Biomedical subjects

S Mizuno

Publications and source records attributed to S Mizuno.

At least 397 records · Page 22Linked to original sources

PubMed1989

Purification and partial primary sequence of a chemotactic protein for polymorphonuclear leukocytes derived from human lung giant cell carcinoma LU65C cells.

A chemotactic protein for polymorphonuclear leukocytes (lung carcinoma-derived chemotaxin [LUCT]) was purified from culture fluid of the human lung giant cell carcinoma LU65C cells to electrophoretically homogeneous form through five sequential purification steps: DEAE-Sepharose, CM-Sepharose, HPLC on carboxyl-methylated-polyvinylalcohol resin, hydrophobic, and reversed-phase. The molecular mass was determined as approximately 10 kD by SDS-PAGE and isoelectric point was 10.7. The chemotactic activity (ED50 0.75 x 10(-9) M) was sevenfold more potent than that of FMLP (5 X 10(-9) M) and comparable with that of C5a (10(-9) M). NH2-terminal amino acid sequence and amino acid composition of LUCT strongly suggest that it may be closely related to the putative protein encoded by the cDNA clone (3-10C) and almost identical with a part of sequence of the chemotactic factor derived from stimulated human leukocytes in the 6th to 32nd, but not the NH2-terminal 5 amino acids. These results indicate that the carcinoma cells produce LUCT without any added stimulant and suggest that the previously isolated chemotactic monokines may correspond to des(1-5) of LUCT in the NH2-terminal region.

Amino Acid Sequence↗

PubMed1989

Nonhistone proteins HMG1 and HMG2 suppress the nucleosome assembly at physiological ionic strength.

The effect of nonhistone protein HMG1 and HMG2 from pig thymus on the in vitro nucleosome assembly has been examined with plasmid pSV2-gpt DNA and pig thymus core histones in the presence of DNA topoisomerase I. In the absence of core histones, the direct binding of HMG proteins could induce negative superhelical turns in DNA at low ionic strength, but not at physiological ionic strength. The nucleosome formation in the higher histone-to-DNA ratios at physiological ionic strength was not facilitated by HMG proteins, in contrast to poly(L-glutamic acid). HMG proteins suppressed the nucleosome assembly in the moderate histone-to-DNA ratios, resulting in the reduction of fully supercoiled DNA topoisomers. The suppression by HMG proteins was not cancelled by poly(L-glutamic acid). These suggest that the highly acidic carboxy terminal of HMG proteins does not act as an assembly factor, and that the HMG proteins, on the contrary, suppress the nucleosome formation, probably by binding to DNA in a way to inhibit the assembly into core particles.

Animals↗

PubMed1989

Mechanism of reversion of Rous sarcoma virus transformation by herbimycin A: reduction of total phosphotyrosine levels due to reduced kinase activity and increased turnover of p60v-src1.

We studied the mechanism of reversion of Rous sarcoma virus (RSV)-transformation by herbimycin A in a temperature-sensitive RSV-infected NRK cell line. Herbimycin reduced the total cellular phosphotyrosine level to 10% of the control value. Intracellular p60src kinase activity was reduced significantly within 3 h of herbimycin treatment, but recovered to approximately 50% of the control within 24 h, and the kinetics paralleled the decrease of the phosphorylation of a cellular target p36. Partial proteolytic phosphopeptide analysis of p60src revealed decreased phosphorylation of tyrosine 416 in the C-terminal half. Analysis of the steady state level of p60src indicated 30% decrease in src protein. Measurement of the rates of p60src synthesis and degradation showed that the decrease in the level was due to the accelerated degradation of src protein. Cycloheximide blocked this enhanced turnover of p60src, but did not block the herbimycin-induced inactivation of p60src kinase. Subcellular distribution and myristoylation of p60src protein were not altered. These results support the idea that RSV transformation is associated with elevated phosphotyrosine levels and indicate that inhibition of src kinase activity can reverse RSV-transformation by reducing cellular phosphotyrosine content.

Amino Acids↗

PubMed1989

Induction of erythroid differentiation of K562 human leukemic cells by herbimycin A, an inhibitor of tyrosine kinase activity.

Herbimycin A, a benzoquinonoid ansamycin antibiotic, is found to reduce intracellular phosphorylation by tyrosine protein kinase. The human chronic myelogenous leukemia cell line K562 expresses a structurally altered c-abl protein with tyrosine kinase activity. When K562 cells are induced to undergo erythroid differentiation by hemin, reduction in the intracellular level of tyrosine phosphorylation occurs. In order to understand the relationship between induction of differentiation and reduction of tyrosine phosphorylation by the c-abl gene product, the effect that herbimycin A, a selective inhibitor of intracellular tyrosine kinase activity, exerts on the differentiation of K562 cells was examined. Reduction of tyrosine phosphorylation in K562 cells by herbimycin A was observed within 1 h. Noncytotoxic concentrations of herbimycin A induced erythroid differentiation of K562 cells but not of murine erythroleukemia 745A cells. The other human myeloid leukemia cell lines (HL-60, THP-1, and U937) tested were not induced to undergo cell differentiation by this antibiotic. Herbimycin A and the other well-known inducers such as hemin, butyric acid, Adriamycin, and 1-beta-D-arabinofuranosylcytosine had additive or more than additive effects on induction of erythroid differentiation of K562 cells. With respect to inhibition of cell growth, the sensitivity of K562 cells to herbimycin A was highest in the human leukemia cell lines we tested. Noncytotoxic concentrations of herbimycin enhanced the antiproliferative effect of Adriamycin or 1-beta-D-arabinofuranosylcytosine on K562 cells. Combination therapy with herbimycin A and its derivatives may be considered for use in the treatment of some types of leukemia where tyrosine kinase activities are implicated as determinants of the oncogenic state.

Benzoquinones↗

PubMed1989

Presence of female-specific bent-repetitive DNA sequences in the genomes of turkey and pheasant and their interactions with W-protein of chicken.

Two female-specific repetitive DNA units, the 0.4 kb PstI and 0.5 kb TaqI sequences, were detected in the genomic DNA of turkey and pheasant, respectively, by Southern blot hybridization under non-stringent conditions with the W chromosome-specific 0.7 kb XhoI repetitive unit of chicken as a probe. Cloning and sequencing of these two repetitive units revealed that they shared features with the XhoI family repetitive unit of chicken although the overall similarities of the nucleotide sequences were less than 60%. In common with the chicken XhoI family they consisted of tandem repeats of about 21 bp, the majority of which contained (A)3-5 and (T)3-5 clusters separated by six or seven relatively G + C-rich sequences, and they behaved as bent DNA molecules on polyacrylamide gel electrophoresis at room temperature. W-protein, purified from chicken liver nuclei and shown to bind with high affinity to the XhoI family repetitive unit, also bound with the cloned repetitive units from turkey and pheasant DNase I footprint analysis suggested that the mode of interaction of W-protein with these units was similar to that with the 0.7 kb XhoI sequence. On the other hand, W-protein did not bind to the female-specific 0.4 kb BamHI repetitive unit from the Bobwhite quail. The 0.4 kb BamHI sequence contained some A and T clusters but these clusters did not appear in phase with the pitch of DNA helix and the repetitive unit did not show DNA bending.

Animals↗

PubMed1989

Isolation and expression of a cDNA clone encoding HLA-Cw6: unique characteristics of HLA-C encoded gene products.

The HLA-C encoded gene products display several characteristics which distinguish them from HLA-A and -B. The HLA-C antigens are poorly expressed on the cell surface, they display multiple proteins with different isoelectric points, and alloimmunization to HLA-C antigens is less common. To investigate whether the multiple products result from differential splicing of HLA-C gene transcripts, we have isolated a full-length cDNA clone encoding the Cw6 antigen. Class I antigens produced by the cDNA clone in transfected cells were of the same relative mass as those observed in the parental cells when analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Isoelectric focusing (IEF) gel analysis of the cDNA translated products in transfectants revealed multiple IEF bands. All IEF bands detected in the transfectants were also found in the parental cells, indicating that the multiplicity of the C-locus products was not due to differential splicing of HLA-C gene transcripts, but was probably due to post-translational modification. Comparison of the sequences of C-locus alleles with those of A and B alleles did not show any apparent sequences which would generate multiple IEF bands. Comparison of the coding regions for seven HLA-C alleles and one HLA-C-related class I gene with available data for 15 HLA-A and 20 HLA-B alleles demonstrated several unique features for the HLA-C locus. Six sites in the extra cellular domains, three in a1 and three in a3, were unique. While the cytoplasmic (CP) domain of HLA-A and -B are almost identical, the CP of HLA-C alleles is unique. Similar unique features of HLA-C are also observed in the transmembrane domain, resulting in locus-specific residues between positions 295 and 300. The present study has ruled out differential mRNA splicing as a mechanism for the multiplicity of Cw6 antigens and demonstrated unique HLA-C locus sequences.

Amino Acid Sequence↗

PubMed1989

Molecular mapping of a new public HLA class I epitope shared by all HLA-B and HLA-C antigens and defined by a monoclonal antibody.

It has previously been shown that a mouse monoclonal antibody, designated 4E, reacts with an epitope common to all HLA-B and -C antigens and those of the HLA-Aw19 cross-reactive group, namely, HLA-A29, -A30, -A31, -A32, -Aw33, and -Aw74. In order to pinpoint the amino acid residues which comprise the public specificity recognized by 4E, and HLA-A29 cDNA clone was isolated and its predicted amino acid sequence compared with those of other cloned HLA class I genes. The isolated HLA-A29 cDNA corresponded to the rarer of the two A29 variant alleles, A29.1. Two amino acid residues of HLA-A29.1, gln-144 and arg-151, were found in all 24 HLA-B and HLA-C alleles examined but were present in only one of 15 HLA-A alleles for which sequence data are available. Importantly, this exceptional allele was HLA-A32, another member of the HLA-Aw19 cross-reactive group. Gln-144 and arg-151 should be capable of jointly contributing to the binding site for 4E, as they are situated in successive alpha-helical subregions and are predicted to be juxtaposed in the three-dimensional HLA molecule. Four other residues in the first or second external domains of HLA-A29.1 (thr-9, leu-62, gln-63, and his-102) were unique among the HLA-A alleles, but none of these was found in corresponding positions of HLA-B of -C alleles and thus failed to correlate with presence or absence of the 4E determinant. These observations are consistent with the notion that gln-144 and arg-151 define a determinant common to HLA-B, HLA-C, and the HLA-Aw19 cross-reactive group and the binding site of the monoclonal antibody 4E.

Amino Acid Sequence↗

PubMed1989

Effect of ursodeoxycholic acid administration on nucleation time in human gallbladder bile.

The object of this study was to determine the effects of ursodeoxycholic acid administration on metastability in human gallbladder bile, as reflected by nucleation time. Bile samples from 10 patients with cholesterol gallstones who underwent preoperative ursodeoxycholic acid treatment exhibited a significantly longer median nucleation time (16 days) than those from 11 patients with cholesterol gallstones who received no preoperative treatment (4 days) (p less than 0.01). On the other hand, the median nucleation times of bile samples from 15 patients with noncholesterol gallstones and 24 patients without gallstones were 15 and 14 days, respectively. In addition, 3 mo of treatment with ursodeoxycholic acid significantly elevated the serum concentration of the antinucleating factor apolipoprotein A-I, from 133.3 +/- 12.3 to 148.6 +/- 13.2 mg/dl (p less than 0.05). These findings suggest that ursodeoxycholic acid retards cholesterol crystal nucleation, thereby inhibiting cholesterol gallstone formation. It is also possible that serum apolipoprotein A-I plays a role in this process.

Adult↗

PubMed1989

Phagocytosis and ingestion of influenza virus by human polymorphonuclear leucocytes in vitro: electronmicroscopy studies.

Interaction of human polymorphonuclear leucocytes (PMNL) and influenza virus (IFV) was studied in vitro. At 0 degree C, the viral particles were bound extensively to the surface of the PMNL membrane with a ratio of about 1000 virus particles to a single PMNL. The binding was sensitive to neuraminidase, suggesting attachment through sialo-compound receptors. At 37 degrees C, the virus particles disappeared rapidly from the cell surface, about half of them being eluted and the remainder being endocytosed into the cytoplasmic vesicles. Immuno-gold electronmicroscopy suggests that the virus particles are ingested into phagosomal vesicles and lysed.

Endocytosis↗

PubMed1989

Different correlations of drug susceptibilities to colonial morphology in Mycobacterium avium complex strains.

In Mycobacterium avium and Mycobacterium intracellulare complex strains isolated from patients who were not treated previously by any antituberculosis drugs or from fowls, the colonial morphology, smooth, domed, opaque (SmD) or smooth, flat, transparent (SmT) colonial forms, significantly correlated with susceptibilities to rifampicin, minocycline, streptomycin, kanamycin, enviomycin, ethambutol, and sulfadimethoxine, whereas it did not correlate with susceptibilities to isoniazid, cycloserine, and ethionamide. Strains with the SmT colonial morphology were more resistant to the former seven drugs than strains with the SmD colonial morphology. Since the susceptibilities to antituberculosis drugs with large molecules correlated with the colonial morphology, it has been suggested that a permeability barrier that allows passage of small molecules but prevents passage of large molecules exists in the strains with the SmT colonial morphology.

Anti-Bacterial Agents↗

PubMed1989

Lung cancer risk comparison among male smokers between the "six-prefecture cohort" in Japan and the British physicians' cohort.

We estimated the effective duration of cigarette smoking using the data of lung cancer mortality among male smokers of a large-scale cohort study in Japan and evaluated its role in the lung cancer risk difference between male smokers of the Japanese cohort and the British physicians' cohort. By selecting male cohort members who answered that they had started smoking at ages 18-22 (average = 20.3), the subjects of our analysis, which numbered 49,013, were made relatively homogeneous in terms of age at which smoking was started. Assuming lung cancer mortality to be proportional to the 4.5th power of the effective duration of cigarette smoking, i.e., (age-theta)4.5, as was proposed on the basis of the British cohort study by Doll and Peto, the parameter theta was estimated to be 29.4 for male smokers aged 40-64 in 1966; therefore, the estimated duration of cigarette smoking was, on average, 9.1 years (95% confidence interval = 5.8-11.6) shorter than that calculated from the reported age at which smoking was started. Our findings suggested that the low lung cancer mortality relative to daily cigarette consumption in Japan resulted from the shorter duration of cigarette smoking in the Japanese cohort, possibly due to the severe shortage of cigarettes during and shortly after World War II. Once the effective duration of cigarette smoking was adjusted, lung cancer mortality in the range of 5-34 cigarettes per day was fairly comparable to that observed among the cohort of male British physicians.

Adult↗

PubMed1989

Smoking and lung cancer mortality in Japanese men: estimates for dose and duration of cigarette smoking based on the Japan vital statistics data.

For the purpose of understanding human carcinogenesis and making a quantitative prediction of lung cancer mortality in a general population of Japanese males, we evaluated a statistical model which assumes lung cancer mortality to be proportional to the 4.5th power of the effective duration of cigarette smoking among smokers and to the 4th power of age among nonsmokers, using Japan Vital Statistics data. For the male birth cohorts aged 30-69 in 1965 in the age range of 40-79, studied by quinquennial calendar time intervals from 1955 to 1985, it was found that, (i) for nonsmokers, the estimated lung cancer mortality rate was comparable to the rates reported in the US or Britain, assigning 20 to 25% proportions of nonsmokers, (ii) for smokers, the estimated duration of smoking was shorter than would be expected from the age when smoking was started according to various epidemiological surveys, and (iii) the estimated average numbers of cigarettes smoked per day by smokers were similar to those obtained by epidemiological studies, when these were estimated by incorporating a part of Doll and Peto's dose-response relationship. Also discussed is the possibility of assessing lung cancer mortality risk for Japanese male smokers by means of the statistical model, alpha x (cigarettes smoked per day + beta) x (age - (age started smoking) - gamma)4.5.

Adult↗

PubMed1989

Chromosome analysis of canine transmissible sarcoma cells.

The chromosomal banding patterns of canine transmissible sarcoma (CTS) cells were analyzed and compared to those of normal canine cells with four banding techniques. In addition, N-myc and N-ras oncogenes on the chromosomes of the CTS cells were investigated by the in situ hybridization method. The modal chromosome number of the CTS cells was 58:17 metacentrics and 41 acrocentrics. Based on their G- and Q-banding patterns most of the chromosomes of the CTS cells were present in normal cells except for the second largest metacentric chromosomes. It was considered that the metacentric chromosomes of the CTS cells results from Robertsonian translocation of normal chromosomes. The long arm of the second largest metacentric element of the CTS cells was stained negatively by the Q-banding technique. The C-band was found on the long arm of the second largest metacentric element and three pairs of N-bands were recognized in the same region. It was suggested that this amplification of N-bands enhanced tumorigenic properties in the CTS. No N-myc or N-ras oncogenes were detected on chromosomes of the CTS cells by the in situ hybridization method.

Animals↗

PubMed1989

Multivariate evaluation of determinants affecting regional lymph node metastasis and survival in bladder cancer patients who underwent radical cystectomy.

To elucidate the relative importance of clinicopathologic factors affecting regional lymph node metastasis and survival in bladder cancer patients, multivariate analyses by the logistic regression model and proportional hazards model were performed for 86 patients who underwent radical cystectomy between 1978 and 1988. Clinicopathologic factors included in the analysis were sex, age, prior tumor history, time from onset of symptoms to cystectomy, and tumor characteristics (size, number, growth pattern, grade, stage, infiltration pattern, lymphatic invasion, lymphocytic infiltration around tumors, and lymph node metastasis). Nineteen of eighty-six patients (22%) had regional lymph node metastasis. Univariate analysis showed that lymph node metastasis was related to stage (p = 0.0006), lymphatic invasion (p = 0.006) and infiltration pattern (p = 0.02). Multivariate analysis revealed that stage is the only determinant of statistical significance for lymph node metastasis. High-stage tumors (pT3a-pT4) had 15 times higher risk for lymph node metastasis than low-stage tumors (pTis-pT2). The 5-year survival rates were 25 and 75% for patients with and without lymph node metastasis, respectively. Proportional hazards model revealed that stage is the most significant determinant (p = 0.0001) for survival, followed by lymph node metastasis with borderline significance (0.005 less than p less than 0.1). A two-factor model consisting of stage and lymph node metastasis yielded corrected hazard ratios of 14.7 for stage and 2.3 for lymph node metastasis. The present study quantitatively confirms previous univariate analyses of factors affecting lymph node metastasis and survival in patients undergoing radical cystectomy.

Adult↗

PubMed1989

The banding patterns of normal canine chromosomes.

The chromosomal banding patterns of canine normal chromosome were analyzed by G-, Q-, C- and N-banding techniques. The chromosomes of canine normal lymphocytes consisted of 38 acrocentric autosome pairs and X-, Y-metacentric sex chromosomes. Their G- and Q-banding patterns corresponded to the those reported by Manolache et al. in 1976. C-bands of chromosomes were found on the centromeric regions of the 7th, 26th, 34th, 35th, 37th and 38th pairs of chromosomes. In addition, N-bands whose location had not been confirmed until now were recognized on the telomitic regions of the 7th, 9th and 22nd pairs of chromosomes.

Animals↗

PubMed1989

Role of lymphocytes in dogs experimentally re-challenged with canine transmissible sarcoma.

The role of lymphocytes in dogs re-challenged with canine transmissible sarcoma (CTS) was investigated histologically and immunologically. Tumors were detected on the 3rd day, began to regress on the 9th day and disappeared on approximately the 15th day after the secondary transplantation (AST). The CTS cells were surrounded by lymphocytes which had infiltrated from the early stage, degenerated and ultimately disappeared. Most of the lymphocytes expressed thymocyte antigen (Ta) on the cell membrane surface. The numbers of lymphocytes and Ta-positive lymphocytes in peripheral blood increased gradually AST. The blastogenic responses of peripheral blood lymphocytes (PBL) induced by 3 kinds of mitogens were elevated strikingly from the early stage AST. These results suggest that Ta-positive lymphocytes play an important role in vivo in the regression of tumors and that the immunological activity of PBL is stimulated immediately AST.

Animals↗

PubMed1989

Determination of the sex of chickens by a biotin-labeled deoxyribonucleic acid probe.

Repeating units of the W chromosome-specific, XhoI-family repetitive DNA of chickens have been cloned and sequenced. The recombinant plasmid carrying the .7 kilobase (kb) W chromosome-specific repeating unit was labeled by biotinylated deoxyuridine 5'-triphosphate and used to determine the sex of White Leghorn chicken by two DNA hybridization techniques. Hybrids formed were detected by the streptavidin-alkaline phosphatase method. By Southern blot hybridization, XhoI-.7 kb, XhoI-1.1 kb, and EcoRI-1.3 kb fragments were detected in the genomic DNA from the female White Leghorn but not in the DNA from the male. By dot-blot hybridization, which is the most convenient way to detect a specific nucleotide sequence, the difference between male and female could be clearly detected not only using purified DNA samples but also using blood cells or even blood itself as samples.

Animals↗

PubMed1989

[The study on factors affecting cholesterol solubility in bile: relation to biliary proteins including apolipoprotein A-1].

We studied the preferential distribution patterns of cholesterol and proteins to biliary lipid particles isolated from human gallbladder bile by gel permeation chromatography. In addition nucleation times of those bile samples were determined to estimate the metastability of bile cholesterol. Cholesterol dominantly incorporated into a non-micellar fraction in bile from cholesterol gallstone patients with and without preoperative treatment with ursodeoxycholic acid, whereas nucleation time was significantly longer in cholesterol gallstone patients with a preoperative treatment with ursodeoxycholic acid than that of those without any preoperative treatment (p less than 0.01). Furthermore the induced incorporation of apolipoprotein A-1 into a non-micellar fraction was found in bile from cholesterol gallstone patients with ursodeoxycholic acid. These results suggest that stabilizing effects of apolipoprotein A-1 on a non-micellar fraction has been induced by ursodeoxycholic acid treatment resulting in the retardation of cholesterol nucleation in bile.

Apolipoprotein A-I↗