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  • 1995-1999  (1)
  • 1975-1979  (1)
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  • 1
    ISSN: 1432-0703
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Medicine
    Notes: Abstract. Physiological and biochemical biomarker responses were studied in juvenile whitefish (Coregonus lavaretus L. s.l.) exposed experimentally to effluent from the forest industry. The large study area (609 km2), Southern Lake Saimaa, in Southeast Finland, receives 330,000 m3 d−1 of biologically and 55,000 m3 d−1 of chemically treated effluents, discharged from two integrated elementary chlorine free (ECF) bleached kraft pulp and paper mills, from one ECF pulp mill, and from one mill producing unbleached pulp and cardboard. The assessment of exposure to effluent discharged from the mills was based on lake water chlorophenolics (CPs) and resin acids (RAs) measured in samples collected from the 22 experimental sites along the area. Despite the low levels of effluent constituents in the lake, they were still accumulated in detectable levels in fish bile, indicating an exposure to the bioactive compounds of effluents. In comparison to the reference area, a two- to four-fold increase in ethoxyresorufin O-deethylase (EROD) activity was observed in whitefish exposed in the vicinity (1–6 km) of all the mills. However, cytochrome P450 1A1 (CYP1A1) gene expression was increased in only one of the receiving areas, indicating higher sensitivity of the EROD activity in the present study. There were no statistically significant correlations between EROD activity and the ambient water concentrations of the CPs, the RAs, or effluent dilution expressed by water sodium concentration. Neither bile chlorophenolics nor bile resin acids showed a significant correlation with EROD. No significant changes in circulating reproductive steroids, 17β-estradiol and testosterone, in juvenile whitefish were observed. The vitellogenin gene was expressed in the vicinity of the pulp mill discharging the most wood-derived compounds, i.e. resin acids and wood-sterols, including β-sitosterol. No differences were observed in plasma immunoglobulin M, glucose, or lactate concentrations between the effluent sources.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 194 (1979), S. 429-443 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The ultrastructure of the urethral epithelium and mesenchyme of the 6- to 9-week-old human embryos was studied in order to reveal early morphological signs of prostatic development. The morphological changes of the urethral wall were correlated with the cytodifferentiation of the Leydig cells of the same embryos. Throughout the study the urethral epithelium had two or more layers of cuboidal cells. The ultrastructure of the cells was primitive and they did not achieve characteristics of the secretory prostatic cell. The surface cells had well developed apical junctions and slender cytoplasmic processes projecting into widened intercellular spaces appeared during the developmental period. The urethral mesenchyme showed the most salient changes. The mesenchymal cells adjacent to the urethral epithelium differentiated in the ninth week into fibroblast-like cells with an elongated shape and cytoplasmic processes. Granular endoplasmic reticulum appeared in the cytoplasm and collagen fibers were seen in the intercellular space. Mesenchymal cell processes contacting the continuous basal lamina under the epithelium were present. No direct epithelio-mesenchymal cellular contacts could be seen. The differentiation of the mesenchyme before the epithelial outgrowths suggests that the mesenchyme has an essential role in the glandular development.Electron microscopic study of the Leydig cells showed that the amount of agranular endoplasmic reticulum increased considerably in the ninth week. This agrees with earlier biochemical findings on the capability of Leydig cells to produce androgens by this time. The temporal relationship between the cytodifferentiation of Leydig cells and the urethral wall is consistent with the idea that in the human, fetal androgens induce prostatic development.
    Additional Material: 17 Ill.
    Type of Medium: Electronic Resource
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