ABSTRACT
Objective To analyze human gait stability by acceleration signal at the head and lumbar under different walking conditions, and make comparison with parameters by the traditional COM (center of mass)-COP(center of pressure) method, so as to discuss the reliability of applying wearable sensors to analyze human gait stability. Methods The harmonic ratio (HR) parameter at the head and lumbar based on acceleration signal was applied to analyze gait stability of 18 healthy young adults under 3 walking conditions (footwear normal walking, barefoot normal walking and barefoot walking at different velocities), and the results were compared with the assessment results from the COM-COP method. Results Walking at normal velocity was most stable, with the maximum HR parameter. Compared with footwear walking, HR parameters were significantly decreased (P＜0.05) during barefoot walking, indicating that gait stability was reduced. The results were consistent with the assessment results from the COM-COP method. Considering the factors of walking velocity and footwear, the gait stability parameters obtained by the two methods showed a significant negative linear correlation (R2＞0.50). Lumbar HR parameter and COM-COP parameters showed a stronger linear correlation (R2＞0.65). Conclusions The application of acceleration signal-based analysis algorithm could effectively and reliably evaluate the stability of human gait, and acceleration at the lumbar was more sensitive than the head signal for analyzing gait stability.
ABSTRACT
Objective To observe the mRNA expressions of endothelin-1(ET-1) and endothelin A/B receptors (ETA/B) in tissue of benign prostatic hyperplasia treated by daily low-dose sildenafil.Methods A total of 32 patients with benign prostatic hyperplasia were randomly divided into two groups:treatment(25 mg sildenafi for 12 weeks,n=16) and control (no drug,n=16) groups.Immunohistochemical staining,ELISA and RT-PCR were used to detect the expression levels of ET-1 protein and ET A/B mRNA,respectively.Results The expressions of ET-1 protein and ET A/B mRNA in prostatic tissue were significantly lower in treatment group than in control group[(53.31±18.56) ng/kg vs.(83.34±31.38) ng/kg,0.356±0.056 vs.0.624±0.083,0.721±0.083 vs.0.933±0.905,t=-3.295,10.715,6.937,all P＜0.001].Conclusions Daily low-dose sildenafil can reduce the expressions of ET-1 and ET A/B receptors mRNA in benign prostatic hyperplasia.
ABSTRACT
Objective To study the damage focused ultrasound inflicts on the membrane permeability of Ehrlich ascitic tumor (EAC) cells and the relationship between changes in membrane permeability and focused ultra-sound exposure time. Methods The relative survival rate of tumor cells was examined at various intensities and dif-ferent exposure times using focused 2.2 MHz ultrasound. The uhrastructure changes were evaluated with a scanning electron microscope after different exposures. Membrane permeability was investigated by incorporating fluorescein isothiocyanate dextran (FD5OO) , and membrane damage was evaluated by measuring lactate dehydrogenase (LDH) release. Results Morphological observation showed there were numerous microvilli on the surface of un-exposed cells. When the cells had been irradiated with focused ultrasound for 30 s there was only a slight effect on the shape of the cells and the number of microvilli was slightly reduced. When the cells were exposed to ultrasound for 60 s, the surface of many cells became relatively smooth with no obvious microvilli, and several small craters were seen on the surfaces of cells where the cytoplasm seemed to have extruded through the membrane. The cell membrane was seri-ously damaged by sonoporation. The loading of FD500 in the unexposed cells was only 0.21%. When the cells had been sonicated with focused ultrasound for 30 s or 60 s, the loading of FD500 increased to 11.46% and 18.50% re-spectively. The released LDH activities in the 30 s group and 60 s group were 2.94±0.02 and 3.28±0.04 U/L, respectively. The activities of LDH increaased as the focused ultrasound exposure time was prolonged. Conclusion Focused ultrasound may damage the cell membrane permeability of EAC cells, and the damage increases as the expo-sure time is prolonged from 30 s to 60 s.