PRKCG mutation (SCA-14) causing a Ramsay Hunt phenotype.

Progressive myoclonic ataxia, also referred to as Ramsay Hunt syndrome, is characterized by a combination of myoclonus and cerebellar ataxia, infrequently accompanied by tonic-clonic seizures. Its differential diagnosis overlaps with progressive myoclonic epilepsy, a syndrome with myoclonus, tonic-clonic seizures, progressive ataxia and dementia. In patients with progressive myoclonic epilepsy, specific diseases can frequently be recognized, but the diagnostic yield in progressive myoclonic ataxia is much lower. We describe a patient who presented with multifocal myoclonus in his thirties and who later developed cerebellar ataxia and focal dystonia. His father was similarly affected. Genetic studies revealed a mutation in the protein kinase C gamma (PRKCG) gene, known to cause spinocerebellar ataxia type 14 (SCA-14). This case illustrates that both myoclonus and dystonia are part of the clinical spectrum in SCA-14 and that myoclonus can even be the presenting symptom. We suggest that SCA-14 should be considered in the differential diagnosis of progressive myoclonic ataxia.     

Management of status dystonicus: our experience and review of the literature.

Status dystonicus (SD) is a life threatening disorder that develops in patients with both primary and secondary dystonia, characterized by acute worsening of symptoms with generalized and severe muscle contractions. To date, no information is available on the best way to treat this disorder. We review the previously described cases of SD and two new cases are reported, one of which occurring in a child with static encephalopathy, and the other one in a patient with pantothenate kinase-associated neurodegeneration. Both patients were admitted to an intensive care unit and treated with midazolam and propofol. This approach proved to be useful in the former while the progressive nature of the dystonia of the second patient required the combination of intrathecal baclofen infusion and bilateral pallidal deep brain stimulation. We believe that a rapid and aggressive approach is justified to avoid the great morbidity and mortality which characterize SD. Our experience, combined with the data available in the literature, might permit to establish the best strategies in managing this rare and severe condition.     

脂质体介导的单纯疱疹胸苷激酶基因在人前列腺癌细胞中的表达

目的：提取并鉴定已构建的EB病毒表达载体pDR2-TK，利用脂质体介导的基因转染技术将pDR2-TK转染人前列腺癌细胞并对单纯疱疹胸苷激酶（HSV－TK）表达状况进行检测。方法：采用DNA大量制备及纯化系统提取pDR2-TK，酶切和DNA测序进行鉴定，采用阳离子脂质体法将pDR2-TK导入激素非依赖性人前列腺癌细胞系PC－3m，逆转录PCR（RT－PCR）法和SABC免疫组化法检测TK mRNA和蛋白的表达。结果：扩增提取的质粒经PstⅠ和EcoR Ⅴ酶切后各获得4个及2个片段，与原基因酶切图谱一致；所提取质粒PCR产物经DNA测序，与NCBI公布的HSV－TK基因序列对照，证实所提取质粒含目的基因序,旨质体法转染PC－3m细胞后，mRNA和蛋白均有HSV－TK的表达，其蛋白表达率约为22％。结论：pDR2-TK质粒含有目的的基因HSV－TK，阳离子脂质体法可将pDR2-TK导入人前列腺癌细胞并获得较高效率的表达。     

抗氧化剂对糖尿病大鼠肾小球蛋白激酶C的影响

目的　通过大鼠糖尿病模型 ,观察抗氧化剂对糖尿病大鼠肾小球蛋白激酶的影响。方法　将 75只雄性Wistar大鼠分为正常对照组、糖尿病未治疗组、抗氧化剂治疗组各 2 5只 ,共观察 8周 ,分别测定尿白蛋白排泄量(UAE) ,内生肌酣消除率 (Ccr)、血浆及肾脏组织一氧化氮 (NO)、一氧化氮合成酶 (NOS)、内皮素 (ET)和肾小球蛋白激酶C(proteinkinaseC ,PKC)。结果　给予维生素E治疗组 8周时 ,Ccr[(5 .2 8± 0 .5 4)ml/(min·kg) ]及尿白蛋白排泄量 [(14.2 7± 1.16 ) μg/2 4h]显著低于未治疗组 ,肾小球细胞膜PKC[(6 8.2 7± 12 .33) pmol/(min·mgprotein) ],2周时N0 [(34 .2 3± 3.91) μmol/L]及NOS[(32 .0 7± 3.76 )U/L]明显低于未治疗组 ,维生素E治疗组 2周时与 8周时的NO及NOS下降幅度明显小于未治疗组。结论　维生素E具有抑制PKC活性作用。     

蛋白激酶C激活调控FOS表达参与缺血诱导神经元凋亡的研究

目的：探讨蛋白激酶C（PKC）与神经元凋亡的可能机制，方法：采用大鼠全脑缺血模型，观察脑缺血／再灌流后PKC活性，FOS表达及神经元凋亡的变化。结果：脑缺血／再灌流可以导致PKC的移位激活伴FOS表达及神经元凋亡的增加；用蛋白激酶C抑制剂灯盏花可以阻止上述变化。结论：蛋白激酶C的激活可能通过促进FOS表达参与了脑缺血／再灌流诱导的神经元凋亡。     

Glucocorticoid regulation of eicosanoid production by glial cells under basal and stimulated conditions

We measured the production of two eicosanoids, prostaglandin E₂ and thromboxane-B₂, by rat glial cell cultures under basal conditions, following stimulation with phorbol-12-myristate-13-acetate and the bacterial endotoxin lipopolysaccharide, and following treatment with synthetic glucocorticoids. Stimulation of rat glial cells in culture with either phorbol-12-myristate-13-acetate or lipopolysaccharide caused a 1.5–5.0-fold increase in prostaglandin E₂ production, but did not affect thromboxane production. Pretreatment of the cultures with dexamethasone markedly inhibited the stimulated production of prostaglandin E₂ but had only a modest effect on basal production. Dexamethasone did not affect the activity of the enzyme protein kinase C, a putative regulator of eicosanoid synthesis. Our findings show that glucocorticoids have the potential to modulate central nervous system eicosanoid production particularly under conditions of stimulated production, such as inflammatory and demyelinating disorders. This mechanism may explain, at least in part, the therapeutic benefit of glucocorticoids in patients with multiple sclerosis.     

ERK信号传导通路调控乙醛刺激的肝星状细胞Na+/Ca2+泵mRNA表达的研究

目的 :探讨Erk信号传导通路调控乙醛刺激的肝星状细胞 (HSC)Na /Ca2 泵mRNA表达的影响。方法 :用链霉蛋白酶和胶原酶原位灌流 ,Metrizamide密度梯度离心分离大鼠肝星状细胞 ,采用RT PCR测定PD980 5 9阻断乙醛激活的肝星状细胞Erk活性后Na /Ca2 泵mRNA表达。结果 :乙醛刺激后 ,HSC后明显促进Na /Ca2 泵mRNA表达 (P<0 0 1) ,不同剂量PD980 5 9对肝星状细胞Na /Ca2 泵mRNA表达的影响无统计学意义。结论 :Erk信号传导通路可能对乙醛刺激的肝星状细胞激活状态的启动无明显影响     

三氧化二砷对人脐静脉内皮细胞中蛋白激酶C活性和白细胞介素-15分泌、表达的影响及其临床意义

目的 通过研究三氧化二砷(As2O3)对人脐静脉内皮细胞(HUVEC)中蛋白激酶C(PKC)活性和白细胞介素(IL)-15表达和分泌的影响,探讨内皮细胞在As2O3抑制白血病或肿瘤中的作用。方法用不同浓度的As2O3作用于培养的HUVEC细胞,测定其生长情况、胞膜和胞浆PKC活性以及对IL-15基因表达和分泌的影响。结果0.25 μmol／L~50 μmol／L的.As2O3均抑制HUVEC细胞的增殖(P<0.01),随着药物浓度或作用时间的增加,细胞逐渐死亡。在As2O3作用细胞4 h测定胞浆和胞膜的PKC活性,两者在不同浓度作用下活性水平均得到提升(P<0.01),但胞膜的活性上升幅度更大。在As2O3的测定浓度范围内,PKC的活性水平与As2O3的浓度呈正相关。1、5、16 μmol／L的As2O3导致IL-15基因表达和分泌水平的增加(P<0.01),并呈浓度依赖性关系。结论As2O3可能是通过激活内皮细胞的PKC活性,促进IL-15或其他细胞因子的分泌,来抑制白血病或肿瘤发展的。     

Growth factor pre-treatment differentially regulates phosphoinositide turnover downstream of lysophospholipid receptor and metabotropic glutamate receptors in cultured rat cerebrocortical astrocytes

Reactive gliosis is an aspect of neural plasticity and growth factor (GF) stimulation of astrocytes in vitro is widely regarded as a model system to study astrocyte plasticity. Astrocytes express receptors for several ligands including lysophosphatidic acid (LPA) and sphingosine-1-phosphate (S1P), agonists for the G-protein-coupled lysophospholipid receptors (lpRs). Activation of lpRs by LPA or S1P leads to multiple pharmacological effects including the influx of calcium, phosphoinositide (PI) hydrolysis, phosphorylation of extracellular receptor regulated kinase (ERK), release of arachidonic acid, and induces mitogenesis. Treatment of astrocytes in vitro with a growth factor cocktail (containing epidermal growth factor [EGF], basic fibroblast growth factor [bFGF] and insulin) led to a marked attenuation of lpR-induced PI hydrolysis. In contrast, under identical conditions, GF treatment led to marked potentiation of PI hydrolysis downstream of activation of another abundantly expressed G-protein coupled receptor, mGluR5. Quantitative gene expression analysis of GF-treated or control astrocytes by TaqMan RT-PCR indicated that GF treatment did not change gene expression of lpa1 and s1p1, but increased gene expression of s1p5 which is expressed at very low levels in basal conditions. These results suggest that GF differentially affected PLC activation downstream of mGluR5 versus lpR activation and that the changes in mRNA levels of lpRs do not account for marked attenuation of agonist-induced phosphoinositide turnover.