Experiment of nanobubbles-mediated plasmid green fluorescent protein(GFP) transfer into skeletal muscle in mice / 中华超声影像学杂志

ObjectiveTo explore the effect of nanoscale bubbles transfering gene in skeletal muscle cells in mice.MethodsPlasmid DNA encoding green fluorescent protein (GFP) was mixed with bubbles dissolved in saline and injected into the tibialis anterior (TA) muscle of C57B10 mice with and without ultrasound (US).The ultrasound frequency was 1 MHz and the pulse repetition frequency was 100 Hz with 20％ duty cycle.The spatial peak temporal peak intensity (ISPTP) power level was 2 W/cm2.The entire treatment period was 30 seconds.The efficiencies of GFP transgene expression were determined under different experinmental conditions.Mice were sacrificed 1 week after plasmid DNA injection.Fibres with fluorescence green signals were determined as GFP-positive fibres by fluorescence microscopy.Readout was performed on the section with the maximum number of transfected fibers.Results1 )Albumin nanobubbles:in the conditon of with or without ultrasound,albumin nanobubbles had significantly increased gene expression compared with negative control (P ＜0.05),but significantly decreased gene expression compared with positive control ( P ＜ 0.05 ).2) Phospholipid nanobubbles:In the conditon of without ultrasound,there were no significant differences compared with negative and positive control ( P ＞0.05).In the conditon of with ultrasound,phospholipid nanobubbles had significantly increased gene expression compared with negative control ( P ＜0.05).No significant difference was observed between phospholipid nanobubbles and positive control ( P ＞ 0.05).ConclusionsNanobubbles could enhance gene transfection efficiency for skeletal muscle fibres in mice.Nanobubbles with perfluoropropane gas and albumin have potentiality in gene-enhanced transfection.

The experiment in the mechanisms of microbubble-mediated GFP gene enhancement in skeletal muscle in C57B10/mdx mice / 中华超声影像学杂志

Objective To investigate the role of sonoporation and the deblic of microbubbles with perfluoropropane gas and albumin in the mechanisms of microbubble-mediated gene enhancement by experimenting in skeletal muscle in C57B10/mdx mice. Methods Plasmid DNA (10 μg) encoding green fluorescent protein (GFP) was mixed with Optison or SonoVue dissolved in saline and injected into the tibialis anterior (TA) muscle of /C57B10/mdx mice with and without adjunct ultrasound. The efficiencies of GFP transgene expression were determined under different experimental conditions. C57B10 mice as normal control:①C57B10 mice + saline (4 left TAs);②C57B10 mice + saline + ultrasound (4 right TAs) ;③C57B10 mice + Optison(4 left TAs);④C57B10 mice+ Optison + ultrasound(4 right TAs);⑤ C57B10 mice + SonoVue(4 left TAs) ;⑥C57B10 mice + SonoVue + ultrasound(4 right TAs). Mdx mice groups:① mdx mice + saline(4 left TAs) ;② mdx mice + saline + ultrasound(4 right TAs);③ mdx mice + Optison (4 left TAs) ; ④ mdx mice + Optison + ultrasound (4 right TAs); ⑤mdx mice + SonoVue(4 left TAs) ;⑥mdx mice + SonoVue + ultrasound(4 right TAs). Mice were sacrificed 1 week after plasmid DNA injection. Fibres with fluorescence green signals were determined as GFP-positive fibres by fluorescence microscopy. Readout was performed on the section with the maximum number of transfected fibers. Results C57B10 mice: ?Optison without ultrasound had significantly increased gene expression compared with negative control ( P <0. 01). SonoVue without ultrasound did not enhance gene expression. ?Optison with ultrasound had significantly increased gene expression compared with negative control (P < 0.01). ?SonoVue with ultrasound had significantly increased gene expression compared with negative control ( P<0. 01).Mdx mice:? Compared with C57B10 mice, GFP alone demonstrated significant GFP expression in mdx mice ( P <0. 01) , Optison demonstrated significant GFP expression in mdx mice ( P <0.01), and SonoVue demonstrated significant GFP expression in mdx mice ( P <0. 01). ?Microbubble groups (Optison and SonoVue) had significantly increased gene expression compared with negative control (P <0. 01). Conclusions In the mechanisms of microbubble-mediated gene enhancement, sonoporation is the key step. The deblic of microbubbles with perfluoropropane gas and albumin is the main constituent in the mechanisms of Optison-mediated gene enhancement. fibers.Results C5781 0 mice:①Optison without ultrasound had significantly increased gene expressioncompared with negative control(P<0.01).SonoVue without ultrasound did not enhance gene expression.②Optison with ultrasound had significantly increased gene expression compared with negative control(P<0.01).③SonoVue with ultrasound had significantly increased gene expression compared with negativecontr01(P

The implementation of speckle tracking imaging technology on functional assessment of regional myocardial contraction in patients with systemic lupus erythematosus / 中华风湿病学杂志

Objective To assess the vaIue of speckle tracking imaging (STI) in quantifying the regional myocardial strain in systemic lupus erythematosus (SLE) group.Methods ① Sixty subjects were divided into SLE group and normal group.High frame rate two-dimensional images were recorded from the apical two-chamber view,long-axis view and four-chamber view of the left ventricle (LV).Peak systolic strain of each view of 18 segments were measured by automated functional imaging (AFI) software of 2-DSE.All parameters were compared between the two groups.② Twenty cases were randomly taken from the normal group.The same observer at different times and two observers measure the strain of left ventricular respectively.The results of the measurement between the two groups were compared with unpaired t test and its relevance was analyzed using Pearson's correlation analysis.ResultsLeft ventricular two-dimensional longitudinal strain gradually increased from the base to apex in the normal group.There were statistically differences between the apical segments and the basal,middle segments of every left ventricular wall (P＜0.05).The same wall segment time to peak myocardial systolic peak strain was consistent.Left ventricular two-dimensional longitudinal strain gradually increased from the base to apex in the SLE group,except for the anterio-septal and anterior wall [ (-18.7±4.2)％,(-16.3±9.4)％,(-18.1±10.5)％ vs (-19.0±9.0)％,(-18.6±7.9)％,(-17.7±1.4)％ ].There was no statistically significant difference between the apical segments and the basal,middle segments of every left ventricular wall(P＞0.05).All parameters of S were significantly higher in the normal group than those of the SLE group.The difference was statistically signoficant (P＜0.05).The time to peak systolic peak strain of every segments was not consistent.The results from the same observer at different times and peak systolic myocardial strain measurements by the two observers were correlated well(P＜0.01).Conclusion The myocardial function assessment by STI technology in the SLE patients is significantly different from that of the normal control:SLE patients with left ventricular myocardial damage can be manifested as reduced regional myocardial systolic peak strain.

Hurst index based analysis of sinus arrhythmia and atrial arrhythmia / 生物医学工程学杂志

This study sought to disclose whether Hurst index can be used as a criterion for distinguishing sinus and atrial arrhythmia signals. Normal sinus rhythm beats, atrial premature contraction (APC) beats, and sinus bradycardia (SBR) signals, were taken from the MIT-BIH standard database. Hurst index method was used to distinguish the two kinds of arrhythmia. The results showed that the Hurst exponents of three kinds of signals were larger than 0.5, but they were in different value region. The data indicated that the long-term relevant character was the best for normal signal, better for sinus bradycardia, and the worst for atrial premature beats. So Hurst index is a useful identification criterion for distinguishing sinus and atrial arrhythmia signals.