Mechanical Behavior of Radial Support of a Novel Balloon Expandable Tapered Stent / 医用生物力学

Objective To explore influences of the taper and connecting rib form on supporting performance of the stent, and provide an important scientific basis for structural design and clinical selection of the tapered stent. Methods A nonlinear finite element model for radial support performance of a novel balloon-expandable tapered stent was constructed, and the radial stiffness (RS) and stress distributions of the stent at different tapers (0°, 0.565°and 1.13°) and with different structural forms of stent linker (V-shape, I-shape, C-shape, S-shape, M-shape) were analyzed by plane compression. The relationship between structural design of the vascular stent and its radial support performance was studied. Results The RS of 0°stent, 0.565°stent, 1.13° stent was 2.51, 1.61, 0.85 N/mm, respectively. The RS of 0.565°stent and 1.13° stent was 35.86% and 66.14% lower than that of 0°stent (round straight stent), respectively. Except that the RS of C-shape linker stent was 1.48 N/mm, the RS of I, M, S and V-shape linker stents was not significantly different, which was 2.51, 2.61, 2.41, 2.52 N/mm, respectively, indicating that radial compression resistance of these four linker stents was almost the same. Conclusions Compared with traditional round straight stents, the RS of tapered stents will decrease, and the RS of stents will gradually decrease with the the taper increasing. Among all stent types in this study, except C-shape linker stents, the RS of other linker shapes has little effect on the RS of stents. The radial support performance of the stent can be improved by reducing the taper of the tapered stent, without changing the form of stent connecting ribs.

A preliminary study on index system construction of the merging reform of doctoral degree education in clinical medicine with the standardized training of specialists / 中华医学教育探索杂志

Objective:To explore the reform plan for the integration of doctoral degree education in clinical medicine and standardized training for specialists.Methods:Using the literature analysis method and expert interview method, the preliminary framework of the merger training program was initially constructed, and Delphi method was used to determine the final index system. Excel 2010 was used to make data entry, and SPSS 19.0 was used for statistical analysis.Results:After two rounds of inquiry, the preliminary framework of the merger training program was finally determined from six aspects: enrollment methods, training resources, training content, training methods, training assessment and quality control, including 6 first-level indicators, 26 second-level indicators and 72 third-level indicators.Conclusion:By scientifically formulating systematic training programs, establishing the core training content and comprehensive evaluation system with post competency, and using flexible academic system, it provides a basis for carrying out the reform of the integration of doctoral education of clinical medicine and standardized training of specialists.

Genomic characterization and pathogenic study of two porcine reproductive and respiratory syndrome viruses with different virulence in Fujian, China

Two strains of porcine reproductive and respiratory syndrome virus (PRRSV) were isolated in 2006 and 2016 and designated as FZ06A and FZ16A, respectively. Inoculation experiments showed that FZ06A caused 100% morbidity and 60% mortality, while FZ16A caused 100% morbidity without death. By using genomic sequence and phylogenetic analyses, close relationships between a Chinese highly pathogenic PRRSV strain and the FZ06A and FZ16A strains were observed. Based on the achieved results, multiple genomic variations in Nsp2, a unique N-glycosylation site (N³³→K³³), and a K151 amino acid (AA) substitution for virulence in the GP5 of FZ16A were detected; except the 30 AA deletion in the Nsp2-coding region. Inoculation experiments were conducted and weaker virulence of FZ16A than FZ06A was observed. Based on our results, a 30 AA deletion in the Nsp2-coding region is an unreliable genomic indicator of a high virulence PRRSV strain. The Nsp2 and GP5 differences, in addition to the virulence difference between these two highly pathogenic PRRSV strains, have the potential to be used to establish a basis for further study of PRRSV virulence determinants and to provide data useful in the development of vaccines against this economically devastating disease.

Immunogenicity of tandem expression recombinant EG95s protein of Echinococcus g ranulosus / 中国人兽共患病学报

In order to analyze the immunogenicity of the recombinant EG95s protein ,the recombinant plasmids of pET-1EG95s ,pET-2EG95s and pET-3EG95s which containing respectively 1 ,2 ,and 3 copies EG95s were induced to express HIS-1EG95s ,HIS-2EG95s and HIS-3EG95s ,and then the proteins were purified and identified by western-blotting .The same im-mune process was used ,and 8 weeks-old BALB/c mice were immunized ,then its immunogenicity was analyzed by detecting an-tibody levels in mice by indirect ELISA method .Results showed that for recombinant EG95s proteins after transformation , HIS-1EG95s ,HIS-2EG95s ,and HIS-3EG95s also retained immunogenicity and could induce specific antibodies in mice .One week's late after the first immunization with HIS-1EG95s ,the antibody level of was significantly higher than HIS-2EG95s and HIS-3EG95s .But began from 2 weeks after immunization ,the antibody level of HIS-3EG95s was always higher than that of HIS-1EG95s group during the period of the immune .Both the final antibody titers after immunization of HIS-1EG95s and HIS-2EG95s groups was 1∶819 200 ,while HIS-3EG95s group was 1∶163 840 0 .HIS-1EG95s ,HIS-2EG95s and HIS-3EG95s all induced IFN-γin immune mice ,but the difference was not significant .The HIS-1EG95s showed lower response to Echinococ-cus granulosus positive serum than HIS-2EG95s and HIS-3EG95s .It’s indicated that the HIS-1EG95s and HIS-3EG95s also had good immunogenicity .HIS-3EG95s make recombinant protein immunic effects more lasting ,and benefit to generate more long-lasting protective immunity .This study provides the scientific basis for the immunization of echinococcosis (hydatidosis) .

Different concentrations of icariin for bone defect repair:disputes and exploration / 中国组织工程研究

BACKGROUND:As one of the main active ingredients in epimedium, icari n plays an important role in bone defect repair. Sustained and effective concentration of icari n in vivo is essential for bone damage repair. OBJECTIVE:To recommend the research progress of epimedium glycoside for bone repair and to explore the pharmaco-active concentration of icari n. METHODS:A computer-based online search of CNKI database (http://www.cnki.net/) and PubMed database (http://www.ncbi.nlm.nih.gov/PubMed) from January 2000 to October 2013 was performed for related articles of the effect of icari n for bone defect repair and bone damage repair. The key words were“icari n, concentration, bone”in Chinese and English. After repeated articles were excluded, 76 related articles were screened out and 44 of them met the inclusive criteria. RESULTS AND CONCLUSION:The icari n-released scaffold materials can induce the osteogenic differentiation of bone marrow-derived mesenchymal stem cells, promote the viability of osteoblasts and inhibit the resorption of osteoclasts, thus repairing bone tissue. It is certain that icari n promotes cellular dif erentiation, however whether it can promote cellular proliferation remains unclear. The pharmaco-active concentration of icari n ranges from10-8 to 10-5 mol/L, but clinical trial has not yet been carried out, and specific drug concentration is uncertain, which needs further exploration.

Effect of amiloride pretreatment on lipopolysaccharide-induced acute lung injury in rats / 中华麻醉学杂志

Objective To investigate the effect of amiloride pretreatment on the acute lung injury (ALI)induced by lipopolysaccharide (LPS) in rats. Methods Thirty-two pathogen-free male SD rats weighing 200-250 g were randomly divided into 4 groups (n = 8 each); group Ⅰ received iv normal saline (group C); group Ⅱ ALI received iv LPS 6 mg/kg (group ALI); group Ⅲ received iv amiloride 10 mg/kg (group A) and group Ⅳ received amiloride 10 mg/kg iv 30 min before iv LPS ( group AL). The animals were killed by exsanguination at 6 h after iv LPS infusion. The lungs were immediately removed. Microscopic examination of lung tissue was performed. The left lung was lavaged. The total protein (TP), TNF-α and macrophage inflammatory protein-2 (MIP-2)concentrations in broncho-alveolar lavage fluid (BALF) were measured. The W/D weight ratio and the myeloperoxidase (MPO) activity and expression of Na-H exchanger-1 ( NHE1 ), p38MAPK and extracellular signal-regulated kinase (ERK) in lung tissue were determined. Results LPS significantly increased ALI score (0 = slightest, 4 = severest), W/D lung weight ratio, TP, TNF-α and MIP-2 concentrations in BALF and MPO activity and the expression of NHE1, p38MAPK and ERK in the lung as compared with. control group. Amiloride pretreatment significantly attenuated LPS-induced changes except p38MAPK expression. Conclusion Pretreatment with amiloride can attenuate LPS-induced ALI by inhibition of ERK activation.

Chemotatic factor expression induced by angiotensin Ⅱ in A549 cells / 中华急诊医学杂志

Objective To investigate the effects of angiotensin Ⅱ on nuclear transcription factor-кB(NF-кB)and interleukin-8(A549 cells),and to explore the underlying mechanisms of ventilator-induced lung injure. MethodA549 cells were maintained in Dulbecco' s modified Eagle's culture medium at 37℃ with 5 ％ CO2 incubator. The cells were randomly (random number) divided into 4 groups (n =24 in each). The group A was control group. The group B,C and D had A549 cells co-incubated with Angiotensin Ⅱ 10-6 mmol/L (final concentration) for 1 h,2 h and 4 h, respectively. The samples of cell culture supematant,total cellular RNA and nuclear proteins were collected or extracted after culture of cells. The II-8 contents in cell culture supernatant were detected with enzyme linked immunosorbent assay(FLISA) .The expressions of IL-8 mRNA were measured by reverse ttanscription-polymerase chain reaction (RT-PCR).The NF-κB activities were assayed with electrophoretic mobility shift assay (EMSA). The levels of NF-κB p65 subunit were detected with Western blot. The overall differences were compared by using analysis of variance(ANOVA). Differences between two groups were assessed by q tests. ResultsThe levels of IL-8 content in cell culture supematant in groups A, B, C and D were (29.59+8.36) pg/mL,(135.35 + 28.93) pg/mL,(357.12+ 57.21) pg/mL,and (1732.13+ 261.73) pg/mL,respectively(group A vs. group B, P ＜0.01; group B vs group C, P ＜0.01;group C vs. group D, P ＜ 0.01 ) The overall differences between gtoups were statistically significant ( F =58.41,P ＜ 0.05). The expressions of IL-8 mRNA in groups A, B, C and D were (0.13±0.03)Au·nm,(0.49+0.08) Au·mm,(0.71 ±0.10) Au·mm and (0.88±0.11) Au·mm,respectively (group A vs. group B, P ＜0.01; group B vs. group C, P ＜ 0.01; group C vs. group D, P ＜ 0.05. The overall differences between groups were statistically significant (F = 19.08, P ＜ 0.05). The NF-κB activities in groups A, B, C and D were (70.37±6.57) Au·mm,(139.76± 11.72) Au·mm,(198.90± 18.95)Au·mm and (388.73±26.27) Au·mm, respectively (group A vs. group B, P ＜0.01,group B vs. groupC, P ＜0.05; group C vs. group D, P ＜ 0.01 ). The overall differences between groups were statistically significant ( F = 23.15, P ＜ 0.05). The levels of NF-κB p65 subunit in groups A, B＜ C and D were (33.05±6.23) Au·mm, (73.97 ± 5.34) Au·mm,(168.72± 8.40)Au·mm and (254.63 + 12.2) Au·mm, respectively (group A vs. group B, P ＜0.01; group B vs. group C, P ＜0.01; group C vs. group D, P ＜0.01). The overall differences between groups were statistically significant (F = 16.33,P ＜ 0.05). Conclusions The Ang Ⅱ can significantly activate the NF-κB system and up-regulate the expression of IL-8 in human lung adenocarcinoma cell line, which cause neutrophil infiltration and activation. This effect is time-dependent and induces acute lung injure, playing an important role in the underlying mechanisms of ventilator-induced lung injure.

Purification of large-scale plasmid DNAs by selective precipitation with cetyltrimethylammonium bromide / 生物工程学报

Following Escherichia coli lysis with alkali, cetyltrimethylammonium bromide (CTAB) was directly titrated into the supernatant. An easy and feasible technology for plasmid purification was established with the optimized proportion between the quantity of CTAB and plasmid, combined with the specific solution for DNA release and TritonX-114 for endotoxin removal. Quality detection showed that the purified plasmid was free of contamination of host RNA. The host bacterial genomic DNA, endotoxin and bacterial protein were less than 10 microg, 50 EU and 10 microg per mg plasmids, respectively. The ratio of OD260/OD280 was between 1.75-1.85. Eighty percent of the prepared plasmids were presented in the supercoiled form. The plasmid purified with this technology can satisfy all criteria stipulated by FDA. The main advantages of the technology include the avoidance of animal-derived enzymes such as ribonucleases A, Proteinase K and toxic reagents like chloroform and phenol. In addition, the technology has low cost and no pollution.

Therapeutic progress of ischemic cerebrovascular disease / 中国临床药理学与治疗学

The improving brain circulation is the most important aspect in protecting brain from the ischemic trauma. This frauma on pathophysiology includes the two stages which are related to different treatments. The paper induced some therapeutic progress, such as thrombolytic therapy, the use of anticoagulation agents, antiplatelet drugs, neuroprotectine agents, intracerebral transplantation, antiedama, and reducing intracranieal pressure.

A study of correlation between hyponatremia and plasma C-type natriuretic pepide level in patiants with hypertensive intracerebral hemorrhage / 临床神经病学杂志

Objective To investigate the relationship between hyponatremia(HN) and the plasma level of C-type natriueetic peptide(CNP) in patients with hypertensive intracerebral hemorrhage(HICH).Methods Radioimmunoassay was applied to determine the plasma concentrations of CNP in 36 patients with HICH and the concentrations of serum sodium were measured.Results The mean plasma level of CNP in 6 cases with HN(24.6?3.98 mg/ml ) was significantly increased compared with that in 26 cases without HN(21.1?3.23 mg/ml)( P

Attempts of How to Stimulate Students'Interest in Microbiology Teaching / 微生物学通报

Enforcing microbiology teaching and helping students gain comprehensive knowledge on microbiology have always been the goal for the teachers concerned,since microbiology plays an important role both in theory and in practical life.In microbiology teaching,how to stim- ulate students' interest is crucial to the teaching aim.This article mainly argues four items such as encouraging students participate in teach- ing,employing multimedia,optimizing contents of the textbook and integrating theory,and practice in that teaching.