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91.
Cerebral cavernous malformations (CCMs; OMIM 116860) are vascular anomalies mostly located in the central nervous system (CNS) and occasionally within the skin and retina.  相似文献   
92.
Mayer-Rokitansky-Kuster-Hauser (MRKH) is a malformation complex comprising absent vagina and absent or rudimentary uterus. MRKH syndrome may be attributed to an initial affection of the intermediate mesoderm consequently leading (by the end of the 4th week of fetal life) to an alteration of the blastema of the cervicothoracicsomites and the pronephricducts. These latter subsequently induce the differentiation of the mesonephric and then the Wolffian and Mullerian ducts. There are very sparse such cases reported. We present a case of type II MRKH or Mullerian renal cervical somite association (i.e., Mullerian duct aplasia, renal dysplasia, and cervical somite anomalies).  相似文献   
93.
A transient fluid–structure interaction (FSI) model of a congenitally bicuspid aortic valve has been developed which allows simultaneous calculation of fluid flow and structural deformation. The valve is modelled during the systolic phase (the stage when blood pressure is elevated within the heart to pump blood to the body). The geometry was simplified to represent the bicuspid aortic valve in two dimensions. A congenital bicuspid valve is compared within the aortic root only and within the aortic arch. Symmetric and asymmetric cusps were simulated, along with differences in mechanical properties. A moving arbitrary Lagrange–Euler mesh was used to allow FSI. The FSI model requires blood flow to induce valve opening and induced strains in the region of 10%. It was determined that bicuspid aortic valve simulations required the inclusion of the ascending aorta and aortic arch. The flow patterns developed were sensitive to cusp asymmetry and differences in mechanical properties. Stiffening of the valve amplified peak velocities, and recirculation which developed in the ascending aorta. Model predictions demonstrate the need to take into account the category, including any existing cusp asymmetry, of a congenital bicuspid aortic valve when simulating its fluid flow and mechanics.  相似文献   
94.
Hox genes are recognized for their explanatory power of bilateral development. However, relatively little is known about natural variation in, and the evolutionary dynamics of, Hox genes within wild populations. Utilizing a natural population of sand lizards (Lacerta agilis), we screened HoxA13 for genetic variation and an association with incidence of offspring malformations. We found significant effects of parental genetic similarity and offspring sex, and their interaction, on risk of hatching malformed as an offspring. We also found within population genetic variation in HoxA13, and identified a significant effect of a three-way interaction among Hox genotype, parental genetic similarity, and offspring sex on the risk of hatching malformation. Since malformed offspring in this population do not survive to maturity, this study reveals complex and ongoing selection associated with Hox genes in a wild reptile population. Importantly, this demonstrates the utility of natural populations in unveiling microevolutionary processes shaping variation in highly conserved genes.  相似文献   
95.
Infection of mango panicles and young leaf shoots by Fusarium results in significantly lower fruit yields. Some mango cultivars are known to be tolerant to blossom malformation, while others are highly susceptible. Previous researchers linked the ability of certain cultivars to confine Fusarium infection to the production of high levels of mangiferin. This study further elucidates the role of phenolic metabolites contributing to tolerance. Phenolic profiles of mature leaf extracts from cultivars with varying degrees of resistance to Fusarium infection were obtained by ultrahigh performance liquid chromatography–time-of-flight-mass detection. Chemometric models constructed from the data revealed a clear distinction between the profiles of tolerant and susceptible cultivars and permitted the identification of biomarkers associated with susceptibility to infection. The presence of elevated levels of mangiferin, maclurin and maclurin O-galloyl-glucoside in the leaves were associated with a higher degree of tolerance. In contrast, high levels of iriflophenone glucosides were linked to increased susceptibility of the cultivars to infection. These models can serve as an important tool to investigate appropriate cultivars, prior to their introduction to areas prone to the disease.  相似文献   
96.
目的:探讨非手术治疗脑动静脉畸形患者的临床预后。方法:选择129例脑动脉畸形患者并根据治疗方法将其分为非手术治疗组、手术治疗组、血管内栓塞治疗组、血管内栓塞治疗+手术治疗组,对各组的患者进行随访,将随访结果分为无症状、好转、脑出血以及死亡,分析和比较不同治疗方法治疗患者的随访结果。结果:手术组愈后无症状13例,好转29例,死亡1例;血管内栓塞组愈后无症状22例,好转21例,死亡1例;血管内栓塞联合手术治疗组愈后无症状5例,好转4例,死亡1例;非手术治疗组愈后无症状11例,好转20例,新发脑出血1例,无死亡。各治疗组之间的愈后比较差异无统计学意义(P0.05)。结论:本研究中32例未手术治疗患者在随访期内,愈后与其他治疗组结果未见明显差异。脑动静脉畸形的发病机制及疾病自然转归,值得深入研究探讨。  相似文献   
97.
Aortic arch malformations are common congenital disorders that are frequently of unknown etiology. To gain insight into the factors that guide branchial aortic arch development, we examined the process by which these vessels assemble in wild type zebrafish embryos and in kurzschlusstr12 (kustr12) mutants. In wild type embryos, each branchial aortic arch first appears as an island of angioblasts in the lateral pharyngeal mesoderm, then elaborates by angiogenesis to connect to the lateral dorsal aorta and ventral aorta. In kustr12 mutants, angioblast formation and initial sprouting are normal, but aortic arches 5 and 6 fail to form a lumenized connection to the lateral dorsal aorta. Blood enters these blind-ending vessels from the ventral aorta, distending the arteries and precipitating fusion with an adjacent vein. This arteriovenous malformation (AVM), which shunts nearly all blood directly back to the heart, is not exclusively genetically programmed, as its formation correlates with blood flow and aortic arch enlargement. By positional cloning, we have identified a nonsense mutation in unc45a in kustr12 mutants. Our results are the first to ascribe a role for Unc45a, a putative myosin chaperone, in vertebrate development, and identify a novel mechanism by which an AVM can form.  相似文献   
98.
硫代硫酸钠干扰斑马鱼胚胎发育并致畸   总被引:3,自引:0,他引:3  
硫的衍生物潜在的威胁着胚胎的发育过程.斑马鱼被用于研究不同浓度(1×10-6~1 mol/L)的硫代硫酸钠(sodium thiosulfate, STS)对胚胎发育的影响,在解剖显微镜下实时观察斑马鱼胚胎发育的全过程.采用Western 印迹法检测乙酰化的微管蛋白——α-微管蛋白(acetylated tubulin, α-tubulin)和神经元增殖细胞核抗原(proliferating cell nuclear antigen,PCNA)的表达,分别检测STS暴露后胚胎的运动神经元功能,神经元的增殖状态.发育中的斑马鱼胚胎暴露于0.1~1 mol/L STS,呈现出严重的发育迟缓,并且伴随多脏器畸形;暴露于10 μmol/L~10 mmol/L STS,胚胎呈现循环系统,神经系统以及颌面部畸形.胚胎在48 hpf (hours post fertilization)时,对STS的暴露敏感高于24 hpf和96 hpf.STS可能干扰细胞的增殖及运动神经元的正常分化.STS可能干扰正常的细胞骨架结构,并在胚胎发育晚期影响细胞增殖,对胚胎神经系统、循环系统及颌面部有致畸作用.  相似文献   
99.
A novel transgenic mice model for venous malformation   总被引:1,自引:0,他引:1  
Vascular anomalies are most commonly seen in the head and neck region, and there is no animal model available of this disease until now. The purpose of this study was to construct a conditional murine polyomavirus middle T antigen gene (PyMT) transgenic mice model, in order to provide a basis for the treatment of vascular anomalies in vivo, as well as the study of PyMT's molecular function. A new conditional transgenic vector based on Tet-On system was constructed successfully. After the experiment in vitro, pronuclear microinjection method was used to introduce the purified transgene into the chromosomes of fertilized mice eggs, and five transgenic positive mice were obtained. The transgenic positive animals went down to future generation by hybridization. After induction of PyMT's expression in the F1 generation, three transgenic mice developed venous malformation which was confirmed histopathologically. The mice model generated could be used as a tool to study venous malformation, as well as the function of PyMT gene.  相似文献   
100.
We report three families with dominant unilateral renal adysplasia without vesico-ureteral reflux. No dysmorphia or anomalies were evident in the reproductive system. Ophthalmological examination excluded the presence of optic nerve coloboma or other ocular anomalies. No mutations were detected in the EMX(2) and in PAX(2) genes of affected members. Other homeobox genes could be responsible for this anomaly in these three families.  相似文献   
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