[Measurement of corneal nerve fiber parameters in patients with Parkinson's disease]

Objective: To analyze the characteristic changes of corneal nerve fibers in patients with Parkinson's disease (PD) by corneal confocal microscopy (CCM) and investigate the association of corneal nerve fiber parameters with disease severity and motor symptoms. Methods: Forty-two patients with PD were recruited from the Department of Neurology, Henan University People's Hospital from June 2018 to October 2019. Meanwhile, 40 healthy controls who visited the hospital for physical examination at the same period were enrolled. Corneal nerve fibers in both eyes of all participants were detected by using CCM. The differences of corneal nerve fibers were comparatively analyzed between PD group and healthy controls. Associations of corneal nerve parameters with clinical characteristics such as course of disease, Hoehn and Yahr stage (H-Y stage), unified Parkinson disease rating scale (UPDRS), levodopa equivalent daily dosage (LEDD) were analyzed by using partial correlations. The receiver operating characteristic (ROC) curve was used to analyze the capability of corneal nerve fibers for distinguishing patients with PD from healthy controls. Results: Corneal nerve fiber density (CNFD) in PD group ((19±3)/mm²) was significantly decreased compared with healthy controls ((28±4)/mm²) (t=10.798, P<0.001). However, corneal nerve branch density (CNBD) was significantly increased in PD group ((25±11)/mm²) compared with healthy controls ((18±6)/mm²) (t=-3.427, P=0.001). Meanwhile, corneal nerve fiber length (CNFL) was decreased in PD group ((11.0±2.5) mm/mm²) in comparison with healthy controls ((12.5±1.6) mm/mm²) (t=3.139, P=0.002). ROC curve analysis revealed that CNFD could discriminate PD patients from healthy controls, with an area under the curve of 0.961 3 (95%CI: 92.42-99.84, P<0.000 1). CNFD was negatively correlated with H-Y stage and UPDRS-Ⅲ (r=-0.501 and -0.399, both P<0.05). CNBD was significantly negatively associated with H-Y stage, UPDRS-Ⅲ and UPDRS-Total (r=-0.622, -0.394 and -0.354, respectively, all P<0.05). CNFL was negatively correlated with H-Y stage, UPDRS-Ⅲ and UPDRS-total (r=-0.574, -0.484 and -0.422, respectively, all P<0.05). Conclusion: Small nerve fiber injuries exist in PD patients. Corneal nerve fibers negatively correlates with motor symptoms. CNFD have a good discriminative power to distinguish PD patients from healthy controls and may serve as a marker for PD.

[Association of hyperuricemia-induced renal damage with sirtuin 1 and endothelial nitric oxide synthase in rats]

Objective: To investigate the association of hyperuricemia-induced renal damage with sirtuin 1 (SIRT1) and endothelial nitric oxide synthase (eNOS) in rats. Methods: Using the random number table method, 32 Sprague-Dawley rats were randomly divided into 4 groups: control group, model A group (the model was generated using oxonic acid potassium salt alone), model B group (hyperuricemia model was generated using oxonic acid potassium salt combined with uric acid) and resveratrol group, with 8 rats in each group. The experiment lasted 12 weeks. Serum uric acid and cystatin C levels were monitored regularly. In week 12, serum creatinine and urea nitrogen levels were measured, and the kidneys were extracted. The expression of SIRT1 and eNOS in renal tissues was measured and determined by immunohistochemistry, quantitative reverse-transcription polymerase chain reaction (RT-qPCR) and western blotting. Immunohistochemistry of alpha-smooth muscle actin combined with Masson staining was employed to evaluate the degree of renal fibrosis, and pathological changes were observed based on hematoxylin and eosin staining. Results: In week 12, the uric acid levels in both the model A and model B groups were higher than those in the control group [(316±43) μmol/L, (297±40) μmol/L vs (118±44) μmol/L, both P<0.05]. The levels of cystatin C in the model A, model B, and resveratrol groups were all higher than those in the control group [(156±20) ng/ml, (143±29) ng/ml, (128±26) ng/ml vs (62±18) ng/ml, all P<0.05]. Creatinine levels were higher in the model A and model B groups than those in the control group [(68.5±10.3) μmol/L, (64.5±13.9) μmol/L vs (43.2±10.6) μmol/L, both P<0.05]. The levels of uric acid, cystatin C and creatinine in the resveratrol group were lower than those in the model A group (all P<0.05). Immunohistochemistry, RT-qPCR, and Western blotting for renal SIRT1 and eNOS showed that the expression in the model A and model B groups was inhibited, while the expression in the resveratrol group was not significantly inhibited, compared with that in the control group. Microscopically, obvious abnormalities were not found in the renal tissue of the control group. Renal inflammatory cell aggregation and edema occurred, and interstitial fibrosis was obvious in both the model A and model B groups, while these lesions in the resveratrol group were significantly improved. Conclusions: Hyperuricemia may cause renal injury by inhibiting the expression of SIRT1 and eNOS.

[Preliminary analysis on COVID-19 case spectrum and spread intensity in different provinces in China except Hubei province]

Objective: To analyze the characteristics of COVID-19 case spectrum and spread intensity in different provinces in China except Hubei province. Methods: The daily incidence data and case information of COVID-19 were collected from the official websites of provincial and municipal health commissions. The morbidity rate, severity rate, case-fatality rate, and spread ratio of COVID-19 were calculated. Results: As of 20 March, 2020, a total of 12 941 cases of COVID-19 had been conformed, including 116 deaths, and the average morbidity rate, severity rate and case-fatality rate were 0.97/100 000, 13.5% and 0.90%, respectively. The morbidity rates in Zhejiang (2.12/100 000), Jiangxi (2.01/100 000) and Beijing (1.93/100 000) ranked top three. The characteristics of COVID-19 case spectrum varied from province to province. The first three provinces (autonomous region, municipality) with high severity rates were Tianjin (45.6%), Xinjiang (35.5%) and Heilongjiang (29.5%). The case-fatality rate was highest in Xinjiang (3.95%), followed by Hainan (3.57%) and Heilongjiang (2.70%). The average spread ratio was 0.98 and the spread intensity varied from province to province. Tibet had the lowest spread ratio (0), followed by Qinghai (0.20) and Guangdong (0.23). Conclusion: The intervention measures were effective in preventing the spread of COVID-19 and improved treatment effect in China. However, there were significant differences among different regions in severity, case-fatality rate and spread ratio.

Melatonin promotes adventitious root formation in apple by promoting the function of MdWOX11

BACKGROUND

Melatonin (MT) is important for plant growth and development; however, it is not known whether MT is involved in apple adventitious root (AR) development. In this study, we treated Malus prunifolia (MP) at four different stages of AR development, and analyzed the level of the endogenous hormones MT, auxin (IAA), zeatin-riboside (ZR), abscisic acid (ABA), and gibberellins (GA_1 + 3) in all four treatment groups and the untreated control group. The expression of MT, IAA biosynthesis, transport and signal transduction, the cell cycle, and root development related genes were quantified by RT-qPCR. The function of MdWOX11 was analyzed in transgenic apple plants.

RESULTS

The promotion of AR development by MT was dependent on the stage of AR induction between 0 and 2 d in apple rootstocks. MT-treatment increased the level of IAA and crosstalk existed between MT and IAA during AR formation. The expression of MdWOX11 was induced by MT treatment and positively regulated AR formation in apple. Furthermore, transgenic lines that overexpressed MdWOX11 lines produced more ARs than 'GL3'. Phenotypic analysis indicated that MdWOX11 overexpression lines were more sensitive to exogenous MT treatment than 'GL3', suggesting that MdWOX11 regulates AR formation in response to MT in apple rootstock.

CONCLUSIONS

MT promotes AR formation mainly during the AR induction stage by inducing IAA levels and upregulating MdWOX11.

Melatonin promotes adventitious root formation in apple by promoting the function of MdWOX11

BACKGROUND

Melatonin (MT) is important for plant growth and development; however, it is not known whether MT is involved in apple adventitious root (AR) development. In this study, we treated Malus prunifolia (MP) at four different stages of AR development, and analyzed the level of the endogenous hormones MT, auxin (IAA), zeatin-riboside (ZR), abscisic acid (ABA), and gibberellins (GA_1 + 3) in all four treatment groups and the untreated control group. The expression of MT, IAA biosynthesis, transport and signal transduction, the cell cycle, and root development related genes were quantified by RT-qPCR. The function of MdWOX11 was analyzed in transgenic apple plants.

RESULTS

The promotion of AR development by MT was dependent on the stage of AR induction between 0 and 2 d in apple rootstocks. MT-treatment increased the level of IAA and crosstalk existed between MT and IAA during AR formation. The expression of MdWOX11 was induced by MT treatment and positively regulated AR formation in apple. Furthermore, transgenic lines that overexpressed MdWOX11 lines produced more ARs than 'GL3'. Phenotypic analysis indicated that MdWOX11 overexpression lines were more sensitive to exogenous MT treatment than 'GL3', suggesting that MdWOX11 regulates AR formation in response to MT in apple rootstock.

CONCLUSIONS

MT promotes AR formation mainly during the AR induction stage by inducing IAA levels and upregulating MdWOX11.

[Research progress of ferroptosis-related mechanism and diseases]

Ferroptosis is a new programmed cell death characterized by iron dependent and intracellular oxidative accumulation. Current studies have confirmed that ferroptosis is involved in the occurrence and development of neurotoxicity injury, tumors, cardiovascular diseases and other diseases. This paper reviews the mechanisms of ferroptosis and its role in related diseases based on recent studies.

[Hemodynamic response in cirrhotic patients with transjugular intrahepatic portosystemic shunt]

Objective: To discuss the effects of transjugular intrahepatic portosystemic shunt (TIPS) procedure on hemodynamics in cirrhotic patients. Methods: A total of 23 cirrhotic patients for TIPS insertion were enrolled from January 2018 to October 2018. Serum N-terminal pro-B-type natriuretic peptide (NT-proBNP), transthoracic echocardiography and non-invasive cardiac output measurement based on impedance cardiogram were carried out before and 24h, 1 month, 6 months after TIPS in order to observe cardiac function and hemodynamic changes after TIPS. Results: Significant increases in right atrial area [(17.2±4.0) cm(2) vs. (15.0±3.4) cm(2), P<0.05], right ventricular area [(15.1±3.8) cm(2) vs. (13.7±3.5) cm(2), P<0.05] and left ventricular volume [(97.4±21.5) ml vs. (91.1±22.7) ml, P<0.05] were observed 24 h after TIPS. These changes were accompanied with significant reduction in collapsible index of inferior vena cava [(20.7± 8.1)% vs. (28.6±11.3)%, P<0.01] and elevation in pulmonary arterial systolic pressure [(36.0±8.4) mmHg (1 mmHg=0.133 kPa) vs. (31.8±5.4) mmHg, P<0.01]. There also existed significantly elevated serum NT-proBNP [(551.2±325.1) ng/L vs. (124.2±94.4) ng/L, P<0.01], cardiac output [(5.82±0.96) L/min vs. (5.12±1.28) L/min, P<0.01], cardiac index [(3.47±0.64) L·min(-1)·m(-2) vs. (3.05±0.78) L·min(-1)·m(-2), P<0.01], early diastolic filling rate [(59.0±14.3)% vs. (54.5±11.0)%, P<0.05], and reduced systemic vascular resistance index (SVRi) [(1 798.4±357.3) dyne·s·cm(-5)·m(-2) vs. (2 195.7±508.7) dyne·s·cm(-5)·m(-2), P<0.01] 24 h after TIPS. At the end of 6-month follow-up, all these parameters, but not SVRi, returned towards baseline values. Moreover, peak early to late diastolic tissue velocity ratio at the level of lateral mitral annulus (E'/A') was significantly higher at the end of 6-month follow-up than that at baseline (1.06±0.32 vs. 0.90±0.45, P<0.05). Neither the right ventricular fractional area changes nor the left ventricular ejection fractions during the follow-up period were different from those at baseline (P>0.05). Conclusion: Cirrhotic patients who had no cardiovascular pathologies had adequate adaptation and good compensation ability to reach a new hemodynamic homeostasis for the increased volume load after TIPS insertion.

[Diagnostic accuracy of liver and spleen stiffness by two dimensional shear wave elastography for portal hypertension in hepatitis B-related cirrhosis]

Objective: To assess the diagnostic accuracy of liver and spleen stiffness measured by two dimensional shear wave elastography (2D-SWE) in hepatitis B-related cirrhosis. Methods: The clinical data of fifty-eight hepatitis B-related cirrhosis patients were collected in Zhongshan Hospital, Fudan University from September 2017 to April 2018. Pearson's correlation analyses were used to assess the relationship between liver/spleen stiffness (L-SWE and S-SWE) and hepatic venous pressure gradient (HVPG), as well as the comparison with serological model. The SWE diagnostic performances of Liver (L-SWE), Spleen (S-SWE) were also evaluated. Results: Of all 58 patients, 47 were found HVPG ≥10 mmHg, diagnosed as clinically significant portal hypertension (CSPH) and severe portal hypertension (SPH), which patients are at increased risk of developing complications. Thirty-four patients were found HVPG≥12 mmHg, diagnosed as SPH, which patients were at increased risk of variceal bleeding. Moderate positive correlation was found between L-SWE and HVPG (r=0.42, P<0.01), and S-SWE were significantly correlated with HVPG (r=0.68, P<0.01), while serological models and HVPG were slightly correlated (r=0.36 and 0.28, all P<0.01). The area under the receiver operating characteristic curves of L-SWE, S-SWE and the combination for CSPH were 0.78, 0.88 and 0.89. When L-SWE was>12.86 kPa or S-SWE was>35.73 kPa, patients were at increased risk of developing complications. The area under the receiver operating characteristic curves for SPH were 0.68, 0.81 and 0.77 and the S-SWE had the highest specificity, so when S-SWE was>41.5 kPa, patients were at increased risk of variceal bleeding. Conclusion: L-SWE and S-SWE are reliable and promising non-invasive parameters to assess CSPH and SPH.

Supercomputer-Based Ensemble Docking Drug Discovery Pipeline with Application to Covid-19

We present a supercomputer-driven pipeline for in-silico drug discovery using enhanced sampling molecular dynamics (MD) and ensemble docking. We also describe preliminary results obtained for 23 systems involving eight protein targets of the proteome of SARS CoV-2. THe MD performed is temperature replica-exchange enhanced sampling, making use of the massively parallel supercomputing on the SUMMIT supercomputer at Oak Ridge National Laboratory, with which more than 1ms of enhanced sampling MD can be generated per day. We have ensemble docked repurposing databases to ten configurations of each of the 23 SARS CoV-2 systems using AutoDock Vina. We also demonstrate that using Autodock-GPU on SUMMIT, it is possible to perform exhaustive docking of one billion compounds in under 24 hours. Finally, we discuss preliminary results and planned improvements to the pipeline, including the use of quantum mechanical (QM), machine learning, and AI methods to cluster MD trajectories and rescore docking poses.

[Subclinical heart injury in patients receiving hypofractionated radiotherapy after breast conserving surgery: a preliminary analysis of prospective study]

Objective: To evaluate the incidence of early cardiac injury in patients with left-sided breast cancer receiving hypofractionated radiotherapy after breast conserving surgery, and to investigate the correlation between cardiac injury and hypofractionated radiotherapy dose. Methods: We prospectively enrolled 103 breast cancer patients who received whole breast with or without regional nodal irradiation after breast conserving surgery using either deep inspiration breath-hold (DIBH) or free breathing (FB) radiotherapy technique. Cardiac examinations that included N-terminal pro-B-type natriuretic peptide (NT-proBNP), electrocardiogram, and myocardial perfusion imaging were performed routinely before and after radiotherapy. The effects of heart dose, systemic therapy and individual factors (Framingham score) on the incidence of cardiac events were analyzed. Results: The median age was 48 years. The mean dose (Dmean) of the heart, left anterior descending coronary artery (LAD), left ventricular (LV), and right ventricular (RV) were 4.0, 16.9, 6.3, and 4.4 Gy, respectively. With a median follow-up of 13.4 months, no patient had clinical cardiac abnormalities. The incidence rates of subclinical cardiac events at 1- 6- and 12-month were 23.5%, 31.6%, and 41.3%, respectively. The DIBH group had a lower mean dose, maximum dose, and V5-V40 in the heart, LAD, LV, and RV than the FB group (P<0.001). Univariate analysis showed an increased incidence of subclinical cardiac events with heart Dmean >4 Gy, LAD V40 > 20%, LV Dmean >6 Gy, RV Dmean >7 Gy, or cumulative doses of anthracycline or taxane > 300 mg/m(2) (All P<0.05). Anti-HER2 targeted therapy, endocrine therapy and Framingham score were not associated with the incidence of subclinical cardiac events (all P>0.05). Multivariate analysis demonstrated that Dmean of LV and RV were independently associated with the increased incidence of subclinical cardiac events. Conclusions: Early subclinical heart injury are found in patients with left-sided breast cancer after hypofractionated radiotherapy. The increased incidence of subclinical cardiac events after radiotherapy is positively associated with the cardiac radiation doses.

Impact of trauma centre capacity and volume on the mortality risk of incoming new admissions

INTRODUCTION

Trauma centre capacity and surge volume may affect decisions on where to transport a critically injured patient and whether to bypass the closest facility. Our hypothesis was that overcrowding and high patient acuity would contribute to increase the mortality risk for incoming admissions.

METHODS

For a 6-year period, we merged and cross-correlated our institutional trauma registry with a database on Trauma Resuscitation Unit (TRU) patient admissions, movement and discharges, with average capacity of 12 trauma bays. The outcomes of overall hospital and 24 hours mortality for new trauma admissions (NEW) were assessed by multivariate logistic regression.

RESULTS

There were 42 003 (mean=7000/year) admissions having complete data sets, with 36 354 (87%) patients who were primary trauma admissions, age ≥18 and survival ≥15 min. In the logistic regression model for the entire cohort, NEW admission hospital mortality was only associated with NEW admission age and prehospital Glasgow Coma Scale (GCS) and Shock Index (SI) (all p<0.05). When TRU occupancy reached ≥16 patients, the factors associated with increased NEW admission hospital mortality were existing patients (TRU >1 hour) with SI ≥0.9, recent admissions (TRU ≤1 hour) with age ≥65, NEW admission age and prehospital GCS and SI (all p<0.05).

CONCLUSION

The mortality of incoming patients is not impacted by routine trauma centre overcapacity. In conditions of severe overcrowding, the number of admitted patients with shock physiology and a recent surge of elderly/debilitated patients may influence the mortality risk of a new trauma admission.

[The preliminary analysis on the characteristics of the cluster for the COVID-19]

Since December 2019, COVID-19, a new emerging infection disease, has spread in 27 countries and regions. The clusters of many cases were reported with the epidemic progresses. We collected currently available information for 377 COVID-19 clusters (1 719 cases), excluded the hospital clusters and Hubei cases, during the period from January 1 to February 20, 2020. There were 297 family clusters (79%), case median was 4; 39 clusters of dining (10%), case median was 5; 23 clusters of shopping malls or supermarkets (6%), case median was 13; 12 clusters of work units (3%), case median was 6, and 6 clusters of transportation. We selected 325 cases to estimate the incubation period and its range was 1 to 20 days, median was 7 days, and mode was 4 days. The analysis of the epidemic situation in a department store in China indicated that there was a possibility of patients as the source of infection during the incubation period of the epidemic. From February 5 to 21, 2020, 634 persons were infected on the Diamond Princess Liner. All persons are susceptible to the 2019 coronavirus. Age, patients during the incubation period and the worse environment might be the cause of the cases rising. The progress of the two typical outbreaks clearly demonstrated the spread of the early cases in Wuhan. In conclusion, screening and isolating close contacts remained essential other than clinical treatment during the epidemic. Especially for the healthy people in the epidemic area, isolation was the key.

[Effect of cognitive impairment on social function and quality of life in chronic schizophrenia]

Objective: To clarify the effect of cognitive impairment on social function and quality of life of chronic schizophrenia, and provide clinical cognitive strategies for improving the social function and quality of life of patients with schizophrenia. Methods: Atotal of 158 patients with chronic schizophrenia were selected from May 2017 to October 2017 in the Psychiatry Department of the Third Affiliated Hospital of Sun Yat-sen University received psychological assessments, such as, MATRICS Consensus Cognitive Battery(MCCB), the Brief Psychiatric Rating Scale(BPRS), the Personal and Social Performance scale(PSP), and Schizophrenia Quality of Life Scale(SQLS). We further explored the effects of neurocognitive and social cognitive functions on their individual and social performance and quality of life in patients with schizophrenia. Results: (1) The scores of SQLS in the group with impaired social cognitive function were higher than those with good social function(101±46 vs 76±40, P=0.002). (2) The digital sequence and continuous performance test of the socially functional group were higher than the defect group. (3) There was a significant correlation between the years of education(R(2)=0.334, F=25.542), continuous performance (R(2)=0.316, F=35.647), BPRS (R(2)=0.280, F=60.386) and social function (P<0.001). (4) BPRS (R(2)=0.486, F=228.28), and emotional management (MSCEIT) (R(2)=0.510, F=124.789), education (R(2)=0.531, F=90.161), age (R(2)=0.539, F=69.644) significantly affected the SQLS score of patients with schizophrenia(P<0.001). Conclusion: The social function and quality of life of patients with schizophrenia are significantly correlated with their years of education and disease severity. Continuous performance in neurocognition significantly affects the social function of patients with schizophrenia, and emotional management in social cognition significantly affects their quality of life. Socially functional schizophrenia patients have higher digital sequences (working memory) and continuous performance (attention/alertness) scores.

[The progress on diagnosis and treatment of larynx cancer]

SummaryLaryngeal cancer remains one of the most common tumors of head and neck. While significant advancements have been made over the last several decades, diagnosis and treatment of laryngeal cancer presents an unique challenge given its complexity. It is essential to perform a thorough preoperative assessment by the dedicated multidisciplinary team（MDT）, including confirmed diagnosis, accurate staging, surgical selection, rehabilitation and reconstruction, supportive care and postoperative follow-up. Surgery has been the historical mainstay for localized disease and still is an integral part of treatment, while transoral CO2 laser microsurgery is being increasingly popularised in early stage tumors and occasionally in more advanced forms of the disease. Nonsurgical methods like radiation and systemic therapy have emerged as viable options in patients considered unfit for surgery or those who refuse it. In addition, novel targeted agents are showing promise for the population with metastases. Currently, a multimodal approach is preferred in advanced cases, but the optimal strategy remains under debate. Close follow-up is crucial in achieving early detection and being able to treat the recurrence with curative intention. In summary, all patients should have a comprehensive evaluation and treatment plan in a multidisciplinary setting. This highlights the need for further research and innovation in the field.

[Clinical characteristics of Kaposiform lymphangiomatosis: a report of 8 cases]

Objective: To investigate the clinical symptoms, treatment intervention and prognosis of Kaposiform lymphangiomatosis(KLA). Methods: Medical information and clinical characteristics data of 8 KLA patients who were admitted to Department of Pediatric Surgery of West China Hospital of Sichuan University from January 2016 to February 2019 were retrospectively reviewed and analyzed. There were 5 males and 3 females with age of 5.8 years old (from 8 months to 29 years old). Results: The lesions in all patients were diffusely distributed. In all 8 patients, the lung and mediastinum were involved with different degrees. Three cases had lesions involving pelvic and abdominal organs. Three cases had lesions involving bones. One case simultaneously involved pelvic and abdominal organs, and 1 case was involved laryngeal and neck. The clinical characteristics were mainly respiratory symptoms. In the laboratory tests, 6 patients had different degrees of thrombocytopenia (minimum 3 × 10(9)/L), and 4 patients had severe fibrinogen reduction (minimum 0.42 g/L). Three patients had prolonged activated partial thromboplastin time (up to 64.2 seconds) and 3 patients had prolonged prothrombin time (up to 18.6 seconds). After surgery (including thoracotomy, chest tube, pericardiocentesis, splenectomy) and empiric medicine therapy (vincristine, sirolimus and corticosteroid), the symptoms improved in 1 case, 2 cases died of complications, 2 cases were stable and 3 cases progressed up to February 2019. Conclusions: KLA is a rare disease that should be differentiated from other types of vascular diseases. Currently, there is no consensus treatment guidelines exist. Accurate diagnosis in KLA can be a challenge. The situation in patients with KLA is prone to rapid deterioration and progress. Future research efforts should seek to develop target-specific drugs for KLA.

[Prediction model for survival in patients with biliary tract cancer: a development and validation study]

Objective: The aim of the present study was to investigate the survival rate and its prognostic factors for patients with biliary tract cancer, and then a prognostic risk prediction model was constructed to predict the survival probability of patients. Methods: A total of 14 005 patients with biliary tract cancer (including gallbladder cancer, extrahepatic bile duct cancer, and ampulla of Vater cancer), who were diagnosed between 2010 and 2015 in the US National Cancer Institute Surveillance, Epidemiology, and End Results Program (SEER) were included in the development cohort. The prognostic risk factors of biliary tract cancer were investigated using multivariate Cox regression models. The predictive nomograms were then constructed to predict the overall survival probability of 1, 3, and 5 years, and the predictive discrimination and calibration ability of the nomograms were further evaluated. Meanwhile, 11 953 patients who were diagnosed during 2004 to 2009 from SEER Program were then selected to validate the external predictive accuracy of the prediction models. Results: The 1, 3 and 5-year cumulative survival rates of patients with biliary tract cancer were 41.9%, 20.4% and 15.3%, respectively, in the development cohort. Age greater than 50 years, African Americans and Native Americans and Alaska Natives, higher T, N and M stage and poor histological differentiation grade were risk factors for death, while married status, Asia-Pacific Islanders, insured status and surgery on primary site were protective factors. Gender was not significantly associated with the overall survival. The C statistic of the prediction model was 0.73 (95%CI: 0.72-0.74), and the calibration curve showed that the interaction curves of predictive and actual survival rates of 1, 3 and 5 years were close to the 45 degree diagonal. Results in the validation cohort were similar with those in the construction cohort, with a C statistic of 0.70 (95%CI: 0.69-0.72), indicating high external applicability of the prediction model. Findings from gallbladder cancer, extrahepatic bile duct cancer, and ampulla of Vater cancer are in consistent with the overall biliary tract cancer. Conclusions: The survival rate of patients with biliary tract cancer is relatively poor, and the survival prediction model based on prognostic factors has high prediction accuracy. In the future, this prognostic prediction model could be applied to clinical practice to guide individualized treatment for patients with biliary tract cancer.

[Multi-center empirical study of virtual gastroscopy simulator in the examination of clinical practice skills of specialist physicians]

Objective: To study the role of virtual gastroscopy simulator in the examination of clinical practice skills of gastrointestinal specialists. Methods: A multi-center empirical study was carried out. In June 2018, ninety participants from three tertiary care teaching hospitals in China, including Zhongshan Hospital of Fudan University, Shanghai Tongji Hospital and Xiangya Hospital of Central South University, took part in the examination. Participants were selected as follows: 30 specialists without any experience of gastroscopy exams, 30 with basic knowledge (gastroscopy exams <500 cases) and 30 with good skill (gastroscopy exams ≥500 cases). These 90 students participated in this empirical study after theoretical study and simulator training. Among them, 50 (55.6%) were undergraduates, 25 (27.8%) masters, and 15 (16.7%) doctors; 42 (46.7%) were residents, 39 (43.3%) attending physicians, and 9 (10.0%) deputy chief physicians. The assessment was divided into two parts. The first part was to use the simulator (GI mentor II) for ballooning within 10 minutes, with a total score of 40 points. The second part was a complete gastroscopy exam on the simulator, including preparation before gastroscopy exam, gastroscopy exam, post - exam management and related knowledge quiz. The difficulty and discrimination of the assessment plan were evaluated by the extreme grouping method parameters (difficulty P definition: <0.3 was difficult, 0.3 to 0.7 was medium, ≥0.7 was easy; discrimination degree D definition: <0 was poor, 0 to 0.2 was medium, ≥0.2 was good), and by comparing the virtual gastroscopy assessment scores of different experience, academic, and professional title groups. The score analysis of the student group was expressed using the mastering rate (the average score divided by the total score). The data of the normal distribution was represented by (mean±SD) (range), and the data of the nonnormal distribution was represented by M (P25, P75). Kruskal-Wallis non-parametric test was used for comparison between groups. Results: The total score of 90 students was (82.9±10.9) (55.8 to 99.0), and the mastering rate was 82.9%. The overall difficulty of the first and the second parts were 0.78 and 0.76, respectively, and the difficulty level was easy. The overall discrimination of the first and the second parts were 0.70 and 0.67, respectively, and the discrimination was good. The stratified analysis was performed according to the professional title. The median score was 83.2 (75.5, 89.0) in the residents, 82.5 (71.7, 93.6) in the attending physicians, and 93.5 (88.5, 99.0) in the deputy chief physicians, and the difference was statistically significant (H=6.213, P=0.045). According to the stratification analysis of academic qualifications, the median score was 81.7 (73.0, 87.5) in participants with undergraduate degree, 91.0 (79.0, 95.0) in those with master degree and 88.0 (81.7, 93.5) in those with doctor degree, whose difference was statistically significant (H=9.233, P=0.010). The stratified analysis of the second part showed that the median scores of the "operational process" part of the low, medium and high basis group were 33.0 (30.5, 36.5), 34.0 (32.0, 36.0) and 37.0 (35.0, 37.5), respectively, whose difference was statistically significant (H=7.603, P=0.022). The median scores of the "operational process" section of the resident, attending physician, and deputy chief physician were 33.0 (30.5, 35.0) points, 36.0 (34.0, 37.5) points and 37.0 (37.0, 37.5) points, respectively, whose difference was statistically significant (H=18.563, P=0.001). Conclusions: The virtual gastroscopy simulator can reflect the true level of gastroscopy exam skills of the students. The examination questions are moderately difficult, and there is a good discrimination of the exam.

[The 8th edition of the American Joint Committee on Cancer staging system provide improved prognostic accuracy in T1-2N1M0 postmastectomy breast cancer patients]

Objective: To validate whether the prognostic stage groups by the 8th edition of the American Joint Committee on Cancer (AJCC) staging system provides improved prognostic accuracy in T1-2N1M0 postmastectomy breast cancer patients compared to 7th edition. Methods: a total of 1 823 female patients with T1-2N1M0 breast cancer who underwent mastectomy and axillary lymph node dissection without neoadjuvant chemotherapy were analyzed and restaged according to 8th edition. Univariate analysis of prognostic factors was evaluated by using log-rank test. Multivariate analysis was estimated by using the Cox proportional hazards model. The prognostic accuracy of the two staging systems was compared using receiver operating characteristic (ROC) analyses and the concordance index (C-index). Results: 5-year locoregional recurrence rate (LRR) for the whole group was 6.0%, 5-year distant metastasis (DM) rate was 11.5%, 5-year disease-free survival (DFS) was 85.0%, and 5-year overall survival (OS) was 93.1%. Cox analysis showed that 7th edition of the AJCC staging system and progesterone receptor status were independent risk factors for LRR, DM, DFS and OS (P<0.05). Compared with stage by 7th edition, 1 278(70.1%) were assigned to a different prognostic stage group: 1 088 (85.1%) to a lower stage and 190 (14.9%) to a higher stage. LRR, DM, DFS and OS were significantly different between prognostic stage ⅠA, ⅠB, ⅡA, ⅡB and ⅢA according to 8th edition of the AJCC staging system(P<0.001). Prognostic stage had significantly higher C-indexes and provided better estimation of prognosis compared to stage by 7th edition of the AJCC staging system (P<0.001). Conclusion: The prognostic stage groups of 8th edition AJCC staging system has superior prognostic accuracy compared to 7th edition in T1-2N1M0 breast cancer, and has better clinical therapeutic guidance value.

[Hemorrhage-prevention value of second-look endoscopy after endoscopic submucosal dissection for early gastric cancer: a meta-analysis]

Objective: To use the meta-analysis in evaluating the hemorrhage-prevention value of second-look endoscopy after endoscopic submucosal dissection (ESD) for early gastric cancer. Methods: A literature search was conducted to identify all relevant studies comparing second-look endoscopy and non-second-look endoscopy after gastric ESD. The Medline/PubMed, Ovid, Elsevier ScienceDirect, EBSCO, CNKI and VIP databases were searched systematically. Literature inclusion criteria: (1) all the patients were diagnosed as early gastric cancer receiving ESD; (2) end point of the study included postoperative bleeding rate of ESD. Exclusion criteria: (1) papers of repeated research, review, comment, guideline, etc; (2) non-control study. Meta-analysis method was used to calculate a pooled odds ratio (OR) for developing post-ESD bleeding. Results: The meta-analysis showed that post-ESD bleeding was observed in 40 of 1287 patients (3.1%) without second-look endoscopy and in 40 of 968 patients (4.1%) with second- look endoscopy (OR=1.25, 95% CI: 0.79-1.98), with no significant difference between these two groups. Subgroup analysis on research method still indicated no significant difference of post-ESD bleeding between RCT group (OR=1.45,95%CI: 0.79-2.65) and non-RCT group (OR=1.02, 95%CI: 0.50-2.08) (all P>0.05). Conclusion: Based on meta analysis, second-look endoscopy can not reduce the rate of postoperative bleeding of ESD. Therefore, routine second-look endoscopy after gastric ESD may not be necessary to prevent delayed postoperative bleeding of ESD.

[Repair effect of adipose-derived mesenchymal stem cells on lung injury in rats exposed to silica]

Objective: To observe the repairing effect of adipose mesenchymal stem cells (ADSCs) on lung injury induced by silica in rats. Methods: Primary ADSCs-GFP was obtained from rats. ADSCs-GFP was injected into tail vein of silicosis model rats. The expression of green fluorescence in lungs was observed regularly to determine the homing ability of ADSCs. Primary ADSCs of rats were obtained and randomly divided into control group, exposure group, vehicle group and ADSCs group. Silicosis rat model was established by non-exposed tracheal drip method. 24 hours after silica exposure, rats in ADSCs group were injected with ADSCs of 1×10(6)/kg body weight through tail vein, and the pathological changes of lung tissue were observed and evaluated 28 days after intervention. To explore the early intervention mechanism of ADSCs on pulmonary fibrosis in silicosis model rats, apoptosis-related proteins were detected by immunohistochemistry. Results: 28 days after exposure to silica, rats in the exposure group showed obvious pulmonary fibrosis. Compared with exposure group and vehicle group, ADSCs group showed less pulmonary inflammation, less silica nodules and less collagen deposition area. Immunohistochemical results showed that the expression of Caspase-3 and cytochrome C protein decreased and Bcl-2 protein increased after ADSCs transplantation. Conclusion: ADSCs infusion has an obvious intervention effect on postponing early silicosis fibrosis in rats exposed to silica, and its mechanism is related to the regulation of apoptotic process.

[Qualitative pathological assessment of liver fibrosis regression after antiviral therapy in patients with chronic hepatitis B]

Objective: To investigate the methods for qualitative pathological assessment of dynamic changes in liver fibrosis/cirrhosis after antiviral therapy in patients with chronic hepatitis B (CHB), since antiviral therapy can partially reverse liver fibrosis and cirrhosis caused by hepatitis B and semi-quantitative, rather than qualitative, pathological assessment is often used for the research on liver fibrosis regression. Methods: Previously untreated CHB patients with liver fibrosis and cirrhosis were enrolled, and liver biopsy was performed before treatment and at 78 weeks after the antiviral therapy based on entecavir. The follow-up assessment was performed once every half a year. Based on the proportion of different types of fibrous septum, we put forward the new qualitative criteria called P-I-R classification (predominantly progressive, predominantly regressive, and indeterminate) for evaluating dynamic changes in liver fibrosis. This classification or Ishak fibrosis stage was used to evaluate the change in liver fibrosis after treatment and Ishak liver inflammation score was used to evaluate the change in liver inflammation after treatment. Results: A total of 112 CHB patients who underwent liver biopsy before and after treatment were enrolled, and among these patients, 71 with an Ishak stage of ≥3 and qualified results of live biopsy were included in the final analysis. Based on the P-I-R classification, 58% (41/71) were classified as predominantly progressive, 29% (21/71) were classified as indeterminate, and 13% (9/71) were classified as predominantly regressive; there were no significant differences between the three groups in alanine aminotransferase, aspartate aminotransferase, albumin, HBeAg positive rate, HBV DNA, and liver stiffness (P < 0.05). After treatment, the proportion of predominantly progressive, indeterminate, or predominantly regressive patients changed to 11% (8/71), 11% (8/71), and 78% (55/71), respectively. Among the 35 patients who had no change in Ishak stage after treatment, 72% (25/35) were classified as predominantly regressive and had certain reductions in the Laennec score, percentage of collagen area, and liver stiffness. Conclusion: This new P-I-R classification can be used to assess the dynamic changes in liver fibrosis after antiviral therapy in CHB patients.