bluuebunny/crossref_metadata_2025_split huggingface dataset:
Changes in the concentration of ions during senescence of the human erythrocyte.
Authors: Cameron Ivan L. , Hardman W. Elaine , Smith Nancy K. R. , Fullerton Gary D. , Miseta Attila 
Published: October 2002

AbstractFlash frozen samples of normal human blood were cryosectioned and cryodried for electron probe x‐ray microanalysis of the concentration of ions and elements in individual erythrocytes (RBCs). The data (expressed in mM/kg dry weight) demonstrated a systematic pattern of variation between the concentration of ions and elements in the RBCs. Specifically as K+ and Cl decreased in concentration, Ca2+ and sulfur increased in concentration. Phosphorous, Na+ and Mg2+ did not demonstrate a significant pattern of change. These findings are related to the dehydration and to the volume decrease that accompanies senescence of the RBC.
Differential expression of adult type MHC in satellite cell cultures from regenerating fast and slow rat muscles.
Authors: Cantini Marcello , Fiorini Emma , Catani Claudia , Carraro Ugo 
Published: October 2002

AbstractThe local anaesthetic (Bupivacaine (1‐n‐butyl‐DL‐piperidine‐2‐carboxylic acid‐2, 6‐dimethyl anilide hydrochloride) has been used to induce myofiber damage (and thus satellite cells proliferation) and thereby represents a tool for increasing the yield of myoblasts from adult muscles. Replicating satellite cells were isolated by enzymatic dissociation from soleus (slow type) and tibialis anterior (fast type) muscles of adult rats, and categorized by the isoform (embryonic, fast and slow) of myosin heavy chain (MHC) expressed following myotube formation in a similar in vitro environment. According to light microscopic criteria, no morphological differences exist between the satellite cell cultures obtained from adult fast and slow muscles after Bupivacaine injection. On the other hand the derived myotubes express, beside the embryonic type, the peculiar myosin heavy chains which characterize the myosin pattern of the donor muscles.
Effect of enthidium on the morphology, antiviral activity and subcellular distribution of Poly r(A‐U)
Authors: Jamison James M. , Gilloteaux Jacques , Adrian Marc , Summers Jack L. 
Published: October 2002

AbstractWhen ethidium bromide (EB) is combined with poly r(A‐U) at an EB/ribonucleotide ratio of 1/4, the antiviral activity of the EB increases 22‐fold. The increased antiviral activity is not due to increased interferon induction, direct viral inactivation or host cell cytotoxicity. Phase contrast, confocal and fluorescence microscopic observations reveal an increase in the nucleolar accumulation of the EB and/or the poly r(A‐U) in the EB/poly r(A‐U)‐treated fibroblasts. Ultrastructure of negatively stained and replica preparations demonstrated that EB‐induced condensation of poly r(A‐U). These results suggest the elevated antiviral activity may be related to the altered uptake and subcellular distribution of the EB/poly r(A‐U) complex.
The prominent 28 kDa polypeptide in clathrin coated vesicle fractions from developing pea cotyledons is contaminating ferritin
Authors: Hoh Birgit , Robinson David G. 
Published: October 2002

AbstractSDS‐PAGE of clathrin coated vesicle (CCV) fractions prepared from developing pea cotyledons are characterized by the presence of a 28 kDa polypeptide. Like clathrin light chains, this polypeptide is heat‐stable and can bind calcium ions. However, the distribution of this polypeptide is not identical to that of clathrin in the rate zonal gradients used to purify CCV. Negatively stained preparations reveal small, 12 nm diameter hollow particles, in addition to CCV. As judged by the electron dense centre to these particles, we infer that CCV preparations from pea cotyledons are contaminated with phytoferritin. This has been confirmed by immuno‐blotting with pea ferritin antibodies. The degree of phytoferritin contamination in CCV fractions is greater when RNase digestion of postmicrosomal pellets is performed at cold, rather than warm temperatures.
Transfected Chinese hamster ovary cells as a model system for cytokine immunocytochemistry and in situ hybridisation.
Authors: Mueller Regula , Junker Udo , Wagner Kathrin , Heusser Christoph , Bullock Gillian 
Published: October 2002

AbstractThe presence of cytokine producing cells is most easily revealed by techniques measuring the secreted cytokines in culture supernatants or body fluids. However, these techniques only measure the bulk cytokine release by a given, often mixed cell population. To demonstrate cytokine production at the single cell level, immunocytochemistry (ICC) and in situ hybridisation (ISH) are now widely used techniques. To establish these techniques, an easily accessible model system is needed which permits the evaluation of different ICC and ISH protocols. It can be used to demonstrate the specificity of the antibodies and may serve as a positive control for samples of unknown cytokine content. Here we propose the use of Chinese hamster ovary (CHO) cells transfected to express one specific cytokine as such a model system. Its usefulness is demonstrated by the characterisation of six monoclonal antibodies to human interleukin‐4 and the establishment of two in situ hybridisation protocols.
VLA‐2 mediates the interaction of collagen with endothelium during in vitro vascular tube formation.
Authors: Jackson Christopher J. , Knop Alison , Giles Irina , Jenkins Kate , Schrieber Les 
Published: October 2002

ABSTRACTA confluent endothelial monolayer can be induced to form vascular tubes in response to collagen. We investigated possible mechanisms of collagen‐induced tube formation by using antibodies to the VLA‐2 integrin receptor and protein kinase C inhibitors. Pre‐incubation of cells with anti‐VLA‐2 (which recognises both the α2 and β1 chains) and AK7 (which recognises only the α2 chain) showed a dose‐dependent inhibition of tube formation. At 50 μg/ml, anti‐VLA‐2 completely inhibited collagen‐induced tube formation, whereas AK7 caused only partial inhibition. Both chlorpromazine and trifluoperazine, at concentrations of 10μM, prevented tube formation (> 40% inhibition), In summary, the VLA‐2 integrin receptor plays a role in the induction of tube formation by type I collagen. Protein kinase C may be activated during this process.
The induction of protrusion by neomycin in human glioma cells is correlated with a decrease followed by an increase in filamentous actin.
Authors: Safiejko‐Mroczka Barbara , Bell Paul B. 
Published: October 2002

AbstractIn this paper we describe an experimental investigation of the mechanism of motility of vertebrate cells. Human glioma cells were treated with neomycin, an inhibitor of the phosphatidylinositol cycle; and changes in cell motility and the cytoskeleton were examined by video, fluorescence, and scanning electron microscopy and by cytofluorometry. Neomycin stimulates a single protrusion of lamellipodia from the cell margin, which is correlated with an initial rapid decrease in the amount of F‐actin throughout the cell, especially at the cell edge; the fragmentation of actin filaments within the lamellipodia; and the subsequent de novo polymerization of F‐actin in a marginal band at the leading edge of lamellipodia. Changes in F‐actin are paralleled by changes in the distribution and amount of gelsolin. These results support the hypothesis that protrusion is initiated by the gelsolin‐mediated severing and subsequent depolymerization of cortical actin filaments, which weakens the cell cortex, allowing hydrostatic or gel osmotic pressure to force the cell margin to protrude. The accompanying polymerization of filaments actin at the leading edge of the protrusion may stabilize the protrusion and support its expansion.
THE ROLE OF CDC2, CDC25 AND CYCLIN A GENES IN THE MAINTENANCE OF IMMORTALIZATION AND GROWTH ARREST IN A RAT EMBRYONIC FIBROBLAST CONDITIONAL CELL LINE
Authors: GONOS EFSTATHIOS S. , SPANDIDOS DEMETRIOS A. 
Published: October 2002

AbstractImmortalization of rodent cells by oncogenes is a complex biological process which involves the abnormal regulation of genes who control cellular proliferation. The role of the cell cycle control genes cdc2, cdc25 and cyclin A in the maintenance of immortalization and in growth arrest was examined in the tsa14, a SV40 T antigen rat embryonic fibroblast conditional for growth cell line. Analysis of RNA expression showed minimal levels of cdc2 mRNA in both proliferating and growth‐arrested tsa14 cells. In contrast, cyclin A mRNA was found downregulated in growth‐arrested tsa14 cells, as well as in senescent primary rat embryonic fibroblasts (REFS). The ability of cdc2, or cdc25, or cyclin A genes to maintain the tsa14 immortal phenotype was also examined by electroporations of these genes into the tsa14 cells. Clones over‐expressing the electroporated cdc2, or cdc25, or cyclin A, or combinations of these genes growth arrested at the non‐permissive conditions similar to controls, thereby suggesting that the expression of these genes alone is insufficient for tsa14 maintenance of immortalization.
DIGITAL IMAGE ANALYSIS OF CHROMATIN FIBRE PHENOTYPE AFTER ‘IN SITU’ DIGESTION WITH RESTRICTION ENDONUCLEASES
Authors: GOSÁLVEZ JAIME , LÓPEZ‐FERNÁNDEZ CARMEN , FERNÁNDEZ JOSÉ L. , GOYANES VICENTE J. , BUÑO ISMAEL 
Published: October 2002

AbstractRestriction Endonucleases (REs) may recognize, cleave and remove DNA from fixed chromatin producing specific chromosome banding patterns. However, the modifications produced in the chromatin fibre are not easy to evaluate and compare. The aim of the present investigation was to visualize differences resulting in the texture of the chromatin fibre from metaphase chromosomes after each digestion using digital image analysis (DIA) facilities. To this purpose, metaphase chromosomes derived from a L‐929 mouse cell line were digested with different REs (AluI,HpaII andHaeIII).Since light microscopy does not permit the observation of the chromatin fibre, DIA was performed on digitalized images of metaphase chromosomes under electron microscopy. The application of a LUT (Look Up Table) within the DIA software assigns a colour to each grey level of a digital image. The results obtained using a particular LUT, which permits the discrimination of specific chromatin fibre phenotypes resulting from each digestion, are reported and compared with those obtained under the light microscope.
STUDIES ON NITRIC OXIDE FREE RADICALS GENERATED FROM POLYMORPHONUCLEAR LEUKOCYTES (PMN) STIMULATED BY PHORBOL MYRISTATE ACETATE (PMA)
Authors: ZHAO BAO‐LU , WANG JIAN‐CHAO , HOU JING‐WU , XIN WEN‐JUAN 
Published: October 2002

AbstractThe interaction of NO and O−2free radicals generated from PMA (phorbol myristate acetate)‐stimulated PMN (polymorphonuclear leukocytes) was studied by a nitroxide spin trap, DMPO (5,5‐dimethyl‐1‐pyrroline‐1‐oxide). It was found that addition of L‐arginine to the system would significantly decrease the trapped O−2by DMPO and addition of NG‐monomethyl‐arginine (NGMA) would significantly increase the trapped O−2by DMPO. It was proved that the formation of ONOO−by the reaction of NO and O−2was the main reason for the decrease of trapped O−2in the experiment with xanthine/xanthine oxidase and irradiation of riboflavin systems. The yield of NO during this process was calculated. The generation dynamic of NO was studied by a luminol‐dependent chemiluminescence technique and it was found that after stimulation of PMN by PMA, there would be an immediate, significant chemi‐luminescence, which came mainly from the active oxygen free radicals generated by PMN. If L‐arginine was added to this system, the chemiluminescence would increase about 100‐fold, but NGMA inhibited the increase of the chemiluminescence. Ten minutes after addition of L‐arginine, this increase did not change, the chemiluminescence peak decreased gradually, but the half life increased. The ESR and chemiluminescence properties of NO and ONOO−synthesized were also studied in model systems.
ENHANCEMENT OF 5‐FLUOROURACIL CYTOTOXICITY BY CISPLATIN IN BRAIN TUMOUR CELL LINES
Authors: MINEURA KATSUYOSHI , KOWADA MASAYOSHI 
Published: October 2002

AbstractCisplatin reportedly plays an important role as a chemical modulator in enhancing the chemotherapeutic effects of 5‐fluorouracil on tumour cells. The aim of the present study was to test the synergistic cytotoxicity of cisplatin and 5‐fluorouracil in 5‐fluorouracil‐resistant (C6) and ‐sensitive (9L) rat brain tumour cell lines. Survival fractions, determined using colony‐formation assays, were compared following 5‐fluorouracil treatment, with and without cisplatin. The presence of cisplatin (1–10μm) enhanced cytotoxicity by more than three times compared with 5‐fluorouracil alone in 5‐fluorouracil‐resistant C6 cells, whereas no enhancement effects were noted in 9L cells. These results suggest that a cisplatin‐fluorouracil‐based regimen may be promising in the treatment of 5‐fluorouracil‐resistant brain tumours.
CHARACTERIZATION OF FORCED SUSPENSION CULTURE OF SPONTANEOUSLY TRANSFORMED MOUSE FIBROBLASTS (B‐6)
Authors: MATSUHISA TADAO , TAKEMURA KOUICHI 
Published: October 2002

AbstractMouse fibroblasts (B‐6) were cultured on agar‐coated dishes. After cells grew for 2–3 generations relatively rapidly in suspension, they began to grow very slowly (stationary phase). Electron microscopic studies showed that cells in a stationary phase developed intracellular organella: membranous structures (endoplasmic reticulum and Golgi apparatus) became manifest and the number of mitochondria increased. The specific activities of succinic‐cytochrome c reductase and 5′‐nucleotidase were three and five times higher, respectively, than those of cells on the dish.
CELL SURFACE ALTERATIONS BY TAXOL ASSOCIATED WITH ABNORMAL MORPHOGENESIS IN THE CHICK EMBRYO
Authors: PATWARDHAN VIDYA , GHATE H. V. , GHASKADBI SURENDRA 
Published: October 2002

AbstractThe anticancer drug taxol brings about its biological effects by altering the stability of microtubules. We have examined the effects of taxol on early morphogenesis in chick embryos culturedin vitro. Taxol induced various abnormalities in the developing nervous system, heart and somites as well as general retardation of development. SEM studies revealed that taxol treatment leads to dramatic alterations in the embryonic cell surfaces. Time‐course experiments demonstrated that the action of taxol is very rapid and becomes evident within a few minutes at the ultrastructural level. Taxol thus throws embryonic cell adhesion and motility out of balance. This appears to be the major cause of abnormal morphogenesis in taxol‐treated embryos.
ISOLATION OF CYTOCHROME OXIDASE COMPLEX FROM SEA URCHIN MITOCHONDRIAL INNER MEMBRANES
Authors: KUTRA TEOFANI , TIMONERI MARINA , OLIVA ANTONINO , RINALDI ANNA MARIA 
Published: October 2002

AbstractCytochrome oxidase complex has been isolated and purified from sea urchin mitochondrial inner membranes. The complex exhibited a discrete number of bands in PAGE and a 17 kDa band was recognized by an anti‐human subunit IV antibody. No bands were recognized by an anti‐yeast hsp60 antibody and an anti‐sea urchin β ATPase subunit.
THE DISTINCT STEPS OF CELL DETACHMENT DURING DEVELOPMENT OF MOUSE UROEPITHELIAL CELLS IN THE BLADDER
Authors: JEZERNIK K. , STERLE M. , BATISTA U. 
Published: October 2002

In developing mouse urinary bladder the urothelial cells respond to urine accumulation by cell detachment, i.e. desquamation. To elucidate the steps of urothelial cell detachment during embryonic development and first urine accumulation in bladder lumen, superficial and intermediate cell layers were investigated. Different electron microscopic and cytochemical methods have been used. It was possible to distinguish between an early and late events on the basis of morphology. At the beginning cell detachment involves interruption of tight junctions between neighbouring superficial cells and the formation of numerous endocytotic vesicles. Endocytotic and cup‐shaped vesicles then fuse and form large parallel rows of vacuoles and multivesicular bodies in desquamating superficial cells and in the neighbouring superficial and intermediate cells. These observations clearly demonstrate the existence of specific steps during the detachment of embryonic uroepithelial cells.Apoptosis accompanies cell desquamation. Only predetermined superficial bridge cells die in an apoptotic manner.
INHIBITION OF PHENOTYPE MODULATION, GROWTH, AND MIGRATION OF VASCULAR SMOOTH MUSCLE CELLS BY A GUANOSINE‐RICH 30‐MER PHOSPHOROTHIOATE OLIGODEOXYNUCLEOTIDE
Authors: GRAHAM L. D. , HAYWARD I. P. , FITZGERALD M. , WHITELOCK J. M. , BINGLEY J. A. , CAMPBELL J. H. , UNDERWOOD P. A. 
Published: October 2002

AbstractThe testing of a 30‐mer dG‐rich phosphorothioate oligodeoxynucleotide (LG4PS) for effects on the behaviour of vascular smooth muscle cells (VSMC)in vitroandin vivois described. LG4PS at 0.3μminhibited significantly the phenotype modulation of freshly isolated rabbit VSMC, and cell outgrowth from pig aortic explants was inhibited ∼80% by 5μmLG4PS. The growth of proliferating rabbit and pig VSMC was inhibited ∼70% by 0.3μmand 5μmLG4PS, respectively. Though less marked, the antiproliferative effects of LG4PS on human VSMC were comparable to those obtained with heparin. The cytotoxic effects of LG4PS on VSMCin vitrowere low. Despite these promising results, adventitial application of 2–200nmol LG4PS in pluronic gel failed to reduce vascular hyperplasia in balloon‐injured rabbit carotid arteries, and the highest dose caused extensive mortality.
EFFECT OF SUBLETHAL DOSES OF CADMIUM, INORGANIC MERCURY AND METHYLMERCURY ON THE CELL MORPHOLOGY OF AN INSECT CELL LINE (AEDES ALBOPICTUS, C6/36)
Authors: BRAECKMAN BART , SIMOENS CAROLINE , RZEZNIK URSZULA , RAES HILDA 
Published: October 2002

AbstractThe effect of CdCl2(44μm), HgCl2(3.7μm), and MeHgCl (2μm) on the morphology ofAedes albopictusC6/36 cells was studied at the light microscopical level. Treatment times and metal concentrations were in the sublethal range as determined by a fluorometric dye exclusion test. The three metal species had profound effects on the cell morphology. MeHgCl treatment induced the development of a large number of short, actin‐supported, tangled filopodia. Both CdCl2and HgCl2induced long extensions. Pretreatment with colchicine but not with cyto‐chalasin B prevented formation of these extensions which suggests that they were supported by microtubules. This was confirmed by immunostaining for microtubules. The extensions were relatively stable towards colchicine post‐treatment. To authors’ knowledge, this effect has not yet been described for heavy metals. The similarity with 20‐hydroxyecdysone‐treated cells and the occurrence of cytoplasmic feet in insect cells is discussed.
RNA RELOCATION AT MITOSIS IN TRANSFORMED AND TUMORIGENIC HUMAN BREAST EPITHELIAL CELLS
Authors: Mello Maria Luiza S , Barbisan Luis F. , Russo Jose , Vidal Benedicto De C 
Published: October 2002

AbstractThe fate of RNA revealed by metachromatic staining after a critical electrolyte concentration assay using toluidine blue and Mg2+ions as competitors for the substrate dye binding sites was followed at mitosis in human breast epithelial cells transformed by benzo[a]pyrene and transfected with the c‐Ha‐ ras oncogene. The aim was to detect changes in RNA distribution during mitosis in human transformed/tumorigenic cells exhibiting increased nucleolar sizes and rRNA production while in interphase. RNA relocation in association with the mitotic spindle fibers was observed from metaphase to telophase not to vary in all the cell lines studied. RNA‐containing nucleolus‐like bodies persistent during mitosis were found to decrease in frequency in the transformed and tumorigenic cells in comparison with control non‐transformed cells simultaneously to the previously reported increase in nucleolar areas for the same cells while in interphase. It is suggested that an improved use of RNA transcripts has been developed with cell transformation and tumorigenesis in this particular model.
CISPLATIN INDUCES MODIFICATIONS IN THE DEVELOPMENT OF CELL SURFACE PATTERNS OF CILIATES
Authors: Machwe Swati , Arora Seema , Gupta Renu , Sapra G. R. 
Published: October 2002

AbstractCisplatin [cis ‐dichlorodiammineplatinum (II)] brings about significant quantitative modifications in the development of cell surface patterns in two unrelated ciliates: Stylonychia and Tetrahymena. Cells cultured in the presence of cisplatin exhibit the formation of supernumerary surface structures in the form of extra cilia/cirri (fused cilia) and other organized ciliary organelles. The metal‐induced formation of extra primordia and their differentiation into supernumerary ciliary structures is governed by the normal rules of development. Additional structures are accommodated within the framework of a defined pattern, suggesting the existence of an overall global control of pattern formation. The modified pattern is rectified to its normal state during post‐treatment fission cycles, suggesting the role of the cell membrane in correcting developmental errors.
UNUSUAL CYTOLOGICAL PATTERNS OF MICROSPOROGENESIS IN BRACHIARIA DECUMBENS: ABNORMALITIES IN SPINDLE AND DEFECTIVE CYTOKINESIS CAUSING PRECOCIOUS CELLULARIZATION
Authors: Mendes‐Bonato Andréa Beatriz , Filho Roberto Gargione Junqueira , Pagliarini Maria Suely , Do Valle Borges Cacilda , De Penteado Maria Isabel Oliveira 
Published: October 2002

AbstractCytogenetic studies carried out in the tetraploid accession BRA001068 of Brachiaria decumbens, also known as cv. Basilisk, revealed an unusual pattern of microsporogenesis. The spindle in metaphase I and anaphase I became heavily stained with propionic carmine. In telophase I, the interzonal microtubules continued to be intensely stained, and during the phragmoplast formation the fibers were pushed to the cell wall, persisting until prophase II, even after cytokinesis. Due to its tetraploid condition, the accession presented many cells with precocious chromosome migration to the poles in metaphase I and laggards in anaphase I that gave rise to micronuclei in telophase I. While in other polyploid accessions of Brachiaria micronuclei remained in this condition until the second cytokinesis, the micronuclei in this accession organized their own spindle in the second division. In several microsporocytes, the micronuclei with their minispindle were divided further into microcytes by additional cytokinesis. Some curious planes of cytokinesis were found in some cells, with partitioning of cytoplasm into cells of irregular shape. The result consisted of a high frequency of abnormal products of meiosis. Quadrivalents were observed in diakinesis at low frequency, which suggests a segmental allotetraploid and the inability of both genomes to co‐ordinate their activities, leading to multiple spindle and precocious cellularization. In spite of abnormal meiotic products reducing pollen fertility, seed production was normal. Enough normal pollen was available to fertilize the central‐cell nucleus of the embryo sac and produce normal endosperm in this pseudogamous aposporous apomictic accession.