Objective　To compare the endocytic routes of exogenous antigen between murine dendritic cells (DCs) and macrophages (Mφs). Methods　Murine bone marrow-derived DCs and peritoneal Mφs were pulsed with horseradish peroxidase (HRP)-5 nm colloidal gold for 10 minutes, then grouped and chased for 0-120 minutes in culture medium. Intracellular distribution of 5 nm colloidal gold was explored by means of the cellular enzymatic-chemistry of acid phosphatase and MHC Ⅱ immuno-cytochemistry under electron microscope. Results　After 10 minutes of pulse with HRP-5 nm colloidal gold and 30 minutes of chase, most HRP-5 nm gold particles internalized by DCs entered into MHC class Ⅱ compartments (MⅡCs), and a small portion entered into acid phosphatase-positive lysosomes. In contrast to DCs, most Mφs lysosomes were accessed by HRP-5 nm gold particles, and a small portion of HRP-5 nm gold particles entered into MⅡCs. After 60 minutes of chase, 5 nm gold particles could hardly be seen within Mφs, whereas most 5 nm gold particles were still retained in DCs. Conclusions　The endocytic route of exogenous antigen in DCs seems to be different from that in Mφs. Antigens taken by Mφs mainly enter into lysosomes within 30 minutes. In the case of DCs, most internalized antigens enter into MⅡCs, which may be related to their unique antigen-presenting function . In addition, Mφs seem to have more powerful capacity to scavenge exogenous antigen than DCs.

Objective To study the difference between piperacillin-tazobactam and other anti-infective agents in the treatment of blood stream infection caused by extended spectrum beta-lactamase (ESBL )-producing Enterobacteriaceae by systematic review and meta-analysis . Methods PubMed , Cochrane library ,Web of Science , CNKI , Weipu DATA , and CPVIP were systematically searched . Literatures were reviewed and data regarding mortality of mono -drug treatment with different antibiotics were collected . All data were pooled using the technique of meta-analysis by Revman 5 .3 , and heterogeneity tests were performed .Results Eleven articles containing 1620 patients were included . Escherichia coli and K lebsiella pneumonia were the main pathogens ,and there were 31 cases caused by Enterobacter cloacae .There was no statistically significant difference in mortality between carbapenems and piperacillin-tazobactam mono-therapy for the empirical treatment (RR = 0 .86 ;95％ CI :0 .62 - 1 .20 , P> 0 .05) or for definitive treatment (RR = 0 .63 ;95％ CI :0 .20 - 1 .97 ,P > 0 .05) .Carbapenems were used as the main antibiotics for definitive treatment as well as empirical treatment . Conclusion Piperacillin-tazobactam treatment is not associated with increased mortality of the patients with ESBL -positive enterobacteria bloodstream infection ,which can be used as an alternative antibiotics .

Objective:To investigate the epidemiological characteristics of community acquired pyogenic liver abscess (CA-PLA) as a reference for its early identification, early diagnosis and rational antibacterial treatment.Methods:A single center retrospective study was carried out in patients with CA-PLA hospitalized in First Hospital of China Medical University from January 2011 to December 2017.The symptoms, signs and treatment results were concluded. The underlying diseases and onset symptoms of the cases were grouped by year, and the change trend of the disease characteristics was analyzed. The etiology results were grouped according to whether the patients had underlying diseases of biliary tract, and the etiology characteristics were analyzed. Statistical analysis was performed by using chi-square test.Results:A total of 1 063 CA-PLA cases were included in this study. The analysis on underlying diseases grouped by year showed that the number of patients admitted to the hospital increased annually, and the percentage of patients with underlying hepatobiliary diseases decreased from 17.3% (19/110) in 2011 to 7.3% (14/191) in 2017, the difference was statistically significant ( χ2=13.648, P=0.034), while that of patients with diabetes mellitus kept high at 31.6% to 46.5% in the past seven years without increasing trend. There were 274 patients (25.8%) with extrahepatic manifestations. Totally 445 cases were microbiologically diagnosed, among which single Klebsiella pneumoniae infection was found in 371 cases (83.4%). Klebsiella pneumoniae was the leading pathogen in patients without underlying hepatobiliary diseases (91.6%, 362/395), in contrast to 18.0%(9/50) in patients with underlying hepatobiliary diseases. The other pathogens were Escherichia Coli (32.0%, 16/50) and mixed infection (18.0%, 9/50). The susceptibility rate to second generation and above cephalosporins of clinically defined hypervirulent Klebsiella pneumoniae was ≥97.5%, and that to carbapenems was 100.0%. Most patients had good prognosis, and 1 049 cases were cure or improvement discharged, six cases left hospital voluntarily, and eight cases died. Conclusions:Most of the CA-PLA patients have no underlying hepatobiliary diseases, and more than half of patients have no history of diabetes mellitus. Most of the pathogens are Klebsiella pneumoniae, which are relatively sensitive to antimicrobial agents.

With improvements in information technology and expansion in education reforms, more innovative teaching reform programs have also been launched. Information technology has increased interest in the use of the flipped classroom innovative teaching model. In order to explore new ideas for the improvement of teaching, this paper focuses on the flipped classroom teaching approach with the integration of information technology. Micro-teaching is an important innovative flipped classroom teaching approach with a number of advantages as it is short, concise, and interesting, which therefore helps improve students' self-learning ability. Designing and preparing micro-teaching would become a prerequisite skill for college teachers. Based on the analysis of the entries in the "National Universities Micro-teaching Competition of Life Science", this paper explores the application of micro-teaching in life sciences teaching from the perspective of curriculum introduction, mode of presentation, teaching design, and other aspects of teaching. This information could serve as a guide to frontline college teachers to help them understand and master the skills of designing micro-teaching, so as to generate interest and improve learning efficiency among college students.
Biological Science Disciplines ; Curriculum ; Humans ; Learning ; Students ; Universities