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
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Science Ltd
    European journal of neuroscience 13 (2001), S. 0 
    ISSN: 1460-9568
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: The glutamate transporters GLT-1 and GLAST localized in astrocytes are essential in limiting transmitter signalling and restricting harmful receptor overstimulation. To show changes in the expression of both transporters following lesion of the entorhinal cortex (and degeneration of the glutamatergic tractus perforans), quantitative microscopic in situ hybridization (ISH) using alkaline-phosphatase-labelled oligonucleotide probes was applied to the outer molecular layer of the hippocampal dentate gyrus of rats (termination field of the tractus perforans). Four groups of rats were studied: sham-operated controls, and animals 3, 14 and 60 days following unilateral electrolytic lesion of the entorhinal cortex. The postlesional shrinkage of the terminal field of the perforant path, ipsilateral to the lesion side, was determined and considered in the evaluation of quantitative ISH data. Statistical analysis revealed that ipsilateral to the lesion side there was a significant decrease of the GLT-1 mRNA at every postlesional time-point and of the GLAST mRNA at 14 and 60 days postlesion. The maximal decrease was ≈ 45% for GLT-1 and ≈ 35% for GLAST. In the terminal field of the perforant path contralateral to the lesion side, no significant changes of ISH labelling were measured. The results were complemented by immunocytochemical data achieved using antibodies against synthetic GLT-1 and GLAST peptides. In accordance with ISH results, there was an obvious decrease of GLT-1 and GLAST immunostaining in the terminal field of the perforant path ipsilateral to the lesion side. From these data we conclude that, following a lesioning of the entorhinal cortex, the loss of glutamatergic synapses in the terminal field of the perforant path resulted in a strong downregulation of glutamate transporters in astrocytes. The decrease of synaptically released glutamate or of other neuronal factors could be involved in this downregulation.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 100 (2000), S. 106-110 
    ISSN: 1432-0533
    Keywords: Key words Posterior pituitary ; Ganglion cell ; Immunohistochemistry ; Ectopia ; Transdifferentiation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Histologic examination revealed large ganglion cells within the posterior pituitary of an 80-year-old woman who died of myocardial infarction. Apparently fully mature, the cells were an incidental finding scattered within hyperplastic foci of pars intermedia (PI)-derived cells (basophil invasion) on histologic examination of the pituitary obtained at autopsy. Immunocytochemistry showed staining reactivity for neuron-specific enolase, synaptophysin, alpha subunit of the glycoprotein hormones and beta-endorphin. The presence of these ganglion cells with features similar to those of magnocellular hypothalamic neurons could be considered the result of abnormal migration during the early phase of embryonic life, or differentiation/maturation of neuroblasts, presumed to occur in the embryonic neurohypophysis. Alternatively, transdifferentiation from proliferating PI cells may explain the emergence of neurons; a hypothesis supported by the proximity and shared alpha subunit, and beta-endorphin immunoreactivities of the two cell types.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 1432-2307
    Keywords: Key words Pituitary ; Human ; Somatotroph ; Thyrotroph hyperplasia ; Immunocytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  In patients with protracted primary hypothyroidism, the pituitary is enlarged due to the lack of feedback inhibition by thyroid hormone. In the present work, adenohypophysial biopsies from three women with protracted primary hypothyroidism were investigated by routine histology, immunocytochemistry, double immunostaining, immunoelectron microscopy, and combined immunocytochemistry – in situ hybridization. These methods confirmed the presence of massive thyrotroph hyperplasia and the formation of ”thyroidectomy” or ”thyroid deficiency” cells. A number of thyroidectomy cells were found to be immunoreactive for growth hormone (GH). Double immunostaining and immunoelectron microscopy revealed the presence of bihormonal cells containing both GH and thyroid stimulating hormone (TSH). Immunostaining combined with in situ hybridization revealed GH immunoreactive cells expressing TSH mRNA as well as TSH immunopositive cells expressing GH mRNA. Our findings provide conclusive evidence that somatotrophs may transform to thyrotrophs. Thus, in addition to multiplication of thyrotrophs, transdifferentiation of GH cells to thyrotrophs contributes to the increase of TSH-producing cells. The presence of such bihormonal cells best termed ”thyrosomatotrophs” supports the concept that adenohypophysial cells are not irreversibly committed to the production of one single hormone and that their phenotype can change in response to functional demand.
    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
    European archives of oto-rhino-laryngology and head & neck 257 (2000), S. 212-215 
    ISSN: 1434-4726
    Keywords: Key words Laryngeal cancer ; Frontolateral partial ; laryngectomies ; Myofascial reconstruction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The indications and problems of organ-preserving vertical partial laryngectomy (VPL) in cases of T1b glottic or T2 glottic and subglottic cancers are well known. The first and imperative requirement for the surgeon is adequate resection of tumor while the second prerequisite is the safe and successful correction of the excised portion of the anterolateral wall of the larynx. Since reconstruction of the defect can cause significant challenges for surgeons, the main requirements are an adequate lumen for breathing, a smooth surface for epithelialization, voice restoration and good deglution. Krajina’s method for reconstruction of the larynx utilizes pedicled sternohyoid fascia, which is thin, elastic, well adaptable to defects, and resistent to infection or saliva. By providing a large surface for covering defects, granulations and synechiae can be prevented. We now use the superficial fascia colli as a new method for reconstruction of laryngeal defects after frontolateral partial resections. The technique was first refined experimentally in dogs. A Leroux-Robert partial laryngectomy was carried aut on five animals and laterally pedicled fascia was sutured to the edge of the defect created. At 2-week intervals through 8 weeks after the operation fixation, vascularization and epithelialization were examined histologically. To date, clinical reconstruction with the fascial flap has been used in 29 cases. Because the flap has a very low metabolism, no necrosis was seen. Functional results of respiration, phonation and swallowing have been good. These findings show that laterally pedicled fascia with the bipedicled sternohyoid muscles can play an important role in laryngeal reconstruction.
    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...