The six MAbs neutralized vaccine strains and virulent strains of poliovirus. Five MAbs were serotype specific, while one MAb cross-neutralized serotypes 1 and 2. Epitope mapping performed by selecting and sequencing antibody-resistant viral variants indicated that the cross-neutralizing MAb
bound between antigenic sites 1 and 2, thereby covering the canyon region containing the receptor-binding site. Another serotype 1-specific MAb recognized a region located between antigenic sites 2 and 3 that included parts of capsid proteins VP1 and VP3. Both serotype 2-specific antibodies recognized antigenic site 1. No escape mutants to serotype 3-specific MAbs could be generated. The administration of a serotype 1-specific MAb to transgenic mice susceptible
to poliovirus at a dose of 5 www.selleckchem.com/products/Verteporfin(Visudyne).html mu g/mouse completely protected them this website from paralysis after challenge with a lethal dose of wild-type poliovirus. Moreover, MAb injection 6 or 12 h after virus infection provided significant protection. The MAbs described here could be tested in clinical trials to determine whether they might be useful for treatment of immunocompromised chronic virus excretors and for emergency protection of contacts of a paralytic poliomyelitis case.”
“Introduction: It is important to identify all circulating metabolites, including free fluoride, for accurate pharmacokinetic modeling of [F-18]-labeled radiotracers. We sought to determine
the most efficient method to detect and quantify low levels of free [F-18]fluoride in biological samples.
Methods: Low levels of [F-18]fluoride were analyzed using two methods: (A) an ion-exchange cartridge and gamma counting, and (B) radio-HPLC, to compare the detection limits of these two analytical methods. Twenty microliters of [F-18]fluoride solution was loaded onto an ion-exchange cartridge, then eluted with 20% MeCN/water (5 ml) and radioactivity trapped in the cartridge counted on a gamma counter. [F-18] Fluoride was also determined in plasma and urine from mice injected with [F-18]-labeled thymidine analogues using Method A.
Results: The detection sensitivity of Method A was 9.4-fold Lactose synthase higher than that of Method B (0.075 +/- 0.004 vs. 0.71 +/- 0.02 nCi). With Method A, [F-18]fluoride was determined in plasma for [F-18]FLT, [F-18]FMAU, [F-18]FEAU and N-3-[F-18]FPrT as 1.4 +/- 0.31% (n=4), 0.17 +/- 0.49% (n=3), 4.88 +/- 1.62% (n=3) and 12.94 +/- 0.48% (n=4), respectively. The amount of [F-18]fluoride determined in the urine was 11.49 +/- 1.60% (n=4) from [F-18]FLT, 5.36 +/- 2.34% (n=3) from [F-18]FMAU, 13.57 +/- 1.96% (n=3) from [F-18]FEAU and 11.19 +/- 1.98% (n=4) from N-3-[F-18]FPrT.
Conclusion: Low levels of [F-18]fluoride in biological samples can be detected and quantified using an ion-exchange cartridge and gamma counting.