Objective To understand the effects of 17?-estradiol on MCF-7 cell proliferation and the regulation of estrogen receptor-related recepto(rERR?).Methods MCF-7 cells were treated with 17?-E2 at the doses of 10-12,10-11,10-10,10-9,10-8,10-7 and 10-6 mol/L for 24 h.Dimethyl sulfoxide were used as the solvent control.MTT method was used to determine inhibitory rate of MCF-7 proliferation,and the cells were treated with 17?-E2 at the doses of 10-10,10-9,10-8 and 10-7 mol/L for 24 h.RT-PCR method was used to detect the expression level of ERR?.Results Cell proliferation were promoted by exposure to 17?-E2 at the doses of 10-12,10-11,10-10,10-9,10-8,10-7 and 10-6 mol/L,the proliferation rate were 112.09%,122.09%,123.42%,120.46%,124.60% and 109.23% respectively,however,cell growth was inhibited at 10-6 mol/L of 17?-E2.The expression of ERR? in MCF-7 cells was upregulated at the doses of 10-10,10-9,10-8 and 10-7 mol/L when cells were treated with 17?-E2 for 24 h.Conclusion In certain dosage range,cell proliferation and expression of ERR? can be promoted by 17?-E2,which suggests that ERR? should play an important role in the process of MCF-7 cells growth.

目的探讨截肢后残疾人综合康复策略。方法个案分析。9岁女童,因车祸骨盆以下截肢。各学科专家和社会工作者组成康复团队,进行综合康复。结果4个月后,女童装上假肢,恢复清纯女孩的外观形象,学会使用假肢、轮椅或特制的小滑板代步,日常生活能力(ADL)提高,正常上学,成绩优秀;将来准备向残疾运动员方向发展。结论综合康复可以实现残疾人回归社会。

OBJECTIVETo observe the effects of dexamethasone on proliferation, differentiation and apoptosis of adult human osteoblasts in vitro.

METHODSIliac trabecular bone specimens were obtained from adult patients undergoing necessary surgery. After the bone pieces were digested with collagenase-trypsin, osteoblasts were released and incubated at 37 degrees C in a relative humidity of 95% and 5% CO2. Then, the cells were purified, and their passages were given DMEM-F12 and fetal bovine serum medium. Subsequently, 10(-8) mol/L dexamethasone was added into the culture medium to incubate the osteoblasts for three days, and the cells from control groups were incubated without any drugs. All cells were observed continually with phase contrast microscope and transmission electron microscope. Finally, apoptosis was detected by the use of terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL) and biochemical indices, alkaline phosphatase (ALP) and osteocalcin (OCN) were used to determine the effects of dexamethasone on proliferation, differentiation and apoptosis of adult osteoblasts in vitro.

RESULTSIn the adult osteoblasts obtained by collagenase-trypsin digestion, it achieved high survival, stable biochemical indices and excellent purification. Under the condition of dexamethasone 10(-8) mol/L and osteoblasts 10,000/ml, there was significant promotion of ALP and OCN secretion without cell apoptosis.

CONCLUSIONSDexamethasone has a significant effect on the proliferation and differentiation of adult osteoblasts in vitro without apoptosis, and dexamethasone at the suggested concentration can be used as positive control in drug studies for osteoporosis treatment.

Adult ; Apoptosis ; drug effects ; Cell Differentiation ; drug effects ; Cell Division ; drug effects ; Cells, Cultured ; Dexamethasone ; pharmacology ; Humans ; In Situ Nick-End Labeling ; Osteoblasts ; cytology ; drug effects

A new wave of research has been inspired by the CRISPR-Cas system with respect to their application in genome editing. The CRISPR-Cas system can not only be applied in gene knockout and insertion, but also be used in base editing, transcriptional regulation and recombination of gene clusters. However, the low efficiency of homology-directed repair (HDR) limits its application. Unlike the CRISPR-Cas system, mobile genetic elements (MGE) can insert DNA fragments into cell chromosomes without the aid of HDR. Recently, it is reported that CRISPR-related transposable elements can guide targeted DNA insertion. Their transposition mechanisms and reprogramming abilities have brought novel opportunities to the development of this field. This review summarized the research progress and application development of natural CRISPR-related transposable elements in recent years, as well as the applications of fused dCas9-transposase. It proposed the application prospects and potential challenges of CRISPR-related transposable elements in the future, which provided a reference for the development direction of gene editing tools.
DNA Transposable Elements/genetics* ; Gene Editing ; CRISPR-Cas Systems/genetics*