Library

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
    ISSN: 1471-4159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Abstract: The H3 receptor is a high-affinity histamine receptor that inhibits release of several neurotransmitters, including histamine. We have characterized H3 receptor binding in bovine brain and developed conditions for its solubilization. Particulate [3H]histamine binding showed an apparently single class of sites (KD= 4.6 nM; Bmax= 78 fmol/mg of protein). Of the detergents tested, digitonin at a detergent/protein ratio of 1:1 (wt/wt) yielded the greatest amount of solubilized receptors, typically 15–30% of particulate binding. Neither equilibrium binding of [3H]histamine to receptors (KD= 6.1 nM; Bmax= 92 fmol/mg of protein) nor the inhibitor profile was substantially altered by digitonin solubilization. However, solubilization did increase the rate of [3H]histamine association with and dissociation from the receptor. Size-exclusion chromatography indicated an apparent molecular weight of 220,000 for the solubilized receptor, and peak binding from this column retained its guanine nucleotide sensitivity. These last two observations are consistent with the solubilized receptor occurring in complex with a guanine nucleotide-binding protein.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    [s.l.] : Nature Publishing Group
    Nature 295 (1982), S. 605-607 
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] The antibiotics chloramphenicol and efrapeptin inhibit mitochondrial protein synthesis and ATPase, respectively, thereby killing sensitive (wild-type) mammalian cells. Various mutant cell lines have been isolated2'4 which are resistant to these drugs; we used these mutants to investigate the ...
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Cell lines were cloned from foci isolated after transfecting NIH 3T3 cells with plasmics expressing v-src (pMvsrc) (ref. 7), human bladder carcinoma activated ras (T24-6) or human c-Ha-ras (ras Cl-2) (S. Yokoyama, personal communication), poly-oma middle T or large T antigens (pPyMTl, pLT214) (ref. ...
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Inflammation research 40 (1993), S. 129-134 
    ISSN: 1420-908X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Agonist occupancy of high affinity histamine H3 receptors on AtT-20 cells induces increased ACTH release. However, the signal transduction process by which this occurs is presently unknown. As a first step in characterizing this pathway, we have examined the effects of a variety of nucleotides and nucleotide analogs on Na-methylhistamine binding to these receptors. Nonhydrolyzable guanine nucleotide analogs inhibit up to 40% of the [3H]Na-methylhistamine binding by increasing the dissociation rate of the ligand from the receptor and thereby, reducing receptor affinity. Pertussis toxin also decreases the affinity of the H3 receptors and ADP ribosylates a 41 kDa protein. Neither GTPγS nor pertussis toxin changeB max. These data indicate that the H3 receptors on these cells are coupled to a G protein of the Gi subclass.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Methods in cell science 4 (1978), S. 801-804 
    ISSN: 1573-0603
    Keywords: cell fusion ; hybridization ; PEG 400 MW ; homokaryon
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Somatic cell and molecular genetics 8 (1982), S. 15-21 
    ISSN: 1572-9931
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract A genetic technique has been developed for isolating nuclear hybrids which are products of fusion between karyoplasts and whole cells. Nuclear hybrids have a greatly reduced mitochondrial component obtained from the nuclear donor and exhibit differences when compared to the corresponding whole-cell hybrids, such as better long-term survival and accelerated chromosome segregation. These results suggest that divergent mitochondria in a cell-fusion product may have adverse effects on survival.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Somatic cell and molecular genetics 6 (1980), S. 455-464 
    ISSN: 1572-9931
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Mouse L-929 cells centrifuged in the presence of cytochalasin B (CB) separate into cytoplasmic (cytoplasts) and nuclear (karyoplasts) fractions, but both of these fractions contain some whole-cell contaminants. We describe here two techniques for eliminating most of these whole cells from the karyoplast population. The first involves incubating cells in the presence of tantalum (Ta) particles, followed by enucleation and separation, on a Ficoll gradient. The small karyoplasts separate from the whole cells which contain a greater number of Ta particles. The second procedure uses a cell sorter that allows purification of karyoplasts from whole cells on the basis of light scatter. Both methods remove the whole-cell contaminants and the larger, and possibly viable, karyoplasts from the smaller karyoplast population. These purified karyoplasts are unable to regenerate but may be rescued by fusion with cytoplasts.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 141 (1989), S. 142-147 
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: A differentiation-defective mouse myoblast subclone (DD-1), cells of which do not fuse into myotubes nor synthesize muslce-specific proteins, was employed to help define the role of eicosanoids in mouse myoblast differentiation. We observed by hplc, tIc, and radioimmunoassay that the DD-1 cells release strikingly higher levels of cyclooxygenase pathway products prostaglandin E2 and F2α into the culture medium than the parental non-differentiation-defective cells (DZ). In contrast, the levels of 15-hydroxyeicosatetraenoic acid (15-HETE), a lipoxygenase product, and a putatively identified second lipoxygenase product (LLP) did not differ greatly in the two cell types. The DD-1 cells also have strikingly higher levels of cyclooxygenase activity than the parental cells as determined by intact and broken cell assays. Additional fusion-defective clones were isolated on the basis of their flattened appearance and ability to grow in “mitogen-poor” medium and these cells also released strikingly higher levels of prostaglandins E2 and F2α into the growth medium. The “turn on” of the cyclooxygenase pathway in the DD-1 cells and other fusion-defective cells is consistent with the hypothesis that the products of this pathway contribute to the inability of myoblasts to fuse with one another. This hypothesis is supported by the observation that there is a dose-dependent decrease in fusion of DZ cells when PGE2 is added to commitment medium.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    New York, N.Y. : Wiley-Blackwell
    Journal of Supramolecular Structure 11 (1979), S. 33-49 
    ISSN: 0091-7419
    Keywords: cell enucleation ; cell reconstruction ; nuclear control of tumorigenicity ; Life Sciences ; Molecular Cell Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: The techniques of somatic cell hybridization have provided a valuable means of studying mechanisms of regulation of mammalian cell differentiation and transformation. Most previous studies have indicated that fusions between tumorigenic and nontumorigenic cells result in hybrid cells that are usually tumorigenic. In recent years it has been demonstrated that the phenotypic expression of tumorigenicity is at least partially due to the extensive chromosome loss that occurs in most interspecific and some intraspecific hybrid cells. In the present study we have utilized enucleation techniques that permit cells to be divided into nuclear (karyoplast) and cytoplasmic (cytoplast) cell fragments. Even though these nuclear and cytoplasmic fragments are metabolically stable for short periods of time, in our hands they ultimately degenerate. Viable cells can be reconstructed by PEG-induced fusion of karyoplasts to cytoplasts. Since reconstructed cells apparently do not segregate chromosomes, they may provide a clearer understanding of the interactions between the nucleus and the cytoplasm in the control of the expression of tumorigenicity. We have reconstructed cells using karyoplasts from the tumorigenic Y-1 cell line and cytoplasts from a nontumorigenic cell line, A-MT-BU-A1. In addition we have reconstructed cells containing Y-1 cytoplasts and A-MT-BU-A1 karyoplasts. The reconstructed cells porduced were assayed for tumorigenicity by their ability to grow in soft agar and in nude mice. The results of these experiments indicate that the reconstructed cells containing a tumorigenic nucleus and a nontumorigenic cytoplasm ultimately are tumorigenic and conversely the reconstructed cells containing a nontumorigenic nucleus and a tumorigenic cytoplasm are nontumorigenic. These experiments support the concept that with these cell lines the nucleus (karyoplast) is sufficient to control the phenotypic expression of tumorigenicity.
    Additional Material: 18 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Supramolecular Structure and Cellular Biochemistry 16 (1981), S. 75-82 
    ISSN: 0275-3723
    Keywords: cytoplasmic hybrids ; suppression of tumorigenicity ; Chemistry ; Molecular Cell Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: We investigated cytoplasmic control of tumorigenicity in cybrids. Cytoplasts derived from nontumorigenic cells were fused to the highly tumorigenic 984 Cl 10-15 cell line derived from a murine teratoma. The resultant cybrids did not retain the tumorigenicity of the original cell line. In addition, the majority demonstrated the ability to differentiate into skeletal muscle. The results of these experiments indicate a heritable suppression of the tumorigenic phenotype by nontumorigenic cytoplasm. These findings are in contrast to our previous experiments in which we used a different experimental system and demonstrated a nuclear control of tumorigenicity in cybrids.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...