Polynucleotide hydrolysis by pancreatic ribonuclease immobilized on carboxymethylcellulose]

Analysis of snail-conditioned water (SCW) from Helisoma trivolvis revealed 17 free amino acids. Those in great concentration were glycine, serine, and alanine. The concentration of sialic acid was found to be twice that of the most abundant amino acid. The behavior of miracidia of Megalodiscus temperatus, measured by the contact with return method, to agar cylinders containing single amino acids and sialic acid indicated greater responses to polar molecules charged either positively or negatively at neutral pH. The molecules elicting the greatest response were aspartic, glutamic, and sialic acid. No correlation was found between concentration of amino acids in H. trivolvis SCW and response of M. temperatus miracidia.     

Epizootic hemorrhagic disease virus and bluetongue virus serotype distribution in white-tailed deer in Georgia

Assessment of the current incidence of different adenovirus types in local gastroenteritis involved the examination of over 1,000 stool specimens annually from 1988-1992. Adenoviruses were detected by electron microscopy and/or cell culture in 32% of the specimens in which a viral pathogen was detected. The identification of every adenovirus isolate to type by neutralization with specific antisera against the first 6 types and by restriction analysis of nonneutralized isolates was started in 1990. Samples from 1988 and 1989 were examined retrospectively. Adenovirus strains were compared to those isolated in a study between 1980-1983. Enumeration of individual adenovirus types revealed a number of trends, demonstrating that rapid changes in the local incidence of several strains were occurring in Manitoba. The incidence of adenovirus type 40 (Ad40) as a cause of gastroenteritis was found to have fallen dramatically in recent years. The predominant cause of gastroenteritis in Manitoba is a variant strain of Ad41, increasing in predominance each year and now responsible for over a third of the symptomatic cases examined since 1990. The majority of restriction site differences of the Ad41 variant strain from the prototype strain Tak were mapped to the hexon and fiber genes, both of which code for the neutralizable external viral epitopes. The probability of the observed pattern of mutations occurring by chance was calculated as P < 0.0005, indicating a strong pressure for selection of these immunologically significant alterations to the viral proteins responsible for cell attachment.(ABSTRACT TRUNCATED AT 250 WORDS)