Expression of tumor necrosis factor-alpha--converting enzyme and tumor necrosis factor-alpha in human myocarditis.

OBJECTIVES: We determined whether tumor necrosis factor-alpha-converting enzyme (TACE) is expressed with tumor necrosis factor-alpha (TNF-alpha) in myocarditis. BACKGROUND: Tumor necrosis factor-alpha-converting enzyme, which has recently been identified as belonging to the family of metalloproteinase disintegrin proteins, is responsible for the conversion of TNF-alpha precursor to its mature form. METHODS: We examined TACE and TNF-alpha expressions in endomyocardial biopsy tissues obtained from 14 patients with myocarditis and five control subjects by using quantitative reverse transcriptase polymerase chain reaction and immunohistochemistry. RESULTS: Expression of TNF-alpha and TACE messenger ribonucleic acid (mRNA) was significantly greater in the myocarditis group than in the control group. A positive correlation was found between TNF-alpha and TACE mRNAs (r = 0.83, p < 0.05). Six patients with severe myocarditis underwent repeat biopsies. Although TNF-alpha and TACE mRNAs were expressed at high levels in the initial biopsies, a marked decrease was noted in the repeat biopsies. The immunostainings for TNF-alpha and TACE were positive in the myocytes and interstitial cells of myocardium obtained from patients with myocarditis. Expression of TACE and TNF-alpha mRNAs was greater in the subgroup in New York Heart Association functional class III or IV than in the subgroup in class I or II. Expression of TACE and TNF-alpha mRNA was correlated positively with left ventricular volume (TNF-alpha: r = 0.85; TACE: r = 0.80) and negatively with left ventricular systolic function (TNF-alpha: r = -0.85; TACE: r = -0.85). CONCLUSIONS: These findings indicate that the expression of TNF-alpha and TACE may have important implications in the pathogenesis of myocarditis and may influence advanced cardiac dysfunction in myocarditis.

What determines the heart rate response to exercise in patients with atrial fibrillation?

We evaluated the factors that determine the heart rate response to exercise in 60 patients with atrial fibrillation (25 men and 35 women, with a mean age of 61+/-10 years) who underwent symptom limited cardiopulmonary exercise testing with blood sampling of atrial natriuretic peptide (ANP), 2-dimensional echocardiography and cardiac catheterization. Atrial muscles resected during the Maze operation were examined histologically in 12 patients. The heart rate response to exercise depended on the severity of the atrial organic injury, which was expressed as left atrial diameter, ANP secretion during the maximal exercise testing and the histological findings of atrial tissue. Conversely, we believe that the severity of the atrial injury can be predicted from the heart rate response to exercise in patients with atrial fibrillation.

Dilated cardiomyopathy in Noonan's syndrome: a first autopsy case.

The first autopsy case of dilated cardiomyopathy associated with Noonan's syndrome is described. A 9-month-old girl with Noonan's syndrome died from cardiac failure. Autopsy showed biatrial and biventricular enlargement of the heart. The posterior half of the ventricular septum and right ventricular wall were remarkably thin. Other parts of the wall were nearly normal in thickness, but both ventricular cavities were dilated. Microscopically, the myocardium of both ventricles consisted of mainly abnormally thinned, elongated, and loosely arranged myocardial fibers lacking immunoreactivity to anti-dystrophin antibody. Myocardial disarray was not found except for where it normally existed. The abnormal changes of the myocardial fibers were considered to be primary. Common cardiomyopathy associated with Noonan's syndrome is a hypertrophic type. Various types of cardiovascular abnormality associated with Noonan's syndrome, including dilated cardiomyopathy, might be disclosed by further investigation and precise diagnosis of Noonan's syndrome.

Tumor necrosis factor-alpha-converting enzyme and tumor necrosis factor-alpha in human dilated cardiomyopathy.

BACKGROUND: Tumor necrosis factor-alpha (TNF-alpha) has been implicated in the pathogenesis of dilated cardiomyopathy (DCM). TNF-alpha-converting enzyme (TACE) has recently been purified and its complementary DNA cloned. The expression of TACE results in the production of a functional enzyme that has precursor TNF-alpha in the mature form. The aim of this study was to determine whether TACE is expressed with TNF-alpha in myocardium and whether levels of TACE and TNF-alpha are related to clinical severity of DCM. METHODS AND RESULTS: Endomyocardial tissues were obtained from 30 patients with DCM and 5 control subjects. TNF-alpha and TACE mRNA levels were measured by a novel real-time quantitative reverse transcriptase-polymerase chain reaction method. Expression of TNF-alpha and TACE proteins was determined by immunohistochemical analysis. TNF-alpha mRNA was expressed in DCM patients (TNF-alpha/GAPDH ratio 0.85+/-0.24) but not in control subjects. TACE mRNA expression was significantly greater in DCM patients than in control subjects (TACE/GAPDH ratio 2.52+/-0.59 vs 0.03+/-0.02, P<0.05). A positive correlation was found between TNF-alpha and TACE mRNA levels (r=0.779, P<0.001). TACE and TNF-alpha immunostaining was observed in myocytes in patients with DCM. When 2 subgroups of DCM were divided on the basis of left ventricular end-systolic diameter (LVESD) of 45 mm and left ventricular ejection fraction (LVEF) of 40%, the DCM subgroup with high LVESD (>/=45 mm) showed significantly greater expression of TACE (P=0.02) and TNF-alpha (P=0. 001) than did the low LVESD subgroup (<45 mm). In addition, the DCM subgroup with lower LVEF (<40%) showed higher expression of TACE (P=0.006) and TNF-alpha (P=0.01) than did the subgroup with high LVEF (>/=40%). CONCLUSIONS: This study has shown that increased myocardial TACE expression is associated with elevated myocardial TNF-alpha expression in both mRNA and protein levels in clinically advanced DCM.

Inducible nitric oxide synthase and tumor necrosis factor-alpha in myocardium in human dilated cardiomyopathy.

OBJECTIVES: We examined the mRNA expression and protein localization of inducible nitric oxide synthase (iNOS) and tumor necrosis factor-alpha (TNF-alpha) in myocardial tissue obtained from patients with dilated cardiomyopathy (DCM). BACKGROUND: The etiology of DCM is unknown, but viral infection or autoimmune abnormalities that induce cytokine expression have been proposed as pathogenetic factors. Nitric oxide (NO), synthesized by nitric oxide synthase (NOS), has negative inotropic and cytotoxic effects on cardiomyocytes. Cytokines such as TNF-alpha are potent stimulators of iNOS expression. Expression of iNOS leads to excessive production of NO in the myocardium and may modulate cardiac contractility and ventricular morphology. METHODS: We examined the mRNA expression and protein localization of iNOS and TNF-alpha in myocardial tissue obtained from 24 patients with DCM, 20 patients with hypertrophic cardiomyopathy (HCM) and 15 control subjects, using the reverse transcriptase-polymerase chain reaction method and immunohistochemical studies. We then compared the differences in clinical characteristics between DCM patient subgroups with and without myocardial iNOS expression. RESULTS: Messenger RNA expression of iNOS and TNF-alpha was observed, respectively, in 13 (54%) and 18 (75%) patients with DCM. Gene expression of TNF-alpha was consistently detected in endomyocardial tissue from patients with DCM and INOS expression. Inducible NOS protein was evident only in cardiomyocytes, whereas TNF-alpha was apparent in both cardiomyocytes and endomyocardial endothelium. Neither mRNA expression nor protein localization of iNOS or TNF-alpha was observed in cardiac tissue obtained from patients with HCM or control subjects. Patients with DCM and iNOS mRNA showed a lower left ventricular ejection fraction (p < 0.01) and a higher left ventricular volume (p < 0.05) than the negative DCM group. CONCLUSIONS: Inducible NOS was consistently coexpressed with TNF-alpha in myocardial tissue obtained from a subgroup of patients with DCM and advanced left ventricular dysfunction.

Association of myotonic dystrophy and sick sinus syndrome, with special reference to electrophysiological and histological examinations.

Sick sinus syndrome is a rare but potentially important cardiac disorder in patients with myotonic dystrophy. We evaluated 3 patients with myotonic dystrophy complicated with sick sinus syndrome using intracardiac electrocardiography and endomyocardial biopsy. Electrocardiography identified sinus arrest, atrial flutter and right bundle-branch block in 2 cases and marked sinus bradycardia and first-degree atrioventricular block in 1 case. Their sinus node recovery times were significantly prolonged as demonstrated by the overdrive suppression test. Two patients had Adams-Stokes syndrome and one had tachycardia with severe palpitations. Therefore permanent pacemaker implantation was indicated in all 3 cases. Light microscopic analysis of right ventricular endomyocardial biopsies showed vacuolar degeneration and nuclear deformity of cardiomyocytes in all cases and endocardial and interstitial fibrosis in 1 case. These findings indicate that pathological changes may occur in any part of the myocardium in patients with myotonic dystrophy.

Simple method for quantifying disorientation of myofiber in endomyocardial biopsy specimens using an image analyzer.

The disarray of cardiac myofibers was morphometrically evaluated in biopsy specimens, obtained from patients with hypertrophic cardiomyopathy (HCM), hypertensive heart disease (HHD), chronic phase myocarditis and controls. Microphotographs of myocardium were taken at a final magnification of x 250. For each segment of myofibers, the longitudinal direction was traced on a transparent sheet, and the angle of the traced direction to the baseline was measured by an image analyzer. The standard deviation of the angles was used as an indicator of myofiber disarray. The histograms showed a narrow variation in the control group, but a wide variation in the patients with HCM, HHD and chronic phase myocarditis. The mean value of standard deviations of myofiber angles in HCM was significantly larger than that in the other groups. In HCM, the standard deviation of the myofiber angle proved to correlate positively with IVST/LVPWT (the thickness ratio of interventricular septum to the left ventricular posterior wall) (r = 0.70, p < 0.05), and also with LVEDP (left ventricular end-diastolic pressure) (r = 0.66, p < 0.05). In conclusion, the image analyzer serves as a simple and useful tool in quantifying the disorientation of myofibers and estimating the correlation between the histological and clinical findings.

Expression of cytokine genes and presence of enteroviral genomic RNA in endomyocardial biopsy tissues of myocarditis and dilated cardiomyopathy.

Viral infection, especially by enteroviruses, has been considered to be the most common cause of myocarditis, which may progress to dilated cardiomyopathy (DCM). Although the mechanism of progression remains uncertain, a cytokine-associated injury of myocytes has been proposed. Using reverse transcriptase polymerase chain reaction (RT-PCR), we examined the expression of interleukin 1 beta (IL-1 beta), IL-6, IL-8 and tumour necrosis factor alpha (TNF-alpha) and the presence of enteroviral genomic RNA in endomyocardial biopsy tissues obtained from patients with myocarditis and DCM. We examined endomyocardial biopsy tissues obtained from 6 patients with myocarditis, 21 with DCM and 15 with non-infectious cardiac diseases as controls. In patients with myocarditis, endomyocardial biopsy was performed twice at an interval of 1 month to 8 years after the onset of myocarditis. We used RT-PCR to detect IL-1 beta, IL-6, IL-8 and TNF-alpha genes expression and nested RT-PCR (nRT-PCR) to detect enteroviral genomic RNA. IL-1 beta, IL-6, IL-8 and TNF-alpha genes were expressed in 100% (6/6) and enteroviral genomic RNA in 67% (4/6) of myocarditis patients at the first biopsy. At the second biopsy, IL-1 beta, IL-6, IL-8 and TNF-alpha genes were expressed in none, 50% (3/6), 67% (4/6) and 67% (4/6), respectively, and enteroviral genomic RNA in 67% (4/6). Four patients with myocarditis, in whom IL-8 and TNF-alpha genes and enteroviral genomic RNA were detected, progressed to DCM at the second biopsy. IL-1 beta, IL-6, IL-8 and TNF-alpha genes were expressed in none, 24% (5/21), 38% (8/21), 57% (12/21) of DCM patients, respectively. Enteroviral genomic RNA was detected in 43% (9/21) of DCM. Neither cytokine expression nor enteroviral genomic RNA were detected in the controls. the high incidence of cytokines, especially IL-6, IL-8 and TNF-alpha, expression in myocarditis and DCM, which might be induced by enteroviral infection, suggests that cytokines play an important role in myocytic damage leading to DCM.

Enteroviral RNA in dilated cardiomyopathy.

The exact cause of dilated cardiomyopathy (DCM) remains uncertain. However, a possibility of transition from coxsackievirus-infected myocarditis to DCM has been suspected. We investigated the role of enteroviral infection in the pathogenesis of DCM. The nested reverse transcriptase polymerase chain reaction (nRT-PCR) was used to detect enteroviral RNA in 45 endomyocardial biopsy tissues obtained from 35 patients with DCM and 10 patients (controls) with other non-infectious cardiac diseases. Enteroviral RNA was detected in 17 (49%) of the 35 patients with DCM. The progression to cardiac failure was rapid, usually within 12 months, and myocardial fibrosis and myocytic hypertrophy were marked in patients that were enteroviral RNA positive. Enteroviral RNA was not detected in any controls.

Enteroviral RNA in endomyocardial biopsy tissues of myocarditis and dilated cardiomyopathy.

Enteroviruses are potential etiologic agents of myocarditis and dilated cardiomyopathy (DCM). A recently developed molecular approach has offered evidence of viral infection by detecting the virus genome. The nested reverse transcriptase polymerase chain reaction (nRT-PCR) was used to detect enteroviral RNA in endomyocardial biopsy tissues of myocarditis and DCM. The authors examined 44 tissues obtained from 36 patients with myocarditis, as well as from 10 patients with non-infectious cardiac diseases as controls. Enteroviral RNA was detected in 12 of 36 patients with myocarditis. The second endomyocardial biopsy was carried out in five of the patients, in whom enteroviral RNA was detected at the first biopsy, at intervals from 3 weeks to 8 years after the first biopsy, and enteroviral RNA was found in four and had disappeared in one. In one of the four positive patients at the second biopsy, a third biopsy was carried out 5 months later (6 months after the first), and the RNA was detected. Active myocarditis became clinically and microscopically mild at the second and third biopsies. In one patient who developed DCM, enteroviral RNA was also detected at a second biopsy performed 8 years after the first. Enteroviral infection is a probable cause of myocarditis and enterovirus-infected myocarditis may progress to DCM.

Origin of so-called mesothelioma of the atrioventricular node. An immunohistochemical study.

To determine the origin of a mesothelioma of the atrioventricular node, immunohistochemical studies that used various antibodies, including the antibody against mesothelial cells, were performed on a mesothelioma of the atrioventricular node in a case. The lining cells of the tubules that composed the tumor were negative when tested with anti-mesothelial cell antibodies. Carcinoembryonic antigen was negative, but the secretory component was positive. Serotonin and calcitonin were positive in a few cells. We concluded that a mesothelial origin was unlikely, and it was suggested that the tumor was of an entodermal origin.

A case of subungual amelanotic malignant melanoma: an electron microscopic study of aberrant melanosomes.

A 68-year-old woman with amelanotic malignant melanoma (AMM) of her left thumbnail bed was reported. The tumor cells were positive with S-100 protein. Electron microscopic findings revealed the presence of typical melanosomes and a variety of aberrant melanosomes within the tumor cells, obviously different from the results for common malignant melanoma.

Histological changes in cardiac hemochromatosis improved by an iron-chelating agent. A biopsy case.

Cardiac dysfunction and ECG abnormalities were demonstrated in a 51-year-old woman suffering from secondary hemochromatosis in sideroblastic anemia. Hemosiderin deposition in vacuolized and disarrayed myocytes was disclosed by microscopic examination of the first biopsy specimen of endomyocardial tissue. Three months after administration of deferoxamine mesylate, an iron-chelating agent, the clinical findings were improved. The second endomyocardial biopsy revealed marked depletion of hemosiderin deposition in the myocytes, and improvement of myocyte vacuolization and disarray. Ultrastructurally, the highly electron-dense granules in the myocytes were also decreased in number and density. X-ray microanalysis revealed a prominent peak of Fe in the granules. In a liver specimen obtained by needle biopsy 5 months after the second endomyocardial biopsy, marked hemosiderin deposition still remained.

Relation between myocardial histological changes and ventricular tachycardia in cardiomyopathy: a study by 24-hour ECG-monitoring and endomyocardial biopsy.

The relation between myocardial histological changes and ventricular tachycardia (VT) in cardiomyopathy was investigated. Right ventricular endomyocardial biopsy and 24-hour ECG-monitoring were performed in 19 patients with dilated cardiomyopathy (DCM) and 22 with hypertropic cardiomyopathy (HCM). Cardiomyopathy was histologically divided into the following four groups: group A, hypertrophy without disarray of myocytes (3 DCM and 7 HCM); group B, hypertrophy with disarray of myocytes (14 HCM); group C, fibrosis (9 DCM and 1 HCM); and group D, diffuse myocytic degeneration (7 DCM). VT was observed in 20% (2 of 10 patients) of group A, 14% (2 of 14) of group B, 80% (8 of 10) of group C, and 71% (5 of 7) of group D. The degenerating myocytes and/or the irregular distribution of fibrosis may play an important role in the etiology of VT in cardiomyopathy.

Morphometric comparison of mitochondria and myofibrils of cardiomyocytes between hypertrophic and dilated cardiomyopathies.

We performed an ultrastructural, morphometric comparison of mitochondria and myofibrils of cardiomyocytes using endomyocardial biopsy specimens in hypertrophic cardiomyopathy (HCM) and dilated cardiomyopathy (DCM). Biopsies came from the right ventricular side of the interventricular septum in nine patients with HCM, nine with DCM, and nine controls with arrhythmia and/or ST depression. Morphometric analysis was carried out using electron microscopic photographs and an image analyser. Mitochondria were significantly greater in number and smaller in size in HCM than in the control group. In DCM, the size of mitochondria was also significantly smaller than in the control group, although their number was similar to that of the control group. No statistically significant difference was found regarding the size of mitochondria between HCM and DCM. The percentages of both mitochondrial and myofibrillar areas in cytoplasm were smaller in the DCM than the HCM and control groups, though no difference was seen between the latter two. The ratio of mitochondrial area to myofibrillar area was almost the same in each group. These results suggest increased mitochondrial function to match hypertrophic cardiomyocytes in HCM, and decreased mitochondrial function and cardiomyocytic contractility in DCM.

Total body water, total exchangeable sodium and potassium in patients with convalescent acute myocardial infarction one to two months after onset.

Total exchangeable sodium (Nae), potassium (Ke), and total body water (TBW) were measured by the multiple isotope dilution method, in 10 healthy subjects (normal), 10 patients with congestive heart failure (CHF), and 47 patients with acute myocardial infarction (AMI), 1-2 months after onset. According to Killip's classification, 29 patients with AMI were classified as class I, and 18 patients were classified as class II and III (referred to as class II & III). No differences were found in plasma and urine sodium and potassium concentrations. By the multiple isotope dilution method, significant elevations in Nae/BSA (body surface area) were observed in the following order: normal, class I, class II & III and patients with CHF. Compared with normal subjects, Nae/BSA and Nae/Ke were elevated in class I patients. Elevations of Nae/Ke and TBW/BSA in both class II & III patients with AMI and patients with CHF indicated severe cardiac impairment. Both Nae/BSA (p = -0.60) and Ke/BSA (p = 0.71) had negative and positive correlations with the left ventricular ejection fractions (EF) measured by catheterization in 20 patients with AMI. This indicates a major sodium and water retention mechanism due to impaired cardiac function in AMI. It is worth noting that conspicuous abnormalities in body fluid compositions, particularly in class I patients with AMI as well as class II & III, remained despite no evidence of cardiac failure.

Myocardial lesions by Coxsackie virus B3 and cytomegalovirus infection in infants.

Immunofluorescent and electron-microscopic studies were performed to determine the distribution of viral antigens and particles and to clarify the relationship to myocardial lesions in two autopsy cases with generalized infection of Coxsackie virus B3 (CVB3) or cytomegalovirus (CMV). Case 1 was a full-term newborn female infant, without any congenital anomalies, who died of cardiac failure 10 days after birth. CVB3 was isolated from the blood before death. Necrosis of the muscle fibers was observed, frequently accompanying calcification. Numerous histiocytes and a few lymphocytes and neutrophils had infiltrated in and around the necrotic areas. Immunofluorescent study (IF) revealed CVB3 antigen in the muscle fibers and vascular endothelial cells. Case 2 was a female infant, born at 28 weeks of gestation, who died of fatal arrhythmia 50 days after birth. The infant had hemocephalus and a history of idiopathic respiratory distress and underwent an operation for patent ductus arteriosus. Cytomegalic cells were frequently found in the vascular endothelial cells in the myocardium and occasionally in muscle fibers. IF showed the presence of CMV antigen in both endothelial cells and muscle fibers. CVB3 and CMV antigens were detected predominantly in vascular endothelial cells rather than in the muscle fibers. Blood flow disturbance due to endothelial damage is a cause of the myocardial lesion in addition to the direct invasion of the muscle fibers by the virus.