Artificial organs
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Pyridoxalated-hemoglobin-polyoxyethylene conjugate (PHP), which is made from out-dated human red blood cells by two major chemical modifications, namely pyridoxalation and conjugation with polyoxyethylene (POE), is currently under development as a physiological oxygen carrier. This study assessed the effects of PHP-88 solution, which contains 8% (wt/vol) each of hemoglobin (Hb) and maltose, on renal function when it was infused 3 times every other day into the intact circulation of 8 dogs (5 dogs for the PHP group and 3 for the control group; 20 ml/kg for the first infusion, and 10 ml/kg each for the second and third infusions, at the rate of 2.5 ml/h/kg). Serial determinations of glomerular filtration rate (GFR) and renal plasma flow (RPF) were carried out pre- and postinfusion for up to 3 months along with measurements of blood and urine analyses, urine output rate, fractional excretion of sodium (FES), and free water clearance (CH2O). ⋯ Though urinary N-acetyl-beta-glucosaminidase (NAG) activity had significantly increased after infusion, it returned to the preinfusion level by 1 month postinfusion. No detrimental effect of vacuoles on the assessed renal tubular functions was confirmed in the present study. The results demonstrated that multiple infusions of PHP solutions were well tolerated in normal dogs, and the observed effects were conceived predominantly attributable to the physiological response of the kidneys to an oncotic load into the circulation, which produced plasma volume expansion.
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Blood has become essential as a test fluid to evaluate hemolysis and biocompatibility of blood pumps in vitro. The blood is usually pumped from a blood bag into a circuit against elevated pressure. A throttle or a length of tubing is used to produce the pressure head. ⋯ The TXB2 release was 296 +/- 70 and 305 +/- 54 pg/0.1 ml respectively after 4 h. In summary, no significant differences between the two setups for either fHb or TXB2 could be detected. So the use of a throttle, which requires far less priming volume and a smaller blood-contacting surface while also offering a wider range of adjustment, seems preferable.(ABSTRACT TRUNCATED AT 250 WORDS)