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M Nobuyoshi

Publications and source records attributed to M Nobuyoshi.

At least 73 records · Page 4Linked to original sources
PubMed1994

A randomized comparison of coronary-stent placement and balloon angioplasty in the treatment of coronary artery disease. Stent Restenosis Study Investigators.

BACKGROUND: Coronary-stent placement is a new technique in which a balloon-expandable, stainless-steel, slotted tube is implanted at the site of a coronary stenosis. The purpose of this study was to compare the effects of stent placement and standard balloon angioplasty on angiographically detected restenosis and clinical outcomes. METHODS: We randomly assigned 410 patients with symptomatic coronary disease to elective placement of a Palmaz-Schatz stent or to standard balloon angioplasty. Coronary angiography was performed at base line, immediately after the procedure, and six months later. RESULTS: The patients who underwent stenting had a higher rate of procedural success than those who underwent standard balloon angioplasty (96.1 percent vs. 89.6 percent, P = 0.011), a larger immediate increase in the diameter of the lumen (1.72 +/- 0.46 vs. 1.23 +/- 0.48 mm, P < 0.001), and a larger luminal diameter immediately after the procedure (2.49 +/- 0.43 vs. 1.99 +/- 0.47 mm, P < 0.001). At six months, the patients with stented lesions continued to have a larger luminal diameter (1.74 +/- 0.60 vs. 1.56 +/- 0.65 mm, P = 0.007) and a lower rate of restenosis (31.6 percent vs. 42.1 percent, P = 0.046) than those treated with balloon angioplasty. There were no coronary events (death; myocardial infarction; coronary-artery bypass surgery; vessel closure, including stent thrombosis; or repeated angioplasty) in 80.5 percent of the patients in the stent group and 76.2 percent of those in the angioplasty group (P = 0.16). Revascularization of the original target lesion because of recurrent myocardial ischemia was performed less frequently in the stent group than in the angioplasty group (10.2 percent vs. 15.4 percent, P = 0.06). CONCLUSIONS: In selected patients, placement of an intracoronary stent, as compared with balloon angioplasty, results in an improved rate of procedural success, a lower rate of angiographically detected restenosis, a similar rate of clinical events after six months, and a less frequent need for revascularization of the original coronary lesion.

Angioplasty, Balloon, Coronary↗
PubMed1994

Coronary atherosclerotic smooth muscle cells overexpress human parathyroid hormone-related peptides.

Parathyroid hormone-related peptide (PTHrP) was originally characterized as a tumor product responsible for hypercalcemia of malignancy and was subsequently found to be produced in many normal tissues. PTHrP is now suggested to play a critical role in the local modulation of vascular smooth muscle function. To elucidate the involvement of PTHrP in coronary atherosclerosis, we immunohistochemically examined coronary arteries obtained from 76 patients with various grades of atherosclerosis and compared the correlation between PTHrP staining and the percent stenosis. Smooth muscle cells at sites of coronary atherosclerosis overexpressed PTHrP, while cells from normal coronary arteries did not. The in situ hybridization using PTHrP riboprobe has also proven the overexpression of PTHrPmRNA in the affected lesions following atherectomy. The intensity of PTHrP expression by smooth muscle cells was significantly correlated with the degree of coronary artery stenosis. Coronary arterial PTHrP overexpression is closely related to the severity and/or progression of coronary atherosclerosis.

Adult↗
PubMed1994

Long-term clinical and angiographic follow-up after placement of Palmaz-Schatz coronary stent: a single center experience.

The purpose of this study is to evaluate long-term clinical and angiographic follow-up results after placement of the Palmaz-Schatz stent and angiographic follow-up results of repeat interventions for stent restenosis. From June 1990 to September 1993, the Palmaz-Schatz stent was placed in 411 patients, 427 lesions. Follow-up angiography was performed in 307 lesions at 3-6 months and in 189 lesions at 1 year. Palmaz-Schatz stent implantation resulted in 97.2% procedure success and 94.6% clinical success. Stent thrombosis was observed in 2.2%. Angiographic restenosis rate was 16.3% at 3-6 months study. At 1 year study, "new" restenosis occurred only in 2.3%. Minimal lumen diameter did not change between 6 months and 1 year (2.32 +/- 0.51 mm vs 2.30 +/- 0.54 mm). With the mean follow-up interval of 22 +/- 9 months, cardiac event-free survival was achieved in 74.3%. Among 50 lesions with restenosis, stent restenosis occurred diffusely in 15 lesions (30%), focally inside the stent in 22 lesions (44%) and focally at the stent border in 13 lesions (26%). Repeat interventions were performed in 35 lesions. Restenosis at 3 months after repeat intervention was demonstrated in 9 (32.1%) out of 28 lesions restudied. Restenosis rate after repeat intervention for diffuse stent restenosis was significantly higher than that for focal in-stent restenosis (75% vs 7.7%). Palmaz-Schatz stent implantation was associated with a high initial success rate and a low late restenosis rate. Luminal renarrowing did not occur beyond 6 months up to 1 year.

Coronary Angiography↗
PubMed1994

Randomized comparison of rescue angioplasty with conservative management of patients with early failure of thrombolysis for acute anterior myocardial infarction.

BACKGROUND: When used in the setting of acute myocardial infarction, intravenous thrombolytic agents fail to achieve early infarct artery patency in 15% to 50% of patients. We tested the hypothesis that immediate balloon angioplasty applied to patients with failed early reperfusion would improve left ventricular function and clinical outcome at 30 days compared with conservative management alone. METHODS AND RESULTS: One hundred fifty-one patients with first anterior wall infarction treated with any accepted intravenous thrombolytic regimen and angiographically demonstrated to have an occluded infarct vessel within 8 hours of chest pain onset were randomized to aspirin, heparin, and coronary vasodilators (conservative therapy) or to this therapy and balloon angioplasty supplemented by further thrombolytic therapy as needed. Left ventricular function was assessed using multiple-gated equilibrium radionuclide technique to determine ejection fraction, and adverse clinical outcome was assessed evaluating death, ventricular tachycardia, and class III or IV heart failure at 30 days. Seventy-three patients were randomized to conservative therapy and 78 to angioplasty. The two groups were well balanced for patient age (59 +/- 11 years), sex (82% were male), and time to randomization (4.5 +/- 1.9 hours). Angioplasty was technically successful in 72 of 78 randomized patients (92%). Two patients randomized to conservative therapy crossed over to angioplasty within 72 hours. Resting 30-day ejection fraction was 40 +/- 11% in the angioplasty group and 39 +/- 12% in the conservative group (P = .49), but ejection fraction with exercise was 43 +/- 15% and 38 +/- 13% for the angioplasty and conservatively treated groups, respectively (P = .04). Adverse clinical outcomes included death in 5% and 10% (P = .18), severe heart failure in 1% and 7% (P = .11), and either death or severe heart failure in 6% and 17% (P = .05) of the angioplasty and conservatively managed groups, respectively. CONCLUSIONS: When applied to patients with first anterior infarction, rescue angioplasty appears to be useful in the prevention of death or severe heart failure, with improvement in exercise, but not resting, ejection fraction. This strategy deserves further study and highlights the potential advantage of early mechanical restoration of infarct vessel patency when thrombolytic therapy has failed.

Aged↗
PubMed1993

Identification of a single-stranded DNA-binding protein that interacts with an S1 nuclease-sensitive region in the platelet-derived growth factor A-chain gene promoter.

We previously observed that transcription of the platelet-derived growth factor (PDGF) A-chain gene is enhanced in cells stimulated by PDGF through a serum response element (SRE) in its 5'-flanking sequence. We now show that the region of the SRE is sensitive to S1 nuclease in vitro. We also identify a single-stranded DNA-binding protein in HeLa cell nuclear extracts that binds to the noncoding strand of the PDGF A-chain SRE but not to its double-stranded counterpart or to the single-stranded coding sequence. Competition assays using oligonucleotides with sequence-specific mutations that diminished or eliminated detectable complex formation were used to establish the specificity of this protein/DNA interaction. Remarkably, the sequence-specific single-stranded binding protein binds to this region only when it is highly supercoiled. The data suggest that the single-stranded DNA-binding protein specifically interacts with a highly supercoiled region of the PDGF A-chain promoter and that this interaction may have a role in the transcriptional regulation of this gene.

Base Sequence↗
PubMed1993

Serial angiographic follow-up after Palmaz-Schatz stent implantation: comparison with conventional balloon angioplasty.

OBJECTIVES: Serial angiographic follow-up study was designed to evaluate the temporal mode of lumen diameter changes after Palmaz-Schatz stent implantation, and the results were compared with those from a cohort of patients undergoing balloon angioplasty. BACKGROUND: Restenosis remains a major limitation of balloon angioplasty. The Palmaz-Schatz balloon expandable coronary stent is now under clinical investigation to evaluate its efficacy in preventing restenosis. METHODS: Serial angiographic follow-up study was performed the day after stent implantation and at 1, 3 and 6 months after the procedure. The stent group consisted of 96 patients who had 97 lesions with a single stent. A cohort of 179 patients with 192 lesions were selected as the balloon group by the criteria of final balloon size > or = 3 mm and lesion length < 20 mm. RESULTS: A significantly larger lumen diameter was obtained immediately after stent implantation (2.9 +/- 0.4 mm [mean +/- SD] in the stent group vs. 2.1 +/- 0.5 mm in the balloon group, p < 0.001). At 3 to 6 months of follow-up, a significantly larger lumen diameter was maintained in the stent group (2.2 +/- 0.6 vs. 1.5 +/- 0.7 mm, p < 0.001). The late restenosis rate according to a binary definition was significantly lower in the stent group (13% vs. 39%, p < 0.001). Stenosis exacerbation, frequently observed within 24 h after balloon angioplasty, was not found after stenting. Between the next day and 1 month, regression was dominant in the balloon group, whereas progression of stenosis was observed in the stent group. The greatest tendency to restenosis was observed in both groups between 1 and 3 months after the procedure. Between 3 and 6 months, significantly greater diameter loss was found in the stent group. CONCLUSIONS: The Palmaz-Schatz stent was effective in reducing the restenosis rate in this highly selected cohort of patients. Reduction in restenosis rate was dependent on a larger lumen obtained immediately. Late loss of diameter was significantly greater after stenting. The restenosis rate after stenting should be evaluated by follow-up angiography at 6 months rather than at 3 months, which is adequate after conventional balloon angioplasty.

Adult↗
PubMed1993

Generalized model of restenosis after conventional balloon angioplasty, stenting and directional atherectomy.

OBJECTIVES: This study was designed to extend the results of a quantitative model originally developed for restenosis after stenting or atherectomy to include restenosis after conventional balloon angioplasty. BACKGROUND: We have previously described a continuous regression model that explains late (6-month) lumen narrowing as the difference between the immediate gain and the subsequent normally distributed late loss in lumen diameter after Palmaz-Schatz stenting or directional atherectomy. METHODS: Lumen diameter was measured immediately before and after coronary intervention on 524 consecutive lesions including those treated by Palmaz-Schatz stenting (102), directional atherectomy (134) and conventional balloon angioplasty (288). Of these lesions, 475 (91%) underwent follow-up angiography 3 to 6 months after treatment. The immediate increase in lumen diameter produced by the intervention (immediate gain) and the subsequent reduction in lumen diameter between the time of intervention to follow-up angiography (late loss) were examined. Association between demographic or angiographic variables and continuous measures of restenosis (late lumen diameter or late percent stenosis) was tested with linear regression techniques; a traditional binary measure of restenosis (late diameter stenosis > or = 50%) was evaluated with logistic regression analysis. RESULTS: Regression models relating late lumen diameter to the immediate lumen result were successfully fitted to all segments studied. According to these models, three indexes of restenosis (late lumen diameter, late percent stenosis and binary restenosis) were found to depend solely on the immediate lumen diameter after the procedure and the immediate residual percent stenosis, but not on the specific intervention used. Moreover, the late loss in lumen diameter was found to vary directly with the immediate gain provided by an intervention, and the "loss index" (a measure that corrects for differences in immediate gain) was uniform among all three interventions. CONCLUSIONS: The quantitative model originally developed for restenosis after stenting or atherectomy may thus be generalized to include conventional balloon angioplasty. It shows that the apparent differences in restenosis among the three interventions studied are due solely to differences in the immediate result provided and not to differences in the behavior of subsequent late loss. Moreover, although the late loss in lumen diameter was found to correlate with differences in the immediate gain provided by an intervention, the "loss index" (a measure that corrects for differences in acute gain) was uniform across all three interventions. It is thus the immediate result (and not the procedure used to obtain that result) that determines late outcome after coronary intervention.

Aged↗
PubMed1993

Expressions of DNA topoisomerase I and II gene and the genes possibly related to drug resistance in human myeloma cells.

In order to clarify the mechanism of drug resistance in human myeloma cells, we investigated the expressions of DNA topoisomerase I and topoisomerase II gene and the genes possibly related to drug resistance; multi-drug resistant gene 1 (MDR-1), glutathione S-transferase class pi gene (GST-pi), by Northern blotting. Myeloma cells in eight of 15 cases prior to chemotherapy expressed topoisomerase I mRNA considerably, while the expression of topoisomerase II mRNA was detected weakly in only one of 16 myeloma patients. There was not any correlation between expression of topoisomerase I mRNA and clinical drug resistance. Significant expression of MDR-1 mRNA and P-glycoprotein was not detected in 25 cases of multiple myeloma prior to chemotherapy and even after several courses of VAD (vincristine, adriamycin and dexamethasone) therapy by Northern blotting and immunostaining using monoclonal anti-P-glycoprotein antibody (MRK-16), respectively. On the other hand, 16 of 21 myeloma cases showed significant expression of GST-pi protein and GST-pi mRNA with the various strengths, but there was no apparent correlation between GST-pi mRNA expression and clinical response. Therefore these data suggest that expression of the genes we tested may not determine the level of drug resistance in multiple myeloma, but lower or no significant expression of topoisomerase II mRNA in most myeloma cells indicates the possibility that topoisomerase II inhibitors such as VP-16 and topoisomerase II-mediated cytotoxic drugs such as adriamycin, are not so effective for the treatment of multiple myeloma.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1993

Lesion-to-lesion independence of restenosis after treatment by conventional angioplasty, stenting, or directional atherectomy. Validation of lesion-based restenosis analysis.

BACKGROUND: Since many restenosis trials include patients in whom more than one lesion is treated, analysis of the angiographic data on a "per lesion" basis might be confounded by potential correlations of restenosis among multiple treated lesions within each patient. The goals of this study were: 1) to determine whether there was any correlation in the rate of restenosis among multiple lesions that underwent conventional angioplasty, stenting, or directional atherectomy within the same patient and 2) to determine whether lesions treated in a multilesion intervention experience a different magnitude of restenosis than lesions undergoing single-lesion procedures. METHODS AND RESULTS: Of 441 patients treated by Palmaz-Schatz stenting (n = 114), directional atherectomy (n = 100), or conventional balloon angioplasty (n = 227), 67 underwent multilesion procedures involving treatment of 146 lesions. A general linear model with intraclass correlation (GLIMIC) was used to calculate the coefficient of correlation (rho) of the change in the measured minimum luminal diameter (late loss) from the time of the initial procedure to 6-month angiogram among the multiple lesions within the same patient for all 441 patients. This showed no correlation among multiple lesions within the same patient for the late loss in minimum luminal diameter (rho = -0.12 [95% CI: -0.40, 0.12]), among lesions in the same vessel (rho = 0.14 [95% CI: -0.34, 0.62]), or among different vessels (rho = -0.18 [95% CI: -0.52, 0.16]), suggesting that the magnitude of late loss is independent among multiple lesions within the same patient. There was no difference (p = 0.96) between the observed incidence of zero-, one-, and two-vessel restenosis (> or = 50% diameter stenosis at follow-up) for patients with multiple-lesion treatment and that predicted assuming lesion-to-lesion independence. Similarly, there was no difference in late loss or in the overall binary restenosis rate when single-lesion procedures were compared with multilesion procedures. Multivariable analysis of the late loss in lumen diameter (which adjusted for the effects of the acute result and the device used) demonstrated no independent effect (p = 0.20) of single-lesion versus multilesion status. CONCLUSIONS: Luminal encroachment appears to occur at independent rates among multiple lesions treated in a single patient. The observed incidence of restenosis for patients with multiple treated lesions is accurately predicted assuming independent probabilities of restenosis. Lesion-based analysis, even when including multiple treated lesions within the same patient, is thus valid for evaluating conventional angioplasty, stenting, or directional atherectomy.

Angioplasty, Balloon, Coronary↗
PubMed1993

Excimer laser coronary angioplasty of aorto-ostial stenoses. Results of the excimer laser coronary angioplasty (ELCA) registry in the first 200 patients.

BACKGROUND: Percutaneous transluminal coronary angioplasty (PTCA) of aorto-ostial stenosis has been associated with a lower rate of acute success, a high risk of vessel closure, and late restenosis. The purpose of this report is to document a prospective multicenter trial of excimer laser coronary angioplasty (ELCA) of aorto-ostial stenosis involving the coronary arteries and saphenous vein grafts. METHODS AND RESULTS: Between December 1989 and May 1992, 206 aorto-ostial ELCA procedures were performed on 209 stenoses in 200 patients. Canadian Cardiovascular Society class III or IV angina was present in 76%. The distribution of stenosis locations was left main coronary (LM) in 26 (12%), right coronary (RCA) in 124 (59%), and vein grafts (VG) in 59 (28%). Adjunctive PTCA was performed in 72%. Procedure success defined as < or = 50% diameter stenosis without major complications was achieved in 90% (LM, 92%; RCA, 89%, VG, 90%). Quantitative angiographic analysis documented an improvement in stenosis diameter from 0.8 +/- 0.5 mm or 76 +/- 14% at baseline to 2.1 +/- 0.6 mm or 36 +/- 15% at completion (P < .01). The majority of the acute gain in diameter (1.0 +/- 0.6 mm) resulted from ELCA. A major complication during hospitalization occurred in 3.9% (death, 0%; Q-wave myocardial infarction, 0.5%; bypass surgery, 3.4%). The only logistic regression univariate and multivariate predictor of procedure failure was female gender. Six-month angiographic follow-up, available in 51% of eligible patients, documented an average lumen diameter of 1.7 +/- 1.0 mm and mean diameter stenosis of 46 +/- 26%. Restenosis (> 50% diameter stenosis) occurred in 39% (LM, 64%; RCA, 35%; VG, 35%). Restenosis was less likely when residual stenosis was < or = 35% (28% versus 53%, P < .05). Clinical events at follow-up were death, 2.7%; bypass surgery, 6.5%; myocardial infarction, 2.2%; and repeat angioplasty, 16.2%. Of the remainder, 78% were asymptomatic, class I or II for anginal symptoms. An adverse event during follow-up was more than twice as likely in the group with LM (50.0% versus 21.1%, P < .02). CONCLUSIONS: ELCA is acutely effective and safe therapy in patients with aorto-ostial stenosis. Six-month restenosis, adverse-event rates were higher and functional status was poorer in the group with LM stenosis. ELCA may be considered as an alternative to bypass surgery in carefully selected patients with isolated aorto-ostial stenosis of the RCA and saphenous vein grafts.

Adult↗
PubMed1993

[Clinical experience of Rotablator].

26 patients (27 lesions) who had severe calcified and diffuse lesions underwent Rotablator treatment, lesion characteristics were type B2, Type C of AHA/ACC classification. There were no patients who had type A1, type B1 lesions. Procedural success rate is 96%, coronary perforation occurred in one patient but not necessary for surgical treatment. Non Q myocardial infarction occurred only in one patient. Follow up Angioplasty were performed 1 and 3 months later after procedures. There were no restenosis after 1 month, but after 3 months, 56% of patients had restenosis.

Aged↗
PubMed1992

Reverse redistribution on Tl-201 SPECT images after reperfusion therapy for acute myocardial infarction: possible mechanism and prognostic implications.

So-called reverse redistribution on stress Tl-201 imaging has been reported previously, but its significance and clinical implications are not well understood. In patients who received reperfusion therapy for acute myocardial infarction, we frequently observed reverse redistribution on stress Tl-201 images. To investigate the significance of reverse redistribution, 61 patients who underwent reperfusion within 4 h of the onset of chest pain underwent submaximal exercise Tl-201 imaging 3 weeks later. We performed simultaneous coronary arteriography and left ventriculography. We divided these 61 patients into three groups based on the pattern of Tl-201 images. Reverse redistribution was found in 19 patients (Group A), 12 patients had redistribution (Group B), and 30 patients had nonreversible defects (Group C). All patients in Group A had less residual stenosis than those in the other groups, and showed significant improvement of left ventricular function. Furthermore, 12 patients (Group A) demonstrated reverse redistribution or a normal pattern in a follow-up study performed 12 months later. However, in the delayed images the defect was smaller than that shown in the previous study. None of the patients had any symptoms and all returned to their previous occupations. In conclusion, reverse redistribution was common in patients undergoing reperfusion therapy for acute myocardial infarction, especially those with little residual stenosis. Reverse redistribution appears to indicate improved regional wall function in such patients.

Aged↗
PubMed1992

Statistical analysis of clinical risk factors for coronary artery spasm: identification of the most important determinant.

Coronary artery spasm plays an important role in acute ischemic events, and it has a close relationship with coronary atherosclerosis. Thus we attempted to determine the most significant risk factor for coronary artery spasm. Among 3000 consecutive patients who underwent coronary cineangiography with ergonovine maleate testing, 330 with typical angina pectoris (group 1) and 294 with old myocardial infarction (group 2) were studied. We divided each group into three or four subgroups according to the presence of fixed organic stenosis (FOS+) or a positive reaction to ergonovine maleate (coronary artery spasm [CAS]+). We examined the relationship between coronary artery spasm and eight coronary risk factors: age, sex, hypertension, diabetes mellitus, smoking, and serum cholesterol, uric acid, and high-density lipoprotein cholesterol levels. The proportion of smokers in the subgroups with CAS(+) was significantly higher than in the subgroups with CAS(-)(p less than 0.01). There was no correlation between smoking and fixed organic stenosis. According to the results of multiple regression analysis, there was a positive correlation between smoking and CAS(+) and between serum high-density lipoprotein cholesterol levels and CAS(+)(p less than 0.01). Thus we concluded that smoking is the most significant risk factor in discriminating between patients with and without coronary artery spasm.

Cholesterol, HDL↗
PubMed1992

[Study on the therapy of multiple myelomas--initial induction therapy (MP, IFN alpha, steroid pulse) and maintenance therapy (VMP, MP continuous, VEP, MCNU)].

Untreated twenty patients of multiple myeloma were treated with the chemotherapy protocol as follows: Initial induction therapy;MP continuous or MP intermittent----IFN alpha----steroid pulse. Maintenance therapy;alkylating agents which have no cross resistance were used ((V) MP----(MP)----(V) EP----MCNU). Remission rate (CR+PR) after the initial MP therapy was 45%, and that after including IFN alpha and steroid pulse therapy was 50%, Fifty percent survival rate was almost as same as those reported previously (34M). Our protocol presented here was based on the idea that, initially, myeloma cells with proliferative activity could be affected by MP therapy, and subsequent IFN alpha therapy would have effect even on the residual myeloma cells. Serial checks of 3H-TdR uptake of myeloma cells during the therapy supported this idea. During the maintenance therapy, clinical responses to the initial induction therapy were not aggravated in the responded cases when evaluated by the variation of serum M-protein level. We propose that considering from a point of proliferative activity of myeloma cells is important for designing therapeutic protocols for multiple myeloma.

Adult↗