Development of Monoclonal Antibody based Heterologous Immunoassay for Ractopamine Residue
ADVANCED BUILDING MATERIALS AND STRUCTURAL ENGINEERING
Authors: Li, ChaoYing; Jiang, JinQing
Abstract
This study aimed to develop a monoclonal antibody based icELISA method for Ractopamine (Rac) residue. For this purpose, mixed anhydride method was employed to synthesize the immunogen of Rac-BSA and 1, 4-butanediol diglycidyl ether was used to prepare the coating antigen of Rac-OVA, thus pursue the heterologous sensitivity. Through cell fusion technology, four Hybridoma named R1-B5, R2-B3, R2-C6, and R4-C8 were screened out, and the Kas of all mAbs were between 2.7 and 4.8x 10(9) L/mol. Based on the R1-B5 mAb, a heterologous icELISA standard curve was developed. The working range was from 0.013 to 33.7 ng/mL, with LOD and IC50 value of 0.007 ng/mL and 0.67 ng/mL, respectively. Therefore, this icELISA can be used for detecting Rac residue in animal products.
Single, escalating dose pharmacokinetics, safety and food effects of a new oral androgen dimethandrolone undecanoate in man: a prototype oral male hormonal contraceptive
ANDROLOGY
Authors: Surampudi, P.; Page, S. T.; Swerdloff, R. S.; Nya-Ngatchou, J. J.; Liu, P. Y.; Amory, J. K.; Leung, A.; Hull, L.; Blithe, D. L.; Woo, J.; Bremner, W. J.; Wang, C.
Abstract
The novel androgen, dimethandrolone (DMA) has both androgenic and progestational activities, properties that may maximize gonadotropin suppression. We assessed the pharmacokinetics of dimethandrolone undecanoate (DMAU), an orally bioavailable, longer acting ester of DMA, for male contraceptive development. Our objective was to examine the safety and pharmacokinetics of single, escalating doses of DMAU (powder in capsule formulation) administered orally with or without food in healthy men. We conducted a randomized, double-blind Phase 1 study. For each dose of DMAU (25-800mg), 10 male volunteers received DMAU and two received placebo at two academic medical centres. DMAU was administered both fasting and after a high-fat meal (200-800mg doses). Serial serum samples were collected over 24h following each dose. DMAU was well tolerated without significant effects on vital signs, safety laboratory tests or electrocardiograms. When administered while fasting, serum DMA (active compound) was detectable in only 4/10 participants after the 800mg dose. When administered with a 50% fat meal, serum DMA was detectable in all participants given 200mg DMAU and showed a dose-incremental increase up to 800mg, with peak levels 4-8h after taking the dose. Serum gonadotropins and sex hormone concentrations were significantly suppressed 12h after DMAU administration with food at doses above 200mg. This first-in-man study demonstrated that a single, oral dose of DMAU up to 800mg is safe. A high-fat meal markedly improved DMAU/DMA pharmacokinetics.