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A Yoshimoto

Publications and source records attributed to A Yoshimoto.

At least 91 records · Page 5Linked to original sources
PubMed1988

[The effect of some possible factors in c-peptide immunoreactivity in urine on the quality of the results].

About 15% of CPR-U did not correspond between two kinds of kits in the routine assay, which were produced by different pharmaceutical firms, and also it is realised that the effect of the preservative, storage condition and buffer dilutions can not be overlooked in quality control programmes. Based on these problems, following results are concluded; (1) Urine preservative: NaN3 is better than toluene. (2) Urine CPR was stable for added preservative at 4 degrees C for two weeks. (3) Diluents may effect the CPR-U results, if not kept in good condition. The role of the makers in supporting improved quality in clinical laboratory tests will be expected.

C-Peptide↗
PubMed1987

Periapical cemental dysplasia with multiple lesions.

3 cases of periapical cemental dysplasia with multiple lesions in both maxilla and mandible are reported. All 3 patients are middle-aged females with an average age of 47 years; histological examination of excised tissue revealed that the lesions were composed of fibrous connective tissue and cementum-like hard tissue. The location of the teeth affected were mainly in the premolar-molar regions. A subsequent literature survey of previously described Japanese cases of periapical cemental dysplasia disclosed a similar distribution pattern for the location of PCD lesions. This evidence indicates that the occurrence sites of lesions of periapical cemental dysplasia is predominantly in premolar-molar regions in Japan, contrary to the location of PCD in other ethnic groups.

Adult↗
PubMed1987

The induction of cyanide-resistant respiration in Hansenula anomala.

Cyanide-resistant respiration was induced in the yeast, Hansenula anomala in the presence of cyanide or antimycin A, which blocks the electron transport after ubiquinone. The de novo protein synthesis in cytosol and oxygen were deduced to be involved in this induction process. The period required for the induction varied during the growth stage, suggesting that involvement of additional physiological factor(s) in this induction process. The organism could multiply in the presence of antimycin A by developing cyanide-resistant respiration despite a decreased growth rate.

Cyanides↗
PubMed1987

[Studies on the RAST method using tray added disc].

The radioallergosorbent test (RAST) provides a reliable method for detecting of specific IgE antibodies against a wide variety of antigens. The method using tube added disc for the estimation have been widely used in routine assay. In this study, the method using tray added disc has developed in our laboratory. The results were as follows; (1) The method using tray showed good correlation to the original method. (2) Characteristics of the method are rapidity, simplicity and economics. (3) The reaction well of tray is flat bottomed and is good for disc reaction. (4) Coefficients of variation for intra assay were; (d1): 9.40-9.68%, inter assay were 10.39-12.15% respectively. (5) The seasonal variation of positive allergens and the correlation of d to h, g1 to g3 were estimated. The method using tray seems to be one of the most useful routine methods of RAST assay and checking the seasonal variation of RAST will give good advantages to estimate the regional pollution of pollens allergy.

Antibodies, Anti-Idiotypic↗
PubMed1985

Enhanced production of ethylene from methional by iron chelates and heme containing proteins in the system consisting of quinone compounds and NADPH-cytochrome P-450 reductase.

The addition of iron chelates or heme containing proteins to the systems consisting of NADPH-cytochrome P-450 reductase and quinone compounds, such as vitamin K3 (menadione), adriamycin, tetrahydropyranyladriamycin, daunomycin, aclacinomycin A, carbazilquinone, and mitomycin C, showed the enhanced production of ethylene from methional. In the vitamin K3 system, the effective iron chlates were Fe(II)-EDTA, Fe(II)-ADP, Fe(II)-bleomycin A2, and hemin, and the effective iron containing proteins were methemoglobin, myoglobin, ferredoxin, and partially purified cytochromes P-450, P-420, and b5, and the reversed effects were observed by horse radish peroxidase and sulfite reductase from yeast. In the system consisting of aclacinomycin A and methemoglobin, the ethylene production was potently inhibited by radical scavengers, such as Tiron, Tris, thiourea, and KI, and weakly inhibited by some other scavengers. In the system containing vitamin K3 and methemoglobin, the ethylene production was potently inhibited by catalase, but partially by superoxide dismutase, KCN, and NaN3. In this system, the absorption spectrum of methemoglobin was immediately changed to oxyform and quenched with time, and catalase protected the decrement of the spectrum. The addition of hydrogen peroxide or cumene hydroperoxide to methemoglobin also produced ethylene from methional.

Aldehydes↗
PubMed1985

Alpha-lactalbumin as a lysosomal enzyme-releasing factor.

In the early stage of mammary gland involution, biochemically detectable lysosomal damage occurs. The mechanism(s) underlying this damage is not well understood. We found that alpha-lactalbumin from mouse milk induced the release of enzymes from the lysosomes of mouse mammary epithelial cells in vitro, and this induction also occurred with bovine alpha-lactalbumin. This enzyme release was accelerated by the addition of whey proteins with a molecular weight of 50 000 to 60 000. We also found that the lysosomal membrane of mammary epithelial cells had a strong affinity for alpha-lactalbumin.

Animals↗
PubMed1985

Process of the combination of alpha-lactalbumin with lysosomes in mammary epithelial cells.

We previously reported that alpha-lactalbumin combines with the lysosomal membrane of mammary epithelial cells and that it acts to release lysosomal enzymes. However, the details of this combination within the cells remained undetermined. We now report that 125I-bovine-alpha-lactalbumin in the medium entered mouse mammary epithelial cells, and about 13 per cent of the alpha-lactalbumin that entered the cell bound to lysosomes. About 75 per cent of the alpha-lactalbumin that reached the lysosome was tightly bound to the lysosomal membrane. It appears that alpha-lactalbumin in the secretory vesicles does not migrate out, because murine and bovine whey did not induce the release of Golgi enzymes in vitro.

Animals↗
PubMed1985

Antitumor activities of (2"R)-4'-O-tetrahydropyranyl-adriamycin (THP) and its combination with other antitumor agents on murine tumors.

(2''R)-4'-O-Tetrahydropyranyladriamycin (THP) is a new derivative of doxorubicin (adriamycin, ADM). The concentrations of THP and ADM required to inhibit by 50% the growth of a cultured L1210 cells was 0.003 microgram/ml and 0.016 microgram/ml, respectively. Various therapeutic designs of combinations of THP with other antitumor agents were investigated in vivo using the L1210 murine leukemia. The combination of THP with cytosine arabinoside (Ara-C), cyclocytidine hydrochloride (Cyclo-C), 6-mercaptopurine (6-MP) and cyclophosphamide (EX) showed a great effectiveness following daily intraperitoneal treatment from days 1 to 10. High therapeutic effects were also obtained with the combinations of THP with Ara-C, Cyclo-C, vincristine (VCR) and EX following intravenous combination therapy one day following implantation of L1210 leukemia. Schedule dependency and its therapeutic efficacy of THP were examined. THP showed almost the same antitumor activity on the solid-type sarcoma-180 or solid-type Ehrlich carcinoma as ADM by intraperitoneal or intravenous treatment. THP showed some superior activity to ADM in the advanced stage of L1210 leukemia. High antitumor activity of THP on murine leukemia L1210 has been reported by Tsuruo et al. (Cancer Res. 42: 1462-1467, 1982) and was also confirmed. THP gave many mice cures, especially in the intravenous treatment.

Animals↗
PubMed1982

Studies on yeast sulfite reductase. V. Effects of ionic strength on enzyme activities.

Yeast sulfite reductase (EC 1.8.1.2) has the unique property that it is inactivated at low ionic strength. The effects of ionic strength on various enzyme activities were investigated and the characterization of the inactivation was carried out. The multiple activities shown by this enzyme were all nullified by exposing the enzyme to low ionic strength, except for reduced methyl viologen-sulfite reductase activity, which was increased rather than decreased. The Km values for NADPH and sulfite were not significantly affected by ionic strength. When the enzyme was reduced with NADPH at low ionic strength, the height of the peak at 455 nm was decreased to one-half of the fully-reduced level, while the height of the peak at 587 nm was unchanged. These results, together with the experiment using an FMN-depleted apoenzyme, indicate that the inactivation at low ionic strength was caused by the interception of the electron flow between FAD and FMN. The inactivation at low ionic strength was reversible, but the restoration of the activity was dependent on the incubation period at low ionic strength and the protein concentration. The kinetics and the effect of glycerol and/or 2-mercaptoethanol on the inactivation and the restoration showed that further change, including oxidation of SH groups, should occur in the enzyme through prolonged incubation at low ionic strength. Changes in the enzyme structure related to these results are described in the subsequent paper.

Flavin Mononucleotide↗
PubMed1982

Studies on yeast sulfite reductase. VI. Use of the effects of ionic strength as a probe for enzyme structure and mechanism.

The effects of ionic strength on the structure of yeast sulfite reductase (EC 1.8.1.2) were investigated. Gel filtration and sedimentation analysis revealed that this enzyme dissociated at ionic strength below 0.1 into two components having molecular weights of 300000 and sedimentation coefficients of 7-9 S. The secondary structure and the surroundings of the prosthetic groups were not appreciably affected by ionic strength. This enzyme showed CD spectra in the near-ultraviolet region considered to be due to tyrosine residues. On lowering the ionic strength, they decreased, together with the disappearance of the difference spectra in the same region, indicating that some tyrosine residues became exposed to the environment at low ionic strength. SH groups were also exposed at low ionic strength and reacted with DTNB and PCMB more easily to cause the loss of NADPH-sulfite reductase activity. These essential SH groups as well as some tyrosine residues may exist in the region of contact between the two components constituting the enzyme molecule.

Chloromercuribenzoates↗
PubMed1982

Studies on yeast sulfite reductase. IV. Structure and steady-state kinetics.

Yeast NADPH-sulfite reductase (hydrogen sulfide:NADP+ oxidoreductase, EC 1.8.1.2) is a complex hemoflavoprotein. The Strokes radius was determined to be 80 A by gel filtration and the molecular weight was estimated to be 604,000. The minimal molecular weight calculated from flavin and heme content was 306,000, indicating that this enzyme contains two FAD, two FMN and two hemes per molecule. The enzyme consists of two types of subunit, alpha and beta, having molecular weights of 116,000 and 167,000, respectively. The subunit structure is suggested to be alpha 2 beta 2. The secondary structure, the amino acid composition and the isoelectric point were also investigated. The Km values for sulfite and NADPH were 17 microM and 10 microM, respectively. Sulfite and NADPH affected the reaction velocity to give parallel Lineweaver-Burk plots, indicating the involvement of the 'ping-pong' mechanism in the overall reaction. NADP+ inhibited the reaction competitively with NADPH and noncompetitively with sulfite. Inhibition by sulfide was partially noncompetitive with both substrates but very weak. These results are discussed and compared with sulfite reductase from Escherichia coli.

Amino Acids↗