Background: As a large capillary network, the human placenta plays an important role throughout pregnancy. Placental vascular development is complex and delicate and involves many types of placental cells, such as trophoblasts, and mesenchymal stem cells. There has been no systematic, comparative study on the roles of these two groups of placental cells and the whole placental tissue in the placental angiogenesis. In this study, primary cytotrophoblasts (CTBs) from early pregnancy and primary human placenta-derived mesenchymal stem cells (hPDMSCs) from different stages of pregnancy were selected as the cell research objects, and full-term placental tissue was selected as the tissue research object to detect the effects of their conditioned medium (CM) on human umbilical vein endothelial cell (HUVEC) angiogenesis. Methods: We successfully isolated primary hPDMSCs and CTBs, collected CM from these placental cells and sub-cultured placental tissue, and then evaluated the effects of the CM on a series of angiogenic processes in HUVECs in vitro. Furthermore, we measured the levels of angiogenic factors in the CM of placental cells or tissue by an angiogenesis antibody array. Results: The results showed that not only placental cells but also sub-cultured placental tissue, to some extent, promoted HUVEC angiogenesis in vitro by promoting proliferation, adhesion, migration, invasion, and tube formation. We also found that primary placental cells in early pregnancy, whether CTBs or hPDMSCs, played more significant roles than those in full-term pregnancy. Placental cell-derived CM collected at 24 h or 48 h had the best effect, and sub-cultured placental tissue-derived CM collected at 7 days had the best effect among all the different time points. The semiquantitative angiogenesis antibody array showed that 18 of the 43 angiogenic factors had obvious spots in placental cell-derived CM or sub-cultured placental tissue-derived CM, and the levels of 5 factors (including CXCL-5, GRO, IL-6, IL-8, and MCP-1) were the highest in sub-cultured placental tissue-derived CM. Conclusions: CM obtained from placental cells (primary CTBs or hPDMSCs) or sub-cultured placental tissue contained proangiogenic factors and promoted HUVEC angiogenesis in vitro. Therefore, our research is helpful to better understand placental angiogenesis regulation and provides theoretical support for the clinical application of placental components, especially sub-cultured placental tissue-derived CM, in vascular tissue engineering and clinical treatments.

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is a common enzymatic disorder of the erythrocytes that affects 400 million people worldwide. We developed a PCR-reverse dot blot (RDB) assay to screen twenty genotypes of seventeen Chinese G6PD mutations and investigate the spectrum of G6PD deficiency mutations in Dongguan District, Guangdong Province, in southern China. The PCR-RDB assay consists of multiplex PCR amplification of seven fragments in the G6PD target sequence of wild-type and mutant genomic DNA samples followed by hybridization to a test strip containing allele-specific oligonucleotide probes. A total of 16,464 individuals were analyzed by a combination of phenotypic screening and genotypic detection using the PCR-RDB assay and DNA sequence analysis. The PCR-RDB assay had a detection rate of 98.1%, which was validated by direct sequencing in a blind study with 100% concordance. The G6PD deficiency incidence rate in Dongguan District is 4.08%. Thirty-two genotypes from 469 individuals were found. The two most common variants were c.1376G>T and c.1388G>A, followed by c.95A>G, c.871G>A, c.392G>T, and c.1024 C>T. In addition, two rare mutations (c.703C>A and c.406C>T) were detected by DNA sequencing analysis. In our study, 65 cases harbored the C1311T/IVS polymorphism and 67 cases were homozygote. The PCR-RDB assay we established is a reliable and effective method for screening G6PD mutations in the Chinese population. Data on the spectrum of mutations in the Dongguan District is beneficial to the clinical diagnosis and prevention of G6PD deficiency.

Background: Thalassemia is a common inherited hematological disease in tropical and subtropical regions. This study aimed to investigate the mutation spectrum of thalassemia in the Dongguan region of southern China and comprehensively analyze hematologic features of thalassemia carriers with various types of globin mutations. Methods: A hematological screening including hematological indices such as mean corpuscular volume (MCV), mean corpuscular hemoglobin content (MCH), and mean corpuscular hemoglobin concentration (MCHC) was conducted in 19 442 people from Dongguan region, Guangdong province of China. Then, 4891 suspected thalassemia carriers were further investigated by genetic analysis of combined NGS and gap‐PCR. Results: Totally, 2319 (11.9%) cases were diagnosed as carriers of thalassemia, of which 1483 cases (7.6%) were α‐thalassemia, 741 cases (3.8%) were β‐thalassemia, and 95 cases (0.5%) were co‐inheritance of α‐ and β‐thalassemia. In α‐thalassemia carriers, the phenotypic severity increases with the number of nonfunctional α‐globin genes. The patients with – ^SEA /α ^WS α genotype have less severe clinical phenotypes than those with other Hb H diseases. As for β‐thalassemia, the MCV and MCH in both β ⁰ and β ⁺ carriers are markedly reduced. Conclusions: This is the first comprehensive molecular epidemiological survey and hematological profiling of thalassemia in Dongguan area. This study will be benefit for genetic counseling in the clinic and may help pediatricians to make a correct diagnosis of different types of thalassemia.

Genetic defects in the mitochondrial aminoacyl-tRNA synthetase are important causes of mitochondrial disorders. VARS2 is one of the genes encoding aminoacyl-tRNA synthetases. Recently, an increasing number of pathogenic variants of VARS2 have been reported. We report the novel compound heterozygous pathogenic VARS2 mutations c.643 C > T (p. His215Tyr) and c.1354 A > G (p. Met452Val) in a female infant who presented with poor sucking at birth, poor activity, hyporeflexia, hypertonia, persistent pulmonary hypertension of newborn (PPHN), metabolic acidosis, severe lactic acidosis, expansion and hypertrophic cardiomyopathy. These heterozygous mutations were carried individually by the proband’s parents and elder sister; the two mutations segregated in the family and were the cause of the disease in the proband.The c.643 C > T (p. His215Tyr) mutation was not described in the ExaC, GNomAD and 1000 Genomes Project databases, and the frequency of c.1354 A > G (p. Met452Val) was < 0.001 in these gene databases.The two mutated amino acids were located in a highly conserved region of the VARS2 protein that is important for its interaction with the cognate tRNA. The two missense mutations were predicted by online tools to be damaging and deleterious. Our report expands the spectrum of known pathogenicVARS2 variants associated with mitochondrial disorders in humans.VARS2 deficiency may cause a severe neonatal presentation with structural cardiac abnormalities.

Bacterial pathogens are a major cause of childhood community acquired lower respiratory tract infections (CA-LRTIs), and few data described the impact of antimicrobial resistance on children with CA-LRTIs. This study aims to investigate the antimicrobial resistance in common bacterial agents among hospitalized children with CA-LRTIs between 2011 and 2016 in Dongguan, China. Sputum samples were collected from hospitalized children (0–5 years old) with CA-LRTIs in Dongguan Children’s Hospital. Bacterial pathogens were detected using traditional culture methods, and disc diffusion tests were used to determine antibiotic resistance. Among the 2360 samples analyzed, 342 (14.5%) were positive for bacterial infection. The most prevalent pathogen was MSSA (2.3%), followed by MRSA (1.5%), E. coli (1.7%), E. coli ESBLs (1.2%), K. pneumonia ESBLs (1.5%), K. pneumonia (1.4%) and S. pneumonia (1.3%). Of the hospitalized patients with bacteria causing of CA-LRTIs, 90.1% were less than 1-year-old. MSSA and MRSA were more commonly isolated in infants less than 3 months. E. coli, K. pneumonia and K. pneumonia ESBLs were more common bacteria causing CA-LRTIs in infants less than 1 month. Resistance levels to penicillins, fluoroquinolones, macrolides, cephalosporins, carbapenems and vancomycin varied in different bacteria. S. aureus, E coli and K. pneumonia were the common bacterial isolates recovered from chidren with CA-LTRIs during 2011–2015. Age group of under 1 year old was at a high risk of bacterial infections. Many isolates showed antibiotic resistance level was associated with antibiotic usage in clinic. Increasing surveillance of antibiotic resistance is urgently needed and develops better strategies to cure the antibiotic abuse in China.