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Biomedical subjects

K Tsuji

Publications and source records attributed to K Tsuji.

At least 523 records · Page 29Linked to original sources
PubMed1990

[Cimetidine-induced aplastic anemia complicated with nonbacterial thrombotic endocarditis and cerebral infarction].

A 72-year-old woman had been given cimetidine 400mg/day for her gastritis since June 17, 1987. On August 8, she developed oral bleeding. Peripheral blood showed pancytopenia (WBC 1,900/microliters, RBC 208 x 10(4)/microliters, Plt 0.8 x 10(4)/microliters) and bone marrow studies revealed markedly depressed hematopoiesis. Bolus methylprednisolone and high dose gamma globulin were administered, but not effective. On December 11, 1987, she lapsed into coma and died three days later. Autopsy disclosed nonbacterial thrombotic endocarditis and cerebral infarction.

Aged↗
PubMed1990

Mapping of the HLA-D region by pulsed-field gel electrophoresis: size variation in the DQ-DR interval.

Pulsed field gel electrophoresis (PFGE) was used to construct genomic maps of different HLA-D region haplotypes. In the course of these experiments a new HLA class II beta chain sequence, DV beta, was located close to DX alpha between DX alpha and DQ beta. All other markers studied, from the DP, DZ/DO, DQ and DR subregions, were consistent in their positions in the haplotypes studied but the distance between DQ alpha and DR alpha differed in various haplotypes. For example, in DR7 (MANN) this distance was approximately 380 kb, but in the DR2 haplotype (AKIBA), it was 270 kb. This may be due to variations, either in the number of duplicated DRB genes or in the length of other uncharted DNA, in the HLA-D region.

DNA Probes↗
PubMed1990

[The prognostic significance of nuclear DNA content in non-small-cell lung carcinoma].

The nuclear DNA content of paraffin-embedded specimens of primary non-small-cell lung carcinomas was analysed using flow cytometry in 210 patients (80 squamous cell carcinomas, 99 adenocarcinomas, 19 large cell carcinomas and 15 others). The relationship between nuclear DNA content and prognostic factors was studied using multivariate analysis with Cox's proportional hazard model. 1) The frequency of DNA aneuploidy was 77.3% among 210 patients, and it significantly (p less than 0.05) increased with advanced stage and the presence of lymph node metastasis. 2) The patients with DNA aneuploid tumors had a significantly (p less than 0.001) less favorable prognosis than those with DNA diploid tumors among 179 patients with non-small-cell lung carcinomas. Similar results were demonstrated in 79 patients with stage I carcinomas and in 85 patients who underwent absolute curative resection. 3) Multivariate analysis using Cox's proportional hazard model showed that DNA ploidy was an independent prognostic factor for survival. Especially in the patients with absolute curative resection, DNA ploidy was the most important prognostic factor. In conclusion, flow cytometric nuclear DNA content analysis provided useful biological information, and DNA ploidy was an important and major independent prognostic factor in non-small-cell lung carcinoma.

Adult↗
PubMed1990

[A case report of hyperosmolar hyperglycemic non-ketotic coma after aortic valve replacement].

A 56-year-old man without a past history of diabetes mellitus underwent aortic valve replacement. On the 8th postoperative day, the patient became confused with a peak blood glucose level of 600 mg/dl and peak serum osmolarity level of 411 mOsm/l, without ketotic urine. The diagnosis of hyperosmolar hyperglycemic non-ketotic coma (HHNKC) was made, and the patient was immediately treated with massive infusion of 0.45% saline water and continuous insulin administration, and the patient could completely recover. It is important to prevent and keep in mind the complication of HHNKC for the postoperative care after open heart surgery.

Aortic Valve↗
PubMed1989

Stimulation of connective tissue-type mast cell proliferation by crosslinking of cell-bound IgE.

Crosslinking of cell-bound IgE on mouse connective tissue-type mast cells (CTMC) by multivalent antigen or anti-IgE antibody induced clonal growth of CTMC in methylcellulose culture containing IL-3. Continuous presence of antigen, IgE antibody, and IL-3 in culture was required for extensive proliferation of CTMC. Optimal concentrations of antigen and anti-IgE antibody for proliferation of sensitized CTMC approximately corresponded to those for maximal histamine release from the cells, and it was observed that most dividing cells stimulated by antigen had pericellular degranulation halos in culture. Experiments of both single cell culture and serum free culture provided evidence for a direct effect of antigen stimulation on proliferation of CTMC. Neither accessory cells nor some factors in FCS were required for the clonal growth of CTMC in our culture condition. Compound 48/80, a direct stimulator of CTMC, also triggered histamine release from CTMC but failed to support their proliferation. These results suggest that stimulation of CTMC via IgE receptors not only triggers the release of chemical mediators from the cells but induces clonal growth of CTMC in the presence of IL-3. Our data indicate the possibility that antigen stimulation may play another role in the proliferation of CTMC.

Animals↗
PubMed1989

Effect of butylated hydroxyanisole pretreatment on aflatoxin B1-DNA binding and aflatoxin B1-glutathione conjugation in isolated hepatocytes from rats.

The effect of 2(3)-tert-butyl-4-hydroxyanisole (BHA) pretreatment of rats on both aflatoxin B1 (AFB1)-DNA binding and AFB1-glutathione has been examined with isolated hepatocytes and in intact rats. Young male F344 rats were fed AIN-76A diet with or without 0.75% BHA for 2 weeks. Even though there were no significant differences in either cytochrome P-450 or reduced glutathione contents, there were marked differences in AFB1 metabolism in isolated hepatocytes from these two groups. Thus, at the 33 nM AFB1 level, AFB1-DNA binding was 3-fold higher in control compared to BHA-treated hepatocytes whereas AFB1-glutathione conjugation was 5-fold higher in treated compared to controls. Even at higher AFB1 concentrations (2 and 10 microM), DNA binding was 4-6-fold higher in controls whereas thiol conjugation was 5-9-fold higher in treated compared to control hepatocytes. Addition of 0.5-1.0 mM diethylmaleate did not have any significant effect in control hepatocytes whereas its presence produced about 70-100% increase in DNA binding with 65-80% inhibition of thiol conjugation in treated hepatocytes. Addition of 1 mM styrene oxide caused 75-100% and 4-8-fold increase in AFB1-DNA binding in control and treated hepatocytes, respectively, with corresponding decreases in thiol conjugation. In intact rats, BHA treatment reduced hepatic AFB1-DNA binding to 15% of controls with concomitant increase in biliary excretion of AFB1-reduced glutathione conjugate. It appears that the induced cytosolic GSH S-transferases after BHA treatment of rats play a significant role in inhibiting hepatic AFB1-DNA binding and AFB1 hepatocarcinogenesis presumably by inactivation of the reactive AFB1-epoxide.

Aflatoxin B1↗
PubMed1989

A mechanism of inhibition of aflatoxin B1-DNA binding in the liver by phenobarbital pretreatment of rats.

The effect of phenobarbital (PB) pretreatment of rats on both hepatic aflatoxin B1 (AFB1)-DNA binding and AFB1-glutathione (AFB1-SG) conjugation have been examined in studies in vivo and in vitro. Male Sprague-Dawley rats fed a commercial diet with 0.1% PB in their drinking water for 1 week had total wet liver weight and microsomal protein content about 27% and 38% higher, respectively, than controls. Hepatic cytochrome P-450 content, microsomal cytochrome P-450 mediated AFB1 binding to exogenous DNA and formation of hydroxy metabolites of AFB1 were also about threefold higher in PB-treated rats and cytosolic reduced glutathione S-transferase activities were about doubled. Microsome-mediated AFB1-DNA binding, when examined at 2 microM and 10 microM levels of AFB1, was inhibited two-to threefold more by cytosols of treated rats whereas AFB1-SG conjugation was two- to threefold higher by cytosols of treated rats. In reconstitution experiments with 2 microM AFB1, with intact nuclei serving as a source of endogenous DNA, addition of microsomes from either group generated a large amount of AFB1-DNA binding (68-105 pmol) and a smaller amount of AFB1-SG conjugate (12-21 pmol). The presence of cytosol from the controls reduced AFB1-DNA binding to a much lesser extent than the cytosol from the treated group whereas AFB1-SG conjugation was much higher with the cytosol from the treated group. These results are in agreement with the studies in vivo. In isolated hepatocytes at 33 nM, 2 microM and 10 microM AFB1 levels, AFB1-DNA binding was decreased 50 to 70% by prior PB-treatment whereas AFB1-SG conjugation was two- to threefold higher in treated compared to control hepatocytes. In hepatocytes, addition of 1 mM diethylmaleate increased DNA binding two- to threefold with a corresponding decrease in AFB1-SG conjugation. Addition of 1 mM styrene oxide caused 5- to 10-fold increases in AFB1-DNA binding at levels of AFB1 of 33 nM and 2 microM; but at 10 microM AFB1, increases in AFB1-DNA binding were two- to threefold. In intact rats, PB treatment reduced hepatic AFB1-DNA binding to 30% of controls with concomitant increase in biliary excretion of AFB1-SG conjugate. It appears that the induced cytosolic GSH S-transferases after PB treatment of rats plays a significant role in inhibiting hepatic AFB1-DNA binding and hepatocarcinogenesis presumably by inactivation of the reactive AFB1-epoxide.(ABSTRACT TRUNCATED AT 400 WORDS)

Aflatoxin B1↗
PubMed1989

Analysis of gene structure and antigen determinants of DR2 antigens using DR gene transfer into mouse L cells.

Three HLA class II DR beta genes and one DR alpha gene from the DR2 haplotype were cloned in cosmid vectors. The DR beta II gene might be a pseudogene lacking the first exon that encodes the leader peptide. The DR beta I and DR beta III genes were expressed, together with the DR alpha-chain, after transfection into mouse L cells. Restriction enzyme mapping of the DR beta genomic clones and reactivity of their products expressed on the L cell transfectant against mAb showed that the DR beta I and DR beta III genes encoded the nonpolymorphic and polymorphic DR beta chain, respectively. This arrangement is the reverse of that observed in other haplotypes, such as DR3, 4 and 6. The alignment of the HLA class II genes including the DR beta genes on the chromosome 6, however, was consistent with other haplotypes, e.g., centromere-DX beta-DX alpha-DV beta-DQ beta-DQ alpha-DR beta I-DR beta II- DR beta III-DR alpha-telomere. These results suggest that the susceptibility to mutations or gene conversions responsible for genetic polymorphisms depends on the gene itself and not on its location. Furthermore, absorption experiments of anti-DR2 allosera by the DR alpha/DR beta transfectants revealed that the so-called DR2 specificities were determined by multiple epitopes although both the DR beta I and DR beta III genes behaved similarly with DR2-specific antibodies.

Absorption↗
PubMed1989

Stochastic model for multipotent hemopoietic progenitor differentiation.

In this study, the authors propose a stochastic model for multipotent hemopoietic progenitor differentiation, which assumes that there is a fixed probability (P) that a progenitor with a potential for differentiation along a particular lineage maintains the potential in each cell division in each daughter cell, and this differentiation process of each lineage proceeds independently. To examine the applicability of this model, a sequential micromanipulation of paired progenitors was carried out and followed by cytological examination of the cells contained in the colonies derived from these progenitors; then calculation was made of the ratio of the number of paired colonies containing cell(s) with a particular lineage to the number of paired colonies in which only one colony contained cell(s) with the lineage at the first and second cell division. The ratios were similar at the first and second cell division within each lineage. Furthermore, the frequences of each lineage in multilineage hemopoietic colonies were calculated using the P values obtained from these micromanipulation experiments. The expected frequencies were similar to those in the actual experiments. These results suggested that the stochastic model was applicable to multipotent hemopoietic progenitor differentiation.

Cell Differentiation↗
PubMed1989

Immunogenetic heterogeneity in type 1 (insulin-dependent) diabetes among Japanese HLA antigens and organ-specific autoantibodies.

HLA phenotypes and haplotypes in relation to organ-specific autoantibody responses were studied in 82 Japanese patients with Type 1 (insulin-dependent) diabetes. HLA-DRw9 antigen and HLA phenotype of DRw9/X (X:not DR4) were increased in patients with organ-specific autoantibodies other than islet cell antibody (CP less than 0.02, RR = 4.02 and p less than 0.05 RR = 2.30, respectively); whereas HLA-DR4 antigen and HLA phenotype of DR4/X (X: not DRw9) were increased in those without the autoantibodies (CP less than 0.001, RR = 3.95 and p less than 0.01, RR = 2.46, respectively). HLA haplotype of Bw61-DRw9 was increased in patients with the autoantibodies (p less than 0.005, RR = 4.94), and HLA haplotype of Bw54-DR4 was increased in those without the autoantibodies (p less than 0.001, RR = 5.52). The relative risk of HLA-DR4/DRw9 was the highest among all HLA-DR phenotypes or genotypes in patients either with or without the autoantibodies. No association was, however, found between the incidence of islet cell antibody and HLA-DR phenotypes. These findings suggest that Type 1 diabetes among Japanese is immunogenetically heterogeneous as is Type 1 diabetes among Caucasians; and the differences in HLA-association of Type 1 diabetes among ethnic groups might give a clue to understanding of a role of HLA-antigens in the development of Type 1 diabetes.

Autoantibodies↗
PubMed1989

Strain differences of the light-dark preference in inbred rats.

The present study examined strain differences in the light-dark preference among four strains of rats. The test was done in the home-cage situation under 12L:12D cycles. Data from four strains were compared: BN/Kyo, BDIX/Nem, Wistar/Nu, and F344/NSlc. These strains differed in the light-dark preference measured by the ratio of the time spent in the field area of the home cage during the light period. BN/Kyo and BDIX/Nem spent the most time (approx. 23%) in the field during the light period, while F344/NSlc spent the least time (approx. 5%). Wistar/Nu fell between the two (approx. 12%).

Animals↗
PubMed1989

Mapping and nucleotide sequence of a new HLA class II light chain gene, DQB3.

A genomic clone specifying a new HLA class II antigen beta chain, DQB3, was isolated from a human genomic phage library using a DQB1 cDNA probe under low stringency conditions. Southern hybridization and nucleotide sequence analyses identified the beta 2 domain exon (exon 3) with several deleterious mutations and the CP-TM-CY exon [connecting peptide, transmembrane, and cytoplasmic regions, (exon 4)], but the first, second, and fifth exons encoding the 5' UT-leader, the beta 1 domain, and the 3' UT domain of normal beta chains, respectively, were entirely missing. The nucleotide sequences of these two exons were distinct from those of other class II beta chain genes, but slightly more related to the DQB1 and DQB2 genes than to other class II genes. The DQB3 sequence mapped between DQA2 and DQB1, 15 kb upstream from DQA2, by analysis of overlapping cosmid clones. This mapping was supported by the fact that Taq I, Msp I, and Bam HI DQB3 polymorphisms were perfectly correlated with the DQA2 polymorphism and not with any polymorphisms in the DR or DQ subregion, suggesting the presence of a hot spot for recombination between DQB3 and DQB1.

Amino Acid Sequence↗
PubMed1989

Feeding cycles entrain circadian rhythms of locomotor activity in CS mice but not in C57BL/6J mice.

The effects of periodic, restricted feeding (RF) for two hours at a fixed time of day on the circadian rhythms of locomotor activity were examined in CS and C57BL/6J mice, kept under continuous dim, red lights (LLdim). In C57BL/6J mice, free-running rhythms were not affected by an RF schedule, although anticipatory behavior prior to the food access period was observed. On the other hand, the free-running rhythms of CS mice did entrain to an RF schedule, exhibiting anticipatory behavior. The free-running rhythms of none of the control animals in either strain exhibited any effects resulting from the periodic disturbances occurring concurrently with the performance of RF. These results indicate that the circadian pacemaker couples with the food entrainable oscillator (FEO) in CS mice, but that such coupling may not exist, or may be very weak, in C57BL/6J mice.

Animals↗
PubMed1989

No difference in the nucleotide sequence of the DQ beta beta 1 domain between narcoleptic and healthy individuals with DR2,Dw2.

Narcolepsy is a sleep disorder completely associated with HLA-DR2,Dw2. We demonstrated the 100% presence of three DQ beta fragments (EcoRI 2.4-kb, BamHI 2.9-kb, and PstI 12-kb) in narcoleptic patients that were detected in healthy DR2 controls only at decreased frequencies. In this paper, we have cloned the DQ beta gene from three Japanese narcoleptic patients and sequenced their beta 1 domain in order to study the sequence polymorphisms that might exist in the DQ beta genes of patients, but no difference in sequence could be found between narcoleptic and healthy individuals, suggesting that narcolepsy is not due to mutation in the DQ beta gene. In this context, a possible role of the HLA class II antigens in narcolepsy is discussed.

Base Sequence↗
PubMed1989

HLA-D typing of heterozygotes using restriction fragment length polymorphism in the HLA-DQ gene region on the basis of standard band patterns derived from HLA homozygotes.

Genomic DNAs from 37 Epstein-Barr virus-transformed HLA-D homozygous cell lines with different Dw specificities, Dw1-Dw23, and DKT2 were digested with four different restriction endonucleases (EcoRI, PstI, TaqI, and MspI) and hybridized to DQ alpha and DQ beta cDNA probes. Polymorphic patterns of multiple fragments correlating with Dw, DQ, and DR haplotypes were detected, and the restriction fragment length polymorphism standard pattern specific for each Dw, DQ, and DR specificity could be defined. The polymorphic fragment patterns of HLA-D heterozygotes were predicted simply by the summation of two standard patterns of HLA-D homozygotes and utilized to identify HLA-D specificities of 25 normal individuals, who are HLA heterozygotes in most cases. The HLA-D, -DR, and -DQ specificities defined by this DNA typing were compared with those assigned by serologic and cellular typing. There was good correlation, allowing the application of accurate genotyping by DQ alpha and DQ beta cDNA probes to HLA class II typing of HLA heterozygotes.

Base Sequence↗
PubMed1989

High-affinity and selectivity of neosurugatoxin for the inhibition of 22Na influx via nicotinic receptor-ion channel in cultured bovine adrenal medullary cells: comparative study with histrionicotoxin.

In cultured bovine adrenal medullary cells, neosurugatoxin and histrionicotoxin inhibited carbachol-induced influx of 22Na, 45Ca and secretion of catecholamines with IC50 of 27 nM and 3 microM, respectively. The inhibitory effects of neosurugatoxin were reversed by the increased concentrations of carbachol, whereas those of histrionicotoxin were not. Histrionicotoxin at concentrations higher than 10 microM also reduced veratridine-induced influx of 22Na, 45Ca and secretion of catecholamines, while neosurugatoxin had no effects. High K-induced 45Ca influx and catecholamine secretion were not altered by either neosurugatoxin or histrionicotoxin. The present findings suggest (1) neosurugatoxin competitively inhibits nicotinic receptor-ion channel complex at nanomolar concentrations, but has no effects on voltage-dependent Na channel and voltage-dependent Ca channel; (2) histrionicotoxin at micromolar concentrations non-competitively suppresses nicotinic receptor-ion channel complex. Higher concentrations of histrionicotoxin also interferes with voltage-dependent Na channel, but has no effect on voltage-dependent Ca channel; (3) neosurugatoxin, due to its high-affinity and selectivity, may be a useful probe for studying nicotinic receptors in nervous tissues.

Adrenal Medulla↗