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Four new polyhydroxylated steroids plaksterols A-D (1-4), together with two known related steroids ergost-7,9(11),22-trien-3β,5α,6α-triol (5) and ergosta-6β-methoxy-7,22-diene-3β,5α-diol (6), were isolated from methanol extract of the South China Sea marine sponge Plakortis sp. Their structures were identified by spectroscopic analysis, including NMR, MS, and IR. The cytotoxicity of the polyhydroxylated steroids were evaluated, and compound 6 showed moderate inhibitory activities against K562, HL-60 and BEL-7402 cells.
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Acquired heterotopic ossification is the abnormal bone formation outside of the normal skeletal system . The origin trauma and disease of aHO is plentiful .In this paper, we reviewed on BMP ,hedgehog,wnt/β-catenin and NF-κB signaling pathway , understanding of the pathogenesis of aHO .
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Objective Epidemiological studies have suggested that alcohol drinking is closely associated with di-verse tumor development, but fewer laboratory studies or mechanism analysis is made. Our study aims to explore the effect of alcohol on the tumorigenicity and metastasis of breast cancer in nude mice in vivo and on the malignant behavior in vitro, and whether it is related to endoplasmic reticulum stress ( ERS) . Methods We first established the nude mouse model of breast cancer with chronic alcohol consumption (2%) and to detect the effects of ethanol on tumor growth and metastasis. We also observed the changes of malignant biological behavior of EO771 cells in cell culture induced by chronic alcohol treatment (0. 2%) using MTT, Transwell and soft agar tests, and detect the expression of ROS and ERS marker, i. e. p?eIF2a, Bip, and XBP1?s. Results The in vivo experiment showed that alcohol drinking enhanced the growth and metasta?ses of breast cancer in nude mice. The in vitro test showed that chronic exposure to ethanol also promoted the cell prolifera?tion and migration ability, increased the ROS expression, activated ERS pathway, and enhanced the expression of p?eIF2a, Bip and XBP1?s. Conclusions Alcohol drinking may promote the malignant behavior of breast cancer cells through endo?plasmic reticulum stress.
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Objective To study the age-related changes in biomechanical properties of rabbit cornea by using the data from uniaxial extension testing on rabbit cornea strips. Methods To obtain the experiment data, the uniaxial extension test on rabbit cornea strips of both 3-month old and 7 to 8 month-old were performed. The exponential function model and power function model were used to fit the strain-stress curves, and two kinds of viscoelastic mechanical models were used to analyze the stress relaxation curves. Results The mechanical behavior of the rabbit cornea strip presented a nonlinear and viscoelastic property. Within the range of error permitting, the age was not an important factor to affect the stress-strain, as no significant difference was found in nonlinear stress-strain curve of rabbit cornea strips between different ages. The cornea strips of 7 to 8 month-old rabbit had a slightly bigger elastic modulus and a faster stress relaxation than those of 3 month-old one. Different stretching rates had no obvious influence on the nonlinear stress-strain of 3-month old rabbit cornea strips, but the cornea strips at high stretching rate could have a faster stress relaxation. Conclusions The tangent modulus of rabbit cornea increases slightly with age, but its relaxation properties would change greatly with age.
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Objective To establish a three-dimensional (3D) visualization model for the vessel system of rabbit eyes using X-ray phase contrast imaging（XPCI）technique, and observe the morphological characteristics of iris vessels of the rabbit eyes. Methods Angiography on vessels of the New Zealand rabbit eyes was conducted using Barium sulfate as the contrast medium. The projected images of in vitro rabbit eye samples with high precision were obtained by XPCI technique, and then converted to tomography images by filter back projection. The 3D reconstruction of the rabbit eyes was completed by commercial visualization software Amira 5.2.2. Results The main blood vessels of the rabbit eyes were clear and coherent in the projection images, and the distribution and trend of some small vessels could be observed, with the smallest distinguishable blood vessel diameter being about 10 μm. The 3D model for vessel network of the rabbit eyes was built after 3D reconstruction of CT scan images. The major arterial circle of the iris could be observed at level 4 branch structure of vessels in the fundus, and the minimum diameter of vessels that could be identified was 40 μm. Conclusions The vessels of the rabbit eyes can be clearly observed and 3D visualization of vessel network can be constructed by using XPCI technique, which would provide basis for the analysis on hemodynamics of blood vessels in the eye and reference for the clinical study of glaucoma.
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Objective To propose an inverse method for determining nonlinear mechanical properties of the blood vessel based on the results of experimental data and numerical simulation.Methods Pressure loading was applied on the blood vessel to obtain the experimental data of in vitro holistic blood vessel by using the self-designed device. The finite element model of vessel inflation was established by supposing that material characteristics of the blood vessel were in corresponding with the hyperelastic Ogden model. Mechanical properties of the blood vessel were then computed by the reverse method based on these experimental data and simulated results .Results The first-order and second-order Ogden material parameters of the rabbit abdominal aorta were identified, in which α=10.86±1.98 for the first-order Ogden material model. The mechanical properties of the rabbit abdominal aorta could be characterized as the hyperelastic material. Conclusions The inverse method based on the experimental measurement and numerical simulation can be used to identify the nonlinear mechanical properties of the blood vessel.
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Objective To investigate the clinic effect of hypocellular acute myelogenous leukemia (AML) patients with CAG regimen. Methods 29 cases with hypocellular AML were treated with CAG regimen. Results There were 14 cases achieved complete remission (CR), accounting for 48.3 %; 7 cases partial remission (PR), accounting for 24.1%. The total effective rate was 72.4 %, inducing 7 cases of NR, one case dead in early time. Conclusion CAG regimen has been proved to be effective in shortening the period of reduced peripheral blood granulocytes and decreasing the death rate related to chemotherapy, hence,a secure and effective therapy in treating hypocellular AML.
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Objective To obtain pressure-volume relatioship for the rabbit eye in vivo. Method Physiological salt solution was injected with the rate of 20 μL/min through the limbus to the anterior chamber of the rabbit eye for 100 min and the intraocular pressure (IOP) was recorded. Results The relationship between IOP and injection time could be fitted to a segmented function with a characteristic point called IOPg. The ocular rigidity coefficients before and after this IOPg were (4.02±0.86) mmH2O/μL and (2.43±0.94) mmH2O/μL, respectively (1 mmH2O=9.8 Pa), showing significant difference. Conclusions IOPg existed in all curves of IOP and injection time and the ocular rigidity coefficients were dependent on the injection rate and position of IOPg. Parameters of the fit function between IOP and injection time have definite physiological significance.
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<p><b>OBJECTIVE</b>To survey and compare the thickness-change of different thickness thermoplastic materials under different test condition and make sure the relationship between the thickness-change and the material initial thickness in order to provide a guide in selecting the suitable thickness thermoplastic in practice.</p><p><b>METHODS</b>To choose Biolon, the thickness include 1.0 mm, 0.75 mm, 0.5 mm. Used Electron Vernier caliper to measure the thickness-change of different thickness thermoplastic materials under different processing mode. The data was analyzed by SPSS 10.0.</p><p><b>RESULTS</b>After thermoforming the thickness of thermoplastic became thinner, the thickness of Biolon 0.75 mm decreased by 0.14 mm, Biolon 1.0 mm decreased by 0.22 mm and Biolon 0.5 mm decreased by 0.14 mm. After saliva immersion the thickness became thicker. The thickness of Biolon 0.75 mm increased by 0.02 mm, Biolon 1.0 mm increased by 0.03 mm and Biolon 0.5 mm increased by 0.02 mm.</p><p><b>CONCLUSION</b>1)The influence of different processing mode to the thickness-change had relation to the material initial thickness. 2)The Biolon 0.75 mm had certain superiority in thickness stability compared to the homogeneous brand through the above research.</p>
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Humanos , Materiales Dentales , Ensayo de Materiales , SalivaRESUMEN
<p><b>BACKGROUND</b>Stent placement has been widely used to assist coiling in cerebral aneurysm treatments. The present study aimed to investigate the hemodynamic effects of stenting on wide-necked intracranial aneurysms.</p><p><b>METHODS</b>Three idealized plexiglass aneurismal models with different geometries before and after stenting were created, and their three-dimensional computational models were constructed. Flow dynamics in stented and unstented aneurismal models were studied using in vitro flow visualization and computational fluid dynamics (CFD) simulations. In addition, effects of stenting on flow dynamics in a patient-specific aneurysm model were also analyzed by CFD.</p><p><b>RESULTS</b>The results of flow visualization were consistent with those obtained with CFD simulations. Stent deployment reduced vortex inside the aneurysm and its impact on the aneurysm sac, and decreased wall shear stress on the sac. Different aneurysm geometries dictated fundamentally different hemodynamic patterns and outcomes of stenting.</p><p><b>CONCLUSIONS</b>Stenting across the neck of aneurysms improves local blood flow profiles. This may facilitate thrombus formation in aneurysms and decrease the chance of recanalization.</p>