Objective:To examine the associations of BMI and waist circumference (WC) with the risk of chronic kidney disease (CKD) and its subtypes in adults in China.Methods:The data from the China Kadoorie Biobank were used. After excluding those with cancer, coronary heart disease, stroke, or CKD at baseline survey, 480 430 participants were included in this study. Their body height and weight, and WC were measured at baseline survey. Total CKD was defined as diabetic kidney disease (DKD), hypertensive nephropathy (HTN), glomerulonephritis (GN), chronic tubulointerstitial nephritis (CTIN), obstructive nephropathy (ON), CKD due to other causes, and chronic kidney failure. Cox proportional hazards regression model was used to estimate the associations between exposure factors and risks of outcomes.Results:During a follow-up period of (11.8±2.2) years, 5 486 cases of total CKD were identified, including 1 147 cases of DKD, 340 cases of HTN, 1 458 cases of GN, 460 cases of CTIN, 598 cases of ON, 418 cases of CKD due to other causes, and 1 065 cases of chronic kidney failure. After adjusting for socio-demographic factors, lifestyle factors, baseline prevalence of hypertension and diabetes, and WC and compared to participants with normal BMI (18.5-23.9 kg/m 2), the hazard ratios ( HRs) of total CKD for underweight (<18.5 kg/m 2), overweight (24.0-27.9 kg/m 2), and obese (≥28.0 kg/m 2) were 1.42 (95% CI: 1.23-1.63), 1.00 (95% CI: 0.93-1.08) and 0.98 (95% CI: 0.87-1.10), respectively. Stratification analysis by WC showed that BMI was negatively associated with risk for total CKD in non-central obese participants (WC: <85.0 cm in men and <80.0 cm in women) ( HR=0.97, 95% CI: 0.96-0.99), while the association was positive in central obese participants (≥90.0 cm in men and ≥85.0 cm in women) ( HR=1.03, 95% CI: 1.01-1.05). The association between BMI and GN was similar to that of total CKD. BMI was associated with an increased risk for HTN, with a HR of 1.12 (95% CI: 1.06-1.18) per 1.0 kg/m 2 higher BMI. After adjusting for potential confounders and BMI, compared to participants with non-central obesity, the HRs for pre-central obesity (WC: 85.0-89.9 cm in men and 80.0-84.9 in women) and central obesity were 1.26 (95% CI: 1.16-1.36) and 1.32 (95% CI: 1.20-1.45), respectively. With the exception of HTN and CTIN, WC was positively associated with risks for all CKD subtypes. Conclusions:BMI-defined underweight and central obesity were independent risk factors for total CKD, and BMI and WC had different associations with risks for disease subtypes.

Objective:To investigate the evaluation efficacy and predictive prognostic value of alpha-fetoprotein (AFP) response in tyrosine kinase inhibitors (TKIs) in combination with PD-1 inhibitors (α-PD-1) for intermediate-to-advanced hepatocellular carcinoma (HCC).Methods:The retrospective cohort study was conducted. The clinicopathological data of 205 patients with intermediate-to-advanced HCC who were admitted to 9 medical centers, including Mengchao Hepatobiliary Hospital of Fujian Medical University et al, from March 2020 to July 2022 were collected. There were 178 males and 27 females, aged (52±12)years. Based on AFP response at 6-8 weeks after treatment, patients were divided into the AFP response group (AFP level decreased by ≥50% compared to baseline) and the AFP no response group (AFP level decreased by <50% compared to baseline). Observation indicators: (1) AFP response evaluation of anti-tumor efficacy; (2) comparison of patient prognosis; (3) analysis of factors affecting patient prognosis. Measurement data with normal distrubution were represented as Mean± SD, and measurement data with skewed distribution were represented as M(range) and M( Q1, Q3). Count data were described as absolute numbers, and comparison between groups was conducted using the chi-square test. The Kaplan-Meier method was used to draw survival curve and calculate survival rate, and the Log-Rank test was used for survival analysis. The COX proportional risk model was used for univariate analysis and the COX stepwise regression model was used for multivariate analysis. Results:(1) AFP response evaluation of anti-tumor efficacy. Before treatment, all 205 patients were positive of AFP, with a baseline AFP level of 1 560(219,3 400)μg/L. All 205 patients were treated with TKIs in combination with α-PD-1, and the AFP level was 776(66,2 000)μg/L after 6 to 8 weeks of treatment. Of the 205 patients, 88 cases were classified as AFP response and 117 cases were classified as AFP no response. According to the response evaluation criteria in solid tumors version 1.1, the objective response rate (ORR) and disease control rate (DCR) were 42.05%(37/88) and 94.32%(83/88) in patients of the AFP response group and 16.24% (19/117) and 64.10% (75/117) in patients of the AFP no response group, showing significant differences between them ( χ2=16.846, 25.950, P<0.05). According to the modified response evaluation criteria in solid tumors, the ORR and DCR were 69.32% (61/88) and 94.32% (83/88) in patients of the AFP response group and 33.33% (39/117) and 64.10% (75/117) in patients of the AFP no response group, showing significant differences between them ( χ2=26.030, 25.950, P<0.05). (2) Comparison of patient prognosis. All 205 patients were followed up for 12.4(range, 2.4-34.0)months after treatment. The median progression free survival time and total survival time were 5.5 months and 17.8 months, respectively. The 1-year, 2-year progression free survival rates were 20.8% and 7.2%, and the 1-year, 2-year overall survival rates were 68.7% and 31.5%, respectively. The median progression free survival time, 1-year and 2-year progression free survival rates were 9.7 months, 39.6% and 14.2% in patients of the AFP response group and 3.7 months, 7.8% and 2.0% in patients of the AFP no response group, showing a significant difference in progression free survival between them ( χ2=43.154, P<0.05). The median overall survival time, 1-year and 2-year overall survival rates were not reached, 85.2% and 56.3% in patients of the AFP response group and 14.6 months, 56.3% and 14.5% in patients of the AFP no response group, showing a significant difference in overall survival between them ( χ2=33.899, P<0.05). (3) Analysis of factors affecting patient prognosis. Results of multivariate analysis showed that invasion of large blood vessels, extrahepatic metastasis, combined hepatic artery intervention therapy, and AFP response were independent factors influencing progression free survival in patients with intermediate-to-advanced HCC who were treated with TKIs in combination with α-PD-1 ( hazard ratio=1.474, 1.584, 0.631, 0.367, 95% confidence interval as 1.069-2.033, 1.159-2.167, 0.446-0.893, 0.261-0.516, P<0.05), and Eastern Cooperative Oncology Group score, invasion of large blood vessels, extrahepatic metastasis, and AFP response were independent factors influencing overall survival in patients with intermediate-to-advanced HCC who were treated with TKIs in combination with α-PD-1 ( hazard ratio= 1.347, 1.914, 1.673, 0.312, 95% confidence interval as 1.041-1.742, 1.293-2.833, 1.141-2.454, 0.197-0.492, P<0.05). Conclusions:AFP response at 6-8 weeks after treatment can effectively evaluate anti-tumor efficacy of TKIs in combination with α-PD-1 for intermediate-to-advanced HCC. AFP response is the independent factor influencing progression free survival and overall survival in patients with intermediate-to-advanced HCC who were treated with TKIs in combination with α-PD-1.

Objective:To characterize the distribution characteristics of choroidal thickness in healthy normal subjects and to define the diagnostic cut-off value for pachychoroid.Methods:A cross-sectional study design was carried out.Four hundred and forty-six eyes of 230 healthy subjects from the pachychoroid disease spectrum (PCD) cohort in Beijing Tongren Hospital from April 2018 to June 2021, were enrolled for the choroidal thickness distribution analysis.Three hundred and fourteen eyes of 274 patients with PCD including 149 eyes of 113 patients with central serous chorioretinopathy, 95 eyes of 81 patients with polypoid choroidal vasculopathy, 70 eyes of 60 patients with neovascular age-related macular degeneration, along with 382 eyes of 199 normal subjects matched for refractive error, age and gender with PCD were selected for likelihood ratio analysis.Routine eye examinations including the best corrected visual acuity, intraocular pressure, slit-lamp microscopy, dilated fundus examination and color fundus photography were performed in all subjects.Swept-source optical coherence tomography (SS-OCT) of 9 mm×9 mm scanning mode was used to measure the subfoveal choroidal thickness (SFCT) automatically in nine macular regions according to the Early Treatment Diabetic Retinopathy Study classification system using TOPCON Advanced Boundary Segmentation (TABS) software.Pearson linear correlation analysis and Spearman rank correlation analysis were adopted to evaluate the correlations between SFCT and age, diopter.Multiple linear regression was employed to analyze the factors affecting SFCT.After age and refractive error adjustment, the likelihood ratio test was used to determine the diagnostic cut-off value for pachychoroid.This study adhered to the Declaration of Helsinki.The study protocol was approved by an Ethics Committee of Beijing Tongren Hospital (No.TRECKY2016-054). Written informed consent was obtained from each subject prior to entering the cohort.Results:A negative correlation was found between SFCT and age in normal eyes ( r=-0.34, P<0.001), in both normal male and female subjects ( r=-0.43, P<0.001; r=-0.38; P<0.001). A weak positive correlation was found between SFCT and diopter ( rs=0.19, P<0.001). It was found that age and diopter were strongly correlated with SFCT (both at P<0.001). The cut-off values for pachychoroid in 20-39 years group, 40-59 years group, 60-79 years group and ≥80 years group were 320-330 μm, 330-340 μm, 250-275 μm and 200-225 μm, respectively.The percentages of eyes with pachychoroid in 20-39 years group, 40-59 years group and ≥60 years group were 14.71%(10/68), 24.48%(47/192) and 28.89%(55/184), respectively, showing statistically significant differences among them ( χ2=6.170, P=0.046; LR=6.579, P=0.037). The proportion of pachychoroid in ≥60 years group was significantly higher than that of 20-39 years group, showing a statistically significant difference ( χ2=5.982, P=0.014; LR=6.479, P=0.011). Conclusions:The distribution characteristics of pachychoroid vary in normal subjects over age.Age and diopter are the independent influencing factors of SFCT.

Objective:To analyze the clinical and prognosis of children with kidney retransplantation.Methods:Clinical data of 11 children who underwent kidney retransplantation from January 2011 to December 2020 in Department of Nephrology, Children′s Hospital of Fudan University were retrospectilely analyzed. The clinical data including demographic parameters, primary diagnosis, characteristics in the follow-up of renal allograft were analyzed.Results:Totally 11 cases received secondary renal transplantation (male 6, female 5). They were initially diagnosed with chronic kidney disease at the age of 11.9 (7.4, 13.3) years. The median duration of dialysis was 22.1 (3.5, 36.5) months. In the first transplantation, recipient age was 13.9 (11.1, 15.2) years. Ten cases received donation from cardiac death donor (DCD) (9 cases received donors aged less than one year, 5 of them received whole kidney transplantation and one case received donor aged one to three years) and 1 case with living-related donor. Ten graft failures occurred within 1 month after renal transplantation and the other one occurred at the fifth month after transplantation. The causes included vascular factors (9 cases), rejection (1 case) and primary non-function (1 case). In the second transplantation, recipient age was 14.7 (11.7, 16.2) years. All the 11 children received dialysis (7 with PD and 4 with HD) and successfully completed the second transplantation. The median time between the two transplants was 210 (16, 1 041) days. Donors were all DCD donors from 3 years of age or older. The mean follow-up duration was (42±15) months. The estimated glomerular filtration rate was (85±34)ml/(min·1.73 m 2) when the last investigation after kidney retransplantation with the kidney and patient all survived. Conclusions:Kidney retransplantation may have better prognosis in children. Dialysis transition during waiting period and DCD donor from 3 years of age or older can effectively ensure the success of kidney retransplantation.

Objective: In view of the difficulty of the shortage of new coronavirus nucleal acid test in the early COVID-19 outbreak, to explore the application value of chest CT in screening COVID-19 patients. Methods: Retrospective analysis was performed on the data of patients with fever who received chest CT and new coronavirus nucleal acid test during January 25, 2020 to February 2, 2020 in Zhongnan Hospital of Wuhan University. A total of 587 patients were enrolled, including 290 males and 297 females, aged from 11.0 to 96.0 (51.3±17.1) years old. Take the nucleic acid test results as the gold standard, the sensitivity, specificity and rate of missed diagnosis of CT screening COVID-19 were calculated. Results: Among the 587 patients, there were 433 positive cases (73.8%, 433/587) and 154 negative cases (26.2%, 154/587) of novel coronavirus nucleic acid test. Using CT screening, 494 cases (84.2%, 494/587) were positive and 93 cases (15.8%, 93/587) were negative. The sensitivity of CT screening COVID-19 was 97.7% (423/433), specificity was 53.9% (83/154) and rate of missed diagnosis was 2.3% (10/433). Conclusions In the early COVID-19 outbreak, CT screening has the advantages of high sensitivity and low rate of missed diagnosis of COVID-19, which can compensate for the shortage of new coronavirus nucleal acid test and can be used as the basis for rapid screening for early prevention and control of COVID-19 outbreak.

Objective To compare the clinical effects between laparoscopic radical resection combined with radiofrequency ablation (RFA) and open radical resection for colorectal liver metastases.Methods The retrospective cohort study was conducted.The clinicopathological data of 120 colorectal liver metastases patients who were admitted to the Mengchao Hepatobiliary Hospital of Fujian Medical University (80 patients) and the Third Mfiliated Hospital of Chongqing Medical University (40 patients) between September 2012 and April 2017 were collected.Sixty patients undergoing laparoscopic radical resection of colorectal cancer combined with RFA of liver metastases were allocated into the laparoscopy with RFA group,and 60 undergoing open radical resection of colorectal liver metastases were allocated into the open group.Observation indicators:(1) surgical and postoperative situations;(2) follow-up and survival situations.Follow-up using outpatient examination and telephone interview was performed to detect postoperative survival up to May 2017.Measurement data with normal distribution were represented as x±s,and comparisons between groups were analyzed using independent-sample t test.Measurement data with skewed distribution were described as M (range).Comparisons of count data were analyzed using chi-square test or Fisher exact probability.The repeated measures data were analyzed using the repeated measures ANOVA.The survival curve and rate were respectively drawn and calculated by the Kaplan-Meier method,and the Log-rank test was used for survival analysis.Results (1) Surgical and postoperative situations:① All the patients underwent successful surgery,without conversion to open surgery in the laparoscopy with RFA group.Operation time,volume of intraoperative blood loss,cases with overall complications,death,abdominal pain,nausea and vomiting,liver dysfunction,pleural effusion,non-calculus cholecystitis and peptic ulcer and duration of postoperative hospital stay were respectively (135±34)minutes,(451±197)mL,31,0,18,6,6,4,3,2,(13±4)days in the laparoscopy with RFA group and (165±49)minutes,(794±204)mL,42,1,15,9,10,11,5,5,(19±4)days in the open group,with statistically significant differences in operation time,volume of intraoperative blood loss,cases with overall complications and duration of postoperative hospital stay between groups (t =3.983,9.394,x2 =4.232,t =9.148,P＜0.05),and no statistically significant differences in cases with death,abdominal pain,nausea and vomiting,liver dysfunction,pleural effusion,non-calculus cholecystitis and peptic ulcer between groups x2 =0.376,0.686,1.154,3.733,0.134,0.607,P＞0.05).() Levels of alanine aminotransferase (ALT),total bilirubin (TBil) and prothronbin time (PT) before operation,at day 1 and 3 postoperatively were respectively (70±9)U/L,(399±36)U/L,(231±19) U/L,(21±3) μmol/L,(26±3) μmol/L,(23±5) μmol/L,(17.3±2.4) seconds,(20.2-±4.4) seconds,(18.9±2.8) seconds in the laparoscopy with RFA group and (68± 8) U/L,(412±39)U/L,(253±22)U/L,(21±4)μmol/L,(28±4)μmol/L,(27±8)μmol/L,(16.6±3.0)seconds,(22.1±5.2) seconds,(20.1± 4.4)seconds in the open group,with statistically significant differences in the levels of ALT,TBil and PT before operation,at day 1 and 3 postoperatively between groups (F=16.727,13.115,4.194,P＜0.05).(2) Follow-up and survival situations:120 patients were followed up for 7-24 months,with a median time of 20 months.The postoperative 1-and 2-year tumor-free survival rates,1-and 2-year overall survival rates were respectively 23.3％,11.9％,85.0％,40.0％ in the laparoscopy with RFA group and 20.0％,12.8％,83.3％,38.3％ in the open group,with no statistically significant difference in above indicators between groups (x2 =0.145,0.069,0.012,0.196,P＞0.05).Further analysis showed that postoperative 2-year overall survival rate of patients with 1,2,3 and ＞3 liver metastasis lesions were respectively 53.3％,38.2％,40.0％,16.7％ in the laparoscopy with RFA group and 50.0％,35.7％,40.0％,15.4％ in the open group,with a statistically significant difference in 2-year survival rate of patients with different liver metastasis lesions in the laparoscopy with RFA group (x2 =20.949,P＜0.05) and in the open group (x2 ＝ 21.349,P＜0.05).Conclusion There are some advantages of fewer traumas,less complications,faster postoperative recovery and minimally invasive in laparoscopic radical resection combined with RFA for colorectal liver metastases,meanwhile,less liver metastasis lesions and better prognosis are found.

Objective To explore the effect of heme oxygenase-1 (HO-1) on expressions of hypoxia inducing factor 1 alpha (HIF-1α) and vascular endothelial growth factor (VEGF)and regeneration of hepatic vascular plexus after orthotopic liver transplantation ischemia-reperfusion injury in rats.Methods Theexperimental study was conducted.According to the random number table,240 SD rats were divided into the 3 groups,80 rats in each group.Empty virus group:rats were transfected with the empty virus.Induced group:rats were transfected with HO-1 overexpression adenovirus.Inhibited group:rats were transfected with HO-1 RNAi adenovirus.Rats were made pairs (1 ∶ 1) and established rat liver transplantation model according to two cuffs method.Rats with less weight and with heavier weight were respectively chosen as donor rats and recipient rats,and then recieved tail intravenous injection of adenovirus at 24 hours before operation.(1) Detection of transfection efficiency of adenovirus before operation:HO-1 expression of liver tissue of rats in each group was detected by Western blot at 12 and 24 hours after injection of adenovirus.(2) Liver function test of recipient rats after liver transplantation:liver functions of recipient rats [alanine transaminase (ALT),aspartate transaminase (AST),alkaline phosphatase (ALP),gamma-glutamyl transferase (GGT)] were detected at l,3,7 and 14 days postoperatively.(3) Pathological histology of liver tissue and injury scores of recipient rats in the 3 groups after liver transplantation:paraffin sections of recipient rats in the 3 groups at postoperative 1 and 14 days were stained by HE staining and observed by light microscope,and were evaluated by Suzuki damage score standard.(4) Relative expressions of HIF-1α,VEGF and HO-1 in liver tissue of recipient rats were detected by Western blot.(5) Von Willebrand factor (vWF) in liver tissue of recipient rats at 14 days postoperatively was detected by immunofluorescence staining and small vessels were counted.Measurement data with normal distribution were represented as x ±s.Comparison between groups was analyzed by the independent-sample t test,comparison among groups was done using one-way ANOVA,and pairwise comparison was analyzed by the LSD test.Results (1) Detection of transfection efficiency of adenovirus before operation:the relative expression of HO-1 of liver tissue of rats at 12 and 24 hours preoperatively after injection of adenovirus was 1.08±0.16 and 1.08±0.26 in the empty virus group,1.18±0.21 and 1.39±0.19 in the induced group,0.87±0.26 and 0.57±0.12 in the inhibited group,respectively,with statistically significant differences in different time points (F =4.232,36.513,P＜ 0.05).(2) Liver function test of recipient rats after liver transplantation:level of ALT at 3 days postoperatively in the empty virus group,induced group and inhibited group was (504±67)U/L,(438±47)U/L and (490±39)U/L,with a statistically significant difference (F=3.517,P＜0.05).Levels of ALT,AST and ALP at 7 days posto-peratively were (443±49) U/L,(430± 34) U/L,(455± 38) U/L in the empty virus group and (382± 49) U/L,(372±50) U/L,(394±25) U/L in the induced group and (493±44) U/L,(455±62) U/L,(470±72) U/L in the inhibited group,respectively,with statistically significant differences (F =10.950,5.667,5.398,P＜0.05).Levels of ALT,AST,ALP and GGT at 14 days postoperatively were (394±46)U/L,(361 ±68)U/L,(417 ±17)U/L,(4.5±1.1)U/L in the empty virus group and (283±47) U/L,(288±60) U/L,(332±46) U/L,(2.5±0.5) U/L in the induced group and (446± 43) U/L,(422± 51) U/L,(423± 63) U/L,(4.3 ± 1.3) U/L in the inhibited group,respectively,with statistically significant differences (F=26.906,9.924,8.013,9.279,P＜ 0.05).(3) Pathological histology of liver tissue and injury scores of recipient rats in the 3 groups after liver transplantation:liver cell swelling,loose cytoplasm and a varying quantity of inflammatory cell infiltration in the portal regions in the liver tissue of 3 groups were observed at 1 day postoperatively.A few inflammatory cell infiltrations in the portal regions,basically normal liver cell arrangement and a slightly swelling of liver cell were found in the empty virus group at 14 days postoperatively.Reduced liver cell swelling and basically normal structure of liver lobule were observed in the induced group.There were small patchy or focal necrosis of liver cell,masses of inflammatory cell infiltration in the portal regions and damage of bile duct in the inhibited group.Suzuki score at 1 day postoperatively in the empty virus group,induced group and inhibited group were respectively 6.7± 1.7,6.1 ± 1.2 and 7.6± 1.3,with no statistically significant difference (F=2.257,P＞0.05).Suzuki score at 14day postoperatively in the empty virus group,induced group and inhibited group were respectively 4.0±0.8,2.9± 0.8 and 5.1± 1.4,with a statistically significant difference (F=9.776,P＜0.05).(4) Western blot results:the relative expressions of HIF-1α and VEGF (43 KD) in liver tissue of recipient rats at 1 day postoperatively were 0.21±0.10,0.30±0.12 in the empty virus group and 0.23±0.09,0.34±0.14 in the induced group and 0.17± 0.06,0.29±0.11 in the inhibited group,respectively,with no statistically significant difference (F =0.902,0.410,P＞0.05).The relative expressions of VEGF (24 KD) and HO-1 in liver tissue of recipient rats at 1 day postoperatively were 1.21 ±0.25,0.55±0.12 in the empty virus group and 2.13±0.40,0.72±0.12 in the induced group and 0.91±0.22,0.26±0.07 in the inhibited group,respectively,with statistically significant differences (F=35.158,39.082,P ＜ 0.05).The relative expressions of HIF-1α,VEGF (43 KD),VEGF (24 KD) and HO-1 in liver tissue of recipient rats at 7 days postoperatively were 0.49±0.22,0.46±0.13,0.98± 0.37,0.98±0.37 in the empty virus group and 0.83±0.26,0.63±0.19,1.60±0.33,1.49±0.46 in the induced group and 0.24±0.09,0.30±0.12,0.64±0.18,0.75±0.26 in the inhibited group,respectively,with statistically significant differences (F=16.853,10.021,20.756,8.156,P＜0.05).(5) Immunofluorescence staining results:number of small vessels at 14 days postoperatively in the empty virus group,induced group and inhibited group was respectively 7.9±2.0,10.6± 1.9 and 7.6 ± 1.9,with a statistically significant difference (F=5.921,P＜0.05).Conclusion HO-1 could promote expressions of HIF-1α and VEGF in liver tissue after liver transplantation ischemia-reperfusion injury and regeneration of intrahepatic vascular plexus,and it also alleviate bile duct ischemia-reperfusion injury after liver transplantation.

Objective To investigate the application of OSCE evaluation system on the medical skills examination of clinical medical students and the significance of this system on the training of their medical skills.Methods 20 teachers examed 150 students by the OSCE evaluation system with 4 test stations,by comparing the score of the students of different test stations by one-way ANOVA and evaluating the system by questionnaire survey with Likert 5 on the degree of satisfaction and Likert 3 on effects and intrinsic influencing factors of the system.Results The score of the first and forth test stations was lower than that in the other stations(P＜0.05).8/5.48％ students and 1/5％ teachers were not satisfied with the system.The OSCE evaluation system could exam the psychological diathesis,ability of communication,cooperation,and clinical thinking,practical skill of the students and its effects are moderate (the score was more than 2.0).Evaluation on the intrinsic influencing factors:Students considered the questions were more difficulty in the 2nd,3rd,1st,4th test stations order.4/20％ teachers considered the questions of the second test station was easy.8/40％ teachers considered the duration of the second test station was too long.More than 70％ students and teachers considered the other indexes were rational.Conclusion The OSCE evaluation system can play an effective role in directing the teaching and learning.It can also help to culture the comprehensive capacity of the students.We should gradually improve the design of the system by considering the intrinsic influencing factors.

Objective To construct a prokaryotic expression plasmid for CPSIT_p7 gene from Chlamydophila psittaci ( Cps) 6BC strain and to evaluate immunogenicity of the recombinant protein His-CPSIT_p7 and detect its dynamic expression at mRNA and protein levels in HeLa cells during persistent Cps infection.Methods The fusion protein His-CPSIT_p7 was expressed in E.coli BL21 and purified by Ni-NTA affinity chromatography .BALB/c mice were immunized with the recombinant protein to prepare polyclonal antibody for evaluation of the immunogenicity of His-CPSIT_p7 by ELISA.Penicillin sodium was used to establish a model of Cps persistence infection .RT-PCR and Western blot assay were performed to de-tect the expression of CPSIT_p7 at mRNA and protein levels during Cps persistent infection .Results The fusion protein His-CPSIT_p7 was successfully expressed with the use of constructed recombinant expression plasmid pET30 a-CPSIT_p7 and purified .ELISA result showed that the specific antibody titer against CPSIT_p7 reached 1 ∶1 000 000 on the 40th days after immunization .The expression of CPSIT_p7 at mRNA and protein levels were increased in a time-dependent manner in Cps-infected HeLa cells .The peak of mRNA level was reached at the time point of 36 hours after infection , followed by a time-dependent decrease during Cps acute infection .However , the expression of CPSIT_p7 at mRNA and protein levels were not decreased until 60 hours after infection during Cps persistent infection .Conclusion His-CPSIT_p7 protein was suc-cessfully expressed in the prokaryotic expression system and purified , showing an advantage of good immuno-genicity.Highly expressed CPSIT_p7 at mRNA and protein levels were detected during Cps persistent infection.