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Biomedical subjects

T Okuda

Publications and source records attributed to T Okuda.

At least 379 records · Page 21Linked to original sources
PubMed1988

Renal tubular mechanisms for excretion of cefpiramide (SM-1652) in association with its long-lasting pharmacokinetic properties.

To investigate possible mechanisms for the long-lasting pharmacokinetic properties of cefpiramide, pharmacokinetic and renal clearance studies were carried out using rabbits. Cefazolin was employed as a reference compound. In pharmacokinetic studies, the plasma half-life (t1/2 beta) for cefpiramide was 2.7 times as long as that for cefazolin. The total body clearance (ClT) and renal clearance (ClR) for cefazolin were approximately 2.3 times larger than those for cefpiramide. In renal clearance studies, the clearance by glomerular filtration (Clf) for cefpiramide exceeded Clf for cefazolin by 2.5 times, because of lower plasma protein binding of cefpiramide. In contrast, the clearance by tubular secretion (Cls) for cefpiramide was one-fifth as small as Cls for cefazolin. The overall renal clearance (Clr) for cefazolin was 3.6 times as large as Clr for cefpiramide, being in good agreement with the cefazolin/cefpiramide ratios of ClT and ClR. Therefore, the long-lasting pharmacokinetic properties of cefpiramide was suggested to be due to the fact that cefpiramide undergoes renal tubular secretion to less extent.

Animals↗
PubMed1988

Involvement of Mac-1 antigen in tumor cell killing by macrophages.

Some tumor cells such as YAC-1 and RL male 1 were killed by mouse peritoneal macrophages elicited with OK-432 one day before the harvest. The killing reactions were inhibited specifically by anti-Mac-1. The results suggest that some macrophages generated early after the injection of OK-432 kill tumor cells with the aid of CR3.

Animals↗
PubMed1988

Effects of low protein intake on protein metabolism of Papua New Guinea highlanders studied with [15N]glycine.

The effects of low protein intake on protein metabolism, including the size of pools and the protein synthesis rates, were studied by use of [15N]glycine in Papua New Guinea highlanders. Studies were made on 9 men between October and December in 1982. In experiment 1, two subjects were given a protein-free diet (PFD) containing 49.1 kcal/kg of energy. In experiment 2, subjects were given a sweet-potato diet (SPD) containing 45.4 kcal/kg of energy and 0.507 g/kg of protein for 8 days, and then were given a low-protein sweet-potato diet (LPSPD) containing 50.0 kcal/kg of energy and 0.265 g/kg of protein. During the SPD period, the sizes of the metabolic and active protein pools (mean +/- SD) were 270 +/- 134 mgN/kg and 362 +/- 107 mgN/kg, respectively, and the rates of active and inactive protein synthesis were 463 +/- 161 mgN/kg/day and 299 +/- 38 mgN/kg/day, respectively. During the LPSPD period, the sizes of the metabolic pool and active protein pool were 131 +/- 64 mgN/kg and 378 +/- 106 mgN/kg, respectively, and the rates of active and inactive protein synthesis were 490 +/- 206 mgN/kg/day and 280 +/- 26 mgN/kg/day, respectively. The protein metabolism in the LPSPD showed no significant difference from the SPD. The results suggest that, when the energy levels were approximately the same, protein metabolism in Papua New Guinea highlanders was maintained in spite of the decrease in protein intake.

Adult↗
PubMed1988

Feline immunodeficiency syndrome--a comparison between feline T-lymphotropic lentivirus and feline leukemia virus.

A feline T-lymphotrophic lentvirus (FTLV) has recently been isolated from a domestic cat free of feline leukemia virus (FeLV). This virus is distinct from FeLV (an oncornavirus), although they share a common denominator, namely, the ability to cause immunosuppression and induce lymphadenopathy and anemia. Their differences can be revealed by examining the following: the metal requirement for reverse transcriptase activity, the antigenic comparison by Western blot analysis, the different susceptibilities of a variety of feline cells, and the morphology based on electron microscopy. In the serological survey of 1,612 cats surveyed in the USA, 232 (14.4%) were seropositive for antibodies to FTLV, which was lower than for the 42 Canadian cats surveyed of which 8 (19%) were seropositive. Of the 61 cats positive for FeLV, 15 (25%) were also positive for FTLV, giving the impression that coinfection between these two retroviruses plays an important role in the cliniocpathological signs of what was previously thought to be solely an FeLV syndrome.

Animals↗
PubMed1988

Restriction fragment length polymorphism of bcr in Japanese patients with hematological malignancies.

We surveyed DNAs from patients with various hematological malignancies by Southern blot hybridization to analyze bcr rearrangements, and detected a new restriction fragment length polymorphism (RFLP) of the breakpoint cluster region at a BamHI site in three patients. By using a 1.2-kb HindIII-BglII 3' bcr probe, unusual BamHI restriction enzyme fragments (1.9 kb and 1.4 kb) were detected from the DNAs of three patients with hematological malignancies. DNAs from cultured fibroblasts derived from the skin of a patient, as well as from peripheral leukocytes of the father of a patient and the mother of another patient, showed identical 1.9- and 1.4-kb additional bands, besides a 3.3-kb germline band, establishing that polymorphism, rather than gene arrangement, was responsible for these additional restriction enzyme fragments. However, RFLP was not detected in the DNAs of 40 normal unrelated individuals.

Blotting, Southern↗
PubMed1988

Effect of tannin on oxidative damage of ocular lens.

The protective effect of geraniin (tannin from Geranium thunbergii) against oxidative damage was examined in the mouse ocular lens. Oxidative damage in the lens was induced by diamide, diazene dicarboxylic acid bis (N,N-dimethylamide); diamide oxidized the sulfhydryl groups in both the membrane and cytoplasm but did not increase lipid peroxide. Geraniin showed protective effects on the changes in the Na+/K+ ratio, GSH level, Na,K-ATPase activity, GSH reductase activity and the sulfhydryl level of the membranous protein in the diamide-treated lens, but such protective effects of geraniin were not observed in the cell-free system of the lens. In addition, geraniin itself was unable to reduce GSSG to GSH and also unable to inhibit the oxidative reaction of the sulfhydryl group to diamide. These results suggest that in the intact lens geraniin would act primarily on the lens cell membrane surface to inhibit an influx of diamide into the inner part of the plasma membrane and the cytoplasm, and consequently that geraniin may protect sulfhydryl groups in the cell membrane and cytoplasm from their oxidation by diamide and keep the redox system of the lens in a normal state.

Animals↗
PubMed1988

Stimulation of plasma fibronectin production in mice by muroctasin.

The production of plasma fibronectin (PFN) in mice treated subcutaneously with N2-[(N-acetylmuramoyl)-L-alanyl-D-isoglutaminyl]-N6-stearoyl-L-lysine (MDP-Lys(L18), muroctasin), was examined. The plasma levels of PFN in mice increased significantly by treatment with a single dose of 10 to 100 micrograms/mouse of MDP-Lys(L18). A slight strain difference in the PFN levels among Std: ddY, C3H/He, and DBA 2 mice was observed: the percent increases at the maximal level in Std: ddY, C3H/He, and DBA/2 mice were 21.6, 19.9, and 10.4, respectively. In Std: ddY mice, the concentration of PFN reached the maximal level at 15 h post-treatment, and decreased gradually of the normal level by 48 h. These results indicate that MDP-Lys(L18) stimulates the PFN production in mice.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMed1988

A clone with a chromosome abnormality, i(17q), in the myeloid crisis of chronic myeloid leukemia is able to differentiate into neutrophil, basophil and eosinophil lineages.

Simultaneous cytogenetic and morphologic observations of single colonies derived from granulocytic precursor cells were performed on a patient with chronic myelogenous leukemia (CML) during the myeloid crisis. Colonies having a Ph1 chromosome and i(17q) were found to consist of neutrophilic/basophilic, eosinophilic/basophilic or basophilic granulocytes. These findings led to the conclusion that cells having the additional abnormality, i(17q), are still able to differentiate into neutrophil, basophil and eosinophil lineages. In other words, this chromosome abnormality does not give a proliferative advantage to a restricted cell lineage.

Adult↗