bluuebunny/crossref_metadata_2025 huggingface dataset:
Transcriptional upregulation of DDR2 by ATF4 facilitates osteoblastic differentiation through p38 MAPK-mediated Runx2 activation
Authors: Lin Kuan-Liang , Chou Ching-Heng , Hsieh Shu-Chen , Hwa Su-Yang , Lee Ming-Ta , Wang Fung-Fang
Published: June 2010

Deficiency of the collagen receptor discoidin domain receptor tyrosine kinase (DDR2) in mice and humans results in dwarfism and short limbs, of which the mechanism remains unknown. Here we report that DDR2 is a key regulator of osteoblast differentiation. DDR2 mRNA expression was increased at an early stage of induced osteoblast differentiation. In the subchondral bone of human osteoarthritic knee, DDR2 was detected in osteoblastic cells. In mouse embryos, DDR2 expression was found from E11 to E15, preceding osteocalcin (OCN) and coinciding with Runx2 expression. Activating transcription factor 4 (ATF4) enhanced DDR2 mRNA expression, and knockdown of ATF4 expression delayed DDR2 induction during osteoblast differentiation. A CCAAT/enhancer binding protein (C/EBP) binding site at −1150 bp in the DDR2 promoter was required for ATF4-mediated DDR2 activation. C/EBPβ bound to and cooperated with ATF4 in stimulating DDR2 transcription; accordingly, the ATF4 mutants deficient of C/EBPβ binding were incapable of transactivating DDR2. Overexpression of DDR2 increased osteoblast-specific gene expression. Conversely, knockdown of DDR2 suppressed osteogenic marker gene expression and matrix mineralization during the induced osteogenesis. The stimulation of p38 MAPK by DDR2 was required for DDR2-induced activation of Runx2 and OCN promoters. Together our findings uncover a pathway in which ATF4, by binding to C/EBPβ transcriptionally upregulates DDR2 expression, and DDR2, in turn, activates Runx2 through p38 MAPK to promote osteoblast differentiation. © 2010 American Society for Bone and Mineral Research.
Role of trabecular microarchitecture and its heterogeneity parameters in the mechanical behavior of ex vivo human L3 vertebrae
Authors: Wegrzyn Julien , Roux Jean-Paul , Arlot Monique E , Boutroy Stéphanie , Vilayphiou Nicolas , Guyen Olivier , Delmas Pierre D , Chapurlat Roland , Bouxsein Mary L
Published: June 2010

Low bone mineral density (BMD) is a strong risk factor for vertebral fracture risk in osteoporosis. However, many fractures occur in people with moderately decreased or normal BMD. Our aim was to assess the contributions of trabecular microarchitecture and its heterogeneity to the mechanical behavior of human lumbar vertebrae. Twenty-one human L3 vertebrae were analyzed for BMD by dual-energy X-ray absorptiometry (DXA) and microarchitecture by high-resolution peripheral quantitative computed tomography (HR-pQCT) and then tested in axial compression. Microarchitecture heterogeneity was assessed using two vertically oriented virtual biopsies—one anterior (Ant) and one posterior (Post)—each divided into three zones (superior, middle, and inferior) and using the whole vertebral trabecular volume for the intraindividual distribution of trabecular separation (Tb.Sp*SD). Heterogeneity parameters were defined as (1) ratios of anterior to posterior microarchitectural parameters and (2) the coefficient of variation of microarchitectural parameters from the superior, middle, and inferior zones. BMD alone explained up to 44% of the variability in vertebral mechanical behavior, bone volume fraction (BV/TV) up to 53%, and trabecular architecture up to 66%. Importantly, bone mass (BMD or BV/TV) in combination with microarchitecture and its heterogeneity improved the prediction of vertebral mechanical behavior, together explaining up to 86% of the variability in vertebral failure load. In conclusion, our data indicate that regional variation of microarchitecture assessment expressed by heterogeneity parameters may enhance prediction of vertebral fracture risk. © 2010 American Society for Bone and Mineral Research.
Effect of chronic intermittent hypoxia on biological behavior and hypoxia‐associated gene expression in lung cancer cells
Authors: Liu Yonglei , Song Xianrang , Wang Xingwu , Wei Ling , Liu Xiuju , Yuan Shuanghu , Lv Liyan
Published: June 2010

Hypoxia plays an important role in the development of solid tumors and is associated with their therapeutic resistance. There exist three major forms of hypoxia: acute, chronic, and intermittent hypoxia. Previous studies have shown that cancer cells could behave in the form of adaptation to hypoxia in tumor growth, which could result in their biological changes and determine their responses to the therapies. To investigate the tumor cells' adaptation to hypoxia, we recreated two models using two lung cancer cell lines in the presence of intermittent hypoxia, which is characterized by changes in oxygen pressure within the disorganized vascular network. We investigated biological behaviors such as cell cycle, proliferation, radiation sensitivity, apoptosis and migration, hypoxia signal pathway in the lung cancer cells treated with chronic intermittent hypoxia, as well as the role of hypoxia inducible factor 1 there, hypoxia‐inducible genes analyzed by real‐time RT‐PCR chip in H446 cells treated with the model. The results indicated the changes of some hypoxia target gene expressions of those induced by hypoxia, some of which were confirmed by real‐time RT‐PCR. The cells mediated by irradiation induced resistance to radiation and apoptosis and increased metastasis in lung cancer cells. It was found that such changes were related to hypoxia inducible factor 1, alpha subunit (HIF‐1α). J. Cell. Biochem. 111: 554–563, 2010. © 2010 Wiley‐Liss, Inc.
Transcription activation of myostatin by trichostatin A in differentiated C2C12 myocytes via ASK1‐MKK3/4/6‐JNK and p38 mitogen‐activated protein kinase pathways
Authors: Han Der‐Sheng , Huang Hsiang‐Po , Wang Tyng‐Guey , Hung Meng‐Yu , Ke Jia‐Yu , Chang Kuei‐Ting , Chang Hsin‐Yu , Ho Yu‐Ping , Hsieh Wei‐Yuan , Yang Wei‐Shiung
Published: June 2010

Myostatin is a negative regulator of skeletal muscle mass. The pathways employed in modulating myostatin gene expression are scarcely known. We aimed to determine the signaling pathway of myostatin induction by a histone deacetylase (HDAC) inhibitor–trichostatin A (TSA) in differentiated C2C12 myocytes. TSA increased myostatin mRNA expression up to 40‐fold after treatment for 24 h, and induced myostatin promoter activity up to 3.8‐fold. Pretreatment with actinomycin D reduced the TSA‐induced myostatin mRNA by 93%, suggesting TSA‐induced myostatin expression mainly at the transcriptional level. Pretreatment with p38 MAPK (SB203580) and JNK (SP600125) inhibitors, but not ERK (PD98059) inhibitor, blocked TSA‐induced myostatin expression, respectively, by 72% and 43%. Knockdown of p38 MAPK by RNAi inhibited the TSA‐induced myostatin expression by 77% in C2C12 myoblasts. The protein levels of phosphorylated p38 MAPK, JNK, but not ERK, increased with TSA treatment in differentiated C2C12 cells. Direct activation of p38 MAPK and JNK by anisomycin in the absence of TSA increased myostatin mRNA by fourfold. The phosphorylated form of the kinase MKK3/4/6 and ASK1, upstream cascades of p38 MAPK and JNK, also increased with TSA treatment. We concluded that the induction of myostatin by TSA treatment in differentiated C2C12 cells is in part through ASK1‐MKK3/6‐p38 MAPK and ASK1‐MKK4‐JNK signaling pathways. Activation of p38 MAPK and JNK axis is necessary, but not sufficient for TSA‐induced myostatin expression. J. Cell. Biochem. 111: 564–573, 2010. © 2010 Wiley‐Liss, Inc.
Cigarette smoke extract induces HO‐1 expression in mouse cerebral vascular endothelial cells: Involvement of c‐Src/NADPH oxidase/PDGFR/JAK2/STAT3 pathway
Authors: Shih Ruey‐Horng , Lee I‐Ta , Hsieh Hsi‐Lung , Kou Yu Ru , Yang Chuen‐Mao
Published: June 2010

Several chemicals present in cigarette smoke (CS) have been reported to induce heme oxygenase‐1 (HO‐1) expression, which represents a prime defense mechanism in protecting the cells from stress‐dependent adverse effects on peripheral vascular system. However, the effects of cigarette smoke extract (CSE) on HO‐1 induction and the mechanisms underlying CSE‐induced HO‐1 expression in brain vessels are not completely understood. Here, we used a mouse brain endothelial cell culture (bEnd.3) to investigate the effect of CSE on HO‐1 induction and the mechanisms underlying CSE‐induced HO‐1 expression in cerebral vessels. We demonstrated that sublethal concentrations of CSE (30 µg/ml) induced submaximal HO‐1 expression in bEnd.3 cells. NADPH oxidase‐dependent ROS generation played a key role in CSE‐induced HO‐1 expression. CSE‐induced HO‐1 expression was mediated through PDGFR/JAK2/STAT3 cascade, which was observed by pretreatment with the respective pharmacological inhibitors or transfection with PDGFR shRNA. CSE activated NADPH oxidase through c‐Src in bEnd.3 cells. Taken together, these results suggested that, in bEnd.3 cells, CSE‐induced HO‐1 expression was mediated through PDGFR/JAK2/STAT3 cascade, which was regulated by c‐Src or c‐Src activated‐NADPH oxidase/ROS. J. Cell. Physiol. 225: 741–750, 2010. © 2010 Wiley‐Liss, Inc.
Origin of cardiac progenitor cells in the developing and postnatal heart
Authors: Kuhn Elizabeth N. , Wu Sean M.
Published: June 2010

The mammalian heart lacks the capacity to replace the large numbers of cardiomyocytes lost due to cardiac injury. Several different cell‐based routes to myocardial regeneration have been explored, including transplantation of cardiac progenitors and cardiomyocytes into injured myocardium. As seen with cell‐based therapies in other solid organ systems, inherent limitations, such as host immune response, cell death and long‐term graft instability have hampered meaningful cardiac regeneration. An understanding of the cell biology of cardiac progenitors, including their developmental origin, lineage markers, renewal pathways, differentiation triggers, microenvironmental niche, and mechanisms of homing and migration to the site of injury, will enable further refinement of therapeutic strategies to enhance clinically meaningful cardiac repair. J. Cell. Physiol. 225: 321–325, 2010. © 2010 Wiley‐Liss, Inc.
GPCR kinase 2 interacting protein 1 (GIT1) regulates osteoclast function and bone mass
Authors: Menon Prashanthi , Yin Guoyong , Smolock Elaine M. , Zuscik Michael J. , Yan Chen , Berk Bradford C.
Published: June 2010

G‐protein‐coupled receptor (GPCR) kinase 2 interacting protein‐1 (GIT1) is a scaffold protein expressed in various cell types including neurons, endothelial, and vascular smooth muscle cells. The GIT1 knockout (KO) mouse has a pulmonary phenotype due to impaired endothelial function. Because GIT1 is tyrosine phosphorylated by Src kinase, we anticipated that GIT1 KO should have a bone phenotype similar to Src KO. Microcomputed tomography of the long bones revealed that GIT1 KO mice have a 2.3‐fold increase in bone mass compared to wild‐type controls. Histomorphometry showed increased trabecular number and connectivity suggesting impaired bone remodeling. Immunoblot analysis of GIT1 expression showed that it was expressed in both osteoclasts and osteoblasts. Osteoblast activity and function assayed by alkaline phosphatase, mineral nodule formation, and in vivo calcein labeling were normal in GIT1 KO mice suggesting that the observed increase in bone mass was due to an osteoclast defect. GIT1 KO bone marrow cells differentiated into multinucleated osteoclasts, but had defective bone resorbing function on dentin slices. This defect was likely caused by loss of podosome belt based on immunofluorescence analysis and previous studies showing that GIT1 is required for podosome formation. Furthermore, we found that GIT1 was a regulator of receptor activator of NFκB (RANK) signaling since it was tyrosine phosphorylated in a Src‐dependent manner and was required for phospholipase C‐γ2 phosphorylation. These data show that GIT1 is a key regulator of bone mass in vivo by regulating osteoclast function and suggest GIT1 as a potential target for osteoporosis therapy. J. Cell. Physiol. 225: 777–785, 2010. © 2010 Wiley‐Liss, Inc.
Modulation of sensory neuron‐specific receptors in the development of morphine tolerance and its neurochemical mechanisms
Authors: Chen Peiwen , Wang Dongmei , Li Meili , Zhang Yanding , Quirion Rémi , Hong Yanguo
Published: June 2010

Prevention of opiate tolerance is a critical issue in pain management. The present study was designed to characterize the pharmacological properties of sensory neuron‐specific receptors (SNSR; also known asMas‐related genereceptors, or Mrg) for their modulation in the development of morphine tolerance and to investigate the underlying mechanism(s). Daily coadministration of the SNSR agonist BAM8‐22 at a dose of 0.01 or 0.001, but not 1.0, nmol with morphine (intrathecally, or i.t., 20 μg/day) for 6 days significantly decreased the development of morphine tolerance. Coadministration of BAM8‐22 (i.t., 1.0 nmol) on days 1, 3, and 5 completely blocked tolerance to morphine‐induced analgesia. Intermittent coadministration of the structurally dissimilar SNSR agonist (Tyr6)‐2‐MSH‐6‐12 (MSH; 5 nmol) also produced similar modulation. Chronic administration of morphine (20 μg, i.t.) increased expression of neuronal nitric oxide synthase (nNOS) and calcitonin gene‐related peptide (CGRP) in superficial layers of the spinal cord and dorsal root ganglia. All these increases were abolished when BAM8‐22 or MSH was intermittently coadministered. Furthermore, intermittent administration of BAM8‐22 inhibited morphine‐induced increase in protein kinase Cγ (PKCγ) in both membrane and cytosol of spinal dorsal horn neurons. These results suggest that moderate activation of SNSR modulated morphine tolerance by inhibition of the PKC signaling pathway, leading to abolishment of enhancement of nNOS and CGRP. As SNSR are uniquely located ina subset of small‐sized neurons in dorsal root and trigeminal ganglia, intermittent combination of SNSR agonist could be a promising adjunct for sustained use of opiates without central nervous system side effects. © 2010 Wiley‐Liss, Inc.
Cross‐talk between STAT1 and PI3K/AKT signaling in HIV‐1‐induced blood–brain barrier dysfunction: Role of CCR5 and implications for viral neuropathogenesis
Authors: Yang Bo , Singh Sangya , Bressani Rafael , Kanmogne Georgette D.
Published: June 2010

How neuroinflammation affects signaling pathways leading to human blood–brain barrier (BBB) dysfunction during HIV‐1 infection is incompletely understood. We previously demonstrated that signal transducers and activators of transcription‐1 (STAT1) signaling is involved in HIV‐1 induced BBB damage and is relevant to viral neuropathogenesis. The objective of this study was to delineate the signaling pathways upstream and downstream of STAT1 involved in HIV‐1‐induced endothelial dysfunction. We show that HIV‐1 activation of STAT1 and STAT3 in human brain microvascular endothelial cells (HBMEC) is associated with induction of promoter activity of the interferon‐stimulated response element (ISRE)/interferon‐γ‐activated sequence (GAS). The STAT1 inhibitor fludarabine diminished HIV‐1‐induced ISRE/GAS promoter activity. CCR5 neutralizing antibodies and the phosphoinositide‐3‐kinase (PI3K) inhibitor LY‐294002 diminished HIV‐1‐induced phosphorylation of STAT1 and STAT3, significantly diminished HIV‐1‐induced ISRE/GAS promoter activity, and diminished virus‐induced monocyte adhesion and transendothelial migration. HIV‐1 infection did not phosphorylate janus kinases but induced activation of the phosphoinositide‐dependent kinase‐1 (PDK1) and the serine‐threonine protein kinase AKT, both downstream effectors of PI3K. CCR5 antibodies also diminished virus‐induced phosphorylation ofPDK1 and AKT. These results suggest that the chemokine receptor CCR5 is partially involved in HIV‐1 binding to HBMEC and show cross‐talk between STAT1 and PI3K pathways in HIV‐1‐induced BBB dysfunction. © 2010 Wiley‐Liss, Inc.
Characterization of Ir(ppy)3 and [Ir(ppy)2 bpy]+ by infrared, Raman spectra and surface‐enhanced Raman scattering
Authors: Lai Szu‐Hsueh , Ling Jung‐Wei , Huang Yu‐Min , Huang Min‐Jie , Cheng Chien Hung , Chen I‐Chia
Published: June 2010

The Raman and infrared spectra of fac‐tris(2‐phenylpyridinato‐N,C2′)iridium(III), Ir(ppy)3 and surface‐enhanced resonance Raman spectra of bis(2‐phenyl pyridinato‐) (2,2′bipyridine) iridium (III), [Ir(ppy)2 (bpy)]+ cation were recorded in the wavenumber range 150–1700 cm−1, and complete vibrational analyses of Ir(ppy)3 and [Ir(ppy)2 (bpy)]+ were performed. Most of the vibrational wavenumbers were calculated with density‐functional theory agree with experimental data. On the basis of the results of calculation and comparison of the spectra of both complexes and their analogue [Ru(bpy)3]2+, we assign the vibrational wavenumbers for metal–ligand modes; metal–ligand stretching wavenumbers are 277/307 and 261/236 cm−1 for Ir(ppy)3, and 311/324, 257/270, 199/245 cm−1 for [Ir(ppy)2 bpy]+. Surface‐enhanced Raman scattering spectra of [Ir(ppy)2 bpy]2+ were measured at two wavelengths on the red and blue edges of the low‐energy metal‐to‐ligand charge‐transfer band. According to the enhanced Raman intensities for the vibrational modes of both ligands ppy and bpy, the unresolved charge‐transfer band is deduced to consist of charge‐transfer transitions from the triplet metal to both ligands ppy and bpy. Copyright © 2010 John Wiley & Sons, Ltd.
Chromatographic fingerprint study on Evodia rutaecarpa (Juss.) Benth by HPLC/DAD/ESI‐MSn technique
Authors: Zhou Xin , Zhao Yang , Lei Peihai , Cai Zongwei , Liu Hai
Published: June 2010

The LC–ESI‐MSn method was developed for the analysis and characterization of alkaloids in the extract of E. rutaecarpa (called Wuzhuyu in Chinese). Thirty‐six batches of Wuzhuyu from different locations of China were investigated and the common fingerprinting profile was established with a professional analytical software recommended by the State Food and Drug Administration. Fifteen chemical components of the common peaks were identified by multi‐stage MS. The effects on the chromatographic profile resulting from different collecting locations, harvesting times or storage times were studied. Hierarchical clustering analysis and principal components analysis were also performed to classify and differentiate the 36 batches of the samples. As a result, those which had same chemical properties were sorted into one cluster, which was very useful in evaluating and controlling the quality of Wuzhuyu.
Understanding the benefits of social tourism: Linking participation to subjective well‐being and quality of life
Authors: McCabe Scott , Joldersma Thea , Li Chunxiao
Published: June 2010

This paper aims to explore the relationship between well‐being, quality of life and holiday participation among low‐income families in the UK. There have been very studies that have examined quality of life (QOL) and subjective well‐being in relation to tourism and none that have attempted to apply measures to assess the benefits of holidays for those people who are generally excluded from participation. This is important in relation to social tourism because of the fundamental need to develop mechanisms to evaluate the impact of charitable funding for supporting low‐income families' participation in holidaymaking. This study evaluates the types of reasons given for financial assistance in applications to the Family Holiday Association including follow‐up research with a sample of successful applicants on the perceived benefits of the holiday, including questions on QOL factors. The findings are limited in scope but do indicate that increases in QOL were reported among low‐income families. The paper concludes by arguing that further research on adapted well‐being and QOL measures be applied to tourism consumption. Copyright © 2010 John Wiley & Sons, Ltd.
Endoscopic frontal sinusotomy—Preventing recurrence or a route to revision?
Authors: Philpott Carl M. , Thamboo Andrew , Lai Leo , Park Jei , Javer Amin R.
Published: June 2010

Objectives/Hypothesis:

The Messerklinger technique is an endoscopic approach to sinus surgery designed to be minimally invasive and preserve mucosa and therefore physiological function. More recently there have been advocates for more radical endoscopic approaches to the frontal sinus such as the modified Lothrop procedure. This study aims to determine the effectiveness of endoscopic frontal sinusotomy in preventing recurrent frontal sinus disease and the need for any revision frontal sinus surgery.

Study Design:

Retrospective data review.

Methods:

A retrospective review of the chronic rhinosinusitis database at St. Paul's Sinus Centre was performed, randomly selecting 200 patients who had undergone primary bilateral functional endoscopic sinus surgery between 2000 and 2009. Any endoscopic or radiological recurrences listed on the database were counted along with the number of cases returned to theater for revision surgery. The preoperative Lund‐Mackay score was also extracted from the database.

Results:

In the 200 patients who had undergone their primary surgery at St. Paul's Hospital, the recurrence rate of frontal sinus disease was 19%, with less than one half (8%) requiring revision surgery. The Lund‐Mackay scores showed no correlation between disease severity and the incidence of recurrence (P = .35), and there was no difference between polyp and nonpolyp forms of chronic rhinosinusitis (P = .14). A comparison with 100 patients in the database who had received their primary surgery at another center showed that the revision patients had a recurrence rate of 34% and a revision rate of 21%. The patients who did not receive surgical revision were treated satisfactorily with topical medications in the outpatient clinic.

Conclusions:

Meticulously performed endoscopic frontal sinusotomy with computer guidance appears to be an effective minimally invasive procedure to treat chronic frontal sinusitis secondary to outflow tract obstruction. Properly performed, it is effective in dealing with the most diseased frontal sinus. It offers clear advantages in reducing complications and recurrence rates in frontal sinus disease even in revision cases. Laryngoscope, 2010
Prevalence of laryngomalacia in children presenting with sleep‐disordered breathing
Authors: Thevasagayam Mahilravi , Rodger Kirsty , Cave Dominic , Witmans Manisha , El‐Hakim Hamdy
Published: June 2010

Objective:

To determine the prevalence of laryngomalacia among children presenting with symptoms of sleep‐disordered breathing (SDB).

Method:

A retrospective observational study was conducted at a tertiary care paediatric hospital. All children presenting with SDB during a 55‐month period were investigated using sleep nasopharyngoscopy (SNP). Patients who had laryngomalacia were identified. Patients who did not present primarily with SDB, or were not examined with SNP were excluded. Data for analysis was collected from a prospectively kept surgical database and medical records. This included patients' demographics, symptoms (including symptoms in infancy), diagnoses, SNP findings, overnight pulse oximetry findings, and treatment.

Results:

We identified 358 patients with documented primary diagnosis of SDB and who had undergone SNP. Fourteen of these also had a documented diagnosis of laryngomalacia, giving a prevalence rate of 3.9%. Three children were syndromic, and one had cerebral palsy in addition to SDB and laryngomalacia. Three children were obese, and three children had gastroesophageal reflux disease. Seven cases (50%) had symptoms of snoring and/or swallowing dysfunction and/or stridor in infancy. Twelve patients had adenotonsillar surgery. In eight cases symptoms resolved completely with adenotonsillar surgery only. In total, six patients had a supraglottoplasty. There were three failures to supraglottoplasty.

Conclusion:

The prevalence of laryngomalacia within children presenting with SDB is 3.9%. Our findings support full evaluation of the airway to identify the site of pathology mediating SDB symptoms. Laryngoscope, 2010
What spatial light modulators can do for optical microscopy
Authors: Maurer C. , Jesacher A. , Bernet S. , Ritsch‐Marte M.
Published: June 2010

With the availability of high‐resolution miniature spatial light modulators (SLMs) new methods in optical microscopy have become feasible. The SLMs discussed in this review consist of miniature liquid crystal displays with micron‐sized pixels that can modulate the phase and/or amplitude of an optical wavefront. In microscopy they can be used to control and shape the sample illumination, or they can act as spatial Fourier filters in the imaging path. Some of these applications are reviewed in this article. One of them, called spiral phase contrast, generates isotropic edge enhancement of thin phase samples or spiral‐shaped interference fringes for thicker phase samples, which can be used to reconstruct the phase topography from a single on‐axis interferogram. If SLMs are used for both illumination control and spatial Fourier filtering, this combination for instance allows for the generalization of the Zernike phase contrast principle. The new SLM‐based approach improves the effective resolution and avoids some shortcomings and artifacts of the traditional method. The main advantage of SLMs in microscopy is their flexibility, as one can realize various operation modes in the same setup, without the need for changing any hardware components, simply by electronically switching the phase pattern displayed on the SLMs.
Study on corrosive electrochemical behaviors of zinc‐rich and graphite‐filled epoxy coatings in 3.5 wt% NaCl solution
Authors: Liu J. , Wang F. , Park K. C.
Published: June 2010

Environment behaviors and degradation mechanisms of two organic epoxy coatings coated on carbon steel sheets in 3.5 wt% NaCl neutral solution were studied by electrochemical impedance measurements and atomic force microscopy (AFM). The results showed that the coating resistance (Rp) of the graphite‐filled epoxy coating tested, which presents the film barrier performance, is higher than those of 6101 epoxy resin for initial seawater immersion, but the coating resistance of the zinc‐rich epoxy coating was lower than that of 6101 epoxy resin. After salt spray tests, zinc‐rich epoxy coating coated on the metal still has good anti‐corrosion performances due to the existence of protection effects called “electrochemical” and “chemical” protection. Those behaviors and degradation mechanisms of two coatings can be explained by a series of measured electrochemical impedance spectroscopy measurements, and two equivalent circuit models were proposed to explain the degradation processes of the two organic coatings.
Electrochemical stability and surface analysis in evaluation fluoride effect on new bioalloy Ti7Al3V2Mo2Fe used in dentistry
Authors: Ionita D. , Prodana M. , Demetrescu I. , Stanciu S. G. , Stanciu G. A.
Published: June 2010

The aim of this study is focused on the effect of fluoride concentration on the corrosion behavior of Ti7Al3V2Mo2Fe alloys uncoated/coated in artificial saliva. Ti7Al3V2Mo2Fe alloys were covered by chemical methods with hydroxyapatite to enhance the osteointegration of implants materials. The stability of Ti7Al3V2Mo2Fe alloys uncoated/coated in artificial saliva with/without fluoride ions was studied by electrochemical techniques (open circuit potential, cyclic voltammetry, and linear polarization). On the covered samples, dissolution test in simulated body fluids and wettability test were performed. Investigations regarding the sample surface modifications were made by atomic force microscopy and Fourier transform infrared spectroscopy. The results show that the corrosion resistance of Ti7Al3V2Mo2Fe in solution containing fluoride decreases in comparison with that in a solution not containing fluoride. Significant changes appear at a concentration larger than 0.05 M. The coating has a positive effect on corrosion resistance of metallic substrate in the fluoride presence acting as a semi‐mechanical barrier.
Synthesis and properties of all solid polymer electrolytes based on poly(vinyl acetate‐co‐acetyl ethylene oxide acrylate)
Authors: Zhou Shuhua , Kim Dukjoon
Published: June 2010

Poly(acetyl ethylene oxide acrylate‐co‐vinyl acetate) (P(AEOA‐VAc)) was synthesized and used as a host for lithium perchlorate to prepare an all solid polymer electrolyte. Introduction of carbonyl groups into the copolymer increased ionic conductivity. All solid polymer electrolytes based on P(AEOA‐VAc) at 14.3 wt% VAc with 12wt% LiClO4 showed conductivity as high as 1.2 × 10−4 S cm−1 at room temperature. The temperature dependence of the ionic conductivity followed the VTF behavior, indicating that the ion transport was related to segmental movement of the polymer. FTIR was used to investigate the effect of the carbonyl group on ionic conductivity. The interaction between the lithium salt and carbonyl groups accelerated the dissociation of the lithium salt and thus resulted in a maximum ionic conductivity at a salt concentration higher than pure PAEO‐salts system. Copyright © 2010 John Wiley & Sons, Ltd.
Fabrication and transport properties of poly(N‐vinylcarbazole)‐cellulose triacetate Langmuir‐Schaefer films
Authors: Basavaraja C. , Jo Eun Ae , Huh Do Sung
Published: June 2010

Cellulose triacetate (CTA) was doped with poly(N‐vinylcarbazole) during the oxidative polymerization of N‐vinylcarbazole using ferric chloride as an initiator to form polymer blends. The blends were characterized by Fourier transform infrared and UV‐vis spectroscopy. The surface morphology was further studied using both scanning electron microscopy and transmission electron microscopy. Langmuir‐Schaefer films of the polymer blends were fabricated. The DC conductivity of the polymer films at room temperature was found to increase with an increase in CTA content up to a value of 0.001 S cm−1. The temperature‐dependent DC conductivity of the polymer films studied in the range of 300–500 K shows an increase in conductivity with an increase in temperature indicating a semiconducting behavior with a negative temperature coefficient of resistivity. The apparent activation energy also showed a pronounced effect with an increase in the temperature as well as an increase in the content of CTA. POLYM. COMPOS., 2011. © 2010 Society of Plastics Engineers
Separating stress and time dependent effects in the temperature dependent creep of polyethylene nanocomposites
Authors: Shaito Ali , Fairbrother Debora , Sterling Jerry , D'Souza Nandika Anne
Published: June 2010

The nonlinear time dependent creep of linear‐low density polyethylene (LLDPE) reinforced with montmorillonite layered silicate was investigated. A previous study related the time/stress dependence of creep compliance of the material at room temperature using the Burger and Kohlrausch‐Williams‐Watts models. Using both the creep and recovery compliance curves, we employ the Schapery formulation to study the relationship between deformation, time, stress, and temperature of LLDPE nanocomposites. Smooth mastercurves are constructed using time–temperature–stress superposition principles. The stress and temperature‐related creep constants and shift factors were determined for the material using the Schapery nonlinear viscoelastic equation. The prediction results confirm the enhanced creep resistance of nanofillers even at extended time scales and low temperatures. POLYM. ENG. SCI., 50:1646–1657, 2010. © 2010 Society of Plastics Engineers
Maintenance and differentiation of neural stem cells
Authors: Massirer Katlin B. , Carromeu Cassiano , Griesi‐Oliveira Karina , Muotri Alysson R.
Published: June 2010

The adult mammalian brain contains self‐renewable, multipotent neural stem cells (NSCs) that are responsible for neurogenesis and plasticity in specific regions of the adult brain. Extracellular matrix, vasculature, glial cells, and other neurons are components of the niche where NSCs are located. This surrounding environment is the source of extrinsic signals that instruct NSCs to either self‐renew or differentiate. Additionally, factors such as the intracellular epigenetics state and retrotransposition events can influence the decision of NSC's fate into neurons or glia. Extrinsic and intrinsic factors form an intricate signaling network, which is not completely understood. These factors altogether reflect a few of the key players characterized so far in the new field of NSC research and are covered in this review. WIREs Syst Biol Med 2011 3 107–114 DOI: 10.1002/wsbm.100

This article is categorized under:

Developmental Biology > Stem Cell Biology and Regeneration
Enzyme replacement therapy in a patient with Fabry disease and the development of IgE antibodies against agalsidase beta but not agalsidase alpha
Authors: Tanaka Akemi , Takeda Taisuke , Hoshina Takao , Fukai Kazuyoshi , Yamano Tsunekazu
Published: June 2010

Fabry disease is an X‐linked inherited lysosomal storage disorder caused by an inborn deficiency of the enzyme α‐galactosidase A. Enzyme replacement therapy (ERT) with agalsidase alpha or beta isozymes is an effective treatment. Cross‐reactivity of immunoglobulin G (IgG) antibodies with agalsidase alpha and beta has been reported, but no such reaction has been recorded for IgE antibodies. We present the case of a patient with Fabry disease who developed antiagalsidase beta IgE antibodies without cross‐reactivity to agalsidase alpha. A 17‐year‐old boy with Fabry disease had suffered from severe atopic dermatitis since infancy, and he complained for several years of peripheral pain during the summer months and when exercising. Fabry disease was confirmed by family history and a positive enzyme test, and ERT was commenced. Following infusion of agalsidase beta (1.0 mg/kg), the patient complained of a high temperature in his hands and feet, and purulent eczema developed. The infusion dose was reduced to 0.2 mg/kg, but the hyperthermia did not change, although its duration decreased. After three infusions, eosinophilia developed (9.4%; 573 cells/μl blood) and remained unresolved after four infusions with agalsidase beta. Treatment with this enzyme was discontinued, and agalsidase alpha (0.2 mg/kg) started. This produced immediate resolution of the eosinophilia, which has been maintained during follow‐up. In conclusion, this patient developed IgE antibodies against agalsidase beta, which demonstrated no cross‐reactivity to agalsidase alpha. These findings emphasize the importance of analyzing IgE antibodies against both enzymes when patients exhibit severe infusion‐related events.
Medium‐chain acyl‐CoA dehydrogenase deficiency in Saudi Arabia: incidence, genotype, and preventive implications
Authors: Al‐Hassnan Zuhair N. , Imtiaz Faiqa , Al‐Amoudi Mohamed , Rahbeeni Zuhair , Al‐Sayed Moeen , Al‐Owain Mohammed , Al‐Zaidan Hamad , Al‐Odaib Ali , Rashed Mohamed S.
Published: June 2010

Medium‐chain acyl‐CoA dehydrogenase deficiency (MCADD), caused by mutated ACADM gene, is a potentially fatal fatty acid oxidation defect. Detection of MCADD is now part of tandem mass spectrometry (MS‐MS)‐based newborn screening programs worldwide. To date, more than 67 mutations have been reported to cause MCADD with a single allele, c.985A>G, being the most common in patients of northwestern European descent. In Saudi Arabia, the Newborn Screening Program, officially launched in 2005, screens for 16 disorders including MCADD. Over a period of 3 years, 237,812 newborns were screened; 13 were identified to have MCADD giving an incidence of 1:18,293. Since the introduction of MS‐MS to our institution, however, a total of 30 patients were detected to have MCADD. These cases were either newborns, at high‐risk family members, or clinically suspected. The C8‐carnitine levels (median 3.31, range 0.81–16.33 µM) were clearly diagnostic in all analyzed samples. Sequencing ACADM in 20 DBS revealed two novel mutations: c.362C>T (p.T121I) and c.347G>A (p.C116Y) substitutions, neither of which were detected in 300 chromosomes from controls. Eighteen (90%) patients were homozygous for the T121I mutation and two (10%) were compound heterozygous (T121I/C116Y). Our molecular data lend further support to MS‐MS biochemical screening for MCADD and provide evidence for the relatively high incidence of MCADD in the Arab population. The identification of a founder mutation for MCADD has important implications for the preventive screening programs not only in Saudi Arabia but potentially also in other countries in the region.
Quantitation of Hydroperoxy‐, Keto‐ and Hydroxy‐Dienes During Oxidation of FAMEs from High‐Linoleic and High‐Oleic Sunflower Oils
Authors: Morales Arturo , Dobarganes Carmen , Márquez‐Ruiz Gloria , Velasco Joaquín
Published: June 2010

The objective of this work was to study the quantitative formation of hydroperoxydienes, ketodienes and hydroxydienes during autoxidation at 40 °C of fatty acid methyl esters derived from two sunflower oils with different degree of unsaturation, high‐linoleic sunflower oil and high‐oleic sunflower oil. The analysis of the oxidation compounds was carried out by NP‐HPLC–UV and results were compared to the specific extinction at 232 nm (K232) and the peroxide value (PV). Analysis of FAME polymers by HPSEC was also performed to discard samples of advanced oxidation. Results showed that the contents of hydroperoxydienes with respect to the PV were higher for the high linoleic (HL) sample. At the end of the period of slow polymerization (ΔPol ≤ 1 wt%), the content of hydroperoxydienes was found to be 86.0 and 30.7 μg/mg for the HL and high oleic (HO) samples, respectively. Throughout this period, hydroperoxydienes constituted around 90 and 50 wt% of the total hydroperoxides in the HL and HO samples, respectively, suggesting that a significant oxidation of oleic acid also occurred in both samples. The contents of ketodienes and hydroxydienes as a whole constituted 2–3 wt% of the diene compounds analyzed at the end of the period of slow polymerization. Higher contents of ketodienes than of hydroxydienes were found throughout the oxidation time, and the ratio between the contents of ketodienes and hydroxydienes increased with a factor that changed from 1 to 2 throughout the period of slow polymerization.
Brief report: Cross‐informant ratings of self‐ and other‐regulation at career transitions in adolescence
Authors: Dietrich Julia , Kracke Bärbel
Published: June 2010

Individual initiative is required to successfully master career transitions in adolescence, and also parents play an important role in this process. Past research largely omitted co‐agency in transition‐related activities between adolescents and their parents, which could be described in terms of self‐ and other‐regulation. The present pilot study examined adolescents’ and mothers’ career‐specific regulatory behaviors as perceived from both agents’ perspectives. 38 German adolescents rated importance and engagement in one transition‐related personal goal and reported on intensity of career exploration activities. Furthermore, they reported on their perceptions of mothers’ career‐related behaviors and confidence in their offspring's transition management. All measures were also assessed from the mothers’ point of view. Results revealed associations within and across family members’ ratings that showed similarities as well as differences in perceptions of how behaviors associate. Partial correlation analyses showed that specific maternal behavior not contingent upon her general warmth associated with child behavior.
Dissociation In Non-clinical And Clinical Sample Of Czech Adolescents. Reliability And Validity Of The Czech Version Of The Adolescent Dissociative Experiences Scale
Authors: Soukup J. , Papežová H. , Kuběna A.A. , Mikolajová V.
Published: June 2010

Objective

The purpose of this study was to examine psychometric properties of the Czech language version of the Adolescent Dissociative Experiences Scale (A-DES) [2].

Method

653 non-clinical participants and 162 adolescent psychiatric inpatients completed Czech versions of the A-DES and the Somatoform Dissociation Questionnaire (SDQ-20), and provided further information (data regarding demographic variables, diagnoses, further psychopathology).

Results

The Czech A-DES has very good internal consistency, test-retest reliability and a good validity, though its predictive power is limited. The ADES scores significantly correlate with the measure of somatoform dissociation, a presence of clinician-observed dissociative symptoms, reported traumatic experiences, self injurious behavior, and polysymptomatic diagnostic picture. A-DES scores were significantly higher in ADHD group, but not in a group with a diagnosis of a dissociative disorder.

Conclusion

The authors stress that all adolescent psychiatric patients who show more complex behavioral disturbances, have histories of trauma, show self-injurious behaviors or have ADHD diagnosis should be screened for dissociation.
Involvement of the Hipk family in regulation of eyeball size, lens formation and retinal morphogenesis
Authors: Inoue Toshihiro , Kagawa Tetsushi , Inoue-Mochita Miyuki , Isono Kyoichi , Ohtsu Naoki , Nobuhisa Ikuo , Fukushima Mikiko , Tanihara Hidenobu , Taga Tetsuya
Published: June 2010

Members of the homeodomain‐interacting protein kinase (HIPK) family are involved in various intracellular regulatory mechanisms. The present study focused on clarifying the functions of HIPK family members in ocular organization during late embryogenesis. HIPK1 and HIPK2 were expressed in the inner retina during late embryogenesis. Hipk1
+/− Hipk2
−/− mice had a greater frequency of small eyes with a lens deficiency and abnormally laminated and thickened retinas than did wild‐type littermates. These data indicate that Hipk1 and Hipk2 are involved in regulation of eye size, lens formation and retinal lamination during late embryogenesis.
Agile manufacturing: Relation to JIT, operational performance and firm performance
Authors: Inman R. Anthony , Sale R. Samuel , Green Kenneth W. , Whitten Dwayne
Published: June 2010

A structural model incorporating agile manufacturing as the focal construct is theorized and tested. The model includes the primary components of JIT (JIT‐purchasing and JIT‐production) as antecedents and operational performance and firm performance as consequences to agile manufacturing. Using data collected from production and operations managers working for large U.S. manufacturers, the model is assessed following a structural equation modeling methodology. The results indicate that JIT‐purchasing has a direct positive relationship with agile manufacturing while the positive relationship between JIT‐production and agile manufacturing is mediated by JIT‐purchasing. The results also indicate that agile manufacturing has a direct positive relationship with the operational performance of the firm, that the operational performance of the firm has a direct positive relationship with the marketing performance of the firm, and that the positive relationship between the operational performance of the firm and the financial performance of the firm is mediated by the marketing performance of the firm.
Late Quaternary glaciation and equilibrium-line altitudes of the Mayan Ice Cap, Guatemala, Central America
Authors: Roy Alex J. , Lachniet Matthew S.
Published: June 2010

The Sierra los Cuchumatanes (3837 m), Guatemala, supported a plateau ice cap and valley glaciers around Montaña San Juan (3784 m) that totaled ∼ 43 km2 in area during the last local glacial maximum. Former ice limits are defined by sharp-crested lateral and terminal moraines that extend to elevations of ∼ 3450 m along the ice cap margin, and to ca. 3000–3300 m for the valley glaciers. Equilibrium-line altitudes (ELAs) estimated using the area–altitude balance ratio method for the maximum late Quaternary glaciation reached as low as 3470 m for the valley glaciers and 3670 m for the Mayan Ice Cap. Relative to the modern altitude of the 0°C isotherm of ∼ 4840 m, we determined ELA depressions of 1110–1436 m. If interpreted in terms of a depression of the freezing level during maximal glaciation along the modern lapse rate of − 5.3°C km–1, this ΔELA indicates tropical highland cooling of ∼ 5.9 to 7.6 ± 1.2°C. Our data support greater glacial highland cooling than at sea level, implying a high tropical sensitivity to global climate changes. The large magnitude of ELA depression in Guatemala may have been partially forced by enhanced wetness associated with southward excursions of the boreal winter polar air mass.
Localization and function ofRhipicephalus (Boophilus) microplusvitellin-degrading cysteine endopeptidase
Authors: SEIXAS ADRIANA , ESTRELA ANDRÉIA B. , CEOLATO JULIANA C. , PONTES EMERSON G. , LARA FLÁVIO , GONDIM KATIA C. , TERMIGNONI CARLOS
Published: June 2010

The tickRhipicephalus (Boophilus) microplusis an important parasite of cattle in many areas of the tropics. Characterization of molecules involved in mechanisms such as vitellogenesis and embryo development may contribute to a better understanding of this parasite's physiology. The vitellin-degrading cysteine endopeptidase (VTDCE) is the most active enzyme involved in vitellin hydrolysis inR. micropluseggs. Here we show an association between VTDCE and vitellin in an additional site, apart from the active site. Our data also demonstrate cysteine endopeptidase activity in different tissues such as ovary, gut, fat body, salivary gland and female haemolymph, where it is controlled by a physiological inhibitor. InR. microplusfemale gut, VTDCE is localized in areas of protein synthesis and trafficking with the underlying haemolymph. VTDCE is also localized in the ovary basal region, in vesicle membranes of ovary pedicel cells and in oocyte cytosol. These results suggest that VTDCE plays a role in vitellin digestion during tick development.
Use of fluorescent probes as a useful tool to identify resistantSchistosoma mansoniisolates to praziquantel
Authors: COUTO F. F. B. , COELHO P. M. Z. , ARAÚJO N. , KUSEL J. R. , KATZ N. , MATTOS A. C. A.
Published: June 2010

The use of chemotherapy on a mass scale in endemic areas may lead to the appearance of resistant isolates through the mechanism of selective drug pressure. Studies have demonstrated that praziquantel (PZQ) is able to inhibit the excretory activity and to cause tegumental damage inSchistosoma mansoniadult worms. The use of the probe resorufin to evaluate excretory activity, as well as the probe Hoechst 33258 to detect tegumental damage in adult worms, may represent a method to identify resistant (or less susceptible) isolates. The purpose of the present work was to compare the changes caused by PZQ in the function of the excretory system and in the integrity of the tegument of adult worms from the LE isolate (susceptible to PZQ) and the LE-PZQ isolate (less susceptible to PZQ). Worms from the isolate LE-PZQ showed less severe tegumental lesions, in bothin vitroandin vivoexperiments, detected by labelling with Hoechst 33258 and continued to have a functional excretory system as shown by labelling with resorufinin vitro.