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Biomedical subjects

A Ishiguro

Publications and source records attributed to A Ishiguro.

At least 73 records · Page 4Linked to original sources
PubMed1990

[Studies on the mechanism of protective effect of selenium on nephrotoxicity of cis-diamminedichloroplatinum (CDDP) in mice].

The mechanism of protective effect of sodium selenite (Se) on the nephrotoxicity of cis-diamminedichloroplatinum (CDDP) was studied with mice. CDDP and Se concentrations in the plasma, blood cell, kidney and liver were measured in mice given CDDP alone and those given both CDDP and Se. The nephrotoxicity of CDDP was observed in mice fed Se deficient diet (SDD). The activities of glutathione peroxidase (G-Px) in the plasma, blood cells, kidney and liver were measured in mice mentioned above. Co-administration of Se did not influence on the concentration of CDDP in the blood, kidney and liver. In mice fed SDD, the nephrotoxicity of CDDP increased and G-Px activities of the blood and kidney decreased. In mice given Se, G-Px activities was not increased. These results suggest that interaction between CDDP and Se differs from that between mercury and Se, or between cadmium and Se (formation of compound). Intake of Se is related to the appearance of the nephrotoxicity of CDDP. G-Px may be related partially to the protective effect of Se on the nephrotoxicity of CDDP.

Animals↗
PubMed1989

[Effect of a protein-bound polysaccharide, PSK, on human hemopoietic progenitors].

Using in vitro clonal culture assays, we investigated the effects of PSK, a protein-bound polysaccharide derived from the cultured mycelium of CM101, Coriolus versicolor (Fr.) Quél in Basidiomycetes, on human hemopoietic progenitors. PSK alone did not stimulate colony formation by human bone marrow progenitors. Although 1-100 micrograms/ml of PSK had no effects on colony formation stimulated by erythropoietin and medium conditioned by phytohemagglutinin-stimulated leukocytes, more than 1 mg/ml of PSK inhibited all types of colony formation. In contrast, medium conditioned by PSK-stimulated leukocytes significantly stimulated formation of various types of colonies including erythroid bursts, granulocyte and/or macrophage colonies, eosinophil colonies, megakaryocyte colonies and mixed hemopoietic colonies. It is speculated that administration of the optimal dose of PSK can reduce the hematological suppression of antitumor drugs.

Cell Division↗
PubMed1988

Synergism of BSF-2/interleukin 6 and interleukin 3 on development of multipotential hemopoietic progenitors in serum-free culture.

We investigated the effects of B cell stimulatory factor 2/interleukin 6 (BSF-2/IL-6) on the development of murine hemopoietic progenitors using serum-containing culture and serum-free culture. In serum-containing culture, BSF-2 mainly supported multipotential blast cell colonies from spleen cells of normal and 5-fluorouracil (5-FU)-treated mice. In serum-free culture, no colony growth was seen in the presence of BSF-2. Addition of BSF-2 to the serum-free culture containing IL-3 resulted in a significant increase in the number of colonies formed from multipotential progenitors in spleen cells and bone marrow cells of 5-FU-treated mice, whereas no effects were seen on the number of single or oligolineage colonies formed by the spleen cells of normal mice. These results suggested that BSF-2 and IL-3 act synergistically on the multipotential progenitors but not on the maturer progenitors. When BSF-2 was added to a culture containing low concentrations of IL-3 (1 U/ml, 4 U/ml), which had little effect on colony formation, the number of total colonies formed by the spleen cells and bone marrow cells of 5-FU-treated mice increased significantly. The combination of BSF-2 and 40 U/ml of IL-3 resulted in a significant enlargement of GMM colonies. Thus, BSF-2 appears to enhance the sensitivity of multipotential hemopoietic progenitors to IL-3.

Animals↗
PubMed1988

[Cell cycle analysis using the monoclonal antibody Ki-67].

We determined by flow cytometry the proportion of cells in cycle with the monoclonal antibody Ki-67 and also in S-phase after incorporation of bromodeoxyuridine (BrdUrd) with monoclonal antibody to BrdUrd. The monoclonal antibody Ki-67 was useful to detect a nuclear antigen present only in proliferating cells but not expressed in resting (Go) cells. Cell preparation to measure BrdUrd amount incorporated into cellular DNA was difficult but this anti-BrdUrd antibody was useful for measuring the rate of DNA synthesis and for the analysis of precious cell kinetics. These antibodies may provide useful information of cell kinetics.

Antibodies, Monoclonal↗
PubMed1988

Increases in neutrophil counts by purified human urinary colony-stimulating factor in chronic neutropenia of childhood.

Clinical effects of purified human urinary colony-stimulating factor (CSFHU) were studied in nine patients with chronic neutropenia of childhood who ranged in age from 1 to 18 years. The patients were given CSFHU at a dose of 6 x 10(6) U/m2/d for seven consecutive days, and their peripheral neutrophil counts were serially followed for 6 to 12 months. In addition, changes in bone marrow morphology and granulocyte-macrophage colony-forming cells (GM-CFUs) were studied. Transient increases in neutrophil counts occurred during the first 4 weeks in all patients except one. Repeated increases were seen in a cyclic fashion in five patients. Three of the patients recovered from the neutropenia after several cycles of fluctuation of neutrophil counts; the counts (per microliter) reached 5,880, 5,640, and 2,000 as compared with pretreatment levels (mean +/- 2 SD) of 80 +/- 164, 182 +/- 250, and 2 +/- 14, respectively. The percentage (mean +/- SE) of marrow neutrophilic cells increased from 30.4% +/- 7.0% to 34.9% +/- 6.9% (P less than .05) and the ratio of the later neutrophil precursors to the earlier ones from 1.02 +/- 0.27 to 1.42 +/- 0.36 (P less than .02) 2 weeks after CSFHU infusion. There were no changes in GM-CFU numbers. These results indicate that CSFHU can increase neutrophil counts by increasing the number and maturity of the marrow neutrophil precursors in some types of childhood chronic neutropenia.

Adolescent↗
PubMed1986

[Immediate surgical revascularization following unsuccessful coronary thrombolysis: effects on myocardial salvage].

To reduce early and late mortality and morbidity following acute myocardial infarction (AMI), myocardial salvage of the jeopardized areas by coronary thrombolysis (PTCR) during the acute period is effective. However, unsuccessful thrombolysis or severe residual coronary stenosis may result in severe cardiac failure and high mortality in the early and late periods. This study was undertaken to demonstrate the effects of immediate coronary artery bypass surgery (CAB) following unsuccessful PTCR. Thirty-three patients with initial AMI were studied, in whom PTCR was performed within 10 hours of onset of chest pain but it was unsuccessful. In 16 cases (Group I) total occlusion could not be recanalized, and in 17 cases (Group II) subtotal residual stenosis (99% with delayed flow on coronary angiogram) remained. The effects of immediate CAB surgery (Group I-b: 4 cases; Group II-b: 9 cases) for myocardial salvage were evaluated by thallium-201 scintigraphy one to 14 months after onset of AMI, as compared to medical therapy (Group I-a: 12 cases; Group II-a: 8 cases). The thallium uptake in the jeopardized area was categorized as (1) defect (+), (2) decrease, and (3) defect (-). All 12 cases in Group I-a showed defect (+). In Group I-b, one case showed defect (+), one case decreased, and two cases defect (-). In Group II-a, seven of eight cases (88%) showed defect (+) and one case showed decrease; however, in Group II-b seven of nine cases (78%) showed defect (-) and two cases showed defect (+). The effects on myocardial salvage were significantly different between Group a and Group b (p less than 0.001) and Group II-a and Group II-b (p less than 0.01). In conclusion, immediate CAB surgery was superior to medical therapy for ischemic myocardial salvage following unsuccessful PTCR. These results encourage the application of immediate postinfarction CAB surgery in high-risk groups with severe residual coronary stenosis after PTCR.

Aged↗
PubMed1985

Single-cell origin of human mixed hemopoietic colonies expressing various combinations of cell lineages.

We have established single-cell culture for human mixed hemopoietic colonies using a micromanipulator. Mononuclear cells from human umbilical cord blood were cultured at a concentration of 1 X 10(4) cells per milliliter in methylcellulose medium containing medium conditioned by phytohemagglutinin-stimulated leukocytes and erythropoietin. It was possible to identify the single hemopoietic progenitors in situ in methylcellulose culture on the basis of unique morphology and migratory ability after 36 to 60 hours of incubation. Candidate single hemopoietic progenitors from methylcellulose medium were individually micromanipulated to secondary culture dishes and cultured for an additional ten to 14 days. The colonies derived from the single progenitors were individually picked and stained with May-Grünwald-Giemsa for analyses of the cellular composition. A total of 288 single cells were individually transferred to second dishes. Then 186 single cells produced secondary colonies consisting of cells in one to five different lineages. A total of 39 single cells produced mixed hemopoietic colonies consisting of cells in two, three, four, and five different lineages. There were eight types of colonies revealing two different lineages, ie, neutrophil (n)-erythrocyte (E), macrophage (m)-E, m-megakaryocyte (M), eosinophil (e)-basophil (b), eE, bE, bM, and EM lineages. Three types of colonies consisting of cells in three lineages were also seen, ie, nmM, nbE, and ebE. There were six types of colonies consisting of cells in four lineages, ie, nmbM, nmEM, nebE, mebM, and meEM. One type of colony consisted of cells in five different lineages (nmbEM). These results indicate the single-cell origin of human mixed hemopoietic colonies expressing various combinations of cell lineages. It also provides experimental data in support of stochastic mechanisms of stem cell differentiation.

Azure Stains↗