Library

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
    Abnormalities in Myofibril Organization and Cell Shape in Developing Cardiomyopathic Hamster Heart Cells in Culture (1990)
    Oxford, UK : Blackwell Publishing Ltd
    Annals of the New York Academy of Sciences 588 (1990), S. 0 
    Details
    ISSN: 1749-6632
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Natural Sciences in General
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1749-6632.1990.tb13248.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Expression of axolotl RNA-binding protein during development of the Mexican axolotl (1999)
    Springer
    Cell & tissue research 297 (1999), S. 283-290 
    Details
    ISSN: 1432-0878
    Keywords: Key words RNA-binding domain ; Reverse transcriptase-polymerase chain reaction ; Northern blot analysis ; In situ hybridization ; Amphibian development ; Ambystoma mexicanum (Urodela)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  Amphibians occupy a central position in phylogeny between aquatic and terrestrial vertebrates and are widely used as model systems for studying vertebrate development. We have undertaken a comprehensive molecular approach to understand the early events related to embryonic development in the Mexican axolotl, Ambystoma mexicanum, which is an exquisite animal model for such explorations. Axolotl RBP is a RNA-binding protein which was isolated from the embryonic Mexican axolotl by subtraction hybridization and was found to show highest similarity with human, mouse, and Xenopus cold-inducible RNA-binding protein (CIRP). The reverse transcriptase polymerase chain reaction (RT-PCR) analysis suggests that it is expressed in most of the axolotl tissues except liver; the expression level appears to be highest in adult brain. We have also determined the temporal and spatial pattern of its expression at various stages of development. RT-PCR and in situ hybridization analyses indicate that expression of the AxRBP gene starts at stage 10–12 (gastrula), reaches a maxima around stage 15–20 (early tailbud), and then gradually declines through stage 40 (hatching). In situ hybridization suggests that the expression is at a maximum in neural plate and neural fold at stage 15 (neurula) of embryonic development.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004410051356
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    The ultimobranchial body in Rana pipiens (1967)
    Springer
    Cell & tissue research 78 (1967), S. 328-340 
    Details
    ISSN: 1432-0878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary 1. Subjacent to the parenchyma of the ultimobranchial body in the frog, unmyelinated nerves within the connective tissue have been found to terminate on the basal portion of a few secretory cells. The characteristic bulbous endings of these axons contain three types of vesicles characteristic of sympathetic adrenergic nerves. There is evidence to suggest that some fibers pass between epithelial cells and form a nervous network throughout the parenchyma. Accumulations of synaptic vesicles were also seen in relation to membrane specializations which were in contact with basement membranes. The configurations were observed at other levels of the axon located in the connective tissue matrix as well as in nerve endings on parenchymal cells. A possible physiological interpretation of the two different morphological types of “innervation” is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00325317
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    The ultimobranchial body in Rana pipiens (1968)
    Springer
    Cell & tissue research 85 (1968), S. 441-452 
    Details
    ISSN: 1432-0878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Hypercalcemia was induced in the frog, Rana pipiens in the winter months by the intramuscular injection of Vitamin D2 and maintenance of animals in 0.8% CaCl2 solution. After two weeks of treatment (200,000 I. U. Vitamin D2), the blood calcium rose to 15.2 mg- % from a normal of 9.2 mg- %, The ultimobranchial glands were examined by light microscopy and found to have undergone extensive cellular hypertrophy and tissue hyperplasia. Gland volume increased almost threefold over control glands and the nuclear/ cytoplasmic ratio was doubled. These changes were accompanied by an increased epithelial height, obliterated central lumen and enlarged capillaries. Similarly treated animals were then placed in fresh water for three weeks whereby the blood calcium levels returned to normal and the volume of the glands approached near normal levels. The paravertebral lime sacs were found to have undergone extensive filling under hypercalcemic conditions; X-rays were used as an additional aid to evaluate osteoporosis and calcium imbalance. The sensitivity of the ultimobranchial gland to hypercalcemia suggests an endocrine relationship; possibly this gland is the origin of a hypocalcemic factor related to the mammalian homolog, thyrocalcitonin.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00324739
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    The ultimobranchial body in Rana pipiens (1968)
    Springer
    Cell & tissue research 85 (1968), S. 453-465 
    Details
    ISSN: 1432-0878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Hypercalcemia was induced in male frogs by injection of Vitamin D2 and maintaining animals in calcium chloride water. The fine structure of the Ultimobranchial gland was examined 3, 7 and 14 days after the initial injection. The initial response observed after the third day was a depletion of secretory granules in addition to an alteration of nuclear shape and cytoplasmic hypertrophy. After seven days secretory granule depletion continued and early cell types occurred which indicated an increase in mitotic activity. There was also a demonstrable increase in the amount of ergastoplasm and hypertrophy of the Golgi apparatus. On the fourteenth day, the height of the epithelium was markedly increased while the underlying vascular network was enlarged and more intimately associated with the secretory parenchyma. The homeostatic mechanisms of the Ultimobranchial gland appear to include both a rapid secretory response upon stimulation and a cellular renewal system to replace exhausted cells. This suggests that such a glandular system provides a mechanism to supply a rapidly expanding cell population to meet the demands of an excessive depletion of secretory materials. The response of this gland to hypercalcemia supports previous studies which suggest that the Ultimobranchial gland is the probable source of the hypocalcemic hormone, calcitonin.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00324740
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    The ultimobranchial body in Rana pipiens (1965)
    Springer
    Cell & tissue research 66 (1965), S. 118-129 
    Details
    ISSN: 1432-0878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary 1. Electron micrographs of the ultimobranchial body in sexually mature Rana pipiens were prepared to describe the cytology of the parenchymal cells. 2. Cytoplasmic granules, enclosed within a limiting membrane, are approximately 1000 Å in diameter and are found at the apical and basal poles of the nucleus as aggregations and also in the basal cytoplasm in contact with the basal plasma membrane. 3. Lamellar bodies (myelin figures) of various complexities are found in all cells but are more prevalent in degenerating cells. Those structures found in the central lumen are a part of the cellular debris. 4. Lysosomes with densities similar to those of cytoplasmic granules suggest that some granules are not utilized. 5. Ergastoplasm within the parenchyma is scarce. The cytoplasm contains smooth membrane vesicles and free ribonucleoprotein (RNP) particles. 6. The ultimobranchial body is considered to have a low rate of protein synthesis. The degree of endocrine activity, if any, could not be determined at this time.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00339321
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    The ultimobranchial body in Rana pipiens (1965)
    Springer
    Cell & tissue research 67 (1965), S. 584-599 
    Details
    ISSN: 1432-0878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary 1. Electron micrographs of the ultimobranchial body in the young adult Rana pipiens reveal a variety of cell types. 2. Ovoid cells, with a well developed ergastoplasm, have an attachment only at the basement membrane and do not extend to the lumen surface. They are seen only beneath cells with a degenerate cytoplasm. 3. Elongate cells, with ergastoplasm, a Golgi apparatus and a few secretory granules, are found between degenerating cells. These apparently do not have a free apical border. 4. The predominant parenchymal cell, with an apical free border, possesses a perinuclear Golgi apparatus with densities within the vesicles which are similar to those of secretory granules. A basal migration of granules is suggested since subunits within the granules are released as an endocrine secretion across the basement membrane. 5. Cells with a “goblet” configuration, which contain lamellar bodies in a degenerate cytoplasm, are seen apical to cells with a well developed ergastoplasm. 6. The various cell types present in the follicular epithelium are suggestive of a maturation process of the parenchyma. This interpretation is based upon the relative position, the altered cytoplasmic components, the degree of attachment to adjacent cells and the endocrine secretory activity of the ultimobranchial body.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00340326
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    The ultimobranchial body in Rana pipiens (1968)
    Springer
    Cell & tissue research 90 (1968), S. 273-288 
    Details
    ISSN: 1432-0878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Autoplastic transplants of ultimobranchial glands of male Rana pipiens were bilaterally or unilaterally placed in a homeotopic or heterotopic site. Serum calcium levels were maintained at normal values in bilateral autotransplants, while total ultimobranchialectomy resulted in hypercalcemia. Electron microscopy verified the viability and functional state of transplanted, denervated glands. During the periods of denervation, ergastoplasm and Golgi membranes exhibited hypertrophy which was reversed when unmyelinated nerves reappeared in the pericapillary space. Autotransplants under hypercalcemic conditions indicated that the process of secretion is primarily an intrinsic cellular activity and independant of innervation. The present evidence suggests that the sympathetic axons which innervate the parenchyma probably are inhibitory in nature and may allow depression of glandular functions during periods of hypercalcemia.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00339434
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Observations on the ultimobranchial body in Rana pipiens (1964)
    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 148 (1964), S. 219-229 
    Details
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The ultimobranchial body was investigated in 63 specimens of Rana pipiens. The morphology is described for “typical” (unifollicular) glands and those found in animals in poor physiological (“stressed”) condition. The typical follicular epithelium is of a mixed pseudostratified type and includes “elongate” cells which extend from the basement membrane to the free surface. These contain elongated nuclei, prominent terminal lipid droplets and “deltoid bodies” which are triangular, homogeneously staining structures apical or basal to the nucleus. “Isometric” cells do not extend to the basement membrane. They posses intensely staining nuclei, few lipid droplets and no deltoid bodies. The stressed gland is multifollicular and degenerate. Mitochondria, lipid droplets, deltoid bodies and glycogen have been identified and are located in specific areas of the follicular cells. The secretory products within the lumina of the glands have tentatively been shown to contain acid mucopolysaccharides, carbohydrate-protein complexes, mucoproteins, lipid droplets and lipid complexes. These secretions may either represent possible precursors to future secretions or a retention of secretions produced during metamorphosis. The ultimobranchial body has shown no indication of degeneration in the adult.The ultimobranchial body in typical Rana is an active secretory gland which shows no indication of degeneration in normal adult anurans. Furthermore, it responds to fluctuations in environmental conditions as illustrated by its altered structure and varied types of secretion when stressed.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ar.1091480212
    Library Location Call Number Volume/Issue/Year 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...