BACKGROUND:The combination of fiber post and resin core for restorations of mesial or distal defects of the maxil ary central incisor can restore the elastic modulus close to the nature dentin, and achieve good aesthetic effects. However, when a complete dentin col ar cannot be prepared due to a large number of dental tissue defects, the post and core are easy to be lost or fractured after defect repair using the combination of fiber post and resin core.
OBJECTIVE:To compare the stress distribution after nickel-chromium cast post and core, gold-pal adium cast post and core, and fiber post and resin core were used for restorations of mesial or distal defects of the maxil ary central incisors using three-dimensional finite element analysis.
METHODS:An intact adult maxil ary central incisor that meets the average dental anatomical value in China was selected and scanned using a dental cone-beam CT. Then, three-dimensional tooth-fiber post and core (nickel-chromium cast post and core or gold-pal adium cast post and core)-al-ceramic crown models of mesial or distal defects of the maxil ary central incisors and part loss of dentin col ar were established using ABAQUS analysis. After repair with nickel-chromium cast post and core, gold-pal adium cast post and core, and fiber post and resin core, stress distribution in the loaded state was compared using the ABAQUS three-dimensional finite element analysis.
RESULTS AND CONCLUSION:The stress peak at the adhesive and cast layers in the fiber post and resin core group was significantly lower than that in the nickel-chromium cast post and core or gold-pal adium cast post and core group. It indicated that the tooth root was easy to be fractured after mesial or distal defects of the maxil ary central incisors with partial loss of dentin col ar were restored with nickel-chromium cast post and core, gold-pal adium cast post and core. In addition, the stress peaks at the dentin layer were consistent for fiber post and core, nickel-chromium cast post and core, and gold-pal adium cast post and core. These findings indicate that the combination of fiber post and resin core is better for restorations of mesial or distal defects of the maxil ary central incisors.

Objective To observe the biological characteristics and analyse primary therapeutic response of acute erythroid leukemia.Methods The data of 28 patients primarily diagnosed as acute erythroid leukemia were analyzed.The patients were divided into with muhilineage dysplasia group and without muhilineage dysplasia group,and the morphology,immunology,cytogenetics and molecular biology characteristics and the complete remission rate of the first induction therapy were compared.Results There were 14 cases(50％)with muhilineage dysplasia,which involved in two lineage or trilineage.In 6 cases by flow cytometry,the myeloid blast immunophenotypes were common expressed.In 8 cases detected by karyotype analysis,5 cases were chromosomal abnormal,including 4 cases were complex chromosomal abnormal,1 case was trisomy 8.In 4 cases underwent WT1 detection,all of them were positive.The complete remission rate of the first induction therapy was 39.29％(11/28),the ratein the multilineage dysplasia group was 35.71％(5/14),and the ratein without multilineage dysplasia group was 42.86％(6/14),the difference had no statistical significance(P＞0.05).The complete remission rate of the complex chromosome group was 25.00％(1/4),the intermediate prognostic group was 50.00％(2/4).Conclusions Acute erythroid leukemia had special biological features different from other subtype AML:accompanyed with high frequency of multilineage dysplasia.The abnormality of karyotype were high,and it was often complex karyotype involved with chromosome 5 and/or chromosome 7,which had a low complete remission rate.The complete remission rate of chemotherapy was low,treatment effect was poor.

Humans ; Infant ; Lung Diseases ; etiology ; Male ; Milk Hypersensitivity

Arteries ; surgery ; Arteriosclerosis Obliterans ; surgery ; Bioprosthesis ; Blood Vessel Prosthesis ; Blood Vessel Prosthesis Implantation ; instrumentation ; Humans ; Lower Extremity ; blood supply ; surgery

Objective To explore the signification and method of Cut-off verification and gray zone setting in chemiluminescent assay.Methods NCCLS EP-12 A2 document defines that C50 is the analyte concentration of cut off value for immunology qualitative test and C5-C95 interval is the range of analyte concentration that yields 5％ positive results to 95％ positive results for immunology qualitativc test.The C50 and C5-C95 interval of HBeAg in ARCHITECT i2000 were worked out according to the cut off value provided by HBeAg reagent calibrated in ARCHITECT i2000,which were verified to approve the character declaimed by manufactory or not.Gray zone was set and the procedure of cut off verification and gray zone set in chemiluminescent were built; A set of quality control was detected 20 times with two different lot HBeAg reagent kits,S/CO was caculated and compared with t test.Results C50 and C5-C95 interval of reagent (lot 06087L100,96378HN00) were 0.171 PEI U/ml,0.125 PEI U/ml; ＞0.154 PEI U/ml to 0.188 PEI U/ml,0.119 PEI U/ml to ＜0.150 PEI U/ml,respectively.S/CO of negative quality control and positive quality control were (0.550 ±0.038),(2.422 ±0.084) and(0.334 ±0.063),(3.587 ±0.321),respectively.They all approved the character (the sensitivity at cut off was less than 0.5 PEI U/ml)declaimed by manufactory,and the results of S/CO between two lot kits were obvious difference (t =9.944,15.499,P ＜0.01).Conclusion C50 and C5-95 interval can be used to verify cut off value and set gray zone in chemiluminescent assay;They may vary in different lot reagents and they must be verified to approve the character declaimed by manufactory.

Objective To investigate clinical significance of positive antineutrophil cytoplasmic antibodies (ANCA) in diagnosis for vasculitis or other diseases. Methods From January 2005 to December 2008, 104 patients with positive ANCA detected by enzyme-linked immunosorbent assay (ELISA) in People's Hospital of Peking University were randomly selected and their clinical features and diagnoses were analyzed retrospectively. Results Among 104 ANCA-positive patients, 22 were diagnosed as vasculitis and 13 as ANCA-associated vasculitis, and 82 (78. 8% )were diagnosed as non-vasculitis including 40 of connective diseases such as systematic lupus erythematosus (SLE) and rheumatoid arthritis (RA) and 42 of non-connective diseases with the most common of ulcerative colitis. According to the results of ANCA tests by ELISA, ANCA-positive patients could be divided into those with proteinase 3 (PR3)-positive and myeloperoxideaso (MPO)-positive. More organs were involved in MPO-positive patients (n =48 ) than that in PR3-positive ones ( n = 49), and more frequent involvement of the kidneys and less frequent involvement of the gastrointestinal tract in MPO-positive than those in PR3-positive ones (P < 0. 01 ). As compared to those with non-vasculitis, more organs (2. 28 organs vs. 3.55 organs in average) were involved in patients with vasculitis (P <0. 01 ) and more frequent involvement of the upper or lower respiratory tracts and the kidneys in vasculitis patients ( P <0. 01 or <0. 05, respectively). Elevated leukocyte count and accelerated erythrocyte sedimentation rate (ESR) were also more common in vasculitis patients than those in non-vasculitis ones (P <0. 01 and P <0. 05, respectively). Positive ANCA combined with number of organs involved, clinical manifestations and other laboratory findings, its positive predictive value (PPV) in diagnosis for vasculitis can be improved. Conclusions Spectrum of disease in patients with positive ANCA was varied. Diagnostic value of positive ANCA in diagnosis for vasculitis can be improved if combined with comprehensive analysis of their clinical features and laboratory examinations.

Objective To access the effectiveness and safety of traditional Chinese medicine for the patients with post-stroke depression,and provide the evidence for clinical practice.Methods Systematically search(computer and hand) CNKI,VIP,CBM,PUBMED,EMBASE and related magzines for the randomized controlled trials(RCT) and clinical controlled trials(CCT) of traditional Chinese medicine in treating post-stroke depression published.To evaluate and analyze the quality of literature with evidence-based medicine approach.Results 69 RCTs and 6 CCTs met the selection criteria.Only 11 RCTs had proper random methods and 2 RCTs used blind method.There were coparability of groups in 62 RCTs and it was mentioned in 8 researchs of exit and lost.It was showed that the effective rate of treatment group was higher than that of the control group,the ineffective rate and adverse effects in treatment group were lower than that of the control group.4 RCTs were made Meta analysis and quantitative analysis.4 trials were 3 using Jadad Scale,11 trials were 2,other 55 trials were 0～1.Conclusions Large sample,multicentre,prospective randomized trials are needed to strengthen Meta analysis evidence concluded by lower methodological quality of included studies.Furthermore,systematic review should be improved and updated if new evidence appeared.

Objective To investigate the effects of IFN ? and Somatostatin analog octreotide (SMS) on hormone secretion by cultured human GH secreting pituitary adenomas.Methods Each cultured GH secreting pituitary adenoma cells were equally distributed to culture tube and divided into 4 groups: control, IFN ?, SMS, and IFN ?+SMS. Different drugs were added into different groups. The hormone secretion in each group were detected after 2 and 4 days' incubation.Results After 2 and 4 days' incubation with IFN ?(100 IU/ml) GH secretion was significantly inhibited in 6 of 10 and 7 of 10 pituitary adenoma cultures ,reduced by 22%～54% and 30%～61% vs control ( P

Objective To discuss the clinical therapeutic effect of tibia fracture treated by intramedullary nail using limited incision or close reduction.Methods We treated 54 tibia transverse fracture cases,93 oblique fracture cases, 7 1 fragmental fracture cases by intramedullary nail using open with limited incision or close reduction.We then compared operation time,X-ray time,hospital stay duration,infection rate,nonunion rate, and postoperative function restoration between patients with different fractures.Results There was no different operation time in transverse fracture group,but longer for close reduction in oblique fracture group and for open reduction in fragmental fracture group.X-ray time did not differ for open or close reduction in transverse fracture group.Long X-ray time was used in close reduction in oblique and fragmental fracture groups.There was no significant difference in nonunion rate for open and close reduction in both transverse and fragmental fracture groups.The oblique fracture nonuinon rate was higher in close reduction group than in open reduction group.No difference was found in infection rate or function recovery whether for open or close reduction in all types of fractures.Conclusion Different therapy methods should be determined by different fracture types.Open reduction with minimal incision should be used for oblique fracture cases and fragmental fracture cases with reduction difficulty.

Investigation of simvastatin and its related substances was carried out using a reversed phase ultra performance liquid chromatography/tandem mass spectrometry method. The identification of impurities in simvastatin was performed with a triple-quadrupole mass spectrometer, with an electrospray ionization (ESI) source in the negative/positive ion mode. A total of 12 compounds were characterized in commercial samples, among which 2 impurities had never been reported. All the impurities were deduced based on the MS fragment pathways of simvastatin and the biosynthetic pathway of lovastatin. This work provides very useful information for quality control of simvastatin.