No abstract

No abstract

No abstract

It has been verified that placenta contains multi-lineage mesenchymal stem cells (MSCs). We have used a time-gradient attachment method to isolate placenta-derived MSCs (PMSCs). The morphology, differentiation potential, immunogenicity and xenogenic reconstruction potential of these PMSCs were examined. The results showed that PMSCs isolated using the time-gradient attachment method showed higher potential of in vitro proliferation and multi-lineage differentiation. PMSCs isolated using the time-gradient attachment method showed a low immunogenicity. HLA-A gene fragment and no HLA-DR gene fragment were detected in PMSCs isolated using the time-gradient attachment method, and the mixed lymphocyte reaction (MLR) assay identified that these cells inhibited the proliferation of the allogeneic T-lymphocytes induced by PHA. The transplantation in calvaria of rats showed that PMSCs had the higher xenogenic reconstruction potential. Finally, the significance of PMSCs isolated using the time-gradient attachment method in experimental and clinical applications is discussed.

BackgroundRecent advances in semiconductor sequencing platform (SSP) have provided new methods for preimplantation genetic diagnosis/screening (PGD/S). The present study aimed to evaluate the applicability and efficiency of SSP in PGD/S.MethodsThe artificial positive single-cell-like DNAs and normal single-cell samples were chosen to test our semiconductor sequencing platform for preimplantation genetic diagnosis/screening (SSP-PGD/S) method with two widely used whole-genome amplification (WGA) kits. A total of 557 single blastomeres were collected from in vitro fertilization (IVF) couples, and their WGA products were processed and analyzed by our SSP-PGD/S method in comparison with array comparative genomic hybridization (array-CGH).ResultsOur SSP-PGD/S method indicated high compatibilities with two commercial WGA kits. For 557 single blastomeres, our method with four million reads in average could detect 24-chromosome aneuploidies as well as microdeletion/microduplication of the size over 4 Mb, providing 100% consistent conclusion with array-CGH method in the classification of whether it was transplantable.ConclusionsOur studies suggested that SSP-PGD/S represents a valuable alternative to array-CGH and brought PGD/S into a new era of more rapid, accurate, and economic.Electronic supplementary materialThe online version of this article (10.1186/s40246-018-0187-x) contains supplementary material, which is available to authorized users.

BackgroundNon-invasive prenatal testing (NIPT) as alternative screening method had been proven to have very high sensitivity and specificity for detecting common aneuploidies such as T21, T18, and T13, with low false positive and false negative rates. Unfortunately, recent studies suggested that the NIPT achieved lower accuracy in sex chromosomal aneuploidies (SCAs) detection than autosomal aneuploidies detection. BGISEQ-500 powered by Combinatorial Probe-Anchor Synthesis (CPAS) and DNA Nanoballs (DNBs) technology that combined linear amplification and rolling circle replication to reduce the error rate while enhancing the signal. Therefore, NIPT based on CPAS might be a good method for SCAs screening in routine clinical practice. In the study, we intended to evaluate the clinical utility of NIPT based on CPAS on screening for fetal SCAs.ResultsA total of 570 pregnant women were included in the retrospective study. Maternal blood samples were collected for NIPT; amniocentesis was performed on all pregnant women. NIPT was carried out by BGISEQ-500 sequencing platform based on CPAS. Karyotype analysis of amniotic cells was performed by standard G-banding techniques. 43 out of the total 570 pregnant women tested by NIPT showed fetal SCAs (19 of 45,X, 12 of 47,XXY, 10 of 47,XXX, and 2 of 47,XYY). The following amniocentesis confirmed that 26 cases were true positive (7 of true positive 45,X, 9 of true positive 47,XXY, 9 of true positive 47,XXX as well as 1 of 47,XYY) and the positive predictive value (PPV) for fetal SCAs was 60.47%. In addition, the PPV of advanced maternal age group (67.74%) was higher than the other indications group (45.45%) or serological screening high-risk /critical-risk group (0%).ConclusionsNIPT based on CPAS could be a potential method for SCAs screening. However, it still had high false positive rates, especially for 45,X. The pregnant women with fetal SCAs detected by NIPT, especially those with non-age-related prenatal diagnostic indications, should be advised to accept invasive prenatal karyotype analysis.

Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD) are caused by mutations in the DMD gene. The aim of this study is to identify pathogenic DMD variants in probands and reduce the risk of recurrence of the disease in affected families. Variations in 100 unrelated DMD/BMD patients were detected by multiplex ligation-dependent probe amplification (MLPA) and next-generation sequencing (NGS). Pathogenic variants in DMD were successfully identified in all cases, and 11 of them were novel. The most common mutations were intragenic deletions (69%), with two hotspots located in the 5' end (exons 2-19) and the central of the DMD gene (exons 45-55), while point mutations were observed in 22% patients. Further, c.1149+1G>A and c.1150−2A>G were confirmed by hybrid minigene splicing assay (HMSA). This two splice site mutations would lead to two aberrant DMD isoforms which give rise to severely truncated protein. Therefore, the clinical use of MLPA, NGS, and HMSA is an effective strategy to identify variants. Importantly, eight embryos were terminated pregnancies according to prenatal diagnosis and a healthy boy was successfully delivered by preimplantation genetic diagnosis (PGD). Early and accurate genetic diagnosis is essential for prenatal diagnosis/PGD to reduce the risk of recurrence of DMD in affected families.

No abstract