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  • 1
    ISSN: 1432-1203
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In 1885 Carl Rabl published his theory on the internal structure of the interphase nucleus. We have tested two predictions of this theory in fibroblasts grown in vitro from a female Chinese hamster, namely (1) the Rabl-orientation of interphase chromosomes and (2) the stability of the chromosome arrangement established in telophase throughout the subsequent interphase. Tests were carried out by premature chromosome condensation (PCC) and laser-UV-microirradiation of the interphase nucleus. Rabl-orientation of chromosomes was observed in G1 PCCs and G2 PCCs. The cell nucleus was microirradiated in G1 at one or two sites and pulse-labelled with 3H-thymidine for 2h. Cells were processed for autoradiography either immediately thereafter or after an additional growth period of 10 to 60h. Autoradiographs show unscheduled DNA synthesis (UDS) in the microirradiated nuclear part(s). The distribution of labelled chromatin was evaluated in autoradiographs from 1035 cells after microirradiation of a single nuclear site and from 253 cells after microirradiation of two sites. After 30 to 60h postincubation the labelled regions still appeared coherent although the average size of the labelled nuclear area fr increased from 14.2% (0h) to 26.5% (60h). The relative distance dr, i.e. the distance between two microirradiated sites divided by the diameter of the whole nucleus, showed a slight decrease with increasing incubation time. Nine metaphase figures were evaluated for UDS-label after microirradiation of the nuclear edge in G1. An average of 4.3 chromosomes per cell were labelled. Several chromosomes showed joint labelling of both distal chromosome arms including the telomeres, while the centromeric region was free from label. This label pattern is interpreted as the result of a V-shaped orientation of these particular chromosomes in the interphase nucleus with their telomeric regions close to each other at the nuclear edge. Our data support the tested predictions of the Rabl-model. Small time-dependent changes of the nuclear space occupied by single chromosomes and of their relative positions in the interphase nucleus seem possible, while the territorial organization of interphase chromosomes and their arrangement in general is maintained during interphase. The present limitations of the methods used for this study are discussed.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Human genetics 〈Berlin〉 31 (1976), S. 47-52 
    ISSN: 1432-1203
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Cytogenetic studies of an 8-year-old caucasian girl with typical but mild manifestation of Bloom's syndrome showed a characteristic increase of homologous chromatid translocations and prematurely condensed chromosomes. The average frequency of sister chromatid exchanges (SCE) in lymphocytes with 133 was much higher than in skin fibroblasts with 49. The inter- and intrachromosomal distributions of SCE in lymphocytes were analyzed.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 1432-1920
    Keywords: Key words Magnetic resonance imaging ; experimental ; Brain stem
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Our purpose was to investigate the potential of an experimental animal coil using a commercial MRI unit to delineate the anatomical structure of the human brain stem. Three formaldehyde-fixed brain-stem specimens were examined by MRI and sectioned perpendicular to their longitudinal axis. The images were compared with gross anatomy and myelin-stained histological sections. Fibre tracts and nuclei which were not evident on examination of the unstained specimen were readily identified by MRI. Due to its inherent grey/white matter contrast, MRI with a high-resolution coil delineates anatomical structures in a way comparable to the myelin-stained histological sections. However, pigmented structures, readily visible on examination of the unstained specimen were discernible on neither MRI nor on myelin-stained sections. The excellent anatomical detail and grey/white matter contrast provided by these images could make MRI a useful adjunct to the pathologist investigating brain disease.
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 1432-1920
    Keywords: Magnetic resonance imaging, experimental ; Brain stem
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Our purpose was to investigate the potential of an experimental animal coil using a commercial MRI unit to delineate the anatomical structure of the human brain stem. Three formaldehyde-fixed brain-stem specimens were examined by MRI and sectioned perpendicular to their longitudinal axis. The images were compared with gross anatomy and myelin-stained histological sections. Fibre tracts and nuclei which were not evident on examination of the unstained specimen were readily identified by MRI. Due to its inherent grey/white matter contrast, MRI with a highresolution coil delineates anatomical structures in a way comparable to the myelin-stained histological sections. However, pigmented structures, readily visible on examination of the unstained specimen were discernible on neither MRI nor on myelin-stained sections. The excellent anatomical detail and grey/white matter contrast provided by these images could make MRI a useful adjunct to the pathologist investigating brain disease.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Chromosoma 83 (1981), S. 541-553 
    ISSN: 1432-0886
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Premature chromosome condensation (PCC) was induced in order to study the arrangement of muntjac chromosomes in the interphase nuclei of proliferating and resting cells with respect to their polarity and the spatial relationship between them. The data were compared with the situation in in situ fixed and colcemid blocked metaphases. It appears that in rapidly dividing cells almost all G1- and G2 interphase chromosomes exhibit the Rabl type polarized orientation. This pattern still predominates in G0 lymphocytes which may have been arrested at this stage for some months or even years. — The location of the small chromosome Y2 was found to be “central” in normal metaphases but “peripheral” in colcemid blocked mitoses. The behavior in the premature condensed chromosome preparations was intermediate. Measurements of centromere distances between all possible pairs of chromosomes as well as on the relative position of chromosomes in circular spreads revealed no evidence for homologous somatic association during interphase and metaphase or any other suprachromosomal ordering principle. Interphase chromosome orientation seems to be solely the result of chromosome arrangement of the foregoing anaphase. Association between heterochromatic regions or the nucleolus organizers did not substantially influence this pattern. There is no support for speculations that in mammalian cells close proximity of homologoues sites is instrumental in functional cooperation.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Journal of molecular medicine 41 (1963), S. 1163-1164 
    ISSN: 1432-1440
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Zusammenfassung An sechs Patienten mit Diabetes mellitus wurden intravenöse Rastinon- und Rastinon-Propapheninbelastungen vorgenommen. Die erhaltenen Blutglucosemittelwertskurven zeigen gewisse zeitliche und quantitative Differenzen hinsichtlich der hypoglykämisierenden Rastinonwirkung, die den Schluß zulassen, daß es unter dem Einfluß von Chlorpromazin zu einer mäßiggradigen Inhibition des Stoffwechseleffektes kommt, ohne daß jedoch ein prinzipieller Unterschied der Kurvencharakteristik deutlich wird.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Langenbeck's archives of surgery 379 (1994), S. 256-263 
    ISSN: 1435-2451
    Keywords: Necrotizing enterocolitis ; Neonates ; C-reactive protein
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Vom 01.01.1986 bis 31.12.1991 wurden in unserer Klinik 10 Patienten wegen einer schweren NEC (Stadium II oder III nach Bell) behandelt. Die Inzidenz war in der Patientengruppe sehr kleiner Frühgebo-rener am höchsten (Geburtsgewicht 〈 1000 g: 3/123 (2,4%); 1000–1500 g: 2/308 (0,6%); 1501–2000 g: 3/436 (0,7%); 〉 3000 g: 2/ca. 30000 (0,006%) Lebendgeborene). Die NEC zeigte sich bei allen Patienten zunächst durch die klinische Symptomatik mit geblähtem Abdomen, blutigem Stuhl, Nahrungsunverträglichkeit und Mikrozirkulationsstörungen. Entzündungszeichen, wie eine erhbhte CRP-Konzentration von 〉 0.6 mg/dl, ein pathologischer I/T-Quotient 〉 0,16 oder eine auffällige Gesamtzahl der neutrophilen Granulozyten lagen nur zum Zeitpunkt der Diagnosestellung bei 4/10 Patienten vor. Im Verlauf zeigten jedoch alle Patienten erhöhte CRP-Konzentrationen (Maximum 2.–4. Tag, Normalisierung 8.–10. Tag). Unter konservativer Therapie traten in der akuten Krankheitsphase bei 9/10 Patienten keine Komplikationen auf, ein Kind entwickelte am 6. Krankheitstag eine Perforation. Nur dieses Frühgeborene wurde in der akuten Krankeitsphase laparotomiert. Bei 3 Patienten kam es im weiteren Verlauf zu narbigen Kolonstenosen, die elektiv zwischen dem 51. und 77. Lebenstag operiert wurden. Alle 10 Patienten haben die Erkrankung überlebt. Ob eine frühzeitige chirurgische Intervention, wie von einigen Arbeitsgruppen empfohlen, der konservativen Therapie überlegen ist, bleibt unklar. Während bei Verdacht auf eine Perforation oder Gangrän die Indikation zur sofortigen Operation unumstritten ist, stellt in den weitaus meisten Fallen eine primär konservative Therapie unserer Ansicht nach ein gutes Behandlungskonzept dar. Die Prognose einer späteren elektiven chirurgischen Therapie von Stenosen des Intestinums ist gut.
    Notes: Abstract Within a 6-year period ten patients with necrotizing enterocolitis (grade II–III; Bell) have been treated at the University Hospital, GBttingen. The following NEC incidences were calculated: birth weight 〈 1000 g: 2.4% (3/123); 1000–1500 g: 0.6% (2/308); 1501–2000 g: 0.7% (3/436); 〉 3000 g: 0.006% (2/30000 live births). In all patients onset of necrotizing enterocolitis (NEC) was associated with typical clinical symptoms such as abdominal distension, feeding problems, bloody stools. Only four out of ten patients had positive blood tests of various inflammatory parameters when diagnosed (C-reactive protein, neutrophil count, I/T-ratio). However, increased CRP levels were observed in all patients during the course of the disease (maximum levels: day 2–4 after diagnosis). During primarily conservative therapeutic management only one out of ten patients developed bowel perforation (day 6 after diagnosis) and immediate surgical treatment was carried out. In addition, in three patients who acquired strictures with obstruction of the colon, elective surgery was performed at a postnatal age of 51–77 days. All patients survived NEC without longterm sequelae. We conclude that a primarily conservative therapeutic regimen — whenever perforation and gangrene are absent — may be an alternative to early surgical intervention in NEC.
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