Biomedical subjects

S Oda

Publications and source records attributed to S Oda.

At least 109 records · Page 6Linked to original sources

PubMed1998

Chromosomal segregation and fertility in Robertsonian chromosomal heterozygotes of the house musk shrew (Suncus murinus, Insectivora, Soricidae).

Crucial to our understanding of chromosomal variation and evolution in mammals are detailed studies of chromosomal heterozygotes, with analyses of chromosomal segregation and chromosome-derived infertility. We studied segregation and fertility in hybrids between karyotypic races of the house musk shrew Suncus murinus. These individuals were heterozygous for up to five Robertsonian fusions (Rbs) and an insertion of heterochromatin in an autosome. All variant chromosomes showed Mendelian segregation and all Rbs segregated independently of each other in the progeny of double heterozygotes. Litter size in single and even multiple Rb heterozygotes was no smaller than that in the less fertile parental strain. The effects of genetic background were more important in determining litter size than Rb heterozygosity for the shrews that we examined.

Animals↗

PubMed1998

Cellular injury score for multiple organ failure severity scoring system.

BACKGROUND: Cellular Injury Score (CIS) is an index of cellular injury, being calculated from three parameters of intracellular metabolism: arterial ketone body ratio, osmolality gap, and blood lactate. METHODS: The usefulness of CIS as a severity scoring system for patients with multiple organ failure was prospectively evaluated in 157 consecutive patients with MOF (58 survivors, 99 nonsurvivors). RESULTS: CISs in nonsurvivors were significantly higher compared with those in survivors throughout the clinical courses. CIS was significantly correlated with the number of failing organs and mortality rate. The optimal cutoff point of CIS from receiver operating characteristics curve analysis was 4 for the maximal value during the clinical course. The changes in CIS well reflected the severity of injury in survivors and nonsurvivors who died within 2 weeks. CONCLUSION: CIS could be a useful index for mortality risk prediction and is potentially applicable as a severity scoring system for individual patients with MOF.

3-Hydroxybutyric Acid↗

PubMed1998

Chromosome pairing in inter-racial hybrids of the house musk shrew (Suncus murinus, Insectivora, Soricidae).

Two chromosome races of the house shrew Suncus murinus that differ from each other for five Robertsonian translocations (8.17, 9.13, 10.12, 11.16, and 14.15), heterochromatic insertions in chromosomes 7 and X, and multiple rearrangements in the Y chromosome were crossed and then intercrossed in captivity to produce a hybrid stock. Electron-microscopic analysis of synaptonemal complexes in fertile and sterile hybrid males was carried out. Meiosis in sterile males did not progress beyond pachytene and was severely disrupted. Meiotic arrest was not determined by structural heterozygosity: heterozygotes for all variant chromosomes distinguishing two parental races were found in both sterile and fertile male hybrids. Fertile hybrids demonstrated an orderly pairing of all chromosomes. In heterozygotes for Robertsonian fusions, completely paired trivalents were formed between the Robertsonian metacentrics and homologous acrocentrics. In heterozygotes for chromosome 7, bivalents with a small buckle were observed in a small fraction of pachytene cells. No differences were found in the morphology and pairing pattern of sex bivalents, composed of the X and Y chromosomes derived from the same or different parental races. Univalents, multivalents, and associations between X and Y chromosomes and autosomal trivalents, as well as associations of autosomal trivalents with each other, were observed in a small fraction of the pachytene cells of fertile males. Our results indicate that the system controlling male sterility in interracial hybrids of S. murinus is of genic rather than of chromosomal type.

Animals↗

PubMed1998

Inheritance of male hybrid sterility in the house musk shrew (Suncus murinus, Insectivora, Soricidae).

Two geographic races of the house musk shrew (Suncus murinus) were crossed and intercrossed in the laboratory. Many cases of male sterility were detected among the hybrids. Segregation analysis of the pedigree data showed that the inheritance of male sterility in interracial hybrids of S. murinus can be described within the framework of monogene polyallele model with sterility of a single allele combination. This model is similar if not identical to that proposed by Dobzhansky and Muller.

Alleles↗

PubMed1998

Parvalbumin immunoreactive neurons in the main olfactory bulb of the house musk shrew, Suncus murinus.

The distribution, morphological features, and postnatal development of parvalbumin (PV) immunoreactive neurons in the main olfactory bulb (MOB) of the house musk shrew, Suncus murinus, were studied to report for the first time on PV positive bulbar interneurons in the order Insectivora. In adult animals, PV neurons are distributed in the glomerular layer (GL), the external plexiform layer (EPL), the internal plexiform layer (IPL) and the granule cell layer (GCL) of the MOB. These neurons were identified as a subpopulation of periglomerular cells and perinidal cells [Alonso et al., 1995] in the GL and at the GL-EPL border, respectively, and as bipolar and multipolar neurons in the EPL and four types of the interneurons (horizontal cells, Cajal cells, Golgi cells, and bitufted cells) in the layers deeper than the mitral cell layer. During development of PV neurons, neurons exhibiting extremely faint PV immunoreactivity first appeared in the GCL at postnatal day 14 and increased markedly in number and intensity of their PV immunoreactivity from postnatal days 14 to 28. At postnatal day 21, PV neurons were identified as periglomerular cells in the GL, perinidal cells at the GL-EPL border, and morphologically unidentifiable neurons in the EPL, IPL and GCL. At postnatal day 28, PV neurons exhibited a nearly adult pattern with respect to distribution and structural features. The present results strongly suggest that a wide variety of PV positive neurons in the MOB of the house musk shrew may develop postnatally.

Animals↗

PubMed1998

Production of ethyl (R)-2-hydroxy-4-phenylbutanoate via reduction of ethyl 2-oxo-4-phenylbutanoate in an interface bioreactor.

Ethyl (R)-2-hydroxy-4-phenylbutanoate [(R)-EHPB], a useful intermediate for the synthesis of various anti-hypertension drugs, was produced via microbial reduction of ethyl 2-oxo-4-phenylbutanoate [EOPB] in an interface bioreactor. Rhodotorula minuta IFO 0920 and Candida holmii KPY 12402 were selected as the best type culture and isolated yeasts, respectively. The highest enantiomeric excess of (R)-EHPB produced by R. minuta and C. holmii were 95 and 94%, respectively. C. holmii was used for the reduction of EOPB in a pad-packed interface bioreactor (inner volume, 3 liter). After incubation for 4 days, 4.4 g of (R)-EHPB was obtained via extraction with methanol followed by column chromatography. The overall yield, chemical purity, and enantiomeric excess of (R)-EHPB were 58%, 99.1%, and 90%, respectively.

Agar↗

PubMed1998

3D and 4D atlas system of living human body structure.

A reference system for accessing anatomical information from a complete 3D structure of the whole body "living human", including 4D cardiac dynamics, was reconstructed with 3D and 4D data sets obtained from normal volunteers. With this system, we were able to produce a human atlas in which sectional images can be accessed from any part of the human body interactively by real-time image generation.

Anatomy, Cross-Sectional↗

PubMed1998

[Delayed ischemic neurological deficit that developed over 15 days after subarachnoid hemorrhage].

We retrospectively studied subarachnoid hemorrhage (SAH) patients with delayed ischemic neurological deficit (DIND), and analyzed the factors causing extremely late onset of deficits occurring over 15 days after onset of the SAH. Among 605 patients with SAH, 201 (33%) developed DIND. Among DIND patients, 137 had undergone early aneurysm surgery. In these 137 patients, onset date of DIND was definite in 131 patients. Six patients (5%) developed DIND over 15 days after SAH. All 6 had asymptomatic angiographical vasospasm and infections, most often meningitis, before the onset of DIND. Compared with cases in which there was ordinary onset of DIND, other statistically significant factors among these 6 patients were intracerebral hemorrhage, sepsis and meningitis. We suspect that DIND were manifested subclinically in the early period because of the associated hyperdynamic hemodynamics resulting from sepsis in these patients.

Adult↗

PubMed1998

[A new microsatellite instability analysis using fluorescent primers and laser scanning].

To demonstrate the instability of microsatellite sequences, which have been linked to DNA mismatch repair deficiency and indicate a high risk of carcinogenesis, polymerase chain reaction (PCR) and electrophoretic analysis have been used. However, the electrophoretic profiles of PCR-amplified microsatellite sequences are often too complicated, and the conventional method using autoradiography has critical problems in detection characteristics and migration accuracy. First, we made use of fluorescence-labeled PCR and laser scanning to detect bands quantitatively. Second, we characterized Taq polymerase-dependent modification of the amplified microsatellite sequences and optimized the electrophoretic profiles by enzymatic modification with T4 DNA polymerase. Third, we developed a dual fluorescence co-electrophoresis system, in which both samples derived from cancer and normal tissues are electrophoresed in the same lane, in order to minimize migration errors. Furthermore, we classified all of the observed patterns of microsatellite alteration and set up new criteria for assessing microsatellite instability. Using the system developed here and the criteria we proposed, a precise judgment can be made and rates of positivity in various human malignancies may be corrected.

DNA-Directed DNA Polymerase↗

PubMed1998

[The relationship between maintenance dose of vecuronium and the recovery time from the muscle relaxation].

We investigated the relationship between maintenance bolus dose of vecuronium bromide (Vb) and the recovery time measured by TOF Guard in patients anesthetized with isoflurane (1.2-2.0%)-N2O-O2 (GOI group, n = 19) and epidural anesthesia (2% mepivacaine) plus isoflurane (0.5%)-N2O-O2 (EPI group, n = 14). In both groups, anesthesia was induced with propofol 2 mg.kg-1 and Vb 0.1 mg.kg-1 and ventilation was controlled to keep end tidal CO2 between 35-40 mmHg. When the muscle relaxation recovered to 25% of train-of four ratio (TOFR), doses of Vb 0.06, 0.04 or 0.02 mg.kg-1 were administered. Recovery time to TOFR 25% at each Vb dose (T 0.06, T 0.04 and T 0.02 respectively) was observed. T 0.02, T 0.04 and T 0.06 in GOI group were 36.7 +/- 3.2, 50.7 +/- 4.3 and 60.7 +/- 5.02 min (mean +/- SE), respectively and those in EPI group were 42.6 +/- 2.53, 52.2 +/- 2.51 and 59.9 +/- 3.22 min, respectively. There were no significant differences in the recovery time between these two groups. In both groups, although the recovery time to TOFR 25% was prolonged significantly in proportion to the increasing doses of Vb, the increase did not correlate with the dose of Vb. We suggest that frequent administration of Vb 0.02 mg.kg-1 decreases the total amount of Vb to keep TOFR within 25%.

Aged↗

PubMed1997

[Computer-aided occupational health education for post-graduates].

Nowadays, it's inevitable that occupational physicians enhance the activities in the field of occupational health through the use of the computer. Moreover, computer-aided self-education programs are one of the most useful tools for occupational physicians because they must learn a large volume of multidiscipline expertise for occupational health. Thus, we tried to apply a practical training program using the software of our own making in the post-graduate training course of fundamental occupational health. One is a self-education software for the study of electrocardiograms, and the other is a simple system to manage the serial data of a medical checkup and the reports of an inspection tour in the workplace. By this system one is also able to receive information such as a chest X-ray via the internet. Twenty-three students appraised our programs as for the contents (easily understandable, adequate volume); teacher's attitudes (enthusiastic approach to the training, enough time for questions, attention to the reaction of the class) and free comments. Because 4.3 points (at most 5.0) on an average was obtained, we are encouraged to make multimedia instructional materials on occupational health.

Computer Communication Networks↗

PubMed1997

Large-scale immunohistological staining using polyethylene glycol-embedded sections mounted on 96-well plates for monoclonal antibody screening.

We have developed a rapid, large-scale immunohistological staining method for monoclonal antibody screening. Sections embedded in polyethylene glycol are mounted on 96-well plates and then subjected to immunological procedures using a 96-well format. With this method, we can prepare 10 plates (960 samples) in 1 day and then perform immunohistological procedures in 1 day by using an enzyme-linked immunosorbent assay-like 96-well format. Thus, we can avoid difficulties seen in conventional immunohistological methods that use sections mounted on glass slides. This method offers high-throughput screening of monoclonal antibodies. In addition, it has the potential of being automated.

Animals↗

PubMed1997

Precise assessment of microsatellite instability using high resolution fluorescent microsatellite analysis.

The instability of microsatellite sequences dispersed in the genome has been linked to a deficiency in cellular mismatch repair. This phenotype has been frequently observed in various human neoplasms and is regarded as a major factor in tumorigenesis. To demonstrate alterations in microsatellite sequences, polymerase chain reaction (PCR) and electrophoretic analysis are techniques often used. However, the electrophoretic profiles of PCR-amplified microsatellite sequences have not been well characterized. Moreover, the conventional method using autoradiography has critical problems in detection characteristics and migration accuracy. We made use of fluorescence-labeled PCR and laser scanning with linear detection characteristics, so as to detect bands quantitatively. Next, we characterized Taq polymerase-dependent modification of the amplified microsatellite sequences, using artificially synthesized microsatellite alleles and we optimized the electrophoretic profiles by enzymatic modification with T4 DNA polymerase. We developed a dual fluorescence co-electrophoresis system, in which both samples derived from cancer and normal tissues are electrophoresed in the same lane, in order to minimize migration errors. These improvements remarkably facilitate precise and objective assessments of microsatellite instability. Analyzing many positive cases in cell lines and tissue specimens, we classified all the patterns of microsatellite alteration and set up new criteria for assessing microsatellite instability.

Adenocarcinoma↗

PubMed1997

Overexpression of the MTA1 gene in gastrointestinal carcinomas: correlation with invasion and metastasis.

The mta1 gene is a recently identified novel candidate metastasis-associated gene. The deduced amino acid sequence contains an src homology-3 domain binding motif, a zinc finger motif and possible phosphorylation sites, suggesting that this gene is involved in signal transduction or regulation of gene expression. The purpose of our study was to examine the mRNA expression levels of the MTA1, the human homologue of the rat mta1 gene in colorectal and gastric carcinomas and thus to evaluate the relevance of the expression of this gene to human carcinoma progression. The expression of MTA1 mRNA in 36 colorectal and 34 gastric carcinoma samples was compared with that in corresponding normal mucosa tissues by semi-quantitative reverse-transcription polymerase chain reaction (RT-PCR) and the results were compared with clinico-pathologic data. A relative overexpression of MTA1 mRNA (tumor/normal ratio > or = 2) was observed in 14 of 36 (38.9%) colorectal carcinomas and 13 of 34 (38.2%) gastric carcinomas. Clinico-pathologic correlations demonstrated that in colorectal carcinomas, tumors overexpressing MTA1 mRNA exhibited a significantly deeper wall invasion and a higher rate of metastasis to lymph nodes, and tended to be at an advanced Dukes' stage with frequent lymphatic involvement. In gastric carcinomas, the tumors overexpressing MTA1 mRNA showed significantly higher rates of serosal invasion and lymph node metastasis and tended to have a higher rate of vascular involvement. Our data suggest that overexpression of the MTA1 gene correlates with tumor invasion and the presence of metastases and that a high expression of MTA1 mRNA may be a potential indicator for assessing the malignant potential of colorectal and gastric carcinomas.

Aged↗

PubMed1997

Lymph node metastasis and relation to tumor growth potential and local immune response in advanced gastric cancer.

To evaluate the relation between the degree of lymph node metastasis and the growth potential of tumour cells and the local immune function in gastric cancer, we analyzed data on 444 patients with advanced serosally invasive gastric cancer who underwent curative gastrectomy. Tumour growth potential was evaluated based on the value proliferating cell nuclear antigen (PCNA) in the primary tumour, and dendritic cell infiltration into the tumour was determined as an indicator of local immune function. The values of PCNA labeling in the primary tumour increased and the infiltration of dendritic cells into the tumour decreased in relation to the extent of lymph node metastasis. High growth potential and low immune function were seen in cases with n3 lymph node metastasis. There was a reverse relation between the PCNA labeling index and dendritic cell infiltration. A variety of forms of recurrence was noted in patients with lymph node metastasis while the prognosis was less favorable, in relation to the degree of lymph node metastasis. Thus, the potential for nodal spread appears to be associated with the growth potential of tumour cells and with the local immune status of the tumour.

Cell Count↗

PubMed1997

Distinct phenotype of leukemic T cells with various tissue tropisms.

There is an emerging concept, the validity of which remains to be proven, that preferential expression of selective adhesion molecules on particular T cell subsets may result in tissue-specific migration. L-selectin, cutaneous lymphocyte-associated Ag (CLA), and integrin alpha4beta7 are proposed to be involved in selective migration of T cell subsets into peripheral lymph nodes, skin, and gastrointestinal mucosa, respectively. Adult T cell leukemia (ATL) is associated with lymphoid infiltration of tissues and secondary lymphoid organs. To clarify the role of these putative homing molecules in vivo, we assessed their expression on circulating ATL cells from patients with lymph node, skin, and gut involvement. L-selectin expression was significantly higher on peripheral ATL cells in patients with lymphadenopathy than in patients without it. CLA was highly expressed on peripheral ATL cells compared with normal T cells: its expression was also significantly higher on peripheral ATL cells from patients with skin involvement compared with cells from patients without it. beta7 was particularly highly expressed on peripheral ATL cells from patients with gastrointestinal involvement. In summary, the differential expression of beta7 and beta1 on peripheral ATL cells correlates with the presence of gastrointestinal involvement. Similarly, the presence of skin involvement is associated with the expression of CLA(high)beta7low on peripheral ATL cells. These results, which are consistent with the molecules CLA and alpha4beta7 mediating preferential T cell migration to the skin and gastrointestinal mucosa, respectively, may allow for a refinement of the classification of lymphoid neoplasms on the basis of differential expression of homing molecules.

Adult↗

PubMed1997

Molecular cloning and expression of murine smooth muscle myosin heavy chains.

The nucleotide and deduced amino acid sequences of two isoforms of mouse smooth-muscle myosin heavy chain (SM1 and SM2) were determined. SM1 (6175 bp) and SM2 (6214 bp) cDNA contained a single open reading frame that encodes 1972 and 1938 amino acids (227,056 Da and 223,294 Da), respectively. Smooth muscle myosin heavy chain mRNA was expressed highly in smooth muscle tissue (small intestine) and weakly in heart and lung. Each of SM1 and SM2 cDNA was transfected and expressed in CHO cells. The expressed myosin heavy chains were detected with an antibody raised against smooth muscle myosin heavy chains and showed the same mobility as the native smooth muscle myosin heavy chains in SDS-PAGE.

Amino Acid Sequence↗

PubMed1997

Interleukin-6 inhibits long-term potentiation in rat hippocampal slices.

The effects of recombinant human interleukin-6 (rhIL-6) on long-term potentiation (LTP) induced in the Schaffer collateral/commissural-CA1 pathway were examined using rat hippocampal slices. Field excitatory postsynaptic potential was recorded in the stratum radiatum of the CA1 region. Ten-min applications of rhIL-6 (50-2000 U/ml), started 5 min before the tetanus, significantly inhibited the induction of LTP, and in high doses of rhIL-6 also inhibited short-term potentiation (over 200 U/ml) and post-tetanic potentiation (over 500 U/ml). The effects of rhIL-6 (500 U/ml) were completely abolished by the preincubation of the slices with monoclonal anti-IL-6 receptor antibody (16 microg/ml) for 2 h. Heat-inactivated rhIL-6 had no effect on the synaptic potentiation. RhIL-6 affected neither the previously established LTP nor the basal synaptic transmission. These findings indicated that rhIL-6 modulated synaptic potentiation through the IL-6 receptor-mediated process in the hippocampus, probably by affecting post- and presynaptic sites in the CA1 region. The possible mechanisms of the IL-6-induced suppression of the synaptic potentiation were discussed.

Action Potentials↗