Method for detection of 2-azahypoxanthine in human and rat urine

A new, simple, reproducible, and quantitative method for the detection of 2-azahypoxanthine (2-AH) in urine is described. The method is based on removal of interfering substances from urine by cation- and anion-exchange chromatography. Quantitative determination of 2-AH eluted from the anion-exchange resin involves its conversion to 5-diazoimidazole-4-carboxylic acid and subsequent coupling of this compound with N-(1-naphthyl)ethylenediamine. The resultant dye product has an absorption maximum at 505 nm in 2.4 N HCl, which is linearly related to the original 2-AH concentration in the range of 0–8 μg/ml. The only substance found to interfere and not be removed or destroyed is p-acetamidophenyl glucuronide, an excretion product of phenacetin- and acetaminophen-containing drugs.     

National seroprevalence of Toxoplasma gondii in pigs

Serum samples from 11,842 commercial pigs killed in 1983-1984 throughout the United States were tested for anti-Toxoplasma gondii antibodies by the agglutination test in dilutions of 1:25, 1:50, and 1:500. Anti-T. gondii antibodies were found in 23.9% of pigs. At dilutions of 1:25, 1:50, and 1:500, 13.5%, 6.9%, and 3.5% were serologically positive, respectively. The prevalence of anti-T. gondii antibodies was higher in breeder pigs (42%) than in market pigs (23%). These results indicate that anti-T. gondii antibodies are widespread in the national swine herd.     

Oral infection with the Salmonella enterica serovar Gallinarum 9R attenuated live vaccine as a model to characterise immunity to fowl typhoid in the chicken

Background  

Salmonella enterica serovar Gallinarum (S. Gallinarum) is the causative agent of fowl typhoid, a severe systemic disease of chickens that results in high mortality amongst infected flocks. Due to its virulence, the immune response to S. Gallinarum is poorly characterised. In this study we have utilised infection by the live attenuated S. Gallinarum 9R vaccine strain in inbred chickens to characterise humoral, cellular and cytokine responses to systemic salmonellosis.     

One man’s quest for plant constituents of therapeutic value

Distinguished Economic Botanist’s address delivered 13 June 1989 at the 30th Annual Meeting of the Society for Economic Botany, University of Tennessee, Knoxville.