Objective To investigate the clinical features, treatment, and outcome characteristics of patients with Merkel cell carcinoma. Methods The clinical manifestations, laboratory tests, diagnosis and treatment, and follow-up data of six patients with Merkel cell carcinoma were retrospectively analyzed. Results Among the six patients with Merkel cell carcinoma, four were males and two were females, with a median age of 66 years old (57-76 years old). All six patients presented with skin swelling, and the clinical stages were as follows: stageⅠ in three patients, stage Ⅲ in one patient, and stage IV in two patients. Two patients were treated with surgery alone, three patients with surgery combined with radiotherapy and/or chemotherapy, and one patient with immunotherapy combined with chemotherapy. Until the follow-up time, four patients had no disease progression, one patient died because of disease progression, and one patient remained under treatment. Conclusion Limited-stage Merkel cell carcinoma is primarily treated with surgery and radiotherapy, meanwhile, metastatic Merkel cell carcinoma needs systemic therapy, and first-line immune checkpoint inhibitors targeting PD-1/ PD-L1 pathway can achieve better therapeutic results.

The spread of COVID-19 has greatly threatened human health and economic growth. Angiotensin-converting enzyme 2 (ACE2) is a receptor for severe acute respiratory syndrome coronavirus 2 (SARS-COV-2). By attaching to ACE2, SARS-COV-2 reduces its expression and induces lung injury. Vitamin D can inhibit the progression of COVID-19 by inhibiting the activity of ROCK pathway, up-regulating ACE2 expression and bio-availability, and slowing down the adverse reactions caused by Ang II accumulation. This study explored a novel mechanism, i.e., vitamin D protects against COVID-19-induced injury by upregulating ACE2 expression. It provides theoretical guidance for the role of Vitamin D in the prevention and treatment of COVID-19.

Objective To evaluate the clinical efficacy of endoscopic retrograde cholangiopancreatography (ERCP)-based comprehensive minimally invasive treatment for biliary anastomotic stenosis (BAS) after liver transplantation. Methods Clinical data of 60 BAS recipients after liver transplantation were retrospectively analyzed, 54 male and 6 female, aged (48±10) years. ERCP was initially carried out. If it succeeded, plastic or metallic stents were placed into the biliary tract. If it failed, percutaneous transhepatic cholangial drainage (PTCD) or single-operator cholangioscopy (SpyGlass) was adopted to pass through the stenosis. If all these procedures failed, magnetic anastomosis or other special methods were delivered. The incidence and treatment of BAS after liver transplantation were summarized. The efficacy, stent removal and recurrence were observed. Results The median time of incidence of BAS after liver transplantation was 8 (4, 13) months. Within postoperative 1 year, 1-2 years and over 2 years, 39, 16 and 5 recipients were diagnosed with BAS, respectively. All 60 BAS recipients after liver transplantation were successfully treated, including 56 cases initially receiving ERCP, and 41 completing BAS treatment, with a success rate of 73%. The failure of guide wire was the main cause of ERCP failure. The success rates of PTCD, SpyGlass and magnetic anastomosis were 5/9, 5/7 and 7/8, respectively. Two recipients were successfully treated by percutaneous choledochoscope-assisted blunt guide wire technique and stent placement in the biliary and duodenal fistula. After 3 (3, 4) cycles of ERCP and 13 (8, 18) months of stent indwelling, 38 recipients reached the stent removal criteria, including 25 plastic stents and 13 metallic stents. The indwelling time of plastic stents was longer than that of metallic stents (P < 0.05). Six cases suffered from stenosis recurrence at 12 (8, 33) months after stent removal, and the recurrence rate was 16%. Six patients were treated with ERCP, and 5 of them did not recur after the stents were successfully removed. Multivariate analysis showed that delayed diagnosis of stenosis and frequent ERCP before stent removal were the independent risk factors for BAS recurrence (both P < 0.05). Conclusions ERCP-based comprehensive minimally invasive treatment may improve the success rate of BAS treatment after liver transplantation and yield satisfactory long-term efficacy. Delayed diagnosis of BAS and high frequent ERCP required for stent removal are the independent risk factors for BAS recurrence.

Objective:To discuss the type, treatment and results of different therapies of biliary fistula after orthotopic liver tansplantation(OLT).Methods:Data of 24 patients who developed biliary fistula after OLT in the First Affiliated Hospital of Xi′an Jiaotong University from January 2000 to March 2019 were retrospectively analyzed. Patients with biliary fistula were classified into 4 types according to presence or absence of stricture. All patients were treated by endoscopic retrograde cholangiopancreatography (ERCP) or interventional therapy, including endoscopic nasobiliary drainage (ENBD), endoscopic retrograde biliary drainage (ERBD) or percuteneous transhepatic cholangial drainage (PTCD). Main outcome measurements were the onset time of biliary fistula, the site of biliary fistula, the complications of ERCP or PTCD, the time of removing abdominal or biliary drainage tube, and the onset of new biliary stricture.Results:Biliary fistula was found in (46.5±36.6) days (6-122 days) after OLT. The numbers of patients in four types of biliary fistula were 6, 14, 2 and 2, respectively. Biliary fistula was cured in 22 patients, with clinical cure rate of 91.7%. All patients underwent ERCP first, and the technical success rate and clinical cure rate were 87.5% (21/24) and 85.7% (18/21), respectively. The clinical cure rates of ERCP forⅠ-Ⅳ biliary fistula were 6/6, 84.6%(11/13), 1/2, and 0, respectively. The clinical cure rates of ENBD and ERBD were 8/10 and 6/8, respectively. Five cases in whom ERCP failed, underwent PTCD, with technical success and clinical cure rates of 4/5 and 3/4 respectively. Eight patients(33.3%)developed cholangitis after treatment, and the incidence rate seemed higher in type Ⅱ biliary fistula than that in type Ⅰ [35.7% (5/14) VS 16.7% (1/6)]. Incidence of cholangitis was higher in patients with non-anastomotic stricture than those with anastomotic stricture [83.3%(5/6) VS 16.7%(3/18)].Conclusion:The first line treatment for biliary fistula after OLT is ERCP, followed by PTCD. The best procedures of biliary fistula typeⅠ-Ⅳ were ENBD, ENBD combined with ERBD, ENBD and PTCD, respectively.

Objective:To investigate the risk factors for abdominal infection after liver transplantation (LT).Methods:The retrospective case-control study was conducted. The clinical data of 356 patients who underwent LT in the First Affiliated Hospital of Xi′an Jiaotong University from January 2015 to December 2018 were collected. There were 273 males and 83 females, aged from 21 to 67 years, with the median age of 46 years. Observation indications: (1) abdominal infec-tion after LT and distribution of pathogens; (2) analysis of risk factors for abdominal infection after LT; (3) follow-up and survival. Follow-up was performed using outpatient examination and tele-phone interview to detect postoperative 1-year survival rate and cases of death up to June 2020. Measurement data with normal distribution were represented as Mean±SD. Measurement data with skewed distribution were described as M(range). Count data were expressed as absolute numbers or percentages. Univariate analysis was conducted using the chi-square test, t test, Mann-Whitney U test and Fisher exact probability. Multivariate analysis was done using the Logistic regression model. The Kaplan-Meier method was used to calculate sruvival time and survival rates. Log-Rank test was used for survival analysis. Results:(1) Abdominal infection after LT and distribution of pathogens: 63 of 356 recipients had abdominal infection after LT, with the overall incidence of 17.70%(63/356). Of the 63 recipients, 41 cases had abdominal infection within postoperative 2 weeks, 17 cases had multi-drug resistant organism infection. A total of 116 strains of bacteria were isolated from 63 recipients with abdominal infection, 52 of which were gram-negative bacteria, 48 were gram-positive bacteria, 16 were fungi. (2) Analysis of risk factors for abdominal infection after LT: results of univariate analysis showed that preoperative model for end-stage liver disease (MELD) score, preoperative serum albumin, preoperative leukocytes, preoperative prothrombin time, preoperative alanine aminotransferase, preoperative aspartate aminotransferase, operation time, volume of intraoperative blood loss, days of postoperative antibiotic use, postoperative renal failure, postoperative delayed graft function,duration of postoperative intensive care unit stay were related factors for abdominal infection after LT ( Z=-2.456, t=-1.982, Z=-3.193, -2.802, -2.336, -2.276, -2.116, -3.217, χ2=15.807, 10.395, 6.750, Z=-4.468, P<0.05). Liver retransplantaiton and postoperative bile leakage were related factors for abdominal infection after LT ( P<0.05). Results of multivariate analysis showed that preoperative MELD score>20 and liver retransplantation were independent risk factors for abdominal infection after LT ( odds ratio=2.871, 12.875, 95% confidence interval as 1.106-7.448, 1.290-128.521, P<0.05). (3) Follow-up and survival: 356 recipients were followed up for 1-66 months, with a median follow-up time of 32 months. The postoperative 1-year overall survival rate of 63 recipients with abdominal infection and 293 recipients without abdominal infection were 84.60% and 97.03%, respectively, showing a significant difference ( χ2=11.660, P<0.05). During the follow-up, 58 recipients died. Conclusion:Preoperative MELD score>20 and liver retransplantation are independent risk factors for abdominal infection after LT.

Objective:To study the effect of MYD88 L265P mutation on the expression of PD-L1 in tumor cells and tumor microenvironment in diffuse large B-cell lymphoma (DLBCL), and to provide theoretical basis for immunotherapy for patients.Methods:Multiplex ligation-dependent probe amplification (MLPA) was used to detect the frequency of MYD88 L265P mutation in 72 cases of DLBCL diagnosed by pathologists in Cancer Hospital of Chinese Academy of Medical Sciences from August 2008 to May 2010. Expression of PD-L1 in tumor cells and tumor microenvironment in all samples was evaluated using PD-L1 (22C3) and PD-L1 (SP142) with Ventana automatic immunohistochemical (IHC) platform. The relationship between MYD88 L265P mutation and the expression of PD-L1 in DLBCL tumor cells and tumor microenvironment was assessed.Results:Of the 72 cases of DLBCL, MYD88 L265P mutation was detected in 15 (20.8%) cases. Nine cases with JAK2 amplification were excluded, and the remaining 63 cases of DLBCL were divided into MYD88 L265P mutant group ( n=14) and MYD88 L265P wild-type group ( n=49). IHC results showed that among the 14 cases of MYD88 L265P mutant groups, PD-L1 (22C3) was positive in 7 cases (7/14) of tumor cells and PD-L1 (SP142) was positive in 4 cases (4/14) of tumor microenvironment. Among the 49 cases of MYD88 L265P wild-type group, 9 cases (18.4%) were positive for PD-L1 (22C3) in tumor cells, and 38 cases (77.6%) were positive for PD-L1(SP142) in tumor microenvironment. In addition, among the 16 cases with PD-L1(22C3) expression in tumor cells, only 2 of the 7 cases with MYD88 L265P mutation were positive for PD-L1 (SP142) in tumor microenvironment. All 9 cases with wild-type MYD88 L265P were positive for PD-L1 (SP142) in tumor microenvironment. Statistical analysis showed that the expression level of PD-L1 (22C3) in tumor cells in the MYD88 L265P mutant group was significantly higher than that in the MYD88 L265P wild-type group ( P=0.017). The expression level of PD-L1 (SP142) in tumor microenvironment in the MYD88 L265P mutant group was significantly lower than that in the MYD88 L265P wild-type group ( P=0.001). Conclusions:MYD88 L265P mutation may play an important role in the regulation of PD-L1 expression in DLBCL tumor cells and tumor microenvironment. Further studies will provide a theoretical basis for immunotherapy of DLBCL patients with MYD88 L265P mutation.

Objective:To evaluate the association of p53 protein expression with clinicopathological features and prognosis in esophageal spindle cell carcinoma.Methods:A total of 4 439 esophageal squamous cell carcinoma (ESCC) patients who underwent radical esophagectomy without neoadjuvant therapy between May 2010 and May 2019 were included. The HE slides and clinicopathological parameters were reviewed. Among these, there were 63 cases of esophageal spindle cell carcinoma; p53 protein expression was evaluated by immunohistochemistry (IHC) and its correlation with clinicopathological parameters and patients′ outcome was analyzed.Results:The 63 esophageal spindle cell carcinoma accounted for 1.4% (63/4 439) of all ESCC. Of the 63 patients there were 55 males and 8 females, male to female ratio was 7∶1. The p53 protein mutation expression rate was 77.8% (49/63), including 14 cases with wild-type expression, 22 with nonsense mutation expression, and 27 with missense mutation expression. The concordance rate of p53 protein expression between carcinoma components and spindle cell components was 100%. Survival analysis showed that p53 protein mutation expression was significantly correlated with overall survival (OS, P=0.044), patients with p53 protein mutation expression had poorer OS. Conclusion:p53 protein expression is highly concordant in the squamous cell carcinoma components and spindle cell components of esophageal spindle cell carcinoma; its mutation expression is associated with poor outcome of the patients.

Background and purpose:Thyroid carcinoma is a common endocrine tumor with an incidence that has increased over recent decades. The aim of the present study was to investigate the effectiveness of carbon nano-par-ticles-labeled lymph nodes in neck dissection for papillary thyroid cancer (PTC), focusing on the protectiveness for the recurrent laryngeal nerve (RLN) and parathyroid glands.Methods:Forty-eight patients with PTC treated from Apr. to Aug. 2015 were randomly divided into two groups. Group A patients (24 patients) were treated with lobectomy/total thyroidectomy plus unilateral/bilateral central lymph node dissection by conventional meticulous capsular dissection technique; Group B patients (24 patients) were treated with the same surgical procedures as group A, 5 min after the injection of carbon nano-particles. The operative time, intra-operative blood loss, incidence of RLN injury, incidence of transient hypocalcemia, the number of total lymph nodes and the ratio of metastatic nodes were collected and analyzed. Results:For unilateral lobectomy, the number of lymph nodes in group B was signiifcantly greater than that in group A (P<0.05). For total thyroidectomy, the operative time, and the incidence of transient hypocalcemia in group B were both lower than those in group A (P<0.05), and the number of total lymph nodes was signiifcantly higher than that in group A (P<0.05). In group B, the ratio of metastatic nodes were 26.7% (unilateral) and 33.3% (bilateral) in stained lymphnodes, and 11.8% and 25.9% in non-stained lymph nodes.Conclusion:The carbon nano-particles-labeled lymph nodes in neck dissection could facilitate to protect parathyroids and increase the number of lymph nodes, especially in total thyroidectomy plus bilateral central lymph node dissection.

Vigilance is defined as the ability to maintain attention for prolonged periods of time. In order to explore the variation of brain vigilance in work process, we designed addition and subtraction experiment with numbers of three digits to induce the vigilance to change, combined it with psychomotor vigilance task (PVT) to measure this process of electroencephalogram (EEG), extracted and analyzed permutation entropy (PE) of 11 cases of subjects' EEG and made a brief comparison with nonlinear parameter sample entropy (SE). The experimental results showed that: PE could well reflect the dynamic changes of EEG when vigilance decreases, and has advantages of fast arithmetic speed, high noise immunity, and low requirements for EEG length. This can be used as a measure of the brain vigilance indicators.
Attention ; Brain ; physiology ; Electroencephalography ; Entropy ; Humans ; Mathematics