ddPCR: a more sensitive and accurate tool for SARS-CoV-2 detection in low viral load specimens

Real time fluorescent quantitative PCR (RT-PCR) is widely used as the gold standard for clinical detection of SARS-CoV-2. However, due to the low viral load in patient throats and the limitations of RT-PCR, significant numbers of false negative reports are inevitable, which results in failure to timely diagnose, early treat, cut off transmission, and assess discharge criteria. To improve this situation, an optimized droplet digital PCR (ddPCR) was used for detection of SARS-CoV-2, which showed that the limit of detection of ddPCR is significantly lower than that of RT-PCR. We further explored the feasibility of ddPCR to detect SARS-CoV-2 nucleic acid from 77 clinical throat swab samples, including 63 suspected outpatients with fever and 14 supposed convalescents who were about to discharge after treatment, and compared with RT-PCR in terms of the diagnostic accuracy. In this double-blind study, we tested, surveyed subsequently and statistically analyzed 77 clinical samples. According to our study, 26 samples from COVID-19 patients with RT-PCR negative were detected as positive by ddPCR. No FPRs of RT-PCR and ddPCR were observed. The sensitivity, specificity, PPV, NPV, NLR and accuracy were improved from 40% (95% CI: 27-55%), 100% (95% CI: 54-100%), 100%, 16% (95% CI: 13-19%), 0.6 (95% CI: 0.48-0.75) and 47% (95% CI: 33-60%) for RT-PCR to 94% (95% CI: 83-99%), 100% (95% CI: 48-100%), 100%, 63% (95% CI: 36-83%), 0.06 (95% CI: 0.02-0.18) and 95% (95% CI: 84-99%) for ddPCR, respectively. Moreover, 14 (42.9 %) convalescents still carry detectable SARS-CoV-2 after discharge. Overall, ddPCR shows superiority for clinical diagnosis of SARS-CoV-2 to reduce the false negative reports, which could be a powerful complement to the current standard RT-PCR. It also suggests that the current clinical practice that the convalescent after discharge continues to be quarantined for at least 2 weeks is completely necessary which can prevent potential viral transmission.

DMBT1 suppresses progression of gallbladder carcinoma through PI3K/AKT signaling pathway by targeting PTEN.

Gallbladder carcinoma (GBC) is a highly lethal malignancy of the gastrointestinal tract. Despite extensive research, the underlying molecular mechanism of GBC remains largely unclear. Deleted in malignant brain tumors 1 (DMBT1) is low-expression during cancer progression and as a potential tumor-suppressor gene in various types of cancer. However, its role in Gallbladder cancer remains poorly understood. Here, we found that DMBT1 was significantly low-expression and deletion of copy number in GBC tissues by qRT-PCR and Western blot. Overexpression of DMBT1 impaired survival, promoted apoptosis in GBC cells in vitro, and inhibited tumor progression in vivo. Further study of underlying mechanisms demonstrated that DMBT1 combined with PTEN which could stabilize PTEN protein, resulting in inhibiting the activation of PI3K/AKT signaling pathway. Our study revealed a new sight of DMBT1 as a tumor-suppressor gene on the PI3K/AKT pathway in GBC, which may be a potential therapeutic target for improving treatment.

Ultrastructural Analysis of Human Gallstones using Synchrotron Radiation µCT.

OBJECTIVE: Gallstone formation is a pathological process of mineralization in the human body. Determination of the morphology and ultrastructure of gallstones holds the key to understanding the pathophysiology of gallbladder disease. Synchrotron radiation phase-contrast Xray microtomography is a novel technology, which is designed for comprehensive analysis of gallstone ultrastructure. MATERIALS AND METHODS: Nine human gallstones were obtained from the Department of Pathology, Qingpu branch of Zhongshan Hospital Affiliated to Fudan University (China), and scanned by synchrotron radiation µCT (SR µCT). The imaging data generated by SR µCT scan were analyzed. RESULTS: The three-dimensional ultrastructure of human gallstones corresponding to their cholesterol and bile pigment composition was determined. CONCLUSIONS: The ultrastructure of gallstones exhibits considerable diversity and complexity. The synchrotron radiation phase-contrast X-ray microtomography is a valuable tool for in-depth study of human gallstones.

Preoperative detection of liver functional reserve in patients with hilar cholangiocarcinoma using the indocyanine green retention test / 中华肝胆外科杂志

Objective To study the use of preoperative indocyanine green retention test at 15 minutes (ICG R15) in the prediction of liver functional reserve in patients with hilar cholangiocarcinoma (HCCA).Methods The clinical data of 62 patients with HCCA treated in our department from March 2016 to March 2018 was reviewed.The relationship between preoperative ICG R15 and postoperative hepatic insufficiency was analyzed.The relationship between preoperative ICG R15 and Child-Pugh scoring was also studied.Univariate analysis was used to evaluate the risk factors of postoperative liver dysfunction.Logistic regression was used to assess the independent risk factors of postoperative liver dysfunction.The regression equation between independent risk factors and postoperative liver dysfunction was established.Results Among the 62 patients,ICG R15 was less than 10.0％ in 26 patients,between 10.0％ and 19.0％ in 17 patients,between 20.0％ and 29.0％ in 9 patients,between 30.0％ and 39.0％ in 5 patients,and over 40.0％ in 5 patients.There were 29 patients with a Child-Pugh A grading and 33 patients with a Child-Pugh B grading in the preoperative evaluation of liver function.The Wilcoxon W rank sum test was used to compare the preoperative ICG R15 in patients with Child-Pugh grading A and B separately.The ICG R15 in Child-Pugh grading A patients was significantly lower than those in Child-Pugh B grading patients (P ＜0.05).There were no significant differences in age,gender,history of previous liver diseases,duration of operation,and intraoperative blood loss (P ＞ 0.05) between the normal liver function group and the liver dysfunction group.However,there was a significant difference in the preoperative ICG R15 and preoperative bilirubin levels (P ＜ 0.05) between the two groups.The preoperative ICG R15 and preoperative bilirubin levels were significant risk factors of postoperative hepatic insufficiency.Regression analysis suggested that preoperative ICG R15 level was an independent risk factor of postoperative hepatic insufficiency (P ＜ 0.05).A regression equation:logit(P) =0.185 × preoperative ICG R15-3.152 could be constructed.Conclusions ICG R15 is an ideal clinical indicator for evaluation of preoperative liver functional reserve in patients with HCCA.It predicted the recovery of postoperative liver function.

Preliminary research on the effect of elemene liposome on gastric cancer cell HGC-27 and its mechanism / 中国癌症杂志

Background and purpose:In recent years, many studies have showed that elemene liposome is widely used in the treatment of digestive tract tumors, malignant pleural effusion and ascites. This study combined in vitro and in vivoexperiments to observe the inhibitory effect of elemene liposome on the growth of human gastric cancer and the HGC-27 cell line.Methods:In order to screen the optimum concentration of elemene liposome, machine vision automatic live cell observation analysis system (Cell-IQ) was applied to detect the best inhibitory effect on human gastric cancer cell line HGC-27, and the lfow cytometry was applied to further detect the apoptosis of HGC-27 treated with elemene liposome. The model of human gastric cancer peritoneal metastasis in nude mice was established to investigate the intervention of elemene liposome and cisplatin (DDP) on peritoneal cancer index (PCI). CD31 marker of tumor microvessel density (MVD) and the expression of vascular endothelial growth factor (VEGF) in tumor tissues were investigated to explore the mechanism underlying the inhibitory effect on peritoneal metastasis of HGC-27 cells in nude mice.Results:Cell-IQ analysis showed that the inhibitory effect of elemene liposome on HGC-27 presented in a positive concentration-dependent manner, which could not be further enhanced when the concentration exceeded 100 μg/mL with the best reaction time between 4 and 19 hours. Flow cytometry showed that the early apoptosis rate was 45% in the elemene liposome group and only 0.019% in the control group. The early apoptosis rate was signiifcantly higher in treatment group than that in control group (P0.05).Conclusion:Elemene liposome can inhibit human gastric cancer cells at the optimal concentration of 100 μg/mL with the best reaction time between 4-19 hours. Elemene liposome has a clear preventive effect on peritoneal metastasis of human gastric cancer in nude mice. Induction of apoptosis in gastric cancer cells may be the main mechanism underlying the inhibitory effect of elemene liposome on human gastric cancer cells.

Clinical effects of antibiotics compared with appendicectomy for treatment of uncomplicated acute appendicitis: a Meta-analysis / 国际外科学杂志

Objective To compare clinical effects of appendicectomy and conservative treatment of uncomplicated acute appendicitis.Methods Searched The Cochrane library,Medline,Pubmed,Embase,CBM,CNKI,VIP and Wan Fang database in any language.RCTs that compared conservative treatment with appendicectomy in patients with uncomplicated acute appendicitis were included from January 1983 to May 2013 and qualities of the trials were evaluated.Statistic analyses were carried out using RevMan 5.1 soft-ware.Results Four randomized trials met our inclusion criteria (821partiCI:pants).Antibiotics compared with appendicectomy resulted in similar outcomes with regards to the incidence of complicated appendicitis (RR:0.89,95％ CI:0.29-2.68) and intra-abdominal infection(RR:0.54,95％ CI:0.13-2.35).Antibiotics carries a lower risk of complications (RR 0.46,95％ CI:0.32-0.67),but requires more length of hospital stay (Mean Difference 0.52,95％ CI:0.16-0.88).Conclusions The effect of conservative treatment is safe and effective.But the recurrent uncomplicated appendicitis recommends operation.

Application of social media in medical field of China / 中华医学图书情报杂志

After the development of different medical social media in China was summarized , the advantages and trend of social media in medical field of China were analyzed , the challenges facing medical social media were pointed out and their countermeasures were proposed .

Endoscopic balloon sphincter dilation vs.sphincterotomy for common bile duct stones: a Meta analysis / 中华消化内镜杂志

Objective To compare the pros and cons of endoscopic papillary balloon dilation (EPBD) with those of endoscopic sphincterotomy (EST) in the treatment of common bile duct stones.Methods We searched The Cochrane library,Medline,Pubmed,Embase,CBM,CNKI,VIP and Wan Fang database in any language.RCTs that compared EPBD with EST for the removal of common bile duct stones were included from January 1983 to September 2012 and qualities of the trials were evaluated.Statistic analyses were carried out using RevMan 5.1 software.Results A total of 18 randomized trials with 2385 participants met our inclusion criteria.EPBD compared with EST resulted in similar outcomes with regards to stone removal on 1 st attempt,overall stone removal,perforation,total short-term complication,long-term cholangitis or mortality.EPBD carries a higher risk of pancreatitis (RR =1.99,95％ CI:1.41-2.81) and severe pancreatitis (RR =4.68,95 ％ CI:1.36-16.11),and requires higher rates of mechanical lithotripsy (RR =1.31,95％ CI:1.14-1.50).Conversely,EPBD not only has statistically significant lower rates of bleeding (RR =0.14,95％ CI:0.06-0.34),but also leads to significantly less long-term cholecystitis (RR =0.38,95％ CI:0.19-0.76),long-term stone recurrence (RR =0.67,95％ CI:0.47-0.96) and total longterm complications (RR =0.52,95 ％ CI:0.40-0.67).Conclusion On the basis of lower rates of bleeding or long-term complications,EPBD should be the preferred strategy over EST for endoscopic management of common bile duct stones,however,the rate of pancreatitis,especially the severe pancreatitis is higher with EPBD.

Mrp14 is a potential biomarker for biliary tract neoplasms / 中华肝胆外科杂志

ObjectiveTo provide clues to find a biomarker for early diagnosis, prognosis and therapy, as well as to understand the molecular mechanisms governing cancer progression. Methods Surgical specimens were obtained from 87 patients with histopathologically proven malignant or benign lesions. The differential protein profiles of these malignant and benign specimens were detected using two-dimensional electrophoresis (2-DE) combined with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF/MS). Western blotting and immuno-histochemistry were used to validate the results. RT-PCR was used to detect the gene expression in the tissues. ResultsMrp14 was found to be overexpressed in the tumor tissues of gallbladder cancer and extra-hepatic bile duct cancer, and in the bile of patients with malignant biliary tract tumours. The result was further verified using Western blot and immuno-histochemistry. RT-PCR confirmed the overexpression of Mrpl4 at the gene level. Mrp14 is a potential biomarker for biliary tract neoplasms. ConclusionsThis is the first report which described the overexpression of Mrp14 in biliary tract neoplasms and further studies are needed to confirm our findings. Mrp14 may be a potential hiomarker for biliary tract neoplasms. It may provide important clues on the molecular mechanisms governing cancer progression.

Arsenic trioxide inhibits the growth of human gall bladder carcinoma cell and its effect on the cyclin D1 / 中国癌症杂志

Background and purpose:Arsenic trioxide,verified as a breakthrough in the management of acute promyelocytic leukemia,has been applied to a variety of solid tumors.Gall bladder carcinoma,lacking specific clinical manifestations,is usually diagnosed at advanced stages of the diseases and few cases can be resected by operation.Chemotherapy has not shown significant activity in gall bladder carcinoma.This study was to investigate the biological effect of As2O3 on the growth of human gall bladder carcinoma cell and its mechanism.Methods:GBC cells were cultured with different concentrations of As2O3,the proliferative activity of the cells was detected by MTT methods,and the cell cycle status was carried out by flow cytometry(FCM).Western blot and RT-PCR were performed to analyse the expression of cyclin D1,D2,D3,CDK4 and CDK6.GBC cells were transient transfected with cyclin D1 promoter construct pGL3 and then treated by different doses of As2O3.The luciferase activity was measured.Results:The treatment of As2O3 in gall bladder carcinoma cells could inhibit the growth of cells in a time and dose dependent manner,make cells arrest in G1 phase and down regulate the expression of cyclin D1.In addition,the activity of cyclin D1 promoter was down-regulated by As2O3 in a dose-dependent manner and decreased about 70 percent when treated with 4 ?mol/L As2O3.Conclusions:As2O3 can significantly inhibit the growth of human gall bladder carcinoma cells as well as down-regulate the expression of cyclin D1 in vitro.

Progress in effects of the HGF/SF-c-Met on progression of tumors and inhibitors of its pathway / 中国癌症杂志

Over-expression of the HGF/SF-c-Met plays an important role in tumor metastasis. It has been demonstrated that activation of its pathway may promote almost every step of tumor metastasis. Recently, blocking its pathway to prevent tumor cell metastasis has become a focus in anti-tumor studies. This review will address the progress in studies on the effects of HGF/SF-c-Met on growth, invasion, and metastasis of tumors and inhibitors of its pathway.