Search results for "mitos"
showing 10 items of 190 documents
Regulation of cell cycle transcription factor Swi5 by karyopherin Msn5
2012
AbstractInactivation of S. cerevisiae β-karyopherin Msn5 causes hypersensitivity to the overexpression of mitotic cyclin Clb2 and aggravates growth defects of many mutant strains in mitotic exit, suggesting a connection between Msn5 and mitotic exit. We determined that Msn5 controlled subcellular localization of the mitotic exit transcription factor Swi5, since it was required for Swi5 nuclear export. Msn5 physically interacted with the N-terminal end of Swi5. Inactivation of Msn5 caused a severe reduction in cellular levels of Swi5 protein. This effect occurred by a post-transcriptional mechanism, since SWI5 mRNA levels were not affected. The reduced amount of Swi5 in msn5 mutant cells was…
A temperature-type model for describing the relationship between fungal growth and water activity
2001
Growth of Penicillium chrysogenum, Aspergillus flavus, Cladosporium cladosporioides and Alternaria alternata at their respective optimum temperatures was studied in Potato Dextrose Agar (PDA) medium at different water activities (a(w)) adjusted with glycerol. The growth rate (mu) was expressed as the increase in colony radius per unit of time. This paper extends the model that showed the relationship between temperature and bacterial growth rate developed by Rosso et al. [J. Theor. Biol. 162 (1993) 447] to describe the influence of a(w) on fungal development. An excellent correlation between the experimental data and the model predictions was obtained, the regression coefficients (r2) were …
Species-specific aggregation factor in sponges V. Influence on programmed syntheses
1976
Isolated cells from the siliceous sponge Geodia cydonium as well as small primary aggregates (diameter: 70 mum) consisting of them show no increase in rates of programmed syntheses and mitotic activity with time. After addition of a highly purified aggregation factor to a culture with primary aggregates which subsequently form secondary aggregates (diameter: larger than 1000 mum), a dramatic increase of DNA, RNA and protein synthesis occurs. Together with this increase, the cells show a high mitotic activity. The values for the mitotic coefficient reach a first maximum 8 h after the beginning of the secondary aggregation process. The stimulation of the mitotic activity of cells during the a…
Alterations of Activities of Ribonucleases and Polyadenylate Polymerase in Synchronized Mouse L Cells
1977
The activities of the three known catabolic and the one anabolic polyadenylate enzymes have been determined in synchronized L5178y cells: endoribonuclease, exoribonuclease, 5'-nucleotidase and poly(A) polymerase (Mg2+-dependent). These four enzymes were found primarily in the nuclear fraction. The activity of poly(A) polymerase remains essentially constant during the transition from G1 to S phase. However, the poly(A) catabolic enzyme activities increase parallel with DNA synthesis; the endoribonuclease activity increases 4-fold during G1 to S phase, the exoribonuclease and the nucleotidase activities increasing 30-fold and 16-fold. During the S phase the poly(A)-degrading enzymes are far m…
Constitutive hsp70 is essential to mitosis during early cleavage of Paracentrotus lividus embryos: The blockage of constitutive hsp70 impairs mitosis
1999
Localization of constitutive hsp70 in eggs and early embryos of sea urchin Paracentrotus lividus is shown by means of in situ immunostaining. An accumulation of this protein is shown in the mitotic structures (asters, spindles and centrosomes). Microinjection of anti-hsp70 antibodies into eggs causes impairment of formation of mitotic structures and of cell division. This impairment goes from a complete mitotic block, to irregular mitotic apparatus formation with irregular cleavage, depending upon the antibody concentration. The localization of hsp70 after antibody microinjection is also described. Blockage of mitotic apparatus formation by nocodazole also blocks the concentration of hsp70 …
De novo formation of cytokeratin filament networks originates from the cell cortex in A-431 cells
2001
Of the three major cytoskeletal filament systems, the intermediate filaments are the least understood. Since they differ fundamentally from the actin- and microtubulebased networks by their lack of polarity, it has remained a mystery how and where these principally endless filaments are formed. Using a recently established epithelial cell system in which fluorescently labeled intermediate filaments of the cytokeratin type can be monitored in living cells, we address these issues. By multidimensional time-lapse fluorescence microscopy, we examine de novo intermediate filament network formation from non-filamentous material at the end of mitosis and show that it mirrors disassembly. It is dem…
Synthesis of 5H-pyrido[3,2-b]pyrrolizin-5-one tripentone analogs with antitumor activity
2018
Abstract Pyrrolizinones represent an interesting class of compounds with varied degrees of structural complexity and pharmacological activity. Among these, 9H-pyrido[2,3-b]pyrrolizin-9-one, tripentone analogs, recently reported by us, showed significant antiproliferative activity against human tumor cell lines, inducing apoptosis and not affecting viability of Caco-2 differentiated in normal intestinal-like cells. Considering their interesting biological activity, their 5H-pyrido[3,2-b]pyrrolizin-5-one analogs were efficiently synthesized in good to excellent yields (61–91%). All tripentone derivatives were tested to assess their cytotoxicity against two human tumor cell lines, HCT-116 (hum…
The relation between tumor cell proliferation and vascularization in differentiated and undifferentiated colon carcinomas in the rat.
1982
Tumor cell proliferation and tumor vascularization were investigated in differentiated and undifferentiated colon carcinomas of the rat. The following results were found: 1, in both tumor types, vascularization is developed equally well; 2, both in the differentiated and in the undifferentiated carcinomas, the number of proliferating tumor cells decreases with increasing distance from the capillaries; at a distance of about 80 microns, there is no longer any noteworthy tumor cell proliferation; 3, the differentiated and undifferentiated carcinomas differ both in the level of the mitosis index and 3H-thymidine labeling index as well as in their local proliferation pattern despite equal vascu…
Tras las huellas de (La) Malinche. Tránsito del arquetipo en el teatro mexicano de la segunda mitad del siglo XX
2015
El objeto de la presente tesis es el análisis estético e ideológico de la evolución del arquetipo La Malinche (personaje dramático e histórico y mito femenino cuyo origen está en la crónica de la Conquista de México), en la tradición dramática mexicana de la segunda mitad del siglo XX, a través de una selección de obras y una puesta en escena que dan cuenta de su cabal transformación en el imaginario. Se inserta pues dentro de las investigaciones estéticas y literarias, sociológicas y de género que desde los años 80, tratan de adentrarse en el estudio del personaje en relación a distintas líneas de pensamiento crítico del México presente. El trabajo desarrolla y profundiza en la transformac…
China y el Lejano Oriente en el relato de Benjamín de Tudela (siglo xii). Realidades y fantasías
2018
El texto hebreo del relato de los viajes e itinerarios del rabino Benjamín de Tudela (siglo xii, circa 1165-1173) contiene interesantes y curiosos datos étnicos, geográficos, económicos y míticos relacionados con remotas latitudes orientales: las tradicionales rutas comerciales centroasiáticas, la India, Malabar, Tíbet y la China, entre otros parajes. Informaciones reales o fantásticas que acaso debió recoger y anotar el judío tudelano durante su larga estancia en Bagdad, o fruto de posteriores interpolaciones y añadidos a cargo de los copistas.