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Biomedical subjects

Y Yagi

Publications and source records attributed to Y Yagi.

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

Feasibility of closed heart discrete cryomodification of atrioventricular conduction. Electrophysiologic effects in the canine heart.

Discrete cryosurgical modification of atrioventricular conduction abolishes refractory atrioventricular node reentry tachycardia with preservation of antegrade atrioventricular nodal conduction. This procedure presently requires cardiopulmonary bypass. To modify atrioventricular conduction without cardiac surgery, we evaluated the electrophysiologic effects of cryolesions applied to the peri-nodal area in the closed heart in 16 dogs before operation, during cryothermic exposure, and at 1 hour and 3 hours after operation. The electrophysiologic effects were evaluated in 10 of the 16 dogs at 2 weeks postoperatively. The dogs were given general anesthetics, and a cryoprobe was introduced into the right atrial cavity through the right atrial appendage. Cryolesions (-60 degrees C) were placed at nine to eleven preselected points around the perinodal area guided by electrodes on the tip of the cryoprobe. Postoperatively, there were significant prolongations of the atrio-His interval, Wenckebach's point, effective refractory period, and functional refractory period of the atrioventricular node. Atrial echo beats were eliminated or decreased in frequency. There was also a significant increase in retrograde ventriculoatrial conduction time. In the long-term observation period the atrio-His intervals remained significantly prolonged in comparison with the preoperative values, the atrial echoes progressively decreased, and ventriculoatrial conduction was absent in five of seven animals. A serendipitous atrioventricular node reentry tachycardia that was inducible in one animal with dual atrioventricular node conduction pathways was successfully eliminated and was not inducible at 2 weeks postoperatively. Complete atrioventricular block occurred during attempts to produce greater atrio-His prolongation in three of the 16 animals and persisted in two for the 2-week period of observation. Closed heart intracardiac cryomodification of atrioventricular conduction is feasible, with the cryoprobe in normothermic blood, producing changes in atrioventricular conduction similar to the open cardiac procedure.

Animals↗
PubMed1991

[The automatic implantable cardioverter defibrillator--clinical experience in patients with life-threatening ventricular tachyarrhythmias].

Five patients (pts) with life-threatening ventricular tachyarrhythmias (idiopathic VF; 2 pts, Torsade de pointest; 1 pt, VT/VF after valve replacement; 2 pts) underwent surgical treatment of the automatic implantable cardioverter defibrillator (AICD). Implantation of an AICD was indicated for patients who survived circulatory arrest due to documented VT and/or VF. The patient should be medically refractory or medical treatment precluded by hemodynamic instability; other surgical treatment should not be possible. We selected myocardial electrode for sensing and small and large patch electrodes for defibrillating. VF/VT was induced 1 to 6 times for the measurement of defibrillation threshold (DFT). In all of our pts, the AICD appropriately discharged at postoperative EPS. In three of pts, the AICD discharged within the postoperative hospital phase, in two because of sinus tachycardia during treadmill test and restored sinus rhythm after non-sustained VT. As for complications, in one pt. with severe LV dysfunction, incessant form of VT/VF occurred after DFT testing and LV assist circulation and IABP were needed. In two pts, inappropriate discharge and in two, pericarditis were recognized postoperatively. It was considered that this system was effective for the treatment of life-threatening ventricular tachyarrhythmias but strict indication was necessary because of unsolved problems.

Adult↗
PubMed1990

Clearance of argininosuccinate synthetase from the circulation in acute liver disease.

Argininosuccinate synthetase is an enzyme which has been found to be a specific marker for liver damage. In patients with acute hepatitis, the concentration in serum increases at the onset of the disease, but later decreases more quickly, so that the time required for normalization is shorter than that of alanine aminotransferase. This is probably caused by rapid clearance of argininosuccinate synthetase from the serum. Rapid clearance was demonstrated in experimental animals given purified enzymes intravenously. Argininosuccinate synthetase disappeared from the serum with a half life of about 15 min, while the half lives of alanine aminotransferase and aspartate aminotransferase were 4 and 5 h, respectively, under the same conditions.

Acute Disease↗
PubMed1990

Hemodynamic importance of systolic ventricular interaction, augmented right atrial contractility and atrioventricular synchrony in acute right ventricular dysfunction.

To delineate the determinants of right ventricular performance with acute right ventricular dysfunction, surgical electrical isolation of the right ventricular free wall was produced in 13 dogs. During atrioventricular (AV) pacing, hemodynamic and wall motion measurements were normal. When not paced, the right ventricular free wall became asystolic, resulting in a depressed and bifid right ventricular systolic pressure (33 +/- 5 to 18 +/- 4 mm Hg) and decreased left ventricular systolic pressure (100 +/- 18 to 80 +/- 18 mm Hg) and stroke volume (14 +/- 4 to 10.3 +/- 3.5 ml) (all p less than 0.05). Ultrasound demonstrated right ventricular free wall dyskinesia, increased right ventricular end-diastolic size (155 +/- 13% of control), but decreased left ventricular size (69 +/- 11% of control) (both p less than 0.05). Right atrial pressure increased (5.8 +/- 2.5 to 7.6 +/- 2.8 mm Hg, p less than 0.05) with an augmented A wave and blunted Y descent, indicating pandiastolic right ventricular dysfunction. The septum demonstrated reversed curvature in diastole and bulged paradoxically into the right ventricle during early systole, generating the initial peak of right ventricular pressure and reducing its volume. Later, posterior septal motion coincided with maximal left ventricular pressure and the second peak of the right ventricular waveform. Left ventricular pacing alone led to further decreases in right ventricular systolic pressure and size, left ventricular systolic pressure and stroke volume. The previously augmented A wave was replaced by a prominent V wave. Therefore, when contractility of its free wall is acutely depressed, right ventricular performance is dependent on left ventricular-septal contractile contributions transmitted by the septum.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗