ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Selective expression of mRNA encoding platelet-derived growth factor B chain following transfection of foreign genes into cell lines derived from baby hamster kidney (1989)
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 39 (1989), S. 87-94 
    Details
    ISSN: 0730-2312
    Keywords: PDGF A ; PDGF B ; BHK cells ; gene transfection ; growth selection ; foreign genes ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: The genes for platelet-derived growth factor (PDGF) A and PDGF B chains are expressed in a variety of biological situations. Active PDGF consists of two distinct but homologous polypeptide chains, PDGF A and PDGF B, which are found as heterodimers or homodimers. We report a novel situation in which there is selective expression of mRNA encoding PDGF B in cell lines derived from baby hamster kidney (BHK) following transfection with various gene/cDNA constructs and following growth selection with methotrexate. The process of transfection itself, and not expression of the proteins encoded by the transfected genes/cDNAs (hormones, enzymes, and structural proteins), induces expression of PDGF B. No PDGF B mRNA is detectable in control cell lines. Low levels of mRNA encoding PDGF A are constitutively present and are not changed by transfection and/or growth selection. PDGF-like activity is present in the medium whenever PDGF B mRNA is detected. The composition of the secreted PDGF dimer cannot be established from our data, but quantitative analysis of mRNA suggests that the PDGF is a B-B dimer. However, the data show that transcription of the PDGF A and PDGF B genes in BHK cells is regulated independently, similar to that reported for some human tumor cells. Furthermore, the selective expression of PDGF B in response to the introduction of foreign genes and to growth selection may be an important aspect of the reaction of these cells to nonoptimal growth conditions, allowing survival and growth of the cells that express PDGF B.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcb.240390110
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Physiological quiescence in plasma-derived serum: Influence of platelet-derived growth factor on cell growth in culture (1978)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 97 (1978), S. 497-508 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: A platelet-derived growth factor can be shown to be the principal stimulant of DNA synthesis in whole blood serum for those cells that require serum for maintenance and growth in culture. Cell free plasma-derived serum lacks such platelet-derived material. 3T3 cells and primate arterial smooth muscle cells can be maintained in a quiescent state in culture for as long as six weeks in plasma-derived serum. Such cells can grow logarithmically after exposure to 5% whole blood serum or as little as 100 ng/ml of partially purified platelet factor. The cell cycle of smooth muscle cells has been studied in the quiescent (5% plasma-derived serum) and growing state (5% whole blood serum or 5% plasma-derived serum plus platelet factor). The generation time of smooth muscle cells is 16 to 18 hours as shown by autoradiographic frequency of labelled mitoses. The generation time is the same for cells in the growth fraction in either 5% whole blood serum or 5% plasma-derived serum. Thus, platelet factor acts by recruiting cells into the growth fraction rather than effecting a change in the duration of the cell cycle. Flow microfluorimetry studies on cells growing logarithmically in 5% whole blood serum give the following phase durations:G1 = 5.6 hours; S = 7.6 hours; and G2 + M = 3.8 hours.Based on these studies the argument is presented that cells cultured in 5% plasma-derived serum provide a more physiological base for the study of quiescence than do cells in low concentrations of whole blood serum or confluent, density inhibited cells at high (5% or greater) concentrations of whole blood serum. Furthermore, 5% plasma-derived serum represents an appropriate state to examine the perturbation of quiescent cells.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1040970325
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Analysis of the mitogenic effect of fetuin preparations on arterial smooth muscle cells: The role of contaminant platelet-derived growth factor (1985)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 125 (1985), S. 357-366 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Fetuin, a major protein of fetal calf serum, partially purified by the method of Pedersen, stimulated growth of aortic smooth muscle cells. More highly purified fetuin preparations stimulated growth less than Pedersen fetuin, as previously described for other cell types, suggesting that this activity is due to a contaminant. Recently bovine alpha2-macroglobulin or “Embryonin” has been proposed as the mitogenic component of crude fetuin preparations. We found that active fetuin preparations did contain alpha2-macroglobulin that stimulated smooth muscle cell growth. However, alpha2-macroglobulin purified directly from platelet-poor bovine plasma or fetuin purified from Pedersen fetuin by gel filtration lacked appreciable mitogenic effect on smooth muscle cells. Since alpha2-macroglobulin can bind platelet-derived growth factor (PDGF), and since highly acidic fetuin might bind the very basic PDGF molecule non-specifically, we measured the PDGF content of various fetuin preparations and found a good correlation between the PDGF content and mitogenic activity. Gel filtration experiments demonstrated that in Pedersen fetuin PDGF occurred both free, and in association with alpha2-macroglobulin. We conclude that the principal mitogenic component for smooth muscle cells in crude fetuin preparations is PDGF, since purified bovine alpha2-macroglobulin or fetuin do not appreciably affect growth of these cells. These results help to resolve a long-standing controversy regarding the nutrition of cultured cells. In addition, we suggest that before alpha2-macroglobulin or “Embryonin” is accepted as a bona fide growth factor for a given cell type, the role of contamination with PDGF should be assessed.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041250302
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Multiple growth factors are associated with lesions of atherosclerosis: Specificity or redundancy? (1996)
    New York, NY : Wiley-Blackwell
    BioEssays 18 (1996), S. 271-282 
    Details
    ISSN: 0265-9247
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Within the last five years, a number of specific growth factors have been localized in developing lesions of atherosclerosis. This localization of growth factors that is not observed in normal vessels, together with the pleotrophic activities of growth factors, have suggested a role for growth factors in atherosclerotic lesion progression. However, based on in vitro studies, many of the growth factors identified in lesions have overlapping target cells and are derived from the same cellular sources. What is the relative role of the specific growth factors identified? How is the their activity altered by the local conditions in the vessel wall? How do different risk factors for atherosclerosis alter the balance between growth factors and their natural regulators? Evidence for the involvement of specific growth factors in the progression of lesions of atherosclerosis is discussed, as well as the multiple levels at which the activities of these growth factors may be regulated by the vessel wall.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bies.950180405
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...