Search results for "Ploidy"

Preimplantation genetic diagnosis by fluorescence in situ hybridization: clinical possibilities and pitfalls.

2003

Preimplantation genetic diagnosis using the fluorescence in situ hybridization technique (FISH) is being used widely to prevent the transmission of sex-linked diseases, to screen for translocations, and for aneuploidy screenng in specific invitro fertilization (IVF) patient groups, along with FISH analysis of spematozoa in intertile men. In this study, we aim to critically analyze our clinical results in patients at risk of transmitting sex-linked diseases (n = 55), in carriers of translocations (n = 43), in women who have recurent miscarriage (two or more miscarriages) (n = 128), recurrent IVF failure (three or more failed IVF attempts) (n = 47), and patients of advanced maternal age (37 y…

Impact of chromosomal abnormalities on preimplantation embryo development.

2007

Objectives To evaluate the influence of numerical chromosomal abnormalities on preimplantation embryo development. Methods This study includes 6936 embryos from 1245 women undergoing preimplantation genetic diagnosis (PGD). Indications for aneuploidy screening were: recurrent miscarriages, implantation failure, severe male factor, advanced maternal age, and mixed causes. Embryo biopsy was performed on day 3, and embryos were co-cultured until day 5, when embryo transfer was performed. Results In the aneuploidy screening regimen, normal euploid embryos showed significantly higher blastocyst rates (68.2%) compared to chromosomally abnormal (42.8%, p < 0.0001) and mosaic (53.7%, p < 0.0001) em…

Cytogenetics, flow cytometry, cytophotometry and morphometry of 22 cases of primary breast carcinoma. A comparative study.

1992

Cytogenetic, flow cytometric, cytophotometric and morphometric analyses were performed on 22 previously untreated, primary solid breast carcinomas. Although the cell nuclei as the primary object of these studies were the same in all the tumors, distinct features were evaluated in each case to determine to what degree the results obtained by these techniques are comparable. From the cytogenetic viewpoint, six tumors had a modal number in the diploid range, seven were in the triploid range, and two in the tetraploid range; seven tumors had no modal number. These data correlate with the flow cytometry and cytophotometry results obtained, with DNA values slightly higher than their respective ch…

Characterization of an epithelial, nearly diploid liver cell strain, from Chinese hamster, able to activate promutagens

1987

Epithelial liver cells of the Chinese hamster (CHEL cells) were propagated in culture for 35 passages. At favourable cell densities, the population doubling time in normal medium, was 20 h. L-Tyrosine amino transferase activity was retained at a measurable level, but its enhancement by dexamethasone was detected solely in cells of early passages. Pyruvate kinase was strongly activated by fructose-1,6-biphosphate at low substrate concentrations. These enzymatic properties suggest that the CHEL cells are derived from a sub-population of parenchymal hepatocytes or from cells closely related to parenchymal hepatocytes. With a lag period of a few hours, CHEL cultures metabolized benzo[a]pyrene. …

Is triploidy indisputably determinable in hybridogenetic hybrids by planimetric analyses of erythrocytes?

2008

The size of amphibian erythrocytes is positively correlated to their DNA content. Therefore, planimetry of erythrocytes has long been used to determine ploidy levels in amphibians. In Rana esculenta. a hybrid originating from Rana ridibunda x Rana lessonae natural crosses, planimetric determination of erythrocyte size is used to distinguish diploid and triploid specimen. In the present study we performed planimetric analyses on the hybrid Rana grafi, comprising a second hybridogenetic system with its parental species Rana ridibunda and Rana perezi in southern parts of France. We found size differences of diploid and triploid erythrocytes to range between 26 and 33% in studies on adult R. es…

Effect of environmental endocrine disruptor's exposure on sperm quality and aneuploidy rates in fertile sperm donors

2016

How many single embryo transfers would be needed to perform an euploid embryo transfer according to the age of the patient?

2019

DNA MICROARRAY AND BIOINFORMATICS AS TOOLS TO IDENTIFY A COMMON MOLECULAR SIGNATURE SHARED BY HUMAN ANEUPLOID CELLS

Genomic instability is a hallmark of the majority of human tumors explaining the heterogeneity shown by tumor cells. This phenomenon is often associated with chromosomal instability (CIN) and aneuploidy, a condition in which tumor cells lose or gain chromosomes. Previously, we showed that posttranscriptional silencing by RNAi of pRb(1), DNMT1(2) and MAD2(3) is associated with aneuploidy in cultured human cells reinforcing the idea that there are several roads leading to aneuploidy. In the attempt to understand if a common molecular signature exists that underlies aneuploidy and its tolerance in tumor cells, we did post transcriptional silencing of Rb, MAD2 and DNMT1 in human fibroblasts (IM…

Aneuploidy induced by MAD2 haploinsufficiency triggers premature senescence in human primary fibroblast

2009

Chromosomes of the Parasitic Isopod Anilocra Physodes

1996

AbstractCounts of mitotic chromosomes have allowed to determine 2n = 12 as the modal diploid number of Anilocra physodes. Application of the C-banding technique reveals that two hetero-chromatic blocks bordering the centromeric region occur in each chromosome. This supports the notion that the actual low chromosome number of A. physodes may have been derived through a process of Robertsonian fusion.