Objective: To observe the effect of purified high rela ti ve molecular mass mucin(MG1) pellicle on the protection of human dental enamel against demineralization.Methods: MGI was extracted from human saliva and purified.MGI pellicle and whole saliva pellicle were formed on dental enamel samples in vitro ,Then The samples were treated by 34 mmol/L citric acid for 1 min.The demineralization of the samples was observed by scanning electronic microscopy(SEM). Results:After treatment by the acid the enamel surfaces covered by MGI pellicles or whol e saliva pellicle showed relatively smooth and normal enamel morphological feat ures, on the contrary the surface without pellicle showed large area of deminer alization and bee nest like appearance. Conclusion: The data indicate that the MG1 in enamel pellicle contribute to its protective effec ts against acidic attack on the enamel surface.

砄bjective:To purify and characterize human high molecular eight salivary mucin(MG1).Methods: MG1 was purified by 10%(w/v) cetyltrimethylammonium bromid precipitation, CM Sephadex ion exchange chromatography and sephadax G 200 gel filtration chromatography. The protein content was studied with Folinin Lowrys analysis and characterized by PAGE and SDS PAGE electrophoresis.Results:The data of PAGE showed that the purified glycoprotein was free of contaminating proteins;those SDS PAGE showed that the melocular weight of the glycoprotein was between Mr 500 000 and 1 000 000.Protein quantitative analysis showed that it contained 14.17% of protein.Amino acid analysis revealed that it contained 17 kinds of amino acid;Thr,Ser,Pro and ALa were the dominant amino acid(45.6% of the total).Conclusion: The data indicate the applied technique is reliable for purification MG1 from saliva.

0bjective: To observe the effects of parotid saliva(PARS), extraparotid saliva(EPS) and purified high molecular weight mucin(MG1) on the aggregation of streptococcus mutans . Methods: PARS, EPS and MG1 were prepared routinely and applied in the cultures of S. mutans Inbritt, S.mutans LM and S.sobrinus OMZ 176 respectively for 2 h. The aggregation of the bacteria was measured spectrophotometrically.Results: The aggregation (%) of S.mutans Inbritt, S.mutans LM and S.sobronus OMZ 176 induced by EPS was 32.80 , 57.87 and 35.46 , that by MGI 25.68, 32.77 and 24.16 , that by PARS 13.52, 22.23 and 16.00, respectively. Conclusion: The effect of MGI on the aggregation of streptoccus mutans is weaker than that of EPS and stronger than that of PARS. The aggregation may be primarily induced by mucins.

AIM To develop a sensitive, specific and reliable reversed phase high performance liquid chromatographic method(RP\|HPLC) to determine the total and unbound(free) concentrations in human plasma of amitriptyline and its major metabolite, nortriptyline. METHODS\ The assay involved a simple extraction procedure. The mobile phase consisted of acetonitrile and distilled water(30∶70, V/V ), containing triethylamine(0 5%) and orthophosphoric acid(0 3%), pH 3 1. Separation was achieved on the C18 ODS column and the effluent was measured for UV absorption at 240 nm. RESULTS The calibration curves were linear in the range of 4～400 ?g?L -1 for total concentration, and in the range of 4～64 ?g?L -1 for free concentration for both amitriptyline and nortriptyline. The lowest limits of detection were 4 ?g?L -1 for both compounds. The absolute recovery rates were 102 0%?3 77% for amitriptyline and 99 3%?7 13% for nortriptyline. The precision values(RSD) of intra day and inter day for both amitriptyline and for nortriptyline were determined to be

Objective To describe the status of nurses′professional identity and the self-concept and to explore the relationship between nurses′professional identity and the self-concept. This will be the base for intervening nurses′professional identity. Methods A convenience sample of 250 nurses from one major hospital in Beijing was recruited. The Macleod Clark Professional Identity Scale and the Professional Self-Concept Instrument were introduced. A standard translation procedure was carried out. Results A total of 250 questionnaires were sent out, 241 questionnaires were withdrawed with an effective rate of 96.4%. The mean score of nurses′professional identity was 42.54±8.70, which was at moderate level. The mean score of nurses′professional self-concept was 86.28 ±22.86, also at moderate level, among which,knowledgescores highest (25.91±6.00), leadership scored 20.84±8.02, inter-personal relationship scored (20.28±4.18), caring scored the lowest (19.25±4.67). There was significant difference among the professional identity in the different departments (P<0.05) , while the same results were not seen in professional self-concept. Nurses′professional identity was positively correlated with professional self-concept′s four dimensions (P<0.05). Conclusions The nurse managers should pay attention to the cultivation of professional self-concept in the training of nurses in order to improve the professional identity of nurses and the whole nurses′development.

AIM　To develop a sensitive, specific and reliable reversed-phase high performance liquid chromatographic method(RP-HPLC) to determine the total and unbound(free) concentrations in human plasma of amitriptyline and its major metabolite, nortriptyline. METHODS The assay involved a simple extraction procedure. The mobile phase consisted of acetonitrile and distilled water(30∶70, V/V), containing triethylamine(0.5%) and orthophosphoric acid(0.3%), pH 3.1. Separation was achieved on the C18 ODS column and the effluent was measured for UV absorption at 240 nm. RESULTS　The calibration curves were linear in the range of 4～400 μg*L-1 for total concentration, and in the range of 4～64 μg*L-1 for free concentration for both amitriptyline and nortriptyline. The lowest limits of detection were 4 μg*L-1 for both compounds. The absolute recovery rates were 102.0%±3.77% for amitriptyline and 99.3%±7.13% for nortriptyline. The precision values(RSD) of intra-day and inter-day for both amitriptyline and for nortriptyline were determined to be <5%, and <8%, respectively. The method was applied to determine the total and free concentrations in plasma of the healthy volunteers after a single oral dose of 50 mg amitriptyline. CONCLUSION　The assay was simple, repid, highly selective and sensitive. It is suitable for the routine analysis of total and free drug concentrations in plasma using readily available instruments with lower cost.

Objective: To study the incidence of ventricular arrhythmia (VT) in heart failure (HF) patients after cardiac resynchronization therapy (CRT-D) and identify the influencing factors for VT occurrence, to explore the impact of CRT-D shocks on mortality and the management of appropriate shocks. Methods: A total of 42 patients with successfully implanted CRT-D in our hospital from 2009-01 to 2015-04 were studied. There were 2 groups of patients: Ischemic cardiomyopathy group,n=12 including 8 patients for primary prevention and 4 for secondary prevention; Non-ischemic cardiomyopathy group,n=30 including 19 patients for primary prevention and 11 for secondary prevention. The patients with appropriate shocks received four step-wise therapy as drug, equipment parameter adjustments, revascularization and radiofrequency ablation (RA). Results: The patients in Ischemic cardiomyopathy group were followed-up for (38.1±24.0) months, 7 patients suffered from post-operative VT, 5 patients had CRT-D appropriate shocks. The patients in Non-ischemic cardiomyopathy group were followed-up for (27.5±17.8) months, 11 patients suffered from post-operative VT, 10 patients had CRT-D appropriate shocks. The occurrence rates of post-operative VT and CRT-D appropriate shocks were similar between 2 groups,P>0.05; the success rate for ATP treating VT was higher in Ischemic cardiomyopathy group (69% vs 55%),P<0.05. Cox regression analysis indicated that CRT-D as secondary prevention was the independent influencing factor for VT occurrence,P=0.001. During follow-up period, 9 patients with shocks died; the mortality in patients with shocks was higher than those without shocks (43% vs 0%),P<0.05. With four step-wise therapy, 80% patients in Ischemic cardiomyopathy group had no more shocks; with three step-wise therapy as drug, equipment parameter adjustments and RA, 90% patients in Non-ischemic cardiomyopathy group had no more shocks, 10% patients had reduced shocks. Conclusion: CRT-D as secondary prevention was the independent impact factor for post-operative VT occurrence, no matter appropriate or inappropriate shocks would elevate the risk of death in HF patients. Step-wise therapy was important to reduce appropriate shocks.

Objective: To explore the antagonistic effect of quercetin on fine particulate matter (PM2.5)-induced embryonic developmental toxicity in vitro.Methods: PM2.5 was collected on glass fiber filters by PM2.5 samplers during the heating period of Dec.2015 to Mar.2016 in an area of Haidian District, Beijing City.The sampled filters were cut into 1 cm×3 cm pieces followed by sonication.The PM2.5 suspension was filtered into a 10 cm glass dish through 8 layers of sterile carbasus and stored at-80 ℃ until freeze drying.Frozen PM2.5 suspension was dried by vacuum freeze-drying.In vitro post-implantation whole embryo culture was used in this study.Pregnant rats with 9.5 gestation days (GD) were killed by cervical dislocation and the uteri were removed into sterile Hank's solution.The embryos with intact yolk sacs and ecto placental cones were induced by PM2.5, and then subjected to intervention of quercetin at the doses of 0.1 μmol/L, 0.5 μmol/L, 1.0 μmol/L and 5.0 μmol/L, respectively.At the end of the 48 h culture period, the cultures were terminated, and all embryos were removed from the culture bottles and placed in prewarmed Hank's solution for evaluation.Morphological evaluation of the embryos was conducted under a stereomicroscope using the morphologic scoring system by Brown and Fabro.The mitochondrial reactive oxygen species (ROS) level was detected by FACSCalibur flow cyto-metry using MitoSOXTM Red staining.Results: An obvious antagonistic effect was achieved through querce-tin at the dose of 1.0 μmol/L, which could result in an increase of visceral yolk sac (VYS) diameter, crown-rump length and head length, somite number, and the differentiation of visceral yolk sac vascular vessels.The scores of allantois, flexion, heart, hind brain, midbrain, forebrain, auditory system, visual system, olfactory system, branchialarch, maxillary process, forelimb bud and hindlimb bud also revealed a significant increase and the relative mitochondrial ROS level of embryonic cells was significantly decreased when compared with PM2.5 group.Although quercetin at the doses of 0.1 μmol/L, 0.5 μmol/L, 5.0 μmol/L also exhibited protective effects against PM2.5-induced embryonic developmental toxicity, the protective effect was weaker when compared with the dose of 1.0 μmol/L.Conclusion: Quercetin at proper dose may be of great benefit for the development of embryos exposed to PM2.5 in the uterus of the rats.Quercetin provides an effective strategy for the prevention of PM2.5-induced embryonic developmental toxicity.Clearance of mitochondrial ROS may be one of its mechanisms.

Objective:To evaluate the immunomodulating effect of oyster peptide on immunosup-pressed mice.Methods:ICR mice injected with cyclophosphamide (CTX)were adopted as the module group,with mice without treatment as the control group,and different dosages of oyster peptide (0.5 g/kg,1 .0 g/kg,and 2.0 g/kg)were given to the low,middle,and high groups for 1 5 days.The body weight,spleen,and thymus weight of the mice,structures under the microscope of the immune organs, numbers of white blood cells,ratios of T lymphocyte subsets,immune cytokines and numbers of nuclear cells,and DNA content in bone marrow were all assessed.Results:Compared with the control group, the structures of thymus and spleen of the mice in the CTX group appeared obscure and shrunk when ob-served under microscope,the number of their white blood cells declined (P =0.04),the proportion of their CD3 +T cells in peripheral blood declined (P =0.003),the proportion of their CD8 +T cells in pe-ripheral blood declined (P =0.002),the concentration of their IL-5 in peripheral blood significantly in-creased (P <0.01 ),the concentration of their nucleated cells and DNA density in bone marrow de-creased (P =0.04,P <0.01 ).Oyster could improve the structures of thymus and spleen of the immuno-suppressed mice.Compared with the CTX group,the number of white blood cells in 2.0 g/kg group in-creased (P =0.003),the proportion of CD3 +T cells in peripheral blood in 1 .0 g/kg group (P =0.04) and 2.0 g/kg group (P =0.02)increased,the proportion of CD8 +T cells in peripheral blood in 2.0 g/kg group increased (P =0.002),the concentration of IL-5 in peripheral blood in all the oyster treated groups increased (P <0.01 in 0.5 g/kg,1 .0 g/kg,and 2.0 g/kg groups),the concentration of IL-1 7 in peripheral blood in 2.0 g/kg group decreased (P =0.03),the concentration of nucleated cells in bone marrow of all the oyster treated groups increased (0.5 g/kg vs.CTX,P =0.04;1 .0 g/kg vs. CTX,P =0.02;2.0 g/kg vs.CTX P =0.01 ),the DNA content in bone marrow of all the oyster treated groups increased (P <0.01 in the 0.5 g/kg,1 .0 g/kg,and 2.0 g/kg groups).Conclusion:Oyster peptide could improve the structures of immune organs of the CTX-induced immunosuppressed mice,re-cover the imbalances of T lymphocyte subsets,improve the immune cytokines and increase numbers of nucleated cells and DNA content in bone marrow,thus improving the immunologic function.

ObjectiveTo review the efficacy and safety in secondary prevention of ischemic stroke with cilostazol or aspirin.Methodswe searched Cochrane Library(the 4th issue, 2009 ), PubMed(1980.1～2009.11), EMBASE(1980.1～2009.11), CBM(1978.1～2009.11), CNKI(1979.1～2009.11) and some other databases, then collected all of the studies describing the outcomes in curing the ischemic stroke after taking cilostazol or aspirin. According to the strict inclusion and exclusion criteria, two reviewers independently selected trials, extracted datas, made cross-checking and methodological quality assessment of the homogeneity studies by using the Cochrane systematic review methods, then made Meta analysis using RevMan 5.0 software.ResultsThis systematic review study included two randomized controlled trials and a cross-over trial, which contained a total of 838 participants. The evidence quality of one of the randomized controlled trials was high, however, the evidence quality of another randomized controlled trial and the cross-over trial was poor. Meta analysis results suggested that the effectiveness of cilostazol and aspirin in the secondary prevention of ischemic stroke performed no significantly statistical difference: primary endpoint(30 d［RR=3.00, 95%CI(0.31,28.70)］; 90 d［RR=1.67, 95%CI(0.40,6.92)］; 180 d［RR=1.25, 95%CI(0.50, 3.13)］; 360 d［RR=0.65, 95%CI(0.33, 1.29)］; 540 d［RR=0.80,95%CI(0.54, 1.18)］); combined endpoint(30 d［RR=4.00, 95%CI(0.45,35.61)］; 90 d ［RR=1.75,95%CI(0.52,5.93)］; 180 d［RR=1.00, 95%CI(0.48, 2.07)］; 360 d ［RR=0.77, 95%CI(0.45, 1.29)］; 540 d［RR=0.66,95%CI(0.40,1.09)］); the recurrence of ischemic stroke: cilostazol group: RR=0.64, 95%CI(0.31,1.30)，aspirin group: RR=0.21, 95%CI(0.04,1.06); PDMP［RR=1.00, 95%CI(0.39, 2.58)］. But in terms of the probability of intracranial hemorrhage (［RR=7.14, 95%CI(0.7,58.33)］) and other safety standards, taking cilostazol performed lower than taking aspirin.ConclusionThe side effects of cilostazol and aspirin in the treatment for ischemic stroke were similar to each other, but in terms of the probability of dizziness, headache, tachycardia and palpitation, taking cilostazol performed higher than taking aspirin, however, taking cilostazol performed lower in the probability of intracranial hemorrhage and other organ hemorrhage than taking aspirin. Since this study included a small amount of studies, in which the evidence quality of one of the randomized controlled trials and the cross-over study was poor, therefore, it would be necessary to make a further validation with lots of high-quality clinical trials.