Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Proceed order?

Export
  • 1
    Book
    Book
    Boca Raton, Fla. : : CRC Press,
    Call number: 04-Med:039a ; 04-Med:039b
    Type of Medium: Book
    Pages: 2 v. 〈1 〉 : 172 p., v. 2: 213 p. , ill. ; , 26 cm.
    ISBN: 0849365260 (v. 1) , 0849365279 (v. 2)
    Language: English
    Location: Abt
    Location: Abt
    Signatur Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1432-119X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Zusammenfassung In der Arbeit wird die Anwendung flüssiger Emulsionen in Gel-Form bei der Herstellung von Autoradiogrammen zum Nachweis H3-markierter Substanzen beschrieben. Die Vor- und Nachteile von Emulsionen unterschiedlicher Empfindlichkeit und verschiedenen Silberkorndurchmessers werden besprochen. An Hand von Abbildungen kann gezeigt werden, daß mit flüssigen Emulsionen bei leichterer Anwendbarkeit und zeitsparender Technik die gleichen Ergebnisse erhalten werden können wie mit der Stripping-Film-Technik.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 1749-6632
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Natural Sciences in General
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 4
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Mouse spleen cells in diffusion chambers were studied in an effort to assess the radiation survival curves of lymphoid cells during the different serological phases of immune response and to characterize morphologically and metabolically these radiation-resistant cells. The results showed that the capacity of immunocompetent progenitor cells to proliferate and differentiate into antibody-synthesizing cells was highly sensitive to x-irradiation. Their fully differentiated progenies, which were made up mainly of mature plasma cells, were resistant in that they were able to synthesize antibody effectively for as long as several days after their exposure to radiation doses up to 10,000 R.As a result of these studies, a method with a high recovery yield was devised for obtaining a highly purified preparation of dispersed monospecific antibody-synthesizing cells. This was done by simply exposing primed spleen cells to 10,000 R at the end of the log phase of response and harvesting the culture several days later.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: We have shown in the present study and in studies reported previously that preneoplastic and neoplastic rat tracheal epithelial (RTE) cell lines express TGFα and do so regardless of the mechanism by which they were transformed. In order to determine whether TGFα is an autocrine growth regulator of immortalized RTE -cells, we have examined the function of TGFα/EGF receptors and the growth requirements for TGFα in these cells. The level of immunoprecipitated TGFα/EGF receptor protein in immortalized RTE cells was similar to or less than levels in primary RTE cells, indicating that chemically induced transformation of RTE cells does not involve overexpression of TGFα/EGF receptors. Scatchard analysis of TGFα/EGF receptors in the neoplastic EGV5T cell line revealed the presence of high-affinity (Kd = 0.4nM) and low-affinity (Kd = 9.8nM) binding sites. A tyrphostin TGFα/EGF receptor tyrosine kinase inhibitor decreased in a dose-dependent manner the proliferation as well as EGF-induced autophosphorylation of the TGFα/EGF receptor of transformed RTE cells. The inhibitory effect of tyrphostin on proliferation and receptor kinase activity was attenuated in late log and plateau phase cultures. The phosphotyrosine content of several other EGF-dependent and independent phosphoproteins was also decreased by the tyrphostin. Proliferation of transformed RTE cells was also inhibited when TGFα antisera was added to the media of growing cells. These data are consistent with the hypothesis that proliferation of transformed RTE cells involves autocrine regulation by TGFα and its receptor.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 6
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Primary rat tracheal epithelial (RTE) cell cultures have previously been shown to be highly sensitive to growth inhibition by transforming growth factor-β1 (TGF-β1) when treated within 1-2 days after plating. The purpose of the present studies was to examine the effects of TGFβ1 on the growth of RTE cells as a function of time in culture. We found that the sensitivity of RTE cells to growth inhibition by TGFβ1 decreased dramatically as the cultures aged. The IC50 for inhibition of colony forming efficiency was 0.18 pM when TGFβ1 was added 24 h after cell plating. When TGFβ1 treatment was begun on day 5 of culture, the IC50 was 3-4 pM as measured by inhibition of growth (cell number) and DNA synthesis. However, when TGFβ1 was begun on day 19, the IC50 was 65 pM or 〉 500 pM, depending on whether inhibition of growth or DNA synthesis, respectively, was measured. TGFβ1 accelerated cell death, as measured by exfoliation of cells, and inhibited cell proliferation. The decrease in responsiveness to TGFβ1 in late cultures was shown to be dependent on culture age as well as on cell density. No evidence was found for inactivation or degradation of the added TGFβ1 by the late stage cultures. Cells subcultured from late stage primary cultures remained less responsive to TGFβ1 than subcultured cells from early cultures. Similar to its effect on proliferation, TGFβ1 down-regulated the expression of two proliferation-related genes, c-myc and transforming growth factor-α, in early but not late RTE cell cultures. On the other hand, fibronectin expression was increased by TGFβ1 by about twofold at both early and late times in culture. This indicates that the changes in TGFβ1 responsiveness with time in culture are selective, apparently affecting primarily proliferation-related events. © 1992 Wiley-Liss, Inc.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 7
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: We have examined dependence of primary rat tracheal epithelial (RTE) on exogenous epidermal growth factor (EGF) and determined whether a TGFα autocrine pathway is operating in these cells. Primary RTE cells plated in serum free media (SFM) without EGF and bovine pituitary factor (BPE) show little proliferation compared to cultures propagated in media containing EGF/BPE (CSFM). Removal of EGF/BPE shortly after plating, however, results in significant proliferation, although plateau cell densities are reduced and cell morphology is significantly altered compared to cells propagated in CSFM. Addition of EGF and/or BPE to cultures propagated in SFM minus EGF/BPE restores maximum cell density. The concentration of TGFα peptide in media conditioned by cells propagated without EGF/BPE is lower than the concentration in the media of CSFM cultures. TGFα mRNA and protein levels are also significantly lower in cells late in culture compared to logarithmically growing cells regardless of the presence or absence of EGF/BPE. The proliferation of primary RTE cells propagated without EGF/BPE is inhibited by neutralizing TGFα antiserum and by a tyrphostin compound that blocks TGFα/EGF receptor tyrosine kinase activity. These results indicate that primary RTE cells utilize TGFα as an autocrine growth factor and that the autocrine pathway is regulated as a function of growth state of the cells. However, this pathway does not provide growth autonomy to primary RTE cells, since cultures remain dependent on exogenous EGF/BPE for sustained proliferation. © 1992 Wiley-Liss, Inc.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 8
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Primary rat tracheal epithelial (RTE) cell cultures have previously been shown to secrete transforming growth factor-β (TGFβ) and to be growth inhibited by exogenous TGFβ. The purpose of the present studies was to determine whether the endogenous TGFβ(s) were regulating the growth of RTE cell cultures and, if so, which isoforms were involved. Neutralizing antibodies specific to TGFβ1 and TGFβ2 were added to cultures, and their effects on several growth parameters were measured. Addition of antibodies to early cultures (day 1), resulted in 1.8-and 3-fold increases in colony formation and cell number, respectively, above control IgG-treated cultures. Antibody dose-response experiments revealed that TGFβ2 was the predominant isoform inhibiting early RTE cell growth. The antibody treatments resulted in similar stimulation of early growth at low and high seeding densities, suggesting that the endogenous TGFβs were acting locally. Anti-TGFβ1 treatment of cultures at various stages of growth resulted in 1.2-1.7-fold increases in DNA synthesis above controls, whereas anti-TGFβ2 treatment resulted in increased DNA synthesis only in early and late cultures (1.7- and 2.5-fold, respectively), but not during midlogarithmic growth. Continuous treatment with a combination of both antibodies resulted in increased growth and decreased exfoliation in early cultures, but had no effect on the slow down of growth in late cultures. Thus endogenous TGFβs inhibited primarily early growth and contributed to, but did not appear to be responsible for, plateau of growth in late stage cultures. Antibody treatment of secondary cultures resulted in 4-70-fold increases in colony formation, depending on the age of the primary cultures when replated, indicating that endogenous production of both TGFβ1 and TGFβ2 greatly inhibits the subculturability of primary RTE cells. Other experiments suggested that cholera toxin enhances RTE cell growth in part by counteracting the inhibitory effects of endogenous TGFβs. © 1993 Wiley-Liss, Inc.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...