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H Tsuchimochi

Publications and source records attributed to H Tsuchimochi.

At least 37 records · Page 2Linked to original sources
PubMed1989

Effect of long-term treatment with beta-blocker on cardiac hypertrophy in SHR.

Recent studies suggest that beta-blocker treatment may attenuate cardiac hypertrophy induced by pressure overload in the spontaneously hypertensive rat (SHR), but the effect of this therapy on the reconstitution of the intracellular constituents in the heart that occurs during the development of cardiac hypertrophy has not been examined. In this study, we investigated the effect of chronic administration of carteolol (4 mg/kg/day p.o.) or propranolol (20 mg/kg/day p.o.), beta-blockers with distinct modes of action, on the composition of cardiac myosin isozymes and histological findings as well as heart weight. Therapeutic periods were 4, 12 or 30 weeks. Though blood pressure was not significantly reduced, the development of cardiac hypertrophy was suppressed as evidenced by left ventricular weight in both groups of carteolol- and propranolol-treated SHR for all therapeutic periods. Again, beta-blocker treatment for 12 weeks alleviated myocardial degeneration and reactive fibrosis which were observed in all cases of age-matched untreated SHR. However the extent of the transition of cardiac myosin isozymes from V1 to V2 or V3 were essentially the same among all groups including untreated SHR. These results indicate that chronic administration of beta-blockers attenuates the development of cardiac hypertrophy and degeneration without affecting the transition of myosin isozymes which is thought to be a kind of biochemical adaptation of the myocardium to overload.

Adrenergic beta-Antagonists↗
PubMed1989

[Cosmetic cranioplasty using the bone chips and Biobond (EDH-adhesive): technical note].

A new and simple cosmetic procedure for the prevention of skin depression produced by burr-holes was presented. A mixture of the bone chips obtained at craniotomy and Biobond in a volume ratio of 7:3 was used to fill the bone defect of the burr-holes in 65 cases. The postoperative appearance was excellent cosmetically. This mixture had good plasticity, and could be formed into any irregular shape desired, and there was no increase in the incidence of infectious complications.

Bone Transplantation↗
PubMed1988

Molecular cloning and characterization of human atrial and ventricular myosin alkali light chain cDNA clones.

We have isolated essentially full-length cDNA clones for atrial (ALC1) and ventricular (VLC1) myosin alkali light chains from a human fetal heart cDNA library. Comparison of overall nucleotide sequences of ALC1 and VLC1 cDNA clones has revealed that, while these two inserts show significant DNA sequence homology (78.4%) with respect to their coding regions, the 5'- and 3'-untranslated regions are highly divergent. Our statistical analysis suggests that human ALC1 and VLC1 diverged approximately 300 million years ago, during the time of separation of birds and mammals. RNA blot analysis shows that ALC1 mRNA is expressed in fetal ventricular and fetal skeletal muscles as well as fetal and adult atrial muscles and VLC1 mRNA is expressed in adult slow skeletal muscle as well as fetal and adult ventricular muscles. Southern blot analysis indicates that each protein is encoded by a single gene. Finally, we show that VLC1 mRNA is induced in pressure-overloaded human atrium.

Adult↗
PubMed1988

Atrial natriuretic peptide distribution in fetal and failed adult human hearts.

The distributions of atrial natriuretic peptide (ANP) in human hearts during the developmental stage and in adult pathological states was examined with an antibody specific to human alpha-ANP. With immunoblotting and immunofluorescence methods, we found that a 17-kDa protein, which is a pro ANP, was expressed in human fetal ventricles, in which the numbers of myofibers containing ANP granules were more abundant in the subendocardial region than the subepicardial region. As determined by radioimmunoassay, the content of immunoreactive ANP (per milligram protein) in the developing heart was greatest in the left atrium and occurred decreasingly in the right atrium, right ventricle, and left ventricle, respectively. Because ANP content in the left ventricle declined during the progress of gestation in developing hearts and because it was very low, if ever detectable, in normal adult hearts, ventricular ANP expression appears to be developmentally regulated from the early gestational stage. However, it was reexpressed in the ventricles of patients who had suffered from severe congestive heart failure. In this situation, we found that the ventricular ANP expression was more marked in patients with dilated cardiomyopathy than in patients with severe valvular disease. Interestingly, in the ventricles of patients with dilated cardiomyopathy, ANP contents were higher in the left ventricular free wall than in the right ventricular free wall, although the left ventricular subendocardium contained more ANP than the subepicardium, showing a transmural gradient similar to that expressed in fetal ventricles. Thus, the expression of ANP in human ventricles is developmentally regulated from the early gestational stage, and even adult ventricular myofibers can synthesize ANP during severe congestive heart failure.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Differences in response of myosin isozyme transition of ordinary and specialized myocardium to overload.

To investigate the response of myosin isozyme transition in specialized myocardium to cardiac overload, we examined immunohistochemically the distribution of myosin isozymes in sinus node cells of overloaded canine atria, using the monoclonal antibodies CMA19 and HMC14, which are specific for atrial myosin heavy chain (alpha-HC) and ventricular myosin heavy chain (beta-HC), respectively. Overloading in canine right atria was induced by artificial tricuspid valve regurgitation and pulmonary stenosis. Right atrial mean pressure rose to 15-20 mm Hg (n = 4) 2 months after surgery. In the working myocardium, cardiac overload caused redistribution of myosin isozymes, alpha-HC to beta-HC. Compared with the normal right atria, fewer myocytes were labeled with CMA19, but more were labeled with HMC14. However, the reactivity of sinus node cells with CMA19 and HMC14 was not changed between normal and overloaded right atria, indicating no redistribution of myosin heavy chain isozymes, alpha-HC to beta-HC. These results suggest that isozymes in myosin heavy chains in the specialized myocardium are protected from overload effects by their firm cytoskeletal framework or other mechanisms.

Animals↗
PubMed1988

Heterogeneity of beta-type myosin isozymes in the human heart and regulational mechanisms in their expression. Immunohistochemical study using monoclonal antibodies.

To investigate the existence of heterogeneity of beta-type myosin isozymes (HC beta) in human hearts, immunohistochemical studies using monoclonal antibodies (MoAbs) raised against human ventricular myosin heavy chains were performed. Two types of MoAbs recognized some muscle fibers in the atrium, whereas both reacted with all ventricular muscle fibers. Since atrial muscle fibers reactive with each MoAb were found to be clearly different, the existence of two immunologically distinct HC beta (beta 1, and beta 2) was suggested in the atrium. By using affinity chromatography, two molecular variants of HC beta were isolated from the bovine atrium, and differences in the primary structure of beta 1 and beta 2 were confirmed by analysis of peptides produced by chymotryptic digestion. In pressure-overloaded human atria, myofibers containing beta 1 and/or beta 2 increased in accordance with decrement of myofibers containing alpha-type myosin isozyme (P less than 0.01). But they differed in expression during the developmental stage, since beta 2 did not exist in the early embryonic bovine heart, but beta 1 did. Thus, there are two distinct HC beta whose expression is regulated by at least two factors: pressure overload and developmental stage.

Adult↗
PubMed1988

Molecular cloning and characterization of human cardiac alpha- and beta-form myosin heavy chain complementary DNA clones. Regulation of expression during development and pressure overload in human atrium.

We have constructed and characterized two types of myosin heavy chain (MHC) cDNA clones (pHMHC2, pHMHC5) from a fetal human heart cDNA library. Comparison of the nucleotide and deduced amino acid sequences between pHMHC2 and pHMHC5 shows 95.1 and 96.2% homology, respectively. The carboxyl-terminal peptide and 3'-untranslated (3'-UT) regions are highly divergent and specific for these cDNA clones. By using the synthetic oligonucleotide probes that are complementary to the unique 3'-UT regions of these cDNA clones, we demonstrate that pHMHC2 is exclusively transcribed in the atrium, whereas the mRNA for pHMHC5 is predominantly expressed in the ventricle. This result indicates that pHMHC2 and pHMHC5 code for alpha- and beta-form MHCs, respectively. Furthermore, we show that beta-form MHC mRNA is expressed in adult atrium at a low level but scarcely expressed in fetal atrium. Finally, we demonstrate that MHC isozymic transition in pressure-overloaded atrium is, at least in part, regulated at a pretranslational level.

Adult↗
PubMed1987

Quantitative relationship between left ventricular function and serum cardiac myosin light chain I levels after coronary reperfusion in patients with acute myocardial infarction.

To estimate the extent of myocardial infarction after coronary artery reperfusion, serum levels of cardiac myosin light chain (LC) I and creatine kinase (CK) were determined serially in 49 patients with acute myocardial infarction. Intracoronary thrombolysis was successful in 25 patients (reperfusion group), and 24 patients were treated in a conventional manner (control group). The peak level of CK appeared significantly earlier in the reperfusion group (11.3 +/- 3.1 hr, mean +/- SD) than in the control group (21.6 +/- 7.2 hr). Cumulative release of CK was significantly related to angiographically determined left ventricular ejection fraction 1 month after the attack in both groups (r = -.50; -.45, respectively). However, the amount of cumulative release of CK in the reperfusion group was greater compared with that in those with the same left ventricular ejection fraction in the control group. Peak appearance time of LCI was almost equal in the two groups (3.8 +/- 1.4 vs 3.9 +/- 1.2 days). Peak levels of LCI were related to the left ventricular ejection fraction in the reperfusion group (r = -.63) and in the control group (r = -.74), and the slopes of their regression lines were similar. The cardiac index obtained on the day of onset in the two groups was related to peak levels of LCI but not to total release of CK. These results suggest that serum levels of LCI reflect the changes in left ventricular function after acute myocardial infarction, regardless of the presence of coronary reperfusion. Thus, serial determinations of LCI in serum facilitate noninvasive assessment of the effects of intracoronary thrombolysis on infarct size.

Adult↗
PubMed1987

Distribution of cardiac myosin isozymes in cardiomyopathy: immunohistochemical and gene analysis.

We characterized cardiac myosin isoforms by immunohistochemical approaches using monoclonal antibodies and demonstrated the existence of a distinctive type of cardiac myosin heavy chain which predominates in the fetal stage but is depressed during postnatal development. Furthermore, we showed that this type of cardiac myosin heavy chain was markedly expressed in patients with dilated cardiomyopathy. The results suggested that the pathologic process involved in dilated cardiomyopathy affects myocardial differentiation by the inhibition of the myosin gene switching that normally occurs during muscle maturation. However, we could not find any polymorphism in myosin gene in our population sample of dilated cardiomyopathy. The pathophysiological role of fetal type cardiac myosin expression in dilated cardiomyopathy will be clarified by the characterization of the myosin near future.

Adult↗
PubMed1986

Isolation and characterization of two isozymes of myosin heavy chain from canine atrium.

To clarify the characteristics of myosin isozymes in the atrium, we fractionated two isoforms of myosin heavy chain (HC), atrial HC alpha (A-HC alpha) and HC beta (A-HC beta), from the canine heart by affinity chromatography, using monoclonal antibodies specific for HC alpha (CMA19) and HC beta (HMC50), respectively, and then compared their peptide composition and enzymatic properties with those of ventricular HC alpha (V-HC alpha) and HC beta (V-HC beta). The reactivity of these isozymes with three monoclonal antibodies revealed that there are at least three different epitopes between A-HC alpha and A-HC beta. Differences in the primary structure of A-HC alpha and A-HC beta were confirmed by one- and two-dimensional gel electrophoretic analyses of these peptides, produced by digestion with alpha-chymotrypsin and cyanogen bromide (CNBr). A-HC alpha and V-HC alpha were indistinguishable proteins, and A-HC beta was also very similar to V-HC beta. Furthermore, there were differences between A-HC alpha and A-HC beta in their Ca2+-activated ATPase activities. The ATPase activity of A-HC beta was lower than that of A-HC alpha and was similar to that of V-HC beta. We concluded that there are two different isozymes of myosin heavy chain in the atrium (A-HC alpha and A-HC beta), as well as in the ventricle (V-HC alpha and V-HC beta), and that A-HC beta is very similar to V-HC beta, the predominant form of ventricular myosin, in its molecular structure and enzymatic activity.

Adenosine Triphosphatases↗
PubMed1986

Distribution of cardiac myosin isozymes in human conduction system. Immunohistochemical study using monoclonal antibodies.

To determine the presence and distribution of cardiac myosin isozymes in the human conduction system, we performed an immunohistochemical study using monoclonal antibodies CMA19 and HMC14, which are specific for myosin heavy chains of human atrial type (alpha-type) and ventricular type (beta-type), respectively. Serial frozen sections of human hearts were obtained from autopsy samples and examined by indirect immunofluorescence. Alpha-type was found in all myofibers of sinus node and atrio-ventricular node, and in 55.2 +/- 10.2% (mean +/- SD, n = 5) of the myofibers of ventricular conduction tissue, which consists of the bundle of His, bundle branches, and the Purkinje network. In contrast, beta-type was found in all myofibers of the atrio-ventricular node and ventricular conduction tissue, whereas almost all myofibers of the sinus node were unlabeled by HMC14. Although the number of ventricular myofibers labeled by CMA19 was small, the labeled myofibers were more numerous in the subepicardial region than in the subendocardial region. These findings show that the gene coding for alpha-type is expressed predominantly in specialized myocardium compared with the adjacent ordinary working myocardium.

Antibodies, Monoclonal↗
PubMed1986

Expression of myosin isozymes during the developmental stage and their redistribution induced by pressure overload.

Cardiac muscles contain at least two isozymes--referred to as alpha(HC alpha) and beta(HC beta)--of the myosin heavy chain. The proportional ratio of these isozymes varies depending upon the developmental stage and the physiological and/or the hormonal milieu of the cell. Using monoclonal antibodies (MoAb) specific for human cardiac HC alpha and HC beta, we have examined the expression of these isozymes in fetal through adult cardiac tissues and investigated whether isozymic redistribution occurs in pressure overloaded human ventricles. We found that although HC alpha was expressed in the atrium from the early embryonic stage, in embryonic ventricular myofibers, only HC beta was expressed without expression of HC alpha, but some myofibers replace HC beta by HC alpha after birth, and these HC alpha containing ventricular myofibers were found to be decreased by pressure overload, which suggested that isozymic redistribution from HC alpha to HC beta also occurred in the ventricles, as well as the atrium. In addition, we also found two subtypes of HC beta (beta 1, beta 2) in the human heart. In the ventricle, both beta 1 and beta 2 was present in all myofibers; in contrast, some myofibers contained beta 1 or beta 2 or both with or without expression of HC alpha in the atrium. beta 1 and beta 2 were distinctive in their expression during the developmental stage, since beta 1 was present in the embryonic heart from the early developmental stage, whereas beta 2 was not present in the early embryonic heart, but began to be expressed in the late embryonic stage.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1986

A case of Takayasu's disease with ruptured carotid aneurysm.

Recently, a number of cases of Takayasu's disease having dilatative or aneurysmal lesions have been reported. Such lesions have come to be considered important manifestations of Takayasu's disease. A case, whose right common carotid artery perforated spontaneously and became a pseudoaneurysm, without any other stenotic lesion is presented with a review of the literature. Surgical treatment was performed successfully.

Adult↗
PubMed1985

Applications of anticardiac myosin monoclonal antibodies in the diagnosis of heart disease.

We have developed anticardiac myosin antibodies, especially monoclonal antibodies, for helping in the diagnosis of heart disease. Our investigations were divided into three research projects. We visualized the distribution of myosin isozymes in human atrial and ventricular myocardium by an immunofluorescence staining method using monoclonal antibodies specific for individual human cardiac myosin isozymes. We also revealed the redistribution of these cardiac myosin isozymes in an overloaded condition. The isozymic pattern of cardiac myosin was changed from the atrial type to the ventricular type in the overloaded atrium. This isozymic redistribution can be considered as physiological adaptive mechanism to meet increased cardiac work during overload. We developed a new method of imaging for myocardial infarction by single photon emission tomography using labelled monoclonal antibody specific for cardiac myosin heavy chain. Specific localization of the labelled antibody was demonstrated in the infarcted area and no accumulation of radioactivity was shown in the bone matrix as observed in 99mTc pyrophosphate images. We developed a sensitive radioimmunoassay of cardiac myosin light chain I (LCI) and demonstrated that peak serum levels of LCI in the patients with acute myocardial infarction correlated well with the left ventricular ejection fraction. Furthermore, LCI release from the infarcted myocardium was not affected by coronary reperfusion due to intracoronary thrombolysis. Thus, serial determinations of serum LCI better quantify the extent of myocardial damage even after coronary reperfusion in acute myocardial infarction.

Antibodies, Monoclonal↗