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S Masuda

Publications and source records attributed to S Masuda.

At least 361 records · Page 20Linked to original sources
PubMed1986

[High performance liquid chromatographic determination of astromicin and cefoperazone used in combination in blood samples].

Combination therapy of aminoglycoside and beta-lactam antibiotics is often used clinically because of its effectiveness. This paper reports a high performance liquid chromatographic (HPLC) determination method for each of astromicin (ASTM) and cefoperazone (CPZ) in blood samples of several species. The procedure for ASTM included purification with CM-Sephadex, separation on a reversed phase column (C-18) and derivatization with o-phthalaldehyde (OPA). The procedure for CPZ included deproteinization with methanol, centrifugation and separation on a reversed phase column (C-18). Either of the drugs did not affect the determination of the other. The detection limits were 0.1 microgram/ml for ASTM and 0.5 microgram/ml for CPZ. These sensitivities seem good enough for a clinical application of the method considering usual dosage levels of the drugs.

Aminoglycosides↗
PubMed1986

[High performance liquid chromatographic determination of astromicin and piperacillin used in combination in blood samples].

Aminoglycoside and beta-lactam antibiotics are often used in combination, and many synergistic effects have been reported. We describe here a high performance liquid chromatographic determination method for each of astromicin (ASTM) and piperacillin (PIPC) in blood samples of several species. The procedure for ASTM included purification with CM-Sephadex, separation on a reversed phase column (C-18) and derivatization with o-phthalaldehyde (OPA). The procedure for PIPC included deproteinization with acetonitrile, centrifugation and separation on a reversed phase column (C-18). Either of the drugs did not affect the determination of the other. The detection limits were 0.1 microgram/ml for ASTM and 0.5 microgram/ml for PIPC. These sensitivities seem good enough for a clinical application of the method considering usual dosage levels of these drugs.

Aminoglycosides↗
PubMed1985

A Z-DNA binding protein isolated from D. radiodurans.

A DNA binding protein isolated from D. radiodurans changes CD-spectrum of Z-form poly(dG-dC) X poly(dG-dC). We have found that a positive band at 268 nm is converted close to that of B-form in the presence of the protein. Concomitantly, a negative band at 295 nm shown by Z-form poly(dG-dC) X poly (dG-dC) was weakened by the protein but not by albumin. Such changes in the CD-spectra were not induced by the protein and by albumin when they were mixed with Z- or B-form poly(dG-me5dC) X poly(dG-me5dC) or with B-form poly(dG-dC) X poly(dG-dC). The protein formed a complex preferentially with Z-form poly(dG-dC) X poly(dG-dC).

Circular Dichroism↗
PubMed1985

Comparison of drug-metabolizing activities in the livers of carcinogen-sensitive parent rats and carcinogen-resistant descendants.

Donryu strain albino rats were maintained on a diet containing 0.06% 3'-methyl-4-dimethylaminoazobenzene (3'-Me-DAB) for nine successive generations. Some rats in the fourth to eighth generations showed marked resistance to the carcinogenic action of 3'-Me-DAB. In the liver where we found tumors, their size and number are smaller than in the corresponding original strain of rats fed on a diet containing 3'-Me-DAB. No significant differences were found in the total cytochrome P-450 contents or epoxide hydrolase activities of the livers of the resistant variant and the original strain, but the benzo(a)pyrene hydroxylase activity which is mainly attributed to cytochrome P-448 and glutathione S-transferase activity of the resistant variant were lower. The inductions of hepatic cytochrome P-488 and benzo(a)pyrene hydroxylase on administration of polychlorinated biphenyls or 3-methylcholanthrene were also lower in the resistant rats. In the mutagenicity test on Salmonella typhimurium TA 98 the liver 9000 X g supernatant fraction from 3'-Me-DAB-resistant F7 rats did not fully induce the mutagenicities of 3'-Me-DAB and several other carcinogens. Thus the resistance of F7 rats to the chemical carcinogen may be related to the lower activities of some drug-metabolizing enzymes and the poor inducibility of cytochrome P-448 in their liver, although selection of resistant rats should be continued for further generations before coming to a definite conclusion on biochemical basis of apparent resistance to 3'-Me-DAB.

Animals↗
PubMed1984

Application of high-performance liquid chromatography with synchronized accumulating radioisotope detector to analysis of glyceryl trinitrate and its metabolites in rat plasma.

A new, sensitive, and specific high-performance liquid chromatographic method for the quantitative analysis of [14C]glyceryl trinitrate and its four metabolites in plasma is described. The drugs are extracted from 0.05 ml of plasma with methanol and analyzed by high-performance liquid chromatography using a synchronized accumulating radioisotope detector. The limit of detection is 0.2 ng per injection. The within-day coefficient of variation is 5.9% at a concentration of 27.0 ng per ml of plasma. The method was applied to single-dose pharmacokinetics of glyceryl trinitrate in rat.

Animals↗
PubMed1984

Tumoricidal adsorption of Staphylococcus aureus organisms on Ehrlich ascites tumor cells sensitized with rabbit antibody.

A tumoricidal effect was observed when protein A-bearing Staphylococcus aureus organisms were adsorbed on Ehrlich ascites tumor cells previously sensitized with antiserum from a rabbit immunized with Ehrlich ascites tumor cells. Electron micrographs showed that staphylococci were firmly attached to the tumor cells, which might explain how effectively the attached cocci killed the tumor cells. The tumoricidal effect was confirmed not only by an in vitro experiment but also by an in vivo one. The possible applications of the tumoricidal adsorption as an indicator for staphylococcal virulence or for selective anti-tumor action was discussed.

Adsorption↗
PubMed1984

Lymphoid interstitial pneumonia associated with depressed cellular immunity and polyclonal gammopathy.

This report describes a case of lymphoid interstitial pneumonia (LIP) associated with polyclonal gammopathy and selective depression of cellular immunity. Enhanced humoral immunity is suggested because the patient exhibited increased levels of circulating immunoglobulin (chiefly IgG) and a positive test reaction for rheumatoid factor. When first examined, the patient displayed depressed cellular immunity in that the results of his skin test were negative to dinitrochlorobenzene and phytohemagglutinin (PHA), his peripheral lymphocytes responded suboptimally to PHA, and he had decreased numbers of circulating T cells. When examined 6 yr later, the patient was again hypergammaglobulinemic, but he had regained some of his cellular immune function. Eight years after the patient was initially seen, he showed further improvement in cellular immune function. Analysis of bronchoalveolar lavage cells showed that the patient had a normal proportion of OKT4+ (inducer/helper) cells, but a reduced number of OKT8+ (suppressor/cytotoxic) cells. Thus, his improvement may have been associated with a correction of an imbalance of immunoregulatory T cells. Furthermore, because the disease was active on initial examination but less active after the second evaluation, malfunction of his cellular immune functions may have been involved in the pathogenesis of LIP.

Humans↗
PubMed1984

The physiochemical and immunological characteristics of rat lymph binding protein for 25-hydroxyvitamin D3.

The binding proteins for 25-hydroxyvitamin D3(25-OH-D3) in rat lymph and plasma were purified to apparent homogeneity as determined by sodium dodecyl sulfate disc gel electrophoresis. The purification procedures included the following techniques: gel filtration on Sephadex G-100 and G-200; affinity chromatography on Blue Sepharose CL-6B; ion-exchange chromatography on DEAE-Sepharose CL-6B; chromatofocussing on a Mono P column. Both proteins from lymph and plasma were eluted with the same retention time from an isoelectric column at a pH of approximately 4.53 and showed nearly identical data on the analysis of amino acid composition. When specific anti-lymph 25-OH-D3-binding protein antiserum was prepared in a rabbit, and Ouchterlony immunodiffusion was performed, the same precipitate line was observed on both lymph and plasma binding proteins. These results strongly suggest that a common transport protein exists in both rat lymph and plasma and circulates in the blood-lymph system.

Amino Acids↗
PubMed1984

The presence of siderosomes in synovioblasts (B cells) of chronic spontaneous hemarthrosis. Histologic, electron microscopic, and roentgenographic electron microanalysis studies of three cases.

The synovium of three patients with chronic spontaneous hemarthrosis was examined by light and electron microscopy and roentgenographic electron microanalysis. The synovium showed hyperplastic villous processes with proliferation of synovioblasts (B cells) and synovial macrophages (A cells). Erythrophagocytosis was observed in synovial macrophages but not in synovioblasts. Synovioblasts, however, had more numerous siderosomes than did synovial macrophages. Ferritin granules were identified in the cytoplasms of synovial macrophages and synovioblasts as well as in the intercellular space. It was noted that the longer the interval following the hemorrhagic episode, the fewer the siderosomes and erythrophagosomes in synovial macrophages. Therefore, it is likely that synovioblasts take up ferritin and/or inorganic iron released from synovial macrophages in chronic local iron overload.

Adult↗
PubMed1984

Postirradiation parosteal osteosarcoma. A case report.

A 16-year-old Japanese boy received a high dose of radiation for treatment of eosinophilic granuloma in the femur at the age of two years. He presented with a parosteal osteosarcoma 14 years later. Although a number of cases of postirradiation osteosarcoma have been reported, reports of parosteal osteosarcoma following radiation therapy are rare.

Adolescent↗
PubMed1984

[Antihypertensive effect of trifluoropentoxypicolinic acid: a pharmacokinetic study].

Two drugs, trifluoropentoxypicolinic acid (TFP) and 5-butoxypicolinic acid, which are composed of a picolinic acid skeleton and an alkoxyl group, were studied to determine characteristics of their antihypertensive effect. The study was carried out using normotensive rats and experimental hypertensive rats (DOCA type hypertensive, one-kidney type hypertensive and spontaneous hypertensive), and effects of these drugs were compared with those of fusaric acid (5-butylpicolinic acid), which is known as a hypotensive agent inhibiting dopamine beta-hydroxylase. The hypotensive effect of the drugs (10, 30 and 100 mg/kg, p.o.) on normotensive rats was weaker than on hypertensive rats. TFP showed a dose-dependent hypotensive effect which was not influenced by reserpine pretreatment. Though TFP showed the same inhibitory effect on serum dopamine beta-hydroxylase as fusaric acid, it had only approximately 0.5 times the inhibitory activity. However, TFP had a hypotensive effect which was 1.4 times stronger than that of fusaric acid. According to pharmacokinetic analysis based on the determination of blood drug concentration, the transfer rate of fusaric acid from the digestive tract to the blood was much higher than TFP by 1.6 X 10(4) times. Moreover, fusaric acid had a 4.5 times greater disappearance rate than TFP. From the above results, first of all, it is supposed that the antihypertensive effect of TFP is related to inhibition of dopamine beta-hydroxylase. In addition, it is suggested that prolonged presence of unchanged TFP in the blood increases its immediate depressive effect on the cardiovascular system, thereby causing a strong hypotensive effect.

Animals↗