The effect of saliva contamination on the shear bond strength of orthodontic brackets, at various stages of the bonding procedure using a new self-etch primer was studied. The samples were divided into 4 groups according to 4 different enamel surface conditions: Group A: dry; Group B: saliva contamination before priming; Group C: saliva contamination after priming, and Group D: saliva contamination before and after priming. Stainless steel brackets were bonded in each test group with a light-cured composite resin (TransbondXT 3M). The shear bond strength was determined in the first 30 min after bonding. The analysis of variance indicated that the shear bond strengths of the 4 groups were significantly different (F = 11.89, P < 0.05). Tukey HSD tests indicated that contamination both before and after the application of the acid-etch primer resulted in a significantly lower (=4.6 +/- 1.7 MPa) shear bond strength than either the control group (=8. 8 +/- 1.9 MPa) or the groups where contamination occurred either before ( = 7.9 +/- 2.0 MPa) or after (= 6. 9 +/- 1.5 MPa) the application of the primer. It was concluded that the new acid-etch primer could maintain adequate shear bond strength if contamination occurred either before or after the application of the primer. On the other hand, contamination both before and after the application of the primer could significantly reduce the shear bond strength of orthodontic brackets.
Acid Etching, Dental ; Orthodontic Brackets ; Saliva ; Shear Strength

AIM:To investigate the differences of clinical signs and pathological structure of unilateral nasal pterygium and unilateral double pterygium.METHODS:Retrospective study.Totally 11 unilateral nasal pterygium and 11 unilateral double pterygium were collected to observe the size of the tissue area, the classification of blood vessels, the transparency and the break-up time of tear film.The 11 surgically excised double pterygia (11 eyes) and 6 samples of normal conjunctiva were collected for the study.With 40g/L paraformaldehyde fixation, paraffin sections were stained with Haematoxylin-Eosin, to observe the differences with nasal and temporal pathology under light microscope.RESULTS:In unilateral double pterygium, the tear break-up time was significantly shorter than that of unilateral nasal pterygium (t=3.410, P=0.003).In unilateral nasal pterygium, there was a significant negative correlation between tear film break-up time and tissue size(r=-0.927, P<0.01) and transparency(r=-0.764,P<0.01).In unilateral double pterygium, the tear break-up time was significantly negatively correlated with the growth time (r=-0.661, P<0.05), tissue size (r=-0.775, P<0.01) and transparency (r=-0.671,P<0.05).In unilateral double pterygium, compared with the temporal side, the quantity of the layers of corneal epithelial cells (t=-7.351, P<0.05), vessels (t=-7.400, P<0.05) and inflammatory cells (t=-7.481, P<0.05) increased.CONCLUSION:Compared with unilateral nasal pterygium, the tear film break-up time of unilateral double pterygium was poor.In unilateral double pterygium, with high activity, the degree of proliferation of squamous epithelium, hyperplasia and inflammatory reaction are significantly higher than those of the temporal side.

Osteoclastic bone resorption and osteoblastic bone formation are coordinated as a coupled mechanism to effect the development of bone and to maintain bone homeostasis. Recently reported Eph/ephrin bidirectional signaling between osteoclasts and osteoblasts plays a pivol role in bone homeostasis and casts new light on coupling of bone resorption and bone formation, which is gaining more and more attention in researches of bone biology and bone diseases. The present article aims to address the researches on the Eph/ephrin bidirectional signaling between osteoblasts and osteoclasts with molecular constitution, mechanism of the signal transduction, biological significance and so on.

Objective:To observe HSP70 expression during experimental tooth movement in rats.Methods:Orthodontic appliance was placed between the maxillary right first molar and maxillary central incisors of 30 adult SD rats.The rats were killed at 1,3,5,7,14 d after orthodontic force application,samples of experimental teeth with periodontal tissue were prepared for immunohistochemical examination of HSP70 expression.Result:Strong expression of HSP 70 in periodontal ligment was observed at 1 and 3 d after orthodontic force application,positive at 5 d and weak positive at 7 and 14 d.Conclusion:HSP 70 is expressed in periodontal ligment at different levels in different stages during orthodontic tooth movement.

Humans ; Proteomics ; methods ; Silicosis ; metabolism ; Specimen Handling ; methods

Objective To study the relationship between the prevalence of thyroid dysfunction and components of metabolic syndrome.Methods A total of 10 461 working and retired employees aged 20 to 90 years in a Petrochemical Corporation in Ningbo were included.Body mass index ( BMI),waist circumference,blood pressure,fasting blood glucose,blood lipid profile,serum thyroid-stimulating hormone (TSH),free thyroxine ( FT4 ),and free triiodothyronine (FT3 ) were measured in all subjects. Metabolic syndrome was diagnosed according to the International Diabetes Federation(IDF) criteria.Results ( 1 ) The prevalences of metabolic syndrome and overall thyroid dysfunction were 10.2％ and 4.6％,respectively. ( 2 ) 18.1％ petrochemical employees had abdominal obesity with at least one component of metabolic syndrome.( 3 ) There was no significant difference in the prevalence of metabolic syndrome among the groups with lowered,normal,and elevated TSH. (4) Logistic regression analysis revealed that lowered high density lipoprotein cholesterol ( HDL-C ) was associated with lowered TSH ( OR =0.313,95％ CI 0.184-0.530 ),and raised triglyceride was associated with elevated TSH ( OR =0.767,95％ CI 0.595-0.991 ). ( 5 ) There were significant associations between serum TSH levels and lipid parameters such as total cholesterol in males,triglyceride and low density lipoprotein cholesterol in females,and HDL-C in both genders.Conclusion The prevalence of thyroid dysfunction was not associated with central obesity,hypertension,and hyperglycemia.Lipid disorder was correlated with serum TSH levels.

Aim To study the effect of high salt diet during pregnancy on the development of renal vessels in offspring rats and its mechanism.Methods Natural pregnant Sprague-Dawley rats were randomly divided into high-salt group and control group.The pregnant rats in the high-salt group were given high-salt diet of 8% NaCl content , while the control group normal diet with 1% NaCl content.In both groups, pregnant rats were given normal drinking water.After delivery, all mothers returned to normal diet and all neonatal rats were breast-fed until one month old.The adult male off springs were used as experimental animals.The vessel tone of renal interlobar arteries and electrophysiological behavior of single vascular smooth muscle cells (VSMCs) were detected respectively.Results The contractile response of renal arteries to phenylephrine(Phe) in high-salt group was stronger than that in the control group(P<0.05).The effect of protein kinase C(PKC) non selective blocker GF109203X on Phe-induced contraction in two groups also showed significant difference(P<0.05).In electrophysiology experiments, Phe inhibited high-conductance Ca2+-activated K+ channel(BK channel) currents in renal arteriolar smooth muscle cells in two groups, and the inhibitory effect was more pronounced in high-salt offsprings (P<0.05).GF109203X could eliminate the response of Phe on BK currents in both groups(P>0.05).Conclusions High-salt diet during pregnancy could increase the sensitivity of renal interlobar arterial contractile response to Phe in adult male offsprings, which is associated with PKC-mediated BK channels pathway.Maternal high-salt diet during pregnancy may increase the risk of renal vascular diseases in adult offsprings.

Objective To study the effect on Henoch-Schnlein purpura nephritis with cyclophosphamide (CTX) intravenous pulse therapy.Methods Fourty cases of Henoch-Schonlein purpura nephritis were divided into observation group and control group.The observation group:8～10 mg/(kg?time) of CTX was added into 100 mL of saline which was dropped intravenously,2 days was a period of treatment, intermission of 30 d, and the total duration was 4-6 months. The control group only applied prednisone and dipyridamole.Results After CTX pulse therapy 24 h proteinuria determination and hematuria decreased obviously. The effect before and after therapy had significant difference (P

Objective To evaluate the skills in using inhalers among the asthmatic patients who visited the out-patient clinic and whether or not the nursing intervention could further improve the efficacy of the drug delivery device. Methods 321 asthmatic patients who had visited the clinic and prescribed inhalers from April to December 2009 were investigated of the basic status, former medication history and skills in using metered dose inhaler (MDI) and dry powder inhaler (DPI). Nursing intervention had been carried out and the results were analyzed. Results Subjects belonging to different educational level groups were significantly different in mastering skills using MDI and DPI after reading instructions. There also existed significant difference between MDI and DPI users. Among patients who had already used inhalers, there was significant difference between subjects who had received instruction from medical personnel and subjects who had only read paper directions. Nursing intervention could significantly improve the skills in handling the device. Conclusions Proper skills in using inhalers could not be possessed just by reading paper directions. Instructions or even multimedia presentation from medical personnel are vital for asthmatic patients to master the skills in using MDI and DPI.

Objective To learn the status quo of core competency of registered nurses in tertiary level first-class hospitals in Liaoning Province and compare the level and characteristics of core competency of registered nurses in different working years in order to supply evidence to establish contrapuntal training protocol.Methods "The Competency Inventory for Registered Nurse scale"(CIRN,by LIU Ming)was distributed to investigate the core competency of registered nurses,the data underwent analysis.Results The overall score of core competency level was (174.11±31.89),the score of the nurses with 16～20 years of working experience was the highest,while the score of nurses working for 1～5 years was the lowest.The core competency varied with working years,evident difference existed in different dimensions and total scores.Conclusions The overall core competency is at the upper middle level for registered nurses from five tertiary level first-class hospitals in Liaoning Province.They are competent enough to provide health care.With the increasing length of working time,nurses' core competency level will strengthen gradually.