A therapeutic regimen for purging dieldrin from adulterated individuals
SummaryIn four feedlots 1013 steers had become contaminated by being fed over 50% of their diet as cull seed potatoes containing 0.1 to 0.2 ppm dieldrin (dry weight basis), developing residues of up to 0.76 ppm (rendered fat). These residues were in excess of federal guidelines (0.30 ppm, rendered fat), but considered non-pathological and without physiological effect. Application of a therapeutic regimen, consisting of an initial injection of testosterone propionate and vitamins A, D and E and of daily oral doses of phenobarbital (first 20 days only) and activated charcoal in a finishing ration, resulted in marked reductions in dieldrin residues within 30 days. The rate of dieldrin loss was increased six-fold and the residual half-life reduced from a reported 150 to 250 days to about 25 to 80 days. The effectiveness of individual components or combinations was not evaluated, but the rate of charcoal feeding appeared most important.
Organochlorine Insecticide Problemsin Livestock
Although the use of persistent organochlorine pesticides has been severely restricted in recent years, problems with both acute poisoning and, especially, residues still occur in food animals. Therapy for acute intoxication consists of supportive care and blocking further absorption of the toxicant. Therapeutic regimens devised to date for contaminated livestock are not universally successful but may be useful in certain circumstances.
Temperature effects on lily development rate and morphology from the visible bud stage until anthesis.
Day (DT) and night temperatures (NT) influenced Lilium longiflorum Thunb. 'Nellie White' stem elongation and development rate from the visible bud stage (VB) until anthesis. Plant height increase after VB was a function of the difference (DIF) between DT and NT (DT-NT). Plant height increased 90% as DIF increased from - 16 to 16C. A cubic model described bud development rate as a function of temperature from 14 to 30C. A linear model adequately described bud development rate as a function of average daily temperature from 14 to 21C. Based on the linear model, bud development rate increased 0.05 per day for each 1C increase in average daily temperature. The base temperature for bud development, i.e., the temperature at which bud development rate was 0, was calculated as 3.5C. Greenhouse forcing of vernalized Easter lilies is commonly divided into three phases: I) placement of vernalized bulbs in the greenhouse to flower initiation, II) flower initiation to VB, and III) VB to anthesis (De Hertogh and Wilkins, 1971). Plant morphological development differs during each of the forcing phases (De Hertogh and Wilkins, 1971). Growth during phase I is vegetative and consists of stem elongation and leaf expan- sion. Flower initiation, leaf expansion, and stem elongation oc- cur during phase II. Inflorescence expansion and stem elongation occur during phase III. Lily responses to temperature during phase III differed from those during phases I and II (Wang and Roberts, 1983). Lily development rate, quantified as days to unfold a leaf, is a de- creasing linear function of average daily temperature between 14 and 30C during phases I and II (Karlsson et al., 1988). Lily development rate during phase III is a nonlinear function of temperature (Healy and Wilkins, 1984). The effect of temper- ature on the rate of lily development decreases as DT and/or NT increase during phase III (Rob and Wilkins, 1973; Healy and Wilkins, 1984). Easter lily morphological development is thermomorpho- genie. For instance, internode length increases as the DIF be- tween DT and NT increases (Erwin et al., 1989). In addition, leaf orientation, leaf length, and flower length are also influ- enced by diurnal changes in temperature.