bluuebunny/crossref_metadata_2025 huggingface dataset:
Oxidative Stress and Oxidative Damage in Carcinogenesis
Authors: Klaunig James E. , Kamendulis Lisa M. , Hocevar Barbara A.
Published: December 2009

Carcinogenesis is a multistep process involving mutation and the subsequent selective clonal expansion of the mutated cell. Chemical and physical agents including those that induce reative oxygen species can induce and/or modulate this multistep process. Several modes of action by which carcinogens induce cancer have been identified, including through production of reactive oxygen species (ROS). Oxidative damage to cellular macromolecules can arise through overproduction of ROS and faulty antioxidant and/or DNA repair mechanisms. In addition, ROS can stimulate signal transduction pathways and lead to activation of key transcription factors such as Nrf2 and NF-κB. The resultant altered gene expression patterns evoked by ROS contribute to the carcinogenesis process. Recent evidence demonstrates an association between a number of single nucleotide polymorphisms (SNPs) in oxidative DNA repair genes and antioxidant genes with human cancer susceptibility. These aspects of ROS biology will be discussed in the context of their relationship to carcinogenesis.
On the Topology of Discrete Strategies
Authors: Erdmann Michael
Published: December 2009

In this paper we explore a topological perspective of planning in the presence of uncertainty, focusing on tasks specified by goal states in discrete spaces. We introduce strategy complexes . A strategy complex is the collection of all plans for attaining all goals in a given space. Plans are like jigsaw pieces. Understanding how the pieces fit together in a strategy complex reveals structure. That structure characterizes the inherent capabilities of an uncertain system. By adjusting the jigsaw pieces in a design loop, one can build systems with desired competencies. The paper draws on representations from combinatorial topology, Markov chains, and polyhedral cones. Triangulating between these three perspectives produces a topological language for describing concisely the capabilities of uncertain systems, analogous to the concepts of reachability and controllability in other disciplines. The major nouns in this language are topological spaces. Three key theorems illustrate the sentences in this language. (a) Goal attain-ability : There exists a strategy for attaining a particular goal from anywhere in a system if and only if the strategy complex of a slightly modified system is homotopic to a sphere. (b) Full controllability : A system can move between any two states despite control uncertainty precisely when its strategy complex is homotopic to a sphere of dimension two less than the number of states. (c) General structure : Any system’s strategy complex is homotopic to the product of a spherical part, modeling full controllability on subspaces, and a general part, modeling adversarial capabilities. This paper contains a number of additional results required as stepping stones, along with many examples. We provide algorithms for computing the key structures described. Finally, we show that some interesting questions are hard. For instance, it is NP-complete to determine the most precisely attainable goal of a system with perfect sensing, but uncertain control.
The Path-of-probability Algorithm for Steering and Feedback Control of Flexible Needles
Authors: Park Wooram , Yunfeng Wang  , Chirikjian Gregory S.
Published: December 2009

In this paper we develop a new framework for path planning of flexible needles with bevel tips. Based on a stochastic model of needle steering, the probability density function for the needle-tip pose is approximated as a Gaussian. The means and covariances are estimated using an error propagation algorithm which has second-order accuracy. Then we adapt the path-of-probability (POP) algorithm to path planning of flexible needles with bevel tips. We demonstrate how our planning algorithm can be used for feedback control of flexible needles. We also derive a closed-form solution for the port placement problem for finding good insertion locations for flexible needles in the case when there are no obstacles. Furthermore, we propose a new method using reference splines with the POP algorithm to solve the path planning problem for flexible needles in more general cases that include obstacles.
Consumer Attitudes Toward Fashion Counterfeits: Application of the Theory of Planned Behavior
Authors: Kim Hyejeong , Karpova Elena
Published: December 2009

This study examines consumer motivations that can explain attitudes toward purchasing fashion counterfeit goods and tests the underlying mechanism of intent to purchase fashion counterfeits based on the theory of planned behavior. A random sample of female college students (N = 336) participate in this study. Product appearance, past purchase behavior, value consciousness, and normative susceptibility are significant predictors of attitude toward buying fashion counterfeit goods. Attitude, subjective norm, and perceived behavioral control are significantly related to intent to purchase fashion counterfeit goods. This research extends the theory of planned behavior and tests two additional paths that significantly improve explanatory power of the theory and prediction of consumer intent to buy fashion counterfeit goods.
Vietnamese Diasporic Placemaking: An Ethnographic Moment in Uneven Geographic Development
Authors: Nguyên Thu Su'o'ng Thi
Published: December 2009

The article explores the ways “uneven geographical development” conditions and is conditioned by local placemaking practices. Guided by David Harvey’s work along with Henri Lefebvre’s three dimensions of spatial production— spatial practices, representations of space, and spaces of representation or the “spatial imaginary”—I look at the ways a diasporic community of Vietnamese teachers, students, and parents negotiate heritage language and culture within an urban public elementary school. I hope to illustrate how spatial production works on individuals in ways that produce both docile and self-determining bodies negotiating tensions between unity and difference. I argue that in confining our understanding of the spatial to static backdrops, we limit our abilities to imagine spaces of difference, geographies of desire, places of radical openness and possibility, and third spaces of political opportunity.
Actuation of Slender Thin-wall Anisotropic Open Cross-section Beams Based on Asymptotically Correct Vlasov Theory
Authors: Khouli F. , Griffiths J. , Afagh F.F. , Langlois R.G.
Published: December 2009

An asymptotically correct analysis of passive anisotropic thin-walled open cross-section beam-like structures using the variational asymptotic method (VAM) is extended to include embedded macro fiber composites. Application of the VAM to beam-like structures splits the problem into non-linear 1D theory along the selected beam reference line and linear 2D generalized 5 × 5 Vlasov theory augmented by a 5 × 1 actuation vector over the cross-section. The linear 2D cross-sectional theory is validated against the University of Michigan/variational beam sectional analysis 2D finite element software. The validation examples selected were based on practical cross-sectional geometry and material anisotropy under DC actuation voltage. Actuation-induced deformations predicted at the beam reference line are obtained using an intrinsic geometrically exact beam theory for open cross-sections. The predicted generalized deformations are compared with those obtained using the 3D finite element analysis software ANSYS Multiphysics, which further validates the extended theory. The analytical theory is shown to be straightforward to implement and efficient, yet sufficiently reliable to perform interdisciplinary studies and optimization of various engineering applications of such structures.
Item Response Theory Analyses of Parent and Teacher Ratings of the ADHD Symptoms for Recoded Dichotomous Scores
Authors: Gomez Rapson , Vance Alasdair , Gomez Andre
Published: December 2009

Objective: The two-parameter logistic model (2PLM) was used to evaluate the psychometric properties of the inattention (IA) and hyperactivity/impulsivity (HI) symptoms. Method: To accomplish this, parents and teachers completed the Disruptive Behavior Rating Scale (DBRS) for a group of 934 primary school-aged children. Results: The results for the discrimination parameters showed that all the IA and HI symptoms for both groups of respondents were generally good for discriminating those with and without IA and HI, respectively. For virtually all symptoms, their threshold values showed endorsement of the symptoms when the underlying trait levels were at least 1 to 1.5 SD above the mean. The item information function values for most symptoms indicated reasonable reliability from around the mean trait levels to moderately high trait levels. Conclusion: These findings indicate good discrimination and reliability for parent and teacher ratings of the DBRS for identifying children with relatively high levels of the ADHD symptoms. ( J. of Att. Dis. 2011; 15(4) 269-285)
Do psychosocial work environment factors measured with scales from the Copenhagen Psychosocial Questionnaire predict register-based sickness absence of 3 weeks or more in Denmark?
Authors: Rugulies Reiner , Aust Birgit , Pejtersen Jan Hyld
Published: December 2009

Aims: To analyse the predictive validity of 18 psychosocial work environment scales from the Copenhagen Psychosocial Questionnaire version II (COPSOQ II) with regard to risk of sickness absence. Methods: The study population consisted of 3188 wage earners (52% women) from a representative sample of Danish residents. Participants received the long version of the COPSOQ II in autumn and winter 2004—2005, including 18 psychosocial work environment scales from the domains ‘‘Demands at work’’, ‘‘Work organization and job contents’’, and ‘‘Interpersonal relations and leadership’’. The study endpoint was register-based sickness absence of 3 weeks or more in the 1-year period following completion of the COPSOQ II. Associations between COPSOQ scales at baseline and sickness absence at follow-up were analysed with Cox proportional hazards models, adjusted for age, gender, prevalence of a health problem at baseline, and occupational grade. Results: Sickness absence during follow-up was predicted by a one standard deviation increase on the scales of cognitive demands (hazard ratio (HR) 1.17, 95% confidence interval (CI) 1.00—1.37), emotional demands (HR 1.28, 95% CI 1.10—1.50), and role conflicts (HR 1.32, 95% CI 1.15—1.52). After applying adjustment for multiple testing, the effect of emotional demands and of role conflict remained statistically significant, but not the effect of cognitive demands. Conclusions: Selected psychosocial work environment factors from the COPSOQ predict register-based sickness absence in the Danish workforce.
The second version of the Copenhagen Psychosocial Questionnaire
Authors: Pejtersen Jan Hyld , Kristensen Tage Søndergård , Borg Vilhelm , Bjorner Jakob Bue
Published: December 2009

Aims: The aim of the present paper is to present the development of the second version of the Copenhagen Psychosocial Questionnaire (COPSOQ II). Methods: The development of COPSOQ II took place in five main steps: (1) We considered practical experience from the use of COPSOQ I, in particular feedback from workplace studies where the questionnaire had been used; (2) All scales concerning workplace factors in COPSOQ I were analyzed for differential item functioning (DIF) with regard to gender, age and occupational status; (3) A test version of COPSOQ II including new scales and items was developed and tested in a representative sample of working Danes between 20 and 59 years of age. In all, 3,517 Danish employees participated in the study. The overall response rate was 60.4%; (4) Based on psychometric analyses, the final questionnaire was developed; and (5) Criteria-related validity of the new scales was tested. Results: The development of COPSOQ II resulted in a questionnaire with 41 scales and 127 items. New scales on values at the workplace were introduced including scales on Trust, Justice and Social inclusiveness. Scales on Variation, Work pace, Recognition, Work-family conflicts and items on offensive behaviour were also added. New scales regarding health symptoms included: Burnout, Stress, Sleeping troubles and Depressive symptoms. In general, the new scales showed good criteria validity. All in all, 57% of the items of COPSOQ I were retained in COPSOQ II. Conclusions: The COPSOQ I concept has been further developed and new validated scales have been included.
Psychosocial work environment and intention to leave the nursing profession: Results from the longitudinal Chinese NEXT study
Authors: Li Jian , Fu Hua , Hu Yan , Shang Li , Wu Yinghui , Kristensen Tage Søndergård , Mueller Bernd Hans , Hasselhorn Hans Martin
Published: December 2009

Aims: A shortage of nurses happens not only in developed countries, but also in developing countries, such as in China, but the nurse turnover here makes the situation worse. Why do Chinese nurses want to leave the nursing profession? Our hypothesis is that unfavourable psychosocial work environment could predict nurses’ intention to leave (ITL). Methods: Collaborating with the EU NEXT study (Nurses’ Early eXit sTudy), the longitudinal study was conducted in China, and the psychosocial work environment was measured with the Copenhagen Psychosocial Questionnaire (COPSOQ). A total of 3,088 registered female nurses working in hospitals were eligible for the baseline analyses by multivariate logistic regression, and 1,521 for the one-year follow-up analyses by multivariate Poisson regression. Results: A wide range of psychosocial factors at work — in particular, increased emotional demands, decreased meaning of work, decreased commitment to the workplace, and decreased job satisfaction — were associated with ITL in both baseline analyses and prospective analyses after adjusting for numerous confounders. Conclusions: The findings suggest that unfavourable psychosocial work environment predicts ITL in Chinese nurses. Improvements in the psychosocial work environment may be helpful in retention of the nursing workforce.
Fieldnotes: a forensic
Authors: Eichhorn Kate
Published: December 2009

This poetic investigation probes the linguistic and epistemological effects of the increasingly widespread circulation of forensic discourses in the media and popular culture. Further consideration is given to the disproportionate availability of forensic expertise and technologies when the bodies under investigation are White and located in industrialized nations. A brief preface, “Notes on an Investigation,” situates this project in relationship to the tradition of investigative poetics. The selection of poems that follow features four scenes of forensic investigation explored from various standpoints, including the standpoints of the ethnographer, forensic anthropologist, victim, and perpetrator of violence. The poems reflect their disarticulated content, incorporating fragments of texts collected and reassembled from anthropology textbooks, newspaper articles, court reports, crime novels, and CSI scripts.
Single-Access Gastrostomy (SAG) Dispenses Endoscopy or Laparoscopy: A Simple Method Under Local Anesthesia
Authors: Zorron Ricardo , Cazarim Davi , Flores Daniel , Fontes Meyer Carlos André , de Castro Leonardo Machado , Kanaan Eduardo
Published: December 2009

Objective. Gastrostomy for feeding or desobstructive purposes is often performed transendoscopically. However, as endoscopy specialists and instruments are not widely available in community hospitals in Brazil, an alternative method was developed at the authors’ institution. Surgical single-access gastrostomy (SAG), performed under local anesthesia and requiring no endoscopic guidance is described. Methods. The authors used the SAG technique on 19 patients eligible for gastrostomy, and the data were prospectively documented. After local anesthesia and a 1-cm incision, the gastric wall was localized under direct vision. Purse string sutures were placed to work as a fixed valve to rectus sheath. Results. SAG was feasible in all patients. Minor complications occurred in 3 patients. The mean operative time was 44.2 minutes, and the mean institution of gastrostomy feeding was 27.8 hours. Conclusion. SAG may dispense with the use of endoscopy and laparoscopy, providing a feasible, reproducible, and effective feeding gastrostomy in developing countries where alternative methods are not available.
Major Complications Associated With Xenograft Biologic Mesh Implantation in Abdominal Wall Reconstruction
Authors: Harth Karem C. , Rosen Michael J.
Published: December 2009

Background. There is limited research for xenograft biologic mesh performance in the setting of infection despite widespread use and significant associated costs. Design. The authors retrospectively reviewed an FDA database for reported xenograft adverse events (AEs). All meshes were used in the setting of abdominal wall reconstruction from 1997 to 2008. Results. The authors identified 150 AEs. Permacol and Collamend comprised 75% (n = 112) of reported cases. Main AEs included acute mechanical failure (42%; n = 63), mesh disintegration (32%; n = 48), and poor mesh integration (13%; n = 20); 80% of cases were described as infected, and nearly 90% of AEs required reoperation. Conclusions . Major complications are reported to the FDA for xenograft biologic meshes. Cross-linked meshes had the most AE reports to the FDA. The intrinsic properties of meshes and how they relate to infection-related outcomes are poorly understood. The findings from this FDA database review point toward a need to carefully evaluate these products.
Laparoscopic Partial Nephrectomy Using FloSeal for Hemostasis: Technique and Experiences in 102 Patients
Authors: Wille Andreas H. , Johannsen Manfred , Miller Kurt , Deger Serdar
Published: December 2009

Objectives. The authors report their techniques, perioperative data, and oncological outcome for laparoscopic partial nephrectomy in a single-center experience with 3 different surgeons. Patients and methods. A total of 102 consecutive patients underwent laparoscopic transperitoneal partial nephrectomy for exophytic tumors using FloSeal for hemostasis. Mean age was 58 years (range = 26-79 years), and median tumor size was 2.6 cm (range = 0.5-8.5 cm). In 84 cases, the renal artery was clamped using endoscopic bulldog clamps, and tumor resection was performed using scissors or the harmonic scalpel. Hemostasis was achieved by application of FloSeal; lesions of the collecting system were closed with Lahodny sutures in 33 cases (31%). Frozen sections were obtained for margin status. Results . All 102 procedures were successful with no intraoperative complications. Mean surgical time was 201 minutes (range = 60-355 minutes); clamping time was 25.8 minutes (range = 6-75 minutes) in 64 cases. Margins were negative in 92 cases; in 8 cases secondary resection was necessary to achieve negative margin status, and in 2 cases radical nephrectomy was performed. Histological findings were clear-cell carcinoma in 51 (50.0%), papillary carcinoma in 26 (25.5%), and others in 25 (24.5%) cases. At a mean follow-up of 32 months (12-62 months), no recurrence was observed. Conclusions. Laparoscopic partial nephrectomy with the use of FloSeal is a feasible and safe method for treatment of small renal masses. The technique is reproducible by surgeons who are used to complex laparoscopic procedures. Patient outcome during follow-up was comparable with data published for open standard procedures.
Incidence of Testicular Cancer in the United States, 1999-2004
Authors: Townsend Julie S. , Richardson Lisa C. , German Robert R.
Published: December 2009

Testicular cancer is rare but primarily affects young men. To characterize the current incidence of testicular cancer in the United States, U.S. Cancer Statistics data from 1999 through 2004 were examined. Age-adjusted (2000 U.S. standard) incidence rates were calculated for seminoma and nonseminoma testicular germ cell tumors (TGCTs). Hispanic men had the largest increase in incidence rates for nonseminomas, followed by non-Hispanic White men (annual percentage change of 3.2% and 1.9%, respectively, p < .05). Nonseminomas peaked at a younger age for Hispanic, American Indian/Alaska Native (AIAN), and Asian/Pacific Islander (API) men. Whereas 9.6% of TGCTs were diagnosed at a distant stage in non-Hispanic White men, more Hispanic (16.1%), Black (13.8%), AIAN (16.8%), and API (14.9%) men with TGCTs were diagnosed with distant stage. Monitoring incidence rates for rare cancers by race/ethnicity has improved with national population-based cancer registry coverage. Disparities in diagnosis stage have implications for effective treatment of TGCTs.
Obstetric Brachial Plexus Palsy: a Comparison of Affected Infants Delivered Vaginally By Breech or Cephalic Presentation
Authors: Al-Qattan M.M. , El-Sayed A.A.F. , Al-Zahrani A.Y. , Al-Mutairi S.A. , Al-Harbi M.S. , Al-Mutairi A.M. , Al-Kahtani F.S.
Published: December 2009

In this retrospective study we compared obstetric brachial plexus palsy (OBPP) in two non-operated groups of newborn babies delivered vaginally by breech or cephalic presentation. There were 35 cases of OBPP in the breech group and 663 cases in the cephalic group. The former group was more likely to develop upper Erb’s palsy while the latter group was more likely to develop total palsy. The breech group also had a significantly lower mean birth weight, a significantly higher percentage of bilateral OBPP palsies and concurrent phrenic nerve palsy. Spontaneous recovery of shoulder abduction and elbow flexion in newborn babies with upper Erb’s palsy was significantly worse in the breech compared with the cephalic group. It was concluded that OBPP following vaginal breech delivery has several unique demographic features and breech babies with upper Erb’s palsy have a worse prognosis for spontaneous recovery than those in the cephalic group.
Local Technology Linkages and Supplier Upgrading in Global Value Chains: The Case of Swedish Engineering TNCs in Emerging Markets
Authors: Ivarsson Inge , Alvstam Claes Göran
Published: December 2009

We complement the existing global value chain literature by presenting empirical evidence on technology upgrading among domestic suppliers operating in the less-investigated producer-driven engineering industries. Unique firm-level data from 22 Swedish manufacturing affiliates and their 1349 suppliers in China, India, Brazil and Mexico show that domestically-owned suppliers are generally provided with substantial technological support by their TNC customers as part of regular business relations. The transfer of product and process technology is especially facilitated through a combination of local business linkages, which enhance tacit learning, and global business linkages, where the management challenges related to operating global sourcing strategies enhance mutual commitments from both buyers and suppliers. Thus, rather than resulting in ‘captive’ governance structures, our findings suggest that in these types of value chain ‘developmentaly’ buyer-supplier relations are likely in many emerging markets, resulting in technological upgrading of less capable, domestic suppliers.
Using mechanistic Bayesian networks to identify downstream targets of the Sonic Hedgehog pathway
Authors: Shah Abhik , Tenzen Toyoaki , McMahon Andrew P , Woolf Peter J
Published: December 2009

Background

The topology of a biological pathway provides clues as to how a pathway operates, but rationally using this topology information with observed gene expression data remains a challenge.

Results

We introduce a new general-purpose analytic method called Mechanistic Bayesian Networks (MBNs) that allows for the integration of gene expression data and known constraints within a signal or regulatory pathway to predict new downstream pathway targets. The MBN framework is implemented in an open-source Bayesian network learning package, the Python Environment for Bayesian Learning (PEBL). We demonstrate how MBNs can be used by modeling the early steps of the sonic hedgehog pathway using gene expression data from different developmental stages and genetic backgrounds in mouse. Using the MBN approach we are able to automatically identify many of the known downstream targets of the hedgehog pathway such as Gas1 and Gli1, along with a short list of likely targets such as Mig12.

Conclusions

The MBN approach shown here can easily be extended to other pathways and data types to yield a more mechanistic framework for learning genetic regulatory models.
Clonal dissemination of the multi-drug resistant Salmonella enterica serovar Braenderup, but not the serovar Bareilly, of prevalent serogroup C1 Salmonella from Taiwan
Authors: Chiou Chien-Shun , Lin Jui-Ming , Chiu Cheng-Hsun , Chu Chi-Hong , Chen Shu-Wun , Chang Yung-Fu , Weng Bor-Chun , Tsay Jwu-Guh , Chen Chyi-Liang , Liu Chien-Hsing , Chu Chishih
Published: December 2009

Background

Nontyphoidal Salmonella is the main cause of human salmonellosis. In order to study the prevalent serogroups and serovars of clinical isolates in Taiwan, 8931 Salmonellae isolates were collected from 19 medical centers and district hospitals throughout the country from 2004 to 2007. The pulsed-field eletrophoresis types (PFGE) and antibiotic resistance profiles of Salmonella enterica serovars Bareilly (S. Bareilly) and Braenderup (S. Braenderup) were compared, and multi-drug resistance (MDR) plasmids were characterized.

Results

Over 95% of human salmonellosis in Taiwan was caused by five Salmonella serogroups: B, C1, C2-C3, D1, and E1. S. Typhymurium, S. Enteritidis, S. Stanley and S. Newport were the four most prevalent serovars, accounting for about 64% of isolates. While only one or two major serovars from four of the most prevalent serogroups were represented, four predominant serovars were found in serogroup C1 Salmonellae. The prevalence was decreasing for S. Choleraeuis and S. Braenderup, and S. Virchow and increasing for S. Bareilly. S. Braenderup mainly caused gastroenteritis in children; in contrast, S. Bareiley infected children and elderly people. Both serovars differed by Xba I-PFGE patterns. Almost all S. Bareilly isolates were susceptible to antibiotics of interest, while all lacked plasmids and belonged to one clone. Two distinct major clones in S. Braenderup were cluster A, mainly including MDR isolates with large MDR plasmid from North Taiwan, and cluster B, mainly containing susceptible isolates without R plasmid from South Taiwan. In cluster A, there were two types of conjugative R plasmids with sizes ranging from 75 to 130 kb. Type 1 plasmids consisted of replicons F1A/F1B, bla
TEM, IS26, and a class 1 integron with the genes dfrA12-orfF-aadA2-qacE Δ1-sulI. Type 2 plasmids belonged to incompatibility group IncI, contained tnpA-bla
CMY-2-blc-sugE genetic structures and lacked both IS26 and class 1 integrons. Although type 2 plasmids showed higher conjugation capability, type 1 plasmids were the predominant plasmid.

Conclusions

Serogroups B, C1, C2-C3, D1, and E1 of Salmonella caused over 95% of human salmonellosis. Two prevalent serovars within serogroup C1, S. Bareilly and cluster B of S. Braenderup, were clonal and drug-susceptible. However, cluster A of S. Braenderup was MDR and probably derived from susceptible isolates by acquiring one of two distinct conjugative R plasmids.
Quantifying the impact of community quarantine on SARS transmission in Ontario: estimation of secondary case count difference and number needed to quarantine
Authors: Bondy Susan J , Russell Margaret L , Laflèche Julie ML , Rea Elizabeth
Published: December 2009

Background

Community quarantine is controversial, and the decision to use and prepare for it should be informed by specific quantitative evidence of benefit. Case-study reports on 2002-2004 SARS outbreaks have discussed the role of quarantine in the community in transmission. However, this literature has not yielded quantitative estimates of the reduction in secondary cases attributable to quarantine as would be seen in other areas of health policy and cost-effectiveness analysis.

Methods

Using data from the 2003 Ontario, Canada, SARS outbreak, two novel expressions for the impact of quarantine are presented. Secondary Case Count Difference (SCCD) reflects reduction in the average number of transmissions arising from a SARS case in quarantine, relative to not in quarantine, at onset of symptoms. SCCD was estimated using Poisson and negative binomial regression models (with identity link function) comparing the number of secondary cases to each index case for quarantine relative to non-quarantined index cases. The inverse of this statistic is proposed as the number needed to quarantine (NNQ) to prevent one additional secondary transmission.

Results

Our estimated SCCD was 0.133 fewer secondary cases per quarantined versus non-quarantined index case; and a NNQ of 7.5 exposed individuals to be placed in community quarantine to prevent one additional case of transmission in the community. This analysis suggests quarantine can be an effective preventive measure, although these estimates lack statistical precision.

Conclusions

Relative to other health policy areas, literature on quarantine tends to lack in quantitative expressions of effectiveness, or agreement on how best to report differences in outcomes attributable to control measure. We hope to further this discussion through presentation of means to calculate and express the impact of population control measures. The study of quarantine effectiveness presents several methodological and statistical challenges. Further research and discussion are needed to understand the costs and benefits of enacting quarantine, and this includes a discussion of how quantitative benefit should be communicated to decision-makers and the public, and evaluated.
Increased hallux angle in children and its association with insufficient length of footwear: A community based cross-sectional study
Authors: Klein Christian , Groll-Knapp Elisabeth , Kundi Michael , Kinz Wieland
Published: December 2009

Background

Wearing shoes of insufficient length during childhood has often been cited as leading to deformities of the foot, particularly to the development of hallux valgus disorders. Until now, these assumptions have not been confirmed through scientific research. This study aims to investigate whether this association can be statistically proven, and if children who wear shoes of insufficient length actually do have a higher risk of a more pronounced lateral deviation of the hallux.

Methods

858 pre-school children were included in the study. The study sample was stratified by sex, urban/rural areas and Austrian province. The hallux angle and the length of the feet were recorded. The inside length of the children's footwear (indoor shoes worn in pre-school and outdoor shoes) were assessed. Personal data and different anthropometric measurements were taken. The risk of hallux valgus deviation was statistically tested by a stepwise logistic regression analysis and the relative risk (odds ratio) for a hallux angle ≥ 4 degrees was calculated.

Results

Exact examinations of the hallux angle could be conducted on a total of 1,579 individual feet. Only 23.9% out of 1,579 feet presented a straight position of the great toe. The others were characterized by lateral deviations (valgus position) at different degrees, equalling 10 degrees or greater in 14.2% of the children's feet.

88.8% of 808 children examined wore indoor footwear that was of insufficient length, and 69.4% of 812 children wore outdoor shoes that were too short. A significant relationship was observed between the lengthwise fit of the shoes and the hallux angle: the shorter the shoe, the higher the value of the hallux angle. The relative risk (odds ratio) of a lateral hallux deviation of ≥ 4 degrees in children wearing shoes of insufficient length was significantly increased.

Conclusions

There is a significant relationship between the hallux angle in children and footwear that is too short in length. The fact that the majority of the children examined were wearing shoes of insufficient length makes the issue particularly significant. Our results emphasize the importance of ensuring that children's footwear fits properly.
Solution structure of the Equine Infectious Anemia Virus p9 protein: a rationalization of its different ALIX binding requirements compared to the analogous HIV-p6 protein
Authors: Sharma Alok , Bruns Karsten , Röder René , Henklein Peter , Votteler Jörg , Wray Victor , Schubert Ulrich
Published: December 2009

Background

The equine infection anemia virus (EIAV) p9 Gag protein contains the late (L-) domain required for efficient virus release of nascent virions from the cell membrane of infected cell.

Results

In the present study the p9 protein and N- and C-terminal fragments (residues 1-21 and 22-51, respectively) were chemically synthesized and used for structural analyses. Circular dichroism and 1H-NMR spectroscopy provide the first molecular insight into the secondary structure and folding of this 51-amino acid protein under different solution conditions. Qualitative 1H-chemical shift and NOE data indicate that in a pure aqueous environment p9 favors an unstructured state. In its most structured state under hydrophobic conditions, p9 adopts a stable helical structure within the C-terminus. Quantitative NOE data further revealed that this α-helix extends from Ser-27 to Ser-48, while the N-terminal residues remain unstructured. The structural elements identified for p9 differ substantially from that of the functional homologous HIV-1 p6 protein.

Conclusions

These structural differences are discussed in the context of the different types of L-domains regulating distinct cellular pathways in virus budding. EIAV p9 mediates virus release by recruiting the ALG2-interacting protein X (ALIX) via the YPDL-motif to the site of virus budding, the counterpart of the YPXnL-motif found in p6. However, p6 contains an additional PTAP L-domain that promotes HIV-1 release by binding to the tumor susceptibility gene 101 (Tsg101). The notion that structures found in p9 differ form that of p6 further support the idea that different mechanisms regulate binding of ALIX to primary versus secondary L-domains types.
Human immunodeficiency virus and human papilloma virus - why HPV-induced lesions do not spontaneously resolve and why therapeutic vaccination can be successful
Authors: van der Burg Sjoerd H , Palefsky Joel M
Published: December 2009

HIV and HPV can both cause chronic infections and are acquired during sexual contact. HIV infection results in a progressive loss of CD4+ T cells that is associated with an increased prevalence of HPV infections, type-specific persistence and an increase in HPV-associated malignancies. On the one hand this illustrates the important role of HPV-specific CD4+ helper T-cell immunity, on the other it shows the Achilles heel of the HPV-specific immune response. The use of highly active antiretroviral therapy (HAART) results in a rapid reduction of HIV and a reconstitution of systemic CD4+ T-cell levels. The use of HAART thus has the potential to raise immunity to HPV but to the surprise of many, the incidence of HPV-induced diseases has increased rather than declined since the introduction of HAART. Here, the knowledge on how HPV-induced diseases develop in the face of a non-compromised immune system will be used to explain why the effect of HAART on HPV-induced diseases is modest at best. Furthermore, exciting new data in the field of therapeutic vaccines against HPV will be discussed as this may form a more durable and clinically successful therapeutic approach for the treatment of HPV-induced high-grade lesions in HIV-positive subjects on HAART.
Replication and drug resistant mutation of HIV-1 subtype B' (Thailand B) variants isolated from HAART treatment individuals in China
Authors: Sun Jianping , Ma Liying , Yu Xiaoling , Huang Yang , Yuan Lin , Shao Yiming
Published: December 2009

Background

Drug resistant HIV-1 variants were emergent more and more in AIDS individuals with highly active antiretroviral therapy (HAART) treatment. Understanding the replication and drug resistant mutation of HIV-1 variants isolated from HAART treatment individuals of China could help to design appropriate therapeutic strategies for these individuals.

Methods

Use GHOST cell lines to analysis the coreceptor usage of HIV-1 variants. Coculture with PBMCs to analysis the replication capacity. Use RT-PCR to analysis the drug resistant mutation ofpolgene.

Results

13 HIV-1 variants experienced HAART were included in this study. 5 HIV-1 variants used CCR5 coreceptor (R5), while 8 use both CCR5 and CXCR4 coreceptor (R5X4). The replication capacity of R5X4 variants was no difference with R5 variants in vitro without antiretroviral drugs. Compare the drug resistant mutation between first HIV-1 variants and fourth variants; there were 37 drug resistant mutations in first variants and 32 drug resistant mutations in fourth variants. Only 7 drug resistance mutations were lost after coculture for 4 weeks, and 2 drug resistance mutations were emerged.

Conclusion

These data suggested that the drug resistant level could not reduce in vitro in absence of antiretroviral drugs in few weeks. And maybe helpful for these HAART experienced individuals when change antiretroviral drugs.
Acute dosing of latrepirdine (Dimebon™), a possible Alzheimer therapeutic, elevates extracellular amyloid-β levels in vitro and in vivo
Authors: Steele John W , Kim Soong H , Cirrito John R , Verges Deborah K , Restivo Jessica L , Westaway David , Fraser Paul , Hyslop Peter St George , Sano Mary , Bezprozvanny Ilya , Ehrlich Michelle E , Holtzman David M , Gandy Sam
Published: December 2009

Background

Recent reports suggest that latrepirdine (Dimebon™, dimebolin), a retired Russian antihistamine, improves cognitive function in aged rodents and in patients with mild to moderate Alzheimer's disease (AD). However, the mechanism(s) underlying this benefit remain elusive. AD is characterized by extracellular accumulation of the amyloid-β (Aβ) peptide in the brain, and Aβ-lowering drugs are currently among the most popular anti-amyloid agents under development for the treatment of AD. In the current study, we assessed the effect of acute dosing of latrepirdine on levels of extracellular Aβ using in vitro and in vivo experimental systems.

Results

We evaluated extracellular levels of Aβ in three experimental systems, under basal conditions and after treatment with latrepirdine. Mouse N2a neuroblastoma cells overexpressing Swedish APP were incubated for 6 hr in the presence of either vehicle or vehicle + latrepirdine (500pM-5 μM). Synaptoneurosomes were isolated from TgCRND8 mutant APP-overexpressing transgenic mice and incubated for 0 to 10 min in the absence or presence of latrepirdine (1 μM or 10 μM). Drug-naïve Tg2576 Swedish mutant APP overexpressing transgenic mice received a single intraperitoneal injection of either vehicle or vehicle + latrepirdine (3.5 mg/kg). Picomolar to nanomolar concentrations of acutely administered latrepirdine increased the extracellular concentration of Aβ in the conditioned media from Swedish mutant APP-overexpressing N2a cells by up to 64% (p = 0.01), while a clinically relevant acute dose of latrepirdine administered i.p. led to an increase in the interstitial fluid of freely moving APP transgenic mice by up to 40% (p = 0.01). Reconstitution of membrane protein trafficking and processing is frequently inefficient, and, consistent with this interpretation, latrepirdine treatment of isolated TgCRND8 synaptoneurosomes involved higher concentrations of drug (1-10 μM) and led to more modest increases in extracellular Aβx-42 levels (+10%; p = 0.001); of note, however, was the observation that extracellular Aβx-40 levels did not change.

Conclusions

Here, we report the surprising association of acute latrepirdine dosing with elevated levels of extracellular Aβ as measured in three independent neuron-related or neuron-derived systems, including the hippocampus of freely moving Tg2576 mice. Given the reported association of chronic latrepirdine treatment with improvement in cognitive function, the effects of chronic latrepirdine treatment on extracellular Aβ levels must now be determined.
Ranges of control in the transcriptional regulation of Escherichia coli
Authors: Sonnenschein Nikolaus , Hütt Marc-Thorsten , Stoyan Helga , Stoyan Dietrich
Published: December 2009

Background

The positioning of genes in the genome is an important evolutionary degree of freedom for organizing gene regulation. Statistical properties of these distributions have been studied particularly in relation to the transcriptional regulatory network. The systematics of gene-gene distances then become important sources of information on the control, which different biological mechanisms exert on gene expression.

Results

Here we study a set of categories, which has to our knowledge not been analyzed before. We distinguish between genes that do not participate in the transcriptional regulatory network (i.e. that are according to current knowledge not producing transcription factors and do not possess binding sites for transcription factors in their regulatory region), and genes that via transcription factors either are regulated by or regulate other genes. We find that the two types of genes ("isolated" and "regulatory" genes) show a clear statistical repulsion and have different ranges of correlations. In particular we find that isolated genes have a preference for shorter intergenic distances.

Conclusions

These findings support previous evidence from gene expression patterns for two distinct logical types of control, namely digital control (i.e. network-based control mediated by dedicated transcription factors) and analog control (i.e. control based on genome structure and mediated by neighborhood on the genome).
The transcription factor RBP-J is essential for retinal cell differentiation and lamination
Authors: Zheng Min-Hua , Shi Ming , Pei Zhe , Gao Fang , Han Hua , Ding Yu-Qiang
Published: December 2009

Background

The highly ordered vertebrate retina is composed of seven cell types derived from a common pool of retinal progenitor cells (RPCs), and is a good model for the studies of cell differentiation and interaction during neural development. Notch signaling plays a pivotal role in retinogenesis in mammals, but the full scope of the functions of Notch pathway, and the underlying molecular mechanisms, remain unclear.

Results

In this study, we conditionally knocked out RBP-J, the critical transcription factor downstream to all four Notch receptors, in RPCs of mouse retina at different developmental stages. Disruption of RBP-J at early retinogenesis resulted in accelerated RPCs differentiation, but only photoreceptors and ganglion cells were overrepresented, with other neuronal populations diminished. Similarly, deletion of RBP-J at early postnatal days also led to overproduction of photoreceptors, suggesting that RBP-J governed RPCs specification and differentiation through retinogenesis. In all the RBP-J deletion models, the retinal laminar structures were distorted by the formation of numerous rosette-like structures, reminiscent of β-catenin deficient retina. Indeed, we found that these rosettes aligned with gaps in β-catenin expression at the apical surface of the retina. By in vivo electroporation-mediated transfection, we demonstrated that lamination defects in RBP-J deficient retinae were rescued by overexpressing β-catenin.

Conclusions

Our data indicate that RBP-J-mediated canonical Notch signaling governs retinal cell specification and differentiation, and maintains retinal lamination through the expression of β-catenin.
Reduced expression of cenp-e in human hepatocellular carcinoma
Authors: Liu Zijie , Ling Kang , Wu Xia , Cao Ju , Liu Bin , Li Suyan , Si Qiong , Cai Yan , Yan Chen , Zhang Yan , Weng Yaguang
Published: December 2009

Background

CENP-E, one of spindle checkpoint proteins, plays a crucial role in the function of spindle checkpoint. Once CENP-E expression was interrupted, the chromosomes can not separate procedurally, and may result in aneuploidy which is a hallmark of most solid cancers, such as hepatocellular carcinoma (HCC). We investigate the expression of CENP-E in human hepatocellular carcinoma,. and analyze the effect of low CENP-E expression on chromosome separation in normal liver cell line (LO2).

Methods

We determined its levels in HCC and para-cancerous tissues, human hepatocellular carcinoma-derived cell line (HepG2) and LO2 cell line using real time quantitative PCR (QPCR) and Western blot. Further to know whether reduction in CENP-E expression impairs chromosomes separation in LO2 cells. we knocked down CENP-E using shRNA expressing vector and then count the aneuploid in LO2 cells using chromosomal counts assay.

Results

We found that both CENP-E mRNA and protein levels were significantly reduced in HCC tissues and HepG2 cells compared with para-cancerous tissues and LO2 cells, respectively. A significantly-increased proportion of aneuploid in these down-knocked LO2 cells compared with those treated with control shRNA vector.

Conclusions

Together with other results, these results reveal that CENP-E expression was reduced in human HCC tissue, and low CENP-E expression result in aneuploidy in LO2 cells.
Interleukin-23 is critical for full-blown expression of a non-autoimmune destructive arthritis and regulates interleukin-17A and RORγt in γδ T cells
Authors: Cornelissen Ferry , Mus Adriana MC , Asmawidjaja Patrick S , van Hamburg Jan Piet , Tocker Joel , Lubberts Erik
Published: December 2009

Introduction

Interleukin (IL)-23 is essential for the development of various experimental autoimmune models. However, the role of IL-23 in non-autoimmune experimental arthritis remains unclear. Here, we examined the role of IL-23 in the non-autoimmune antigen-induced arthritis (AIA) model. In addition, the regulatory potential of IL-23 in IL-17A and retinoic acid-related orphan receptor gamma t (RORγt) expression in CD4+ and TCRγδ+ T cells was evaluated systemically as well as at the site of inflammation.

Methods

Antigen-induced arthritis was induced in wild-type, IL-23p19-deficient and IL-17 Receptor A - knockout mice. At different time points, synovial cytokine and chemokine expression was measured. At days 1 and 7 of AIA, splenocytes and joint-infiltrating cells were isolated and analyzed for intracellular IL-17A and interferon (IFN)-γ ex-vivo by flow cytometry. In splenic CD4+ and TCRγδ+ T cells gene expression was quantified by flow cytometry and quantitative PCR.

Results

IL-23 was critical for full-blown AIA. Lack of IL-23 did not prevent the onset of joint inflammation but stopped the progression to a destructive synovitis. IL-23 regulated IL-17A expression in CD4+ T cells in the spleen. Of note, IL-17A and IFN-γ expression was reduced in CD4+ T cells in the inflamed joints of IL-23p19-deficient mice. Interestingly, IL-23 was also critical for the induction of IL-17A and RORγt but not IFN-γ in TCRγδ+ T cells in the inflamed joints. The importance of the IL-23/IL-17 axis was further confirmed using IL-17 Receptor A knockout mice showing significantly milder AIA compared to control mice, with a disease course comparable to that of IL-23p19-deficient mice.

Conclusions

These data show that IL-23 is critical for full-blown expression of a non-autoimmune destructive arthritis and regulates the proportion of IL-17A and IFN-γ-positive CD4+ T cells at the site of inflammation. Furthermore, IL-23 regulates IL-17A and RORγt expression in TCRγδ T cells in arthritis. These findings indicate that regulating the IL-23 pathway may have therapeutic potential in non-autoimmune arthritis.