Objective: To reduce the residual proteins and DNA of host cells in the preparation of H5N1 influenza A virus. Methods: Core 700 was firstly used to remove residual host cell proteins, and then Capto Q was used to remove host cell DNA. Several batches of H5N1 influenza A virus cultured in Madin-Darby canine kidney (MDCK) cells were purified using this method. The efficiency of purification was evaluated using many methods including quantitative real-time PCR, hemagglutination (HA) test and single radial immunodiffusion assay. Moreover, Benzonase nuclease was used for comparison. Results: Without the use of Benzonase nuclease, the overall removal rates of host cell DNA and residual proteins were 99.62% and 98.1%, and the HA antigen recovery rate was 66.96%. Conclusions This study established a purification strategy with good effect for cell-based influenza vaccines. It can efficiently remove host cell DNA and proteins and achieve a high HA recovery rate. The purification result is no worse than that of adding Benzonase nuclease, suggesting the potential of its application in actual vaccine production.

Objective: To investigate the best amount of TPCK trypsin in Madin Darby canine kidney (MDCK) cell suspension for the culture of H7N9 avian influenza virus. Methods: Different concentrations of TPCK trypsin were added during the periods of cell growth and virus production. Their effects on cell growth, viability, glucose and lactate metabolism, and hemagglutination titer were monitored every 12 h. Inter-batch differences were analyzed. The amount of trypsin added in the cell growth phase was 0, 1 μg/ml, 2 μg/ml, 4 μg/ml, 6 μg/ml, 8 μg/ml, 10 μg/ml and 15 μg/ml. The amount of trypsin added during the virus production period was 0, 0.5 μg/ml, 1 μg/ml, 1.5 μg/ml, 2 μg/ml and 2.5 μg/ml. When the hemagglutination titers were same, the adding amount was further optimized at different multiplicity of infection (MOI) of 0.001, 0.005, 0.025 and 0.05. Results: No significant linear effects of TPCK trypsin concentration on cell number, viability, and glucose and lactate metabolism were observed. No toxicity to cell growth was observed when TPCK trypsin concentration reached 15 μg/ml. After the inoculation of H7N9 avian influenza virus, the hemagglutination titers in the 1 μg/ml, 1.5 μg/ml, 2 μg/ml and 2.5 μg/ml TPCK trypsin groups reached the peaks at 48 h, which were 1∶2^6.5. At 60 h, the hemagglutination titers of the latter two groups decreased faster than those of the former two groups. When the MOI was 0.005, the hemagglutination titer of the 1.5 μg/ml group at 48 h was 2^6.5 higher than 2⁶ in the 1 μg/ml group under the same condition. There were differences between different batches of TPCK trypsin. Conclusions Adding 1 μg/ml and 1.5 μg/ml of trypsin could better promote the proliferation of H7N9 avian influenza virus, and 1.5 μg/ml of trypsin had a wider range of MOI applicability.

Objective To screen a Madin-Darby canine kidney (MDCK) cell line for H5N1 influ-enza virus isolation and to evaluate its safety in vaccine production. Methods MDCK cells were cloned by the method of limiting dilution. Hemagglutination test was used to screen MDCK cells that were suitable for H5N1 influenza virus production. Tests for analyzing the characteristics, extraneous agents, endogenous agents and tumorigenicity of MDCK cells were performed according to Chinese Pharmacopeia Volume Ⅲ. Results A total of 108 MDCK cell lines were obtained and three of them were selected after hemagglutina-tion test. G1 cells were chosen following further screening with tumorigenicity test and receptor abundance analysis. The average number of chromosomes of the MDCK-G1 cells was 78±4. No bacteria, fungi or myco-plasma contamination was detected. In experimental group, each nude mouse was injected with 1×107/ml viable cells to observe their tumorigenicity. Twelve weeks after cell injection, no node was found at injection sites or in gross anatomy. There was no significant difference between the experimental and negative control groups. The result of the tumorigenicity test was negative. No node formation was found after injecting nude mice with cell lysate or cellular DNA collected from equivalent amount of cells. It was indicated that the MDCK-G1 cells were of low-oncogenic potential. Conclusions The MDCK-G1 cell line could be used as a substrate to produce H5N1 influenza virus vaccine.

Seat lumbar rotation technique is a commonly used technique,and the clinician is also a kind of clinical curative effect more apparent bone-setting reduction technique.However,the power of spinning technique,direction and position selection is based on the personal experience of the clinician,the lack of a unified,standardized scientific basis for support.Now the article reviews the studies of the rotation of the seat,including lumbar anatomy,biomechanical characteristics,clicks,mechanism of action,and safety.It will provide new ideas for standardizing operations research techniques.

OBJECTIVETo understand the prevalence of myopia in primary and middle school students in 6 provinces and the possible influencing factors.

METHODSPrimary and middle school students were selected through multistage cluster sampling in 60 primary and middle schools in 6 provinces in China. The questionnaire survey and eyesight test were conducted among all the students selected according to the national student's physique and health survey protocol. Pearson chi-square test and binary multivariate logistic regression analysis were done to identify the influencing factors for myopia in students.

RESULTSThe prevalence of myopia among primary and middle school students surveyed was 55.7%, the gender specific difference was statistically significant (59.7% for girls, 51.9% for boys) (P<0.01). The prevalence of myopia increased with age obviously. The prevalence was 35.8% in age group 6-8 years, 58.9% in age group 10-12 years, 73.4% in age group 13-15 years and 81.2% in age group 16-18 years, the differences were statistically significant (P<0.001). Single factor and multivariate analysis showed that parents' myopia, distance between computer screen and eyes, distance less than 30 cm between eyes and book while reading, distance less than 10 cm between chest and the table edge while studying, distance less than 3 cm between fingers and pen tip, sleep time, average outdoor activity time during last week, school sport activities in the afternoon, the size of television set at home, time spent on watching TV and playing computer were the influencing factors for myopia.

CONCLUSIONSThe prevalence of myopia is till high in primary and middle school students. Myopia is associated with both genetic factors and individual eye health related behaviors.

Adolescent ; Child ; China ; epidemiology ; Female ; Health Behavior ; Health Surveys ; Humans ; Logistic Models ; Male ; Multivariate Analysis ; Myopia ; epidemiology ; Parents ; Prevalence ; Schools ; Sleep ; Students ; Surveys and Questionnaires

Acupuncture Points ; Acupuncture Therapy ; Adult ; Genital Diseases, Male ; therapy ; Humans ; Male ; Middle Aged

For the high cost and mobility issues, a home uterine contraction pressure monitoring system based on Windows CE platform was developed. In this paper, the design of hardware circuit, micro-controller system and LabVIEW program based on Windows CE are discussed. The clinical validation experiment in hospital for this system was made and the experimental results show that this system complies with the trend that current medical equipment is becoming portable, homely and networked. Through real-time monitoring uterine contraction pressure, occurrence of premature birth and abortion can be prevented effectively.
Female ; Humans ; Monitoring, Physiologic ; instrumentation ; Pregnancy ; Uterine Contraction

Objective To study the influence of mediating/moderating effects of health skills on the relations between health knowledge and health behaviors in college students.Methods Stratified cluster random sampling was used among 2 181 students,selected in several colleges in Changsha,Hunan province.EpiData 3.0 was adopted to establish the database.Correlation and regression analyses were performed by SPSS 17.0.Results Positive correlations were seen on:1)Knowledge and skills on health (r=0.592,P＜0.01),2)Knowledge and behaviors on health (r=0.647,P＜0.01),3)Health skills and health behaviors (r=0.629,P＜0.01).The mediating effect of health skills on the relations between health knowledge and health behaviors was significant (34.55％).The interaction effect of "health skill × (times) related knowledge" was significant (β =-0.093,t =-5.212,P=0.000).New variables that were produced by the interaction also reached significant level (△R2=0.006,P=0.000),resulted in increasing the explanation function to health behaviors by 0.6％.Conclusion Health skills could partially mediate the effects and moderate the relationship between health knowledge and health behaviors among college students.

OBJECTIVETo explore the relationship between genetic polymorphisms of 3 single nucleotide polymorphisms (SNPs) in the elastin microfibril interfacer 1 (EMILIN1) gene and essential hypertension.

METHODSA case-control study was conducted in which 201 hypertensive patients and 202 healthy controls in Mongolian population were enrolled, and the genotypes of rs3754734, rs2011616 and rs2304682 loci were analyzed using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and direct sequencing techniques.

RESULTSThere were significant differences in the frequencies of alleles and genotypes for the rs2304682 between the hypertensives and normotensives in the population (P<0.05). The frequency of the G-G haplotype established by rs3754734 and rs2304682 was significantly higher in the hypertensive patients (P<0.05). The frequencies of alleles and genotypes for the rs2304682 also had significant differences between the group with high diastolic blood pressure and normal diasto lic blood pressure (P<0.05).There were no significant differences in the frequencies of alleles and genotypes for the 3 SNPs between the group with high systolic blood pressure and normal systolic blood pressure (P>0.05).

CONCLUSIONThe rs2304682 locus in the EMILIN1 gene, as well as the haplotypes G-G constructed using rs3754734 and rs2304682, may associate with the susceptibility of essential hypertension in the Mongolian population. Also, rs2304682 may associate with the level of the diastolic blood pressure.

Blood Pressure ; genetics ; Case-Control Studies ; Genetic Predisposition to Disease ; Humans ; Hypertension ; genetics ; Membrane Glycoproteins ; genetics ; Middle Aged ; Mongolia ; Polymorphism, Single Nucleotide

0.05). The marks of the group of CBL in case analysis test and clinical skills test are significantly higher than that of the group of stepwise learning (P