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Biomedical subjects

T Sumiyoshi

Publications and source records attributed to T Sumiyoshi.

At least 55 records · Page 3Linked to original sources
PubMed1996

[Detection of angina-related coronary artery in patients with unstable angina pectoris by using 123I-BMIPP myocardial scintigraphy].

To evaluate the diagnostic accuracy of detection of angina-related coronary arteries in patients with unstable angina pectoris. Twenty patients with unstable angina pectoris underwent 123I-BMIPP scintigraphy at rest. A mean duration from last anginal attack to 123I-BMIPP scintigraphy was 408 +/- 3.2 days. Seventeen of 20 angina-related coronary territories were detected by reduced 123I-BMIPP uptake. The sensitivity and specificity for detection of angina-related coronary arteries were 85% and 95%, respectively. The decrease in myocardial uptake of 123I-BMIPP agreed with the decrease in regional wall motion by using ultrasonic echocardiography. 123I-BMIPP scintigraphy may be useful for detection of angina-related coronary artery in a routine clinical examination in patients with unstable angina pectoris.

Aged↗
PubMed1995

Influence of plasma lipoprotein (a) levels on coronary vasomotor response to acetylcholine.

OBJECTIVES: This study was undertaken to examine the influence of plasma lipoprotein(a) [Lp(a)] levels on coronary endothelial vasomotor function. BACKGROUND: Epidemiologic studies have demonstrated a direct relation between elevated plasma levels of Lp(a) and increased risk of coronary artery disease. Well recognized coronary risk factors are known to affect endothelium-dependent vasomotion; however, the influence of Lp(a) on coronary vasomotor function has not been determined. METHODS: We used quantitative coronary angiography to measure left anterior descending coronary artery diameter changes produced by intracoronary acetylcholine and isosorbide dinitrate in 30 patients with angiographically normal coronary arteries. Plasma Lp(a) levels were determined with enzyme-linked immunosorbent assay. RESULTS: Vasomotor response to acetylcholine ranged from +13% to -47% in the proximal, from +23% to -53% in the middle and from +13% to -56% in the distal segment of the left anterior descending coronary artery. According to univariate linear regression analysis, Lp(a) had a significant inverse correlation with vasomotor response to acetylcholine: r = 0.47, p < 0.01 in the proximal; r = -0.61, p < 0.001 in the middle; and r = -0.52, p < 0.01 in the distal segment of the left anterior descending coronary artery. By multiple stepwise regression analysis, plasma Lp(a) was the significant predictor of vasomotion in response to acetylcholine in all tested segments (p < 0.01). CONCLUSIONS: Elevated Lp(a) levels were associated with impairment of endothelium-dependent vasodilation even when atherosclerotic lesions were not recognizable by angiography. This finding suggests that elevated plasma levels of Lp(a) cause endothelial dysfunction and may contribute in part to later development of atherosclerosis, as shown in epidemiologic studies.

Acetylcholine↗
PubMed1995

Dopamine D4 receptors and effects of guanine nucleotides on [3H]raclopride binding in postmortem caudate nucleus of subjects with schizophrenia or major depression.

The densities of dopamine-D4 receptors were determined in postmortem samples of caudate nucleus from patients with schizophrenia (n = 9) and age-matched controls (n = 10). D4 receptor binding was defined as the difference between binding sites labeled by [3H]YM-09151-2 (D2 + D3 + D4 receptors) and those by [3H]raclopride, in the presence of 5'-guanylylimidodiphosphate (Gpp(NH)p) (D2 + D3 receptors). D4 receptor binding was measurable in all the subjects with schizophrenia (mean = 3.8 pmol/g tissue) but only in 3/10 controls. To determine the specificity of these findings for schizophrenia, D4 receptor binding was also measured in the caudate nucleus of suicide victims with major depression (n = 6) and age-matched controls (n = 6). A small amount of D4 binding was noted in some of the controls + depressed subjects and there was no significant difference between controls and patients with major depression. The addition of 200 microM Gpp(NH)p to the assay significantly increased the amount of specific binding of [3H]raclopride in control tissues, but not in tissues from subjects with schizophrenia, suggesting an abnormality in the G-protein component coupled to the D2 receptor. [3H]Raclopride binding was also significantly increased by Gpp(NH)p in subjects with major depression. These results confirm a previous report of Seeman et al. (1993) and suggest that measurable D4 receptor binding in the caudate nucleus is more frequent in patients with schizophrenia as compared with normal controls and subjects with major depression and that guanine nucleotides do not enhance [3H]raclopride binding in schizophrenia.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Atypicality of several antipsychotics on the basis of in vivo dopamine-D2 and serotonin-5HT2 receptor occupancy.

An in vivo receptor binding technique was used to evaluate the binding profiles of typical and atypical antipsychotic drugs to striatal dopamine-D2 and frontal serotonin-5-HT2 receptors in a rat brain using more specific ligands than those previously employed. [3H]-YM-09151-2 or [3H]-ketanserin was injected into the tail vein 10 minutes after administration of test drugs. One hour after the ligand injection, radioactivities in the striatum, frontal cortex, and cerebellum were counted to obtain receptor occupancies by the test drugs. Higher ratios of potency in occupying 5-HT2 versus D2 receptors were found for clozapine, RMI-81512, and tiospirone compared to haloperiodol and pimozide. Zotepine, mosapramine, and clocapramine produced ratios that fall between these two groups. Chlorpromazine was exceptional as a typical antispychotic by these criteria. Relatively strong antagonism of 5-HT2 receptors by atypical antipsychotics was confirmed by this in vivo measure of receptor binding using more selective ligands than those used in previous studies.

Animals↗
PubMed1995

Comparison of the therapeutic efficacy of continuous and intermittent injection of isosorbide dinitrate: a randomized study on unstable angina.

Therapeutic efficacy of intermittent and continuous injection of isosorbide dinitrate (ISDN) was compared in 22 patients (mean age 64 +/- 10, 18 males and 4 females) with unstable angina at rest. They were randomized into 2 groups that received either continuous (10 mg/h, group A) or intermittent (10 mg/10 min every 2 hours, group B) injection of ISDN for 3 days (phase 1). Each injection protocol was switched (phase 2) and subsequently switched back to the initial protocol (phase 3) in a cross-over fashion. The serum concentrations of ISDN, 2-isosorbide mononitrate (2-ISMN) and 5-ISMN were measured serially during both intermittent and continuous injection protocols. In addition, the incidence and duration of angina and changes in systolic blood pressure were analyzed. There were 3 treatment-failure cases during the intermittent injection period and 1 during the continuous injection period. Three of these treatment-failure cases developed small acute myocardial infarcts despite emergent coronary arteriography followed by intra-coronary thrombolysis and percutaneous balloon angioplasty. There was no difference in therapeutic efficacy between continuous and intermittent ISDN in terms of the incidence, duration of angina attacks and the number of patients whose angina was suppressed. After bolus injection of ISDN (10 mg/10 min), the serum concentration of ISDN increased rapidly and returned to the control level at 60 minutes after the injection. The serum 5-ISMN and 2-ISMN concentrations also increased immediately after injection and then decreased gradually reaching statistically insignificant level to the control values at 60 minutes after injection. With continuous injection, ISDN and its metabolites increased gradually and reached similar but slightly lower serum concentrations to the peak levels during intermittent injection. We conclude that the therapeutic efficacy of intermittent and continuous injection of ISDN is similar in patients with unstable angina.

Adult↗
PubMed1995

[Clinical characteristics of pancreatitis after cardiovascular surgery].

Increases in pancreatic enzyme levels after cardiovascular surgery were studied, and their clinical characteristics evaluated. The subjects were 128 patients who had undergone cardiovascular surgery (65 patients after valve replacement, 32 after coronary bypass surgery and 31 after aortic artificial graft replacement). The pancreatic enzyme (serum amylase and lypase) levels were monitored serially before and after operation, and amylase fractions were measured at their peaks. The relationships of the peak lypase level with underlying cardiac diseases, background factors, factors related to surgery, factors related to the extracorporeal circulation, presence or absence of symptoms, and treatments were examined. The amylase level exhibited biphasic changes consisting of a peak in which salivary glands amylase (S type) was dominant and a peak in which pancreatic amylase (P type) was dominant. The second peak coincided with the peak lypase and occurred mostly 3 to 10 days after operation. The peak lypase level exceeded the normal range in 78% of all the patients. It exceeded 564 U/l, 4 times the normal value in 28% of the patients, many of whom were symptomatic. So, we recommended that these cases should be treated as "postoperative pancreatitis". A high peak lypase level showed a significant correlation with the history of gallbladder and pancreatic diseases and diabetes mellitus among the background factors and emergency operation and the use of IABP among the surgery-related factors.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

[Identification of viable myocardium using 99mTc-tetrofosmin scintigraphy--comparison with 201Tl redistribution-reinjection images].

The purpose of this study was to clarify the diagnostic value of identifying viable myocardium using 99mTc-Tetrofosmin scintigraphy. Twenty-one patients with chronic coronary artery disease were studied using 201Tl exercise myocardial scintigraphy with reinjection and 99mTc-Tetrofosmin exercise myocardial scintigraphy. All patients had a history of old myocardial infarction. For 99mTc-Tetrofosmin scintigraphy, 222 MBq of 99mTc-Tetrofosmin was injected during exercise, and exercise images were obtained 20 min thereafter. There hours later, 666 MBq of 99mTc-Tetrofosmin was injected at rest, and images were obtained 40 min and 220 min later. Myocardial viability in the 99mTc-Tetrofosmin scintigraphy was estimated as fill-in findings (FF) or over 50% of %RI uptake (%TF) in the rest image. Myocardial viability in the 201Tl scintigraphy was estimated as redistribution (RD), fill-in findings in the reinjection image (FR) or over 50% of %RI uptake in the reinjection image (% TL). Sixteen of the 21 patients (76%) who underwent 201Tl scintigraphy (RD 10, FR 3, %TL 3 cases) and 15 of the 21 patients (71%) who underwent 99mTc-Tetrofosmin scintigraphy (FF 11, %TF 4 cases) had viable myocardium in the infarcted area. A comparison between the 99mTc-Tetrofosmin rest images obtained 40 min after the injection and that of 220 min revealed no redistribution findings. The %RI uptake of the infarcted area in the resting 99mTc-Tetrofosmin image (47 +/- 16%) was slightly lower than that in the 201Tl reinjection image (52 +/- 16%). In conclusion, viable myocardium was as clearly identified by 99mTc-Tetrofosmin, as by 201Tl scintigraphy.

Aged↗
PubMed1995

[Simultaneous evaluation of myocardial perfusion and fatty acid metabolism using dynamic SPECT with single injection of 123I-15-(p-iodophenyl)-3-methyl pentadecanoic acid (BMIPP)].

The purpose of this study is to clarify whether dynamic SPECT (DECT) immediately after the injection of 123I-15-(p-iodophenyl)-3-methyl pentadecanoic acid (BMIPP) may represent myocardial perfusion imaging. Ten patients with unstable angina pectoris (UAP), 11 patients with acute myocardial infarction (AMI) and 6 patients with non-ischemic heart disease (NIHD) were studied using BMIPP myocardial scintigraphy with DECT. DECT acquisition was started 2 minutes after the injection of BMIPP, and DECT images were obtained every three minute for 15 minutes with 3-headed gamma camera SPECT system. Additionally, static SPECT images were acquired 30 minutes after the injection of BMIPP. These SPECT images of BMIPP were compared with thallium-201 myocardial perfusion images at rest. In UAP group, early DECT images showed almost the same findings as thallium-201 images in 8 of 10 patients, and SPECT images at 30 minutes after the injection showed reduced accumulation of BMIPP compared with thallium-201 images in all patients. In AMI group, early DECT images showed the same findings as thallium-201 perfusion images in 9 of 11 patients, and SPECT images at 30 minutes after the injection showed reduced accumulation of BMIPP compared with thallium-201 images in 5 of 11 patients. These results indicate that myocardial perfusion can be evaluated in the early image using DECT, in addition to myocardial fatty acid metabolism in the delayed image.

Adult↗
PubMed1994

In vivo dopamine-D2 and serotonin-5-HT2 receptor binding study of risperidone and haloperidol.

An in vivo receptor binding technique was applied to evaluate the affinities of risperidone and haloperidol for dopamine-D2 receptors (D2) and serotonin-5-HT2 receptors (5-HT2) in rat brain with [3H]YM-09151-2 and [3H]ketanserin as selective ligands. Radioactivities were obtained in the striatum frontal cortex, and cerebellum of the rats treated with the ligands. Time course study of receptor occupancy at 25 to 250 min after single doses of the drugs (1 mg/kg, IP) showed higher 5-HT2 occupancy in the frontal cortex and lower D2 occupancy in the striatum by risperidone than by haloperidol. Dose-response analysis of receptor occupancy revealed risperidone demonstrated higher binding affinity for 5-HT2 than for D2, while the reverse was observed with haloperidol. It appeared that risperidone (1 mg/kg, IP), but not haloperidol (1 mg/kg, IP), demonstrated regional selectivity in D2 occupancy favouring frontal cortex more than the striatum. That risperidone displayed a higher ratio of 5-HT2 to D2 in occupancy than haloperidol is in agreement with the previous findings obtained in vitro.

Animals↗
PubMed1994

Time course of dopamine1,2 and serotonin2 receptor binding of antipsychotics in vivo.

An in vivo receptor binding technique was applied to evaluate the affinities of clozapine (20 mg/kg), RMI-81582 (20 mg/kg), and haloperidol (1 mg/kg) for dopamine D1, D2 and serotonin 5-HT2 receptors in rat brain with [3H]-SCH23390, [3H]-YM-09151-2, and [3H]-ketanserin as selective ligands. The time course study of receptor occupancy at 25 to 250 min after intraperitoneal administration of the drugs showed higher 5-HT2 and lower D2 receptor occupancies of clozapine and RMI-81582 than those of haloperidol both in the striatum and frontal cortex. The 5-HT2/D2 ratios of receptor occupancy for clozapine and RMI-81582 were about 6 to 8 times higher than that for haloperidol. Stable occupancies of D1 receptors were observed only with RMI-81582 and clozapine, the former demonstrating the higher occupancy. These findings are in agreement with the previous findings obtained under in vitro conditions and may account for some part of the properties of atypical antipsychotic drugs.

Animals↗
PubMed1994

Intravenous diltiazem versus isosorbide dinitrate for unstable angina: comparison of coronary angiographic morphology in the unstable and stabilized states.

BACKGROUND: The efficacy of intravenous infusion of diltiazem was compared with that of isosorbide dinitrate (ISDN) for the early treatment of unstable angina. METHODS: Sixty-four patients with at least 70% organic stenosis of the culprit artery and prolonged rest angina were enrolled. Coronary angiography was performed on admission. Subsequently, patients were randomly assigned to receive either intravenous diltiazem or ISDN. Coronary angiography was repeated when the angina was under control, and the findings were compared with those on admission. RESULTS: Diltiazem was more effective than ISDN, and symptoms were resolved in 84% of the diltiazem group compared with 47% of the ISDN group (P = 0.0038). Repeat coronary angiography showed that the degree of stenosis remained unchanged in the majority of patients (n = 47, 75.8%). There was no difference between the two groups with regard to the coronary angiographic findings. CONCLUSIONS: Since diltiazem was more effective than ISDN even though the coronary angiographic findings of the two groups were similar, it is possible that some action other than vasodilatation (such as a direct protective effect on the myocardium) may be responsible for the remission of unstable angina.

Aged↗
PubMed1993

Time course of dopamine-D2 and serotonin-5-HT2 receptor occupancy rates by haloperidol and clozapine in vivo.

In vivo occupancy of dopamine-D1, D2 and serotonin-5-HT2 receptors by haloperidol 10 mg/kg and clozapine 20 mg/kg were studied. Rats were injected intravenously with [3H]-YM-09151-2, [3H]-SCH23390, or [3H]-ketanserin 10 min after the administration of the tested drugs. Fifteen to 240 min after the ligand injection, the receptor occupancy rates of the drugs in the striatum and frontal cortex were calculated. Clozapine demonstrated the higher 5-HT2 and lower D2 occupancies in the respective regions. A dose-response analysis of D2 and 5-HT2 receptor occupancy by the drugs consolidated the higher 5-HT2 binding affinity of clozapine in comparison with haloperidol. The present methodology may serve as an accurate tool to evaluate the peculiarity of various antipsychotics.

Animals↗
PubMed1993

[Significance of Tc-99m pyrophosphate accumulation in unstable angina: clinical characteristics and evidence for myocardial stunning].

Tc-99m pyrophosphate (PYP) and Tl-201 simultaneous dual energy single photon emission computed tomography (SPECT) were performed for 33 patients with clinically diagnosed unstable angina. Twenty-two patients (76%) showed PYP accumulation in the myocardium (PYP+group). Clinical features, types of unstable angina, electrocardiographic changes during and after the anginal attack, and serial creatine kinase (CK) sampling data were reviewed and compared in the 2 groups. Selective coronary angiography was performed in all patients, and contrast left ventriculography was carried out in 29 patients both in unstable and stable states. In the study of left ventriculograms, the ejection fraction (EF) was calculated by the area-length method and the wall motion abnormality index was calculated by the centerline method. The PYP(+)group differed significantly from the PYP(-)group in several features as follows: 1) the "new angina at rest" type of unstable angina was more frequent in the PYP(+)group than in the PYP(-)group. The ratios of new angina at rest/effort angina (including new angina of effort and angina of effort with changing pattern) were 16/6; 2/9 for the PYP(+) and (-)groups, respectively (p < 0.05). 2) ST elevation during the heart attack was seen more in the PYP(+)group. The ratios of ST elevation/ST depression were 13/22 (59%); 5/22 (23%) for the PYP(+)group, and 2/11 (18%); 7/11 (64%) for the PYP(-)group, respectively (p < 0.05). 3) EF was improved in the PYP(+) group to the normal range. EF in the PYP(+)group changed from 57 +/- 12 in the unstable state to 62 +/- 11% in the stable state (p < 0.02), while that of the PYP(-)group showed no significant difference between the unstable state (59 +/- 9%) and the stable state (59 +/- 11%). 4) Wall motion abnormality index (WMI) in the PYP(+)group was poorer than in the PYP(-)group, but it improved markedly in one month to the same level as that of the PYP(-)group. WMI in the PYP(+)group in the unstable state (21.7 +/- 26.2) was worse than that in the PYP(-)group in unstable state (5.7 +/- 8.2) (p < 0.001). WMI in the PYP(+)group in the unstable state markedly improved in the stable state (from 21.7 +/- 26.2 to 8.4 +/- 19.8) (p < 0.025); whereas, WMI of the PYP(-)group showed no significant improvement (from 5.7 +/- 8.2 to 15.5 +/- 19.6). These data suggest that the area showing PYP(+) may represent stunned myocardium.(ABSTRACT TRUNCATED AT 400 WORDS)

Angina, Unstable↗
PubMed1993

[Prolonged diastolic stunning after unstable anginal attacks].

To evaluate the changes in the left ventricular diastolic filling dynamics after severe myocardial ischemia, serial pulsed Doppler examinations of mitral flow were performed in 10 patients with unstable angina. Peak early and late filling velocities (E and A), the ratio (E/A), the area E (Ei) and A (Ai) and the ratio (Ei/Ai) were measured one, 3, and 7 days and one month after the last ischemic episode. Seven of 10 patients were treated with percutaneous transluminal coronary angioplasty (PTCA), and the same indexes were obtained one, 3, and 7 days and one month after PTCA. E/A and Ei/Ai increased significantly on the 3rd and 7th days, however, no further increase was observed one month after the last ischemic episode and after PTCA. Left ventricular diastolic dysfunction induced by severe myocardial ischemia persisted for several days after the stabilization of myocardial ischemia. After the ischemic episodes were stabilized by administering pharmacological therapy, left ventricular diastolic dynamics were unchanged before and after PTCA. These results indicate that there may be diastolic myocardial stunning in patients with unstable angina.

Angina, Unstable↗