrary to earlier suggestions, FC2 produces heme not only for photosynthetic cytochromes, but also for proteins involved in stress responses, whereas the impairment of FC1 apparently interferes only marginally with stress responses.
Biochemical and physiological mechanisms underlying effects of Cucumber mosaic virus on host‐plant traits that mediate transmission by aphid vectors
Authors: MAUCK KERRY E. , DE MORAES CONSUELO M. , MESCHER MARK C.
Published: December 2013

The transmission of insect‐vectored diseases entails complex interactions among pathogens, hosts and vectors. Chemistry plays a key role in these interactions; yet, little work has addressed the chemical ecology of insect‐vectored diseases, especially in plant pathosystems. Recently, we documented effects of Cucumber mosaic virus (CMV) on the phenotype of its host (Cucurbita pepo) that influence plant‐aphid interactions and appear conducive to the non‐persistent transmission of this virus. CMV reduces host‐plant quality for aphids, causing rapid vector dispersal. Nevertheless, aphids are attracted to the elevated volatile emissions of CMV‐infected plants. Here, we show that CMV infection (1) disrupts levels of carbohydrates and amino acids in leaf tissue (where aphids initially probe plants and acquire virions) and in the phloem (where long‐term feeding occurs) in ways that reduce plant quality for aphids; (2) causes constitutive up‐regulation of salicylic acid; (3) alters herbivore‐induced jasmonic acid biosynthesis as well as the sensitivity of downstream defences to jasmonic acid; and (4) elevates ethylene emissions and free fatty acid precursors of volatiles. These findings are consistent with previously documented patterns of aphid performance and behaviour and provide a foundation for further exploration of the genetic mechanisms responsible for these effects and the evolutionary processes that shape them.
oca2 regulation of chromatophore differentiation and number is cell type specific in zebrafish
Authors: Beirl Alisha J. , Linbo Tor H. , Cobb Marea J. , Cooper Cynthia D.
Published: December 2013

We characterized a zebrafish mutant that displays defects in melanin synthesis and in the differentiation of melanophores and iridophores of the skin and retinal pigment epithelium. Positional cloning and candidate gene sequencing link this mutation to a 410‐kb region on chromosome 6, containing the oculocutaneous albinism 2 (oca2) gene. Quantification of oca2 mutant melanophores shows a reduction in the number of differentiated melanophores compared with wildtype siblings. Consistent with the analysis of mouse Oca2‐deficient melanocytes, zebrafish mutant melanophores have immature melanosomes which are partially rescued following treatment with vacuolar‐type ATPase inhibitor/cytoplasmic pH modifier, bafilomycin A1. Melanophore‐specific gene expression is detected at the correct time and in anticipated locations. While oca2 zebrafish display unpigmented gaps on the head region of mutants 3 days post‐fertilization, melanoblast quantification indicates that oca2 mutants have the correct number of melanoblasts, suggesting a differentiation defect explains the reduced melanophore number. Unlike melanophores, which are reduced in number in oca2 mutants, differentiated iridophores are present at significantly higher numbers. These data suggest distinct mechanisms for oca2 in establishing differentiated chromatophore number in developing zebrafish.
Expression of insulin‐like growth factor‐1 receptor in metastatic uveal melanoma and implications for potential autocrine and paracrine tumor cell growth
Authors: Yoshida Makoto , Selvan Senthamil , McCue Peter A. , DeAngelis Tiziana , Baserga Renato , Fujii Ami , Rui Hallgeir , Mastrangelo Michael J. , Sato Takami
Published: December 2013

We investigated the importance of the insulin‐like growth factor‐1 receptor (IGF‐1R) in hepatic metastases of uveal melanoma. The expression pattern of IGF‐1R in archival tissue samples of hepatic metastasis from 24 patients was analyzed by immunohistochemistry. All the samples of hepatic metastases stained positive for IGF‐1R. To investigate the biological role of IGF‐1R on the growth of metastatic uveal melanoma, a long‐term cell line obtained from a hepatic metastasis (TJU‐UM001) was evaluated. TJU‐UM001 expressed cell surface IGF‐1R (>90%) and proliferated in response to exogenous and endogenous insulin‐like growth factor‐1 (IGF‐1). Correlatively, anti‐IGF‐1R antibody completely blocked IGF‐1‐induced growth of TJU‐UM001 cells. IGF‐1 preferentially induced phosphorylation of Akt (S473) in quiescent TJU‐UM001 cells, and this was blocked by anti‐IGF‐1R antibody. This study suggests that autocrine and paracrine mechanisms underlie IGF‐1‐induced growth of metastatic uveal melanoma and underscore the potential benefit of IGF‐1 or IGF‐1R antagonism in treatment for metastatic uveal melanoma.
Disruption of GRM1‐mediated signalling using riluzole results in DNA damage in melanoma cells
Authors: Wall Brian A. , Wangari‐Talbot Janet , Shin Seung S. , Schiff Devora , Sierra Jairo , Yu Lumeng J. , Khan Atif , Haffty Bruce , Goydos James S. , Chen Suzie
Published: December 2013

Gain of function of the neuronal receptor, metabotropic glutamate receptor 1 (Grm1), was sufficient to induce melanocytic transformation in vitro and spontaneous melanoma development in vivo when ectopically expressed in melanocytes. The human form of this receptor, GRM1, has been shown to be ectopically expressed in a subset of human melanomas but not benign nevi or normal melanocytes, suggesting that misregulation of GRM1 is involved in the pathogenesis of certain human melanomas. Sustained stimulation of Grm1 by the ligand, glutamate, is required for the maintenance of transformed phenotypes in vitro and tumorigenicity in vivo. In this study, we investigate the mechanism of an inhibitor of glutamate release, riluzole, on human melanoma cells that express metabotropic glutamate receptor 1 (GRM1). Various in vitro assays conducted show that inhibition of glutamate release in several human melanoma cell lines resulted in an increase of oxidative stress and DNA damage response markers.
Prevalence, Serovars and Antimicrobial Susceptibility ofSalmonellaspp. from Wild and Domestic Green Iguanas (Iguana iguana) inGrenada, West Indies
Authors: Sylvester W. R. B. , Amadi V. , Pinckney R. , Macpherson C. N. L. , McKibben J. S. , Bruhl‐Day R. , Johnson R. , Hariharan H.
Published: December 2013

Cloacal swabs from 62 green iguanas (Iguana iguana), including 47 wild and 15 domestic ones from five parishes ofGrenada, were sampled during a 4‐month period of January to April 2013 and examined by enrichment and selective culture for the presence ofSalmonellaspp. Fifty‐five per cent of the animals were positive, and eight serovars ofSalmonellawere isolated. The most common serovar wasRubislaw (58.8%), a serovar found recently in many cane toads inGrenada, followed byOranienburg (14.7%), a serovar that has been causing serious human disease outbreaks inJapan. SerovarIV:48:g,z51:‐ (formerly,S. Marina) highly invasive and known for serious infections in children in theUnitedStates, constituted 11.8% of the isolates, all of them being from domestic green iguanas.SalmonellaNewport, a serovar recently found in a blue land crab inGrenada, comprised 11.8% of the isolates from the green iguanas. The remaining four less frequent serovars included S. Javiana and S. Glostrup. Antimicrobial susceptibility tests conducted by a disc diffusion method against amoxicillin–clavulanic acid, ampicillin, cefotaxime, ceftazidime, ciprofloxacin, enrofloxacin, gentamicin, nalidixic acid, streptomycin, tetracycline and trimethoprim–sulfamethoxazole showed that drug resistance is minimal, with intermediate susceptibility, mainly to streptomycin, tetracycline and cefotaxime. This is the first report of isolation and antimicrobial susceptibilities of variousSalmonellaserovars from wild and domestic green iguanas inGrenada,WestIndies.
Modeling and Analysis of an Electrically Actuated Microbeam Based on Nonclassical Beam Theory
Authors: Belardinelli Pierpaolo , Lenci Stefano , Brocchini Maurizio
Published: December 2013

This work investigates the mechanical behavior of a clamped-clamped microbeam modeled within the framework of the strain-gradient elasticity theory. The governing equation of motion gives proper account of both the effect of the nonlinear midplane stretching and of an applied axial load. An electric-voltage difference, introducing into the model a further source of nonlinearity, is considered, including also a correction term for fringing field effects. The electric force acting on the microbeam is rearranged by means of the Chebyshev method, verifying the accuracy of the proposed approximation. The results show that a uniform error on the whole domain can be achieved. The static solution is obtained by a numerical differential quadrature method. The paper looks into the variation of the maximal deflection of the microbeam with respect to several parameters. Study of the pull-in limit on the high-order material parameters introduced by the nonclassical approach and a comparison with respect to the classical beam theory are also carried out. The numerical simulation indicates that the static response is larger, affected by the use of a nonclassical theory near the pull-in instability regime. The dynamical problem is, finally, analyzed, deriving the multi degree-of-freedom problem through a Galerkin-based approach. The study on the single degree-of-freedom model enables us to note the large influence of the nonlinear terms.
Sequential-Digital Image Correlation for Mapping Human Posterior Sclera and Optic Nerve Head Deformation
Authors: Pyne Jeffrey D. , Genovese Katia , Casaletto Luciana , Vande Geest Jonathan P.
Published: December 2013

Optic nerve head (ONH) deformations may be involved in the onset or further development of glaucoma, including in patients with relatively normal intraocular pressures (IOPs). Characterizing posterior scleral deformations over physiological pressures may provide a better understanding of how changes in IOP lead to changes in the mechanical environment of the ONH and possibly retinal ganglion cell death. Pressure inflation measurement test protocols are commonly used to measure deformation of the peripapillary sclera with full-field noncontact optical methods. The purpose of this work was to develop and validate a new sequential 3D digital image correlation (S-DIC) approach for quantification of posterior scleral pressure induced deformation that improves z (in-depth) resolution of the DIC measurement without losing in-plane sensitivity, while also being able to contour and map deformations of the complex-shaped ONH. Our approach combines two orthogonal axes of parallax with standard 3D DIC methods using a single high-resolution camera. The enhanced capabilities of S-DIC with respect to standard 3D DIC has been demonstrated by carrying out a complete benchmark for shape, deformation, and strain measurement on an object of known complex geometry. Our S-DIC method provided a reconstruction accuracy of 0.17% and an uncertainty in z-position measurement of 8 μm. The developed methodology has also been applied to a human posterior scleral shell, including the full peripapillary sclera and optic nerve. The relatively inexpensive S-DIC approach may provide new information on the biomechanical deformations of the optic nerve head and, thus, the death of retinal ganglion cells in primary open angle glaucoma.
Subject-Specific Finite Element Modeling of the Tibiofemoral Joint Based on CT, Magnetic Resonance Imaging and Dynamic Stereo-Radiography Data in Vivo
Authors: Carey Robert E. , Zheng Liying , Aiyangar Ameet K. , Harner Christopher D. , Zhang Xudong
Published: December 2013

In this paper, we present a new methodology for subject-specific finite element modeling of the tibiofemoral joint based on in vivo computed tomography (CT), magnetic resonance imaging (MRI), and dynamic stereo-radiography (DSX) data. We implemented and compared two techniques to incorporate in vivo skeletal kinematics as boundary conditions: one used MRI-measured tibiofemoral kinematics in a nonweight-bearing supine position and allowed five degrees of freedom (excluding flexion-extension) at the joint in response to an axially applied force; the other used DSX-measured tibiofemoral kinematics in a weight-bearing standing position and permitted only axial translation in response to the same force. Verification and comparison of the model predictions employed data from a meniscus transplantation study subject with a meniscectomized and an intact knee. The model-predicted cartilage-cartilage contact areas were examined against “benchmarks” from a novel in situ contact area analysis (ISCAA) in which the intersection volume between nondeformed femoral and tibial cartilage was characterized to determine the contact. The results showed that the DSX-based model predicted contact areas in close alignment with the benchmarks, and outperformed the MRI-based model: the contact centroid predicted by the former was on average 85% closer to the benchmark location. The DSX-based FE model predictions also indicated that the (lateral) meniscectomy increased the contact area in the lateral compartment and increased the maximum contact pressure and maximum compressive stress in both compartments. We discuss the importance of accurate, task-specific skeletal kinematics in subject-specific FE modeling, along with the effects of simplifying assumptions and limitations.
Posture and Movement Classification: The Comparison of Tri-Axial Accelerometer Numbers and Anatomical Placement
Authors: Fortune Emma , Lugade Vipul A. , Kaufman Kenton R.
Published: December 2013

Patient compliance is important when assessing movement, particularly in a free-living environment when patients are asked to don their own accelerometers. Reducing the number of accelerometers could increase patient compliance. The aims of this study were (1) to determine and compare the validity of different accelerometer combinations and placements for a previously developed posture and dynamic movement identification algorithm. Custom-built activity monitors, each containing one tri-axial accelerometer, were placed on the ankles, right thigh, and waist of 12 healthy adults. Subjects performed a protocol in the laboratory including static orientations of standing, sitting, and lying down, and dynamic movements of walking, jogging, transitions between postures, and fidgeting to simulate free-living activity. When only one accelerometer was used, the thigh was found to be the optimal placement to identify both movement and static postures, with a misclassification error of 10%, and demonstrated the greatest accuracy for walking/fidgeting and jogging classification with sensitivities and positive predictive value (PPVs) greater than 93%. When two accelerometers were used, the waist-thigh accelerometers identified movement and static postures with greater accuracy than the thigh-ankle accelerometers (with a misclassification error of 11% compared to 17%). However, the thigh-ankle accelerometers demonstrated the greatest accuracy for walking/ fidgeting and jogging classification with sensitivities and PPVs greater than 93%. Movement can be accurately classified in healthy adults using tri-axial accelerometers placed on one or two of the following sites: waist, thigh, or ankle. Posture and transitions require an accelerometer placed on the waist and an accelerometer placed on the thigh.
Impact of surface treatments on high-κ dielectric integration with Ga-polar and N-polar GaN
Authors: English Caroline R. , Wheeler Virginia D. , Garces Nelson Y. , Nepal Neeraj , Nath Anindya , Hite Jennifer K. , Mastro Michael A. , Eddy Charles R.
Published: December 2013

Gallium- and nitrogen-polar GaN surfaces are subjected to a variety of pretreatments, including oxidation, before the application of high-κ dielectrics by atomic layer deposition (ALD) in order to assess the “best” preparation of smooth, clean, and electrically high-performing dielectric semiconductor interfaces. In terms of topographical and chemical cleanliness, a pretreatment with a wet chemical piranha etch (H2SO4:H2O2) was found to be optimum for both surfaces, and additionally, (NH4)2S is effective for N-polar surfaces. Both thermal and plasma oxidations were employed for controlled growth of native oxides. For Ga-polar surfaces, all native oxides were as smooth as pretreated surfaces, while for N-polar surfaces, all native oxides are much rougher except for very short, high temperature oxidations. ALD Al2O3 films on Ga-polar surfaces are smoother for pretreated surfaces than for as-received surfaces, whereas for N-polar surfaces the opposite is true. In general, ALD HfO2 films on Ga-polar surfaces are rougher (0.8 nm rms) than Al2O3 films (0.1 nm rms), whereas for piranha treated N-polar surfaces, HfO2 films are smoother than Al2O3 films. For Ga-polar surfaces, capacitance–voltage measurements of simple Al2O3 (measured κ = 9) capacitors show the smallest hysteresis for unintentionally oxidized surfaces (0.37 V), whereas simple HfO2 (measured κ = 14) capacitors show the smallest hysteresis for a thermal GaOx at the interface (0.1 V). In both cases, the thicker the GaOx at the interface the larger the negative threshold voltage shift—suggesting an electron trap. Calculated total trapped charges associated with the dielectrics range from 3.2 × 1011 cm−2 (for HfO2 on thermally oxidized GaN) to 1 × 1012 cm−2 for Al2O3 on thermally oxidized GaN and HfO2 on plasma oxidized GaN. Finally, the leakage current density for nearly all capacitors is <10−5 A-cm−2 at +8 V bias.
On the reliability of nanoindentation hardness of Al2O3 films grown on Si-wafer by atomic layer deposition
Authors: Liu Xuwen , Haimi Eero , Hannula Simo-Pekka , Ylivaara Oili M. E. , Puurunen Riikka L.
Published: December 2013

The interest in applying thin films on Si-wafer substrate for microelectromechanical systems devices by using atomic layer deposition (ALD) has raised the demand on reliable mechanical property data of the films. This study aims to find a quick method for obtaining nanoindentation hardness of thin films on silicon with improved reliability. This is achieved by ensuring that the film hardness is determined under the condition that no plastic deformation occurs in the substrate. In the study, ALD Al2O3 films having thickness varying from 10 to 600 nm were deposited on a single-side polished silicon wafer at 300 °C. A sharp cube-corner indenter was used for the nanoindentation measurements. A thorough study on the Si-wafer reference revealed that at a specific contact depth of about 8 nm the wafer deformation in loading transferred from elastic to elastic–plastic state. Furthermore, the occurrence of this transition was associated with a sharp increase of the power-law exponent, m, when the unloading data were fitted to a power-law relation. Since m is only slightly material dependent and should fall between 1.2 and 1.6 for different indenter geometry having elastic contact to common materials, it is proposed that the high m values are the results from the inelastic events during unloading. This inelasticity is linked to phase transformations during pressure releasing, a unique phenomenon widely observed in single crystal silicon. Therefore, it is concluded that m could be used to monitor the mechanical state of the Si substrate when the whole coating system is loaded. A suggested indentation depth range can then be assigned to each film thickness to provide guidelines for obtaining reliable property data. The results show good consistence for films thicker than 20 nm and the nanoindentation hardness is about 11 GPa independent of film thickness.
Nanoscale-resolved near-infrared photoabsorption spectroscopy and imaging of individual gallium antimonide quantum dots
Authors: Naruse Nobuyasu , Nakamura Yoshiaki , Mera Yutaka , Ichikawa Masakazu , Maeda Koji
Published: December 2013

Near-infrared photoabsorption spectra of individual dots of gallium antimonide (GaSb) epitaxially grown on a silicon substrate were investigated by nanoscale-resolved spectroscopic measurements and by imaging through scanning tunneling microscopy (STM). With a short acquisition time of a few minutes, photomodulated current spectroscopy (STM-PMCS), based on STM without a tunneling current, showed that our samples exhibited photoabsorption with a peak centered at about 0.78 eV. Spatial variations in STM-PMCS imaging arose from differences in dot sizes. However, the STM-PMCS images were insufficiently unambiguous to permit interpretation of the signal origin in the tunneling region, because a tip-expansion effect could have arisen through photointensity modulation. Spectral features revealed by STM-based electric field modulation spectroscopy (STM-EFMS), which is free of the tip-expansion effect, showed a significant size-dependent energy shift at around 0.8 eV that was attributed to a quantum-confinement effect on the bound states of the GaSb quantum dots. Our approach, which utilizes the merits of both STM-PMCS and STM-EFMS, is efficient in elucidating the photoabsorption properties of nanoscale objects.
Atomic layer deposition of HfxAlyCz as a work function material in metal gate MOS devices
Authors: Lee Albert , Fuchigami Nobi , Pisharoty Divya , Hong Zhendong , Haywood Ed , Joshi Amol , Mujumdar Salil , Bodke Ashish , Karlsson Olov , Kim Hoon , Choi Kisik , Besser Paul
Published: December 2013

As advanced silicon semiconductor devices are transitioning from planar to 3D structures, new materials and processes are needed to control the device characteristics. Atomic layer deposition (ALD) of HfxAlyCz films using hafnium chloride and trimethylaluminum precursors was combined with postdeposition anneals and ALD liners to control the device characteristics in high-k metal-gate devices. Combinatorial process methods and technologies were employed for rapid electrical and materials characterization of various materials stacks. The effective work function in metal–oxide–semiconductor capacitor devices with the HfxAlyCz layer coupled with an ALD HfO2 dielectric was quantified to be mid-gap at ∼4.6 eV. Thus, HfxAlyCz is a promising metal gate work function material that allows for the tuning of device threshold voltages (Vth) for anticipated multi-Vth integrated circuit devices.
Marine mammal audibility of selected shallow-water survey sources
Authors: MacGillivray Alexander O. , Racca Roberto , Li Zizheng
Published: December 2013

Most attention about the acoustic effects of marine survey sound sources on marine mammals has focused on airgun arrays, with other common sources receiving less scrutiny. Sound levels above hearing threshold (sensation levels) were modeled for six marine mammal species and seven different survey sources in shallow water. The model indicated that odontocetes were most likely to hear sounds from mid-frequency sources (fishery, communication, and hydrographic systems), mysticetes from low-frequency sources (sub-bottom profiler and airguns), and pinnipeds from both mid- and low-frequency sources. High-frequency sources (side-scan and multibeam) generated the lowest estimated sensation levels for all marine mammal species groups.
Dietary Therapy Mitigates Persistent Wake Deficits Caused by Mild Traumatic Brain Injury
Authors: Lim Miranda M. , Elkind Jaclynn , Xiong Guoxiang , Galante Ray , Zhu Jingxu , Zhang Lin , Lian Jie , Rodin Julianna , Kuzma Nicholas N. , Pack Allan I. , Cohen Akiva S.
Published: December 2013

Mild traumatic brain injury causes persistent deficits in wakefulness in mice, which are mitigated by a dietary therapy containing branched-chain amino acids.
Stewardship Practices of U.S. Biobanks
Authors: Henderson Gail E. , Edwards Teresa P. , Cadigan R. Jean , Davis Arlene M. , Zimmer Catherine , Conlon Ian , Weiner Bryan J.
Published: December 2013

Most U.S. biobanks do not create ongoing relationships with contributors but do practice stewardship over storing and sharing of specimens.
Cytokeratin 8 Is an Epithelial Cell Receptor for Pet, a Cytotoxic Serine Protease Autotransporter of
Enterobacteriaceae
Authors: Nava-Acosta Raul , Navarro-Garcia Fernando
Published: December 2013

The group of proteins known as serine protease autotransporters of
Enterobacteriaceae
(SPATE) is a growing family of serine proteases secreted to the external milieu by the type V secretion system. Pet toxin and some other SPATE belong to the class 1 cytotoxic SPATE, which have comparable protease strength on fodrin. Pet is internalized and is directed to its intracellular substrate by retrograde transport. However, the epithelial cell receptor for Pet has yet to be identified. We show that Pet has affinity for the epithelial cell surface until the saturation of the binding sites at 100 nM Pet. Affinity column assays and matrix-assisted laser desorption ionization–time of flight (MALDI-TOF) analysis identified a cytokeratin (CK8) which directly binds to Pet, and both proteins colocalized on the cell surface. Interestingly, CK8 is not present in kidney cell lines, which are not susceptible to Pet. Inhibition experiments by using anti-CK8 and
ck8
small interfering RNA (siRNA) blocked the cytotoxic effect induced by Pet, while exogenous CK8 expression in kidney cells made them susceptible to Pet intoxication. Recombinant CK8 showed a Pet-binding pattern similar to that seen by using fixed cells. Remarkably, Pet colocalized with CK8 and clathrin at early times (receptor-mediated endocytosis), and subsequently, Pet colocalized with CK8 and Rab5b in the early endosomes. These data support the idea that CK8 is an important receptor for Pet on epithelial cells for starting its cytotoxic effects. These data suggest that therapeutics that block Pet-CK8 interaction may improve outcome of diseases caused by Pet-secreting
Enterobacteriaceae
such as enteroaggregative
Escherichia coli
.

IMPORTANCE
Receptor-ligand binding is one mechanism by which cells sense and respond to external cues. Receptors may also be utilized by toxins to mediate their own internalization. Pet toxin is secreted by enteroaggregative
Escherichia coli
, an organism that causes persistent diarrhea in children, traveler’s diarrhea, and acute and persistent diarrhea in patients with HIV. Pet is a member of the family of serine protease autotransporters of
Enterobacteriaceae
(SPATE). SPATE in different pathogens are virulence factors, and Pet belongs to the class 1 cytotoxic SPATE, which have comparable protease strength on their biological substrate, fodrin (a cytoskeletal protein important for maintaining cell viability). To cleave fodrin, Pet enters the cells by clathrin-mediated endocytosis. This mechanism includes receptor-mediated endocytosis (a receptor-ligand complex triggers the endocytosis). We show that CK8 is an important receptor for Pet on epithelial cells and that it may be useful for identifying molecules that block the interaction of CK8 with Pet.
The Histone Code of Toxoplasma gondii Comprises Conserved and Unique Posttranslational Modifications
Authors: Nardelli Sheila C. , Che Fa-Yun , Silmon de Monerri Natalie C. , Xiao Hui , Nieves Edward , Madrid-Aliste Carlos , Angel Sergio O. , Sullivan William J. , Angeletti Ruth H. , Kim Kami , Weiss Louis M.
Published: December 2013

Epigenetic gene regulation has emerged as a major mechanism for gene regulation in all eukaryotes. Histones are small, basic proteins that constitute the major protein component of chromatin, and posttranslational modifications (PTM) of histones are essential for epigenetic gene regulation. The different combinations of histone PTM form the histone code for an organism, marking functional units of chromatin that recruit macromolecular complexes that govern chromatin structure and regulate gene expression. To characterize the repertoire of
Toxoplasma gondii
histone PTM, we enriched histones using standard acid extraction protocols and analyzed them with several complementary middle-down and bottom-up proteomic approaches with the high-resolution Orbitrap mass spectrometer using collision-induced dissociation (CID), higher-energy collisional dissociation (HCD), and/or electron transfer dissociation (ETD) fragmentation. We identified 249 peptides with unique combinations of PTM that comprise the
T. gondii
histone code.
T. gondii
histones share a high degree of sequence conservation with human histones, and many modifications are conserved between these species. In addition,
T. gondii
histones have unique modifications not previously identified in other species. Finally,
T. gondii
histones are modified by succinylation, propionylation, and formylation, recently described histone PTM that have not previously been identified in parasitic protozoa. The characterization of the
T. gondii
histone code will facilitate in-depth analysis of how epigenetic regulation affects gene expression in pathogenic apicomplexan parasites and identify a new model system for elucidating the biological functions of novel histone PTM.

IMPORTANCE
Toxoplasma gondii
is among the most common parasitic infections in humans. The transition between the different stages of the
T. gondii
life cycle are essential for parasite virulence and survival. These differentiation events are accompanied by significant changes in gene expression, and the control mechanisms for these transitions have not been elucidated. Important mechanisms that are involved in the control of gene expression are the epigenetic modifications that have been identified in several eukaryotes.
T. gondii
has a full complement of histone-modifying enzymes, histones, and variants. In this paper, we identify over a hundred PTM and a full repertoire of PTM combinations for
T. gondii
histones, providing the first large-scale characterization of the
T. gondii
histone code and an essential initial step for understanding how epigenetic modifications affect gene expression and other processes in this organism.
Innocent left ventricular outflow tract membrane masquerading as vegetation
Authors: Javed Arshad , Zalawadiya Sandip , Cardozo Shaun , Afonso Luis
Published: December 2013

Innocent left ventricular outflow tract (LVOT) membranes are a rare entity and found incidentally on echocardiography. The authors report a case of innocent LVOT membrane in a patient who was admitted with ischaemic stroke. Initial transthoracic echocardiography showed a possible valvular vegetation which was thought to be the cause of embolic stroke. Anticoagulation with coumadin and antibiotics were started. Subsequent Transesophageal echocardiography showed that it was more consistent with innocent LVOT membrane and not vegetation. Anticoagulation and antibiotics were discontinued, and on a follow-up over 5 years later, the membrane was stable in size and location without any complications.
The prevalence of latex sensitisation and allergy and associated risk factors among healthcare workers using hypoallergenic latex gloves at King Edward VIII Hospital, KwaZulu-Natal South Africa: a cross-sectional study
Authors: Phaswana Shumani Makwarela , Naidoo Saloshni
Published: December 2013

Objectives

The present study describes latex sensitisation and allergy prevalence and associated factors among healthcare workers using hypoallergenic latex gloves at King Edward VIII Hospital in KwaZulu-Natal, South Africa.

Design

Cross-sectional study.

Setting

A tertiary hospital in eThekwini municipality, KwaZulu-Natal, South Africa.

Participants

600 healthcare workers were randomly selected and 501 (337 exposed and 164 unexposed) participated. Participants who were pregnant, with less than 1 year of work as a healthcare worker and a history of anaphylactic reaction were excluded from the study.

Primary and secondary outcome measures

Latex sensitisation and latex allergy were the outcome of interest and they were successfully measured.

Results

The prevalence of latex sensitisation and allergy was observed among exposed workers (7.1% and 5.9%) and unexposed workers (3.1% and 1.8%). Work-related allergy symptoms were significantly higher in exposed workers (40.9%, p<0.05). Duration of employment was inversely associated with latex allergy (OR 0.9; 95% CI 0.8 to 0.9). The risk of latex sensitisation (OR 4.2; 95% CI 1.2 to 14.1) and allergy (OR 5.1; 95% CI 1.2 to 21.2) increased with the exclusive use of powder-free latex gloves. A dose–response relationship was observed for powdered latex gloves (OR 1.1; 95% CI 1.0 to 1.2). Atopy (OR 1.5; 95% CI 0.7 to 3.3 and OR 1.4; 95% CI 0.6 to 3.2) and fruit allergy (OR 2.3; 95% CI 0.8 to 6.7 and OR 3.1; 95% CI 1.1 to 9.2) also increased the risk of latex sensitisation and allergy.

Conclusions

This study adds to previous findings that healthcare workers exposed to hypoallergenic latex gloves are at risk for developing latex sensitisation highlighting its importance as an occupational hazard in healthcare. More research is needed to identify the most cost effective way of implementing a latex-free environment in resource-limited countries, such as South Africa. In addition more cohort analysis is required to better understand the chronicity of illness and disability associated with latex allergy.
Differences in research funding for women scientists: a systematic comparison of UK investments in global infectious disease research during 1997–2010
Authors: Head Michael G , Fitchett Joseph R , Cooke Mary K , Wurie Fatima B , Atun Rifat
Published: December 2013

Objectives

There has not previously been a systematic comparison of awards for research funding in infectious diseases by sex. We investigated funding awards to UK institutions for all infectious disease research from 1997 to 2010, across disease categories and along the research and development continuum.

Design

Systematic comparison.

Methods

Data were obtained from several sources for awards from the period 1997 to 2010 and each study assigned to—disease categories; type of science (preclinical, phases I–III trials, product development, implementation research); categories of funding organisation. Fold differences and statistical analysis were used to compare total investment, study numbers, mean grant and median grant between men and women.

Results

6052 studies were included in the final analysis, comprising 4357 grants (72%) awarded to men and 1695 grants (28%) awarded to women, totalling £2.274 billion. Of this, men received £1.786 billion (78.5%) and women £488 million (21.5%). The median value of award was greater for men (£179 389; IQR £59 146–£371 977) than women (£125 556; IQR £30 982–£261 834). Awards were greater for male principal investigators (PIs) across all infectious disease systems, excepting neurological infections and sexually transmitted infections. The proportion of total funding awarded to women ranged from 14.3% in 1998 to 26.8% in 2009 (mean 21.4%), and was lowest for preclinical research at 18.2% (£285.5 million of £1.573 billion) and highest for operational research at 30.9% (£151.4 million of £489.7 million).

Conclusions

There are consistent differences in funding received by men and women PIs: women have fewer funded studies and receive less funding in absolute and in relative terms; the median funding awarded to women is lower across most infectious disease areas, by funder, and type of science. These differences remain broadly unchanged over the 14-year study period.
Return to work following unintentional injury: a prospective follow-up study
Authors: Hepp Urs , Schnyder Ulrich , Hepp-Beg Sofia , Friedrich-Perez Josefina , Stulz Niklaus , Moergeli Hanspeter
Published: December 2013

Objective

The aim of this study was to predict time off work following unintentional injuries due to accidents leading to hospital admission.

Design

Prospective 6-month follow-up study.

Setting

Department of Trauma Surgery of a University Hospital.

Participants

Consecutively recruited victims of unintentional injuries (n=221) hospitalised for a minimum of 32 h including two consecutive nights. All the participants were aged 18–65 years and were able to participate in an assessment within 30 days of the accident.

Main outcome measures

Interview-assessed number of days off work during the 6 months immediately following the accident.

Results

The patients’ subjective appraisals of (1) accident severity and (2) their ability to cope with the resulting injury and its job-related consequences predicted time off work following the accident beyond the impact of the objective severity of their injury and the type of accident involved.

Conclusions

The patients’ subjective appraisals of the accident severity and of their ability to cope with its consequences are highly relevant for return to work after accidents. Extending the findings from previous studies on severely injured and otherwise preselected accident victims, this seems to apply to the whole spectrum of patients hospitalised with unintentional injuries.
The Variable Rate Intravenous Insulin Infusion Protocol
Authors: Collard Benjamin , Sturgeon Jonathan , Patel Natasha , Asharia Shabbar
Published: December 2013

Insulin use among inpatients is high and associated with severe and regular medication errors. An initial baseline audit showed a wide variation in the prescription of intravenous insulin within the trust. These included variation in the choice of fluid prescribed, electrolyte levels not consistently checked, handwritten illegible prescriptions, and varying parameters set for adjustment of the prescription.

A Variable Rate Intravenous Insulin Infusion protocol (VRIII)) was introduced to standardize intravenous insulin prescription throughout the trust by all members of the clinical team. We looked at and measured uptake and effects of the VRIII protocol in improving standardization of insulin prescription for inpatients on insulin at St George's NHS trust. The protocol was uploaded to the intranet to allow access 24 hours a day and the staff educated about it.

The VRIII protocol was routinely used successfully throughout the trust. Any initial problems were addressed through education of clinical staff. The protocol has shown decreased prescribing and administrative errors, whilst demonstrating good glucose and electrolyte control.

Use of a standardized protocol helps reduce medication errors and demonstrates good glycaemic control. Regular and continued education of clinical staff is necessary to maintain its efficacy.
Improvement in institutional protocols leads to decreased mortality in patients with haemodynamically unstable pelvic fractures
Authors: Cheng Mina , Cheung Moon-Tong , Lee Kin-Yan , Lee Kin-Bong , Chan Susan-C H , Wu Amy-C Y , Chow Yu-Fat , Chang Annice-M L , Ho Hiu-Fai , Yau Kelvin-K W
Published: December 2013

Background

The mortality rate in patients with haemodynamically unstable pelvic fractures is as high as 40–60%. In recent years, angioembolisation and pelvic packing have been introduced as part of a multimodality treatment for these patients. Protocol-driven management has been shown to improve outcomes.

Patients and methods

This is a Level III retrospective cohort study of patients suffering from unstable pelvic fractures from 1 January 1996 to 30 September 2011. The aim of the study was to review our results, particularly in terms of mortality through the evolution of three phases of treatment protocols: preangiography, angiography and pelvic packing.

Results

The overall 30-day mortality rate for all patients was 47.2%, with a rate of 63.5% in the preangiography phase, 42.1% in the angiography phase and 30.6% in the pelvic packing phase. Multivariate logistic regression analysis identified the use of retroperitoneal packing as a significant independent predictive factor for 24 h mortality.

Conclusions

Our results showed an improvement in patient survival with sequential protocols over the study period, during which we incorporated a multidisciplinary approach to managing these complicated pelvic fractures. The results strongly suggest that retroperitoneal packing should be highly recommended for bleeding subsequent to pelvic fracture, in addition to other modalities of treatment.
Ketamine as a possible cause of cirrhosis in a patient with chronic pain
Authors: Bevan Roisin , Burke Denis
Published: December 2013

Ketamine has been typically administered in short-term, few doses in the clinical setting of acute pain. Its hallucinogenic side effects have made it popular as a recreational drug. Reports of urological, biliary and liver abnormalities have been reported, mainly in cases of abuse. It is now increasingly used for chronic pain conditions, and here we report liver abnormalities and ultimately cirrhosis in an adult on regular ketamine for chronic facial pain. Abnormal liver function tests were detected incidentally, and with no other cause for liver disease found, liver biopsy was performed. This showed fibrosis with incomplete cirrhosis.
Exercise capacity and paroxysmal atrial fibrillation in patients with hypertrophic cardiomyopathy
Authors: Azarbal Farnaz , Singh Maneesh , Finocchiaro Gherardo , Le Vy-Van , Schnittger Ingela , Wang Paul , Myers Jonathan , Ashley Euan , Perez Marco
Published: December 2013

Background

Atrial fibrillation (AF) is the most common arrhythmia among patients with hypertrophic cardiomyopathy (HCM). The relationship between paroxysmal AF and exercise capacity in this population is incompletely understood.

Methods

Patients with HCM underwent symptom-limited cardiopulmonary testing with expired gas analysis at Stanford Hospital between October 2006 and October 2012. Baseline demographics, medical histories and resting echocardiograms were obtained for all subjects. Diagnosis of AF was established by review of medical records and baseline ECG. Those with paroxysmal AF were in sinus rhythm at the time of cardiopulmonary testing with expired gas analysis. Exercise intolerance was defined as peak VO2<20 mL/kg/min. We used multivariate logistic regression to evaluate the association between exercise intolerance and paroxysmal AF.

Results

Among the 265 patients recruited, 55 had AF (28 paroxysmal and 27 permanent). Compared with those without AF, subjects with paroxysmal AF were older, more likely to use antiarrhythmic and anticoagulant medications, and had larger left atria. Patients with paroxysmal AF achieved lower peak VO2 (21.9±9.2 mL/kg/min vs 26.9±10.8 mL/kg/min, p=0.02) and were more likely to have exercise intolerance (61% vs 28%, p<0.001) compared with those without AF. After adjustment for age, sex and body mass index (BMI) exercise intolerance remained significantly associated with paroxysmal AF (OR 4.65, 95% CI 1.83 to 11.83, p=0.001).

Conclusions

Patients with HCM and paroxysmal AF demonstrate exercise intolerance despite being in sinus rhythm at the time of exercise testing.
Patterns of vulnerability to non-fatal injuries in Sudan: initial evidence from a national cross-sectional survey
Authors: Abdalla Safa
Published: December 2013

Background

Successful injury prevention requires identification and targeting of particularly vulnerable groups. Little is known about injury vulnerability patterns in Sudan. This paper aimed to fill this gap using survey data.

Methods

Data from the Sudan Household Health Survey were used. This was a national cross-sectional interview survey of 83 510 individuals selected by multistage cluster random sampling. Multivariable Poisson regression was used to investigate the association of cause-specific injury that received care by traditional healers, outpatient care and inpatient care, and those that received only inpatient care, with age, gender, area of residence (urban or rural), socioeconomic status and education. Relevant interactions were tested.

Results

Independent of other sociodemographic variables, men were at higher risk of road traffic injury (prevalence ratio (PR): 3.3 95% CI 2.4 to 4.7), falls (PR: 1.5, 95% CI 1.3 to 1.9), assault (PR: 3.0 95% CI 1.8–5) and mechanical injury (PR: 2.0 95% CI 1.2 to 3.1) that received any form of healthcare. Those aged 65 years and over also had the highest risk of those injury causes, while children under 5 years were the most likely to suffer burn injuries. Socioeconomic status was associated with assault (PR for the richest group 0.4 95% CI 0.2 to 0.8). Vulnerability patterns for injury that received inpatient care were fairly similar for some causes.

Conclusions

In Sudan, existing disease prevention and health promotion programmes should expand to target men, children under 5 years, elderly people and those of low socioeconomic status with injury prevention interventions. Further research is needed to investigate the context-specific proximal risk factors that shape the various vulnerability patterns observed.