Age-dependent impact of streptozotocin on metabolic endpoints and Alzheimer's disease pathologies in 3xTg-AD mice

Alzheimer's disease (AD) is a multifactorial neurodegenerative disease with a complex origin, thought to involve a combination of genetic, biological and environmental factors. Insulin dysfunction has emerged as a potential factor contributing to AD pathogenesis, particularly in individuals with diabetes, and among those with insulin deficiency or undergoing insulin therapy. The intraperitoneal administration of streptozotocin (STZ) is a widely used rodent model to explore the impact of insulin deficiency on AD pathology, although prior research predominantly focused on young animals, with no comparative analysis across different age groups. Our study aimed to fill this gap by analyzing the impact of insulin dysfunction in 7 and 23 months 3xTg-AD mice, that exhibit both amyloid and tau pathologies. Our objective was to elucidate the age-specific consequences of insulin deficiency on AD pathology. STZ administration led to insulin deficiency in the younger mice, resulting in an increase in cortical amyloid-β (Aβ) and tau aggregation, while tau phosphorylation was not significantly affected. Conversely, older mice displayed an unexpected resilience to the peripheral metabolic impact of STZ, while exhibiting an increase in both tau phosphorylation and aggregation without significantly affecting amyloid pathology. These changes were paralleled with alterations in signaling pathways involving tau kinases and phosphatases. Several markers of blood-brain barrier (BBB) integrity declined with age in 3xTg-AD mice, which might facilitate a direct neurotoxic effect of STZ in older mice. Overall, our research confirms the influence of insulin signaling dysfunction on AD pathology, but also advises careful interpretation of data related to STZ-induced effects in older animals.

Milk replacer feeding once or twice a day did not change the ruminal metabolomic profile and the microbial diversity of dairy calves from birth to weaning

In commercial dairy production systems, feeding calves once a day could be an alternative to reduce labor expenses. Several studies comparing once (OAD) versus twice (TAD) a day milk feeding systems have not evidenced differences in calf growth, rumen development, blood parameters or health scores, but impact on ruminal microbiota remains to be investigated. The objective of this study was to determine the effects of OAD or TAD on the establishment of the ruminal microbiota and its metabolic activity. Sixteen male calves (45.9 ± 5.7 kg at birth) were involved in the trial from birth to weaning (63 d). After the colostrum phase, 2 feeding programs based on a milk replacer were tested and calves were allocated to these programs on d 5. To study the establishment of the bacterial community, ruminal fluid was obtained from each calf one hour after the morning meal at 7 (d 7), 35 (d 35) and 63 (d 63) days of age. The ruminal metabolome was evaluated at a 7 d interval from d 1 to d 63. Ruminal microbiota and metabolite profiles were characterized by 16 S rRNA gene sequencing- and by H-NMR spectroscopy, respectively. Our results showed that feeding milk replacer once or twice a day did not change the ruminal microbiota and metabolites of dairy calves from birth to weaning. Microbial data showed that diversity and richness increased with age, suggesting a shift from an heterogeneous and less diverse community after birth (d 7) to a more diverse but homogeneous community at 35 and 63 d. These findings suggest that feeding milk once a day can be successfully applied to a calf feeding system without compromising microbial establishment and functions.

Is there a right time for dairy Alpine goat kid weaning: How does the weaning age of dairy Alpine goat kids affect their growth and behavior?

In dairy goat kids, weaning is often associated with poor growth leading to a decline in welfare and performance; however, little is known about optimal weaning practices. This study aimed to determine the optimal weaning age for dairy goat kids to maximize outcome measures of welfare related to growth, feed intake, and behavior. Thirty-six newborn female Alpine kids were blocked by weight and birth date, paired with a similar male companion and randomly allocated to one of the three weaning age treatments: 6 (6W), 8 (8W), and 10 wk (10W). Kids had ad libitum access to acidified milk replacer refilled twice daily, concentrates, hay, and water. Milk consumption was measured daily, and concentrate consumption, weekly. Ten behaviors were live observed on days -8, -4, 0, 6, and 12 relative to weaning (i.e., weaning day = 0). Kruskal-Wallis tests were used to assess differences from baseline between the 6W, 8W, and 10W treatments. Post hoc analysis using the Dwass, Steel, Critchlow-Fligner (DSCF) multiple comparison analysis was used to evaluate pairwise treatment differences based on two-sample Wilcoxon comparisons. Kids weaned at 10 wk had the greatest increase compared to baseline in concentrate consumption (P = 0.0160), and greatest decrease compared to baseline in vocalization (P = 0.0008) while both 8- and 10- wk kid's groups had the greatest increase compared to baseline in self-grooming time (P < 0.0001), and cross-sucking time (P = 0.0006). Kids weaned at 6 wk of age were found to have the smallest increase compared to baseline in concentrate consumption (P = 0.0160) and self-grooming time (P < 0.0001), and the greatest increase compared to baseline in allogrooming time (P = 0.0032) and in redirected behaviors aimed towards the environment (biting and licking time [P = 0.0173]; displacement at the nipple frequency [P = 0.0236]). No negative impact of weaning on growth of either group was identified. Overall, our results tend towards a higher degree of discomfort behaviors (allogrooming, biting/licking, displacement, and vocalizations) in kids weaned earlier compared to later weaning, while kids weaned later showed higher levels of positive behaviors (lying time and self-grooming).

Methods for Biochemical Isolation of Insoluble Tau in Rodent Models of Tauopathies

The intracellular accumulation of microtubule-associated protein tau is a characteristic feature of tauopathies, a group of neurodegenerative diseases including Alzheimer's disease. Formation of insoluble tau aggregates is initiated by the abnormal hyperphosphorylation and oligomerization of tau. Over the past decades, multiple transgenic rodent models mimicking tauopathies have been develop, showcasing this neuropathological hallmark. The biochemical analysis of insoluble tau in these models has served as a valuable tool to understand the progression of tau-related pathology. In this chapter, we provide a comprehensive review of the two primary methods for isolating insoluble tau, namely, sarkosyl and formic acid extraction (and their variants), which are employed for biochemical analysis in transgenic mouse models of tauopathy. We also analyze the strengths and limitations of these methods.

Growth performance, organ weight, and plasma metabolites in broiler chickens fed corn-soybean meal diet containing berry pomaces and fed without or with multienzymes supplement

This study evaluated effects of feeding low-bush wild blueberry (LBP) and organic American cranberry (CRP) pomaces without or with multienzyme supplement (ENZ) on growth performance, organ weight and plasma metabolites in broiler chickens. Nonenzyme-fed (no-ENZ: n = 1,575) and enzyme-fed (ENZ: n = 1,575) day-old male Cobb500 broilers were placed in floor pens (45 chicks/pen) and allocated to five corn-soybean meal-based diets: a basal diet supplemented with either bacitracin methylene disalicylate (BMD, 55 mg/kg), 0.5 or 1% of CRP or LBP in a 2 × 5 factorial design for 35-day experiment. Body weight (BW), feed intake (FI) and mortality were recorded whereas BW gain (BWG) and feed conversion ratio (FCR) were calculated. Birds were sampled at days 21 and 35 for organ weights and plasma metabolites. There were no interactions between diet and ENZ on any parameter (P > 0.05) and no effect of ENZ on overall (d 0-35) growth performance and organ weights (P > 0.05). Birds fed BMD were heavier (P < 0.05) at d 35 and had better overall FCR than berry-supplemented birds. Birds fed 1% LBP had poor FCR than birds fed 0.5% CRP. Birds fed LBP exhibited heavier liver (P < 0.05) than birds fed BMD or 1% CRP. The highest plasma concentrations of aspartate transaminase (AST), creatine kinase (CK) at d 28 and gamma-glutamyl transferase (GGT) at d 35 were found in ENZ-fed birds (P < 0.05). At d 28, birds fed 0.5% LBP showed higher plasma AST and CK concentrations (P < 0.05). However, CRP feeding resulted in a lower plasma CK level compared with BMD feeding (P < 0.05). The lowest cholesterol level was detected in 1% CRP-fed birds. In conclusion, this study showed no ENZ effects to potentiate berry pomaces on the overall growth performance of broilers (P < 0.05. However, plasma profiles revealed the potential of ENZ to modulate the metabolism of pomace-fed broilers. LBP increased BW during the starter phase, while CRP increased BW during the grower phase.

PSXIII-21 Formulations of Vitamin K, Organic Acids, Essential Oils and Plant Hydroalcoholic Extracts Prevent Coccidiosis Impact on Growth Performances in Broilers

The aim of this study was to evaluate the effect of formulations of vitamin K, organic acids, essential oils and plant hydroalcoholic extracts as anticoccidial alternatives in broilers. A 34-day cage trial with 10 replicates of 12 birds/cage was conducted. Male broilers (Ross 308) were randomly assigned to: 1) non-infected (NI); 2) Eimeria-infected (EI); 3) EI+decoquinate/zoalene shuttle program (DZ); 4) EI+2 kg/t Nutri-Gro® feed additive; 5) 3 L/1000 L Technocok® in drinking water from d14 to d20. The formulations were made by Synergie Eurobec International Ltd and contain 7.0 and 7.5 g/kg vitamin K. Eimeria infection was induced by an oral administration at d14 of 2x105 sporulated oocysts of mixed Eimeria species from field isolates. Data were analyzed by a mixed model including treatment and barn section as fixed and random effects, respectively, and by Kruskal-Wallis tests. As expected, the coccidian challenge (EI) reduced growth performances, increased total excreted oocyst counts (6.0 vs 3.0 log10, P &lt; 0.0001) and E. acervulina (0.79 vs 0.21, P=0.0022) and E. tenella (2.04 vs 0.17, P &lt; 0.0001) intestinal lesion scores (ILS) 6 days post infection (dpi, d20), compared to NI, whereas DZ palliated these infection impacts. The two formulation treatments increased d20 body weight (BW), compared to EI (0.980 and 0.939 vs 0.908 kg, P &lt; 0.01), without improving the feed conversion ratio (FCR). The 2 kg/t Nutri-Gro® formulation increased (2.69 vs 2.61 kg, P=0.0486) and the Technocok® showed a trend to improve (2.68 vs 2.61 kg, P=0.1015) d34 BW, compared to EI birds. However, the formulations did not affect the oocyst excretion nor the ILS at 6 dpi (P&gt;0.05). Overall, the additives showed beneficial effects on growth performance in a Eimeria-challenged broilers. These supplements may be involved in a strategy aimed at reducing the use of anticoccidials in broiler production.

PSXIII-B-15 Late Weaning Improves Growth and Reduces the Breeding age in Alpine Dairy Goats

The aim was to evaluate the effect of weaning age on growth in Alpine dairy goats. Thirty-six female kids were randomly assigned to one of 3 treatments: 1) early weaning at 6 wk of age (6-wk), 2) weaning at 8 wk of age (8-wk), and 3) late weaning at 10 wk of age (10-wk). Treatments were blocked by BW and birth date, and each female kid was housed with a male companion of similar age and BW. Kids had ad libitum access to acidified milk replacer (ME=4.7 Mcal/kg DM), kid starter (ME=2.35 Mcal/kg DM), hay (ME=1.26 Mcal/kg DM) and water. Weaning was performed progressively over 7 d. For the 12 wk period, feed intakes for 6-wk, 8-wk and 10-wk were respectively: 135, 201 and 287 g/d for milk replacer; 90, 68, 54 g/d for hay; 25, 19 and 13 g/d for starter feed. Total ME intake was higher when increasing weaning age (6-wk, 281 kcal/d; 8-wk, 303 kcal/d; 10-wk, 371 kcal/d, P&lt; 0.05). Interestingly, at weaning, total ME intake dropped more markedly when weaning was early (6-wk, 95 kcal/d; 8-wk, 297 kcal/d; 10-wk, 451 kcal/d, P&lt; 0.05). 10-wk had higher BW at 12 wk of age (23.9 kg), compared with 6-wk (21.2 kg, P=0.004), and a trend was observed with 8-wk (22.2 kg, P=0.059). This effect of weaning age on BW was prolonged over time with heavier BW in 10-wk at 8 months (36.1 kg), compared to 6-wk (33.6 kg, P=0.04), and a trend was observed with 8-wk (34.0 kg). Using growth curves, extending the weaning age of dairy goats allowed to reach the breeding BW target of 32 kg sooner (6-wk, 191 d; 8-wk, 188 d; 10-wk, 161 d, P&lt; 0.05). Overall, weaning kids at 10 wk limited the negative impact of earlier weaning on growth in the Alpine breed.

Honeybees as a biomonitoring species to assess environmental airborne pollution in different socioeconomic city districts

Honeybees have been used in Europe as environmental bioindicators for heavy metals and polycyclic aromatic hydrocarbons (PAHs). However, their potential has been little explored in North America, especially between environments which have similar pollution levels. Many urban residents and stakeholders are concerned with air quality, mainly in regard to gradients of exposure to industrial pollution between deprived and privileged subpopulation. Thus, the aim of this study was to evaluate the use of honeybees as bioindicators to assess exposure to heavy metals and PAHs in Québec City, Canada, in different socioeconomic districts of Quebec City (deprivation index). Honeybees were sampled over a 5-month period (May to September) at six locations distributed in two urban areas that are distinct geomorphologically and socioeconomically (lower town socio-economically deprived and upper town socioeconomically privileged) and two control rural locations. Six PAHs were analyzed by ultra-performance liquid chromatography (UPLC), while four heavy metals were analyzed by inductively coupled plasma mass spectrometry. Arsenic was the only measured pollutant that showed a significant gradient of exposure between rural and urban environments, but also between the two urban areas. Furthermore, we were able to detect significant differences at certain sampling times for heavy metals and PAHs. Overall, the results show that honeybees are sensitive enough to detect differences between the differential urban environments of a city presumed to have similar pollution levels and therefore could be used when potential socio-environmental inequalities are present.

A survey of dairy goat kid-rearing practices on Canadian farms and their associations with self-reported farm performance

Although future production of dairy goats is influenced by kid-rearing practices, little is known regarding which practices maximize kid growth, welfare, and future production success. The objectives of this survey study were to (1) identify common rearing practices of Canadian commercial dairy goat farms and evaluate their associations with 6 farm performance indicators and (2) determine if farms could be grouped by management style on the basis of the 6 performance indicators and compare rearing practices common across the different groups. A survey was sent by post or electronic media to reach dairy goat producers across Canada. The questionnaire contained 70 questions on the following areas of kid rearing: kidding management, care of newborn, colostrum management, milk and solid feeding in the preweaning period, health management, disbudding, housing conditions, weaning strategies, record keeping and growth monitoring, and farm performance data. Performance indicators, calculated on self-reported data, were 305-d milk production, preweaning mortality rate, diarrhea and respiratory disease prevalence, average daily gain from birth to weaning, herd milk production, and replacement rate. A total of 175 questionnaires were returned. After applying inclusion criteria, including herd size (≥40 goats) and completeness of surveys, 104 respondents from Ontario (n = 72, 69%), Québec (n = 23, 22%), and the Western provinces (n = 9, 9%) were retained for analysis, representing 29% of all Canadian producers. Farm sizes ranged from 42 to 2,500 (median = 190) goats. A large amount of variation in rearing practices and farm performance was found between farms. Colostrum and milk feeding management were found to be associated with all performance indicators except for kid respiratory disease prevalence, with timing of colostrum delivery and feeding method accounting for most the associations within each of the 2 areas. Replacement rate was mostly affected by whether or not kids were reared with their dam. Herds surveyed in the study could successfully be divided into 3 distinct groups (production-focused, longevity-focused, and low performance), representing different management styles on the basis of farm self-reported performance levels. Rearing practices found to be associated with higher farm performance could be targeted by advisory services to help improve management practices on Canadian dairy goat farms.

Effects of Vaccination Against Coccidiosis on Gut Microbiota and Immunity in Broiler Fed Bacitracin and Berry Pomace

Feeding practices have been found to influence gut microbiota which play a major role in immunity of poultry. In the present study, changes in cecal microbiota and humoral responses resulting in the 55 ppm bacitracin (BACI), 1% each of cranberry (CP1) and wild blueberry (BP1) pomace alone or in combination (CP+BP) feeding in broiler Cobb 500 vaccinated or not against coccidiosis were investigated. In the non-vaccinated group, no significant treatment effects were observed on performance parameters. Vaccination significantly affected bird's performance parameters particularly during the growing phase from 10 to 20 days of age. In general, the prevalence of coccidiosis and necrotic enteritis (NE) was reduced by vaccination (P < 0.05). BACI-treated birds showed low intestinal lesion scores, and both CP1 and BP1 feed supplementations reduced Eimeria acervulina and Clostridium perfringens incidences similar to BACI. Vaccination induced change in serum enzymes, minerals, and lipid levels in 21-day old birds while, levels of triglyceride (TRIG) and non-esterified fatty acids (NEFA) were higher (P < 0.05) in CP1 treated non-vaccinated group than in the control. The levels of NEFA were lower in BACI- and CP1-fed birds than in the control in non-vaccinated day 28 old birds. The highest levels of all estimated three immunoglobulins (IgY, IgM, and IgA) were found in the vaccinated birds. Metagenomics analysis of the cecal bacterial community in 21-day old birds showed the presence of Firmicutes (90%), Proteobacteria (5%), Actinobacteria (2%), and Bacteroidetes (2%). In the vaccinated group, an effect of BACI was noted on Proteobacteria (P = 0.03). Vaccination and/or dietary treatments influenced the population of Lactobacillaceae, Enterobacteriaceae, Clostridiaceae, and Streptococcaceae which were among the most abundant families. Overall, this study revealed that besides their beneficial effects on performance, alike bacitracin, berry pomaces in poultry feed have profound impacts on the chicken cecal microbiota and blood metabolites that could be influenced by vaccination against coccidiosis.

Evaluation of neurosurgical training of French military surgeons prior to their deployment

BACKGROUND

A specific training course was formalized in 2007 in order to facilitate the management of cranio-encephalic injuries by French military general surgeons during deployment, within the Advanced Course for Deployment Surgery (ACDS). The objective is to evaluate the neurosurgical pre-deployment training course attended by the military surgeons.

METHODS

From June 2019 to September 2019, we conducted a cross-sectional survey in the form of a digital self-completed questionnaire, addressed to all graduated military surgeons working in the French Military Training Hospitals. The survey included: (1) a knowledge assessment; and (2) a self-assessment of the training course. The participating surgeons were classified into two groups according to their participation (group 1) or not (group 2) in the neurosurgical module. The main outcome was the score received on the knowledge assessment.

RESULTS

Among the 145 military surgeons currently in service, 76 participated in our study (53%), of which 49 were classified in group 1 (64%) and 27 in group 2 (36%). Group 1 surgeons had a significantly higher score than Group 2 at the knowledge assessment (mean 21.0±7.1 vs. 17.8±6.0, P=0.041). The most successful questions were related to TBI diagnosis and surgical technique, while the least successful questions dealt with "beyond emergency care" and surgical indications.

CONCLUSION

The French pre-deployment neurosurgical training course provides a strong neurosurgical background, sufficient to perform life-saving procedures in a modern conflict situation. However, neurosurgical specialized advice should be solicited whenever possible to assist the in-theatre surgeon in surgical decisions.

PSXI-4 Beauveria bassiana to control the mealworm Alphitobius diaperinus in chicken barns

One of the most common insects in poultry houses is the mealworm Alphitobius diaperinus, also known as the darkling beetle. Immature (larvae) and adults feed on seeds spilled on the ground or from poultry droppings. In addition to structural damage, this insect can also be a vector of diseases that can affect birds. In addition, the indigestible shell of the insect can cause digestion problems for birds, and thus affect the profitability of production. It is considered impossible to eliminate the populations of mealworms, and in organic poultry production, the control options are limited. The mycoinsecticide BioCeres WP, based on the fungus Beauveria bassiana, and which controls aphids, has been proposed to control the mealworm A. diaperinus in chicken barns. 450 adult mealworms from a commercial chicken barn were randomly distributed in 9 containers (1 m2) containing 10 cm of wood shavings litter and chicken feed. BioCeres WP was applied by spraying two applications of 40 ml of 10 g/L solution (representing 4 x 10^9 conidia per m2 per application). Mealworms were housed during a broiler batch at the chicken barn they were harvested from and received one of the following treatments: 1) control, water spraying; 2) BioCeres WP treatment. 3 repetitions for control and 6 for BioCeres WP were performed. BioCeres WP increased the mortality rate of mealworms (+101%, P &lt; 0.02; 17.8% vs. 8.6%), compared to untreated mealworms, 28 days after treatment. Mortality rates were affected from day 14 until day 28 after treatment. A trial using 640 broilers in 32 pens revealed no adverse effect on growth performance or health. In summary, BioCeres WP could be involved in a biological strategy to control the mealworm Alphitobius diaperinus in chicken barns.

PSVIII-3 Beneficial effect of cashew nutshell liquid-based supplements in vaccinated broilers against coccidiosis

Vaccination has been developed over the years to counter coccidiosis; however, its effectiveness varies, and it is difficult to exploit due in particular to the young age of chickens at slaughter. Cashew nutsell liquid (CNSL) supplements have shown beneficial effects on growth performance and anticoccidial effects in Eimeria-challenged broilers. However, CNSL effects during an Eimeria infection in vaccinated chickens against coccidiosis need to be determined especially for organic production. Broilers vaccinated against coccidiosis were housed in pens and received one of the following treatments: 1) non-infected, non-treated (blank control); 2) infected, non-treated (negative control); 3) infected, nibarbazin/monensin shuttle program (positive control); 4) infected, Calica+ (CNSL-based formulation). Eimeria infection was induced by an oral administration of 200,000 sporulated oocysts of mixed Eimeria species harvested from field isolates. The trial was performed with 8 pens of 45 birds per treatment. Performance data and oocyst counts were analyzed by a mixed model including treatment as fixed effect and pen as random effect. Intestinal lesion scores were analyzed by category analyses. Calica+ improved average daily gain (ADG) (+7.4%, P &lt; 0.05) and showed a trend to reduce feed conversion ratio (FCR) (−1.8%, P &lt; 0.07) during the overall growing period (days 0–35), compared to infected and untreated broilers. Birds fed Calica+ also showed higher ADG than birds on nibarbazin/monensin shuttle program (+7.2%, P &lt; 0.05). Calica+ did not change levels of oocysts per gram of feces (OPG) at Eimeria excretion peak (6 days after inoculation) but it showed a trend to reduce the Eimeria tenella intestinal lesion scores (p&lt; 0.0685). In summary, the CNSL-based formulation Calica+ showed beneficial growth performance and anticoccidial effects in vaccination conditions against coccidiosis. This organic feed additive could be involved in an anticoccidiosis strategy that includes vaccination.

PSVIII-14 Fifteen months of using litter from recycled manure as bedding for dairy cows: a focus on Klebsiella pneumoniae, Klebsiella variicola and Clostridium perfringens

In recent years, for economical purposes and to improve well-being conditions of cows, several dairy producers have adopted litter made from recycled manure solids (RMS). However, its use raises several safety issues, particularly with respect to mastitis and other infections. We previously observed cases of mastitis caused by K. pneumoniae and K. variicola, and two deadly infections from C. perfringens from cows on RMS. A herd of Holstein cows, distributed in two barns of about 40 lactating cows, was used. RMS was used in one barn, and wood-chip litter (WCL), in the other. RMS was generated by roller presses separation followed by conditioning at 55°C for 24h. Clean and soiled (used) RMS and WCL samples were collected for 15 months. Similarly, material samples before conditioning were also collected, and all samples were analyzed by viability-qPCR. Milk samples from cows with mastitis and somatic cell count data (SCC) were analyzed. Total and living contents of K. pneumoniae, K. variicola, C. perfringens and Klebsiella spp. were higher in the RMS than the WCL (+1.6–4.2 log10, P &lt; 0.05). Composting 24h at 55°C did not affect total and live levels of C. perfringens, K. pneumoniae, and even increased total and live levels of K. variicola (+0.9 log10, P &lt; 0.05). A seasonal effect or the number of cycles recycling the RMS decreased levels of K. pneumoniae in winter. Overall, RMS had no significant effect on SCC, but increased mastitis incidence (+39%, P &lt; 0.05), compared to WCL. Milk analysis revealed that higher levels of K. pneumoniae found in RMS could contribute to the increase in mastitis cases caused by this pathogen. Data reported from this study are not favorable to the use of an RMS conditioned for 24h at 55°C with dairy cows, apropos the microbiological aspect; however, these results must be confirmed by other studies.

162 Raising your kids the right way: A survey of rearing practices in Canadian dairy goat farms

Kid rearing is the foundation of goat milk production, yet little is known about how to raise replacement does efficiently to make healthy and productive dairy animals. This study aimed to identify the common rearing practices of Canadian commercial dairy goat farms (≥40 goats/farm), from birth to weaning, and to determine best management practices to improve herd performances. A survey was sent to dairy goat producers across Canada by post or email, and 104 respondents were selected for analysis. The 70-questions survey collected information regarding kidding management, care of the newborn, feeding in the preweaning period, housing, weaning and herd performances. Respondents were from Ontario (69%), Quebec (22%) and the Western provinces (9%). Farm sizes ranged from 42 to 2,500 (median: 190) goats, and most producers (64%) were relatively new to goat milk production (≤10 yrs). A large amount of variation in rearing practices was seen across farms. Ad libitum milk was offered on 55% of farms, and there was no consistency as to when concentrates, forages and water were first offered to kids. Weaning criteria was predominantly a mix of age and weight of the kid (36%), followed by age only (27%) and weight only (22%). Weaning age varied between 4.5 and 20 (median: 8) wks and weaning weight varied between 9 and 35 (median: 15) kg. Weaning methods ranged from abrupt (37%) to different progressive strategies (20% skipping milk feedings, 19% reducing milk quantity, and 10% diluting milk with water). This research provides the dairy goat industry with information concerning current common kid rearing practices used on Canadian goat farms, and the lack of consensus indicates that further research is necessary to determine and refine the best kid rearing practices for Canadian farms.

PSVI-17 The organic feed additive Calica+ improves growth performance and shows anticoccidial effects in broilers

Development of natural alternatives to drugs is necessary for the poultry industry not only for organic production, but also for limiting drug resistance and for complying with upcoming regulations. Two pen trials were conducted to evaluate the effect of Calica+, an activated vegetal oil from cashew nut shell liquid (CNSL), on broiler performance and on coccidiosis in different conditions. The first trial was conducted in Eimeria vaccination conditions with commercial Coccivac-B52. The second one was realized in Eimeria challenge conditions, induced by an oral administration of 200,000 sporulated oocysts of mixed Eimeria species harvested from field isolates. In Eimeria vaccination conditions trial, Calica+ improved average daily gain (ADG) (+4.5%, P &lt; 0.05) during the overall growing period and decreased levels of oocysts per gram of feces (OPG) (−44.1%, P &lt; 0.05), at Eimeria excretion peak (days 17–20), compared to untreated broilers. However, no significant effect of Calica+ on Eimeria intestinal lesions was observed. Overall ADG in Calica+-treated birds was not significantly different compared to nicarbazin-monensin anticoccidial medication (P = 0.8362) but showed higher feed conversion ratio (FCR; +6.0%, P &lt; 0.05). In Eimeria challenge conditions trial, Calica+ feeding treatment improved ADG after infection, during the period from d20 to d36 of age (+4.4%, P &lt; 0.05) compared to untreated birds. Compared with nicarbazin-monensin medication, Calica+-treated birds showed higher FCR (+3.5%, P &lt; 0.05), but comparable ADG (P = 0.3145). Interestingly, birds fed the treatment with Calica+ showed a trend of increased plasmatic levels of IL-1ß compared to untreated broilers (+25.6%, P = 0.0676), suggesting an immune activation as a potential mechanism of action for Calica+. In summary, Calica+ showed beneficial growth performance and anticoccidial effects in these two different trial conditions. This feed additive could be involved in a strategy to reduce the use of anticoccidial medication in broiler production.

Hyperketolactia occurrence before or after artificial insemination is associated with a decreased pregnancy per artificial insemination in dairy cows

The reproductive parameters of dairy cattle have continuously declined worldwide over the last 50 years. Nutritional imbalances are identified as risk factors for this decrease of reproductive performance. The present paper aims to quantify the decrease in the pregnancy per artificial insemination (P/AI) in the case of high milk ketones before and after AI. A total of 388,731 test-day from the Brittany Milk Recording Program in France from 226,429 cow-lactations were provided for this trial. For each test-day, information about lactation characteristics, date of AI, date of the following calving, and acetone and β-hydroxybutyrate (BHB) values were included. Ketones were predicted by Fourier transform mid-infrared spectroscopy using MilkoScan Foss analyzers (Foss, Hillerød, Denmark). Many thresholds were evaluated to define cows with hyperketolactia. Hyperketolactia statuses were then categorized into 1 of 4 possible classes according to the milk ketone dynamics for each AI and each threshold of acetone or BHB values (low-low, high-low, low-high, and high-high) within 20 d before and after AI. Similarly, the dynamics of udder health were characterized by changes in somatic cell counts measured at the same test day as ketone bodies. A logistic regression with a Poisson correction was performed to explain the relationship of P/AI with milk ketones and somatic cell count dynamics. Predicted acetone and BHB ranged from -0.51 to 4.92 mM (mean = 0.08 mM, SD = 0.10 mM) and -0.62 to 5.85 mM (mean = 0.07 mM, SD = 0.1 mM), respectively. Hyperketolactia defined by high acetone levels before AI was not associated with decreased P/AI, but high acetone levels after AI were associated with a >10% reduction in P/AI for all thresholds >0.10 mM. Hyperketolactia, defined by high BHB values before, after, or before and after AI, was associated with a 6 to 14% reduction in P/AI compared with cows with low BHB values. These associations are lower than those reported in previous trials in which blood ketones were used. High ketones in advanced lactation are likely to be the result of various primary disorders (secondary ketosis). Because the present work demonstrated that this situation is considered a risk factor for deteriorated reproductive performance, we suggest that high ketones in early and advanced lactation should be of interest to farm advisors.

In vivo induction of membrane damage by β-amyloid peptide oligomers

Exposure to the β-amyloid peptide (Aβ) is toxic to neurons and other cell types, but the mechanism(s) involved are still unresolved. Synthetic Aβ oligomers can induce ion-permeable pores in synthetic membranes, but whether this ability to damage membranes plays a role in the ability of Aβ oligomers to induce tau hyperphosphorylation, or other disease-relevant pathological changes, is unclear. To examine the cellular responses to Aβ exposure independent of possible receptor interactions, we have developed an in vivo C. elegans model that allows us to visualize these cellular responses in living animals. We find that feeding C. elegans E. coli expressing human Aβ induces a membrane repair response similar to that induced by exposure to the CRY5B, a known pore-forming toxin produced by B. thuringensis. This repair response does not occur when C. elegans is exposed to an Aβ Gly37Leu variant, which we have previously shown to be incapable of inducing tau phosphorylation in hippocampal neurons. The repair response is also blocked by loss of calpain function, and is altered by loss-of-function mutations in the C. elegans orthologs of BIN1 and PICALM, well-established risk genes for late onset Alzheimer's disease. To investigate the role of membrane repair on tau phosphorylation directly, we exposed hippocampal neurons to streptolysin O (SLO), a pore-forming toxin that induces a well-characterized membrane repair response. We find that SLO induces tau hyperphosphorylation, which is blocked by calpain inhibition. Finally, we use a novel biarsenical dye-tagging approach to show that the Gly37Leu substitution interferes with Aβ multimerization and thus the formation of potentially pore-forming oligomers. We propose that Aβ-induced tau hyperphosphorylation may be a downstream consequence of induction of a membrane repair process.

[Result of treatment of urinary lithiasis for professional aptitude]

INTRODUCTION

Military people are inapt for presence of urinary stones. In this specific population, the treatment of stones is even more aggressive than for the general population without recommendation. The final decision about aptitude is the responsibility of the military doctor. Whereas, ureteroscopy has its place there and must done by any urologist.

METHODS

The purpose of this study was to estimate the results of treatments by ureteroscopy in this population. Success was defined by the complete absence of fragment visualized in the imaging of control operating comment and so the end of the inaptitude time.

RESULTS

Between 2009 and 2016, forty-two were treated for ureteral or renal calculi. The population comprises of 93% men, 35 years old on average. The stones were mainly multiple (more 2) and the medium size is 5mm; sixteen (42.9%) was at the left and eight (19%) was bilateral. In 78.8% (78) of the cases there was a stone in renal position whose 50% (39) still at the lower calyx. In total, 5% of the patients were stone-free in 2 sessions on average. The average deadline of inaptitude of the initial consultation in the resumption of work was of 6 months. In 4% of the cases there was a complication operating rank 4.

CONCLUSION

This study confirms the feasibility, the weak harmlessness of ureteroscopy and the lesser deadline of inaptitude. Every urologist can treat this specific population. The patient must be informed and accept the treatment because of excluding referential.

LEVEL OF EVIDENCE

4.

Redox potential: An intrinsic parameter of the rumen environment

The ruminal ecosystem is a fermentative milieu which is interesting to discuss in terms of its redox status as a reflection of an intense bacterial activity. The objective of this systematic literature review is to quantitatively analyze data collected on redox potential (Eh) in the rumen and to explore relationship between ruminal Eh, nature of the diet fed to ruminants, and ruminal fermentation parameters. Data obtained from 15 studies comprising 24 different diets was used in the analysis. Studies included in the data file were selected based on the criteria of: (i) the nature of the reference electrode was specified, (ii) the ruminal Eh was recorded simultaneously to pH, (iii) animal body weight (BW) and dry matter intake (DMI) were reported and (iv) the composition of the diet was precisely described. Results showed a high variability in ruminal Eh values. However, all recorded values are markedly negative reflecting the absence of oxygen and the strong reducing power of the rumen environment. The main factors contributing to the variation were the method of Eh measurement and the nature of the diet fed to ruminants. Redox potential was positively correlated with DMI and proportion of concentrate in the diet, and tended to be positively correlated with soluble carbohydrates content. In contrast, it was negatively correlated with neutral detergent fibre from forages. The hierarchical ascendant classification discriminated two groups of diets leading to significant change in ruminal Eh level. Ruminal Eh was negatively correlated with pH, total volatile fatty acids produced and proportion of acetate, and positively correlated with proportion of propionate. This review revealed Eh to be dependent on the diet composition and DMI, at least within the range of diets included in the database.

Atrial fibrillation is associated with hypermethylation in human left atrium, and treatment with decitabine reduces atrial tachyarrhythmias in spontaneously hypertensive rats

Atrial fibrillation (AF) is the most common cardiac arrhythmia. As the molecular mechanisms underlying the pathology are largely unknown, this cardiac arrhythmia remains difficult to treat. To identify specific molecular actors involved in AF, we have performed a transcriptomic analysis on left atrium (LA) from patients with valvular heart disease with or without AF. We showed that 1627 genes had altered basal expression level in LA tissue of AF patients compared with the control group. The significantly enriched gene ontology biological process "anatomical structure morphogenesis" contained the highest number of genes in line with changes in structure that occur when the human heart remodels following AF development (ie, LA dilatation and interstitial fibrosis). We then focused the study on Pitx2 (paired-like homeodomain 2), being the most altered transcription factor in LA from AF patients and from which compelling evidence have indicated that its reduced expression can be considered as a marker for the disease. In addition, its expression was inversely correlated with LA size. We demonstrated that AF is associated with Pitx2 promoter hypermethylation both in humans and arrhythmic aging spontaneously hypertensive rats. Chronic administration of a DNA methylation inhibitor (ie, 5-Aza-2'-deoxycitidine) improved ECG arrhythmic profiles and superoxide dismutase activities and reduced fibrosis in the left ventricle of spontaneously hypertensive rats. Taken together, these data support the notion that AF is associated with epigenetic changes in LA and provide a proof-of-concept that hypomethylating agents have to be considered in the treatment of atrial arrhythmias.

Conserved pharmacological rescue of hereditary spastic paraplegia-related phenotypes across model organisms

Hereditary spastic paraplegias (HSPs) are a group of neurodegenerative diseases causing progressive gait dysfunction. Over 50 genes have now been associated with HSP. Despite the recent explosion in genetic knowledge, HSP remains without pharmacological treatment. Loss-of-function mutation of the SPAST gene, also known as SPG4, is the most common cause of HSP in patients. SPAST is conserved across animal species and regulates microtubule dynamics. Recent studies have shown that it also modulates endoplasmic reticulum (ER) stress. Here, utilizing null SPAST homologues in C. elegans, Drosophila and zebrafish, we tested FDA-approved compounds known to modulate ER stress in order to ameliorate locomotor phenotypes associated with HSP. We found that locomotor defects found in all of our spastin models could be partially rescued by phenazine, methylene blue, N-acetyl-cysteine, guanabenz and salubrinal. In addition, we show that established biomarkers of ER stress levels correlated with improved locomotor activity upon treatment across model organisms. Our results provide insights into biomarkers and novel therapeutic avenues for HSP.

Investigation on the iron-uptake by natural biofilms

Biofilms are natural communities of microorganisms living in aquatic ecosystems which play an important role in the biogeochemistry of many inorganic elements, including iron. The present work aimed to study the uptake of iron by natural river biofilms (produced in the laboratory) and to examine the relationships between biofilms and iron in water. For that, biofilms were formed from natural water samples collected at different times of the year. Total content and global localization of iron were determined by a combination of chemical analyses and microscopy, which indicated that iron was systematically distributed throughout the biofilm matrix. Depending on the level of iron uptake, iron was diffuse or present as hot spots, was primarily localized to the fraction ascribed to OM compounds (45-60%) or the residual fraction (∼14-40%). Additional experiments were conducted using iron-organic complexes with different affinities (log K) to study iron uptake according to the speciation. These experiments suggested the association between iron and organic ligands (i.e. depending on the affinity constant) influenced the uptake of iron, but did not control the biofilm affinity for iron, which appeared to be controlled by chemical-kinetic laws.

Pharmacological reduction of ER stress protects against TDP-43 neuronal toxicity in vivo

C. elegans and D. rerio expressing mutant TAR DNA Binding Protein 43 (TDP-43) are powerful in vivo animal models for the genetics and pharmacology of amyotrophic lateral sclerosis (ALS). Using these small-animal models of ALS, we previously identified methylene blue (MB) as a potent suppressor of TDP-43 toxicity. Consequently here we investigated how MB might exert its neuroprotective properties and found that it acts through reduction of the endoplasmic reticulum (ER) stress response. We tested other compounds known to be active in the ER unfolded protein response in worms and zebrafish expressing mutant human TDP-43 (mTDP-43). We identified three compounds: salubrinal, guanabenz and a new structurally related compound phenazine, which also reduced paralysis, neurodegeneration and oxidative stress in our mTDP-43 models. Using C. elegans genetics, we showed that all four compounds act as potent suppressors of mTDP-43 toxicity through reduction of the ER stress response. Interestingly, these compounds operate through different branches of the ER unfolded protein pathway to achieve a common neuroprotective action. Our results indicate that protein-folding homeostasis in the ER is an important target for therapeutic development in ALS and other TDP-43-related neurodegenerative diseases.

Effects of increasing amounts of corn dried distillers grains with solubles in dairy cow diets on methane production, ruminal fermentation, digestion, N balance, and milk production

The objective of this study was to examine the effects of including corn dried distillers grains with solubles (DDGS) in the diet at the expense of corn and soybean meal on enteric CH4 emissions, ruminal fermentation characteristics, digestion (in sacco and apparent total-tract digestibility), N balance, and milk production of dairy cows. Twelve lactating Holstein cows were used in a triplicated 4×4 Latin square design (35-d periods) and fed (ad libitum intake) a total mixed ration containing (dry matter basis) 0, 10, 20, or 30% DDGS. Dry matter intake increased linearly, whereas apparent-total tract digestibility of dry matter and gross energy declined linearly as DDGS level in the diet increased. Increasing the proportion of DDGS in the diet decreased the acetate:propionate ratio, but this decrease was the result of reduced acetate concentration rather than increased propionate concentration. Milk yield increased linearly (up to +4kg/d) with increasing levels of DDGS in the diet and a tendency was observed for a quadratic increase in energy-corrected milk as the proportion of DDGS in the diet increased. Methane production decreased linearly with increasing levels of DDGS in the diet (495, 490, 477, and 475 g/d for 0, 10, 20, and 30% DDGS diets, respectively). When adjusted for gross energy intake, CH4 losses also decreased linearly as DDGS proportion increased in the diet by 5, 8, and 14% for 10, 20, and 30% DDGS diets, respectively. Similar decreases (up to 12% at 30% DDGS) were also observed when CH4 production was corrected for digestible energy intake. When expressed relative to energy-corrected milk, CH4 production declined linearly as the amount of DDGS increased in the diet. Total N excretion (urinary and fecal; g/d) increased as the amount of DDGS in the diet increased. Efficiency of N utilization (milk N secretion as a proportion of N intake) declined linearly with increasing inclusion of DDGS in the diet. However, productive N increased linearly with increasing proportions of DDGS in the diet, suggesting better efficiency of N use by the animal. Results from this study show that feeding DDGS to dairy cows can help to mitigate enteric CH4 emissions without negatively affecting intake and milk production.

Deregulation of protein phosphatase 2A and hyperphosphorylation of τ protein following onset of diabetes in NOD mice

The histopathological hallmarks of Alzheimer disease (AD) include intraneuronal neurofibrillary tangles composed of abnormally hyperphosphorylated τ protein. Insulin dysfunction might influence AD pathology, as population-based and cohort studies have detected higher AD incidence rates in diabetic patients. But how diabetes affects τ pathology is not fully understood. In this study, we investigated the impact of insulin dysfunction on τ phosphorylation in a genetic model of spontaneous type 1 diabetes: the nonobese diabetic (NOD) mouse. Brains of young and adult female NOD mice were examined, but young NOD mice did not display τ hyperphosphorylation. τ phosphorylation at τ-1 and pS422 epitopes was slightly increased in nondiabetic adult NOD mice. At the onset of diabetes, τ was hyperphosphorylated at the τ-1, AT8, CP13, pS262, and pS422. A subpopulation of diabetic NOD mice became hypothermic, and τ hyperphosphorylation further extended to paired helical filament-1 and TG3 epitopes. Furthermore, elevated τ phosphorylation correlated with an inhibition of protein phosphatase 2A (PP2A) activity. Our data indicate that insulin dysfunction in NOD mice leads to AD-like τ hyperphosphorylation in the brain, with molecular mechanisms likely involving a deregulation of PP2A. This model may be a useful tool to address further mechanistic association between insulin dysfunction and AD pathology.

Left atrial endocardial fibrosis and intra-atrial thrombosis - landmarks of left atrial remodeling in rats with spontaneous atrial tachyarrhythmias

INTRODUCTION

Histological abnormalities are common findings in the left atria (LA) of atrial fibrillation (AF) patients. We aimed to assess LA histological abnormalities in our model of spontaneous atrial tachyarrhythmias in rats.

MATERIALS AND METHODS

LA sampling was performed in 12 spontaneously hypertensive rats (SHRs) and eight age-matched Wistar-Kyoto (WKY) rats. Tissue sections were stained with Masson's trichrome and Hematoxylin-Eosin-Safran and examined with a light microscope. A 0 to 3 scoring system was used to quantify the severity of LA structural abnormalities. LA von Willebrand factor (vWF) content was also assessed using immunohistochemical staining.

RESULTS

In six of the eight SHRs, LA fibrosis, inflammatory infiltrates, and myocyte necrosis of varying grades of severity were observed. The most frequent feature was endocardial fibrosis, which was observed in six SHRs and in none of the WKY rats. Intra-atrial thrombosis was found in three SHRs and in none of the WKY rats. The intensity of vWF-related fluorescence was higher in the atrial endocardium of SHRs compared to age-matched WKY rats.

CONCLUSIONS

Our findings reinforce the role of LA structural abnormalities in atrial arrhythmogenicity. However, two SHRs did not present LA histological abnormalities despite the presence of arrhythmias. This finding suggests that the LA remodeling-atrial tachyarrhythmia relationship could be highly nonlinear and that atrial fibrosis is more likely to be a facilitator of atrial arrhythmogenicity, rather than a prerequisite. We also provide evidence that intra-atrial thrombosis accompanies LA structural remodeling in arrhythmic rats. Increased endocardial platelet adhesion molecule vWF could contribute to this increased thrombogenicity.

Sex-dependent alterations in social behaviour and cortical synaptic activity coincide at different ages in a model of Alzheimer's disease

Besides memory deficits, Alzheimer's disease (AD) patients suffer from neuropsychiatric symptoms, including alterations in social interactions, which are subject of a growing number of investigations in transgenic models of AD. Yet the biological mechanisms underlying these behavioural alterations are poorly understood. Here, a social interaction paradigm was used to assess social dysfunction in the triple-transgenic mouse model of AD (3xTg-AD). We observed that transgenic mice displayed dimorphic behavioural abnormalities at different ages. Social disinhibition was observed in 18 months old 3xTg-AD males compared to age and sex-matched control mice. In 3xTg-AD females, social disinhibition was present at 12 months followed by reduced social interactions at 18 months. These dimorphic behavioural alterations were not associated with alterations in AD neuropathological markers such as Aβ or tau levels in the frontal cortex. However, patch-clamp recordings revealed that enhanced social interactions coincided temporally with an increase in both excitatory and inhibitory basal synaptic inputs to layer 2-3 pyramidal neurons in the prefrontal cortex. These findings uncover a novel pattern of occurrence of psychiatric-like symptoms between sexes in an AD model. Our results also reveal that functional alterations in synapse activity appear as a potentially significant substrate underlying behavioural correlates of AD.

Cognitive and non-cognitive behaviors in the triple transgenic mouse model of Alzheimer's disease expressing mutated APP, PS1, and Mapt (3xTg-AD)

3xTg-AD mutant mice are characterized by parenchymal Aβ plaques and neurofibrillary tangles resembling those found in patients with Alzheimer's disease. The mutants were compared with non-transgenic controls in sensorimotor and learning tests. 3xTg-AD mutants were deficient in T-maze reversal, object recognition, and passive avoidance learning. In addition, the mutants showed hypoactivity in two open-field tests, fewer fecal boli in an observation jar, and reduced enclosed arm entries and head-dipping in the elevated plus-maze. On the contrary, the mutants did not differ from controls in pain thresholds, nest-building, and various reflexes determined by the SHIRPA primary screen and were even better on the rotorod test of motor coordination.

Dimethyl sulfoxide induces both direct and indirect tau hyperphosphorylation

Dimethyl sulfoxide (DMSO) is widely used as a solvent or vehicle for biological studies, and for treatment of specific disorders, including traumatic brain injury and several forms of amyloidosis. As Alzheimer’s disease (AD) brains are characterized by deposits of β-amyloid peptides, it has been suggested that DMSO could be used as a treatment for this devastating disease. AD brains are also characterized by aggregates of hyperphosphorylated tau protein, but the effect of DMSO on tau phosphorylation is unknown. We thus investigated the impact of DMSO on tau phosphorylation in vitro and in vivo. One hour following intraperitoneal administration of 1 or 2 ml/kg DMSO in mice, no change was observed in tau phosphorylation. However, at 4 ml/kg, tau was hyperphosphorylated at AT8 (Ser²⁰²/Thr²⁰⁵), PHF-1 (Ser³⁹⁶/Ser⁴⁰⁴) and AT180 (Thr²³¹) epitopes. At this dose, we also noticed that the animals were hypothermic. When the mice were maintained normothermic, the effect of 4 ml/kg DMSO on tau hyperphosphorylation was prevented. On the other hand, in SH-SY5Y cells, 0.1% DMSO induced tau hyperphosphorylation at AT8 and AT180 phosphoepitopes in normothermic conditions. Globally, these findings demonstrate that DMSO can induce tau hyperphosphorylation indirectly via hypothermia in vivo, and directly in vitro. These data should caution researchers working with DMSO as it can induce artifactual results both in vivo and in vitro.

[A new, spontaneous method for assessing sympathetic baroreflex function in humans]

In humans, assessment of the sympathetic component of the arterial baroreceptor reflex (sBRS) is usually based on microneurographic recordings of muscle sympathetic nerve activity (MSNA), while inducing reflex changes with intravenous administration of vasoactive drugs (modified Oxford method). This method has several limitations, among which its poor temporal resolution. Some studies have proposed alternative methods by using spontaneous changes in arterial pressure (AP) and MSNA, usually collected under baroreflex closed-loop conditions (AP alters MSNA while MSNA alters AP), which makes the results difficult to interpret. In rats, a method has been developed and validated (Kanbar et al., 2007 [1]), which uses oscillations of renal SNA at the frequency of the heart beat. At this frequency, the baroreflex operates under open-loop conditions because of the low-pass filter properties of the resistance vasculature. The goal of the present study was to examine whether this method is applicable in humans. Data were previously collected by Gujic et al. (2007) [2]. Briefly, MSNA and AP were recorded in 16 young healthy subjects during a 5-minute baseline resting period then during a modified Oxford test (sodium nitroprusside and phenylephrine administrations). Using the 5-minute baseline recordings, spontaneous sBRS was assessed through empirical mode decomposition over consecutive 20-second periods. Spontaneous sBRS was significantly related to pharmacological sBRS (R=0.67, n=16, P=0.004). During the 5-minute period, spontaneous sBRS exhibited variations (CV=21.7±1.7%) that were negatively correlated with AP in five subjects (R=-0.61±0.03, P<0.05) and positively correlated with MSNA in ten subjects (R=0.73±0.03, P<0.05). The new method is able to correctly estimate sBRS, and reveals the existence of previously unrecognized fast fluctuations of sBRS.

Dietary intake of unsaturated fatty acids modulates physiological properties of entorhinal cortex neurons in mice

Dietary lipids modify brain fatty acid profile, but evidence of their direct effect on neuronal function is sparse. The enthorinal cortex (EC) neurons connecting to the hippocampus play a critical role in learning and memory. Here, we have exposed mice to diets based on canola:soybean oils (40 : 10, g/kg) or safflower : corn oils (25 : 25, g/kg) to investigate the relationship between the lipid profile of brain fatty acids and the intrinsic properties of EC neurons. Consumption of canola : soybean oil-enriched diet led to the increase of the monounsaturated fatty acid oleic acid and to a decrease of arachidonic acid in ethanolamine glycerophospholipids of the white matter. We also found an important rise in docosahexaenoic acid (DHA) within ethanolamine glycerophospholipids and phosphatidylserine of gray matter. The canola:soybean oil treatment led to a shorter duration of action potential (-21%), a reduction in the duration of postsynaptic response (-21%) and increased firing activity (+43%). Data from additional experiments with animals fed DHA alone or DHA with canola oil suggested that dietary monounsaturated fatty acid may have contributed to these effects on EC neuron physiology. Since neuronal function within the enthorhinal-hippocampal loop is critical to learning and memory processes, the present data may provide a functional basis for the beneficial cognitive effects of canola oil-based diets.

Biochemical isolation of insoluble tau in transgenic mouse models of tauopathies

Tau is a highly soluble microtubule-associated protein (MAP) that is abundant in the central nervous system and expressed mainly in neuronal axons. Intracellular aggregates of insoluble tau protein are present in a group of neurodegenerative diseases called tauopathies, which include Alzheimer's disease. Numerous transgenic mouse models of tauopathies have been produced in the last decade, and analysis of insoluble tau in these animals has provided a powerful tool to understand the development of tau pathology. In this short chapter, we aim at reviewing the two main isolation methods, sarkosyl and formic acid extraction (and their variations), used for the biochemical isolation of insoluble tau in transgenic mouse models of tauopathy, and discuss their advantages and drawbacks.

Accumulation of dietary docosahexaenoic acid in the brain attenuates acute immune response and development of postischemic neuronal damage

BACKGROUND AND PURPOSE

Consumption of fish has been shown to reduce risk of coronary heart disease and, possibly, of ischemic stroke. Because docosahexaenoic acid (DHA) is the most likely neuroactive component within fish oil, we hypothesized that exposing mice to a DHA-enriched diet may reduce inflammation and protect neurons against ischemic injury.

METHODS

To visualize the effects of DHA on neuroinflammation after stroke, TLR2-fluc-GFP transgenic mice were exposed to either a control diet, a diet depleted in n-3 polyunsaturated fatty acid, or a diet enriched in DHA during 3 months. Real-time biophotonic/bioluminescence imaging of the TLR2 response was performed before and after middle cerebral artery occlusion, whereas cytokines concentrations and stroke area analyses were performed at 3 and 7 days after middle cerebral artery occlusion, respectively.

RESULTS

We show that a 3-month DHA treatment prevented microglial activation after ischemic injury, reduced the ischemic lesion size, and increased levels of the antiapoptotic molecule Bcl-2 in the brain. Additional analysis revealed a significant decrease in the levels of COX2 and IL-1β, but not in other proinflammatory cytokines. Importantly, long-term DHA supplementation significantly changed the n-3:n-6 polyunsaturated fatty acid ratio in the brain.

CONCLUSIONS

Collectively, these data indicate that diet-induced accumulation of DHA in the brain protects against postischemic inflammation and injury. Because DHA is widely available at low cost and has an excellent safety profile, our data suggest that increased DHA intake may provide protection against acute immune response/brain damage in ischemic stroke.

Is the Rigid-Band Model Applicable in Lithium Intercalation Compounds?

Numerous layered compounds are interesting materials in which lithium intercalation occurs primarily without destruction of the host lattice. In many cases a rigid-band model is a useful first approximation for describing the changes in electronic properties of the host material with intercalation. This paper presents some recent experimental results obtained on transition-metal chalcogenide compounds and on transition-metal oxides as well. We shall observe, nevertheless, that the rigid-band model is not applicable to all of the intercalated materials. The applicability of the rigid-band model may be used as a test for the most desirable properties of a good intercalation material. This needs to be more extensively documented for their possible applications as insertion electrodes in solid state batteries.

Optical Spectroscopies of Lithium-Intercalated Compounds

Layered compounds are known to form lithium intercalation complexes as electron donor systems. A charge transfer which can strongly affect the electronic properties of the host lattice, and a change of preferential crystallographic parameters without destruction of the original structure are the main effects occuring during intercalation. Optical spectroscopies such as Raman scattering, far-infrared reflectivity, absorption measurements and photoluminescence have been carried out for the study of electronic and structural modifications. Upon lithium intercalation, lattice dynamics and electronic band structure change in numerous layered compounds. The optical properties of transition-metal dichalcogenides, non-transition metal chalcogenides and transition-metal oxides are presented and discussed with the aim of a better understanding of the intercalation process and establish some guide lines for improving the performances of these materials in their most important applications.