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Biomedical subjects

S Kojima

Publications and source records attributed to S Kojima.

At least 901 records · Page 50Linked to original sources
PubMed1985

Novel plasmin inhibitors released from bovine platelets during aggregation.

The antifibrinolytic activity was found in the medium of platelet suspension in the process of platelet aggregation induced by thrombin, ADP and 5-hydroxytryptamine. The antifibrinolytic activity was closely associated with inhibitors in platelets, which specifically inhibited plasmin activity and not inhibited other proteases such as urokinase, thrombin and trypsin. One casein unit of plasmin activity was inhibited by the inhibitors released from approximately 10(8) platelets during the aggregation with thrombin. By the activity staining analysis, it was found that there are two kinds of plasmin inhibitors with molecular weights of 25,000 and 17,000. The physiological function of these inhibitors was discussed in relation to the formation of thrombus.

Adenosine Diphosphate↗
PubMed1985

Synergism of vitamins A and C on fibrinolysis.

A hitherto unknown synergism exerted by retinol (vitamin A) and L-ascorbic acid (vitamin C) was discovered using endothelial cells. Retinol stimulated the extracellular and intracellular activities of plasminogen activator up to approximately 8- and 4-fold from the control values, respectively. L-Ascorbic acid enhanced the extracellular and intracellular activities up to approximately 1.5-fold. Above all it was demonstrated that their effects on extracellular activity were synergistic; simultaneous administration of these two vitamins enhanced the extracellular activity up to a 20- to 50-fold. Synthesis of plasminogen activator induced with vitamins A and C was inhibited by a protein synthesis inhibitor, cycloheximide.

Animals↗
PubMed1985

Involvement of heparan sulfate in 67Ga binding to rat-liver plasma membrane.

The role of heparan sulfate (HS) in gallium citrate Ga 67 binding to rat-liver plasma membrane was investigated. HS was found to be the only acid mucopolysaccharide present on the plasma-membrane surface. The extent of 67Ga binding to the plasma membrane reached a plateau 1-2 h after the start of incubation, and binding was higher under alkaline conditions than under acidic conditions. The amount of binding increased in parallel with the protein concentration of the plasma membrane (up to 2 mg per incubation mixture). Solubilizing agents, such as bromelin and 1% Triton X-100 as well as 2 M NaCl and heparin, markedly decreased 67Ga binding, and the decrease in 67Ga binding to the plasma membrane was closely associated with the amount of HS released from the plasma-membrane surface by each solubilizing agent. On the other hand, treatment with HS markedly increased 67Ga binding to about three times the control level. These data provide further support for our previous proposal that HS plays an important role as a receptor for gallium in various tissues, including tumor cells and inflammatory tissues.

Animals↗
PubMed1985

In vitro binding of 67Ga to isolated rat liver cells.

In order to understand the mechanism of the accumulation of gallium citrate (Ga-67) in normal liver, an in vitro investigation system was developed using isolated rat liver cells, and various basal factors relating to 67Ga binding to normal rat liver cells were studied. In this study, the values of 67Ga binding to the liver cells increased in parallel with the number of cells; however, binding was hardly affected by higher doses of 67Ga. The binding of 67Ga to the cells was inhibited by the presence of ethylenediaminetetraacetate (EDTA) and citrate. Phosphate and bicarbonate (10(-2) M) slightly inhibited 67Ga binding to the cells. The binding of 67Ga to the cells increased as the pH was decreased. These results suggest that 67Ga binding to normal rat liver cells may occur in 'free' gallium. Moreover, the utilization of isolated rat liver cells is useful for understanding the 67Ga accumulation mechanism in normal liver.

Animals↗
PubMed1985

Changes in left ventricular diastolic function after left ventriculography: a comparison with iopamidol and urografin.

Changes in left ventricular (LV) diastolic indices after left ventriculography (LVG) with iopamidol or urografin were studied in 42 subjects. Increase in heart rate and decrease in LV systolic pressure were more significant with urografin than with iopamidol (p less than 0.05 to 0.001). LV end-diastolic pressure was elevated more with urografin than with iopamidol (p less than 0.005 to 0.05) 1 to 3 minutes after LVG. LV peak negative dP/dt decreased significantly with urografin immediately (10 to 15 seconds, -511 and 30 seconds, -376 mm Hg/sec; p less than 0.0005 to 0.02), but with iopamidol it did not decrease significantly after LVG. Time constant, T, was elongated with iopamidol (10 to 15 seconds, +13 and 30 seconds, +6 msec; p less than 0.0005), but this elongation was significantly less than urografin (10 to 15 seconds, +34; 30 seconds, +25; 1 minute, +15; and 2 minutes, +10 msec; p less than 0.05 to 0.0005). We conclude that iopamidol disturbed LV diastolic function to a lesser degree than did urografin.

Adult↗
PubMed1985

Renal gallium accumulation in mice with acute immune complex glomerulonephritis.

67Ga uptake and heparan sulfate (HS) content were investigated during the recovery of mouse kidney from acute immune complex glomerulonephritis induced by daily injections of bovine serum, and the binding of 67Ga to glomerular basement membrane (GBM) was studied in vitro. The results were as follows. 67Ga uptake in the kidney increased after the start of bovine serum injection, and peaked on the 20th day. The uronic acid content in 1.2 M NaCl-soluble fraction (which contained predominantly HS) and the hydroxyproline content (an index of collagen) were increased at the 10th day, reaching a maximum at the 20th day. This pattern of HS content was essentially the same as that of 67Ga accumulation in the kidney. Urinary protein and gamma-GTP activity peaked at the 5th day, and these patterns were different from that of 67Ga uptake. 67Ga binding to GBM was significantly inhibited by treatments with HS-degrading enzyme (heparitinase), nitrous acid, trypsin or papain. However, the binding to GBM was unaffected by treatment with chondroitinase ABC. These results provide further evidence that the 67Ga-binding substance in tumor tissues and inflammatory lesions is probably HS.

Acute Disease↗
PubMed1985

Effects of three proteins on absorption of cadmium in rats.

The effects of 3 proteins on the gastrointestinal absorption of cadmium were studied. Glycinin and ovalbumin significantly decreased cadmium in liver and the total cadmium in the tissues of rats following a single oral administration of cadmium. In addition, in rats fed continuously with the experimental diets containing cadmium together with proteins, glycinin and ovalbumin significantly decreased the contents of cadmium in the tissues. These results show that the proteins depressed the gastrointestinal absorption of cadmium. Moreover, the effects of cadmium on various digestive enzymes for proteins and the pepsin or pepsin-pancreatin digestion of the proteins were examined. As a result it is likely that the inhibitory effect of cadmium on the intestinal digestion of these proteins is one of the causes of the inhibitory effects of the proteins on the intestinal absorption of cadmium in rats. The undigested oligopeptides may decrease the amount of free cadmium available to be absorbed from the intestine by binding cadmium itself, resulting in decreased intestinal absorption of cadmium.

Animals↗
PubMed1985

Naphthol AS as a cause of pigmented contact dermatitis.

Naphthol AS is a coupling agent of cotton dyeing. 2 elderly women with hyperpigmentation of the neck and limbs are described. Both felt itching on the neck, forearms, and lower extremities and noted hyperpigmentation a month later. Both had worn cotton flannel nightdresses in winter. Patch testing with cotton flannel and methanol extracts were positive, but after estraction with methanol, the residual flannel did not react. The methanol extracts of cotton flannel, were analysed. The patients were tested with 5 extracted components; Naphthol AS was found to be the causative agent.

Coloring Agents↗
PubMed1985

Enhancement of IgE-dependent eosinophil cytotoxicity to dinitrophenylated schistosomula by a nematode infection.

In order to obtain direct evidence for the involvement of IgE in the eosinophil-mediated cytotoxicity, dinitrophenylated (DNP) schistosomula of Schistosoma japonicum coated with monoclonal IgE antibodies were examined as to whether they were killed by rat peritoneal eosinophils. The results indicated that the cytotoxicity of the eosinophils was dependent on a mouse monoclonal anti-DNP IgE antibody, but not on another monoclonal antibody specific to ovalbumin. Moreover, an enhanced cytotoxicity was observed when eosinophils were obtained from rats 4 weeks after infection with Nippostrongylus brasiliensis.

Animals↗
PubMed1985

Alterations in myocardial perfusion during painless ST-segment depression in patients with angina pectoris.

In order to determine whether painless ST changes represent myocardial ischemia, we studied regional myocardial perfusion in patients with angina pectoris who showed painless ST-segment depression during a treadmill exercise test. Twenty-one patients were evaluated by myocardial imaging using thallium-201 injected intravenously during exercise when painless ST-segment depression was evident. The same examination was repeated in 5 of the above patients when they showed ST-segment depression with chest pain. Myocardial images obtained during painless ST-segment depression revealed perfusion defects in 15 of 21 patients (71%). Images obtained during ST-segment depression with chest pain showed perfusion defects in all 5 patients (100%) including 3 patients who demonstrated no defects during painless ST-segment depression. In these 5 patients, the ST-segment depression associated with pain was significantly greater than that without pain (3.4 +/- 1.1 vs 2.1 +/- 1.1 mm, p less than 0.01). These results suggest that the majority of episodes of painless ST-segment depression occurring during exercise are accompanied by regional myocardial perfusion abnormalities and that transient painless ST-segment depression in patients with angina pectoris might represent less severe myocardial ischemia.

Adult↗
PubMed1985

Palm temperature monitoring during exercise in patients with heart disease.

The quantitative use of palm temperature changes during a fixed-load treadmill exercise was evaluated in normal subjects and patients with various degrees of cardiac disability. Treadmill exercise revealed different temperature patterns between subject groups. Normal subjects showed an initial transient decrease to a plateau phase, followed by a prompt return to the control level after cessation of exercise. Cardiac patients with severe disabilities showed a progressive decrease during and even after exercise, and the return to the control level was delayed. Patients with less severe cardiac disabilities showed an intermediate pattern. A significant correlation was observed between the temperature pattern and the plasma catecholamine concentration. The simultaneous measurement of forearm and hand blood flow, and palm temperature during a supine ergometer exercise showed that the temperature change reflected the blood flow changes. In conclusion, palm temperature monitoring during treadmill exercise is a simple and useful method for assessment of the vasoconstrictor response to exercise and, therefore, the pattern of temperature changes indicates indirectly the exercise capacity in heart disease.

Blood Pressure↗
PubMed1985

Auditory short-term memory in the Japanese monkey.

Auditory short-term memory in Japanese monkeys (Macaca fuscata) was studied using a GO/NO GO auditory delayed matching to sample task. Three temporal parameters: delay interval, intertrial interval and sample stimulus duration were manipulated. Delayed matching performance deteriorated as the delay interval was lengthened, and reached a near chance level at 16 sec. Longer intertrial intervals and sample duration ameliorated performance. When the number of the sample stimulus was increased to 3 tones to examine a serial position effect, a primary effect was not observed, although a recency effect was obtained. The fragility of auditory delayed matching performance was discussed.

Animals↗
PubMed1985

Liquid scintillation counting of 55Fe applied to air-filter samples.

A simple and rapid method has been improved for determination of low specific activity of 55Fe with a liquid scintillation counter. High counting efficiency was obtained for a sample containing up to 150 mg of iron using mixture of a colorless solution of phosphate iron complex and an emulsifier liquid scintillator. The detection limit was 0.31 Bq (8.4 pCi) per gram iron assuming the counting for 1000 minutes and 95% confidence level. This counting method was applied to determination of 55Fe in air-filter samples.

Air Pollutants↗
PubMed1985

Monoclonal IgE-dependent eosinophil cytotoxicity to haptenated schistosomula of Schistosoma japonicum: enhancement of the cytotoxicity and expression of Fc receptors for IgE by Nippostrongylus brasiliensis infection.

To obtain direct evidence for the involvement of IgE antibodies in eosinophil-mediated killing of schistosomula of S. japonicum, dinitrophenylated (DNP) schistosomula pretreated with mouse monoclonal IgE antibodies were co-cultured with purified rat peritoneal eosinophils. It was found that the eosinophil-mediated adherence and damage to haptenated schistosomula were dependent on a monoclonal anti-DNP IgE antibody, but not on monoclonal anti-ovalbumin IgE antibody. Moreover, eosinophils from N. brasiliensis-infected rats demonstrated an enhanced ability in the IgE-dependent damage to DNP-schistosomula as compared with the cells from normal rats. The enhancement was associated with an increase in the proportion of eosinophils expressing Fc receptors for IgE.

Animals↗