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Biomedical subjects

H Inoue

Publications and source records attributed to H Inoue.

At least 361 records · Page 20Linked to original sources
PubMed2000

Heterogeneous cardiac sympathetic innervation in heart failure after myocardial infarction of rats.

We examined cardiac neuronal function and beta-receptor with a dual-tracer method of [(131)I]meta-iodobenzylguanidine (MIBG) and [(125)I]iodocyanopindolol (ICYP) in rat heart failure after myocardial infarction (MI). In rats with MI, left ventricular (LV) systolic function decreased, and LV dimension and right ventricular (RV) mass increased gradually. MIBG accumulations of the noninfarcted LV (remote region) and RV decreased by 15% at 1 wk compared with sham-operated rats, and these accumulations were restored by 71% and 56%, respectively, at 24 wk compared with age-matched sham rats despite sustained depletion of myocardial norepinephrine contents in these regions. ICYP accumulation of the remote region and of the RV did not decrease at any stages. Myocardial MIBG distribution was heterogeneous at 1 wk when it was lower in the peri-infarcted region than in the remote region, associated with reduced ICYP accumulation in the peri-infarcted region. The heterogeneous distribution of both isotopes disappeared at 12 wk. Thus cardiac sympathetic neuronal alteration was coupled with downregulation of beta-receptors in rat heart failure after MI. The abnormal adrenergic signaling occurred heterogeneously in terms of ventricular distribution and time course after MI.

3-Iodobenzylguanidine↗
PubMed2000

Evolution of left ventricular involvement in arrhythmogenic right ventricular cardiomyopathy.

Left ventricular (LV) involvement in arrhythmogenic right ventricular cardiomyopathy (ARVC) is fairly well known, but the evolution of LV involvement during long-term follow-up has not been well documented. We describe such evolution in a patient followed for 9 years. Evolution was confirmed by a progressive perfusion defect of the LV wall in myocardial scintigrams and by the development of LV asynergy with ventricular aneurysm formation in left ventriculograms. As the right ventricle progressively enlarged, we concluded that ARVC is a diffuse and progressive myocardial disease that affects both ventricles.

Adult↗
PubMed2000

Once-daily theophylline reduces serum eosinophil cationic protein and eosinophil levels in induced sputum of asthmatics.

BACKGROUND: Because eosinophilic airway inflammation is a characteristic feature of bronchial asthma, the treatment of airway inflammation is important in the management of asthma. Theophylline has been reported to reduce airway inflammation, in addition to its well-known bronchodilating effect. OBJECTIVE: In order to evaluate the effects of theophylline on airway inflammation, we investigated 48 subjects with mild and moderate asthma. METHODS: The patients were randomly divided into two groups, with or without theophylline treatment (control n = 24; theophylline, n = 24). We examined the level of serum eosinophil cationic protein (ECP), induced sputum samples, and peak expiratory flow (PEF) and obtained spirograms before and after 4 weeks of treatment with once-daily theophylline (200-600 mg/day) of subjects with mild or moderate asthma. RESULTS: Theophylline significantly increased morning and evening PEF and significantly decreased the diurnal variation of PEF. After treatment with theophylline, both serum ECP and the percentage of eosinophils in induced sputum were significantly decreased. In contrast, peripheral blood eosinophil count was unchanged after treatment with theophylline. CONCLUSIONS: These findings suggest that theophylline reduces airway inflammation and the severity of asthma, presumably via suppression of both eosinophil activity and subsequent eosinophil infiltration of the airways.

Adolescent↗
PubMed2000

Histamine-induced increase in isometric tension of smooth muscle is mediated by local vagus nerve in human bronchus.

BACKGROUND: The vagus nerve is reported to play an important role in the regulation of airway responsiveness. OBJECTIVE: In the present study, we investigated the role of the local vagus nerve in the changes in isometric tension of smooth muscle induced by histamine in the human airway. METHODS: Eight human lung tissue specimens were obtained at thoracic surgery, and 24 bronchial smooth muscle strips were used for isometric tension recording. The changes in isometric tension were induced by histamine in the presence or absence of physostigmine (10(-6) M), atropine (10(-6) M), and/or tetrodotoxin (10(-6) M). RESULTS: We found that: (1) histamine induced a dose-dependent increase in the isometric tension in human bronchial smooth muscle; (2) physostigmine (10(-6) M) significantly potentiated the amplitude of the histamine-induced increase in isometric tension; (3) atropine (10(-6) M) significantly suppressed the histamine-induced increase in isometric tension; (4) tetrodotoxin (10(-6) M), did not affect the histamine-induced increase in isometric tension of smooth muscle, and (5) in the presence of tetrodotoxin, atropine significantly suppressed the histamine-induced increase in isometric tension. CONCLUSION: These findings suggest that the histamine-induced increase in isometric tension is mediated partly by acetylcholine, presumably released by the direct action of histamine on the vagus efferent nerve terminals without the central reflex via vagus nerve.

Atropine↗
PubMed2000

Renal structural properties in prehypertensive Dahl salt-sensitive rats.

In 10- to 12-week-old Dahl salt-sensitive (DS) and salt-resistant (DR) rats fed a 0.3% salt diet (n=10 in each group), flow-pressure and pressure-glomerular filtration rate (F-P and P-GFR, respectively) relationships were established for maximally vasodilated perfused kidneys. From these relationships, 3 indices of vascular structural properties were estimated: slope of F-P (minimal renal vascular resistance reflecting overall luminal dimensions of preglomerular and postglomerular vasculature), slope of P-GFR (glomerular filtration capability against pressure), and threshold pressure for beginning filtration at P-GFR (preglomerular-to-postglomerular vascular resistance ratio). Thereafter, maximal renal vascular resistance was determined to assess wall-to-lumen ratios of the resistance vessels in half of each group. In the remainder, the kidneys were perfusion-fixed for histological analysis. Mean arterial pressure did not differ between the DS and DR rats. There were no significant differences in the slopes of F-P between the 2 groups. In contrast, the slope of P-GFR was significantly lower (33%) in DS rats than in DR rats, although the DS kidneys began filtering at a threshold pressure similar to that of the DR kidneys. Thus, in DS rats, there were no abnormalities in luminal dimensions at preglomerular and postglomerular vascular segments, but the kidney filtration capacity decreased at any given increase in pressure. Maximal vascular resistance was greater in DS than in DR rats, a finding compatible with the histological appearance, which showed vascular hypertrophy with little, if any, vascular narrowing in the interlobular arteries of DS rats. In conclusion, hypertrophic remodeling without vascular narrowing at preglomerular resistance vessels and structural defects in filtering at the glomeruli could occur in prehypertensive DS rats.

Animals↗
PubMed2000

Nitric oxide synthase inhibitors attenuate ozone-induced airway inflammation in guinea pigs. Possible role of interleukin-8.

Nitric oxide (NO) is increased in exhaled air of asthmatics. We hypothesized that endogenous NO contributes to airway inflammation and hyperresponsiveness, and that interleukin-8 (IL-8) might be involved in this mechanism. In human transformed bronchial epithelial cells in vitro, NO donors increased IL-8 production dose-dependently. In addition, tumor necrosis factor-alpha (TNF-alpha) plus IL-1beta plus interferon-gamma (IFN-gamma) increased IL-8 in culture supernatant of epithelial cells; the combination of NO synthase (NOS) inhibitors, aminoguanidine (AG) plus N(G)-nitro-L-arginine methyl ester (L-NAME) attenuated the cytokine-induced IL-8 production in epithelial cells. In guinea pigs in vivo, ozone exposure induced airway hyperresponsiveness to acetylcholine and increased neutrophils in bronchoalveolar lavage fluid (BALF), and these changes persisted for at least 5 h. Pretreatment with NOS inhibitors had no effect on airway hyperresponsiveness or neutrophil accumulation immediately after ozone, but significantly inhibited the changes 5 h after ozone. NOS inhibitors also attenuated the increases of nitrite/nitrate levels in BALF and the IL-8 mRNA expression in epithelial cells and in neutrophils in guinea pig airways 5 h after ozone. These results suggest that endogenous NO may play an important role in the persistent airway inflammation and hyperresponsiveness after ozone exposure, presumably partly through the upregulation of IL-8.

Acetylcholine↗
PubMed2000

Inhibition of binding of E- and P-selectin to sialyl-Lewis X molecule suppresses the inflammatory response in hypersensitivity pneumonitis in mice.

The carbohydrate structure of sialyl-Lewis X (SLe(x)) can function as a ligand for E- and P-selectin, which play important roles in mediating the initial interactions of leukocytes with the endothelium in inflammatory responses. In this study we evaluated the effects of inhibiting E- and P-selectin function with the SLe(x) molecule on the inflammatory response in an experimental murine model of hypersensitivity pneumonitis (HP). Antigen exposure induced marked interstitial and especially perivascular and peribronchiolar infiltration with lymphocytes and granuloma formation, in murine lung sensitized with Saccaropolyspora rectivirgula. These pathologic changes were significantly suppressed with SLe(x) ganglioside analogues through a reduction in the numbers of lymphocytes in bronchoalveolar lavage fluid, as evidenced by the lung index and histologic scores indicating the severity of the inflammatory response. Using specific antibodies, we also evaluated the immunohistochemical localization of SLe(x) in mononuclear cells in granulomas, and of E- and P-selectin in vascular endothelium. Our findings suggest that the molecular interaction between SLe(x), and E- and P-selectin mediates lymphocyte recruitment into the lung parenchyma, which is critical for the inflammatory response in experimental murine models of HP.

Alveolitis, Extrinsic Allergic↗
PubMed2000

Effect of eotaxin and platelet-activating factor on airway inflammation and hyperresponsiveness in guinea pigs in vivo.

Although eotaxin causes selective infiltration of eosinophils into the lung, its role in airway hyperresponsiveness remains unclear. We studied the effects of local administration of eotaxin on airway inflammation and hyperresponsiveness in guinea pigs in vivo. Airway responsiveness to inhaled histamine and differential cell counts in bronchoalveolar lavage fluid (BALF) were evaluated 12 h, 24 h, 3 d, and 7 d after intratracheal instillation of eotaxin. Significant eosinophilia in BALF was observed between 6 h and 7 d after eotaxin administration. Histologically, eosinophil accumulation was observed in the airways but not in the alveoli. In contrast, eotaxin did not affect airway responsiveness between 12 h and 7 d after its administration. We then studied the effects on airway responsiveness of subthreshold doses of interleukin 5, leukotriene D(4) (LTD(4)), and platelet-activating factor (PAF) combined with eotaxin. Neither interleukin 5 nor LTD(4) affected airway responsiveness. After eotaxin treatment, PAF significantly enhanced airway responsiveness without further increases in eosinophil counts. Eotaxin plus PAF significantly increased in eosinophil peroxidase activity in BALF compared with control and with eotaxin alone. These data indicate that eotaxin alone causes eosinophil accumulation in the airways but not hyperresponsiveness, and that additional factors such as PAF are needed to activate eosinophils for the development of airway hyperresponsiveness.

Animals↗
PubMed2000

Coronary artery-left ventricle fistula complicating balloon angioplasty--a case report.

The authors describe a coronary artery fistula complicated balloon angioplasty. The proximal left anterior descending coronary artery was dilated, but a septal branch was occluded by thrombus. Angioplasty was used on the septal branch, but a pseudoaneurysm communicating with the left ventricle occurred. Follow-up angiography revealed spontaneous closure of the fistula.

Aged↗
PubMed2000

Phosphorylation of D-glucose derivatives with inorganic cyclo-triphosphate: substituent effect at the 5-CH2OH or 2-OH group.

The phosphorylation of several D-glucose derivatives has been achieved using inorganic sodium cyclo-triphosphate hexahydrate (P3m), Na3P3O9 x 6H2O, in aqueous solution. In the phosphorylation of D-glucuronic acid, 6-phosphoryl-D-glucose and D-xylose, beta-D-glucuronic acid 1-triphosphate, 6-phosphoryl-beta-D-glucose 1-triphosphate and beta-D-xylose 1-triphosphate were synthesized stereoselectively with maximum yields of 43.5, 32.8 and 41.9%, respectively. In the case of D-glucosamine and 2-deoxy-D-glucose, the main phosphorylated products were assigned to beta-D-glucosamine 1-triphosphate and 2-deoxy-beta-D-glucose 1-triphosphate by 1H-, 13C- and 31P-NMR, and the yields were 13.9 and 13.4%, respectively.

Carbohydrate Conformation↗
PubMed2000

Protective effect of TA-993, a novel therapeutic agent for peripheral circulatory insufficiency, on skeletal muscle fatigue in a rat model of hindlimb ischemia.

TA-993 (cis-(-)-2-(4-methylphenyl)-3-acetoxy-2,3-dihydro-5-(2-dimethylaminoethy l)-8-methyl1,5-benzothiazepine-4(5H)-one maleate), a new 1,5-benzothiazepine derivative, has a selective increasing action on limb blood flow in addition to an antiplatelet action. In this report we studied the effect of TA-993 on a time dependent decrease in developed tension of electrically-induced contraction of tibialis anterior muscle in a rat model of peripheral circulatory insufficiency induced by occlusion of abdominal aorta. In our preparation, the developed tension decreased by 20-30% in a sham-operated group and 30-40% in an abdominal aorta-occluded group at the end of the experimental period of 60 min. Intraduodenal administration (i.d.) of TA-993 (10 mg/kg) to the abdominal aorta-occluded rats ameliorated the decrease in developed tension to the level of the sham-operated group. Moreover, TA-993 at 10 mg/kg, i.d. significantly increased femoral arterial blood flow supplied through collateral circulation and decreased the whole blood viscosity in this model. These results suggest that TA-993 improves dysfunction of skeletal muscle contraction due to peripheral circulating insufficiency through an increase in collateral blood flow and an improvement of red blood cell deformability.

Animals↗
PubMed2000

Role of tyrosine 114 of L-methionine gamma-lyase from Pseudomonas putida.

L-Methionine gamma-lyase from Pseudomonas putida has a conserved tyrosine residue (Tyr114) in the active site as in all known sequences of y-family pyridoxal 5'-phosphate dependent enzymes. A mutant form of L-methionine y-lyase in which Tyr114 was replaced by phenylalanine (Y114F) resulted in 910-fold decrease in kcat for alpha,gamma-elimination of L-methionine, while the Km remained the same as the wild type enzyme. The Y114F mutant had the reduced kcat by only 28- and 16-fold for substrates with an electron-withdrawing group at the gamma-position, namely O-acetyl-L-homoserine and L-methionine sulfone, respectively, and also the similar reduction of kcat for alpha,beta-elimination and deamination substrates. The hydrogen exchange reactions of substrate and the spectral changes of the substrate-enzyme complex catalyzed by the mutant enzyme suggested that gamma-elimination process for L-methionine is the rate-limiting determination step in alpha,gamma-elimination overall reaction of the Y114F mutant. These results indicate that Tyr114 of L-methionine gamma-lyase is important in y-elimination of the substrate.

Carbon-Sulfur Lyases↗
PubMed2000

Plasma renin activities, angiotensin II concentrations, atrial natriuretic peptide concentrations and cardiopulmonary function values in dogs with severe heartworm disease.

Relationships among plasma renin activities (PRA), plasma angiotensin II (ATII) concentrations, atrial natriuretic peptide (ANP) concentrations and cardiopulmonary function values were examined in dogs with ascitic pulmonary heartworm disease and acute- and chronic-vena caval syndrome (CS). PRA, plasma ATII concentration and plasma ANP concentration tended to be higher or were significantly higher in dogs with ascites, acute- and chronic-CS. PRA correlated significantly with plasma ATII concentration, WBC count, ALP activity, plasma concentrations of urea nitrogen, creatinine, sodium, potassium, and chloride, right ventricular endodiastolic pressure and right atrial pressure. Plasma ATII concentration correlated significantly with WBC count, plasma concentrations of urea nitrogen, sodium, and potassium, right ventricular endodiastolic pressure and right atrial pressure. Plasma ANP concentration did not correlate with PRA or ATII concentration, but correlated significantly only with pulmonary arterial pressure.

Angiotensin II↗
PubMed2000

Gait characteristics of patients after proximal femoral replacement for malignant bone tumour.

We analysed the gait characteristics of 15 patients with prosthetic reconstruction of the proximal femur after resection of a malignant bone tumour using stride analysis and measurement of oxygen consumption. Compared with normal volunteers their gait was slower, with less cadence and reduced stride length. The mean net energy cost of free walking was 141% of normal. The degree of asymmetry of the single-limb support time correlated with the free-walking velocity and the net energy cost. If they used a single cane the subjects walked with less cadence, longer stride length, and prolonged single-limb support times. The net energy cost of walking and asymmetry of the single-limb support time had a negative correlation with the strength of the hip abductor muscles. Their walking performance was better than that of six subjects who had hip disarticulation.

Adolescent↗
PubMed2000

Effects of esophageal acid perfusion on airway hyperresponsiveness in patients with bronchial asthma.

STUDY OBJECTIVES: The effects of gastroesophageal reflux on airway hyperresponsiveness in patients with bronchial asthma have yet to be studied in significant detail. The purpose of the present study was to determine how esophageal acid perfusion could change airway responsiveness in patients with bronchial asthma. PATIENTS AND INTERVENTIONS: In seven patients with bronchial asthma (mean +/- SD age, 55.1 +/- 6.4 years; four women and three men), esophageal pH was monitored by a pH meter and airway responsiveness was evaluated by aerosol inhalation of methacholine, during esophageal perfusion through an esophageal tube filled with either saline solution or 0. 1N hydrochloric acid (HCl), the order of which was selected at random, in 1-week intervals. Spirometry was also performed during esophageal pH monitoring. RESULTS: A significant decrease in the geometric mean of airway sensitivity or the concentration of methacholine causing a 35% fall in respiratory conductance was observed during esophageal HCl perfusion compared with that of saline solution perfusion (p < 0.01 or p < 0.003), although no significant changes were observed in vital capacity, FEV(1), peak expiratory flow, respiratory resistance, or slope of respiratory conductance during the periods of saline solution and HCl perfusion. CONCLUSION: We concluded that an increase in airway hyperresponsiveness was induced when HCl stimulated the esophagus in patients with bronchial asthma. These results suggest that esophageal reflux is one of the important factors that aggravate asthmatic status.

Adult↗
PubMed2000

Rupture of a giant saccular aneurysm of coronary arteriovenous fistulas.

A 58-year-old Japanese woman was admitted to our hospital because of chest pain. A continuous murmur was detected at the left parasternal area. Electrocardiogram showed ST elevation in leads V2, V3 and V4. Chest computed tomography and echocardiography demonstrated pericardial effusion and a large mass which was adjacent to the pulmonary artery. An abnormal blood flow was detected in the mass by Doppler echocardiography. Coronary angiography confirmed that the mass was a giant aneurysm of coronary arteriovenous fistula arising from both the left and right coronary arteries. This patient had no symptoms until rupture of the fistula. Rupture of a coronary arteriovenous fistula is very rare but can be a cause of chest pain and pericardial effusion.

Aneurysm, Ruptured↗
PubMed2000

Increased osteocyte apoptosis during the development of femoral head osteonecrosis in spontaneously hypertensive rats.

We investigated the presence of osteocyte apoptosis in the necrotic trabeculae of the femoral head of spontaneously hypertensive rat (SHR) using the in situ nick end labeling (TUNEL) method and transmission electron microscopy. The occurrence of osteonecrosis and ossification disturbance was significantly higher in SHR compared with Wistar Kyoto (WKY) rats, and Wistar (WT) rats used as control animals (P < 0.01). A high population of TUNEL positive osteocytes was detected mainly in 10- and 15-week-old SHRs. Sectioned examination of the femoral head of SHRs and WKY rats by electron microscopy revealed apoptotic cell appearances such as aggregation of chromatin particles and lipid formation. In contrast, a positive reaction was significantly lower in osteocytes in the femoral heads of WT rats (P < 0.01). Our results indicate that apoptosis forms an important component of the global pathologic process affecting the femoral head of SHR, which leads to osteonecrosis in this region.

Animals↗