Diluted Blood Plasma Research Articles

Coagulation Tests and Selected Biochemical Analytes in Dairy Cows with Hepatic Lipidosis

The aim of this study was to determine the values and changes in conventional and optimised clotting tests, as well as in selected biochemical analytes during hepatic lipidosis in postpartum dairy cows. Ten healthy and ten Holstein cows with hepatic lipidosis were selected based upon clinical history, clinical examination, liver biopsy, flotation test and histological analysis of hepatic tissue. Prothrombin time (PT) and partial thromboplastin time (PTT) were determined in non-diluted and diluted blood plasma samples. Clotting times determined in diluted plasma samples were prolonged in cows with hepatic lipidosis and there was a difference in the PT value at both 50% and 25% plasma dilutions between both groups of animals (P = 0.004 and P = 0.001). Significant differences between healthy animals and cows with hepatic lipidosis were observed in blood serum values for free fatty acids (FFA), aspartate aminotransferase (AST) and triacyglycerols (P = 0.001, P = 0.007 and P = 0.044), respectively. FFA and liver biopsy are better diagnostic indicators for hepatic lipidosis than coagulation tests. The optimised PT is prolonged in cows with hepatic lipidosis and can detect this alteration that cannot be appreciated using conventional PT test.

Kinetics of protein deposition and replacement from a shear flow

AbstractKinetics of plasma protein deposition and replacement from a shear flow of full strength and diluted blood plasma onto prewetted glass were studied both numerically and experimentally. A band of fibrinogen moving down the adsorbing surface was predicted and observed. The band was shown to define the region where blood platelets subsequently adhered to the surface. Since platelet adhesion is a fundamental component of thrombosis, this observation is potentially pertinent to the long‐sought mechanism that determines where thrombus forms during shear flow of blood through artificial devices. The discrepancies between the mathematical model and experimental observations are explained by the presence of the natural convection, arising from density differences between plasma and the wetting fluids.

Reproductive period affects water intake in heat-stressed dehydrated goats

Water intake following dehydration was studied in pregnant (N = 5), lactating (N = 4) and nonpregnant, nonlactating (N = 5) Swedish domestic goats ( Capra hircus) to investigate if reproductive period affected drinking. Plasma cortisol concentration and the hematocrit value were measured to evaluate stress. The goats were water deprived from 9.00 h until 15.05 h the next day. They were fed at 7.00 and 15.20 h. On the second day, ambient temperature was increased from 20°C to 38–39.5°C for 5.15 h to accelerate water losses. Water temperature during erhydration was 35 ± 1°C. Plasma Na concentration and osmolality increased most in dehydrated and heat-stressed pregnant and lactating goats. Pregnant goats lost 2.2 kg of their body weight. They drank 3.5 l immediately, followed by 2.5 l during afternoon eating. Lactating goats lost 4.9 kg and drank 6.3 l at once, and 3.9 l during feeding. Nonpregnant, nonlactating goats lost 1.7 kg and drank 2.6 l followed by 0.6 l. The large water consumption in pregnant and lactating goats caused hyponatremia and hemodilution, but they continued to drink during the night (0.5 ± 0.2 l and 0.8 ± 0.5 l, respectively). Renal free water clearance increased in all periods, with a long-lasting water diuresis during pregnancy. Plasma cortisol concentrations and the hematocrit values rose in connection with water intake. These results imply that the thirst center became less sensitive to inhibitory signals from the oropharyngeal tract and the diluted blood plasma during pregnancy and lactation. Catching sight of water was the most exciting procedure during these experiments.

A Mathematical Model for the Vroman Effect

Adsorption and desorption at a surface are frequently the physical-chemical basis for boundary conditions used in analyzing bulk transport. The common Langmuir-like specifications of adsorption and desorption fail to match observations if desorption does not occur, involves more than one adsorbed state for one or more molecular types, or depends strongly upon the presence of particular dissolved species. In this paper the Langmuirian formulation is generalized to account for such phenomena. The result is fitted to data of Brash that quantify the Vroman effect, manifested as sequential adsorption of proteins from diluted blood plasma. The fitted parameters are then used to quantify ringlike patterns of protein adsorption that have been observed when dilute plasma is injected into the narrow space between a glass slide and a spherical lens resting on it. Previous elaborations of the Langmuirian boundary condition either fail to account for important qualitative features of complicated adsorption, or treat it with highly particular and not widely accepted parameters.

Voltammetric determination of cyadox using adsorptive accumulation in a flow-through system

Cyadox, one of the quinoxaline- N-dioxide derivatives used as a grwoth promoter, has been determined voltammetrically after adsorptive accumulation on the surface of a hanging mercury drop electrode in a flow-injection system. A simple detector slipped onto the capillary of a static mercury drop electrode immersed in an electrolyte solution together with the reference and auxiliary electrodes were used for the detection. With a 1000 μl injected sample volume, a linear calibration plot was obtained at a Cyadox concentration level of 10 −8 mol 1 −1: slope of the calibration line 0.154 nA n M −1, intercept −0.453 nA, standard error 0.091 nA, correlation coefficient 0.999. Diluted blood plasma samples (from pigs) were analyzed using the flow-injection approach and adsorptive accumulation without the necessity of a separation procedure.

Determination of copper concentration in blood plasma and in ocular and cerebrospinal fluids using graphite furnace atomic absorption spectroscopy

Published values for the concentration of Cu in cerebrospinal and intraocular fluids cover a very wide range (0.016 to 1.0 μg/ml) and include values which are several times higher than those which would be consistent with normal physiology. An atomic absorption spectrophotometer equipped with a graphite furnace was used to measure the Cu concentration in these fluids and in blood plasma of toads, rabbits, and cats. Under standard conditions, these fluids yielded high background absorbance and only fractional recovery of added Cu. Parameters were therefore established which eliminated both the high background and the matrix interference and allowed the determination of Cu in 10-μl aliquots of diluted blood plasma and undiluted cerebrospinal and ocular fluid samples. Under these conditions the Cumeasured in the ocular (0.011 to 0.032 μg/ml) and cerebrospinal fluids (0.033 to 0.050 μg/ml) of these three species was lower than most previously reported values and only a small fraction (1–3%) of the concentration of Cu in the plasma of the same animals (0.85 to 1.22 μg/ml).

Microbial blood-coagulating protease screening test and some properties.

A potent fungus for blood-coagulating enzyme was isolated from soil during screening tests of about 1500 strains of microorganisms. The fungus was identified as a strain belonging to Cephalosporium. This enzyme could be produced effectively by solid culture on wheat bran and partially purified to about 800 fold. This enzyme was one of the alkaline proteases. It was stable over a pH range of 7~10 and was activated by Ca2+ The enzyme could not coagulate 1% fibrinogen solution. The enzyme mixed with diluted blood plasma coagulated the fibrinogen solution. The enzyme also coagulated the citrated plasma from humans, bovines, mice, goats and hens.

The fat content, morphology and length of life of cells growing in diluted blood plasma

Cells growing in unmodified blood plasma (Harrison's method) exhibit regularly an accumulation of fat droplets in their cytoplasm. In the case of the cells of the chick embryo this fat accumulation is quite marked after 24 to 48 hours, and reaches a maximum after five to seven days, at which time the cells are distended with fat droplets. The experiments herewith reported were planned to determine the effect of a reduction in the fat content of the culture medium, brought about by dilution of the plasma, on the accumulation of fat by the cells. In the course of the experiments the influence of dilution on the length of life and morphology of the cells was also observed. One part of plasma added to twenty or twenty-five parts of Ringer's solution forms a medium which coagulates satisfactorily in hanging drops. Studies were made with dilutions of 1:2, 1:5, 1:10, 1:15, and 1:20 of pigeon plasma in Ringer's solution, containing 0.9 per cent. NaCl. Pieces of chick embryo heart were used for cultivation. The tissue was finely divided into pieces of suitable size for cultures, which were washed in Ringer's solution for a half hour before using. Cultures from the various series were fixed in formalin at the end of two, three and four days and stained with hematoxylin and Sudan III. In plasma diluted 1 : 2 the cells live practically as long (5 to 10 days without transfer), as in pure plasma, and show a similar accumulation of fat. In a 1 : 5 dilution the fat content is slightly diminished; there is little or no effect on the length of life or on the morphology of the cells.