Julian L. Ambrus

In Vivo Fibrinolytic Activity and Pharmacology of Various Plasmin (Fibrinolysin) Preparations

A quantitative method based on the disappearance of I131 labeled fibrin has been used to study the in vivo effect of fibrinolytic agents. Various preparations of human and bovine plasmin were found to lyse clots effectively. The minimal effective dose of human plasmin prepared by the method of Kline was 15 Loomis units/Kg. Plasmin preparations given intravenously produced hypotension and leukopenia followed by leukocytosis. Doses above 30 Loomis units/Kg. caused decrease in fibrinogen level and clotting index.

Quantitative Method for the In Vivo Testing of Fibrinolytic Agents: Effect of Intravenous Trypsin on Radioactive Thrombi and Emboli

Quantitative methods for testing fibrinolytic agents in vivo are described. Methods based on the incorporation into the clot of P32 labeled blood cells or Cr51 labeled erythrocytes were found to be unsatisfactory. Clots were produced with I131 labeled fibrinogen. Dissolution of a clot resulted in decrease of radioactivity. This was recorded by placing segments of blood vessels in a special lead shield containing a scintillation detector head, connected to a radiation rate meter and an Esterline recorder. Pulmonary, peripheral and coronary emboli were produced by injecting radioactive clots produced and ground, in vitro. Using these methods it was found that maximal tolerated doses of trypsin showed no significant fibrinolytic effect.

Toxicity of Histamine and Antagonism between Histamine and Antihistamines in Various Strains of Mice

Summary 1. Sensitivity to histamine of four strains of mice has been compared. 2. Within one strain older and heavier mice appeared to be more resistant than younger and lighter ones. 3. The more histamine sensitive a strain or weight-range of mice proved to be, the more protection was observed by pretreatment with an antihistamine. 4. It is suggested that the toxicity of histamine in mice may be manifested through two different mechanisms.

Histamine releasers and histamine sensitivity.

Histamine Releasers and Histamine Sensitivity Sm,-Harvey (1961) reported a decreased sensitivity to histamine 6 hr. after 48/80 administration. This present report is to confirm and extend her results using different animals and methods. Normal female guinea-pigs and those desensitized to histamine by daily injection of progressively higher doses of histamine until the original LD 95 (4.0 mg./kg. subcutaneously) was tolerated were subjected to histamine aerosol before and after the administration of n-octylamine (0.3 mg./kg. subcutaneously) and 48/80 (4.0 mg./kg. subcutaneously). The Aerosol Reaction Time (A.R.T.) was determined by averaging the durations of exposure to histamine aerosol before (a) cough, and (6) dyspnoea, according

Effect of Adenosine-5-Phosphoric Acid, Adenosine-3-Phosphoric Acid and Adenosine Triphosphate on the Growth of Ehrlich Carcinoma

Effect of Adenosine-5-Phosphoric Acid, Adenosine-3-Phosphoric Acid and Adenosine Triphosphate on the Growth of Ehrlich Carcinoma

Effect of the reticulo-endothelial blockade by thorotrast on the development of normal heterohemagglutinins in fowl

Der Kaninchen-Heterohämagglutinin-Titer im Serum von weißen Leghorn-Kücken wurde einen Tag, nachdem die Kücken ausgebrütet waren, bestimmt. Danach wurde der Titer wöchentlich, während neun Wochen, ermittelt. Wöchentliche intrakardiale Verabreichung von 6 cm3/kg Thorotrast hatte keinen Einfluß auf die Entwicklung von normalen Kaninchen-Heterohämag-glutininen. Die gleiche Dosis von Thorotrast erwies sich bei Verabreichung an jedem dritten Tag als toxisch. Die maximal erreichbare retikulo-endotheliale Blockade durch Thorotrast scheint die Entwicklung normaler Heterohämagglutinine nicht zu beeinflussen.