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Biomedical subjects

H Mihara

Publications and source records attributed to H Mihara.

At least 163 records · Page 9Linked to original sources
PubMed1982

Fibrinolysis-coagulation system in patients with cancer of the head and neck. Preliminary report.

Five parameters of blood coagulation and fibrinolysis, viz., levels of fibrinogen, fibrinolytic activity of euglobulin, fibrinogen and/or fibrin-degradation products (FDP), antiplasmin activity, and antithrombin activity, were measured in patients with cancer of the head and neck, and the results were compared with those of healthy adults. The fibrinogen content in cancer was significantly increased (p less than 0.001), the fibrinolytic activity of euglobulin significantly enhanced (p less than 0.001), the antiplasmin activity significantly reduced (p less than 0.05), the antithrombin activity significantly reduced (p less than 0.001), and the FDP level slightly increased, although the difference was not significant. The importance of the coagulation and fibrinolytic system in cancer of the head and neck is discussed.

Adult↗
PubMed1982

Immunochemical studies of high and low molecular forms of urokinase.

The immunochemical properties of high and low molecular forms of urokinase (HMW-UK, MW 53,000, 124,000 IU/mg protein; LMW-UK, MW 32,000, 230,000 IU/mg protein) were studied with specific antisera against the functionally active heavy chain (H chain, MW 31,000, 201,000 IU/mg protein) and the light chain (L chain, MW 18,000) of HMW-UK. Using a double immunodiffusion technique, LMW-UK did not demonstrate L chain antigenicity in the molecule. Anti-L-chain serum exerted no effect on LMW-UK and the H chain, but anti-H-chain serum strongly inhibited the fibrinolytic activity of all the active enzymes (HMW-UK, LMW-UK, and H chain). Anti-L chain serum was found to exert an antifibrinolytic effect on HMW-UK.

Animals↗
PubMed1982

Effect of urokinase on fibrinolysis and fibrinogenolysis.

The thrombolytic (fibrinolytic) effect of the urinary plasminogen activator, urokinase (UK), was compared with its fibrinogenolytic effect, using an artificial circulating system, and in in vivo pulmonary embolus and femoral vein thrombosis models. The thrombus lysing efficiency (fibrinolysis/fibrinogenolysis) was, in all cases, below 1.00, indicating that fibrinogenolysis is a primary function of UK while fibrinolysis is a secondary one.

Animals↗
PubMed1981

Differences in physicochemical properties between tissue plasminogen activators from human paranasal mucous membrane and pig heart.

In order to clarify the physicochemical property of tissue plasminogen activator (TA), tissue extracts of human paranasal mucous membrane and pig heart were studied by the biochemical techniques. The studies by gel filtration revealed that two plasminogen activators of different molecular weight were present in the extract of human paranasal mucous membrane. The existence of tissue plasminogen activator with a low molecular weight (LMW-TA) has not previously been reported. This molecular weight of this compound was lower than that of cytochrome c. On the other hand, the molecular weight of tissue plasminogen activator from pig heart (PH-TA) was similar to that of ovalbumin, about 46,000 daltons, as estimated by Sephadex G-150 gel filtration. From the physicochemical property of LMW-TA, it is suggested that the LMW-TA from paranasal mucous membrane with chronic sinusitis was produced by proteases, i.e. trypsin-like enzyme, present in the mucous membrane with chronic inflammation.

Animals↗
PubMed1981

Antiplasmin activity in carrageenin-induced inflammation of rats.

The significance of inhibitors in the coagulation-fibrinolysis system was examined by inducing experimental inflammation with carrageenin. Fast-acting plasmin inhibitor, alpha 2-plasmin inhibitor (alpha 2-Pl), was recently discovered in human blood and it was stated that such alpha 2-Pl represents the most sensitive and specific inhibitor of plasmin. The possible role of alpha 2-Pl has been studied in detail in vitro and in vivo in relation to the thrombolytic condition and bleeding based on hyperfibrinolysis. However, the significance of alpha 2-Pl has not been clarified for the inflammatory state and diseases. In the present study in order to clarify the possible role of alpha 2-Pl in inflammatory responses, the antiplasmin activity in the plasma and local fluid (exudate) was investigated using an animal model of inflammation. After subcutaneous injection of carrageenin into the dorsum of rats, on day 7 and 21, the antiplasmin activity in the plasma was significantly higher than that in the plasma of non-treated rats (p less than 0.001). However, the antiplasmin activity in the plasma on day 7 was not significantly different from that on day 21. On the other hand, the antiplasmin activity in the exudate on day 21 was significantly lower than that on day 7 (p less than 0.001). Based on ;these results, it is suggested that the antiplasmin in the inflammatory exudate was consumed during the inflammation to form the hard wall of the carrageenin pouch.

Animals↗
PubMed1980

Fibrinolytic enzyme in tracheobronchial secretion of rats: existence of plasminogen activator.

It is known that a plasminogen activator exists in the secretion of various organs, i.e., the existence of plasminogen activator in milk, tears, saliva, seminal fluids, urine and bile has been already demonstrated. However, the existence of the fibrinolytic enzyme in tracheobronchial secretions has not been known until this time. We found a new method to collect the tracheobronchial secretion of rats, and succeeded in detecting the fibrinolytic activity in the tracheobronchial secretions. Furthermore, it was found that the substance exhibiting the fibrinolytic activity in this secretion was not protease but plasminogen activator. In addition, some chemical properties of this plasminogen activator are presented, and the physiological and pathophysiological significances of it are discussed in this paper.

Animals↗
PubMed1980

Effect of low molecular weight dextran sulphate on plasmin activity measured with S-2251.

The effect of low molecular weight dextran sulphate (DS) (molecular weight 3,900) on plasminogen activation by urokinase was investigated. When human plasma containing urokinase (100 IU/ml) was diluted with DS solution and acidified to pH 4, marked splitting activity of the substrate D-Val-Leu-Lys-pNA, which is a specific substrate for plasmin, appeared. Further, the precipitate obtained after centrifugation of diluted and acidified plasma exhibited remarkable substrate splitting activity. These results indicate that activation of plasminogen to plasmin by urokinase was enhanced by the low molecular weight dextran sulphate.

Centrifugation↗
PubMed1979

Effect of diuresis on urokinase excretion rate.

UK excretion rate in the diuretic state was investigated in human and animal studies. Loading of water, beer or diuretics in man decreased the UK excretion rate as urine flow increased. A linear relation between UK excretion rate and urine specific gravity was observed. Simultaneous loading of water and exercise suppressed the decrease in UK excretion rate and the increase in urine flow. In animal studies, a null value for UK excretion rate was observed as a result of giving physiological saline and/or furosemide, and a remarkable increase in urine flow was induced. These results clearly suggest the existence of a relation between renal function and UK excretion rate.

Animals↗
PubMed1979

A protease-antiprotease system in antrochoanal polyp. I. Evidence for the existence of proactivator.

Tissue extract of antrochoanal polyps showed a faint lysis area on standard fibrin plates, but streptokinase (SK)-added tissue extract showed a large lysis area. No fibrinolytic activity was observed on plasminogen-free fibrin plates. It is concluded, therefore, that the fibrinolytic activity observed after SK addition is indicative of the existence of SK-responsive protein proactivator. The tissue extract did not contain plasminogen or antiprotease against trypsin or papain. It was stable at neutral pH at 37 degrees C and stable at acid pH at 70 degrees C. The role of proactivator is discussed in relation to the growth or enlargement of antrochoanal polyps.

Adolescent↗