ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

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
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 23 (1992), S. 222-230 
    ISSN: 0886-1544
    Keywords: native electrophoresis ; tubulin isotypes ; dimerization ; complexes ; GTP binding ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The functional subunit of microtubules is a heterodimer consisting of α- and β-tubulin. An understanding of tubulin dimerization has been hampered because it has not proved possible to purify native tubulin monomers. To study the process whereby tubulin dimers are formed, we made use of tubulins synthesized by in vitro transcription and translation. We present evidence that the in vitro synthesis of different mouse α-tubulin isotypes involves a multimolecular complex. The synthesis of mouse β-tubulin isotypes also involves the formation of multimolecular complexes, though different isotypes behave somewhat differently from one another. The properties of in vitro synthesized α- and β-tubulin multimolecular complexes strongly suggest that they are intermediates in the biosynthesis of tubulin monomers. Upon release, these monomers can exchange with pre-existing tubulin heterodimers. © 1992 Wiley-Liss, Inc.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 46 (1991), S. 21-26 
    ISSN: 0730-2312
    Keywords: hemopoiesis ; ES cells ; myoblasts ; osteoblasts ; hepatocytes ; neurones ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: The notion that a single hormone may exert a broad range of effects has become well established. As such, leukemia inhibitory factor (LIF) is a prime example. LIF was initially described, purified, and genetically cloned on the basis of its ability to induce the differentiation and suppress the clonogenicity of the monocytic leukemia cell line, M1. Subsequently, it has become apparent that in vitro LIF inhibits the differentiation of pluripotential ES cells, stimulates the synthesis of hepatic acute-phase proteins, induces a switch in neurotransmitter phenotype from adrenergic to cholinergic, suppresses adipocyte lipoprotein lipase activity, and results in an increase in bone resorption. Moreover, elevation of LIF levels in vivo has a number of patho-physiological consequences, many of which parallel those effects observed in vitro. The challenge that lies ahead is to determine whether other sites of LIF action exist and to define more clearly the physiological role LIF plays in vivo.A major mechanism of cell-cell communication is by the production and secretion of polypeptide hormones by one cell type, which act either systemically or locally, via interaction with specific receptors on the surface of responsive cells. Recently, it has become apparent that hormones initially described and named, on the basis of a specific action, in many cases exert a spectrum of effects on a broad range of cell types. Moreover, the effects exerted are often mimicked closely by other hormones. Hormones that act in a pleiotropic manner are, for example, transforming growth factor-β (TGF-β), the various fibroblast growth factors (FGFs), interleukin-6 (IL-6), and leukemia inhibitory factor (LIF). This review will focus on the various biological effects ascribed to LIF.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 46 (1991), S. 69-77 
    ISSN: 0730-2312
    Keywords: cytokines ; cell proliferation ; polyamines ; cytotoxicity ; growth factors ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: The activity of the polyamine biosynthetic enzyme, ornithine decarboxylase (ODC), has been shown to be rapidly modulated by a variety of growth regulatory molecules. In this report the effect of the growth modulatory peptide, tumor necrosis factor, on ODC activity was examined on two cell lines which express equivalent TNF binding properties, but differ in their growth response when exposed to this factor. TNF treatment of WI-38 fibroblasts stimulated both their growth and induced ODC activity 5-10-fold when measured 6-24 h after TNF incubation. TNF induced cytotoxicity in ME-180 cervical carcinoma cells and, interestingly, stimulated both ODC activity (3-6-fold) and putrescine accumulation when measured prior to the onset of cytotoxicity. Induction of ODC was TNF concentration-dependent and paralleled the concentration-dependency for cytotoxicity. Based upon studies with cycloheximide, de novo protein biosynthesis was required for TNF-mediated ODC induction in ME-180 cells.The effects of other growth inhibitory peptides and growth factors were analyzed for their combined effect on ODC activity in TNF-treated or untreated ME-180 cells. Interferon gamma treatment had no significant effect on basal ODC activity but inhibited TNF-mediated ODC induction by ∼50%. EGF treatment resulted in a potent stimulation of ODC activity which was not effected by TNF pre-treatment or coadministration on ME-180 cells. These results suggest that TNF has properties which are similar to those of a growth factor and distinct from those of other growth inhibitory peptides. The early growth factor-like actions of TNF occur on both normal fibroblasts and some tumor cells and evidence suggests that these effects are antagonistic to the antiproliferative effects of TNF.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    ISSN: 0730-2312
    Keywords: 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
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: 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.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 53 (1993), S. 314-322 
    ISSN: 0730-2312
    Keywords: neurodegeneration ; TGF-β ; Alzheimer's disease ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: TGF-β1 mRNA and protein were recently found to increase in animal brains after experimental lesions that cause local deafferentation or neuron death. Elevations of TGF-β1 mRNA after lesions are prominent in microglia but are also observed in neurons and astrocytes. Moreover, TGF-β1 mRNA autoinduces its own mRNA in the brain. These responses provide models for studying the increases of TGF-β1 protein observed in βA/amyloid-containing extracellular plaques of Alzheimer's disease (AD) and Down's syndrome (DS) and in brain cells of AIDS victims. Involvement of TGF-β1 in these human brain disorders is discussed in relation to the potent effects of TGF-β1 on wound healing and inflammatory responses in peripheral tissues.We hypothesize that TGF-β1 and possibly other TGF-β peptides have organizing roles in responses to neurodegeneration and brain injury that are similar to those observed in non-neural tissues. Work from many laboratories has shown that activities of TGF-β peptides on brain cells include chemotaxis, modification of extracellular matrix, and regulation of cytoskeletal gene expression and of neurotrophins. Similar activities of the TGF-β's are well established in other tissues.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 55 (1994), S. 389-397 
    ISSN: 0730-2312
    Keywords: signal transduction ; protein tyrosine kinase ; T lymphocytes ; recombinant protein ; p56lck ; p60src ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: The lymphocyte-specific, nonreceptor protein tyrosine kinase Lck has been purified from an Escherichia coli expression system using a monoclonal antibody column followed by dye-affinity chromatography. Polyacrylamide gel electrophoretic analysis of purified protein revealed a single 56 kDa band, indicating that recombinant Lck was purified to near-homogeneity. The purified enzyme displayed tyrosine kinase activity as measured by both autophosphorylation and phosphorylation of exogenous substrates. Biochemical properties including protein phosphorylation and kinetic characteristics of the enzyme have been assessed. Peptide map analysis revealed that bacterially expressed Lck is phosphorylated predominantly on the autophosphorylation site (tyrosine-394), which is characteristic for activated protein tyrosine kinases. Indeed, we found that the recombinant enzyme is approximately fivefold more active than Lck from resting T cells, which is extensively phosphorylated at the regulatory carboxy-terminal tyrosine residue (tyrosine-505). Thus, we have overproduced recombinant human Lck in E. coli and developed a simple two-step purification procedure which yields highly active enzyme. This will enable the identification and characterization of potential regulators and targets of Lck and thereby greatly facilitate studies which will clarify its role in T cell signal transduction. © 1994 Wiley-Liss, Inc.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 35 (1993), S. 316-323 
    ISSN: 1040-452X
    Keywords: Capacitation ; Progesterone ; Ionomycin ; Follicular fluid ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Mammalian sperm do not respond to inducers of the acrosome reaction immediately after ejaculation. They become responsive after they are removed from seminal plasma and incubated in an appropriate medium. We tested the effects of seminal plasma on the development of acrosomal responsiveness. Washed human sperm incubated 24 hr in vitro with 10% (v/v) seminal plasma did not complete an acrosome reaction when exposed to human follicular fluid, progesterone, or ionomycin. Seminal plasma did not reduce sperm viability or motility. Electron microscopy of sperm incubated 24 hr with 5% seminal plasma and then treated with progesterone revealed no sign of membrane fusion or other changes that are associated with the acrosome reaction. During a 12-hr incubation, seminal plasma was 50% effective at inhibiting the acrosomal response to progesterone when diluted 821 ± 112 foid (mean ±SD, n = 3). Sperm that were incubated with seminal plasma for 24 hr and then washed free of the seminal plasma became acrosomally responsive over the following 24 hr, at a rate similar to that of sperm not incubated with seminal plasma in vitro. When sperm were incubated 6 hr without seminal plasma and then seminal plasma was added, the sperm population transiently became more responsive to progesterone, and then became unresponsive. During incubation in vitro, the ability of sperm to have an augmented response to a mixture of seminal plasma plus progesterone developed slightly earlier and more rapidly than ability to respond to progesterone alone. When sperm were incubated 24 hr without seminal plasma, a few acrosome reacted in response to the addition of seminal plasma alone. Therefore, depending on how it is applied, seminal plasma can prevent or reverse the development of acrosomal responsiveness, and it can enhance or induce the acrosome reaction. © 1993 Wiley-Liss, Inc.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 35 (1993), S. 285-292 
    ISSN: 1040-452X
    Keywords: Oocyte ; Mouse ; Surface labelling ; Proteins ; Biotinylation ; Chemiluminescence ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: In this study, we have labelled proteins on the surface of unfertilized, zona-free mouse oocytes using a nonisotopic biotinylation procedure. The zona pellucida was weakened by brief incubation in chymotrypsin and removed by mechanical pipetting through a narrow-bore glass pipette. Surface proteins were labelled using sulfo-NHS-biotin (sulfosuccinimidobiotin), a water-soluble, membrane-impermeable biotinylation reagent. The distribution of biotinylated proteins on the oocyte surface was assessed by fluorescence microscopy using streptavidin-FITC. Bright fluorescence was noted on the surface of the oocyte, except in a circular region overlying the meiotic spindle where the fluorescence was weak or absent. The intensity of fluorescence was markedly reduced by incubation of biotinylated oocytes in trypsin (1 mg/ml) or chymotrypsin (2 mg/ml), and in vitro fertilization experiments showed that biotinylation did not compromise the fertilizability of the oocytes. The biotinylated proteins were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and analyzed by Western blotting using streptavidin-HRP and enhanced chemiluminescence (ECL) detection. The most prominent biotinylated proteins were of Mr 82 and 69 kD, but other major proteins of Mr 93, 78, 61, 52, 49, 40, 28, and 22 kD were detected, as well as 14 minor proteins of Mr 18-100 kD. The major bands could be detected in fewer than 50 oocytes. This biotinylation procedure is fast, versatile and sensitive, and it is therefore an excellent tool for studying proteins exposed on the surface of mammalian oocytes and embryos. © 1993 Wiley-Liss, Inc.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    ISSN: 0044-8249
    Keywords: Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    ISSN: 0044-8249
    Keywords: Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...