bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characterization of Virulence Properties of Listeria monocytogenes Serotype 4b Strains of Different Origins
Authors: Werbrouck H. , Botteldoorn N. , Ceelen L. , Decostere A. , Uyttendaele M. , Herman L. , Van Coillie E. 
Published: May 2008

SummaryIn this study, the virulence heterogeneity of Listeria monocytogenes serotype 4b strains of different origins was analysed on different levels. On one hand, the survival of L. monocytogenes strains in synthetic gastric fluid was studied. On the other hand, the pathogenic potential of strains with different inlB expression levels was analysed in an A/J mouse model for gastrointestinal listeriosis. Differences in survival capacity in gastric fluid and in in vivo virulence potential were observed between the tested strains. No clear correlation between the origin and the obtained data could be made. However, these results confirm the existence of heterogeneity in virulence potential of L. monocytogenes serotype 4b strains.
Human Serum Contains a Protease That Protects against Cytotoxic Activity of
Bacillus anthracis
Lethal Toxin In Vitro
Authors: Goldman David L. , Zeng WangYong , Rivera Johanna , Nakouzzi Antonio , Casadevall Arturo 
Published: May 2008

ABSTRACT

The role of innate immunity in the host response to
Bacillus anthracis
is poorly understood. We found that normal human serum contains an antitoxin mechanism that is capable of protecting macrophages in vitro from
B. anthracis
lethal toxin-mediated killing. This protective activity was limited to defined amounts of toxin and was lost by heat treatment or serum dilution. Some person-to-person variation in the protective activity of serum was noted, especially with higher concentrations of lethal toxin. A similar protective activity was found in murine serum, though human serum consistently neutralized more toxin than did murine serum. The protective activities of both murine and human sera correlated with cleavage of the protective antigen into two fragments with approximate molecular sizes of 20 and 50 kDa that were recognized by the monoclonal antibodies 7.5G and 10F4, respectively. This pattern of fragmentation is consistent with cleavage at multiple sites, including the furin-susceptible site. Cleavage was abolished by heat treatment and calcium chelation. These findings highlight a potential role for serum proteases in protection against the lethal toxin of
B. anthracis
.
Development and Characterization of an Equine Infectious Anemia Virus Env-Pseudotyped Reporter Virus
Authors: Tallmadge R. L. , Brindley M. A. , Salmans J. , Mealey R. H. , Maury W. , Carpenter S. 
Published: May 2008

ABSTRACT
We developed a replication-defective reporter virus pseudotyped with the envelope glycoprotein of equine infectious anemia virus (EIAV). The in vitro host range and neutralization phenotype of EIAV Env-pseudotyped virus were similar to those of replication-competent virus. An EIAV Env pseudovirus will improve antigenic characterization of viral variants and evaluation of lentivirus vaccines.
Multiplex PCR and Oligonucleotide Microarray for Detection of Single-Nucleotide Polymorphisms Associated with
Plasmodium falciparum
Drug Resistance
Authors: Zhang Guo Qing , Guan Ya Yi , Sheng Hai Hui , Zheng Bin , Wu Song , Xiao Hua Sheng , Tang Lin Hua 
Published: May 2008

ABSTRACT

Drug resistance in
Plasmodium falciparum
is a serious public health threat in the countries where this organism is endemic. Since resistance has been associated with specific single-nucleotide polymorphisms (SNPs) in parasite genes, molecular markers are becoming useful surrogates for monitoring the emergence and dispersion of drug resistance. In this study, a multiplex PCR (mPCR) and oligonucleotide microarray method was developed for the detection of these SNPs in genes encoding chloroquine resistance transporter (Pf
crt
), multidrug resistance 1 (Pf
mdr1
), dihydrofolate reductase (Pf
dhfr
), dihydropteroate synthetase (Pf
dhps
), and ATPase 6 (Pf
ATPase6
) of
P. falciparum
. The results show that DNA microarray technology, combined with mPCR, is a promising and time-saving tool that supports conventional detection methods, allowing sensitive, accurate, simultaneous analysis of the SNPs associated with drug resistance in
P. falciparum
.
Occult Hepatitis C Virus Infection Revisited with Ultrasensitive Real-Time PCR Assay
Authors: Halfon Philippe , Bourlière Marc , Ouzan Denis , Sène Damien , Saadoun David , Khiri Hacène , Pénaranda Guillaume , Martineau Agnes , Oulès Valérie , Cacoub Patrice 
Published: May 2008

ABSTRACT
Occult hepatitis C infection is regarded as a new entity that should be considered when diagnosing patients with a liver disease of unknown origin. Using an ultrasensitive real-time PCR assay, we demonstrated that occult hepatitis C virus (HCV) infection cannot be found in peripheral blood mononuclear cells of patients with cryptogenic liver diseases, HCV-associated systemic vasculitis, or connective tissue diseases. The significance of such occult infection must be elucidated.
Method To Detect Only Live Bacteria during PCR Amplification
Authors: Soejima Takashi , Iida Ken-ichiro , Qin Tian , Taniai Hiroaki , Seki Masanori , Yoshida Shin-ichi 
Published: May 2008

ABSTRACTEthidium monoazide (EMA) is a DNA cross-linking agent and eukaryotic topoisomerase II poison. We previously reported that the treatment of EMA with visible light irradiation (EMA + Light) directly cleaved chromosomal DNA ofEscherichia coli(T. Soejima, K. Iida, T. Qin, H. Taniai, M. Seki, A. Takade, and S. Yoshida, Microbiol. Immunol.51:763-775, 2007). Herein, we report that EMA + Light randomly cleaved chromosomal DNA of heat-treated, but not live,Listeria monocytogenescells within 10 min of treatment. When PCR amplified DNA that was 894 bp in size, PCR final products from 108heat-treatedL. monocytogeneswere completely suppressed by EMA + Light. When target DNA was short (113 bp), like thehlygene ofL. monocytogenes, DNA amplification was not completely suppressed by EMA + Light only. Thus, we used DNA gyrase/topoisomerase IV and mammalian topoisomerase poisons (here abbreviated as T-poisons) together with EMA + Light. T-poisons could penetrate heat-treated, but not live,L. monocytogenescells within 30 min to cleave chromosomal DNA by poisoning activity. The PCR product of thehlygene from 108heat-treatedL. monocytogenescells was inhibited by a combination of EMA + Light and T-poisons (EMA + Light + T-poisons), but those from live bacteria were not suppressed. As a model for clinical application to bacteremia, we tried to discriminate live and antibiotic-treatedL. monocytogenescells present in human blood. EMA + Light + T-poisons completely suppressed the PCR product from 103to 107antibiotic-treatedL. monocytogenescells but could detect 102live bacteria. Considering the prevention and control of food poisoning, this method was applied to discriminate live and heat-treatedL. monocytogenescells spiked into pasteurized milk. EMA + Light + T-poisons inhibited the PCR product from 103to 107heat-treated cells but could detect 101liveL. monocytogenescells. Our method is useful in clinical as well as food hygiene tests.
The Temperate Marine Phage ΦHAP-1 of
Halomonas aquamarina
Possesses a Linear Plasmid-Like Prophage Genome
Authors: Mobberley Jennifer M. , Authement R. Nathan , Segall Anca M. , Paul John H. 
Published: May 2008

ABSTRACT

A myovirus-like temperate phage, ΦHAP-1, was induced with mitomycin C from a
Halomonas aquamarina
strain isolated from surface waters in the Gulf of Mexico. The induced cultures produced significantly more virus-like particles (VLPs) (3.73 × 10
10
VLP ml
−1
) than control cultures (3.83 × 10
7
VLP ml
−1
) when observed with epifluorescence microscopy. The induced phage was sequenced by using linker-amplified shotgun libraries and contained a genome 39,245 nucleotides in length with a G+C content of 59%. The ΦHAP-1 genome contained 46 putative open reading frames (ORFs), with 76% sharing significant similarity (E value of <10
−3
) at the protein level with other sequences in GenBank. Putative functional gene assignments included small and large terminase subunits, capsid and tail genes, an N6-DNA adenine methyltransferase, and lysogeny-related genes. Although no integrase was found, the ΦHAP-1 genome contained ORFs similar to protelomerase and
parA
genes found in linear plasmid-like phages with telomeric ends. Southern probing and PCR analysis of host genomic, plasmid, and ΦHAP-1 DNA indicated a lack of integration of the prophage with the host chromosome and a difference in genome arrangement between the prophage and virion forms. The linear plasmid prophage form of ΦHAP-1 begins with the protelomerase gene, presumably due to the activity of the protelomerase, while the induced phage particle has a circularly permuted genome that begins with the terminase genes. The ΦHAP-1 genome shares synteny and gene similarity with coliphage N15 and vibriophages VP882 and VHML, suggesting an evolutionary heritage from an N15-like linear plasmid prophage ancestor.
Hepatitis B Virus HBx Protein Localizes to Mitochondria in Primary Rat Hepatocytes and Modulates Mitochondrial Membrane Potential
Authors: Clippinger Amy J. , Bouchard Michael J. 
Published: May 2008

ABSTRACTOver 350 million people are chronically infected with hepatitis B virus (HBV), and a significant number of chronically infected individuals develop primary liver cancer. HBV encodes seven viral proteins, including the nonstructural X (HBx) protein. The results of studies with immortalized or transformed cells and with HBx-transgenic mice demonstrated that HBx can interact with mitochondria. However, no studies with normal hepatocytes have characterized the precise mitochondrial localization of HBx or the effect of HBx on mitochondrial physiology. We have used cultured primary rat hepatocytes as a model system to characterize the mitochondrial localization of HBx and the effect of HBx expression on mitochondrial physiology. We now show that a fraction of HBx colocalizes with density-gradient-purified mitochondria and associates with the outer mitochondrial membrane. We also demonstrate that HBx regulates mitochondrial membrane potential in hepatocytes and that this function of HBx varies depending on the status of NF-κB activity. In primary rat hepatocytes, HBx activation of NF-κB prevented mitochondrial membrane depolarization; however, when NF-κB activity was inhibited, HBx induced membrane depolarization through modulation of the mitochondrial permeability transition pore. Collectively, these results define potential pathways through which HBx may act in order to modulate mitochondrial physiology, thereby altering many cellular activities and ultimately contributing to the development of HBV-associated liver cancer.
Enhanced Mucosal Immunoglobulin A Response and Solid Protection against Foot-and-Mouth Disease Virus Challenge Induced by a Novel Dendrimeric Peptide
Authors: Cubillos Carolina , de la Torre Beatriz G. , Jakab Annamaria , Clementi Giorgia , Borrás Eva , Bárcena Juan , Andreu David , Sobrino Francisco , Blanco Esther 
Published: May 2008

ABSTRACTThe successful use of a dendrimeric peptide to protect pigs against challenge with foot-and-mouth disease virus (FMDV), which causes the most devastating animal disease worldwide, is described. Animals were immunized intramuscularly with a peptide containing one copy of a FMDV T-cell epitope and branching out into four copies of a B-cell epitope. The four immunized pigs did not develop significant clinical signs upon FMDV challenge, neither systemic nor mucosal FMDV replication, nor was its transmission to contact control pigs observed. The dendrimeric construction specifically induced high titers of FMDV-neutralizing antibodies and activated FMDV-specific T cells. Interestingly, a potent anti-FMDV immunoglobulin A response (local and systemic) was observed, despite the parenteral administration of the peptide. On the other hand, peptide-immunized animals showed no antibodies specific of FMDV infection, which qualifies the peptide as a potential marker vaccine. Overall, the dendrimeric peptide used elicited an immune response comparable to that found for control FMDV-infected pigs that correlated with a solid protection against FMDV challenge. Dendrimeric designs of this type may hold substantial promise for peptide subunit vaccine development.
A Seven-Segmented Influenza A Virus Expressing the Influenza C Virus Glycoprotein HEF
Authors: Gao Qinshan , Brydon Edward W. A. , Palese Peter 
Published: May 2008

ABSTRACT
Influenza viruses are classified into three types: A, B, and C. The genomes of A- and B-type influenza viruses consist of eight RNA segments, whereas influenza C viruses only have seven RNAs. Both A and B influenza viruses contain two major surface glycoproteins: the hemagglutinin (HA) and the neuraminidase (NA). Influenza C viruses have only one major surface glycoprotein, HEF (hemagglutinin-esterase fusion). By using reverse genetics, we generated two seven-segmented chimeric influenza viruses. Each possesses six RNA segments from influenza virus A/Puerto Rico/8/34 (PB2, PB1, PA, NP, M, and NS); the seventh RNA segment encodes either the influenza virus C/Johannesburg/1/66 HEF full-length protein or a chimeric protein HEF-Ecto, which consists of the HEF ectodomain and the HA transmembrane and cytoplasmic regions. To facilitate packaging of the heterologous segment, both the HEF and HEF-Ecto coding regions are flanked by HA packaging sequences. When introduced as an eighth segment with the NA packaging sequences, both viruses are able to stably express a green fluorescent protein (GFP) gene, indicating a potential use for these viruses as vaccine vectors to carry foreign antigens. Finally, we show that incorporation of a GFP RNA segment enhances the growth of seven-segmented viruses, indicating that efficient influenza A viral RNA packaging requires the presence of eight RNA segments. These results support a selective mechanism of viral RNA recruitment to the budding site.
Increase in Near-Surface Atmospheric Moisture Content due to Land Use Changes: Evidence from the Observed Dewpoint Temperature Data
Authors: Mahmood Rezaul , Hubbard Kenneth G. , Leeper Ronnie D. , Foster Stuart A. 
Published: May 2008

Abstract
Land use change can significantly affect root zone soil moisture, surface energy balance, and near-surface atmospheric temperature and moisture content. During the second half of the twentieth century, portions of the North American Great Plains have experienced extensive introduction of irrigated agriculture. It is expected that land use change from natural grass to irrigated land use would significantly increase near-surface atmospheric moisture content. Modeling studies have already shown an enhanced rate of evapotranspiration from the irrigated areas. The present study analyzes observed dewpoint temperature (Td) to assess the affect of irrigated land use on near-surface atmospheric moisture content. This investigation provides a unique opportunity to use long-term (1982–2003) mesoscale Td data from the Automated Weather Data Network of the high plains. Long-term daily Td data from 6 nonirrigated and 11 irrigated locations have been analyzed. Daily time series were developed from the hourly data. The length of time series was the primary factor in selection of these stations. Results suggest increase in growing-season Td over irrigated areas. For example, average growing-season Td due to irrigation can be up to 1.56°C higher relative to nonirrigated land uses. It is also found that Td for individual growing-season month at irrigated locations can be increased up to 2.17°C by irrigation. Based on the results, it is concluded that the land use change in the Great Plains has modified near-surface moistness.
Structure of the Eye and Eyewall of Hurricane Hugo (1989)
Authors: Marks Frank D. , Black Peter G. , Montgomery Michael T. , Burpee Robert W. 
Published: May 2008

Abstract
On 15 September 1989, one of NOAA’s WP-3D research aircraft, N42RF [lower aircraft (LA)], penetrated the eyewall of Hurricane Hugo. The aircraft had an engine fail in severe turbulence while passing the radius of maximum wind and before entering the eye at 450-m altitude. After the aircraft returned to controlled flight within the 7-km radius eye, it gained altitude gradually as it orbited in the eye. Observations taken during this period provide an updated model of the inner-core structure of an intense hurricane and suggest that LA penetrated an intense cyclonic vorticity maximum adjacent to the strongest convection in the eyewall [eyewall vorticity maximum (EVM)]. This EVM was distinct from the vortex-scale cyclonic circulation observed to orbit within the eye three times during the 1 h that LA circled in the eye. At the time, Hugo had been deepening rapidly for 12 h. The maximum flight-level tangential wind was 89 m s−1 at a radius of 12.5 km; however, the primary vortex peak tangential wind, derived from a 100-s filter of the flight-level data, was estimated to be 70 m s−1, also at 12.5-km radius. The primary vortex tangential wind was in approximate gradient wind balance, was characterized by a peak in angular velocity just inside the radius of maximum wind, and had an annular vorticity structure slightly interior to the angular velocity maximum. The EVM along the aircraft’s track was roughly 1 km in diameter with a peak cyclonic vorticity of 1.25 × 10−1 s−1. The larger circulation center, with a diameter &gt;15 km, was observed within the eye and exhibited an average orbital period of 19 min. This period is about the same as that of the angular velocity maximum of the axisymmetric mean vortex and is in reasonable agreement with recent theoretical and model predictions of a persistent trochoidal “wobble” of circulation centers in mature hurricane-like vortices. This study is the first with in situ documentation of these vortical entities, which were recently hypothesized to be elements of a lower-tropospheric eye/eyewall mixing mechanism that supports strong storms.
Climatology of Tropical Cyclogenesis in the North Atlantic (1948–2004)
Authors: McTaggart-Cowan Ron , Deane Glenn D. , Bosart Lance F. , Davis Christopher A. , Galarneau Thomas J. 
Published: May 2008

Abstract
The threat posed to North America by Atlantic Ocean tropical cyclones (TCs) was highlighted by a series of intense landfalling storms that occurred during the record-setting 2005 hurricane season. However, the ability to understand—and therefore the ability to predict—tropical cyclogenesis remains limited, despite recent field studies and numerical experiments that have led to the development of conceptual models describing pathways for tropical vortex initiation. This study addresses the issue of TC spinup by developing a dynamically based classification scheme built on a diagnosis of North Atlantic hurricanes between 1948 and 2004. A pair of metrics is presented that describes TC development from the perspective of external forcings in the local environment. These discriminants are indicative of quasigeostrophic forcing for ascent and lower-level baroclinicity and are computed for the 36 h leading up to TC initiation. A latent trajectory model is used to classify the evolution of the metrics for 496 storms, and a physical synthesis of the results yields six identifiable categories of tropical cyclogenesis events. The nonbaroclinic category accounts for 40% of Atlantic TCs, while events displaying perturbations from this archetype make up the remaining 60% of storms. A geographical clustering of the groups suggests that the classification scheme is identifying fundamentally different categories of tropical cyclogenesis. Moreover, significant differences between the postinitiation attributes of the classes indicate that the evolution of TCs may be sensitive to the pathway taken during development.
Commitment and compatibility: Teachers' perspectives on the implementation of an effective school-based, peer-led smoking intervention
Authors: Audrey Suzanne , Holliday Jo , Campbell Rona 
Published: May 2008

Objective Although current UK policy argues that schools have a key role in raising health standards, emphasis on the core curriculum restricts teachers' opportunities to undertake health promotion activities. The challenge is to design effective health promotion interventions that minimize pressures on teaching staff and curriculum space. Here we consider teachers' perspectives of an effective peer-led, school-based smoking intervention, implemented by external trainers. Design The intervention, during which influential Year 8 students identified through a whole-year peer nomination process were trained to reduce smoking uptake through informal interactions with students in their year group, was evaluated by a pragmatic randomized controlled trial (ASSIST: A Stop Smoking In Schools Trial). An integral process evaluation examined the context, implementation and receipt of the intervention. Setting Thirty secondary schools in south-east Wales and the west of England. Methods Teachers in all intervention schools completed questionnaires at key stages of the intervention. Semi-structured interviews were undertaken in four schools at baseline and immediately post-intervention. The method of constant comparison, derived from grounded theory, was used throughout the analysis. Results The intervention was successfully implemented in a wide range of schools; recruitment and retention rates were good; and outcome data showed a reduction in smoking levels. Some teachers expressed concern about the participation of challenging students, external trainers setting standards of discipline, and communication over timetabling. Conclusion Overall, teachers showed commitment to the ASSIST intervention and felt it was compatible with the Year 8 curriculum. If implemented more widely, the importance of peer nomination should be stressed.
Learning motivational interviewing: Exploring primary health care nurses' training and counselling experiences
Authors: Söderlund Lena Lindhe , Nilsen Per , Kristensson Margareta 
Published: May 2008

Objective This article explores the training and counselling experiences of 20 nurses, aiming to identify key elements in the process of learning and applying motivational interviewing (MI) counselling skills with adherence to protocols. Setting/method The nurses were recruited from 10 primary health care units in Östergötland, Sweden. The study was carried out after the nurses had been practicing MI counselling in daily clinical work for about a year. Data were collected by means of semi-structured interviews, based on an interview guide, which contained questions on factors that past research has identified as important for effective training in and practicing of MI. Results The interviews revealed several key factors for successfully learning and applying MI. Extensive training and close integration of training and practice were seen as crucial aspects to effective learning of MI skills. A barrier to satisfactory learning of the MI counselling skills was the difficulty of adjusting to the new way of thinking required when practicing this technique, since it contrasted with the authoritarian expert approach that the nurses were used to. Another difficulty was achieving effective communication with patients who were unwilling to accept responsibility for their own health. Conclusion Effective learning and application of MI skills with adherence to protocols is fraught with many problems, requiring a considerable amount of time and effort for practice as well as the adoption of a new frame of mind with regard to the health care providers' relationships with the patients.