Developing and implementing biosafety standards for pathogenic microbiology laboratories is essential to achieving scientific, efficient, and standardized management and operation. This article analyzes the current standardization construction in biosafety in pathogenic microbiology laboratories domestically and internationally. It proposes a framework for the biosafety standard system of pathogenic microbiology laboratories, which mainly includes four parts: basic standards, management standards, technical standards, and industry applications. It provides a reference for the standardization work of pathogenic microbiology laboratories and helps to standardize the biosafety industry in China.

Organ preservation fluid could mitigate cold ischemia injury and maintain normal function of the grafts. At present, how to reduce a series of injury caused by cold ischemia of donor liver and improve the preservation quality of grafts are the hot and challenging spots in this field. Currently, preservation fluid in clinical practice has not achieved ideal preservation effect, especially for the protection of marginal donor organs. In the context of severe donor shortage, the key solution is still to explore the optimal preservation protocol for donor liver to prevent grafts from cold ischemia injury. In this article, the mechanism of donor liver injury during cold ischemia, the classification and evolution of donor liver preservation fluid were summarized, the development direction and challenges of donor liver preservation fluid were discussed, aiming to provide novel ideas and references for the research and development of donor liver preservation fluid.

BACKGROUND:Currently,there is a lack of large sample studies to analyze the bone metabolism level of patients with femoral head necrosis of different etiologies and stages,which is not conducive to the development of better necrosis-promoting repair strategies. OBJECTIVE:To study the bone metabolism of patients with osteonecrosis of the femoral head with different etiologies and Association Research Circulation Osseous(ARCO)stages. METHODS:A retrospective study was performed on 401 patients diagnosed with osteonecrosis of the femoral head as the trial group,and 81 healthy subjects as the control group.The trial group could be divided into three groups according to different etiologies:steroid-induced osteonecrosis of the femoral head,alcoholic osteonecrosis of the femoral head and traumatic osteonecrosis of the femoral head,and were divided into stages Ⅱ/Ⅲ/Ⅳ according to different ARCO stages.Seven bone metabolism-related indicators of all subjects were collected,including bone metabolism-regulating hormone 25-hydroxyvitamin D and bone conversion markers:N-terminal propeptide of type Ⅰ procollagen,degradation product of type Ⅰ collagen,n-terminal middle molecular fragment of osteocalcin,general biochemical markers of bone metabolism:serum calcium,serum phosphorus,serum alkaline phosphatase.The bone metabolism levels of each group were compared and the independent factors associated with osteonecrosis of the femoral head were determined by binary Logistic regression analysis. RESULTS AND CONCLUSION:Compared with the control group,levels of degradation product of type Ⅰ collagen,N-terminal propeptide of type Ⅰ procollagen,n-terminal middle molecular fragment of osteocalcin,serum phosphorus and alkaline phosphatase in the trial group were significantly increased(all P＜0.05).Based on the presence or absence of the disease,according to binary Logistic regression analysis,degradation product of type Ⅰ collagen,N-terminal propeptide of type Ⅰ procollagen,and n-terminal middle molecular fragment of osteocalcin were independent factors associated with osteonecrosis of the femoral head.The levels of degradation product of type Ⅰ collagen and N-terminal propeptide of type Ⅰ procollagen in three groups of patients with different etiologies were higher than normal reference values.The bone metabolism-regulating hormone 25-hydroxyvitamin D and serum calcium in the alcoholic osteonecrosis of the femoral head group were higher than those in the other two groups(P＜0.05).The level of bone metabolism-regulating hormone 25-hydroxyvitamin D in steroid-induced and traumatic osteonecrosis of the femoral head groups was lower than the normal value.There were no significant differences in seven bone metabolism-related indicators in patients with ARCO stages Ⅱ,Ⅲ and Ⅳ osteonecrosis of the femoral head(all P＞0.05),but degradation product of type Ⅰ collagen and N-terminal propeptide of type Ⅰ procollagen in these three groups were higher than normal reference values.Bone metabolism-regulating hormone 25-hydroxyvitamin D in patients with ARCO stage Ⅱ and ARCO stage Ⅳ was lower than the normal reference value.It is concluded that the bone metabolism level of osteonecrosis of the femoral head patients was abnormal.The degradation product of type Ⅰ collagen and N-terminal propeptide of type Ⅰ procollagen of osteonecrosis of the femoral head patients with different etiologies and ARCO stages were all higher than the normal reference value,and they were in a state of high bone turnover.Degradation product of type Ⅰ collagen,N-terminal propeptide of type Ⅰ procollagen and n-terminal middle molecular fragment of osteocalcin may be risk factors for the pathogenesis of osteonecrosis of the femoral head.

Human immunodeficiency virus (HIV) strains are important national biological resources, and the establishment of HIV standard strains forms material basis for HIV diagnostic testing, epidemic surveillance, disease prevention and control, reagent evaluation, drug research and vaccine development. The National Center for AIDS/STD Control and Prevention of China took the lead in development and publication of the Chinese Preventive Medicine Association (CPMA) group standard, Standard strains of pathogenic microorganism-technical specifications for establishment of HIV strains (T/CPMA 027—2023). Published on February 2, 2023, the standard, for the first time, specifies all technical requirements for establishment of HIV standard strains, covering sampling, isolation, culture, titration, identification, evaluation, preservation, archiving, quality control and biosafety management, and it also standardizes HIV isolation and characterization procedure, and relevant information description. This paper provides in-depth views on development of HIV standard strains, formulation and application of relevant standards, in order to pave solid ground for establishment of HIV standard strain banks and improvement of repository quality control, utilization and biosafety management.

Objective:To construct standard strains representing the main epidemic clades of HIV-1 in China, amplify the virus strains, and establish a seed lot.Methods:Six isolates of HIV-1 virus were identified and analyzed in genotype and phenotype, according to " interpretation for the social organization of the Standard strains of pathogenic microorganism- technical specifications for establishment of HIV strains". The isolates were amplified and cultivated to generate the secondary generation primary seed lot and the third generation working seed lot as frozen storage in liquid nitrogen. Results:Six HIV-1 standard strains were obtained, of which 3 strains are CRF_ 07BC (NRPC2.4.9003, NRPC2.4.9005, NRPC2.4.9006), 1 strain is CRF_ 01AE (NRPC2.4.9001), 1 strain is CRF_ 08BC (NRPC2.4.9002), and 1 strain is URF (NRPC2.4.9004). Phenotypic detection showed that all six strains are CCR5 tropics and Non syncytia inducing virus. TCID 50 were all greater than 1 × 10 5/ml, and concentrations of p24 antigen were all higher than 2 ng/ml. A primary seed lot with no less than 20 vials per strain and a working seed lot with no less than 50 vials per strain were constructed. The standard virus strains were used in evaluating antiviral drugs PEG2kC34, PEG5kC34, LP-19, and neutralizing antibody LSEVh LS-F. Conclusions:Six standard strains of HIV-1 virus covering the three main epidemic subtypes of HIV-1 in China have been obtained, and a storage of HIV-1 standard strain was constructed. It meets the need of the preservation of HIV-1 standard strains in China and provides support for drug and vaccine evaluation.

Objective:To screen the HIV standard strains with typical biological characteristics of HIV strains circulating in China through the isolation, culture, genotype and phenotype identification of HIV from the whole blood samples of HIV-infected persons, confirm genetic characteristics, traceability, and in line with the Standard Strains of Pathogenic Microorganism-technical Specifications for Establishment of HIV Strains (T/CPMA 027—2023).Methods:Whole blood samples were collected from 48 HIV infected patients. Peripheral blood mononuclear cells (PBMCs) were isolated from the samples and co-cultured with PBMCs isolated from healthy persons′ whole blood samples to isolate and culture HIV from infected persons. We determined concentration of p24 antigen and the virus titer in the culture supernatant. The viral RNA was extracted from the successfully isolated strains, and the gag, pol genes and env C2V3 fragments of the viral genome were amplified and sequenced. The genotype, gene recombination and drug resistance sites were determined according to the viral gene sequences. Virus infection and replication were monitored by inoculating the virus culture supernatant into Ghost cells expressing CCR5 or CXCR4 to determine the viral tropism.The formation of syncytium was observed by inoculating the virus culture supernatant into MT-2 cells to determine whether was a syncytium-induced phenotype. Results:Fourteen strains with p24 antigen concentration > 1 ng/ml in culture supernatant were isolated and cultured from 48 fresh EDTA anticoagulated whole blood samples of HIV infected persons. Of the 14 strains, only one strain with a titer≥10 5 TCID 50/ml, 8 strains with titers ≥10 4 TCID 50/ml, and the other 5 strains with titers≥10 3 TCID 50/ml. Phylogenetic analysis showed that the genotypes of the strains were 9 strains of subtype B, 3 strains of CRF01_AE and 2 strains of CRF07_BC recombinant. Genotypic resistance analysis showed that 11 strains contained drug resistance sites. Ghost cells were used to verify the tropism of the strains, and it was found that 8 strains were CCR5 tropism, 6 strains were CXCR4 & CCR5 dual tropism. Only 2 of the 14 strains could induce MT-2 cytopathic effect, which was syncytium-inducing phenotype. Conclusions:Fourteen HIV strains with typical biological and genetic characteristics were isolated to screen the standard HIV strains. Among which, 1 strain was evaluated as a standard HIV strain that meets the Standard Strains of Pathogenic Microorganism-technical Specifications for Establishment of HIV Strains (T/CPMA 027—2023). This study can also provide technical guidance for the screening of the HIV standard strains. Next step is to complete the application and reserve database construction according to the sharing mechanism of the HIV standard strains, to provide resources for the researches of HIV vaccines and drugs.

Background: Gastric cancer is one of the common gastrointestinal malignancies. Early diagnosis can reduce the mortality rate significantly. In the Chinese consensus published in 2017, the New Gastric Cancer Screening Scoring System was recommended to be used for risk stratification of gastric cancer. Aims: To preliminarily explore the value of the New Gastric Cancer Screening Scoring System in early gastric cancer screening in asymptomatic community population. Methods: At several communities in Suzhou City Xiangcheng District, a questionnaire survey was conducted in asymptomatic community residents willing to accept voluntary serum tests to collect information on high risk factors of gastric cancer. Serum pepsinogen (PG), PGⅡ, gastrin 17 (G-17) and Helicobacter pylori (Hp) IgG were tested simultaneously. Risk stratification of gastric cancer was carried out in accordance with the New Gastric Cancer Screening Scoring System. Gastroscopy was recommended for moderate to high risk individuals. Results: A total of 540 asymptomatic individuals completed the study, of which 11 were categorized as high risk (2.0%), 168 as moderate risk (31.1%), and 361 as low risk (66.9%). Sixty-four moderate to high risk individuals completed the gastroscopy with a response rate of 35.8%. Four precancerous lesions were detected (6.2%), including 3 gastric low-grade intraepithelial neoplasia and 1 duodenal adenoma. No gastric cancer was detected. Conclusions: The New Gastric Cancer Screening Scoring System is useful for risk stratification of gastric cancer in asymptomatic population and may provide a basis for further endoscopic examination. However, the value of this scoring system in low risk areas of gastric cancer needs to be further verified.

Objective To investigate the clinical effect of percutaneous hollow screw combined with tension band internal fixation for comminuted patellar fracture after arthroscopic reduction.Methods 105 patients with comminuted patellar fracture in our hospital from April 2013 to September 2017 were selected and divided into observation group (n =53) and control group (n =52) according to different treatment schemes.The control group was treated with conventional open reduction and Kirschner wire combined with tension band internal fixation,while the observation group was treated with arthroscopic assisted reduction and percutaneous cannulated screw combined with wire tension band internal fixation.The operation status and postoperative fracture healing time of the two groups were compared.One-year follow-up was performed after operation.The incidence of complications,the excellent and good rate of operation,and the preoperative and postoperative pain scores (VAS) and knee were compared.Hospital for special surgery knee score (HSS),Activity of Daily Life Scale (ADL),quality of life score (the Mos 36-item Short Form Health Survey,SF-36) were compared.Results The observation group had fewer fluoroscopy times during operation,shorter incision length and shorter healing time after operation than the control group (P ＜ 0.05);the incidence of complications in the observation group was 3.85％,lower than 20.00％ in the control group,and the excellent and good rate of operation was 96.15％,higher than 82.00％ in the control group (P ＜ 0.05);the VAS scores of the two groups were lower than those of the control group one year after operation,and the scores of HSS,ADL and SF-36 were lower than those of the control group.The preoperative improvement was higher in the observation group than in the control group (P ＜ 0.05).Conclusions Arthroscopic reduction combined with percutaneous hollow screw and tension band internal fixation for patellar comminuted fracture can reduce surgical trauma and accelerate the rehabilitation of patients.It can reduce the incidence of complications,relieve pain,improve knee function,daily living ability and quality of life,and the effect is remarkable.

Background: Colorectal cancer (CRC) is a commonly seen cancer, and is a heterogeneous disease entity with a diverse biological pathogenesis. Aims: To investigate the expressions of mismatch repair protein (MMRP) and Ki-67 in CRC, and analyze the correlations of microsatellite instability (MSI), Ki-67 with clinicopathological features of CRC. Methods: Clinicopathological data of 90 CRC patients from Jan. 2014 to Dec. 2016 at the First Affiliated Hospital of Soochow University were retrospectively analyzed. Immunohistochemical staining was used to detect the protein expressions of 4 MMRP (MLH1, PMS2, MSH2 and MSH6) and Ki-67 in CRC patients. Correlations of MSI, Ki-67 with clinicopathological features of CRC patients were analyzed. Correlation of MSI with Ki-67 was also analyzed. Results: The loss expression rate of MMRP was 16.7%, and that of MLH1, PMS2, MSH2 and MSH6 were 11.1%, 11.1%, 6.7% and 4.4%, respectively. Positivity rate of Ki-67 was 90.0%. MSI was correlated with tumor location (P<0.05), and expression of Ki-67 was correlated with tumor location and gross type (P<0.05). MSI was not correlated with expression of Ki-67 (P>0.05). Expression of MLH1 was positively correlated with expression of PMS2 (r=0.577, P<0.05), and expression of MSH2 was positively correlated with expression of MSH6 (r=0.739, P<0.05). Conclusions: The loss expressions of MLH1, PMS2 are more common than those of MSH2, MSH6 in CRC. MSI is correlated with tumor location and Ki-67 is correlated with tumor location and gross type; they may be of some significance for the diagnosis and prediction of prognosis of CRC. However, MSI is not correlated with Ki-67, and joint detection of MMRP and Ki-67 could not improve the diagnostic accuracy of CRC.

Objective To investigate college students' awareness and cognition of 84 shared courses on the Internet and analyze the discrepancies between different ethnicity and majors in Xinjiang Medical University. Methods Purposive sampling was adopted with questionnaire of 1 448 students of 26 classes in Xinjiang Medical University. The survey aimed to investigate students' awareness and cognition of these In- ternet courses. Obtained data were statistically analyzed using SPSS 13.0, and the test level α=0.05. Result The hits of preventative medicine, Chinese medicine, clinical medicine and pharmacy were 19.0%, 33.3%, 35.7% and 11.9% respectively. Among the courses whose hits exceeded 50,000, clinical medicine accounted for 50%, preventive medicine for 21.4%, Chinese medicine and pharmacy for 14.3% respectively, there being no significant difference in overall hits (P>0.05). 90.1% of the surveyed students knew shared courses on the Internet, there being no difference between gender, ethnicity and profession (P>0.05). 89.8% had an accurate understanding of the concept of shared courses on the Internet, there being differences between gender and major ( χ2gender=11.013, P=0.026; χ2major=136.08, P=0.000) without significant differences in ethnicity ( χ2=11.378, P=0.497). 71.9% of the students used shared courses on the Internet as reference resources for the course study, 46.6% for the learning content, 35.5%for the understanding of other resources related to the course, 30.1% for lab-class and exercises, 10% for discussion on online course forum. The Han and Kazak students used the courses as a study, experiment and exercise tool, while the Uyghur and Kazak mainly used these for learning and discussion on the forum, there being differences in ethnicity ( χ2=26.889, P=0.001); the usage rate of the courses of preventive medicine students is higher, whereas pharmacy students relatively low, there being significant differences in major ( χ2=38.01, P=0.004). The Kazakh and Uygur students mainly used the courses to formulate learning plans, and the Han students to learn the current curriculum. 44.7% of preventive medicine students used the courses to improve their abilities, which was significantly higher than those of other majors. Only 18.4% and 1% of pharmacy students used the courses to formulate learning plans and to improve their abilities, which were both lower than those of other majors, showing ethnic and professional differences ( χ2ethnic=37.654, P=0.001; χ2major=73.68, P=0.000). Conclusion Students' awareness of shared courses on the Internet is high and their cognition is accurate. However, there are differences in the ways and purposes of the employment of the courses between different ethnicity and majors. The main reason may be related to major, the quality of the courses, as well as the lack of effec-tive supervision and evaluation system, suggesting that the management department in our university should strengthen the supervision and evaluation of the courses and give full play to the important role of shared courses on the Internet.