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Prenatal Samples (prenatal + sample)
Selected AbstractsRetinoic acid signalling induces the differentiation of mouse fetal liver-derived hepatic progenitor cellsLIVER INTERNATIONAL, Issue 10 2009Jiayi Huang Abstract Background: Hepatic progenitor cells (HPCs) can be isolated from fetal liver and extrahepatic tissues. Retinoic acid (RA) signalling plays an important role in development, although the role of RA signalling in liver-specific progenitors is poorly understood. Aims: We sought to determine the role of RA in regulating hepatic differentiation. Methods: RNA was isolated from liver tissues of various developmental stages. Liver marker expression was assessed by reverse transcriptase-polymerase chain reaction and immunofluorescence staining. Reversibly immortalized HPCs derived from mouse embryonic day 14.5 (E14.5) liver (aka, HP14.5) were established. Albumin promoter-driven reporter (Alb-GLuc) was used to monitor hepatic differentiation. Glycogen synthesis was assayed as a marker for terminal hepatic differentiation. Results: Retinoic acid receptor (RAR)-,, retinoid X receptor (RXR)-, and RXR-, expressed in E12.5 to postnatal day 28 liver samples. Expression of RAR-, and RXR-, was low perinatally, whereas RAR-, was undetectable in prenatal tissues and increased postnatally. Retinal dehydrogenase 1 and 2 (Raldh1 and Raldh2) were expressed in all tissues, while Raldh3 was weakly expressed in prenatal samples but was readily detected postnatally. Nuclear receptor corepressors were highly expressed in all tissues, while expression of nuclear co-activators decreased in perinatal tissues and increased after birth. HP14.5 cells expressed high levels of early liver stem cell markers. Expression of RA signalling components and coregulators was readily detected in HP14.5. RA was shown to induce Alb-GLuc activity and late hepatocyte markers. RA was further shown to induce glycogen synthesis in HP14.5 cells, an important function of mature hepatocytes. Conclusions: Our results strongly suggest that RA signalling may play an important role in regulating hepatic differentiation. [source] Diagnostic yield by supplementing prenatal metaphase karyotyping with MLPA for microdeletion syndromes and subtelomere imbalancesPRENATAL DIAGNOSIS, Issue 10 2010S. Kjaergaard Abstract Objective The aim of the study was to retrospectively assess the relevance of using multiplex ligation-dependent probe amplification (MLPA) for detection of selected microdeletion syndromes (22q11, Prader,Willi/Angelman, Miller,Dieker, Smith,Magenis, 1p-, Williams), the reciprocal microduplication syndromes and imbalance at the subtelomere regions of chromosomes in a routine prenatal setting. Method A total of 530 prenatal samples were analysed by commercial MLPA kits (SALSA P064, P036 and P069) in addition to rapid aneuploidy testing and G-band karyotyping. Results Among the prenatal samples with a normal metaphase karyotype, nine submicroscopic imbalances were detected: seven 22q11 deletions (Velocardiofacial/DiGeorge syndrome), one 15q11deletion (Prader,Willi syndrome) and one terminal deletion of the short arm of chromosome 4 (Wolf,Hirschhorn syndrome). All imbalances were found in amniocentesis (AC) taken due to fetal structural malformation and/or other ultrasound scan (US) detected abnormality. The diagnostic yield was 4.1% in the subgroup with structural malformation and 1.6% in the subgroup with other US abnormality. Conclusion The data set substantiates that additional MLPA analyses for selected microdeletions and subtelomere imbalances are valuable in routine prenatal diagnostics, when a malformation(s) and/or other abnormalities are detected by US. In contrast, the additional MLPA analyses gave no diagnostic yield in case of increased nuchal translucency (NT). Copyright © 2010 John Wiley & Sons, Ltd. [source] Resolution of trisomic mosaicism in prenatal diagnosis: estimated performance of a 50K SNP microarrayPRENATAL DIAGNOSIS, Issue 13 2007Jillian Cross Abstract Objective To evaluate the ability of a DNA single nucleotide polymorphism (SNP) microarray to detect chromosome mosaicism for trisomy in prenatal samples in order to compare this with conventional cytogenetics. Method We created a dilution series of mock mosaic samples, by mixing measured amounts of fibroblast cells containing trisomy 8 from a male with aliquots of cells with a normal female karyotype. DNAs were extracted from these mosaic mixtures, then analysed on the Affymetrix 50K Xba SNP chip. Duplicate aliquots of each mosaic sample were probed using interphase FISH, with centromeric probes for chromosomes X, Y and 8, to estimate independently the proportion of male trisomy 8 in each sample. Data from the arrays were analysed using publicly available analysis tools. Statistical calculations were then performed using a Student's t -test to determine if there was a significant difference between the copy numbers of each chromosome. Results These experiments using the Affymetrix 50K Xba SNP microarray showed mosaicism to be obvious at 20% and with additional statistical calculations, the lower limit for detection is about 10%. Conclusion The SNP microarray platform tested can detect mosaicism for trisomy in prenatal samples at levels comparable with conventional cytogenetic techniques in routine use. Copyright © 2007 John Wiley & Sons, Ltd. [source] Rapid prenatal diagnosis of common trisomies: discordant results between QF-PCR analysis and karyotype analysis on long-term culture for a case of trisomy 18 detected in CVSPRENATAL DIAGNOSIS, Issue 12 2006S. K. Allen Abstract Objectives QF-PCR analysis can be used as a rapid test to diagnose primary trisomy in prenatal samples. Mosaicism in CVS detected by QF-PCR has previously been reported; however, no case has so far been reported in which the QF-PCR result was completely discrepant to that of the karyotype analysis from a long-term culture. Methods A CVS, referred because of a high serum screening risk of 1:10 for Down Syndrome and 1:110 for Edwards Syndrome, was tested by QF-PCR analysis and chromosome analysis of cultured cells. Subsequent analyses were carried out on a follow-up amniotic fluid sample and foetal tissue samples. Results Conflicting results were obtained between QF-PCR analysis on two independent fronds from the chorionic villi and chromosome analysis on cultured CVS. Cytogenetic and molecular analysis on a subsequent amniotic fluid sample indicated trisomy 18 with no evidence of mosaicism. Analysis of follow-up tissue confirmed trisomy in a foetal skin sample and mosaicism for trisomy 18 in four placental sites tested. Conclusion We report here an apparently normal CVS QF-PCR result that was completely discrepant with the trisomy 18 positive karyotype result on long-term culture. This has important implications regarding our current testing protocol. Copyright © 2006 John Wiley & Sons, Ltd. [source] The future of prenatal diagnosis: rapid testing or full karyotype?BJOG : AN INTERNATIONAL JOURNAL OF OBSTETRICS & GYNAECOLOGY, Issue 10 2005An audit of chromosome abnormalities, pregnancy outcomes for women referred for Down's Syndrome testing Objective To assess the implications of a change in prenatal diagnosis policy from full karyotype analysis to rapid trisomy testing for women referred primarily for increased risk of Down's Syndrome. Design Retrospective collection and review of data. Setting The four London Regional Genetics Centres. Population Pregnant women (32,674) in the London area having invasive prenatal diagnosis during a six-year three-month period. Methods Abnormal karyotypes and total number of samples referred for raised maternal age, raised risk of Down's Syndrome following serum screening or maternal anxiety were collected. Abnormal karyotypes detected by molecular trisomy detection were removed, leaving cases with residual abnormal karyotypes. These were assessed for their clinical significance. Pregnancy outcomes were ascertained by reviewing patient notes or by contacting obstetricians or general practioners. Main outcome measures Proportion of prenatal samples with abnormal karyotypes that would not have been detected by rapid trisomy testing, and the outcome of those pregnancies with abnormal karyotypes. Results Results from 32,674 samples were identified, of which 24,891 (76.2%) were from women referred primarily for Down's Syndrome testing. There were 118/24,891 (0.47%) abnormal sex chromosome karyotypes. Of the samples with autosomal abnormalities that would not be detected by rapid trisomy testing, 153/24,891 (0.61%) were in pregnancies referred primarily for Down's Syndrome testing. Of these, 98 (0.39%) had a good prognosis (46/98 liveborn, 3/98 terminations, 1/98 intrauterine death, 1/98 miscarriage, 47/98 not ascertained); 37 (0.15%) had an uncertain prognosis (20/37 liveborn, 5/37 terminations; 12/37 not ascertained) and 18 (0.07%) had a poor prognosis (1/18 liveborn, 2/18 miscarriage, 11/18 terminations, 4/18 not ascertained). Conclusions For pregnant women with a raised risk of Down's Syndrome, a change of policy from full karyotype analysis to rapid trisomy testing would result in the failure to detect chromosome abnormalities likely to have serious clinical significance in approximately 0.06% (1 in 1659) cases. However, it should be noted that this figure may be higher (up to 0.12%; 1 in 833) if there were fetal abnormalities in some of the pregnancies in the uncertain prognosis group for which outcome information was not available. [source] | ||||||||||