Constitutive Innate Immunity and Systemic Responses to Infection of the American Alligator (Alligator mississippiensis).

Uninfected alligators (Alligator mississippiensis) exhibited high constitutive levels of hepatic gene expression related to immune function, whereas the highest-expressed hepatic genes of uninfected mice were related to metabolism. Intraperitoneal challenge of mice with bacterial lipopolysaccharide results in dramatic inflammatory effects including peritoneal ascites, febrile response, dramatic alterations in electrophoretic serum profile, and mortality. In contrast, coelomic injection of alligators with 200× the murine LD50 of intraperitoneal bacterial lipopolysaccharide resulted in no changes in serum protein profiles, behavioral effects, mortality, and no coelomic ascites. However, injection of juvenile alligators with live bacteria resulted in a titer-dependent decrease in metabolic rate, as measured by oxygen consumption. These results are the opposite of those observed for mammalian and avian species. The decreased oxygen consumption was not accompanied by changes in heart or respiration rate, indicating that this phenomenon was not due to bradycardia or bradypnea. Interestingly, challenge of alligators with bacteria resulted in the complete expulsion of digestive tract contents within four hours. We interpret these activities as temporary minimization of other biological systemic activities to redirect and devote energy to immune function. The reallocation of resources within an organism to fight infection without increases in metabolic rate has not been described in other animals.

Disseminated Aspergillus citrinoterreus and concurrent localized dermal phaeohyphomycosis in an immunosuppressed dog.

Key Clinical message: We report on a dog with immune-mediated hemolytic anemia (IMHA) treated with immunomodulatory therapy that developed phaeohyphomycosis and Aspergillus citrinoterreus infections. This is the first reported case of A. citrinoterreus in dogs. It details cytological and microbiological findings leading to diagnosis and highlights the importance of investigating new lesions in immunocompromised patients. Abstract: A 5-year-old Staffordshire terrier mix treated with immunosuppressive therapy for IMHA was diagnosed with concurrent disseminated A. citrinoterreus and localized Curvularia lunata infections. This case highlights the potential development of multiple concurrent opportunistic fungal infections and is the first reported case of A. citrinoterreus infection in a dog.

Evaluation of serum 25-hydroxyvitamin D, C-reactive protein, and haptoglobin as biomarkers in dogs newly diagnosed with histoplasmosis.

BACKGROUND: Serum 25-hydroxyvitamin (OH)D, C-reactive protein (CRP), and haptoglobin are useful biomarkers in various infectious diseases and inflammatory disorders in dogs, but their utility in histoplasmosis is unknown. OBJECTIVE: Determine if serum 25(OH)D, CRP, and haptoglobin concentrations are different in dogs with histoplasmosis compared to healthy controls and whether serum globulin, albumin, CRP, or haptoglobin are associated with 25(OH)D concentration. ANIMALS: Twenty-two client-owned dogs (histoplasmosis, n = 12; controls, n = 10). METHODS: Prospective case-control study. Dogs with histoplasmosis were categorized as pulmonary, disseminated, or gastrointestinal (GI) tract. Serum 25(OH)D was measured using modified high-performance liquid chromatography (HPLC). Serum CRP and haptoglobin were measured with ELISA assays. RESULTS: Dogs with histoplasmosis were grouped as disseminated (n = 8) and GI tract (n = 4). No dogs had pulmonary tract involvement alone. Dogs with histoplasmosis (median, interquartile range [IQR]; 11.6 ng/mL, 16.8) had lower serum 25(OH)D concentrations than controls (35.7 ng/mL, 17.6; P < .001). Serum CRP and haptoglobin concentrations were higher in dogs with histoplasmosis (CRP: median, IQR; 63.5 mg/L, 37.1 and haptoglobin: 459.7 mg/dL, 419.6) than controls (CRP: 1.9 mg/L, 2; P < .001 and haptoglobin: 85.5 mg/dL, 106.7; P = .003). Serum 25(OH)D concentration was positively associated with fold change in serum albumin concentration (ρ = 0.77; P < .001), and negatively associated with fold change in serum globulin (ρ = -0.61; P = .003) and CRP concentrations (ρ = -0.56; P = .01). CONCLUSION AND CLINICAL IMPORTANCE: Assay of serum 25(OH)D, CRP, and haptoglobin could have clinical value in dogs with histoplasmosis.

Case Report: Cutaneous Pleomorphic Lymphangiosarcoma in a Dog Exhibiting Features of Human Composite Hemangioendothelioma.

Background: Angiosarcomas are a broad category of vascular origin neoplasms that are poorly characterized in veterinary species. Lymphangiosarcoma (LAS) is an uncommon type of angiosarcoma reported in humans and canines arising from lymphatic endothelium. LAS can be differentiated from other angiosarcomas in dogs based on expression of Prospero-related homeobox gene-1 (PROX-1) or lymphatic vessel endothelial receptor-1 (LYVE-1). Composite hemangioendothelioma (CHE) is a rare angiosarcoma subtype described in people and characterized by a variable biologic behavior and infrequent metastasis. This variant of angiosarcoma histologically combines features of retiform hemangioendothelioma and epithelioid hemangioendothelioma. Information regarding the cytologic and histopathologic appearance and clinical course of dogs with vascular tumors that exhibit features of CHE are unknown. Here, we report a case of pleomorphic LAS with features of CHE arising in a dog and treated with surgery and adjuvant chemotherapy. Case presentation: A 10-year-old intact male Labrador retriever presented with an approximately 6-cm-diameter cutaneous mass caudal to the left elbow that was progressively growing over 1.5 years. On physical examination, palpable extensions were identified coursing proximally over the triceps with concurrent loco-regional peripheral lymphadenopathy. Fine needle aspirates (FNA) and cytologic assessment of the cutaneous mass, left prescapular, and accessory axillary lymph nodes reported that this appeared to be a metastatic epithelial neoplasm, although a mixed carcinoma or collision tumor could not be excluded. An incisional biopsy of the mass was submitted for histopathology and was consistent with a well-differentiated angiosarcoma with features of CHE. The neoplasm expressed vimentin, CD31, von Willebrand factor (vWf), and PROX-1, supporting the diagnosis of LAS. Complete staging was performed, and no additional metastatic lesions were identified. Left forelimb amputation and lymph node removal were performed. Based on the diagnosis of metastatic LAS, doxorubicin chemotherapy was administered. 7 months post-amputation, the tumor recurred at the amputation site without evidence of metastatic disease. Conclusion: This report describes a malignant, locally aggressive lymphatic origin vascular tumor in a dog, with features consistent with descriptions of CHE in humans. Cytologic features in this case were discordant with its true mesenchymal etiology, obfuscating diagnosis. The morphologic features of the mesenchymal neoplastic population and immunohistochemistry (IHC) labeling ultimately supported a diagnosis of pleomorphic LAS with features of CHE.

Comparison of pathologist review protocols for cytologic detection of prostatic and urothelial carcinomas in canines: A bi-institutional retrospective study of 298 cases.

Urothelial carcinoma, also known as transitional cell carcinoma, is the most common primary bladder tumour in dogs, and can also involve the prostate gland. Cytology is a common diagnostic tool utilized for dogs with bladder or prostate gland lesions. The objectives of this retrospective study were to compare the sensitivity and specificity of cytologic evaluation for urothelial or prostatic carcinoma between two institutions with different cytology review protocols as well as determine if certain collection methods resulted in higher cytologic accuracy. A total of 298 cases met inclusion criteria. The overall sensitivity and specificity for institution 1 were 91.8% and 50%, respectively, compared to 31.1% and 97.4%, respectively, for institution 2. When the urine sample review protocol at institution 2 was matched to that of institution 1, sensitivity and specificity were more similar to institution 1 (71.2% and 88.9%, respectively). Our results show that the sensitivity and specificity of cytology are affected by screening and review protocols implemented by different institutions. The data also demonstrate that sensitivity and specificity vary by collection method. Diagnostic catheterization had the highest performance: of the 11 cases between two institutions, it had 100% sensitivity and specificity. In contrast, examination of urine sediment not collected via diagnostic catheterization had low sensitivity and specificity that varied greatly by institution. In summary, cytologic interpretation should be undertaken with consideration given to both processing and collection protocols.

Coccidioides posadasii in a Dog With Cervical Dissemination Complicated by Esophageal Fistula.

A 5-year-old male, neutered mixed breed dog with a history of a mass with an associated draining tract on the ventral cervical region was diagnosed with an esophageal fistula. The dog exhibited serosanguinous discharge from the draining tract, with enlarged left superficial cervical and mandibular lymph nodes, and was reported to have difficulty with deglutition of solid foods. Computed tomography revealed a communication of the draining tract with the esophagus along with enlargement of the left lateral retropharyngeal, left medial retropharyngeal, and mandibular lymph nodes. This prompted surgical exploration and debridement of the site, with closure of the esophageal fistula. Histopathology of thyroid gland, skeletal muscle, and adipose tissue obtained during surgical exploration showed spherules consistent with Coccidioides spp. infection. Antibody titers performed post-operatively were consistent with an active Coccidioides spp. Infection. By fungal culture and subsequent PCR and DNA sequencing, C. posadasii was identified as the species infecting the dog. Over the course of 85 days of antifungal therapy, discharge from the draining tract, lymphadenomegaly, and cutaneous and subcutaneous nodules resolved. In conclusion, this is the first reported case of disseminated coccidioidomycosis to the cervical region of a dog with involvement of the thyroid gland, skeletal muscle, adipose tissue, connective tissue, and secondary esophageal fistula. Coccidioides spp. infections should be considered a differential diagnosis in unusual cases for dogs that live in or have traveled to endemic areas.

Bicavitary eosinophilic effusion in a dog with coccidioidomycosis.

This is a case of coccidioidomycosis in a dog, examined for vomiting and labored breathing. Physical examination and thoracic and abdominal imaging revealed pleural and peritoneal effusions, both of which exhibited neutrophilic inflammation with a substantial eosinophilic component. The dog had positive IgM and IgG coccidioidomycosis titers at initial evaluation. The eosinophilic component of the inflammation was attributed to coccidioidomycosis. The dog underwent approximately 6 months of fluconazole treatment, with both effusions and clinical signs improving after 6 weeks. Three months after cessation of antifungal treatment, the dog developed a mid-diaphyseal lytic and proliferative lesion in the left radius caused by Coccidioides spp. This case illustrates the importance of consideration of coccidioidomycosis when an eosinophilic cavitary effusion is present in dogs that live in or have traveled to endemic regions.

Fibrosarcoma with sarcomatosis and metastasis in a FeLV-negative cat.

A 6-year-old, spayed female, mixed shorthair cat presented to the emergency service at The Ohio State University Veterinary Medical Center for evaluation of hypercalcemia, a right eye mass, and multiple intrathoracic and intra-abdominal masses. Cytologic evaluation of one of the abdominal masses revealed a uniform population of large, anaplastic mesenchymal cells found individually, in loose aggregates, and occasionally associated with pink, extracellular matrix. The cytology was consistent with a malignant mesenchymal neoplasm, with primary consideration given to fibrosarcoma and hemangiosarcoma. The cat was euthanized and histopathology confirmed disseminated fibrosarcoma. Fibrosarcoma comprises 12%-41% of feline cutaneous tumors and affects cats at a mean age of 9.6 years. Three manifestations of fibrosarcoma predominate in cats: spontaneous solitary fibrosarcoma, vaccine-induced/injection site fibrosarcoma, and oncogene-induced (FSV) fibrosarcoma. The history, signalment, and results from diagnostics performed did not support solitary fibrosarcoma or injection-induced sarcoma. Although some criteria fit with virally induced fibrosarcoma, such as age and the presence of multiple fibrosarcomas, the neoplastic population was negative for FeLV IHC. The presence of fibrosarcomas throughout the pleural and peritoneal cavity was most compatible with sarcomatosis and the distant metastasis of an unidentified primary neoplasm. To the authors' knowledge, this is the first reported case of sarcomatosis in a FeLV-negative cat.

Emerging roles of and therapeutic strategies targeting BRD4 in cancer.

The Bromodomain and Extra-terminal (BET) family of proteins were first recognized as important epigenetic regulators in inflammatory processes; however, there is increasing evidence to support the notion that BET proteins also play a critical role in 'reading' chromatin and recruiting chromatin-regulating enzymes to control gene expression in a number of pathologic processes, including cancer. To this end, the mechanisms by which BET proteins regulate chromatin remodeling and promote tumor-associated inflammation have been heavily studied over the past decade. This article to review the biology of BET protein dysfunction in promoting tumor-associated inflammation and cancer progression and the application of small molecule inhibitors that target specific BET proteins, alone or in combination with immunomodulatory agents as a novel therapeutic strategy for cancer patients.

Inferring developmental constraint and constraint release: primordial germ cell determination mechanisms as examples.

Developmental constraint and its converse constraint release are significant concepts in understanding pattern and process in macroevolution. The purpose of this paper is to propose a two-step method for identifying constraints and constraint release. The first step is a phylogenetic optimization procedure to identify which trait/process is primitive and which is derived. The primitive trait is inferred to be the constraint and the convergently derived trait the release. The second criterion uses sister-clade asymmetry. Clades diagnosed by the constraint will have fewer taxa than clades diagnosed by the release. As an example, we use the process of germ cell specification, in which there are three modes of specification. Our results corroborate previous conclusions that the induced mode is the constraint and the predetermined mode is the release and we speculate on the importance of these two processes in terms of robustness and evolvability.

Regulative germ cell specification in axolotl embryos: a primitive trait conserved in the mammalian lineage.

How germ cells are specified in the embryos of animals has been a mystery for decades. Unlike most developmental processes, which are highly conserved, embryos specify germ cells in very different ways. Curiously, in mouse embryos germ cells are specified by extracellular signals; they are not autonomously specified by maternal germ cell determinants (germ plasm), as are the germ cells in most animal model systems. We have developed the axolotl (Ambystoma mexicanum), a salamander, as an experimental system, because classic experiments have shown that the germ cells in this species are induced by extracellular signals in the absence of germ plasm. Here, we provide evidence that the germ cells in axolotls arise from naive mesoderm in response to simple inducing agents. In addition, by analysing the sequences of axolotl germ-cell-specific genes, we provide evidence that mice and urodele amphibians share a common mechanism of germ cell development that is ancestral to tetrapods. Our results imply that germ plasm, as found in species such as frogs and teleosts, is the result of convergent evolution. We discuss the evolutionary implications of our findings.

Evolution of predetermined germ cells in vertebrate embryos: implications for macroevolution.

The germ line is established in animal embryos with the formation of primordial germ cells (PGCs), which give rise to gametes. Therefore, the need to form PGCs can act as a developmental constraint by inhibiting the evolution of embryonic patterning mechanisms that compromise their development. Conversely, events that stabilize the PGCs may liberate these constraints. Two modes of germ cell determination exist in animal embryos: (a) either PGCs are predetermined by the inheritance of germ cell determinants (germ plasm) or (b) PGCs are formed by inducing signals secreted by embryonic tissues (i.e., regulative determination). Surprisingly, among the major extant amphibian lineages, one mechanism is found in urodeles and the other in anurans. In anuran amphibians PGCs are predetermined by germ plasm; in urodele amphibians PGCs are formed by inducing signals. To determine which mechanism is ancestral to the tetrapod lineage and to understand the pattern of inheritance in higher vertebrates, we used a phylogenetic approach to analyze basic morphological processes in both groups and correlated these with mechanisms of germ cell determination. Our results indicate that regulative germ cell determination is a property of embryos retaining ancestral embryological processes, whereas predetermined germ cells are found in embryos with derived morphological traits. These correlations suggest that regulative germ cell formation is an important developmental constraint in vertebrate embryos, acting before the highly conserved pharyngula stage. Moreover, our analysis suggests that germ plasm has evolved independently in several lineages of vertebrate embryos.