Objective To investigate the radiation and radioprotection in bedside digital radiography. Methods 650 cases undergoing X-ray examination in sugical wards are involved. Results The patients' X-ray radiation dose is 3.12~7.68 mGR. Conclusion To avoid unnecessary radiation, radioprotection should be emphasized when improving images' quality.

BACKGROUND:Previous studies have demonstrated that simvastatin that can promote osteogenic differentiation of bone marrow stromal stem cel s in vitro, is likely to be a new osteogenic drug. While it is stil unknown whether there is time-dependent stimulation of simvastatin on the expressions of bone morphogenetic protein 2 and col agen type I. OBJECTIVE:To investigate the expressions of bone morphogenetic protein 2 and col agen type I in rat bone marrow stromal stem cel s in vitro stimulated by simvastatin at different time points. METHODS:Passage 1 bone marrow stromal cel s were divided into control and simvastatin group, fol owed by cultured in osteogenic differetiation medium with or uithout 10-7 mol/L simvastatin. After 7-day intervention, expression of alkaline phosphatase was detected in passage 3 cel s. Passage 4 cel s were divided and cultured as described above, and afterwards, RNA and proteins were extracted at 12 and 36 hours to detect the expressions of bone morphogenetic protein 2 and col agen type I using real-time PCR and western blot assay. RESULTS AND CONCLUSION:Both two groups could express alkaline phosphatase, while the rate of positive cel s significantly increased in the simvastatin group compared with the control group (P<0.05);at 12 and 36 hours after intervention, mRNA expressions of bone morphogenetic protein 2 and col agen type I in the simvastatin group were significantly higher than those in the control group (P<0.05). Besides, western blot assay showed:at both 12 and 36 hours, simvastatin significantly enhanced the expression of bone morphometric protein 2, while the expression of col agen type I significantly increased at 12 hours (P<0.05), but not at 36 hours. In conclusion, simvastatin can promote the expressions of bone morphometric protein 2 and col agen type I in rat bone marrow stromal cel s, with more favorable outcomes after 12-hour treatment.

Objective:To evaluate the immunogenicity of recombinant factor H binding protein(fHBP) by detecting serum antibody titer and serum bactericidal antibody test (SBA).Methods:fHBP sequence was selected and synthesized, connected to plasmid pET43.1a, transformed to Escherichia coli BL21(DE3), and expressed two recombinant fHBP proteins, included two subfamilies, fHBPA and fHBPB. After purification, the recombinant fHBP proteins were immunized to rabbits and mice. The immune antiserum titer and the bactericidal titer to epidemic strains of meningococcal bacteria group B were measured by ELISA and SBA respectively. Results:The antiserum titer of fHBP immunized rabbits was greater than 2.0×10 6, and that of immunized mice was not less than 1.0×10 6. fHBP immunized rabbit serum had bactericidal titer more than 1∶128 to 41 strains A subfamily and 20 strains B subfamily in the SBA against 69 endemic strains, and there was no cross-protection between the subfamily bacteria. The bactericidal titers of mouse serum immunized fHBPA to strains A subfamily such as Nm210902 Nm211009、Nm450522 were 1∶1 024, 1∶608、1∶861, to Nm510703、Nm311304、Nm431002 were 1∶234、1∶861、1∶430 respectively, and mouse serum immunized fHBP B to strains B subfamily Nm311302、Nm311304、Nm431002 were 1∶876、1∶274、1∶1858, all of three strains were positive in bactericidal titers. Conclusions:the titer of fHBP antiserum was higher than 1.0×10 6, the bactericidal titer was no less than 1∶128 to 61 epidemic strains, and it has a 94.2% protective effect on 69 meningococcal epidemic strains group B.

To explore the safety and efficacy of levosimendan in treating the patients with severe aortic stenosis and to analyze the cardial function before and after medication in order to guide clinical treatment. Methods: A total of 20 patients admitted in our hospital from 2014-01 to 2015-12 were enrolled with the standard of echocardiography confirmed severe aortic stenosis, left ventricular ejection fraction (LVEF)≤45%, NYHA III-IV and inefficacy for conventional anti-heart failure drug therapy. The patients received intravenous infusion of levosimendan at 0.1μg/(kg·min) by persistent pumping for 24 hours. Echocardiography, LVEF, dyspnea condition, NYHA grading and plasma levels of NT-proBNP were recorded pre- and post-medication to compare the cardiac function and symptoms of levosimendan therapy. Results: After levosimendan treatment, NYHA grade was improved, P=0.025 and NT-proBNP was reduced (9101.6±7368.0) pg/mLvs (13776.5±9503.7) pg/mL, P=0.018. The following parameters were similar before and after levosimendan therapy: LVEF (31.1±7.5)% vs (33.1±8.5)%, P=0.078, the average heart rate (79.6±13.8) bmp vs (82.8±9.5)bmp, P=0.200 and systolic blood pressure (99.6±11.7) mmHg vs (97.2±12.1) mmHg, P=0.071. There were 40% (8/20) patients with obviously improved and 50% (10/20) with improved dyspnea symptoms after levosimendan treatment. Conclusion: Our preliminary study presented that levosimendan could improve NYHA grading, remit dyspnea symptom and reduce blood NT-proBNP level in patients with severe aortic stenosis and heart failure; it had safety and tolerability at certain degree in clinical practice.

Objective: To explore the cardiac function and outcomes in patients of aortic stenosis (AS) after transcatheter aortic valve replacement (TAVR) within 6 months in order to provide the guidance for clinical treatment. Methods: A total of 49 consecutive severe AS patients with surgical contradiction or STS high risk score and received successful TAVR in our hospital from 2013-12 to 2015-12 were studied. Echocardiography and blood levels of NT-proBNP were examined at pre- and 1 month, 6 months after TAVR. Left ventricular ejection fraction (LVEF), aortic valve mean gradient (MG), peak gradient (PG) and peak velocity (PV) were recorded. Based on pre-operative LVEF, the patients were divided into 2 groups: Cardiac dysfunction group, LVEF<50%,n=15 (30.6%) and Normal cardiac function group, LVEF≥50%, n=34 (69.4%). Post-operative cardiac function and blood levels of NT-proBNP were compared between 2 groups. Results: In all 49 patients, the following parameters were significantly improved within 7 days after TAVR: LVEF (56.0±14.6) % vs (52.5±13.8)%, MG (11±5) mmHg vs (58±18) mmHg, PG (21.7±9.5) mmHg vs (93.0±28.6) mmHg, PV (2.3±0.5) m/s vs (4.8±0.7) m/s, blood NT-proBNP level [1831 (1098-3363)] pg/ml vs [3842 (1763-8664)] pg/ml and aortic valve area (1.57±0.43) cm2 vs (0.58±0.23) cm2 allP<0.05. Within 6 months after TAVR, LVEF was continuously increasing especially in Cardiac dysfunction group; MG, PV and NT-proBNP level were continuously decreasing, NYHA grade was continuously improving, allP<0.05. Conclusion: TAVR was an effective treatment in AS patients with surgical contradiction or STS high risk score; it may continuously improve cardiac function, especially in patients with left heart dysfunction.

Traumatic fractures and stress fractures are common orthopedic diseases,and there is great potential in researching bone turnover,repair,and promotion of fracture healing.Basic medical experiments often use animal models of long bone fractures in limbs to study the mechanisms of various interventions on fracture healing.Fracture healing is a complex process influenced by multiple factors and involves multiple molecules and pathways.Therefore,to explore the mechanisms more deeply,accelerate the translation of results,and improve the clinical efficacy,it is particularly important to choose the appropriate animal fracture modeling methods in experimental research.Based on this,this paper conducts a literature review of animal species and modeling methods commonly used for long bone fracture models in experimental research.It summarizes five methods:bone defect method,physical impact method,mechanical bending method,open osteotomy method,and drilling method.A side-by-side comparison of their advantages,disadvantages,and scope of application is made,aiming to provide suitable fracture models for studyingthe mechanisms of fracture healing interventions.

Objective: To investigate the impact of aortic root morphology on the implantation depth of aortic valve prosthesis during trans-catheter aortic valve replacement (TAVR) in bicuspid aortic valve patients. Methods: Clinical data of 40 patients with native bicuspid aortic valve stenosis who underwent TAVR using the self-expandable prosthesis (the Venus A-valve) from 2014 to 2017 in Fuwai Hospital was retrospectively analyzed. The patients were divided into non-deep implantation group (implant depth ≤10 mm by instant angiogram after implantation,29 cases) and deep implantation group (implant depth> 10 mm by instant angiogram after implantation,11 cases).Pre-procedural aortic root characteristics (e.g. calcification, angle and dimensions) were assessed by CT. The impact of aortic root morphology on the implantation depth and clinical outcomes were also evaluated. Results: The age was (75.1±5.9) years with equal representation from the raphe-type and non-raphe type (52.5%(21/40) and 47.5%(19/40)).The bigger aorta angle ((56.5±4.5)° vs. (47.4±9.4)°, P=0.004),more frequent mild-calcification (HU850, <200 mm³) or severe-calcification(HU850, >1 000 mm³) of aortic leaflets (7/11 vs. 4/29, P=0.006), as well as higher ratio of left ventricular outflow tract perimeter to annulus perimeter ((109.2±7.5)% vs. (101.5±6.5)%, P=0.004) were found in the deep implantation group compared to the non-deep implantation group. The new in-hospital onset of bundle-branchheart-block or atrioventricular block conduction disturbance rate was higher in the deep implantation group than in the non-deep implantation group (6/11 vs. 2/29, P=0.030).Left ventricular ejection fraction was similar between deep implantation group and non-deep implantation group at baseline((49.9±8.9)% vs. (55.8±10.4)%, P=0.117), and was significantly lower in the deep implantation group than in the non-deep implantation group at 30 days after implantation ((51.6±12.8)% vs. (60.9±8.1)%, P=0.020). Conclusion Aortic root morphology of bicuspid aortic valve patients is associated with implantation depth of the prosthesis during TAVR, which affects the conduction system and left ventricular function during and post TAVR.

Objective To evaluate the efficacy of tigecycline plus prolonged high-dose meropenem infusion in the prevention and treatment of early carbapenem-resistant Klebsiella pneumoniae (CRKP) infection after renal transplantation .Methods From January 2016 to December 2018 ,clinical data were retrospectively analyzed for 13 renal transplant recipients with graft-carried CRKP .The relevant clinical data included treatments and outcomes of grafts and recipients .KPC-2 gene was the only resistance gene detectable in all isolates of CRKP . Among 13 CRKP positive recipients ,there were positive cultures of graft preservation solution ,recipient blood & urine (n=1) , positive cultures of graft preservation solution & urine (n=1) ,positive cultures of graft preservation solutions & peri-graft drainage (n=3) ,continuous positive cultures of peri-graft drainage more than twice (n= 3) and positive culture of graft preservation solution (n= 5).All patients received tigecycline plus prolonged high-dose meropenem infusion-based antibiotics .Results Five patients with CRKP positive in preservation solution were successfully prevented from infection after a treatment period of (12 .4 ± 2 .1)days .Among another 8 cases ,additional topical medications (n= 3) and surgical debridement (n= 1) were used .It took a median time of 16 (7～60) days until a negative culture and the total antibiotic treatment course was 20 (10～93) days .The average hospitalization duration was (50 ± 35) days .During a median follow-up period of 25 (6～28) months ,there was no onset of renal arterial rupture ,graft nephrectomy or death .The survival rate was 100％ for recipients and 92 .3％ for grafts .Conclusions For post-transplant infections due to graft-carried KPC-2 producing CRKP ,rapid diagnostics and tigecycline plus prolonged high-dose meropenem infusion may optimize clinical outcomes by decreasing the rate of graft nephrectomy and the recipient mortality .