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  • Artikel  (1.176)
  • Cell & Developmental Biology
  • Surface physics, nanoscale physics, low-dimensional systems
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  • 101
    Digitale Medien
    Digitale Medien
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 56 (1994), S. 47-106 
    ISSN: 0730-2312
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 102
    Digitale Medien
    Digitale Medien
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 56 (1994), S. 309-330 
    ISSN: 0730-2312
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 103
    Digitale Medien
    Digitale Medien
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 56 (1994), S. 77-120 
    ISSN: 0730-2312
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 104
    Digitale Medien
    Digitale Medien
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 56 (1994), S. 265-284 
    ISSN: 0730-2312
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 105
    Digitale Medien
    Digitale Medien
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 56 (1994), S. 97-116 
    ISSN: 0730-2312
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 106
    Digitale Medien
    Digitale Medien
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 56 (1994), S. 65-95 
    ISSN: 0730-2312
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 107
    Digitale Medien
    Digitale Medien
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 54 (1994), S. 343-353 
    ISSN: 0730-2312
    Schlagwort(e): hepatocytes ; pentraxins ; phospholipids ; neutrophils ; tetrapeptides ; wound repair ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: Human C-reactive protein (CRP) is an acute phase blood component that accumulates at sites of tissue damage and necrosis and is degraded by neutrophils to biologically active peptides. A dodecapeptide composed of amino acids 27-38 of CRP mediates cell attachment in vitro. This peptide was designated the cell-binding peptide (CB-Pep) of CRP. Characterization of the interaction between fibroblasts and modified synthetic peptides with sequential deletions from either the N-terminus or C-terminus revealed that the minimal sequence for cell attachment or inhibition of cell attachment to the CB-Pep was Phe-Thr-Val-Cys-Leu, which corresponds to residues 33-37 within each of the five 206 amino acid subunits of CRP. The pentapeptide by itself mediated cell attachment. Substitutions for each residue within the CB-Pep indicated that the critical residues for activity were Phe-33 and Thr-34. This cell-binding pentapeptide represents a recognition motif for cell adhesion not found in other proteins.
    Zusätzliches Material: 7 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 108
    Digitale Medien
    Digitale Medien
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 54 (1994), S. 354-364 
    ISSN: 0730-2312
    Schlagwort(e): cis-hydroxyproline ; rhodamine 123 ; mitochondria ; rat bone marrow ; dexamethasone ; osteoprogenitor cells ; differentiation ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: Mitochondrial response to the effect of a hydroxylase (PH) inhibitor was tested in marrow stromal cells during stimulation of osteoprogenitor cell (OPC) differentiation. The rationale for this was to explore pathways of regulatory interactions between procollagen synthesis and mitochondrial respiration that could be linked to the commitment of OPCs to mineralization. Stimulated OPCs exposed to the PH inhibitor cis-hydroxyproline (cis-HP), compared to the noninhibiting isomer trans-HP, for 11 days showed a dose-dependent decrease in cell proliferation, the surviving cells showed increased alkaline phosphatase activity. Trans-HP did not influence the cis-HP effect on ALP and on proliferation arrest. Short time exposures, 2-3 days, to cis-HP at different periods suggested that Days 0-3 and 3-5 were critical for the commitment to Day 21 mineralization of OPCs. On Days 0-3 cells were most sensitive to cis-HP, since on Day 11, 8 days after removal of cis-HP, they were too scarce to be counted by the staining method. However, the presence of 5.0 mM cis-HP in the cultures during Days 3-5 has induced on Day 21 close to 24-fold more mineralization/cell than controls, compared to the trans-HP effect, which was only close to 3-fold. The presence of cis-HP in the cultures on Days 0-3 has augmented the mitochondrial Day 3 retention of rhodamine 123 (Rho) in the stromal cells, relative to controls, compared to the presence of trans-HP. However, the presence of cis-HP during Days 3-5 or 3-6 resulted in lower Day 5 Rho retention, relative to controls, which was not significantly different from the retention that resulted from trans-HP. Since Rho retention is related to the final result of aerobic respiration level, these results are interpreted as a cis-HP inhibitory effect on procollagen peptidyl-proline hydroxylation, which may in turn release oxygen surpluses, to be available for mitochondrial consumption. The fall in Rho retention responses to cis-HP between Days 0-3 and 3-5 is suggesting either abrupt decrease in proline hydroxylation or poor mitochondrial sensitivity to oxygen in Day 3-5 cultures.
    Zusätzliches Material: 7 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 109
    ISSN: 0730-2312
    Schlagwort(e): interleukin-1 ; prostaglandin E2 ; matrix metalloproteinases ; dermal fibroblasts ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: The degradative effects of interleukin-1 (IL-1) on the extracellular matrix of connective tissue are mediated primarily by metalloproteinases and prostaglandins. Clinical observations suggest that these effects can be prevented, to some extent, by the use of non-steroidal anti-inflammatory drugs. We have examined the role of prostaglandin E2 (PGE2) in IL-1-induced gene expression by human skin fibroblasts in culture. Incubation of confluent fibroblast cultures with varying concentrations (0.01-1.0 μg/ml) of PGE2 led to a dose-dependent elevation of collagenase mRNA steady-state levels, the promoter activity, and the secretion of the protein, whereas relatively little effect was observed on stromelysin and TIMP gene expression. Exogenous PGE2 had no additive or synergistic effect with IL-1 on collagenase gene expression. Furthermore, commonly used non-steroidal anti-inflammatory drugs (indomethacin, acetyl salicylic acid and ibuprofen), at doses which block prostaglandin synthesis in cultured fibroblasts, failed to counteract IL-1-induced collagenase and stromelysin gene expression, nor did they affect TIMP expression. Although the effects of PGE2 did not potentiate those of IL-1 on collagenase gene expression in vitro, one could speculate that massive production of PGE2 by connective tissue cells in vivo in response to inflammatory mediators such as IL-1 or tumor necrosis factor-α, could lead to sustained expression of collagenase in connective tissue cells after clearance of the growth factors.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 110
    Digitale Medien
    Digitale Medien
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 55 (1994), S. 1-3 
    ISSN: 0730-2312
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 111
    Digitale Medien
    Digitale Medien
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 55 (1994), S. 22-31 
    ISSN: 0730-2312
    Schlagwort(e): nuclear skeleton ; DNA organization ; transcriptional regulation ; nuclear structure ; gene regulation ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: Tissue specific regulation of gene expression by a single transcription factor or group of transcription factors cannot be explained simply by DNA sequence alone. For example, in the same animal a particular transcription factor is capable of interacting with DNA in the nucleus of many different cell types, resulting in unique gene expressions despite the presence of a similar genome in all cells. Historically, these differences in response to a single type of factor within target tissues in the same animal have been suggested to occur through different alterations in chromatin structure. Recent, data has demonstrated that combination of hormones and transcription factors working together may cooperatively play a role in the regulation of gene expression [Pearce and Yamamoto (1993): Science 259:1161-1165]. However, the molecular mechanisms of this tissue specific regulation of gene expression still remains largely unexplained. Current evidence suggests that in different cell types the interplay between the specific three-dimensional organization of the genome and the structural components of the nucleus, the nuclear matrix, may accomplish the regulation of specific gene expression. © 1994 Wiley-Liss, Inc.
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 112
    Digitale Medien
    Digitale Medien
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 55 (1994), S. 69-76 
    ISSN: 0730-2312
    Schlagwort(e): differentiation ; nuclear lamina ; intermediate filaments ; nuclear matrix ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: In the age of “virtual reality,” the imperfect microscopic silhouettes of cells and organelles are gradually being replaced by calligraphic computer drawings. In this context, textbooks and introductory slides often depict the cell nucleus as a smooth-shaped, featureless object. However, in reality, the nuclei of different cells possess distinct sizes and morphological features which develop in a programmed fashion as each cell differentiates. To dissect this complex morphogenetic process, we need to identify the basic elements that determine nuclear architecture and the regulatory factors involved. Recently, clues about the identity of these components have been obtained both by systematic analysis and by serendipity. This review summarizes a few recent findings and ideas that may serve as a first forum for future discussions and, I hope, for further work on this topic. © 1994 Wiley-Liss, Inc.
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 113
    Digitale Medien
    Digitale Medien
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 55 (1994), S. 98-105 
    ISSN: 0730-2312
    Schlagwort(e): histone acetylation ; transcriptionally active chromatin ; nuclear matrix ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: Besides its role in organizing nuclear DNA, the nuclear matrix is involved in specific nuclear functions, including replication, transcription, and RNA splicing. It is becoming increasingly evident that nuclear processes are localized to distinct regions in the nucleus. For example, transcriptionally active genes and RNA transcripts are found in discrete transcription foci. Current evidence suggests that nuclear matrix-bound transcriptionally active DNA sequences are in nucleosomes with dynamically acetylated histones. Histone acetylation, which precedes transcription, alters nucleosome and chromatin structure, decondensing the chromatin fibre and making the nucleosomal DNA accessible to transcription factors. Histone acetyltransferase and histone deacetylase, which catalyze this rapid acetylation and deacetylation, are associated with the internal nuclear matrix. We hypothesize that these enzymes play a role in maintaining the association of the active chromatin domains with the internal nuclear matrix at sites of ongoing transcription. © 1994 Wiley-Liss, Inc.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 114
    Digitale Medien
    Digitale Medien
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 55 (1994), S. 93-97 
    ISSN: 0730-2312
    Schlagwort(e): DNA topoisomerase I ; DNA topology ; promoter activation ; in vitro and in vivo nucleosomes ; rotational and translational information ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: Information in DNA is not limited to sequence information. Both local and global conformational parameters are pivotal to the interaction with a number of relevant proteins. The function of the major components of the transcription machinery (RNA polymerase II, DNA topoisomerase I, nucleosomes, the TATA-binding factor) is dependent on the topological status of the substrate DNA molecule. The topological requirements and the conformational consensus that dictate the rules for localization of nucleosomes and define the active sites for DNA topoisomerase I have been established; the reaction of DNA topoisomerase I is regulated by a topological feedback mechanism. The integrating function of the free energy of supercoiling in the transcription process and the regulatory role of DNA topoisomerase I are discussed. © 1994 Wiley-Liss, Inc.
    Materialart: Digitale Medien
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  • 115
    ISSN: 0730-2312
    Schlagwort(e): NK/A-NK cells ; multicatalytic proteinase complex ; proteasome ; proteases ; enzyme purification ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: We have recently described nongranular, cytosolic, high-molecular-weight trypsin-like (A-NKP 1) and chymotrypsin-like (A-NKP 2) proteases of interleukin-2-activated rat natural killer (A-NK) cells. A functional correlation between the inactivation of A-NKP 2 and the inhibition of rat A-NK cell-mediated cytotoxicity was found. Herein we describe the 6,000-fold purification of A-NKP 2 to apparent homogeneity following: isopycnic sucrose gradient fractionation of postnuclear supernatants, molecular sieve chromatography, and heparin-Sepharose® chromatography. We also report the novel finding that A-NKP 2 as well as A-NKP 1, derived from either rat A-NK cells or the rat NK leukemic cell line CRNK-16, are constituents of the multicatalytic proteinase (MCP/proteasome) complexes of these cells. Characteristic biochemical, biophysical, and electron microscopic/ultrastructural similarity to the rat liver proteasome was observed. However, Western blot analysis using polyclonal antibodies to the rat liver proteasome clearly indicated differences in the rat hepatic proteasome and the CRNK-16-derived proteasomal subunits. The identification, characterization, and purification of A-NKP 1 and A-NKP 2, described herein, now allow for further investigation of the potential role of these proteasome components in NK cell function. Moreover, the proteasome of NK and A-NK cells can now be compared and contrasted to the granzymes of lytic granules with respect to their role in cell-mediated cytotoxicity. © 1994 Wiley-Liss, Inc.
    Zusätzliches Material: 7 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 116
    Digitale Medien
    Digitale Medien
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 55 (1994), S. 200-208 
    ISSN: 0730-2312
    Schlagwort(e): cell regulatory sialoglycopeptide ; retinoblastoma protein product ; cell cycling ; phosphorylation ; signal transduction ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: A novel cell regulatory sialoglycopeptide (CeReS-18), purified from the cell surface of bovine cerebral cortex cells has been shown to be a potent and reversible inhibitor of proliferation of a wide array of fibroblasts as well as epithelial-like cells and nontransformed and transformed cells. To investigate the possible mechanisms by which CeReS-18 exerts its inhibitory action, the effect of the inhibitor on the posttranslational regulation of the retinoblastoma susceptibility gene product (RB), a tumor suppressor gene, has been examined. It is shown that CeReS-18 mediated cell cycle arrest of both human diploid fibroblasts (HSBP) and mouse fibroblasts (Swiss 3T3) results in the maintenance of the RB protein in the hypophosphorylated state, consistent with a late G1 arrest site. Although their normal nontransformed counterparts are sensitive to cell cycle arrest mediated by CeReS-18, cell lines lacking a functional RB protein, through either genetic mutation or DNA tumor virus oncoprotein interaction, are less sensitive. The refractory nature of these cells is shown to be independent of specific surface receptors for the inhibitor, and another tumor suppressor gene (p53) does not appear to be involved in the CeReS-18 inhibition of cell proliferation. The requirement for a functional RB protein product, in order for CeReS-18 to mediate cell cycle arrest, is discussed in light of regulatory events associated with density-dependent growth inhibition. © 1994 Wiley-Liss, Inc.
    Zusätzliches Material: 7 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 117
    Digitale Medien
    Digitale Medien
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 55 (1994) 
    ISSN: 0730-2312
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 118
    Digitale Medien
    Digitale Medien
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 55 (1994), S. 287-299 
    ISSN: 0730-2312
    Schlagwort(e): osteocyte ; gap junction ; cytoskeleton ; extracellular matrix ; osteocytic osteolysis ; bone membrane ; functional adaptation ; mechanical loading ; strain ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: Although the structural design of cellular bone (i.e., bone containing osteocytes that are regularly spaced throughout the bone matrix) dates back to the first occurrence of bone as a tissue in evolution, and although osteocytes represent the most abundant cell type of bone, we know as yet little about the role of the osteocyte in bone metabolism. Osteocytes descend from osteoblasts. They are formed by the incorporation of osteoblasts into the bone matrix. Osteocytes remain in contact with each other and with cells on the bone surface via gap junction-coupled cell processes passing through the matrix via small channels, the canaliculi, that connect the cell body-containing lacunae with each other and with the outside world. During differentiation from osteoblast to mature osteocyte the cells lose a large part of their cell organelles. Their cell processes are packed with microfilaments. In this review we discuss the various theories on osteocyte function that have taken in consideration these special features of osteocytes. These are (1) osteocytes are actively involved in bone turnover; (2) the osteocyte network is through its large cell-matrix contact surface involved in ion exchange; and (3) osteocytes are the mechanosensory cells of bone and play a pivotal role in functional adaptation of bone. In our opinion, especially the last theory offers an exciting concept for which some biomechanical, biochemical, and cell biological evidence is already available and which fully warrants further investigations. © 1994 Wiley-Liss, Inc.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 119
    Digitale Medien
    Digitale Medien
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 55 (1994), S. 310-320 
    ISSN: 0730-2312
    Schlagwort(e): osteoblast differentiation ; gene regulation ; signal transduction pathways ; osteocalcin ; bHLH proteins ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: Control of osteoblast growth and development can be characterized from receptor mediated events to nuclear messengers controlling gene transcription. From this analysis it is possible to formulate a model to explain the reciprocal relationship between growth and differentiation as well as differential cytokine modulation of osteoblast function. Central to this model are putative tissue specific transcriptional switches (possibly of the bHLH gene superfamily) that may repress proliferation and permit the regulation of mature osteoblast phenotypic characteristics. This model proposes that in post-mitotic differentiated osteoblasts, tissue specific transcription factors determine the capacity to express osteoblastic characteristic, whereas receptor activated signalling cascades, namely, cAMP/protein kinase A, receptor serine/threonine kinase, and vitamin D receptor-dependent pathways, regulate mature osteoblast-specific gene expression. Activated differentiation switches also may feedback to transcriptionally repress proliferation. Conversely, in preosteoblasts, in which differentiation switches are turned off, distinct signalling cascades involving tyrosine kinases, PKC, and calcium/calmodulin regulate proliferation. Proliferating preosteoblasts also exhibit negative modulation of maturation either through inactivation of putative tissue-specific transcription factors and/or through AP-1 dependent phenotype suppression of genes expressed in mature osteoblast. Thus, the final outcome of transcriptional regulation of osteoblast function results from complex interactions between signalling pathways and permissive differentiating transcription factors. Though many aspects of this model remain speculative and require confirmation, it serves as a useful conceptual framework to further investigate the differential control of osteoblast proliferation and differentiation that may lead to improved pharmacologic ways to manipulate bone formation in vivo. © 1994 Wiley-Liss, Inc.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 120
    Digitale Medien
    Digitale Medien
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 56 (1994), S. 1-3 
    ISSN: 0730-2312
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 121
    Digitale Medien
    Digitale Medien
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 56 (1994), S. 16-22 
    ISSN: 0730-2312
    Schlagwort(e): metastatic carcinoma ; orthotopic model ; immunodeficient host ; pharmacological therapy ; genetic therapy ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: The dissemination of cells from a primary tumor, resulting in the progressive growth of metastatic carcinoma in distant sites, is the most common cuse of death of cancer patients. The observations from clinical studies and the results of experimental studies using rodent tumors and human cancer cells implanted into immunodeficient host animals suggest that metastasis is not a random event, but rather the result of a sequence of selective events, many of which involve interactions with elements of the microenvironment of the primay and metastatic tumors. Analysis of the metastatic potential of a human tumor cell population has been greatly improved by the introduction of orthotopic models of tumor growth and metastasis, which have demonstrated that implanting human tumor cells into the appropriate tissue in an immunodeficient rodent can increase both tumor take and incidence of metastasis. This will be the models that should be used to validate the identity of candidate metastasis-associated genes, and determine the value of new forms of therapy, either genetic of pharmacological, for controlling metastatic cancer growth.
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
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  • 122
    Digitale Medien
    Digitale Medien
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 56 (1994), S. 48-51 
    ISSN: 0730-2312
    Schlagwort(e): oxidative burst ; cancer ; signal transduction ; nitric oxide ; integrins ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: Osteopontin (OPN) serves both a cell attachment function and a cell signalling function via the αvβ3 integrin, in its cell attachment capacity it can promote attachment of both osteolasts to bone hydroxyapatite and various other cell types to basement membrane/extracellular matrix. In its cell signalling capacity it initiates a signal transduction cascade that includes changes in the intracellular calcium ion levels and the tyrosine phosophorylation status of several proteins including paxillin. Effects on gene expression include suppression of the induction of nitric oxide synthase by inflammatory mediators. OPN can also reduce cell oxidant and inhibit the killing of tumor cells by activated macrophages and endothelial cells. We hepothesize that those cancer cells that produce OPN at elevated levels can suppress the oxidative burst, inhibit NO production, and thus protect themselves from killing by specific host cell types.
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
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  • 123
    ISSN: 0730-2312
    Schlagwort(e): DNA/protein interaction ; simple repetitive DNA ; binding domain ; conformation changes ; intron 2 ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: Electrophoretic mobility shift assays reveal that HeLa neuclear proteins bind fast and with measurable affinity to target DNAs containing mixed simple repetitive (gt)n(ga)m stretches. Preincubation of the proteins at elevated temperature prevents the formation of the major DNA/protein complex in favour of several distinct assemblies. A similar pattern of retarded bands was observed employing higher salt concentrations in binding reaction. Thus conformational changes of different proteins appear to influence the complex rather than alternating DNA structures. Separation of the total nuclear extract into a water soluble and an insoluble protein fraction leads to a complete loss of target DNA bindinlg capability of the fractions. The binding capacity is restored by combining the two fractions suggesting that at least two protein components are necessary to form a complex with the target sequence. The proteins can be differentiated into head sensitive, water soluble and temporary stable, water insoluble, respectively. Furthermore, specifically binding polypeptides are not detectable by Southwestern analyses, probably because the essential components are separated during electrophoresis. DNase 1 footpoint analyses yield four different protein binding regions only on the (gt)n(ga)m harbouring strand. The footprints cover larger portions of the mixed simple repeat in addition to a portion 5′ of the (gt)n part. Hence at lealst two nuclear protein components of unknown biological function have to be present simultaneously to protect preferentially the (gt)n(ga)m-containing strand intron 2 in HLA-DRB genes
    Zusätzliches Material: 10 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 124
    Digitale Medien
    Digitale Medien
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 56 (1994), S. 123-148 
    ISSN: 0730-2312
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 125
    Digitale Medien
    Digitale Medien
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 56 (1994), S. 214-253 
    ISSN: 0730-2312
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 126
    Digitale Medien
    Digitale Medien
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 56 (1994), S. 1-46 
    ISSN: 0730-2312
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 127
    Digitale Medien
    Digitale Medien
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 56 (1994), S. 197-307 
    ISSN: 0730-2312
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 128
    Digitale Medien
    Digitale Medien
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 54 (1994) 
    ISSN: 0730-2312
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 129
    Digitale Medien
    Digitale Medien
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 54 (1994), S. 405-414 
    ISSN: 0730-2312
    Schlagwort(e): competence ; progression ; G-1 ; c-Myc ; ODC ; cell cycle ; quiescence ; WI-38 cell ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: A number of cell culture model systems have been used to study the regulation of cell cycle progression at the molecular level. In this paper we describe the WI-38 cell long-term quiescence model system. By modulating the length of time that WI-38 cells are density arrested, it is possible to proportionately alter the length of the prereplicative or G-1 phase which the cell traverses after growth factor stimulation in preparation for entry into DNA synthesis. Through studies aimed at understanding the cause and molecular nature of the prolongation of the prereplicative phase, we have determined that gene expression plays an important role in establishing growth factor “competence” and that once the cell becomes “competent” there is a defined order to the molecular events that follow during the remainder of G-1. More specifically, we have determined that the prolongation represents a delay in the ability of long term quiescent cells to become fully “competent” to respond to growth factors which regulate progression through G-1 into S. This prolongation appears to occur as a result of changes during long term quiescence in the ability of immediate early G-1 specific genes (such as c-myc) to activate the expression of early G-1 specific genes (such as ornithine decarboxylase). While ODC is the first and thus far only growth associated gene identified as a target of c-myc (and the Myc/Max protein complex), it is likely that further studies in this model system will reveal other early G-1 growth regulatory genes. We anticipate that future follow-up studies in this model system will provide additional valuable information abuot the function of growth-regulatory genes in controlling growth factor responsiveness and cell cycle progression.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 130
    ISSN: 0730-2312
    Schlagwort(e): hyaluronan ; heparin ; RHAMM ; locomotion ; glycosaminoglycan binding domains ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: We have previously reported that the hyaluronan (HA) receptor RHAMM (Receptor for Mediated Motility) [Turley et al., 1991] and that HA stimulation of the motility of ras-transformed fibroblasts is mediated via its interaction with RHAMM. Here we show that RHAMM also contains binding sites for heparin (HP) anbd that interaction of HP with these sites can regulates the locomotion of ras-transformed fibroblasts. At low concentrations (0.01 mg/ml), HP inhibited HA-induced locomotion of ras-transformed cells in a manner independent of RHAMM. At higher, but still physioligical concentrations (0.1 mg/ml), HP alone stimulated cell locomotion and this stimulation appeared to be RHAMM-dependent as it was blocked by anti-RHAMM antibodies. Other related glycosaminogolycans such as chondroitin sulfate and dermatin sulfate had no effect on cell motility. In ligand blotting assays, GST-RHAMM fusion protein was shown to bind biotin-labelled HP and this binding was displaceable with unabelled HP. In similar lignad binding analyses conducted with truncations of RHAMM fusion protein, the binding region was found to be localizeed in the same 35 amino acid segment of RHAMM that contains the two HA binding domains. Synthetic peptides corresponding to these HA binding domains were retained on and bound effectively to an HP-Sepharose affinity column. Fusion protein generated by linkage of these peptides to the non-HP binding amino terminus of RHAMM conferred HP binding capacity to the genetically engineered proteins. Conversely, deletion of the HA binding domains of RHAMM resulted in fusion proteins devoid of HP binding activity. The relative affinities of RHAMM for HA and HP, as determined by competition and transblot assays as well as quantification of binding at various salt concentrations, indicated that RHAMM had lower affinity for HP than that for HA. These results demonstrate the existence of new HP binding motif that has biological relevance to locomotion.
    Zusätzliches Material: 10 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 131
    Digitale Medien
    Digitale Medien
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 56 (1994), S. 518-526 
    ISSN: 0730-2312
    Schlagwort(e): Hps47 ; 78 procollagen ; molecular chaperones ; metabolic stress ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: Hps47, Grp78, have been implicated with procellagen maturation events. In particular Hps47 has been shown to blind to nascent procellagen α1(I) chains in the course of synthesis and/or translocation into the endoplasmic reticulum (ER). Although, Hsp47 binding to gelatin and collgen has previsously been suggested to mechanism. The early association of Hps47 with procollagen and its relatively late relese suggested that other chaperones, Grp78 and Grp94, interact successively or concurrently with Hps47. Herein, we examined how these events occurs in cells metabolically stressed by depletion of ATP. In cells depleted of ATP, the releses of Hps47, Grp78, and Grp94 from maturing procollange is delayed. Thus, in cell experiencing metabolic stress, newly synthesized procollagen unable to property fold became stable bound to a complex of molecular chaperones. In that Hps47, Grp78, and Grp98 could be recovered with nascent procollagen and as oligomer in ATP depleted cells suggests that these chaperones function in a series of coupled or successive reactions.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 132
    ISSN: 0730-2312
    Schlagwort(e): osteoblast 24/1 ; receptor ; calcium channels ; vitamin D ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: The Steroid hormon 1α, @5-Dihydroxyvitamin D3 has been shown to expert rapid effect (15 s to 5 min) in osteoblast. These occur in osteoblast-like cells lacking the nuclear vitamin D receptor, ROS 24/1, suggesting that a separate signalling system mediates the rapid action. These non-genomic action include rapid activation of phospholipase C and opening of calcium channels, pointing to a membrane localization of this signalling system. Previous studies have shown that the 1β epimer of 1α25-dihydroxyvitamina D3 can block these rapid action, indicating that the 1β epimer may bind to the recptor responsible for the rapid action sin a competative manner. We have assessed the displacement of 3H-1α,25dihydroxyvitamin D3 by vitamin D compounds, as well as the apparent dissociation constant of 1α25-dihydroxyvitamin D3 and its 1β epimer for the memberane receptor in membrane prepration from ROS 24/1 cells. Increasing concentrations of 1α25-dihydroxyvitamin D3, 7.25 nM to 725 nM, displaced 3H-1α25-dihydrxyvitamin D3 from the membranes with 725 nM of the hormone displacing 40-49% of the radioactivity. Similarly, 1β,25-dihydroxyvitamin D3, 7.25 nM and 72.5 nM, displaced 1α25-dihydroxyvitamin D3 binding while 25-hydroxyvitamin D3, 7.25 nM, did not. The apparent dissociation constant (KD) for 1α25-dihydroxyvitamin D3 was detrermined from displacement of 3H-1α25-dihydroxyvitamin D3 yielding a value of 8.1 × 10-7 M by Scatchard analysis. The KD for the 1β epimer determine from displacement of 3H-1α25-dihydroxyvitamin D3 was 4.8 × 10-7 M. The data suggest the presence of a receptor on the membrane of ROS 24/1 cells that reconize 1α25-dihydroxyvitamin D3 and its 1β epimer, but not 25-dihydroxyvitamin D3. Its ability to reconize the 1β epimer which appears to be a specific anagonist of the rapid effect of the hormone suggests that these studies may be the initial steps in the isolation and characterization of the signalling system mediating the rapid action of vitamin D.
    Zusätzliches Material: 8 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 133
    Digitale Medien
    Digitale Medien
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 56 (1994), S. 550-558 
    ISSN: 0730-2312
    Schlagwort(e): PKC ; TPA ; up-regulation ; down-regulation ; A431 cells ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: The signal transducrion mechanism of protein kinase FA/GSK-3α by tyrosine phosphorylation in A431 cells was investigated. Kinase FA/GSK-3α was found to exist in a highly tyrosine-phosphorylated/activated state in resting cells but could be tyrosine-dephosphorylated and inactivated to ∼60% of the control level when cells were acutely treated with 1 μM tumor phorbol ester (TPA) at 37oC for 30 min, as demonstrated by metabolic 32P-labeling the cells, followed by immunoprecipitation and two-dimensional phosphoamino acid analysis and by immunodetection in an antikinase FA/GSK-3α immunoprecipitate kinase assay. Conversely, when cells were chronically treated with 1 μM TPA at 37°C for 24 h and processed under identical condetions, kinase FA/GSK-3α was found to be rephosphorylated on tyrosine residue and reactivated to ∼130% of the original control level. Taken together, the results provide initial evidence that the phosphotyrosine content and cellular activity of kinase FA/GSK-3α can be modulated in a reversible manner by short-term and long-term exposure of A431 cells to TPA. Since acute exposure of cells to TPA causes up-regulation of cellular protein kinase C (PKC) activity and prolonged exposure to TPA causes down-regulation of PKC, the results further suggest that the TPA-mediated modulation of PKC may play a role in the regulation of tyrosine phosphorylation and concurrent activation of kinase FA/GSK-3α in cells, representing a new mode of signal transduction pathway for the regulation of this multisubstrate/multifunctional protein kinase in cells.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 134
    Digitale Medien
    Digitale Medien
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 56 (1994) 
    ISSN: 0730-2312
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 135
    Digitale Medien
    Digitale Medien
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 55 (1994) 
    ISSN: 0730-2312
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 136
    Digitale Medien
    Digitale Medien
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 55 (1994), S. 445-464 
    ISSN: 0730-2312
    Schlagwort(e): two-dimensional gel electrophoresis ; actin phosphorylation ; MAP kinase ; cytoskeletal protein phosphorylation ; scatter factor ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: Hepatocyte growth factor (HGF) and epidermal growth factor (EGF) are major hepatacyte mitogens, but HGF, also known as scatter factor (SF), has also been shown as a potent motogen for epithelial and endothelial cells. The mechanisms by which HGF is a stronger motogen compared to other mitogens are not understood. Here we report a comparative study of the effect of the two growth factors on cultured primary rat hepatocytes regarding their differential effects on morphology, mitogenicity, and motility as well as the phosphorylation of cytoskeletal-associated proteins. Using three different motility assays, both HGF and EGF increased the motility of hepatocytes, but HGF consistently elicited a significantly greater motility response than EGF. Additionally, HGF induced a more flattened, highly spread morphology compared to EGF. To examine if HGF and EGF phosphorylated different cytoskeletal elements as signal transduction targets in view of the observed variation in morphology and motility, primary cultures of 32P-loaded rat hepatocytes were stimulated by either HGF or EGF for up to 60 min. Both mitogens rapidly stimulated four isoforms of MAP kinase with similar kinetics and also rapidly facilitated the phosphorylation of cytoskeletal-associated F-actin. Two cytoskeletal-associated proteins, however, were observed to undergo rapid phosphorylation by HGF and not EGF during the time points described. One protein of 28 kDa was observed to become phosphorylated fivefold over controls, while the EGF-stimulated cells showed only a slight increase in the phosphorylation of this protein. Another protein with an apparent mwt of 42 kDa was phosphorylated 20-fold at 1 min and remained phosphorylated over 50-fold over control up to the 60 min time point. This protein was observed to become phosphorylated by EGF only after 10 min, and to a lesser extent (20-fold). Taken together, the data suggest that HGF and EGF stimulate divergent as well as redundant signal transduction pathways in the hepatocyte cytoskeleton, and this may result in unique HGF- or EGF-specific motility, morphology, and mitogenicity in hepatocytes. © 1994 Wiley-Liss, Inc.
    Zusätzliches Material: 10 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 137
    Digitale Medien
    Digitale Medien
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 55 (1994), S. 477-485 
    ISSN: 0730-2312
    Schlagwort(e): phospholipase C ; inositol trisphosphate ; diacylglycerol ; tyrosine kinase ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: The production of the second messenger molecules diacylglycerol and inositol 1,4,5-trisphosphate is mediated by activated phosphatidylinositol-specific phospholipase C (PLC) enzymes. We report the enhancement of the phosphoinositide metabolism pathway in KMS-4 and KMS-8 cells, both of which are human colorectal carcinoma cell lines derived from familial adenomatous polyposis patients. In these cells, the cellular contents of diacylglycerol and inositol 1,4,5-trisphosphate were constitutively increased and the PLC activity in vitro was significantly high, as compared with those in normal colon cells or in other sporadic colorectal carcinoma cells. Northern and Western analyses showed the high expression levels of both PLC-γ1 and PLC-δ1 in KMS-4 and KMS-8 cells. Moreover, we detected the enhancement of protein-tyrosine kinase activity and tyrosine phosphorylation of PLC-γ1 in these KMS cells. These results suggest the involvement of activated phosphoinositide signaling pathways in the colorectal tumorigenesis of familial adenomatous polyposis. © 1994 Wiley-Liss, Inc.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 138
    Digitale Medien
    Digitale Medien
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 55 (1994), S. 465-476 
    ISSN: 0730-2312
    Schlagwort(e): Xenopus laevis ; ras-p21 ; Ser/Thr kinases ; GVBD ; MAP kinase ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: Induction of mitosis in Xenopus laevis oocytes by hormones and the oncogenic ras-p21 protein has been shown to correlate with a cascade of phosphorylations of the Ser/Thr family of kinases. However, the exact hierarchy of enzymes and their mutual interdependency has not been fully elucidated yet. We have used the Xenopus laevis system to investigate the mechanism of activation of the Ser/Thr kinases cascade and their relationship. Comparison between progesterone-induced germinal vesicle breakdown (GVBD), a hallmark of mitosis in oocytes, to that triggered by ras-p21, revealed the existence of at least two independent mechanisms to activate the MAP kinase enzyme in vivo. While progesterone function is dependent of cdc2 protein kinase activity, ras-p21 is independent of this enzyme. However, both progesterone and ras-p21 converge at the MAP kinase level, and depletion of MAP kinase activity inhibits the GVBD and S6 kinase II activation induced by both progesterone and ras-p21. These results provides further evidence that MAP kinase is a critical step for regulation of the cell cycle in oocytes and a critical point where ras and progesterone signaling converge. © 1994 Wiley-Liss, Inc.
    Zusätzliches Material: 8 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 139
    Digitale Medien
    Digitale Medien
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 55 (1994), S. 486-495 
    ISSN: 0730-2312
    Schlagwort(e): Metallothionein ; gene expression ; Leydig cell ; Sertoli cell ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: The presence and inducibility of the major cadmium (Cd) chelating protein metallothionein (MT) in testicular cells has been controversial. In this study, the induction and production of MT in testicular cells were studied using mouse Leydig and Sertoli cell lines. Metal accumulation was studied by subjecting the cells to increasing levels of Cd. The presence of transcription factors for MT synthesis was analyzed by transfecting the cells with a reporter gene under the control of the MT promoter. The dose- and time-dependent induction of MT were conducted by Northern analyses. Expression of MT genes occurred in both Leydig and Sertoli cells. To avoid cross hybridization of the MT probe with mRNAs encoding testicular metal binding proteins and to investigate the integrity of MT mRNA, isoMT mRNA identification and primer extension experiments were performed. Those studies show that the induced mRNA indeed encodes MT. The biosynthesis of MT was confirmed by following 35S-cysteine incorporation into the protein. Finally, cadmium tolerance of testicular cells is compared with that of fibroblast cells. By these studies, we conclude that the MT genes are functional and inducible in testicular cells. © 1994 Wiley-Liss, Inc.
    Zusätzliches Material: 9 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 140
    Digitale Medien
    Digitale Medien
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 55 (1994), S. 496-502 
    ISSN: 0730-2312
    Schlagwort(e): staurosporine ; protein kinases ; collagenase ; AP-1 ; gene induction ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: The indol alkaloid staurosporine is a potent inhibitor of protein kinase C, but has also been shown to have certain effects paradoxically similar to those of protein kinase C-activating phorbol esters. We show here that collagenase mRNA expression is stimulated by 10 nM staurosporine in normal and ras-oncogene-transformed rat fibroblasts. The kinetics of collagenase mRNA induction by staurosporine were slow compared to induction by phorbol ester. Staurosporine induction of the collagenase promoter appeared to be mediated via the TPA response element (TRE). Induction did not involve any increase in jun mRNA expression and did not require expression of c-Jun. Prolonged treatment with phorbol ester to deplete protein kinase C did not inhibit stimulation of the collagenase promoter by staurosporine. Instead, involvement of cAMP-dependent protein kinase (PKA) was indicated by inhibition of staurosporine induction by the PKA inhibitor H-89. In addition, raised levels of cAMP were observed during the first hour of staurosporine treatment. Altogether, our data indicate that staurosporine induces a PKA-dependent pathway leading to c-Jun-independent activation of the collagenase TRE element. © 1994 Wiley-Liss, Inc.
    Zusätzliches Material: 7 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 141
    Digitale Medien
    Digitale Medien
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 55 (1994), S. 503-512 
    ISSN: 0730-2312
    Schlagwort(e): cell cycle ; immediate-early competence genes ; antisense ; mitotic selection ; Swiss 3T3 cells ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: The proto-oncogenes c-fos and c-jun have been shown in numerous model systems to be induced within minutes of growth factor stimulation, during the G0/G1 transition. In this report we use the mitotic shake-off procedure to generate a population of highly synchronized Swiss 3T3 cells. We show that both of these immediate-early, competence genes are also induced during the M/G1 transition, immediately after completion of mitosis. While c-fos mRNA levels drop to undetectable levels within 2 hr after division, c-jun mRNA levels are maintained at a basal level which is ∼ 30% maximum throughout the remainder of G1. In order to access the functional significance of these patterns of c-fos and c-jun expression, antisense oligodeoxynucleotides specific to c-fos or c-jun were added to either actively growing Swiss 3T3 cells or mitotically synchronized cells, and their ability to inhibit DNA synthesis and cell division determined. Our results show that treatment of Swiss 3T3 cells with either c-fos or c-jun antisense oligodeoxynucleotides, while actively growing, during mitosis, or in early G1, results in a reduction in ability to enter S and subsequently divide. This was also true if Swiss 3T3 cells were treated during mid-G1 with c-jun antisense oligodeoxynucleotides. These results demonstrate that the regulation of G1 progression following mitosis is dependent upon the expression and function of the immediate-early, competence proto-oncogenes c-fos and c-jun. © 1994 Wiley-Liss, Inc.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 142
    Digitale Medien
    Digitale Medien
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 55 (1994) 
    ISSN: 0730-2312
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 143
    ISSN: 0730-2312
    Schlagwort(e): muscle ; myogenesis ; Space Shuttle ; cell culture ; microgravity ; neoplastic transformation ; cartridge ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: Myoblast cell cultures have been widely employed in conventional (1g) studies of biological processes because characteristics of intact muscle can be readily observed in these cultured cells. We decided to investigate the effects of spaceflight on muscle by utilizing a well characterized myoblast cell line (L8 rat myoblasts) as cultured in the recently designed Space Tissue Loss Flight Module “A” (STL-A). The STL-A is a “state of the art,” compact, fully contained, automated cell culture apparatus which replaces a single mid-deck locker on the Space Shuttle. The L8 cells were successfully flown in the STL-A on the Space Shuttle STS-45 mission. Upon return to earth, reculturing of these spaceflown L8 cells (L8SF) resulted in their unexpected failure to fuse and differentiate into myotubes. This inability of the L8SF cells to fuse was found to be a permanent phenotypic alteration. Scanning electron microscopic examination of L8SF cells growing at 1g on fibronectin-coated polypropylene fibers exhibited a strikingly different morphology as compared to control cells. In addition to their failure to fuse into myotubes, L8SF cells also piled up on top of each other. When assayed in fusion-promoting soft agar, L8SF cells gave rise to substantially more and larger colonies than did either preflight (L8AT) or ground control (L8GC) cells. All data to this point indicate that flying L8 rat myoblasts on the Space Shuttle for a duration of 7-10 d at subconfluent densities results in several permanent phenotypic alterations in these cells. © 1994 Wiley-Liss, Inc.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 144
    Digitale Medien
    Digitale Medien
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 55 (1994), S. 513-529 
    ISSN: 0730-2312
    Schlagwort(e): transcription factors ; nuclear matrix ; MARs ; transcriptional enhancers ; curved DNA ; positioned nucleosomes ; origins of replication ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: Nuclear matrix is a nuclear protein-DNA superstructure believed to be the exclusive site of DNA replication, transcription, repair, and recombination. The attachment regions of chromatin loops to the nuclear matrix, called MARs, nest origins of replication, have transcriptional enhancer activity, and via their interaction with protein transcription factors may govern gene switch during development and tissue-specific gene expression. In this study the 967 bp MAR of the chicken α-globin gene is analyzed for the presence of hexanucleotides from a number (83 in total) of vertebrate protein transcription factors and core origins of replication. A total number of 760 hexanucleotides from factor sites or origins of replication were used for this search. We found that: (1) The occurrence of protein transcription factor binding sites overall on the MAR fragment as well as on the enhancer and promoter regions of other genes is only about 1.2-1.5 times higher than in random DNA, something consistent for all MAR and enhancer sequences examined. However, a high concentration (up to 2.7 times over random sequences) of hexanucleotide factor sites is observed on small stretches of the α-globin gene MAR. (2) Some regulatory protein binding sites are underrepressented whereas others are overrepresented, giving to an MAR a particular transcription factor flavor. (3) The DNA curvature map of the MAR sequence and the potential sites of positioned nucleosomes suggest the sites where a competition between core histone octamers and protein transcription factors for DNA might be found. This approach might provide a novel technique to diagnose for the regulatory or nonregulatory function of a stretch of DNA. Furthermore, MARs are proposed to constitute important regulatory elements of genes in addition to enhancers, promoters, silencers, locus control regions, and origins of replication. Additional parameters such as interaction of a transcription factor with other transcription factors fixed at vicinal sites, DNA methylation, intrinsic DNA curvature torsional strain, and nucleosome positioning might also determine the high-affinity binding of a transcription factor to its functional sites and its exclusion from or low affinity binding to other nonregulatory regions. © 1994 Wiley-Liss, Inc.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 145
    Digitale Medien
    Digitale Medien
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 55 (1994), S. 1-11 
    ISSN: 0730-2312
    Schlagwort(e): pyruvate dehydrogenase complex ; pyruvate dehydrogenase kinase ; pyruvate dehydrogenase phosphatase ; hexokinase ; phosphofructokinase 1 ; phosphofructokinase 2 ; glucose 6-phosphatase ; Cori cycle starvation ; diabetes ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: Glucose is essential for the energy metabolism of some cells and conservation of glucose is obligatory for survival during starvation. The principal site of this glucose conservation is the mitochondrial pyruvate dehydrogenase (PDH) complex, which is regulated by reversible phosphorylation (phosphorylation is inactivating). In cells in which glucose oxidation is switched off during starvation, fatty acids are used as fuel, and acetyl CoA and NADH formed by β-oxidation promote phosphorylation of PDH complex by activation of PDH kinase. A longer-term mechanism further increases PDH kinase activity in response to cAMP and products of β-oxidation of fatty acids. Coordinated inhibition of glycolytic flux mediated by effects of citrate on PFK1 and PFK2 in muscles and liver results in an associated inhibition of glucose uptake. Similar mechanisms lead to impaired glucose oxidation in diabetes. © 1994 Wiley-Liss, Inc.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
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  • 146
    Digitale Medien
    Digitale Medien
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 56 (1994) 
    ISSN: 0730-2312
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 147
    ISSN: 0730-2312
    Schlagwort(e): amylin ; adenylate cyclase ; kinetics ; mnemonical ; negative co-operativity ; cyclic AMP ; hepatocytes ; CGRP ; G-protein ; Gi-2 ; guanine nucleotide regulatory protein ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: Challenge of intact hepatocytes with amylin only succeeded in elevating intracellular cyclic AMP levels and activating phosphorylase in the presence of the cAMP phosphodiesterase inhibitor IBMX. Both amylin and CGRP similarly activated adenylate cyclase, around 5-fold, although ∼ 400-fold higher levels of amylin were required to elicit half maximal activation. Amylin activated adenylate cyclase though apparently simple Michaelin kinetics whereas CGRP elicited activation by kinetics indicative of apparent negative co-operativity. Use of the antagonist CGPP(8-37) showed that both CGRP and amylin activated hepatocyte adenylate cyclase through a common receptor by a mnemonical mechanism where it was proposed that the receptor co-existed in interconvertible high and low affinity states for CGRP. It is suggested that this model may serve as a paradigm for G-protein linked receptors in general. Amylin failed to both stimulate inositol phospholipid metabolism in hepatocytes and to elicit the desensitization of glucagon-stimulated adenylate cyclase. Amylin did, however, elicit the phosphorylation of the inhibitory guanine nucleotide regulatory protein Gi-2 in hepatocytes and prevented the action of insulin in reducing the level of phosphorylation of this G-protein. © 1994 Wiley-Liss, Inc.
    Zusätzliches Material: 9 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 148
    Digitale Medien
    Digitale Medien
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 56 (1994), S. 29-36 
    ISSN: 0730-2312
    Schlagwort(e): chicken plasma clot ; histoiphysiologic gradient culture ; neoplastic blockade ; collagen waffle membrane ; epithelial tissues ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: The biology of animal cells is often studied in individual cells or in sheets of cells. The relevance of such studies to the intact animal is unclear, since the spatial conditions encountered by cells in animals is one of dense three-dimensional masses of cells, with limits to migration, and with gradients both of diffusion of metabolites and morphologic maturation. These spatial requisites have gradually been met in culture. A brief account describes sponge matrix culture for three-dimensional growth and unilaminar, bilaminar, and radial histophysiologic gradient cultures. Some of the common neoplastic abnormalities of surface epithelial issues are considered. Proposals for investigating the histokinetic mechanisms regulating some epithelial tissue processes are suggested. In the most recent development of gradient culture methods, a thin transparent collagen membrane is intrinsically strengthened by producing a waffle membrane pattern for histophysiologic gradient culture.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 149
    ISSN: 0730-2312
    Schlagwort(e): melanoma ; TNFα ; isolation perfusion ; melphalan ; interferon-γ ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: Recombinant tumor necrosis factor-alpha (rTNFα) has potent antitumor activity in experimental studies on human tumor xenografts. However, in humans, the administration of rTNFα is hampered by severe systemic side-effects. The maximum tolerated dose range from 350 to 500 mg/m2, which is at least 10-fold less than the efficient dose in animals. Isolation perfusion of the limbs (ILP) allows the delivery of high dose rTNFα in a closed system with acceptable side-effects. A protocol with a triple-drug regimen was based on the reported synergism of rTNFα with chemotherapy, with interferon-y, and with hydperthermia. In melanoma-in-transit metastases (stage IIIA or AB) we obtained a 91% complete response, compared with 52% after ILP with melphalan alone. Release of nanograms levels of TNFα in the systemic circulation was evident but control of this leakage and appropriate intensive care resulted in acceptable toxicity. Angiographic, immunohistological, and immunological studies suggest that the efficacy of this prtocol is due to a dual targeting: rTNFα activates and electively lyses the tumor endothelial cells while melphalan is mainly cytoxic to the tumor cells. ILP with rTNFα appears to be a useful model for studying the biochemotherapy of cancer in man.
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
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  • 150
    Digitale Medien
    Digitale Medien
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 56 (1994) 
    ISSN: 0730-2312
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 151
    Digitale Medien
    Digitale Medien
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 56 (1994), S. 143-144 
    ISSN: 0730-2312
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 152
    Digitale Medien
    Digitale Medien
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 56 (1994), S. 145-146 
    ISSN: 0730-2312
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 153
    Digitale Medien
    Digitale Medien
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 56 (1994), S. 168-170 
    ISSN: 0730-2312
    Schlagwort(e): abzyme ; bacteriostatic agent ; bioactive material ; biomimetic structure ; biosensor ; blood coagulation ; ceramic ; coating ; combinatorial synthesis ; drug delivery ; encapsulation ; enzyme ; extracorporeal device ; genetic engineering ; implant ; in vitro enolution ; LB film ; liqid ; liposome ; molecular imprinting ; molecular machine ; nanostructure ; orthopedics ; porey ; engineering ; sensor ; silk ; S-layer ; surface ; smart material ; synthetic chemistry ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: Materials that mimic or extend the properties of natural molecules are being developed for medical appoications. Recent breakthroughs in genetic engineering, polymer synthesis, molecular self-assmbly and related areas are greatly expanding the variety of structures available for use in physiological settings.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 154
    Digitale Medien
    Digitale Medien
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 55 (1994), S. 209-217 
    ISSN: 0730-2312
    Schlagwort(e): alkaline phosphatase ; β-lactamase ; carbonyl cyanide 3-chlorophenylhydrazone ; membrane insertion ; membrane translocation ; protein transport ; sodium azide ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: In order to titrate the dependence of individual steps in protein transport on signal peptide hydrophobicity, we have examined a series of mutants which involve replacement of the hydrophobic core segment of the Escherichia coli alkaline phosphatase signal peptide. The core regions vary in composition from 10:0 to 0:10 in the ratio of alanine to leucine residues. Thus, a nonfunctional polyalanine-containing signal peptide is titrated with the more hydrophobic residue, leucine. Analysis of this series identified a midpoint for rapid precursor processing between alanine to leucine ratios of 6:4 and 5:5 [Doud et al. (1993): Biochemistry 32:1251-1256]. Examination of precursors that are processed more slowly indicates a lower limit of signal peptide hydrophobicity that permits membrane association and translocation. Analysis of precursors that are processed rapidly defines an intermediate range of hydrophobicity that is optimum; above this level precursors become insensitive to transport inhibitors such as sodium azide and carbonyl cyanide 3-chlorophenylhydrazone (CCCP) in parallel with substantial inhibition of β-lactamase processing. Our data indicate that there is a surprisingly narrow range of signal peptide hydrophobicity which both supports transport of the protein to which it is attached and which does not have such a high affinity for the transport pathway that it disrupts the appropriate balance of other secreted proteins. © 1994 Wiley-Liss, Inc.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
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  • 155
    ISSN: 0730-2312
    Schlagwort(e): steroid receptor ; oviduct ; avian tissues ; protein ; acceptor site ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: The avian oviduct receptor binding factor-1 (RBF-1) is a 10 kDa nuclear matrix protein that was originally identified through its ability to effect high affinity interaction of activated progesterone receptor (PR) with chromatin. In the present study, the RBF-1 is shown to not be restricted to reproductive tissues (e.g., oviduct) but present in all avian tissues examined by Western blot analysis with a monoclonal antibody prepared against purified RBF-1. The heart and pancreas had the highest and lowest RBF-1 levels, respectively; the concentration ranging by ∼ 50-fold in these tissues. The 10 kDa size of the RBF-1 detected in all tissues suggests no significant tissue-specific differences in the protein. This was consistent with the finding that purified hepatic and oviductal RBF-1 have identical amino-terminal sequence. Using a recently isolated cDNA to RBF-1, the levels of RBF-1 mRNA were found to correlate well with the ubiquitous presence of the protein as well as tissue-specific differences in concentration. The presence of RBF-1 in non-progesterone responsive tissues suggests the possibility that RBF-1 may not be specifically involved in PR-DNA interactions but may play a more diverse role, possibly involving other steroid receptors such as the glucocorticoid receptor. © 1994 Wiley-Liss, Inc.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 156
    Digitale Medien
    Digitale Medien
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 55 (1994), S. 304-309 
    ISSN: 0730-2312
    Schlagwort(e): bone ; endothelial cells ; osteoclast ; osteoblast ; cytokines ; free radicals ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: Bone development and remodeling depend on complex interactions between bone-forming osteoblasts, bone-degrading osteoclasts, and other cells present within the bone microenvironment. Balanced control of bone formative and degradative processes is normally carefully maintained in the adult skeleton but becomes uncoupled in the course of aging or in various pathological disease states. Systemic regulators of bone metabolism and local mediators, including matrix molecules, cytokines, prostaglandins, leukotrienes, and other autocrine or paracrine factors, regulate the recruitment, differentiation, and function of cells participating in bone formation and turnover. Although some of these interactions are now understood, many yet remain to be elucidated. Recent studies have begun exploring in detail how vascular endothelial cells and their products function in bone physiology. The findings are revealing that bone vascular endothelial cells may be members of a complex communication network in bone which operates between endothelial cells, osteoblasts, osteoclasts, macrophages, stromal cells, and perhaps other cell types found in bone as well. Therefore, multiple systemic and locally produced signals may be received, transduced, and integrated by individual cells and then propagated by the release from these cells of further signals targeted to other members of the bone cell network. In this manner, bone cell activities may be continuously coordinated to afford concerted actions and rapid responses to physiological changes. The bone microvasculature may play a pivotal role in these processes, both in linking circulatory and local signals with cells of the bone microenvironment and in actively contributing itself to the regulation of bone cell physiology. Thus, skeletal homeostasis and the coupling observed between bone resorption and bone formation during normal bone remodeling may be manifestations of this dynamic interactive communication network, operating via diverse signals not only between osteoblasts and osteoclasts but between many cell types residing within bone. © 1994 Wiley-Liss, Inc.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 157
    Digitale Medien
    Digitale Medien
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 55 (1994), S. 350-357 
    ISSN: 0730-2312
    Schlagwort(e): TGFβ ; bone formation ; mineralization ; osteoblasts ; osteoclasts ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: At first reading the statement “TGFβ stimulates bone formation but inhibits mineralization” may appear to be an oxymoron. However, the bone formation process can take weeks to months to complete, and the unique properties of TGFβ allow this factor to be stored in bone matrix in a latent form, ready to be activated and inactivated at key, pivotal stages in this long process. TGFβ may act to trigger the cascade of events that ultimately leads to new bone formation. However, once this process is initiated, TGFβ must then be inactivated or removed because if present in the later stages of bone formation, mineralization will be inhibited. The unique properties of TGFβ and its role in bone remodeling are the subject of this review. © 1994 Wiley-Liss, Inc.
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 158
    Digitale Medien
    Digitale Medien
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 55 (1994), S. 366-372 
    ISSN: 0730-2312
    Schlagwort(e): osteoclast ; gene regulation ; rat ; skeleton ; osteopontin ; osteocalcin ; mineralization ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: Osteopetrosis is a skeletal condition in which a generalized radioopacity of bone is caused by reduced resorption of bone by osteoclasts. However, it has recently been shown that during skeletal development in several osteopetrotic rat mutations specific aberrations occur in gene expression reflecting the activity of the bone forming cells, osteoblasts, and the development of tissue organization. To evaluate their pathogenetic significance, progressive osteoblast differentiation was studied in vitro. Primary cultures of normal osteoblasts undergo a sequential expression a cell growth and tissue-related genes associated with development of skeletal tissue. We report that osteoblast cultures can be established from one of these mutants, toothless; that these cells in vitro exhibit similar aberrations in gene expression during cell proliferation and extracellular matrix formation and mineralization observed in vivo; and that an accelerated maturation sequence by mutant osteoblasts mimics the characteristic skeletal sclerosis of this disease. These data are the first direct evidence for an intrinsic osteoblast defect in osteopetrosis and establish an in vitro model for the study of heritable skeletal disorders. © 1994 Wiley-Liss, Inc.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 159
    Digitale Medien
    Digitale Medien
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 55 (1994), S. 419-434 
    ISSN: 0730-2312
    Schlagwort(e): urokinase-type plasminogen activator ; plasminogen activator inhibitor-1 ; angiostatic steroids ; heparin ; suramin ; interferon alpha-2a ; retinoic acid ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: A tightly controlled increase in extracellular proteolysis, restricted both in time and space, is an important component of the angiogenic process, while anti-proteolysis is effective in inhibiting angiogenesis. By focussing on the plasminogen activator (PA)-plasmin system, the objective of the present studies was to assess whether previously described inhibitors of angiogenesis modify bovine microvascular endothelial cell proteolytic properties. We demonstrate that although synthetic angiostatic steroids (U-24067 and U-42129), heparin, suramin, interferon alpha-2a, and retinoic acid are all inhibitors of in vitro angiogenesis, each of these agents has distinct effects on the plasminogen-dependent proteolytic system. Specifically, angiostatic steroids and interferon alpha-2a reduce urokinase-type PA (u-PA) and PA inhibitor-1 activity, while heparin and retinoic acid increase u-PA activity. Suramin reduces cell-associated u-PA activity and greatly increases PAI-1 production at doses which induce monolayer disruption. These findings demonstrate that a spectrum of alterations in extracellular proteolysis is associated with anti-angiogenesis, and that anti-angiogenesis and anti-proteolysis are not necessarily correlated. A reduction in extracellular proteolysis would be expected to reduce invasion, whereas an increase in proteolysis might modulate the activity of inhibitory cytokines, which in turn could reduce endothelial cell proliferation and migration and inhibit angiogenesis. The spectrum of effects on different elements of the PA system observed in response to the agents assessed suggests that the role of modulations in extracellular proteolytic activity in anti-angiogenesis is likely to be varied and complex. © 1994 Wiley-Liss, Inc.
    Zusätzliches Material: 10 Ill.
    Materialart: Digitale Medien
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  • 160
    Digitale Medien
    Digitale Medien
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 55 (1994), S. 29-38 
    ISSN: 0730-2312
    Schlagwort(e): diabetes ; hyperinsulinemia ; insulin resistance ; lipogenesis ; fat metabolism ; amylin ; hepatic triglyceride synthesis ; muscle fat accumulation ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: Despite intensive investigation, a clear understanding of the metabolic disturbances in diabetes mellitus and their temporal relationship to each other during disease development has still not emerged. With emphasis on non-insulin-dependent diabetes (NIDDM), three possibilities are explored here: (1) that the insulin resistance characteristic of obesity/NIDDM syndromes is the result rather than the cause of hyperinsulinemia, as is widely held, (2) that the linkage between hyperactivity of the pancreatic β-cell and peripheral insulin resistance is vested in excessive delivery of lipid substrate from liver to the muscle bed, and (3) that conceivably hyperamylinemia works in concert with hyperinsulinemia in promoting overproduction of very-low-density lipoproteins by the liver, and thus in the etiology of muscle insulin resistance. © 1994 Wiley-Liss, Inc.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 161
    ISSN: 0730-2312
    Schlagwort(e): CALC gene family ; genomic organization ; transcription regulation ; biosynthesis ; islet β-cell ; insulin resistance ; islet amyloid ; type 2 diabetes mellitus ; animal model ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: Islet amyloid polypeptide (“amylin”) is the major protein component of amyloid deposits in pancreatic islets of type 2 (non-insulin-dependent) diabetic patients. Islet amyloid polypeptide consists of 37 amino acids, is co-produced and co-secreted with insulin from islet β-cells, can act as a hormone in regulation of carbohydrate metabolism, and is implicated in the pathogenesis of islet amyloid formation and of type 2 diabetes mellitus. Rat islet amyloid polypeptide differs from human islet amyloid polypeptide particularly in the region of amino acids 25-28, which is important for amyloid fibril formation. In rat and mouse, diabetes-associated islet amyloid does not develop. To study the genetic organization and biosynthesis of islet amyloid polypeptide, we have isolated and analyzed the human and rat islet amyloid polypeptide gene and corresponding cDNAs. Both genes contain 3 exons, encoding precursor proteins of 89 amino acids and 93 amino acids, respectively. Apart from a putative signal sequence, these precursors contain amino- and carboxy-terminal flanking peptides in addition to the mature islet amyloid polypeptide. To understand regulation of islet amyloid polypeptide gene expression, we have identified several potential cis-acting transcriptional control elements that influence β-cell-specific islet amyloid polypeptide gene expression. Using antisera raised against synthetic human islet amyloid polypeptide we developed a specific and sensitive radioimmunoassay to measure levels of islet amyloid polypeptide in plasma and tissue extracts. Also antisera raised against the flanking peptides will be used in studying human islet amyloid polypeptide biosynthesis. Elevated plasma islet amyloid polypeptide levels have been demonstrated in some diabetic, glucose-intolerant, and obese individuals, as well as in rodent models of diabetes and obesity. To examine the potential role of islet amyloid polypeptide overproduction in the pathogenesis of islet amyloid formation and type 2 diabetes, we generated transgenic mice that overproduce either the amyloidogenic human islet amyloid polypeptide or the nonamyloidogenic rat islet amyloid polypeptide in their islet β-cells. Despite moderately to highly (up to 15-fold) elevated plasma islet amyloid polypeptide levels, no marked hyperglycemia, hyperinsulinemia or obesity was observed. This suggests that chronic overproduction of islet amyloid polypeptide “per se” does not cause insulin resistance. No islet amyloid deposits were detected in mice up to 63 weeks of age, but in every mouse producing human islet amyloid polypeptide (as in man), accumulation of islet amyloid polypeptide was observed in β-cell lysosomal bodies. This may represent an initial phase in intracellular amyloid fibril formation. The human islet amyloid polypeptide overproducing transgenic mice model offers a unique opportunity to study the biosynthesis, intracellular handling, secretion, and extracellular handling of human islet amyloid polypeptide in vivo. © 1994 Wiley-Liss, Inc.
    Zusätzliches Material: 7 Ill.
    Materialart: Digitale Medien
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  • 162
    Digitale Medien
    Digitale Medien
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 56 (1994), S. 23-28 
    ISSN: 0730-2312
    Schlagwort(e): cancer ; metastasis ; microenvironment ; clonal selection ; tissue specificity ; tumor models ; chemosensitivity ; nude mice ; nude rats ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: The development and biological characteristics of tumor metastasis are influenced by multiple cell and host-associated factors. To study these factors experimentally, the necessity of choosing adequate in vivo model systems for human tu mor metastasisis emphasized. Recent research has provided results that highlight the role of the microenvironment in determining important characteristics of the metastatic cells, including their degree of differentitation and sensitivity to drugs. Furthermore, evidence is presented as background for discussing the general validity of the notion of clonal selection of metastatic, and whether the metastatic phenotype is acquired through the last of a series of mutational events occurring during tumor progression.
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 163
    Digitale Medien
    Digitale Medien
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 56 (1994), S. 37-47 
    ISSN: 0730-2312
    Schlagwort(e): tumor progression ; oncogenes ; multicellular tumor spheroids ; drug resistance ; metastasis ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: Evidence is reviewed which suggests a linkage may exist between certain forms of de novo or acquired drug resistance and metastasis. This includes finding that expression of certain dominantly acting mutant oncogenes or tumor suppressor genes, e.g. genes which normally act to “drive” tumor progression and metastasis, can also affect the expression of drug resistance. Moreover, this can be accompanied by altered expression of certain cellular genes thought to be involved in expression of drug resistance. A direct linkage between acquired drug resistance and metastasis would suggest that tumor sublines selected for drug resistance should manifest more aggressive malignant properties than their drug-sensitive counterparts. While this does not appear to be true for drug resistant sublines selected in vitro, indeed such cell lines frequently manifest diminished in vivo tumorigenic and/or metastatic competence, there is some evidence to support such a correlation exists for tumor cell lines that are selected in vivo for drug resistance. Attention is also drawn to the fact that new linkages between metastasis and drug resistance may be uncovered by analyzing the ability of tumor subpopulations to acquire drug resistance after one or several previous exposures to chemotherapeutic drugs, as opposed to examining intrinsic drug resistance only. Furthermore, ability to detect induced or acquired drug resistance in vitro may be strongly influenced by the types of assay used to detect and monitor drug resistanc. In particular, three-dimensional cell culture systems may reveal acquired or induced “multicellular” drug resistance in situations where conventional two-dimensional culture systems may therefore reveal as yet undiscovered associations between the phenotypes of metastasis and drug resistance.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
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  • 164
    ISSN: 0730-2312
    Schlagwort(e): mouse sarcoma 180 cells ; tissue inhibitor of metalloproteinases ; angiogenesis ; endothelial cells ; metalloproteinases ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: We have previously shown that mouse sarcoma 180 cells produce vascular endothelial growth factor [VGEF; Rosenthal et al., 1990, Growth Factors, 4: 53-59], endothelial mitogen that stimulates angiogeneis. Recent reports have implicated metallaproteinases and their inhibitors in the regulation of vascular morphogeneis, tumor invasion, and metastasis. We report here that mouse sarcoma 180 cells produce two collagenase inhibitors. These inhibitors were purified by heparin-Sepharose affinity chromatography, gel filtration, and C4 reverse phase h.p.l.c. Analytical gel electrophoresis of the purified inhibitors (MS-22 and MS-31) revealed molecular masses of 22,000 and 32,000 Da under reducing conditions, and 20,000 and 30,000 Da under nonreducing conditions, respectively. The NH2-terminal amino acid sequence of MS-22 was identical to that of tissue inhibitor of metalloproiteinases type 2 (TIMP-2) produced by human melanoma cells (Stetler-Stevenson et al., 1989, J. Biol. Chem. 264: 17374-17378) over the first 30 amino acids. The NH2-terminal amino acid sequence of MS-31 was identical to that of murine TIMP-1 [Gewert et al., 1989 EMBO J 6:651-657]. Statistical analysis of the amino acid composition data of these two mouse sarcoma 180-derived collagenase inhibitors confirms the identificationof MS-22 as TIMP-2 and MS-31 as TIMP-1.
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
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  • 165
    ISSN: 0730-2312
    Schlagwort(e): methylation ; DNA ; chromosomes 11p and 17 p13.3 ; human breast adenocarcinoma ; human colon adenocarcinoma ; γ-globin ; Ha-ras ; parathyroid hormone ; catalase ; calcitonin ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: In breast and colon adenocarcinomas methylation patterns at CCGG sites of several loci located on the short arm of chromosome 11 were determined by Southern blot analysis. Results obtained indicate that all tumor samples (20/20) exihibit DNA methylation changes when compared to their normal counterparts. In colon tumors,i-globin gene is usually hypomethylated (9/10), whereas Ha-ras gene, which is located in the same region, retains an unmodified DNA methylation pattern. Hypomethylation of parathyroid hormone (5/10) and catalase genes (4/10) are also frequently detected in colon tumor specimens. For the catalase gene the region around exon is the only one which is affected by these changes. In breast adenocacinoma, modifications of the methylation patterns are less frequently observed. However, hypomethylation of the i-globin gene is a very common event in these tumors (8/10), and it is also detected (2/2) in lobular carcinoma in situ which is an early step in breast tumorgenesis. In addition, hypermethylation of a CpG island is also observed at the locus 17p13.3 in both colon (5/5) and breast (4/9) adenocarcinomas. In the tumoral tissues which containj a limited amount of CpG. Some of these alterations seen, therefore, to be tumor and sequence specific.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
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  • 166
    Digitale Medien
    Digitale Medien
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 56 (1994), S. 536-543 
    ISSN: 0730-2312
    Schlagwort(e): acute lung injury ; basic fibroblast growth factor ; fibronectin ; transin ; stromelysin ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: Basic fibroblast growth factor (bFGF) is a mitogenic polypeptide for a wide variety of cell types and has been immunolocalized in the rodent and human lung. We investigated the mRNA and protein expression of bFGF in hyperoxic-injured adult mouse lungs using northern blot analysis and immunohistochemistry. Mece (6-8weeks) were continuously exposed to 80% osygen up to 4 days. Levels of bFGF mRNA were increased from room air control on days 3 and 4 of hyperoxia. mRNA levels of acidic fibroblast growth factor (aFGF), fibronectin, and transin/stromelysin were also examined in this injury model. Similar to bFGF, the fibronectin and transin/stromelysin mRNA levels were increased after 3 days of hyperoxia. In contrast, the aFGF mRNA levels were gradually reduced on each day of hyperoxia. A rabbit polyclonal anti-bFGF antibody was used to determine the distribution and levels of expression in the hyperoxic-injured lungs. The room air control and day 1 hyperoxic-exposed lungs exhibited staining for bFGF in the basement membranes of the blood vessels, airways, and alveoli. Patchy but intense alveolar staining was prominent on day 4 of hyperoxia. The bFGF immunoreactivity of blood vessels and airways unaffected by the hyperoxia exposure. These results suggest that bFGF may play a role in the alveolar response to hyperoxic-induced injury by virtye of the altered mRNA levels and protein distribution in this injury model.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 167
    Digitale Medien
    Digitale Medien
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 56 (1994), S. 592-596 
    ISSN: 0730-2312
    Schlagwort(e): amoeba ; encystment ; excystment ; receptors ; pathology ; therapy ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: Acanthamoeba castellanii (Neff) is a free-living soil amoeba with close relatives that are opportunistic pathogens. Trophozoites differentiatite into cysts when deprived of nutrients; cysts convert into trophozoites, leaving the well behind, in the presence of nutrients. The data presented here, which includes immunoaffinity purification of the receptor, indicate that cell surface molecular signals also control Acanthamoeba differentiation in both directions. Monoclonal antibodies that bind specifically to a 40 kD trophozoite protein initiate the encystment of trophozoites. When bound to cysts the same monoclonal antibodies prevent excystment. Washing away the antibody allows both trophozoites and cysts to resume normal activity. One of these monoclonal antibodies inhibits pinocytosis, while another has effect on pinocytosis.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 168
    Digitale Medien
    Digitale Medien
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 56 (1994), S. v 
    ISSN: 0730-2312
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 169
    Digitale Medien
    Digitale Medien
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 56 (1994), S. 1-24 
    ISSN: 0730-2312
    Schlagwort(e): Chemoprevention ; drug development ; mechanism of action ; cancer ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: This overview of the potential mechanisms of chemopreventive activity will provide the conceptual groundwork for chemopreventive drug discovery, leading to structure-activity and mechanistic studies that identify and evaluate new agents. Possible mechanisms of chemopreventive activity with examples of promising agents include carcinogen blocking activities such as inhibition of carcinogen uptake (calcium), inhibition of formation or activation of carcinogen (arylalkyl isothiocyanates, DHEA, NSAIDs, polyphenols), deactivation or detoxification of carcinogen (oltipraz, other GSH-enhancing agents), preventing carcinogen binding to DNA (oltipraz, polyphenols), and enhancing the level or fidelity of DNA repair (NAC, protease inhibitors). Chemopreventive antioxidant activities include scavenging reactive electrophiles (GSH-enhancing agents), scavenging oxygen radicals (polyphenols, vitamin E), and inhibiting arachidonic acid metabolism (glycyrrhetinic acid, NAC, NSAIDs, polyphenols, tamoxifen). Antiproliferation/antiprogression activities include modulation of signal transduction (glycyrrhetinic acid, NSAIDs, polyphenols, retinoids, tamoxifen), modulation of hormonal and growth factor activity (NSAIDs, retinoids, tamoxifen), inhibition of aberrant oncogene activity (genistein, NSAIDs, monoterpenes), inhibition of polyamine metabolism (DFMO, retinoids, tamoxifen), induction of terminal differentiation (calcium, retinoids, vitamin D3), restoration of immune response (NSAIDs, selenium, vitamin E), enhancing intercellular communication (carotenoids, retinoids), restoration of tumor suppressor function, induction of programmed cell death (apoptosis) (butyric acid, genistein, retinoids, tamoxifen), correction of DNA methylation imbalances (folic acid), inhibition of angiogenesis (genistein, retionoids, tamoxifen), inhibition of basement membrane degradation (protease inhibitors), and activation of antimetastasis genes.A systematic drug development program for chemopreventive agents is only possible with continuing research into mechanisms of action and thoughtful application of the mechanisms to new drug design and discovery. One approach is to construct pharmacological activity profiles for promising agents. These profiles are compared among the promising agents and with untested compounds to identify similarities. Classical structure-activity studies are used to find optimal agents (high efficacy with low toxicity) based on good lead agents. Studies evaluating tissue-specific and pharmacokinetic parameters are very important. A final approach is design of mechanism-based assays and identification of mechanism-based intermediate biomarkers for evaluation of chemopreventive efficacy. 1994 Wiley-Liss, Inc.This article is a US Government work and, as such, is in the public domain in the United States of America.
    Zusätzliches Material: 1 Tab.
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  • 170
    Digitale Medien
    Digitale Medien
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 56 (1994), S. 188-191 
    ISSN: 0730-2312
    Schlagwort(e): tissue regeneration ; extracelluler matrix alalougs ; organ regeneratiol ; collagen ; glycoaminoglycans ; pegeneration templates ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: The loss of tissue mass in human has been conventionally treated as an irreversible change. Treatments have emaphesized repalcement of the missing function by use of a transparent, an autograft, tissue synthesize in vitro or, mst commanly, by use of engineering deviced based on biomaterials. During the last few years solid progress has been made in the area of tissue and organ regeneratioin. This new approach is based on the discovery that certain simple chemiaal analouges of extraculler matpices synthesized by graft copolymerization of a glycosaminoglycan onto type 1 collagen can induced sylthesis of physiologic tissue in lesion which otherwise heal spontaneousely by synthesis of scar host tissue. However, regration in the adult mammal has been sucessfully demonstrated so far only in skin (human, guinea pig), scitic nerve(rat) and the inee menisaus (dog).
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 171
    Digitale Medien
    Digitale Medien
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 56 (1994), S. 192-195 
    ISSN: 0730-2312
    Schlagwort(e): bmne ; cartilage ; BMPs ; PDGF ; TGF-β ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: The three ingredients for the successful tissue engineeping of bone and cartilage are ragulatory signals, cells and extracellular matrix. Recent advance in cellular and molecular biology of thde growth and differentiation factors have set the stage for a symbiosis of biotechnology and biomaterials. Recent advances permit one to enunciate the rules of architechure for tissue engineering of bone and cartilage. The purification and cloning of bone morphogenetic proteins (BMPs) and growth factors such as platelet derived growth factors (PDGF), tranforming growth factor-β (TGF-β), and insulin-like growth factors (IGF-I) Will allow the design of an optimal combinatiol of signals to initiate and promote development of skeletal stem cells into cartilage and bone. Successful and optimal bone and motion. BMPs function as inductive signals. Biomaterials (Both natural and synthetic) mimic the extracellular matrix and play a role in conduction of bone and cartiage. Examples of biomaterials include hydroxyapatite, polyanhydrides, polyphosphoesters, polylactic acid, and polyglycolic acid. The prospects for novel biomaterials are immense, and they likely will be a fertile erowth industpy. Cooperative ventures between academia and industry and teahnology transfer from the federal government augur well for an exciting future fop clinical applications.
    Zusätzliches Material: 1 Tab.
    Materialart: Digitale Medien
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  • 172
    Digitale Medien
    Digitale Medien
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 56 (1994), S. 159-204 
    ISSN: 0730-2312
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 173
    Digitale Medien
    Digitale Medien
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 56 (1994) 
    ISSN: 0730-2312
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 174
    ISSN: 0730-2312
    Schlagwort(e): cell proliferation ; FUS3 ; KSS1 ; KFR1 ; MAP kinase ; trypanosome ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: Using degenerate oligonucleotide primers derived from conserved regions in the catalytic domains of protein kinases, we have identified transcripts of the protein kinase families in Trypanosoma brucei by the polymerase chain reaction technique. From the cDNAs synthesized from poly(A)+ RNA purified from the bloodstream form of the pathogen, we have obtained seven distinct partial cDNA sequences. Deduced amino acid sequences of these seven clones contain conserved regions characteristic of catalytic domains of eukaryotic protein serine/threonine kinases, DNA gel blots showed that one of the clones, TbPK-A4 is most likely a member of a subfamily in the protein kinase gene family, whereas the other six are probably each encoded by a single gene in the genome of T. brucei. The full-length cDNA of TbPK-A1 was cloned, sequenced, and found to encode an open reading frame of 350 amino acid residues. Its gene (designated KFR1) demonstrated high sequence similarity to KSS1 and FUS3 from Saccharomyces cerevisiae and rat MAP kinase at the amino acid level. There are a 3- to 4-fold higher level of KFR1 transcript and a 2-fold increase of KFR1 protein in the bloodstream form when compared with the insect form of T. brucei. This preferential expression of KFR1 in the bloodstream form of T. brucei may play a role in controlling the cell cycle and thus the growth rate of the organism.
    Zusätzliches Material: 7 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 175
    ISSN: 0730-2312
    Schlagwort(e): VEGF ; PIGF ; KDR ; flt ; endothelial cells ; placenta ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: Vascular endothelial growth factor (VEGF) is a newly identified growth and permeability factor with a unique specificity for endothelial cells. Recently the flt-encoded tyrosine kinase was characterized as a receptor for VEGF. A novel tyrosine kinase receptor encoded by the KDR gene was also found to bind VEGF with high affinity when expressed in CMT-3 cells. Screening for flt and KDR expression in a variety of species and tissue-derived endothelial cells demonstrates that flt is predominantly expressed in human placenta and human vascular endothelial cells. Placenta growth factor (PIGF), a growth factor significantly related to VEGF, is coexpressed with flt in placenta and human vascular endothelial cells. KDR is more widely distributed and expressed in all vessel-derived endothelial cells. These data demonstrate that cultured human endothelial cells isolated from different tissues express both VEGF receptors in relative high levels and, additionally, that all investigated nonhuman endothelial cells in culture are also positive for KDR gene expression.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 176
    Digitale Medien
    Digitale Medien
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 54 (1994), S. 100-109 
    ISSN: 0730-2312
    Schlagwort(e): heat-shock genes ; HSC70 ; vimentin ; protein phosphorylation ; intermediate filaments ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: Characteristic changes in vimentin were studied in 9L rat brain tumor cells treated at 45°C. During heat-shock treatment, vimentin molecules were rapidly phosphorylated and reorganized from a filamentous form into a perinuclear higher-order structure that was less extractable by nonionic detergent. These effects were found to be highly transient, peaked at 30 min after the onset of heat-shock treatment, and subsided thereafter. Simultaneously, the solubility of the constitutively expressed heat-shock protein70 (HSC70) was also temporarily decreased and the kinetics was identical to that of vimentin. The results indicated that HSC70 and vimentin were co-insolubilized during the heat-shock treatment. We propose that the reorganization of the intermediate filaments resulted from enhanced phosphorylation of vimentin leads to the concurrent association of HSC70 to the intermediate filaments. This process may play an essential role in regulating heat-shock genes.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 177
    ISSN: 0730-2312
    Schlagwort(e): ETR101 ; Jurkat cells ; transcriptional regulation ; chromosome localization ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: Human T cells require two discrete signals to initiate their proliferation. In Jurkat T cells the first signal can be provided by the phorbol ester TPA and the second by the calcium ionophore A23187. We have isolated a cDNA from Jurkat T cells representing mRNA induced by TPA but inhibited by simultaneous treatment of the cells with antibody, lectin, or A23187. Sequencing revealed identity of the Jurkat clone to a cDNA, termed ETR101, recently isolated from HL60 promyelocytic leukaemia cells and shown to be an immediate early gene expressed upon TPA stimulation of these cells [Shimizu et al.: J Biol Chem 266:12157, 1991]. The gene is also induced very rapidly upon TPA treatment of Jurkat cells and is superinduced by co-treatment with cycloheximide. The predicted amino acid sequence encoded by ETR101 has weak homology to JunB and JunD, therefore it is of some interest that these three genes share the chromosomal localization, 19p13.2. The divergent effects of TPA treatment upon cell proliferation and differentiation in different circumstances allow some speculation about a possible role for the ETR101 gene product upon cellular differentiation.
    Zusätzliches Material: 7 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 178
    Digitale Medien
    Digitale Medien
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 54 (1994), S. 174-185 
    ISSN: 0730-2312
    Schlagwort(e): antithrombin binding ; extracellular matrix ; glycosaminoglycans ; heparan sulfate proteoglycans ; anticoagulant heparan sulfates ; ligand binding assay ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: The heparan sulfate proteoglycans that bind and activate antithrombin III (aHSPGs) are synthesized by endothelial cells as well as other nonvascular cells. We determined the amounts of cell surface-associated and soluble aHSPGs generated by the rat fat pad endothelial (RFP) cell line and the fibroblast (LTA) cell line. The RFP cells exhibit higher levels of cell surface-associated aHSPGs as compared to LTA cells, whereas LTA cells release larger amounts of soluble aHSPGs as compared to RFP cells. After confluence RFP cells show an increase in both cell surface-associated and soluble aHSPGs. In contrast, postconfluent LTA cells maintain a constant level of cell surface-associated and soluble aHSPGs. These observations indicate that different cells types can preferentially accumulate aHSPGs as cell surface-associated or soluble forms which could reflect alternate biological functions.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 179
    ISSN: 0730-2312
    Schlagwort(e): spermatogenesis ; sperm nuclear protein ; DNA binding protein ; chromatin ; chromosomal protein ; regulation of gene expression ; tissue specific gene expression ; testis specific histone ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: The testis-specific histone H1t gene is known to be transcribed only in pachytene primary spermatocytes during spermatogenesis. Previous studies of the rat histone H1t gene revealed a unique promoter sequence element between the H1/GC box and the H1/CCAAT box. Proteins in crude nuclear extracts of rat testis bind specifically to this sequence element and a temporal correlation exists between the appearance of these DNA binding proteins and the onset of transcription. These discoveries led to a search for histone H1t genes in other mammalian species. The human and monkey histone H1t genes were amplified from genomic DNA using the polymerase chain reaction (PCR). The amplified genes were cloned and the genomic derived inserts were sequenced using linear PCR. Both proximal promoters contained the highly conserved H1/AC box, H1/CCAAT box, and H1/TATA box found in nongerminal H1 genes. Both promoters also contained the H1/GC box and the H1t/CCTAGG sequence element between the H1/GC box and H1/CCAAT box previously seen only in the H1t promoter. Specific amplification of the human H1t gene using template DNA samples from a NIGMS human/rodent somatic cell hybrid mapping panel has shown that the human histone H1t gene is located on chromosome 6.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 180
    Digitale Medien
    Digitale Medien
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 54 (1994) 
    ISSN: 0730-2312
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 181
    ISSN: 0730-2312
    Schlagwort(e): pre-adipocyte 3T3-L1 cells ; TGFβ1 ; collagen ; fibronectin ; insulin ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: Pre-adipocyte 3T3-L1 cells, after an appropriate induction stimulus, proceed through a defined change in morphology as differentiation progresses. Transforming growth factor β1 (TGFβ1) is able to block the morphological and biochemical changes which occur with differentiation of these cells if given within 36-40 h of induction [Ignotz and Massague (1985): Proc Natl Acad Sci USA 82:8530-8534]. To begin to elucidate the role of the extracellular matrix in adipogenesis, as well as the mechanism whereby TGFβ1 inhibits differentiation, we examined the expression of two extracellular matrix genes, type I (α1) procollagen and fibronectin, as well as endogenous TGFβ1. Confluent cells were induced to differentiate by treatment with insulin, dexamethasone, and isobutylmethylxanthine in the presence or absence of TGFβ1. Following 6 days of treatment, the cells in the differentiated group acquired the rounded shape of mature adipocytes; the cytosol of these cells also contained numerous lipid-filled vesicles, as demonstrated by oil red O staining. Cells treated with the differentiation compounds in the presence of TGFβ1 maintained the fibroblast-like appearance of control cells and did not stain with oil red O. At the level of gene expression, both procollagen and fibronectin mRNAs were down-regulated during differentiation of 3T3-L1 cells. When cells from the control or differentiation groups were treated with TGFβ1, there was a 2-5-fold induction of procollagen and fibronectin mRNAs throughout the 6-day time course. No change in type I procollagen transcription was observed by nuclear run-on analysis, suggesting that the increase in procollagen mRNA with TGFβ1 treatment was due to a post-transcriptional process(es). However, both transcriptional and post-transcriptional components were observed in the regulation of fibronectin gene expression by TGFβ1. In addition, TGFβ1 was found to positively regulate its own expression, as treatment of the cells with TGFβ1 enhanced endogenous TGFβ1 expression and prevented the small decrease in TGFβ1 mRNA levels which occurred early during the differentiation program. Thus, our data demonstrate that down-regulation of type I procollagen, fibronectin, and TGFβ1 gene expression was prevented during TGFβ inhibition of 3T3-L1 differentiation. Taken together, these data suggest that TGFβ may inhibit differentiation of 3T3-L1 cells by maintaining the fibroblast-like extracellular matrix, thus preventing the changes in cell shape that accompany differentiation.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 182
    ISSN: 0730-2312
    Schlagwort(e): diabetes ; G proteins ; insulin ; obesity ; insulin receptors ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: A novel pathway for physiological “cross-talk” between the insulin receptor and the regulatory Gi-protein has been demonstrated. We tested the hypothesis that a coupling defect between Gi and the insulin receptor is present in the liver of obese patients with and without type li diabetes. Insulin 1 × 10-9 M (∼ ED50) and 1 × 10-7 M (Max) inhibited pertussis toxin-catalyzed ADP ribosylation of Gi in human liver plasma membranes from lean and obese nondiabetic patients. However, 1 × 10-7 M insulin was without effect in membranes from patients with type II diabetes. This coupling defect was not intrinsic to Gi, since Mg2+ and GTPγS inhibited pertussis toxin-catalyzed ADP ribosylation in both diabetic and nondiabetic patients. Binding of insulin of the α-subunit and activation of the tyrosine kinase intrinsic to the β-subunit of the insulin receptor are not responsible for the coupling defect. 125I insulin binding is the same in obese patients with or without diabetes. Tyrosine kinase of the insulin receptor is decreased in diabetes. However, a monoclonal antibody to the insulin receptor (MA-20) at equimolar concentrations with insulin equally inhibits pertussis toxin-catalyzed ADP ribosylation of Gi without activating tyrosine kinase or insulin receptor autophosphorylation. Immunodetection of G-proteins suggested that Gi3α was normal in diabetes and Gi1-2α was decreased by 40% in the diabetic group as compared to the obese nondiabetic group but was normal when compared to the lean non diabetic group. We conclude that the novel pathway of insulin signaling involving the regulatory Gi proteins via biochemical mechanisms not directly involving the tyrosine kinase of the insulin receptor is altered in obese type II diabetes and offers a new target for the search of the mechanism(s) of insulin resistance.
    Zusätzliches Material: 10 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 183
    ISSN: 0730-2312
    Schlagwort(e): rat bone transcription ; rat bone transcription factors ; osteopetrotic bone transcription ; osteocalcin transcription ; collagen transcription ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: Transcriptional regulation of gene expression in vivo in bone, associated with normal development or skeletal disorders, to date, has not been studied. We report the successful isolation of nuclei that are transcriptionally active from normal and osteopetrotic rat bone. Transcription rates of cell growth and bone-related genes (including histone H4, c-fos, c-jun, TGFβ1, β2 macroglobulin, collagen, fibronectin, osteocalcin, osteopontin, and tartrate resistent acid phosphatase) change as a function of calvarial development from birth to 6 weeks and are selectively modified in osteopetrotic animals. Additionally, nuclei isolated from intact bone yield promoter binding factors. Bone nuclei, which transcribe faithfully and contain the normal complement of nuclear protein factors, offer a powerful approach for investigating in vivo gene regulation in skeletal development and pathology. © 1994 Wiley-Liss, Inc.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 184
    ISSN: 0730-2312
    Schlagwort(e): drug-induced DNA damage ; cis-DDP ; malignant oligodendroglioma ; CAT ; eukaryotic expression vector ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: Current evidence suggest an important role for increased repair of drug-induced DNA damage as one of the major mechanisms involved in tumor cell resistance to cis-DDP. In this study, we examined the DNA repair capacity and the activities of three DNA repair related proteins, namely, DNA polymerases α and β, and total DNA ligase in cells of a malignant oligodendroglioma obtained from a patient before therapy and compared it with those of a specimen of the tumor acquired after the patient had failed cis-DDP therapy. DNA repair capacity was quantitated as the extent of reactivation of the chloramphenicol-O-acetyltransferase (CAT) gene in a eukaryotic expression vector that has been damaged and inactivated by prior treatment with cis-DDP and then transfected into the tumor cells. The extent of DNA-platinum adduct formation in the expression vector was determined by flameless atomic absorption spectrometry. The level of cis-DDP resistance of cells of the two tumors was determined with the capillary tumor stem cell assay. We observed a 2.8-fold increased capacity to repair Pt-DNA adducts and reactivate the CAT gene in cells of the tumor obtained after cis-DDP therapy, compared to cells of the untreated tumor. This was associated with increases of 9.4-fold and a 2.3-fold, respectively, in DNA polymerase β and total DNA ligase activities in cells of the treated tumor. At 5 μM cis-DDP, there was a 5.9-fold increase in the in vitro cis-DDP resistance of post-therapy tumor cells relative to cells of the untreated tumor. No significant difference in DNA polymerase α activity was observed between the two tumors. These data suggest that the enhanced ability to repair cis-DDP induced DNA damage, mediated, in part, by increased tumor DNA polymerase β and DNA ligase activities, plays an important role in the in vivo acquisition of cis-DDP resistance in human malignant gliomas, and that these proteins and/or their encoding genes may represent critical targets for strategies to overcome such resistance clinically.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
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  • 185
    Digitale Medien
    Digitale Medien
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 54 (1994), S. 67-77 
    ISSN: 0730-2312
    Schlagwort(e): tissue transglutaminase ; apoptosis ; hepatoma ; dexamethasone ; retinoic acid ; transforming growth factors ; cell growth ; cell death ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: Close correlation between tissue transglutaminase (tTG) induction and growth regulation and/or cell death processes has been suggested in many cell lineages. In this study, the regulation of the tTG levels by various growth and differentiation factors and its relation to growth rate and cell death processes were investigated in two rat hepatoma cell lines, McA-RH7777 and McA-RH8994, using a monoclonal antibody against liver tTG. Transforming growth factor-β1 (TGF-β1) and retinoic acid (RA) each increased tTG to the level of 8- to 32-fold above that of control cultures in both cell lines after 72-h treatment. Dexamethasone (DEX) induced a 16- to 32-fold of tTG in McA-RH8994 cells while it did not change the enzyme level in McA-RH7777 cells. Simultaneous addition of DEX and RA increased the tTG level to more than 50-fold in McA-RH7777 cells as well as McA-RH8994 cells. Other factors, such as TGF-α, hepatocyte growth factor, dimethyl sulfoxide, and protein kinase C activator, did not show significant increases of the tTG levels. Although tTG induction by TGF-β1 or DEX appeared to be correlated with their growth suppressive effects, RA increased the tTG level without suppressing the growth rate of hepatoma cells. TGF-β1 was also shown to induce cell death in both cell lines. Our results demonstrate that RA and DEX are capable of modulating the TGF-β1-induced cell death processes independent of the tTG levels. We present evidence here that tTG induction by itself is not the direct cause of growth suppression and cell death in these hepatoma cells.
    Zusätzliches Material: 7 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 186
    Digitale Medien
    Digitale Medien
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 54 (1994) 
    ISSN: 0730-2312
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 187
    Digitale Medien
    Digitale Medien
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 54 (1994), S. 154-160 
    ISSN: 0730-2312
    Schlagwort(e): DNA methylation ; gene regulation ; nuclease hypersensitivity ; chromatin ; procollagen gene ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: The higher ordered structure of the chicken α2(I) procollagen gene was analyzed in chromatin isolated from expressing (lung) and nonexpressing (reticulocyte and erythrocyte) tissues. Digestion of DNA with methylation sensitive restriction endonucleases revealed that this gene was methylated in all tissues examined and that no differences existed in the promoter methylation patterns between expressing and nonexpressing tissues. DNAse 1 hypersensitive sites were located between 100-300 bp upstream from the transcription initiation site and within the first intron. These sites were also hypersensitive to the single-strand specific S1 nuclease, implying that this region of the gene in the chromatin is either in an unfolded single-stranded conformation or under severe conformational stress. These differences in the α2(1) chromatin structure were confirmed by the finding that the promoter was more accessible to restriction endonuclease digestion in the expressing tissues than in the nonexpressing tissues. Digestion of chromatin with Pst I and Sma I revealed that some of these sites in the promoter were differentially protected by DNA-binding proteins in the two tissue types. These protected sites were located as far upstream as -1,600 and downstream within the first intron at +800.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 188
    ISSN: 0730-2312
    Schlagwort(e): granulocytes ; monocytes ; human myeloid cell lines ; retinoic acid ; phorbol ester ; mRNA ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: The human myeloid cell nuclear differentiation antigen (MNDA) is expressed constitutively in cells of the myeloid lineage, appearing in myeloblast cells in some cases of acute myeloid leukemia and consistently being detected in promyelocyte stage cells as well as in all later stage cells including peripheral blood monocytes and granulocytes. The human myeloid leukemia cell lines, HL-60, U937, and THP-1, express similar levels of immunochemically detectable MNDA. Although, the level of MNDA mRNA in primary monocytes is very low it was up-regulated at 6 h following the addition of interferon α. The effect of interferon α on the MNDA mRNA is also observed in the cell lines HL-60, U937, and THP-1. The MNDA mRNA level in primary granulocytes was unaffected by addition of interferon α and other agents including interferon γ, endotoxin, poly (I) · poly (C), and FMLP. The MNDA mRNA level in the myeloid cell lines was also unaffected by the latter four agents. Induction of differentiation in the myeloid cell lines with phorbol ester induces monocyte differentiation which was accompanied by a decrease in MNDA mRNA level. This reduced level of mRNA could then be elevated with subsequent interferon α treatment. The effects of phorbol ester on MNDA mRNA appeared to be associated with induced differentiation since inhibiting cell proliferation did not alter the level of MNDA mRNA and cell cycle variation in MNDA mRNA levels were not observed. The ability of interferon α to up-regulate MNDA mRNA in phorbol ester treated myeloid cell lines is consistent with the observations made in primary monocytes. Granulocyte differentiation induced by retinoic acid treatment of HL-60 cells did not alter the MNDA mRNA level which was also unchanged following subsequent treatment with interferon α. The lack of interferon α effects on retinoic acid treated HL-60 cells is consistent with its inability to influence MNDA mRNA level in primary granulocytes.
    Zusätzliches Material: 7 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 189
    Digitale Medien
    Digitale Medien
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 54 (1994), S. 239-246 
    ISSN: 0730-2312
    Schlagwort(e): gene expression ; microdissection ; nephron segments ; endothelial cells ; in situ hybridization ; erythropoiesis ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: Erythropoietin (Epo) is a glycoprotein secreted by kidney cells which plays an important role in the regulation of erythropoiesis. Localization of the Epo production by immunohistochemical studies and in situ hybridization has not been definitively established and is still a matter of controversy. Epo and glyceraldehyde 3-dehydrogenase (GAPDH) mRNA levels were determined in total RNA isolated from control and CoCl2-treated rats using a coupled reverse transcriptase/polymerase chain reaction method (RT/PCR). As indicated by the amount of amplification product, Epo mRNA levels were several-fold higher in CoCl2-treated rat kidney. In contrast, GAPDH mRNA levels were similar in control and CoCl2-treated rats. This RT/PCR method was also used to assess the level of Epo and GAPDH mRNA in microdissected nephron segments. All nephron segments tested lacked any detectable levels of Epo mRNA in either control or CoCl2-treated rats. On the other hand, peritubular cells (capillary fraction: afferent/efferent arteriole, vasa recta) were the only cells where the Epo mRNA was detected. Using a specific primer for GAPDH, the RT/PCR method could identify GAPDH mRNA in all microdissected nephron segments where the Epo mRNA was not expressed. Thus, a combination of microdissected nephron segments and RT/PCR enabled us to detect GAPDH mRNA populations in all nephron segments, whereas the failure to detect Epo mRNA in all segments but the capillary fraction, is due to the specific and localized expression of the Epo gene to this fraction.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 190
    Digitale Medien
    Digitale Medien
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 54 (1994), S. 281-288 
    ISSN: 0730-2312
    Schlagwort(e): c-myc promoter ; CAT expression ; low frequency electric ; EM fields ; transcription ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: The level of c-myc transcripts is increased in cells exposed to extremely low frequency (elf) electromagnetic (EM) fields at 60 Hz. The aim of the present experiments was to determine if regulatory regions upstream of the c-myc gene modulate the response to EM fields. DNA upstream of P1 of both mouse and human c-myc genes was transfected into cells as CAT constructs. The presence of DNA 5′ to the human or mouse myc genes results in increased expression of CAT following 20 min exposures of cells to 60 Hz elf EM fields. Specific portions of the human upstream DNA were deleted and introduced into cells. The region responsive to EM fields is located between -353 and -1,257 relative to the P1 promoter.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 191
    ISSN: 0730-2312
    Schlagwort(e): gene regulation ; stable transfection ; CAT assay ; sodium butyrate ; mRNA ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: A number of studies suggest that an inverse correlation exists between the epidermal growth factor-receptor and the estrogen receptor expression in primary human breast carcinoma as well as in established human breast carcinoma cell lines. Recent studies suggest that the epidermal growth factor-receptor does not regulate the estrogen receptor gene expression. Whether the estrogen receptor regulates the epidermal growth factor-receptor gene expression is not known. We addressed this question by stably transfecting the estrogen receptor cDNA into the estrogen receptor-negative human breast carcinoma cell line MDA-MB-231. Constitutive expression of functional estrogen receptors in the transfactants resulted in increased mRNA levels of both epidermal growth factor-receptor and transforming growth factor α. Estradiol treatment of transfected cells, although enhancing transforming growth factor α mRNA levels, did not modulate epidermal growth factor-receptor mRNA levels. The estrogen receptor-transfected cells grown in estrogenic regular medium, however, exhibited lower constitutive levels of epidermal growth factor-receptor mRNA than in steroid-stripped medium, suggesting that estrogens coupled with some factors normally present in the regular medium may indeed downmodulate epidermal growth factor-receptor mRNA. Sodium butyrate treatment enhanced epidermal growth factor-receptor mRNA levels in nontransfected cells grown in regular estrogenic as well as in steroid stripped medium. Sodium butyrate enhancement of epidermal growth factor-receptor mRNA levels was completely abolished in estrogen receptor-transfected cells grown in regular estrogenic medium and blunted in steroid stripped medium. Using various epidermal growth factor-receptor gene promoter-CAT constructs in transient transfection assays, we further demonstrate that sodium butyrate enhanced transcription of the epidermal growth factor-receptor gene. The putative sodium butyrate responsive element(s) appears to localize within the proximal 384 bp of the epidermal growth factor-receptor gene promoter region. Although the interactions between estrogen receptor and epidermal growth factor-receptor are rather complex, taken together, our data suggest that estrogen receptor can indeed modulate the epidermal growth factor-receptor mRNA expression.
    Zusätzliches Material: 7 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 192
    Digitale Medien
    Digitale Medien
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 54 (1994) 
    ISSN: 0730-2312
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 193
    Digitale Medien
    Digitale Medien
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 54 (1994), S. 375-378 
    ISSN: 0730-2312
    Schlagwort(e): regulation ; cell cycle ; cancer ; transcription ; translation ; protein modification ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: The objective of this brief review is to stress the importance of multiple levels of molecular regulation of complex processes such as cell growth and to illustrate their derangements as they occur in cancer cells. One major research emphasis today is the regulation of transcription by binding of transactivating proteins to promoter motifs. Another focus is on the multiple roles of protein phosphorylations in signal transduction pathways. Evidence is strong, however, that major controls exist at numerous other molecular levels as well (Fig. 1). These include pre-mRNA processing, pre-mRNA degradation, mRNA degradation, control of translation, permanent protein modifications, protein degradation, reversible covalent protein alterations, noncovalent interactions with small molecules and with other proteins, and effects of relocations into cell compartments. These controls are exhibited in all biological processes. A few illustrative examples are briefly discussed, which come mainly from our researches in the area of cell cycle regulation and its derangement in cancer.
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 194
    Digitale Medien
    Digitale Medien
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 54 (1994), S. 440-452 
    ISSN: 0730-2312
    Schlagwort(e): cell cycle ; cancer chemotherapy ; check points ; p53 ; cdc2 ; cell death ; cytoxicity ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: As detailed information accumulates about how cell cycle events are regulated, we can expect new opportunities for application to cancer therapy. The altered expression of oncogenes and tumor suppressor genes that commonly occurs in human cancers may impair the ability of the cells to respond to metabolic perturbations or stress. Impaired cell cycle regulation would make cells vulnerable to pharmacologic intervention by drug regimens tailored to the defects existing in particular tumors. Recent findings that may become applicable to therapy are reviewed, and the possible form of new therapeutic stratagems is considered.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 195
    Digitale Medien
    Digitale Medien
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 54 (1994), S. 478-486 
    ISSN: 0730-2312
    Schlagwort(e): oocyte maturation ; ras proteins ; phospholipases ; phosphatidic acid ; Xenopus laevis ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: Xenopus laevis oocytes are a powerful tool for the characterization of signal transduction pathways leading to the induction of DNA synthesis. Since activation of PLA2, PLC, or PLD has been postulated as a mediator of ras function, we have used the oocyte system to study the putative functional relationship between ras-p21 and these phospholipases. A rapid generation of PA and DAG was observed after ras-p21 microinjection, suggesting the activation of both PLC and PLD enzymes. However, production of DAG was sensitive to inhibition of the PA-hydrolase by propranolol, indicating that PLD is the enzyme responsible for the generation of both PA and DAG. Microinjection of PLD or ras-p21 induced the late production of lysophosphatidylcholine on a p42MAPK-dependent manner, an indication of the activation of a PLA2. Inhibition of this enzyme by quinacrine does not inhibit PLD- or ras-induced GVBD, suggesting that PLA2 activation is not needed for ras or PLD function. Contrary to 3T3 fibroblasts, where ras-p21 is functionally dependent for its mitogenic activity on TPA- and staurosporine-sensitive PKC isoforms, in Xenopus oocytes, induction of GVBD by ras-p21 was independent of PKC, while PLC-induced GVBD was sensitive to PKC inhibition. Thus, our results demonstrate the activation of PLD and PLA2 by ras-p21 proteins, while no effect on PLC was observed.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 196
    Digitale Medien
    Digitale Medien
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 54 (1994), S. 494-500 
    ISSN: 0730-2312
    Schlagwort(e): vitamin D ; nuclear matrix ; protein ; AP-1 ; NMP2 ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: The subnuclear distribution of the vitamin D receptor was investigated to begin addressing the contribution of nuclear architecture to vitamin D-responsive control of gene expression in ROS 17/2.8 rat osteosarcoma cells. The nuclear matrix is an anastomosing network of filaments that is functionally associated with DNA replication, transcription, and RNA processing. The representation of vitamin D receptor in the nuclear matrix and nonmatrix nuclear fractions was determined by the combined application of (1) sequence-specific interactions with the vitamin D receptor binding element of the rat bone-specific osteocalcin gene promoter and (2) Western blot analysis. Both methods confirmed the presence of vitamin D receptor in the nonmatrix nuclear fraction and the absence of detectable vitamin D receptors associated with the nuclear matrix. In contrast, these same nuclear matrix proteins preparations exhibited association with the general transcription factor AP-1 and a bone tissue-specific promoter binding factor NMP2. NMP-2 exhibits recognition for a promoter domain contiguous to the vitamin D-responsive element of the osteocalcin gene, although the vitamin D receptor does not appear to be a component of the nuclear matrix proteins. Interrelationships between nuclear matrix proteins and nonmatrix nuclear proteins, in mediating steroid hormone responsiveness of a vitamin D-regulated promoter, are therefore suggested.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 197
    Digitale Medien
    Digitale Medien
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 55 (1994), S. 32-58 
    ISSN: 0730-2312
    Schlagwort(e): pore complex ; transporter proteins ; transcription factors ; nuclear localization ; nuclear proteins ; basic region ; cytoplasmic proteins ; membrane proteins ; c-Myc ; c-Jun ; NF-κB ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: We have recognized about ten distinct forms of strongly basic hexapeptides, containing at least four arginines and lysines, characteristic of nuclear proteins among all eukaryotic species, including yeast, plants, flies and mammals. These basic hexapeptides are considered to be different versions of a core nuclear localization signal, NLS. Core NLSs are present in nearly all nuclear proteins and absent from nearly all “nonassociated” cytoplasmic proteins that have been investigated. We suggest that the few (∼ 10%) protein factors lacking a typical NLS core peptide may enter the nucleus via their strong crosscomplexation with their protein factor partners that possess a core NLS. Those cytoplasmic proteins found to possess a NLS-like peptide are either tightly associated with cell membrane proteins or are integral components of large cytoplasmic protein complexes. On the other hand, some versions of core NLSs are found in many cell membrane proteins and secreted proteins. It is hypothesized that in these cases the N-terminal hydrophobic signal peptide of extracellular proteins and the internal hydrophobic domains of transmembrane proteins are stronger determinants for their subcellular localization. The position of core NLSs among homologous nuclear proteins may or may not be conserved; however, if lost from an homolgous site it appears elsewhere in the protein.This search provides a set of rules to our understanding of the nature of core nuclear localization signals: (1) Core NLS are proposed to consist most frequently of an hexapeptide with 4 arginines and lysines; (2) aspartic and glutamic acid residues as well as bulky amino acids (F, Y, W) need not to be present in this hexapeptide; (3) acidic residues and proline or glycine that break the α-helix are frequently in the flanking region of this hexapeptide stretch; (4) hydrophobic residues ought not to be present in the core NLS flanking region allowing for the NLS to be exposed on the protein. In this study we attempt to classify putative core NLS from a wealth of nuclear protein transcription factors from diverse species into several categories, and we propose additional core NLS structures yet to be experimentally verified. © 1994 Wiley-Liss, Inc.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 198
    Digitale Medien
    Digitale Medien
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 55 (1994), S. 83-92 
    ISSN: 0730-2312
    Schlagwort(e): chromatin structure ; preset/remodeling ; gene repression/activation ; nucleosome positioning ; repressors ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: Recent genetic and biochemical studies have revealed critical information concerning the role of nucleosomes in eukaryotic gene regulation. Nucleosomes package DNA into a dynamic chromatin structure, and by assuming defined positions in chromatin, influence gene regulation. Nucleosomes can serve as repressors, presumably by blocking access to regulatory elements; consequently, the positions of nucleosomes relative to the location of cis-acting elements are critical. Some genes have a chromatin structure that is “preset,” ready for activation, while others require “remodeling” for activation. Nucleosome positioning may be determined by multiple factors, including histone-DNA interactions, boundaries defined by DNA structure or protein binding, and higher-order chromatin structure. © 1994 Wiley-Liss, Inc.
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 199
    Digitale Medien
    Digitale Medien
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 55 (1994) 
    ISSN: 0730-2312
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 200
    Digitale Medien
    Digitale Medien
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 55 (1994), S. 168-172 
    ISSN: 0730-2312
    Schlagwort(e): Ca2+-ATPase ; phorbol ester ; Ca2+ transport ; nuclear signaling ; rat liver nuclei ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: The effect of phorbol 12-myristate 13-acetate (PMA) on Ca2+-ATPase activity in rat liver nuclei was investigated. Ca2+-ATPase activity was calculated by subtracting Mg2+-ATPase activity from (Ca2+-Mg2+)-ATPase activity. The nuclear Ca2+-ATPase activity was significantly increased by the presence of PMA (2-20 μM) in the enzyme reaction mixture; the maximum effect was seen at 10 μM. The PMA (10 μM)-increased Ca2+-ATPase activity was not blocked by the presence of staurosporine (2 μM) or dibucaine (2 and 10 μM), an inhibitor of protein kinase. Meanwhile, vanadate (20 and 100 μM) caused a significant reduction in the nuclear Ca2+-ATPase activity increased by PMA (10 μM). The present finding suggests that PMA has an activating effect on liver nuclear Ca2+-ATPase independent of protein kinase. © 1994 Wiley-Liss, Inc.
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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