A new oxoaporphine from Sabia limoniacea var. ardisioides / 药学学报

The chemical constituents of Sabia limoniacea var. ardisioides were investigated using chroma­tographic methods, such as silica gel, Sephadex LH-20 and preparative HPLC. Eight compounds were isolated and their structures were elucidated by spectral data and physicochemical properties, which were identified as 5-methoxy-1,2-methylenedioxyl oxoaporphine (1), fuseine (2), N-p-feruloyltyramine (3), N-trans-coumaroyl tyramin (4), quercetin (5), rutin (6), mutabiloside (7), and protocatechuic acid (8). Among those, compound 1 is a new compound, compounds 2−8 were isolated from this plant for the first time.

Teaching"Medical Electronics"course in military medical university / 医疗卫生装备

Objective To improve the theory and practice learning of the students majoring in medical imaging by investigating the teaching method of"Medical Electronics"course.Methods The problems in teaching"Medical Electronics"course were summarized, and the causes were analyzed. Results Some improvement measures were proposed for teaching"Medical Electronics"course with considerations on the professional background of the students and the characteristics of the course, which proved its efficiency through practical trial. Conclusion For teaching medical students in electronics technology course,the methods such as integrating and optimizing contents of course,guided teaching as well as experiments and discussions by groups,have significant effects on improving students'learning enthusiasm and teaching efficiency.

Human placenta-derived mesenchymal stem cell transplantation provides neuroprotection against cerebral infarction in rats / 中国组织工程研究

BACKGROUND: Bone marrow mesenchymal stem cells improve neurological functional recovery from cerebral infarction, but they are a rare population in the bone marrow with difficulty in cell separation and purification. OBJECTIVE: To investigate the neuroprotective effects and the potential mechanisms of human placenta-derived mesenchymal stem cell transplantation for cerebral infarction in rats. METHODS: Totally 120 rats subjected to middle cerebral artery occlusion were randomized into treatment group and control (n=60 per group). The rats were intravenously treated with human placenta-derived mesenchymal stem cells in the treatment group or the phosphate buffer saline in the control group. Then, a modified neurological severity score was assessed at 1, 3, 7, 14 days post transplantation, and measurement of infarct volume in the ischemic brain was performed using 2,3,5-triphenyltetrazolium chloride staining at 14 days post transplantation. The anti-human specific immunostain for mitochondria in the ischemic brain was performed and the mitochondria-positive cells were counted; TUNEL immunostaining was performed and TUNEL positive cells were counted. ELISA assays for brain-derived neurotrophic factor (BDNF), vascular endothelial growth factor (VEGF) and hepatocyte growth factor (HGF) were also performed in the ischemic brain. RESULTS AND CONCLUSION: At 1, 3, 7 and 14 days after treatment, the modified neurological severity score in the treatment group was significantly lower than that in the control group (P < 0.05). At 14 days after treatment, the infarct volume in the treatment group was significantly lower than that in the control group (P < 0.05), only few mitochondria-positive cells were present in the ischemic brain, and the number of TUNEL positive cells in the treatment group was significantly less than that in the control group (P < 0.05). At 3 and 14 days after treatment, BDNF expression levels in the treatment group were significantly higher than those in the control group (P < 0.05). At 7 and 14 days after treatment, VEGF expression levels in the treatment group were significantly higher than those in the control (P < 0.05). At 7 days after treatment, HGF expression level in the treatment group was significantly higher than that in the control group (P < 0.05). To conclude, intravenous administration of human placenta-derived mesenchymal stem cells can promote neuroprotective effects against cerebral infarction. These effects may be related to the increase of BDNF, VEGF and HGF expression and the decrease of apoptosis in the ischemic brain.

In-vivo and ex-vivo studies on region-specific remodeling of large elastic arteries due to simulated weightlessness and its prevention by gravity-based countermeasure / 生理学报

The present study was designed to test the hypothesis that a medium-term simulated microgravity can induce region-specific remodeling in large elastic arteries with their innermost smooth muscle (SM) layers being most profoundly affected. The second purpose was to examine whether these changes can be prevented by a simulated intermittent artificial gravity (IAG). The third purpose was to elucidate whether vascular local renin-angiotensin system (L-RAS) plays an important role in the regional vascular remodeling and its prevention by the gravity-based countermeasure. This study consisted of two interconnected series of in-vivo and ex-vivo experiments. In the in-vivo experiments, the tail-suspended, hindlimb unloaded rat model was used to simulate microgravity-induced cardiovascular deconditioning for 28 days (SUS group); and during the simulation period, another group was subjected to daily 1-hour dorso-ventral (-G(x)) gravitation provided by restoring to normal standing posture (S + D group). The activity of vascular L-RAS was evaluated by examining the gene and protein expression of angiotensinogen (Ao) and angiotensin II receptor type 1 (AT1R) in the arterial wall tissue. The results showed that SUS induced an increase in the media thickness of the common carotid artery due to hypertrophy of the four SM layers and a decrease in the total cross-sectional area of the nine SM layers of the abdominal aorta without significant change in its media thickness. And for both arteries, the most prominent changes were in the innermost SM layers. Immunohistochemistry and in situ hybridization revealed that SUS induced an up- and down-regulation of Ao and AT1R expression in the vessel wall of common carotid artery and abdominal aorta, respectively, which was further confirmed by Western blot analysis and real time PCR analysis. Daily 1-hour restoring to normal standing posture over 28 days fully prevented these remodeling and L-RAS changes in the large elastic arteries that might occur due to SUS alone. In the ex-vivo experiments, to elucidate the important role of transmural pressure in vascular regional remodeling and differential regulation of L-RAS activity, we established an organ culture system in which rat common carotid artery, held at in-vivo length, can be perfused and pressurized at varied flow and pressure for 7 days. In arteries perfused at a flow rate of 7.9 mL/min and pressurized at 150 mmHg, but not at 0 or 80 mmHg, for 3 days led to an augmentation of c-fibronectin (c-FN) expression, which was also more markedly expressed in the innermost SM layers, and an increase in Ang II production detected in the perfusion fluid. However, the enhanced c-FN expression and increased Ang II production that might occur due to a sustained high perfusion pressure alone were fully prevented by daily restoration to 0 or 80 mmHg for a short duration. These findings from in-vivo and ex-vivo experiments have provided evidence supporting our hypothesis that redistribution of transmural pressures might be the primary factor that initiates region-specific remodeling of arteries during microgravity and the mechanism of IAG is associated with an intermittent restoration of the transmural pressures to their normal distribution. And they also provide support to the hypothesis that L-RAS plays an important role in vascular adaptation to microgravity and its prevention by the IAG countermeasure.

Effects of simvastatin on vasa vasorum and aortic endothelial function in rats / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effect of hyperlipidemia on vasa vasorum and vascular endothelial growth factor (VEGF) and study the role of vasa vasorum in arteriosclerosis.</p><p><b>METHODS</b>Thirty SD rats were randomized into normal control, hyperlipidemic and simvastatin treatment groups (n=10). In simvastatin group, hyperlipidemia was induced by a 4-week administration of atherogenic diet followed by a 16-week treatment with simvastatin at the daily dose of 10 mg/kg, and the rats in hyperlipidemic rats received no treatment. The changes in the aorta and vasa vasorum were examined, and serum lipid concentration and VEGF and NO levels were measured.</p><p><b>RESULTS</b>Compared with the control group, the hyperlipidemic rats showed significantly thickened intima and media aorta and increased vasa vasorum density with lowered NO level, but VEGF underwent no significant changes. Simvastatin treatment significantly reduced the thickness of the intima and media aorta and increased vasa vasorum density in comparison with those in hyperlipidemic group. Simvastatin treatment also significantly increased VEGF and NO levels and a positive correlation was noted between their levels.</p><p><b>CONCLUSION</b>Hyperlipidemia can impair the vasa vasorum and aortic endothelial function. Simvastatin increases VEGF and NO and promotes neogenesis of the vasa vasorum for the benefit of the aortic function.</p>

The expansion characters of a quick-heating gypsum-bonded investment under different heating methods / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To study the effects of different heating timings after mixing the materials and different heating methods on the expansion characters of a quick-heating gypsum-bonded investment.</p><p><b>METHODS</b>The setting expansion rate of GC Cristoquick II gypsum-bonded investment was measured with a setting expansion tester 30, 60, 120 min after mixing the material respectively. The thermal expansion rates of the material at different setting time (30, 60, 120 min after mixing) and under different heating treatment methods (quick and conventional heating techniques) were also determined using a thermal dilatometer for dental investments, the total linear expansion rate were calculated. The effects of heating time and heating methods on the expansion of the investments were statistically analyzed with SPSS 11.0 software, using ANOVA multiple comparison (alpha=0.05).</p><p><b>RESULTS</b>Statistical differences were found among the setting and thermal expansion rates of the investment at different heating timings after mixing the material (P<0.01). Setting expansion, thermal expansion and total expansion rates increased with the setting time before heat treatment, while thermal expansion rates under different (quick and conventional) heating methods were not statistically significant (P>0.05).</p><p><b>CONCLUSION</b>The expansion characters of the quick-heating gypsum-bonded investment are influenced by different heating timings after mixing the material. The heat treatment technique of this quick-heating investment recommended needs to be modified to ensure casting precision.</p>