The comparative metabolism of diisopropyl methylphosphonate in mink and rats

This study reports the metabolism of carbon-14labeled diisopropyl methylphosphonate (DIMP) in mink and rats, undertaken to better understand the dose-related mortality reported for mink in a previous study. In both male and female mink and rats, DIMP was rapidly absorbed after oral administration; it was metabolized by a saturable pathway to a single metabolite, isopropyl methylphosphonate (IMPA), which was rapidly excreted, primarily in the urine (90%). Fecal radioactivity, also identified as IMPA, was 1.7-3.1% of the administered dose. Female rats had a slower rate of conversion of DIMP to IMPA and less total excretion of IMPA than male rats. Metabolism of DIMP administered intravenously was not very different from that given orally in both species. These data indicate that mink absorb, metabolize, and excrete DIMP (as IMPA) in a manner very similar to mice, rats, and dogs.     

Complex gain and fixed-point digital predistorters for CDMA power amplifiers

Two digital baseband predistortion techniques, one based on the complex gain digital predistorter (CGDP) approach and the other based on the fixed-point predistorter (FPPD) approach, are used to compensate a nonlinear high-power amplifier (HPA) in an IS-2000 system. Forward-link performance for a perfectly linear HPA, nonlinear HPA, and compensated HPA using both a CGDP and an FPPD are compared using an IS-2000 forward-link simulator. Both predistortion techniques are shown to provide similar forward-link performance and reduction in spectral regrowth of the sidebands for the wide-band compensated HPAs utilized by IS-2000 systems.     

Hematologic response of adult brown mink to oxidative stress

We evaluated the response of mink to oral administration of the oxidant compound propylene glycol (PG) to better understand the relative susceptibility of mink red blood cells (RBC) to oxidant injury. Feeding a diet containing 12% PG to 6 mink for 1 w resulted in a 17% decrease in hematocrit, a 21% decrease in RBC count and a 4.8-fold increase in reticulocyte count. A marked increase in Heinz body and eccentrocyte numbers was consistent with oxidative injury to RBC. Because of high food intake, mink ingested approximately twice the quantity of PG/kg body weight compared to domestic cats fed diets containing 12% PG. Therefore, the severity of the hematologic dyscrasia in mink may be the result of greater intake of PG rather than unique sensitivity of mink RBC of oxidative injury. However, the high food intake and the mink's position at the top of the food chain may increase its exposure to environmental contaminants.