bluuebunny/crossref_metadata_2025_split huggingface dataset:
k‐Version of finite element method in 2‐D polymer flows: Oldroyd‐B constitutive model
Authors: Surana K. S. , Mohammed A. , Reddy J. N. , TenPas P. W. 
Published: May 2006

AbstractIn this paper, a new mathematical framework based on h, p, k and variational consistency (VC) of the integral forms is utilized to develop a finite element computational process of two‐dimensional polymer flows utilizing Oldroyd‐B constitutive model. Alternate forms of the choices of dependent variables in the governing differential equations (GDEs) are considered and is concluded that u, v, p, τ choice yielding strong form of the GDEs is meritorious over others. It is shown that: (a) since, the differential operator in the GDEs is non‐linear, Galerkin method and Galerkin method with weak form are variationally inconsistent (VIC). The coefficient matrices in these processes are non‐symmetric and hence may have partial or completely complex basis and thus the resulting computational processes may be spurious. (b) Since the VC of the VIC integral forms cannot be restored through any mathematically justifiable means, the computational processes in these approaches always have possibility of spurious solutions. (c) Least squares process utilizing GDEs in u, v, p, τ (strong form of the GDEs) variables (as well as others) is variationally consistent. The coefficient matrices are always symmetric and positive definite and hence always have a real basis and thus naturally yield computational processes that are free of spurious solutions. (d) The theoretical solution of the GDEs are generally of higher order global differentiability. Numerical simulations of such solutions in which higher order global differentiability characteristics of the theoretical solution are preserved, undoubtedly requires local approximations in higher order scalar product spaces ${H}^{k,p}(\bar{\Omega}_{e})$. (e) LSP with local approximations in ${H}^{k,p}(\bar{\Omega}_{e})$ spaces provide an incomparable mathematical and computational framework in which it is possible to preserve desired characteristics of the theoretical solution in the computational process. Numerical studies are presented for fully developed flow between parallel plates and a lid driven square cavity. M1 fluid is used in all numerical studies. The range of applicability of the Oldroyd‐B model or lack of it is examined for both model problems for increasing De. A mathematical idealization of the corners where stationary wall meets the lid is presented and is shown to simulate the real physics when the local approximations are in higher order spaces and when hd→0. For both model problems shear rate $\hat{\dot{\gamma}}$ is examined in the flow domain to establish validity of the Oldroyd‐B constitutive model. Copyright © 2006 John Wiley & Sons, Ltd.
Mutational dynamics in human tumors confirm the neutral intrinsic instability of the mitochondrial D‐loop poly‐cytidine repeat
Authors: Schwartz Simó , Alazzouzi Hafid , Perucho Manuel 
Published: May 2006

AbstractSomatic mutations at a mitochondrial noncoding polycytidine (C)n repeat (polyC) have been associated with tumor progression. We analyzed whether these alterations are due to the inherent mutability of repeated sequences. Insertion and deletion mutations were found in colon (n = 114), stomach (n = 105), endometrium (n = 53), breast (n = 45), lung (n = 35), and prostate (n = 20) tumors. The mutation frequency in colon, gastric, and endometrial tumors was 23, 17, and 11%, respectively, which paralleled the relative extent of microsatellite instability in long mononucleotide repeats observed in tumors with mismatch repair deficiency (colon > stomach > endometrium, relative ratio 10:8:4). Colon tumors with mutations of more than one nucleotide were more advanced in tumor progression. Further, two tumors showing a T > C mutation that restored the homopolymeric repeat, harbored sequential deletion mutations of up to 4 and 6 nucleotides. These results illustrate that the increased mutability of repeated mitochondrial sequences is dependent on the repetitive structure of the DNA molecule and suggest that mutations in the (C)n repeat, whether homoplasmic or not, and by extrapolation, mitochondrial mutations in general, are not the result of selective pressure during tumorigenesis. We also suggest that the (C)n repeat may be used as an universal molecular clock to estimate the relative mitotic history of tumors. © 2006 Wiley‐Liss, Inc.
Prognostic significance of cyclin A in gastric cancer
Authors: Mrena Johanna , Wiksten Jan‐Patrik , Kokkola Arto , Nordling Stig , Haglund Caj , Ristimäki Ari 
Published: May 2006

AbstractHigh level of cyclin A promotes carcinogenesis, and overexpression of cyclin A has been associated with poor prognosis of cancer patients. We validated the prognostic role of cyclin A in gastric cancer and evaluated its correlation with expression of an mRNA stability factor HuR. From 342 consecutive histologically confirmed gastric cancer patients were obtained 325 representative tissue specimens for cyclin A and 316 for HuR immunohistochemistry. Specimens were stained by cyclin A and HuR specific monoclonal antibodies. Nuclear immunostaining detected in ≥≥≥≥5% of the tumor cells was considered the cut‐off for cyclin A positivity. Positive HuR immunoreactivity was scored as nuclear or cytoplasmic. Associations between scores, clinicopathological factors and survival were calculated by the χ2‐test, Fisher's exact test, Kaplan‐Meier test and Cox model. Cyclin A detected in the nuclei of cancer cells was positive in 55% (179 of 325) of the specimens; 40% (127 of 316) of the specimens had cytoplasmic and 88% (279of 316) nuclear immunoreactivity of HuR. Cyclin A expression was an independent prognostic factor for poor survival. Cyclin A immunoreactivity was associated with old age, high stage, proximal location of the tumor, intestinal type, noncurative resection, advanced penetration depth and with nodal metastases but not distant metastases. Furthermore, cyclin A expression was associated with cytoplasmic HuR expression, whereas no association with nuclear HuR was evident. Cyclin A is an independent prognostic factor in gastric cancer, and one mechanism for its overexpression may depend on cytoplasmic localization of HuR. © 2006 Wiley‐Liss, Inc.
Prevalence and determinants of human papillomavirus infection in men attending vasectomy clinics in Mexico
Authors: Vaccarella Salvatore , Lazcano‐Ponce Eduardo , Castro‐Garduño José Antonio , Cruz‐Valdez Aurelio , Díaz Vicente , Schiavon Rafaela , Hernández Pilar , Kornegay Janet R. , Hernández‐Avila Mauricio , Franceschi Silvia 
Published: May 2006

AbstractLarge studies of genital human papillomavirus (HPV) infection in men are few and mainly include high‐risk groups. We interviewed 779 men who requested a vasectomy in 27 public clinics in 14 states of Mexico. Exfoliated cells were obtained from the scrotum, the shaft of the penis, the top of the penis including the coronal sulcus, the glans and the opening of the meatus. HPV testing was performed using biotinylated L1 consensus primers and reverse line blot. Unconditional logistic regression was used to estimate odds ratios (ORs) of being HPV‐positive and corresponding 95% confidence intervals (CIs). The prevalence of any type of HPV was 8.7%. HPV positivity was highest among men below age 25 (13.6%), and lowest among men aged 40 years or older (6.0%). The most commonly found HPV types were, in decreasing order, HPV59, 51, 6, 16 and 58. Lifetime number of sexual partners was associated with HPV positivity (OR for ≥4 vs. 1 partner = 3.7, 95% CI: 2.0–6.8), mainly on account of the strong association with number of occasional and sex‐worker partners. Condom use with both regular (OR = 0.4, 95% CI: 0.1–1.0) and sex‐worker (OR = 0.1, 95% CI: 0.0–0.3) partners and circumcision (OR = 0.2, 95% CI: 0.1–0.4) were inversely associated with HPV positivity. HPV prevalence in Mexican men was similar to the prevalence found in Mexican women of the same age groups. The association between HPV positivity and lifetime number of sexual partners in the present low‐risk male population is one of the strongest ever reported in studies in men. Condom use and circumcision were associated with a strong reduction in HPV prevalence. © 2006 Wiley‐Liss, Inc.
A highly specific real‐time RT‐PCR method for the quantitative determination of CK‐19 mRNA positive cells in peripheral blood of patients with operable breast cancer
Authors: Stathopoulou Aliki , Ntoulia Maria , Perraki Maria , Apostolaki Stella , Mavroudis Dimitris , Malamos Nikos , Georgoulias Vassilis , Lianidou Evi S. 
Published: May 2006

AbstractThe aim of the present study was to decrease the incidence of false positives and to better characterize marginally cytokeratin‐19 (CK‐19) mRNA positive peripheral blood samples from patients with early stage breast cancer. A new set of highly specific primers for CK‐19, which avoids amplification of contaminating genomic DNA, was designed and evaluated to improve the specificity and sensitivity of the previously described methodology. The primers were specifically designed to avoid amplification of contaminating genomic DNA and CK‐19 pseudogenes. The breast cancer cell line MCF‐7 was used as positive control for the development and analytical evaluation of the assay, while peripheral blood samples from 62 healthy female individuals and 160 patients with early breast cancer were used for the evaluation of the sensitivity and specificity of the new primer pair. The novel designed primer pair was highly sensitive, as it detects up to 1 MCF‐7 cell, and specific as none of the healthy individuals had detectable CK‐19 mRNA positive cells in their peripheral blood. CK‐19 mRNA positive cells were detected in 33 out of 160 (20.6%) patients with early breast cancer. Results obtained by the proposed optimized real‐time RT‐PCR protocol correlated well with those obtained in the same samples by our previously reported quantitative real‐time RT‐PCR [concordance in 198/222 (89.2%), p = 0.0022, McNemar test]. The improved method eliminates the incidence of false positives and is highly sensitive and specific. The method could be used in a clinical setting in the near future for continuous monitoring and quantification of circulating epithelial cells in the peripheral blood of patients with operable breast cancer, provided that a quite larger number of clinical samples with a known follow‐up will be analyzed. © 2006 Wiley‐Liss, Inc.
Food patterns and risk of breast cancer: A factor analysis study in Uruguay
Authors: Ronco Alvaro L. , De Stefani Eduardo , Boffetta Paolo , Deneo‐Pellegrini Hugo , Acosta Giselle , Mendilaharsu María 
Published: May 2006

AbstractTo generate broad eating patterns, which could explain more adequately the breast cancer etiology, we conducted an exploratory factor analysis in Montevideo, Uruguay. The study included 442 newly diagnosed and microscopically confirmed cases with breast cancer and 442 hospitalized controls, with non‐neoplastic diseases. Factor analysis (principal components) was conducted in the control series, and as a result, 6 factors were extracted. These factors were labeled as traditional, healthy, western, stew, high‐fat and drinker. The model explained 58.3% of the variance. After scoring the rotated factors, the relations between scores and breast cancer risk factors were analyzed by using Pearson correlation coefficients. After this step, the odds ratios of breast cancer for continuous scores of the rotated factors were carefully analyzed. The highest risk was directly associated with the western diet (OR 1.31, 95% CI 1.13–1.51), whereas the traditional (OR 0.77, 95% CI 0.64–0.93), healthy (OR 0.84, 95% CI 0.73–0.98) and stew (OR 0.83, 95% CI 0.71–0.98) diets were significantly protective. Women who reported a history of breast cancer among mother and sisters displayed strong elevations in risk for western (OR 2.03, 95% CI 1.11–3.72) and high‐fat (OR 2.72, 95%CI 1.16–6.37) dietary patterns. This finding could suggest that gene–dietary interaction could play an important role in breast carcinogenesis. © 2006 Wiley‐Liss, Inc.
Adenovirus‐mediated tBid overexpression results in therapeutic effects on p53‐resistant hepatocellular carcinoma
Authors: Miao Ji , Chen George G. , Chun Suk‐Ying , Yun Jing‐Ping , Chak Ernest C.W. , Ho Rocky L.K. , Lai Paul B.S. 
Published: May 2006

AbstractHepatocellular carcinoma (HCC) is one of the most common malignancies worldwide with a very high mortality. Because the success of the conventional therapies is limited, gene therapy may represent an alternative for HCC management. Our earlier study has shown that Bid plays a role in the development of HCC. The aim of our study is to evaluate the possibility of using truncated Bid (tBid) as a novel therapy for HCC treatment. Two HCC cell lines, Hep3B and PLC/PRF/5, were used in the experiment. Hep3B was a p53‐resistant while PLC/PRF/5 a p53‐sensitive. A recombinant adenovirus‐Ad/AFPtBid, which contained a tBid gene driven by an α‐fetoprotein (AFP) promoter, was constructed. Both Hep3B and PLC/PRF/5 cells infected with Ad/AFPtBid showed a significant decrease in cell viability. The decrease in cell viability by Ad/AFPtBid resulted from apoptosis of HCC cells, evident by enhanced activity of caspases and increased release of cytochrome c. In vivo experiment was performed by the intratumor injection of Ad/AFPtBid in nude mice inoculated with Hep3B. Ad/AFPtBid injection significantly inhibited tumor growth, and tumor tissues showed a marked increase in TUNEL‐positive cells. Our experiment also demonstrated that Ad/AFPtBid only targeted AFP‐producing cells but not those non‐AFP producing cells. In conclusion, these results indicate that the introduction of Ad/AFPtBid can not only significantly but specifically kill HCC cells that produce AFP. The cell death induced by Ad/AFPtBid in HCC cells is via an apoptotic pathway that can be independent of p53 status. © 2006 Wiley‐Liss, Inc.
Secular trends and geographic variations of hepatitis B virus and hepatitis C virus‐associated hepatocellular carcinoma in Taiwan
Authors: Lu Sheng‐Nan , Su Wei‐Wen , Yang Sheng‐Shun , Chang Ting‐Tsung , Cheng Ken‐Sheng , Wu Jaw‐Ching , Lin Hans Hsienhong , Wu Shun‐Sheng , Lee Chuan‐Mo , Changchien Chi‐Sin , Chen Chien‐Jen , Sheu Jin‐Chuan , Chen Ding‐Shinn , Chen Chien‐Hung 
Published: May 2006

AbstractEtiological variations in hepatocellular carcinoma (HCC) exist across different geographic areas. To gain better control of HCC, we retrospectively studied the secular trends and geographic variations in hepatitis B virus (HBV)‐related and hepatitis C virus (HCV)‐related HCCs in Taiwan. A total of 18,423 HCC cases enrolled in 8 medical centers from 1981 to 2001 were reviewed. Overall, 67% of male HCC in Taiwan was related to HBV infection whereas 55.2% of female HCC in Taiwan was related to HCV infection. The mean age of patients with HBV‐related HCC was 53.2 ± 13.6 years, while the mean age of patients with HCV‐related HCC was 65.1 ± 9.1 years (p < 0.001). The male/female ratio was 6.4 for HBV‐related HCC, while it was 1.7 for the HCV‐related HCC (p < 0.001). The percentage of HBV‐related HCC progressively decreased from 81.5 to 66.2% in males, and from 66.7 to 41.4% in females over the study period. Our study demonstrates that the percentage of HBV‐related HCC has progressively decreased over the last 20 years. The relative decrease in HBV‐related HCC was not due to a decrease in HBV‐related HCC death. Instead, it was caused by an increase in HCV‐related HCC. Prevention of new HCV infection and the treatment of chronic hepatitis C should be the primary goals, which will result in better control of HCC in the future, even in an HBV‐endemic area like Taiwan. © 2006 Wiley‐Liss, Inc.
CYP24, the enzyme that catabolizes the antiproliferative agent vitamin D, is increased in lung cancer
Authors: Parise Robert A. , Egorin Merrill J. , Kanterewicz Beatriz , Taimi Mohammed , Petkovich Martin , Lew April M. , Chuang Samuel S. , Nichols Mark , El‐Hefnawy Talal , Hershberger Pamela A. 
Published: May 2006

Abstract1α,25‐Dihydroxyvitamin D3 (1,25D3) displays potent antiproliferative activity in a variety of tumor model systems and is currently under investigation in clinical trials in cancer. Studies were initiated to explore its potential in nonsmall cell lung cancer (NSCLC), as effective approaches to the treatment of that disease are needed. In evaluating factors that may affect activity in NSCLC, the authors found that CYP24 (25‐hydroxyvitamin D3‐24‐hydroxylase), the enzyme that catabolizes 1,25D3, is frequently expressed in NSCLC cell lines but not in the nontumorigenic bronchial epithelial cell line, Beas2B. CYP24 expression by RT‐PCR was also detected in 10/18 primary lung tumors but in only 1/11 normal lung tissue specimens. Tumor‐specific CYP24 upregulation was confirmed at the protein level via immunoblot analysis of patient‐matched normal lung tissue and lung tumor extracts. Enzymatically active CYP24 is expected to desensitize NSCLC cells to 1,25D3. The authors therefore implemented a high performance liquid chromatography‐tandem mass spectrometry (HPLC‐MS/MS) assay for 1,25D3 and its CYP24‐generated metabolites to determine whether NSCLC cells express active enzyme. Analysis of NSCLC cell cultures revealed time‐dependent loss of 1,25D3 coincident with the appearance of CYP24‐generated metabolites. MK‐24(S)‐S(O)(NH)‐Ph‐1, a specific inhibitor of CYP24, slowed the loss of 1,25D3 and increased 1,25D3 half‐life. Furthermore, combination of 1,25D3 with MK‐24(S)‐S(O)(NH)‐Ph‐1 resulted in a significant decrease in the concentration of 1,25D3 required to achieve maximum growth inhibition in NSCLC cells. These data suggest that increased CYP24 expression in lung tumors restricts 1,25D3 activity and support the preclinical evaluation of CYP24 inhibitors for lung cancer treatment. © 2006 Wiley‐Liss, Inc.
HPV16‐E6 associated hTERT promoter acetylation is E6AP dependent, increased in later passage cells and enhanced by loss of p300
Authors: James Michael A. , Lee John H. , Klingelhutz Aloysius J. 
Published: May 2006

AbstractThe E6 oncoprotein from high‐risk HPV types activates human telomerase reverse transcriptase (hTERT) transcription in human keratinocytes. Studies on how E6 regulates hTERT have implicated E‐box or X‐box elements in the hTERT promoter (Veldman et al., Proc Natl Acad Sci USA 2003;100:8211–14; Oh et al., J Virol 2001;75:5559–66; Gewin et al., Genes Dev 2004;18:2269–82), but the mechanism of activation by E6 is still controversial and not well defined. Here, we demonstrate that induction of both hTERT expression and telomerase activity by HPV‐16 E6 in early passage keratinocytes is associated with acetylation of histone H3 at the hTERT promoter, is dependent on the E6 associated protein (E6AP) and is not exclusively reliant on E‐box or X‐box elements. Further increases in histone acetylation of the hTERT promoter and hTERT transcriptional activity in E6 expressing cells that had been passaged extensively in culture were found to occur only with the endogenous promoter and not with an exogenously introduced hTERT promoter construct. Telomerase activity at both early and late passages, however, was dependent on E6AP expression, implying a continued reliance on E6 function for telomerase activity. Our results demonstrate that E6 induces hTERT promoter acetylation, but that further increases in telomerase activity and histone acetylation in later passage E6 expressing cells are independent of E6 activation of the core hTERT promoter. We also provide evidence that the transcription factor p300 is a potential repressor of telomerase activation and histone acetylation in the context of E6 expression. These studies give insight into how immortalization by HPV results in upregulation of hTERT and furthers our understanding of how telomerase is activated during the process of malignant transformation. © 2006 Wiley‐Liss, Inc.
A BAC library for the goldfish Carassius auratus auratus (Cyprinidae, Cypriniformes)
Authors: Luo Jing , Lang Michael , Salzburger Walter , Siegel Nicol , Stölting Kai N. , Meyer Axel 
Published: May 2006

AbstractA goldfish (Carassius auratus auratus) bacterial artificial chromosome genomic library (BAC library) was constructed from one aquarium‐bred male specimen (tetraploid, 4n=100, genome size=3.52 pg/cell). The library consists of 128,352 positive clones with an average insert size of 150.4 kb, covering the genome 11‐fold. All clones were spotted onto nylon filters and thus are available for screening of genomic regions of interest, such as candidate genes, gene families, or large‐sized syntenic DNA regions of cyprinid species. Preliminary screens with two genes were conducted with hybridizing probes to the genes RAG1 and lgi1. RAG1 is a single‐copy gene in zebrafish and is duplicated in C. a. auratus. We found a very close correlation between the number of positive BAC clones and the expected library coverage. Two copies of lgi1 were found in zebrafish. We have detected four different copies in C. a. auratus, not in the expected abundance, which indicates some variation in the coverage of the BAC library. The preliminary screens indicate that many duplicated genes that resulted from the ancient fish‐specific genome duplication persist in the tetraploid goldfish genome. Hence, the BAC library will provide a useful resource for the future work on comparative genomics, polyploidy, diploidization, and evolutionary genomics in fishes. J. Exp. Zool. (Mol. Dev. Eiol.) 306B, 2006. © 2006 Wiley‐Liss, Inc.
A novel interpretation of the hyperbolization method used to solve the parabolic neutron diffusion equations by means of the wave digital concept
Authors: Luhmann Katrin , Ochs Karlheinz 
Published: May 2006

AbstractIn this paper, the neutron diffusion equations in two energy groups will be dealt with. The underlying parabolic differential equations as well as a hyperbolized version of them will be numerically solved with the wave digital concept. While the hyperbolization process avoids delay‐free directed loops in the wave flow diagram, a direct implementation of the parabolic differential equations does not. However, an iteration method can be used to overcome these problems. This results under certain conditions in the same wave digital model. This way, it can be shown that the commonly used hyperbolization can be interpreted as the application of an iteration method. Copyright © 2006 John Wiley & Sons, Ltd.