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Biomedical subjects

T Hisada

Publications and source records attributed to T Hisada.

At least 37 records · Page 2Linked to original sources
PubMed1997

Effects of the calcium ionophore A23187 on airway responsiveness to histamine and substance P in guinea pigs.

OBJECTIVE: We evaluated the mechanism of the airway hyperresponsiveness (AHR) induced by a calcium ionophore in guinea pigs. MATERIALS AND METHODS: Airway responsiveness to intravenous histamine (HS) and substance P (SP) was measured 24 h after a 1-h exposure to aerosolized A23187 (0.03 or 0.1 mg/ml) or its vehicle (10% DMSO). Changes were assessed by calculating -logPC350HS and logPC350SP. Neutral endopeptidase (NEP) activity in the airway tissues, as well as the nitrite (NO2) levels and the cell population in bronchoalveolar lavage fluid (BALF) was determined after measurement of pulmonary function. Changes in SP-induced vascular permeability 24 h after exposure to A23187 were measured by the Evans Blue dye extravasation technique. RESULTS: Exposure to A23187 caused a significant AHR to SP, along with a significant increase in the number of neutrophils and epithelial cells in the BALF. While there was no significant change in NEP activity in the airway tissues, the levels of nitrite in the BALF were significantly decreased in A23187-exposed animals. Significant correlations were found between the number of epithelial cells in the BALF and logPC350SP (r = 0.477, p < 0.05) and between nitrite levels in the BALF and -logPC350SP (r = 0.491, p < 0.05) A23187 exposure did not significantly change the SP-induced airway microvascular leakage. CONCLUSIONS: These data suggest that A23187 exposure induced AHR to SP possibly by reducing NO levels in the airway tissues. This may be due to damaged airway epithelium and/or NO breakdown by activated inflammatory cells in the airways of these guinea pigs.

Animals↗
PubMed1997

Thromboxane inhibition and monocrotaline-induced pulmonary hypertension in rats.

Monocrotaline (MCT)-induced pulmonary hypertension (PH) is a useful model for the investigation of this disorder in humans. The role of thrombocytes in the genesis of PH has already been addressed; however, the exact mechanism by which they induce PH remains to be elucidated. We investigated the effects of a thromboxane A2 (TXA2) synthase inhibitor (OKY-046) and a TXA2/prostaglandin H2 (PGH2) receptor antagonist (ONO-8809) on the development of MCT-induced PH. A single dose of MCT (60 mg/kg bodyweight; BW) was injected subcutaneously in Wistar rats 24 h after the administration of OKY-046 or ONO-8809. The TXA2 inhibitors were administered by gavage daily for 3 weeks. Urinary excretion of eicosanoids was determined by radioimmunoassay. At the end of the treatment period, the lungs, heart and kidneys were morphologically examined. The per cent medial thickness of the muscular pulmonary arteries (%MT) and the ratio of the right to the left ventricular mass including the septum (RV/LV + S) increased significantly in MCT-treated rats compared with the control rats. The %MT was attenuated by the administration of ONO-8809. Either OKY-046 or ONO-8809 attenuated the increase in RV/LV + S. In addition, both TXA2 inhibitors reduced urinary excretion of 11-dehydro-TXB2, particularly during the early phase of PH, suggesting that platelet aggregation was reduced. These findings suggest that the inhibition of TXA2 by synthase inhibition or receptor antagonism reduces or delays the development of MCT-induced PH in rats, probably by inhibiting platelet aggregation.

Animals↗
PubMed1996

The direct effect of interferon-gamma on human eosinophilic leukemia cell lines: the induction of interleukin-5 mRNA and the presence of an interferon-gamma receptor.

The EoL-1 and EoL-3, human eosinophilic leukemia cell lines, have been used as models for studying the maturation and the function of human eosinophils. We investigated the effects of interferon-gamma (IFN-gamma) on superoxide anion (O2-) production of these cell lines and interleukin-5 (IL-5) mRNA expression in the EoL-1. O2- was measured by chemiluminescence of MCLA, one of cypridina luciferin analogs. The O2- production of fMLP-stimulated EoL-1 and EoL-3 was increased by the IFN-gamma treatment. IL-5 mRNA expression was detected in the IFN-gamma-treated EoL-1 by reverse transcription-polymerase chain reaction (RT-PCR). Further, we examined IFN-gamma receptor 1 mRNA expression in these cell lines and peripheral blood eosinophils by means of northern blot hybridization. IFN-gamma receptor 1 mRNA was detected in the EoL-3 and the IFN-gamma-treated EoL-1. A weak expression of IFN-gamma receptor 1 mRNA was detected in peripheral blood eosinophils isolated from a patient with eosinophilia. These results suggest that IFN-gamma may act on eosinophils directly through its receptor.

Antigens, CD↗
PubMed1995

Effects of interferon-gamma on cell differentiation and cytokine production of a human monoblast cell line, U937.

The U937 cell, a human monoblast cell line, has been used as a model to study the function of human monocytes. We investigated the effects of interferon-gamma (IFN-gamma) on superoxide anion (O2-) production, cell surface antigens, and cytokine production of U937 cells. IFN-gamma treatment enhanced O2- production of fMLP or PMA-stimulated U937 cells. IFN-gamma increased the ratio of CD23 and CD11b positive cells. The fluorescence intensity of CD14 and CD25 was enhanced by IFN-gamma treatment. U937 cells produced IL-1 alpha, IL-1 beta, IL-6, and TNF-alpha by lipopolysaccharide (LPS) stimulation. IFN-gamma treatment enhanced TNF-alpha production, but decreased IL-6 production. These results suggest that IFN-gamma differentiates U937 cells to monocyte-like cells and it regulates the production systems of IL-6 and TNF-alpha separately in U937 cells.

Antigens↗
PubMed1995

[Effects of Onpi-to (TJ-8117) on mesangial injury induced by anti Thy-1 antibody].

We investigated the effect of Onpi-to (TJ-8117) on the mesangial injury induced by anti-Thy-1 antibody. TJ-8117 (400 mg/kg/day, p.o.) given from the 1st day (from the day of injection of the anti-thymocyte serum) or 4th day (after mesangial proliferation), markedly inhibited the mesangial proliferation and hypercellularity in glomeruli. TJ-8117 prevented the increase in the number of PCNA or ED-1 positive cells in glomeruli. These results suggest that TJ-8117 is effective against glomerular disease with mesangial injury.

Animals↗
PubMed1995

Hereditary hemorrhagic telangiectasia showing severe anemia which was successfully treated with estrogen.

Hereditary hemorrhagic telangiectasia (Osler-Weber-Rendu disease) is a bleeding disorder attributed to a vascular developmental abnormality. It is transmitted as an autosomal dominant trait. A 63-year-old female was admitted because of repeated episodes of severe anemia which resulted from bleeding of telangiectases in the gastric mucosa. Conventional therapies including endoscopical microwave coagulation and ethanol injection were not effective. The persistent anemia necessitated frequent blood transfusion. Estrogen was orally administrated and blood transfusion became unnecessary. Thus, estrogen therapy should be considered as one of the effective treatments for recurrent severe anemia due to hereditary hemorrhagic telangiectasia.

Administration, Oral↗
PubMed1994

Effects of azelastine on membrane currents in tracheal smooth muscle cells isolated from the guinea-pig.

Azelastine [4-(p-chlorobenzyl)-2-(hexahydro-1-methyl -1H-azepin-4-yl)-1-(2H)-phthalazinone hydrochloride], an anti-allergic agent, inhibited the high K(+)-induced contraction in tracheal smooth muscle cells isolated from the guinea-pig. In order to investigate the ionic mechanisms, we examined the effects of azelastine on membrane currents, using the tight-seal whole cell voltage clamp technique. Azelastine (1-100 microM) caused an inhibition of the Ba2+ inward current (IBa) through the voltage-dependent L-type Ca2+ channel in a concentration-dependent manner. The inhibitory effect of azelastine on IBa was fully reversible. The IC50 value for azelastine-induced inhibition of IBa was approximately 8 microM, and 100 microM azelastine completely suppressed IBa. Azelastine exerted mainly a tonic block of IBa but did not show use dependence. Azelastine (10 microM) shifted the quasi-steady-state inactivation curve of IBa to more negative membrane potentials by approximately -20 mV, suggesting that the inhibitory effect of azelastine on IBa was voltage-dependent. In addition, azelastine produced inhibitory actions on other membrane currents (i.e. the voltage-dependent transient outward K+ current and the Ca(2+)-activated oscillatory K+ current) at doses higher than 10 microM. These results suggest that azelastine inhibits the voltage-dependent L-type Ca2+ current in single tracheal smooth muscle cells, which may contribute to the anti-allergic actions of azelastine in airways.

Animals↗
PubMed1993

Stretch-inactivated cationic channels in single smooth muscle cells.

Stretch-inactivated channels (SICs) were identified in single smooth muscle cells freshly dissociated from the stomach of the toad, Bufo marinus. In both cell-attached and excised inside-out patches, negative pressure applied to the extracellular surface of the membrane patch suppressed the activity of SICs. These channels were permeable to cations and were not significantly permeable to Cl-. The current-voltage relationship showed outward rectification in cell-attached patches with high NaCl in the pipette solution (2 mM MgCl2), and the slope conductance at negative potentials was approximately 8 pS under these conditions. When divalent cations were eliminated from the pipette solution, the slope conductance at negative potentials increased to approximately 30 pS. No significant voltage dependence of SIC gating could be observed between -100 mV and 60 mV.

Animals↗
PubMed1993

Aluminofluoride activates hyperpolarization- and stretch-activated cationic channels in single smooth muscle cells.

Aluminofluoride (AF) has a variety of biological actions such as activation of GTP binding proteins and inhibition of phosphatases. In the present study, the effects of AF on hyper-polarization- and stretch-activated cationic channels (HA-SACs) were investigated in isolated gastric smooth muscle cells from the toad, Bufo marinus, using the patch-clamp technique. In cell-attached patches extracellular application of AF (20 mM KF plus 20 microM AlCl3) reversibly increased HA-SAC activity without changing its voltage sensitivity. The single channel current amplitude of HA-SACs was not affected during this procedure. The mechanism of AF-induced activation of HA-SACs remains unclear. However, this activation may play a role in contraction of smooth muscle induced by AF.

Aluminum↗
PubMed1993

[A case of intralobar pulmonary sequestration associated with an accessory diaphragm].

We report one operated case (a 71-year-old female) of intralobar pulmonary sequestration (Pryce's type 1) associated with an accessory diaphragm. The patient had hemoptysis for 5 years. Lateral chest X-ray showed an oblique line attaching to the central portion of the right diaphragm. Selective angiography and ultrasonography showed an aberrant vessel originating from the abdominal aorta. At the time of operation, the pleural cavity was divided into two compartments by a fibrous membrane. The bronchus of the lower compartment and the pulmonary veins ran through a hole in the accessory diaphragm. The aberrant artery flowed into the parts of lung in the upper and lower compartments.

Abnormalities, Multiple↗
PubMed1993

[Measurement of bone mineral density using dual energy X-ray absorptiometry in asthmatic patients receiving prednisolone therapy].

Bone mineral density (BMD) of the lumbar spine (L2-L4) was measured using dual-energy X-ray absorptiometry (DEXA), and its relationship to total dose of prednisolone and duration of prednisolone therapy was studied in 57 patients with bronchial asthma. There was a significant negative correlation between BMD and total dose of prednisolone (r = -0.463, p < 0.001) and between BMD and duration of prednisolone treatment (r = -0.30, p < 0.05). The half-yearly percent decrease of BMD measured in 17 asthmatic patients was 0.83% (p < 0.01) after correction for age-associated decline. These findings suggest that the reduction of BMD was related to the total dose of prednisolone and the duration of therapy in asthmatics.

Absorptiometry, Photon↗
PubMed1993

[Clinical studies on ceftriaxone in respiratory tract infections. CTRX Study Group].

We report that the results of clinical studies on ceftriaxone (CTRX) in respiratory tract infections (RTIs). Clinical efficacies and side effects of CTRX were as follows; 1. Clinical efficacies of CTRX in a total of 61 cases with RTIs were excellent in 11 cases, good in 23, fair in 11, poor in 12 and unknown in 4. Thus the overall clinical efficacy rate was 59.6%. In cases of patients with lung cancers, the efficacy rate was 42.9%. 2. Clinical efficacy rates with once daily dosage were 50.0% with a dose level of 1 g CTRX and 54.8% with that of 2 g CTRX. 3. Side effects were observed in 2 cases (3.1%) and laboratory abnormalities were observed in 1 case (1.6%). They were not serious, however. These data suggest that CTRX is one of the useful cephalosporins in treatment of RTIs.

Adult↗
PubMed1992

Effect of phospholipase A2 inhibitor ONO-RS-082 on substance P-induced histamine release from rat peritoneal mast cells.

Rat peritoneal mast cells purified on a Percoll gradient were challenged with substance P (SP) and the effect of phospholipase A2 inhibitor ONO-RS-082 on SP-induced histamine release from the cells was investigated. 10(-5) mol/l SP caused a significant histamine release and the amount of histamine release reached maximum at 1 min after the challenge. ONO-RS-082 inhibited the SP-induced histamine release in a concentration-dependent manner at the concentration from 10(-6) to 10(-4) mol/l, suggesting possible involvement of phospholipase A2 in SP-induced histamine release from rat peritoneal mast cells.

Aminobenzoates↗
PubMed1992

On the mechanism of papaverine inhibition of the voltage-dependent Ca++ current in isolated smooth muscle cells from the guinea pig trachea.

The effects of papaverine, a smooth muscle relaxant agent, on the voltage-dependent Ca++ current were examined in isolated smooth muscle cells from the guinea pig trachea. The tight-seal whole cell voltage clamp technique was used. Papaverine (1-100 microM) inhibited the Ba++ inward current (IBa) through the voltage-dependent L-type Ca++ channel in a concentration-dependent fashion. The inhibitory effect of papaverine on IBa appeared to have both tonic and use-dependent components. In addition to the reduction of the maximal conductance of IBa, papaverine (20 microM) shifted the quasi-steady-state inactivation curve of IBa to more negative membrane potentials by approximately 10 mV. These effects of papaverine on IBa were completely reversible. Although it has been suggested that papaverine inhibited phosphodiesterase to increase intracellular cyclic AMP, phosphodiesterase inhibitors (theophylline, 500 microM, and 3-isobutyl-1-methylxanthine, 500 microM), isoproterenol (2 microM) and dibutyryl cyclic AMP (1 mM) did not affect IBa. Thus, papaverine inhibits IBa in a way independent of intracellular cyclic AMP. Papaverine also had inhibitory effects on other membrane currents (i.e., the voltage-dependent transient outward K+ current and the Ca(++)-activated oscillatory K+ current), which may result in an enhancement of the excitability of the cells. These results suggest that inhibition of the voltage-dependent L-type Ca++ channel is involved in the papaverine-induced relaxation of the tracheal smooth muscle.

Animals↗
PubMed1991

Hyperpolarization-activated cationic channels in smooth muscle cells are stretch sensitive.

The properties of hyperpolarization-activated channels were studied in single smooth muscle cells from the stomach of the toad, Bufo marinus, using the patch-clamp technique. In cell-attached patches, inward channel currents were activated by hyperpolarizing pulses from a holding potential of -20 mV to potentials more negative than -60 mV. The activity of the channels increased and their latency of activation decreased as the hyperpolarization was increased. The slope conductance of the channels with standard high sodium concentration pipette solution was 64.2 +/- 9.1 pS (SD, n = 17). Stretching the patch, by suction applied to the back of the patch pipette, also increased the activity and shortened the latency of activation. We designate these channels as HA-SACs (hyperpolarization- and stretch-activated channels). HA-SACs were observed in 83% (175/210) of the patches studied. HA-SAC currents were carried by sodium and potassium ions, but their amplitude was increased by replacing extracellular sodium with potassium. Extracellular magnesium and calcium ions significantly reduced the single-channel conductance of HA-SACs. These permeation characteristics and the single-channel conductance of HA-SACs were indistinguishable from those of stretch-activated channels (SACs) previously described in these cells. The following observations are consistent with HA-SACs being a subset of SACs. First, SACs were at times found in cell-attached patches which lacked HA-SACs. Second, the number of channels in a cell-attached patch simultaneously activated by stretch (usually 5-10 and often more) exceeded by far the number simultaneously activated by hyperpolarization (usually one or two).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

[Effect of phospholipase A2 inhibitor on substance P-induced histamine release from rat peritoneal mast cells].

Rat peritoneal mast cells purified on a Percoll gradient were challenged with substance P and effect of phospholipase A2 inhibitor ONO-RS-082 on substance P-induced histamine release from the cells were investigated. Substance P at the concentration of 10(-5) M caused a significant histamine release and the amount of histamine release reached to its submaximum at 1 min after the challenge and then slowly increased. ONO-RS-082 inhibited the substance P-induced histamine release in a concentration-dependent manner at the concentration from 10(-6) to 10(-4) M, suggesting that phospholipase A2 may play some roles in the process of substance P-induced histamine release from rat peritoneal mast cells.

Aminobenzoates↗