胞二磷胆碱对帕金森病模型中多巴胺能神经元的保护作用

目的 探讨胞二磷胆碱（citicoline,CC）对6-OHDA诱导的帕金森病体外细胞模型的神经保护作用机制.方法 MTT法检测细胞活力;采用Fluo3/AM通过流式细胞仪检测细胞内[Ca^2＋]i,采用罗丹明123检测线粒体膜电位（△ψm）.结果 2、1和0.1 mmol/L浓度的胞二磷胆碱,细胞活力与对照组比较明显增高（P＜0.01）,0.1 mmol/L组（P＜0.05）;1、0.1、0.01和0.001 mmol/L胞二磷胆碱能对抗由6-OHDA引起的多巴胺能神经元的损害,细胞活力高于6-OHDA组（P＜0.01）;胞二磷胆碱能对抗6-OHDA造成的细胞内[Ca^2＋]i增高及△ψm的下降（P＜0.01）;1 mmol/L胞二磷胆碱＋6-OHDA组△ψm高于对照组（P＜0.01）.结论 胞二磷胆碱通过保护神经元细胞膜,降低细胞内[Ca^2＋]i,提高线粒体膜电位,增强细胞活力,发挥其对多巴胺能神经元的保护作用.     

百草枯致小鼠帕金森病模型多巴胺能神经元损害作用的研究

目的 研究环境毒素百草枯(PQ)诱发帕金森病(PD)过程中多巴胺能神经元的损害和基质金属蛋白酶(MMP)-2、 MMP-9的表达规律.方法 C57BL小鼠按体重10 mg/kg经腹腔注射PQ,分别观察动物行为,高效液相法测定纹状体部多巴胺(DA)含量的变化.免疫组化染色法观察和计数黑质(SN)酪氨酸羟化酶(TH)阳性神经元的数量,免疫组化法观察术后不同时间点MMP-2、MMP-9的动态变化.结果 与对照组比较,模型组SN致密部TH阳性神经元数明显减少(P＜0.01),纹状体DA含量明显低于对照组(P＜0.01),MMP-2、 MMP-9的表达增强.结论 大剂量的PQ可使小鼠产生类似于PD的行为和DA能神经元的损害,MMP-2、 MMP-9可能参与了DA能神经元的损害过程.     

预防性绿茶多酚干预对帕金森病小鼠多巴胺能神经元的保护作用

目的探索预防性绿茶多酚(GTPs)干预对MPTP诱导的帕金森病(PD)小鼠黑质多巴胺能神经元保护作用及机制。方法采用C57BL/6J老年小鼠共60只,分为空白对照组、预防组、神经毒素1-甲基-4苯基-1,2,3,6-四氢吡啶(MPTP)组和治疗组(n=15)。后三组分别给予MPTP建立模型和绿茶多酚干预后免疫组化法观察黑质多巴胺能神经元数量,比色法观察中脑氧化应激水平。结果预防组、MPTP组和治疗组黑质多巴胺能神经元数量显著减少(P<0.01),氧化应激水平明显升高(P<0.01),但变化幅度预防组<治疗组相似文献   

三七总皂甙对神经干细胞诱导分化多巴胺能神经元移植帕金森病大鼠的影响研究

目的 探讨三七总皂甙对神经干细胞体外诱导分化多巴胺能神经元移植帕金森病(PD)大鼠后移植细胞的存活及移植疗效的影响.方法 大鼠胚胎中脑神经干细胞经传代扩增后,在分化液中诱导向多巴胺能神经元分化,应用6-羟基多巴胺制备的PD大鼠模型随机分为多巴胺能神经元组、多巴胺能神经元 三七总皂甙组、三七总皂甙组及手术对照组,每组8只,进行移植手术,移植后检测PD大鼠不对称旋转行为的变化及纹状体移植区酪氨酸羟化酶染色阳性细胞存活的情况.结果 与手术对照组比较,移植后20 d多巴胺能神经元组大鼠不对称旋转圈数开始明显下降(P＜0.01).移植后10～60 d,多巴胺能神经元 三七总皂甙组大鼠的不对称旋转圈数明显低于多巴胺能神经元组(P＜0.01).免疫组织化学染色显示多巴胺能神经元 三七总皂甙组大鼠纹状体移植区酪氨酸羟化酶染色阳性细胞数明显多于多巴胺能神经元组(P＜0.01).结论 三七总皂甙具有提高神经干细胞诱导分化的多巴胺能神经元移植PD大鼠后移植细胞的存活率及移植疗效的作用.     

人GDNFcDNA在SH—SY5Y细胞中的表达及其对多巴胺能神经元的保护作用探讨

为建立一种可分泌人胶质细胞源性神经营养因子（GDNF）的工程细胞,研究其在帕金森病基因治疗中的可能作用。克隆携带Kozak序列的人GDNFcDNA,并转染至人类神经母细胞瘤细胞系SH－SY5Y细胞,将此工程细胞与大鼠原代多巴胺能神经元共培养,免疫组化检测多巴胺能神经元。发现工程细胞可防止多巴胺能神经元退变死亡,有助于多巴胺能神经元抵抗MPP^ 的毒性损伤。表明可分泌人GDNF的工程细胞在帕金森病基因治疗中可能具有重要的应用价值。     

调控Nurr1表达影响神经干细胞向多巴胺能神经元分化的研究进展

帕金森病（PD）是一种进行性加重的慢性中枢神经系统功能失调所致一系列退行性病变,主要表现为中脑黑质多巴胺（DA）能神经元分泌减少引起的震颤、僵直、运动迟缓等运动障碍及非运动障碍。传统的药物疗法是在短期内补充DA,可缓解症状;其中左旋多巴是治疗PD的首选药物,但长期服用患者会出现精神症状、开关现象、剂末现象和晨僵少动等不良反应^[1]。最新研究^[2]显示,神经干细胞（NSC）移植术有望达到治疗PD运动障碍的目的。     

脂多糖对多巴胺能神经元的损毁作用

目的离体、在体水平分别观察脂多糖（LPS）对多巴胺（DA）能神经元的毁损作用，及其对动物行为的影响。方法将LPS、6-羟基多巴胺（6-OHDA）和LPS与小胶质细胞共培养的上清液分别加入大鼠嗜铬细胞瘤（PC12）细胞中，四唑盐比色试验（MTT）观察一定时间内细胞活性的变化；将LPS注入大鼠单侧黑质，在一定时间内，观察动物行为的变化；免疫组化法检测黑质区DA能神经元数目，高压液相色谱（HPLC）洲定黑质纹状体系统DA等及其代谢产物含量。结果LPS对PCI2细胞活性无直接影响，LPS与小胶质细胞共培养组和60HDA组则对PC12细胞活性有明显影响，使细胞活性分别下降26％和30％；大鼠单侧黑质注入LPS后21、28d，阿朴吗啡诱发大鼠出现旋转行为，转次为4～6次／min；注射侧黑质TH阳性细胞数减少约35％～60％，尤以21、28d明显；LPS注射后14、21d和28d大鼠的纹状体和黑质DA及其代谢物含量降低30％～70％。结论LPS间接地对DA能神经元产生一定的损毁作用，并可导致大鼠偏侧旋转行为的发生。     

胶质细胞源性神经营养因子对帕金森病大鼠多巴胺能神经元的修复作用

目的观察向脑室或壳核内直接注射胶质细胞源性神经营养因子（GDNF）对帕金森病大鼠黑质纹状体系统多巴胺能神经元的修复作用。方法 70只大鼠,于右侧前脑内侧束（MFB）及腹侧被盖区（VTA）分别注射12μg 6-OHDA,观察2周获得39只帕金森病模型大鼠。其中15只大鼠（观察A组）脑室内注射人重组GDNF,14只（观察B组）壳核内注射人重组GDNF,5只（对照A组）脑室内注射赋形剂,5只（对照B组）壳核内注射赋形剂。采用免疫组化和量化形态学分析方法测算酪氨酸羟化酶阳性（TH＋）神经元数目、大小及TH＋纤维密度。结果对照A、B组大鼠右侧中脑组织黑质TH＋多巴胺能神经元大小和数目及纹状体内侧部TH＋神经纤维密度均较左侧降低,P均〈0.05。观察A组与对照A组相比、观察B组与对照B组相比,双侧中脑组织黑质TH＋多巴胺能神经元大小和数目及纹状体内侧部TH＋神经纤维密度均明显升高,P均〈0.05。结论脑室或壳核内直接注射GDNF对帕金森病大鼠黑质纹状体系统多巴胺能神经元损伤有修复作用。     

羊膜细胞移植对帕金森病鼠纹状体中多巴胺神经元的促再生作用

目的：探讨羊膜细胞移植治疗帕金森病（PD）的作用机制。方法：通过6－羟基多巴胺（6－OHAD）立体定向注射破坏－侧黑质,制成PD大鼠模型,然后将鼠成活羊膜细胞悬液植入受损侧纹状体,并与死羊膜细胞移植及生理盐水假移植对照,结果：活羊膜细胞移植可减少大鼠的异常旋转行为,尤其有意义的是在活羊膜细胞移植靶点周围出现了来源于宿主的酪氨酸羟化酶（TH）阳性神经纤维,结论：活羊膜细胞移植能够增加PD鼠纹状体中多巴胺（DA）神经纤维的数目,到底是纹状体残存多巴胺神经元的再生,还是羊膜细胞分泌的营养因子激活了脑的内神经干细胞的生长还有待进一步研究。     

多巴胺能受体激动剂治疗研究进展

帕金森病的治疗程序首先应确保帕金森病的诊断明确，一旦诊断确定后，首先应考虑用神经保护剂，如司来吉兰。针对帕金森病的初期症状，可先使用多巴胺能受体激动剂，若单用多巴胺能受体激动剂疗效差，则考虑加用左旋多巴。如果欲延长左旋多巴作用的半衰期，可考虑合并使用儿茶酚氧位一甲基转移酶抑制剂。最后，若出现运动并发     

Ethanol Effects on Dopaminergic "Reward" Neurons in the Ventral Tegmental Area and the Mesolimbic Pathway

Dopaminergic (DA) neurons in the ventral tegmental area (VTA) provide the DA innervation of the nucleus accumbens. This mesolimbic DA pathway is important for the reinforcing effects of alcohol and plays a central role in alcohol‐related behaviors. This Research Society on Alcoholism symposium included a discussion of the acute and chronic effects of ethanol and ethanol withdrawal on DA VTA neurons. The experiments that were discussed ranged from studies in the freely moving behaving rat and electrophysiological studies in vivo, to electrophysiological studies in brain slices and acutely dissociated DA VTA neurons, to neurochemical studies that explored the cellular basis of ethanol's actions. Because ethanol's effects on this reinforcement pathway are critically important for voluntary intake of alcohol and alcohol addiction, this symposium report may be of interest to both basic science and clinical researchers in the alcohol field. This symposium focused on effects of ethanol on the mesolimbic dopamine pathway, specifically the VTA and the nucleus accumbens. The organizer/co‐chairs were Sarah B. Appel and Mark S. Brodie. The presentations were (1) Introduction, by Mark S. Brodie; (2) Reinforcing Actions of Alcohol in the Ventral Tegmental Area: Intracranial Self‐Administration Studies, by William J. McBride; (3) A Possible Mechanism Mediating the Direct Excitation of Dopaminergic Ventral Tegmental Area Neurons by Ethanol, by Sarah B. Appel; (4) Effect of Chronic Ethanol and Withdrawal on Dopaminergic Ventral Tegmental Area Neurons: In Vivo Electrophysiological Studies, by Marco Diana; (5) Ethanol Induces Protein Kinase A Translocation Into the Nucleus, Cyclic AMP Response Element Binding Protein Phosphorylation, and Increases in Cyclic Adenosine Monophosphate–Dependent Gene Expression, by Ivan Diamond; and (6) Co‐activation of Dopamine D₁ and D₂ Receptors Is Necessary for Dopamine‐Mediated Increases in Firing Activity in Nucleus Accumbens Neurons, by Antonello Bonci.     

The Effects of Ethanol on Dopaminergic Neurons of the Ventral Tegmental Area Studied with Intracellular Recording in Brain Slices

Dopaminergic neurons in the ventral tegmental area of Tsai (VTA) have been implicated in the mediation of the rewarding effects of ethanol and many other drugs of abuse. Our previous extracellular studies in brain slices have demonstrated that ethanol increases the firing rate of dopaminergic neurons in the VTA. In the present intracellular study, ethanol (40–160 mM) increased the spontaneous firing rate of most (77%) VTA neurons. In addition, most (75%) VTA neurons were depolarized by ethanol. Ethanol also changed the shape of the spontaneous action potential in VTA neurons, reducing the amplitude of the spike after-hyperpolarization (in 74% of neurons) and also reducing the amplitude of the depolarizing phase of the action potential (in 86% of neurons tested). Furthermore, analysis of Voltage/ Current curves in the presence and absence of ethanol showed that ethanol had little effect on the resistance of the cell membrane at membrane potentials near rest, but enhanced the time-dependent inward rectification activated at more hyperpolarized membrane potentials (I_h). This intracellular study identifies several electrophysiological effects of ethanol that may underlie the ethanol-induced excitation of VTA neurons and, therefore, may be important for the rewarding effects of ethanol.     

Uric Acid as a Factor in the Metabolic Syndrome

Hyperuricemia is a prevalent finding in patients presenting metabolic syndrome, although its clinical meaning is still controversial and often underestimated. Men and women have different serum urate levels at all ages, and the impact of hyperuricemia in cardiovascular and renal outcomes is generally associated with a worse prognosis in women. Recent studies also have called attention to another perspective on hyperuricemia, indicating that it may be not only a consequence of insulin resistance states but also a significant predictor of the development of metabolic syndrome. This review discusses recent evidence related to the clinical significance of hyperuricemia in both sexes and the potential benefits of lowering serum uric acid levels.     

Regulation of Uric Acid Excretion by the Kidney

It has been known for many years that the kidney plays a major role in uric acid homeostasis, as more than 70% of urate excretion is renal. Furthermore, hyperuricemia in gout is most commonly the result of relative urate underexcretion, as the kidney has enormous capacity for urate reabsorption. A clear understanding of the mechanisms of renal handling of urate has been hampered by the differences between humans and animal models. The power of human genetics and genome-wide association studies has now provided new insight into the molecular mechanisms of urate transport by identifying the transporters that have critical roles in urate transport. This review surveys the new evidence for a molecular model of urate transport in the renal proximal tubule and uses these data to refute the popular four-component model for urate transport that has long been in vogue. It also discusses data that help us understand the relation of diuretics to hyperuricemia, losartan-induced uricosuria, variations in uric acid levels in hyperglycemia, and the effects of dairy diets on serum urate levels. In the end, several of these clinical findings are explained, and the remaining gaps in our knowledge will become evident.     

Prognostic Significance of Serum Uric Acid in Patients Admitted to the Department of Medicine

BackgroundHyperuricemia has been linked to proatherogenic processes, including increased oxidative stress and leukocyte activation, and was shown to predict adverse prognosis in heart failure, renal failure, and hypertension. Recently, serum uric acid (SUA) was shown to be an independent predictor of long-term mortality in patients with cardiovascular diseases. However, the prognostic significance of SUA for the short-term outcome of admitted medical patients is unknown.MethodsInitial SUA, together with epidemiological, clinical, and laboratory data, was analyzed for a prospective cohort of 650 consecutive adult patients admitted to the department of internal medicine during a 3-month period.ResultsThe mean, median, and range of SUA at admission were 6.1 ± 2.7, 5.6, and 1.2 to 24 mg/dL, respectively. Increased SUA was significantly correlated with age, gender, comorbidities (coronary heart disease, heart failure, hypertension, diabetes, renal failure, and gout), use of diuretics, and current admission for cardiovascular diseases but not with current diagnosis of infection, malignancy, or inflammatory diseases, nor with C-reactive protein. However, SUA significantly correlated with mortality (7.7 versus 6 mg/L, P < 0.025) and was an independent predictor of mortality in a multivariate regression analysis (odds ratio: 1.11; confidence interval: 1.003-1.218; P = 0.04), with a significant difference in mortality between normal SUA (< 6 mg/dL) with 5% mortality and high SUA (> 12 mg/dL) with 27% mortality.ConclusionsInitial SUA is an independent predictor of mortality in admitted medical patients. Whether significant asymptomatic hyperuricemia should be treated remains to be determined in further studies.     

Uric Acid Excretion in Patients with Malignant Lymphomas

Uric acid blood and urine studies were performed in 12 patients withlymphomas while on a measured low purine diet before, during and after cytotoxictherapy.

Before treatment, urinary uric acid excretion in these patients was significantlyhigher than in normal subjects, although only 2 patients had clearlyelevated blood uric acid levels. There was no correlation between the estimatedsize of the tumor masses and pretreatment uric acid excretion. The responseto treatment could not have been predicted by measurement of thepretreatment uric acid excretion.

In one patient with extensive tumor infiltration of the kidneys, dangerousrenal failure, preceded by marked hyperuricemia, developed during therapy.Mechanical hemodialysis resulted in clinical improvement and marked reductionin the blood levels of uric acid and urea.

The finding of a large increase in uric acid excretion during the early daysof treatment of a patient with lymphoma is indicative of a responsive tumor.Such data also serve as warning of potential obstructive uric acid nephropathyor uropathy before major increases in serum uric acid appear. Small increasesof uric acid excretion in association with treatment could not be correlatedwith objective clinical response.

Accepted on April 3, 1961     

帕金森病伴认知功能障碍与血尿酸、同型半胱氨酸相关性的研究进展

帕金森病(Parkinson's disease,PD)是中老年人常见的一种慢性中枢神经系统变性疾病.其发病过程隐蔽,一旦出现临床症状,病情已进人中晚期,故PD的早期临床诊断较困难.认知功能障碍(mild cognitive impairment,MCI)是介于健康和轻度痴呆之间的不稳定的转化过渡状态,具有转化为痴呆的高风险.本文探讨帕金森病患者的血尿酸、血浆同型半胱氨酸(Hcy)水平,分析其与认知功能的相关性,探讨非痴呆PD患者认知功能的相关影响因素.因此,在轻度认知功能障碍的PD患者积极寻找对疾病进行有效干预的因素,在发生不可逆脑损伤前进行临床干预,对有效延缓疾病进展具有重要意义.