bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysing public preferences for cancer screening programmes
Authors: Gyrd‐Hansen Dorte , Søgaard Jes
Published: August 2002

Economic evaluations generally fail to incorporate elements of intangible costs and benefits, such as anxiety and discomfort associated with the screening test and diagnostic test, as well as the magnitude of utility associated with a reduction in the risk of dying from cancer. In the present analysis, 750 respondents were interviewed and asked to rank, according to priority, a number of alternative screening programme set‐ups. Focus was on colorectal cancer screening and breast cancer screening. The alternative programmes varied with respect to number of tests performed, risk reduction obtained, probability of a false positive outcome and extent of co‐payment. Stated preferences were analysed using discrete ranking modelling and the relative weighting of the programme attributes identified. Applying discrete choice methods to elicit preferences within this area of health care seems justified by the face validity of the results. The signs of the coefficients are in accordance with a priori hypotheses. This paper suggests that large‐scale surveys focusing on individuals' preferences for cancer screening programmes may contribute significantly to the quality of economic evaluations within this field of health care. Copyright © 2001 John Wiley & Sons, Ltd.
Applying a team effectiveness framework to the performance of student case teams
Authors: Werner Jon M. , Lester Scott W.
Published: August 2002

This study predicted the performance of 107 student case teams from ten sections of a management class by using
a measure of team structure and four measures of team process. Satisfaction with the team was significantly and
positively related to team structure and three of the process variables. In contrast, although team structure and
team spirit were significantly and positively related to grade (on the case project), social support was
significantly but negatively related to grade. This article compares student teams and work teams and discusses
implications for organizational training and management education.
Managerial competency needs and training requests: The case of the Spanish tourist industry
Authors: Agut Sonia , Grau Rosa
Published: August 2002

There is some inconsistency between the theory and practice of the analysis of deficits in managerial
capabilities. Some academic literature suggests that the study of needs should be considered as gaps in
competencies (Bee and Bee, 1994; Peiró, 1999), but organizations actually analyze needs as training preferences (Ford and
Noe, 1987; Guthrie and Schwoerer, 1994, 1996; Tharenou, 1991).

The aim of this study is to analyze technical and generic managerial competency needs and managerial training
requests in order to conclude which method provides more accurate information on the real deficits in managerial
capabilities. The sample was made up of eighty managers from hotels and restaurants in the Valencian Community on
the Mediterranean coast of Spain.

The results show, on the one hand, the existence of technical competency needs in many topics or areas of
knowledge (for example, economic‐financial management, marketing and market analysis) and also in
generic competencies (such as control of hasty reactions in highly emotive situations). However,
managers request additional training only in technical aspects, such as information technology and languages, but
not in generic aspects. In any case, both methods could be considered complementary. The authors discuss
implications and limitations of the study as well as directions for future research.
Self‐Monitoring and Performance Appraisal Satisfaction: An Exploratory Field Study
Authors: Miller Janice S.
Published: August 2002

Members of 12 project teams in five organizations participated in a study that assessed their
self‐monitoring characteristics and level of satisfaction with their performance appraisal system. Overall,
taking part in self‐ratings and upward appraisals of team leaders was associated with greater levels of
appraisal satisfaction than was participating in peer evaluations. Self‐monitoring level was negatively
associated with appraisal satisfaction after controlling for level of ratings generated by peers, self, and
leader. The paper discusses results, and offers practical implications in light of the social and interpersonal
context that surrounds performance evaluation. © 2001 John Wiley & Sons, Inc.
Water budget and surface‐layer water storage in a Sphagnum bog in central Sweden
Authors: Kellner Erik , Halldin Sven
Published: August 2002

A water budget was established for the open, undisturbed bog Stormossen, central Sweden, for the growing seasons of 1996 and 1997 as a part of the NOPEX project. The water budget was complemented with data on the spatial variation of groundwater levels and water contents in different microrelief elements (ridge, hollow and ridge margin). The seasonal (24 May to 4 October) rainfall, evaporation and runoff were 200, 256, and 43 mm in 1996, respectively, and 310, 286 and 74 mm in 1997, giving negative budgets of −99 mm in 1996 and −50 mm in 1997. Approximately 60% of the total budget was caused by storage changes in the upper 40 cm of the bog and 40% by swelling/shrinking in the layers below. This ‘mire breathing’ must be incorporated in future models of mire‐water dynamics. The water content varied diversely among the different microrelief elements, much depending on the properties of moss and peat together with distance to water table. There also was a strong hysteresis in the relationships between groundwater level and measured volumetric water content, depending partly on pore‐throat effects and partly on swelling/shrinking of the peat matrix. A seasonal variation of volumetric water content in a layer beneath water table was found to be larger than what could be justified by compression alone. We think that probable causes could be methane gas expansion together with temperature effects. The main conclusions of this study were: (i) water‐transport and storage characteristics are distinctly different among hummocks, ridges and hollows, (ii) mire wetness cannot be deduced from groundwater levels only, and (iii) an important part of the total water storage was caused by swelling/shrinking of the peat, not by changes in unsaturated water content. Copyright © 2002 John Wiley & Sons, Ltd.
A hydrological model dedicated to topography‐based simulation of nitrogen transfer and transformation: rationale and application to the geomorphology– denitrification relationship
Authors: Beaujouan Véronique , Durand Patrick , Ruiz Laurent , Aurousseau Pierre , Cotteret Gilles
Published: August 2002

A new integrated hydrological and nitrogen model, called TNT2 (topography‐based nitrogen transfer and transformation), has been developed to study nitrogen fluxes in small catchments. This model, process‐based and spatially distributed in order to take spatial interactions into account, has been kept as simple as possible. Here, only the hydrological module is discussed. The two main hypotheses of the hydrological model are taken from the TOPMODEL concept (constant hydraulic gradient equal to slope and hydraulic conductivity decreasing exponentially with depth). The model is based on a daily water balance for each cell of a regular square grid and computes an explicit cell‐to‐cell routing. Transfer through the vadose zone is simulated using a conceptual, layer‐based algorithm analogous to the Burns model, except that a drainage water reservoir has been added to simulate mobile/immobile water processes and variations of the water table within the soil. The crop growth and nitrogen transformations are simulated using the equations of a generic plant‐soil model, STICS. As an example, a preliminary study of the effect of the catchment geomorphology on denitrification is presented. The study was performed on theoretical catchments with contrasted slope shapes and pathway patterns. Results show that the whole‐catchment denitrification depends on catchment geomorphology, although not directly through the extent of saturated areas. It is concluded that TNT2 seems to be a powerful tool to explore catchment processes, both by application to actual cases and by exploration on simple scenarios. Copyright © 2002 John Wiley & Sons, Ltd.
A GIS‐based hillslope erosion and sediment delivery model and its application in the Cerro Grande burn area
Authors: Wilson Cathy J. , Carey J. William , Beeson Peter C. , Gard Marvin O. , Lane Leonard J.
Published: August 2002

An Erratum has been published for this article in Hydrological Processes 16(5) 2002, 1130–1130.

A profile‐based, analytical hillslope erosion model (HEM) is integrated into a geographical information system (GIS) framework to provide a tool to assess the impact of the Cerro Grande fire on erosion and sediment delivery to the many streams draining the burn area. The model, HEM–GIS, calculates rill and interrill erosion, transport and deposition along digital flow‐pathways generated with GIS software. This new erosion and sediment yield technology accounts for complex terrain attributes and their impact on the connectivity of sediment transport pathways from source areas to streams. GIS digital spatial data, including elevation, vegetation cover, burn severity and soil type, are used as input to the model. Output includes spatially distributed predictions of total event‐based sediment yield (tonnes or kilograms per square metre). Here the model is applied across an 800 km2 region of the Pajarito Plateau watershed to assess the sedimentation risks associated with a 100 year design rain event. Although unvalidated for the design storm, the model predicts that the fire may cause runoff to increase by three to six times, and sediment yield to increase by more than an order of magnitude. Published in 2001 John Wiley & Sons, Ltd.
Macroporosity and infiltration in blanket peat: the implications of tension disc infiltrometer measurements
Authors: Holden J. , Burt T. P. , Cox N. J.
Published: August 2002

Little is known about the processes of infiltration and water movement in the upper layers of blanket peat. A tension infiltrometer was used to measure hydraulic conductivity in a blanket peat in the North Pennines, England. Measurements were taken from the surface down to 20 cm in depth for peat under four different vegetation covers. It was found that macropore flow is a significant pathway for water in the upper layers of this soil type. It was also found that peat depth and surface vegetation cover were associated with macroporosity and saturated hydraulic conductivity. The proportion of macropore flow was found to be greater at 5 cm depth than at 0, 10 and 20 cm depth. Peat beneath a Sphagnum cover tends to be more permeable and a greater proportion of macropore flow can occur beneath this vegetation type. Functional macroporosity and matrix flow in the near‐surface layers of bare peat appear to have been affected by weathering processes. Comparision of results with rainfall records demonstrates that infiltration‐excess overland flow is unlikely to be a common runoff‐generating mechanism on blanket peat; rather, a saturation‐excess mechanism combined with percolation‐excess above much less permeable layers dominates the runoff response. Copyright © 2001 John Wiley & Sons, Ltd.
Evaluation of cytokeratin‐19 mRNA as a tumor marker in the peripheral blood of nasopharyngeal carcinoma patients receiving concurrent chemoradiotherapy
Authors: Lin Jin‐Ching , Chen Kuang Y. , Wang Wen‐Yi , Jan Jian‐Sheng , Liang Wen‐Miin , Wei Yau‐Huei
Published: August 2002

The reverse transcriptase‐polymerase chain reaction (RT‐PCR) technique is a tool capable of detecting minute quantities of circulating tumor cell‐derived transcripts. Nasopharyngeal carcinoma (NPC) is a rapidly growing tumor of epithelial origin and high metastatic potential. The aim of our study is to investigate the clinical value of circulating cytokeratin‐19 (CK‐19) mRNA detection in NPC patients. Between June 1997 and March 1999, 57 previously untreated, advanced NPC patients without distant metastasis were uniformly treated by concurrent chemoradiotherapy. Peripheral blood samples were collected prospectively before treatment and subjected to a nested RT‐PCR assay. Measures were taken to prevent contamination and pseudogene interference. PCR products of positive results were verified by restriction enzyme Hae II and direct sequencing. Under our nested RT‐PCR experimental conditions, 33.3% (19/57) clinically nonmetastatic NPC patients had CK‐19 mRNA in their blood. The positive detection rates of CK‐19 mRNA in the peripheral blood for different stages were 20.0% for stage II, 31.6% stage III and 43.5% stage IV (p = 0.1335). After a median follow‐up time of 35 months, 2 patients had recurrences of their primary tumors and 14 developed distant metastases without locoregional recurrence. Nine of 19 (47.4%) CK‐19 mRNA‐positive patients and 5 of 38 (13.2%) CK‐19 mRNA‐negative patients developed distant metastasis (p = 0.00826). The 3‐year metastasis‐free survival rates were 49.9% for patients with detectable CK‐19 and 85.9% for those with undetectable CK‐19 (p = 0.0089, log‐rank test). Our data suggest that the presence of CK‐19 mRNA in the peripheral blood may be a potential marker of micrometastasis for NPC. © 2001 Wiley‐Liss, Inc.
Ionizing radiation as a response‐enhancing agent for CD95‐mediated apoptosis
Authors: Sheard Michael A.
Published: August 2002

CD95 (Fas/APO‐1) is a death receptor on the surface of a wide variety of cell types. In most cells examined, ionizing radiation acts as a response‐enhancing agent for CD95‐mediated cell death. Although DNA‐damaging radiation appears to modulate CD95‐mediated signals through multiple mechanisms, the only well‐characterized mechanism is activation of the tumor‐suppressor protein p53, which transcriptionally regulates the expression of CD95 on various cell types. The ligand for CD95 is expressed by activated lymphocytes and natural‐killer cells, which produce factors that sensitize cells resistant to CD95‐mediated cell death. Ligation of CD95 on irradiated tumor cells might be achievable using emerging modalities that reactivate the stalled anti‐tumor immune response. © 2001 Wiley‐Liss, Inc.
Effects of N‐acetylcysteine in an esophageal carcinogenesis model in rats treated with diethylnitrosamine and diethyldithiocarbamate
Authors: Balansky Roumen M. , Ganchev Gancho , D'Agostini Francesco , De Flora Silvio
Published: August 2002

Due to the increasing role of esophageal tumors in human cancer pathology, there is need for animal models evaluating the mechanisms of esophageal carcinogenesis and investigating protective factors toward this disease. Several N‐nitrosamines have been shown to induce esophageal tumors in rats. We designed a study in BD6 rats treated with N‐diethylnitrosamine (DEN) according to a simple protocol involving weekly i.p. injections of this carcinogen for 8 consecutive weeks. This treatment resulted in a high incidence and multiplicity of liver tumors and in occurrence of preneoplastic lesions and papillomas in the esophagus. Intraperitoneal injections of diethyldithiocarbamate (DEDTC), 4 hr after each DEN injection, i.e., during the period of DEN metabolization, improved survival of rats and did not affect the liver tumor yield but doubled the incidence of esophageal tumors and enhanced 4.9× their multiplicity. Moreover, 15% of rats developed esophageal squamocellular carcinomas. The oral administration of the thiol N‐acetyl‐L‐cysteine (NAC), a precursor and analogue of reduced glutathione, to rats treated with the DEN/DEDTC combination did not change the liver tumor yield but attenuated esophageal carcinogenesis by producing a significant shift of preneoplastic lesions to milder forms as well as a significant decrease of tumor multiplicity. Therefore, the DEN/DEDTC protocol appears to provide an interesting 2‐organ model of N‐nitrosamine‐induced carcinogenesis in rats, in which NAC is moderately effective as an inhibitor. The mechanisms underlying enhancement of DEN‐induced esophageal carcinogenesis by DEDTC and the protective effects of NAC are discussed. © 2002 Wiley‐Liss, Inc.
Insulin‐like growth factor‐I has a biphasic effect on colon carcinoma cells through transient inactivation of forkhead1, initially mitogenic, then mediating growth arrest and differentiation
Authors: Ewton Daina Z. , Kansra Sanjay , Lim Seunghwan , Friedman Eileen
Published: August 2002

IGF‐I stimulates intestinal cell differentiation after initiating a short proliferative burst, similar to its effect on muscle cell differentiation. Levels of IGF‐I attainable in serum (10–20 ng/ml) induced transient growth stimulation of colon carcinoma cells, then growth arrest. When IGF‐I functioned as a mitogen, it blocked differentiation. Intestinal cell differentiation occurred once cells had undergone the IGF‐I–initiated growth arrest and IGF‐I and butyrate acted synergistically to induce maturation markers. IGF‐I induces NIH‐3T3 cell proliferation and survival by activating the kinase akt, which in turn inhibits various apoptotic mediators and the forkhead family of transcription factors, which mediate expression of p27kip1. Promoter reporter assays demonstrated that forkhead1 mediates transcription of p27kip1 in colon carcinoma cells. The mitogenic effects of IGF‐I on 4 colon carcinoma cell lines were transient because the inactivating phosphorylation of forkhead1 by akt was short‐lived. This allowed transcriptional upregulation of the cdk inhibitor p27kip1, with a resulting growth arrest. In contrast, in NIH‐3T3 cells treated in parallel with identical IGF‐I levels, forkhead phosphorylation levels were sustained; thus, no increase in p27kip1 levels was seen and cells continued to proliferate. Intestinal epithelial cells in vivo undergo a limited number of divisions, then growth arrest and completion of their maturation. IGFs found in intestinal tissue may control the timing of this process. In addition, colon cancers may have developed strategies to overcome IGF‐I–mediated growth arrest. Earlier (Kansra et al., Int J Cancer 2000;87:373–8), we found that levels of IGFBP‐3 were elevated at least 2‐fold in 70% of resected colon cancers compared with adjacent normal tissue. In the current study, growth inhibition by IGF‐I and IGF‐II was blocked by concurrent addition of IGFBP‐3, implying that colon cancers with elevated IGFBP‐3 levels would be selected for in vivo because they could bind and inactivate high serum IGF‐I levels and continue to proliferate. © 2002 Wiley‐Liss, Inc.
Peripheral γδ T‐cell deficit in nasopharyngeal carcinoma
Authors: Zheng Bo Jian , Ng Sze Park , Chua Daniel T.T. , Sham Jonathan S.T. , Kwong Dora L.W. , Lam Clarence K. , Ng Mun Hon
Published: August 2002

Previous studies identified CD56+ and CD56− subsets of peripheral γδ T cells from healthy donors. Both subsets responded to stimulation by a myeloma cell line, XG‐7 and undergo vigorous ex vivo expansion in the presence of exogenous IL‐2. They are cytotoxic for different tumor targets including nasopharyngeal carcinoma, but they differ from one another in that the CD56− subset has an additional growth requirement for IL‐7 and exhibited greater cytotoxicity against nasopharyngeal carcinoma (NPC) targets. These immune cells were further shown to retard tumor growth in a nude mice NPC model. To assess if these immune cells might contribute to host defense against NPC, we compared γδ T‐cell status of NPC patients with healthy donors and survivors who had been in clinical remission of the cancer. It was found that peripheral γδ T cells of patients were impaired in their response to the stimulatory effects of XG‐7 and exhibited weak or essentially no cytotoxicity for the NPC targets. The deficits were present in early and advanced stages of the cancer but were restored among survivors after successful treatment of the cancer. These findings support a role for peripheral γδ T cells in host defense against NPC. It was noted that these immune cells comprise less than 5% of peripheral blood monocytic cells and hence it was not surprising that this component of host defense was breached early in the development of the cancer. © 2002 Wiley‐Liss, Inc.
Mapping of two new epitopes on the apomucin encoded by MUC5AC gene: Expression in normal GI tract and colon tumors
Authors: Nollet Séverine , Forgue‐Lafitte Marie‐Elisabeth , Kirkham Paul , Bara Jacques
Published: August 2002

Three hybridomas secreting monoclonal antibodies (MAbs) against human (62M MAb) or rat (463M and 589M MAbs) gastric mucins were isolated. These MAbs immunoreacted against a human recombinant protein encoded by the 3′ region of the MUC5AC gene. We have mapped 2 new gastric mucin epitopes and the M1‐f epitope previously characterized by the 19/21M1 MAbs on MUC5AC‐encoded apomucin. The M1‐f, 463/589M and 62M epitopes are located in the MUC11p15/von Willebrand factor (vWF)‐A3uD4 domain, in the D4‐(vWF)‐like domain and in the C‐ and CK‐vWF‐like domains of MUC5AC, respectively. The 463/589M and 62M MAbs stained the surface epithelium of human gastric mucosae, but not the normal colon mucosae (except 463/589M MAbs, which immunoreacted with 5 of 49 cases). All hyperplastic polyps are stained strongly with the 463/589M MAbs and faintly with the 62M MAb. In addition, 463/589M epitope was detected in 64% of the adenomas and in 93% of the mucosae adjacent to adenocarcinomas; in contrast, only 9% of the adenomas and 29% of the mucosae adjacent to adenocarcinomas expressed the 62M epitope. The expression pattern of the 463/589M epitope in colonic carcinogenesis is different from that of the 19/21M1 epitope, although the 2 epitopes are encoded by MUC5AC gene. © 2002 Wiley‐Liss, Inc.
Chemotherapeutic agents sensitize osteogenic sarcoma cells, but not normal human bone cells, to apo2l/trail‐induced apoptosis
Authors: Evdokiou Andreas , Bouralexis Stelios , Atkins Gerald J. , Chai Fugui , Hay Shelley , Clayer Mark , Findlay David M.
Published: August 2002

Apo2L/TRAIL is a member of the tumor necrosis factor (TNF) family of cytokines that induces death of cancer cells but not normal cells. Its potent apoptotic activity is mediated through its cell surface death domain‐containing receptors, DR4 and DR5. Apo2L/TRAIL interacts also with 3 “decoy” receptors that do not induce apoptosis, DcR1, DcR2, which lack functional death domains, and osteoprotegerin (OPG). The aim of our study was to investigate the cytotoxic activity of Apo2L/TRAIL on established osteogenic sarcoma cell lines (BTK‐143, HOS, MG‐63, SJSA‐1, G‐292 and SAOS2) and in primary cultures of normal human bone (NHB) cells. When used alone, Apo2L/TRAIL at 100 ng/ml for 24 hr induced greater than 80% cell death in only 1 (BTK‐143) of the 6 osteogenic sarcoma cell lines. In contrast, Apo2L/TRAIL‐resistant cells were susceptible to Apo2L/TRAIL‐mediated apoptosis in the presence of the anticancer drugs, Doxorubicin (DOX), Cisplatin (CDDP) and Etoposide (ETP) but not Methotrexate (MTX) or Cyclophosphamide (CPM). Importantly, neither Apo2L/TRAIL alone nor in combination with any of these drugs affected primary normal human bone cells under equivalent conditions. Apo2L/TRAIL‐induced apoptosis, and its augmentation by chemotherapy in the resistant cell lines was mediated through caspase‐8 and caspase‐3 activation. Furthermore, Apo2L/TRAIL‐induced apoptosis and its augmentation by chemotherapy was effectively inhibited by caspase‐8 zIETD‐fmk and caspase‐3 zDEVD‐fmk protease inhibitors and by the pan‐caspase inhibitor zVAD‐fmk. The pattern of basal Apo2L/TRAIL receptor mRNA expression, or expression of the intracellular caspase inhibitor FLICE‐inhibitory protein, FLIP, could not be readily correlated with resistance or sensitivity to Apo2L/TRAIL‐induced apoptosis. However, the augmentation of Apo2L/TRAIL effects by chemotherapy was associated with drug‐induced up‐regulation of death receptors DR4 and DR5 mRNA and protein. No obvious correlation was seen between the expression of OPG mRNA or protein and susceptibility of cells to Apo2L/TRAIL‐induced apoptosis. Stable over‐expression of a dominant negative form of the Fas‐associated death domain protein (FADD) in the Apo2L/TRAIL‐sensitive BTK‐143 cells completely inhibited Apo2L/TRAIL‐induced cell death. Our results indicate that chemotherapy and Apo2L/TRAIL act synergistically to kill cancer cells but not normal bone‐derived osteoblast‐like cells, which has implications for future therapy of osteosarcoma. © 2002 Wiley‐Liss, Inc.
Cleavage and polyadenylation specificity factor (CPSF)‐derived peptides can induce HLA‐A2‐restricted and tumor‐specific CTLs in the majority of gastrointestinal cancer patients
Authors: Maeda Yoshiaki , Ito Masaaki , Harashima Nanae , Nakatsura Tetsuya , Hida Naoya , Imai Nobue , Sato Yuuji , Shichijo Shigeki , Todo Satoru , Itoh Kyogo
Published: August 2002

To identify CTL‐directed antigens in gastrointestinal cancer, we have investigated antigens recognized by the HLA‐A2‐restricted CTL line established from T cells infiltrating into colon cancer and report herein cleavage and polyadenylation specificity factor (CPSF) as a potent antigen holding peptides capable of inducing CTLs. Five peptides at amino acid positions 250–258, 392–400, 534–542, 1296–1304 and 1359–1368 of CPSF, which were recognized by the CTL line, were found to have the ability to induce HLA‐A2‐restricted and tumor‐specific CTLs in peripheral blood mononuclear cells of the majority (69%, 11/16) of gastrointestinal cancer patients with different HLA‐A2 subtypes. Thus, these peptides might be appropriate molecules for use in the peptide‐based specific immunotherapy of HLA‐A2+ patients with gastrointestinal cancers. © 2002 Wiley‐Liss, Inc.
A variant of the DNA repair gene XRCC3 and risk of squamous cell carcinoma of the head and neck: A case‐control analysis
Authors: Shen Hongbing , Sturgis Erich M. , Dahlstrom Kristina R. , Zheng Yuxin , Spitz Margaret R. , Wei Qingyi
Published: August 2002

Individuals differ in their ability to repair DNA damage induced by carcinogens. Studies have shown that polymorphisms in DNA repair genes contribute to individual variation in DNA repair capacity and cancer risk. In a hospital‐based case‐control study, we tested the hypothesis that a C to T variant (Thr241Met) of DNA repair gene X‐ray repair cross‐complementing group 3 (XRCC3) is associated with risk of developing squamous cell carcinoma of the head and neck (SCCHN). We genotyped for this variant in 367 non‐Hispanic white patients newly diagnosed with SCCHN and 354 frequency‐matched cancer‐free controls. Compared with the XRCC3 18067CC and 18607CT genotypes, the variant XRCC3 18067TT genotype was associated with a non‐statistically significantly increased risk of SCCHN (adjusted odds ratio [ORadj], 1.36; 95% confidence interval [CI], 0.89–2.08), but this risk was significantly increased among female subjects (ORadj 2.23, 95% CI, 1.00–4.98) and current smokers (ORadj, 2.26; 95% CI, 1.02–4.99). These findings suggest that the variant XRCC3 18067TT genotype may not play a major role in the etiology of SCCHN but may contribute to a subset of SCCHN. Larger studies are needed to verify these findings. © 2002 Wiley‐Liss, Inc.
Time trends incidence of both major histologic types of esophageal carcinomas in selected countries, 1973–1995
Authors: Vizcaino A. Paloma , Moreno Victor , Lambert Rene , Parkin D. Maxwell
Published: August 2002

The purpose of our study was to examine the incidence patterns of 2 major histologic types of esophageal cancer, in selected countries world‐wide and to identify components of birth cohort, period and age as determinants of observed time trends using regression modeling. The roles of temporal changes in specification of histology of tumors and of classification of cancers at the gastroesophageal junction as esophageal or gastric in origin were taken into consideration. In all, 56,426 esophageal cancer cases were included. The results indicate that the incidence rate of squamous cell carcinoma of the esophagus has been relatively stable in most of the countries analyzed, although increasing trends were observed in Denmark and the Netherlands (Eindhoven) among men and in Canada, Scotland and Switzerland among women. There was a significant increase in the incidence of esophageal adenocarcinomas in both sexes in the United States (among whites and blacks), Canada and South Australia and in 6 European countries (Scotland, Denmark, Iceland, Finland, Sweden and Norway). In France the increase was limited to men and in Switzerland the increase was observed only in women. Modeling was unable to distinguish which trends were the results of changes in risk between generations (as cohort effects), or changes in all age groups simultaneously (as a period effect). © 2002 Wiley‐Liss, Inc.
Y‐box factor YB‐1 predicts drug resistance and patient outcome in breast cancer independent of clinically relevant tumor biologic factors HER2, uPA and PAI‐1
Authors: Janz Martin , Harbeck Nadia , Dettmar Peer , Berger Ursula , Schmidt Anja , Jürchott Karsten , Schmitt Manfred , Royer Hans‐Dieter
Published: August 2002

Intrinsic or acquired resistance to chemotherapy is responsible for failure of current treatment regimens in breast cancer patients. The Y‐box protein YB‐1 regulates expression of the P‐glycoprotein gene mdr1, which plays a major role in the development of a multidrug‐resistant tumor phenotype. In human breast cancer, overexpression and nuclear localization of YB‐1 is associated with upregulation of P‐glycoprotein. In our pilot study, we analyzed the clinical relevance of YB‐1 expression in breast cancer (n = 83) after a median follow‐up of 61 months and compared it with tumor‐biologic factors already used for clinical risk‐group discrimination, i.e., HER2, urokinase‐type plasminogen activator (uPA) and plasminogen activator inhibitor type 1 (PAI‐1). High YB‐1 expression in tumor tissue and surrounding benign breast epithelial cells was significantly associated with poor patient outcome. In patients who received postoperative chemotherapy, the 5‐year relapse rate was 66% in patients with high YB‐1 expression. In contrast, in patients with low YB‐1 expressions, no relapse has been observed so far. YB‐1 expression thus indicates clinical drug resistance in breast cancer. Moreover, YB‐1 correlates with breast cancer aggressiveness: in patients not treated with postoperative chemotherapy, those with low YB‐1 expression are still free of disease, whereas the 5‐year relapse rate in those with high YB‐1 was 30%. There was no significant correlation between YB‐1 expression and either HER2 expression or uPA and PAI‐1 levels. Risk‐group assessment achieved by YB‐1 differed significantly from that by HER2 or uPA/PAI‐1. In conclusion, YB‐1 demonstrated prognostic and predictive significance in breast cancer by identifying high‐risk patients in both the presence and absence of postoperative chemotherapy, independent of tumor‐biologic factors currently available for clinical decision making. © 2001 Wiley‐Liss, Inc.
Why is the business‐cycle behaviour of fundamentals alike across exchange‐rate regimes?
Authors: Dedola Luca , Leduc Sylvain
Published: August 2002

Since the adoption of flexible exchange rates, real exchange rates have been much more volatile than they were under Bretton Woods. However, the volatilities of most other macroeconomic variables have remained approximately unchanged. This poses a puzzle for standard international business cycle models. This paper develops a two‐country, two‐sector model with nominal rigidities featuring deviations from the law of one price due to firms setting prices in buyers' currencies. By partially insulating goods markets across countries and thus mitigating the international expenditure‐switching effect, this pricing behaviour is found to considerably dampen the responses of quantities to shocks hitting the economies therefore helping to account for the puzzle. Copyright © 2001 John Wiley & Sons, Ltd.
Parametric and semiparametric estimation of sample selection models: an empirical application to the female labour force in Portugal
Authors: Martins Maria Fraga O.
Published: August 2002

This paper applies both parametric and semiparametric methods to the estimation of wage and participation equations for married women in Portugal. The semiparametric estimators considered are the two‐stage estimators proposed by Newey (1991) and Andrews and Schafgans (1998). The selection equation results are compared using the specification tests proposed by Horowitz (1993), Horowitz and Härdle (1994), and the wage equation results are compared using a Hausman test. Significant differences between the two approaches indicate the inappropriateness of the standard parametric methods to the estimation of the model and for the purpose of policy simulations. The greater departure seems to occur in the range of the low values of the index corresponding to a specific group of women. Copyright © 2001 John Wiley & Sons, Ltd.
Polarized light scattering as a rapid and sensitive assay for metal toxicity to bacteria
Authors: Bronk B. V. , Li Z. Z. , Czégé Jozsef
Published: August 2002

A new method that utilizes the scattering of polarized light from a suspension of bacteria to assay the effect of toxins is evaluated. The method compares the time dependence of changes in an angular scattering pattern obtained from a suspension of Escherichia coli bacteria with no toxin exposure to the corresponding, but reduced, changes that occur when there is exposure to a small concentration of certain toxicants. The changes are due to growth of a specially prepared population of these bacteria. The changes in the pattern normally reflect a change in average bacterial size due to growth, whereas the reduction of the change in pattern occurs when there is rapid cessation of bacterial growth. The method was tested with varying concentrations of the ions of five different heavy metals. The results using this method during the first few minutes after exposure to the toxicant were compared to the relative survival of colony‐forming units of the bacteria. The graphs for the two methods were found to be approximately parallel for each of the five metals examined. This result indicates that the toxic effect of these metals takes place relatively quickly for these bacteria. These results were compared with results available from the literature for the same metals but using other methods for measuring the toxicity to bacteria. Published in 2001 by John Wiley & Sons Ltd.
Effects of trivalent chromium on hepatic CYP‐linked monooxygenases in laying hens
Authors: Guerra M. C. , Renzulli C. , Antelli A. , Pozzetti L. , Paolini M. , Speroni E.
Published: August 2002

Chromium is an essential nutrient required for the metabolism of carbohydrates and lipids in humans and many animal species. We evaluated whether feeding laying hens with high levels of different chemical forms of trivalent chromium may affect hepatic metabolizing cytochrome P‐450 (CYP)‐linked enzymes. Modulation of CYP‐dependent monooxygenases (which play a pivotal role in the endogenous metabolism) by Cr(III) was tested using either specific substrates as probes of different CYPs or testosterone as a multi‐bioprobe. The CYP‐supported oxidases were studied in liver microsomes from laying hens fed with diet supplemented with either 25 or 50 ppm chromium chloride as a yeast or as aminoniacinate. Although at 25 ppm no appreciable effects were observed, at 50 ppm a general inactivation of the recorded monooxygenases (ranging from 34% loss for ethoxycoumarin O‐deethylase with chromium chloride to 85% loss for O‐deethylation of ethoxyresorufin with either chromium yeast or aminoniacinate) were achieved in the supplemented groups vs controls. The only exception was the O‐dealkylation of pentoxyresorufin, which was significantly boosted by both chromium yeast (up to 65% increase) and chromium aminoniacinate (up to 141%). Measurements of the regio‐ and stereoselective hydroxylation of testosterone used as a multi‐bioprobe corroborated the inactivating properties of Cr(III) at the higher dose. Taken as a whole, these findings seem to indicate that high levels of Cr(III) supplementation can substantially impair CYP‐catalysed drug metabolism in laying hens. Copyright © 2002 John Wiley & Sons, Ltd.
Characterization of angiogenesis and inflammation surrounding ePTFE implanted on the epicardium
Authors: Kellar Robert S. , Kleinert Leigh B. , Williams Stuart K.
Published: August 2002

The response of epicardial tissue to the implantation of expanded polytetrafluoroethylene (ePTFE) was evaluated and compared with identical material implanted within subcutaneous and adipose tissues. These two tissue environments were selected for comparison with epicardial implants because they represent tissue often involved in device implantation. Discs of ePTFE (6 mm) were implanted into three different tissue sites in Sprague‐Dawley rats. At 5 weeks, polymers and surrounding tissues were harvested and processed for light microscopy. General histology and histochemistry data indicated all polymers to be well incorporated with new tissue. Subcutaneous implants were covered by a dense fibrous capsule (55–70 μm). Epicardial and adipose implants had no fibrous capsule and a significantly greater number of microvessels (arterioles, capillaries, and venules) within the surrounding tissues compared with subcutaneous implants. An increased level of inflammation was also observed around epicardial implants compared with the other implants. Additionally, the new vasculature surrounding epicardially implanted ePTFE revealed an altered microvessel density and vessel type distribution compared with normal (control) epicardium. These results suggest that epicardial tissue responds to implanted ePTFE with a robust inflammatory response that may support the formation of a new microvasculature that is uniquely different from the native epicardial microvasculature. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res 61: 226–233, 2002
Bonelike apatite growth on hydroxyapatite–gelatin sponges from simulated body fluid
Authors: Bigi A. , Boanini E. , Panzavolta S. , Roveri N. , Rubini K.
Published: August 2002

In vitro bioactivity of gelatin sponges and hydroxyapatite‐enriched gelatin sponges was tested through evaluation of the variations in their composition and morphology after soaking in simulated body fluid (1.5) for periods up to 21 days at 37°C. The presence of hydroxyapatite inside the sponges promotes the deposition of bonelike apatite crystals. The deposits are laid down as spherical aggregates, with mean diameters increasing from about 1–2 μm, after 4 days of soaking in simulated body fluid solution, up to about 3.5 μm in the samples soaked for 21 days. Simultaneously, the relative amount of inorganic phase increases up to about 56% wt, leading to a composite material with a composition quite close to that of bone tissue. The inorganic phase is a poor crystalline carbonated apatite similar to trabecular bone apatite. © 2001 Wiley Periodicals, Inc. J Biomed Mater Res 59: 709–714, 2002
Smooth muscle cell adhesion on crosslinked hyaluronan gels
Authors: Ramamurthi Anand , Vesely Ivan
Published: August 2002

Hyaluronic acid (HA)‐based polymers (hylans) are highly biocompatible and can be structurally modified to obtain desired mechanical properties. This study evaluated divinyl sulfone‐crosslinked solid and particulate hylans as cellular scaffolds. These two hylan types differ in surface characteristics, mode of preparation, HA content, and extent of crosslinking. Neonatal rat aortic smooth muscle cells were cultured on hylan gels coated with matrix factors including collagen I, ECM gel, laminin, and fibronectin and on uncoated controls for ≤4 weeks. Cell attachment was sparse on uncoated controls but significantly enhanced on coated gels. Cell morphology was influenced by the identity of the matrix factors coated and the surface topography of the hylan gels. Cells attached to coated particulate gels appeared either highly spread (collagen, fibronectin) or irregularly shaped (ECM gel, laminin). Cells on laminin and fibronectin‐coated solid gels were rounded and nonproliferative. Cells proliferated most rapidly on ECM gel‐coated gels. The uneven surface of particulate gels induced more protein deposition and the subsequent attachment and active proliferation of cells. This study shows that surface texturizing and subsequent surface treatment with matrix factors enhances cell attachment and proliferation of hylans. These results are useful toward developing bioengineered materials based on cell‐hylan composites. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res 60: 196–205, 2002
Resorbable polymer fibers for ligament augmentation
Authors: Dürselen Lutz , Dauner Martin , Hierlemann Helmut , Planck Heinrich , Claes Lutz E. , Ignatius Anita
Published: August 2002

Resorbable augmentation devices for cruciate ligament surgery have been developed to temporarily protect healing tendon grafts or sutured ligaments against high tensile loads during the postoperative healing period. Materials available at present [e.g., polydioxanone (PDS)] show a half‐life tensile strength of only 4–6 weeks, whereas the process of revitalization and recovering of the transplanted tendon graft can take up to 12 months. Therefore, a device that provides gradually decreasing mechanical properties with a half‐time strength of at least 6 months would be desirable. In order to obtain a suitable material, we investigated the degradation kinetics of a variety of different resorbable fibers made of poly(L‐lactide) and poly(L‐lactide‐co‐glycolide). The fiber materials differed in processing and treatment parameters like thermal posttreatment, irradiation, and fiber diameter. The fibers were degraded in vitro and were tested for mechanical properties and molecular weight at various time points up to 72 weeks. The half‐time strength of the materials ranged between 5 and 64 weeks, depending on their treatment parameters. In contrast, the stiffness did not decrease adequately. However, an augmentation stiffness that does not change much versus time could not provide a gradual increase in graft load, which is important to stimulate the orientation of the collagenous tissue. Therefore, design of an augmentation construct braided out of more than one quickly degrading fiber materials is suggested. After the breakdown of the faster‐degrading fiber components the stiffness would automatically decrease by the diminution of the load‐carrying fiber volume. © 2001 John Wiley & Sons, Inc. J Biomed Mater Res (Appl Biomater) 58: 666–672, 2001
Experimental investigation of Poisson's ratio as a damage parameter for bone fatigue
Authors: Pidaparti R. M. , Vogt A.
Published: August 2002

The fatigue loading of bone results in the degradation of mechanical properties such as strength and stiffness. Even though several authors have investigated the relationship between the longitudinal modulus and loading cycles, the reduction in Poisson's ratio and its relationship to fatigue loading cycles have not previously been investigated. In this study, the reduction in the major Poisson's ratio and longitudinal modulus for cortical bone specimens as a result of tensile fatigue was experimentally investigated. We compared the results of the major Poisson's ratio reduction to the reduction in longitudinal modulus to determine if there was a relationship between the two. The results showed that the reduction in Poisson's ratio was about 8–22% higher than the reduction in longitudinal modulus, indicating that more microdamage accumulated transversely than longitudinally. Both the longitudinal modulus and major Poisson's ratio decreased in a logarithmic fashion with increasing loading cycles for the bone specimens tested. © 2001 Wiley Periodicals, Inc. J Biomed Mater Res 59: 282–287, 2002
Biomimetic calcium phosphate coatings on Polyactive® 1000/70/30
Authors: Du C. , Klasens P. , Haan R. E. , Bezemer J. , Cui F. Z. , de Groot K. , Layrolle P.
Published: August 2002

Precalcification of Polyactive® 1000/70/30 with a biomimetic calcium phosphate coating is expected to enhance the bioactivity of this biodegradable polymer for the application as bone filler or scaffold of bone tissue engineering. This study presents a 1‐day one‐step incubation method to obtain either amorphous or bone‐like apatitic calcium phosphate coating on Polyactive® 1000/70/30. Either dense plates or three‐dimensional porous blocks of the polymer were incubated in a simplified but concentrated simulated body fluid‐derived solution at 37°C. By bubbling CO2 gas, a solution was prepared with calcium and phosphate ion concentrations five times of that of regular simulated body fluid. With controlled stirring, the CO2 was released out of the solution and exchanged by air. The pH of the solution increased to induce coating formation. Adjusting stirring rate and CO2/air exchange rate controlled the process kinetics. The reaction kinetics had little influence on the crystallographic structure of the final coating mineral for a given solution composition as shown by Fourier transform infrared spectroscopy and X‐ray diffraction. However, the interface structure between the coating and substrate was kinetics‐dependent. A fast precipitation condition resulted in a uniform but superficial calcification pattern at the surface of polymer. A slow process by selecting either a slow stirring or a slow CO2/air exchange, on the contrary, induced a localized but deep inside calcification pattern. A tensile test showed no statistically significant difference in the mechanical properties among uncoated and coated polymers. The cracking behavior of coatings from different kinetics, however, exhibited different manners, as can be attributed to different interface structures and interfacial strengths. © 2001 Wiley Periodicals, Inc. J Biomed Mater Res 59: 535–546, 2002
Comparison of iron‐catalyzed DNA and lipid oxidation
Authors: Djuric Zora , Potter David W. , Taffe Bonita G. , Strasburg Gale M.
Published: August 2002

Lipid and DNA oxidation catalyzed by iron(II) were compared in HEPES and phosphate buffers. Lipid peroxidation was examined in a sensitive liposome system constructed with a fluorescent probe that allowed us to examine the effects of both low and high iron concentrations. With liposomes made from synthetic 1‐stearoyl‐2‐linoleoyl‐sn‐glycero‐3‐phosphocholine or from rat liver microsomal lipid, lipid peroxidation increased with iron concentration up to the range of 10–20 μM iron(II), but then rates decreased with further increases in iron concentration. This may be due to the limited amount of lipid peroxides available in liposomes for oxidation of iron(II) to generate equimolar iron(III), which is thought to be important for the initation of lipid peroxidation. Addition of hydrogen peroxide to incubations with 1–10 μM iron(II) decreased rates of lipid peroxidation, whereas addition of hydrogen peroxide to incubations with higher iron concentrations increased rates of lipid peroxidation. Thus, in this liposome system, sufficient peroxide from either within the lipid or from exogenous sources must be present to generate equimolar iron(II) and iron(III). With iron‐catalyzed DNA oxidation, hydrogen peroxide always stimulated product formation. Phosphate buffer, which chelates iron but still allows for generation of hydroxyl radicals, inhibited lipid peroxidation but not DNA oxidation. HEPES buffer, which scavenges hydroxyl radicals, inhibited DNA oxidation, whereas lipid peroxidation was unaffected since presumably iron(II) and iron(III) were still available for reaction with liposomes in HEPES buffer. © 2001 John Wiley & Sons, Inc. J Biochem Mol Toxicol 15:114–119, 2001