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Biomedical subjects

M Okada

Publications and source records attributed to M Okada.

At least 1,261 records · Page 70Linked to original sources
PubMed1989

[The influence of left ventricular function on surgical risk in mitral stenosis].

The influence of left ventricular (LV) function on surgical risk was assessed in 98 patients with mitral stenosis (MS) using echocardiographic studies including a dobutamine test in 42 cases. Intraoperative LV myocardial biopsy was also performed in 24 cases. Preoperatively, depressed LV function [% fractional shortening (%FS) less than or equal to 27%] was observed in 21 patients (21%). Seven patients had postoperative LV failure, five of whom had preoperative depression of LV function. Among these five patients, three had low cardiac output; and in the other two preoperative %FS was severely depressed. In cases of poor responses to preoperative dobutamine, postoperative improvement in %FS and the cardiac index were not as marked in the good-response group, and some of these patients had LV failure postoperatively. Percent fibrosis of the LV myocardium, which was demonstrated by intraoperative biopsy, correlated negatively with preoperative %FS, and %fibrosis was greater in the group responding poorly to dobutamine administration, especially in patients with postoperative LV failure. These results suggest that some patients with MS were developing LV failure postoperatively due to impaired myocardium. Myocardial fibrosis seemed to be an important causative factor in these patients. Preoperative evaluation utilizing dobutamine administration is useful in screening for high-risk patients.

Adult↗
PubMed1989

[Aneurysm of non fistulous ductus arteriosus in the adult: a case report].

A 64-year-old woman was admitted because of abnormal shadow in the chest X-ray film. A cystic aneurysm at the proximal portion of the descending aorta was clearly confirmed by CT and aortography. At the time of operation, an aneurysm of ductus arteriosus, of which lumen was filled by thrombus was recognized. The aneurysm was successfully resected and defect of the aortic wall was covered with Dacron patch. Postoperative course was uneventful. This is so rare disease that this patient is the second operated case in Japan.

Aneurysm↗
PubMed1989

Growth and differentiation of a human megakaryoblastic cell line, CMK.

Recently, a human megakaryoblastic cell line, CMK, was established from the peripheral blood of a megakaryoblastic leukemia patient with Down syndrome. Using this cell line, we studied the proliferation and differentiation of megakaryocytic cells in the presence of highly purified human hematopoietic factors and phorbol 12-myristate-13-acetate (PMA). In a methylcellulose culture system, interleukin-3 (IL-3) and granulocyte-macrophage colony-stimulating factor (GM-CSF) facilitated colony formation by CMK cells in a dose-dependent manner. The maximum stimulating doses of these factors were 10 and 200 U/mL, respectively. These concentrations were comparable to those that stimulate activity in normal hematopoietic cells. In contrast, granulocyte-colony stimulating factor (G-CSF), macrophage-colony stimulating factor (M-CSF), and erythropoietin (EPO) had no effects on the colony formation of CMK cells. In a liquid culture system, 20% of the CMK cells expressed glycoprotein IIb/IIIa (GPIIb/IIIa) antigen without hematopoietic factors, whereas 40% of the cells expressed GPIIb/IIIa with the addition of IL-3 and GM-CSF. EPO also slightly enhanced expression of GPIIb/IIIa. On the other hand, PMA inhibited growth of CMK cells and induced most of them to express the GPIIb/IIIa antigen. Furthermore, PMA induced CMK cells to produce growth activity toward new inocula of CMK cells. This growth factor (GF) contained colony-stimulating activity (CSA) in normal bone marrow (BM) cells. The activity was believed to be attributable mainly to GM-CSF, since 64% of this activity was neutralized by anti-GM-CSF antibodies and a transcript of GM-CSF was detected in mRNA from PMA-treated CMK cells by Northern blot analysis. These observations suggest that GM-CSF, as well as IL-3, should play an important role in megakaryocytopoiesis.

Blotting, Northern↗
PubMed1989

[A case of right atrial myxoma with successful removal].

The incidence of primary cardiac tumors is very rare. However, the number of reported cases has recently increased due to the widespread use of echocardiography. This patient was a 67-year-old male whose main complaint was dizziness on standing. Right atrial myxoma was diagnosed by two-dimensional echocardiogram. Because of persistent right heart failure, open heart surgery was performed as a sub-emergency procedure. The myxoma was removed successfully and its weight was 93 g. The site of origin of the tumor was the lateral wall of the right atrium close to the entrance of the inferior vena cava.

Aged↗
PubMed1989

Factors influencing the healing rate of gastric ulcer under treatment with cimetidine.

Factors influencing the healing rate were evaluated by multivariate analysis on 148 patients with gastric ulcer who were under treatment with cimetidine at a daily dose of 800 mg. Factors used were age, sex, therapeutic environment, duration of present ulcer pain, past history of gastric ulcer, the amount of tobacco, alcohol, and coffee consumed before and during the treatment, the period until symptoms disappeared after the commencement of the treatment, and the characteristics of the ulcers themselves. Of these factors, the five factors that had a significant delaying effect on the healing of gastric ulcers were: 1) having a past history of gastric ulcers, 2) symptoms not disappearing within 1 wk after the commencement of the treatment, 3) size over 20 mm, 4) ulcer located in an angle, and 5) round or oval shape of the ulcer. The patients with less than one of the unfavorable factors (n = 36) had the best healing rate (97.2%), compared with those with two (n = 61), three (n = 39), or four or more (n = 12) unfavorable factors. The healing rate of the latter three groups was 75.4%, 53.8%, and 33.3%, respectively (p less than 0.01). Thus, a prognostic score based on these five factors represents the severity of gastric ulcers with regard to the healing in patients prescribed cimetidine.

Cimetidine↗
PubMed1989

[Surgical treatment of superior vena cava syndrome (SVC)].

SVC syndrome is occurred by the occlusion or stenosis of the superior vena cava secondary to malignant mediastinal tumor. Up to this report, surgical intervention has been thought to be difficult. Recently, extent of the tumor has been diagnosed exactly by CT scan, NMR, and angiography. Several cases undergoing complete resection of the tumor with the technique of vascular surgery have been reported. During the past 10 years, we have experienced 21 cases of SVC syndrome. 16 patients had operations and 5 patients had radiation or chemotherapy. The methods of operations were as follows: complete resection of the tumor 1, complete resection of the tumor and reconstruction of SVC 2, subtotal resection of the tumor and reconstruction of SVC 2, bypass of SVC only 5, extra-anatomical bypass 3. PTFE grafts were placed between right subclavian vein and SVC or left subclavian vein and right atrium. Extra-anatomical bypass were placed between jugular vein and femoral vein. PTFE bypass graft provides effective treatment for SVC obstruction with immediate and long term relief of SVC syndrome.

Aged↗
PubMed1989

[Surgical treatment of stage III and IV thymoma].

During past 15 years, 39 cases of thymoma were underwent surgical intervention. In these cases, invasive type, so called stage III and IV in Masaoka's classification were 19 cases. This report documents the results of extended operation in 19 patients treated for malignant thymoma. All patients had neoplasm which invaded adjacent structures; superior vena cava, pericardium, and lung. Eight patients had disseminated lesions in the pleural or pericardial cavities. All patients were underwent surgical exploration through median sternotomy (18 patients) or left thoracotomy (1 patient). Our surgical management to malignant thymoma is to have complete resection, even if tumor invades the great veins. Of 8 patients, superior vena cava and left innominate vein were resected with tumor and reconstructed with ringed PTFE. Mediastinal pleura and pericardium should be widely opened and intrapericardial or intrapleural disseminated lesions should be removed as far as possible. Malignant thymoma could be resected completely applying technique of vascular surgery. Good results were expected when tumor was resected with invading adjacent structures completely. Reoperation to the recurrent tumor is also important.

Humans↗
PubMed1989

[Surgical treatment of acute aortic dissection].

Sixty-seven patients subjected to this study composed of 32 patients treated surgically, 15 patients treated medically and 20 patients examined by autopsy for the past 8 years. Out of 32 surgical cases, 16 were operated on in an acute stage, within 2 weeks after onset and 9 out of these 16 acute cases belonged to DeBakey type I or II and 11 out of 15 autopsy cases belonged to type I or II either. Contrarily most of the medical cases were type III. Both causes of death in the acute autopsy group and operative indications in the acute surgical group were cardiac tamponade, heart failure due to aortic insufficiency, myocardial infarction and aortic rupture. Operative mortality rate was 12.5% in the acute cases and 19% in the chronic cases, late mortality rate was 19% in the acute cases and 0% in the chronic cases. Two cases of operative death had massive bleeding due to aortic rupture and massive myocardial infarction. These were the most dangerous complications of acute aortic dissections. We conclude that all patients with type I or II dissections should be operated on before fatal complications occur.

Acute Disease↗
PubMed1989

[Soluble interleukin-2 receptor levels in patients with pulmonary tuberculosis].

Utilizing an enzyme-linked immunosorbent assay, we detected markedly elevated serum levels of soluble interleukin-2 (IL-2) receptors in patients with untreated pulmonary tuberculosis. In these patients, we also found that serum levels of soluble IL-2 receptors were closely correlated with serum adenosine deaminase levels (r = 0.869, p less than 0.001). Therefore, serum soluble IL-2 receptors appear to reflect the existence of active cell-mediated immunity in pulmonary tuberculosis and may prove to be a useful immunological marker for pulmonary tuberculosis.

Adult↗
PubMed1989

[Closure of patent ductus arteriosus in elderly cases].

A technique for closure of patent ductus arteriosus in the elderly cases is described. We have operated on eleven adult cases of patent ductus arteriosus cases in 10 years. In five cases cardiopulmonary bypass used and in the other six cases it was not used. The cardiopulmonary bypass was used especially for the patients with pulmonary hypertension (pulmonary artery mean pressure greater than 40 mmHg), or high aged (older than 40 years) patients. No operative death have occurred in both groups, and no complication from air embolism or hemorrhage have been encountered. The technique embodies the profound hypothermia, low flow, and direct suture of the pulmonary end of the ductus arterious through a pulmonary arteriotomy. The ductus has been obstructed by using a Hegar's dilator before core cooling was started. Hegar's dilator is useful for establishing profound hypothermia and satisfactory visualization of the operative field.

Adult↗
PubMed1989

[HLA study in 108 Japanese patients with Crohn's disease].

We attempted to clarify the association between HLA and Crohn's disease. HLA-A, -B, -C, -DR and -DQ locus antigens in 108 Japanese patients with Crohn's disease were analyzed and the results were compared with findings of 472 healthy Japanese. In patients with Crohn's disease there was a strong positive association with HLA-DR4 (chi 2 = 14.086, Pc less than 0.005, RR = 2.231), and a weak positive association with HLA-B51, -Bw54, -DRw12, -DRw13 and -DRw52. While there was a strong negative association with HLA-DR2 (chi 2 = 10.194, Pc less than 0.025, RR = 0.435), DQw1 (chi 2 = 14.680, Pc less than 0.001 RR = 0.442) and DQw3 (chi 2 = 7.760 Pc less than 0.025 RR = 0.549), and a weak negative association with HLA-B7. In conclusion, susceptibility to Crohn's disease may relate to HLA-DR4, especially HLA-DR4.1, in Japanese patients.

Adolescent↗