Minimal change glomerulopathy in a cat

A 6-year-old domestic shorthair male castrated cat was evaluated for sudden onset of vomiting and anorexia. A diagnosis of hypereosinophilic syndrome (HES) was made, and the cat was treated with imatinib mesylate. The cat had an initial clinical improvement with the normalization of the peripheral eosinophil count. After approximately 8 weeks of treatment, lethargy and anorexia recurred despite the normal eosinophil count and a significant proteinuric nephropathy was identified. Treatment with imatinib was discontinued. Ultrasound guided renal biopsies exhibited histologic, ultrastructural, and immunostaining changes indicative of a minimal change glomerulopathy (MCG) which has not previously been reported in the literature in a cat. The proteinuria and HES initially improved while the cat was treated with more traditional medications; however, both the problems persisted for 30 months that the cat was followed subsequently. Previous studies demonstrating the safety and efficacy of imatinib in cats do not report any glomerular injury or significant adverse drug reactions, and the exact cause of this cat's proteinuric nephropathy is uncertain. Nonetheless, the possibility of an adverse drug reaction causing proteinuria should be considered when initiating treatment with imatinib in a cat.     

Solubility,partitioning, and activity of copper‐contaminated soils in a semiarid region

We studied the fate of Cu in contaminated semiarid soils from two areas with different mining activities in central Chile. Several regression models were evaluated to use soil physicochemical characteristics to predict solubility, partitioning, and activity of Cu. Furthermore, we hypothesize that the type of Cu mining compound (smelter dust versus tailing sand) can be another important variable determining the bioavailability of Cu. In the studied neutral to alkaline soils, soil organic matter (SOM) enhanced Cu solubility most probably through the formation of organic complexes with dissolved organic C (DOC). As a consequence, Cu solubility and partitioning were better explained by DOC concentration than by SOM content. On the other hand, Cu activity was mainly related to soil pH and was not affected by DOC. Although we found differences between the two study areas, Cu solubility and partitioning might not be as dependent upon the origin of the Cu mining compound as upon other physiochemical characteristics that influence the concentration and characteristics of DOC. Total Cu, pH, and DOC would be the most important variables to consider on Cu solubility, however, data about the nature of SOM may certainly improve the prediction models. Thus, multiple binding site models between Cu and DOC should be studied to improve predictions of Cu solubility.     

Molecular epidemiology of foot-and-mouth disease virus type A in South America

A databank of 78 VP(1) complete sequences of type A foot-and-mouth disease virus (FMDV) from South American isolates was constructed. Forty-nine samples corresponded to FMDV that circulated between the years 1999-2008, mainly in Venezuela, where most type A outbreaks have occurred lately and twenty-nine to strains historically relevant for the continent. The phylogenetic analysis showed that all South American FMDV belonged to the Euro-SA topotype. Sixteen subgenotypes could be identified, based on a 15% nucleotide divergence cut-off criterion: eight are extinguished, three were active until the year 2002 and the remaining five circulated in Venezuela during the years 2001-2007, illustrating the potential for FMDV diversification under appropriate selective pressure. The last emergencies reported in already-free areas of Colombia in 2004 and 2008 were closely related to isolates acting in Venzuela. Evidence of positive selection over codon 170, within the immunogenic site 4 of VP1 protein, was recorded. A codon deletion in amino acid position 142, within the G-H loop, was found in some isolates within subgenotypes 14, 15 and 16. Conversely amino acid deletion 197 was restricted to all isolates within a particular genetic cluster. The present work is the first comprehensive phylogenetic analysis of FMDV type A in South America, filling a gap of knowledge with respect to both, historical and acting viruses. The results provided evidence that supports the ecosystem dynamics in the region, and also served as an input to establish genetic links of emergencies in already-declared free areas, highlighting the need for strengthening control activities.     

Neural actions of imidacloprid and their involvement in resistance in the Colorado potato beetle, Leptinotarsa decemlineata (Say)

BACKGROUND: The development of resistance to imidacloprid in eastern US populations of the Colorado potato beetle (CPB), Leptinotarsa decemlineata (Say), threatens this critical use for neonicotinoid insecticides. Previous pharmacokinetic studies with resistant adult CPBs provided no explanation for the high resistance level (over 200-fold) to topically applied imidacloprid. The authors assessed the neural activity of imidacloprid by recording spontaneous activity from a motor nerve leaving the isolated central nervous system to compare the sensitivity of the latter to imidacloprid between susceptible and resistant CPBs. RESULTS: On the isolated central nervous system, imidacloprid was initially neuroexcitatory, and neuroinhibitory at higher concentrations. The neuroexcitatory action of imidacloprid was blocked by coapplication of a specific nAChR antagonist, methyllycaconitine, indicating that it is a result of action on nAChRs. The sensitivity to the neuroexcitatory and inhibitory activities of imidacloprid varied independently among individuals in each population. The sensitivity of the central nervous system of resistant CPBs to excitation by imidacloprid did not differ from that of susceptible insects, but the sensitivity to inhibition by imidacloprid was reduced 52- to 58-fold, indicating a possible change in the sensitivity of at least one subgroup of nAChRs. CONCLUSION: This study provides evidence that reduced nerve sensitivity to the blocking action of imidacloprid is associated with imidacloprid resistance in the CPB.     

Avocado root distribution in fine and coarse-textured soils under drip and microsprinkler irrigation

A common irrigation-scheduling problem in orchards is the proper location of instruments for monitoring soil water content within the active root zone. Given the high spatial variability of soils in the field, and seasonal changes in root distribution and frequency, both within the orchard and around the trees, the accuracy and representativeness of soil water measurements can be strongly affected. Adequate soil water monitoring in orchards thus requires assessment of the variability and location of the active roots in a given location over an extended period of time. We examined the root systems of 12-year-old ‘Hass’ avocado (Persea americana Mill.) trees grafted on ‘Mexicola’ seedling rootstocks, growing in fine or coarse-textured soils, under either drip or microsprinkler irrigation systems in Central Chile. We dug 3 m long and 0.75 m deep trenches within the tree rows in spring, summer and autumn, and counted the active roots (white, diameter ≤2 mm) found on the walls. Over the three growing seasons of our study, season had the most significant effect on root distribution, as autumn root frequencies accounted for about half of the cumulative average. Also, the location of the highest concentration of roots under microsprinklers in autumn clearly differed between the fine soils, at about 200 cm from the trunk and 50–60 cm deep, and coarse soils, where they were found within 30 cm from the trunk, and within the first 25 cm of soil. Trees in fine soil had 25% more roots than those in coarse soil, and drip irrigation produced about 30% more roots than microsprinkler, although both of these figures are mainly due to the high number of roots found in the fine soil-drip irrigation combination. Overall, we found the highest root frequency within the first meter from the tree trunk, for all combinations, with some differences between irrigation types. Throughout the growing season in semi-arid regions, some changes in both the quantity of tree roots and the location of the zones of the greatest root activity should be expected, which will vary according to the seasonal soil temperatures, soil texture, and type of irrigation used.     

Ozone and Nitrogen Dioxide Levels Monitored in an Urban Area (Ciudad Real) in central-southern Spain

This work describes the evolution of NO₂ and O₃ levels from January to December of 2007, covering the four seasonal periods in the urban air of Ciudad Real in the central-southern Spain. The measurements were carried out by means of passive samplers (Radiello® samplers). Eleven samples were collected weekly, placed at different monitoring site locations. The data indicate that the mean levels obtained during this period for O₃ and NO₂ were 38.5?±?3.5 and 20.8?±?3.8 μg/m³, respectively. These measurements were compared with other studies in Ciudad Real. Meteorological conditions (temperature, pressure, humidity relative, wind speed and direction) were also investigated.     

Plant and carabid beetle species diversity in relation to forest type and structural heterogeneity

The aim of this study was to evaluate the influence of forest structure (mainly resulting from human uses) and forest type (the identity of the dominant tree species) on biodiversity. We determined the diversity of two taxonomical groups: the understory vegetation and the edaphic carabid beetle fauna. We selected eight types of forest ecosystems (five replicates or stands per forest type): pine (Pinus sylvestris) plantations of three age classes (10, 40 and 80 years since reforestation), an old-growth relict natural pine forest, and four types of oak (Quercus pyrenaica) stands: mature forests with livestock grazing and firewood extraction, mature forests where uses have been abandoned, “dehesa” ecosystems and shrubby oak ecosystems. The results obtained by a global PCA analysis indicated that both tree size and dominant species influenced the ordination of the 40 forest stands. In general, carabids were more sensitive to changes in forest heterogeneity and responded more clearly to the analysed structural variables than the understory vegetation, although the species richness of both groups was significantly correlated and higher in case of oak forests. Pine forest ecosystems were characterised by the lowest species richness for both taxonomical groups, the lowest plant diversity and by the lowest coefficients of variation and, consequently, low structural heterogeneity. As a result, it was very difficult to discriminate the effects of the spatial heterogeneity and the dominant tree species on biodiversity.     

Molecular,morphological and pathogenic diversity of Sclerotinia sclerotiorum isolates from common bean (Phaseolus vulgaris) fields in Argentina

White mould, caused by Sclerotinia sclerotiorum, is one of the most threatening fungal diseases occurring across major bean production regions worldwide. In Argentina, under favourable weather conditions, up to 100% seed yield losses occur on susceptible common bean cultivars. The aim of this study was to characterize the diversity of S. sclerotiorum isolates from six dry bean fields in the main production area of Argentina by means of molecular, morphological (mycelium colour, number and pattern of sclerotia distribution) and pathogenic approaches. Among 116 isolates analysed, high genotypic and morphological variability was observed. A total of 52 mycelial compatibility groups (MCGs) and 59 URPs (universal rice primers) molecular haplotypes were found. All the MCGs were location specific, while only 12% of the URP haplotypes were shared among locations. The molecular analysis of variance revealed a significant differentiation among populations, with higher genetic variability within the populations analysed than among them. The aggressiveness of the isolates towards bean seedlings was assessed in the greenhouse. Most of the isolates were highly aggressive, while no variation among locations was observed. The information generated in the present study provides, for the first time, information on the variability of S. sclerotiorum associated with white mould in the main common bean production area in Argentina. In addition, the findings suggest the occurrence of both clonal and sexual reproduction in the populations analysed. This work contributes to the development of sustainable management strategies in bean production aimed to minimize yield losses due to white mould.