利用黑斑双鳍电鳐构建实验性自身免疫性重症肌无力小鼠模型

目的建立符合国际化的临床前实验标准的实验性自身免疫性重症肌无力(experimental autoimmune myasthenia gravis, EAMG)动物模型。方法参照文献报道的方法并改进后,从电鳐电器官提取乙酰胆碱受体(acetylcholine receptor,AchR)蛋白纯品,并采用SDS凝胶电泳蛋白定性鉴定及BCA法蛋白定量;用纯化的蛋白主动免疫C57BL/6小鼠,共免疫3次(分别于第1天、第30天、第60天),进行EAMG小鼠临床评分、体重、血清AchR抗体含量、新斯的明试验、肌电图等综合评价。结果 EAMG模型组与佐剂组比较,自第三周开始发病,平均临床评分显著上升(P<0.01);发病小鼠体重显著减轻(P<0.01);新斯的明试验阳性;血清AchR抗体含量明显增加(P<0.01);肌电图重复电刺激实验阳性。结论从黑斑双鳍电鳐的电器官提取、纯化AchR蛋白成功诱导C57BL/6 EAMG小鼠模型,为进一步研究重症肌无力创造了良好条件。     

重症肌无力的分类及遗传学基础

重症肌无力是一种罕见的自身免疫性疾病,其特征是机体自身产生了针对神经肌肉接头处突触后膜蛋白质的抗体,造成神经冲动的传递功能障碍从而导致肌肉无力、易疲劳的现象。根据血清中产生的抗体和临床表型,重症肌无力患者可分为不同的亚类,其发病机制受遗传和环境等多种因素的综合影响。本综述系统地总结了重症肌无力的亚组分类及最新的相关遗传学研究基础,重点论述了该病的易感基因、家族性重症肌无力及重症肌无力的表观遗传学研究,从而为疾病的预防、治疗以及相关领域研究提供参考。     

重症肌无力患者抗乙酰胆碱受体抗体的测定及意义

用ELISA法对56例重症肌无力(MG)患者治疗前后的血清乙酰胆碱受体(AchR)抗体进行了检测。检测结果为MG患者治疗前后的血清AchR抗体阳性率46.4%。而且发病年龄越大,患者体内AchR抗体阳性率越高。患者患病时间越长体内AchR抗体含量降低。伴发胸腺瘤的患者AchR抗体阳性率明显高于胸腺正常者,全身型MG患者AchR抗体检测阳性率高于眼肌型患者。     

碘标神经毒素—乙酰胆硷受体复合物对重症肌无力研究的初步应用

眼镜蛇神经毒素化学性质稳定,易于保存,用~(131)I或~(125)I标记,方法简便,比活性高,能专一性地与菸硷型乙酰胆硷受体结合,常作为一种分子探测剂,用来研究蛇毒的毒理作用(杨钦照1977)、测定菸硷型乙酰胆硷受体的浓度,于临床还可以检测重症肌无力患者抗乙酰胆硷受体抗体(Lindstrom,1976;Lefvert 1978)。对研究神经肌接头的生理功能,阐明重症肌无力的发病机理、辅助诊断和观察疗效均有实际意义。     

肌萎缩侧索硬化症病程中骨骼肌内铁沉积及其调节

目的 研究肌萎缩侧索硬化症(amyotrophic lateral sclerosis, ALS)小鼠模型骨骼肌中铁沉积及相关转运蛋白的表达变化,探讨铁调节蛋白1(IRP1)的可能调节作用。方法 选取携带人源SOD1G93A突变基因小鼠(ALS鼠)和同窝野生型小鼠(WT鼠)为动物模型,分别收集发病前期(70d)、发病早期(95d)、发病期(108d)、发病后期(122d)模型鼠腓肠肌,以普鲁士蓝染色法检测骨骼肌内铁沉积;Western blot技术检测铁转入蛋白二价金属离子转运蛋白1(DMT1)、铁转出蛋白ferropotin1(FPN1)和IRP1的表达变化。结果 在ALS鼠发病期及发病后期腓肠肌内检测到铁沉积。与同窝WT小鼠相比,随病程进展ALS鼠腓肠肌中DMT1表达增高;FPN1水平除70d有增高趋势外,其他时间点ALS组均较WT组呈现降低趋势,但差异无统计学意义。IRP1在70d和95d表达显著降低,随病程进展较WT组呈现上升趋势。结论 ALS病程中腓肠肌内铁转运调节失衡可导致腓肠肌内铁沉积。IRP1部分参与铁转运蛋白的表达调节。     

同种异体淋巴细胞致狼疮肾炎小鼠模型的研究

目的　制备狼疮肾炎小鼠模型。方法　采用昆明小鼠同种异体脾淋巴细胞经Lectin刺激后输入小鼠腹腔皮下的方法。结果　成功地制备了系膜增生型狼疮肾炎小鼠模型 ,通过光镜、免疫荧光、电镜观察其病理形态、并检测了血清抗ds -DNA抗体、补体以及尿蛋白 ,证实了该模型的可靠性。结论　制备的系膜增生型狼疮肾炎小鼠模型有实用价值     

鼠源戊型肝炎病毒IgG抗体定量检测方法的建立

目的制备鼠源戊型肝炎病毒(Hepatitis E Virus,HEV)抗体定量参考品,建立小鼠HEV IgG抗体定量检测方法,并对其进行验证及初步应用。方法制备鼠源抗-HEV IgG参考血清MS1,以世界卫生组织人源抗-HEV Ig标准品(NIBSC code:95/584)对其进行标定并检测其稳定性;以标定的参考品为标准,建立小鼠HEV IgG抗体定量检测方法,对线性、范围、重复性、准确度等进行验证,并对戊肝疫苗免疫后小鼠血清进行HEV IgG抗体定量检测。结果制备的MS1血清含量为30.9U/m L(95%CI:±1.1),CV为4.8%;加速稳定性试验和冻融稳定性试验中,MS1含量CV均15%。建立的小鼠抗-HEV IgG抗体定量检测方法在0.01~0.15 U/m L范围内具有良好的线性(r0.99);灵敏度为0.007 U/m L;对高、中、低3份不同含量抗-HEV阳性小鼠血清重复检测3次,CV均10%;加样回收率为83.8%~107.7%。戊肝疫苗免疫1 w,3 w,5 w时,小鼠血清HEV IgG抗体均值分别为0.3 U/m L、39.4 U/m L、345.4 U/m L。戊肝疫苗初次免疫小鼠1 w后抗体阳转率为100%,但抗体均处于较低水平;血清抗体水平随着免疫针次的增加而升高(P0.05)。结论制备的鼠源HEV IgG抗体定量参考稳定性良好的,建立的小鼠HEV IgG抗体定量检测方法,具有良好的灵敏度、重复性及准确度,可用于小鼠实验中戊肝疫苗免疫原性的评价。     

血清胆红素与尿酸水平对重症肌无力的临床意义

目的：探讨血清胆红素以及尿酸的水平对重症肌无力患者的临床价值。方法：选取我院确诊的重症肌无力患者作为实验组, 另选择同期体检的健康志愿者作为对照组。检测并比较两组血清直接胆红素(DBIL)、间接胆红素(IBIL)、总胆红素(TBIL)、尿酸 (UA)及肌酐(Cr)等指标水平。结果：实验组血清DBIL、IBIL、TBIL、UA 水平均显著低于对照组,差异有统计学意义(P＜0.05),但实 验组不同类型的MG 患者血清DBIL、IBIL、TBIL、UA水平比较差异均无统计学意义(P>0.05)。同组男性DBIL、IBIL、TBIL、UA值 均明显高于女性,差异具有统计学意义(P<0.05);两组间相同性别比较,实验组DBIL、IBIL、TBIL、UA 均低于对照组,差异有统计 学意义(P＜0.05)。结论：检测血清BIL 和UA水平对诊断重症肌无力具有一定的参考价值。     

H7N9禽流感病毒小鼠感染动物模型的建立

目的建立H7N9禽流感病毒小鼠感染模型。方法 1×108,1×107或1×106TCID50H7N9禽流感病毒原液(A/Anhui/1/2013)滴鼻感染BALB/c小鼠。主要观测指标:临床症状、死亡率、病理变化、病毒载量和血清抗体检测。结果被感染的小鼠表现为竖毛、弓背、体重下降;病理表现为间质性肺炎,感染后第2天开始在呼吸道脱落细胞中检测到病毒;免疫组化或病毒分离方法在肺、肾、脑、肠、脾等组织检测到病毒;感染后14 d在小鼠血清中血凝抑制试验特异性抗体效价达到160;淋巴细胞减少,中性粒细胞增多。结论 H7N9感染BALB/c小鼠模型与人类禽流感感染疾病的基本特征相似,为研究该病的发病机制及药物疫苗的研发提供了工作基础。     

糖尿病下肢溃疡小鼠模型的建立与评价

目的建立和评价糖尿病下肢溃疡小鼠模型,揭示糖尿病下肢溃疡小鼠手术肢血流和病理生理的改变,初探其发病机制,为研究糖尿病外周血管病变提供基础和参考。方法小鼠分为下肢缺血组、糖尿病组和糖尿病下肢溃疡组。糖尿病下肢溃疡和糖尿病组腹腔注射链脲佐菌素(STZ)建立1型糖尿病模型。糖尿病下肢溃疡和下肢缺血组,采用高位结扎股动脉、股静脉并断离股动脉的方法建立下肢缺血模型;糖尿病组仅做假手术处理。术后第0、3、7、14、21天,用激光多普勒监测血流变化,观察肢体缺血坏死。第21天后HE切片观察组织形态变化,分析血小板-内皮细胞粘附分子-1(PECAM-1/CD31)及抗平滑肌抗体(SMA)表达。结果缺血术后,与下肢缺血组小鼠比较,糖尿病下肢溃疡组体重显著下降,肢体坏死情况更严重。术后,糖尿病下肢溃疡组和下肢缺血组小鼠手术肢血流灌注下降明显;术后第3、7、14天,糖尿病下肢溃疡组和下肢缺血组血流灌注逐渐恢复;第21天,下肢缺血组接近正常水平,而糖尿病下肢溃疡组略有下降。糖尿病组无肢体坏死情况,血流灌注无明显变化。糖尿病下肢溃疡组和下肢缺血组小鼠手术肢腓肠肌组织有肌肉结构破坏和炎症浸润,CD31表达明显增加;糖尿病下肢溃疡组和糖尿病组SMA有显著表达,而下肢缺血组表达不明显。结论成功建立了糖尿病下肢溃疡小鼠模型,与下肢缺血小鼠模型对比,该模型有明显的肢体坏死症状和血流灌注恢复障碍。该模型可用于研究糖尿病血管病变发病机制的研究以及治疗药物的筛选。     

Congenital Myasthenic Syndrome in the Dog Breed Gammel Dansk Hønsehund: Clinical,Electrophysiological, Pharmacological and Immunological Comparison with Acquired Myasthenia gravis

The effect of anticholinesterase drugs on the clinical and electrophysiological features in a canine congenital myasthenic syndrome is compared with findings in acquired myasthenia gravis in dogs. Anticholinesterase treatment had no effect on muscle weakness or electrophysiological parameters in the congenital myasthenic syndrome in contrast to its effect on clinical signs and electrophysiological parameters in acquired myasthenia gravis. The lack of effect of anticholinesterase in congenital myasthenia suggests a presynaptic defect as the aetiological factor. No antibodies to acetylcholine receptors were found in the Danish dog breed Gammel Dansk Hønsehund with the myasthenic syndrome. This classifies the disease in the group of canine and human congenital myasthenic diseases.     

Interaction of myasthenic serum globulin with the acetylcholine receptor.

A serum factor from patients with myasthenia gravis which inhibited the binding of 125I-labeled alpha-bungarotoxin to acetylcholine receptor extracted with Triton X-100 from rat muscle has been studied in detail. The inhibitory activity was localized to the IgG fraction based upon the fractionations by sodium sulfate precipitation and DEAE chromatography as well as reaction with anti-IgG globulin. The myasthenic globulin inhibited toxin binding to receptors extracted from degenerated muscle but did not inhibit toxin binding to normal junctional receptors. At saturation levels of myasthenic globulin, the number of denervated acetylcholine receptors available for toxin binding was reduced approx. 50 percent. The myastehnic globulin was found to bind to denervated acetylcholine receptors but not to normal acetylcholine receptors by a radioimmunoassay technique in which myasthenic globulin incubated with 125I-labeled alpha bungarotoxin-receptor complexes was precipitated by anti-IgG serum. The globulin binding was saturable over the same range as inhibition of toxin binding. The data suggest that the myasthenic IgC binds to a site on the receptor complex juxtaposed to the acetylcholine receptor site. The myasthenic globulin appears to be a useful probe for investigation differences between acetylcholine receptors extracted from normal and denervated muscle and for investigating the pathogenesis of myasthenia gravis.     

Degradation of acetylcholine receptor in diaphragms of rats with experimental autoimmune myasthenia gravis.

The degradation of acetylcholine receptor observed in denervated and innervated normal rat diaphragms in organ culture is stimulated by exogenous antireceptor serum. In this paper we demonstrate that diaphragms from rats with experimental autoimmune myasthenia gravis contain reduced amounts of acetylcholine receptor. Acetylcholine receptor from myasthenic, but not from normal, rats has antibody bound to it and is degraded at an accelerated rate. We conclude that in the chronic phase of experimental autoimmune myasthenia gravis increased acetylcholine receptor degradation can be accounted for by a mechanism involving antigenic modulation, and that such a process can contribute to the clinical symptoms of impaired neuromuscular transmission.     

Antibodies to muscarinic acetylcholine receptors in myasthenia gravis

IgG obtained from patients with myasthenia gravis block the specific binding of the muscarinic antagonists (³H)-N-methyl-4-piperidyl benzilate (4NMPB) and (³H)-Quinuclidinyl benzilate to rat brain muscarinic acetylcholine receptors. IgG obtained from healthy controls have a much smaller effect. The inhibitory effect of the myasthenic IgG increases linearly with immunoglobulin concentration and has no effect on the affinity of the muscarinic receptors towards (³H)-4NMPB (K_D = 0.7 ± 0.1 nM). This implies that the inhibition is probably due to the blocking of some of the muscarinic receptors by the myasthenic IgG, and not due to alteration in affinity of all the receptors. it remains to be established whether the presence of antimuscarinic receptor activity in the serum of myasthenic patients is of importance in the pathophysiology and diagnosis of myasthenia gravis.     

Adverse effects of myasthenia gravis on rat phrenic diaphragm contractile performance.

Myasthenia gravis has variable effects on the respiratory system, ranging from no abnormalities to life-threatening respiratory failure. Studies characterized diaphragm muscle contractile performance in rat autoimmune myasthenia gravis. Rats received monoclonal antibody that recognizes acetylcholine receptor determinants (or inactive antibody); 3 days later, phrenic nerve and diaphragm were studied in vitro. Myasthenic rats segregated into two groups, those with normal vs. impaired limb muscle function when tested in intact animals ("mild" and "severe" myasthenic). Baseline diaphragm twitch force was reduced for both severe (P < 0.01) and mild (P < 0.05) myasthenic compared with control animals (twitch force: normal 1,352 +/- 140, mild myasthenic 672 +/- 99, severe myasthenic 687 +/- 74 g/cm2). However, only severe myasthenic diaphragm had impaired diaphragm endurance, based on significantly (P < 0.05) accelerated rate of peak force decline during the initial period of stimulation (0.02 + 0.02, 0.03 +/- 0.01, and 0.09 +/- 0.01%/pulse for normal, mild myasthenic, and severe myasthenic, respectively, during continuous stimulation) and intratrain fatigue (up to 30.5 +/- 7.4% intratrain force drop in severe myasthenic vs. none in normal and mild myasthenic, P < 0.01). Furthermore, compared with continuous stimulation, intermittent stimulation had a protective effect on force of severe myasthenic diaphragm (force after 2,000 pulses was 31.4 +/- 2.0% of initial during intermittent stimulation vs. 13.0 +/- 2.1% of initial during continuous stimulation, P < 0.01) but not on normal diaphragm. These data indicate that baseline force and fatigue may be affected to different extents by varying severity of myasthenia gravis and furthermore provide a mechanism by which alterations in breathing pattern may worsen respiratory muscle function in neuromuscular diseases.     

Myasthenia Gravis: Anesthetic and Surgical Management of the Patient Undergoing Thymectomy

Experience in the anesthetic and surgical management of 25 patients with myasthenia gravis is recorded. These are subdivided into two groups: those operated on during the period 1950-1958 and those operated on during the period 1959-1964. The purpose of this paper is to indicate improvement in mortality and morbidity due to three major advances: (1) use of the decamethonium diagnostic test in a myasthenia gravis clinic; (2) improvements in assessment and management of respiratory insufficiency; and (3) avoidance of anticholinesterase treatment in the immediate and early postoperative recovery period.Fourteen patients with myasthenia gravis, including five with thymoma and two who were refractory to medication, were in the second (1959-1964) group. There were no deaths and no myasthenic or cholinergic crises. Three prophylactic tracheostomies were performed. No emergency bronchoscopies or tracheostomies were required.     

Amelioration of experimental autoimmune myasthenia gravis in rats by neonatal FcR blockade

The neonatal FcR (FcRn) plays a critical role in IgG homeostasis by protecting it from a lysosomal degradation pathway. It has been shown that IgG has an abnormally short half-life in FcRn-deficient mice and that FcRn blockade significantly increases the catabolism of serum IgG in mice. Therefore, reduction of serum IgG half-life may have therapeutic benefits in Ab-mediated autoimmune diseases. We have studied the therapeutic effects of an anti-rat FcRn mAb, 1G3, in two rat models of myasthenia gravis, a prototypical Ab-mediated autoimmune disease. Passive experimental autoimmune myasthenia gravis was induced by administration of an anti-acetylcholine receptor (AChR) mAb, and it was shown that treatment with 1G3 resulted in dose-dependent amelioration of the disease symptoms. In addition, the concentration of pathogenic Ab in the serum was reduced significantly. The effect of 1G3 was also studied in an active model of experimental autoimmune myasthenia gravis in which rats were immunized with AChR. Treatment with 1G3 significantly reduced the severity of the disease symptoms as well as the levels of total IgG and anti-AChR IgG relative to untreated animals. These data suggest that FcRn blockade may be an effective way to treat Ab-mediated autoimmune diseases.     

Myasthenia gravis associated with penicillamine treatment for rheumatoid arthritis.

Four patients with rheumatoid arthritis (R.A.) developed myasthenia gravis after taking penicillamine. In one patient withdrawal of the drug was followed by spontaneous remission of the myasthenia, and in two the dose of anticholinesterase was subsequently reduced. In the fourth patient continuing penicillamine treatment was associated with increasingly severe myasthenic features, but on withdrawal of the drug these resolved. As myasthenia gravis rarely complicates R.A. its onset in these patients shortly after the start of penicillamine treatment suggested that penicillamine may have precipitated this condition.     

The effects of myasthenic IgG on miniature end-plate currents in mouse diaphragm

In diaphragms from mice injected with purified IgG from a patient with myasthenia gravis, miniature end-plate currents (m.e.p.c.s) were reduced in size by about 50% and sensitivity to superperfused carbachol was also reduced. The ‘myasthenic’ m.e.p.c.s closely resembled m.e.p.c.s made small by α-bungarotoxin (α-BuTX) or (+)-tubocurarine with regard to alteration of height by poisoning of acetylcholinesterase and sensitivity to further receptor blockade. However, the time course of decay of the ‘myasthenic’ m.e.p.c.s was closer to normal than in m.e.p.c.s reduced in size by dTC or α-BuTX. It is postulated that myasthenic IgG acts to interfere with receptor function to open ionic channels more than it blocks binding of ACh to receptor.