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Biomedical subjects

W Sato

Publications and source records attributed to W Sato.

100 records · Page 6Linked to original sources
PubMed1976

Guinea pig histocompatibility antigens. I. Serological and genetic characterization of GPLA antigens.

Lymphocytotoxic alloantisera were obtained by cross immunization among outbred guinea pigs from a closed colony. Groups of antisera recognizing the same specificities were established by panel analysis, cross immunization among appropriate phenotypes, and absorption studies. Three antigens designated B1, B2, and B3 (perviously B, C, and D) were detected in our outbred colony and also found to be present in a wide variety of guinea pig strains. These antigens were shown by population and breeding studies to be allelic gene products of a first guinea pig locus (GPLA) (designated locus B). Four new guinea pig families homozygous for their B locus antigens are now in the seventh generation of inbreeding. NIH guinea pig strains 2 and 13, which share the B1 antigen, differ by a number of other antigens which have been designated I1, I2, I3 (previously A), and I4. These antigens differ from the B locus gene products in their molecular size and tissue distribution and it is, therefore, postulated that they represent an equivalent of the Ia antigens in mice (designated I region). Cross immunizations among inbred or outbred guinea pigs identical for currently known B locus and I region antigens yield further antisera, possibly recognizing additional Ia specificities and/or a second GPLA locus designated locus S. Whereas the conventional eosin lymphocytoxicity technique easily permits the detection of the widely distributed antigens (such as the B locus antigens), a more sensitive 51Cr release technique is required to demonstrate the "Ia equivalent" antigens of the guinea pig, possibly due to their restricted presence on the membrane of only some lymphoid cell populations.

Absorption↗
PubMedDate not supplied

Evaluation of the fracture site mechanical properties in vivo by monitoring the motion of a dynamic pin clamp during simulated walking.

OBJECTIVE: To monitor pin clamp motion using a displacement sensor over time during weight bearing and to investigate whether this method could contribute to quantitative assessment of the mechanical properties of fracture healing. METHODS: Patients with a shaft fracture of the tibia were monitored, all of whom were in the stage of dynamization. The hifixator equipped with a ball bearing mechanism was used as a dynamic external fixator. The displacement was recorded versus time during stamping with weight bearing of the patients. The displacement curve had an oscillatory component synchronized with touch down and lift up of the foot, a time-dependent component expressed by shifting of the baseline, and an irreversible component during a non-weight bearing period after stamping. The three components were analyzed with a simple Voigt model. RESULTS: In all patients, both the amplitude of the oscillatory component and the time-dependent component expressed as retardation time decreased as fracture healing proceeded, and by the time of fixator removal the irreversible component had disappeared. CONCLUSIONS: The monitoring method could quantitatively evaluate viscoelastoplasticity of the healing fracture site. RELEVANCE: Until now, there has been few method for assessing the viscoelastic property of the healing fracture site in vivo. Although the method described here involves some assumptions and approximations, it was able to quantitatively assess the viscoelasticity of the healing fracture site.

Adult↗
PubMedDate not supplied

Plasma vascular endothelial growth factor in Japanese Type 2 diabetic patients with and without nephropathy.

AIM: To determine whether plasma vascular endothelial growth factor (VEGF) level is elevated in Type 2 diabetic patients with an early stage of diabetic nephropathy. METHODS: We studied 71 Japanese Type 2 diabetic patients with normal serum creatinine level (<100 micromol/l) (age 63.0 [60.3-65.6] years old, diabetes duration 15.6 [14.0-17.3] years, HbA1c 7.36% [7.06-7.66%], mean [95% confidence interval, CI]): normoalbuminuric patients (n=36); microalbuminuric patients (n=21); and proteinuric patients (n=14). Plasma VEGF concentration was measured by a quantitative sandwich enzyme immunoassay technique. RESULTS: Plasma VEGF concentration was not related to the degree of albuminuria: normoalbuminuric patients (25 [13-95] ng/l, median [25th-75th percentile]); microalbuminuric patients (33 [15-120] ng/l); and proteinuric patients (54 [17-107] ng/l). Plasma VEGF level in patients with retinopathy (25 [15-95] ng/l, n=30) was not elevated as compared to those without retinopathy (53 [14-126] ng/l, n=34). Plasma VEGF tended to correlated negatively with diabetes duration (R's=-.217, P=.0690) and HbA1c (R's=-.221, P=.0647), whereas there was no correlation between plasma VEGF level and age, serum creatinine or urinary albumin to creatinine ratio (ACR) of the patients, respectively. Plasma VEGF level in the group of patients with HbA1c equal to or below the median (<7.2%) was significantly higher than that in the group of patients with HbA1c above the median (>7.2%) (P<.05). CONCLUSIONS: The results suggested that Type 2 diabetic patients with microalbuminuria and those with retinopathy are not necessarily associated with an elevation of circulating plasma VEGF concentration. Plausible association between plasma VEGF level and glycemic control remains to be seen.

Aged↗
PubMedDate not supplied

Cross-resistance of human multidrug-resistant cells to mitomycin C.

Human multidrug-resistant cells, K562/ADM, KB-C-4, AdrRMCF-7 and CEM/VLB100 showed 21-, 7.5-, 105- and 3.4-fold cross-resistance to mitomycin C (MMC). The resistance to MMC in K562/ADM, KB-C-4, AdrRMCF-7, CEM/VLB100 cells was reversed by 6.6 microM verapamil. Accumulation of [3H]MMC in K562/ADM, AdrRMCF-7 and CEM/VLB100 cells also decreased by 37, 26 and 33%, as compared with their drug-sensitive counterparts. In KB-C-4 cells, accumulation of [3H]MMC decreased by 60%, and efflux rate of [3H]MMC was slightly increased as compared to their parental KB-3-1 cells. Verapamil at 6.6 microM increased accumulation of [3H]MMC in these multidrug-resistant sublines. K562/ADM10, K562/ADM50, K562/ADM100 and K562/ADM250 cells, which showed 17- to 230-fold resistance to Adriamycin, also showed 0.8- to 7.3-fold cross-resistance to MMC. In these cell lines, the extent of resistance to Adriamycin (ADM) that was consistent with expression levels of P-glycoprotein shown by immunoblotting was directly proportional to the extent of their resistance to MMC. Regression analysis indicated that relative resistance to Adriamycin was correlated with relative resistance to MMC (r = 0.98). These results indicate that MMC can be transported by P-glycoprotein overexpressed in multidrug-resistant cells.

Doxorubicin↗
PubMedDate not supplied

Weight change of various light-cured restorative materials after water immersion.

This study investigated weight changes of various light-cured glass-ionomer cements and other restorative materials during water immersion and compared findings with those of conventional glass-ionomer cement and light-cured resin composites. Three light-cured glass-ionomer cements, two polyacid-modified composite resins, one conventional glass-ionomer cement, and one light-cured composite resin were evaluated in this study. The weight changes of these specimens after water immersion were measured using an electronic analytical balance and adjusted according to water solubility measured at the same time weight change was measured. The results were analyzed by one-way ANOVA and Scheffé's F test at P < 0.05. The weight change of Photac-Fil Aplicap was the largest, and there were significant differences among the materials (P < 0.05). Weight change after 6 weeks' water immersion was noted in the following order: Fuji Ionomer Type II LC, Vitremer, Fuji Ionomer Type II, VariGlass VLC, Geristore V, and Clearfil AP-X. It is suggested that the amount of water sorption of light-cured glass-ionomer cements is greater than that of polyacid-modified composite resins.

Absorption↗