Biomedical subjects
Publications and source records attributed to K Ohishi.
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Discrepancy in coronary stenosis between angiogram and pathological specimen was moderately found. It is of a problem what is meaning by a significant narrowing. Coronary capacity per heart weight markedly reduced in multi-vessel disease and revealed an intimate relationship to sudded death and cardiac failure. Much of sclerosis in the arterial wall was relatively severe in spite of patency in lumen of the terminal artery. Intramuscular arterioles were intact even when severe extramuscular coronary atherosclerosis was seen. Well-developed collaterals were seen in much of multi-vessel disease. Muscle prevervation was relatively good even in the advanced sclerosis. It is reasonable to make an attempt on a newly construction of a vessel to introduce into preserved arteriola with well-developed collateral, and preserved myocardium.
M-mode scan echocardiographic studies of the mitral valve were performed in order to investigate structural architecture of the diseased mitral valve. Structural lesion of the mitral valve was assessed by the echo-pattern change, an increase in number or thickness of the diastolic mitral echo complex. The echo-pattern was classified into 4 grades according to number or thickness of the mitral echoes. The echo-pattern grade correlated with the degree of the structural lesion of 21 surgically excised mitral valves. Clinically, the echo-pattern grade was compared with subsequent operative procedure in 56 cases with pure or predominant mitral stenosis (42 open commissurotomy, 14 valve replacement). Grade I or grade II echo-pattern was a good indicator for mitral commissurotomy. Grade IV pattern was a reliable criterion for valve replacement. Mitral valve replacement should be also considered in cases with grade III pattern, 38% of whom underwent valve replacement. C-E amplitude of the mitral valve was not a useful parameter in assessing the surgical procedure. Thus, the echo-pattern obtained by M-mode scan technique appeared to be of valve in planning the surgical approach for patients with pure or predominant mitral stenosis.
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Experimental studies of aorto-coronary bypass were performed using the technique of distal coronary artery perfusion in 47 dogs to ellucidate the flow characteristics at various grafts and long term fate of grafts up to 440 days after operation. On short term results, early graft occlusion seems to occur within 2 weeks with 6.5 days of mean in Group I and II (free grafts) when inflammatory reaction is most prominent. After 2 weeks patency rate was 65% in Group I and II, more than 80% of patency rate were obtained in Group III. In Group IV (prosthetic grafts), all but few (3 cases) could survive for more than 24 hours. In flow characteristic, artery and vein graft of which diameter is larger than that of the coronary artery can maintain enough the basal flow after ligation of the proximal coronary artery. In Group III (IMA-Circumflex anastomosis group), the internal mammary artery must be large enough to carry the blood to coronary artery lest the graft flow becomes below the basal flow. In Group IV, grafts can carry full flow but long term studies were not done because of early graft occlusion. There are much differences between free artery and vein grafts. In artery graft except IMA proper arterial structure is being kept until 440 days but has arteriosclerotic wall changes similar to human being. On the contrary, almost all free vein grafts have subintimal hyperplasia with collagen deposit and fibrous tissue and still progress after one year. These findings demonstrate that ischemia and hydrauiic effect in the graft must be important factor for the irreversible graft wall changes.
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For the surgical management of Ebstein's anomaly, the preferred operation will be Hardy's procedure, which preserves the patient's valve. However, we have encountered 3 cases of this disease in which the downward displacement of the tricuspid valve was so severe and the functioning right ventricle was so small that Hardy's method could not be adapted without causing tricuspid regurgitation and making the right ventricular chamber more narrow. We treated these patients by replacing the tricuspid valve with an inverted aortic valve with a stent and not plicating the atrialized ventricle. The results have been proved satisfactory through about 7 years' follow-up, suggesting that our technique will be remarkably effective as a radical corrective operation for Ebstein's anomaly with severe intracardiac abnormalities.
We present a 42-year-old female patient who had repeated swelling of the bilateral false cords. The patient complained of dryness of the eyes and oral mucosa, and was diagnosed as having Sjögren's syndrome. She underwent partial resections of the bilateral false cords 4 times in 3 years to evaluate the nature of the disease and to relieve airway obstruction. Histologic examinations revealed severe atrophic changes of the laryngeal glands and cystic dilation of the ducts of the glands, associated with marked lymphocytic infiltration and lymphoid hyperplasia. These findings suggest that the etiology of the swelling of the false cords was related to Sjögren's syndrome.
The effect of acupuncture on the cardiovascular system was studied in 23 healthy males in a cross-over design comparing acupuncture and a placebo pill by measuring skin blood flow and the function of the heart. Acupuncture was found to have a modulatory effect on skin blood flow (correlation coefficient (r) = -0.68; p < 0.0005) and heart rate (r = -0.56; p < 0.005), as well as Blood-Pressure-Heart-Rate-Product (r = -0.70; p < 0.0002). The combination of rest and a placebo pill had no modulatory effect on skin blood flow, but did have a delayed effect on the heart when compared with acupuncture. The results indicate that acupuncture has the ability to enhance the regulatory mechanisms of the cardiovascular system. The possible underlying mechanism is discussed. The findings represent a physiological explanation for the possible utility of acupuncture in maintaining cardiovascular homeostasis in healthy people.
We report the eighth case of surgical removal of a papillary endocardial tumor. The surgical approach was aided by intraoperative two-dimensional echocardiography. The tumor was attached to the chorda tendinea of the mitral valve and was successfully removed via a left atrial approach.
The value of postoperative radiation therapy (RT) was investigated in 77 patients with esophageal cancer resected between 1977 and 1986. Surgical resection was palliative in 13 of these patients. Although seven of them underwent postoperative irradiation to the residual tumor, all of the patients died within one year. Following potentially curative resection performed in 64 patients, 31 patients received 50 Gy of postoperative RT to the lower neck and the mediastinum (group Ia), seven were unable to receive full-dose postoperative RT (group Ib), and 26 were not treated with postoperative RT (group II). The 5-year survival rate estimated by the Kaplan-Meier method was 54% for group Ia, 29% for group Ib, and 33% for group II, with the difference between groups Ia and II being significant (p less than 0.025). The local recurrence rate in the mediastinum was lower in group Ia than in group II. Prophylactic postoperative RT for esophageal cancer is a safe and effective regimen for patients with resected disease.
We report two patients with vasculo-Behçet's disease who had femoral and popliteal aneurysms. The resected aneurysms and occluded distal arteries were studied clinicopathologically. The most interesting features were prominent fibrosis of the adventitia including the surrounding tissue, venous occlusion, perivasculitis and deposits of C3, C4 and immunoglobulins (IgA, IgG and IgM) in the arterial wall and surrounding tissue. These findings indicate that the formation of aneurysm in vasculo-Behçet's disease is caused by destruction of the intimal and outer side of the arterial wall.
Eighty-nine patients received mitral valve replacement with Carpentier-Edwards porcine bioprostheses between 1975 and 1983. Eighty-three patients (93.3%) were followed up after the operation; early death (within one month of operation) occurred in 6 patients and late death in 2 patients. After the operation, 64 survivors (85.3%), who did not require reoperation, exhibited improved symptoms according to the NYHA functional class. Of the 6 patients (6.7%) who required reoperation, 5 patients underwent reoperation 50 to 85 months after the implantation. Pathologically, all the removed valves showed degeneration of collagen and elastic fibers, no host endothelialization and mild to moderate infiltration of inflammatory cells. Thrombus in the left atrium was detected in one case. Destruction of the cusps was seen in three cases and calcification of the cusps developed in three cases. In general, the Carpentier-Edwards porcine bioprosthesis provided good clinical improvement over the periods studied. However, morphological changes of the bioprosthetic valve, such as destruction collagen and elastic fiber, and inflammatory cell infiltration of the cusps, seems to occur more frequently with the passage of time. We therefore suggest that patients with this prosthesis should be followed carefully, particularly at late intervals after implantation.
To evaluate the myocardial protective effect of glucose-insulin (GI) in a cold cardioplegic solution, we compared the effect of a solution not containing GI (solution I) with that of an identical solution containing GI (solution II) under cardiopulmonary bypass in mongrel dogs. After 120 minutes of ischemic arrest, defibrillation was necessary to restore cardiac activity in 12.5% of the solution I group and 42.8% of the solution II group, respectively. No distinct intergroup differences were noted in recovery of left ventricular function, oxygen and lactate extraction of the myocardium during the post-arrest period, the myocardial ultrastructure, and myocardial ATP levels. Although creatine phosphate was less well preserved, glucose-6-phosphate and lactate were more accumulated in the solution II group than in the solution I group. Thus, significant advantages of substrate enhancement by addition of GI to cold cardioplegic solution were not found in spite of multidose cardioplegia and presence of noncoronary collateral blood flow.
BACKGROUND: We compared the severity of cardiac allograft vascular disease in rats treated with cyclosporine or FK506 and studied the effect of antithrombotic agents on cardiac allograft vascular disease. METHODS: One group each was treated with 2 and 5 mg/kg/day of cyclosporine. Two other groups were injected with heparin and dipyridamole, respectively, in addition to cyclosporine. Four other groups were similarly divided by dose of FK506 (0.1 or 0.25 mg/kg/day) and concomitant anticoagulant treatment. RESULTS: Grade of rejection and percentage stenosis of coronary arteries were lower in groups with high doses of immunosuppressive agents or with heparin. Major histocompatibility class II antigens were expressed by the endothelium of grafted hearts, and IgM and C3 were deposited in the intimal and medial layers in all groups except those administered the higher doses of immunosuppressive drugs. However, no remarkable differences in density of major histocompatibility class II antigens were found between groups demonstrating expression of these antigens. On the other hand, the intensity of IgM or C3 expression grew significantly as coronary stenosis increased in severity. CONCLUSIONS: A significant difference in severity of cardiac allograft vascular disease was not found between the groups treated with cyclosporine and FK506, and cardiac allograft vascular disease was almost entirely suppressed when doses of cyclosporine and FK506 sufficient to suppress graft rejection were administered. Our findings also showed that concomitant heparin administration reduced the extent of allograft rejection and the incidence of cardiac allograft vascular disease.