中国人常见非综合征性聋杂合子发病机制的实验研究

目的构建人野生型CX30红色荧光表达载体,将Cx26野生型和突变型分别与CX30共同转染HEK293细胞,为揭示Cx26--235delC的杂合突变患者的发病机制提供实验依据。方法构建pCx30--IREs2-DsRed—Express真核表达载体,将pcx30—IREs2-DsRed—ExPress分别与pCx26--EGFP或pCx26--235deIC--EGFP以1：1的比例用脂质体法转染HEK293细胞,转染48h后在激光共聚焦显微镜下观察结果,计算同时表达红色和绿色的细胞阳性率,卡方检验比较两组阳性率的差异。结果pCx30--IRES2--DsRed--Express与pCx26--EGFP共同转染HEK293细胞后,同时出现红色和绿色荧光的细胞占全部转染阳性细胞的27．32％（91／333）。pCx30—IRES2--DsRed--Express与pCx26--c235deIC--EGFP共同转染HEK293细胞后,同时表达红色与绿色信号的细胞占全部阳性细胞的2．19％（4／183）,明显低于两种野生型质粒共同转染的阳性率,经卡方检验两者差异具有显著性意义（x2=52．89,P〈0．01）。结论Cx26发生C．235deIC突变后,丧失了与野生型Cx30形成异型性缝隙连掇gapjunctions,GJs）的能力,使异型性GJs的总数显著下降,导致耳蜗失去了重要的细胞间联系通道,推测可能与部分c．235delC杂合子耳聋的发生有关。     

16q-linked autosomal dominant cerebellar ataxia: a clinical and genetic study

The autosomal dominant cerebellar ataxias (ADCAs) comprise a genetically and clinically heterogenous group of neurodegenerative disorders. Very recently, a C-to-T single nucleotide substitution in the puratrophin-1 gene was found to be strongly associated with a form of ADCA linked to chromosome 16q22.1 (16q-linked ADCA; OMIM 600223). We found the C-to-T substitution in the puratrophin-1 gene in 20 patients with ataxia (16 heterozygotes and four homozygotes) and four asymptomatic carriers in 9 of 24 families with an unknown type of ADCA. We also found two cases with 16q-linked ADCA among 43 sporadic patients with late-onset cortical cerebellar atrophy (LCCA). The mean age at onset in the 22 patients was 61.8 years, and that of homozygous patients was lower than that of heterozygous ones in one family. Neurological examination revealed that the majority of our patients showed exaggerated deep tendon reflexes in addition to the cardinal symptom of cerebellar ataxia (100%), and 37.5% of them had sensorineural hearing impairment, whereas sensory axonal neuropathy was absent. The frequency of 16q-linked ADCA was about 1/10 of our series of 110 ADCA families, making it the third most frequent ADCA in Japan.     

肾细胞癌3p21杂合子丢失的分子病理研究

应用聚合酶链反应－限制性片段长度多态性分析技术检测３１例非乳头状肾细胞癌３ｐ２１杂合子丢失。结果显示：肾细胞癌中３ｐ２１杂合子率为３８．７％，杂合子丢失率为６６．７％。杂合子丢失阳性患者的５年存活率为２５．０％，而杂合子丢失阴性和纯合子未丢失患者的５年存活率为６５．２％，二者比较，差异有显著性（Ｐ＜０．０５）。提示３ｐ２１杂合子丢失可能与非乳头状肾细胞癌的演化及预后有关。     

重组表达载体plRES Rb94的构建及其对肺腺癌A549细胞株中SphK表达的影响

目的构建真核表达质粒pIRES Rb94,观察Rb94基因对鞘氨醇激酶（SphK）表达的影响。方法根据Rb94基因序列设计、合成引物,构建以内部核糖体进入位点（IRES）相连的Rb94基因的真核表达质粒pIRES Rb94,经脂质体转染A549细胞,G418筛选获得稳定转染的细胞株。采用Real time RT PCR和Western boltting法检测Rb94基因并观察其对人肺腺癌A549细胞株SphK表达的影响。结果成功构建重组表达质粒pIRES Rb94,转染A549细胞后获得稳定转染细胞株pIRES Rb94 A549,该细胞株中Rb94基因高效表达;SphK1表达下调而SphK2表达上调。结论真核表达质粒pIRES Rb94构建成功并可有效转染A549细胞,Rb94基因抑制SphK1的表达,增强SphK2的表达。     

遗传性痉挛性截瘫一家系的临床特点与遗传学分析

目的 探讨遗传性痉挛性截瘫(HSP)一家系的基因型和临床特点.方法 抽取1个HSP家系15名成员外周血,选择与已知HSP致病基因位点在物理距离上紧密连锁的微卫星分子进行标记[短串联重复序列(STR)],连锁分析并构建单体型.对患者进行观察,行心肌酶学、肌电图以及头颅、颈髓、胸髓MRI检查,总结其临床特点.结果 家系成员SIR的扩增产物进行基因分型,连锁分析发现与HSP 31型(SPG31)位点连锁,2个SIR(D2S2951、D2S2333)最大LOD值为1.8,表明连锁.经过连锁分析后得到的对应致病基因为REEP1基因,经过突变筛查发现了1个REEP1 c417+1G＞A杂合突变.SPG31临床特点以痉挛步态、下肢肌张力增高为主要表现,MRI显示胸髓萎缩.结论 SPG31患者临床特征表现为典型的HSP特征,致病基因为REEP1基因,存在REEP1 c417+1G＞A杂合突变.     

Energetic efficiency under stress underlies positive genetic correlations between longevity and other fitness traits in natural populations

Evolutionary relationships among fitness traits are considered in terms of the near-to-universal scenario of stressful environments leading to a resource-deficient and hence energy-deficient world. Fitness approximates to energetic (and metabolic) efficiency under this environmental model. When fitness is high, stress resistance (reducible to oxidative-stress resistance) and metabolic stability are maximal, and energy expenditure is minimal. Rapid development should then be favored followed by a long lifespan and high adult survival. Positive associations among diverse fitness or life-history traits are expected, controlled by stress-resistant ‘good genotypes’. Heterozygotes tend to show higher energetic efficiency and hence higher fitness than do corresponding homozygotes under extreme environments, and to give parallel associations among life-history traits. Energy budgets under abiotic environments are pivotal for integrative evolutionary studies of life histories in natural populations.     

多重连接探针扩增法检测和识别脊柱肌肉萎缩症的纯合型或杂合型SMN基因缺失(英文)

Spinalmuscularatrophy (SMA)isanautosomalreces siveneuromusculardegenerationoftheanteriorhorncellsofthespinalcordandbrainstem .Thisdegenerationresultsinoneofthemostcommondiseasesrelatedtomusclefatigueandatrophy[1] .SMAdiseasesareclassifiedintofourcategorie…     

An activated renin-angiotensin system maintains normal blood pressure in aryl hydrocarbon receptor heterozygous mice but not in null mice

It has been postulated that fetal vascular abnormalities in aryl hydrocarbon receptor null (ahr^−/−) mice may alter cardiovascular homeostasis in adulthood. We tested the hypothesis that blood pressure regulation in adult heterozygous mice (ahr^+/−) would be normal, compared to ahr^−/− mice, since no vascular abnormalities have been reported in the heterozygote animals. Mean arterial blood pressure (MAP) was measured using radiotelemetry prior to and during treatment with inhibitors of the autonomic nervous system, nitric oxide synthase (NOS), angiotensin converting enzyme (ACE), or endothelin-1 A receptor (ET_A). Also, indices of renin-angiotensin system (RAS) activation were measured. ahr^+/− and ahr^−/− mice were normotensive and hypotensive, respectively, compared to wild-type (ahr^+/+) littermates. Responses of all genotypes to autonomic nervous system inhibition were normal. ahr^+/− mice responded normally to NOS inhibition, while the responses of ahr^−/− mice were significantly blunted. In contrast, ahr^+/− mice were significantly more responsive to inhibition of ACE, an ET_A antagonist, or both, while ahr^−/− mice were significantly less responsive to ACE inhibition and more responsive to an ET_A antagonist. ahr^+/− mice also exhibited significant increases in plasma renin and ACE activity, plasma sodium, and urine osmolality, indicative of RAS activation. Thus, normotension in ahr^+/− mice appears to be maintained by increased RAS and ET-1 signaling, while hypotension in ahr^−/− mice may result from decreased RAS signaling. In conclusion, despite the lack of overt fetal vascular abnormalities in ahr^+/− mice, the loss of a single ahr allele has a significant effect on blood pressure regulation.     

Salla disease variant in a Dutch patient

A Dutch child with psychomotor retardation, impaired speech, ataxia, sialic acid storage and vacuolized skin fibroblasts and lymphocytes was diagnosed as having free sialic acid storage disease. Slight corneal opacities, pale optic disks at the fundus oculi and vertebral abnormalities, not earlier reported in Salla disease, were peculiar to this case. Free sialic acid was about tenfold increased in urine and cultured fibroblasts, without changes in the glycoconjugate-bound sialic acid pool. A subsequent pregnancy of the patient's mother was monitored by assay of sialic acid in chorionic villi and amniotic fluid. An unaffected foetus was predicted. Sialic acid was also assayed in peripheral blood total leucoyctes, and in mononuclear and polymorphonuclear (PMN) leucocyte subpopulations. Each of these leucocyte fractions from the patient showed 10- to 30-fold increase in sialic acid content. The PMN subpopulation provided the most restricted range of control values and showed slightly increased values for the patient's parents. These results suggest that the assay of sialic acid in PMN might be useful for the identification of heterozygotes in sialic acid storage disease. Studies on a larger number of obligate heterozygotes are needed to confirm this observation.     

串联质谱技术对苯丙酮尿症杂合子的检测

目的建立串联质谱技术测定血苯丙氨酸(Phe)和酪氨酸(Tyr)浓度方法,观察苯丙酮尿症(PKU)、PKU杂合子和正常对照组血Phe、Tyr浓度及其比值(Phe/Tyr)变化。方法研究对象为52例PKU患儿,152例PKU杂合子成人,160名正常成人作为对照。研究方法采用干血滤纸片法,血滤纸片经含已知浓度Phe和Tyr内标的甲醇萃取,盐酸正丁醇衍生后,用串联质谱仪分析。结果(1)样品回收率Phe在346μmol/L和485μmol/L浓度时分别为102%和100%,Tyr在276μmol/L和442μmol/L浓度时分别为103%和98%。(2)批内CVPhe为6.7%,Tyr为10.5%,批间CVPhe为12.2%,Tyr为9.9%。(3)PKU患者血Phe、Tyr浓度和Phe/Tyr值分别为(634.0±300.3)μmol/L、(41.9±16.3)μmol/L和16.5±9.9,PKU杂合子分别为(68.3±21.4)μmol/L、(40.1±11.8)μmol/L和1.7±0.4,对照组分别为(53.2±10.2)μmol/L、(43.6±9.5)μmol/L和1.2±0.2。PKU患者血Phe、Phe/Tyr值与PKU杂合子、对照组比较差异有统计学意义(P<0.01)。PKU杂合子与对照组比较,Phe、Phe/Tyr水平较高(均P<0.01),Tyr水平较低(P<0.01)。结论串联质谱技术能够准确测定干血滤纸片中Phe和Tyr浓度。PKU杂合子Phe浓度和Phe/Tyr值高于正常成人,但与正常人有明显的重叠。