Comparison of different substances for subureteric injection in the management of vesicoureteric reflux in children.

INTRODUCTION: Endoscopic techniques are becoming increasingly accepted for treatment of vesicoureteric reflux as alternatives to open surgical reimplantation. However, there is some debate about the ideal injectable material. Since we have accumulated experience with several substances, an opportunity existed to compare them. MATERIALS AND METHODS: From 1991 to 2003, 101 children with vesicoureteric reflux were treated by endoscopic subureteric injection either once (74) or twice (27) by either of two pediatric urologists. There were a total of 165 ureteral injections, 83 with polytetrafluoroethylene (Teflon), 73 with polydimethylsiloxane (Macroplastique), and 9 with collagen. Each child was evaluated pre-operatively and 3 months post-operatively with a nuclear cystogram and renal ultrasonography. RESULTS: The polytetrafluoroethylene and polydimethylsiloxane groups were not significantly different with respect to sex, age, indication for surgery, severity of reflux or prior surgeries. The collagen group overall did very poorly with only 3 of 9 refluxing ureters cured. The other two substances had much more success with 61% of ureters in the polytetrafluoroethylene group cured on first injection and 75% with polydimethylsiloxane, plus another 19% and 11% cured on second attempt, respectively (total 80% and 86%). CONCLUSIONS: Subureteric injections of polytetrafluoroethylene and polydimethylsiloxane are very effective at curing vesicoureteric reflux in children with little morbidity. When comparing individual cases, ureters, and all grades of reflux, polytetrafluoroethylene and polydimethylsiloxane have similar success rates. Collagen injections were less successful, and patients with neurogenic bladders had poor results.

A structural comparison of the total polar lipids from the human archaea Methanobrevibacter smithii and Methanosphaera stadtmanae and its relevance to the adjuvant activities of their liposomes.

Mice were immunized with bovine serum albumin (BSA) entrapped within archaeosomes (i.e. liposomes) composed of the total polar lipids (TPL) from the two methanogenic archaea common to the human digestive tract. Methanobrevibacter smithii archaeosomes boosted serum anti-BSA antibody to titers comparable to those achieved with Freund's adjuvant, whereas Methanosphaera stadtmanae archaeosomes were relatively poor adjuvants. An explanation for this difference was sought by analysis of the polar lipid composition of each archaeobacterium. Fast atom bombardment mass spectrometry and NMR analyses of the purified lipids revealed a remarkable similarity in the ether lipid structures present in each TPL extract. However, the relative amounts of each lipid species varied dramatically. The phospholipid fraction in M. stadtmanae TPL was dominated by archaetidylinositol (50 mol% of TPL) and the glycolipid fraction by beta-Glcp-(1,6)-beta-Glcp-(1,1)-archaeol (36 mol%), whereas in M. smithii extracts, both caldarchaeol and archaeol lipids containing a phosphoserine head group were relatively abundant. Liposomes prepared from purified archaetidylinositol and from M. stadtmanae TPL supplemented with increasing amounts of phosphatidylserine elicited poor humoral responses to encapsulated BSA. A dramatic loss in the adjuvanticity of M. smithii archaeosomes was seen upon incorporation of 36 mol% of the uncharged lipid diglucosyl archaeol and, to a lesser extent, of 50 mol% of archaetidylinositol. Interestingly, the relative rates of uptake of M. smithii and M. stadtmanae archaeosomes by phagocytic cultures in vitro were similar. Thus, the lipid composition may influence archaeosome adjuvanticity, particularly a high diglucosyl archaeol and/or archaetidyl inositol content, resulting in a low adjuvant activity.