Iskanje po katalogu digitalne knjižnice

Opis: Purpose: About 10-15% of all pregnancies terminate as spontaneous miscarriages. In the first trimester, 50% of spontaneous miscarriages are the result of chromosomal aberrations, mostly chromosomal aneuploidies. Cytogenetic analyses are used to confirm aneuploidy in failed pregnancies. Culture failure or poor quality chromosomes are often problems in those cases. In such situations, methods that are independent of tissue culture areused, and we employed multiplex ligation-dependent probe amplification (MLPA). We determined if MLPA is an appropriate and compatible method compared with classical cytogenetic analyses on fetal tissues. Methods: All fetal samples received from spontaneous abortions were cultured, karyotyped (if possible) and genomic DNA extracted. MLPA analyses were undertaken using subtelomeric probe kits. Additionally, comparative genomic hybridization (CGH) was used to confirm aneuploidy detected by MLPA in cases of failed culture growth. Results: MLPA analyses confirmed an unbalanced chromosome abnormality identified by cytogenetic analyses in all cases in which tissue culture was successful, and provided data in cases of failed culture growth. Several common numeric chromosome aberrations were detected, as well as rare trisomies and other unbalanced chromosome rearrangements. Conclusions: MLPA analyses can provide information about the karyotype of a DNA sample if cytogenetic analyses are not possible because of a lack of viable cells or if only a small amount of genomic DNA is available. These data indicate that MLPA may also be a very useful method for early prenatal aneuploidy screening.
Ključne besede: pomnoževanje od ligacije odvisnih prob, številčne kromosomske preureditve, kariotip
Objavljeno v DKUM: 12.04.2024; Ogledov: 230; Prenosov: 10
Celotno besedilo (353,36 KB)
Gradivo ima več datotek! Več...
Gradivo je zbirka in zajema 1 gradivo!

Opis: Background: Oral and oropharyngeal squamous cell carcinomas (OSCC) are among the most common cancers. The poor survival rate among oral cancer patients can be attributed to several factors, one of them being lack of early detection. A key approach to this problem would be to detect potentially malignant lesion at their early stage. Using the FISH technique, oral brush cytology slides can be an easy and rapid screening approach for malignant cell detection. The present study was designed to detect hTERC and SOX2 amplifications in OSSC exfoliative tumor cells and evaluate whether those two gene amplifications might serve as a supportive biomarker in early detection and diagnosis of oral and oropharyngeal SCC. Results: Brush biopsies were collected from exophytic and exulcerated oral and oropharyngeal lesions of the oral cavity of 71 patients and 22 healthy controls. FISH techniques using a TERC-specific DNA probe and a SOX2 DNA specific probe both combined with a centromere 3-specific control probe was performed on the cytology slides. A 100 squamous epithelial cell nuclei of the smears per slide were analysed. As abnormal FISH pattern were considered amplified and polyploid patterns. From 71 brush biopsies of oropharynx and other locations in oral cavity analysed by FISH 49 were considered to be abnormal (69%). The over representation of polyploidy and/or TERC/SOX2 amplification in tumour samples was statistically significant when compared to controls (p = 0.01). Conclusion: SOX2 and TERC gene amplifications are common in all squamous cell carcinomas and their detection in early stages could be crucial for early detection and more accurate prognosis. Our study strongly suggests that early detection by FISH on cytobrushed samples could be a possible non-invasive screening method even before a tissue biopsy is performed.
Ključne besede: SOX and hTERC gene amplifications, brush biopsy, Oral, oropharyngeal squamous cell carcinoma
Objavljeno v DKUM: 29.06.2017; Ogledov: 1403; Prenosov: 402
Celotno besedilo (1,28 MB)
Gradivo ima več datotek! Več...

Opis: Background: Rearrangements involving chromosome 5p often result in two syndromes, Cri-du-chat (CdC) and Trisomy 5p, caused by a deletion and duplication, respectively. The 5p15.2 has been defined as a critical region for CdC syndrome; however, genotype-phenotype studies allowed isolation of particular characteristics such as speech delay, cat-like cry and mental retardation, caused by distinct deletions of 5p. A varied clinical outcome was also observed in patients with Trisomy 5p. Duplications of 5p10-5p13.1 manifest themselves in a more severe phenotype, while trisomy of regions distal to 5p13 mainly causes mild and indistinct features. Combinations of a terminal deletion and inverted duplication of 5p are infrequent in literature. Consequences of these chromosomal rearrangements differ, depending on size of deletion and duplication in particular cases, although authors mainly describe the deletion as the cause of the observed clinical picture. Case presentation: Here we present a 5-month-old Slovenian girl, with de novo terminal deletion and inverted duplication of chromosome 5p. Our patient presents features of both CdC and Trisomy 5. The most prominent features observed in our patient are a cat-like cry and severe malformations of the right ear. Conclusion: The cat-like cry, characteristic of CdC syndrome, is noted in our patient despite the fact that the deletion is not fully consistent with previously defined cat-like cry critical region in this syndrome. Features like dolichocephaly, macrocephaly and ear malformations, associated with duplication of the critical region of Trisomy 5p, are also present, although this region has not been rearranged in our case. Therefore, the true meaning of the described chromosomal rearrangements is discussed.
Ključne besede: deletion with inverted duplication of 5p, trisomy 5, cri-du-chat syndrome, cat-like cry, ear agenesis
Objavljeno v DKUM: 28.06.2017; Ogledov: 1566; Prenosov: 405
Celotno besedilo (1,07 MB)
Gradivo ima več datotek! Več...

Ključne besede: neoplazija mehurja, občutljivost in specifičnost, fluorescenčna in situ hibridizacija, genetski označevalci
Objavljeno v DKUM: 10.07.2015; Ogledov: 2663; Prenosov: 48
Povezava na celotno besedilo
Gradivo ima več datotek! Več...
Gradivo je zbirka in zajema 1 gradivo!

Opis: Purpose: Comparative genomic hybridization (CGH) is a molecular- cytogenetic technique used to identify chromosomal imbalances throughout a genome. Due to its complexity, the use of CGH as a regular diagnostic technique is limited to only a few diagnostic laboratories. In this study, we evaluated the potential applications of CGH as a diagnostic method in different post-natal clinical samples. Methods: Ten patients were recruited with submicroscopic chromosomal abnormalities ranging in size from 3.9 to 37 Mb. For the purpose of confirmation, CGH was applied to five cases where molecular karyotyping with MLPA was previously utilized to detect chromosome aneuploidy. To date, CGH was largely used for the identification of the complex karyotype in haematological malignancies. Results: In eight cases of haematological malignancies, we were able to resolve complex karyotypes with CGH. Utilizing CGH as a diagnostic tool, we detected chromosomal imbalances larger than 8 Mb. In addition, we confirmed all chromosomal aneuploidies that were previously detected with MLPA from embryonic tissues obtained from aborted fetuses. In this tissue, the cells were not mitotically active, and therefore, were inappropriate for the conventional cytogenetics. Conclusion: Because CGH is technically demanding and time consuming, this technique is likely to be inappropriate for screening purposes. However, we found that CGH may be very useful in sporadic cases, where the sample material is not mitotically active or in cases with complex karyotypes. Therefore, our results confirmed that CGH may be useful in laboratories that are unable to use micro-array CGH for economic reasons.
Ključne besede: primerjalna genomska hibridizacija, medicinska genetika, diagnostična metoda
Objavljeno v DKUM: 10.07.2015; Ogledov: 1647; Prenosov: 41
Povezava na celotno besedilo
Gradivo ima več datotek! Več...
Gradivo je zbirka in zajema 1 gradivo!