Objective To identify the effect of health risk behaviors on accidental injury of adoles-cents.Then analyze the strength and approach of the health risk behaviors. Methods Cluster sampling on various stages and strata methods was adopted. The adolescents from grade one to three in junior school students and grade one to three in senior high school students completed the questionaire. A total of 4408 students were surveyed and 4309 samples were valid. Path analysis was used to understand how factors could influence injury incidence. Results The incidence of adolescent injury was 15.53%. Statistical differences were found between genders (male 17.77%,female 13.36%,χ2=15.91, P<0.01),education levels (junior high school 17.36%,senior high school 13.99%,χ2=11.45, P<0.01) and cities ( Beijing 12.97%,Zhongs-han 17.95%,χ2=20.33, P<0.01) . Those who got injured were found with more health risk behaviors. Health risk behavior was the direct influencing factor to injury,as well as a possible risk factor to multiple injuries. Conclusion Health risk behaviors can strongly affect adolescent injury,and can be an indicator. Reducing health risk behaviors is important in adolescent injury prevention.

BACKGROUND:Our previous studies have shown that a soft substrate has a significant effect on morphology and cytoskeleton of rat bone marrow mesenchymal stem cel.
OBJECTIVE:To explore the effect of polyacrylamide gels as soft substrates with different elastic moduli on the chondrogenic differentiation of human synovial-derived mesenchymal stem cels.
METHODS:The synovium was harvested from patients with osteoarthritis under sterile conditions, and primary human synovial-derived mesenchymal stem cels were separated using limiting dilution assay. The flow cytometry and multi-directional differentiation experiments were used to identify the cel surface markers and function of the human synovial-derived mesenchymal stem cels, respectively. The polyacrylamide gels with the elastic modulus of 0.4, 6, 30 kPa, which were made using various amounts of acrylamide and bis-acrylamide, were used to culture human synovial-derived mesenchymal stem cels under induction with transforming growth factor-β1 for 7 and 14 days. RT-PCR was used to test the expression of chondrogenic genes, type II colagen gene and cartilage acidic protein 1. The 6-wel cel culture plates served as controls.
RESULTS AND CONCLUSION: The human synovial-derived mesenchymal stem cels showed different cel morphology in the different elastic modulus of polyacrylamide gels. The expression of type II colagen gene and cartilage acidic protein 1 were affected by the different elastic modulus of polyacrylamide gels and culture time, and there was an interaction between these two factors. At 7 days of induction, the expression of cartilage acidic protein 1 gene on 6 kPa polyacrylamide gels was the highest (F=44.350,P=0.000); meanwhile, the expression of type II colagen gene on 0.4 kPa polyacrylamide gels was the highest (F=6.384,P=0.005). These findings indicate that polyacrylamide gels with lower elastic modulus are superior to routine culture plates to promote the chondrogenic differentiation of human synovial-derived mesenchymal stem cels.

Veratridine, a blocker of inactive gate of sodium channel, was used to perfuse L5 dorsal root ganglion (DRG) topically. Afferent activities of type A single fiber from these DRGs were recorded. It was found that after a 10-min bath of veratridine (1.8-3 micromol/L), some of the primary silent DRG neurons were triggered by touch or pressure on the receptive fields or by electrical stimulation of the sciatic nerve to produce high-frequency firing, which was termed triggered oscillation presenting a U-type of interspike intervals (ISI) or other types of oscillations. The longer the intervals between stimulating pulses, the more stimulating pulses were needed to trigger the oscillation. The oscillation, triggered by electric stimuli with different duration or patterns, had no significant difference in their patterns. The duration of the inhibitory period after a triggered oscillation was generally 30-90 s. It was also observed that this kind of triggered oscillation was induced by afferent pulses of the same neurons. These results suggest that triggered oscillation, which may contribute to the fit of triggered pain, can be produced in primary sensory neurons after application of veratridine.
Action Potentials ; physiology ; Animals ; Female ; Ganglia, Spinal ; cytology ; drug effects ; Male ; Neurons, Afferent ; physiology ; Rats ; Rats, Sprague-Dawley ; Sodium Channel Blockers ; pharmacology ; Veratridine ; pharmacology

OBJECTIVETo evaluate the antibacterial efficacy of KaVo KEY laser on Enterococcus faecalis (E. faecalis) within infected root canals and roots surface in vitro.

METHODSFifty single-rooted teeth were selected, and infected root canals and roots surface vitro models were prepared. Then, these specimens were divided into three groups. First group were untreated as blank control. The other two groups were the laser groups: Irradiated 15 s and 30 s respectively with 80 mJ and 140 mJ in root canals and on roots surface. Microbiological samples were collected from root canals and roots surface at two time points (before irrigation and immediately after irrigation). The dentin chips from three different zone of part of root canals in each group were immediately collected and were cultured for 24 h in brain heart infusion (BHI).

RESULTSThe number of E. faecalis in root canal and root surface in each of the groups were effectively reduced (P < 0.05), and there was no significant difference between each two groups (P > 0.05). Compared with the blank control, the bacterial number in 100 microm of dental tubules decreased after specimens treated with 80 mJ, and the experimental group irradiated 15 s was a significant decease (P < 0.05). The other groups were no changed in different zone of dental tubules.

CONCLUSIONKaVo KEY laser is effective on sterilizing infected root canals and roots surface. It has also significant effect on bacterial in superficial dental tubules with low energy and short time.

Dental Pulp Cavity ; microbiology ; Enterococcus faecalis ; radiation effects ; Humans ; Lasers

OBJECTIVEPosterolateral intertransverse process fusion was performed in aged and young adult female rabbits lumbar spine using recombinant human bone morphogenetic protein-2 (rhBMP-2) and autograft to reveal the function of rhBMP-2 on spinal fusion on aged animals.

METHODSA total of 24 female New Zealand white rabbits included 12 young adult of 6 months and 12 aged of 2-year-old, was divided into 4 groups: (1) young adult autologous iliac crest bone group [ICBG(Y), n=6); (2) young adult rhBMP-2/absorbable collagen sponge (ACS) group [BMP-2(Y), n=6]; (3) aged autologous iliac crest bone group [ICBG(O), n=6]; aged rhBMP-2/ACS group [BMP-2(O), n=6]. All were underwent posterolateral fusion in same day. rhBMP-2 and autologous iliac crest bone was implant bilateral LS-L6 intertransverse processes, respectively. Half of the rabbits were sacrificed at 3.6 weeks following surgery, respectively. The results were assessed by manual palpation, radiographs, computed tomographic scans (3D) and histology.

RESULTSSix weeks after surgery, radiography, computed tomography and histology indicated the different result in healing in the posterolateral fusion using rhBMP-2 compared to ICBG (P < 0.05). Aged BMP-2 group showed significantly higher fusion rates than Aged ICBG group.

CONCLUSIONThis study demonstrated rhBMP-2 can increase the posterolateral fusion rate and new bone quality in aged rabbitss than autograft, it may take the place of ICBG. But its role is effected by age.

Aging ; Animals ; Bone Morphogenetic Protein 2 ; pharmacology ; Female ; Humans ; Palpation ; Rabbits ; Recombinant Proteins ; pharmacology ; Spinal Cord ; drug effects ; pathology ; surgery ; transplantation ; Spinal Fusion ; Tomography, X-Ray Computed ; Transplantation, Autologous

OBJECTIVETo detect potential mutations for probands from families affected with Duchenne/Becker muscular dystrophy (DMD/BMD), and to carry out prenatal diagnosis through identification of female carriers.

METHODSA total of 43 DMD/BMD families were recruited. Multiplex PCR was used to analyze 18 exons within hotspots for DMD gene deletions. Multiplex ligation-dependent probe amplification (MLPA) was used to detect potential deletions and duplications of DMD gene for 43 patients and 36 females from 32 families. Prenatal diagnosis was performed for 27 families.

RESULTSDeletional mutations were detected in 26 patients with multiplex PCR. In addition, MLPA has detected 3 deletions and 6 duplicational mutations, and the ranges of mutations were all determined. Among 36 female members, 18 were determined as carriers of deletional mutations, 10 were excluded as mutation carriers. The status of remaining 8 could not be determined. For prenatal diagnosis, 3 out of 18 male fetuses were diagnosed as patients and 1 female fetus was identified as carrier.

CONCLUSIONMLPA is an accurate and reliable method for detecting deletional/duplicational mutations of DMD gene as well as for prenatal diagnosis and detection of female carriers.

Adolescent ; Child ; Child, Preschool ; Dystrophin ; genetics ; Female ; Heterozygote ; Humans ; Infant ; Male ; Multiplex Polymerase Chain Reaction ; Muscular Dystrophy, Duchenne ; diagnosis ; genetics ; Mutation ; Pedigree ; Pregnancy ; Prenatal Diagnosis

OBJECTIVETo detect the self-assembly morphology of sodium hyaluronate injection on mica using atomic force microscopy(AFM).

METHODSAtomic force microscopy with nanometer resolution was used to observe the self-assembly morphology of different concentrations of sodium hyaluronate injection on mica at room temperature.

RESULTSThe self-assembly morphology of 0.001, 0.01, and 0.1 mg/ml sodium hyaluronate injection on mica featured piebald, reticular and dendritic structures, respectively. At 1 and 5 mg/ml, sodium hyaluronate injection displayed bacilliform and spherical structures on mica, respectively; the diameter and height of the particles of 5 mg/ml sodium hyaluronate was 197.97±78.48 nm and 30.79±18.67 nm, significantly greater than those of 0.1 mg/ml sodium hyaluronate injection (49.52±11.93 nm and 5.37±1.59 nm, respectively, P<0.05).

CONCLUSIONThe self-assembly morphology of sodium hyaluronate injection on mica varies with its concentration. The piebald and reticular structure may facilitate the function of sodium hyaluronate, and the dendritic feature resembles the representative model of diffusion-limited aggregation (DLA).

Aluminum Silicates ; chemistry ; Hyaluronic Acid ; administration & dosage ; chemical synthesis ; chemistry ; Microscopy, Atomic Force ; Nanostructures ; Surface Properties

BACKGROUNDPreoperative tumor grading becomes one of the most important predictors for lymphadenectomy at primary surgery for clinical stage I endometriod adenocarcinoma. However, there is an inconsistency of tumor grade between preoperative curettage and final hysterectomy specimens, and its associated factors are poorly understood. This study aimed to evaluate the accuracy of tumor grade by preoperative curettage so as to achieve a better stratified management for clinical stage I endometriod adenocarcinoma.

METHODSClinical data of totally 687 patients with clinical stage I endometriod adenocarcinoma who underwent preoperative curettage and primary surgery were retrospectively collected. Compared with final hysterectomy specimens, the sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of tumor grade by preoperative curettage were calculated and their associations with clinicopathologic parameters, including age, status of menopause, position of uterus, location and size of lesion, histological grade, depth of myometrial invasion, cervical invasion, extrauterine spread, peritoneal cytology, metastasis to retroperitoneal lymph node, serum CA125 level, and hormone receptor status, were analyzed.

RESULTSIn final hysterectomy specimens, 139 of 259 grade 1 patients by curettage were upgraded to grade 1 or 2; 31 of 296 grade 2 were upgraded to grade 3, with a significantly discrepant rate of 40.9% (281/687) and an upgraded rate of 24.7% (170/687). The specificity and negative predictive value for grade 3 were 90.7% and 89.9%, while the sensitivity and positive predictive value for grade 1 were 67.1% and 40.9%, respectively.

CONCLUSIONSPreoperative tumor grade by curettage does not accurately predict final histological results, especially in those classified as grade 1. Complete surgical staging seems to be necessary for clinical stage I endometriod adenocarcinoma.

Adenocarcinoma ; diagnosis ; pathology ; surgery ; Adult ; Curettage ; methods ; Endometrial Neoplasms ; diagnosis ; pathology ; surgery ; Female ; Humans ; Hysterectomy ; Middle Aged ; Neoplasm Staging ; methods ; Retrospective Studies

Six gene segments,PB1,PB2,PA,NP,M and NS,were fully synthesized which derived from the master donor virus (MDV),cold-adapted(ca),temperature sensitive(ts),live attenuated influenza virus strain A/Ann Arbor/6/60(MDV-A).Meanwhile,five amino acid substitutions (PB1-391E,58lG,661T,PB2-265S,NP-34G) were artificially altered by human intervention.HA and NA fragments derived from the 2006-2007 circulating strain A/New Caledonia/20/99 (H1N1).Eight fragments were ligated with modified pAD3000 for rescue plasmid construction.Eiight transcription/expression plasmids were named as pMDV-A-PB2,pMDV-A-PB1,pMDV-A-PA,pMDV-A-NP,pMDV-A-M,pMDV-A-NS,pMDV-A-HA,pMDV-A-NA,respectively.The COS-l cells were co-transfected with eight plasmids representing 6 internal viral backbone of the strain A/AA/6/60 and two plasmids containing the CDNA of the HA and NA segments of the strain A/New Caledonia/20/99 (H1N1),the results showed that cold-adapted,attenuated reassortant influenza A virus Was rescued successfully.Titers of a reassorted influenza A virus in embryonated chicken eggs mnged from 1:29to l:210.The rescue system of six intemal genes used as backbone opens the way for further research on gene function and neotype vaccine candidate of cold-adapted,live attenuated human influenza virus.

Objective: To explore the related factors and working way of adolescent injury,and to provide a basis for the effective prevention and intervention of adolescent injury. Methods: The framework of the questionnaire in this study was developed based on the Social Ecology Model. A cross-sectional survey was conducted on a valid sample of 4 309 students from 8 junior high schools and 8 senior high schools in Beijing and Zhongshan city respectively, using stratified random cluster sampling method. Students from grade 7 to grade 12 were invited to participate and investigated with injury prevalence. Results: The incidence of adolescent injury by person and by person-time was 15.53% and 22.49% respectively, and there were differences by sex, age and regions(χ2=15.92，11.45，20.33，P<0.05). The occurrence of adolescent injury was affected by adolescent psychological behavior and social environment through different underlying pathways. The intrapersonal factors and perception of environmental safety showed direct effects on the adolescents’ injuries (effect size was 0.29 and 0.05 respectively, P<0.05). Conclusion Adolescent injury is associated with diverse factors and pathways in a synergistic and complex manner, suggesting that a three-dimensional and diverse strategy should be taken to intervene the injures.