bluuebunny/crossref_metadata_2025 huggingface dataset:
Association of hip strength estimates by finite-element analysis with fractures in women and men
Authors: Amin Shreyasee , Kopperdhal David L , Melton L Joseph , Achenbach Sara J , Therneau Terry M , Riggs B Lawrence , Keaveny Tony M , Khosla Sundeep
Published: February 2011

Finite-element analysis (FEA) of quantitative computed tomography (QCT) scans can estimate site-specific whole-bone strength. However, it is uncertain whether the site-specific detail included in FEA-estimated proximal femur (hip) strength can determine fracture risk at sites with different biomechanical characteristics. To address this question, we used FEA of proximal femur QCT scans to estimate hip strength and load-to-strength ratio during a simulated sideways fall and measured total hip areal and volumetric bone mineral density (aBMD and vBMD) from QCT images in an age-stratified random sample of community-dwelling adults age 35 years or older. Among 314 women (mean age ± SD: 61 ± 15 years; 235 postmenopausal) and 266 men (62 ± 16 years), 139 women and 104 men had any prevalent fracture, whereas 55 Women and 28 men had a prevalent osteoporotic fracture that had occurred at age 35 years or older. Odds ratios by age-adjusted logistic regression analysis for prevalent overall and osteoporotic fractures each were similar for FEA hip strength and load-to-strength ratio, as well as for total hip aBMD and vBMD. C-statistics (estimated areas under ROC curves) also were similar [eg, 0.84 to 0.85 (women) and 0.75 to 0.78 (men) for osteoporotic fractures]. In women and men, the association with prevalent osteoporotic fractures increased below an estimated hip strength of approximately 3000 N. Despite its site-specific nature, FEA-estimated hip strength worked equally well at predicting prevalent overall and osteoporotic fractures. Furthermore, an estimated hip strength below 3000 N may represent a critical level of systemic skeletal fragility in both sexes that warrants further investigation. © 2011 American Society for Bone and Mineral Research.
Differences in bone microarchitecture between postmenopausal Chinese-American and white women
Authors: Walker Marcella D , Liu X Sherry , Stein Emily , Zhou Bin , Bezati Ervis , McMahon Donald J , Udesky Julia , Liu George , Shane Elizabeth , Guo X Edward , Bilezikian John P
Published: February 2011

Chinese-American women have lower rates of hip and forearm fracture than white women despite lower areal bone density (aBMD) by dual X-ray absorptiometry (DXA). We recently reported higher trabecular (Dtrab) and cortical (Dcomp) bone density as well as greater trabecular (Tb.Th) and cortical thickness (C.Th) but smaller bone area (CSA), as measured by high-resolution peripheral quantitative computed tomography (HR-pQCT), in premenopausal Chinese-American compared with white women. These findings may help to account for the lower fracture rate among Chinese-American women but were limited to measurements in premenopausal women. This study was designed to extend these investigations to postmenopausal Chinese-American (n = 29) and white (n = 68) women. Radius CSA was 10% smaller in the Chinese-American versus the white group (p = .008), whereas their C.Th and Dcomp values were 18% and 6% greater (p < .001 for both). Tibial HR-pQCT results for cortical bone were similar to the radius, but Tb.Th was 11% greater in Chinese-American versus white women (p = .007). Tibial trabecular number and spacing were 17% lower and 20% greater, respectively, in Chinese-American women (p < .0001 for both). There were no differences in trabecular or whole-bone stiffness estimated by microstructural finite-element analysis, but Chinese-American women had a greater percentage of load carried by the cortical bone compartment at the distal radius and tibia. There was no difference in load distribution at the proximal radius or tibia. Whole-bone finite-element analysis may indicate that the thicker, more dense cortical bone and thicker trabeculae in postmenopausal Chinese-American women compensate for fewer trabeculae and smaller bone size. © 2011 American Society for Bone and Mineral Research.
Osteal macrophages promote in vivo intramembranous bone healing in a mouse tibial injury model
Authors: Alexander Kylie A , Chang Ming K , Maylin Erin R , Kohler Thomas , Müller Ralph , Wu Andy C , Van Rooijen Nico , Sweet Matthew J , Hume David A , Raggatt Liza J , Pettit Allison R
Published: February 2011

Bone-lining tissues contain a population of resident macrophages termed osteomacs that interact with osteoblasts in vivo and control mineralization in vitro. The role of osteomacs in bone repair was investigated using a mouse tibial bone injury model that heals primarily through intramembranous ossification and progresses through all major phases of stabilized fracture repair. Immunohistochemical studies revealed that at least two macrophage populations, F4/80+Mac-2−/lowTRACP− osteomacs and F4/80+Mac-2hiTRACP− inflammatory macrophages, were present within the bone injury site and persisted throughout the healing time course. In vivo depletion of osteomacs/macrophages (either using the Mafia transgenic mouse model or clodronate liposome delivery) or osteoclasts (recombinant osteoprotegerin treatment) established that osteomacs were required for deposition of collagen type 1+ (CT1+) matrix and bone mineralization in the tibial injury model, as assessed by quantitative immunohistology and micro–computed tomography. Conversely, administration of the macrophage growth factor colony-stimulating factor 1 (CSF-1) increased the number of osteomacs/macrophages at the injury site significantly with a concurrent increase in new CT1+ matrix deposition and enhanced mineralization. This study establishes osteomacs as participants in intramembranous bone healing and as targets for primary anabolic bone therapies. © 2011 American Society for Bone and Mineral Research.
The V–ATPase a3 subunit mutation R740S is dominant negative and results in osteopetrosis in mice
Authors: Ochotny Noelle , Flenniken Ann M , Owen Celeste , Voronov Irina , Zirngibl Ralph A , Osborne Lucy R , Henderson Janet E , Adamson S Lee , Rossant Janet , Manolson Morris F , Aubin Jane E
Published: February 2011

A mouse founder with high bone mineral density and an osteopetrotic phenotype was identified in an N-ethyl-N-nitrosourea (ENU) screen. It was found to carry a dominant missense mutation in the Tcirg1 gene that encodes the a3 subunit of the vacuolar type H+-ATPase (V–ATPase), resulting in replacement of a highly conserved amino acid (R740S). The +/R740S mice have normal appearance, size, and weight but exhibit high bone density. Osteoblast parameters are unaffected in bones of +/R740S mice, whereas osteoclast number and marker expression are increased, concomitant with a decrease in the number of apoptotic osteoclasts. Consistent with reduced osteoclast apoptosis, expression of Rankl and Bcl2 is elevated, whereas Casp3 is reduced. Transmission electron microscopy revealed that unlike other known mutations in the a3 subunit of V–ATPase, polarization and ruffled border formation appear normal in +/R740S osteoclasts. However, V–ATPases from +/R740S osteoclast membranes have severely reduced proton transport, whereas ATP hydrolysis is not significantly affected. We show for the first time that a point mutation within the a3 subunit, R740S, which is dominant negative for proton pumping and bone resorption, also uncouples proton pumping from ATP hydrolysis but has no effect on ruffled border formation or polarization of osteoclasts. These results suggest that the V0 complex has proton-pumping-independent functions in mammalian cells. © 2011 American Society for Bone and Mineral Research.
ImKTx1, a new Kv1.3 channel blocker with a unique primary structure
Authors: Chen Zongyun , Hu Youtian , Han Song , Yin Shijin , He Yawen , Wu Yingliang , Cao Zhijian , Li Wenxin
Published: February 2011

Toxins from the venoms of scorpion, snake, and spider are valuable tools to probe the structure–function relationship of ion channels. In this investigation, a new toxin gene encoding the peptide ImKTx1 was isolated from the venom gland of the scorpion Isometrus maculates by constructing cDNA library method, and the recombinant ImKTx1 peptide was characterized physiologically. The mature peptide of ImKTx1 has 39 amino acid residues including six cross‐linked cysteines. The electrophysiological experiments showed that the recombinant ImKTx1 peptide had a pharmacological profile where it inhibited Kv1.3 channel currents with IC50 of 1.70 n± 1.35 µM, whereas 10 µM rImKTx1 peptide inhibited about 40% Kv1.1 and 42% Kv1.2 channel currents, respectively. In addition, 10 µM rImKTx1 had no effect on the Nav1.2 and Nav1.4 channel currents. Multiple sequence alignments showed that ImKTx1 had no homologous toxin peptide, but it was similar with Ca2+ channel toxins from scorpion and spider in the arrangement of cysteine residues. These results indicate that ImKTx1 is a new Kv1.3 channel blocker with a unique primary structure. Our results indicate the diversity of K+ channel toxins from scorpion venoms and also provide a new molecular template targeting Kv1.3 channel. © 2011 Wiley Periodicals, Inc. J Biochem Mol Toxicol 25:244–251, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/jbt.20382
Neurodegeneration by activated microglia across a nanofiltration membrane
Authors: Graber David J. , Snyder‐Keller Abigail , Lawrence David A. , Turner James N.
Published: February 2011

Microglia have been implicated in the pathogenesis of several neurodegenerative diseases, but their precise role remains elusive. Although neuron loss in the presence of lipopolysaccharide‐stimulated microglia has been well documented, a novel coculture paradigm was developed as a new approach to assess the diffusible, soluble mediators of neurodegeneration. Isolated microglia were plated on membrane inserts that were coated with a layer of cellulose acetate. The cellulose acetate–coated membranes have nanofiltration properties, in that only molecules with masses less than 350 Da can pass through. Products released from activated microglia that were separated from primary ventral mesencephalon cells beneath the nanofiltering membrane were able to kill the dopamine neurons. Microglial cytokines cannot diffuse through this separating membrane. Addition of a nitric oxide synthase inhibitor prevented the loss of the dopamine neurons. These data describe a novel coculture system for studying diffusible factors and further support nitric oxide production as an important mediator in microglia‐induced neuron death. © 2011 Wiley Periodicals, Inc. J Biochem Mol Toxicol 26:45–53 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/jbt.20384
Effect of mitochondrial dysfunction and oxidative stress on endogenous levels of coenzyme Q10 in human cells
Authors: Yen Hsiu‐Chuan , Chen Feng‐Yuan , Chen Shih‐Wei , Huang Yu‐Hsiang , Chen Yun‐Ru , Chen Chih‐Wei
Published: February 2011

Little is known about the regulation of endogenous CoQ10 levels in response to mitochondrial dysfunction or oxidative stress although exogenous CoQ10 has been extensively used in humans. In this study, we first demonstrated that acute treatment of antimycin A, an inhibitor of mitochondrial complex III, and the absence of mitochondrial DNA suppressed CoQ10 levels in human 143B cells. Because these two conditions also enhanced formation of reactive oxygen species (ROS), we further investigated whether oxidative stress or mitochondrial dysfunction primarily contributed to the decrease of CoQ10 levels. Results showed that H2O2 augmented CoQ10 levels, but carbonyl cyanide‐p‐trifluoromethoxyphenylhydrazone (FCCP), a chemical uncoupler, decreased CoQ10 levels in 143B cells. However, H2O2 and FCCP both increased mRNA levels of multiple COQ genes for biosynthesis of CoQ10. Our findings suggest that ROS induced CoQ10 biosynthesis, whereas mitochondrial energy deficiency caused secondary suppression of CoQ10 levels possibly due to impaired import of COQ proteins into mitochondria. © 2011 Wiley Periodicals, Inc. J Biochem Mol Toxicol 25:280–289, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/jbt.20387
Change in self‐protect ion and symptoms after dynamic psychotherapy: the influence of pretreatment motivation
Authors: Marble Alice , Høglend Per , Ulberg Randi
Published: February 2011

The First Experimental Study of Transference‐interpretations (FEST) is a dismantling, randomized clinical trial of the long‐term effects of transference interpretation. This article looks at the influence of motivation on the ability to self‐protect and symptoms. Patients were randomized to receive a moderate level of transference interpretations or no transference interpretation. Assessments were made at pretreatment, midtreatment, posttreatment, and at two follow‐ups. The outcome measure, change in ability to self‐protect, was cluster 4 of the Structural Analysis of Social Behavior (SASB) Long Form Intrex Introject Questionnaire, a measure close to the SASB‐coded treatment process. Symptom change (SCL‐90) was also analyzed. Pretreatment motivation was a significant moderator of change in the ability to self‐protect and in symptom distress. Those with low motivation had a significant, positive, and long‐term treatment effect of transference interpretation. Patients with low motivation showed a significant, negative effect of transference interpretation. © 2011 Wiley Periodicals, Inc. J Clin Psychol 67:1–13, 2011.
Role of sensitivity to anxiety symptoms in responsiveness to mindfulness versus suppression strategies for coping with smoking cravings
Authors: Rogojanski Jenny , Vettese Lisa C. , Antony Martin M.
Published: February 2011

Mindfulness strategies for managing cravings involve present‐moment, nonjudgmental awareness of cravings without acting on them, while suppression involves pushing cravings out of awareness. Few studies have investigated individual differences in responding to these strategies. The current study examined whether individual differences in anxiety sensitivity moderate responsiveness to mindfulness versus suppression for coping with smoking cravings. Participants (N=61) utilized a mindfulness or suppression strategy to manage cravings during cue exposure to cigarettes and were evaluated for self‐efficacy 7 days later. Greater anxiety sensitivity after cue exposure was associated with increased self‐efficacy in the suppression condition. This suggests that anxiety‐sensitive individuals who utilize suppression may cope better with cravings, at least in the early days after learning these strategies. © 2011 Wiley Periodicals, Inc. J Clin Psychol 67:1–7, 2011.
Distributing vertices on Hamiltonian cycles
Authors: Faudree Ralph J. , Gould Ronald J. , Jacobson Michael S. , Magnant Colton
Published: February 2011

Let G be a graph of order n and 3≤t≤n/4 be an integer. Recently, Kaneko and Yoshimoto [J Combin Theory Ser B 81(1) (2001), 100–109] provided a sharp δ(G) condition such that for any set X of t vertices, G contains a hamiltonian cycle H so that the distance along H between any two vertices of X is at least n/2t. In this article, minimum degree and connectivity conditions are determined such that for any graph G of sufficiently large order n and for any set of t vertices X⊆V(G), there is a hamiltonian cycle H so that the distance along H between any two consecutive vertices of X is approximately n/t. Furthermore, the minimum degree threshold is determined for the existence of a hamiltonian cycle H such that the vertices of X appear in a prescribed order at approximately predetermined distances along H. © 2011 Wiley Periodicals, Inc. J Graph Theory 69: 28–45, 2012
Vizing's conjecture: a survey and recent results
Authors: Brešar, Boštjan , Dorbec, Paul , Goddard, Wayne , Hartnell, Bert L. , Henning, Michael A. , Klavžar, Sandi , Rall and Douglas F.
Published: February 2011

Vizing's conjecture from 1968 asserts that the domination number of the Cartesian product of two graphs is at least as large as the product of their domination numbers. In this paper we survey the approaches to this central conjecture from domination theory and give some new results along the way. For instance, several new properties of a minimal counterexample to the conjecture are obtained and a lower bound for the domination number is proved for products of claw‐free graphs with arbitrary graphs. Open problems, questions and related conjectures are discussed throughout the paper. © 2011 Wiley Periodicals, Inc. J Graph Theory 69: 46–76, 2012
Extremal graphs having no matching cuts
Authors: Bonsma Paul , Farley Arthur M. , Proskurowski Andrzej
Published: February 2011

A graph G = (V, E) is matching immune if there is no matching cut in G. We show that for any matching immune graph G, |E|≥⌈3(|V|−1)/2⌉. This bound is tight, as we define operations that construct, from a given vertex, exactly the class of matching immune graphs that attain the bound. © 2011 Wiley Periodicals, Inc. J Graph Theory 69:206‐222, 2012
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Synthesis and properties of oligonucleotides that contain a triazole‐linked nucleic acid dimer
Authors: Efthymiou Tim C. , Desaulniers Jean‐Paul
Published: February 2011

New chemically modified oligonucleotides at the site of the backbone are needed to improve the properties of oligonucleotides. A practical synthesis for a triazole‐linked nucleoside dimer based on a PNA‐like structure has been developed. This involves synthesizing two uracil‐based monomers that contain either an azide or an alkyne functionality, followed by copper‐catalyzed 1,3‐dipolar cycloaddition. This dimer was incorporated within an oligonucleotide via phosphoramidite chemistry and UV‐monitored thermal denaturation data illustrates slight destabilization relative to its target complementary sequence. This chemically modified dimer will allow for a future investigation of its properties within DNA and RNA‐based applications. J. Heterocyclic Chem., (2011).
Using mobile phones to collect panel data in developing countries
Authors: Dillon Brian
Published: February 2011

The rapid spread of mobile telephony throughout the developing world offers researchers a new and exciting means of data collection. This paper describes and analyses the experience of a research project that used mobile phones to collect high frequency, quantitative economic data from households in rural Tanzania. I discuss the research design, highlight some of the mistakes made and lessons learned, and speculate on the applicability of this method in other settings. Copyright © 2011 John Wiley & Sons, Ltd.
Vibratory behavior reduction of electrical machines through materials properties evaluation
Authors: Ferkha N. , Mekideche M. R. , Torregrossa D. , Djerdir A. , Miraoui A. , Peyraut F.
Published: February 2011

Most of the electromagnetic devices, especially electrical machines, have the disadvantage to be exposed to high vibrations caused by magnetic forces. The aim of this study is to propose a methodology to optimize the cylindrical stators generally used in electrical machines regarding the vibration phenomena. Techniques for vibration reduction require knowledge of the proper frequencies, which depend on mechanical shapes and dimensions as well as material properties such as mass density, Young's modulus and Poisson's ratio. This paper proposes a new approach which is based on the identification of mass density (lamination stacking factor) and Young's modulus in the goal to minimize the vibratory behavior of electrical machines. In this goal, we have used artificial intelligent and finite element method (FEM) analysis to solve the magneto‐mechanical inverse problem (IP). In the proposed approach, a Multilayer Perceptron Neural Network (MLPNN) is used as a forward model in order to decrease the FEM time consuming. Thus, a Genetic Algorithm (GA) is used to solve the IP in a reasonable time of running. An example study of an induction machine proves that the developed approach may be applied in both design and identification applications. Copyright © 2011 John Wiley & Sons, Ltd.
Air circulation and its impact on microclimatic variables in the Císařská Cave (Moravian Karst, Czech Republic)
Authors: Faimon Jiří , Troppová Dana , Baldík Vít , Novotný Roman
Published: February 2011

Airflows and their impact on microclimatic parameters were studied in the two‐entranced Císařská Cave (Moravian Karst, Czech Republic). Basing on the airflow direction with respect to the upper entrance (UE) and lower entrance (LE), three ventilation modes were distinguished: upward airflow one (UAF mode), downward airflow one (DAF mode), and transitional mode. A switching between the UAF and DAF happens in the transitional mode, in the range of external temperatures from 9.5 to 11.1 °C. Basing on the extent of cave ventilation, a period of active ventilation and period of stagnant ventilation were recognised. The cave air is intensively exchanged with external airs during the active ventilation period when the cave persists in either the DAF or UAF mode. During the stagnant ventilation period, the single airflow modes switch during diurnal cycle and only cave entering passages are vented (impacted). The airflows were found to depend (i) linearly on the differences in cave‐outdoor air densities, (ii) nonlinearly on the external temperature, and (iii) both linearly (LE) and non‐linearly (UE) on the temperature gradient. Majority of the airflows showed high‐frequency oscillations with the period from tens of seconds to minutes and with the amplitude up to 0.1 m3 s−1. Different airflow spectra were found at the individual entrances. The highest spectral densities were registered at low driving forces. The air circulation changed the pattern of temperature distribution depending on the ventilation mode and ventilation period. The cave relaxation length varied in the extreme range from 1 to 69.6 m. The asymptotic temperature and asymptotic specific humidity varied from 7.5 to 11.8 °C, and from 5.47 to 7.15 kg kg−1, respectively. The impact of airflows on the cave CO2 levels is discussed based on a dynamic model. Copyright © 2011 Royal Meteorological Society
Simulation of North American lake‐ice cover characteristics under contemporary and future climate conditions
Authors: Dibike Yonas , Prowse Terry , Bonsal Barrie , Rham Laurent de , Saloranta Tuomo
Published: February 2011

Freshwater ice plays an important role in physical, biological, and chemical processes affecting cold‐region lakes. To examine the potential magnitude of climate‐change‐related impacts in ice‐cover characteristics, particularly its formation, duration, breakup, thickness, and structural composition over North America, this study employs a one‐dimensional, process‐based, lake simulation model, ‘MyLake’ (Multi‐year simulation model for Lake thermo‐ and phytoplankton dynamics). The model is first calibrated and validated for Baker Lake, Nunavut, Canada, and then used to simulate patterns of ice conditions using a set of hypothetical lakes of varying depth (5, 20, and 40 m) located at a 2° latitude/longitude grid pattern for the major cold‐region portion of North America between 40 and 75° latitude. The model is driven by gridded atmospheric forcing data from the North American Regional Reanalysis (NARR) and the Canadian Regional Climate Model (CRCM) with projections of future climate corresponding to the SRES A2 emissions scenario. The NARR‐based simulation results for the period 1979–2006 are consistent with observations of lake‐ice thickness and phenology obtained from the Canadian Ice Database. The CRCM‐based lake‐ice simulation results for the baseline (1961–1990) and future (2041–2070) time periods indicate that projected air‐temperature warming will advance break‐up by 10–20 days and delay freeze‐up by 5–15 days, thereby reducing lake‐ice duration by about 15–35 days. Lake depth is also found to have significant influence on lake‐ice freeze‐up dates and maximum thicknesses but not on the break‐up dates. Such changes are accompanied by a reduction in ice thickness of 10–30 cm. Cover composition is also altered as a result of changes in ice thickness and snow loading resulting in somewhat greater thicknesses of white‐ice (1–5 cm) over most areas except towards the east and west coasts, as well as more southerly latitudes where it slightly decreased. Implications of such cover changes are also discussed. Copyright © 2011 Royal Meteorological Society and Crown in the right of Canada.
Comparative in vivo study of injectable biomaterials combined with BMP for enhancing tendon graft osteointegration for anterior cruciate ligament reconstruction
Authors: Pan Weimin , Wei Yiyong , Zhou Li , Li Dan
Published: February 2011

This study was to compare effect of osteointegration of grafted tendon in bone tunnels between injected calcium phosphate cement (ICPC) and injected fibrin sealant (IFS) combined with bone morphogenetic protein (BMP) after anterior cruciate ligament (ACL) reconstruction. ACL reconstruction was performed bilaterally in 51 rabbits. ICPC‐BMP composite was injected into one knee, with the contralateral knee IFS–BMP composite. The rabbits were killed at postoperative weeks 2, 6, and 12 for testing. Histological observations showed the ICPC composite gradually increased the new bone formation during the whole healing process, while the IFS composite had a burst effect on enhancing the healing of tendon‐to‐bone at 2 and 6 weeks. By 12 weeks, there was more new cartilage and new bone in the interface in the ICPC‐bBMP group. Micro‐CT showed that the values of BMD in the ICPC‐bBMP group were lower than those in the IFS‐bBMP group at 6 weeks, while the values in the ICPC‐bBMP group were higher than those in the IFS‐bBMP group at 12 weeks (p > 0.05). Fluorescent labels showed that the rate of new bone formation of IFS–BMP composite was significantly higher than that of ICPC composite at 6 weeks (3.45 ± 0.62 µm/day vs. 2.93 ± 0.51 µm/day), but the rate was decreased compared with ICPC composite at 12 weeks (2.58 ± 0.72 µm/day vs. 3.05 ± 0.68 µm/day; p < 0.05). Biomechanically, the ultimate failure load in the ICPC‐BMP group was always higher than that in the IFS–BMP group. It is evident that the ICPC composite achieved a more prolonged osteogenic effect than that by IFS composite. © 2011 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 29: 1015–1021, 2011
Restoration of anterior–posterior rotator cuff force balance improves shoulder function in a rat model of chronic massive tears
Authors: Hsu Jason E. , Reuther Katherine E. , Sarver Joseph J. , Lee Chang Soo , Thomas Stephen J. , Glaser David L. , Soslowsky Louis J.
Published: February 2011

The rotator cuff musculature imparts dynamic stability to the glenohumeral joint. In particular, the balance between the subscapularis anteriorly and the infraspinatus posteriorly, often referred to as the rotator cuff “force couple,” is critical for concavity compression and concentric rotation of the humeral head. Restoration of this anterior–posterior force balance after chronic, massive rotator cuff tears may allow for deltoid compensation, but no in vivo studies have quantitatively demonstrated an improvement in shoulder function. Our goal was to determine if restoring this balance of forces improves shoulder function after two‐tendon rotator cuff tears in a rat model. Forty‐eight rats underwent detachment of the supraspinatus and infraspinatus. After four weeks, rats were randomly assigned to three groups: no repair, infraspinatus repair, and two‐tendon repair. Quantitative ambulatory measures including medial/lateral forces, braking, propulsion, and step width were significantly different between the infraspinatus and no repair group and similar between the infraspinatus and two‐tendon repair groups at almost all time points. These results suggest that repairing the infraspinatus back to its insertion site without repair of the supraspinatus can improve shoulder function to a level similar to repairing both the infraspinatus and supraspinatus tendons. Clinically, a partial repair of the posterior cuff after a two‐tendon tear may be sufficient to restore adequate function. An in vivo model system for two‐tendon repair of massive rotator cuff tears is presented. © 2011 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 29: 1028–1033, 2011
Don't hedge your bets: Hedgehog signaling as a central mediator of endochondral bone development and cartilage diseases
Authors: Rockel Jason S. , Alman Benjamin A.
Published: February 2011

Cell differentiation and patterning are vital processes in the development of the appendicular skeleton. The hedgehog (Hh) signaling pathway plays a central role in regulating the anterior–posterior axis of the distal limb as well as the length of endochondral bones. Ligand‐induced Hh signaling inhibits the processing of the Gli transcription factors from activator to repressor isoforms. In the growth plate, Indian hedgehog inhibits Gli processing, resulting in accumulation of Gli activators that induce chondrocyte maturation and hypertrophic differentiation. Parathyroid hormone‐like hormone promote and Gli processing to repressor forms, thus regulating the rate of hypertrophic differentiation. In cartilage diseases such as osteoarthritis and cartilage tumors, there is a recapitulation of developmental processes that involve increased Hh signaling. Studies have shown that pharmacological inhibitors of Hh signaling can attenuate the progression osteoarthritis and cartilage tumor growth. Thus, Hh blockade can serve as a potential therapy for the treatment of various cartilage diseases. © 2011 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 29:810–815
Morphological evolution of the Guadiana estuary and intertidal zone in response to projected sea‐level rise and sediment supply scenarios
Authors: Sampath Dissanayake M.R. , Boski Tomasz , Silva Patricia L. , Martins Flavio A.
Published: February 2011

Analysis of Holocene sediment accumulation in the Guadiana estuary (southern Portugal) during sea‐level rise since ca. 13 cal. ka BP was used to simulate the long‐term morphological evolution of the lower Guadiana estuary and the associated intertidal zone for 21st‐century predicted sea‐level rises. Three sea‐level rise scenarios given by the IPCC (2007) were used in the simulations of morphology using a large‐scale behaviour‐oriented modelling approach. Sedimentation rate scenarios were derived both from the Holocene evolution of the estuary and from a semi‐empirical estimation of present‐day sediment aggradation. Our results show that the net lateral expansion of the intertidal zone area would be about 3–5% of the present intertidal zone area for each 10 cm rise in sea level. Under constraints imposed by the lack of fluvial sediment supply, the lateral expansion of the landward boundary of the intertidal zone will occur mainly in the Portuguese margin of the Guadiana estuary, while submergence of the salt marshes will occur in the Spanish margin. Therefore the Spanish margin is highly vulnerable to both sea‐level rise and lack of sediment supply. Copyright © 2011 John Wiley & Sons, Ltd.
Vegetation changes in the Neotropical Gran Sabana (Venezuela) around the Younger Dryas chron
Authors: Montoya Encarni , Rull Valenti , Stansell Nathan D. , Bird Broxton W. , Nogué Sandra , Vegas‐vilarrúbia Teresa , Abbott Mark B. , Díaz Wilmer A.
Published: February 2011

The occurrence of the Younger Dryas cold reversal in northern South America midlands and lowlands remains controversial. We present a palaeoecological analysis of a Late Glacial lacustrine section from a midland lake (Lake Chonita, 4.6501 °N, 61.0157 °W, 884 m elevation) located in the Venezuelan Gran Sabana, based on physical and biological proxies. The sediments were mostly barren from ∼15.3 to 12.7 k cal a BP, probably due to poor preservation. A ligneous community with no clear modern analogues was dominant from 12.7 to 11.7 k cal a BP (Younger Dryas chronozone). At present, similar shrublands are situated around 200 m elevation above the lake, suggesting a cooling‐driven downward shift in vegetation during that period. The interval from 11.7 to 10.6 k cal a BP is marked by a dramatic replacement of the shrubland by savannas and a conspicuous increase in fire incidence. The intensification of local and regional fires at this interval could have played a role in the vegetation shift. A change to wetter, and probably warmer, conditions is deduced after 11.7 k cal a BP, coinciding with the early Holocene warming. These results support the hypothesis of a mixed origin (climate and fire) of the Gran Sabana savannas, and highlight the climatic instability of the Neotropics during the Late Glacial. Copyright © 2011 John Wiley & Sons, Ltd.
Late Pleistocene snowline fluctuations at Nevado Coropuna (15°S), southern Peruvian Andes
Authors: Bromley Gordon R.M. , Hall Brenda L. , Rademaker Kurt M. , Todd Claire E. , Racovteanu Adina E.
Published: February 2011

Deposits preserved on peaks in the southern Peruvian Andes are evidence for past glacial fluctuations and, therefore, serve as a record of both the timing and magnitude of past climate change. Moraines corresponding to the last major expansion of ice on Nevado Coropuna date to 20‐25 ka, during the last glacial maximum. We reconstructed the snowline at Coropuna for this period using a combined geomorphic‐numeric approach to provide a first‐order estimate of the magnitude of late‐Pleistocene climate change. Our reconstructions show that snowline was approximately 550‐770 m lower during the last glacial maximum than during the late Holocene maximum, which ended in the 19th century, and ∼750 m lower than today. While these values are similar to data from nearby Nevado Solimana, reconstructions from the neighbouring peak of Nevado Firura reveal a smaller snowline depression, suggesting the glacial response to climate forcing in the tropics is strongly influenced by non‐climatic factors. These data constitute some of the first directly dated palaeo‐snowline data from the arid tropics and suggest that the magnitude of the last glaciation in at least parts of the tropical Andes was similar to late‐Pleistocene events at higher latitudes. Copyright © 2011 John Wiley & Sons, Ltd.
CASP8 −652 6N del and CASP8 IVS12‐19G>A gene polymorphisms and susceptibility/prognosis of ESCC: A case control study in northern Indian population
Authors: Umar Meenakshi , Upadhyay Rohit , Kumar Shaleen , Ghoshal Uday Chand , Mittal Balraj
Published: February 2011

Background

Caspase8 influences carcinogenesis through regulation of apoptosis, hyperproliferation, and metastasis. Role of genetic variations in caspase8 has been explored in various cancers; however, their predictive and prognostic role in esophageal cancer is poorly understood.

Methods

We investigated the association of two potential caspase8 polymorphisms: CASP8 −652 6N del and CASP8 IVS12‐19 G>A polymorphisms with susceptibility and survival of 259 esophageal squamous cell carcinoma (ESCC) cases and 259 cancer‐free controls from northern Indian population using PCR/PCR RFLP method.

Results

CASP8 IVS12‐19 AA genotype was found to be associated with significant increased risk of ESCC (odds ratio (OR) 3.28, 95% confidence interval (CI) 1.04–10.29) specifically in male subjects (OR 3.71, 95% CI 1.01–13.35) with lower third tumor anatomical location (OR 6.00, 95% CI 1.60–22.55). Kaplan–Meier and Cox Regression analysis showed lower median survival (7.13 months vs. 25.21 months) and greater hazard of death (HR 3.40, 95% CI 1.38–7.90) with CASP8 IVS12‐19 AA genotype in ESCC cases compared to IVS12‐19 GG genotype. However, no association of CASP8 −652 6N del polymorphism with susceptibility and prognosis of ESCC was observed.

Conclusion

CASP8 IVS12‐19 G>A but not CASP8 −652 6N del polymorphism may modulate risk of ESCC and its survival outcome in northern Indian population. J. Surg. Oncol. 2011;103:716–723. © 2011 Wiley‐Liss, Inc.
Resource loss and posttraumatic responses in Bedouin members of the Israeli Defense Forces
Authors: Slobodin Ortal , Caspi Yael , Klein Ehud , Berger Barry D. , Hobfoll Stevan E.
Published: February 2011

This study examined the impact of exposure to traumatizing events in an ethnic minority group of Bedouin members of the Israel Defense Forces (N = 317). Guided by the conservation of resources (COR) theory (Hobfoll, 1988), the authors hypothesized that loss of resources would mediate the relationship between trauma and posttraumatic responses. We found that loss of personal resources (e.g., self‐esteem, self‐mastery) was the best predictor of psychological distress among traumatized Bedouin servicemen. Our findings suggest the significance of personal resources within collectivist communities in coping with trauma and maintaining resilience. This study contributes to the understanding of the ethnocultural aspects of trauma and the potential interventions that may be tailored for minority groups.
Gossypiboma: An unusual intracranial complication of endoscopic sinus surgery
Authors: Tan Vincent Eng Soon , Sethi Dharambir Singh
Published: February 2011

We report a case of a 52‐year‐old man who presented with iatrogenic bilateral nasoethmoidal meningoencephaloceles following endoscopic nasal surgery performed in a neighboring country 8 years ago. Imaging studies, including computed tomography and magnetic resonance imaging of the paranasal sinuses and anterior skull base, demonstrated bilateral meningoencephaloceles and a suspicious intracranial lesion. In view of the intracranial lesion and size of the skull base defect, an external approach via a bicoronal flap was used for exploration and repair. Intraoperative findings revealed the suspicious intracranial lesion to be a retained piece of gauze. The patient underwent a successful removal of the foreign body and repair of the skull base defect. Postoperative recovery was uneventful. To our knowledge, an iatrogenic intracranial foreign body following an endonasal endoscopic procedure has never been reported before. Laryngoscope, 2011
Correlations between symptoms, nasal endoscopy, and in‐office computed tomography in post‐surgical chronic rhinosinusitis patients
Authors: Ryan William R. , Ramachandra Tara , Hwang Peter H.
Published: February 2011

Objectives:

To determine correlations between symptoms, nasal endoscopy findings, and computed tomography (CT) scan findings in post‐surgical chronic rhinosinusitis (CRS) patients.

Study Design:

Cross‐sectional.

Material and Methods:

A total of 51 CRS patients who had undergone endoscopic sinus surgery (ESS) completed symptom questionnaires, underwent endoscopy, and received an in‐office sinus CT scan during one clinic visit. For metrics, we used the Sinonasal Outcomes Test‐20 (SNOT‐20) questionnaire, visual analog symptom scale (VAS), Lund‐Kennedy endoscopy scoring scale, and Lund‐MacKay (LM) CT scoring scale. We determined Pearson correlation coefficients, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) between scores for symptoms, endoscopy, and CT.

Results:

The SNOT‐20 score and most VAS symptoms had poor correlation coefficients with both endoscopy and CT scores (0.03–0.24). Nasal drainage of pus, nasal congestion, and impaired sense of smell had moderate correlation coefficients with endoscopy and CT (0.24–0.42). Endoscopy had a strong correlation coefficient with CT (0.76). Drainage, edema, and polyps had strong correlation coefficients with CT (0.80, 0.69, and 0.49, respectively). Endoscopy had a PPV of 92.5% and NPV of 45.5% for detecting an abnormal sinus CT (LM score ≥1).

Conclusions:

In post‐ESS CRS patients, most symptoms do not correlate well with either endoscopy or CT findings. Endoscopy and CT scores correlate well. Abnormal endoscopy findings have the ability to confidently rule in the presence of CT opacification, thus validating the importance of endoscopy in clinical decision making. However, a normal endoscopy cannot assure a normal CT. Thus, symptoms, endoscopy, and CT are complementary in the evaluation of the post‐ESS CRS patient. Laryngoscope, 2011
Preliminary investigation of adjustable balloon implant for type I thyroplasty
Authors: Hoffman Matthew R. , Witt Rachel E. , McCulloch Timothy M. , Jiang Jack J.
Published: February 2011

Objective:

We present the adjustable balloon implant (ABI), a novel implant to be used in type I thyroplasty for the treatment of vocal fold paralysis. The ABI offers the same medialization provided by other implants, but can easily be catered to individual patient anatomy as well as modified postoperatively without the need for a revision thyroplasty.

Study Design:

Repeated measures with each larynx serving as its own control.

Methods

Medialization thyroplasty (MT) with the ABI was performed on five excised canine larynges. Mucosal wave, aerodynamic, and acoustic parameters were measured for three conditions: normal; right vocal fold paralysis; and paralysis with the ABI.

Results:

Insertion of the ABI resulted in significant decreases in both phonation threshold pressure and phonation threshold flow. Perturbation parameters of percent jitter and percent shimmer were also significantly decreased and restored to normal levels. Signal‐to‐noise ratio was significantly increased to the normal level as well. The mucosal wave was preserved after implant insertion.

Conclusions:

This preliminary experiment showing significant improvements in aerodynamic and acoustic parameters demonstrates the potential of the ABI as a thyroplasty implant. Effective medialization and preservation of the mucosal wave combined with postoperative adjustability makes it a potentially valuable clinical device. Laryngoscope, 2011
Novel use of unilateral galeopericranial flaps for closure of sino‐orbital cutaneous fistulas
Authors: Mehta Vikas , Alon Eran E. , Buchbinder Daniel , Urken Mark L.
Published: February 2011

Sino‐orbital cutaneous fistulas are a well‐documented complication of orbital exenteration and sinonasal carcinoma resection. Challenges to successful closure of this common complication include complex anatomy, communication with sinonasal mucosa, persistent mucopurulent drainage, compromised wound healing due to previous irradiation, and wound infection. We describe a novel approach for closure of sino‐orbital cutaneous fistulas in two patients using a galeopericranial flap. The galeopericranial flap is ideal due to its thin, pliable nature and predictable, abundant vascularity. Additionally, it obviates the need for a more cosmetically disfiguring closure. Although used successfully in a variety of skull base and ophthalmologic surgeries, the galeopericranial flap has not been previously described for closure of sino‐orbital cutaneous fistulas. Both patients' defects have remained closed at follow‐up with excellent cosmetic results. Laryngoscope, 2011
The effect of corticosteroid on metalloproteinase levels of nasal polyposis 1
Authors: Yigit Özgür , Acioğlu Engin , Gelişgen Ramisa , Server Ela A. , Azizli Elad , Uzun Hafize
Published: February 2011

Objectives:

The aim of this study was to investigate the effect of corticosteroid treatment on topical and systemic metalloproteinase levels of patients with nasal polyposis (NP).

Study Design:

Prospective clinical trial.

Methods:

The study included patients undergoing a paranasal sinus operation due to NP. Oral corticosteroid therapy was performed on all patients before endoscopic sinus surgery. Endoscopic and radiological evaluation were performed and nasal tissue specimens and venous blood samples were collected before (preop phase) and after corticosteroid treatment (periop phase) and also one month after surgery (postop phase). Endoscopic and computed tomography scan findings were scored adequately and all tissue and blood samples were examined cumulatively.

Results:

The study included 27 patients with inflammatory NP. Preop tissue matrix metalloproteinase‐2 (MMP‐2) levels were found to be significantly lower than preop and postop concentrations. In contrast, periop serum MMP‐2 levels were found to be significantly higher than preop and postop concentrations. Periop tissue inhibitor of metalloproteinase‐1 (TIMP‐1) levels were also found to be significantly lower than preop and postop concentrations, similar to MMP‐2 tissue concentrations. However, there was no statistical difference among tissue MMP‐9 concentrations of the three phases. In addition, there was also no statistical difference among serum MMP‐9 levels of the three phases.

Conclusions:

Oral corticosteroid treatment especially reduces tissue MMP‐2, then TIMP‐1. Severity of nasal polyposis primarily correlates with increasing tissue MMP‐2/TIMP‐1 ratio, then MMP‐9/TIMP‐1. These results suggest that selective inhibition for MMP‐2 and activation for TIMP‐1 might be a novel therapeutic strategy for patients with nasal polyposis. Laryngoscope, 2011
Synthesis of Poly(propylene glycol)‐block‐Polyethylenimine Triblock Copolymers for the Delivery of Nucleic Acids
Authors: Brissault Blandine , Leborgne Christian , Scherman Daniel , Guis Christine , Kichler Antoine
Published: February 2011

LPEIs, which are efficient DNA transfection agents, were found to be far less effective for the delivery of siRNAs. Here, two amphiphilic triblock copolymers LPEI50‐b‐PPG36‐b‐LPEI50 (2) and LPEI14‐b‐PPG68‐b‐LPEI14 (4) have been synthesized. The transfection assays showed that compound 2 was efficient for DNA transfection whilst it was almost inactive for siRNA delivery. In contrast, polymer 4 was inefficient for DNA transfection while it showed capabilities for siRNA delivery. Taken together, our results indicate that the properties required for DNA and siRNA delivery are different. Moreover, we show that introduction of a hydrophobic segment that allows self‐assembly confers siRNA delivery capacities.

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Enhancing Redox Stability and Electrochromic Performance of Polyhydrazides and Poly(1,3,4‐oxadiazole)s with 3,6‐Di‐tert‐butylcarbazol‐9‐yltriphenylamine Units
Authors: Hsiao Sheng‐Huei , Wang Hui‐Min , Guo Wenjeng , Sun Chieh‐Hsiang
Published: February 2011

New polyhydrazides and poly(amidehydrazide)s bearing redox‐active carbazole and triphenylamine units were prepared. The resulting poly(1,3,4‐oxdiazole)s and poly(amide‐1,3,4‐oxadiazole)s had high glass‐transition temperatures (288–330 °C) and high thermal stability. The dilute solutions of all the hydrazide and oxadiazole polymers showed a weak–medium photoluminescence with emission maxima around 474–506 nm. The polymer films revealed two well‐defined and reversible redox couples upon electrochemical oxidation, together with interesting electrochromic behaviors. They showed enhanced redox‐stability and electrochromic performance. CV of the oxadiazole polymers also showed reduction processes due to the formation of radical anions of the oxadiazole units.

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Toward Gradient Formation in Microfluidic Devices by using Slanted Ridges
Authors: van Schijndel Twan , Singh Mrityunjay K. , Gillies Murray , Kahya Nicoletta , Kharin Aleksey , den Toonder Jaap M. J.
Published: February 2011

Some lab‐on‐a‐chip applications require to establish a controlled spatial concentration gradient of (chemical) species, for example for iso‐electrical focusing or to study chemotactic properties of cells. We show that covering a microchannel floor with special grooves or ridges, well‐controlled concentration gradients can be created, depending on the geometrical design of the grooves or ridges. In our case, the pattern consists of ridges that are slanted with respect to the main channel direction. Similar patterns have been applied in the past to achieve mixing by introducing chaotic advection. We present experimental and numerical results that prove the mixing effectiveness of the ridges. In addition, making use of the local mixing capabilities of the ridge patterns, we show, using numerical simulations, how to achieve a concentration gradient across a microfluidic channel.

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