[Current status and reflection on molecular diagnosis of birth defects].

Birth defects are a major problem threatening the health of children in China. Genetic factors play a major role in birth defect etiology. Molecular diagnosis is the key means for screening, diagnosing, and preventing birth defects caused by genetic factors. How to carry out large-scale and cost-effective molecular diagnosis in clinical practice is a major challenge in the prevention and treatment of birth defects in China. This article reviews the current status of birth defects in China, the application of molecular diagnostic technology in birth defect prevention and control, and the challenges in promoting its use, to provide references for clinical practice in birth defect molecular diagnosis.

[Advance in pathogenesis of oligodendrocytes-associated autism spectrum disorder].

Autism spectrum disorder (ASD) is a serious neurodevelopmental impairment of children. Because of its difficulty of early diagnosis, length of disease course, irreversible injury and slim chance of curability, it brings heavy burdens to patients, their families and the whole society. Recent studies have shown that the pathogenic mechanism of ASD is closely related to the abnormal myelination caused by the imbalance of differentiation, proliferation and apoptosis of oligodendroglial lineage cells. This article will review on the role of oligodendroglial lineage cells in myelination and the mechanisms of ASD caused by improper differentiation, proliferation and apoptosis of oligodendroglial lineage cells, according to advanced researches. Oligodendrocytes play vital roles in neurodevelopment, and the defect in these cells has been recognized as one of the key pathogenic mechanisms leading to ASD. Elucidating the effects and disciplines which oligodendrocytes exert on the occurrence and development of ASD would provide guidance for precise prevention and control of neurodevelopmental disorders such as ASD.

[Prevention and control of birth defects and rare diseases in the era of genomic medicine].

Birth defects and rare diseases have become major public health problems, and early prevention and control are the most effective interventions. In recent years, with the rapid development of genomic techniques such as high-throughput sequencing, the level of screening and diagnosis of genetic birth defects and rare diseases has been greatly improved. This article reviews the application of genomic technologies in the pre-pregnancy, preimplantation, prenatal and neonatal stages, as well as the trend of clinical transformation, highlighting the broad prospects of constructing an early and precise prevention and control system in the era of genomic medicine.

Myocyte enhancer factor 2C regulation of hepatocellular carcinoma via vascular endothelial growth factor and Wnt/ß-catenin signaling.

Hepatocellular carcinoma (HCC) is one of the leading malignancies worldwide. Myocyte enhancer factor 2C (MEF2C) was traditionally regarded as a development-associated factor and was recently reported to be an oncogene candidate. We have previously reported overexpression of MEF2C in HCC; however, the roles of MEF2C in HCC remain to be clarified. In this study, HCC cell lines and a xenograft mouse model were used to determine the functions of MEF2C in vitro and in vivo, respectively. Specific plasmids and small interfering RNA were used to upregulate and downregulate MEF2C expression, respectively. Functional assays were performed to assess the influence of MEF2C on cell proliferation, and VEGF-induced vasculogenic mimicry, migration/invasion as well as angiogenesis. Co-immunoprecipitation was conducted to identify the interaction of MEF2C and ß-catenin. Human HCC tissue microarrays were used to investigate correlations among MEF2C, ß-catenin and involved biomarkers. MEF2C was found to mediate VEGF-induced vasculogenic mimicry, angiogenesis and migration/invasion, with involvement of the p38 MAPK and PKC signaling pathways. However, MEF2C itself inhibited tumor growth in vitro and in vivo. MEF2C was upregulated by and directly interacted with ß-catenin. The nuclear translocation of ß-catenin blocked by MEF2C was responsible for MEF2C-mediated growth inhibition. The nuclear translocation of MEF2C was associated with intracellular calcium signaling induced by ß-catenin. HCC microarrays showed correlations of nuclear MEF2C with the angiogenesis-associated biomarker, CD31, and cytosolic MEF2C with the proliferation-associated biomarker, Ki-67. MEF2C showed double-edged activities in HCC, namely mediating VEGF-induced malignancy enhancement while inhibiting cancer proliferation via blockade of Wnt/ß-catenin signaling. The overall effect of MEF2C in HCC progression regulation was dictated by its subcellular distribution. This should be determined prior to any MEF2C-associated intervention in HCC.

Identification of three FGA mutations in two Chinese families with congenital afibrinogenaemia.

Congenital afibrinogenaemia is a rare autosomal recessive disorder, characterized by the complete absence or extremely reduced level of fibrinogen (Fg). We attempted to analyse the phenotype and genotype in two Chinese families with congenital afibrinogenaemia. Coagulation studies including activated partial thromboplastin time (APTT), prothrombin time (PT) and thrombin time (TT) and Fg were performed in the patients and other family members. All the exons, exon-intron boundaries and promoter regions of three Fg genes (FGA, FGB and FGG) were screened by direct sequencing. Three patients in two families suffered from moderate to severe haemorrhage. Their APTT, PT and TT were extremely prolonged and plasma Fg levels were undetectable by Clauss method and extremely reduced by immunoassay. Genetic analysis revealed three FGA mutations in three patients including one novel mutation. In family 1, patient 1 was detected compound heterozygous mutations in FGA, g.1892-1899delAGTA/GTAA from her patriline and g.1978-g.3215del1238 bp from her matriline. In family 2, a homozygous Gln203X in Aalpha-chain was found in both patients 2 and 3 due to consanguineous marriage. All these mutations were null mutations, which could produce premature stop codons in FGA. It can be indicated that with more genetic analysis performed on afibrinogenaemia patients all over the world, there is no distinct difference in geographical distribution of Fg gene mutations. Gln203X in Aalpha-chain was first reported in this study, which may help to further understand the function of Aalpha-chain.

Molecular characterization of two novel mutations causing factor X deficiency in a Chinese pedigree.

Factor X (FX) deficiency is a rare bleeding disorder inherited as an autosomal recessive trait. In this study, we investigated the molecular basis of FX deficiency in a Chinese pedigree. The proposita showed a markedly prolonged activated partial thromboplastin time and a mild prolongation of prothrombin time. The levels of FX antigen and FX activity were 58.6% and 2.5%, respectively. Molecular analysis revealed that the proposita was compound heterozygous for two novel mutations: IVS1 + 1G > A and G1185A (Arg347His). The aberrant transcripts from the IVS1 + 1G > A mutant allele were not detected by analyzing the splicing pattern of ectopic transcripts in leukocytes of the patient with nested polymerase chain reaction after reverse transcription. We thus hypothesize that the mRNA molecules originating from the IVS1 + 1G > A mutation were rapidly destroyed in vivo. Site-directed mutagenesis of FX cDNA was used to introduce FXG1185A mutation, and wild-type as well as mutant FX proteins were expressed by transient transfection in HEK 293 cells. Normal FX antigen levels both in the conditioned media of cells expressing the mutant and in cell lysates were detected by an enzyme-linked immunoadsorbent assay. Evaluation of wild-type and mutant coagulant activity demonstrated that the FX molecules carrying the Arg347His mutation have dramatically decreased activity.

Identification of three F5 gene mutations associated with inherited coagulation factor V deficiency in two Chinese pedigrees.

To investigate the molecular defects in two Chinese pedigrees with inherited factor V (FV) deficiency. A 37-year-old male (proband 1) and an 18-month-old boy (proband 2) were diagnosed as inherited coagulation FV deficiency by severely reduced plasma levels of FV activity and antigen. All 25 exons and their flanking sequence of F5 gene were amplified by polymerase chain reaction (PCR) for both probands and the PCR products were directly sequenced. Total RNA was extracted from the peripheral lymphocytes of proband 1 for detecting the changes at mRNA level. The homozygous deletion IVS8 -2A>G was identified in the F5 gene of proband 1 and complementary DNA (cDNA) analysis revealed the abolishment of the canonical splicing site by the mutation and the activation of the cryptic acceptor site 24 bp upstream instead. The insertion introduced eight additional amino acids (AA) into the FV protein. Two heterozygous mutations of F5 gene were discovered in proband 2. The 2238-9del AG in exon 13 introduced a premature termination code at 689 AA and the substitution of G6410 by T in exon 23 lead to the missense mutation Gly2079Val. Three F5 gene mutations, IVS8 -2A>G, 2238-9del AG and G6410T, have been identified in two Chinese pedigree with congenital FV deficiency, respectively.

[Primary study on infection of Epstein Barr virus in malignant tumors of oral and maxillofacial regions]

OBJECTIVE:To indicate the relationship between infection of the Epstein-Barr virus and malignant tumors of oral and maxillofacial regions.METHODS:The Epstein-Barr virus DNA was measured in tissues and saliva of 18 patients with malignant tumors of oral and maxillofacial regions by polymerase chain reaction (PCR).RESULTS:It showed that DNAs of EB virus fragment were amplified in tissues and saliva of 3 patients with salivary carcinoma,but negative in controls and squamous cell carcinomas and sarcomas.CONCLUSION:It indicated that there was association between Epstein-Barr virus and salivary carcinoma.

[Observation of soluble interleukin-2 receptor(sIL-2R) and tumor necrosis factor(TNF) in patients with malignant tumors of salivary gland]

OBJECTIVE:To To study the clinical significance of sIL-2R and TNF in patients with malignant tumors of salivary gland.METHODS:The serum levels of sIL-2R and TNF in 30 patients were measured using a sandwich enzyme-linked immunosorbent assay (ELISA) and radiation immune assay (RIA).RESULTS:The results showed that serum sIL-2R levels in patients were significantly higher than those of controls (P<0.01).Four weeks after operation,the sIL-2R levels could be seen again in recurrent or metastatic individuals.The levels of TNF were normal.CONCLUSION:The consecutive observation of serum sIL-2R levels is helpful to judge the prognosis and monitor the relapses and metastases of malignant tumors of salivary gland.

[A test of interleukin 2(IL-2) and T-cell subpopulation in patients with head and neck carcinomas]

OBJECTIVE:Serum levels of interleukin 2(IL-2) and peripheral blood T-cell subpopulation were measured in 35 patients with head and neck carcinomas.The results indicated that the pro-operative patients' CD8(+) was significantly higher,while the IL-2 level and CD4(+)/CD8(+) were greatly lower than that of controls (P<0.01),and CD4(+)was no significant difference.They were closely related with clinical stage.After operation,the CD8(+)decreated(P<0.01) and the serum IL-2 level,CD4(+)/CD8(+) elevated(p<0.01).It indicated that patients with head and neck carcinomas presented obvious abnormality of celluar immunological function.So,combined analysis of serum IL-2 and T-cell subpopulation may be useful to evaluate patients' immunological condition and to make up therapeutic plan.

[Ureaplasma urealyticum infection in spontaneous abortion].

Ureaplasma urealyticum in aborted tissue and cervical mucus were examined in 40 women with spontaneous abortion (test group), 20 women of induced abortion and 20 healthy pregnant women (control group). The results showed that the positive isolation rate of ureaplasma urealyticum was significantly higher in the test group than that in the control group (55.0% vs 10.0%). The detection rate of ureaplasma urealyticum increased along with the number of spontaneous abortion. It indicated that ureaplasma urealyticum might be a cause of unexplained spontaneous abortion.