Candida Biofilms
Chaminda Jayampath Seneviratne in Microbial Biofilms, 2017
In eukaryotes, the term ‘ploidy’ refers to the number of sets of chromosomes in a biological cell [86]. Cells containing two sets of chromosomes in their genome are called diploid cells whereas those with only one set of chromosomes are called haploid cells. In the eukaryotic model organism, the budding yeast Saccharomyces cerevisiae, haploid and diploid cells are the two forms that can survive and proliferate [87]. The haploid form is the sexual form of S. cerevisiae, and haploid cells undergo a simple life cycle of mitosis and proliferation. Haploid cells of the opposite mating types can mate and generate diploid cells. S. cerevisiae haploids have a lower tolerance to unfavourable environments and tend to die under stress conditions. In contrast, the diploid cells are the asexual form of S. cerevisiae. Under certain stress conditions, diploid cells undergo sporulation, producing four haploid spores via meiosis [86].
Preimplantation Genetic Testing of Aneuploidies (PGT-A)
Carlos Simón, Carmen Rubio in Handbook of Genetic Diagnostic Technologies in Reproductive Medicine, 2022
The latest and most frequently applied approach for aneuploidy screening is next-generation sequencing (NGS). This is an umbrella term for recently developed platforms that can generate aneuploidy data from a small number of cells (e.g., from TE biopsies) and are rapid, reliable, accurate, scalable, and thus cost-effective. Most NGS protocols, analogous to aCGH, begin with WGA. Next, a barcoding step is performed with each sample being labeled with a unique identification sequence. Barcoded DNA samples from individual embryos can be pooled together, and processed simultaneously, saving both time and cost. Following sequencing, each sample is aligned to a known reference human genome. Aneuploidies and large deletions and duplications can be identified, and an automated “call” is generated regarding ploidy status at specific chromosomal regions.
Genetic analysis of the embryo
David K. Gardner, Ariel Weissman, Colin M. Howles, Zeev Shoham in Textbook of Assisted Reproductive Techniques, 2017
Successful multiplex PCR reactions enable simulta- neous assessment of numerous loci (22). Multiplex PCR reaction may include assays for specific gene defects, unique sequences of specific chromosomes, and linked- informative polymorphic markers. This allows both the analysis of the disease mutation, assessment of aneu- ploidy, and a reduction in the risk of contamination and ADO (14,15,23–26). This strategy is particularly useful for the PGD of dominant disorders, in which one primer set amplifies the region of mutation, while the other amplifies a polymorphic marker that is linked with the tested gene (24, 27). The probability of ADO affecting both the muta- tion site and the linked polymorphic site is very low, and decreases as more polymorphic markers are tested. This decreases both false-positive and false-negative results.
Hepatoprotective effect of the radiation countermeasure flagellin in the long term after irradiation of mice
Published in International Journal of Radiation Biology, 2023
Lyudmila P. Sycheva, Lev M. Rozhdestvenskii, Nina I. Lisina, Tatyana G. Shliakova, Valery V. Zorin, Kseniya Yu. Romanova
The original technique was used for cytome analysis of hepatocytes (Sycheva et al. 2020), including: fixation of liver pieces with 10% formalin for at least 1 month; dissociation of cells with 50% KOH for three hours (37 °C); washing with running water; suspension; staining with aceto-orcein for two hours (37 °C) and light green for 10 seconds (20 °C). This approach made it possible additionally to assess the cytotoxic effect of factors by ploidy and nuclearity of hepatocytes. We analyzed 1000 hepatocytes from each animal on encoded preparations (×1000 magnification). The proportion of cells 2n, (2n + 2n), 4n, (4n + 4n), ≥8n and ≥(8n + 8n) (Figure 1) was determined. Cytogenetic disorders were counted as cells with micronuclei, nuclear buds, and internuclear bridges. The ploidy index was defined as the ratio of the total number of polyploid cells to the total number of diploid cells and the nuclearity index as the ratio of the total number of binuclear cells to the total number of mononuclear cells.
Combination of aneuploidy and high S-phase fraction indicates increased risk of relapse in stage I endometrioid endometrial carcinoma
Published in Acta Oncologica, 2021
Annika Patthey, Karin Boman, Björn Tavelin, David Lindquist, Eva Lundin, Magnus Hultdin
Ploidy (i.e., DNA content in tumor cells) has been suggested as a prognostic marker where aneuploidy has been associated with worse prognosis in simple and/or multivariable analysis. However, the value of ploidy as a prognostic marker varies in different studies [7–27]. Proliferation measured by S-phase fraction (SPF) using flow cytometry has also been discussed as a prognostic marker. Still, only a few studies have shown that SPF gives prognostic information in multivariable analysis [11,12,16,20,24,26,27]. The reason for the heterogeneous outcome in different studies analyzing prognostic relevance of ploidy and SPF is unknown. However, it could be related to a number of factors: (1) low number of patients included; (2) mixture of tumors types (I and II); (3) inclusion of different FIGO stages (I–IV); (4) the chosen endpoint for the analysis (overall survival, relapse or metastasis); (5) different approaches for ploidy/SPF analysis i.e., image analysis or flow cytometry (based on fresh/frozen tumors and/or formalin fixed paraffin embedded tissue – FFPE). Large studies on more homogenous material could be useful for further analysis of the prognostic value of SFP and ploidy in endometrial carcinoma.
Discovery of novel thiosemicarbazone derivatives with potent and selective anti-Candida glabrata activity
Published in Journal of Enzyme Inhibition and Medicinal Chemistry, 2023
Xianru Li, Liping Li, Haonan Zhang, Xiaochen Chi, Yuanying Jiang, Tingjunhong Ni
Unlike C. albicans, C. glabrata always grows as unicellular yeast and also has the ability to form filamentous pseudohyphae but has lost the ability to undergo true hyphal growth7,9,10. Genome sequencing identified that C. glabrata shares a common ancestor with Saccharomyces cerevisiae rather than C. albicans7. The ploidy status of C. glabrata varies dramatically under different conditions, including the ability to switch ploidy between haploid, aneuploid, diploid, and hyper-diploid forms. Variations in ploidy, as well as morphological transitions, contribute to C. glabrata’s ability to develop antifungal resistance10. C. glabrata strains easily and quickly acquire drug resistance to azoles with some strains having intrinsic resistance to azoles11. Moreover, C. glabrata also displays high intrinsic resistance to echinocandins, and polyene-resistant clinical C. glabrata isolates are emerging12,13. Single drug and multi-drug resistance of C. glabrata is becoming increasingly prevalent and difficult to treat. Despite the fact that five classes of antifungal drugs (Figure 1) have been approved for the treatment of IFIs to date (the azoles (6), polyenes (1), flucytosine (1), echinocandins (3) and triterpenoid (1)), the current antifungal arsenal remains inadequate14. Therefore, new antifungal drugs with high potency and novel mechanisms against C. glabrata are urgently needed.
Related Knowledge Centers
- Allele
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- Polyploidy
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- Chromosome
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- Pseudoautosomal Region
- Gene