Search results for "ploidie"

Hybridization, ecogeographical displacement and the emergence of new lineages – A genotyping‐by‐sequencing and ecological niche and species distribut…

2021

Ecogeographical displacement of homoploid hybrid lineages from their parents is well documented and considered an important mechanism to achieve reproductive isolation. In this study, we investigated the origin of the flowering plant species Sempervivum tectorum in the Massif Central (France) through homoploid hybridization between lineages of the species from the Rhine Gorge area (Germany) and the Pyrenees (France). We used genotyping-by-sequencing genetic data as evidence for the hybrid origin of the Massif Central lineage, and WorldClim climatic data and soil pH and soil temperature data collected by us for ecological niche and species distribution modelling. We could show that the Massi…

DNA demethylation caused By 5-Aza-2'-Deoxycytidine induces mitotic alterations and aneuploidy

2016

Aneuploidy, the unbalanced number of chromosomes in a cell, is considered a prevalent form of genetic instability and is largely acknowledged as a condition implicated in tumorigenesis. Epigenetic alterations like DNA hypomethylation have been correlated with cancer initiation/progression. Furthermore, a growing body of evidence suggests the involvement of epigenome-wide disruption as a cause of global DNA hypomethylation in aneuploidy generation. Here, we report that the DNA hypomethylating drug 5-aza-2′-deoxycytidine (DAC), affects the correct ploidy of nearly diploid HCT-116 human cells by altering the methylation pattern of the chromosomes. Specifically, we show that a DAC-induced reduc…

Rescuing monopronucleated-derived human blastocysts: a model to study chromosomal topography and fingerprinting.

2021

Objective To quantify the percentage of monopronuclear-derived blastocysts (MNBs) that are potentially useful for reproductive purposes using classic and state-of-the-art chromosome analysis approaches, and to study chromosomal distribution in the inner cell mass (ICM) and trophectoderm (TE) for intertissue/intratissue concordance comparison. Design Prospective experimental study. Setting Single-center in vitro fertilization clinic and reproductive genetics laboratory. Patient(s) A total of 1,128 monopronuclear zygotes were obtained between June 2016 and December 2018. Intervention(s) MNBs were whole-fixed or biopsied to obtain a portion of ICM and 2 TE portions (TE1 and TE2) and were subse…

Assessment of embryo morphology and developmental dynamics by time-lapse microscopy: is there a relation to implantation and ploidy?

2017

Time-lapse microscopy (TLM) is an exciting novel technology with great potential for enhancing embryo selection in the embryology laboratory. This non-invasive objective assessment of embryos has provided a new tool for predicting embryo development and implantation potential. TLM detects several morphological phenomena that are often missed with static observations using conventional incubators, such as irregular divisions, blastocyst collapse and re-expansion, timing of blastocoel appearance, and timing of formation and internalization of fragments. Nevertheless, it should be recognized that conventional morphological assessment has been widely accepted as the gold standard by most embryo…

To invade, or to observe, that is the question

2018

Value of Quantitative DNA Analysis in Endocrine Tumors of the Pancreas

1997

The diagnosis of malignancy can be difficult in endocrine tumors of the pancreas. Moreover prognostically relevant factors are not available. The aim of this study was to evaluate retrospectively whether the DNA distribution pattern can differentiate between benign and malignant pancreatic endocrine tumors and secondly whether the DNA content of tumor cells gives prognostic information.Image cytometry of paraffin-embedded tumor material of 42 pancreatic endocrine tumors.In 27 benign endocrine pancreatic tumors (25 insulinomas, 2 benign nonfunctioning endocrine tumors) we could differentiate between 6 diploid, 15 hypotriploid and 6 triploid DNA histograms. In 15 malignant endocrine tumors of…

Biological parameters in breast cancer.

1996

Prospective, blinded comparison of cytology and DNA-image cytometry of brush biopsies for early detection of oral malignancy

2012

summary Objectives: Adjunctive techniques like DNA image cytometry (DNA-ICM) have been attributed to enhance the diagnostic performance of oral brush biopsies. The aim of the study was an evaluation of brush biopsies, analysed according to morphological criteria and by DNA-ICM vs. histological findings in a blinded prospective trial. Materials and methods: Eighty eight brush biopsies of 70 patients were sampled. Only clinical suspicious but not evident malignant oral lesions were included. Clinical diagnosis was leukoplakia (n = 36), lichen planus (n = 18), verruciform erythroplakia (n = 12), erythroleukoplakia (n = 9), erosion (n = 7) and induration (n = 6). Evaluation was conducted via hi…

Evaluation of DNA ploidy and degree of DNA abnormality in benign and malignant melanocytic lesions of the skin using video imaging.

2000

BACKGROUND Making a morphologic distinction between benign and malignant melanocytic tumors of the skin is frequently difficult, especially because “gray zones” between these lesions often exist. DNA image cytometry as an adjuvant method for the diagnosis and prognostic prediction of premalignant lesions and malignant tumors of many other organs is already well established. The aim of this study was to determine whether DNA image cytometry is helpful in distinguishing benign from malignant melanocytic lesions and whether cytometry would give valid information with which to predict the prognoses associated with malignant melanomas. METHODS DNA image cytometry was performed on 127 benign and …

Proliferative Activity and Cytometric Characteristics in Polyps of the Nasal Cavity and Paranasal Sinuses

2000

Although several investigations have revealed the influence of cytokines, allergy, and environmental factors in polyp development, the etiology of nasal polyps is still unknown. To estimate the biology of this common disease the operative specimens of 50 patients who underwent surgery for polyps of the nasal cavity and the paranasal sinuses were examined; of these, 10 patients had recurrent disease and 23 patients had an allergy. The investigations included routine histology and quantitative DNA measurements, along with immunohistochemical identification of proliferation markers (i.e., MIB-1; proliferating cell nuclear antigen, PCNA). Histologically, most polyps revealed an infiltration wi…