OBJECTIVEThe effect of sandblasting on the bond strength between 3mol% yttrium-stabilized tetragonal zirconium polycrystal (3Y-TZP) zirconia framework and veneering porcelain was evaluated.

METHODSA total of 21 specimens [(25 ± 1) mm x (3 ± 0.1) mmx (0.5 ± 0.05) mm] were prepared according to ISO 9693. The specimens were then randomly divided into 3 groups. Sandblasting was performed on 2 meshes of Al₂O₃ particles: group A with mesh 110 and group B with mesh 80. Group C, which was not sandblasted, was the control group. The surface roughness of the zirconia framework, as well as the bond strength between 3Y-TZP zirconia framework and veneering porcelain, was measured. The interface microstructure was observed by scanning electron microscope (SEM), and elemental distribution was detected by energy dispersive spectroscopy (EDS).

RESULTSSurface roughness values were (1.272 ± 0.149) μm for group A, (0.622 ± 0.113) μm for group B, and (0.221 ± 0.065) μm for group C. Statistical significance were found among groups (P < 0.05). The bond strength values were (28.21 ± 1.52) MPa for group A, (27.71 ± 1.27) MPa for group B, and (24.87 ± 3.84) MPa for group C. Statistical significance was found between group A and group C (P < 0.05), whereas the other groups had no statistical significance (P > 0.05). Interface adhesion failure was the primary performance. SEM images showed the close interface bonding, and EDS showed that the interface had no obvious element penetration.

CONCLUSIONAl₂O₃ sandblasting can slightly enhance the bond strength between zirconia framework and veneering porcelain.

Aluminum Oxide ; chemistry ; Dental Bonding ; Dental Porcelain ; chemistry ; Dental Stress Analysis ; Dental Veneers ; Materials Testing ; Microscopy, Electron, Scanning ; Shear Strength ; Surface Properties ; Yttrium ; chemistry ; Zirconium ; chemistry

Objective To investigate the clinical value of a newly designed surgical therapy for familial polyposis coli by severing the superior mesenteric artery&vein in order to make a complete lysis of the mesentery and an ileum pouch and the anal anastomosis within the entire muscular sheath of the rectum.Methods Six patients with familial polyposis coli(5 males and 1 female,aged 24-36 years)were admitted and underwent the procedure which was consisted of:(1)An incision was made in the left middle and lower parts of the rectus abdominis;(2)The greater omentum was retained and the large intestine was removed;(3)At the juncture of the sigmoid colon and the rectum,the muscular sheath was dissociated 0.5cm,the mucous membrane of the rectum was stripped in a revolving manner,the nourishing artery and vein in the membrane were exposed,and clamped and cut in sequence up to the anocutaneoue line;(4)The rectal mucous membrane was completely removed;(5)Under the right colonic artery,the superior mesenteric artery and vein were severed;(6)An N-,J-or W-shaped pouch was made in the ileum accordingly:(7)An anastomosis of the ileum pouch and the anal canal was made within the entire muscular sheath of the rectum,and a drainage was placed;(8)The mesostenium was fixed on the fight posterior abdomen,the small intestines were spread out to the right side,and the mesostenium was covered on the coarse surface of the colon bed:(9)A tube was placed in the left lower abdomen for a vacuum aspiration for 2 days after operation,combined with the suction drainage,to eliminate the pelvic effusions;and(10)The abdomen was closed.Results Patients were able to discriminate stools and flatus 3-7 days after operation.and the formed stools occurred 7-10 days after operation.Five patients were followed-up for 3-17 years,with averagely one defecation a day,with no night defecation and seepage.Urination was normal;In another one patient who underwent the procedure 4 months ago the defecation was twice a day,with no night defecation.All the 6 patients had normal autonomic nerve function and sexual function as well as normal defecation and urination,with no recurrence of polyposis coli or infection.The small bowel functions well with no ischemia related symptoms.Conclusion Cutting the superior mesenteric artery and vein and then making anastomosis of the ileum pouch and the anal canal within the muscular sheath of the rectum is a new surgical approach to familial polyposis coli.It is safe and significantly improves the patients' life quality.

Objective To investigate the molecular regulatory mechanism of glucagon like peptide 1 (GLP-1) on proliferation, differentiation and apoptosis of human umbilical cord blood endothelial progenitor cells (EPCs). Methods EPCs were isolated from the umbilical cord blood of healthy pregnant women and cultured in 6-hole cell plate at 2×105 density in vitro, transfected with empty vector plasmid (control group), pcDNA3-GLP-1 plasmid (GLP-1 group), pcDNA3-GLP-1plasmid+AMD3100 (GLP-1+AMD3100 group) and simple AMD3100 (AMD3100 group). The pcDNA3-GLP-1 was transfected into EPCs. The 25μmol/L AMD3100 was used to block the SDF-1/CXCR4 signal pathway of EPCs for 1 h. The cell proliferation was determined by MTT method. The mRNA expressions of differentiation and apoptosis related genes PPARγ, C/EBPα and Caspase-3 were investigated by RT-PCR, and Caspase-3 activity was determined by Caspase-3 activity assay kit. Results Compared to control group, AMD3100 inhibitor showed no effects on cell proliferation, differentiation and apoptosis, while over-expression of GLP-1 in EPCs obviously promoted cell proliferation, and differentiation related genes PPARγand C/EBPαmRNA expression, but down-regulated mRNA expression and the activity of Caspase-3 significantly (P＜0.05), indicating that GLP-1 increased proliferation and differentiation of EPCs while decreased cell apoptosis. When the SDF-1/CXCR4 signaling pathway was blocked by AMD3100, over-expression of GLP-1 induced promotion of cell proliferation, and the differentiation was decreased significantly and the apoptosis was significantly increased (P＜0.05). Conclusion These data confirm that GLP-1 might promote EPCs proliferation and differentiation, and inhibit cell apoptosis through the regulation of the SDF-1/CXCR4 signaling pathway.

Objective To observe the effects of insulin-like growth factor-2 (IGF2) in the course of mouse embryon-ic stem cells induced to differentiate into islet-like cells. Methods Mouse ES cells were induced to differentiate into islet-like cells in vitro. The expression of islet specific markers was tested by RT-PCR and immunofluorescence assay. RT-PCR/RFLP was used to test the imprinted genes IGF2 parental expression in cells at different stages. Results Islet specific mark-ers were expressed in differentiated cells, such as insulin, glucagon and C-peptide. PCR-RFLP showed that imprinted genes IGF2 derived from embryonic stem cells were biallelic expression and loss of imprinting. Conclusion Gene imprinting sta-tus of IGF2 was changed in differentiated cells in vitro.

Objective To investigate hospital staffs' appraisals on public hospitals reform.Methods 890 medical staffs were randomly investigated by questionnaire,to learn their comments on the implementation of reform measures,public-benefit nature and reform outcomes of the reform,as well as problems found with the government and improvement suggestions,and difficulties encountered in such a reform.Results The hospital staffs' appraisals on the reform tend to be low,as 36.4％ of them hold that the reform is less effective in its outcomes or a mere formality (19.8％).The staff blamed the lack of system breakthrough (67.9％),lack of financial support (61.1％),and insufficient support from the doctors as stakeholders (49.1 ％),for most of the problems of the reform.Conclusion It is suggested to win over support of the medical staff for the reform; to improve the laws and policies related to the reform; and to establish an effective supervision system for public hospitals.

BACKGROUND: Insulin like growth factor 2 (IGF2) is an important embryonic mitosis growth promoting factor, whichplays a critical role in the process of maintaining normal cell growth. The gene expression of IGF2 is under epigeneticregulation in the way of genomic imprinting. Imprinting loss of IGF2 is likely to be associated with the abnormaldevelopment of the individual and tumorigenesis.OBJECTIVE: To investigate the effect of imprinting loss of IGF2 gene on the differentiation of mouse embryonic stemcells into islet-like cells.METHODS: Two kinds of mouse embryonic stem cells (SF1-G and SF1-1) were induced to differentiate into islet-likecells in vitro. The expression of Insulin gene was detected by real-time PCR and cell immunofluorescence. Theexpression of IGF2 was detected by the polymerase chain reaction-restriction fragment length polymorphism in the cellsbefore and after induced differentiation. The level of insulin released at terminal differentiation stage was tested by insulinrelease assay in vitro.RESULTS AND CONCLUSION: (1) There was no change in the imprinting state of the two kinds of mouse embryonicstem cells with normal and imprinted IGF-2 gene before and after differentiation. (2) In the induced cells, the expressionlevel of insulin in the SF1-1 group was higher than that in the SF1-G group, although there was no significant differencein the insulin release between the two kinds of cells. (3)The imprinting loss of IGF-2 gene may be related to theup-regulation of insulin mRNA expression in terminal cells during induced differentiation.

Objective To study the CT manifestations of delayed traumatic hematomas of the brain and evaluate their diagnostic significance in predicting the delayed traumatic brain hematoma. Methods The manifestations of initial CT studies and follow-up CT examinations of 31 delayed traumatic brain hematomas were analyzed. Another 50 CT studies of head trauma without delayed brain hematomas were included randomly as control. Results The abnormal findings of CT studies of the 31 delayed traumatic brain hematomas included: (1)Decreased density of the local brain parenchyma and disappeared difference between gray and white matter of the same area in 18 cases; (2)Local subarachnoid space hemorrhage in 24 cases; (3)Slight mass effect of local brain parenchyma in 16 cases. (4)Subdural hematoma in 9 cases. The locations of the abnormalities were roughly the same with the delayed hematoma except one local subarachnoid space hemorrhage, which was in the opposite of the delayed hematoma. The appearing rate of those abnormal findings in the control group was low and the difference was statistically significant. Conclusion The decrease of density of local brain parenchyma, the disappeared difference between the gray and white matter, local subarachnoid space hemorrhage, and local swollen of brain presented in the initial CT study of the patient with head trauma should be taken as indicators of delayed hemorrhage of the same area of brain, and it is necessary to do follow-up CT studies to exclude it.

Objective To study the characteristics of patients with low body mass index (BMI) chronic obstructive pulmonary disease(COPD). Methods A total of 38 clinically stable patients with moderate-to-severe COPD were enrolled. They were divided into two groups: underweight (UW) group (n=16,BMI<20);normal weight(NW) group(n=22, 20≤BMI<26). Body height and weight, smoking indexs, and six minutes walk distance (6MWD) were assayed. The British Medical Research Council (MRC) dyspnea scale was used to assess the degree of dyspnea. St. George's Respiratory Questionnaire (SGRQ) and Short Form 36 item Questionnaire (SF-36) were used for health-related quality of life (HRQoL) evaluation. The serum concentrations of leptin and ghrelin were detected by enzyme-linked immunosorbent assay (ELISA). Results Compared with the NW group, the inspiratory eapacity(IC), forced expiratory volume in one second (FEV), vital capacity (VC) ,most ventilate volume (MVV) and peak expiratory flow(PEF) were lower(P<0. 05) in the UW group. Residual volume-to-total lung capacity ratio (RV/TLC), smoking indexs and MRC score were higher (all P<0. 05) and 6MWD was significantly lower (P<0. 05) in the UW group than in NW group. Activity scores,impact scores and total scores of SGRQ showed significant deterioration in the UW group (P<0. 05). SF-36 also showed significantly worse scores for the parameters of the emotional and social functioning (P < 0. 05 ). Serum leptin was significantly lower ( P< 0.01 ) and ghrelin was higher in UW group than in NW group (P<0. 05). Stepwise multiple regression analyse showed that lC,mental health(MH) and physical function (PF) of SF-36, leptin,6MWD and smoking indexs were independently correlated with BMI. Conchtsions The pulmonary function, nutritional status, PF and life quality of COPD patients with low BMI were more deteriorative. The most significant influencing factor for BMI in COPD patients was IC. M H,exercise capacity,leptin level and smoking indexs were independently correlated with BMI in COPD patients. It is important to retrieve low BMI in the management of COPD patients.

Objective To explore the clinical efficacy and complications of the surgical treatment of sternal tumor resection and titanium mesh reconstruction.Methods From 2008 January to 2012 June,there were 8 cases of sternal tumor patients in our hospital,including 5 male and 3 female,with an average age of 50.4 (37-66) years old.The histological morphology included 2 cases of chondrosarcoma,1 case of osteosarcoma,2 cases of malignant fibrous histiocytoma,eosinophilic granuloma in 1 case,and 2 cases of sternal metastasis of breast cancer.Tumor invasion sites included the sternal manubrium in 3 cases,the body in 2 cases,and both in 3 cases.All patients had undergone preoperative puncture or incision biopsy.8 cases of sternal tumor patients were treated with sternal tumor resection and reconstruction of the thorax using titanium mesh.The clinical effect and complications were retrospectively analyzed.Results All patients were followed up for 9 months to 4 years.The operations went well in all cases,with no intraoperative crisis or operative death.Deep wound hematoma occurred in 1 patient 1 week postoperatively,who healed 2 weeks after drainage and debridement.There was no abnormal breathing,subcutaneous emphysema,pneumothorax,infection or other complications in other cases.1 case of malignant fibrous histiocytoma died of lung metastasis at 9 months follow-up,and 1 died of liver metastasis at 14 months,while other patients got no tumor recurrence,with good thoracic shape,free breathing,no titanium mesh loosening,dyspnea,chest tightness,pain,or abnormal respiratory discomfort during follow-up period.The chest radiograph showed no chest deformity,no loosening or fracture of the fixation device.Conclusion Sternal tumor resection and reconstruction with titanium mesh has the advantages of good shaping effect,fewer complications,and simple operation,showing that titanium mesh is an ideal material for the reconstruction of sternum.

Tumors of the cardiac conduction system (CCS) have rarely been reported. The CCS from 198 cardiac-related deaths (GroupⅠ),and 838 deaths from non-cardiovascular diseases or trauma (Group Ⅱ ), were studied. Sampling was done of the sinoatrial node (SAN)and atrio-ventricular node (AVN) along their long axis of each node as a single block and the His bundle (HB) perpendicular to its long axis in 2-4 blocks. Five-micron serial sections were made; tissue slices were taken intermittently, every 20th from the SAN, every 10th from the AVN, and every 30th from the HB and bundle branches (BB), by continuous slices three times. Tumors in the CCS were found in 12 cases (1.155 %), where 10 (0.965%) were primary tumors, and 2 (0.193%) were metastatic tumors. The primary tumors included 4 fibromata compressing the HB (0.386 %), 4 hemangiomata (0.386%), 1 AVN tumor (0.097 %), and 1 rhabdomyoma (0.097 %). In 8 of the 10 cases, the tumors were located in the AVN or HB. The metastatic tumors originated from lymphocytic leukemia and malignant lymphoma (histiocytic type) in lung, and were all found in the SAN. Of the 12 cases, 2 were from the group Ⅰ. Tumors in the CCS are the smallest tumors in different parts of the body, which can cause sudden death.