bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dietary α‐, β‐, γ‐ and δ‐tocopherols in lung cancer risk
Authors: Mahabir Somdat , Schendel Kalli , Dong Yong Quan , Barrera Stephanie L. , Spitz Margaret R. , Forman Michele R. 
Published: June 2008

AbstractStudies of vitamin E and cancer have focused on the α‐tocopherol form of the vitamin. However, other forms of vitamin E, in particular γ‐tocopherol may have unique mechanistic characteristics relevant to lung cancer prevention. In an ongoing study of 1,088 incident lung cancer cases and 1,414 healthy matched controls, we studied the associations between 4 tocopherols (α‐, β‐, γ‐, and δ‐tocopherol) in the diet and lung cancer risk. Using multiple logistic regression analysis, the adjusted odds ratios (OR) and 95% confidence intervals (CI) of lung cancer for increasing quartiles of dietary α‐tocopherol intake were 1.0, 0.63 (0.50–0.79), 0.58 (0.44–0.76) and 0.39 (0.28–0.53), respectively (p‐trend < 0.0001). For dietary intake of β‐tocopherol, the OR and 95% CI for all subjects were: 1.0, 0.79 (0.63–0.98), 0.59 (0.45–0.78) and 0.56 (0.42–0.74), respectively (p‐trend < 0.0001). Similar results for dietary γ‐tocopherol intake were observed: 1.0, 0.84 (0.67–1.06), 0.76 (0.59–0.97) and 0.56 (0.42–0.75), respectively (p‐ trend = 0.0002). No significant association between δ‐tocopherol intake and lung cancer risk was detected. When the 4 tocopherols were summed as total tocopherol intake, a monotonic risk reduction was also observed. When we entered the other tocopherols in our model, only the association with dietary α‐tocopherol intake remained significant; i.e., increasing intake of dietary α‐tocopherol accounted for 34–53% reductions in lung cancer risk. To the best of our knowledge, this is the first report of the independent associations of the 4 forms of dietary tocopherol (α‐, β‐, γ‐ and δ‐tocohperol) on lung cancer risk. Given the limitations with case‐control studies, these findings need to be confirmed in further investigations. © 2008 Wiley‐Liss, Inc.
CpG island methylator phenotype association with upregulated telomerase activity in hepatocellular carcinoma
Authors: Zhang Changsong , Guo Xianling , Jiang Guocheng , Zhang Li , Yang Yang , Shen Feng , Wu Mengchao , Wei Lixin 
Published: June 2008

AbstractCpG island methylator phenotype (CIMP) involves the targeting of multiple genes by promoter hypermethylation. Telomerase plays an important role in the development of cellular immortality and oncogenesis. To gain insight into the role of epigenetic aberration of telomerase‐related genes in hepatocarcinogenesis, we determined a hypermethylation profile in HCC. We examined the promoter methylation status of 9 genes associated with telomerase activity in 120 HCC, 120 cirrhosis tissues and 10 normal liver tissues by methylation‐specific PCR. Assay of telomerase activity was by TRAP‐ELISA. The frequency of promoter methylation of each gene wasP2163.3%,P1542.5%,P1662.5%,P5314.2%,RB32.5%,P2748.3%,WTI54.2%,E2F‐170.8% andP30065.8% of 120 HCC. Methylation status ofP21,P15,P16, WTIandE2F‐1was significantly associated with HCC and nontumor tissues (p< 0.05). CIMP+ was detected in 61.7% (74/120) HCC and 15% (18/120) cirrhosis tissues, no CIMP+ was present in normal liver tissues (p< 0.001). A significant difference between CIMP status and metastasis was been found in HCC (p< 0.001). Results showed that 94.6% (70/74) HCC and 55.6% (10/18) cirrhosis patients with CIMP+ show expression of high telomerase activity than 45.5% (10/22) HCC and 6.25% (1/16) cirrhosis patients with CIMP− (p< 0.001). CIMP lead to high levels of expression of telomerase activity through the simultaneous inactivation of multiple genes associated with telomerase activity by concordant methylation. © 2008 Wiley‐Liss, Inc.
The Stream Inlet to a Shallow Bay of a Drinking Water Reservoir, a ‘Hot‐Spot’ forMicrocystisBlooms Initiation
Authors: Izydorczyk Katarzyna , Skowron Aleksandra , Wojtal Adrianna , Jurczak Tomasz 
Published: June 2008

AbstractStream inlets into shallow bays of reservoirs and lakes may be ‘hot‐spots’ for toxic cyanobacterial bloom initiation. These ‘hot‐spots’ may be connected with the permanent inflow of high nutrient concentrations from the catchment, optimal physical conditions (wind protected areas) that occur in shallow areas and/or ineffective top‐down control. Four sampling sites along a transect from stream to reservoir in a shallow bay of Sulejow Reservoir (Poland) were studied to test the above hypothesis, comprising a transition zone between lotic and pelagic habitats. Investigations showed that stream inlet into shallow bay acted as incubator forMicrocystisblooms. The nutrient level, especially phosphorus, was identified as the major cause of cyanobacterial bloom growth. The increase ofMicrocystisbiomass strongly correlated with increasing microcystin concentrations, however, a relationship with microcystin content was not observed. Toxicity of bloom demonstrated seasonal variability, reaching its maximum at the initial phase of bloom. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effects of Leaf Litter Species on Macroinvertebrate Colonization during Decomposition in a Portuguese Stream
Authors: Abelho Manuela 
Published: June 2008

AbstractThis study evaluated if there are differences in leaf breakdown and invertebrate colonization among tree species differing in quality (toughness), and which factors could influence these differences. Common alder leaves decomposed significantly faster then either sweet chestnut or Spanish oak (k values of –0.0332, –0.0108, and –0.0112, respectively) during the first 2 months. Shredder abundance was highest when leaf mass remaining was 50%, and the samples clustered in mixed groups of sampling dates and leaf species, suggesting that stage of decomposition was an important factor influencing shredder colonization. During the first two months of decomposition, the physicochemical characteristics of leaf litter and the interaction between leaf toughness and the occurrence of frequent spates seemed to be the main factors affecting leaf breakdown rates in the stream. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The spliced variant of hepatitis B virus protein, HBSP, interacts with Bcl‐2/Bcl‐xl in vitro and induces apoptosis in HepG2 cells
Authors: Lu Yi Wei , Ren Yu Dan , Bai Jing , Chen Wei Ning 
Published: June 2008

AbstractWe have recently reported that the naturally occurring spliced variant of Hepatitis B virus protein, HBSP, displayed proapoptotic activity through its BH3 domain. To investigate whether the BH3 domain in HBSP interacted with Bcl‐2 family of proteins, HBSP and Bcl‐2 family of proteins were cloned and expressed in our mammalian two‐hybrid system. Interaction assays were carried out in HepG2 cells and measured by the activity of the reporter gene product luciferase. Our results indicated that HBSP interacted with Bcl‐2/Bcl‐xl in vitro and induced apoptosis in HepG2 cells. © 2008 IUBMB IUBMB Life, 60(10): 700–702, 2008
Hydrophilic electrospun polyurethane nanofiber matrices for hMSC culture in a microfluidic cell chip
Authors: Lee Kwang Ho , Kwon Gu Han , Shin Su Jung , Baek Ju‐Yeoul , Han Dong Keun , Park Yongdoo , Lee Sang Hoon 
Published: June 2008

AbstractMimicking cellular microenvironments by MEMS technology is one of the emerging research areas. Integrated biomimetic systems with nanofiber polymer networks and microfluidic chips were fabricated and cellular behaviors were observed by changing surface characteristics of nanofibers and flow rates of microchannels. Modification of polyurethane nanofiber surfaces were achieved by grafting acrylic acid with plasma treatment and these nanofiber matrices were employed in a poly(dimethylsiloxane) based microfluidic chip. The surface characteristics of both electrospun nanofiber matrices was evaluated by measuring contact angle, porosity, and chemical structure using attenuated total reflection‐Fourier transform infrared spectrometry. After modification, a terminal carboxyl group formed on the nanofiber surface and the wettability increased significantly. Human MSCs were seeded on the nanofiber matrices and a morphological investigation with actin filament staining and scanning electron microscopy was performed. A proliferation test by WST‐1 and Live/Dead assay were performed to investigate the cell culture environment. It was observed that the cells on the AA‐grafted nanofibers spread and proliferate compared to untreated nanofibers. It has also shown that flow rates in the microchannels played an important role for cell proliferation (Sim et al., Lab Chip 2007;7:1775‐1782). Integration of nanofiber matrices into the microchannels provides the useful tools for mimicking cellular microenvironments and elucidating basic questions of cell and ECM assembly and interactions. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Elastomeric high‐mineral content hydrogel‐hydroxyapatite composites for orthopedic applications
Authors: Song Jie , Xu Jianwen , Filion Tera , Saiz Eduardo , Tomsia Antoni P. , Lian Jane B. , Stein Gary S. , Ayers David C. , Bertozzi Carolyn R. 
Published: June 2008

AbstractThe design of synthetic bone grafts that mimic the structure and composition of bone and possess good surgical handling characteristics remains a major challenge. We report the development of poly(2‐hydroxyethyl methacrylate) (pHEMA)‐hydroxyapatite (HA) composites termed “FlexBone” that possess osteoconductive mineral content approximating that of human bone yet exhibit elastomeric properties enabling the press‐fitting into a defect site. The approach involves crosslinking pHEMA hydrogel in the presence of HA using viscous ethylene glycol as a solvent. The composites exhibit excellent structural integration between the apatite mineral component and the hydroxylated hydrogel matrix. The stiffness of the composite and the ability to withstand compressive stress correlate with the microstructure and content of the mineral component. The incorporation of porous aggregates of HA nanocrystals rather than compact micrometer‐sized calcined HA effectively improved the resistance of the composite to crack propagation under compression. Freeze‐dried FlexBone containing 50 wt % porous HA nanocrystals could withstand hundreds‐of‐megapascals compressive stress and >80% compressive strain without exhibiting brittle fractures. Upon equilibration with water, FlexBone retained good structural integration and withstood repetitive moderate (megapascals) compressive stress at body temperature. When subcutaneously implanted in rats, FlexBone supported osteoblastic differentiation of the bone marrow stromal cells pre‐seeded on FlexBone. Taken together, the combination of high osteoconductive mineral content, excellent organic‐inorganic structural integration, elasticity, and the ability to support osteoblastic differentiation in vivo makes FlexBone a promising candidate for orthopedic applications. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Injection of a novel synthetic hydrogel preserves left ventricle function after myocardial infarction
Authors: Jiang Xue‐Jun , Wang Tao , Li Xiao‐Yan , Wu De‐Qun , Zheng Zhao‐Bin , Zhang Jin‐Feng , Chen Jin‐Ling , Peng Bin , Jiang Hong , Huang Congxin , Zhang Xian‐Zheng 
Published: June 2008

AbstractMyocardial infarction (MI) and the subsequent heart failure remain one of the leading causes of morbidity and mortality world wide. A number of studies have demonstrated that bioderived materials improve cardiac function after implantation because of their angiogenic potential. In this study, we hypothesized that injection of biomaterials into infarcted myocardium can preserve left ventricular (LV) function through its prevention of paradoxical systolic bulging. To test this hypothesis, infarction was induced in rabbit myocardium by coronary artery ligation. After 1 week, 200‐μL α‐cyclodextrin (α‐CD)/MPEG‐PCL‐MPEG hydrogel was injected into the infarcted myocardium. Injection of phosphate buffered saline (PBS) served as controls. Twenty‐eight days after the treatment, histological analysis indicated that the injection of hydrogel prevented scar expansion and wall thinning compared with the control (p < 0.05) without more microvessel density in infarcted myocardium (p = 0.70). LV ejection fraction, determined by echocardiography, was significantly greater in the hydrogel‐treated group (56.09% ± 8.42%) than the control group (37.26% ± 6.36%, p = 0.001). The LV end‐diastolic and end‐systolic diameters were 2.07 ± 0.33 cm and 1.74 ± 0.30 cm, respectively, in the control group. Smaller LV end‐diastolic diameter (1.61 ± 0.26 cm, p = 0.005) and smaller end‐systolic diameter (1.17 ± 0.23 cm, p = 0.001) were found in the hydrogel‐treated group. These results suggest that α‐CD/MPEG‐PCL‐MPEG hydrogel could serve as an injectable biomaterial that prevents LV remodeling and dilation for the treatment of MI. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Computer simulated screening of dentin bonding primer monomers through analysis of their chemical functions and their spatial 3D alignment
Authors: Vaidyanathan J. , Vaidyanathan T. K. , Ravichandran S. 
Published: June 2008

AbstractBinding interactions between dentin bonding primer monomers and dentinal collagen were studied by an analysis of their chemical functions and their spatial 3D alignment. A trial set of 12 monomers used as primers in dentin adhesives was characterized to assess them for binding to a complementary target. HipHop utility in the Catalyst software from Accelrys was used for the study. Ten hypotheses were generated by HipHop procedures involving (a) conformational generation using a poling technique to promote conformational variation, (b) extraction of functions to remodel ligands as function‐based structures, and (c) identification of common patterns of functional alignment displayed by low energy conformations. The hypotheses, designated as pharmacaphores, were also scored and ranked. Analysis of pharmacaphore models through mapping of ligands revealed important differences between ligands. Top‐ranked poses from direct docking simulations using type 1 collagen target were mapped in a rigid manner to the highest ranked pharmacophore model. The visual match observed in mapping and associated fit values suggest a strong correspondence between direct and indirect docking simulations. The results elegantly demonstrate that an indirect approach used to identify pharmacaphore models from adhesive ligands without a target may be a simple and viable approach to assess their intermolecular interactions with an intended target. Inexpensive indirect/direct virtual screening of hydrophilic monomer candidates may be a practical way to assess their initial promise for dentin primer use well before additional experimental evaluation of their priming/bonding efficacy. This is also of value in the search/design of new compounds for priming dentin. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009
Suitability of differently designed matrix‐based implant surface coatings: An animal study on bone formation
Authors: Stadlinger Bernd , Pilling Eckart , Huhle Matthias , Khavkin Evgenij , Bierbaum Susanne , Scharnweber Dieter , Kuhlisch Eberhard , Eckelt Uwe , Mai Ronald 
Published: June 2008

AbstractIntroduction: The aim of the present study was to assay how bone formation around dental implants is influenced by differently composed collagen matrices and RGD peptide as implant surface coatings compared to a sandblasted titanium surface. Material and Methods: Five different implant surface coatings were designed: titanium (sandblasted), collagen type I, collagen type I&III, RGD‐peptide, and mineralized collagen. Sixty experimental implants of a square‐shaped design were inserted into the mandibles of 12 minipigs, 3 months following extraction of the premolar teeth. During the 6‐month study period, sequential polyfluorochrome labeling was performed. After sacrifice, bone implant contact (BIC) was evaluated using histologic and histomorphometric methods. Results: New bone formation was observed against all implant surfaces. Polyfluorochrome labeling showed that bone growth started from the host bone in the majority of samples. The highest BIC was measured for collagen I and collagen I/III coated implants; however, significant differences between the coatings could not be found. Conclusion: Osseointegration was achieved for all implant surfaces. Although a statistically significant increase in BIC could not be demonstrated for the experimental coatings after the 6 months study period, there was also no discernible detrimental effect of the coatings in comparison to the uncoated titanium surfaces. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008
Investigation of the antiadhesive properties of human mesothelial cells cultured in vitro on implantable surgical materials
Authors: Wilshaw Stacy‐Paul , Burke Dermot , Fisher John , Ingham Eileen 
Published: June 2008

AbstractThe aim of the study was to evaluate the interactions of Permacol, Prolene mesh, Surgisis Gold, and Alloderm with human mesothelial cells in vitro. The capacity of primary human mesothelial cells to adhere to the surface of Alloderm, Surgisis Gold, Prolene mesh, and Permacol as well as support the proliferation and viability of the seeded cells was determined. Production of antifibrinolytic, fibrinolytic, and inflammatory mediators (IL‐8, TPA, MMP‐1, PAI‐1, and TGF‐β) was assessed over an 8‐day period. The adhesive nature of the implantable materials was determined by assessment of the strength of any fibrin clots formed between two surfaces of each implant material. Surgisis Gold and Permacol were capable of supporting the attachment and proliferation of primary human mesothelial cells and maintaining viability over an 8‐day culture period. Mesothelial cells were shown to have covered the surface of Permacol and Surgisis Gold in a monolayer. The viability of cells cultured on Permacol was significantly greater than the other implant materials tested. Mesothelial cells cultured on Permacol or Surgisis were shown to be producing high levels of fibrinolytic compounds and low levels of antifibrinolytic and inflammatory mediators. Alloderm was shown to produce high levels of IL‐8 and antifibrinolytic mediators when compared with the other implantable materials. Permacol was shown to be an unreliable surface for clot formation in vitro and any clots formed were shown to be significantly weaker than the clots produced between two surfaces of tissue culture plastic, Prolene mesh, Alloderm, and Surgisis Gold. This in vitro study indicated that Permacol and Surgisis Gold supported the growth and fibrinolytic activity of human mesothelial cells; however, Permacol was shown to be superior in this respect. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009
Evaluation of substrates for 90° peel adhesion—A collaborative study. II. Transdermal drug delivery systems
Authors: Wokovich Anna M. , Brown Stanley A. , Shen Meiyu , Doub William H. , Cai Bing , Sadrieh Nakissa , Chen Mei Ling , Machado Stella , Buhse Lucinda F. 
Published: June 2008

AbstractIn a previous study on peel adhesion for medical tapes, it was shown that a stainless steel (SS) substrate better discriminated among medical tapes than a high‐density polyethylene (HDPE) substrate. The objective of this study was to determine if a SS substrate would also better distinguish among transdermal drug delivery systems (TDDSs). Five TDDSs (Vivelle Dot®, Climara®, Catapres‐TTS®, Duragesic®, and Mylan Fentanyl) were evaluated on three different substrates (SS, HDPE, and human cadaver skin). All measurements were made using a dwell time of ∼3 min, a peel angle of 90°, and a peel speed of 300 mm/min. Differences among TDDSs were greater for SS than for HDPE, using the F statistic for testing for differences among TDDSs means as a measure of heterogeneity, thereby indicating greater discrimination by SS. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009
The mismatch repair‐mediated cell cycle checkpoint response to fluorodeoxyuridine
Authors: Liu Angen , Yoshioka Ken‐ichi , Salerno Vincenzo , Hsieh Peggy 
Published: June 2008

AbstractThe loss of DNA mismatch repair (MMR) is responsible for hereditary nonpolyposis colorectal cancer and a subset of sporadic tumors. Acquired resistance or tolerance to some anti‐cancer drugs occurs when MMR function is impaired. 5‐Fluorouracil (FU), an anti‐cancer drug used in the treatment of advanced colorectal and other cancers, and its metabolites are incorporated into RNA and DNA and inhibit thymidylate synthase resulting in depletion of dTTP and incorporation in DNA of uracil. Although the MMR deficiency has been implicated in tolerance to FU, the mechanism of cell killing remains unclear. Here, we examine the cellular response to fluorodeoxyuridine (FdU) and the role of the MMR system. After brief exposure of cells to low doses of FdU, MMR mediates DNA damage signaling during S‐phase and triggers arrest in G2/M in the first cell cycle in a manner requiring MutSα, MutLα, and DNA replication. Cell cycle arrest is mediated by ATR kinase and results in phosphorylation of Chk1 and SMC1. MutSα binds FdU:G mispairs in vitro consistent with its being a DNA damage sensor. Prolonged treatment with FdU results in an irreversible arrest in G2 that is independent of MMR status and leads to the accumulation of DNA lesions that are targeted by the base excision repair (BER) pathway. Thus, MMR can act as a direct sensor of FdU‐mediated DNA lesions eliciting cell cycle arrest via the ATR/Chk1 pathway. However, at higher levels of damage, other damage surveillance pathways such as BER also play important roles. J. Cell. Biochem. 105: 245–254, 2008. © 2008 Wiley‐Liss, Inc.
Increased hepatic UCP2 expression in rats with nonalcoholic steatohepatitis is associated with upregulation of Sp1 binding to its motif within the proximal promoter region
Authors: Jiang Ying , Zhang Hua , Dong Ling‐yue , Wang Dan , An Wei 
Published: June 2008

AbstractUncoupling protein‐2 (UCP2) is a mitochondrial inner‐membrane carrier protein that is involved in the control of fatty acid metabolism. To understand the mechanism of the transcriptional regulation ofucp2in the pathogenesis of nonalcoholic steatohepatitis (NASH), we cloned 500 bp upstream of theucp2exon 1 from a rat liver cDNA library and identifiedcis‐acting regulatory elements. The transcriptional start site was identified as “C,” −359 bp from the ATG codon. A reporter gene assay showed that deletion of the nucleotide sequence between −264 and −60 bp resulted in a significant decrease in promoter activity in HepG2 and H4IIE cells. Electrophoretic mobility shift assay (EMSA) and chromatin immunoprecipitation (ChIP) revealed that the increase in promoter activity is related to an enhanced ability of Sp1 to bind to its motifs at −84 to −61 bp within theucp2proximal promoter. Overexpression of exogenous Sp1 in H4IIE cells also increased the promoter activity. We demonstrated that the expression of UCP2 mRNA and protein is markedly increased in rats with nonalcoholic steatohepatitis (NASH). Coincidently, levels of Sp1 binding to −84/−61 bp were also increased. Overall, our data indicate that the Sp1‐binding site located at the proximal promoter is involved in the regulation of rat UCP2 expression. J. Cell. Biochem. 105: 277–289, 2008. © 2008 Wiley‐Liss, Inc.