Protease-Sensitive and -Resistant Forms of Human and Murine Alpha-Synucleins in Distinct Brain Regions of Transgenic Mice (M83) Expressing the Human Mutated A53T Protein.

Human neurodegenerative diseases associated with the misfolding of the alpha-synuclein (aS) protein (synucleinopathies) are similar to prion diseases to the extent that lesions are spread by similar molecular mechanisms. In a transgenic mouse model (M83) overexpressing a mutated (A53T) form of human aS, we had previously found that Protein Misfolding Cyclic Amplification (PMCA) triggered the aggregation of aS, which is associated with a high resistance to the proteinase K (PK) digestion of both human and murine aS, a major hallmark of the disease-associated prion protein. In addition, PMCA was also able to trigger the aggregation of murine aS in C57Bl/6 mouse brains after seeding with sick M83 mouse brains. Here, we show that intracerebral inoculations of M83 mice with C57Bl/6-PMCA samples strikingly shortens the incubation period before the typical paralysis that develops in this transgenic model, demonstrating the pathogenicity of PMCA-aggregated murine aS. In the hind brain regions of these sick M83 mice containing lesions with an accumulation of aS phosphorylated at serine 129, aS also showed a high PK resistance in the N-terminal part of the protein. In contrast to M83 mice, old APPxM83 mice co-expressing human mutated amyloid precursor and presenilin 1 proteins were seen to have an aggregation of aS, especially in the cerebral cortex, hippocampus and striatum, which also contained the highest load of aS phosphorylated at serine 129. This was proven by three techniques: a Western blot analysis of PK-resistant aS; an ELISA detection of aS aggregates; or the identification of aggregates of aS using immunohistochemical analyses of cytoplasmic/neuritic aS deposits. The results obtained with the D37A6 antibody suggest a higher involvement of murine aS in APPxM83 mice than in M83 mice. Our study used novel tools for the molecular study of synucleinopathies, which highlight similarities with the molecular mechanisms involved in prion diseases.

Impact of heat and cold waves on female cattle mortality beyond the effect of extreme temperatures.

Although heat and cold temperatures are known to have an impact on cattle mortality, no study has evidenced and quantified the influence of the prolonged exposure to extreme temperatures beyond the single effect of daily temperatures. We defined a heat (or cold) wave by a continuous variable indicating the number of successive days with temperatures above (or below) a given threshold. For heat wave, the threshold was set to the 95th or 99th percentile of the mean daily temperature distribution and for cold wave to the 1st or 5th percentile. We collected female cattle mortality data by type of production and age classes between 2001 and 2015 for 100 iso-hygro-thermal areas in France. We used time-series analyses to estimate the area-specific heat wave- and cold wave-mortality relationships. Then, we applied meta-analyses to pool area-specific effects at the country level for each definition of heat and cold wave. For each type of production and age classes, our models predicted symmetrical relationships between temperature and mortality, with a temperature range of minimum mortality located approximately between 15 and 20 °CTHI in most categories. Outside that range, relative risks between 1.3 and 2.5 were estimated for extreme cold temperatures and relative risks between 1.1 and 1.5 were estimated for extreme hot temperatures depending on age categories and production type. Our results indicated that a prolonged exposure to high (or low) temperatures caused a significant increase on mortality (up to 40% during heat waves and 23% for cold waves, depending on type of production and age classes), in addition to the effect of extreme temperature alone. This additional mortality risk increased along with the duration and intensity of the exposure. Our results suggest that not discriminating the effect of the prolonged exposure to extreme temperature, may overestimate the effect of temperature alone on mortality.

Oral Exposure to Paraquat Triggers Earlier Expression of Phosphorylated α-Synuclein in the Enteric Nervous System of A53T Mutant Human α-Synuclein Transgenic Mice.

The misfolded α-synuclein protein, phosphorylated at serine 129 (pSer129 α-syn), is the hallmark of Parkinson disease (PD). Detected also in the enteric nervous system (ENS), it supports the recent theory that PD could start in the gut, rather than the brain. In a previous study, using a transgenic mouse model of human synucleinopathies expressing the A53T mutant α-synuclein (TgM83), in which a neurodegenerative process associated with α-synuclein occurs spontaneously in the brain, we have shown earlier onset of pSer129 α-syn in the ENS. Here, we used this model to study the impact of paraquat (PQ) a neurotoxic herbicide incriminated in PD in agricultural workers) on the enteric pSer129 α-syn expression in young mice. Orally delivered in the drinking water at 10 mg/kg/day for 6-8 weeks, the impact of PQ was measured in a time-dependent manner on weight, locomotor abilities, pSer129 α-syn, and glial fibrillary acidic protein (GFAP) expression levels in the ENS. Remarkably, pSer129 α-syn was detected in ENS earlier under PQ oral exposure and enteric GFAP expression was also increased. These findings bring additional support to the theory that neurotoxic agents such as PQ initiate idiopathic PD after oral delivery.

'Prion-like' propagation of the synucleinopathy of M83 transgenic mice depends on the mouse genotype and type of inoculum.

The M83 transgenic mouse is a model of human synucleinopathies that develops severe motor impairment correlated with accumulation of the pathological Ser129-phosphorylated α-synuclein (α-synP ) in the brain and spinal cord. M83 disease can be accelerated by intracerebral inoculation of brain extracts from sick M83 mice. This has also recently been described using peripheral routes, injecting recombinant preformed α-syn fibrils into the muscle or the peritoneum. Here, we inoculated homozygous and/or hemizygous M83 neonates via the intraperitoneal and/or intracerebral routes with two different brain extracts: one from sick M83 mice inoculated with brain extract from other sick M83 mice, and the other derived from a human multiple system atrophy source passaged in M83 mice. Detection of α-synP using ELISA and western blot confirmed the disease in mice. The distribution of α-synP in the central nervous system was similar, independently of the inoculum or inoculation route, consistent with previous studies describing M83 disease. ELISA tests revealed higher levels of α-synP in homozygous than in hemizygous sick M83 mice, at least after IC inoculation. Interestingly, the immunoreactivity of α-synP detected by ELISA was significantly lower in M83 mice inoculated with the multiple system atrophy inoculum than in M83 mice inoculated with the M83 inoculum, at the first two passages. 'Prion-like' propagation of the synucleinopathy up to the clinical disease was accelerated by both intracerebral and intraperitoneal inoculations of brain extracts from sick mice. This acceleration, however, depends on the levels of α-syn expression by the mouse and the type of inoculum.

A tool to support the identification of suspect cases of exotic diseases in cattle.

Maintaining vigilance with regard to the introduction of exotic diseases is a challenge, particularly because these diseases are numerous, some are not well known, and they are not immediately suspected by people in day-to-day practice, specifically veterinary practitioners. The objective of this article is to present a tool to support the identification of suspect cases of exotic diseases in cattle, based on a Bayesian approach. A list of 22 exotic diseases in mainland France was selected mainly on the basis of their potential consequences if introduced, and the ability to detect them on a clinical basis. In response of a set of epidemio-clinical criteria observed in the field this tool provides a list of exotic diseases by descending order of likelihood. The tool's performance was assessed by simulation. When simulating epidemio-clinical observations of each of the 22 diseases included in the tool with some uncertainty, the right disease was ranked in the first place between 83.8% and 100% of the times, and always in the five most likely diseases. Even when some noise was introduced in the epidemio-clinical observations simulated by addition of criteria non-characteristic of the simulated diseases, the right disease was always in the five most likely diseases. This tool could be usefully included in a global approach aiming to improve vigilance against exotic diseases.

Assessment of fallen equine data in France and their usefulness for epidemiological investigations.

Quantitative information about equine mortality is relatively scarce, yet it could be of great value for epidemiology purposes. Several European projects based on the exploitation of data from rendering plants have been developed to improve livestock surveillance. Similar data are available for equines in France but have never been studied to date. The objective of this research was to evaluate the potential of the French Ministry of Agriculture's Fallen Stock Data Interchange (FSDI) database to provide quantitative mortality information on the French equine population. The quality of FSDI equine data from 2011 to 2014 was assessed using complementary data registered in the French equine census database, SIRE. Despite a perfectible quality, the FSDI database proved to be a valuable source for studying the basal patterns of mortality over time in the French equine population as illustrated by the spatial representation of the number of deaths. However, improvements in the FSDI database are needed, in particular regarding the registration of animal identification numbers, in order to detail equine mortality for epidemiology purposes.

Iso-population partition: An innovative epidemiological approach to mapping and analyzing spatially aggregated data.

In epidemiology, data are often aggregated using administrative boundaries or regular spatial lattices. Iso-population partitioning methods allow the aggregation of small units for which population data are available into larger units that are contiguous, as compact as possible, and have a similar population size. The objective of this paper was to study the influence of three spatial data aggregation approaches on data visualization and data analysis: iso-populated units (IPUs), administrative units, and iso-geometric units. This study was conducted using results and simulations from the brucellosis clinical surveillance system for dairy cattle in France. Our findings indicate that using spatial partitioning methods for generating IPUs enhances the ability to interpret the spatial distribution of epidemiological indicators under study. In addition, it provides information on population density and improves the consistency of the power of statistical tests across units. By defining the target population size per spatial unit, IPUs can be used to control the statistical power of a study. Finally, by adding criteria based on environmental factors to generate spatial units, they can be used to control the variation of exposure to these factors within the units.

An optimal cut-off point for the calving interval may be used as an indicator of bovine abortions.

The bovine abortion surveillance system in France aims to detect as early as possible any resurgence of bovine brucellosis, a disease of which the country has been declared free since 2005. It relies on the mandatory notification and testing of each aborting cow, but under-reporting is high. This research uses a new and simple approach which considers the calving interval (CI) as a "diagnostic test" to determine optimal cut-off point c and estimate diagnostic performance of the CI to identify aborting cows, and herds with multiple abortions (i.e. three or more aborting cows per calving season). The period between two artificial inseminations (AI) was considered as a "gold standard". During the 2006-2010 calving seasons, the mean optimal CI cut-off point for identifying aborting cows was 691 days for dairy cows and 703 days for beef cows. Depending on the calving season, production type and scale at which c was computed (individual or herd), the average sensitivity of the CI varied from 42.6% to 64.4%; its average specificity from 96.7% to 99.7%; its average positive predictive value from 27.6% to 65.4%; and its average negative predictive value from 98.7% to 99.8%. When applied to the French bovine population as a whole, this indicator identified 2-3% of cows suspected to have aborted, and 10-15% of herds suspected of multiple abortions. The optimal cut-off point and CI performance were consistent over calving seasons. By applying an optimal CI cut-off point to the cattle demographics database, it becomes possible to identify herds with multiple abortions, carry out retrospective investigations to find the cause of these abortions and monitor a posteriori compliance of farmers with their obligation to report abortions for brucellosis surveillance needs. Therefore, the CI could be used as an indicator of abortions to help improve the current mandatory notification surveillance system.

Respective influence of veterinarians and local institutional stakeholders on the event-driven surveillance system for bovine brucellosis in France.

BACKGROUND: The event-driven surveillance system for bovine brucellosis implemented in France aims to ensure the early detection of cases of bovine brucellosis, a disease of which the country has been declared free since 2005. It consists of mandatory notification of bovine abortions by farmers and veterinarians. However, as underlined by a previous qualitative study, several factors influence the decision-making process of actors in the field. This process is particularly influenced by the level of cooperation between institutional stakeholders in their département (a French département being an administrative and territorial unit), veterinarians and farmers. In this context, the objectives of this study were 1) to quantify the respective influence of veterinarians and all local institutional stakeholders on the proportion of notifying farmers and identify which actors have most influence on farmers' decisions; 2) to analyse whether the influence of veterinarians is correlated with that of local institutional stakeholders. RESULTS: In addition to factors relating to the farm itself (production type and herd size), the proportion of notifying farmers was influenced by the number of veterinarians per practice and the veterinary practice's membership of a technical association. This proportion was also influenced by unknown factors relating to the veterinary practice and, to a lesser extent, the département in which the farm was located. There was no correlation between variability in the proportion of notifying farmers among veterinary practices per département and the effect of the département itself. CONCLUSION: To our knowledge, this is the first study to quantify the influence of veterinarians and local institutional stakeholders on the notification process for a mandatory disease. In addition to carrying out regulatory interventions, veterinarians play a major role in encouraging farmers to participate in the surveillance systems. The results of this study, combined with a previous qualitative study, shed light on the need to consolidate the involvement of veterinarians and local stakeholders in the organisation of surveillance by national institutional bodies.

Detection of Disease-associated α-synuclein by Enhanced ELISA in the Brain of Transgenic Mice Overexpressing Human A53T Mutated α-synuclein.

In addition to established methods like Western blot, new methods are needed to quickly and easily quantify disease-associated α-synuclein (αS(D)) in experimental models of synucleopathies. A transgenic mouse line (M83) over-expressing the human A53T αS and spontaneously developing a dramatic clinical phenotype between eight and 22 months of age, characterized by symptoms including weight loss, prostration, and severe motor impairment, was used in this study. For molecular analyses of αS(D) (disease-associated αS) in these mice, an ELISA was designed to specifically quantify αS(D) in sick mice. Analysis of the central nervous system in this mouse model showed the presence of αS(D) mainly in the caudal brain regions and the spinal cord. There were no differences in αS(D) distribution between different experimental conditions leading to clinical disease, i.e., in uninoculated and normally aging transgenic mice and in mice inoculated with brain extracts from sick mice. The specific detection of αS(D) immunoreactivity using an antibody against Ser129 phosphorylated αS by ELISA essentially correlated with that obtained by Western blot and immunohistochemistry. Unexpectedly, similar results were observed with several other antibodies against the C-terminal part of αS. The propagation of αS(D), suggesting the involvement of a "prion-like" mechanism, can thus be easily monitored and quantified in this mouse model using an ELISA approach.

Quantifying the influence of ambient temperature on dairy and beef cattle mortality in France from a time-series analysis.

In the context of climate change, the frequency and severity of extreme weather events are expected to increase in temperate regions, and potentially have a severe impact on farmed cattle through production losses or deaths. In this study, we used distributed lag non-linear models to describe and quantify the relationship between a temperature-humidity index (THI) and cattle mortality in 12 areas in France. THI incorporates the effects of both temperature and relative humidity and was already used to quantify the degree of heat stress on dairy cattle because it does reflect physical stress deriving from extreme conditions better than air temperature alone. Relationships between daily THI and mortality were modeled separately for dairy and beef cattle during the 2003-2006 period. Our general approach was to first determine the shape of the THI-mortality relationship in each area by modeling THI with natural cubic splines. We then modeled each relationship assuming a three-piecewise linear function, to estimate the critical cold and heat THI thresholds, for each area, delimiting the thermoneutral zone (i.e. where the risk of death is at its minimum), and the cold and heat effects below and above these thresholds, respectively. Area-specific estimates of the cold or heat effects were then combined in a hierarchical Bayesian model to compute the pooled effects of THI increase or decrease on dairy and beef cattle mortality. A U-shaped relationship, indicating a mortality increase below the cold threshold and above the heat threshold was found in most of the study areas for dairy and beef cattle. The pooled estimate of the mortality risk associated with a 1°C decrease in THI below the cold threshold was 5.0% for dairy cattle [95% posterior interval: 4.4, 5.5] and 4.4% for beef cattle [2.0, 6.5]. The pooled mortality risk associated with a 1°C increase above the hot threshold was estimated to be 5.6% [5.0, 6.2] for dairy and 4.6% [0.9, 8.7] for beef cattle. Knowing the thermoneutral zone and temperature effects outside this zone is of primary interest for farmers because it can help determine when to implement appropriate preventive and mitigation measures.

Devising an indicator to detect mid-term abortions in dairy cattle: a first step towards syndromic surveillance of abortive diseases.

Bovine abortion surveillance is essential for human and animal health because it plays an important role in the early warning of several diseases. Due to the limited sensitivity of traditional surveillance systems, there is a growing interest for the development of syndromic surveillance. Our objective was to assess whether, routinely collected, artificial insemination (AI) data could be used, as part of a syndromic surveillance system, to devise an indicator of mid-term abortions in dairy cattle herds in France. A mid-term abortion incidence rate (MAIR) was computed as the ratio of the number of mid-term abortions to the number of female-weeks at risk. A mid-term abortion was defined as a return-to-service (i.e., a new AI) taking place 90 to 180 days after the previous AI. Weekly variations in the MAIR in heifers and parous cows were modeled with a time-dependent Poisson model at the département level (French administrative division) during the period of 2004 to 2010. The usefulness of monitoring this indicator to detect a disease-related increase in mid-term abortions was evaluated using data from the 2007-2008 episode of bluetongue serotype 8 (BT8) in France. An increase in the MAIR was identified in heifers and parous cows in 47% (n = 24) and 71% (n = 39) of the departements. On average, the weekly MAIR among heifers increased by 3.8% (min-max: 0.02-57.9%) when the mean number of BT8 cases that occurred in the previous 8 to 13 weeks increased by one. The weekly MAIR among parous cows increased by 1.4% (0.01-8.5%) when the mean number of BT8 cases occurring in the previous 6 to 12 weeks increased by one. These results underline the potential of the MAIR to identify an increase in mid-term abortions and suggest that it is a good candidate for the implementation of a syndromic surveillance system for bovine abortions.

Was the French clinical surveillance system of bovine brucellosis influenced by the occurrence and surveillance of other abortive diseases?

The bovine brucellosis clinical surveillance system implemented in France aims to detect early any case of bovine brucellosis, a disease of which the country has been declared free since 2005. It relies on the mandatory notification of every bovine abortion. Following the spread of the Schmallenberg virus (SBV) in France in 2012 and 2013, and the implementation in 2012 of a clinical surveillance programme of Q fever based on abortion notifications in ten pilot départements, our objective was to study whether these two events influenced the brucellosis clinical surveillance system. The proportion of notifying farmers was analyzed over each semester from June 1, 2009 to June 30, 2013 according to the size and production type of herds, SBV status of départements and the implementation of the Q fever surveillance. Our analysis showed a slight increase in the proportion of notifying farmers as départements became infected by SBV, and after the implementation of Q fever surveillance (during the first semester of 2013). These variations might be explained by an increase in abortion occurrence (congenital deformities in newborns, due to SBV) and/or by an increase in farmers' and veterinarians' awareness (due to the spread of SBV and the implementation of the Q fever surveillance). These results highlight the difficulties in interpreting variations in the proportion of notifying farmers as a consequence of an increase in abortion occurrence. As bovine abortion surveillance can play an important role in the early warning for several diseases, there is a need to explore other ways to monitor abortions in cattle, such as syndromic surveillance using the dates of artificial insemination or calving data.

Alpha-synuclein spreading in M83 mice brain revealed by detection of pathological α-synuclein by enhanced ELISA.

BACKGROUND: The accumulation of misfolded proteins appears as a fundamental pathogenic process in human neurodegenerative diseases. In the case of synucleinopathies such as Parkinson's disease (PD) or dementia with Lewy bodies (DLB), the intraneuronal deposition of aggregated alpha-synuclein (αS) is a major characteristic of the disease, but the molecular basis distinguishing the disease-associated protein (αSD) from its normal counterpart remains poorly understood. However, recent research suggests that a prion-like mechanism could be involved in the inter-cellular and inter-molecular propagation of aggregation of the protein within the nervous system. RESULTS: Our data confirm our previous observations of disease acceleration in a transgenic mouse line (M83) overexpressing a mutated (A53T) form of human αS, following inoculation of either brain extracts from sick M83 mice or fibrillar recombinant αS. A similar phenomenon is observed following a "second passage" in the M83 mouse model, including after stereotactic inoculations into the hippocampus or cerebellum. For further molecular analyses of αSD, we designed an ELISA test that identifies αSD specifically in sick mice and in the brain regions targeted by the pathological process in this mouse model. αSD distribution, mainly in the caudal brain regions and spinal cord, overall appears remarkably uniform, whatever the conditions of experimental challenge. In addition to specific detection of αSD immunoreactivity using an antibody against Ser129 phosphorylated αS, similar results were observed in ELISA with several other antibodies against the C-terminal part of αS, including an antibody against non phosphorylated αS. This also indicated consistent immunoreactivity of the murine αS protein specifically in the affected brain regions of sick mice. CONCLUSIONS: Prion-like behaviour in propagation of the disease-associated αS was confirmed with the M83 transgenic mouse model, that could be followed by an ELISA test. The ELISA data question their possible relationship with the conformational differences between the disease-associated αS and its normal counterpart.

Assessment of the impact of the 2003 and 2006 heat waves on cattle mortality in France.

OBJECTIVES: While several studies have highlighted and quantified human mortality during the major heat waves that struck Western Europe in 2003 and 2006, the impact on farm animals has been overlooked. The aim of this study was to assess the effect of these two events on cattle mortality in France, one of the most severely impacted countries. METHODS: Poisson regressions were used to model the national baseline for cattle mortality between 2004 and 2005 and predict the weekly number of expected deaths in 2003 and 2006 for the whole cattle population and by subpopulation based on age and type of production. Observed and estimated values were compared to identify and quantify excess mortality. The same approach was used at a departmental scale (a French department being an administrative and territorial division) to assess the spatio-temporal evolution of the mortality pattern. RESULTS: Overall, the models estimated relative excess mortality of 24% [95% confidence interval: 22-25%] for the two-week heat wave of 2003, and 12% [11-14%] for the three-week heat wave of 2006. In 2003, most cattle subpopulations were impacted during the heat wave and some in the following weeks too. In 2006, cattle subpopulations were impacted for a limited time only, with no excess mortality at the beginning or after the heat wave. No marked differences in cattle mortality were found among the different subpopulations by age and type of production. The implications of these results for risk prevention are discussed.

Defining syndromes using cattle meat inspection data for syndromic surveillance purposes: a statistical approach with the 2005-2010 data from ten French slaughterhouses.

BACKGROUND: The slaughterhouse is a central processing point for food animals and thus a source of both demographic data (age, breed, sex) and health-related data (reason for condemnation and condemned portions) that are not available through other sources. Using these data for syndromic surveillance is therefore tempting. However many possible reasons for condemnation and condemned portions exist, making the definition of relevant syndromes challenging.The objective of this study was to determine a typology of cattle with at least one portion of the carcass condemned in order to define syndromes. Multiple factor analysis (MFA) in combination with clustering methods was performed using both health-related data and demographic data. RESULTS: Analyses were performed on 381,186 cattle with at least one portion of the carcass condemned among the 1,937,917 cattle slaughtered in ten French abattoirs. Results of the MFA and clustering methods led to 12 clusters considered as stable according to year of slaughter and slaughterhouse. One cluster was specific to a disease of public health importance (cysticercosis). Two clusters were linked to the slaughtering process (fecal contamination of heart or lungs and deterioration lesions). Two clusters respectively characterized by chronic liver lesions and chronic peritonitis could be linked to diseases of economic importance to farmers. Three clusters could be linked respectively to reticulo-pericarditis, fatty liver syndrome and farmer's lung syndrome, which are related to both diseases of economic importance to farmers and herd management issues. Three clusters respectively characterized by arthritis, myopathy and Dark Firm Dry (DFD) meat could notably be linked to animal welfare issues. Finally, one cluster, characterized by bronchopneumonia, could be linked to both animal health and herd management issues. CONCLUSION: The statistical approach of combining multiple factor analysis with cluster analysis showed its relevance for the detection of syndromes using available large and complex slaughterhouse data. The advantages of this statistical approach are to i) define groups of reasons for condemnation based on meat inspection data, ii) help grouping reasons for condemnation among a list of various possible reasons for condemnation for which a consensus among experts could be difficult to reach, iii) assign each animal to a single syndrome which allows the detection of changes in trends of syndromes to detect unusual patterns in known diseases and emergence of new diseases.

Assessing the mandatory bovine abortion notification system in France using unilist capture-recapture approach.

The mandatory bovine abortion notification system in France aims to detect as soon as possible any resurgence of bovine brucellosis. However, under-reporting seems to be a major limitation of this system. We used a unilist capture-recapture approach to assess the sensitivity, i.e. the proportion of farmers who reported at least one abortion among those who detected such events, and representativeness of the system during 2006-2011. We implemented a zero-inflated Poisson model to estimate the proportion of farmers who detected at least one abortion, and among them, the proportion of farmers not reporting. We also applied a hurdle model to evaluate the effect of factors influencing the notification process. We found that the overall surveillance sensitivity was about 34%, and was higher in beef than dairy cattle farms. The observed increase in the proportion of notifying farmers from 2007 to 2009 resulted from an increase in the surveillance sensitivity in 2007/2008 and an increase in the proportion of farmers who detected at least one abortion in 2008/2009. These patterns suggest a raise in farmers' awareness in 2007/2008 when the Bluetongue Virus (BTV) was detected in France, followed by an increase in the number of abortions in 2008/2009 as BTV spread across the country. Our study indicated a lack of sensitivity of the mandatory bovine abortion notification system, raising concerns about the ability to detect brucellosis outbreaks early. With the increasing need to survey the zoonotic Rift Valley Fever and Q fever diseases that may also cause bovine abortions, our approach is of primary interest for animal health stakeholders to develop information programs to increase abortion notifications. Our framework combining hurdle and ZIP models may also be applied to estimate the completeness of other clinical surveillance systems.

Specific pesticide-dependent increases in α-synuclein levels in human neuroblastoma (SH-SY5Y) and melanoma (SK-MEL-2) cell lines.

Epidemiological studies indicate a role of genetic and environmental factors in Parkinson's disease involving alterations of the neuronal α-synuclein (α-syn) protein. In particular, a relationship between Parkinson's disease and occupational exposure to pesticides has been repeatedly suggested. Our objective was to precisely assess changes in α-syn levels in human neuroblastoma (SH-SY5Y) and melanoma (SK-MEL-2) cell lines following acute exposure to pesticides (rotenone, paraquat, maneb, and glyphosate) using Western blot and flow cytometry. These human cell lines express α-syn endogenously, and overexpression of α-syn (wild type or mutated A53T) can be obtained following recombinant adenoviral transduction. We found that endogenous α-syn levels in the SH-SY5Y neuroblastoma cell line were markedly increased by paraquat, and to a lesser extent by rotenone and maneb, but not by glyphosate. Rotenone also clearly increased endogenous α-syn levels in the SK-MEL-2 melanoma cell line. In the SH-SY5Y cell line, similar differences were observed in the α-syn adenovirus-transduced cells, with a higher increase of the A53T mutated protein. Paraquat markedly increased α-syn in the SK-MEL-2 adenovirus-transduced cell line, similarly for the wild-type or A53T proteins. The observed differences in the propensities of pesticides to increase α-syn levels are in agreement with numerous reports that indicate a potential role of exposure to certain pesticides in the development of Parkinson's disease. Our data support the hypothesis that pesticides can trigger some molecular events involved in this disease and also in malignant melanoma that consistently shows a significant but still unexplained association with Parkinson's disease.

Differentiation of prions from L-type BSE versus sporadic Creutzfeldt-Jakob disease.

We compared transmission characteristics for prions from L-type bovine spongiform encephalopathy and MM2-cortical sporadic Creutzfeldt-Jakob disease in the Syrian golden hamster and an ovine prion protein-transgenic mouse line and isolated distinct prion strains. Our findings suggest the absence of a causal relationship between these diseases, but further investigation is warranted.

Individual factors associated with L- and H-type Bovine Spongiform encephalopathy in France.

BACKGROUND: Cattle with L-type (L-BSE) and H-type (H-BSE) atypical Bovine Spongiform encephalopathy (BSE) were identified in 2003 in Italy and France respectively before being identified in other countries worldwide. As of December 2011, around 60 atypical BSE cases have currently been reported in 13 countries, with over one third in France. While the epidemiology of classical BSE (C-BSE) has been widely described, atypical BSEs are still poorly documented, but appear to differ from C-BSE. We analysed the epidemiological characteristics of the 12 cases of L-BSE and 11 cases of H-BSE detected in France from January 2001 to late 2009 and looked for individual risk factors. As L-BSE cases did not appear to be homogeneously distributed throughout the country, two complementary methods were used: spatial analysis and regression modelling. L-BSE and H-BSE were studied separately as both the biochemical properties of their pathological prion protein and their features differ in animal models. RESULTS: The median age at detection for L-BSE and H-BSE cases was 12.4 (range 8.4-18.7) and 12.5 (8.3-18.2) years respectively, with no significant difference between the two distributions. However, this median age differed significantly from that of classical BSE (7.0 (range 3.5-15.4) years). A significant geographical cluster was detected for L-BSE. Among animals over eight years of age, we showed that the risk of being detected as a L-BSE case increased with age at death. This was not the case for H-BSE. CONCLUSION: To the best of our knowledge this is the first study to describe the epidemiology of the two types of atypical BSE. The geographical cluster detected for L-BSE could be partly due to the age structure of the background-tested bovine population. Our regression analyses, which adjusted for the effect of age and birth cohort showed an age effect for L-BSE and the descriptive analysis showed a particular age structure in the area where the cluster was detected. No birth cohort effect was evident. The relatively small number of cases of atypical BSE and the few individual data available for the tested population limited our analysis to the investigation of age and cohort effect only. We conclude that it is essential to maintain BSE surveillance to further elucidate our findings.