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Biomedical subjects

M Mineshima

Publications and source records attributed to M Mineshima.

8 recordsLinked to original sources

Correlation between the proliferative response to granulocyte colony-stimulating factor and the positivity of transferrin receptor in acute myeloblastic leukemia cells.

The use of granulocyte colony-stimulating factor (G-CSF) after chemotherapy for acute myeloblastic leukemia (AML) has been reported. However, there is a drawback in that G-CSF may stimulate the proliferation of AML progenitors. To determine the parameter(s) indicative of responsiveness of AML blasts to G-CSF, various surface phenotypes of blasts were examined in relation to the blast colony formation stimulated by G-CSF in 39 AML patients. A correlation was found only with transferrin receptor positivity among the various phenotypes studied. The population mean of percentages of transferrin receptor-positive blasts in the group responding to G-CSF in vitro was significantly higher than that of blasts in the group not responding to G-CSF. A further correlation was found between transferrin receptor positivity and the number of G-CSF receptors on the blasts; that is, blasts expressing more G-CSF receptors have greater transferrin receptor positivity. In our previous study, we observed that blasts with a large number of G-CSF receptors produce more colonies in response to G-CSF. These results indicated that blasts expressing more transferrin receptors have a larger number of G-CSF receptors and may show more active proliferation in response to G-CSF. Therefore, the proliferative response of blasts to G-CSF can be predicted by examining transferrin receptor positivity. The clinical use of G-CSF in AML patients may be recommended when the patient's blasts have a low level of transferrin receptor expression. The measurement of transferrin receptors on blasts, instead of the rather complicated G-CSF receptor determination, would be a useful indicator for the safer application of G-CSF in AML patients.

Antigens, CD

Microscopic observation of leukocyte kinesis in the vascular bed during hemodialysis using the rabbit ear chamber technique.

Leukocyte kinesis in the capillary vascular bed during hemodialysis (HD) was investigated to elucidate the mechanism of transient leukopenia. Leukocyte movement was observed microscopically during HD using the rabbit ear chamber (REC) technique, which permits visualization of the movement of blood corpuscles in capillaries. Blood was drawn from the femoral artery and returned into the auricular and/or carotid artery so that the blood passing through the hollow fiber artificial kidney (HFAK) flowed into capillaries in the REC. Leukocyte counts of blood samples taken from the afferent and efferent limbs of the HD circuit, the right jugular vein and the right atrium were determined consecutively during HD. The difference in the leukocyte count was observed between the afferent and efferent limbs for the first 15 minutes and thereafter between the efferent limb and the jugular vein. The "transpulmonary" difference in the leukocyte count was not noticed throughout HD. Between 15 and 90 minutes after the start of HD, scarcely any circulating leukocytes were found in capillaries in the REC and some leukocytes were attached to the endothelial surface. Thereafter circulating leukocytes were seen again and detachment of leukocytes from the endothelial surface was observed. No leukocyte aggregation or embolization of aggregating leukocytes was noticed. This evidence suggests that leukopenia may be attributed to the transient shift of leukocytes to the marginal pool of the vessel lumen and this process may not be specific for the pulmonary vasculature, but may occur in the first capillary bed into which the blood passing through the HFAK flows.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals

Development of continuous recirculating peritoneal dialysis using a double lumen catheter.

Continuous recirculating peritoneal dialysis (CRPD) was newly introduced to improve solute removal efficiency in conventional dialysis therapies such as hemodialysis (HD) and continuous ambulatory peritoneal dialysis (CAPD). In CRPD, a part of the dialysate in the peritoneal cavity was drained through a double-lumen catheter and purified by an extracorporeal dialyzer. Urea removal characteristics in CRPD were examined in a canine study. In this study, a recirculation-dialysis experiment using a dog weighing 9.0 kg was carried out under 100 and 200 ml/min of flow for recirculating and delivered dialysates, respectively. An FB-50H (Nipro Medical Industries, Ltd., Osaka, Japan) composed of cellulose diacetate membrane with 0.5 m2 of surface area and Dianeal-1.5 (Baxter Limited Laboratories, Tokyo, Japan) containing urea were used as the extracorporeal dialyzer and dialysate. Urea peritoneal and dialyzer dialysances (DBP and DBD) were 3.05 and 33.3 ml/min by computer simulation using a compartment model for CRPD. This DBP value can be estimated as 20.3 ml/min for a 60 kg human. From this result, time-averaged value for BUN over an 8 hr/day CRPD, combined with three exchanges/day as CAPD is estimated to be 34.3 mg/dl, which is much lower than 45.2 mg/dl for a 12 hr/week HD, or 53.0 mg/dl for conventional CAPD.

Animals

Non-heparin hemodialysis with oral administration of newly developed antiplatelet agent.

Non-heparin hemodialysis (HD) was successfully done in anuric dogs with the oral administration of a newly developed antiplatelet agent, 4-cyano-5,5-bis(4-methoxyphenyl)-4-pentenoic acid, (E5510, Eisai Pharmaceutical Co., Japan). In the current study, the antithrombotic effect of E5510 during HD was investigated. Eleven mongrel dogs with bilateral ureteral ligation were given 0.1 mg/kg of E5510 orally 1 hr before undergoing 4 hr HD using hollow fiber dialyzers, (PMMA 5, regenerated cellulose 6) without heparin and under general anesthesia. Blood samples were taken before the administration of E5510 and before and 1, 2, 3, and 4 hr after starting HD; blood counts, hematocrits, blood chemistries, and plasma thromboxane levels (TxB2) were examined. Platelet aggregation, activated clotting times (ACT), and activated partial thrombin times (APTT) were also measured, and sequential plasma E5510 concentrations were determined. In 10 of 11 anuric dogs, non-heparin HD was successfully done with minimal clotting in the dialyzer and drip chambers. The maximum aggregation rate was depressed to less than 20% of the initial value throughout HD. Plasma TxB2 concentration was depressed, and ACT and APTT were mildly, but not significantly prolonged. Neither hemorrhagic complications nor other side effects of E5510 were observed.

Administration, Oral

Difference in beta 2-microglobulin removal between cellulosic and synthetic polymer membrane dialyzers.

Several kinds of dialyzers, with highly permeable membranes (HPM), have been designed to specifically remove beta 2-microglobulin (BMG). To clarify their solute transport characteristics, nine types of HPM dialyzers were evaluated during in vivo and in vitro studies using human plasma and aqueous solutions. No BMG membrane adsorption and/or plugging was seen with cellulosic membrane dialyzers during in vitro experiments using human plasma. On the other hand, all synthetic polymer membrane dialyzers had adsorptive properties, and in a dialyzer with a polymethylmethacrylate membrane, a large amount of BMG was removed by adsorption alone. Dialyzers with cellulose triacetate and polyacrylonitril membranes showed higher values of BMG diffusive dialysance (greater than 20 ml/min) and sieving coefficient (greater than 0.9). From in vitro experiments using an aqueous solution containing several solutes with relatively small or middle molecular weights, all HPM dialyzers had a higher overall mass transfer coefficient than any conventional membrane dialyzer.

Blood Flow Velocity