ABSTRACT
OBJECTIVES: Bovine and human blood has been widely used for in vitro hemolysis testing to evaluate centrifugal cardiac assist pumps. However, results from such tests are complicated by variations in the susceptibility of individual red blood cells to shear. The objective of this study was to evaluate the use of microcapsule suspension as an alternative to bovine or human blood for hemolysis testing. METHODS: Microcapsule suspensions of 100 micro m maximal diameter (average 79.1 micro m) with a polyurethane membrane were used. Each microcapsule contained a leuco dye, which was used to measure "hemolysis" in the suspension after exposure to mechanical stress. Six centrifugal pumps were used to measure and compare the hemolysis values of microcapsule suspensions, bovine blood and human blood. RESULTS: Correlations were significant between the hemolysis values measured using microcapsule suspensions and those using bovine blood (R = 0.965, p = 0.002) and human blood (R = 0.940, p = 0.005). CONCLUSIONS: Microcapsule suspension can be successfully used instead of blood to compare the relative hemolytic performance of centrifugal blood pumps.
Subject(s)
Capsules , Heart-Assist Devices , Hemolysis , Materials Testing/methods , Suspensions , Animals , Cattle , Centrifugation , Coloring Agents , Humans , Pilot ProjectsABSTRACT
Water consumption by sheep in 48-h periods was measured in three replicated experiments. Intake was expressed as ml X kg body weight-.73 X d-1 and treatments were compared with intake of tap water or distilled water in no-choice situations. Neutralizing two acid mine drainage (AMD) polluted waters having pH values of 2.4 and 2.8, with Ca(OH)2 did not make either as acceptable to sheep as unpolluted water (P less than .01). Simulating AMD with sources of H+, HSO4-, SO4 =, Fe , Al++, Mn++, Zn++ or Na+ revealed several significant differences in acceptance. The ferric ion at 2.6 mM was rejected when presented as Fe2(SO4)3 but not as equimolar FeCl3. Moreover, SO4 = at 3.9 mM was not rejected when presented as Na2SO4 or ZnSO4. Neither AlSO4 nor MnSO4 at levels found in the two sources of AMD was rejected. Effects of prolonged consumption of the various components have not been determined.
Subject(s)
Alum Compounds , Drinking Behavior , Manganese Compounds , Minerals/analysis , Mining , Sheep/physiology , Water Pollution, Chemical , Water/analysis , Aluminum/analysis , Animals , Female , Ferric Compounds/analysis , Hydrogen-Ion Concentration , Manganese/analysis , Sulfates/analysis , Sulfuric Acids/analysisABSTRACT
Some variations in animal health among geographic areas are associated with variations in soils, water supplies or soil parent materials. Geochemical bases for health problems arising from essential nutrient element deficiencies or from toxic levels or imbalances of several elements are widely recognized. Less attention has been directed to the possibilities of geochemical influences upon regional differences in health resulting from pathogens, parasites, mycotoxins and poisonous plants. This review is an effort to collect and interpret such evidence as has been published on the subject since Louis Pasteur's original observation associating soil character and probability of anthrax.
Subject(s)
Animal Diseases/etiology , Soil , Water Supply , Zoonoses , Animals , Bacterial Infections/etiology , Bacterial Infections/veterinary , Helminthiasis/etiology , Helminthiasis, Animal , Minerals/toxicity , Mycoses/etiology , Mycoses/veterinary , Mycotoxins/biosynthesis , Plant Poisoning/etiology , Plant Poisoning/veterinary , Virus Diseases/etiology , Virus Diseases/veterinaryABSTRACT
Kidneys from 32 autopsied Caucasian human subjects aged 16-60 were frozen then lyophilized while the flasks were kept in insulating containers. (Subjects with evidence of extensive weight loss, chronic renal failure, or carcinoma were not included). Replicate samples of cortex were removed, weighed, and wet-ashed in HNO3-HClO4. Zn, Cd, and Cu were estimated by atomic absorption spectrophotometry with the 2261 Å line used for Cd background correction. Se was estimated by fluorescence with DAN in a Turner fluorimeter, but a #74 Kodak Wratten filter was added to minimize the 500 nm interference noted by E. Pickett (personal communication, 1980).Means and variability for the three elements in kidney cortex were similar to those in a North Carolina study as was Cd/(Cd+Zn)×100. Cortical Cd (P<0.05), Zn (P<0.10), and Cd/(Se·Zn) (P<0.05) increased with age, whereas Se showed no significant relationship with age. Age(2), nonlinear effects of age, had a slight influence upon Cu (P<0.05) only if data were not adjusted for gender. There was no influence of ageper se upon Cu with or without adjustment for gender. The scatter diagrams of element concentrations plotted vs age contained several provocative "outlier" values.A positive association of kidney cortex Cd concentration, or Cd/(Se ·Zn), with postmortem indices of hypertension existed only if age, gender, and age(2) were omitted from the multiple regression equation. This adjustment was not included in a similar study of North Carolina cases and appears to be the source of the major difference in their respective inferences drawn about the positive relationship of kidney cortex Cd with evidence of hypertension. This difference in statistical models does not however account for the failure of the West Virginia sample to indicate a protective role of kidney cortex Se suggested for the North Carolina subjects. Larger samples, drawn from regions differing in Se abundance, will be necessary to test the latter question adequately.
