An inflatable liquid epidural balloon was used to simulate an intracranial space-occupying lesion.Two groups of dogs with 8 in each were employed.Under different conditions and time intervals,intracranial pressure(ICP)was continuously recorded,and pressure-volume index(PVI),volume-pressure response(VPR),and cerebrospinal fluid pulse pressure(CSFPP)were measured silmutaneously.It was found that PVI was in significant negative linear correlation with ICP,while VPR and CSFPP in significant positive linear correlation with IVP(P

In order to study Whether there was rejection in brain tissue transplantation,the embryonic cerebral neoeortex from rat or mouse donors which were 16 to 18-day-old embryos was diffc!rent time after transplantation,the brain graft tissues were stained immunocytochemically to examine the expression of MHC-class Ⅱ antigens and subsets of T-cells.The results indicated that the survival rate of treatment group with immunosuppressant was higher than that of non-treatment group.Immunocytochemical evaluation showed that a large number of T-cells appeared. A significant increase of the number of class Ⅱ major histocompatibility complexes (MHC) expressing cells was found within and around the allografts.We conclude that the CNS is not an"immunologically privileged site"and there is graft rejection existing in brain transplanta-tion.It is necessary to treat brain transplant with immunosuppressant.

Objective To study the relationship between GFAP and the malignant degree of astrocytoma. Methods After successful transfer of retrovirus with GFAP (PLBsKG) into C6 cells mediated with liposome, the morphology, growth curve and the proliferative cycle of the target cells were observed. The expression of the protein and mRNA of GFAP was determined with RT-PCR and immunocytochemical staining. In addition, the relationship between the staining GFAP-IR and the malignant degree of astrocytoma was analyzed according to Kermohan′s grading standard in 20 samples of the cells of astrocytoma with imaging analytic system. Results PLBskG resulted in the decrease of GFAP in the target C6 cells, and changed the morphology and increased the proliferation of C6 cells. The number of the cells in the G 2+M phages was increased. The intensity of GFAP-IR staining was negatively correlated to the malignant potency of astrocytoma. The more intensive staining of the cells, the lower of the malignant degree of astrocytoma and vice versa. Conclusion There is a close relationship between GFAP and malignant degree of astrocytoma. The level of GFAP expression serves the index of the malignant degree and prognosis of astrocytoma in certain degree.

Objective To investigate the effects of mutated PS-1 on the proliferation and apoptosis of RA-induced PC12 cells . Methods The MTT assay, flow cytometry, TUNEL method were used in the research. Results An inhibition of proliferation was demonstrated in the RA-induuced PC12 cells expressing PS-1 mutant L286V. The proliferation of the cells was blocked in the G1→S phase. Whether with or without fetal bovine serum(FBS), PS-1 mutant L286V was able to accelerate the apoptosis of RA-induced PC12 cells. This action was enhanced markedly under the culture without FBS. Conclusions The RA-induced PC12 cells expressing PS-1 mutant L286V shows that the proliferation is inhibited and blocked in the G1→S phase. Whether with or without FBS, PS-1 mutant L286V can accelerate the apoptosis of RA-induced PC12 cells. This action is enhanced markedly under the culture without FBS.

Objective　To explore the role of tyrosine hydroxy lase (TH) gene in the treatment of Parkinson's disease (PD) by using ex vivo gene transfer. Methods　After the construction of TH gene in a retroviral vector, the astrocytes were cultured with the supernatant containing the recombinant DNA and then grafted into the cerebrum of PD rats. The reduction of the rat rotation beharior was evaluated. Results　The rotati on of PD rats was markedly improved in the rats with ex vivo gene transfer. Conclusion　TH has an obvious efficiency on the treatment of PD and the astrocytes can be used as effective gene transfer cells.

Objective　To study the occurence, development and regulation of reactive gliosis with astrocyte (Ast) in vitro. Methods　Ast was isolated and cultured in vitro and its model of reactive gliosis was established by scratching the cultured astrocytes. The reactivity and rules of Ast to injury was studied by morphological changes, RT-PCR, immunocytochemistry, in situ hybridization and imaging analysis. Results　After scratching, the astrocytes showed typical features of reactive gliosis, with the hypertrophic cell body, thickened and lengtheded processes, and enhanced glial fibrillary acidic protein (GFAP) staining. In situ hybridization and RT-PCR analysis confirmed that the expression of GFAP mRNA was markedly increased. These changes occurred 1 d after scratching and reached the peak 5 to 7 d after injuring. Conclusion　A model of reactive astrogliosis was successfully established in vitro which showed an active reaction to injury. The characteristics of reactive gliosis parallel that seen in vivo.

Objective To investigate the cholinergic neuron properties and the changes of proliferation and apoptosis of PC 12 cell induced by different concentrations of all trans retinoic acid(RA). Methods PC 12 cell was induced by RA of concentrations of 1-50 ?mol/L. Changes of cell growth curve and cycle, apoptosis and changes of activities of acetylcholinesterase(AchE) and choline acyltransferase(ChAT) were detected by MTT assay, flow cytometry, TUNEL method, spectrophotometry and radiochemistry assay, respectively. Results ① RA significantly enhanced the activity of ChAT with concentrations between 1 to 20 ?mol/L. The activity of ChAT with concentration of 10 ?mol/L was higher than those with other concentrations. ② The apoptosis of RA induced PC 12 cells was markedly enhanced when concentration was higher than 10 ?mol/L. ③ A concentration dependent inhibition of proliferation was demonstrated in the RA induced PC 12 cells. ④ PC 12 cells proliferation was blocked in the G 1→S phase. Conclusion RA can be used to induce PC 12 cells to show the properties of cholinergic neuron with an optimal concentration of 10 ?mol/L.

Objective To investigate the influence of physiological motions on three-dimensional (3D) CT images and the rules of motion artifacts.Methods A mathematical model of motion artifact was set up based on the principle of spiral scanning, hereby the geometrical distortion of 3D image was analyzed.Experiments were carried out with home-made phantoms on a CT scanner.Results The details of 3D images with trivial distortion were legible under static condition.On the contrary, distinct distortion occured under moving condition, and its degree increased with the pitch and motion period. The 3D images were varied with difference of the motion initial phases.Conclusion The distortion of 3D-CT image depends on the motion characters of scanned objects and scanning parameters such as pitch and slice thickness.

Thirty-seven cases of brain glioma,confirmed by light microscopy and immuno-'histochemistry were studied with transmission electron microscopy.It was found that there were certain ultrastructural features for each type and each grade of glioma.In astrocytoma,there was certain amount of glial filaments in the tumor cells; Rosenthal fibers consisted of irregular osmiophilic masses surrounded with glial filaments,occasionally cytoplasmic annulate lamellae and intranuclear filaments could be seen,and the interstitial capillaries were characteristic.In typical oligodendroglioma,astrocytic processes containing glial filaments were quite present in different amounts.These findings suggest that observation on the ultrastructure of gliomas is of significance to establish the diagnosis,to assess the degree of differentiation,and to identify some rare structures which can reveal the essence of the tumor.In addition,ultrastructural observation is helpful for prognosis.

Objective To investigate the changes of NGF mRNA expression and the effect of exogenous interleukin 1?(IL 1?) on it in rats after traumatic brain injury(TBI) and to explore the mechanism of NGF and IL 1? in TBI. Methods A brain trauma model of fluid percussion in rats was established. Changes of NGF mRNA expression and effect of exogenous IL 1? on it were observed by RT PCR, molecular hybridization and immunocytochemical techniques. Results NGF mRNA expression in the brain injury site and tissues adjacent to it began to increase at 12 h after trauma and increased markedly at 24 h and reached the peak value on the 3rd. Then it decreased gradually, but still higher than that of the control. NGF mRNA expression increased at 3 h after trauma in IL 1? treatment group and was significantly higher than that in simple trauma and control groups( P