bluuebunny/crossref_metadata_2025_split huggingface dataset:
Clinical impact and functional aspects of tenascin‐C expression during glioma progression
Authors: Herold‐Mende Christel , Mueller Margareta M. , Bonsanto Mario M. , Schmitt Horst Peter , Kunze Stefan , Steiner Hans‐Herbert 
Published: August 2002

AbstractThe extracellular matrix protein tenascin‐C is expressed in processes like embryogenesis and wound healing and in neoplasia. Tenascin‐C expression in gliomas has been described previously; however, the relation to clinical data remains inconsistent. Generally, analysis of tenascin‐C function is difficult due to different alternatively spliced isoforms. Our studies focus on changes in tenascin‐C expression in human gliomas, correlating these changes with tumor progression and elucidating the functional role of the glioma cell‐specific tenascin‐C isoform pool. Eighty‐six glioma tissues of different World Health Organization (WHO) grades were analyzed immunohistochemically for tenascin‐C expression. The influence of the specific tenascin‐C isoforms produced by glioblastoma cells on proliferation and migration was examined in vitro using blocking antibodies recognizing all isoforms. In general, tenascin‐C expression increased with tumor malignancy. Perivascular staining of tenascin‐C around tumor‐supplying blood vessels was observed in all glioblastoma tissues, whereas in WHO II and III gliomas, perivascular tenascin‐C staining appeared less frequently. The appearance of perivascular tenascin‐C correlated significantly with a shorter disease‐free time. Analysis of proliferation and migration in the presence of blocking antibodies revealed an inhibition of proliferation by around 30% in all 3 glioblastoma cell cultures, as well as a decrease in migration of 30.6–46.7%. Thus we conclude that the endogenous pool of tenascin‐C isoforms in gliomas supports both tumor cell proliferation and tumor cell migration. In addition, our data on the perivascular staining of tenascin‐C in WHO II and III gliomas and its correlation with a shorter disease‐free time suggest that tenascin‐C may be a new and potent prognostic marker for an earlier tumor recurrence. © 2002 Wiley‐Liss, Inc.
Cytotoxic T lymphocyte mediated recognition of human pancreatic cancer cells
Authors: Peiper Matthias , Sato Takeo , Streichert Thomas , Eisenberger Claus Ferdinand , Knoefel Wolfram Trudo , Izbicki Jakob Robert 
Published: August 2002

AbstractT lymphocytes play an important role in tumor rejection and their response to human malignant melanoma has been well documented. In contrast, the existence of cytotoxic T lymphocytes (CTL) to pancreatic cancer remains unclear. Tumor‐associated lymphocytes (TAL) and peripheral blood monocytes (PBMC) were isolated from pancreatic cancer patients. Tumor‐specific CTL were generated from TAL and PBMC using solid‐phase anti‐CD3, low‐dose IL‐2 (50 IU/ml) and repetitive autologous tumor stimulation. The specificity of CTL was tested in standard cytotoxicity assays using autologous tumor cells, autologous fibroblasts when available, several allogeneic pancreatic tumor cells and the NK‐sensitive cell line K562. Anti‐HLA‐Class I MAb, W6/32, was used to demonstrate that tumor‐specific CTL were HLA‐Class I restricted. HLA‐molecules of human pancreatic cancer cells were washed out using acid elution. Eight consecutive, histologically confirmed pancreatic cancer specimen as well as peripheral blood mononuclear cells were analyzed. CTL were capable of lysing autologous tumor cells significantly after 3 stimulations with autologous tumor cells. T cell mediated recognition was HLA‐Class I restricted as shown by incubation with MAb anti‐HLA‐Class I. In case of HLA‐A2 positivity, incubation of tumor cells in cytotoxicity assays resulted in significant inhibition. Autologous fibroblasts or K562 cells were lysed significantly less. HLA‐Class I molecule elution resulted in significantly lower recognition of these cells by CTL. These results show for the first time in a larger series the possibility of generating CTL in human pancreatic cancer. The identification of new tumor associated antigens or tumor antigens will be crucial for establishing new treatment strategies. © 2002 Wiley‐Liss, Inc.
Inhibition of experimental pulmonary metastasis by controlling biodistribution of catalase in mice
Authors: Nishikawa Makiya , Tamada Ayumi , Kumai Hitomi , Yamashita Fumiyoshi , Hashida Mitsuru 
Published: August 2002

AbstractIn a previous study, we showed that targeted delivery of bovine liver catalase to hepatocytes by direct galactosylation augmented the inhibitory effect of the enzyme on experimental hepatic metastasis of colon carcinoma cells (unpublished data). Here, we examined the ability of catalase to inhibit tumor metastasis to the lung by controlling its biodistribution. Four types of catalase derivative, Gal‐CAT, Man‐CAT, Suc‐CAT and PEG‐CAT, were synthesized. Experimental pulmonary metastasis was induced in mice by i.v. injection of 1 × 105 colon 26 tumor cells. An i.v. injection of catalase (35,000 units/kg) partially, but significantly, decreased the number of colonies in the lung 2 weeks after tumor injection, from 93 ± 29 (saline injection) to 63 ± 23 (p < 0.01). Suc‐CAT, Man‐CAT and Gal‐CAT showed effects similar to those of catalase on the number of colonies. However, PEG‐CAT greatly inhibited pulmonary metastasis to 22 ± 11 (p < 0.001). Furthermore, s.c. injection of catalase also greatly inhibited metastasis (11 ± 6, p < 0.001). Neither inactivated catalase nor BSA showed any effects on the number of metastatic colonies, indicating that the enzymatic activity of catalase to detoxify H2O2 is the critical factor inhibiting metastasis. 111In‐PEG‐CAT showed a sustained concentration in plasma, whereas s.c.‐injected 111In‐catalase was slowly absorbed from the injection site. These results suggest that retention of catalase activity in the circulation is a promising approach to inhibit pulmonary metastasis. © 2002 Wiley‐Liss, Inc.
Expression of heavy subunit of γ‐glutamylcysteine synthetase (γ‐GCSh) in human colorectal carcinoma
Authors: Tatebe Shigeru , Unate Hitoshi , Sinicrope Frank A. , Sakatani Takashi , Sugamura Kenji , Makino Masato , Ito Hisao , Savaraj Niramol , Kaibara Nobuaki , Kuo M. Tien 
Published: August 2002

AbstractGamma‐glutamylcysteine synthetase (γ‐GCS) is a heterodimer consisting of heavy (γ‐GCSh) and light (γ‐GCSl) subunits. γ‐GCS catalyzes the rate‐limiting de novo biosynthesis of glutathione (GSH), an abundant physiological antioxidant that plays important roles for regulating oxidative stress. Expression of γ‐GCSh and γ‐GCSl are sensitive to oxidative stress. To investigate whether expression of γ‐GCS is correlated with tumor progression, we used immunohistochemical approaches to examine 16 human colorectal adenomas and resected 57 carcinomas from untreated patients. In adjacent normal colorectal epithelium, levels of γ‐GCSh expression were low. Strong cytoplasmic staining for γ‐GCSh was detected in 3 (18.8%) adenoma and 48 (84.2%) carcinomas. The frequency of γ‐GCSh expression in carcinoma was significantly higher than in adenoma (p<0.0001). We used RNase protation assay and Western blot to determine levels of γ‐GCSh mRNA and protein from 10 pairs of matched carcinomas with adjacent normal controls. Elevated expression of both γ‐GCSh mRNA and protein were found in 6 cases, suggesting that transcriptional and/or posttranscriptional regulation play an important role in the upregulation of γ‐GCS during colorectal carcinogenesis. We also examined the expression of another redox‐regulated gene, multidrug resistance protein 1 (MRP1). Strong staining for MRP1 was detected in 1 (6.3%) adenoma and 40 (70.2%) carcinomas. The frequency of MRP1 expression in carcinoma was significantly higher than in adenoma ( p<0.0001). Nuclear p53 expression was detected in 30 (52.6%) of carcinomas. There is a significant correlation between γ‐GCSh and MRP1 expression (p=0.013) but not between γ‐GCSh and p53. Since γ‐GCS is a sensor of oxidative stress, these results are consistent with the notion that oxidative stress is associated with colorectal tumor progression. © 2002 Wiley‐Liss, Inc.
A comparative study of normal inspection, autofluorescence and 5‐ALA‐induced PPIX fluorescence for oral cancer diagnosis
Authors: Betz Christian S. , Stepp Herbert , Janda Philip , Arbogast Susanne , Grevers Gerhard , Baumgartner Reinhold , Leunig Andreas 
Published: August 2002

AbstractFluorescence diagnosis aims to improve the management of oral cancer via early detection of the malignant lesions and better delimitation of the tumor margins. This paper presents a comparative study of normal inspection, combined fluorescence diagnosis (CFD) and its 2 main components, autofluorescence and 5‐aminolevulinic acid (5‐ALA)‐induced protoporphyrin IX (PPIX) fluorescence. Biopsy‐controlled fluorescence imaging and spectral analysis were performed on a total of 85 patients with suspected or histologically proven oral carcinoma both before and after topical administration of 5‐ALA (200 mg 5‐ALA dissolved in 50 ml of H20). Fluorescence excitation was accomplished using filtered light of a xenon short arc lamp (λ = 375–440 nm). As for CFD, a “streetlight” contrast (red to green) was readily found between malignant and healthy tissue on the acquired images. In terms of tumor localization and delimitation properties, CFD was clearly favorable over either normal inspection or its 2 components in fluorescence imaging. The performance of CFD was found to be impeded by tumor keratinization but to be independent of either tumor staging, grading or localization. In spectral analysis, cancerous tissue showed significantly higher PPIX fluorescence intensities and lower autofluorescence intensities than normal mucosa. There is a great potential for CFD in early detection of oral neoplasms and exact delimitation of the tumors' superficial margins and an advantage over white light inspection and each of its 2 main components. The method is noninvasive, safe and easily reproducible. © 2002 Wiley‐Liss, Inc.
Long‐term memory in stock market returns: international evidence
Authors: Sadique Shibley , Silvapulle Param 
Published: August 2002

AbstractA lot of recent work has addressed the issue of the presence of long memory components in stock prices because of the controversial implications of such a finding for market efficiency and for martingale models of asset prices used in financial economics and technical trading rules used for forecasting. This paper examines the presence of long memory in the stock returns of seven countries, namely Japan, Korea, New Zealand, Malaysia, Singapore, the USA and Australia. The classical and modified rescaled range tests, the semiparametric test proposed by Geweke and Porter‐Hudak, the frequency domain score test proposed by Robinson and its time‐domain counterpart derived by Silvapulle, are applied to these returns in order to detect the long memory property. Evidence suggests that the Korean, Malaysian, Singapore and New Zealand stock returns are long‐term dependent, indicating that these two markets are not efficient. The results of this study should be useful to regulators, practitioners and derivative market participants, whose success precariously depends on the ability to forecast stock price movements. Copyright © 2001 John Wiley & Sons, Ltd.
Irreducibility and structural cointegrating relations: an application to the G‐7 long‐term interest rates
Authors: Barassi Marco R. , Caporale Guglielmo Maria , Hall Stephen G. 
Published: August 2002

AbstractIn this paper we examine the causal linkages between the G‐7 long‐term interest rates by using a new technique, which enables the researcher to analyse relations between a set of I(1) series without imposing any identification conditions based on economic theory. Specifically, we apply the so‐called Extended Davidson's Methodology (EDM), which is based on the innovative concept of an irreducible cointegrating (IC) vector, defined as a subset of a cointegrating relation that does not have any cointegrated subsets. Ranking the irreducible vectors according to the criterion of minimum variance allows us to distinguish between structural and solved relations. The empirical results provide support for the hypothesis that larger, more stable economies can achieve policy objectives more successfully by accommodating rather than driving other countries' policies. It appears that the driving force is Canada, which is linked to the USA, UK and France in three out of the four fundamental relations, and which is a reference point for the US, Italian and German rates, which are not cointegrated, seem to be determined by country‐specific factors. Copyright © 2001 John Wiley & Sons, Ltd.
Retire to where? A discrete choice model of residential location
Authors: Duncombe William , Robbins Mark , Wolf Douglas A. 
Published: August 2002

AbstractMany studies of migration attempt to identify attributes of places that influence residential location decisions. Most such studies relate an area's migration rates to its own attributes, or the flow of migrants between two areas to the attributes of both places. We focus on retirement migration within the US, and extend the literature by using a discrete choice framework in which a person's location decision depends on the attributes of all potential locations. Using a multinomial logit specification and 1990 Census county‐to‐county migration data, we model the location choice of individuals aged 65 to 74 years from among more than 3000 counties. In order to make the estimation problem manageable, we employ the sampling‐of‐alternatives approach of McFadden, and use aggregated migratory‐flow data for which existing estimation software is applicable. Our results indicate that, in general, persons around retirement age avoid high taxes and housing costs, while they are drawn to areas with relatively high spending on such services as fire, police and recreation. Amenities such as coastline and warm weather are also valued. Copyright © 2001 John Wiley & Sons, Ltd.
Alterations in hepatic detoxifying enzymes induced by new organophosphorus insecticides following subchronic exposure in rats
Authors: Mahboob M. , Siddiqui M. K. J. 
Published: August 2002

AbstractThe present study examined the structure–toxicity relationship of two novel phosphorothionates, a methyl ester (RPR‐II) and an ethyl ester (RPR‐V), with regard to their interaction with certain biochemical indices in rat. Male rats were treated orally with 10% (low), 20% (medium) and 30% (high) doses of the two compounds (14, 28 and 42 µg kg−1 day −1 of RPR‐II and 33, 66 and 99 µg kg−1 day−1 of RPR‐V) daily for 90 days. The activity of hepatic glutathione S‐transferase (GST) and UDP‐glucuronyl transferase (UDPGT) and the level of glutathione (GSH) were estimated at 0, 45 and 90 days of treatment as well as 28 days after cessation of treatment. RPR‐II caused statistically significant depletion of GSH after 45 and 90 days of treatment at the high dose, whereas RPR‐V depleted GSH only after 90 days at the high dose. RPR‐II inhibited GST after 45 and 90 days at medium and high doses, whereas RPR‐V caused inhibition of GST after 45 and 90 days only at the high dose. Significantly, UDPGT activity was increased only by the high dose of RPR‐II after 90 days. However, a dose and time‐dependent increase in UDPGT activity was observed at all three doses of RPR‐V after 45 and 90 days. There was no modulation in any of the three indices at low doses of the two organophosphorus insecticides. The withdrawal study revealed that induced changes in hepatic parameters were reversible 28 days after cessation of treatment. The results indicated that the two insecticides had different potential to modulate hepatic GST, UDPGT and GSH due to subchronic exposure and that these metabolic alterations are quite reversible after withdrawal of treatment. Copyright © 2001 John Wiley & Sons, Ltd.
Micro‐wear patterns on UHMWPE tibial inserts in total knee joint simulation
Authors: Tamura Jiro , Clarke Ian C. , Kawanabe Keiichi , Akagi Masao , Good Victoria D. , Williams Paul A. , Masaoka Toshinori , Schroeder Dave , Oonishi Hironobu 
Published: August 2002

AbstractThe objective of this study was to examine both simulator and retrieved total knee replacement polyethylene inserts to confirm, using scanning electron microscopy, whether similar micro‐wear patterns to those seen on retrieved inserts were reproduced on simulator specimens. The simulator specimens consisted of samples subjected to sliding and rolling movement (Experiment 1) and to sliding movement only (Experiment 2). Samples from Experiment 1 demonstrated longitudinal patterns in the middle of the wear track and transverse patterns in the anterior and posterior ends, whereas in Experiment 2, only transverse patterns were observed. In the retrieved specimens, both longitudinal and transverse patterns were observed. The results showed that the simulator study reproduced similar patterns of micro‐damage on polyethylene, and that the longitudinal micro‐wear pattern was related to the rolling movement that is distinctive in knee kinematics. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res 61: 218–225, 2002
The effect of structural characteristics on the in vitro bioactivity of hydroxyapatite
Authors: Shi Donglu , Jiang Gengwei , Bauer Jennifer 
Published: August 2002

AbstractIn previous studies a film of hydroxylapatite (HA) was coated onto the inner pore surfaces of reticulated alumina for bone substitutes with the use of a so‐called thermal deposition method. In this process, the HA films must be sintered at high temperatures for a strong adhesion to the alumina substrate. It has been found that high‐temperature sintering inevitably changes the crystallinity of the coated HA, and in turn affects its bioactivity. Therefore, in this study, in vitro experiments were carried out to investigate the effects of structural changes on the in vitro bioactivity. The factors dominating in vitro bioactivity of HA, including surface area, degree of crystallinity, and temperature, were identified. The activation energy for volume diffusion was calculated for different in vitro solution temperatures. Also discussed is the underlying mechanism of growth and dissolution processes during the in vitro test. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res (Appl Biomater) 63: 71–78, 2002
The sintered microsphere matrix for bone tissue engineering: In vitro osteoconductivity studies
Authors: Borden Mark , Attawia Mohamed , Laurencin Cato T. 
Published: August 2002

AbstractA tissue engineering approach has been used to design three‐dimensional synthetic matrices for bone repair. The osteoconductivity and degradation profile of a novel polymeric bone‐graft substitute was evaluated in an in vitro setting. Using the copolymer poly(lactide‐co‐glycolide) [PLAGA], a sintering technique based on microsphere technology was used to fabricate three‐dimensional porous scaffolds for bone regeneration. Osteoblasts and fibroblasts were seeded onto a 50:50 PLAGA scaffold. Morphologic evaluation through scanning electron microscopy demonstrated that both cell types attached and spread over the scaffold. Cells migrated through the matrix using cytoplasmic extensions to bridge the structure. Cross‐sectional images indicated that cellular proliferation had penetrated into the matrix approximately 700 μm from the surface. Examination of the surfaces of cell/matrix constructs demonstrated that cellular proliferation had encompassed the pores of the matrix by 14 days of cell culture. With the aim of optimizing polymer composition and polymer molecular weight, a degradation study was conducted utilizing the matrix. The results demonstrate that degradation of the sintered matrix is dependent on molecular weight, copolymer ratio, and pore volume. From this data, it was determined that 75:25 PLAGA with an initial molecular weight of 100,000 has an optimal degradation profile. These studies show that the sintered microsphere matrix has an osteoconductive structure capable of functioning as a cellular scaffold with a degradation profile suitable for bone regeneration. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res 61: 421–429, 2002
Biological characterization of a novel biodegradable antimicrobial polymer synthesized with fluoroquinolones
Authors: Woo G. L. Y. , Yang M. L. , Yin H. Q. , Jaffer F. , Mittelman M. W. , Santerre J. P. 
Published: August 2002

AbstractBiomaterial‐related infections continue to represent a significant challenge to the medical community. Several approaches have been utilized to incorporate antimicrobial agents at the surface of implant devices in attempts to delay or eliminate the formation of biofilms. To date, most of these strategies have focused on drug conjugation or diffusion‐limited systems for the delivery of such pharmaceutical agents. More recently, work has been presented on the feasibility of incorporating drugs into the backbone of polymers as a main‐chain monomer. When sequenced into the backbone of the polymer with other monomers that are hydrolytically sensitive to enzyme‐catalyzed breakdown, it is thought that drugs may be able to be selectively released. Specifically, degradable polyurethanes have been synthesized with fluoroquinolone antibiotics and have shown an ability to kill bacteria when released following degradation of the polymer chains by the macrophage‐derived enzyme cholesterol esterase. However, specificity of the cleavage sites in the polymer was difficult to control. Since cholesterol esterase has specificity for hydrophobic moieties, it is desirable to alter the formulation of the polyurethanes to incorporate long hydrophobic monomers immediately adjacent to the ciprofloxacin molecule. Hence, the current study focuses on evaluating the enzyme‐catalyzed degradation of a degradable polyurethane synthesized with 1,12 diisocyanatododecane as a substitute for 1,6 diisocyanatohexane, which was used in previous work. Validation of specific ciprofloxacin release and the generation of antimicrobial are shown. A preliminary cell study to assess the cytotoxicity of this biodegradable antibiotic polymer shows that the material has no observable effects on cell proliferation or cell membrane structure. © 2001 Wiley Periodicals, Inc., J Biomed Mater Res 59: 35–45, 2002
Hypothermia‐induced platelet aggregation in human blood in an in vitro model: The dominant role of blood‐material interactions
Authors: Hall Matthew W. , Solen Kenneth A. 
Published: August 2002

AbstractHypothermia‐induced platelet aggregation (HIPA) with or without neutrophil involvement may cause neurologic dysfunction during hypothermic surgery. We report the use of a previously developed model to study the contributions of several surfaces, surface area, shear rate, and blood–material exposure time to HIPA. Heparinized (1.5 u/mL) human blood was quenched to 24°C and passed (0.5 mL/min) through a 75‐cm long 1/32” ID tubing of polyvinylchloride (PVC), polyethylene (PE), polyurethane (PU), Teflon‐FEP, or heparin (Duraflo)‐coated PVC. The number of aggregates was measured by a light‐scattering method, and the concentration of occlusive aggregates was assessed using constant‐pressure filtration (50 mmHg). No differences were seen among PVC, PE, PU, or Teflon‐FEP. The heparin‐coated PVC tubing produced fewer occlusive aggregates, and heparin leaching from the coating was not the cause of the decrease in occlusive aggregates. Increasing surface area increased the number of aggregates, and increasing shear rates decreased the occlusiveness of those aggregates. ©2001 Wiley Periodicals, Inc. J Biomed Mater Res 59: 528–534, 2002