Elamipretide mitigates ischemia-reperfusion injury in a swine model of hemorrhagic shock.

ischemia-reperfusion injury (IRI) after hemorrhage is potentiated by aortic occlusion or resuscitative endovascular balloon occlusion of the aorta (REBOA). Given the central role of mitochondrial injury in shock, we hypothesized that Elamipretide, a peptide that protects mitochondria, would mitigate IRI after hemorrhagic shock and REBOA. Twelve pigs were subjected to hemorrhagic shock and 45 min of REBOA. After 25 min of REBOA, animals received either saline or Elamipretide. Animals were transfused with autologous blood during balloon deflation, and pigs were resuscitated with isotonic crystalloids and norepinephrine for 4.25 h. Elamipretide-treated animals required less crystalloids than the controls (62.5 [50-90] and 25 [5-30] mL/kg, respectively), but similar amounts of norepinephrine (24.7 [8.6-39.3] and 9.7 [2.1-12.5] mcg/kg, respectively). Treatment animals had a significant reduction in serum creatinine (control: 2.7 [2.6-2.8]; Elamipretide: 2.4 [2.4-2.5] mg/dL; p = 0.04), troponin (control: 3.20 [2.14-5.47] ng/mL, Elamipretide: 0.22 [0.1-1.91] ng/mL; p = 0.03), and interleukin-6 concentrations at the end of the study. There were no differences in final plasma lactate concentration. Elamipretide reduced fluid requirements and protected the kidney and heart after profound IRI. Further understanding the subcellular consequences of REBOA and mitochondrial rescue will open new therapeutic avenues for patients suffering from IRI after hemorrhage.

Intra- and Extra-articular Features of Temporomandibular Joint Ankylosis in the Cat (Felis catus).

Temporomandibular joint (TMJ) ankylosis is an uncommon clinical entity in human and veterinary medicine. However, the condition is severely debilitating and is life-limiting if not treated. This study sought to characterize the intra- and extra-articular features of naturally occurring TMJ ankylosis in cats. TMJs from client-owned cats (n = 5) that underwent bilateral TMJ gap arthroplasty were examined and compared with TMJs from healthy, age-matched feline cadavers (n = 2) by cone-beam computed tomography (CBCT), micro-computed tomography (µCT) and histologically. Features of bilateral intra- and extra-articular ankylosis compounded by degenerative joint lesions were identified radiographically and histologically in all affected cats. Features of TMJ 'true' ankylosis included variable intracapsular fibro-osseous bridging, degeneration of the disc and the articular surfaces, narrowing of the joint space and flattening of the condylar process of the mandible. Extra-articular features of TMJ ankylosis included periarticular bone formation and fibro-osseous bridging between the mandible, zygomatic arch and coronoid process. In addition, subchondral bone loss or sclerosis, irregular and altered joint contours and irregularly increased density of the medullary bone characterized the degenerative changes of the osseous components of the TMJ. Complex radiological and histological features of both ankylosis and pseudoankylosis were identified that clinically manifested in complete inability to open the mouth.

The Temporomandibular Joint of the Domestic Dog (Canis lupus familiaris) in Health and Disease.

This study aimed to characterize the histological, biomechanical and biochemical properties of the temporomandibular joint (TMJ) of the domestic dog in health and disease. In addition, we sought to identify structure-function relationships and to characterize TMJ degenerative lesions that may be found naturally in this species. TMJs (n = 20) from fresh cadaver heads (n = 10) of domestic dogs were examined macroscopically and microscopically and by cone-beam computed tomography. The TMJ discs were evaluated for their mechanical and biochemical properties. If TMJ arthritic changes were found, pathological characteristics were described and compared with healthy joints. Five (50%) dogs demonstrated macroscopically normal fibrocartilaginous articular surfaces and fibrous discs and five (50%) dogs exhibited degenerative changes that were observed either in the articular surfaces or the discs. In the articulating surfaces, these changes included erosions, conformational changes and osteophytes. In the discs, degenerative changes were represented by full-thickness perforations. Histologically, pathological specimens demonstrated fibrillations with or without erosions, subchondral bone defects and subchondral bone sclerosis. Significant anisotropy in the TMJ discs was evident on histology and tensile mechanical testing. Specifically, the discs were significantly stiffer and stronger in the rostrocaudal direction compared with the mediolateral direction. No significant differences were detected in compressive properties of different disc regions. Biochemical analyses showed high collagen content and low glycosaminoglycan (GAG) content. No significant differences in biochemical composition, apart from GAG, were detected among the disc regions. GAG concentration was significantly higher in the central region as compared with the caudal (posterior) region. The TMJ of the domestic dog exhibits similarities, but also differences, compared with other mammals with regards to structure-function relationships. The TMJ articular surfaces and the disc exhibit degenerative changes as seen in other species, including perforation of the disc as seen in man. The degenerative changes had greater effects on the mechanical properties compared with the biochemical properties of the TMJ components. Translational motion of the TMJ does occur in dogs, but is limited.

Sphingomyelin lipidosis (Niemann-Pick disease) in a juvenile raccoon (Procyon lotor).

A wild caught juvenile male raccoon with neurological disease was humanely destroyed due to poor prognosis. Necropsy examination revealed hepatomegaly, splenomegaly and multicentric lymphadenomegaly with diffuse hepatic pallor and pulmonary consolidation with pinpoint pale subpleural foci. Microscopically, there was marked pale cytoplasmic swelling of the central and peripheral neurons as well as the glial cells in the brain, accompanied by multiorgan infiltration by abundant foamy macrophages. Ultrastructural investigation revealed accumulation of concentrically arranged lamellar material within lysosomes of the affected neurons, macrophages and endothelial cells. Biochemical enzymatic analysis detected sphingomyelinase deficiency and lysosomal storage disease consistent with sphingomyelin lipidosis (Niemann-Pick disease [NPD]) was diagnosed. This is the first report of NPD in a raccoon.

Lentiviral latency in peripheral CD4+ T cells isolated from feline immunodeficiency virus-infected cats during the asymptomatic phase is not associated with hypermethylation of the proviral promoter.

Lentiviral latency remains a principal obstacle to curative AIDS therapy. Transcriptional repression and latency permits lentiviruses to evade host immune responses and antiretroviral drugs. We have established a model of peripheral CD4+ T cell lentiviral latency in cats experimentally infected with feline immunodeficiency virus (FIV). Multiple mechanisms of lentiviral transcriptional repression have been proposed including epigenetic mechanisms resulting in promoter hypermethylation and/or chromatin condensation. Methylation of promoter-associated cytosines in the cytosine-guanine dinucleotide (CpG) has been associated with transcriptional repression in both eukaryotic promoters and integrated retroviral genomes. Using methylcytosine mapping, we examined the CpG methylation patterns in both the 5' and 3' long terminal repeats (LTR) of the FIV provirus in peripheral blood mononuclear cells, monocytes and CD4+ T cells isolated during the acute and asymptomatic phases of infection. Here we report no evidence that proviral promoter hypermethylation is associated with lentiviral latency in peripheral CD4+ T cells and monocytes obtained from experimentally FIV-infected cats.

Pathological evidence of pancreatitis in 43 horses (1986-2011).

REASONS FOR PERFORMING STUDY: Definitive ante mortem diagnosis of pancreatitis in horses is difficult. Reports summarising the most common clinical signs, clinicopathological features and concurrent disorders in horses with a definitive diagnosis of pancreatitis that may aid in the recognition of disease are lacking. OBJECTIVES: To describe case details, clinical signs, clinicopathological data and necropsy findings in horses with a definitive diagnosis of pancreatitis. METHODS: This was a retrospective study (1986-2011) and inclusion criteria consisted of horses with a definitive diagnosis of pancreatitis. A medical records database search was performed and data extracted included case details, clinical signs, clinical laboratory data and post mortem findings. Pancreatitis was defined as acute, active chronic or chronic and presumed primary or secondary, based on postmortem findings. RESULTS: Pancreatitis was diagnosed in 43 horses (acute pancreatitis in 34, active chronic in 4 and chronic in 5). A presumed diagnosis of primary pancreatitis was made in 6 horses. Pancreatitis was associated with gastrointestinal disorders in 28 horses (14 large colon, 10 small intestine and 4 gastric ruptures) and primary hepatic disease in 3 horses. Six horses had pancreatitis associated with other disorders: multiple endocrine neoplasia syndrome (one horse), strychnine toxicosis (one horse) and compromised immune system (4 horses). CONCLUSION: Pancreatitis is an uncommon disorder that can occur as a primary problem or secondary to gastrointestinal, hepatic or immunocompromising disorders, and when it occurs it affects adult horses more commonly. POTENTIAL RELEVANCE: Unexplained abdominal pain, gastric dilation or rupture, peritonitis and/or the presence of white fibrinous plaques and fat necrosis in the peritoneum and mesentery or mass-like structures in the root of the mesentery during an exploratory celiotomy should raise a suspicious of pancreatitis.

Systemic Coxiella-like infection with myocarditis and hepatitis in an eclectus parrot (Eclectus roratus).

A multiorgan infection with a Coxiella-like organism was determined to be the cause of death of a female eclectus parrot (Eclectus roratus). The diagnosis was based on gross lesions, histopathology, Gimenez and Gram special stains, immunohistochemistry, electron microscopy, and polymerase chain reaction amplification and sequencing of a bacterial 16s rRNA gene fragment isolated from hepatic and cardiac tissue. Gross postmortem examination revealed multifocal to coalescing foci of hepatic necrosis. The most significant histologic lesions included multifocal lymphohistiocytic necrotizing hepatitis, locally extensive lymphoplasmacytic myocarditis, and myocardial degeneration and necrosis. Intralesional cytoplasmic organisms were identified in cardiomyocytes, biliary epithelium, and pancreatic exocrine cells. This is the first description of a Coxiella-like organism with wide-ranging cellular tropisms in a psittacine bird. In addition, lymphoplasmacytic neuritis, myositis, splenitis, airsacculitis, and enteritis were detected. It is also the first report of a Coxiella-like infection in an eclectus parrot.

The presence or absence of the gamma-activated site determines IFN gamma-mediated transcriptional activation in CAEV promoters cloned from the mammary gland and joint synovium of a single CAEV-infected goat.

The caprine arthritis encephalitis virus (CAEV) long terminal repeat promoter was cloned and sequenced from mammary gland and carpal joint synovium isolated from a 15.5 year old, CAEV-infected Toggenburg doe with chronic mastitis and carpal arthritis. A deletion of the CAEV gamma activated site (GAS) was identified in the mammary gland but not the synovial isolate. Subsequent promoter-reporter gene construct experiments indicated that the GAS is necessary for interferon γ-mediated promoter activation. Utilizing a molecular clone of the classic isolate CAEV-CO, these findings were corroborated by a set of GAS mutant promoter-reporter constructs with and without the CAEV GAS. Results of experiments with U937 monocyte cell lines stably transfected with molecular clones of CAEV-CO GAS deletion mutants also indicated the GAS is necessary for IFNγ-mediated promoter activation. The mammary gland CAE viral isolate was propagated in caprine peripheral blood mononuclear cells and was assigned the name CAEV-MA. This is the first report describing two CAE viral isolates cloned from different anatomical locations in the same animal with and without the CAEV GAS, and is the first report detailing cytokine-induced CAEV promoter function in a naturally occurring ΔGAS promoter.

Expression of cytokeratins in the epithelium of canine odontogenic tumours.

Odontogenic tumours are considered to be relatively rare; however, several histologically distinct types have been identified in dogs. The more common canine odontogenic tumours are peripheral odontogenic fibroma and canine acanthomatous ameloblastoma. The expression of cytokeratins (CKs) has been established for the human dental germ and odontogenic tumours. The aim of the present study was to describe the immunohistochemical expression of a panel of CKs in the epithelium of the canine dental germ, normal gingiva and odontogenic tumours arising in this species. Samples from 20 odontogenic tumours, 12 tooth germs and three normal gingival tissues were obtained. Each sample was stained with haematoxylin and eosin and subjected to immunohistochemistry for CK expression. The typical expression pattern of CKs in the odontogenic epithelium and gingiva of dogs was CK14 and CK5/6. CKs 7, 8, 18 and 20 were generally absent from the canine dental germ, gingiva and odontogenic tumours. Dogs and man therefore exhibit similar CK expression in the odontogenic epithelium.

Analysis of immune cells within the healthy oral mucosa of specific pathogen-free cats.

The oral mucosa is an important interface for host-environment interactions. Based on previous studies, it is generally accepted that the cellular compartments of the oral immune system comprise organized mucosal-associated lymphoid tissues as well as diffusely and focally distributed T- and to lesser extent B-lymphocytes, oral mucosal Langerhans cells (OMLC), macrophages and mast cells. However, a comprehensive quantification of the cellular elements in the oral mucous membranes of the cat has not been reported. The aim of this study was to provide a comprehensive analysis of the immune cell compartments in the oral mucous membranes and anatomically related tissues of healthy cats. Multiple biopsies of the oral mucous membranes and related tissues were obtained from four specific pathogen-free cats for histological and immunohistochemical assessment of lymphocyte subsets, OMLC, macrophages and mast cells. T-lymphocyte subsets, OMLC, mast cells and macrophages were present in varying frequencies among the tissue compartments of the feline oral cavity. B-lymphocytes were not identified in any of the examined tissues except the tonsils and mandibular lymph nodes. Lymphocytic aggregates (follicles) were found in the palatoglossal folds and the gingiva. We describe the topographical distribution of various leucocyte subsets in the normal healthy feline oral mucosa, and demonstrate regional differences in the distribution of these cells.

Tissue tropism and promoter sequence variation in caprine arthritis encephalitis virus infected goats.

Caprine arthritis encephalitis virus is a lentivirus that infects goats and is closely related to maedi-visna virus of sheep. Infection with CAEV results in multiple discrete disease manifestations in goats which can include chronic arthritis, mastitis, pneumonia or encephalomyelitis. Presently, no satisfactory mechanistic rationale for viral tropism has been put forward. We propose that specific sequences in the lentiviral promoter (U3 region of the viral long terminal repeat) are associated with viral tissue tropism and subsequent disease expression. A total of 41 distinct CAE viral promoter regions were amplified, sequenced and phylogenetically compared from the tissues of 24 CAEV-infected goats demonstrating a variety of disease manifestations. Phylogenetically, we identified no tendency for clustering of these promoter sequences into tissue-specific groups. These results therefore do not provide evidence for the study hypothesis. However, multiple motifs within the U3 promoter region were highly conserved both within the entire collection of sequences and within tissue-specific groups.