bluuebunny/crossref_metadata_2025_split huggingface dataset:
Expression of apoptosis regulators in cutaneous T‐cell lymphoma (CTCL) cells
Authors: Zhang Chun‐Lei , Kamarashev Jivko , Qin Jian‐Zhong , Burg Günter , Dummer Reinhard , Döbbeling Udo 
Published: May 2003

AbstractThis study examined cutaneous T‐cell lymphoma (CTCL) cell lines and cutaneous lesions for the presence of Bcl‐2 gene family members and found that the two apoptosis‐inhibiting members Bcl‐xL and Mcl‐1 and the two apoptosis‐supporting members Bad and Bax were expressed. However, Bad was at least partially inactivated by phosphorylation. In skin lesions, the translocation of Bad from the nucleus to the cytoplasm may reflect the Bad inactivation by phosphorylation identified in vivo. Bax is also ineffective, as the non‐steroidal anti‐inflammatory drug sulindac, whose cytotoxic effect is mediated by Bax, could not induce apoptosis in CTCL cell lines. The expression of Bcl‐2, Bcl‐xL, and Mcl‐1 may therefore be sufficient to guarantee the survival of malignant CTCL cells. The Bcl‐x, Mcl‐1, Bad, and Bax proteins were also expressed in all CTCL skin lesions tested. In two patients from whom two biopsies from two different time points of the disease were available, a significant increase in Mcl‐1 expression was found in the later‐stage skin lesion. Overexpression of Mcl‐1 and synthesis of non‐functional Bax may be responsible for the resistance of CTCL cells to the anti‐cancer drugs chlorambucil and sulindac. Copyright © 2003 John Wiley & Sons, Ltd.
β‐Catenin mutations in pulmonary blastomas: association with morule formation
Authors: Sekine Shigeki , Shibata Tatsuhiro , Matsuno Yoshihiro , Maeshima Arafumi , Ishii Genichiro , Sakamoto Michiie , Hirohashi Setsuo 
Published: May 2003

AbstractTo elucidate the contribution of β‐catenin gene mutation to the development of pulmonary blastomas, we analysed mutations in three well‐differentiated fetal adenocarcinomas (WDFAs) and six biphasic pulmonary blastomas (BPBs). For comparison, eight clear‐cell adenocarcinomas with fetal lung features were also examined. β‐Catenin gene mutations were found in all three WDFAs, two BPBs, and none of the clear‐cell adenocarcinomas with fetal lung features. All tumours with mutations had a common histological feature, namely morule formation, and showed a characteristic heterogeneous β‐catenin expression pattern that was revealed by immunohistochemistry. Strong nuclear/cytoplasmic expression of β‐catenin was seen in clustered cells in the morular areas and in single cells in glands, and was associated with neuroendocrine differentiation. As β‐catenin mutations are rare among lung tumours, this distinctive genetic feature, which is also immunohistochemically detectable as overexpression with a heterogeneous pattern, has diagnostic significance. The presence of this common genetic alteration found in both WDFA and BPB implies a histogenetic linkage between these tumours. Copyright © 2003 John Wiley & Sons, Ltd.
The attractive Achilles heel of germ cell tumours: an inherent sensitivity to apoptosis‐inducing stimuli
Authors: Spierings Diana CJ , de Vries Elisabeth GE , Vellenga Edo , de Jong Steven 
Published: May 2003

AbstractTesticular germ cell tumours (TGCTs) are extremely sensitive to cisplatin‐containing chemotherapy. The rapid time course of apoptosis induction after exposure to cisplatin suggests that TGCT cells are primed to undergo programmed cell death as an inherent property of the cell of origin. In fact, apoptosis induction of germ cells in the testis is an important physiological mechanism to control the quality and quantity of the gametes produced. Although p53 protein is highly expressed in the majority of TGCTs, almost no p53 mutations have been detected. Interestingly, p53 overexpression is associated with loss of p21 and gain of mdm2 expression, which might indicate a partial loss in functionality of the p53 regulatory pathway in TGCTs. Besides p21, TGCTs often show low expression of other proteins involved in the regulation of cell cycle progression, such as the retinoblastoma protein and members of the INK4 family. It can be postulated that the deregulated G1–S phase checkpoint results in premature entry into the S phase upon DNA damage. In addition to Bcl‐2 family members that are involved in the regulation of germ cell apoptosis in the normal testis via the mitochondrial death pathway, the Fas death pathway is also known to regulate apoptosis of germ cells in the testis. Since chemotherapy has been shown to activate the Fas death pathway and TGCTs co‐express both Fas and its ligand FasL, TGCT cells might undergo apoptosis upon cisplatin treatment via autocrine or paracrine activation of the Fas system by FasL. The hypothesis suggested here is that the lack of cell cycle arrest following a cisplatin‐containing treatment, together with the activation of the Fas death pathway and the mitochondrial death pathway, explains the rapid and efficient apoptosis of TGCT cells. Defining the mechanisms involved in the cisplatin sensitivity of TGCTs will provide tools to increase cisplatin sensitivity in other human tumours with acquired or intrinsic resistance. Copyright © 2003 John Wiley & Sons, Ltd.
Effects of ionic dissociation of membrane polymer on pervaporation performance
Authors: Iwatsubo Takashi , Masuoka Toshio , Mizoguchi Kensaku 
Published: April 2003

AbstractPervaporation of a water/alcohol mixture through a membrane which has ion‐exchange capacity has been investigated. Theoretical equations are introduced which relate the degree of ionic dissociation of the polymer to quantities of water and alcohol dissolved in the polymer. From these equations, an equation for selective dissolution R is derived which does not contain an explicit term for ionic dissociation. Dissociation affects selective dissolution only by changing the degree of swelling of the polymer. Reformulating R asymptotically obtains a reciprocal relationship between permselectivity and permeability for a water‐selective membrane. Experiments to check the validity of the relationship have been carried out using chitosan membranes neutralized by several acids. The effect of degree of neutralization also has been investigated. Results can be well understood on the supposition that ionic dissociation depends upon the water/alcohol composition, the kind of acid, and the degree of neutralization. Experimental results indicate that the reciprocal relationship is maintained over an appropriate range of feed compositions which confirm the validity of the theoretical equations for the swelling equilibrium of an ionic membrane. © 1994 John Wiley & Sons, Inc.
Negative excess volume of mixing in polybutadiene/polyisoprene blends
Authors: Kawahara Seiichi , Sato Kazuo , Akiyama Saburo 
Published: April 2003

AbstractThe temperature dependence of specific volume was measured for miscible polybutadiene/polyisoprene blends by dilatometry. The negative excess volume of mixing below the lower critical solution temperature was studied in terms of the Flory equation‐of‐state. In order to achieve a best‐fit of the calculated excess volume to the experimental excess volume, Flory's interaction parameter X12 was estimated to be negative for the blend. Thus, a stereo structural effect for mixing would be predicted, since only van der Waals dispersion forces are expected between blend components. Considering that one way to observe the stereo‐structural effect is to study conformational changes during mixing, solid‐state proton NMR measurements were conducted. Evidence of a conformational change was obtained for the blend. The occurrence of a structural effect was also suggested. © 1994 John Wiley & Sons, Inc.
Rheology of a mixture of liquid‐crystal polymers in solution
Authors: Ambrosino S. , Sixou P. 
Published: April 2003

AbstractThe rheological behavior of a mixture of two liquid‐crystal polymers, hydroxypropyl cellulose and ethyl cellulose, in acetone solution is studied. The total polymer concentration in the solvent is held constant (40%) as the ratio of the two polymers is varied. The mixtures are anisotropic, isotropic, or biphasic (isotropic/anisotropic), depending on the concentration. Curves of viscosity vs shear rate for all the mixtures studied show three regions of viscosity, as described by Onogi and Asada for liquid‐crystal polymers. The viscosity as a function of the weight ratio of the two polymers at constant shear rate exhibits deviations from additivity of viscosities of the two components at all concentrations. In mixtures of two polymers in the melt, deviations are also observed; the negative ones are attributed to phase separation and the positive ones to homogenous mixing (comparison with the phase diagram). All the mixtures studied (anisotropic, isotropic, or biphasic), show ranges of shear rates where the first normal‐stress difference is negative, as is generally observed for anisotropic liquid‐crystal polymers. It is concluded that the isotropic solutions become anisotropic under shear, as they are not far from the critical concentration. © 1994 John Wiley & Sons, Inc.
A broad‐band dielectric study of poly(vinyl chloride): Effect of molar mass and processing conditions on space‐charge mechanisms
Authors: Steeman P. A. M. , Gondard C. , Scherrenberg R. L. 
Published: April 2003

AbstractThe dielectric properties of poly(vinyl‐chloride) (PVC) were investigated as a function of frequency and temperature. Attention was focused on the low frequency dielectric properties. Samples with different molar masses were studied. Two dipolar retardation processes were observed, one due to a local motion in the polymeric chain and the other at the glass transition. In compression‐molded samples of high molar mass an additional low‐frequency space‐charge polarization mechanism was found at high temperatures. The effect was most pronounced at the highest molar masses. The space‐charge mechanism was absent in samples of well‐kneaded material. This macroscopic polarization process in compression molded samples is probably due to discontinuities in the poorly gelified material because of a residual grain particle structure. The detected effects of air inclusions in a PVC matrix can be described by the Maxwell‐Wagner theory. The magnitude of the space‐charge mechanism is an indication of the effectiveness of the processing method used in destroying the grain structure. © 1994 John Wiley & Sons, Inc.
Gas sorption and diffusion in hydrogen‐bonded polymers. II. Polyethersulfone/polyhydroxyether blends
Authors: Reimers M. J. , Barbari T. A. 
Published: April 2003

AbstractThe gas sorption behavior of CO2, C2H6, and CH4, and the gas transport behavior of CO2 and CH4, were examined for polyethersulfone (PES), polyhydroxyether, and four miscible blends containing 20, 40, 60, and 80 wt % PES. The 40 wt % PES blend exhibited the lowest sorption levels and the lowest permeabilities for all of the gases. Application of the dual‐mode sorption model revealed negative deviations for the Henry's law parameter kD that were larger than those observed for blends relying on van der Waals or simple polar interactions. Also, the magnitude of the blend interaction parameter obtained from the gas sorption data and the volume of mixing were both more negative in the hydrogen‐bonded blend. Diffusion coefficients at infinite dilution and from the dual mode/partial immobilization model exhibited minima at 40 wt % PES, as did the fractional free volume, a measure of chain packing ability. © 1994 John Wiley & Sons, Inc.
Quantitative confirmation of the crystal‐amorphous interphase in semicrystalline poly(vinylidene fluoride) and poly (vinylidene fluoride)/poly (ethyl methacrylate) blends
Authors: Ando Yutaka , Hanada Tomomi , Saitoh Kumiko 
Published: April 2003

AbstractDielectric and thermal characterizations were performed for poly (vinylidene fluoride) (PVDF)/poly (ethyl methacrylate) (PEMA) blends of different composition. The characteristics of PVDF β relaxation were shown to be little affected in the semicrystalline blends with PEMA. The relaxation strength, however, depends strongly on the PEMA content and a linear relation was found between the intensity of the β relaxation and the weight fraction of the PVDF crystal‐amorphous interphase. Phase structures of the PVDF/PEMA blends are also proposed. © 1994 John Wiley & Sons, Inc.
Drying of solvent‐coated polymer films
Authors: Vrentas J. S. , Vrentas C. M. 
Published: April 2003

AbstractA set of equations is developed for the description of heat and mass transfer and film shrinkage in the drying of polymer films. The utilization of jump balances in the formulation of boundary conditions at phase interfaces is illustrated, and a solution scheme is developed for solving the coupled, nonlinear equations. The proposed model will produce the size of drying over needed to reduce the solvent concentration to the desired level. © 1994 John Wiley & Sons, Inc.
Is Colonoscopy Alone Sufficient to Screen for Ulcerative Colitis‐associated Colorectal Carcinoma?
Authors: Bruewer Matthias , Krieglstein Christian F. , Utech Markus , Bode Marc , Rijcken Emile , Anthoni Christoph , Laukoetter Mike G. , Schuermann Guido , Senninger Norbert 
Published: May 2003

AbstractPatients with ulcerative colitis (UC) are at increased risk for colorectal carcinoma (CAC). Despite the fact that patients at risk are followed closely by colonoscopy to screen for dysplasia, the prevalence of CAC is still unacceptably high. The aim of this study was to evaluate the prevalence of risk factors for CAC, such as dysplasia, and to determine the relevance of colonoscopic surveillance in the group who went on to develop cancer. A series of 24 patients with UC were diagnosed with CAC. The patients’ records were analyzed retrospectively for duration of UC, prevalence of preoperative dysplasia, and other cancer risk factors (CRFs) (e.g., pancolitis, primary sclerosing cholangitis, early onset of UC, and backwash ileitis). The mean age of the patients at the time of cancer diagnosis was 43 years with an average UC duration of 15 years (6 patients had had UC less than 8 years). CAC was identified preoperatively by colonoscopy in 15 of 24 patients, with an additional 7 of 15 showing flat dysplasia. Five of nine patients without preoperatively diagnosed CAC had flat dysplasia. Overall, 19 patients had additional CRFs, most of them with at least two more CRFs. Despite a regular colonoscopic follow‐up for most patients with UC, flat dysplasia was missed in 12 patients preoperatively. Therefore we suggest that patient information should also always include surgical options in each case where significant cancer risk factors are found.
Long‐term Outcome after Inflammatory Abdominal Aortic Aneurysm Repair: Case‐matched Study
Authors: Bonati Luigi , Rubini Patrizia , Japichino Gioacchino G. , Parolari Alessandro , Contini Sandro , Zinicola Roberto , Fusari Melissa , Biglioli Paolo 
Published: May 2003

AbstractThe purpose of this study was to compare early and late outcomes after inflammatory and noninflammatory abdominal aortic aneurysm (AAA) repair with emphasis on graft‐related complications. Of 625 consecutive patients submitted to AAA repair, 18 were classified as having inflammatory AAAs (group 1). The results of this group were compared with those of 54 patients (group 2) retrospectively drawn from patients who underwent aortic replacement for noninflammatory AAAs. A computer‐assisted matching system was used to match patients according to date of birth, gender, and surgical priority. All patients of both groups were followed by periodic clinical and instrumental examinations. Patients in group 1 complained more frequently of aneurysm‐related symptoms (72% vs. 20%; p = 0.0001), and their erythrocyte sedimentation rate was elevated more often (78% vs. 19%; p < 0.0001). Surgical morbidity and mortality rates were not different. The mean lengths of follow‐up were 61 ± 47 months (group 1) and 71 ± 38 months (group 2). The 10‐year overall survival rates did not differ significantly between the two groups (49.1% ± 16.9% for group 1 vs. 61.6% ± 13.8% for group 2; p = 0.26, log‐rank test). In contrast, the free from paraanastomotic aneurysm survival rates were significantly lower in group 1 (57.3% ± 20.2% vs. 97.8% ± 2.5% at 10 years; p = 0.025, log‐rank test). Long‐term outcomes showed a higher incidence of graft‐related complications in group 1. As inflammatory aneurysms might represent a risk factor for the development of paraanastomotic aneurysms, routine imaging surveillance of graft aortic healing after inflammatory AAA repair is warranted.
Optimal Lymphadenectomy for Squamous Cell Carcinoma in the Thoracic Esophagus: Comparing the Short‐ and Long‐term Outcome among the Four Types of Lymphadenectomy
Authors: Fujita Hiromasa , Sueyoshi Susumu , Tanaka Toshiaki , Fujii Teruhiko , Toh Uhi , Mine Takashi , Sasahara Hiroko , Sudo Tomoya , Matono Satoru , Yamana Hideaki , Shirouzu Kazuo 
Published: May 2003

AbstractControversy continues over the optimal extent of lymphadenectomy (regional versus three‐field) for a potentially resectable squamous cell carcinoma in the thoracic esophagus. In the Consensus Conference of the International Society for Diseases of the Esophagus (ISDE), held in Munich in 1994, the types of lymphadenectomy were classified as standard, extended, total, or three‐field lymphadenectomy. The objective of the present study was to determine the optimal procedure among these four types of lymphadenectomy. The mortality and morbidity rates, postoperative course, and survival rates were compared among 302 patients who underwent curative (R0) transthoracic esophagectomy with one of these four types of lymphadenectomy at Kurume University Hospital, Fukuoka, Japan, from 1986 to 1998. Three‐field lymphadenectomy resulted in better survival than any other type of lymphadenectomy for patients with positive lymph node metastasis from a cancer in the upper or middle thoracic esophagus. A postoperative complication, such as recurrent laryngeal nerve paralysis, anastomotic leakage, and tracheal ischemic lesion, was significantly more common after three‐field lymphadenectomy. However, the mortality rate was the same among the four procedures. Three‐field lymphadenectomy was optimal for an upper or middle thoracic esophageal cancer with metastasis in the lymph node(s) based on improved long‐term survival, whereas there was not a large difference in short‐term and long‐term outcomes after the four types of lymphadenectomy for a lower thoracic esophageal cancer.
Service markets and competition
Authors: Karmarkar Uday S. , Pitbladdo Richard 
Published: May 2003

AbstractThe production and delivery of services differ from manufacturing in ways which have a significant impact on the nature of market competition. Contracts for manufactured goods are centered around a clearly defined junction between production and use, made possible by the properties of tangibility and portability of tangible goods, at which point responsibility for use, operation and consumption of the product is transferred from producer to customer, along with ownership. Service operations, by contrast, involve a lack of inventories and portability, customer contact, joint production, customer‐specific inputs, and intangibility in varying degrees. Moreover, service operations are either entirely post contractual or interlinked with the contracting process. As a result, the very nature of service markets and contracting depends on the characteristics of the service operation. While the operational consequences of service characteristics have been explored quite widely, there is less understanding of the special features of service competition and its implications for service strategy. We provide a framework for describing, analyzing and explaining service competition and review some old and new models which address the special features of service markets.
Economics of total quality management
Authors: Lederer Phillip J. , Rhee Seung‐Kyu 
Published: May 2003

AbstractThis paper presents two models of the economics of total quality management. In the first, the concept of quality management is viewed as a technological innovation that requires investment. To reduce cost and improve quality, firms must make investments that are largely sunk. The effect of market competition on quality related technology investments is studied. Several results follow. With new quality technologies, price falls, quality rises and average cost declines. Firms must anticipate rivals' technology choices and the market prices when justifying quality technology investments. When all firms quickly adopt quality technology, returns of such investments are normal, that is, have a zero net present value. However, firms that do not invest in quality related technology are forced from the market. A firm that is faced by competitors that are slow to adopt quality related technology, can earn positive returns by early adoption. The firm invests more in quality related technology, and produces higher quality products, charges a higher price and earns higher profits than competitors. The firm's quality, price and profit advantages persist over time. In the second model, we show that firm value increases when customer satisfaction is used as an objective by aligning incentives. This explains the common use of customer satisfaction measures in TQM programs.
Hierarchical capacity expansion and production planning decisions in stochastic manufacturing systems
Authors: Sethi S.P. , Taksar M. , Zhang Q. 
Published: May 2003

AbstractWe present an approach of hierarchical decision making in production planning and capacity expansion problems under uncertainty. We show that under reasonable assumptions, the strategic level management can base the capacity decision on aggregated information from the shopfloor, and the operational level management, given this decision, can derive a production plan for the system, without too large a loss in optimality when compared to simultaneous determination of optimal capacity and production decisions.The results are obtained via an asymptotic analysis of hierarchical investment and production decisions in a manufacturing system with machines subject to breakdown and repair. The demand facing the system is assumed to be a deterministic monotone increasing function. The production capacity can be increased by purchasing a finite number of new machines over time. The control variables are a sequence of purchasing times and a production plan. The rate of change in machine states is assumed to be much larger than the rate of discounting of costs. This gives rise to a limiting problem in which the stochastic machine availability is replaced by the equilibrium mean availability. The value function for the original problem converges to the value function of the limiting problem. Three different methods are developed for constructing decisions for the original problem from the optimal solution of the limiting problem in a way which guarantees the asymptotic optimality of constructed decisions. Finally, it is shown that as the number of machine that could be purchased tends to infinity, the problem approximates the corresponding problem with no limit on number of machine purchases.