Objective To study the normal changes in brain during childhood by analyzing the diffusion characters of different regions and different age phases with diffusion tensor imaging (DTI). Methods DTI was performed in 63 children (age range, 2 days to 9 years) without brain abnormalities and the data measured in ADC maps were analyzed statistically. Results (1) There were significant differences in ADC values among some different regions of brain tissue; (2) In babyhood, the ADC values in gray matters decreased faster than in white matters; (3) The ADC values decreased with the increasing of age , and show negatively exponentially correlation with age. Conclusion DTI shows the changes of brain tissue composition in vivo, with which normal changes in brain during childhood can be evaluated.

Objective To study findings of the white matter of nomal children on color tensor map and evaluate the diffusion tensor imaging in the assessing development of the brain. Methods DTI was obtained in 89 normal children aging from 2 days to 18 years.Their color tensor maps were generated and analyzed.Results Their color tensor maps revealed different findings due to aging;with the increase of the age,the fiber tracts showed were more and well defined.Conclusion The color tensor map is superior to the routine MR in assessing the development of the white matter.

Objective To evaluate the diastolic function in patients with congestive heart failure (CHF) after cardiac resynchronization therapy (CRT) by conventional echocardiography or Doppler tissue imaging (TDI).Methods 31 patients with CHF were divided into responders to CRT (group R) and nonresponders to CRT (group N) according the standard of a decline in left ventricular(LV) end-systolic volume ≥10％.All the patients received echocardiography examination 1-3 days before CRT and 6 month after CRT.Color M-mode echocardiography indices included Vp,E/Vp.TDI indices included the peak velocity in early diastole (e) at 4 sites of mitral annulus,E/e,time to peak velocity in systole (Ts),Ts-SD and maximum difference of Ts (Ts-Dif) among 12 segments.Results Compared with before CRT,Ts-SD and Ts-Dif significantly shortened in group R;Vp increased significantly,E/e at each 4 site and mean value at 4 sites of mitral annulus,E/Vp decreased significantly; but there were no significant difference in group N.There were significant positive correlation between mean value at 4 sites of E/e,E/Vp and Ts-SD in group R.Conclusions The diastolic function in responders to CRT improved after CRT,which was associated with the decreased LV filling pressure and improved LV relaxation.

Objective To evaluate the right ventricular function in patients with congestive heart failure (CHF) after cardiac resynchronization therapy (CRT) by 2-dimensional speckle imaging (2D-STI).Methods 46 patients with CHF were divided into responders to CRT and non-responders to CRT according the standard of a decline in LV end-systolic volume ≥ 10％.All the patients received echocardiography examination 1-3 days before CRT and 6 month after CRT.Tissue Doppler imaging (TDI) indices included SD of time to peak velocity in systole (Ts-SD) among 12 segments.Right ventricular diameters included RV basal transverse diameter (D1),RV middle transverse diameter (D2) and RV longitudinal diameter (D3) in apical four views.2D-STI indices included systolic strain (S) and stain rate (SR) of basal or middle segment of RV free wall.Results Compared with before CRT,LVEDd,LVEDV,LVESV and Ts-SD significantly decreased,LVEF significantly increased in responders 6 months after CRT.Before CRT,compared with nonresponders,there was no significant difference of D1,D2 and D3 in responders,while S and SR in basal or middle segment of RV free wall were higher than non-responders.Compared with before CRT,D1,D2 and D3 in responders decreased significantly,S and SR in basal or middle segment of RV free wall increased significantly,while there was no difference in non-responders.There were significant negative correlation between S and SR in basal or middle segment of RV free wall and Ts-SD in responders.Conclusions The remodeling and systolic function of RV are improved after CRT.It may help for improving the efficacy of CRT when takes RV function data into account before CRT.

Objective To study the normal changes in brain white matter during childhood by analyzing the anisotropy of different regions and different age groups with diffusion tensor imaging (DTI). Methods DTI was performed in 89 children (age range from 2 days to 18 years) without brain abnormalities, and the data measured in fractional anisotropy(FA) maps were analyzed statistically. Children less than 6 months were ranged to group 1, 6-12 months to group 2, 1-3 years to group 3, 3-5 years to group 4, 5-8 years to group 5, 8-12 years to group 6, 12-18 years to group 7. Results (1) There were significant differences in anisotropy (FA values) among different regions of white matter in brain In group 7, the FA value of corpus callosum was 0.826?0.039, middle cerebellar peduncle 0.678?0.043, frontal white matter 0.489?0.033. (2) The anisotropy among different age group was statistically different, P

Objective To compare pediatric patients with periventricular leukomalacia (PVL) with normal children by using diffusion tensor MR imaging. Methods Diffusion tensor images were obtained in 15 pediatric patients with PVL and 15 age-matched normal children. Regions of interest were drawn to measure the fractional anisotropy (FA) in bilateral posterior limb of internal capsule, bilateral optic radiation, genu of corpus callosum, and splenium of corpus callosum. The values of PVL patients and normal children were compared using non-dependent samples T-test. Results The FA values of regions of interest prescribed were significantly lower in PVL patients than in normal children(P

Humans ; Occupational Health ; Workplace ; statistics & numerical data

Objective To increase the transfection of EGFP-N3 plasmids into 293T cells using ultrasound-targeted microbubbles delivery(UTMD) mediated a peptide nucleic acid (PNA) binding nuclear localization signal (NLS).Methods Antibody-targeted microbubbles were used in the experiments which can specifically recognize the SV40T antigen receptor.The SV40T antigen receptors were expressed on the membranes of 293T cells.The PNA containing the NLS were inserted in the EGFP-N3 plasmid DNA,which increased nuclear localization.Ultrasound-targeted microbubble delivery (UTMD) and the PNA binding NLS were utilized to improve the cytoplasmic import of plasmids and the nuclear intake of the plasmid from the cytoplasm,respectively.The study was divided into five groups:Contrast (group A),Common microbubble + DNA (group B),Antibody-targeted microbubbles + DNA (group C),Common microbubbles + NLS-PNA-DNA (group D),Antibody-targeted microbubbles + NLS-PNA-DNA (group E).Fluorescence microscope was used to observe the fluorescent light in each group;flow cytometry to test the transfection;RT-PCR and Western blot to detect genes' mRNA and protein expression level.Results Ultrasound and antibody-targeted microbubble delivery (UTMD) significantly enhanced the cytoplasmic intake of exogenous genes and maintained high cell viability(＞80％).Fluorescent microscope showed that the quantities of green fluorescence in cells were increased successfully.The transfection results of flow cytometry were 0,(9.30 ± 0.46)％,(26.46 ± 2.01)％,(29.54 ± 0.62)％,(45.72 ± 1.86)％,respectively,and the differences were statistically significant(P ＜0.05).The relative mRNA and protein expression in group E were greater than those in group C and D respectively (P ＜0.05).Conclusions UTMD combined with antibody-targeted microbubbles and a PNA binding NLS plasmid can significantly improve transfection efficiency of exogenous genes by enhancing both cytoplasmic and nuclear DNA import.

Objective To observe Meissner's corpuscles in prepuces of different shapes and ages. Methods The Meissner's corpuscles were detected with immunohistochemical stain in 204 prepuce sam- ples of different shapes and ages (3-59 years),and the density of Meissner's corpuscles in every sample was obtained as well.The difference of Meissner's corpuscle densities between phimosis and redundant pre- puce,and correlation between Meissner's corpuscle densities and ages were analyzed with Chi-square test and linear regression,respectively.Results The density of Meissner's corpuscles in redundant prepuce has begun to increase since infancy and reached the peak at the age about 15 years.No significant difference in densities of Meissner's corpuscles between phimosis and redundant prepuce was observed till the age of 20 years,and then there was a trend of disappearance of Meissner's corpuscles in redundant prepuce.A signifi- cantly negative correlation between the densities of Meissner's corpuscles and ages was revealed in redundant prepuce (r=-0.236,P=0.009),whereas an insignificantly positive correlation between the densities of Meissner's corpuscles and ages was shown in phimosis (r=0.193,P=0.084).Conclusions The den- sities of Meissner's corpuscles in redundant prepuce develop synchronically with genital differentiation and accord with the status of sexual function in adult males.The persistent high level of Meissner's corpuscles in adult phimosis might be a mechanism of physiological compensation.

Objective To observe the rate-adaptive response of dual sensor pacemakers integrated with activity sensor and minute ventilation sensor.Methods Fifty patients with chronotrepic incompetence were implanted with pacemakers of integrated sensor.The patients with pacemakers implanted were arranged to take upstairs test,downstairs test and tapping test under the monitor of integrated sensor,minute ventilation sensor and activity sensor respectirely.The rate-adaptive responses were tracked down every 15 seconds with remote heart rate monitor.The results were compared with the control group patients with normal sinal chronotropic function(n=15).Results In activity sensor group,pacing rates were significantly higher than the normal control group in downstairs test and tapping test.In minute ventilation sensor group,pacing rates increasement was significantly slower in the beginning of upstairs test.Pacing rates of integrated group were similar to the normal control group in upstairs and downstairs tests.Conclusion The rate-adaptive pacing response of dual sensor integrated with activity sensor and minute ventilation sensor,which is mostly close to the normal chronotropic response,better than that of single sensor.