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  • Carcinoma in situ  (1)
  • Differentiation  (1)
  • 1
    ISSN: 1432-1963
    Keywords: Schlüsselwörter Urothelkarzinom ; Carcinoma in situ ; Harnblase ; Urinzytologie ; Key words Transitional cell carcinoma ; Carcinoma in situ ; Urinary bladder ; Urinary cytology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary The surgical pathology of biopsies or electro-resection specimens taken from clinically sus-picious or overt tumors in the urinary bladder encompasses the evaluation of a few parameters. This should allow the segregation of bladder tumor patients into subgroups with distinct clinical features and biological behavior, thus providing a rationale for choos-ing the best available therapy. In essence, the pathologist’s role entails a careful morphologic assessment of the primary tumor, including evaluation of the histologic type, the growth pattern, the tumor grade, the tumor stage, and finally the presence and type of primary or tumor-associated flat intraurothelial lesions. Whereas the growth pattern of a lesion can be readily recognized, the correct grading and staging of papillary tumors are often more dependent on the complexity of the individual case and the experience of the pathologist due to the inherent subjectivity of the field and a lack of standardized criteria. These problems of intra- and interobserver variability are intimately cou-pled with the characteristics of the material, that is, bad orientation and tangential sectioning, thermal injury, crush and fixation artifacts, and limitations of the size of the samples. The correct evaluation and interpretation of flat intraurothelial lesions suffer from similar difficulties and are further complicated by a confusing categorization and terminology. Although new modalities and molec-ular approaches have been introduced in recent years in an effort to overcome some of these obstacles, morphology still remains the most effective means to assess the bio-logical behavior and prognosis of urothelial bladder cancer. The present article therefore addresses some of the diagnostically and clinically most relevant controversies and aims to give some useful hints for the evaluation of the above-mentioned morpho-logical parameters. In addition, it adds some remarks on the morphological basis and diag-nostic validity of urinary cytology in primary diagnosis and, more importantly, monitoring of bladder cancer patients.
    Notes: Zusammenfassung Der Alltag des Pathologen im Umgang mit Gewebeproben aus der Harnblase bei klinischem Tumorverdacht oder bei eindeutig verifizierten Neoplasien wird durch wenige, aber vielfach nicht einfach lösbare Fragen und Probleme bestimmt, die für den betroffenen Patienten von wesentlicher prognostischer und therapeutischer Bedeutung sind. Für urotheliale Tumoren sind dies im wesentlichen die verbindliche histologische Diagnose des Wachstumsmusters, die Feststellung von Malignitätsgrad und Stadium und die Präsenz primärer oder tumorassoziierter intraurothelialer Neoplasien bzw. deren Abgrenzung von reaktiven Urothelveränderungen. Während die Diagnose exophytischer, solid infiltrierender und flacher Urothelläsionen zumeist wenig Schwierigkeiten bereitet, unterliegen das verläßliche und reproduzierbare Grading und Staging von Urothelkarzinomen oftmals mehr der Subjektivität und Erfahrung des Befunders als nachvollziehbaren und standardisierten Kriterien. Die Art der Biopsie- bzw. Gewebeentnahme – in den meisten Fällen durch eine Elektroresektion der Läsion – macht diese Aufgaben nicht gerade leichter. Die gleichen Problemfelder ergeben sich übrigens auch für die histologische Diagnostik intraurothelialer Veränderungen, zusätzlich kompliziert durch eine verwirrende Terminologie. Der vorliegende Artikel versucht, einige dieser diagnostisch und klinisch relevanten Kontroversen aufzugreifen und zumindest für die oben genannten Bereiche praktisch nützliche Hinweise zu geben. Ergänzt wird dieser Versuch durch eine knappe Zusammenfassung der Grundlagen und Wertigkeit der Urin- und Blasenspülzytologie, die weniger in der Primärdiagnostik als vielmehr in der Nachsorge und Überwachung von Tumorpatienten ihre sinn-volle Anwendung findet.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Planta 192 (1993), S. 118-124 
    ISSN: 1432-2048
    Keywords: Cell cycle ; Differentiation ; Flow cytometry ; Histone ; Proliferating cell nuclear antigen ; Zea
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The cell-cycle progression of germinating embryos of maize (Zea mays L.) was studied from 0 to 72 h after the start of imbibition using DNA flow cytometry on isolated nuclei, and analyses of thymidine kinase activity, histone biosynthesis and levels of proliferating cell nulcear antigen (PCNA). At the start of germination, 75% of the cells were in G1, but this population had decreased to 25% by 72 h. The concomitant increase of cells in S-phase did not occur continuously, but stepwise, indicating that during germination most of the cells enter S-phase as a partially synchronized population. Within the initial 60 h of embryo germination the cells passed through one S-phase; the start and duration of this period of replicative DNA synthesis was further substantiated by the analysis of S-phase-associated events, the biosynthesis of core histones and the enzyme activity of thymidine kinase, which both began to increase at about 12 h after the start of differentiation. Thymidine kinase fluctuated periodically during germination with a transient maximum at 30 h and a second peak at 72 h; histone biosynthesis was not detectable until 12 h after the start of germination. The levels of PCNA protein closely resembled the pattern of thymidine kinase during germination. Together with the cytometric data this allows a clear assignment of cell cycle events to different times of embryo differentiation.
    Type of Medium: Electronic Resource
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