[Application study of droplet digital PCR to detect maternal cell contamination in prenatal diagnosis].

Objective: To develop a new method based on droplet digital PCR (DD-PCR) for detection and quantification of maternal cell contamination in prenatal diagnosis. Methods: Invasive prenatal samples from 40 couples of ß(IVS-Ⅱ-654)/ß(N) thalassemia gene carriers who accepted prenatal diagnosis in Affiliated Women and Children's Hospital of Guangzhou Medical University from October 2015 to December 2016 were analyzed retrospectively. Specific primers and probes were designed. The concentration gradient were 50%, 25%, 12.5%, 6.25%, 3.125%, 1.562 5%. There were 40 groups of prenatal diagnostic samples. Comparing DD-PCR with quantitative fluorescent-PCR (QF-PCR) based on the short tandem repeats for assement of the sensitivity and accuracy of maternal cell contamination, respectively. Results: DD-PCR could quantify the maternal cell contamination as low as 1.562 5%. The result was proportional to the dilution titers. In the 40 prenatal samples, 6 cases (15%, 6/40) of maternal cell contamination were detected by DD-PCR, while the QF-PCR based on short tandem repeat showed 3 cases (7.5%, 3/40) with maternal cell contamination, DD-PCR was more accurate (P=0.002) . Conclusion: DD-PCR is a precise and sensitive method in the detection of maternal cell contamintation. It could be useful in clinical application.

[MRI evaluation of condylar bone regeneration after temporomandibular joint disc reduction and suture and analysis of factors affecting bone regeneration].

Objective: To evaluate the MRI manifestations of condylar bone regeneration after disc reduction and suture for anterior disc displacement without reduction (ADDWoR) patients and to analyze the relevant factors affecting bone regeneration. Methods: A total of 61 patients of 75 joints with ADDWoR who attended the Department of Maxillofacial Surgery of the Affiliated Hospital of Stomatology of Nanjing Medical University from April 2020 to December 2021 were enrolled in the study. The characteristics of MRI condylar bone regeneration were analyzed before and after surgery (follow-up for 6 months or more), and logistic regression analysis was performed on the influencing factors of bone regeneration. Results: The new bone formation of the condyle was found in 28 patients, with age of (20.2±4.9) years. However, there were 33 patients that had no condylar bone regeneration, with age of (41.9±17.5) years. A total of 35 joints in this study were found new bone formation. There were 16 joints (45.7%) had new bone formation on the posterior slope of the condyle, 10 joints (28.6%) around the condyle, 6 joints (17.1%) on the anterior slope of the condyle, and only 3 joints (8.6%) on the top of the condyle. Multivariate logistic regression analysis showed that age, preoperative disc length and degree of condylar bone resorption correlated with postoperative condylar bone regeneration(P<0.05). Patients younger than 30 years with non-shortened preoperative disc length and less condylar bone resorption have a higher probability of new bone formation. Conclusions: The condyle has bone regeneration capacity after correcting the abnormal relationship between disc and condyle, and young age, non-shortened preoperative disc length and less condylar bone resorption are conducive to postoperative condylar bone regeneration.

Gamma-glutamyltransferase levels and risk of metabolic syndrome: a meta-analysis of prospective cohort studies.

AIMS: Several epidemiological studies suggested that gamma-glutamyltransferase (GGT) levels may be associated with risk of Metabolic Syndrome (MetS). However, the exact association between them is still not fully clear. We therefore conducted a meta-analysis of prospective cohort studies to comprehensively evaluate the exact association between GGT and risk of MetS. METHODS: The Pubmed, Embase, Science Citation Index (ISI Web of Science) databases were searched to collect all prospective cohort studies on the association between GGT and MetS. Then, the association between GGT and MetS was analysed in qualitative and quantitative manners. RESULTS: Nine prospective cohort studies involving 47,499 participants and 5009 cases of MetS were included. When comparing the risk of MetS between the highest versus the lowest category of GGT levels, the pooled RR of MetS was 1.63 (95% CI: 1.43-1.82; p < 0.000). The second dose-response analysis of GGT levels per 5 U/l increment with risk of MetS showed that the summary RR of MetS was 1.09 (95% CI: 1.06-1.13; p < 0.000). Subgroup analysis suggested that number of adjusted confounding factors may be a potential source of heterogeneity. Sensitivity analyses showed that no single study significantly influenced the pooled RRs. CONCLUSIONS: Our results show that GGT levels are positively associated with risk of MetS independently of alcohol intake. GGT may be a promising marker for predicting MetS. Further studies are needed to confirm our findings and elucidate the underlying mechanisms in future.

A 4-miRNAs signature predicts survival in glioblastoma multiforme patients.

BACKGROUND: Although O(6)-methylguanine DNA methyltransferase (MGMT) promoter methylation status is an important marker for glioblastoma multiforme (GBM), there is considerable variability in the clinical outcome of patients with similar methylation profles. OBJECTIVE: We examined whether a MicroRNA (miRNA) signature can be identified for predicting clinical outcomes and helping in treatment decisions. METHODS: The differentially expressed miRNAs were evaluated in 6 pairs of short- (⩽ 450 days) and long-term survivors (> 450 days) by using microarray. Real time quantitative PCR (qRT-PCR) was applied to further verify screened miRNAs with a greater number of samples (n= 48). Meanwhile, functional interpretation of miRNA profile was carried out based on miRNA-target databases. In addition, MGMT promoter methylation status was tested by means of pyrosequencing (PSQ) testing. RESULTS: Six miRNAs were upregulated in the long-term survival group (fold change ⩾ 2.0, P< 0.05). The further verification by qRT-PCR indicated that the increase in let-7g-5p, miR-139-5p, miR-17-5p and miR-9-3p level in long-term survivors was statistically significant. Kaplan-Meier survival analysis showed that high expression of a prognostic 4-miRNA signature was significantly associated with good patient survival (p= 0.0012). The signature regulated signaling pathways including Calcium, MAPK, ErbB, mTOR and cell cycle involved in carcinogenesis from glial progenitor cell to primary GBM. CONCLUSIONS: The 4-miRNA signature was identified as an independent prognostic biomarker that identified patients who have a favorable outcome.