大鼠颈部异位心脏移植模型的建立与超声心动图观察

目的:探讨高频超声心动图观察大鼠颈部异位心脏移植模型的可行性及观察方法。方法:23例大鼠建立颈部异位心脏移植模型,其中同系移植6例,同种移植17例。术前对原位心脏行超声心动图观察,常规记录原位心左室长轴切面、乳头肌水平左室短轴切面、心底短轴切面及心尖四腔切面,测量舒张末期、收缩末期左室内径、舒张末期左室壁厚度、左室射血分数。术后立即对移植心脏行超声心动图观察,并显示上述切面,测量相应超声指标,所测指标与术前原位心比较。结果:23只实验鼠原位心可显示乳头肌水平短轴、心底短轴、左室长轴和心尖四腔切面各为19例、11例、10例和9例;异位移植心与原位心比较,移植心左室短轴内径明显减小;左室射血分数明显减低。结论:大鼠颈部异位心脏移植模型与原位心和腹腔异位移植心脏相比较乳头肌水平左室短轴切面是评价移植心脏形态、大小与心肌功能改变较为理想的切面。     

口服抗原对同种异体移植免疫反应的影响

将Wistar大鼠预先喂养同种异基因SD大鼠脾细胞7天，然后接受SD大鼠的皮肤移植，7天后，再接近SD大鼠的心脏移植，观察口服抗原后体外混合淋巴细胞培养（MLC）、体内迟发型超敏反应（DTH）以及心脏存活时间。口服抗原后，体外MLC及体内DTH反应均出现明显的抗原特异性降低，口服抗原组大鼠并接近供者皮肤致敏后的心脏移植存活时间达到7天，与对照组未致敏鼠的心脏移植存活时间一致；而未口服抗原组接受皮肤致敏后的心脏移植存活时间不超过2天。提示口服抗原可以使异基因抗原的特异性免疫应答降低，延长移植存活时间，阻皮肤移植物的事先致敏反应的发生，并使加速排斥反应时间明显延迟。     

MRI对同种心脏移植术后的评估

终末期心脏病的唯一治疗方法是心脏移植 ,器官保存和免疫制剂治疗使得术后存活率大为改善。对术后心脏的评估 ,包括评价心功能 ,检测排斥反应是临床进行及时治疗和处理的重要前提。一种有效的、能综合评估术后心脏的方法是临床所关注的焦点 ,笔者将近年来ＭＲＩ用于移植术后心脏评估的文献加以综述 ,以供临床参考。1　ＭＲＩ对移植心脏排斥反应的检测心脏排斥反应按时间划分为超急性排斥、加速性排斥、急性排斥和慢性排斥。后两者是影响心脏存活的最主要原因。急性排斥通常在术后几天至 2周出现。从组织学的角度评价急性排斥反应通常有以下…     

五例心脏移植术后的远期观察

目的：通过对5例原位心脏移植术后病人的远期观察，探讨心脏移植术后受者的远期存活情况。方法：通过冠脉造影、心动超声、心肌活检、心电、血生化、血常规、环孢素A浓度测定等方法观察病人冠脉病变情况，心功能状态，排斥反应程度。结果：5例心脏移植受者冠脉造影均正常，心动超声两例轻度瓣膜返流外，其余未见明显异常。心肌活检两例有轻度排诉反应。结论：正常合理的用药，心脏移植受者的存活状态是相当令人满意的，长期存活也是可以预期的。     

热休克蛋白70与大鼠小肠移植后急性排斥反应的实验研究

 目的 探讨热休克蛋白(HSP)70在大鼠小肠移植后急性期排斥反应中的作用.方法 建立SD大鼠到Wistar大鼠(异基因移植组)、Wistar大鼠到Wistar大鼠(同基因移植组)异体并列式小肠移植模型,应用免疫组织化学S-P法检测术后第1、4、7天肠标本HSP70表达,常规病理HE染色判定移植小肠的免疫排斥反应分级.结果 术后第7天,异基因移植组HSP70的表达高于同基因移植组;且HSP70的表达高者,小肠免疫排斥反应程度重.结论 HSP70与大鼠小肠移植后急性排斥反应有关,对急性排斥反应的早期诊断有参考价值.     

α-黑素细胞刺激素对同种异体小鼠异位心脏移植排斥反应的抑制作用

目的 观察小黑素细胞刺激素（α-MSH）对同种异基因小鼠移植心脏存活时间的影响,以了解其在移植免疫中的作用。方法 小鼠颈部心脏移植的Cuff模型,腹腔给予α-NSH,观察移植心脏的存活时间和病理改变。结果 移植小鼠给予α-NSH后,移植心脏的存活时间比对照组显著延长,心脏病理显著改善,其中以50μg组效果最佳。结论 α-MSH能抑制同种异基因小鼠的心脏移植排斥反应。     

超声心动图对左房室瓣球囊扩张术后左室心肌重量及心脏收缩功能变化的评价

目的　应用经胸超声心动图(UCG)评价皮穿刺左房室瓣球囊扩张术对风湿性左房室瓣狭窄患者的左室心肌重量和心脏收缩功能的影响。方法　使用美国Agilent公司生产的PhilipsSonos 5 5 0 0、75 0 0型彩色多普勒超声心动图仪检测4 0例风湿性左房室瓣狭窄患者成功行皮穿刺左房室瓣球囊扩张术后的左室心肌重量、左室收缩功能及左室内径大小的变化,分别于经皮穿刺左房室瓣球囊扩张术术后3d内和手术后3个月接受超声心动图检查。所有研究对象均进行经胸M型、二维及多普勒超声心动图检查,采用二维超声心动图根据面积-长度法测量左室心肌重量,并与体表面积换算成左室心肌重量指数;M型超声心动图测量左室舒张末期径以及根据Teichholz校正公式测量左室射血分数(EF)、左室短轴缩短率(FS)、每搏出量(SV)和心输出量(CO) ;二维及多普勒超声心动图分别按椭圆形面积公式及压差半降时间(pressurehalftime ,PHT)法测量左房室瓣口面积(MVA)。结果　(1)经皮穿刺左房室瓣球囊扩张术后3d全部患者的左室舒张末期径增大(P <0 .0 1) ;射血分数(EF)、左室短轴缩短率(FS)、每搏出量(SV)和心输出量(CO)均明显提高(P <0 .0 0 1) ;同时室间隔厚度、左室后壁厚度、左室心肌重量和左室心肌重量指数也有所改变(P <0 .0 5 ) ;(2 )术后3个月室间     

异种异体和同种异体半月板移植术后兔半月板和关节软骨中Ⅰ、Ⅱ、Ⅲ、Ⅹ型胶原表达和免疫排斥研究

目的 :研究同种异体半月板移植和异种异体半月板移植后 ,移植半月板和关节软骨中的Ⅰ、Ⅱ、Ⅲ、Ⅹ型胶原表达和免疫排斥反应发生的情况。方法 :切除 30只成年新西兰白兔的内侧半月板造成半月板缺失的动物模型。A组进行同种异体内侧半月板移植。B组取猪半月板组织修剪成同兔内侧半月板形态和尺寸相同的异种异体半月板植入物 ,进行兔内侧半月板的异种异体移植。分别在术后第 6周、12周、2 4周取实验动物的半月板、关节软骨进行Ⅰ、Ⅱ、Ⅲ、Ⅹ型胶原的单克隆抗体的免疫组织化学染色 ,并取外周血进行补体依赖性微量淋巴细胞毒实验 (CDMT) ,用放射免疫法检测血清中IL - 2和IL - 6的含量 ,了解是否发生免疫排斥反应。结果 :同种异体半月板移植后 ,关节软骨和移植半月板的情况良好 ,但术后第 2 4周 ,异种异体移植物部分被吸收 ,关节软骨出现损伤。两组中各时段移植半月板中的Ⅰ、Ⅱ和Ⅲ型胶原的表达情况无明显差异 ,术后第 12周 ,两组关节软骨中Ⅰ、Ⅱ和Ⅲ型胶原的表达情况相似 ,但术后第 2 4周 ,异种异体半月板组的关节软骨开始有异常Ⅹ型胶原表达。同种异体和异种异体半月板移植组均未发现致命的免疫排斥反应发生。结论 :用猪的半月板组织塑形后移植替代兔内侧半月板组织 ,半年后移植物被溶解吸收 ,同种异体?     

大鼠同种异体膀胱移植的实验研究

目的 建立大鼠无血管吻合膀胱移植的实验模型,观察膀胱移植的效果.方法 20只Sprague-Dawley(SD)幼大鼠作为供体,切取膀胱后,分别将其无血管吻合移植至20只5周龄Wistar大鼠大网膜上,同时予以免疫抑制治疗,分别于术后7、14天各处死10只大鼠,切取移植膀胱标本观察存活情况并作定量指标检测.结果 在20只膀胱移植大鼠中有19只大鼠及移植膀胱存活成功,移植膀胱无明显排斥反应,镜检示膀胱存活良好,膀胱壁内血管、上皮和肌肉层的形态正常.结论 大鼠同种异体无血管吻合膀胱移植存活率较以往明显提高,是一种比较稳定的移植模型.     

冷冻同种异体肌腱小鼠移植的细胞毒、IL－2水平及组织学观察

了解冷冻同种异体肌腱移植术后宿主的免疫排斥反应。方法采用ＢＡＬＢ／Ｃ小鼠肌袋模型，植入冷冻Ｃ５７小鼠跟腱，观察术后各期宿主血清微量细胞毒性，局部组织浆ＩＬ－２水平和局部组织学变化。结论经冷冻／冻干处理后，同种异体肌腱移植免疫斥反应显著降低，但未消失。     

The detection of cardiac allograft rejection by alterations in proton NMR relaxation times

The ability of proton NMR relaxation times to detect cardiac allograft rejection was studied in an inbred rat heterotopic cardiac transplantation model. Hearts from 25 Lewis X Brown Norway F1 hybrid rats were anastomosed to the abdominal aorta and vena cava of Lewis recipients; 25 Lewis donor hearts served as isograft controls. Groups of five allografts and five isografts were harvested daily between two and six days post-transplant. The relaxation times T1 and T2 of the transplanted hearts were determined in vitro with a 10 MHz spectrometer. T1 and T2 values in allografts did not differ significantly from those in isografts at days 2 and 3 post-transplant. However, at days 4, 5, and 6 T1 and T2 of the allografts were significantly prolonged. This finding correlated with an elevation in tissue water content and the onset of rejection as determined histologically. An additional 21 allografts, treated with cyclosporine, were studied in the same way from four to more than 100 days post-transplant. T1 and T2 values of these treated allografts did not change significantly during the observation period and were similar to the relaxation values obtained in the isografts at days 2 to 6. These data suggest that serial measurements of myocardial T1 and T2 may be useful in detecting acute cardiac allograft rejection and monitoring the effect of antirejection treatment.     

A comparison of MRI and echocardiography in hypertrophic cardiomyopathy.

This study compares MRI and echocardiography as imaging modalities in hypertrophic cardiomyopathy, with particular reference to measurement of left ventricular wall thickness and mass. 10 subjects underwent echocardiography and MRI. Contiguous 10 mm short axis 35 degrees flip angle cine gradient recalled echo MR images were acquired from the apex to the base of the left ventricle at 1.5 tesla. Standard M-mode and cross-sectional echocardiographic views of the left ventricle were obtained. Excellent agreement between measurements occurred with MRI and M-mode echocardiographic assessment of the thickness of the anterior interventricular septum (95% limits of agreement -1.5 to +1.5 mm). Other comparisons of MRI vs M-mode echocardiographic measurements had the following limits of agreement: posterior free wall -3.3 to +2.9 mm; end-diastolic dimension -5 to +8 mm, left ventricular mass -291 to +55.5 g. Comparing MRI with cross-sectional echocardiographic measurements, the limits of agreement were: anterior interventricular septum -2.4 to +1.7 mm, posterior interventricular septum -2.4 to +2.9 mm, posterior free wall -3.4 to +2.5 mm, anterior free wall -2.4 to +1.7 mm, end-diastolic dimension -4.1 to +8 mm. MRI estimates of LVM in systole vs diastole showed good agreement with 95% limits of agreement of -20 to +17 g, with excellent interobserver variability in diastole (-9 to +5 g) and in systole (-7 to +12 g). In conclusion, MRI is superior to echocardiography for the quantification of ventricular mass in the abnormal left ventricle because it does not make invalid geometrical assumptions. Comparisons of wall thickness show greater discrepancy with increasing distance from the echocardiographic transducer. This study suggests that sequential echocardiography could rationalize the need for MRI in left ventricular hypertrophy. A change in anterior septal thickness of > or = 3 mm on echocardiography merits a further MRI study.     

MRI of the cardiomyopathies

We examined the potentialities of Magnetic resonance imaging (MRI) in the evaluation of the main cardiomyopathies: hypertrophic, dilated, restrictive and arrhythmogenic right ventricular. The hypertrophic cardiomyopathy is generally adequately investigated by echocardiography, that well defines the myocardial thickening and the obstruction of the left ventricular output. However, by echocardiography we still have difficulties in the evaluation of the apex of the left ventricle and the right ventricle involvement. MRI provides a complete evaluation of the heart with a clear evidence also of the echocardiographic dark zones by means of a clear evidence of the apex of the right ventricle. The dilated form is also well investigated by MRI that provides a clear evaluation of the volumes, mass and ejection fraction by means of the 3D analysis including conditions of the ventricular remodelling. Moreover, this technique helps in the differential diagnosis of acute myocarditis. In the acute phase of myocarditis (first 2 weeks), in fact, the myocardium produces high signal intensity on the T2 weighted sequences due to the presence of oedema. The third form of cardiomyopathy is the restrictive one, characterised by reduced diastolic filling and diastolic volume, normality of the systolic function and parietal thickness, interstitial fibrosis and enlargement of both atria. The mean potentiality of MRI is related to the differential diagnosis with constrictive pericarditis. Only in the former, the pericardium appears irregularly thickened with areas exceeding 4 mm of pericardial thickness. Finally, the right ventricular arrhythmogenic cardiomyopathy represents the main indication to MRI evaluation. With this imaging modality we are can obtain a clear morpho-functional evaluation of the right ventricle and distinguish the intramyocardial adipose substitution characterised by areas of high signal in the myocardium.     

超声心动图检测模拟失重大鼠左心室的结构与功能

目的验证模拟失重４ｗｋ大鼠心脏工室的结构与功能 否出现类似航天员飞行后的变化,方法 应用超声心动图技术检测模拟失重大鼠心脏左室的结构与功能。结果 模拟失重４ｗｋ大鼠左室舒张末与收缩末短径显著减小;左室壁厚度亦减小,但差别未达显著程度。左室舒张末与收缩末容积,每搏量及其相应的体重归一化指数皆显著减少,左室估计质量及其指料显著减少。     

Increased left ventricular mass in a bodybuilder using anabolic steroids.

As the effects of anabolic steroids on left ventricular structure and function are unknown, we carried out clinical examination, 12 lead electrocardiography and echocardiography on a 23 year old male bodybuilder using these drugs. In this subject we found values of ECG voltage criteria, left ventricular-mass, posterior wall and interventricular septal thickness which exceeded those found in normal subjects and also in other competitive, power athletes. Despite these values, however, ejection fraction remained normal. This would suggest that anabolic steroids perhaps have a direct effect on the myocardium, in addition to the effects of training, but whether this is of pathological significance is unclear.     

Ventricular function during the acute rejection of heterotopic transplanted heart: Gated blood-pool studies

Twenty patients who had undergone a heterotopic heart transplant were studied prospectively to determine the relationship between rejection and ventricular dysfunction assessed from gated blood-pool studies. A fully automated method for detecting ventricular edges was implemented; its success rate for the grafted left and right ventricles was 94% and 77%, respectively. The parameters, peak ejection and filling rates, were calculated pixel per pixel using a two-harmonic Fourier algorithm and then averaged over the ventricular region of interest. Peak filling and ejection rates were closely related with the severity of the rejection, while the left ventricular ejection fraction was not. Peak filling rates of both ventricles were the indices closely related to the presence of moderate rejection. Despite the low number of patients, these data suggested that gated blood-pool-derived indices of ventricular function are associated with ventricular dysfunction resulting from myocarditis rejection. Radionuclide ventriculography provides parametric data which are accurate and reliable for the diagnosis of rejection.     

Ventricular function during the acute rejection of heterotopic transplanted heart: gated blood-pool studies.

Twenty patients who had undergone a heterotopic heart transplant were studied prospectively to determine the relationship between rejection and ventricular dysfunction assessed from gated blood-pool studies. A fully automated method for detecting ventricular edges was implemented; its success rate for the grafted left and right ventricles was 94% and 77%, respectively. The parameters, peak ejection and filling rates, were calculated pixel per pixel using a two-harmonic Fourier algorithm and then averaged over the ventricular region of interest. Peak filling and ejection rates were closely related with the severity of the rejection, while the left ventricular ejection fraction was not. Peak filling rates of both ventricles were the indices closely related to the presence of moderate rejection. Despite the low number of patients, these data suggested that gated blood-pool-derived indices of ventricular function are associated with ventricular dysfunction resulting from myocarditis rejection. Radionuclide ventriculography provides parametric data which are accurate and reliable for the diagnosis of rejection.     

The clinical utility of radionuclide ventriculography in cardiac transplantation

To assess ventricular function in patients who have undergone cardiac transplantation, 247 radionuclide ventriculograms were performed on 94 patients. During the first three days after transplantation, 19% demonstrated left ventricular dysfunction and 41% showed isolated right ventricular dysfunction. In 95 cases, radionuclide ventriculography was performed within 24 hr of myocardial biopsy. A reduction in left ventricular ejection fraction to less than 50% was significantly more common with moderate-severe rejection than with mild rejection. In six instances in which there was discordance between ventriculography and biopsy, radionuclide ventriculography proved particularly useful: three cases showed severe left ventricular dysfunction despite only mild rejection by biopsy, and three cases with ventricular dysfunction from rejection were missed by the initial biopsy. Thus, radionuclide ventriculography can provide functional data in transplant patients that is complementary to myocardial biopsies since biopsy grade is a poor predictor of left ventricular function and biopsy can miss significant rejection.     

Early predictors of left ventricular function improvement late after myocardial infarction

BACKGROUND/AIM: Prognosis after acute myocardial infarction (AIM) depends on the extent of irreversibly damaged myocardium and viable tissue due to stunning or hibernation. The aim of the study was to assess the prognostic significance of early echocardiographic parameters of myocardial viability in prediction of late recovery of regional and global ventricular function. METHODS: The study prospectively included 40 patients after the first, uncomplicated univessel AIM treated with percutaneous coronary intervention (PCI). Low dose dobutamine echocardiography (LDDE) was preformed 7-10 days after AIM and follow-up resting echocardiography from 7 to 12 months later. RESULTS: The sensitivity and specificity for the prediction of post revascularisation regional, dys synergy improvement were 61.29% and 94.59% respectively. The positive and negative predicative values were 90.48% and 74.47% re spectively. The number of viable segments (p = 0.01) and extent of contractile reserve (p = 0.01) were univariate, independent predictors of improvement in ejection fraction (EF). From the multivariate stepwise regression analysis contractile reserve was selected as most powerful predictor of late recovery of left ventricular contractile function (p = 0.007). Receiving-operator characteristic curve (ROC) analysis demonstrated that three or more recovered segments were necessary for an improvement of left ventricular ejection fraction (LVEF) > or = 5% after the revascularisation, with the highest sensitivity, 100% and specificity 56% (p = 0.01). CONCLUSION: Low-dose dobutamine echocardiography is a powerful predictor of the regional dys synergy recovery late after AIM treated with PTCA with implantation stent. Late full functional improvement of the left ventricle is related to the extent of contractile reserve and amount of viable tissue. At least three recovered segments are necessary for a significant recovery of the global left ventricular contractility.