bluuebunny/crossref_metadata_2025 huggingface dataset:
The Effect of Photofrin on DNA Strand Breaks and Base Oxidation in HaCaT Keratinocytes: A Comet Assay Study¶
Authors: Woods J. A. , Traynor N. J. , Brancaleon L. , Moseley H.
Published: January 2011

Photodynamic therapy (PDT) kills cells via the production of singlet oxygen and other reactive oxygen species. PDT causes chromosomal damage and mutation to cultured cells. However, DNA damage does not contribute to the phototoxic effect. To study the effect of Photofrin‐PDT‐induced DNA damage, we used the comet assay in combination with endonuclease III and formamidopyrimidine DNA glycosylase and a human keratinocyte cell line to investigate photogenotoxicity and its prevention by tocopherol (TOC). This study shows that PDT induced DNA damage in HaCaT cells at doses allowing cells to survive 7 days after irradiation. α‐TOC did not prevent the acute cell lysis caused by Photofrin‐PDT but did prevent Photofrin‐PDT‐induced DNA damage. However, the concentration of TOC that conferred protection (100 μM) was higher than is detected in human serum. Base oxidation was also measured using the comet assay. Although TOC could prevent frank DNA strand breaks caused by PDT, it was unable to decrease the level of base oxidation as revealed by enzymesensitive sites. It is suggested that the potential genotoxic risk from laser‐PDT could be low, and that topical α‐TOC at a high concentration may be useful in preventing some types of DNA damage without preventing acute photolysis after Photofrin‐PDT.
Competitive and Collaborative Quality and Warranty Management in Supply Chains
Authors: Dai Yue , Zhou Sean X. , Xu Yifan
Published: January 2011

Product quality and product warranty coverage are two important and closely related operational decisions. A longer warranty protection period can boost sales, but it may also result in dramatically increased warranty cost, if product quality is poor. To investigate how these two decisions interact with each other and influence supply chain performance, we develop a single‐period model with a supplier that provides a product to an original equipment manufacturer, which in turn sells it to customers. Customer demand is random and affected by the length of the product warranty period. Warranty costs are incurred by both the supplier and the manufacturer. We analyze two different scenarios based on which party sets the warranty period: manufacturer warranty and supplier warranty. Product quality is controlled by the supplier, and the manufacturer determines the ordering quantity. We analyze these decentralized systems and provide the structural properties of the equilibrium strategies. We also compare the results of centralized and decentralized systems and identify the conditions under which one system provides a longer warranty and better product quality than the other. Our numerical study further shows that, in decentralized settings, when the warranty period is determined by the firm sharing the larger proportion of total warranty costs, the supply chain can achieve greater system‐wide profit. Both parties can therefore benefit from properly delegating the warranty decision and sharing the resulting additional profit. We further design a supplier‐development and buy‐back contract for coordinating decentralized supply chains. Several extensions are also discussed.
Optimal Design of a Pharmaceutical Price–Volume Agreement Under Asymmetric Information About Expected Market Size
Authors: Zhang Hui , Zaric Gregory S. , Huang Tao
Published: January 2011

Price–volume agreements are commonly negotiated between drug manufacturers and third‐party payers for drugs. In one form a drug manufacturer pays a rebate to the payer on a portion of sales in excess of a specified threshold. We examine the optimal design of such an agreement under complete and asymmetric information about demand. We consider two types of uncertainty: information asymmetry, defined as the payer's uncertainty about mean demand; and market uncertainty, defined as both parties' uncertainty about true demand. We investigate the optimal contract design in the presence of asymmetric information. We find that an incentive compatible contract always exists; that the optimal price is decreasing in expected market size, while the rebate may be increasing or decreasing in expected market size; that the optimal contract for a manufacturer with the highest possible demand would include no rebate; and, in a special case, if the average reservation profit is non‐decreasing in expected market size, then the optimal contract includes no rebates for all manufacturers. Our analysis suggests that price–volume agreements with a rebate rate of 100% are not likely to be optimal if payers have the ability to negotiate prices as part of the agreement.
The Surgical Scheduling Problem: Current Research and Future Opportunities
Authors: May Jerrold H. , Spangler William E. , Strum David P. , Vargas Luis G.
Published: January 2011

This paper reviews the general problem of surgical scheduling. We organize the literature based on the time frame or planning horizon of the schedule into six categories: capacity planning, process reengineering/redesign, the surgical services portfolio, procedure duration estimation, schedule construction, and schedule execution, monitoring, and control. We survey past work and suggest topics for potential future research in each of those areas.
Motility of the equine gastrointestinal tract: Physiology and pharmacotherapy
Authors: Wong D. M. , Davis J. L. , White N. A.
Published: January 2011

Normal gastrointestinal (GI) motility patterns are necessary to maintain transit of ingesta and to facilitate digestion and absorption of nutrients. Disorders of the equine GI tract are frequently encountered by the equine practitioner and these disorders are often associated with an interruption in normal intestinal motility patterns, thus complicating treatment of the primary disease. Consequently, numerous treatments have been investigated in horses to facilitate the return of normal intestinal motility. The purpose of this article is to provide a brief review of the anatomy and physiology of the GI tract in the horse and review medications available to the equine veterinarian that may potentially promote intestinal motility.
A Survey of Fitness-for-Service Trends in Industry
Authors: Holtam C. M. , Baxter D. P. , Ashcroft I. A. , Thomson R. C.
Published: January 2011

In 2002, TWI Ltd. carried out a questionnaire-based survey of “user experience of plant life management practices,” to gain a better understanding of the reality of plant life management and the needs of plant operators [Iravani and Speck, 2002, “Industry Survey of Risk Based Life Management Practices and Their Relationship to Fitness-for-Service Assessment,” TWI Report No. 13032/5/02]. In 2003, the European fitness-for-service network reported the results of their survey on “current application and future requirements for European fitness-for-service (FFS) technology” [Filiou et al. 2003, “Survey of Current Application and Future Requirements for European Fitness-for-Service Technology,” Technical Report No. FITNET/TR2/03, FITNET Consortium]. In 2006, the management of aging plant became a regulatory hot topic in the UK with a health and safety executive document on the subject being released [Health and Safety Executive, 2006, “Plant Ageing: Management of Equipment Containing Hazardous Fluids or Pressure,” RR509]. Considering also the recent release of the new API/ASME joint FFS standard [2007, API 579-1/ASME FFS-1, Fitness-For-Service, 1st ed., The American Petroleum Institute and the American Society of Mechanical Engineers, Washington, DC], TWI Ltd. decided 2007 was the ideal time to carry out an updated industry survey to assess how developments such as these might affect plant life management practices in different industry sectors across the world. The aims of this survey were to gain an insight into current FFS trends across several industry sectors and how these may change in the future. Information was gathered as to how different companies handle their FFS activities, both in terms of the types of flaw they assess and the complexity of the assessments they carry out. The survey also investigated how safety regulating authorities view FFS activities and whether or not they accept the results as the basis for plant integrity management decisions. Closely related to this is whether there is a need for better regulation of FFS activities, FFS training, or, indeed, whether FFS qualifications should be introduced. This paper presents the results of the online industry survey and draws pragmatic conclusions that will be of interest to all those involved with FFS activities, from inspectors to researchers and from engineers to insurers.
The Effects of Residual Stress Distribution and Component Geometry on the Stress Intensity Factor of Surface Cracks
Authors: Miyazaki Katsumasa , Mochizuki Masahito
Published: January 2011

The stress intensity factor estimated by the appropriate modeling of components is essential for the evaluation of crack growth behavior in stress corrosion cracking. For the appropriate modeling of a welded component with a crack, it is important to understand the effects of residual stress distribution and the geometry of the component on the stress intensity factor of the surface crack. In this study, the stress intensity factors of surface cracks under two assumed residual stress fields were calculated. As residual stress field, a bending type stress field (tension-compression) and a self-equilibrating stress field (tension-compression-tension) through the thickness were assumed, respectively. The geometries of the components were plate and piping. The assumed surface cracks for those evaluations were a long crack in the surface direction and a semi-elliptical surface crack. In addition, crack growth evaluations were conducted to clarify the effects of residual stress distribution and the geometry of the component. Here, the crack growth evaluation means simulating increments of crack depth and length using crack growth properties and stress intensity factors. The effects of residual stress distribution and component geometry on the stress intensity factor of surface cracks and the appropriate modeling of cracked components are discussed by comparing the stress intensity factors and the crack growth evaluations for surface cracks under residual stress fields.
An Egg-Adult Association, Gender, and Reproduction in Pterosaurs
Authors: Lü Junchang , Unwin David M. , Deeming D. Charles , Jin Xingsheng , Liu Yongqing , Ji Qiang
Published: January 2011

A pterosaur fossil that includes a small, soft-shelled egg indicates a reproductive strategy like that of crocodilians.
Quantum Criticality Without Tuning in the Mixed Valence Compound β-YbAlB
4
Authors: Matsumoto Yosuke , Nakatsuji Satoru , Kuga Kentaro , Karaki Yoshitomo , Horie Naoki , Shimura Yasuyuki , Sakakibara Toshiro , Nevidomskyy Andriy H. , Coleman Piers
Published: January 2011

A quantum phase transition is observed in a stoichiometric compound at ambient pressure and in zero magnetic field.
Increasing Solar Absorption for Photocatalysis with Black Hydrogenated Titanium Dioxide Nanocrystals
Authors: Chen Xiaobo , Liu Lei , Yu Peter Y. , Mao Samuel S.
Published: January 2011

An amorphous surface layer on titantium dioxide nanoparticles creates electronic states that allow longer-wavelength photoexcitation.
The Gut's
Clostridium
Cocktail
Authors: Barnes Michael J. , Powrie Fiona
Published: January 2011

Certain indigenous bacteria drive the expansion of regulatory T cells in the mammalian gastrointestinal tract that control inflammation and disease.
ESP Paper Rekindles Discussion About Statistics
Authors: Miller Greg
Published: January 2011

A paper on extrasensory perception that is in press at a top psychology journal has rekindled a long-running debate about whether the statistical tools commonly used in psychology—and most other areas of science—too often lead researchers astray.
Scrambling to Close the Isotope Gap
Authors: Service Robert F.
Published: January 2011

New technologies are needed urgently to assure the continued supply of radioactive materials essential for diagnosing and treating millions of patients around the world.
Turtles Are Not Just Drifters
Authors: Pennisi Elizabeth
Published: January 2011

Seven sea turtles with solar-powered satellite transmitters attached to their backs have demonstrated that they do more than simply follow the ocean currents as biologists had long assumed, researchers reported at the meeting.
Evaluation of the Immunogenicity and Biological Activity of the
Citrobacter freundii
Vi-CRM
197
Conjugate as a Vaccine for
Salmonella enterica
Serovar Typhi
Authors: Rondini Simona , Micoli Francesca , Lanzilao Luisa , Hale Christine , Saul Allan J. , Martin Laura B.
Published: January 2011

Typhoid fever remains a major health problem in developing countries. Young children are at high risk, and a vaccine effective for this age group is urgently needed. Purified capsular polysaccharide from
Salmonella enterica
serovar Typhi (Vi) is licensed as a vaccine, providing 50 to 70% protection in individuals older than 5 years. However, this vaccine is ineffective in infants. Vi conjugated to a carrier protein (i.e., an exoprotein A mutant from
Pseudomonas aeruginosa
[rEPA]) is highly immunogenic, provides long-term protection, and shows more than 90% protective efficacy in children 2 to 5 years old. Here, we describe an alternative glycoconjugate vaccine for
S
. Typhi, Vi-CRM
197
, where Vi was obtained from
Citrobacter freundii
WR7011 and CRM
197
, the mutant diphtheria toxin protein, was used as the carrier. We investigated the optimization of growth conditions for Vi production from
C. freundii
WR7011 and the immunogenicity of Vi-CRM
197
conjugates in mice. The optimal saccharide/protein ratio of the glycoconjugates was identified for the best antibody production. We also demonstrated the ability of this new vaccine to protect mice against challenge with Vi-positive
Salmonella enterica
serovar Typhimurium.
Mucosal Immunologic Responses in Cholera Patients in Bangladesh
Authors: Uddin Taher , Harris Jason B. , Bhuiyan Taufiqur Rahman , Shirin Tahmina , Uddin Muhammad Ikhtear , Khan Ashraful Islam , Chowdhury Fahima , LaRocque Regina C. , Alam Nur Haque , Ryan Edward T. , Calderwood Stephen B. , Qadri Firdausi
Published: January 2011

Vibrio cholerae
O1 causes dehydrating diarrhea with a high mortality rate if untreated. The infection also elicits long-term protective immunity. Since
V. cholerae
is noninvasive, mucosal immunity is likely important for protection. In this study, we compared humoral immune responses in the duodenal mucosa and blood of cholera patients at different time points after the onset of disease and compared them with those of healthy controls (HCs). Immune responses to lipopolysaccharide (LPS) and the recombinant cholera toxin B subunit (rCTB) were assessed by enzyme-linked immunosorbent assay (ELISA) and enzyme-linked immunospot (ELISPOT) assay. Significant increases in
V. cholerae
LPS-specific IgA and IgG antibody levels were seen in duodenal extracts on day 30, but the levels decreased to baseline by day 180; plasma
V. cholerae
LPS-specific IgA levels remained elevated longer. Levels of mucosal CTB antibodies also peaked on day 30, but the increase reached statistical significance only for IgG. A significant correlation was found between the CTB antibody-secreting cell (ASC) response in the circulatory system on day 7 and subsequent CTB-specific IgA levels in duodenal extracts on day 30 and the numbers of CTB-specific IgA ASCs in duodenal tissues on day 180. The proportion (0.07%) of mucosal
V. cholerae
LPS IgA ASCs peaked on day 30 and remained elevated through day 180 compared to that of HCs (
P
= 0.03). These results suggest that protective immunity against
V. cholerae
is not likely mediated by the constitutive secretion of antibodies at the mucosal surface; our results are consistent with those of other studies that suggest instead that anamnestic immune responses of mucosal lymphocytes may play a major role in protection against cholera.
Identification of Human T-Cell Responses to Mycobacterium tuberculosis Resuscitation-Promoting Factors in Long-Term Latently Infected Individuals
Authors: Commandeur Susanna , van Meijgaarden Krista E. , Lin May Young , Franken Kees L. M. C. , Friggen Annemieke H. , Drijfhout Jan Wouter , Oftung Fredrik , Korsvold Gro Ellen , Geluk Annemieke , Ottenhoff Tom H. M.
Published: January 2011

The
Mycobacterium bovis
BCG vaccine is the only tuberculosis (TB) vaccine available, yet it provides limited protection against pulmonary TB in adults and fails to protect against TB reactivation. We hypothesized that immunity against
Mycobacterium tuberculosis
“resuscitation-promoting factors” (Rpfs), which are small bacterial proteins that promote proliferation of dormant mycobacteria, may be relevant in the human immune response to
M. tuberculosis
. In previous unpublished work, we found that Rpfs Rv0867c and Rv2389c induced gamma interferon (IFN-γ) production in the blood of TB patients' healthy household contacts in several different African populations. Here we examine these two dominant Rpf antigens in more detail and define the nature of the responding T-cell subsets. Multiparameter cytokine profiling showed that Rv2389c and, to a lesser extent, Rv0867c were recognized by mycobacterium-responsive healthy Dutch individuals; peptide-scanning revealed several epitopes, including a single immunodominant epitope in Rv2389c. Rv0867c and, to a lesser extent, Rv2389c Rpf-specific T-cell responses were maintained for decades in long-term
M. tuberculosis
nonprogressors. Prominent Rv0867c-specific double- and single-cytokine-producing CD8
+
T-cell subset responses were found, including a large population of CD8
+
effector memory and effector T-cell subsets. We conclude that
M. tuberculosis
Rpf antigens are important targets in the human immune response to
M. tuberculosis
and represent interesting TB vaccine candidate antigens.
Persistence of a Positive (1,3)-β-
d
-Glucan Test after Clearance of Candidemia in Hematopoietic Stem Cell Transplant Recipients
Authors: Mikulska M. , Furfaro E. , Del Bono V. , Gualandi F. , Van Lint M. T. , Miletich F. , Bacigalupo A. , Viscoli C.
Published: January 2011

In 6 hematopoietic stem cell transplant (HSCT) recipients with candidemia, the (1,3)-β-
d
-glucan (BG) test was positive a median of 2.5 days after a positive blood culture. Only in 1 patient did BG positivity precede positive blood cultures. BG concentrations decreased in patients with clinical response, but positive BG results persisted long after blood cultures became sterile (median, 48 days).
ThertxAToxin Gene of Kingella kingae: a Pertinent Target for Molecular Diagnosis of Osteoarticular Infections
Authors: Lehours Philippe , Freydière Anne-Marie , Richer Olivier , Burucoa Christophe , Boisset Sandrine , Lanotte Philippe , Prère Marie Françoise , Ferroni Agnès , Lafuente Christine , Vandenesch Francois , Mégraud Francis , Ménard Armelle
Published: January 2011

Kingella kingaeis an emerging osteoarticular pathogen in young children. Its isolation by traditional culture methods remains difficult, underscoring the need to implement other diagnostic methods for its detection and identification, such as nucleic acid amplification tests. Although the genome of this bacterium has not yet been sequenced, a toxin named RTX has been identified. The goal of this study was to develop sensitive, specific, and rapid molecular methods based on thertxAtoxin gene sequence to diagnose this infection. Two real-time PCR assays (SYBR green and TaqMan chemistries) targeting this gene are reported. Sensitivity and specificity were first evaluated successfully with 67 strains: 31Kingella kingaeisolates and 36 strains from other bacterial species. Then, 52 clinical specimens positive or negative by culture and/or PCR (16S rRNA andcpn60genes) were tested with these assays. A nested PCR assay with subsequent sequencing was also developed to confirm the presence ofKingella kingaeisolates in these clinical specimens. The results obtained demonstrate that these assays are accurate for the diagnosis ofKingella kingaeinfection.
Detection of Hepatitis C Virus and Antibodies in Postmortem Blood and Bloodstains
Authors: Takasaka Tomokazu , Itoh Yoshito , Kaneko Hiroto , Ikegaya Hiroshi
Published: January 2011

To evaluate the risk of accidental hepatitis C virus (HCV) infection, we examined whether anti-HCV antibodies and HCV RNA were detectable in HCV-infected blood samples from living donors, cadavers, and bloodstains. We showed that even after blood has left the body for several days, anti-HCV antibodies and HCV RNA may persist in it.
Colorimetric-Plate Method for Rapid Disk Diffusion Susceptibility Testing of Escherichia coli
Authors: Sener Sehnaz , Acuner Ibrahim Cagatay , Bek Yuksel , Durupinar Belma
Published: January 2011

Here, we report a laboratory-developed colorimetric-plate method for rapid disk diffusion susceptibility testing of
Escherichia coli
. One hundred isolates were evaluated. Categorical agreement between the colorimetric plate and the standard disk diffusion method was 99%. Mean time to results was 7.07 h (95% confidence interval, 5.96 to 8.19).
Outbreak of Infections by Hepatitis B Virus Genotype A and Transmission of Genetic Drug Resistance in Patients Coinfected with HIV-1 in Japan
Authors: Fujisaki Seiichiro , Yokomaku Yoshiyuki , Shiino Teiichiro , Koibuchi Tomohiko , Hattori Junko , Ibe Shiro , Iwatani Yasumasa , Iwamoto Aikichi , Shirasaka Takuma , Hamaguchi Motohiro , Sugiura Wataru
Published: January 2011

The major routes of hepatitis B virus (HBV) infection in Japan has been mother-to-child transmission (MTCT) and blood transfusion. However, HBV cases transmitted through sexual contact are increasing, especially among HIV-1-seropositive patients. To understand the molecular epidemiology of HBV in HBV/HIV-1 coinfection, we analyzed HBV genotypes and HIV-1 subtypes in HBV/HIV-1-coinfected patients at Nagoya Medical Center from 2003 to 2007. Among 394 HIV-1-infected Japanese men having sex with men (MSM) who were newly diagnosed during the study period, 31 (7.9%) tested positive for the hepatitis B virus surface antigen. HBV sequence analyses were successful in 26 cases, with 21 (80.7%) and 5 (19.3%) cases determined as genotypes A and C, respectively. Our finding that HBV genotype A was dominant in HIV-1-seropositive patients alerts clinicians to an alternative outbreak of HBV genotype A in the HIV-1-infected MSM population and a shift in HBV genotype from C to A in Japan. The narrow genetic diversity in genotype A cases suggests that genotype A has been recently introduced into the MSM population and that sexual contacts among MSM were more active than speculated from HIV-1 tree analyses. In addition, we found a lamivudine resistance mutation in one naïve case, suggesting a risk of drug-resistant HBV transmission. As genotype A infection has a higher risk than infection with other genotypes for individuals to become HBV carriers, prevention programs are urgently needed for the target population.
Direct Genotyping of Toxoplasma gondii in Ocular Fluid Samples from 20 Patients with Ocular Toxoplasmosis: Predominance of Type II in France
Authors: Fekkar A. , Ajzenberg D. , Bodaghi B. , Touafek F. , Le Hoang P. , Delmas J. , Robert P. Y. , Dardé M. L. , Mazier D. , Paris L.
Published: January 2011

We report the direct genotyping analysis of
Toxoplasma gondii
in ocular samples collected from 20 patients, as well as associated clinical and epidemiological data. This work was aimed at better understanding the impact of genotypes of
Toxoplasma gondii
strains on toxoplasmic retinochoroiditis. For this purpose, we studied the aqueous humor (AH) or vitreous humor (VH) of 20 patients presenting with ocular toxoplasmosis (OT) in 2 hospitals in France. Genetic characterization was obtained with microsatellite markers in a multiplex PCR assay. In contrast to the results of previous studies, we found no association between atypical
Toxoplasma gondii
genotypes and the occurrence of OT. Considering the local epidemiological data, our OT patients seemed to be infected more frequently by ordinary type II strains found in the environment. In conclusion, direct genotyping of
Toxoplasma gondii
strains from aqueous or vitreous humor showed a predominance of the type II genotype in ocular toxoplasmosis; this may be due to a high exposure rate of this genotype in humans.
Laboratory Diagnosis, Epidemiology, and Clinical Outcomes of Pandemic Influenza A and Community Respiratory Viral Infections in Southern Brazil
Authors: Raboni Sonia M. , Stella Vanessa , Cruz Cristina R. , França João B. , Moreira Suzana , Gonçalves Lili , Nogueira Meri B. , Vidal Luine R. , Almeida Sergio M. , Debur Maria C. , Carraro Hipolito , Duarte dos Santos Claudia N.
Published: January 2011

Community respiratory viruses (CRVs) are commonly associated with seasonal infections. They have been associated with higher morbidity and mortality among children, elderly individuals, and immunosuppressed patients. In April 2009, the circulation of a new influenza A virus (FLUA H1N1v) was responsible for the first influenza pandemic of this century. We report the clinical and epidemiological profiles of inpatients infected with CRVs or with FLUA H1N1v at a tertiary care hospital in southern Brazil. In addition, we used these profiles to evaluate survivor and nonsurvivor patients infected with FLUA H1N1v. Multiplex reverse transcription-PCR (RT-PCR) and real time RT-PCR were used to detect viruses in inpatients with respiratory infections. Record data from all patients were reviewed. A total of 171 patients were examined over a period of 16 weeks. Of these, 39% were positive for FLUA H1N1v, 36% were positive for CRVs, and 25% were negative. For the FLUA H1N1v- and CRV-infected patients, epidemiological data regarding median age (30 and 1.5 years), myalgia (44% and 13%), need for mechanical ventilation (44% and 9%), and mortality (35% and 9%) were statistically different. In a multivariate analysis comparing survivor and nonsurvivor patients infected with influenza A virus H1N1, median age and creatine phosphokinase levels were significantly associated with a severe outcome. Seasonal respiratory infections are a continuing concern. Our results highlight the importance of studies on the prevalence and severity of these infections and that investments in programs of clinical and laboratory monitoring are essential to detect the appearance of new infective agents.
Development of a Cellular Assay System To Study the Genome Replication of High- and Low-Risk Mucosal and Cutaneous Human Papillomaviruses
Authors: Geimanen Jelizaveta , Isok-Paas Helen , Pipitch Regina , Salk Kristiina , Laos Triin , Orav Marit , Reinson Tormi , Ustav Mart , Ustav Mart , Ustav Ene
Published: January 2011

We found that recircularized high-risk (type 16 and 18) and low-risk mucosal (type 6b and 11) and cutaneous (type 5 and 8) human papillomavirus (HPV) genomes replicate readily when delivered into U2OS cells by electroporation. The replication efficiency is dependent on the amount of input HPV DNA and can be followed for more than 3 weeks in proliferating cell culture without selection. Cotransfection of recircularized HPV genomes with a linear G418 resistance marker plasmid has allowed subcloning of cell lines, which, in a majority of cases, carry multicopy episomal HPV DNA. Analysis of the HPV DNA status in these established cell lines showed that HPV genomes exist in these cells as stable extrachromosomal oligomers. When the cell lines were cultivated as confluent cultures, a 3- to 10-fold amplification of the HPV genomes per cell was induced. Two-dimensional (2D) agarose gel electrophoresis confirmed amplification of mono- and oligomeric HPV genomes in these confluent cell cultures. Amplification occurred as a result of the initiation of semiconservative two-dimensional replication from one active origin in the HPV oligomer. Our data suggest that the system described here might be a valuable, cost-effective, and efficient tool for use in HPV DNA replication studies, as well as for the design of cell-based assays to identify potential inhibitors of all stages of HPV genome replication.
Requirement for the Amino-Terminal Domain of Sindbis Virus nsP4 during Virus Infection
Authors: Rupp Jonathan C. , Jundt Natasha , Hardy Richard W.
Published: January 2011

The Sindbis virus RNA-dependent RNA polymerase nsP4 possesses an amino-terminal region that is unique to alphaviruses and is predicted to be disordered. To determine the importance of this region during alphavirus replication, 29 mutations were introduced, and resultant viruses were assessed for growth defects. Three small plaque mutants, D41A, G83L, and the triple mutant GPG
(8-10)
VAV, had defects in subgenome synthesis, minus-strand synthesis, and overall levels of viral RNA synthesis, respectively. Large plaque viruses were selected following passage in BHK-21 cells, and the genomes of these were sequenced. Suppressor mutations in nsP1, nsP2, and nsP3 that restored viral RNA synthesis were identified. An nsP2 change from M282 to L and an nsP3 change from H99 to N corrected the D41A-induced defect in subgenomic RNA synthesis. Three changes in nsP1, I351 to V, I388 to V, or the previously identified change, N374 to H (C. L. Fata, S. G. Sawicki, and D. L. Sawicki, J. Virol. 76:8641-8649, 2002), suppressed the minus-strand synthetic defect. A direct reversion back to G at position 8 reduced the RNA synthesis defect of the GPG
(8-10)
VAV virus. These results imply that nsP4's amino-terminal domain participates in distinct interactions with other nsPs in the context of differentially functioning RNA synthetic complexes, and flexibility in this domain is important for viral RNA synthesis. Additionally, the inability of the mutant viruses to efficiently inhibit host protein synthesis suggests a role for nsP4 in the regulation of host cell gene expression.
Prion Propagation in Cells Expressing PrP Glycosylation Mutants
Authors: Salamat Muhammad K. , Dron Michel , Chapuis Jérôme , Langevin Christelle , Laude Hubert
Published: January 2011

Infection by prions involves conversion of a host-encoded cell surface protein (PrP
C
) to a disease-related isoform (PrP
Sc
). PrP
C
carries two glycosylation sites variably occupied by complex N-glycans, which have been suggested by previous studies to influence the susceptibility to these diseases and to determine characteristics of prion strains. We used the Rov cell system, which is susceptible to sheep prions, to generate a series of PrP
C
glycosylation mutants with mutations at one or both attachment sites. We examined their subcellular trafficking and ability to convert into PrP
Sc
and to sustain stable prion propagation in the absence of wild-type PrP. The susceptibility to infection of mutants monoglycosylated at either site differed dramatically depending on the amino acid substitution. Aglycosylated double mutants showed overaccumulation in the Golgi compartment and failed to be infected. Introduction of an ectopic glycosylation site near the N terminus fully restored cell surface expression of PrP but not convertibility into PrP
Sc
, while PrP
C
with three glycosylation sites conferred cell permissiveness to infection similarly to the wild type. In contrast, predominantly aglycosylated molecules with nonmutated N-glycosylation sequons, produced in cells expressing glycosylphosphatidylinositol-anchorless PrP
C
, were able to form infectious PrP
Sc
. Together our findings suggest that glycosylation is important for efficient trafficking of anchored PrP to the cell surface and sustained prion propagation. However, properly trafficked glycosylation mutants were not necessarily prone to conversion, thus making it difficult in such studies to discern whether the amino acid changes or glycan chain removal most influences the permissiveness to prion infection.
The V1V2 Domain and an N-Linked Glycosylation Site in the V3 Loop of the HIV-1 Envelope Glycoprotein Modulate Neutralization Sensitivity to the Human Broadly Neutralizing Antibody 2G12
Authors: Chaillon Antoine , Braibant Martine , Moreau Thierry , Thenin Suzie , Moreau Alain , Autran Brigitte , Barin Francis
Published: January 2011

The broadly neutralizing human monoclonal antibody 2G12 binds to a carbohydrate-dependent epitope involving three major potential N-linked glycosylation sites (PNGS) of gp120 (N295, N332, and N392). Through analysis of the sensitivity to 2G12 of pseudotyped viruses carrying envelope proteins from HIV-1 clade B-infected long-term nonprogressors, we selected two naturally occurring
env
clones with opposite sensitivities to
2G12
, albeit harboring the 3 particular PNGS known to be essential for 2G12 binding (N295, N332, and N392). The resistant clone presented a long and potentially heavily glycosylated V1V2 loop and an additional PNGS (N302) in the V3 loop. The sensitive clone harbored a short V1V2 loop and lacked the PNGS at N302. We created chimeric envelope genes by swapping the V1V2 domains of the two
env
clones. The influence of N302 on 2G12 sensitivity was assessed by PCR-based site-directed mutagenesis. Both the exchange of the V1V2 domain and the introduction of the PNGS at N302 on the 2G12-sensitive clone induced a significant decrease in sensitivity to 2G12. In contrast, the reverse V1V2 exchange and the removal of the PNGS at N302 on the 2G12-resistant clone increased sensitivity to 2G12, confirming the influence of these regions on 2G12 sensitivity. Our results, supported by a molecular-modeling study, suggest that both the V1V2 loop and an additional PNGS in V3 might limit access to the 2G12 epitope.
Expression of the Human Endogenous Retrovirus (HERV) Group HML-2/HERV-K Does Not Depend on Canonical Promoter Elements but Is Regulated by Transcription Factors Sp1 and Sp3
Authors: Fuchs Nina V. , Kraft Martin , Tondera Christiane , Hanschmann Kay-Martin , Löwer Johannes , Löwer Roswitha
Published: January 2011

After fixation in the human genome, human endogenous retroviruses (HERVs) are
bona fide
cellular genes despite their exogenous origin. To be able to spread within the germ line and the early embryo, the ancient retroviral promoters must have adapted to the requirements for expression in these cell types. We describe that in contrast to the case for current exogenous retroviruses, which replicate in specific somatic cells, the long terminal repeat (LTR) of the human endogenous retrovirus HERV-K acts as a TATA- and initiator element-independent promoter with a variable transcription start site. We present evidence that the HERV-K LTR is regulated by the transcription factors Sp1 and Sp3. Mutating specific GC boxes, which are binding sites for Sp proteins, and knocking down Sp1 and Sp3 by use of small interfering RNA (siRNA) significantly reduced the promoter activity. Binding of Sp1 and Sp3 to the promoter region was confirmed using electrophoretic mobility shift assays (EMSAs) and chromatin immunoprecipitation (ChIP). Our data explain why certain HERV-K proviruses have lost promoter competence. Since vertebrate promoters lacking canonical core promoter elements are common but poorly studied, understanding the HERV-K promoter not only will provide insight into the regulation of endogenous retroviruses but also can serve as a paradigm for understanding the regulation of this class of cellular genes.
Effect of anabolic steroid, IGF-1 and loading on expression of genes involved in collagen metabolism in bovine extensor tendon
Authors: Bhullar Sukhbir , Legerlotz Kirsten
Published: January 2011

Background

Tendon ruptures have been linked to anabolic steroid usage, suggesting pathological changes in tendon structure due to steroid intake. Anecdotal reports from athletes suggest a protective effect of GH on tendon, especially in those who use anabolic steroids.

Aim

To investigate how administration of insulin-like growth factor 1 (IGF-1), anabolic steroid and combination of the two affect the expression of genes involved in collagen metabolism.

Methods

Fascicles were harvested from bovine extensor tendons: n=4 to calculate optimal loading and n=8 to assess hormone plus optimal loading effect on eight genes involved in collagen metabolism. Total RNA was extracted and mRNA expression analysed by quantitative real-time reverse transcription-PCR, normalised to GAPDH and 18S ribosomal RNA±control (Con).

Results

Maximal collagen expression occurred at 6 h of light exercise, following 1 h of heavy loading. One tendon failed to have RNA extracted and was therefore removed from the study (n=7). IL-6 expression was significantly higher than control when exercised fascicles were exposed to: (1) anabolic steroid (normalised to: 18S; GAPDH; 18S & Con and GAPDH & Con); (2) IGF-1 (normalised to: GAPDH; 18S & Con and GAPDH & Con); (3) Dulbecco’s modified Eagle’s medium & PenStrep (normalised to: 18S & Con and GAPDH & Con) and (4) anabolic steroid & IGF-1 (normalised to: 18S & Con and GAPDH & Con).

Conclusion

The results of this study suggest that tendon is an IL-6 producing region during exercise which may also contribute to IL-6 increases in plasma during exercise.
Longitudinal development of physiological characteristics in elite young males
Authors: Hemmings Steph , Nevill Mary , Morris John , Barrett Laura
Published: January 2011

Background

Cross-sectional studies examining training effects on development of performance variables have been confounded by growth and development changes. In order to examine the relative contribution of training, there was a need to collect ‘growth’ data longitudinally.

Aims and objectives

The purpose of this study was to examine age- and maturity-associated variation in longitudinal physiological characteristics development in elite and non-elite adolescent males.

Methods

Longitudinal measures of peak VO2, submaximal VO2, and power output in 11 elite, (13.7–17.8 years), and five non-elite males (13.1–17.6 years), over 2 or 3 consecutive years were examined. Maturity was assessed using Tanner’s (1962) indices of secondary sexual characteristics.

Results

Sum of skinfolds remained the same in the elite group yet increased in the non-elite. Peak VO2was greater in the elite males by 9.1 ml/kg/min, with no change in age. Oxygen uptake at 10.6 km/h declined by 1.2 ml/kg/min per year in each group. Percentage peak VO2at the same running speed was l2% lower in the elite and declined by 1.3% each year in both groups. Blood lactate concentration was 1.5 mmol/l lower in the elite males compared to the non-elite, however there was no decline with age. Peak and mean power output increased disproportionately in the elite group, with percentage fatigue increasing similarly.

Conclusion

Body fatness increases across adolescence in the untrained male. Peak VO2remains stable throughout adolescence but is characteristically higher in elites either as a result of strenuous training or genetic endowment. Running economy improves with age in both elite and non-elite but does not appear to be related to training status. Short-term power output shows a disproportionate increase with age in the elite male athlete compared to the untrained contemporary, which may have been influenced by differences in body composition between groups.
Variability of kinematic and kinetic gait data in ambulatory children with spastic cerebral palsy with and without fixed ankle-foot orthoses using 3d motion analysis: a quantitative prospective study
Authors: Mohammed U , Twycross-Lewis R , Timotijevic T , Woledge R , Bader D , Paterson M , Coggings D , Morrissey D
Published: January 2011

Background

Spastic cerebral palsy (SCP) is a common neurological disorder causing inadequate motor-control and functional gait pattern. Fixed ankle-foot orthoses (FAFOs) have become a widespread conservative therapy in SCP. Gait of these children exhibits a large degree of within-child variability but few studies have investigated this variability in terms of kinematics and kinetics and no studies address how this variability is affected with the use of FAFOs.

Objectives

To compare intrapatient variability of kinematic and kinetic gait parameters between a sample of ambulatory children with SCP and two healthy children with normal gait. The secondary aim was to assess if these variability profiles change in the SCP children as a result of FAFO application.

Methods

Four SCP and two normal ambulatory children, aged 5–15, were recruited and underwent active instrumented gait analysis over a 6 week period. Variability of a measure was defined as the SD of the measure within one child over several repeated gait trials.

Results

Variability of sagittal-plane pelvic, hip, knee and ankle range of motion (all p<0.01) and sagittal internal hip and knee extensor moments (both p<0.05) were shown to be consistently greater in SCP than that of age-matched children. AFO application reduces sagittal kinematic variability at the pelvis, knee and ankle (all p<0.05) and variability of sagittal hip and knee moments (both p<0.01).

Conclusions

Children with SCP exhibit significantly higher kinematic and kinetic variability compared to the normal population. FAFOs have the potential to reduce this variability and functionally improve gait. Future studies should utilise larger sample sizes and stricter inclusion criteria taking into account the differing clinical severities of spasticity, FAFO designs and patterns of CP involvement to ensure these are generalisable findings.
The differences in plantar loading between 3 positions related to the rugby scrum
Authors: Brown Sally , Twycross-Lewis R , Padhiar N
Published: January 2011

Objective

Foot injuries cause a significant absence from training and playing in the English rugby premiership. Pressure analysis gives information on how load is distributed, to give clinically relevant information this must be carried out in sports specific tasks. The aim of this study was to identify peak areas of pressure in the foot during three different positions related to the rugby scrum and their association to lower limb kinematics or stud formation.

Methods

Twenty-four male athletes were recruited from an English Premiership Rugby Club. An inner sole was inserted into the rugby boot to collect information on plantar pressure, the foot was divided into eight sections which were used to determine loading patterns. Three positions considered to be functionally relevant were studied, standing, engaged with a scrum machine and maximally pushing against the scrum machine. The Foot Posture Index, the weight bearing lunge test, first metatarsal extension and the number of studs were assessed.

Results

The medial forefoot showed the greatest load in the engaged and push positions (p<0.05). Foot Posture Index was negatively correlated to forefoot pressures in standing (p<0.05). Increase range of weight bearing lunge allowed for greater posterior lateral plantar loading during pushing (p<0.05). Stud number was positively correlated to medial plantar pressure in standing and pushing (p<0.05).

Conclusion

The substantial load on the medial forefoot in the rugby scrum suggests potential mechanisms for metatarsalphalangeal injury. Stud placement, foot posture index and range of weight bearing lunge can all influence plantar pressure. Future research should investigate mechanisms to reduce load in peak regions during the rugby scrum.
Are asymptomatic ultrasound abnormalities in the achilles tendon of elite soccer players risk factors for symptoms one year later? a longitudinal cohort study
Authors: Jhingan S , Perry M , O'Driscoll G , Ahmad M , Maffulli N , Morrissey D
Published: January 2011

Background

Achilles tendinopathy is common and can bring a sports career to a premature end. Identifying players at an increased risk of this debilitating condition could lead to better prevention.

Objectives

The primary aim was to compare asymptomatic elite soccer players with and without baseline ultrasound changes in terms of development of Achilles tendinopathy symptoms at one year follow-up. This study also investigated the effect that baseline tendon thickness had on development of symptoms.

Method

Using ultrasonography of the Achilles tendon, 18 initially asymptomatic elite soccer players in the top English league were examined in April 2009 and in May 2010. Symptom development during the 12 month follow-up period was assessed with an Achilles tendinopathy questionnaire on follow-up. Any Achilles pain during the follow-up period, of any duration or severity, was deemed to represent symptom development.

Results

No association between the existence of baseline asymptomatic ultrasound signs and development of Achilles tendinopathy symptoms in the following year was observed (χ2, 1.180 p=0.277). Baseline calcaneal insertion thickness was greater in tendons that experienced symptoms (p=0.035) in the following year compared to those that remained asymptomatic.

Conclusion

Baseline calcaneal insertion thickness was identified as a risk factor in the development of Achilles tendinopathy in elite soccer players. However, follow-up studies should aim to establish whether abnormal ultrasound signs and thickness measures over a longer period of time are significant markers of a presymptomatic stage.
An evaluation of the relationship between vitamin d status and quadriceps strength in patients with copd: a cross sectional study
Authors: Fenn J , Martineau A , Yee J Wai , Islam K , Griffiths C , Maffulli N , Morrissey D
Published: January 2011

Background

Quadriceps muscle weakness is a well-defined characteristic of chronic obstructive pulmonary disease (COPD). Vitamin D deficiency has been shown to be highly prevalent in COPD but its association with quadriceps strength in this group is unknown.

Objectives

To investigate the effects of Vitamin D status on quadriceps strength. To validate measurements of quadriceps strength by handheld dynamometer (HHD) against the gold standard isokinetic dynamometer (IKD) in a sub-population.

Methods

30 patients with COPD Gold Stage II and above were recruited. Quadriceps muscle strength was tested using the HHD in all subjects. Eight of the subjects were also tested using the IKD for validation purposes. Vitamin D status and a range of potentially confounding measures were assessed. A multivariate analysis was performed to determine which variables were associated with quadriceps strength.

Results

A very strong and positive correlation (r=0.92, 95%, p<0.0001), existed between the HHD and IKD measurements. Serum 25-hydroxyvitaminD was not associated with quadriceps strength (r=0.17, p=0.20). The male gender (β 36.7, 95% CI 14.0 to 59.4, p=0.002) and pack year history (β −0.15 95% CI −0.2 to −0.05, p=0.003) were independently associated with quadriceps strength.

Conclusions

The portable and inexpensive HHD is a valid method of testing quadriceps strength in patients with COPD. Serum 25-hydroxyvitaminD is not associated with quadriceps strength in patients with COPD, although male gender and a decrease in pack year history are significantly associated.