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
    facet.materialart.
    Unknown
    Design and chemical synthesis of a homogeneous polymer-modified erythropoiesis protein (2003)
    American Association for the Advancement of Science (AAAS)
    Details
    Publication Date: 2003-02-08
    Description: We report the design and total chemical synthesis of "synthetic erythropoiesis protein" (SEP), a 51-kilodalton protein-polymer construct consisting of a 166-amino-acid polypeptide chain and two covalently attached, branched, and monodisperse polymer moieties that are negatively charged. The ability to control the chemistry allowed us to synthesize a macromolecule of precisely defined covalent structure. SEP was homogeneous as shown by high-resolution analytical techniques, with a mass of 50,825 +/-10 daltons by electrospray mass spectrometry, and with a pI of 5.0. In cell and animal assays for erythropoiesis, SEP displayed potent biological activity and had significantly prolonged duration of action in vivo. These chemical methods are a powerful tool in the rational design of protein constructs with potential therapeutic applications.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Kochendoerfer, Gerd G -- Chen, Shiah-Yun -- Mao, Feng -- Cressman, Sonya -- Traviglia, Stacey -- Shao, Haiyan -- Hunter, Christie L -- Low, Donald W -- Cagle, E Neil -- Carnevali, Maia -- Gueriguian, Vincent -- Keogh, Peter J -- Porter, Heather -- Stratton, Stephen M -- Wiedeke, M Con -- Wilken, Jill -- Tang, Jie -- Levy, Jay J -- Miranda, Les P -- Crnogorac, Milan M -- Kalbag, Suresh -- Botti, Paolo -- Schindler-Horvat, Janice -- Savatski, Laura -- Adamson, John W -- Kung, Ada -- Kent, Stephen B H -- Bradburne, James A -- New York, N.Y. -- Science. 2003 Feb 7;299(5608):884-7.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Gryphon Therapeutics, 250 East Grand Avenue, Suite 90, South San Francisco, CA 94080, USA. Gkochendoerfer@gryphonRX.com〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/12574628" target="_blank"〉PubMed〈/a〉
    Keywords: Amino Acid Sequence ; Animals ; Cell Line ; Circular Dichroism ; *Drug Design ; Drug Stability ; Electrophoresis, Polyacrylamide Gel ; *Erythropoiesis ; Erythropoietin/chemistry/pharmacology ; Hematocrit ; Humans ; Isoelectric Point ; Mice ; Molecular Sequence Data ; Molecular Structure ; Molecular Weight ; *Polymers/*chemical synthesis/*chemistry/pharmacokinetics/pharmacology ; Protein Folding ; Proteins/*chemical synthesis/*chemistry/pharmacokinetics/pharmacology ; Rats ; Receptors, Erythropoietin/drug effects/metabolism ; Recombinant Proteins ; Spectrometry, Mass, Electrospray Ionization
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Published by American Association for the Advancement of Science (AAAS)
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 2
    Electronic Resource
    Electronic Resource
    Cellular and molecular mechanisms of arm regeneration in crinoid echinoderms: the potential of arm explants (1998)
    Springer
    Development genes and evolution 208 (1998), S. 421-430 
    Details
    ISSN: 1432-041X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Crinoid echinoderms can provide a valuable experimental model for studying all aspects of regenerative processes from molecular to macroscopic level. Recently we carried out a detailed study into the overall process of arm regeneration in the crinoid Antedon mediterranea and provided an interpretation of its basic mechanisms. However, the problem of the subsequent fate of the amputated arm segment (explant) once isolated from the animal body and of its possible regenerative potential have never been investigated before. The arm explant in fact represents a simplified and controlled regenerating system which may be very useful in regeneration experiments by providing a valuable test of our hypotheses in terms of mechanisms and processes. In the present study we carried out a comprehensive analysis of double-amputated arm explants (i.e. explants reamputated at their distal end immediately after the first proximal amputation) subjected to the same experimental conditions as the regenerating donor animals. Our results showed that the explants undergo similar regenerative processes but with some significant differences to those mechanisms described for normal regenerating arms. For example, whilst the proximal-distal axis of arm growth is maintained, there are differences in terms of the recruitment of cells which contribute to the regenerating tissue. As with normal regenerating arms, the present work focuses on (1) timing and modality of regeneration in the explant; (2) proliferation, migration and contribution of undifferentiated and/or dedifferentiated/transdifferentiated cells; (3) putative role of neural growth factors. These problems were addressed by employing a combination of conventional microscopy and immunocytochemistry. Comparison between arm explants and regenerating arms of normal donor adults indicates an extraordinary potential and regenerative autonomy of crinoid tissues and the cellular plasticity of the phenomenon.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004270050199
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Organization and mechanical behaviour of myocyte–ligament composites in a sea-urchin lantern: the compass depressors of Stylocidaris affinis (Echinodermata, Echinoida) (1998)
    Springer
    Zoomorphology 118 (1998), S. 87-101 
    Details
    ISSN: 1432-234X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Certain components of the jaw apparatus, or lantern, of regular sea-urchins form a ’compass system’ the function of which has still to be established. This system includes ten compass depressors (CDs) which connect the compass ossicles to the inner edge of the test. Previous studies focused on the CDs of euechinoid sea-urchins. This paper provides the first detailed account of the organization and mechanical behaviour of the CDs of a cidaroid sea-urchin, Stylocidaris affinis. The outermost layer of its CDs is a coelothelium comprising apical peritoneocytes, sparse subapical myocytes and two types of granule-containing cells. The central core of the CD is dominated by longitudinally orientated collagen fibrils arranged in bundles surrounded by networks of beaded microfibrils. Myocytes are scattered throughout the core and are always surrounded by a basal lamina which usually encloses the same two types of granule-containing cells observed in the coelothelium. Each CD is attached to the outer coelomic septum by a mesentery, both the connective tissue and coelothelia of which lack myocytes and granule-containing cells. From data on the relationship between the vertical position of the lantern and the passive and active forces developed by intact CD sets, it appears that the CDs resist elevation of the lantern above its ’resting position’ and that they develop a maximal contractile force when their length corresponds to that at the resting position. The connective tissue of the CDs has the capacity to undergo nervously mediated changes in stretch resistance, although this is expressed more weakly than in the euechinoid CDs. These results are related to current views on the physiological role of the compass system.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004350050060
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    A spicule-reinforced contractile mesentery: organisation and mechanical behaviour of the exterior coelomic septum of Stylocidaris affinis (Echinodermata, Echinoida) (2000)
    Springer
    Zoomorphology 120 (2000), S. 119-133 
    Details
    ISSN: 1432-234X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  The exterior coelomic septum (ECS) is a mesentery-like structure that encloses the lantern of regular sea-urchins and connects it to the inner surface of the test. This paper describes the ultrastructure and microarchitecture of the ECS in Stylocidaris affinis (Cidaridae, Echinoida) and provides information on its contractile and passive mechanical properties. The ECS forms five interambulacral pouches each of which has adthecal (test-facing) and adambulacral (ambulacrum-facing) walls. The ECS wall comprises two coelothelia separated by a layer of connective tissue. The outer coelothelium is a single layer of monociliated cuboidal peritoneocytes and basally located axon-like processes. The inner coelothelium is a single layer of squamous peritoneocytes overlying axon-like processes and, in the adthecal regions only, parallel arrays of elongated myocytes orientated obliquely or horizontally. The intraseptal connective tissue consists mainly of collagen fibrils with sparsely distributed spherule cells and cells containing heterogeneous vesicles. In the adambulacral regions of the ECS hollow beaded microfibrils 20–23 nm in diameter form fibre-like aggregations. This layer also contains calcite spicules of variable size, shape, abundance and orientation. Isolated preparations of the ECS show concentration-dependent contractile responses to K+ ions and acetylcholine. The magnitude of the contractile force varies with the vertical position of the lantern (which determines the starting length of the ECS) in an unusual pattern. Cyclical loading-unloading tests indicate that, as the lantern is raised, the ECS shows low stiffness until the lantern reaches its normal resting position. It is concluded that the adthecal regions of the ECS help to set a limit to lantern retraction and that their contractility assists the protractor muscles in exerting a downward pull on the lantern.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004350000029
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    The Aristotle's lantern of the sea-urchin Stylocidaris affinis (Echinoida, Cidaridae): functional morphology of the musculo-skeletal system (1993)
    Springer
    Zoomorphology 113 (1993), S. 173-189 
    Details
    ISSN: 1432-234X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The Aristotle's lantern, or masticatory apparatus, of regular sea-urchins is a complex musculo-skeletal system which is thought to have contributed significantly to the evolutionary success of these animals. This paper gives an account of the antomical relationships and functional morphology of both skeletal and soft tissue components in the lantern and related structures of the sea-urchin Stylocidaris affinis (Cidaridae), and compares these features with their equivalent in the previously described lantern of the sea-urchin Paracentrotus lividus (Echinidae, Camarodonta). There are major differences in the skeletons of these lanterns which involve mostly the arrangement and morphology of elements participating in movement, i.e. joints and articular surfaces, and which highlight the generally heavier and less mobile nature of the lantern in the Cidaridae. There are remarkably few differences, however, in the microstructure of the skeletal stereom. Significant dissimilarities were found in the anatomical arrangement of muscles and ligamentous structures and in their macro- and microstructure. The implications of these morphological features for the functioning of the lantern of the Cidaridae are discussed in the context of an integrated model of lantern biomechanics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00394858
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    An unusual Z-system in the obliquely striated muscles of crinoids: three-dimensional structure and computer simulations (1986)
    Springer
    Journal of muscle research and cell motility 7 (1986), S. 568-578 
    Details
    ISSN: 1573-2657
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The peculiar functional structure of the Z-line in the obliquely striated muscles of some feather stars is described. It is known that cross-striated muscles are characterized by linear and continuous Z-bands, and obliquely striated muscles by disconnected, obliquely aligned Z-elements. Owing to this discontinuous organization, the sarcomere can perform wide active lengthenings, shortenings, and even ‘super-elongations’ in the helical fibres. In contrast, the obliquely striated fibres of crinoids show markedly continuous and homogeneous oblique Z-lines; such a structure is not compatible with ‘super-performances’ like sliding and shearing of the sarcomere elements, but instead could allow functions comparable to those characteristic of a cross-striated muscle (quick, short movements, mechanically amplifiable by bone levers). This odd situation, only interpretable in terms of evolutionary constraint, could be considered opposite and symmetrical to that of cross-striated ‘super-contracting’ muscles, where the Z-line is exceptionally fragmented to allow the sarcomere to super-contract. The possible architecture of a significant parameter such as the Z-line, which determines muscle fibre potential capacities, is analysed in detail: (1) through qualitative-quantitative evaluation of electron micrographs, supported by statistical analysis of the data; and (2) bycomputer simulations. The data obtained suggest that the most realistic conformation of the whole Z-complex in these muscles consists of a multiple system of continuous, ribbon-like helical planes running in parallel along the fibre from end to end and regularly cutting it with a constant thickness. The proposed model seems morphologically compatible with the experimentally verified situations and functionally compatible with the mechanical requirements for a normal contraction and for a balanced distribution of the involved strengths.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01753572
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Mechanical properties of sea-urchin lantern muscles: a comparative investigation of intact muscle groups in Paracentrotus lividus (Lam.) and Stylocidaris affinis (Phil.) (Echinodermata, Echinoidea) (1998)
    Springer
    Journal of comparative physiology 168 (1998), S. 204-212 
    Details
    ISSN: 1432-136X
    Keywords: Key words Echinodermata ; Echinoidea ; Lantern of Aristotle ; Muscle mechanics ; Force-length relations
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The jaw apparatus, or lantern, of sea-urchins contains five pairs of retractor and protractor muscles which are responsible for lantern displacement. Using intact retractor or protractor groups, the force-length relations of these muscles were compared in two taxonomically distant species, Paracentrotus lividus and Stylocidaris affinis. The total contractile forces generated by the muscles can be resolved into vertical and horizontal components. It was found that the vertical component of the retractors is maximal at a lantern position which is significantly lower (i.e. more protruded) in Paracentrotus than in Stylocidaris. Total forces generated by the retractors were in both species maximal at or above the lantern `resting positions'. In Paracentrotus alone, the total force-displacement curves tended to be bimodal. It is hypothesized that the retractors of Paracentrotus contain two populations of muscle fibres, one adapted for jaw opening and one for lantern retraction. No significant differences in the properties of the protractors of the two species could be identified. The lantern of Paracentrotus is more mobile than that of Stylocidaris and is able to exploit a wider range of food sources. This investigation has shown that the force-length relations of the lantern muscles match their differing working conditions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003600050138
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Localization of calcitonin gene-related peptide mRNA in developing olfactory axons (1998)
    Springer
    Cell & tissue research 294 (1998), S. 81-91 
    Details
    ISSN: 1432-0878
    Keywords: Key words Axonal mRNA ; Neuropeptide ; Olfactory pathway ; Development ; Mouse (CD1)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  During development of the olfactory pathway, calcitonin gene-related peptide (CGRP) expression is regulated both temporally and spatially. We had previous evidence that between E13 and E19 CGRP mRNA was present at the level of olfactory axons but the resolution of light-microscope in situ hybridization did not permit the axons to be distinguished from the closely apposed ensheathing cells. In this study, the localization of CGRP mRNA was studied at early developmental stages (E13–15) through in situ hybridization at the transmission electron-microscope (TEM) level. CGRP transcripts were observed exclusively in axons and not in ensheathing cells. The distribution of transcripts in the axons suggests that they are associated with intermediate filaments rather than microtubules. In addition, a careful ultrastructural analysis provided evidence that polysomes and membrane-bound ribosomes are present in such axons, suggesting that the peptide could be synthesized locally.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004410051158
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Tissue distribution of monoamine neurotransmitters in normal and regenerating arms of the feather star Antedon mediterranea (1996)
    Springer
    Cell & tissue research 285 (1996), S. 341-352 
    Details
    ISSN: 1432-0878
    Keywords: Key words: Dopamine ; Serotonin ; Nervous system ; Arm regeneration ; Antedon mediterranea (Echinodermata)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. Crinoid echinoderms can completely and rapidly regenerate arms lost following self-induced or traumatic amputation. Arm regeneration in these animals therefore provides a valuable experimental model for studying all aspects of regenerative processes, particularly with respect to the nervous system and its specific contribution to regenerative phenomena. Taking into account the primary role of the nervous system in regeneration in other invertebrates, we have investigated the specific involvement of neural factors, viz. the monoamine neurotransmitters dopamine and serotonin, in arm regeneration of Antedon mediterranea. In the present work, the presence of classical monoamines has been revealed by employing specific immunocytochemical and histofluorescence tests in association with biochemical detection by means of high pressure liquid chromatography. The distribution pattern of these neurohumoral molecules at standard regenerative stages has been compared with that of normal non-regenerating arms. Results indicate that both dopamine and serotonin dramatically change in both their distribution and concentration during the repair and regenerative processes. Their remarkably enhanced pattern during regeneration and widespread presence at the level of both nervous and non-nervous tissues indicates that they are important neural growth-promoting factors in crinoid arm regeneration.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004410050651
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Pattern of bromodeoxyuridine incorporation in the advanced stages of arm regeneration in the feather star Antedon mediterranea (1997)
    Springer
    Cell & tissue research 289 (1997), S. 363-374 
    Details
    ISSN: 1432-0878
    Keywords: Key words: Bromodeoxyuridine (BrdU) ; Proliferation ; Differentiation ; Regeneration ; Antedon mediterranea (Echinodermata)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. The overall process of arm regeneration in the crinoid Antedon mediterranea is a typical epimorphic process (blastemal regeneration). This can be subdivided into three main phases: a repair phase, an early regenerative phase, and an advanced regenerative phase. The crucial problem of the identification of cell lineages responsible for both repair and regenerative processes has been approached by monitoring cell proliferation during the advanced regenerative phase using light-microscopic and ultrastructural immunocytochemical methods to detect the incorporation of the thymidine analogue bromodeoxyuridine (BrdU) into regenerating tissues. Various treatment protocols and BrdU incubation times have been employed and provided information not only on the sources, sites of proliferation, and recruitment times of the new cells, but also on the cell lineage involved and subsequent fate (differentiation and/or migration) of the labelled cells. Our results are consistent with the following conclusions: (1) The arm regeneration process is due to a massive intervention of active proliferating cells identifiable as migratory, morphologically undifferentiated cells (amoebocytes and coelomocytes). (2) The preferential proliferation sites of these cells are the terminal blastema, the coelomic epithelium, and the brachial nerve of both the regenerating arm and the stump, even far from the amputation. (3) The two main cell components contributing to the regenerate have different origins: the blastemal cells and all the cell lineages derived from the amoebocytes; the coelomic cells from the migratory coelomocytes, in their turn derived from proliferation of the coelomic epithelium. (4) The blastemal regeneration of Antedon is due to a combined recruitment of pluripotent elements, implying the intervention of presumptive stem cells (amoebocytes) and the transdifferentiation/dedifferentiation of differentiated elements of the coelomic epithelium.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004410050883
    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...