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Biomedical subjects

N Komiyama

Publications and source records attributed to N Komiyama.

At least 37 records · Page 2Linked to original sources
PubMed1998

Long-term outcome in triple-vessel coronary artery disease in medically treated Japanese patients.

The long-term outcome in 198 patients with triple-vessel disease (TVD) treated medically was investigated. The patients, who underwent coronary angiography between September 1973 and February 1984, had significant (75% or more) stenotic lesions in all three major coronary arteries. The mean follow-up period was 8.4 years. The 5- and 10-year survival rates were 80.7% and 64.2%, respectively. Cardiac death occurred in 73 patients (36.9%) and nonfatal cardiac events developed in 60 patients (30.9%) during follow-up. When cardiac death and nonfatal myocardial infarction (MI) were defined as cardiac events, the annual attrition rate was 4.7%. There was no difference in survival with regard to the presence or absence of MI, the site of infarction, or the presence of total occlusion. In the AP group, however, the survival rate decreased as the number of totally-occluded arteries increased. In the MI group, the survival rate was not altered by the number of totally-occluded arteries, but was affected by the ejection fraction (EF). The 5-year survival rate was better in patients with good left ventricular function (EF > or = 60%) than in those with impaired left ventricular function (EF < 60%), although the 10-year survival rate was similarly low in both groups. Revascularization such as PTCA or CABG might improve the long-term outcome in patients with TVD.

Angina Pectoris↗
PubMed1998

[Value of intravascular ultrasound and angioscopy for diagnosis and prediction of acute coronary syndrome].

The new catheter-based imaging modalities of intravascular ultrasound(IVUS) and angioscopy(AS) can provide with morphologic information within a vessel wall or on an intimal surface of coronary artery, which cannot be clarified by conventional angiography. They could demonstrate some evidences of coronary plaque rupture after the onset of acute coronary syndrome (ACS). IVUS showed an intimal flap and an echolucent area behind it, which might represent a fibrous cap and a lipid core, respectively. Also, AS revealed an intimal tear in various grades. IVUS and AS may contribute to detect a "vulnerable coronary plaque." Both findings of an eccentric fibrofatty plaque, sometimes with an echolucent area, demonstrated by IVUS and a yellow plaque revealed by AS may be valuable for prediction of the plaque rupture preceding ACS.

Acute Disease↗
PubMed1998

[Relationship between evolution of ischemic heart disease and changes in lipid profile].

The relationship between the evolution of ischemic heart disease and changes in lipid profile was investigated in 115 of 11,875 patients underwent coronary angiography (CAG). The 115 patients had no significant stenosis on initial CAG and underwent repeat CAG for several reasons. Changes in lipid profile and other coronary risk factors were compared in 30 patients who developed ischemic cardiac events (Group E) and 85 patients who did not (Group NE). Ischemic cardiac events were defined as ischemic chest symptoms with ST-T changes or appearance of significant angiographic stenosis. At initial CAG, smoking was significantly more common in Group E (23.3% vs 4.7%, p < 0.01) and high-density lipoprotein cholesterol was significantly lower in Group E (42 +/- 11 vs 48 +/- 15 mg/dl, p < 0.05). At repeat CAG, smoking continued to be significantly more common in Group E (26.7% vs 10.6%, p < 0.05), and serum cholesterol (219 +/- 36 vs 193 +/- 34 mg/dl, p < 0.01) and low-density lipoprotein cholesterol (141 +/- 33 vs 115 +/- 29 mg/dl, p < 0.01) were also significantly higher in Group E. Multivariate analysis revealed only the increase of serum cholesterol at repeat CAG was a significant factor in the evolution of coronary artery disease (p = 0.026). Two patients from Group E died of cardiac causes within 1 year after repeat CAG but no patients in Group NE died (6.7% vs 0%, p < 0.05). Increased serum cholesterol level is related to the evolution of ischemic heart disease and cardiac death.

Cholesterol↗
PubMed1997

Redifferentiation of smooth muscle cells after coronary angioplasty determined via myosin heavy chain expression.

BACKGROUND: The pathophysiology of phenotypic modulation of smooth muscle cells (SMCs) involved in restenosis after angioplasty is not well understood. Smooth muscle myosin heavy chain (SM MHC) isoforms (SM1 and SM2) are specific markers for SMC differentiation. In particular, SM2 is useful as a marker of mature SMCs. SMemb is a nonmuscle myosin heavy chain (NM MHC) whose expression is upregulated in immature or activated SMC. METHODS AND RESULTS: To determine SMC phenotypes in neointimal tissues after percutaneous transluminal coronary angioplasty (PTCA), we performed immunohistochemistry on human coronary arteries with antibodies against alpha-SM actin, SM1, SM2, and SMemb. Tissues were obtained from six autopsied patients and from atherectomy specimens from 16 patients who had undergone PTCA. Medial SMCs were positive for alpha-actin, SM1, and SM2. Expression of SM1 and SM2 in the neointima varied with the time after intervention, whereas alpha-actin was constitutively expressed in all cases studied. Neointimal cells at 16 and 20 days after PTCA contained alpha-actin but little or no SM1 or SM2, indicating that these cells modulated their phenotype to the immature state. Neointimal SMCs recovered SM MHC expression, first SM1 and then SM2, by 6 months after PTCA. Increased expression of SMemb was found in the neointima but without apparent relationship to the time after PTCA. CONCLUSIONS: Neointimal SMCs show features of an undifferentiated state, indicated by altered expression of SM MHC, and undergo redifferentiation in a time-dependent manner. The expression of SM MHC isoforms provides insight into the biology of healing after angioplasty and furnishes useful tools for the understanding of the roles of differentiation and phenotypic modulation of SMCs in human vascular lesions.

Aged↗
PubMed1997

Long-term outcome in double-vessel coronary artery disease in Japanese patients.

The long-term (average: 10 years) outcome in 220 patients with double-vessel disease (DVD) treated medically was investigated. The patients underwent coronary angiography between September 1973 and February 1984, and significant (75% or more) stenosis was detected in each of two major coronary arteries. These patients showed relatively good 5-year and 10-year survival rates of 94.5% and 87.4%, respectively. Cardiac death occurred in 31 patients (14.1%) and nonfatal myocardial infarction (MI) developed in 16 patients (7.3%) during follow-up. When these were defined as cardiac events, the annual attrition rate was 3.1%. A comparison of the outcome with regard to the presence or absence of MI revealed worse results for the MI group, but no difference was observed between different sites of infarction. There was also no difference in outcome with regard to the presence or absence of lesions in the left anterior descending artery (LAD). In the MI group, patients with impaired left ventricular function (ejection fraction < or = 40%) had inferior survival to those with good left ventricular function. Thus, DVD associated with good left ventricular function had a relatively good outcome when treated medically, while patients with impaired left ventricular function might benefit from revascularization.

Angioplasty, Balloon, Coronary↗
PubMed1997

Comparison of regional myocardial technetium-99m-MIBI uptake between ECG-gated and ungated SPECT imaging.

UNLABELLED: Technetium-99m-MIBI uptake was compared between ECG-gated and ungated SPECT images in 10 normal subjects and 10 patients with coronary artery disease to investigate the effects of wall motion on regional myocardial uptake. METHODS: Left ventricular ejection fraction (LVEF) and wall motion were evaluated using the first-pass data acquired immediately after injection of 1110 MBq 99mTc-MIBI. A transaxial ungated image was reconstructed with cumulative data during a cardiac cycle. For transaxial gated images, data during a cardiac cycle were divided into eight frames and the first seven frames were used. The lateral/septal ratios for ungated and gated images were obtained using the counts in the ROIs drawn in the lateral and the septal walls. RESULTS: In 10 normal subjects, the lateral/septal ratio for gated increased during end-systole. The mean of the lateral/septal ratio was significantly lower for ungated than for gated (1.025 vs. 1.077, p < 0.05). In patients with septal wall asynergy and a normokinetic lateral wall, the mean of the lateral/septal ratios was significantly lower for ungated than for gated (1.267 vs. 1.325, p < 0.01). CONCLUSION: Ungated SPECT acquisition may underestimate regional myocardial uptake when myocardial wall motion is good, therefore, ECG-gated data should be acquired for accurate assessment of regional myocardial uptake of 99mTc-MIBI.

Adult↗
PubMed1996

Intravascular imaging of serial changes of disease in saphenous vein grafts after coronary artery bypass grafting.

To clarify the structural changes of saphenous vein grafts after coronary artery bypass grafting, intravascular ultrasound and angioscopic images were obtained from 23 grafts in vivo and 5 grafts and 3 new veins in vitro; the images were compared with histologic findings. Intravascular ultrasound demonstrated a single-layered appearance at new veins and all of the angiographically normal grafts within 6 months after surgery. A triple-layered appearance that might be related to the remarkably proliferative and degenerated intima was revealed histologically at 73.3% of the normal sites of grafts between 5 and 10 years after operation. In 83.3% of the stenoses at several years after operation, angioscopy showed yellow atheromatous plaques, often with a friable surface; a heterogeneous, lucent echo pattern was revealed on intravascular ultrasound. Thus intravascular ultrasound and angioscopy may be used to identify the morphologic changes of graft at different points after implantation more precisely than conventional angiography.

Angioscopy↗
PubMed1996

Japanese cedar pollinosis and HLA-DP5.

Japanese cedar pollinosis is a type I allergic disease caused by Japanese cedar (Cryptomeria japonica) pollen. We investigated the association between the disease and HLA class II alleles by HLA-DNA typing using a PCR-SSOP method and found that the frequency of HLA-DP5 (DPA1*02022 and DPB1*0501) was significantly increased in the patients. To investigate whether the HLA-DP5 molecule is directly involved in the pathogenesis of the disease, Japanese cedar pollen antigen (CPAg)-specific T cell lines were established from 3 patients who possessed HLA-DP5 (DPA1*02022/ DPB1*0501). By using these CPAg-specific T cell lines and HLA class II-expressing L-cell transfectants, we found that disease-associated HLA-DP5 restricted T cells specific for CPAg existed in the patients. Furthermore, among 38 synthesized overlapping peptides spanning the entire length of one of the major Japanese cedar pollen allergens, Cry j 1, an immunodominant peptide which induced HLA-DP5 restricted Th2 was identified. These observations suggest that the HLA-DP5 may be involved, at least in part, in the pathogenesis, by helping the IgE antibody production against CPAg.

Adolescent↗
PubMed1996

A hemoglobin-based blood substitute: transplanting a novel allosteric effect of crocodile Hb.

Recombinant DNA technology has enabled the large scale production of human hemoglobin in bacteria and yeast. This has opened up a way to produce a hemoglobin-based blood substitute which could replace conventional blood transfusion in some situations. Using our understanding of the structure-function relationships and evolutionary history of hemoglobin it has been possible to improve the oxygen transport properties of the molecule and solve a number of problems associated with the use of natural hemoglobin as a cell-free blood substitute.

Alligators and Crocodiles↗
PubMed1996

Long-term outcome in single-vessel coronary artery disease in Japanese patients.

We assessed the long-term outcome of medical therapy in 453 patients who underwent coronary angiography in the period from September 1973 to February 1984, and who had a significant stenotic lesion (75% or more stenosis) in a single coronary artery. The mean follow-up period was 9.8 years. The 5- and 10-year survival rates were, respectively, 96.0% and 91.3% in these patients, and these survival rates were comparable to the cumulative survival rates in the age-matched healthy male controls determined on the basis of overall death. Cardiac death occurred in 35/453 patients (7.7%) with single-vessel disease (SVD), and non-fatal myocardial infarction occurred in 17 patients (3.8%) during the follow-up period. The incidence of cardiac events, which was defined as cardiac death and nonfatal myocardial infarction, was as low as 1.2% per year. The survival rates were compared in terms of the presence or absence of myocardial infarction, the type of the coronary artery with stenosis, and proximal versus distal location of the stenotic lesion in the left anterior descending artery (LAD). The survival rates were similarly high in both assessed groups, with no significant differences. Patients with SVD treated medically had a good prognosis, except for those patients with decreased left ventricular function (ejection fraction < or = 40%). These factors should be taken into consideration when selecting therapies for patients with SVD.

Case-Control Studies↗
PubMed1996

[Long-term recovery of regional wall motion in patients with medically treated anterior myocardial infarction: quantitative assessment of the post-infarction left ventriculograms].

The effect of medical treatment without reperfusion therapy on the long-term recovery of regional wall motion was evaluated retrospectively in 28 patients with transmural acute anterior myocardial infarction who had coronary angiography and left ventriculography at 1-6 months after the onset of the episode and were followed for a mean of 65 months. In all patients, initial coronary angiography revealed significant stenosis in only the left anterior descending artery (LAD). All patients were treated medically without reperfusion therapy (such as thrombolytic therapy, angioplasty, or bypass grafting). The regional wall motion in the LAD territory was measured by the centerline method using the right anterior oblique projection. Long-term improvement in anterior wall motion is unlikely in patients with patent LAD or underdeveloped collaterals to the LAD (38%). However, subsequent anterior wall motion frequently improved among patients with severely stenotic or occluded LAD (63%) and well-developed collaterals (73%). Therefore, the anterior wall motion of some LAD-related infarctions improves spontaneously, the extent of coronary collaterals is an important determinant of long-term improvement, and the improvement in wall motion is completed within the early period of acute anterior infarction in patients with patent LAD.

Angiocardiography↗
PubMed1995

Comparison of long-term efficacy of medical treatment versus percutaneous transluminal coronary angioplasty (PTCA) in single-vessel disease.

The long-term outcome of PTCA and medical therapy were compared in patients with SVD. All patients were confirmed to have > or - 75% stenosis of a major coronary artery by coronary arteriogram. The 5-year survival rates were 96.0% for medical therapy and 98.9% for successful angioplasty. Both therapies achieved an equally good long-term outcome for SVD. The incidence of nonfatal cardiac events during follow-up was higher in patients treated by PTCA than in those on medical therapy, but there was no difference between the two groups in the incidence of nonfatal MI at 5 years (2.5% vs 1.8%). The most common cardiac event in patients undergoing successful PTCA was repeat intervention associated with restenosis. In view of the long-term efficacy of PTCA, the high restenosis rate remains an important problem and it is necessary to elucidate the causes of restenosis and develop countermeasures as soon as possible.

Adult↗
PubMed1995

Comparison of long-term efficacy of medical treatment versus coronary artery bypass grafting (CABG) in multivessel coronary artery disease.

The long-term results of medical therapy and coronary artery bypass grafting (CABG) were compared in patients with multivessel disease. All patients were confirmed to have > or = 75% luminal narrowing of major coronary arteries by coronary arteriogram. When multivessel disease was stratified into double- and triple- vessel disease, the outcomes varied. In triple-vessel disease, the outcome with CABG was good, but the outcome was unfavorable in those employing medical therapy, particularly in patients with decreased left ventricular (LV) function. In patients with double-vessel disease with good LV function, the long-term results with medical therapy were just as favorable as those with CABG. However, double-vessel disease complicated by reduced LV function (ejection faction < or = 40%) had a clearly less favorable outcome when treated with medical therapy than with CABG. Thus, it is important for patients with multivessel disease to undergo revascularization if indicated, to improve their prognosis. On the other hand, the incidence of cardiac events arising from vein graft occlusions tended to increase in CABG patients after 5 years or more following surgery.

Aged↗
PubMed1994

cDNA cloning and expression of Cry j II the second major allergen of Japanese cedar pollen.

We have isolated and sequenced a cDNA clone coding for Cry j II, the second major allergen of Japanese cedar (Cryptomeria japonica) pollen. A 1.7-kilobase cDNA clone contained an open reading frame coding for a 514-amino acid protein, including a putative signal peptide of 54 amino acid and three potential glycosylation sites. The deduced amino acid sequence of the Cry j II shows significant identities to those of the polygalacturonases associated with fruit-ripening in tomato (40%) and avocado (43%) and found in pollen of maize (34%). Cry j II cDNA product expressed in E. coli was recognized by human IgE from patients suffering from cedar pollinosis, suggesting that recombinant Cry j II might be used as an allergen for the clinical diagnosis of cedar pollinosis.

Amino Acid Sequence↗
PubMed1994

Cloning and sequencing of cDNA coding for Cry j I, a major allergen of Japanese cedar pollen.

cDNA clones coding for Cry j I, a major allergen of the Japanese cedar (Cryptomeria japonica) pollen, have been isolated. Two of the clones were sequenced and found to code for a putative 21-residue signal peptide and a 353-residue mature protein with a derived molecular weight of 38.5 KDa. Five possible N-linked glycosylation sites were found in the sequence. Comparison of the nucleotide sequences of the two clones revealed sixteen nucleotide differences and these led to five amino acid exchanges in the mature allergen, indicating that an isoform of the Cry j I molecule exists. The deduced amino acid sequence of the Cry j I shows 46-48% identities with those of the Amb a I family and Amb a II, the major allergens of short ragweed. These findings should facilitate study of the structure-function relationship between the allergen and the immunocompetent cells.

Allergens↗