bluuebunny/crossref_metadata_2025_split huggingface dataset:
Use of Antigens Derived from
Burkholderia pseudomallei
,
B. thailandensis
, and
B. cepacia
in the Indirect Hemagglutination Assay for Melioidosis
Authors: Gilmore Glenda , Barnes Jodie , Ketheesan Natkunam , Norton Robert 
Published: September 2007

ABSTRACT

The serological diagnosis of melioidosis is carried out using the indirect hemagglutination assay. We looked at the reactivity of sera from culture-proven cases of melioidosis from north Queensland against antigens derived from
Burkholderia pseudomallei
,
B. thailandensis
, and
B. cepacia
. Cross-reactivity between sera from culture-positive cases of melioidosis and
B. thailandensis
was demonstrated.
Tracing Shigatoxigenic
Escherichia coli
O103, O145, and O174 Infections from Farm Residents to Cattle
Authors: Heinikainen Sirpa , Pohjanvirta Tarja , Eklund Marjut , Siitonen Anja , Pelkonen Sinikka 
Published: September 2007

ABSTRACT

Severe diarrheal infections caused by Shigatoxigenic
Escherichia coli
O103:H2:
stx
1
:
eae
-ε:
ehx
, O145:H28:
stx
1
:
eae
-γ:
ehx
(two cases in a family), and O174:H21:
stx
2c
in farm residents were traced to cattle. Molecular methods were applied to the isolation and characterization of the strains. The causative strains were also isolated from cattle samples 1 or 4 months later.
Correlation between Infections with Different Genotypes of Human Cytomegalovirus and Epstein-Barr Virus in Subgingival Samples and Periodontal Status of Patients
Authors: Wu Yan-Min , Yan Jie , Ojcius David M. , Chen Li-Li , Gu Zhi-Yuan , Pan Jian-Ping 
Published: September 2007

ABSTRACTAccumulating evidence indicates that herpesviruses may be putative pathogens in various types of periodontal diseases. The present study was performed to examine infections with different genotypes of human cytomegalovirus (HCMV) and Epstein-Barr virus (EBV) in subgingival samples from a Chinese population and to analyze the correlation with periodontal status. A nested PCR assay was used to identify the presence of HCMV, EBV type 1 (EBV-1), and EBV-2; and the amplicons were further analyzed by restriction fragment length polymorphism analysis. HCMV was detected in 79.0% of 143 chronic periodontitis (CP) patients, 78.5% of 65 gingivitis patients, and 76.3% of 76 periodontally healthy individuals, while EBV was found in 63.6%, 32.3%, and 30.3% of the three groups of subjects, respectively. The HCMV-positive PCR products from all the samples were identified as corresponding to gB genotype I (gB-I) or gB-II. HCMV gB-II (62.9%), EBV-1 (43.4%), and EBV-2 (18.2%) were associated with CP at higher frequencies (P< 0.05), whereas HCMV gB-I was more often observed in gingivitis patients (40.0%) and healthy individuals (40.8%) (P< 0.05). Furthermore, a higher rate of coinfection with HCMV and EBV was shown in CP patients (52.4%), especially dual infections with HCMV gB-II and EBV-1 (30.8%) or HCMV gB-II and EBV-2 (12.6%), compared with the rates of single infections with HCMV or EBV (P< 0.05). Infection with HCMV gB-II, EBV-1, or EBV-2 was correlated with higher rates of bleeding on probing (P< 0.05). In patients infected with HCMV gB-II or both HCMV and EBV, including HCMV gB-II and EBV-1, a deeper probing depth or more serious attachment loss was found (P< 0.05). These findings clearly indicate that HCMV gB-II is the dominant genotype detected in subgingival samples in CP. HCMV gB-II infection and HCMV gB-II coinfection with EBV-1 are closely associated with periodontal tissue inflammation and destruction.
Comparison of Plaque- and Flow Cytometry-Based Methods for Measuring Dengue Virus Neutralization
Authors: Kraus Annette A. , Messer William , Haymore Laura B. , de Silva Aravinda M. 
Published: September 2007

ABSTRACTAs dengue vaccines enter clinical trials, there is a need for rapid and quantitative assays to measure neutralization. We have developed flow-based neutralization assays which generated results similar to those generated by the established, plaque reduction neutralization test. The flow assays are an improvement, as they use human cells and allow for high-throughput screening.
Rapid Microarray-Based Method for Monitoring of All Currently Known Single-Nucleotide Polymorphisms Associated with Parasite Resistance to Antimalaria Drugs
Authors: Crameri Andreas , Marfurt Jutta , Mugittu Kefas , Maire Nicolas , Regös Attila , Coppee Jean Yves , Sismeiro Odile , Burki Richard , Huber Eric , Laubscher Daniel , Puijalon Odile , Genton Blaise , Felger Ingrid , Beck Hans-Peter 
Published: September 2007

ABSTRACT

Parasite drug resistance is partly conferred by single-nucleotide polymorphisms (SNPs), and monitoring them has been proposed as an alternative to monitoring drug resistance. Therefore, techniques are required to facilitate analyses of multiple SNPs on an epidemiological scale. We report a rapid and affordable microarray technique for application in epidemiological studies of malaria drug resistance. We have designed a multiwell microarray that is used in conjunction with PCR-amplified target genes implicated in the drug resistance of malaria with subsequent one-tube minisequencing using two fluorochromes. The drug-resistance-associated genes
pfdhfr, pfdhps, pfcrt, pfmdr1
, and
pfATPase
were amplified and analyzed for cultured
Plasmodium falciparum
strains and from field samples. We obtained a specificity of 94%, and comparison of field sample results to those of restriction fragment length polymorphism (RFLP) typing resulted in an overall consistency of >90%, except for
pfdhfr51
, for which most discrepancies were due to false determinations by RFLP of mixed infections. The system is sufficiently sensitive to assay parasites in clinical malaria cases and in most asymptomatic cases, and it allows high throughput with minimal hands-on time. The cost for the assay has been calculated as 0.27 euros/SNP (US$0.33), which is below the cost incurred with other systems. Due to the simplicity of the approach, newly identified SNPs can be incorporated rapidly. Such a monitoring system also makes it possible to identify the reemergence of drug-susceptible parasites once a drug has been withdrawn.
Assessment of Population Structure and Major Circulating Phylogeographical Clades of
Mycobacterium tuberculosis
Complex in Bangladesh Suggests a High Prevalence of a Specific Subclade of Ancient
M. tuberculosis
Genotypes
Authors: Rahim Zeaur , Zaman Khadiza , van der Zanden Adri G. M. , Möllers Marius J. , van Soolingen Dick , Raqib Rubhana , Zaman Khalequ , Begum Vikarunessa , Rigouts Leen , Portaels Françoise , Rastogi Nalin , Sola Christophe 
Published: September 2007

ABSTRACT

Spoligotyping was performed to study the population structure of
Mycobacterium tuberculosis
complex strains (
n
= 224) from Bangladesh. Strains were split into principal genetic group 1 (PGG 1 [75.0%]) and PGG 2 and 3 (25%). Forty-nine strains with a new spoligotype signature and considered as south or southeast Asian-linked emerging clones were designated as “Matlab type.”
Differential Inhibition of Type I Interferon Induction by Arenavirus Nucleoproteins
Authors: Martínez-Sobrido Luis , Giannakas Panagiotis , Cubitt Beatrice , García-Sastre Adolfo , de la Torre Juan Carlos 
Published: September 2007

ABSTRACTWe have documented that the nucleoprotein (NP) of the prototypic arenavirus lymphocytic choriomeningitis virus is an antagonist of the type I interferon response. In this study we tested the ability of NPs encoded by representative arenavirus species from both Old World and New World antigenic groups to inhibit production of interferon. We found that, with the exception of Tacaribe virus (TCRV), all NPs tested inhibited activation of beta interferon and interferon regulatory factor 3 (IRF-3)-dependent promoters, as well as the nuclear translocation of IRF-3. Consistent with this observation, TCRV-infected cells also failed to inhibit interferon production.
Crystallographic and Biochemical Analysis of Rotavirus NSP2 with Nucleotides Reveals a Nucleoside Diphosphate Kinase-Like Activity
Authors: Kumar Mukesh , Jayaram Hariharan , Vasquez-Del Carpio Rodrigo , Jiang Xiaofang , Taraporewala Zenobia F. , Jacobson Raymond H. , Patton John T. , Prasad B. V. Venkataram 
Published: September 2007

ABSTRACT

Rotavirus, the major pathogen of infantile gastroenteritis, carries a nonstructural protein, NSP2, essential for viroplasm formation and genome replication/packaging. In addition to RNA-binding and helix-destabilizing properties, NSP2 exhibits nucleoside triphosphatase activity. A conserved histidine (H225) functions as the catalytic residue for this enzymatic activity, and mutation of this residue abrogates genomic double-stranded RNA synthesis without affecting viroplasm formation. To understand the structural basis of the phosphatase activity of NSP2, we performed crystallographic analyses of native NSP2 and a functionally defective H225A mutant in the presence of nucleotides. These studies showed that nucleotides bind inside a cleft between the two domains of NSP2 in a region that exhibits structural similarity to ubiquitous cellular HIT (
hi
stidine
t
riad) proteins. Only minor conformational alterations were observed in the cleft upon nucleotide binding and hydrolysis. This hydrolysis involved the formation of a stable phosphohistidine intermediate. These observations, reminiscent of cellular nucleoside diphosphate (NDP) kinases, prompted us to investigate whether NSP2 exhibits phosphoryl-transfer activity. Bioluminometric assay showed that NSP2 exhibits an NDP kinase-like activity that transfers the bound phosphate to NDPs. However, NSP2 is distinct from the highly conserved cellular NDP kinases in both its structure and catalytic mechanism, thus making NSP2 a potential target for antiviral drug design. With structural similarities to HIT proteins, which are not known to exhibit NDP kinase activity, NSP2 represents a unique example among structure-activity relationships. The newly observed phosphoryl-transfer activity of NSP2 may be utilized for homeostasis of nucleotide pools in viroplasms during genome replication.
Efficient Thymopoiesis Contributes to the Maintenance of Peripheral CD4 T Cells during Chronic Human Immunodeficiency Virus Type 2 Infection
Authors: Gautier David , Beq Stéphanie , Cortesão Catarina S. , Sousa Ana E. , Cheynier Rémi 
Published: September 2007

ABSTRACT
Human immunodeficiency virus type 2 (HIV-2) infection leads to a lifelong asymptomatic period in the majority of patients. Even in patients with progressive disease, a slow CD4 count decline characterizes the chronic phase of HIV-2 infection, suggesting that peripheral T-cell homeostasis is controlled better following HIV-2 infection than following HIV-1 infection. Herein we showed that, in contrast to HIV-1-infected patients, HIV-2-infected patients demonstrate enhanced thymic function compared to age-matched healthy individuals. The correlation between higher thymic production and lower CD4 T-cell loss in these patients suggests that efficient thymopoiesis is implicated in the long-lasting maintenance of CD4 T-cell counts in HIV-2 disease.
A Single-Amino-Acid Substitution in the P2 Domain of VP1 of Murine Norovirus Is Sufficient for Escape from Antibody Neutralization
Authors: Lochridge Vance P. , Hardy Michele E. 
Published: September 2007

ABSTRACT
Noroviruses cause epidemic outbreaks of acute viral gastroenteritis worldwide, and the number of reported outbreaks is increasing. Human norovirus strains do not grow in cell culture. However, murine norovirus (MNV) replicates in the RAW 264.7 macrophage cell line and thus provides a tractable model to investigate norovirus interactions with host cells. Epitopes recognized by monoclonal antibodies (MAbs) against the human norovirus strains Norwalk virus and Snow Mountain virus (SMV) identified regions in the P domain of major capsid protein VP1 important for interactions with putative cellular receptors. To determine if there was a relationship between domains of MNV VP1 and VP1 of human norovirus strains involved in cell binding, epitope mapping by phage display was performed with an MNV-1-neutralizing MAb, A6.2.1. A consensus peptide, GWWEDHGQL, was derived from 20 third-round phage clones. A synthetic peptide containing this sequence and constrained through a disulfide linkage reacted strongly with the A6.2.1 MAb, whereas the linear sequence did not. Four residues in the A6.2.1-selected peptide, G327, G333, Q334, and L335, aligned with amino acid residues in the P2 domain of MNV-1 VP1. This sequence is immediately adjacent to the epitope recognized by anti-SMV MAb 61.21. Neutralization escape mutants selected with MAb A6.2.1 contained a leucine-to-phenylalanine substitution at position 386 in the P2 domain. The predicted location of these residues on VP1 suggests that the phage peptide and the mutation in the neutralization-resistant viruses may be in close proximity to each other and to residues reported to be important for carbohydrate binding to VP1 of human norovirus strains.
Claudin-6 and Claudin-9 Function as Additional Coreceptors for Hepatitis C Virus
Authors: Zheng Aihua , Yuan Fei , Li Yanqin , Zhu Fangfang , Hou Pingping , Li Jianqing , Song Xijun , Ding Mingxiao , Deng Hongkui 
Published: September 2007

ABSTRACTHepatitis C virus (HCV) is a global challenge to public health. Several factors have been proven to be critical for HCV entry, including the newly identified claudin-1 (CLDN1). However, the mechanism of HCV entry is still obscure. Presently, among the 20 members of the claudin family identified in humans so far, CLDN1 has been the only member shown to be necessary for HCV entry. Recently, we discovered that Bel7402, an HCV-permissive cell line, does not express CLDN1 but expresses other members of claudin family. Among these claudins, CLDN9 was able to mediate HCV entry just as efficiently as CLDN1. We then examined if other members of the claudin family could mediate entry. We show that CLDN6 and CLDN9, but not CLDN2, CLDN3, CLDN4, CLDN7, CLDN11, CLDN12, CLDN15, CLDN17, and CLDN23, were able to mediate the entry of HCV into target cells. We found that CLDN6 and CLDN9 are expressed in the liver, the primary site of HCV replication. We also showed that CLDN6 and CLDN9, but not CLDN1, are expressed in peripheral blood mononuclear cells, an additional site of HCV replication. Through sequence comparison and mutagenesis studies, we show that residues N38 and V45 in the first extracellular loop (EL1) of CLDN9 are necessary for HCV entry.
Ternary Complex Formation on the Adenovirus Packaging Sequence by the IVa2 and L4 22-Kilodalton Proteins
Authors: Ewing Sean G. , Byrd Serena A. , Christensen Joan B. , Tyler Ryan E. , Imperiale Michael J. 
Published: September 2007

ABSTRACTAssembly of infectious adenovirus particles requires seven functionally redundant elements at the left end of the genome, termed A repeats, that direct packaging of the DNA. Previous studies revealed that the viral IVa2 protein alone interacts with specific sequences in the A repeats but that additional IVa2-containing complexes observed during infection require the viral L4 22-kDa protein. In this report, we purified a recombinant form of the 22-kDa protein to characterize its DNA binding properties. In electrophoretic mobility shift assay analyses, the 22-kDa protein alone did not interact with the A repeats but it did form complexes on them in the presence of the IVa2 protein. These complexes were identical to those seen in extracts from infected cells and had the same DNA sequence dependence. Furthermore, we provide data that the 22-kDa protein enhances binding of the IVa2 protein to the A repeats and that multiple binding sites in the packaging sequence augment this activity. These data support a cooperative role of the IVa2 and 22-kDa proteins in packaging and assembly.
Signal Peptide Requirements for Lymphocytic Choriomeningitis Virus Glycoprotein C Maturation and Virus Infectivity
Authors: Schrempf Sabrina , Froeschke Marc , Giroglou Tsanan , von Laer Dorothee , Dobberstein Bernhard 
Published: September 2007

ABSTRACT

Insertion of the lymphocytic choriomeningitis virus (LCMV) precursor glycoprotein C (GP-C) into the membrane of the endoplasmic reticulum is mediated by an unusual signal peptide (SP
GP-C
). It is comprised of 58 amino acid residues and contains an extended hydrophilic N-terminal region, two hydrophobic regions, and a short C-terminal region. After cleavage by signal peptidase, SP
GP-C
accumulates in cells and virus particles. In the present study, we identified the LCMV SP
GP-C
as being an essential component of the GP complex and show that the different regions of SP
GP-C
are required for distinct steps in GP maturation and virus infectivity. More specifically, we show that one hydrophobic region of SP
GP-C
is sufficient for the membrane insertion of GP-C, while both hydrophobic regions are required for the processing and cell surface expression of the GPs. The N-terminal region of SP
GP-C
, on the other hand, is essential for pseudoviral infection of target cells. Furthermore, we show that unmyristoylated SP
GP-C
exposes its N-terminal region to the exoplasmic side. This SP
GP-C
can promote GP-C maturation but is defective in pseudoviral infection. Myristoylation and topology of SP
GP-C
in the membrane may thus hold the key to an understanding of the role of SP
GP-C
in GP-C complex maturation and LCMV infectivity.
Escape from the Dominant HLA-B27-Restricted Cytotoxic T-Lymphocyte Response in Gag Is Associated with a Dramatic Reduction in Human Immunodeficiency Virus Type 1 Replication
Authors: Schneidewind Arne , Brockman Mark A. , Yang Ruifeng , Adam Rahma I. , Li Bin , Le Gall Sylvie , Rinaldo Charles R. , Craggs Sharon L. , Allgaier Rachel L. , Power Karen A. , Kuntzen Thomas , Tung Chang-Shung , LaBute Montiago X. , Mueller Sandra M. , Harrer Thomas , McMichael Andrew J. , Goulder Philip J. R. , Aiken Christopher , Brander Christian , Kelleher Anthony D. , Allen Todd M. 
Published: September 2007

ABSTRACTHuman leukocyte antigen (HLA)-B27-positive subjects are uncommon in their ability to control infection with human immunodeficiency virus type 1 (HIV-1). However, late viral escape from a narrowly directed immunodominant Gag-specific CD8+T-lymphocyte (CTL) response has been linked to AIDS progression in these individuals. Identifying the mechanism of the immune-mediated control may provide critical insights into HIV-1 vaccine development. Here, we illustrate that the CTL escape mutation R264K in the HLA-B27-restricted KK10 epitope in the capsid resulted in a significant defect in viral replication in vitro. The R264K variant was impaired in generating late reverse transcription products, indicating that replication was blocked at a postentry step. Notably, the R264K mutation was associated in vivo with the development of a rare secondary mutation, S173A, which restored viral replication in vitro. Furthermore, infectivity of the R264K variant was rescued by the addition of cyclosporine A or infection of a cyclophilin A-deficient cell line. These data demonstrate a severe functional defect imposed by the R264K mutation during an early step in viral replication that is likely due to the inability of this variant to replicate efficiently in the presence of normal levels of cyclophilin A. We conclude that the impact of the R264K substitution on capsid structure constrains viral escape and enables long-term maintenance of the dominant CTL response against B27-KK10, providing an explanation for the protective effect of HLA-B27 during HIV infection.
Digital rectal examination: national survey of undergraduate medical training in Ireland
Authors: Fitzgerald Deirdre , Connolly Stephen S , Kerin Michael J 
Published: September 2007

Abstract

Objective
To assess the experience gained in digital rectal examination (DRE) by medical students in the Republic of Ireland by the completion of undergraduate training.

Methods
A national survey was conducted targeting all 582 final year students from the five medical schools completing their undergraduate studies in the summer of 2005. Format was anonymous questionnaire. Experience of DRE was defined as the student having performed at least one examination on either patient or teaching mannequin.

Results
In total, 396 (68%) of 582 students responded. No experience of DRE was reported in 97 (24%), with mannequin-only experience in a further 78 (20%). Of the remaining 221 (56%) who performed DRE on at least one patient, one third (74) reported no confidence in their ability to interpret their findings properly.

Conclusion
Undergraduate training in DRE is limited. Training in DRE can no longer be reasonably considered part of the core curriculum taught in Irish medical schools.
Carcinoembryonic antigen (CEA) testing in colorectal cancer follow up: what do patients think?
Authors: Steele Nicola , Haigh Rachel , Knowles Gillian , Mackean Melanie 
Published: September 2007

Abstract
The carcinoembryonic antigen (CEA) blood test is included in most colorectal cancer follow up protocols, despite little clear evidence for its cost-effectiveness and survival benefit. In this study, patients' views were sought on the use of the CEA blood test in their follow up. Strong associations were found between the age of a patient's children and their concern about cancer recurrence and between concern about recurrence and anxiety about CEA test results (p&lt;0.0001). Many patients expressed a desire for prognostic information, however uncertain or poor. Patients' views should be sought when designing colorectal cancer follow up protocols to ensure their needs are adequately addressed.
Basal, but not overload-induced, myonuclear addition is attenuated by NG-nitro-l-arginine methyl ester (l-NAME) administration
Authors: Gordon Scott E. , Westerkamp Christopher M. , Savage Kathleen J. , Hickner Robert C. , George Sarah C. , Fick Christopher A. , McCormick Kathleen M. 
Published: September 2007

The purpose of this study was to examine the effect of blocking nitric oxide synthase (NOS) activity via NG-nitro-l-arginine methyl ester (l-NAME) on myonuclear addition in skeletal muscle under basal and overloaded conditions. Female Sprague–Dawley rats (approx. 220 g) were placed into 1 of the following 4 groups (n = 7–9/group): 7-day skeletal muscle overload (O), sham operation (S), skeletal muscle overload with l-NAME treatment (OLN), and sham operation with l-NAME treatment (SLN). Plantaris muscles were overloaded via bilateral surgical ablation of the gastrocnemius muscles and l-NAME (0.75 mg/mL) was administered in the animals’ daily drinking water starting 2 days prior to surgery and continued until sacrifice. Myonuclear addition was assessed as subsarcolemmal incorporation of nuclei labeled with 5-bromo-2′-deoxyuridine (approx. 25 mg·(kg body mass)–1·day–1) delivered via osmotic pump during the overload period. As expected, muscle wet mass, total protein content, fiber cross-sectional area, and myonuclear addition were significantly higher (p ≤ 0.05) in O vs. S; however, only the increase in wet mass and total protein content (per body mass) were attenuated by l-NAME administration. Interestingly, l-NAME significantly reduced myonuclear addition by 75% in nonoverloaded muscles (SLN vs. S). Muscle hepatocyte growth factor protein content increased with overload, but was unaffected by l-NAME in either loading state. These data indicate that NOS inhibition in rat plantaris muscle attenuates myonuclear addition under basal, but not overloaded, conditions.