bluuebunny/crossref_metadata_2025 huggingface dataset:
Ecosystem engineers activate mycorrhizal mutualism in salt marshes
Authors: Daleo Pedro , Fanjul Eugenia , Casariego Agustina Mendez , Silliman Brian R. , Bertness Mark D. , Iribarne Oscar
Published: July 2007

Theory predicts that ecosystem engineers should have their most dramatic effects when they enable species, through habitat amelioration, to live in zones where physical and biological conditions would otherwise suppress or limit them. Mutualisms between mycorrhizal fungi and plants are key determinants of productivity and biodiversity in most terrestrial systems, but are thought to be unimportant in wetlands because anoxic sediments exclude fungal symbionts. Our field surveys revealed arbuscular mycorrhizal associations on salt marsh plant roots, but only in the presence of crabs that oxygenate soils as a by‐product of burrowing. Field experiments demonstrate that fungal colonization is dependent on crab burrowing and responsible for nearly 35% of plant growth. These results highlight ecosystem engineers as ecological linchpins that can activate and maintain key mutualisms between species. Our findings align salt marshes with other important biogenic habitats whose productivity is reliant on mutualisms between the primary foundation species and micro‐organisms.
Portfolio Flows to Emerging Capital Markets: Do Corporate Transparency and Public Governance Matter?
Authors: CHIPALKATTI NIRANJAN , LE QUAN V. , RISHI MEENAKSHI
Published: July 2007

This paper focuses on flows to emerging capital markets (ECMs) and examines the importance of corporate transparency and public governance in attracting portfolio flows to ECMs. This paper's empirical investigation centers on the hypothesis that ceteris paribus, ECMs with better quality accounting standards and good governance attract higher levels of portfolio equity and bond flows. To assess the incremental impact of each of these factors, a pooled time series, cross‐sectional model was econometrically tested for 17 ECMS over the 1998–2002 time period. Our empirical analysis demonstrates a positive association between public governance, corporate transparency, and portfolio flows after controlling for other macroeconomic factors. The results suggest that good public governance and high accounting quality are important determinants of portfolio flows to ECMs. Finally, the paper establishes that while portfolio equity flows are significantly attracted to ECMs with strong democratic institutions, there is no significant association between portfolio bond flows and the presence of democratic institutions.
Nationwide hospitalization costs of skin melanoma and non‐melanoma skin cancer in Germany
Authors: Stang A , Stausberg J , Boedeker W , Kerek‐Bodden H , Jöckel K‐H
Published: July 2007

Introduction  Non‐melanoma skin cancer (NMSC), in contrast to skin melanoma (MEL), is considered a negligible health problem because mortality of NMSC is low. The aim of this study was to provide insights into the burden of NMSC and MEL by analysing nationwide skin cancer hospitalization data and data from a dermatologist panel of Germany. We wanted to estimate hospitalization costs due to skin cancer in Germany.

Material and methods  We analysed the most recent nationwide hospitalization data from 2003 and estimated hospitalization costs due to MEL and NMSC. We estimated the annual number of private dermatologist practice visits in Germany due to skin cancer.

Results  In 2003, 20 455 melanoma‐related and 41 929 NMSC‐related hospitalizations occurred in Germany. Age‐standardized hospitalization rates for NMSC were 2.5‐fold and 1.8‐fold higher among men and women than the rates for MEL, respectively. The age‐specific proportions of hospitalizations for NMSC in relation to all cancer‐related hospitalizations increased within the age range of 65 years and more. Among people aged 90 years and more, 14% of all cancer‐related hospitalizations were due to NMSC. Estimated annual hospitalization costs for MEL were €50 to 60 million, and those for NMSC were €105 to 130 million. The estimated number of private dermatologist practice visits in Germany 2003 is considerably higher for NMSC than MEL

Conclusions  Analyses of hospitalizations data and data from private dermatologists give NMSC higher public health relevance than can be obtained from consideration of death statistics.
Increased micronucleus frequency in phytohaemagglutinin‐stimulated blood cells of patients with vitiligo
Authors: Donmez‐Altuntas H , Sut Z , Ferahbas A , Hamurcu Z , Demirtas H
Published: July 2007

Background  Vitiligo is a relatively common, acquired pigmentary disorder characterized by areas of depigmented skin resulting from loss of melanocytes in the epidermis. Although several hypotheses have been proposed for the aetiology and pathogenesis of vitiligo, the cause of vitiligo remains unclear.

Objective  To evaluate spontaneous micronucleus (MN) frequency using the cytokinesis block MN assay to determine damages at the DNA or chromosome level in phytohaemagglutinin (PHA)‐stimulated blood cells of patients with vitiligo and healthy control subjects.

Methods  Peripheral blood samples were obtained and cultured from 21 patients with vitiligo (mean age: 21.48 ± 9.78 years) and 21 age‐ and sex‐matched healthy control subjects (mean age: 21.52 ± 9.80 years). MN values were scored in binucleated cells obtained from whole‐blood cultures of patients and control subjects.

Results  MN frequencies (mean ± SD) in PHA‐stimulated blood cells of patients with vitiligo and control subjects were 0.94 ± 0.58 and 0.58 ± 0.32, respectively. Compared with control subjects, MN frequencies of patients with vitiligo were found significantly higher than those of the control subjects (P = 0.012).

Conclusion  Our results indicate unexpectedly some chromosomal/DNA damage in whole‐blood cultures of patients with vitiligo. We do not know, however, if these chromosome/DNA instabilities observed in the cells of vitiligo patients resulted from the cause or from the consequences of the disorder.
The European Surveillance System of Contact Allergies (ESSCA): results of patch testing the standard series, 2004
Authors:   The ESSCA Writing Group
Published: July 2007

Background  The European Surveillance System on Contact Allergies (ESSCA) began in 2001 as project funded by a European Union grant to monitor and evaluate contact sensitization (CS) based on clinical data collected by participating European dermatology departments.

Objectives  ESSCA aims to detect trends in CS in an international patch test population, monitoring the frequency of CS to (standard series) allergens, evaluating the effectiveness of intervention (e.g. governmental regulations) and improving standardization of the patch test procedure on an international level.

Methods  In 2004, 31 ESSCA dermatology departments in 11 European countries collected patch test results and medical histories of patients tested with the European Standard Series (ESS) or a local standard allergen series using the multilingual Winalldat/ESSCA database, the German Winalldat/Information Network of Departments of Dermatology (IVDK) database or a locally created database including the items of the ESSCA ‘minimal data set’. Data were sent to the ESSCA data centre where they were imported, pooled, examined for quality and subsequently analysed.

Results  The departments patch tested 11 643 patients with a standard series, and 44% of the patients tested positive to one or more substances of the ESS. Nickel sulphate, the fragrance mix, Myroxylon pereirae resin, cobalt chloride, potassium dichromate, methyldibromoglutaronitrile and paraphenylenediamine are (still) the most important allergens detected. Several additional substances tested on consecutive patients in some clinics were also examined. Among these allergens, propolis and Compositae mix had a relatively high CS prevalence.

Conclusions  The expanding ESSCA network continues to provide up‐to‐date information regarding the pattern of CS diagnosed in participating departments across Europe.
Effective treatment for dermatophytoses of the foot: effect on restoration of depressed cell‐mediated immunity
Authors: Schmid‐Wendtner M‐H , Korting HC
Published: July 2007

Superficial infections caused by dermatophyte fungi are highly prevalent throughout the world. Modern antimycotic agents like the azole itraconazole or the synthetic allylamine terbinafine greatly improved treatment outcomes in comparison with former therapeutic options with griseofulvin or older azole preparations like ketoconazole or fluconazole. In randomized trials involving patients with dermotophytoses, a great effectiveness has been shown especially for terbinafine. Oral terbinafine in general is well tolerated, has a low potential for drug interactions and, therefore, may be the most often used therapeutic agent for dermatophyte onychomycosis. However, there is a group of patients suffering from chronic dermatophytoses or early reinfections after antifungal therapy. For these patients, a depression of the delayed‐type hypersensitivity reactivity was postulated. Just recently, effective antimycotic treatment, in particular with terbinafine, was shown to enhance and restore cell‐mediated immunity, which potentially improves the therapeutic outcome even for this group of patients.
Artificial and natural ultraviolet radiation exposure: beliefs and behaviour of 7200 French adults
Authors: Ezzedine K , Malvy D , Mauger E , Nageotte O , Galan P , Hercberg S , Guinot C
Published: July 2007

Background  Despite the increasing use of indoor tanning facilities, little is known regarding the behaviour of adults with respect to artificial and natural ultraviolet (UV) radiation exposure and the relationship between the two forms of exposure.

Objectives  To describe the beliefs and behaviour of French middle‐aged volunteers regarding artificial and natural UV exposure.

Methods  Cross‐sectional study of a French national cohort using a self‐completed questionnaire.

Results  Participants were identified as ‘indoor UV tanners’ (n= 1076) and as ‘non‐users’ (n= 6124). Predictor factors associated with indoor tanning were gender, age, smoking, phototype, region of residence, sun exposure during hobbies, voluntary sun exposure in particular during the hottest hours of the day, nudism practice, facial sunscreen habits, sunglass use, importance for lying in the sun and the claim ‘ever heard of melanoma’.

Limitations  The quality of information may be limited by the data collection method.

Conclusion  Whereas indoor tanning should be discouraged, it seems that indoor tanners are also regular sunbathers unconcerned about the risk of photoageing and skin cancer occurrence. Moreover, indoor tanners seem to have more behavioural risk factors for cancer, such as smoking.
Contact sensitivity to preservatives in the UK, 2004–2005: results of multicentre study
Authors: Jong Cherng T. , Statham Barry N. , Green Cathy M. , King Codagh M. , Gawkrodger David J. , Sansom Jane E. , English John S. C. , Wilkinson S. Mark , Ormerod Anthony D. , Chowdhury Mahbub M. U.
Published: July 2007

Preservative sensitivity in the UK was last assessed in 2000. Given the changes in preservative usage, we have re‐evaluated our patch test data in order to detect any changes in the trend of sensitization. The results of patch testing using the extended British Contact Dermatitis Society Standard series were collected from 9 dermatology centres in the UK. Positive reactions to each of 10 preservative allergens were captured together with the MOAHFLA indices for each centre. In total, 6958 patients were tested during the period 2004–2005. The current data were compared with previously published data. Formaldehyde and methylchloroisothiazolinone/methyl‐isothiazolinone have the highest positivity rates at 2.0% and chloroxylenol the lowest at 0.2%. Parabens mix has the highest irritancy rate. Compared with the UK data in 2000, the positivity rate of imidazolidinyl urea (0.02 < P < 0.05) has significantly increased and that of methyldibromo glutaronitrile has significantly reduced (P < 0.001).
Dicaprylyl maleate – an emerging cosmetic allergen
Authors: Lotery Helen , Kirk Stephen , Beck Michael , Burova Ekaterina , Crone Mary , Curley Reginald , Downs Anthony , Hill Glenda , Horne Helen , Iftikhar Nadia , Lovell Christopher , Malanin Ken , Orton David , Powell Sheila , Sansom Jane , Sonnex Timothy , Todd David , Tucker Simon , Wilkinson Mark , Haworth Adam
Published: July 2007

Dicaprylyl maleate (DCM) has been reported rarely as a cause of allergic contact dermatitis. The objectives of this study were to identify patients from multiple centres with allergy to DCM in cosmetic products confirmed by patch testing and, in addition, to investigate the effect of testing with aged DCM. This is an international multicentre study of 22 patients with 26 reactions to products containing DCM. Patch testing was carried out to ingredients including DCM obtained from the manufacturer. Further testing was carried out with deliberately aged DCM in a sample of patients. 22 patients had clinical and positive patch test reactions at 4 days to a total of 26 cosmetic products containing DCM. 5 patients did not react to DCM prepared by the manufacturer from concurrent factory stock but did have positive reactions to a deliberately aged batch of DCM. DCM is an emerging cosmetic allergen. Testing with aged material yields a greater number of positive results. Co‐operation between cosmetics manufacturers and clinicians is important in the identification of new allergens.
Self‐reported skin symptoms in metal workers
Authors: Suuronen Katri , Jolanki Riita , Luukkonen Ritva , Alanko Kristiina , Susitaival Päivikki
Published: July 2007

Machinists and machine maintenance men working in the metal industry use metal‐working fluids capable of causing irritant and allergic contact dermatitis. The objectives of this study were to find out the frequency of skin symptoms in machinists and machine maintenance men (metal workers) and to compare the risk of their skin symptoms to that in office workers (controls). A total of 726 male metal workers and 84 controls answered a structured telephone questionnaire enquiring about work, atopy, skin symptoms, their impact on life, etc. The risk of skin symptoms compared with that in the controls was estimated using a logistic regression analysis. Of the metal workers, 20% reported recurring or prolonged dermatitis on their hands or forearms during the past 12 months. The hand or forearm dermatitis (HD) affected mostly the metal workers’ mood and their activities at work. Recurring dermatitis elsewhere (DE) than in the hands and in connection with work was reported by 10%. The risk of HD was about twofold and the risk of DE was about fourfold compared with that in the controls. The HD of machinists may be severe and affect their ability to work. DE may have clinical significance in machinists.
Mechanism of Two Classes of Cancer Mutations in the Phosphoinositide 3-Kinase Catalytic Subunit
Authors: Miled Nabil , Yan Ying , Hon Wai-Ching , Perisic Olga , Zvelebil Marketa , Inbar Yuval , Schneidman-Duhovny Dina , Wolfson Haim J. , Backer Jonathan M. , Williams Roger L.
Published: July 2007

Many human cancers involve up-regulation of the phosphoinositide 3-kinase PI3Kα, with oncogenic mutations identified in both the p110α catalytic and the p85α regulatory subunits. We used crystallographic and biochemical approaches to gain insight into activating mutations in two noncatalytic p110α domains—the adaptor-binding and the helical domains. A structure of the adaptor-binding domain of p110α in a complex with the p85α inter–Src homology 2 (inter-SH2) domain shows that oncogenic mutations in the adaptor-binding domain are not at the inter-SH2 interface but in a polar surface patch that is a plausible docking site for other domains in the holo p110/p85 complex. We also examined helical domain mutations and found that the Glu
545
to Lys
545
(E545K) oncogenic mutant disrupts an inhibitory charge-charge interaction with the p85 N-terminal SH2 domain. These studies extend our understanding of the architecture of PI3Ks and provide insight into how two classes of mutations that cause a gain in function can lead to cancer.
Combinatorial ShcA Docking Interactions Support Diversity in Tissue Morphogenesis
Authors: Hardy W. Rod , Li Lingying , Wang Zhi , Sedy Jiri , Fawcett James , Frank Eric , Kucera Jan , Pawson Tony
Published: July 2007

Changes in protein-protein interactions may allow polypeptides to perform unexpected regulatory functions. Mammalian ShcA docking proteins have amino-terminal phosphotyrosine (pTyr) binding (PTB) and carboxyl-terminal Src homology 2 (SH2) domains, which recognize specific pTyr sites on activated receptors, and a central region with two phosphorylated tyrosine-X-asparagine (pYXN) motifs (where X represents any amino acid) that each bind the growth factor receptor–bound protein 2 (Grb2) adaptor. Phylogenetic analysis indicates that ShcA may signal through both pYXN-dependent and -independent pathways. We show that, in mice, cardiomyocyte-expressed ShcA directs mid-gestational heart development by a PTB-dependent mechanism that does not require the pYXN motifs. In contrast, the pYXN motifs are required with PTB and SH2 domains in the same ShcA molecule for the formation of muscle spindles, skeletal muscle sensory organs that regulate motor behavior. Thus, combinatorial differences in ShcA docking interactions may yield multiple signaling mechanisms to support diversity in tissue morphogenesis.
Comment on "Maternal Oxytocin Triggers a Transient Inhibitory Switch in GABA Signaling in the Fetal Brain During Delivery"
Authors: Carbillon Lionel
Published: July 2007

Tyzio
et al
. (Reports, 15 December 2006, p. 1788) reported that maternal oxytocin triggers a transient excitatory-to-inhibitory switch of γ-aminobutyric acid (GABA) signaling during labor, thus protecting the fetal rat brain from anoxic injury. However, a body of evidence supports the possibility that oxytocin is released from the fetal pituitary during delivery, not only from the mother, particularly under conditions of hypoxic stress.
Methicillin-Resistant
Staphylococcus aureus
Infection or Colonization Present at Hospital Admission: Multivariable Risk Factor Screening To Increase Efficiency of Surveillance Culturing
Authors: Haley Clinton C. , Mittal Deepa , LaViolette Amanda , Jannapureddy Sai , Parvez Najma , Haley Robert W.
Published: July 2007

Identifying methicillin-resistant
Staphylococcus aureus
(MRSA) colonization or infection present at admission has become important in reducing subsequent nosocomial transmission, but the most efficient surveillance methods remain to be defined. We performed anterior nares surveillance cultures of all patients upon admission to and discharge from the general internal medicine floor in our community hospital over a 7-week period, and patients completed a questionnaire on MRSA risk factors. Of the 401 patients, 41 (10.2%) had MRSA upon admission. Of the 48 risk measures analyzed, 10 were significantly associated with admission MRSA, and 7 of these were independently associated in stepwise logistic regression analysis. Factor analysis identified eight latent variables that contained most of the predictive information in the 48 risk measures. Repeat logistic regression analysis including the latent variables revealed three independent risk measures for admission MRSA: a nursing home stay (relative risk [RR], 6.18; 95% confidence interval [95% CI], 3.56 to 10.72;
P
< 0.0001), prior MRSA infection (RR, 3.97; 95% CI, 1.94 to 8.12;
P
= 0.0002), and the third latent variable (factor 3; RR, 3.14; 95% CI, 1.56 to 6.31;
P
= 0.0013), representing the combined effects of homelessness, jail stay, promiscuity, intravenous drug use, and other drug use. Multivariable models had greater sensitivity at detecting admission MRSA than any single risk measure and allowed detection of 78% to 90% of admission MRSA from admission surveillance cultures on 46% to 58% of admissions. If confirmed in additional studies, multivariable questionnaire screening at admission might identify a subset of admissions for surveillance cultures that would more efficiently identify most admission MRSA.
Detection of Fifteen Species of
Candida
in an Automated Blood Culture System
Authors: Horvath Lynn L. , George Benjamin J. , Hospenthal Duane R.
Published: July 2007

Candidemia was simulated with 15
Candida
spp. by using an automated blood culture system.
Candida
growth was detected in 479/648 (74%) bottles: 211/216 (98%) aerobic bottles, 58/216 (27%) anaerobic bottles, and 210/216 (97%) mycology bottles. Only the growth of
Candida lipolytica
failed to be detected in all media.
Hantavirus Disease Outbreak in Germany: Limitations of Routine Serological Diagnostics and Clustering of Virus Sequences of Human and Rodent Origin
Authors: Schilling Stefan , Emmerich Petra , Klempa Boris , Auste Brita , Schnaith Ebbo , Schmitz Herbert , Krüger Detlev H. , Günther Stephan , Meisel Helga
Published: July 2007

In Europe, hemorrhagic fever with renal syndrome results mainly from infection with Puumala virus (PUUV) or Dobrava virus. For 31 patients from a hantavirus disease outbreak in Lower Bavaria, a district in southeast Germany, serodiagnosis was undertaken by enzyme-linked immunosorbent assay, immunofluorescence assay, and immunoblot analysis. In a few of these cases, however, PUUV-specific typing of antibodies by these standard assays failed and a virus neutralization assay under biosafety level 3 conditions was required to verify the infection by this virus type. PUUV RNA was amplified by reverse transcription-PCR from acute-phase sera of three patients and was found to be very closely related to virus sequences obtained from bank voles (
Clethrionomys glareolus
) trapped in the same area. These findings link the outbreak with a novel PUUV lineage, “Bavaria,” circulating in the local rodent population. The Bavaria lineage associated with the outbreak is only distantly related to other PUUV lineages from Germany.
Differential Functional Avidity of Dengue Virus-Specific T-Cell Clones for Variant Peptides Representing Heterologous and Previously Encountered Serotypes
Authors: Imrie Allison , Meeks Janet , Gurary Alexandra , Sukhbataar Munkhzul , Kitsutani Paul , Effler Paul , Zhao Zhengshan
Published: July 2007

Proinflammatory cytokines secreted by memory CD8+and CD4+T cells are thought to play a direct role in the pathogenesis of dengue virus infection by increasing vascular permeability and thereby inducing the pathophysiologic events associated with dengue hemorrhagic fever and dengue shock syndrome. Severe disease is frequently observed in the setting of secondary infection with heterologous dengue virus serotypes, suggesting a role for cross-reactive memory T cells in the immunopathogenesis of severe disease. We used a large panel of well-characterized dengue virus-specific CD8+T-cell clones isolated from Pacific Islanders previously infected with dengue virus 1 to examine effector memory function, focusing on a novel dominant HLA-B*5502-restricted NS5329-337epitope, and assessed T-cell responses to stimulation with variant peptides representing heterologous serotypes. Variant peptides were differentially recognized by dengue virus 1-specific effector CD8+cytotoxic T lymphocytes (CTL) in a heterogeneous and clone-specific manner, in which cytolytic function and cytokine secretion could be enhanced, diminished, or abrogated compared with cognate peptide stimulation. Dengue virus-specific CTL stimulated with cognate and variant peptides demonstrated a cytokine response hierarchy of gamma IFN (IFN-γ) > tumor necrosis factor alpha (TNF-α) > interleukin-2 (IL-2), and a subset of clones also produced IL-4 and IL-6. Individual clones demonstrated greater avidity for variant peptides representing heterologous serotypes, including serotypes previously encountered by the subject, and IFN-γ and TNF-α secretion was enhanced by stimulation with these heterologous peptides. Altered antiviral T-cell responses in response to stimulation with heterologous dengue virus serotypes have implications for control of virus replication and for disease pathogenesis.
Type I Interferon Inhibition and Dendritic Cell Activation during Gammaherpesvirus Respiratory Infection
Authors: Weslow-Schmidt Janet L. , Jewell Nancy A. , Mertz Sara E. , Simas J. Pedro , Durbin Joan E. , Flaño Emilio
Published: July 2007

The respiratory tract is a major mucosal site for microorganism entry into the body, and type I interferon (IFN) and dendritic cells constitute a first line of defense against viral infections. We have analyzed the interaction between a model DNA virus, plasmacytoid dendritic cells, and type I IFN during lung infection of mice. Our data show that murine gammaherpesvirus 68 (γHV68) inhibits type I IFN secretion by dendritic cells and that plasmacytoid dendritic cells are necessary for conventional dendritic cell maturation in response to γHV68. Following γHV68 intranasal inoculation, the local and systemic IFN-α/β response is below detectable levels, and plasmacytoid dendritic cells are activated and recruited into the lung with a tissue distribution that differs from that of conventional dendritic cells. Our results suggest that plasmacytoid dendritic cells and type I IFN have important but independent roles during the early response to a respiratory γHV68 infection. γHV68 infection inhibits type I IFN production by dendritic cells and is a poor inducer of IFN-α/β in vivo, which may serve as an immune evasion strategy.
Brd4-Independent Transcriptional Repression Function of the Papillomavirus E2 Proteins
Authors: Schweiger Michal-Ruth , Ottinger Matthias , You Jianxin , Howley Peter M.
Published: July 2007

The papillomavirus E2 protein is a critical viral regulatory protein with transcription, DNA replication, and genome maintenance functions. We have previously identified the cellular bromodomain protein Brd4 as a major E2-interacting protein and established that it participates in tethering bovine papillomavirus type 1 E2 and viral genomes to host cell mitotic chromosomes. We have also shown that Brd4 mediates E2-dependent transcriptional activation, which is strongly inhibited by the disruption of E2/Brd4 binding as well as by short hairpin RNA (shRNA) knockdown of Brd4 expression levels. Since several mutants harboring single amino acid substitutions within the E2 transactivation domain that are defective for both transcriptional transactivation and Brd4 binding are also defective for transcriptional repression, we examined the role of Brd4 in E2 repression of the human papillomavirus E6/E7 promoter. Surprisingly, in a variety of in vivo assays, including transcription reporter assays, HeLa cell proliferation and colony reduction assays, and Northern blot analyses, neither blocking of the binding of E2 to Brd4 nor shRNA knockdown of Brd4 affected the E2 repression function. Our study provides evidence for a Brd4-independent mechanism of E2-mediated repression and suggests that different cellular factors must be involved in E2-mediated transcriptional activation and repression functions.
An Avian Influenza H5N1 Virus That Binds to a Human-Type Receptor
Authors: Auewarakul Prasert , Suptawiwat Ornpreya , Kongchanagul Alita , Sangma Chak , Suzuki Yasuo , Ungchusak Kumnuan , Louisirirotchanakul Suda , Lerdsamran Hatairat , Pooruk Phisanu , Thitithanyanont Arunee , Pittayawonganon Chakrarat , Guo Chao-Tan , Hiramatsu Hiroaki , Jampangern Wipawee , Chunsutthiwat Supamit , Puthavathana Pilaipan
Published: July 2007

Avian influenza viruses preferentially recognize sialosugar chains terminating in sialic acid-α2,3-galactose (SAα2,3Gal), whereas human influenza viruses preferentially recognize SAα2,6Gal. A conversion to SAα2,6Gal specificity is believed to be one of the changes required for the introduction of new hemagglutinin (HA) subtypes to the human population, which can lead to pandemics. Avian influenza H5N1 virus is a major threat for the emergence of a pandemic virus. As of 12 June 2007, the virus has been reported in 45 countries, and 312 human cases with 190 deaths have been confirmed. We describe here substitutions at position 129 and 134 identified in a virus isolated from a fatal human case that could change the receptor-binding preference of HA of H5N1 virus from SAα2,3Gal to both SAα2,3Gal and SAα2,6Gal. Molecular modeling demonstrated that the mutation may stabilize SAα2,6Gal in its optimal
cis
conformation in the binding pocket. The mutation was found in approximately half of the viral sequences directly amplified from a respiratory specimen of the patient. Our data confirm the presence of H5N1 virus with the ability to bind to a human-type receptor in this patient and suggest the selection and expansion of the mutant with human-type receptor specificity in the human host environment.
Interaction between the Cellular Protein eEF1A and the 3′-Terminal Stem-Loop of West Nile Virus Genomic RNA Facilitates Viral Minus-Strand RNA Synthesis
Authors: Davis William G. , Blackwell Jerry L. , Shi Pei-Yong , Brinton Margo A.
Published: July 2007

RNase footprinting and nitrocellulose filter binding assays were previously used to map one major and two minor binding sites for the cell protein eEF1A on the 3′(+) stem-loop (SL) RNA of West Nile virus (WNV) (3). Base substitutions in the major eEF1A binding site or adjacent areas of the 3′(+) SL were engineered into a WNV infectious clone. Mutations that decreased, as well as ones that increased, eEF1A binding in in vitro assays had a negative effect on viral growth. None of these mutations affected the efficiency of translation of the viral polyprotein from the genomic RNA, but all of the mutations that decreased in vitro eEF1A binding to the 3′ SL RNA also decreased viral minus-strand RNA synthesis in transfected cells. Also, a mutation that increased the efficiency of eEF1A binding to the 3′ SL RNA increased minus-strand RNA synthesis in transfected cells, which resulted in decreased synthesis of genomic RNA. These results strongly suggest that the interaction between eEF1A and the WNV 3′ SL facilitates viral minus-strand synthesis. eEF1A colocalized with viral replication complexes (RC) in infected cells and antibody to eEF1A coimmunoprecipitated viral RC proteins, suggesting that eEF1A facilitates an interaction between the 3′ end of the genome and the RC. eEF1A bound with similar efficiencies to the 3′-terminal SL RNAs of four divergent flaviviruses, including a tick-borne flavivirus, and colocalized with dengue virus RC in infected cells. These results suggest that eEF1A plays a similar role in RNA replication for all flaviviruses.
cis
Effects in Adeno-Associated Virus Type 2 Replication
Authors: Ward Peter , Clément Nathalie , Linden R. Michael
Published: July 2007

We have utilized deletion mutants of adeno-associated virus (AAV) to investigate which elements of the AAV genome are required in
cis
for high yields of the wild-type virus in a plasmid transfection assay and in addition whether these elements affect primarily AAV DNA replication or encapsidation. All tested deletions from within the Rep region demonstrated a modest, approximately threefold, decrease in viral production. Deletions within the
cap
region resulted in markedly less virus. Previous observations suggested that in cells in which recombinant AAV (rAAV) was produced, as in our assay with the helper plasmid pDG, there is a substantial excess of empty capsids. Cotransfections of high- and low-yielding constructs demonstrated that under conditions where Cap is abundant, the constructs with
cap
deletions did not package efficiently. These observation suggest that the lower yields of rAAV cannot be entirely due to lack of capsids but that elements within the
cap
region of the wild-type genome are important for efficient encapsidation. The production of virus by the mutants we tested was, however, not consistent with the disruption of a
cis
-acting packaging signal. Apparently, when Cap is provided “in
trans
,” encapsidation is inefficient. A second observation is that there were equivalent amounts of replicated but unencapsidated viral DNA in cells transfected with each of our constructs. We propose that, in accord with the previously proposed link between DNA replication and encapsidation, the total amount of AAV DNA replication can be limited by the efficiency of encapsidation.
Role of Endocytosis and Low pH in Murine Hepatitis Virus Strain A59 Cell Entry
Authors: Eifart Patricia , Ludwig Kai , Böttcher Christoph , de Haan Cornelis A. M. , Rottier Peter J. M. , Korte Thomas , Herrmann Andreas
Published: July 2007

Infection by the coronavirus mouse hepatitis virus strain A59 (MHV-A59) requires the release of the viral genome by fusion with the respective target membrane of the host cell. Fusion is mediated by the viral S protein. Here, the entry pathway of MHV-A59 into murine fibroblast cells was studied by independent approaches. Infection of cells assessed by plaque reduction assay was strongly inhibited by lysosomotropic compounds and substances that interfere with clathrin-dependent endocytosis, suggesting that MHV-A59 is taken up via endocytosis and delivered to acidic endosomal compartments. Infection was only slightly reduced in the presence of substances inhibiting proteases of endosomal compartments, precluding that the endocytic uptake is required to activate the fusion potential of the S protein by its cleavage. Fluorescence confocal microscopy of labeled MHV-A59 confirmed that virus is taken up via endocytosis. Bright labeling of intracellular compartments suggests their fusion with the viral envelope. No fusion with the plasma membrane was observed at neutral pH conditions. However, when virus was bound to cells and the pH was lowered to 5.0, we observed a strong labeling of the plasma membrane. Electron microscopy revealed low pH triggered conformational alterations of the S ectodomain. Very likely, these alterations are irreversible because low-pH treatment of viruses in the absence of target membranes caused an irreversible loss of the fusion activity. The results imply that endocytosis plays a major role in MHV-A59 infection and the acidic pH of the endosomal compartment triggers a conformational change of the S protein mediating fusion.
Preferential Integration of Adeno-Associated Virus Type 2 into a Polypyrimidine/Polypurine-Rich Region within
AAVS1
Authors: McAlister Victor J. , Owens Roland A.
Published: July 2007

Adeno-associated virus type 2 (AAV2) preferentially integrates its genome into the
AAVS1
locus on human chromosome 19. Preferential integration requires the AAV2 Rep68 or Rep78 protein (Rep68/78), a Rep68/78 binding site (RBS), and a nicking site within
AAVS1
and may also require an RBS within the virus genome. To obtain further information that might help to elucidate the mechanism and preferred substrate configurations of preferential integration, we amplified junctions between AAV2 DNA and
AAVS1
from AAV2-infected HeLaJW cells and cells with defective Artemis or xeroderma pigmentosum group A genes. We sequenced 61 distinct junctions. The integration junction sequences show the three classical types of nonhomologous-end-joining joints: microhomology at junctions (57%), insertion of sequences that are not normally contiguous with either the AAV2 or the
AAVS1
sequences at the junction (31%), and direct joining (11%). These junctions were spread over 750 bases and were all downstream of the Rep68/78 nicking site within
AAVS1.
Two-thirds of the junctions map to 350 bases of
AAVS1
that are rich in polypyrimidine tracts on the nicked strand. The majority of AAV2 breakpoints were within the inverted terminal repeat (ITR) sequences, which contain RBSs. We never detected a complete ITR at a junction. Residual ITRs at junctions never contained more than one RBS, suggesting that the hairpin form, rather than the linear ITR, is the more frequent integration substrate. Our data are consistent with a model in which a cellular protein other than Artemis cleaves AAV2 hairpins to produce free ends for integration.
Minute Virus of Mice, a Parvovirus, in Complex with the Fab Fragment of a Neutralizing Monoclonal Antibody
Authors: Kaufmann Bärbel , López-Bueno Alberto , Mateu Mauricio G. , Chipman Paul R. , Nelson Christian D. S. , Parrish Colin R. , Almendral José M. , Rossmann Michael G.
Published: July 2007

The structure of virus-like particles of the lymphotropic, immunosuppressive strain of minute virus of mice (MVMi) in complex with the neutralizing Fab fragment of the mouse monoclonal antibody (MAb) B7 was determined by cryo-electron microscopy to 7-Å resolution. The Fab molecule recognizes a conformational epitope at the vertex of a three-fold protrusion on the viral surface, thereby simultaneously engaging three symmetry-related viral proteins in binding. The location of the epitope close to the three-fold axis is consistent with the previous analysis of MVMi mutants able to escape from the B7 antibody. The binding site close to the symmetry axes sterically forbids the binding of more than one Fab molecule per spike. MAb as well as the Fab molecules inhibits the binding of the minute virus of mice (MVM) to permissive cells but can also neutralize MVM postattachment. This finding suggests that the interaction of B7 with three symmetry-related viral subunits at each spike hinders structural transitions in the viral capsid essential during viral entry.
Fatal Neurological Disease in Scrapie-Infected Mice Induced for Experimental Autoimmune Encephalomyelitis
Authors: Friedman-Levi Yael , Ovadia Haim , Hoftberger Romana , Einstein Ofira , Abramsky Oded , Budka Herbert , Gabizon Ruth
Published: July 2007

During the years or decades of prion disease incubation, at-risk individuals are certain to encounter diverse pathological insults, such as viral and bacterial infections, autoimmune diseases, or inflammatory processes. Whether prion disease incubation time and clinical signs or otherwise the pathology of intercurrent diseases can be affected by the coinfection process is unknown. To investigate this possibility, mice infected with the scrapie agent at both high and low titers were subsequently induced for experimental autoimmune encephalomyelitis, an immune system-mediated model of central nervous system (CNS) inflammation. We show here that coinduced mice died from a progressive neurological disease long before control mice succumbed to classical scrapie. To investigate the mechanism of the coinduced syndrome, we evaluated biochemical and pathological markers of both diseases. Brain and spleen PrP
Sc
levels in the dying coinduced mice were comparable to those observed in asymptomatic scrapie-infected animals, suggesting that coinduced disease is not an accelerated form of scrapie. In contrast, inflammatory markers, such as demyelination, immune cell infiltrates, and gliosis, were markedly increased in coinduced mouse spinal cords. Activated astrocytes were especially elevated in the medulla oblongata. Furthermore, PrP
sc
depositions were found in demyelinated white matter areas in coinduced mouse spinal cords, suggesting the presence of activated infected immune cells that infiltrate into the CNS to facilitate the process of prion neuroinvasion. We hypothesize that inflammatory processes affecting the CNS may have severe clinical implications in subjects incubating prion diseases.
Polyomavirus Small T Antigen Controls Viral Chromatin Modifications through Effects on Kinetics of Virus Growth and Cell Cycle Progression
Authors: Dahl Jean , Chen H. Isaac , George Michael , Benjamin Thomas L.
Published: July 2007

Minichromosomes of wild-type polyomavirus were previously shown to be highly acetylated on histones H3 and H4 compared either to bulk cell chromatin or to viral chromatin of nontransforminghr-tmutants, which are defective in both the small T and middle T antigens. A series of site-directed virus mutants have been used along with antibodies to sites of histone modifications to further investigate the state of viral chromatin and its dependence on the T antigens. Small T but not middle T was important in hyperacetylation at major sites in H3 and H4. Mutants blocked in middle T signaling pathways but encoding normal small T showed a hyperacetylated pattern similar to that of wild-type virus. The hyperacetylation defect ofhr-tmutant NG59 was partially complemented by growth of the mutant in cells expressing wild-type small T. In contrast to the hypoacetylated state of NG59, NG59 minichromosomes were hypermethylated at specific lysines in H3 and also showed a higher level of phosphorylation at H3ser10, a modification associated with the late G2and M phases of the cell cycle. Comparisons of virus growth kinetics and cell cycle progression in wild-type- and NG59-infected cells showed a correlation between the phase of the cell cycle at which virus assembly occurred and histone modifications in the progeny virus. Replication and assembly of wild-type virus were completed largely during S phase. Growth of NG59 was delayed by about 12 h with assembly occurring predominately in G2. These results suggest that small T affects modifications of viral chromatin by altering the temporal coordination of virus growth and the cell cycle.
Even Attenuated Bovine Leukemia Virus Proviruses Can Be Pathogenic in Sheep
Authors: Florins Arnaud , Gillet Nicolas , Boxus Mathieu , Kerkhofs Pierre , Kettmann Richard , Willems Luc
Published: July 2007

Based on a reverse genetics approach, we previously reported that bovine leukemia virus (BLV) mutants harboring deletions in the accessory R3 and G4 genes persist at very low proviral loads and are unable to induce leukemia or lymphoma in sheep, indicating that these R3 and G4 gene sequences are required for pathogenesis. We now show that lymphoma can occur, albeit infrequently (1 case of 20) and after extended periods of latency (7 years). Direct sequencing and reinfection experiments demonstrated that lymphomagenesis was not due to the reversion of the mutant to the wild type. Similar observations with another type of attenuated mutant impaired in the transmembrane protein (TM) YXXL signaling motifs were made. We conclude that the R3 and G4 genes and the TM YXXL motifs are not strictly required for pathogenesis but that their integrity contributes to disease frequency and latency.
Bortezomib Induces Apoptosis of Epstein-Barr Virus (EBV)-Transformed B Cells and Prolongs Survival of Mice Inoculated with EBV-Transformed B Cells
Authors: Zou Ping , Kawada Junichi , Pesnicak Lesley , Cohen Jeffrey I.
Published: July 2007

Bortezomib, an inhibitor of the 26S proteasome, is currently approved for treatment of multiple myeloma and is being studied for therapy of non-Hodgkin's lymphoma. We found that Epstein-Barr virus (EBV)-positive B cells with type III latency were more susceptible to killing by bortezomib than those with type I latency. Bortezomib induced apoptosis of EBV lymphoblastoid cell lines (LCLs) by inducing cleavage of caspases 8 and 9; apoptosis was inhibited by pretreatment with a pan-caspase inhibitor. Bortezomib reduced the levels of the p50 and p65 components of the canonical NF-κB pathway and reduced the level of p52 in the noncanonical NF-κB pathway, which is induced by EBV LMP1. Bortezomib inhibited expression of cIAP-1, cIAP-2, and XIAP, which are regulated by NF-κB and function as inhibitors of apoptosis. Bortezomib did not inhibit expression of several other antiapoptotic proteins, including Bcl-2 and Bcl-XL. Finally, bortezomib significantly prolonged the survival of severe combined immunodeficiency mice inoculated with LCLs. These findings suggest that bortezomib may represent a novel strategy for the treatment of certain EBV-associated lymphomas.
Echocardiographic assessment of blood flow volume in the superior vena cava and descending aorta in the newborn infant
Authors: Groves A M , Kuschel C A , Knight D B , Skinner J R
Published: July 2007

Background:

Clinical methods of assessing adequacy of the circulation are poor predictors of volume of blood flow in the newborn preterm. Doppler echocardiography can be used to assess perfusion at various sites in the circulation.

Objective:

To assess repeatability of measurement of volume of superior vena caval (SVC) and descending aortic (DAo) flow.

Design:

SVC and DAo flow volume were assessed four times in the first 48 h of postnatal life in a cohort of preterm (<31 weeks) infants. Within-observer and between-observer repeatability was assessed in a subgroup of preterm infants. Normative values were derived from 14 preterm infants who required <48 h respiratory support and 13 healthy term infants.

Results:

Within-observer repeatability coefficient was 30 ml/kg/min for quantification of SVC flow, and 2.2 cm for DAo stroke distance. Measurement of DAo diameter had poor repeatability. Between-observer repeatability appeared poorer than within-observer repeatability. The fifth centile for volume of SVC flow in healthy preterm infants was 55 ml/kg/min and 4.5 cm for DAo stroke distance.

Conclusions:

Echocardiographic assessments of volume of SVC flow and velocity of DAo flow have similar within-observer repeatability to other neonatal haemodynamic measurements. Between-observer repeatability for both measurements was poor, reflecting the difficulty of standardising these novel techniques. In this small cohort of preterm infants, SVC flow volume <55 ml/kg/min and DAo stroke distance <4.5 cm represented low or borderline systemic perfusion in the first 48 h of postnatal life.
Using administrative sickness absence data as a marker of future disability pension: the prospective DREAM study of Danish private sector employees
Authors: Lund Thomas , Kivimäki Mika , Labriola Merete , Villadsen Ebbe , Christensen Karl Bang
Published: July 2007

Objectives:

The aim of this study was to examine duration of sickness absence as a risk marker for future disability pension among all private sector employees in Denmark 1998–2004.

Methods:

All private sector employees receiving sickness absence compensation from the municipality in 1998, a total of 225 056 persons (39.2% women 61.8% men, age range 18–65, mean age 37.2), were followed in a national register to determine granted disability pension during the period 1 January 2001 through 31 December 2004. The authors excluded pensions in 1999 and 2000 to determine the status of sickness absence duration as an early risk marker.

Results:

5694 persons (2.5%) received disability pension during follow-up, more men (53.4%) than women (46.6%). There was a strong graded association between increasing length of absence and increasing risk of future disability pension. Significant differences were found between the younger and older age strata: men below 40 experiencing more than 26 weeks of sickness absence had a 16-fold risk of disability pension. The corresponding figure for men 40 years or older was approximately 7. For women, the corresponding figures were 12.6 and 6.7 respectively.

Conclusion:

The findings suggest that administratively collected data on sickness absence compensation are an important predictor of disability pension among private sector employees. The use of information on sick leave may improve the effectiveness of early interventions by policy makers, case managing authorities, employers and physicians.