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T Suda

Publications and source records attributed to T Suda.

At least 739 records · Page 41Linked to original sources
PubMed1986

Synthesis of colony-stimulating factor (CSF) and differentiation-inducing factor (D-factor) by osteoblastic cells, clone MC3T3-E1.

The role of osteoblasts in inducing the proliferation and differentiation of bone marrow cells was examined. Conditioned medium obtained from mouse osteoblastic cell (MC3T3-E1) cultures stimulated colony formation of mouse bone marrow cells (CSF) and differentiation of mouse myeloid leukemia cells (M1) into macrophage-like cells (D-factor). The CSF activity increased time dependently in parallel with the increase of alkaline phosphatase activity during the culturing of the MC3T3-E1 cells. The activity of the D-factor attained a maximum on days 12 - 15 and decreased thereafter. Both the CSF and the D-factor were eluted in a range of 25,000 to 67,000 daltons on gel filtration. The fraction containing both factors exhibited bone-resorbing activity. These results suggest that osteoblasts are involved in bone resorption at least in part by enhancing the proliferation and differentiation of osteoclast progenitors.

Alkaline Phosphatase↗
PubMed1986

Polyamines are involved in the 1-alpha,25-dihydroxyvitamin D3-induced fusion of mouse alveolar macrophages.

We have reported that 1-alpha,25-dihydroxyvitamin D3 [1-alpha,25-(OH)2D3] directly induces fusion of mouse alveolar macrophages at a very high rate (circa 70-80%) by a mechanism involving protein synthesis (Proc. Natl. Acad. Sci. USA 80:5583, 1983; FEBS Letters 174:61, 1984). While examining further the mechanism of the 1-alpha,25-(OH)2D3-induced fusion of macrophages, we found that polyamines are involved in this mechanism. Mouse alveolar macrophages incubated with 12 nM 1-alpha,25-(OH)2D3 began to fuse at 36 h and the fusion rate increased linearly up to 60 h. Addition of as much as 0.05-5 mM alpha-difluoromethylornithine (alpha-DFMO), a specific inhibitor of ornithine decarboxylase, did not inhibit fusion appreciably, but addition of 0.05-5 microM methylglyoxal bis(guanylhydrazone) (MGBG), an inhibitor of S-adenosylmethionine decarboxylase, strikingly inhibited fusion. When macrophages were treated with both 12 nM 1-alpha,25-(OH)2D3 and 5 microM MGBG for the first 12 h and incubated further for 60 h in fresh medium containing 1-alpha,25-(OH)2D3, fusion was significantly inhibited, suggesting that the 1-alpha,25-(OH)2D3-induced synthesis of polyamines precedes fusion. The inhibition by MGBG of the 1-alpha,25-(OH)2D3-induced fusion was restored completely by adding 1 microM spermidine or spermine or 100 microM putrescine. None of the polyamines alone induced fusion. MGBG suppressed the 1-alpha,25-(OH)2D3-induced incorporation of [3H]-leucine into the trichloroacetic acid-insoluble fraction in macrophages, but its inhibitory effect was restored completely by adding 1 microM spermidine.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1986

Effects of retinoic acid on the activation and fusion of mouse alveolar macrophages induced by 1 alpha,25-dihydroxyvitamin D3.

1 alpha,25-dihydroxyvitamin D3 [1 alpha,25(OH)2D3] directly induces both fusion and cytotoxicity in murine alveolar macrophages. Unlike 1 alpha,25(OH)2D3, retinoic acid per se did not induce fusion of alveolar macrophages, but it greatly enhanced the 1 alpha,25(OH)2D3-induced fusion every time the macrophages were treated simultaneously with the two vitamins. The giant cells induced by the two vitamins were much larger than those induced by 1 alpha,25(OH)2D3 alone. The macrophages treated with 1 alpha,25(OH)2D3 started to fuse 36 h after the addition of the vitamin, whereas the macrophages pretreated with retinoic acid for 24 h began to fuse immediately after 1 alpha,25(OH)2D3 was added. 1 alpha,25(OH)2D3 and retinoic acid activated alveolar macrophages similarly, measured by the enhancement of glucose consumption and the induction of cytotoxicity against tumor cells, though 1 alpha,25(OH)2D3 was 100 times more potent than retinoic acid on a molar basis. Simultaneous treatment with physiological concentrations of 1 alpha,25(OH)2D3 (0.12 nM) and retinoic acid (10 nM) induced cytotoxicity additively. Morphological examinations revealed that the treated cells were enlarged and flattened with numerous filopodia. These results clearly indicate that both 1 alpha,25(OH)2D3 and retinoic acid similarly activate alveolar macrophages, and the activated state is prerequisite to the fusion of macrophages induced by 1 alpha,25(OH)2D3.

Animals↗
PubMed1986

Cell kinetic study on GM colonies using autoradiography and collagen gel culture with special reference to unique proliferation of eosinophils.

Using a newly developed technique of autoradiography and collagen gel culture, a kinetic study on human GM colonies was attempted. Colonies of immature cells appeared first on day 5. The number of mixed colonies (mixture of immature cells, neutrophils, and/or monocyte-macrophages) and neutrophil colonies attained a maximum on days 8 to 10 and a broad peak of monocyte-macrophage colonies was observed on days 11 to 16. Eosinophil colonies appeared first on day 12, reached a maximum on day 18, and then gradually decreased. A detailed analysis of the order of appearance of the colonies suggests that mixed, neutrophil and monocyte-macrophage colonies originate from immature cell colonies or clusters, while eosinophil colonies do not. An autoradiographic study was designed to study the proliferation characteristics of each colony. Labeling indices (LI) with 3H-TdR of the cells in immature cell colonies were always high. LI of the cells in differentiated colonies such as neutrophil, monocyte-macrophage, and mixed colonies were low throughout the observation period. In contrast, LI of the cells in eosinophil colonies were constantly high regardless of the size of cell aggregates and the duration of the culture period. Both mitotic indices and mean grain counts on the nuclei of eosinophils were similar to those of immature cells. These results suggest that eosinophil colonies develop from their own small clusters and that eosinophils retain a fairly good proliferative capacity even when differentiated to the level in which specific granules appear in the cytoplasm.

Autoradiography↗
PubMed1986

Isolation and physiological action of capillary permeability increasing-enzyme from the venom of Agkistrodon caliginosus.

A purified capillary permeability increasing-enzyme was obtained from Agkistrodon caliginosus venom by modification of our previous purification method. The purified enzyme, which had arginine esterase activity and strong capillary permeability increasing-activity, did not show caseinolytic, clotting or bradykinin-releasing activities. These properties of the enzyme were almost the same as those of the enzyme obtained by the previous purification method. When a mixture of the purified enzyme and bovine plasma or heated bovine plasma was injected into depilated skin on the back of a rabbit, the capillary permeability increasing-activity was much greater than that induced by injection of the enzyme alone. The substance which increases the capillary permeability was extracted from the incubated mixture of bovine plasma and the enzyme with 50-70% ethanol. Its activity was lost on treatment with carboxypeptidase A. From these results, it is supposed that the increase in capillary permeability induced by the enzyme is due to a low molecular weight peptide released from a protein in bovine plasma by the proteolytic action of the enzyme.

Animals↗
PubMed1986

Bone in the marmoset: a resemblance to vitamin D-dependent rickets, type II.

The common marmoset, a New World monkey, requires a large amount of vitamin D3 to maintain its normal growth. This monkey is reported to have an end-organ resistance to 1 alpha,25-dihydroxyvitamin D3 (1 alpha,25(OH)2D3). In this study, the bone morphology of marmosets fed a high vitamin D3 diet (intake of vitamin D3, 110 IU/day/100 g of body weight) was compared by X-ray and histological examinations with that of rhesus monkeys (Old World monkey) fed a normal diet (intake of vitamin D3, 5 IU/day/100 g of body weight). Three of 20 marmosets were found by X-ray examination to have osteomalacic changes in their bones despite the high daily intake of vitamin D3, whereas none of the 5 rhesus monkeys showed any signs of osteomalacia. Osteomalacic marmosets had distinct increases in osteoid surface, relative osteoid volume, and active osteoclastic bone resorption, whereas non-osteomalacic marmosets had no increase in osteoid tissues in their bones. None of the marmosets, either osteomalacic or non-osteomalacic, was hypercalcemic despite the extremely high circulating levels of 1 alpha,25(OH)2D3. However, the serum 25-hydroxyvitamin D3 (25OHD3) and 24R,25-dihydroxyvitamin D3 (24R,25(OH)2D3) levels were significantly lower in the osteomalacic than in the non-osteomalacic marmosets. These results suggest that the marmoset is likely to exhibit osteomalacic bone changes despite the high daily intake of vitamin D3. These changes resemble those in vitamin D-dependent rickets, type II.

24,25-Dihydroxyvitamin D 3↗
PubMed1986

Comparison of the mechanisms of bone resorption induced by 1 alpha,25-dihydroxyvitamin D3 and lipopolysaccharides.

The mechanisms of increase in bone resorption induced by 1 alpha,25-dihydroxyvitamin D3 [1 alpha,25(OH)2D3] and bacterial lipopolysaccharides (LPS) were compared in an in vitro dead bone assay and a living bone assay. 1 alpha,25(OH)2D3 at concentrations of 0.05-5 ng/ml dose-dependently enhanced the ability of alveolar macrophages to release 45Ca from prelabeled dead bone particles (dead bone assay). In addition, the vitamin promoted fusion of the macrophages to form multinucleated cells and also enhanced glucose consumption, a marker of activation of macrophages. LPS at 0.05-5 micrograms/ml similarly enhanced the release of 45Ca from the dead bone particles and glucose consumption by alveolar macrophages, but it did not induce fusion of the cells at any concentration. Both 1 alpha,25(OH)2D3 and LPS dose-dependently stimulated the release of 45Ca from fetal mouse calvaria prelabeled with 45Ca (living bone assay). Compared to control bone, there were several times as many osteoclasts per given length of trabecular bone surface in calvaria treated for 5 days with either 5 ng/ml of 1 alpha,25(OH)2D3 or 5 micrograms/ml of LPS. Indomethacin (10(-5) M) completely inhibited the LPD-induced increase of osteoclasts, but not the 1 alpha,25(OH)2D3-induced increase. These results suggest that 1 alpha,25(OH)2D3 and LPS similarly stimulate bone resorption by activating macrophages as well as by promoting fusion of precursor cells to form multinucleated cells. 1 alpha,25(OH)2D3 induced formation of multinucleated cells with bone-resorbing activity directly, whereas LPS appeared to induce multinucleated cells through prostaglandin synthesis by some other types of cells present in living bone tissues.

Animals↗
PubMed1986

Overproduction of proteins encoded by lambda replicon-integrated plasmid: effect of partial inactivation of cI repressor.

Composite plasmids containing the 7.2-kb fragment of bacteriophage lambda cI857cro27, essential for lambda DNA replication and its control, have been constructed. The plasmids contained, in addition, pBR322, a part of Co1E1, and the Escherichia coli pss gene, coding for phosphatidylserine synthase. When the plasmid-harboring cells were induced at different temperatures, the phosphatidylserine synthase production was maximum at 37 degrees C, and the specific activities at 37 degrees C continuously increased until the culture reached saturation. The results suggest that, when the cro gene is defective, only a transient temperature for inactivation of cI repressor provides both the increase in copy number of the plasmids and cellular activities that allow overproduction of the plasmid-encoded protein.

Bacteriophage lambda↗
PubMed1986

Inhibitory effect of 1 alpha,25-dihydroxyvitamin D3 on the growth of the renal carcinoma cell line.

We studied the effect of vitamin D compounds on the growth of the human renal carcinoma cell line (KU-2) and discovered a receptor protein specific for the active form of vitamin D3, 1 alpha,25-dihydroxyvitamin D3. The KU-2 cell line was established from a pulmonary metastasis of renal cell carcinoma in a patient with hyperhemoglobinemia. The cells were tumorigenic in nude mice and clonogenic in a soft agar culture. Vitamin D3 derivatives suppressed proliferation of KU-2 cells in a monolayer culture and also clonogenicity in a soft agar culture dose-dependently. Of the vitamin D3 derivatives tested, 1 alpha,25-dihydroxyvitamin D3 was the most potent in inhibiting cell growth, followed successively by 1 alpha,24R,25-trihydroxyvitamin D3, 25-hydroxyvitamin D3, 1 alpha-hydroxyvitamin D3 and 24R,25-dihydroxyvitamin D3 in that order. Analysis of the cell cycle phase of treated and non-treated KU-2 cells revealed that the action of 1 alpha,25-dihydroxyvitamin D3 was not phase-specific but simply extended the doubling time of the cells. Radioreceptor assay and sucrose density gradient analysis of the cytosol showed that KU-2 cells contained a 3.2S receptor protein to which 1 alpha,25-dihydroxyvitamin D3 was specifically bound (Kd = 20.8 +/- 4.8 pM, Nmax = 87 +/- 24 fmole/mg protein, 4000 molecules/cell). On the other hand, the equilibrium dissociation constant of internalization of 1 alpha,25-dihydroxyvitamin D3 (Kint) by intact KU-2 cells was 1.2 nM and the internalizing capacity was 33 fmole/8 X 10(6) cells (2500 molecules/cell) in the 10% serum medium, which was the same as that used in the growth study.(ABSTRACT TRUNCATED AT 250 WORDS)

Calcitriol↗
PubMed1986

Differentiation-inducing factor purified from conditioned medium of mitogen-treated spleen cell cultures stimulates bone resorption.

Spleen cells treated with mitogens produce a potent bone-resorbing factor called osteoclast-activating factor (OAF). To examine the relationship between the bone-resorbing factor and other protein factors produced by spleen cells, the colony-stimulating factor (CSF), the differentiation-inducing factor (DIF), the macrophage fusion factor (MFF), and the macrophage growth factor (MGF) were purified from 2.68 liters of conditioned medium of mouse spleen cell cultures treated with concanavalin A. Purification was performed successively by DEAE-cellulose, Blue Sepharose, and Sephadex G-150 column chromatography and high-pressure liquid chromatography (HPLC). The DIF was successfully separated from CSF and MGF on HPLC. CSF coincided with MGF on HPLC, but MFF disappeared before application to HPLC. Only the DIF exhibited bone-resorbing activity, whereas CSF and MGF did not. The DIFs purified from L929 cells and Ehrlich ascites tumors similarly exhibited bone-resorbing activity. The DIFs purified from spleen cells and Ehrlich ascites tumor cells exhibited neither interleukin 1 (IL-1) activity nor tumor necrosis factor (TNF) activity, though the unfractionated conditioned medium from spleen cells did exhibit them. In the light of recent reports that IL-1 beta and TNF also stimulate bone resorption, the term OAF should refer to a generic activity rather than a single factor.

Animals↗
PubMed1986

Myeloid and erythroid lineage expression of haemopoietic progenitors derived from an abnormal clone in erythroleukaemia.

To clarify the lineage involvement of haemopoietic progenitor cells in erythroleukaemia, the morphology and chromosomes of single colonies from a patient with erythroleukaemia were analysed simultaneously. The cytogenetic analysis of bone marrow cells revealed two clones; 44,XY,-7,-12,-17, del (5)(q31), +Mar and 43,XY,-7,-12,-17,-19,del(5)(q31),+Mar. Of 40 metaphases examined, there were 34 and six of these clones, respectively. Bone marrow mononuclear cells were plated at 5 X 10(4)/ml in methylcellulose medium containing phytohaemagglutinin-stimulated leucocyte conditioned medium and erythropoietin. Seventeen colonies, i.e. nine blast cell colonies, four myeloid (Sudan black B-positive) colonies, and four erythroid (benzidine-positive) colonies contained analysable metaphases, yielding 102 metaphases in total. Except for chromosome random loss, the karyotype within a colony remained constant. All three types of colonies showed an abnormal clone; 44,XY,-7,-12,-17,del(5)(q31),+Mar. From these findings, it is concluded that myeloid and erythroid lineages in erythroleukaemia were derived from the same abnormal clone.

Aged↗
PubMed1986

Multilineage expression of haemopoietic precursors with an abnormal clone in idiopathic myelofibrosis.

To clarify the lineage involvement of haemopoietic progenitor cells in idiopathic myelofibrosis (MF), simultaneous analysis of morphology and chromosomes were performed on single colonies from a 70-year-old Japanese woman with typical presentation of MF. The cytogenetic analysis of unstimulated peripheral blood cells revealed three cell lines 47,XX,-6,+9,+der(6)t (1;6)(1qter----1q21::6p21----6qter), 46,XX,-6,+der(6) and 46,XX. Of 91 metaphases examined, the numbers of each cell line were 43, 41 and 7, respectively. Blood mononuclear cells were plated at 2 X 10(3) or 1 X 10(4)/ml in methylcellulose medium containing phytohaemagglutinin-stimulated leucocyte conditioned medium and erythropoietin. On days 10, 12 and 14 of culture, 47 individual colonies were lifted and served for morphological and cytogenetic examination. Morphological examination revealed that the colonies contained neutrophils (n), macrophages (m), basophils (b), erythrocytes (E) and megakaryocytes (M). Twenty-two of the 47 colonies had analysable metaphases, yielding totally 158 metaphases. Twelve colonies contained three or more metaphases. Eight colonies (3bE, 1E, 2b, 1nEM, 1bEM) were of the abnormal cell line 46,XX,-6,+der(6), and four colonies (2E, 1bE, 1mE) were of the karyotypically normal cell line 46,XX. The other abnormal cell line 47,XX,-6,+9,+der(6) was not detected in any of the metaphases obtained from single colonies. These results provided direct evidence that the pluripotent stem cells were involved in MF.

Aged↗
PubMed1986

Megakaryocytopoiesis in vitro of patients with essential thrombocythaemia: effect of plasma and serum on megakaryocytic colony formation.

To clarify the mechanism of increased numbers of megakaryocytes in patients with essential thrombocythaemia (ET), we studied in vitro megakaryocytopoiesis in ET and other myeloproliferative disorders, using a megakaryocytic colony assay in methylcellulose containing plasma or serum and medium conditioned by phytohaemagglutinin (PHA) stimulated leucocytes (PHA-LCM). Megakaryocytic colony formation was supported well by heparinized or citrated plasma and citrated serum which was harvested after clot formation of citrated plasma. Whole serum was inhibitory for megakaryocytic colony growth. The addition of platelet releasates and partially purified platelet derived growth factor (PDGF) resulted in a decrease in the number of megakaryocytic colonies. These findings suggested that platelet-derived factor(s) in serum was inhibitory to megakaryocytic colony formation. ET plasma supported the megakaryocytic colony formation by normal or ET bone marrow cells better than normal plasma. Moreover, in ET bone marrow cells, spontaneous megakaryocytic colonies were formed in the absence of PHA-LCM. Increased megakaryocytopoiesis in ET may be ascribed to (i) increased megakaryocyte-colony stimulating activity (Meg-CSA) in plasma and (ii) increased sensitivity to Meg-CSA or autonomous proliferation of megakaryocytic progenitor cells.

Adult↗
PubMed1986

Photokeratoscopy in fitting contact lens after penetrating keratoplasty.

The formula based on keratometric readings which is generally used is unsatisfactory for fitting contact lenses after penetrating keratoplasty, possibly owing to lack of information on the peripheral corneal toricity. In these studies a photokeratoscope was used to examine the entire graft topography. In all cases the corneal configuration became more normal after suture removal, but a considerable toricity still remained, especially near the graft-host junction. One month after removal of sutures spherical hard contact lenses (polymethylmethacrylate, PMMA) were fitted to 30 patients in accordance with data obtained by computerised analysis of the photokeratograms. Of the 30 patients (contact lens wearers) 27 (90%) obtained a stable vision of better than 20/30 for eight hours daily, and 24 (80%) achieved a stable vision of 20/20 for their full waking hours. After one year the contact lens wearers showed a significant decrease in the extent of astigmatism when compared with the non-contact-lens wearers (10 patients). These results suggest that the photokeratoscope can be more useful than ordinary keratometers in fitting contact lenses after keratoplasty, and that hard contact lenses have moulding effects on the graft topography.

Adolescent↗
PubMed1986

Inhibitory effect of adrenocorticotropin on corticotropin- releasing factor release from rat hypothalamus in vitro.

Effects of ACTH and ACTH fragments on immunoreactive corticotropin-releasing factor (I-CRF) release were examined by utilizing rat hypothalamic perifusion system and a rat CRF RIA. ACTH-(1-39) had a dose-related inhibitory effect on I-CRF release. Mean percent inhibition of I-CRF release was 52, 55, 49, 30 and less than 5 percent by ACTH-(1-39), ACTH-(1-24), alpha-MSH and ACTH-(18-39) at 2.2 nM concentrations, respectively. These results suggest the presence of a negative short-loop feedback mechanism, and also that the active core is contained within the ACTH-(1-17) structure.

Adrenocorticotropic Hormone↗
PubMed1986

Human parathyroid hormone inhibits renal 24-hydroxylase activity of 25-hydroxyvitamin D3 by a mechanism involving adenosine 3',5'-monophosphate in rats.

The in vivo effect of PTH on renal 24-hydroxylase activity of 25-hydroxyvitamin D3 (25OHD3) was examined in vitamin D-deficient thyroparathyroidectomized rats by a recently developed sensitive in vitro assay of 25OHD3-hydroxylases using rat kidney homogenates and by an in vivo assay measuring the accumulation of tritiated metabolites in plasma 5 h after injection of 25OH[3H]D3. Infusion for 20 h of either human PTH-(1-34) (except at 800 pmol/h) or cAMP did not significantly change the plasma levels of calcium and phosphorus compared with those in thyroparathyroidectomized rats given 125 ng 1,25-dihydroxyvitamin D3 to induce renal 24-hydroxylase activity. On the other hand, human PTH-(1-34) markedly inhibited renal 24-hydroxylase activity and stimulated 1-hydroxylase activity. The effective concentration of human PTH-(1-34) was much lower for inhibiting 24-hydroxylase than for stimulating 1-hydroxylase activity. Infusion of less than 100 nmol/h cAMP similarly inhibited 24-hydroxylase activity without enhancing 1-hydroxylase activity. Either theophylline (1.0 mumol/h) or a submaximal dose (25 pmol/h) of human PTH-(1-34) alone inhibited 24-hydroxylase activity only slightly, but the concomitant infusion of both chemicals markedly inhibited 24-hydroxylase activity without stimulating 1-hydroxylase activity. These effects of human PTH-(1-34) and cAMP occurred similarly in both the in vitro and the in vivo assays. The present study clearly indicates that besides its well known action in stimulating 1-hydroxylase activity, PTH inhibits renal 25OHD3-24-hydroxylase activity by a mechanism involving cAMP.

24,25-Dihydroxyvitamin D 3↗
PubMed1986

Ectopic adrenocorticotropin syndrome caused by lung cancer that responded to corticotropin-releasing hormone.

ACTH responses to corticotropin-releasing hormone (CRH) were studied in three patients with the ectopic ACTH syndrome caused by lung cancer. Plasma ACTH responded to synthetic CRH in two of three patients. Tumor tissues obtained from these two patients contained CRH and ACTH. In one patient, tumor ACTH secretion was stimulated by CRH in vitro. Tumor CRH was immunologically, chromatographically, and biologically similar to hypothalamic CRH. In addition, multiple forms of immunoreactive beta-endorphin were present in plasma and the tumor extracts. From these results, we conclude that some patients with the ectopic ACTH syndrome have tumors that produce both ACTH and CRH and that CRH can stimulate ACTH secretion by such tumors. Other patients with the ectopic ACTH syndrome do not have ACTH responses to CRH. Therefore, procedures other than CRH testing are needed to differentiate patients with Cushing's syndrome due to ectopic ACTH/CRH production from those with Cushing's disease, since the latter also usually have ACTH responses to CRH.

ACTH Syndrome, Ectopic↗