Vesicoureteral reflux and complete ureteral duplication. Conservative or surgical management?

PURPOSE: The management of vesicoureteral reflux (VUR) in a duplicated collecting system (DS) is controversial. Available literature is sparse and it does not assess all co-factors. We compared the outcome of VUR in DS cases with VUR in single system (SS) cases, given similar clinical management in the 2 groups. MATERIALS AND METHODS: A retrospective cohort study was done to compare the outcome of VUR in 35 children (44 units) with a DS and in 95 (150 units) with an SS. Patients with secondary reflux, incomplete duplication and ureterocele were excluded. Two groups were similar in terms of prognostic factors. Mean followup in the DS and SS groups was 43 and 48 months, respectively. Outcomes of interest were spontaneous resolution or uncomplicated persistence vs surgical correction. The same criteria were used to intervene surgically in the 2 groups. RESULTS: In the DS group 24 of 35 patients (69%) underwent surgery compared with 25 of 95 (25%) in the SS group. Multivariate analysis showed an association between surgery due to complications and the presence of DS (p = 0.0001). Higher grade and female gender were independent predictors (p = 0.02 and 0.0007, respectively). The likelihood of undergoing surgery was the same for low grade VUR (I and II) in the DS and SS groups (p = 0.16). No resolution was seen in the duplex group with severe VUR at a mean followup of 42 months. CONCLUSIONS: Low grade VUR in DS cases has an outcome similar to that of VUR in SS cases. Females with moderate or high grade VUR and a DS should be treated differently because they present more often with complications.

Structure-biodegradability relationships in pyrethroid insecticides.

The metabolism of 20 pyrethroids has been examined to evaluate the contribution of detoxification in their selective action between insects and mammals. The studies utilized living houseflies, mice, or rats, or esterase and oxidase systems derived from these organisms. Pyrethroid-hydrolyzing esterases cleave the primary alcohol trans-substituted-cyclopropanecarboxylates much faster than the corresponding cis-isomers but are ineffective in hydrolyzing secondary alcohol esters. Microsomal enzymes oxidize the (+)-trans-chrysanthemate moiety at the trans-methyl group of the isobutenyl substituent and at one of the gem-dimethyl groups whereas the (+)-cis-isomer is attacked at either of the isobutenyl methyl groups. Products isomerized at C3 of the cyclopropane are also detected but only after ester cleavage and oxidation of an isobutenyl methyl group. Each alcohol moiety has its own unique sites for oxidation involving pentadienyl, allyl, benzylic methylene, and aromatic substituents. An enhancement of insecticidal activity is expected on replacement of the biodegradable groupings with substituents relatively resistant to metabolism but this may also increase the mammalian toxicity.