bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chronic toxicity/oncogenicity study of styrene in cd‐1 mice by inhalation exposure for 104 weeks
Authors: Cruzan George , Cushman Janette R. , Andrews Larry S. , Granville Geoffrey C. , Johnson Keith A. , Bevan Christopher , Hardy Colin J. , Coombs Derek W. , Mullins Pamela A. , Brown W. Ray 
Published: August 2002

AbstractGroups of 70 male and 70 female Charles River CD‐1 mice were exposed whole body to styrene vapor at 0, 20, 40, 80 or 160 ppm 6 h per day 5 days per week for 98 weeks (females) or 104 weeks (males). The mice were observed daily; body weights, food and water consumption were measured periodically, a battery of hematological and clinical pathology examinations were conducted at weeks 13, 26, 52, 78 and 98 (females)/104 (males). Ten mice of each gender per group were pre‐selected for necropsy after 52 and 78 weeks of exposure and the survivors of the remaining 50 of each gender per group were necropsied after 98 or 104 weeks. An extensive set of organs from the control and high‐exposure mice were examined histopathologically, whereas target organs, gross lesions and all masses were examined in all other groups.Styrene had no effect on survival in males. Two high‐dose females died (acute liver toxicity) during the first 2 weeks; the remaining exposed females had a slightly higher survival than control mice. Levels of styrene and styrene oxide (SO) in the blood at the end of a 6 h exposure during week 74 were proportional to exposure concentration, except that at 20 ppm the SO level was below the limit of detection. There were no changes of toxicological significance in hematology, clinical chemistry, urinalysis or organ weights. Mice exposed to 80 or 160 ppm gained slightly less weight than the controls. Styrene‐related non‐neoplastic histopathological changes were found only in the nasal passages and lungs. In the nasal passages of males and females at all exposure concentrations, the changes included respiratory metaplasia of the olfactory epithelium with changes in the underlying Bowman's gland; the severity increased with styrene concentration and duration of exposure. Loss of olfactory nerve fibers was seen in mice exposed to 40, 80 or 160 ppm. In the lungs, there was decreased eosinophilia of Clara cells in the terminal bronchioles and bronchiolar epithelial hyperplasia extending into alveolar ducts. Increased tumor incidence occurred only in the lung. The incidence of bronchioloalveolar adenomas was significantly increased in males exposed to 40, 80 or 160 ppm and in females exposed to 20, 40 and 160 ppm. The increase was seen only after 24 months. In females exposed to 160 ppm, the incidence of bronchiolo‐alveolar carcinomas after 24 months was significantly greater than in the controls. No difference in lung tumors between control and styrene‐exposed mice was seen in the intensity or degree of immunostaining, the location of tumors relative to bronchioles or histological type (papillary, solid or mixed). It appears that styrene induces an increase in the number of lung tumors seen spontaneously in CD‐1 mice. Copyright © 2001 John Wiley & Sons, Ltd.
Selective vulnerability to kainate‐induced oxidative damage in different rat brain regions
Authors: Candelario‐Jalil Eduardo , Al‐Dalain Saied Mohammed , Castillo Rubén , Martínez Gregorio , León Fernández Olga Sonia 
Published: August 2002

AbstractSome markers of oxidative injury were measured in different rat brain areas (hippocampus, cerebral cortex, striatum, hypothalamus, amygdala/piriform cortex and cerebellum) after the systemic administration of an excitotoxic dose of kainic acid (KA, 9 mg kg−1 i.p.) at two different sampling times (24 and 48 h). Kainic acid was able to lower markedly (P < 0.05) the glutathione (GSH) levels in hippocampus, cerebellum and amygdala/piriform cortex (maximal reduction at 24 h). In a similar way, lipid peroxidation, as assessed by malonaldehyde and 4‐hydroxyalkenal levels, significantly increased (P < 0.05) in hippocampus, cerebellum and amygdala/piriform cortex mainly at 24 h after KA. In addition, hippocampal superoxide dismutase (SOD) activity decreased significantly (P < 0.05) with respect to basal levels by 24 h after KA application. On the other hand, brain areas such as hypothalamus, striatum and cerebral cortex seem to be less susceptible to KA excitotoxicity. According to these findings, the pattern of oxidative injury induced by systemically administered KA seems to be highly region‐specific. Further, our results have shown that a lower antioxidant status (GSH and SOD) seems not to play an important role in the selective vulnerability of certain brain regions because it correlates poorly with increases in markers of oxidative damage. Copyright © 2001 John Wiley & Sons, Ltd.
Biocompatibility and in vivo gentamicin release from bioactive sol–gel glass implants
Authors: Meseguer‐Olmo L. , Ros‐Nicolás M. J. , Clavel‐Sainz M. , Vicente‐Ortega V. , Alcaraz‐Baños M. , Lax‐Pérez A. , Arcos D. , Ragel C. V. , Vallet‐Regí M. 
Published: August 2002

AbstractBiomaterial pieces, with suitable osteogenic properties for use in the treatment of bone defects and the capability to avoid bone infections, have been synthesized. These materials are composed exclusively of gentamicin sulfate and bioactive SiO2‐CaO‐P2O5 sol–gel glass (previously synthesized). Implant processing was achieved by uniaxial and isostatic pressure of the components mixture. After implanting the pieces into rabbit femur, we studied (i) the antibiotic release, determining the concentration in proximal and distal bone, liver, kidney, and lung as a function of time; and (ii) the bone growth resulting from the glass reactivity in the biologic environment. The results indicate that the implants are good carriers for local gentamicin release in the osseous tissue, exhibiting excellent biocompatibility and bone integration. Moreover, these implants are able to promote bone growth during their resorption process. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res 61: 458–465, 2002
Adhesion behavior of monocytes, macrophages, and foreign body giant cells on poly (N‐isopropylacrylamide) temperature‐responsive surfaces
Authors: Collier Terry O. , Anderson James M. , Kikuchi Akihiko , Okano Teruo 
Published: August 2002

AbstractMonocyte and macrophage adhesion and foreign body giant cell (FBGC) formation has been observed on surfaces with a wide range of properties. In this study we have utilized novel, temperature‐responsive surfaces (TRS) with dynamic surface properties to investigate inflammatory cell adhesion behavior. With temperature changes, grafted chains of poly‐N‐isopropylacrylamide pass through their lower critical solution temperature (LCST) and can either extend (hydrate), creating a hydrophilic surface at 20°C, or contract (dehydrate), creating a hydrophobic surface at 37°C. Isolated human monocytes and monocyte‐derived macrophages were able to adhere, spread, and form FBGC on the hydrophobic surface. Decreasing the temperature below the lower critical solution temperature induced a change in the surface wettability, creating a hydrophilic surface, that induced a differential detachment of adherent cells that decreased with time, ranging from 98% after 2 h of culture to 30% at day 10. These detached cells remained viable, and were recultured onto TCPS for 3, 7, and 10 days. These novel surfaces allow investigation of the adhesive behavior of adherent inflammatory cells in a temporal manner, and the effects of surface conformation and wettability changes on cell adhesion and detachment. © 2001 Wiley Periodicals, Inc. J Biomed Mater Res 59: 136–143, 2002
Hydroxylapatite with substituted magnesium, zinc, cadmium, and yttrium. II. Mechanisms of osteoblast adhesion
Authors: Webster Thomas J. , Ergun Celaletdin , Doremus Robert H. , Bizios Rena 
Published: August 2002

AbstractThe present in vitro study investigated osteoblast adhesion on hydroxylapatite (HA) doped with either cadmium (Cd), zinc (Zn), magnesium (Mg), or yttrium (Y). Compared with any other dopant tested in the present study, osteoblast adhesion was significantly (p < 0.05) greater on HA doped with Y after 4 h; in addition, osteoblast adhesion increased with concentration (2–7 mol%) of Y in HA. The findings that HA doped with greater amounts of Y adsorbed higher concentrations of calcium and, subsequently, of vitronectin and collagen (proteins known to mediate osteoblast adhesion), but not of albumin, laminin, and fibronectin, may explain the observed enhanced adhesion of osteoblasts on these substrates. Interactions (i.e., adsorption and configuration/bioactivity) of vitronectin and collagen may have been promoted by increased porosity of doped HA. Through doping with Y, the present study provided the first evidence that HA can be synthesized and processed with improved cytocompatibility properties for osteoblast adhesion, and thus offered essential information for the design of novel proactive bioceramics. Proactive bioceramics which elicit specific, timely, and desired responses from surrounding cells and tissues are necessary for improving bonding of orthopaedic/dental implants to juxtaposed bone; such osseointegration will, undoubtedly, enhance implant efficacy. © 2001 Wiley Periodicals, Inc. J Biomed Mater Res 59: 312–317, 2002
A comparison of 60, 70, and 90 kDa stress protein expression in normal rat NRK‐52 and human HK‐2 kidney cell lines following in vitro exposure to arsenite and cadmium alone or in combination
Authors: Madden Emily F. , Akkerman Miriam , Fowler Bruce A. 
Published: August 2002

AbstractArsenite and cadmium are two potent nephrotoxicants and common Superfund site elements. These elements are included among the stress protein inducers, but information regarding relationships between toxicity produced by combinations of these agents to the stress protein response is lacking. In this study, the immortalized cell lines normal rat kidney NRK‐52E and human kidney HK‐2 were exposed in vitro to arsenite (As3+), cadmium (Cd2+), or to equimolar As3+ plus Cd2+ mixture combinations for 3 and 5 h over a concentration range of 0.1–100 μM. After a 12‐h recovery period, cultured cells were then evaluated for expression of the 60, 70, and 90 kDa major stress protein families. Results indicated that expression of stress proteins varied depending on the species of kidney cells exposed, the exposure concentrations, and the length of exposure to each element on an individual basis and for combined mixtures. For the HK‐2 kidney cell line, increased levels of the 70 kDa stress protein was observed for single and combined element exposures whereas there was no change or a decrease of stress proteins 60 and 90 kDa. Increased 70 kDa expression was observed for 10‐μM doses of single elements and for a lower dose of 1 μM of the As plus Cd mixture at 3‐ and 5‐h exposures. NRK‐52 kidney cells exposed to equivalent doses of As3+ and Cd2+ alone or in combination showed increased levels of all stress proteins 60, 70, and 90 kDa. This increase was seen for 10 μM of the As plus Cd mixture at 3 h whereas for single element exposures, increased stress protein levels were generally observed for the 100‐μM doses. At 5 h‐ exposure, 60 and 90 kDa levels increased for 10 μM of Cd2+ and 60 kDa levels increased for 1 μM of As3+. However, exposures to 10 μM of the As plus Cd mixture decreased 60 kDa protein expression to control levels at 5 h. For both kidney cell lines, there was a decrease in the stress protein expression levels for all three stress protein families for 100‐μM doses of the mixture combination for 3‐ and 5‐h exposures. These data indicate a dose‐ and combination‐related correlation between depression of the stress protein response and the onset of overt cellular toxicity and/or cell death. The threshold for these changes was cell line specific. © 2002 Wiley Periodicals, Inc. J Biochem Mol Toxicol 16:24–32, 2002; DOI 10.1002/jbt.10015
Mammalian DNA methyltransferases show different subnuclear distributions
Authors: Margot Jean B. , Cardoso M. Cristina , Leonhardt Heinrich 
Published: August 2002

AbstractIn mammalian cells, DNA methylation patterns are precisely maintained after DNA replication with defined changes occurring during development. The major DNA methyltransferase (Dnmt1) is associated with nuclear replication sites during S‐phase, which is consistent with a role in maintenance methylation. The subcellular distribution of the recently discovered de novo DNA methyltransferases, Dnmt3a and Dnmt3b, was investigated by immunofluorescence and by epitope tagging. We now show that both Dnmt3a and Dnmt3b are distributed throughout the nucleoplasm but are not associated with nuclear DNA replication sites during S‐phase. These results suggest that de novo methylation by Dnmt3a and Dnmt3b occurs independently of the replication process and might involve an alternative mechanism for accessing the target DNA. The different subcellular distribution of mammalian DNA methyltransferases might thus contribute to the regulation of DNA methylation. J. Cell. Biochem. 83: 373–379, 2001. © 2001 Wiley‐Liss, Inc.
A fast pairwise evaluation of molecular surface area
Authors: Vasilyev Vladislav , Purisima Enrico O. 
Published: August 2002

AbstractA fast and general analytical approach was developed for the calculation of the approximate van der Waals and solvent‐accessible surface areas. The method is based on three basic ideas: the use of the Lorentz transformation formula, a rigid‐geometry approximation, and a single fitting parameter that can be refitted on the fly during a simulation. The Lorentz transformation equation is used for the summation of the areas of an atom buried by its neighboring contacting atoms, and implies that a sum of the buried pairwise areas cannot be larger than the surface area of the isolated spherical atom itself. In a rigid‐geometry approximation we numerically calculate and keep constant the surface of each atom buried by the atoms involved in 1‐2 and 1‐3 interactions. Only the contributions from the nonbonded atoms (1‐4 and higher interactions) are considered in terms of the pairwise approximation. The accuracy and speed of the method is competitive with other pairwise algorithms. A major strength of the method is the ease of parametrization. © 2002 Wiley Periodicals, Inc. J Comput Chem 23: 737–745, 2002
Divergence and convergence of TGF‐β/BMP signaling
Authors: Miyazono Kohei , Kusanagi Kiyoshi , Inoue Hirofumi 
Published: August 2002

AbstractThe transforming growth factor‐β (TGF‐β) superfamily includes more than 30 members which have a broad array of biological activities. TGF‐β superfamily ligands bind to type II and type I serine/threonine kinase receptors and transduce signals via Smad proteins. Receptor‐regulated Smads (R‐Smads) can be classified into two subclasses, i.e. those activated by activin and TGF‐β signaling pathways (AR‐Smads), and those activated by bone morphogenetic protein (BMP) pathways (BR‐Smads). The numbers of type II and type I receptors and Smad proteins are limited. Thus, signaling of the TGF‐β superfamily converges at the receptor and Smad levels. In the intracellular signaling pathways, Smads interact with various partner proteins and thereby exhibit a wide variety of biological activities. Moreover, signaling by Smads is modulated by various other signaling pathways allowing TGF‐β superfamily ligands to elicit diverse effects on target cells. Perturbations of the TGF‐β/BMP signaling pathways result in various clinical disorders including cancers, vascular diseases, and bone disorders. © 2001 Wiley‐Liss, Inc.
Endoglin: An accessory component of the TGF‐β‐binding receptor‐complex with diagnostic, prognostic, and bioimmunotherapeutic potential in human malignancies
Authors: Fonsatti Ester , Vecchio Luigi Del , Altomonte Maresa , Sigalotti Luca , Nicotra Maria Rita , Coral Sandra , Natali Pier Giorgio , Maio Michele 
Published: August 2002

AbstractEndoglin (CD105) is a cell membrane glycoprotein over‐expressed on highly proliferating endothelial cells in culture, and on endothelial cells of angiogenetic blood vessels within benign and malignant tissues. CD105 binds several factors of the Transforming Growth Factor (TGF)‐β superfamily, and its over‐expression modulates cellular responses to TGF‐β1. The complex of experimental findings accumulated in the last few years strongly indicate that CD105 is a powerful marker of angiogenesis, and that it might play a critical role in the pathogenesis of vascular diseases and in tumor progression. In this paper, we will review the structural, biological and functional features of CD105, as well as its distribution within normal and neoplastic tissues, emphasizing its foreseeable role as a molecular target for new diagnostic and bioimmunotherapeutic approaches in human malignancies. © 2001 Wiley‐Liss, Inc.
On‐line monitoring of wastewater quality: a review
Authors: Bourgeois Wilfrid , Burgess Joanna E , Stuetz Richard M 
Published: August 2002

AbstractReal‐time monitoring of wastewater quality remains an unresolved problem to the wastewater treatment industry. In order to comply with increasingly stringent environmental regulations, plant operators as well as instrument manufacturers have expressed the need for new standards and improved comparability and reliability of existing techniques. A review of currently available methods for monitoring global organic parameters (BOD, COD, TOC) is given. The study reviews both existing standard techniques and new innovative technologies with the focus on the sensors' potential for on‐line and real‐time monitoring and control. Current developments of biosensors, optical sensors and sensor arrays as well as virtual sensors for the monitoring of wastewater organic load are presented and the interests and limitations of these techniques with respect to their application to the wastewater monitoring are discussed.© 2001 Society of Chemical Industry
Preparation and use of a mesoporous silicate material for the removal of tetramethyl ammonium hydroxide (TMAH) from aqueous solution
Authors: Kelleher Brian P , Doyle Aidan M , O'Dwyer Thomas F , Hodnett Benjamin K 
Published: August 2002

AbstractA cubic mesoporous silicate (CMS) was prepared, characterised, and assessed as an adsorbent for tetramethyl ammonium hydroxide (TMAH) from aqueous solution. The adsorption process was studied as a function of temperature and time. Sorption closely followed the Langmuir model. The adsorption of TMAH on CMS was endothermic and kinetic studies suggest that the overall rate of adsorption was pseudo‐second‐order. Pore diffusion effects contribute to limiting the overall rate of adsorption while at lower initial TMAH concentrations, film diffusion becomes more important. Desorption studies were carried out using water and methanol. Methanol was the superior desorbing agent.© 2001 Society of Chemical Industry
Nitric oxide: Relation to integrity, injury, and healing of the gastric mucosa
Authors: Calatayud Sara , Barrachina Dolores , Esplugues Juan V. 
Published: August 2002

AbstractNitric oxide (NO) plays a multifaceted role in mucosal integrity. The numerous functions of NO and the double‐edged role played by NO in most of them provide a great complexity to the NO action. The three enzymatic sources of NO, neuronal NO‐synthase (nNOS), endothelial NOS (eNOS), and inducible NOS (iNOS), have been characterised in the gastrointestinal tract. The protective properties of the NO derived from constitutive NO‐synthases (eNOS and nNOS) have already been well established. Less clear is the role assigned to iNOS. The simplistic initial view of low levels of NO synthesised by constitutive NOS being protective while exaggerated NO levels after iNOS induction leading irremediably to cytotoxicity is being questioned by new evidence. As initially reported for constitutive NOS, iNOS activity may be associated to reduced leukocyte‐endothelium interaction and platelet aggregation as well as protection of mucosal microcirculation. Moreover, iNOS activity may be important to resolve inflammation by increasing apoptosis in inflammatory cells. It is entirely possible that a low level of expression of iNOS will reflect a positive host‐defense response to challenge, but that exaggerated or uncontrolled expression of iNOS itself becomes detrimental. There is no doubt about the protective role of NO in physiological conditions. However, when the mucosa is threatened, the role of NO becomes multiple and the final effect will probably depend on the nature of the insult, the environment involved, and the interaction with other mediators. Microsc. Res. Tech. 53:325–335, 2001. © 2001 Wiley‐Liss, Inc.
NO message from muscle
Authors: Grozdanovic Zarko 
Published: August 2002

AbstractThe synthesis of the free radical gas nitric oxide (NO) is catalyzed by the enzyme NO synthase (NOS). NOS converts arginine and molecular oxygen to NO and citrulline in a reaction that requires NADPH, FAD, FMN, and tetrahydrobiopterin as cofactors. Three types of NOS have been identified by molecular cloning. The activity of the constitutively expressed neuronal NOS (nNOS) and endothelial NOS (eNOS) is Ca2+/calmodulin‐dependent, whereas that the inducible NOS (iNOS) is Ca2+‐insensitive. The predominant NOS isoform in skeletal muscle is nNOS. It is present at the sarcolemma of both extra‐ and intrafusal muscle fibers. An accentuated accumulation of nNOS is found in the endplate area. This strict sarcolemmal localization of nNOS is due its association with the dystrophin‐glycoprotein complex, which is mediated by the syntrophins. The activity of nNOS in skeletal muscle is regulated by developmental, myogenic, and neurogenic influences. NO exerts several distinct effects on various aspects of skeletal muscle function, such as excitation‐contraction coupling, mitochondrial energy production, glucose metabolism, and autoregulation of blood flow. Inside the striated muscle fibers, NO interacts directly with several classes of proteins, such as soluble guanylate cyclase, ryanodine receptor, sarcoplasmic reticulum Ca2+‐ATPase, glyceraldehyde‐3‐phosphate dehydrogenase, and mitochondrial respiratory chain complexes, as well as radical oxygen species. In addition, NO produced and released by contracting muscle fibers diffuses to nearby arterioles where it acts to inhibit reflex sympathetic vasoconstriction. Microsc. Res. Tech. 55:148–153, 2001. © 2001 Wiley‐Liss, Inc.
Temperature effects and genotype‐temperature interactions on sex determination in the European sea bass (Dicentrarchus labrax L.)
Authors: Saillant Eric , Fostier Alexis , Haffray Pierrick , Menu Bruno , Thimonier Jacques , Chatain Béatrice 
Published: August 2002

AbstractThe effect of temperature on sex‐ratios in 27 families of sea bass reared in the same tank from the fertilization stage onward was investigated. An excess of males (68%) was found in the groups that were reared at high temperature (mean�±�standard deviation: 20�±�1°C) until they reached the mean size of 8.1 cm (Standard Length, 149 days post‐fertilization [p.f.]). Masculinization was higher (89% of males) in the groups maintained at low temperature (13°C), from fertilization to a mean length of 6.5�cm (346 days p.f.). Shifts from high to low temperature at 8.1�cm and from low to high temperature at 6.5�cm had no consequence on the sex‐ratio. The percentage of males showing intratesticular oocytes was higher at low temperature (63%) than at high temperature (36%), suggesting that these males may be sensitive fish that have been masculinized by environmental factors. Fish sampled in the groups reared at high (2,200 fish) and low (500 fish) temperature were genotyped on three microsatellite loci. This allowed them to be assigned to the breeders used in the crossing design, thus permitting an analysis of parental influence on sex‐ratios. In groups reared at high temperature, both parents had a significant additive effect on the percentage of females, and the interaction between sire and dam was not significant. Genotype temperature interactions were also detected and their existence suggests the interesting possibility of selecting nonsensitive genotypes in breeding programs. J. Exp. Zool. 292:494–505, 2002. © 2002 Wiley‐Liss, Inc.