BACKGROUND:There are two ways to treat the enamel before bracket bonding: etching and sandblasting, but the few studies focus on the direct use of sandblasting technology on untreated enamel surface.
OBJECTIVE:To observe the damage of etchingversus sandblasting to the enamel surface, and to compare the bonding strength of metal brackets adhesive to isolated teeth with these two kinds of surface treatments.
METHODS:(1) Nine premolar teeth removed for orthodontic treatment were randomized into three groups: sandblasting, acid etching and polishing treatment groups. Surface roughening effects of these three kinds of treatments were observed under scanning electron microscope. (1) Another 40 premolar teeth removed for orthodontic treatment were randomized into two groups: sandblasting and acid etching groups. At 24 hours after bracket bonding, the shear strength was detected using mechanical testing machine, and the adhesive residue index of tooth surface was statisticaly calculated.
RESULTS AND CONCLUSION: (1) Under the scanning electron microscope, polishing treatment had no damage to the enamel surface; but in the other two groups, the enamel surface was damaged to varying degrees, especialy in the sandblasting group. (2) The bonding strength in the sandblasting group was significantly higher than that in the acid etching group (P < 0.05), but there was no difference in the adhesive residue index of tooth surface between the two groups (P > 0.05). These findings indicate that compared with the acid etching technology, the sandblasting technology can increase the bonding strength between the enamel and metal bracket, but it also results in more damage.

AIM: To explore the effect of melatonin (MLT) on the apoptosis of thymocytes and splenocytes in mice induced by ionizing radiation and its mechanism. METHODS: The percentages of apoptotic bodies and the DNA lytic rates of thymocytes and splenocytes in mice in vitro and in vivo were detected with flow cytometry and fluorospectrophotometry, respectively. RESULTS: The apoptosis of mouse thymocytes and splenocytes in vitro increased with significant dose-dependence in 0 5-6 0 Gy X-irradiation. When MLT of 2 mmol?L -1 was added into thymocytes or splenocytes in vitro before irradiation with 0 5-6 0 Gy X-rays, the percentages of apoptotic bodies and the DNA lytic rates all decreased significantly as compared with those in the irradiation group. The percentages of apoptotic bodies in these two kinds of cells were 86 25% and 89 22% of those in the irradiation group, respectively, and the DNA lytic rates were 87 23% and 89 16%, respectively. When MLT was injected into intraperitonium in mice 60 min before whole-body irradiation with 2 Gy X-rays, the percentages of apoptotic bodies and the DNA lytic rates were significantly lower than those in the irradiation group, and near or lower than those in the sham-irradiation group. MLT of 0 1-2 5 mg/kg decreased the lymphocyte apoptosis, but without significant dose-dependence. CONCLUSION: The protective effects of MLT on mouse lymphocytes damaged by irradiation in vivo are obvious than those in vitro. [

Objective To study the activation of alveolar macrophage β (AM) and the expression of co-stimulatory molecule CD40 in transfusion-related acute lung injury (TRALI) model in order to illustrate the pathogenesis of TRALI.Methods Sixty SD rats were randomly (random number) divided into normal control group (n =15) with sham operation using normal saline instead of LPS and plasma,positive control group (n =15) with ALI induced by intravenous infusion of 5 mg/kg lipopolysaccharide (LPS) in equivalent volume of whole blood drawn out),and TRALI group (n =15) treated by intra-peritoneal injection of 2 mg/kg LPS 2 h before the transfusion of human plasma (1 mL whole blood about 10％ of total blood volume drawn out and replaced with 1 mL plasma),LPS control group (n =15) treated by intra-peritoneal injection of 2 mg/kg LPS 2 h before saline infusion in equivalent volume of blood drawn out.The pathologic changes of rat lung tissue were observed by HE staining.The expression of TLR4 was examined by RT-PCR.The activation of NF-κB in AM was measured by electrophoresis mobility shift assay (EMSA).The expression of CD40 mRNA and CD40 molecule were analyzed by Northern blot and flow cytometry respectively.ELISA was performed to detect the concentration of TNF-α,MIP-2 and IL-1 β in broncho-alveolar lavage fluid (BALF).Results Broken alveolar septa,hyperemia,and massive infiltration of inflammatory cells including the neutrophils were observed in lung tissues of TRALI group.The expression of TLR4 gene was detected in activated macrophage phi (AMφ) of TRALI group rats.The activation of NF-κB was increased in TRALI group rats.The expression of CD40 in AMφ was higher in rats of TRALI group than that in rats of control group and LPS control group.The concentration of TNF-αt,MIP-2 and IL-1β were enhanced significantly in BALF of TRALI group rats.Conclusion The activation of AM and up-regulation of costimulatory molecule CD40 induced release of some inflammatory cytokines.It suggested that AM activation may play an important role in the pathogenesis of TRALI.

Objective To evaluate regulatory effects of miRNA-146a on peripheral blood CD4 + T lymphocytes from patients with psoriasis vulgaris, and to investigate the role of miRNA-146a in the pathogenesis of psoriasis vulgaris. Methods Totally, 30 patients with psoriasis vulgaris and 30 healthy human controls were enrolled into this study. Venous blood samples were obtained from these subjects, and CD4 + T lymphocytes were isolated from these samples by using magnetic activated cell sorting (MACS). Real-time quantitative PCR (RT-PCR)was performed to measure the expression of miRNA-146a in peripheral blood CD4+ T lymphocytes, and enzyme-linked immunosorbent assay(ELISA)to determine plasma levels of interferon-γ(IFN-γ)and interleukin 4(IL-4). Some CD4+ T lymphocytes were divided into 3 groups to be transfected with 50 nmol/L negative control miRNA (control group), miRNA-146a mimics(miRNA-146a group)or miRNA-146a inhibitor (miRNA-146a inhibitor group). After 24-hour additional culture, flow cytometry was conducted to determine the number of Th1 and Th2 cells, Western-blot analysis and RT-PCR were performed to measure the protein and mRNA expressions of IFN-γ receptor α (IFN-γRα), T-box expressed in T cells (T-bet)and GATA-binding protein-3 (GATA-3)respectively, and ELISA was carried out to determine the levels of IFN-γ and IL-4 in supernatants of CD4 + T lymphocytes. Results Compared with the healthy control group, the patient group showed significantly increased miRNA-146a expression in peripheral blood CD4 + T lymphocytes (243.81% ± 94.32% vs. 105.74% ± 22.93%, t = 6.653, P < 0.01)and plasma IFN-γ level (27.69 ± 7.64 ng/L vs. 9.75 ± 2.81 ng/L, t = 4.237, P <0.01). Moreover, miRNA-146a expression was positively correlated with plasma IFN-γ level in the patients(r = 0.837, P <0.01). After 24-hour culture in vitro, there was a significant increase in the number of Th1 cells, protein and mRNA expressions of T-bet, and supernatant level of IFN-γ, but a significant decrease in the protein expression of IFN-γRα in the miRNA-146a group compared with the control group (all P < 0.01). However, no significant differences were observed in the number of Th2 cells, mRNA or protein expressions of GATA-3, or supernatant level of IL-4 among the control group,miRNA-146a group and miRNA-146a inhibitor group (all P > 0.05). Conclusion miRNA-146a may play an important role in the pathogenesis of psoriasis vulgaris by participating in the regulation of peripheral blood CD4+ T lymphocytes via affecting Th1 cell differentiation and function.

Objective To clarify the pathogen for rubella in Beijing from 2007 to 2010. Methods Beijing Center for Disease Preventipn and Control ( CDC ) collected the specimens (including blood, urine and throat swab specimens) frqm clinically diagnosed rubella cases for serological test and virus isolation. The nucleic acid of rubella virus in clinical specimens and isolations was detected by real-time PCR. Results Fifty-five out of 99 blood specimens were positive for anti- rubella IgM. Fifty-one out of 99 clinically diagnosed rubella cases were confirmed as rubella cases by virus isolation. Seventy-two were confirmed as rubella virus infections with real-time PCR method for detecting the nucleic acid of rubella virus in clinical specimens. Compared with the sequences of reference strains of rubella virus, all of detected rubella virus belonged the IE gene type. Conclusion This study indicates that IE gene type virus was the predominant endemic rubella virus in Beijing.

OBJECTIVETo study clinical effects of the over-articular external fixator combined with limited internal fixation for the treatment of Pilon fractures caused by high energy.

METHODSFrom September 2003 to April 2011, 36 patients with Pilon fractures caused by high energy were treated with the over-articular external fixator combined with limited internal fixator. There were 25 males and 11 females, ranging in age from 16 to 72 years old,with an average of 38 years old. The diagnoses of all patients were determined by conventional X-ray examination or three-dimensional spiral CT examination. The AOFAS scoring criteria was used to evaluate the therapeutic effects. The patients with comminuted fractures were treated with screw or Kirschner wire fixation without uncovering periost so as to enhance stability between fracture end and bone blocks,followed by the fixation with over-articular external fixators.

RESULTSAll the patients were followed up, and the duration ranged from 4 to 27 months, with an average of 13 months. Thirty-two patients got wound healing at the first stage. And the bone union duration ranged from 2 to 6 months, with a mean of 3 months. According to the AOFAS ankle-hindfoot subjective scoring standard, 13 patients got an excellent result, 20 good and 3 fair, with an score of 88.2 +/- 3.6. Twelve patients had infections at pinhole, 5 patients had pinhole pain. One patient had the fixator broken induced by over loading, who was cured after treatment. There were no complications such as nerve or vascular injuries, or osteomyelitis.

CONCLUSIONThe over-articular external fixation combined with limited internal fixation for the treatment of Pilon fractures caused by high energy is an ideal method, which has such advantages as reliable fixation, simple operation, coincidence with principles of biomechanical fixation, and benefit for fracture healing.

Adolescent ; Adult ; Aged ; Ankle Injuries ; diagnostic imaging ; surgery ; Ankle Joint ; diagnostic imaging ; surgery ; External Fixators ; Female ; Fracture Fixation ; Fracture Fixation, Internal ; Humans ; Internal Fixators ; Male ; Middle Aged ; Radiography ; Treatment Outcome ; Young Adult

Objective To summarize the preliminary experience of endovascular stent-graft exclusion for aortic dissections. Methods From October 2003 to February 2007,121 patients[86 males,37 females,mean age(53.7?13.8)years,range 29～ 72 years]underwent endovascular stent-graft exclusion for aortic dissections,including Stanford B in 114 patients,Stanford A in 4, and traumatic aortic mptore in 3.An emergency operation was performed in 4 patients for acute aortic rapture.Results No primary conversion was needed.There was no postoperative death,no spinal cord iscbemic injury,or stent displacement or subclavian steal syndrome.Postoperative hospital stay time was(4.0?1.3)days.Complications included fever in 35 patients,type Ⅳ endoleak in 11,type Ⅰ endoleak in 1 and acute renal dysfunction in 1.Contusion Endovascular thoracic aorta repair is an effective,less inva- sire and safe surgery for patients with Stanford B or some Stanford A aortic dissection and traumatic aortic rupture.

The effects of pioglitazone (PIO) and tumor necrosis faetor-?(TNF-?) on two kinds of adiponectin receptor (AdipoR) mRNA expression were observed in 3T3-L1 adipocytes by RT-PCR.AdipoR mRNA expression was up-regulated during 3T3-L1 preadipocyte differentiation;PIO could increase the AdipoR mRNA level expressed in undifferentiated and differentiated 3T3-L1 adipocytes in a time-and dose-dependent manner,and TNF-?had no influence on the expression of AdipoR mRNA.

Objective: To assess the health risk associated with drinking water in Hangzhou from 2016 to 2017,and to provide evidence for the safety of drinking water . Methods: The monitoring data of 5 genetic toxic substances（arsenic,hexavalent chromium,cadmium,chloroform,tetrachloromethane）and 13 body toxic substances（lead,mercury,selenium,cyanide,fluoride,nitrate,iron,ammonia nitrogen,manganese,copper,zinc,aluminum,volatile phenol）from 36 source water samples,36 finished water samples and 288 tap water samples in the main urban areas of Hangzhou were collected from 2016 to 2017. The health risk of drinking water containing the chemical pollutants mentioned above were assessed based on the evaluation models recommended by United States Environmental Protection Agency . Results: The concentrations of 5 genetic toxic substances and 13 body toxic substances in source water,finished water and tap water were all within the reference limits issued by Standards for Drinking Water Quality（GB 5749—2006）. The carcinogenic risk,non-carcinogenic risk and total health risk caused by the chemical pollutants in the source water were 2.18×10-5/a,7.75×10-9/a and 2.18×10-5/a. The carcinogenic risk,non-carcinogenic risk and the total health risk caused by the chemical pollutants in the finished water were 1.08×10-5/a,3.70×10-9/a and 1.08×10-5/a. The carcinogenic risk,non-carcinogenic risk and total health risk caused by the chemical pollutants in the tap water were 1.96×10-5/a,3.61×10-9/a and 1.96×10-5/a. The carcinogenic risk and total health risk caused by chemical pollutants ranged from high to low in the source water,tap water and finished water. The non-carcinogenic risks ranged from high to low in the source water,finished water and tap water . Conclusion The health risks of 18 chemical pollutants in drinking water in Hangzhou were at a low level,with the greater carcinogenic risk than the non-carcinogenic risk. Hexavalent chromium had the highest carcinogenic risk,while fluoride and aluminum had the highest non-carcinogenic risk.

Objective To compare maternal and neonatal outcomes after induction,elective cesarean section and spontaneous onset of labor in uncomplicated term nulliparous women.Methods A total of 3751 uncomplicated term nullipara who delivered in Peking Union Medical College Hospital from Sept 2002 to April 2007 were retrospectively analyzed.They were divided into three groups:the induction group, the elective cesarean section group,and the spontaneous onset of labor group.Their general conditions (such as age,weeks of pregnancy,hospital days and cost),postpartum complications(such as postpartum hemorrhage,puerperal morbidity,urinary retention,blood transfusion,delayed healing,and trauma),and Apgar score were compared by statistic methods.Results(1)Among 3751 women,501(13.3%)of them underwent induction(the induction group),1634(43.6%)delivered by cesarean section(cesarean section group),the other 1616(43.1%)women underwent spontaneous onset of labor(the spontaneous onset of labor group).(2)Results of general conditions:the spontaneous onset of labor group had the shortest hospital days,which was longer in the induction group,and the longest in the selective cesarean section group(P