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Cytogenetic patterns from primary short-term culture of breast cancer, renal carcinoma, and tumors of the central nervous system are presented to illustrate the range of karyotypic diversity of human solid tumors as well as their biologic differences in culture systems that support their growth. These studies have illustrated several major issues. 1) Results vary with the tissue of origin: primary cultures from breast are almost uniformly diploid, while renal tumors are near-diploid, mosaic, and show clonal aberrations; and CNS tumors are heterogeneous: some diploid, some near-diploid and some highly aneuploid. 2) Results after short-term culture are selective, representing subpopulations from the heterogeneous cells that are detected on direct analysis of fresh tumors by cytogenetics or flow cytometry (FCM). It is not yet clear whether prognosis depends on the dominant population of the primary tumor or alternatively should be influenced by detection of small aneuploid subpopulations. 3) Evidence from all three tumor types supports the interpretation that cytogenetically normal diploid cells constitute part of some tumor populations, and may be better adapted to routine growth in culture than aneuploid subpopulations from the same primary tumors. These cells may also compose a major portion of the viable population of tumors in vivo and, therefore, could represent a useful model for studies of tumorigenesis and therapeutic regimens. 相似文献
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Phytotoxins from Alternaria helianthi: radicinin,and the structures of deoxyradicinol and radianthin
A novel compound, radianthin, with phytotoxic activity was isolated from liquid cultures of Alternaria helianthi and identified as a pyrone related to radicinin. A second metabolite was identified as radicinin itself while deoxyradicinol is described for the first time as a natural product. 相似文献
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The role of nerve lysosomal enzymes in the pathogenesis of denervation atrophy. Electromyographic and histochemical study in rats 总被引:1,自引:0,他引:1
Section of sciatic nerves of rats produced fibrillations within 3 days. Foci of hyalination leading to necrosis corresponded to segments of muscles containing end plates. The electrolyte content, mainly Ca, was increased, NADH2-TR activity was decreased and membrane ATP-ase was increased. The known increase in hydrolytic enzyme activities in denervated muscles was due to spilling of lysosomal enzymes from degenerating axons at the myoneural junction. This explains the discrepancy between morphological studies indicating paucity of lysosomes in normal muscles and the high hydrolytic enzyme activities in denervation. We propose that denervation changes are at least partly due to the effect of lysosomal spillage from degenerating axons. 相似文献
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The apical cells of Sphacelaria tribuloides Menegh. are larger than other thallus cells, contain more organelles and appear polarized. Their tip portion, where they grow, contains a well developed Golgi apparatus, abundant endoplasmic reticulum (ER) membranes, mitochondria, chloroplasts and a large number of small vacuoles. It seems likely that a continuous flow of membranous material from the ER membranes to the dictyosomes and from the latter to the plasmalemma of the extending tip portion takes place. In contrast, the basal pole possesses fewer organelles and is occupied mainly by large-sized, sometimes central vacuoles. The apical cells undergo two distinct types of highly asymmetrical differential divisions giving rise to cells of the thallus and hair initials. During the early stages of mitosis the nuclear envelope remains intact, except for fenestrated poles. Microtubules pass through the fenestrae into the nucleoplasm. During meta-phase, a typical chromosome plate is organized. The sites of attachment of spindle microtubules to the chromosomes are structurally different from the rest of the chromosomes. At late anaphase, the nuclear envelope breaks down completely. During telophase, a new membrane encloses the chromosomes which are decondensed and the nucleoli are reorganized. Cytokinesis proceeds long after mitosis at a stage in which the nuclei have increased in size and have moved farther apart. A membranous furrow develops centripetally, without the participation of microtubules. However, microtubules traverse the thin cytoplasmic strands which, in both interphase and cytokinetic cells, meander among the vacuoles of the basal pole of the cell and the internuclear space. Dictyosomes appear to be involved in the subsequent wall deposition. 相似文献
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Summary The properties of agglutination by plant lectins, along with chromosome patterns, were examined in a variety of mammalian
cell types. Untransformed adult and embryonic cells in culture, direct mouse spleen cell preparations, SV40-transformed 3T3
cells, and trypsinized 3T3 cells were all highly agglutinable with concanavalin A and with wheat germ agglutinin. In contrast,
untreated cells of the contact-inhibited 3T3 line were alone among the cells tested in their low agglutinability. Chromosome
analysis of the cultured cells showed that karyotypic variation from the diploid to an aneuploid state in mouse and rat embryo
cultures was not accompanied by a change in agglutinability. Adult rat lung, adult monkey kidney, and embryonic human lung
cells, which were all highly agglutinable, showed the normal diploid pattern. Thus, agglutination of cells by plant lectins
appears to be a cellular property often associated with non-neo-plastic cells.
This investigation was supported by Grants CA-12503 and ES-00260 from the National Institutes of Health, United States Public
Health Service. 相似文献
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Summary Experiments done with Congo red crystals and with Congo red deposits polished in a single direction by a glass wheel have shown that the appearance of green polarization color primarily depends on near-perfect parallel alignment of the dye particles. The green polarization color was seen only in the deposits which showed a clear transition from red to colorless when examined for dichroism. Another factor was found to be the thickness of the object, as the green polarization color was not present in too thick or too thin sections of amyloid-containing tissues stained with Congo red.The phenomena can be explained by the assumption that the green polarization color is due to interference between the red ray and the red component of the white ray whenever the retardation by the object approximates half the wavelength of red light.The findings indicate that amyloid differs from other materials which are stained by Congo red in that amyloid deposits bind the dye molecules in a more orderly and parallel fashion. It is suggested that minimal amounts of amyloid which are not visible in Congo red stained sections with ordinary light microscopy and which do not give the green polarization color can best be detected by examination for dichroism in ultraviolet light after having been stained with fluorescent dyes. 相似文献
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