bluuebunny/crossref_metadata_2025_split huggingface dataset:
Asymmetric cell division in human leukemic promyelocytic cells (HL‐60).
Authors: Matsuhisa Tadao 
Published: October 2002

AbstractSmall cells accounted for 8‐9% of the human leukemic promyelocytic cells (HL‐60). The diameter of the small cells was 8.44 μm, whereas that of the large cells, which were heterogeneous in cell size, was 11.0 μm. The small cells were produced from the large cells through asymmetric cell division, which was demonstrated by cloning experiments and by microscopy.
Combined application of in vivo UV‐crosslinking and in vitro label transfer in the examination of AU‐rich sequence binding protein ‐ RNA interactions.
Authors: Henics Tamás , Nagy Eszter , Rigby William F. C. 
Published: October 2002

AbstractA combination of in vivo UV light‐induced crosslinking of nucleic acids to proteins and in vitro label transfer assay was applied to investigate specific interactions between AU‐rich sequences (ARE) in the 3′ UTR of lymphokine mRNAs and cytoplasmic AU‐rich sequence element binding proteins (AUBP) in normal human lymphoblasts and MLA 144 gibbon lymphoid tumor cells. We demonstrate that a pool of cytoplasmic AUBP can be effectively crosslinked to RNA in vivo, suggesting a close association of these proteins with ARE sequences in the cytoplasm. We also show that the UV‐crosslinked AUBP pool is markedly reduced in malignantly transformed MLA 144 cells compared with normal lymphoblasts, indicating weaker interaction between lymphokine ARE and AUBP in these tumor cells. Similar differences in AUBP‐RNA associations were found between the membrane‐bound polysomal subfractions of the two cell types where most of the AUBP activity was localized. We suggest that the decreased AUBP‐mRNA association in MLA 144 cells might reflect a process concerned with disturbances of mRNA metabolism in the neoplastic phenotype.
KERATINS AND SKIN DISORDERS
Authors: RAO SRIDHAR K. , BABU RAJA K. K. , GUPTA P. D. 
Published: October 2002

AbstractThe epidermal keratinocytes express two major pairs of keratin polypeptides. One pair (K5/K14) expressed specifically in basal generative compartment and the other (K1/K10) expressed specifically in the differentiating suprabasal compartment. The switch in the expression of the keratins from proliferating to differentiating compartment indicates the changes that occur in the keratin filament organization which in turn influences the functional properties of the epidermis. Proper regulation of keratin gene expression and the filament organization are absolutely necessary for normal functioning of the skin. Keratin gene mutations can influence the filament integrity thereby causing several heritable blistering disorders of the skin such as epidermolysis bullosa, bullous icthyosiform erythroderma, etc. Changes in the keratin gene expression may lead to incomplete differentiation of the epidermal keratinocyte, causing hyperproliferative diseases of the skin such as psoriasis, carcinomas, etc. This review briefly describes the changes in keratin structure or gene expression that are known to result in various disorders of the skin.
PLANT MITOSIS PROMOTING FACTOR DISASSEMBLES THE MICROTUBULE PREPROPHASE BAND AND ACCELERATES PROPHASE PROGRESSION IN TRADESCANTIA
Authors: HUSH JULIA , WU LIPING , JOHN PETER C. L. , HEPLER LUKAS H. , HEPLER PETER K. 
Published: October 2002

AbstractThe regulation of mitosis in higher plant cells has been investigated by microinjecting protein kinase from the metaphase‐arresting (met1) mutant ofChlamydomonas. Biochemical characterization of this enzyme complex confirms the presence of a p34cdc2/cyclin B‐like kinase. The enzyme was injected into living stamen hair cells ofTradescantia virginianain which microtubules (MTs) were visualized using fluorescent analogue cytochemistry and confocal laser scanning microscopy. Microinjection of this p34cdc2/cyclin B‐like kinase caused rapid disassembly of the preprophase band of MTs but not of interphase‐cortical, spindle or phragmoplast MTs. Effects of the enzyme on the cytomorphology of live prophase cells were also monitored using video microscopy. We found that injection of this enzyme accelerated chromatin condensation and nuclear envelope breakdown. This indicates the presence and function in plants of an enzyme that can initiate nuclear division similar to the maturation or mitosis promoting factor (MPF) of animal cells. These studies provide the first direct evidence that the mitotically‐active form of plant MPF can drive disassembly of preprophase band MTs, chromosome condensation and initiation of mitosis in plant cells.
TRANSPORT OF GLUTATHIONE S‐CONJUGATES IN THE YEASTSSACCHAROMYCES CEREVISIAE
Authors: ŻĄDZIŃSKI ROLAND , MASZEWSKI JANUSZ , BARTOSZ GRZEGORZ 
Published: October 2002

AbstractTransport of 2,4‐dinitrophenyl‐S‐glutathione (DNP‐SG) and a fluorescent glutathione S‐conjugate, bimane‐S‐glutathione (B‐SG) was studied in the baker's yeasts (S. cerevisiae). Both conjugates were exported from the cells; the transport was inhibited by fluoride and vanadate like in mammalian cells. B‐SG was also found to be accumulated in the vacuoles. The transport rate of DNP‐SG outside the cell was higher in a vacuolar‐deficient strain. A significant ATP‐dependent uptake of (3H)‐DNP‐SG by vacuoles was found. These results indicate thatS. cerevisiaetransport glutathione S‐conjugates both outside the cells and into the vacuoles.
INSULIN PRODUCES A BIPHASIC RESPONSE INTETRAHYMENA THERMOPHILABY STIMULATING CELL SURVIVAL AND ACTIVATING PROLIFERATION IN TWO SEPARATE CONCENTRATION INTERVALS
Authors: CHRISTENSEN SØREN T. , QUIE HELENE , KEMP KÅRE , RASMUSSEN LEIF 
Published: October 2002

AbstractCells ofTetrahymenamay produce autocrine signal molecules with effects on survival and proliferation. Here we have tested the effects of human recombinant and bovine insulin, and the B22–B30 fragment of bovine insulin over a wide range of concentrations (10−5–10−18m) on cell survival and proliferation in a synthetic nutrient medium. The cells were grown in conical flasks at low initial cell densities (40 and 400cells/ml). Insulin prevented rapid cell death and/or promoted cell proliferation over two separate concentration ranges: down to nanomolar levels and again in the low pico‐ and femtomolar range. At an initial population density of 400cells/ml the cells multiplied at both concentration intervals. At 40 or fewer organisms/ml the cells multiplied in the high concentration interval, whereas in the low interval they survived for about four times longer than those in the control cultures. B22–B30 added to cultures of 40 initial cells/ml produced a stimulation of cell survival in the low pico‐ and high femtomolar range. In the presence of hemin (50nm) cells at 400 initial organisms/ml multiplied at insulin concentrations down to about 3nmand again from 300amto 10pm. In some cases, hemin plus insulin activated cell proliferation between the two concentration intervals as well. At 40cells/ml the cells not only survived but proliferated in the femtomolar range. Cells in cultures supplemented with both hemin and B22–B30 multiplied at the low concentration interval (from about 100fmto 10pm).
MOSQUITO LARVAE EXTRACT INDUCES MITOTIC RATE ALTERATIONS OF MICE TONGUE KERATINOCYTES ALONG A CIRCADIAN RHYTHM PERIOD
Authors: RONDEROS J. R. , RICCILLO F. L. , OTTINO A. 
Published: October 2002

AbstractIt has been demonstrated that the crude extract of mosquito larvae alters the mitotic rate of several mouse cell populations of young growing mice (25±1 days old). Furthermore, the dialysed fraction of the extract inhibited proliferation of hepatocytes from hepatectomized adult male mice (90 days old). Sampling during the period between 16 and 24 h after treatment (when mitotic peak normally occurs) shows an inhibiting effect on the G1/S interphase, whereas evaluation during the dark phase of the circadian rhythm period (i.e. 4 to 12 h after treatment) shows an increment of the mitotic rates suggesting a probable effect at G2/M restriction point. In the present paper we report the effect of the mosquito larvae crude extract on the proliferative activity of tongue keratinocytes along a circadian rhythm period. Treatments were intra‐peritoneally applied at 16/00 Time of Day/Time Post Injection and mice were killed at 00/08, 04/12, 08/16, 12/20 and 16/24 TD/TPI. As other cell populations previously analysed, the mitotic rate of tongue keratinocytes of extract receivers was significantly increased during night (when S phase normally occurs) and inhibited during the 08/16 to 16/24 period.
CHARACTERIZATION OF THE Na+K+‐ATPase IN ISOLATED BOVINE ARTICULAR CHONDROCYTES; MOLECULAR EVIDENCE FOR MULTIPLE α AND β ISOFORMS
Authors: MOBASHERI A. , ERRINGTON R. J. , GOLDING S. , HALL A. C. , URBAN J. P. G. 
Published: October 2002

AbstractWe have used isoform‐specific antibodies against the Na+K+‐ATPase αα1, α2 and α3) and ββ1 and β2) subunit isoforms in order to establish their specific localization in isolated bovine articular chondrocytes. Immunoblotting confirmed the presence of the α1 and α3 isoforms, although α1 expression was significantly greater than α3 as assessed by immunofluorescence confocal laser scanning microscopy and PCR. A similar approach revealed the presence of the β1 and β2 isoforms in chondrocytes, although β2 immunostaining on the plasma membrane was more punctate than β1 which in contrast predominated in a subcellular compartment. The plasma membrane abundance of the Na+K+‐ATPase was found to be sensitive to the extracellular ionic concentration and long‐term elevation of extracellular Na+concentration significantly upregulated Na+K+‐ATPase density as measured by specific3H‐ouabain binding. Our observations suggest that the expression of α3 and β2 is not restricted to excitable tissues as previously reported. The physiological relevance of α3 expression in chondrocytes may be related to its low affinity for intracellular Na+in an extracellular environment where Na+concentration is unusually high (260–350mm) compared to other cell types (140mm). Glycoproteins and their branched carbohydrates have been implicated in cell recognition events, thus the β2 subunit glycoprotein may allow the chondrocyte to detect changes in its extracellular environment by physically interacting with components of the cellular cytoskeleton and matrix macromolecules.
PPRAS1 PPRAS2ANDPPRAP1GENES, MEMBERS OF ARASGENE FAMILY FROM THE TRUE SLIME MOLDPHYSARUM POLYCEPHALUMARE DEVELOPMENTALLY REGULATED
Authors: KOZLOWSKI PIOTR , TRZCINSKA‐DANIELEWICZ JOANNA , URBANCZYK AGNIESZKA , TOCZKO KAZIMIERZ 
Published: October 2002

AbstractThe expression patterns of two truerasgenes,Ppras1andPpras2and onerapgene,Pprap1were examined in fourPhysarum polycephalumdevelopmental stages: uninucleate amoebae, plasmodia (multinucleate syncytia), spherules (a vegetative, dormant stage) and fruiting bodies.Ppras1andPprap1are expressed in all stages examined with the maximum levels of their transcripts in amoebae and fruiting bodies, respectively, and the minimum levels in plasmodia, whereas thePpras2transcript is only detectable in amoebae and fruiting bodies. The results obtained indicate thatP. polycephalumis an organism possessing a developmentally regulatedrasgene family and presents a convenient system to study the role ofras/rapgenes in control of growth and differentiation of lower eukaryotic organisms.
HISTOCHEMISTRY OF OXIDASES IN SEVERAL TISSUES OF BIVALVE MOLLUSCS
Authors: CANCIO IBON , CAJARAVILLE MIREN P. 
Published: October 2002

AbstractVarious tissues of the marine bivalveMytilus galloprovincialiswere analysed histochemically for oxidases capable of generating reactive oxygen species (ROS) using the cerium‐DAB technique. Incubations were performed on unfixed cryostat sections using polyvinyl alcohol and semipermeable membranes. High xanthine oxidoreductase andd‐amino acid oxidase (DAOX) activities were observed in kidney epithelial cells of mussels. DAOX also presented a strong activity in all the digestive epithelia. No xanthine oxidase activity was observed in any of the mussel tissues tested suggesting the presence of an enzyme only showing dehydrogenase activity. Mannitol oxidase, associated with special organelles called ‘mannosomes’ of terrestrial gastropods, presented a weak activity in the stomach epithelium and a strong specific activity in the haemocytes. Only DAOX presented a discrete granular distribution compatible with a peroxisomal compartmentalization. No urate oxidase activity could be demonstrated in tissues of mussels. These observations suggest a role for peroxisomes in ROS generation and determine the tissues capable of producing oxygen radicals in the digestive gland. This study raises the question of the behaviour of these enzymes in conditions in which ROS‐generating organic xenobiotics are accumulated in the digestive gland of molluscs.
PROPIONIC ACID STIMULATES SUPEROXIDE GENERATION IN HUMAN NEUTROPHILS
Authors: NAKAO SUMI , MORIYA YOSHIKO , FURUYAMA SHUNSUKE , NIEDERMAN RICHARD , SUGIYA HIROSHI 
Published: October 2002

AbstractShort‐chain carboxylic acids are the metabolic by‐products of pathogenic anaerobic bacteria and are found at sites of infection in millimolar quantities. We previously reported that propionic acid, one of the short‐chain carboxylic acids, induces an increase in intracellular Ca2+([Ca2+]i) in human neutrophils. Here we investigate the effect of propionic acid on superoxide generation in human neutrophils. Propionic acid (10mm) induced inositol 1,4,5‐trisphosphate (IP3) formation and a rapidly transient increase in [Ca2+]i, but not superoxide generation, whereas 1μm formylmethionyl‐leucyl‐phenylalanine (fMLP), a widely used neutrophil‐stimulating bacterial peptide, stimulated not only IP3formation and Ca2+mobilization but also superoxide generation. The IP3level induced by propionic acid was slightly lower than that induced by fMLP. The transient increase in [Ca2+]iinduced by propionic acid immediately returned to the basal level, whereas a sustained increase in [Ca2+]i, which was higher than the basal level, following a transient increase in [Ca2+]iwas induced by fMLP. The peak level induced by propionic acid was lower than that with fMLP. In the absence of extracellular Ca2+, thapsigargin, a potent inhibitor of endoplasmic reticulum Ca2+‐ATPase, induced an increase in [Ca2+]ieven after propionic acid stimulation, but not after fMLP. The Ca2+ionophore A23187 and thapsigargin induced superoxide generation by themselves. Propionic acid enhanced the superoxide generating effect of A23187 and thapsigargin. These results suggest that Ca2+mobilization induced by propionic acid is much weaker than that with fMLP, and propionic acid is able to generate superoxide in the presence of a Ca2+ionophore and a Ca2+influx activator.
IMMUNOSPECIFIC PROTEIN OF 34.5kDa FROM DNA—PROTEIN CROSS‐LINKS INDUCED BY CIS ‐ ANDTRANS ‐DIAMMINEDICHLOROPLATINUM
Authors: Woźniak Katarzyna , Walter Zofia 
Published: October 2002

AbstractCis ‐diamminedichloroplatinum(II) (cis ‐DDP) is one of the most often used anticancer drugs. It is generally accepted that the antitumor activity of the drug results from its interactions with DNA. Trans ‐diamminedichloroplatinum(II) (trans ‐DDP) also binds to DNA effectively, but is clinically ineffective. In the present work the lymphocyte nuclear proteins that participate in DNA—protein cross‐links induced by cis ‐ and trans ‐DDP are investigated. In lymphocytes which are incubated without platinum compounds there are DNA‐binding proteins in the range of 45–71kDa. It is shown that additional proteins of 28, 30, 34.5, 45 and 120kDa are cross‐linked with DNA in lymphocytes after 2‐h incubation with cis ‐DDP at concentrations of 0.1 and 0.5mM. Trans ‐DDP does not bind additional proteins to DNA after the same incubation time. Electrophoretic analysis shows that trans ‐DDP binds much more of the same nuclear proteins to DNA than cis ‐DDP after 12‐h incubation. In this study a test for the identification of 34.5kDa protein is also undertaken. This protein appears in the samples obtained after 12‐h incubation of lymphocytes with cis ‐ and trans ‐DDP at 0.5 and 1mM, especially. The protein of 34.5kDa from cross‐links induced by 1mM trans ‐DDP is recognized by antibodies against the protein of the same molecular weight from the nuclear matrix of the lymphocytes. The results obtained here are discussed in relation to the biological activity of diamminedichloroplatinum isomers.
DNA TOPOISOMERASE ACTIVITIES IN CHINESE HAMSTER RADIOSENSITIVE MUTANTS AFTER X‐RAY TREATMENT
Authors: Pastor Nuria , Cortés Felipe 
Published: October 2002

AbstractIn the last years the attractive hypothesis of a possible involvement of mammalian topoisomerases in DNA repair has been proposed, given their molecular mechanism of action. So far, using asynchronous cultures a lot of controversial results have been reported, without taking into account the frequently dramatic fluctuations of topoisomerase activities depending upon the cell cycle stage and proliferation rate (mainly for topoisomerase II).We have addressed this question making use of G1 synchronous cultures of the Chinese hamster radiosensitive mutants xrs 5 (defective in DNA double strand breaks rejoining) and irs 2 (which shows radioresistant DNA synthesis), as well as their parental lines CHO K1 and V79 respectively, which show a normal radiosensitivity. Cells were irradiated with 5Gy of X‐rays and the activities of topoisomerases I and II in nuclear extracts were studied for comparison with non‐irradiated controls in both the mutants and parental cell lines.Our results clearly show a modulation of the topoisomerase activities after irradiation, that varies depending upon the mutation that the different lines bear.While this hypothesis needs further testing, an interesting idea is that DNA topoisomerases might be involved in the cellular response to radiation damage, either through a direct participation in the repair mechanisms or in a preparative step to allow repair to proceed.
MONOCYTES MODULATE THE IN VITRO BASAL FREQUENCY OF SISTER CHROMATID EXCHANGES OF PLASMA LEUKOCYTE CULTURES AND MITOTIC ACTIVITY OF SUPPRESSOR‐CYTOTOXIC T8 HUMAN LYMPHOCYTES
Authors: Soloneski Sonia M. , Reigosa Miguel A. , Garcia Carlos F. , Larramendy Marcelo L. 
Published: October 2002

AbstractThe effect of monocytes (MNs) on baseline SCEs and kinetics of human lymphocytes in plasma leukocyte (PLCs) and whole blood cultures (WBCs) was studied. Baseline SCEs in PLCs were nearly two‐fold over WBCs. No differences in SCEs were observed between PLCs and MN‐depleted PLCs, indicating that SCEs from PLCs are independent of MNs. MNs titration into PLCs decreased proportionally SCEs. Reconstitution of depleted PLCs with concentration of MNs equivalent or higher than those of PLC decreased SCEs. No variations of lymphocyte kinetics in PLCs were observed in the absence/presence of MNs. The proportion of B and T‐cell subsets among interphasic lymphocytes were similar in PLC in the absence/presence of MNs, but a significant increase in the proportion of mitotic T8 lymphocytes was observed. Accordingly, MNs modulate both the in vitro basal SCEs and the mitotic activity of T8, but not their cell‐cycle kinetics.
Late Pleistocene Glaciation of Mono Basin, California
Authors: Bursik Marcus I. , Gillespie Alan R. 
Published: October 2002

AbstractMoraines in the canyons of Mono Basin are separable into relative-age groups on the basis of clast-sound velocities in exposed boulders, moraine morphology, and weathering features on boulder surfaces. Tioga, Tenaya, Tahoe, and Mono Basin moraine deposits each have distinct weathering characteristics and therefore constitute different relative-age groups. The Tioga glacial episode at June Lake may postdate ∼25,200(?)-yr-old basaltic lavas, and the Tenaya episode may have occurred ∼30,700 yr ago. A comparison of the glacial and lacustrine records of Mono Basin over the past 40,000 yr, based on new interpretations of radiometric ages, is consistent with the hypothesis that maximum glacial and maximum pluvial periods were not necessarily synchronous.
Age Constraints on the Duck Ponds and Limeburner's Point Mammalian Faunas Based on Magnetic Polarity Stratigraphy in the Geelong Area (Victoria), Australia
Authors: Whitelaw Michael John 
Published: October 2002

AbstractNew magnetostratigraphic results may be used to determine the age of two locally important fossil vertebrate faunas near Geelong (Victoria), Australia. Paleomagnetic samples collected from sections located at Limeburner's Point and Limeburner's Bay, together with previously suggested stratigraphic correlations, now constrain the age of the Duck Ponds Local Fauna to be younger than 1.66 myr (and probably greater than 0.98 myr) and the age of the Limeburner's Point Local Fauna to be younger than 0.98 myr. These age determinations enhance the biostratigraphic importance of both local faunas on a continent characterized by a chronic lack of chronologically well-constrained fossil vertebrate localities.
Soil Development Parameters in the Absence of a Chronosequence in a Glaciated Basin of the White Mountains, California-Nevada
Authors: Swanson Terry W. , Elliott-Fisk Deborah L. , Southard Randel J. 
Published: October 2002

AbstractDetailed mapping and provisional numerical age determinations of glacial deposits in the South Chiatovich Creek Basin of the White Mountains provide an opportunity to evaluate the ability of conventional soil parameters to discriminate first- and second-order glacial events. Sampling and analytical procedures were designed to minimize variation in climate and lithology. When lithology and climate are similar among sites, age trends are more pronounced in both field and chemical soil properties. Profile development indices (PDIs), adjusted by removing melanization and pH, systematically increase with greater soil age, and discriminate first-order, but not second-order, glacial events. The best-fit curve for adjusted PDI data assumes an exponential form and suggests that the rate of soil formation in this region decreases over time, similar to the rate of weathering-rind development. Variation in eolian influx and surface erosion, which are dominant processes affecting soils of the basin, cause major uncertainties in establishing soil age and, hence, soil-development rates. Even on the youngest glacial deposits, soil age is probably significantly less than deposit age due to these geomorphic processes. Soil and weathering parameters imply that these field techniques can be inexpensively employed to define relative chronologies and to assess surface degradation and its impact on surface exposure ages. Results from this study indicate that site-selection strategy for establishing glacial chronologies should be reevaluated. Working with stable residual bedrock surfaces and associated low-relief outwash fans and terraces may prove more productive than focusing on relatively unstable moraine surfaces in tectonically active mountain systems.