Differential expression of TAR DNA-binding protein (TDP-43) in the central nervous system of horses afflicted with equine motor neuron disease (EMND): a preliminary study of a potential pathologic marker

Equine motor neuron disease (EMND) is a neurodegenerative disorder of unknown etiology affecting horses worldwide. Trans-Active Response DNA Binding Protein of 43?kDa (TDP-43) has been reported in the central nervous system (CNS) of several neurodegenerative conditions in humans including Amyotrophic Lateral Sclerosis (ALS) and assumed to play role in the disease. We examined whether horses afflicted with EMND express the TDP-43 in CNS. Ten horses with EMND and 6 controls of different ages and breed we enrolled. Detection of presence of TDP-43 protein in the CNS was analyzed by immunohistochemical staining using rabbit anti-human TARDBP (TDP-43) polyclonal antibody. Formalin fixed neuronal tissues from medulla, cervical, and lumbar spinal cord were harvested from EMND and from control horses. Sections were assigned randomly to TDP-43 treated or rabbit anti-IgG as control. Nuclear staining of TDP-43 was detected in one of the neural tissues of 75?% of EMND-positive and 0 of 0?% of control horses in the central nervous system (medulla, and/or cervical spinal cord and/or lumbar spinal cord). TDP-43 antibody was detected in the nucleus of EMND horses and no cytoplasmic staining was noted. As in ALS, there was no pattern of age clustering associated with the detection of TDP-43. This is the first report on the staining of TDP-43 in neuronal tissues of horses and suggests that TDP-43 may play a role in the pathogenesis of EMND. Further studies are needed to elucidate the etiologic role of this protein in the diseases.     

Accumulation and depletion kinetics of erythromycin in rainbow trout (Oncorhynchus mykiss)

Erythromycin is an antimicrobial agent recommended for the control and treatment of diseases caused by gram-positive bacteria. Few studies, however, have determined the metabolic and pharmacokinetic aspects of this antimicrobial agent in fish. The aim of the present study, therefore, was to determine the accumulation and depletion time of erythromycin after administration of medicated feed containing 52 mg kg(-1) body weight day(-1) for 8 days in rainbow trout (Oncorhynchus mykiss). Results were analyzed following the European Agency for Evaluation of Medicinal Products guidelines. We measured a withdrawal time of 187°C-day (°C-day=water temperature×days), lower than the value (500°C-day) recommended by Council Directive 2004/28/EC for veterinary medicinal products. Our results provide data to establish therapeutic regimens for the use of erythromycin in aquaculture.     

Evaluation of two cocktails containing ESAT-6, CFP-10 and Rv-3615c in the intradermal test and the interferon-γ assay for diagnosis of bovine tuberculosis

The intradermal tuberculin tests and the interferon-gamma (IFN-γ) assay are the principal tests used worldwide for the ante-mortem diagnosis of bovine tuberculosis. The conventional reagent currently in use in these tests is purified protein derivative (PPD) tuberculin obtained from Mycobacterium bovis culture. The components of PPD are poorly characterized and difficult to standardize. To overcome this issue, antigens specific to the Mycobacterium tuberculosis complex are being studied. Here we have assessed the biological potency of ESAT-6, CFP-10 and Rv-3615c presented as peptide or recombinant protein cocktails in comparison with the standard bovine PPD used routinely in Spanish eradication campaigns. The study was performed in cattle (n=23) from a herd with natural M. bovis infection. Animals were simultaneously injected with PPD and the peptide and protein cocktails. The percentages of cattle reacting positively to single intradermal test were 60.9% (bovine PPD), 47.8% (peptide cocktail) and 60.9% (protein cocktail), with no significant difference between the actual skin fold thickness increases (p>0.05). The IFN-γ assay detected 60.9% of animals when stimulation was performed with bovine PPD, but decreased to 52.2% when stimulation was performed with the peptide cocktail and to 47.8% when stimulation was performed with the protein cocktail. However, no significant differences were found between IFN-γ responder frequencies (p>0.05). These results show a potential use of these defined reagents for in vivo tuberculosis diagnosis.     

Comparing silvopastoral systems and prospects in eight regions of the world

Silvopasture systems combine trees, forage, and livestock in a variety of different species and management regimes, depending on the biophysical, economic, cultural, and market factors in a region. We describe and compare actual farm practices and current research trials of silvopastoral systems in eight regions within seven countries of the world: Misiones and Corrientes provinces, Argentina; La Pampa province, Argentina; northwestern Minas Gerais, Brazil; the Aysén region of Patagonia, Chile; the North Island of New Zealand; the Southeast United States; Paraguay; and Uruguay. Some countries use native trees and existing forests; some use plantations, particularly of exotic species. Natural forest silvopasture systems generally add livestock in extensive systems, to capture the benefits of shade, forage, and income diversification without much added inputs. Plantation forest systems are more purposive and intensive, with more focus on joint production and profits, for small owners, large ranches, and timber companies. Trends suggest that more active management of both natural and planted silvopastoral systems will be required to enhance joint production of timber and livestock, achieve income diversification and reduce financial risk, make more profit, improve environmental benefits, and realize more resilience to adapt to climate change.     

Learning by doing: a participatory methodology for systematization of experiments with agroforestry systems, with an example of its application

Participatory research methods have helped scientists to understand how farmers experiment and to seek partnerships with farmers in developing technologies with enhanced relevance and adoption. This paper reports on the development of a participatory methodology to systematize long-term experimentation with agroforestry systems carried out in a hotspot of biodiversity by non-governmental organizations and local farmers. A methodological guide for systematization and techniques used for Participatory Rural Appraisal formed the basis of our work. We propose an analytical framework that recognizes systems of reflexive and learning interactions, in order to make the learned lessons explicit. At the process level, the main lessons and recommendations are as follows. It is important to establish partnerships to conduct innovative and complex experimentation with agroforest. Participatory systematization allows us to improve the methodological aspects of design, implementation and management of on-farm participatory experimentation. It also serves to synthesize the main findings and to extract lessons from agroforestry systems experiments. It fosters the technical improvement of agroforestry systems. It creates possibilities for reflection on agroforestry systems by farmers, extensionists and researchers, as well as their learning with respect to management of such systems. The findings are placed in the context of current theory on participatory experimentation in agriculture. Extractive and interactive approaches help to produce rich insights of mutual interest through collaboration by identifying local, regional and global convergences, complementarities, and conflicts of interest; which affect the advance of new eco-friendly technologies, to both improve the livelihoods and to reverse biodiversity loss and environmental degradation.     

Seroprevalence and risk factors for Neospora caninum in sheep in the state Minas Gerais, southeastern Brazil

The aim of this study was to determine the prevalence and risk factors associated with infection due to Neospora caninum in serum samples from 488 sheep originating from 63 farms in 63 municipalities distributed across eight of the twelve mesoregions of the state Minas Gerais, southeastern Brazil. For detection of N. caninum the sheep serum samples were subjected to the indirect fluorescence antibody test (IFAT ≥ 50). To identify the risk factors associated with infection due to N. caninum a questionnaire was filled out for each herd by interviewing, the individual responsible for the herd, demanding information on the general characteristics of the property. Sixty-four sheep sera (13.1%; 95% CI=10.3-16.4) presented IgG-specific anti-N. caninum antibodies with the following titers: 50 (49; 76.6%), 100 (7; 10.9%), 200 (4; 6.2%), 400 (3; 4.7%) and 800 (1; 1.6%). The prevalence of infected sheep per mesoregion ranged from 0 to 28.1%. Out of the 63 farms sampled, 31 (49.2%; 95% CI=36.4-62.1) presented at least one seropositive sheep. No significant association was found between the presence of anti-N. caninum antibodies and the risk factors evaluated on the farms, except for the mesoregion variable (p=0.004; OR=0.429; CI95%=0.182-1.008). These results indicate that there is a need for additional research to define the epidemiological importance of this parasite as a cause of reproductive problems in sheep herds in Minas Gerais.     

Advances in diagnosis of protozoan diseases

Microscopy still remains the gold standard procedure for the diagnosis of many protozoan infections in animals, but the specific identification requires skilled and experienced personnel. Immunoassays, detecting antibodies or specific protozoan antigens, have been developed but often lack sensitivity and specificity due to close relationship between many protozoa. Recent research has focussed almost exclusively on molecular based techniques for the identification and quantification of parasite DNA in samples. Opinion differ on most appropriate targets to use and there are very few diagnostic kits available making comparison between laboratories difficult. Future research needs to focus on robust, cheap field diagnostic assays.     

First report of Lagochilascaris (Nematoda: Ascarididae) eggs in a public park in Southern Brazil

Public parks, especially in developing countries, are places where stray animals run free and may contaminate the environment with different species of parasites. In an evaluation of environmental sanitation of these sites, soil samples were collected monthly from public parks in the Pelotas city, Rio Grande do Sul State, Southern Brazil. Eggs of the nematode Lagochilascaris sp. were found in a public playground. This is the first report of identification of this nematode in Southern Brazil.     

Clinical presentation,treatment and possible causes of persistent endometrial cups illustrated by two cases

Persistent endometrial cups are relatively rare in the mare and the occurrence in 2 successive pregnancies, as described in this issue, is an intriguing finding. This article describes an additional 2 cases of endometrial cups persisting in excess of 12 months in mares that had experienced pregnancy loss. Both mares demonstrated irregular ovarian activity in the form of repeated formation of haemorrhagic anovulatory follicles. A definitive diagnosis was made by visualisation of cup tissue by hysteroscopy and demonstration of equine chorionic gonadotropin (eCG) in the mares' serum. Biopsy of endometrial cups was made under visual direction and the mares were treated by chemical curettage with kerosene. The clinical presentation, treatment and possible causes of persistent endometrial cups are reviewed and discussed.