Objective To study the sub chronic toxicity of silver nanoparticles on medaka.Methods Adult fish were divided into silve nenopartides and control group.Animals were collected on 14 days after exposure, and some toxicological endpoints such as death rate, tissue distributed of silver irons, oxidative stress and histopathological damage were measured.Results There were significant difference in death rate of medaka treated with silver nanoparticles and control group.Compared with the control group, the content of silver in gill, intestine and liver of medaka treated with silver nanoparticles were increased significantly.Compared with control group, the activity of LDH in liver and SOD in liver and gill were significantly decreased(P<0.01).The content of MDA in liver of medaka treated with silver nanoparticles was significantly increased(P<0.01).The liver and gill of mekada treated with silver nanoparticles were damaged, compared with control group.Conclusion Nano silver has a certain subchronic toxicity to aquatic life.

Objective To study the early diagnosis and management of the patients with acute respiratory distress syndrome (ARDS) caused by cytomegalovirus (CMV) pneumonia after liver transplantation.Methods The clinical data of 8 patients with ARDS caused by CMV pneumonia after liver transplantation in our hospital from April 2001 to May 2004 was retrospectively analyzed. All cases were treated with intravenous infusion of gancyclovir, reduced dosage of cyclosporine A or tacrolimus to 1/3~1/2 of baseline and withdrawal of MMF and prednisone. The patients were subjected to breathing machine assist ventilation and nutrition supply.Results Five patients recovered and 3 died. No one developed acute rejection. Conclusions The key of early diagnosis lies in combining chest X-ray or CT scan with clinical presentation. Administration with anti-viral drugs, adjustment of immunosuppressive agents, management with breathing machine assist ventilation and effective nutrition supply are important for the treatment of patients with ARDS caused by CMV pneumonia after liver transplantation.

Objective To determine the optimal cut-off value of critical-care pain observation tool (CPOT) in assessing degree of pain in patients undergone craniotomy, and to determine the sensitivity and specificity of CPOT with this cut-off value. Methods A prospective observational study was conducted in Beijing Tiantan Hospital. A total of 118 patients admitted to intensive care unit (ICU) after craniotomy was consecutively enrolled during August 2014 to August 2015. CPOT and visual analogue scale (VAS) were used to assess the pain before, during and 20 minutes after the removal of central venous catheters, and the difference was compared between two scores at three time points. Receiver operating characteristic (ROC) curve was used to determine the optimal cut-off values for evaluation of the sensitivity and specificity of CPOT. Patients' complaint of pain was considered the gold-standard. Results CPOT values (inter-quartile range) before, during and after the procedure were 0 (0-3), 0 (0-6) and 0 (0-2), respectively; while VAS values were 4 (1, 6), 3 (1, 6) and 4 (1, 6), respectively. CPOT value during the procedure was significantly higher than CPOT values before and after the procedure (both P < 0.01). When the optimal cut-off value of CPOT was 1, CPOT showed the highest Youden index before, during and after the procedure (1.183, 1.515, and 1.438, respectively), and showed high specificity (all 100%) and low sensitivity (18.3% and 43.8%, respectively) when assessing the pain before and after the removal of the catheter. The sensitivity and the specificity were high when assessing the pain during the procedure, the sensitivity was 69.4%, and the specificity was 82.1%. When the optimal cut-off value of VAS was 2 before and during the procedure, and was 4 after the procedure, VAS showed the highest Youden index, 1.568, 1.452, and 1.509, respectively. VAS demonstrated high sensitivity and specificity before, during and after the procedure (sensitivity was 97.2%, 95.2% and 75.0%, respectively; specificity was 59.6%, 50.0% and 75.9%, respectively). The area under ROC curve (AUC) of CPOT before, during and after the procedure were 0.592 [95% confidence interval (95%CI) = 0.490-0.693], 0.778 (95%CI= 0.693-0.863) and 0.719 (95%CI = 0.627-0.811), respectively; the AUC of VAS before, during and after the procedure were 0.846 (95%CI = 0.771-0.920), 0.767 (95%CI = 0.681-0.854) and 0.838 (95%CI = 0.767-0.909), respectively. The AUC of VAS before and after the procedure was significantly higher than the AUC of CPOT (P < 0.001 and P = 0.006), while there was no significant difference between the AUC of VAS and CPOT during the procedure (P = 0.826). Conclusion CPOT can be used to assess the pain during painful procedure, and it shows high accuracy, but with poor evaluation effect on pain in rest.

BACKGROUND:The hyperpoladzation-activated cyclic nucleotide-gated cation channel (HCN) gene is not increase the risk of induced cardiac arrhythmia,and can accept the modulation function of autonomic nervous system.Therefore,it is the first candidate gene for biological pacemakers.OBJECTIVE:To construct recombinant adenovirus vector containing human HCN4 gene and evaluate its transfection efficency in rat bone marrow mesenchymal stem cells (MSCs).DESIGN,TIME AND SETTING:The in vitro cytology-gene experiment was performed at the Lin Bai-xin Experimental Center,Second Hospital of Sun Yat-sen University from February to September 2008.MATERIALS:Ten SD rats were supplied by the experimental animal center of Sun Yat-sen University.Rlasmid pcDNA3.1-HCN4 containing target gene human HCN4,human embryo kidney 293 cells and Escherichia coll DH5α were preserved by our experimental center;Shuttle plasmid pShuttle-CMV containing green fluorescent protein gene and adenoviral backbone plasmid pAdxsi were bought from SinoGenoMax Co.,Ltd.METHODS:HCN4 cDNA segment was liberated from the cloning vector of pcDNA3.1-HCN4 via Hind Ⅲ+Xba Ⅰ,and subcloned into pShuttle-CMV,which was digested by I-Ceu Ⅰ +I-Sce Ⅰ double enzyme and subcloned into adenoviral plasmid to form recombinant adenovirus plasmid.Recombinant adenovirus plasmid was transfected into 293 cell lines by liposome,and the recombinant adenovirus AdHCN4 was packaged and transfected into rat MSCs.MAIN OUTCOME MEASURES:The identification of recombinant adenovirus plasmid vector,identification of recombinant adenovirus and its titration test;the transfection efficiency of recombinant adenovirus.RESULTS:Cloned sequence about 3.6kbp was obtained by Hind Ⅲ+Xho Ⅰ digestion after HCN4 cDNA segment was cloned into pShuttle-CMV.DNA sequencing results indicated that the clone location was correct.Recombinant adenovirus plasmid was cut into seven fragments while empty vector gained only six fragments after digested by Xho Ⅰ.The recombinant adenovirus was pathogenic to 293 cells after recombinant adenovirus plasmid was packaged in it.HCN4 cDNA (657bp) was amplified by PCR with virus titer of 2.5×10~(11) PFU/mL after transfected 293 cells with supematant.The efficiency of recombinant adenovirus infecting rat MSCs was about 90% when multiplicity of infection was 800.Rat MSCs expressed green fluorescence after transfection.CONCLUSION:The adenovirus vector with human HCN4 cDNA was established successfully,which can effectively transfect rat MSCs.

Total caudate lobectomy via anterior hepatic transection is still a new technique to resect the tumor in the caudate lobe,which is mastered only by few surgeons.The procedure was successfully performed on a 21-year old patient with focal nodular hyperplasia in caudate lobe.The right and left lobes were first mobilized,then the short hepatic veins were dissected to detach the caudate lobe from the retrohepatic vena cava.Then the liver was split anteriorly and the partial middle lobe was resected.With this process,the tumor was in the sight and we dissected it from the liver parenchyma.The inflow blood was occluded 3 times with a period of 29,27 and 27 minutes,respectively,with an interval of 5 minutes.The total blood loss during operation was 1000 ml.The patient recovered quickly without any complications.The technique for caudate lobectomy via anterior hepatic transection can improve the success rate and safety of caudate lobectomy and deserve clinical consideration.

Objective To evaluate the effectiveness of discharge planning and home care for patients with peritoneal dialysis (PD).Methods A total of 60 PD patients were randomly divided into the intervention group and control group,30 cases in each group.Discharge planning and home care were carried out in the intervention group, while routine nursing and telephone follow -up service after discharge were implemented in the control group.The patientsˊscores of Zung Self -Rating Anxiety Scale(SAS),Self -Rating Depression Scale(SDS),Self management ability of patients undergoing peritoneal dialysis,complication rate and readmission rate were compared between the two groups at the next day admission,discharge,lth month and 3th after discharge.Results The scores of SAS and SDS in the intervention group were significantly lower than that in the control group at 3th month after discharge,the difference was statistically significant(tSDS =5.263,tSAS =3.812,P <0.05).The Self management ability of patients undergoing peritoneal dialysis was significantly higher than that of the control group at lth and 3th month after discharge,the difference was statistically significant (t =6.845,t =7.231,P <0.05).No significant difference in the re -admission rate (16.67%,6.67%)was found between the two groups (χ2 =0.387,P >0.05).The complication rate in the intervention group was significantly lower than in the control group at 3th month after discharge(χ2 =5.124,P <0.05).Conclusion Discharge planning and home care can effectively relieve depression and anxiety in patients with peritoneal dialysis and improve the abilities of daily life.It is worth promoting and applying in clinic.

Objective To evaluate the feasibility of a low-dose contrast medium protocol for 64-slice CT angiography (CTA) of head using a low-tube-voltage setting.Methods ① Phantom study:64-slice spiral CT respectively sets 80,100,120,140 kV and 100,200,300,400,500 and 600 mA as scanning parameter lines.Analysis of the best Signal-to-noise ratios (SNR) and contrast to noise ratios (CNR).②Clinical study:to prospectively continuous select sixty-six patients with suspected intracranial aneurysm and arteriovenous malformation and so on from April to October of 2012 to perform hand CTA inspection.The random number table method for A,B two groups,33 patients in each group.Group A (conventional group)scanning parameters:120 kV,400 mA and amount of contrast agent:1 ml/kg; Group B(test group) scanning parameters:80 kV,600 mA,amount of contrast agent 0.5 ml/kg.Using independent samples t test for each group radiation dose,SNR,CNR were statistically analyzed.By two experienced radiologists to 5 points on two groups of image quality subjective evaluation.Mann-Whitney U test was used for statistical analysis of subjective evaluation.Results Group A and B group CTDIvol respectively is 59.1,27.5 mGy.Group B than in group A,CTDIvol decreased by 53.5％.A,B groups of the SNR,CNR were 71.5 ± 10.7,92.0 ± 7.4; 58.5 ± 10.5,79.6 ± 7.7,Group B than in group A SNR,CNR were enhanced by 22.3％,26.4％,differences were statistics significance (t =584.0,388.6,P ＜ 0.01).The subjective image evaluation of group B was bigher than group A (Z =31.2,23.4,P ＜ 0.05),differences were statistics significance.Two physicians on CTA images to assess the consistency of uniform height(Kappa =0.904,P ＜0.05).Conclusion In the head CTA examination,use of low tube voltage combined with low contrast dose not only can improve the image quality but also radiation dose were significantly lower.

Objective To probe the feasibility of gemstone spectral CT in imaging pulmonary angiography with low dose contrast medium.Methods A prospective study with multi-slice spiral CT pulmonary angiography was performed in consecutive 48 patients suspected with pulmonary embolism.Two groups (n=24 respectively)were divided at random including Group A used Gemstone spectral CT with 35 mL of contrast medium and Group B using 64-slice CT with conventional 80~90 mL of contrast medium.The CT values of the pulmonary trunk,lobe artery,pulmonary vein and ascending aorta were measured.The contrast to noise ratio of the pulmonary artery was also calculated.In addition,the image quality of CTA was evaluated independently by two experienced ra-diologists.Results The CT values of the pulmonary trunk and the subsegmental branches,and the CNR in Group A were signifi-cantly higher than those in group B,exhibiting statistical differences (t=8.6,P <0.001;t=12.2,P <0.001;t=1 1.3,P <0.001 respectively).However,the CT value of aorta in Group A was significantly lower than that in Group B (t=-7.6,P <0.001).The evaluation results of the CTA images by two radiologists showed that the image quality in Group A was better than that in Group B (Z =-8.6,P <0.001;Z =-9.0,P <0.001 ).Conclusion The image quality of pulmonary angiography with gemstone spectral CT using low contrast medium dose can be improved compared with the conventional spiral CT.

Objective To evaluate the differences in image quality and radiation dose in the neck CTA between low tube voltage scanning method combined with exact calculation of contrast dosage and conventional scanning methods.Methods Ninety patients who had undergone neck CTA examination from October 2012 to June 2013 were prospectively selected to perform study.Patients were randomly divided into Group A,B and C,each with 30 cases.Tube voltage and contrast amount were,respectively,120 kV and 70-80 ml for Group A (conventional group),100 kV and exact calculation for Group B,80 kV and exact calculation for Group C.Using ANOVA test,radiation dose,contrast amount,CNR were statistically analyzed among three groups.Subjective evaluations were made of image quality by two experienced radiologists based on a 5-point system.Results The effective doses in Group B and C were (4.5 ± 0.7) mSv and (2.1 ± 0.4) mSv,respectively,significantly lower than (6.6 ± 0.9) mSv in Group A,with statistically significant difference(F =72.4,P ＜ 0.05).The amounts of contrast were significantly lower in Group B and C than that in Group A,which respectively were (73.2 ± 8.2) ml for Group A and (48.2 ± 5.1) for Group B and (48.6 ± 5.4) ml for Group C,with statistically significant difference (F =56.8,P ＜ 0.05).CNRs increased respectively by 42.2％ in Group B and by 42.2％ in Group C compared with Group A,with statistically significant difference (F =72.6,P ＜ 0.05).Venous artifact images were found in 10 patients of Group A,having different effects on image quality,whereas in Group B and C,there were not vein artifacts to found.Conclusions The low tube voltage (80 kV) scanning method combined with exact calculation of contrast features not only significantly lower radiation dose and lower contrast amount used,but also improved image quality in comparison with conventional method.

Objective To develop a candidate reference method for the determination of serum creatinine and to evaluate the ac-curacy of conventional detection systems though method comparison to achieve traceability .Methods The candidate reference method was established according to the sarcosine oxidase and the accuracy and reliability of the method was verified through par-ticipation in international reference laboratories EQA activities (IFCC-RELA) .20 fresh single human serum samples with different concentration and calibrator were simultaneously measured by using conventional detection system and candidate reference method . Results The calibration curve for serum creatinine was linear in the concentration range from 50-2 000 μmol/L with a correlation coefficient of 0 .999 9 under the optimum experimental conditions (the linear equation was Y=0 .000 884 2X-0 .000 325 3) and the imprecision was less than 1 .0% .The proposed method has been applied to the determination of RELA samples with satisfactory re-sults .The measured results with conventional detection systems were consistent with candidate reference method ,and the slope of the regression equation was 1 .005 6 .Conclusion The candidate reference method of serum creatinine is successfully established and which can be used for traceability and standardization .It may provide an effective way for conventional detection system traceable to the reference method or reference material .