bluuebunny/crossref_metadata_2025_split huggingface dataset:
Bone Fragility Contributes to the Risk of Fracture in Children, Even After Moderate and Severe Trauma
Authors: Clark Emma M , Ness Andy R , Tobias Jon H 
Published: October 2007

Abstract
We prospectively examined whether the relationship between skeletal fragility and fracture risk in children 9.9 ± 0.3 (SD) yr is affected by trauma level. Bone size relative to body size and humeral vBMD showed similar inverse relationships with fracture risk, irrespective of whether fractures followed slight or moderate/severe trauma.
Introduction: Fracture risk in childhood is related to underlying skeletal fragility. However, whether this relationship is confined to low-trauma fractures or whether skeletal fragility also contributes to the risk of fracture caused by higher levels of trauma is currently unknown.
Materials and Methods: Total body DXA scan results obtained at 9.9 yr of age were linked to reported fractures over the following 2 yr in children from the Avon Longitudinal Study of Parents and Children. DXA scan results that were subsequently derived included total body less head (TBLH) bone size relative to body size (calculated from TBLH area adjusted for height and weight) and humeral volumetric BMD (vBMD; derived from subregional analysis at this site). Trauma level was assigned using the Landin classification based on a questionnaire asking about precipitating causes.
Results: Of the 6204 children with available data, 549 (8.9%) reported at least one fracture over the follow-up period, and trauma level was assigned in 280 as follows: slight trauma, 56.1%; moderate trauma, 41.0%; severe trauma, 2.9%. Compared with children without fractures, after adjustment for age, sex, socioeconomic status, and ethnicity, children with fractures from both slight and moderate/severe trauma had a reduced bone size relative to body size (1133 cm2 in nonfractured children versus 1112 cm2 for slight trauma fractures, p &lt; 0.001; 1112 cm2 for moderate/severe trauma fractures, p = 0.001) and reduced humeral vBMD (0.494 g/cm3 in nonfractured children versus 0.484 g/cm3 for slight trauma fractures, p = 0.036; and 0.482g/cm3 for moderate/severe trauma fractures, p = 0.016).
Conclusions: Skeletal fragility contributes to fracture risk in children, not only in fractures caused by slight trauma but also in those that result from moderate or severe trauma.
Osteogenic Differentiation of Human Adipose Tissue-Derived Stem Cells Is Modulated by the miR-26a Targeting of the SMAD1 Transcription Factor
Authors: Luzi Ettore , Marini Francesca , Sala Silvia Carbonell , Tognarini Isabella , Galli Gianna , Brandi Maria Luisa 
Published: October 2007

Abstract
The molecular mechanisms that regulate hADSC differentiation toward osteogenic precursors and subsequent bone-forming osteoblasts is unknown. Using osteoblast precursors obtained from subcutaneous human adipose tissue, we observed that microRNA-26a modulated late osteoblasts differentiation by targeting the SMAD1 transcription factor.
Introduction: Elucidation of the molecular mechanisms guiding human adipose tissue-derived stem cells (hADSCs) differentiation is of extreme importance for improving the treatment of bone-related diseases such as osteoporosis. The aim of this study was to identify microRNA as a regulator of the osteogenic differentiation of hADSCs.
Materials and Methods: Osteoblast differentiation of hADSCs was induced by treatment with dexamethasone, ascorbic acid, and β-glycerol phosphate. The expression of osteoblastic phenotype was evaluated after the induction by simultaneous monitoring of alkaline phosphatase activity, the expression of genes involved in osteoblastic differentiation by real-time RT-PCR, and mineralization at the same time. MicroRNA expression was determined by Northern blot, and transfection of both antisense miR-RNA and sensor plasmids was done to validate the inhibitory role of microRNA during hADSC osteogenesis. Western blot was used to determine the expression levels of the SMAD1 protein. qRT-PCR analysis was used to compare the expression patterns of osteoblastic markers in transfected cells.
Results and Conclusions: We analyzed the role of microRNA 26a (miR-26a) during differentiation of hADSCs. Northern blot analysis of miR-26a during hADSC differentiation showed increased expression, whereas expression of the SMAD1 protein was complementary to that of miR-26a. Because the highest expression of miR-26a and the lowest expression of SMAD1 protein were reached at hADSC terminal differentiation, we carried out our study during the late stages of hADSC differentiation. The inhibition of miR-26a, by 2′-O-methyl-antisense RNA, increased protein levels of its predicted target, SMAD1 transcription factor, in treated osteoblasts, upregulating bone marker genes and thus enhancing osteoblast differentiation. Our data suggest a role for miR-26a in the differentiation induced by treatment with dexamethasone, ascorbic acid, and β-glycerol phosphate of hADSCs toward the osteogenic lineage by targeting its predicted target, the SMAD1 protein. This study contributes to a better knowledge of molecular mechanisms governing hADSC differentiation by proposing a microRNA-based control of late differentiation.
Identifying the Relative Contributions of Rac1 and Rac2 to Osteoclastogenesis
Authors: Wang Yongqiang , Lebowitz Dina , Sun Chunxiang , Thang Herman , Grynpas Marc D , Glogauer Michael 
Published: October 2007

Abstract
Rac small GTPases may play an important regulatory role in osteoclastogenesis. Our in vitro and in vivo results show that both Rac1 and Rac2 are required for optimal osteoclast differentiation, but Rac1 is more critical. Rac1 is the key Rac isoform responsible for regulating ROS generation and the actin cytoskeleton during the multiple stages of osteoclast differentiation.
Introduction: Recent evidence suggests that the Rac small GTPases may play an important regulatory role in osteoclastogenesis. This finding is important because bisphosphonates may regulate their antiresorptive/antiosteoclast effects through the modification of Rho family of small GTPases.
Materials and Methods: To elucidate the specific roles of the Rac1 and Rac2 isoforms during osteoclastogenesis, we used mice deficient in Rac1, Rac2, or both Rac1 and Rac2 in monocyte/osteoclast precursors. Macrophage-colony stimulating factor (M-CSF)– and RANKL-mediated osteoclastogenesis in vitro was studied by using bone marrow-derived mononucleated preosteoclast precursors (MOPs). The expression of osteoclast-specific markers was examined using quantitative real-time PCR and Western blot analysis. Free actin barbed ends in bone marrow MOPs after M-CSF stimulation was determined. The ability of MOPs to migrate toward M-CSF was assayed using Boyden chambers. Margin spreading on heparin sulfate-coated glass and RANKL-induced reactive oxygen species generation were also performed. Functional assays of in vitro-generated osteoclasts were ascertained using dentine sections from narwal tusks. Osteoclast levels in vivo were counted in TRACP and immunohistochemically stained distal tibial sections. In vivo microarchitexture of lumbar vertebrate was examined using μCT 3D imaging and analysis.
Results: We show here that, although both Rac isoforms are required for normal osteoclast differentiation, Rac1 deletion results in a more profound reduction in osteoclast formation in vitro because of its regulatory role in pre-osteoclast M-CSF-mediated chemotaxis and actin assembly and RANKL-mediated reactive oxygen species generation. This Rac1 cellular defect also manifests at the tissue level with increased trabecular bone volume and trabeculae number compared with wildtype and Rac2-null mice. This unique mouse model has shown for the first time that Rac1 and Rac2 play different and nonoverlapping roles during osteoclastogenesis and will be useful for identifying the key roles played by these two proteins during the multiple stages of osteoclast differentiation.
Conclusions: Rac1 and Rac2 play different and nonoverlapping roles during osteoclastogenesis. This model showed that Rac1 is the key Rac isoform responsible for regulating ROS generation and the actin cytoskeleton during the multiple stages of osteoclast differentiation.
Lean Mass and Not Fat Mass Is Associated With Male Proximal Femur Strength
Authors: Travison Thomas G , Araujo Andre B , Esche Gretchen R , Beck Thomas J , McKinlay John B 
Published: October 2007

AbstractObesity is suspected to confer protection against fracture, but evidence is mixed. We examined proximal femur geometry and body composition measures in a diverse group of 1171 men (30–79 yr of age). Analyses showed that nonbone lean mass, but not fat mass, is independently associated with measures of proximal femur density, axial and bending strength, and resistance to buckling.Introduction: Obesity is often said to confer protection against fracture, but the mechanisms driving such an association remain poorly understood. We hypothesized that the effect of increased body mass on bone structure would be accounted for by total and/or appendicular nonbone lean mass, and that once these trends were removed, fat mass would show no protective influence. To test this hypothesis, we examined body composition and geometric indices of proximal femur strength in an ethnically diverse (black, Hispanic, and white) sample of randomly selected men, 30–79 yr of age.Materials and Methods: Data were obtained from N = 1171 community-dwelling subjects enrolled in the cross-sectional Boston Area Community Health/Bone study. Body composition was obtained by DXA. Hip geometry parameters at the narrow neck, intertrochanter, and shaft were obtained using Hip Structural Analysis of DXA images. These measures included BMD, bone material in cross-sections (cross-sectional area), bending strength (section modulus), and propensity to buckle under compression (average buckling ratio). Analyses controlled for age, race/ethnicity, height, and physical activity.Results: In exploratory analyses, lean mass, fat mass, and BMI were each positively associated with hip strength. However, controlling for lean mass was sufficient to remove the positive, and induce a negative, association for fat mass or BMI. Associations between lean mass and hip strength were strongest and resistant to control for other measures. Lean mass alone was sufficient to account for a substantial proportion of racial/ethnic difference in hip strength measures, whereas fat mass exhibited no comparable explanatory power.Conclusions: The positive association between relative weight and proximal femur strength is accounted for by lean mass, suggesting that, in men, the protective effect of BMI in preventing fracture is mediated not by adipose tissue but by the influence of increased muscle mass accompanying elevated BMI.
Modified Form of the Fibrinogen Bβ Chain (des-Gln Bβ), a Potential Long-Lived Marker of Pancreatitis
Authors: Schmidt David , Brennan Stephen O 
Published: October 2007

AbstractBackground: During an investigation of genetic variants of fibrinogen, we observed a novel form of the Bβ chain, with a mass decrease of approximately 128 Da, in one of the controls. The plasma sample originated from an individual who had experienced acute pancreatitis a week earlier but whose serum amylase activity had returned to normal. We investigated the structure of the modified fibrinogen and explored its relationship to pancreatic disease.Method: Fibrinogen was isolated from the plasma of 9 individuals with increased pancreatic amylase activity (114–1826 U/L) and presumed pancreatitis and from 6 control individuals with amylase activities &lt;56 U/L. Fibrinogen (or fibrin) Bβ chains were isolated by reversed-phase HPLC and analyzed directly by electrospray ionization mass spectrometry. Tryptic and CNBr peptide mapping and thrombin treatment pinpointed the location of the 128-Da loss in mass.Results: The acquired fibrinogen Bβ chain modification was attributable to the loss of its C-terminal glutamine residue. Incubating purified fibrinogen with pancreatic carboxypeptidase A (CpA) produced an identical modification. The des-Gln Bβ fibrinogen accounted for &gt;80% of the Bβ chains in 3 of the individuals with increased amylase but only approximately 5% of the Bβ chains in control samples.Conclusion: Pancreatic CpA activity is used as an index of acute pancreatic disease, but given that the circulatory half-lives of fibrinogen and CpA are approximately 4 days and only 2.5 h, respectively, measuring des-Gln Bβ fibrinogen, the in vivo product of CpA activity, could provide clinicians with retrospective evidence of disease.
Order-Entry: allgemeine Gesichtspunkte und eigene Erfahrungen / Order entry: general points of view and personal experience
Authors: Luthe Hilmar , Backhaus Susanne , Montag Bernd 
Published: October 2007

Zusammenfassung
Effizienz bestimmt den Alltag im Gesundheitswesen unter immer stärker werdendem Kostendruck. Ein wichtiger Partner in der Effizienz im Gesundheitswesen ist die Labordiagnostik, denn ohne verlässliche und rasch verfügbare Laborergebnisse verzögern sich Behandlungen, werden Operationen verschoben und die Patientenverweildauer steigt. Die Lösung für die Bewältigung dieser Herausforderungen ist das workflow-unterstützende Auftragsmanagement mit Hilfe von „Order-Entry”. Klinische IT-Lösungen werden somit zu einem kritischen Erfolgsfaktor. Vor zwei Jahren wurde das Pilotprojekt „Order-Entry” im Klinikum der Universität Göttingen gestartet. Auf den Stationen wurden kleine, flexible Barcode-Drucker installiert und auf den Stationsrechnern wurden die bekannten Laborauftragsbelege elektronisch abgebildet. Mit wenigen Befehlen am Stationscomputer werden zu jeder Probe die gewünschten Analysen online in der Bildschirmmaske markiert und gleichzeitig die Barcodeetiketten mit allen notwendigen Angaben gedruckt und entsprechend der Monovettenfarbe gekennzeichnet. Die mit dem farbig richtigen Barcode versehenen Probengefäße werden in das Labor geschickt und dort in das Labor-System eingeschleust.
Qualitätsmanagement in medizinischen Laboratorien – neue Richtlinie der Bundesärztekammer und Akkreditierung nach ISO-Konzept im Vergleich / Quality management in medical laboratories – comparison between the new Guideline of the Federal Medical Association and accreditation according to ISO standards
Authors: Spitzenberger Folker , Hafner Gerd , Soltau Undine 
Published: October 2007

Zusammenfassung
Mit der zukünftigen „Richtlinie der Bundesärztekammer zur Qualitätssicherung laboratoriumsmedizinischer Untersuchungen” wird in Deutschland erstmals die Implementierung von Elementen eines umfassenden Qualitätsmanagements in medizinischen Laboratorien obligatorisch werden. Demgegenüber stehen bisher freiwillige, auf der Basis der Normen DIN EN ISO 15189 und DIN EN ISO/IEC 17025 durchgeführte Akkreditierungsverfahren, die in Deutschland entweder im Geltungsbereich des Medizinproduktegesetzes oder im privaten Bereich erfolgen. Auf der Grundlage des 2. MPG-Änderungsgesetzes gelingt die Formulierung einer Richtlinie, die für alle Anwender in der Heilkunde Qualitätssicherungsmaßnahmen einführt, die über die analytische Phase der laboratoriumsmedizinischen Untersuchungen deutlich hinausgehen. Wesentliche Inhalte der DIN EN ISO 15189, zu denen vor allem die Anforderungen hinsichtlich des Personals, der Räumlichkeiten und Umgebungsbedingungen, der Laborausrüstung, der Präanalytik und dem Qualitätsmanagementsystem gehö ren, werden in die zukünftige Richtlinie übernommen werden. Trotzdem ist die Richtlinie statisch angelegt und etabliert statt eines Qualitätsmanagementsystems im Verständnis von internationalen Qualitätsmanagement-Prinzipien lediglich ein System der erweiterten Qualitätssicherung. Neben der neuen Richtlinie werden europarechtliche Regelungen zur Akkreditierung das deutsche Akkreditierungssystem für medizinische Laboratorien entscheidend beeinflussen.
In-vitro-Diagnostik von Nahrungsmittelallergien. Positionspapier der Deutschen Gesellschaft für Allergie und Klinische Immunologie (DGAKI) und des Ärzteverbandes Deutscher Allergologen (ÄDA) / In vitro diagnostics in food allergy. Position paper of the German Society of Allergy and Clinical Immunology (DGAKI) and the Society of German Allergologists (ÄDA)
Authors: Kleine-Tebbe Jörg , Fuchs Thomas , Lepp Ute , Niggemann Bodo , Saloga Joachim , Vieluf Ines , Vieths Stefan , Werfel Thomas , Zuberbier Torsten , Jäger Lothar 
Published: October 2007

Zusammenfassung
Den wichtigsten Stellenwert für die In-vitro-Diagnostik von Nahrungsmittelallergien hat die Bestimmung des allergenspezifischen Immunglobulin E (IgE), i. d. R. nach Anamnese und Hauttest durchgeführt. Hunderte von Einzelallergenen und Kombinationen werden von einer Reihe von Herstellern angeboten. Unterschiedliche Allergene, Detektions- und Kalibrierungsmethoden erlauben selten einen direkten Vergleich der Resultate; sie können außerdem erheblich von den anamnestischen Angaben, den Ergebnissen im Hauttest und in der oralen Provokation abweichen. Zelluläre Laborverfahren (Histamin-Release-, Basophilen-Aktivierungs-Test und Leukotrien-freisetzungstest/CAST) sind für die Diagnostik von IgE-vermittelten Nahrungsmittelallergien derzeit nur in Einzelfällen bzw. für wissenschaftliche Fragestellungen zu empfehlen.

Nahrungmittelallergene: Klassische Nahrungsmittelallergene (häufiger im Kindesalter) bereiten als stabile Proteine selten Schwierigkeiten für die IgE-Diagnostik. Eine Bestimmung des IgE gegen definierte Proteine (z. B. Einzelallergene aus Kuhmilch oder Hühnerei) statt gegen das Gesamtprotein bringt gegenwärtig keine Vorteile für die Routinediagnostik. Bei Pollen- oder Latexsensibilisierung wird häufig IgE gegen kreuzreaktive, vorwiegend instabile Allergene in diversen Obst-, Gemüse- und Pflanzensorten nachgewiesen, das nur bei korrespondierenden Symptomen klinisch relevant ist – ein weiteres Argument für eine verdachtsorientierte, gezielte In-vitro-Diagnostik.

Indikationen für die IgE-Dianostik:

begründeter Verdacht einer Nahrungsmittelallergie, aber keine klare Aussage nach Anamnese und Hauttest,

Sensibilisierung auf Hauttest-ungeeignete Nahrungsmittel,

bedrohliche Reaktion auf Nahrungsmittel,

Hauttest bzw. seine Auswertung nicht möglich.

Interpretation der Ergebnisse:

falsche Ergebnisse durch unzureichende Reagenzienqualität oder Laborfehler (technische und methodische Fehler),

klinisch nicht relevante Ergebnisse durch stark erhöhtes Gesamt-IgE, zu hohe Nachweisempfindlichkeit oder kreuzreagierende Allergene (Interpretationsfehler).

Untauglich zur Nahrungsmittelallergie-Diagnostik: spezifisches IgG, zytotoxischer Lebensmitteltest, Elektroakupunktur, Bioresonanz (Methoden ohne Aussagekraft und/ oder Überprüfung).
Ungelöste Probleme:

optimale Qualität der Reagenzien,

Kalibration und Vergleichbarkeit unterschiedlicher Methoden,

serologische Kreuzreaktivität.

Zukünftige Studien zur klinischen Relevanz der In-vitro-Ergebnisse werden die Diagnostik und Beurteilung einer Nahrungsmittelallergie verbessern helfen.
Laborchemische Diagnostik der Liquorrhoe / Chemical analysis of cerebrospinal fluid leakage
Authors: Scheithauer Marc-Oliver , Wick Manfred , Tumani Hayrettin 
Published: October 2007

Zusammenfassung
Die Diagnose und Lokalisation einer Liquorfistel erworbener Ursache stellt weiterhin eine Herausforderung für viele Fachdisziplinen (u.a. Unfallchirurgie, HNO, Neurochirurgie, Kieferchirurgie) dar. Durch die Untersuchung liquorspezifischer Markerproteine kann der Nachweis einer Liquorfistel zuverlässig gelingen. Etabliert haben sich hierfür qualitative und quantitative Nachweismethoden, wie z.B. Beta-2 Transferrin oder Beta-Trace Protein (Prostaglandin-D-Synthase).
Für die operative Fistelobliteration ist eine genaue topografische Diagnostik erforderlich. Hierfür kommen bildgebende Verfahren zum Einsatz, die eine Anwendung von intrathekal applizierten Tracersubstanzen erfordern.
Beyond the Demonology of Power: The Study of German Foreign Policy after the Cold War
Authors: Berger Thomas 
Published: October 2007

Jeffrey Anderson, German Unification and the Union of Europe (Cambridge and New York: Cambridge University Press, 1999)Thomas Banchoff, The German Problem Transformed: Institutions, Politics and Foreign Policy, 1945-1995 (Ann Arbor, Michigan: University of Michigan Press, 1999)
Keeping Weimar at Bay: The German Federal Presidency since 1949
Authors: Helms Ludger 
Published: October 2007

Learning from the Weimar experience, the founding fathers of theFederal Republic eliminated the chance of a renewed institutionalizedconflict between the head of state and the federal governmentthrough the creation of the Basic Law [Grundgesetz ]. They primarilystrengthened the power of the chancellor and his cabinet by introducingthe “constructive” vote of no confidence and abolishing theprinciple of individual ministerial responsibility, while also reducingthe position of the federal president to a mere representative head ofstate. With these clear-cut constitutional arrangements it is not surprisingthat Germany has not been among the number of west Europeandemocracies (such as Italy or Austria) for which issuesregarding the power of heads of state have occupied a rather prominentposition on the political agenda of the 1990s.
Finite Element Methods forMaxwell Equations
Authors: Demkowicz Leszek 
Published: October 2007

AbstractThe article reviews fundamentals of finite element discretizations of time‐harmonic Maxwell equations. The paper includes a short introduction to Maxwell equations, derivation of the standard and regularized variational formulations, discussion of three fundamental Nedelec's elements in context of exact sequences, projection‐based interpolation, and the commuting diagram property. The presentation is biased towardhpdiscretizations andhpadaptivity.
Computability and Adaptivity inCFD
Authors: Hoffman J. , Johnson C. 
Published: October 2007

AbstractWe briefly recall research on adaptive computational methods for laminar compressible and incompressible flow, and then move on to present recent work on computability and adaptivity for turbulent incompressible flow, based on adaptive stabilized Galerkin finite element methods with duality‐based a posteriori error control for chosen output quantities of interest, here referred to asgeneral Galerkin G2 methods.We show in concrete examples that outputs such as mean values in time of drag and lift of turbulent flow around a bluff body are computable on a PC with a tolerance of a few percent using a few hundred thousand mesh points in space.
Uncertainty Quantification with Stochastic Finite Elements
Authors: Matthies Hermann G. 
Published: October 2007

AbstractUncertainty estimation arises at least implicitly in any kind of modeling of the real‐world, and it is desirable to actually quantify the uncertainty in probabilistic terms. Here the emphasis is on uncertain systems, where the randomness is assumed spatial. Traditional computational approaches usually use some form of perturbation or Monte Carlo simulation. This is contrasted here with more recent methods based on stochastic Galerkin approximations. Also some approaches to an adaptive uncertainty quantification are pointed out.
Cell and Tissue Organization
Authors: Sarraf Catherine E. 
Published: October 2007

AbstractThe aim of this chapter is to provide an introduction that will serve the following chapters. An understanding of normal cell and tissue organization is essential to being able to conceptualize changes that occur preceding the development of malignancy. Initial tissue progression takes place after fertilization and gastrulation, and then cell phenotypes specialize as specific tissues develop. Through morphogenesis and organogenesis, tissues described here are those of the gastrointestinal tract with the pancreas, liver, and lung; the primordial germ cells and gonads; vasculature and blood progenitor cells; central nervous system; epidermis; and breast. These have been chosen as they are amongst the most common sites in which primary malignancies are found. Normal, adult parenchymal cells of these are briefly explained, followed by a concise description of stem cell niches, where cancer stem cells might reside.