Search results for "mitosi"
showing 10 items of 158 documents
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…
Conocimiento pedagógico del contenido para la enseñanza del tema mitosis: un estudio de casos con docentes universitarios de Argentina
2015
The pedagogical content knowledge (PCK) for teaching mitosis at university isan unexplored field. We report the characterization of university teachers’ PCK on mitosisemploying the Content Representation questionnaire (CoRe) and Professional and Pedagogicalexperience Repertoire (PaP-eR). The differences found in the teachers’ CDC are consistent withthe characteristics of this construct: it is specific to a topic, a teacher and a context. The PCKdevelopment of university teachers in the context of teaching centered on the transmissionof knowledge emerges as a possible strategy to reorient the teaching of mitosis to approachesbased on the construction of scaffoldings that facilitate student l…
PML nuclear body-residing proteins sequentially associate with HPV genome after infectious nuclear delivery.
2019
Subnuclear promyelocytic leukemia (PML) nuclear bodies (NBs) are targeted by many DNA viruses after nuclear delivery. PML protein is essential for formation of PML NBs. Sp100 and Small Ubiquitin-Like Modifier (SUMO) are also permanently residing within PML NBs. Often, large DNA viruses disassemble and reorganize PML NBs to counteract their intrinsic antiviral activity and support establishment of infection. However, human papillomavirus (HPV) requires PML protein to retain incoming viral DNA in the nucleus for subsequent efficient transcription. In contrast, Sp100 was identified as a restriction factor for HPV. These findings suggested that PML NBs are important regulators of early stages o…
Prediction model for aneuploidy in early human embryo development revealed by single-cell analysis.
2014
Aneuploidies are prevalent in the human embryo and impair proper development, leading to cell cycle arrest. Recent advances in imaging and molecular and genetic analyses are postulated as promising strategies to unveil the mechanisms involved in aneuploidy generation. Here we combine time-lapse, complete chromosomal assessment and single-cell RT–qPCR to simultaneously obtain information from all cells that compose a human embryo until the approximately eight-cell stage (n=85). Our data indicate that the chromosomal status of aneuploid embryos (n=26), including those that are mosaic (n=3), correlates with significant differences in the duration of the first mitotic phase when compared with e…
The pattern of neuroblast formation, mitotic domains and proneural gene expression during early brain development in Drosophila.
2003
In the Drosophila embryo, studies on CNS development have so far mainly focused on the relatively simply structured ventral nerve cord. In the trunk, proneural genes become expressed in small cell clusters at specific positions of the ventral neuroectoderm. A lateral inhibition process mediated by the neurogenic genes ensures that only one cell within each proneural cluster delaminates as a neural stem cell (neuroblast). Thus, a fixed number of neuroblasts is formed, according to a stereotypical spatiotemporal and segmentally repeated pattern, each subsequently generating a specific cell lineage. Owing to higher complexity and hidden segmental organisation, the mechanisms underlying the dev…
Long-term response of osteogenic cells on micron and submicron-scale-structured hydrophilic titanium surfaces: sequence of cell proliferation and cel…
2010
Objective: Modifications of surface topography and surface chemistry are key factors for guiding target cells during dental implant healing. Recent in vitro studies confirmed promotion of early osteogenic cell differentiation on submicron scaled surfaces in particular when hydrophilized. However, no long-term observations on both osteogenic cell proliferation as well as on cell maturation have been reported for respectively modified surfaces. Aim of this study was to monitor osteogenic cell proliferation and expression of specific osteogenic cell differentiation markers on a protein level over an extended period of 3 weeks with respect to surface modifications. Material and methods: Modifie…
Organometallic complexes with biological molecules: V.In vivo cytotoxicity of diorganotin(IV)-amoxicillin derivatives in mitotic chromosomes ofrutilu…
1995
In order to test in vivo cytotoxicity of diorganotin(IV)-amoxicillin (amox) derivatives, mitotic chromosomes of Rutilus rubilio (Pisces, Cyprinidae) have been analyzed using two different chromosome-staining techniques. Results gathered after exposure of fish to the free amox.3H 2 O, R 2 SnClamox.2H 2 O, and R 2 Snamox 2 .2H 2 O (R = methyl, butyl and phenyl ; amox - = 6-[D(-)-β-amino-p-hydroxyphenylacetamido]penicillinate) suggest that methyl derivatives seem to exert a lower cytotoxicity than butyl and phenyl ones and that R 2 Snamox 2 .2H 2 O derivatives are more toxic than R 2 Snclamox.2H 2 O at both 10 -5 and 10 -7 mol dm -3 concentrations. The following structural lesions have been id…
Endoreduplication induced in cultured Chinese hamster cells by different anti-topoisomerase II chemicals
2005
With the ultimate purpose of testing the hypothesis that, as shown in yeast mutants, any malfunction of DNA topoisomerase II might result in aberrant mitosis due to defective chromosome segregation, we have chosen three chemicals of different nature, recently reported to catalytically inhibit the enzyme. The endpoint selected to assess any negative effect on the ability of topoisomerase II to properly carry out decatenation of fully replicated chromosomes in the G2/M phase of the cell cycle was the presence of metaphases showing diplochromosomes as a result of endoreduplication, i.e. two successive rounds of DNA replication without intervening mitosis. The anti-topoisomerase drugs selected …
Organometallic complexes with biological molecues, part 3.in vivo cytotoxicity of diorganotin (IV) chloro and triorganotin (IV) chloro derivatives of…
1994
In order to obtain a continuous source of mitotic metaphases, gill tissue of Aphaius fasciatus (Pisces, Cyprinodontiformes) has been successfully employed. Results gathered after exposure of fish to R2SnClpenG, R3SnClpenGNa, to the parents R2SnCl2, R3SnCl and to penGNa (penGNa = penicillinGNa; R = methyl, butyl and phenyl) suggest that both the parent organotin (IV) chloride and organotin (IV) chloropenG derivatives are toxic while penGNa exerts no significant toxic activity. Essentially, all of the chromosome abnormalities are classifiable as irregularly staining of chromosomes, breakages, side-arm bridges or pseudochiasmata.
Genetic and Molecular Characterization of The Human Osteosarcoma 3AB-OS Cancer Stem Cell Line: A Possible Model For Studying Osteosarcoma Origin and …
2013
Finding new treatments targeting cancer stem cells (CSCs) within a tumor seems to be critical to halt cancer and improve patient survival. Osteosarcoma is an aggressive tumor affecting adolescents, for which there is no second-line chemotherapy. Uncovering new molecular mechanisms underlying the development of osteosarcoma and origin of CSCs is crucial to identify new possible therapeutic strategies. Here, we aimed to characterize genetically and molecularly the human osteosarcoma 3AB-OS CSC line, previously selected from MG63 cells and which proved to have both in vitro and in vivo features of CSCs. Classic cytogenetic studies demonstrated that 3AB-OS cells have hypertriploid karyotype wit…