Cannabinoids inhibit nitric oxide production in bone marrow derived feline macrophages

Feline immunodeficiency virus (FIV) infection causes a widespread natural immunodeficiency syndrome in cats that is considered a suitable animal model for studying human immunodeficiency virus (HIV) infection and pathogenesis. Short term cultures of bone marrow derived feline macrophages stimulated with recombinant feline interferon-gamma (r-IFN-gamma) and lipopolysaccharide (LPS) were shown to produce nitric oxide. Feline macrophages were shown to express cannabinoid receptors, and nitric oxide production decreased after in vitro exposure to synthetic cannabinoid CP-55940. Both cannabinoid receptors, CB1 and CB2, were involved in this process, since the inhibition was reversed by selective cannabinoid antagonists for both of these receptors.     

Signalment and clinical features of diskospondylitis in dogs: 513 cases (1980-2001)

OBJECTIVE: To determine signalment, clinical features of the disease, and treatment in dogs with diskospondylitis. DESIGN: Case-control study. ANIMALS: 513 dogs with diskospondylitis (cases) and 236,109 canine hospital accessions (controls) from 12 veterinary teaching hospitals. PROCEDURE: Information retrieved from the medical records of 123 dogs with diskospondylitis at the Louisiana State University veterinary teaching hospital between 1980 and 2001 included sex, age, breed, primary complaint, neurologic status, location of lesions, causative organism, treatment, and outcome. The signalment of 390 additional cases from 11 other veterinary teaching hospitals was accessed from the Veterinary Medical Database. Comparisons were made with controls from the same time periods. RESULTS: Male dogs were twice as likely as female dogs to be affected (odds ratio [OR], 2.0; 95% confidence interval [CI], 1.7 to 2.4). Dogs were significantly more likely to be affected as age increased. Purebred dogs, especially Great Danes, were more likely than mixed-breed dogs to be affected (OR, 73; CI, 4.3 to 12.6). For dogs from Louisiana State University, Staphylococcus spp, Brucella spp, Streptococcus spp, and Escherichia coli were isolated most often; multiple organisms were detected via microbial culture in 11 dogs. The mean duration of treatment was 53.7 weeks. CONCLUSIONS AND CLINICAL RELEVANCE: Male dogs, older dogs, and Great Danes appeared more likely to be affected with diskospondylitis than female dogs, dogs < 1 year of age, and mixed-breed dogs, respectively. Long-term administration of antimicrobial drugs for treatment of diskospondylitis may be expected. Identification of the causative organism and early treatment are recommended.     

Physiologically based demographic models streamline identification and collection of data in evidence‐based pest risk assessment

The distribution and abundance of species that cause economic loss (i.e., pests) in crops, forests or livestock depends on many biotic and abiotic factors that are thought difficult to separate and quantify on geographical and temporal scales. However, the weather‐driven biology and dynamics of such species and of relevant interacting species in their food chain or web can be captured via mechanistic physiologically based demographic models (PBDMs). These models can be implemented in the context of a geographic information system (GIS) to predict the potential geographic distribution and relative abundance of pest species given observed or climate change scenarios of weather. PBDMs may include bottom‐up effects of the host on pest dynamics and, if appropriate, the top‐down action of natural enemies. When driven by weather, PBDMs predict the phenology, age structure and abundance dynamics at one or many locations enabling the distribution of the interacting species to be predicted across wide geographic areas. PBDMs are able to capture relevant ecosystem complexity within a modest number of measurable parameters because they use the same ecological models of analogous resource acquisition and allocation processes across all trophic levels. The use of these analogies makes parameter estimation easier as the underlying functions are known. This is a significant advantage in cases where the biological data available to build an evidence base for pest risk assessment is sparse.     

Acute Toxicity by Oral Co-Exposure to Palytoxin and Okadaic Acid in Mice

The frequent occurrence of marine dinoflagellates producing palytoxin (PLTX) or okadaic acid (OA) raises concern for the possible co-presence of these toxins in seafood, leading to additive or synergistic adverse effects in consumers. Thus, the acute oral toxicity of PLTX and OA association was evaluated in mice: groups of eight female CD-1 mice were administered by gavage with combined doses of PLTX (30, 90 or 270 μg/kg) and OA (370 μg/kg), or with each individual toxin, recording signs up to 24 h (five mice) and 14 days (three mice). Lethal effects occurred only after PLTX (90 or 270 μg/kg) exposure, alone or combined with OA, also during the 14-day recovery. PLTX induced scratching, piloerection, abdominal swelling, muscle spasms, paralysis and dyspnea, which increased in frequency or duration when co-administered with OA. The latter induced only diarrhea. At 24 h, PLTX (90 or 270 μg/kg) and OA caused wall redness in the small intestine or pale fluid accumulation in its lumen, respectively. These effects co-occurred in mice co-exposed to PLTX (90 or 270 μg/kg) and OA, and were associated with slight ulcers and inflammation at forestomach. PLTX (270 μg/kg alone or 90 μg/kg associated with OA) also decreased the liver/body weight ratio, reducing hepatocyte glycogen (270 μg/kg, alone or combined with OA). No alterations were recorded in surviving mice after 14 days. Overall, the study suggests additive effects of PLTX and OA that should be considered for their risk assessment as seafood contaminants.     

Resistance to the glasshouse whitefly (Trialeurodes vaporariorum Westw.) in tomato (Lycopersicon esculentum Mill.) and related species

Summary Eighty-five accessions of Lycopersicon esculentum and related species were tested for resistance to the glasshouse whitefly, Trialeurodes vaporariorum Westw. High levels of resistance were found in L. hirsutum, L. hirsutum glabratum and Solanum pennellii. In other species, too, some resistance was observed. A breeding program is in progress.     

The Rabbit Subventricular Zone (SVZ): An Ultrastructural and Immunocytochemical Study

Veterinary Research Communications -     

Ecotoxicological Impact of the Marine Toxin Palytoxin on the Micro-Crustacean Artemia franciscana

Palytoxin (PLTX) is a highly toxic polyether identified in various marine organisms, such as Palythoa soft corals, Ostreopsis dinoflagellates, and Trichodesmium cyanobacteria. In addition to adverse effects in humans, negative impacts on different marine organisms have been often described during Ostreopsis blooms and the concomitant presence of PLTX and its analogues. Considering the increasing frequency of Ostreopsis blooms due to global warming, PLTX was investigated for its effects on Artemia franciscana, a crustacean commonly used as a model organism for ecotoxicological studies. At concentrations comparable to those detected in culture media of O. cf. ovata (1.0–10.0 nM), PLTX significantly reduced cysts hatching and induced significant mortality of the organisms, both at larval and adult stages. Adults appeared to be the most sensitive developmental stage to PLTX: significant mortality was recorded after only 12 h of exposure to PLTX concentrations > 1.0 nM, with a 50% lethal concentration (LC₅₀) of 2.3 nM (95% confidence interval = 1.2–4.7 nM). The toxic effects of PLTX toward A. franciscana adults seem to involve oxidative stress induction. Indeed, the toxin significantly increased ROS levels and altered the activity of the major antioxidant enzymes, in particular catalase and peroxidase, and marginally glutathione-S-transferase and superoxide dismutase. On the whole, these results indicate that environmentally relevant concentrations of PLTX could have a negative effect on Artemia franciscana population, suggesting its potential ecotoxicological impact at the marine level.     

Correction to: Thermal biology of Tuta absoluta: demographic parameters and facultative diapause

Journal of Pest Science - Formula, Equation&nbsp;2 and the table&nbsp;3 are published incorrectly in the original publication of the article. The correct version of the article is given below     

Technical note: An improved leaf disk technique for biotests

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Technical note: An improved leaf disk technique for biotests