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  • 1975-1979  (18)
  • 1
    Electronic Resource
    Electronic Resource
    Acrosomal chromocentre in newt spermiogenesis (1975)
    [s.l.] : Nature Publishing Group
    Nature 257 (1975), S. 795-797 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Adult Triturus alpestris, T. cristatus and T. vulgaris were captured from their natural habitat near Ulm, southwestern Germany; T. marmoratus was caught in southern France (Banyuls-sur-Mer) and Diemyctilus viridescens was obtained from a dealer. Four hours before they were killed, the animals ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/257795a0
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    Paper (German National Licenses)
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  • 2
    Electronic Resource
    Electronic Resource
    Fluorescein angiography of free gingival autografts (1975)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of clinical periodontology 2 (1975), S. 0 
    Details
    ISSN: 1600-051X
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Abstract The capillary blood circulation of free gingival autografts during healing was studied by means of 45 fluorescein angiographs taken over a postoperative period of 14 days in 10 female patients, 21 to 36 years old. The surgical technique commonly used for transplanting gingiva was slightly modified in that no surgical dressings and, in 3 cases, not even sutures were employed to immobilize the grafts.During the first 3 postoperative days, fluorescent plasmatic diffusion of increasing intensity was observed. In one case, fluorescing capillary circulation was detected as early as 24 hours after surgery. Four days after surgery, fluorescent capillaries became evident in all graft sites and increased steadily in number. Between 9 and 14 days after surgery, an even capillary loop pattern was established.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1600-051X.1975.tb01740.x
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    Paper (German National Licenses)
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  • 3
    Electronic Resource
    Electronic Resource
    Endometriosis of the lung (1975)
    Springer
    Archives of gynecology and obstetrics 218 (1975), S. 219-226 
    Details
    ISSN: 1432-0711
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Es wird über den ersten Fall einer klinisch und histologisch gesicherten miliaren Erscheinungsform der Lungenendometriose berichtet. Das Leitsymptom war eine Haemoptoe, die jeweils zur Zeit der Periode auftrat und unter hohen Gestagendosen verschwand. Der Lungenbefund bildete sich jedoch erst nach operativer Kastration zurück. Pathogenese und Häufigkeit werden kurz dargestellt. Als Grundlage dienten die 11 bisher publizierten Fälle. Unter Hinweis auf experimentelle und klinische Erfahrung wird die Ansicht vertreten, daß die Lungenendometriose durch hämatogene Aussaat im Gefolge von Operationen am Uterus oder von Schwangerschaften zustande kommt. Die Bedingungen für ein Überleben des Endometriums in der Lunge sind ungeklärt. Als Therapie wird die hochdosierte Gestagenmedikation, bei deren Scheitern die operative Kastration empfohlen.
    Notes: Summary The first case of a clinically and histologically verified miliary form of endometriosis of the lung is reported here. The cardinal symptom was a menstrually synchronised hemoptysis, which by treatment with high doses of progestins disappeared. After operative castration a complete remittence with normal chest X ray was attained. Pathogenesis and frequency were briefly described. The 11 previously published cases served as a basis. Taking into account experimental and clinical experience, we propound the opinion the endometriosis of the lung occurs via hematological spread as a result of uterine operations or pregnancy. The conditions under which endometrium survives in the lung remain uncertain. Large doses of gestagen drugs are to be recommended as therapy and should be this prove unsuccessful operative castration.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00667382
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  • 4
    Electronic Resource
    Electronic Resource
    Chromosome banding in amphibia (1979)
    Springer
    Chromosoma 71 (1979), S. 29-55 
    Details
    ISSN: 1432-0886
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The distribution of constitutive heterochromatin on the chromosomes of Triturus a. alpestris, T. v. vulgaris and T. h. helveticus (Amphibia, Urodela) was investigated. Sex-specific chromosomes were determined in the karyotypes of T. a. alpestris (chromosomes 4) and T. v. vulgaris (chromosomes 5). The male animals have one heteromorphic chromosome pair, of which only one homologue displays heterochromatic telomeres in the long arms; the telomeres of the other homologue are euchromatic. This chromosome pair is always homomorphic and without telomeric heterochromatin in the female animals. There is a highly reduced crossing-over frequency between the heteromorphic chromosome arms in the male meiosis of T. a. alpestris; in T. v. vulgaris no crossing-over at all occurs between the heteromorphic chromosome arms. No heteromorphisms between the homologues exist on the corresponding lampbrush chromosomes of the female meiosis. In T. h. helveticus no sex-specific heteromorphism of the constitutive heterochromatin could be determined. The male animals of this species, however, already possess a chromosome pair with a greatly reduced frequency of chiasma-formation in the long arms. The C-band patterns and the pairing configurations of the sex-specific chromosomes in the male meiosis indicate an XX/XY-type of sex-determination for the three species. A revision of the literature about experimental interspecies hybridizations, gonadic structure of haploid and polyploid animals, and sex-linked genes yielded further evidence in favor of male heterogamety. The results moreover suggest that the heterochromatinization of the Y-chromosome was the primary step in the evolution of the sex chromosomes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00426365
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  • 5
    Electronic Resource
    Electronic Resource
    Chromosome banding in amphibia (1978)
    Springer
    Chromosoma 68 (1978), S. 131-148 
    Details
    ISSN: 1432-0886
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract In the chromosomes of 12 frog species of the suborder Diplasiocoela (Amphibia, Anura), the constitutive heterochromatin and the nucleolus organizer regions (NORs) have been specifically stained. On most of the chromosomes, aside from the centric heterochromatin, telomeric and interstitial C-bands were also found. The various C-bands display a very variable reaction to alkaline pretreatment; this indicates heterogeneity in the constitutive heterochromatin. Sex chromosomes could not be identified in any of the species studied. The number and chromosomal positions of the NORs vary quite strongly between species and between families. In 4 species of the genus Rana, there were, aside from the “standard-NORs” in chromosome pair 10, between 4 and 14 extra, small NORs detectable in the smaller chromosome pairs. As possible causal mechanism of these additional small NORs the reintegration of amplified rDNA during amphibian oogenesis is suggested. Q- or G-bands could only be recognized in mitotic prophase chromosomes. The strong spiralization of metaphase chromosomes prevents the differential demonstration of Q- or G-bands in the euchromatic regions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00287145
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  • 6
    Electronic Resource
    Electronic Resource
    Chromosome banding in Amphibia (1978)
    Springer
    Chromosoma 66 (1978), S. 361-388 
    Details
    ISSN: 1432-0886
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The distribution and quantity of constitutive heterochromatin and of the nucleolus organizer regions (NORs) on the chromosomes of 22 species of bufonids and hylids (Amphibia, Anura) was investigated. Three different kinds of constitutive heterochromatin were found and the frequency of brightly fluorescing heterochromatic regions was remarkably high. On almost all chromosomes there is centric and telomeric heterochromatin. Quantitative estimates of heterochromatin demonstrate that large DNA differences among closely related species can not be attributed to differing quantities of constitutive heterochromatin. In all species investigated, only one homologous pair of NORs was found, which lies preferentially in the proximal and interstitial segments of the long chromosome arms. The NORs are always associated with constitutive heterochromatin on both sides. The size variability between homologous NORs is very high. In the euchromatic regions of the metaphase chromosomes, neither Q- nor G-bands can be demonstrated; this can be attributed to an extremely strong contraction of the anuran chromosomes. On the basis of these results various mechanism of the chromosomal evolution in Anura are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00328536
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  • 7
    Electronic Resource
    Electronic Resource
    On the arrangement of chromosomes in the elongated sperm nuclei of Anura (amphibia) (1979)
    Springer
    Chromosoma 75 (1979), S. 215-234 
    Details
    ISSN: 1432-0886
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The position of specific constitutive heterochromatic chromosome regions within the elongated sperm nuclei of eight species of Anura was examined with Q- and C-banding. These species differ widely with regard to the number, size and position of the brightly fluorescing heterochromatic regions. The empirical frequency distributions determined for the heterochromatic regions relative to the longitudinal axis of the sperm nuclei were compared with random frequency distributions calculated on the basis of two spatial models. None of the specifically stained heterochromatic regions occupy any definite preferential position within the sperm nuclei. In two instances, a specific sequence of the heterochromatic regions within the sperm nuclei could be excluded. The type of chromosomal arrangement within the elongated sperm nuclei of Anura is discussed on the basis of the distribution patterns obtained.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00292209
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  • 8
    Electronic Resource
    Electronic Resource
    Frequency of Ag-stained nucleolus organizer regions in the acrocentric chromosomes of man (1977)
    Springer
    Human genetics 〈Berlin〉 37 (1977), S. 73-77 
    Details
    ISSN: 1432-1203
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The Ag-stainability of the nucleolus organizer region (NOR) was studied in the acrocentric chromosomes identified by Q-banding of cultured lymphocytes in 51 karyotypically normal persons (31 males and 20 females). A consistent pattern of Ag-positive NORs was found in each individual. Ninety percent of the individuals have a modal number of 8–10 Ag-positive NORs per cell. The frequency of Ag-positive NORs is similar in all five acrocentrics. A statistically nonsignificant lower frequency is found in chromosome 22. Ag-negative NORs on both homologues were found in four cases. The observed frequency distribution of individuals with homozygous NOR-positive, heterozygous, and homozygous negative acrocentric chromosomes was in accordance with the Hardy-Weinberg law in all five pairs of the acrocentric chromosomes as well as in total. No sex difference was observed in our material.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00293774
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  • 9
    Electronic Resource
    Electronic Resource
    Activation of mouse ribosomal RNA genes at the 2-cell stage (1977)
    Springer
    Human genetics 〈Berlin〉 38 (1977), S. 57-63 
    Details
    ISSN: 1432-1203
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The Ag-AS method, developed by Goodpasture and Bloom (1975) stains transcriptionally active nucleolus organizer regions (NORs) on the chromosomes and in the interphase nuclei. Metaphases and interphase nuclei of early mouse embryos (unfertilized eggs, pronucleus stages, 2-, 4-, 8-cell stages, and morulae) were subjected to silver-staining. First staining of a single chromosome bearing an NOR was observed at the 2-cell stage. At the 4-cell stage 4–6 chromosomes, and at the 8-cell stage invariably all the 6 chromosomes known to bear NORs, respond positively to silver-staining. These results indicate that during mouse embryogenesis ribosomal RNA genes start to function at the 2-cell stage. The polar body does not respond to silver-staining, which supports the view that the polar body genome remains inactive.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00295808
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  • 10
    Electronic Resource
    Electronic Resource
    Evidence for postmeiotic expression of ribosomal RNA genes during male gametogenesis (1977)
    Springer
    Human genetics 〈Berlin〉 38 (1977), S. 279-284 
    Details
    ISSN: 1432-1203
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Pre- and postmeiotic stages of male gametogenesis of 10 different vertebrate species belonging to mammals, birds, amphibians, and fishes were subjected to the Ag-AS staining technique (Goodpasture and Bloom, 1975). A uniform pattern of silver-staining is observable during spermatogenesis of the different vertebrate species. Silver-staining is present in spermatogonia and during the whole period of meiotic prophase, but totally absent during diakinesis and metaphase II of meiosis. In early spermatids silver-staining reappears and only disappears around the beginning of elongation of the spermatid nucleus. Since the Ag-AS technique is believed to stain only transcriptionally active nucleolus organizer regions, our findings indicate that ribosomal RNA genes become reactivated in the haploid spermatid.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00402153
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