Objective To investigate hepatitis B virus mutation rate after the universal immunization in China. Methods DNA sequence analysis of the “a” determinant was performed on sera from 72 viral carrier children after immunoprophylaxis selected through a sampling survery. Results Four mutants were detected, the mutation rate was 5.56%. One strain showed Gly-to-Arg mutation at the 145 codon of surface antigen. Animo acid substitutions at the amino acid 126 and 140 were noted in the other three children. The epidemiological HBV serotype shifted from previous adw infection to more recent adr was also observed. Conclusions These observations indicate that vaccination is probably the cause of mutation, whereas the mutation is low and it will certainly not be a reason for doubting that the vaccination is the method of main choice for preventing hepatitis B infection that still devastates the developing countries.

Objective:To optimize the macroporous resin separation process for total flavonoids in papaya. Methods:The content of total flavonoids in papaya was selected as the index, and the resin model, sample solution concentration, ratio of diameter and height, the flow rate of adsorption, type and volume of eluent, type and volume of impurity removing solvent, elution velocity and the other parameters were investigated. Results:The optimal purification process was as follows: the macroporous resin type was D-140, the sample solution concentration was 0. 1 g·ml-1 , the sample volume was 2BV, the ratio of diameter and height was 1∶9, washing the impurities with 3BV water, eluting with 3BV 10% ethanol first followed by 3BV 50% ethanol with 2BV·h-1 , and collecting 50%ethanol elution. The total flavonoids content was 52%. Conclusion:The optimized process can separate and purify the total flavonoids in papaya effectively.

Objective:To explore the association of physical activities,sedentary behaviors with over-weight/obesity in Chinese children aged 9 -1 1 years,analyze the gender difference and heterogeneity of the association across different provinces,and provide evidence for prevention and control of overweight and obesity.Methods:Using the data of 40 692 children aged 9 -1 1 years from Chinese National Survey on Students’Constitution and Health in 201 0,the height and weight were measured and the time spent in physical activities,screen behaviors and homework were collected.We analyzed the associations among physical activities,sedentary behaviors and overweight/obesity in boys and girls separately,and assessed the heterogeneity of associations across different provinces with Meta-analysis.Results:The prevalence of overweight/obesity of the boys (27.1 %)was higher than that of the girls (1 2.9%),compared with the rural students (1 5.6%),the situation of overweight/obesity of the urban students (23.8%)was more serious,the prevalences of overweight/obesity were separately 22.6%,1 9.2% and 1 7.5% among developed,middle-developed and undeveloped social economic status subgroups.The boys with physical activities no more than 1 hour per day were more likely to be overweight/obese,with the OR of 1 .09 (95%CI:1 .02,1 .1 7).The girls with screen time more than 1 hour per day or homework time more than 2 hours per day were more likely to be overweight/obese,with the ORs of 1 .1 3 (95%CI:1 .02, 1 .26)and 1 .1 8 (95%CI:1 .03,1 .35)respectively.The high level of sedentary behaviors (more than 1 35min per day)was associated with overweight/obese in the girls,and the OR was 1 .1 9 (95%CI:1 .08,1 .33).There was no significant heterogeneity of effect values between physical activities and over-weight/obesity in the boys and between sedentary behaviors and overweight/obesity in the girls across the different provinces (P >0.05).Conclusion:The associations among physical activities,sedentary be-haviors and overweight/obesity existed in Chinese children aged 9 -1 1 years,which were different in boys and girls.There was no statistically significant heterogeneity across different provinces.The strate-gies to prevent and control overweight/obesity in primary school students should focus on gender-specific needs.

BACKGROUND:It has been recently indicated that nervous factors are able to adjust and dominate bone fracture healing. Type Ⅰ collagen is a major factor to promote the differentiation of osteoblasts and enhance the adhesion of osteoblasts; while, it is also a matrix protein for composing bone framework. Type Ⅱ collagen is derived from chondrocytes. OBJECTIVE: To study changing law of type Ⅰ and Ⅱ collagen expression during denervated bone fracture healing. DESIGN, TIME AND SETTING: Randomized controlled anima study was performed at the Animal Laboratory and Cell Biology Laboratory, the Second Military Medical University of Chinese PLA between May and December 2005. MATERIALS: Forty 3-month-year healthy male SD rats were randomly divided into fracture group (tibial fracture alone) and combination group (spinal cord injury combined with tibial fracture), with 20 rats at each group. METHODS: A φ 0.8 mm Kirschner wire was inserted into anterior border of left tibial plateau to establish tibial fracture models in the fracture group. A 0.3-cm spinal cord transection was cut at T10 segment to establish tibial fracture models with entire spinal cord injury. MAIN OUTCOME MEASRUES: Type Ⅰ and Ⅱ collagen protein expressions of callus were detected using Western blot technique in week 1, 2, 4, and 5 post-injury. RESULTS: One week after injury, type Ⅰ and Ⅱ collagen was represented in callus in the two groups, while the expressions in the combination group were significantly higher than fracture group (P<0.05); two weeks after injury, type Ⅱ collagen expression reached at the peak in the combination group, and the expression was significantly higher than the fracture group (P<0.05); four weeks after injury, type Ⅰ collagen expression reached at the peak in the fracture group, and the expression was significantly higher than the combination group (P<0.05), while type Ⅱ collagen still highly expressed in the combination group; five weeks after injury, type Ⅰ and Ⅱ collagen expressions were decreased in the two groups. CONCLUSION: Secretory law of type Ⅰ and Ⅱ collagen during denervated bone fracture healing is similar to normal bone fracture healing; however, the differences at time points, in particular expression at peak, are remarkable between them.

According to the recommended diagnostic criteria of obese adults in Asia-Pacific region,8 284 cases of middle-aged and elderly people in Uygur and Han populations were collected randomly to study the status and distribution characteristics of two nationalities.Standardized prevalences of obesity were 20.1 2%in Uygurs and 23.077%in Hans.Woman in Hans reached the highest prevalence.Alcohol-drinking,abnormal giycometabolism,and serum cholesterol levels were the most relevant risk factors.

Objective To explore a new method for one-stage repair of the intestinal leakage based on the principle of magnetic compression anastomosis. Methods Twenty-four dogs were randomly divided into experimental group (n = 12) and control group (n = 12) according to random number table. The model of upper and multiple intestinal leakages was established by making transverse incisions of 1 cm in length on the jejunum wall about 50 cm and 100 cm away from the Treitz ligament. Forty-eight hours later, two NdFeB magnetic rings with the magnetic flux of 2500 G were put into the intestine from the leak sites. The leak sites were pressed between the two rings. The ventages in the control group were sutured. The condition of the dogs was observed after the repair of the leakage. The excreting time was recorded, and the leakage pressures of the anastomotic stoma were detected.The positions of the magnetic rings in the experimental group were detected by X ray. Tissues of the anastomotic stoma were processed by hematoxylin eosin and Masson staining. All data were analyzed using the two-sample t test. Results Severe abdominal infection occurred 48 hours after the establishment of the model. All the intestinal leakages in the experimental group were successfully repaired and the dogs survived for a long time. The magnetic rings were excreted six or seven days after the repair. Eight dogs of the control group survived. The leakage pressure of the anastomotic stoma seven days after the repair was (134 ±23)mm Hg (1 mm Hg =0. 133 kPa) in the experimental group and (91 ± 18)mm Hg in the control group, respectively, with a significant difference between the two groups (t = 3.225, P ＜ 0.05). The leakage pressure of the anastomotic stoma 14 days after the repair was (281 ±7)mm Hg in the experimental group and (271 ±21) mm Hg in the control group, respectively, with no significant difference between the two groups (t =0. 988, P ＞ 0.05). Histological observation showed that after the magnetic compression anastomosis, the intestinal muscle and mucosa recovered well, inflammatory reaction was slight and less collagen fiber and scar was formed. Conclusions Application of magnetic ring with the magnetic flux of 2500 G in one-stage repair of the intestinal leakage in the state of severe abdominal infection is safe and reliable.

Objective:To analyze the awareness rate of obesity risk factors among children and adoles-cents, and to provide the basis for preventing their obesity. Methods: The students selected by using stratified cluster sampling method, were measured for the body height, weight, and waist circumference, and were surveyed for the awareness rate of obesity risk factors by using the questionnaire. The distribu-tion characteristics of awareness on obesity risk factors were analyzed. Results: The awareness rate of obesity risk factors was 74 . 1%, and there was no significant difference on the awareness rate of obesity risk factors between the males [71. 2% (247/347)] and females [77. 2% (257/333)], the abdominal obesity students [73. 5% (202/275)] and non-abdominal obesity students [74. 6% (302/405)], the overall obesity students [74. 3% (185/249)] and non-overall obesity students [74. 0% (319/431)], re-spectively. However, the awareness rate of obesity risk factors among the primary school students was 81. 9% (272/332) that was higher than that of the middle school students [66. 7% (232/348)] (P<0. 05). Compared with the primary school students, the non-awareness risk of obesity risk factors would in-crease among the middle school students (OR=2. 23, P<0. 05). Conclusion:The overall awareness rate of obesity risk factors is not high among children and adolescents, especially among middle school students.

Objective To investigate the effects of alpha lipoic acid on patients with diabetic retinopathy (DR),explore the possible mechanisms,and provide experimental evidence for the treatment of DR with lipoic acid.Methods Totally 75 DR patients were randomly divided into control group and treatment group.Patients in control group received the standard hypoglycemic treatment,antihypertensive therapy,and other comprehensive treatment.Patients from the treatment group were treated with alpha lipoic acid 600 mg + 250 ml 0.9％ sodium chloride injection additionally,avoiding light intravenous therapy,for a total of 4 weeks.Before and after treatment,fundus fluorescein angiography and visual inspection were detected in two groups.In addition,serum level of asymmetric dimethylarginine (ADMA) were detected with high performance liquid chromatography,serum lipid peroxidation product malondialdehyde (MDA) content and superoxide dismutase (SOD) activity were detected to reflect the in vivo oxidative stress before and after treatment in two groups.Results Compared to the control group,visual acuity was improved significantly (P ＜ 0.05),and total efficiency of ocular lesions-improved was increased significantly (84.21％ vs 40.54％,x2 =15.28,P ＜ 0.01).Serum levels of endogenous inhibitor of nitric oxide synthase ADMA [(0.32 ±0.13) μmol/L vs (0.51 ± 0.26) μmol/L,P ＜ 0.05] and MDA [(3.22 ± 0.90) nmol/L vs (5.13 ± 0.42) nmol/ml,P ＜ 0.05] were significantly decreased,while SOD levels [(72.68 ± 1.31) U/ml vs (53.16 ± 1.54) U/ml,P ＜0.05] were significantly increased in DR patients after alpha lipoic acid treatment.Conclusions Alpha lipoic acid had some therapeutic effects for DR patients,which mainly lied in the improvement of visual acuity and eye disease,might be related to the decrease of oxidative stress and serum level of endogenous nitric oxide synthase (NOS) inhibitor ADMA.

Objective:To study the relationship between rs 2228314 polymorphism in sterol regulatory element binding protein 2 gene (SREBP2) and obesity, serum lipid levels in children and adolescents . Methods:In our study , 2 030 children and adolescents aged from 7 to 18 years participated .Anthropo-metric measurements, including height and weight, were performed.Their serum total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol ( HDL-C) were detected .The matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS ) was used to detect rs2228314 genotypes.Results: The GC/CC genotypes of rs2228314 polymorphisms had lower HDL-C levels than GG genotype [(0.10 ±0.35) mmol/L vs. (0.14 ±0.36) mmol/L, P=0.020].The rs2228314 polymorphism was associated with the abnormal HDL-C level under the dominant model after adjustment for study samples , sex and age ( OR=1.400, 95%CI:1.027-1.907, P=0.033).The rs2228314 polymorphism was not associated with obesity un-der the dominant model after adjustment for study samples , sex, age and HDL-C level ( OR=1.178, 95%CI: 0 .971 -1 .430 , P =0 .096 ) . Conclusion: The GC/CC genotype carriers of SREBP2 rs2228314 polymorphism have higher risk of abnormal HDL-C level than the individuals with GG geno-type among children and adolescents .

In educating postgraduate students in aerospace medicine in our country, there are some deficiencies such as the course content lacking forward looking and systematicness, and students' mastery of technology or skills lacking professional characteristics, innovation and divergent thinking. Based on the original foundations, the School of Aerospace Medicine, Fourth Military Medical University, has been con-structing and improving the course system by modifying the course contents, reforming the practical teach-ings, expanding the academic communications, and managing the processes. Finally, they have achieved certain results.