RYR2基因与心脏性猝死的相关性研究

目的探寻RYR2基因的变异位点G1886S,讨论其与心脏性猝死(sudden cardiac death,SCD)的关系。方法提取SCD组及健康对照组血样的基因组DNA,采用PCR法扩增G1886S基因编码区外显子、外显子-内含子交界区以及3′侧翼区序列,直接进行DNA测序以明确遗传变异类型,并进行基因型频率和等位基因频率的统计学分析。结果在SCD组检测到2个变异位点,后者在SCD组合对照组中基因型分布和等位基因频率存在差异,并具有统计学意义(P0.05)。结论 RYR2基因变异位点G1886S与中国人SCD的发生的具有相关性。     

IP_3R、RYR与Ca~(2+)信号

Ca~(2+)在生命活动中起着至关重要的作用。细胞接受外界刺激后,通过胞膜转导,将信息传入胞内。胞内两大Ca~(2+)通道家族——三磷酸肌醇受体(IP_3R)和斯里兰卡向桂碱(ryanodine,RY)受体(RYR)将胞内信息以周期性的Ca~(2+)波动或振动编码,并藉此形式将所载信息传递给相应的受体,从而诱导复杂的生物学应答。本文在介绍IP_3R和 RYR cDNA克隆、受体结构与功能的关系及其活性调节的基础上,讨论IP_3R和RYR介导胞内Ca~(2+)信号产生及传递的分子机制。     

siRNA下调RYR1表达对小鼠成肌细胞中线粒体的影响

目的:探讨雷诺丁受体1(RYR1)表达下调对小鼠成肌细胞C2C12中线粒体的影响及其发生机制。方法:采用小干扰RNA(siRNA)敲减C2C12细胞的RYR1表达,应用透射电镜对线粒体进行体视学分析,观察细胞内线粒体数目和形态学的改变,应用real-time PCR和Western blot方法检测线粒体融合蛋白2(Mfn2)、过氧化物酶体增殖物激活受体γ辅激活因子1α(PGC-1α)和细胞外信号调节激酶1/2(ERK1/2)的mRNA及蛋白水平的改变。结果:RYR1敲减(KD)组RYR1的mRNA水平显著降低(P0.01)。阴性对照(NC)组及空白对照(BC)组线粒体维持长管状结构,而KD组线粒体呈碎片化改变。与NC组相比,KD组的线粒体数目呈增加趋势(差异无统计学显著性),线粒体面积和周长显著减少(P0.05)。KD组的Mfn2在mRNA和蛋白水平均显著降低(P0.01),而PGC-1α在mRNA水平显著降低(P0.01),在蛋白水平未见明显差异;ERK1/2在mRNA水平和蛋白水平的差异均无统计学显著性,也未检测到磷酸化ERK1/2的水平变化。结论:敲减RYR1表达可以导致C2C12细胞线粒体的形态改变,Mfn2表达下调可能参与其发生,而PGC-1α及ERK1/2相关的氧化应激通路可能在其中不发挥主要作用。     

1个中央轴空病家系RYR1基因的突变分析

目的 对一个常染色体显性遗传的中央轴空病(CCD)家系进行基因诊断,探讨家系中CCD患者可能的致病机制以及基因型与表现型的关系.方法 对先证者进行病史和家族史询问以及详细的临床检查.采集先证者及其家属的外周血样本,用PCR方法扩增理阿诺碱受体1(RYR1)基因C端突变热点区(外显子90-104)的编码序列,进行序列测定,与数据库中的参考序列进行比对分析.结果 先证者及其母亲、妹妹RYR1基因第102外显子均发生了第14690位碱基G到A的点突变,此突变会导致氨基酸改变,即G4897D,家系内正常成员以及家系外的50名正常对照均未发现该突变位点.结论 本实验所研究的家系中,RYR1基因第102外显子G14690A的杂合突变为致病基因,该基因突变可能导致不同的临床表现和病理改变.     

Variable phenotype of del45-55 Becker patients correlated with nNOSμ mislocalization and RYR1 hypernitrosylation

Duchenne and Becker muscular dystrophies (DMD and BMD) are muscle-wasting diseases caused by mutations in the DMD gene-encoding dystrophin. Usually, out-of-frame deletions give rise to DMD, whereas in-frame deletions result in BMD. BMD patients exhibit a less severe disease because an abnormal but functional dystrophin is produced. This is the rationale for attempts to correct the reading frame by using an exon-skipping strategy. In order to apply this approach to a larger number of patients, a multi-exon skipping strategy of exons 45-55 has been proposed, because it should correct the mRNA reading frame in almost 75% of DMD patients with a deletion. The resulting dystrophin lacks part of the binding site for the neuronal nitric oxide synthase (nNOSμ), which normally binds to spectrin-like repeats 16 and 17 of the dystrophin. Since these domains are encoded by exons 42-45, we investigated the nNOSμ status in muscle biopsies from 12 BMD patients carrying spontaneous deletions spaning exons 45-55. We found a wide spectrum of nNOSμ expression and localization. The strictly cytosolic mislocalization of nNOSμ was associated with the more severe phenotypes. Cytosolic NO production correlated with both hypernitrosylation of the sarcoplasmic reticulum calcium-release-channel ryanodine receptor type-1 (RyR1) and release of calstabin-1, a central hub of Ca(2+) signaling and contraction in muscle. Finally, this study shows that the terminal truncation of the nNOS-binding domain in the 'therapeutic' del45-55 dystrophin is not innocuous, since it can perturb the nNOS-dependent stability of the RyR1/calstabin-1 complex.     

Expression and regulation of αB-crystallin in the kidney in vivo and in vitro

αB-crystallin, a major component of the mammalian eye lens, is a small heat shock protein and molecular chaperone that is also abundant in the mammalian kidney. The present study aimed to characterize more closely the intrarenal expression and regulation of αB-crystallin in vivo and in vitro. In normal rat kidney, the expression of αB-crystallin mRNA and protein were both close to the detection limit in cortex, but increased steeply from the outer to the inner medulla where αB-crystallin constitutes approximately 2% of total tissue protein. Immunohistochemistry disclosed papillary collecting duct cells and thin limbs as the major sites for intrapapillary αB-crystallin immunoreactivity. In rats subjected to sucrose diuresis for 3 days, αB-crystallin mRNA expression was reduced by 27 and 46% in outer and inner medulla, respectively. In agreement with the results obtained in vivo, in Madine–Darby canine kidney cells, αB-crystallin mRNA and protein were induced significantly by elevating the medium osmolality to 500 mosm/kg H₂O by the addition of NaCl and raffinose, and also by urea. The NaCl-induced increase in αB-crystallin expression was concentration-dependently blunted by SP600125, a specific JNK inhibitor. Overexpression of αB-crystallin in 293 cells resulted in increased tolerance to acute osmotic stress. These results indicate that αB-crystallin may be regulated by papillary interstitial tonicity in a JNK-dependent process. Moreover, the high abundance of αB-crystallin in the renal medulla may be important for cell survival in an environment characterized by extreme interstitial solute concentrations as present during antidiuresis.     

Hepatitis E in liver transplant recipients in the Rhône-Alpes region in France

Purpose

In developed countries, hepatitis E virus (HEV) is considered an emerging pathogen, but prevalence seems highly variable according to previous European studies. As HEV can lead to chronic infections in immunosuppressed patients, it is thus essential to evaluate the prevalence and incidence of this infection.

Methods

We determined retrospectively, in a cohort of 206 pediatric and adult liver transplant recipients from the Rhône-Alpes region in France, pre-transplant anti-HEV-IgG prevalence and incidence of HEV infections during post-transplant follow-up (HEV IgG and IgM ± HEV-RNA).

Results

Transplantations were carried out between 2005 and 2012 and mean post-transplant follow-up was 32.8 months. Global pre-transplant prevalence of anti-HEV IgG was 29 %, increasing regularly with age from 7 % for children under 15 to 49 % for patients older than 60. From the 142 seronegative patients before transplant, 11 seroconversions (7.7 %) were observed during follow-up (incidence of 2.83 cases per 100 person-years). HEV RNA—tested at transaminases peak or randomly—was detected in only one case of seroconversion. For at least 2 HEV-seropositive patients, who had negative RNAemia before transplantation, viral RNA was detected chronically during follow-up, suggesting reinfection with HEV.

Conclusion

Acute infections were largely more frequent than chronic infections and were asymptomatic or misdiagnosed, suggesting that liver transplant patients may not be particularly prone to developing severe HEV hepatitis. In addition, the presence of IgG anti-HEV may not protect against re-infection. Serological testing, therefore, appears to be of limited interest for the diagnosis of HEV infections in liver transplant recipients.     

Changes in PaO_2 and pH in experimental hepatocarcinoma

Changes in PaO_2 and pH in experimental hepatocarcinoma     

Working Memory in Bees: Also in Flies?

Abstract: Decision making requires reference to both actual and remote information in the context of the requirements of the animal. Here, I explore a cognitive approach to decision making in honeybees and ask the question whether flies may share the faculties observed in bees. Examples are drawn primarily from natural behavior in bees, particularly from navigation and communication. I conclude that studies in Drosophila learning and memory in the tradition of Martin Heisenberg may gain from cognitive concepts, meaning that the “internal doing” of the brain should be included in the search for the neural basis of decision making.     

Ultrasonics in Medicine

Aug.17At RoomPm 13,00一15,00,15,30一17,00No.7(208)CO一CHAIRMAN Prof。Gao ShangkaiProf。Tsuyoshi ShiinaTITLEABSTRACT PAGES‘尹eial ultrasound probes for eardiae and eardiovaseular diagnosis N .BomFast reeonstru、tion method of refleetion mode difraetiontomographyu几der limited angle eondition T而yoshi Shiina,et al.··········.·..............……。.......……。.Reeonstruetion of the left and right ventrieles and ealeulation of467468CHINESE J.BIOMED.ENG.VOL.2 NO…     

Surgical pathology in sub-Saharan Africa—volunteering in Malawi

The breadth of material found in surgical pathology services in African countries differs from the common spectrum of “the West”. We report our experience of a voluntary work in the pathology departments of Blantyre and Lilongwe, Malawi. During a 6-week period, 405 cases (378 histology and 27 cytology cases) were processed. The vast majority showed significant pathological findings (n?=?369; 91.1 %): 175 cases (47.4 %) were non-tumoral conditions with predominance of inflammatory lesions, e.g., schistosomiasis (n?=?11) and tuberculosis (n?=?11). There were 39 (10.6 %) benign tumors or tumor-like lesions. Intraepithelial neoplasia of the cervix uteri dominated among premalignant conditions (n?=?15; 4.1 %). The large group of malignancies (n?=?140; 37.9 %) comprised 11 pediatric tumors (e.g., rhabdomyosarcoma, small blue round cell tumors) and 129 adult tumors. Among women (n?=?76), squamous cell carcinomas (SCCs) of the cervix uteri predominated (n?=?25; 32.9 %), followed by breast carcinomas (n?=?12; 15.8 %) and esophageal SCC (n?=?9; 11.8 %). Males (n?=?53) most often showed SCC of the esophagus (n?=?9; 17.0 %) and of the urinary bladder (n?=?7; 13.2 %). Lymphomas (n?=?7) and Kaposi's sarcomas (n?=?6) were less frequent. Differences compared to the western world include the character of the conditions in general, the spectrum of inflammatory lesions, and the young age of adult tumor patients (median 45 years; range 18–87 years). Providing pathology service in a low-resource country may be handicapped by lack of personnel, inadequate material resources, or insufficient infrastructure. Rotating volunteers offer a bridge for capacity building of both personnel and the local medical service; in addition, the volunteer's horizons are broadened professionally and personally.     

Vascularization in Ornamented Osteoderms: Physiological Implications in Ectothermy and Amphibious Lifestyle in the Crocodylomorphs?

Vascularization in the core of crocodylian osteoderms, and in their superficial pits has been hypothesized to be a key feature involved in physiological thermoregulation and/or acidosis buffering during anoxia (apnea). However, up to now, there have been no quantitative data showing that the inner, or superficial, blood supply of the osteoderms is greater than that occurring in neighboring dermal tissues. We provide such data: our results clearly indicate that the vascular networks in both the osteoderms and the pits forming their superficial ornamentation are denser than in the overlying dermis. These results support previous physiological assumptions and indicate that vascularization in pseudosuchian (crocodylians and close relatives) ornamented osteoderms could be part of a broad eco‐physiological adaptation towards ectothermy and aquatic ambush predation acquired by the crocodylomorphs during their post‐Triassic evolution. Moreover, regressions demonstrate that the number of enclosed vessels is correlated with the sectional area of the cavities housing them (superficial pits and inner cavities). These regressions can be used to infer the degree of vascularization on dry and fossilized osteoderms and thus document the evolution of the putative function of the osteoderms in the Pseudosuchia. Anat Rec, 2017. © 2017 Wiley Periodicals, Inc. Anat Rec, 301:175–183, 2018. © 2017 Wiley Periodicals, Inc.     

What future for dissection in courses of human topographical anatomy in universities in the UK?

In the United Kingdom most medical schools have traditionally included dissection as a major component of their anatomy courses. There is a dearth of substantive literature which can be used to demonstrate the educational values of dissection, although many authors have expressed opinions. Current scrutiny of the role of dissection has been prompted by many influences acting on medical schools in the UK, including changes in the medical curriculum promoted by the General Medical Council, changes in the mechanisms of funding for universities and their courses, and the introduction of research assessments and appraisal of teaching. It is probable that in the UK dissection will continue to decline but that its reduced role will be prompted by the interactions of many complicated processes, only some of which will be educationally driven. © 1995 WiIey-Liss, Inc.     

Deficits in adaptive upper limb control in response to trunk perturbations in Parkinson’s disease

The ability of patients with Parkinsons disease (PD) to compensate for unexpected perturbations remains relatively unexplored. To address this issue PD subjects were required to compensate at the arm for an unexpected mechanical perturbation of the trunk while performing a trunk-assisted reach. Twelve healthy and nine PD subjects (off medication) performed trunk-assisted reaching movements without vision or knowledge of results to a remembered target in the ipsilateral (T1) or contralateral (T2) workspace. On 60% of the trials trunk motion was unrestrained (free condition). On the remaining 40% of randomly selected trials trunk motion was arrested at movement onset (blocked condition). If subjects appropriately changed arm joint angles to compensate for the trunk arrest, there should be spatial and temporal invariance in the hand trajectories and in the endpoint errors across conditions. The control group successfully changed their arm configuration in a context-dependent manner which resulted in invariant hand trajectory profiles across the free and blocked conditions. More so, they initiated these changes rapidly after the trunk perturbation (group mean 70 ms). Some PD subjects were unable to maintain invariant hand paths and movement errors across conditions. Their hand velocity profiles were also more variable relative to those of the healthy subjects in the blocked-trunk trials but not in the free-trunk trials. Furthermore, the latency of compensatory changes in arm joint angles in movements toward T1 was longer in the PD group (group mean 153 ms). Finally, PD subjects arm and trunk were desynchronized at movement onset, confirming our previous findings and consistent with PD patients known problems in the sequential or parallel generation of different movement components. The findings that individual PD subjects were unsuccessful or delayed in producing context-dependent responses at the arm to unexpected perturbations of the trunk suggests that the basal ganglia are important nodes in the organization of adaptive behavior.