Ink Particles Research Articles

Variations in the leucocyte count upon single and repeated injection of quartz and of Indian ink particles

Variations in the leucocyte count upon single and repeated injection of quartz and of Indian ink particles

THE RELATION OF THE RETICULO-ENDOTHELIAL SYSTEM TO THE FORMATION OF AMYLOID

The facts presented suggest strongly that reticulo-endothelial cells are actively concerned in the formation of amyloid. Points in favor of this theory are as follows: 1. The appearance of amyloid in places where reticulo-endothelial cells are normally present, sometimes in very large number. 2. The formation of early amyloid in the small solitary patches, which suggests its local formation. 3. The occurrence of solitary patches of amyloid apparently located within the capillaries of the liver. 4. The manifold relations between reticulo-endothelial cells marked out by phagocytized ink granules, loose ink particles and amyloid, described in the text. 5. The impossibility of demonstrating reticulo-endothelial cells in areas of forming amyloid by intravenous injections of India ink. 6. The delayed appearance of amyloid in animals after blockage of the reticulo-endothelial cells by repeated intravenous injections of India ink.

THE VASCULAR ARRANGEMENTS OF THE MAMMALIAN SPLEEN

1. The circulation through the splenic pulp is an open one, but the Malphigian follicles have closed capillaries. The rate of flow is sluggish in certain areas, notably about the follicles.2. The ellipsoids are collections of intensely phagocytic mononuclear cells, occurring at or near the termination of the penicillar arteries of the spleen of certain animals. These cells are embedded in a fine reticular framework which acts as a filter for foreign particles.3. Ellipsoids do not occur in the rabbit.4. The size of the ellipsoids depends largely upon the need for such tissue at the time.5. They are not perfect one‐way valves.6. In the spleen of the cat and dog phagocytosis of Indian ink particles is carried on largely by cells of these structures.7. After phagocytosis and migration of the phagocytes, regeneration of the ellipsoids occurs by proliferation of the cells at the termination of the penicillus.8. Marked hyperplasia of the ellipsoids may result from injection of suitable amounts of foreign particles.I wish to express my thanks to Professor JOHN TAIT for assistance during the prosecution of this investigation and in preparation of the manuscript.The expenses of the research were in part defrayed by a grant from the James Cooper Fund of McGill University for Research in Experimental Medicine.

PLATELETS AND BLOOD COAGULATION

1. Under dark‐field illumination the platelets of previously cooled mammalian plasma have been observed. During the first two or three minutes they undergo progressive expansion, while clear blebs or spherules begin to appear round their margin. Then the platelets suddenly disintegrate, and the spherules travel swiftly outwards into the surrounding plasma, diminishing in size down to eventual extinction as they progress.2. In the path followed by a spherule a filament of fibrin appears. The length and thickness of the individual filaments differ, according to the size of the platelet that gives birth to the spherule and according to the plasma under examination. We look upon the material in the spherules as thrombin.3. The dark‐field observations have been checked and verified by examination of slides fixed in the wet condition at appropriate intervals after the plasma is placed on glass.4. The only blood elements concerned in spontaneous coagulation of mammalian blood are the platelets.5. If the plasma taken from an animal which has shortly before received an intravenous injection of Indian ink is allowed to clot, the ink is seen partly within the remains of the cytolysed platelets and partly incorporated in or adhering to the fibrin.6. If blood taken from an animal that has shortly before received an intravenous injection of Indian ink is defibrinated by stirring with a stick, all the ink particles which are still free are caught in the fibrin that forms on the stick.7. If the blood is taken three hours after intravenous injection of ink, the circulating pigment is mainly in leucocytes, the platelets containing only a very small amount.8. The fact that three hours after intravenous injection of ink platelets are quite abundant while ink‐holding platelets are few is evidence that the original ink‐laden platelets have come to rest some‐where and that a new crop has been thrown into the circulation.9. The accumulation of fibrin around a stick used in whipping blood is due, in the first instance, to adhesion of the platelets to the wood, and any mass of so‐called “fibrin” obtained in this way is a mixture of fibrin proper and of cytolysed platelets.We wish to express our indebtedness to Professor J. C. Simpson of the Histology Department for advice and help in preparing the illustration that accompanies this paper. The drawing itself was made by Miss H. Blackstock.The expenses of the research were defrayed in part by a grant from the James Cooper Fund of M'Gill University for Research in Experimental Medicine.