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  • Stomach  (2)
  • 36.00  (1)
  • 3H-thymidine autoradiography  (1)
  • 1
    ISSN: 1432-1335
    Keywords: Stomach ; Signet ring cell carcinoma ; Cell turnover ; Tritiated thymidine autoradiography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Signet ring cell carcinoma was induced in canine stomachs by N-ethyl-N′-nitro-N-nitrosoguanidine, and modes of cell proliferation and turnover in the carcinoma were studied by 3H-thymidine autoradiography in conjunction with morphometric analysis. From 2 to 15 months after the cessation of 8 months carcinogen treatment, carcinomas in an early stage were obtained. Most of the cancer tissues confined to the lamina propria showed a layered structure. This comprised three layers; the superficial and the deep layer were composed of signet ring cells, and the middle layer was composed of small round cells. The dogs were labeled with 3H-thymidine by s.c. injection and by local infusion of the celiac artery. Flash-labeled autoradiographs revealed that most 3H-thymidine incorporating cancer cells were located around the middle layer, with a small amount of mucin. Using a pulse labeling experiment, those labeled carcinoma cells were shown to migrate from the middle layer towards the surface. Morphometric analysis of the autoradiographs showed that the small cells in the middle layer migrated upwards and produced mucin to become full-blown signet ring cells by 5.5 days. In 15 days, most labeled cancer cells in the superficial layer had disappeared. This mode of cellular turnover appeared to mimic a cell renewal system of the normal gastric mucosa. If the cancer cells turn over in this way, the tumor must grow slowly, remaining as an intramucosal cancer for a relatively long period.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1432-1335
    Keywords: Stomach ; Signet-ring-cell carcinoma ; Cell kinetics ; Bromodeoxyuridine ; N-ethyl-N′-nitro-N-nitrosoguanidine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Signet-ring-cell carcinomas were induced in the stomach of 12 beagle dogs by p.o. administration ofN-ethyl-N′-nitro-N-nitrosoguanidine (ENNG), and the morphology and modes of cell proliferation in an incipient stage of cancer growth were studied with bromodeoxyuridine (BrdUrd) incorporation. From 5 to 27 months after the completion of 8 months' carcinogen treatment, minute carcinomas were found in the stomachs of 9 dogs. Before sacrifice, the dogs were given a single or repeated i.v. injections of BrdUrd for 1–3 days. Minute signet-ring-cell carcinomas were found to form a layered structure, in which the cancer cells proliferated in the lamina propria at the gland-neck level and differentiated to postmitotic signet-ring cells at the upper and lower levels of the mucosa. From repeated injections of BrdUrd, the time required for all the proliferative cells to be labelled with BrdUrd (reflecting the maximum cellcycle time) was estimated to be 1.7 days for the normal glands, and 2.7 days for minute signet-ring-cell carcinomas. From the labelling index with BrdUrd as well as from the morphology, earliest carcinomas were identified in the single gland. There remained atrophic normal epithelium commonly in the single-gland lesions. Proliferative atypical cells appeared to be shed into the stroma passively through the atrophy and subsequent collapse of the gland rather than through active invasion. This may be a reason why cancer cells in minute signet-ring cell carcinomas preserved the normal pattern of cell renewal movement to form the layered structure.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 1432-0649
    Keywords: 36.00 ; 42.65 ; 42.80
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract A convenient technique for the ultrashort-relaxation-time measurement using temporally incoherent light instead of short pulses can be applied to the studies of relaxation processes. Theoretical studies on measuring various types of relaxation times by this method are summarized. We have applied this technique to the studies of the electronic dephasing in a polydiacetylene film, the vibrational dephasing in dimethylsulfoxide and the relaxation of optical Kerr effect in CS2 and nitrobenzene.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 172 (1976), S. 171-184 
    ISSN: 1432-0878
    Keywords: Gastric gland (Golden hamster) ; Cellular migration ; 3H-thymidine autoradiography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Ten hamsters received repeated injections of 3H-thymidine for 4 days and were allowed to survive for 7, 28, 42 and 100 days. Changes in spatial distribution of the labelled cells and in labelling indices of each cell line in the gastric glands were studied at various days after 3H-thymidine injections, and the fate of the mucous neck cell, the replacement of the chief cell and the mode of cell migration were discussed. After 4 days of repeated injections of 3H-thymidine, the labelled parietal cells and the mucous neck cells were concentrated at the neck area. Starting from the neck area, they migrated an average of 3 micra downwards per day. By 42 days, they reached the middle level of the glands, where the labelled mucous neck cells decreased but the labelled chief cells increased in number. The differentiation of the chief cell then appears to take place at the middle level of the glands through transformation of the migratory mucous neck cells. After 4 days of the labelling, about 1.8% of the chief cells located in the lower part of the glands was found to undergo in situ replication. This indicates that the renewal of this cell type is partly assured by its own mitotic activity. The foveolar cell — the future surface epithelium — seems to migrate upwards along the long axis of the glandular tubule in the pipe line system, which means “first produced, first migrates”. After migrating out from the neck area, the parietal cell and the mucous neck cell (the future chief cell) take an average of 200 days to reach the lower end of the glands. In the process of migration, however, the cells produced contemporaneously at the neck area became scatteringly spread from the neck towards the bottom of the gland. The time required for the newly-formed cells to reach the lower end of the gland varied between 100 and 300 days. In the gastric glands the cells first produced at the neck area do not first reach the lower end of the glands. This mode of random migration is referred to as the “stochastic flow system”. As one of the probable factors which disturb the pipe line flow of downward cell migration, cellular movements perpendicular to the long axis of the glandular tubule were suggested to occur at random at an any level of the gastric glands.
    Type of Medium: Electronic Resource
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