BACKGROUND: The physical property of porcelain fused to metal (PFM) differs from those of its constituents, which nake impacts on PFM,and the mechanical property of most composites can be estimated with mixture rule. However, there are various factors influencing the mechanical property of PFM and great differences found in the estimations, thus it is necessary to combine the theoretical analysis of mechanical property and mechanics of materials by matbematical models, and provide guidances for PFM' s application.OBJECTIVE: To explore the experiment and computing methods of mechanical analysis on PFM repair materials, and analyze its correlativity and internal relation.DESIGN: Three-point bending experiment and mixture rule of the composites were applied to measure and calculate the intensity and modulus of materials, and then the experimental results and computations were compared.SETTING: Repair Department of Stomatology, West China Stomatological College.MATERIALS: According to the different metal-porcelain ratios, 15 PFM test pieces of 26 mm×4 mm×1.5 mm were divided into 5 groups, with 3 in each.METHODS: Three-point bending experiment was used to detect the bending level and elastic modulus of PFM, whose changing rule was observed,and then was compared with theoretical computed value as well as study the correlation.MAIN OUTCOME MEASURES: PFM experimental result, theoretical computation and the comparison of the two,RESULTS: There were obvious correlations between the experimental measurement and theoretical results, which indicated that the mechanical property of PFM could be predicted by the revised formula.CONCLUSION: The mechanical property of PFM has regular relations with the geometrical morphous parameter and mechanical parameter of PFM constituents, and can be predicted and improved by revised theoretical formula.

In order to investigate the role of Twist gene in the metastasis of hepatocellular carcinoma (HCC), total RNA was respectively extracted from three HCC cell strains with different metastatic potentials, HepG2, MHCC-97L and MHCC-97H. The first strand cDNA was synthesized by reverse transcription, which was then used as template to perform fluorescent quantitative polymerase chain reaction (FQ-PCR). The quantity of Twist gene expression was normalized by that of the housekeeping gene, GAPDH for each sample. ANOVA was used to estimate the relationship between Twist gene and metastasis potential of HCC. The results showed that the normalized initial cDNA concentrations of Twist gene in HepG2, MHCC-97L and MHCC-97H were (9.45+/-0.25)x10(-4), (1.82+/-0.41)x10(-3), (3.06+/-0.62)x10(-3), respectively. FQ-PCR revealed significant differences in the expression level of Twist among HCC cell strains with different metastatic potentials. It was concluded that high expression level of Twist was closely associated with more aggressive behaviors of HCC. Twist provides a novel indicator for HCC metastasis.
Carcinoma, Hepatocellular/*metabolism ; Cell Line, Tumor ; DNA, Complementary/metabolism ; Dose-Response Relationship, Drug ; Gene Expression Regulation, Neoplastic ; Liver Neoplasms/*metabolism ; Neoplasm Metastasis ; Nuclear Proteins/*biosynthesis ; Polymerase Chain Reaction ; RNA/metabolism ; Twist Transcription Factor/*biosynthesis

This paper focuses mainly on the study of optimal fermentation conditions of S-adenosyl-L-methionine.Effects of carbon sources,nitrogen sources,inorganic constituents,growth factors and adding time of L-methionine on the yield,the content and biomass of S-adenosyl-L-methionine are studied.And ingredients of the culture medium are also optimized by the method of uniform design.The final optimum culture medium contains: glucose 30 g,Yeast powder 11 g,(NH_4)_2SO_4 12 g,K_2HPO_4?3H_2O 5 g,KH_2PO_4 10 g,MnSO_4?H_2O 0.09 g,ZnSO_4?7H_2O 0.14 g,MgCl_20.5 g,CaCl_2 0.3 g,CuSO_4 0.005 g per liter. Using that optimum culture medium,the yield of S-adenosyl-L-methionine can reach 0.9 g/L in Erlenmeyer flask which is 30 % higher than before.Experiment on 5 L fermenter reveals that the accumulation of S-adenosyl-L-methionine can reach 2.66 g/L.Biomass is 23.4 g/L.

Clinical characteristics were retrospectively analyzed in a patient with parathyroid crisis as the main symptoms of parathyroid adenoma and asymptomatic pheochromocytoma.This analysis was aimed to implement specific diagnosis and treatment and to accumulate experience in managing these diseases.

Objective To evaluate cerebrospinal fluid adenosine deaminase(CSF-ADA)activity in the diagnosis of tuberculous meningitis(TMB), and to observe its dynamic changes. Methods A total of 160 patients were included and were divided into two groups: 76 cases of TBM and 84 cases of non-TBM.Among the cases of non-TBM, there were 36 cases of bacterial meningitis, 30 cases of viral meningitis and 18 cases of cryptocoocal meningitis. All the patients were measured with their CSF-ADA activity by Enzymecoupled assay(Trinder method)and 47 patients of TBM were measured again after 2 weeks' and 6 weeks'antitubercular therapy. Results were expressed as(-x)± s. Mann-Whitney U test and paired-samples t test were used. Results CSF-ADA activity in TBM group was(12.9 ±6.4)U/L, while that in the non-TBM group was(6.0 ± 4.1)U/L, the difference was of statistical significance(U = 7.860, P ＜ 0.05). With the cutoff value of 9 U/L, the sensitivity and specificity to differentiate TBM from non-TBM was 84.21% and 83. 33%, respectively. CSF-ADA activity decreased in TBM patients after antitubercular treatment.Conclusions CSF-ADA activity can be an effective laboratory marker for early differential diagnosis of TMB with the cut-off value of 9 U/L. Dynamic changes of CSF-ADA activity may be a indicator for the effect of antitubercular treatment.

Objective: To investigate the effects of Radix Ginseng and Radix Notoginseng formula on secretion of vascular endothelial growth factor (VEGF) and expression of vascular endothelial growth factor receptor-2 (VEGFR-2) in human umbilical vein endothelial cells (HUVECs) in vitro. Methods: HUVECs were cultured in vitro. Bovine basic fibroblast growth factor (bFGF) at concentration of 320 U/mL and Radix Ginseng and Radix Notoginseng formula at concentrations of 0.1, 0.2 and 0.4 mg/mL were used to culture with HUVECs. And HUVECs in blank control group were cultured with culture solution only. After 24-hour culture, the content of VEGF in supernatant was detected by enzyme-linked immunosorbent assay and the expression of VEGFR-2 was detected by immunocytochemical staining and Western-blotting. Results: Radix Ginseng and Radix Notoginseng formula at 0.4 mg/mL, the same as bFGF, increased VEGF content in the HUVEC supernatant and the number of VEGFR-2-positive HUVECs. Expression of VEGFR-2 protein in high-dose Radix Ginseng and Radix Notoginseng formula group was up-regulated as compared with the blank control group. Conclusion: Radix Ginseng and Radix Notoginseng formula can promote HUVEC proliferation and secretion of VEGF, as well as the expression of VEGFR-2 protein, which may be one of the mechanisms of Radix Ginseng and Radix Notoginseng formula in promoting angiogenesis.

Aneurysm, Dissecting ; surgery ; Aorta, Thoracic ; surgery ; Humans ; Male ; Middle Aged ; Stents

Aged ; Humans ; Male ; Middle Aged ; Mycoses ; complications ; Nasal Septal Perforation ; complications ; microbiology ; Sinusitis ; complications ; microbiology

Objective To evaluate the clinical diagnostic contribution of 18 F-FDG PET/CT in giant cell arteritis with initial presentation as fever of unknown origin (FUO).Methods Eight cases with initial presentation as FUO diagnosed with the contribution of PET/CT were retrospectively studied in Peking Union Medical College Hospital.The radiologic manifestations of PET/CT were analyzed.Results Eight patients (4 men and 4 women) with average (63 ± 7) years (range from 55-75 years) were included in our study based on the criteria.Non-specific clinical symptoms were common in these patients,including fatigue,night sweat and weight loss.They all suffered from anemia of chronic disease.Not surprisingly,the inflammatory parameters were elevated significantly in all patients.The medical history,physical examination and routine lab and radiologic examinations couldn't reveal the causes of fever.PET/CT was performed in all of them,which demonstrated intense 18F-FDG uptake in the area of aorta and its major branches with maximal standard uptake value (SUVmax) 2.1-4.6 (3.6 ± 0.9).Immunosuppressive agents were effective to control the inflammation activity.The SUV decreased significantly after treatment in the follow-up PET/CT.Conclusions PET/CT has demonstrated high yield of diagnostic contribution in giant cell arteritis with initial presentation as fever of unknown origin.As to elderly FUO patients presenting with prominent inflammatory reaction,PET/CT may provide potential value to differentiate diagnosis from maligancies.