1.Quantitative Evaluation of Blood-Brain Barrier Permeability in Early-stage of Experimental Brain Injury
Chinese Journal of Trauma 1990;0(03):-
Fifty-seven rabbits were used for the experimental study of blood-brain barrier (BBB)permeability quantitatively in early stage of brain injury by a designated drop- ping weight method.Animals were divided into three groups:(1) control;(2)brain injury group; (3)therapeutic group.The brain injured animals were treated with antisodamine.Three different sizes of colloidal gold (OG)particles in diameter 5,10 and 15mu were given intravenously as tracers for quantitative investigation of BBB changes with light and electron microscope,respectively.In addition,brain water contents were de4rmined,The preliminary data indicated that the increase of BBB permeability began at 0.5h after trauma showing a few of 5 and 10 mu CG particles present in the endocytic pits and endothelial microvilli.Augmentation of BBB per meability reached its peak 6h after injury.Many 5,10 and 15mu CG tracers were seen penetrating the BBB through the openings at the tight junctions of endothelial cells or by vesicular transportation.The variation of brain water contents was closely correlated to the above mentioned BBB changes.The use of antisodamine resulted in a remarkable attanuation of BBB permeability and seemed advantageous in the treat- meat of cerebral edema after brain injury.
2.Establishment of a Mouse Model of Alzheimer Dementia
Journal of Medical Research 2006;0(04):-
Objective To establish a Alzheimer dementia(AD) model in mice. Methods The C57BL/6 mice were lesioned with ibotenic acid in Nucleus basalis of Meynert(NBM). Behavioral tests by eight-arm radial maze were conducted 8 weeks, and immunohistochemical staining of choline acetyltransferase(ChAT), serotonin(5-HT), GAD(GABA), amyloid-?protein (AP) was conducted 12 weeks after NBM lesioning. Results In NBM lesioned mice, the ChAT-positive neurons, serotonin-positive neurons, and GAD-positive neurons in right NBM reduced, and ChAT-positive neurons reduced most evidently. At the same time, the ChAT-positive fibers in prefrontal and parietal cortices decreased significantly, serotonin-positive axons slightly, accompanied by heavily AP co-expression. On the contrary, there was no change of GAD-positive neurons in cortex. The working memory error increased significantly.Conclusion Ibotenic acid lesioning in NBM can provide as a model of AD in that it produces deafferentation of cholinergic system and recent memory disruption.
3.Three-dimensional nano-level morphological changes of hippocampal neurons either being damaged or protected
Chinese Journal of Trauma 2003;0(12):-
Objective To investigate the effect and mechanism of p38 MAPK inhibition in reducing the damage to rat's hippocampal neurons caused by kainic acid (KA) and observe the three-dimensional morphological changes on the cell surface. Methods The rat's hippocampal neurons cultured primarily for 10 days were pretreated with SB203580 (0.2 ?mol/L, a p38 MAPK inhibitor). Thirty minutes later, the hippocampal neurons were administered with KA at concentrations of 0, 25 and 250 ?mol/L for action for 10 and 100 minutes respectively. The cellular membrane structure was scanned and examined at nano-level by using atomic force microscope. Results Normal neurons displayed smooth membrane surface with homogeneous and regular undulation. In contrast, the neurons treated with KA showed coarse membrane surface with holes. Furthermore, the degree changes increased with the action time and the KA concentrations in a dose-effect dependent fashion. The above-mentioned changes were obviously mitigated by means of pretreatment with SB203580 (200 nmol/L). Conclusions Inhibition of p38 MAPK may, in certain degrees, protect the neurons against the impairments on cytomembrane resulted from the toxic effect of KA.
4.ACTUALITY AND PROSPECTS ABOUT REPAIRING INJURED BRAIN BY TRANSPLANTATION OF NEURAL STEM CELLS
Medical Journal of Chinese People's Liberation Army 2001;0(11):-
As a kind of progenitor cells, the neural stem cells (NSC) possess the potential abilities of both proliferation and differentiation, from which some neurons or glias can be produced. Therefore, the neural stem cells show broad application prospects and clinic utility value. In this paper, the biological characteristics, distributions, main differentiation mechanisms, some experimental skills and application in neurosurgery of the neural stem cells were discussed.
5.THE EFFECTS OF MONOAMINE ON CULTURED NEURONS
Medical Journal of Chinese People's Liberation Army 1982;0(01):-
To study the toxicity of monoamine in high concentrations to neurons. Neurons were treated in vitro with different doses of dopamine, norepinephrine and serotonin for various lengths of time. The toxicity of these reagents on neurons was observed. Apoptosis of neurons was analyzed by agar electrophoresis, in situ DNA end labeling technique and flow cytometry. The results showed that a high concentration of monoamine could induce apoptosis of the culturing neurons. At 24h after treatment with dopamine or norepinephrine (80, 160 and 320?mol/L) as well as with 320?mol/L serotonin, apoptotic rates of neurons were significantly higher than that of the controls, respectively ( P
6.Construction and its significance of the multi-dimensional optimization training pattern for clinical medicine inter-disciplinary talents
Chinese Journal of Medical Education Research 2006;0(11):-
Aiming at present situation and difficult position of clinical medical education,and based on the demand goal of modern medicine,this paper put forward constucting the mul-ti-dimensional optimization training pattern for five-year system clinical medicine inter-disciplinary talents by renewing the education idea,adopting the curriculum reform,the quality regulation,the educational reform,the innovation of teaching methods,and the construction of community medi-cal service practice base and so on,which is of great significance to train the high quality tal-ented person with adaptability to social development.
7.Changes of vital signs and cerebral blood flow after sport in hyperthermal and heavy humid environment
Zhenzhou CHEN ; Ruxiang XU ; Xiaodan JIANG
Medical Journal of Chinese People's Liberation Army 2001;0(07):-
Objective To investigate the changes of vital signs and cerebral blood flow after sport in hyperthermal and heavy humid environment; and to investigate the effect of Urapidil on these changes. Methods 90 soldiers were divided into three groups: new soldiers group, new soldiers taking Urapidil group and veterans group(as group A,B,C). Their vital signs and cerebral blood flow were measured at quiescent condition in normal temperature and after their running for 3000m within 20 minutes in hyperthermal and heavy humid environment. Results Little difference was found among the three groups at guiescent condition in normal temperature. Whereas after exercise, there was significant elevation in body temperature, pulse, systolic pressure and cerebral blood velocity. On the other hand, a little decline in diastolic pressure was showed, but no obvious changes in pulsatility index(PI) following the exercise. Compared with group A, the average body temperature in group B was lower. The cerebral blood velocity in group C was faster and the PI showed lower. Conclusion Sport in hyperthermal and heavy humid environment could significantly affect vital signs and cerebral blood flow of human. The veterans had acquired better heat adaptation than the new soldiers. Urapidil played an important role in pharmacological hypothermia.
8.Effect of hyperthermia on tight junctions of endothelial cells in the in vitro blood-brain barrier model and its molecular mechanism
Yizhao CHEN ; Ruxiang XU ; Zhilin YANG
Chinese Journal of Trauma 2003;0(09):-
Objective To discuss the effect of hyperthermia on tight junctions of the endothelial cells in the blood-brain barrier and explore the molecular mechanism. Methods An in vitro blood-brain barrier model was established by coculture of ECV304 and astrocytes. Transendothelial resistance (TER) of in vitro blood-brain barrier was determined by Millicell-ERS system. The morphological change of tight junctions of the endothelial cells in the in vitro blood-brain barrier was determined by the method of silver staining. The expression levels of zonula occluden 1 (ZO-1) and occludin were analyzed by means of semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) and Western bloting. Results After two hours at 43℃, the mean value of TER was decreased from (321.30? 58.59) ??cm2 to (65.67?6.02) ??cm2. The integrity of tight junctions was destroyed and the expressions of ZO-1 and occludin decreased significantly. Conclusions Hyperthermia can destroy the tight junctions of the endothelial cells in the in vitro blood-brain barrier. The expression decrease of ZO-1 and occludin induced by hyperthermia is one of the most important molecular mechanisms.
9.Analysis on cats' death factors after craniocerebral missile wound under different temperature and humidity
Dexuan MA ; Yanwu GUO ; Ruxiang XU
Chinese Journal of Trauma 1990;0(03):-
ObjectiveTo investigate the changing behavior of cats' vital signs and death factors after craniocerebral missile wound in the environme nt of high temperature and humidity. MethodsA total of 32 hy brid cats were randomly divided into four groups and respectively put into the f ollowing environments after wound, ie, Group A at 25℃ with relative humidity (R H) of 50%, Group B at 35℃ with RH 85%, Group C at 38℃ with RH 90% and Group D at 40℃ with RH 95%. Then, blood pressure, pulse, respiratory frequency and body temperature were recorded every 10 minutes for six hours. Results The vital signs of normal gunshot wound group during the experiment were stable, while body temperature, respiratory frequency and heart rate of cats in each group were significantly different at the same time point with the increa se of temperature and humidity ( P
10.THE EFFECT OF SIGNAL TRANSDUCTION MECHANISM ON BBB DAMAGE IN BRAIN INJURY OF RATS
Ruxiang XU ; Liangping LI ; Shizhen ZHONG
Medical Journal of Chinese People's Liberation Army 1982;0(03):-
This study was designed to explore the mechanism of signal transduction on BBB damage in brain injury. 75 male SD rats were randomly devided into 5 groups: control, sham operation, injury only, injury with Forskolin-treatment and H7 treatment.Evans blue permeation was observed qualitatively with an epifluo resence and mesured quantitatively with a spetrophotometer.The result shcwed that Evans blue significantly permeated in injuried group,and noticeably decereased in H7 treatment group and Forskolin treatment group. It indicated that Forskolin and H7 can effectively prevent BBB opening,and suggest that Forskoling and H7 may provide new ways on BBB protection.