BACKGROUND: Critical closing pressure (CCP) is recently thought to play a key role in cerebral blood flow autoregulation as an effective downstream pressure of cerebral circulation and can objectively reflect the cerebrovascular tone, namely the vascular smooth muscle contraction and diastole, which is subjected to dynamic modulation.OBJECTIVE: To dynamically assess the hypertension-induced damage of the contraction function of cerebral microvascular smooth muscles and its correlation with morphological changes based on CCP evaluation.DESIGN: Randomized controlled experiment.SETTING: Institute of Neural Science of Second Hospital Affiliated to Guangzhou Medical College and Department of Neurology, First Hospital Affiliated to Sun Yet-san University.MATERIALS: The experiment was carried out at the Laboratory of Physiological Science of Sun Yet-san University between July 2002 and August 2003. Totally 160 health male SD rats were randomized into control group and hypertension group with 80 rats in each group. METHODS: Stroke-prone renovas cular hyp ortonsive rats were established in rats of the hypertension group by bilateral renal artery occlusion with two clips. The rats in the control group were not subjected to the occlusion with other treatments identical to those of the hypertension group. At the time points of 2, 4, 6, 8, 10, 12, 14 and 16 weeks after operation, respectively, 10 rats were randomly selected from each of the two groups for determination of arterial pressure and CCP. After the measurements the frontal-parietal lobe was obtained from the anaesthetized rats and cut into slices for quantitative analysis of the morphological changes in cerebral microvessels.different postoperative time points.mean arterial pressure in hypertension group obviously increased from the 6th postoperative week with significant difference from that of the control after operation to a level significantly higher than that of the control group at postoperative 14 and 16 weeks [(63.75±7.43) vs (37.28±3.68) mm Hg and (67.37±15.57) vs (38.39t7.41) mm Hg, respectively, P ＜ 0.05].significance from that of the control group at the 8th postoperative week (Paverage arterial pressure and cerebral arteriole tunica media (r=0.906 93,0.811 36, respectively, P ＜ 0.05). The changes in CCP was more obvious in the early and advanced stages of blood pressure elevation, but not so manifest during obvious blood pressure increment, displaying an inverted S-shaped curve of changes (R2=0.996 2, P ＜ 0.05).CONCLUSION: Contraction of the cerebrovascular smooth muscles is enhanced with the dynamic increment of arterial pressure after the development of hypertension. Vascular tone increase is more manifest during the early and advanced stages of hypertension.

Objective To investigate the synergistic effects of 9-cis-retinoic acid(9-cis-RA) and 8-cl-cAMP on growth inhibition and apoptosis induction in H460 and H292 cell lines of non-small-cell lung cancer(NSCLC). Methods Experimental groups included 9-cis-RA groups(1,5,10 and 20 ?mol/L),8-cl-cAMP groups(5,10,20 and 50 ?mol/L),9-cis-RA(5 and 10 ?mol/L) combined with 8-cl-cAMP(10 ?mol/L) groups and blank control group.The cell growth inhibition rates were detected by trypan blue staining,and the apoptosis of H460 and H292 cells were observed by Hoechst33258 fluorescence microscope,DNA gel electrophoresis and flow cytometer(FCM). Results 9-cis-RA inhibited the growth of H460 cells in a time-and dose-dependent manner,and induced the apoptosis of H460 cells(P

Objective:To study the effect of Jianpi Qinghua Recipe ( JPQHR) on angiotensin II/NADPH oxidase pathway in 5/6 nephrectomized rat renal failure model and the underlying mechanisms.
Methods:The animals were divided into 4 groups:the sham-operated group, the renal failure group, the JPQHR-treated group and the losartan-treated group. After 60-days therapy, serum nitrogen and creatinine were measured. The expression of angiotensin II type 1 receptor (AT1) protein and the expression of p47phox mRNA in renal tissue was determined. SOD and MDA were also examined.
Results:Compared with the sham-operated group, the levels of SCr and serum BUN and the AT1 protein and p47phox mRNA expression in the renal failure group were significantly increased. hTe activities of SOD in renal tissue from the renal failure group was signiifcantly down-regulated while MDA was up-regulated (P<0.05). Compared with the renal failure group, the levels of SCr and serum BUN and the AT1 protein and p47phox mRNA expression in both JPQHR-treated group and losartan-treated group were signiifcantly decreased. hTe activities of SOD in renal tissue from JPQHR-treated group and losartan-treated group were signiifcantly up-regulated whereas the content of MDA were down-regulated (P<0.05). Compared with the losartan-treated group, the activities of SOD in renal tissue from the JPQHR-treated group was obviously increased (P<0.05), the decrease in AT1 protein and p47phox mRNA was more evident but not statistically different (P>0.05). The level of SCr and serum BUN and the content of MDA were also not statistically different (P>0.05).
Conclusion:hTrough decrease the expression of angiotensin II and NADPH oxidase, JPQHR can reduce the oxidative stress in chronic renal failure and delay the renal ifbrosis progression.

Objective To observe the process of Vibrio vulnificus inducing dendritic cell strain apoptosis.Methods We established the mixed culture model of mouse dendritic cell ( DC 2.4 strain) and Vibrio vulnificus( Vv1.1758 strain ),analyzed morphological characteristics of cell apoptosis by DAPI fluorescence staining,detect DNA fragmentation level of apoptosis cells by DNA Ladder assay,analyze DC2.4 apoptosis rate by Annexin V FITC/PI staining,determine activities of caspase-3 and caspase-8 by means of spectrophotometric method and detect changes of mitochondrial transmembrane potential ( △ Ψm ) by JC-1 fluorescence labeling.Results After Vv1.1758 strain and DC2.4 cell were mixed and cultured for 4 h,DAPI fluorescence staining showed typical apoptosis characteristics-chromatin condensation and marginalization; DNA agarose gel electrophoresis showed apoptosis band; apoptosis rates at 2,4 and 6 h were respectively (37.8±9.8) ％,(54.3 ± 12.7 ) ％ and ( 68.2± 14.6 ) ％ ; Mitochondrial transmembrane potentials (△Ψm) at 1 h,2 h and 4 h reduced by 7.1％,16.1％ and 46.7％ respectively; caspase-8 activity increased at 1.5 h and reached the peak at 2 h [ (2.48±0.19) U/μg],while caspase-3 activity started to increase at 3h and reached the peak at 4 h [ ( 1.91 ±0.16) U/μg ].Conclusion Vibrio vulnificus could induce dendritic cells by two pathways: reducing mitochondrial transmembrane potential and activating caspase-8 promoter and finally activate effector caspase-3 to promote apoptosis.

Objective To establish a novel TRFIA for the measurement of heparanase (HPA) in serum samples,and investigate its clinical application.Methods The micro-pore plate wells were first coated with partially recombinant murine anti-human HPA monoclonal antibody.Biotin-labeled recombinant HPA protein was then used to compete with HPA in serum samples,and the prepared europium (III)-labeled streptavidin (Eu3+-SA) was used as signal readout for establishing the BSA-TRFIA assay.Using this assay,the serum HPA levels in healthy subjects (n=32) and tumor patients (n=54) were measured.The results of BSA-TRFIA were compared with those of ELISA.Two-sample t test (or t' test),and linear correlation analysis were used to analyze the data.Results The sensitivity of BSA-TRFIA for measuring HPA was 0.33 ug/L.The CV values for intra-batch and inter-batch were 5.29% and 7.54%,respectively.The average recovery rate was 105.5%.The standard curve range was 0-1 000 ug/L.The serum HPA level measured by the BSA-TRFIA method in healthy subjects was (2.03_+ 1.47) Iug/L.In tumor patients,the HPA level was significantly higher:(22.13_+7.38) ug/L (t'=19.388,P

Background Glial cells perform specialized function in many aspects of the development,homeostasis,and function of neurons.Retinal ganglion cells (RGCs)and glia interactions are critically important in glaucomatous neurodegeneration.However,the precise mechanisms of glial activation and ganglion cells damage are still remained unclear. Objective This study was to assess the early responses of glial cells in the retina,optic nerve and optic chiasm in rat models of acute high intraocular pressure (IOP),and to examine the expression of nestin,a neuronal progenitor marker,in the reactive glias. Methods Acute high IOP of 110 mmHg was induced in the right eyes of 6 clean adult female Wistar rats by infusing normal saline solution into the anterior chamber for 60 minutes.Three normal matched Wistar rats were used as controls.The rats were sacrificed by overanaesthesia and sections of retina,optic nerve and optic chiasm were collected on 3 days and 7 days after the injection.Rat retina was examined by Nissl staining to illustrate the gross structure changes.Loss of axons of RGCs in the optic nerve was assessed by immunostaining of β Ⅲ-tubulin.Double labeling of glia] fibrillary acidic protein (GFAP) and nestin was performed in sections of retina,optic nerve and optic chiasm to evaluate the glial responses.The use of the animals complied with Statement of Animal Ethic Committee of Peking University Third Hospital. Results In control rats,GFAP-positive glial cells were observed in the retina,optic nerve and optic chiasm,where only weak positive response for nestin was noticed.Three days after acute IOP elevation,thickness of inner plexus form layer was significantlydecreased in comparison with the control rats.A loss of 46％ RGCs was found in the rats with ocular hypertension.Obvious increase of GFAP expression was displayed in the retina,and processes of GFAP-positive glia cells extended into outer retina accompanied with significant up regulation of nestin.Axons in the optic nerve demonstrated a tendency of degeneration.Nestin expression increased significantly in the GFAP-positive glias in the optic nerve.Cross-sectional area of optic chiasm corresponding to the injured retina decreased relative to its countcrpart.Astrocyte like GFAP and nestin-colabeled glials were observed in this part of optic chiasm.The pathological changes of the retina,optic nerve and optic chiasm in hypertensive eyes aggravated on 7 days. Conclusions Acute ocular hypertension induce early onset of RGCs loss and axon degeneration.Neuronal injury is accompanied with glial reaction.Reactive glial cells express neuronal progenitor markers.The structural changes of the optic nerve and optic chiasm occur simultaneously with the high IOP.

Objective To establish real-time PCR with SYBR Green Ⅰ for quantification the gene of survivin.Methods The components and conditions of PCR system were optimally determined by fluorescence intensity,cycle threshold(Ct),melting curve,coefficiency and slope of the standard curve.The means to eliminate the contaminating fluorescence of primer-dimers and the mode for Ct value determination were also optimized.Using the developed PCR system,we quantificated the survivin gene in 43 patients with gastric carcinoma.Results The optimized condition for PCR amplification of survivin were 2 mmol/L of MgCl_2,2.5 U/100 ?l of Taq DNA polymerase,0.2 ?mol/L of primers,and the optimized annealing temperatures for PCR were 58℃.The influence of primer dimmer can be eliminated by setting the fluorescence collecting temperature below the Tm of the specific amplicon by 2℃.The second derivative maximum mode,instead of fit point mode,was a feasible method to determine the Ct value for quantification.The sensitivity of this method was 10 copies/?l,and a good linearity was found from 10~1 to 10~4 copies/?l(r = 0.999 7).The inter-experimental coefficient of variation was 1.13%-1.91%,whereas the coefficient of variation between runs was 3.31%-4.50%.Using the optimized PCR system,we quantificated the gene of survivin,the result indicated that survivin gene was amplified in 13.9% of gastric carcinomas.Conclusions The optimal real-time PCR with SYBR Green Ⅰ,as a cost-effective and feasible DNA quantitative method,is fit for quantification of the survivin with satisfactory repeatability and high sensitivity.

Objective To prepare controlled release microspheres of vascular endothelial growth factor(VEGF)& calcium alginate and observe their effect on proliferation of human umbilical vein endo- thelial cells(HUVEC)in order to provide theoretical basis for controlled release of VEGF facilitating an- giogenesis of tissue engineering bone.Methods VEGF-calcium alginate microspheres were prepared by using the needle extrusion/external gelation method to investigate physicochemical character and in vitro release of VEGF.According to the different ingredients added into the culture medium,the seconda- ry cultured HUVEC were divided into four groups,ie,control group,microsphere group,VEGF group and VEGF-calcium alginate microsphere group,in which the proliferation of the cultured HUVEC was ob- served with cell counting method,MTT method and flow cytometry.Results The calcium alginate mi- crospheres were revealed as spherical shape and evenly distributed,with mean grain diameter of(560?50)?m,carrying capacity of 0.72 ng/mg and the encapsulation efficiency of 54%.Smooth controlled re- lease in VEGF-alginate microspheres lasted for more than 10 days.Proliferation of the cultured HUVEC was accelerated the most in VEGF group at the beginning but in EGF-calcium alginate microsphere group at midanaphase compared with other groups,with statistical difference(P＜0.05).There was no statis- tical difference upon cell counting,cell activity and time point of cell cycle between control group and mi- crosphere group.Conclusion VEGF-sodium alginate microapheres can continue activity of VEGF,re- lease VEGF for over 10 days and promote proliferation cultured HUVEC for a long time.

Objective To explore the pathological changes by CT scan on localized thermochemotherapy dur- ing and after the operation of human gliomas.Methods Retrospective analysis was given to the CT scan of 37 pa- tients receiving thermochemotherapy during and after the operation,and the relation of the tumorous cells and mi- crovessels and CT density by EM were analyzed.Changes of tumorous cells and microvessels after localized ther- mochemotherapy on C_6 gliomas in rat were analyzed.Results When the tumor was low dense on CT pattern,less cellular number with increasing the amount of fluid between the cells was demonstrated pathologically.On EM,a lower cellular electron density was observed.The amount of fluid in cytoplasm was increased,the cytoplasm was porous,swelling denaturation was chiefly seen in organelle.If the tumor had mixed density on CT,cellular number was more,the amount of fluid was less.On EM,cellular electron density increased correspondingly,the fluid in cyto- plasm decreased,organdie was aggregated.After thermochemotherapy,the tumor reduced,liquefied,and vanished by CT scan.It could be observed that the tumorous cell become smaller,concentrated and cataclased,finally formed apoprotic bodies and separated from the cell in C_6 gliomas in EM.The tumorous vessels was less,smaller and thinker. Some vessels only could see the base membrane and no endothelioid cells.Conclusion The remaining tumors is van- ished by CT scan.The mechanisms of tumors disappearance proposes to explain that thermochemotherapy can dam- age C_6 glioma cells and microvessels,decrease microvessels density and induce tumor ceils apoptosis.That inhibits tu- morous angiogenesis and proliferation.

OBJECTIVE: To explore the injury mechanism of the human knee in a traffic accident by establishing a 3D finite element (FE) model. METHODS: The FE model, composed of femur, tibia, fibula, patella, meniscus, knee ligaments and surrounding soft tissues, was reconstructed by CT scanning data from a male volunteer. Validation was performed by the lateral impact simulation, and the stress and strain results were obtained to be compared with those previously reported for injury prediction. RESULTS: The results derived from the FE model were found to be similar with those previously reported, most of the ligaments and meniscus wounded at 40 m/s collision, which was readily observed. CONCLUSION The simulation results generated by FE model can be effectively used for the injury mechanism analysis of initial contact.
Accidents, Traffic ; Biomechanical Phenomena ; Femur ; Finite Element Analysis ; Humans ; Knee Injuries/etiology* ; Knee Joint ; Male ; Models, Theoretical ; Tibia