Five-Month Oral (Diet) Toxicity/lnfectivity Study of Bacillus thuringiensis Insecticides in Sheep

Five-Month Oral (Diet) Toxicity/Infectivity Study of Bacillusthuringiensis Insecticides in Sheep. HADLEY, W. M., BURCHIEL,S. W., MCDOWELL, T. D., THILSTED, J. P., HIBBS, C. M., WHORTON,J. A., DAY, P. W., FRIEDMAN, M. B., and STOLL, R. E. (1987).Fundam. Appl. Toxicol. 8, 236–242. Bacillus thuringiensisinsecticides (Bt) [Dipel (test substance D or Thuri-cide-HP(test substance T)] were administered in the diet for 5 monthsto castrated mixed ram-bouillet/merino sheep (24–34 kgat the beginning of the study) at a dose of 500 mg/kg/day (approximately10¹² spores per day). No treatment-related effect was seen onweight gain or clinical chemistry parameters nor were significantgross clinical changes observed. Several blood and tissue samplestaken just prior to the time the animals were killed or at necropsywere found to be positive for Bt when cultured. Detailed grossand microscopic pathologic examination of the sheep revealedseveral incidental lesions. However, the only lesion that mayhave been associated with the treatment was lymphocytic hyperplasiain Peyer's patches seen in the cecum of three sheep and it wasnot considered to be clinically significant.     

Late Potential Parameter and Noise Level Variability Caused by Bandpass Versus High-Pass Filtering and Type of Signal Averaging Equipment Used

Late potentials detected by signal averaged electrocardiography are predictive of ventricular arrhythmia induction and sudden cardiac death. Prior studies have used a variety of equipment and filtering parameters. The correlation between data from two commercially available signal averaging units and the effects of bandpass as opposed to high-pass filtering were studied in 18 hospitalized patients. The addition of a low-pass filter at 250 Hz to high-pass filtering at 40 Hz caused no significant change in any time domain variable (total duration of the filtered QRS, root mean square voltage of the last 40 msec of the filtered QRS, and duration of low-amplitude potentials < 40 μV). However, the data was significantly different (P < 0.01) when studies from the two machines were compared. We conclude that bandpass filtering does not affect time domain late potential variables in a clinically relevant fashion compared to high-pass filtering alone. Significant data differences exist between the two different pieces of equipment. Therefore, caution should be exercised in extrapolating data obtained from each of the different machines.     

Pacemaker Electrode Repositioning Using the Loop-Snare Technique

Using a percutaneous femoral vein approach under fluoroscopic control, a malpositioned ventricular pacemaker electrode was released from the right ventricular wall by hooking the lead with a deflecting wire inserted into a RIM catheter. A closed loop was formed by tightening the handle of the wire allowing the electrode to be dislodged and pulled into the inferior vena cava. The electrode was then snared using a loop formed by an exchange wire advanced through an 8 French catheter with a J-curve steamed at its tip. The electrode was advanced to the right ventricular apex and released by advancing one end of the snare wire while pulling the other end to open the loop.