bluuebunny/crossref_metadata_2025 huggingface dataset:
Differential Stereocontrolled Formation of Tricyclic Triterpenes by Mutation of Tyrosine 99 of the Oxidosqualene‐Lanosterol Cyclase from Saccharomyces cerevisiae
Authors: Wu Tung‐Kung , Li Wen‐Hsuan , Chang Cheng‐Hsiang , Wen Hao‐Yu , Liu Yuan‐Ting , Chang Yi‐Chun
Published: September 2009

The function of the Tyr99 residue from Saccharomyces cerevisiae oxidosqualene‐lanosterol cyclase (ERG7) was analyzed by constructing deletion and site‐saturated mutants. Two truncated intermediates, (13αH)‐isomalabarica‐14Z,17E,21‐trien‐3β‐ol and (13αH)‐isomalabarica‐14E,17E,21‐trien‐3β‐ol, were isolated from the ERG7Y99X mutants. These results suggest that the functional role of ERG7Y99 is to affect both chair–boat 6–6–5 tricyclic Markovnikov C‐14 cation stabilization and thestereochemistry of the protons at the C‐15 position for subsequent deprotonation. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Novel Synthesis of 4H‐Quinolizine Derivatives Using Sulfonyl Ketene Dithioacetals
Authors: Hagimori Masayori , Matsui Sayaka , Mizuyama Naoko , Yokota Kenichirou , Nagaoka Junko , Tominaga Yoshinori
Published: September 2009

In the synthesis of 4H‐quinolizine derivatives involving the use of a sulfonyl ketene dithioacetal, we found a novel reaction in which the remaining methylsulfanyl group was replaced with a proton after the ring‐closure reaction in the quinolizine skeleton under mild conditions, without the use of any metallic reagent. The reaction of 3,3‐bis(methylsulfanyl)‐2‐phenylsulfonylacrylonitriles (1a,b) with 2‐pyridylacetonitrile (2a) in the presence of potassium carbonate as a base in DMSO afforded 4‐imino‐2‐methylsulfanyl‐3‐phenylsulfonyl‐4H‐quinolizine‐1‐carbonitriles (3a,b). The methylsulfanyl group at the 2‐position of 3a,b was readily removed under methanol reflux conditions to afford 4‐imino‐3‐phenylsulfonyl‐4H‐quinolizine‐1‐carbonitriles (4a,b) in good yields. Alkyl 3‐phenylsulfonyl‐4H‐quinolizine‐1‐carboxylates (4c–f) were directly synthesized from sulfonyl ketene dithioacetal (1a,b) with alkyl 2‐pyridylacetates (2b,c) and involved desulfanylation by simple hydrolysis. In addition, the fluorescent properties of these compounds were investigated. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Nonisothermal two‐ and three‐dimensional flow simulations of inelastic and viscoelastic fluids by a finite‐volume method
Authors: Khalifeh Ahmad , Clermont Jean‐Robert
Published: September 2009

This paper applies the finite‐volume method to computations of steady flows of viscous and viscoelastic incompressible fluids in complex two and three‐dimensional geometries. The materials adopted in the study obey different constitutive laws: Newtonian, purely viscous Carreau–Yasuda as also Upper‐Convected Maxwell and Phan‐Thien/Tanner differential models, with a Williams–Landel–Ferry (WLF) equation for temperature dependence. Specific analyses are made depending on the rheological model. A staggered grid is used for discretizing the equations and unknowns. Stockage possibilities allow us to solve problems involving a great number of degrees of freedom, up to 1 500 000 unknowns with a desk computer. In relation to the fluid properties, our numerical simulations provide flow characteristics for various 2D and 3D configurations and demonstrate the possibilities of the code to solve problems involving complex nonlinear constitutive equations with thermal effects. Copyright © 2009 John Wiley & Sons, Ltd.
Cell‐context specific role of the E2F/Rb pathway in development and disease
Authors: Swiss Victoria A. , Casaccia Patrizia
Published: September 2009

Development of the central nervous system (CNS) requires the generation of neuronal and glial cell subtypes in appropriate numbers, and this demands the careful coordination of cell‐cycle exit, survival, and differentiation. The E2F/Rb pathway is critical for cell‐cycle regulation and also modulates survival and differentiation of distinct cell types in the developing and adult CNS. In this review, we first present the specific temporal patterns of expression of the E2F and Rb family members during CNS development and then discuss the genetic ablation of single or multiple members of these two families. Overall, the available data suggest a time‐dependent and cell‐context specific role of E2F and Rb family members in the developing and adult CNS. © 2009 Wiley‐Liss, Inc.
Role of glutamate and its receptors and insulin‐like growth factors in hypoxia induced periventricular white matter injury
Authors: Sivakumar Viswanathan , Ling Eng‐Ang , Lu Jia , Kaur Charanjit
Published: September 2009

This study investigated the glutamate concentration and cellular localization of α‐amino‐3‐hydroxy‐5‐methyl‐4‐isoxazole propionic acid glutamate receptors (AMPA GluR2, GluR3, GluR4) along with insulin‐like growth factors (IGF)‐1 and ‐2 expression in the periventricular white matter (PWM) of neonatal rats with the aim to determine their involvement in PWM injury in hypoxia. In response to hypoxia, the PWM tissue concentration of glutamate and IGF‐1 as well as mRNA and protein expression of GluR2, GluR3, GluR4, IGF‐1, and ‐2 was upregulated. Immunoexpression of GluR2/3 and GluR4 were localized in the amoeboid microglial cells (AMC) and oligodendrocytes while that of IGF‐1 and ‐2 were confined to AMC. In primary microglial cultures subjected to hypoxia, administration of exogenous glutamate decreased IGF‐1 but increased the release of tumor necrosis factor‐α (TNF‐α) and interleukin‐1β (IL‐1β) by the cells. Furthermore, silencing of the IGF‐1 and ‐2 genes by RNA interference in primary microglial cultures and BV‐2 cells downregulated the expression of these growth factors whereas production of glutamate, TNF‐α, and IL‐1β in these cells was upregulated. It is suggested that increased IGF‐1 and ‐2 expressions may be an early protective mechanism in attenuating the hypoxic damage in PWM but a subsequent glutamate‐induced decrease of these growth factors may cause cellular injury due to excitotoxicity and increased production of inflammatory cytokines. In this connection, melatonin and edaravone were beneficial in enhancing IGF‐1 and reducing glutamate release. © 2009 Wiley‐Liss, Inc.
Tumor suppressor function of Rab25 in triple‐negative breast cancer
Authors: Cheng Ji‐Ming , Volk Lisa , Janaki Deepak Kumar Mummidavarapu , Vyakaranam Sudhir , Ran Sophia , Rao Krishna A.
Published: September 2009

Rab proteins are a group of ubiquitously expressed proteins that are responsible for intracellular transport of vesicles. Recent evidence has shown that certain Rab proteins are involved in the pathogenesis of cancer. We have recently shown that Rab25 is lost in a large fraction of breast cancer samples, particularly those derived from hormonally insensitive tumors. We have further investigated the role of Rab25 by re‐expressing Rab25 in tumorigenic cell lines and measuring the impact on tumor formation as well as on various molecular pathways through PCR array analysis. In vivo tumor growth of cell lines with re‐expressed Rab25 was markedly suppressed. Our data suggest that Rab25 acts through multiple pathways to enhance apoptosis and to suppress angiogenesis and invasion by modulating VEGF‐A and VEGFR‐1 expression. These findings suggest that Rab25 represents a novel class of cellular modulators that can influence both tumor initiation and the progression of the established tumors, thus ultimately affecting the biology of the malignant disease.
Snail is critical for tumor growth and metastasis of ovarian carcinoma
Authors: Jin Hongyan , Yu Yinhua , Zhang Tao , Zhou Xianrong , Zhou Jiayi , Jia Luoqi , Wu Yadi , Zhou Binhua P. , Feng Youji
Published: September 2009

Snail, a key inducer of epithelial‐mesenchymal transition (EMT), plays an important role in cancer metastasis. To better understand the role of Snail in the metastasis of ovarian carcinoma, expression of Snail was knocked down by antisense‐Snail in the highly metastatic ovarian cancer cell line HO8910PM. Gene array analysis revealed that blocking Snail expression suppressed the activity of matrix metalloproteinases (MMPs) and upregulated TIMP3, an MMP inhibitor. These findings suggest that Snail interacts with MMP during tumor invasion and metastasis. In addition, we examined the role of Snail in an ovarian cancer orthotopic model by using the antisense‐Snail HO8910PM cell line. We found that the size of primary ovarian cancer tumor and the number of metastatic lesions were significantly reduced when Snail was knocked down. Confirming our initial findings, the activity of MMP2 was greatly inhibited in tumors from antisense‐Snail cells. Furthermore, immunohistochemical analysis on ovarian cancer progression tissue array demonstrated that the expression of Snail was significantly higher in metastatic lesions, and Snail expression correlated with the stage of ovarian cancer. Interestingly, in early‐stage tumors, Snail was localized in both the cytoplasm and nucleus. In late stage and metastatic lesions, the level of Snail was elevated, and Snail was localized to the nucleus. The expression level and nuclear localization of Snail were also inversely correlated with E‐cadherin expression. Overall, our study indicates that Snail plays a critical role in tumor growth and metastasis of ovarian carcinoma through regulation of MMP activity.
Immunohistochemical detection of tyrosine phosphatase SHP‐1 predicts outcome after radical prostatectomy for localized prostate cancer
Authors: Tassidis Helena , Brokken Leon J.S. , Jirström Karin , Ehrnström Roy , Pontén Fredrik , Ulmert David , Bjartell Anders , Härkönen Pirkko , Wingren Anette Gjörloff
Published: September 2009

The protein tyrosine kinase (PTK) receptors and cytosolic signaling proteins as well as the protein tyrosine phosphatases (PTPs) have important roles in regulation of growth of the benign and malignant prostate gland. Here, we studied expression of the protein tyrosine phosphatase SHP‐1 in prostate cancer cell lines and in human prostatic tissues. SHP‐1 is expressed at a high level in LNCaP prostate cancer cells compared with PC3 cells. Silencing of SHP‐1 expression with siRNA in LNCaP cells led to an increased rate of proliferation, whereas overexpression of SHP‐1 by means of transient and stable transfection in PC3 cells led to a decrease in proliferation. Corresponding changes were observed in cyclin D1 expression. We further demonstrate that LNCaP and PC3 cells respond differently to IL‐6 stimulation. SHP‐1 overexpression in PC3 cells reversed IL‐6 stimulation of proliferation, whereas in SHP‐1‐silenced LNCaP cells, IL‐6 inhibition of proliferation was not affected. In addition, IL‐6 treatment led to higher levels of phosphorylated STAT3 in SHP‐1‐silenced LNCaP cells than in control cells. Next, SHP‐1 expression in human prostate cancer was analyzed by immunohistochemical staining of tissue microarrays comprising tumor specimens from 100 prostate cancer patients. We found an inverse correlation between the tumor level of SHP‐1 expression and time to biochemical recurrence and clinical progression among prostate cancer patients. In conclusion, our results suggest that a decreased level of SHP‐1 expression in prostate cancer cells is associated with a high proliferation rate and an increased risk of recurrence or clinical progression after radical prostatectomy for localized prostate cancer.
Evidence for tissue factor phosphorylation and its correlation with protease‐activated receptor expression and the prognosis of primary breast cancer
Authors: Rydén Lisa , Grabau Dorthe , Schaffner Florence , Jönsson Per‐Ebbe , Ruf Wolfram , Belting Mattias
Published: September 2009

Tissue factor (TF)‐mediated protease‐activated receptor (PAR)‐2 signaling is associated with a promigratory, invasive and proangiogenic phenotype in experimental models of breast cancer and has been mechanistically coupled to phosphorylation of the TF cytoplasmic domain (pTF). However, the clinical relevance of these findings is unknown. Here, we provide the first in vivo evidence of TF phosphorylation in experimental as well as clinical breast cancer tumors. pTF was demonstrated in MDA‐MB‐231 xenografts and in tumors from the MMTV‐PyMT transgene model of spontaneous murine breast adenocarcinoma. Tumors from PAR‐2–deficient transgenic mice were negative for pTF, thus linking pTF to PAR‐2 signaling. The clinical correlation between TF, pTF, PAR‐1, PAR‐2 and vascular endothelial growth factor (VEGF)‐A was determined by immunohistochemistry on tumors from a cohort of 172 consecutive primary breast cancer patients, with a median follow‐up time of 50 months. In 160 evaluable patient tumors, pTF was associated with TF (p = 0.01) and cancer cell expression of PAR‐1 (p = 0.001), PAR‐2 (p = 0.014) and VEGF‐A (p = 0.003) using χ2 test. PAR‐2 and VEGF‐A were coexpressed (p = 0.013) and associated with a more aggressive phenotype. Interestingly, all patients experiencing recurrences had tumors expressing pTF and PAR‐2, and pTF alone as well as coexpression of pTF and PAR‐2 were significantly correlated with shorter recurrence‐free survival (log rank test, p = 0.04 and p = 0.02, respectively). This study provides the first evidence to link PAR‐2 expression and TF phosphorylation to clinical data in human breast cancer. In conjunction with experimental tumor models, these data support an important role of TF‐PAR‐2 signaling in breast cancer recurrence.
Unifying roles for regulatory T cells and inflammation in cancer
Authors: Erdman Susan E. , Rao Varada P. , Olipitz Werner , Taylor Christie L. , Jackson Erin A. , Levkovich Tatiana , Lee Chung‐Wei , Horwitz Bruce H. , Fox James G. , Ge Zhongming , Poutahidis Theofilos
Published: September 2009

Activities of CD4+ regulatory (TREG) cells restore immune homeostasis during chronic inflammatory disorders. Roles for TREG cells in inflammation‐associated cancers, however, are paradoxical. It is widely believed that TREG function in cancer mainly to suppress protective anticancer responses. However, we demonstrate here that TREG cells also function to reduce cancer risk throughout the body by efficiently downregulating inflammation arising from the gastrointestinal (GI) tract. Building on a “hygiene hypothesis” model in which GI infections lead to changes in TREG that reduce immune‐mediated diseases, here we show that gut bacteria‐triggered TREG may function to inhibit cancer even in extraintestinal sites. Ability of bacteria‐stimulated TREG to suppress cancer depends on interleukin (IL)‐10, which serves to maintain immune homeostasis within bowel and support a protective antiinflammatory TREG phenotype. However, under proinflammatory conditions, TREG may fail to provide antiinflammatory protection and instead contribute to a T helper (Th)‐17‐driven procarcinogenic process; a cancer state that is reversible by downregulation of inflammation. Consequently, hygienic individuals with a weakened IL‐10 and TREG‐mediated inhibitory loop are highly susceptible to the carcinogenic consequences of elevated IL‐6 and IL‐17 and show more frequent inflammation‐associated cancers. Taken together, these data unify seemingly divergent disease processes such as autoimmunity and cancer and help explain the paradox of TREG and inflammation in cancer. Enhancing protective TREG functions may promote healthful longevity and significantly reduce risk of cancer.
Regulation of REDD1 by insulin‐like growth factor‐I in skeletal muscle and myotubes
Authors: Frost Robert A. , Huber Danuta , Pruznak Anne , Lang Charles H.
Published: September 2009

Insulin‐like growth factor‐I (IGF‐I) is a major anabolic hormone for skeletal muscle and a potent stimulus for protein synthesis and translation initiation. Recent studies suggest that translation can be inhibited by over expression of the mammalian target of rapamycin (mTOR) repressor REDD1. The purpose of the present study was to determine whether IGF‐I alters the expression of REDD1 and whether this is associated with a concomitant change in protein synthesis in vitro. Subcutaneous injection of IGF‐I or intravenous delivery of insulin for 3–4 h increased REDD1 mRNA in skeletal muscle 7–10‐fold. A threefold increase in REDD1 was observed when C2C12 myotubes were treated with IGF‐I. REDD1 protein continued to be expressed for up to 24 h after addition of IGF‐I to cells. Withdrawal of IGF‐I from myotubes lead to a rapid loss of REDD1 protein content. IGF‐I‐induced REDD1 mRNA and protein expression were prevented by inhibitors of transcription and translation. IGF‐I had an additive effect with dexamethasone (Dex) on REDD1 protein content in myotubes. The PI3K inhibitor LY294002 blocked IGF‐I but not Dex induced REDD1. IGF‐I also stimulated REDD1 promoter activity. Although REDD1 protein was elevated 5–6 h after addition of IGF‐I to myotubes, protein synthesis measured during this 1 h window was paradoxically greater in myotubes expressing more REDD1. In contrast to the IGF‐I induced increase in REDD1 mRNA, REDD2 mRNA was decreased by IGF‐I. We conclude that IGF‐I stimulates REDD1 expression in skeletal muscle and myotubes but under these conditions the REDD1 response is not sufficient to repress protein synthesis. J. Cell. Biochem. 108: 1192–1202, 2009. © 2009 Wiley‐Liss, Inc.
Altered protein‐expressing profile in hPNAS4‐induced apoptosis in A549 human lung adenocarcinoma cells
Authors: Gou Lan‐Tu , Tong Ai‐Ping , Yan Fei , Yuan Zhu , He Fei , Wang Wei , Zhou Yan , Chen Li‐Juan , Tang Ming‐Hai , Yang Jin‐Liang
Published: September 2009

Human PNAS4 (hPNAS4) is a recently identified pro‐apoptosis gene, which is able to induce apoptosis in A549 human lung adenocarcinoma cells following its overexpression. In this work, we investigated the changes of protein profile in hPNAS4‐induced apoptosis in A549 cells through proteomic strategy consisting of two‐dimensional electrophoresis (2‐DE) coupled with MALDI‐Q‐TOF mass spectrometry. A total of 20 different proteins with more than 3.0‐fold change in expression, including 5 up‐regulated and 15 down‐regulated proteins were successfully identified by database search. The mRNA transcription levels of the different proteins were further examined by RT‐PCT. Functional analyses showed these different proteins are involved in diverse biological processes including metabolism, proteolysis, signal transduction, apoptosis, and redox regulation. Two essential apoptosis‐associated protein, annexin A1 and prothymosin alpha, were confirmed by Western blot and showed consistent changes with proteomic detection. Our data provide molecular evidence and possible associated pathway in hPNAS4‐induced apoptosis through proteomic strategy, which should be contributed to further investigation on biological function of hPNAS4. J. Cell. Biochem. 108: 1211–1219, 2009. © 2009 Wiley‐Liss, Inc.
Geometry and force control of cell function
Authors: Freytes Donald O. , Wan Leo Q. , Vunjak‐Novakovic Gordana
Published: September 2009

Tissue engineering is becoming increasingly ambitious in its efforts to create functional human tissues, and to provide stem cell scientists with culture systems of high biological fidelity. Novel engineering designs are being guided by biological principles, in an attempt to recapitulate more faithfully the complexities of native cellular milieu. Three‐dimensional (3D) scaffolds are being designed to mimic native‐like cell environments and thereby elicit native‐like cell responses. Also, the traditional focus on molecular regulatory factors is shifting towards the combined application of molecular and physical factors. Finally, methods are becoming available for the coordinated presentation of molecular and physical factors in the form of controllable spatial and temporal gradients. Taken together, these recent developments enable the interrogation of cellular behavior within dynamic culture settings designed to mimic some aspects of native tissue development, disease, or regeneration. We discuss here these advanced cell culture environments, with emphasis on the derivation of design principles from the development (the biomimetic paradigm) and the geometry‐force control of cell function (the biophysical regulation paradigm). J. Cell. Biochem. 108: 1047–1058, 2009. © 2009 Wiley‐Liss, Inc.
RNAi‐mediated silencing of insulin receptor substrate‐4 enhances actinomycin D‐ and tumor necrosis factor‐α‐induced cell death in hepatocarcinoma cancer cell lines
Authors: Cuevas Eva P. , Escribano Oscar , Monserrat Jorge , Martínez‐Botas Javier , Sánchez María G. , Chiloeches Antonio , Hernández‐Breijo Borja , Sánchez‐Alonso Verónica , Román Irene D. , Fernández‐Moreno Ma Dolores , Guijarro Luis G.
Published: September 2009

Insulin receptor substrate‐4 (IRS‐4) transmits signals from the insulin‐like growth factor receptor (IGF‐IR) and the insulin receptor (IR) to the PI3K/AKT and the ERK1/2 pathways. IRS‐4 expression increases dramatically after partial hepatectomy and plays an important role in HepG2 hepatoblastoma cell line proliferation/differentiation. In human hepatocarcinoma, IRS‐4 overexpression has been associated with tumor development. Herein, we describe the mechanism whereby IRS‐4 depletion induced by RNA interference (siRNA) sensitizes HepG2 cells to treatment with actinomycin D (Act D) and combined treatment with Act D plus tumor necrosis factor‐α (TNF‐α). Similar results have been obtained in HuH 7 and Chang cell lines. Act D therapy drove the cells to a mitochondrial‐dependent apoptotic program involving cytochrome c release, caspase 3 activation, PARP fragmentation and DNA laddering. TNF‐α amplifies the effect of Act D on HepG2 cell apoptosis increasing c‐jun N‐terminal kinase (JNK) activity, IκB‐α proteolysis and glutathione depletion. IRS‐4 depleted cells that were treated with Act D showed an increase in cytochrome c release and procaspase 3 and PARP proteolysis with respect to control cells. The mechanism involved in IRS‐4 action is independent of Akt, IκB kinase and JNK. IRS‐4 down regulation, however, decreased γ‐glutamylcysteine synthetase content and cell glutathione level in the presence of Act D plus TNF‐α. These results suggest that IRS‐4 protects HepG2 cells from oxidative stress induced by drug treatment. J. Cell. Biochem. 108: 1292–1301, 2009. © 2009 Wiley‐Liss, Inc.
Role of the low‐density lipoprotein receptor‐related protein‐1 in regulation of chondrocyte differentiation
Authors: Kawata Kazumi , Kubota Satoshi , Eguchi Takanori , Moritani Norifumi H. , Shimo Tsuyoshi , Kondo Seiji , Nishida Takashi , Minagi Shogo , Takigawa Masaharu
Published: September 2009

The low‐density lipoprotein receptor‐related protein 1 (LRP1) is known as an endocytic and signal transmission receptor. We formerly reported the gene expression and the localization of LRP1 in cartilage tissue and chondrocytes, but its roles in the differentiation of chondrocytes remained to be investigated. Here, in order to address this issue, we employed RNAi strategy to knockdown lrp1 in chondrocytic cells and obtained findings indicating a critical role therein. As a result of lrp1 knockdown, aggrecan and col2a1 mRNA levels were decreased. However, that of col10a1 or mmp13 mRNA was rather increased. Under this condition, we performed a promoter assay for Axin2, which is known to be induced by activation of the WNT/β‐catenin (βcat) signaling pathway. Thereby, we found that Axin2 promoter activity was enhanced in the lrp1 knockdown cells. Furthermore, when the WNT/β–catenin pathway was activated in chondrocytic cells by WNT3a or SB216763, which inhibits the phosphorylation of GSK3β, the mRNA levels of aggrecan and col2a1 were decreased, whereas that of mmp13 was increased. Additionally, the level of phosphorylated protein kinase C (PKC) ζ was also decreased in the lrp1 knockdown cells. When the phosphorylation of PKCζ was selectively inhibited, aggrecan and col2a1 mRNA levels decreased, whereas the mmp13 mRNA level increased. These data demonstrate that LRP1 exerts remarkable effects to retain the mature phenotype of chondrocytes as a critical mediator of cell signaling. Our findings also indicate that the onset of hypertrophy during endochondral ossification appears to be particularly dependent on the WNT and PKC signaling initiated by LRP1. J. Cell. Physiol. 222:138–148, 2010. © 2009 Wiley‐Liss, Inc.
Melanocytes in development and cancer
Authors: Uong Audrey , Zon Leonard I.
Published: September 2009

Melanocytes are pigment‐producing cells in the skin of humans and other vertebrates. A number of genes involved in melanocyte development and vertebrate pigmentation have been characterized, largely through studies of a diversity of pigment mutations in a variety of species. Embryonic development of the melanocyte initiates with cell fate specification in the neural crest, which is then followed by cell migration and niche localization. Many genes involved in melanocyte development have also been implicated in the development of melanoma, an aggressive and fatal form of skin cancer that originates in the melanocyte. Although early stage melanomas that have not spread to the lymph nodes can be excised with little risk of recurrence, patients diagnosed with metastatic melanoma have a high mortality rate due to the resistance of most tumors to radiotherapy and chemotherapy. Transformed melanocytes that develop into melanomas proliferate abnormally and often begin to grow radially in the skin. Vertical growth can then follow this radial growth, leading to an invasion through the basement membrane into the underlying dermis and subsequent metastasis. It is still unclear, however, how a normal melanocyte becomes a melanoma cell, and how melanoma utilizes the properties of the normal melanocyte and its progenitors in its progression. The goal of this mini‐review is to highlight the role of melanocyte developmental pathways in melanoma, and to discuss recent studies and tools being used to illuminate this connection. J. Cell. Physiol. 222:38–41, 2010. © 2009 Wiley‐Liss, Inc.
Low oxygen reduces the modulation to an oxidative phenotype in monolayer‐expanded chondrocytes
Authors: Heywood Hannah K. , Lee David A.
Published: September 2009

Autologous chondrocyte implantation requires a phase of in vitro cell expansion, achieved by monolayer culture under atmospheric oxygen levels. Chondrocytes reside under low oxygen conditions in situ and exhibit a glycolytic metabolism. However, oxidative phosphorylation rises progressively during culture, with concomitant reactive oxygen species production. We determine if the high oxygen environment in vitro provides the transformation stimulus. Articular chondrocytes were cultured in monolayer for up to 14 days under 2%, 5%, or 20% oxygen. Expansion under 2% and 5% oxygen reduced the rate at which the cells developed an oxidative phenotype compared to 20% oxygen. However, at 40 ± 4 fmol cell−1 h−1 the oxygen consumption by chondrocytes expanded under 2% oxygen for 14 days was still 14 times the value observed for freshly isolated cells. Seventy‐five to 78% of the increased oxygen consumption was accounted for by oxidative phosphorylation (oligomycin sensitive). Expansion under low oxygen also reduced cellular proliferation and 8‐hydroxyguanosine release, a marker of oxidative DNA damage. However, these parameters remained elevated compared to freshly isolated cells. Thus, expansion under physiological oxygen levels reduces, but does not abolish, the induction of an oxidative energy metabolism. We conclude that simply transferring chondrocytes to low oxygen is not sufficient to either maintain or re‐establish a normal energy metabolism. Furthermore, a hydrophobic polystyrene culture surface which promotes rounded cell morphology had no effect on the development of an oxidative metabolism. Although the shift towards an oxidative energy metabolism is often accompanied by morphological changes, this study does not support the hypothesis that it is driven by them. J. Cell. Physiol. 222:248–253, 2010. © 2009 Wiley‐Liss, Inc.
Huperzine a improves chronic inflammation and cognitive decline in rats with cerebral hypoperfusion
Authors: Wang Juan , Zhang Hai Yan , Tang Xi Can
Published: September 2009

Chronic cerebral hypoperfusion has been suggested to contribute to the progression of dementia. Inflammation and white matter lesion (WML) are involved in the pathologic process. This study investigated whether huperzine A, a natural acetylcholinesterase (AChE) inhibitor, has beneficial effects on long‐lasting inflammation as well as cognitive impairment in a rat model of cerebral hypoperfusion and how it plays these roles. Chronic cerebral hypoperfusion was induced by occlusion of bilateral common carotid arteries (two‐vessel occlusion; 2VO). Huperzine A was initially given 150 min after 2VO and daily for 3, 7, 14, and 28 days. Learning and memory dysfunction as tested by Morris water maze performance was observed in 2VO‐operated rats and was significantly improved by huperzine A treatment. WML and activation staining of immune cells were evaluated by Klüver‐Barrera (KB) and immunohistochemistry, respectively. Myelin damage and increased immunostains were found in optic tract at all indicated days. Huperzine A treatment significantly ameliorated all these phenomena. Moreover, huperzine A also suppressed overexpression of the inflammatory factor tumor necrosis factor‐α (TNF‐α) and overphosphorylation of JNK and p38 mitogen‐activated protein kinases (MAPKs) in a cell model of chronic hypoxia. Preincubation with mecamylamine (MEC), a nicotinic acetylcholine receptor (nAChR) antagonist, for 30 min before hypoxia notably reversed the effects of huperzine A on TNF‐α production and MAPKs phosphorylation. In conclusion, delayed and chronic administration of huperzine A could protect against 2VO‐induced cognitive impairment, which might be related to its beneficial effects on WML, and the nAChR‐dependent cholinergic anti‐inflammation pathway plays an important role. © 2009 Wiley‐Liss, Inc.
3‐nitropropionic acid‐induced mitochondrial permeability transition: Comparative study of mitochondria from different tissues and brain regions
Authors: Mirandola Sandra R. , Melo Daniela R. , Saito Ângela , Castilho Roger F.
Published: September 2009

The adult rat striatum is particularly vulnerable to systemic administration of the succinate dehydrogenase inhibitor 3‐nitropropionic acid (3NP), which is known to induce degeneration of the caudate‐putamen, as occurs in Huntington's disease. The aim of the present study was to compare the susceptibility of isolated mitochondria from different rat brain regions (striatum, cortex, and cerebellum) as well as from the liver, kidney, and heart to mitochondrial permeability transition (MPT) induced by 3NP and Ca2+. In the presence of micromolar Ca2+ concentrations, 3NP induces MPT in a dose‐dependent manner, as estimated by mitochondrial swelling and a decrease in the transmembrane electrical potential. A 3NP concentration capable of promoting a 10% inhibition of ADP‐stimulated, succinate‐supported respiration was sufficient to stimulate Ca2+‐induced MPT. Brain and heart mitochondria were generally more sensitive to 3NP and Ca2+‐induced MPT than mitochondria from liver and kidney. In addition, a partial inhibition of mitochondrial respiration by 3NP resulted in more pronounced MPT in striatal mitochondria than in cortical or cerebellar organelles. A similar inhibition of succinate dehydrogenase activity was observed in rat tissue homogenates obtained from various brain regions as well as from liver, kidney, and heart 24 hr after a single i.p. 3NP dose. Mitochondria isolated from forebrains of 3NP‐treated rats were also more susceptible to Ca2+‐induced MPT than those of control rats. We propose that the increased susceptibility of the striatum to 3NP‐induced neurodegeneration may be partially explained by its susceptibility to MPT, together with the greater vulnerability of this brain region to glutamate receptor‐mediated Ca2+ influx. © 2009 Wiley‐Liss, Inc.
NAD(P)H oxidase contributes to neurotoxicity in an excitotoxic/prooxidant model of Huntington's disease in rats: Protective role of apocynin
Authors: Maldonado P.D. , Molina‐Jijón E. , Villeda‐Hernández J. , Galván‐Arzate S. , Santamaría A. , Pedraza‐Chaverrí J.
Published: September 2009

Intrastriatal injection of quinolinic acid (QUIN) to rodents reproduces some biochemical, morphological, and behavioral characteristics of Huntington's disease. NAD(P)H oxidase is an enzymatic complex that catalyzes superoxide anion (O2·−) production from O2and NADPH. The present study evaluated the role of NAD(P)H oxidase in the striatal damage induced by QUIN (240 nmol/μl) in adult male Wistar rats by means of apocynin (APO; 5 mg/kg i.p.), a specific NAD(P)H oxidase inhibitor. Rats were given APO 30 min before and 1 hr after QUIN injection or only 30 min after QUIN injection. NAD(P)H oxidase activity was measured in striatal homogenates by O2·−production. QUIN infusion to rats significantly increased striatal NAD(P)H oxidase activity (2 hr postlesion), whereas APO treatments decreased the QUIN‐induced enzyme activity (2 hr postlesion), lipid peroxidation (3 hr postlesion), circling behavior (6 days postlesion), and histological damage (7 days postlesion). The addition of NADH to striatal homogenates increased NAD(P)H oxidase activity in striata from QUIN‐treated animals but not from sham rats. Interestingly, O2·−production in QUIN‐lesioned striata was unaffected by the addition of substrates for intramitochondrial O2·−production, xanthine oxidase and nitric oxide synthase, suggesting that NAD(P)H oxidase may be the main source of O2·−in QUIN‐treated rats. Moreover, the administration of MK‐801 to rats as a pretreatment resulted in a complete prevention of the QUIN‐induced NAD(P)H activation, suggesting that this toxic event is completely dependent on N‐methyl‐D‐aspartate receptor overactivation. Our results also suggest that NAD(P)H oxidase is involved in the pathogenic events linked to excitotoxic/prooxidant conditions. © 2009 Wiley‐Liss, Inc.
Rapid assessment of internodal myelin integrity in central nervous system tissue
Authors: Kirschner Daniel A. , Avila Robin L. , Gamez Sazo Rodolfo E. , Luoma Adrienne , Enzmann Gaby U. , Agrawal Deepika , Inouye Hideyo , Bunge Mary Bartlett , Kocsis Jeffery , Peters Alan , Whittemore Scott R.
Published: September 2009

Monitoring pathology/regeneration in experimental models of de‐/remyelination requires an accurate measure not only of functional changes but also of the amount of myelin. We tested whether X‐ray diffraction (XRD), which measures periodicity in unfixed myelin, can assess the structural integrity of myelin in fixed tissue. From laboratories involved in spinal cord injury research and in studying the aging primate brain, we solicited “blind” samples and used an electronic detector to record rapidly the diffraction patterns (30 min each pattern) from them. We assessed myelin integrity by measuring its periodicity and relative amount. Fixation of tissue itself introduced ±10% variation in periodicity and ±40% variation in relative amount of myelin. For samples having the most native‐like periods, the relative amounts of myelin detected allowed distinctions to be made between normal and demyelinating segments, between motor and sensory tracts within the spinal cord, and between aged and young primate CNS. Different periodicities also allowed distinctions to be made between samples from spinal cord and nerve roots and between well‐fixed and poorly fixed samples. Our findings suggest that, in addition to evaluating the effectiveness of different fixatives, XRD could also be used as a robust and rapid technique for quantitating the relative amount of myelin among spinal cords and other CNS tissue samples from experimental models of de‐ and remyelination. © 2009 Wiley‐Liss, Inc.
Millennial‐scale precipitation changes over Central Africa during the late Quaternary and Holocene: evidence in sediments from the Gulf of Guinea
Authors: Itambi Achakie C. , von Dobeneck Tilo , Adegbie Adesina T.
Published: September 2009

We combine environmental magnetism, geochemical measurements and colour reflectance to study two late Quaternary sediment cores: GeoB 4905‐4 at 2° 30′ N off Cameroon and GeoB 4906‐3 at 0° 44′ N off Gabon. This area is suitable for investigating precipitation changes over Central and West Africa because of its potential to record input of aeolian and fluvial sediments. Three magnetozones representing low and high degree of alteration of the primary rock magnetic signals were identified. The magnetic signature is dominated by fine‐grained magnetite, while residual haematite prevails in the reduced intervals, showing increase in concentration and fine grain size at wet intervals. Our records also show millennial‐scale changes in climate during the last glacial and interglacial cycles. At the northern location, the past 5.5 ka are marked by high‐frequency oscillations of Ti and colour reflectance, which suggests aeolian input and hence aridity. The southern location remains under the influence of the Intertropical Convergence Zone and thus did not register aeolian signals. The millennial‐scale climatic signals indicate that drier and/or colder conditions persisted during the late Holocene and are synchronous with the 900 a climatic cycles observed in Northern Hemisphere ice core records. Copyright © 2009 John Wiley & Sons, Ltd.
Is X‐ray core scanning non‐destructive? Assessing the implications for optically stimulated luminescence (OSL) dating of sediments
Authors: Davids Femke , Roberts Helen M. , Duller Geoffrey A. T.
Published: September 2009

Optically stimulated luminescence (OSL) dating is widely used to date clastic deposits, including those collected by coring. X‐ray scanning of cores has become popular because of the rapidly acquired, high‐resolution information it gives about optical, radiographic and elemental variations. Additionally, X‐ray scanning is widely viewed as a non‐destructive method. However, such instruments use an intense X‐ray beam that irradiates the split core to enable both X‐radiographic and X‐ray fluorescence (XRF) analysis. This irradiation will influence the optically stimulated luminescence signal in the sediments. This study determines the radiation dose delivered to sediments in a core during an X‐ray scan, and assesses the implications for studies wishing to combine X‐ray scanning and OSL dating. Copyright © 2009 John Wiley & Sons, Ltd.
Complications of midline‐open tracheotomy in adults
Authors: Straetmans Jos , Schlöndorff Georg , Herzhoff Gabi , Windfuhr Jochen P. , Kremer Bernd
Published: September 2009

Objectives/Hypothesis:

Percutaneous tracheotomy is progressively replacing open tracheotomy as a consequence of promising results of comparative studies. However, this comparison has four considerable weaknesses: 1) selected indications (high‐risk patients excluded for percutaneous tracheotomy); 2) varying spectra of complications included in different studies; 3) varying operative settings (experienced surgeons exclusively, surgeons in training, or both); and 4) missing differentiation between different surgical techniques. Our study was performed to collect complete datasets of unselected patients who all underwent a tracheotomy in a uniform technique in an academic teaching hospital setting.

Methods:

Retrospective evaluation of all complications following 303 consecutive surgical tracheotomies (midline‐open technique) performed by different surgeons and surgeons in training at one academic institution. Complications were classified and compared to results in the literature.

Results:

Rates of 21.5% minor and 1.0% major complications and 0% tracheotomy‐related mortality were registered. The most prevalent complications were local wound infections (10.9%), intra‐ and postoperative hemorrhages (4.2%), and cartilage damage (1.7%). No significant difference was found for high‐risk patients and emergency tracheotomies.

Conclusions:

Our study demonstrates that open tracheotomy is a safe procedure, particularly if performed in high‐risk patients even by inexperienced surgeons. Therefore, we emphasize the advantages of the midline‐open tracheotomy in an academic teaching hospital setting. Laryngoscope, 2010
Botulinum toxin in the treatment of lingual movement disorders
Authors: Kasravi Neema , Jog Mandar S.
Published: September 2009

Lingual movement disorders are a rare but serious manifestation of neurologic disease, which have the potential to cause significant morbidity. Traditionally, these disorders were treated with pharmacotherapy achieving only limited results. Several case series have demonstrated the effectiveness of Botulinum toxin injection for the management of focal lingual movement disorders; however, apprehension persists regarding intralingual injections due to the risk of dysphagia. Here, we report seven patients with lingual movement disorders treated with intralingual Botox™ (Allergan product) injections via a novel superior approach into the genioglossus over a period of 3 to 72 months. All patients experienced a marked improvement in their abnormal tongue movements with no substantial bleeding or dysphagia. Lingual Botulinum toxin injection should be considered a safe and viable treatment option for a variety of disorders affecting the tongue. © 2009 Movement Disorder Society
Mirror movements in patients with essential tremor
Authors: Louis Elan D. , Rios Eileen , Henchcliffe Claire
Published: September 2009

Mirror movements (MM), which occur in age‐related neurodegenerative diseases such as Parkinson's disease (PD), have never been studied in essential tremor (ET). The objective of this work is to study the prevalence and clinical correlates of MM in ET cases and controls. In a clinical‐epidemiological study in New York, participants performed repetitive motor tasks; MM (hands and feet) were rated. MM occurred in 35/107 (32.7%) ET cases versus 23/97 (23.7%) controls (OR 1.56, P = 0.16). Total MM score was 2× higher in cases (3.9 ± 7.7 vs. 1.9 ± 3.9, P = 0.02). MM (hands) occurred in 16 (15.0%) cases versus 5 (5.2%) controls (OR 3.24, P = 0.03) and total hand MM score was three to four times higher in ET cases (1.4 ± 4.5 vs. 0.4 ± 2.0, P = 0.03). MMs were not correlated with age, tremor duration, or severity and were most severe in cases with rest tremor. Thus, it was concluded that MM occurred in 1/3 of ET cases. These results further expand the spectrum of nontremor, motor phenomenology seen in ET. Whether, as in PD, MMs in ET represent a failure of subcortical structures to support the cortical network involved with the initiation of unilateral motor activity, requires future neurophysiological investigation. © 2009 Movement Disorder Society
Levosulpiride‐induced movement disorders
Authors: Shin Hae‐Won , Kim Mi J. , Kim Jong S. , Lee Myoung C. , Chung Sun J.
Published: September 2009

Levosulpiride is a substituted benzamide that is widely used for the management of dyspepsia and emesis. However, little is known about levosulpiride‐induced movement disorders (LIM). The aim of this study was to investigate the clinical characteristics of patients with LIM. Among 132 consecutive patients who were diagnosed with drug‐induced movement disorders between January 2002 and March 2008, 91 patients with LIM were identified and their medical records reviewed. Seventy‐eight (85.7%) patients were aged more than 60 years. The most common LIM was parkinsonism (LIP) (n = 85, 93.4%), followed by tardive dyskinesia (n = 9, 9.9%) and isolated tremor (n = 3, 3.3%). Twenty‐one (24.7%) of the 85 patients with LIP were rated as Hoehn and Yahr stage III–V. The oro‐lingual area was the only body part that was involved by tardive dyskinesia. LIM persisted after withdrawal of levosulpiride in 48.1% of patients with LIP, 66.7% with dyskinesia, and none with isolated tremor. None of clinical and MRI features predicted the reversibility of LIP. Levosulpiride frequently causes drug‐induced movement disorders, presenting mainly with LIP followed by lower face dyskinesia. The symptoms are often severe, and irreversible even after the withdrawal of levosulpiride. Physicians should be cautious in using levosulpiride, especially in elderly patients. © 2009 Movement Disorder Society
Correlation of endorectal 2D JPRESS findings with pathological Gleason scores in prostate cancer patients
Authors: Nagarajan Rajakumar , Gomez Ana M. , Raman Steve S. , Margolis Daniel J. , McClure Tim , Thomas M. Albert
Published: September 2009

To determine the metabolite ratios of (Cho + Cr)/Cit and (Cho + Cr)/Spm in patients with two ranges of pathological Gleason scores, namely (3 + 4) and (4 + 3). By using the localized two‐dimensional (2D) J‐resolved spectroscopy (JPRESS) technique, the metabolites ratios can be calculated and correlated with prostate cancer aggressiveness. A total of 24 patients who underwent endorectal 2D JPRESS between April 2006 and July 2007 were included in this study. The 2D JPRESS voxel was localized predominantly in the peripheral zone suspected for malignancy based on pathology. Using the metabolites such as total choline (Cho), creatine (Cr), spermine (Spm) and citrate (Cit), the ratios (Cho + Cr)/Cit and (Cho + Cr)/Spm were calculated. In 14 prostate cancer patients who had a final pathologic Gleason scores of i) (3 + 4 = 7, n = 7) and ii) (4 + 3 = 7, n = 7), the metabolite ratios (mean ± SD) of (Cho + Cr)/Cit and (Cho + Cr)/Spm were calculated using the 2D JPRESS spectra as follows: i) (1.48 ± 0.83) and (1.59 ± 0.73); ii) (2.90 ± 0.94) and (2.71 ± 1.47), respectively. Higher percentage of aggressive disease correlates with higher metabolites ratio. Our pilot study suggests that 2D JPRESS can be reliably evaluated in a clinical setting using an endorectal coil. In addition to the citrate ratio, the spermine ratio also correlates with pathology based Gleason score. Copyright © 2009 John Wiley & Sons, Ltd.
Return mapping algorithms and consistent tangent operators in ferroelectroelasticity
Authors: Semenov Artem S. , Liskowsky Albrecht C. , Balke Herbert
Published: September 2009

Return mapping algorithms for a rather general class of phenomenological rate‐independent models for ferroelectroelastic materials are presented. The fully coupled thermodynamically consistent three‐dimensional constitutive model with two internal variables (remanent polarization vector and remanent strain tensor) proposed by C. M. Landis in 2002 is used for the simulation of electromechanical hysteresis effects in polycrystalline ferroelectric ceramics. Based on the operator splitting methodology, the return mapping algorithm employs the closest point projection scheme to obtain an efficient and robust integration of the constitutive model. The consistent tangent operator is obtained in closed form by linearizing the return mapping algorithm, and is found to be non‐symmetric in the general case due to the dependence of the switching criterion on internal variables. Conditions that provide the symmetry of the consistent tangent matrix are analyzed. The compactness and generality of the received relations are achieved by means of using the thermodynamically based compact notations combining mechanical and electrical values. Both the cases scalar potential finite element (FE) formulation (primary variables: strain and electric field) and vector potential FE formulation (primary variables: strain and electric displacement) are considered. The accuracy and robustness of the algorithms are assessed through numerical examples. Copyright © 2009 John Wiley & Sons, Ltd.