Objective:To study the movement regularity of Ca~(2+) in tooth hard tissue.Methods:14 extracted intact caries-free teeth were cleaned and then immersed into artificial saliva in a divice with 3 chambers for enamel part,dentin part and cement part respectively.The concentration of Ca~(2+) in the chambers was measured with an ion meter,TECHNICON(AXON,USA),24 h after immersion of each tooth.Results:The Ca~(2+) concentration in tooth immersed fluid of enamel part was higher than that of dentin part(P

0.05). Conclusion: There is surface potential in teeth and the potent ial can be affected by the electrolyte surroundings.

Objective To analyze the factors contributing to local recurrence following body gamma knife radiotherapy in patients with non-small cell lung cancer(NSCLC),and to explore a standard therapeutic scheme under the circumstance.Methods 332 patients with NSCLC received body gamma knife therapy and subsequent regular follow-up.Dose per fraction and total dosage used were dependent on disease condition,tumor location,tumor features and tumor size,etc.On the basis of patients' conditions and adverse effects,biological effective dose(BED) was 56-90Gy calculated with LQ model.Univariate analyses were performed including sex,age,Karnofsky performance score,clinical stage,pathological type,tumor differentiation degree,tumor size,tumor location,target volume delineation,dose per fraction,BED and chemotherapy scheme,etc.with X2 or t test.By selecting significant clinical factors in univariate analysis,multivariate analyses were performed with COX regression model.Results Of the 332 patients,local recurrence occurred in 22 cases during regular follow-up period,with average recurrence time of 10 months,and the local recurrence rate was 6.63%.The results of multivariate analysis showed that low BED,low Karnofsky score,old age,too small delineation for target volume range and central type of lung cancer were the factors related to local recurrence.Conclusions Low BED in body gamma knife radiotherapy is the significant factor of local recurrence for patients with NSCLC.BED in body gamma knife radiotherapy should be more than 80Gy for NSCLC patients who receive the radical treatment.

Objective To evaluate the therapeutic effects and complications of whole body gamma knife conformal radiotherapy for patients with non-small cell lung cancer(NSCLC).Methods 169 patients with NSCLC received whole body gamma knife conformal radiotherapy.Total dose,fractions,and radiation time were determined based on disease course,tumor location,tumor features and tumor volume,etc.Small target volume(tumor size less than 3cm in diameter) received 5-10Gy each time,40-50Gy in 4-10 fractions;moderate target volume(tumor size 3cm-5cm in diameter) received 4-8Gy each time,48-56Gy in 4-16 fractions;and big target volume(tumor size more than 5cm in diameter) received 3-4Gy per time,40Gy in 10-14 fractions and followed by 10-30Gy using reduced fields.Results Of 269 tumors in 169 patients,complete response(CR) rate,partial response(PR) rate,and rate of no change(NC) were 41.6%(112/269),44.6%(120/269) and 13.8%(37/269),respectively.Overall response rate(CR+PR) was 86.2%(232/269),with 1-year local control rate of 92.3%.1-year and 2-year survival rate was 75.1% and 46.2%,respectively,with median survival time of 19 months.The incidence of Grade 1,2 and Grade 3 radiation pneumonia was 15.4% and 3.1%,respectively.Conclusions With minor adverse effects,whole body gamma knife conformal radiotherapy may have short-term therapeutic effects for NSCLC patients with amelioration of disease symptoms,obvious elevation of tumor local control rate,a raise of the survival rate,and improvement of life quality.

Objective To investigate the correlation between serum levels of 25 hydroxyvitamin D and immunoglobulin E(IgE)in adults.Methods There were 1 969 participants over the age of 19 were enrolled in this studied,serum total IgE,dermatophagoides farinae(Df)-specific IgE,and serum 25(OH)D levels were analyzed.Other variables included sex,age,body mass index,smoking history,and economic status were collected.Adjusted regression analysis was used to examine the independent association of 25(OH)D with serum IgE levels.Results The average serum 25(OH)D level of 1 969 patients was(18.0±6.5)μg/L,the prevalence of asthma,allergic rhinitis,and atopic dermatitis were 15.2％(299/1 969),2.8％(63/1 969)and 3.0％(68/1 969)respectively,however,there was no significant difference in serum 25(OH)D levels in patients with allergic rhinitis.All subjects were divided into four groups according to the serum 25(OH)D level: Q1:less than and equal to 13.4 μg/L,Q2:more then and equal to 13.4 μg/L but less then and equal to 17.0 μg/L,Q3: more then and equal to 17.0 μg/L but less then and equal to 21.7 μg/L,and Q4: more than and equal to 21.8 μg/L.The median TIgE level increased with higher quartiles in the Kruskal-Wallis test.The prevalence of Df in Q1,Q2,Q3,Q4 group were 39.8％,33.2％,38.7％and 43.1％,respectively.Linear regression analysis indicated that 25(OH)D levels were positively correlated with lgTIgE(regression coefficient:0.011,95％CI 0.001-0.021),25(OH)D in male patients with dust mite allergy was positively correlated with lgTIgE(regression coefficient:0.026,95％CI 0.010-0.043).There was no significant correlation between 25(OH)D and lgTIgE in the other groups.Conclusion Adult serum 25(OH)D levels is positively correlated with total IgE levels.

Objective To evaluate the efficacy of cold preservation solution containing desferrioxamine (DFO) in protecting the rat hearts.Methods Pathogen-free male Sprague-Dawley rats,weighing 300-350 g,were used in the study.Thirty-two isolated rat hearts were equally and randomly divided into control group (C group) and DFO group using a random number table.Hearts of rats were stored for 6 h in 4 ℃ histidine-tryptophan-ketoglutarate (HTK) solution in group C.DFO was added to HTK solution (DFO concentration 100 μmol/L),and hearts of rats were stored for 6 h in 4 ℃ HTK solution in group DFO.At 6 h of cold storage,creatine kinase and lactate dehydrogenase activities in the cold preservation solution were determined.Myocardial specimens were obtained from the apex,cut into sections which were stained with haematoxylin and eosin,and examined under a microscope.The pathological changes of myocardial tissues were scored.The content of malondialdehydc in myocardial tissues was determined using thiobarbitnric acid method,and hypoxia-inducible factor-1α protein and mRNA expression in myocardial tissues was detected by real-time reverse transcriptase polymerase chain reaction and Western blot.Results Compared with group C,the creatine kinase and lactate dehydrogenase activities in the cold preservation solution,malondialdehyde content in myocardial tissues,and pathological scores were significantly decreased,and the expression of hypoxia-inducible factor-1α protein and mRNA expression in myocardial tissues was significantly up-regulated in group DFO (P＜ 0.05).Conclusion Cold preservation solution containing DFO can protect the rat hearts effectively,and the mechanism is related to up-regulation of the expression of hypoxia-inducible factor-1α.

A three-dimensional finite element model of premaxillary bone and anterior teeth was established with ANSYS 13.0. The anterior teeth were fixed with strong stainless labial archwire and lingual frame. In the horizontal loading experiments, a horizontal retraction force of 1.5 N was applied bilaterally to the segment through hooks at the same height between 7 and 21 mm from the incisal edge of central incisor; in vertical loading experiments, a vertical intrusion force of 1.5 N was applied at the midline of lingual frame with distance between 4 and 16 mm from the incisal edge of central incisor. After loading, solution was done and displacement and maximum principle stress were calculated. After horizontal loading, lingual displacement and stress in periodontal membrane (PDM) was most homogeneous when the traction force was 14 mm from the edge of central incisor; after vertical loading, intrusive displacement and stress in PDM were most homogeneous when the traction force was 12 mm from the incisal edge of central incisor. The results of this study suggested that the location of center of resistance (CRe) of six maxillary anterior teeth is about 14 mm gingivally and 12 mm lingually to incisal edge of central incisor. The location can provide evidence for theoretical and clinical study in orthodontics.
Dental Models ; Dental Stress Analysis ; Finite Element Analysis ; Humans ; Incisor ; Maxilla ; Periodontal Ligament ; Tongue

Objective To investigate the effect of propofol on the cerebral injury induced by ketamine in neonatal rats. Methods Eighty 7-day-old SD rats of both sexes, weighing 12-20 g, were randomly divided into 4 groups (n = 20 each): normal saline (NS) group, ketamine-induced cerebral injury group (group K), propofol group (group P) and propofol combined with ketamine group (group PK). Group NS received intraperitoneal NS 1 ml. In groups K, P and PK, ketamine 70 mg/kg, propofol 70 mg/kg and propofol 70 mg/kg + ketamine 70 mg/kg were injected intraperitoneally once every 2 h for 3 times respectively. Ten rats in each group were selected and sacrificed at 24 h after emergence from anesthesia and the hippocampi obtained to determine the neuronal apoptosis (by TUNEL) and Bcl-2 and Bax protein expression(by immunohitochemistry). The apoptosis rate was calculated.The other 10 rats in each group were selected at 21 days after the intraperitoneal injection and the learning and memory functions (escape latency and frequency of crossing the original platform) were evaluated using Morris water maze. Results Compared with group NS, the apoptosis rate was significantly increased in group K, Bcl-2 protein expression was up-regulated in groups P and PK, and Bax protein expression was up-regulated, the escape latency was significantly prolonged and the frequency of crossing the original platform was significantly decreased in the other groups (P ＜ 0.05 .or 0.01 ). Compared with group K, the apoptosis rate was significantly decreased in group PK, Bax protein expression was down-regulated in group P, and Bcl-2 protein expression was up-regulated,the escape latency was significantly shortened and the frequency of crossing the original platform was significantlyincreased in groups P and PK ( P ＜ 0.05). Conclusion Propofol can reduce the cerebral injury induced by ketamine in neonatal rats, and the regulation of the Bcl-2 and Bax protein expression and inhibition of the neuronal apoptosis in hippocampus may be involved in the mechanism.

Objective To assess the protective effect of the proteasome inhibitor bortezomib on rat liver subjected to bile duct obstruction. Methods Thirty rats were divided randomly into three groups, which were sham-operation group (SO group), bile duct ligation control group (Con group) and bortezomib group (Bor group). All rats in the Con group underwent ligation of the common bile duct, and rats in the Bor group were given bortezomib intrabominally at-1 d, 4 d post-ligation of the common bile duct. All the rats were sacrificed at 7 d post-surgery. ALT, TB and TBA levels were determined. The expression of NF-κB p65 was assessed using immunohistological staining. RT-PCR was employed to detect TNF-α mRNA levels in liver samples. Results There was no significance in the levels of TB and TBA between Con and Bor groups. The ALT revel in the Bor group [(92.4±21.4)μmol/L]was significantly lower than that in the Con group [(145.7 ±33.5) μmol/L], P＜0.05. The positive staining rate of NF-κB p65 subunit in the Bor group showed significant lower value (11.6% ±2.7 % ) compared to that in the Con group (15.5 %±4.3 % ), P＜0.05. The expression ratio of TNF-α mRNA in the Bor group was 1.0± 0. 2, which also significantly lower than that in the Con group (1.3±0.4), P＜0. 05. Conclusion These data suggest that the proteasome inhibitor bortezomib reduces rat hepatocyte injury in the bile duct ligation by mechanisms associated with the inhibition of NF-κB as well as the attenuation of inflammation.

This study was aimed to establish quality standards of fruit of Hippophae tibetana Schlechtend.. The medical material was identified by microscopy and thin layer chromatography (TLC). According to methods recorded in the Chinese Pharmacopoeia (2010 edition), the contents of moisture, total ash, acid-insoluble ash and alcohol-sol-uble extract were determined. The HPLC method was applied in the determination of quercetin, kaempferol and isorhamnetin content. The results showed that the microscopic characteristics of Tibetan medicine H. tibetana were identified. The TLC and content determination methods of quercetin, kaempferol and isorhamnetin were estab-lished. It was concluded that the established qualitative and quantitative methods can be used for quality control of the fruit of H . tib e tana.