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Biomedical subjects

Y Toyoda

Publications and source records attributed to Y Toyoda.

At least 127 records · Page 7Linked to original sources
PubMed1997

Aggressive natural killer (NK) cell lymphoma: report of a pediatric case and review of the literature.

We report a rare pediatric case of aggressive natural killer (NK) cell lymphoma, characterized by acute onset hepatosplenomegaly and respiratory distress, and infiltration by large granular lymphocytes with the phenotype of CD3-CD16-CD56+. The patient has remained in complete remission after short-pulse intensive chemotherapy, and myeloablative therapy followed by allogeneic bone marrow transplantation. We compare our case with 7 other children with NK cell leukemia reported from other institutions.

Adolescent↗
PubMed1997

[Lesion-related factors associated with restenosis after percutaneous transluminal coronary angioplasty in the absence of patient-related factors].

Restenosis after percutaneous transluminal coronary angioplasty (PTCA) is one of the biggest problems in the treatment of coronary artery disease. Although many studies have been performed on lesion-related factors, they are influenced by patient-related factors such as smoking, hyperlipidemia, and the presence of acute coronary syndrome. In this study, lesion-related factors were assessed in the absence of other factors by univariate and multivariate analysis. One hundred and nine lesions were reviewed in 37 consecutive patients with both restenotic lesion(s) and non-restenotic one(s) confirmed by coronary arteriography performed 4.4 +/- 2.2 months after PTCA. Angiographic findings before and immediately after angioplasty were compared between restenotic and non-restenotic lesions. The overall lesion-restenosis rate was 42%. Univariate analysis revealed that calcified lesions (p < 0.05), multiple irregularities (p < 0.01) before angioplasty, residual percentage stenosis (p < 0.05), and angiographical intraluminal haziness (p < 0.05) were related to restenosis. Intimal dissection after PTCA was not associated with restenosis. Multivariate analysis with multiple logistic regression revealed that multiple irregularities (t = 2.8) was the most predictive of restenosis before PTCA and residual percent stenosis (t = 2.6) after the procedure. Coronary lesions with calcification or multiple irregularities indicate high risk of restenosis after PTCA. Optimal dilatation of the lesions without intraluminal haziness regardless of intimal dissection is important to prevent restenosis.

Aged↗
PubMed1997

[Present state of cord-blood stem cell transplantation].

Allogeneic bone marrow transplantation (BMT) can cure some hematologic and solid malignancies, but its success depends on the prompt identification of a suitable donor and the avoidance of severe graft-versus-host (GVH) disease. Transplantation using hematopoietic stem cells from umbilical cord blood may overcome these problems. Over the past several years, cord blood transplantation (CBST) from siblings and unrelated donors has been performed in more than 300 patients. The probability of event-free survival was almost similar to that for BMT. This review described the recent status of CBST in USA, Europe and Japan, and the outlook for CBST.

Child, Preschool↗
PubMed1997

Effect of an active metabolite of the antiallergic agent tazanolast on histamine release from rat mast cells.

WP-871 (3'-(1H-tetrazol-5-yl)oxanilic acid monohydrate, CAS 114607-46-4) is a monohydrate of a main active metabolite of tazanolast (butyl 3'-(1H-tetrazol-5-yl) oxanilate, CAS 82989-25-1), an orally active antiallergic drug. WP-871 inhibited dose-dependently compound 48/80-induced histamine release from rat peritoneal mast cells. In a similar dose range, WP-871 was effective in inhibiting compound 48/80-induced 45Ca uptake into mast cells from extracellular medium and compound 48/80-induced translocation of protein kinase C from the cytosol to the membrane fraction of mast cells. WP-871 also inhibited inositol trisphosphate production but did not exhibit a direct inhibitory effect on phospholipase C in mast cells. WP-871 caused no increase in cAMP content in mast cells. These results suggest that WP-871 may inhibit histamine release mainly by preventing the increase in intracellular Ca2+ concentration, which is a critical event in signal transduction leading to histamine release in mast cells.

Animals↗
PubMed1997

[Inoperable esophageal carcinoma managed by combined chemotherapy (CBDCA, 5-FU and VDS) and radiotherapy].

Eleven inoperable patients with advanced esophageal carcinoma were treated with chemotherapy (carboplatin, 5-FU, vindesine) and concomitant radiotherapy. Two patients (T2) received this treatment due to their poor general condition and refusal of operation, and 9 patients for infiltration of tumor into the adjacent organs (T4). Administration of carboplatin (30 mg/body) and 5-FU (250 mg/body) together with radiotherapy (1.8 Gy/d) for 5 days a week was performed. This chemoradiation therapy was carried out for 5 consecutive weeks. In addition, vindesine (1-3 mg/body) was administered in the 1st and 4th week. After evaluation, endoscopic balloon dilatation was performed in 6 patients with stenosis of the esophagus. The general response rate was 80%. CR was noted in 2 patients of T2 but 1 patient of T4 developed severe leucopenia and immunosuppression, and died of septic MOF. All but the MOF case could take enough food orally following the endoscopic dilatation. The 1-year survival rate in the T4 group (45%) was significantly better than the non-treatment group (0%). In conclusion, this treatment is beneficial for patients with inoperable esophageal carcinoma to obtain a satisfactory QOL and survival rate.

Aged↗
PubMed1997

[Cardiac operation for aged patients (aged 75 years and over): results of surgical intervention].

We evaluate the results of cardiac operation for 41 elderly patients (aged 75 years and over, mean, 77.5 years old). The overall hospital mortality was 12.2% (5/41) with mortality of 8.3% (2/24) in cases of elective operation and mortality of 17.6% (3/17) in cases of emergency operation. Causes of hospital death in emergency cases were congestive heart failure and left ventricular rupture (two cases) due to acute myocardial infarction. Patients who died in elective operation had been performed reoperation for bleeding and unstable sternum. These complications which need a reoperation seemed to be a potential risk for elderly patients. Because of poorer results of the emergency case, it is advocate to operate on these aged patients with an elective basis, if there is no absolute contraindications.

Age Factors↗
PubMed1997

Rupture of a dissecting aneurysm into the superior vena cava in Marfan's syndrome.

Aneurysmal dilatation of the aorta with subsequent dissection or rupture occurs frequently in patients with Marfan's syndrome. These complications are among the major causes of death. We report the case of a 51-year-old man with annulo-aortic ectasia in Marfan's syndrome. Acute aortic dissection and rupture into the superior vena cava occurred 8 years after aortic valve replacement. The preoperative diagnosis was made by right heart catheterization and computed tomography. A markedly increased left-to-right shunt occurred with rapid enlargement of the fistula due to the fragility of the aortic wall characteristic of Marfan's syndrome. Postmortem examination demonstrated severe medial necrosis with rupture of the aortic wall into the superior vena cava which was adherent to the suture line of the aortotomy from the previous surgery. Type A aortic dissection with severe congestive heart failure strongly suggested rupture into the pulmonary circulation.

Aortic Dissection↗
PubMed1997

Prevalence of equine piroplasmosis in Central Mongolia.

Antigen for the indirect fluorescent antibody test (IFAT) was routinely prepared from infected erythrocytes from horses experimentally infected with Babesia equi and Babesia caballi. With the successful establishment of in vitro cultures of B. equi and B. caballi, it is now possible to employ culture-derived antigens in this test. In this study, in vitro-propagated B. equi- and B. caballi-infected erythrocytes were used as antigen in the IFAT. Various modifications to an established protocol had to be implemented to allow repeatable results. Cultures with 3-4% parasitized erythrocytes were found to be most suitable. As cross-reactions of control sera on heterologous antigen were observed at serum dilutions of up to 1/40, a reciprocal titre of 80 was considered to be positive. In positive samples, specific fluorescence of Babesia parasites and/or erythrocyte membranes was observed. Fifteen sera from Babesia-free horses from Japan all tested negative in the IFAT. One hundred and ten field-horse sera from Central Mongolia were investigated in this study. The results indicate that both B. equi and B. caballi are endemic in horses in Central Mongolia, with 88.2% and 84.5% of horses being seropositive to B. equi and B. caballi, respectively.

Animals↗
PubMed1997

Unifocalization and systemic-to-pulmonary shunt using internal mammary artery for tetralogy of Fallot and pulmonary atresia with diminutive pulmonary artery and arborization anomaly.

We report successful palliation of tetralogy of Fallot and pulmonary atresia with diminutive pulmonary arteries and arborization anomaly. Unifocalization and systemic-to-pulmonary artery shunt using an internal mammary artery were successfully performed. The internal mammary artery shunt provided a sufficient blood supply for a diminutive and fragile pulmonary artery, and brought a progressive improvement of exercise intolerance and polycythemia probably due to the growth potential.

Cardiovascular Surgical Procedures↗
PubMed1996

Left-right asymmetric expression of the TGF beta-family member lefty in mouse embryos.

Examples of lateral asymmetry are often found in vertebrates, such as the heart being on the left side, but the molecular mechanism governing the establishment of this left-right (L-R) handedness is unknown. A diffusible morphogen may determine L-R polarity, but a likely molecule has not so far been identified. Here we report on the gene lefty, a member of the transforming growth factor-beta family, which may encode a morphogen for L-R determination. Lefty protein contains the cysteine-knot motif characteristic of this superfamily and is secreted as a processed form of relative molecular mass 25K-32K. Surprisingly, lefty is expressed in the left half of gastrulating mouse embryos. This asymmetric expression is very transient and occurs just before the first sign of lateral asymmetry appears. In the mouse mutants iv and inv, which cause situs inversus, the sites of lefty expression are inverted, indicating that lefty is downstream of iv and inv. These results suggest that lefty may be involved in setting up L-R asymmetry in the organ systems of mammals.

3T3 Cells↗
PubMed1996

Fusion of an ETS-family gene, EIAF, to EWS by t(17;22)(q12;q12) chromosome translocation in an undifferentiated sarcoma of infancy.

EIAF is a newly isolated ETS-family gene that is located on 17q21 and codes for the adenovirus EIA enhancer-binding protein. In our chromosome analysis of 18 of the Ewing family of tumors and undifferentiated sarcomas, we found t(17;22)(q12;q12) in an MIC2 antigen-positive undifferentiated sarcoma of infancy. On Southern blot analysis, EWS and EIAF cDNA probes hybridized to the same rearranged band, indicating that an EWS-EIAF fusion gene was formed in the tumor. Further Southern blot analysis using four EIAF cDNA probes of different sizes showed that the breakpoint lies in the region upstream to the ETS domain of the EIAF gene. EIAF may be the fourth ETS-family gene to be identified forming a fusion gene with EWS. We assume that the RNA binding domain of EWS may have been replaced by the DNA binding domain of EIAF in the EWS-EIAF fusion protein as in other fusion proteins previously characterized in Ewing sarcoma and other types of sarcomas.

Adenovirus E1A Proteins↗
PubMed1996

Staged repair of tetralogy of Fallot and pulmonary atresia without central pulmonary arteries.

A 15-year-old boy with tetralogy of Fallot and pulmonary atresia without central pulmonary arteries who was successfully treated using a staged approach is presented. The first stage consisted of the creation of central pulmonary arteries. In the second stage, the continuity between the right ventricle and the pulmonary arteries was established with closure of the ventricular septal defect. Some patients previously considered to be unsuitable candidates for correction may be successfully repaired using this approach.

Adolescent↗
PubMed1996

Successful engraftment of sibling cord-blood stem cell transplantation in a child with acute promyelocytic leukemia.

Cord blood stem cell transplantation (CBSCT) was performed on a patient with acute promyelocytic leukemia. The patient was a boy 3 years and 8 months old, who had shown complete remission following treatment with intensive chemotherapy. However, after the final course of consolidation chemotherapy, chromosome analysis of his bone marrow aspirates revealed 46XY, t(15,17)(q22;q21), and a PML-RAR alpha fusion gene was detected by the reverse transcriptase-polymerase chain reaction test. All-trans retinoic acid diminished the chromosomal abnormality, but the PML-RAR alpha fusion gene remained. The patient was then treated with CBSCT from an HLA-matched sibling donor. The number of nucleated cells in the cord blood was 2.2 x 10(7)/kg of body weight, and that of granulocyte-macrophage colony-forming units 0.6 x 10(4)/kg. Methotrexate was given, on days 3 and 6, as prophylaxis against graft-versus-host disease (GVHD). The neutrophil count rose to above 500/microliters on day 22. The platelet count exceeded 50,000/microliters on day 48. Platelet transfusions were given 12 times after CBSCT, the last one on day 36. Grade I acute GVHD was treated with steroids. The patient was well and discharged on day 103, without symptoms or laboratory data suggestive of relapse. Following this experience we instituted a project of the Kanagawa Cord Blood Bank, which is scheduled for expansion nationwide.

Adult↗
PubMed1996

A rare case of multiple atherosclerotic aneurysms involving the femoral artery.

Atherosclerotic aneurysm of the deep femoral artery is a rare peripheral aneurysm that is likely to have associated aortoiliac aneurysms. The case of a patient who had five atherosclerotic aneurysms located in the abdominal aorta, bilateral common iliac arteries, and the left common femoral and deep femoral arteries is reported. He underwent a semi-emergency operation for the aneurysm of the deep femoral artery, followed by a two-stage operation for the aortoiliac aneurysms. The aneurysm of the deep femoral artery was repaired, and reconstruction of the distal deep femoral artery successfully performed with direct anastomosis to the superficial artery. In this report, the clinical presentation of multiple atherosclerotic aneurysms and the details of surgical reconstruction are described.

Aged↗
PubMed1996

Transgenesis by adenovirus-mediated gene transfer into mouse zona-free eggs.

Zona-free mouse eggs at the pronucleus stage were infected with a replication-defective adenovirus vector containing a nuclear-targeted lacZ gene. Exogenous beta-galactosidase activity was detected in almost all eggs at the two-cell stage. Of 27 mice that developed from infected eggs, three carried the integrated exogenous gene mediated by the adenovirus. Two of the three expressed the lacZ gene, and all three mice transmitted the adenovirus-mediated transgene to F1 progeny Southern blot analysis was consistent with single copy integration. This finding should accelerate the development of new strategies for transgenesis and assist studies on the function of cloned genes in vivo.

Adenoviridae↗
PubMed1996

Growth of macroscopic human megakaryocyte colonies from cord blood in culture with recombinant human thrombopoietin (c-mpl ligand) and the effects of gestational age on frequency of colonies.

We investigated the effects of recombinant human thrombopoietin (rhTPO) on the growth of megakaryocytic (MK) colony derived MK progenitors from human cord blood (CB) in vitro and the effects of gestational age on the number of MK colonies. The results demonstrated that rhTPO alone supports the growth of MK colonies and induces not only proliferation but also differentiation of MK progenitors. CB shows a high frequency of MK colonies; most of which are very large and equivalent to high proliferative potential colony-forming unit-megakaryocyte. The colonies could be macroscopically observed as white spots in the culture dish. Preterm neonates showed greater numbers of MK progenitors than term neonates and there was an inverse correlation between gestational age and concentration of MK progenitors of CB. The effects of gestational age was an important factor on the proliferative capacity of MK progenitors and on the response to rhTPO.

Cell Culture Techniques↗
PubMed1996

Effect of hypotaurine on in vitro fertilization and production of term offspring from in vitro-fertilized ova of the Japanese field vole, Microtus montebelli.

The present study was proposed to establish new in vitro fertilization (IVF)-embryo transfer techniques for wild mammals. We demonstrated that IVF of the Japanese field vole, Microtus montebelli, is improved by hypotaurine, and that IVF vole embryos can develop to normal offspring after transfer to recipient females. The rate of IVF was significantly increased when 0.1 or 1 mM of hypotaurine was added during sperm preincubation and fertilization (p < 0.05). Preincubation of spermatozoa with 1 mM hypotaurine prior to oocyte insemination did not have a significant effect on fertilization rate (p < 0.01). At 96 h after insemination, most cultured embryos developed to the 2-cell stage (68-83%), but development to blastocysts was very low (0-3%) for all treatments. Although 43 living offspring were produced after transfer of IVF pronuclear embryos to recipients, the delivery rate of recipients was very low (21%). The litter size of pseudopregnant recipients that produced a litter was 4-11, and the rate of in vivo development of transferred embryos in the pregnant recipients was 41%. These results suggest that hypotaurine affects IVF rather than sperm preincubation and that IVF embryos can develop to normal offspring.

Animals↗