Objective To observe the survival and migration characteristics after intracarotid transplantation of bone marrow stem cells(BMSCs) and its effect on learning-memory abilities across the blood-brain barrier(BBB) in the vascular dementia(VD) rats .Methods Bone mononuclear cells(BMNCs) were isolated from bone marrow in vitro by standard Ficoll-Hypaque technique , then cells were enriched and expanded by using bone marrow adherent culture .72 Wistar rats were meanly divided into control group ,model group and treatment group .The VD rat model was established by modified pulsinellis 4-vessel occlusion(4 VO) .The treatment group received intracarotid infusion of 0 .5 mL 1 .2 × 107/mL BMSCs which were labeled with BrdU in vitro after opera-tion .Their survival ,migration and the learning-memory abilities were observed at 4th and 8th week .Results BMSCs transplanted by intracarotid transplantation survived and had been found throughout the brain tissue .They major migrated and localized in the is-chemic zone of injury such as hippocampus and cerebral cortex .Compared with the control group ,active avoidance response(AAR) ratio in the model group(42 .1 ± 4 .5) ,group(43 .6 ± 3 .6)showed significantly decrease compared with the control group (90 .0 ± 4 .3) ,(92 .5 ± 5 .0)(P<0 .01) ,and the treatment group(69 .2 ± 4 .7) ,(70 .8 ± 4 .7)was significant higher than the model group(P<0 .01) .Conclusion Intracarotid transplantation of BMSCs could enter the VD rats cerebra parenchyma via BBB ,migrate into the damaged brain tissue to gather and survive .Learning-memory abilities can be improved significantly by transplanted BMSCs .

Objective To observe pre-syncopal limited tolerance and cardiovascular responses to head-up tilt combined with lower body negative pressure (HUT/LBNP) following exposure to head-down tilt (HDT, -1 Gz). Method Exposures to HUT/LBNP (-60 mmHg) in control session (without preceding 30 s -1 Gz treatment) and in simulated push-pull effect (PPE) session (with preceding 30 s -1 Gz treatment) were performed in 8 healthy adults. The changes of hemodynamic parameters were monitored by electrical impedance instrument during the experiments. Result The mean endurance time in presyncopal symptom limited HUT/LBNP in control session and in simulated PPE session were 8.4±2.1 min and 4.5±2.4 min, respectively, the two means were significantly different (P< 0.01). In simulated PPE session, as compared with baseline, heart rate (HR) during HDT was significantly lowered (P<0.01), while stroke volume (SV) and cardiac output (CO) were increased significantly (P<0.01). During HUT/LBNP, the increased percentage (relative to baseline) of HR in PPE session was lower than these in control session (P<0.05); the decreased percentages of SV and CO during HUT/LBNP in PPE session were both higher than those in control session (P<0.05). During HUT/LBNP, arterial pulse pressure (PP) of control session was significantly decreased than the value of baseline value (P<0.05); Total peripheral resistance (TPR) of PPE session was significantly increased than baseline value (P<0.05). Conclusion Tolerance time before the appearance of presyncopal symptoms during HUT/LBNP decreases and cardiovascular responses to HUT/LBNP are impaired, preceding exposure to HDT.

Sulfated polysaccharide from Porphyra haitanensis showed inhibitory effect on the lipid peroxidation in vitro. In the present study, the changes in the antioxidative enzyme activity, lipid peroxidation, and total antioxidative capacity (T-AOC) in different organs after 60 Co irradiation were detected in mice by using biochemical methods. Increased endogenous lipid peroxidation and decreased contents of T-AOC as well as decreased activities of super-oxide dismutase (SOD) and glutathione peroxidase (GSH-Px) were observed in mice after 60Co irradiation. Intraperitoneal administration of polysaccharide fraction F2 significantly decreased the lipid peroxidation. F2 treatment increased T-AOC and the activities of SOD and GSH-Px in all organs tested in 60Co irradiated mice. It is concluded that the sulfated polysaccharide fraction F2 from Porphyra haitanensis can be used in compensating the decline in antioxidative capacity arising from radiotherapy and thereby reduced the risks of lipid peroxidation.

BACKGROUND: Studies have demonstrated that trehalose possesses protective effects on cyropreserved sternum. But the mechanism of action remains poorly understood. OBJECTIVE: To investigate the effects of trehalose on bcl-2 and bax mRNA expression in cryopreserved sternum. METHODS: Four groups of freshly prepared solution were used: low-potassium dextran (LPD), LPD + dimethyl sulfoxide (DMSO), LPD + trehalose, LPD + DMSO + trehalose. Rat sternum was cut and then immediately cryopreserved in the tubes containing each group of solution. Fresh rat sternum tissue and 4 groups of samples cryopreserved for 120 days were taken and bcl-2 and bax mRNA expression in fresh and cryopreserved sternum was detected using reverse transcription-polymerase chain reaction.RESULTS AND CONCLUSION: bcl-2 mRNA expression in the LPD + trehalose group was significantly higher, but bax mRNA expression was significantly lower, than in the LPD, LPD + DMSO groups (both P < 0.01). LPD + DMSO + trehalose group showed highest bcl-2 mRNA expression and lowest bax mRNA expression, which were basically similar to fresh bone tissue (P > 0.05). These findings indicate that trehalose may protect cell activity in cryopreserved sternum by enhancing bcl-2 mRNA expression and inhibiting bax mRNA expression, and trehalose together with DMSO shows better protective effects.

The article described the characteristics of research teaching and try to adopt a different research teaching methods based on the characteristics of the contents of each chapter of aerospace biodynamics to enhance the effectiveness of military medicine lesson and cultivate innovative thinking ability of students in military schools.

BACKGROUND: At present, most researches on simulated weightlessness are confined to its effect on the artery. Therefore, the effect on the vein needs to be further studied.OBJECTIVE: To probe into the effect of simulated weightlessness on the ultrastructure of rabbit femoral vein and the remodeling of femoral vein.DESIGN: A completely randomized and controlled trial based on experimental animals.SETTING: Department of Aerospace and Aviation Medical Science, Fourth Military Medical University of Chinese PLA.MATERIALS: The experiment was completed in the Department of Aerospace and Aviation Medical Science, Fourth Military Medical University of Chinese PLA from December 2000 to December 2001. Altogether 24healthy male New Zealand rabbits, weighing 2.0-2.5 kg were obtained.INTERVENTIONS: The model of Head-Down Tilt( -20°) (HDT) simulated weightlessness was established in rabbits. A total of 24 healthy male New Zealand rabbits were randomly divided into control group, 10-day simulated weightlessness group and 21-day simulated weightlessness group, with 8rabbits in each group. The ultrastructure of the rabbit femoral vein was observed under transmission electron microscope.MAIN OUTCOME MEASURES: Changes and degeneration of endothelial cell, mitochondrion, internal elastic membrane, and smooth muscle.RESULTS: Cell organelles in endothelial cell of the femoral vein of HDT rabbits decreased, mitochondrion dissolved and disappeared, vacuolar degeneration in endothelial cell increased and phagolysosome in endothelial cell could be found. Internal elastic membrane became thinner and was broken. The smooth muscle layer became thinner and some smooth muscle cells became degenerated. Cell interstitial substance increased. There was significant difference in changes between 21-day and 10-day simulated weightlessness groups.CONCLUSION: The vascular remodeling of femoral vein occurs with atrophic changes during simulated weightlessness. The longer duration of simulated weightlessness is, the more obviously the structure of femoral vein changes.

The effectiveness of traditional Chinese medicine (TCM) against various diseases urges more low cost,speed and sensitive analytical methods for investigating the phamacology of TCM and providing a theoretical basis for clinical use.The potential of second-order calibration method was validated for the quantification of two effective ingredients of Schisandra chinensis in human plasma using spectrofluorimetry.The results obtained in the present study demonstrate the advantages of this strategy for multi-target determination in complex matrices.Although the spectra of the analytes are similar and a large number of interferences also exist,second-order calibration method could predict the accurate concentrations together with reasonable resolution of spectral profiles for analytes of interest owing to its ‘second-order advantage'.Moreover,the method presented in this work allows one to simply experimental procedure as well as reduces the use of harmful chemical solvents.

Objective Toexploreasimpleandaccuratemethodfordeterminingthequantitativeevaluationandthevolumedegree divisionofpleuraleffusionbyMDCTtissuesegmentationtechnology.Methods Thevolumeofwaterinjectedintothreecontainersof differentshapeswasmeasuredby MDCTtissuesegmentationtechnique,andwerefurthercomparedwiththevolumeoftheactual waterinjection.Byusingthesamemethod,theliquidvolumeofpleuraleffusionbeforeandafterpumpingfrompatientswasmeasured andthedifferencebetweentheanteriorandtheposteriorwascalculated.Thenthedifferencebeforeandafterthepumpingwascomparedwiththe actualvolumeofclinicalfluidpumping.Atthesametime,thespecificmethodtodeterminethedegreedivisionofpleuraleffusionwas established.Results Forcontainersofdifferentshapes,theresultfromtheCTscanningliquidmeasurementwasthesameasactualwater injection,andhadahighcorrelation.Thedifferencebetweenbeforeandafterfluidextractionandclinicalactualfluidextractionwas linearcorrelated(positivecorrelation,r=0.986,P<0.001).Accordingtothemethodfordegreedivisionofadulthemothorax,MDCT tissuesegmentationtechnologydividedthevolumeofpleuraleffusionbeforethepumpingintosmall,mediumandlargeamounts.There were44caseswithsmallpleuraleffusion,11caseswithmoderatepleuraleffusionand7caseswithlargepleuraleffusion.Conclusion The volumeofpleuraleffusion measuredby MDCTtissuesegmentationtechnologycanreflecttheactualvolumeofpleuraleffusionin clinictoacertainextent,and MDCTtissuesegmentationtechnologycanbeusedtodividethevolumedegreeofpleuraleffusion.

Aortic dissection (AD) is a life-threatening vascular disease due to the tearing of aortic intimal layer, leading to the formation of pseudocavity. Once the acute progression of dissection happens, serious complications such as rupture and stroke may occur. The current imaging examinations for AD are invasive and may cause adverse effects related to contrast medium, which cannot be used for large-scale screening of AD. The latest studies have found that metabolic processes and metabolites of lipids,saccarides and proteins are involved in the pathogenesis and development of AD. In this article, we review the research progress in the caracteristics of AD related metabolism,summarize changes of specific metabolites in AD,and explore the clinical implication of studies on AD related metaboliome..

In the field of space exploration,the importance of microorganisms to human health cannot be ignored,and they will play a crucial role in maintaining astronaut health,ensuring habitat sustainability,and ensuring the success of the entire mission.Microorganisms may have negative impacts on space missions,but they also have practical value.This article reviews research progress in recent years on the effects of space environments on microorganisms,the current status of microbial contamination in space environments,detection methods,and the application of microorganisms in the field of space health.It clarifies that research on the impact of microorganisms and microbial ecosystems in space exploration is not only helpful in safeguarding the survival and health of astronauts,but also provides valuable reference for future space exploration projects.