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  • 1
    Electronic Resource
    Electronic Resource
    Structure of the amphibian mesonephric tubule during ontogenesis in Rana ridibunda L. tadpoles: early ontogenetic stages, renal corpuscle formation, neck segment and peritoneal funnels (1996)
    Springer
    Anatomy and embryology 193 (1996), S. 397-406 
    Details
    ISSN: 1432-0568
    Keywords: Kidney ; Mesonephric tubule ; Ontogenesis ; Amphibia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The morphological changes produced in the mesonephric tubule during ontogenesis, not previously reported in amphibians, are described in Rana ridibunda tadpoles using light and electron microscopic methods. The rudimentary nephron units do not develop synchronously along the subperitoneal nephrogenic ridged cord. The first signs of morphogenesis are the presence of round euchromatinic nuclei and mitotic figures. The subsequent developmental stages are characterized by detachment of the rudimentary nephrons from the nephrogenic cord. Renal corpuscle formation is characterized by glomerular expansion, differentiation of large fenestrated capillaries and the presence of a discrete mesangium and a small capsular space. Interstitial capillaries next to the renal corpuscle rudiments appear to induce invagination and differentiation of the capsular epithelium. Developing podocytes were cuboidal undifferentiated epithelial cells with scarce primary processes and with an extensive part of the cell surface lying flat on the glomerular basement membrane. These features reflect low or no glomerular filtration during nephron development. The ciliated neck segment and peritoneal funnels show similar structural features. The latter were not physically connected with the nephrons, but opened into renal blood vessels. Involutive peritoneal funnels were observed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00186696
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  • 2
    Electronic Resource
    Electronic Resource
    Anatomical and ultrastructural studies of chemical defence in the sponge Dysidea fragilis (1998)
    Springer
    Marine biology 131 (1998), S. 639-645 
    Details
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The marine sponge Dysidea fragilis from El Mar Menor, a hypersaline coastal lagoon (Murcia, Spain), contains the furanosesquiterpenoid ent-furodysinin as the major secondary metabolite. D. fragilis emits a defensive white fluid when it is disturbed. Electron micrographs of this fluid revealed intact vesiculated cells together with other amorphous material. Dissociated cells are more rounded in shape but maintain the same ultrastructural features as cells observed in ultra-thin sections of the whole sponge. The defensive secretion is composed mainly of sponge cells with abundant light vesicles. Sometimes these light vesicles appear to open into the intercellular space; this correlates with surface blebs on these cells observed under scanning electron microscopy. The intracellular location of ent-furodysinin was confirmed by Erlich staining. In laboratory assays, we examined the role of ent-furodysinin as a feeding deterrent to generalist fish predators. It was isolated from D. fragilis and incorporated into a carrageenan-based artificial diet. The addition of ent-furodysinin to the artificial diet reduced feeding by the fish Thalassoma pavo. Similarly, fish did not feed on artificial diet above which defensive secretion of D. fragilis had been ejected with a small syringe.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002270050356
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  • 3
    Electronic Resource
    Electronic Resource
    Water activity of culture media used in food microbiology (1990)
    Oxford, UK : Blackwell Publishing Ltd
    International journal of food science & technology 25 (1990), S. 0 
    Details
    ISSN: 1365-2621
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Notes: An improved gravimetric method was used to simultaneously determine (in a single assay) the water activity (aw) of 30 solid and liquid culture media covering the entire useful range of aw in food microbiology, including media recommended for osmophilic, halophilic and xerophilic organisms. The water activities of the media ranged between 0.999 and 0.739. As could be expected, the water activities of the solid media were not affected significantly by the presence of agar. No significant differences were observed either between the gravimetric (20°C) and the cryoscopic measurements (below 0°C) of liquid media of very high aw.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-2621.1990.tb01105.x
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  • 4
    Electronic Resource
    Electronic Resource
    An improved simple gravimetric method for measurement of high water activities (1989)
    Oxford, UK : Blackwell Publishing Ltd
    International journal of food science & technology 24 (1989), S. 0 
    Details
    ISSN: 1365-2621
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Notes: A previously reported gravimetric method for measurement of water activity (aw) has been simplified and improved, to determine aw in the range from about 0.700 to 0.999. Extrapolated aw values above 0.990 gave average underestimates of –0.001 aw units with the improved method. Comparative results on various dairy products were in good agreement with those found by a reference method (thermocouple psychrometer). The differences between the results provided by both methods were smaller for products with very high aw values than for products with high and intermediate aw values.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-2621.1989.tb00627.x
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  • 5
    Electronic Resource
    Electronic Resource
    Technical note: Water activity measurement near to 1.00 (1985)
    Oxford, UK : Blackwell Publishing Ltd
    International journal of food science & technology 20 (1985), S. 0 
    Details
    ISSN: 1365-2621
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-2621.1985.tb01962.x
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  • 6
    Electronic Resource
    Electronic Resource
    Methodological aspects of assessing phagocytosis of Vibrio anguillarum by leucocytes of gilthead seabream (Sparus aurata L.) by flow cytometry and electron microscopy (1998)
    Springer
    Cell & tissue research 293 (1998), S. 133-141 
    Details
    ISSN: 1432-0878
    Keywords: Key words Phagocytosis ; Vibrio anguillarum ; Flow cytometry ; Transmission electron microscopy ; Seabream (Sparus aurata L.)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract In this paper we optimize a flow cytometric method for evaluating the phagocytic activity of leucocytes in gilthead seabream (Sparus aurata L.) and characterize the phagocytic cells observed. Optimal conditions were established for the fluorescein-labelling and analysis of the bacterium Vibrio anguillarum by flow cytometry. Head-kidney leucocytes were incubated with the heat-killed fluorescein isothiocyanate (FITC)-labelled bacteria for different periods, during which the kinetics of phagocytosis was studied. Attached and interiorized bacteria were distinguished. Although phagocytic ability reached a maximum after 60 min, phagocytic capacity reached its maximum at 20 min. The amount of ingested bacteria per phagocyte was estimated from the mean fluorescence of the leucocytes. Cytochalasin B or colchicine was used to inhibit phagocytosis. Monocyte-macrophages and acidophilic granulocytes showed phagocytic activity as demonstrated by transmission electron microscopy. In conclusion, the technique presented allows the screening of thousands of cells, and individual cell evaluation, by quantifying interiorized particles in fish phagocytes. Our ultrastructural results demonstrate that V. anguillarum is actively phagocytized by seabream macrophages and acidophilic granulocytes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004410051105
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  • 7
    Electronic Resource
    Electronic Resource
    Determination of the acidity of supports and metal catalysts by the pulse technique (1987)
    Springer
    Reaction kinetics and catalysis letters 34 (1987), S. 395-400 
    Details
    ISSN: 1588-2837
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Abstract Импульсную технику применяли для определения кислотности различных твердых веществ и металлов на носителях, используя циклогексиламин (pKa=10,6) и пиридин (pKa5,25) в качестве титрующих веществ. Полученные результаты свидетельствуют о том, что отложения Pt приводят к повьшенным кислотным свойствам исследованных веществ.
    Notes: Abstract This paper reports the use of the pulse technique for the determination of the acidity of various solids and supported metal systems, using cyclohexylamine (pKa=10.6) and pyridine (pKa=5.25) as titrants. The results obtained show that the deposition of Pt results in increased acid properties in the solids investigated.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02068037
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  • 8
    Electronic Resource
    Electronic Resource
    Ultrastructure of the peritoneal exudate cells of seawater teleosts, seabream (Sparus aurata) and sea bass (Dicentrarchus labrax) (1993)
    Springer
    Cell & tissue research 273 (1993), S. 301-307 
    Details
    ISSN: 1432-0878
    Keywords: Peritoneum ; Peritoneal exudate cell (PEC) ; Granulocytes ; Lymphocytes ; Macrophages ; Sparus aurata, Dicentrarchus labrax (Teleostei)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The peritoneal exudates of seabream and sea bass consist of granulocytes, lymphocytes and macrophages. These cells show conspicuous ultrastructural differences from the same cell-types of blood and head-kidney, which have not been reported previously. Peritoneal exudate granulocytes differ from their corresponding circulating or head-kidney forms in the following way: (a) they are larger in size, and (b) their abundant cytoplasmic granules have some new ultrastructural features, and a new granule population might also be present. Likewise, lymphocytes also show a noticeable difference; they contain a sparse population of small dense cytoplasmic granules. Monocytes, macrophages, and transitional forms between these two cell-types, are also found. The percentage of peritoneal exudate cell-types is different in seabream and sea bass. Macrophages in sea bass represent the most abundant peritoneal exudate cell-type. However, seabream shows lower percentages of macrophages than granulocytes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00312832
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    Paper (German National Licenses)
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  • 9
    Electronic Resource
    Electronic Resource
    Melano-macrophages of the seawater teleosts, sea bass (Dicentrarchus labrax) and gilthead seabream (Sparus aurata): morphology, formation and possible function (1994)
    Springer
    Cell & tissue research 277 (1994), S. 1-10 
    Details
    ISSN: 1432-0878
    Keywords: Melano-macrophages ; Lysosomes ; Cytochemistry ; Phagocytosis ; Dicentrarchus labrax, Sparus aurata (Teleostein)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Melano-macrophages in the head-kidney, spleen and liver of sea bass and gilthead seabream have been investigated by means of light and electron microscopy, histochemistry and phagocytic assays. The results demonstrate the presence of both free and clustered melano-macrophages (melano-macrophage centres), with similar ultrastructural features. These large cells are PAS-, hemosiderin-and melanin-positive, and contain large, alkaline-and acid phosphatase-positive lysosomes, whose reaction intensity depends on the amount of accumulated pigment. The relationship between the cytochemical features of these lysosomes and the capacity of the melano-macrophages to phagocytose bacteria and latex beads, has been studied. The large melanomacrophage centres have a capsule of flattened cells, whose ultrastructural and cytochemical features are similar to fibroblast-like reticular cells. Melanin is the main accumulated pigment. A subpopulation of head-kidney mononuclear phagocytes engulfs melanin associated with cell debris. The relationship between the origin of the melano-macrophage pigment and the ability of monocytes/macrophages to phagocytise the melanin from melanocytes, is considered. The origin and possible function of melano-macrophage centres are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00303074
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