Dietary Administration of Asimina triloba. (Paw Paw) Extract Increases Tumor Latency in N.-Methyl-N.-nitrosourea–Treated Rats

Abstract

The paw paw tree, Asimina triloba. (L.) Dunal (Annonaceae), contains more than 50 bioactive components, primarily annonaceous acetogenins. Some therapeutic activities have been associated with this material, but the potential to mediate a cancer chemopreventive effect has not been reported. In this study, a standardized extract from the twigs, in which bullatacin, asimicin, and trilobacin represent the most potent and major bioactive acetogenins, was tested in the N.-methyl-N.-nitrosourea–induced mammary carcinogenesis model. With Sprague-Dawley rats given a diet containing paw paw extract (1250 and 2500 mg/kg diet; based on maximum tolerated dose studies), mammary tumor latency was increased from 55 to 66 days. However, mammary tumor incidence and multiplicity were not affected by extract consumption.     

Performance of sulfur dioxide passive monitors

The following four commercial sulfur dioxide passive monitors were tested for performance and realiability: DuPont Pro-Tek C-20 air monitoring badges; MSA Vaporgard Dosimeter tubes; REAL BioBadges; and 3M Sulfur Dioxide Nutshell monitors. The experiments conducted were designed to test factors critical to the operation of passive samplers: accuracy and precision; capacity; stability; analytical recovery; and the effects of exposure time, concentration, humidity, face velocity, orientation, chemical interference, and temperature. The DuPont Pro-Tek badges performed satisfactorily for all the factors tested, and the REAL BioBadges performed satisfactorily except for the instability of the SO2/tetrachloromercurate complex when stored. An alternate monitoring system, REAL BioBadges containing deionized water absorbent had a limited capacity. Only the MSA dosimeters exhibited unsatisfactory performance. The 3M Nutshell monitor was withdrawn by the manufacturer after only partial evaluation.     

Prophylaxis of recurrent urinary infections in children. Long-term use of a weak dose of trimethoprim-sulfamethoxazole

The efficacy of a long-term prophylaxis with Co-trimoxazole was studied in 18 girls with recurrent urinary tract infections. SEven patients had neither anatomical nor functional anomalies of the urinary tract. Eight patients had a vesico-ureteral reflux, and three patients a complex urinary problem. The following therapeutic plan was applied: administration of a low dose of Co-trimoxazole (TMP: 0,6-1 mg/kg) given as a single evening dose during 3 months followed by a 3-month period without treatment. The children were followed in this way during 2 years. Seven children had no reinfection from the start of the prophylaxis during the 2 years of observation. Nine children had a significant decrease of the number of reinfections during the Co-trimoxazole treatment periods. Two children without anatomical anomaly had early reinfections with Co-trimoxazole resistant germs. No side effects related to Co-trimoxazole have been observed, and the tolerance of treatment was excellent. Co-trimoxazole administered as a single evening low dose efficiently prevented the recurrence of urinary tract infections.