低钾型周期性麻痹79例临床分析

低钾型周期性麻痹是常染色体显性遗传性钙通道病,是以反复发作的骨骼肌驰缓性瘫痪和低血钾为特征的常见疾病。严重的低钾型周期性麻痹可出现呼吸肌麻痹及心律紊乱,致呼吸停止,昏迷及心搏骤停,是急诊常见的疾病,现将我院收治的79例低钾型周期性麻痹患者的资料分析报告如下。1临床资料1·1一般资料79例低钾型周期性麻痹患者中,男61例,年龄17~60岁,平均(35·6±6·1)岁;女18例,年龄16~58岁,平均(33·6±6·1)岁。男女比例3·4∶1,首次发病40例(50·6%),2次或2次以上发病39例(49·4%)。合并甲亢34例(43%),其中以周期性麻痹为首发症状的甲亢10例…     

低钾型周期性麻痹30例临床分析

收集我院 1 996年以来住院治疗低钾型周期性麻痹患者 3 0例 ,全部病例均有不同程度的肌无力表现 ,现分析如下。1　临床资料1 .1　一般资料　 3 0例中 ,男 2 8例 ,女 2例 ,年龄1 8～ 48岁 ,平均 3 3岁。首次发病 1 8例 ,2次以上复发者 1 2例 ,复发后有 1次 2天内自然缓解 4例。病程最短 6h,最长 1 0年。本次发作持续时间 1 2 h至 5天 ,平均 2 .5天。1 .2　诱发因素　疲劳 9例 ,饱餐 4例 ,上感 1例 ,腹泻 1例 ,无明原因 1 5例。继发于甲亢者 7例 ,占2 3 % ;其余为原发性 ,占 76.7% ;2 1例为晨起时渐感乏力 ,9例诱因不明。1 .3　临床表现　全部…     

急诊诊治低钾型周期性麻痹79例临床分析

周期性麻痹是急诊内科的常见急症.现将我科2000年1月～2007年12月急诊收治的79例低钾型周期性麻痹报告如下. 1 临床资料     

基因敲入小鼠甲亢性低钾型周期性麻痹模型的评价

目的用基因敲入Ca V1.1-R528H小鼠建立甲亢性低钾型周期性麻痹模型并对其进行评价。方法8周龄基因敲入Ca V1.1-R528H雄性小鼠及8周龄野生型C57BL/6J雄性小鼠各36只,采用三因素两水平2×2×2析因设计方法按体重随机原则(三因素分别为突变、甲状腺素及胰岛素因素,两水平为有或无)分为8组。其中有甲状腺素处理组的小鼠制备高甲状腺素毒症,按350μg/kg体重连续腹腔注射左旋甲状腺素钠12 d,末次给药后有胰岛素处理组按0.8 U/kg体重给予腹腔注射短效胰岛素,分别检测并记录各组小鼠注射前(0 min)及注射后(30、60 min)的血钾。结果 (1)制备高甲状腺素毒症的小鼠出现烦躁不安、易激怒及毛色枯燥现象,相比对照组,饮食及饮水量明显增多,而体重增加缓慢。甲状腺功能检测显示T3、T4明显高于相应对照组,TSH明显低于相应对照组,且差异均有显著性(P0.05)。(2)单独给予甲状腺素或胰岛素处理,突变组与野生组血钾同时间点比较并没有统计学差异,而在高甲状腺素毒症下给予胰岛素处理后,突变组与野生组同时间点(30、60 min)比较突变组血钾显著低于野生组(P0.05)。(3)主效应及交互作用:单独突变因素或甲状腺素因素对血钾并没有作用,仅有胰岛素对降低血钾有作用(P0.05);甲状腺素因素和突变因素之间以及胰岛素因素和突变因素之间均有交互作用(P0.05);甲状腺素因素和胰岛素因素之间没有交互作用。结论 (1)高甲状腺素毒症制备成功。(2)利用基因敲入Ca V1.1-R528H小鼠成功的建立了甲亢性低钾型周期性麻痹模型。     

Adiponectin 基因剔除LacZ基因敲入小鼠模型的建立

adiponectin是脂肪细胞特异分泌的一种活性蛋白质,具有增加胰岛素敏感性、抗炎及抗动脉硬化等活性.建立adiponectin基因剔除β-半乳糖苷酶基因(LacZ)敲入小鼠模型,可为整体动物水平研究adiponectin基因功能及其表达调控机制等提供理想工具.根据生物信息学方法获得adiponectin基因组序列,设计基因剔除及敲入策略,在adiponectin基因第2和第3号外显子剔除的同时,在其ATG和信号肽序列后顺接LacZ基因完整编码序列,构建完成了Adipo-LacZ-XpPNT基因剔除质粒.通过电穿孔将打靶质粒转入ES细胞,以G418和ganciclovir进行药物筛选,获得药物抗性的ES细胞克隆,PCR和DNA印迹鉴定出正确同源重组克隆.将同源重组的ES细胞克隆注入小鼠囊胚得到嵌合体小鼠,嵌合体小鼠与C57BL/6J小鼠交配产生杂合子小鼠,杂合子间交配获得adiponectin基因剔除LacZ基因敲入纯合子小鼠.经RT-PCR、RNA印迹和ELISA检测证实纯合子小鼠脂肪和血清中adiponectin基因表达呈阴性.RT-PCR、RNA印迹及蛋白质印迹检测发现,LacZ基因在突变小鼠脂肪组织中有特异性表达,其表达谱与内源性adiponectin基因的表达谱一致.但在脂肪组织及外周血中未能检测到LacZ活性,且血清中LacZ蛋白亦呈阴性.由此成功建立了adiponectin基因完全灭活及LacZ基因以内源性adiponectin基因表达谱表达的小鼠模型,为进一步研究该基因功能及其表达调控创造了有利条件.     

低钾型周期性瘫痪的治疗效果分析

目的:通过探讨低钾型周期性瘫痪的临床治疗效果,旨在为临床合理治疗提供理论依据。方法:选择2013年1月-2014年1月在我院接受治疗的低钾型周期性瘫痪患者51例,,通过总结分析患者的临床资料及临床表现,通过辅助检查和及时有效补钾治疗,统计其临床疗效。结果:51例患者临床主要表现为四肢无力,近端瘫痪,双侧膝腱反应显著减退,经过口服和静脉注射补钾治疗后,患者血清中钾水平显著提高,症状缓解且愈后良好。结论:低钾型周期性瘫痪诊断较为容易,一旦发病应立即进行补钾治疗,患者临床治愈率高且疗效显著,无后遗症但治疗时有出现并发症的危险,且病情易受血钾水平影响反复发作,因此治愈后应避免诱发因素。     

长程运动诱发试验的两种方法在诊断低钾性周期性麻痹中的比较

摘要 目的：探究长程运动诱发试验（exercise test, ET）的两种方法在诊断低钾性周期性麻痹患者的价值比较。方法：选择2018年2月~2020年3月我院住院和门诊的72例低钾性周期性麻痹患者,根据ET检测的方法分为观察组和对照组,对比两组ET检测在运动后即刻、运动后的10、20、30、40、50、60 min的双侧尺神经进行复合肌肉动作电位（compound muscle action potential,cMAP）波幅和ET阳性率;以临床诊断结果为金指标,分析两组ET诊断价值。结果：两组的ET检测的阳性发生率对比无显著性差异（P>0.05）。两组波幅降低百分比在运动后即刻以及运动后的10、20、30、40、50、60 min对比无差异(P>0.05),在20 min后观察组波幅降低百分比趋势稍比对照组慢。临床诊断结果阳性68例,阳性率为94.44 %。观察组ET检测的特异性为50.0 %,灵敏度为88.23 %,对照组ET检测的特异性为25.0 %,灵敏度为80.88 %,观察组的特异性和灵敏度均优于对照组。结论：长程运动诱发试验是低钾型周期性麻痹诊断中重要的辅助诊断方法之一,且运动持续50 s,休息10 s,只做1个循环的方法,简单、快捷,可供临床诊断时优先选择。     

腓骨肌萎缩症2型(CMT2)小鼠模型的研究进展

腓骨肌萎缩症(Charcot-Marie-Tooth disease, CMT)是人类最常见的遗传性运动和感觉神经疾病之一, 全球群体发病率约为1/2500。CMT主要分为脱髓鞘型(包括CMT1, CMT3, CMT4和CMTX1)和轴索型(CMT2)。迄今为止, 先后已有17个CMT2的致病基因被定位和克隆, 然而对这些基因的致病机制所知甚少。建立CMT2小鼠模型是从动物水平研究突变基因致病机制的有效手段。目前已成功构建了近10种CMT2的转基因小鼠、基因敲除小鼠或基因敲入小鼠模型, 其中尤以带有人源致病基因的转基因小鼠模型为多。文章简要介绍了CMT2小鼠模型构建策略, 着重阐述了CMT2小鼠模型的研究进展, 并对个别小鼠模型进行了剖析。     

一中国正常血钾周期性麻痹家系中的SCN4A基因的T704M突变

家族性周期性麻痹(periodic paralysis,PP)是以反复发作骨骼肌迟缓性瘫痪为特征的一组疾病。我们对一个来自湖北省的正常血钾周期性麻痹家系进行致病基因突变检测。应用微卫星标记对该家系进行连锁分析,证实致病基因可能同SCN4A连锁。对SCN4A基因全部外显子测序,发现患者在一个致病突变热点存在碱基替换C2188T。该突变导致编码氨基酸改变Thr704Met,经单链构象多态性分析证明该突变只存在于该家系患者,不存在于家系中健康人和100名无亲缘关系对照中,Thr704Met是该家系的致病突变。     

基因前定点敲入FLAG标签表达的FLAG-SND1蛋白参与胞内应激颗粒的形成

CRISPR/Cas9 (clustered regularly interspaced short palindromic repeats-Cas9 nuclease) 基因编辑技术是近年来新兴的一种可以实现基因特异性敲除和敲入的技术。本文利用CRISPR/Cas9基因编辑系统,将3×FLAG标签定点敲入HeLa细胞SND1基因前方,使细胞内源性表达的SND1蛋白带有3×FLAG标签,并观察SND1与应激颗粒及加工体的定位情况。设计针对SND1基因起始密码子ATG附近的sgRNA,以px459为表达载体,构建出重组真核表达质粒。设计含有3×FLAG及待插入位置上下游150 bp同源臂的序列,经公司合成获得重组质粒。将2个质粒共同转染HeLa细胞,使用嘌呤霉素筛选阳性细胞,挑取单克隆后培养。Western 印迹表明,细胞表达3×FLAG-SND1融合蛋白质。提取细胞基因组DNA进行测序。测序无误获得稳定株后,用流式细胞术检测细胞周期和凋亡,发现与WT细胞相比无显著性差异。同时,使用0.5 mmol/L亚砷酸钠处理,细胞发生氧化应激,eIF2α蛋白磷酸化增加,胞浆中出现应激颗粒,SND1与应激颗粒标志蛋白TIAR存在共定位现象,但不存在与加工体蛋白DCP1α的共定位。     

Gating defects of a novel Na+ channel mutant causing hypokalemic periodic paralysis

Hypokalemic periodic paralysis type 2 (hypoPP2) is an inherited skeletal muscle disorder caused by missense mutations in the SCN4A gene encoding the alpha subunit of the skeletal muscle Na+ channel (Nav1.4). All hypoPP2 mutations reported so far target an arginine residue of the voltage sensor S4 of domain II (R672/G/H/S). We identified a novel hypoPP2 mutation that neutralizes an arginine residue in DIII-S4 (R1132Q), and studied its functional consequences in HEK cells transfected with the human SCN4A cDNA. Whole-cell current recordings revealed an enhancement of both fast and slow inactivation, as well as a depolarizing shift of the activation curve. The unitary Na+ conductance remained normal in R1132Q and in R672S mutants, and cannot therefore account for the reduction of Na+ current presumed in hypoPP2. Altogether, our results provide a clear evidence for the role of R1132 in channel activation and inactivation, and confirm loss of function effects of hypoPP2 mutations leading to muscle hypoexcitability.     

A knockout-first model of H3f3a gene targeting leads to developmental lethality

Histone variant H3.3 is encoded by two genes, H3f3a and H3f3b, which can be expressed differentially depending on tissue type. Previous work in our lab has shown that knockout of H3f3b causes some neonatal lethality and infertility in mice, and chromosomal defects in mouse embryonic fibroblasts (MEFs). Studies of H3f3a and H3f3b null mice by others have produced generally similar phenotypes to what we found in our H3f3b nulls, but the relative impacts of the loss of either H3f3a or H3f3b have varied depending on the approach and genetic background. Here we used a knockout-first approach to target the H3f3a gene for inactivation in C57BL6 mice. Homozygous H3f3a targeting produced a lethal phenotype at or before birth. E13.5 null embryos had some potential morphological differences from WT littermates including smaller size and reduced head size. An E18.5 null embryo was smaller than its control littermates with several potential defects including small head and brain size as well as small lungs, which would be consistent with a late gestation lethal phenotype. Despite a reduction in H3.3 and total H3 protein levels, the only histone H3 post-translational modification in the small panel assessed that was significantly altered was the unique H3.3 mark phospho-Serine31, which was consistently increased in null neurospheres. H3f3a null neurospheres also exhibited consistent gene expression changes including in protocadherins. Overall, our findings are consistent with the model that there are differential, cell-type-specific contributions of H3f3a and H3f3b to H3.3 functions in epigenetic and developmental processes.     

Activation of γ-aminobutyric acid insensitive chloride channels in mouse brain synaptic vesicles by avermectin B1a

The interaction of avermectin B_1a (AVMB_1a) with mouse brain chloride channels was characterized using a radiochloride efflux assay. The loss of intravesicular chloride from synaptoneurosomes preloaded with ³⁶Cl involved an initial rapid phase followed by a slower phase that approached equilibrium within 10 min. AVMB_1a stimulated a 30% loss of intravesicular chloride within the first 2 s of exposure; however, AVMB_1a had no effect on the rate of the slower phase of chloride loss. Experiments with lysed synaptoneurosomes showed that both chloride loading and basal and AVMB_1a-stimulated chloride release required the presence of intact vesicles. The efflux of ³⁶Cl from mouse brain synaptosomes and the stimulation of efflux by AVMB_1a were qualitatively similar to the results obtained with synaptoneurosomes but involved much lower overall levels of chloride loading and release. AVMB_1a produced halfmaximal stimulation of chloride efflux from synaptoneurosomes at a concentration of 2.1 ± 0.3 μM and a 35.4 ± 1.4% maximal loss of intravesicular chloride at saturating concentrations. γ-Aminobutyric acid (GABA), bicuculline, or the chloride channel blockers picrotoxinin, t-butylbicyclophosphorothionate (TBPS) 4,4′-diisothiocyanatostilbene-2,2′-disulfonic acid (DIDS), and anthracene 9-carboxylic acid (9-CA) had little or no effect on the loss of chloride from synaptoneurosomes either in the presence or the absence of AVMB_1a. However, the chlorinated cycloalkane insecticides dieldrin and lindane were equally effective as inhibitors of GABA-dependent chloride uptake and AVMB_1a-stimulated chloride efflux. These data demonstrate that AVMB_1a-stimulated chloride efflux from mouse brain synaptic vesicles results from the activation of GABA-insensitive chloride channels and that this action is distinct from their previously documented effects on GABA-gated chloride channels in mouse brain preparations. Our findings imply that both GABA-gated and GABA-insensitive chloride channels may be toxicologically significant targets for the action of avermectins.     

The gene for the alpha 1 subunit of the skeletal muscle dihydropyridine-sensitive calcium channel (Cchl1a3) maps to mouse chromosome 1.

Cchl1a3 encodes the dihydropyridine-sensitive calcium channel alpha 1 subunit isoform predominantly expressed in skeletal muscle. mdg (muscular dysgenesis) has previously been implicated as a mutant allele of this gene. Hybridization of a rat brain cDNA probe for Cchl1a3 to Southern blots of DNAs from a panel of Chinese hamster x mouse somatic cell hybrids suggested that this gene maps to mouse Chromosome 1. Analysis of the progeny of an inbred strain cross-positioned Cchl1a3 1.3 cM proximal to the Pep-3 locus on Chr 1.     

Hrd1 induces cardiomyocyte apoptosis via regulating the degradation of IGF-1R by sema3a

Objective

To explore the underlying mechanisms of Hrd1/sema3a/IGF-1R on cardiomyocyte apoptosis.

A regulatory gene network related to the porcine umami taste receptor (TAS1R1/TAS1R3)

Taste perception plays an important role in the mediation of food choices in mammals. The first porcine taste receptor genes identified, sequenced and characterized, TAS1R1 and TAS1R3, were related to the dimeric receptor for umami taste. However, little is known about their regulatory network. The objective of this study was to unfold the genetic network involved in porcine umami taste perception. We performed a meta‐analysis of 20 gene expression studies spanning 480 porcine microarray chips and screened 328 taste‐related genes by selective mining steps among the available 12 320 genes. A porcine umami taste‐specific regulatory network was constructed based on the normalized coexpression data of the 328 genes across 27 tissues. From the network, we revealed the ‘taste module’ and identified a coexpression cluster for the umami taste according to the first connector with the TAS1R1/TAS1R3 genes. Our findings identify several taste‐related regulatory genes and extend previous genetic background of porcine umami taste.     

人星状病毒非结构蛋白基因nsP1a/1真核表达载体构建及其

目的 将人星状病毒非结构蛋白nsP1 a./1基因连接到真核表达载体上,转染人胚肾上皮细胞48 h后检测其表达.方法 设计特异性引物PCR扩增人星状病毒非结构蛋白nsP1 a/1片段,分别插入真核表达载体pcDNA3.1(+)和pEGFP-N2载体,构建重组表达质粒pcDNA3.1(+)-nsP1a/1-His和pEGFP-N2-nsP1a/1.在转染试剂PEI的介导下将重组表达质粒分别转染293T细胞,转染48 h后分别在荧光显微镜下观察EGFP的表达以及通过Western blot检测nsP1a/1基因的表达.结果 重组表达质粒pcDNA3.1(+)-nsP1a/1-His和pEGFP-N2-nsP1a/1构建成功;转染pEGFP-N2-nsP1a/1后48 h能够在荧光显微镜蓝色激发光下观察到较强的黄绿色荧光;转染pcDNA3.1(+)-nsP1a/1-His后48 h收集细胞进行Western blot检测,能够检测到nsP1a/1-His融合报告基因的表达.结论 成功构建了人星状病毒非结构蛋白nsP1a/1基因真核表达质粒,并在人胚肾上皮细胞293T细胞获得表达,为进一步深入研究nsP1a/1在人星状病毒抵御宿主细胞抗病毒天然免疫中是否发挥作用奠定了基础.     

Biochemical fractionation reveals association of DNA methyltransferase (Dnmt) 3b with Dnmt1 and that of Dnmt 3a with a histone H3 methyltransferase and Hdac1

De novo DNA methyltransferases, Dnmt3a and 3b, were purified by fractionation of S-100 extract from mouse lymphosarcoma cells through several chromatographic matrices followed by glycerol density gradient centrifugation. Dnmt3a was separated from Dnmt3b and Dnmt1 in the first column, Q-Sepharose whereas Dnmt3b co-purified with Dnmt1 after further fractionation through Mono-S and Mono-Q columns and glycerol density gradient centrifugation. Following purification, the majority of de novo DNA methyltransfearse activity was associated with Dnmt3b/Dnmt1 fractions. By contrast, the fractions containing Dnmt3a alone exhibited markedly reduced activity, which correlated with diminished expression of this isoform in these cells. Histone deacetylase 1(Hdac1) cofractionated with Dnmt3a throughout purification whereas Hdac1 was separated from Dnmt3b/Dnmt1 following chromatography on Mono-Q column. Dnmt3a purified through glycerol gradient centrifugation was also associated with a histone H3 methyltransferase (HMTase) activity whereas purified Dnmt3b/Dnmt1 was devoid of any HMTase activity. The activity of this HMTase was abolished when lysine 9 of N-terminal histone H3 peptide was replaced by leucine whereas mutation of lysine 4 to leucine inhibited this activity only partially. This is the first report on the identification of a few key co-repressors associated with endogenous Dnmt3a and of a complex containing Dnmt3b and a minor form of Dnmt1 following extensive biochemical fractionation.     

Characterization of [(3)H]Quisqualate binding to recombinant rat metabotropic glutamate 1a and 5a receptors and to rat and human brain sections

We have investigated the binding properties of [(3)H]quisqualate to rat metabotropic glutamate (mGlu) 1a and 5a receptors and to rat and human brain sections. Saturation isotherms gave K:(D) values of 27 +/- 4 and 81 +/- 22 nM: for mGlu1a and mGlu5a receptors, respectively. Several compounds inhibited the binding to mGlu1a and mGlu5a receptors concentration-dependently. (S:)-4-Carboxyphenylglycine, (S:)-4-carboxy-3-hydroxyphenylglycine, and (R,S)-1-aminoindan-1,5-dicarboxylic acid, which completely inhibited [(3)H]quisqualate binding to the mGlu5a receptor, were inactive in a functional assay using this receptor. The distribution and abundance of binding sites in rat and human brain sections were studied by quantitative receptor radioautography and image analysis. Using 10 nM: [(3)H]quisqualate, a high density of binding was detected in various brain regions with the following rank order of increasing levels: medulla, thalamus, olfactory bulb, cerebral cortex, spinal cord dorsal horn, olfactory tubercle, dentate gyrus molecular layer, CA1-3 oriens layer of hippocampus, striatum, and cerebellar molecular layer. The ionotropic component of this binding could be inhibited by 30 microM: kainate, revealing the distribution of mGlu1+5 receptors. The latter were almost completely inhibited by the group I agonist (S:)-3,5-dihydroxyphenylglycine. The binding profile correlated well with the cellular sites of synthesis and regional expression of the respective group I receptor proteins revealed by in situ hybridization histochemistry and immunohistochemistry, respectively.     

一个抑制AP-1活性的人类新基因AC3-33的克隆和初步功能研究

Activator protein-1(AP-1)是重要的转录因子, 其活性失调与肿瘤等多种疾病直接相关。本文运用“高通量高内涵细胞筛选技术(high throughput-high content cell-based screening technology)”对650个以未知功能基因为主的人类基因进行AP-1双荧光素酶报告基因筛选(Dual-Luciferase reporter gene screening), 获得了一个可抑制佛波酯(PMA)加离子霉素(Inonmycin)诱导的AP-1活性的人类新基因AC3-33(GenBank中该基因名为C3orf33, No. FLJ31139)。生物信息学分析该基因序列全长1 931 bp, 由6 个外显子和5 个内含子组成, 定位于3q25.31, 从271~1026 有一个编码251 个氨基酸的可读框, 编码一个约29 kDa 的蛋白, 在肾上腺和宫颈等多种组织都有表达。AC3-33 与其他人类已知蛋白质没有明显的同源性, 亚细胞定位于细胞质中, 许多氨基酸序列高度保守。初步实验结果显示AC3-33是一个有重要功能的人类新基因。