Two famous historical events which lead to the establishment of the medical ethics committee are presented in this article. We discuss the significance of the medical ethics committee and put forward 5 propositions to enhance the developing of the committee. Firstly, overcome the scruple and accelerate the construction of the medical ethics committee. Secondly, seek for the ethics spirit from the traditional culture, and establish the principles and the conception correspondingly. Thirdly, be creative and try to adapt to the promotion of medicine and society. Fourthly, strengthen the training of bioethics. Finally, promote the communication between ethics review committees.

Abstract: Objective　To identify the species of Mycobacteroides abscessus complex (MABC) in patients with pulmonary infection from the Second Affiliated Hospital of Hainan Medical University, and to investigate the species types, drug sensitivity and population distribution of MABC in pulmonary infection in Hainan. Methods　Respiratory tract specimens were collected from suspected tuberculosis patients who visited the Second Affiliated Hospital of Hainan Medical University from January 2014 to December 2021 and cultured for Mycobacterium isolation. Non-tuberculous mycobacteria (NTM) strains were preliminarily identified by p-nitrobenzoic acid/thiophen-2-carbohydrazide (PNB/TCH) medium and DNA microarray chip, and then MABC and its subspecies were identified by hsp65 and rpoB gene sequencing. In vitro antimicrobial susceptibility test was performed by broth microdilution method. Results　A total of 3 025 respiratory specimens from suspected pulmonary tuberculosis patients were collected during the study period. Among the 123 patients with identified MABC isolates, 124 MABC strains were isolated and identified, including 74 strains of Mycobacteroides abscessus subsp. abscessus, 38 strains of Mycobacteroides abscessus subsp. massiliense and 12 strains of Mycobacteroides abscessus subsp. bolletii. Among them, 118 patients had single MABC subspecies infection, one patient had mixed infection with two MABC subspecies, two patients had mixed infection with MABC and other NTM, and two cases had mixed infection with MABC and M.tuberculosis. There were more female patients than male patients with a ratio of 1:0.64, and those aged 50 and above amounted to 76.42% (94/123, 95%CI: 67.93%-83.61%). There was no significant difference in age distribution between male and female patients (Z=-0.944, P=0.347). The drug susceptibility results showed that all MABC strains were sensitive to Tigecycline (TGC), with a resistance rate of 0.81% (1/124) to Amikacin (AK), and resistance rates of 6.45% (8/124), 32.26% (40/124), and 74.19% (92/124) to Cefoxitin (FOX), Linezolid (LZD), and Imipenem (IPM), respectively. For Clarithromycin (CLR), MABC showed induced resistance , and there was a statistically significant difference in the CLR (14D) resistance rates among the three subspecies (χ2=66.335, P<0.001). The resistance rates to Tobramycin (TOB), Doxycycline (DOX), Moxifloxacin (MFX), Ciprofoxacin (CIP), Trimethoprim/Sulfamethoxazole (TMP-SMX), and Amoxicillin/Clavulanic acid (AMC) were high, all >80%. Conclusion　 In Hainan Province, pulmonary infections with MABC are mainly caused by Mycobacteroides abscessus subsp. Abscessus, which show high rates of inducible resistance to CLR. Timely and accurate identification of MABC to subspecies and drug susceptibility testing are of significant important for clinical decision-making.

Rabbit hemorrhagic disease (RHD) is contagious and highly lethal. Commercial vaccines against RHD are produced from the livers of experimentally infected rabbits. Although several groups have reported that recombinant subunit vaccines against rabbit hemorrhagic disease virus (RHDV) are promising, application of the vaccines has been restricted due to high production costs or low yield. In the present study, we performed codon optimization of the capsid gene to increase the number of preference codons and eliminate rare codons in Spodoptera frugiperda 9 (Sf9) cells. The capsid gene was then subcloned into the pFastBac plasmid, and the recombinant baculoviruses were identified with a plaque assay. As expected, expression of the optimized capsid protein was markedly increased in the Sf9 cells, and the recombinant capsid proteins self-assembled into virus-like particles (VLPs) that were released into the cell supernatant. Rabbits inoculated with the supernatant and the purified VLPs were protected against RHDV challenge. A rapid, specific antibody response against RHDV was detected by an ELISA in all of the experimental groups. In conclusion, this strategy of producing a recombinant subunit vaccine antigen can be used to develop a low-cost, insect cell-derived recombinant subunit vaccine against RHDV.
Animals ; Antigens, Viral/genetics/metabolism ; Caliciviridae Infections/prevention & control/*veterinary/virology ; Capsid Proteins/*genetics/metabolism ; Cell Culture Techniques/*methods ; Codon/genetics/metabolism ; Enzyme-Linked Immunosorbent Assay/veterinary ; *Gene Expression Regulation, Viral ; Hemorrhagic Disease Virus, Rabbit/*genetics/immunology ; *Rabbits ; Recombinant Proteins/genetics/metabolism ; Sf9 Cells ; Spodoptera ; Viral Structural Proteins/*genetics/metabolism ; Viral Vaccines/genetics/immunology

Objective: To investigate eye care behaviors among primary students in Wenzhou during Novel Coronavirus epidemic(COVID-19),and to provide a basis for eye care education and myopia prevention strategy. Methods: A total of 1 127 students from grade one to grade six of six primary schools in Wenzhou were selected to participate in an on-line invistigation regarding class attendance and eye care behaviors during the epidemic, March 6-9, 2020. Results: During the epidemic period, the primary school students in Wenzhou mainly took classes on the Internet (936, 83.1%), and the main learning tools were computers (391, 34.7%) and mobile phones (344, 30.5%), with an average of 3.00 h of online class. On average, students needed 2.00 h to complete homework and 1.00 h of extracurricular reading every day. In addition to learning, the daily use of mobile phone or ipad, computer and TV was 1.00,0.50,1.00 h respectively. Limited by the epidemic situation, the average daily exercise time of students was 0.81 h, including 0.00 h of outdoor activities; the average daily sleep was 9.00 h . During the epidemic period, 553 pupils (49.1%) reported eye discomfort, of which the most common was dry eyes (379, 47.4%). Multivariate Logistic regression analysis showed that the main learning tools of non-electronic products, reading distance > 30 cm or not reading, exercise time >0.5 h and outdoor activity time > 0.5 h were the protective factors of ocular discomfort (P<0.05). More than 2 h homework and recreational screen time higher than 0.5 h were risk factors for ocular discomfort(P＜0.05). Conclusion During the epidemic period, online learning increasedeye strain.Time of electronic devices usage,correct posture for reading,moderate level of ourdan physical activity,as well as prevention and treatment of eye strain should be strictly monitored.

Objective: To determine the serotypes and drug resistance profiles of Shiga toxin-producing Escherichia coli (STEC) in animal stools from the Weishan area in Shandong Province, China. To provide the basis for further study. Methods: Five hundred animal stool samples (from pigs, cattle, sheep, dogs and birds) were collected from the Weishan area and STEC strains were isolated from these samples. Strains were serotyped by a serum agglutination test, and their drug resistance profiles were determined through antimicrobial sensitivity experiments. In this study, PCR was used to detect tetracycline resistance genes (tetA, tetB, tetC, tetD) and beta-lactam resistance genes (blaSHV-1, blaCTX-M, blaTEM). Results: Sixteen strains of STEC were isolated from animal stool samples. Thirteen strains were isolated from pig stool samples, two from bovine stool samples and one from a sheep stool sample. Two of the strains were identified as E. coli O157:H7, and other 14 strains were non-O157 STEC of different serotypes. Antimicrobial sensitivity experiments showed that 15 of the strains were multidrug resistant. The rates of resistance were as follows: nalidixic acid (12/16 strains), sulfisoxazole (11/16), trimethoprim and sulphame-thoxazole (11/16), doxycycline (9/16), azithromycin (9/16), tetracycline (9/16), chloramphenicol (8/16) and streptomycin (8/16). Therefore, nalidixic acid showed the highest rate of resistance among the strains, followed by trimethoprim and sulphame-thoxazole, and sulfisoxazole. Resistance to cefepime or imipenem was not detected. In total, three types of drug resistance genes (tetA, tetB and tetC) were detected among the 16 strains. Conclusion The results showed that STEC strains isolated from animals in the Weishan area were of a range of serotypes. The 16 strains of STEC isolated from animal stools in this area were resistant to a number of antibiotics, with many strains displaying multidrug resistance.

Objective:To study the safety factors of Fuyanyu mixture. Methods: The contents of antiseptic and residual ethanol were determined by HPLC and GC, respectively, and those of heavy metals and harmful elements were detected by ICP-MS. Results:The contents of benzoic acid in 6 batches of samples were less than 0. 3%. In two thirds of samples, ethanol residue was more than 0. 5%. The total mercury exceeded 15μg/day in one of the samples, and the contents of Pb, Ge, Gr, As, Ni and Cu met the limits described in USP<232> in all of the last samples. Conclusion: The methods are accurate and reliable. It is urgent to improve the preparation process so as to reduce the residual amount of ethanol according to the detection results. It is recommended to increase the testing items that affect the safety of the preparation so as to control the preparation quality strictly.

Objective:To study the safety factors of Fuyanyu mixture. Methods: The contents of antiseptic and residual ethanol were determined by HPLC and GC, respectively, and those of heavy metals and harmful elements were detected by ICP-MS. Results:The contents of benzoic acid in 6 batches of samples were less than 0. 3%. In two thirds of samples, ethanol residue was more than 0. 5%. The total mercury exceeded 15μg/day in one of the samples, and the contents of Pb, Ge, Gr, As, Ni and Cu met the limits described in USP<232> in all of the last samples. Conclusion: The methods are accurate and reliable. It is urgent to improve the preparation process so as to reduce the residual amount of ethanol according to the detection results. It is recommended to increase the testing items that affect the safety of the preparation so as to control the preparation quality strictly.

Activation-induced cytidine deaminase (AID) is required for the generation of antibody diversity through initiating both somatic hypermutation (SHM) and class switch recombination. A few research groups have successfully used the feature of AID for generating mutant libraries in directed evolution of target proteins in B cells in vitro. B cells, cultured in suspension, are not convenient for transfection and cloning. In this study, we established an AID-based mutant accumulation and sorting system in adherent human cells. Mouse AID gene was first transfected into the human non-small cell lung carcinoma H1299 cells, and a stable cell clone (H1299-AID) was selected. Afterwards, anti-hTNF-α scFv (ATscFv) was transfected into H1299-AID cells and ATscFv was displayed on the surface of H1299-AID cells. By 4-round amplification/flow cytometric sorting for cells with the highest affinities to hTNF-alpha, two ATscFv mutant gene clones were isolated. Compared with the wild type ATscFv, the two mutants were much more efficient in neutralizing cytotoxicity of hTNF-alpha. The results indicate that directed evolution by somatic hypermutation can be carried out in adherent non-B cells, which makes directed evolution in mammalian cells easier and more efficient.
Animals ; Antibody Affinity ; Cells, Cultured ; Cytidine Deaminase ; genetics ; metabolism ; HEK293 Cells ; Humans ; Immunoglobulin Variable Region ; genetics ; immunology ; Mice ; Mutation ; Single-Chain Antibodies ; chemistry ; genetics ; immunology ; Somatic Hypermutation, Immunoglobulin ; genetics ; immunology ; Tumor Necrosis Factor-alpha ; immunology

Objective: To understand the infection status, characteristics and drug resistance of non-O157 Shiga toxin-producing E. coli (STEC) in animal feces in Shandong Province. Methods: From 2015 to 2016, convient sampling method was used to collect 1 022 fresh feces of animals in Weishan county and Laizhou city, and 24 non-O157 STEC were isolated. The serotypes of non-O157 STEC strains were confirmed through serum agglutination test. The susceptibility was explored through the antimicrobial sensitivity experiments. ESBLs activity was confirmed by double-disc diffusion. PCR method was used to detect the resistance genes. PFGE typing was operated to assess the relatedness and variability of the strains. The multi-locus sequence typing (MLST) was adopted to get the allelic profile and ST sequence of strains. Analysis was made on the evolutionary relationship between different ST groups was made through CLC Sequence Viewer and Counting Express. Results: A total of 24 non-O157 STEC were isolated from animal feces. 23 strains were from pig feces, and 1 strain was from cow feces, and the serotypes were more dispersed. All of the 24 strains carried stx2 genes. The highest resistance rate was sulfamethoxazole(22 strains), the mount of cotrimoxazole and nalidixic acid was 18 strains, chloramphenicol was 13 strains, tetracycline was 19, and there was a phenomenon of multiple drug resistance. The drug resistance spectrum was sulfamethoxazole tetracycline-compound novammin-naphthidine-chloramphenicol. All strains were sensitive to cefepime and imipenem. The ESBLs confirmatory test showed that 4 strains of non O157 STEC produced beta lactamase. PCR detected 7 resistance genes, and 4 tetracycline resistance genes (Tet A, Tet B, tetC and tetD) were detected. The beta lactamase resistance genes (blaSHV-1, bla CTX-M, bla TEM) were all negative. 24 strains were divided into 15 PFGE types, and their clustering results were more dispersed and no dominant PFGE type. There were 11 kinds of MLST types, most of them are ST540 and ST5133 types, each of which was 4 strains, and clustered into 1 MLST genomes. Conclusion The serotypes of non-O157 STEC in animal feces O157 STEC were dispersed, and the resistant rate to common antibiotic was high. MLST typing results presents obvious polymorphism. Surveillance and manage ment of these strains should be strengthened.