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M Sekiguchi

Publications and source records attributed to M Sekiguchi.

At least 505 records · Page 28Linked to original sources
PubMed1986

[Prognosis of dilated cardiomyopathy: an integrated study using a prognostic index].

A ten year follow-up study of 111 patients with dilated cardiomyopathy (DCM) was conducted. The five year survival rate after onset of subjective symptoms was 53%; the ten year survival rate, 22%. To evaluate the prognosis of DCM, the cardiothoracic ratio (CTR), ECG, hemodynamics, and histopathological contractility failure index (HCFI) which we constructed via a right ventricular endomyocardial biopsy, were compared. Patients having malignant arrhythmias with mildly impaired cardiac status, mild cardiomegaly and low HCFI were more prone to sudden death. In patients with progressively deteriorating cardiac status, refractory cardiomegaly, supraventricular arrhythmias, left axis deviation, prolongation of QRS interval, low voltage and high HCFI, the cause of death was more likely refractory heart failure. A prognostic index of DCM was then constructed through cardiac status, CTR, ECG, hemodynamics and HCFI. The mortality rate of the group with a prognostic index of seven points or below was 5.0%; the group with eight points or above was 82.1%. The prognostic index of DCM was thus shown to be a useful prognostic indicator.

Adult↗
PubMed1985

Purification and structure of the intact Ada regulatory protein of Escherichia coli K12, O6-methylguanine-DNA methyltransferase.

The ada gene of Escherichia coli K12, the regulatory gene for the adaptive response of bacteria to alkylating agents, was cloned and placed under the control of the lac regulatory region on a multicopy runaway plasmid, thereby yielding a hybrid plasmid pYN3059. Ada protein with a molecular weight of about 38,000 was overproduced when cells harboring pYN3059 were incubated at 42 degrees C in the presence of a lac inducer, isopropyl-beta-D-thiogalactoside. Taking advantage of overproduction of Ada protein, we purified the protein to apparent physical homogeneity. The purified 38,000-dalton Ada protein transferred the methyl group from the O6-methylguanine residue of alkylated DNA to the Ada protein, per se. Although the Ada protein was degraded to smaller polypeptides when crude extracts or partially purified preparations were incubated in a high ionic-strength buffer at neutral pH, the purified Ada protein remained stable under the same conditions, indicating that the Ada protein may not undergo autodegradation. An amino-terminal sequence and total amino acid composition of the purified Ada protein were in accord with nucleotide sequence of the ada gene, determined by the dideoxy method using M13 phage. It was deduced that Ada protein comprises 354 amino acids and its molecular weight is 39,385. The promoter for the ada gene was determined by S1 nuclease mapping.

Amino Acid Sequence↗
PubMed1985

Stimulation of the UvrABC enzyme-catalyzed repair reactions by the UvrD protein (DNA helicase II).

An in vitro assay system was constructed using highly purified preparations of UvrA, UvrB, UvrC, UvrD proteins and DNA polymerase I, the objective being to analyse the role of UvrD protein in excision repair of UV-induced DNA damage. UvrABC enzyme-initiated repair synthesis was greatly enhanced by the addition of UvrD protein to the reaction mixture. Further analysis revealed that UvrD protein stimulated introduction of strand breaks in irradiated DNA by UvrABC enzyme but had no effect on the DNA polymerase I reaction. Thus, the site of action of UvrD protein is probably at the incision-excision step and not in later steps in excision repair.

Adenosine Triphosphatases↗
PubMed1985

Molecular cloning and characterization of the alkB gene of Escherichia coli.

Using methods of in vitro recombination we constructed hybrid plasmids that can suppress the increased methylmethane sulfonate sensitivity caused by alkB mutation. Since the cloned DNA fragment was mapped at 47 min on the Escherichia coli K12 genetic map, an area where the alkB gene is located, we concluded that the cloned DNA fragment contains the alkB gene itself but not other genes that suppress alkB mutation. Specific labeling of plasmid-encoded proteins by the maxicell method revealed that the alkB codes for a polypeptide with a molecular weight of about 27,000. Introduction of a small deletion into the alkB region of the bacterial chromosome resulted in inactivation of both the alkB and ada genes, thereby suggesting that the two genes are adjacent on the E. coli chromosome.

Alkylation↗
PubMed1985

Prognosis of dilated cardiomyopathy. An integrated analysis including endomyocardial biopsy findings.

A long-term prognostic study of up to 15 years of dilated cardiomyopathy (DCM) was carried out in 65 cases. The 5-year survival rate after the onset of subjective symptoms was 40%, and the 10-year survival rate 22%. To evaluate the prognostic factor of DCM, the cardiothoracic ratio (CTR), ECG, hemodynamics, and histopathological contractility failure index (HCFI), which we constructed through right ventricular endomyocardial biopsy, were compared. Patients having malignant arrhythmias, such as short runs or multifocal ventricular premature beats with mild impaired cardiac status, mild cardiomegaly, and low HCFI, were more prone to sudden death. In patients with progressively deteriorating cardiac status, refractory cardiomegaly, supraventricular arrhythmias, left axis deviation, prolongation of QRS interval, low voltage, and high HCFI, the cause of death is more likely to be refractory heart failure.

Adult↗
PubMed1985

Left ventricular endomyocardial biopsy findings in patients with essential hypertension and hypertrophic cardiomyopathy with special reference to the incidence of bizarre myocardial hypertrophy with disorganization and biopsy score.

To investigate whether bizarre myocardial hypertrophy with disorganization (BMHD) is characteristic of hypertrophic cardiomyopathy (HCM), the histopathology of the biopsied left ventricular myocardium in 18 patients with essential hypertension (HT) and 14 patients with HCM was studied. A "biopsy score" was devised for a more quantitative evaluation of the BMHD and a comparative study on the biopsy score of the left ventricular biopsied specimen was also performed. The patients with HT were judged to be in stages I or II of the WHO criteria and had a history of hypertension of more than 5 years. The BMHD was defined as myocardial cells showing hypertrophy, disorganization, and bizarre nuclei. "Disorganization" of myocardial cells was distinguished both by the terminology and histopathological characteristics from "disarrangement" of myocardial cells. The biopsy score employed four factors and was determined according to the following formula: Biopsy score = hypertrophy of myocardial cells + (disorganization of myocardial cells) x 2 + bizarre nuclei + whorling of muscle bundles. Both the hypertrophy and the disorganization of myocardial cells were regarded as essential conditions indicating the presence of BMHD. The BMHD was found in 2 of 18 patients with HT (11%) and in 10 of 14 patients with HCM (71%) in the left ventricular biopsied specimens (P less than 0.005). However, "disarrangement" of myocardial cells was found in 13 of 18 HT patients (72%) and in 10 of 14 HCM patients (71%) in the left ventricular biopsied specimens, showing no difference between the two groups. The biopsy score in HCM patients was larger than that found in HT patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1985

Double nuclei in endomyocardial biopsy: a comparative study of the incidence in myocarditis and chronic right ventricular overloading.

The incidence of double nuclei in myocarditis and in cases with right ventricular overloading (CRVO) was histopathologically assessed in a minimum of 100 longitudinally cut myocytes in specimens obtained at right ventricular endomyocardial biopsy. In myocarditis, the incidence of double nuclei was shown to be 5.8 +/- 1.8 and in CRVO and in normal heart tissue it was seen in 3.0 +/- 0.8 and 3.2 +/- 0.9% (m +/- S.D.), respectively, of the population of myocytes. It is concluded that double nuclei result from either the activity or the reparative process of myocarditis and that it is not the expression of chronic right ventricular overloading. It is suggested that quantitative assessment of the frequency of double nuclei is an useful method in the interpretation of myocardial biopsy.

Biopsy↗
PubMed1985

Recent trends in cardiac sarcoidosis research in Japan.

Our recent survey of the Japanese literature, actual case experience, and previous studies revealed the following results. Fifty-three cases were reported in which the main cause of death in sarcoidosis was congestive heart failure (11 of 17 cases, 64.7%) and not sudden death as was previously believed. ECG analysis revealed that third degree AV block, bundle branch block, and ventricular arrhythmias were the most frequent findings indicating the presence of cardiac sarcoidosis. It was recognized that in the Japanese population fatal myocardial sarcoidosis or clinical diagnosed cardiac sarcoidosis occurred most frequently in females over the age of 40 years. It is suggested that myocardial changes progress independently of granulomatous changes. This is due to the detection of a high incidence of basal lamina layering of myocardial capillaries (14 of 18 cases, 77.8%) and is considered to play a significant role in the progression of this disease. Radionuclide studies showed that thallium scintigraphy or technetium ventriculography were positive in those cases where ECG abnormalities are prominent, indicating the presence of myocardial disease. Previous therapeutic studies of cardiac sarcoidosis have shown a decrease in the incidence of sudden death; death due to congestive heart failure occurred more frequently despite pacemaker implantation. Control of congestive heart failure is thus regarded as the most important aspect of improved treatment and prognosis.

Adolescent↗
PubMed1985

Histopathologic and ultrastructural observations of acute and convalescent myocarditis: a serial endomyocardial biopsy study.

Serial endomyocardial biopsy findings were analyzed in ten cases with acute myocarditis of possible viral origin. The histopathologic findings were analyzed at the acute (0-10 days after the onset), subacute (11-21 days), and convalescent stages (22-167 days). The incidence and severity of various cardiac myocyte and interstitial changes were compared at each stage of the disease. The time-course changes of the histopathologic findings in acute myocarditis were as follows. At the acute stage, we observed: interstitial cell infiltration composed of fibroblasts, macrophages, and lymphocytes, fragmentation of the muscle bundles, myocytolytic changes, swelling and scarcity of the cytoplasm and swelling of nuclei, variation in size of the myocytes, disarrangement of the muscle bundles, interstitial edema, increased glycogen deposition in the myocytes, abnormal branching of the myocytes, and interstitial fibrosis. At the convalescent stage, most of the above findings could still be seen except for myocytolytic changes, swelling of myocytes, and interstitial edema. At the subacute and convalescent stages, an increase in abnormal branching and in double nuclei in the myocytes and nuclear degeneration became observable. A further control study comparing the changes at the convalescent stage of myocarditis and the myocardial changes in cases with chronic right ventricular overload in 58 cases revealed that in the former fragmentation of the muscle bundles, abnormal branching, size variation, glycogen deposition, and large mononuclear cell infiltrations were significantly more frequent. Ultrastructural observation of the myocytes revealed that they have a great potentiality for regeneration; myocytes showing severe myocytolytic changes may recover to regain an architecture of almost normal appearance.

Acute Disease↗
PubMed1985

A comparative ultrastructural study on the nature of interstitial cell constituents in idiopathic myocarditis and myocardial infarction.

In order to observe the characteristics of interstitial cellular proliferation in cases with myocarditis of possible viral origin, a systematic ultrastructural analysis of the cell components in the interstitium was made employing endomyocardial biopsy at the acute (0-10 days after onset), subacute (11-25 days), and convalescent stages (26-167 days) of the disease in ten cases. For comparison, myocardial specimens from cases with myocardial infarction were taken from early autopsy cases or from tissue obtained during surgery. The dominant interstitial cells observed in the acute stage of myocarditis were fibroblasts (38.3% +/- 17.5%, mean +/- SD), macrophages (23.3% +/- 12.1%), and lymphocytes (18.0% +/- 18.1%); at the convalescent stage, fibrocytes (44.6% +/- 20.2%) and fibroblasts (22.5% +/- 8.0%) were commonly seen. In myocardial infarction, the dominant cells were macrophages (35.0% +/- 16.0%) and neutrophils (26.0% +/- 13.9%) at the acute stage, and lymphocytes (30.0% +/- 17.8%), plasma cells (27.1% +/- 20.0%), and macrophages (26.4% +/- 11.4%) at the late stage. Thus, some differences between the two diseases could be recognized.

Acute Disease↗
PubMed1985

A clinicopathologic study on a cause of idiopathic cardiomyopathy and arrhythmia and conduction disturbance employing endomyocardial biopsy.

A comparative study of right ventricular histopathologic findings and clinical profiles in 174 cases with hypertrophic cardiomyopathy (HCM), 145 cases with dilated cardiomyopathy (DCM), and 241 cases with idiopathic arrhythmia and/or conduction disturbance with significant myocardial pathology [Electric disturbance type of cardiomyopathy (ECM)], totaling 560 cases, was made in order to clarify the role of viral myocarditis in these conditions. Postmyocarditis change (PMC) was defined by assessing serial biopsy findings in nine cases with acute myocarditis. The PMC was observed in three cases with HCM (1.7%), 22 with DCM (15%), and 21 with ECM (8.7%). The incidence of PMC was significantly higher in DCM and ECM than in HCM (P less than 0.001). The typical pattern of onset of acute myocarditis, i.e., high fever, upper respiratory infection, and gastrointestinal symptoms preceding cardiac symptoms within 10 days, was recognized in one case with HCM, eight with DCM, and 6 of 123 cases with ECM. The incidence was higher in DCM and ECM than in HCM (P less than 0.05). Of 46 cases with PMC, 12 (26%) showed this pattern, on the other hand only 3 of 377 cases (0.8%) without PMC did so (P less than 0.0001). Familial occurrence was not found in any of the 46 cases with PMC but was found in 38 of the 377 cases without PMC (P less than 0.01). This study indicates that viral myocarditis may often be the causative agent of idiopathic cardiomyopathy, especially DCM and ECM. It is also noticed that familial occurrence of the cases with PMC was never seen.

Acute Disease↗
PubMed1985

Hemodynamic studies and response to a combined therapy of nitroglycerin ointment and dopamine in patients with acute myocarditis.

Left ventricular performance was assessed in ten patients with acute myocarditis during the acute stage (within the first 3 days after the onset of cardiac symptoms) and during the convalescent phase (3-5 weeks later). In nine, the diagnosis was confirmed by endomyocardial biopsy during the acute stage, when left ventricular function was markedly reduced, i.e., cardiac index 1.53 +/- 0.33 l/min/m2 (mean +/- SD), left ventricular stroke work index 14.1 +/- 3.9 g/beat/m2, pulmonary capillary pressure 25.9 +/- 4.3 mm Hg, and systemic vascular resistance 27.9 +/- 9.4 R units. During convalescence, seven patients improved clinically with normal cardiac function and in three it remained impaired. Cardiovascular response to nitroglycerin ointment in three patients and a combination of dopamine and nitroglycerin ointment in five were compared. Nitroglycerin ointment reduced pulmonary capillary pressure by an average of 28.5% (P less than 0.05) and systemic vascular resistance by 26.8%, while the cardiac index increased by 34.1% (P less than 0.05) and left ventricular stroke work index by 30.3% (P less than 0.01). The combined therapy was more effective, with a reduction of pulmonary capillary pressure by 30.4% (P less than 0.05) and systemic vascular resistance by 27.5% (P less than 0.05), accompanying an increase in cardiac index by 53.5% (P less than 0.005) and left ventricular stroke work index by 63.5% (P less than 0.01), with little change in the double products. This study suggests that serial hemodynamic monitoring accurately evaluates cardiac function, selection of appropriate therapy, and the hemodynamic effects of treatment in patients with acute myocarditis.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1985

Long follow-up study in patients with prior myocarditis by radionuclide methods.

Ten patients with previous myocarditis were evaluated to determine cardiac conditions by T1-201 myocardial perfusion imaging and stress radionuclide ventriculography during the follow-up of 18-102 (average 56) months; the results were compared with those from ten sex- and age-matched controls. Exercise capacity by supine bicycle ergometer was reduced in patients with myocarditis. Their resting left ventricular ejection fraction (LVEF) was 57.5% +/- 3.9%, similar to that of controls. LVEF response to stress in myocarditis was abnormal with an increment of end-systolic volume, while in the controls LVEF increased significantly during stress. Seven of the eight patients with an abnormal ejection fraction response had constant T1-201 perfusion defects. This study indicates that latent left ventricular dysfunction is present in patients with prior myocarditis and that nuclear study is useful for long-term follow-up.

Adult↗