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S Oka

Publications and source records attributed to S Oka.

At least 361 records · Page 20Linked to original sources
PubMed1990

Quantitative analysis of human immunodeficiency virus type-1 DNA in asymptomatic carriers using the polymerase chain reaction.

A method for detecting human immunodeficiency virus type 1 (HIV-1) provirus DNA in lymphocytes with improved sensitivity and reproducibility was developed using the polymerase chain reaction (PCR). Amplified HIV-1 DNA was hybridized with a 32P-labeled probe and quantitated with a beta-scanner after electrophoresis. A linear relationship was obtained between the common logarithms of the counts detected and the number of HIV-1 DNA copies applied to the PCR. Detectability was from 3 copies/10(5) lymphocytes, and linearity was maintained from 10 to 10(3) copies. HIV-1 DNA was detected in all 9 asymptomatic carriers tested (18 to 2,857 copies/10(5) CD4+ T lymphocytes). The viral burden was inversely related to the CD4+ lymphocyte count, suggesting that quantitation of provirus levels may serve as a predictor of progress in early HIV infection.

Autoradiography↗
PubMed1990

Mycolyl glycolipids stimulate macrophages to release a chemotactic factor.

We have previously reported that mycolyl glycolipids from Nocardia rubra such as glucose or trehalose mycolates induced granuloma formation in mice. The structure of the carbohydrate moiety of the mycolyl glycolipids influenced the granuloma forming activity profoundly. Here, we have examined the macrophage-chemotactic activity in the culture supernatants stimulated with various glycolipids differing in carbohydrate moiety (trehalose 6,6'-dimycolate, or TDM; glucose monomycolate, or GM; mannose monomycolate, or MM; and fructose monomycolate, or FM). A distinctive chemotactic activity was detected with TDM or GM, but, little or none with MM or FM.

Animals↗
PubMed1990

A new combined trivalent live measles (AIK-C strain), mumps (Hoshino strain), and rubella (Takahashi strain) vaccine. Findings in clinical and laboratory studies.

Trivalent virus vaccine, containing measles AIK-C strain, mumps Hoshino strain, and rubella Takahashi strain, was administered to a total of 1369 healthy children, 8 months to 18 years of age. For comparative study, monovalent vaccines of AIK-C strain and Hoshino strain were administered to 147 and 122 initially seronegative children, respectively. The clinical and serological responses following vaccination were analyzed. Among the recipients of the trivalent vaccine, 893 were initially seronegative to all three viruses. Inoculation induced sufficient serological responses: 99.7% for measles and rubella viruses and 96.3% for mumps virus. The incidence of febrile reaction (greater than or equal to 37.5 degrees C axillary temperature) was low, 15.9%, and a temperature of 39.0 degrees C or higher occurred in only 1.3% of the subjects. The seroconversion rate, magnitude of antibody titers, and incidence of clinical reactions following the trivalent vaccination were similar to those occurring after the monovalent measles vaccination.

Adolescent↗
PubMed1990

Parallel antitumor, granuloma-forming and tumor-necrosis-factor-priming activities of mycoloyl glycolipids from Nocardia rubra that differ in carbohydrate moiety: structure-activity relationships.

Multiple intravenous injections (30 micrograms, ten times) in ICR mice of trehalose dimycolate and glucose monomycolate from Nocardia rubra, containing C36-48 mycolic acids, showed a prominent antitumor effect on a subcutaneously implanted sarcoma-180, an allogeneic sarcoma of mice with a significant granuloma formation in lungs, spleen and liver. On the other hand, mycoloyl glycolipids other than glucose monomycolate and trehalose dimycolate, such as mannose or fructose mycolate, showed no significant activity for tumor regression or granuloma formation in mice. Trehalose dimycolate and glucose monomycolate from N. rubra, and glucose monomycolate with C56-60 mycolic acids from Rhodococcus terrae also showed a distinctive priming activity for tumor necrosis factor (TNF), when lipopolysaccharide from Escherichia coli was administered as an eliciting agent. The TNF activity in the sera of mice was abrogated almost completely by anti-(murine TNF alpha) antibody with protein-A-agarose. Again in contrast, mannose and fructose mycolate from N. rubra and glucose monomycolate with C30-34 mycolic acids from Rhodococcus equi did not show such activities in mice. Meth-A, a syngeneic fibrosarcoma of BALB/c mice, was less sensitive to administration of glycolipids than sarcoma-180. These results indicated that the existence of a glucose or trehalose molecule was necessary for the expression of immunomodifying activities among various mycoloyl glycolipids differing in carbohydrate structure. However, since the administration of lipopolysaccharide was essentially required as an eliciting agent for the induction of TNF, while no eliciting agent was required for the antitumor activities, TNF does not seem to contribute directly to the antitumor activities of mycoloyl glycolipids in our systems. There was, however, a parallel structure-activity relationship among granuloma-forming, antitumor and TNF-priming activities, indicating that the structures of both the carbohydrate moiety and the mycoloyl residues influenced an initial step, such as macrophage activation, commonly and profoundly.

Animals↗
PubMed1990

Mammalian telencephalic neurons express a segment-specific membrane glycoprotein, telencephalin.

Using affinity chromatography with the monoclonal antibody 271A6, which binds selectively to telencephalic regions of the rabbit brain, we have purified a telencephalon-specific antigen to apparent homogeneity and characterized it as a membrane glycoprotein. The telencephalon-specific membrane protein (named "telencephalin") has a molecular weight of about 500,000 and is composed of four subunits each of mol. wt 130,000. Its digestion with N-glycanase reduced the subunit mol. wt by 23,000, indicating that each subunit has several N-asparagine-linked oligosaccharide chains. Immunohistochemical analysis using polyclonal antibody against the purified telencephalin shows that expression of the entire protein is restricted to the telencephalon. In addition, segment-specific expression of telencephalin was observed in all mammalian species examined (mouse, rat, guinea-pig, rabbit, cat and monkey). The telencephalon is the most rostral segment of the brain, and comprises the cerebral neocortex, paleocortex, hippocampus, septum, striatum and olfactory bulb. The present results indicate that all regions of the mammalian telencephalon express the segment-specific membrane glycoprotein, telencephalin, and suggest that telecephalin is involved in functions specific to the surface membrane of telencephalic neurons.

Animals↗
PubMed1990

Structure of an allergenic pentasaccharitol, Gp-1 beta-b6, isolated from a sea squirt antigen, Gi-rep, as a minimum structural unit responsible for its allergenicity.

An allergenic pentasaccharitol, Gp-1 beta-b6, was isolated as a minimum structural unit responsible for the allergic reaction in skin of patients with sea squirt allergy from a saccharitol fraction, Gp-1 beta-b, that had been liberated by beta-elimination from a glycopeptide in a Pronase digest of a sea squirt antigen, Gi-rep. Methylation/GC-MS and FAB-MS analyses indicated the sugar sequence of Gp-1 beta-b6 to be GalNAcl----2Fucl----(GalNAc1----) 3,4GlcNAc1----3GalNAc-ol. To analyze the structure in more detail, Gp-1 beta-b6 was labeled with p-aminobenzoic acid ethyl ester (ABEE), i.e., the reducing terminal 3-O-substituted GalNAc-ol of the saccharitol was oxidized to 2-O-substituted L-ThrNAc with equimolar periodate, and the resultant aldehyde was labeled with ABEE by reductive amination. The ABEE-labeled Gp-1 beta-b6 was subjected to sequential exoglycosidase digestion with beta-N-acetylhexosaminidase, alpha-N-acetylgalactosaminidase, and alpha-fucosidase, and the digests were chromatographed on an HPLC column of TSK gel Amide 80. From the results of the HPLC, methylation/GC-MS, and FAB-MS analyses of the digests of the labeled substrate, the structure of Gp-1 beta-b6 was determined to be GalNAc alpha 1----2Fuc alpha 1----3(GalNAc beta 1----4)GlcNAc beta 1----3GalNAc-ol. Enzymatic elimination of either the non-reducing terminal beta-GalNAc or the non-reducing terminal alpha-GalNAc led to inactivation of the allergenic pentasaccharitol. Accordingly, it is possible that the allergenic saccharitol contains two disaccharide units as the allergy-specific epitopes, one GalNAc alpha 1----2Fuc alpha 1---- and the other GlcNAc beta 1----4GLcNAc beta 1----.

Allergens↗
PubMed1990

Granuloma-forming activity and antitumor activity of newly isolated mycoloyl glycolipid from Rhodococcus terrae 70012 (Rt. GM-2).

A newly isolated mycoloyl glycolipid (Rt. GM-2) from Rhodococcus terrae 70012 was identified and the granulomagenic and antitumor activities were studied as compared with trehalose-6,6'-dimycolate (cord factor) also from R. terrae (Rt. TDM). The alkaline hydrolysis products of Rt. GM-2 contained trehalose, methyl-alpha-mycolate and a less-polar ester than the usual methyl-alpha-mycolate, possibly beta-keto mycolate (1:1:1, by mol. ratios). On the other hand, analysis of alditol acetate obtained after the mild permethylation, NaBH4 reduction, and acetylation showed the occurrence of 2,3,4-tri-O-methyl-6-O-acetylglucitol. Therefore, the original glycolipid (Rt. GM-2) was identified tentatively as 6-O-alpha-mycoloyl 6'-O-beta-ketomycoloyl trehalose. Intravenous injection of Rt. GM-2 in the form of water-in-oil-in-water emulsion caused prominent granulomas in lungs and spleen of ICR and BALB/c mice. The granulomagenic effects were as strong as those caused by Rt. TDM. The lung and spleen weights reached peaks one week after an injection of Rt. GM-2 in mice and then gradually decreased. Multiple intravenous injections of Rt. GM-2 and Rt. TDM showed antitumor activity against subcutaneously implanted Sarcoma-180, and caused prominent granulomatous changes and growth suppression of mice.

Adjuvants, Immunologic↗
PubMed1990

Induction of interferons (IFNs) and tumor necrosis factor (TNF) in mice by a novel glycolipid trehalose 2,3,6'-trimycolate from Rhodococcus aurantiacus (Gordona aurantiaca).

The immunomodifying activity of a novel mycoloyl glycolipid, trehalose 2,3,6'-trimycolate (GaGM), from a unique psychrophilic acid-fast bacterium, Rhodococcus aurantiacus, was examined. ICR mice were primed intravenously (i.v.) or intraperitoneally (i.p.) with liposomes containing GaGM (300 micrograms/mouse), and were administered LPS dissolved in saline (25 micrograms/mouse, i.v.) 2 weeks later. Two hours after injection of LPS, interferons (IFNs) and tumor necrosis factor (TNF) were induced significantly in mice sera. The increase in activities of IFNs and TNF was approximately paralleled with granuloma formation in spleen of mice primed with GaGM. However, IFNs and TNF were not induced either in mice primed with GaGM but not elicited with LPS, or in those primed with GaGM and elicited by GaGM. Both activities induced were lower in mice primed with trehalose mono- or dimycolate from R. aurantiacus (GaTMM, GaTDM) or TDM from Nocardia rubra than in GaGM-primed mice. Time course study showed that the maximum activity of each interferon (alpha, beta, or gamma) was observed at different stages after LPS administration; IFN-alpha, IFN-beta, and IFN-gamma appeared 3, 2, and 6 hours most abundantly after LPS administration, respectively.

Animals↗
PubMed1990

An immunohistochemical study of copper, zinc-containing superoxide dismutase detected by a monoclonal antibody gastric mucosa and gastric cancer.

The immunohistochemical localization of copper, zinc-superoxide dismutase (Cu,Zn-SOD) in human gastric mucosa and gastric cancer was studied using a monoclonal antibody. In gastric mucosa, parietal cells, pyloric glandular cells and foci of intestinal metaplasia showed positive staining in the cytoplasm and/or nucleus. The wide distribution of Cu, Zn-SOD in the gastric mucosa suggests cell function may be vulnerable to active oxygen species. In gastric cancer, 34 of 70 cases showed a positive reaction for Cu, Zn-SOD. There was a relationship between the grade of Cu,Zn-SOD immunoreactivity and the histological type of gastric cancer, well-differentiated types of gastric cancer being more frequently positive. The positive cases of poorly-differentiated adenocarcinoma were characterized by a pattern of diffusely infiltrative invasion. These results suggest that some types of gastric cancer are resistant to active oxygen species.

Adenocarcinoma↗
PubMed1990

Mechanism of diethyldithiocarbamate-induced gastric ulcer formation in the rat.

Diethyldithiocarbamate (DDC) was injected subcutaneously in the rat and the mechanism of gastric ulcer formation was investigated. DDC induced gastric ulcers in a dose-dependent manner. DDC significantly suppressed gastric mucosal copper-zinc superoxide dismutase (Cu, Zn-SOD) activity at 2 hr. However, manganese-superoxide dismutase (Mn-SOD) activity was not changed. Gastric mucosal blood flow (GMBF) decreased to 52% of the control level at 2 hr after administration of DDC and gradually increased to reach the control level by 7 hr. A Shay rat preparation (4 hr) was used to study gastric secretion. DDC (200, 400 and 800 mg/kg) inhibited acid secretion to about 80% of the control level. Histopathological examination of the gastric mucosa after administration of DDC revealed mucosal congestive findings from 1 hr to 3 hr. These data suggested that the mechanism of DDC-induced gastric ulcer formation may be attributable to a decreased level of GMBF and O2- production owing to decreased SOD activity.

Animals↗
PubMed1990

Oxytocin is the major prolactin releasing factor in the posterior pituitary.

Although the posterior pituitary is known to contain the PRL releasing activity or factor (PRF), its chemical identification has been a matter of dispute. In the present study, we purified PRF in porcine posterior pituitary extracts to chemically determine the primary structure. PRF activity was assessed during purification by the release of immunoreactive PRL from superfused rat pituitary cells. Two hundred seventy porcine posterior pituitaries were boiled, homogenized, and extracted with 2 M acetic acid. The acid extract was precipitated with 67% acetone, and the supernatant was absorbed onto a C18 column. The column was eluted step-wise with 10, 20, 30, 40, 50, and 60% acetonitrile (CH3CN) in 0.1% trifluoroacetic acid (TFA). The greatest PRF activity was recovered in the 30% CH3CN/0.1% TFA fraction and was further purified by ion-exchange chromatography on SP-Sephadex, followed by gel-filtration on Sephadex G-50. The Sephadex G-50 fractions with major PRF activity were finally purified by two cycles of reverse phase HPLC, yielding a single peak of PRF. Amino acid, as well as sequence analyses, indicated that the highly purified PRF was oxytocin. Authentic oxytocin showed the same chromatographic behavior and biological activity as those of the isolated peptide. In another experiment, desalted crude extracts of rat and porcine posterior pituitary tissues were directly chromatographed by reverse phase HPLC, and each fraction was assayed for PRF activity. Only two areas showed PRF activity; the largest activity coeluted with oxytocin and the smaller one co-eluted with vasopressin. The fractions which coeluted with oxytocin also showed oxytocin immunoreactivity, as examined by RIA. The results clearly indicated that the major PRF in these posterior pituitary extracts was oxytocin.

Amino Acid Sequence↗
PubMed1990

Effect of electric field on erythrocyte sedimentation rate. II. Dependence on electric current.

We measured the electric current dependence of sedimentation curves of swine erythrocytes in a saline solution at the volume fraction of erythrocytes H = 0.091 and 0.220. The sedimentation curve fitted well to the exponential type equation l = a[1-exp(-bt)] at the upward initial electric current I0 = 0.50 mA, 1.01 mA and 1.50 mA, where l is the length of the medium layer at time t, and a and b are phenomenological parameters. The initial slope v0 of sedimentation curve was enhanced from 0.68 mm/hr at I0 = 0 mA to 2.85 mm/hr, 3.87 mm/hr and 5.50 mm/hr at I0 = 0.50 mA, 1.01 mA and 1.50 mA, respectively, for H = 0.220. We also made sedimentation measurements of erythrocytes in their own plasma at H = 0.220 and 0.316. Sedimentation curves coincided with the sigmoidal type equation l = l infinity/[1 + (t50/t)beta] at I0 = 0 mA and 0.50 mA, where l infinity is l at t----infinity, t50 is the time when the plasma level falls to l infinity/2 and beta is a constant. The maximum slope vmax of sedimentation curve increased from 13.29 mm/hr at I0 = 0 mA to 18.65 mm/hr at I0 = 0.50 mA for H = 0.220.

Animals↗
PubMed1990

Conjunctival allergenicity-supporting factor (CASF) in DIIIa as the sea squirt antigen capable of inducing asthmatic attack and conjunctival reaction in sea squirt asthma.

Among three glycoproteins, DIIIa, Ei-M, and Gi-rep, isolated from sea squirt as antigens capable of eliciting skin reaction specific to sea squirt allergy, only DIIIa induces asthmatic attack and conjunctival reaction, whereas Ei-M and Gi-rep do not. Periodate oxidation eliminated not only the conjunctival allergenicity but also the skin allergenicity from DIIIa, suggesting that the conjunctival and skin allergenicity could both be ascribed to the epitope residing in the carbohydrate chains of DIIIa. On the other hand, proteolysis with Pronase E and chemical modifications of the carboxyl or amino groups by various methods eliminated the conjunctival allergenicity from DIIIa, whereas the skin allergenicity was still retained. Therefore, the expression of conjunctival reaction was expected to be supported by a relatively small structural factor residing in the protein moiety of DIIIa, which we have tentatively designated as conjunctival allergenicity-supporting factor (CASF). CASF might contribute to the permeability of the antigen into mucosa, enabling the carbohydrate epitope to interact with the allergy-specific IgE distributed in conjunctiva and bronchi . In specificity analysis of a rabbit anti-DIIIa serum, a periodate oxidation- and acid-stable but heat- and alkali-unstable epitope (type gamma) in the protein moiety of DIIIa was also characterized as a useful marker of the antigen. However, the type gamma epitope was apparently independent of CASF that was substantially stable to alkali and heat.

Animals↗
PubMed1990

[Enhancement of antitumor activity of mitomycin C against human breast carcinoma xenografts by pretreatment with KM 2210].

Three human breast carcinoma xenografts, MCF-7, R-27 and T-61 serially transplanted into nude mice were treated with mitomycin C (MMC) alone, KM2210 (estra-1, 3, 5(10)-triene-3, 17 beta-diol, 3 benzoate 17-[4-(4-bis(2-chloroethyl)amino)phenyl)-1-oxobutoxy)acetate) alone and KM2210 followed by MMC. One hundred or 300 mg of KM2210 per kg were administered orally daily from Day 1 to 4 and MMC at the dose of 3 mg/kg was given ip on Day 5. The antitumor activity of MMC on these xenografts was enhanced by pretreatment with KM2210, suggesting a new combination chemo- and endocrine therapy of hormone-dependent human breast carcinomas.

Animals↗
PubMed1990

Improvement in the therapeutic efficacy of an asthma-inducing sea squirt antigen termed DIIIa by its polymerization in hyposensitization of sea squirt allergy.

Polymerization using glutaraldehyde markedly improved the apparently low efficacy of an asthma-inducing sea squirt antigen, DIIa (MW 9,980), in hyposensitization therapy on patients with sea squirt allergy. A product (poly-DIIa-G) comparable to Gi-rep (MW 106,000) in MW-distribution showed high therapeutic efficacy comparable to the most effective therapeutic antigen, Ei-M, which was paralleled by a significant increase in the allergen-specific IgG titer in most of the successfully hyposensitized patients as assayed using Ei-M as the target antigen. Another product (poly-DIIa-E) comparable to Ei-M (MW 22,800) in MW also showed a high but slightly lower therapeutic efficacy relative to poly-DIIIa-G with an apparent increase in the specific IgG titer in some patients. However, no significant change in the IgG titer was detected in most patients unsuccessfully treated with intact DIIIa. On the other hand, no significant change was detected in the IgE titer specific to the target antigen in the patients, except in a few cases where the change was independent of the therapeutic effect. The apparent correlation between the increase in the specific IgG titer and the enhancement of the therapeutic effect suggested that polymerization enhanced the immunogenicity of DIIIa and resulted in a significant improvement in the therapeutic efficacy through an additional induction of the specific IgG capable of competing, as a blocking antibody, with the specific IgE for an asthma-inducing antigen, like DIIIa, in patients treated with the polymerized antigens.

Animals↗
PubMed1989

A columnar arrangement of dendritic processes of entorhinal cortex neurons revealed by a monoclonal antibody.

Immunohistochemical screening of the cat limbic system using a panel of monoclonal antibodies (MAbs) revealed that MAb R2D5 specifically labeled a subset of layer 3 cells in the entorhinal cortex, while leaving layer 2 cells unlabeled. The apical dendrites of the R2D5-positive layer 3 cells tended to gather and formed columnar structures which penetrated layer 2 and climbed to the surface of entorhinal cortex.

Animals↗