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Biomedical subjects

Y Yagi

Publications and source records attributed to Y Yagi.

At least 19 recordsLinked to original sources
PubMed1992

Importance of left ventricular function and systolic ventricular interaction to right ventricular performance during acute right heart ischemia.

To determine whether modulation of systolic ventricular interaction influences right ventricular performance during right heart ischemia, the effects of septal ischemia and inotropic stimulation were studied in 15 dogs in an open chest preparation. Right coronary branch occlusions led to right ventricular dilation and free wall dyskinesia, reversed septal curvature and reduced left ventricular diastolic volume. In systole, the septum thickened but bulged paradoxically into the right ventricle generating an active but depressed right ventricular systolic pressure (28.9 +/- 5.5 to 22.1 +/- 4.5 mm Hg), with associated decreases in right ventricular stroke work (5.66 +/- 0.94 to 1.92 +/- 0.53 g.m/m2) and left ventricular systolic pressure (123 +/- 11 to 80 +/- 10 mm Hg). Septal ischemia induced systolic septal thinning, left ventricular dilation and decreased left ventricular systolic pressure (80 +/- 10 to 55 +/- 10 mm Hg) and stroke work. Although the extent of paradoxic septal displacement increased, there were further decrements in right ventricular systolic pressure (22.1 +/- 4.5 to 18.7 +/- 4.3 mm Hg) and stroke work (1.92 +/- 0.53 to 0.7 +/- 0.2 g.m/m2). Dopamine infusion augmented left ventricular free wall contraction and increased left ventricular systolic pressure (55 +/- 10 to 172 +/- 17 mm Hg) and stroke work. Although systolic septal thinning persisted, the extent of paradoxic septal displacement increased strikingly and, despite continued right ventricular free wall dyskinesia, right ventricular systolic pressure increased (18.7 +/- 4.3 to 39.6 +/- 6.2 mm Hg) as did right ventricular stroke work (0.7 +/- 0.2 to 7 +/- 1.6 g.m/m2).(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1992

Increase in serum cardiac myosin light chain I associated with elective percutaneous transluminal coronary angioplasty in patients with ischemic heart disease.

Changes in serum myosin light chain I (MLCI) due to elective percutaneous transluminal coronary angioplasty (PTCA) were studied after PTCA (0, 8 and 48 hours) in 57 patients with old myocardial infarction (MI group) and 20 patients with angina pectoris (AP group). The AP group showed no increase after PTCA. In contrast, in the MI group there were 16 patients in whom MLCI at 48 hours was increased by 1.0 ng/ml or more (MI1 group) and another group of 41 patients who showed no increase in MLCI (MI2 group). The MI1 group had a significantly higher incidence of (1) non-Q wave myocardial infarction (62.5% vs. 17.1%, p < 0.01), (2) 99% stenosis of a coronary artery (50.0% vs. 12.2%, p < 0.01), and (3) redistribution in a hypoperfusion area found in the delayed image of resting thallium-201 (201Tl) myocardial scintigraphy (85.7% vs. 15.8%, p < 0.01). The left ventricular ejection fraction (LVEF) was significantly improved in the MI1 group, 3 to 4 months later (from 0.49 +/- 0.12 to 0.58 +/- 0.11, p < 0.01), in contrast to the patient of MI2 group who did not show any improvement. The AP group was not considered to have a bulk of myocardium impaired enough to show a release of MLCI due to PTCA-associated transient coronary occlusion. In the MI1 group, however, MLCI was probably released from the chronically under-perfused, but still salvageable, portion of the myocardium. This is consistent with the improvement in LVEF observed 3 to 4 months after the relief of severe coronary stenosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Angina Pectoris↗
PubMed1992

Estimation of right ventricular volume by modified echocardiographic subtraction method.

To evaluate the accuracy and clinical utility of right ventricular volume estimated by a modified echocardiographic subtraction method versus Krebs' original subtraction method, an experiment was performed on hearts excised from 25 animals (dogs, pigs, and cows) followed by a clinical study of 41 patients with heart disease. Right ventricular volume was measured by subtracting the left ventricular volume from that of the whole heart based on echocardiographic apical two- and four-chamber views by means of the area-length method. In the animal heart study, the coefficient of variation between the right ventricular volume estimated by the modified method and the true volume was +/- 13%. The regression equation was y = 0.94x + 4.15 (r = 0.987, p less than 0.001) and showed good correlation, whereas the right ventricular volume obtained by the original method underestimated the true volume (coefficient of variation = +/- 25%, y = 0.59x + 1.11; r = 0.976, p less than 0.001). In the clinical study, the coefficient of variation between right ventricular volume estimated by the modified echocardiographic method and RV volume estimated by radionuclide ventriculography was +/- 15%. The regression equation was y = 0.80x + 13.3 (r = 0.935, p less than 0.001). This correlation was better than that obtained by the original method (coefficient of variation = +/- 16%), where the regression equation was y = 0.60x + 2.43 (r = 0.888, p less than 0.001). Thus the accuracy of the modified subtraction method was validated, and this method showed a better correlation than the original method both experimentally and clinically.

Adolescent↗
PubMed1992

Plasma high density lipoprotein in anemic cattle infected with Theileria sergenti.

Changes in plasma concentration of lipid composition were analysed in cattle with anemia due to Theileria sergenti infection. Plasma levels of phospholipids, cholesterol, free cholesterol, high density lipoprotein cholesterol, and vitamin E decreased to 40-67% of the pre-infection levels, corresponding to the decrease of PCV due to the infection. However, no definite changes were detected in plasma level of triglyceride. By gradient centrifugation, it was confirmed that lipid components, other than triglyceride, occur in high density lipoprotein (HDL) and these decreases lowered the HDL value. There was no correlation between this phenomenon and liver function. As similar changes in lipid composition were also observed in phlebotomized calves, it was considered that this phenomenon might partially depend on the acceleration of erythropoiesis as a reaction to anemia caused by T. sergenti infection.

Anemia↗
PubMed1992

[An experimental study on the determinants to the effects of self-affirmation].

The purpose is twofold: first to examine whether an experience that affirms a valued aspect of the self eliminates the negativity of failure and second, to identify what is the most effective condition of self-affirmation. A 2 x 3 factorial design was employed: Immediately after having failed and prior to rating the beneficialness of failure experience, 72 subjects were allowed to affirm the real-self that they had built up, or the pseudo-self made by the experimenter. The situation of self-affirmation was (1) that subjects affirmed the self in private or (2) that the experimenter also affirmed the subject's self or (3) that the experimenter added information of another one who had the same aspect of self the subjects had affirmed. The self-affirmation effect was most clear-cut, when the real-self was affirmed, and was also affirmed by the experimenter. This effect was especially pronounced for high self-esteem subjects. Joint effects of high self-esteem, clearer real-self, and its publicity elevated level of self-affirmation.

Adult↗
PubMed1992

Experience and present status of telepathology in the National Cancer Center Hospital, Tokyo.

The optical fiber high definition television (HDTV) live image system with a remote control microscope is an ideal telepathology system. Diagnostic accuracy with this system is high enough for pathology consultation. However, it is very expensive to set up. The integrated services digital network (ISDN)-HDTV still image system using public telephone lines presently available in Japan INS 64 (64 kb/s), is not suitable for frozen section diagnosis and diagnosing difficult lesions. However, it functions very well for cytology consultation. When INS 1500 (1.5 Mb/s) becomes available in practice, it can substitute the optical fiber-HDTV live image system in terms of cost and efficacy. Pathologists must become accustomed to making diagnosis from images on the monitor. They must be very careful in making diagnosis, when images are transmitted from institutions without pathologists, since selection error may occur at the time of frozen section and at the time of transmission of images.

Cancer Care Facilities↗
PubMed1992

[False aneurysm formation during the chronic phase of myocardial infarction at the margin of a previously-detected true aneurysm].

The patient was a 59-year-old man who had acute extensive anterior myocardial infarction in October, 1989. One month later, he was transferred to Kyoto University Hospital and underwent cardiac catheterization. Left ventricular aneurysm and significant stenosis in the proximal portion of the left anterior descending artery were documented. Because he experienced chest pain on slight exertion accompanied by a slight increase in the depth of the negative T wave on electrocardiogram, percutaneous transluminal coronary angioplasty (PTCA) was performed. Thereafter, chest pain disappeared, and the patient was discharged. Three months later, he was re-admitted to Kyoto University Hospital for a repeat cardiac catheterization after PTCA. PTCA site was found to be restenosed, and a small diverticulous aneurysm was found at the margin of the previously-detected ventricular aneurysm. As the diverticulous aneurysm was considered likely to precipitate the ventricular aneurysm into rupture, expeditious left ventricular aneurysmectomy was performed to prevent cardiac rupture. Ventricular aneurysms, common complications in myocardial infarction, are of two types, either true or false. Most aneurysms develop during the acute phase of myocardial infarction, and rupture of true aneurysms during the chronic phase of myocardial infarction rarely occurs. However, in the present case, a small diverticulous aneurysm, which was not demonstrated at the initial cardiac catheterization, developed during the chronic phase of myocardial infarction. Pathological examination revealed that the diverticulous aneurysm was a false aneurysm due to incomplete rupture. When the common pathogenesis of ventricular aneurysms in myocardial infarction is considered, the present report might represent an extraordinary rare case.(ABSTRACT TRUNCATED AT 250 WORDS)

Aneurysm, Ruptured↗
PubMed1992

[Studies on motor neuron disease with cranial magnetic resonance imaging].

The present study was performed to examine the pyramidal tracts of the brain in both 51 normal subjects (21 male and 30 female subjects; mean age of 43.5 +/- 16.1 years) and 12 patients with motor neuron disease (6 male and 6 female patients; mean age of 57.4 +/- 7.9 years), using the magnetic resonance imaging (MRI). The 12 patients with motor neuron disease (MND) comprised 7 suffering from spinal progressive muscular atrophy (SPMA) and 5 from amyotrophic lateral sclerosis (ALS). The MRI used in this study was of both short spin echo and long spin echo sequence. Of the 52 normal subjects, 24 of them (47%) had the T2 prolonged small areas (high signal intensity areas) at the posterior limb of internal capsule. These findings were not found in the normal subjects over fifty years old. No similar finding was detected in the pyramidal tracts except the posterior limb of internal capsule. On the other hand, 8 patients with MND (67%) proved to have the high signal intensity areas in the pyramidal tracts. Moreover, these high intensity areas were extended from the crus cerebri to corona radiata in 7 patients (58%). In all patients with ALS, these areas were extended in whole areas of the pyramidal tracts, and the similar findings were also found in two patients with SPMA. These findings were demonstrated to be more extensive than those in the normal subjects. The results thus obtained warrant us to conclude that cranial MRI is useful to detect the degeneration of the pyramidal tracts of MND patients.

Adolescent↗
PubMed1992

[Surgical versus nonsurgical therapy of fatal tachyarrhythmias].

Interventional treatment is necessary for fatal drug-refractory tachyarrhythmias. Thirty-three, 33 and 16 patients (pts) with intractable ventricular tachycardia (VT) and/or fibrillation (VF) were managed with cryosurgery (CS), electrical catheter ablation (EA) and implantable pacer-cardioverter-defibrillator (PCD), respectively. Seventy-six and 43 pts with sudden death risk in the Wolff-Parkinson-White syndrome (WPW) also underwent CS and EA, respectively. CS success rates were 85% in VT/VF and 95% in WPW. Those of EA were 48% and 81%, respectively. EA success rates were 100% (6/6) in idiopathic verapamil-sensitive VT originated from LV, 0% (0/2) in VT following TOF repair and 0% (0/2) in idiopathic VT originated from right ventricular outflow tract. A new VT developed in 5 of 11 pts with arrhythmogenic right ventricular dysplasia (ARVD) following EA. PCD was effective for prevention from sudden death in idiopathic VF and pleomorphic VT. All of pharmacologic, EA and CS therapies were relatively effective in ischemic heart disease without low EF. In conclusion, the decision of VT-VF therapy may be affected by the underlying heart disease and EA may be established as an initial intervention for high risk WPW.

Adult↗
PubMed1992

[Surgical treatment of ventricular tachycardia after total correction of tetralogy of Fallot].

A 38-year-old man with total repair of tetralogy of Fallot at the age of 16 suffered from paroxysmal ventricular tachycardia. His first attack of sustained ventricular tachycardia was recognized at the age of 37 and it was refractory for medical therapy. Electrophysiologic study demonstrated two morphological types of clinical ventricular tachycardias, one originated from the outflow tract of the right ventricle and the other from the area around the patch for closure of ventricular septal defect. He underwent cryosurgical ablation for ventricular tachycardia and patch-closure for residual shunt of ventricular septal defect following the failure of electrical ablation. All of clinical ventricular tachycardias disappeared postoperatively without antiarrhythmic drugs.

Adult↗
PubMed1992

[A case of gallbladder cancer with marked response to EAP treatment].

A case of unresectable gall bladder cancer due to multiple metastasis was dealt with EAP (VP-16, ADM, CDDP) treatment. The case was a 49-year-old male who was admitted to the hospital with a 3 cm sized umbilical tumor. After 2 cycles of the treatment, the tumor size significantly decreased and the symptoms diminished. In parallel, the symptoms from bone metastasis and dissemination also disappeared. As for tumor markers, CA 19-9 indicated 5151 U/ml, fell down to the normal range after the treatment. In this case, the efficacy of EAP treatment to the primary gall bladder carcinoma was undetectable, because of the difficulty of elucidation of the primary site by diagnostic images. However, all data suggested that EAP treatment was effective to the advanced unresectable gallbladder cancer, at least to its metastatic sites.

Adenocarcinoma↗
PubMed1991

Right atrial ischemia exacerbates hemodynamic compromise associated with experimental right ventricular dysfunction.

To determine the importance of right atrial function with acute right ventricular dysfunction, sequential right ventricular and right atrial ischemia were induced in 15 dogs. Right ventricular ischemia resulted in right ventricular free wall dyskinesia, right ventricular dilation by ultrasound, elevated right ventricular filling pressure and paradoxic septal motion. There were decrements in right ventricular systolic pressure (28.9 +/- 5.5 to 25.5 +/- 4.6 mm Hg) (p less than 0.05 for these and all subsequent values) and stroke work (5.66 +/- 0.94 to 2.66 +/- 0.62 g.m/m2), resulting in reductions in left ventricular preload, systolic pressure (123 +/- 11 to 97 +/- 12 mm Hg) and stroke volume (24.2 +/- 4.3 to 19.1 +/- 5.2 ml). Right atrial contractility was augmented, as indicated by increases in peak A wave amplitude (ratio of peak A wave to mean right atrial pressure 1.22 +/- 0.02 to 1.46 +/- 0.3) and right atrial stroke work (0.11 +/- 0.02 to 0.25 +/- 0.05 g.m/m2). Right atrial ischemia depressed right atrial contraction, as indicated by decreased A wave amplitude (ratio of peak A wave to mean right atrial pressure 1.46 +/- 0.3 to 1.04 +/- 0.2) and stroke work (0.25 +/- 0.05 to 0.04 +/- 0.01 g.m/m2).(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of Variance↗
PubMed1991

Decrease in erythrocyte survival in Theileria sergenti-infected calves determined by non-radioactive chromium labelling method.

Pathogenesis of anemia in the calves infected with Theileria sergenti was investigated from the viewpoint of erythrocyte survival decrease in the circulating blood. For investigation of erythrocyte survival a method of erythrocyte labelling with non-radioactive chromium (50Cr) was utilized. It was found that (1) the erythrocyte survival decreased markedly in the T. sergenti-infected calves compared with that in the uninfected calves; the survival rate of 25.7% for infected calves and 86.0% for uninfected ones on the fourth day after re-introduction of the labelled erythrocytes into the original donors, and that (2) the survival of non-parasitized erythrocytes in the infected calves was also decreased, which indicates no obvious relationship between parasitism and decrease in survival of erythrocytes.

Anemia↗
PubMed1991

[Coronary artery bypass graft stenosis suspected to be due to hemostatic agents: a case report].

A 66-year-old man had a CABG with a saphenous vein graft. During the surgery, oxidized cellulose and fibrin glue were used and left in place for hemostasis. Six months after the surgery, the first postoperative CAG was performed and a stenosis of the coronary bypass graft near the proximal anastomosis was found. The first PTCA was done and the stenosis was released. Re-stenosis was observed at the same site one year after the first PTCA and a second one was performed. Five years and nine months after the surgery, the patient started complaining of severe chest pain even though he was receiving medication. Graft stenosis at the same site was observed by CAG. A cyst 3 cm in diameter, with irregular wall thickness was found near the proximal portion of the bypass graft. Resection of the cyst and re-CABG was performed uneventfully. Microscopically, the cyst consisted of fibroblasts, small vessels, collagen fiber and giant cells and was diagnosed as granuloma. In the giant cells, oxidized cellulose fiber was observed. No comparable cases have been reported in the literature. Topical hemostatic agents were discussed.

Aged↗