Biomedical subjects

Takashi Ishiguro

Publications and source records attributed to Takashi Ishiguro.

8 recordsLinked to original sources

PubMed2006

Lack of histamine type-1 receptors impairs the thermal response of respiration during hypoxia in mice (Mus musculus).

Thermoregulation and the hypoxic ventilatory response are modulated by histamine type-1 (H1) receptors in the brain. In this study, we tested the hypothesis that activation of H1 receptors is required for the thermal control of ventilation during normoxia and hypoxia, using conscious male wild-type and H1 receptor-knockout (H1RKO) mice (Mus musculus). Under normoxic conditions, hyperthermia (39 degrees C) decreased minute ventilation (V (E)) and oxygen consumption [Formula: see text] in both genotypes, suggesting that H1 receptors are not involved in thermal ventilatory control during normoxia. Pa(CO2) was unchanged in both hyperthermia and normothermia, suggesting that the thermal decrease in V (E) is optimized by metabolic demand. Acute hypoxic gas exposure (7% O(2)+3% CO(2) in N(2)) increased, and then decreased, V (E) in wild-type mice; this increase was augmented and sustained by hyperthermia. Hypoxic gas exposure reduced [Formula: see text] and [Formula: see text] in wild-type mice at both body temperatures; the reduced [Formula: see text] during combined hyperthermia and hypoxia was higher than during normothermia and hypoxia. In H1RKO mice, hyperthermia did not augment the V (E) response to hypoxia, and did not affect [Formula: see text] and [Formula: see text] during hypoxia. In conclusion, histamine participates in the thermal increase of ventilation during hypoxia by activating H1 receptors.

Aerobiosis↗

PubMed2006

Contribution of histamine type-1 receptor to metabolic and behavioral control of ventilation.

Histaminergic neurons in the hypothalamus are well documented as being involved in the control of autonomic functions, such as the balance of energy metabolism and circadian rhythm. We tested the hypothesis that an activation of the histamine type-1 (H1) receptor is required for the control of ventilation during the course of a day in free-moving mice. Ventilation, aerobic metabolism, and electroencephalogram were measured by a whole-body-plethysmograph, a magnetic-type mass spectrometry system, and a telemetry system, respectively, in H1 receptor-knockout (H1RKO) and wild-type mice. Both genotypes showed daily oscillations in minute ventilation (V(E)) and oxygen consumption (VO(2)), with greater values during the dark period compared to the light period. In the latter, H1RKO mice showed increased V(E) and CO(2) excretion (VCO(2)) relative to wild-type mice, and V(E) was comparable to the VCO(2) increase. However, there was no change in VO(2) in H1RKO mice, suggesting that differences in VCO(2) between genotypes are responsible for differences in V(E) during the light period. During the dark period, VCO(2) was elevated in H1RKO mice compared with WT mice. Because there was no difference in V(E), the ratio of V(E) to VCO(2) was reduced in H1RKO mice. Electroencephalogram results suggested that this might be due to a depressed arousal state in H1RKO mice because the ratio of delta to theta band power spectrum densities was greater in H1RKO mice than in wild-type mice. We concluded that histamine modulates ventilation by affecting metabolism and arousal state via H1 receptors.

Animals↗

PubMed2006

Impaired ventilation and metabolism response to hypoxia in histamine H1 receptor-knockout mice.

The role of central histamine in the hypoxic ventilatory response was examined in conscious wild-type (WT) and histamine type1 receptor-knockout (H1RKO) mice. Hypoxic gas (7% O(2) and 3% CO(2) in N(2)) exposure initially increased and then decreased ventilation, referred to as hypoxic ventilatory decline (HVD). The initial increase in ventilation did not differ between genotypes. However, H1RKO mice showed a blunted HVD, in which mean inspiratory flow was greater than that in WT mice. O(2) consumption (V(O2)) and CO(2) excretion were reduced 10min after hypoxic gas exposure in both genotypes, but (V(O2)) was greater in H1RKO mice than in WT mice. The ratio of minute ventilation to (V(O2)) during HVD did not differ between genotypes, indicating that ventilation is adequately controlled according to metabolic demand in both mice. Peripheral chemoreceptor sensitivity did not differ between genotypes. We conclude that central histamine contributes via the H1 receptor to changes in metabolic rate during hypoxia to increase HVD in conscious mice.

Animals↗

PubMed2006

[Bronchofiberscopic treatment for malignant tracheobronchial tumor].

We evaluated bronchofiberscopic treatment for 38 cases with malignant tracheobronchial tumor. We performed bronchofiberscopic ethanol injection therapy in 13 cases, endoscopic diode laser treatment in 19 cases and airway stent insertion in 9 cases. Each treatment was comparatively easy and improved symptoms such as dyspnea effectively.

Aged↗

PubMed2005

On-line microdevice for stress proteomics.

The handling of the cells or tissues is essential for proteomics research or drug screening, where labor is not avoidable. The steps of cell wash, protein extraction, protein denaturing are complicated procedures in conventional method using centrifugation and pipetting in the laboratory. This is the bottle-neck for proteome research. To solve these problems, we propose to utilize the nanotechnology, which will improve the proteomics methodology. Utilizing the nanotechnology, we developed a novel microseparation system, where centrifugation and pipetting are needless. This system has a nanostructured microdevice, by which the cell handling, protein extraction, and antibody assay can be performed. Since cell transfer is needless, all cells are corrected without any loss during the cell-pretreatment procedures, which allowed high reproducibility and enabled the detection of low amount of protein expression. Utilizing the microdevice, we analyzed the stress induced proteins. We further succeeded the screening of food that was useful for immunity and found that an extraction from seaweed promoted the apoptosis of T-lymphoblastic cells. Here, we present an on-line microdevice for stress proteomics.

Nanotechnology↗

PubMed2004

[Bronchoscopic treatment for malignant tracheobronchial stenose].

We evaluated a bronchoscopic treatment for malignant tracheobronchial stenose in 28 patients. We performed an ethanol injection treatment in 12 patients, bronchoscopic diode laser treatment in 16 patients and airway stent implantation in 6 patients by flexible bronchofiberscopy. Each of these treatments is comparatively an easy method with no serious adverse reaction. It is suggested that these treatments may be effective for tracheobronchial stenose if we select patients carefully and combine the methods listed here.

Aged↗

PubMed2003

[Lung toxicity of trimodality chemoradiotherapy with mitomycin C, vindesine, and cisplatin followed by surgery for locally advanced non-small cell lung cancer].

To evaluate lung toxicity of mitomycin C containing chemotherapy regimen combined with thoracic radiotherapy, a retrospective study was carried out in patients with locally advanced non-small cell lung cancer who were enrolled in a randomized trial for chemoradiotherapy. Postoperative complications and pathological pulmonary toxicity were investigated in 7 surgical patients out of 306 enrolled patients who were treated with MVP combination chemotherapy and concurrent or sequential thoracic radiotherapy of 56 Gy. The 7 patients were 45-66 years old (median 50 years old), with 4 of stage IIIA, 3 of stage IIIB, 4 with adenocarcinoma, 2 with squamous cell carcinoma, and 1 with large cell carcinoma. Five patients were treated with 2 cycles and 2 with 3 cycles. Anti-tumor response was observed to be PR in 6 cases and NC in 1 case. In the chemoradiotherapy, pulmonary toxicity was observed at grade 1 in only 1 case. Postoperative complications consisted of a ruptured suture, chylothorax and empyema which were treated and healed in the 3 cases respectively. Pathological examination of the resected lung was performed in 6 cases, with revealed alveolitis in 3 cases and fibrosis in all cases in the radiation field. Three cases, however, showed slight alveolitis outside of the radiation field. In conclusion, as severe lung toxicity was not observed in the surgical cases after chemoradiotherapy including MMC, there appears to be no reason to exclude MMC from regimens for trimodality combination therapy.

Aged↗

PubMed2002

[Treatment of tracheobronchial malignant tumors using a new high power diode contact laser (GaAlAs) system].

We treated ten patients with tracheobronchial malignant tumors using a new high power diode contact laser (GaAlAs) system (DIOMED 25, OLYMPUS) with a flexible bronchofiberscope (OLYMPUS BF IT200 or BF IT240). The total energy of the high power diode laser was 811 J, with a range of 64-3,960 J. With this method 85.7 percent of the symptoms such as dyspnea and hemoptysis were improved, and there was no incidence of massive hemorrhage or serious respiratory failure. The results confirmed the usefulness and safety of this method of treatment for obstructive lesions due to tracheobronchial polypoid malignant tumor and bleeding of the tracheobronchial tree.

Aged↗