bluuebunny/crossref_metadata_2025_split huggingface dataset:
Identification of genes differentially expressed in human hepatocellular carcinoma by a modified suppression subtractive hybridization method
Authors: Dong Xue‐Yuan , Pang Xue‐Wen , Yu Song‐Tao , Su Yan‐Rong , Wang Hong‐Chen , Yin Yan‐Hui , Wang Yue‐Dan , Chen Wei‐Feng 
Published: June 2004

AbstractTo identify differentially expressed genes in human HCC in China, we applied a modified SSH method for cDNA subtraction. Such modification has made the method more effective for subtraction. We have obtained 36 and 24 differentially expressed cDNA fragments after modified SSH from 4 paired samples of human HCC and non‐HCC tissues, respectively. Reverse Northern blotting analysis was performed to further identify the genes differentially expressed in the HCC and non‐HCC tissue samples. There were 25 genes really overexpressed in HCC, and their corresponding encoding molecules may reflect the events of cell accelerated metabolism, proliferation, angiogenesis, anti‐apoptosis, tumorigenesis (TLH107, TFH9) and the potential for metastasis. Of the 25 genes overexpressed in HCC, 5 were novel and their full‐length cDNAs were cloned. These 5 novel genes are functionally associated with the occurrence and development of HCC according to the Database analysis. In the paired non‐HCC tissues, there were 15 genes lowly or not expressed in HCC, and their encoding proteins function as tumor suppressors (TFA3, TFA11), acute‐phase reactive proteins, and the blood plasma proteins that are mainly or exclusively synthesized in the liver. The distinct profiles of the differentially expressed genes in HCC and the paired non‐HCC tissues have partially reflected the genetic alterations during HCC tumorigenesis. The novel HCC‐specific gene TLH6 and the CT antigen encoding gene TLH107 may have diagnostic and therapeutic potentials in HCC and/or other solid cancers. © 2004 Wiley‐Liss, Inc.
Carotenoids, vitamin A and risk of adenomatous polyp recurrence in the polyp prevention trial
Authors: Steck‐Scott Susan , Forman Michele R. , Sowell Anne , Borkowf Craig B. , Albert Paul S. , Slattery Martha , Brewer Brenda , Caan Bette , Paskett Electra , Iber Frank , Kikendall Walt , Marshall James , Shike Moshe , Weissfeld Joel , Snyder Kirk , Schatzkin Arthur , Lanza Elaine ,   The Polyp Prevention Trial Study Group
Published: June 2004

AbstractOne trial reported beta‐carotene supplementation was protective of adenomatous polyp recurrence in nonsmokers. We now examine the relation of serum and dietary carotenoids and vitamin A to adenomatous polyp recurrence in a subcohort of 834 participants in a low fat, high fiber, high fruit and vegetable dietary intervention, the Polyp Prevention Trial. Multivariate odds ratio (OR) and 95% confidence intervals (CI) of polyp recurrence were obtained using baseline or the average (first 3 years of the trial) carotenoid and vitamin A values after adjustment for covariates. Compared to the lowest quartile of baseline alpha‐carotene concentrations, the OR of multiple polyp recurrence for the highest quartile was 0.55 (95% CI = 0.30–0.99) and the OR of right‐sided recurrence was 0.60 (95% CI = 0.37–0.95). Baseline dietary intakes of alpha‐carotene and vitamin A from food with/without supplements were inversely associated with any recurrence (pfor linear trend = 0.03‐ alpha‐carotene; p = 0.004 and p = 0.007 ‐intakes of vitamin A). Compared to the lowest quartile of averaged beta‐carotene concentrations, the OR of multiple adenomas for the highest quartile was 0.40 (95% CI = 0.22–0.75) with an inverse trend (p = 0.02). The risk was inversely related to averaged: alpha‐carotene concentrations and right‐sided polyps; alpha‐carotene intake and recurrence of any, multiple and right‐sided polyps; beta‐carotene intake and multiple adenoma recurrence; vitamin A from food (with supplements) and each adverse endpoint. Thus, alpha‐carotene and vitamin A may protect against recurrence in nonsmokers and nondrinkers or be indicative of compliance or another healthy lifestyle factor that reduces risk. © 2004 Wiley‐Liss, Inc.
Dibenzo[A,L]pyrene‐induced genotoxic and carcinogenic responses are dramatically suppressed in aryl hydrocarbon receptor‐deficient mice
Authors: Nakatsuru Yoko , Wakabayashi Keiji , Fujii‐Kuriyama Yoshiaki , Ishikawa Takatoshi , Kusama Kaoru , Ide Fumio 
Published: June 2004

AbstractDibenzo[a,l]pyrene (DB[a,l]P), a notorious air pollutant, is the most powerful carcinogenic polycyclic aromatic hydrocarbon (PAH) ever tested. Although the carcinogenicity of PAH may be primarily mediated by the aryl hydrocarbon receptor (AhR), the in vivo role of AhR in skin carcinogenesis remains to be defined. In this context, we investigated the genotoxic and carcinogenic responses of the AhR‐deficient mouse skin to DB[a,l]P. A single painting resulted in a striking epidermal hyperplasia in AhR+/+ mice but not in AhR−/− mice. Bromodeoxyuridine‐labeling index and accumulation of p53 protein in epidermal cells of AhR+/+ mice were 8‐ and 33‐fold higher than those of AhR−/− mice, respectively. 32P‐Postlabeling assay for DB[a,l]P‐DNA adducts displayed a 2‐fold increase in the AhR+/+ mouse skin. After DB[a,l]P exposure, AhR−/− mice arranged a nearly 60% reduction in the induction of epidermal cytochrome P450 (CYP)1A1, but CYP1B1 was constitutively expressed in both genotypes of mice, irrespective of DB[a,l]P treatment. As compared with AhR+/+ mice, AhR−/− mice had both significantly lower incidence (100% vs. 33%) and multiplicity (2.7 vs. 0.46) of skin tumors by the complete carcinogenesis study. These observations indicate that a reduced tumor yield in AhR−/− mice may be secondary to reduction of inducible CYP1A1 activation and subsequent DNA adduction. It is evident from our continuous work that although AhR is likely to play a central role in epidermal proliferation and possibly neoplastic transformation, the relative importance of AhR for carcinogenesis may be different among PAH examined. © 2004 Wiley‐Liss, Inc.
Investigation of MRP‐1 protein and MDR‐1 P‐glycoprotein expression in invasive breast cancer: A prognostic study
Authors: Larkin Annemarie , O'Driscoll Lorraine , Kennedy Susan , Purcell Rachel , Moran Elizabeth , Crown John , Parkinson Michael , Clynes Martin 
Published: June 2004

AbstractThe efficacy of breast cancer treatment is limited by the development of resistance to various chemotherapeutic agents. We conducted a retrospective study of the expression of 2 drug resistance efflux pumps, MRP‐1 and MDR‐1 Pgp, in 177 invasive breast carcinomas. Immunohistochemical expression of these proteins was correlated with clinicopathologic characteristics as well as relapse‐free survival (RFS) and overall survival (OS) times. MDR‐1 Pgp was associated strongly with higher histologic grade (grade III). A highly significant association was shown between MDR‐1 Pgp and MRP‐1 expression (p < 0.01), 47.4% of patients expressing both proteins; MRP‐1 was expressed in approximately 61% of patients and MDR‐1, in approximately 66% of patients. No association was shown in the overall group between either MDR‐1 Pgp or MRP‐1 and any of the other clinicopathologic features. Kaplan‐Meier analysis revealed that in a subset of patients with either high‐grade (grade III) stage 1 (node‐negative) or stage 2 (node‐positive) tumours who were treated with surgery followed by adjuvant chemotherapy, MRP‐1 expression in <25% of tumour cells at diagnosis was significantly associated with improved RFS (p < 0.02) and OS (p < 0.02). Using multivariate analysis, MRP‐1 expression in <25% of tumour cells at diagnosis was identified as an independent, significant prognostic factor for RFS (p < 0.01) and OS (p < 0.01) in this patient group but not in other groups. In this subgroup, no significant correlation was observed between expression of MDR‐1 Pgp and MRP‐1. While the number of patients with high‐grade tumours treated with adjuvant chemotherapy was small and further confirmatory research is warranted, it appears that assessment of MRP‐1 expression at diagnosis may offer useful prognostic information in subgroups of patients with stage 1 or stage 2 high‐grade tumours who receive CMF‐based adjuvant chemotherapy. Given the known substrate specificities of MRP‐1, any mechanistic relationship between MRP‐1 expression and CMF resistance remains unclear. No association was shown between MDR‐1 Pgp expression and either RFS or OS time in any subgroup of patients. © 2004 Wiley‐Liss, Inc.
Expression of transforming growth factor‐beta 1 and growth in soft agar differentiate prostate carcinoma‐associated fibroblasts from normal prostate fibroblasts
Authors: San Francisco Ignacio F. , DeWolf William C. , Peehl Donna M. , Olumi Aria F. 
Published: June 2004

AbstractCarcinoma‐associated fibroblasts (CAF) promote tumor progression of pre‐neoplastic epithelial cells. To investigate the basis of this phenomenon, we compared the properties of fibroblasts cultured from normal human prostate (NHPF) to prostate CAF. NHPF and CAF were assayed for growth potential, cell death and proliferative capacity by measuring population doubling time, cell cycle distribution and capability to form colonies in soft agar. Resistance to genotoxic (UV radiation: 0–50 J/cm2) and chemotoxic (0–200 nM Taxol) agents were compared between CAF and NHPF by measuring cell viability and cell cycle analysis. Transforming growth factor β1 (TGF‐β1) immunoreactivity was assessed in non‐malignant and malignant prostatic tissue. No detectable differences were found when comparing CAF and NHPF with respect to population doubling time, cell cycle distribution and response to genotoxic and chemotoxic agents. The mean number of colonies in soft agar was 120.5 for CAF vs. 18.2 for NHPF (p < 0.05). Because TGF‐β1 and matrix metalloproteinase (MMP)‐9 have been associated with growth of fibroblasts in soft agar and tumor promotion, we measured the expression of these factors in NHPF and CAF by ELISA. There was no difference in expression of MMP‐9; however, TGF‐β1 was expressed in higher concentrations in CAF than in NHPF (p < 0.0014). Furthermore, TGF‐β1 expression was higher in the carcinoma‐associated stroma of prostate cancer tissue than stroma of non‐malignant prostatic tissue. Increased capability of CAF as compared to NHPF to form colonies in soft agar may be due to a higher expression of TGF‐β1 and correlates with the ability of CAF to promote malignant progression of prostate epithelial cells. © 2004 Wiley‐Liss, Inc.
The tumor‐suppressive reagent taurolidine is an inhibitor of protein biosynthesis
Authors: Braumann Chris , Henke Wolfgang , Jacobi Christoph A. , Dubiel Wolfgang 
Published: June 2004

AbstractTaurolidine has been successfully used as a disinfectant and to prevent the spreading and growth of tumor cells after surgical excision. However, the underlying mechanisms regarding its effects remain obscure. Here, we show that taurolidine treatment reduces endogenous levels of IκBα, p105, c‐Jun, p53 and p27 in a dose‐dependent manner in colon adenocarcinoma cells, which can be in part due to massive cell death. Because expression of tested proteins was affected by taurolidine, its influence on protein expression was studied. In the coupled transcription/translation system, taurolidine inhibited c‐Jun expression with an IC50 value of 1.4 mM. There was no or little effect on transcription. In contrast, translation of c‐Jun or p53 mRNA was completely inhibited by taurolidine. To determine which step of translation was affected, prominent complexes occurring in the course of translation were analyzed by density gradient centrifugation. In the presence of taurolidine, no preinitiation translation complex was assembled. Taurolidine also suppressed protein expression in bacteria. Based on our data, we conclude that taurolidine blocks a fundamental early phase of translation, which might explain its effects as a disinfectant and inhibitor of tumor growth. © 2004 Wiley‐Liss, Inc.
Structural studies of bioactivity in sol–gel‐derived glasses by X‐ray spectroscopy
Authors: Skipper Laura J. , Sowrey Frank E. , Pickup David M. , Fitzgerald Victoria , Rashid Rumana , Drake Kieran O. , Lin Zhongjie , Saravanapavan Priya , Hench Larry L. , Smith Mark E. , Newport Robert J. 
Published: June 2004

AbstractExtended X‐ray absorption fine structure spectroscopy and X‐ray absorption near edge structure, X‐ray fluorescence spectroscopy, and X‐ray powder diffraction have been used to study the local calcium environment in four sol–gel‐derived bioactive calcium silicate glasses of the general formula (CaO)x(SiO2)1−x. The formation of a hydroxyapatite layer on the composition with the highest bioactivity (x = 0.3) with time has been studied, in an in vitro environment, by immersion in simulated body fluid (SBF) at 37°C. The calcium oxygen environment in the four compositions has been shown to be six‐coordinate in character. Both the extended X‐ray absorption fine structure spectroscopy and X‐ray absorption near edge structure show a gradual increase in coordination number and CaO bond distance with longer exposure to SBF. X‐ray fluorescence show that calcium is quickly lost from the samples on exposure to SBF and the calcium concentration then recovers with time. There is clear evidence that the recovery of calcium content is due to the formation of a CaO‐P2O5‐rich layer. Annealing of samples at 650°C shows the presence of what, on the length scales probed by X‐ray diffraction, appears to be noncrystalline calcium phosphate after 1 h of exposure to an SBF solution, which becomes more crystalline on longer exposure. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res 70A: 354–360, 2004
Effect of heat pressing on the mechanical properties of a mica‐based glass‐ceramic
Authors: Denry I. L. , Holloway J. A. 
Published: June 2004

AbstractPrevious work has shown that heat pressing of mica‐based glass‐ceramics can lead to crystal alignment along the direction of pressing. The purpose of this study was to evaluate the effect of heat pressing on the fracture toughness of mica‐based glass‐ceramics. Glass rods (12 × 60 mm) were prepared by melting the glass composition at 1400 °C for 2 h. Ingots (12 × 12 mm; n = 5) and discs (12 × 1.5 mm; n = 10) were cut from the rods. The discs were heat treated to simulate heat pressing and served as controls. A machinable mica‐based glass‐ ceramic (Dicor MGC) also served as control. Bar‐shaped wax patterns (2 × 4 × 22mm) were invested and heat pressed at 875 °C. The elastic constants were determined with the use of the pulsed ultrasonic velocity method. The fracture toughness was measured by the indentation strength technique. The degree of texture was assessed qualitatively by X‐ray diffraction and quantitatively on digital SEM micrographs. The results showed that the mean fracture toughness of the heat‐pressed specimens (1.96 ± 0.19 MPa · m0.5) was significantly higher than that of the heat‐treated controls (1.51 ± 0.21 MPa · m0.5) or the proprietary mica glass‐ceramic (Dicor MGC; 1.66 ± 0.04 MPa · m0.5) (p < .001). It was concluded that heat pressing led to a significant increase in fracture toughness in mica glass‐ceramics because of crystal alignment along the direction of pressing. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 70B: 37–42, 2004
Effects of laser‐modified polystyrene substrate on CHO cell growth and alignment
Authors: Zhu Bangshang , Lu Qinhua , Yin Jie , Hu Jun , Wang Zongguang 
Published: June 2004

AbstractBiomaterial surface chemistry and nanoscale topography of biomaterials can significantly influence cell behavior in vitro. Polystyrene (PS) Petri dishes were subjected to Nd:YAG laser irradiation at 266 nm, which resulted in well‐defined three‐dimensional (3D) periodic nanoscale surface topographies and surface oxidation. The surface changes were analyzed by X‐ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and a contact‐angle goniometer. The samples were then used to investigate the cell behavior of Chinese hamster ovary (CHO) cells. The surface laser modification affected the CHO cell adhesion and alignment, and caused morphological changes in comparison with unmodified PS. The results obtained from the cell‐behavior studies revealed that nanoscale hydrophilic surface topography cues affected the adhesion, extension, alignment, and morphology of cells. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 70B: 43–48, 2004
Donor age and gender effects on osteoinductivity of demineralized bone matrix
Authors: Traianedes Kathy , Russell James L. , Edwards Jean T. , Stubbs Harrison A. , Shanahan Ileene R. , Knaack David 
Published: June 2004

AbstractAllogeneic demineralized bone matrix (DBM) has been used extensively as a clinical graft material because of its inherent osteoinductive and osteoconductive properties. There is continued debate over the acceptable age range of donors for bone and whether the effectiveness of the tissue as a graft is influenced by gender. Contradictory evidence has been obtained with DBM prepared from both animals and humans. The goal of the present investigation was to evaluate the effect of donor age and gender on the osteoinductivity of DBM prepared from human donors [male (133) and female (115) donors grouped in 10‐year age brackets up to 85 years] with a statistically relevant sample size using the athymic rat ectopic bone formation model. Among males, there was a statistically significant linear association between age and osteoinductivity value (p <.001), but not among females (p =.20). The rate of change among males was 0.009 units per year. The biological relevance of such a small change in osteoinductivity is likely to be negligible, as the total variation explained by the regressions was only 8.2%. A two‐way ANOVA as related to donor age (only donors < 76 years of age) and gender yielded no significant statistical association of osteoinductivity with age group, gender, and their interaction. The results confirm that properly processed demineralized bone from donors through at least 85 years of age is a viable grafting material. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 70B: 21–29, 2004
Color changes of dental resin composites by a salivary enzyme
Authors: Lee Yong‐Keun , Lim Bum‐Soon , Powers John M. 
Published: June 2004

AbstractThe objective of this study was to evaluate the color change (ΔE) of dental resin composites immersed in a salivary enzyme of esterase (ETE, porcine liver esterase, 400 mU/ml) compared to those immersed in phosphate‐buffered saline (PBS). The colors of three brands of resin composites of 13 shades were measured after polymerization and polishing with 1500‐grit SiC paper and after immersion in PBS or ETE up to 9 weeks. Color was measured according to the CIELAB color scale. ΔEafter immersion was calculated by the equation ΔE = [(ΔL*)2 + (Δa*)2 + (Δb*)2]1/2. Surface roughness (Ra) and Vickers hardness number (VHN) were measured. ΔEvalues after immersion in ETE was not higher than those in PBS. Immersion in solutions more than 3 weeks resulted in perceivable color changes (ΔE > 3.3) in one material, and immersion in solutions up to 9 weeks resulted in not‐perceivable color changes in the other materials. Discoloration generally increased as the immersion period increased. For one composite, the value increased abruptly in the period of 3 days to 3 weeks of immersion. The change in Ra value after immersion was varied by the composite and shade. VHN decreased significantly after immersion in ETE for nine weeks. Immersion in PBS resulted in decreased VHN in two composites. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 70B: 66–72, 2004
Fully quantum mechanical energy optimization for protein–ligand structure
Authors: Xiang Yun , Zhang Da W. , Zhang John Z. H. 
Published: June 2004

AbstractWe present a quantum mechanical approach to study protein–ligand binding structure with application to a Adipocyte lipid‐binding protein complexed with Propanoic Acid. The present approach employs a recently develop molecular fractionation with a conjugate caps (MFCC) method to compute protein–ligand interaction energy and performs energy optimization using the quasi‐Newton method. The MFCC method enables us to compute fully quantum mechanical ab initio protein–ligand interaction energy and its gradients that are used in energy minimization. This quantum optimization approach is applied to study the Adipocyte lipid‐binding protein complexed with Propanoic Acid system, a complex system consisting of a 2057‐atom protein and a 10‐atom ligand. The MFCC calculation is carried out at the Hartree–Fock level with a 3‐21G basis set. The quantum optimized structure of this complex is in good agreement with the experimental crystal structure. The quantum energy calculation is implemented in a parallel program that dramatically speeds up the MFCC calculation for the protein–ligand system. Similarly good agreement between MFCC optimized structure and the experimental structure is also obtained for the streptavidin–biotin complex. Due to heavy computational cost, the quantum energy minimization is carried out in a six‐dimensional space that corresponds to the rigid‐body protein–ligand interaction. © 2004 Wiley Periodicals, Inc. J Comput Chem 25: 1431–1437, 2004
BF3 etherate catalysed formation of [11C]methyl esters: a novel radiolabelling technique
Authors: Ackermann U. , Tochon‐Danguy H. J. , Scott A. M. 
Published: June 2004

AbstractA novel way of preparing 11C labelled methyl esters using [11C]methanol and either BF3 etherate or trimethylsilyl chloride as catalyst was investigated. Radiochemical yields with BF3 etherate were between 30 and 33% for [11C]methyl benzoate and less than 1% for [11C]methyl thio salicylate. No [11C]methyl ester formation could be observed with trimethylsilyl chloride for all compounds investigated.This method is an alternative to using [11C]methyl iodide in the presence of a base. It is particularly suited for carboxylic acids bearing functional groups which would compete for [11C]methyl iodide, thus eliminating the need to introduce protecting groups. However, o‐anisic acid formed [11C]methyl salicylate in 33–30% decay corrected radiochemical yield due to hydrolytic cleavage of the methyl ether, and none of the desired [11C]methyl 2‐methoxy benzoate could be obtained. When salicylic acid was used as starting material, [11C]methyl salicylate could only be obtained in 5–8% decay corrected radiochemical yield. Copyright © 2004 John Wiley & Sons, Ltd.