Human 8-cell embryos enable efficient induction of disease-preventive mutations without off-target effect by cytosine base editor

Approximately 140 million people worldwide are homozygous carriers of APOE4 (ε4), a strong genetic risk factor for late onset familial and sporadic Alzheimer's disease (AD), 91% of whom will develop AD at earlier age than heterozygous carriers and noncarriers. Susceptibility to AD could be reduced by targeted editing of APOE4, but a technical basis for controlling the off-target effects of base editors is necessary to develop low-risk personalized gene therapies. Here, we first screened eight cytosine base editor variants at four injection stages (from 1- to 8-cell stage), and found that FNLS-YE1 variant in 8-cell embryos achieved the comparable base conversion rate (up to 100%) with the lowest bystander effects. In particular, 80% of AD-susceptible ε4 allele copies were converted to the AD-neutral ε3 allele in human ε4-carrying embryos. Stringent control measures combined with targeted deep sequencing, whole genome sequencing, and RNA sequencing showed no DNA or RNA off-target events in FNLS-YE1-treated human embryos or their derived stem cells. Furthermore, base editing with FNLS-YE1 showed no effects on embryo development to the blastocyst stage. Finally, we also demonstrated FNLS-YE1 could introduce known protective variants in human embryos to potentially reduce human susceptivity to systemic lupus erythematosus and familial hypercholesterolemia. Our study therefore suggests that base editing with FNLS-YE1 can efficiently and safely introduce known preventive variants in 8-cell human embryos, a potential approach for reducing human susceptibility to AD or other genetic diseases.

Application of multiple teaching method in practice teaching of bone marrow cell morphology / 中华医学教育探索杂志

Bone marrow cell morphology is the important part of the course of clinical hema-tology and laboratory and is the difficult and key part in the practice teaching of this course. In order to let students better grasp the basic skills, teachers should flexibly use multiple teaching methods of comparison type, communication type, heuristic type, medical record type and PBL type, which will greatly improve the teaching quality of hematology practice teaching.

Application of microscopic digital interactive system in bone marrow cell morphology practice teaching / 中华医学教育探索杂志

Bone marrow cell morphology is an important part of clinical hematology and laboratory and is the key and difficult part of teaching.Microscopic digital interactive system consisting of image processing and analyzing software,voice response software and computer teaching software can realize the picture resources sharing,effective teacher-student interaction and change of evaluation mechanism.The application of this system changed the traditional modes of teaching; motivated students' enthusiasm and greatly improved the quality of practice teaching.

Polysorbate-80 modified neurotoxin nanoparticle with its transport and cytotoxicity against blood-brain barrier / 药学学报

This study was aimed at the transport across blood-brain barrier (BBB) of polysorbate-80 modified neurotoxin loaded polybutylcyanoacrylate nanoparticle (P-80-NT-NP) and its cytotoxicity. An in vitro model of BBB using rat brain microvascular endothelial cells (rBMECs) was established. The cytotoxicity of P-80-NT-NP was measured by the MTT assays, where neurotoxin (NT), nanoparticle (NP), neurotoxin nanoparticle (NT-NP) as control, and the permeability of P-80-NT-NP was determined by using of Millicell insert coculture with rBMECs and fluorescence spectrophotometry. MTT results showed that NT, NP, NT-NP and P-80-NT-NP were avirulent to rBMECs when the concentration of NT was lower than 200 ng x mL(-1). But the cytotoxicity of NP, NT-NP and P-80-NT-NP would be augmented accordingly as concentration increased (P 0.05). When the concentration of NT was 150 ng x mL(-1), the permeability on rBMECs of P-80-NT-NP and NT-NP were both significantly higher than that of NT (P < 0.01), and the permeability of P-80-NT-NP was greater than that of NT-NP (P < 0.05). In conclusion, polysorbate-80 modified neurotoxin nanoparticles can transport across the BBB, while concentration of NT is greater than 200 ng x mL(-1), P-80-NT-NP has a little cytotoxicity against rBMECs.

Analysis on the metabolites of mesaconitine in the rat urine by liquid chromatography and electrospray ionization mass spectrometry / 药学学报

The mesaconitine and its major metabolites in the rat urine were identified by liquid chromatography and electrospray ionization tandem mass spectrometry. The rat urine was collected for consecutive 24 hours from the rat following intragastric infusion of mesaconitine, subsequently which were enriched and purified using solid phase extraction. The metabolites of mesaconitine in the rat urine were analyzed by the liquid chromatography and electrospray ionization tandem mass spectrometry. It is shown that the parent drug mesaconitine and its metabolites were found in the rat urine, such as hypo-mesaconitine glucuronic acid conjugate, 10-hydroxy-mesaconitine, 1-O-demethyl mesaconitine, deoxy-mesaconitine and hypo-mesaconitine. Among the five of metabolites, the hypo-mesaconitine glucuronic acid conjugate (m/z 766) was first discovered as the aconitine in rats phase II metabolites, which revealed a new way of mesaconitine metabolism in rats.

Acute Leukemia Patients with Complication of Infection:Their Clinical Features / 中华医院感染学杂志

OBJECTIVE To study the clinical features of acute leukemia(AL) patients with complication of infection. METHODS A retrospective analysis of prevalence of infection occurring in 123 AL patients,their bacterial spectrum,and the effect of G-CSF on the infection were done. RESULTS The prevalence of infection in AL patients was 94.3%,among which 49.2% were infected with Gram-positive organisms,42.4% with Gram-negative bacilli and 8.4% with fungi.Blood culture occurred mostly with Escherichia coli and Pseudomonas infection.Patient′s neutropenia was significantly related to the infection.The patients with neutrophil count less than 0.2?10~9/L had more frequently suffered severe infection with long-lasting time,and had more than two sites of infection.Age,hemoglobin level,prophylactic intestinal usage of antibiotics could not reduce patient′s infection.The total mortality of AL patients with infection was 6%.Pulmonary infection and septicemia increased mortality,but G-CSF therapy reduced it. CONCLUSIONS AL patients are at high risk of infection which is significantly associated with severe neutropenia.G-CSF therapy exerts an assistant role to antibiotics in controlling the infection.

The exploration of antibiotic therapy in neutropenic hematological maligence patients / 中国基层医药

Objective To compare the efficiency and safety of regimens of empiric antibiotic therapy in neutropenic hematological maligence patients.Methods The clinical data of empiric antibiotic therapy for 260 febrile episodes in 125 neutropenic hematological maligence patients were analyzed retrospectively.Results A total of 45 febrile episodes were treated with tazocin plus amikacin(regimen TA).80 episodes were treated with ceftazidime plus amikacin(regimen CA),75 episodes with imipenem plus amikacin(regimen IA) and 60 episodes with maxipime plus amikacin(regimen MA).The medians of initial therapy in each regimen were 7～8 days.Percentage of satisfactory response had no significant difference in episodes treated with regimens TA,IA and MA(65%,70% and 79% respectively),and it was better than regimen CA(P

Preparation and evaluation of silymarin supersaturation self-emulsifying drug delivery system / 中草药

Objective To prepare the supersaturation self-emulsifying drug delivery system(S-SEDDS) containing silymarin and to evaluate its basic properties.Methods With the time of self-emulsifying,the consequence of color visual examination and particle size as parameters,the optimum formulations of silymarin SSEDDS were screened by solubility test,compatibility tests and pseudo ternary phase diagrams.The silymarin concentration was determined by HPLC.The in vitro dissolution characteristics of silymarin S-SEDDS were investigated with silymarin SEDDS as control.Results The optimum silymarin S-SEDDS was composed of medium chain triglycerides(MCT) 40%,Cremophor RH40(ethoxylated hydrogenatedcastor oil) 48%,Labrasol 12%.The time of self-emulsifying was less than 3 min,the average particle diameter was 49.6 nm,the adding amount of hydroxypropyl methylcellulose(HPMC) was 50 mg/g,and the average content of silymarin was 39.3 mg/g.The in vitro dissolution test of silymarin S-SEDDS showed that the presence of a small amount of cellulosic polymer effectively sustained a metastable supersaturated state by retarding precipitation kinetics.Conclusion The designed formulation of silymarin S-SEDDS is reasonable and provides a strong foundation for further development of new preparations.

Quality standard of Shengxue Micro Capsules / 中成药

AIM:To establish the quality standard for Shengxue Micro Capsules(melanteritum,Cortex Cinnamo-(mi,) Endoconcha Sepiae,Colla Corii asini,Placenta Hominis). METHODS: The melanteritum,Endoconcha sepiae was identified by physic-chemical analysis. Cortex Cinnamomi was identified by TLC.UV was employed for the assay of FeSO_4.GC was used to determine Cinnamaldehyde of Shengxue Micro Capsules. RESULTS: Green vitriol,Endoconcha sepiae could be identified by physico-chemical analysis.Cortex Cinnamomi could be identified by TLC.The linear range of FeSO_4 was within 0～20 mg,r = 0.999 8;The average recovery of assay was(96.7%.) The linear range of cinnamaldehyde was within 0.157 5～0.551 4 ?g,r = 0.999 8;The average(recovery) of assay was 101.52%. CONCLUSION: The method is simple, reproducible.It could be used for(quality) control of Shengxue Micro Capsules.

Effect of Shenmai Injection on the expression of bFGF and PCNA in tumor / 中成药

AIM: To investigate the effect of Shenmai Injection on the expression of bFGF and PCNA of gastric cancer in mouse. METHODS: RT-PCR was used to measure the expression of bFGF and PCNA in gastric cancer cell cultured with Shenmai Injection in three concentrations.immunohistochemistry used for protein synthesis in mouse gastric cancer model. RESULTS: 140 ?L/mL of Shenmai Injection concentration inhibited 63% of bFGF and PCNA gene expression. CONCLUSION: Shenmai Injection can inhibit the express of bFGF and PCNA.