Yumiko Kanzaki

A Case of Cardiomyopathy Showing Progression From the Hypertrophic to the Dilated Form

This report describes a case of cardiomyopathy with a novel point mutation of mitochondrial DNA coding lysine tRNA in association with severe ultrastructural alterations of the mitochondria in the cardiomyocytes. Abnormalities of energy production and/or abnormal protein synthesis because of the mutation of mitochondrial DNA may have played an important role in the pathogenesis of this case, which showed severe cardiomyocyte degeneration and deterioration from hypertrophic cardiomyopathy to severe dilated cardiomyopathy.

Giant Mitochondria in the Myocardium of a Patient With Mitochondrial Cardiomyopathy Transmission and 3-Dimensional Scanning Electron Microscopy

46-year-old man with a clinical diagnosis of dilated phase of hypertrophic cardiomyopathy was followed up at our hospital for 26 years. His refractory congestive heart failure gradually worsened over several years, and he was unresponsive to conventional medications. He then underwent left ventriculoplasty. Biochemical and genetic investigations of the left ventricular myocardium revealed a novel point mutation in the mitochondrial DNA.1 Scanning electron microscopy can directly observe both the 3-dimensional structure of a cell with high resolution and the 3-dimensional structure of the membrane system using the osmium-dimethyl sulfoxide-osmium method2 to remove the cytoplasmic matrix. Conventional transmission electron microscopy …

Three-Dimensional Architecture of Cardiomyocytes and Connective Tissue in Human Heart Revealed by Scanning Electron Microscopy

Scanning electron microscopy is a useful modality to directly observe the 3-dimensional structures of cells at high resolution. Scanning electron microscopy enables visualization of the surface features of cardiomyocytes after removal of the surrounding connective tissue1 and the connective tissue skeleton after removal of the nonfibrous elements.2 In addition, backscattered electron emission with heavy metal staining3 helps to provide high-quality images of the intracellular architecture of the cardiomyocyte. In this study, we present the 3-dimensional structure of the human left ventricular myocardium from subjects without apparent cardiac …

Sarcoidosis does not belong to or overlap with immunoglobulin G4-related diseases based on an assessment of serum immunoglobulin G4 levels in cardiac and noncardiac sarcoidosis.

Although sarcoidosis may exhibit histopathologic features similar to those of a newly emerging clinical entity, immunoglobulin G4-related sclerosing disease, sarcoidosis is currently not considered to be associated with immunoglobulin G4-related immunoinflammation. Not many studies on this association have been reported. We investigated serum immunoglobulin G4 levels among patients with sarcoidosis with or without cardiac involvement (cardiac sarcoidosis and non-cardiac sarcoidosis patients). The mean serum immunoglobulin G4 level among the 65 patients with sarcoidosis was 56.8 ± 43.0 mg/dL, which did not significantly differ between patients with cardiac sarcoidosis (54 ± 48 mg/dL, n = 12) and patients without cardiac sarcoidosis (58 ± 42 mg/dL; n = 53). Serum level of soluble interleukin 2 receptor, a potent marker that may reflect sarcoidosis activity, was elevated in cardiac sarcoidosis (910 ± 683 U/L) and noncardiac sarcoidosis (689 ± 399 U/L) but did not significantly differ between the groups. Immunohistochemistry of cardiac or lymph node specimens from patients with cardiac sarcoidosis showed only sparse or no infiltration of immunoglobulin G4-positive lymphocytes, in contrast to the moderate to severe infiltration of CD68-positive macrophages and CD45-positive lymphocytes. Although the number of study subjects was small, these findings collectively suggest that regardless of the presence or absence of cardiac involvement, sarcoidosis does not belong to or overlap with immunoglobulin G4-related sclerosing disease.

Backscattered electron imaging: A new method for the study of cardiomyocyte architecture using scanning electron microscopy.

Scanning electron microscopy (SEM) with secondary electron emissions is useful for the study of cardiomyocyte architecture, however, the information is limited from the cell surface. Whereas backscattered electron (BSE) emission can give a high-resolution image of the specimens intracellular structure after heavy metal staining. In this study, we applied BSE imaging analysis to the study of the arrangement of cardiomyocytes in the myocardium. The tissue specimens from a normal fresh monkey heart, normal human heart obtained at autopsy, and surgically resected tissue from a patient with old myocardial infarction in the left ventricular aneurysmectomy were used. The tissue specimens were fixed in neutral formalin, treated with NaOH and then stained with Gomoris silver methenamine reagent followed by tannic acid and osmium tetroxide. After dehydration and drying, the specimens were coated with carbon and examined by SEM with a BSE detector. In the tissue preparations, the A bands of sarcomeres were selectively stained with silver so that the arrangements of subsarcolemmal myofibrils and the intercalated discs were clearly seen in the BSE images. In the left ventricular aneurysmal walls of old myocardial infarction, atrophied cardiomyocytes with disarray of subsarcolemmal myofibrils were observed. The results strongly suggest that BSE images are further applicable to the study of the architecture of cardiac myocytes and their branches, and the arrangement of intracellular myofibrils in various diseased myocardium.

Markedly increased intracellular lipid droplets and disruption of intercellular junctions in biopsied myocardium from a patient with arrhythmogenic right ventricular cardiomyopathy

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is characterized by the progressive replacement of myocardial cells by fat and fibrous tissue. Here we describe the histopathological features of biopsied myocardium from a patient with ARVC. A large amount of adipose tissue was present in the biopsy specimen, and a group of myocardial cells were isolated as an island-like region in the adipose tissue. Electron microscopic examination of cardiomyocytes revealed a large number of intracellular lipid droplets, including some extremely large droplets. Disruptions of the plasma membrane and dissociation of intercellular junctions were associated with discharge of intracellular lipid droplets into the interstitial space. The high accumulation of intracellular lipid droplets may be involved in the pathogenesis of ARVC and may have played an important role in myocardial cell death and progressive replacement of cardiomyocytes by fatty tissue in the current case.

Three-Dimensional Architecture of Cardiomyocytes and Connective Tissues in Hypertrophic Cardiomyopathy A Scanning Electron Microscopic Observation

Scanning electron microscopy is a useful modality to visualize the 3-dimensional structures of tissues at high resolution. In addition, processing the tissue samples can provide further architectural information: The removal of connective tissue around the cardiomyocytes and, conversely, the removal of nonfibrous tissue enable us to clearly observe the cardiomyocytes and connective tissue, respectively. Furthermore, backscattered electron emission after heavy-metal staining can provide higher-quality images of the intracellular architecture.1 We have previously reported the 3-dimensional structure of the human left ventricular myocardium.2 Here, we performed an electron …

Three-Dimensional Observation of the Intracellular Membrane Structure in Human Myocardium High-Resolution Scanning Electron Microscopy by the Osmium-DMSO-Osmium Method

Scanning electron microscopy (SEM)⇓ can directly observe the 3D structures of a cell with high resolution. Tanaka and Naguro1 reported a unique SEM method (osmium-DMSO-osmium method) to observe the 3D structure of the membrane system to remove cytoplasmic matrix much more effectively than any other method. With this method, the 3D features of the endoplasmic reticulum, Golgi complex, mitochondria, transverse tubules, intercalated disks, surface vesicles, and sarcolemma of a cell can be clearly observed.1 2 We first applied this method to tissue specimens of human …Scanning electron microscopy (SEM) can directly observe the 3D structures of a cell with high resolution. Tanaka and Naguro1 reported a unique SEM method (osmiumDMSO-osmium method) to observe the 3D structure of the membrane system to remove cytoplasmic matrix much more effectively than any other method. With this method, the 3D features of the endoplasmic reticulum, Golgi complex, mitochondria, transverse tubules, intercalated disks, surface vesicles, and sarcolemma of a cell can be clearly observed. 1,2

Primary Leiomyosarcoma in the Inferior Vena Cava Extended to the Right Atrium: A Case Report and Review of the Literature.

A 38-year-old woman had developed an abdominal distention, lower extremity edema, and dyspnea. Imaging examination revealed a large mass in the right atrium which was connected to lesions within the inferior vena cava. Although complete resection of the mass was not possible, partial surgical tumor resection was performed to avoid pulmonary embolization and circulatory collapse. Leiomyosarcoma was diagnosed histologically, and chemotherapy (doxorubicin) followed by radiotherapy was started. By reviewing papers published in the past 10 years that included 322 patients, we also discuss the clinical presentations and prognosis of leiomyosarcoma in the inferior vena cava.

Images in cardiovascular medicine. Three-dimensional remodeling of cardiomyocytes in a patient with aortic stenosis: scanning electron microscopy.

A 77-year-old man was admitted to our hospital because of anterior chest pain. An echocardiogram demonstrated aortic valvular stenosis with calcification of the whole aortic root, concentric left ventricular hypertrophy, and slightly reduced left ventricular wall motion. Cardiac catheterization study showed a peak transaortic pressure gradient of 89 mm Hg and an aortic valve area of 0.52 cm2. We were planning surgical treatment, but the patient suddenly …A 77-year-old man was admitted to our hospital because of anterior chest pain. An echocardiogram demonstrated aortic valvular stenosis with calcification of the whole aortic root, concentric left ventricular hypertrophy, and slightly reduced left ventricular wall motion. Cardiac catheterization study showed a peak transaortic pressure gradient of 89 mm Hg and an aortic valve area of 0.52 cm2. We were planning surgical treatment, but the patient suddenly …