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 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.

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.

Chromosomal integration enables stable phenotype and therefore has become an important strategy for breeding of industrial Saccharomyces cerevisiae strains. pAUR135 is a plasmid that enables recycling use of antibiotic selection marker, and once attached with designated homologous sequences, integration vector for stable expression can be constructed. Development of S. cerevisiae strains by metabolic engineering normally demands overexpression of multiple genes, and employing pAUR135 plasmid, it is possible to construct S. cerevisiae strains by combinational integration of multiple genes in multiple sites, which results in different ratios of expressions of these genes. Xylose utilization pathway was taken as an example, with three pAUR135-based plasmids carrying three xylose assimilation genes constructed in this study. The three genes were sequentially integrated on the chromosome of S. cerevisiae by combinational integration. Xylose utilization rate was improved 24.4%-35.5% in the combinational integration strain comparing with that of the control strain with all the three genes integrated in one location. Strain improvement achieved by combinational integration is a novel method to manipulate multiple genes for genetic engineering of S. cerevisiae, and the recombinant strains are free of foreign sequences and selection markers. In addition, stable phenotype can be maintained, which is important for breeding of industrial strains. Therefore, combinational integration employing pAUR135 is a novel method for metabolic engineering of industrial S. cerevisiae strains.
Genetic Engineering ; methods ; Genetic Vectors ; Metabolic Engineering ; Plasmids ; genetics ; Saccharomyces cerevisiae ; genetics ; Xylose ; metabolism

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 study the life style and the status of nutrition knowledge for the children of Pinggu district of Beijing,and to provide evidences for targeted education and guidance.Method Using cluster sampling method,15 118 pupils aged 7-13 yeas in Pinggu district of Beijing were investigated for their nutrition knowledge,sports and diet habits using the questionnaire investigation method.The children at grades 1-3 were defined as the junior group,those at grades 4-6 were defined as the senior group,all pupils were divided into urban and rural groups according to the distance to pinggu district town center.The Excel 2003 was used for databases.The status was analysed using SPSS13.0 statistical software.Chi-square test wcs used for comparing categorical data.Result Totally 13 192 questionnaires were returned,accouting for 87.26％; 11 364 of them were valid,accouting for 75.17％.The awareness rates about the fruits and vegetables which are rich in nutrients,the food rich in calcium,the food rich in protein,nutrient deficiency anemia was relatively low,they were respectively 58.33％,62.72％,58.83％,43.18％; the awareness rates on the relationship between diet and health,effects of obesity on the health,excessive dringking is harmful and eating more salt was harmful,were relatively high:88.82％,92.33％,94.27％,and 83.74％,the differences between gender,grade,area and students' awareness of the comparison,were statistically significant (P＜0.05).The awareness rate of the question about what is dietary pyramid was 18.77％,the differences between different gender and grade were statistically significant (P＜ 0.01).The questionnaire of eating habits:the students who do not or occasionally have breakfast accounted for 14.84％; the rate of three meals which were irregular accounted for 14.46％; children who do not like to eat grains,vegetables and fruit,respectively accounted for 18.59％,21.61％,4.23％; the number of children who do not like to drink milk and eat soy products was high,the proportion was 38.52％ and 60.17％.At the same time the differences in time between sex,grade,areas,were statistically significant (P＜0.05).The questionnaire about movement and sleeping habits:the students who like walking,playing,climbing and other way to relax after class accouted for 59.94％,the exercise time was 30 minutes or more accounted for 40.99％,51.14％; students who ride bike or walk to school,children who ensure 9-10 hours for sleeping every day accounted for 84.86％,differences between different sex,area and grade were statistically significant (P＜0.01).Conclusion The children in this district generally had lack of the nutrition knowledge.There were many bad diet habits,while sport habits were also poor.In order to improve diet and sport habits of rural school children,we should do targeted nutrition and health education to children.

Objective To observe the effects ofJingui Shenqi Pills on the expressions of TGF-β1, CYP19, sex hormone level and sperm quality;To discuss its mechanism for the treatment of male sterility.Methods Forty adult male SD rats were randomly divided into normal group, model group, retardant group andJingui Shenqi Pills group, 10 rats in each group. Except for the normal group, adenine was used to induce healthy rats to kidney yang deficiency and sterility model rats. Normal group was given normal saline for gavage;retardant group was injected with testicular mesenchyme TGF-β1;Jingui Shenqi Pills group was givenJingui Shenqi Decoction for gavage. Blood was taken through caudal vein. Immunohistochemical, radioimmunoassay and electron microscopy observation were used to detect the expressions of TGF-β1, CYP19, sex hormone level, sperm density and motility rate and testicular morphological changes.Results Compared with normal group, the expression of TGF-β1 in the model group increased and CYP19 decreased (P<0.05). Compared with model group, the expression of TGF-β1 decreased and the expression of CYP19 increased (P<0.05). Compared with normal group, the number of sperm quantity was small and paramorphia in model group (P<0.05). Compared with model group, T, E2, sperm density and motility rate increased significantly inJingui Shenqi Pills group and retardant group (P<0.05). There was no statistical significance among indexes in retardant group andJingui Shenqi Pills group.ConclusionJingui Shenqi Pills can improve sperm quality and sex hormone level of model rats with kidney-yang-deficiency, which mechanism is probably realized by inhibiting the expression of TGF-β1R and promoting the expression of CYP19 in testis to effect development and proliferation of sperm.

BACKGROUND:To in vitro isolate neural stem cel s with high purity and uniform biological properties and to establish a complete set of neural stem cel culture system is the basis for neural stem cel research.
OBJECTIVE:To establish an isolation and culture system for neural stem cel s from newborn mouse hippocampus, olfactory bulb and cortex and to analyze the biological properties of cel s.
METHODS:Neural stem cel s were isolated from the hippocampus, olfactory bulb and cortex tissue of newborn Kunming mice by mechanical separation and trypsin digestion. Serum-free culture technology, mechanical pipetting and trypsin digestion were used for subculture of neural stem cel s. 10%fetal bovine serum was used to induce differentiation of neural stem cel s. Neural stem cel s and their differentiated products were identified by
immunofluorescent staining of Nestin, CD133,β-TubulinIII, glial fibril ary acidic protein.
RESULTS AND CONCLUSION:The neural stem cel obtained from newborn mouse hippocampus, olfactory bulb and cortex had the capacity of self-renewal and differentiation which were positive for Nestin and CD133. After induction with fetal bovine serum, neural stem cel could differentiation toβ-tubulinIII or glial fibril ary acidic protein positive cel s that were neurons and astrocytes. This experiment has successful y established the neural stem cel isolation, culture, identification and induction system, providing experimental basis for subsequent studies of neural stem cel s.

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.