The actin depolymerizing factor/cofilin (ADF/cofilins) are a family of actin-binding proteins expressed in all eukaryotic cells. The ADF/cofilins appear to have multiple functions, and this is reflected in their very complex association with both monomeric and filamentous actin. Phosphorylation by some kinases and other factors such as LIM kinases 1 and 2, TESK 1 and TESK 2 kinase, Insulin, etc, prevents ADF/cofllins from binding actin. The serial researchs of ADF/cofilins are increasingly becoming study hot spots, especially on the relationship between homo-sapiens disease and mechanism of action of ADF/cofilins.Now in this domain wilderness details are still far from clear, such as the mechanism by which actin filaments are depolymerized by ADF/cofilins has been controversial.

Objective To study the expression of signal transducer and activator of transcription 1 (STAT1) in human renal clear cell carcinoma (RCC) and the effect of STATI inhibition on the radiosensi-tivity of RCC. Methods The expression of STAT1 in 34 human RCC samples compared with 12 normal kid-ney tissues was examined by immunohistochemistry method. For in vitro experiments, a human RCC cell line, CRL-1932, was used. Western blotting was performed to evaluate the expression of total and phospory-lated STAT1. Fludarabine and siRNA were respectively used to inhibit the expression of STAT1 in CRL-1932 cells. Clonogenic assay and trypan blue staining assay were used to evaluate the radiosensitivity of CRL-1932 cells. Results The expression of both total and phospborylated STAT1 in human RCC samples was signifi-cantly higher when compared to normal kidney tissues. Similarly, the expression of STAT1 was higher in CRL-1932 cells when compared to fibroblast and Wilm's tumor cell lines. STAT1 expression was inhibited by both fludarabine and siRNA. Radiosensitivity of CRL-1932 cells was enhanced by both fludarabine and siRNA induced STAT1 inhibition. Conclusions STAT1 is over-expressed in both human RCC tissue and cell line. Inhibition of STAT1 can enhance the radiosensitivity of RCC cells.

Objective To impmve the method of "modified comet assay" in predicting the radiosensitivitv of solid tumor. Methods A single cell suspension from biopsy sample was lmdlated on ice with a dose of 5 Gy.The microscope slide was spread with agarose,lysed for 50 minutes,rinsed 3 times rinse solution,and given electrophoresis for 20 minutes. After being stained with PI,cell images were collected through the microscope and analyzed with Lucia G software(Version 4.6).In order to check system/ background errors,every sample was made into control slide and irradiation slide.The end-points were cell DNA contents and tail moment. Results The factors influencing the results included:(1)Sample was iaulty tor the biopsv taken from mucosa and no tumor cells were contained. (2)The slides with a high backgmund ( induced by necrosis) disturbed the measurement of comet assay. (3) Setting lymphocytes as control to check svstem errors was very important. (4)To separately collect images of the normal tissue cells and tumor cells from the biopsy sample improved the conformity between the clinical obscrvation and the lab result. Conclusions To increase the correlation between comet assay and clinical response,it is very helpful to set double control for checking system/background errors and to collect images of the normal tissue cells and tumor cells through the microscope,respectively.

Objective To study the expression of interleukin-1β in aortic dissections and aneurysms. Methods Aortic specimens were obtained from patients with type Ⅰ thoracic aortic dissection (11 cases),ascending thoracic aortic aneurysms (10 cases),and healthy organ donors (7 cases).Expression of interleukin-1β,matrix metalloproteinase-9,and signal transduction factors phospho-p38 and phospho-JNK were detected by real time RT-PCR,Western blot,and immunohistochemistry,respectively.TUNEL staining was performed to detect apoptosis of media cells. Results Apoptosis in the media of thoracic aortic dissection and ascending thoracic aortic aneurysms was dramatically higher than control group.Expression of interleukin-1β gradually increased in an order of control group,thoracic aortic dissection to ascending thoracic aortic aneurysms ( P ＜ 0.01,respectively).Expression of matrix metalloproteinase-9significantly increased in the media of thoracic aortic dissection and ascending thoracic aortic aneurysms compared with control group (P ＜ 0.01,respectively).There were positive correlations between interleukin1 β and matrix metalloproteinase-9,interleukin-1β and phospho-p38 in thoracic aortic dissection ( P ＜ 0.01,respectively),interleukin-1β and apoptosis in ascending thoracic aortic aneurysms (P ＜ 0.01 ).Conclusions Interleukin-1β and interferon-γ might effect the formation of thoracic aortic dissection and ascending thoracic aortic aneurysms possibly through the up-regulation of matrix metalloproteinase-9 and apoptosis of media cells in humans.

Objective:To investigate the cardiac presentations and the possible influencing factors of severe and critical coronavirus disease 2019 (COVID-19).Methods:A retrospective study was conducted. Patients with severe and critical COVID-19 admitted to the Eighth People's Hospital of Guangzhou from January 21st to February 24th 2020 were enrolled. According to the clinical classification, the patients were divided into severe group and critical group. The myocardial injury markers, such as lactate dehydrogenase (LDH), aspartate aminotransferase (AST), creatine kinase (CK), cardiac troponin I (cTnI), myoglobin (MYO), MB isoenzyme of creatine kinase (CK-MB), B-type natriuretic peptide (BNP) and electrocardiogram (ECG) changes were compared between the two groups.Results:A total of 55 COVID-19 patients were selected, including 15 critical cases and 40 severe cases. The patients with severe and critical COVID-19 were male-dominated (61.8%), the average age was (61.2±13.0) years old, 83.6% (46 cases) of them had contact history of Hubei, 38.2% (21 cases) of them were complicated with hypertension. There was no significant difference in baseline data between the critical group and the severe group. Myocardial injury markers of critical and severe COVID-19 patients were increased in different proportion, LDH increased in most patients (20 severe cases and 7 critical cases), followed by AST (16 severe cases and 5 critical cases). There was significant difference in the number of patients with elevated CK between severe group and critical group (cases: 1 vs. 4, P = 0.027). Abnormal ECG was found in 39 of 42 patients with ECG examination. Nonspecific change of T wave was the most common. Before and after treatment, 9 of 15 patients with changes of ECG and myocardial injury markers had oxygenation index less than 100 mmHg (1 mmHg = 0.133 kPa), and the prominent changes of ECG were heart rate increasing and ST-T change. Conclusions:The increase of myocardial injury markers and abnormal ECG were not specific to the myocardial injury of severe and critical COVID-19 patients. At the same time, the dynamic changes of myocardial injury markers and ECG could reflect the situation of myocardial damage.

Objective To compare the clinical choosing principles of sedated colonoscopy with con-ventional colonoscopy. Methods Outpatients who were willing to accept colonoscopy with or without seda-tion were prospectively recruited,which were assigned to sedated colonoscopy group(n=362)and conven-tional colonoscopy group(n=323). All patients and endoscopists were asked to answer a self-administered questionnaire. The colonoscopy completion,operation time,procedure-related discomfort,and questionnaire results of the two groups were compared and statistically analyzed. Results The completion rate was 98. 9%in the sedated colonoscopy group(358/362)and 89. 8% in the conventional colonoscopy group(290/323) ( P=0. 337 ). The operation time of sedated and conventional group were( 5. 60 ± 3. 25 ) minutes and (7. 71 ± 5. 70)minutes respectively(P<0. 001). And the average cost was CNY 886. 54 per patient in se-dated group and CNY 386. 00 per patient in the conventional group. Patient satisfaction score of conventional group and sedated group were 4(3-4)and 3(2-3)points(P<0. 001),while endoscopist satisfaction score was 4(3-4)and 4(4-4)(P<0. 001). A total of 354 patients(97. 79%)in the sedated group and 225 pa-tients(69. 66%)in the conventional group showed willingness to repeat the identical colonoscopy( P <0. 001). Patients who were male(P=0. 035),having no past abdominal operations(P<0. 001),or no ab-dominal pain during colonoscopy( P =0. 015 )in the conventional group preferred to repeat conventional colonoscopy. Conclusion Although the examination time of conventional colonoscopy is longer than sedated colonoscopy,it could reduce anesthesia risk and the cost. Conventional colonoscopy remains an irreplaceable examination of colorectal diseases in developing countries. Physicians should not only focus on patients'com-fort during endoscopy,but also help patients make a decision based on their actual situation and endoscopic indications to make the best of medical resources.

Objective The purpose of this study was to explore common complications and their clinicopathological features in pediatric liver transplantation.Methods Clinical and pathological data of 240 liver biopsies from 168 children that conducted liver puncture from January 2015 to May 2018 in Tianjin First Central Hospital was retrospectively analyzed.We comprehensively analyzed incidence rate and pathological features of various complications,and correlations between acute rejection and C4d staining result or Banff score.Results A total of 86.67％ (208/240) liver biopsies could be definitely diagnosed with incidence rate of main complications in descending order as follows:T cell mediated rejection (TCMR) 60.57％ (126/208),drug-induced liver injury (DILI) 17.31％ (36/208),biliary complication 8.17％ (17/208),vascular complication 3.37％ (7/208),ischemia/reperfusion injury (IRI) 2.88％ (6/208),antibody mediated acute rejection (AMR) 1.92％ (4/208),HBV infection 1.92％ (4/208),non-alcoholic fatty liver disease (NAFLD) 1.44％ (3/208),chronic rejection (CR) 0.96 ％ (2/208) and HCV infection 0.48 ％ (1/208).TCMR and AMR in acute rejection (AR) accounted for 96.92％ (126/130) and 3.08％ (4/160),and into(portal-based,PB)type TCMR accounted for 96.03％(121/126) with the detectable rate of BP type subtype TCMR of 26.45％(32/121)within 30 d.There were 65.87％ (83/126)、25.40％ (32/126) 和4.76％ (6/126) of BP TCMR samples with "Banff ACR RAI" score within 3-5,6-7 and 8-9,and RAI score was negatively correlated with postoperative time (r =0.127,P =0.084).The incidence rate of central perivenulitis (CP) and portal eosinophils infiltration (PEI) in BP TCMR was 63.63％ (77/121) 和43.80％ (53/ 121),respectively,additionally,the PEI level was positively correlate with RAI score (P＜0.05).CP TCMR and AMR occurred within 30d-365 d and 8 d-180 d,respectively postoperative,while,the two CR occurred at 1095 d and 1335 d postoperative,and significant correlation was strikingly observed between rejection subtype and postoperative time (Z =9.231,P =0.026).C4d positive rate was 10％ (24/240),which was associated with Banff score and postoperative time,besides,C4d score was also correlated with rejection subtype and RAI score.The occurrence of DILI was mainly at time of ＜90 d or ＞180 d postoperative,and the detectable rate of biliary complication within 180 d postoperative was 82.35％ (14/17),IRI Appear in ＜30d.Hepatic artery complication account for nearly 57.14％ (4/7),occurrence time is ≤90 d.Occurrence of HBV infection,CMV infection and NAFLD were mainly at ＞365 d,＜90 d and ＜365 d,respectively.Conclusion There were lots of differences in clinical and pathological features among multi pediatric liver transplantation complications.Liver puncture plays an important role in rejection subtype classification and grading,as well as in non-rejection complications identification.

Objective:To explore the relationship between arrhythmogenic right ventricular cardiomyopathy (ARVC) desmosomal protein gene mutations and Yunnan unexplained sudden death (hereinafter referred to as Yunnan sudden death) by detecting 5 common ARVC desmosomal protein gene mutations of Yunnan sudden death cases and their relatives in Heqing County, Yunnan Province.Methods:In January 2021, the autopsy heart cavity blood was collected from Yunnan sudden death cases in 8 villages in Heqing County, and peripheral venous blood samples of relatives of the cases were collected. Blood samples' DNA was extracted, after PCR amplification, 97 exons of 5 desmosomal protein genes [desmoplakin (DSP), desmoglein-2 (DSG2), plakophilin-2 (PKP2), junction plakoglobin (JUP) and desmocollin-2 (DSC2)] were sequenced by Sanger method to analyze gene mutations.Results:Three blood samples of Yunnan sudden death cases and 36 blood samples of relatives were collected. A total of 26 gene mutation sites were detected in 39 blood samples, with a total mutation rate of 26.80% (26/97). There were 13, 5, 3, 3 and 2 mutation sites in DSP, DSG2, PKP2, JUP and DSC2 genes, respectively. Among them, 19 were reported mutations and 7 were new mutations: DSP gene exon 3 c.372G>A, exon 15 c.2090A>G, exon 17 c.2371C>A, exon 24-I c.8458T>G; DSG2 gene exon 8 c.861C>T; PKP2 gene exon 3 c.892C>A, exon 8 c.1725G>T. Three Yunnan sudden death cases and 36 relatives were all carriers of compound gene mutation, and the same person carried 3 - 9 gene mutation sites at the same time.Conclusion:Mutations of ARVC desmosomal protein genes DSP, DSG2, PKP2, JUP and DSC2 exist in Yunnan sudden death cases and their relatives, which may be the genetic background factors of some Yunnan sudden death.

Objective:To analyze common pathogenic gene mutations of arrhythmogenic right ventricular cardiomyopathy (ARVC) in Yunnan unexplained sudden death (hereinafter referred to as Yunnan sudden death) cases, and explore the etiological relationship between Yunnan sudden death and ARVC.Methods:Four typical Yunnan sudden death affected counties (cities) were selected as investigation sites. Cryopreserved autopsy cardiac cavity blood samples were collected from Yunnan sudden death cases ( n = 3), and peripheral venous blood samples were harvested from their relatives (first, second, third and immediate degree of kinship, n = 67) and control population ( n = 49). The DNA of blood samples was extracted for amplification and sequencing of 97 exons of 5 common ARVC desmosomal protein [desmoplakin (DSP), desmocollin-2 (DSC2), desmoglein-2 (DSG2), plakophilin-2 (PKP2) and junction plakoglobin (JUP)] genes, and genetic lineage of Yunnan sudden death cases was investigated. Results:A total of 17 gene mutation sites were discovered in Yunnan sudden death cases and their relatives, with 6, 5, 4, 1 and 1 in the DSP, DSC2, DSG2, PKP2 and JUP genes, which were not found in the control population. Among them, 9 were newly discovered mutation sites and 8 were reported mutation sites. The DSP gene exon 24 c.8472 G>C, a pure contractual sense mutation, was common in the relatives of 4 cases in the same family surveyed; and one immediate relative carried a deletion mutation at c.2368 - 2370 of exon 15 of DSC2 gene.Conclusion:Yunnan sudden death cases and their relatives carry mutations in the ARVC desmosomal protein DSP, DSC2, DSG2, PKP2, and JUP genes, and the onset of some Yunnan sudden death may be associated with mutations in the ARVC desmosomal protein genes.