Feeding predictability as a cognitive enrichment protects brain function and physiological status in rainbow trout: a multidisciplinary approach to assess fish welfare.

Cognitive enrichment is a promising but understudied type of environmental enrichment that aims to stimulate the cognitive abilities of animals by providing them with more opportunities to interact with (namely, to predict events than can occur) and to control their environment. In a previous study, we highlighted that farmed rainbow trout can predict daily feedings after two weeks of conditioning, the highest conditioned response being elicited by the combination of both temporal and signalled predictability. In the present study, we tested the feeding predictability that elicited the highest conditioned response in rainbow trout (both temporal and signalled by bubbles, BUBBLE + TIME treatment) as a cognitive enrichment strategy to improve their welfare. We thus analysed the long-term effects of this feeding predictability condition as compared with an unpredictable feeding condition (RANDOM treatment) on the welfare of rainbow trout, including the markers in the modulation of brain function, through a multidisciplinary approach. To reveal the brain regulatory pathways and networks involved in the long-term effects of feeding predictability, we measured gene markers of cerebral activity and plasticity, neurotransmitter pathways and physiological status of fish (oxidative stress, inflammatory status, cell type and stress status). After almost three months under these predictability conditions of feeding, we found clear evidence of improved welfare in fish from BUBBLE + TIME treatment. Feeding predictability allowed for a food anticipatory activity and resulted in fewer aggressive behaviours, burst of accelerations, and jumps before mealtime. BUBBLE + TIME fish were also less active between meals, which is in line with the observed decreased expression of transcripts related to the dopaminergic system. BUBBLE + TIME fish tented to present fewer eroded dorsal fin and infections to the pathogen Flavobacterium psychrophilum. Decreased expression of most of the studied mRNA involved in oxidative stress and immune responses confirm these tendencies else suggesting a strong role of feeding predictability on fish health status and that RANDOM fish may have undergone chronic stress. Fish emotional reactivity while isolated in a novel-tank as measured by fear behaviour and plasma cortisol levels were similar between the two treatments, as well as fish weight and size. To conclude, signalled combined with temporal predictability of feeding appears to be a promising approach of cognitive enrichment to protect brain function via the physiological status of farmed rainbow trout in the long term.

["Post traumatic" leptospirosis complicated by acute respiratory insufficiency]. / Leptospirose ictéro-hémorragique << post traumatique >> compliquée d'insuffisance respiratoire aiguë

INTRODUCTION: Leptospirosis is a rare cause of alveolar haemorrhage. The diagnosis is often delayed particularly when the mode of infection is atypical. These serious complications require prompt antibiotic treatment. CASE REPORT: A 21-year-old man was involved in a road accident and found lying unconscious in a roadside ditch containing stagnant water. Ten days later he presented with bilateral interstitial pneumonia and rapidly increasing hypoxaemia associated with cholestasis and liver cell necrosis. Broncho-alveolar lavage revealed alveolar haemorrhage. There was satisfactory resolution following antibiotic therapy. CONCLUSIONS: The diagnosis of leptospirosis was considered initially despite negative serology (Martin and Petit) and confirmed by sero-conversion 20 days after the onset of symptoms.

[Pulmonary embolism. Risk factors of venous thromboembolic disease]. / Embolie pulmonaire. Facteurs de risque de la maladie thrombo-embolique veineuse.

RISK FACTORS: Management of deep venous thromboembolism both in terms of diagnosis and therapeutic and prophylactic strategies has been greatly improved by advances in knowledge of the main acquired and intrinsic risk factors. RESISTANCE TO ACTIVATED PROTEIN C: This is by far the most frequent coagulation disorder predisposing to venous thromboembolism. Other intrinsic factors favoring thrombus formation (anti-thrombin II, protein C or protein S deficiencies) are much more uncommon. Laboratory tests in search for these anomalies are indicated essentially for patients who develop repeated episodes of venous thrombus formation. PROPHYLAXIS: Excepting specific cases, anticoagulant prophylaxis is not indicated in any of these anomalies beyond the usual treatment of a first episode. Among the risk factors for acquired deep vein thromboembolism, only surgery and certain obstetrical indications have been investigated sufficiently to define validated prophylaxis strategies. For medical risks, the benefit of anticoagulant prophylaxis has been demonstrated in certain disease states such as cancer, antiphospholipid syndrome and the acute phase of myocardial infarction although no widely accepted strategy has yet been established.