Erosive and ulcerative stomatitis in dogs and cats: which immune-mediated diseases to consider?

Immune-mediated and autoimmune diseases of the skin often present with oral cavity involvement. Autoimmune subepidermal blistering diseases and pemphigus vulgaris are classic examples. While the primary lesions (vesicles and bullae) are relatively specific, these fragile lesions evolve rapidly into erosions and ulcers, which are lesion types that overlap with many diseases. Furthermore, some immune-mediated diseases such as severe adverse drug reactions, lupus diseases, canine uveodermatological syndrome, and vasculitis, may or may not involve the oral cavity, and often nonoral clinical manifestations are more diagnostic. In these situations, disease knowledge combined with signalment, lesion distribution, and history help to narrow the differentials. Surgical biopsy is required for confirmation in most diseases, while immunosuppressive treatments most typically involve glucocorticoids with or without nonsteroidal immunosuppressants.

Retrospective analysis of histologic lesions in captive arachnids.

Invertebrates, including arachnids, are a common taxon in zoological collections. Invertebrate medicine and pathology are emerging subspecialties, but there is limited reference material or published resources describing histologic lesions in arachnids. Histopathology of 26 captive arachnids (20 spiders and 6 scorpions) from institutional collections was reviewed. Most animals were found dead with limited clinical signs. Tissues evaluated included body wall (cuticle and epidermis), skeletal muscle, book lungs, digestive tract (pharynx, esophagus, sucking stomach, midgut tube, midgut diverticula, and stercoral pocket), central and peripheral nervous system, heart, hemolymph vessels and sinuses, Malpighian tubules, coxal glands, and gonads. Inflammation was frequent (24/26, 92%), and seen in multiple organs (18/24, 75%) with the midgut diverticulum most commonly affected (14/24, 58%) followed by the book lungs (13/24 arachnids, 54%), and body wall (8/24 arachnids, 33%). Inflammation comprised hemocyte accumulation, hemocytic coagula, melanization, and nodulation. Infectious agents, including bacteria (11/26, 42%), fungi (10/26, 38%), and parasites (2/26, 8%), were seen within inflammatory aggregates. Coinfection with multiple infectious agents was common (6/24, 25%). No etiologic agent was identified in 7/24 (29%) cases with inflammatory lesions. Lesions suggestive of decreased nutritional status or increased metabolic rate included midgut diverticula atrophy in 11/26 (42%) animals and skeletal muscle atrophy in 6/26 (23%) animals. Atrophic lesions were seen in combination with infection (8/11, 73%), pregnancy (2/11, 18%), male sex (2/11, 18%), or without other lesions (1/11, 9%). Other suspected contributors to death included dysecdysis-associated trauma (2/26, 8%) and uterine intussusception (1/26, 4%). No animals had neoplasia.

Aberrantly activated TAK1 links neuroinflammation and neuronal loss in Alzheimer's disease mouse models.

Neuroinflammation is causally associated with Alzheimer's disease (AD) pathology. Reactive glia cells secrete various neurotoxic factors that impair neuronal homeostasis eventually leading to neuronal loss. Although the glial activation mechanism in AD has been relatively well studied, how it perturbs intraneuronal signaling, which ultimately leads to neuronal cell death, remains poorly understood. Here, we report that compound stimulation with the neurotoxic factors TNF and glutamate aberrantly activates neuronal TAK1 (also known as MAP3K7), which promotes the pathogenesis of AD in mouse models. Glutamate-induced Ca2+ influx shifts TNF signaling to hyper-activate TAK1 enzymatic activity through Ca2+/calmodulin-dependent protein kinase II, which leads to necroptotic cellular damage. Genetic ablation and pharmacological inhibition of TAK1 ameliorated AD-associated neuronal loss and cognitive impairment in the AD model mice. Our findings provide a molecular mechanism linking cytokines, Ca2+ signaling and neuronal necroptosis in AD.

Legacy and emerging per- and polyfluoroalkyl substances suppress the neutrophil respiratory burst.

Per- and polyfluoroalkyl substances (PFASs) are used in a multitude of processes and products, including nonstick coatings, food wrappers, and fire-fighting foams. These chemicals are environmentally-persistent, ubiquitous, and can be detected in the serum of 98% of Americans. Despite evidence that PFASs alter adaptive immunity, few studies have investigated their effects on innate immunity. The report here presents results of studies that investigated the impact of nine environmentally-relevant PFASs [e.g. perfluorooctanoic acid (PFOA), perfluorooctane sulfonic acid potassium salt (PFOS-K), perfluorononanoic acid (PFNA), perfluorohexanoic acid (PFHxA), perfluorohexane sulfonic acid (PFHxS), perfluorobutane sulfonic acid (PFBS), ammonium perfluoro(2-methyl-3-oxahexanoate) (GenX), 7H-perfluoro-4-methyl-3,6-dioxa-octane sulfonic acid (Nafion byproduct 2), and perfluoromethoxyacetic acid sodium salt (PFMOAA-Na)] on one component of the innate immune response, the neutrophil respiratory burst. The respiratory burst is a key innate immune process by which microbicidal reactive oxygen species (ROS) are rapidly induced by neutrophils in response to pathogens; defects in the respiratory burst can increase susceptibility to infection. The study here utilized larval zebrafish, a human neutrophil-like cell line, and primary human neutrophils to ascertain whether PFAS exposure inhibits ROS production in the respiratory burst. It was observed that exposure to PFHxA and GenX suppresses the respiratory burst in zebrafish larvae and a human neutrophil-like cell line. GenX also suppressed the respiratory burst in primary human neutrophils. This report is the first to demonstrate that these PFASs suppress neutrophil function and support the utility of employing zebrafish larvae and a human cell line as screening tools to identify chemicals that may suppress human immune function.

Pathology in Practice.

In collaboration with the American College of Veterinary Pathologists.

Pulmonary exposure of mice to ammonium perfluoro(2-methyl-3-oxahexanoate) (GenX) suppresses the innate immune response to carbon black nanoparticles and stimulates lung cell proliferation.

BACKGROUND: Per- and polyfluoroalkyl substances (PFAS) have been associated with respiratory diseases in humans, yet the mechanisms through which PFAS cause susceptibility to inhaled agents is unknown. Herein, we investigated the effects of ammonium perfluoro(2-methyl-3-oxahexanoate) (GenX), an emerging PFAS, on the pulmonary immune response of mice to carbon black nanoparticles (CBNP). We hypothesized that pulmonary exposure to GenX would increase susceptibility to CBNP through suppression of innate immunity. METHODS: Male C57BL/6 mice were exposed to vehicle, 4 mg/kg CBNP, 10 mg/kg GenX, or CBNP and GenX by oropharyngeal aspiration. Bronchoalveolar lavage fluid (BALF) was collected at 1 and 14 days postexposure for cytokines and total protein. Lung tissue was harvested for histopathology, immunohistochemistry (Ki67 and phosphorylated (p)-STAT3), western blotting (p-STAT3 and p-NF-κB), and qRT-PCR for cytokine mRNAs. RESULTS: CBNP increased CXCL-1 and neutrophils in BALF at both time points evaluated. However, GenX/CBNP co-exposure reduced CBNP-induced CXCL-1 and neutrophils in BALF. Moreover, CXCL-1, CXCL-2 and IL-1ß mRNAs were increased by CBNP in lung tissue but reduced by GenX. Western blotting showed that CBNP induced p-NF-κB in lung tissue, while the GenX/CBNP co-exposed group displayed decreased p-NF-κB. Furthermore, mice exposed to GenX or GenX/CBNP displayed increased numbers of BALF macrophages undergoing mitosis and increased Ki67 immunostaining. This was correlated with increased p-STAT3 by western blotting and immunohistochemistry in lung tissue from mice co-exposed to GenX/CBNP. CONCLUSIONS: Pulmonary exposure to GenX suppressed CBNP-induced innate immune response in the lungs of mice yet promoted the proliferation of macrophages and lung epithelial cells.

Trunk-dominant and classic facial pemphigus foliaceus in dogs - comparison of anti-desmocollin-1 and anti-desmoglein-1 autoantibodies and clinical presentations.

BACKGROUND: Canine trunk-dominant pemphigus foliaceus (PF) is mentioned rarely in the literature. HYPOTHESIS/OBJECTIVES: The goal of this study was to provide clinical description of trunk-dominant PF and to demonstrate the prevalence of serum antikeratinocyte, anti-desmocollin-1 (DSC1) and anti-desmoglein-1 (DSG1) antibodies, and determine their diagnostic value in this particular PF phenotype. MATERIALS AND METHODS: Clinically relevant information was collected from 31, 25 and 34 dogs with trunk-dominant and facial PF and superficial pyoderma (SP), respectively. Sera from these dogs were tested for antikeratinocyte, anti-DSC1 and anti-DSG1 antibodies using indirect immunofluorescence on canine tissues and DSC1- and DSG1-transfected cells. Sera from healthy dogs and dogs with clinically irrelevant diseases served as controls. RESULTS: Footpad involvement and grouped/polycyclic lesion organisation were identified as features of both PF phenotypes, and not of SP. Antikeratinocyte immunoglobulin (Ig)G was not specific for canine PF. By contrast, antigen-specific IgG was detected only in PF sera; anti-DSC1 IgG in 100% and 58% of dogs with facial and trunk-dominant PF, respectively, and anti-DSG1 IgG in 7% of dogs with trunk-dominant PF only. CONCLUSIONS: Trunk-dominant PF shares DSC1 as a major autoantigen with facial PF. The ability to detect anti-DSC1 IgG is lower in trunk-dominant PF, yet despite the lower sensitivity, the positive predictive value and accuracy of this particular anti-DSC1 IgG test are high. A negative test result, however, cannot exclude the diagnosis, and characteristic clinical features such as footpad involvement and/or grouped/polycyclic lesions must be considered when distinguishing trunk-dominant PF from its most relevant differential diagnosis: SP.

Contexte - Le pemphigus foliacé (PF) dominant le tronc chez le chien est rarement mentionné dans la littérature. Hypothèse/Objectifs - Le but de cette étude était de fournir une description clinique du PF dominant le tronc et de démontrer la prévalence des anticorps sériques anti-kératinocytes, anti-desmocolline-1 (DSC1) et anti-desmogléine-1 (DSG1), et de déterminer leur valeur diagnostique dans ce phénotype particulier de PF. Matériels et méthodes - Des informations cliniquement pertinentes ont été recueillies auprès de 31, 25 et 34 chiens atteints respectivement de PF à dominante tronculaire et faciale et de pyodermite superficielle (SP). Les sera de ces chiens ont été testés pour les anticorps anti-kératinocytes, anti-DSC1 et anti-DSG1 en utilisant l'immunofluorescence indirecte sur des tissus canins et des cellules transfectées avec DSC1 et DSG1. Des sera de chiens sains et de chiens atteints de maladies cliniquement non pertinentes ont servi de témoins. Résultats - L'implication du coussinet plantaire et l'organisation des lésions groupées / polycycliques ont été identifiées comme des caractéristiques des deux phénotypes PF, et non de SP. L'immunoglobuline antikératinocytaire (Ig)G n'était pas spécifique du PF canin. En revanche, l'IgG spécifique de l'antigène n'a été détectée que dans les sera de PF ; IgG anti-DSC1 chez 100 % et 58 % des chiens atteints de PF faciale et tronc-dominante, respectivement, et anti-DSG1 IgG chez 7 % des chiens avec PF tronc-dominant uniquement. Conclusions - Le PF à dominante tronculaire partage DSC1 comme auto-antigène majeur avec le PF facial. La capacité à détecter les IgG anti-DSC1 est plus faible chez les PF à dominante tronculaire, mais malgré la sensibilité plus faible, la valeur prédictive positive et la précision de ce test IgG anti-DSC1 particulier sont élevées. Cependant, un résultat de test négatif ne peut pas exclure le diagnostic, et les caractéristiques cliniques caractéristiques telles que l'atteinte du coussinet plantaire et/ou les lésions groupées/polycycliques doivent être prises en compte lors de la distinction entre la PF à dominante tronculaire et son diagnostic différentiel le plus pertinent : la SP.

Introducción- el pénfigo foliáceo (PF) de distribución truncal predominante se describe raramente n la literatura. Hipótesis/Objetivos- el objetivo de este estudio fue proporcionar una descripción clínica del PF truncal y demostrar la prevalencia de anticuerpos séricos antiqueratinocitos, antidesmocolina-1 (DSC1) y antidesmogleína-1 (DSG1), y determinar su valor diagnóstico en este fenotipo PF particular. Materiales y métodos- se recopiló información clínicamente relevante de 31, 25 y 34 perros con PF dominante truncal, PF dominante facial y pioderma superficial (PS), respectivamente. Los sueros de estos perros se analizaron en busca de anticuerpos antiqueratinocitos, anti-DSC1 y anti-DSG1 mediante inmunofluorescencia indirecta en tejidos caninos y células transfectadas con DSC1 y DSG1. Sueros de perros sanos y perros con enfermedades clínicamente irrelevantes sirvieron como controles. Resultados- la afectación de la almohadilla plantar y la organización de lesiones agrupadas/policíclicas se identificaron como características de ambos fenotipos de PF y no de SP. La inmunoglobulina (Ig)G antiqueratinocitos no fue específica para la PF canina. Por el contrario, la IgG específica de antígeno se detectó solo en sueros PF; IgG anti-DSC1 en el 100 % y el 58 % de los perros con PF predominante en la cara y el tronco, respectivamente, y IgG anti-DSG1 en el 7 % de los perros con PF predominante en el tronco solamente. Conclusiones- el PF dominante truncal comparte DSC1 como un autoantígeno importante con el PF facial. La capacidad para detectar IgG anti-DSC1 es menor en la PF dominante truncal; sin embargo, a pesar de la menor sensibilidad, el valor predictivo positivo y la precisión de esta prueba de IgG anti-DSC1 en particular son altos. Sin embargo, un resultado negativo de la prueba no puede excluir el diagnóstico, y deben tenerse en cuenta las características clínicas, como la afectación de las almohadillas plantares y/o las lesiones agrupadas/policíclicas, al distinguir la PF dominante truncal de su diagnóstico diferencial más relevante: SP.

Contexto - O pênfigo foliáceo (PF) canino predominante no tronco é raramente relatado na literatura. Hipótese/Objetivos - O objetivo deste estudo foi apresentar a descrição clínica do PF predominante no tronco e demonstrar a prevalência de anticorpos anti-queratinócitos, anti-desmocolina-1 (DSC1) e anti-desmogleína-1 (DSG1), e determinar o seu potencial diagnóstico neste tipo particular de PF. Materiais e métodos - Informações clinicamente relevantes foram coletadas de 31, 25 e 34 cães com PF predominante no tronco, PF facial e piodermite superficial (PS), respectivamente. Os soros destes cães foram testados para anticorpos anti-queratinócitos, anti-DSC1 e anti-DSG1 utilizando imunofluorescência indireta em tecidos caninos e em células DSC1 e DSG1 transfectadas. Os soros de cães saudáveis e cães com doenças clinicamente irrelevantes serviram de controle. Resultados - O acometimento dos coxins e a organização agrupada/policíclica das lesões foram identificadas como características de ambos os fenótipos de PF, não de PS. A imunoglobulina (Ig)G anti-queratinócitos não foi específica para PF. Em contraste, IgG antígeno-específica foi detectada apenas no soro de PF; IgG anti-DSC1 em 100% e 58% dos cães com PF facial e predominante no tronco, respectivamente, e IgG anti-DSG1 em 7% dos cães somente acometidos pelo PF predominante no tronco. Conclusões - O PF predominante no tronco compartilha DSC1 como um autoantígeno principal com PF facial. A capacidade de detectar IgG anti-DSC1 é menor no PF predominante no tronco, mas apesar da sensibilidade mais baixa, o valor preditivo positivo e a precisão do teste IgG anti-DSC1 específico são altos. Um resultado de teste negativo, no entanto, não pode excluir o diagnóstico, e características clínicas típicas, como envolvimento do coxim plantar e/ou lesões agrupadas/policíclicas, devem ser consideradas ao distinguir PF predominante no tronco de seu diagnóstico diferencial mais relevante: PS.

Cutaneous epitheliotropic lymphosarcoma in a captive white catfish (Ameiurus catus Linnaeus).

A wild caught white catfish (Ameiurus catus Linnaeus) developed multiple cutaneous masses. Cytology revealed neoplastic lymphocytes and microscopy confirmed dermal infiltration with epitheliotropism in the epidermis, oral mucosa, and cornea, without internal organ involvement. Transmission electron microscopy did not identify viral particles. Histopathology supported cutaneous epitheliotropic lymphosarcoma, a condition most commonly reported in mammals. This is the first reported case of cutaneous epitheliotropic lymphosarcoma in an ictalurid and one of the few published cases of this condition in any fish species.

Cutaneous mast cell tumors in 11 miniature pigs: a retrospective study.

Better understanding of mast cell tumors (MCTs) in miniature pigs is needed to guide diagnosis and establish clinical significance. We characterized the gross pathology, histopathology, histochemical staining, and KIT immunoreactivity of cutaneous MCTs in a retrospective descriptive study of 11 miniature pigs (Sus scrofa domesticus). Tumors were single or multiple papules, small nodules, or plaques. In one pig, lymph nodes and internal organs were affected. Histologically, all MCTs involved the dermis, and some extended to the subcutis (4 of 11) and skeletal muscle (1 of 11). Most tumors were well-demarcated, unencapsulated, nodular or multinodular masses (8 of 11) and fewer were poorly demarcated plaques (3 of 11). Neoplastic cells were often well-differentiated with pale amphophilic-to-eosinophilic faintly granular cytoplasm, occasional binucleation, rare multinucleation, and a low mitotic count (<7 per 10 hpf; 10 of 11). Eosinophils were present in tumors in all cases. Cytoplasmic granules stained most consistently with high-pH (2.5-3) toluidine blue (9 of 10) compared to low-pH (0.5-1) toluidine blue (6 of 9) or Giemsa (7 of 10). KIT immunoreactivity patterns were strong perimembranous (4 of 8), focal perinuclear and stippled cytoplasmic (1 of 8), and diffuse cytoplasmic (3 of 8), and included 1 case that was negative for histochemical stains; hence, KIT is a promising diagnostic marker for MCTs in miniature pigs.

Localised erythema multiforme-like reaction confined to a region of clipper burn in a dog.

Localised erythema multiforme (LEM) is only reported to occur in humans and not in domestic species. This case report describes the clinical and histopathological features of LEM-like reaction in a dog, confined to a region of clipper burn.

L'érythème polymorphe localisé (LEM) n'est signalé que chez l'homme et non chez les animaux domestiques. Ce cas clinique décrit les caractéristiques cliniques et histopathologiques d'une réaction de type LEM chez un chien, localisé sur une région de brûlure de tondeuse.

El eritema multiforme localizado (LEM) sólo se ha descrito en seres humanos y no en especies domésticas. Este artículo describe un caso de un perro con una lesión confinada a una zona de quemadura por un rasurador cuyas características clínicas e histopatológicas fueron similares a LEM.

O eritema multiforme localizado (EML) é relatado apenas em humanos e não em animais domésticos. Este relato de caso descreve as características clínicas e histopatológicas de uma reação EML-símile em um cão, limitada a uma região de queimadura por lâmina de tosa.

Ameloblastic carcinoma in horses: case report and literature review.

Ameloblastic carcinoma is a malignant odontogenic neoplasm that has been reported only rarely in veterinary species. A 16-y-old Arabian crossbred mare was presented for evaluation of a hard mass on the body of the mandible, with evidence of osteolysis on radiographs. Incisional biopsies revealed an invasive neoplasm comprised of spindloid epithelial cells with a high mitotic count and partial dual cytokeratin-vimentin immunoreactivity. The horse was euthanized because of rapid tumor progression 3 mo after presentation. Postmortem evaluation revealed partial obliteration of the mandible by a large, firm-to-hard, tan, locally destructive and invasive mass with no gross or histologic evidence of metastasis. Postmortem histology revealed a poorly differentiated epithelial neoplasm with variably prominent features suggestive of odontogenic histogenesis: a plexiform ribbon architecture, infrequent basilar palisading with antibasilar nuclei, rare basilar cytoplasmic clearing, subepithelial matrix hyalinization, and partial dual cytokeratin-vimentin immunoreactivity. Features of malignancy included regions of necrosis, pronounced cellular atypia, a high mitotic count, extensive tissue invasion and local tissue destruction, and extension of neoplastic cells beyond the margins of the mandibular bone. Collectively, these features are most consistent with mandibular ameloblastic carcinoma. Including our case described here, ameloblastic carcinoma has been reported in only 5 horses. The microscopic features reported most consistently are dual cytokeratin-vimentin immunoreactivity, a high mitotic count, and basilar palisading. Ameloblastic carcinoma should be considered as a differential diagnosis for rapidly growing, locally invasive masses arising from the dentate jaw of horses.

Canine junctional epidermolysis bullosa due to a novel mutation in LAMA3 with severe upper respiratory involvement.

BACKGROUND: Junctional epidermolysis bullosa (JEB) is a group of congenital blistering skin diseases characterized by clefting through the lamina lucida of the basement membrane zone. OBJECTIVES: To characterize the clinical and morphological features of a congenital mechanobullous disease in a litter of puppies with severe upper respiratory involvement, and to identify an associated genetic variant. ANIMALS: Five of eight puppies in an Australian cattle dog cross-bred litter showed signs of skin fragility. Three were stillborn and one died at one month of age. The two surviving puppies were presented with blistering skin disease and severe respiratory distress. Additionally, one unaffected sibling was examined and blood was obtained for genetic testing. METHODS AND MATERIALS: Post-mortem examination, histopathological evaluation and electron microscopy were performed. Whole genome sequencing (WGS) of one affected puppy was compared to a database of 522 dogs of 55 different breeds for variant analysis. Sanger sequencing of one additional affected and one unaffected sibling confirmed the variant. RESULTS: Clinically, severe mucocutaneous ulcers occurred in frictional areas with claw sloughing. Histopathological results revealed subepidermal clefts and electron microscopy confirmed the split in the lamina lucida. Post-mortem examination documented extensive pharyngeal and laryngeal lesions with granulation tissue and fibrinous exudate obscuring the airway. Moderate tracheal hypoplasia contributed. The WGS revealed a novel missense variant in the laminin α3-chain XP_537297.2p(Asp2867Val), with an autosomal recessive mode of inheritance. CONCLUSIONS AND CLINICAL RELEVANCE: A novel variant in LAMA3 caused a generalized and severe phenotype of JEB with an unique clinical presentation of upper airway obstruction.

Bullous amyloidosis in a horse: first description in veterinary medicine.

BACKGROUND: Bullous amyloidosis is a rare disease in humans that has not been described in a veterinary species in the peer-reviewed literature. The human disease is characterised by haemorrhagic vesicles and bullae on the skin and mucosae, which form due to amyloid deposition. HYPOTHESIS/OBJECTIVES: To describe the clinical features, laboratory analysis and histopathological features of an unique presentation of bullous disease in a horse. ANIMALS: A 17-year-old thoroughbred mare presented for weight loss and severe oral cavity ulcers. METHODS AND MATERIALS: Investigations involved haematological evaluation, chemistry profiles, gastroscopy and serum protein electrophoresis, and, postmortem, histopathological evaluation, Congo-red staining and transmission electron microscopy (TEM). RESULTS: Haemorrhagic vesicles and bullae occurred on the mucosa of the oral cavity, lips, oesophagus and stomach, and much less the muzzle, face and mucocutaneous areas of the perineum, where scarring was evident. Histopathological evaluation and Congo-red staining confirmed the presence of amyloid deposits in dermis and submucosa, in association with vesicle and bulla formation, consistent with bullous amyloidosis. TEM confirmed amyloid fibril deposition in the dermis and along the basement membrane zone. Clefts occurred in the superficial dermis and submucosa, which explained haemorrhage and scarring. The presence of a polyclonal gammopathy and the rapid abolishment of Congo-red staining with performate pretreatment supported serum amyloid A and secondary amyloidosis. CONCLUSION AND CLINICAL IMPORTANCE: Bullous amyloidosis is a novel disease of the horse and a newly recognised differential for bullous disease, for which the haemorrhagic nature of bullae, scarring and deep secondary ulcers are considered clinical clues to the condition.

Three-dimensional (3D) imaging of lipids in skin tissues with infrared matrix-assisted laser desorption electrospray ionization (MALDESI) mass spectrometry.

Three-dimensional (3D) mass spectrometry imaging (MSI) has become a growing frontier as it has the potential to provide a 3D representation of analytes in a label-free, untargeted, and chemically specific manner. The most common 3D MSI is accomplished by the reconstruction of 2D MSI from serial cryosections; however, this presents significant challenges in image alignment and registration. An alternative method would be to sequentially image a sample by consecutive ablation events to create a 3D image. In this study, we describe the use of infrared matrix-assisted laser desorption electrospray ionization (IR-MALDESI) in ablation-based 3D MSI for analyses of lipids within fresh frozen skin tissue. Depth resolution using different laser energy levels was explored with a confocal laser scanning microscope to establish the imaging parameters for skin. The lowest and highest laser energy level resulted in a depth resolution of 7 µm and 18 µm, respectively. A total of 594 lipids were putatively detected and detailed lipid profiles across different skin layers were revealed in a 56-layer 3D imaging experiment. Correlated with histological information, the skin structure was characterized with differential lipid distributions with a lateral resolution of 50 µm and a z resolution of 7 µm.

Deep pemphigus (pemphigus vulgaris, pemphigus vegetans and paraneoplastic pemphigus) in dogs, cats and horses: a comprehensive review.

Pemphigus is the term used to describe a group of rare mucocutaneous autoimmune bullous diseases characterized by flaccid blisters and erosions of the mucous membranes and/or skin. When the autoantibodies target desmosomes in the deep layers of the epidermis, deep pemphigus variants such as pemphigus vulgaris, pemphigus vegetans and paraneoplastic pemphigus develop. In this article, we will review the signalment, clinical signs, histopathology and treatment outcome of pemphigus vulgaris, pemphigus vegetans and paraneoplastic pemphigus in dogs, cats and horses; where pertinent, we compare the animal diseases to their human homologue. Canine, feline and equine pemphigus vulgaris, pemphigus vegetans and paraneoplastic pemphigus have many features similar to the human counterpart. These chronic and often relapsing autoimmune dermatoses require aggressive immunosuppressive therapy. In animals, the partial-to-complete remission of pemphigus vulgaris and pemphigus vegetans has been achieved with high dose glucocorticoid therapy, with or without adjunct immunosuppressants; the prognosis is grave for paraneoplastic pemphigus.

Sex differences in the acute and subchronic lung inflammatory responses of mice to nickel nanoparticles.

Nickel nanoparticles (NiNPs) are increasingly used in nanotechnology applications, yet information on sex differences in NiNP-induced lung disease is lacking. The goal of this study was to explore mechanisms of susceptibility between male and female mice after acute or subchronic pulmonary exposure to NiNPs. For acute exposure, male and female mice received a single dose of NiNPs with or without LPS by oropharyngeal aspiration and were necropsied 24 h later. For subchronic exposure, mice received NiNPs with or without LPS six times over 3 weeks prior to necropsy. After acute exposure to NiNPs and LPS, male mice had elevated cytokines (CXCL1 and IL-6) and more neutrophils in bronchoalveolar lavage fluid (BALF), along with greater STAT3 phosphorylation in lung tissue. After subchronic exposure to NiNPs and LPS, male mice exhibited increased monocytes in BALF. Moreover, subchronic exposure of male mice to NiNP only induced higher CXCL1 and CCL2 in BALF along with increased alveolar infiltrates and CCL2 in lung tissue. STAT1 in lung tissue was induced by subchronic exposure to NiNPs in females but not males. Males had a greater induction of IL-6 mRNA in liver after acute exposure to NiNPs and LPS, and greater CCL2 mRNA in liver after subchronic NiNP exposure. These data indicate that susceptibility of males to acute lung inflammation involves enhanced neutrophilia with increased CXCL1 and IL-6/STAT3 signaling, whereas susceptibility to subchronic lung inflammation involves enhanced monocytic infiltration with increased CXCL1 and CCL2. STAT transcription factors appear to play a role in these sex differences. This study demonstrates sex differences in the lung inflammatory response of mice to NiNPs that has implications for human disease.

Rapid response of hyperkeratotic erythema multiforme to oclacitinib in two dogs.

BACKGROUND: Hyperkeratotic erythema multiforme (HKEM) is a clinically distinct dermatosis and poorly characterized syndrome, comprised of hyperkeratotic plaques with variable symmetry and apoptosis similar to "classic" erosive canine EM. Hyperkeratotic EM has a protracted clinical course and, although treatments with glucocorticoids, azathioprine and/or ciclosporin have been tried, rates of remission are low. OBJECTIVES: To describe successful treatment of HKEM in two dogs using oclacitinib. ANIMALS: A 7-year-old, spayed Havanese dog (Case 1) and a 1-year-old, intact cryptorchid Dachshund dog (Case 2). METHODS: Case characterization and clinical diagnoses were based on lesion character, surgical biopsy, cytological evaluation, culture, direct immunofluorescence (DIF) and expected responses to treatments. RESULTS: Both cases exhibited multifocal, often symmetrical hyperkeratotic plaques with adherent scale. Histological findings revealed prominent epidermal hyperplasia, parakeratotic hyperkeratosis, lymphocytic dermatitis and transepidermal apoptosis with lymphocytic satellitosis. DIF revealed fine, patchy IgG, IgM and IgA basement membrane deposits (Case 2). Both dogs exhibited rapid improvement with oral oclacitinib (0.6-0.9 mg/kg twice daily) with a complete remission of clinical signs observed in 12 and seven weeks in cases 1 and 2, respectively. CONCLUSION AND CLINICAL IMPORTANCE: Oclacitinib could be considered as a fast-acting and effective treatment option for HKEM in dogs.

Cutaneous polyautoimmunity in two unrelated dogs: pemphigus foliaceus and generalized discoid lupus erythematosus.

BACKGROUND: Polyautoimmunity, the concurrent expression of two or more distinct autoimmune diseases (ADs) in a single individual, is a known phenomenon in humans and has been rarely reported in dogs. To the best of the authors' knowledge, comorbid pemphigus foliaceus (PF) and generalized discoid lupus erythematosus (GDLE) has not been reported in dogs. HYPOTHESIS/OBJECTIVES: To describe the clinical, histological and immunological features and treatment outcome of two unrelated dogs with comorbid PF and GDLE. ANIMALS: One 10-year-old, spayed German shepherd dog and one 8-year-old, castrated American Staffordshire terrier presented for evaluation of a symmetrical, facial- and/or pedal-dominant pustular dermatitis with concurrent, truncal scaly plaques. METHODS: For each dog, clinicopathological characterization included physical examination, lesion cytological evaluation, bacterial culture and sensitivity testing, skin histopathological investigation and direct and indirect immunofluorescence testing. Additional diagnostic imaging and haematological testing was performed to exclude extracutaneous disease. RESULTS: Both dogs exhibited lesions clinically and histologically compatible with PF and GDLE. Moreover, one dog exhibited generalized leucotrichia and chronic superficial keratitis. Remission was achieved with immunosuppressive dosages of prednisolone [high-dose pulse (Case 1) or standard immunosuppressive dosage (Case 2)] and ciclosporin (5-6 mg/kg/day). Tissue-bound antikeratinocyte immunoglobulin (Ig)G and IgM were detected in both dogs. A weak basement membrane zone deposit of C3 was seen in one dog. Circulating antikeratinocyte and anti-desmocollin-1 IgG were detected in one dog. CONCLUSIONS AND CLINICAL IMPORTANCE: Cutaneous polyautoimmunity can occur in the dog. Depending on the specific disease combinations, overlapping clinical features may present diagnostic and/or therapeutic challenges. Moreover, these cases should be monitored for development of additional cutaneous or extra-cutaneous AD(s).

Physiological response, function of sweat glands, and hair follicle cycling in cattle in response to fescue toxicosis and hair genotype.

Fescue toxicosis is a syndrome that results when cattle consume toxic endophyte-infected tall fescue. The objective of this study was to compare the response in physiological variables, sweat gland function, hair follicle cycling, and gene expression to feeding a total mixed ration that included tall fescue haylage and tall fescue seed containing a toxic endophyte (EI) or tall fescue haylage containing a nontoxic novel endophyte (EN) in beef heifers (Angus × Senepol heifers, n = 31) with 2 different hair genotypes. Numbers in each subgroup were as follows: novel endophyte, heterozygous slick (EN-S; n = 8), novel endophyte, homozygous hairy (wild type, EN-W; n = 7), endophyte-infected, heterozygous slick (EI-S; n = 10), and endophyte-infected, homozygous hairy (wild type, EI-W; n = 6). Physiological measurements were taken weekly for 7 wk. Data were analyzed using the MIXED procedure of SAS including dietary fescue treatment (EN vs. EI) and hair genotype (S vs. W) as main effects, day as a repeated measure, and temperature-humidity index (THI) as a covariate. Skin biopsies were taken before treatment initiation and on day 37 of treatment. Average surface temperature (ST) increased as the THI increased (P < 0.0001). Average ST was greater (P < 0.01) for animals fed EI than for animals fed the EN fescue diet, and greater (P < 0.01) for animals with the W genotype compared with animals with the S genotype. The difference between heifers with the S and W genotype was greater at greater THI (genotype × day interaction, P < 0.01). Transepidermal water loss (TEWL) was greater (P < 0.05) for animals with the S genotype compared with the W genotype and greater (P < 0.05) for heifers with the S genotype than for heifers with the W genotype when fed EI (36.7, 38.5, 30.0, and 38.7 g/m2 per hour for EN-W, EN-S, EI-W, and EI-S, respectively). The fraction of follicles in telogen in plucked hair samples for heifers fed EI was greater for animals with the S genotype than the W genotype (fraction in telogen: 0.456, 0.565, 0.297, 0.702 for EN-W, EN-S, EI-W, and EI-S, respectively; diet × genotype interaction, P < 0.05). Fraction of follicles in anagen was the opposite. EI fescue resulted in increased ST, changes in hair follicle cycling that support greater hair growth, and decreased TEWL for heifers with the W genotype compared with S genotype, suggesting greater heat stress in response to EI.

Detection of Bartonella spp. in dogs after infection with Rickettsia rickettsii.

BACKGROUND: Dynamics of infection by Bartonella and Rickettsia species, which are epidemiologically associated in dogs, have not been explored in a controlled setting. OBJECTIVES: Describe an outbreak investigation of occult Bartonella spp. infection among a group of dogs, discovered after experimentally induced Rickettsia rickettsii (Rr) infection. ANIMALS: Six apparently healthy purpose-bred Beagles obtained from a commercial vendor. METHODS: Retrospective and prospective study. Dogs were serially tested for Bartonella spp. and Rr using serology, culture, and PCR, over 3 study phases: 3 months before inoculation with Rr (retrospective), 6 weeks after inoculation with Rr (retrospective), and 8 months of follow-up (prospective). RESULTS: Before Rr infection, 1 dog was Bartonella henselae (Bh) immunofluorescent antibody assay (IFA) seroreactive and 1 was Rickettsia spp. IFA seroreactive. After inoculation with Rr, all dogs developed mild Rocky Mountain spotted fever compatible with low-dose Rr infection, seroconverted to Rickettsia spp. within 4-11 days, and recovered within 1 week. When 1 dog developed ear tip vasculitis with intra-lesional Bh, an investigation of Bartonella spp. infection was undertaken. All dogs had seroconverted to 1-3 Bartonella spp. between 7 and 18 days after Rr inoculation. Between 4 and 8 months after Rr inoculation, Bh DNA was amplified from multiple tissues from 2 dogs, and Bartonella vinsonii subsp. berkhoffii (Bvb) DNA was amplified from 4 of 5 dogs' oral swabs. CONCLUSIONS AND CLINICAL IMPORTANCE: Vector-borne disease exposure was demonstrated in research dogs from a commercial vendor. Despite limitations, our results support the possibilities of recrudescence of chronic subclinical Bartonella spp. infection after Rr infection and horizontal direct-contact transmission between dogs.