Search results for " hybridization"
showing 10 items of 715 documents
Defining Ewing and Ewing-like small round cell tumors (SRCT): The need for molecular techniques in their categorization and differential diagnosis. A…
2016
Abstract Background Differentiation of Ewing sarcoma family of tumors (ESFT) and Ewing-like tumors remains problematic. Certain ESFT with morphological and immunohistochemical (IHC) profiles lack the EWSR1-ETS transcript. To improve diagnostic accuracy we investigated the presence of several specific transcripts in 200 small round cell tumors (SRCT) displaying ESFT morphology and immunophenotype in which EWSR1 FISH analysis was non-informative or negative. Design 200 tumors (formalin-fixed, paraffin-embedded) were analyzed by RT-PCR. All tumors were tested for EWSR1-ETS , EWSR1 / WT1 , PAX3 / 7-FOX01 or SYT / SSX transcripts, and the negative tumors were subsequently analyzed for CIC / DUX4…
NF1 microdeletion syndrome: case report of two new patients
2019
Abstract Background 17q11.2 microdeletions, which include the neurofibromatosis type 1 (NF1) gene region, are responsible for the NF1 microdeletion syndrome, observed in 4.2% of all NF1 patients. Large deletions of the NF1 gene and its flanking regions are associated with a more severe NF1 phenotype than the NF1 general population. Case presentation We hereby describe the clinical and molecular features of two girls (aged 2 and 4 years, respectively), with non-mosaic atypical deletions. Patient 1 showed fifteen café-au-lait spots and axillary freckling, as well as a Lisch nodule in the left eye, strabismus, high-arched palate, malocclusion, severe kyphoscoliosis, bilateral calcaneovalgus fo…
Jacobsen syndrome and neonatal bleeding: report on two unrelated patients
2021
Abstract Introduction In 1973, Petrea Jacobsen described the first patient showing dysmorphic features, developmental delay and congenital heart disease (atrial and ventricular septal defect) associated to a 11q deletion, inherited from the father. Since then, more than 200 patients have been reported, and the chromosomal critical region responsible for this contiguous gene disorder has been identified. Patients’ presentation We report on two unrelated newborns observed in Italy affected by Jacobsen syndrome (JBS, also known as 11q23 deletion). Both patients presented prenatal and postnatal bleeding, growth and developmental delay, craniofacial dysmorphisms, multiple congenital anomalies, a…
Evolutionary insight on localization of 18S, 28S rDNA genes on homologous chromosomes in Primates genomes
2018
Abstract We explored the topology of 18S and 28S rDNA units by fluorescence in situ hybridization (FISH) in the karyotypes of thirteen species representatives from major groups of Primates and Tupaia minor (Günther, 1876) (Scandentia), in order to expand our knowledge of Primate genome reshuffling and to identify the possible dispersion mechanisms of rDNA sequences. We documented that rDNA probe signals were identified on one to six pairs of chromosomes, both acrocentric and metacentric ones. In addition, we examined the potential homology of chromosomes bearing rDNA genes across different species and in a wide phylogenetic perspective, based on the DAPI-inverted pattern and their synteny t…
The seed endosphere of Anadenanthera colubrina is inhabited by a complex microbiota, including Methylobacterium spp. and Staphylococcus spp. with pot…
2018
Background and aims: Plant seeds are emerging micro–habitats, whose importance as reservoir and vector of beneficial microbes just begins to be recognized. Here we aimed to characterize the bacterial microbiota of the Anadenanthera colubrina seed endosphere, with special focus to beneficial traits and to the colonization pattern. Methods: Cultivation–dependent (isolation from surface–sterilized seeds) and cultivation–independent (pyrosequencing of 16S rRNA gene from metagenomic seed DNA) analyses, functional tests and microscopical investigations (fluorescence in situ hybridization coupled with confocal laser scanning microscopy (FISH-CLSM) were performed. Results: We isolated several Methy…
Telomere Length Determines TERRA and R-Loop Regulation through the Cell Cycle
2017
Maintenance of a minimal telomere length is essential to prevent cellular senescence. When critically short telomeres arise in the absence of telomerase, they can be repaired by homology-directed repair (HDR) to prevent premature senescence onset. It is unclear why specifically the shortest telomeres are targeted for HDR. We demonstrate that the non-coding RNA TERRA accumulates as HDR-promoting RNA-DNA hybrids (R-loops) preferentially at very short telomeres. The increased level of TERRA and R-loops, exclusively at short telomeres, is due to a local defect in RNA degradation by the Rat1 and RNase H2 nucleases, respectively. Consequently, the coordination of TERRA degradation with telomere r…
Bacterial communities associated with the ectoparasitic mites Varroa destructor and Tropilaelaps mercedesae of the honey bee (Apis mellifera).
2017
Varroa and Tropilaelaps mites have been reported as serious ectoparasites of the honey bee (Apis mellifera). In this study, bacterial communities associated with Varroa destructor and Tropilaelaps mercedesae from northern Thailand were determined, using both culture-dependent and culture-independent approaches. Adult female mites were collected from apiaries in Chiang Mai and Lampang provinces. Culturable bacteria were isolated from individual mites. On average, we observed approximately 1340 and 1140 CFU/mite in Varroa and Tropilaelaps, respectively. All isolates were assigned to the genus Enterococcus. Six samples of genomic DNA from 30-50 mites were extracted and subjected to pyrosequenc…
Temporal frames of 45S rDNA site-number variation in diploid plant lineages: lessons from the rock rose genus Cistus (Cistaceae)
2016
The perception that the turnover of 45S rDNA site number in plants is highly dynamic pervades the literature on rDNA evolution. However, most reported evidences come from the study of polyploid systems and from crop species subjected to intense agronomic selection. In sharp contrast with polyploids, the evolutionary patterns of rDNA loci number in predominantly diploid lineages have received less attention. Most studies on rDNA loci changes lack explicit temporal frames, and hence their dynamics could not be assessed. Here, we assess the temporal patterns of rDNA site evolution in Cistus, an entirely diploid lineage. We assessed the number and chromosomal position of 45S rDNA loci in Cistus…
Intra-tumour heterogeneity of diffuse large B-cell lymphoma involves the induction of diversified stroma-tumour interfaces
2020
Abstract Background Intra-tumour heterogeneity in lymphoid malignancies encompasses selection of genetic events and epigenetic regulation of transcriptional programs. Clonal-related neoplastic cell populations are unsteadily subjected to immune editing and metabolic adaptations within different tissue microenvironments. How tissue-specific mesenchymal cells impact on the diversification of aggressive lymphoma clones is still unknown. Methods Combining in situ quantitative immunophenotypical analyses and RNA sequencing we investigated the intra-tumour heterogeneity and the specific mesenchymal modifications that are associated with A20 diffuse large B-cell lymphoma (DLBCL) cells seeding of d…
A practical algorithmic approach to mature aggressive B cell lymphoma diagnosis in the double/triple hit era. Selecting cases, matching clinical bene…
2019
An accurate diagnosis of clinically distinct subgroups of aggressive mature B cell lymphomas is crucial for the choice of proper treatment. Presently, precise recognition of these disorders relies on the combination of morphological, immunophenotypical, and cytogenetic/molecular features. The diagnostic workup in such situations implies the application of costly and time-consuming analyses, which are not always required, since an intensified treatment option is reasonably reserved to fit patients. The Italian Group of Haematopathology proposes herein a practical algorithm for the diagnosis of aggressive mature B cell lymphomas based on a stepwise approach, aimed to select cases deserving mo…