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Biomedical subjects

J Nishimura

Publications and source records attributed to J Nishimura.

At least 307 records · Page 17Linked to original sources
PubMed1987

Effect of guanosine triphosphate on the release of Ca2+ from intracellular store sites of saponin-treated human peripheral lymphocytes.

The effects of guanosine triphosphate (GTP) on the release and uptake of Ca2+ in nonmitochondrial intracellular store sites of human peripheral lymphocytes were examined. GTP in the presence of 3% polyethylene glycol released Ca2+ from the intracellular store sites of lymphocytes in a dose-dependent manner, and the maximal release was obtained at 10 microM GTP. GDP and 5'-GMP also enhanced the release of Ca2+. On the other hand, Ca2+ uptake in the presence of oxalate by saponin-treated lymphocytes was stimulated by GTP and this stimulation was abolished when polyethylene glycol was concomitantly present. The dose dependence of the stimulated Ca2+ uptake by GTP was much the same as that of the Ca2+ released by GTP. These results indicate that GTP has an inherent activity to release Ca2+ as well as to stimulate the uptake of Ca2+ in nonmitochondrial intracellular store sites of saponin-treated lymphocytes. The stimulatory effect of polyethylene glycol on GTP-mediated Ca2+ release may occur by inhibiting functions of the Ca2+ pump.

Biological Transport, Active↗
PubMed1987

A stimulator of mouse stem cell proliferation produced by human regenerating bone marrow.

We examined CFU-S proliferation stimulator, which recruits stem cells in DNA synthesis, in conditioned media prepared from bone marrow cells of patients with regeneration hemopoiesis after chemotherapy induced hypoplasia. This activity was estimated by hydroxyurea sensitivity of CFU-S in mice, under conditions of incubation with human bone marrow conditioned medium (BMCM). We found that CFU-S proliferation stimulator was present to a considerable extent in human regenerating BMCM, but less so in normal BMCM and that the production fluctuated with change of hemopoietic states, in the same patient. This stimulator was heat-labile, trypsin-sensitive and mainly produced by adherent cells. This factor may possibly be involved in regulation of proliferation of stem cells in regenerating bone marrow in humans.

Animals↗
PubMed1987

Pancreatic carcinoma associated with marked eosinophilia: a case report.

A case of pancreatic carcinoma associated with marked eosinophilia is reported. A 71-yr-old man was admitted to hospital because of melena and abdominal pain. The systematic examinations revealed pancreatic adenocarcinoma with multiple metastases (rectum, lung and brain). The leukocyte count was gradually increased and reached up to 81.7 X 10(9)/l, of which 54% consisted of eosinophils. Colony-stimulating factor (CSF) was detected both in the patient's serum and in the tumor extracts by a normal human bone marrow culture system. The colonies which were stimulated with patient's serum largely consisted of granulocyte, granulocyte/macrophage and eosinophil types. These results suggest that blood leukocytosis and eosinophilia were due to a high concentration of plasma CSF, which was probably produced by the tumor cells.

Adenocarcinoma↗
PubMed1987

Characteristics of adrenoceptors and [3H]nitrendipine receptors of porcine vascular smooth muscle: differences between coronary artery and aorta.

Characteristics of the bindings of [3H](-)dihydroalprenolol, [125I](-)iodocyanopindolol, [3H]prazosin, [3H]yohimbine, and [3H]nitrendipine to porcine coronary membranes were investigated and the results compared with studies of porcine aortic membranes. In the equilibrium binding study carried out in sarcolemma-enriched fractions, there were no major differences in the Kd values of these radioligands between coronary artery and aorta. However, the densities of beta-, alpha 1-, and alpha 2-adrenoceptors and [3H]nitrendipine receptors of coronary artery were 258, 12, 12, and 561 fmol/mg protein, respectively, while those of aorta were 37, 525, 1,000, and 215 fmol/mg protein. beta-Adrenergic agonists competed with [3H](-)dihydroalprenolol binding sites in coronary artery, the order of potency being (-)isoproterenol greater than (-)norepinephrine greater than (-)epinephrine greater than (+)isoproterenol. In case of aorta, the order was (-)isoproterenol greater than (-)epinephrine greater than (-)norepinephrine. The competition by (+/-)bisoprolol (beta 1-selective antagonist) and ICI 118,551 (beta 2-selective antagonist) for [125I](-)iodocyanopindolol binding sites in coronary artery resulted in nonlinear Hofstee plots (beta 1:beta 2 = 90%:10%). In case of aorta, linear Hofstee plots were obtained. From these results, we conclude that coronary beta-receptors in pigs are predominantly of beta 1-type, while those of aorta are of beta 2-type; regarding the relative population of adrenoceptors, coronary artery is beta-dominant (beta/alpha = 11), while aorta is alpha-dominant (beta/alpha = 0.02); compared with alpha-adrenoceptors, coronary artery has a greater number of [3H]nitrendipine binding sites (nitrendipine/alpha-adrenoceptor = 23) than aorta (nitrendipine/alpha-adrenoceptor = 0.14).

Animals↗
PubMed1987

[Conversion of 5'-deoxy-5-fluorouridine to 5-FU by pyrimidine nucleoside phosphorylases in normal and tumor tissues from rodents bearing tumors and cancer patients].

Enzyme levels of pyrimidine nucleoside phosphorylase, which is an essential enzyme for the phosphorolysis of 5'-deoxy-5-fluorouridine (5'-DFUR) to 5-fluorouracil (5-FU), in normal and tumor tissues were investigated. In all mouse strains tested, the enzyme level was found to be higher in the small intestine and stomach than other tissues, while in rats a higher level of the enzyme in the lung was also observed additionally. The enzyme levels of tumor tissues varied in tumor cell lines transplanted. P388 leukemia, Ehrlich ascites carcinoma, sarcoma 180, colon 26 carcinoma, and Lewis lung carcinoma cells contained high levels of the enzyme and the mice bearing these tumors responded well to the therapy with 5'-DFUR than its active metabolite 5-FU, while 5'-DFUR did not show clear advantage over 5-FU against L1210 or LSTRA leukemia, in which the enzyme levels were low. These results indicate that there is some correlation between the enzyme level and antitumor efficacy of 5'-DFUR. In human specimens, the enzyme levels were 2-6 times higher in tumors than those of the corresponding normal tissues and those adjacent to the tumors. These results predict that 5'-DFUR seemed to be converted efficiently to 5-FU also in human tumors.

Animals↗
PubMed1987

Regulatory roles of burst-promoting activity (BPA) from bone marrow cells during human regenerating hemopoiesis.

To clarify the regulatory roles of burst-promoting activity (BPA) in cases of in vivo erythropoiesis, we examined erythroid progenitors and BPA in 18 patients with a regenerating hemopoiesis following intensive chemotherapy. Marrow erythroid progenitors increased remarkably in these patients. Bone marrow-conditioned medium (BMCM) and sera obtained from these patients revealed high levels of BPA. Serial examination of a typical case showed that BPA in BMCM and sera increased during regenerating hemopoiesis, but decreased when the hemopoiesis stabilized. Adherent cell depletion and treatment with monoclonal antibody (OKM1) reduced BPA production from the bone marrow cells, thereby suggesting that bone marrow macrophages are responsible for the BPA production. Fractionation of pooled BMCM with Amicon Diaflo membranes showed that the BPA was mainly present in the 30,000- to 50,000-dalton fraction. BPA in BMCM was heat labile, inactivated by trypsin and protease, but was not inactivated by neuraminidase. Pooled BMCM did not influence the growth of CFU-E-derived colonies. Our results suggest that to repair disturbed erythropoiesis, bone marrow macrophages produce BPA during regenerating hemopoiesis.

Adult↗
PubMed1986

Expression of c-myc oncogene during differentiation of human burst-forming unit, erythroid (BFU-E).

We investigated the serial expression of c-myc oncogene during differentiation of normal human burst-forming unit, erythroid (BFU-E), in vitro, together with the replating efficiency and the expression of transferrin receptors. We found that the c-myc oncogene was expressed in the early progeny of BFU-E and that this expression decreased during erythroid differentiation. This change of the c-myc expression was well correlated to changes in the replating efficiency and the expression of transferrin receptors. These observations indicate that the c-myc oncogene probably has a physiological role in normal human hematopoiesis as well as leukemic hematopoiesis.

Cell Differentiation↗
PubMed1986

Intracellular free calcium transients induced by norepinephrine in rat aortic smooth muscle cells in primary culture.

In cultured rat arterial smooth muscle cells treated with quin 2, cytosolic Ca2+ transients induced by norepinephrine were recorded microfluorometrically. In the presence or absence of extracellular Ca2+, norepinephrine induced transient and dose-dependent elevations in cytosolic Ca2+, with a similar time course, the peak levels being observed at 2 min. These transient elevations in cytosolic Ca2+ were dose-dependently inhibited by alpha-adrenergic antagonists, the order of potency being prazosin greater than phentolamine greater than yohimbine, irrespective of the presence of extracellular Ca2+. We propose that with or without extracellular Ca2+, norepinephrine activates mainly alpha-1 adrenoceptors leading to a release of Ca2+ from intracellular stores. This would explain the transient elevation in cytosolic Ca2+ in rat aortic vascular smooth muscle cells in primary culture.

Aminoquinolines↗
PubMed1986

Histamine activates H1-receptors to induce cytosolic free calcium transients in cultured vascular smooth muscle cells from rat aorta.

Using an intracellularly trapped dye, quin 2, the effects of histamine on cytosolic free calcium concentrations in rat aortic vascular smooth muscle cells in primary culture were recorded, microfluorometrically. When the cells were exposed to histamine, both in the presence and the absence of extracellular Ca2+, there was a rapid, transient and dose-dependent elevation of cytosolic Ca2+ concentrations, with a similar time course. This elevation of cytosolic Ca2+ was dose-dependently inhibited by mepyramine, but not by cimetidine. Thus, histamine activates H1- but not H2- receptors to mediate a release of Ca2+ from the store sites, and there is a rapid and transient elevation of cytosolic Ca2+.

Aminoquinolines↗
PubMed1986

Clinical significance of human bone marrow stromal cell colonies in acute leukemias.

Human bone marrow-derived fibroblastoid colony-forming cells (CFU-F) and adipocyte colonies in 36 patients with acute leukemia were studied, and were serially analysed at different clinical stages. At untreated stage, CFU-F number in acute lymphoblastic leukemia (ALL) was lower than that in acute non-lymphoblastic leukemia (ANL). In ANLs, CFU-F number in M1 was lower than that in M2. Adipocyte colonies were frequently developed at regenerating and relapsing stages, but rarely at untreated and remission stages. The adipocyte colony formation did not correlate with any of CFU-F number, marrow cellularity nor number of leukemic cells, but might be associated with hemopoietic regeneration. The favorable prognosis was associated with normal CFU-F number and with adipocyte colony formation at regenerating or bottom stage. As adipocytes in marrow samples were completely removed before cultures, adipocyte colony was probably originated from preadipocytes. Thus, our results suggest that adipocyte precursor cells increase in regenerating marrow and that they are essential in active hemopoiesis.

Acute Disease↗
PubMed1986

Serial studies of bone marrow-derived fibroblastoid colony-forming cells and granulocyte/macrophage precursor cells in patients with acute leukemia.

Bone marrow-derived fibroblastoid colony-forming cells (CFU-F) and granulocyte/macrophage precursor cells (CFU-GM) were studied in patients with acute leukemia. The numbers of CFU-F and CFU-GM were significantly lower in patients with acute myelogenous leukemia (AML) and acute lymphocytic leukemia (ALL) at diagnosis than in normal subjects, although patients with AML had a very wide range of CFU-F colony-forming efficiency. However, a suppressive effect of leukemic cells on normal CFU-F colony formation was not observed. CFU-F and CFU-GM in patients with acute leukemia recovered to normal levels when complete remission (CR) was achieved and decreased again at relapse. Serial studies showed that the increase in CFU-F preceded the recovery of CFU-GM. In AML, furthermore, patients who achieved CR had a higher number of CFU-F than patients without CR, suggesting that the CFU-F level at diagnosis may contribute to the prediction of the likelihood of remission induction in patients with AML.

Adult↗
PubMed1986

Periodical appearance of erythropoietin-independent erythropoiesis in chronic myelogenous leukemia with cyclic oscillation.

A patient with Ph1-positive chronic myelogenous leukemia (chronic phase) had a cyclic oscillation in white blood cells, platelets and percent saturation of transferrin. The cycle comprised about 70 days. The number of circulating granulocyte-macrophage colony-forming units (CFU-GM) oscillated with the same phase, while that of bone marrow CFU-GM and erythroid colony-forming units (CFU-E) oscillated in a reverse phase. At the nadir, we observed an abnormal increase in bone marrow endogenous CFU-E (e-CFU-E). An erythropoietin (Epo) dose-response curve of CFU-E showed a high Epo-sensitivity. Anti-Epo rabbit serum did not inhibit the e-CFU-E colony formation. This indicates that Epo-independent erythropoiesis occurs periodically at the nadir. It is suggested that the interactions between the abnormal stem cell and the hematopoietic regulating system cause cyclic oscillation.

Adult↗