bluuebunny/crossref_metadata_2025 huggingface dataset:
Hepatocytes Do Not Undergo Epithelial-Mesenchymal Transition in Liver Fibrosis in Mice
Authors: Taura Kojiro , Miura Kouichi , Iwaisako Keiko , Österreicher Christoph H. , Kodama Yuzo , Penz-Österreicher Melitta , Brenner David A.
Published: October 2009

The origin of fibrogenic cells in liver fibrosis remains controversial. We assessed the emerging concept that hepatocytes contribute to production of extracellular matrix (ECM) in liver fibrosis through epithelial-mesenchymal transition (EMT). We bred triple transgenic mice expressing ROSA26 stop β-galactosidase (β-gal), albumin Cre, and collagen α1(I) green fluorescent protein (GFP), in which hepatocyte-derived cells are permanently labeled by β-gal and type I collagen-expressing cells are labeled by GFP. We induced liver fibrosis by repetitive carbon tetrachloride (CCl4) injections. Liver sections and isolated cells were evaluated for GFP and β-gal as well as expression of α-smooth muscle actin (α-SMA) and fibroblast-specific protein 1 (FSP-1). Upon stimulation with transforming growth factor β-1, cultured hepatocytes isolated from untreated liver expressed both GFP and β-gal with a fibroblast-like morphological change but lacked expression of other mesenchymal markers. Cells from CCl4-treated livers never showed double-positivity for GFP and β-gal. All β-gal-positive cells exhibited abundant cytoplasm, a typical morphology of hepatocytes, and expressed none of the mesenchymal markers including α-SMA, FSP-1, desmin, and vimentin. In liver sections of CCl4-treated mice, GFP-positive areas were coincident with fibrotic septa and never overlapped X-gal-positive areas.

Conclusion:

Type I collagen-producing cells do not originate from hepatocytes. Hepatocytes

in vivo

neither acquire mesenchymal marker expression nor exhibit a morphological change clearly distinguishable from normal hepatocytes. Our results strongly challenge the concept that hepatocytes

in vivo

acquire a mesenchymal phenotype through EMT to produce the ECM in liver fibrosis. (Hepatology 2009.)
An RBF‐based model with an information processor for forecasting hourly reservoir inflow during typhoons
Authors: Lin Gwo‐Fong , Wu Ming‐Chang , Chen Guo‐Rong , Tsai Fei‐Yu
Published: October 2009

Inflow forecasting is essential for decision making on reservoir operation during typhoons. In this paper, a radial basis function (RBF)‐based model with an information processor is proposed for more accurate forecasts of hourly reservoir inflow. Firstly, based on the multilayer perceptron neural (MLP) network, an information processor is developed to pre‐process the typhoon information (namely, typhoon characteristics and rainfall) and to produce forecasts of rainfall. The forecasted rainfall and the observed inflow are then used as input to the RBF‐based model, which is a nonlinear function approximator, to produce forecasts of hourly inflow. For parameter estimation of the RBF‐based model, the fully‐supervised learning algorithm is used. Actual applications of the proposed model are performed to yield 1‐ to 6‐h ahead forecasts of inflow. To assess the improvement due to the use of the typhoon information processor, models without the typhoon information processor are constructed and compared with the proposed model. The results show that the proposed model performs the best and is capable of providing improved forecasts of hourly inflow, especially for long lead‐time. In conclusion, the proposed model with a typhoon information processor can extract useful information from typhoon characteristics and rainfall, and consequently improve the forecasting performance. Copyright © 2009 John Wiley & Sons, Ltd.
EGFR variant‐mediated invasion by enhanced CXCR4 expression through transcriptional and post‐translational mechanisms
Authors: Rahimi Massod , George Jessica , Tang Careen
Published: October 2009

The expression of the potent, constitutively activated EGFR variant, EGFRvIII, has been linked to breast cancer metastasis, but the mechanisms of EGFRvIII and CXCR4 crosstalk, which may facilitate breast cancer invasion, have never been explored. Here we report that CXCR4 expression is increased in breast cancer cells expressing EGFRvIII regardless of the ER/PgR status of the cells. Treatment of EGFRvIII‐expressing breast cancer cells with the tyrosine kinase inhibitor, AG1478, reverses CXCR4 expression back to levels expressed in parental cells. In addition, expressing EGFRvIII enhances CXCL12/CXCR4‐mediated invasion, which can be inhibited by CXCR4 inhibitors. Surprisingly, CXCR4 mRNA and its transcriptional regulator, HIF‐1α, are up‐regulated only in ER+/PgR+ estrogen‐dependent EGFRvIII‐expressing breast cancer cells, but not in ER‐/PgR‐ or estrogen‐independent cell lines, suggesting that HIF‐1α and hormone receptor‐mediated actions may have a role in the transcriptional regulation of CXCR4. We also demonstrate that p38 MAPK is one of the major down‐stream signaling molecules responsible for EGFRvIII/CXCR4‐mediated invasion as p38 MAPK activity was induced by CXCL12 stimulation under both normoxic and hypoxic conditions. More interestingly, inhibition of p38 MAPK activity significantly reduced CXCR4 expression and inhibited the invasive potential of EGFRvIII‐expressing breast cancer cells, suggesting an essential role for p38 MAPK in EGFRvIII/CXCR4 induced invasion. Furthermore, CXCR4 is regulated post‐translationally through decreased expression of AIP4 and β‐arrestin 1/2, molecules involved in CXCR4 internalization, cellular trafficking and degradation. These results provide a plausible mechanism for EGFRvIII‐mediated invasion and establish a functional link between EGFRvIII and CXCR4 signaling pathways.
Overexpression of SPARC obliterates the in vivo tumorigenicity of human hepatocellular carcinoma cells
Authors: Atorrasagasti Catalina , Malvicini Mariana , Aquino Jorge B. , Alaniz Laura , Garcia Mariana , Bolontrade Marcela , Rizzo Manglio , Podhajcer Osvaldo L. , Mazzolini Guillermo
Published: October 2009

Hepatocellular carcinoma (HCC) is the sixth most common cancer and the third leading cause of cancer‐related death worldwide. Current treatments are extremely disappointing. SPARC (Secreted protein, acidic and rich in cysteine) is a matricellular glycoprotein with differential expression in several tumors, including HCC, which significance remains unclear. We infected HCC cells (HepG2, Hep3B and Huh7) with an adenovirus expressing SPARC (AdsSPARC) to examine the role of SPARC expression on HCC cells and its effect on tumor aggressiveness. The in vitro HCC cells substrate‐dependent proliferation and cell cycle profile were unaffected; however, SPARC overexpression reduced HCC proliferation when cells were grown in spheroids. A mild induction of cellular apoptosis was observed upon SPARC overexpression. SPARC overexpression resulted in spheroid growth inhibition in vitro while no effects were found when recombinant SPARC was exogenously applied. Moreover, the clonogenic and migratory capabilities were largely decreased in SPARC‐overexpressing HCC cells, altogether suggesting a less aggressive HCC cell phenotype. Consistently, AdsSPARC‐transduced cells showed increased E‐cadherin expression and a concomitant decrease in N‐cadherin expression. Furthermore, SPARC overexpression was found to reduce HCC cell viability in response to 5‐FU‐based chemotherapy in vitro, partially through induction of apoptosis. In vivo experiments revealed that SPARC overexpression in HCC cells inhibited their tumorigenic capacity and increased animal survival through a mechanism that partially involves host macrophages. Our data suggest that SPARC overexpression in HCC cells results in a reduced tumorigenicity partially through the induction of mesenchymal‐to‐epithelial transition (MET). These evidences point to SPARC as a novel target for HCC treatment.
Effect of photoinitiator system and water content on dynamic mechanical properties of a light‐cured bisGMA/HEMA dental resin
Authors: Park Jonggu , Ye Qiang , Topp Elizabeth M. , Misra Anil , Kieweg Sarah L. , Spencer Paulette
Published: October 2009

The selection of an appropriate photoinitiator system is critical for efficient polymerization of dental resins with satisfactory mechanical and physical properties. The purpose of this study was to evaluate the influence of adding an iodonium salt to two‐component photoinitiator systems. Four photoinitiator systems were included in a model bisGMA/HEMA resin and used to prepare samples at different water contents; the dynamic mechanical properties and the final degree of conversion of the samples were then characterized. Addition of the iodonium salt to the two‐component photoinitiator systems increased the final degree of conversion, glass transition temperature, rubbery modulus, and crosslink density. The photoinitiator system containing ethyl‐4‐(dimethylamino) benzoate as a coinitiator and the iodonium salt exhibited the highest rubbery modulus. The enhanced properties in the presence of the iodonium salt can be attributed to the production of an active phenyl radical with regeneration of the original camphorquinone, which may increase the compatibility between monomers and initiators, especially in the presence of water. The results support the hypothesis that a photoinitiator system containing an iodonium salt can increase both mechanical properties and final conversion of model resin polymerized in the presence of water. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res 2010
Comparison of active sites of butyrylcholinesterase and acetylcholinesterase based on inhibition by geometric isomers of benzene‐di‐N‐substituted carbamates
Authors: Chiou Shyh‐Ying , Huang Chuan‐Fu , Hwang Mei‐Ting , Lin Gialih
Published: October 2009

We have reported that benzene‐1,2‐, 1,3‐, and 1,4‐di‐N‐substituted carbamates (1–15) are characterized as the conformationally constrained inhibitors of acetylcholinesterase and mimic gauche, eclipsed, and anti‐conformations of acetylcholine, respectively (J Biochem Mol Toxicol 2007;21:348–353). We further report the inhibition of butyrylcholinesterase by these inhibitors. Carbamates 1–15 are also characterized as the pseudosubstrate inhibitors of butyrylcholinesterase as in the acetylcholinesterase catalysis. Benzene‐1,4‐di‐N‐n‐hexylcarbamate (12) and benzene‐1,4‐di‐N‐n‐octylcarbamate (13) are the two most potent inhibitors of butyrylcholinesterase among inhibitors 1–15. These two para compounds, with the angle of 180° between two C(benzene)O bonds, mimic the preferable anti CO/CN conformers for the choline ethylene backbone of butyrylcholine during the butyrylcholinesterase catalysis. The second n‐hexylcarbamyl or n‐octylcarbamyl moiety of inhibitors 12 and 13 is proposed to bind tightly to the peripheral anionic site of butyrylcholinesterase from molecular modeling. Butyrylcholinesterase prefers para‐carbamates to ortho‐ and meta‐carbamates, whereas acetylcholinesterase prefers para‐ and meta‐carbamates to ortho‐carbamates. This result implies that the anionic site of butyrylcholinesterase is relatively smaller than that of acetylcholinesterase because meta‐carbamates, which may bind to the anionic sites of both enzymes, are not potent inhibitors of butyrylcholinesterase. © 2009 Wiley Periodicals, Inc. J Biochem Mol Toxicol 23:303–308, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20286
Induction of apoptosis in rat lung epithelial cells by multiwalled carbon nanotubes
Authors: Ravichandran Prabakaran , Periyakaruppan Adaikkappan , Sadanandan Bindu , Ramesh Vani , Hall Joseph C. , Jejelowo Olufisayo , Ramesh Govindarajan T.
Published: October 2009

Carbon nanotubes (CNTs), the most promising material with unique characteristics, find its application in different fields ranging from composite materials to medicine and from electronics to energy storage. However, little is known about the mechanism behind the interaction of these particles with cells and their toxicity. So, here we investigated the adverse effects of multiwalled CNTs (MWCNTs) in rat lung epithelial (LE) cells. The results showed that the incubation of LE cells with 0.5–10 μg/mL of MWCNTs caused a dose‐ and time‐dependent increase in the formation of free radicals, the accumulation of peroxidative products, the loss of cell viability, and antioxidant depletion. The significant amount of incorporation of dUTPs in the nucleus after 24 h confirms the induction of apoptosis. It was also observed that there is an increase in the activity of both caspases‐3 and caspase‐8 in cells, with increases in time and the concentration of MWCNTs. No significant incorporation of dUTPs was observed in cells, incubated with z‐VAD‐fmk, which confirmed the role of caspases in DNA fragmentation. The present study reveals that MWCNTs induced oxidative stress and stimulated apoptosis signaling pathway through caspase activation in rat LE cell lines. © 2009 Wiley Periodicals, Inc. J Biochem Mol Toxicol 23:333–344, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20296
Effects of S‐adenosylhomocysteine and homocysteine on DNA damage and cell cytotoxicity in murine hepatic and microglia cell lines
Authors: Liu Chia‐Chyuan , Ho Wen‐Yueh , Leu Kuen‐Lin , Tsai Hsin‐Mao , Yang Tsai‐Hsiu
Published: October 2009

Limited research has been performed on S‐adenosylhomocysteine (SAH) or homocysteine (Hcy)‐evoked cell damage in hepatic and neuronal cells. In this study, we assessed effects of SAH or Hcy on cell cytotoxicity and DNA damage in hepatic and neuronal cells and attempted to find the underlying mechanism. Cell cytotoxicity and DNA damage were evaluated in murine hepatic cells (BNL CL.2 cell line) and microglia cells (BV‐2 cell line) with SAH or Hcy treatment for 48 h. The influences of SAH or Hcy on lipid peroxidation and DNA methylation were also measured in both cell lines. SAH (5–20 μM) or Hcy (1–5 mM) dose dependently inhibited cell cytotoxicity and enhanced DNA damage in both types of cells. Furthermore, SAH treatment markedly increased intracellular SAH levels and DNA hypomethylation, whereas Hcy caused minimal effects on these two parameters at much higher concentrations. Hcy significantly induced lipid peroxidation, but not SAH. The present results show that SAH might cause cellular DNA damage in hepatic and microglia cells by DNA hypomethylation, resulting in irreversible DNA damage and increased cell cytotoxicity. In addition, higher Hcy could induce cellular DNA damage through increased lipid peroxidation and DNA hypomethylation. We suggest that SAH is a better marker of cell damage than Hcy in hepatic and microglia cells. © 2009 Wiley Periodicals, Inc. J Biochem Mol Toxicol 23:349–356, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20298
The silly games we play
Authors: Rouse Robert W.
Published: October 2009

As we worry about cash and treasury problems in this economic crisis, it would be nice to have confidence in our senators and representatives. Are they the honest, knowledgeable, and wise leaders we need to steer our ship through stormy financial waters? The author had a unique insider's view of how Congress works. But what he saw was not reassuring. © 2009 Wiley Periodicals, Inc.
Zebrafish cnbp intron1 plays a fundamental role in controlling spatiotemporal gene expression during embryonic development
Authors: Weiner Andrea M.J. , Allende Miguel L. , Calcaterra Nora B.
Published: October 2009

Cellular nucleic acid binding protein (CNBP) is a strikingly conserved zinc‐finger nucleic acid chaperone required for forebrain development. Its depletion causes forebrain truncation mainly as a consequence of a reduction in size of craniofacial structures and neural crest derivatives. The CNBP expression pattern is complex and highly dynamic, but little is known of the underlying mechanisms regulating its spatiotemporal pattern. CNBP expression is highly conserved between all vertebrates characterized. In this study we have combined comparative sequence analysis and in vivo testing of DNA fragments in zebrafish to identify evolutionarily constrained regulatory motifs that likely control expression of the cnbp gene in embryos. We found a novel exon sequence located 5′ upstream of the Exon1‐sequence reported in most databases, and two transcription start sites that generate two primary‐transcripts that differ in their 5′UTRs and expression profile during zebrafish embryonic development. Furthermore, we found a region inside the intron1 sequence that controls the cnbp developmental‐specific transcriptional activation. Conserved binding sites for neural crest transcription factors were identified in this region. Mutagenesis analysis of the regulatory region revealed that Pax6/FoxD3 binding sites are required for proper zygotic cnbp expression. This is the first study that identifies, in vivo, cis‐regulatory sequences inside intron sequences and typical neural crest transcription factors involved in cnbp spatiotemporal specific transcriptional control during vertebrate embryonic development. J. Cell. Biochem. 108: 1364–1375, 2009. © 2009 Wiley‐Liss, Inc.
The interpersonal‐psychological theory of suicidal behavior: current status and future directions
Authors: Ribeiro Jessica D. , Joiner Thomas E.
Published: October 2009

The interpersonal‐psychological theory of suicidal behavior (Joiner, 2005) holds that an individual will die by suicide if he or she has both the desire for suicide and capability to act on that desire. According to the theory, suicidal desire results from the convergence of two interpersonal states: perceived burdensomeness and thwarted belongingness. However, desire alone is not sufficient to result in death by suicide—a third component must be present: the acquired capability for suicide, which develops from repeated exposure and habituation to painful and provocative events. The purpose of this article is to discuss four viable and timely directions for future research, given the current status of the theory. © 2009 Wiley Periodicals, Inc. J Clin Psychol 65:1–9, 2009.
Developmental origins of cognitive vulnerabilities to depression: review of processes contributing to stability and change across time
Authors: Hankin Benjamin L. , Oppenheimer Caroline , Jenness Jessica , Barrocas Andreas , Shapero Benjamin G. , Goldband Jessica
Published: October 2009

Cognitive theories of depression have been shown to be potent predictors of future increases in depressive symptoms and disorder in children, adolescents, and adults. This article focuses on potential developmental origins of the main cognitive vulnerabilities, including dysfunctional attitudes, negative cognitive style, and rumination. We selectively review processes and factors that have been hypothesized to contribute to the emergence and stabilization of these cognitive risk factors. This review focuses on genetic factors, temperament, parents and peers as salient interpersonal influences, and stressful life events. We end with suggestions for future theory development and research. In particular, we emphasize the need for additional conceptual and empirical work integrating these disparate processes together into a coherent, developmental psychopathological model, and we highlight the coexistence of both stability and change in the development of cognitive vulnerabilities to depression across the lifespan. © 2009 Wiley Periodicals, Inc. J Clin Psychol 65:1–12, 2009.
Sonographic detection of an aneurysm of the gastroepiploic artery
Authors: Kato Ryusuke , Ishida Hideaki , Komatsuda Tomoya , Yagisawa Hitoshi , Ishii Tooru
Published: October 2009

Gastroepiploic artery aneurysm (GEAA) is very rare.1 Furthermore, most GEAA cases are diagnosed after their rupture. We report a case of asymptomatic GEAA. The patient was a 61‐year‐old man. Sonography (US) revealed a 2‐cm anechoic mass in the epigastrium near the anterior abdominal wall. Color Doppler US and contrast‐enhanced US showed arterial flow within the mass leading to the diagnosisof visceral artery aneurysm. CT and angiography confirmed the diagnosis of right GEAA, and the aneurysm was treated successfully with embolization. Follow‐up US 6 months later confirmed the absence of blood flow within the lesion. © 2009 Wiley Periodicals, Inc. J Clin Ultrasound, 2010
Evidence‐based approach for prevention of radiocontrast‐induced nephropathy
Authors: Abu Jawdeh Bassam G. , Kanso Abbas A. , Schelling Jeffrey R.
Published: October 2009

The frequency of radiocontrast administration is dramatically increasing, with over 80 million doses delivered annually worldwide. Although recently developed radiocontrast agents are relatively safe in most patients, contrast nephropathy (CN) is still a major source of in‐hospital and long‐term morbidity and mortality, particularly in patients with preexisting kidney disease. Multiple protocols for CN prevention have been studied; however, strict guidelines have not been established, in part because of conflicting efficacy data for most prevention approaches. In this work, we critically review the major trials that have addressed common CN prophylaxis strategies, including type of radiocontrast media, N‐acetylcysteine administration, extracellular fluid volume expansion, and hemofiltration/hemodialysis. We conclude with evidence‐based recommendations for CN prevention, which emphasize concurrent NaHCO3 infusion and N‐acetylcysteine administration. These guidelines should be helpful to hospitalists, who frequently order radiocontrast studies, and could therefore have a significant impact on prevention of CN. Journal of Hospital Medicine 2009;4:500–506. © 2009 Society of Hospital Medicine.
Medical humanities as tools for the teaching of patient‐centered care
Authors: Nazario Rubén J.
Published: October 2009

The Institute of Medicine, in its 2001 report Crossing the Quality Chasm: A New Health System for the 21st Century, highlighted patient‐centered care as an area for the development of quality measures. Since then, medical centers across the country have incorporated patient‐centered modalities in their healthcare delivery systems. In academic medical centers, interest in patient‐centered care has raised the awareness of the interactions between the humanities and medicine. This work aims to define the roles of patient‐centered medicine and the medical humanities in the academic medical environment, to establish the shared values between the medical humanities and patient‐centered care, and to demonstrate how the medical humanities can be a tool for the teaching of patient‐centered care. Journal of Hospital Medicine 2009;4:512–514. © 2009 Society of Hospital Medicine.
Delays in discharge in a tertiary care pediatric hospital
Authors: Srivastava Rajendu , Stone Bryan L. , Patel Raza , Swenson Matthew , Davies Andrew , Maloney Christopher G. , Young Paul C. , James Brent C.
Published: October 2009

BACKGROUND:

Delays in discharges affect both efficiency and timeliness of care; 2 measures of quality of inpatient care.

OBJECTIVE:

Describe number, length, and type of delays in hospital discharges. Characterize impact of delays on overall length of stay (LOS) and costs.

DESIGN:

Prospective observational cohort study.

SETTING:

Tertiary‐care children's hospital.

PATIENTS:

All children on 2 medical teams during August 2004.

INTERVENTION:

Two research assistants presented detailed data of patient care (from daily rounds) to 2 physicians who identified delays and classified the delay type. Discharge was identified as delayed if there was no medical reason for the patient to be in the hospital on a given day.

MEASUREMENTS:

Delays were classified using a validated and reliable instrument, the Delay Tool. LOS and costs were extracted from an administrative database.

RESULTS:

Two teams cared for 171 patients. Mean LOS and costs were 7.3 days (standard deviation [SD] 14.3) and $15,197 (SD 38,395), respectively: 22.8% of patients experienced at least 1 delay, accounting for 82 delay‐related hospital days (9% of total hospital days) and $170,000 in costs (8.9% of hospital costs); 42.3% of the delays resulted from physician behavior, 21.8% were related to discharge planning, 14.1% were related to consultation, and 12.8% were related to test scheduling.

CONCLUSIONS:

Almost one‐fourth of patients in this 1‐month period could have been discharged sooner than they were. Impact of delays on LOS and costs are substantial. Interventions will need to address variations in physician criteria for discharge, more efficient discharge planning, and timely scheduling of consultation and diagnostic testing. Journal of Hospital Medicine 2009;4:481–485. © 2009 Society of Hospital Medicine.
The role of physician engagement on the impact of the hospital‐based practice improvement module (PIM)
Authors: Caverzagie Kelly J. , Bernabeo Elizabeth C. , Reddy Siddharta G. , Holmboe Eric S.
Published: October 2009

BACKGROUND:

Physicians play an important role in hospital quality improvement (QI) activities. The Hospital‐Based Practice Improvement Module (Hospital PIM) is a web‐based assessment tool designed by the American Board of Internal Medicine (ABIM) to facilitate physician involvement in QI as a part of maintaining certification.

OBJECTIVE:

The primary objective of this study is to explore the impact of the Hospital PIM on physicians participating in hospital‐based QI.

DESIGN:

Qualitative design consisting of semistructured telephone interviews.

PARTICIPANTS:

A purposeful sample of 21 early‐completers of the Hospital PIM.

MEASUREMENTS:

Grounded‐theory analysis was used to analyze transcripts of the semistructured telephone interviews.

RESULTS:

Physician completers of the Hospital PIM describe the impact in a variety of ways, including new learning about QI principles and activities, added value to their practice, and enhanced QI experience. An emerging theme was the mediating role of physician engagement in relation to the overall impact of the Hospital PIM. Four case studies illustrate these findings. Facilitators and barriers that influence the overall experience of the PIM are described.

CONCLUSIONS:

The impact of completing the Hospital PIM is mediated by the degree of physician engagement with the QI process. Physicians who become engaged with the Hospital PIM and QI process may be more likely to report successful experiences in implementing QI activities in hospital settings than those who do not become engaged. Journal of Hospital Medicine 2009;4:466–470. © 2009 Society of Hospital Medicine.
Meeting your needs, now and in the future
Authors: Saliba Georgene
Published: October 2009

President Obama has repeatedly said that healthcare reform is not a luxury that can be postponed but a necessity that cannot wait. Healthcare change is all around us, and ASHRM is continually working to assist its members with opportunities to demonstrate their value and leadership within their respective organizations.
The intramandibular joint in Girella: A mechanism for increased force production?
Authors: Ferry‐Graham Lara A. , Konow Nicolai
Published: October 2009

Intramandibular joints (IMJ) are novel articulations between bony elements of the lower jaw that have evolved independently in multiple fish lineages and are typically associated with biting herbivory. This novel joint is hypothesized to function by augmenting oral jaw expansion during mouth opening, which would increase contact between the tooth‐bearing area of the jaws and algal substratum during feeding, resulting in more effective food removal from the substrate. Currently, it is not understood if increased flexibility in a double‐jointed mandible also results in increased force generation during herbivorous biting and/or scraping. Therefore, we selected the herbivore Girella laevifrons for a mechanical study of the IMJ lower jaw lever system. For comparative purposes, we selected Graus nigra, a non–IMJ‐bearing species, from a putative sister genus. Shortening of the lower jaw, during flexion at the IMJ, resulted in a more strongly force‐amplifying closing lever system in the lower jaw, even in the absence of notable changes to the sizes of the muscles that power the lever system. To explain how the IMJ itself functions, we use a four‐bar linkage that models the transmission of force and velocity to and through the lower jaw via the IMJ. When combined, the functionally interrelated lever and linkage models predict velocity to be amplified during jaw opening, whereas jaw closing is highly force modified by the presence of the IMJ. Moreover, the function of the IMJ late during jaw closure provides enough velocity to detach sturdy and resilient prey. Thus, this novel jaw system can alternate between amplifying the force or the velocity exerted onto the substrate where food items are attached. This unique mechanical configuration supports the argument that IMJs are functional innovations that have evolved to meet novel mechanical challenges and constraints placed on the feeding apparatus by attached and sturdy food sources. J. Morphol. 2010. © 2009 Wiley‐Liss, Inc.
Ultrastructure of spermiogenesis in the Cottonmouth, Agkistrodon piscivorus (Squamata: Viperidae: Crotalinae)
Authors: Gribbins Kevin M. , Rheubert Justin L. , Anzalone Marla L. , Siegel Dustin S. , Sever David M.
Published: October 2009

To date multiple studies exist that examine the morphology of spermatozoa. However, there are limited numbers of data detailing the ontogenic characters of spermiogenesis within squamates. Testicular tissues were collected from Cottonmouths (Agkistrodon piscivorus) and tissues from spermiogenically active months were analyzed ultrastructurally to detail the cellular changes that occur during spermiogenesis. The major events of spermiogenesis (acrosome formation, nuclear elongation/DNA condensation, and flagellar development) resemble that of other squamates; however, specific ultrastructural differences can be observed between Cottonmouths and other squamates studied to date. During acrosome formation vesicles from the Golgi apparatus fuse at the apical surface of the nuclear membrane prior to making nuclear contact. At this stage, the acrosome granule can be observed in a centralized location within the vesicle. As elongation commences the acrosome complex becomes highly compartmentalized and migrates laterally along the nucleus. Parallel and circum‐cylindrical microtubules (components of the manchette) are observed with parallel microtubules outnumbering the circum‐cylindrical microtubules. Flagella, displaying the conserved 9 + 2 microtubule arrangement, sit in nuclear fossae that have electron lucent shoulders juxtaposed on either side of the spermatids basal plates. This study aims to provide developmental characters for squamates in the subfamily Crotalinae, family Viperidae, which may be useful for histopathological studies on spermatogenesis in semi‐aquatic species exposed to pesticides. Furthermore, these data in the near future may provide morphological characters for spermiogenesis that can be added to morphological data matrices that may be used in phylogenetic analyses. J. Morphol. 2010. © 2009 Wiley‐Liss, Inc.
α‐Synuclein abnormalities in mouse models of peroxisome biogenesis disorders
Authors: Yakunin Eugenia , Moser Ann , Loeb Virginie , Saada Ann , Faust Phyllis , Crane Denis I. , Baes Myriam , Sharon Ronit
Published: October 2009

α‐Synuclein (αS) is a presynaptic protein implicated in Parkinson's disease (PD). Growing evidence implicates mitochondrial dysfunction, oxidative stress, and αS–lipid interactions in the gradual accumulation of αS in pathogenic forms and its deposition in Lewy bodies, the pathological hallmark of PD and related synucleinopathies. The peroxisomal biogenesis disorders (PBD), with Zellweger syndrome serving as the prototype of this group, are characterized by malformed and functionally impaired peroxisomes. Here we utilized the PBD mouse models Pex2–/–, Pex5–/–, and Pex13–/– to study the potential effects of peroxisomal dysfunction on αS‐related pathogenesis. We found increased αS oligomerization and phosphorylation and its increased deposition in cytoplasmic inclusions in these PBD mouse models. Furthermore, we show that αS abnormalities correlate with the altered lipid metabolism and, specifically, with accumulation of long chain, n‐6 polyunsaturated fatty acids that occurs in the PBD models. © 2009 Wiley‐Liss, Inc.
A yield criterion for isotropic and cross‐anisotropic cohesive‐frictional materials
Authors: Mortara G.
Published: October 2009

This paper proposes a yield and failure criterion for cohesive and frictional materials. The function is given by the combination of a Lode dependence for the behaviour in the deviatoric plane and a meridian function for the pressure‐dependent behaviour. A variety of shapes can be achieved with the proposed criterion including Lode dependences which are able to reproduce the behaviour of isotropic and cross‐anisotropic materials in the deviatoric plane. The criterion is validated through the comparison with experimental data based on multiaxial experimental tests on clays, sands, rocks and concrete. Finally, the convexity of the criterion is analysed and discussed. Copyright © 2009 John Wiley & Sons, Ltd.
Discrete element modeling of direct shear tests for a granular material
Authors: Yan Ying , Ji Shunying
Published: October 2009

A succinct 3D discrete element model, with clumps to resemble the real shapes of granular materials, is developed. The quaternion method is introduced to transform the motion and force of a clump between local and global coordinates. The Hertz–Mindlin elastic contact force model, incorporated with the nonlinear normal viscous force and the Mohr–Coulomb friction law, is used to describe the interactions between particles. The proposed discrete element model is used to simulate direct shear tests of the irregular limestone rubbles. The simulation results of vertical displacements and shear stresses with a mixture of clumps are compared well with that of laboratory tests. The bulk friction coefficients are calculated and discussed under different contact friction coefficients and normal stresses. Copyright © 2009 John Wiley & Sons, Ltd.
Dominance and gene dosage balance in health and disease: why levels matter!
Authors: Veitia Reiner A. , Birchler James A.
Published: October 2009

The classical concept of genetic dominance is a simplification of a more quantitative reality. This is clearly exemplified by aneuploid syndromes, of which the best known case is trisomy 21. Moreover, there is an increasing number of clinical conditions due to reduced dosage (haploinsufficiency) of genes encoding transcription factors and other proteins involved in signal transduction and macromolecular complexes. In such genetic diseases, a high degree of phenotypic variability is observed, which calls for an explanation. The sources of dominance are heterogeneous and difficult to cover in a brief review. Here, we will focus on the molecular bases of dosage‐sensitive syndromes from the perspective of the gene dosage balance hypothesis, which postulates that stoichiometric alterations of macromolecular complexes or cellular networks are responsible for dominant phenotypes, because of the existing non‐linear relationships between the genotypic and phenotypic values with which they are associated. Copyright © 2009 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Pulmonary hypertension in children and young adults with sickle cell disease: Evidence for familial clustering
Authors: Dahoui Hanane A. , Hayek Munya N. , Nietert Paul J. , Arabi Mariam T. , Muwakkit Samar A. , Saab Raya H. , Bissar Abdallah N. , Jumaa Nidal M. , Farhat Fadi S. , Dabbous Ibrahim A. , Bitar Fadi F. , Abboud Miguel R.
Published: October 2009

Background

Pulmonary hypertension (PHTN) is increasingly recognized as a serious complication of sickle cell disease (SCD). Our objective was to determine the prevalence of PHTN and identify factors associated with PHTN among children and young adults with SCD in Lebanon.

Procedure

From June 2004 to June 2008, 90 patients were studied. Correlation of TRV with LDH, mean corpuscular volume (MCV), fetal hemoglobin (HbF), hydroxyurea use, and G6PD deficiency was performed. Transthoracic Doppler echocardiography was performed during steady‐state at each patient's initial visit and yearly thereafter. PHT was defined as a tricuspid regurgitant jet velocity (TRV) ≥2.5 m/sec.

Results

Twenty‐seven patients (31.8%) were found to have PHTN. They had significantly higher LDH levels (P = 0.008) and MCV (P = 0.024). There was a higher percentage of patients on hydroxyurea in the group with PHTN (78% vs. 50%, P = 0.015). Furthermore, five children, mean age 9.8 years (range, 6–13 years), with initially normal TRV developed PHTN while on hydroxyurea for at least 3 years, at a mean dose of 19.2 mg/kg/day (range, 14–24). PHTN clustered in families and was found in all members with SCD in 7 of the 21 families studied; they contributed 16 of the 27 patients with PHTN. None of the 21 patients with PHTN were G6PD deficient compared to 4 of 36 without PHTN.

Conclusions

PHTN was common, associated with increased hemolysis but not G6PD deficiency, and clustered in families. Moreover, PHTN developed despite hydroxyurea therapy in five patients. Pediatr Blood Cancer 2010;54:398–402. © 2009 Wiley‐Liss, Inc.
Differences between peer victimization in cyber and physical settings and associated psychosocial adjustment in early adolescence
Authors: Dempsey Allison G. , Sulkowski Michael L. , Nichols Rebecca , Storch Eric A.
Published: October 2009

The increasing use of cyberspace as a social networking forum creates a new medium for youth to become victims of peer aggression. This study used factor analysis techniques to confirm whether survey questions about frequency of cyber victimization formed a distinct latent construct from questions about relational and overt victimization information in a large (N = 1,665) sample of middle school students. A secondary goal was to relate experiences of cyber victimization to symptoms of depression and social anxiety. Results indicate that cyber victimization is separate latent factor from overt and relational victimization. Experiences of cyber victimization were weakly associated with symptoms of social anxiety, but not depression. These results signify that cyber victimization deserves future empirical and clinical attention. © 2009 Wiley Periodicals, Inc.
Working conditions as risk or resiliency factors for teachers of students with emotional and behavioral disabilities
Authors: Albrecht Susan Fread , Johns Beverley H. , Mounsteven Joyce , Olorunda Olufunmilola
Published: October 2009

This pilot study examined working conditions reported by special education teachers of students with emotional and behavioral disorders (EBD) to identify factors common to teachers likely to leave their positions within the next 2 years and factors common to those likely to stay. Survey responses from an international sample of 776 teachers and related services providers indicated administrative support, availability of support personnel, access to curricula, adequate time for paperwork, years of teaching students with EBD, and behavior management approach used are significantly related to participants' intent to stay or leave. Physical injury by a student was among factors reported as not significant. This study is discussed in terms of its implications for addressing the current shortage of EBD teachers. © 2009 Wiley Periodicals, Inc.
Reliability and validity evidence of scores on the Achievement Goal Tendencies Questionnaire in a sample of Spanish students of compulsory secondary education
Authors: Ingles Candido J. , Garcia‐Fernandez Jose M. , Castejon Juan L. , Valle Antonio , Delgado Beatriz , Marzo Juan C.
Published: October 2009

This study examined the reliability and validity evidence drawn from the scores of the Spanish version of the Achievement Goal Tendencies Questionnaire (AGTQ) using a sample of 2,022 (51.1% boys) Spanish students from grades 7 to 10. Confirmatory factor analysis replicated the correlated three‐factor structure of the AGTQ in this sample: Learning Goals (LG), Social Reinforcement Goals (SRG), and Performance Goals (PG). The AGTQ yields relatively reliable scores for Spanish students. Logistic regression analyses were used to provide additional validity evidence of AGTQ scores on academic success (general, Spanish, and mathematics). Results indicated that general academic success was 15% and 5% more likely every time that scores on LG and PG scales increased 1 point, respectively, although general academic success was 9% less likely every time that scores on SRG scale increased 1 point. These results were similar for Spanish and mathematics. However, the score on the LG scale did not forecast success in both subjects. © 2009 Wiley Periodicals, Inc.
Information Systems Project Management in PMJ: A Brief History
Authors: Rivard Suzanne , Dupré Ruth
Published: October 2009

The Project Management Institute (PMI) plays an important role in the training, career development, and recognition of information systems (IS) project managers. Indeed, not only do IS professionals account for a large proportion of the PMI constituency, but PMI is also influential in the training of IS project managers. This study explores further the contribution of PMI to IS project management by means of its main publication outlet, the Project Management Journal (PMJ). To do so, the contents of the 39 IS project management articles published in PMJ during 1988-2005 were analyzed. The article focuses on the following dimensions: the relative importance of IS project management articles published by PMJ; the profile of the authors of IS project management articles in PMJ; the main issues, in terms of IS project management, covered by PMJ; and the major gaps, in terms of IS project management, in the coverage of this domain by PMJ.
The Role of Crystallinity on Polymer Interaction with Oxygen Plasma
Authors: Junkar Ita , Cvelbar Uroš , Vesel Alenka , Hauptman Nina , Mozetič Miran
Published: October 2009

In order to study the role of polymer crystallinity, we performed oxygen plasma treatment experiments on amorphous and semicrystalline poly(ethylene terephthalate) (PET) polymers. The samples were treated in weakly ionized, highly dissociated RF oxygen plasma in glow region for different exposure times. We found that the degree of polymer crystallinity has an influence on the recombination probability of neutral atoms which interact with the surface. For amorphous polymers the recombination coefficient is in the range from 8.3 × 10−4 to 2.1 × 10−4 and for semicrystalline from 4 × 10−4 to 2.5 × 10−5. The degree of crystallinity in plasma processing also has influences on surface topography, formation of new functional groups, etching and hydrophobic recovery (ageing). Therefore, the polymer crystallinity should be taken into consideration when optimizing plasma treatment processes for industry as well as for accounting neutral atom recombination on polymer surfaces.

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Early elevations in B‐type natriuretic peptide levels are associated with poor clinical outcomes in pediatric acute lung injury
Authors: Reel Bhupinder , Oishi Peter E. , Hsu Jong‐Hau , Gildengorin Ginny , Matthay Michael A. , Fineman Jeffrey R. , Flori Heidi
Published: October 2009

Objectives

To determine B‐type natriuretic peptide (BNP) levels in infants and children with acute lung injury (ALI), and to investigate associations between BNP levels and clinical outcome.

Design

Prospective observational study.

Subjects

After informed consent, plasma was collected from 48 pediatric patients on day 1 of ALI.

Methodology

Plasma BNP levels were measured by immunoassay on day 1 of ALI in 48 pediatric patients. Associations between BNP levels and outcome were determined.

Results

The mean PaO2/FiO2 at the onset of ALI was 155 (±74) and BNP values ranged from 5 to 2,060 pg/ml with a mean of 109 (±311). BNP levels were inversely correlated with ventilator‐free days (Spearman rho −0.30, P = 0.04), and positively correlated with exhaled tidal volume (Spearman rho 0.44, P = 0.02). BNP levels were higher in patients receiving inotropic support (n = 12) than patients not receiving inotropic support (n = 33, P = 0.02). BNP levels were correlated with PRISM III scores (Spearman rho 0.55, P < 0.001) and PELOD scores (Spearman rho 0.4, P = 0.006). Mortality for the cohort was 15%. BNP levels were higher in non‐survivors (n = 7) than survivors (n = 41, P = 0.055).

Conclusions

BNP levels are elevated in children with ALI/ARDS early in the disease course, and increased levels are associated with worse clinical outcome. Pediatr Pulmonol. 2009; 44:1118–1124. ©2009 Wiley‐Liss, Inc.
Proteomic profiling of cancer of the gingivo‐buccal complex: Identification of new differentially expressed markers
Authors: Govekar Rukmini B. , D'Cruz Anil K. , Alok Pathak K. , Agarwal Jaiprakash , Dinshaw Ketayun A. , Chinoy Roshan F. , Gadewal Nikhil , Kannan Sadhana , Sirdeshmukh Ravi , Sundaram Curam S. , Malgundkar Siddhi A. , Kane Shubhada V. , Zingde Surekha M.
Published: October 2009

Tobacco‐related oral cancer is the most common cancer among Indian males, gingivo‐buccal complex (GBC) being the most affected subsite due to the habit of chewing tobacco. Proteins from the lysates of microdissected normal and transformed epithelium from clinically well‐characterized tissue samples of the GBC were separated by two‐dimensional gel electrophoresis to identify differentially expressed proteins. Eleven protein spots showed differential expression, which could withstand the stringency of statistical evaluation. The observations were confirmed with additional tissues. Nine of these differentiators were identified by MS as lactate dehydrogenase B, α‐enolase, prohibitin, cathepsin D, apolipoprotein A‐I, tumor protein translationally controlled‐1, an SFN family protein, 14‐3‐3σ and tropomyosin. Cluster analysis indicated that these proteins, as a coexpressed set, could distinguish normal and transformed epithelium. Functionally, these differentiator molecules are relevant to the pathways and processes that have been previously implicated in oral carcinogenesis and could therefore be investigated further as a panel of markers for management of cancer of the GBC.
Proteomic profiling reveals comprehensive insights into adrenergic receptor‐mediated hypertrophy in neonatal rat cardiomyocytes
Authors: Li Zijian , Liu Ning , Zhang Li‐Shu , Gong Kaizheng , Cai Yuanbin , Gao Wei , Liu Zhiqiang , Liu Shuying , Han Qide , Zhang Youyi
Published: October 2009

Myocardial adrenergic receptors (ARs) play important roles in cardiac hypertrophy. However, the detailed molecular mechanism of AR‐mediated cardiac hypertrophy remains elusive to date. To gain full insight into how ARs are involved in the regulation of cardiac hypertrophy, protein expression profiling was performed with comparative proteomics approach on neonatal rat cardiomyocytes. Forty‐six proteins were identified as differentially expressed in hypertrophic cardiomyocytes induced by AR stimulation. To better understand the biological significance of the obtained proteomic data, we utilized the ingenuity pathway analysis tool to construct biological networks and analyze function and pathways that might associate with AR‐mediated cardiac hypertrophy. Pathway analysis strongly suggested that ROS may be involved in the development of AR‐mediated cardiac hypertrophy, which was then confirmed by further experimentation. The results showed that a marked increase in ROS production was detected in AR‐mediated cardiac hypertrophy and blocking of ROS production significantly inhibited AR‐mediated cardiac hypertrophy. We further proved that the ROS production was through NADPH oxidase or the mitochondrial electron transport chain and this ROS accumulation resulted in activation of extracellular signal‐regulated kinase 1/2 leading to AR‐mediated cardiac hypertrophy. These experimental results support the hypothesis, from the ingenuity pathway analysis, that AR‐mediated cardiac hypertrophy is associated with the dysregulation of a complicated oxidative stress‐regulatory network. In conclusion, our results provide a basis for understanding the detailed molecular mechanisms of AR‐mediated cardiac hypertrophy.