Objective To examine the effect of simvastatin treatment on Parkinson's disease rats induced by lipopolysaccharide (LPS) and its mechanism.Methods The LPS-PD model was established by injection of LPS (5 mg/mL) into the right substantia nigra compacta (SNC),and rats were randomly divided into control group,LPS-model group and simvastatin treatment group with 15 rats in each group.Rats in the simvastatin treatment group was intraperitoneally administered simvastatin (5 mg/kg) before,and daily for 14 days after surgery,while the control group and LPS-model group received same volume normal saline and LPS respectively.Ionized calcium binding adaptor molecule 1 (Iba-1)-positive cells and the expression of tyrosine hydroxylase (TH),tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) in the SNC were detected by immunohistochemistry,Western blotting and enzyme-linked immunosorbent assay,respectively.The effect of simvastatin in the PD model was also examined in behavioral tests.Results The LPS-model group exhibited typical animal PD behaviors.Compared with the control group,the LPS-model group exhibited a decreased number of DA neurons,and comparison of the intact side to reduce 81.13％ (P＜0.01) in the SNC,as well as increases in the Iba-1-positive cell number,iNOS,IL-1β and TNF-α expression (P＜0.05).These effects were inhibited by simvastatin treatment (P＜0.05).Conclusion Simvastatin mediates a protective effect on dopaminergic neurons in the SNC in the LPS-PD model,possibly by inhibiting glial cells (astrocytes and microglia) activation,and playing an anti-inflammatory role,thus improving substantia nigra function.

Objective To further investigate clinical manifestations and management for thallium poisoning. Methods Clinical data of 6 patients who were hospitalized in Union Hospital of Tongji Medical College in May 2008 with diagnosis of acute or chronic thallium poisoning,were retrospectively analyzed.Results Six patients (4 male and 2 female) ,aged from 12 to 50,came from one family (two sisters with their husbands and sons). Five of them (3 acute and 2 chronic,for the second time in half a year,thallium poisoning) initiated with peripheral neuritis,represented with severe burning pain,numbness,paresthesia in the lower limbs,accompanied with or without gastrointestinal symptoms. A 12 year-old boy with obviously elevated urinary thallium concentration was asymptomatic. Blood and urinary thallium concentrations of the patients were determined by atomic absorption spectrophotometry and were all significantly elevated.Treatment was initiated using potassium supplementation,diuresis,oral laxatives,Prussian blue and intramuscular injection of dimercaptopropansulfonate sodium.Meanwhile two of them were treated with hemoperfusion. Finally,two of them recovered,another two were transferred to a specialized hospital for continuous treatment,and the rest two deteriorated rapidly with occurrence of unconsciousness and died of multiple organ failure. Conclusions The main clinical manifestations of thallium poisoning are multiple peripheral neuritis,gastrointestinal symptoms and dermatological changes. In order to avoid missed diagnosis and misdiagnosis,a high suspicion should be arose for thallium poisoning when a patient suffering from the above symptoms.Prussian blue was considered traditionally as an effective therapeutic strategy for the condition,and hemoperfusion may be a more effective treatment for acute thallium poisoning.

Objective To investigate the role of the extracellular signal-regulated kinases 1 and 2 (ERK1/2) in rotenone-mediated dopaminergic cell damage. Methods Neuronal rat adrenal pheochromecytoma(PC12) cells treated with rotenone were used as the cell model of Parkinson' s disease (PD). Cell viability of PC12 cells after exposure to rotenone was detected by MTT (methyl thiazolyl tetrazolium) method. Immanohistechemistry was used to detect the phosphorylation of ERK1/2 in cells exposed to rotenone. Western blotting was used to verify the phosphorylation of ERK1/2 and to observe the effect of PD98059, an inhibitor of the upstream mitogen activated protein kinase kinase (MEK) that phosphorylates and activates ERK1/2, on rotenone-induced ERK1/2 phosphorylation and cell viability.Results The viability (represented by A570 of PC12 cells exposed to 5 μmoL/L rotenone) declined with the increase of exposure time from 1 h to 24 h (%, 1 h :75.46±5.47, 2 h : 70.42±1.94, 4 h : 65.23± 0.96, 8 h : 59.04 ± 2.85, 24 h :29.64 ± 1.63, comparison between different time points(F=143.014, P=0.000) ; compared with control groups(100.00±2.89), q value: 17.07, 20.58, 24. 19, 28.50, 48.95 respectively, all P <0.01). After exposure to rotenone, phosphorylated ERK1/2 aggregated in the PC12 cells. Western blotting indicated that rotenone induced a biphasic phosphorylation of ERK1/2, which increased from 30 min after rotenone treatment, reached the peak at 1-2 h, decreased at 4 h, and increased again at 8 h, and disappeared after 16 h; PD98059 significantly inhibited ERK1/2 phosphorylation induced by rotenone, and attenuated cell injury examined at 1, 2 and 8 h. Conclusions Our study suggested that ERK1/2 activation plays a detrimental role in rotenone toxicity, and raised the possibility that abnormal patterns of ERK1/2 activation may contribute to dopaminergic neuronal cell death in PD.

In order to study neurotransmitter receptor regulation in the basal ganglia involved in the functional changes underlying levodopa-induced motor complications, quantitative autoradiography was used to observe receptor bindings of dopamine D1 and D2, N-methyl-D-aspartate (NMDA), amino-3-hydroxy-5-methylisoxazole propionic acid (AMPA) and amino butyric acid (GABA) in the basal ganglia of rats that had unilateral nigrostriatal lesions and had been chronically treated with levodopa until motor complications developed. The rats were randomly assigned to three groups: normal, denervated and treatment-complicated groups. The results showed that response duration to levodopa became progressively shorter and abnormal involuntary movement (AIM) score was progressively increased during the course of levodopa treatment. Chronic treatment augmented D1 receptors more than denervation, and reduced D2 receptors that were also increased by dopamine denervation. Striatal NMDA receptors were substantially up-regulated in the treatment-complicated group. Levodopa treatment did not change receptors of nigral AMPA, pallidal GABA, and subthalamic GABA, which remained the same as that in denervation group. However, chronic treatment reversed the increase of nigral GABA receptors caused by the lesion. It was concluded that a shortening of response duration and AIM mimicked levodopa-induced motor complications of Parkinson's patients. These data suggested that up-regulation of dopamine D1 and NMDA receptors in the striatum leads to an imbalance of stimulation through the striatal output pathways, which is associated with levodopa-induced motor complications.

This study investigated the effect and mechanism of cell cycle reentry induced by 6-hydrodopamine (6-OHDA) in PCI2 cells.By using neural differentiated PCI2 cells treated with 6-OHDA,the apoptosis model of dopaminergic neurons was established.Cell viability was measured by MTT.Cell apoptosis and the distribution of cell cycle were assessed by flow cytometry.Western blot was used to detect the activation of extracellular regulator kinasel/2 (ERK1/2) pathway and the phosphorylation of retinoblastoma protein (RB).Our results showed that after PC12 cells were treated wtih 6-OHDA,the viability of PC12 cells was declined in a concentration-dependent manner.Flow cytometry revealed that 6-OHDA could increase the apoptosis ratio of PC12 cells in a time-dependent manner.The percentage of cells in G0/G1 phase of cell cycle was decreased and that in S phase and G2/M phase increased.Simultaneously,ERK1/2 pathway was activated and phos- phorylated RB increased.It was concluded that 6-OHDA could induce cell cycle reentry of dopa-minergic neurons through the activation of ERK1/2 pathway and RB phosphorylation.The aberrant cell cycle reentry contributes to the apoptosis of dopaminergic neurons.

In order to study neurotransmitter receptor regulation in the basal ganglia involved in the functional changes underlying levodopa-induced motor complications,quantitative autoradiography was used to observe receptor bindings of dopamine D1 and D2,N-methyl-D-aspartate (NMDA),amino-3-hydroxy-5-methylisoxazole propionic acid (AMPA) and amino butyric acid (GABA) in the basal ganglia of rats that had unilateral nigrostriatal lesions and had been chronically treated with levodopa until motor complications developed.The rats were randomly assigned to three groups:normal,denervated and treatment-complicated groups.The results showed that response duration to levodopa became progressively shorter and abnormal involuntary movement (AIM) score was progressively increased during the course of levodopa treatment.Chronic treatment augmented DI receptors more than denervation,and reduced D2 receptors that were also increased by dopamine denervation.Striatal NMDA receptors were substantially up-regulated in the treatment-complicated group.Levodopa treatment did not change receptors of nigral AMPA,pailidai GABA,and subthalamic GABA,which remained the same as that in denervation group.However,chronic treatment reversed the increase ofnigral GABA receptors caused by the lesion.It was concluded that a shortening of response duration and AIM mimicked levodopa-induced motor complications of Parkinson's patients.These data suggested that up-regulation of dopamine D1 and NMDA receptors in the striatum leads to an imbalance of stimulation through the striatal output pathways,which is associated with levodopa-induced motor complications.

BACKGROUND: Mainly pathological changes of Parkinson disease (PD)are related to irreversible degeneration and reduction of dopamine neurons of substantia nigra in midbrain; however, oxidative stress reaction plays an important role in onset of PD. 3-nitropropionie acid (3-NP) is an inhibitor of mitochondria compound I, and it can inhibit oxidative phosphorylation so as to restrain energy metabolism. However, professor Riepe from Germany found that small dose of 3-NP can increase the tolerance of neurons to ischemic hypoxia. It is unclear whether it can also strengthen the tolerance of dopamine neurons to neurotoxin.OBJECTIVE: To investigate the possible mechanism and prevention of repetitively preconditioning 3-NP for treating PD.DESIGN: Controlled observational animal study. SETTING: Department of Neurology, Union Hospital affiliated to TongjiMedical College, Huazhong University of Science and Technology. MATERIALS: The experiment was carried out at the Neurological Lab oratory, Union Hospital affiliated to Tongji Medical College, Huazhong U niversity of Science and Technology from March to July 2004. A total of48 C57BL mice, weighing 18-20 g, aged 2-3 months, of both genders, were randomly divided into 6 groups with 8 in each group. ① Blank con trol group: Mice were not medicated. ② 3-NP single administrationgroup: Mice were intraperitoneally injected with 3-NP once. ③ 3-NPrepetitively administrations group: Mice were intraperitoneally injectedwith 3-NP every 5 days for 5 times in total. ④ Neurotoxin group: Micewere intraperitoneally injected with neurotoxin once every day for 5 timesin total. ⑤ 3-NP single preconditioning group: Mice were intraperitoneal ly injected with 3-NP once, and 3 days later, they were intraperitoneallyinjected with neurotoxin once every day for 5 times in total. ⑥ 3-NPrepetitively preconditionings group: Mice were intraperitoneally injectedwith 3-NP and repetitively every 5 days for 5 times in total; 3 days later, mice were intraperitoneally injected with neurotoxin once every day for5 times in total. Dosages of 3-NP and neurotoxin were 20 mg/kg and30 mg/kg, respectively. METHODS: Motor coordination of mice was scored with pole test andtraction test before experiment and at 3 days after the last injection ofneurotoxin. Three days after complete injection, mice were sacrificed rapid ly to measure the contents of malondialdehyde (MDA) and reduced glu tathione (GSH) in the substantia nigra of midbrain. MAIN OUTCOME MEASURES: ① Motor and behavior scores; ② con tent of MDA; ③ content of GSH.~ULTS: All 48 mice were involved in the final analysis. ① Scores of pole test and traction test were decreased in neurotoxin group as compared with those in control group (P＜0.01); but the scores were increased after 3-NP single/repetitively preconditionings, and there were significant difference (P＜0.05, P＜0.01). Meanwhile, there was also significant differencebetween 3-NP repetitively preconditionings group and 3-NP single preconditioning group (P＜0.05). ② Content of MDA was increased in neurotoxin group as compared with that in control group, and there was significant difference (P＜0.01); content of MDA was decreased after 3-NP single preconditioning as compared with that in neurotoxin group, and there was significant difference (P＜0.05); content of MDA was remarkably decreased after 3-NP repetitively preconditionings as compared with that in neurotoxin group, and there was greatly significant difference (P＜0.01); meanwhile, there was also significant difference between 3-NP repetitively preconditionings group and 3-NP single preconditioning group (P＜0.05). ③As compared with that in blank control group, content GSH in 3-NP single administration group was not changed; content of GSH in 3-NP repetitively administrations group was increased (P＜0.05); content of GSH in neurotoxin group was decreased as compared with that in blank control group (P＜0.01); content of GSH in 3-NP single preconditioning group was not changed as compared with that in neurotoxin group (P＞0.05); content of GSH was increased after 3-NP repetitively preconditionings, and there was significant difference (P＜0.05); meanwhile, there was significant difference between 3-NP repetitively preconditionings group and 3-NP single preconditioning group (P＜0.05).CONCLUSION: 3-NP repetitively preconditionings can activate synthesis of GSH, protect dopamine neurons through decreasing production of MDA.

The effects of antisense FosB and CREB intra-striatum injection on the expression of prodynorphin (PDyn) gene in striatal neurons of Levodopa-induced dyskinesias (LID) rats with Parkinson disease (PD) were explored. PD model in rats was established by 6-OHDA microinjection stereotaxically. The rats were treated with chronic intermittent Levodopa celiac injection for 28 days to get the LID rats. Antisense FosB and cAMP response element-binding protein (CREB) were injected into striatum of all rats respectively. In situ hybridization was used to measure the changes in the expression of PDyn mRNA in striatum and behavior changes were observed. The results showed after administration of antisense FosB, abnormal involuntary movement (AIM) was decreased and the expression of PDyn mRNA in striatum was increased in LID rats as compared with sense FosB group (P<0.01, respectively). As compared with the control group, the expression of PDyn mRNA in striatum was decreased by antisense CREB-treated LID group (P<0.01) and compared with sense CREB treated LID group, antisense CREB-treated LID group showed no changes in AIM scores and the expressions of PDyn mRNA (both P>0.05). In conclusion, FosB protein, which replaced the CREG, could regulate the expression of PDyn mRNA and play critical role in the pathogenesis of LID.

The effects of antisense FosB and CREB intra-striatum injection on the expression of prodynorphin (PDyn) gene in striatal neurons of Levodopa-induced dyskinesias (LID) rats with Parkinson disease (PD) were explored. PD model in rats was established by 6-OHDA microinjection stereotaxically. The rats were treated with chronic intermittent Levodopa celiac injection for 28 days to get the LID rats. Antisense FosB and cAMP response element-binding protein (CREB) were injected into striatum of all rats respectively. In situ hybridization was used to measure the changes in the expression of PDyn mRNA in striatum and behavior changes were observed. The results showed after administration of antisense FosB, abnormal involuntary movement (AIM) was decreased and the expression of PDyn mRNA in striatum was increased in LID rats as compared with sense FosB group (P＜0.01, respectively). As compared with the control group, the expression of PDyn mRNA in striatum was decreased by antisense CREB-treated LID group (P＜0.01) and compared with sense CREB treated LID group, antisense CREB-treated LID group showed no changes in AIM scores and the expressions of PDyn mRNA (both P＞0.05). In conclusion, FosB protein, which replaced the CREG,could regulate the expression of PDyn mRNA and play critical role in the pathogenesis of LID.

BACKGROUND: It is recently found that some kinds of antibiotics can aggravate the obstruction of neuromuscular junction(NM J) transmission,exacerbate myasthenia gravis (MG). Hitherto, there are few reports about the effect of antibiotics on transitive function on animal models. Along with the appearance of new antibiotics, the effects of the antibiotics on NMJ transitive function need to be further observed.OBJECTIVE: To investigate the effect of aminoglycoside antibiotics, fluoroquinolone antibiotics and cephalosporin antibiotics on the transitive function of NMJ in MG, and to provide an experimental basis for using those antibiotics securely in clinic and for selecting those antibiotics to treat MG properly.DESIGN: Randomized controlled study based on experimental animals.SETTING: Department of nosocomial infection, neurology and pharmacy in a university hospital.MATERIALS: The experiment was conducted at the Neurological Institute of Tongji Medical College, Huazhong University of Science and Technology from March 2002 to January 2003. Totally 150 healthy female C57BL/6mice, 6 - 8 weeks old, weighting 18 - 20 g, were divided randomly into 4groups: normal group( n = 10), MG group( n = 10), saline group( n = 10)and antibiotics group( n = 120) . Mice in antibiotics group were divided randomly again into gentamicin group, etimicin group, ciprofloxacin group,fleroxacin group, cefuroxime group and cephradine group, with 20 mice in each group.INTERVENTIONS: C57BL/6 mice were immunized with the acetylcholine receptor(AChR) protein in complete Fruend' s adjuvant(CFA) to establish experimental autoimmune myasthenia gravis(EAMG) . Mice in saline group were injected normal saline and mice in antibiotics group were injected antibiotics(10 mg/kg), lasted 14 days. Mice in MG group were without any treatments. On the 7th day after the last immunization and the 14th day after the antibiotics treatments, MG scores was evaluated, repetitive nerve stimulation(RNS) and the levels of acetylcholine receptor antibody(AChRab)were tested at the same time.RESULTS; The mean symptom scores on the 14th day after the antibiotics treatment with gentamicin, etimicin, ciprofloxacin and fleroxacin were higher than that in MG group, and there was no significant difference in the mean symptom scores among cefuroxime group, cephradine group and MG group. The decrement percent of RNS in gentamicin group [ (21.22 ± 4.63)% ], etimicin group[ (19.08 ±4. 25)% ], ciprofloxacin group[ (22.25 ±4.95)% ] and fleroxacin group[ (21.71 ±4.99)% ] were higher than that in MG group[(15.75 ±2.22)% ], but no difference was found in the attenuation rate among cefuroxime group[(15.25 ±2. 87)% ],cephradine group[ ( 15.25 ± 3.30)% ] and MG group. The levels of AChRab in gentamicin, etimicin, ciprofloxacin and fleroxacin groups were also higher than that in MG group, but no difference was found among cefuroxime group, cephradine group and MG group.CONCLUSOIN: Aminoglycoside and fluoroquinolone antibiotics can aggravate the obstruction of NMJ transmission, and cephalosporin antibiotics have no obvious effect on the obstruction of NMJ transmission function in MG.