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T Suda

Publications and source records attributed to T Suda.

At least 667 records · Page 37Linked to original sources
PubMed1988

Purified interleukin 5 supports the terminal differentiation and proliferation of murine eosinophilic precursors.

Using a clonal culture system, we investigated the hemopoietic effects of purified recombinant IL-5 obtained from conditioned media of transfected Xenopus oocytes. IL-5 alone acted on untreated bone marrow cells and supported the formation of a small number of colonies, all of which were predominantly eosinophilic. However, it did not support colony formation by spleen cells from 5-FU-treated mice, in which only primitive stem cells had survived, while IL-3 and G-CSF did. Eosinophil-containing colonies were formed from these cells in the presence of IL-5 and G-CSF together. In contrast, G-CSF alone did not support any eosinophil colonies. The eosinophilopoietic effect of IL-5 was dose-dependent, and was neutralized specifically by anti-IL-5 antibody. To exclude the possibility of interactions with accessory cells in the same culture dish, we replated a small number (200 cells/dish) of enriched hemopoietic progenitors, obtained from blast cell colonies, which were formed by cultivation of spleen cells from 5-FU-treated mice in the presence of IL-3 or G-CSF. From these replated blast cells, eosinophil colonies were induced in dishes containing IL-5 but not in those containing G-CSF alone. From these findings, it was concluded that IL-5 did not act on primitive hemopoietic cells, but on blast cells induced by IL-3 or G-CSF. IL-5 specifically facilitated the terminal differentiation and proliferation of eosinophils. In this respect, the role of IL-5 in eosinophilopoiesis seems to be analogous to erythropoietin, which promotes the terminal differentiation and amplification of erythroid cells. Moreover, IL-5 maintained the viability of mature eosinophils obtained from peritoneal exudate cells of the mice infected with parasites, indicating mature functional eosinophils carried IL-5 receptors. The synergistic effects of IL-5 and colony-stimulating factors on the expansion of eosinophils is supposed to contribute to the urgent mobilization of eosinophils at the time of helminthic infections and allergic responses.

Animals↗
PubMed1988

Corneal endothelial changes associated with aphakic extended contact lens wear.

Wide-field specular microscopy and computer-assisted morphometry were performed on 20 aphakic eyes in 16 patients who had worn a high-water content hydrogel contact lens on an extended wear basis for at least 12 months (mean, 28 months) following intracapsular cataract extraction. When compared with 22 non-lens-wearing aphakic eyes matched for age and postoperative period, the endothelial cell changes in the above patients included a significantly higher coefficient of variation in cell area (polymegathism) and a marked reduction in the frequency of hexagonal cells (pleomorphism) without any significant difference in cell density. Although the clinical significance of these endothelial changes remains unclear, they may indicate hypoxic stress to the corneal endothelium or be an early sign of ongoing cell loss.

Aged↗
PubMed1988

A differentiation-inducing factor produced by the osteoblastic cell line MC3T3-E1 stimulates bone resorption by promoting osteoclast formation.

We have reported that the differentiation-inducing factor (DIF) is present in conditioned medium of mouse osteoblast-like cell (MC3T3-E1) cultures. In the present study, the DIF from conditioned medium of MC3T3-E1 cells was partially purified and its biologic activity was examined. The DIF was purified by monitoring the induction of phagocytic activity of mouse myeloblastic leukemia cells (M1). The DIF induced differentiation of not only M1 cells but also mouse myelomonocytic cells (WEHI-3). Furthermore, the DIF increased the in vitro bone-resorbing activity and the osteoclast number in mouse calvaria. The increases were inhibited by the addition of either salmon calcitonin or indomethacin. When mouse bone marrow cells were cultured with the DIF for 8 days, formation of osteoclast-like multinucleated cells was stimulated dose dependently. The DIF from MC3T3-E1 cells appeared to be different from interleukin-1 (IL-1), tumor necrosis factor (TNF), and transforming growth factor beta (TGF-beta). These results suggest that the DIF partially purified from osteoblast-like cell cultures stimulates osteoclastic bone resorption by promoting differentiation and fusion of osteoclast progenitors to form multinucleated osteoclasts.

Animals↗
PubMed1988

Calcium is essential in the fusion of mouse alveolar macrophages induced by 1 alpha,25-dihydroxyvitamin D3.

We have reported that the active form of vitamin D3, 1 alpha,25-dihydroxyvitamin D3 [1 alpha,25(OH)2D3], directly induces activation and fusion of mouse alveolar macrophages (Abe et al., 1983, 1984). The activated state appeared to be a prerequisite to the fusion of macrophages. Macrophages began to fuse 36 hr after adding 1 alpha,25(OH)2D3; the fusion rate attained a maximum of 70-80% at 72 hr. During the course of further investigating the mechanisms of fusion induced by the vitamin, we found that the calcium ion is closely involved in the fusion process of macrophages induced by 1 alpha,25(OH)2D3. When alveolar macrophages were cultured with 1 alpha,25(OH)2D3 in medium with graded concentrations (0.13-1.85 mM) of calcium, the fusion rate went down in parallel with the decrease of medium calcium. Neither calcium ionophore A23187 nor 12-O-tetradecanoylphorbol-13-acetate (TPA) induced fusion of freshly isolated macrophages, but the two compounds greatly promoted fusion of the macrophages pretreated for 18 hr with 1 alpha,25(OH)2D3. The vitamin effect for the first 18 hr was similar, irrespective of the medium calcium concentration. In contrast, millimolar amounts of calcium were essential in the subsequent period of incubation(18-72 hr) for inducing fusion. The activation of macrophages measured by the induction of cytotoxicity and the enhancement of glucose consumption by 1 alpha,25(OH)2D3 occurred similarly, irrespective of the medium calcium concentration. These results clearly indicate that the fusion process of alveolar macrophages induced by 1 alpha,25(OH)2D3 can be divided into two phases: 1) the calcium-independent priming phase (0-18 hr) and 2) the calcium-dependent progression phase (18-72 hr). 1 alpha,25(OH)2D3 is necessary only in the priming phase; A23187 and TPA can be substituted for 1 alpha,25(OH)2D3 in the progression phase.

Animals↗
PubMed1988

In vitro study on proopiomelanocortin messenger RNA levels in cultured rat anterior pituitary cells.

The fundamental examination on the measurement of proopiomelanocortin (POMC) mRNA levels in cultured rat anterior pituitary (AP) cells was studied. In addition, the detailed study on time- and dose-related effects of corticotropin-releasing factor (CRF) and dexamethasone on the level of POMC mRNA in AP cells in vitro was examined. Basal levels of POMC mRNA in AP cells cultured with serum initially declined after 1-day culture, gradually increased and reached a peak after 3-day culture, and then slightly decreased after 4- and 5-day culture. These mRNA levels after 3-day culture did not change through subsequent 15-hr incubation without serum. CRF treatment caused a time- and dose-dependent increase in POMC mRNA levels. The minimum effective dose of CRF was 0.1 nM for 15-hr incubation. The significant increase in POMC mRNA levels was observed after 3 hrs of 1 nM CRF treatment with a 2-fold elevation seen after 15 hrs of exposure. Dexamethasone treatment caused a dose-dependent decrease in POMC mRNA levels in AP cells. The minimum effective dose was 0.1 microgram/ml and such mRNA levels did not decrease until 15 hrs of exposure.

Animals↗
PubMed1988

Proliferative effect of human granulocyte colony-stimulating factor on blast cells of acute promyelocytic leukemia.

The effect of human granulocyte colony-stimulating factor (G-CSF) on leukemic cells of acute promyelocytic leukemia (APL) was examined. Mononuclear cells obtained from bone marrow cells containing more than 90% blasts from seven APL patients were incubated in the presence of G-CSF using semisolid and liquid culture systems. On day 7, the cells from all the patients produced many clusters consisting of 8-40 cells. These cells appeared to be promyelocyte-like blast cells in four patients and had differentiated to more mature neutrophils in three patients. On day 14, the number of clusters decreased except for two patients. Blast cells from the two patients showing the increase of blast clusters could proliferate in a liquid culture containing G-CSF. Blast cells cultured for 14 days formed many secondary cultures after replating on a methylcellulose medium. Moreover, chromosomal analyses of blasts cultivated in the presence of G-CSF for 7 days showed t(15;17) in all metaphases in one patient. It appears that the leukemic cells from APL patients could proliferate in the presence of G-CSF.

Adult↗
PubMed1988

Separation of the tumor rejection antigen of Rous sarcoma virus-induced murine fibrosarcoma.

The tumor antigen capable of inducing tumor resistance (tumor rejection antigen; TRA) was separated and some of its physicochemical properties were characterized. Cytosol and plasma membrane fractions were separated from Rous sarcoma virus (RSV)-induced CSA1M tumor cells. Immunization with membrane but not cytosol fraction of these tumor cells together with complete Freund's adjuvant resulted in complete protection against subsequent challenge with viable CSA1M cells. The TRA activity contained in the membrane fraction was recovered in the sodium dodecyl sulfate (SDS)-solubilized fraction after the SDS-extraction of CSA1M membranes. This CSA1M SDS-solubilized preparation gave protection against syngeneic RSV-induced CSA9F tumor cells as well as the homologous tumor cell type, but failed to induce resistance to RSV-unrelated tumor cells. The membrane or SDS-solubilized fraction from RSV-unrelated tumor cells was unable to generate anti-CSA1M protective immunity. Physicochemical analyses have demonstrated that TRA activity in the SDS-solubilized fraction was completely abolished by treatment with proteinase K but was only marginally affected after treatment with glycosidase mixture. When the SDS-solubilized preparation was applied to a Sephacryl S-300 superfine column, TRA activity was recovered in the range of molecular weight of 50-90 kD. Further fractionation of this TRA-positive fraction by SDS-polyacrylamide gel electrophoresis revealed that the molecular size of TRA is 56-68 kD. These results indicate that membrane proteins which were isolated from CSA1M tumor cells and have a molecular size of about 60 kD are capable of inducing RSV-induced tumor-specific in vivo protective immunity.

Animals↗
PubMed1988

Establishment of megakaryoblastic cell lines by coinfection of Abelson murine leukemia virus and recombinant SV40-retrovirus.

Murine embryonic cells including yolk sac prepared from 8-day embryos were co-infected with Abelson murine leukemia virus (A-MuLV) and/or a recombinant retrovirus containing large T and small t antigens, and early region of simian virus 40 (M-SV40). By coinfection with A-MuLV and M-SV40, megakaryoblastic cells were obtained in addition to mast cells and fibroblastic cells. However, following infection with A-MuLV or M-SV40 alone, no megakaryoblastic cells were detected, although mast cells and/or fibroblastic cells developed. The same results were obtained in several experiments. By single-cell transfer, 6 acetyl-cholinesterase (AchE)-positive clonal cell lines were established. Characteristics of megakaryocytes, such as AchE, glycoproteins IIb and IIIa, and platelet peroxidase were detected in two representative cells (C1 and C8). More significant changes expressing differentiation were observed following treatment with phorbol myristate acetate or pokeweed mitogen-stimulated murine spleen cell conditioned medium, although release of platelets was not observed. This is the first report showing development of megakaryocytic cells as the result of coinfection with retroviruses.

Abelson murine leukemia virus↗
PubMed1988

Confirmation of bone marrow engraftment by detection of M/N blood group antigens on erythroblasts in erythroid bursts.

In order to confirm erythroid engraftment, we examined the changes in blood group antigens expressed on erythroblasts in the haematopoietic colonies of a bone marrow transplant recipient. A 44-year-old female with acute myelogenous leukaemia underwent an allogeneic bone marrow transplantation from her sister donor. Prior to the transplantation, the blood groups of both recipient and donor were analysed, and their M/N groups found to differ, the former being MN and the latter N. Bone marrow mononuclear cells were obtained from the patient on day 21 after bone marrow transplantation and cultured in semi-solid medium. Erythroblasts were collected from the erythroid bursts that had formed, and were subjected to flow cytometry using monoclonal anti-M and anti-N. Anti-N reactive cells accounted for 99.2% of those in the erythroid bursts, while only 0.3% of these cells were anti-M reactive. MN type erythrocytes in the recipient's peripheral blood had been replaced by N type and only 2.0% of erythrocytes were anti-M reactive on the 70th day after BMT. These erythroblasts and erythrocytes were phenotypically N, and originated from the donor haemopoietic stem cells with the success of bone marrow engraftment. From our findings, it appears that the M/N blood group antigens were produced by the erythroid cells themselves.

Adult↗
PubMed1988

Difference of cell lineage expression of haematopoietic progenitor cells in Philadelphia-positive acute lymphoblastic leukaemia and chronic myelogenous leukaemia.

It is still difficult to clinically distinguish Philadelphia (Ph1)-positive acute lymphoblastic leukaemia (ALL) from Ph1-positive chronic myelogenous leukaemia (CML) in lymphoid crisis. In this study we tried to discriminate between these two disorders by simultaneous analyses of cell morphology and karyotype in single in vitro colonies. We studied three patients with Ph1-positive ALL and four with Ph1-positive CML in various phases of the disease. Bone marrow and peripheral blood cells obtained directly from all seven patients showed abnormal karyotypes including Ph1-chromosomes. Normal karyotypes were found in a small proportion of cells from two ALL patients, but none were found in any from the CML patients. The patients' mononuclear cells (MNCs) were plated at 1-5 x 10(4)/ml in semi-solid medium containing methylcellulose plus phytohaemagglutinin-stimulated leucocyte conditioned medium and erythropoietin. After 9-14 d cultivation, granulocyte-macrophage, erythroid and mixed colonies obtained were used for simultaneous analysis of cell morphology and karyotype. Morphological examination showed that these colonies contained neutrophils, eosinophils, basophils, macrophages and/or erythroblasts in various combinations. No lymphoblast colonies were obtained under the culture conditions used. Cytogenetic examination revealed that all metaphase cells observed in colonies obtained from Ph1-positive ALL patient MNCs had a normal karyotype, whereas those in colonies from Ph1-positive CML patient MNCs had abnormal karyotypes, including Ph1 chromosomes, suggesting that the difference between the two disorders involved a difference in cell lineage. Our results showed that this method was a practicable method for distinguishing Ph1-positive ALL from Ph1-positive CML in lymphoid crisis.

Adolescent↗
PubMed1988

Effects of corticotropin-releasing hormone and dexamethasone on proopiomelanocortin messenger RNA level in human corticotroph adenoma cells in vitro.

The effects of corticotropin-releasing hormone (CRH) and dexamethasone on proopiomelanocortin (POMC) mRNA levels in cultured pituitary adenoma cells were studied in 10 patients with Cushing's disease. As a control, POMC mRNA levels in cells from nonadenomatous tissues were examined in four patients. Human POMC mRNA in the cells was analyzed by Northern blot hybridization. Human POMC DNA probe hybridized with only a single size class of RNA (approximately 1,200 nucleotides) from the adenoma and nonadenoma cells of each patient. The size of POMC mRNA did not change through the culture or after incubation with CRH or dexamethasone. CRH increased POMC mRNA levels in these cells in a dose- and time-dependent manner. The minimum concentration of CRH required to elevate POMC mRNA levels in these cells exposed for 15 h was 0.1 nM. The minimum duration of 1 nM CRH treatment required to increase these levels was 3 h under our conditions. Inhibitory effects of 1 and 10 micrograms/dl dexamethasone on ACTH release and POMC mRNA levels in nonadenoma cells were greater than those in adenoma cells. These results suggest the following: (a) that the mRNA in cultured pituitary adenoma cells is qualitatively the same as that in vivo; (b) that responses of mRNA levels to CRH are time- and dose-dependent; and (c) that adenoma cells resist the inhibitory effect of dexamethasone on POMC mRNA levels and ACTH release.

Adenoma↗
PubMed1988

Insulin-induced hypoglycemia increases proopiomelanocortin messenger ribonucleic acid levels in rat anterior pituitary gland.

To study the effect of acute stress on ACTH secretion and synthesis in rat pituitary and hypothalamus, ACTH content and POMC mRNA levels (measured by use of Northern blot analysis) in these tissues as well as the levels of ACTH in plasma and those of CRF in the hypothalamus were determined after insulin-induced hypoglycemia. Plasma ACTH levels increased at 30 and 60 min. ACTH levels in the anterior pituitary lobe (AP) decreased at 30 min, and then returned to control levels at 60 min. No change was seen in the intermediate-posterior pituitary (IP) or the hypothalamus after insulin injection. CRF levels decreased at 30 and 60 min, then returned to control levels at 90 min in the medial basal hypothalamus, including the median eminence. Hybridization with a cDNA probe revealed a single size class of POMC mRNA in AP, IP, and hypothalamus, and the size of POMC mRNA in these tissues did not change during the experimental period. POMC mRNA levels in AP increased at 60 min and reached a peak at 120 min, but those in IP and hypothalamus did not change. These results suggest that 1) insulin-induced hypoglycemia stimulates both secretion and synthesis of ACTH (at least by increasing POMC mRNA levels) in the AP, and 2) the levels of ACTH and POMC mRNA in the IP and hypothalamus are not affected by insulin-induced hypoglycemia.

Adrenocorticotropic Hormone↗
PubMed1988

Osteoclast-like cell formation and its regulation by osteotropic hormones in mouse bone marrow cultures.

We developed a mouse bone marrow culture system to examine the process of osteoclast-like multinucleated cell formation from its progenitors. When mouse marrow cells were cultured for 8 days with 1 alpha,25-dihydroxyvitamin D3 [1 alpha,25-(OH)2D3, 10(-10) to 10(-7) M] or human PTH (1-34) (25-100 ng/ml), tartrate-resistant acid phosphatase (TRACP)-positive multinucleated cells formed. No TRACP-positive multinucleated cells appeared in the absence of these hormones. 1 alpha,25-(OH)2D3 and PTH also increased the number of the clusters of TRACP-positive mononuclear cells. Time course studies showed that these TRACP-positive mononuclear cell clusters appeared before the formation of TRACP-positive multinucleated cells, suggesting that the TRACP-positive mononuclear cells are precursors of the multinucleated cells. Salmon calcitonin markedly inhibited the formation of TRACP-positive multinucleated cells but not TRACP-positive mononuclear cell clusters induced by 1 alpha,25-(OH)2D3 or PTH. TRACP-positive mononuclear cells and multinucleated cells were rarely stained for nonspecific esterase, but some mononuclear cells were positively stained for both nonspecific esterase and TRACP. More that 90% of the TRACP-positive mononuclear cell clusters and multinucleated cells were found near colonies of alkaline phosphatase-positive mononuclear cells (possibly osteoblasts). When marrow mononuclear cells were cultured on sperm whale dentine slices in the presence of 1 alpha,25-(OH)2D3 or PTH, numerous resorption lacunae were formed. These results suggest that 1) TRACP-positive multinucleated cells formed in response to osteotropic hormones in mouse marrow cultures satisfy most of the criteria of osteoclasts, and 2) osteoblasts may play an important role in osteoclast formation.

Acid Phosphatase↗
PubMed1988

Insulin-induced hypoglycemia increases corticotropin-releasing factor messenger ribonucleic acid levels in rat hypothalamus.

To study the effect of acute stress on CRF release and synthesis in rat hypothalamus, ACTH levels in plasma, CRF contents in the median eminence (ME), and CRF mRNA levels in the hypothalamus without ME and cerebral cortex were determined after insulin-induced hypoglycemia. Plasma ACTH levels increased at 30 and 60 min, while ME CRF content decreased at 30 and 60 min, then returned to the control level at 90 min. Hybridization with a cRNA probe revealed a single size class of CRF mRNA in the hypothalamus and cerebral cortex (approximately 1300 nucleotides), and the size of CRF mRNA in these tissues did not change during the experimental period. CRF mRNA levels in the hypothalamus increased to 130% of the control value at 30 min and reached a peak (186% of the control value) at 120 min, but these levels in the cerebral cortex did not change. These results suggest that insulin-induced hypoglycemia stimulates CRF synthesis by increasing CRF mRNA levels in the hypothalamus as well as CRF release, and that release and synthesis of CRF in the cerebral cortex are independent of those in the hypothalamus.

Adrenocorticotropic Hormone↗
PubMed1988

Induction of calcitonin receptors by 1 alpha, 25-dihydroxyvitamin D3 in osteoclast-like multinucleated cells formed from mouse bone marrow cells.

We have developed a mouse marrow culture system, in which multinucleated cells (MNCs) are formed within 6-8 days. These MNCs showed several characteristics of osteoclasts, including tartrate-resistant acid phosphatase (TRACP) and the ability to resorb calcified dentine. 1 alpha, 25-Dihydroxyvitamin D3 [1 alpha, 25 (OH)2D3] stimulated the formation of TRACP-positive MNCs, and salmon calcitonin (CT) inhibited it. In this study, we examined whether the TRACP-positive MNCs formed from mouse marrow cells possess CT receptors, another typical characteristic of osteoclasts. Mouse marrow cells cultured for 8 days with 10 nM 1 alpha, 25(OH)2D3 and freshly isolated authentic mouse osteoclasts were incubated with [125I]-salmon CT in the presence or absence of excess amounts of unlabeled CT, stained for TRACP, and processed for autoradiography. The [125I]-CT exclusively bound to TRACP-positive mononuclear cells and MNCs formed in the 1 alpha, 25(OH)2D3-treated cultures and also to isolated mouse osteoclasts. Both [125I]-CT binding and TRACP activity were induced simultaneously on mononuclear cells on day 3 in the cultures treated with 1 alpha, 25(OH)2D3. CT markedly stimulated cAMP production in the 1 alpha,25(OH)2D3-treated cultures. The CT-dependent cAMP production increased in parallel with the increase in the number of TRACP-positive MNCs formed. Neither freshly isolated marrow cells nor cells cultured without 1 alpha, 25(OH)2D3 showed CT-induced cAMP accumulation. Furthermore, CT induced cytoplasmic contraction of both marrow-derived MNCs and isolated osteoclasts. These results clearly indicate that 1 alpha,25(OH)2D3 induces TRACP activity and CT receptors almost simultaneously in mouse marrow cultures, and the MNCs formed in vitro respond to CT as authentic osteoclasts do.

Animals↗
PubMed1988

Osteoblastic cells are involved in osteoclast formation.

We developed a co-culture system with mouse spleen cells and osteoblastic cells to examine the role of osteoblasts in osteoclast formation. When mouse spleen cells and osteoblastic cells isolated from fetal mouse calvariae were co-cultured in the presence of 10 nM 1 alpha, 25-dihydroxyvitamin D3 [1 alpha,25(OH)2D3], numerous tartrate-resistant acid phosphate (TRACP)-positive mononuclear and multinucleated cells were formed within 8 days. Neither the same co-cultures without the vitamin nor separate cultures of either spleen cells or osteoblastic cells with the vitamin produced TRACP-positive cells. Salmon calcitonin (CT) markedly increased cAMP production in the co-cultures treated with 1 alpha,25(OH)2D3. Autoradiographic studies clearly demonstrated that [125I]-CT specifically bound to the TRACP-positive cells formed in the co-cultures with the vitamin. When spleen cells and osteoblastic cells were co-cultured on dentine slices in the presence of 1 alpha,25(OH)2D3, numerous resorption lacunae were formed on the slices. Neither co-cultures of alveolar macrophages and osteoblastic cells nor those of spleen cells and mouse skin-derived fibroblasts induced TRACP-positive cells even in the presence of 1 alpha,25(OH)2D3. When spleen cells and osteoblastic cells were cultured separately from each other by a membrane filter (0.45 micron), no TRACP-positive cells were formed. These results indicate that osteoblastic cells are required for the differentiation of osteoclast progenitors in splenic tissues into multinucleated osteoclasts.

Acid Phosphatase↗