Objective To evaluate the clinical efficacy of artificial intelligence(AI)-assisted imaging diagnostic trials using multi-reader multi-case(MRMC)design,so as to provide a scientific basis for clinical evaluation of imaging diagnostic trials.Methods The MRMC design,widely used in imaging diagnostic trials,was adopted in this study.The Obuchowski-Rockette(OR)method of MRMC design was detailed,including model construction and test methods.A case study was conducted,collecting imaging data of 200 subjects from 3 hospitals,with 133 cases of rib fractures and 68 cases of non-rib fractures.Three radiologists reviewed all CT images of the subjects.The area under curve(AUC)value,sensitivity and specificity in detecting rib fractures between 2 reading modalities(radiologists with AI assistance vs radiologists reading independently)were compared.Results The AI-assisted reading group had an AUC value of 0.958,while the radiologist-independent reading group had an AUC value of 0.902,showing a significant difference(P＜0.001).The overall sensitivity and specificity of the AI-assisted reading group were 0.970 and 0.946,respectively;while the sensitivity and specificity of the radiologist-independent reading group were 0.838 and 0.966,respectively.The difference of sensitivity between groups was 0.131(95％confidence interval[CI]0.091-0.171),and the difference of specificity was-0.020(95％CI-0.059-0.020),indicating a significant difference in sensitivity but not in specificity between AI-assisted and radiologist-independent reading groups.Both groups had positive likelihood ratios(+LR)greater than 10 and negative likelihood ratios(-LR)less than 0.2,with positive predictive values approaching 1,suggesting that the diagnostic accuracy of the AI-assisted imaging diagnostic trials was high.Conclusion The AI-assisted reading method demonstrates a significant advantage in enhancing diagnostic efficiency,not only improving the diagnostic accuracy and detection rate of rib fractures,but also improving the work efficiency of radiologists and optimizing hospital services.

Objective To estimate the sample size of radiological diagnostic tests in multireader multicase(MRMC)design,and to explore the numbers of readers and cases under 3 different inference situations:random-reader random-case,fixed-reader random-case,and random-reader fixed-case.Methods The images of 114 participants(45 cases diagnosed as aortic coarctation by the gold standard)in the Van Dyke dataset were used,and 5 radiologists read these images under 2 different magnetic resonance imaging(MRI)sequences(Spin-echo and Cine MRI)to obtain the pre-experiment data.Then Obuchowski-Rockette method was used to estimate sample size.Results The mean area under curve(AUC)of aortic coarctation determined by radiologists was 0.941(95%confidence interval[CI]0.899-0.983)with the Spin-echo MRI sequence,and 0.897(95%CI 0.837-0.957)with the Cine MRI sequence.When the effect size was 0.044 and the number of readers was 5,we needed 337 participants for random-reader random-case,162 participants for fixed-reader random-case,and 282 participants for random-reader fixed-case.Conclusion In MRMC design,we need both the number of readers and cases;the larger the number of readers,the smaller the cases required.We need more samples under the situation of random-reader random-case,when the number of readers is≥5.

Objective This study constructed the generalized boosting model combined with propensity score overlap weighting(GBM-OW).Methods Within the situations that there are complex relationships between confounders and treatment factors,and different sample size and different propensity score overlap,we explored the performance of GBM-OW model in balance confounders and estimate effect.And compared with multivariate adjusted model and other three propensity score weighting models.Results and Conclusion From the simulation results we concluded that when the relationship between variables is complex,the sample size is large,and the propensity score value overlap is small,the GBM-OW model has a good performance in all aspects and can be used in observational studies.

Objective:To investigate the clinical characters and prognostic value of PSA flare and bone flare in metastatic castration resistant prostate cancer(mCRPC) patients received Abiterone acetate(AA) therapy.Methods:A retrospective study was conducted for 93 mCRPC patients treated with AA from Jul.2016 to Dec.2020. Mean age was (75.4±8.9)years, median PSA was 58.2 (16.4, 148.6)ng/ml. Patients received at least 6 months of AA treatment. PSA flare was defined as an increase of PSA after AA therapy followed by a decrease. Bone flare was defined as disease progression after 3 months of therapy, typically based on increased lesion intensity or number, and reevaluation 6-9 months later showed improvement in the scan. The clinical characters and prognostic value of the flare phenomenon was evaluated and analyzed respectively.Results:The median follow up time was 16 months(6, 54 months), fourteen patients showed PSA flare at first month after AA treatment, and median time of duration was 2 months(1, 7 months). The serum alkaline phosphatase (ALP) had a similar rising trend along with PSA flare[115.5(98.0, 198.5)U/L vs. 119.0(97.0, 288.8)U/L, P=0.016]. Seven patients showed bone flare and 3 cases co-existed with PSA flare. Multivariate Cox regression analysis indicated bone flare was an independent protective factor for progression free survival(PFS)( HR=0.117, 95% CI 0.015-0.895, P=0.039), PSA flare had no significant influence on PFS ( HR=1.314, 95% CI 0.554-3.121, P=0.536)and overall survival(OS)( HR=1.348, 95% CI 0.393-4.263, P=0.635). Log-rank test showed patients with bone flare had a longer PFS( P=0.016) and OS( P=0.047) compared with patients without bone flare. Conclusions:PSA flare always faded away after 2 months AA therapy and had no influence on PFS and OS. Bone flare maybe an indication for better prognosis.

OBJECTIVE: To investigate the correlation between early-stage blood pressure indexes and prognosis in sepsis patients. METHODS: A retrospective cohort study was conducted on the medical records of patients diagnosed with sepsis from 2001 to 2012 in the Medical Information Mart for Intensive Care-III (MIMIC-III) database. Patients were divided into survival group and death group according to the 28-day prognosis. General data of patients and heart rate (HR) and blood pressure at admission to ICU and within 24 hours after admission were collected. The blood pressure indexes including the maximum, median and mean value of systolic index, diastolic index and mean arterial pressure (MAP) index were calculated. The data were randomly divided into training set and validation set (4 : 1). Univariate Logistic regression analysis was used to screen covariates, and multivariate Logistic stepwise regression models were further developed. Model 1 (including HR, blood pressure, and blood pressure index related variables with P < 0.1 and other variables with P < 0.05) and Model 2 (including HR, blood pressure, and blood pressure index related variables with P < 0.1) were developed respectively. The receiver operator characteristic curve (ROC curve), precision recall curve (PRC) and decision curve analysis (DCA) curve were used to evaluate the quality of the two models, and the influencing factors of the prognosis of sepsis patients were analyzed. Finally, nomogram model was developed according to the better model and effectiveness of it was evaluated. RESULTS: A total of 11 559 sepsis patients were included in the study, with 10 012 patients in the survival group and 1 547 patients in the death group. There were significant differences in age, survival time, Elixhauser comorbidity score and other 46 variables between the two groups (all P < 0.05). Thirty-seven variables were preliminarily screened by univariate Logistic regression analysis. After multivariate Logistic stepwise regression model screening, among the indicators related to HR, blood pressure and blood pressure index, the HR at admission to ICU [odds ratio (OR) = 0.992, 95% confidence interval (95%CI) was 0.988-0.997] and the maximum HR (OR = 1.006, 95%CI was 1.001-1.011), maximum MAP index (OR = 1.620, 95%CI was 1.244-2.126), mean diastolic index (OR = 0.283, 95%CI was 0.091-0.856), median systolic index (OR = 2.149, 95%CI was 0.805-4.461), median diastolic index (OR = 3.986, 95%CI was 1.376-11.758) were selected (all P < 0.1). There were 14 other variables with P < 0.05, including age, Elixhauser comorbidity score, continuous renal replacement therapy (CRRT), use of ventilator, sedation and analgesia, norepinephrine, norepinephrine, highest serum creatinine (SCr), maximum blood urea nitrogen (BUN), highest prothrombin time (PT), highest activated partial thromboplastin time (APTT), lowest platelet count (PLT), highest white blood cell count (WBC), minimum hemoglobin (Hb). The ROC curve showed that the area under the curve (AUC) of Model 1 and Model 2 were 0.769 and 0.637, respectively, indicating that model 1 had higher prediction accuracy. The PRC curve showed that the AUC of Model 1 and Model 2 were 0.381 and 0.240, respectively, indicating that Model 1 had a better effect. The DCA curve showed that when the threshold was 0-0.8 (the probability of death was 0-80%), the net benefit rate of Model 1 was higher than that of Model 2. The calibration curve showed that the prediction effect of the nomogram model developed according to Model 1 was in good agreement with the actual outcome. The Bootstrap verification results showed that the nomogram model was consistent with the above results and had good prediction effects. CONCLUSIONS The nomogram model constructed has good prediction effects on the 28-day prognosis in sepsis patients, and the blood pressure indexes are important predictors in the model.
Humans ; Cohort Studies ; Retrospective Studies ; Blood Pressure ; Intensive Care Units ; ROC Curve ; Sepsis/diagnosis* ; Prognosis ; Critical Care ; Norepinephrine

ObjectiveTo design and evaluate the ideological and political teaching in the Medical Statistics as a public basic course for postgraduates in a medical school. MethodsThrough expert consultation， literature review， investigation， we designed the main points in the ideological and political teaching for the Medical Statistics. Students' satisfaction and demand of ideological and political teaching were investigated by a questionnaire. Furthermore， effect of ideological and political teaching was evaluated. ResultsA total of 178 out of 201 graduate students in Grade 2020 in a medical university completed the survey， accounting for 88.56%， with a response rate of 100%. Among them， 84.27% of the students believed it was necessary to implement ideological and political teaching for the Medical Statistics， and 90.45% expected that ideological and political teaching could be combined with case studies. The comparison before and after class showed that the students’ correct understanding of data acquisition has been greatly improved from 78.65% to 100%. In addition， the proportion of those who were dedicated to studying increased from 89.88% to 97.75%. ConclusionThe ideological and political teaching for Medical Statistics can be implemented in combination with case studies. Ideological and political teaching may improve the courses with practical operation of knowledge and skills.

Objective:To investigate molecules involved in the occurrence of pruritus in patients with mycosis fungoides (MF) .Methods:Totally, 522 patients with MF were enrolled from Peking University First Hospital from October 2009 to August 2021, and the incidence of pruritus was calculated. The patients were grouped according to whether they suffered from pruritus or not. RNA sequencing data on biopsied skin lesions of 49 patients were analyzed to identify differentially expressed genes between patients with pruritus and those without; enzyme-linked immunosorbent assay and immunohistochemical techniques were performed to determine the protein expression of CC chemokine ligand 17 (CCL17) in serum samples from 88 MF patients, and in tissue samples from 81 MF patients, respectively; flow cytometry was conducted to detect markers for T lymphocyte activation and differentiation in peripheral blood samples from 46 MF patients to identify peripheral blood lymphocyte subsets associated with pruritus. Statistical analysis was carried out by using chi-square test, Mann-Whitney U test, and Spearman correlation analysis. Results:Among the 522 patients with MF, 305 were males and 217 were females; 347 were diagnosed with early-stage MF, and 175 with advanced MF. The incidence of pruritus was 67.2% (351/522) in the patients with MF, and significantly higher in the patients with advanced MF (81.7%, 143/175) than in those with early-stage MF (59.9%, 208/347; χ2 = 25.03, P < 0.001) . RNA sequencing showed that CCL17 mRNA expression was significantly higher in the MF patients with pruritus than in those without (fold change = 10.09, P < 0.001) . The serum CCL17 concentration was significantly elevated in the patients with pruritus (1 017.05[377.12, 4 831.80] pg/ml) compared with those without (361.66 [180.47, 500.08] pg/ml; Z = -4.57, P < 0.001) , and correlated with pruritus scores ( r = 0.57, P = 0.010) . In both early and advanced stages of MF, the serum CCL17 concentration was significantly higher in the patients with pruritus than in those without ( Z = -3.68, P < 0.001; Z = -2.54, P = 0.011, respectively) . Immunohistochemical staining revealed that there was no significant difference in the relative quantification value of CCL17 between the patients with pruritus and those without ( Z = -1.84, P = 0.066) . The percentage of CD3 +CD4 +CD26 -CCR4 + malignant T cells significantly increased in the MF patients with pruritus than in those without ( Z = -2.03, P = 0.043) , and was positively correlated with serum CCL17 concentrations ( r = 0.49, P < 0.001) . Conclusions:Both CCL17 mRNA expression in lesional tissues and serum CCL17 concentrations increased in MF patients with pruritus, and CCL17 was associated with the occurrence of pruritus. CCL17 may be involved in the occurrence of pruritus through the recruitment of CD3 +CD4 +CD26 -CCR4 + malignant T cells.

Objective:To investigate the feedback of students towards the application of knowledge-points based preview guidance mode and knowledge-outline based preview guidance mode in medical statistics teaching.Methods:Totally 126 undergraduate students from Batch 2018 five-year clinical medicine were randomly assigned to two groups according to their dormitory number. Before class, knowledge-points focused and knowledge-outline focused preview guidance materials were given to the students in the two groups respectively to assist them in pre-class preview through "Rain Classroom" teaching assistant software. The utilization of preview guidance materials was evaluated and collected. The students' attitudes towards the preview guidance modes they received were collected through questionnaire. In this study, Wilcoxon rank sum test and chi-square test were carried out by SAS9.4 statistical software.Results:The reading completion rate of preview guidance materials in the knowledge-points based preview guidance group was lower than that of the knowledge-outline based preview guidance group (62.78% vs. 80.30%, P<0.001). The median of students' satisfaction score in knowledge-points group and knowledge-outline group were 89.50 and 90.00 respectively, and there was no statistical significance between the two groups ( P=0.252). Of all the students, 61.90%(78/126) of the students strongly liked or liked to receive preview guidance, 75.40%(95/126) of the students thought that preview guidance was very helpful or helpful to classroom learning, 62.70%(79/126) of the students thought that the preview guidance could strongly improve or improve the efficiency of pre-class preview process. The rating results of the above three aspects were similar between the two groups. Conclusion:Both the two preview guidance modes are feasible and effective. The completion rate and evaluation results of the students in the knowledge-points focused preview guidance group are better than those of the knowledge-outline focused preview guidance group. We suggest that knowledge-outline based preview guidance mode might be prioritized in medical statistics teaching.

Objective: To investigate the safety and efficacy of surgical treatment for chronic radiation intestinal injury. Methods: A descriptive cohort study was performed. Clinical data of 73 patients with definite radiation history and diagnosed clinically as chronic radiation intestinal injury, undergoing operation at Department of Colorectal Surgery, the Sixth Affiliated Hospital of Sun Yat-sen University from January 1, 2012 to February 28, 2019, were reviewed and analyzed retrospectively. Patients did not undergo operation or only received adhesiolysis were excluded. All the patients had preoperative examination and overall evaluation of the disease. According to severity of intestinal obstruction and patients′ diet, corresponding nutritional support and conservative treatment were given. Surgical methods: The one-stage bowel resection and anastomosis was the first choice for surgical treatment of chronic radiation intestinal injury. Patients with poor nutritional condition were given enterostomy and postoperative enteral nutrition and second-stage stoma closure and intestinal anastomosis if nutritional condition improved. For those who were unable to perform stoma closure, a permanent stoma should be performed. Patients with severe abdominal adhesion which was difficult to separate, enterostomy or bypass surgery after adhesiolysis would be the surgical choice. For patients with tumor metastasis or recurrence, enterostomy or bypass surgery should be selected. Observation parameters: the overall and major (Clavien-Dindo grades III to V) postoperative complication within 30 days after surgery or during hospitalization; mortality within postoperative 30 days; postoperative hospital stay; time to postoperative recovery of enteral nutrition; time to removal of drainage tube. Results: Of the 73 patients who had been enrolled in this study, 10 were male and 63 were female with median age of 54 (range, 34-80) years. Preoperative evaluation showed that 61 patients had intestinal stenosis, 63 had intestinal obstruction, 11 had intestinal perforation, 20 had intestinal fistula, 3 had intestinal bleeding, and 6 had abdominal abscess, of whom 64(87.7%) patients had multiple complications. Tumor recurrence or metastasis was found in 15 patients. A total of 65(89.0%) patients received preoperative nutritional support, of whom 35 received total parenteral nutrition and 30 received partial parenteral nutrition. The median preoperative nutritional support duration was 8.5 (range, 6.0-16.2) days. The rate of one-stage intestine resection was 69.9% (51/73), and one-stage enterostomy was 23.3% (17/73). In the 51 patients undergoing bowel resection, the average length of resected bowel was (50.3±49.1) cm. Among the 45 patients with intestinal anastomosis, 4 underwent manual anastomosis and 41 underwent stapled anastomosis; 36 underwent side-to-side anastomosis, 5 underwent end-to-side anastomosis, and 4 underwent end-to-end anastomosis. Eighty postoperative complications occurred in 39 patients and the overall postoperative complication rate was 53.4% (39/73), including 39 moderate to severe complications (Clavien-Dindo grade III-V) in 20 patients (27.4%, 20/73) and postoperative anastomotic leakage in 2 patients (2.7%, 2/73). The mortality within postoperative 30 days was 2.7% (2/73); both patients died of abdominal infection, septic shock, and multiple organ failure caused by anastomotic leakage. The median postoperative hospital stay was 13 (11, 23) days, the postoperative enteral nutrition time was (7.2±6.9) days and the postoperative drainage tube removal time was (6.3±4.2) days. Conclusions Surgical treatment, especially one-stage anastomosis, is safe and feasible for chronic radiation intestine injury. Defining the extent of bowel resection, rational selection of the anatomic position of the anastomosis and perioperative nutritional support treatment are the key to reduce postoperative complications.

Objective: To investigate the regulatory effect of miR-1297 on the malignant biological behaviors of breast cancer cells and its underlying mechanism. Methods: Twenty pairs of breast cancer tissues and para-cancer tissues resected at the Department of Thyroid and Breast Surgery of Leshan People′ s Hospital from May 2016 to May 2018, as well as breast cancer cell lines MCF-7, SW626, HCC1937 and human breast epithelial MCF-10A cells were collected for this study. qPCR was performed to evaluate the expression of miR-1297 in breast cancer tissues and cell lines. The experimental cells were divided into control group, miR-1297 inhibitor group; TET3 over-expression group and simultaneous over-expression of TET3 and miR-1297 group. CCK-8 assay was used to detect the cell proliferation of MCF-7 cells; Transwell assay was carried out to detect the migration and invasion of MCF-7 cells; and WB was used to measure the expressions of TET3 and EMT related proteins (E-cadherin, N-cadherin and vimentin). Dual luciferase reporter gene assay was used to verify the relationship between miR-1297 and TET3. Results: miR-1297 was up-regulated in both breast cancer tissues and cell lines (P<0.01 or P<0.05). Knockdown of miR-1297 dramatically repressed the proliferation, migration, invasion and EMT of MCF-7 cells (P<0.01 or P<0.05). Over-expression of TET3 significantly up-regulated the expression of TET3 in MCF-7 cells (P<0.05). Simultaneous over-expression of TET3 and miR-1297 could reverse the expression level of TET3 in MCF-7 cells and the inhibitory effect of TET3 on the proliferation, migration, invasion and EMT of MCF-7 cells. Dual luciferase reporter gene assay results showed that miR-1297 targetedly bound to the 3' UTR of TET3. Further experiment results demonstrated that miR-1297 targetedly down-regulated TET3 and promoted the malignant biological behaviors of MCF-7 cells. Conclusion: miR-1297 is up-regulated in breast cancer tissues and cells; it promotes the malignant biological behaviors such as proliferation, migration, invasion and EMT through targetedly down-regulating the expression of TET3.