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Biomedical subjects

A Takeuchi

Publications and source records attributed to A Takeuchi.

At least 253 records · Page 14Linked to original sources
PubMed1990

Heterogeneity of RNP and Sm autoantigens in relation to the cell sources and the activated state of the cells.

The extracts of rabbit thymus (RTE), HeLa cells, human histiocytic lymphoma cell line U-937, human promyelocytic cell line HL-60, Ehrlich ascites tumor cells (EACs), and peripheral white blood cells (WBCs) were tested for their composition, molecular weight, and amount of Sm and RNP autoantigens on immunoblotting. The molecular weight of the so-called 68 kDa U1 RNP antigen, which is associated with mixed connective tissue disease (MCTD), was 64.5 kDa in RTE, 62.5 kDa in HeLa cells and HL-60 cells, and 59 kDa in WBCs. Surprisingly, in both WBCs and U-937 cells, the main protein band bearing the 68 kDa U1 RNP antigenic determinants was 30.5 kDa in molecular weight, which was confirmed using antibodies purified by affinity chromatography. After stimulation with phytohemagglutinin (PHA), there was in the human lymphocytes a diminished amount of the 30.5 kDa protein and simultaneously an increased synthesis of several proteins of higher molecular weight, especially the 57 kDa protein bearing the 68 kDa antigenic determinants. The concentrations of the A, B/B', C, D, and E proteins also increased with PHA stimulation. Our results indicate that the expression of Sm and RNP autoantigens may depend on the cell source as well as the activated state of cells. These differences should be taken into consideration in the detection of anti-RNP and anti-Sm antibodies by immunoblotting.

Animals↗
PubMed1990

Right ventricular myocardial infarction and late cardiac tamponade due to right coronary artery aneurysm--a case report.

Coronary artery aneurysm is a relatively rare disease, which may cause angina, myocardial infarction, or sudden unexpected death due to thrombosis, embolization or rupture. This report describes a case of a 46 year old male who suffered an inferior myocardial infarction with right ventricular involvement, third degree atrioventricular block, cardiogenic shock and late cardiac tamponade, all caused by a right coronary artery aneurysm. He was successfully treated with emergency coronary artery bypass grafting. A review of the literature is also given to emphasize the importance of prompt recognition and correct management of the coronary artery aneurysm.

Cardiac Tamponade↗
PubMed1990

Simultaneous coronary and abdominal aortic surgery--a report of two cases.

Myocardial infarction is a major cause of operative mortality following abdominal aortic surgery. For this reason, routine coronary angiography and, if indicated, coronary revascularization prior to aneurysm repair is recommended. Nevertheless, some controversy still exists concerning the risks of aneurysm rupture and myocardial ischemic events when repair or coronary surgery is staged. This report describes two successful cases of simultaneous surgery for an expanding aneurysm and severe coronary artery disease, emphasizing the usefulness of gastroepiploic artery grafting in such cases.

Aged↗
PubMed1990

Comparison of prostacyclin production of human gastroepiploic artery and saphenous vein.

The prostacyclin production of the gastroepiploic artery (GEA) and saphenous vein (SV) were studied in 5 patients undergoing coronary artery revascularization. The GEA produced 90.0 +/- 11.9, 132.4 +/- 13.7, and 191.1 +/- 21.8 pg/mg tissue (mean +/- standard error of the mean) of 6-keto-prostaglandin F1 alpha (prostacyclin metabolite) after 2.5, 5.0, and 10.0 minutes, respectively, of incubation in Krebs-Henseleit buffer at 37 degrees C. The SV produced 39.8 +/- 7.0, 66.7 +/- 9.1, and 123.6 +/- 15.1 pg/mg tissue of 6-keto prostaglandin F1 alpha after 2.5, 5.0, and 10.0 minutes, respectively, of incubation. The GEA produced significantly more 6-keto-prostaglandin F1 alpha than SV at all three sampling times up to ten minutes of incubation (p less than 0.01). Prostacyclin is a potent vasodilator and an inhibitor of platelet aggregation. Prostacyclin production by the internal mammary artery was reported to be much higher than that of SV, and the patency rate of internal mammary artery grafts is reported to be better than that of SV grafts in coronary artery revascularization. Therefore, our results suggest that the patency rate of GEA grafts may be better than that of SV grafts in coronary artery revascularization. The GEA is a promising and excellent graft from the biochemical point of view.

6-Ketoprostaglandin F1 alpha↗
PubMed1990

Free arterial graft as internal mammary artery-Y complex.

Because of excellent surgical results obtained with in situ internal mammary artery grafts, recent efforts have been made to extend the use of arterial conduits. In this study 2 cases of coronary revascularization using free internal mammary artery and gastroepiploic artery grafts as an internal mammary artery-Y complex are described. We believe that complete revascularization with only arterial conduit can be achieved more widely by using this technique.

Aged↗
PubMed1990

Pharmacological response of internal mammary artery and gastroepiploic artery.

Pharmacological response of coronary artery bypass conduit is of great importance. This study was designed to clarify the contractile properties of internal mammary artery and gastroepiploic artery obtained from coronary revascularization. The response to ergonovine, serotonin, and phenylephrine was examined by isometric contraction recording apparatus. The concentration-response relation of both internal mammary artery and gastroepiploic artery to ergonovine, serotonin, and phenylephrine showed similar sigmoid curves. There were no significant differences in developed tension between internal mammary artery and gastroepiploic artery at any concentration for any agent. There were no significant differences in the 50% effective dose value for any agent between internal mammary artery and gastroepiploic artery. Internal mammary artery and gastroepiploic artery are reported to be similar in terms of size, flow capacity, and freedom from atherosclerosis. This study shows their equivalence from a pharmacological viewpoint.

Arteries↗
PubMed1990

Easy dissection of hard and thickened pericardium on constrictive pericarditis.

The keys to successful pericardiectomy for constrictive pericarditis are early operation and as complete a pericardiectomy as possible. With the high-speed burr it is easy and safe to dissect the calcified pericardium and define the epicardium even in a small operative field such as the inferior or posterior portion of the heart. This method has the important ability to perform very complete pericardiectomy.

Adult↗
PubMed1990

Relationship between age-adjusted heart rate and anaerobic threshold in estimating exercise intensity in diabetics.

We compared heart rates at the anaerobic threshold (AT) with age-adjusted heart rates in two groups of diabetics (DMY, mean age 31; and DMO, mean age 48) to ascertain whether the AT is useful for evaluating the intensity of exercise therapy for diabetics. In both the DMY and DMO groups the AT was reached at lower heart rates than in control groups of healthy subjects, indicating that the metabolism of diabetics may become anaerobic if their age-adjusted heart rate is higher than their heart rate at the AT. In this study, 86% of the DMY and 50% of the DMO group had age-adjusted heart rates, at 70% of maximum, that were higher than the heart rates at the AT. Thus, exercise intensity with an age-adjusted heart rate at 70% of maximum may induce anaerobic metabolism in some diabetics. We also studied the relationship between exercise intensity and the glycosylated hemoglobin (HbA1c) level at the AT in order to understand why the heart rate at the AT in diabetics was less than in healthy subjects. Exercise intensity at the AT in both diabetic groups was less than in healthy groups, and so did not increase the heart rates. Both exercise intensity and the heart rate at the AT were inversely related to the HbA1c level, suggesting that HbA1c may be important for keeping low the exercise intensity and the heart rate at the AT. As far as possible, we excluded cardiovascular autonomic neuropathy, so that it could not explain the mechanism.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Effects of osmolality on water, electrolytes and VFAs absorption from the isolated ruminoreticulum in the cow.

Effect of the osmolality on the absorption of water, electrolyte and VFAs from the isolated ruminoreticulum under normal feeding condition were investigated in a series of the study to evaluate the rumen as a potential site of absorption in oral fluid therapy of adult cattle. Thirty of 40 l of the test solutions with varying osmotic pressure (100, 200, 300 and 500 mosmol/L, pH 6.8) were prepared using different concentrations of electrolytes and VFAs. These were infused into the isolated and emptied ruminoreticulum, and the absorption rate of water and each components were studied for 3 hrs. Marked absorption of water was observed with solutions more hypotonic than rumen fluid, the extent of which was more extensive with less osmotic pressure; the absorption rate as high as 47.6% was obtained with a solution 100 mosmol in osmotic pressure. When hypertonic solution (500 mosmol/L) was infused, however, water was transported on the contrary from the blood to the rumen. Absorption rates of electrolytes such as Na, K and Cl were increased according to the elevation of osmolalities and their concentrations in the test solutions. VFAs were also absorbed in large quantities (23.9-74.5%) in any test solutions, though the absorption rates were significantly decreased with the elevation of osmolalities. These results may indicate that the ruminal wall has a high absorptive function for water, electrolytes and VFAs when the osmolalities and the concentration of solutes in the ruminal fluid are maintained within a certain range. Furthermore, it is thought that they may work as a rational support for a possible oral fluid therapy even in adult cows.

Acetates↗
PubMed1990

Effects of organic Ca antagonist, diltiazem, on neuromuscular transmission.

The effects of the organic "Ca antagonist" diltiazem on the frog neuromuscular junction was investigated. The addition of diltiazem to the bath solution increased the frequency of spontaneous miniature endplate potentials (MEPPs) and quantal content. The amplitude of the endplate current (EPC) recorded from a d-tubocurarine-blocked endplate was significantly decreased by diltiazem (20-200 microM). However, the amplitude of miniature endplate current (MEPC) was relatively unchanged by diltiazem. The same degree of decrease in the decay time constant was observed in both EPC and MEPC. ACh potentials induced by repetitive iontophoresis were depressed gradually by low concentrations of diltiazem (2, 5 microM), suggesting enhanced desensitization. Using a patch-clamp method, the effects of diltiazem on ACh-activated single current in chick cultured myotubes were examined. The addition of diltiazem to the bath solution shortened the mean open time in a dose-dependent manner between 10 and 50 microM. The voltage-dependence of mean open time disappeared in the presence of diltiazem, with little change in the channel conductance. The present experiments suggest that diltiazem acts on the ACh-activated channel as an open channel blocker.

Acetylcholine↗
PubMed1990

[Magnetocardiographic localization of an accessory pathway in patients with WPW syndrome].

The usefulness of magnetocardiography (MCG) in determining the location of an accessory pathway (Kent bundle) was examined by the isomagnetic map at the time of a delta wave, and by gated magnetic resonance imaging (MRI). MCG was performed at 36 points on the anterior chest wall in eight cases with Wolff-Parkinson-White (WPW) syndrome using a SQUID (superconducting quantum interference device) system with the second derivative gradiometer. Based on these records, isomagnetic maps during the QRS and T waves were constructed, and the depth of the accessory pathway from the coil was calculated mathematically. The locations of the accessory pathways were estimated using these data and the MRI findings. The locations of the accessory pathways thus determined were compared with findings obtained by body surface maps. A dipole directed towards the left was deduced, because the maximum was located more superiorly than the minimum in an isomagnetic map 10-40 msec after onset of the delta wave in cases with WPW syndrome, indicating an accessory pathway to be located in the right ventricle. A dipole directed towards the right was deduced, because the maximum was located more superiorly than the minimum in an isomagnetic map 10-40 msec after onset of the delta wave of cases with WPW syndrome indicating an accessory pathway to be located in the left ventricle. Assuming the electric current source is a single dipole, the location of a current dipole might be determined by positions of the maximum and the minimum in the isomagnetic maps. In the present study, the locations as determined by analysis of the isomagnetic map 40 msec after onset of the delta wave and the gated MRI were concordant with the findings obtained by body surface isopotential maps. Furthermore, some cases showed two opposing dipoles on the isomagnetic map at the peak of the T wave in lead II of the standard ECG leads; one directed to the left expressing normal repolarization; the other directed to the right presumably expressing repolarization of the myocardium which was excited by an impulse via the accessory pathway. The location of the current dipole as determined by analysis of the isomagnetic map at the peak of the T wave in lead II was nearly the same as the position of the current dipole as determined by analysis of the isomagnetic map 40 msec after onset of the delta wave.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1990

[Monoclonal antibody analysis of glomerular, tubulo-interstitial infiltrating immune cells in various glomerulonephritis].

To investigate the role of cell-mediated immunity (CMI) in glomerulonephritis (GN), we identified the infiltrating immune cells both within the glomerulus and in the interstitium. Frozen sections from 103 patients with various forms of GN: 10 with minor glomerular abnormality (MGA) as control, 10 with minimal change nephrotic syndrome (MCNS), 10 with membranous nephropathy (MN), 9 with focal glomerulosclerosis (FGS), 30 with IgA nephropathy (IgAN), 22 with acute post streptococcal glomerulonephritis (APSGN), and 2 with rapidly progressive glomerulonephritis (RPGN) were examined using monoclonal antibodies (MoAb) by indirect immunoalkaline-phosphatase labelling. In most glomerulonephritis, monocyte/M phi and helper/inducer T cells were predominantly infiltrating in the interstitium, but intraglomerular infiltration was rare, except for APSGN. This interstitial infiltration increased proportionally to the level of serum creatinine, and was most prominent in RPGN. Apparently different distribution was seen in APSGN, that is, prominent increase in total number of intra-glomerular monocyte/M phi infiltration with slightly increased T cells. The change was correlated with time after onset; namely the more leucocytic infiltration was observed when the tissue was taken earlier. These data suggest that in APSGN, monocyte/M phi accumulate in glomeruli via cell mediated immunity in addition to humoral immune mechanism resulting in glomerular hypercellularity, whereas in most chronic glomerulonephritis interstitial leucocyte infiltration, particularly helper T cells and monocyte/M phi may play an important role in the progression of glomerulonephritis.

Adolescent↗
PubMed1990

[Contractile properties of coronary artery bypass conduit--comparison between saphenous vein and internal mammary artery].

This study was designed to examine the response of coronary artery bypass conduit to serotonin, phenylephrine, and ergonovine as provocation agents of vasoconstriction. Saphenous veins (SV) and internal mammary arteries (IMA) were obtained during coronary artery bypass grafting (CABG), and their contractile properties were measured using isometric contraction recording apparatus. Both SV and IMA showed sigmoid contraction curves indicating dose dependence to ergonovine, serotonin, and phenylephrine. The concentration-response relations for phenylephrine showed a similar curve in both SV and IMA, however, those for ergonovine and serotonin showed a leftward shift in SV compared with IMA. Half maximum effective dose for ergonovine and serotonin were less in SV than IMA. From these results, it was suggested that "perioperative spasm" during CABG might occur not only in coronary arteries but also in the graft conduit itself. Graft spasm might be a possible mechanism for occlusion of the bypass graft. In conclusion, greater hyperreactivity of SV compared with IMA in response to ergonovine and serotonin was suggested, so it is concluded that, from this point of view, IMA is more suitable for use in CABG.

Coronary Artery Bypass↗
PubMed1990

[Coronary revascularization for patients requiring steroids. A report of three cases].

Three patients with systemic disease requiring steroids, in whom coronary artery bypass grafting (CABG) was performed, are reported in this paper, Anesthetic problems and operative managements for such patients are also discussed. Patient 1, 57-year-old male with thrombocytosis underwent emergency double CABG using saphenous vein and the Bioflow graft. He discharged with freedom from angina. Patient 2, 59-year-old male with polymyositis who had been receiving steroid for 10 years underwent quadruple CABG using bilateral internal thoracic arteries with sequential technique and the Bioflow graft, but he died of multiple organ failure on 16 days after operation. Postmortem examination revealed that coronary artery sclerosis progressed more severely than we had expected from angiography. All the graft anastomosed were completely patent. Histological examination showed that the saphenous vein was fragile. The pathological changes might be due to steroid administration. On the other hand, arterial grafts were completely normal. Patient 3, 37-year-old male with idiopathic thrombocytopenic purpura who had been on steroids underwent combined triple CABG using internal thoracic artery, gastroepiploic artery and the Bioflow graft and splenectomy. He discharged with freedom from angina and tendency to bleed. Postoperative angiography showed both arterial grafts were well patent and left ventricular wall motion vastly improved. From our experience, a careful consideration of the bypass conduit is a major problem in such patients requiring steroids.

Adult↗
PubMed1990

Cerebral hemodynamics in patients with chronic obstructive carotid disease by rCBF, rCBV, and rCBV/rCBF ratio using SPECT.

To evaluate cerebral hemodynamics, 21 patients with chronic occlusion or severe stenosis of the internal carotid or middle cerebral artery with normal or only lacunar infarction on x-ray CT were studied using single photon emission computed tomography (SPECT). We measured rCBV with 99mTc erythrocytes after rCBF with 133Xe, and calculated rCBV/rCBF. rCBF and rCBV of the 25 affected hemispheres were classified as (a) patients with normal rCBF [type I (n = 7) and type II (n = 3)]; (b) patients with decreased rCBF [type III (n = 6) and type IV (n = 9)]. These two groups then could be subdivided according to findings of rCBV, normal, and increased blood volumes. rCBV/rCBF increased as the cerebral perfusion pressure dropped from type I to type III. In type IV, other situations but cerebral autoregulation could be assumed. rCBV/rCBF signifies vascular mean transit time. Type III (high rCBV/rCBF) assumed as the increased OEF, misery perfusion as reported in PET. We propose rCBF, rCBV and rCBV/rCBF using SPECT can be an index for cerebral circulatory reserve.

Arterial Occlusive Diseases↗
PubMed1990

[Left ventricular rupture following the procedure of percutaneous transluminal coronary angioplasty: a case report].

A 50-year-old man with 90% concentric stenosis at the proximal portion of the left anterior descending artery was tried to be treated with percutaneous transluminal coronary angioplasty (PTCA). The guide wire did not pass through the stenotic portion, and the staining out of coronary artery was recognized. Four hours after the procedure, he fell to shock status with a sign of electro-mechanical dissociation. An emergent operation confirmed the left ventricular rupture. Repair of the tear and saphenous vein bypass to the left anterior descending artery were performed rapidly, however, he was not weaned from cardiopulmonary bypass. Close communication between cardiologist and surgeon, and immediate surgical back up are essential for saving these patients from severe ischemic events following PTCA failure.

Angioplasty, Balloon, Coronary↗