升主动脉瘤明胶酶活性变化的实验研究

目的 探讨明胶酶在升主动脉瘤形成过程中的活性变化及意义. 方法 将35只Wistar大鼠随机分为对照组和实验组.采用升主动脉缩窄鼠制备升主动脉瘤模型.于术后3～5个月取升主动脉,应用明胶酶谱分析及薄膜原位酶谱法检测动脉瘤明胶酶的活性改变. 结果 正常动脉壁外膜无或极少有明胶酶活性;动脉瘤壁的中膜与外膜明胶酶活性明显增强. 结论 明胶酶活性升高可能在升主动脉瘤形成过程中起重要作用.     

Pitfalls in acid/base experiments with conscious dogs

Arterial pH and blood gases were measured at intervals in conscious dogs after their first human contact of the day. Blood was sampled through an indwelling catheter in the aorta without disturbing the animals. It appeared that in the first 90 min arterial PO₂, oxygen saturation and haemoglobin concentration significantly declined. PCO₂ and pH changed less consistently when the acid/base status of the dogs was normal, but when a non-respiratory acidosis was present there was a significant decrease in pH and a significant increase in PCO₂. Arterial pH and blood gases were also measured before and after feeding the animals. It appeared that an appreciable metabolic alkalosis developed within 2 h after a meal. The alkaline tide was accompanied by a trend to higher values for PCO₂. It is concluded that, after a period of seclusion, renewed human contact causes behavioural changes in a dog, which may result in appreciable transitory changes in arterial pH and blood gas values. Blood sampling from conscious dogs should therefore take place after a proper period of habituation; preferably, a few samples should be taken at intervals to check that a steady state has been reached. If possible, blood should be collected before feeding; in any case the relationship in time of blood sampling to feeding should be constant throughout.     

The cholesteryl ester transfer protein (CETP) locus as a candidate gene in abdominal aortic aneurysm

Abdominal aortic aneurysm (AAA) is a relatively common disease of the elderly presenting as progressive dilatation of the abdominal aorta. The condition shows a pronounced tendency to cluster in families, indicating a genetic component in the disease aetiology. We have screened the cholesteryl ester transfer protein (CETP) gene, which has been proposed as a candidate gene in AAA, by means of SSCP, DNA sequencing and restriction analysis in a cohort of patients with AAA and a matching control group drawn from the Irish population. The analysis has demonstrated sequence variation at four sites in the CETP gene: an A-T transversion in exon 9 (producing a Lys309-Stop codon substitution), a G-A transition in exon 14 (producing a conservative Va1421-Ile substitution), a C-T transition in intron 12 and a G-A transition in intron 15. None of the last three sites corresponded with sites of functional significance in the protein, suggesting that this reflects neutral polymorphism at the CETP locus. Furthermore, the frequencies of these four polymorphisms in the AAA patient and control groups were not significantly different. These data therefore suggest that CETP may be excluded as a candidate gene in abdominal aortic aneurysm.     

The genetic basis of Turner syndrome aortopathy

Our goal is to identify the genetic underpinnings of bicuspid aortic valve and aortopathy in Turner syndrome. We performed whole exome sequencing on 188 Turner syndrome study subjects from the GenTAC registry. A gene‐based burden test, SKAT‐O, was used to evaluate the data using bicuspid aortic valve (BAV) and aortic dimension z‐scores as covariates. This revealed that TIMP3 was associated with BAV and increased aortic dimensions at exome‐wide significance. It had been previously shown that genes on chromosome Xp contribute to aortopathy when hemizygous. Our analysis of Xp genes revealed that hemizygosity for TIMP1, a functionally redundant paralogue of TIMP3, increased the odds of having BAV aortopathy compared to individuals with more than one TIMP1 copy. The combinatorial effect of a single copy of TIMP1 and TIMP3 risk alleles synergistically increased the risk for BAV aortopathy to nearly 13‐fold. TIMP1 and TIMP3 are tissue inhibitors of matrix metalloproteinases (TIMPs) which are involved in development of the aortic valve and protection from thoracic aneurysms. We propose that the combination of TIMP1 haploinsufficiency and deleterious variants in TIMP3 significantly increases the risk of BAV aortopathy in Turner syndrome, and suggest that TIMP1 hemizygosity may play a role in euploid male aortic disease.     

牦牛主动脉瓣叶的流变学性质

作者研究了牦牛主动脉瓣叶的单向拉伸和应力松弛行为。发现在生理应变范围内,试件的应力应变曲线斜率在纤维方向比其垂直方向约大20倍,瓣叶对应变速率不很敏感。在分析瓣叶的松弛行为时应用了冯元桢[9](1972)提出的松弛模型,根据实验结果,得到了牦牛主动脉瓣叶的归一化松弛函数。     

Report of a child with aortic aneurysm,orofacial clefting,hemangioma, upper sternal defect,and Marfanoid features: Possible PHACE syndrome

We report a female patient who had a scalp hemangioma, a cleft uvula, an upper sternal defect, pectus excavatum, arachnodactyly, pes planus, and joint hypermobility. She had rupture of an aortic aneurysm after minor trauma at 11 years of age. At 17 years of age, elective repair of a dilated, ectatic aorta was complicated by cerebral ischemia. Other vascular abnormalities in the proband included an aneurysm of the left subclavian artery, atresia of the right carotid artery, and calcified cerebral aneurysms. We believe that the proband's physical anomalies are best described by the PHACE (posterior fossa brain malformations, hemangiomas, arterial anomalies, coarctation of the aorta and cardiac defects, and eye abnormalities) phenotypic spectrum. This spectrum of physical anomalies also includes sternal clefting and hemagiomas as part of the sternal malformation/vascular dysplasia (SM/VD) association, as found in our patient, and the acronym PHACES has also been used. We consider that the PHACE phenotypic spectrum is likely to be broader than previously recognized and includes orofacial clefting and aortic dilatation and rupture. Our patient also had skeletal anomalies that lead to consideration of Marfan syndrome as a diagnosis. It should be recognized that there is clinical overlap between PHACE syndrome and Marfan syndrome when aortic dilatation is present. We would also like to emphasize the minor nature of the cutaneous findings in our patient despite her severe vascular complications. This is in contrast to previous reports of large or multiple hemangiomas in PHACE syndrome. Published 2002 Wiley‐Liss, Inc.     

Ectopia lentis in Loeys‐Dietz syndrome type 4

Loeys‐Dietz syndrome is a heritable disorder of the connective tissue leading to multisystem involvement including craniofacial features, skeletal abnormalities, cutaneous findings and early‐onset and aggressive disease of the aorta and its branches. There are multiple types of Loeys‐Dietz syndrome related to pathogenic variants in TGFBR1, TGFBR2, SMAD3, TGFB2, and TGFB3. Individuals with Loeys‐Dietz syndrome may be misdiagnosed as having Marfan syndrome due to shared phenotypic features and aortic root dilation. However, ectopia lentis has been an important discriminating feature, being unique to Marfan syndrome and not reported to be associated with Loeys‐Dietz syndrome. We report the case of a 46‐year‐old woman with Loeys‐Dietz syndrome type 4 due to a pathogenic variant in TGFB2 who was diagnosed with ectopia lentis at age 44. The patient underwent whole exome sequencing and no other pathogenic variants were found to explain the ectopia lentis. Our findings indicate that ectopia lentis may be an uncommon finding in Loeys‐Dietz syndrome type 4 and emphasize the importance of genetic testing in familial thoracic aortic aneurysm disease.     

腹主动脉瘤腔内修复术后感染病原菌及Hippo信号通路基因改变

目的探讨腹主动脉瘤腔内修复术(EVAR)后医院感染病原特点及Hippo信号通路基因、白细胞介素-17(Interleukin-17,IL-17)、IL-23改变。方法选择天津医院血管外科2017年5月-2020年3月收治腹主动脉瘤EVAR术后医院感染患者49例作为感染组,选择同期医院进行EVAR术后未发生医院感染患者60例作为非感染组。采用实时荧光定量逆转录聚合酶链反应(RT-PCR)法检测Hippo通路基因yap、taz、mst1相对表达水平,采用酶联免疫吸附法检测其辅助型T细胞17(Th17)促炎细胞因子白细胞介素-17(IL-17)、IL-23水平。结果49例患者共发生肺部感染33例(67.35%),尿路感染10例(20.41%),手术切口感染4例(8.16%),移植物感染2例(4.08%);感染病原以革兰阳性菌为主,共25株,占51.02%,革兰阴性菌共22株,占44.90%,真菌2株,占4.08%;感染组yap、taz、mst1基因相对表达水平和IL-17、IL-23水平高于非感染组(P<0.05)。结论腹主动脉瘤EVAR术后医院感染以肺部感染、尿路感染为主,应及时予以针对性预防;Hippo通路参与了感染发生过程,通过Th17促炎途径诱导炎症反应,其机制仍有待研究。     

如何正确理解T_1T_2的不同

本文针对学生在学习核磁共振的过程中 ,在理解纵向弛豫时间T1和横向弛豫时间T2 时经常提出的疑问 ,建构两个物理模型 ,以便于学生能深刻理解T1、T2 的物理学 ,生物学意义 ,为读释图像 ,挖掘生物信息奠定更牢固的理论基础。     

侧脑室计算机三维重建及理论分析

目的 :建立便于推广、功能齐全、价廉的三维医学图像重建系统及进行三维重建。方法 :利用目前较先进的数码摄片技术和自行编制的软件系统 ,对层距 1.0 mm的人体头部断面共 2 4 0层进行侧脑室的三维重建 ,同时对头部整体行三维重建以其进行相对定位和比较。结果 :重建后的侧脑室可和头部进行参照显示 ,行旋转、透明处理和不同方向的任意剖割。结论 :较以 CT、MRI断面图像重建的模型增加了轮廓的准确性和器官内组织的鲜明色彩