Changes in the levels of free sialic acid during ex vivo lung perfusion do not correlate with pulmonary function. Experimental model.

BACKGROUND: Ex vivo lung perfusion (EVLP) constitutes a tool with great research potential due to its advantages over in vivo and in vitro models. Despite its important contribution to lung reconditioning, this technique has the disadvantage of incurring high costs and can induce pulmonary endothelial injury through perfusion and ventilation. The pulmonary endothelium is made up of endothelial glycocalyx (EG), a coating of proteoglycans (PG) on the luminal surface. PGs are glycoproteins linked to terminal sialic acids (Sia) that can affect homeostasis with responses leading to edema formation. This study evaluated the effect of two ex vivo perfusion solutions on lung function and endothelial injury. METHODS: We divided ten landrace swine into two groups and subjected them to EVLP for 120 min: Group I (n = 5) was perfused with Steen® solution, and Group II (n = 5) was perfused with low-potassium dextran-albumin solution. Ventilatory mechanics, histology, gravimetry, and sialic acid concentrations were evaluated. RESULTS: Both groups showed changes in pulmonary vascular resistance and ventilatory mechanics (p < 0.05, Student's t-test). In addition, the lung injury severity score was better in Group I than in Group II (p < 0.05, Mann-Whitney U); and both groups exhibited a significant increase in Sia concentrations in the perfusate (p < 0.05 t-Student) and Sia immunohistochemical expression. CONCLUSIONS: Sia, as a product of EG disruption during EVLP, was found in all samples obtained in the system; however, the changes in its concentration showed no apparent correlation with lung function.

OSTEOSARCOMA IN AFRICAN HEDGEHOGS (ATELERIX ALBIVENTRIS): FIVE CASES.

Osteosarcomas are unusual neoplasms in African hedgehogs ( Atelerix albiventris ) and have been reported in extraskeletal and skeletal locations, including mandible, ribs, and vertebra. Five hedgehogs with osteosarcoma submitted to the Pathology Department at Facultad de Medicina Veterinaria y Zootecnia, National Autonomous University of Mexico are reported. In two cases, the neoplasm arose from the skull; one case arose from the ribs with associated compression of the thoracic and abdominal cavity, and another case involved the vertebrae. In the last case, the neoplasm arose from the scapula. Histologic lesions were similar in all cases and consisted of well-demarcated nodules in which neoplastic cells were arranged in sheets of polyhedral to spindle-shaped cells with interspersed areas of necrosis. Numerous trabeculae of osteoid were present throughout the tumors. No metastases were detected. The predominant histologic pattern was osteoblastic, but a telangiectatic-like pattern was observed in the vertebral osteosarcoma. Electron microscopy was performed in two cases, and malignant osteoblasts had features consistent with descriptions in other species, including deposits of hydroxyapatite in osteoid. According to these cases and previously published data, axial osteosarcomas are more frequent in contrast to appendicular osteosarcomas in African hedgehogs, and metastases are rare.

Prevalence of cutaneous pathological conditions and factors associated with the presence of skin wounds in working equids in tropical regions of Veracruz, Mexico.

A wide spectrum of welfare issues is encountered on working equids. The objectives of this study were: (i) to determine the prevalence of cutaneous lesions in working equids in tropical regions of the North-Central of Veracruz State, Mexico, (ii) to identify the most prevalent cutaneous pathological conditions in this population of working equids, and (iii) to identify risk factors associated to the presence of work-related skin wounds. A number of 467 working equids presented for treatment at Donkey Sanctuary Mobile Clinic Program - National Autonomous University of Mexico from seven different villages in the North-Central region of Veracruz State were evaluated. Animals with signs of cutaneous pathology underwent a physical examination and samples were obtained of exudates, hair, and tissue for cytology examination, fungal cultures, and dermo-histopathology examination. The overall prevalence of cutaneous pathological conditions in working equids was 20.6 %. The prevalence per species was 22.6 % for horses, 18.2 % for donkeys, and 14.3 % for mules. The most common cause of skin lesions was trauma (abrasions, lacerations, and abscesses) followed in frequency by parasitic dermatitis and sarcoids. No strong associations among species were observed (P > 0.20). Multivariate analysis showed that there was greater association between BCS and age with the presence of skin wounds (P < 0.05). Equids who's BCS was rated as "moderate" as well as adult animals showed significantly more skin wounds compared with the young and the elderly (P < 0.05). These findings can help to develop a better management practices to improve the welfare of equids in tropical regions of Veracruz, Mexico.

Rabbit Fibroma Virus infection in domestic rabbits (Oryctolagus cuniculus) in Mexico.

Rabbit Fibroma is a Leporipoxviral disease and is considered the third most common cutaneous neoplasm in pet rabbits. Two domestic rabbits (Oryctolagus cuniculus) were submitted to the veterinary clinic due to the presence of a nodule on the lip. Histologically, epithelial cells of the epidermis and hair follicles showed mild to moderate ballooning degeneration, spongiosis, and several eosinophilic intracytoplasmic inclusion bodies. The dermis was expanded by atypical spindle cells that also showed eosinophilic intracytoplasmic inclusion bodies. The tissues were evaluated by using transmission electron microscopy. In both cases, keratinocytes exhibit several electron dense and pleomorphic intracytoplasmic viral particles consistent with Poxviruses. To our knowledge, this is the first case report of Rabbit Fibroma Virus infection in Domestic Rabbits in Mexico.

Leishmania mexicana: Novel Insights of Immune Modulation through Amastigote Exosomes.

Exosomes are extracellular microvesicles of endosomal origin (multivesicular bodies, MVBs) constitutively released by eukaryotic cells by fusion of MVBs to the plasma membrane. The exosomes from Leishmania parasites contain an array of parasite molecules such as virulence factors and survival messengers, capable of modulating the host immune response and thereby favoring the infection of the host. We here show that exosomes of L. mexicana amastigotes (aExo) contain the virulence proteins gp63 and PP2C. The incubation of aExo with bone marrow-derived macrophages (BMMs) infected with L. mexicana led to their internalization and were found to colocalize with the cellular tetraspanin CD63. Furthermore, aExo inhibited nitric oxide production of infected BMMs, permitting enhanced intracellular parasite survival. Expressions of antigen-presenting (major histocompatibility complex class I, MHC-I, and CD1d) and costimulatory (CD86 and PD-L1) molecules were modulated in a dose-dependent fashion. Whereas MHC-I, CD86 and PD-L1 expressions were diminished by exosomes, CD1d was enhanced. We conclude that aExo of L. mexicana are capable of decreasing microbicidal mechanisms of infected macrophages by inhibiting nitric oxide production, thereby enabling parasite survival. They also hamper the cellular immune response by diminishing MHC-I and CD86 on an important antigen-presenting cell, which potentially interferes with CD8 T cell activation. The enhanced CD1d expression in combination with reduction of PD-L1 on BMMs point to a potential shift of the activation route towards lipid presentations, yet the effectivity of this immune activation is not evident, since in the absence of costimulatory molecules, cellular anergy and tolerance would be expected.

Pathogen Risk Analysis for Wild Amphibian Populations Following the First Report of a Ranavirus Outbreak in Farmed American Bullfrogs (Lithobates catesbeianus) from Northern Mexico.

Ranaviruses are the second deadliest pathogens for amphibian populations throughout the world. Despite their wide distribution in America, these viruses have never been reported in Mexico, the country with the fifth highest amphibian diversity in the world. This paper is the first to address an outbreak of ranavirus in captive American bullfrogs (Lithobates catesbeianus) from Sinaloa, Mexico. The farm experienced high mortality in an undetermined number of juveniles and sub-adult bullfrogs. Affected animals displayed clinical signs and gross lesions such as lethargy, edema, skin ulcers, and hemorrhages consistent with ranavirus infection. The main microscopic lesions included mild renal tubular necrosis and moderate congestion in several organs. Immunohistochemical analyses revealed scant infected hepatocytes and renal tubular epithelial cells. Phylogenetic analysis of five partial ranavirus genes showed that the causative agent clustered within the Frog virus 3 clade. Risk assessment with the Pandora⁺ protocol demonstrated a high risk for the pathogen to affect amphibians from neighboring regions (overall Pandora risk score: 0.619). Given the risk of American bullfrogs escaping and spreading the disease to wild amphibians, efforts should focus on implementing effective containment strategies and surveillance programs for ranavirus at facilities undertaking intensive farming of amphibians.

Toxoplasmosis en una colonia de monos ardilla (Saimiri sciureus) en cautiverio en Cuernavaca, Morelos, México / Toxoplasmosis outbreak in a private collection of squirrel monkeys (Saimiri sciureus) in Cuernavaca, Morelos Mexico

Toxoplasmosis is a disease of worldwide distribution that parasites the intestinal tract of wild and domestic cats. However, in New World monkeys it is considered an acute and fatal illness. The reason for its high susceptibiliy in this particular species is still unknown, but it has been theorized that their habitat and living conditions, in high trees, might be an important factor. Necropsy was performed on 5 squirrel monkeys (Saimiri sciureus), three males (adult) and two females (one of them gravid), with a clinical history of eye redenning and presence of bloody serous foam in the nostrils. Gross examination of the lung showed non collapsed lobes, dark red parenchyma and irregular pale pink nodular areas. All five animals showed apparent hepatomegaly. Histological findings revealed an interstitial pneumonia with a prominent thickening of alveolar septae, and numerous foamy macrophages with intracytoplasmic basophilic structures 20- 25 urn long, covered by a refringent wall and housing PAS positive basophilic structures that were aproximately 8 urn long (bradyzoites), which were identified as protozoal cysts. The liver showed multiple foci of periportal inflammatory cells and numerous parasitic cysts that were also observed in spleen and brain tissue. Inmunohistochemical technique was performed on selected samples of brain, liver and lung tissue, which resulted positive for Toxoplasma gondii using antibodies of hyperimmune antiserum-caprine 6244 origin, in a 1:300 dilution. Samples of the same tissues were processed for transmission electron microscopy. Hepatocytes of the liver showed multiple intracytoplasmic vacuoles with parasitic structures consistent with tachyzoites, which were 3.6 μm long and measured 2.3 μm in diameter. They possesed a slightly wavy electrodense plasmatic membrane that exhibited a conoid in its anterior end, along with several electrodense micronemes. Ultraestructural features like the conoid and the location of micronemes allowed us to identify the parasite as Toxoplasma gondii. Clinical history, necropsy findings, microscopic examination, inmunohistochemical analysis and electron microscopy of all five squirrel monkeys were consistent with a diagnosis of systemic toxoplasmosis. This report shows the high suceptibiliity of New World monkeys to become infected with this parasite. Therefore, toxoplasmosis should be considered among the differential diagnosis for diseases with non specific clinical signs in this particular species.

La toxoplasmosis es una enfermedad de distribución mundial provocada por el protozoario Toxoplasma gondii cuyos huéspedes definitivos son los felinos y una gran diversidad de especies animales son los huéspedes intermediarios. En primates del Nuevo Mundo se caracteriza por ser una enfermedad aguda y de curso fatal. La razón de la alta susceptibilidad en estos animales hasta la fecha se desconoce y generalmente se ha asociado con sus hábitos arborícolas. Se realizó la necropsia de cinco monos ardilla (Saimiri sciureus), tres machos (adultos) y dos hembras (una de ellas gestante), con historia clínica de enrojecimiento de los ojos y salida de espuma serosanguinolenta por la nariz. Macroscópicamente, los cinco animales presentaron los lóbulos pulmonares no colapsados y el parénquima rojo oscuro con áreas rosa claro entremezclado que en ocasiones tenían aspecto nodular. El hígado de los cinco animales se apreció aumentado de tamaño y pálido en su totalidad. Microscópicamente se observó neumonía intersticial caracterizada por el engrosamiento de los septos alveolares y la presencia de numerosos macrófagos espumosos cuyo citoplasma contenía estructuras elongadas, basofílicas de 20-25 μm de diámetro con pared refringente que a su vez albergaban estructuras basofílicas de 8 um (bradizoítos) PAS positivas consistentes con quistes de protozoarios. El hígado presentó focos de infiltrado inflamatorio periportal, así como numerosos quistes de protozoarios, que también se apreciaron en bazo y cerebro. Se realizó inmunohistoquímica de secciones histológicas de pulmón, hígado y cerebro, las cuales fueron positivas para Toxoplasma gondii con el anticuerpo Hyperimmune antiserum-caprine, a una dilución de 1:300. Asimismo, muestras de estos mismos tejidos fueron procesadas para microscopía electrónica de transmisión, en las que el hígado exhibía en su citoplasma vacuolas parasitarias con estructuras correspondientes a taquizoítos que medían de 3.6 μm de largo por 2.3 μm de diámetro, con una membrana plasmática electrodensa, ligeramente ondulada, que en ocasiones exhibían en su extremo anterior el conoide, y por debajo de éste, escasos micronemas electrodensos. Las características ultraestructurales como el conoide, y la ubicación de los micronemas, son criterios primordiales que permiten identificar al parásito como Toxoplasma gondii. La historia clínica, los hallazgos a la necropsia, el estudio histopatológico, la inmunohistoquímica y microscopía electrónica de los cinco monos ardilla fueron consistentes con un cuadro de toxoplasmosis sistémica. Este informe demuestra la alta susceptibilidad que poseen los primates del Nuevo Mundo al ser infectados por este protozoario, por lo que se debe considerar entre los diagnósticos diferenciales para enfermedades de curso clínico no específico en estos animales.

Vulvovaginitis y balanopostitis pustular sugerente a herpesvirus caprino-1 en cabras (Querétaro, México) / Pustular vulvovaginitis and balanoposthitis suggestive of caprine herpesvirus-1 infection in goats (Queretaro, Mexico)

Infectious pustular vulvovaginitis and balanoposthitis in goats is caused by caprine herpesvirus 1 (CpHV-1), from the Herpesviridae family Alphaherpesvirinae subfamily, sometimes produces abortion, neonatal enteritis and respiratory disease in adult goats. In a herd of 244 dairy and meat goats, physical examinations were performed in does and bucks, presenting vulvar and preputial lesions. Necropsies were done in four discarded animals (one male and two females) and one stillborn; immunohistochemistry (IHC) with bovine herpesvirus 1 (BHV-1) antibodies in prepuce and vulva samples was carried out. Penis and prepuce exfoliative cytology was carried out in six bucks. Prepuce biopsies were collected for electron microscopy and viral isolation. Macroscopically, moderate to severe coalescent multifocal pustular and ulcerative vulvovaginitis was observed; and severe coalescent multifocal pustular and ulcerative balanoposthitis. Microscopically, different degrees of inflammatory lesions with presence of eosinophilic and amphophilic intranuclear inclusion bodies were present. In electron microscopy, the prepuce samples and MBDK cell culture showed several intranuclear viral particles of 150 to 230 nm size. There was slight epithelial cell positivity in IHC with BHV-1 antibodies in vulva and prepuce histological cuts made at necropsy. In the viral isolate was observed a cytopathic effect and the presence of viral particles by microscopy electronic suggesting herpes virus. This is the first documented report suggesting the presence of herpes virus outbreak in caprine herds in Mexico.

La vulvovaginitis y balanopostitis pustular infecciosa en cabras es producida por herpesvirus caprino 1 (CpHV-1), de la familia Herpesviridae subfamilia Alphaherpesvirinae, que ocasionalmente produce aborto, enteritis neonatal y enfermedad respiratoria en las cabras adultas. En un rebaño de 244 cabras de genotipo lechero y cárnico; se realizaron exámenes físicos de hembras y sementales en los que se observaron lesiones vulvares y prepuciales. Se realizó la necropsia de cuatro animales adultos de desecho (dos hembras y un macho) y un neonato muerto; se realizó inmunohistoquímica (IHQ) con anticuerpos de herpesvirus bovino 1 (BHV1) en muestras de prepucio y vulva. Se analizaron las citologías exfoliativas de pene y prepucio de 6 sementales. Se recolectaron y analizaron biopsias de prepucio para microscopía electrónica y aislamiento viral. Macroscópicamente, en las hembras se observó vulvovaginitis pustular y ulcerativa de moderada a grave multifocal coalescente, además de balanopostitis pustular y ulcerativa grave multifocal coalescente en los machos. Microscópicamente, se presentaron lesiones inflamatorias en diferentes grados, con presencia de cuerpos de inclusión intranucleares eosinofílicos y amfofílicos. En microscopía electrónica, las muestras de prepucio y cultivo celular de MBDK presentaron numerosas partículas virales intranucleares de un tamaño de 150 a 230 nm. En los cortes histológicos de prepucio y vulva de las necropsias se detectó una ligera positividad en las células epiteliales con anticuerpos BHV-1. En el aislamiento viral se observó efecto citopático, y la presencia de partículas virales mediante microscopía electrónica sugerentes a herpes virus. Este es el primer informe documentado que sugiere la presencia de herpes virus en rebaños caprinos de México.