bluuebunny/crossref_metadata_2025 huggingface dataset:
Factors Associated with Differences between Conventional Contact Tracing and Molecular Epidemiology in Study of Tuberculosis Transmission and Analysis in the City of Barcelona, Spain
Authors: Borrell Sònia , Español Montserrat , Orcau Àngels , Tudó Griselda , March Francesca , Caylà Joan A. , Jansà Josep Maria , Alcaide Fernando , Martín-Casabona Núria , Salvadó Margarita , Martínez José Antonio , Vidal Rafael , Sánchez Francesca , Altet Neus , Coll Pere , González-Martín Juliàn
Published: November 2008

The aim of this study was to analyze the factors associated with conventional contact tracing (CCT) and molecular epidemiology (ME) methods in assessing tuberculosis (TB) transmission, comparing the populations studied and the epidemiological links established by both methods. Data were obtained from TB case and CCT registries, and ME was performed using IS6110-based restriction fragment length polymorphism (RFLP) analysis and mycobacterial interspersed repetitive unit 12 (MIRU12) typing as a secondary typing method. During two years (2003 and 2004), 892 cases of TB were reported, of which 687 (77%) were confirmed by culture. RFLP analysis was performed with 463 (67.4%) of the 687 isolated strains, and MIRU12 types in 75 strains were evaluated; 280 strains (60.5%) had a unique RFLP pattern, and 183 (39.5%) shared patterns, grouping into 65 clusters. CCT of 613 (68.7%) of 892 cases detected 44 clusters involving 101 patients. The results of both CCT and ME methods yielded 96 clusters involving 255 patients. The household link was the one most frequently identified by CCT (corresponding to 80.7% of the cases clustered by this method), whereas nonhousehold and unknown links were associated with 94.1% of the strains clustered by ME. When both methods were used in 351 cases (39.3%), they showed the same results in 214 cases (61%). Of the remainder, 106 (30.2%) were clustered only by ME, 19 (5.5%) were clustered only by CCT, and 12 (3.4%) were clustered by both methods but into different clusters. Patients with factors potentially associated with social problems were less frequently studied by CCT (P= 0.002), whereas patients of <15 years of age, most with negative cultures, were less frequently studied by ME (P= 0.005). Significant differences in the populations studied by ME versus CCT were observed, possibly explaining the scarce correlation found between the results of these methods. Moreover, ME allowed the detection of nonhousehold contact relationships, whereas CCT was more useful for tracing transmission chains involving patients of <15 years of age. In conclusion, the two methods are complementary, suggesting the need to improve the methodology of contact study protocols.
Borrelia carolinensissp. nov., a New (14th) Member of theBorrelia burgdorferiSensu Lato Complex from the Southeastern Region of the United States
Authors: Rudenko Nataliia , Golovchenko Maryna , Grubhoffer Libor , Oliver James H.
Published: November 2008

Approximately 118Borreliaisolates were cultured from a variety of rodents, birds, and ticks collected in the southern United States. In addition to a highly diverse group ofBorrelia bissettiistrains and a homogenous group ofBorrelia burgdorferisensu stricto strains, a group of 16 isolates with unusual characteristics was found. The isolates were cultured from ear biopsy samples of the rodentsPeromyscus gossypinusandNeotoma floridanatrapped at five localities in South Carolina. A multilocus sequence analysis of therrf-rrlintergenic spacer, 16S rRNA,fla,ospA, andp66genes were used to clarify the taxonomic status of the new group ofB. burgdorferisensu lato isolates. Thirteen species of theB. burgdorferisensu lato complex were used as controls. Unique restriction fragment length polymorphism patterns of therrf-rrlintergenic spacer region andflagene were recognized. Unique signature nucleotides were also found in the 16S rRNA gene. A phylogenetic analysis shows that the 16 new isolates cluster together but separately from the other species in theB. burgdorferisensu lato complex. Our data strongly support the recognition of the 16 isolates as a newB. burgdorferisensu lato species. We propose to name this genospecies “Borrelia carolinensis” with respect to the place of its currently known geographic location.
Single-Nucleotide Polymorphisms in Rv2629 Are Specific for
Mycobacterium tuberculosis
Genotypes Beijing and Ghana but Not Associated with Rifampin Resistance
Authors: Homolka Susanne , Köser Claudio , Archer John , Rüsch-Gerdes Sabine , Niemann Stefan
Published: November 2008

Sequence analysis of 58 multidrug-resistant
Mycobacterium tuberculosis
complex strains from Germany and 55 susceptible strains from a reference collection comprising major phylogenetic lineages confirmed that variations in Rv2629, 191A/C and 965C/T, are specific for genotypes Beijing and Ghana, respectively, but not involved in the development of rifampin (rifampicin) resistance.
Acute Respiratory Failure Involving an R Variant of
Mycobacterium abscessus
Authors: Catherinot Emilie , Roux Anne-Laure , Macheras Edouard , Hubert Dominique , Matmar Moussa , Dannhoffer Luc , Chinet Thierry , Morand Philippe , Poyart Claire , Heym Beate , Rottman Martin , Gaillard Jean-Louis , Herrmann Jean-Louis
Published: November 2008

We report the case of a cystic fibrosis patient colonized with a smooth-morphotype form of
Mycobacterium abscessus
who developed acute respiratory failure with the emergence of an isogenic rough (R) variant while he was recovering from peritonitis-induced shock. This report emphasizes the role of R forms in severe
M. abscessus
infections.
Comparison of Cefoxitin and Oxacillin Disk Diffusion Methods for Detection of
mecA
-Mediated Resistance in
Staphylococcus aureus
in a Large-Scale Study
Authors: Broekema Nicole M. , Van Tam T. , Monson Timothy A. , Marshall Steven A. , Warshauer David M.
Published: November 2008

The recommended breakpoints for the cefoxitin disk diffusion test for
Staphylococcus aureus
were recently modified. In this large-sample study, cefoxitin sensitivity and specificity compared to those of oxacillin were 97.3% and 100%, respectively. This study validated the new cefoxitin breakpoints for the detection of
mecA
-mediated resistance in
S. aureus
.
Development of an Oligonucleotide Array for Direct Detection of Fungi in Sputum Samples from Patients with Cystic Fibrosis
Authors: Bouchara Jean-Phillippe , Hsieh Hsin Yi , Croquefer Sabine , Barton Richard , Marchais Veronique , Pihet Marc , Chang Tsung Chain
Published: November 2008

Cystic fibrosis (CF) is the most common inherited genetic disease in Caucasian populations. Besides bacteria, many species of fungi may colonize the respiratory tract of these patients, sometimes leading to true respiratory infections. In this study, an oligonucleotide array capable of identifying 20 fungal species was developed to directly detect fungi in the sputum samples of CF patients. Species-specific oligonucleotide probes were designed from the internal transcribed spacer (ITS) regions of the rRNA operon and immobilized on a nylon membrane. The fungal ITS regions were amplified by PCR and hybridized to the array for species identification. The array was validated by testing 182 target strains (strains which we aimed to identify) and 141 nontarget strains (135 species), and a sensitivity of 100% and a specificity of 99.2% were obtained. The validated array was then used for direct detection of fungi in 57 sputum samples from 39 CF patients, and the results were compared to those obtained by culture. For 16 sputum samples, the results obtained by the array corresponded with those obtained by culture. For 33 samples, the array detected more fungal species than culture did, while the reverse was found for eight samples. The accuracy of the array for fungal detection in sputum samples was confirmed (or partially confirmed) in some samples by cloning and resequencing the amplified ITS fragments. The present array is a useful tool for both the simultaneous detection of multiple fungal species present in the sputa of CF patients and the identification of fungi isolated from these patients.
Presence of the KPC Carbapenemase Gene in
Enterobacteriaceae
Causing Bacteremia and Its Correlation with In Vitro Carbapenem Susceptibility
Authors: Marschall Jonas , Tibbetts Robert J. , Dunne W. Michael , Frye Jonathan G. , Fraser Victoria J. , Warren David K.
Published: November 2008

During 6 months, we obtained
Enterobacteriaceae
isolates from patients with gram-negative bacteremia at a 1,250-bed teaching hospital in St. Louis, MO, and compared carbapenem susceptibilities with the presence of
bla
KPC
, a transferable carbapenemase gene. Three (1.2%) out of 243 isolates were
bla
KPC
positive. Ertapenem nonsusceptibility had a low positive predictive value.
Respiratory Syncytial Virus Activates Innate Immunity through Toll-Like Receptor 2
Authors: Murawski Matthew R. , Bowen Glennice N. , Cerny Anna M. , Anderson Larry J. , Haynes Lia M. , Tripp Ralph A. , Kurt-Jones Evelyn A. , Finberg Robert W.
Published: November 2008

Respiratory syncytial virus (RSV) is a common cause of infection that is associated with a range of respiratory illnesses, from common cold-like symptoms to serious lower respiratory tract illnesses such as pneumonia and bronchiolitis. RSV is the single most important cause of serious lower respiratory tract illness in children <1 year of age. Host innate and acquired immune responses activated following RSV infection have been suspected to contribute to RSV disease. Toll-like receptors (TLRs) activate innate and acquired immunity and are candidates for playing key roles in the host immune response to RSV. Leukocytes express TLRs, including TLR2, TLR6, TLR3, TLR4, and TLR7, that can interact with RSV and promote immune responses following infection. Using knockout mice, we have demonstrated that TLR2 and TLR6 signaling in leukocytes can activate innate immunity against RSV by promoting tumor necrosis factor alpha, interleukin-6, CCL2 (monocyte chemoattractant protein 1), and CCL5 (RANTES). As previously noted, TLR4 also contributes to cytokine activation (L. M. Haynes, D. D. Moore, E. A. Kurt-Jones, R. W. Finberg, L. J. Anderson, and R. A. Tripp, J. Virol. 75:10730-10737, 2001, and E. A. Kurt-Jones, L. Popova, L. Kwinn, L. M. Haynes, L. P. Jones, R. A. Tripp, E. E. Walsh, M. W. Freeman, D. T. Golenbock, L. J. Anderson, and R. W. Finberg, Nat. Immunol. 1:398-401, 2000). Furthermore, we demonstrated that signals generated following TLR2 and TLR6 activation were important for controlling viral replication in vivo. Additionally, TLR2 interactions with RSV promoted neutrophil migration and dendritic cell activation within the lung. Collectively, these studies indicate that TLR2 is involved in RSV recognition and subsequent innate immune activation.
Hantaan Virus Nucleocapsid Protein Binds to Importin α Proteins and Inhibits Tumor Necrosis Factor Alpha-Induced Activation of Nuclear Factor Kappa B
Authors: Taylor Shannon L. , Frias-Staheli Natalia , García-Sastre Adolfo , Schmaljohn Connie S.
Published: November 2008

Hantaviruses such as Hantaan virus (HTNV) and Andes virus cause two human diseases, hemorrhagic fever with renal syndrome and hantavirus pulmonary syndrome, respectively. For both, disease pathogenesis is thought to be immunologically mediated and there have been numerous reports of patients with elevated levels of proinflammatory and inflammatory cytokines, including tumor necrosis factor alpha (TNF-α), in their sera. Multiple viruses have developed evasion strategies to circumvent the host cell inflammatory process, with one of the most prevalent being the disruption of nuclear factor kappa B (NF-κB) activation. We hypothesized that hantaviruses might also moderate host inflammation by interfering with this pathway. We report here that the nucleocapsid (N) protein of HTNV was able to inhibit TNF-α-induced activation of NF-κB, as measured by a reporter assay, and the activation of endogenous p65, an NF-κB subunit. Surprisingly, there was no defect in the degradation of the inhibitor of NF-κB (IκB) protein, nor was there any alteration in the level of p65 expression in HTNV N-expressing cells. However, immunofluorescence antibody staining demonstrated that cells expressing HTNV N protein and a green fluorescent protein-p65 fusion had limited p65 nuclear translocation. Furthermore, we were able to detect an interaction between HTNV N protein and importin α, a nuclear import molecule responsible for shuttling NF-κB to the nucleus. Collectively, our data suggest that HTNV N protein can sequester NF-κB in the cytoplasm, thus inhibiting NF-κB activity. These findings, which were obtained using cells transfected with cDNA representing the HTNV N gene, were confirmed using HTNV-infected cells.
Engagement of the CD4 Receptor Affects the Redistribution of Lck to the Immunological Synapse in Primary T Cells: Implications for T-Cell Activation during Human Immunodeficiency Virus Type 1 Infection
Authors: Nyakeriga Alice M. , Fichtenbaum Carl J. , Goebel Jens , Nicolaou Stella A. , Conforti Laura , Chougnet Claire A.
Published: November 2008

Understanding the molecular mechanisms underlying dysregulated immune responses in human immunodeficiency virus type 1 (HIV-1) infection is crucial for the control of HIV/AIDS. Despite the postulate that HIV envelope glycoprotein gp120-CD4 interactions lead to impaired T-cell responses, the precise mechanisms underlying such association are not clear. To address this, we analyzed Lck and F-actin redistribution into the immunological synapse in stimulated human primary CD4+T cells from HIV-1-infected donors. Similar experiments were performed with CD4+T cells from HIV-uninfected donors, which were exposed to anti-CD4 domain 1 antibodies, as an in vitro model of gp120-CD4 interactions, or aldithriol-inactivated HIV-1 virions before stimulation. CD4+T cells from HIV-infected patients exhibited a two- to threefold inhibition of both Lck and F-actin recruitment into the synapse, compared to cells from uninfected donors. Interestingly, defective recruitment of Lck was ameliorated following suppressive highly active antiretroviral therapy. Engagement of the CD4 receptor on T cells from HIV-uninfected donors before anti-CD3/CD28 stimulation led to similar defects. Furthermore, the redistribution of Lck into lipid rafts was abrogated by CD4 preengagement. Our results suggest that the engagement of CD4 by HIV gp120 prior to T-cell receptor stimulation leads to dysregulation of early signaling events and could consequently play an important role in impaired CD4+T-cell function.
mRNA Translation Regulation by the Gly-Ala Repeat of Epstein-Barr Virus Nuclear Antigen 1
Authors: Apcher Sebastien , Komarova Anastassia , Daskalogianni Chrysoula , Yin Yili , Malbert-Colas Laurence , Fåhraeus Robin
Published: November 2008

The glycine-alanine repeat (GAr) sequence of the Epstein-Barr virus-encoded EBNA-1 prevents presentation of antigenic peptides to major histocompatibility complex class I molecules. This has been attributed to its capacity to suppress mRNA translation incis. However, the underlying mechanism of this function remains largely unknown. Here, we have further investigated the effect of the GAr as a regulator of mRNA translation. Introduction of silent mutations in each codon of a 30-amino-acid GAr sequence does not significantly affect the translation-inhibitory capacity, whereas minimal alterations in the amino acid composition have strong effects, which underscores the observation that the amino acid sequence and not the mRNA sequence mediates GAr-dependent translation suppression. The capacity of the GAr to repress translation is dose and position dependent and leads to a relative accumulation of preinitiation complexes on the mRNA. Taken together with the surprising observation that fusion of the 5′ untranslated region (UTR) of the c-myc mRNA to the 5′ UTR of GAr-carrying mRNAs specifically inactivates the effect of the GAr, these results indicate that the GAr targets components of the translation initiation process. We propose a model in which the nascent GAr peptide delays the assembly of the initiation complex on its own mRNA.
HLA-Associated Clinical Progression Correlates with Epitope Reversion Rates in Early Human Immunodeficiency Virus Infection
Authors: Duda A. , Lee-Turner L. , Fox J. , Robinson N. , Dustan S. , Kaye S. , Fryer H. , Carrington M. , McClure M. , Mclean A. R. , Fidler S. , Weber J. , Phillips R. E. , Frater A. J.
Published: November 2008

Human immunodeficiency virus type 1 (HIV-1) can evade immunity shortly after transmission to a new host but the clinical significance of this early viral adaptation in HIV infection is not clear. We present an analysis of sequence variation from a longitudinal cohort study of HIV adaptation in 189 acute seroconverters followed for up to 3 years. We measured the rates of variation within well-defined epitopes to determine associations with the HLA-linked hazard of disease progression. We found early reversion across both thegagandpolgenes, with a 10-fold faster rate of escape ingag(2.2 versus 0.27 forward mutations/1,000 amino acid sites). For most epitopes (23/34), variation in the HLA-matched and HLA-unmatched controls was similar. For a minority of epitopes (8/34, and generally associated with HLA class I alleles that confer clinical benefit), new variants appeared early and consistently over the first 3 years of infection. Reversion occurred early at a rate which was HLA-dependent and correlated with the HLA class 1-associated relative hazard of disease progression and death (P= 0.0008), reinforcing the association between strong cytotoxic T-lymphocyte responses, viral fitness, and disease status. These data provide a comprehensive overview of viral adaptation in the first 3 years of infection. Our findings of HLA-dependent reversion suggest that costs are borne by some escape variants which may benefit the host, a finding contrary to a simple immune evasion paradigm. These epitopes, which are both strongly and frequently recognized, and for which escape involves a high cost to the virus, have the potential to optimize vaccine design.
Specific Inhibition of the PKR-Mediated Antiviral Response by the Murine Cytomegalovirus Proteins m142 and m143
Authors: Budt Matthias , Niederstadt Lars , Valchanova Ralitsa S. , Jonjić Stipan , Brune Wolfram
Published: November 2008

Double-stranded RNA (dsRNA) produced during viral infection activates several cellular antiviral responses. Among the best characterized is the shutoff of protein synthesis mediated by the dsRNA-dependent protein kinase (PKR) and the oligoadenylate synthetase (OAS)/RNase L system. As viral replication depends on protein synthesis, many viruses have evolved mechanisms for counteracting the PKR and OAS/RNase L pathways. The murine cytomegalovirus (MCMV) proteins m142 and m143 have been characterized as dsRNA binding proteins that inhibit PKR activation, phosphorylation of the translation initiation factor eIF2α, and a subsequent protein synthesis shutoff. In the present study we analyzed the contribution of the PKR- and the OAS-dependent pathways to the control of MCMV replication in the absence or presence of m142 and m143. We show that the induction of eIF2α phosphorylation during infection with an m142- and m143-deficient MCMV is specifically mediated by PKR, not by the related eIF2α kinases PERK or GCN2. PKR antagonists of vaccinia virus (E3L) or herpes simplex virus (γ34.5) rescued the replication defect of an MCMV strain with deletions of both m142 and m143. Moreover, m142 and m143 bound to each other and interacted with PKR. By contrast, an activation of the OAS/RNase L pathway by MCMV was not detected in the presence or absence of m142 and m143, suggesting that these viral proteins have little or no influence on this pathway. Consistently, an m142- and m143-deficient MCMV strain replicated to high titers in fibroblasts lacking PKR but did not replicate in cells lacking RNase L. Hence, the PKR-mediated antiviral response is responsible for the essentiality of m142 and m143.
Infectious Molecular Clones of Adeno-Associated Virus Isolated Directly from Human Tissues
Authors: Schnepp Bruce C. , Jensen Ryan L. , Clark K. Reed , Johnson Philip R.
Published: November 2008

Adeno-associated virus (AAV) replication and biology have been extensively studied using cell culture systems, but there is precious little known about AAV biology in natural hosts. As part of our ongoing interest in the in vivo biology of AAV, we previously described the existence of extrachromosomal proviral AAV genomes in human tissues. In the current work, we describe the molecular structure of infectious DNA clones derived directly from these tissues. Sequence-specific linear rolling-circle amplification was utilized to isolate clones of native circular AAV DNA. Several molecular clones containing unit-length viral genomes directed the production of infectious wild-type AAV upon DNA transfection in the presence of adenovirus help. DNA sequence analysis of the molecular clones revealed the ubiquitous presence of a double-D inverted terminal repeat (ITR) structure, which implied a mechanism by which the virus is able to maintain ITR sequence continuity and persist in the absence of host chromosome integration. These data suggest that the natural life cycle of AAV, unlike that of retroviruses, might not have genome integration as an obligatory component.
Signaling through Toll-Like Receptors Induces Murine Gammaherpesvirus 68 Reactivation In Vivo
Authors: Gargano Lisa M. , Forrest J. Craig , Speck Samuel H.
Published: November 2008

Murine gammaherpesvirus 68 (MHV68) establishes a lifelong infection in mice and is used as a model pathogen to study the role of viral and host factors in chronic infection. The maintenance of chronic MHV68 infection, at least in some latency reservoirs, appears to be dependent on the capacity of the virus to reactivate from latency in vivo. However, the signals that lead to MHV68 reactivation in vivo are not well characterized. Toll-like receptors (TLRs), by recognizing the specific patterns of microbial components, play an essential role in the activation of innate immunity. In the present study, we investigated the capacity of TLR ligands to induce MHV68 reactivation, both in vitro and in vivo. The stimulation of latently infected B cell lines with ligands for TLRs 3, 4, 5, and 9 enhanced MHV68 reactivation; the ex vivo stimulation of latently infected primary splenocytes, recovered from infected mice, with poly(I:C), lipopolysaccharide, flagellin, or CpG DNA led to early B-cell activation, B-cell proliferation, and a significant increase in the frequency of latently infected cells reactivating the virus. In vivo TLR stimulation also induced B-cell activation and MHV68 reactivation, resulting in heightened levels of virus replication in the lungs which correlated with an increase in MHV68-specific CD8
+
T-cell responses. Importantly, TLR stimulation also led to an increase in MHV68 latency, as evidenced by an increase in viral genome-positive cells 2 weeks post-in vivo stimulation by specific TLR ligands. Thus, these data demonstrate that TLR stimulation can drive MHV68 reactivation from latency and suggests that periodic pathogen exposure may contribute to the homeostatic maintenance of chronic gammaherpesvirus infection through stimulating virus reactivation and reseeding latency reservoirs.
Estimating the Stoichiometry of Human Immunodeficiency Virus Entry
Authors: Magnus Carsten , Rusert Peter , Bonhoeffer Sebastian , Trkola Alexandra , Regoes Roland R.
Published: November 2008

To enter target cells, human immunodeficiency virus (HIV) first attaches to the cells and fuses with the cell membrane. Attachment and fusion involve envelope glycoprotein trimers on the surface of the virion and the CD4 receptor and chemokine coreceptors on the surface of the target cell. The stoichiometry of entry, that is, the number of bonds between such trimers and CD4 that are required for infection, is unknown. Pseudotyped virions that express mixed trimers consisting of functional and nonfunctional envelope proteins have been used to study how many trimer-receptor interactions are required for virus entry. However, to extract information on the stoichiometry of entry from data generated in in vitro infectivity assays with such viruses, mathematical models are required. Here, we describe mathematical models that can be used to infer the stoichiometry of entry. By fitting our simplest model to previously published data (X. Yang, S. Kurteva, X. Ren, S. Lee, and J. Sodroski, J. Virol. 79: 12132-12147, 2005), we estimated that the number of trimer-receptor interactions required for HIV to infect a target cell is approximately eight, which is higher than previous estimates. We also consider model extensions that explain some systematic deviations of the data from the prediction of the simplest model. However, these extended models yield very different estimates of the stoichiometry of entry ranging from 2 to 19. These results strongly suggest that, based on our present knowledge of HIV entry, the stoichiometry of this process cannot be reliably estimated. Our study identifies parameters that need to be defined to render the estimation of the stoichiometry of HIV entry possible.
Mechanism of mda-5 Inhibition by Paramyxovirus V Proteins
Authors: Childs K. S. , Andrejeva J. , Randall R. E. , Goodbourn S.
Published: November 2008

The RNA helicases encoded by melanoma differentiation-associated gene 5 (mda-5) and retinoic acid-inducible gene I (RIG-I) detect foreign cytoplasmic RNA molecules generated during the course of a virus infection, and their activation leads to induction of type I interferon synthesis. Paramyxoviruses limit the amount of interferon produced by infected cells through the action of their V protein, which binds to and inhibits mda-5. Here we show that activation of both mda-5 and RIG-I by double-stranded RNA (dsRNA) leads to the formation of homo-oligomers through self-association of the helicase domains. We identify a region within the helicase domain of mda-5 that is targeted by all paramyxovirus V proteins and demonstrate that they inhibit activation of mda-5 by blocking dsRNA binding and consequent self-association. In addition to this commonly targeted domain, some paramyxovirus V proteins target additional regions of mda-5. In contrast, V proteins cannot bind to RIG-I and consequently have no effect on the ability of RIG-I to bind dsRNA or to form oligomers.
Neutralization-Sensitive R5-Tropic Simian-Human Immunodeficiency Virus SHIV-2873Nip, Which Carries
env
Isolated from an Infant with a Recent HIV Clade C Infection
Authors: Siddappa Nagadenahalli B. , Song Ruijiang , Kramer Victor G. , Chenine Agnès-Laurence , Velu Vijayakumar , Ong Helena , Rasmussen Robert A. , Grisson Ricky D. , Wood Charles , Zhang Hong , Kankasa Chipeppo , Amara Rama Rao , Else James G. , Novembre Francis J. , Montefiori David C. , Ruprecht Ruth M.
Published: November 2008

Human immunodeficiency virus clade C (HIV-C) accounts for >56% of all HIV infections worldwide. To investigate vaccine safety and efficacy in nonhuman primates, a pathogenic, R5-tropic, neutralization-sensitive simian-human immunodeficiency virus (SHIV) carrying HIV-C
env
would be desirable. We have constructed SHIV-2873Ni, an R5-tropic SHIV carrying a primary pediatric HIV-C
env
gene isolated from a 2-month-old Zambian infant, who died within 1 year of birth. SHIV-2873Ni was constructed using SHIV-1157ipd3N4 (R. J. Song, A. L. Chenine, R. A. Rasmussen, C. R. Ruprecht, S. Mirshahidi, R. D. Grisson, W. Xu, J. B. Whitney, L. M. Goins, H. Ong, P. L. Li, E. Shai-Kobiler, T. Wang, C. M. McCann, H. Zhang, C. Wood, C. Kankasa, W. E. Secor, H. M. McClure, E. Strobert, J. G. Else, and R. M. Ruprecht. J. Virol. 80:8729-8738, 2006) as the backbone, since the latter contains additional NF-κB sites in the long terminal repeats to enhance viral replicative capacity. The parental virus, SHIV-2873Ni, was serially passaged through five rhesus monkeys (RMs); SHIV-2873Nip, the resulting passaged virus, was reisolated from the fourth recipient about 1 year postinoculation. SHIV-2873Nip was replication competent in RM peripheral blood mononuclear cells of all random donors tested and was exclusively R5 tropic, and its
env
gene clustered with HIV-C by phylogenetic analysis; its high sensitivity to neutralization led to classification as a tier 1 virus. Indian-origin RMs were inoculated by different mucosal routes, resulting in high peak viral RNA loads. Signs of virus-induced disease include depletion of gut CD4
+
T lymphocytes, loss of memory T cells in blood, and thrombocytopenia that resulted in fatal cerebral hemorrhage. SHIV-2873Nip is a highly replication-competent, mucosally transmissible, pathogenic R5-tropic virus that will be useful to study viral pathogenesis and to assess the efficacy of immunogens targeting HIV-C Env.
Repair of the U
L
21 Locus in Pseudorabies Virus Bartha Enhances the Kinetics of Retrograde, Transneuronal Infection In Vitro and In Vivo
Authors: Curanović D. , Lyman M. G. , Bou-Abboud C. , Card J. P. , Enquist L. W.
Published: November 2008

The attenuated pseudorabies virus (PRV) strain Bartha contains several characterized mutations that affect its virulence and ability to spread through neural circuits. This strain contains a small genomic deletion that abrogates anterograde spread and is widely used as a retrograde-restricted neural circuit tracer. Previous studies showed that the retrograde-directed spread of PRV Bartha is slower than that of wild-type PRV. We used compartmented neuronal cultures to characterize the retrograde defect and identify the genetic basis of the phenotype. PRV Bartha is not impaired in retrograde axonal transport, but transneuronal spread among neurons is diminished. Repair of the U
L
21 locus with wild-type sequence restored efficient transneuronal spread both in vitro and in vivo. It is likely that mutations in the Bartha U
L
21 gene confer defects that affect infectious particle production, causing a delay in spread to presynaptic neurons and amplification of infection. These events manifest as slower kinetics of retrograde viral spread in a neural circuit.
Inactivated Simian Immunodeficiency Virus-Pulsed Autologous Fresh Blood Cells as an Immunotherapy Strategy
Authors: Mason Rosemarie D. , Alcantara Sheilajen , Peut Viv , Loh Liyen , Lifson Jeffrey D. , De Rose Robert , Kent Stephen J.
Published: November 2008

Practical immunotherapies for human immunodeficiency virus infection are needed. We evaluated inactivated simian immunodeficiency virus (SIV) pulsed onto fresh peripheral blood mononuclear cells in 12 pigtail macaques with chronic SIV
mac251
infection for T-cell immunogenicity in a randomized cross-over design study. The immunotherapy was safe and convincingly induced high levels of SIV-specific CD4
+
T-cell responses (mean, 5.9% ± 1.3% of all CD4
+
T cells) and to a lesser extent SIV-specific CD8
+
T-cell responses (mean, 0.7% ± 0.4%). Responses were primarily directed toward Gag and less frequently toward Env but not Pol or regulatory/accessory SIV proteins. T-cell responses against Gag were generally broad and polyfunctional, with a mean of 2.7 CD4
+
T-cell epitopes mapped per animal and more than half of the SIV Gag-specific CD4
+
T cells expressing three or more effector molecules. The immunogenicity was comparable to that found in previous studies of peptide-pulsed blood cells. Despite the high-level immunogenicity, no reduction in viral load was observed in the chronically viremic macaques. This contrasts with our studies of immunization with peptide-pulsed blood cells during early SIV infection in macaques. Future studies of inactivated virus-pulsed blood cell immunotherapy during early infection of patients receiving antiretroviral therapy are warranted.
Posterior lamellar keratoplasty—comparison of deep lamellar endothelial keratoplasty and Descemet stripping automated endothelial keratoplasty in the same patients: a patient’s perspective
Authors: Bahar I , Sansanayudh W , Levinger E , Kaiserman I , Srinivasan S , Rootman D
Published: November 2008

Aim:

To evaluate patients’ perspectives on endothelial keratoplasty and to compare the outcomes of deep lamellar endothelial keratoplasty (DLEK) and Descemet stripping automated endothelial keratoplasty (DSAEK), performed in the same patients.

Methods:

A fellow eye, comparative retrospective case series. The records of 14 patients (28 eyes) who underwent DLEK in one eye and DSAEK surgery in their fellow eye between 2003 and 2007 were reviewed. Two patients were excluded from the study. Both these techniques were compared for intra- and postoperative complications, visual and refractive outcomes including higher-order ocular aberrations (HOA). Patient satisfaction for both procedures was prospectively evaluated using a subjective questionnaire.

Results:

Nine (75%) of the 12 patients perceived better vision in the DSAEK operated eye. Eight (66.6%) of the patients reported faster recovery following DSAEK. Ten (83%) of them preferred the outcomes of the DSAEK surgery. The intra- and postoperative complications were comparable between both procedures. There was no significant difference in visual outcomes between the procedures. However, the DLEK procedure was associated with a significantly higher degree (p<0.05) of HOA. Endothelial cell loss was similar following DLEK and DSAEK.

Conclusions:

We conclude that most patients prefer the DSAEK operation, although there are no differences in visual outcomes between DLEK and DSAEK. Avoidance of surgery-induced hyperopia and HOA is the main benefit of the DSAEK technique.
Recovery of corneal irregular astigmatism, ocular higher-order aberrations, and contrast sensitivity after discontinuation of overnight orthokeratology
Authors: Hiraoka T , Okamoto C , Ishii Y , Okamoto F , Oshika T
Published: November 2008

Aims:

To examine prospectively the recovery of various parameters after discontinuation of overnight orthokeratology.

Methods:

Seventeen subjects undergoing orthokeratology for 12 months were examined. Refraction, corneal topography, wavefront aberrometry, a visual acuity test and a contrast sensitivity test were performed at baseline, 12 months after commencement of the procedure, and 1 week and 1 month after discontinuation of the treatment. Asymmetry and higher-order irregularity components were calculated using a Fourier analysis of the corneal topography data. Contrast sensitivity was assessed at four spatial frequencies, and the area under the log contrast sensitivity function (AULCSF) was calculated.

Results:

Orthokeratology significantly reduced manifest refraction (p<0.0001, Dunnett test) and significantly improved uncorrected visual acuity (UCVA) at 12 months after commencement of the procedure (p<0.0001). Asymmetry and higher-order irregularity components increased significantly (p<0.0001, p = 0.0032, respectively), and third- and fourth-order aberrations also increased significantly (p<0.0001). The treatment resulted in significant decreases in AULCSF (p = 0.0004). After discontinuing lens wear, all parameters, such as refraction, UCVA, asymmetry, higher-order irregularity, third-order aberration, fourth-order aberration and AULCSF, returned to the baseline level at 1 week.

Conclusion:

This study confirmed that the effect of orthokeratology is completely reversible in light of optical quality of the eye and quality of vision as well as refraction and visual acuity.
Recurrent ectasia in corneal grafts and outcomes of repeat keratoplasty for keratoconus
Authors: Patel S V , Malta J B , Banitt M R , Mian S I , Sugar A , Elner V M , Tester R A , Farjo Q A , Soong H K
Published: November 2008

Aim:

To analyse cases of recurrent ectasia in donor corneas after penetrating keratoplasty (PK) for keratoconus.

Methods:

Data on 25 patients (36 eyes) with recurrent ectasia were retrospectively analysed in this study. The main outcome measures were time to development of recurrent ectasia after first PK for keratoconus, change in keratometric sphere and astigmatism between final suture removal and development of recurrent ectasia, status of regrafts for recurrent ectasia, and histopathology of grafts excised for recurrent ectasia.

Results:

The age at first PK was 32.6 (SD 8.5) years, and ectasia developed 21.9 (7.0) years after PK. The mean keratometric sphere and cylinder increased by 4.2 D and 3.0 D, respectively, between final suture removal and diagnosis of recurrent ectasia. Ectasia was often preceded by thinning without bulging of the recipient stroma at the graft–host junction. Fifteen eyes (13 patients) were regrafted for recurrent ectasia, and histopathology of the excised grafts showed changes characteristic of keratoconus in the donor tissue in all cases. Two regrafts (two eyes of one patient) developed ectasia again, with one eye requiring a third PK to improve vision.

Conclusions:

Recurrent ectasia was diagnosed on average two decades after PK. Ectatic changes were often bilateral and occasionally recurred after regrafting, suggesting that host cellular and/or biochemical factors may be responsible. Repeat PK for recurrent ectasia is successful in the intermediate term.
The gluteal triangle: a clinical patho-anatomical approach to the diagnosis of gluteal pain in athletes
Authors: Franklyn-Miller A , Falvey E , McCrory P
Published: November 2008

Gluteal pain is a common presentation in sports medicine. The aetiology of gluteal pain is varied, it may be referred from the lower back, mimic other pathology and refer to the hip or the groin. The complex anatomy of the buttock and pelvis, variability of presentation and non specific nature of signs and symptoms make the diagnostic process difficult. To date the approaches to this problem have focused on individual pathologies.

The paper proposes a novel educational system based on patho-anatomic concepts. Anatomical reference points were selected to form a diagnostic triangle, which provides the discriminative power to restrict the differential diagnosis, and form the basis of ensuing investigation.

This paper forms part of a series addressing the three dimensional nature of proximal lower limb pathology. The 3G approach (groin, gluteal and greater trochanter triangles) acknowledges this, permitting the clinician to move throughout the region, considering pathologies appropriately. These papers should be read in conjunction with one another in order to fully understand the conceptual approach.
The greater trochanter triangle; a pathoanatomic approach to the diagnosis of chronic, proximal, lateral, lower pain in athletes
Authors: Falvey E C , Franklyn-Miller A , McCrory P R
Published: November 2008

Chronic pain experienced in the proximal, lateral, lower limb may arise from the femoro-acetabular joint, from the muscles and tendons that act upon it, from any of the structures that traverse the area, and from more remote structures such as the lumbar spine.

The aetiology of pathology in this area is not confined to either trauma or overuse. As a result many different sporting activities may have a causal role.

Without a clear clinical/pathological diagnosis, the subsequent management of chronic groin pain is difficult. The combination of complex anatomy, variability of presentation and the non-specific nature of the signs and symptoms makes the diagnostic process problematic.

The paper proposes a novel educational model based on pathoanatomic concepts. Anatomical reference points were selected to form a triangle, which provides the discriminative power to restrict the differential diagnosis, and form the basis of ensuing investigation.

This paper forms part of a series addressing the three-dimensional nature of proximal lower limb pathology. The 3G approach (groin, gluteal, and greater trochanter triangles) acknowledges this, permitting the clinician to move throughout the region, considering pathologies appropriately.
Sonographically guided intratendinous injections of hyperosmolar dextrose/lidocaine: a pilot study for the treatment of chronic plantar fasciitis
Authors: Ryan M B , Wong A D , Gillies J H , Wong J , Taunton J E
Published: November 2008

Objective:

To report on the effectiveness of sonographically guided injections of hyperosmolar dextrose at reducing the pain associated with chronic plantar fasciitis.

Design:

Case series.

Setting:

Ultrasound division of St Paul’s Hospital.

Patients:

20 referrals (3 men, 17 women; age 51 (SD 13) years) from local sports medicine primary care practitioners who had failed previous conservative treatments.

Interventions:

A 27-gauge needle administered a 25% dextrose/lidocaine solution under sonographic guidance at 6 week intervals returning for a median of three consultations.

Main outcome measures:

Visual analogue scale (VAS) items for pain levels at rest (VAS1), activities of daily living (VAS2), and during or after physical activity (VAS3) were recorded at baseline and at the final treatment consultation (post-test). A telephone interview conducted an average of 11.8 months after the post-test consultation provided a measure of long-term follow-up.

Results:

16 patients reported a good to excellent outcome, while the symptoms in 4 patients were unchanged. There was a significant decrease (p<0.001) in all mean VAS items from pre-test to post-test: VAS1 (36.8 (SD 25.6) to 10.3 (10.9)), VAS2 (74.7 (20.8) to 25.0 (27.7)) and VAS3 (91.6 (9.2) to 38.7 (35.1)) and there were no apparent changes after the follow-up interview.Conclusions:Sonographically guided dextrose injections showed a good clinical response in patients with chronic plantar fasciitis insofar as pain was reduced during rest and activity. Further studies including a control group are needed to validate these outcomes.
State anxiety and subjective well-being responses to acute bouts of aerobic exercise in patients with depressive and anxiety disorders
Authors: Knapen J , Sommerijns E , Vancampfort D , Sienaert P , Pieters G , Haake P , Probst M , Peuskens J
Published: November 2008

Objective:

Acute aerobic exercise is associated with a reduction in state anxiety and an improvement in subjective well-being. The objective of the present study was to contrast the effects of aerobic exercise at self-selected intensity versus prescribed intensity on state anxiety and subjective well-being (negative affect, positive well-being and fatigue) in patients with depressive and/or anxiety disorders. In addition, the potential impact of heart rate feedback was assessed.

Methods:

Nineteen men and 29 women performed three test conditions on a bicycle ergometer during 20 minutes: two tests at self-selected intensity; one with and another without heart rate feedback, and a third test at the prescribed intensity of 50% of the maximal heart rate reserve according to Karvonen. Tests were executed in random order. State anxiety and subjective well-being were evaluated using the state anxiety inventory and the subjective exercise experiences scale.

Results:

After 20 minutes cycling, patients showed significantly decreased state anxiety and negative affect in the three conditions. The magnitude of the reduction did not differ significantly between the three conditions. Only cycling at self-selected intensity enhanced positive well-being. Cycling at 50% of the maximal heart rate reserve decreased fatigue, whereas cycling at self-selected intensity increased fatigue.

Conclusions:

The response in state anxiety and negative affect was unaffected by the type of aerobic exercise. Self-selected intensity influenced exercise-induced changes in positive well-being and fatigue in a positive and negative way, respectively.
Eccentric calf muscle exercise produces a greater acute reduction in Achilles tendon thickness than concentric exercise
Authors: Grigg N L , Wearing S C , Smeathers J E
Published: November 2008

Objective:

To investigate the acute effects of isolated eccentric and concentric calf muscle exercise on Achilles tendon sagittal thickness.

Design:

Within-subject, counterbalanced, mixed design.

Setting:

Institutional.

Participants:

11 healthy, recreationally active male adults.

Interventions:

Participants performed an exercise protocol, which involved isolated eccentric loading of the Achilles tendon of a single limb and isolated concentric loading of the contralateral, both with the addition of 20% bodyweight.

Main outcome measurements:

Sagittal sonograms were acquired prior to, immediately following and 3, 6, 12 and 24 h after exercise. Tendon thickness was measured 2 cm proximal to the superior aspect of the calcaneus.

Results:

Both loading conditions resulted in an immediate decrease in normalised Achilles tendon thickness. Eccentric loading induced a significantly greater decrease than concentric loading despite a similar impulse (−0.21 vs −0.05, p<0.05). Post-exercise, eccentrically loaded tendons recovered exponentially, with a recovery time constant of 2.5 h. The same exponential function did not adequately model changes in tendon thickness resulting from concentric loading. Even so, recovery pathways subsequent to the 3 h time point were comparable. Regardless of the exercise protocol, full tendon thickness recovery was not observed until 24 h.

Conclusions:

Eccentric loading invokes a greater reduction in Achilles tendon thickness immediately after exercise but appears to recover fully in a similar time frame to concentric loading.
Co-existent medial collateral ligament injury seen following transient patellar dislocation: observations at magnetic resonance imaging
Authors: Quinlan J F , Farrelly C , Kelly G , Eustace S
Published: November 2008

This study reports on a series of patients who were diagnosed as having had a transient lateral patellar dislocation by magnetic resonance imaging (MRI). The images were reviewed with specific reference to the medial collateral ligament (MCL), a heretofore undescribed concomitant injury. Eighty patients were diagnosed on MRI as having had transient lateral patellar dislocation. Their mean age was 23.9 years (SD 7.5). Forty patients (50.0%) had co-existent MCL injuries. These injuries were classified as grade 1 (n = 20), grade 2 (n = 17) and grade 3 (n = 3). These results suggest that MCL injury commonly accompanies transient lateral patella dislocation, most likely due to a shared valgus injury. It appears to occur more commonly in male patients and if unidentified may explain both delayed recovery and persistent morbidity in more severe cases. In this setting, without specifically excluding co-existent MCL injury, the current vogue for early rehabilitation should be adopted with caution.
Physical activity habits of doctors and medical students influence their counselling practices
Authors: Lobelo F , Duperly J , Frank E
Published: November 2008

Doctors are well positioned to provide physical activity (PA) counselling to patients. They are a respected source of health-related information and can provide continuing preventive counselling feedback and follow-up; they may have ethical obligations to prescribe PA. Several barriers to PA counselling exist, including insufficient training and motivation of doctors and improvable, personal PA habits. Rates of exercise counselling by doctors remain low; only 34% of US adults report exercise counselling at their last medical visit. In view of this gap, one of the US health objectives for 2010 is increasing the proportion of patients appropriately counselled about health behaviours, including exercise/PA. Research shows that clinical providers who themselves act on the advice they give provide better counselling and motivation of their patients to adopt such health advice.

In summary, there is compelling evidence that the health of doctors matters and that doctors’ own PA practices influence their clinical attitudes towards PA. Medical schools need to increase the proportion of students adopting and maintaining regular PA habits to increase the rates and quality of future PA counselling delivered by doctors.