Estrogen receptor-α signaling in tanycytes lies at the crossroads of fertility and metabolism.

Background: Estrogen secretion by the ovaries regulates the hypothalamic-pituitary-gonadal axis during the reproductive cycle, influencing gonadotropin-releasing hormone (GnRH) and luteinizing hormone (LH) secretion, and also plays a role in regulating metabolism. Here, we establish that hypothalamic tanycytes-specialized glia lining the floor and walls of the third ventricle-integrate estrogenic feedback signals from the gonads and couple reproduction with metabolism by relaying this information to orexigenic neuropeptide Y (NPY) neurons.

Methods: Using mouse models, including mice floxed for Esr1 (encoding estrogen receptor alpha, ERα) and those with Cre-dependent expression of designer receptors exclusively activated by designer drugs (DREADDs), along with viral-mediated, pharmacological and indirect calorimetric approaches, we evaluated the role of tanycytes and tanycytic estrogen signaling in pulsatile LH secretion, cFos expression in NPY neurons, estrous cyclicity, body-weight changes and metabolic parameters in adult females.

Bacterial microbiota and proinflammatory cytokines in the anal sacs of treated and untreated atopic dogs: Comparison with a healthy control group.

The pathogenesis of anal sacculitis has not been extensively investigated, although atopic dogs seem to be predisposed to the disease. The aim of this study was therefore to characterize and compare the bacterial microbiota and pro-inflammatory cytokines in the anal sacs of dogs from three groups (healthy dogs, untreated atopic dogs and atopic dogs receiving antipruritic treatment or allergen-specific immunotherapy) in order to determine whether changes could be at the origin of anal sacculitis in atopic dogs. Bacterial populations of anal sac secretions from fifteen healthy dogs, fourteen untreated and six treated atopic dogs were characterized by sequencing the V4 region of the 16S rRNA gene using Illumina technology.

The hypothalamic-pituitary-gonadal axis and the enigma of Alzheimer disease sex differences.

Alzheimer disease has a sex bias, with women twice as likely as men to be affected. Studies have linked elevated follicle-stimulating hormone (FSH) levels to worsened Alzheimer disease pathology and cognitive decline in mice. FSH interacts with APOE4, uncovering new aspects of Alzheimer disease.

Comparison of intradermal and serum testing for environmental allergen-specific immunoglobulin E determination in a laboratory colony of cats with naturally acquired atopic syndrome.

Background: Allergen testing is used to select antigens included in the desensitisation vaccine. Intradermal skin test (IDT) is the gold standard in cats, yet allergen-specific immunoglobulin (Ig)E serological testing (ASIS) is often used. Feline data are lacking regarding the agreement between IDT and ASIS results.

Prevalence of cutaneous and mucosal lesions in dairy cattle admitted to a Canadian Veterinary Teaching Hospital from 2018 to 2019.

Background: The prevalence, anatomical distribution, or nature of cutaneous, hair and oral mucosal abnormalities (CHMAs) in cattle is uncertain.

Objectives: To determine how often dairy cattle admitted to a veterinary teaching hospital (VTH) had CHMAs (except for foot and ear canal) on physical examination and if there was an age-related difference.

Animals: Four hundred and thirty-three cattle: cattle <3 months (n = 85), cattle 3 to 24 months (n = 73), and cattle >24 months (n = 275).

Removal of senescent cells reduces the viral load and attenuates pulmonary and systemic inflammation in SARS-CoV-2-infected, aged hamsters.

Older age is one of the strongest risk factors for severe COVID-19. In this study, we determined whether age-associated cellular senescence contributes to the severity of experimental COVID-19. Aged golden hamsters accumulate senescent cells in the lungs, and the senolytic drug ABT-263, a BCL-2 inhibitor, depletes these cells at baseline and during SARS-CoV-2 infection.

Bilateral mastocytic and fibroblastic nodular proliferative dermatosis affecting ear margins in three domestic cats.

This case series describes the clinical appearance, histopathological findings and therapeutic trials of proliferative nodular lesions on bilateral ear margins of three domestic cats including two littermates. All therapeutic trials were unsuccessful. While the aetiology remains unclear, this report highlights different hypotheses in presenting this unusual inflammatory and fibroblastic dermatosis in cats.

Tanycytic networks mediate energy balance by feeding lactate to glucose-insensitive POMC neurons.

Hypothalamic glucose sensing enables an organism to match energy expenditure and food intake to circulating levels of glucose, the main energy source of the brain. Here, we established that tanycytes of the arcuate nucleus of the hypothalamus, specialized glia that line the wall of the third ventricle, convert brain glucose supplies into lactate that they transmit through monocarboxylate transporters to arcuate proopiomelanocortin neurons, which integrate this signal to drive their activity and to adapt the metabolic response to meet physiological demands. Furthermore, this transmission required the formation of extensive connexin-43 gap junction-mediated metabolic networks by arcuate tanycytes.

Whole genome sequencing of methicillin-resistant and methicillin-sensitive isolated from 4 horses in a veterinary teaching hospital and its ambulatory service.

Genomic characterization was conducted on 2 methicillin-resistant (MRSA) strains isolated from 2 horses hospitalized during an overlapping period of time and 2 methicillin-sensitive (MSSA) strains isolated from 2 distinct horses. Phylogenetic proximity was traced and the genotypic and phenotypic characteristics of the antimicrobial resistance of the strains were compared. Whole genome sequencing of MRSA strains for this report was similar but differed from whole genome sequencing of MSSA strains.

Description of the bacterial microbiota of anal sacs in healthy dogs.

The aim of the present study was to characterize the bacterial microbiota of anal sacs in healthy dogs using NGS. Swabs were used to sample the rectum and secretions from each anal sac in 15 healthy dogs. DNA was extracted from swabs and the V4 hypervariable region of the 16S rRNA gene was amplified and sequenced with Illumina MiSeq.

Vulvar calcinosis cutis in a female dog with urinary incontinence secondary to an ectopic ureter.

A 2-year-old, spayed female standard schnauzer dog was presented with a history of urinary incontinence and painful whitish lesions localized to the vulvar region. An ectopic ureter was diagnosed by cystoscopy. Histopathology of the biopsy specimens from the vulvar lesions was compatible with calcinosis cutis.

A retrospective study on methicillin-resistant spp. isolated from horses admitted to a Canadian veterinary teaching hospital between 2008 and 2018.

The goals of this retrospective study were to: determine the frequency of methicillin-resistant spp. (MRS) isolated from horses admitted to an equine veterinary teaching hospital in Quebec from 2008 to 2018, investigate the patterns of antimicrobial resistance (AMR), and evaluate the distribution of MRS and methicillin-sensitive spp. (MSS) by body site.

Equine herpesvirus 1-associated ulcerative dermatitis in a horse.

This case report describes the clinical and histopathological findings of an infection caused by equine herpesvirus-1 (EHV-1) in a horse showing respiratory signs and a papular, crusted and ulcerative dermatitis involving mucosae. This diagnosis was supported by real-time PCR positive for EHV-1 on nasal swabs and tissues.

Neuronal AMP-activated protein kinase hyper-activation induces synaptic loss by an autophagy-mediated process.

Alzheimer's disease (AD) is a neurodegenerative disorder characterized by synaptic loss that leads to the development of cognitive deficits. Synapses are neuronal structures that play a crucial role in memory formation and are known to consume most of the energy used in the brain. Interestingly, AMP-activated protein kinase (AMPK), the main intracellular energy sensor, is hyper-activated in degenerating neurons in several neurodegenerative diseases, including AD.

AMP-activated Protein Kinase Controls Immediate Early Genes Expression Following Synaptic Activation Through the PKA/CREB Pathway.

Long-term memory formation depends on the expression of immediate early genes (IEGs). Their expression, which is induced by synaptic activation, is mainly regulated by the 3',5'-cyclic AMP (cAMP)-dependent protein kinase/cAMP response element binding protein (cAMP-dependent protein kinase (PKA)/ cAMP response element binding (CREB)) signaling pathway. Synaptic activation being highly energy demanding, neurons must maintain their energetic homeostasis in order to successfully induce long-term memory formation.