Search results for "Microsatellite"
showing 10 items of 425 documents
Genetic variability and geographical diversity of the main Chagas' disease vector Panstrongylus megistus (Hemiptera: Triatominae) in Brazil based on …
2014
Studies were made on the ribosomal DNA intergenic region, comprising complete internal transcribed spacer (ITS)-1, 5.8S, and ITS-2 sequences, of populations of the triatomine Panstrongylus megistus, the most important vector of Chagas' disease in Brazil since Triatoma infestans eradication. Specimens were from 26 localities of Rio Grande do Sul, Santa Catarina, Paraná, São Paulo, Minas Gerais, Bahia, and Sergipe states. In total, 21 ITS-1 and 12 ITS-2 haplotypes were found. Nucleotide differences were higher in ITS-1 (3.00%) than in ITS-2 (1.33%). The intergenic region was 1,513-1,522-bp-long (mean 1,516.9 bp), providing 26 combined haplotypes. The combination of microsatellites found in bo…
In vitro anther culture of sweet orange (Citrus sinensis L. Osbeck) genotypes and of a C. clementina × C. sinensis 'Hamlin' hybrid
2014
Citrus, and particularly sweet oranges, are very recalcitrant to anther culture. In this paper it was evaluated for the first time the response of 27 genotypes of Citrus sinensis and of one hybrid C. clementina × C. sinensis, to in vitro anther culture. Ten genotypes of sweet oranges showed embryogenic callus induction, mostly blood sweet oranges genotypes, such as Tarocco, Moro and Sanguinelli. In vitro microspore developmental switches from the gamethophytic to the sporophytic pathway were shown by DAPI staining in microspores of these responsive genotypes, after 10 months in culture. However, microsatellite marker analyses showed that these calli were heterozygous. The flow-cytometric an…
Differential Greek and northern African migrations to Sicily are supported by genetic evidence from the Y chromosome
2009
The presence or absence of genetic heterogeneity in Sicily has long been debated. Through the analysis of the variation of Y-chromosome lineages, using the combination of haplogroups and short tandem repeats from several areas of Sicily, we show that traces of genetic flows occurred in the island, due to ancient Greek colonization and to northern African contributions, are still visible on the basis of the distribution of some lineages. The genetic contribution of Greek chromosomes to the Sicilian gene pool is estimated to be about 37% whereas the contribution of North African populations is estimated to be around 6%. In particular, the presence of a modal haplotype coming from the southern…
Low effective population sizes and limited connectivity inxerothermic beetles: implications for the conservation ofan endangered habita
2014
Fragmentation and isolation may have detrimental effects on the viability of populations. Xerothermic grasslands, which are extra-zonal analogues of steppes, are among Europe's most endangered natural environments. Information about connectivity between the remaining habitat patches is critical for effective conservation planning. However, very little is known about the actual levels of isolation of individual xerothermic patches at the inter-regional and local scale. In this study, 16 microsatellite loci were used to investigate genetic diversity, structuring, effective sizes (Ne), and connectivity among populations of the weevil Centricnemus leucogrammus at various geographic scales. Anal…
Hypermethylator phenotype in sporadic colon cancer: study on a population-based series of 582 cases.
2008
Abstract The CpG island methylator phenotype (CIMP) is a distinct phenotype in colorectal cancer, associated with specific clinical, pathologic, and molecular features. However, most of the studies stratified methylation according to two subgroups (CIMP-High versus No-CIMP/CIMP-Low). In our study, we defined three different subgroups of methylation (No-CIMP, CIMP-Low, and CIMP-High) and evaluated the prognostic significance of methylation status on a population-based series of sporadic colon cancers. A total of 582 colon adenocarcinomas were evaluated using methylation-specific PCR for 5 markers (hMLH1, P16, MINT1, MINT2, and MINT31). No-CIMP status was defined as no methylated locus, CIMP-…
Interassay and interobserver comparability study of four programmed death-ligand 1 (PD-L1) immunohistochemistry assays in triple-negative breast canc…
2021
Different immunohistochemical programmed death-ligand 1 (PD-L1) assays and scorings have been reported to yield variable results in triple-negative breast cancer (TNBC). We compared the analytical concordance and reproducibility of four clinically relevant PD-L1 assays assessing immune cell (IC) score, tumor proportion score (TPS), and combined positive score (CPS) in TNBC. Primary TNBC resection specimens (n = 104) were stained for PD-L1 using VENTANA SP142, VENTANA SP263, DAKO 22C3, and DAKO 28–8. PD-L1 expression was scored according to guidelines on virtual whole slide images by four trained readers. The mean PD-L1 positivity at IC-score ≥1% and CPS ≥1 ranged between 53% and 75% with th…
High miR-21 expression from FFPE tissues is associated with poor survival and response to adjuvant chemotherapy in colon cancer
2013
Colon cancer (CC) is a leading cause of cancer mortality. Novel biomarkers are needed to identify CC patients at high risk of recurrence and those who may benefit from therapeutic intervention. The aim of this study is to investigate if miR-21 expression from RNA isolated from formalin-fixed paraffin-embedded (FFPE) tissue sections is associated with prognosis and therapeutic outcome for patients with CC. The expression of miR-21 was measured by quantitative reverse transcriptase-polymerase chain reaction in a Japanese cohort (stage I-IV, n = 156) and a German cohort (stage II, n = 145). High miR-21 expression in tumors was associated with poor survival in both the stage II/III Japanese (p …
How we treat metastatic colorectal cancer.
2020
Colorectal cancer is the second leading cause of cancer-related death worldwide. About 20% of patients suffer from metastatic disease at diagnosis, while about one-third of patients treated with curative intent relapsed. In these patients, an accurate staging allows to plan a treatment strategy within a multidisciplinary team in order to achieve predefined goals. Patient's clinical features, tumour characteristics and molecular profile (RAS/BRAF and microsatellite instability (MSI) status) should be considered during the treatment choice. Combination of chemotherapy (fluoropyrimidines, oxaliplatin and irinotecan) plus biological agents (antiepidermal growth factor receptor or antiangiogenic…
Assessing molecular subtypes of gastric cancer: microsatellite unstable and Epstein-Barr virus subtypes. Methods for detection and clinical and patho…
2018
Background The molecular classification of gastric cancer recognises two subtypes prone to immune checkpoint blockade: the microsatellite unstable and the Epstein-Barr virus (EBV)-related tumours. We aim to assess the concordance between immunohistochemistry and PCR for microsatellite status evaluation, and explore the value of microsatellite instability (MSI) and EBV as predictive survival factors. Material and methods We collected 246 consecutively diagnosed gastric cancer cases in all stages and evaluated the microsatellite status using immunohistochemistry for mismatched repair (MMR) proteins and PCR. EBV expression was studied through in situ hybridisation. Results Forty-five (18%) cas…
In the literature: October 2020.
2020
Immune checkpoint inhibitors are widely used as treatment for an increasing number of solid tumours. Nevertheless, the lack of predictive biomarker represents a limitation across several cancer types. During the last years, the possibility to dynamically study tumour evolution through circulating tumour DNA (ctDNA) in plasma has opened novel possibility in evaluating disease status and therapeutic response, especially in localised disease to predict the possibility of relapse. However, the specific opportunities for application in the context of immunotherapy remain to be clarified.1 In an article recently published in Cancer Discovery by Zhang et al ,2 a comprehensive analysis of ctDNA dat…