脂膜超声造影剂增强兔肾VX2肿瘤显像及鉴别的实验研究

目的：评价声学造影剂脂氟显对兔肾VX2肿瘤增强显像效果。方法：14只接种过VX2肾肿瘤的模型兔，经耳缘静脉团注脂氟显0.02ml/kg；使用二次谐波显像模式观察记录造影过程；用定性视觉评分和灰阶视频定量方法分析造影效果。结果：肿瘤视觉增强从5s开始，持续时间10~15min。视觉评分在造影后与造影前比较有显著差异。灰阶视频密度定量分析造影后VX2肿瘤灰阶值显著小于正常肾皮质（P<0.05）。结论：脂膜超声造影剂能有效增强兔肾VX2肿瘤显像，对假阳性有一定的鉴别诊断价值。     

自制脂膜氟烷超声造影剂对实验性肾肿瘤显影效果的研究

目的　探讨自制脂膜氟烷超声造影剂“脂氟显”对兔肾VX2 肿瘤的显影效果。方法　对 16只肾肿瘤模型经兔耳缘静脉团注“脂氟显”0 .0 2ml/kg进行超声造影 ,并与增强CT、病理对照研究。结果　 16只兔肾病理检查共有5 1个肿瘤 ,超声造影后检出 46个 ,检出率 90 .1% ,增强螺旋CT检出 45个 ,检出率 88.2 %。超声造影和增强CT对模型兔肾肿瘤的检出率无统计学差异 (P >0 .0 5 ) ,两者漏诊的肿瘤直径均小于 0 .3 2cm。造影前超声假阳性 5个 ,假阳性率13 .8% ,CT平扫无假阳性。结论　超声造影剂“脂氟显”能有效增强兔肾肿瘤的显像 ,提高肾脏肿瘤的检出率和特异性 ,其诊断价值与增强螺旋CT相当     

一种新型声学造影剂对兔肾VX2肿瘤显像的实验研究

目的通过与增强CT对比研究评价本科实验室制作的声学造影剂"脂氟显"对兔肾VX2肿瘤显像的能力.方法 14只左肾种植有VX2肿瘤的家兔,超声造影前和造影后观察肿瘤的大小、数目和能发现的最小肿瘤,在24 h内做CT平扫和增强对照,实验完后处死动物与病理对照.结果 14只兔声学造影后共发现46个肿瘤,增强CT发现的肿瘤数为44个,P值0.336,相关系数r=0.988,病理肿瘤52,与声学造影比较P值0.082,相关系数r=0.978.声学造影能观察到最小肿瘤直径0.32 cm,增强CT发现的最小肿瘤直径0.32 cm,和病理比较无显著性差异.结论脂氟显能有效增强兔肾肿瘤的显像,提高肾脏肿瘤的检出率,与增强CT相当,对肾窦肿瘤优于增强CT.     

新型长效脂质声学造影剂增强兔肝脏VX2肿瘤的实验研究

目的　验证长效造影剂“脂氟显”在新西兰白兔 VX2 肝癌中的造影增强效果。方法　 12只患有 VX2 肝癌的新西兰白兔经耳缘静脉团注脂氟显 0 .0 2 ml/ kg;使用二次谐波显像模式观察记录造影过程 ;用定性视觉评分和定量视频密度分析造影效果。结果　肿瘤视觉增强效果从 10 s开始 ,持续时间长约 4 0～ 6 0 min。视觉评分在造影后 10、 2 0和 4 0 min与造影前比较有显著性差异 ,6 0 min则无明显差异。造影前后总体视觉效果有非常显著差异 (P<0 .0 1)。视频密度分析 ,造影后 10到 6 0 min的 VX2肿瘤灰阶值非常显著地小于正常肝组织 (P<0 .0 1)。结论　脂氟显能持续增强兔肝脏 VX2 肿瘤超声影像长达 4 0～ 6 0 min,优于多种同类声学造影剂。     

自制脂膜氟碳声学造影剂长时间增强组织灰阶显像的机理初探

目的：通过对比观察自制脂膜氟碳声学造影剂“脂氟显”对正常兔肝，肾灰阶显像的增强效果，探讨其增强机理。方法：10只健康家兔经耳缘静脉团注0.01ml/k的脂氟显，采用视觉评分，动态观察肝，肾的二维灰阶增强效果。结果：脂氟显对肝实质，肾皮质的灰阶显像均有长时间增强效果，明显增强时间超过50分钟。结论：脂氟显能长时间增强组织的灰阶显像，其机理主要与造影剂在毛细血管的潴留有关。     

颅脑声学造影评价脑实质出血的实验研究

目的 评价颅脑声学造影对脑出血的诊断价值。方法 在超声引导下制作实验犬急性脑实质出血模型。经外周静脉应用“脂氟显”(剂量为0．01ml／kg)进行颅脑声学造影。利用视频灰阶分析技术，测定脑出血血肿区、血肿边缘、正常脑组织三部分在造影前(即造影0 s)和造影30s、60s的灰阶值，绘制时间一强度曲线(time—intensity curve，TIC)。结果 脑实质血肿区造影前后灰阶值无变化，血肿边缘区域和正常脑实质造影后较造影前灰阶值明显升高，而且边缘区域显像增强更显著。结论 声学造影剂“脂氟显”的应用可以显著增强脑出血血肿周围脑实质显像，有利于区分血肿区、血肿边缘及正常脑实质。对临床脑实质出血的超声诊断具有潜在的重要价值。     

灰阶超声造影对正常肝实质及VX2肿瘤血流动力学的对照研究

目的 应用低机械指数灰阶超声造影定量研究肝恶性肿瘤及其周围肝实质血流动力学特点及其诊断价值。方法 分别经耳缘静脉对8只荷VX2肿瘤新西兰大白兔团注超声造影剂SonoVue（0．1ml／kg），应用低机械指数实时灰阶造影匹配成像技术和声学定量时间一强度曲线分析软件，定量分析兔VX2瘤及其周围肝实质血流动力学特点及造影增强效应。结果低机械指数灰阶超声造影可动态显示肝实质与肿瘤内造影剂的增强过程，其时间一信号强度曲线客观反映造影剂的渡越过程。与肝实质相比，VX2瘤造影剂开始增强时间和达到峰值时间均明显提前，分别为10．13s和17．48S，峰值强度较低，渡越时间明显缩短。VX2瘤与肝实质各造影定量参数间差异具有统计学意义（P〈0．01）。结论 低机械指数灰阶超声造影能很好地反映肝恶性肿瘤血流动力学变化，超声造影定量分析对肝恶性肿瘤的诊断有重要价值。     

低机械指数灰阶造影对肝VX2瘤动态期相性变化的研究

目的应用低机械指数灰阶超声造影研究肝恶性肿瘤的动态期相性增强变化规律及其诊断价值。方法分别经耳缘静脉对8只荷VX2瘤新西兰大白兔团注超声造影剂SonoVue（0．1ml／kg），应用CnTI低机械指数实时造影匹配成像技术，动态观察兔VX2瘤及其周围肝实质造影增强效应。结果在所有造影过程中，肝肿瘤及肝实质内造影剂随时间呈动态增强。VX2瘤动脉期明显强化，呈“灯泡征”，与周围肝组织灰阶对比明显；随后造影剂逐渐退出，肿瘤回声强度从与周围肝实质持平，到低于周围肝实质，最后造影剂完全退出瘤组织，在肝实质增强的背景下呈极低回声。肿瘤强化呈“快进快出”型。结论VX2瘤主要为肝动脉供血，具有恶性肿瘤“快进快出”典型的超声造影增强特点；低机械指数灰阶超声造影能完全反映肝恶性肿瘤血流动力学变化；观察肿瘤的动脉期是超声造影的关键，对诊断及鉴别诊断具有重要意义。     

兔VX2微小肝癌超声造影的实验研究

目的采用声学造影剂经外周静脉超声造影,研究最大径＜5.0 mm的兔肝VX2微小肝癌在造影前后的检出率.方法10只荷VX2肝肿瘤的新西兰白兔经外周静脉注射长效声学造影剂"脂氟显",二次谐波显像扫描记录肝脏造影影像,最后与动物肝大体病理切面对照,评价超声造影对微小肿瘤检出的敏感性.结果10只动物肝脏大体病理检查共检出31个微小肿瘤,大小1.6～5.0 mm.其中3.0～5.0 mm的肿瘤结节造影前检出3个,造影后检出8个;1.0～3.0 mm的肿瘤结节造影前检出1个,造影后检出17个.微小肿瘤检出敏感性从造影前的12.9%提高到造影后80.6%.结论声学造影增强显著提高了5.0 mm以下微小肝癌的检出率.     

兔肝VX2肿瘤超声造影时相划分:与多排螺旋CT增强扫描对照实验研究

目的 探讨灰阶实时超声造影(CEUS)和多排螺旋CT(MDCT)增强扫描兔肝VX2肿瘤的增强显像特征及兔肝超声造影时相的划分标准.方法 运用超声造影剂SonoVue对33只荷肝VX2瘤兔行CEUS和64排螺旋CT增强扫描,以团注造影剂后肝动脉开始增强作为动脉期的起始时间,以VX2肿瘤增强达峰时间作为门脉期的起始时间,以肝实质增强达峰值强度时间作为实质期的起始时间,观察其增强特征,比较CEUS中肿瘤和瘤周同水平肝实质的时间强度曲线和MDCT中腹主动脉、门静脉、肝实质和肿瘤的时间密度曲线形态特征,制定划分各期时相的标准.结果 CEUS和MDCT对VX2肿瘤动脉期、门脉期、实质期起始时间的划定分别为(6.82±1.36)s、(11.64±2.03)s、(20.24±4.17)s和(9.43±2.23)s、(13.77±2.01)s、(22.71±4.58)s,CEUS较MDCT各相起始时间均提早(P<0.01),二者对兔肝VX2肿瘤增强显像特征一致,均表现为"快进快退".结论 CEUS可以对兔肝VX2肿瘤的灌注情况进行实时高分辨率显像,CEUS和MDCT时相标准可为相关的影像学评估研究提供基本的理论依据.     

A Km mutant of arylsulfatase A

Semi-micro techniques are presented for the genotyping of galactokinase and galactose-1-phosphate uridyltransferase. Radioactive assays are used to quantitate the levels of enzyme activity, while agarose gel electrophoresis is used to type the variants of galactose-1-phosphate uridyltransferase. All three methods can be performed on 1 ml whole blood, making the procedures ideal for use in confirmation of galactosemia or galactokinase deficiency in newborn screening programs.     

Hepatitis A: A preventable threat

Hepatitis A is a major public health problem, particularly in the pediatric population. Although hepatitis A infection does not cause chronic liver disease, it is associated with significant morbidity. The virus is transmitted primarily by person-to-person contact via the fecal-oral route. The infection can be inapparent, subclinical, anicteric, or icteric. In general, the severity of the disease is inversely correlated with the age of the child. Occasionally, fulminant hepatitis, which is associated with a high mortality rate, may result. The diagnosis of acute hepatitis A is most commonly made through the detection of immunoglobulin M (IgM) anti-hepatitis A antibody. Treatment is generally supportive. General preventive measures include improved standards of hygiene and sanitation. Universal childhood vaccination is the most effective method for eradicating hepatitis A and preventing its transmission.     

RHD845A/1227A基因型个体家系调查分析

本研究对1例RHD845A/1227A基因型个体进行家系调查分析,并分析他们的遗传特性。通过盐水法和间接抗人球蛋白试验（IAT）检测RH（D）抗原,PCR—SSP法检测RHD1227A和RHD845A等位基因以及RHD合子型,基因测序方式分析RIHD基因编码区序列。研究结果表明：血清学检测发现1例RH（D）抗原盐水法检测阴性、IAT法检测阳性样本,经RHD基因编码序列分析发现,RHD第845位与第1227位均出现G／A碱基杂合现象,推测该个体基因型可能为RHD845A／1227A。家系调查显示,先证者父亲为RHD阴性,母亲为RHD阳性。PCR-SSP检测结果显示,父亲携带RHDl227A等位基因,基因型为RHD845A／RHD-;母亲携带RHD845A等位基因,基因型为RHD845A／RHD＋,证明先证者分别从父亲和母亲遗传RHD1227A和RHD845A等位基因,基因型为RHD845A／1227A。结论：经过家系调查分析发现了1例罕见的RHD845A／1227A基因型个体。根据家系调查证明,RHD845A和RHD1227A等位基因分别由遗传获得,而非由个体基因变异形成。     

Potential Therapeutic Applications of Adenosine A2A Receptor Ligands and Opportunities for A2A Receptor Imaging

Adenosine A_2A receptors (A_2ARs) are highly expressed in the human striatum, and at lower densities in the cerebral cortex, the hippocampus, and cells of the immune system. Antagonists of these receptors are potentially useful for the treatment of motor fluctuations, epilepsy, postischemic brain damage, or cognitive impairment, and for the control of an immune checkpoint during immunotherapy of cancer. A_2AR agonists may suppress transplant rejection and graft‐versus‐host disease; be used to treat inflammatory disorders such as asthma, inflammatory bowel disease, and rheumatoid arthritis; be locally applied to promote wound healing and be employed in a strategy for transient opening of the blood–brain barrier (BBB) so that therapeutic drugs and monoclonal antibodies can enter the brain. Increasing A_2AR signaling in adipose tissue is also a potential strategy to combat obesity. Several radioligands for positron emission tomography (PET) imaging of A_2ARs have been developed in recent years. This review article presents a critical overview of the potential therapeutic applications of A_2AR ligands, the use of A_2AR imaging in drug development, and opportunities and limitations of PET imaging in future research.     

A PHYSIOLOGICO-PATHOLOGICAL STUDY OF A CASE OF HEART-BLOCK OCCURRING IN A DOG AS A RESULT OF NATURAL CAUSES

What is believed to be the first known case of heart-block arising in a dog as a result of an ingenerate pathological lesion is here reported. The auriculo-ventricular dissociation was of that degree known as relatively complete block and became apparent on section of the right vagus nerve. Stimulation of the peripheral end of the cut vagus failed to inhibit the ventricles, although complete inhibition of the auricles occurred. The same results were obtained during the ventricular acceleration produced by strophanthin, so that the failure of the vagus to inhibit the ventricles is not due to the latter''s infrequent action, but more probably to a normal lack of direct chronotropic influence upon the ventricular muscle. These findings are similar to those obtained by Erlanger in experimental heart-block. To small repeated doses of strophanthin injected intravenously the heart reacted as follows: (a) irregular slowing of the auricles and conversion of the relatively complete into an absolutely complete a-v block; (b) a rise in the irritability of the cardiac muscle manifested by a rapidly progressing auricular and ventricular frequency, the ventricular frequency surpassing ultimately the auricular frequency; (c) complete arrest of the auricles, the ventricles continuing at their high rate; (d) sudden fibrillation of the ventricles and shortly afterwards arrest in diastole. There were found post mortem myxomatous-like thickenings at the free edge of the septal tricuspid leaflet and at the attached margin of the posterior aortic leaflet and along part of the right anterior aortic leaflet. There was also a grayish patch on the right side of the auricular septum above the auriculo-ventricular junction. The thickenings at the edge of the valves consisted of dense, circumscribed masses of what appeared to be new connective tissue. The same tissue was found pressing against the bundle along the greater part of the latter''s course. There was considerable fatty infiltration of the auricular musculature immediately above the bundle and, to a slight extent, of the bundle itself. The fibers of communication between the auricular muscle and the node of Tawara were relatively few as compared with those of the normal heart. A review of the pathology of heart-block is appended, showing the present status of the question, concerning the relationship existing between disease of the a-v conducting system and the various grades of heart-block.