Objective:To systematically evaluate the effectiveness and safety of intra-articular in-jection of mesenchymal stem cells (MSCs) and hyaluronic acid (HA) in the treatment of knee osteoarthritis.Methods:The relevant literatures published in both English and Chinese were systematically searched in PubMed, Embase, Wanfang database, China Knowledge Network (CNKI), SinoMed database and other data-bases from inception to May 2020. Two researchers independently extracted data and evaluated the included literature. Risk assessment of literature bias was carried out. RevMan 5.3 software was used for Meta analysis, and the combined sensitivity were calculated.Results:Finally, 13 references were included, including a total of 726 patients with knee osteoarthritis. Meta-analysis results showed that compared with the HA group, the Western Ontario and McMaster University Osteopathic Index Total Score (WOMAC) [ MD=-10.92, 95% CI (-16.87, -4.96), P<0.01], the visual analogue scale (VAS) score [ MD=-1.70, 95% CI(-2.44, -0.95), P<0.01], and the knee joint Lequesne index score of MSCs group all decreased significantly [ MD=-13.78, 95% CI (-15.03,-12.52), P<0.01]. Furthermore, there was no significant difference in the incidence of adverse events (AEs) between the two groups [ RR=1.11, 95% CI(0.90, 1.37), P=0.33]. However, American Knee Association Score (AKS score) [ MD=-10.15, 95% CI(-22.33, 2.03), P=0.10] and whole-organ magnetic resonance imaging score (WORMS) [ MD=-3.93, 95% CI(-11.60, 3.75), P=0.32] were not statistically significant ( P>0.05). Conclusion:Compared with intra-articular injection of HA, intra-articular injection of MSCs can significantly improve the symptoms and dysfunction, and has favorable clinical tolerability and safety, suggesting that MSCs is expected to bea new treatment for knee osteoarthritis.

Objective To construct a eukaryotic expression vector in Pichia pastoris containing human tissue factor( hTF) gene,in order to achieve high level secretory expression in extracellular.Methods Expression plasmid, pGAPZaA-hTF, was constructed by inserting the synthesized sequence encoding human extracellular tissue factor into yeast expression vector pGAPZaA and transformed into Pichia pastoris SMD1168H with electroporation.Having been selected by Zeocin, transformants containing hTF cDNA were expressed in YPD, extracellular proteins were detected by SDS-PAGE and confirmed by Western bolt.Results Successfully constructed the recombinant pGAPZaA-hTF expression system in Pichia pastoris.SDS-PAGE showed that the molecular weight of the expression product was about 37 -40 kDa.Western-blot indicated that it was human extracellular tissue factor.The crude yield of total protein in medium was up to 1 g/L, more than 80% of which was hTF.Conclusion Truncated rTF gene is expressed in Pichia pastoris and the active products are secreted into the medium which have the same activation as the native TF.

Objective To explore the pathological changes of lung, expression of the relevant inflammatory factors and oxidative stress markers of Sprague-Dawley (SD) rats undergoing autologous orthotopic liver transplantation (AOLT). Methods Thirty SD rats were randomized into sham group and AOLT group. The pathological changes of lung, expression of the relevant inflammatory mediators and oxidative stress markers were detected . Results ( 1 ) Compared with the sham group , the pathological scores of lung tissue in AOLT group increased significantly and reached its peak at 8 h after surgery. Then the pathological scores decreased to the level of sham within 24 h to 48 h after surgery; (2)The relative expression of inflammatory mediators including TNF-α, IL-1β, IL-6 and IL-8 increased significantly and reached its peak at 8 h after surgery in AOLT group. Then decreased to the level of sham group within 24 h to 48 h after surgery; (3)The change trends of MDA and H2O2 were similar to inflammatory mediators.The relative SOD expression decreased significantly and touched the nadir at 8h after surgery and then increased. Conclusion The pathological changes of lung expression, the relevant inflammatory mediators and oxidative stress markers of rats underwent AOLT were consistent.

BACKGROUND:Tissue engineering provides new ideas and approaches for repair of cartilage defects.
OBJECTIVE:To develop a complete set of solutions for construction of tissue engineered cartilagein vitro, with chondrocytes as seed cels and cross-linked sodium hyaluronate as scaffold materials.
METHODS: New Zealand rabbit articular chondrocytes were isolated, counted, and then cultured and passaged to prepare cellsuspension. Toluidine blue staining, RT-PCR and immunocytochemistry were exerted to evaluate the cultured cels. Chondrocytes were seeded and co-cultured with cross-linked sodium hyaluronate scaffold for 21 days. Then, RNA was isolated for RT-PCR, and frozen sections were prepared for morphological observation and immunohistochemistry study.
RESULTS AND CONCLUSION:The chondrocytes could adhere to the cross-linked sodium hyaluronate scaffold and aggregate, growing between fibers or adhering to the scaffold in a monolayer manner. The transcripts of cartilage specific aggrecan gene and colagen type II alpha 1 gene and cartilage specific protein colagen type II were expressed in cel-scaffold complexes to maintain the phenotype of chondrocytes. Cel-scaffold complexes co-cultured in vitro can form cartilage extracelular matrix, by which tissue engineered cartilage is expected to be obtained.

Objective To investigate the serum IL-33 level and its association with TH1,TH2,TH17 and Treg cells in patients with unexplained recurrent spontaneous abortion(URSA).Methods Forty-six URSA patients and 40 healthy controls were enrolled.The proportions of TH1,TH2,TH17 and Treg cells in peripheral blood samples were determined by flow cytometry,and serum IL-33 levels by ELISA.Results The levels of serum IL-33 in URSA patients were significantly lower than that in healthy controls.The proportions of TH2 and Treg cells in URSA patients were significantly lower than that in healthy controls (P ＜ 0.05),while the proportions of TH 1 and TH 17 cells in URSA patients were significantly higher than that in healthy controls.Serum IL-33 levels were negatively correlated with the proportions of TH 1 and TH17 cells,and positively with that of TH2 cells,while no correlation with Treg cells.Conclusion Serum IL-33 levels decrease significantly in URSA patients,and are correlated with the proportions of TH1,TH2 and TH17 cells,indicating that IL-33 may be associated with TH1,TH2 and TH17 cells in URSA patients.

Objective To construct a prokaryotic expression vector in BL21 to secretorily expressα-Cyclodextrin Glycosyltransferase(α-CGTase). Methods α-CGT gene was amplified from Bacillus macerens genome by PCR.pET26b and α-CGT gene were connected after digested with Nco I, Xho I respectivly, and then transformed into Escherichia coli BL21 strain.α-CGTase was expressed in fermentation culture medium and AA-2G was prepared by using α-CGTase, VC and starch.Results α-CGTase was expressed secretorily and the enzyme activity was up to 120 U/mL.AA-2G was prepared by the biotransformation of VC and starch using α-CGTase which proved to be correct by HPLC.Conclusion AA-2G was prepared by using self-madeα-CGTase, after optimized the preparation conditions the yield of AA-2G was 17.46 g/L, and the conversion rate reached 58.2%(mg/mg).

Objective: To establish a method for detection of human antibodies against monkeypox virus. Mothds: The enzyme linked immunosorbent assay (ELISA) plates were coasted with two monkeypox virus peptides from B21R protein, to establish an indirect ELISA for detecting monkeypox virus IgG antibody. The healthy individuals serum samples, monkeypox virus infected patient serum samples and other virus infected patient sera samples were applied to evaluate specificity of the peptides antigen. The reaction conditions were optimized. Results: Synthesized two peptides from monkeypox virus BR21R protein did not cross react obviously with healthy person serum and other virus infected serum. It was shown that the reaction condition was best with sera dilution at 1∶50 when two combined peptides were coated at 100 ng /well, and second-antibody was diluted at 1∶20 000. At this condition the cut off value of IgG antibody in serum samples for ELISA were A450 reading of 0.393. The detected results of two serum samples collected from the monkeypox patient in Sierra Leone were strongly positive, the titers of IgG antibody in two sera were both 1∶6 400. Conclusions The indirect ELISA for detection of monkeypox virus infection was established preliminarily which provided useful tools for epidemiological study and diagnosis.

Objective: To prove the validity and accuracy of the digitizer instead of the conventional electronics plug-in for radionuclide measurement. Methods:  Based on a large-area flow-gas multi-wire proportional counter for 2πα and 2πβ surface particle emission rate measurement, the DT5730 digital waveform sampler developed by CAEN was used for waveform signal acquisition, amplitude analysis, and data processing of the α-plane source 241Am and the β-plane source nuclides 14C, 36Cl, and 90Sr-90Y of different energies. Results: The deviations between the α and β surface particle emission rate results obtained after dead time and background corrections and the measurements obtained based on the plug-in calibrator were all within 0.6%, within the uncertainty range, under consistent experimental conditions such as electronics threshold and high pressure. Conclusion The digitizer is an effective alternative to conventional electronics plug-ins for α and β signal acquisition and processing and the accurate measurement of α and β emission rates.

Temperature is one of the major environmental signals controlling plant development, geographical distribution, and seasonal behavior. Plants perceive adverse temperatures, such as high, low, and freezing temperatures, as stressful signals that can cause physiological defects and even death. As sessile organisms, plants have evolved sophisticated mechanisms to adapt to recurring stressful environments through changing gene expression or transcriptional reprogramming. Transcriptional memory refers to the ability of primed plants to remember previously experienced stress and acquire enhanced tolerance to similar or different stresses. Epigenetic modifications mediate transcriptional memory and play a key role in adapting to adverse temperatures. Understanding the mechanisms of the formation, maintenance, and resetting of stress-induced transcriptional memory will not only enable us to understand why there is a trade-off between plant defense and growth, but also provide a theoretical basis for generating stress-tolerant crops optimized for future climate change. In this review, we summarize recent advances in dissecting the mechanisms of plant transcriptional memory in response to adverse temperatures, based mainly on studies of the model plant

This corrects the article “Analysis of Tau Protein Expression in Predicting Pathological Complete Response to Neoadjuvant Chemotherapy in Different Molecular Subtypes of Breast Cancer” in volume 23 on page 47.This article was initially published on the Journal of Breast Cancer with a misspelled the abbreviation in figure 3. The abbreviation ‘HP’ should be corrected as ‘HR’.