ObjectiveTo evaluate myocardial segmental motion function in left ventricular of patients with rheumatic mitral stenosis by using the technology of real-time three-dimensional echocardiography (RT-3DE). MethodsWe retrospectively analyzed the clinical data of 14 patients with rheumatic mitral stenosis between October and November 2014 in our hospital as a trial group. There were 4 males and 10 females with a mean age of 50.9±9.0 years ranging from 34 to 64 years. We chose 11 healthy individuals as a control group. There were 7 males and 4 females with a mean age of 49.5±9.7 years ranging from 32 to 67 years. Both the two groups were subjected to myocardial performance evaluation using two-dimensional echocardiography (2DE) and real-time three-dimensional echocardiography (RT-3DE) to examine the left ventricular ejection fraction (LVEF), left ventricular end-diastolic volume (LVEDV), left ventricular end systolic volume (LVESV), longitudinal strain, circumferential strain, area strain, and lateral strain of each left ventricular myocardial segments. Result RT-3DE detected that the trial group had significantly lower values of LVEF, LVEDV and LVESV than those of the control group (P < 0.05). RT-3DE also revealed that the trial group had a significantly weaker longitudinal strain than the control group (P < 0.05). ConclusionRT-3DE is an accurate technology for assessing myocardial motion and function in patients with rheumatic mitral valve disease.
ObjectiveTo establish multidrugresistance cell substrain of human hepatocellular carcinoma and to investigate its characteristics.MethodsSMMC7721 cell strain was cultured in Adriamycin(ADM). The multidrugresistance cell substrain SMMC7721/ADM was harvested after a long period of culture by gradually increasing the concentration of ADM and its characteristics were investigated. Results①The drug resistance of SMMC7721/ADM to ADM increased by 33.3 times, to Vincristine 16.8 times, to Diamminedichloroplatinum 2.8 times. ②The drug resistance cell substrain had almost the same growth velocity as its parental generation. The doubling time was 32.0 hours and 30.5 hours respectively. They had the analogous growth curves. ③The obvious difference between the drug resistance cell substrain and its parental generation was that the former’s microvilli became thick, short and scattered by scanning and transmitting electron microscopy. ④The multidrug resistance cell substrain kept the characteristics of hepatocellular carcinoma, it could be transplanted into the subcutaneous tissue of nude mice. ⑤The drug resistance of the cell substrain reduced to 28.0% and 9.2%after removal of the drug for 1 month and 2 months respectively, its drug resistance could remain stable (35.4 times) after 2 months of culture in ADM (0.04 μg/ml).ConclusionThe SMMC7721/ADM cell substrain has the stable fundamental characteristics of a drug resistance cell strain.
The purpose of this study was to investigate the effect of biaxial tensile strain on the osteogenic differentiation of rat bone marrow mesenchymal stem cells (rBMSCs) in vitro. The rBMSCs were isolated from tibia and femur of 4 weeks-old Sprague-Dawley (SD) rats. The rBMSCs were cultured in DMEM-LG complete culture medium and grew to subconfluence in the cell culture device for loading tensile strain. The biaxial tensile strain was applied to the rBMSCs for periods of 2, 4 and 6 hours every day, respectively, lasting 3 days. The amplitude of biaxial tensile strain applied to the rBMSCs were 1%, 2% and 5% respectively, at a frequency of 1 Hz. Unstrained rBMSCs were used as blank control (control group). The rBMSCs cultured with DMEM-LG complete culture medium containing 100 nmol/L β-Estradiol (E2) were used as positive control. The mRNA expression of alkaline phosphatase (ALP), collagen typeⅠ (ColⅠ), Runt-related transcription factor 2 (Runx2) and osteocalcin (OCN) was examined with real-time quantitative PCR and the protein expression of ALP, ColⅠ, Runx2 and OCN was detected with Western blot method. The results showed as follws: (1) The mRNA and protein expression of the ALP, ColⅠ, Runx2, OCN were significantly higher in rBMSCs of the E2 group than those in the control group (P＜0.05). (2) The mRNA and protein expression level of the ALP, Runx2 were higher markedly in the 1% tensile strain groups than those in the control group (P＜0.05), but lower than those in the E2 group (P＜0.05). (3) The mRNA and protein expression level of the ALP, ColⅠ, Runx2, OCN were significantly higher in the 2% tensile strain groups than those in the control group (P＜0.05), and the mRNA and protein expression level of ColⅠ and Runx2 in the group applied with 2% amplitude of tensile strain for 4 h/d was significantly higher than those in E2 group (P＜0.05). (4) The mRNA and protein expression level of the ALP, ColⅠ, Runx2 were significantly higher in the groups applied with 5% amplitude of tensile strain for 2 h/d or for 4 h/d than those in the control group (P＜0.05). In our study, E2 and mechanical stimulation played an important role in the regulation of differentiation of rBMSCs into osteoblasts, and the manner applied with the 2% amplitude of tensile strain for 4 h/d, lasting 3 days was an optimal stimulus for up-regulating the mRNA and protein expression of ALP, ColⅠ, Runx2, OCN of rBMSCs.
We aimed to establish an optical coherence tomography (OCT) system to measure the strain of blood vessels. A general OCT system was constructed firstly and its reliability was confirmed by comparing the OCT imaging of the porcine coronary and the corresponding histological slices. The strain of the porcine coronary was induced by static flow pressure and correlation algorithm was used to calculate the strain field of blood vessels within OCT images. The results suggest that bright-dark stratification of blood vessels displayed in OCT images is consistent with the intima and media layers of histological image. Furthermore, the strain of media layer is greater than that of the intima layer under the same static pressure. The optical coherence imaging system could not only measure the histological structure of the blood vessels, but also qualify the vessel strain under flow pressure.
Abstract： Objective To use tissue Doppler strain rate imaging to evaluate the impact of low dose dopamine and milrinone on systolic and diastolic function of the left ventricle of patients undergoing heart valve replacement. Methods Forty patients undergoing selective heart valve replacement in West China Hospital of Sichuan University between March and May 2011 were included in this study. All the patients were randomized into 2 groups with 20 patients in each group： milrione group and dopamine group. After anesthesia induction and before cardiopulmonary bypass setup， left ventricular ejection fraction （LVEF） was measured by echocardiography. Tissue Doppler strain rate imaging was used to measure the left ventricular lateral wall and midventricular segment from the four-chamber view， which was compared with Doppler parameters. Results LVEF， ratio of early-diastolic to end-diastolic velocity （E/A） of transmitral flow， ratio of mitral inflow velocity to early diastolic velocity in the annulus （E/Et） of both 2 groups were significantly different between before and after dopamine and milrinone administration （P＜0. 05）. In the milrinone group， 4 segments systolic peak velocity （Vs）， 1 segment early diastolic peak velocity （Ve）， 4 segments late diastolic peak velocity （Va）， 3 segments Ve/Va ratio， 2 segments systolic peak strain rate （SRs）， 2 segments late diastolic peak strain rate （SRa）， and 3 segments early diastolic peak strain rate SRe/SRa ratio after dopamine and milrinone administration were significantly higher than those before dopamine and milrinone administration （P＜0. 05）. In the dopamine group， 4 segments systolic peak velocity （Vs）， 1 segment Ve， 4 segments Va， 1 segment Ve/Va ratio， 2 segments SRs， 1 segment SRe， 1 segment SRa， and 1 segment SRe/SRa ratio after dopamine and milrinone administration were significantly higher than those before dopamine and milrinone administration （P＜0.05）. To compare the milrione group and dopamine group after medication administration， 2 segments Vs， 4 segments Va， 1 segment SRe， 1 segment SRa， 2 segments Ve/Va ratio， and 2 segments SRe/SRa ratio of the milrione group were significantly higher than those of the dopamine group （P＜0.05）， and 1 segment Vs， two segments SRs of the milrione group were significantly lower than those of the dopamine group （P＜0.05）. Conclusion Both milrinone and dopamine can improve left ventricular systolic function of perioperative patients undergoing heart valve replacement assessed by tissue Doppler strain rate imaging， while milrinone can improve the diastolic function of the left ventricle on the long axis more significantly.
Aiming at the disadvantages of traditional direct aperture optimization (DAO) method, such as slow convergence rate, prone to stagnation and weak global searching ability, a gradient-based direct aperture optimization (GDAO) is proposed. In this work, two different optimization methods are used to optimize the shapes and the weights of the apertures. Firstly, in order to improve the validity of the aperture shapes optimization of each search, the traditional simulated annealing (SA) algorithm is improved, the gradient is introduced to the algorithm. The shapes of the apertures are optimized by the gradient based SA method. At the same time, the constraints between the leaves of multileaf collimator (MLC) have been fully considered, the optimized aperture shapes are meeting the requirements of clinical radiation therapy. After that, the weights of the apertures are optimized by the limited-memory BFGS for bound-constrained (L-BFGS-B) algorithm, which is simple in calculation, fast in convergence rate, and suitable for solving large scale constrained optimization. Compared with the traditional SA algorithm, the time cost of this program decreased by 15.90%; the minimum dose for the planning target volume was improved by 0.29%, the highest dose for the planning target volume was reduced by 0.45%; the highest dose for the bladder and rectum, which are the organs at risk, decreased by 0.25% and 0.09%, respectively. The results of experiment show that the new algorithm can produce highly efficient treatment planning a short time and can be used in clinical practice.
Constrained spherical deconvolution can quantify white matter fiber orientation distribution information from diffusion magnetic resonance imaging data. But this method is only applicable to single shell diffusion magnetic resonance imaging data and will provide wrong fiber orientation information in white matter tissue which contains isotropic diffusion signals. To solve these problems, this paper proposes a constrained spherical deconvolution method based on multi-model response function. Multi-shell data can improve the stability of fiber orientation, and multi-model response function can attenuate isotropic diffusion signals in white matter, providing more accurate fiber orientation information. Synthetic data and real brain data from public database were used to verify the effectiveness of this algorithm. The results demonstrate that the proposed algorithm can attenuate isotropic diffusion signals in white matter and overcome the influence of partial volume effect on fiber direction estimation, thus estimate fiber direction more accurately. The reconstructed fiber direction distribution is stable, the false peaks are less, and the recognition ability of cross fiber is stronger, which lays a foundation for the further research of fiber bundle tracking technology.
The requirement for unconstrained monitoring of heartbeat during sleep is increasing, but the current detection devices can not meet the requirements of convenience and accuracy. This study designed an unconstrained ballistocardiogram (BCG) detection system using acceleration sensor and developed a heart rate extraction algorithm. BCG is a directional signal which is stronger and less affected by respiratory movements along spine direction than in other directions. In order to measure the BCG signal along spine direction during sleep, a 3-axis acceleration sensor was fixed on the bed to collect the vibration signals caused by heartbeat. An approximate frequency range was firstly assumed by frequency analysis to the BCG signals and segmental filtering was conducted to the original vibration signals within the frequency range. Secondly, to identify the true BCG waveform, the accurate frequency band was obtained by comparison with the theoretical waveform. The J waves were detected by BCG energy waveform and an adaptive threshold method was proposed to extract heart rates by using the information of both amplitude and period. The accuracy and robustness of the BCG detection system proposed and the algorithm developed in this study were confirmed by comparison with electrocardiogram (ECG). The test results of 30 subjects showed a high average accuracy of 99.21% to demonstrate the feasibility of the unconstrained BCG detection method based on vibration acceleration.
Quantitative measurement of strain distribution of arterial vessel walls due to pulsatile blood flow within the vascular lumen is valuable for evaluating the elasticity of arterial wall and predicting the evolution of plaques. The present paper shows that the three-dimensional (3D) strain distribution are estimated through uni-directional coupling for 3D vessel and blood models reconstructed from intravascular ultrasound (IVUS) images with the computational fluid dynamics (CFD) numerical simulation technique. The morphology of vessel wall and plaques as well as strain distribution can be visually displayed with pseudo-color coding.
ObjectiveTo explore the value of ultrasound real-time tissue elastography in the differential diagnosis between benign and malignant breast lesions.Methods A total of 131 cases of patients with breast lesions who underwent ultrasound examination in the People’s Hospital of Guangan City between December 2010 and December 2015 were enrolled as the research object. The patients took conventional color Doppler ultrasound diagnosis firstly, and then took ultrasound real-time tissue elastography diagnosis. The lesions were scored with improved 5-scoring system respectively. By the strain ratio measure method equipped with the ultrasonic machine, strain ratio of the lesion was calculated, with 3.08 as the cut-off pont. The results were campared with the pathologic diagnosis.ResultsThere were 182 breast lumps in the 131 patients. The conventional ultrasound examination detected 128 benign lesions and 54 malignant lesions. By ultrasound real-time tissue elastography examination, there were 121 benign tumors and 61 malignant tumors. For the benign tumors, the elasticity imaging score was 1.74±0.81, and the elastic strain rate ratio was 1.83±1.22; for the malignant tumors, the elasticity imaging score was 4.45±0.59, and the elastic strain rate ratio was 8.68±5.58. The 182 breast lumps were all removed by surgical resection, and the pathologic examination showed there were 121 benign lesions and 61 malignant lesions. The accuracy, sensitivity and specificity of conventional ultrasonic diagnosis of breast malignant lesions was 76.4%, 59.0% and 85.1%, respectively; while the indexes of ultrasound real-time tissue elastography diagnosis of breast malignant lesions was 96.7%, 95.1% and 97.5%, respectively, and the differences were statistically significant (P<0.05).ConclusionReal-time tissue elastography is helpful in the differential diagnosis between malignant and benign breast lesions.