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Biomedical subjects

A Ohno

Publications and source records attributed to A Ohno.

At least 145 records · Page 8Linked to original sources
PubMed1991

Importance of coronary collateral circulation for increased treadmill exercise capacity by nitrates in patients with stable effort angina pectoris.

The purpose of this study was to elucidate the mechanism that induces an improvement in exercise capacity by nitrates in patients with stable effort angina pectoris. The study population was composed of 19 patients: group A, 10 patients with chronic stable effort angina who had a well-developed coronary collateral circulation to the potentially ischemic region; group B, 9 patients with chronic stable effort angina who had no collateral circulation to the jeopardized myocardium. Treadmill exercise was performed according to the standard Bruce protocol with and without pretreatment with orally administered 10 mg isosorbide dinitrate. Percent increases (mean +/- SE) in exercise duration were not significantly different between groups A and B (25 +/- 6 vs. 14 +/- 6%). Percent increases in the maximal rate-pressure product tended to be greater in group A than in group B (27 +/- 6 vs. 10 +/- 6%). Percent increases in the rate-pressure product at the onset of angina pectoris were significantly greater in group A than in group B (37 +/- 7 vs. 7 +/- 6%; p less than 0.01). Percent increases in the rate-pressure product at 0.1 mV S-T segment depression were also significantly greater in group A than in group B (26 +/- 6 vs. 1 +/- 5%; p less than 0.01). These results suggest that isosorbide dinitrate dilates epicardial collateral vessels with smooth muscle layers, but fails to dilate the coronary arteries with significant organic stenoses.

Angina Pectoris↗
PubMed1991

[Prognostic significance of radionuclide-assessed right ventricular function in dilated cardiomyopathy].

To assess the prognostic significance of right ventricular function in dilated cardiomyopathy (DCM), we studied consecutive 57 DCM patients. There were 41 men and 16 women, whose mean age was 48 ys. (range 3-68 ys.). The mean LVEF in all patients was 29 +/- 11%, and the mean interval from the onset of symptom of cardiac failure (CHF history) was 4 ys. (range 0-33 ys.). With follow-up of 3.8 ys., five patients had died until the first year, and 14 had died until the third year. By using multivariate regression analysis, there were no prognostic significance in clinical parameters such as age, CHF history, sex, atrial fibrillation, except for NYHA class, and medication at the third year. In survival curves according to Kaplan-Meier method, RVEF and mean PA had predictive value (p less than 0.05), while LVEF did not. The patients with RVEF less than 45% had poor survival rate compared to those with RVEF greater than or equal to 45%. The patients with RVEF less than 45% showed lower LVEF and LVESVI. RVEF may offer prognostic predictive value through the effect of not only mean PA but also left ventricular parameter. In conclusion, radionuclide assessment of right ventricular function should be valuable for the prognostic evaluation of DCM patients.

Adolescent↗
PubMed1991

Usefulness of pulsed Doppler ultrasound in detection of angiographically evident recurrence of hepatocellular carcinoma after arterial embolization treatment.

Because hepatocellular carcinoma treated by transcatheter arterial embolization often regains its size, routine follow-up is necessary. The usefulness of pulsed Doppler ultrasound for detection of this type of recurrence was compared with ultrasonography and computed tomography in 21 such hepatocellular carcinomas. Of 15 hepatocellular carcinomas diagnosed by angiography as showing recurrence, four were detected with ultrasonography and five were detected with computed tomography. Doppler signals were obtained in the peripheral portions corresponding to tumor vessels or stains on angiograms in 14 of these 15 hepatocellular carcinomas, but they were undetectable in six hepatocellular carcinomas with no recurrence. All signals disappeared after transcatheter arterial embolization. One false-negative hepatocellular carcinoma with pulsed Doppler ultrasound showed faint tumor stains on angiograms; these were also negative on ultrasonography and computed tomography. Pulsed Doppler ultrasound may be superior to ultrasonography and computed tomography as a routine procedure to detect the recurrence of hepatocellular carcinoma treated by transcatheter arterial embolization.

Aged↗
PubMed1991

[A case of iron and aluminum related osteomalacia in a long-term hemodialysis patient].

A 32-year-old woman undergoing hemodialysis for 12 years was referred because of systemic bone pain and pathological fracture of ribs and right tibia. Her serum ferritin was 4800 ng/ml, liver CT level was extremely high and skeletal scintigram by 99 m-Tc-MDP revealed high activity of soft tissue. Her serum aluminum was elevated more than 20 micrograms/dl by deferoxamine infusion test. Osteomalacia and positive staining of both aluminum and iron was observed by bone biopsy examination. After treatment with deferoxamine as a chelating agent of iron and aluminum, bone pain was relieved and second bone biopsy specimen revealed improvement of osteomalacia. But serum aluminum was slightly reduced and serum ferritin level and liver CT level were unchanged.

Adult↗
PubMed1991

[Prognostic significance of scintigraphic silent myocardial ischemia detected by stress thallium scan in patients with recent myocardial infarction].

To evaluate the prognostic significance of scintigraphic silent myocardial ischemia (SMI) detected by stress thallium scan in patients with myocardial infarction (MI), we performed a retrospective investigation on cardiac events (CE) during a two-year follow-up period in 149 patients with MI within three months of onset (34 +/- 19 days). SMI was defined as asymptomatic redistribution (RD) in the infarcted area. The patients were divided into three groups based on results of stress thallium scan as follows: 50 patients with neither chest pain nor RD (Group A), 46 patients with SMI (Group B) and 53 symptomatic patients (Group C). In comparison of the incidence of CE, which included cardiac death, recurrent MI, chronic heart failure, angina pectoris, PTCA, CABG and severe ventricular arrhythmia (lown grade greater than or equal to 3) during two-year follow-up, Group C had significantly higher incidence of PTCA and CABG than Group B (p less than 0.01), but there was no significant difference of other CE between groups B and C except PTCA and CABG. In addition, Groups B and C had a significantly higher incidence of CE than Group A in cardiac event-free curves, but there was no significant difference for Groups B and C. We conclude that patients with SMI are associated with unfavorable prognosis as symptomatic patients and that these patients should undergo careful follow-up.

Aged↗
PubMed1991

[Perfusion lung scintigraphy in primary pulmonary hypertension].

Fifteen cases with primary pulmonary hypertension (PPH) were classified into two groups by using the perfusion lung scan pattern. Eight cases had multiple, small, ill-defined defects (mottled pattern), and remaining seven cases had no mottled pattern. These two groups were compared with mean pulmonary arterial pressure (mean PAP), right ventricular ejection fraction (RVEF), blood gas at room air (PaO2), and alveolar-arterial O2 difference (A-aDo2). The cases with mottled pattern showed a significant increase in mean PAP. There were no significant differences in RVEF, PaO2, and A-aDo2, between the groups. The survival rate of the patients with mottled pattern was significantly lower than that without mottled pattern (p less than 0.05). We concluded that perfusion lung scan is very useful for evaluation of the prognosis in primary pulmonary hypertension.

Adolescent↗
PubMed1990

Mucinous adenocarcinoma of the submandibular gland.

A rare tumor not easily classifiable among published histologic categories for salivary gland tumors is reported. The neoplasm developed within the submandibular gland of a 78-year-old woman with invasion of the mandible and metastasis to regional lymph nodes. Histopathologically, cuboidal cells possessing clear cytoplasm and displaced round nuclei proliferated and exhibited an adenomatous pattern. Many cystic spaces surrounded by tumor cell strands were seen, mucus substance filled in the cystic spaces, and the tumor cells seemed mucus-secreting, but neither epidermoid cells nor papillary appearance could be observed. Electromicroscopically, numerous mucous droplets of low electron density were prominent in the cytoplasm, and the tumor cells had sparse irregular microvilli on the luminal surface. Mucin histochemistry, including paradoxical concanavalin A staining, revealed that the tumor cells contained neutral and acid mucins, and these were identified as class II and III mucosubstances. No other neoplastic lesion, except recurrent metastatic neck nodes, has been detected 6 years after the first examination, and it seems that the tumor is a rare primary mucinous adenocarcinoma of the submandibular gland.

Adenocarcinoma, Mucinous↗
PubMed1990

Importance of myocardial ischemia for coronary collateral development in conscious dogs.

The purpose of this study was to evaluate the effects of myocardial ischemia on the development of collateral circulation. Thirteen conscious dogs were instrumented for serial measurements of subendocardial segment length in the area perfused by the left circumflex coronary artery, left circumflex coronary artery flow and left ventricular pressure. In 6 dogs (group A), 1 min left circumflex coronary artery occlusions were carried out at 30 min intervals. When the 442nd 1 min left circumflex coronary artery occlusion produced a reduction in segment shortening and a significant reactive hyperemia, the occlusion time was increased to 2 min. In the remaining 7 dogs (group B), 2 min left circumflex coronary artery occlusions were conducted hourly. In group A, following 451 +/- 201 (SD) min of total occlusion time with the mixture of 1 and 2 min left circumflex coronary artery occlusions (43 +/- 18 days) a left circumflex coronary artery occlusion produced no reduction in segment shortening and negligible reactive hyperemia. By contrast, in group B, 218 +/- 99 min of total occlusion time (18 +/- 8 days) was required to develop adequate collateral circulation. The relative contribution of the first and second 1 min of left circumflex coronary artery occlusion to the collateral development was mathematically evaluated. This analysis indicated that the second 1 min of left circumflex coronary artery occlusion is 4.43-fold more effective than the first 1 min of occlusion in terms of the collateral induction. We concluded that severe myocardial ischemia plays an important role in the development of collateral circulation.

Animals↗
PubMed1990

Importance of myocardial ischaemia for recruitment of coronary collateral circulation in dogs.

STUDY OBJECTIVE: The aim of the study was to investigate collateral coronary flow and regional myocardial function following different coronary occlusion protocols. DESIGN: Effects of brief left anterior descending artery (LAD) occlusions in dogs (using a pneumatic occluder around the proximal artery) on collateral circulation were evaluated using three different protocols, each producing the same period of pressure gradient across the collateral network: (1) 10 s occlusion X 30 at 1 min intervals; (2) 1 min occlusion X 5 at 1 min intervals; (3) 5 min occlusion X 1. Each protocol was followed by a 10 s occlusion after a further 1 min period. SUBJECTS: 14 mongrel dogs of either sex were used, weight 10-21 kg. MEASUREMENTS AND MAIN RESULTS: Left ventricular pressure, left circumflex coronary artery (LCCA) flow, and subendocardial segment shortening (% delta L) in the area perfused by the LAD were monitored. Collateral blood flow from LCCA to LAD territory was measured as a stepwise decrease in LCCA flow on release of LAD occlusion. During the first 10 s of occlusion, % delta L decreased from 23.6(SEM 2.2)% to 14.2(2.9)%. After protocol (1), % delta L decreased from 23.1(2.2)% to 14.8(3.0)%. By contrast, after protocol (2) and (3) % delta L decreased only slightly, from 22.7(2.6)% to 20.5(2.8)%, and from 22.4(2.4)% to 19.8(2.4)%, respectively. Although collateral blood flow remained unchanged after protocol (1), it increased from 1.6(0.4) ml.min-1 during the first LAD occlusion to 3.0(0.7) ml.min-1 (p less than 0.05) after protocol (2), and to 3.5(0.6) ml.min-1 (p less than 0.05) after protocol 3. Haemodynamic measurements prior to each 10 s LAD test occlusion remained unchanged throughout the experiment. CONCLUSIONS: The pressure gradient across the collateral network cannot dilate pre-existing collateral vessels by itself, but ischaemia related metabolites may play an important role in the recruitment of collateral circulation.

Animals↗
PubMed1990

Combined tensor fasciae latae musculocutaneous flap and sartorius musculocutaneous flap for the repair of wide defects of the lower leg.

The tensor fasciae latae musculocutaneous flap has great advantages for reconstruction of the abdominal wall, but the medial border of its territory is limited to the thigh. In order to expand the territory, a combined tensor fasciae latae musculocutaneous flap and sartorius musculocutaneous flap was devised. This flap was successfully used to resurface a large defect in the lower leg as a distally based musculocutaneous flap. The advantages of this flap are its extremely large territory, the fact that total necrosis of the flap cannot occur, and that as a proximally or distally pedicled flap it is suitable for large defects in the abdominal wall, lower leg, and gluteal region.

Adult↗
PubMed1990

[The conjugative transfer of beta-hemolysin plasmid in Enterococcus faecalis to Enterococcus faecium].

The conjugative transfer by using a filter mating method in 109 cases of combinations between 20 strains of beta-hemolytic Enterococcus faecalis and 28 strains of alpha-hemolytic Enterococcus faecium was tried. A stable transconjugation was observed in two cases: from E. faecalis No. 170 to E. faecium No. 49 and from E. faecalis No. 500 to E. faecium No. 48. From the results, it was proved that the beta-hemolysin plasmid of E. faecalis is transferred by conjugation to E. faecium. The virulence (LD50) of E. faecium No. 17049, No. 50048 (heterogeneous transconjugant) and E. faecalis No. 17067, No. 50067 (homologous transconjugant) in mice was compared with their parent strains. The virulence of E. faecalis transconjugants was more marked than that of the recipients. However, the virulence of E. faecium transconjugants was not enhanced. This fact suggests that, only in E. faecalis, does beta-hemolysin play a role in its pathogenicity in mice. beta-Hemolysin in E. faecium transconjugants does not participate in pathogenicity in mice. It may be due to the fact that it takes more time to cause beta-hemolysis on blood agar plate or beta-hemolysin production in B-YEG broth by E. faecium transconjugants than by E. faecalis transconjugants.

Animals↗
PubMed1990

Improvement of ST segment depression by gradual recruitment of collateral circulation.

The purpose of the present study was to document that the coronary collateral vessels do not open immediately upon the occurrence of myocardial ischemia. A multistage bicycle exercise was performed to determine a maximal tolerable work load until the onset of angina and significant ST segment depression in 10 patients with well-developed collateral circulation. On a different day, exercise with the maximal tolerable work load was repeated for a comparable exercise duration. In 2 of the 10 patients, anginal pain was gradually alleviated despite the continuation of exercise with fixed work load. The extent of ST segment depression at 3 min of exercise with fixed work load was 0.20 +/- 0.10 (SD) mV, significantly (p less than 0.05) greater than 0.16 +/- 0.08 mV at the end of exercise with fixed work load. In contrast, the rate-pressure product was smaller at 3 min than at the end of exercise with fixed work load (20,900 +/- 5,500 vs. 22,700 +/- 5,700 mm Hg.beats/min; p less than 0.05). In 5 patients without well-developed collateral circulation, the extent of ST depression changed in parallel with changes in rate-pressure product during exercise with fixed work load. Thus, it is concluded that the delayed collateral opening plays a critical role in the pathogenesis of myocardial ischemia in patients with a totally occluded coronary artery.

Adult↗
PubMed1990

[Walk-through phenomenon by gradual recruitment of collateral circulation].

The present study was performed to investigate whether coronary collateral vessels open immediately after occurrence of myocardial ischemia. Multistage bicycle exercise was performed to determine the maximum tolerable workload until the onset of angina and significant ST segment depression in 10 patients with well-developed collateral circulation. On a different day, exercise using the maximum tolerable workload was repeated for comparable exercise durations. In two of the 10 patients, anginal pain was gradually alleviated despite the continuation of exercise using the fixed workloads. The extent of ST segment depression during three min exercise with the fixed workload was 0.20 +/- 0.10 (SD) mV, which was significantly (p less than 0.05) greater than 0.16 +/- 0.08 mV at the end of exercise with fixed workload. By contrast, the pressure-rate product was smaller at three min than at the end of exercise using the fixed workload (20,900 +/- 5,500 vs 22,700 +/- 5,700 mmHg-beats/min; p less than 0.05). It was concluded that delayed collateral openings play a critical role in the pathogenesis of the walk-through phenomenon.

Adult↗
PubMed1990

[Significance of collateral circulation in reversible asynergy].

The functional role of collateral circulation in reversible asynergy of the left ventricle was evaluated. Cineventriculograms were obtained before and after the administration of sublingual nitroglycerin (0.3 mg) in 19 patients with complete occlusion of the proximal portion of the left anterior descending coronary artery. In nine patients with well-developed collateral circulation, both left ventricular ejection fraction and regional wall motion were significantly improved by nitroglycerin. By contrast, in 10 patients without significant collateral circulation, there were no detectable changes in both global and regional wall motions before and after nitroglycerin. The left ventricular hemodynamic changes caused by nitroglycerin were comparable in both groups. These findings support the view that the improvement in asynergy caused by nitroglycerin appears to depend mainly on the extent of collateral circulation, rather than on decreases in both preload and afterload.

Aged↗
PubMed1990

Regional myocardial hypertrophy induced by repeated brief coronary occlusion in conscious dogs.

The purpose of the present study was to evaluate whether repeated brief coronary occlusion induces myocardial hypertrophy in the region subjected to reversible ischemic insult. In five conscious dogs, a subendocardial segment length in the area perfused by the left circumflex coronary artery (LCCA) was measured along with left ventricular pressure. After complete recovery from surgery, 167 (mean) 2-minute LCCA occlusions were repeated for 22 days. Before and after repeated coronary occlusion, the resting heart rate, left ventricular systolic and end-diastolic pressures, and dP/dt were unchanged. The resting end-diastolic segment length in the LCCA area was increased by 6.6% (p less than 0.05). On histologic examination, there was a disproportionate increase in myocardial cell size in the LCCA area compared with the area perfused by the left anterior descending coronary artery (LAD) (18.2 mu vs 15.4 mu, p less than 0.05). In an additional similarly instrumented five dogs, myocardial cell size in the LCCA and LAD areas was comparable (14.2 mu vs 14.0 mu, p = NS). We conclude that the repeated brief ischemic episodes induce regional myocardial hypertrophy confined to the ischemic area.

Analysis of Variance↗
PubMed1989

Changes in isovolumic segment shortening following acute coronary occlusion: disproportionate effects of anterior versus posterior ischemia.

We evaluated the changes in left ventricular pressure and isovolumic segment shortening in both the ischemic and nonischemic areas following acute coronary occlusion in 12 conscious dogs instrumented for the measurement of subendocardial segment lengths perfused by the left circumflex coronary artery and left anterior descending coronary artery, and left ventricular pressure. An externally inflatable pneumatic occluder was placed around the left circumflex coronary artery. In 6 dogs, another occluder was installed around the proximal left anterior descending coronary artery. Under the resting conditions, the isovolumic segment shortening in the areas supplied by the left anterior descending coronary artery and the left circumflex coronary artery were 2.1 +/- 0.5% (SE) and -0.1 +/- 0.5% (P less than 0.01; versus values in the area of the left anterior descending coronary artery), respectively. During a 1-min occlusion of the left circumflex coronary artery, the isovolumic shortening in the anterior segment increased to 3.8 +/- 0.5% (P less than 0.001; versus values in the basal state), while the posterior segment produced isovolumic elongation (-2.2 +/- 0.5%, P less than 0.001; versus values in the basal state). By contrast, during a 1-min occlusion of the left anterior descending coronary artery, the extent of isovolumic bulge in the anterior segment and the augmentation in the isovolumic shortening in the posterior segment was less prominent compared with the occlusion of the left circumflex coronary artery.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

Free vascularized osteoonychocutaneous flap for reconstruction of the distal phalanx of the fingers.

The "twisted toe flap" offers a solution for reconstruction of the distal phalanx of the fingers; however, a major problem with this method is that the second donor toe must be sacrificed. Two clinical cases are reported in which free vascularized "osteo-onychocutaneous" flaps modified wrap-around flaps were successfully used. The use of the free vascularized osteo-onychocutaneous flap is suggested as a superior method of reconstruction for treating distal phalangeal loss in the fingers.

Adolescent↗