bluuebunny/crossref_metadata_2025_split huggingface dataset:
P2P‐R protein localizes to the nucleolus of interphase cells and the periphery of chromosomes in mitotic cells which show maximum P2P‐R immunoreactivity
Authors: Gao Sizhi , Witte Michael M. , Scott Robert E. 
Published: August 2002

AbstractP2P‐R is a nuclear protein that can bind both p53 and Rb1. Its functions include roles in the control of RNA metabolism, apoptosis, and p53‐dependent transcription. The expression of P2P‐R also is repressed in G1 arrested terminally differentiated cells. The current studies therefore evaluated if P2P‐R undergoes cell cycle‐associated changes in its abundance and/or localization. Western blots show that relative to G0 quiescent cells, P2P‐R protein levels are higher in populations of G2/M cells prepared by the physiological parasynchronization technique of serum deprivation followed by serum stimulation. More striking is the > 10‐fold enrichment of P2P‐R protein in specimens of highly purified mitotic cells prepared by the mitotic shake‐select technique, or by synchrony with the mitotic spindle disruption agents nocodazole or vinblastine. These changes in P2P‐R protein occur without a concomitant change in P2P‐R mRNA expression suggesting that P2P‐R immunoreactivity increases during mitosis. Confocal microscopy next established the localization of P2P‐R to nucleoli in interphase cells and at the periphery of chromosomes in mitotic cells that lack nucleoli. The high levels of P2P‐R localized to the periphery of chromosomes in mitotic cells suggest that P2P‐R shares characteristics with other nucleolar proteins that associate with the periphery of chromosomes during mitosis. These include: nucleolin, B23, Ki67, and fibrillarin. J. Cell. Physiol. 191: 145–154, 2002. © 2002 Wiley‐Liss, Inc.
Effect of pre‐adsorbed proteins on attachment, proliferation, and function of endothelial cells
Authors: Balcells Mercedes , Edelman Elazer R. 
Published: August 2002

AbstractAs certain proteins control cell adhesion, it has been hoped that cell transplantation and tissue engineering could be augmented by pre‐adsorption of specific proteins to biological or synthetic surfaces. The questions that remain, however, are whether such proteins can affect cell production as well as adhesion, and if so, whether in a protein‐specific manner. We examined the adhesion and the biochemical secretion of bovine aortic endothelial cells (BAEC) on tissue culture polystyrene (TCPS) discs coated with fibronectin (Fn), laminin (Ln), or gelatin. The three coating proteins nonspecifically promote sub‐confluent and post‐confluent endothelial cell production of total protein up to 2.5‐fold of the reference value. Total soluble glycosaminoglycan (GAG) production slightly increased with the different coatings only at low cell density. In contrast, Ln and Fn, not gelatin, drastically enhanced post‐confluent BAEC production of prostaglandin (PGI2). However, antibody‐blockage of the α5 integrin, constituent of the Fn receptor in BAEC, appeared to inhibit the upregulation of PGI2 production observed on Fn‐coated surfaces. The results indicate that the cell adhesion mediators used as coating agents dictate cell biological production as well as adhesion and proliferation. J. Cell. Physiol. 191: 155–161, 2002. © 2002 Wiley‐Liss, Inc.
Branched‐chain amino acids: A role in skeletal muscle proteolysis in catabolic states?
Authors: Busquets Sílvia , Alvarez Belén , López‐Soriano Francisco J. , Argilés Josep M. 
Published: August 2002

AbstractA 48‐h starvation period resulted in a great increase in muscle proteolysis—as measured following the release of tyrosine into the medium—in incubated isolated rat extensor digitorum longus (EDL) muscles. We have quantified the contribution of the different proteolytic systems to the increased protein degradation and observed a considerable activation in the ATP‐dependent proteolytic (60%) and in the calcium‐dependent (125%) systems, while no increases were observed in lysosomal proteolysis. The addition of 10 mM leucine to the incubation medium did not result in any changes in either total proteolytic rate or the activity rates of any of the different systems studied. In addition, the presence of the amino acid did not influence the levels of mRNA for the different genes studied—ubiquitin, C8 proteasome subunit, E2 conjugating enzyme, m‐calpain, and cathepsin B. In a similar way, as observed during starvation, tumor growth resulted in increased protein degradation in incubated isolated EDL muscles from animals bearing the Yoshida AH‐130 ascites hepatoma. The increased rate of protein degradation affected all the proteolytic systems studied: ATP‐ and calcium‐dependent and lysosomal. Finally, leucine addition (10 mM), although not able to revert the increased proteolytic rate, resulted in a decrease in the gene expression for ubiquitin, C8 proteasome subunit and cathepsin B. © 2002 Wiley‐Liss, Inc.
Effects of endothelins on hepatic stellate cell synthesis of endothelin‐1 during hepatic wound healing
Authors: Shao Rong , Rockey Don C. 
Published: August 2002

AbstractEndothelin‐1 production is increased after liver injury and the subsequent wounding response. Further, endothelin‐1 has prominent effects on hepatic stellate cells (key effectors of the hepatic wounding response), including on collagen synthesis, proliferation, and expression of smooth muscle proteins. We tested the hypothesis that endothelins (ETs) may regulate endothelin‐1 production during hepatic wounding, and have investigated potential mechanisms underlying this process. Studies were performed on isolated stellate cells from normal and injured livers; in addition, potential autocrine effects of ET were assessed in vivo using an ET receptor antagonist in a model of liver injury. In stellate cells isolated from either normal or injured rat livers, ET receptor stimulation with endothelin‐3 or sarafotoxin S6C (preferential ETB agonists) caused a dose‐dependent increase in endothelin‐1 production. Additionally, administration of a mixed ET antagonist in vivo during injury led to reduced stellate cell production of endothelin‐1. The mechanism by which ETs stimulated endothelin‐1 in this system appeared to be through upregulation of ET converting enzyme‐1 (which converts precursor ET to mature peptide), rather than by modulation of precursor endothelin‐1. We conclude that during liver injury and wound healing, stellate cell endothelin‐1 production is, at least partially, stimulated by ETs via autocrine mechanisms that occur at the level of ET converting enzyme‐1. © 2002 Wiley‐Liss, Inc.
Kinetics of endomitosis in primary murine megakaryocytes
Authors: Carow Catherine E. , Fox Norma E. , Kaushansky Kenneth 
Published: August 2002

AbstractMegakaryocytes (MKs) develop from diploid progenitor cells via successive rounds of DNA synthesis in the absence of cell division, a process termed endomitosis (EnM). While the mechanism underlying EnM is not known, studies in yeast and leukemic cell lines have suggested that it may be due to reduced levels of cyclin B1 or cdc2, leading to a decrease in mitotic kinase activity. Using flow cytometry to study EnM highly purified marrow‐derived MK precursors, we found that: (1) on average, 36% of 8N‐32N MKs expressed abundant cyclin B during G2/M. The percentage of cells in G2/M decreased in >64N MKs, suggesting the limit of EnM, (2) the level of cyclin B per G2/M MK increased linearly with ploidy, (3) cyclin B expression oscillated normally in polyploid MKs, (4) MPM‐2, a phosphoepitope created by the action of mitotic kinases and specific to M‐phase cells, was expressed in a significant fraction of polyploid MKs, and (5) there was an apparent increase of cyclin B in G1‐phase in polyploid MKs. This study provides the first qualitative kinetic data regarding the cell cycle status of MKs within individual ploidy classes. It also demonstrates the feasibility of using anti‐cyclin B antibody and flow cytometry to resolve G1 from G2/M populations in polyploid MKs. Finally, these findings establish that neither a relative nor absolute deficiency of mitotic kinase components is responsible for EnM, suggesting that the departure from normal cell division kinetics seen in polyploid MKs is likely due to alterations in other cell cycle regulators. © 2001 Wiley‐Liss, Inc.
An automated multi‐unit composting facility for biodegradability evaluations
Authors: Jayasekara Ranjith , Lonergan Greg T , Harding Ian , Bowater Ian , Halley Peter , Christie Gregor B 
Published: August 2002

AbstractA system has been developed for studying the biodegradation of natural and synthetic polymeric material. The system is based on standard methods developed by the European Committee for Standardisation (CEN TC 261) (ISO/DIS 14855) and the American Society of Testing Materials, ‘ASTM Standard Test Method for Determining Aerobic Biodegradation of Plastic Materials under Controlled Composting Conditions’ (ASTM D 5338‐92). A new low‐cost compost facility has been used which satisfies the requirements of these standards. The system has been automated for data collection and has been run under the conditions specified by the standards. In the system, cellulose, newspaper and two starch‐based polymers were treated with compost in a series of 3 dm3 vessels at 52 °C and under conditions of optimum moisture and pH. The degradation was followed over time by measuring the amount of carbon released as carbon dioxide.© 2001 Society of Chemical Industry
Removal of organic contaminants in paper pulp effluents by AOPs: an economic study
Authors: Pérez Montserrat , Torrades Francesc , Domènech Xavier , Peral José 
Published: August 2002

AbstractThe degradation of the organic content of a bleaching Kraft mill effluent was carried out using Advanced Oxidation Processes (AOPs). The study was focused on the identification of the AOP, or combination of AOPs, that showed the highest efficiency together with the lowest cost. Direct UV photolysis (UV), TiO2 assisted‐photocatalysis (TiO2/UV), Fenton, Fenton‐like, and photo‐Fenton reactions (Fe(II)/H2O/UV), UV‐assisted ozonation (O3/UV) and addition of Fe2+ and/or H2O2 to the TiO2/UV and the O3/UV systems, were used for the degradation of a conventional cellulose bleaching effluent. The effluent was characterized by the general parameters TOC, COD and color, and analyzed for chlorinated low molecular weight compounds using GC–MS. The costs of the systems per unit of TOC reduction were compared. Fenton, Fenton‐like and photo‐Fenton reactions achieved better levels of TOC degradation than photocatalysis and with lower cost's than photocatalytic treatments. Ozonation is an effective but rather expensive process. The use of UVA light, however, increased the effectiveness of ozonation with a significant decrease (>25%) in the operational cost.© 2002 Society of Chemical Industry
Two‐phase anaerobic digestion processes: a review
Authors: Demirel Burak , Yenigün Orhan 
Published: August 2002

AbstractThis review provides a detailed comparative summary of the recent and current research activities in the area of two‐phase anaerobic digestion processes. The acid phase and the methane phase are first evaluated, individually, from microbiological, kinetic and modelling, process optimization, operation and control, inhibition, and toxicity points of view. The overall process performance is subsequently evaluated as a whole. Finally, areas requiring further research are determined.© 2002 Society of Chemical Industry
Technique of color Doppler quantification of vascularity in transplanted kidneys
Authors: Gruenewald Simon , Skerrett David , Dolimier Damien , Nankivell Brian 
Published: August 2002

AbstractA new technique for the quantification of vascularity based on the analysis of color Doppler images is described. We utilized velocity information obtained directly from cineloops transferred to a computer for off‐line analysis. This methodology was used in transplanted kidneys to assess parenchymal vascularity on the basis of percentage color pixel density and mean flow velocity in mid‐kidney cross‐sectional regions of interest and the distance from the most peripheral color pixels to the capsule of the kidney. Other color Doppler quantitative methods have lacked reproducibility, and therefore before evaluation of the clinical usefulness of this technique, intraobserver reproducibility and interobserver reliability were assessed in 42 patients; no statistically significant variation was demonstrated. In 13 patients with normally functioning transplants, the mean maximum color pixel density was 34.7±13.4%, the mean flow velocity was 5.2±0.9 cm/second, and the mean distance to the capsule was 3.3±1.1 mm. © 2002 Wiley Periodicals, Inc. J Clin Ultrasound 30:151–157, 2002; DOI 10.1002/jcu.10044
Detection and differential diagnosis of hepatic masses using pulse inversion harmonic imaging during the liver‐specific late phase of contrast enhancement with levovist
Authors: Yücel Cem , Özdemir Hakan , Gürel Safiye , Özer Şule , Araç Mehmet 
Published: August 2002

AbstractPurposeThe purpose of this study was to investigate whether late‐phase pulse inversion harmonic imaging (PIHI) increases conspicuity in hepatic masses, helps to differentiate benign from malignant lesions, and demonstrates a greater number of and smaller metastatic lesions than do conventional (fundamental) sonography and helical CT.MethodsThirty patients (17 women and 13 men; age range, 35–77 years; mean age, 54 years) with known or suspected liver masses were evaluated using both fundamental sonography and contrast‐enhanced PIHI during the liver‐specific late phase of Levovist. The patients also underwent contrast‐enhanced triphasic helical CT examinations within 1 week after sonography. In 4 of the patients, gadolinium‐enhanced MRI was also performed as a part of their clinical work‐up.ResultsThe increase in the lesions' conspicuity on PIHI compared with fundamental sonography was significantly greater in malignant lesions than in benign lesions (p< 0.001). An echogenic rim was observed on PIHI in 8 (53%) of 15 malignant lesions. The mean number of metastatic lesions visualized on PIHI (5.5 ± 5.3) was significantly higher than the mean number visualized on fundamental sonography (2.5 ± 2.1, p < 0.05). Although lesions as small as 3 mm were observed on PIHI, the mean sizes of the smallest lesions demonstrated using fundamental sonography, PIHI, and helical CT were not significantly different.ConclusionsLate‐phase PIHI is a useful technique for characterizing hepatic lesions and demonstrating both a greater number of and smaller metastases. It may help to differentiate benign from malignant liver masses and may obviate unnecessary and expensive further imaging. © 2002 Wiley Periodicals, Inc. J Clin Ultrasound 30:203–212, 2002; Published online in Wiley InterScience (www.interscience. wiley.com). DOI: 10.1002/jcu.10053
Structure and function of endothelial caveolae
Authors: Stan Radu‐Virgil 
Published: August 2002

AbstractCaveolae are spherical invaginations of the plasma membrane and associated vesicles that are found at high surface densities in most cells, endothelia included. Their structural framework has been shown to consist of oligomerized caveolin molecules interacting with cholesterol and sphingolipids. Caveolae have been involved in many cellular functions such as endocytosis, signal transduction, mechano‐transduction, potocytosis, and cholesterol trafficking. Some confusion still persists in the field with respect to the relationship between caveolae and the lipid rafts, which have been involved in many of the above functions. In addition to all these, endothelial caveolae have been involved in capillary permeability by their participation in the process of transcytosis. This short review will focus on their structure and components, methods used to determine these components, and the role of caveolae in the transendothelial exchanges between blood plasma and the interstitial fluid. Microsc. Res. Tech. 57:350–364, 2002. © 2002 Wiley‐Liss, Inc.
Identification and functional characterization of hypoxia‐inducible factor 2α from the estuarine teleost, Fundulus heteroclitus: Interaction of HIF‐2α with two ARNT2 splice variants
Authors: Powell Wade H. , Hahn Mark E. 
Published: August 2002

AbstractThe hypoxia‐inducible factors (HIFs) are dimeric transcription factors that mediate changes in gene expression during adaptation of animals to oxygen stress. Both alpha (HIFα) and beta (ARNT) subunits are members of the basic helix‐loop‐helix/Per‐ARNT‐Sim family of proteins. Mammals have at least three different HIF‐α subunits, paralogous proteins expressed in tissue‐specific fashion (HIF‐1α, HIF‐2α, and HIF‐3α). However, the diversity and functional properties of teleost HIFs are poorly understood. In efforts to characterize mechanisms of hypoxia adaptation in estuarine fish, we have isolated cDNAs encoding HIF subunits from Fundulus heteroclitus (Atlantic killifish or mummichog), including a HIF‐2α homolog and ARNT2alt, a splice variant of ARNT2 that contains an additional exon encoding 16 amino acids near the amino terminus. HIF‐2α protein synthesized in vitro binds cognate DNA elements in concert with either Fundulus ARNT2 splice variant or murine ARNT1. HIF‐2α, ARNT2, and ARNT2alt mRNAs are expressed in all organs examined. The HIF‐2α cDNA encodes a protein of 96.4 kDa, sharing 53–54% identity with mammalian and avian orthologs. The oxygen‐dependent degradation domain, however, exhibits substantial divergence from well‐conserved mammalian sequences, suggesting the possibility of important functional differences, perhaps in the sensitivity to induction of activity by hypoxia. Hypoxia‐tolerant fishes such as F. heteroclitus represent a unique opportunity for the study of functional and evolutionary aspects of adaptation to hypoxia at the molecular, cellular, and organismal levels. This study extends the understanding of hypoxia signaling in fish, the evolution and diversity of HIF function, and the evolution of the PAS family of proteins. J. Exp. Zool. (Mol. Dev. Evol.) 294:17–29, 2002. © 2002 Wiley‐Liss, Inc.
Immunocytochemical localization of hydroxyindole‐o‐methyltransferase (HIOMT) in the brain of Myoisophagos lacteus (Nemertea: Heteronemertea: Lineidae)
Authors: Arnoult Fabrice , Vernet Guy 
Published: August 2002

AbstractIn an attempt to identify the brain structures that synthesize melatonin and that probably mediate the photoperiodic response of the heteronemertean Myoisophagos lacteus, we utilized immunocytochemical techniques and employed immunoglobulins directed against hydroxyindole‐O‐methyltransferase (HIOMT, EC 2.1.1.4). This enzyme catalyzes the last step of melatonin biosynthesis. In immunocytochemically treated head sections of Myoisophagos lacteus, antibodies labelled a few cells in the dorsal region of the dorsal cerebral ganglia. Previous studies have shown that melatonin is present both in the brain and eyes of this nemertean species and that melatonin is involved in control of the worm reproduction. Other studies have demonstrated the presence of photoreceptor‐like cells in the same region of the worm brain that showed HIOMT immunostaining. Therefore, anatomical findings of the present study, coupled with results of previous works, provide strong evidence that this region of the worm brain houses a photoperiodic receptor involved in melatonin biosynthesis. J. Exp. Zool. 290:156–162, 2001. © 2001 Wiley‐Liss, Inc.
Differential scanning calorimetry studies of intraembryonic freezing and cryoprotectant penetration in zebrafish (Danio rerio) embryos
Authors: Liu Xiang‐Hong , Zhang Tiantian , Rawson David M. 
Published: August 2002

AbstractNucleation temperatures of intraembryonic water and cryoprotectant penetration in zebrafish embryos were studied using differential scanning calorimetry. The effects of embryo developmental stage, dechorionation, partial removal of yolk, cooling rate, and cryoprotectant treatment on the temperatures of intraembryonic freezing were investigated. Embryo stages were found to have a significant effect on the nucleation temperatures of intact embryos. Freeze onset temperatures of –11.9 ± 1.5, –15.6 ± 0.3, and –20.5 ± 0.1°C were obtained for intact embryos at 6‐somite, prim‐6, and high‐pec stages, respectively. After dechorionation, the freeze onset temperatures of intraembryonic water shifted to significantly lower temperatures, being –23.5 ± 0.8, –18.7 ± 0.7, –24.9 ± 0.8°C for 6‐somite, prim‐6, and high‐pec stages, respectively. Yolk‐reduced high‐pec stage embryos showed significantly lower nucleation temperatures with an average onset at –27.9 ± 0.4°C. The effect of cryoprotectant treatment on the nucleation temperatures of intraembryonic water varies among different embryo stages and different cryoprotectants. Thirty‐minute treatment with 2 M methanol significantly decreased the nucleation temperatures of dechorionated 6‐somite embryos whilst no temperature decrease was observed for prim‐6 or yolk‐reduced high‐pec embryos. Thirty‐minute exposure to 1 M propylene glycol did not significantly affect the nucleation temperatures of dechorionated 6‐somite, prim‐6, or yolk‐reduced high‐pec embryos. In order to increase the permeability of embryos to cryoprotectants, the yolk sacs of dechorionated embryos at 6‐somite or prim‐6 embryos were punctured with a sharp micro‐needle before exposure to cryoprotectants. The punctured prim‐6 embryos showed significantly lower temperatures of intraembryonic freezing after 30 min of exposure to 2 M methanol following the multi‐punctures. The nucleation temperatures of punctured 6‐somite or prim‐6 embryos were also decreased significantly after exposure to 1 M propylene glycol for 30 min. These results suggested that in intact embryos, intraembryonic freezing appeared to be seeded by the external ice in the perivitelline fluid and that in dechorionated embryos (in the absence of external water) intraembryonic freezing was more likely a consequence of heterogeneous nucleation. Methanol was demonstrated to show a limited degree of penetration into prim‐6 stage embryos, but it did not penetrate later‐stage embryos such as prim‐6 and yolk‐reduced high‐pec. No propylene glycol permeation was observed for embryos at all stages. However, multi‐punctures of yolk resulted in the permeation of both cryoprotectants into prim‐6 embryos and propylene glycol permeation into 6‐somite embryos. These findings may have important implications in overcoming the problem associated with the low membrane permeability of zebrafish embryos to cryoprotectants. J. Exp. Zool. 290:299–310, 2001. © 2001 Wiley‐Liss, Inc.
Current problems with the zootype and the early evolution of Hox genes
Authors: Schierwater Bernd , Desalle Rob 
Published: August 2002

Abstract“Hox cluster type” genes have sparked intriguing attempts to unite all metazoan animals by a shared pattern of expression and genomic organization of a specific set of regulatory genes. The basic idea, the zootype concept, claims the conservation of a specific set of “Hox cluster type genes” in all metazoan animals, i.e., in the basal diploblasts as well as in the derived triploblastic animals. Depending on the data used and the type of analysis performed, different opposing views have been taken on this idea. We review here the sum of data currently available in a total evidence analysis, which includes morphological and the most recent molecular data. This analysis highlights several problems with the idea of a simple “Hox cluster type” synapomorphy between the diploblastic and triploblastic animals and suggests that the “zootype differentiation” of the Hox cluster most likely is an invention of the triploblasts. The view presented is compatible with the idea that early Hox gene evolution started with a single proto‐Hox (possibly a paraHox) gene. J. Exp. Zool. (Mol. Dev. Evol.) 291:169–174, 2001. © 2001 Wiley‐Liss, Inc.