重组葡激酶动静脉溶栓治疗犬急性脑梗死的研究

目的探讨重组葡激酶（r—Sak）溶栓的安全性、有效性以及溶栓的时间窗。方法成年比格犬24条，数字表法随机等分为对照组、r—Sak 6h动脉溶栓组和3h静脉溶栓组。用介入技术建立犬急性脑梗死模型，溶栓前行脑血管造影，分别经动脉和静脉进行治疗（对照组和6h动脉溶栓组：分别在栓塞后6h经颈内动脉注入生理盐水10ml和r—Sak0．2mg／kg＋生理盐水10ml；3h静脉溶栓组：栓塞后3h经静脉注入r—Sak0．2mg／kg＋生理盐水10m1），在溶栓后30、60及120min分别行脑血管造影复查，并在溶栓前30min，溶栓后30、60及120min抽取犬静脉血检测血浆凝血酶原时间（PT）、活化的部分凝血活酶时间（APTT）和D-二聚体。栓塞后24h处死动物行病理检查。结果溶栓后6h动脉溶栓组、3h静脉溶栓组和对照组有效的血管数分别为11支（11／13）、8支（8／11）和1支（1／10），差异有统计学意义（P〈0．01）；其中完全通畅的血管分别是6支（6／13）、2支（2／11）和0支（0／10），差异有统计学意义（P〈0．05），但6h动脉溶栓组和3h静脉溶栓组间有效和完全再通的血管数比较差异均无统计学意义（P=0．630和0．211）。溶栓后PT、APTT在r-Sak溶栓组均显著延长，各组的D-二聚体在溶栓前后无明显变化（P值均〉0．05）。24h后动物均存活，6h动脉和3h静脉溶栓组临床症状较轻，病理检查未发现脑出血并发症。结论r-Sak动脉内6h溶栓治疗安全有效，早期血管再通效果较好。     

First results in an MR imaging--compatible canine model of acute stroke

BACKGROUND AND PURPOSE: The purpose of this work was to develop an MR imaging-compatible animal model of reversible embolic stroke. We hypothesize that real-time MR imaging of the brain can be performed during stroke thrombolysis and can provide real-time feedback and guidance on the success of thrombolysis. METHODS: Embolic strokes were induced in 5 adult dogs by the use of autologous blood clots, with a sixth dog serving as an experimental control. Serial MR anatomic and physiologic imaging was performed to track the evolution of the stroke. The apparent diffusion coefficient (ADC) and quantitative cerebral blood flow (qCBF) were compared in the normal and stroke regions. During and after the administration of a chemical thrombolytic agent, MR imaging was performed to assess the outcome of the treatment. RESULTS: Strokes were successfully created in 5 animals. No ADC or qCBF changes were observed in the control animal. Both ADC and qCBF values were found to be significantly different in the region affected by the stroke. Restoration of flow was observed in 1 case. CONCLUSION: We have successfully implemented an MR imaging-compatible canine model of reversible embolic stroke.     

Evaluation of critically perfused area in acute ischemic stroke for therapeutic reperfusion: A clinical PET study

To evaluate critically perfused areas in the acute ischemic brain, 9 patients were studied by positron emission tomography (PET) within 7–32 hours after the onset. The cerebral blood flow (CBF) and oxygen metabolic rate (CMRO₂) were evaluated and compared with sequential change in CT findings. In all the regions developing subsequent necrosis on CT, CBF dropped below 17 ml/100 g/min. But in some of these lesions, CMRO₂ remained above the minimum value for regions in which infarction did not develop, and the tissue density on CT obviously remained normal for several hours after PET scan. The mean CBF in these lesions (14.0 ml/100 g/min, range: 9.9–17.3 ml/100 g/min) was significantly higher than that in ischemic areas with low density on CT before or just after PET study (～10 ml/100 g/min, range: 7.7–14.1 ml/100 g/min). These findings suggest that a part of the tissue with CBF between 10–17 ml/100 g/min is still viable at least 7 hours after the onset of ischemia, but becomes non-viable in a longer period of ischemia. These lesions should respond to effective treatment, including therapeutic reperfusion.     

不同时间窗急性缺血性卒中在FLAIR、DWI序列上的信号变化

目的：探讨急性缺血性卒中在FLAIR、DWI序列上病灶信号强度随时间变化的过程。方法：收集发病时间≤48 h的急性缺血性卒中240例,根据发病时间,分为6组,≤4.5 h组（19例）、>4.5～6 h组（24例）、>6～12 h组（55例）,>12～24 h组（43例）,>24～36 h组（53例）,>36～48 h组（46例）。分别测量FLAIR、DWI序列病变侧、健侧信号强度值及ADC值,计算病变侧/健侧信号强度比值（RSI）及相对ADC值,并进行统计学分析。结果：①FLAIR序列各组RSI值间差异具有统计学意义（P<0.05）。48 h内,随着卒中时间的延长,FLAIR序列的RSI呈上升趋势。②DWI序列各组RSI值差异无统计学意义（P>0.05）,各组相对ADC值差异无统计学意义（P>0.05）。在48 h内,DWI的信号强度及相对ADC值未出现上升或下降趋势。结论：急性缺血性卒中FLAIR序列的病灶信号强度随发病时间的延长而增加;DWI的RSI及相对ADC值随时间变化未出现上升或下降趋势。     

急性缺血性脑卒中支架取栓首次成功再灌注的影响因素分析

目的 探讨前循环急性缺血性脑卒中(AIS)患者支架取栓术首次成功再灌注(FPR)的影响因素.方法 回顾性分析2018年1月至2020年3月在南京医科大学第一附属医院接受Solitaire AB支架取栓治疗的前循环AIS患者临床资料.根据首次支架取栓后闭塞血管再通程度是否达到改良溶栓治疗脑梗死(mTICI)血流分级2c/...     

High signal intensity lesions of the chest in MR imaging

The majority of pathologic lesions in the lung and mediastinum have relatively long T1 and T2 relaxation times and consequently yield medium to low signal intensity on T1-weighted images. Pulmonary lesions with high signal intensity on T1-weighted images are unusual and raise a special group of diagnostic considerations. In the current study, a mass with a lesion/fat signal intensity ratio of greater than 0.7 on a T1-weighted sequence was considered high signal intensity. The nature of these masses was ganglioneuroma or ganglioneuroblastoma (n = 3), atrial lipoma (lipomatous atrophy of the interatrial septum) (n = 3), pheochromocytoma (n = 2), bronchogenic cyst (n = 2), lymphangioma (n = 1), teratoma (n = 1), and a variety of primary and metastatic tumors of the mediastinum and lung. A single pathologic structure of these lesions was not present, but rather several underlying tissue compositions were noted, including fat, subacute hemorrhage, myxoid material, and cellular composition with high cytoplasmic/nuclear ratio. Thus, high signal intensity lesions of the thorax on T1-weighted images should suggest a number of differential diagnoses.     

替罗非班在急性颅内大血管闭塞血管内治疗中应用的安全性分析

目的探讨颅内大血管闭塞性缺血性脑卒中行血管内再通治疗术中合并使用替罗非班对颅内出血的影响。 方法回顾性分析本中心接受血管内再通治疗的急性颅内大血管闭塞性缺血性卒中患者的临床资料,比较术中使用替罗非班与未使用替罗非班两组患者的一般临床特点、治疗方式以及颅内出血并发症等差异。 结果共计纳入173例患者接受血管内再通治疗,其中替罗非班组87例,非替罗非班组86例,替罗非班组中后循环（39.08% vs 25.58%,P=0.034）、糖尿病（24.14% vs 10.47%,P=0.026）比例显著高于非替罗非班组,非替罗非班组中房颤患者比例显著高于替罗非班组（P<0.001）,两组患者手术再通率及随访90 d预后良好比例相当,围手术期颅内出血并发症未见差异。 结论血管内再通治疗合并使用替罗非班是相对安全的,并未增加出血风险。     

The determination of myocardial viability using Gd-DTPA in a canine model of acute myocardial ischemia and reperfusion

The partition coefficient of Gd-DTPA was thought to vary with the amount of cellular membrane damage after an acute myocardial infarction. The relationship between the partition coefficient of Gd-DTPA (λ) and the uptake of ²⁰¹TI (as a marker of tissue viability) was studied 2 h to 3 weeks after reperfusion of a 2-h occlusion to the left anterior descending coronary artery in a canine model. Gd-DTPA was infused as a bolus followed by a prolonged constant infusion, and this infusion protocol was optimized such that the concentration of Gd-DTPA was directly related to λ. After this infusion, MR images of excised hearts showed regions of increased signal intensity corresponding to increased Gd-DTPA concentration. At all time points, λ and ²⁰¹TI uptake were strongly negatively correlated indicating that λ is an accurate indicator of myocardial viability. Furthermore, λ in the infarcted regions was increased relative to normal regions after 2 h of reperfusion and stayed elevated up to 3 weeks. At all time points, λ in the infarcted and normal regions were significantly different. As well, this data showed a trend that λ in infarcted regions decreased monotonically from 1 day to 3 weeks. This trend was confirmed with MR imaging by examining the change in signal intensity of in vivo images from 4 days to 3 weeks in two animals. These results suggest that MRI with Gd-DTPA could be used to measure the extent of myocardial damage after an acute myocardial infarction.     

急性缺血性卒中常规磁共振成像血管内高信号的特点与意义

目的探讨急性缺血性卒中常规磁共振成像血管内高信号的特点及其对早期诊断的临床意义。方法回顾性分析368例急性缺血性卒中患者的影像学资料,观察血管内高信号与血管病变的关系。结果急性缺血性卒中常规磁共振成像血管内高信号的检出率为8．60％,多见于颈内动脉、椎动脉、基底动脉等。常规磁共振成像血管内高信号对前循环动脉病变检出的特异度为100％,敏感度为68．75％;对后循环动脉病变检出的特异度为100％,敏感度为64．71％。结论T1WI和T2WI序列对于急性缺血性卒中血管内高信号的展示具有很高的临床特异度,类似于MRA检查。对于超急性期缺血性卒中磁共振常规序列时的血管内高信号,应予以重视,早期予以介入等治疗。     

Protective effect of agmatine on a reperfusion model after transient cerebral ischemia: Temporal evolution on perfusion MR imaging and histopathologic findings

BACKGROUND AND PURPOSE: The goal of thrombolytic therapy in patients with acute ischemic stroke is early recanalization, but this may result in delayed reperfusion injury. The purpose of this study was to evaluate the neuroprotective effect of agmatine in a transient ischemic cat model by using MR perfusion imaging and histopathologic analyses. METHOD: One-hour temporary occlusion of the left middle cerebral artery of cats was performed in the control ischemia group (n = 10), and 100 mg/kg of agmatine was intravenously injected immediately after recanalization in the agmatine-treated group (n = 15). MR imaging was performed at 1, 24, and 48 hours after recanalization, and the perfusion patterns were investigated. Terminal-deoxynucleotidyl transferase mediated nick and end-labeling (TUNEL) and hematoxylin-eosin (H&E) stainings were performed at the corresponding sections. RESULTS: In the control ischemia group, the number of TUNEL-positive cells was significantly increased in the areas with reperfusion hyperemia (P < .05). In the agmatine-treated group, no significant increase in the number of TUNEL-positive cells was noted in the areas of reperfusion hyperemia. The difference in the number of TUNEL-positive cells between the control ischemia and agmatine-treated group in the areas of reperfusion hyperemia was significant (P < .05). The total number of TUNEL-positive cells and the area of severe ischemic neuronal damage on H&E stain were also significantly attenuated in the agmatine-treated cats compared with the control ischemia cats (P < .05). CONCLUSION: Our results suggest that agmatine has neuroprotective effects against reperfusion injury and ischemia.     

MR-tutor: a program for teaching the interdependence of factors which influence signal intensity in magnetic resonance imaging

Magnetic resonance (MR) imaging is a valuable diagnostic radiologic procedure. The appearance of tissues on the MR scan is dependent upon a complex relationship among a number of variables. We have written a computer program which teaches students of magnetic resonance imaging the interdependence of these variables and how they affect the appearance of tissues on MR images. The program is written in BASIC for the IBM* and compatible computers. A listing of the program appears in the Appendix of this article.     

Tissue hyperplasia: influence of a paclitaxel-eluting covered stent--preliminary study in a canine urethral model

PURPOSE: To evaluate a paclitaxel-eluting covered stent in reduction of tissue hyperplasia after stent placement in a canine urethral model. MATERIALS AND METHODS: Procedures were performed in accordance with the National Institutes of Health guidelines for humane handling of animals; approval of the committee of animal research was obtained. Twenty paclitaxel-eluting polyurethane-covered stents (drug stents) and 20 polyurethane-covered stents (control stents) were placed alternately between the proximal and distal urethra in 20 male dogs. The dose of paclitaxel was approximately 1800 mug in each drug stent but absent in each control stent. Dogs were sacrificed either 4 (n = 10) or 8 (n = 10) weeks after stent placement. The percentage diameter of stenosis was assessed with follow-up retrograde urethrography and histologic findings obtained after sacrifice and compared between drug stents and control stents and between the proximal and the distal urethra. RESULTS: Two drug stents partially migrated during retrograde urethrography immediately after stent placement; they were removed and replaced with a second stent during the same procedure. There was a strong tendency toward a lower percentage diameter of stenosis and numeric mean values of the four histologic findings, which indicates less formation of tissue hyperplasia in the proximal urethra than in the distal urethra. In particular, thickness of the papillary projection denoting the entire thickness of hyperplastic reaction was significantly less in drug stents than in control stents in the proximal urethra in the 8-week group (P = .016, Mann-Whitney U test). CONCLUSION: Local delivery of paclitaxel via covered stents has the potential to reduce tissue hyperplasia secondary to stent placement in a canine urethral model. With stent placement, there are distinct differences of tissue hyperplasia between the proximal and distal urethra.     

急性颈内动脉系统脑梗死的局部动脉溶栓治疗

目的　检验局部注射尿激酶动脉溶栓治疗急性颈内动脉系统脑梗死的安全性和疗效。方法　分析 5 4例接受局部动脉溶栓治疗的颈内动脉系统急性脑梗死患者 ,其中颈内动脉主干闭塞 3例(5 .6 %) ,大脑中动脉主干及分支闭塞 46例 (85 .2 %) ,大脑前动脉闭塞 5例 (9.2 %)。结果　预后好的患者共有 41例 (75 .9%) ,血管再通程度 >5 0 %39例 (72 .2 %) ,再通程度 <5 0 %的 15例 (2 7.8%)。颅内出血率为 2 0 .4%,病死率为 7.4%。结论　局部动脉溶栓是一种有效的治疗方法 ,可以提高血管再通率 ,改善脑梗死患者的预后。     

高压氧治疗急性缺血性脑卒中近期疗效的系统评价

 目的评价高压氧(HBO)治疗急性缺血性脑卒中的近期疗效及安全性.方法使用国际Cochrane协作网的系统评价方法对全世界关于HBO治疗急性缺血性脑卒中的随机/半随机对照试验进行系统评价.结果至2001年12月,共收集到国内外23个已完成的RCTs,其中18个(共包括2 040例患者)试验,符合本研究的纳入标准.早期病死率降低(0 vs11.11%;OR 0.12;95%CI0.02～0.90;P<0.05),提示用HBO每治疗9人可避免约1人早期死亡;HBO治疗的副作用明显高于对照组(2.82%vs0;OR 5.54;95%CI 2.09～14.68;P<0.01);HBO治疗期末神经功能缺损改善的人数显著增加(94.88%vs79.18%:OR4.37;95%CI 3.30～5.77;P<0.01).结论HBO治疗急性缺血性脑卒中是一种有前途的治疗方法,但由于存在发表偏倚及RCTs普遍质量较低尚不能对HBO的疗效作出明确的结论,潜在的疗效及安全性有待于更多的设计严格的RCTs予以进一步证实.