bluuebunny/crossref_metadata_2025 huggingface dataset:
Relapse of Serratia marcescens Sternal Osteitis 15 Years after the First Episode
Authors: Paquin Axelle , Lepelletier Didier , Leprince Céline , Chamoux Catherine , Treilhaud Michèle , Despins Philippe , Reynaud Alain , Corvec Stéphane
Published: November 2011

Sternal osteitis, a potential consequence of cardiac surgery, remains rare. The bacteria involved belong mostly to the genus
Staphylococcus
. Sternal infections caused by
Serratia marcescens
are exceptional. We report an unusual recurrence of sternal infection with
S. marcescens
, 15 years after the initial episode. The identities of the isolates were determined by genomic analysis.
Comparison of the Hybrid Capture 2 and cobas 4800 Tests for Detection of High-Risk Human Papillomavirus in Specimens Collected in PreservCyt Medium
Authors: Wong Anita A. , Fuller Jeff , Pabbaraju Kanti , Wong Sallene , Zahariadis George
Published: November 2011

Clinical cervical cytology specimens (
n
= 466) collected in PreservCyt (Hologic Inc.) were used to evaluate the agreement between Hybrid Capture 2 (hc2; Qiagen) and cobas 4800 (c4800; Roche Molecular Diagnostics) for the detection of high-risk human papillomavirus (HR HPV) genotype infections. The agreement between the two assays was 93.8% (kappa = 0.87; 95% confidence interval, 0.828 to 0.918), with 186 and 251 concordant positive and negative results, respectively. All 186 concordant positives were confirmed using the Linear Array (LA; Roche Molecular Diagnostics) genotyping test. Of the 29 samples with discordant results (6.2%), 18 were hc2 positive and LA verified 17 as positive for HR HPV. Eleven discordant specimens were c4800 positive, and LA confirmed 5 as positive for HR HPV. As of October 2009, practice guidelines in Alberta, Canada, recommend reflex HPV testing for women over 30 years old with atypical squamous cells of undetermined significance (ASCUS) and for women over 50 years old with low-grade squamous intraepithelial lesions (LSIL) to help prioritize those who should undergo further evaluation. In this study, agreement between hc2 and c4800 results for samples from women over 30 years old with ASCUS cytology was 92.3% (
n
= 13), while no samples from women over 50 years old with LSIL cytology were identified for analysis.
Direct MALDI-TOF Mass Spectrometry Assay of Blood Culture Broths for Rapid Identification of Candida Species Causing Bloodstream Infections: an Observational Study in Two Large Microbiology Laboratories
Authors: Spanu Teresa , Posteraro Brunella , Fiori Barbara , D'Inzeo Tiziana , Campoli Serena , Ruggeri Alberto , Tumbarello Mario , Canu Giulia , Trecarichi Enrico Maria , Parisi Gabriella , Tronci Mirella , Sanguinetti Maurizio , Fadda Giovanni
Published: November 2011

We evaluated the reliability of the Bruker Daltonik's MALDI Biotyper system in species-level identification of yeasts directly from blood culture bottles. Identification results were concordant with those of the conventional culture-based method for 95.9% of
Candida albicans
(187/195) and 86.5% of non-
albicans Candida
species (128/148). Results were available in 30 min (median), suggesting that this approach is a reliable, time-saving tool for routine identification of
Candida
species causing bloodstream infection.
Cooperation between Viral Interferon Regulatory Factor 4 and RTA To Activate a Subset of Kaposi's Sarcoma-Associated Herpesvirus Lytic Promoters
Authors: Xi Xiangmei , Persson Linda M. , O'Brien Michael W. , Mohr Ian , Wilson Angus C.
Published: November 2011

The four Kaposi's sarcoma-associated herpesvirus (KSHV)-encoded interferon (IFN) regulatory factor homologues (vIRF1 to vIRF4) are used to counter innate immune defenses and suppress p53. The vIRF genes are arranged in tandem but differ in function and expression. In KSHV-infected effusion lymphoma lines, K10.5/vIRF3 and K11/vIRF2 mRNAs are readily detected during latency, whereas K9/vIRF1 and K10/vIRF4 mRNAs are upregulated during reactivation. Here we show that the K10/vIRF4 promoter responds to the lytic switch protein RTA in KSHV-infected cells but is essentially unresponsive in uninfected cells. Coexpression of RTA with vIRF4 is sufficient to restore regulation, a property not shared by other vIRFs. The K9/vIRF1 promoter behaves similarly, and production of infectious virus is enhanced by the presence of vIRF4. Synergy requires the DNA-binding domain (DBD) and C-terminal IRF homology regions of vIRF4. Mutations of arginine residues within the putative DNA recognition helix of vIRF4 or the invariant cysteines of the adjacent CxxC motif abolish cooperation with RTA, in the latter case by preventing self-association. The oligomerization and transactivation functions of RTA are also essential for synergy. The K10/vIRF4 promoter contains two transcription start sites (TSSs), and a 105-bp fragment containing the proximal promoter is responsive to vIRF4/RTA. Binding of a cellular factor(s) to this fragment is altered when both viral proteins are present, suggesting a possible mechanism for transcriptional synergy. Reliance on coregulators encoded by either the host or viral genome provides an elegant strategy for expanding the regulatory potential of a master regulator, such as RTA.
Distinct Domains in ORF52 Tegument Protein Mediate Essential Functions in Murine Gammaherpesvirus 68 Virion Tegumentation and Secondary Envelopment
Authors: Wang Lili , Guo Haitao , Reyes Nichole , Lee Shaoying , Bortz Eric , Guo Fengli , Sun Ren , Tong Liang , Deng Hongyu
Published: November 2011

Epstein-Barr virus and Kaposi's sarcoma-associated herpesvirus are etiologically associated with several types of human malignancies. However, as these two human gammaherpesviruses do not replicate efficiently in cultured cells, the morphogenesis of gammaherpesvirus virions is poorly understood. Murine gammaherpesvirus 68 (MHV-68) provides a tractable model to define common, conserved features of gammaherpesvirus biology. ORF52 of MHV-68 is conserved among gammaherpesviruses. We have previously shown that this tegument protein is essential for the envelopment and egress of viral particles and solved the crystal structure of ORF52 dimers. To more closely examine its role in virion maturation, we performed immunoelectron microscopy of MHV-68-infected cells and found that ORF52 localized to both mature, extracellular virions and immature viral particles in the cytoplasm. ORF52 consists of three α-helices followed by one β-strand. To understand the structural requirements for ORF52 function, we constructed mutants of ORF52 and examined their ability to complement an ORF52-null MHV-68 virus. Mutations in conserved residues in the N-terminal α1-helix and C terminus, or deletion of the α2-helix, resulted in a loss-of-function phenotype. Furthermore, the α1-helix was crucial for the predominantly punctate cytoplasmic localization of ORF52, while the α2-helix was a key domain for ORF52 dimerization. Immunoprecipitation experiments demonstrated that ORF52 interacts with another MHV-68 tegument protein, ORF42; however, a single point mutation in R95 in the C terminus of ORF52 led to the loss of this interaction. Moreover, the homologues of MHV-68 ORF52 in Kaposi's sarcoma-associated herpesvirus and Epstein-Barr virus complement the defect in ORF52-null MHV-68 and interact with MHV-68 ORF52. Taken together, these data uncover the relationship between the α-helical structure and the molecular basis for ORF52 function. This is the first structure-based functional domain mapping study for an essential gammaherpesvirus tegument protein.
High-Resolution Analysis of Intrahost Genetic Diversity in Dengue Virus Serotype 1 Infection Identifies Mixed Infections
Authors: Thai Khoa T. D. , Henn Matthew R. , Zody Michael C. , Tricou Vianney , Nguyet Nguyen Minh , Charlebois Patrick , Lennon Niall J. , Green Lisa , de Vries Peter J. , Hien Tran Tinh , Farrar Jeremy , van Doorn H. Rogier , de Jong Menno D. , Birren Bruce W. , Holmes Edward C. , Simmons Cameron P.
Published: November 2011

Little is known about the rate at which genetic variation is generated within intrahost populations of dengue virus (DENV) and what implications this diversity has for dengue pathogenesis, disease severity, and host immunity. Previous studies of intrahost DENV variation have used a low frequency of sampling and/or experimental methods that do not fully account for errors generated through amplification and sequencing of viral RNAs. We investigated the extent and pattern of genetic diversity in sequence data in domain III (DIII) of the envelope (E) gene in serial plasma samples (
n
= 49) taken from 17 patients infected with DENV type 1 (DENV-1), totaling some 8,458 clones. Statistically rigorous approaches were employed to account for artifactual variants resulting from amplification and sequencing, which we suggest have played a major role in previous studies of intrahost genetic variation. Accordingly, nucleotide sequence diversities of viral populations were very low, with conservative estimates of the average levels of genetic diversity ranging from 0 to 0.0013. Despite such sequence conservation, we observed clear evidence for mixed infection, with the presence of multiple phylogenetically distinct lineages present within the same host, while the presence of stop codon mutations in some samples suggests the action of complementation. In contrast to some previous studies we observed no relationship between the extent and pattern of DENV-1 genetic diversity and disease severity, immune status, or level of viremia.
Monoclonal Antibody-Based Antigenic Mapping of Norovirus GII.4-2002
Authors: Lindesmith Lisa C. , Debbink Kari , Swanstrom Jesica , Vinjé Jan , Costantini Verónica , Baric Ralph S. , Donaldson Eric F.
Published: November 2011

Noroviruses are the primary cause of epidemic gastroenteritis in humans, and GII.4 strains cause ∼80% of the overall disease burden. Surrogate neutralization assays using sera and mouse monoclonal antibodies (MAbs) suggest that antigenic variation maintains GII.4 persistence in the face of herd immunity, as the emergence of new pandemic strains is accompanied by newly evolved neutralization epitopes. To potentially identify specific blockade epitopes that are likely neutralizing and evolving between pandemic strains, mice were hyperimmunized with GII.4-2002 virus-like particles (VLPs) and the resulting MAbs were characterized by biochemical and immunologic assays. All of the MAbs but one recognized GII.4 VLPs representing strains circulating from 1987 to 2009. One MAb weakly recognized GII.4-1987 and -1997 while strongly interacting with 2002 VLPs. This antibody was highly selective and effective at blocking only GII.4-2002-ligand binding. Using bioinformatic analyses, we predicted an evolving GII.4 surface epitope composed of amino acids 407, 412, and 413 and subsequently built mutant VLPs to test the impact of the epitope on MAb binding and blockade potential. Replacement of the 2002 epitope with the epitopes found in 1987 or 2006 strains either reduced or ablated enzyme immunoassay recognition by the GII.4-2002-specific blockade MAb. These data identify a novel, evolving blockade epitope that may be associated with protective immunity, providing further support for the hypotheses that GII.4 norovirus evolution results in antigenic variation that allows the virus to escape from protective herd immunity, resulting in new epidemic strains.
Reassortment and Mutation of the Avian Influenza Virus Polymerase PA Subunit Overcome Species Barriers
Authors: Mehle Andrew , Dugan Vivien G. , Taubenberger Jeffery K. , Doudna Jennifer A.
Published: November 2011

The emergence of new pandemic influenza A viruses requires overcoming barriers to cross-species transmission as viruses move from animal reservoirs into humans. This complicated process is driven by both individual gene mutations and genome reassortments. The viral polymerase complex, composed of the proteins PB1, PB2, and PA, is a major factor controlling host adaptation, and reassortment events involving polymerase gene segments occurred with past pandemic viruses. Here we investigate the ability of polymerase reassortment to restore the activity of an avian influenza virus polymerase that is normally impaired in human cells. Our data show that the substitution of human-origin PA subunits into an avian influenza virus polymerase alleviates restriction in human cells and increases polymerase activity
in vitro
. Reassortants with 2009 pandemic H1N1 PA proteins were the most active. Mutational analyses demonstrated that the majority of the enhancing activity in human PA results from a threonine-to-serine change at residue 552. Reassortant viruses with avian polymerases and human PA subunits, or simply the T552S mutation, displayed faster replication kinetics in culture and increased pathogenicity in mice compared to those containing a wholly avian polymerase complex. Thus, the acquisition of a human PA subunit, or the signature T552S mutation, is a potential mechanism to overcome the species-specific restriction of avian polymerases and increase virus replication. Our data suggest that the human, avian, swine, and 2009 H1N1-like viruses that are currently cocirculating in pig populations set the stage for PA reassortments with the potential to generate novel viruses that could possess expanded tropism and enhanced pathogenicity.
Mucosal and Peripheral Lin
−
HLA-DR
+
CD11c/123
−
CD13
+
CD14
−
Mononuclear Cells Are Preferentially Infected during Acute Simian Immunodeficiency Virus Infection
Authors: Moore Andrew C. , Bixler Sandra L. , Lewis Mark G. , Verthelyi Daniela , Mattapallil Joseph J.
Published: November 2011

Massive infection of memory CD4 T cells is a hallmark of early simian immunodeficiency virus (SIV) infection, with viral infection peaking at day 10 postinfection (p.i.), when a majority of memory CD4 T cells in mucosal and peripheral tissues are infected. It is not clear if mononuclear cells from the monocyte and macrophage lineages are similarly infected during this early phase of explosive HIV and SIV infections. Here we show that, at day 10 p.i., Lin
−
HLA-DR
+
CD11c/123
−
CD13
+
CD14
−
macrophages in the jejunal mucosa were infected, albeit at lower levels than CD4 memory T cells. Interestingly, Lin
−
HLA-DR
+
CD11c/123
−
CD13
+
CD14
−
macrophages in peripheral blood, like their mucosal counterparts, were preferentially infected compared to Lin
−
HLA-DR
+
CD11c/123
−
CD13
+
CD14
+
monocytes, suggesting that differentiated macrophages were selectively infected by SIV. CD13
+
CD14
−
macrophages expressed low levels of CD4 compared to CD4 T cells but expressed similar levels of CCR5 as lymphocytes. Interestingly, CD13
+
CD14
−
macrophages expressed Apobec3G at lower levels than CD13
+
CD14
+
monocytes, suggesting that intracellular restriction may contribute to the differential infection of mononuclear subsets. Taken together, our results suggest that CD13
+
CD14
−
macrophages in mucosal and peripheral tissues are preferentially infected very early during the course of SIV infection.
HIV-1 Clinical Isolates Resistant to CCR5 Antagonists Exhibit Delayed Entry Kinetics That Are Corrected in the Presence of Drug
Authors: Putcharoen Opass , Lee Sun Hee , Henrich Timothy J. , Hu Zixin , Vanichanan Jakapat , Coakley Eoin , Greaves Wayne , Gulick Roy M. , Kuritzkes Daniel R. , Tsibris Athe M. N.
Published: November 2011

HIV CCR5 antagonists select for
env
gene mutations that enable virus entry via drug-bound coreceptor. To investigate the mechanisms responsible for viral adaptation to drug-bound coreceptor-mediated entry, we studied viral isolates from three participants who developed CCR5 antagonist resistance during treatment with vicriviroc (VCV), an investigational small-molecule CCR5 antagonist. VCV-sensitive and -resistant viruses were isolated from one HIV subtype C- and two subtype B-infected participants; VCV-resistant isolates had mutations in the V3 loop of gp120 and were cross-resistant to TAK-779, an investigational antagonist, and maraviroc (MVC). All three resistant isolates contained a 306P mutation but had variable mutations elsewhere in the V3 stem. We used a virus-cell β-lactamase (BlaM) fusion assay to determine the entry kinetics of recombinant viruses that incorporated full-length VCV-sensitive and -resistant envelopes. VCV-resistant isolates exhibited delayed entry rates in the absence of drug, relative to pretherapy VCV-sensitive isolates. The addition of drug corrected these delays. These findings were generalizable across target cell types with a range of CD4 and CCR5 surface densities and were observed when either population-derived or clonal envelopes were used to construct recombinant viruses. V3 loop mutations alone were sufficient to restore virus entry in the presence of drug, and the accumulation of V3 mutations during VCV therapy led to progressively higher rates of viral entry. We propose that the restoration of pre-CCR5 antagonist therapy HIV entry kinetics drives the selection of V3 loop mutations and may represent a common mechanism that underlies the emergence of CCR5 antagonist resistance.
Identification of New Viral Genes and Transcript Isoforms during Epstein-Barr Virus Reactivation using RNA-Seq
Authors: Concha Monica , Wang Xia , Cao Subing , Baddoo Melody , Fewell Claire , Lin Zhen , Hulme William , Hedges Dale , McBride Jane , Flemington Erik K.
Published: November 2011

Using an enhanced RNA-Seq pipeline to analyze Epstein-Barr virus (EBV) transcriptomes, we investigated viral and cellular gene expression in the Akata cell line following B-cell-receptor-mediated reactivation. Robust induction of EBV gene expression was observed, with most viral genes induced >200-fold and with EBV transcripts accounting for 7% of all mapped reads within the cell. After induction, hundreds of candidate splicing events were detected using the junction mapper TopHat, including a novel nonproductive splicing event at the gp350/gp220 locus and several alternative splicing events at the LMP2 locus. A more detailed analysis of lytic LMP2 transcripts showed an overall lack of the prototypical type III latency splicing events. Analysis of nuclear versus cytoplasmic RNA-Seq data showed that the lytic forms of LMP2, EBNA-2, EBNA-LP, and EBNA-3A, -3B, and -3C have higher nuclear-to-cytoplasmic accumulation ratios than most lytic genes, including classic late genes. These data raise the possibility that at least some lytic transcripts derived from these latency gene loci may have unique, noncoding nuclear functions during reactivation. Our analysis also identified two previously unknown genes, BCLT1 and BCRT2, that map to the BamHI C-region of the EBV genome. Pathway analysis of cellular gene expression changes following B-cell receptor activation identified an inflammatory response as the top predicted function and ILK and TREM1 as the top predicted canonical pathways.
Oxidative stress-induced modifications of histidyl-tRNA synthetase affect its tRNA aminoacylation activity but not its immunoreactivity
Authors: van Dooren Sander H.J. , Raijmakers Reinout , Pluk Helma , Lokate Angelique M.C. , Koemans Tom S. , Spanjers Richelle E.C. , Heck Albert J.R. , Boelens Wilbert C. , van Venrooij Walther J. , Pruijn Ger J.M.
Published: November 2011

The aminoacyl-tRNA synthetases are ubiquitously expressed enzymes that catalyze the esterification of amino acids to their cognate tRNAs. Autoantibodies against several aminoacyl-tRNA synthetases are found in autoimmune polymyositis and dermatomyositis patients. Because necrosis is often found in skeletal muscle biopsies of these patients, we hypothesized that cell-death-induced protein modifications may help in breaking immunological tolerance. Since cell death is associated with oxidative stress, the effect of oxidative stress on the main myositis-specific autoantibody target Jo-1 (histidyl-tRNA synthetase; HisRS) was studied in detail. The exposure of Jurkat cells to hydrogen peroxide resulted in the detection of several oxidized methionines and one oxidized tryptophan residue in the HisRS protein, as demonstrated by mass spectrometry. Unexpectedly, the tRNA aminoacylation activity of HisRS appeared to be increased upon oxidative modification. The analysis of myositis patient sera did not lead to the detection of autoantibodies that are specifically reactive with the modified HisRS protein. The results of this study demonstrate that the Jo-1/HisRS autoantigen is modified under oxidative stress conditions. The consequences of these modifications for the function of HisRS and its autoantigenicity are discussed.
CALCULATION OF PHONON DISPERSION FOR TRANSITION METALS V, Nb AND Ta
Authors: XIE YOU , ZHANG JIAN-MIN
Published: November 2011

Combining the modified analytic embedded atom method (MAEAM) with lattice dynamics theory, the phonon dispersion along five symmetry directions have been calculated for three transition metals V, Nb and Ta . A good agreement between calculations and experiments along three high symmetry directions [q00], [qqq] and [qq0] implies that the predicted phonon dispersion along the other two directions [1qq] and [Formula: see text] are well behaved. Along each direction, the phonon frequency decreases for V, Nb and Ta successively may be related to the ratio of the cohesive energy to atomic mass.
Mica-controlled anisotropy within mid-to-upper crustal mylonites: an EBSD study of mica fabrics in the Alpine Fault Zone, New Zealand
Authors: Dempsey Edward D. , Prior Dave J. , Mariani Elisabetta , Toy Virginia G. , Tatham Daniel J.
Published: November 2011

The lattice preferred orientation (LPO) of both muscovite and biotite were measured by electron backscatter diffraction (EBSD) and these data, together with the LPOs of the other main constituent minerals, were used to produce models of the seismic velocity anisotropy of the Alpine Fault Zone. Numerical experiments examine the effects of varying modal percentages of mica within the fault rocks. These models suggest that when the mica modal proportions approach 20% in quartzofeldspathic mylonites the intrinsic seismic anisotropy of the studied fault zone is dominated by mica, with the direction of the fastest P and S wave velocities strongly dependent on the mica LPOs. The LPOs show that micas produce three distinct patterns within mylonitic fault zones: C-fabric, S-fabric and a composite S–C fabric. The asymmetry of the LPOs can be used as kinematic indicators for the deformation within mylonites. Kinematic data from the micas matches the kinematic interpretation of quartz LPOs and field data. The modelling of velocities and velocity anisotropies from sample LPOs is consistent with geophysical data from the crust under the Southern Alps. The Alpine Fault mylonites and parallel Alpine schists have intrinsic P-wave velocity anisotropies of 12% and S-wave anisotropies of 10%.
Users' (Dis)satisfaction with the personalTV application
Authors: De Moor Katrien , De Pessemier Toon , Mechant Peter , Courtois Cédric , Verdejo Adrian Juan , De Marez Lieven , Martens Luc
Published: November 2011

The overabundance of content on online video platforms has made intelligent recommender systems that assist users in finding content matching their personal preferences indispensable. This article reports on a study in which “PersonalTV,” an online video recommendation application that has been developed for research purposes, was evaluated by a panel of test users for the first time. In view of this, objective implicit and subjective explicit user feedback were triangulated. The “PersonalTV” application enables its users to explore and watch videos from the YouTube library. It builds up a personal viewing profile in order to give personalized content suggestions. We investigated the relation between the recommended content and the consumption percentage (RQ 1), between the recommended content and the reported satisfaction (RQ 2), and explored whether these objective and subjective measures converge (RQ 3). Additional user feedback that may help to improve the application was collected.
Write-N-Speak
Authors: Piper Anne Marie , Weibel Nadir , Hollan James D.
Published: November 2011

Aphasia is characterized by a reduced ability to understand and/or generate speech and language. Speech-language therapy helps individuals with aphasia regain language and cope with changes in their communication abilities. The therapy process is largely paper-based, making multimodal digital pen technology a promising tool for supporting therapy activities. We report on ten months of field research where we examine the practice of speech-language therapy, implement Write-N-Speak, a digital-paper toolkit for end-user creation of custom therapy materials, and deploy this system for 12 weeks with one therapist-client dyad in a clinical setting. The therapist used Write-N-Speak to create a range of materials including custom interactive worksheets, photographs programmed with the client’s voice, and interactive stickers on household items to aid object recognition and naming. We conclude with a discussion of multimodal digital pen technology for this and other therapy activities.
Stroke Therapy through Motion-Based Games
Authors: Alankus Gazihan , Proffitt Rachel , Kelleher Caitlin , Engsberg Jack
Published: November 2011

In the United States alone, more than five million people are living with long term motor impairments caused by a stroke. Recently, video games with affordable motion-based input devices have been proposed as a part of therapy to help people recover lost range of motion and motor control. While researchers have demonstrated the potential utility of therapeutic games through controlled studies, relatively little work has explored their long-term home-based use. We conducted a six-week home study with a 62-year-old woman who was seventeen years post-stroke. She played therapeutic games for approximately one hour a day, five days a week. Over the six weeks, she recovered significant motor abilities, which is unexpected given the time since her stroke. We explore detecting such improvements early, using game logs for daily measurements of motor ability to complement the standard measurements that are taken less often. Through observations and interviews, we present lessons learned about the barriers and opportunities that arise from long-term home-based use of therapeutic games.
Data-Driven Synthesis of Spatially Inflected Verbs for American Sign Language Animation
Authors: Lu Pengfei , Huenerfauth Matt
Published: November 2011

We are studying techniques for producing realistic and understandable animations of American Sign Language (ASL); such animations have accessibility benefits for signers with lower levels of written language literacy. This article describes and evaluates a novel method for modeling and synthesizing ASL animations based on samples of ASL signs collected from native signers. We apply this technique to ASL inflecting verbs, common signs in which the location and orientation of the hands is influenced by the arrangement of locations in 3D space that represent entities under discussion. We train mathematical models of hand movement on animation data of signs produced by a native signer. In evaluation studies with native ASL signers, the verb animations synthesized from our model had similar subjective-rating and comprehension-question scores to animations produced by a human animator; they also achieved higher scores than baseline animations. Further, we examine a split modeling technique for accommodating certain verb signs with complex movement patterns, and we conduct an analysis of how robust our modeling techniques are to reductions in the size of their training data. The modeling techniques in this article are applicable to other types of ASL signs and to other sign languages used internationally. Our models’ parameterization of sign animations can increase the repertoire of generation systems and can partially automate the work of humans using sign language scripting systems.
A non-cross-bridge, static tension is present in permeabilized skeletal muscle fibers after active force inhibition or actin extraction
Authors: Cornachione Anabelle S. , Rassier Dilson E.
Published: November 2011

When activated muscle fibers are stretched, there is a long-lasting increase in the force. This phenomenon, referred to as “residual force enhancement,” has characteristics similar to those of the “static tension,” a long-lasting increase in force observed when muscles are stretched in the presence of Ca2+ but in the absence of myosin-actin interaction. Independent studies have suggested that these two phenomena have a common mechanism and are caused either by 1) a Ca2+-induced stiffening of titin or by 2) promoting titin binding to actin. In this study, we performed two sets of experiments in which activated fibers (pCa2+ 4.5) treated with the myosin inhibitor blebbistatin were stretched from 2.7 to 2.8 μm at a speed of 40 Lo/s, first, after partial extraction of TnC, which inhibits myosin-actin interactions, or, second, after treatment with gelsolin, which leads to the depletion of thin (actin) filaments. We observed that the static tension, directly related with the residual force enhancement, was not changed after treatments that inhibit myosin-actin interactions or that deplete fibers from troponin C and actin filaments. The results suggest that the residual force enhancement is caused by a stiffening of titin upon muscle activation but not with titin binding to actin. This finding indicates the existence of a Ca2+-regulated, titin-based stiffness in skeletal muscles.
Age-related changes in afferent responses in sensory neurons to mechanical stimulation of osteoblasts in coculture system
Authors: Asada Keiji , Obata Koji , Horiguchi Kazuhide , Takaki Miyako
Published: November 2011

Bone homeostasis is regulated by mechanical stimulation (MS). The sensory mechanism of bone tissue for MS remains unknown in the maintenance of bone homeostasis. We aimed to investigate the sensory mechanism from osteoblasts to sensory neurons in a coculture system by MS of osteoblasts. Primary sensory neurons isolated from dorsal root ganglia (DRG) of neonatal, juvenile, and adult mice and osteoblasts isolated from calvaria of neonatal mice were cocultured for 24 h. The responses in DRG neurons elicited by MS of osteoblasts with a glass micropipette were detected by increases in intracellular Ca2+ concentration ([Ca2+]i) with fluo 3-AM. In all developmental stages mice, [Ca2+]i-increasing responses in osteoblasts were promptly elicited by MS. After a short delay, [Ca2+]i-increasing responses were observed in neurites of DRG neurons. The osteoblastic response to second MS was largely attenuated by a stretch-activated Ca2+ channel blocker, gadolinium. The increases of [Ca2+]i in DRG neurons were abolished by a P2 receptor antagonist; suramin, a P2X receptor antagonist, pyridoxal-phosphate-6-azophenyl-2′,4′-disulfonate; and an ATP-hydrolyzing enzyme, apyrase. Satellite cells were found around DRG neurons in cocultured cells of only neonatal and juvenile mice. After satellite cells were removed, excessive abnormal responses to MS of osteoblasts were observed in neonatal neurites with unchanged osteoblast responses. The present study indicated that MS of bone tissue elicited afferent P2X receptor-mediated purinergic transmission to sensory neurons in all stages mice. This transmission is modulated by satellite cells, which may have protective actions on sensory neurons.
Neuromodulation targets intrinsic cardiac neurons to attenuate neuronally mediated atrial arrhythmias
Authors: Gibbons David D. , Southerland E. Marie , Hoover Donald B. , Beaumont Eric , Armour J. Andrew , Ardell Jeffrey L.
Published: November 2011

Our objective was to determine whether atrial fibrillation (AF) results from excessive activation of intrinsic cardiac neurons (ICNs) and, if so, whether select subpopulations of neurons therein represent therapeutic targets for suppression of this arrhythmogenic potential. Trains of five electrical stimuli (0.3–1.2 mA, 1 ms) were delivered during the atrial refractory period to mediastinal nerves (MSN) on the superior vena cava to evoke AF. Neuroanatomical studies were performed by injecting the neuronal tracer DiI into MSN sites that induced AF. Functional studies involved recording of neuronal activity in situ from the right atrial ganglionated plexus (RAGP) in response to MSN stimulation (MSNS) prior to and following neuromodulation involving either preemptive spinal cord stimulation (SCS; T1–T3, 50 Hz, 200-ms duration) or ganglionic blockade (hexamethonium, 5 mg/kg). The tetramethylindocarbocyanine perchlorate (DiI) neuronal tracer labeled a subset (13.2%) of RAGP neurons, which also colocalized with cholinergic or adrenergic markers. A subset of DiI-labeled RAGP neurons were noncholinergic/nonadrenergic. MSNS evoked an ∼4-fold increase in RAGP neuronal activity from baseline, which SCS reduced by 43%. Hexamethonium blocked MSNS-evoked increases in neuronal activity. MSNS evoked AF in 78% of right-sided MSN sites, which SCS reduced to 33% and hexamethonium reduced to 7%. MSNS-induced bradycardia was maintained with SCS but was mitigated by hexamethonium. We conclude that MSNS activates subpopulations of intrinsic cardiac neurons, thereby resulting in the formation of atrial arrhythmias leading to atrial fibrillation. Stabilization of ICN local circuit neurons by SCS or the local circuit and autonomic efferent neurons with hexamethonium reduces the arrhythmogenic potential.
A novel coding mechanism for social vocalizations in the lateral amygdala
Authors: Gadziola Marie A. , Grimsley Jasmine M. S. , Shanbhag Sharad J. , Wenstrup Jeffrey J.
Published: November 2011

The amygdala plays a central role in evaluating the significance of acoustic signals and coordinating the appropriate behavioral responses. To understand how amygdalar responses modulate auditory processing and drive emotional expression, we assessed how neurons respond to and encode information that is carried within complex acoustic stimuli. We characterized responses of single neurons in the lateral nucleus of the amygdala to social vocalizations and synthetic acoustic stimuli in awake big brown bats. Neurons typically responded to most of the social vocalizations presented (mean = nine of 11 vocalizations) but differentially modulated both firing rate and response duration. Surprisingly, response duration provided substantially more information about vocalizations than did spike rate. In most neurons, variation in response duration depended, in part, on persistent excitatory discharge that extended beyond stimulus duration. Information in persistent firing duration was significantly greater than in spike rate, and the majority of neurons displayed more information in persistent firing, which was more likely to be observed in response to aggressive vocalizations (64%) than appeasement vocalizations (25%), suggesting that persistent firing may relate to the behavioral context of vocalizations. These findings suggest that the amygdala uses a novel coding strategy for discriminating among vocalizations and underscore the importance of persistent firing in the general functioning of the amygdala.
Age-dependent effect of hearing loss on cortical inhibitory synapse function
Authors: Takesian Anne E. , Kotak Vibhakar C. , Sanes Dan H.
Published: November 2011

The developmental plasticity of excitatory synapses is well established, particularly as a function of age. If similar principles apply to inhibitory synapses, then we would expect manipulations during juvenile development to produce a greater effect and experience-dependent changes to persist into adulthood. In this study, we first characterized the maturation of cortical inhibitory synapse function from just before the onset of hearing through adulthood. We then examined the long-term effects of developmental conductive hearing loss (CHL). Whole cell recordings from gerbil thalamocortical brain slices revealed a significant decrease in the decay time of inhibitory currents during the first 3 mo of normal development. When assessed in adults, developmental CHL led to an enduring decrease of inhibitory synaptic strength, whereas the maturation of synaptic decay time was only delayed. Early CHL also depressed the maximum discharge rate of fast-spiking, but not low-threshold-spiking, inhibitory interneurons. We then asked whether adult onset CHL had a similar effect, but neither inhibitory current amplitude nor decay time was altered. Thus inhibitory synapse function displays a protracted development during which deficits can be induced by juvenile, but not adult, hearing loss. These long-lasting changes to inhibitory function may contribute to the auditory processing deficits associated with early hearing loss.
Extracellular pH dynamics of retinal horizontal cells examined using electrochemical and fluorometric methods
Authors: Jacoby Jason , Kreitzer Matthew A. , Alford Simon , Qian Haohua , Tchernookova Boriana K. , Naylor Ethan R. , Malchow Robert Paul
Published: November 2011

Extracellular H+has been hypothesized to mediate feedback inhibition from horizontal cells onto vertebrate photoreceptors. According to this hypothesis, depolarization of horizontal cells should induce extracellular acidification adjacent to the cell membrane. Experiments testing this hypothesis have produced conflicting results. Studies examining carp and goldfish horizontal cells loaded with the pH-sensitive dye 5-hexadecanoylaminofluorescein (HAF) reported an extracellular acidification on depolarization by glutamate or potassium. However, investigations using H+-selective microelectrodes report an extracellular alkalinization on depolarization of skate and catfish horizontal cells. These studies differed in the species and extracellular pH buffer used and the presence or absence of cobalt. We used both techniques to examine H+changes from isolated catfish horizontal cells under identical experimental conditions (1 mM HEPES, no cobalt). HAF fluorescence indicated an acidification response to high extracellular potassium or glutamate. However, a clear extracellular alkalinization was found using H+-selective microelectrodes under the same conditions. Confocal microscopy revealed that HAF was not localized exclusively to the extracellular surface, but rather was detected throughout the intracellular compartment. A high degree of colocalization between HAF and the mitochondrion-specific dye MitoTracker was observed. When HAF fluorescence was monitored from optical sections from the center of a cell, glutamate produced an intracellular acidification. These results are consistent with a model in which depolarization allows calcium influx, followed by activation of a Ca2+/H+plasma membrane ATPase. Our results suggest that HAF is reporting intracellular pH changes and that depolarization of horizontal cells induces an extracellular alkalinization, which may relieve H+-mediated inhibition of photoreceptor synaptic transmission.
Symptoms of Anxiety and Depression Are Correlates of Angina Pectoris by Recent History and an Ischemia-Positive Treadmill Test in Patients with Documented Coronary Artery Disease in the Pimi Study
Authors: Ketterer Mark W. , Bekkouche Nadine S. , Goldberg A. David , McMahon Robert P. , Krantz David S.
Published: November 2011

Objective. We tested the association of specific psychological characteristics in patients having stable coronary disease with the reporting of anginal symptoms during daily activities, and positive exercise testing. Methods. One hundred and ninety-six patients with documented CAD enrolled in the Psychophysiological Investigations of Myocardial Ischemia (PIMI) Study completed an anginal history questionnaire and a battery of psychometric tests. They also underwent standardized exercise treadmill tests. Results. Patients with a recent history of angina were more likely to be female, and had higher Beck Depression (P=.002), State Anxiety (P=.001), Trait Anxiety (P=.03), Harm Avoidance (P=.04) and Muscle Tension (P=.004) scores than patients who had no recent history of angina. Along with several treadmill variables indicating more severe disease state and reduced exercise tolerance, patients who developed angina on a positive treadmill test also displayed higher scores on the Beck Depression Inventory (P=.003) and State Anxiety (P=.004) scales. Conclusions. Several psychological characteristics, and most notably anxiety and depression, are strong correlates of recent angina and angina in the presence of ischemia provoked by treadmill testing.
Robotic Surgery in Gynecologic Oncology
Authors: DeBernardo Robert , Starks David , Barker Nichole , Armstrong Amy , Kunos Charles A.
Published: November 2011

Robotic surgery for the management of gynecologic cancers allows for minimally invasive surgical removal of cancer-bearing organs and tissues using sophisticated surgeon-manipulated, robotic surgical instrumentation. Early on, gynecologic oncologists recognized that minimally invasive surgery was associated with less surgical morbidity and that it shortened postoperative recovery. Now, robotic surgery represents an effective alternative to conventional laparotomy. Since its widespread adoption, minimally invasive surgery has become an option not only for the morbidly obese but for women with gynecologic malignancy where conventional laparotomy has been associated with significant morbidity. As such, this paper considers indications for robotic surgery, reflects on outcomes from initial robotic surgical outcomes data, reviews cost efficacy and implications in surgical training, and discusses new roles for robotic surgery in gynecologic cancer management.
Rayleigh Mixture Distribution
Authors: Karim Rezaul , Hossain Pear , Begum Sultana , Hossain Forhad
Published: November 2011

This paper presents Rayleigh mixtures of distributions in which the weight functions are assumed to be chi‐square, t and F sampling distributions. The exact probability density functions of the mixture of two correlated Rayleigh random variables have been derived. Different moments, characteristic functions, shape characteristics, and the estimates of the parameters of the proposed mixture distributions using method of moments have also been provided.
The Interaction of Plasma Sialylated and Desialylated Lipoproteins with Collagen from the Intima and Media of Uninvolved and Atherosclerotic Human Aorta
Authors: Sobenin Igor A. , Suprun Igor V. , Karagodin Vasiliy P. , Feoktistov Alexander S. , Melnichenko Alexandra A. , Orekhov Alexander N.
Published: November 2011

We have evaluated the binding of sialylated and desialylated lipoproteins to collagen isolated from the proteoglycan and musculoelastic layers of intima and media of uninvolved human aorta and atherosclerotic lesions. Comparing various collagen preparations from the uninvolved intima-media, the binding of sialylated apoB-containing lipoproteins was best to collagen from the intimal PG-rich layer. Binding of sialylated apoB-containing lipoproteins to collagen from this layer of fatty streak and fibroatheroma was 1.4- and 3.1-fold lower, respectively, in comparison with normal intima. Desialylated VLDL versus sialylated one exhibited a greater binding (1.4- to 3.0-fold) to all the collagen preparations examined. Desialylated IDL and LDL showed a higher binding than sialylated ones when collagen from the intimal layers of fibroatheroma was used. Binding of desialylated HDL to collagen from the intimal PG-rich layer of normal tissue, initial lesion, and fatty streak was 1.2- to 2.0-fold higher compared with sialylated HDL.
Nucleic Acid, Antibody, and Virus Culture Methods to Detect Xenotropic MLV-Related Virus in Human Blood Samples
Authors: Kearney M. F. , Lee K. , Bagni R. K. , Wiegand A. , Spindler J. , Maldarelli F. , Pinto P. A. , Linehan W. M. , Vocke C. D. , Delviks-Frankenberry K. A. , deVere White R. W. , Del Prete G. Q. , Mellors J. W. , Lifson J. D. , KewalRamani V. N. , Pathak V. K. , Coffin J. M. , Le Grice S. F. J.
Published: November 2011

The MLV-related retrovirus, XMRV, was recently identified and reported to be associated with both prostate cancer and chronic fatigue syndrome. At the National Cancer Institute-Frederick, MD (NCI-Frederick), we developed highly sensitive methods to detect XMRV nucleic acids, antibodies, and replication competent virus. Analysis of XMRV-spiked samples and/or specimens from two pigtail macaques experimentally inoculated with 22Rv1 cell-derived XMRV confirmed the ability of the assays used to detect XMRV RNA and DNA, and culture isolatable virus when present, along with XMRV reactive antibody responses. Using these assays, we did not detect evidence of XMRV in blood samples () or prostate specimens () from two independent cohorts of patients with prostate cancer. Previous studies detected XMRV in prostate tissues. In the present study, we primarily investigated the levels of XMRV in blood plasma samples collected from patients with prostate cancer. These results demonstrate that while XMRV-related assays developed at the NCI-Frederick can readily measure XMRV nucleic acids, antibodies, and replication competent virus, no evidence of XMRV was found in the blood of patients with prostate cancer.
Follicle Structure Influences the Availability of Oxygen to the Oocyte in Antral Follicles
Authors: Clark A. R. , Stokes Y. M.
Published: November 2011

The ability of an oocyte to successfully mature is highly dependent on intrafollicular conditions, including the size and structure of the follicle. Here we present a mathematical model of oxygen transport in the antral follicle. We relate mean oxygen concentration in follicular fluid of bovine follicles to the concentration in the immediate vicinity of the cumulus‐oocyte complex (COC). The model predicts that the oxygen levels within the antral follicle are dependent on the size and structure of the follicle and that the mean level of dissolved oxygen in follicular fluid does not necessarily correspond to that reaching the COC.
Room Temperature Ferromagnetism of (Mn,Fe) Codoped ZnO Nanowires Synthesized by Chemical Vapor Deposition
Authors: Chang Yongqin , Wang Pengwei , Sun Qingling , Wang Yongwei , Long Yi
Published: November 2011

(Mn,Fe) codoped ZnO nanowires were synthesized on silicon substrates in situ using a chemical vapor deposition method. The structure and property of the products were investigated by X-ray, electron microscopy, Raman, photoluminescence, and superconducting quantum interference device magnetometer. The doped nanowires are of pure wurtzite phase with single crystalline, and the elements distribute homogeneously in the doped nanowires. Photoluminescence spectrum of the doped nanowires is dominated by a deep-level emission with a negligible near-band-edge emission. The magnetic hysteresis curve with a coercive field of 35 Oe is clearly observed at 300 K, resulting from room-temperature ferromagnetic ordering in the (Mn,Fe) codoped ZnO nanowires, which has great potential applications for spintronics devices.
Animal Models of MS Reveal Multiple Roles of Microglia in Disease Pathogenesis
Authors: Gao Zhen , Tsirka Stella E.
Published: November 2011

Multiple sclerosis (MS) is a progressive inflammatory and demyelinating disease that affects more than 2.5 million people worldwide every year. Current therapies use mostly disease-modifying drugs, focusing on blocking and regulating systemic functions and the central nervous system (CNS) infiltration of immune cells; however, these therapies only attenuate or delay MS symptoms, but are not effective in halting the disease progression. More recent evidence indicated that regulation of inflammation within the CNS might be a better way to approach the treatment of the disease and microglia, the resident immune cells, may be a promising target of therapeutic studies. Microglia activation classically accompanies MS development, and regulation of microglia function changes the outcome of the disease. In this paper, we review the contributions of microglia to MS pathogenesis and discuss microglial functions in antigen presentation, cytokine release, and phagocytosis. We describe data both from animal and human studies. The significant impact of the timing, intensity, and differentiation fate of activated microglia is discussed, as they can modulate MS outcomes and potentially be critically modified for future therapeutic studies.