bluuebunny/crossref_metadata_2025_split huggingface dataset:
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

AbstractPoly(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

AbstractAn 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

AbstractA 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

AbstractApplications 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

AbstractCell 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

AbstractHIP/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

AbstractThis 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

AbstractEndocrine 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

AbstractMethylene 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

AbstractCumulating 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

AbstractWe 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

AbstractAlthough 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

AbstractThe 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

AbstractApplicants' 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.