bluuebunny/crossref_metadata_2025_split huggingface dataset:
Occurrence of human papillomavirus in pterygia
Authors: Piecyk‐Sidor Marta , Polz‐Dacewicz Małgorzata , Zagórski Zbigniew , Żarnowski Tomasz 
Published: March 2009

Abstract.Purpose:  The aim of the study was to assess the occurrence of human papillomavirus (HPV) DNA in pterygium.Methods:  The study involved 89 patients undergoing surgical procedures at the Department of Ophthalmology, Medical University of Lublin, Poland. Group 1 included 58 patients with clinically diagnosed pterygium. Group 2 consisted of 31 individuals with normal conjunctiva. The material was collected during elective surgical procedures. The presence of HPV genome was determined using polymerase chain reaction (PCR). Once the presence of HPV DNA was confirmed, 28 HPV genotypes were determined using reverse hybridization.Results:  The determinations confirmed the presence of HPV DNA in pterygium. In the material collected from 58 cases of pterygium (group 1), HPV DNA was identified in 16 patients (27.6%). In the material from 31 diagnostic specimens of normal conjunctiva (group 2), the presence of HPV was demonstrated in three cases (9.7%). A statistically significant difference was found in the presence of HPV DNA between the patients from groups 1 and 2 (p = 0.041). HPV type 16 was most common and was demonstrated in 56% of HPV‐positive cases of pterygium. HPV 16 and HPV 6 co‐infections were found in 19% of cases, while HPV 18 and HPV 6 co‐infections were observed in 13%. In group 2, all three patients with HPV showed HPV 18.Conclusion:  It seems that HPV is not necessary to induce pterygium; however, it might play a synergistic role in the multi‐stage process of its development.
Axonal loss occurs early in dominant optic atrophy
Authors: Milea Dan , Sander Birgit , Wegener Marianne , Jensen Hanne , Kjer Birgit , Jørgensen Thomas Martini , Lund‐Andersen Henrik , Larsen Michael 
Published: March 2009

Abstract.Purpose:  This study set out to investigate retinal nerve fibre layer (RNFL) thickness and best corrected visual acuity (BCVA) in relation to age in healthy subjects and patients with OPA1 autosomal dominant optic atrophy (DOA).Methods:  We carried out a cross‐sectional investigation of RNFL thickness and ganglion cell layer density in 30 healthy subjects and 10 patients with OPA1 DOA using optical coherence tomography (OCT). We then performed a regression analysis of RNFL thickness and BCVA versus age.Results:  Both healthy subjects and DOA patients demonstrated a gradual reduction in RNFL thickness with age; the relationship was best described statistically by a model that assumed a constant offset between the two groups. Best corrected VA decreased significantly with age in DOA patients, in whom BCVA was correlated with peripapillary RNFL thickness in the inferior and superior peripapillary quadrants and with total macular thickness at eccentricities of 500–3000 μm. The observations were best described by a constant offset of 41.9 μm separating the two groups and an annual decrease in RNFL thickness of 0.48 μm (p < 0.0001). In patients with DOA, increasing age was associated with decreasing BCVA (p = 0.046).Conclusions:  This cross‐sectional study found evidence of comparable age‐related decreases in RNFL thickness in healthy subjects and in DOA patients, where the deficit in DOA patients is best described using a model that assumes the deficit between the groups does not vary with age. The gradual reduction of BCVA with age may be a consequence of a relative deficit in RNFL thickness that is established before the second decade of life.
Increased Myeloperoxidase Activity and Protein Nitration Are Indicators of Inflammation in Patients with Chagas' Disease
Authors: Dhiman Monisha , Estrada-Franco Jose Guillermo , Pando Jasmine M. , Ramirez-Aguilar Francisco J. , Spratt Heidi , Vazquez-Corzo Sara , Perez-Molina Gladys , Gallegos-Sandoval Rosa , Moreno Roberto , Garg Nisha Jain 
Published: March 2009

ABSTRACT

In this study, we investigated whether inflammatory responses contribute to oxidative/nitrosative stress in patients with Chagas' disease. We used three tests (enzyme-linked immunosorbent assay, immuno-flow cytometry, and STAT-PAK immunochromatography) to screen human serum samples (
n
= 1,481) originating from Chiapas, Mexico, for
Trypanosoma cruzi
-specific antibodies. We identified 121 subjects who were seropositive for
T. cruzi-
specific antibodies, a finding indicative of an 8.5% seroprevalence in the rural population from Chiapas. Seropositive and seronegative subjects were examined for plasma levels of biomarkers of inflammation, i.e., myeloperoxidase (MPO), inducible nitric oxide synthase (iNOS), and xanthine oxidase (XOD), as well as for oxidative (advanced oxidation protein products [AOPPs]) and nitrosative (3-nitrotyrosine [3NT]) biomarkers. The seropositive subjects exhibited a significant increase in MPO activity and protein level, the indicator of neutrophil activation. Subsequently, a corresponding increase in AOPP contents, formed by MPO-dependent hypochlorous acid and chloramine formation, was noted in seropositive subjects. The plasma level of 3NT was significantly increased in seropositive subjects, yet we observed no change in XOD activity (O
2
−
source) and nitrate/nitrite contents (denotes iNOS activation and NO production), which implied that direct peroxynitrite formation does not contribute to increased nitrosative damage in chagasic subjects. Instead, a positive correlation between increased MPO activity and protein 3NT formation was observed, which suggested to us that MPO-dependent formation of nitrylchloride that occurs in the presence of physiological NO and O
2
−
concentrations contributes to protein nitration. Overall, our data demonstrate that
T. cruzi-
induced neutrophil activation is pathological and contributes to MPO-mediated collateral protein oxidative and nitrosative damage in human patients with Chagas' disease. Therapies capable of suppressing MPO activity may be useful in controlling the inflammation and oxidative/nitrosative pathology in chagasic cardiomyopathy.
Potential Use of the Hemagglutinin-Neuraminidase Glycoprotein of Newcastle Disease Virus Expressed in
Rachiplusia nu
Larvae as an Immunogen for Chickens
Authors: Chimeno Zoth Silvina , Gómez Evangelina , Carballeda Juan Manuel , Taboga Oscar , Carrillo Elisa , Berinstein Analía 
Published: March 2009

ABSTRACT

The hemagglutinin-neuraminidase glycoprotein of Newcastle disease virus (NDV) was obtained as a recombinant antigen in
Rachiplusia nu
larvae. When it was used as an immunogen in chickens, a solid immune response, including neutralizing antibodies, was detected, demonstrating the potential use of this simple and economic strategy in the design of recombinant anti-NDV vaccines.
Cholera Outbreaks Caused by an Altered
Vibrio cholerae
O1 El Tor Biotype Strain Producing Classical Cholera Toxin B in Vietnam in 2007 to 2008
Authors: Nguyen Binh Minh , Lee Je Hee , Cuong Ngo Tuan , Choi Seon Young , Hien Nguyen Tran , Anh Dang Duc , Lee Hye Ri , Ansaruzzaman M. , Endtz Hubert P. , Chun Jongsik , Lopez Anna Lena , Czerkinsky Cecil , Clemens John D. , Kim Dong Wook 
Published: March 2009

ABSTRACT

Vibrio cholerae
O1 isolates collected during cholera outbreaks occurring from late 2007 to early 2008 in northern Vietnam were revealed to represent an altered strain containing the RS1 element followed by a CTX prophage harboring El Tor type
rstR
and classical
ctxB
on the large chromosome.
Distribution of Hepatitis B Virus Genotypes among Patients with Chronic Infection in Japan Shifting toward an Increase of Genotype A
Authors: Matsuura Kentaro , Tanaka Yasuhito , Hige Shuhei , Yamada Gotaro , Murawaki Yoshikazu , Komatsu Masafumi , Kuramitsu Tomoyuki , Kawata Sumio , Tanaka Eiji , Izumi Namiki , Okuse Chiaki , Kakumu Shinichi , Okanoue Takeshi , Hino Keisuke , Hiasa Yoichi , Sata Michio , Maeshiro Tatsuji , Sugauchi Fuminaka , Nojiri Shunsuke , Joh Takashi , Miyakawa Yuzo , Mizokami Masashi 
Published: March 2009

ABSTRACT

Acute hepatitis B virus (HBV) infection has been increasing through promiscuous sexual contacts, and HBV genotype A (HBV/A) is frequent in patients with acute hepatitis B (AHB) in Japan. To compare the geographic distribution of HBV genotypes in patients with chronic hepatitis B (CHB) in Japan between 2005 and 2006 and between 2000 and 2001, with special attention to changes in the proportion of HBV/A, a cohort study was performed to survey changes in genotypes of CHB patients at 16 hospitals throughout Japan. Furthermore, we investigated the clinical characteristics of each genotype and examined the genomic characteristics of HBV/A isolates by molecular evolutionary analyses. Of the 1,271 patients, 3.5%, 14.1%, and 82.3% were infected with HBV/A, -B, and -C, respectively. In comparison with our previous survey during 2000 and 2001, HBV/A was twice as frequent (3.5% versus 1.7%;
P
= 0.02). The mean age was lower in the patients with HBV/A than in those with HBV/B or -C. Based on phylogenetic analyses of 11 full-length genomes and 29 pre-S2/S region sequences from patients, HBV/A isolates were imported from Europe and the United States, as well as the Philippines and India. They clustered with HBV/A from AHB patients and have spread throughout Japan. HBV/A has been increasing in CHB patients in Japan as a consequence of AHB spreading in the younger generation through promiscuous sexual contacts, aided by a tendency of HBV/A to induce chronic hepatitis. The spread of HBV/A infection in Japan should be prevented by universal vaccination programs.
Evidence that Productive Human Immunodeficiency Virus Type 1 Assembly Can Occur in an Intracellular Compartment
Authors: Joshi Anjali , Ablan Sherimay D. , Soheilian Ferri , Nagashima Kunio , Freed Eric O. 
Published: March 2009

ABSTRACT
Human immunodeficiency virus type 1 (HIV-1) assembly occurs predominantly at the plasma membrane of infected cells. The targeting of assembly to intracellular compartments such as multivesicular bodies (MVBs) generally leads to a significant reduction in virus release efficiency, suggesting that MVBs are a nonproductive site for HIV-1 assembly. In the current study, we make use of an HIV-1 Gag-matrix mutant, 29/31KE, that is MVB targeted. We previously showed that this mutant is severely defective for virus particle production in HeLa cells but more modestly affected in primary macrophages. To more broadly examine the consequences of MVB targeting for virus production, we investigated 29/31KE particle production in a range of cell types. Surprisingly, this mutant supported highly efficient assembly and release in T cells despite its striking MVB Gag localization. Manipulation of cellular endocytic pathways revealed that unlike Vpu-defective HIV-1, which demonstrated intracellular Gag localization as a result of Gag endocytosis from the plasma membrane, 29/31KE mutant Gag was targeted directly to an MVB compartment. The 29/31KE mutant was unable to support multiple-round replication; however, this defect could be reversed by truncating the cytoplasmic tail of the transmembrane envelope glycoprotein gp41 and by the acquisition of a 16EK change in matrix. The 16EK/29/31KE matrix mutant replicated efficiently in the MT-4 T-cell line despite maintaining an MVB-targeting phenotype. These results indicate that MVB-targeted Gag can be efficiently released from T cells and primary macrophages, suggesting that under some circumstances, late endosomal compartments can serve as productive sites for HIV-1 assembly in these physiologically relevant cell types.
Restriction of Human Polyomavirus BK Virus DNA Replication in Murine Cells and Extracts
Authors: Mahon Cathal , Liang Bo , Tikhanovich Irina , Abend Johanna R. , Imperiale Michael J. , Nasheuer Heinz P. , Folk William R. 
Published: March 2009

ABSTRACT
BK virus (BKV) causes persistent and asymptomatic infections in most humans and is the etiologic agent of polyomavirus-associated nephropathy (PVAN) and other pathologies. Unfortunately, there are no animal models with which to study activation of BKV replication in the human kidney and the accompanying PVAN. Here we report studies of the restriction of BKV replication in murine cells and extracts and the cause(s) of this restriction. Upon infection of murine cells, BKV expressed large T antigen (TAg), but viral DNA replication and progeny were not detected. Transfection of murine cells with BKV TAg expression vectors also caused TAg expression without accompanying DNA replication. Analysis of the replication of DNAs containing chimeric BKV and murine polyomavirus origins revealed the importance of BKV core origin sequences and TAg for DNA replication. A sensitive assay was developed with purified BKV TAg that supported TAg-dependent BKV DNA replication with human but not with murine cell extracts. Addition of human replication proteins, DNA polymerase α-primase, replication protein A, or topoisomerase I to the murine extracts with BKV TAg did not rescue viral DNA replication. Notably, addition of murine extracts to human extracts inhibited BKV TAg-dependent DNA replication at a step prior to or during unwinding of the viral origin. These findings and differences in replication specificity between BKV TAg and the TAgs of simian virus 40 (SV40) and JC virus (JCV) and their respective origins implicate features of the BKV TAg and origin distinct from SV40 and JCV in restriction of BKV replication in murine cells.
Impaired Cholesterol Biosynthesis in a Neuronal Cell Line Persistently Infected with Measles Virus
Authors: Robinzon Shahar , Dafa-Berger Avis , Dyer Mathew D. , Paeper Bryan , Proll Sean C. , Teal Thomas H. , Rom Slava , Fishman Daniel , Rager-Zisman Bracha , Katze Michael G. 
Published: March 2009

ABSTRACT
Measles virus remains a substantial cause of morbidity and mortality, producing acute infection with a potential for development of viral persistence. To study the events underlying acute and persistent measles virus infection, we performed a global transcriptional analysis on murine neuroblastoma cells that were acutely or persistently infected with measles virus. In general, we found that acute infection induced significantly more gene expression changes than did persistent infection. A functional enrichment analysis to identify which host pathways were perturbed during each of these infections identified several pathways related to cholesterol biosynthesis, including cholesterol metabolic processes, hydroxymethylglutaryl-coenzyme A (CoA) reductase activity, and acetyl-CoA C-acetyltransferase activity. We also found that measles virus colocalized to lipid rafts in both acute and persistent infection models and that the majority of genes associated with cholesterol synthesis were downregulated in persistent infection relative to acute infection, suggesting a possible link with the defective viral budding in persistent infection. Further, we found that pharmacological inhibition of cholesterol synthesis resulted in the inhibition of viral budding during acute infection. In summary, persistent measles viral infection was associated with decreased cholesterol synthesis, a lower abundance of cholesterol and lipid rafts in the cell membrane, and inhibition of giant-cell formation and release of viral progeny.
The C Terminus of the Polerovirus P5 Readthrough Domain Limits Virus Infection to the Phloem
Authors: Peter Kari A. , Gildow Frederick , Palukaitis Peter , Gray Stewart M. 
Published: March 2009

ABSTRACT

Poleroviruses are restricted to vascular phloem tissues from which they are transmitted by their aphid vectors and are not transmissible mechanically. Phloem limitation has been attributed to the absence of virus proteins either facilitating movement or counteracting plant defense. The polerovirus capsid is composed of two forms of coat protein, the major P3 protein and the minor P3/P5 protein, a translational readthrough of P3. P3/P5 is required for insect transmission and acts in
trans
to facilitate long-distance virus movement in phloem tissue. Specific potato leafroll virus mutants lacking part or all of the P5 domain moved into and infected nonvascular mesophyll tissue when the source-sink relationship of the plant (
Solanum sarrachoides
) was altered by pruning, with the progeny virus now being transmissible mechanically. However, in a period of months, a phloem-specific distribution of the virus was reestablished in the absence of aphid transmission. Virus from the new phloem-limited infection showed compensatory mutations that would be expected to restore the production of full-length P3/P5 as well as the loss of mechanical transmissibility. The data support our hypothesis that phloem limitation in poleroviruses presumably does not result from a deficiency in the repertoire of virus genes but rather results from P3/P5 accumulation under selection in the infected plant, with the colateral effect of facilitating transmission by phloem-feeding aphid vectors.
Acquisition of a Polybasic Hemagglutinin Cleavage Site by a Low-Pathogenic Avian Influenza Virus Is Not Sufficient for Immediate Transformation into a Highly Pathogenic Strain
Authors: Stech Olga , Veits Jutta , Weber Siegfried , Deckers Daniela , Schröer Diana , Vahlenkamp Thomas W. , Breithaupt Angele , Teifke Jens , Mettenleiter Thomas C. , Stech Jürgen 
Published: March 2009

ABSTRACT
Highly pathogenic avian influenza viruses (HPAIV) differ from all other strains by a polybasic cleavage site in their hemagglutinin. All these HPAIV share the H5 or H7 subtype. In order to investigate whether the acquisition of a polybasic cleavage site by an avirulent avian influenza virus strain with a hemagglutinin other than H5 or H7 is sufficient for immediate transformation into an HPAIV, we adapted the hemagglutinin cleavage site of A/Duck/Ukraine/1/1963 (H3N8) to that of the HPAIV A/Chicken/Italy/8/98 (H5N2), A/Chicken/HongKong/220/97 (H5N1), or A/Chicken/Germany/R28/03 (H7N7) and generated the recombinant wild-type and cleavage site mutants. In contrast to the wild type, multicycle replication of these mutants in tissue culture was demonstrated by positive plaque assays and viral multiplication in the absence of exogenous trypsin. Therefore, in vitro all cleavage site mutants resemble an HPAIV. However, in chicken they did not exhibit high pathogenicity, although they could be reisolated from cloacal swabs to some extent, indicating enhanced replication in vivo. These results demonstrate that beyond the polybasic hemagglutinin cleavage site, the virulence of HPAIV in chicken is based on additional pathogenicity determinants within the hemagglutinin itself or in the other viral proteins. Taken together, these observations support the notion that acquisition of a polybasic hemagglutinin cleavage site by an avirulent strain with a non-H5/H7 subtype is only one among several alterations necessary for evolution into an HPAIV.
Helices α2 and α3 of West Nile Virus Capsid Protein Are Dispensable for Assembly of Infectious Virions
Authors: Schlick Petra , Taucher Christian , Schittl Beate , Tran Janina L. , Kofler Regina M. , Schueler Wolfgang , von Gabain Alexander , Meinke Andreas , Mandl Christian W. 
Published: March 2009

ABSTRACTThe internal hydrophobic sequence within the flaviviral capsid protein (protein C) plays an important role in the assembly of infectious virions. Here, this sequence was analyzed in a West Nile virus lineage I isolate (crow V76/1). An infectious cDNA clone was constructed and used to introduce deletions into the internal hydrophobic domain which comprises helix α2 and part of the loop intervening helices α2 and α3. In total, nine capsid deletion mutants (4 to 14 amino acids long) were constructed and tested for virus viability. Some of the short deletions did not significantly affect growth in cell culture, whereas larger deletions removing almost the entire hydrophobic region significantly impaired viral growth. Efficient growth of the majority of mutants could, however, be restored by the acquisition of second-site mutations. In most cases, these resuscitating mutations were point mutations within protein C changing individual amino acids into more hydrophobic residues, reminiscent of what had been observed previously for another flavivirus, tick-borne encephalitis virus. However, we also identified viable spontaneous pseudorevertants with more than one-third of the capsid protein removed, i.e., 36 or 37 of a total of 105 residues, including all of helix α3 and a hydrophilic segment connecting α3 and α4. These large deletions are predicted to induce formation of large, predominantly hydrophobic fusion helices which may substitute for the loss of the internal hydrophobic domain, underlining the unrivaled structural and functional flexibility of protein C.
Finite element analysis of an embankment on a soft estuarine deposit using an elastic–viscoplastic soil model
Authors: Kelln Curtis , Sharma Jitendra , Hughes David , Graham James 
Published: March 2009

A new elastic–viscoplastic (EVP) soil model has been used to simulate the measured deformation response of a soft estuarine soil loaded by a stage-constructed embankment. The simulation incorporates prefabricated vertical drains installed in the foundation soils and reinforcement installed at the base of the embankment. The numerical simulations closely matched the temporal changes in surface settlement beneath the centerline and shoulder of the embankment. More importantly, the elastic–viscoplastic model simulated the pattern and magnitudes of the lateral deformations beneath the toe of the embankment — a notoriously difficult aspect of modelling the deformation response of soft soils. Simulation of the excess pore-water pressure proved more difficult because of the heterogeneous nature of the estuarine deposit. Excess pore-water pressures were, however, mapped reasonably well at three of the six monitoring locations. The simulations were achieved using a small set of material constants that can easily be obtained from standard laboratory tests. This study validates the use of the EVP model for problems involving soft soil deposits beneath loading from a geotechnical structure.
Detecting Precipitating Clouds over Snow and Ice Using a Multiple Sensors Approach
Authors: Todini G. , Rizzi R. , Todini E. 
Published: March 2009

Abstract
This work discusses a snowfall detection approach for high-latitude regions that is based on a combination of passive sensors to discriminate between snowing and nonsnowing areas. Two different techniques have been developed to compute the probability of detecting a snowing event. The first technique is based on a logistic distribution to represent the probability of snowfall given the predictors; the second is a Bayesian technique not requiring any hypothesis as to the shape of the probabilistic model. The spaceborne Advanced Microwave Sounding Units A and B (on NOAA-16) and the Moderate Resolution Imaging Spectroradiometer (on Aqua) have been collocated and used for the estimation. Products from the spaceborne cloud-profiling radar on CloudSat are used as truth to calibrate and validate the proposed approaches. A comparison with a well-known rain-rate model, developed by the Remote Sensing and Estimation Group of the Massachusetts Institute of Technology, is also presented, showing that both proposed methods discriminate snowing and nonsnowing condition over the polar regions, reducing by at least 30% the false alarms while considerably increasing the probability of detection.