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M Harada

Publications and source records attributed to M Harada.

At least 883 records · Page 49Linked to original sources
PubMed1990

Pharmacological studies on novel muscarinic agonists, 1-oxa-8-azaspiro[4.5]decane derivatives, YM796 and YM954.

We have investigated the pharmacological profiles of the novel muscarinic agonists, 1-oxa-8-azaspiro[4.5]decane derivatives, YM796 (2,8-dimethyl-3-methylene) and YM954 (2-ethyl-8-methyl-3-oxo). These compounds, like the putative M1 agonists, RS86 and AF102B, inhibited [3H]pirenzepine binding to cerebral cortical membranes in the micromolar range and weakly inhibited [3H]quinuclidinyl benzylate binding to cerebellar membranes. Their (-) isomers had Hill coefficients lower than 1.0. (+/-)-YM796, (+/-)-YM954 and RS86, but not AF102B, stimulated phosphoinositide hydrolysis in hippocampal slices, an effect which is mainly linked to M1 receptors. (+/-)-YM796 (0.031 mg/kg p.o.) and (+/-)-YM954 (0.016 mg/kg p.o.) reversed the cognitive impairment in nucleus basalis magnocellularis-lesioned rats in a passive avoidance task more effectively than did RS86 and AF102B. Similar results were obtained in scopolamine-treated rats. Finally, (+/-)-YM796 was weaker than (+/-)-YM954 and RS86 in the induction of tremor, hypothermia and contraction of isolated ileum, which are mainly mediated by M2 and/or M3 receptors. These results suggest that (+/-)-YM796, (+/-)-YM954 and RS86 have M1 agonistic activity in central nervous system and that (+/-)-YM796 has relatively weak M2 and/or M3 agonistic activity.

Animals↗
PubMed1990

Activation of propylbenzilylcholine mustard-sensitive muscarinic cholinoceptors more effectively utilizes cytosolic Ca2+ for contraction in guinea-pig intestinal smooth muscle.

A 50-min treatment of longitudinal smooth muscle of guinea-pig ileum with propylbenzilylcholine mustard (PrBCM, 3 x 10(-6) M) irreversibly inhibited the responses elicited by carbachol. However, a 90-min treatment with PrBCM had no further significant inhibitory effect on the responses to carbachol, suggesting that there are two subtypes of muscarinic cholinoceptors, PrBCM-sensitive and PrBCM-insensitive receptors. Carbachol caused a rapid increase in cytosolic Ca2+ concentrations ([Ca2+]i), which was followed by a rapid increase in muscle tension in both untreated and PrBCM-treated preparations. There was a positive correlation between [Ca2+]i (R340/380) and tension developed in response to carbachol. A regression line for the two responses was obtained in each preparation. The slope of the line obtained with untreated preparations was steeper than that obtained with PrBCM-treated preparations. These data suggest that, upon activation, PrBCM-sensitive receptors use cytosolic Ca2+ more effectively than PrBCM-insensitive receptors.

Animals↗
PubMed1990

The alpha 1 beta 1 heterodimer of ATP synthase.

The alpha 3 beta 3 hexamer was reconstituted from the alpha and beta subunits of TF1 portion of ATP synthase of thermophilic bacterium (Kagawa et al. (1989) FEBS Lett. 249, 67). The alpha 1 beta 1 heterodimer of ATP synthase was isolated by high performance liquid chromatography (HPLC) of the alpha 3 beta 3 hexamer in the presence of AT(D)P-Mg. On polyacrylamide gel electrophoresis, both bands corresponding to the dimer and hexamer showed ATPase activity. The alpha 1 beta 1 dimer was dissociated into the equal amounts of the alpha and beta monomers by sodium dodecyl sulfate. The alpha and beta monomers were practically inactive. The alpha 2 and beta 2 homodimers were not detected by electrophoresis and HPLC.

Bacteria↗
PubMed1990

S-phase fraction of human prostate adenocarcinoma studied with in vivo bromodeoxyuridine labeling.

Forty-six patients with adenocarcinoma of the prostate were given an intravenous infusion of the thymidine analogue, bromodeoxyuridine (BrdU), 200 mg/m2, at the time of needle biopsy or transurethral resection to label tumor cells in the DNA synthesis phase. The tumor specimens were stained by an indirect immunoperoxidase method with anti-BrdU monoclonal antibody. The BrdU labeling index, S-phase fraction, was determined by counting the number of BrdU-labeled cells in the tissue sections. S-phase fraction correlates with the results of histologic tumor grade, Gleason score, and growth patterns. The higher S-phase fraction may indicate biologic malignancy. Moreover, the degree of heterogeneity concerning S-phase fraction distribution within prostate cancer tissue could be evaluated and the findings compared with the morphologic appearance. The authors results suggest that the measurement of BrdU labeling index in prostate cancer may prove to be a new objective and quantitative assay for biologic potential of individual tumors.

Adenocarcinoma↗
PubMed1990

Right-left asymmetry of tyrosine hydroxylase in rat median eminence: influence of arterial baroreflex nerves.

Arterial baroreceptor nerves consist of 2 pairs of nerves, carotid sinus and aortic. The latter nerves differ bilaterally as to size and origin suggesting that central baroreceptor activity could be asymmetrical. This was tested by studying activity of tyrosine hydroxylase (TH), the rate limiting enzyme for catecholamine synthesis, on right and left sides of the brain in median eminence (ME), arcuate nucleus (ARCN), paraventricular nucleus (PVN) and supraoptic nucleus (SON). Seven days after right or left sinoaortic denervation (SAD), bilateral SAD or sham-operation (SO), in situ TH activity was determined by the rate of dihydroxyphenylalanine (DOPA) accumulation following administration of a dopa decarboxylase inhibitor. Unexpectedly, the intact, SO rats had significantly lower DOPA concentrations on the left than right sides of ME in two separate studies; right-left differences averaged 24% and 38%. Evidence supporting asymmetry of TH activity was the lower concentrations of catecholamines on left than right sides of the brain in intact SO rats, namely, dopamine in ME and ARCN and norepinephrine and epinephrine in ARCN. Unilateral and bilateral SAD further suppressed TH activity on the left side of the ME; the maximum right-left difference was 58% in rats with right SAD. Their ARCN also showed asymmetry of TH activity. Asymmetry of TH activity was attributable to asymmetry of TH protein which was significantly lower on the left sides of ME and ARCN. This is the first demonstration of bilateral asymmetry of TH in mediobasal hypothalamus and its enhancement by interruption of left or right afferents from the arterial vascular system.

Animals↗
PubMed1990

[Index of tumor response by in-vivo 31P-MRS--T1 effect as a new predicting index of therapeutic effects].

We observed the metabolism of the Yoshida sarcoma by in-vivo 31P-MRS, using two varieties of repetition time (TR), i.e., TR2s and TR10s. It was measured before the injection of 5FU and 4, 24, 48 hours after the injection. In the each time, PME/ATP ratio, intracellular pH, and TR10/TR2 ratio of PME which reflects the T1 value of PME, were calculated. TR10/TR2 ratio of PME decreased 4 and 24 hours after the injection of 5FU and recovered 48 hours after the injection to the same level before the injection. However decrease of PME/ATP ratio was not observed until 48 hours after the injection of 5FU, when apparent tumor regression appeared. These results suggested that the T1 value of PME decreased prior to the PME changes and when the PME decreased, the intracellular environment of PME recovered to the same state before the therapy. It was considered that the TR10/TR2 ratio of PME offers significant information different from the PME/ATP ratio. It is possible to use the TR10/TR2 ratio as a predicting index for the therapeutic effects.

Animals↗
PubMed1990

Production of active and passive anaphylactic shock in the WBB6F1 mouse, a mast cell-deficient strain.

The role of mast cells in active and passive anaphylactic shock was examined using the WBB6F1 mouse, a genetically mast cell-deficient strain. Lethal anaphylactic shock occurred at high incidence rates in mice actively sensitized to bovine serum albumin (BSA). The reaction was specific to BSA since the shock could not be elicited by human or guinea pig serum albumin in these animals. Lethal shock could be prevented by CV-3988 but not by cyproheptadine, which suggests that the shock is mediated by PAF but not by histamine and serotonin. Similarly, lethal shock was provoked by homologous antigens in mice which had been passively sensitized with allogeneic anti-benzylpenicilloyl (BPO) IgG1 monoclonal antibody or with allogeneic or xenogeneic anti-BSA antiserum, but not in those sensitized with allogeneic anti-BPO IgE monoclonal antibody. These findings suggest that mast cells are not necessarily required for anaphylactic shock in the mouse.

Anaphylaxis↗
PubMed1990

Small-angle neutron scattering from the reconstituted TF1 of H(+)-ATPase from thermophilic bacterium PS3 with deuterated subunits.

Subunits alpha, beta and gamma of adenosine triphosphatase (H(+)-ATPase) from the thermophilic bacterium PS3 (TF1) have been over-expressed in Escherichia coli. alpha and beta subunits deuterated to the level of 90% were obtained by culturing E. coli in 2H2O medium. Both the subunits and the reconstituted alpha beta gamma complex, TF1, which contain the deuterated components in various combinations, were studied in solution by small-angle neutron scattering. The individual shapes of the subunits and their organization in the alpha beta gamma-TF1 complex were examined using the techniques of selective deuteration and contrast variation. The alpha and beta subunits are well approximated as ellipsoids of revolution having minor semi-axes of 20.4(+/- 0.4) and 20.0(+/- 0.2) A, and major semi-axes of 53.0(+/- 1.4) and 55.8(+/- 0.9) A, respectively. In the TF1 complex, three beta subunits are aligned to form an equilateral triangle, with their major axes tilted by 35 degrees with respect to the 3-fold axis of the complex. The beta-beta distance is about 53 A. Three alpha subunits are similarly arranged, positioned between the beta subunits, and with their direction of tilt opposite to that of the beta subunits. The centers of the alpha and beta subunits lie in the same plane, forming a hexagon. Adjacent subunits overlap in this model, suggesting that they are not simple ellipsoids of revolution.

Bacteria↗
PubMed1990

Human gamma delta T-cell receptor-positive cell-mediated inhibition of erythropoiesis in vitro in a patient with type I autoimmune polyglandular syndrome and pure red blood cell aplasia.

The gamma delta T-cell receptor-positive (gamma delta TCR+) lymphocytes were markedly expanded up to 68% of peripheral blood lymphocytes in a case with type I autoimmune polyglandular syndrome and pure red blood cell aplasia (PRCA). The gamma delta TCR+ cells showed CD4 negative, 16% dim-CD8 positive and 10% to 46% human leukocyte antigen-D-related (HLA-DR) positive, and exhibited no monoclonality as assessed by the patterns of TCR gene rearrangements. Functional studies revealed that the proliferative responses of the patient's peripheral blood mononuclear cells (PBMC) were severely depressed to candida antigen, alloantigens, and autoantigens (non-T cells). The gamma delta TCR+ cells had no suppressive effect on the proliferative response of the alpha beta TCR+ cells to candida. The patient's PBMC, isolated gamma delta TCR+ cells but not alpha beta TCR+ cells, exhibited non-major histocompatibility complex (MHC)-restricted cytotoxicity. Furthermore, the patient's PBMC and isolated gamma delta TCR+ cells inhibited burst-forming units-erythroid (BFU-E), but not colony-forming units/granulocyte-macrophage (CFU-GM). Supernatants derived from the patient's T cells similarly inhibited BFU-E but not CFU-GM. The clinical course of the patient also showed a close correlation between the decreased number of total lymphocyte counts, especially HLA-DR + gamma delta TCR+ cell counts, and recovery from PRCA. These observations suggest that the gamma delta TCR+ cells might be functional in vivo and involved in the pathogenesis of PRCA in this patient.

Adult↗
PubMed1990

Central nervous system involvement in adult T-cell leukemia/lymphoma.

Central nervous system (CNS) involvement was reviewed in 99 patients with adult T-cell leukemia/lymphoma (ATLL). Fifteen episodes of CNS involvement developed in ten of 99 patients (10.1%); nine had leptomeningeal involvement, whereas two developed intracerebral invasion, one developed cord involvement, and one developed both. CNS involvement was more frequent in the lymphoma type than in the other types of ATLL. Nuchal rigidity was not common (33%) and a syndrome of inappropriate secretion of antidiuretic hormone (ADH) occurred in association with CNS involvement (40%). Three episodes of marked hypoglycorrhachia also were noticed. The systemic progression of ATLL was the most common setting of CNS involvement (80%) and the major cause of death (80%). As for the acute and lymphoma types of ATLL, no significant difference was observed in survival between patients with and those without CNS involvement. These results indicate that CNS involvement is not an essential prognostic factor of ATLL and that it should be treated with systemic chemotherapy coupled with intrathecal chemotherapy. The control of systemic ATLL is important for the prophylaxis of CNS involvement.

Adult↗
PubMed1990

Transient engraftment of syngeneic bone marrow after conditioning with high-dose cyclophosphamide and thoracoabdominal irradiation in a patient with aplastic anemia.

We describe the clinical course of a 16 year old girl with aplastic anemia who was treated by syngeneic bone marrow transplantation. Engraftment was not obtained by simple infusion of bone marrow without immunosuppression. The patient received a high-dose cyclophosphamide and thoracoabdominal irradiation, followed by second marrow transplantation from the same donor. Incomplete but significant hematologic recovery was observed; however, marrow failure recurred 5 months after transplantation. Since donor and recipient pairs were genotypically identical, graft failure could not be attributed to immunological reactivity of recipient cells to donor non-HLA antigens. This case report implies that graft failure in some cases of aplastic anemia might be mediated by inhibitory cells resistant to cyclophosphamide and irradiation.

Abdomen↗
PubMed1990

Spontaneous remission from acute exacerbation of chronic adult T-cell leukemia.

Spontaneous remission without any anti-cancer therapy in a 57-year-old woman with adult T-cell leukemia (ATL) is reported. The patient was referred to our department because of persistent cough and appearance of abnormal lymphocytes in the peripheral blood, and she was diagnosed as having chronic ATL. Eight months later, she was re-admitted because of cystitis, watery diarrhea and worsening of respiratory symptoms with an increase of ATL cells (WBC 31 x 10(9)/l with 56% ATL cells). Acute exacerbation of ATL was diagnosed. Interestingly, antibiotic therapy for the pulmonary and urinary tract infections brought about spontaneous reduction of the ATL cell count. Spontaneous remission of ATL continued for one year without chemotherapy. The role of infection as a trigger of acute exacerbation and spontaneous remission of ATL is discussed.

Amphotericin B↗
PubMed1990

Hemorrhage-induced regional brain thyrotropin-releasing hormone release in conscious rats measured by microdialysis.

The septum, nucleus accumbens and preoptic area in the brains of conscious, freely moving rats were perfused using microdialysis probes. The TRH concentration significantly increased in the septum after withdrawal of 30% of the total blood volume but remained at constant levels in the other brain areas. Also, high potassium dose-dependently stimulated TRH release in vivo. These results suggest that blood loss stimulates septal TRH release, probably by membrane depolarization of TRH-containing nerve terminals.

Animals↗
PubMed1990

Clinical characteristics of hybrid leukemia: report of five cases.

We studied clinical and biological features of five cases of hybrid leukemia. Three of the five patients were classified as biphenotypic leukemia because of the coexpression of myeloid/B lymphoid markers in patients 1 (FAB M2) and 2 (FAB CMMoL) and myeloid/T lymphoid markers in patient 3 (FAB M4). Patient 4 was identified as bilineal-biphenotypic leukemia because acute myelogenous leukemia (AML) (FAB M4) and acute lymphoblastic leukemia (ALL) (FAB L1) coexisted and each population coexpressed myeloid and T lymphoid markers. Patient 5 was identified as bilineal leukemia due to the conversion from AML (FAB M1) to ALL (FAB L1) at an interval of 3 months. The Philadelphia (Ph1) chromosome was negative in all cases. A leukemic blast colony formation using cell line 5637 conditioned medium as a stimulator was obtained in all four patients examined. Three of the five patients had been suffering from so-called stem cell disorders such as aplastic anemia in patient 2, trilineage myelodysplasia in patient 4 and refractory anemia with excess of blasts in transformation in patient 5. The pre-existing impairment of pluripotent stem cell was probably the background of these hybrid leukemia. Hybrid leukemia appears to have an inferior prognosis: an AML-directed chemotherapy resulted in a low remission rate (2/5) with a short duration of relapse free survival (1/2) and an ALL-directed chemotherapy produced no remission (0/3). Chronological phenotypic analysis revealed that hybrid features of leukemic blasts disappeared at the time of relapse in patient 1 and progression to AML in patient 2. Monitoring of lineage-associated markers should be required for the management of hybrid leukemia.

Adult↗
PubMed1990

Treatment of myelodysplastic syndrome and atypical leukemia with low-dose aclarubicin.

To study the therapeutic effect of low-dose aclarubicin (ACR), we carried out comparative treatment of 15 patients with myelodysplastic syndrome (MDS) and atypical leukemia using this drug. Complete remission (CR) was achieved in three patients with RAEB-t and one patient with AML, partial remission was obtained in one patient with RAEB and hematological improvement in one patient with refractory anemia (RA). Interestingly, prolonged CR for more than 26 months with persistent chromosomal abnormalities was observed in a case of AML, which progressed from RA. Myelosuppression caused by low-dose ACR was milder than that caused by low-dose Ara-C. Furthermore, in vitro studies indicated that ACR induced differentiation of bone marrow cells from one patient with MDS. From these observations, it is suggested that low-dose ACR may be an alternative to low-dose Ara-C for treatment of MDS, and that the in vivo effect of ACR may be mediated by the differentiation of abnormal hemopoietic clones.

Aclarubicin↗
PubMed1990

Prevention of overt diabetes and insulitis in NOD mice by a single BCG vaccination.

A single intravenous injection of 0.25-1 mg of live BCG organisms at approximately 10 weeks of age produced a potent suppression of insulitis and overt diabetes in non-obese, diabetes-prone (NOD) female mice. Injection of 1 mg of BCG into younger mice, aged 5 weeks, was also very suppressive but the injection into older mice of 15 weeks was somewhat less suppressive. Spleen cell transfer from the BCG-vaccinated NOD mice prevented the occurrence of overt diabetes in the recipients, while the transfer from untreated donors did not. This indicates the generation of some type of suppressor cells in the BCG-vaccinated mice.

Animals↗