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Biomedical subjects

M Okazaki

Publications and source records attributed to M Okazaki.

At least 523 records · Page 29Linked to original sources
PubMed1984

Production of a monoclonal antibody-methotrexate conjugate utilizing dextran T-40 and its biologic activity.

Methotrexate (MTX), a folate antagonist and anticancer agent, was linked covalently to murine monoclonal anti-HLA IgG1 antibody (H-1) with the use of dextran T-40 as a multivalent carrier. As determined spectrophotometrically, the conjugate was composed of 9.20 mol MTX per 1 mol antibody. Of the substituted MTX, 46.3% (4.30 mol MTX per 1 mol antibody) exhibited inhibitory activity on dihydrofolate reductase. The MTX conjugated to H-1 [MTX-(H-l)] showed significantly stronger cytotoxicity against HLA-bearing cells than cells lacking HLA (p less than 0.001) in cultivation after a 2-hour exposure to the drugs. In the same experiment, free MTX showed equivalent cytotoxicity to cells both bearing and lacking HLA. When cells were cultivated for 3 days with the drugs, MTX-(H-l) also showed significantly stronger cytotoxicity than free MTX or MTX-control IgG conjugate against HLA-bearing cells (p less than 0.001), and the MTX-(H-l), MTX-control IgG, and free MTX showed equivalent cytotoxicity to cells lacking HLA. Our results indicate that the MTX-(H-l) conjugate binds to the cell surface antigen by its antibody action and exerts greater MTX cytotoxicity than free MTX in vitro.

Animals↗
PubMed1983

Production of a monoclonal antibody-bleomycin conjugate utilizing dextran T-40 and the antigen-targeting cytotoxicity of the conjugate.

Bleomycin (BLM), a potent anticancer glycopeptide antibiotic, was linked covalently to murine monoclonal anti-HLA IgG1 antibody (H-1) with the use of dextran T-40. As determined spectrophotometrically, the conjugate was composed of 57.5 moles BLM per mole antibody. Of the substituted BLM, 18.4% (10.6 moles BLM per mole antibody) exhibited antimicrobial activity. The BLM-(H-1) conjugate showed stronger cytotoxicity than BLM alone against HLA-bearing cells in cultivation after a 30-min exposure to the drugs. In the same experiment, the conjugate was less toxic than BLM against cells lacking HLA.

Antibodies, Monoclonal↗
PubMed1983

Abnormalities in plasma lipoprotein in familial partial lecithin:cholesterol acyltransferase deficiency.

Abnormalities in plasma lipoproteins from patients with familial partial lecithin:cholesterol acyltransferase deficiency were studied. In these patients the plasma cholesterol ester ratio was about 40% and plasma apolipoprotein B level remained within the normal range. The content of large-sized low-density-lipoproteins (LDL) was low. Apolipoprotein B-100 and B-48 were detected in very-low-density lipoproteins (VLDL) and LDL in patients' plasma. In patients' LDL, apolipoprotein B-48 was primarily present in large-sized particles. Apolipoprotein E and A-I were mainly detected in intermediate-sized LDL. High-density lipoproteins (HDL) were separated into three fractions by gel permeation chromatography. Large-sized HDL particles (150-200 A) including discoidal particles contained apolipoproteins, E, A-IV and A-I. The content of discoidal HDL was low and, on electron micrograph, rouleau-formed particles were rarely seen. Normal-sized HDL (80-100 A) contained apolipoproteins A-I and A-II and small-sized HDL (about 60 A) contained only apolipoprotein A-I. Although several lipoprotein abnormalities were similar to those in classical familial lecithin:cholesterol acyltransferase deficiency, remaining lecithin:cholesterol acyltransferase activity may, however, cause a lack of reduction of apolipoprotein B level, a low level of large-sized LDL and also a low level of discoidal HDL.

Adult↗
PubMed1983

Mass transfer rates in hemodialyzers--an empirical correlation.

From the experimental data on the rates of urea transfer from blood to dialysate in a test hemodialyzer, a practical equation for the effect of the hematocrit on the blood-phase urea transfer coefficient is proposed. With this equation, the overall mass transfer coefficient that takes into account the properties of the blood can be estimated for the commercially available disposable flat membrane-type and hollow fiber-type hemodialyzers from the data for a relatively simple dialysate--dialysate system.

Animals↗
PubMed1983

F--CO3(2-)-interaction in IR spectra of fluoridated CO3-apatites.

Spectroscopic properties of fluoridated CO3-apatites were studied by means of infrared (IR) absorption analysis. The peak of the IR band caused by CO32-ions at 875 cm-1 shifted to a lower frequency with the degree of fluoridation. This result suggests that there is a significant interaction between F and CO32-ions in the apatite crystals. The interaction of both these ions is discussed with regard to the solubility behavior of fluoridated CO3- apatites in the acetate buffer solution at pH 4.0 and at 37 degrees C. Solubility of these fluoridated CO3-apatites approached that of fluoridated hydroxyapatites at high fluoride content.

Apatites↗
PubMed1983

The accuracy of occlusal cusp height in cast crowns.

Despite a good fit at the finish line, the occlusal cusp height decreased about 80 micron in gypsum-bonded cristobalite investments and increased about 40 micron in phosphate-bonded investments. Disks, tested as simulated occlusal portions of cast crowns, produced similar dimensional changes. This finding suggests that the occlusal cusp height is closely related to the thickness of the disk. An asbestos liner used with a gypsum-bonded investment failed to furnish adequate cushioning. The Kaowool liner provided good accuracy to the occlusal portion and finish line of cast complete crowns.

Calcium Sulfate↗
PubMed1983

Simple method for analysis of apolipoproteins in high density lipoproteins by high performance liquid chromatography.

A simple and rapid method has been developed for the separation of apolipoproteins in high density lipoprotein (HDL) fractions by high performance liquid chromatography (HPLC) with gel permeation columns (G3000SW TSK GEL). The HPLC pattern monitored by A280 for a mixed solution of the HDL fraction (10 microliter) and an eluent buffer (200 microliter, 0.1 M sodium phosphate buffer containing 0.1% SDS) incubated at 60 degrees C for 5 min showed two completely separated peaks which corresponded to the major components of human HDL, apolipoprotein A-I and A-II. Moreover, quantitation of apolipoprotein A-I by our method was found to correlate well with that by a single radial immunodiffusion (SRID) assay.

Apolipoproteins↗