bluuebunny/crossref_metadata_2025_split huggingface dataset:
Population‐based survival analysis of colorectal cancer patients in Singapore, 1968–1992
Authors: Du Wen‐Bo , Chia Kee‐Seng , Sankaranarayanan Rengaswamy , Sankila Risto , Seow Adeline , Lee Hin‐Peng 
Published: August 2002

AbstractSince the 1980s, colorectal cancer incidence in Singapore has ranked second to lung in males and females. We describe a population‐based analysis of survival of colorectal cancer patients diagnosed from 1968 to 1992 in Singapore. Data of colorectal cancer patients diagnosed during 1968–1992 were retrieved from the Singapore Cancer Registry. Patients were passively followed up for death to the end of 1997. The final dataset consisted of 10,114 subjects. Observed and relative survival rates were calculated by stage (localized, regional metastases and distant metastases), age, ethnicity and calendar period for both genders. Over the study period, a significant progress in survival of colorectal cancer patients was observed. For localized cancer of the colon, the 5‐year age‐standardized relative survival (ASRS) increased from 36% in 1968–1972 to 66% in 1988–1992 for males and from 32 to 71% for females. For localized rectal cancer, the 5‐year ASRS improved from 25 to 66% for males and from 23 to 66% in females. Similarly, improvement was observed in colorectal cancer patients with regional metastases, but not in those with distant metastases. Calendar year period and clinical stage of disease were identified as major significant prognostic factors of survival for colorectal cancer. The substantially improved colorectal cancer survival rates reflected the interplay of cancer control activities in various areas, such as health promotion, early diagnosis and treatment. Our study shows a unique changing pattern of survival experience for colorectal patients from a country undergoing rapid economic development. © 2002 Wiley‐Liss, Inc.
Inhibitory effects of a luteinizing hormone‐releasing hormone agonist on basal and epidermal growth factor‐induced cell proliferation and metastasis‐associated properties in human epidermoid carcinoma a431 cells
Authors: Huang Ying‐tang , Hwang Jiuan‐jiuan , Lee Lung‐ta , Liebow Charles , Lee Ping‐ping H. , Ke Ferng‐chun , Lo Tung‐bin , Schally Andrew V. , Lee Ming‐ting 
Published: August 2002

AbstractThe purpose of this study was to investigate the effects of a potent LHRH agonist, [D‐Trp6]LHRH on the basal and EGF‐induced cell proliferation and the metastasis‐associated properties in A431 human epidermoid carcinoma. [D‐Trp6]LHRH time‐dependently inhibited the basal and EGF‐stimulated growth of A431 cancer cells. It is assumed that phosphorylation/dephosphorylation of cellular proteins is highly related to cell growth. This study demonstrates that [D‐Trp6]LHRH decreased the basal and EGF‐induced total cellular kinase activity, particularly the tyrosine phosphorylation of several cellular proteins including the EGFR. In contrast, [D‐Trp6]LHRH did not cause detectable changes in basal and EGF‐stimulated serine/threonine phosphorylation of A431 cellular proteins. The inhibitory effect of [D‐Trp6]LHRH on A431 cell proliferation was associated with apoptosis as evidenced by the cell morphology and DNA integrity (ladder pattern), the expression of interleukin 1β‐converting enzyme (ICE) and activation of caspase. Furthermore, EGF could rescue the remaining attached A431 cells following [D‐Trp6]LHRH treatment for 48 hr, which suggests that limited exposure to [D‐Trp6]LHRH did not channel all cells to irreversible apoptotic process. We also determined the effects of [D‐Trp6]LHRH on metastasis‐associated properties in A431 cells. [D‐Trp6]LHRH reduced both basal and EGF‐stimulated secretion of MMP‐9 and MMP‐2. In addition, [D‐Trp6]LHRH suppressed the basal and EGF‐induced invasive activity of A431 cells based on an in vitro invasion assay. In conclusion, this study indicates that [D‐Trp6]LHRH may act partly through activating tyrosine phosphatase activity to inhibit cell proliferation and the metastasis‐associated properties of A431 cancer cells. Our work suggests that [D‐Trp6]LHRH may be therapeutically useful in limiting the tumor growth and metastasis of some neoplasms. © 2002 Wiley‐Liss, Inc.
Expression of a non‐functional p53 affects the sensitivity of cancer cells to gemcitabine
Authors: Galmarini Carlos María , Clarke Marilyn L. , Falette Nicole , Puisieux Alain , Mackey John R. , Dumontet Charles 
Published: August 2002

AbstractGemcitabine is a relatively new agent with promising activity in solid tumors. Few data are available regarding mechanisms of resistance to gemcitabine downstream from the drug‐target interaction. The present study was performed to gain insight into the role of p53 status on the cytotoxicity of gemcitabine on cancer cells. Drug sensitivity, drug metabolism, cell kinetics and drug‐induced apoptosis were compared in 2 lines derived from the mammary adenocarcinoma MCF‐7: the wildtype p53 (wt‐p53) containing MN‐1 cell line and, the MDD2 line containing a dominant negative variant of the p53 protein (mut‐p53). The MDD2 cell line was significantly more resistant to gemcitabine cytotoxicity than the MN‐1 cell line. The resistant phenotype could not be attributed to a defective gemcitabine activation/degradation pathway or altered levels of expression of intracellular targets. Although both cell lines exhibited p53 accumulation, MN‐1 but not MDD2 cells, displayed p21WAF1 induction after exposure to gemcitabine. Gemcitabine induced an S‐phase arrest in both cell lines. A more pronounced block in G1 phase, however, was observed in MN1 cells. Exposure to gemcitabine induced a higher degree of apoptosis in MN‐1 than in MDD2 cells. This corresponded with suppression of Bcl‐2 and Bcl‐X/L expression in wt‐p53 cells exposed to gemcitabine whereas Bcl‐2 levels remained stable and Bcl‐X/L levels increased in mut‐p53 cells exposed to gemcitabine. We conclude that the p53 status of cancer cells influences their sensitivity to gemcitabine cytotoxicity. Our evidence suggests that loss of p53 function leads to loss of cell cycle control and alterations in the apoptotic cascade, conferring resistance to gemcitabine in cancer cell lines displaying a mut‐p53. © 2001 Wiley‐Liss, Inc.
The ECB monetary policy strategy and the money market
Authors: Gaspar Vítor , Perez‐Quiros Gabriel , Sicilia Jorge 
Published: August 2002

AbstractThis paper aims at contributing to the understanding of how the ECB conducts monetary policy as seen from a money market perspective. More specifically it covers two different issues. First, it looks at the ‘learning period’ for banks since the Eurosystem started implementing the single monetary policy. It shows that during the first three weeks of 1999 the narrow corridor in place during this period was effective in limiting daily volatility of the money market overnight rates. In addition, the behaviour of banks and market rates during this period provides evidence that learning was taking place. Second, it looks at how well money market participants have anticipated the monetary policy decisions taken by the ECB. To do so, the paper analyses whether the announcements of monetary policy decisions to maintain or change interest rates impact on the stochastic behaviour of interest rates. Looking at the EONIA rates within the reserve maintenance periods, we find that the announcement of monetary policy decisions does not change significantly the level or volatility of overnight rates. Copyright © 2001 John Wiley & Sons, Ltd.
Rrepresentations of trauma in infancy: Clinical and theoretical implications for the understanding of early memory
Authors: Gaensbauer Theodore J. 
Published: August 2002

AbstractUnderstanding the nature of the infant's internal experience is a crucial prerequisite for delineating the developmental effects of an early trauma. In addition, to the extent that internal representations of a trauma can be traced over time, traumatic experiences present unique opportunities for the study of early memory. This article will describe case vignettes of children who experienced a trauma in the preverbal period and who evidenced forms of memory of their trauma at subsequent points in time. In conjunction with the clinical material, developmental research bearing on the types of early memories described will be discussed. The clinical data, reinforced by research findings, indicate that preverbal children, even in the first year of life, can establish and retain some form of internal representation of a traumatic event over significant periods of time. The specificity and enduring nature of the internal representations suggest that specific therapeutic interventions over and above general comforting will be required if an infant is to maximally recover from a trauma. The clinical findings have relevance for a number of issues currently under debate in the area of infant memory, including the role of reminders in memory retention, the nature of early memory systems, and the development of autobiographical memory. ©2002 Michigan Association for Infant Mental Health.
Estimating economic relationships subject to firm‐ and time‐varying equality and inequality constraints
Authors: O'Donnell Christopher J. , Rambaldi Alicia N. , Doran Howard E. 
Published: August 2002

AbstractApplied econometricians often fail to impose economic regularity constraints in the exact form economic theory prescribes. We show how the Singular Value Decomposition (SVD) Theorem and Markov Chain Monte Carlo (MCMC) methods can be used to rigorously impose time‐ and firm‐varying equality and inequality constraints. To illustrate the technique we estimate a system of translog input demand functions subject to all the constraints implied by economic theory, including observation‐varying symmetry and concavity constraints. Results are presented in the form of characteristics of the estimated posterior distributions of functions of the parameters. Copyright © 2001 John Wiley & Sons, Ltd.
Possible androgenic/anti‐androgenic activity of the insecticide fenitrothion
Authors: Sohoni P. , Lefevre P. A. , Ashby J. , Sumpter J. P. 
Published: August 2002

AbstractTo date, within the field of endocrine disruption, much focus has been placed on chemicals that mimic oestrogens (so‐called xenoestrogens), and the number of such chemicals apparently detected continues to grow steadily. Less effort has been expended on investigating chemicals that mimic, or antagonize, other hormones. Nevertheless, a number of chemicals have been reported to have a weak affinity for the androgen receptor, all of which have, to date, been found to have anti‐androgenic activity in vivo. In this report, we present evidence that the insecticide fenitrothion can interact with the androgen, but not with the oestrogen, receptor. Using recombinant yeast expressing the human androgen receptor, we found that fenitrothion behaved as an androgen agonist in vitro when tested alone, and that it could antagonize the androgen DHT when both chemicals competed for the androgen receptor in vitro. In vivo studies using both intact and castrated male rats showed no conclusive androgenic or anti‐androgenic responses. Changes in organ weights suggestive of anti‐androgenic effects were mitigated against by the reduced body weights of fenitrothion‐treated rats. The toxicity of the compound precluded the use of higher dose levels to substantiate any tentative findings. Interestingly, fenitrothion (and related insecticides) is structurally similar to flutamide, an anti‐androgen used clinically that gives clearly positive responses in both intact and castrated rats. Copyright © 2001 John Wiley & Sons, Ltd.
Theoretical analysis of adsorption thermodynamics for hydrophobic peptide residues on SAM surfaces of varying functionality
Authors: Latour Robert A. , Rini Christopher J. 
Published: August 2002

AbstractAt a fundamental level, protein adsorption to a synthetic surface must be strongly influenced by the interaction between the peptide residues presented by the protein's surface (primary protein structure) and the functional groups presented by the synthetic surface. In this study, semi‐empirical molecular modeling was used along with experimental wetting data to theoretically approach protein adsorption at this primary structural level. Changes in enthalpy, entropy, and Gibbs free energy were calculated as a function of residue–surface separation distance for the adsorption of individual hydrophobic peptide residues (valine, leucine, phenylalanine) on alkanethiol self‐assembled monolayers on gold [Au−S(CH2)15−X; X = CH3, OH, NH3+, COO−]. The results predict that the adsorption of each type of hydrophobic residue is energetically favorable and entropy dominated on a methyl‐terminated hydrophobic surface, energetically unfavorable and enthalpy dominated on a hydroxyl‐terminated neutral hydrophilic surface, and very slightly favorable to unfavorable and enthalpy dominated on charged surfaces. These theoretical results provide a basis for understanding some of the fundamental effects governing protein adsorption to synthetic surfaces. This level of understanding is needed for the proactive design of surfaces to control protein adsorption and subsequent cellular response for both implant and tissue engineering applications. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res 60: 564–577, 2002
Evaluation of nanostructured carbonated hydroxyapatite coatings formed by a hybrid process of plasma spraying and hydrothermal synthesis
Authors: Han Yong , Xu Kewei , Montay Gillaume , Fu Tao , Lu Jian 
Published: August 2002

AbstractCarbonated hydroxyapatite (CHA) coatings on a titanium alloy were prepared by hydrothermal synthesis of precursors plasma‐sprayed with brushite as a raw powder. The structures, residual stresses, and bond strengths of the precursors and CHA coatings were investigated. The results showed that the sprayed precursors consisted of β‐Ca2P2O7, α‐Ca3(PO4)2, and CaHPO4, whereas the CHA coatings exhibited a unique phase construction, nanostructured and needlelike crystals, and a fairly low tensile residual stress. The bond strength of a CHA coating 200 μm thick was 15 MPa, equivalent to that of a plasma‐sprayed hydroxyapatite (HA) coating. The evaluation of the CHA coatings was performed together with that of plasma‐sprayed HA coatings immersed in distilled water. The dissolution and bond‐strength degradation of the CHA coatings were much lower than those of the plasma‐sprayed HA coatings. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res 60: 511–516, 2002
Mechanical properties and osteoconductivity of new bioactive composites consisting of partially crystallized glass beads and poly(methyl methacrylate)
Authors: Shinzato Shuichi , Nakamura Takashi , Ando Keiji , Kokubo Tadashi , Kitamura Yoshiro 
Published: August 2002

AbstractNew bioactive composites consisting of partially crystallized glass beads as inorganic fillers and poly(methyl methacrylate) (PMMA) as an organic matrix were developed. Two kinds of partially crystallized glass beads, designated Cry820 and Cry850, were newly prepared by the heating of MgO–CaO–SiO2–P2O5 glass at 820 and 850°C, respectively. The glass beads were mixed with PMMA to form two new composites designated Cry820C and Cry850C, respectively. The goal of this study was to produce a highly osteoconductive and mechanically strong composite cement with these new fillers. A previously reported composite cement designated AWC, which was composed of apatite‐ and wollastonite‐containing glass ceramic (AW‐GC) as a powder filler and the same PMMA polymer used in the new composites, was used as a reference material. The quantity of filler added to each composite was 70 wt %. The bending strength of Cry820C was significantly higher than that of Cry850C. Composites were packed into intramedullary canals of rat tibiae to evaluate their osteoconductivity, as determined by an affinity index. The affinity index, which equaled the length of bone in direct contact with the composite surface expressed as a percentage of the total length of the composite surface, was calculated for each composite. The rats were euthanized at 4, 8, and 25 weeks after implantation. At each time interval studied, Cry820C showed a significantly higher affinity index than AWC up to 25 weeks after implantation. Cry850C showed a significantly higher affinity index than AWC up to 8 weeks and a higher affinity index than AWC at 25 weeks, although the difference was not significant. The values for each composite increased significantly with time up to 25 weeks. Our study revealed that the higher osteoconductivity of the new composites was due to the larger quantity of the glassy phase of the crystallized glass beads at the composite surface and the lower solubility of the PMMA powder to methyl methacrylate monomer. In addition, the spherical shape of the crystallized glass beads gave the new composites strong enough mechanical properties to be useful under weight‐bearing conditions. The new composites show promise as alternatives, with improved properties, to conventional PMMA bone cement. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res 60: 556–563, 2002
Polyethylene wear characteristics in vivo and in a knee stimulator
Authors: Beaulé P. E. , Campbell P. A. , Walker P. S. , Schmalzried T. P. , Dorey F. J. , Blunn G. W. , Bell C. J. , Yahia L'H. , Amstutz H. C. 
Published: August 2002

AbstractValidation of a wear simulator requires that the device produce a similar type and amount of wear and particles of a comparable morphology as occurs clinically. Using techniques previously established to compare polyethylene particles from hip simulators to those from retrieved tissues, particles isolated from six revised posterior stabilized knee replacements were characterized and compared to particles generated from the same knee design worn in a knee simulator. The particles produced in the knee simulator were of comparable size but had less variability in their form factor compared to the particles produced in vivo. Comparable wear features were seen on the articulating surfaces in both groups. These results indicate that this knee joint simulator is able to reproduce a baseline type of wear that is similar to that in vivo and should encourage further use of this device to better understand knee component wear and function. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res 60: 411–419, 2002; DOI 10.1002/jbm.10139
Adhesion barriers of carboxymethylcellulose and polyethylene oxide composite gels
Authors: Liu Lin‐Shu , Berg Richard A. 
Published: August 2002

AbstractComposite gels and films of CMC and PEO have been used to separate healing tissues and have been demonstrated to reduce postsurgical adhesions in animal models of adhesion formation. Gels of CMC/PEO were studied here to elucidate the mechanism by which the combination of PEO with CMC is effective in reducing adhesions between tissues. CMC and PEO were demonstrated to undergo micro phase separation to form a two‐phase system. Protein partitioning was measured in this system for albumin, fibrinogen, and gamma globulin. All of these proteins were found to partition preferentially into the CMC phase. When gels of CMC and PEO were examined for tissue adherence, the addition of PEO reduced the adherence of CMC to tissues. To further investigate the effects of PEO on tissue adherence of the gel, the extent of thrombus formation of citrated blood initiated by calcium chloride in CMC/PEO gels was measured in vitro. The extent of thrombus formation by CMC was reduced proportionally to the content of PEO in gels of CMC/PEO. A model was developed to explain how CMC and PEO contribute to the effectiveness of CMC/PEO gels that form a barrier between healing tissues to reduce postsurgical adhesions. In an open system PEO is released from the gel faster than CMC is dissolved, resulting in a shell structure with CMC coated by PEO. The PEO‐rich outer layer functions to inhibit protein deposition and thrombus formation. The CMC‐rich layer functions to anchor the gel to the tissue surface. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res (Appl Biomater) 63: 326–332, 2002
Bone morphogenetic protein 3b expressing reindeer antler
Authors: Kapanen A. , Ryhänen J. , Birr E. , Väänänen H. K. , Tuukkanen J. 
Published: August 2002

AbstractA cDNA sequence of bone morphogenetic protein 3b (BMP‐3b) of reindeer antler was produced with degenerative homology primers in polymerase chain reaction (PCR). An in situ hybridization study of BMP‐3b mRNA in 1‐month‐old antler showed expression in most differentiated cells in the antler center. In addition, the bone‐inductive capacity of the reindeer antler matrix was evaluated. Decalcified and powdered antler matrix of different stages of antler maturity was implanted in gelatin capsules under the rat dorsal muscle fascia for two implantation periods: 3 and 8 weeks. Allogenic matrix prepared from rat long bones was used as a positive control implant. Heterotopic ossification was evaluated histomorphometrically and densitometrically. Allogenic bone matrix induced rapid osteogenesis and mineral accumulation. Both endochondral and intramembranous ossification was evident, endochondral ossification being the dominant form. Mineral density in the induced ossicle was 115 ± 48 mg/cm3 as early as at 3 weeks and 350 ± 69 mg/cm3 at 8 weeks. The proportional areas of von Kossa‐stained mineral were 3.67 ± 2.1% and 11.6 ± 0.07%, respectively. The antler preparations induced mineralization, but significantly less than the allogenic bone matrix. At 8 weeks, mineral density was significantly lower in the cast antler preparation than in the allogenic implants. The morphology of the mineralized areas of the antler preparations showed no ossification. © 2001 Wiley Periodicals, Inc. J Biomed Mater Res 59: 78–83, 2002
Metabolic heat production as a measure of macrophage response to particles from orthopedic implant materials
Authors: Charlebois S. J. , Daniels A. U. , Smith R. A. 
Published: August 2002

AbstractAn in vitro method to gauge metabolic heat response of macrophages (MØ) to particulates is described. Whereas the majority of work cited relies on chemical analysis to assess MØ response to particles, we have used isothermal microcalorimetry (IMC) for direct continuous measurement of metabolic heat production to gauge the response. IMC is a screening method, in that it ensures that no energy‐consuming phagocytic response goes undetected, and that the aggregate metabolic magnitude of the responses is determined. A four‐well IMC was used in all microcalorimetric measurements. To accommodate “zero‐time” monitoring of the interaction of particles and cells, a set of identical test chambers was constructed for use in the IMC. MØs were injected from outside the IMC onto particles contained in collagen or gelatin on glass coverslips at the bottom of each chamber. IMC runs were performed using MØs only, MØs and lipopolysaccharide (LPS) positive control, and MØs and clean or LPS‐bound particles of either high‐density polyethylene (HDPE) or cobalt–chrome alloy (CoCr). Total heat produced by the negative controls (MØs alone) was lower than for MØ exposure to LPS or particles. The trend was a higher response for LPS‐bound HDPE compared with clean HDPE particles, though not significant. In conclusion, our results have shown that IMC can be used to detect the heat associated with the phagocytosis of particulate materials by MØs in vitro. © 2001 Wiley Periodicals, Inc. J Biomed Mater Res 59: 166–175, 2002