ABSTRACT
BACKGROUND: Apoptosis, as opposed to necrosis, is a active and regulated mode of cell death. Persistent myocardial ischemia results in necrosis. The most effective method to limit ischemic myocardial injury is reperfusion, however, reperfusion itself may be associated with tissue injury. The pathophysiologic findings of myocardial ischemia-reperfusion are well known. However, involvement of apoptosis, as a form of tissue damage, has not neen well defined. Recently apoptosis has been suggested as a specific feature of myocardial reperfusion injury leading to late cell death. This study was performed to investigate whether reperfusion induces apoptosis irrespective of reperfusion time, and the pattern of distribution and the extent of apoptosis in rabbit myocardium. METHOD: New Zealand white rabbits weighing 1.8-2.9kg underwent 20 or 30 minutes left anterior descending(LAD) or left circumflex coronary artery occlusion followed by reperfusion for 30 minutes(n=1), 1 hour(n=1), 3 hours (n=2), and 4 hours (n=3). Ventricles were excised immediately after intervention. Tissues were fixed in 10% buffered formalin and embedded in paraffin. Apoptosis was examined by hematoxylin and eoisin(H & E) staining, in situ nick end labeling, and transmission electron microscopy. Number of apoptotic cells was evaluated semiquantitatively on H & E stained section. Myocardial tissues of ischemia only(LAD occlusion for 30 minutes, n=2) and normal rabbits(n=2) were also examined. RESULTS: Evidence of apoptosis was detected in every ischemia-reperfused myocardium irrespective of reperfusion time of 30 minutes to 4 hours. Apoptotic cells were found in the non-necrotic myocardium near necrotic areas and in islets of the non-necrotic myocarium inside necrotic areas. In the areas where apoptotic cells were distributed, the average number of apoptotic cells ranged from 1.0(30 minutes and 1 hour reperfused myocardium) to 1.1(3 hours and 4 hours reperfused myocardium) per high power field(X400)(the proportion ; less than 1% of cardiomyocytes at specific time point of reperfusion). Apoptotic cells were not detected in ischemia only and normal myocardium. CONCLUSION: These fingings suggest that apoptosis is involved as a form of cell death and it may contribute to cardiomyocyte loss not to a large extent in ischemia-reperfusion injury of rabbit myocardium.
Subject(s)
Rabbits , Apoptosis , Cell Death , Coronary Vessels , Formaldehyde , Hematoxylin , In Situ Nick-End Labeling , Ischemia , Microscopy, Electron, Transmission , Myocardial Ischemia , Myocardial Reperfusion Injury , Myocardium , Myocytes, Cardiac , Necrosis , Paraffin , Reperfusion , Reperfusion InjuryABSTRACT
BACKGROUND: Cardiac hypertrophy is the compensatory response of the myocadium to increased workload. Compensatory mechanisms come into play when the hypertrophied heart can no longer accommodate the increased demand or persistent stimuli. Although it has been reported that the molecular changes in hypertrophied hearts that initially mediate enhanced function may contribute to the development of heart failure, the structural/biochemical/molecular basis for myocardial contractile failure is still obscure. This study was aimed to clarify the structural basis for relation between hypertrophy and failure. METHOD: Nine pairs of rabbits were sacrificed at 8,12,24,48 hours and 1,2,4,6,8 weeks after experiment aortic constriction. There hearts were studied with routine histopathology. Each heart was weighed and compared with total body weight. Multiple sections were embedded in paraffin, sectioned at 5um, and stained with hematoxylin and cosin and Masson's trichrome and analysed. RESULTS: The heart weight to body weight ratio(g/Kg) increased progressively with time after aortic banding. Banding of the aorta in the rabbit resulted in multifocal areas of myofiber degeneration, necrosis and fibrosis through the wall of the left ventricle, in the papillary muscles of the left ventricle and in the left ventricular portions of the interventricular septum in rabbit of 6 and 8 weeks after aortic banding. By 4 weeks after banding, the foci of necrosis were not observed. CONCLUSION: There findings suggest that the increased necrosis, fibrosis in animals with cardiac hypertrophy induced by banding the aorta may play a role in progression to heart failure.
Subject(s)
Animals , Rabbits , Aorta , Body Weight , Cardiomegaly , Constriction , Fibrosis , Heart Failure , Heart Ventricles , Heart , Hematoxylin , Hypertrophy , Necrosis , Papillary Muscles , ParaffinABSTRACT
Arrhythmogenic right ventricular dysplasia is a rare heart muscle disorder of unknown cause that primarily involves the right ventricle. It is characterized pathologically by fibrofatty replacement of the right ventricular myocardium. Clinical manifestations include structural and functional abnormalities of the right ventricle, electrocardiographic depolarization/repolarization changes, and presentation with sudden death or ventricular arrhythmias of right ventricular origin. It is one of the important causes of the ventricular arrhythmia or sudden death among apparently healthy young people. We report a case of arrhythmogenic right ventricular dysplasia with the review of the literature.
Subject(s)
Arrhythmias, Cardiac , Arrhythmogenic Right Ventricular Dysplasia , Death, Sudden , Electrocardiography , Heart Ventricles , MyocardiumABSTRACT
Primary malignant mesothelioma of the pericardium is a very rare and highly lethal neoplasm. Diagnosis is a difficult problem and most of the cases reported in the literature were diagnosed at postmortem. We report a caseof primary malignant mesothelioma of the pericardium in a 22 year-old man. CT and MR imaging both showed diffuse irregular pericardial thickening, soft tissue density with cystic lesion, nodular bulging into the myocardium, permeative growth of the tumor, and encasement of the heart and two great vessels.
Subject(s)
Humans , Young Adult , Diagnosis , Heart , Magnetic Resonance Imaging , Mesothelioma , PericardiumABSTRACT
Viral myocarditis is considered an important cause of dilated cardiomyopathy. At preseent, two mechanisms are known to be involved in the pathogenesis of viral myocarditis and subse-quent cardiomyopathy: viral direct toxicity and immune mediated toxicity. Some authors have reported that IL-6 influences the immunologic mechanism and the virus-induced tissue damage in myocarditis. We injected encephalomyocarditis(EMC) virus to induce viral myocarditis in ICR mice. In order to study the lymphocyte subset and IL-6 expression to clarify the immune mechanism and to demonstrate the role of IL-6 in viral induced myocardial damage. The following results were obtained: 1) In virus inoculated mice, inflammation was severest at 10 days, and some serious complications developed, indicating a possible transition to dilated cardiomyopathy. 2) On analysis of the lymphocyte subset, CD4 cells were most prevalent at 5 days and CD8 cells were most prevalent at 10 and 20 days. 3) IL-6 was significantly increased and expression of IL-6 was constant, but its intensity was strongest at 5 days. In conclusion, IL-6, produced by inflammatory cells, fibroblasts, and endothelial cells, might play an important role in myocardial damage in experimentally induced EMC viral myocarditis by its direct cytotoxicity or cytokine mediated activation of cytotoxic cells.
Subject(s)
Mice , AnimalsABSTRACT
BACKGROUND: Cardiac hypertrophy is an adaptive mechanisms in response to an increased cardiac work load. Alterations in gene expression play an important role in this adaptive process. Recent investigations have indicated that the alpha-1 adrenergic stimulation in vitro induces hypertrophic change of neonatal cardiomyocytes. The signalling mechanisms of this alpha-1 agonist induced cardiomyocyte hypertrophy are largely unknown. however, recent evidence favors an effector pathway that involves phospholipase C(PLC) mediated hydrolysis of phosphatidylinositol 4,50 bisphosphate. It should be recognized that the demonstration of enhanced phosphoinositol turnover in the presence of alpha-1 adrenergic agonist in vitro does not necessarily imply that a similar response is operative in vivo. Furthermore, the role of subtypes of phospholipase C in this system should be determined. In this context, we produced in vivo cardiac hypertrophy by repeated injection of alpha-1 adrenergic agonist, phenylephrine, and tried to evaluate any change of phospholipase C subtypes by immunohistochemistry and immunoblotting technique and also measured the phosphatidylinositol hydrolyzing activity of the enzyme. METHOD: To produce cardiac hypertrophy, we injected phenylephrine 12mg/kg i.p. to the 28 female S-D rats weighing 150-250g daily for 5 days. This measures produced 22% increase of heart weight/body weight ratio. After 5 days. rats were sacrificed and hearts were rapid excised and freezed for next procedure. The immunohistochemical stainings of myocardium were carried out using monoclonal antibodies against PLC-beta1,-gamma1,-delta1 with Avidine-Biotin Complex method. Immunoblotting was done with monoclonal anti-PLC-gamma1 antibody after immnoprecipitation. The activity of PLC-gamma1 was determined in the assay mixture containing [3H] phosphatidylinositol of 20,000 cpm. The reaction was performed by incubating with resuspended immunoprecipttol of 20,000 cpm. The reaction was performed by incubating with resuspended immunoprecipitate for 10 min and supernatant was collected for -scintillation counting. RESULTS: Immunohistochemical staining demonstrated increased staining of PLC-gamma1 in the phenylephrine induced hypertrophied heart as compared with normal control heart. PLC-beta1 and-o1 did not showed any change. Elghteen out of 20 hypertrophied cardiac tissue(90%) demonstrated increased expression of the PLC-gamma1 compared with control heart tissue in immunoblotting. [3H] PI hydrolyzing activity of PLC-gamma1 in the immunoprecipitates of the hypertrophied hearts(4650+/-614 cpm) were increased consistently in 6 samples as compared with control normal hearts (2387+/-651 cpm). CONCLUSION: In the present experiments we demonstrated that Phospholipase C-gamma1 was overexpressed compared with control normal heart of rat by immunohistochemistry and immunoblotting technique and showed that the activity of this isoenzyme was elevated. Our findings of increased PLC-gamma1 expression in the alpha1-adrenergic agonist induced cardiac hypertrophy tissue suggest that the phosphatidylinositol signalling pathway is important in the genesis of cardiac hypertrophy and the isoenzyme of PLC-gamma1 may play a central role in this mechanism.
Subject(s)
Animals , Female , Humans , Rats , Adrenergic Agonists , Antibodies, Monoclonal , Cardiomegaly , Gene Expression , Heart , Hydrolysis , Hypertrophy , Immunoblotting , Immunohistochemistry , Myocardium , Myocytes, Cardiac , Phenylephrine , Phosphatidylinositols , Phospholipases , Signal Transduction , Type C PhospholipasesABSTRACT
No abstract available.
Subject(s)
Biopsy, Fine-Needle , Coinfection , Liver Abscess, AmebicABSTRACT
Fifty cases of hepatocellularcarcinoma were studied using retrospective flow cytometric(FCM) and image cytometric(ICM) DNA analysis to determine the prevalence of aneuploid cell population and whether they were associated with any particular clinico-pathologic findings. At the same time, we compared the difference between FCM and ICM. The materials were prepared from 50 micrometer cut of paraffin embedded blocks. The DNA modal values, which could be defined in 42 cases by FCM with 74% aneuploidy and in 50 cases by ICM with 76% aneuploidy. So 95% of the cases had concordant DNA ploidy results by both techniques of FCM and ICM. Abnormal DNA pattern was correlated with age(0.05). Also we found that ICM technique was easier to perform and interprete.
Subject(s)
Carcinoma, HepatocellularABSTRACT
Transmitral left ventricular diastolic inflow velocities determined by pulsed Doppler in 47 normotensives, 80 hypertensives and 44 age-matched hypertensives were measured to evaluate the effects of age and left ventricular hypertrophy on left ventricular diastolic fuction in normotensives and hypertensives. The results were as follows: 1) The peak E velocity in normotensives(77.82+/-13.53cm/sec) was significantly different from those of hyeprtensives(58.13+/-11.80cm, p0.05). Stepwise regression analysis revealed that age was the most important correlate of peak E and peak E/A in normotensives(peak E: R
Subject(s)
Heart Diseases , Hypertrophy, Left Ventricular , Linear ModelsABSTRACT
No abstract available.
Subject(s)
Biopsy , Carcinoma, Hepatocellular , Liver , Neoplasm MetastasisABSTRACT
In 22 end-stage renal disease patients on regular hemodialysis, echocardiographic study including 2-D Doppler echocardiogrphy was performed to evaluate the effect of hemodialysis on cardiac performance and the degree of valvular regurgitation. After hemodialysis, there were significant improvement of ventricular contractility and reduction of circulating volume in accordance with the reduction of degree of valvular regurgitation in comparison with before hemodialysis. We postulate that the reduction of valvular regurgitation after hemodialysis is caused by relief of hypervolemic state.
Subject(s)
Humans , Echocardiography , Echocardiography, Doppler , Kidney Failure, Chronic , Renal DialysisABSTRACT
In 40 patients with aortic regurgitation(AR), the incidence of reverse doming of anterior mitral leaflet was studied by 2-D echocardiography. Reverse doming could be indentified in 17 of 18 patients(94.4%)with severe AR, in 6 of 15 patients(14.3%)with mild AR. And in relation to the direction of regurgitant jet, reverse doming was noticed in 9 of 11 patients(82%) toward the center of left ventricular cavity. In conclusion, the appearance of reverse doming of anterior mitral leaflet is thought to be related to the degree of AR and the direction of regurgitant jet. And reverse doming by 2-D echocardiography is a helpful parameter for the diagnosis of moderate to severe AR.
Subject(s)
Humans , Aortic Valve Insufficiency , Diagnosis , Echocardiography , IncidenceABSTRACT
Phase and Amplitude Image were developed to overcome the subjective nature of interpretation for cinematic endless loop display of radionuclide gated blood pool scan. To evaluate the usefulness of color coded phase image in coronary artery disease, we conducted a clinical study with coronary angiography and phase image in 23 patients, and compared the results of those studies. 1) The results of coronary angiography revealed normal coronary artery in 6, 1 vessel disease in 11, 2 vessel disease in 4, and 3 vessel disease in 2 patients. 2) Color-coded Phase Image revealed abnormal phase area in 2/2(100%) of 3 vessel disease patients and in 3/4(75%) of 2 vessel disease patients, in 5/11(45%) of 1 vessel disease patients, and only 1/6(16%) of normal coronary artery. 3) Among the patients who disclosed abnormal phase image, 5 patients of 2-or3-vessl disease revealed abnormal phase through whole left ventricular area, but 3 patients with right coronary artery lesion and 2 patients with left antrior descending artery lesion showed localized abnormal phase area, infero-apical and anterior portion respectively, which were in accord with each coronary lesion. We concluded that the phase image may be useful in evaluation of the regional wall motion abnormalities in the patients of coronary artery disease. Further studies seem to be neccessary to clarify the sensitivity and specificity of the phase image in the each disease entity group.
Subject(s)
Humans , Arteries , Coronary Angiography , Coronary Artery Disease , Coronary Vessels , Sensitivity and SpecificityABSTRACT
Color Doppler echocardiographic examination was performed to detect and evaluate semiquantitatively the severity of mitral regurgitation in 38 patients who underwent left ventriculography. The sensitivity and specificity of the technique in the detection of mitral regurgitation was 84% and 100% as compared with left ventriculography.Mitral regurgitation in the false negative cases was mostly mild. On the bases of the farthest distance reached by the regurgitation flow signal from the mitral value orifice, the severity of regurgitation was graded on a four point scale and these results were compared with those of angiography. A significant correlation(r=0.87) was found between Doppler imaging and angiography in the evaluation of the severity of mitral regurgitation.Also results was obtained for the evaluation based on the area covered by the regurgitant signals in the left atrial cavity & the regurgitant jet area(RJA) experssed as a percentage of the left atrial are(LLA) obtained in the same plane(RJA/LLA%). In conclusion, Color Doppler echocardiography is a useful noninvasvive thechique that is not only sensitive and specific in the identification of mitral regurgitation but also provides accurate estimation og its severity.
Subject(s)
Humans , Angiography , Echocardiography , Echocardiography, Doppler, Color , Mitral Valve Insufficiency , Sensitivity and SpecificityABSTRACT
Nine patients of mean age 47.8 years, with suspected sinus node dysfunction, underwent extensive electrophysiological studies. Sinus bradycardia(6the electrophysiological study, AH and HV intervals were prolonged in 2/9 and 1/9 patients, respectively. Maximal sinus node recovery times were prolonged in 7/9 patients, ranging from 1,330 msec to 12,330msec. Sinoatrial conduction times measured by atrial premature stimulation technique were prolonged in 5/7 patients, ranging from 137msec to 310 msec. And sinoatrial conduction time measured by continuous pacing technique also revealed prolonged value in 4/6 patients ranging from 140 msec to 195 msec. The effective refractory periods, of atrium were prolonged in 6/8 patients (320 msec to 470 msec). The effective and functional refractory periods of AV node were prolonged in 3/8 patients (440 csec to 490 msec) and 4/8 patients (530 msec to 560 msec), respectively. Retrograde VA conduction could be observed in 3/7 patients and ventricular effective refractory periods were normal in 7/7 patients. Atrial flutter was induced in 1/9 patients by electric stimulation during electrophysiological study. Above data suggest that the electrophysiological study is very useful in assessing the sinus node function and other electrophysiological properties in sick sinus syndrome patients and also suggest that the data could be utilized in choosing the proper mode of artificial pacemaker for each patient.
Subject(s)
Humans , Atrial Flutter , Atrioventricular Node , Electric Stimulation , Pacemaker, Artificial , Sick Sinus Syndrome , Sinoatrial NodeABSTRACT
To dtermine the optimal timing for Aortic Valve Replacement in patients of aortic insufficiency is very important, because irreversible myocardial damage can result before symtoms such as dyspnea, syncope and chest pain, appear for the first time. Henry suggested that the echocardiographic index of left ventricular end systolic dimension 55mm could be useful as an indicator of whether to operate or not. But Fioretti, et al., insisted that there was no significant difference postoperatively between those below 55mm and those over 55mm. To determine whether a left ventricular end systolic dimension greater than 55mm is one of the risk factors for AVR in patients with aortic insufficiency, we analyzed the serial echocardiographic examinations of 23 patients who underwent AVR for isolated AI. Group I patients (n=17) had a preoperative left ventricular end systolic dimension less than or equal to 55mm and Group II patients (n=6) had a preoperative left ventricular end systolic dimension greater than than 55mm. 1) left ventricular end systolic dimension decreased in both groups significantly, and there was a statistically significant difference between Group I and Group II at 12 modths after operation. 2) Left ventricular end diastolic dimension also decreased in both groups significantly, and there was a statistically significant difference between Group I and Group II at 12 months after operation. 3) Ejection Fraction was decreased markedly just postoperatively, but it was recovered soon in both groups, and there was no statistically significant differences of the ejection fractions between the two groups postoperatively. 4) SV1+/-RV6 in EKG, as an indicator of LV mass, was also analzed and it revealed significant reduction in both groups postoperatively, but we could not observe statistically significant differences between the two groups from 6 months after the operation. We concluded that the preoperative left ventricular end systolic dimension 55mm could be useful as an index to predict postoperative prognosis and to determine the timing of aortic valve replacement.