An isolated epizootic of hemorrhagic-like fever in cats caused by a novel and highly virulent strain of feline calicivirus

An isolated epizootic of a highly fatal feline calicivirus (FCV) infection, manifested in its severest form by a systemic hemorrhagic-like fever, occurred over a 1-month period among six cats owned by two different employees and a client of a private veterinary practice. The infection may have started with an unowned shelter kitten that was hospitalized during this same period for a severe atypical upper respiratory infection. The causative agent was isolated from blood and nasal swabs from two cats; the electron microscopic appearance was typical for FCV and capsid gene sequencing showed it to be genetically similar to other less pathogenic field strains. An identical disease syndrome was recreated in laboratory cats through oral inoculation with tissue culture grown virus. During the course of transmission studies in experimental cats, the agent was inadvertently spread by caretakers to an adjoining room containing a group of four normal adult cats. One of the four older cats was found dead and a second was moribund within 48-72h in spite of symptomatic treatment; lesions in these animals were similar to those of the field cats but with the added feature of severe pancreatitis. The mortality in field cats, deliberately infected laboratory cats, and inadvertently infected laboratory cats ranged from 33-50%. This new isolate of calicivirus, named FCV-Ari, was neutralized at negligible to low titer by antiserum against the universal FCV-F9 vaccine strain. Cats orally immunized with FCV-F9, and then challenge-exposed shortly thereafter with FCV-Ari, developed a milder self-limiting form of disease, indicating partial protection. However, all of the field cats, including the three that died, had been previously immunized with parenteral FCV-F9 vaccine. FCV-Ari caused a disease that was reminiscent of Rabbit Hemorrhagic Disease, a highly fatal calicivirus infection of older rabbits.     

Effective gas flow arrangements in soil venting

Soil venting is a remediation technology specifically designed to extract contaminant vapors from vadose-zone soils through application of vacuum at one or more recovery wells installed below the surface. In the present work, screening models are developed which can contribute to the design and optimization of soil venting processes by providing means for comparative evaluation of different extraction strategies. The development of a steady-state gas flow model and a vapor-phase mass transport model permits vacuum extraction performance and venting gas flow patterns to be evaluated for desired combinations of well placement, operating pressure(s), surface capping, air injection, and soil characteristics. Additionally, the performance of the gas-flow model was assessed by comparison with laboratory and field data.     

Transfer of interferon-producing macrophages: new approach to viral chemotherapy

Mice were protected from infection with Semliki Forest virus and encephalomyocarditis virus by the transfer of peritoneal macrophages that were stimulated to produce interferon in vitro by exposure to a nonreplicating virus. This method of therapy was also utilized in animals infected with encephalomy-ocarditis virus after onset of clinical signs. Of these animals 40 percent recovered, but only 9 percent of the control group recovered.     

Fetal response to viral infection: interferon production in sheep

When virus was inoculated intravenously during the third trimester, the gestating ewe produced only low amounts of serum interferon, whereas the fetal lamb had the capacity to produce extremely high amounts. There was no evidence of transplacental transfer of interferon between mother and fetus in either direction.     

Activity of mesotrione on resistant weeds in maize

Mesotrione is a new callistemone herbicide that inhibits the HPPD enzyme (p-hydroxyphenylpyruvate dioxygenase) and introduces a new naturally selective tool into weed-management programmes for use in maize. Mesotrione provides control of the major broad-leaved weeds, and it can be used in integrated weed-management programmes depending on the grower's preferred weed-control strategy. At post-emergence rates of 150 g AI ha-1 or less, mesotrione provides naturally selective control of key species that may show triazine resistance (TR), e.g. Chenopodium album L, Amaranthus species, Solanum nigrum L, as well as species of weed that show resistance to acetolactase synthase (ALS) inhibitors e.g. Xanthium strumarium L, Amaranthus spp and Sonchus spp. The data presented show that resistant and susceptible biotypes of these species with resistance to triazine herbicides, such as atrazine, simazine, terbutylazine and metribuzin, or ALS-inhibitor herbicides, such as imazethepyr, remain susceptible to mesotrione. These results confirm that there is no cross-resistance in biotypes with target site resistance to triazine or ALS-inhibiting herbicides. It is important that herbicide choice and rotation becomes an integral part of planning weed management, so as to minimise the risks of crop losses from weed competition, build-up of weed seed in the soil and the further development of weed resistance across a range of herbicide modes of action.