bluuebunny/crossref_metadata_2025 huggingface dataset:
Microsensors for in vivo Measurement of Glutamate in Brain Tissue
Authors: Qin Si , Van der Zeyden Miranda , Oldenziel Weite  H. , Cremers Thomas I.F.H. , Westerink Ben  H.C.
Published: November 2008

Several immobilized enzyme-based electrochemical biosensors for glutamate detection have been developed over the last decade. In this review, we compare first and second generation sensors. Structures, working mechanisms, interference prevention, in vitro detection characteristics and in vivo performance are summarized here for those sensors that have successfully detected brain glutamate in vivo. In brief, first generation sensors have a simpler structure and are faster in glutamate detection. They also show a better sensitivity to glutamate during calibration in vitro. For second generation sensors, besides their less precise detection, their fabrication is difficult to reproduce, even with a semi-automatic dip-coater. Both generations of sensors can detect glutamate levels in vivo, but the reported basal levels are different. In general, second generation sensors detect higher basal levels of glutamate compared with the results obtained from first generation sensors. However, whether the detected glutamate is indeed from synaptic sources is an issue that needs further attention.
Determination of Dopamine in the Presence of Ascorbic Acid by Nafion and Single-Walled Carbon Nanotube Film Modified on Carbon Fiber Microelectrode
Authors: Jeong Haesang , Jeon Seungwon
Published: November 2008

Carbon fiber microelectrode (CFME) modified by Nafion and single-walled carbon nanotubes (SWNTs) was studied by voltammetric methods in phosphate buffer saline (PBS) solution at pH 7.4. The Nafion-SWNTs/CFME modified microelectrode exhibited strongly enhanced voltammetric sensitivity and selectivity towards dopamine (DA) determination in the presence of ascorbic acid (AA). Nafion-SWNTs film accelerated the electron transfer reaction of DA, but Nafion film as a negatively charged polymer restrained the electrochemical response of AA. Voltammetric techniques separated the anodic peaks of DA and AA, and the interference from AA was effectively excluded from DA determination. Linear calibration plots were obtained in the DA concentration range of 10 nM - 10 μM and the detection limit of the anodic current was determined to be 5 nM at a signal-to-noise ratio of 3. The study results demonstrate that DA can be determined without any interference from AA at the modified microelectrode, thereby increasing the sensitivity, selectivity, and reproducibility and stability.
An improved branch‐and‐cut algorithm for mixed‐integer nonlinear systems optimization problem
Authors: Zhu Yushan , Hu Yijiong , Wu Hao , Nakaiwa Masaru
Published: November 2008

Recent advances for global optimization and dynamic optimization of the mixed‐integer systems have created an increasing demand for efficient and robust numerical algorithms for mixed‐integer nonlinear programming (MINLP) problem. In this article, an improved branch‐and‐cut algorithm for 0‐1 MINLP problems has been proposed by using our former critical finding (Zhu and Kuno, Ind Eng Chem Res. 2006;45:187–196) of the disjunctive cutting plane for 0‐1 MINLP. By virtue of the polyhedral outer approximation of the mixed‐integer nonlinear set of the original MINLP problem at each enumeration node, a lift‐and‐project cutting planes that is valid for the original MINLP problem and cuts the fractional solution away can be generated by using the cut generating, lifting, and strengthening approach for MILP problem of Balas et al. (Math Program. 1993;58:295–324). The specific implementation issues of the cutting planes are discussed and incorporated into the algorithmic development of a branch‐and‐cut algorithm. The efficiency of the improved disjunctive cutting plane is demonstrated by the computational results for 11 systems optimization problems, and it is implied that the proposed branch‐and‐cut algorithm is very promising for practical MINLP problems as the interior‐point solvers for nonlinear programming problems with many constraints are becoming mature gradually. © 2008 American Institute of Chemical Engineers AIChE J, 2008
Policy analysis of the ‘MPA‐process’ in temperate continental shelf areas
Authors: Rabaut Marijn , Degraer Steven , Schrijvers Jan , Derous Sofie , Bogaert Dirk , Maes Frank , Vincx Magda , Cliquet An
Published: November 2008

The decision to designate, implement and manage marine protected areas (MPAs) is often made ad hoc without clear guiding procedures. This study evaluates the process of establishment and management of MPAs in temperate soft‐bottom marine areas, including identification of objectives, site selection, designation, implementation, ecological effectiveness and socio‐economic impacts.

For the first time, literature about marine conservation strategies in soft‐bottom temperate areas is brought together in one ‘systems approach’, which is visualized in a flow chart including three phases: setting policy objectives, making decisions and evaluating the eventual effects of the MPA. Policy objectives are generally easy to identify and in most cases national policy objectives are driven by international and regional legal obligations. The decision making process is the most complex phase, as the acceptance of MPAs has to be balanced against the human activities that take place in the area.

The relation between fisheries and MPA‐management appears to be most challenging in soft‐bottom temperate marine areas because of conflicting interests and institutional differences. Activities limited in space and not relying directly on ecosystem functions (e.g. offshore energy production and aggregate extraction) are generally easier to manage than fisheries.

The conceptual mapping exercise presented here serves as a basis for a systems approach for MPAs and has been tested for the Belgian coastal environment. In the Belgian ‘MPA‐process’, the application of the systems approach proves to be useful in providing insight into the complex interactions of various authorities with scattered jurisdictions.

The unified and simplified representation of the various aspects is (1) a useful communication tool for policy makers and managers to inform other sectors and the public at large and (2) a valuable support during the ‘MPA‐process’ that considerably enhances the prospects for success.

Copyright © 2008 John Wiley & Sons, Ltd.
Skin disposition of menthol after its application in the presence of drug substances
Authors: Cal Krzysztof
Published: November 2008

Many drug products that are applied onto the skin contain menthol. Menthol plays a dual role in the analgesic and anti‐inflammatory drugs: it causes cooling and local anesthetic effects and, being a penetration enhancer, it increases the skin permeation of the drug substances. However, there are no data concerning the skin penetration of menthol after its application in the most commonly used vehicles and in the presence of drug substances. Therefore, this study evaluated the ex vivo skin disposition of menthol after application of the commercially available drug products containing aluminum acetotartrate, methyl salicylate, ibuprofen and naproxen, using full human‐skin mounted in flow‐through diffusion cells. After 15, 30 and 60 min of application, the skin was progressively tape‐stripped into three fractions of stratum corneum and the remaining epidermis with dermis. The content of menthol in the skin layers was determined by GC method. Varying degrees of penetration of menthol into the skin layers was observed, depending on its amount in the vehicle and the presence of drug substance. In the presence of aluminum acetotartrate, the skin penetration of menthol was limited only to the outer fraction of the stratum corneum. In the case of drug products containing naproxen, the concentration of the drug substance significantly influenced the skin penetration of menthol. Copyright © 2008 John Wiley & Sons, Ltd.
Fine‐grained record integration and linkage tool
Authors: Jurczyk Pawel , Lu James J. , Xiong Li , Cragan Janet D. , Correa Adolfo
Published: November 2008

BACKGROUND:As part of the surveillance program to monitor the occurrence of birth defects in the metropolitan Atlanta area, we developed a record linkage software tool that provides latitude in the choice of linkage parameters, allows for efficient and accurate linkages, and enables objective assessments of the quality of the linked data.METHODS:We developed and implemented a Java‐based fine‐grained probabilistic record integration and linkage tool (FRIL) that incorporates a rich collection of record distance metrics, search methods, and analysis tools. Along its workflow, FRIL provides a rich set of user‐tunable parameters augmented with graphic visualization tools to assist users in understanding the effects of parameter choices. We used this software tool to link data from vital records (n= 1.25 million) with birth defects surveillance records (n= 12,700) from the metropolitan Atlanta Congenital Defects Program (MACDP) for the birth years 1967–2006.RESULTS:Compared with the data linkage performed by conventional algorithms, the data linkage of birth certificates with birth defect records in MACDP using FRIL was more efficient. The linkage based on FRIL was also accurate, showing 99% precision and 95% recall. Based on positive user feedback, new features continue to be developed, and the tool is being adopted in several other data linkage projects in MACDP.CONCLUSIONS:A software tool that allows significant user interaction and control, such as FRIL, can provide accurate data linkages for birth defect surveillance programs and allows an objective assessment of the quality of linked data. Birth Defects Research (Part A), 2008. © 2008 Wiley‐Liss, Inc.
Elucidation of Oxygenation Steps during Oviedomycin Biosynthesis and Generation of Derivatives with Increased Antitumor Activity
Authors: Lombó Felipe , Abdelfattah Mohamed S. , Braña Alfredo F. , Salas José A. , Rohr Jürgen , Méndez Carmen
Published: November 2008

Eight different angucyclinones have been produced in Streptomyces albus by combining three oxygenase genes together with the polyketide synthase and cyclases genes from the oviedomycin biosynthetic gene cluster from Streptomyces antibioticus ATCC 11891. Four of these compounds were fully characterized for the first time. Three of these angucyclinones—prejadomycin‐2‐carboxylate (2), 4a,12b‐dehydro‐UWM6 (5), and prejadomycin (3)—show a significant increase in their in vitro antitumor activity relative to oviedomycin (1). A hypothesis for the sequence of tailoring events catalyzed by these three oxygenases during oviedomycin biosynthesis is proposed. In this hypothesis OvmOII acts as a bifunctional oxygenase/dehydratase.
The link between sufficient conditions by Harshman and by Kruskal for uniqueness in Candecomp/Parafac
Authors: Ten Berge Jos M. F. , Tendeiro Jorge N.
Published: November 2008

Harshman (UCLA Working Papers in Phonetics 1972; 22: 111–117) has given a proof of uniqueness (identification) of Parafac solutions, when two of the three component matrices are of full column rank, and the third satisfies a few other conditions. Kruskal has given more relaxed sufficient conditions, which do not require any of the component matrices to be of full column rank. However, even when two component matrices are of full column rank, Harshman's conditions on the third matrix are still less easily satisfied than Kruskal's. The present paper bridges the gap between the two sets of conditions by utilizing the possibilities of slice mixing in Harshman's approach. It offers an alternative uniqueness theorem that is sufficiently general for all practical purposes and easy to interpret, with a proof that is easy to understand. Copyright © 2008 John Wiley & Sons, Ltd.
Application of kinetic resolution using HCS as chiral auxiliary: Novel synthesis of β‐blockers (S)‐betaxolol and (S)‐metoprolol
Authors: Zhang Jing‐Yu , Liu Hong‐Min , Wang Xiao‐Jun , Wang Pei , Zheng Jia‐Xin
Published: November 2008

Optically pure (S)‐betaxolol and (S)‐metoprolol were prepared with an extremely facile and practical method using kinetic resolution of β‐amino alcohols employing HCS as chiral auxiliary. High enantiomeric purity (ee > 99%) was achieved and the synthetic strategy is amenable to industrial scale‐up. Chirality, 2009. © 2008 Wiley‐Liss, Inc.
Hemisuccinate of 21‐Hydroxy‐6,19‐Epoxyprogesterone: A Tissue‐Specific Modulator of the Glucocorticoid Receptor
Authors: Álvarez Lautaro D. , Martí Marcelo A. , Veleiro Adriana S. , Misico Rosana I. , Estrin Darío A. , Pecci Adalí , Burton Gerardo
Published: November 2008

The introduction of a hemisuccinate group at the 21‐position of the passive antiglucocorticoid 21OH‐6,19OP leads to a compound (21HS‐6,19OP) with a notable activity profile toward the glucocorticoid receptor (GR). In contrast to the parent steroid, 21HS‐6,19OP behaves as a pure agonist of GR activity in direct transactivation assays. However, the apoptotic effects of 21HS‐6,19OP show that the effect depends on cell type: while 21HS‐6,19OP is a pure agonist in L929 mouse fibroblasts, in thymocytes 21HS‐6,19OP had significant antiglucocorticoid activity. This tissue‐specific activity makes 21HS‐6,19OP a novel selective GR modulator. To investigate the molecular basis of action of 21HS‐6,19OP, we carried out molecular dynamics simulations (6 ns) of the GR ligand binding domain (LBD) complexed with 21HS‐6,19OP. Our results indicate that the hemisuccinate moiety may play a key role in stabilizing the active conformation of the receptor dimerization interface, reverting the changes observed with the antagonist 21OH‐6,19OP. Other changes in regions of the GR related to cofactor recruitment (possibly tissue‐specific), could explain this particular activity profile.
Tumor recurrence and malignant progression of gangliogliomas
Authors: Majores Michael , von Lehe Marec , Fassunke Jana , Schramm Johannes , Becker Albert J. , Simon Matthias
Published: November 2008

BACKGROUND.

Most gangliogliomas (GGs) are benign tumors, but tumor recurrence and malignant progression are observed in some patients.

METHODS.

The authors analyzed their experience with 4 recurrent/progressive GGs (World Health Organization [WHO] grade I), 21 tumors with atypical features (WHO grade II), and 5 tumors with anaplastic histologic features (WHO grade III). Histopathologic findings (23 patients) were reviewed. The mean follow‐up was 5.9 years (median, 4.5 years; range, 0.5‐14.7 years).

RESULTS.

The 5‐year survival rates were only 79% for patients who had tumors with atypical features and 53% for patients who had WHO grade III tumors. Secondary glioblastomas were diagnosed in 5 of 11 patients (45%) who underwent surgery for tumor recurrence. Age at surgery <40 years (P = .007) was associated significantly with better overall survival (OS), but it was not associated with better progression‐free survival (PFS). Clinical presentation (drug‐resistant epilepsy vs all other patients with seizures vs no seizures) was associated significantly with better OS (P = .005) and PFS (P < .001). Patients who had extratemporal tumors had a significantly shorter PFS (P = .01) but not OS. A complete resection was correlated strongly with both OS (P = .002) and PFS (P = .001). Neuropathologic examination revealed the presence of a gemistocytic cell component (PFS, P = .025), a lack of protein droplets (OS, P = .04; PFS, P = .05), and focal tumor cell‐associated CD34 immunolabeling (OS, P = .03) as significant predictors of an adverse clinical course.

CONCLUSIONS.

The current data supported a 3‐tiered GG histopathologic grading system that included an intermediate diagnostic category (atypical GG, WHO grade II). Careful attention to histopathologic findings and clinical parameters usually will identify patients who are at risk for an adverse clinical course. Cancer 2008. © 2008 American Cancer Society.
Prenatal behavior of the C57BL/6J mouse: A promising model for human fetal movement during early to mid‐gestation
Authors: Kleven Gale A. , Ronca April E.
Published: November 2008

The study of fetal neurobehavioral development in genetically altered mice promises a significant advance in our understanding of the prenatal origins of developmental disabilities in humans. Despite their importance, little is known about fetal neurobehavioral development in mice. In this study, we observed prenatal behavioral patterns of the C57BL/6J mouse, a common background strain for genetically altered mice, and report their similarity to those observed in the early to mid‐gestation human fetus. Fetal offspring from pregnant C57BL/6J dams were observed on the day before birth (E18 of a 19‐day gestation). Scoring and analysis of fetal movement included Prechtl's Method for Qualitative Assessment, Interlimb Movement Synchrony, a measure of the temporal relationship between movements of limb pairs, and Behavioral State, quantified through detailed analysis of high and low amplitude limb movements. With the exception of fetal breathing movements, all categories and patterns of behavior typically reported in the early to mid‐gestation human fetus were observed in the C57BL/6J mouse fetus. Our results suggest that behavioral analysis of fetal C57BL/6J mice may yield important new insights into early to mid‐gestation human behavioral development. © 2008 Wiley Periodicals, Inc. Dev Psychobiol 51: 84–94, 2009
Electrochemical Biosensing for Cancer Cells Based on TiO2/CNT Nanocomposites Modified Electrodes
Authors: Shen Qin , You Sun‐Kyung , Park Soo‐Gil , Jiang Hui , Guo Dadong , Chen Baoan , Wang Xuemei
Published: November 2008

Both TiO2 nanoparticles and carbon nanotubes have been usually utilized to modify the electrodes to enhance the detection sensitivity of biomolecular recognition. In this research, novel TiO2/CNT nanocomposites have been prepared and doped on the carbon paper as the modified electrodes. Subsequently, the redox behavior of the ferricyanide probe and the surface properties of the cancer cells coated on the modified electrodes have been investigated by using electrochemical and contact angle measurements. Compared with electrochemical signals on bare carbon paper and nanocomposite modified substrates, the significantly enhanced electrochemical signals on the modified electrodes covered with cancer cells have been observed. Meanwhile, different leukemia cells (i.e., K562/ADM cells and K562/B.W. cells) could be also recognized because of their different electrochemical behavior and hydrophilic/hydrophobic features on the modified electrodes due to the specific components on the plasma membranes of the target cells. This new strategy may have potential application in the development of the biocompatible and multi‐signal responsive biosensors for the early diagnosis of cancers.
Galvanostatic Entrapment of Sulfite Oxidase into Ultrathin Polypyrrole Films for Improved Amperometric Biosensing of Sulfite
Authors: Ameer Qaisar , Adeloju Samuel B.
Published: November 2008

The entrapment of sulfite oxidase (SOx) into ultrathin polypyrrole (PPy) films of 27–135 nm thickness has been successfully used for amperometric biosensing of sulfite with considerably improved performance. Optimum galvanostatic entrapment was accomplished in an electrolyte‐free solution which contained 0.1 M pyrrole and 5 U/mL of SOx with a polymerization period of 120 seconds and an applied current density of 0.2 mA cm−2. Evidence of the incorporation and retention of SOx in the ultrathin PPy film was obtained by scanning electron microscopy, cyclic voltammetry and amperometric measurements. Entrapment of the enzyme in a 54 nm thick PPy‐SOx film gave optimum amperometric response for sulfite and enabled the detection of as little as 0.9 μM of sulfite with a linear concentration range of 0.9 to 400 μM. The successful application of the biosensor to the determination of sulfite in beer and wine samples is reported. Comparison with a spectrophotometric method indicates that the biosensor was more superior for the determination of sulfite in red wine.
Overexpression of HMGA2 in uterine leiomyomas points to its general role for the pathogenesis of the disease
Authors: Klemke Markus , Meyer Anke , Nezhad Maliheh Hashemi , Bartnitzke Sabine , Drieschner Norbert , Frantzen Christiane , Schmidt Ernst Heinrich , Belge Gazanfer , Bullerdiek Jörn
Published: November 2008

An overexpression of HMGA2 is supposed to be a key event in the genesis of leiomyoma with chromosomal rearrangements affecting the region 12q14‐15 targeting the HMGA2 gene, but gene expression data regarding differences between uterine leiomyomas with and those without 12q14‐15 aberrations are insufficient. To address the question whether HMGA2 is only upregulated in the 12q14‐15 subgroup, the expression of HMGA2 was analyzed in a comprehensive set of leiomyomas (n = 180) including tumors with 12q14‐15 chromosomal aberrations (n = 13) and matching myometrial tissues (n = 51) by quantitative RT‐PCR. The highest expression levels for HMGA2 were observed in tumors with rearrangements affecting the region 12q14‐15, but although HMGA2 is expressed at lower levels in leiomyomas without such aberrations, the comparison between the expression in myomas and matching myometrial tissues indicates a general upregulation of HMGA2 regardless of the presence or absence of such chromosomal abnormalities. The significant (P < 0.05) overexpression of HMGA2 also in the group of fibroids without chromosomal aberrations of the 12q14‐15 region suggests a general role of HMGA2 in the development of the disease. © 2008 Wiley‐Liss, Inc.
Phytoglycoprotein (150 kDa) isolated fromSolanum nigrumLinne has a preventive effect on dextran sodium sulfate‐induced colitis in A/J mouse
Authors: Joo Heon‐Yeong , Lim Kwang , Lim Kye‐Taek
Published: November 2008

The purpose of this study was to investigate the preventive effect of glycoprotein (SNL glycoprotein, 150 kDa) isolated fromSolanum nigrumLinne fruits on dextran sulfate sodium (DSS, 3%)‐induced colitis in A/J mice. To determine the physiological change by SNL glycoprotein, we first evaluated nitric oxide production, lactate dehydrogenase release and thiobarbituric acid reactive substances formation in the mice serum. After that, we tested the activity of inflammation‐related signals such as transcriptional factor [nuclear factor‐kappa B (NF‐κB) and activator protein‐1 (AP‐1)], inducible nitric oxide synthase (iNOS) and cyclooxygenase‐2 (COX‐2) in the mice colon tissues. Our results showed that SNL glycoprotein has a dose‐dependent inhibitory effect on nitric oxide production, lactate dehydrogenase release, and thiobarbituric acid reactive substances formation. In the inflammation‐related signal, our finding showed that SNL glycoprotein (20 mg kg−1) has a suppressive effect on activities of NF‐κB (p50) and AP‐1 (c‐Jun), and regulates the expression of iNOS and COX‐2 in the downstream of signal pathway. Taken together, the results in this study indicated that SNL glycoprotein has potential for prevention of colitis caused by DSS in A/J mice. Copyright © 2008 John Wiley & Sons, Ltd.
Influence of poly(D,L‐lactic‐co‐glycolic acid) microsphere degradation on arteriolar remodeling in the mouse dorsal skinfold window chamber
Authors: Nickerson Meghan M. , Song Ji , Shuptrine Casey W. , Wieghaus Kristen A. , Botchwey Edward A. , Price Richard J.
Published: November 2008

Poly(D,L‐lactic‐co‐glycolic acid) (PLGA) is a biodegradable polymer that is widely used for drug delivery. However, the degradation of PLGA alters the local microenvironment and may influence tissue structure and/or function. Here, we studied whether PLGA degradation affects the structure of the arteriolar microcirculation through arteriogenic expansion of maximum lumenal diameters and/or the formation of new smooth muscle‐coated vessels. Single microspheres comprised of 50:50 PLGA (521 ± 52.7 μm diameter), 50:50 PLGA with bovine serum albumin (BSA) (547 ± 62.2 μm), 85:15 PLGA (474 ± 52.6 μm), or 85:15 PLGA with BSA (469 ± 57.2 μm) were implanted into mouse dorsal skinfold window chambers, and longitudinal arteriolar diameter measurements were made in the presence of a vasodilator (10−4M adenosine) over 7 days. At the end of the 7‐day period, the length density of all smooth muscle‐coated microvessels was also determined. Implantation of the window chamber alone elicited a 22% increase in maximum arteriolar diameter. However, the addition of 85:15 and 50:50 PLGA microspheres, bearing either BSA or no protein, elicited a significant enhancement of this arteriogenic response, with final maximum arteriolar diameters ranging from 36 to 46% more than their original size. Interestingly, the influence of PLGA degradation on microvascular structure was limited to lumenal arteriolar expansion, as we observed no significant differences in length density of smooth muscle‐coated microvessels. We conclude that the degradation of PLGA microspheres may elicit an arteriogenic response in subcutanteous tissue in the dorsal skinfold window chamber; however, it has no apparent effect on the total length of smooth muscle‐coated microvasculature. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Electrospun polyacrylonitrile nanofibrous biomaterials
Authors: Ren Xuehong , Akdag Akin , Zhu Changyun , Kou Lei , Worley S. D. , Huang T. S.
Published: November 2008

An N‐halamine precursor, 3‐(5′‐methyl‐5′‐hydantoinyl)acetanilide (I), was synthesized in our laboratory and loaded onto electrospun polyacrylonitrile fiber to prepare nanosized biocidal materials, which could be rendered antimicrobial by exposure to household bleach. Differential scanning calorimetry was used to study the thermal properties of the nanofibers with and without the N‐halamine precursor and its chlorinated derivative loaded. Scanning electron microscopy demonstrated that the ultrafine fibers formed with diameters from 250 to 600 nm. Chlorinated nanofibrous mats composed of the fibers were challenged with Staphylococcus aureus (ATCC 6538) and Escherichia coli O157:H7 (ATCC 43895); they showed promising inactivation efficacies against the two bacterial species within 5 minutes of contact. Potential uses of the antimicrobial fibers include filters for industrial water and air disinfection and protective clothing. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Hydrophilized polycaprolactone nanofiber mesh‐embedded poly(glycolic‐co‐lactic acid) membrane for effective guided bone regeneration
Authors: Cho Wan Jin , Kim Jun Ho , Oh Se Heang , Nam Hyun Hee , Kim Jin Man , Lee Jin Ho
Published: November 2008

A novel guided bone regeneration (GBR) membrane was fabricated by an immersion precipitation of poly (glycolic‐co‐lactic acid) (PLGA)/Pluronic F127 solution impregnated in an electrospun polycaprolactone (PCL)/Tween 80 nanofiber mesh. The prepared PCL/Tween 80 nanofiber mesh‐embedded PLGA/Pluronic F127 membrane (hydrophilized PCL/PLGA hybrid membrane) had nano‐size pores on the top side (which can prevent from fibrous connective tissue infiltration but allow permeation of oxygen and nutrients) and micro‐size pores on the bottom side (which can improve adhesiveness with bone). From the comparisons of mechanical properties (tensile and suture pullout strengths), model nutrient (FITC‐labeled bovine serum albumin) permeability, and bone regeneration behavior using a rat model (skull bone defect) of the hybrid membrane with those of PLGA/Pluronic F127 membrane (asymmetrically porous, hydrophilized PLGA membrane), PCL/Tween 80 nanofiber mesh (electrospun, hydrophilized PCL nanofiber mesh), and a commercialized GBR membrane, Bio‐Gide® (collagen type I/III membrane), it was observed that the PCL/PLGA hybrid membrane seems to be highly desirable as a GBR membrane for the selective permeability caused by its unique morphology and osteoconductivity provided by several tens micro‐size pores of the bottom side as well as the excellent mechanical strengths by the hybridization of porous PLGA membrane and PCL nanofiber mesh. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Tissue‐engineered polyethylene oxide/chitosan scaffolds as potential substitutes for articular cartilage
Authors: Kuo Yung‐Chih , Hsu Ya‐Ru
Published: November 2008

Applications of composite scaffolds comprising polyethylene oxide (PEO) and chitosan to the culture of bovine knee chondrocytes (BKC) were investigated. Here, PEO and chitosan with various weight ratios were crosslinked, refrigerated at −80°C, and lyophilized. Pore surfaces of the PEO/chitosan scaffolds were chemically modified by human fibronectin for accelerating BKC adhesion and growth. The results revealed that the range of pore diameters was between 200 and 400 μm. A high content of PEO in scaffolds generated high porosity, moisture content, physical ductility, biodegradation rate, and BKC viability, as well as low Young's and compression moduli. High levels of PEO, human fibronectin, and extracellular calcium were favorable to the BKC culture, as indicated by the enhanced amounts of BKC, glycosaminoglycans, and collagen. However, a high concentration of medium potassium caused detrimental influences on the proliferation of BKC and the secretion of extracellular matrices. The present PEO/chitosan scaffolds showed enhancements in biomedical characteristics for the formation of tissue‐engineered cartilage toward clinical prosthesis. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Titanium crystal orientation as a tool for the improved and regulated cell attachment
Authors: Faghihi Shahab , Azari Fereshteh , Szpunar Jerzy A. , Vali Hojatollah , Tabrizian Maryam
Published: November 2008

Cell adhesion is a fundamental process that controls cell proliferation, migration, and differentiation and is crucial for biomaterial‐tissue integration. Osteoblast attachment on the surfaces of implant materials is, therefore, essential for the proper function of any implant in which osseointegration is required. Although many reports are available on osteoblast attachment using different surface modification, there is no specific report, so far, that investigates the effect of atomic order of specific crystallographic orientation of substrates on cell behavior. A novel coculture system is proposed to show the differential response of preosteoblast and fibroblast cell lines to the titanium single‐crystal substrates. Our investigation has shown that surface recognition by the cell is influenced by the atomic structure of the surface leading to cell‐type‐specific adhesion. The degree of preosteoblast attachment is significantly higher on the Ti‐(1120), whereas the fibroblast adhesion is increased on the Ti‐(1010). This demonstrates that the three distinct faces of titanium substrates differ greatly in their capacity to serve as cell adhesive substrates. It also provides clear evidence for the role of crystal structure in regulating and improving cell–substrate interactions relevant for the optimal function of bone implant materials. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
HIP/RPL29 antagonizes VEGF and FGF2 stimulated angiogenesis by interfering with HS‐dependent responses
Authors: D'Souza Sonia , Yang Weidong , Marchetti Dario , Muir Caroline , Farach‐Carson Mary C. , Carson Daniel D.
Published: November 2008

HIP/RPL29 is a heparan sulfate (HS) binding protein with diverse activities including modulation of heparanase (HPSE) activity. We examined HIP/RPL29's ability to modulate actions of HS‐binding growth factors (HBGFs) in angiogenesis. Between 1 and 2.5 µg/ml (ca. 60–150 nM), HIP/RPL29 inhibited HBGF‐stimulated endothelial cell tube formation. Aortic explant outgrowth also was inhibited, but at higher concentrations (40 µg/ml). At this concentration, HIP/RPL29 had no effect on HBGF‐stimulated MAPK phosphorylation or VEGF‐stimulated receptor‐2 phosphorylation at site Y‐996. Partial inhibition occurred at VEGF receptor‐2 site Y951, associated with cell migration. HBGF displacement from HS‐bearing perlecan domain I showed that HIP/RPL29 released 50% of bound HBGF at 20 µg/ml, a dose where endothelial tube formation is inhibited. Similar FGF2 release occurred at pH 5.0 and 7.0, conditions where HPSE is highly and residually active, respectively. We considered that HIP/RPL29 inhibits HPSE‐dependent release of HS‐bound HBGFs. At pH 5.0, release of soluble HS was inhibited by 64% at concentrations of 5 µg/ml and by 77% at 40 µg/ml, indicating that HIP/RPL29 antagonizes HPSE activity. At concentrations up to 40 µg/ml (ca. 2.5 µM) where angiogenic processes are inhibited, release of FGF2 occurred in the presence of HPSE and HIP/RPL29. The majority of this FGF2 is not bound to soluble HS. Studies of HIP/RPL29 binding to HS indicated that many structural features of HS are important in modulation of HBGF activities. Our findings suggest that inhibition of angiogenic processes by HIP/RPL29 involves attenuation of the formation of soluble, biologically active HBGF:HS complexes that activate HBGF receptors. J. Cell. Biochem. 105: 1183–1193, 2008. © 2008 Wiley‐Liss, Inc.
L‐leucine increases [3H]‐thymidine incorporation in chicken hepatocytes: Involvement of the PKC, PI3K/Akt, ERK1/2, and mTOR signaling pathways
Authors: Lee Min Young , Jo Sung Duk , Lee Jang Hern , Han Ho Jae
Published: November 2008

This study examined how L‐leucine affected DNA synthesis and cell cycle regulatory protein expression in cultured primary chicken hepatocytes. L‐Leucine promoted DNA synthesis in a dose‐ and time‐dependent manner, with concomitant increases in cyclin D1 and cyclin E expression. Phospholipase C (PLC) and protein kinase C (PKC) mediated the L‐leucine‐induced increases in [3H]‐thymidine incorporation and cyclin D1/CDK4 and cyclin E/CDK2 expression, as U73122 (a PLC inhibitor) or bisindolylmaleimide I (a PKC blocker) inhibited these effects. L‐Leucine also increased PKC phosphorylation and intracellular Ca2+ levels. L‐Leucine‐mediated increases in [3H]‐thymidine incorporation and cyclin/CDK expression were sensitive to LY 294002 (PI3K inhibitor), Akt inhibitor, PD 98059 (MEK inhibitor). It was also observed that L‐leucine‐induced increases of cyclin/CDK expression were inhibited by PI3K siRNA and ERK siRNA; L‐leucine increased extracellular signal‐regulated kinases 1/2 (ERK1/2) and Akt phosphorylation levels. Bisindolylmaleimide I attenuated L‐leucine‐induced phosphorylation of ERK1/2 but did not influence Akt phosphorylation, and PI3K siRNA and LY 294002 inhibited L‐leucine‐induced ERK1/2 phosphorylation, suggesting some cross‐talk between the PKC and ERK1/2 or PI3K/Akt and ERK1/2 pathways. L‐Leucine also increased the levels of phosphorylated molecular target of rapamycin (mTOR) and two of its targets, ribosomal protein S6 kinase (p70S6K), and 4E binding protein 1 (4E‐BP1); furthermore, rapamycin (an mTOR inhibitor) blocked all of the mitogenic effects of L‐leucine. In addition, Akt inhibitor blocked L‐leucine‐induced mTOR phosphorylation. In conclusion, L‐leucine stimulated DNA synthesis and promoted cell cycle progression in primary cultured chicken hepatocytes through PKC, ERK1/2, PI3K/Akt, and mTOR. J. Cell. Biochem. 105: 1410–1419, 2008. © 2008 Wiley‐Liss, Inc.
Establishment of a transgenic yeast screening system for estrogenicity and identification of the anti‐estrogenic activity of malachite green
Authors: Jiao Baowei , Yeung Eric K.C. , Chan Chi Bun , Cheng Christopher H.K.
Published: November 2008

Endocrine disruptors refer to chemical compounds in the environment which interfere with the endocrine systems of organisms. Among them, environmental estrogens pose serious problems to aquatic organisms, in particular fish. It is therefore important and necessary to have a fast and low‐cost system to screen the large number of different chemical compounds in the aquatic environment for their potential endocrine disrupting actions. In this study, a screening platform was developed to detect xenoestrogens in the aquatic environment using the fission yeastSchizosaccharomyces pombe, and applied for compound screening. The aim was to demonstrate any significant potential differences between the fish screening system and the human screening system. To this end, a yeast expression vector harboring a fish estrogen receptor α and a reporter vector containing the estrogen responsive element fused with theEscherichia coli LacZgene were constructed. After transformation with these two vectors, the transformed yeast clones were confirmed by Western blotting and selected on the basis of the β‐galactosidase activity. In this transgenic yeast system, the natural estrogen (estradiol) and other known xenoestrogens such as diethylstilbestrol, bisphenol A, genistein and dichloro‐diphenyl‐trichloroethane exhibited dose‐dependent activities. Using this system, more than 40 putative endocrine disruptors including phytoestrogens, pesticides, herbicides, industrial dyes and other industrial chemicals were screened. Ten of them were demonstrated to exhibit estrogenic actions. Industrial dyes such as malachite green (MG) that disrupt thyroid hormone synthesis are extensively used and are widely distributed in the aquatic environment. Using this system, MG did not show any estrogenic action, but was demonstrated to exhibit anti‐estrogenic activity. J. Cell. Biochem. 105: 1399–1409, 2008. © 2008 Wiley‐Liss, Inc.
Methylene blue‐mediated photodynamic therapy induces mitochondria‐dependent apoptosis in HeLa Cell
Authors: Lu Yan , Jiao Ruiqing , Chen Xiaoping , Zhong Jieying , Ji Jianguo , Shen Pingping
Published: November 2008

Methylene blue (MB), a widely studied reagent, is investigated in this work for its usage in photodynamic therapy (PDT). PDT has been proved to be highly effective in the treatment of different types of cancers. Previous studies showed MB has both high affinity for mitochondria and high photodynamic efficiency. To elucidate the effects of MB in PDT, we analyzed PDT‐induced apoptosis in HeLa cells by introducing different doses of MB into the culture media. Our data showed that MB‐mediated PDT triggered intense apoptotic cell death through a series of steps, beginning with photochemical generation of reactive oxygen species. The release of cytochrome c and activation of caspase‐3 indicated that MB‐PDT‐mediated apoptosis in HeLa cells was executed by the mitochondria‐dependent apoptotic pathway. Importantly, proteomic studies confirmed that expression levels of several mitochondrial proteins were altered in MB‐PDT‐induced apoptosis, including TRAP1, mitochondrial elongation factor Tu and peroxiredoxin 3 isoform b. Western blot data showed that phosphorylation of ERK1/2 and PKA were reduced in MB‐PDT treated cells, indicating several signal molecules participating in this apoptotic cascade. Moreover, MB‐PDT induced an increase in the strength of interaction between Bcl‐xL and dephosphorylated Bad. This led to loss of the pro‐survival function of Bcl‐xL and resulted in mitochondria‐mediated apoptosis. This study provides solid evidence of a strong induction by MB‐PDT of a mitochondria‐dependent apoptosis cascade in HeLa cells. J. Cell. Biochem. 105: 1451–1460, 2008. © 2008 Wiley‐Liss, Inc.
Effects of heat shock on the distribution and expression levels of nuclear proteins in HeLa S3 cells
Authors: Haddad Nisrine , Paulin‐Levasseur Micheline
Published: November 2008

Cumulating evidence has led to the idea that nuclear functions such as DNA replication, RNA transcription, RNA splicing and nucleocytoplasmic transport are facilitated by a proteinaceous architectural framework within the nuclear compartment and at the nuclear envelope. In the present study, we have used immunofluorescence microscopy and quantitative Western blotting to compare the distribution and expression levels of several nuclear proteins during the response of HeLa S3 cells to both mild and severe hyperthermia. Cells were exposed to mild (42°C) or severe (45°C) hyperthermia treatment for 90 min and left to recover at 37°C for 1–25 h. The cell response was monitored immediately after the heat stress and at different time intervals during the recovery period. Our observations indicate that inner nuclear membrane proteins, LAP2β and emerin, as well as major components of the nuclear lamina, lamins A/C and lamin B1, maintain an overall normal distribution at the nuclear periphery throughout the cell response to mild or severe hyperthermia. The response was nevertheless characterized by significant changes in the expression levels of emerin following recovery from a mild stress and of lamin B1 after recovery from a severe stress. Our results also provide evidence that the organization of functional domains within the nuclear interior such as nucleoli and splicing speckles differs between cells responding to a mild or a severe stress. Mild hyperthermia was accompanied by a significant decrease in the expression level of the nucleolar protein 2H12 whereas severe hyperthermia was characterized by a reduction in the expression of the nucleocytoplasmic shuttling protein 2A7. Our data underline the complexity of nuclear function/structure relationships and the needs for a better understanding of protein–protein interactions within the nuclear compartment. J. Cell. Biochem. 105: 1485–1500, 2008. © 2008 Wiley‐Liss, Inc.
Serine protease inhibitors N‐α‐tosyl‐L‐lysinyl‐chloromethylketone (TLCK) and N‐tosyl‐L‐phenylalaninyl‐chloromethylketone (TPCK) do not inhibit caspase‐3 and caspase‐7 processing in cells exposed to pro‐apoptotic inducing stimuli
Authors: Frydrych Ivo , Mlejnek Petr
Published: November 2008

We recently demonstrated that TLCK and TPCK could act as potent but nonspecific inhibitors of mature caspases [Frydrych and Mlejnek [2008] J Cell Biochem 103:1646–1656]. The question whether TLCK and TPCK inhibit simultaneously caspase activation and/or processing remained, however, open. In this article, we demonstrated that TPCK even enhanced caspase‐3 and caspase‐7 processing although it substantially inhibited caspase‐3 and caspase‐7 enzymatic (DEVDase) activity in HL‐60 cells exposed to various cell death inducing stimuli. Under the same conditions, TLCK had no effect or affected caspase‐3 and caspase‐7 processing marginally depending on cell treatment used. Importantly, TLCK substantially inhibited caspase‐3 and caspase‐7 enzymatic (DEVDase) activity irrespectively to the treatment used. Interestingly, treatment of cells with toxic concentrations of TPCK alone was accompanied by full caspase‐3 and ‐7 processing even if it induced necrosis. In contrast, treatment of cells with concentrations of TLCK that caused necrosis was accompanied by only partial caspase‐3 and caspase‐7 processing. Our results clearly indicated that TPCK and TLCK did not inhibit caspase‐3 and ‐7 enzymatic activity by prevention of their activation and/or processing. J. Cell. Biochem. 105: 1501–1506, 2008. © 2008 Wiley‐Liss, Inc.
Zinc chloride stimulates DNA synthesis of mouse embryonic stem cells: Involvement of PI3K/Akt, MAPKs, and mTOR
Authors: Ryu Jung Min , Lee Min Young , Yun Seung Pil , Han Ho Jae
Published: November 2008

Although zinc is one of the most important trace elements in the body, the mechanisms underlying zinc‐induced cell proliferation have yet to be unraveled. Thus, we investigated the effect of zinc chloride (ZnCl2) on mouse embryonic stem (ES) cell proliferation and related signaling pathways. ZnCl2 (40 µM) significantly increased [3H]‐thymidine incorporation after 12 h of treatment. At moderate concentrations (≥4 µM), ZnCl2 increased cell cycle regulatory protein levels, [3H]‐thymidine incorporation, and total cell numbers, but higher doses of ZnCl2 (≥200 µM) blocked this proliferative effect. ZnCl2 induced the phosphorylation of Akt, c‐Jun N‐terminal kinases/stress‐activated protein kinases (JNK/SAPK), p44/42 MAPKs, and mammalian target of rapamycin (mTOR) in a time‐dependent manner. Pretreatment of LY 294002 (a PI3K inhibitor, 10−6 M), wortmannin (a PI3K inhibitor, 10−7 M), or an Akt inhibitor (10−5 M), which inhibited the activation of JNK/SAPK and p44/42 MAPKs, blocked the ZnCl2‐induced expression of cyclins and cyclin‐dependent kinases (CDKs). Furthermore, pretreatment with PD 98059 (a p44/42 inhibitor, 10−5 M) or SP 600125 (a JNK inhibitor, 10−6 M) inhibited ZnCl2‐induced activation of mTOR, p70S6K, and 4E‐BP1. In addition, rapamycin (an mTOR inhibitor, 10−8 M) blocked the ZnCl2‐induced increase in [3H]‐thymidine incorporation and cell cycle regulatory protein expression. In conclusion, ZnCl2 stimulated ES cell proliferation through the PI3K/Akt, p44/42 MAPKs, JNK/SAPK, and mTOR signal pathways. J. Cell. Physiol. 218: 558–567, 2009. © 2008 Wiley‐Liss, Inc.
Life after the layoff: getting a job worth keeping
Authors: McKee‐Ryan Frances M. , Virick Meghna , Prussia Gregory E. , Harvey Jaron , Lilly Juliana D.
Published: November 2008

The competitive environment of business today makes corporate layoffs an organizational reality, and losing one's job can be a highly stressful experience. We propose and test a model that places objective underemployment and subjective underemployment in a causal sequence between organizational actions and employees' restoration of equilibrium by obtaining jobs worth keeping. We longitudinally examine relationships between layoff fairness, workers' stress symptoms and appraisal, and subsequent employment outcomes among 149 laid‐off technical employees over the course of one year. Structural equation model results support seven of nine hypothesized paths, and demonstrate discriminant validity between and mediational properties of objective and subjective underemployment. Findings also reveal the important role that employees' perceptions and subjective assessments play in successfully returning to pre‐job loss equilibrium following displacement. Copyright © 2008 John Wiley & Sons, Ltd.
Predicting applicants' job pursuit behavior from their selection expectations: the mediating role of the theory of planned behavior
Authors: Schreurs Bert , Derous Eva , Van Hooft Edwin A. J. , Proost Karin , De Witte Karel
Published: November 2008

Applicants' pretest expectations about the forthcoming selection procedure may serve as a key factor in applicants' decision‐making. The current study examined the validity of the theory of planned behavior (TPB) as an explanatory mechanism of the relationship between pretest selection expectations (warmth/respect, chance to demonstrate potential, difficulty of faking, unbiased assessment, feedback) and job pursuit behavior. Data were collected at two points in time, using a sample of applicants for the military. Selection expectations, job pursuit attitude, subjective norm, and controllability were significantly related to job pursuit intention. Job pursuit attitude mediated the relationship between selection expectations and job pursuit intention. Subjective norm and time lag were the only significant predictors of job pursuit behavior. Practical implications, strengths and limitations, as well as directions for further research are discussed. Copyright © 2008 John Wiley & Sons, Ltd.