Plasmanate: a new plasma substitute for pediatric therapy

Plasmanate(R), a human-serum protein solution, appears to have all the attributes of an ideal plasma expander. Freedom from infection, immediate availability in a clear, stable solution and the apparent absence of antigenic properties are particularly valuable qualities. The efficacy and safety of Plasmanate was clinically demonstrated in the treatment of 125 infants and children. This solution seems especially effective in the treatment of acute shock states and for the physiologic correction of hypoproteinemia. Comparison with other plasma expanders makes Plasmanate the agent of choice in the initial treatment of shock states in pediatrics.     

Indicators of the blood coagulation system in dogs after compensation of blood loss with protesalin--a new plasma substitute solution

It is shown that coagulability depression developed after acute hemorrhage (50 ml/kg) is not intensified by transfusion of the equal volume of protesalin, a new plasma-substituting solution. Normalization of the studied indices is observed a week after the blood loss and transfusion of the plasma-substituting solution.     

Metabolism of an isolated brain perfused with perfluoro blood substitute

An unanesthetized, isolated, perfused rat brain, consisting of the skull and its contents with nearly all other tissues removed, has metabolic and electrical activity similar to that of the brain of the intact rat with its blood-brain barrier intact. Its use yielded results that are difficult or impossible to obtain fromin vitro preparations orin vivo. With the perfused brain it was shown that, mannose can completely replace glucose as metabolic substrate, that insulin has no direct effect on the brain, in the absence of added substrate glutamate is metabolized to aspartate, the brain does not metabolize ethanol, and morphine probably inhibits mitochondrial oxidative activity. Since the use of a perfluoro blood substitute to perfuse the brain avoids the optical interference caused by haemoglobin, it was possible to measure changes in the oxidation-reduction state of NADH by surface fluorometry of the cerebral cortex.     

Selenium, glutathione and glutathione peroxidases in blood of patients with chronic liver diseases

Disturbances in the antioxidant system could play a role in pathogenesis of chronic liver disease. The aim of our study was to evaluate the levels/activities of antioxidants in blood of patients with chronic liver disease. We estimated selenium and glutathione concentrations and glutathione peroxidase activities in blood of 59 patients with chronic hepatitis B or C virus infection (group 1) and 64 patients with alcoholic, autoimmune or cryptogenic chronic liver disease (group 2). The results were compared with 50 healthy controls. Whole blood and plasma selenium and red cell glutathione concentrations were significantly lower in the patients compared with the controls. Red cell glutathione peroxidase activity was slightly reduced in both subgroups of group 1 and in group 2 with normal alanine aminotransferase values. Plasma glutathione peroxidase activity was slightly but significantly higher in patients with elevated aminotransferase values. The findings suggest that disturbances in antioxidant parameters in blood of patients with chronic liver disease may be the cause of the peroxidative damage of cells.     

Kinetic aspects of enzyme activity changes in blood plasma during canine hemorrhagic shock

The kinetics of the increase in activities of eight enzymes in plasma was investigated in hemorrhagic shock in dogs (8.0 kPa, 120 min). The time-course of enzyme activity changes in shock differed between animals and depended on their sensitivity to shock. In the shock-sensitive group of dogs an exponential activity increase was already observed in the hypotension period. However, the dogs of the less shock-sensitive group showed a delay of enzyme release with significantly less pronounced elevation of all enzyme activities except creatine kinase. The initial exponential rise of enzyme activities, which approximately followed first-order kinetics, was quantitatively characterized by the release rates. There was a close correlation between the molecular weights of enzymes and their release rates during shock in both groups of dogs. The relevance of the results to mechanisms of enzyme transport from the cell into the blood is discussed.     

Culturing Culex quinquefasciatus mosquitoes with a blood substitute diet for the females

Abstract. The tropical house mosquito Culex quinquefasciatus was cultured by feeding the females on an artificial diet, not on live animals or whole blood. This anautogenous strain has been maintained for more than fifty generations. The blood replacement diet for female mosquitoes, designed to simulate the tonicity and density of host blood, was based on ovalbumin, soya infant formula, globulins and adenosine triphosphate.
Female adults of Cx quinquefasciatus were fed the artificial blood formula from 'Parafilm' wax membrane-covered beakers. The diet was heated by radiant heat from a chamber containing an exothermic chemical reaction. This maintained the diet at a temperature of 33–37C for a period of up to 6 h, sufficient time to enable all the female mosquitoes to imbibe to satiation. After six generations on the artificial diet, female fecundity stabilized to a satisfactory level: the number of eggs per gonotrophic cycle averaged c. 85% of the 'control' strain fed on whole blood from live anaesthetized guinea-pigs, i.e. 156 eggs per female from nine feeds on the artificial diet compared with 183 from six feeds of whole blood. Adult weight of Cx quinquefasciatus females was not significantly different, from generation 6 onwards, for strains fed on artificial diet or whole blood. Sex ratio and the rate of egg viability were also equivalent for the two strains.     

Effect of supplementation with selenium on whole blood glutathione peroxidase activities and on plasma and tissue selenium concentrations in lambs

In recent years the selenium (Se) intake of the human population of the UK has shown a marked decline from 60 μg/d in 1978 to around 30 μg/d in 1990 owing largely to a significant reduction in the importation of North American wheat for bread-making fluor. Other countries (Finland, for example) in similar situations have instituted fertilization programs in order to raise cereal Se concentrations and thus boost dietary intakes. An alternative approach would be to increase the Se concentration of carcass meat by supplementation of meat animals for a limited period prior to slaughter. A trial was set up with store lambs to evaluate this approach. Sixteen Scottish Blackface lambs were stratified according to live weight and then randomly allocated to one of four treatments: unsupplemented, or 3.5, 7, or 10.5 mg. Se/head/wk. After 14 wk, the lambs were sacrificed and samples of shoulder and thigh muscle, liver, and kidney were obtained for analysis. All three treatments effected an increase in whole blood glutathione peroxidase (GSH-Px) and plasma Se concentrations over controls. Shoulder, thigh, and liver Se exhibited a dose-response relationship to treatment, but kidney Se concentrations were unaffected by treatment. Muscle and some organ meat Se concentrations can therefore be increased by supplementation and could contribute to increased human dietary intakes of the element.     

Red blood cell and plasma glutathione peroxidase activities and selenium concentration in patients with chronic kidney disease: a review

The metabolism of oxygen in aerobic organisms leads to generation of reactive oxygen species (ROS). These entities are able to oxidize almost all classes of macromolecules, including proteins, lipids and nucleic acids. The physiological level of ROS is usually regulated by antioxidant defense mechanisms. There are at least three groups of antioxidant enzymes: superoxide dismutases, catalases and glutathione peroxidases (GSH-Pxs) which neutralize ROS. The trace elements (copper, zinc and selenium) bound to the active sites of the above listed enzymes play an important role in the antioxidant defense system. In mammals, a major function of selenium (Se) and Se-dependent GSH-Pxs is to protect cells from oxidative stress. Selenium concentrations and GSH-Px activities are altered in blood components of chronic kidney disease (CKD) patients. The Se level is frequently lower than in healthy subjects and the concentration very often decreases gradually with advancing stage of the disease. Studies on red cell GSH-Px activity in CKD patients reported its values significantly lower, significantly higher and lower or higher, but not significantly as compared with healthy subjects. On the other hand, all authors who studied plasma GSH-Px activity have shown significantly lower values than in healthy subjects. The degree of the reduction decreases gradually with the progression of the disease. High inverse correlations were seen between plasma GSH-Px activity and creatinine level. A gradual decrease in plasma GSH-Px activity in CKD patients is due to the fact that this enzyme is synthesized predominantly in the kidney and thus the impairment of this organ is the cause of the enzyme's lower activity. Se supplementation to CKD patients has a slightly positive effect in the incipient stage of the disease, but usually no effect was observed in end-stage CKD. Presently, kidney transplantation is the only treatment that may restore plasma Se level and GSH-Px activity in patients suffering from end-stage CKD. A few studies have shown that in kidney recipients, plasma Se concentration and GSH-Px activity are restored to normal values within a period of 2 weeks to 3 months following surgery and thus it can be acknowledged that Se supplementation to those patients has a positive effect on plasma GSH-Px activity.