McCune-Albright综合征多病变部位基因诊断

目的 研究1例McCune—Albright综合征（MAS）患者不同病变组织的G蛋白仅亚单位（Gsot）基因突变情况。方法 收集1例MAS患者的外周血、病变骨组织、皮肤及胸膜组织样本，分别提取基因组DNA并对目的片段进行PCR扩增和直接测序。结果 该患者外周血和骨组织中存在Gsα基因R201C突变，而其皮肤和胸膜组织中未检出突变。结论 经基因诊断证实该例临床确诊的MAS患者的Gsα基因存在经典的R201C突变，且累及多种组织。突变发生在胚胎形成早期，临床表现可呈现多样性。     

人类GNAS1基因突变的研究进展

GNAS1通过不同的启动子和共同的2~13号外显子转录产生Gsα,NESP55,XLαs等多种基因产物,主要产物是异源三聚体的Gsα,介导激素等多种细胞外因子的细胞内信号转导。GNAS1的种系失活性突变会导致Albright遗传性骨营养不良症(AHO)。活化的体细胞突变会导致以环磷酸腺苷(cAMP)为有丝分裂信号的细胞增殖,经典的表现为McCune-Albright综合征(MAS)。A366S突变发生在男性患者可表现为假性甲状旁腺功能减退症Ⅰa型(PHPⅠa)和睾丸中毒症并存。组织特异性的激素抵抗可能是由于组织特异性的GNAS1印记缺陷所致。     

刺激性三磷酸鸟苷结合蛋白α亚单位基因与国人原发性高血压相关研究

目的探讨刺激性三磷酸鸟苷结合蛋白α亚单位(Gsα)基因限制性内切酶(FokI)多态性与国人原发性高血压及其左心室结构之间的关系.方法采用多聚酶链反应限制性片断长度多态性(PCR-RFLP)方法检测78例健康人(正常对照组)和142例原发性高血压患者(高血压组)Gsα基因FokI多态性,超声测定患者的左心室结构.结果①高血压组Gsα基因FokI等位基因频率与正常对照组比较有显著性差异(P＝0.018);②高血压组不同基因型患者间的左心室后壁厚度有显著性差异(P＝0.040).结论提示Gsα基因FokI多态性与国人原发性高血压及其左心室后壁厚度相关.Gsα基因可能是原发性高血压的遗传因素.     

RNAi选择性下调大鼠心肌细胞上Gsα蛋白的体外实验

目的:用RNA干扰技术(RNA interference, RNAi)选择性下调大鼠心肌细胞上乌苷酸结合蛋白(Gs)α亚基(Gs protein alphala subunit, Gsα)的表达,筛选出抑制Gsα蛋白效果最明显的特异短发夹RNA(short hairpin RNA, shRNA)表达质粒.方法:构建3条靶向gnas基因的特异与RNA质粒载体(shRNA1-3),以含非特异性shRNA编码序列的质粒载体为阴性对照(HK),用脂质体LipofectamineTM LTX & PLUS转染原代培养的大鼠心肌细胞,并设空白对照组,转染后通过半定量RT-PCR和Western blot法检测Gsα mRNA和蛋白的表达情况,以内参照三磷酸甘油醛脱氢酶(GAPDH)进行标化.结果:shRNA1-3均使Gsα的mRNA和蛋白质表达明显降低,差异有统计学意义(P<0.01),且shRNA3的抑制效果最显著,阴性对照质粒组与空白对照组Gsα表达差异无统计学意义.结论:利用RNAi技术成功下调了原代培养的心肌细胞中Gsα的表达,并筛选出沉默效果最明显的shRNA真核表达质粒,为心肌细胞的转染提供了可行的方法.     

老化的心血管系统中G蛋白及亚单位的表达

G结合蛋白受体调节心脏和血管收缩,老化过程中有受体反应性的改变,老化的心血管系统中β受体效应器结合减低,可能是因为G蛋白的变化,后者是因信息传导过程的改变而不是受体改变。对成龄和老龄Fisher344鼠的心脏和主动脉G蛋白及亚单位和其mRNA水平进行定量测定,主动脉的西方印迹分析显示在39kD有一个单一的Goα带、41kD区有单一Gia带,38、42、45、52kD区有4条Gsα带。增龄时Goα、Giα和42kD带的Gsα减弱,但其他Gsα型不变。心房、心室西方印迹分析示39kD区单一Goα带在心房里的量比心室、主动脉多,心房心室含有单一41kDGiα带。42、45、52kD区3条Gsα带。增龄时心房或心室Gsα、Giα、Gsα不变。主动脉的北方印迹分析显示两条Goα mRNA带(3.4和3.8kb),一条Gi2mRNA(2.0kb)。一条Gi3 mRNA(3.5kb),一条Gsα mRNA(1.8kb)。增龄时主动脉中Gα mRNA含量无明显变化。心脏mRNA北方印迹分析示Gi2mRNA两个带(3.8和5.4kb),一条Gi2α mRNA带(1.7kb),一条Gi3 mRNA(3.5kb),一条Gsα mR-NA(1.8kb)。增龄时心脏的Gi2α和Gi3α mRNA水平明显增高而Goα和Gsα水平不变。     

Alport综合征的治疗

Alport综合征(Alport syndrome,AS)是一种以进行性肾功能减退和肾小球基膜(glomerular basement membrane,GBM)结构异常伴神经性耳聋和眼病为临床特征的遗传性肾病.AS的发生与基膜主要成分Ⅳ型胶原α3～α5链编码基因COL4A3、COL4A4和COL4A5突变有关.作为引起肾衰的第二大遗传因素,AS并非罕见,但又缺乏针对性的治疗方案.     

青少年的成人起病型糖尿病2型和3型混合家系一例临床分析并文献复习

目的探究葡萄糖激酶基因(GCK)及肝细胞核因子1α基因(HNF-1α)同时突变致青少年的成人起病型糖尿病(MODY)的临床和遗传学特点。方法对北京协和医院2017年9月诊断的一例MODY患者及其家系的临床特征、实验室资料进行分析;对家系成员进行MODY相关致病基因检测。结果该家系的5名成员检测到GCK基因(NM_000162)c.686C>T(p.Thr229Met)杂合突变。其中3名成员同时检测到HNF-1α基因(NM_001306179)c.1531C>G(p.Gln511Glu)杂合突变。结论MODY混合家系GCK及HNF-1α基因突变导致同一家系出现不同的MODY类型。诊断时需考虑混合家系的可能性,以准确诊断。     

G蛋白α亚基mRNA在不同甲状腺疾病的表达

目的　观察G蛋白α亚基mRNA在不同甲状腺疾病的表达。方法　收集手术切除的甲状腺组织包括Graves病 5例、结节性甲状腺肿 7例、正常功能甲状腺腺瘤 6例和甲状腺乳头状癌 5例 ,以腺瘤周围组织作为正常甲状腺组织对照 ,观察刺激性G蛋白 (Gs)和抑制性 (Gi)α亚基的表达。结果　 (1 )GsαmRNA的表达 :甲状腺乳头状癌 (1 67± 0 2 5)较正常甲状腺组织 (1 1 0± 0 1 4 )和结节性甲状腺肿 (0 96± 0 31 )明显增高 (P <0 0 5和P <0 0 1 ) ,Graves病 (1 47± 0 1 1 )和正常功能甲状腺腺瘤 (1 36± 0 2 8)均显著高于结节性甲状腺肿 (P <0 0 5) ,但与正常甲状腺组织表达水平相似 ;(2 )Giα 2mRNA的表达 :Graves病显著低于结节性甲状腺肿 (0 68± 0 2 6比 1 1 5± 0 35 ,P <0 0 5) ;(3)Giα 1和Giα 3mRNA在不同甲状腺疾病的表达相似。结论　Gs蛋白α亚基的高表达可能在甲状腺乳头状癌的发病中起重要作用 ,不同疾病时甲状腺G蛋白α亚基具有不同的表达水平     

胃肠道间质瘤组织中PDGFRα和C-kit基因突变和蛋白表达的关系

目的:检测胃肠道间质瘤(GIST)中PDGFRα和C-kit基因突变及其蛋白表达的关系及在肿瘤形成中的作用.方法:采用单链象多态性聚合酶链式反应(PCR-SSCP),免疫组化和蛋白印迹(Western blot)方法,检测GIST 52例中PDGFRα和C-kit基因突变及蛋白表达情况.结果:GIST 52例中PDGFRα基因突变5例(9.6%),多见于梭形细胞型的胃源性GIST,C-kit基因突变28例(53.8%),多发生于小肠,并且这两种基因突变互相独立;PDGFRα蛋白表达率100%,C-kit蛋白的表达率为94.2%,突变的5例GIST PDGFRα强于C-kit突变的GIST,正常胃肠道组织和神经鞘瘤:突变与C-kit蛋白表达之间没有显著相关性(P=0.5332),而突变与PDGFRα蛋白表达之间呈显著相关性(P<0.0001).结论:GIST中PDGFRα和C-kit突变在部分GIST肿瘤发生过程中发挥了重要作用;突变位点与起源部位和组织学类型有关;大多GIST中蛋白表达与其基因突变关系密切.     

Elevated expression of G_sα in intrahepatic cholangiocarcinoma associates with poor prognosis

BACKGROUND:The stimulatory G protein α subunit(Gsα)plays important roles in diverse cell processes including tu morigenesis. Activating mutations in Gsα gene(GNAS) have been reported to be associated with poor prognosis in various human carcinomas. Furthermore, Gsα signaling is crucial in promoting liver regeneration by interacting with growth factor signaling, indicating that Gsα might play a promoting role in cancer development. However, little is known about the correlation between Gsα levels and clinicopathological pa rameters in intrahepatic cholangiocarcinoma(ICC). METHODS:We performed immunoblotting to examine the expression levels of Gsα and Ki67 proteins in tumor tissues and the corresponding adjacent tissues. A total of 74 pair of specimens resected from 74 ICC patients were examined. The association between Gsα levels and clinicopathological find ings and prognosis of the patients was evaluated.RESULTS:Western blotting demonstrated that the expression of Gsα was significantly higher in ICC tissues compared with that in their corresponding adjacent tissues. Gsα protein was highly expressed in about half of ICC tissues(48.6%, 36/74)while only 28.4%(21/74) of tumor adjacent tissues showed Gsα high expression(P=0.011). High Gsα expression in ICC was significantly associated with the numbers of tumor nodules(P=0.037) and lymph node metastases(P=0.010)Moreover, the level of Gsα was significantly and positivelycorrelated with Ki67 expression(P0.001). In addition, the recurrence-free survival rate and overall survival rate in the Gsα high group were significantly lower than those in the Gsα low group(P=0.004 and P=0.005, respectively).CONCLUSIONS:High Gsα expression is correlated with poor prognosis in ICC patients. Gsα might serve as a potential prognostic indicator of ICC.     

Takotsubo syndrome: the broken-heart syndrome

Takotsubo syndrome – also known as broken-heart syndrome, Takotsubo cardiomyopathy, and stress-induced cardiomyopathy – is a recently discovered acute cardiac disease first described in Japan in 1991. This review aims to update understanding on the epidemiology, pathophysiology, clinical presentation, diagnosis, and treatment of Takotsubo syndrome, highlighting aspects of interest to cardiologists and general practitioners.Key words: broken-heart syndrome, stress cardiomyopathy, Takotsubo cardiomyopathy, Takotsubo syndrome     

Myelodysplastic syndrome accompanied by Evans syndrome

Various cases of myelodysplastic syndrome (MDS) with diverse immunological disorders have been reported by many investigators. In this case report, we present a 70-year-old woman who had been diagnosed as having MDS and liver cirrhosis (LC) type C for 20 months, and who finally developed autoimmune phenomena against autologous blood cells. She was admitted to our hospital in order to evaluate her advanced anemia, thrombocytopenia and fatigue. The laboratory data at admission were as follows: hemoglobin 5.3 g/dl, red blood cell count 109 x 10(4)/microliter, white blood cell count 1,760/microliter, platelet count 4.3 x 10(4)/microliter and reticulocyte count 1.3%. The direct Coombs test was positive. In addition, anti-platelet antibody was positive, using the MPHA method. With these results, Evans syndrome secondary to MDS or LC was diagnosed. The mechanisms for the development of immunological disorders in patients with MDS or LC have not been fully elucidated. To our knowledge, this patient is one of the rare cases with MDS and Evans syndrome reported in the literature. During the generation process of autoantibodies, the role of HCV antigen in the pathogenesis of Evans syndrome was of interest in this patient.     

Broken-heart syndrome (Takotsubo syndrome)

We report on the rare case of partial anomalous return of four pulmonary veins in the right atrium and superior vena cava with intact interatrial septum in a five-year-old child. There were few symptoms in contrast with the left ventricular output dependent on the flow of the left upper lobe vein and from the lingula. Reduced compliance to the left led to a severe picture of pulmonary venocapillary hypertension in the immediate postoperative period, mitigated by an 8-mm interatrial septal defect. The patient progressed well after the intervention.     

Sweet's syndrome associated with myelodysplastic syndrome

A 49-year-old man was hospitalized because of cutaneous plaques and pancytopenia. Hematological findings, and the skin eruption suggested Sweet's syndrome associated with myelodysplastic syndrome (refractory anemia with excess of blasts; RAEB). Treatment for pancytopenia was attempted without effect. Also we tried treatment with antibiotics. The skin lesions healed and the body temperature returned to normal. This case was unusual in the association of myelodysplastic syndrome with Sweet's syndrome.     

Cronkhite-Canada syndrome associated with myelodysplastic syndrome

We report a case of Cronkhite-Canada syndrome (CCS) associated with myelodysplastic syndrome (MDS). A 54-year-old woman, diagnosed as MDS the prior year after evaluation of anemia, visited our hospital with the chief complaint of epigastric discomfort. She also had dysgeusia, alopecia, atrophic nail change, and pigmentation of the palm, all of which began several months ago. Blood tests revealed severe hypoalbuminemia. Colonoscopy (CS) showed numerous, dense, red polyps throughout the colon and rectum. Biopsy specimens showed stromal edema, infiltration of lymphocytes, and cystic dilatation of the crypt. Her clinical manifestations and histology were consistent with CCS. We prescribed corticosteroids, which dramatically improved her physical findings, laboratory data, and endoscopic findings. This is the first report of CCS in a patient with MDS.