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Biomedical subjects

M Hirota

Publications and source records attributed to M Hirota.

At least 145 records · Page 8Linked to original sources
PubMed1990

Inhibition of stress-induced gastric mucosal injury by a long acting superoxide dismutase that circulates bound to albumin.

To determine whether oxygen-derived free radicals play an important role in the pathogenesis of stress-induced tissue injury, the effect of a superoxide dismutase derivative, which binds to albumin and circulates with a half-life of 6 h in intact rats, on acute gastric mucosal lesion was observed in rats which were given water-immersion-restraint. This enzyme derivative also circulated bound to albumin with a half-life of 8 h in rats which were challenged with water-immersion-restraint. This treatment significantly perturbed systemic circulation of animals by decreasing the effective volume of circulating blood, increased vascular permeability of the gastric mucosa, and induced acute gastric mucosal lesion. Intravenous administration of this enzyme derivative normalized both systemic circulation and vascular permeability of the gastric mucosa and prevented the occurrence of stress-induced gastric injury. These findings suggest that the superoxide radical and/or its metabolite(s) plays an important role in the pathogenesis of stress-induced acute gastric mucosal lesion.

Animals↗
PubMed1990

Suppression of synthesis and release of glucagon by glucagon-like peptide-1 (7-36 amide) without affect on mRNA level in isolated rat islets.

Glucagon-like peptide-1 (GLP-1) has been reported to inhibit glucagon release. To investigate the mechanism involved, we examined the effects of GLP-1 on the preproglucagon mRNA level and the content and release of glucagon in the isolated rat islets. Arginine significantly increased the content and release of glucagon after incubation for 1 h or 18 h. The preproglucagon mRNA level was not increased after incubation for 1 h but was increased after incubation for 18 h. GLP-1 (7-36 amide) significantly decreased the content and release of glucagon after incubation for 1 h or 18 h, but did not affect arginine-induced increase in the preproglucagon mRNA level after incubation for 18 h. These data suggest that GLP-1 suppresses post-transcriptional processes in the content and release of glucagon.

Animals↗
PubMed1990

Differences in lipid composition between isolated growth cones from the forebrain and those from the brainstem in the fetal rat.

The lipid composition of nerve growth cone membranes isolated from rat fetal forebrain or brainstem by the sucrose density gradient method was analyzed biochemically and immunochemically. In the forebrain, growth cone membrane (GCM) contained lower levels of gangliosides than those from other heavier fractions, but it was not the case in the fetal brainstem at the same developmental stage. The distinctive features in the ganglioside composition of GCM are the predominance of GD3 and the presence of c-series gangliosides that are due to fetal expression in mammals. A unique acidic glycolipid, sulfoglucuronylparagloboside (SGPG), which is not present in adult brains, was first detected in both forebrain and brainstem GCM. Including such minor species, the ganglioside composition in forebrain or brainstem GCM was almost identical to other membrane fractions from the forebrain or brainstem. The compositional ratios of the major lipid classes in membranes, cholesterol and phospholipids, seemed to be common to forebrain GCM and brainstem GCM, as indicated by the identical values of phospholipid-to-protein (PL/Pr), cholesterol-to-protein (Ch/Pr), and cholesterol-to-phospholipid (Ch/PL) ratios for both. This study has revealed that GCM isolated from forebrain which is supposed to be at an earlier stage of neuronal differentiation than brainstem has less amounts of total gangliosides, high proportion of GD3 to GD1a and enriched c-series gangliosides as compared to brainstem GCM.

Animals↗
PubMed1990

Development of an eye-movement analyser possessing functions for wireless transmission and autocalibration.

An eye pointer was developed as a new line-of-sight displacement analyser. It analyses an observer's eye movements and superimposes their line of vision on a TV image which is the same as their view. A newly developed miniature colour field camera and very compact eye-movement sensors are attached to a translucent reinforced plastic goggle affording a wide view and excellent safety. A small case is provided for the eye-movement detecting circuit and the camera controller unit etc. Its weight is only 1.2 kg and one can easily participate in sports activities while wearing it. Eye-movement data are transmitted with the VHF video signal. The receiver, which analyses the eye movements and processes the TV image, is also compact and easy to carry. The calibration is automatic and completed within 1 min with a high degree of accuracy. By showing the tennis player's line of vision as an example, we were able to obtain good results with application in broadcasting programmes.

Eye Movements↗
PubMed1990

Metabolism of intravenously administered maltose in renal tubules in humans.

To investigate how urinary excretion rates (UERs) of maltose and glucose are determined after intravenous maltose infusion, maltose and glucose solutions were infused at various rates and the relationships between UERs of maltose and glucose and their plasma concentrations were examined. Results showed the existence of a threshold plasma maltose concentration for the urinary excretions of maltose and glucose and the existence of a maximum rate of urinary glucose excretion after maltose infusion. Elevation of plasma glucose concentration by simultaneous glucose infusion increased urinary glucose excretion but did not increase urinary maltose excretion; the relationship between plasma total sugar concentration and urinary total sugar excretion was unchanged. Results suggest that maltose administered intravenously is hydrolyzed to glucose by maltase in renal tubules and reabsorbed as glucose competitively with glucose derived from plasma and that the maximum utilization of intravenously infused maltose is determined by the tubular glucose reabsorption capacity.

Adult↗
PubMed1990

[Investigation on the etiology of sepsis by using experimental mouse model with leukocytopenia. 3. The role of Kupffer cells in the etiology of bacteremia].

In the previous report, we showed that the reticuloendothelial system (RES), especially the liver, played an important role in the etiology of bacteremia or sepsis as the major protective system. In this study, to investigate the role of Kupffer cells in the etiology of bacteremia, we isolated and cultured murine Kupffer cells using a technique involving perfusion with collagenase and DNase. We compared the adherence and phagocytosis rate of two groups of isolated bacteria from bacteremic mice by these cells. One group was bacteria causing systemic bacteremia consisted of P. aeruginosa and M. morganii, and the other was bacteria causing portal bacteremia consisted of E. coli, E. cloacae, K. pneumoniae and Enterococci. As a consequence, the following facts were revealed. 1. The bacterial phagocytosis and adherence rate by Kupffer cells were significantly higher in bacteria causing portal bacteremia than in bacteria causing systemic bacteremia. These data were correlated to each blood clearance rate from mice. 2. Blood clearance rate reflected mainly adherence of Kupffer cells to bacteria, and it was suggested that these adherence were one of the most important factor to protect the hosts from the advance of bacteremia from the portal to the systemic. 3. In the case of using peritoneal macrophage, we couldn't find the same correlation, so the possibility was suggested that the above phenomenon was specific to Kupffer cells.

Animals↗
PubMed1990

[Clinical and bacteriological studies in four cases of pulmonary infection caused by Protomonas extorquens].

A novel bacterium, Protomonas extorquens was isolated from sputum, pleural effusion and ascitis in four cases of pulmonary infection by buffered charcoal yeast extract agar (B-CYE) which was generally used for Legionella spp. Three cases were so-called immunocompromised hosts (2 malignant diseases, 1 renal failure), and they died from underlying diseases. Protomonas extorquens was newly named by Komagata in 1984, which was characterized by production of pink pigment, growth in methanol medium and positive production of oxidase and catalase. This organism is ordinarily isolated from soil and dead leaves. This is the first report for isolation of P. extorquens from clinical specimens in Japan and it seems to have a significant role in immunocompromised hosts.

Adult↗
PubMed1990

[Isolation of methicillin-resistant Staphylococcus aureus (MRSA) at the Hokusho Central Hospital--observation during the recent 4 years].

Clinical and bacteriological studies were carried out to investigate the isolation of MRSA from clinical materials, during the 4 years from 1985 to 1988 at the Hokusho Central Hospital. The isolation frequency of MRSA from Staphylococcus aureus increased from 5.6% (3 strains) in 1985 to 50.0% (90 strains) in 1988. MRSA from sputum and pressure sore increased significantly. However MRSA from outpatient and inpatient in the ward for common people were constant, about 20%. Inpatients in the ward for aged person were increased significantly from 13.6% (3 strains) to 67.0% (67 strains). Most of the patients with positive MRSA isolation had background diseases (88.3%) and were bedridden (78.4%). Patients with cerebrovascular disease were 55.9% of all of the cases. But most of the MRSA strains were resistant to CZX, FOM, DMPPC, CMX, CEZ, CZON, CZX, most of the MRSA strains were sensitive to RFP, VCM, MINO, IPM/CS.

Anti-Bacterial Agents↗
PubMed1990

[Studies on defence effects of recombinant human granulocyte colony-stimulating factor (G-CSF) to infections. I. Induction of neutrophil polarization by G-CSF].

It is well known that recombinant human granulocyte increases dramatically the number of granulocytes in peripheral blood. It is interesting to see if G-CSF enhances the functions of neutrophil since the neutrophil is one of the most important factors of host defence mechanism against infections. In this study, we have demonstrated that G-CSF induced the polarization of neutrophil while it could not be chemoattractant for the cell. Polarization is considered to be the initial reaction of chemotaxis. Therefore, G-CSF might enhance the defence effect of the neutrophils+ to infections in this point.

Cells, Cultured↗
PubMed1990

[Studies on defense effects of recombinant human granulocyte colony-stimulating factor (G-CSF) to infections. II. Priming effect for superoxide production by human neutrophil].

In present study, we have investigated superoxide (O2-) production from human neutrophils by recombinant human granulocyte colony-stimulating factor (G-CSF) using the microtiter plate for the purpose of being close to the inflammatory site. G-CSF by itself did not induce the release of O2- in human neutrophil on either Fetal Bovine Serum (FBS)-coated plate or plate uncoated with FBS, even if neutrophils were exposed for maximum 3 hr. However, the optimal concentration of G-CSF (50 ng/ml) was able to prime human neutrophils with enhance of O2- release stimulated by the chemotactic peptide, N-formyl-methionyl-leucyl-phenylalanine (FMLP) from 10(-6) to 10(-8) M, but not by the non chemoattractant such as phorbol myristate acetate (PMA), concanavalin A, and ionomycin. These findings indicate that G-CSF might enhance bactericidal activity of neutrophils by priming them penetrating into the inflammatory site.

Cells, Cultured↗
PubMed1990

[Comparison of D-arabinitol, candida antigen, and beta-glucan, measured by the chromogenic limulus assay, in the rabbit model of systemic candidiasis].

In this study, we measured D-arabinitol, candida antigen and beta-glucan in the rabbit model of systemic candidiasis. It was recently reported that the factor G, one of the coagulation enzymes from the horseshoe crad amebocyte lysate, reacts with beta-glucan or polysaccharide from fungus, and not with endotoxin. The newly developed endotoxin specific chromogenic Limulus assay (endospecy test), which is devoid of factor G, did not react with any rabbit serum. But the beta-glucan measured by the conventional Limulus assay (toxicolor test), which contains the factor G, was elevated (from 10 pg/ml to 100 pg/ml) in all cases of rabbit model of system candidiasis. Serum D-arabinitol, measured by Sone's enzymatic fluorometric method, increased in all cases, but Cand-Tec (candida detection system by latex agglutination) showed only one positive case in five innoculated rabbits.

Animals↗
PubMed1990

[Studies on defence effects of recombinant human granulocyte colony-stimulating factor (G-CSF) to infections. III. Protective effect on pulmonary and systemic infections of P. aeruginosa in neutropenic mice].

In the prior two reports, we demonstrated that G-CSF induced the polarization of neutrophils by itself, and also enhanced superoxide production from neutrophils stimulated by the chemotactic peptides. In this study, we have examined the protective effect of G-CSF in vivo on Pseudomonas pneumonia and septicemia in mice. Cyclophosphamide (CY) induced severe reduction of the number of peripheral leukocytes and weakened resistance for Psuedomonas aeruguinosa infection of mice. However, in mice receiving recombinant human G-CSF four daily subcutaneous injection, the number of leukocytes, particulary neutrophils, increased more rapidly than in controls receiving saline. Moreover G-CSF enhanced a protective effect to pulmonary and systemic pseudomonas infections. When G-CSF was administered together with antibiotics, significant synergism in the protection against pulmonary infection of Pseudomonas was observed. Carrageenan treatment decreased the protective effect of G-CSF. These results suggested that the protective effect of G-CSF against P. aeruginosa infection depends not only on PMN but also another complexed host defence mechanism.

Animals↗
PubMed1990

[Isolation of Branhamella catarrhalis from sputum and clinical features of bronchopulmonary infection due to Branhamella catarrhalis].

The authors investigated the isolation of Branhamella catarrhalis from sputum and the clinical features of bronchopulmonary infection due to B. catarrhalis from January of 1983 to December of 1987 at the Hokusyo Central Hospital. B. catarrhalis was cultured from 106 (3.8%) of 5,674 sputum specimens. The isolation rate did not vary during the 5 years from 1983 to 1987. Approximately 70% of the patients had some underlying bronchopulmonary disease. The strains of beta-lactamase-positive B. catarrhalis have increased recently in our hospital. Using 4 diagnostic criteria for bronchopulmonary infection by B. catarrhalis, 24 cases were detected. MIC was measured in 97 strains of B. catarrhalis (beta-lactamase positive 63 strains, negative 34 strains). beta-lactamase positive strains had a high MIC value for beta-lactam antibiotics, but antibiotics including beta-lactamase inhibitor markedly improved sensitivity to drugs. Negative strains showed good sensitivity to beta-lactam antibiotics. Cases of bronchopulmonary infection due to Branhamella catarrhalis and beta-lactamase-productive strains are increasing, therefore it is necessary to be careful in the choice of antibiotics.

Aged↗
PubMed1990

[Adverse reactions of antituberculous agents, especially about its onset and duration].

We examined the adverse reactions of the antituberculous agents in 225 hospitalized patients (150: male, 75: female, average age: 45.4 years old) and the results were summarized as follows: 1) The side effects were seen in 53 patients (23.6%), and the abnormal laboratory findings were observed in 94 patients (41.8%). 2) The incidence of adverse reactions in patients treated with three drugs (INH, RFP, EB) and four drugs (plus SM) were 45.9% and 82.4%, respectively. 3) Adverse reaction appeared within one month after starting treatment in 67.9% of eligible patients, and it disappeared within one month from its onset in 76.8% of patients. There results suggested the importance of careful clinical observation especially soon after starting antituberculous therapy.

Aged↗
PubMed1990

[A case of Aspergillus empyema with bronchopleural fistula].

Pleural aspergillosis is not a common disease and we recently experienced a case of Aspergillus empyema with bronchopleural fistula. A 76 year-old man was admitted to our hospital with productive cough and fever. Chest X-ray films showed infiltration in the right lower and left middle field and rather lucent area (clearing) in the right lower lung. Antibiotic therapy was administered but no improvement was obtained. Chest CT scan and right bronchography revealed empyema in the right back portion and bronchopleural fistula in the right lower lobe. Needle aspiration biopsy was performed and Aspergillus fumigatus was isolated from pus. A diagnosis of Aspergillus empyema with bronchopleural fistula was made. We began intrapleural administration of miconazole and empyema was improved partially. For the complete treatment, right lower lobectomy and decortication were performed, but unfortunately he died of acute pneumonia 16 days after operation.

Aged↗
PubMed1990

[A case of idiopathic pulmonary fibrosis with chronic eosinophilic pneumonia].

A 58 year-old man was admitted to our hospital with complaints of dyspnea and cough. Chest X-ray examination revealed diffuse nodular shadow, infiltration in the left upper and lower lobes, and volume loss. BALF showed increased number of cells, particularly eosinophils (65.6%). Eosinophilia (17-13%) was also seen. The histological examination of the TBLB specimen revealed irregular thickening and edema of alveolar septa. From these findings together with clinical features the case was diagnosed as eosinophilic pneumonia. Oral administration of prednisolone started with 30 mg. Within a week, eosinophilia in peripheral blood decreased to 1%, PaO2 increased to 87.5 Torr in room air, and CRP became negative. His chest X-ray film showed the disappearance of infiltrative shadows in the left upper and lower lobes. On the 19th day was prednisolone decreased to 20 mg. Laboratory data and chest roentgenogram showed exacerbation, and PaO2 gradually decreased to 62.9 Torr. Patchy shadows were seen in the right upper lobe. The dose of prednisolone was again increased to 60 mg/day, and was quite effective. The drug dosage was tapered by 10 mg/10 days to 40 mg/day, however all data exacerbated again. The clinical course seemed peculiar for eosinophilic pneumonia, however small reticulonodular shadows on chest X-ray did not change. Therefore, open lung biopsy was performed. The histology of the specimen showed fibrosis, lymphocyte infiltration and thickening of alveolar septa. The clinical course and histopathological findings led to a diagnosis of idiopathic pulmonary fibrosis accompanied with chronic eosinophilic pneumonia.

Biopsy↗