Small Volume Of Saline Research Articles

THE INFLUENCE OF INTRAVASCULAR FLUID VOLUME ON THE PERMEABILITY OF NEWBORN AND ADULT MOUSE LUNGS TO ULTRASTRUCTURAL PROTEIN TRACERS

The permeability of the alveolar-capillary membrane of newborn and adult mice to horseradish peroxidase (HRP) and catalase was studied by means of ultrastructural cytochemistry, and the permeability to ferritin was studied by electron microscopy. The influence of varying volumes of intravenously injected fluid on the rate of leakage of the tracers from pulmonary capillaries was examined. The tracers were injected intravenously and the mice were sacrificed at timed intervals. Experiments on newborn mice with intranasally instilled HRP were also done. The tissues were fixed in formaldehyde-glutaraldehyde fixative. Chopped sections were incubated in Graham and Karnovsky's medium for peroxidase and in a modification of this medium for catalase. Tissues were postfixed in OsO(4) and processed for electron microscopy. In both newborn and adult mice, the ready passage of peroxidase through endothelial clefts was dependent on the injection of the tracer in large volumes of saline. When the tracer was injected in small volumes of saline, its passage through endothelial clefts was greatly reduced. Endothelial junctions of newborn mice were somewhat more permeable to HRP than those of adult mice. In all animals, alveolar epithelial junctions were impermeable to HRP. Catalase and ferritin did not pass through endothelial junctions. Intranasally instilled HRP in newborn mice was taken up by pinocytotic vesicles and tubules of flat alveolar cells.

Factors Influencing Leukoagglutination by Antileukocytic Sera

Summary A rapid procedure for leukoagglutination by specific antisera and conditions which influence it are presented. The procedure consists in suspending leukocytes in a small volume of saline, counting the cells with pipette and chamber and measuring out 27,000 cells per mm3 in 0.05 ml of normal saline. To the cells is added 0.5 ml of antiserum diluted with normal saline. The cell-antiserum mixture is centrifuged for one minute and the results are read. The entire procedure is carried out at 22 to 26 C. Agglutination of leukocytes is inhibited at 8 C and the velocity is reduced at 37 C. The optimal temperature is 22 to 26 C. Centrifuging results in the greatest speed of antigen-antibody reaction. Immature leukocytes and especially those outside the body for 2 to 3 days are destroyed more readily than mature cells by hypotonic salt solution. Agglutination requires the presence of intact cells. Electrolytes are necessary for the visible phase of agglutination and the optimal range is 0.85 to 2.5 per cent. Mature leukocytes are agglutinated in lower concentrations. Ageing of cells outside the body interferes with agglutination and mature leukocytes are agglutinated up to the fourteenth day. Immature cells show little or no clumping after the fourth day. Repeated washing of leukocytes does not interfere with agglutination until after the tenth time when most of the cells are destroyed. Hemoglobin up to 50 per cent does not interfere with agglutination. A definite number of leukocytes is necessary for a satisfactory agglutination. Excess or decrease in the number of cells modifies the degree of clumping.

Failure to Demonstrate Pressor Properties in Extracts of Blood from Hypertensives

The theory that hypertension may be due to the accumulation of a humoral pressor substance or substances of renal origin has been supported by the finding of increased concentrations of pressor material in kidneys from patients with various hypertensive diseases and from dogs with experimental renal hypertension, Against this hypothesis is the failure to find increased pressor properties in the blood of subjects with hypertension. Recent chemical studies indicated that the pressor principle in rabbits'kidneys is related to the globulins. This work suggested the possibility of concentrating the hypothetical pressor substance in blood by similar chemical procedures. The present report is concerned with the vasomotor properties of extracts of human and of dog's blood containing protein fractions prepared in the following way. Approximately 100 cc of freshly drawn blood was defibrinated and centrifuged. The serum was drawn off and half saturated with ammonium sulfate, and the resulting precipitate dialyzed against tap water until free of sulphate. The dialysate was then dried in a Florsdorf-Mudd apparatus and taken up in a small volume of saline. The final solution was tested by intravenous injection into small unanesthetized dogs with Van Leersum (carotid) loops, and the effect on the blood pressure noted. Observations were made on the blood of 5 patients with persistent hypertension, and 3 dogs with hypertension due to renal ischemia. In no instance was a well-defined pressor response noted. The failure to find the renal pressor material in the blood stream may be due to a number of possible causes, such as inefficient extraction, insufficient amount of the pressor substance in the blood stream, or differences between the chemical properties of renal pressor substance in man and rabbits. It is also possible that ultimately the pressor substance may prove to have no relation to hypertension.