Recently,a fast developing new technology for gene modification named as CRISPR-Cas9 which based on CRISPR-Cas9 system composed of clustered regulatory interspaced short palindromic repeat(CRISPR) and Cas9 nuclease(CRISPR associated system 9,Cas9)has been developed. CRISPR-Cas9 system is a kind of immune mechanism widely found in bacteria and archaea. This mechanism can help bacteria and archaea against exogenous DNA by the approach of specifically breaking DNA. Later,this mechanism was found to be useful for gene modification and gene deletion. At present,this technology has been applied to gene modification and therapy. Many studies have shown that the technology,compared with other genetic technology,has higher efficiency and accuracy,and it has promoted genetic engineering progress. Summarized here is the principle and application advance of CRISPR-Cas9.

Objective:To evaluate the acute oral toxicity , skin irritation and skin allergy of Thuja essential oil ( TEO) , and pro-vide experimental basis for the clinical use of TEO .Methods:The acute oral toxicity was measured by Horn ’ s assay .Totally 40 KM mice were divided into four groups and intragastrically administered with TEO at different dose of 21.50, 10.00, 4.64 and 2.15 g · kg-1 .After the 14-day observation, the death number and toxic manifestations were recorded and observed , and LD50 was calculated by checking the Horn's form of LD50 .The skin irritation test was performed on healthy adult white rabbits .Totally 9 rabbits were divid-ed into 3 groups randomly , and TEO at the concentration of 100%, 50%and 25%was painted on the skin of the rabbits .Edible vege-table oil was used as the negative control .The erythema and edema of the treated skin were evaluated and scored .Delayed skin hyper-sensitivity reaction was used to investigate the allergy of TEO .Totally 30 white guinea pigs were randomly divided into 3 groups:TEO group, the negative control (edible vegetable oil) and the positive group (1%2, 4-dinitrochlorobenzene).After the intracutaneous in-duction stage and local induction stage , TEO was used to activate the hypersensitive reaction .The skin response was observed and scored after the 24-hour and 48-hour activation.Results:The mice in 21.50 g · kg-1 TEO treatment group were all dead , while only a part of the mice in 10.00 and 4.64 g · kg-1 TEO treatment groups were dead , and no mice died in 2.15 g · kg-1 TEO treatment group.According to the Horn's form of LD50 , LD50 of TEO was 9.26 g · kg -1 for male mice and 7.94 g · kg -1 for female mice.The results of skin irritation test indicated the strong irritation effects of TEO .However , the irritation of TEO was reduced after the dilution , and 25%TEO showed no irritation to the skin of rabbits .The results of delayed skin hypersensitivity reaction showed obvious erythema and edema induced by 2, 4-dinitrochlorobenzene , while no obvious erythema and edema were found in TEO treated guinea pigs , indi-cating non-allergic effect of TEO .Conclusion:TEO has strong skin irritation in rabbits , while no obvious oral toxicity in mice and skin allergy in guinea pigs .

Objective: To evaluate the genetic toxicity of Thuja essential oil by salmonella reversion test (AMES test) and mammal micronucleus test.Methods: TA97, TA98, TA100 and TA102 were used in AMES test to evaluate the mutagenesis of Thuja essential oil.Mouse bone marrow micronucleus test was conducted to assess the chromosome toxicity of the drug.Results: Both in S9 present and absent situations, the numbers of reverse mutation of Thuja essential oil at different doses for the four strains were all less than 1-fold of that of solvent control, and the difference had no statistical significance (P>0.05), suggesting negative mutation.The micronucleus test indicated that Thuja essential oil had no influence on the rate of mouse bone marrow micronucleus (P>0.05).Conclusion: Thuja essential oil shows no obvious genetic toxicity.

Objectives To investigate the effects of ethanol on neural development and kainate receptor expression in young mice. Methods Fetal alcohol spectrum disorder model was established by administration of 20% ethanol solu?tion to 7-day-old Kunming mice and control animals received physiological saline (The number of treatment and control were 80 and 40, respectively ). Body weight and general biological features were observed every day. Morris water maze was used to test learning and memory ability. Fluoro-Jade B was used to examine neural cells 24 hours after treatment in additional thirty 7-day-old Kunming mice which were further divided into two groups:a treatment group receiving 20%ethanol solution (n=15) and a control group receiving physiological saline (n=15). The development of neural cells and expression levels of kainite receptors were examined by using immunofluorescence staining. Results The body weight was significantly lighter in treatment group than in control group(control:21.13 ± 1.72g,treatment:13.96 ± 2.98g,P<0.05). Morris test showed that model group had longer latency than control group to find hidden platform(control:21.05± 5.31s,treatment:34.15±3.26s,P<0.05). Spatial probe test revealed that the number of passing through the platform were significantly smaller in model group than in control group(control:2.70 ± 1.25 times,treatment:0.93 ± 0.80 times,P<0.05). Astrocyte development anomaly was evident after ethanol treatment for 7 days. The expression levels of kainite re?ceptor GluR-6 and KA2 were up-regulated in the CA region of the hippocampus after ethanol treatment for 7 days. Con?clusion Kainite receptor GluR-6 and KA2 in CA region of the hippocampus may contribute to ethanol-induced hippo?campal neural development anomaly.

Objective:To compare the effects of "Rain Classroom" teaching model and traditional teaching model in the Pharmacology teaching for MBBS international students.Methods:A total of 55 MBBS international students of the Batch 2016 were selected, and randomly divided into the "Rain Classroom" teaching group ( n = 27, experimental group) and the traditional teaching group ( n = 28, control group) according to their academic performance, age, gender, learning attitude, learning ability, and their original country. The experimental group took "Rain Classroom" assisted teaching, and control group took traditional teaching.The teachers for two groups were the same. They have been engaged in the "Pharmacology" course for international students for many years. The chapter "Antihypertensives" in textbook " Lippincott's Illustrated Reviews, Pharmacology (edited by Karen Whalen)" was selected as teaching content. The teaching effects were evaluated by the knowledge assessment (70 points) and process evaluation (30 points). A questionnaire survey was conducted at the end of the course. The results were statistically analyzed by t-test and Chi-square test using SPSS 11.5 software. Results:Compared with the traditional teaching group, the students of "Rain Classroom" group obtained a significantly higher score in exam. The average exam score of the "Rain Classroom" group was (58.6±6.8) points, while the average exam score of the traditional teaching group was (52.3±9.4) points, indicating a better mastery of knowledge for "Rain Classroom" group ( P < 0.05). The process evaluation showed that the students in the "Rain Classroom" group were more active in participation and the interaction, which was significantly higher than that in the traditional teaching group (7.4 vs. 2.8 times per students). No obvious difference was observed in students' attendance and homework scores for these two groups. According to the questionnaire survey, the "Rain Classroom" group enhanced students' interest in learning, improved the concentration in classes, and thus promoted the mastery of knowledge. Conclusion:The present study has confirmed the "Rain Classroom" teaching method is conducive to mobilizing students' enthusiasm for learning and improving teaching effect.

AIM: To identify the differentially expressed lncRNAs related to myelodysplastic syndromes by method of bioinformatics. METHODS: The GSE145733 was downloaded from GEO database; the differentially expressed lncRNAs were screened out by GEO2R. miRNA and mRNA associated with the differentially expressed lncRNAs were analyzed by the platform miRDB. lncRNA-miRNA-mRNA network was constructed and visualized by Cytoscape software. We annotated and enriched the lncRNAs to biological functions and pathways by GO and KEGG tools. RESULTS: Five differentially expressed lncRNAs were screened out. These lncRNAs were associated with 19 miRNAs and 84 mRNAs. They mainly affected the functions such as substance synthesis and transportation, gene transcription, and nervous system. CONCLUSION: We discovered the lncRNA expression characteristics in MDS patients, predicted the functions of these lncRNAs, which may provide new drug targets for the precise medication in MDS.