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Biomedical subjects

K Oda

Publications and source records attributed to K Oda.

At least 325 records · Page 18Linked to original sources
PubMed1994

[Surgical treatment of subaortic stenosis].

We reviewed 10 cases with subaortic stenosis (SAS) who underwent surgical repairs in our hospital. They were divided into 3 groups. Group I-A included patients with discrete SAS which had been detected before the initial operation. Group I-B included patients with discrete SAS which became apparent following the initial operations. Group II patients included SAS except the discrete type. Surgical treatment of each group was discussed. In group IA, there were no early deaths nor late deaths. There was 1 reoperation due to restenosis. Group IB had 3 cases which included VSD with CoA, Taussig-Bing anomaly, and common atrioventricular canal with VSD. In the Taussig-Bing anomaly case, an arterial switch (Lecompte maneuver) was performed 3 years ago. SAS was successfully relieved with the right ventriculotomy and VSD patch incision. Group II had 3 cases. There were 2 operative deaths and 1 late death. SAS was relieved by, in two cases, Stansel anastomosis with BT shunt and, in the last one, palliative arterial switch operation. It was extremely difficult to detect SAS in group II, when SAS had rapidly progressed following PAB in neonate and early infant. Our present policy is that PAB would be performed if there is no apparent SAS before the initial operation. SAS should be relieved as soon as possible if it is apparent at the postoperative period. Either Stansel anastomosis with BT shunt or palliative arterial switch operation would be the best choice in such a difficult case.

Aortic Valve Stenosis↗
PubMed1994

[Transcatheter embolization of aorto-pulmonary collateral arteries in cyanotic congenital heart disease].

Transcatheter embolization (TE) using steel coils was performed on three patients with aorto-pulmonary collateral arteries (APCAs). Case #1: In a 13-year-old boy who had undergone corrective surgery for pulmonary atresia with ventricular septal defect (PA with VSD), one APCA was embolized by the TE technique. This resulted in a remarkable improvement in postoperative pulmonary congestion. Case #2: A 13-year-old boy who had previously undergone procedures to correct tetralogy of Fallot (TOF), underwent TE for two APCAs prior to subsequent surgery before for pulmonary stenosis. The procedure abandoned one APCA because of the long narrow origin of the vessel. For the other APCA, TE was unsuccessfully performed due to the displacement of a coil into the peripheral pulmonary artery. Case #3: An 8-year-old girl with PA with VSD underwent TE for three APCAs before corrective surgery. One APCA arising from the abdominal aorta was occluded successfully. The other two were considered too small at the orifice for TE, and were ligated surgically before corrective surgery. TE is a safe and effective method for suitable cases of APCAs. However, caution should be exercised to prevent complications. The selection of appropriate coils and catheters is also important.

Adolescent↗
PubMed1994

[Attenuation correction using postinjection transmission measurements for PET: the optimization of measurement conditions].

A new method of PET attenuation using post-injection transmission scan is presented, which is especially useful in 18F-FDG static studies. The transmission scan is acquired right before the emission scan, which is used to subtract the emission component from the transmission data. When the effect of measurement condition upon the image noise was evaluated with a 20 cm diameter cylindrical phantom, an increase in the injection dose inflated the noise and caused artifacts. There was an optimum dose that minimized the image noise. As the external source activity increased, the image noise decreased, and the optimum dose increased linearly, which enabled estimation of the optimum injection dose under a given external source. When the total (emission plus transmission) scan time was fixed, longer emission scan resulted in better images than longer transmission scan.

Gallium Radioisotopes↗
PubMed1994

Isolation of Japanese encephalitis virus from Culex sitiens mosquitoes in Selangor, Malaysia.

Isolation of Japanese encephalitis virus (JEV) from mosquitoes in Sabak Bernam, Selangor, Malaysia, was attempted. An aliquot of homogenate from each pool of mosquitoes, 50 per tube, was inoculated into Aedes albopictus clone C6/36 cells for virus isolation. Each cell culture was tested for the presence of viral antigen by immunoperoxidase staining using an anti-JEV polyclonal antibody. Out of 4 Culex sitiens mosquito pools, 2 pools were positive for JEV by cell culture. Presence of JEV genome in the cell cultures for Cx. sitiens was confirmed by using reverse transcriptase-polymerase chain reaction and JEV-specific primers. This is the first report on the isolation of JEV from Cx. sitiens.

Aedes↗
PubMed1994

[Right-sided infective endocarditis with ventricular septal defect].

Two patients underwent surgical treatment for right-sided infective endocarditis with ventricular septal defect. In both cases, blood cultures showed Peptostreptococcus, and the operation was performed at non-active phase after antibiotics therapy. The case 1 was a 7-year-old girl who was observed a vegetation on the chorda of the anterior paillary muscle by echocardiography. The defect was directly closed and the vegetation was excised. The case 2 was 22-year-old female who had been diagnosed of VSD in her infancy. A high fever continued and echocardiography revealed a vegetation attached to the septal tricuspid leaflet. Partial excision of the leaflet and autopericard patch plasty was performed, and the VSD was directly closed. Postoperatively intravenous antibiotic therapy was given for periods of 6 weeks, and clinical course were uneventful in both cases. Local excision of vegetation and leaflet repair by autopericard patch plasty should be performed in cases with localized vegetation and minor valvular regurgitation.

Adult↗
PubMed1993

Differences in acetylcholine receptor-antibody interactions between extraocular and extremity muscle fibers.

There are two types of motor nerve innervation patterns and AChR distributions in human EOM: single and multiple. The latter is further divided into two subgroups that are restricted to EOM and are not found in limb muscles. Epitopes that are unique to EOM end-plates exist. Some OMG patients have antibodies that are specifically targeted to those epitopes. These antibodies are functionally active and can cause AChR loss in EOM end-plates. In addition to AChRs, specific components constructing the microenvironment surrounding them may also be involved in the susceptibility of EOM in myasthenia gravis.

Animals↗
PubMed1993

Group I introns in the liverwort mitochondrial genome: the gene coding for subunit 1 of cytochrome oxidase shares five intron positions with its fungal counterparts.

The complete nucleotide sequence of the mitochondrial DNA (mtDNA) from a liverwort, Marchantia polymorpha, contains thirty-two introns. Twenty-five of these introns possess the characteristic secondary structures and consensus sequences of group II introns. The remaining seven are group I introns, six of which happen to interrupt the gene coding for subunit 1 of cytochrome oxidase (cox1). Interestingly, the insertion sites of one group II and four group I introns in the cox1 gene coincide with those of the respective fungal mitochondrial interns. Moreover, comparison of the four group I introns with their fungal counterparts shows that group I introns inserted at identical genomic sites in different organisms are indeed related to one another, in terms of the peptide sequences generated from the complete or fragmental ORFs encoded by these introns. At the same time, the liverwort introns turned out to be more divergent from their fungal cognates than the latter are from one another. We therefore conclude that vertical transmission from a common ancestor organism is the simplest explanation for the presence of cognate introns in liverwort and fungal mitochondrial genomes.

Amino Acid Sequence↗
PubMed1993

Purification and characterization of kumamolysin, a novel thermostable pepstatin-insensitive carboxyl proteinase from Bacillus novosp. MN-32.

We have found a novel type of thermostable, pepstatin-insensitive carboxyl proteinase in the culture filtrate of Bacillus novosp. MN-32. The carboxyl proteinase, which was named kumamolysin, was purified about 8,300-fold by column chromatography including DEAE-Sepharose CL-6B, Sephadex G-100, and TSKgel DEAE-5PW. The purified kumamolysin gave a single band corresponding to 41 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The molecular mass of kumamolysin was estimated to be 40 kDa by gel filtration. The isoelectric point of kumamolysin was estimated to be pH 3.5 by isoelectric focusing. Kumamolysin has maximum proteolytic activity at 70 degrees C and at pH 3.0. Kumamolysin specifically hydrolyzed the Leu15-Tyr16 peptide bond in oxidized insulin B-chain (Km = 9.0 x 10(-5) M, Kcat = 71 s-1; at pH 3.0, 30 degrees C), and additional cleavage at Phe25-Tyr26 was detected at a considerably lower rate. Kumamolysin is insensitive to the known carboxyl proteinase inhibitors pepstatin, diazoacetyl-DL-norleucine methyl ester, and 1,2-epoxy-3-(p-nitrophenoxy)propane. Kumamolysin has no similarity to the thermostable acid protease thermopsin from Sulfolobus acidocaldarius (Lin, X.-L., and Tang, J. (1990) J. Biol. Chem. 265, 1490-1495). Thus, the substrate specificity, the inhibitor sensitivity, the molecular mass, and the thermostability all suggest that kumamolysin is a novel type of carboxyl proteinase.

Amino Acid Sequence↗
PubMed1993

Identification of a universal B cell epitope on DNA topoisomerase I, an autoantigen associated with scleroderma.

OBJECTIVE: To investigate the distribution of B cell autoepitopes of human DNA topoisomerase I (topo I), an autoantigen associated with scleroderma. METHODS: A complementary DNA clone, T1B, was used to produce recombinant proteins of topo I as beta-galactosidase fusion proteins. Immunoreactivity to these fusion proteins was then tested in 35 anti-topo I-positive sera from patients with scleroderma, by immunoblotting, enzyme-linked immunosorbent assay, and double immunodiffusion. RESULTS: One epitope was found to be universally recognized by all sera tested. Thirty-two of the samples recognized multiple antigenic regions, but sera from the remaining 3 patients recognized only this universal epitope, and in longitudinal studies of 1 of these 3 patients, the serum recognized only this epitope for more than 2 years, even though multiple, potent, antigenic regions were found on topo I. CONCLUSION: Recognition of multiple epitopes in most patients suggests that the topo I molecule itself would drive the autoimmunity on topo I. However, antigen-driven autoimmunity could not explain the production of the monoreactive anti-topo I antibody seen in the 3 patients. We thus hypothesize that there is a process whereby recognition of the universal epitope by cross-reaction develops into antigen-driven autoimmunity.

Autoantibodies↗
PubMed1993

DNA-DNA subtractive cDNA cloning using oligo(dT)30-Latex and PCR: identification of cellular genes which are overexpressed in senescent human diploid fibroblasts.

We previously reported an efficient method for subtractive cDNA cloning using oligo(dT)30-Latex and polymerase chain reaction (PCR) (E. Hara et al., Nucleic Acids Res. 19, 7097-7104, 1991). The subtraction was performed by hybridization between mRNA of cell type B and the cDNA made from mRNA of cell type A using an oligo(dT)30 primer covalently linked to Latex particles in an Eppendorf tube. The mRNA common to both types of cells could be removed by a brief centrifugation. In the present paper, the method was improved by using the sense strand DNA instead of mRNA for hybridization to cDNA covalently linked to the particles to minimize mRNA degradation and by optimizing the hybridization condition. The sense strand DNA was made from cDNA-oligo(dT)30-Latex by asymmetric PCR. Using the improved method, a subtractive cDNA library with longer cDNA inserts was successfully constructed with higher probability than the original method.

Animals↗
PubMed1993

Differential activation of cyclin and cyclin-dependent kinase genes by adenovirus E1A12S cDNA product.

The differential activation of cyclin and cyclin-dependent kinase genes by the adenovirus E1A gene product (E1A) or serum factors was studied with a rat 3Y1 derivative cell line, g12-21, in which the E1A12S cDNA can be expressed in response to dexamethasone (dex). The induction of DNA synthesis in quiescent g12-21 cells occurred within 12 h after serum stimulation, while it occurred within 8 h after treatment with dex. The expression of cyclin D1 and E genes in the serum-stimulated cells was induced in mid G1 and mid to late G1, respectively, while that of the cyclin D1 gene was not induced and the induction of the cyclin E gene was shifted to the G1/S boundary in the dex-treated cells. The cdk2 gene was induced in late G1 and cdc2 and cyclin A genes at the G1/S boundary in both serum-stimulated and dex-treated cells. These results suggest that E1A skips cell cycle events which normally occur in early to mid G1 and may directly activate late-response genes. Analysis of the transcription factor E2F complexes formed in the promoter regions of cdc2 and dihydrofolate reductase genes showed that the amount of complexes formed is maximal at the G1/S boundary, but decreases in S phase when these genes are transcribed extensively.

Adenovirus E1A Proteins↗
PubMed1993

Cotranscriptional expression of mitochondrial genes for subunits of NADH dehydrogenase, nad5, nad4, nad2, in Marchantia polymorpha.

Three genes for the subunits of the NADH dehydrogenase (nad5, nad4, and nad2) are tandemly clustered on the liverwort mitochondrial genome. Their gene products showed high levels of amino acid sequence identity with the corresponding subunits from higher plant mitochondria (82.8-84.4%), and significant levels of identity with those from liverwort chloroplast (32.0-33.5%). Podospora anserina mitochondria (21.4-45.9%), and human mitochondria (18.4-27.9%). In addition, these three subunits from liverwort mitochondria have conserved amino acid residues in their central regions. The gene nad5 is interrupted by a 672 bp group I intron, while genes nad4 and nad2 are interrupted by group II introns of 899 bp and 1418 bp, respectively. Northern blot analysis using exon-intron specific probes indicated that these three genes are transcribed as a single precursor mRNA of 9.6 kb in length and are processed into mature mRNA molecules in liverwort mitochondria. Several regions of this nad gene cluster are repeated in the liverwort mitochondrial genome.

Amino Acid Sequence↗
PubMed1993

Benign fibrous histiocytoma of the stomach: report of a case.

We report herein an extremely very rare case of primary benign fibrous histiocytoma of the stomach found in a 56-year-old man who presented with a 2-week history of nausea and anorexia. Gastrointestinal X-rays and endoscopy revealed a protruding lesion in the stomach, but biopsies failed to demonstrate the nature of the tumor. Histopathologic investigation of the resected tumor showed the typical features of benign fibrous histiocytoma: Consisting of an admixture of spindly fibroblast-like and roundish histiocyte-like cells arranged in a storiform pattern. Furthermore, immunohistochemical staining with alpha-1-antichymotrypsin was positive for histiocyte-like cells in the tumor. The patient has shown no evidence of recurrence in the 2 years of follow-up since his operation.

Histiocytoma, Benign Fibrous↗
PubMed1993

Effect of hormone replacement therapy on spinal bone mineral density and T lymphocyte subsets in premature ovarian failure and Turner's syndrome.

OBJECTIVE: Our purpose was to evaluate the effect of hormone replacement therapy (HRT) on bone metabolism and the immunological change in premature ovarian failure (POF) and Turner's syndrome. METHOD: The study was conducted on 17 POF patients, 10 Turner's syndrome patients and 35 control subjects aged 20-40 years. Bone mineral density (BMD) of lumbar vertebra by dual energy X-ray absorptiometry, serum bone metabolic parameters and T lymphocyte subsets in the peripheral blood were investigated. RESULT: The untreated and treated patients of POF (0.829 +/- 0.077, 0.918 +/- 0.094 g/cm2) and the untreated and treated patients of Turner's syndrome (0.647 +/- 0.037, 0.885 +/- 0.148 g/cm2) showed spinal osteopenia compared with the control group (1.039 +/- 0.107 g/cm2). They showed a significantly lower percentage of CD4 and a ratio of CD4/CD8 in T lymphocytes as compared with the control group before HRT. CONCLUSION: POF and Turner's syndrome patients showed marked spinal osteopenia and abnormal T lymphocytes subsets. HRT slightly improved their BMD and immunological status.

Absorptiometry, Photon↗
PubMed1993

Incident angle dependence of proton response of CR-39 (TS-16) track detector.

The proton response of the TS-16 type of CR-39 plastic nuclear track detector has been studied with accelerated and fast neutron induced protons in vacuum and in air. The diameters of etched tracks were measured as a function of etching time and the etch rate ratio and the etch induction layer were determined from the growth curve of the diameter using a variable etch rate ratio model. In the case of the accelerated protons in vacuum an anomalous incident angle dependence of the response is observed.

Calibration↗
PubMed1993

An in vivo study of the replication origin in the influenza virus complementary RNA.

A new in vivo replication system for influenza virus was developed by using the clone 76 cell line, in which the viral RNA polymerase and nucleoprotein genes can be expressed in response to dexamethasone. The chimeric NS-chloramphenicol acetyltransferase (CAT) RNAs in the sense and antisense orientations positioned between the 5'- and 3'-terminal sequences of the influenza virus RNA segment 8 can be replicated [both genomic RNA (vRNA) and complementary RNA (cRNA) were transcribed] in the clone 76 cells treated with dexamethasone. These data indicate that three RNA polymerase proteins (PB1, PB2, and PA) and nucleoprotein are sufficient for replication of the influenza virus genome. Analysis of mutant cRNAs containing a base-substitution or a deletion in the 3'-conserved terminal 13 nucleotides revealed that important cis elements in the cRNA for vRNA synthesis reside at positions 2, 3, and 7 to 13 nucleotides from the 3'-end.

Animals↗