bluuebunny/crossref_metadata_2025_split huggingface dataset:
Absence of high levels of DNA polymerase α activity in the nuclear matrix prepared from mouse erythroleukemia cells
Authors: Martelli Alberto M. , Neri Luca M. , Billi Anna Maria , Bareggi Renato , Cocco Lucio 
Published: October 2002

AbstractWe have examined the association of DNA polymerase α activity with the nuclear matrix prepared by different techniques from mouse erythroleukemia cells. At variance with the data obtained using other cell types we have found that only a small amount (less than 2%) of nuclear DNA polymerase α activity resisted extraction with high‐ionic strength buffers, even if nuclei were heat‐stabilized by incubation at 37°C for 45 min prior to subfractionation. The recovery of DNA polymerase α activity bound to the matrix was unaffected by the type of extracting agent used (NaCl or (NH4)2 SO4), by the extraction sequence or by the method employed for obtaining nuclei. These results could indicate that in some types of cells the nuclear matrix is not involved in DNA replication.
A comparison of bovine serum albumin and chicken ovalbumin as supplements for the serum‐free growth of chinook salmon embryo cells, CHSE‐214.
Authors: Barlian A. , Ganassin R. C. , Tom D. , Bols N. C. 
Published: October 2002

AbstractChicken ovalbumin and bovine serum albumin (BSA) were compared as supplements to the basal medium, L‐15, for the serum‐free cultivation of the Chinook Salmon Embryo cell line, CHSE‐214. Unlike L‐15 alone, ovalbumin and some commercial BSA preparations allowed cell proliferation and development of confluent monolayer cultures. However, only a fatty acid‐free BSA (2%) supported continuous proliferation for two years through approximately 15 subcultivations. For this, subcultivation was achieved with non enzymatic cell dissociation solutions. Also, new serum‐free subcultivation techniques were developed that utilized avian egg white trypsin inhibitors to terminate the action of either bovine or cod trypsin. Finally, CHSE‐214 were successfully cryopreserved in 2% BSA, allowing all cell cultivation steps to be performed in the absence of FBS.
Electron microprobe analysis in periodontal guided tissue regeneration.
Authors: Campos A. , González‐Jaranay M. , Moreu G. , Sánchez‐Quevedo M. C. 
Published: October 2002

AbstractElectron microprobe analysis was used to determine the evolution of Ca, P and S in regenerated tissue surrounding incisors roots after periodontal treatment with guided tissue regeneration. Our results, which showed increased Ca and P, and decreased S are discussed in relation to the process of mineralization electron probe microanalysis with potentially provided an accurate means of assessing the degree of mineralization in extremely small tissue samples.
Estrogen‐regulated expression of a growth arrest specific gene (gas‐1) in rat uterus
Authors: Ferrero Marina , Cairo Gaetano 
Published: October 2002

Abstractgas‐1 belongs to a family of growth arrest specific genes negatively regulated after growth induction of arrested cells. We report the expression of gas‐1 in an in vivo system of cell proliferation. gas‐1 mRNA accumulates progressively in the uterus of ovariectomized rats with a peak at three weeks after surgery. After estrogen treatment gas‐1 mRNA levels decrease within two hours, at a time when c‐myc expression is greatly increased, and return to pretreatment levels at 48 hours. Treatment with cycloheximide does not prevent estrogen‐induced down‐regulation of gas‐1 mRNA levels. The present results show that: i) estrogen affects the uterine growth state by regulating the expression of both positively and negatively acting genes, ii) gas‐1 expression is controlled by cellular growth state also in vivo.
Correction of the defective extracellular matrix of Ehlers‐Danlos syndrome skin fibroblasts by dexamethasone.
Authors: Moro Laura , Colombi Marina , Zoppi Nicoletta , Ghinelli Annalisa , Barlati Sergio 
Published: October 2002

AbstractSkin fibroblasts derived from Ehlers‐Danlos syndrome (EDS) patients lack an organized extracellular matrix (ECM) of fibronectin (FN) and often show an accumulation of cytoplasmic FN. The treatment of EDS cells of different types (I to VIII) with 10‐7 M dexamethasone (dex), as well as cocultivation with control fibroblasts, induced in most cases the assembly of a FN‐like ECM. The study of FN mRNA expression by dot‐blot hybridization and of FN released into the culture media of EDS cells showed that the correction of the defective FN‐ECM of EDS cells by dex treatment is associated in most cases with an increase of FN mRNA synthesis and of secreted FN.
4‐Hydroxynonenal induces membrane perturbations and inhibition of basal prostacyclin production in endothelial cells, and migration of monocytes.
Authors: Moldovan Nicanor I. , Lupu Florea , Moldovan Leni , Simionescu Nicolae 
Published: October 2002

ABSTRACTCultured bovine aortic endothelial cells (BAEC) were incubated for 5 days with 10−5 4‐hydroxynonenal (HN). HN treated BAEC and controls were either (i) further incubated with 125I‐polymyxin B (IPxB) or with radioiodinated, inactivated coagulation factor Xa (IFXai) as markers of membrane phospholipid perturbation, or (ii) assayed for the synthesis of prostacyclin (PGI2) and thromboxane A2 (TXA2). Rabbit blood mononuclear cells enriched in monocytes (MC) were isolated and assayed for chemotactic response to HN. The results showed six ‐ fold increases of IPxB and IFXai binding to BAEC treated with HN, as compared to untreated controls. We also found in HN treated cells a marked inhibition of PGI2 synthesis, but an unmodified TXA2 production. In addition, HN in the 10‐5‐10‐10 M range induced oriented migration of MC.
Studies on 17‐1A antigen gene regulation in nonexpressing A549 and A431 cells, as compared to expressing pancreatic carcinoma (CAPAN 2) cells, reveal a complex mechanism of repression of this gene.
Authors: Siemieniako Barbara , Wiland Ewa , Trzeciak Wiesław H. 
Published: October 2002

ABSTRACTElements controlling high expression of the 17‐1A antigen gene in pancreatic carcinoma cells (Capan 2) reside within the two regions: proximal (−193 to +3) and distal (−877 to −518). We demonstrate here that some factors present in nuclear extracts from nonexpressing cells bind specifically to the control elements, important for gene expression. Our results suggest that nonexpressing cells may either lack at least one of the factors necessary for activation or may contain their modified forms. A major difference between expressing and nonexpressing cells was found in the region containing core enhancer sequence. Moreover, nonexpressing cells display a complex pattern of DNA‐protein interactions in this region, suggesting that these cells contain factors acting negatively mainly on the enhancer sequence. Our results however, indicate that the mechanism of repression is much more complicated than expected.
Transforming growth factor β1 increases the phosphoenolpyruvate carboxykinase mRNA level in cultured rat hepatocytes
Authors: Thoresen G. Hege , Christoffersen Thoralf 
Published: October 2002

ABSTRACTTransforming growth factor β1 (TGFβ1) elevated the phosphoenolpyruvate carboxykinase (PEPCK) mRNA abundance in primary cultures of rat hepatocytes. Although this increase was not as large as the rise in PEPCK gene expression induced by the cAMP‐elevating agents glucagon or isoproterenol, the effect of TGFβ1 was several‐fold and concentration‐dependent, with ED50 at about 2.5 pM, which is in the same concentration range as the previously found growth‐inhibitory effect of TGFβ. The data show that the level of mRNA for PEPCK, an enzyme typically expressed in the liver, can be regulated in the same direction by TGFβ1 and cAMP.
Some aspects of zinc transport across eel (Anguilla anguilla) red blood cell membranes.
Authors: Mandolfino M. , Cimino G. , Scuteri A. , Cordì R. , Romano L. 
Published: October 2002

ABSTRACTZinc movement across eel and human red blood cell membranes was measured by atomic absorption spectrophotometry. It was observed that:
In human red blood cells zinc uptake is twice as rapid as in fish red blood cells over a temperature range of 10‐40°C. The low rate of zinc uptake in eel red blood cell may be simply the side effect of different surface area to volume ratios for the differences in cell size or, it may be due to the low permeability of bicarbonate through the red blood cell membranes.
Zinc uptake measured in eel and human red blood cells treated and untreated with external trypsin shows different features. The zinc uptake was reduced by about 40% in treated eel red blood cells with respect to the total uptake of untreated red blood cells. Human red blood cells treated and untreated with trypsin do not show any differences in the amount of zinc transported.
In fish red blood cells, zinc uptake in NANO3 medium is markedly reduced, compared with that measured in NaCl medium. The [Zn2+i slightly increases in the presence of bicarbonate. In human red blood cells in NANO3 medium the zinc uptake is strongly reduced and the presence of bicarbonate marginally increases the zinc influx.
In eel red blood cells there seem to be two independent pathways for zinc uptake: one DIDS‐sensitive and the other DIDS‐insensitive. DIDS 10 μM inhibits only 64% of the total zinc transported. Iincreasing the DIDS concentration did not give more inhibition. In human red blood cells only one DIDS‐sensitive pathway for zinc transported seems to exist, because, 2,5 μM DIDS inhibits 97% of zinc uptake.
Functions of the v‐SRC protein tyrosine kinase
Authors: Fincham V. , Frame M. , Haefner B. , Unlu M. , Wyke A. , Wyke J. 
Published: October 2002

ABSTRACTThe peripheral non‐receptor tyrosine kinase oncoprotein, v‐Src, has pleiotropic effects. It is a mitogen for quiescent cells, substituting for both competence and progression factor‐mediated signals but it also induces cellular morphological transformation. We are dissecting the activities of v‐Src by studying mutant proteins, including those with temperature sensitive (ts) effects, in different cellular backgrounds. Activation of a ts v‐Src kinase rapidly increases activity of both the transcription factor, AP‐1, and MAP kinase, an enzyme that enhances AP‐1 activity by both phosphorylation of c‐Jun and increased c‐fos transcription; the relative contribution of these two events depends on the cells in which v‐Src is expressed. Transient early AP‐1 activation requires proper location of v‐Src at the cell periphery and it is essential for mitogenesis. It is not, however, sufficient for entry into S‐phase, there being a second need for v‐Src later in G1. Transformation by v‐Src does not require AP‐1 activation but seems linked to events at the cell periphery, notably phosphorylation of proteins that bind to the v‐Src SH3 domain such as the p85 subunit of PI‐3 kinase.
IL‐1 alpha antiproliferative and differentiative effects on Daudi lymphoma cells: multiparametric analysis.
Authors: Santavenere E. , DI Pietro R. , Centurione M. A. , Trubiani O. , Zamai L. , Rana R. 
Published: October 2002

ABSTRACTInterleukin Iα (IL‐1) is a potent agent that induces a wide range of biological effects. In this study we analysed its effects on cell cycle progression and differentiation of Daudi Iymphoma cells. The parallel analysis in light microscopy and cytofluorimetry by means of anti‐BrdU monoclonal antibodies showed a reduced rate of proliferation (S phase) with a G1 arrest. These features were confirmed by the lower incorporation of [3H]‐thymidine supporting the decrease in the rate of DNA synthesis. In addition this cytokine was able to induce differentiation after 24 hrs of treatment as assessed by the increased expression of Fc receptors (FcR) and morphological criteria. This multiparametric analysis gives evidence to the sensitivity to this cytokine of this peculiar cell line.
Models for solid‐state transport: messenger RNA movement from nucleus to cytoplasm.
Authors: Agutter Paul S. 
Published: October 2002

ABSTRACTThis paper explores the idea that mRNAs are transported between their transcription and processing sites in the nucleus, and their translation and degradation sites in the cytoplasm, by a ‘solid‐state’ process. The underlying assumption is that negligible quantities of mRNA and of mRNA precursors are in solution in vivo. Therefore, mRNA transport cannot be considered as movement in the aqueous phase of the cell. The main lines of experimental evidence supporting this ‘solid‐state’ concept are summarized and related controversies are outlined. Three possible models for a solid‐state transport mechanism are discussed: a direct transfer model, with receptors organized analogously to the components of a multienzyme complex; a motor‐driven model, analogous to synaptic vesicle transport in axons; and an assembly‐driven model which assumes net movement along a fibril resulting from differential activities at the poles. Qualitative evaluation indicates that each of these models has characteristic advantages and disadvantages. The possibility that other nucleocytoplasmic transport processes might operate by solid‐state mechanisms is briefly discussed.
PCNA Ki‐67 dissociation in childhood acute lymphoblastic leukaemia. An Immunofluorescent Laser Confocal Scanning Microscopical study.
Authors: Ball Lynne M. , Pope Jason , Howard Charles V. , Eccles Paul , van Velzen Dick 
Published: October 2002

ABSTRACTCell proliferation rates of diagnostic marrow aspirate cells of 21 children with Acute Lymphoblastic Leukaemia and 16 controls were compared using immunocytochemical labelling of PCNA and Ki‐67 antigen as assessed by Confocal Laser Scanning Microscopy.The results showed an unexpected, highly significant degree of dissociation between PCNA and Ki‐67 expression in ALL blasts. The PCNA labelling indices of ALL patients were significantly increased (mean 44, range 24‐77) compared with normal reactive marrow cells (mean 13.8, range 4‐26) (p<0.000001, Mann Whitney U two tailed test), suggesting an abnormal commitment to proliferation. Ki‐67 expression was raised to a lesser extent in ALL cells (mean 14.8, range 1.2‐35) when compared to non‐malignant proliferations (mean 6.6, range 1.7‐25) (p < 0.02). PCNA/Ki‐67 LI ratios in ALL (mean 7, range 1.1‐35) were higher than in controls (mean 2.7, range 1.04‐6.5, p<0.09).As cell proliferation rates actually achieved in the bone marrow do not differ as strongly as suggested by the extreme difference in PCNA labelling, a pathological dissociation of PCNA / Ki‐67 expression exists, suggesting immortalisation.
Urceolaria mitra (von Seib) Epizoic on Polycelis tenuis (IJIMA) an SEM Study.
Authors: Bowen I. D. , Ryder T. A. 
Published: October 2002

ABSTRACTDense populations of Urceolaria mitra (Cilophora, Peritrichid) were observed on the surface of the planarian Polycelis tenuis (Platyhelminthes Turbellaria). Although the epizoite was primarily confined to the anterior dorsal surface of the planarian, heavily infested individuals had peritrichs attached to the posterior, lateral and ciliated ventral surfaces. Unique profiles of the skeletal ring (aboral disc) in relation to the host surface showed that some local erosion of planarian epithelium occurs. Outer and inner rows of cilia extended anti‐clockwise around the peristomal disc. The cilia ran for one and one‐eighth turns around the disc and overlapped in the form of a spiral when the protist was extended and feeding. The cilia appeared to beat in metachronal rhythm and exhibited a wavelength and amplitude of approximately 10μm. Regular striations having a periodicity of 1μm were observed in the periostimal membrane. A posterior or basal circlet of locomotor cilia was also observed and freeze fracture revealed an internal arrangement of microvilli, cilia and reticular membranes.
INTEGRIN EXPRESSION AND COLLAGEN TYPE II IMPLICATED IN MAINTENANCE OF CHONDROCYTE SHAPE IN MONOLAYER CULTURE: AN IMMUNOMORPHOLOGICAL STUDY
Authors: SHAKIBAEI M. , De SOUZA P. , MERKER H.‐J. 
Published: October 2002

AbstractChondrocytes grown in monolayer culture at low density, with serum added, either dedifferentiate after several days whereby their cell shape changes or they are overgrown by fibroblast‐like cells. The aim of this study was to optimize the cultivation of chondrocytes in monolayer culture and to slow down their transformation or their overgrowth by fibroblast‐like cells. For this purpose freshly isolated chondrocytes of cartilage anlagen from 17‐day‐old mouse embryos were grown on plastic or collagen type II‐coated substrates. With this model: (a) chondrocytes grown on plastic substrates had almost completely changed to fibroblast‐like cells after 5 days in culture. (b) When grown on collagen type II, the chondrocytes maintained their round phenotype for more than 2 weeks in culture. (c) Immunomorphological investigations showed that chondrocytes produce collagen type II and fibronectin and express specific surface receptors (integrins of the β1‐group) on the membrane from day 1 until the end of the culture period when grown on collagen type II. (d) Treatment with β1‐integrin antibodies clearly reduces chondrocyte adhesion on collagen type II by about 70%. Hence, these data indicate that the most probable influence of collagen type II on cellular behaviour depends on the integrins participating in a chondrocyte—collagen type II interaction, and this model represents a pure chondrocyte culture which allows cell growth for an extended period.
OPOSSUM KIDNEY CELLS TAKE UP L‐DOPA THROUGH AN ORGANIC CATION POTENTIAL‐DEPENDENT AND PROTON‐INDEPENDENT TRANSPORTER
Authors: GOMES P. , SERRÃO M.P , VIEIRA‐COELHO M.A , SOARES‐DA‐SILVA P. 
Published: October 2002

AbstractThe present work was aimed at studying the kinetics and nature of the l‐DOPA transporter in opossum kidney (OK) cells. Saturation experiments were performed in OK cells incubated for 6 min with increasing concentrations of l‐DOPA (10 to 2500 μm); non‐linear analysis of the saturation curve revealed for l‐DOPA aKmof 129 μm (114, 145) and aVmaxof 30.0±0.4 nmol mg protein−16 min−1The uptake of l‐DOPA (250 μm) was inhibited in a concentration‐dependent manner by cyanine 863, an organic cation inhibitor, with aKivalue of 638 (430, 947) μmthe organic anion inhibitor 4,4′‐diisothiocyanostilbene‐2,2′‐disulphonic acid (DIDS), was devoid of effect upon the uptake of l‐DOPA. The uptake of l‐DOPA (250 μm) was significantly (P<0.02) decreased (25% reduction) when cells were incubated in the presence of 137 mm K+plus 5 mm Na+when compared with the control condition (137 mm Na+plus 5 mm K+); substitution of NaCl by choline chloride (137 mm) did not affect l‐DOPA uptake. Similarly, inwardly or outwardly directed proton gradients of 0.5 pH units (7.9, 7.4, 6.9, 6.4 and 5.9) were found not to change l‐DOPA uptake. In conclusion, the l‐DOPA uptake system in OK cells has the characteristics of an organic cation potential‐dependent and proton‐independent transporter.
DISCORDANCE BETWEEN THE EFFECT OF MODULATORS OF CALCIUM ON STAUROSPORINE‐INDUCED APOPTOSIS AND STAUROSPORINE‐INDUCED ACTIN DEGRADATION
Authors: Rabkin Simon W. , Kong Jennifer Y. 
Published: October 2002

AbstractStaurosporine produced DNA fragmentation characteristic of apoptosis and a dramatic alteration of cell structure that include alterations of cytoskeletal actin and cytoplasmic condensation with vacuolization. These changes were not induced by chelerythrine, a more specific PKC inhibitor than staurosporine. The calcium chelator, BAPTA, significantly reduced staurosporine‐induced DNA fragmentation but did not affect staurosporine‐induced changes in cytoskeletal actin. These data suggest that DNA fragmentation and actin degradation in apoptosis, induced by staurosporine, are under different regulatory control by calcium.
SOLUBILITY PARTITIONING OF C/EBPβ ON THE RAT HEPATOCYTE NUCLEAR MATRIX BY HYDROPHOBIC INTERACTIONS
Authors: Uskoković Aleksandra , Vidaković Melita , Dinić Svetlana , Ivanović‐Maticć Svetlana , Martinović Vesna , Poznanović Goran 
Published: October 2002

AbstractThe greatest part of nuclear C/EBPβ (a major 35kD protein, 30 and 38kD isoforms) was observed to partition with the nuclear matrix. Cross‐linking experiments with formaldehyde suggested that the association reflected the in situ juxtapositioning of C/EBPβ to nuclear matrix proteins in isolated nuclei. The association of C/EBPβ with the nuclear matrix resisted RNase and DNase treatment and extraction with protein sulfhydryl reducing agents combined with high ionic strength salt. C/EBPβ displayed a proclivity to extensively reassemble with the filament‐forming nuclear matrix proteins after a cycle of solubilization with urea, followed by its removal by dialysis. These findings suggest that the C/EBPβ moieties were anchored to the nuclear matrix through hydrophobic protein‐protein interactions with the lamins. Subsequent separation of nuclear matrix‐associated C/EBPβ into insoluble, reassembling, and soluble nuclear matrix protein (SNMP) fractions after a cycle of solubilization/reassembly pointed to the sub‐partitioning of C/EBPβ on the nuclear matrix. DNA affinity chromatography using the rat haptoglobin gene cis ‐element and SNMP revealed the binding of p35 during basal transcription, and p35 and p30 during elevated haptoglobin gene transcription in the course of the acute‐phase (AP) response. It was concluded that the appearance of cis ‐element‐binding p30 in the SNMP fraction resulted from its increased solubility (decreased hydrophobicity) and inability to reassociate with the lamins during urea removal. The observed solubility partitioning of C/EBPβ on the nuclear matrix framework could represent a level of control of the general availability of regulatory proteins for establishing interactions with DNA.
A Pre-Illinoian Pleistocene Fossil Assemblage from Near Connersville, Southeastern Indiana
Authors: Miller Barry B. , Palmer Donald F. , McCoy William D. , Smith Alison J. , Colburn Mona L. 
Published: October 2002

AbstractA fossil assemblage containing molluscs, ostracodes, and fish has been recovered from lacustrine sediments from near Connersville, southeastern Indiana. The reversed remanent magnetic signature of the sediments and the extent of isoleucine epimerization in molluscan shell protein indicate a pre-Illinoian age for the fossils. The fauna includes four taxa of fish,Coregonussp., cf.Prosopiumsp., cf.Thymallus arcticus,andCatostomussp.; four taxa of ostracodes,Cytherissa lacustris, Candona caudata, Cyclocypris ampla,andCandonasp.; and 28 taxa of molluscs. Elements of the aquatic molluscs, fish, and ostracodes suggest a cool-water lake (8° to 16°C). The terrestrial molluscs include boreal species that now reach the southern limits of their range in the Great Lakes region near the north shore of Lake Superior and imply average summer temperatures of about 15°C near the lake margins. The lake may have been formed when West Lebanon ice advanced into the Anderson-New Castle Buried Valley system which drained northwest as a tributary of the Lafayette Bedrock Valley System.
The Faunal Remains from Evron Quarry in Relation to Other Lower Paleolithic Hominid Sites in the Southern Levant
Authors: Tchernov Eitan , Horwitz Liora Kolska , Ronen Avraham , Lister Adrian 
Published: October 2002

AbstractThe mammalian assemblage and archaeological finds from the Lower Palaeolithic hominid site of Evron Quarry, situated on the northern coastal plain of Israel, are described and discussed. In their lithic and faunal composition, the sites of Latamne (QfIII) (Latamne Formation, Orontes, Syria) and Sitt Markho (Nahr elKebir, Syria) resemble Evron and are probably contemporaneous. It is suggested here, based on their lithic and faunal composition, that these sites may be chronologically closer to the site of Ubeidiya ('Ubeidiya Formation, Jordan Valley, Israel; 1.4 myr) than to the sites of Gesher Benot Ya'akov (dated as <800,000 yr B.P.), which differs in both aspects from Evron. The mammalian faunule from Evron comprises a biogeographical mixture, a result of biotic exchanges with Africa, the Oriental region, and the Palaearctic. This exchange may have been associated with a post-'Ubeidiya hominid dispersal, either from Africa or south Asia via the Levantine "corridor."