10% at 24-hour later than the initial value.Conclusion In patients with refractory septic shock who achieved the goal of combiming CVP ≥ 8mmHg,MAP ≥ 65mmHg,SmVO2 ≥ 65% hyperlactemia was ameliorated.Lactate clearance rate can be used as a good marker to predict outcome of septic shock patients.

Objective To investigate the gene silencing,apoptosis induction and the suppression of proliferation in vivo transfected by UTMD techniques associated with shRNA techniques. Methods The survivin-shRNA expression vector was constructed. Nude mice were randomly arranged into 3 groups:control group, plasmid injection and ultrasound (P + US), P + UTMD group. Histological examination were evaluated. Protein expressions of Survivin and proliferating cell nuclear antigen (PCNA), Bcl-2, Bax,Caspase-3, Ki-67, nucleostemin (NS), p53 were investigated by immunohistochemistry. Results In transplanted tumors experiment, comparing with those in C and P + US groups, protein expressions of PCNA,Ki-67,Bcl-2, Survivin, NS were down-regulated markedly, while those of Bax, Caspase-3 and P53 were up-regulated significantly ( P ＜ 0.05). Conclusions UTMD combined with shRNA technique can induce apoptosis and inhibit proliferation significantly, without causing any apparently adverse effect,representing a new,promising technology that can be used in the tumor gene therapy and research.

Objective:To transfect genes using ultrasound targeted microbubble destruction (UTMD) techniques and observe the effects of RNA interference on cervical cancer (HeLa) cell line in silencing survivin gene and inducing apoptosis. Methods: Recombinant expression plasmid of short hairpin RNA (shRNA) targeting survivin gene was constructed. It was co-treated with microbubbles and transfected to cultured HeLa cells followed by exposure to ultrasound (P+UTMD group). Moreover, blank control group (C), plasmid group (P), ultrasound exposure group (US), plasmid and ultrasound exposure group (P+US), plasmid+ Lipofectamine group (P+L) were used as controls, respectively. Transfection efficacy was evaluated by observing the red fluorescence in the cells by fluorescent microscopy and flow cytometry(FCM). Ultrasound intensity and exposure time were optimized. Cell apoptosis was investigated using flow cytometry analysis, Hoechst staining, and DNA ladder method. Expression of survivin mRNA was assessed by RT-PCR. Results: Restrictive enzyme digestion and sequencing analysis verified that the recombinant plasmid was successfully constructed. UTMD significantly increased gene transfection efficacy in cultured HeLa cells (P<0.01). Gene transfer was the most prominent at ultrasound intensity of 1.0 W/cm2 and exposure time of 3 min (P<0.01). RT-PCR showed that the expression of survivin mRNA in P+UTMD group was inhibited by (83.33±2.73)%. The differences were significant compared with any other groups (P<0.01). FCM analysis showed that the apoptosis ratio in P+UTMD group was significantly increased as compared with other groups (P<0.01). Hoechst staining and DNA ladder showed that apparent apoptosis and DNA ladder were detected only in P+UTMD and P+L groups. Conclusions:UTMD effectively enhances the transfection efficacy of expression plasmid. It is a novel and effective non-viral gene transfer system and has promising foreground. UTMD mediates RNA interference silenced survivin gene and induces significant cell apoptosis, which provides a new method for tumor research and gene therapy.

Objective To investigate the relationship between end-tidal carbon dioxide with its related indicators and ventilation/perfusion of the acute respiratory distress syndrome (ARDS) lung,and to explore a feasible way to titrate positive end-expiratory pressure (PEEP) in clinical practice.Methods Five mixed-breed dogs with oleic acid lung injury model were mechanically ventilated at a serial PEEP trial including a recruitment maneuver (RM) before each PEEP level changed.The value of blood dynamics,end-tidal carbon dioxide partial pressure ( PetCO2 ) and arterial carbon dioxide pressure under different PEEP levels were recorded.Arterial end-tidal carbon dioxide gradient (Pa-etCO2) and dead space fraction (Vd/Vt％) were calculated.All dogs received CT scan.Lung volume under different pressure levels,and ratio and volume of alveolar closing pressure,collapsed alveoli,sufficiently and insufficiently ventilated alveoli were obtained.Alveolar opening and closing analysis were performed by non-liner regression equation.Results The mean pressure when Vd/Vt％ obtained lowest level were ( 11.2 ± 4.4 ) cm H2O(1 em H2 O =0.098 kPa),which had no significant difference when compared to alveolar closing pressure[ ( 11.5 ± 3.2 ) cm H2O ]( P ＞ 0.05 ).The fraction of insufficiently ventilated and collapsed alveoli showed a significant linear correlation with the Vd/Vt％ when PEEP was lower than Pmin ( r =0.632,P =0.004 ).There was a linear correlation between the Vd/Vt％ and the fraction of over-distended alveoli when PEEP was higher than Pmin ( r =0.770,P =0.001 ).Conclusions Closing pressure is in accordance with PEEP level after RM having reached the best ventilation/circulation ratio.The characteristics of lung collapse can be revealed by Vd/Vt％ changes after RM.To titrate PEEP for the lowest Vd/Vt％ after RM may be a feasible way to match the best ventilation and circulation effects of PEEP.

Objective To determine whether it could enhance gene delivery and tumor transfection in vivo by combination of ultrasound-targeted microbubble destruction(UTMD)with polyethylenimine(PEI)in tumor xenografts.Methods Two different reporter plasmid[lueiferase(pCMV-LUC)and red fluorescent protein(RFP)]were incubated with PEI to prepare cationic compound(PEI/DNA)in various nitrogen:phosphate ratios(N/P ratios,nmol of nitrogen in the PEI/nmol of phosphate in DNA).Formation of PEI/DNA complexes were confirmed by the gel retardation assay.Human cervical carcinoma(Hela)tumors were planted subcutaneously in both flanks of female nude mice.Tumor-bearing mice were administered by tail vein with PBS,plasmid,plasmid and Sono Vue microbubble,PEI/DNA and Sono Vue microbubble.One tumor was exposed to ultrasound irradiation (3 MHz,2 W/cm2,2 min exposure,duty cycle 20%),while the other served as control.The feasibility of targeted delivery and tissue specificity facilitated by UTMD and PEI was investigated.The mice were sacrificed 3 days after ultrasound exposure.Tissue specimens were viewed with microscopy to determine the presence of RFP expression.The efficiencies of luciferase transgene expression were determined.Histology analysis was detected.Results Electrophoresis experiment revealed that PEI was mixed with plasmid to condense DNA efficiently.The application of UTMD significantly increases the tissue transfection in vivo compared to plasmid alone.RFP expression was present in all sections of tumors that received ultrasound exposure but not in control tumors.Results of luciferase activity showed that the expression of luciferase was to be 14 times greater in ultrasound-exposed tumors(P＜0.01).More importantly,the increase in transgene expresgion was related to UTMD with the presence of PEI dramatically.At least 10-fold increase of luciferase gene transfer was obtained in irradiated tumors compared to non-irradiated controls(P＜0.01),111-fold increase compared to UTMD alone(P＜0.01).There was not significantly gene expression in other organs or tissues regardless of US exposure(P＞0.05).No tissue damage was seen histologically.Conclusions The combination of UTMD with PEI can enhance targeted delivery and expression of reporter gene to tumors at intravenous administration.It is a promising new and safe method for gene delivery in vivo.

Objective To investigate different ultrasound parameters and transfection conditions that would affect transfection rate of red fluorescent protein(RFP)and cell viability of cancer cells.Methods In this study,Hela cells were cultured using two different protocols:(A)24 h culture for complete adherence;(S)suspension.Subsequently,cells were transfected following different ultrasound exposure protocols[1.0W/cm2;duty cycle(DC):10%,20%and 50%;exposure 1min or 3 min].Gene transfection and cell viability were evaluated.Treatment parameters optimized in Hela cells were applied for delivery RFP in 4 other cell lines(HepG2,Ishikawa,MCF-7 and B16-F10).Results Cell injury were found to increase progressively with DC and exposure time in group A.Cell detachment was significantly accompanied by ultrasound exposure in adherent HeLa cells.Cells in group S were found more prone to be transfected than group A with the same ultrasound parameters,while the survival rate was not decreased apparently.The ideal ultrasound conditions were noted to be at 1.0 W/cm2 irradiated 3 min with 20%DC using suspended protocol,producing maximum efficiency[transfection=(28.04±2.27)%]in gene delivery with minimum cell toxicity[cell viability=(81.20±1.73)%].These experiments also revealed different response to ultrasound treatment,but for all tested cell lines,dead and transfected cells in the treated groups were significantly different from the non-irradiated groups.Conclusions Ultrasound parameters and transfection conditions have a great impact on the gene delivery and cell viability.Gene delivery of ultrasound-mediated microbubble enhance should be optimized to improve the efficiency.

Objective To study the optimized condition of transfection efficiency for MCF-7 cells enhanced by ultrasound(US) irradiation and contrast agent combined with polyethyleneimine(PEI) and observe whether the combination can have a synergistic effect to increase DNA transfection. Methods MCF-7 cells were transfected with the compounds prepared by the vector of plasmid DNA encoding luciferase (pCMV-luciferase-GL3) and PEI.SonoVue microbubble was added to the cell suspension to serve as nucleation sites for aeoustic cavitation before US irradiation. The DNA expression of luciferase plasmid and viability of cells were evaluated. The strategy of US irradiation was optimized. Furthermore, the influencing factor, such as the concentration of plasmid, incubation time, serum, the type of solvent and the volume of culture media, were examined. Results The viability of cells and US-induced enhancement of luciferase activity were influenced by the US intensity,exposure time and duty cycle.US irradiation under an appropriate condition enables ceils to accelerate the permeation of the PEI/DNA complex through the cell membrane, resulted in enhanced transfection efficiency of plasmid DNA. Optimal US condition for the enhancement was determined to be 1 W/cm2,10% DC for 3 min. In contrast to the PEI/DNA complex alone without US irradiation or US irradiation alone, the combination of US irradiation with contrast agent and PEI had a significantly enhanced luciferase activity (P<0.01). The 2 h pre-irradiation incubation with PEI/DNA complex for MCF-7 ceils exhibited a significantly enhanced lueiferase activity (P<0.01). Besides,serum,type of solvent and the volume of culture media did affect the transfection efficiency. Conclusions The optimized parameters of US and transfection provide efficient gene delivery in MCF-7 cancer cells. The combination of US irradiation with contrast agent and PEI has a synergistic effect to increase DNA transfection. This is a simple and promising method to enhance the gene expression of plasmid DNA.

Objective To investigate different pulsed ultrasound (PUS) parameters and culture conditionsthat would affect cell viability and sonoporation on cell membrane of human cervical cancer cells (HeLa). MethodsHeLa cells were cultured in two different conditions ( in suspension or in monolayer). Cells were exposed to differentPUS intensity (0.4 W/cm2, 1.0 W/cm2, 1.6 W/cm2, 2.2 W/cm2), duty cycle (10%, 20%, 50%) and expo-sure time ( 1 min or 3 min). Cell viability was analyzed by flow cytometry. Using microscope and scanning electronmicroscopy (SEM) , the changes of shape and the sonoporation on cell membrane induced by PUS were observed.Results Low intensity and duty cycle did not exert a great impact on the cell viability. Cell injury was found to in-crease progressively with high intensity ( 1.6 W/cm2 , 2.2 W/cm2 ) and duty cycle ( 50% ) ( P < 0. 01 ) , and celldetachment was significantly accompanied by PUS exposure in adherent HeLa cells. Results of factorial design showedthat the culture conditions and the PUS parameters had significant interaction ( P < 0.01 ). SEM demonstrated insome detail the phenomenon of transient pores in the cell membrane under suitable PUS irradiation. The ideal sonopo-ration conditions that cell viability was above 80% and more membrane holes were noted to be at 1.0 W/cm2 expo-sure for 3 min with a duty cycle of 20% in cell suspension. Conclusion The optimized conditions of the PUS pa-rameters and the culture conditions could lower the cell injury and exert a great impact on the sonoporation. It couldproduce remarkable membrane pores on cells and enhance cell membrane permeability, which facilitate transportationof macromolecules into cells.

Objective To study the transfeetion efficiency and safety of liposome microbubble(LM)on red fluorescent protein(RFP)in vitro and in vivo under ultrasound mediated gene transfection(USMGT)conditions.Methods Plasmids containing RFP were added to cultured Hela cells followed by ultrasound (US)exposure with LM.Different concentration of LM,US intensity and exposure time were optimized.Transfection efficiency was evaluated by fluorescent microscopy and FACS.Cell viability was verified by propidium iodide assay.In transplanted tumors in vivo study,LM and plasmid(P)were injected into the nude mice followed by US exposure(P+LM+US group).Nude mice undergoing plasmid injection alone(P group),plasmid injection and US exposure(P+US group)and plasmid and LM injection(P+LM group)were used as controls.Frozen section and histological examination were conducted and RFP expression was evaluated.Results LM and US exposure significantly increased transfeetion efficiency in cultured Hela cells (P＜ 0.01).Transfection efficiency was the most prominent under the condition of US intensity of 1.0 W/cm2 with 6%LM,duration 3 min.No apparent cell damage was found in the all groups.In transplanted tumors,strong RFP was seen in P+LM+US group.It was significantly higher than in any other groups(P＜0.0 1).No tissue damage was seen histologically.Conclusions LM could enhance USMGT effectively without causing any apparently adverse effect in vitro and in vivo.This method would be a novel,effective,safe non-viral gene transfection method and provide an alternative to current clinical gene therapy.

Objective To observe the changes of arm equilibrium pressure (Parm) in different occlusion time,the reference range of Parm in hemodynamic stable patients,and to explore the relationship between Parm and systemic hemodynamic parameters.Methods Mechanically ventilated postoperative abdominal surgery patients who admitted to ICU with stable hemodynamic status were enrolled.After hemodynamic data were recorded,arm stop-flow maneuvers were performed to measure Parm.At 10,20,30,40,50,60 seconds after occlusion,arterial pressure were measured twice within 5 minutes and recorded as the average value.Results Thirty patients were included.The Parm decreased gradually with the prolongation of the occlusion time.The value was not stable within 60 s,but the reducing extent was not obvious after 40s.The 95％ reference range of Parm 30 S was 23-44 mmHg(1 mmHg =0.133 kPa) and Parm 60 S was 19--35 mmHg.Parm at 30 s and 60 s were positively correlated with systolic arterial pressure,diastolic arterial pressure,mean arterial pressure,central venous pressure (all P ＜ 0.001),but not heart rate and pulse pressure.Linear regression analysis showed that Parm at 10 s,20 s,30 s only had linear correlation with diastolic arterial pressure (10 s,β =0.504,P =0.001;20 s,β =0.297,P =0.005;30 s,β =0.231,P =0.015),and Parm at 40 s,50 s,60 s were linear correlation with diastolic arterial pressure (40 s,β =0.220,P =0.004;50 s,β =0.210,P =0.004;60 s,β =0.213,P =0.004) and central venous pressure (40 s,β =0.516,P =0.018;50 s,β =0.513,P =0.01;60 s,β =0.472,P =0.023).Conclusion In mechanically ventilated postoperative abdominal surgery patients with stable hemodynamic status,Parm decreases when occlusion time is prolonged,which is not stable within 60 s occlusion.Arterial blood pressure and central venous pressure are positively correlated with Parm.