AIM: To investigate the mechanism that antioxidants TA9901, inhibit the formation of amyloid-?-protein(A?) fibril. METHODS: Fourier-transform infrared spectroscopy was used to study the secondary structure changes on aging A? in vitro. RESULTS: A? aged alone for 30 min, the content of ?-pleated sheet and ?-turn were 43.17% and 32.9% respectively. A? aged alone for 7 days, the content of ?-pleated sheet increased abuot 10% and produced a shift of random coil toward ?-pleated sheet. TA9901 induced a significant decrease of the content of ?-turn (23.5%) and ?-pleated sheet (26.4%). VE mainly decreased the ?-pleated sheet content (30.8%). The combination of TA9901 and VE promoted transition of ?-turn (16.7%) toward ?-helix and random coil. CONCLUSIONS: Both of TA9901 and VE can effectively diminish the ?-structural content. TA9901 showed more intensitive inhibition than VE. The effect of TA9901 on the secondary structure of aged A? was associated with the mechanism that TA9901 inhibited A? aggregation and fibril formation.

Objective To investigate the distribution and chemical character of nestin immunoreactive cells in the human basal forebrain. Methods We explored systematically the distribution of nestin immunoreactive cells throughout the human basal forebrain by nestin 331B, 10C2, Rat401 antibody.Furthermore, we investigated the chemical identity of these nestin immunoreactive cells by using double\|labeling immunocytochemistry with NSE, ChAT, p75NGFR, GFAP antibody or using NADPH\|d histochemistry. Results The nestin immunoreactive cells were found in the septum, diagonal band of Broca, innominate substance,amygdala,basal nucleus of Meynert of adult human brain.These nestin immunoreactive cells haven big cell body,2\|3 processes.The nestin immunoreactive cells were labeled by NSE antibody.The large majority of those were single stained,and 28% were double labeled with ChAT positive neurons,15% with NGFR positive neurons,6% with NOS positive neurons.A few nestin immunoreactive cells shared similar morphology with that of astrocyte glia which existed in the spaces between the thin septa pellucida or the midline along the septum.It could not be labeled by GFAP antibody.Conclusion\ A new cluster of nestin immunoreactive neurons that were different from the ChAT,NGFR,NOS positive neurons existed in adult human basal forebrain.\;[

AIM: To investigate the mechanism by which TA9902 inhibits the formation of amyloid ?-peptide (A?) fibrils. METHODS: Fourier-transform infrared spectroscopy was used to study the secondary structure changes on aging A? in vitro. RESULTS: The content of ?-pleated sheet were 46.53% in the condition of A? aged alone for 30 min. When A? aged alone for 72 h, the content of ?-pleated sheet increased about 19.4% and produced a shift of random coil toward ?-pleated sheet. TA9902 induced a significant decrease in the content of ?-pleated sheet (36.09%). CONCLUSION: TA9902 effectively diminishes the ?-pleated structural content. The effect of TA9902 on the secondary structure of aged A? is associated with inhibition of A? aggregation and fibril formation.

AIM　To study the effects of Aβ25～35 and Apo E4 on neuronal intracellular free Ca2+(［Ca2+］i). METHODS　Hippocampal and cortical neurons suspension of newborn(0～3 days) SD rats was produced. After incubated with fura-2/AM,the neurons suspension was divided into four groups: control, Aβ25～35, Apo E4, Aβ25～35+Apo E4. Each groups ［Ca2+］i was measured using a RF-5000 dual wavelength spectrofluorometer after incubated with double distilled water, Aβ25～35, Apo E4, Aβ25～35+Apo E4 for 3 min, respectively. The neurons outocorrelation function(ACF) of the scattering light intersity was analyzed by the microscope quasi-elastic light scattering(MQLS) technique The frequency shift line width by ACF. The Γ can sympolize the cell menbrane flilidity. RESULTS　Both Aβ25～35 and Apo E4 could significantly enhance hippocampal and cortical neurons rest ［Ca2+］i, furthermore, the effect of 5 μmol*L-1 Aβ25～35 was higher than the effect of 1 μmol*L-1 Aβ25～35 (P<0.05), and they also amplified KCl-induced rise in ［Ca2+］i in hippocampal and cortical neurons(P<0.05). The interaction of Aβ25～35 and Apo E4 could also significantly enhance hippocampal and cortical neurons rest ［Ca2+］i andamplified KCl-induced rise in ［Ca2+］i in hippocampal and cortical neurons(P<0.05), but they had no synergic or additive effect.The frequency shift line widith Γ of both hippocampal and cortical neurons were decreased by both Aβ25-35 and ApoE4. CONCLUSION　Aβ25～35 and Apo E4 could enhance neuronal intracellular free Ca2+, amd decrease meirpma; ,e,brame f;iodotu. But their interaction had no synergic or additive effect. It suggested that the amplified effect of Aβ25～35 and Apo E4 on neuronal ［Ca2+］i and membane fluidity may be relative to their neurotoxity.

Through genetic recombination technique, the rat glial cell line-derived neurotrophic factor (rGDNF) cDNA was in-serted into polylinker site of retroviral vector pLXSN, to generate a recombinant plasmid pLXSN-GDNF as transfer vector. Therecombinant plasmid was verified with restriction analysis, PCR, dot blot hybridization and Southern blot hybridization. The re-sults showed that GDNF cDNA was cloned correctly into retroviral vector pLXSN, recombinant retroviral vector was construct-ed. It is concluded that the eukaryotic cell expression vector was constructed successfully for gene therapy of Parkinson's,Alzheimer's and other central nervous system diseases.

In order to investigate effect of basic fibroblast growth factor(bFGF) on the prolifiration and differentiation of theneural progenitor of embryonic hippocampus of rats in vitro, 25 ng/ml bFGF was employed into the serum-free medium of cultureof hippocampal neural cells of embryonic day 18 rats in the present study. The effect of bFGF on the viability of cells culturedwas detected by MTT colorimetric method and the effects of bFGF on proliferation and differentiation of hippocampal neural pro-genitors were analyzed qualitatively and quantitatively by means of immunochemistry, for the nestin, neurofilament, galactocere-broside and glial acidic fibrillary protein. The results showed that the OD value of experimental group was higher than that ofcontrol group by 1.5 and 1.8 times at 4 d and 8 d respectively. The quantitative analysis of each kinds of cells indicated that thenumber of neural progenitors, neurons and oligodendrocytes in experimental group were increased about 2 times as many as thatin control group, but no differences of astrocytes between the two groups at 4 d. However, the number of four kinds of cells aug-mented about 1.7 times at 8 d. The results of this study suggest that bFGF can not only promote the survival, proliferation, butalso facilitate the differentiation of neural progenitor of hippocampus to neurons and glial cells. To obtain more many purifiedneural progenitors in vitro, the embryonic day 18 is not an appropriate age. It is better to get younger embryo brain to culture and to add enough bFGF.

AIM To study the effects of A? 25～35 and Apo E4 on neuronal intracellular free Ca 2+ ([Ca 2+ ] i). METHODS Hippocampal and cortical neurons suspension of newborn(0～3 days) SD rats was produced. After incubated with fura 2/AM,the neurons suspension was divided into four groups: control, A? 25～35 , Apo E4, A? 25～35 +Apo E4. Each groups [Ca 2+ ] i was measured using a RF 5000 dual wavelength spectrofluorometer after incubated with double distilled water, A? 25～35 , Apo E4, A? 25～35 +Apo E4 for 3 min, respectively. The neurons outocorrelation function(ACF) of the scattering light intersity was analyzed by the microscope quasi elastic light scattering(MQLS) technique The frequency shift line width by ACF. The ? can sympolize the cell menbrane flilidity. RESULTS Both A? 25～35 and Apo E4 could significantly enhance hippocampal and cortical neurons rest [Ca 2+ ] i, furthermore, the effect of 5 ?mol?L -1 A? 25～35 was higher than the effect of 1 ?mol?L -1 A? 25～35 ( P

AIM: To clarify if TA9901, a natural antioxidants, could inhibit the formation of ?-amyloid(A?) fibril when A? 1-40 were injected into cerebral cortex of rat brain, and explore the mechanism of action of TA9901 on Alzheimer disesse. METHODS: Twelve Wistar rats (250-300 g) were randomly divided into four groups ( n=3 ). (1) control group; (2) TA9901 treatment group (ip. 100 mg?kg -1 ?d -1 ); (3) Vitamin E(VE) treatment group (ip. 100 mg?kg -1 ?d -1 ); (4) PBS group. 5 ?L 0.2% A? 1-40 was immediately injected into the right side of the deep cerebral cortex of control, TA9901 and VE group rats. The animals were sacrificed at the seventh day after the injection. The sections of the rat brain that contained the injected field were examined with transmission electron microscopy and Congo red staining with polarized microscopy. RESULTS: Many depositions of high electron density were observed by electron microscopy in the field where A? 1-40 was injected. They are intimately intermingled with macrophages and astrocytes. In the field, about 10nm fibrillar structures were observed that appeared similar to the fibrils seen in senile plaque (SP) of the brain of Alzheimer disease (AD). The fields in control and VE group contained richer A? fibrils than that in TA9901 group. After the sections stained with Congo red, A? 1-40 aggregation demonstrated intense birefringence under, indication the formation of amyloid fibrils. In TA9901 group, there was a weak birefringence.CONCLUSIONS: TA9901 can inhibit the fibril formation of A? that was injected into deep cerebral cortex of rat brain, this indicates primarily that TA9901 may be a potential therapeutic drug to interfere with the progression of amyloidgenesis in AD.

AIM: To investigate the pathological changes of motoneuron's function and morphology after root avulsion in order to study the neurobiology mechanism of motoneuron death. METHODS: Twenty female adult Sprague-Dawley rats, 200-300 g were used. The C 5-C 8, T 1 roots of the right brachial plexus were avulsed. All rats were killed 3 d, 5 d or 1 week after avulsion. One group of the C 5-C 8 spinal cords freeze sections (40 ?m thick) were collected for the NADPH-d histochemistry with neural red counterstained. Another group of the C 5-C 8 spinal cords freeze sections (40 ?m thick) were collected for the c-Jun immunocytochemistry stain. The paraffin sections (5 ?m thick) were collected for HE stain. The amount of NOS-positive and survival motoneurons was counted. The percentage of NOS expression and motoneuron survive were quantitatively analyzed considering the amount of contra lateral motoneurons as one hundred percent. RESULTS: The NOS expression rate was 0.74%?0.59% (3 d), 24.84%?6.73%(5 d), or 51.16%?8.67% (1 week), respectively. The survive rate was 93.00%?4.32% (3 d), 93.67%?5.27% (5 d), or 89.83%?2.65% (1 week), respectively. The motoneuron expressed c-Jun as early as 3 days after avulsion. The expression declined afterward until one week after avulsion. There was no significant change on the size of motoneuron. The nuclear membrane was still clear but some nuclei were not located in the middle of the cell body. There were some nucleoli with the chromatin condensation. CONCLUSION: The motoneuron NOS expression and cell death were increased within one week after spinal root avulsion. meanwhile, the c-jun expression was decreased. The NO/NOS may induce the motoneuron death by inhibiting the regenerating reactions of motoneuron after root avulsion injury.

AIM: To observe the humoral immune response in adult rhesus monkey induced by A? 1-15 vaccine. METHODS: 5 adult male rhesus monkeys were injected intramuscularly with A? 1-15 vac cine at baseline and at week 2, 6, 10, 14, 18, 22. The titer and IgG isotypes of the antibody against A? 1-42 in the serum were measured with ELISA. The specificity of the antibody against A? 1-42 was determined by Wester n blotting. The A? plaques in Tg2576 transgenic mouse brain were stained with t he antisera using immunohistochemistry method. RESULTS: At the eighth week after the vaccination, antibody against A? 1-42 bega n to develop significantly i n the serum. The titers of the antibody increased following vaccine boosted and reached 1: 3 840 at the twenty-fourth week, then decreased after the terminat ion o f inocunation. The IgG1 was accounted for the highest level in the antisera pool . The antibody against A? 1-42 showed high specificity. The A? plaques in Tg2576 transgenic mouse brain were labeled with the antisera. CONCLUSION: A? 1-15 vacci ne could induce vigorously specific humoral immune responses in adult rhesus mon key.