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Biomedical subjects

S Oka

Publications and source records attributed to S Oka.

At least 379 records · Page 21Linked to original sources
PubMed1989

Effects of okadaic acid on mouse hemopoietic cells.

Effects of okadaic acid, a potent non-12-O-tetradecanoyl-phorbol-13-acetate(TPA)-type tumor promoter, on mouse hemopoietic cells were investigated. Okadaic acid stimulated mouse bone marrow cells to form granulocyte-macrophage colony-forming unit (CFU-GM) colonies without added colony stimulating factors(CSFs). At the concentration of 1.82 x 10(-8) M, colony formation of 77 +/- 14 colonies/1 x 10(5) bone marrow cells was observed. Observations on the effects of other cells on the CSF induction suggested that okadaic acid primarily stimulated the functions of macrophages, and the CSF production from macrophages might be attributed to the CFU-GM colony formation. On the other hand, the erythroid colony-forming unit(CFU-E) colony formation stimulated by

Animals↗
PubMed1989

Sugar sequences of allergenically active oligosaccharide alcohols isolated from a large-molecular-size sea squirt antigen termed H-antigen.

O-Glycosidically linked oligosaccharide chains were liberated as oligosaccharide alcohols (HPG-beta 2) by beta-elimination treatment from a glycopeptide fraction (HPG, Mr ca. 10(5)) that was isolated from a Pronase digest of a large-size sea squirt antigen termed H-antigen (Mr 10(6)-2 X 10(7)). After HPG-beta 2 was divided into a neutral (HPG-beta 2-N) and an acidic (HPG-beta 2-A) fraction, 11 neutral saccharitols were isolated from HPG-beta 2-N, and their sugar sequences were determined by methylation/GC-MS, FAB-MS, and/or DI/EI-MS. By skin tests specific to patients with sea squirt allergy, it was found that six saccharitols were allergenically active but five were inactive. Furthermore, active saccharitols were all of branched structure containing two nonreducing terminal GalNAc (t-GalNAc) residues, whereas the inactive saccharitols contained one or no t-GalNAc. Since the allergic reaction in skin should depend on the crosslinking of IgE antibodies by certain allergens carrying two or more epitopes, three types of N-acetylgalactosaminyl disaccharide units, GalNAc1----2Fuc1----, GalNAc1----3/4GalNAc1----, and GalNAc1----3/4GlcNAc1----, were nominated as the major components of the allergy-specific epitopes in the active saccharitols. Such multiplicity of the epitope structures might reflect the polyclonality of the specific IgE antibodies.

Allergens↗
PubMed1989

Purification of erythropoiesis-stimulating activity (ESA) from one Actinomycetes strain.

An Actinomycetes strain was found to produce a protein which stimulated the growth of murine erythroid progenitors in vitro. The protein was purified to homogeneity and was named Erythropoiesis-Stimulating Activity (ESA). ESA was an acidic glycoprotein with a molecular weight around 80,000. When mouse bone marrow cells were cultured in methylcellulose medium containing physiological concentrations of erythropoietin (0.048 units/ml), addition of ESA stimulated the growth of colony forming unit-erythroid (CFU-E) up to three-fold a in dose dependent manner. ESA was not active on the other hematopoietic progenitors.

Actinomycetaceae↗
PubMed1989

E-series prostaglandins activate cAMP-mediated potassium currents in follicle-enclosed Xenopus oocyte.

Receptor-mediated responses to prostaglandins E1 and E2 are shown by electrophysiological methods in follicle-enclosed oocytes of Xenopus laevis. In voltage-clamped oocytes, prostaglandins E1 and E2 elicited an outward hyperpolarizing current. This outward membrane current was caused by an increase in K+ conductance. The prostaglandin-induced current was augmented by adenylate cyclase activator, forskolin, and by phosphodiesterase inhibitor, theophylline, indicating that adenosine 3', 5'-cyclic monophosphate (cAMP) is involved in activating the K+ current. The prostaglandin responses were either abolished or greatly reduced by removing follicular cells with collagenase, suggesting that prostaglandin receptors reside in the follicular cells.

Acetylcholine↗
PubMed1989

Changes in chromatin structure of boar late spermatids to mature spermatozoa by using modification with dansyl chloride.

Changes in the chromatin structure of boar late spermatids maturing to spermatozoa were studied by chemical modification of their nuclei with dansyl (Dns) chloride. Protamine was isolated from the dansylated boar spermatid and sperm nuclei, and its dansylated sites and degrees of dansylation were determined by sequence analysis. The N-terminal Ala-1, Tyr-3 and Tyr-42 of the protamine molecule in cauda epididymal sperm nuclei were dansylated 27%, 22% and 40%, respectively, whereas the respective residues in late spermatid nuclei were about 1.5-times as reactive as those in cauda epididymal sperm nuclei. However, the dansyl ratio of Tyr-3 to Tyr-42 remained unchanged from the late spermatid to mature sperm nuclei. SDS treatment did not affect the reactivity of cauda epididymal protamine and that of Ala-1 of caput epididymal protamine, but raised that of Tyr-3 and Tyr-42 of caput epididymal protamine by a factor of about 1.5. As a result of the SDS treatment, caput epididymal protamine came to have almost the same reactivity as late spermatid protamine. These facts suggest that the fundamental structure, in terms of DNA-protamine interaction, of sperm chromatin was already formed at the stage of the late spermatid, and then during epididymal transit the sperm chromatin was more tightly condensed, with increasing disulfide cross-links, thereby acquiring insensitivity towards the SDS-treatment.

Amino Acid Sequence↗
PubMed1989

Human serum immuno-reactive copper, zinc-superoxide dismutase assayed with an enzyme monoclonal immunosorbent in patients with digestive cancer.

Two types of monoclonal antibodies, N4 and N6, were raised against human copper, zinc-superoxide dismutase (Cu,Zn-SOD). An enzyme-linked immunosorbent assay for Cu,Zn-SOD was developed in sandwich method using these monoclonal antibodies. The measurable assay range was 1.0-100 micrograms/l and the coefficient of variation within and between series were 7.5% and 8.1%. Sera of 154 healthy control subjects displayed a low level (14 micrograms/l) of immunoreactive Cu,Zn-SOD with a logarithmic normal distribution. On the other hand, serum Cu,Zn-SOD levels were significantly elevated in patients with various digestive cancers.

Antibodies, Monoclonal↗
PubMed1989

Human breast carcinoma (ZR-75-1) serially transplanted into nude mice--with reference to estradiol dependency and sensitivity to tamoxifen.

Tumor cells of the ZR-75-1 line (1 X 10(7) in 0.5 ml) were inoculated into the right thigh muscles of BALB/c female nude mice which were, at the same time given 1.0 mg of estradiol subcutaneously. After the transferable strain had been established, the tumors were then transplanted into female and male nude mice either with or without estradiol treatment. Although no exponential tumor growth was observed in the untreated male and female nude mice, no complete rejection was found during the experiments. The estrogen receptor of this strain was positive and the growth of ZR-75-1 was dependent on exogenous estradiol. ZR-75-1 in the nude mouse was insensitive to tamoxifen treatment, given as 5 mg/kg intramuscularly twice a week, suggesting that dependency on estradiol is not necessarily correlated with endocrine sensitivity to tamoxifen.

Animals↗
PubMed1989

Clinical evaluation for the mechanism of cisplatin with bromodeoxyuridine by flow cytometry and clinico-histological study.

The tumor cell kinetics before and after intra-arterial injection of cisplatin (CDDP) was examined in a patient with maxillary carcinoma using flow cytometry and propidium iodide and fluorescein isothiocyanate labeled bromodeoxyuridine double staining. In addition, the viability was determined with fluorescein diacetate and compared with the histological picture. The action mechanism which the authors obtained 24 hours after intra-arterial injection of CDDP to the clinical case was considered to be S phase block, especially early S phase block. Markedly decreased viability also makes us consider the cytocidal effect. These findings correlated with the data of the fundamental investigation reported previously. Histological examination after the intra-arterial injection of CDDP revealed remarkable necrosis in the tissue.

Bromodeoxyuridine↗
PubMed1989

Therapeutic effect and titers of the specific IgE and IgG antibodies in patients with sea squirt allergy (Hoya asthma) under a long-term hyposensitization with three sea squirt antigens.

Hyposensitization therapy with each of three sea squirt antigens, Gi-rep (molecular weight [MW] 106,000), Ei-M (MW 22,800), and DIIIa (MW 9980), have succeeded in 72%, 90%, and 36% of patients with sea squirt allergy, respectively, within the first year, and the effect has been maintained during subsequent 4-year maintenance therapy. All available sera from some of the hyposensitized patients were also examined for IgE and IgG titers against the most effective therapeutic antigen, Ei-M, and it was revealed that the Ei-M-specific IgG titer increased rapidly in the successfully hyposensitized patients, regardless of the therapeutic antigen used, except for a few patients. Furthermore, the high specific IgG titer, as well as the therapeutic effect, was maintained during the subsequent maintenance therapy. No such increase in the specific IgG titer was detected in all unsuccessfully hyposensitized patients. In contrast, the Ei-M-specific IgE titer was practically unchanged in all allergic patients, independent of the therapy. Therefore, the effect of the hyposensitization therapy was closely dependent on the induction of the specific IgG capable of competing with the specific IgE for a certain asthma-inducing antigen, like DIIIa. The apparently low therapeutic efficiency of DIIIa was attributed to its relatively low immunogenicity to induce the specific IgG.

Allergens↗
PubMed1989

Profiles of enterotoxin and cytotoxin production in Campylobacter jejuni and C. coli.

Enterotoxin and cytotoxin production of 10 strains of Campylobacter spp. were examined by ELISA and HeLa cells assay, respectively. Both toxins were produced in high concentrations by strains freshly isolated from patients. The maximum enterotoxin activity was found to be at 24 h after incubation, at which time cell growth reached the stationary phase. On the other hand, production of cytotoxin increased after the logarithmic phase of the growth.

Campylobacter↗
PubMed1989

N-acetylgalactosaminyl disaccharide terminals contained in presumed carbohydrate epitopes specific to sea-squirt allergy.

Using the methods of methylation/GLC, MS, and 1H-NMR analyses, a disaccharide structure of GalNAc alpha 1----2Fuc1---- was identified as one of the major structural units at non-reducing terminals of a highly branched and N-glycosidically linked carbohydrate on an allergenically active glycopeptide, Gp-2 (Mr ca. 8,000). Gp-2 was one of the major fractions in the Pronase digest of a sea-squirt antigen, Gi-rep, and is capable of eliciting the skin reaction specific to patients with sea-squirt allergy similarly to Gi-rep. An additional disaccharide structure of GalNAc1----(3/4)HexNAc1---- was also expected as the other major non-reducing terminal unit, though the anomeric configuration of the terminal GalNAc could not be identified. As Gp-2 carbohydrate was found to contain 3 mol each of the two types of terminal GalNAc-containing units, both were nominated as possible components of the IO4- oxidation-sensitive epitopes which are responsible for the allergenic activity in Gp-2 and its mother antigen, Gi-rep. A few moles of Fuc and Gal were also detected as minor non-reducing terminals in addition to the 6 mol of the GalNAc-containing units.

Acetylglucosamine↗
PubMed1989

Rapid identification of serotypes of Mycobacterium avium-M. intracellulare complex by using infected swine sera and reference antigenic glycolipids.

The species of 136 strains of acid-fast bacteria isolated from swine with mycobacteriosis were identified by numerical taxonomy and chemotaxonomy on the basis of mycolic acid subclass composition as members of the Mycobacterium avium-M. intracellulare (MAI) complex. The isolates were further classified by using both thin-layer chromatography of the antigenic glycopeptidolipids (GPL) obtained from the bacteria by the method of Tsang et al. (A. Y. Tsang, I. Drupa, M. Goldberg, J. K. McClatchy, and P. J. Brennan, Int. J. Syst. Bacteriol. 33:285-292, 1983) and the seroagglutination test devised by W. B. Schaefer (Am. Rev. Respir. Dis. 92[Suppl.]:85-93, 1965). For the reference standard, purified antigenic GPL of serotypes 4, 8, and 9 were isolated and their structures were analyzed by negative fast-atom bombardment-mass spectrometry. The fast-atom bombardment-mass spectrometric spectra of the intact GPL antigens of serotypes 4, 8, and 9 agreed with the structures reported earlier by Brennan et al. (P. J. Brennan and M. B. Goren, J. Biol. Chem. 254:4205-4211, 1979; P. J. Brennan, G. O. Aspinall, and J. E. Nam Shin, J. Biol. Chem. 256:6817-6822, 1981). With these antigenic GPL, the thin-layer chromatographic behaviors of the alkali-stable lipids of the above-described isolates were examined. These MAI complex isolates fell into the serotype 8 (85 strains), 4 (33 strains), and 9 (7 strains) and untypeable (11 strains) categories. Furthermore, an enzyme-linked immunosorbent assay (ELISA) based on type-specific glycolipid antigens and infected swine sera was used to diagnose the serological types of the MAI complex isolates. Of 14 cases typed by both the seroagglutination reaction and thin-layer chromatography, 13 showed clear agreement with the ELISA results. The results demonstrated that ELISA using infected sera was especially useful, and it can be recommended on the basis of simplicity, sensitivity, and specificity as an adjunct to the seroaggulutination test and thin-layer chromatography for identification of mycobacteria belonging to the MAI complex.

Agglutination Tests↗
PubMed1989

[Granuloma formation in mice by liposomes of new glycolipid containing mycolic acids, "trehalose 2,3,6'-trimycolate"].

After intravenous administration of liposomes containing a novel glycolipid, trehalose 2,3,6'-trimycolate, isolated from Rhodococcus aurantiacus, the granuloma formation was observed distinctively in the lungs, spleen and liver of ICR mice. The concentration of the glycolipid in liposomes influenced profoundly on the inducibility for granulomas and the liposomes containing 10 mol% of trehalose 2,3,6'-trimycolate showed the highest activity for the granuloma formation in mice without a significant loss of body weight of mice with a less toxicity. EggPC liposomes are of more highly inducible for the granuloma formation in mice than eggPC:PS (7:3, mol ratio) liposomes or eggPC:Chol (9:1, mol ratio) liposomes, suggesting that cholesterol in liposomes was not necessarily essential for inducing granulomas in mice. Among the various PC liposomes, synthetic dimyristoyl-phosphatidylcholine (DMPC) or dipalmitoylphosphatidylcholine (DPPC) liposomes were of highly inducible, although a high responsiveness was also observed with natural lecithines such as egg or soy PC. However, distearoylphosphatidylcholine (DSPC) liposomes did not show any activity for the granuloma formation in any organs of mice. Organ responsiveness differed significantly in the micelle forms injected. Glycolipid entrapped with eggPC-Chol liposomes showed a lower lung index below 1.0, in contrast to w/o/w micelles containing Freunds' incomplete adjuvant, which showed a higher granuloma formation in the lungs. It was also noted that the toxicity of glycolipid containing liposomes was comparatively lower than the toxicity of glycolipid containing w/o/w micelles, indicating that the liposomes appeared to be more suitable for the induction of the immunomodifying activities of mycolic acid-containing glycolipids than w/o/w micelles.

Animals↗
PubMed1989

[Analysing noise levels in dental environment. Air turbine sound response to various physical factors].

Dental Air Turbine sound depends on the mechanical performance such as rotation and it is impossible to neglect connections of the sound with fluid mechanics and acoustics. Turbine sound must be considered from the standpoint of the sound pressure level and frequency component. In this study, the sound samples was measured and analysed in octave band spectrum. Turbine sound has three resonance bands of the frequency with the range from 0 to 1,600 Hz and the resonance band increased as air pressure increased. The frequency of the second resonance band decreased as the cutting load and cutting point diameter increased. Damping of the second resonance band frequency shifted downward by polishing point.

Dental High-Speed Equipment↗
PubMed1989

Beta-interferon and early stage HIV infection.

beta-Interferon (IFN-beta) was evaluated prospectively for its antiviral activities in early stage human immunodeficiency virus (HIV) infection. Ten patients with hemophilia and HIV infection [8 asymptomatic carriers (AC) and 2 AIDS-related complex (ARC)] were intravenously injected with 1 million IU of IFN-beta twice a week for 6 months. For comparison, seven patients (six AC and one ARC) with hemophilia and HIV infection were observed for the same time period without any drugs. One episode of localized herpes zoster each occurred during the trial in the IFN group and in the control group. There were no significant differences in the absolute number of CD4+ lymphocytes and ratios of CD4+/CD8+ lymphocytes between the two groups. Recipients had flu-like symptoms but no serious toxicities. No clinical and immunological benefits to patients with early stage HIV infection were observed during the 6 months of treatment.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Relationships between structure and biological activity of the mycolic acid-containing glycolipids from Nocardia asteroides "sensu stricto" and related species.

To reveal the taxonomical situation of Nocardia asteroides "sensu stricto", we compared the mycolic acid and mycolic acid-containing glycolipid composition and their granulomagenic activities in mice. The major glycolipids were glucose mono- and dimycolate, trehalose mono- and dimycolate and several unknown glycolipids, commonly, although the relative amount differed from strain to strains. On the other hand, molecular species composition of mycolic acids differed distinctively among the three closely related species: N. asteroides "sensu strico", N. farcinica and N. nova. GC/MS analysis showed the most abundant species of mycolic acids were C50(52) in N. asteroides, C54(52) in N. farcinica and C58(56) in N. nova, respectively with a different alpha-alkyl branch. Glucose mycolate and trehalose dimycolate possessing C50 mycolic acid showed a strong activity for granuloma formation in mice.

Animals↗