急性卒中缺血半暗带的CT灌注成像

CT灌注成像能准确和及时地提供卒中后脑组织血流动力学参数,并且与当前公认的脑血流动力学测量手段——氙-CT、功能磁共振成像和正电子发射体层摄影等测得的参数有很好的相关性。因此,CT灌注成像在判断卒中后缺血半暗带研究中的应用日益广泛。     

颈动脉内膜-中膜厚度与缺血性脑血管病

颈动脉内膜-中膜厚度（IMT）是指颈动脉血管内膜和中膜之间的垂直距离。IMT增厚是动脉粥样硬化的早期表现。与缺血性脑血管病密切相关。也与多种血管危险因素有关,被认为是反映全身动脉粥样硬化性疾病的良好指标。临床上可借助超声检测颈动脉IMT来反映动脉粥样硬化的发生、发展或消退,并提供临床防治动脉粥样硬化的依据和疗效判断标准。     

左心交感神经切除术对长QT综合征患者U波的调节作用

目的为进一步理解T波和U波的关系及U波在长QT综合征(LQTS)中的病理生理学意义。方法对11例LQTS患者行左心交感神经切除(LCSD)手术,评价其手术前后及跟踪期间ECG上U波和T波变化。结果术后QTc(校正的QT间期:从0.50±0.05s到0.47±0.03s,P=0.02)、QTp(从QRS波起始到T波顶点的时间间隔:0.37±0.07s到0.33±0.06s,P=0.041)和QTpc(校正的QTp:从0.37±0.07s到0.34±0.05s,P=0.006)均显著缩短。同时QU间期(从QRS波起始到U波结束)、QUc(校正的QU间期)、QUp(从QRS波起始到U波顶点的时间间隔)、QUpc(校正的QUp)却无显著改变。TpTe(同一导联上T波顶点到T波结束点的时间间隔)无显著变化,但TpTe-max(12导联中最早的T波顶点到最晚的T波结束点的时间间隔,代表跨壁复极离散度:0.21±0.09s到0.18±0.07s,P=0.02)显著降低。U波幅度、T波幅度及U/T幅度比值均无显著变化,但TpUp(T波顶点到U波顶点的时间间隔:0.16±0.06s到0.19±0.05s,P=0.041)显著增加。手术后2天内,多数患者U波更明显并叠加于T波之上形成T-U融合现象;但随后融合程度逐渐减轻。结论LQTS患者的U波与T波具有不同的起源机制,因此在诊断LQTS测量QT间期时不应包含U波。     

Metabolism of cholesteryl esters of very low density lipoproteins in the guinea pig.

Very low density lipoproteins from guinea pig plasma, endogenously labeled with 3H in both the esterified and free cholesterol moieties, were obtained from serum collected 20 hr after the intravenous injection of 3H-cholesterol into donor animals. When these lipoproteins were injected into recipient guinea pigs, the esterified 3H-cholesterol was rapidly cleared from the plasma; 24% was in the liver in 5 min and 54% in 15 min. A smaller fraction of the esterified cholesterol appeared in other plasma lipoprotein fractions, with 3H in the low density lipoproteins reaching a peak of 9%-18% of the injected esterified 3H-cholesterol between 30 and 60 min after the injection. The results indicate that most of the esterified cholesterol in very low density lipoproteins of guinea pig plasma is removed directly by the liver and a minor fraction is transferred to low density lipoproteins. The pattern of labeling of cholesteryl esters of high density lipoproteins in these experiments suggests that their low concentration in the guinea pig is accompanied by a rapid turnover rate.     

Comparison of S-T segment changes on exercise testing with angiographic findings in patients with prior myocardial infarction

Ninety-seven patients with a prior transmural myocardial infarction who underwent coronary angiography and treadmill stress testing were studied retrospectively to assess the reliability of the exercise electrocardiogram in detecting additional disease in patients with a prior infarction. In patients with a previous inferior wall infarction, the S-T response to the treadmill stress test had a high degree of sensitivity (87 percent) and specificity (90 percent) in detecting additional significant coronary artery disease. However, in patients with a previous anteroseptal wall Infarction, the S-T response had much less sensitivity (52 percent), but the degree of specificity remained high (90 percent). In this group a positive test suggested the presence of ischemia in the lateral or inferoposterior region of the myocardium, or both. A negative S-T response was of little value In distingulshing among groups of patients with single or multiple vessel coronary artery disease. The presence of an anterior ventricular aneurysm is most likely responsible for this low sensitivity rate because it generates an opposing force to the ischemic vector, thereby cancelling the S-T segment changes and producing a false negative treadmill stress test. The resting surface electrocardiogram proved useful in predicting a false negative exercise test. The presence of Q waves in the precordial leads extending to lead V₄ or beyond decreased the sensltivity rate of treadmill stress testing to 33 percent.     

Captopril (SQ 14,225) (d-3-mercapto-2-methylpropanoyl-l-proline): A novel orally active inhibitor of angiotensin-converting enzyme and antihypertensive agent

Relatively potent and specific in vitro and in vivo (oral or intravenous) inhibition of angiotensin-converting enzyme by a nonpeptidic compound, captopril (SQ 14,225; d-3-mercapto-2-methylpropanoyl-l-poline), was demonstrated in excised guinea pig ileum and in rats, rabbits, cats, dogs, and monkeys. The design of captopril was based on a hypothetical model of the active site of the enzyme. Captopril, in vitro or in vivo, was about ten times as potent as teprotide. Inhibition of angiotensin-converting enzyme was evaluated in vitro and in vivo by inhibition of the contractile or vasopressor activity of angiotensin I or by augmentation of the contractile or vasodepressor activity of bradykinin. Acute of subacute dosage with captopril moderately to markedly lowered the blood pressure of the renin-dependent aorticligated and the conscious two-kidney Goldblatt hypertensive rat; in the latter, the effect was intensified by concomitant dosage with a thiazide diuretic. Furthermore, the life-prolonging effects of captopril in renal hypertensive rats were augmented by a thiazide diuretic. In the two-kidney Goldblatt rat, acute captopril (p.o.) was about ten times as potent as teprotide (s.c.) in lowering blood pressure. Acute or subacute oral doses of captopril moderately reduced the blood pressure of the spontaneously hypertensive Wistar-Kyoto rat; chronic dosage almost normalized blood pressure. Captopril produced little or no hypotension in the saltreplete normotensive Wistar-Kyoto rat. Bilateral nephrectomy virtually abolished the hypotensive activity of captopril in the spontaneous hypertensive rat. The results suggest that captopril acts in large part by inhibiting the renin-angiotensin-aldosterone system to reduce elevated blood pressure, especially in renindependent models of hypertension; the roles of the kallikrein-kinin-prostaglandin systems and sodium balance remain to be elucidated. Captopril also lowers blood pressure in apparently non-renin-dependent types of hypertension by mechanisms that are as yet undefined.     

Ischemic colitis in rats

Left-sided ischemic colitis was induced in 44 inbred Male Fischer rats of the same age by a standardized devascularization procedure. Fifteen animals had nothing else done (Group I). Twentynine animals had feces evacuated from the left colon and received an enema just before the procedure; 14 had a sterile-water enema (Group II), and 15 had a 1 per cent hydrocortisone enema (Group III). At sacrifice, 72 hours after the surgical procedure, the mucosal surface grossly involved in ischemic changes was measured. The mean area of ischemic changes in Group I was significantly greater than that of either Group II or Group III (P<.05). The incidence of circumferential changes was highest in Group I and lowest in Group III; the difference between Group I and Group III was marginally significant (P=.06). Read at the meeting of the American Society of Colon and Rectal Surgeons, Colorado Springs, Colorado, June 7 to 11, 1981. Supported by the Veterans Administration.     

维拉帕米和Na+/H+通道阻滞剂对大鼠肝脏热缺血再灌注损伤的影响及其机制

[目的]研究维拉帕米(VP)和5-N-乙基-异丙基阿米洛利(EIPA)单独及联合作用对大鼠肝脏热缺血再灌注损伤保护作用及其机制.[方法]50只SD大鼠随机分成空白组(A组),缺血再灌注组(B组),EIPA 缺血再灌注组(C组),维拉帕米 缺血再灌注组(D组),EIPA VP 缺血再灌注组(E组),每组10只.缺血前10 min自尾静脉注入药物.制备95%肝脏缺血模型,缺血30 min,再灌注2 h后取静脉血、肝脏标本,比较各组之间的肝功能(ALT, AST),肝组织匀浆XOD活性,肝组织Ca2 浓度以及肝组织形态学变化.[结果]VP和EIPA组各项检测指标与缺血再灌注组比有显著性差异,联合用药组与单独用药组比较有显著性差异(P＜0.05).[结论]维拉帕米和EIPA预处理能减轻肝脏缺血再灌注损伤,联合用药有协同保护作用,效果更明显.     

2型糖尿病患者臂-踝脉搏波传导速度与视网膜病变的关系

目的:研究2型糖尿病患者臂-踝脉搏波传导速度(ba-PWV)与糖尿病视网膜病变患病风险的相关性。方法:收集我院内分泌代谢病科门诊的2型糖尿病患者1 000例,对其进行问卷调查、体格检查、生化检测、ba-PWV检测、眼底检查,并将ba-PWV按照三分位分组,分析ba-PWV水平与糖尿病视网膜病变的相关性。结果:①根据baPWV水平按照三分位分组,每组的糖尿病视网膜病变患病率分别为5.6%(18/319)、11.0%(35/319)、14.2%(45/319),组间趋势明显(趋势P=0.000 4)。②多元Logistic回归分析显示,糖尿病视网膜病变与糖化血红蛋白(HbA1c)、糖尿病病程、使用降糖药物治疗呈显著正相关,比值比(OR)分别为1.35、1.07和2.59(均P     

合并2型糖尿病的缺血性脑梗死复发危险因素研究

目的分析合并2型糖尿病的急性缺血性脑卒中患者首次发生脑梗死与复发脑梗死的临床特点。方法采用Logistic回归分析,回归模型以脑梗死为因变量,年龄、性别、高血压病、糖尿病、三酰甘油(TG)、胆固醇、低密度脂蛋白(LDL-C)、高密度脂蛋白、纤维蛋白原、血小板聚集率、尿酸、同型半胱氨酸、颈动脉斑块及吸烟为自变量,分析缺血性脑卒中的危险因素。回顾性分析合并2型糖尿病的缺血性脑卒中首次发生脑梗死100例患者的临床资料,与复发性脑梗死100例患者进行对比分析。结果年龄、糖尿病、LDL-C、颈动脉斑块及吸烟是缺血性脑梗死的独立危险因素。合并糖尿病的缺血性脑卒中首次脑梗组年龄63.26岁±9.93岁,入院时收缩压、舒张压均高于复发脑梗死组,收缩压结果有统计学意义(P<0.05);首次脑梗组胆固醇、TG、LDL-C均高于复发组(P<0.05);复发脑梗组年龄66.35岁±9.51岁,纤维蛋白原、血小板聚集率均高于首发组(P<0.05)。颈动脉斑块性质分析,两组均以硬斑为主,结果无统计学意义。首发组入院及出院时NHISS评分均低于复发组(P<0.05)。合并糖尿病的急性缺血性脑卒中首发组以部分前循环梗死(PICA)比例最多,而复发组以腔隙性脑梗死(LACI)比例最多,结果有统计学意义。结论合并2型糖尿病的缺血性卒中,首次脑梗死组收缩压高,血脂明显异常,而复发脑梗组血液黏度升高;首次脑梗组以部分前循环梗死为主,复发脑梗组以腔隙性脑梗死为主,呈多灶病变;复发脑梗组患者预后差,遗留神经功能缺损较明显,住院时间延长,卒中相关性痴呆发生率高。