bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of Virtual Reality Simulator Training Method and Observational Learning on Surgical Performance
Authors: Snyder Christopher W. , Vandromme Marianne J. , Tyra Sharon L. , Porterfield John R. , Clements Ronald H. , Hawn Mary T. 
Published: November 2010

AbstractBackgroundVirtual reality (VR) simulators and Web‐based instructional videos are valuable supplemental training resources in surgical programs, but it is unclear how to optimally integrate them into minimally invasive surgical training.MethodsMedical students were randomized to proficiency‐based training on VR laparoscopy and endoscopy simulators by two different methods: proctored training (automated simulator feedback plus human expert feedback) or independent training (simulator feedback alone). After achieving simulator proficiency, trainees performed a series of laparoscopic and endoscopic tasks in a live porcine model. Prior to their entry into the animal lab, all trainees watched an instructional video of the procedure and were randomly assigned to either observe or not observe the actual procedure before performing it themselves. The joint effects of VR training method and procedure observation on time to successful task completion were evaluated with Cox regression models.ResultsThirty‐two students (16 proctored, 16 independent) completed VR training. Cox regression modeling with adjustment for relevant covariates demonstrated no significant difference in the likelihood of successful task completion for independent versus proctored training [Hazard Ratio (HR) 1.28; 95% Confidence Interval (CI) 0.96–1.72; p = 0.09]. Trainees who observed the actual procedure were more likely to be successful than those who watched the instructional video alone (HR 1.47; 95% CI 1.09–1.98; p = 0.01).ConclusionsProctored VR training is no more effective than independent training with respect to surgical performance. Therefore, time‐consuming human expert feedback during VR training may be unnecessary. Instructional videos, while useful, may not be adequate substitutes for actual observation when trainees are learning minimally invasive surgical procedures.
Hereditäre Paragangliome
Authors: Müller U. 
Published: November 2010

Zusammenfassung
Hereditäre Paragangliome/Phäochromozytome werden autosomal-dominant vererbt. Es lassen sich 3 Formen, PGL1, PGL3 und PGL4 unterscheiden. Sie werden verursacht durch Mutationen in den Genen SDHD, SDHC und SDHB, welche für Komponenten des Komplexes II der mitochondrialen Atmungskette (Succinat-Ubiquinon-Reduktase, SDH) kodieren. Bei allen 3 Formen findet sich „loss of heterozygosity“ (LOH) der Region des mutierten Gens in Tumor-DNA. Dies führt zu Funktionsverlust der SDH, Anhäufung von Succinat sowie Sauerstoffradikalen. Dadurch werden hypoxieabhängige Stoffwechselwege aktiviert, welche zur Tumorbildung führen könnten. Während PGL3 und PGL4 sowohl durch maternal als auch durch paternal vererbte Keimbahnmutationen der Gene SDHC bzw. SDHB verursacht werden, findet sich PGL1 fast ausschließlich bei paternaler Transmission des mutierten SDHD-Gens. Diese Beobachtung lässt sich erklären durch partielle Inaktivierung (Imprinting) des maternalen SDHD-Gens und Induktion hypoxieabhängiger Gene in Paragangliengewebe, wodurch der Verlust des gesamten maternalen Chromosoms 11 durch Non-Disjunction begünstigt werden könnte.
The UIAA Medical Commission Injury Classification for Mountaineering and Climbing Sports
Authors: Schöffl Volker , Morrison Audry , Hefti Urs , Ullrich Schwarz , Küpper Thomas 
Published: November 2010

Objective Variations in definitions, scores, and methodologies have created differences in the results and conclusions obtained from studies on mountaineering and climbing sports injuries and illnesses; this has made interstudy comparisons difficult or impossible. To develop a common, simple, and sport-specific scoring system to classify injuries and illnesses in mountaineering and climbing studies; such retrospective scoring would facilitate the analysis and surveillance of their frequencies, severity and fatalities, and outcomes of any treatment. Methods The UIAA (The International Mountaineering and Climbing Federation) makes recommendations, sets policy, and advocates on behalf of the climbing and mountaineering community internationally through its various commissions. Using a nominal group consensus model approach, a working group was formed during the UIAA Medical Commission's meeting in Adršpach – Zdoňov, in the Czech Republic, 2008. This group critically examined climbing and other relevant literature for various methodological approaches in measuring injury incident rates and severity, including data sources, and produced a working document that was later edited and ratified by all members of the UIAA Medical Commission. Results Definitions of injury location, injury classification, and fatality risk are proposed. Case fatality, time-related injury risk, and a standardized metric climbing difficulty scale are also defined. Conclusions The medical commission of the UIAA recommends the use of the described criteria and scores for future research in mountaineering and climbing sports in order to enable robust and comprehensive interstudy comparisons and epidemiological analysis.
Topological and symbolic dynamics for hyperbolic systems with holes
Authors: BUNDFUSS STEFAN , KRÜGER TYLL , TROUBETZKOY SERGE 
Published: November 2010

AbstractWe consider an axiom A diffeomorphism or a Markov map of an interval and the invariant set Ω* of orbits which never falls into a fixed hole. We study various aspects of the symbolic representation of Ω* and of its non-wandering set Ωnw. Our results are on the cardinality of the set of topologically transitive components of Ωnw and their structure. We also prove that Ω* is generically a subshift of finite type in several senses.
Banning front-of-package food labels: First Amendment constraints on public health policy
Authors: Lytton Timothy D 
Published: November 2010

AbstractIn recent months, the FDA has begun a crackdown on misleading nutrition and health claims on the front of food packages by issuing warning letters to manufacturers and promising to develop stricter regulatory standards. Leading nutrition policy experts Marion Nestle and David Ludwig have called for an even tougher approach: a ban on all nutrition and health claims on the front of food packages. Nestle and Ludwig argue that most of these claims are scientifically unsound and misleading to consumers and that eliminating them would ‘aid educational efforts to encourage the public to eat whole or minimally processed foods and to read the ingredients list on processed foods’. Nestle and Ludwig are right to raise concerns about consumer protection and public health when it comes to front-of-package food labels, but an outright ban on front-of-package nutrition and health claims would violate the First Amendment. As nutrition policy experts develop efforts to regulate front-of-package nutrition and health claims, they should be mindful of First Amendment constraints on government regulation of commercial speech.
Efficacy of Aspergillus galactomannan‐directed preemptive therapy for the prevention of invasive aspergillosis in organ transplant recipients
Authors: Marino I.R. , Panarello G. , Singh N. 
Published: November 2010

Editor's comment: This letter from Marino et al. represents confirmation of an important principle: a preemptive antimicrobial strategy based on a reliable laboratory finding is an excellent way to prevent clinical disease due to an important pathogen. We hope this approach can be expanded as useful early diagnostic techniques become more available. It is my belief that a therapeutic prescription based on a laboratory marker is a more robust approach than “empiric therapy,” where therapy is prescribed by algorithm rather than measurable laboratory findings (3). R.H. Rubin, MD
Multiple factors influencing the release of hTERT mRNA from pancreatic cancer cell lines in in vitro culture
Authors: Okada Gensaku , Watanabe Hiroyuki , Ohtsubo Koushiro , Mouri Hisatsugu , Yamaguchi Yasushi , Motoo Yoshiharu , Sawabu Norio 
Published: November 2010

AbstractSince telomerase expression is highly prevalent in human cancers, the quantitation of serum/plasma hTERT (human telomerase reverse transcriptase) mRNA levels may be useful for early detection of PCa (pancreatic cancer). To analyse the correspondence between exhTERT (extracellular hTERT) mRNA levels and hTERT expression, we designed a cell culture system to investigate factors modulating the extracellular levels of hTERT mRNA in media conditioned by eight PCa cell lines. We found that the level of exhTERT mRNA was dependent on cell growth rate. MIAPaCa‐2, PANC‐1, KLM‐1 and PK‐9 cells expressed high levels of exhTERT mRNA, independent of cell density, whereas proliferating PK‐59, BxPC‐3 and PK‐45H cells released low levels of exhTERT mRNA. The augmented release of mRNA by spontaneous dead MIAPaCa‐2 cells was further increased at postconfluence. In Capan‐1 cells, low correspondence of marker was also due to RNase secretion. Upon reaching confluence, some PCa cell lines showed down‐regulation of hTERT expression. Following cell—cell adhesion, as shown by E‐cadherin engagement, PK‐59 cells showed levels of extracellular message below the limits of detection, a loss not due to an increase in message degradation. These results suggest that the levels of exhTERT mRNA in the medium of PCa cell lines are altered not only in response to cell growth rate and cell destruction, but are responsive to extracellular cues such as RNases and cell density. A cell‐free assay for exhTERT mRNA may therefore not be useful for early detection of PCa.
Sensitivity and Specificity of French Language and Processing Measures for the Identification of Primary Language Impairment at Age 5
Authors: Thordardottir Elin , Kehayia Eva , Mazer Barbara , Lessard Nicole , Majnemer Annette , Sutton Ann , Trudeau Natacha , Chilingaryan Gevorg 
Published: November 2010

PurposeResearch on the diagnostic accuracy of different language measures has focused primarily on English. This study examined the sensitivity and specificity of a range of measures of language knowledge and language processing for the identification of primary language impairment (PLI) in French-speaking children. Because of the lack of well-documented language measures in French, it is difficult to accurately identify affected children, and thus research in this area is impeded.MethodThe performance of 14 monolingual French-speaking children with confirmed, clinically identified PLI (M= 61.4 months of age,SD= 7.2 months) on a range of language and language processing measures was compared with the performance of 78 children with confirmed typical language development (Mage = 58.9 months,SD= 5.7). These included evaluations of receptive vocabulary, receptive grammar, spontaneous language, narrative production, nonword repetition, sentence imitation, following directions, rapid automatized naming, and digit span. Sensitivity, specificity, and likelihood ratios were determined at 3 cutoff points: (a) −1SD,(b) −1.28SD,and (b) −2SDbelow mean values. Receiver operator characteristic curves were used to identify the most accurate cutoff for each measure.ResultsSignificant differences between the PLI and typical language development groups were found for the majority of the language measures, with moderate to large effect sizes. The measures differed in their sensitivity and specificity, as well as in which cutoff point provided the most accurate decision. Ideal cutoff points were in most cases between the mean and −1SD. Sentence imitation and following directions appeared to be the most accurate measures.ConclusionsThis study provides evidence that standardized measures of language and language processing provide accurate identification of PLI in French. The results are strikingly similar to previous results for English, suggesting that in spite of structural differences between the languages, PLI in both languages involves a generalized language delay across linguistic domains, which can be identified in a similar way using existing standardized measures.
Global Processing Speed in Children With Low Reading Ability and in Children and Adults With Typical Reading Ability: Exploratory Factor Analytic Models
Authors: Peter Beate , Matsushita Mark , Raskind Wendy H. 
Published: November 2010

PurposeTo investigate processing speed as a latent dimension in children with dyslexia and children and adults with typical reading skills.MethodExploratory factor analysis (FA) was based on a sample of multigenerational families, each ascertained through a child with dyslexia. Eleven measures—6 of them timed—represented verbal and nonverbal processes, alphabet writing, and motor sequencing in the hand and oral motor system. FA was conducted in 4 cohorts (all children, a subset of children with low reading scores, a subset of children with typical reading scores, and adults with typical reading scores; totalN= 829).ResultsProcessing speed formed the first factor in all cohorts. Both measures of motor sequencing speed loaded on the speed factor with the other timed variables. Children with poor reading scores showed lower speed factor scores than did typical peers. The speed factor was negatively correlated with age in the adults.ConclusionsThe speed dimension was observed independently of participant cohort, gender, and reading ability. Results are consistent with a unified theory of processing speed as a quadratic function of age in typical development and with slowed processing in poor readers.
Structural basis for substrate activation and regulation by cystathionine beta-synthase (CBS) domains in cystathionine β-synthase
Authors: Koutmos Markos , Kabil Omer , Smith Janet L. , Banerjee Ruma 
Published: November 2010

The catalytic potential for H
2
S biogenesis and homocysteine clearance converge at the active site of cystathionine β-synthase (CBS), a pyridoxal phosphate-dependent enzyme. CBS catalyzes β-replacement reactions of either serine or cysteine by homocysteine to give cystathionine and water or H
2
S, respectively. In this study, high-resolution structures of the full-length enzyme from
Drosophila
in which a carbanion (1.70 Å) and an aminoacrylate intermediate (1.55 Å) have been captured are reported. Electrostatic stabilization of the zwitterionic carbanion intermediate is afforded by the close positioning of an active site lysine residue that is initially used for Schiff base formation in the internal aldimine and later as a general base. Additional stabilizing interactions between active site residues and the catalytic intermediates are observed. Furthermore, the structure of the regulatory “energy-sensing” CBS domains, named after this protein, suggests a mechanism for allosteric activation by
S
-adenosylmethionine.
Structural and Metabolic Transitions of C4 Leaf Development and Differentiation Defined by Microscopy and Quantitative Proteomics in Maize
Authors: Majeran Wojciech , Friso Giulia , Ponnala Lalit , Connolly Brian , Huang Mingshu , Reidel Edwin , Zhang Cankui , Asakura Yukari , Bhuiyan Nazmul H. , Sun Qi , Turgeon Robert , van Wijk Klaas J. 
Published: November 2010

AbstractC4 grasses, such as maize (Zea mays), have high photosynthetic efficiency through combined biochemical and structural adaptations. C4 photosynthesis is established along the developmental axis of the leaf blade, leading from an undifferentiated leaf base just above the ligule into highly specialized mesophyll cells (MCs) and bundle sheath cells (BSCs) at the tip. To resolve the kinetics of maize leaf development and C4 differentiation and to obtain a systems-level understanding of maize leaf formation, the accumulation profiles of proteomes of the leaf and the isolated BSCs with their vascular bundle along the developmental gradient were determined using large-scale mass spectrometry. This was complemented by extensive qualitative and quantitative microscopy analysis of structural features (e.g., Kranz anatomy, plasmodesmata, cell wall, and organelles). More than 4300 proteins were identified and functionally annotated. Developmental protein accumulation profiles and hierarchical cluster analysis then determined the kinetics of organelle biogenesis, formation of cellular structures, metabolism, and coexpression patterns. Two main expression clusters were observed, each divided in subclusters, suggesting that a limited number of developmental regulatory networks organize concerted protein accumulation along the leaf gradient. The coexpression with BSC and MC markers provided strong candidates for further analysis of C4 specialization, in particular transporters and biogenesis factors. Based on the integrated information, we describe five developmental transitions that provide a conceptual and practical template for further analysis. An online protein expression viewer is provided through the Plant Proteome Database.
IgG4 antibodies against rodents in laboratory animal workers do not protect against allergic sensitization
Authors: Krop E. J. M. , Doekes G. , Heederik D. J. J. , Aalberse R. C. , van der Zee J. S. 
Published: November 2010

To cite this article: Krop EJM, Doekes G, Heederik DJJ, Aalberse RC, van der Zee JS. IgG4 antibodies against rodents in laboratory animal workers do not protect against allergic sensitization. Allergy 2011; 66: 517–522.AbstractBackground:  The modified Th2 response, defined as an IgG4 response in the absence of IgE, is suggested to protect against the development of allergic sensitization. However, studies suggesting this protective effect all had a cross‐sectional design, making it impossible to study the development of both responses.Aim of the study:  We aimed to study the dynamics in IgG4 antibodies in relation to allergic sensitization in an occupational cohort of starting laboratory animal workers. Moreover, we studied the relation between exposure, antibody responses, atopy and self reported allergic symptoms.Methods:  A total of 110 starting animal workers were followed for 2 years. IgG4 antibodies against rats and mice were assessed. Workers were tested for allergic sensitization and exposure to animal allergens was estimated. Symptom status was assessed using questionnaires.Results:  Rat and mouse specific IgG4 antibodies were present before the development of allergy and did not significantly change over time. Allergic sensitization was related to exposure and atopic status but high levels of IgG4 showed no protective effect. In contrary, workers that developed mouse specific sensitization during follow up had higher levels of mouse specific IgG4. Symptoms were related to allergic sensitization and IgG4 levels did not influence that relationship.Conclusions:  IgG4 antibodies are present before IgE antibodies develop and IgG4 levels are stable over time. In our occupational cohort, the modified Th2 response had no protective effect on development of sensitization or allergic symptoms.
Metformin attenuates ventricular hypertrophy by activating the AMP‐activated protein kinase–endothelial nitric oxide synthase pathway in rats
Authors: Zhang Cheng‐Xi , Pan Si‐Nian , Meng Rong‐Sen , Peng Chao‐Quan , Xiong Zhao‐Jun , Chen Bao‐Lin , Chen Guang‐Qin , Yao Feng‐Juan , Chen Yi‐Li , Ma Yue‐Dong , Dong Yu‐Gang 
Published: November 2010

Summary1. Metformin is an activator of AMP‐activated protein kinase (AMPK). Recent studies suggest that pharmacological activation of AMPK inhibits cardiac hypertrophy. In the present study, we examined whether long‐term treatment with metformin could attenuate ventricular hypertrophy in a rat model. The potential involvement of nitric oxide (NO) in the effects of metformin was also investigated.2. Ventricular hypertrophy was established in rats by transaortic constriction (TAC). Starting 1 week after the TAC procedure, rats were treated with metformin (300 mg/kg per day, p.o.), NG‐nitro‐l‐arginine methyl ester (l‐NAME; 50 mg/kg per day, p.o.) or both for 8 weeks prior to the assessment of haemodynamic function and cardiac hypertrophy.3. Cultured cardiomyocytes were used to examine the effects of metformin on the AMPK–endothelial NO synthase (eNOS) pathway. Cells were exposed to angiotensin (Ang) II (10−6 mol/L) for 24 h under serum‐free conditions in the presence or absence of metformin (10−3 mol/L), compound C (10−6 mol/L), l‐NAME (10−6 mol/L) or their combination. The rate of incorporation of [3H]‐leucine was determined, western blotting analyses of AMPK–eNOS, neuronal nitric oxide synthase (nNOS) and inducible nitric oxide synthase (iNOS) were undertaken and the concentration of NO in culture media was determined.4. Transaortic constriction resulted in significant haemodynamic dysfunction and ventricular hypertrophy. Myocardial fibrosis was also evident. Treatment with metformin improved haemodynamic function and significantly attenuated ventricular hypertrophy. Most of the effects of metformin were abolished by concomitant l‐NAME treatment. l‐NAME on its own had no effect on haemodynamic function and ventricular hypertrophy in TAC rats.5. In cardiomyocytes, metformin inhibited AngII‐induced protein synthesis, an effect that was suppressed by the AMPK inhibitor compound C or the eNOS inhibitor l‐NAME. The improvement in cardiac structure and function following metformin treatment was associated with enhanced phosphorylation of AMPK and eNOS and increased NO production.6. The findings of the present study indicate that long‐term treatment with metformin could attenuate ventricular hypertrophy induced by pressure overload via activation of AMPK and a downstream signalling pathway involving eNOS–NO.