Humans ; Periapical Periodontitis ; diagnosis ; etiology ; therapy ; Root Canal Therapy ; adverse effects

Humans ; Root Canal Obturation

Humans ; Root Canal Therapy ; instrumentation ; methods

Dental Pulp Cavity ; anatomy & histology ; Humans ; Root Canal Preparation ; methods

Dental Pulp Cavity ; abnormalities ; pathology ; Humans ; Root Canal Therapy ; methods

Objective To study the levels of Urotensin Ⅱ(UⅡ)in the different grades of obstructive sleep apnea syndrome(OSAHS)patients and the correlation of UⅡ to OSAHS.Methods Seventy-five OSAHS patients were divided into five groups according to light,medium,serious AHI,simple snorers and normal part;UⅡ levels of the plasma were measured and correlation analysed.Results UⅡ levels:light group(10.44?4.12)ng/L、medium group(38.55?15.8)ng/L、serious group(94.78?19.63)ng/L、simple snorers group(1.37?0.42)ng/L、normal group(1.14?0.65)ng/L.Statistic difference existed among these groups(P

Many factors can result in X ray film overthick and overthin in medical X-ray radiation.In order to ensure the correctness of diagnosis and the focus can be presented at the proper time,it is very im- portant for the overthick and overthin film to be processed and corrected.It has been proved through the test that the satisfied result can be reached through the proper regulating measure such as making a copy of a film.

BACKGROUND:The mechanical performance and cytocompatibility of polylactic acid-polyethylene glycol (PLA-PEG) scaffold is poor via long-term experiments; therefore, other materials are added to the scaffold in order to improve its biological activity and mechanical properties. OBJECTIVE:To investigate the preparation process of carbon fiber (CF)-PLA-PEG scaffold, and to test its performance. METHODS:Modified CF-PLA-PEG composite scaffolds were prepared using solution injection-particle leaching method. Ultra-structure, porosity, water-absorbing quality, degradation rate and mechanical properties of CF-PLA-PEG composite scaffolds and PLA-PEG scaffolds were compared. Rat osteoblasts were co-cultured with these two kinds of scaffoldsin vitro, and the cel adhesion rate was detected by precipitation method after 12 hours. Cel counting was detected using MTT method to determine the cel proliferation at culture days 1, 3, 5, 7, 9. RESULTS AND CONCLUSION:The surface structure of PLA-PEG distributed uniformly, and the aperture was (404.0±10.5) μm. The carbon fiber surface of modified CF-PLA-PEG composite scaffolds had a lot of longitudinal grooves, the surface structure also distributed uniformly, and the aperture was (433.0±3.0) μm. Difference in scaffold aperture was of significance between the two groups (P < 0.05). The porosity, water-absorbing quality, elasticity modulus, compressive strength, degradation rate, cel adhesion rate and cel growth rate of CF-PLA-PEG were better than those of PLA-PEG (P < 0.05). These results show that the CF-PLA-PEG scaffolds have good mechanical property and cel compatibility.

BACKGROUND:Absorbable bio-glass injection composed by bio-glass and calcium phosphate bone cement can be tightly combined with bone tissue by a strong chemical bond to improve the stability of the bone-implant interface.
OBJECTIVE:To investigate the effect of absorbable bio-glass injection to support the vertebral body of osteoporosis mice and its mechanism of osteogenic induction.
METHODS:Osteoporosis models were prepared in 30 female Sprague-Dawley rats undergoing bilateral ovariectomy. After modeling, model rats were randomly divided into three groups, and given polymethylmethacrylate, injectable calcium phosphate bone cement and absorbable bio-glass injection into L3-5 vertebral bone defects, respectively. L3-5 segments were removed at 12 weeks after implantation to detect the biomechanical and degradation properties, levels of calcium and phosphate, alkaline phosphatase activity, bone mineral density, levels of bone morphogenetic protein 2 and transforming growth factor β, as wel as histological observation.
RESULTS AND CONCLUSION: In the absorbable bio-glass injection group, the degradation properties, compressive strength, surface hydroxyapatite deposition amount and bone mineral density were significantly higher than those in the other two groups(P< 0.05); trabecular bone relative volume, thickness and number were significant higher than those in the other two groups (P < 0.05); serum levels of calcium, alkaline phosphatase, bone morphogenetic protein 2 and transforming growth factor β were significantly higher than those in the other two groups(P < 0.05); but the level of serum phosphate was lower than that in the other two groups(P < 0.05). These results show that the absorbable bio-glass injection can enhance the support for the osteoporotic vertebral body and induce osteogenesis, probably by increasing bone morphogenetic protein 2 and transforming growth factor β levels.

Objective To establish an animal model of high-iodine and low-protein in Wistar rats,and to observe the effect of combined excess-iodine and low-protein diet on growth,metabolism and morphological changes in thyroid.Methods According to body weight[(110 ± 10)g] and sex(half male and half female),one hundred and ninety-two Wistar rats,1 month after weaning,were randomly divided into ① normal iodine control group (NI),② 10-fold excess-iodine group (10HI),③ 50-fold excess-iodine group (50HI),④ 100-fold excess-iodine group (100HI),⑤ low-protein control group (LC),⑥ low-protein and l 0-fold excess-iodine group (L10HI),⑦low-protein and 50-fold excess-iodine group (L50HI),⑧ low-protein and 100-fold excess-iodine group(L100HI).Twenty-four rats were in each group,with the experimental period of 6 months.The iodine content of NI and LC groups was 4.65 μg/d; 10HI,50HI and 100HI groups were 46.50,232.50 and 465.00 μg/d,respectively.The animal's body weight,water and feed consumption were recorded weekly.At the end of 60,120,180 days,urine and blood samples were collected from eight rats in each group.Urinary iodine was tested by arseni cerium catalytic spectrophotometry; serum iodine was tested by the method of chloric acid.Histological change of the thyroid gland was observed by transmission electron microscopy and hematoxylin-eosin (HE) staining at the end of 6 months; apoptosis of thyroid was tested by terminal-deoxynucleoitidyl transferase mediated nick end labeling (TUNEL) method.Results At the end of 4,8,16,18,22 and 24 weeks,the differences of body mass of rats among groups were statistically significant(F =4.26,3.75,4.98,4.09,3.28,3.95,all P ＜ 0.05).At the end of 60,120,180 days,the differences of iodine concentration in urine and blood among groups were statistically significantly (H =5.37,6.03,all P ＜ 0.05).Light microscopy showed that thyroid follicular epithelial cells became flattened,and follicles became distended with colloid following increasing of iodine concentration.Electron microscopy showed increased glial vesicles,condensation of nuclear chromatin,karyopyknosis,and karyolysis with increasing of iodine concentration.The differences of apoptotic indexes among groups were statistically significant (F =4.59,P ＜ 0.01).The apoptotic indexes of L50HI and L100HI groups [(21.50 ± 5.20)‰,(26.70 ± 6.40)‰] were higher than those of 50HI and 100HI groups [(11.20 ± 4.30)‰,(19.40 ± 4.80)‰,P ＜ 0.01 or ＜ 0.05].Conclusion Excessiodine and low-protein can cause growth retardation,abnormal iodine metabolism,and thyroid follicular epithelium damage in Wistar rats.