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Biomedical subjects

K Ogata

Publications and source records attributed to K Ogata.

At least 487 records · Page 27Linked to original sources
PubMed1982

Interaction of 5S RNA-L5 protein complex with 40S subunits in rat liver ribosomes.

When rat liver 80S ribosomes or polysomes were dissociated into their subunits by EDTA-treatment, a 5S RNA-L5 protein complex was present in EDTA-derived small subunits, and released from the subunits by urea. The interaction of 5S RNP with the small subunits did not occur in the case of 80S couples formed from 40S and 60S subunits in the presence of Mg2+, indicating that the attachment of 5S RNP to EDTA-derived small subunits was not an artifact caused by the unfolding of the subunits. These results give direct evidence that 5S RNP is located at the interface between large and small subunits, and suggest that 5S RNP binds to the 40S subunit in the functioning polysomes, but not the 80S couples.

Animals↗
PubMed1982

[Use of a lipid lymphographic agent, lipiodol, as a carrier of high molecular weight antitumor agent, smancs, for hepatocellular carcinoma].

Two advantages of the present therapeutic approach were described. Firstly, a selective deposition of lipiodol in tumor tissue was verified, thus more precise and accurate diagnosis by X-rays was possible either by CT or plain X-ray film. Secondly, pronounced accumulation of smancs in tumor tissue was observed, which established highly effective chemotherapy of unresectable hepatoma of 22 cases and 12 other cases based on (a) decrease in alpha-fetoprotein (86%), (b) tumor size (95%) and histology. Drug was given via the hepatic artery mostly 3-4 mg in 3-4 ml of lipiodol once every 3 to 4 weeks. Most patients have experienced a total dose of 6-8 mg in two cycles, but drug activity lasted more than 3 weeks. Neither hematosuppression nor anaphylaxis was observed. Major side effect was transient fever (38-39 degrees C) in about 50% of the cases which lasted no more than one week. Other minor side effect was abdominal pain during or after arterial infusion which lasted for about 20 min. Liver function was affected very slightly if any. Mild leukocytosis was observed in 65% of the patients.

Adult↗
PubMed1982

Effect of Staphylococcus aureus Cowan i bacteria on the mitogenic response of human B-cell subsets.

We have made a detailed investigation to determine which of the B-cell subsets could be stimulated by Staphylococcus aureus Cowan I bacterium (SpA CoI). B-cell subsets were separated from peripheral blood and tonsil lymphocytes by means of rosette formation with E, EAIgG, anti-immunoglobulin (Ig) conjugated OE (OE-Pro A) or by separation on a bovine serum albumin (BSA) discontinuous density gradient. The cells responding to SpA CoI included E receptor negative (E-), C3 receptor positive (C3R+), and surface Ig positive (SIg+) B-cell subsets. Among these B-cell subsets, FcR-n cells were more responsive than FcR+ cells. These B-cell subsets responded alone to SpA CoI and significantly proliferated, although, they failed to respond alone to pokeweed mitogen (PWM) and Protein A of S. aureus (Protein A). Among the SIg+ B-cell subsets stimulated with SpA CoI, IgM+ and IgG+ B cells showed much less response. Both Protein A receptor positive (Pro A . R+) and negative (Pro A . R-) cells responded well to SpA CoI. Fractionation of B cells on a BSA gradient revealed that comparatively small sized and denser B-cell subsets responded well to SpA CoI. From these criteria, it is suggested that B cells responding to SpA CoI are capable of stimulating not only mature B cells, but can also stimulate immature B cells.

B-Lymphocytes↗
PubMed1982

Symposium on Surface Replacement Arthroplasty of the Hip. Socket and cup surface replacement.

Pain relief is the most striking feature following this procedure. In Group I, in which the metal acetabular socket and the metal femoral cup were used, 60 per cent of the patients gained satisfactory pain relief at five to nine years of follow-up. In Group II, in which the metal-polyethylene socket and the metal cup were used, 84 per cent of the patients gained satisfactory pain relief, with 1 to 5 years of follow-up. There have been 12 revision cases in the 130 hips operated on, with the average time to revision being 3 years and 10 months. Revision procedures consisted of the conventional total hip replacement (seven cases), replacement of the socket and/or the cup (four cases), and arthrodesis (one case). The secondary operations could be performed without difficulties, probably because no bone cement was used in our surface replacement. No cases of pulmonary embolism, thrombophlebitis, deep infection, heterotopic ossification, or femoral neck fracture were encountered after the procedure.

Adult↗
PubMed1981

Identification of neighboring protein pairs cross-linked with dimethyl 3,3'-dithiobispropionimidate in rat liver 40S ribosomal subunits.

Rat liver 40S ribosomal subunits were treated with a bifunctional imidoester, dimethyl 3,3'-dithiobispropionimidate (DTP), and the neighboring protein pairs were identified. The cross-linked proteins were analyzed by acrylamide/SDS diagonal gel electrophoresis (Sommer & Traut (1974) Proc. Natl. Acad. Sci. U.S. 71, 3946-3950). The cross-linked components that fell off the diagonal upon adding 2-mercaptoethanol in the second dimension were labeled with 125I in the acrylamide gel and identified by two-dimensional acrylamide/urea gel electrophoresis, followed by radioautography. Considering these results and the molecular weights, we propose the following ten pairs, according to our numbering system (Terao & Ogata (1975) Biochim. Biophys. Acta 402, 219-229): S3-S5 (S3/S3a-S4), S3-S14 (S3/S3a-S14), S3-S17 (S3/S3a-S16), S5-S22 (S4-S23/S24), S10-S12 (S8-S11), S9-S16 (S9-S18), S9-S22 (S9-S23/S24), S6-S23 (S5-S25), S17-S21 (S16-S19), and S16-S26 (S18-S27). The designation according to the proposed uniform nomenclature (McConkey et al. (1979) Mol. Gen. Genet. 169, 1-6) are given in parentheses.

Animals↗
PubMed1981

Ribosomal proteins cross-linked to natural mRNA by UV irradiation of rat liver polysomes.

After rat liver polysomes were irradiated with UV light at 254 nm for 2 h, a cross-linked poly(A)-containing mRNA-protein complex (mRNP) was prepared and a protein moiety was labeled with 125I. After RNase treatment, its protein moiety was analyzed by two-dimensional polyacrylamide gel electrophoresis followed by radioautography. There were radioactive spots which extended from the positions of those of S3/S3a, S6, L5, and L6/L7 towards the origin. In the case of UV irradiation for 30 min, radioactive spots extending similarly from those of S3/S3a, and L5 were observed. Radioactive areas on the two-dimensional gel in the case of irradiation for 2 h were further analyzed by SDS polyacrylamide gel electrophoresis. The peaks of radioactivity were detected at the protein band containing L6, that containing S3a and L5 and that containing S6, L7, and L8. It was proposed that S3a, S6, L5, and L6 proteins, according to the proposed uniform nomenclature (McConkey et al. (1979) Mol. Gen. Genet. 169, 1-6(1)), were cross-linked to mRNA by UV irradiation.

Animals↗
PubMed1981

Stimulation of Immunoglobulin production from human B lymphocytes by Staphylococcus aureus: effects of monocytes and con A-induced suppressor cells.

Significant immunoglobulin (Ig) production by human peripheral blood lymphocytes was induced in vitro by stimulating the cells with pokeweed mitogen (PWM) and Staphylococcus aureus Cowan I (SpA CoI). IgG, IgM, and IgA were determined by a combination of the latex fixation test and radioimmunoassay. High levels (1,000 to 5,000 microgram/ml of IgG and IgM and a lesser amount of IgA were constantly produced during 7 to 8 days of incubation with both stimulants. Ig production induced by SpA CoI stimulation was independent of the presence of T cells, while Ig production induced by PWM required T cells exclusively. Depletion of monocytes in the culture caused but a slight decrease in Ig production (particularly in the case of IgG). While the addition of a small number of monocytes enhanced IgG induction by both stimulants, coculture with an excess number of monocytes inhibited Ig induction (particularly IgG) by PWM stimulation but not by SpA CoI stimulation. Marked suppression of Ig production (IgG, IgM, and IgA) was observed in cocultures with Con A-activated T cells. The phenomena of suppression were observed in both the SpA CoI-stimulated and PWM-stimulated lymphocytes. These data indicated that Ig production from B cells and relatively of independent of monocytes, but could be subjected to the regulation of the Con A-induced suppressor T cells.

Antibody Formation↗
PubMed1981

Lack of effective messenger RNA for beta 2-microglobulin in a gestational human choriocarcinoma cell line (GCH-1).

When two lines of gestational human choriocarcinoma cells (GCH-1 and GCH-2) were incubated with [35S]methionine, the labeled beta 2-microglobulin was not detected on sodium dodecyl sulfate:polyacrylamide gel electrophoresis after purification of the labeled protein with affinity chromatography, using rabbit antibody against beta 2-microglobulin as the ligand. In contrast, in the case of nongestational choriocarcinoma cells originating from male stomach cells, the incorporation of [35S]methionine into beta 2-microglobulin was observed. When polyadenylate-containing messenger RNA prepared from GCH-1 cells was incubated with [35S]methionine in a rabbit reticulocyte lysate system, the labeling of beta 2-microglobulin was not shown. On the other hand, when polyadenylate-containing messenger RNA from nongestational choriocarcinoma cells was incubated in the same cell-free system, labeled beta 2-microglobulin was detected. These results indicate that beta 2-microglobulin is not synthesized in gestational human choriocarcinoma cells and at least in the case of GCH-1, beta 2-microglobulin is not synthesized owing to the lack of effective messenger RNA for beta 2-microglobulin.

Animals↗