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T Sakatani

Publications and source records attributed to T Sakatani.

27 records · Page 2Linked to original sources
PubMed1986

Measurement of active phagocytosis by polymorphonuclear leukocytes by fluorescence liberation from phagocytized microspheres.

Phagocytosis by polymorphonuclear leukocytes (PMN) was determined by a newly developed technique based on measurement of liberation of a fluorescence substance from PMN phagosomes; 4-methylumbelliferyl-beta-D-glucuronide (4MUGL), which is a substrate of beta-glucuronidase in lysosome, was conjugated with a microsphere, and 4-methylumbelliferone (4MU) liberated from phagocytized 4MUGL-microspheres was measured. The microspheres were composed of glyceryl-methacrylate having a diameter of 2.0 micron. Liberating activity of six kinds of 4MUGL-microspheres containing various amounts of amino and carboxyl groups was compared. Among these six kinds of 4MUGL-microspheres, four kinds showed activity similar to that of morphological phagocytosis. These four kinds of 4MUGL-microspheres liberated 4MU into the extracellular fluid from PMN during phagocytosis. Furthermore, they were recognized as a substrate of purified beta-glucuronidase. 4MUGL-MS610 showed the highest liberating activity among the four kinds of microspheres. Optimal conditions for phagocytosis by PMN were determined using 4MUGL-MS610. Total liberation of 4MU from the microspheres increased almost linearly with incubation time with PMN from 0 to 60 min and was linear with 4MUGL-MS in concentrations up to 4 X 10(8) microspheres/ml. This liberation was parallel to phagocytosis in a dose-dependent fashion. During 10-min incubation 20.4% of 4MU was liberated from 4MUGL-microspheres with phagocytosis. Seventy-five percent of the liberated 4MU was distributed in the extracellular fluid. 4MU distributed in the extracellular fluid was not attributable to hydrolysis of unphagocytized microspheres by beta-glucuronidase extracellularly leaked from PMN by phagocytosis. Also phagocytized 4MUGL-MS610 by PMN was observed by scanning electron microscopy. These results indicate that 4MU was liberated from 4MUGL-MS by hydrolysis due to beta-glucuronidase released into phagosomes with phagocytosis by PMN. Sensitivity of this assay was limited to about 50 pmol/ml, being less than 0.5-1 microsphere phagocytized into one cell.

Cell Membrane Permeability↗
PubMed1985

Effects of nicotine on the functions of human polymorphonuclear leukocytes in vitro.

Effects of nicotine on migration, extracellular release of lysosomal enzymes, and superoxide anion (O-2) production of human polymorphonuclear leukocytes (PMN) were studied. Nicotine (5 X 10(-6) to 5 X 10(-4) M) had no effect on random migration, chemotaxis to fMet-Leu-Phe, nor on chemokinesis induced by fMet-Leu-Phe. Nicotine, however, inhibited both extracellular release of lysosomal enzymes from PMN and O-2 production of PMN, both of which were induced by fMet-Leu-Phe and cytochalasin B. The inhibition of enzyme release and O-2 production by nicotine was not affected by atropine, hexamethonium, or acetyl beta-methylcholine, suggesting a direct action of nicotine on PMN functions. It is presumed that nicotine does not affect PMN migration to inflammatory sites, but inhibits the microbicidal functions of PMN. Exposure to PMN to nicotine introduced into the body by smoking could suppress their functions. This might result in harmful influences on the host defense mechanism, including antitumor function.

Cell Survival↗
PubMed1983

Assay method for myeloperoxidase in human polymorphonuclear leukocytes.

A simple assay method for measuring myeloperoxidase (MPO) has been developed. MPO is found in polymorphonuclear leukocytes and is important as a bactericidal agent in the presence of H2O2 and halide ions. This improved assay method is based on work of Andrews and Krinsky using tetramethylbenzidine (TMB) a noncarcinogenic substrate. By assaying MPO under optimal conditions of TMB at 1.6 mM, H2O2 concentration of 0.3 mM, pH 5.4, and incubation temperature of 37 degrees C, sensitivity of MPO measurements increased eightfold in comparison with the original TMB method. A method has been established to determine absorbance at 655 nm of the reaction mixture by incubation for 3 min and then stopping the reaction by the addition of pH 3.0 buffer. An attempt was also made to raise the sensitivity by using 3,3'-dimethyoxybenzidine (DMB), a carcinogenic substrate. The improved TMB method was 34 times more sensitive than the DMB method.

Benzidines↗
PubMed1983

Age-related decline in lysosomal enzyme release from polymorphonuclear leukocytes after N-formyl-methionyl-leucyl-phenylalanine stimulation.

Aging is assumed to decrease lysosomal enzyme release from polymorphonuclear leukocytes (PMN). A synthetic chemotactic peptide, N-formyl-methionyl-leucyl-phenylalanine (fMet-Leu-Phe) was utilized to stimulate enzyme release of PMN from 45 human subjects, 21 males and 24 females, ranging in age from 22-83 yr old. Results of the studies showed no sex differences in the stimulation of enzyme release for either age group. However, stimulation was found to significantly decline in both males and females over 50 yr old compared to subjects under 50 yr old. The linear formulae for beta-glucuronidase, beta-galactosidase and lysozyme in male subjects were Y = 6.5X + 617.2, Y = -1.9X + 311.5 and Y = -1.9X + 327.3 with correlation coefficient of -0.685, -0.352 and -0.401, respectively. The linear formulae in females were Y = -5.2X + 536.6, Y = -3.0X + 340.6 and Y = -1.7X + 333.6 with correlation coefficient of -0.582, -0.303 and -0.462, respectively. These findings suggest that there was an age-related decline of response to the stimulant, fMet-Leu-Phe.

Adult↗
PubMedDate not supplied

Expressions of thymidine phosphorylase (dThdPase) and vascular endothelial growth factor on angiogenesis in intestinal-type gastric carcinoma.

We examined the clinical and pathological significance of thymidine phosphorylase (dThdPase) and vascular endothelial growth factor (VEGF) in human gastric carcinomas, in terms of intratumoral microvessel density (IMVD), P53 expression, and patient prognosis in a total of 128 patients. Mean IMVD was significantly higher in the carcinomas with dThdPase or VEGF expression than in carcinomas without the expression. The simultaneous expression of dThdPase and VEGF was correlated with increased IMVD of human gastric carcinomas. VEGF expression was associated with P53 expression and poor patient prognosis, but dThdPase expression was not.

Adenoma↗
PubMedDate not supplied

Thymidine phosphorylase activity in liver tissue and its correlation with multifocal occurrence of hepatocellular carcinomas.

BACKGROUND: In hepatocellular carcinoma (HCC), new tumors develop in the residual liver within a few years after hepatectomy. However, the biological risk factors of multifocal occurrence of cancers remains unclear. In this study, the thymidine phosphorylase (TP) activity, which is known as an angiogenic factor, of cancerous and non-cancerous liver tissues in HCC was analyzed to determine its suitability as a biological marker of the multifocal occurrence of HCCs. MATERIALS AND METHODS: Fresh tissues (tumor: HCC and adjacent liver tissue: N-HCC) from 63 patients with HCC and normal liver tissues (NL) from 6 patients without HCC were obtained. The TP activities of the tissues were analyzed by an enzyme-linked immunosorbent assay (ELISA). RESULTS: The mean TP activity of 63 HCCs (136 U/mg protein) was higher than that of 63 N-HCCs (81 U/mg protein) and that of 6 NLs (47 U/mg protein, p < 0.001). Multifocal occurrence of HCCs were detected in 17 patients. In these 17 patients, the mean TP activity of HCCs (145 U/mg protein) was not different from that of HCCs from the remaining 46 patients (133 U/mg protein, p = 0.272), however the mean TP activity of N-HCCs (110 U/mg protein) was significantly higher than that of N-HCCs from the remaining 46 patients (71 U/mg protein, p = 0.038). Moreover, only a high TP activity of N-HCCs was detected as a significant risk factor of multifocal occurrence of HCCs. CONCLUSION: Patients who have tumors with high TP activity in the non-cancerous livers may have a risk of multifocal occurrence of HCCs in the residual liver.

Adult↗