Establishment of the first International Standard for human anti-typhoid capsular Vi polysaccharide IgG.

Vi capsular polysaccharide (Vi) conjugate vaccines, which can prevent typhoid in infants and young children, are being developed. Comparative immunogenicity studies are facilitated by an International Standard (IS) for human anti-Vi IgG. 16/138, a pool of sera from volunteers which received either Vi conjugate vaccine or plain Vi vaccine, was assessed as an IS alongside U.S. reference reagent Vi-IgGR1, 2011. Samples were tested in a commercial ELISA (n = 7), a standardised ELISA based on biotinylated Vi (n = 7) and in-house ELISAs (n = 7). Valid estimates were obtained for the potency of all samples in the commercial ELISA, and the commutability of 16/138 and Vi-IgGR1, 2011 was evident for the commercial ELISA and in-house ELISAs based on a coating of Vi and protein. The WHO Expert Committee on Biological Standardization established 16/138 as the first IS for anti-Vi IgG with 100 IU per ampoule and assigned 163 IU per vial of Vi-IgGR1, 2011.

Effects of ketamine and thiopentone anesthesia on serum lipid parameters in adult bonnet monkeys (Macaca radiata).

We investigated the effect of anesthesia on serum lipid parameters in adult bonnet macaques (Macaca radiata). We treated 10 animals with ketamine hydrochloride (15 mg/kg intramuscularly) and, on the next day, thiopentone sodium (25 mg/kg intravenously). Blood samples were obtained before and after anesthetic treatment. Serum cholesterol, triglycerides, very low-density lipoprotein (VLDL), and high-density lipoprotein (HDL) were measured by autoanalyzer. Ketamine anesthesia significantly decreased serum cholesterol and HDL levels, whereas thiopentone significantly reduced triglycerides and VLDL and increased HDL values. Although the effects of ketamine hydrochloride and thiopentone sodium on serum biochemical values have been reported, no literature addressing the effect of anesthesia on lipid parameters in bonnet macaques is available. These findings will be useful in designing experiments assessing pathologic and toxicologic changes in serum lipid parameters and interpreting data obtained from adult bonnet monkeys.