Treatment of canine parvoviral enteritis with interferon-omega in a placebo-controlled challenge trial

Canine parvoviral enteritis continues to cause significant morbidity and mortality in dogs worldwide, and efficacious antiviral therapies are lacking. The present trial was aimed at evaluating the therapeutic efficacy of a recombinant feline interferon (type omega) preparation in the treatment of parvoviral enteritis in dogs. A double-blind, placebo-controlled challenge trial was performed in beagle pups (8-9 weeks); clinical signs, body weight, hematologic parameters, and mortality were monitored for a period of 14 days after challenge. Fourteen animals were inoculated with virulent canine parvovirus; 10 animals that developed clinical signs thereby meeting the inclusion criteria were admitted to the treatment phase in two randomly selected groups (placebo and IFN) of equal size. The IFN group received daily intravenous injections of rFeIFN-omega (2.5 MU/kg) for three consecutive days. The placebo group received daily injections of saline without IFN. Both groups of animals received individual supportive treatment consisting of adjusted diet and electrolyte solution.All five dogs in the placebo group developed fulminating enteritis with typical clinical signs and died within 10 days post-inoculation (or 6 days post-treatment). In the IFN-treated group, one animal died on day 2 after the treatment was started, whereas the other four dogs survived the challenge and gradually recovered. Our data confirm that the rFeIFN-omega can exert a significant therapeutic effect on dogs with parvoviral enteritis by improving clinical signs and reducing mortality.     

A comparative study of two antimicrobial/anti-inflammatory formulations in the treatment of canine otitis externa

The efficacy and tolerability of a marbofloxacin-clotrimazole-dexamethasone otic suspension (MCD) was compared with a standard topical treatment using a phase III clinical trial protocol. In a total of 140 dogs with clinical signs of acute or subacute otitis externa, Staphylococcus, Pseudomonas, Enterobacteriaceae and Malassezia were isolated from samples taken at inclusion to identify the causative pathogen; a further sample was collected in the event of failure or relapse, and from dogs (at day 14) for which Pseudomonas species had been isolated at inclusion. One group received MCD (10 drops per affected ear) once daily and a second received Surolan (containing polymyxin B, miconazole and prednisolone) (5 drops per affected ear), twice daily. Each group received treatment for 7 or 14 days according to the clinical outcome on day 7. Efficacy and tolerability were evaluated on days 7, 14 and, if necessary, 28 for dogs treated for 14 days. The trial demonstrated equivalence of both treatments in terms of efficacy, with a cure rate of 58.3% for MCD and 41.2% for Surolan. Both medications were equally well tolerated by dogs, but MCD was superior in terms of pain relief, decrease in pus quantity and smell, response rate and investigator's assessment on day 14.     

Modelling of sorption experiments and seepage data of an Amazonian Ultisol subsoil under cropping fallow

The results of physico-chemical investigations of an Ultisol subsoil under a 2-year old fallow in eastern Amazonia are presented. Subsoil chemistry was studied using 4 different approaches: i) concentrations of H, Na, K, Ca, Mg, Mn, Al, and Fe in seepage water were measured under field conditions, ii) the equilibrium soil chemistry was studied in sequential batch experiments where the soil was treated with different solutions, iii) results of batch experiments were simulated with a chemical equilibrium model, and iv) the seepage data were calculated using selectivity coefficients obtained by modelling the batch experiments. The model included multiple cation exchange, precipitation/dissolution of Al(OH)₃ and inorganic complexation. Cation selectivity coefficients were pK_x/Ca^sel: X = Na: 0.3, K: 0.8, Mg: ?0.1, and Al: 0.4. The amount of cations sorbed ranged from ?0.2 to 2.0 (K), ?0.7 to 2.3 (Mg), ?1.6 to 1.8 (Ca), ?4.8 to 3.6 (Al) and 0.0 to 8.5 (Na) mmol_c kg^?1. The model predictions were good with values lying within 0.3 pH units (for the pH range 3.7 to 7.2), and 3% of CEC for individual cations. The most important proton buffer reaction seemed to be the dissolution of gibbsite and a large release of Al into the soil solution. When selectivity coefficients obtained by the modelling procedure were used to predict the field data for cation concentrations in the seepage water, they decreased in the following order: Na > K > Ca > Mg > Al. These calculated values were similar to the measured order: Na > Ca > K ≈ Mg > Al. Thus the options for managing these soils should be carefully chosen to avoid soil acidification which may result from inappropriate use of fertilizer during the cropping period.     

Modeling multi-scale spatial ecological processes under the discrete event systems paradigm

A multi-scale spatial ecological model of a wet sclerophyllous forest subject to recurrent fires is presented. The model is specified in a Discrete Event Systems framework (DEVS) (Zeigler, 1990) interfaced with a Geographic Information System (GIS), and includes the ability to simulate landscape dynamics at several levels of resolution simultaneously. This is achieved by encoding a modular hierarchical representation of the forest landscape components into a set of nested, interconnected, and spatially referenced dynamic models. The results of the landscape dynamics simulations are displayed as sequences of maps through time, illustrating the potential of this modeling methodology for dealing with complex hierarchical structures that operate at several spatial and temporal resolutions.Research work supported by Junta Nacional de Investigaçäo Científica e Tecnológica, Portugal, and the Advanced Resource Technology Program, University of Arizona, USA.     

Characterization of urea–formaldehyde resin penetration into medium density fiberboard fibers

The amount of UF resin penetration into fibers, used for the production of medium density fiberboard (MDF), is unknown. To evaluate the relationship between resin viscosity and resin penetration depth, an experimental procedure involving confocal laser scanning microscopy (CLSM) and a Toluidine Blue O staining system was performed. The results indicate that CLSM in combination with a Toluidine Blue O staining system is a good way to characterize UF resin penetration into wood fibers. The main penetration direction is toward the fiber lumen. For wet fibers, whose moisture content is about 88%, the effect of resin viscosity with a range of 80 cps – 340 cps on penetration is very similar, with all adhesives reaching or almost reaching the fiber lumen after 60 min at room temperature. For MDF industrial samples, the highest depth of penetration of the adhesive was attained in the second dryer stage. After the second dryer stage, the resin penetration into the fiber did not increase.