bluuebunny/crossref_metadata_2025_split huggingface dataset:
Internalization of EGF receptor following lipid rafts disruption in keratinocytes is delayed and dependent on p38 MAPK activation
Authors: Lambert Sylviane , Ameels Hélène , Gniadecki Robert , Hérin Michel , Poumay Yves 
Published: August 2008

AbstractThe receptor for epidermal growth factor (EGF) plays an important role in epidermal keratinocytes and is known to move out of lipid raft after cholesterol depletion, leading to ligand‐independent activation. Accumulation of evidence indicates the ability of EGF receptor (EGFR) to undergo internalization without participation of the ligand under the control of p38 MAPK during stress conditions. Since cholesterol depletion using methyl‐beta‐cyclodextrin is known to induce ligand‐independent activation of EGFR in keratinocytes, we investigated by confocal microscopy and ligand‐binding tests the processing and localization of EGFR following lipid raft disruption. Here, we report the dimerization and the slow internalization of the receptor accompanied by the delayed phosphorylation of tyrosine 1068 and its degradation by the proteasome. We also demonstrate the involvement of p38 MAPK during the process of internalization, which can be considered as a protective response to stress. Moreover, cholesterol‐depleted keratinocytes recover their ability to proliferate during the recovery period that follows lipid raft disruption. J. Cell. Physiol. 217: 834–845, 2008. © 2008 Wiley‐Liss, Inc.
Low dose beta‐blocker prevents ovariectomy‐induced bone loss in rats without affecting heart functions
Authors: Bonnet N. , Benhamou C.L. , Malaval L. , Goncalves C. , Vico L. , Eder V. , Pichon C. , Courteix D. 
Published: August 2008

AbstractFindings from animal studies have suggested that bone remodeling is under beta‐adrenergic control. However, the level of adrenergic inhibition required to achieve the most favorable effects on the skeleton remains unknown. To address this question, we compared the effects of low (0.1 mg/Kg/day), medium (5 mg/Kg/day) or high (20 mg/Kg/day) doses of propranolol given 5 days per week for 10 weeks in ovariectomized (OVX) rats. Characteristics of bone microarchitecture, biomechanical properties and bone turnover were investigated, whilst heart functions were assessed by echocardiography and catheterization of the left ventricle. We first confirmed the expression of Adrβ2R and the absence of Adrβ1R on osteoblasts by PCR and confocal microscopy. We then showed that low dose propranolol prevented OVX induced bone loss by increasing bone formation (+30% of MAR vs. placebo, P = 0.01) and decreasing bone resorption (−52% of osteoclast surface on bone surface vs. placebo, P = 0.01). Consequently, rats receiving 0.1 mg/kg/day propranolol displayed higher stress (+27%), intrinsic energy (+28.7%) and Young's Modulus in compression versus placebo (all, P < 0.05). No significant effects on heart hemodynamic parameters were found in rats receiving this dose. In contrast, medium and high doses of propranolol had a negative effect on heart functions but no significant protective effects on bone mass in ovariectomized rats. These results, consistent with the dominant nature of the high bone mass phenotype and normal heart function of Adrβ2R‐deficient mice, suggest that low doses of β‐blockers may have a therapeutic utility in the treatment of osteoporosis with high selectivity for bone tissues. J. Cell. Physiol. 217: 819–827, 2008. © 2008 Wiley‐Liss, Inc.
Calpain‐mediated androgen receptor breakdown in apoptotic prostate cancer cells
Authors: Yang Huanjie , Murthy Shalini , Sarkar Fazlul H. , Sheng Shijie , Reddy G. Prem‐Veer , Dou Q. Ping 
Published: August 2008

AbstractSince androgen receptor (AR) plays an important role in prostate cancer development and progression, androgen‐ablation has been the frontline therapy for treatment of advanced prostate cancer even though it is rarely curative. A curative strategy should involve functional and structural elimination of AR from prostate cancer cells. We have previously reported that apoptosis induced by medicinal proteasome‐inhibitory compound celastrol is associated with a decrease in AR protein levels. However celastrol‐stimulated events contributing to this AR decrease have not been elucidated. Here, we report that a variety of chemotherapeutic agents, including proteasome inhibitors, a topoisomerase inhibitor, DNA‐damaging agents and docetaxel that cause cell death, decrease AR levels in LNCaP prostate cancer cells. This decrease in AR protein levels was not due to the suppression of AR mRNA expression in these cells. We observed that a proteolytic activity residing in cytosol of prostate cancer cells is responsible for AR breakdown and that this proteolytic activity was stimulated upon induction of apoptosis. Interestingly, proteasome inhibitor celastrol‐ and chemotherapeutic drug VP‐16‐stimulated AR breakdown was attenuated by calpain inhibitors calpastatin and N‐acetyl‐L‐leucyl‐L‐leucyl‐L‐methioninal. Furthermore, AR proteolytic activity pulled down by calmodulin‐agarose beads from celastrol‐treated PC‐3 cells showed immunoreactivity to a calpain antibody. Taken together, these results demonstrate calpain involvement in proteasome inhibitor‐induced AR breakdown, and suggest that AR degradation is intrinsic to the induction of apoptosis in prostate cancer cells. J. Cell. Physiol. 217: 569–576, 2008. © 2008 Wiley‐Liss, Inc.
The effect of differentiation on 1,25 dihydroxyvitamin D‐mediated gene expression in the enterocyte‐like cell line, Caco‐2
Authors: Cui Min , Klopot Anna , Jiang Yan , Fleet James C. 
Published: August 2008

AbstractWe examined 1,25 dihydroxyvitamin D (1,25(OH)2D3)‐induced expression of 25‐hydroxyvitamin D3 24‐hydroxylase (CYP24) and apical calcium channel (TRPV6) mRNA levels in 2‐, 9‐, and 15‐day cultures Caco‐2 cells that model proliferating, post‐proliferative, and differentiated enterocytes. 1,25(OH)2D3‐induced (10 nM, 8 h) CYP24 and TRPV6 mRNA levels were significantly greater in differentiated and post‐proliferative than proliferating Caco‐2 cells (>16X and >3X, respectively). Neither CYP24 mRNA half‐life nor induction of a −298 bp rat CYP24 promoter‐luciferase reporter construct (10 nM 1,25(OH)2D3, 24 h) were different between proliferating and post‐proliferating Caco‐2 cells. We next tested whether the blunted response of natural genes to 1,25(OH)2D3 in proliferating Caco‐2 cells is due to altered chromatin remodeling. VDR and coactivator protein levels do not increase with differentiation but the level of the co‐repressor Alien falls by 50% with differentiation. Over‐expression of Alien reduced 1,25(OH)2D3‐induced activity of a minimal VDRE containing promoter‐luciferase construct by more than 60% in differentiated Caco‐2 cells while siRNA knockdown of Alien in proliferating Caco‐2 cells increased 1,25(OH)2D3‐induced CYP24 mRNA level by 40%. These observations suggest that Alien is a regulator of VDR‐mediated gene transcription in Caco‐2 cells. In addition, we found that 1,25(OH)2D3‐induced association of VDR with chromatin and with the CYP24 promoter was lower in proliferating cells. This suggests that decreased recruitment of VDR to vitamin D response elements also contributes to the blunted transcriptional responsiveness to 1,25(OH)2D3 in proliferating Caco‐2 cells. J. Cell. Physiol. 218: 113–121, 2009. © 2008 Wiley‐Liss, Inc.
Composition and significance of detergent resistant membranes in mouse spermatozoa
Authors: Nixon Brett , Bielanowicz Amanda , Mclaughlin Eileen A. , Tanphaichitr Nongnuj , Ensslin Michael A. , Aitken R. John 
Published: August 2008

AbstractMammalian spermatozoa acquire the ability to fertilize an oocyte as they ascend the female reproductive tract. This process is characterized by a complex cascade of biophysical and biochemical changes collectively know as “capacitation.” The attainment of a capacitated state is accompanied by a dramatic reorganization of the surface architecture to render spermatozoa competent to recognize the oocyte and initiate fertilization. Emerging evidence indicates that this process is facilitated by molecular chaperone‐mediated assembly of a multimeric receptor complex on the sperm surface. However, the mechanisms responsible for gathering key recognition molecules within this putative complex have yet to be defined. In this study, we provide the first evidence that chaperones partition into detergent resistant membrane fractions (DRMs) within capacitated mouse spermatozoa and co‐localize in membrane microdomains enriched with the lipid raft marker, GM1 ganglioside. During capacitation, these microdomains coalesce within the apical region of the sperm head, a location compatible with a role in sperm–zona pellucida interaction. Significantly, DRMs isolated from spermatozoa possessed the ability to selectively bind to the zona pellucida of unfertilized, but not fertilized, mouse oocytes. A comprehensive proteomic analysis of the DRM fractions identified a total of 100 proteins, a number of which have previously been implicated in sperm–oocyte interaction. Collectively, these data provide compelling evidence that mouse spermatozoa possess membrane microdomains that provide a platform for the assembly of key recognition molecules on the sperm surface and thus present an important mechanistic insight into the fundamental cell biological process of sperm–oocyte interaction. J. Cell. Physiol. 218: 122–134, 2009. © 2008 Wiley‐Liss, Inc.
First‐trimester prenatal sonographic diagnosis of omphalocele‐exstrophy‐imperforate anus‐spinal defects complex
Authors: Wax Joseph R. , Pinette Michael G. , Smith Rosemarie , Cartin Angelina , Blackstone Jacquelyn 
Published: August 2008

AbstractWe describe a case of omphalocele‐exstrophy‐imperforate anus‐spinal defects (OEIS) diagnosed at 13 weeks' gestation by ultrasound detection of a large multilocular ventral wall mass into which inserted the umbilical cord, and thoracic hemivertebrae with kyphoscoliosis. Subsequent sonographic examinations at 16 and 19 weeks revealed evolution of the ventral wall mass into a classic omphalocele. Clinicians should recognize the significance of a large multicystic ventral wall mass, which should lead to a search for other anomalies suggestive of OEIS complex. © 2008 Wiley Periodicals, Inc. J Clin Ultrasound, 2009
Reappraisal of endosonography of ampullary tumors: Correlation with transabdominal sonography, CT, and MRI
Authors: Chen Chien‐Hua , Yang Chi‐Chieh , Yeh Yung‐Hsiang , Chou Der‐Aur , Nien Chiu‐Kue 
Published: August 2008

AbstractPurpose.To reappraise the accuracy of transabdominal sonography (US), CT, MRI, and endosonography (EUS) in the diagnosis and staging of ampullary tumors.Method.We reviewed the medical records and the images of 41 consecutive patients with ampullary tumors. Tumor detection rate and accuracy of TNM (tumor–node–metastasis) staging of malignant tumors were determined. Imaging findings were correlated with histopathologic findings.Results.The detection rates for ampullary tumors were 97.6% for EUS, 81.3% for MRI, 28.6% for CT, and 12.2% for US (p < 0.001 for EUS versus CT; p < 0.001 for EUS versus US; p > 0.05 for EUS versus MRI). The accuracy in T staging for ampullary carcinomas was 72.7% for EUS, 53.8% for MRI, and 26.1% for CT (p < 0.01 for EUS versus CT; p > 0.05 for EUS versus MRI). The accuracy in N staging for ampullary carcinomas was 66.7% for EUS, 76.9% for MRI, and 43.5% for CT with no statistically significant difference between the 3 modalities. The sensitivity in detecting malignant lymph nodes was 46.7% for EUS, 25.0% for MRI, and 0% for CT (p < 0.01 for EUS versus CT; p > 0.05 for EUS versus MRI; p > 0.05 for MRI versus CT). Transpapillary stenting, advanced tumor extension (>T2), large tumor size (>2 cm), tumor differentiation, and endoscopic appearance of tumor growth did not significantly influence EUS accuracy in T or N staging (p > 0.05).Conclusion.EUS was superior to CT and was equivalent to MRI for tumor detection and T and N staging of ampullary tumors. Neither indwelling stents nor tumor size, differentiation, or endoscopic appearance affected the staging accuracy of EUS. © 2008 Wiley Periodicals, Inc. J Clin Ultrasound, 2009
Sustained baculovirus‐mediated expression in myogenic cells
Authors: Shen Heng‐Chun , Yeh Chia‐Ni , Chen Guan‐Yu , Huang Shiu‐Feng , Chen Chi‐Yuan , Chiu Yung‐Chung , Hu Yu‐Chen 
Published: August 2008

AbstractBackgroundBaculovirus has emerged as a promising gene delivery vector due to its low cytotoxicity and nonreplication nature in mammalian cells. However, baculovirus‐mediated expression is transient and generally lasts less than 14 days, which could restrict its application in the treatment of diseases requiring stable transgene expression.MethodsWe transduced myoblast cell lines C2C12, Sol 8 and primary myoblasts with a baculovirus expressing the enhanced green fluorescent protein (EGFP) under the control of cytomegalovirus immediate‐early promoter and measured the transduction efficiency by flow cytometry. Myogenic differentiation was induced after transduction and the longevity of EGFP expression was monitored by fluorescence microscopy. The myogenic differentiation was confirmed by reverse transcription‐polymerase chain reaction (RT‐PCR). The persistence of the egfp DNA and transcripts was monitored by real‐time PCR and quantitative real‐time RT‐PCR.ResultsBaculovirus efficiently transduced C2C12, Sol 8 and the primary myoblasts. The transgene expression persisted for a prolonged period of time (at least 63 days) in the cells differentiating into myotubes, but was transient in HeLa cells (<7 days). The sustained expression paralleled the myogenic differentiation and stemmed from the intracellular persistence of egfp DNA and mRNA.ConclusionsThe transgene delivered by baculovirus persists in the myotubes and endows sustained expression, which is distinct from its rapid degradation and transient expression in other cell types. These findings justify the future use of baculovirus for muscle‐based gene therapy. Copyright © 2008 John Wiley & Sons, Ltd.
Triangulations and the Hajós conjecture
Authors: Rödl Vojtěch , Zich Jan 
Published: August 2008

AbstractIn his recent work Thomassen [J Combin Theory Ser B 93 (2005), 95–105] discussed various refinements of Hajós conjecture. Shortly after Mohar [Electr J Combin 12 (2005), N15] provided an answer to Thomassen's Conjecture 6.5, and proposed a possible extension. The aim of this article is to address Mohar's suggestion. In particular, we prove that, for infinitely many integers m, there exists a graph on m vertices forming a triangulation of an orientable surface so that it does not contain a subdivision of a clique of size $O(m^{1/2})$ , and its chromatic number is at least $m^{{2/3} + o(1)}$. The main part of the proof is to show that the random graph can be almost covered by oriented triangles which do not contain certain forbidden configurations. We use a technique similar to the ones of Archdeacon and Grable [Discrete Math 142(1–3)(1995), 21–37] and Thomas and the first author [Random Struct Algorithms 6(1) (1995), 1–12]. We obtain a strengthening by replacing the “nibble” method by “random bites” used by Alon et al. [Israel J Math 100 (1997), 171–187]. © 2008 Wiley Periodicals, Inc. J Graph Theory 59: 293–325, 2008
The size of edge chromatic critical graphs with maximum degree 6
Authors: Luo Rong , Miao Lianying , Zhao Yue 
Published: August 2008

AbstractIn 1968, Vizing [Uaspekhi Mat Nauk 23 (1968) 117–134; Russian Math Surveys 23 (1968), 125–142] conjectured that for any edge chromatic critical graph ${{G}} = ({{V}}, {{E}})$ with maximum degree $\Delta$, $|{{E}}| \geq {{{1}}\over {{2}}}\{(\Delta {{- 1}})|{{V}}| + {{3}}\}$. This conjecture has been verified for $\Delta \leq {{5}}$. In this article, by applying the discharging method, we prove the conjecture for $\Delta = {{6}}$. © 2008 Wiley Periodicals, Inc. J Graph Theory 60: 149–171, 2009
Development of 99mTc‐thioflavin‐T derivatives for detection of systemic amyloidosis
Authors: Serdons K. , Verduyckt T. , Cleynhens J. , Bormans G. , Verbruggen A. 
Published: August 2008

AbstractIn a search for a 99mTc‐labelled tracer agent for imaging of amyloid plaques in patients with systemic amyloidosis (SA), we have conjugated three bifunctional chelating ligands, namely S‐benzyl‐mercaptoacetyl‐l‐aspartyl(tBu)‐glycine, HYdrazinoNICotinic acid and nitrilotriacetic acid, to the 2‐phenylbenzothiazole core of thioflavin‐T (ThT), which has known affinity for amyloid. The compounds were successfully synthesized and labelled with technetium‐99m. Their structure was confirmed by radio‐LC‐MS analysis. After i.v. injection in normal mice, all three 99mTc‐labelled ThT derivatives were excreted almost exclusively via liver and intestines. This indicates that the new tracer agents have not the required biokinetics for application as a probe for detection of SA in the abdominal region. Copyright © 2008 John Wiley & Sons, Ltd.
A human spinal cord cell promotes motoneuron survival and maturation in vitro
Authors: Rouleau Caroline , Mersel Marcel , de Weille Jan , Rakotoarivelo Clovis , Fabre Christine , Privat Alain , Langley Keith , Petite Didier 
Published: August 2008

AbstractPrimary cultures of motoneurons represent a good experimental model for studying mechanisms underlying certain spinal cord pathologies, such as amyotrophic lateral sclerosis and spinal bulbar muscular atrophy (Kennedy's disease). However, a major problem with such culture systems is the relatively short cell survival times, which limits the extent of motoneuronal maturation. In spite of supplementing culture media with various growth factors, it remains difficult to maintain motoneurons viable longer than 10 days in vitro. This study employs a new approach, in which rat motoneurons are plated on a layer of cultured cells derived from newborn human spinal cord. For all culture periods, more motoneurons remain viable in such cocultures compared with control monocultures. Moreover, although no motoneurons survive in control cultures after 22 days, viable motoneurons were observed in cocultures even after 7 weeks. Although no significant difference in neurite length was observed between 8‐day mono‐ and cocultures, after 22 and 50 days in coculture motoneurons had a very mature morphology. They extended extremely robust, very long neurites, which formed impressive branched networks. Data obtained using a system in which the spinal cord cultures were separated from motoneurons by a porous polycarbonate filter suggest that soluble factors released from the supporting cells are in part responsible for the beneficial effects on motoneurons. Several approaches, including immunocytochemistry, immunoblotting, and electron microscopy, indicated that these supporting cells, capable of extending motoneuron survival and enhancing neurite growth, had an undifferentiated or poorly differentiated, possibly mesenchymal phenotype. © 2008 Wiley‐Liss, Inc.
Mitochondrial dysfunction disrupts trafficking of Kir4.1 in spiral ganglion satellite cells
Authors: Zou Jing , Zhang Ya , Yin Shankai , Wu Hao , Pyykkö Ilmari 
Published: August 2008

AbstractThe inward‐rectifier K+channel Kir4.1 is responsible for maintaining cochlear homeostasis and restoring neural excitability. The large‐conductance calcium‐activated K+channel (BKCa) plays a key role in phase locking signals in the mammalian inner ear. To evaluate the influence of mitochondrial dysfunction on the expression and subcellular localization of these channels, 3‐nitropropionic acid (3‐NP) was administered to rat round window membranes for 30 min. Auditory brainstem response was measured both before and 2 hr after 3‐NP administration. Immunofluorescent confocal microscopy was used to measure the expression and subcellular localization of Kir4.1 and BKCa. Alexa Fluor 568‐labeled bovine serum albumin (BSA) was applied to round window membranes as a tracer to explore the cochlear distribution of drug delivery and was detected in the lateral wall, spiral ganglion, cochlear nerve, and organ of Corti. Hearing loss of 23 (±4.4 SE) and 58 (±6.7 SE) dB developed in rats treated with 0.3 and 0.5 mol/liter of 3‐NP, respectively. BKCawas visualized in the cellular membrane and cytoplasm in the upper and middle region of inner hair cells, and it was not affected by 3‐NP. Kir4.1 was detected in intermediate cells of the stria, Deiter's cells, and spiral ganglion satellite cells. Kir4.1 failed to reach the perineural cytoplasm of the satellite cells after 3‐NP treatment. The results of this study suggest that mitochondrial dysfunction disrupts trafficking of Kir4.1 in spiral ganglion satellite cells. © 2008 Wiley‐Liss, Inc.
Increases in transient receptor potential vanilloid‐1 mRNA and protein in primary afferent neurons stimulated by protein kinase C and their possible role in neurogenic inflammation
Authors: Xu Xijin , Wang Peng , Zou Xiaoju , Li Dingge , Fang Li , Lin Qing 
Published: August 2008

AbstractA recent study by our group demonstrates pharmacologically that the transient receptor potential vanilloid‐1 (TRPV1) is activated by intradermal injection of capsaicin to initiate neurogenic inflammation by the release of neuropeptides in the periphery. In this study, expression of TRPV1, phosphorylated protein kinase C (p‐PKC), and calcitonin gene‐related peptide (CGRP) in dorsal root ganglion (DRG) neurons was visualized by using immunofluorescence, real‐time PCR, and Western blots to examine whether increases in TRPV1mRNA and protein levels evoked by capsaicin injection are subject to modulation by the activation of PKC and to analyze the role of this process in the pathogenesis of neurogenic inflammation. Capsaicin injection into the hindpaw skin of anesthetized rats evoked increases in the expression of TRPV1, CGRP and p‐PKC in mRNA and/or protein levels and in the number of single labeled TRPV1, p‐PKC, and CGRP neurons in ipsilateral L4‐5 DRGs. Coexpressions of TRPV1with p‐PKC and/or CGRP in DRG neurons were also significantly increased after CAP injection. These evoked expressions at both molecular and cellular levels were significantly inhibited after TRPV1receptors were blocked by 5′‐iodoresiniferatoxin (5 μg) or PKC was inhibited by chelerythrine chloride (5 μg). Taken together, these results provide evidence that up‐regulation of TRPV1mRNA and protein levels under inflammatory conditions evoked by capsaicin injection is subject to modulation by the PKC cascade in which increased CGRP level in DRG neurons may be related to the initiation of neurogenic inflammation. Thus, up‐regulation of TRPV1receptors in DRG neurons seems critical for initiating acute neurogenic inflammation. © 2008 Wiley‐Liss, Inc.
The development and evaluation of a soil moisture index
Authors: Hunt Eric D. , Hubbard Kenneth G. , Wilhite Donald A. , Arkebauer Timothy J. , Dutcher Allen L. 
Published: August 2008

AbstractSoil water is an important parameter in the hydrological balance and is essential for understanding land–surface interactions. While spatial coverage of soil water observations is poor across most of the United States, impedance probes have been used to measure soil water throughout Nebraska in the Automated Weather Data Network (AWDN) since 1999. With 8 years of continuous data at selected sites, we were able to derive a Soil Moisture Index (SMI) that is based on an actual water content (θ) and a known field capacity and wilting point. The SMI is a continuous function and is scaled from 5.0 to − 5.0, with 5.0 representing θ at field capacity and − 5.0 representing θ at wilting point. Since the inception of the soil water network in 1999, periodic episodes of drought have affected all areas of Nebraska. Thus, the SMI was used in this study to analyse growing seasons (1 April to 1 October) from 1999 to 2006 at six selected sites throughout Nebraska. The SMI proved to be effective at depicting the onset of drought and at identifying soil recharge, or lack thereof, when heavy rainfall events followed a significant dry spell. Copyright © 2008 Royal Meteorological Society