bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of Volume and Site of Blood Draw on Blood Culture Results
Authors: Gonsalves Wilson I. , Cornish Nancy , Moore Michael , Chen Aimin , Varman Meera
Published: October 2009

Blood culture contamination greatly affects clinical decisions. Hence, it is of interest to assess the influence of factors such as the volume of blood drawn and the site of blood draw on the rates of blood culture contamination. In a retrospective study, blood cultures from infants and children up to 18 years of age who had at least one positive blood culture during the year 2006 were analyzed for their volume of blood drawn, patient's weight, site of blood draw used, and blood culture results. Blood cultures were deemed adequate collections if they contained an appropriate weight-related volume of blood. Moreover, blood culture results were categorized as true pathogens, contaminants, and negative cultures; these were then compared and analyzed with respect to their volume and site of blood draw. A total of 5,023 blood cultures were collected during 2006, of which 843 were analyzed. There were 306 (36%) positive cultures among the 843 cultures analyzed. Of the 306 positive cultures, 98 (32%) were contaminants and 208 (68%) cultures grew significant pathogens. Thirty-five percent of the contaminant cultures had adequate volume compared to 60% in the true bacteremia group (
P
< 0.001). Also, of the 843 cultures, the rates of contamination among the different sites of blood draw were as follows: peripheral venipuncture, 36%; arterial, 10%; and central venous access, 7% (
P
= 0.155). The rate of contamination was higher with lower blood volumes, and there was no significant difference in the rates of contamination among the different sites of blood draw.
The Cytoplasmic Domain of Human Immunodeficiency Virus Type 1 Transmembrane Protein gp41 Harbors Lipid Raft Association Determinants
Authors: Yang Polung , Ai Li-Shuang , Huang Shu-Chen , Li Hsiao-Fen , Chan Woan-Eng , Chang Chih-Wei , Ko Chiung-Yuan , Chen Steve S.-L.
Published: October 2009

The molecular basis for localization of the human immunodeficiency virus type 1 envelope glycoprotein (Env) in detergent-resistant membranes (DRMs), also called lipid rafts, still remains unclear. The C-terminal cytoplasmic tail of gp41 contains three membrane-interacting, amphipathic α-helical sequences, termed lentivirus lytic peptide 2 (LLP-2), LLP-3, and LLP-1, in that order. Here we identify determinants in the cytoplasmic tail which are crucial for Env's association with Triton X-100-resistant rafts. Truncations of LLP-1 greatly reduced Env localization in lipid rafts, and the property of Gag-independent gp41 localization in rafts was conserved among different strains. Analyses of mutants containing single deletions or substitutions in LLP-1 showed that the α-helical structure of the LLP-1 hydrophobic face has a more-critical role in Env-raft associations than that of the hydrophilic face. With the exception of a Pro substitution for Val-833, all Pro substitution and charge-inverting mutants showed wild-type virus-like one-cycle viral infectivity, replication kinetics, and Env incorporation into the virus. The intracellular localization and cell surface expression of mutants not localized in lipid rafts, such as the TM844, TM813, 829P, and 843P mutants, were apparently normal compared to those of wild-type Env. Cytoplasmic subdomain targeting analyses revealed that the sequence spanning LLP-3 and LLP-1 could target a cytoplasmic reporter protein to DRMs. Mutations of LLP-1 that affected Env association with lipid rafts also disrupted the DRM-targeting ability of the LLP-3/LLP-1 sequence. Our results clearly demonstrate that LLP motifs located in the C-terminal cytoplasmic tail of gp41 harbor Triton X-100-resistant raft association determinants.
Evasion of the Mucosal Innate Immune System by Herpes Simplex Virus Type 2
Authors: Peng Tao , Zhu Jia , Klock Alexis , Phasouk Khamsone , Huang Meei-Li , Koelle David M. , Wald Anna , Corey Lawrence
Published: October 2009

Understanding the mechanisms by which herpes simplex virus (HSV) evades host immune defenses is critical to defining new approaches for therapy and prevention. We performed transcriptional analyses and immunocytochemistry on sequential biopsy specimens of lesional tissue from the acute through the posthealing phases of recurrent mucocutaneous HSV-2 infection. Histological analysis of these biopsy specimens during the acute stage revealed a massive infiltration of T cells, as well as monocytes/macrophages, a large amount of myeloid, and a small number of plasmacytoid dendritic cells, in the dermis of these lesional biopsy specimens. Type I interferon (IFN-β and IFN-α) was poorly expressed and gamma IFN (IFN-γ) potently induced during time periods in which we detected abundant amounts of HSV-2 antigens and HSV-2 RNA. IFN-stimulated genes were also markedly upregulated, with expression patterns that more closely matched those in primary human fibroblasts treated by IFN-γ than those in fibroblasts treated by IFN-β. Transcriptional arrays of the same lesional biopsy sites during healing and at 2 and 4 weeks posthealing revealed no HSV nucleic acids or antigen; however, there was persistent expression of IFN-γ, with very low levels of IFN-β and IFN-α. The findings of extremely low levels of IFN-α and IFN-β, despite the presence of a large number of cells capable of synthesizing these substances, suggest a potent alteration in host defense during HSV-2 infection in vivo. HSV-2's blockade of the innate immune system's production of type I IFN may be a major factor in allowing the virus to break through host mucosal defenses.
Crystal Structure of a Novel Conformational State of the Flavivirus NS3 Protein: Implications for Polyprotein Processing and Viral Replication
Authors: Assenberg René , Mastrangelo Eloise , Walter Thomas S. , Verma Anil , Milani Mario , Owens Raymond J. , Stuart David I. , Grimes Jonathan M. , Mancini Erika J.
Published: October 2009

The flavivirus genome comprises a single strand of positive-sense RNA, which is translated into a polyprotein and cleaved by a combination of viral and host proteases to yield functional proteins. One of these, nonstructural protein 3 (NS3), is an enzyme with both serine protease and NTPase/helicase activities. NS3 plays a central role in the flavivirus life cycle: the NS3 N-terminal serine protease together with its essential cofactor NS2B is involved in the processing of the polyprotein, whereas the NS3 C-terminal NTPase/helicase is responsible for ATP-dependent RNA strand separation during replication. An unresolved question remains regarding why NS3 appears to encode two apparently disconnected functionalities within one protein. Here we report the 2.75-Å-resolution crystal structure of full-length Murray Valley encephalitis virus NS3 fused with the protease activation peptide of NS2B. The biochemical characterization of this construct suggests that the protease has little influence on the helicase activity and vice versa. This finding is in agreement with the structural data, revealing a single protein with two essentially segregated globular domains. Comparison of the structure with that of dengue virus type 4 NS2B-NS3 reveals a relative orientation of the two domains that is radically different between the two structures. Our analysis suggests that the relative domain-domain orientation in NS3 is highly variable and dictated by a flexible interdomain linker. The possible implications of this conformational flexibility for the function of NS3 are discussed.
Quantifying Differences in the Tempo of Human Immunodeficiency Virus Type 1 Subtype Evolution
Authors: Abecasis Ana B. , Vandamme Anne-Mieke , Lemey Philippe
Published: October 2009

Human immunodeficiency virus type 1 (HIV-1) genetic diversity, due to its high evolutionary rate, has long been identified as a main cause of problems in the development of an efficient HIV-1 vaccine. However, little is known about differences in evolutionary rate between different subtypes. In this study, we collected representative samples of the main epidemic subtypes and circulating recombinant forms (CRFs), namely, sub-subtype A1, subtypes B, C, D, and G, and CRFs 01_AE and 02_AG. We analyzed separate data sets for
pol
and
env
. We performed a Bayesian Markov chain Monte Carlo relaxed-clock phylogenetic analysis and applied a codon model to the resulting phylogenetic trees to estimate nonsynonymous (dN) and synonymous (dS) rates along each and every branch. We found important differences in the evolutionary rates of the different subtypes. These are due to differences not only in the dN rate but also in the dS rate, varying in roughly similar ways, indicating that these differences are caused by both different selective pressures (for dN rate) and the replication dynamics (for dS rate) (i.e., mutation rate or generation time) of the strains. CRF02_AG and subtype G had higher rates, while subtype D had lower dN and dS rates than the other subtypes. The dN/dS ratio estimates were also different, especially for the
env
gene, with subtype G showing the lowest dN/dS ratio of all subtypes.
Clathrin-Mediated Post-Golgi Membrane Trafficking in the Morphogenesis of Hepatitis Delta Virus
Authors: Huang Cheng , Chang Shin C. , Yang Hui-Chin , Chien Chung-Liang , Chang Ming-Fu
Published: October 2009

Clathrin is involved in the endocytosis and exocytosis of cellular proteins and the process of virus infection. We have previously demonstrated that large hepatitis delta antigen (HDAg-L) functions as a clathrin adaptor, but the detailed mechanisms of clathrin involvement in the morphogenesis of hepatitis delta virus (HDV) are not clear. In this study, we found that clathrin heavy chain (CHC) is a key determinant in the morphogenesis of HDV. HDAg-L with a single amino acid substitution at the clathrin box retained nuclear export activity but failed to interact with CHC and to assemble into virus-like particles. Downregulation of CHC function by a dominant-negative mutant or by short hairpin RNA reduced the efficiency of HDV assembly, but not the secretion of hepatitis B virus subviral particles. In addition, the coexistence of a cell-permeable peptide derived from the C terminus of HDAg-L significantly interfered with the intracellular transport of HDAg-L. HDAg-L, small HBsAg, and CHC were found to colocalize with the
trans
-Golgi network and were highly enriched on clathrin-coated vesicles. Furthermore, genotype II HDV, which assembles less efficiently than genotype I HDV does, has a putative clathrin box in its HDAg-L but interacted only weakly with CHC. The assembly efficiency of the various HDV genotypes correlates well with the CHC-binding activity of their HDAg-Ls and coincides with the severity of disease outcome. Thus, the clathrin box and the nuclear export signal at the C terminus of HDAg-L are potential new molecular targets for HDV therapy.
Apolipoprotein E but Not B Is Required for the Formation of Infectious Hepatitis C Virus Particles
Authors: Jiang Jieyun , Luo Guangxiang
Published: October 2009

Our previous studies have found that hepatitis C virus (HCV) particles are enriched in apolipoprotein E (apoE) and that apoE is required for HCV infectivity and production. Studies by others, however, suggested that both microsomal transfer protein (MTP) and apoB are important for HCV production. To define the roles of apoB and apoE in the HCV life cycle, we developed a single-cycle HCV growth assay to determine the correlation of HCV assembly with apoB and apoE expression, as well as the influence of MTP inhibitors on the formation of HCV particles. The small interfering RNA (siRNA)-mediated knockdown of apoE expression remarkably suppressed the formation of HCV particles. However, apoE expressed ectopically could restore the defect of HCV production posed by the siRNA-mediated knockdown of endogenous apoE expression. In contrast, apoB-specific antibodies and siRNAs had no significant effect on HCV infectivity and production, respectively, suggesting that apoB does not play a significant role in the HCV life cycle. Additionally, two MTP inhibitors, CP-346086 and BMS-2101038, efficiently blocked secretion of apoB-containing lipoproteins but did not affect HCV production unless apoE expression and secretion were inhibited. At higher concentrations, however, MTP inhibitors blocked apoE expression and secretion and consequently suppressed the formation of HCV particles. Furthermore, apoE was found to be sensitive to trypsin digestion and to interact with NS5A in purified HCV particles and HCV-infected cells, as demonstrated by coimmunoprecipitation. Collectively, these findings demonstrate that apoE but not apoB is required for HCV assembly, probably via a specific interaction with NS5A.
Heavily Isotype-Dependent Protective Activities of Human Antibodies against Vaccinia Virus Extracellular Virion Antigen B5
Authors: Benhnia Mohammed Rafii-El-Idrissi , McCausland Megan M. , Laudenslager John , Granger Steven W. , Rickert Sandra , Koriazova Lilia , Tahara Tomoyuki , Kubo Ralph T. , Kato Shinichiro , Crotty Shane
Published: October 2009

Antibodies against the extracellular virion (EV or EEV) form of vaccinia virus are an important component of protective immunity in animal models and likely contribute to the protection of immunized humans against poxviruses. Using fully human monoclonal antibodies (MAbs), we now have shown that the protective attributes of the human anti-B5 antibody response to the smallpox vaccine (vaccinia virus) are heavily dependent on effector functions. By switching Fc domains of a single MAb, we have definitively shown that neutralization in vitro—and protection in vivo in a mouse model—by the human anti-B5 immunoglobulin G MAbs is isotype dependent, thereby demonstrating that efficient protection by these antibodies is not simply dependent on binding an appropriate vaccinia virion antigen with high affinity but in fact requires antibody effector function. The complement components C3 and C1q, but not C5, were required for neutralization. We also have demonstrated that human MAbs against B5 can potently direct complement-dependent cytotoxicity of vaccinia virus-infected cells. Each of these results was then extended to the polyclonal human antibody response to the smallpox vaccine. A model is proposed to explain the mechanism of EV neutralization. Altogether these findings enhance our understanding of the central protective activities of smallpox vaccine-elicited antibodies in immunized humans.
Distinct Regulation of Hepatitis B Virus Biosynthesis by Peroxisome Proliferator-Activated Receptor γ Coactivator 1α and Small Heterodimer Partner in Human Hepatoma Cell Lines
Authors: Ondracek Caitlin R. , Reese Vanessa C. , Rushing Christel N. , Oropeza Claudia E. , McLachlan Alan
Published: October 2009

The human hepatoma cell lines HepG2 and Huh7 have been used extensively to study hepatitis B virus (HBV) transcription and replication. Both cell lines support transcription of the 3.5-kb viral pregenomic RNA and subsequent viral DNA synthesis by reverse transcription. The effects of the coactivator peroxisome proliferator-activated receptor γ coactivator 1α (PGC1α) and corepressor small heterodimer partner (SHP) on HBV transcription and replication mediated by nuclear receptors were examined in the context of individual nuclear receptors in nonhepatoma cells and in hepatoma cells in an attempt to determine the relative contribution of the various nuclear receptors to viral biosynthesis in the hepatoma cells. PGC1α and SHP modulated viral biosynthesis differently in the human hepatoma cell lines HepG2 and Huh7, indicating distinct modes of transcriptional regulation. Consistent with this suggestion, it appears that retinoid X receptor α/farnesoid X receptor α and liver receptor homolog 1 or estrogen-related receptor β (ERRβ) may contribute to the majority of the viral replication observed in HepG2 cells, whereas ERRα and ERRγ are probably responsible for the majority of viral biosynthesis in Huh7 cells. Therefore, this approach indicates that the transcriptional regulation of HBV biosynthesis in HepG2 and Huh7 cells is primarily controlled by different transcription factors.
Ostrich Involvement in the Selection of H5N1 Influenza Virus Possessing Mammalian-Type Amino Acids in the PB2 Protein
Authors: Shinya Kyoko , Makino Akiko , Ozawa Makoto , Kim Jin Hyun , Sakai-Tagawa Yuko , Ito Mutsumi , Le Quynh Mai , Kawaoka Yoshihiro
Published: October 2009

Amino acids at positions 627 and 701 in the PB2 protein (PB2-627 and PB2-701, respectively) of avian influenza A viruses affect virus replication in some mammalian cells. Highly pathogenic H5N1 influenza viruses possessing mammalian-type PB2-627 were detected during the Qinghai Lake outbreak in 2005 and spread to Europe and Africa. Via a database search, we found a high rate of viral isolates from
Ratitae
, including ostrich, possessing mammalian-type PB2-627 or -701. Here, we report that H5N1 avian influenza viruses possessing mammalian-type amino acids in PB2-627 or -701 are selected during replication in ostrich cells in vitro and in vivo.
Effect of Calcium-Modulating Cyclophilin Ligand on Human Immunodeficiency Virus Type 1 Particle Release and Cell Surface Expression of Tetherin
Authors: Bego Mariana G. , Dubé Mathieu , Mercier Johanne , Cohen Éric A.
Published: October 2009

The human immunodeficiency virus type 1 (HIV-1) accessory protein Vpu enhances virus particle release by counteracting a host factor that retains virions at the surfaces of infected cells. It was recently demonstrated that cellular protein BST-2/CD317/Tetherin restricts HIV-1 release in a Vpu-dependent manner. Calcium-modulating cyclophilin ligand (CAML) was also proposed to be involved in this process. We investigated whether CAML is involved in cell surface expression of Tetherin. Here, we show that CAML overexpression in permissive Cos-7 cells or CAML depletion in restrictive HeLa cells has no effect on HIV-1 release or on Tetherin surface expression, indicating that CAML is not required for Tetherin-mediated restriction of HIV-1 release.
Hepatitis C Virus Causes Uncoupling of Mitotic Checkpoint and Chromosomal Polyploidy through the Rb Pathway
Authors: Machida Keigo , Liu Jian-Chang , McNamara George , Levine Alexandra , Duan Lewei , Lai Michael M. C.
Published: October 2009

Hepatitis C virus (HCV) infection is associated with the development of hepatocellular carcinoma and probably also non-Hodgkin's B-cell lymphoma. The molecular mechanisms of HCV-associated carcinogenesis are unknown. Here we demonstrated that peripheral blood mononuclear cells obtained from hepatitis C patients and hepatocytes infected with HCV in vitro showed frequent chromosomal polyploidy. HCV infection or the expression of viral core protein alone in hepatocyte culture or transgenic mice inhibited mitotic spindle checkpoint function because of reduced Rb transcription and enhanced E2F-1 and Mad2 expression. The silencing of E2F-1 by RNA interference technology restored the function of mitotic checkpoint in core-expressing cells. Taken together, these data suggest that HCV infection may inhibit the mitotic checkpoint to induce polyploidy, which likely contributes to neoplastic transformation.
Beneficial effects of exercise: shifting the focus from body weight to other markers of health
Authors: King N A , Hopkins M , Caudwell P , Stubbs R J , Blundell J E
Published: October 2009

Background:

Exercise is widely promoted as a method of weight management, while the other health benefits are often ignored. The purpose of this study was to examine whether exercise-induced improvements in health are influenced by changes in body weight.

Methods:

Fifty-eight sedentary overweight/obese men and women (BMI 31.8 (SD 4.5) kg/m2) participated in a 12-week supervised aerobic exercise intervention (70% heart rate max, five times a week, 500 kcal per session). Body composition, anthropometric parameters, aerobic capacity, blood pressure and acute psychological response to exercise were measured at weeks 0 and 12.

Results:

The mean reduction in body weight was −3.3 (3.63) kg (p<0.01). However, 26 of the 58 participants failed to attain the predicted weight loss estimated from individuals’ exercise-induced energy expenditure. Their mean weight loss was only −0.9 (1.8) kg (p<0.01). Despite attaining a lower-than-predicted weight reduction, these individuals experienced significant increases in aerobic capacity (6.3 (6.0) ml/kg/min; p<0.01), and a decreased systolic (−6.00 (11.5) mm Hg; p<0.05) and diastolic blood pressure (−3.9 (5.8) mm Hg; p<0.01), waist circumference (−3.7 (2.7) cm; p<0.01) and resting heart rate (−4.8 (8.9) bpm, p<0.001). In addition, these individuals experienced an acute exercise-induced increase in positive mood.

Conclusions:

These data demonstrate that significant and meaningful health benefits can be achieved even in the presence of lower-than-expected exercise-induced weight loss. A less successful reduction in body weight does not undermine the beneficial effects of aerobic exercise. From a public health perspective, exercise should be encouraged and the emphasis on weight loss reduced.
ASYMPTOTICALLY IDEMPOTENT AGGREGATION OPERATORS
Authors: RICCI ROBERTO GHISELLI
Published: October 2009

This paper deals with aggregation operators. A new form of idempotency, called asymptotic idempotency, is introduced. A critical discussion of the basic notion of aggregation operator, strictly connected with asymptotic idempotency, is provided. Some general construction methods of symmetric, asymptotically idempotent aggregation operators admitting a neutral element are illustrated.
DIFFERENCE RELATION-BASED ROUGH SET AND NEGATIVE RULES IN INCOMPLETE INFORMATION SYSTEM
Authors: YANG XIBEI , YU DONGJUN , YANG JINGYU , SONG XIAONING
Published: October 2009

The purpose of this paper is to present a new rough set model for generating negative rules from the incomplete information system. A negative rule indicates that if an object does not satisfy the attribute-value pairs in the condition part, then we can exclude the decision part from such object. The proposed rough set model is constructed on the basis of a difference relation. Such difference relation is a binary relation without any constraints. Moreover, to simplify the negative rules generated from the difference relation-based rough approximations, the concepts of lower, upper approximate and rough reducts are also proposed. Some numerical examples are employed to substantiate the conceptual arguments.
LAWS OF LARGE NUMBERS FOR CONTINUOUS BELIEF MEASURES ON COMPACT SPACES
Authors: RÉBILLÉ YANN
Published: October 2009

We prove for outer continuous belief measures defined on compact spaces strong and weak laws of large numbers as Kolmogorov's one for measures. These results contribute to M. Marinacci's (Journal of Economic Theory84 (1999) 145–195) though with different methods.
Alterations in mRNA and protein levels of metalloproteinases-2, -9, and -14 and tissue inhibitor of metalloproteinase-2 responses to traumatic skeletal muscle injury
Authors: Barnes Brian R. , Szelenyi Eric R. , Warren Gordon L. , Urso Maria L.
Published: October 2009

This study characterizes the temporal relationship of membrane type-1 matrix metalloproteinase (MT1-MMP) and tissue inhibitor of metalloproteinase-2 (TIMP-2) expression in skeletal muscle following injury. Tibialis anterior (TA) muscles from 60 mice were exposed and injured by applying a cold steel probe (−79°C) to the muscle for 10 s. Thereafter, TA muscles from uninjured and injured legs were collected at 3, 10, 24, 48, and 72 h postinjury for analysis of local MT1-MMP, TIMP-2, and matrix metalloproteinases-2 and -9 (MMP-2 and MMP-9) mRNA and protein content via quantitative RT-PCR, immunoblotting, zymography, and immunofluorescence. All data are expressed as fold change of injured leg vs. uninjured leg. MT1-MMP mRNA levels were decreased significantly at 48 and 72 h postinjury by ∼9- and 21-fold, respectively ( P < 0.01). Both TIMP-2 and MMP-2 mRNA expression significantly decreased in the injured leg by ∼4- to 10-fold at 10–72 h postinjury ( P < 0.01). MMP-9 mRNA expression was significantly increased at 10, 24, and 48 h postinjury by 6- ( P < 0.05), 25-, and 12-fold ( P < 0.01), respectively. Protein content of latent (63 kDa) MT1-MMP was decreased at 48 and 72 h postinjury by ∼2-fold ( P < 0.01). Content of the soluble (50 kDa) fragment of MT1-MMP was significantly increased by ∼17-, 25-, and 67-fold at 24 ( P < 0.05), 48, and 72 h ( P < 0.01) postinjury, respectively. TIMP-2 protein levels diminished from 3 to 48 h postinjury by 1.5-fold to 1.8-fold ( P < 0.01), before returning to baseline levels at 72 h postinjury. Zymography revealed visual increases in gelatinase activity in molecular weight regions corresponding to MMP-9 and MMP-2. In conclusion, skeletal muscle injury initiates a sequence of events in the MT1-MMP proteolytic cascade resulting in elevated levels of the soluble (50 kDa) fragment of MT1-MMP, which could enhance pericellular extracellular matrix remodeling.
Neph1 regulates steady-state surface expression of Slo1 Ca2+-activated K+ channels: different effects in embryonic neurons and podocytes
Authors: Kim Eun Young , Chiu Yu-Hsin , Dryer Stuart E.
Published: October 2009

Large-conductance Ca2+-activated K+ (BKCa) channels encoded by the Slo1 gene are often components of large multiprotein complexes in excitable and nonexcitable cells. Here we show that Slo1 proteins interact with Neph1, a member of the immunoglobulin superfamily expressed in slit diaphragm domains of podocytes and in vertebrate and invertebrate nervous systems. This interaction was established by reciprocal coimmunoprecipitation of endogenous proteins from differentiated cells of a podocyte cell line, from parasympathetic neurons of the embryonic chick ciliary ganglion, and from HEK293T cells heterologously expressing both proteins. Neph1 can interact with all three extreme COOH-terminal variants of Slo1 (Slo1VEDEC, Slo1QEERL, and Slo1EMVYR) as ascertained by glutathione S-transferase (GST) pull-down assays and by coimmunoprecipitation. Neph1 is partially colocalized in intracellular compartments with endogenous Slo1 in podocytes and ciliary ganglion neurons. Coexpression in HEK293T cells of Neph1 with any of the Slo1 extreme COOH-terminal splice variants suppresses their steady-state expression on the cell surface, as assessed by cell surface biotinylation assays, confocal microscopy, and whole cell recordings. Consistent with this, small interfering RNA (siRNA) knockdown of endogenous Neph1 in embryonic day 10 ciliary ganglion neurons causes an increase in steady-state surface expression of Slo1 and an increase in whole cell Ca2+-dependent K+ current. Surprisingly, a comparable Neph1 knockdown in podocytes causes a decrease in surface expression of Slo1 and a decrease in whole cell BKCa currents. In podocytes, Neph1 siRNA also caused a decrease in nephrin, even though the Neph1 siRNA had no sequence homology with nephrin. However, we could not detect nephrin in ciliary ganglion neurons.
Endolymphatic sac is involved in the regulation of hydrostatic pressure of cochlear endolymph
Authors: Inamoto Ryuhei , Miyashita Takenori , Akiyama Kosuke , Mori Terushige , Mori Nozomu
Published: October 2009

To clarify the role of the endolymphatic sac (ES) in the regulation of endolymphatic pressure, the effects of isoproterenol, a β-adrenergic receptor agonist, and acetazolamide, a potent carbonic anhydrase inhibitor, both of which decrease ES direct current potential on cochlear hydrostatic pressure, were examined in guinea pigs. When isoproterenol was applied intravenously, hydrostatic pressures of cochlear endolymph and perilymph were significantly increased with no change in endocochlear potential or the hydrostatic pressure of cerebrospinal fluid. Acetazolamide produced no marked change in the hydrostatic pressure of cochlear endolymph. In ears with an obstructed ES, the action of isoproterenol on the hydrostatic pressure of cochlear endolymph and perilymph was suppressed. These results suggest that the ES may regulate the hydrostatic pressure of the endolymphatic system via the action of the agents such as catecholamines on the ES.
A new function for parietal epithelial cells: a second glomerular barrier
Authors: Ohse Takamoto , Chang Alice M. , Pippin Jeffrey W. , Jarad George , Hudkins Kelly L. , Alpers Charles E. , Miner Jeffrey H. , Shankland Stuart J.
Published: October 2009

The functional role of glomerular parietal epithelial cells (PECs) remains poorly understood. To test the hypothesis that PECs form an impermeable barrier to filtered protein through the formation of tight junctions (TJ), studies were performed in normal animals and in the anti-glomerular basement membrane (GBM) model of crescentic nephritis. Electron microscopy showed well-defined TJ between PECs in normal mice, which no longer could be identified when these cells became extensively damaged or detached from their underlying Bowman's basement membrane. The TJ proteins claudin-1, zonula occludens-1, and occludin stained positive in PECs; however, staining decreased in anti-GBM disease. To show that these events were associated with increased permeability across the PEC-Bowman's basement membrane barrier, control and diseased animals were injected intravenously with either Texas red-conjugated dextran (3 kDa) or ovalbumin (45 kDa) tracers. As expected, both tracers were readily filtered across the glomerular filtration barrier and taken up by proximal tubular cells. However, when the glomerular filtration barrier was injured in anti-GBM disease, tracers were taken up by podocytes and PECs. Moreover, tracers were also detected between PECs and the underlying Bowman's basement membrane, and in many instances were detected in the extraglomerular space. We propose that together with its underlying Bowman's basement membrane, the TJ of PECs serve as a second barrier to protein. When disturbed following PEC injury, the increase in permeability of this layer to filtered protein is a mechanism underlying periglomerular inflammation characteristic of anti-GBM disease.
Triceps surae contractile properties and firing rates in the soleus of young and old men
Authors: Dalton Brian H. , Harwood Brad , Davidson Andrew W. , Rice Charles L.
Published: October 2009

Mean maximal motor unit firing rates (MUFRs) of the human soleus are lower (5–20 Hz) than other limb muscles (20–50 Hz) during brief sustained contractions. With healthy adult aging, maximal MUFRs are 20–40% lower and twitch contractile speed of lower limb muscles are 10–40% slower compared with young adults. However, it is unknown whether the inherently low maximal MUFRs for the soleus are further reduced with aging in association with age-related slowing in contractile properties. The purpose of the present study was to compare the changes in triceps surae contractile properties and MUFRs of the soleus throughout a variety of contraction intensities in six old (∼75 yr old) and six young (∼24 yr old) men. Neuromuscular measures were collected from the soleus and triceps surae during repeated sessions (2–6 sessions). Populations of single MUFR trains were recorded from the soleus with tungsten microelectrodes during separate sustained 6- to 10-s isometric contractions of varying intensities [25%, 50%, 75%, and 100% maximal voluntary isometric contraction (MVC)]. The old men had weaker triceps surae strength (MVC; 35% lower) and slower contractile properties (contraction duration; 20% longer) than the young men. However, there was no difference in average MUFRs of the soleus at 75% and 100% MVC (∼14.5 Hz and ∼16.5 Hz, respectively). At 25% and 50% MVC, average rates were 10% and 20% lower in the old men compared with young, respectively. Despite a significant slowing in triceps surae contraction duration, there was no age-related change in MUFRs recorded at high contractile intensities in the soleus. Thus the relationship between the whole muscle contractile properties and MUFRs found in other muscle groups may not exist between the triceps surae and soleus and may be muscle dependent.
Effects of Sciatic Nerve Axotomy on Excitatory Synaptic Transmission in Rat Substantia Gelatinosa
Authors: Chen Yishen , Balasubramanyan Sridhar , Lai Aaron Y. , Todd Kathryn G. , Smith Peter A.
Published: October 2009

Injury or section of a peripheral nerve can promote chronic neuropathic pain. This is initiated by the appearance and persistence of ectopic spontaneous activity in primary afferent neurons that promotes a secondary, enduring increase in excitability of sensory circuits in the spinal dorsal horn (“central sensitization”). We have previously shown that 10–20 days of chronic constriction injury (CCI) of rat sciatic nerve produce a characteristic “electrophysiological signature” or pattern of changes in synaptic excitation of five different electrophysiologically defined neuronal phenotypes in the substantia gelatinosa of the dorsal horn. Although axotomy and CCI send different signals to the dorsal horn, we now find, using whole cell recording, that the “electrophysiological signature” produced 12–22 days after sciatic axotomy is quite similar to that seen with CCI. Axotomy thus has little effect on resting membrane potential, rheobase, current–voltage characteristics, or excitability of most neuron types; however, it does decrease excitatory synaptic drive to tonic firing neurons, while increasing that to delay firing neurons. Since many tonic neurons are GABAergic, whereas delay neurons do not contain γ-aminobutyric acid, axotomy may reduce synaptic excitation of inhibitory neurons while increasing that of excitatory neurons. Further analysis of spontaneous and miniature (tetrodotoxin-resistant) excitatory postsynaptic currents is consistent with the possibility that decreased excitation of tonic neurons reflects loss of presynaptic contacts. By contrast, increased excitation of “delay” neurons may reflect increased frequency of discharge of presynaptic action potentials. This would explain how synaptic excitation of tonic cells decreases despite the fact that axotomy increases spontaneous activity in primary afferent neurons.
Living in A Material World: How Visual Cues to Material Properties Affect the Way That We Lift Objects and Perceive Their Weight
Authors: Buckingham Gavin , Cant Jonathan S. , Goodale Melvyn A.
Published: October 2009

The visual properties of an object provide many cues as to the tensile strength, compliance, and density of the material from which it is made. However, it is not well understood how these implicit associations affect our perceptions of these properties and how they determine the initial forces that are applied when an object is picked up. Here we examine the effects of these cues on such forces by using the classic “material-weight illusion” (MWI). Grip and load forces were measured in three experiments as participants lifted cubes made from metal, wood, and expanded polystyrene. These cubes were adjusted to have a different mass than would be expected for a particular material. For the initial lifts, the forces were scaled to the expected weight of each object, such that the metal block was gripped and lifted with more force than the polystyrene one. After a few lifts, however, participants scaled their forces to the actual weight of the blocks, implicitly disregarding the misleading visual cues to each block's composition ( experiments 1 and 2). Despite this rapid rescaling, participants experienced a robust MWI throughout the duration of the experiments. In fact, the grip and load forces never matched the perception of weight until the differences in the visual surface properties between the blocks were removed ( experiment 3). These findings are discussed in relation to recent debates about the underlying causes of weight-based illusions and the effect of top-down visual cues on perception and action.
Differences in the Time Course of Short-Term Depression Across Receptive Fields Are Correlated With Directional Selectivity in Electrosensory Neurons
Authors: Chacron Maurice J. , Toporikova Natalia , Fortune Eric S.
Published: October 2009

Directional selectivity, in which neurons respond preferentially to one direction of movement (“preferred”) over the opposite direction (“null”), is a critical computation that is found in the nervous systems of many animals. Here we show the first experimental evidence for a correlation between differences in short-term depression and direction-selective responses to moving objects. As predicted by quantitative models, the observed differences in the time courses of short-term depression at different locations within receptive fields were correlated with measures of direction selectivity in awake, behaving weakly electric fish ( Apteronotus leptorhynchus ). Because short-term depression is ubiquitous in the central nervous systems of vertebrate animals, it may be a common mechanism used for the generation of directional selectivity and other spatiotemporal computations.
Neural Representation of Hand Kinematics During Prehension in Posterior Parietal Cortex of the Macaque Monkey
Authors: Chen Jessie , Reitzen Shari D. , Kohlenstein Jane B. , Gardner Esther P.
Published: October 2009

Studies of hand manipulation neurons in posterior parietal cortex of monkeys suggest that their spike trains represent objects by the hand postures needed for grasping or by the underlying patterns of muscle activation. To analyze the role of hand kinematics and object properties in a trained prehension task, we correlated the firing rates of neurons in anterior area 5 with hand behaviors as monkeys grasped and lifted knobs of different shapes and locations in the workspace. Trials were divided into four classes depending on the approach trajectory: forward, lateral, and local approaches, and regrasps. The task factors controlled by the animal—how and when he used the hand—appeared to play the principal roles in modulating firing rates of area 5 neurons. In all, 77% of neurons studied (58/75) showed significant effects of approach style on firing rates; 80% of the population responded at higher rates and for longer durations on forward or lateral approaches that included reaching, wrist rotation, and hand preshaping prior to contact, but only 13% distinguished the direction of reach. The higher firing rates in reach trials reflected not only the arm movements needed to direct the hand to the target before contact, but persisted through the contact, grasp, and lift stages. Moreover, the approach style exerted a stronger effect on firing rates than object features, such as shape and location, which were distinguished by half of the population. Forty-three percent of the neurons signaled both the object properties and the hand actions used to acquire them. However, the spread in firing rates evoked by each knob on reach and no-reach trials was greater than distinctions between different objects grasped with the same approach style. Our data provide clear evidence for synergies between reaching and grasping that may facilitate smooth, coordinated actions of the arm and hand.
Modular Cre/lox System and Genetic Therapeutics for Colorectal Cancer
Authors: Bordonaro Michael
Published: October 2009

The Cre/lox system is a powerful tool for targeting therapeutic effectors in a wide variety of human disorders. I review a Cre/lox Wnt‐targeted system that has shown promise against Wnt‐positive colorectal cancer cell lines. In addition to Wnt‐specific targeting of cell death inducers, the modular nature of this gene therapy model system can be exploited by designing positive and negative feedback loops to either amplify or inhibit Wnt activity for experimental or therapeutic benefit. I discuss the structural components and performance parameters of the system, the implication of these findings with respect to cancer stem cells, as well as the general applicability of this system to any disorder characterized by differential gene expression. I also consider the issue of gene delivery as well as in vivo testing requirements necessary for the further characterization and development of this system.
A New Instrument for Testing Wind Erosion by Soil Surface Shape Change
Authors: Hai Chun-xing , Liu Bao-yuan , Zhao Ye , Du Peng-fei , Yuan Xiao-yu , Jiang Hong-Tao , Zhou Rui-rong , Wang Jing
Published: October 2009

Wind erosion, a primary cause of soil degeneration, is a problem in arid and semiarid areas throughout the world. Many methods are available to study soil erosion, but there is no an effective method for making quantitative measurements in the field. To solve this problem, we have developed a new instrument that can measure the change in the shape of the soil surface, allowing quick quantification of wind erosion. In this paper, the construction and principle of the new instrument are described. Field experiments are carried out using the instrument, and the data are analyzed. The erosion depth is found to vary by 11% compared to the average for measurement areas ranging from   to  . The results show that the instrument is convenient and reliable for quantitatively measuring wind erosion in the field.
Abnormal 18F-FDG Uptake Detected with Positron Emission Tomography in a Patient with Breast Cancer: A Case of Sarcoidosis and Review of the Literature
Authors: Ataergin Selmin , Arslan Nuri , Ozet Ahmet , Ozguven Mehmet Ali
Published: October 2009

18F-FDG PET is a useful and sensitive imaging method for a variety of malignancies, however, the specificity is low in active infections and inflammatory diseases. We describe a female patient with stage IIIA breast cancer in first complete remission with combination chemotherapy who developed nodular formations in the lung and axilla 12 years later. Imaging studies as well as FDG PET showed nodular lesions and increased metabolic activity which was interpreted as the progression of the primary disease. She was first given combination chemotherapy and hormonal therapy but was proven thereafter to have sarcoidosis by pathologic examination and was successfully treated with corticosteroid treatment.
Pressure Broadening of Some He I Lines
Authors: Omar Banaz
Published: October 2009

Quantum statistical approach is adopted for calculating the spectral line
shapes of neutral helium in dense plasmas. Stark broadening of isolated He
I lines 5048 Å (), 3889 Å (), and 3188Å ()
is presented. Based on thermodynamic Green's function, the electronic contribution to the shift and width is considered. The participation of ions to the line broadening is treated in a quasistatic approximation, by taking both
quadratic Stark effect and quadrupole interaction into account. The calculated shifts and widths are compared with existing data.
Late-Onset Immune-Mediated Adverse Effects after Poly-L-Lactic Acid Injection in Non-HIV Patients: Clinical Findings and Long-Term Follow-Up
Authors: Alijotas-Reig Jaume , Garcia-Gimenez Victor , Vilardell-Tarres Miquel
Published: October 2009

Background: It has been thought that poly-L-lactic acid (PLLA) injections do not have inflammatory side effects. Recent evidence shows that local/regional/systemic delayed adverse effects may appear with its use. Objective: To evaluate the clinical complaints, treatment response and long-term follow-up of non-HIV patients with delayed immune-mediated adverse effects related to PLLA injections. Methods: Prospective, case series study of 10 patients with delayed adverse effects related to PLLA injections. The inclusion criterion was defined as the onset at least 6 months after PLLA use, with 1 or more of the following clinical signs: oedema, skin induration, swelling/tender nodules with or without discharge of pus or filler material. Several systemic manifestations were also included. Patients with immediate side effects were excluded. Patients underwent clinical management and long-term follow-up. Results: The average latency period to the onset of symptoms was 19.2 months (range: 6–60). Tender, inflammatory nodules and facial oedema were commonly seen. One case presented a systemic granulomatous disorder as a complication. After 50.2 months of average follow-up (range: 38–78), 5 patients are in remission, 4 have recurrent bouts and the last case has been lost to follow-up. Conclusion:Although infrequently, local and/or regional and/or systemic delayed and recurrent granulomatous reactions may complicate PLLA gel injections.
Clinical Aspects of Diffuse Cutaneous Mastocytosis in Children: Two Variants
Authors: Heide Rogier , Zuidema Esther , Beishuizen Auke , Den Hollander Jan C. , Van Gysel Dirk , Seyger Marieke M.B. , Pasmans Suzanne G.M.A. , Kakourou Talia , Oranje Arnold P.
Published: October 2009

Objective: This paper describes two different clinical presentations of diffuse cutaneous mastocytosis (DCM), based on the largest series published to date. As far as we are aware, these two variants of clinical presentations have not yet been reported. Design: We undertook a case controlled analysis of 8 children with DCM. Results of laboratory testing including mast cell mediator levels, and clinical symptoms on presentation and during follow-up were analyzed. Results: The levels of relevant mast cell mediators were initially high in all cases but declined sharply later on. There was a reduction of 20% in 2 of the 7 cases, whereas there was a reduction of 80% in the remaining 5. No reduction occurred in 1 case. Clinical improvement followed the same pattern. Conclusions: DCM is a rare variant of cutaneous childhood onset mastocytosis. Various forms show the same or overlapping features at various times. It appears to follow a course similar to that in other types of childhood onset mastocytosis, taking into account the decreased symptoms and the levels of mast cell mediators during follow-up. Obtaining a bone marrow biopsy should be considered only in those cases where there is no improvement or even worsening of signs or symptoms and persistent elevated levels of mast cell mediators.
Rates of venous thromboembolism occurrence in medical patients among the insured population
Authors: Hussein Mohamed , Lin Jay , Battleman David , Spyropoulos Alex
Published: October 2009

The burden of venous thromboembolism (VTE) remains high in the United States (US). This study assesses the rate of VTE prophylaxis in a large real-world population of medically ill patients and identifies factors which confer VTE risk to this population. Discharges from the PharMetrics database were included if they were aged ≥40 years and had a hospitalisation claim (Jan 2001-Dec 2005) for cancer, congestive heart failure (CHF), severe infectious disease (SID), or lung disease. Discharges with incomplete records in the prior year to the index hospitalisation claim date were excluded. VTE rate, type (deep venous thrombosis [DVT] or pulmonary embolism [PE]), and time to VTE were compared between groups. Multivariate logistic regression analysis was used to identify independent predictors of VTE occurrence. A total of 158,325 patients were included in the study. Cancer patients had the highest incidence of VTE (7.6%), with the average for all patients being 5.6% (1.5% PE).VTE occurred most frequently post discharge, with the median time being 74 days. Post-discharge prophylaxis was provided to 13.1% of CHF patients and < 5% of all other patients. Independent predictors of VTE included a pre-index VTE (odds ratio [OR] 9.06, 95% confidence interval [CI] 8.28–9.91) and a primary diagnosis of cancer compared with a diagnosis of SID (OR 1.34, 95% CI 1.24–1.46). In conclusion, commercially insured medical patients in the US are at high risk of VTE following hospital discharge. One-quarter of medical patients who developed a VTE are at high risk of developing the more severe form of the disease, namely PE, with independent predictors of VTE in the postdischarge period including previous VTE and cancer.