The imbalance of lipid metabolism is an important factor causing a series of metabolic diseases such as non-alcoholic fatty liver disease (NAFLD) and hyperlipidemia.Liver X receptors is a member of the nuclear receptor superfamily, which maintains cholesterol homeostasis by regulating cholesterol absorption, transport, reverse cholesterol transport, biosynthesis and other functions.It plays an important role in maintaining lipid homeostasis by regulating de novo fat synthesis to maintain the balance of fatty acids in the body.

Objective To investigate the effect of erythropoietin(EPO)on the proliferation of neural stem cells(NSCs)derived from central canal of adult rat spinal cord in vitro ,so as to provide a theoretical basis for clinical treatment of spinal cord injury by autotransplanting or allograft transplanting of adult spinal cord NSCs. Method NSCs were isolated from the central canal of the adult rats spinal cord by microsurgical method,and Nestin(nestin)and Sox2 immunofluorescence stain were used to identify the cells. After cells were treated with different dose of EPO,5,10,20 and 40 U/mL,respectively,the optical treatment concentration and time were determined by CCK8 assay. The effect of EPO on the cell count and the expression of Cyclin D1 in NSCs were detected at the treatment time 96 h. Result The NSCs derived from the central canal of adult SD rats spinal cord could stably express protein Nestin and transcription factor Sox2. As the results of CCK8 test,cell counts and real-time quantitative PCR showed the optimal treatment of concentration and time maybe 20 U/mL and 96 h. Conclusions This study shows that EPO can promote the proliferation of NSCs derived from central canal of adult rat spinal cord,and the optimal treatment of concentration and time for proliferation might be 20 U/mL and 96 h.

Objective: To evaluate the value of T2WI signal intensity related parameters that can be obtained by magnetic resonance imaging (MRI) for predicting pathological complete response (pCR) after neoadjuvant chemoradiotherapy (nCRT) in patients with locally advanved rectal cancer (LARC). Methods: Signal Intensity of Tumor (SIT) and Signal Intensity of Tumor/Muscle (SIT/M) of MR T2WI before and after neoadjuvant chemoradiotherapy of 101 patients with locally advanced rectal cancer were evaluated by two experienced readers independently. Signal Intensity of Tumor Reduction Rate (SITRR) and Signal Intensity of Tumor/Muscle Reduction Rate (SIT/MRR) were calculated. The difference of related parameters of T2WI tumor signal intensity between the pCR and the non-pCR group were analyzed. Receiver operating characteristic (ROC) analysis was used to assess the diagnostic performance for predicting pCR. Results: Of the 101 patients, 18 were in pCR group and 83 were in non-pCR group. In all patients, the SITpre, SITpost, SITRR, SIT/Mpre, SIT/Mpost and SIT/MRR measured by reader 1 were 197.0 (133.0), 144.2 (69.7), 0.4% (0.5%), 2.6 (0.6), 3.0 (2.3) and 0.4 (0.2)% in pCR group, and 227.0 (99.0), 205 (95.4), 0.1% (0.6%), 2.6 (0.6), 2.6 (1) in non-pCR group, respectively. SITpre, SITpost, SITRR, SIT/Mpre, SIT/Mpost and SIT/MRR measured by reader 2 were 193.0 (135.0), 143.0 (69.8), 0.4% (0.2%), 2.6 (0.6), 1.5 (0.5) and 0.39% (0.2%) in pCR group, and 234.0(108.0), 203(96.5), 0.1% (0.3%), 2.6 (0.6%), 1.7 (0.7) and 0.25% (0.2%) in non-pCR group, respectively. Between the pCR and non-pCR group, there were significant differences in SITpost, SIT/Mpost and SIT/MRR measured by both readers (all P<0.01), but there was no significant differences in SITpre and SIT/Mpre (P>0.05). The difference of SITRR measured by reader 1 was not statistically significant (P=0.415), while the difference of SITRR measured by reader 2 was statistically significant (P=0.001). In patients with rectal non-mucinous adenocarcinoma, SITpost, SIT/Mpost, SITRR and SIT/MRR measured by two physicians were still statistically significant between the pCR and non-pCR group (all P<0.01), but SITpre and SIT/Mpre had no significant difference (P>0.05). ROC curve analysis showed that in all patients, the area under curve (AUC) of SITpost, SIT/Mpost and SIT/MRR for predicting pCR to neoadjuvant chemoradiotherapy in locally advanced rectal cancer was 0.694-0.762, the sensitivity was 68.2%-77.3%, and the specificity was 63.6%-77.3%. In rectal non-mucinous adenocarcinoma patients, the AUC, sensitivity and specificity was 0.704-0.764, 62.7%-78.9% and 66.2%-84.2%, respectively. Conclusions T2WI signal intensity related parameters are potential predictors for pCR in locally advanced rectal cancer after neoadjuvant chemoradiptherapy. The predictive value is higher in non-mucinous adenocarcinoma.

Objective To evaluate the value of MRI texture analysis (TA) in prediction of treatment response neoadjuvant chemoradiotherapy (nCRT) in locally advanced rectal cancer patients. Methods Fifty nine histopathologically-proven rectal adenocarcinoma patients through biopsy treated with nCRT before total mesorectal excision were enrolled in this retrospective study.The first MRI examination (pre-nCRT MRI)was performed before nCRT,and the second one(early nCRT MRI)was performed at the third week of nCRT. The texture parameters values were measured, including mean value, standard deviation, skewness, kurtosis, uniformity, energy, and entropy. Tumoral downstaging was determined by comparing the pre-nCRT clinical T stage(cT stage) with the ypT stage. The patients were divided into downstaging and non downstaging group based on postoperative T staging. Parameters were compared between pre-and early nCRT in terms of averages using Wilcoxon signed-rank test. Downstaging and non downstaging groups were analyzed using Mann-Whitney U test.Multivariate logistic regression analysis was performed using the statistically significant parameters between the two groups as independent variables. ROC analysis was performed on the new independent variables obtained by multi-parameter logistic regression analysis and the single parameter independent variables. The diagnostic efficiency of the parameters were evaluated. Results T-downstaging were found in 28 patients after nCRT. The stdDeviation, kurtosis, and uniformity were significantly different between pre-and early nCRT (P<0.05). There was no significant difference in mean value, skewness, energy, and entropy between pre-and early nCRT (P>0.05). The pre-nCRT, uniformity, energy, entropy and the early nCRT mean value, entropy were significantly different in patients with downstaging vs. non downstaging (P<0.05). For the pre-nCRT stdDeviation,uniformity,energy,entropy and the early nCRT mean value,entropy,ROC analysis showed an area under curve(AUC) of 0.69, 0.76, 0.68, 0.67 and 0.65, 0.68, respectively. The multivariate logistic regression analysis for the four pre-nCRT independent variables(stdDeviation,uniformity,energy,entropy) achieved logical variable 1,and the logical variable 1 achieved an AUC of 0.78 to discriminate patients with T-downstaging from patients with non downstaging.The multivariate logistic regression analysis for the two early nCRT independent variables(mean value,entropy)achieved logical variable 2,and the logical variable 2 achieved an AUC of 0.69 to predict T-downstaging.Conclusion Pre-and early nCRT MRI TA in rectal cancer have the efficacy to predict treatment response.

Objective To compare the predictive value of radiomics signature extracted from MRI plain and enhancement sequence for the disease-free survival (DFS) of rectal cancer. Methods We retrospectively analyzed fifty-one patients with rectal adenocarcinoma confirmed by biopsy from October 2010 to December 2013 in Cancer Hospital Chinese Academy of Medical Sciences.All patients underwent neoadjuvant chemotherapy(nCRT)followed total mesorectal excision(TME),and MRI scans were performed before nCRT.Follow-up time for the survival patients were more than 3 years.The image segmentation was performed on the T2WI sequence of the small FOV and the multi-phase enhancement sequence venous phase,respectively.Least absolute shrinkage and selection operator(LASSO)Cox regression was applied to extract radiomics features and the imaging signature was constructed. According to the radiomics score of each patient,the patients were divided into the high risk group with shorter DFS and the low risk group with longer DFS. A 3-year DFS was calculated for radiomics signature using the Kaplan-Meier product limit method with univariate log-rank analysis testing for differences in the training and validation cohort, respectively. And the predictive ability of the model was evaluated by concordance index (C-index). Results The training set and the validation set were 36 and 15 cases, respectively. During follow-up 32 patients experienced relapse(26 distant,3 local and 3 both),and 19 cases were censored.Twelve features were extracted in the enhanced sequence.The radiomics signatures were significant for DFS in the training set and the validation set(P=0.000 2 and 0.009 1,respectively).The C-index of the model were 0.904 and 0.700 in the training set and the validation set, respectively. The model has the better ability to predict survival.Two features were extracted in the plain sequence.The radiomic signature was significant for DFS in the training set(P=0.005 0),while the radiomics signature was not significant for DFS in the validation set (P=0.767 0). The C-index of the model were 0.711 and 0.500 in the training set and the validation set, respectively.Conclusions Radiomics signature extracted from MRI venous phase enhancement sequence superior to plain sequence for predicting the DFS of rectal cancer before nCRT.

Objective To compare the diagnostic value of T2 weighted imaging ( T2WI) , diffusion?weighted imaging ( DWI) , and T2WI+DWI magnetic resonance imaging ( MRI) for staging of rectal cancers for improving the accuracy of tumor staging. Methods From January 2011 to December 2013, 120 cases of rectal cancers proved by colonoscopy without receiving any anti?tumor treatment were enrolled retrospectively. The MRI data for these patients were divided into three groups, ie., T2WI, DWI and T2WI+DWI, for evaluating the tumor stages. The results were compared with histopathologic findings. The sensitivity and specificity were calculated and compared with chi?square test. The nodal staging was predicted by using T2WI+DWI. Results The accuracy for prediction of tumor staging was 83. 3％, 65. 0％ and 92. 5％ for T2WI, DWI, and T2WI+DWI respectively. The specificity for evaluating T1 and T2 stage, and the sensitivity for evaluating T3 by DWI was significantly lower than those using T2WI and T2WI+DWI in rectal cancers. The sensitivity for evaluation of T2 by DWI was lower than that using T2WI+DWI ( 63. 0％ vs. 88.9％) . The sensitivity for evaluation T2 and specificity for T3 by T2WI+DWI was higher than thouse using T2WI only (88.9％ vs. 51.9％, 94.0％ vs. 72.0％). The accuracy for prediction of nodal staging by using T2WI+DWI was 62.1％ ( 72/116) . Conclusions T2WI is the key sequence for staging of rectal cancers. Although the diagnostic accuracy was not good by using DWI alone, the combination of T2WI and DWI can improve the accuracy significantly for tumor staging in rectal cancers, whereas the nodal staging was still a hard task for radiologists.

Objective To compare the diagnostic value of T2 weighted imaging ( T2WI) , diffusion?weighted imaging ( DWI) , and T2WI+DWI magnetic resonance imaging ( MRI) for staging of rectal cancers for improving the accuracy of tumor staging. Methods From January 2011 to December 2013, 120 cases of rectal cancers proved by colonoscopy without receiving any anti?tumor treatment were enrolled retrospectively. The MRI data for these patients were divided into three groups, ie., T2WI, DWI and T2WI+DWI, for evaluating the tumor stages. The results were compared with histopathologic findings. The sensitivity and specificity were calculated and compared with chi?square test. The nodal staging was predicted by using T2WI+DWI. Results The accuracy for prediction of tumor staging was 83. 3％, 65. 0％ and 92. 5％ for T2WI, DWI, and T2WI+DWI respectively. The specificity for evaluating T1 and T2 stage, and the sensitivity for evaluating T3 by DWI was significantly lower than those using T2WI and T2WI+DWI in rectal cancers. The sensitivity for evaluation of T2 by DWI was lower than that using T2WI+DWI ( 63. 0％ vs. 88.9％) . The sensitivity for evaluation T2 and specificity for T3 by T2WI+DWI was higher than thouse using T2WI only (88.9％ vs. 51.9％, 94.0％ vs. 72.0％). The accuracy for prediction of nodal staging by using T2WI+DWI was 62.1％ ( 72/116) . Conclusions T2WI is the key sequence for staging of rectal cancers. Although the diagnostic accuracy was not good by using DWI alone, the combination of T2WI and DWI can improve the accuracy significantly for tumor staging in rectal cancers, whereas the nodal staging was still a hard task for radiologists.

With the rapid changes in lifestyle, natural and social environment, the reproductive health status of couples in childbearing age continues to decline, and long-term outcomes of the rapidly increasing offspring conceived by assisted reproductive technology (ART) needs to be evaluated urgently. Therefore, the focus of research now needs to be extended from death and severe diseases to full life cycle and full disease spectrum. In order to meet the demand for such research, we launched the China National Birth Cohort (CNBC) study, an ongoing prospective and longitudinal study aiming to recruit 30 000 families underwent ART and 30 000 families with spontaneous pregnancies. Long-term follow-up programs will be conducted for both spouses and their offspring. Data of couples and their offspring, such as environmental exposure, reproductive history, psychological and behavioral status, will be collected during follow-up. Peripheral blood, urine, umbilical blood, follicular fluid, semen were also collected at different follow-up nodes. Based on high-quality data and biological samples, CNBC will play an extremely important supporting role and have a far-reaching impact on maternal and children's health care and reproductive health in China. This paper is exactly a brief introduction to the construction and basic design of CNBC.

Birth cohort is an effective method to explore the relationship between various prepregnant and pregnant exposures and the health of fetuses, infants and young children. It is a long construction period to build a birth cohort and the quality of research may be affected by many factors. This paper reviews the quality assurance and quality control measures in the process of China National Birth Cohort (CNBC), and summarizes the construction experience. We aim to provide experience for related cohort studies, which could improve the quality of cohort studies through removing the impact of related factors. CNBC adopted a series of measures to ensure the quality of research in the top-level design of quality assurance, including screening research center, developing member management system, formulating standard operating procedures and training staff by it. In terms of quality control, it includes real-time, timely and timing quality control for the process of data generation, full-cycle quality control for biological sample collection, processing, storage and comprehensive three-dimensional quality control for staff training, supervision and quantitative assessment.

Objective:To explore the effects of environmental, genetic factors as well as the interactions in early life on the short-term and long-term health of offspring and to systematically evaluate the pregnancy outcomes and health of offspring after birth between families with assisted reproductive technology (ART) conception and families with spontaneous conception.Methods:The China National Birth Cohort (CNBC), a multicenter prospective birth cohort study, includes both families with ART conception and families with spontaneous conception. Since 2016, CNBC has recruited families from 24 hospitals located in 12 provinces, municipalities and autonomous regions throughout China. Information and biospecimens were collected before ART treatment, embryo transfer, at early, second, third trimester and delivery, and at 42 days, 6, 12 and 36 months after birth.Results:By June 2020, CNBC had included 27 044 families with ART conception and 29 589 families with spontaneous conception. The majority of the participants are urban residents. Among the families with ART conception, 65.5% of the men and 63.7% of the women had college degrees or higher. The mean age distribution of men and women was (33.83±5.52) and (32.38±4.67) years. 83.2% of women were primiparas, and the prevalence rates of current regular smokers and current alcohol drinkers were 0.8% and 2.1% in women. Among the families with spontaneous conception, 81.5% of the men and 86.5% of the women had college degrees or higher. The mean age distribution of men and women was (32.06±5.09) and (30.40±4.27) years. 67.2% of women were primiparas, and the prevalence rates of current regular smokers and current alcohol drinkers were 0.1% and 2.2% in women. The baseline characteristics were different between the families with ART conception and spontaneous conception in different regions.Conclusion:CNBC provides a powerful and rich resource in studying the impact of genetic, environmental factors and interactions in early life and ART treatment on the health of offspring after birth.