bluuebunny/crossref_metadata_2025_split huggingface dataset:
Children prenatally exposed to substances: Gender‐related differences in outcome from infancy to 3 years of age
Authors: Moe Vibeke , Slinning Kari 
Published: August 2002

AbstractA group of 78 children with polysubstance exposure in utero and a comparison group of 58 children with no known risk status were followed from infancy to age 3 years. Sixty‐six children (84.6%) in the exposed group were taken into custody, and were either placed in foster homes or adopted. The foster parents were specially recruited to provide care to infants at risk. The substance‐exposed group exhibited significantly lower birthweight, gestational age, and head circumference than the comparison group. The perinatal data demonstrated no gender differences. The children were assessed on the Bayley‐II Scales of Infant Development at 1, 2, and 3 years of age. The results yielded a significant group by gender interaction on the Bayley‐II MDI. The boys, but not the girls who had been prenatally exposed to polydrugs, alcohol, and tobacco earned significantly lower MDI scores at 1, 2, and 3 years of age than the comparison group at the corresponding ages. The gender differences were still statistically significant when controlling for the effects of prematurity and the caregivers' socioeconomic status. This suggests a special vulnerability in prenatally substance‐exposed boys, perhaps because of cumulative risk. However, this group of exposed children did show a developmental catch‐up across the first 3 years of life. We suggest that the optimized caregiving environment had a buffering effect, and may have compensated for initial developmental lags in this group of children. ©2001 Michigan Association for Infant Mental Health.
Daily exchange rate behaviour and hedging of currency risk
Authors: Bos Charles S. , Mahieu Ronald J. , Van Dijk Herman K. 
Published: August 2002

AbstractWe construct models which enable a decision maker to analyse the implications of typical time series patterns of daily exchange rates for currency risk management. Our approach is Bayesian where extensive use is made of Markov chain Monte Carlo methods. The effects of several model characteristics (unit roots, GARCH, stochastic volatility, heavy‐tailed disturbance densities) are investigated in relation to the hedging strategies. Consequently, we can make a distinction between statistical relevance of model specifications and the economic consequences from a risk management point of view. We compute payoffs and utilities from several alternative hedge strategies. The results indicate that modelling time‐varying features of exchange rate returns may lead to improved hedge behaviour within currency overlay management. Copyright © 2000 John Wiley & Sons, Ltd.
Model uncertainty in cross‐country growth regressions
Authors: Fernández Carmen , Ley Eduardo , Steel Mark F. J. 
Published: August 2002

AbstractWe investigate the issue of model uncertainty in cross‐country growth regressions using Bayesian Model Averaging (BMA). We find that the posterior probability is spread widely among many models, suggesting the superiority of BMA over choosing any single model. Out‐of‐sample predictive results support this claim. In contrast to Levine and Renelt (1992), our results broadly support the more ‘optimistic’ conclusion of Sala‐i‐Martin (1997b), namely that some variables are important regressors for explaining cross‐country growth patterns. However, care should be taken in the methodology employed. The approach proposed here is firmly grounded in statistical theory and immediately leads to posterior and predictive inference. Copyright © 2001 John Wiley & Sons, Ltd.
Improved erythrocyte lysis assay in microtitre plates for sensitive detection and efficient measurement of haemolytic compounds from ichthyotoxic algae
Authors: Eschbach Erik , Scharsack Jörn P. , John Uwe , Medlin Linda K. 
Published: August 2002

AbstractHaemolytic substances produced by ichthyotoxic algae often are unknown in molecular structure or specific mechanism of toxicity. Detection and quantification of such substances are dependent on bioassays, using markers that are sensitive for haemolytic impairment and generation of a recordable response. The erythrocyte lysis assay (ELA) represents an advantageous bioassay in this respect, because the lytic response can be measured photometrically by the amount of released haemoglobin. The aim of the present study was to establish an improved assay based on the ELA principle, for sensitive determination of haemolytic substances of microalgae and for high sample throughput. For this purpose we adapted the ELA to a 96‐well microtitre plate format, which significantly reduced the sample volumes and allowed rapid processing of samples. Further improvement was achieved by measuring absorption of lysed erythrocytes at 414 nm, which significantly increased the sensitivity of the ELA compared to the measurements at 540 nm that are usually applied in this type of assay. Using carp (Cyprinus carpio) erythrocytes it was possible to detect haemolysis induced by 4 µg ml−1 of saponin and as little as two haemolytic Alexandrium tamarense cells. It is suggested that this improved ELA in microtitre plates be used as a low‐cost monitoring tool for detection and analysis of potential harmful algae. Furthermore, this ELA can be useful as a sensitive screening system for substances of pharmacological interest, e.g. selectively acting cytolytic antibiotics. Copyright © 2001 John Wiley & Sons, Ltd.
Lack of teratogenicity of microcystin‐LR in the mouse and toad
Authors: Chernoff N. , Hunter E. S. , Hall L. L. , Rosen M. B. , Brownie C. F. , Malarkey D. , Marr M. , Herkovits J. 
Published: August 2002

AbstractMicrocystin‐LR (MC‐LR) is a cyanobacterial toxin generated by the organism Microcystis aeruginosa. Although the hepatotoxicity of this chemical has been characterized, the potential developmental toxicity in vertebrates has not been well studied. The purpose of this study was to elucidate the effects of this toxin on the in vivo and in vitro development of mammals and the development of an Anuran (toad). Initial acute toxicity experiments with female CD‐1 mice were accomplished with MC‐LR administered i.p. in saline. Lethality occurred at 128 and 160 µg kg −1 and histopathology revealed massive hepatic necrosis with diffuse hemorrhage. Developmental toxicity studies were done with MC‐LR administered i.p. for 2‐day periods: gestation days 7–8, 9–10 or 11–12. Doses used ranged from 2 to 128 µg kg−1. On gestation day 17, fetuses were weighed and analyzed for gross morphological and skeletal defects. No treatment‐related differences were seen in litter size, viability, weight or the incidence of anomalies. Groups of dams dosed with 32–128 µg kg−1 on gestation days 7–8, 9–10 or 11–12 were allowed to give birth and the growth and development of their pups were followed postnatally. There were no significant effects noted in the offspring of the treated dams. Neurulation‐staged CD‐1 mouse conceptuses were exposed to 50–1000 nM MC‐LR in whole embryo culture for 24 h. No significant increase in abnormalities or developmental delays was observed. Finally, exposure of the developing toad. Bufo arenarum was done from stage 17 (tail bud) for 10 days at concentrations of 1–20 mg l−1. No effect on morphological development or survival was noted in any exposed groups. These data indicate that microcystin does not appear to affect development adversely in the mouse (in vivo or in vitro) or the toad at the doses and exposure parameters used. Copyright © 2002 John Wiley & Sons, Ltd.
Prosthetic metals have a variable necrotic threshold in human fibroblasts: An in vitro study
Authors: Mostardi Richard A. , Pentello Amie , Kovacik Mark W. , Askew Michael J. 
Published: August 2002

AbstractThe generation of metal particles from prosthetic joints has been an evolving problem in orthopedics. Numerous factors have been involved including cells, metals, and responding cytokines, but determining roles of these factors or cascades of factors has been elusive. This laboratory has published threshold levels for commercially pure titanium (CpTi), which led to cell necrosis, but noted that cell viability differed among donor patients. To compliment the previous work we examined two other metals, Tantalum (Ta) and cobalt‐chrome (CoCr), while making comparative measurements in these different donor patients. Retrieved human fibroblasts (superior medial plica) were cultured in a standard manner and exposed to various dosages of the three metals. Cell counts and interleukin (IL) 6 were used as dependent variables within a three‐way analysis of variance. The data show that fibroblast necrosis was significantly affected by both type and mass of metal, with each metal having a distinct threshold (CpTi most necrotic, followed by Ta and CoCr). The cell counts and IL‐6 at control levels varied significantly among all three donors. However, the response to the metals and dosages did not differ among tissue donors. Thus, although each patient had a different starting value for cell counts and IL‐6, they responded to the metal particles in the same proportionate manner. © 2001 Wiley Periodicals, Inc. J Biomed Mater Res 59: 605–610, 2002
Trabecular bone response to injectable calcium phosphate (Ca‐P) cement
Authors: Ooms E. M. , Wolke J. G. C. , van der Waerden J. P. C. M. , Jansen J. A. 
Published: August 2002

AbstractThe aim of this study was to investigate the physicochemical, biological, and handling properties of a new developed calcium phosphate (Ca‐P) cement when implanted in trabecular bone. Ca‐P cement consisting of a powder and a liquid phase was implanted as a paste into femoral trabecular bone of goats for 3 days and 2, 8, 16, and 24 weeks. The cement was tested using three clinically relevant liquid‐to‐powder ratios. Polymethylmethacrylate bone cement, routinely used in orthopedics, was used as a control. The Ca‐P cement was easy to handle and was fast setting with good cohesion when in contact with body fluids. X‐ray diffraction at the different implantation periods showed that the cement had set as an apatite and remained stable over time. Histological evaluation after 2 weeks, performed on 10 μm un‐decalcified sections, showed abundant bone apposition on the cement surface without any inflammatory reaction or fibrous encapsulation. At later time points, the Ca‐P cement implants were totally covered by a thin layer of bone. Osteoclast‐like cells, as present at the interface, had resorbed parts of the cement mass. At locations where Ca‐P cement was resorbed, new bone was formed without loss of integrity between the bone bed and the cement. This demonstrated the osteotransductive property of the cement, i.e., resorption of the material by osteoclast‐like cells, directly followed by the formation of new bone. Histological and histomorphometrical evaluation did not show any significant differences between the Ca‐P cement implanted at the three different liquid/powder ratios. The results indicate that the investigated Ca‐P cement is biocompatible, osteoconductive, as well as osteotransductive and is a candidate material for use as a bone substitute. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res 61: 9–18, 2002
Surface and biological evaluation of hydroxyapatite‐based coatings on titanium deposited by different techniques
Authors: Massaro C. , Baker M. A. , Cosentino F. , Ramires P. A. , Klose S. , Milella E. 
Published: August 2002

AbstractHydroxyapatite coatings have been deposited on titanium cp by plasma spray, sol‐gel, and sputtering techniques for dental implant applications. The latter two techniques are of current interest, as they allow coatings of micrometer dimensions to be deposited. Coating morphology, composition, and structure have been investigated by scanning electron microscopy (SEM), X‐ray photoelectron spectroscopy (XPS) and X‐ray diffraction (XRD). All coatings were homogeneous and exhibited a rough morphology suitable for implant applications. The sputtered (after annealing), plasma spray, and sol‐gel coatings all showed diffraction peaks corresponding to hydroxyapatite. The surface contaminants were observed to be different for the different coating types. The sputtered coatings were found to have a composition most similar to hydroxyapatite; the sol‐gel deposits also showed a high concentration of hydroxyl ions. A discrepancy in the Ca/P ratio was observed for the plasma spray coatings, and a small concentration of carbonate ions was found in the sputter‐deposited coatings. The in vitro cell‐culture studies using MG63 osteoblast‐like cells demonstrated the ability of cells to proliferate on the materials tested. The sol‐gel coating promotes higher cell growth, greater alkaline phosphatase activity, and greater osteocalcin production compared to the sputtered and plasma‐sprayed coatings. © 2001 John Wiley & Sons, Inc. J Biomed Mater Res (Appl Biomater) 58: 651–657, 2001
Bioactive sol‐gel foams for tissue repair
Authors: Sepulveda Pilar , Jones Julian R. , Hench Larry L. 
Published: August 2002

AbstractBioactive glasses are known to have the ability to regenerate bone, but their use has been restricted mainly to powder, granules, or small monoliths. This work reports on the development of sol‐gel foams with potential applications as bone graft implants or as templates for the in vitro synthesis of bone tissue for transplantation. These bioactive foams exhibit a hierarchical structure with interconnected macropores (10–500 μm) and a mesoporous framework typical of gel–glasses (pores of 2–50 nm). The macroporous matrixes were produced through a novel route that comprises foaming of sol‐gel systems. Three glass systems were tested to verify the applicability of this manufacturing route, namely SiO2, SiO2‐CaO, and SiO2‐CaO‐P2O5. This new class of material combines large pores to support vascularization and 3‐D tissue growth with the ability that bioactive materials have to provide bone‐bonding and controlled release of ionic biologic stimuli to promote bone cell proliferation by gene activation. © 2001 Wiley Periodicals, Inc. J Biomed Mater Res 59: 340–348, 2002
Control of wound infections using a bilayer chitosan wound dressing with sustainable antibiotic delivery
Authors: Mi Fwu‐Long , Wu Yu‐Bey , Shyu Shin‐Shing , Schoung Jen‐Yu , Huang Yaw‐Bin , Tsai Yi‐Hung , Hao Jong‐Yun 
Published: August 2002

AbstractA novel bilayer chitosan membrane was prepared by a combined wet/dry phase inversion method and evaluated as a wound dressing. This new type of bilayer chitosan wound dressing, consisting of a dense upper layer (skin layer) and a sponge‐like lower layer (sublayer), is very suitable for use as a topical delivery of silver sulfadiazine (AgSD) for the control of wound infections. Physical characterization of the bilayer wound dressing showed that it has excellent oxygen permeability, that it controls the water vapor transmission rate, and that it promotes water uptake capability. AgSD dissolved from bilayer chitosan dressings to release silver and sulfadiazine. The release of sulfadiazine from the bilayer chitosan dressing displayed a burst release on the first day and then tapered off to a much slower release. However, the release of silver from the bilayer chitosan dressing displayed a slow release profile with a sustained increase of silver concentration. The cultures of Pseudomonas aeruginosa and Staphylococcus aureus in agar plates showed effective antimicrobial activity for 1 week. In vivo antibacterial tests confirmed that this wound dressing is effective for long‐term inhibition of the growth of Pseudomonas aeruginosa and Staphylococcus aureus at an infected wound site. The results in this study indicate that the AgSD‐incorporated bilayer chitosan wound dressing may be a material with potential antibacterial capability for the treatment of infected wounds. © 2001 Wiley Periodicals, Inc. J Biomed Mater Res 59: 438–449, 2002
In vitro generation of differentiated cardiac myofibers on micropatterned laminin surfaces
Authors: McDevitt Todd C. , Angello John C. , Whitney Marsha L. , Reinecke Hans , Hauschka Stephen D. , Murry Charles E. , Stayton Patrick S. 
Published: August 2002

AbstractCardiac muscle fibers consist of highly aligned cardiomyocytes containing myofibrils oriented parallel to the fiber axis, and successive cardiomyocytes are interconnected at their ends through specialized junctional complexes (intercalated disks). Cell culture studies of cardiac myofibrils and intercalated disks are complicated by the fact that cardiomyocytes become extremely flattened and exhibit disorganized myofibrils and diffuse intercellular junctions with neighboring cells. In this study we sought to direct the organization of cultured cardiomyocytes to more closely resemble that found in vivo. Lanes of laminin 5–50 μm wide were microcontact‐printed onto nonadhesive (BSA‐coated) surfaces. Adherent cardiomyocytes responded to the spatial constraints by forming elongated, rod‐shaped cells whose myofibrils aligned parallel to the laminin lanes. Patterned cardiomyocytes displayed a striking, bipolar localization of the junction molecules N‐cadherin and connexin43 that ultrastructurally resembled intercalated disks. When laminin lanes were widely spaced, each lane of cardiomyocytes beat independently, but with narrow‐spacing cells bridged between lanes, yielding aligned fields of synchronously beating cardiomyocytes. Similar cardiomyocyte patterns were achieved on the biodegradable polymer PLGA, suggesting that patterned cardiomyocytes could be used in myocardial tissue engineering. Such highly patterned cultures could be used in cell biology and physiology studies, which require accurate reproduction of native myocardial architecture. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res 60: 472–479, 2002; DOI 10.1008/jbm.1292
IS integration: Your most critical M&A challenge?
Authors: Harrell Horace W. , Higgins Leslee 
Published: August 2002

AbstractOne of the most critical challenges companies face during a merger is integrating their information systems. Seventy‐five percent of merging companies run into problems—causing delays, lost opportunities, and decreased revenues. The authors present a comprehensive strategy for avoiding these pitfalls.© 2002 John Wiley & Sons, Inc.
Effect of trichostatin A on human T cells resembles signaling abnormalities in T cells of patients with systemic lupus erythematosus: A new mechanism for TCR ζ chain deficiency and abnormal signaling*†
Authors: Nambiar Madhusoodana P. , Warke Vishal G. , Fisher Carolyn U. , Tsokos George C. 
Published: August 2002

AbstractTrichostatin A (TSA) is a potent reversible inhibitor of histone deacetylase, and it has been reported to have variable effects on the expression of a number of genes. In this report, we show that TSA suppresses the expression of the T cell receptor ζ chain gene, whereas, it upregulates the expression if its homologous gene Fcε receptor I γ chain. These effects are associated with decreased intracytoplasmic‐free calcium responses and altered tyrosine phosphorylation pattern of cytosolic proteins. Along with these effects, we report that TSA suppresses the expression of the interleukin‐2 gene. The effects of TSA on human T cells are predominantly immunosuppressive and reminiscent of the signaling aberrations that have been described in patients with systemic lupus erythematosus. J. Cell. Biochem. 85: 459–469, 2002. Published 2002 Wiley‐Liss, Inc.
Real‐time quantitative RT‐PCR analysis of human bone marrow stromal cells during osteogenic differentiation in vitro
Authors: Frank Oliver , Heim Manuel , Jakob Marcel , Barbero Andrea , Schäfer Dirk , Bendik Igor , Dick Walter , Heberer Michael , Martin Ivan 
Published: August 2002

AbstractWe developed and used real‐time RT‐PCR assays to investigate how the expression of typical osteoblast‐related genes by human bone marrow stromal cells (BMSC) is regulated by (i) the culture time in medium inducing osteogenic differentiation and (ii) the previous expansion in medium enhancing cell osteogenic commitment. BMSC from six healthy donors were expanded in medium without (CTR) or with fibroblast growth factor‐2 and dexamethasone (FGF/Dex; these factors are known to increase BMSC osteogenic commitment) and further cultivated for up to 20 days with ascorbic acid, β‐glycerophosphate and dexamethasone (these factors are typically used to induce BMSC osteogenic differentiation). Despite a high variability in the gene expression levels among different individuals, we identified the following statistically significant patterns. The mRNA levels of bone morphogenetic protein‐2 (BMP‐2), bone sialo protein‐II (BSP), osteopontin (OP) and to a lower extent cbfa‐1 increased with culture time in osteogenic medium (OM), both in CTR‐ and FGF/Dex‐expanded BMSC, unlike levels of alkaline phosphatase, collagen type I, osteocalcin, and osteonectin. After 20 days culture in OM, BMP‐2, BSP, and OP were more expressed in FGF/Dex than in CTR‐expanded BMSC (mRNA levels were, respectively, 9.5‐, 14.9‐, and 5.8‐fold higher), unlike all the other investigated genes. Analysis of single‐colony‐derived strains of BMSC further revealed that after 20 days culture in OM, only a subset of FGF/Dex‐expanded clones expressed higher mRNA levels of BMP‐2, BSP, and OP than CTR‐expanded clones. In conclusion, we provide evidence that mRNA levels of BMP‐2, BSP, and OP, quantified using real‐time RT‐PCR, can be used as markers to monitor the extent of BMSC osteogenic differentiation in vitro; using those markers, we further demonstrated that only a few subpopulations of BMSC display enhanced osteogenic differentiation following FGF/Dex expansion. J. Cell. Biochem. 85: 737–746, 2002. © 2002 Wiley‐Liss, Inc.
Nuclear apoptotic changes: An overview
Authors: Martelli Alberto M. , Zweyer Marina , Ochs Robert L. , Tazzari Pier Luigi , Tabellini Giovanna , Narducci Paola , Bortul Roberta 
Published: August 2002

AbstractApoptosis is a form of active cell death essential for morphogenesis, development, differentiation, and homeostasis of multicellular organisms. The activation of genetically controlled specific pathways that are highly conserved during evolution results in the characteristic morphological features of apoptosis that are mainly evident in the nucleus. These include chromatin condensation, nuclear shrinkage, and the formation of apoptotic bodies. The morphological changes are the result of molecular alterations, such as DNA and RNA cleavage, post‐translational modifications of nuclear proteins, and proteolysis of several polypeptides residing in the nucleus. During the last five years our understanding of the process of apoptosis has dramatically increased. However, the mechanisms that lead to apoptotic changes in the nucleus have been only partially clarified. Here, we shall review the most recent findings that may explain why the nucleus displays these striking modifications. Moreover, we shall take into consideration the emerging evidence about apoptotic events as a trigger for the generation of autoantibodies to nuclear components. J. Cell. Biochem. 82: 634–646, 2001. © 2001 Wiley‐Liss, Inc.