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Biomedical subjects

Y Kusama

Publications and source records attributed to Y Kusama.

At least 37 records · Page 2Linked to original sources
PubMed1997

[Prediction of the myocardial contractility improvement on early stage after the revascularization using low-dose dobutamine stress 99mTc-MIBI gated SPECT].

For prediction of recovery of LV contractility, 99mTc-MIBI gated SPECT at rest and that with dobutamine (DOB) loading were performed in 15 patients with myocardial infarction (MI). Regional % uptake (regionalx100/maximal count), % wall thickening [%WT; (ES-ED)x100/ED maximal count], and delta %WT (%WT at DOB stress-%WT at rest) were calculated for each of 8 segments (seg.), including 34 MI out of total 120 seg., which derived from short axis LV count profile. These 34 seg. were divided into two groups, recontractile (18 seg.) and non-recontractile (16 seg.), whether improvement of the wall motion following the intervention (3-5 months) was observed by echocardiography. In the result, there were 7 recontractile seg. in 8 seg. with mildly reduced perfusion (> or = normal mean % uptake-2 S.D.), and there were 11 recontractile seg. in 26 seg. with severe reduced perfusion (< normal mean % uptake-2 S.D.). Moreover, in segments with severely reduced perfusion, there was no significant % uptake difference between recontractile and non-recontractile seg. However, delta %WT of recontractile group (11.1 +/- 4.8%) was significantly higher than that of non-recontractile group (5.7 +/- 2.9%) (p < 0.01). In conclusion, although the improvement of contractility on early stage after the revascularization was sometimes underestimated with only perfusion (% uptake), myocardial DOB response of %WT which were obtained by gated SPECT with MIBI would avoid the underestimation.

Angioplasty, Balloon, Coronary↗
PubMed1996

Eosinophilia, IL-5 level and recovery of larvae in IL-5 transgenic mice infected with Toxocara canis.

Eosinophil counts, interleukin 5 (IL-5) concentrations in peripheral blood and larval recovery after infection with Toxocara canis were compared between IL-5 transgenic (Tg) and nontransgenic counterparts, C3H/HeN mice. In Tg mice characterized by a constant high level of peripheral eosinophils, eosinophils in peripheral blood fell to the lowest level on day 4 of a T. canis infection and then returned to the preinfection level on day 14. Serum IL-5 level fell to the lowest level on day 4 of infection, then recovered rapidly and peaked on day 14 postinfection. In contrast, the eosinophil and IL-5 levels in the peripheral blood peaked on days 11 and 7 of infection, respectively in C3H/HeN mice. The degree of eosinophil infiltration into the lung 4 days after infection was far more pronounced in Tg than C3H/HeN mice. The highest number of larvae recovered from the lungs of infected Tg and C3H/HeN mice occurred on day 4 postinfection. Strains of Tg and C3H/ HeN mice vaccinated with excretory and secretory (ES) antigens of T. canis larvae were infected with T. canis and the recovery of larvae on day 21 analysed. There were no significant differences in the mean number of larvae recovered from nonvaccinated Tg and C3H/HeN mice or vaccinated Tg and C3H/HeN mice. However, significant differences were demonstrated in the mean total number of larvae recovered from vaccinated and nonvaccinated Tg or C3H/HeN mice. These results suggest that immunocompetent cells other than eosinophils may play a significant role in the expulsion and killing of T. canis larvae in infected mice.

Animals↗
PubMed1996

Adenosine mediates the antiarrhythmic effect of ischemic preconditioning in isolated rat hearts.

Adenosine appears to mediate the preconditioning-induced reduction in infarct size in rabbits and dogs, but little is known about the role of adenosine in preconditioning-induced protection against ischemia-induced arrhythmias. We compared the effects of preconditioning induced by 2 cycles of 5 min of global ischemia and 2 cycles of 5 min of perfusion with either adenosine (100 mumol/L) or the adenosine A1-selective agonist 2-chloro-N6-cyclopentyladenosine (CCPA, 100 nmol/L) in protecting against ischemia-induced arrhythmias in Langendorff-perfused rat hearts. Preconditioning reduced the incidence of ventricular tachycardia (VT) from 100 to 58% and the incidence of sustained VT or ventricular fibrillation (VF) from 92 to 33%. Perfusion with adenosine reduced the incidence of VT from 100 to 55%, the incidence of VF from 67 to 9% and the incidence of sustained VT or VF from 92 to 9%. CCPA reduced the incidence of sustained VT or VF from 92 to 25%. These interventions provided a true reduction in the severity of arrhythmias, rather than merely a delay in the onset. Our results suggest that the stimulation of A1 receptor by adenosine is involved in triggering ischemic preconditioning-induced protection against ischemia-induced arrhythmias in rats.

Adenosine↗
PubMed1996

Significant characteristics of variant angina patients with associated syncope.

To determine whether syncope predisposes to sudden cardiac death, variant angina patients with syncope during cardiac attacks were compared with those without syncope. There were 240 consecutive patients (193 males and 47 females) diagnosed with variant angina pectoris. Thirty patients had a history of syncope during cardiac attacks while the remaining 210 had none. The incidence of cardiac events in the former group was 10.0% (3 of 30) and 10.5% in the latter. There were 3 cases of sudden cardiac death, all in the latter group. Significant clinical variables in the syncope patients included inferior ST-segment elevation and serious arrhythmias. We conclude that there is no relationship between syncope during variant angina and sudden cardiac death.

Adult↗
PubMed1996

Prognostic indicators of major cardiac events in patients with asymptomatic coronary artery disease.

We investigated the role of myocardial ischemia in acute myocardial infarction and cardiac death in 253 patients with asymptomatic coronary disease (206 men, 47 women, mean age: 55 +/- 8 years). Patients were divided into two groups: those with angina pectoris with no history of myocardial infarction (AP group, 93 patients) and those with a history of myocardial infarction (MI group, 160 patients). We also examined the usefulness of exercise electrocardiographic and Holter electrocardiographic findings as prognostic indicators of cardiac events. After 24-hour Holter electrocardiograms were obtained in both groups, patients were assigned to subgroups with or without silent myocardial ischemia (SMI) based on the presence or absence of transient ST-segment depression. Prognostic indicators were evaluated by multiple regression analysis. Cardiac events occurred in 26 (10.3%) of 253 patients; in 6 patients these events were fatal. The incidence of cardiac events was significantly higher in the SMI group than in the non-SMI group (16.4% versus 5.6%, p < 0.05). SMI was identified as a significant prognostic indicator in the overall population (p = 0.0088), as were the number of diseased coronary arteries in the AP group (p = 0.0152), and SMI (p = 0.0022) in the MI group. There were 3 deaths related to cardiac events in each group. The mean time from onset of angina pectoris to death was 73 +/- 41 months compared with 33 +/- 43 months in the MI group. Our findings suggest that the severity of the coronary lesion and SMI were important predictors of major cardiac events, and that the mechanism of the onset of cardiac events was different in the AP and MI groups.

Adult↗
PubMed1996

[ECG-gated myocardial SPECT with 99mTc-MIBI in patients with right ventricular infarction].

Although 99mTc-pyrophosphate (PYP) myocardial scintigraphy has so far been widely used for the diagnosis of right ventricular infarction, PYP accumulation disappears within one week or so. To evaluate the myocardial condition of the right ventricle alternatively, myocardial SPECT with 99mTc-MIBI was performed in 16 patients with acute inferior left ventricular infarction, and ECG-gated myocardial SPECT data acquisition was accompanied in 14 of 16 patients. Right ventricular perfusion defect was observed in 4 of 16 patients (RVI (+) group), and the remains were negative (RVI (-) group). Then, right ventricular count increase rate (RV %WT) of MIBI from end-diastole to end-systole was calculated using an automated method which was developed for quantification of wall thickening in our laboratory. The RV %WT was conceived to be an objective index representing right ventricular contractility. RVI (+) group (n = 3) as compared with RVI (-) group (n = 11) had significant lower RV %WT (26.7 +/- 3.2 vs. 49.6 +/- 14.2; p < 0.01). In conclusion, ECG-gated myocardial SPECT with MIBI was considered to be useful for assessment of myocardial perfusion and contractility of right ventricle.

Aged↗
PubMed1996

[ECG-gated dual-isotope myocardial SPECT with 201Tl and 99mTc-tetrofosmin: simultaneous assessment of stress/rest myocardial perfusion and left ventricular function].

ECG-gated dual-isotope acquisition protocol involving rest imaging with 201Tl and stress 99mTc-tetrofosmin (TF) SPECT was designed for the simultaneous assessment of rest/stress myocardial perfusion and rest ventricular systolic function. This study assessed the feasibility and diagnostic accuracy of this protocol. Forty-five patients underwent the dual-isotope SPECT protocol. Twenty minutes after resting injection of 111 MBq of 201Tl, 370 MBq of 99mTc-TF was administered at a peak exercise. The dual-isotope gated SPECT acquisition was performed 1 hour later. Then, the regional count increase rate (%WT) of 99mTc-TF from end-diastole end-systole was calculated using an automated method which was developed for quantification of regional wall thickening based on circumferential profile analysis in our laboratory. Myocardial perfusion and contractility analysis was carried out using 8 segments of left ventricle with comparison of coronary angiographical findings. The sensitivity and specificity for the detection of diseased coronary vessels (> = or 75% stenosis) were 76% and 94%, respectively. Infarcted regions showing reversible defect had significantly greater %WT as compared with those with fixed defects (63 seg; 12.7 +/- 6.1% vs. 36 seg; 8.9 +/- 7.2%, p < 0.01). In conclusion, this dual-isotope protocol has some advantages; i.e., shortening an examination time, having the exact registration of stress/rest perfusion, and simultaneous evaluation of resting regional wall thickening.

Coronary Angiography↗
PubMed1995

Occurrence of interleukin-5 production by CD4- CD8- (double-negative) T cells in lungs of both normal and congenitally athymic nude mice infected with Toxocara canis.

We studied cells in the lungs of BALB/c and BALB/c-nu/nu (nude) mice infected with Toxocara canis, which produced interleukin-5 (IL-5) in in vitro culture with larval excretory-secretory antigen (ESAg). The proportion of CD4+/CD8+/CD4- CD8- cells in lungs of both BALB/c and nude mice was unchanged before and after infection with T. canis. Panning and complement-mediated lysis using monoclonal antibody (mAb) to CD4 showed that CD4+ cells in the lung from both mice produced IL-5. Anti-CD4 mAb suppressed ESAg-stimulated IL-5 production in vitro. In vitro depletion or inhibition of CD8+ cells reduced IL-5 production significantly in some cases, suggesting involvement with IL-5 production. Anti-CD3 mAb enhanced IL-5 production when incubated with or without ESAg. Production of IL-5 was reduced by in vivo depletion of CD4+ cells only and both CD4+ and CD8+ T cells, by intraperitoneal injection with appropriate mAb; IL-5 production was stimulated by anti-CD3 mAb. In contrast, IL-5 production by lung cells of BALB/c mice decreased by more than 90% after simultaneous injection with anti-CD4, anti-CD8 and anti-CD3 mAb, and was not enhanced by anti-CD3 mAb. Similar results were obtained in nude mice. These results suggest that CD4- CD8- T cells, as well as CD4+ T cells, produce IL-5.

Animals↗
PubMed1995

[ECG-gated dual isotope myocardial SPECT with 99mTc-MIBI and 123I-BMIPP in patients with ischemic heart disease].

Simultaneous dual-isotope SPECT with 99mTc-methoxy isobutyl isonitrile (MIBI) and 123I-beta-methyl iodophenyl-pentadecanoic acid (BMIPP) was performed in 25 patients with ischemic heart disease. ECG-gated myocardial SPECT was acquired following the injection of MIBI (555 MBq) and BMIPP (148 MBq). Both MIBI and BMIPP scans provided high-quality myocardial images. Then, myocardial count increase rate (%WT = ES-ED/ED x 100) was calculated as an index of left ventricular contraction using MIBI gated SPECT data. The %WT was well correlated with severity scores of both MIBI image (r = -0.70) and BMIPP image (r = -0.72). Thus, ECG-gated dual-isotope SPECT with MIBI and BMIPP was considered to be useful method for assessment of left ventricular contraction as well as myocardial perfusion and fatty acid metabolism.

Aged↗
PubMed1995

Mechanisms of eosinophilia in BALB/c-nu/+ and congenitally athymic BALB/c-nu/nu mice infected with Toxocara canis.

We studied the mechanism of eosinophilia in BALB/c-nu/+ (nu/+) and BALB/c-nu/nu (nu/nu) mice infected with Toxocara canis. Eosinophilia with two peaks on days 11 and 21 of infection was observed in infected nu/+ mice, and with a peak on day 11 in nu/nu mice. Interleukin-5 (IL-5) mRNA was expressed on day 5 of infection in the lung and spleen of nu/+ mice and in the lung of nu/nu mice, but not in the spleen of nu/nu mice. Large numbers of eosinophils and lymphocytes infiltrated the lung of both mice 1 week after infection. The number of larvae in the lung was the largest on day 5. Anti-IL-5 monoclonal antibody (mAb) treatment completely inhibited eosinophilia of both mice, with no change of larval distribution. Administration of anti-CD4 or anti-CD3 mAb markedly reduced the second peak of eosinophilia on day 21 of infection in nu/+ mice, and slightly reduced the first peak of eosinophilia on day 11 in both mice. Anti-CD8 mAb had no effect on the eosinophilia. These results suggest that eosinophilia in both mice is caused by IL-5, and that IL-5 is produced by cells other than CD4+ T cells, in addition to CD4+ T cells.

Animals↗
PubMed1995

[Low-dose dobutamine stress test for the evaluation of cardiac function using ECG-gated SPECT scintigraphy with 99mTc-MIBI].

Although 201TlCl myocardial scintigraphy has so far been widely used for the evaluation of the viability of the myocardial infarcted area, functional evaluation using low dose dobutamine (DOB) loaded echography also became recently available. We performed 99mTc-mIBI gated SPECT on eight cases of myocardial infarction at rest and low dose (4-6 micrograms/kg/min) DOB-loading and related data were collected. Next, we calculated myocardial count increase rate (% WT = ES-ED/ED x 100) with left ventricular contraction from end-diastolic (ED) and end-systolic (ES) pictures in short-axial image, and made a comparative examination of regional contractilities at rest and DOB-loading. DOB-loaded echography performed on the same cases at the same dose revealed 15 segments as infarcted area (WM (+)) presenting improvement in wall movement at loading and 5 segments as infarcted area (WM (-)) presenting no such improvement, and %WT at rest and loading were 29.1 +/- 6.2 and 33.2 +/- 2.4 for (WM (-)) and 26.8 +/- 9.8 and 40.0 +/- 12.3 for (WM (+)), indicating a significant increase (p < 0.05) at loading. Contractility analysis using MIBI gated SPECT in combined use of DOB-loading was considered as a useful method of examination in view of its reflectability in the evaluation of the wall movement in DOB-loaded echography and of its high quantitativity.

Aged↗
PubMed1994

Biocompatibility of heparin-coated membrane oxygenator during cardiopulmonary bypass.

The biocompatibility of the cardiopulmonary bypass (CPB) circuit, in which an oxygenator is solely heparinized, was assessed by systemic inflammatory reactions as an indicator during CPB. Fourteen patients, 11 males and 3 females, underwent coronary artery bypass surgery and were randomly divided into 2 groups of 7 patients each. For the heparin-coated oxygenator group (Group H), a heparin-coated membrane oxygenator was used in the CPB circuit, and in the control (Group C) an uncoated membrane oxygenator was employed. Systemic inflammatory reactions, such as platelet activation, prostaglandin production, complement activation, and activated granulocyte released substance, were measured prior to, during, and 6 h after CPB. The number of platelets decreased after protamine administration in both groups (14.5 +/- 4.7 x 10(4)/microliters in Group H and 13.8 +/- 8.7 x 10(4)/microliters in Group C) and returned to baseline levels in Group H while it remained decreased in Group C at 6 h after CPB. The platelet factor 4 level was significantly lower in Group H (181 +/- 40 ng/ml) than in Group C (297 +/- 131 ng/ml) after protamine administration. Thromboxane-B2 (TXB2) rose during CPB in both groups; however, there were significantly different levels of TXB2 between the 2 groups at 60 min after CPB (293 +/- 258 pg/ml in Group H versus 408 +/- 120 pg/ml in Group C) and after protamine administration (259 +/- 122 pg/ml in Group H versus 709 +/- 418 pg/ml in Group C). Plasma concentrations of granulocyte elastase were significantly lower in Group H at 30, 60 and 90 min, immediately after, and post-CPB than those of Group C.(ABSTRACT TRUNCATED AT 250 WORDS)

6-Ketoprostaglandin F1 alpha↗
PubMed1993

[A case of rheumatoid arthritis with obstructive bronchiolitis appearing after D-penicillamine therapy].

A 56-year-old woman was diagnosed as having rheumatoid arthritis in 1983. She was treated with D-penicillamine in addition to non-steroid anti-inflammatory drugs from April 1990. In August she noticed shortness of breath on exertion. Chest X-ray films showed bilateral interstitial shadows, and chest CT revealed bilateral multiple wedge-shaped shadows extending distally. Blood gas analysis showed severe hypoxemia and pulmonary function tests demonstrated decreased %VC, FEV1.0% and diffusion capacity. Open lung biopsy specimens revealed infiltration of inflammatory cells and fibrotic change in the walls of bronchioles. She was diagnosed as having obstructive bronchiolitis. Corticosteroid therapy and discontinuation of D-penicillamine therapy stopped the progression of her symptoms, and she was discharged on corticosteroid maintenance treatment and home oxygen therapy.

Arthritis, Rheumatoid↗