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Biomedical subjects

O Yamada

Publications and source records attributed to O Yamada.

At least 145 records · Page 8Linked to original sources
PubMed1992

[Cardiac performance in total anomalous pulmonary venous connection].

Cardiac performance in 54 patients with total anomalous pulmonary venous connection was investigated by cardiac catheterization before and after surgery. 51 patients underwent intracardiac repair, and 17 of them died during or immediately after operation. According to the preoperative study, the left ventricular ejection fraction (LVEF) of surviving patients was significantly higher than that of patients who died, and the pulmonary arterial mean pressure of surviving patients was significantly lower than that of patients who died. However, there was no significant difference between the left ventricular end-diastolic volume (LVEDV), right ventricular ejection fraction (RVEF), and right ventricular end-diastolic volume (RVEDV) in surviving patients and those who died. Post-operative catheterization studies showed significant increases of LVEF and LVEDV compared to pre-operative figures. RVEF and RVEDV and pulmonary arterial mean pressure decreased significantly after surgery. It was concluded that preoperative cardiac performance of surviving patients was better than that of those who died, and post-operative cardiac performance of surviving patients was basically normal.

Blood Pressure↗
PubMed1992

[Concomitant graft replacement of the total aortic root and the transverse aortic arch for type A aortic dissection associated with annuloaortic ectasia].

Between April 1988 and February 1992, eight patients with type A aortic dissection associated with annuloaortic ectasia (AAE) underwent the concomitant graft replacement of the total aortic root and the transverse aortic arch at our institution. The acuity of the aortic dissection was acute stage in 3 patients and chronic stage in 5 including 3 cases of re-do operation. All operations were performed with an aid of extracorporeal circulation, blood cardioplegia, selective cerebral perfusion and open distal anastomosis. The operative techniques employed in this series consisted of total aortic root replacement using a composite graft (Bentall, Cabrol or Piehler's technique), and total arch replacement using en bloc arch reconstruction or three vessels graft replacement. One patients underwent re-do operation for coronary anastomotic false aneurysm following Bentall operation and aneurysmal dilatation of the false lumen at the aortic arch, and died of LOS because of the prolonged myocardial ischemia. Other seven patients survived the operation, and lead the normal life at the present time. The present data suggests that type A aortic dissection associated with AAE involving aortic arch could be treated by concomitant graft replacement of the total aortic root and the transverse aortic arch.

Adult↗
PubMed1992

[Surgical treatment of Marfan's syndrome with annulo aortic ectasia and mitral regurgitation].

This report is concerned with results of surgical treatment for Marfan's syndrome combined with annulo-aortic ectasia (AAE) and mitral regurgitation (MR). Of the 23 patients with Marfan's syndrome who received Bentall's procedure during 14 year period, seven (30%) of these patients had both AAE and MR. The MR grade of seven patients by cardiac Doppler or left ventriculographic studies were grade 1 in 2, 2 in 1, 3 in 1, and 4 in 3. Atrial fibrillation was present in 4 patients. New York Heart Association Functional Class on admission in these 7 patients were II in 1, III in 4, and IV in 2. The mitral valve was replaced with mechanical valve in 4 patients by left atrial approach whose MR grade were over 3. In the 4 patients the mitral annuli were extremely dilated, both valve leaflets were massively redundant, and all chordae were elongated and turned chordae and vegetation were detected due to infective endocarditis. Only Bentall's procedure was performed in 3 patients whose MR were minimal. There were no early death, but two late deaths. One of them died of cardiac failure 2.3 years after Bentall's procedure because grade 2 MR was increased. Another one died from ventricular arrhythmia 1.6 years after MVR and Bentall's procedure. The remaining 5 patients are doing well for 3 months to 11.5 years after operation. For Marfan's syndrome combined with AAE and MR, early operation is recommended before left ventricular impairment. Mitral valve repair was not performed, both to save time and because anticoagulant therapy was need for aortic valve replacement. Concomitant MVR was to be done for moderate to severe MR.

Adult↗
PubMed1992

[Abnormalities of beta spectrin with hereditary elliptocytosis in mother and child].

It is generally considered that abnormality of the erythrocyte membrane skeleton co elliptocytes. There are, however, few reports of beta spectrin variants. We found a new variant of beta spectrin in a child and her mother. This report is the first case of abnormality of beta spectrin in Japan. The propositus was an 8 month-old girl who was first examined by us in 1988. On laboratory findings, she showed anemia, increased reticulocyte count and decreased haptoglobin concentration. Both peripheral blood smears of patient and her mother showed typical elliptocytosis and they were diagnosed as hereditary elliptocytosis. SDS-PAGE patterns of the red cell membranes of the propositus and her mother were characterized by the presence of an abnormal component migrating immediately below the spectrin chains. We confirmed that the abnormal spectrin appeared clearly at the expense of normal beta chain. The abnormal spectrin (M.W. 216,000d) makes up 16% of the total beta chain. The inheritance of our case was autosomal dominant. The present case is considered as a new spectrin variant.

Adult↗
PubMed1991

Physiologic and anatomic assessment of patients with rectocele.

Clinical, physiologic, and anatomic assessments were carried out in 22 female patients with symptomatic rectocele (Group A), 15 patients with asymptomatic rectocele (Group B), and 14 subjects having no rectocele (Group C). Resting and pressure, rectal pressure, rectal compliance, anorectal inhibitory reflex, and rectal sensation did not differ among the groups. Proctography revealed that the lengths of the rectocele during attempted defecation in groups A (1.6 [1.0-3.5] cm) (median and range) and B (1.6 [1.0-3.0] cm) were significantly greater than that in Group C (0.4 [0.1-0.9] cm) (P less than 0.001 in both groups). Median pelvic floor descent at rest in Groups A (4.3 [1.6-7.5] cm) (median and range) and B (4.3 [1.3-6.9] cm) were significantly greater than that in Group C (2.5 [1.2-5.0] cm) (P less than 0.001 and P less than 0.02, respectively). These results indicate that rectocele is not associated with any physiologic change apart from a significant increase of pelvic floor descent.

Adult↗
PubMed1991

Aortic valve replacement with omniscience and omnicarbon valves.

Clinical results achieved in 100 cases of aortic valve replacement with the Omniscience (O-S) valve during the period from 1980 to 1985 as well as 100 cases of aortic valve replacement with the Omnicarbon (O-C) valve during the period from 1985 to 1989 were studied. Concomitant surgical procedures including mitral valve replacement were performed in 63 patients in the O-S group and 67 patients in the O-C group. Cumulative follow-up in the two groups was carried out for a total of 559 and 273 patient-years, respectively. The overall 4-year actuarial survival rate was 82% +/- 3.8% in the O-S group and 89.5% +/- 3.2% in the O-C group, the corresponding rates for patients undergoing isolated aortic valve replacement being 82.9% +/- 4.2% in the O-S group and 91.9% +/- 3.5% in the O-C group. The overall 4-year actuarial event-free rate with respect to thromboembolic complications was 88.8% +/- 3.3% in the O-S group and 94.4% +/- 2.8% in the O-C group, as compared with the corresponding rates of 89.2% +/- 3.6% in the O-S group and 95.9% +/- 2.8% in the O-C group for patients undergoing isolated aortic valve replacement. The overall rate of valve-related complications, including thromboembolism, anticoagulant-related hemorrhage, perivalvular leak, infection, and structural failure, was 78.8% +/- 4.2% in the O-S group and 89.3% +/- 3.5% in the O-C group (p less than 0.05), and for isolated aortic valve replacement, 79.7% +/- 4.5% in the O-S group and 89.6% +/- 4.1% in the O-C group.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1991

Contrasuppressor T cell leukaemia: clonal proliferation of contrasuppressor T cells in a patient with granular lymphocyte-proliferative disorder.

In 12 patients with granular lymphocyte-proliferative disorders (GLPD), we studied the capacity of patient peripheral blood mononuclear cells (PBMC) to promote or suppress polyclonal IgG synthesis by normal non-T cells in pokeweed mitogen-containing medium using an enzyme-linked immunosorbent assay. During the experiments we found a patient whose PBMC possessed contrasuppressor function. The patient was a 27-year-old female with anaemia and lymphocytosis of CD3+CD8+ granular lymphocytes (GL). Reconstitution experiments using normal donor non-T cells and CD4+ and CD8+ T cells showed that addition of the patient's CD8+ cells abrogated the suppressor cell function of normal CD8+ T cells. The patient's PBMCs were CD3+, CD8+, Ia+, and Vicia villosa lectin-adherent characteristics which are consistent with those of normal blood contrasuppressor T cells. The T cell receptor beta and gamma genes were found to be monoclonally rearranged. Ultrastructurally, this patient's GLs exhibited clusters of dense cytoplasmic bodies, which were not detected in the GL of other patients with GLPDs. These results indicate that the clonal proliferation of contrasuppressor T lymphocytes had occurred in this patient.

Adult↗
PubMed1991

[Comparative analysis of Hancock and St. Jude Medical valve after mitral valve replacement].

Long term results were compared in 81 operative survivors with MVR using Hancock valve (Hancock group) and 83 using St. Jude Medical valve (SJM group). The cumulative follow-up was 709.0 patients-year (p-y) and 175.2 p-y in the Hancock and SJM groups. Twenty-four percent of the patients in the Hancock group was permanently anticoagulated, while 100% of patients in the SJM group anticoagulated. The 7-year actuarial survival rate including early mortality was 79.3 +/- 4.6% for the Hancock and 93.9 +/- 3.0% for the SJM group (p less than 0.01). The survival rate was significantly higher in the SJM group than that in the Hancock group. The 7-year actuarial event free rate of the valve-related complications in the Hancock and SJM groups were as follows; thromboembolism 88.6 +/- 3.8% vs 95.0 +/- 2.8% (NS), hemorrhage, 94.0 +/- 3.0% vs 98.7 +/- 1.8% (NS), paravalvular leak 92.6 +/- 3.2% vs 97.4 +/- 1.8% (NS), infection 93.9 +/- 3.0% vs 100% (p less than 0.05), valve malfunction 78.0 +/- 5.2% vs 100% (p less than 0.001), overall valve related complications 58.9 +/- 5.9% vs 91.1 +/- 3.5% (p less than 0.001), reoperation for valve-related complication 83.1 +/- 4.6% vs 100% (p less than 0.01). The event free rate of reoperation for valve related complication in the Hancock group was significantly lower than that in the SJM group. The Hancock valve had the acceptable antithrombogenicity, but had the limited long-term durability.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1991

[Reoperation of primary tissue failure of bioprosthesis in the mitral position].

The surgical results of 38 patients who underwent reoperation for primary tissue failure of bioprosthesis in the mitral position between May 1982 and June 1990 were analyzed to determine the risk factors affecting the hospital mortality. The type of bioprostheses requiring reoperation were Hancock valve in 21 patients, Liotta valve in 15 patients and Mitroflow valve in 2 patients. Twenty-five preoperative and perioperative variables were collected and analyzed by univariate statistics using chi 2 test or Student's test. Four of thirty eight patients died postoperatively in the hospital, yielding an overall mortality of 10.5%. The causes of hospital mortality were low output syndrome in 2 patients and multiple organ failure in 2 patients. By univariate analysis, male, NYHA IV class, prosthetic stenosis, hepatic failure, renal failure, and pulmonary failure were risk factors predictive of high hospital mortality. In spite of recent improvement of surgical technique and myocardial protection, the hospital mortality of patients with NYHA IV class and advanced organ failure still remains unacceptable. Therefore, it is essential to perform reoperation for primary tissue failure of bioprosthesis before severe myocardial decompensation occurs. To accomplish this goal, patients with bioprosthesis who survived beyond the certain time should be followed periodically using echocardiogram.

Adult↗
PubMed1991

[Surgical repair of descending aortic aneurysms--experience in 100 patients under partial cardiopulmonary bypass].

Between 1975 and 1986, 100 consecutive patients with aneurysms of the descending thoracic (84 cases) or the thoracoabdominal aorta (16 cases) underwent surgical repair. Intraluminal graft inclusion procedure was employed in principle under routine circulatory support with partial cardiopulmonary bypass. In this study, overall surgical results were reviewed, and multiple factors discriminately contributing to early results were assessed using multivariate analysis (quantification theory type II) to determine if this therapeutic modality is pertinent. Fifty-five patients had non-dissecting, 42 had dissecting aneurysms and 3 had pseudoaneurysms. Seventeen patients were treated in the emergency setting. Perioperative or early deaths occurred in 14 patients. Mortality increased with advanced age (greater than 70 years) and with atherosclerotic aneurysms, especially when they involved the entire thoracic or thoracoabdominal aorta. Operative mortality during the last 5 years of the study was 9.3%: significantly lower than the figure in the first 5 years of 28% (p = 0.0198). The incidence of renal dysfunction (7.4%) or paraplegia (2.1%) was not related to aortic cross-clamp time, and both were markedly decreased to 3.8% and 0.0%, respectively, when the cases of thoracoabdominal aneurysms were excluded. There were 8 cases of exploration for postoperative hemorrhage and 6 cases of pulmonary insufficiency requiring more than 3 days of mechanical ventilation. Prolonged bypass time was a discriminative risk factor for these two complications. Cerebral vascular accidents developed in 5 patients, three of them terminated in death. In spite of partial bypass, the factors of advanced age, atherosclerosis, and cross-clamp on the aortic arch were defined responsible for brain stroke.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

[Surgical treatment for aneurysms of the ascending aorta with aortic regurgitation: early and late results of simultaneous replacement of the aortic valve and the ascending aorta].

From September 1976 to January 1991, 66 patients were operated on for aneurysms of the ascending aorta with aortic regurgitation. The indication for operation was annuloaortic ectasia in 40 patients (61%) and aortic dissection in 26 (39%). Twenty-seven patients (41%) had the classical Marfan syndrome. The surgical techniques employed in this series included separate graft valve replacement (separate G/V) in 18 patients whose coronary ostia were normally placed, and composite graft replacement with coronary reimplantation (composite G) in 48 patients whose coronary ostia were displaced cephalad by the aneurysm. Nineteen patients (29%) had the concomitant operative procedures including aortic arch replacement and mitral valve repair. The early death within one month after the operation occurred in 6 patients (9.1%) comprising 2 (7.1%) in the separate G/V group and 4 (8.3%) in the composite G group. The 10-year survival rate including early death was 77% for the whole series, 70% for the separate G/V group and 79% for the composite G group. There was no significant difference in long term survival rate between the separate G/V and composite G groups. No patients required reoperation for the ascending aorta and the aortic valve in the both groups. However, six patients required subsequent operation for aneurysmal disease or dissection of the remaining thoracic and abdominal aorta. The 10-year event free rate of reoperation was 82% for the whole series, 93% for the separate G/V group and 79% for the composite G group. There was no significant difference in the reoperation event free rate between the separate G/V and composite G groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1991

[Hypoplastic leukemia successfully treated with low-dose aclarubicin: a case report].

Low-dose aclarubicin (LDACR) therapy is one of the differentiation induction therapy, such as low-dose cytosine arabinoside therapy, 1 alpha, 25 dihydroxy-vitamin D3 or retinoic acid therapy, for myelodysplastic syndrome and atypical leukemias. A 36-year-old female with hypoplastic acute myelogenous leukemia was treated with this atypical leukemias. A 36-year-old female with hypoplastic acute myelogenous leukemia was treated with this LDACR therapy. On admission, she was suffered from general fatigue and her peripheral blood smear showed pancytopenia with 23% of myeloblasts. Bone marrow examination revealed a moderately hypoplastic marrow with 35.4% of myeloblasts. She was diagnosed as having hypoplastic acute myelogenous leukemia. Thereafter, 20 mg of aclarubicin was given daily by one-shot intravenous injection for 10 days. After this LDACR therapy, myeloblasts disappeared from her peripheral blood and pancytopenia improved. Bone marrow examination showed increase in nuclear cell counts and she achieved complete remission. In this article, we report the clinical course of this patient and discuss the effect of LDACR therapy as useful chemotherapy for this patient.

Aclarubicin↗
PubMed1991

[Surgical repair for aortic aneurysms in aged patients over 70 years of age].

From 1960 through 1991, 556 consecutive patients with aortic aneurysms consisting of 173 with abdominal aortic aneurysms (AAA) and 383 with thoracic aortic aneurysms (TAA) were treated surgically. No significant differences were observed in the early mortality rate after AAA or TAA repair between the aged (41 TAA, 52 AAA) and non-aged groups. The 5-year survival rate of aged patients with TAA (47.3 +/- 8.5%) was significantly lower to that of non-aged patients (67.4 +/- 2.8%). However, the 5-year survival rate of aged patients with AAA (63.9 +/- 12.1%) was not significantly different from that of non-aged patients (75.9 +/- 4.3%). The asymptomatic non-ruptured aneurysms in aged-patients present many problems such as the association between surgical intervention and life expectancy, selection of patients by accurate preoperative evaluation of risk factors, and determination of the timing of operation.

Age Factors↗
PubMed1990

Cytotoxic T lymphocyte triggering via CD16 is regulated by CD3 and CD8 antigens. Studies with T cell receptor (TCR)-alpha beta+/CD3+16+ and TCR-gamma delta+/CD3+16+ granular lymphocytes.

The role of CD3 and CD8 Ag in CD16-mediated CTL triggering was studied in TCR-alpha beta+ and TCR-gamma delta+ granular lymphocytes (GL). In TCR-alpha beta+/CD3+4-8+16+ GL obtained from patients with GL-proliferative disorders, antibody-dependent cellular cytotoxicity was inhibited by anti-CD3 and anti-CD8 mAb. Anti-CD3 mAb also inhibited antibody-dependent cellular cytotoxicity activity of TCR-gamma delta+/CD3+4-8-16+ GL from a patient and that of TCR-gamma delta+/CD3+4-8+/-16+ T cell clones established from patients with proliferating TCR-gamma delta+ GL. In TCR-gamma delta+ T cell clones, cytotoxicity against Fc gamma R+ targets was induced by stimulation of CD16 Ag with anti-CD16 mAb, and such cytotoxicity was also inhibited by anti-CD3 mAb. These results indicate that CD3 and CD8 molecules play a regulatory role in CD16-mediated CTL triggering.

Antibody-Dependent Cell Cytotoxicity↗
PubMed1990

A new method for extracting DNA or RNA for polymerase chain reaction.

The use of glass powder suspension for the extraction of RNA or DNA was studied to simplify the procedures of polymerase chain reaction (PCR). Using this procedure, proviral DNA of human T-lymphotropic virus type-1 (HTLV-1) in the blood of an asymptomatic virus carrier and viral RNA of human immunodeficiency virus (HIV) in the blood of an AIDS patient were easily detected by PCR employing glass powder. The use of glass powder is a simple and highly efficient procedure for the extraction of DNA or RNA, and can be applied for routine PCR.

Acquired Immunodeficiency Syndrome↗