ObjectiveTo study the changes of cellular immunity caused by intravenous infusion of allogenic rhesus mesenchymal stem cells (MSCs).MethodsMSCs were isolated and cultured.Then the immunomodulatory effects after MSCs infusion were evaluated by means of peripheral blood counts,mixed lymphocyte reaction (MLR) and analysis of lymphocytic subgroup. ResultsMSCs of rehsus were successfully cultivated. No acute toxicities or GVHD were observed in recipients. No obvious changes of peripheral blood counts were present. Recipients A2, A3, A4 were administered with MSC by 4.0 ×105/kg, 1.0 ×106/kg, 2.0×106/kg respectively and relative reaction (RR) of MLR decreased 14 days post MSCs infusion: from 46±2.6 ％to 40.4±1.73 ％ (F =10.19, P =0.023), from (40.9±2.3) ％ to (33±2.1) ％ (F =2.593, P =0.013), from 48.3±2.0 ％ to 39±1.0 ％ (F =28.431, P =0.003) respectively. The decrease degree (ARR) was positively related to the amount of MSCs(F =27.413, P =0.038). RR was restored within 30 days post MSCs infusion. After MSCs infusion, CD3+ CD3+CD4+ and CD3+CD8+ T-lymphocytes decreased in recipient A4, who was administered with the largest number of MSCs, and restored within 30 days. ConclusionMSCs infusion without any other treatment could temporarily inhibit immunity of T lymphocytes in MLR and the immunity inhibition was positively related to the amount of MSCs.The specific immunological characteristics of MSCs were demonstrated with extensive prospect in clinical research.

Objective: To examine sleep characteristics of preschool children who were born preterm, which could provide a reference for the future intervention in the risk population. Methods: This retrospective cohort study was conducted from March 2017 to November 2018 in hospitals in cities of Guangzhou, Zhongshan, and Shenzhen, Guangdong Province, China, we recruited 202 preschool children aged 4-6 years, including 40 early-and moderate preterm (gestational age <34 weeks), 56 late preterm (34-36 weeks) , and 106 full-term preschool children (≥37 weeks). Caregivers reported children’s sleep time and habits using Chinese version of Children’s Sleep Habits Questionnaire (CSHQ). Results: Compared to the full-term group, the very-or-moderate-preterm group had shorter nighttime sleep duration (9.07±0.75 vs 9.33±0.59 h; adjusted β=-0.33), shorter total sleep duration (10.39±0.86 vs 11.05±1.32 h; adjusted β=-0.70), higher sleep duration score of CSHQ (4.60 ± 1.57 vs 3.97 ± 1.25 points; adjusted β=0.58), and higher sleepdisordered breathing score of CHSQ (3.78±1.27 vs 3.41±0.71 points; adjusted β=0.49). The late preterm group had lower parasomnias score of CSHQ (8.40±1.65 vs 8.75±1.72 points; adjusted β=-0.57), than the full-term group(P<0.05). When gestational age was analyzed as a continuous variable, it was positively associated with the total sleep duration (adjusted β= 0.06), while was inversely associated with sleep-disordered breathing scores of CSHQ (adjusted β=-0.06). Conclusion Very-or-moderate preterm children have shorter sleep duration and more sleep disordered breathing problems than full-term children, and have more disorders of sleeping duration and sleeping breathing than full-term children, while the late preterm children have less sleeping disorders than full-term children. The children of lower gestational age can have shorter sleep duration and more sleep-disordered breathing which should be addressed in future intervention.

3-Phosphoglycerate dehydrogenase (PGDH, EC 1.1.1.95) is the key enzyme in L-serine biosynthesis and its coding gene is serA. PGDH is feedback inhibited by L-serine. In order to relieve the feedback-inhibition of PGDH by L-serine, H344 or D346 or D364 were chosen for site directed mutagenesis. The mutants were generated by the standard QuikChange mutagenesis, further subcloned into expression vector pT7-7 and transformed into Escherichia coli BL21 (DE3) cells. The recombinant cells were collected after cultured in LB media post induced by isopropyl beta-Dthiogalactopyranoside. The enzymes were purified by anion exchange chromatography, and SDS-PAGE showed that the purified enzymes were homogenous. Enzyme characterization indicated that the mutant enzyme showed similar activity, optimal temperature, and optimal pH as that of the wild-type enzyme. Moreover, feedback inhibition study showed that the activity of the double mutant (N346A/H344A) could remain 96% in the presence of serine up to 160 mmol/L, whereas the activity of the wild-type enzyme remains only 50% in the presents of serine of 7 μmol/L, thus successfully relieving the feedback inhibition of PGDH with its activity remained.
Electrophoresis, Polyacrylamide Gel ; Escherichia coli ; enzymology ; Escherichia coli Proteins ; genetics ; Industrial Microbiology ; Mutagenesis, Site-Directed ; Phosphoglycerate Dehydrogenase ; genetics ; Serine ; biosynthesis

Rhus chinensis is an important economic species, which could provide raw materials for pharmaceutical and industrial dyes. Rhus chinensis is famous for its resistance to drought, cold, and salt. It grows in temperate, warm temperate, and subtropical regions. We report here Rhus chinensis chloroplast genomes by de novo sequencing. The results show that the length of Rhus chinensis was 159 082 bp, exhibiting a typical four-part structure with two single-copy regions (long single copy [LSC] and short single copy [SSC] sections) separated by a pair of inverted repeats (IRs). The length of LSC and SSC was 85 394 bp and 18 663 bp, respectively. The genomes contained 126 genes, including 88 protein encoding genes, 8 rRNA and 30 tRNA genes. In the chloroplast genome, 61.97% of the sequence were gene coding region. In the sequence of gene encoding region, the vast majority of sequences were protein encoding region, accounting for 86.65%, followed by rRNA (10 620 bp, 10.77%) and tRNA (2 540 bp, 2.58%). In Rhus chinensis chloroplast genome, only 8 genes contain introns, all containing 1 intron except ycf3 gene (2 introns). The Rhus chinensis chloroplast genome contains 755 SSR locies. SSR mainly consists of dinucleotide and mononucleotide, accounting for 60% (453) and 28.74% (217) respectively. The clustering results show that Anacardiaceae were closest to Rhus chinensis, followed by Aceraceae and Sapindaceae. This study provides a molecular basis for the classification of Rhus chinensis.
Genome, Chloroplast ; genetics ; Open Reading Frames ; Phylogeny ; Rhus ; classification ; genetics ; Sequence Analysis, DNA