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  • 1
    Electronic Resource
    Electronic Resource
    Copenhagen : Munksgaard International Publishers
    Clinical oral implants research 8 (1997), S. 0 
    ISSN: 1600-0501
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: The objective of the present investigation was to characterize the cellular composition of the soft tissues surrounding consecutively retrieved late failures of Brånemark implants. Criteria for implant failure were signs of loss of osseointegration (radiographic peri-fixtural radiolucency and mobility). The clinical history of the implants did not include adverse symptoms. At the time of retrieval, percussion-induced pain was experienced at 4/S implants, but no macroscopical signs of inflammation or infection was observed. Immunohistochemistry was applied on 6 marginal peri-implant specimens and on specimens of deeper tissues associated with the previously load-bearing implant surface from 8 failed implants, whereas 6 clinically healthy mucosal specimens and 4 hyperplastic biopsies from stable implants served as controls. The immunohistochemical evaluation showed that the soft tissues surrounding failed implants contained a large number of macrophages (CD68), HLA-DR positive cells, lymphocytes and plasma cells preferentially accumulated towards the removed implant surface. PMNs were a rare finding. Downgrowth of epithelium, in some cases encapsulating the whole fixture, was observed in sections where an intact implant/soft tissue interface was preserved. Healthy control mucosal specimens always contained labelled cells, albeit in a low amount, whereas hyperplastic control samples displayed an intense inflammatory and immunological response with numerous positive cells and PMNs scattered throughout the biopsy. In conclusion, failed implants were characterized by a chronic inflammatory response of the surrounding tissues with macrophages as the predominant labelled cell type, while hyperplastic tissues around stable implants were distinguished by an acute inflammatory process. These findings suggest that an on-going infection is unlikely to be the etiological factor for the late failures of dental implants examined in this study.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 113 (1971), S. 441-449 
    ISSN: 1432-0878
    Keywords: Noradrenergic nerves ; Terminals ; Uptake of 5-hydroxytryptamine ; Electron microscopic autoradiography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The uptake and distribution of radioactivity in vascular adrenergic nerves in the mouse pancreas following the injection of tritiated 5-hydroxytryptophan was studied by means of electron microscopic autoradiography. Autoradiographic silver grains were found selectively accumulated over axonal profiles. Quantitative analysis revealed a characteristic intraneuronal distribution of the silver grains, most of which probably represent 5-hydroxytryptamine formed by decarboxylation from the labeled precursor. Thus, the grain density over adrenergic nerve terminals, containing a mixed population of vesicles and granules, was about 5 times higher than the grain density recorded over non-terminal axonal parts and at least 20 times higher than the grain density found over surrounding adventitial tissue and smooth muscle cells. This was interpreted as an evidence that 5-hydroxytryptamine was taken up and stored in adrenergic terminals.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 206 (1980), S. 73-81 
    ISSN: 1432-0878
    Keywords: Exocrine pancreas (mouse) ; Electron microscopic autoradiography ; Microtubules ; Protein transport ; Vinblastine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The effect of vinblastine on the intracellular transport of newly synthesized protein in the mouse exocrine pancreas in vivo was studied by electron microscopic autoradiography after administration of 3H-leucine. Vinblastine (1.1 μmole/mouse; i.v. injection) was in general given 1 h before radioleucine and 2–4 h before fixation of the pancreas by perfusion with glutaraldehyde. Vinblastine causes the disappearance of microtubules, mainly present in controls in the apical portion of the acinar cell. After injection of vinblastine, zymogen granules form clusters located throughout the cell but often associated with Golgi areas. The latter are enlarged mainly due to the accumulation of small vesicles. In addition, Golgi areas are displaced, most often in an apical direction. Electron microscopic autoradiography demonstrated that vinblastine delays the appearance of labeled protein in zymogen granules; even 2 h after injection of radioleucine the majority of silver grains is located over the rough endoplasmic reticulum while very few grains are related to zymogen granules. This finding might be related to the structural changes of the Golgi areas observed. Although intracellular migration of protein is retarded, zymogen granules are formed. However, many of the labeled granules are found in peculiar locations, often distant from the acinar lumen. The present study suggests that vinblastine, possibly due to its effect on microtubules, influences both the formation and the translocation of zymogen granules.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 236 (1984), S. 87-97 
    ISSN: 1432-0878
    Keywords: Iodination ; Membrane shedding ; Peroxidase ; Thyroid follicle cell ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Clusters of luminal dense bodies, limited by a triple-layered membrane, were found in all follicle lumina in thyroid glands of mice. After thyroxine treatment the number of luminal dense bodies increased, especially in the periphery of the lumen, where the intraluminal bodies often displayed a striking resemblance to microvilli. In hyperplastic goiters, obtained by feeding mice with propylthiouracil, luminal dense bodies were replaced by intraluminal vesicles. During goiter involution the vesicles were gradually replaced by luminal dense bodies; the presence of intermediate forms suggests that vesicles and dense bodies are basically the same formations. Luminal dense bodies were observed in colloid droplets indicating their removal by endocytosis. As demonstrated by electron-microscopic cytochemistry, luminal dense bodies contain a membranebound peroxidase, and electron-microscopic autoradiography after administration of 125I indicate that they possess an iodinating capacity. Our observations on mouse thyroid glands suggest that the luminal dense bodies, which appear as vesicles in hyperplastic glands, are formed by shedding of the apical plasma membrane of the follicle cell. The shedding process might be of importance for the turnover of plasma-membrane material.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 126 (1972), S. 182-192 
    ISSN: 1432-0878
    Keywords: Thyroid ; Parafollicular cells ; Adrenergic nerves ; 3H-L-DOPA uptake ; Autoradiography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The cellular and subcellular distribution of radioactivity in the mouse thyroid gland different times (20 min — 8 hours) after intravenous administration of 3H-L-DOPA was studied by means of quantitative electron microscopic autoradiography. High concentrations of autoradiographic silver grains occur over parafollicular cells and adrenergic nerves while the labelling of follicular cells and lumina is low or absent and similar to the labelling of connective tissue cells at all observation times. Over the parafollicular cells high levels of radioactivity can be recorded already 20 min after administration of the labelled amino acid. The grain counts are highest at 1 hour and decrease then at 2.5 and 8 hours. The intracellular distribution of label is similar at all observation times; thus, the concentration of silver grains over the typical cytoplasmic granules of the parafollicular cells is 4–5 times higher compared to the concentration over the remainder of the cytoplasm and the nucleus. Treatment with a decarboxylase inhibitor prior to the injection of 3H-L-DOPA results in a low and uniform labelling of all thyroid cells. This finding, taken together with the observation that also pretreatment with reserpine abolishes the autoradiographic reaction over the cytoplasmic granules, gives strong support to the idea that the great majority of silver grains observed over parafollicular cells represents dopamine formed by decarboxylation of the labelled precursor.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 128 (1972), S. 406-425 
    ISSN: 1432-0878
    Keywords: Parafollicular Cells ; Rat ; Normalcalcemia ; Vitamin D2 ; Electronmicroscopy ; Histochemical fluorescence method
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Thyroid parafollicular cells of normocalcemic and vitamin D2-treated rats were investigated by electron microscopy and with the histochemical fluorescence technique of Hillarp and Falck. Administration of high doses of vitamin D2 caused hypercalcemia and an extensive degranulation of the parafollicular cells. The formation and storage of monoamines in granulated and degranulated parafollicular cells was investigated by fluorescence microscopy after injection of monoamine precursors (DOPA, 5-HTP), alone or in combination with Ro 4-4602, nialamide or reserpine. No fluorescence was observed in parafollicular cells of untreated rats. l-DOPA and l-5-HTP (but not the corresponding D-amino acids) were taken up by a process closely linked to the decarboxylation of the amino acids to the corresponding amines (dopamine and 5-hydroxytryptamine). Treatment with vitamin D2 did not seem to affect the formation of amines in the parafollicular cells or the formation and storage of amines in other cell systems investigated. The amine itself (dopamine) was not taken up by the parafollicular cells. In normocalcemic rats, the amine formed was retained in the cytoplasm of the parafollicular cells by a partially reserpine-resistant mechanism. The storage of amines is concluded to occur in association with the calcitonin-containing granules. In parafollicular cells of vitamin D2-treated rats, a certain amount of amine was bound in the cytoplasm in the absence of typical granules. As a considerable amount of calcitonin is known to remain in the thyroid of vitamin D2-treated rats, the present observations may indicate an association between the amine and the polypeptide hormone calcitonin, whether the latter is confined to typical granules or not.
    Type of Medium: Electronic Resource
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  • 7
    ISSN: 1432-0878
    Keywords: Endostyle ; Autoradiography ; Cytochemistry ; Iodination ; Protothyroid ; Salpa fusiformis, Thalia democratica, Dolioletta gegenbauri, Doliolum nationalis (Tunicata)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The protothyroid region in the endostyles of four species of tunicates was examined by means of autoradiography and cytochemistry, at both the light and electronmicroscopic levels. To reveal the primary binding site for iodine, autoradiography was carried out on endostylar tissue from animals that had been incubated with high activity 125I- over a short period of time. The specific iodine binding enzyme, a peroxidase, was traced by its reaction with DAB. In accordance with previous findings, the iodinebinding cells proved to be the same as those containing the peroxidase. There were also strong indications of a secondary uptake of iodinated compounds and subsequent release into the body fluid. Together with the ultrastructural features, the data provided strong evidence indicating that these cells constitute a protothyroid region, which partly functions as an endocrine organ, possibly homologous with the vertebrate thyroid gland. Since the number of zones varied between the species, the numeration of the protothyroid region also varied. However, in all the examined endostyles, the protothyroid region was seen to be situated dorsolaterally to the glandular regions of the endostyle concerned with food capture.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    Journal of Biomedical Materials Research 24 (1990), S. 847-860 
    ISSN: 0021-9304
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine , Technology
    Notes: Ion implantation modifies the surface properties of different materials. We have compared the biological properties of titanium implanted with nitrogen with those of pure titanium. Implants were inserted in the abdominal wall of rats. The implants with surrounding tissue were excised after 1 and 6 weeks, and embedded in epoxy resin. The bulk metal was removed electrochemically and the tissue cut for light and electron microscopy. Using this technique the implant surface, formed by a thin oxide layer, remains and appears in sections as a dense line. After 1 week both types of implants were surrounded by a fluid space containing proteins and scattered macrophages but few polymorphonuclear granulocytes. The fluid space was wider around ionimplanted titanium (52 ± 22 μm) than around pure titanium implants (15 ± 3 μm). After 6 weeks the fluid space had largely disappeared around both type of implants. Around pure titanium implants macrophages and fibroblasts, quantified in 1-μm-thick sections in the light microscope, were present in about the same concentration in the inner tissue zone (within 25 μm from the implant surface). Around ion-implanted titanium macrophages predominated in the inner zone and multinuclear giant cells were present in almost all sections. Around both type of implants fibroblasts increased and macrophages decreased with increasing distance from the surface. In the electron microscope macrophages close to the surface of pure titanium were of small size and had an ultrastructure indicating a low activity. Macrophages close to ion-implanted titanium were large and had an active appearance as indicated by the presence of large amounts of endoplasmic reticulum and large Golgi areas in the cytoplasm. Our observations indicate that modification of the surface properties of titanium implants by ion implantation changes the biological properties.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
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