Caracterización de la expresión de galectina-3 mediante inmunohistoquímica enlesiones intraepiteliales de glándula mamaria de perras sin evidencia de tumor / Characterization of galectin-3 expression by immunohistochemistry in mammary intraepithelial lesions in bitches without evidence of tumor

RESUMEN Las lesiones intraepiteliales (LIEs) son anormalidades morfológicas locales de los ductos y los lobulillos de la glándula mamaria que incrementan el riesgo de cáncer. Los programas de detección temprana de cáncer de seno han incrementado la identificación de LIEs. En este sentido, en perras se ha propuesto las LIEs como modelo comparativo con humanos. La galectina-3 está involucrada con la progresión del cáncer en mujeres y hembras caninas pero su papel en el comportamiento biológico de las neoplasias es contradictorio según la célula de origen. El objetivo de este trabajo fue caracterizar la expresión de la galectina-3 por medio de inmunohistoquímica en 19 glándulas mamarias (GM) de seis perras sin evidencia de tumor que contenían 50 tipos de LIEs y 7 carcinomas invasivos, teniendo en cuenta el porcentaje de células positivas y la intensidad del color de la inmunoreacción. No hubo inmunomarcación para galectina-3 en las adenosis, las hiperplasias ductales usuales, la hiperplasia lobular atípica, las lesiones de células columnares, los carcinomas complejos o las hiperplasias complejas. Un papiloma/ adenoma con hiperplasia de acinos tuvo inmunomarcación multifocal en 11-50% de las células con moderada intensidad. Dos carcinomas in situ del subtipo lobular (uno de grado histológico nuclear intermedio y el otro de alto grado) tuvieron marcación en 10% de las células, pero uno tuvo intensidad baja y el otro, intensidad moderada. Los hallazgos sugieren que el papel de la galectina-3 es poco importante en la iniciación de las LIEs, pero sugieren que es una proteína de interés en la progresión de estas lesiones que posiblemente interactua en el comportamiento biológico de esta enfermedad.

ABSTRACT Intraepithelial lesions (IELs) are local morphological abnormalities of the ducts and lobules of the mammary gland that increase the risk of cancer. Programs of early detection of breast cancer have improved the identification of IELs. In canines they have been proposed as a comparative model with human IELs. Galectin-3 is involved with cancer progression in women and bitches but its role in the biological behavior of neoplasias is contradictory depending on the source cell. The aim of this study was to characterize by immunohistochemistry the expression of galectin-3 in 19 mammary glands (MG) from 6 canines without clinical signs of tumor, containing 50 types of IELs and seven invasive carcinomas, taking into account the percentage of positive cells and the intensity of color immunoreaction. There wasn't any immunostaining for galectin-3 in the adenosis, in the usual ductal hyperplasias, in the atypical lobular hyperplasia, in the columnar cell lesions, in the complex carcinomas or in the complex hyperplasias. A papilloma/adenoma with acinar hyperplasia had multifocal staining in 11-50% of the cells with moderate intensity. Two in situ lobular carcinomas (ISLC) (one of nuclear intermediate grade and the other of high nuclear grade) had 10% staining cells, but the intensity was moderate in one of them and low in the other. Findings suggest that the role of galectin-3 is unimportant in the initiation of IELs, but also that it is a protein of interest in the progression of the lesions and that it possibly acts in the biological behavior of the disease.

Proposal of a production and management index (PMI) for tilapia farms.

Tilapia is one of the most important species in aquaculture; however, there is no available index to show the performance of a production unit. It is desirable to assess the productivity using indexes, such as the production and management index for shrimps and the European production efficacy factor for broilers. These indexes are based on data production: growth, survival, and feed conversion of a full production cycle. Taking into account these parameters, we propose a production and management index (PMI) for tilapia that is applicable for a specific period of the production cycle. For the construction and validation of the PMI we have used production data from 8,614 monthly records of 2 tilapia farms in Huila Department (Colombia), and because of the complexity of tilapia management, different anomalous situations have been detected and then defined as exceptions. As a result, 419 records were considered extreme values because 1 or more exceptions were met. The value of the PMI varies from 0 (the worst situation) to 3.55, which reflects high variability. We have constructed a PMI for tilapia as the product of 3 elements to obtain a positive value index. Instead of classic parameters, we had to calculate an adapted version of them: the relative average daily growth, the survival (as a complementary value of the estimated monthly mortality), and a feed conversion ratio index. To assess the utility of the PMI, some comparisons were performed using records from black and red tilapia. We observed significant differences depending on tilapia strain (PMI = 1.0248 vs. PMI = 1.1661; < 0.001), age (better values for small fish), and season (PMI = 1.0847 vs. PMI = 1.1011; = 0.026). According to these results, we can conclude that the PMI could be a useful tool for tilapia farmers, despite the complexity of the calculation.

Capsule impairs efficient adherence of Streptococcus agalactiae to intestinal epithelium in tilapias Oreochromis sp.

Streptococcosis caused by Streptococcus agalactiae is one of the most important diseases in the tilapia aquaculture industry. The role of the capsule of Streptococcus agalactiae in adherence to fish surfaces has not been evaluated and the mechanism of capsular regulation during adhesion has not been described. The aim of this study was to evaluate the role of the capsule of S. agalactiae during adhesion to intestinal epithelium of tilapia (Oreochromis sp.) in an ex vivo infection model. We show that the capsule impairs the adhesion of bacteria to host intestinal epithelium. Wild type (WT) strain SaTiBe08-18 (S. agalactiae recovered from tilapia) had reduced adhesion (P < 0.0001) in comparison with its unencapsulated mutant of SaTiBe08-18 (Δcps). When WT was treated with sterile saline solution (pH 5) before infection of intestine explants, the adhesion was reached. The results suggest that the capsule impairs the adhesion of S. agalactiae to tilapia intestine and that the acidic milieu could regulate adherence of encapsulated strains. We found GlcNAc on the surface of adherent Δcps but not over the capsule in WT. This difference could be explained by the GlcNAc composition of Lancefield group B antigen and the peptidoglycan in GBS (Group B Streptococcus) and also may be related with better exposure of glycosylated adhesins in unencapsulated fish GBS. Understanding capsular regulation during adhesion of S. agalactiae may provide new leads to find a successful anti-adherence therapy to prevent streptococcosis in tilapia.

Experimental early pathogenesis of Streptococcus agalactiae infection in red tilapia Oreochromis spp.

Streptococcus agalactiae causes a severe systemic disease in fish, and the routes of entry are still ill-defined. To address this issue, two groups of 33 red tilapia Oreochromis spp. each of 10 g were orally infected with S. agalactiae (n = 30), and by immersion (n = 30), six individuals were control-uninfected fish. Three tilapias were killed at each time point from 30 min to 96 h post-inoculation (pi); controls were killed at 96 h. Samples from most tissues were examined by haematoxylin-eosin (H&E), indirect immunoperoxidase (IPI) and periodic acid-Schiff; only intestine from fish infected by gavage was evaluated by transmission electron microscopy. The results of both experiments suggest that the main entry site of S. agalactiae in tilapia is the gastrointestinal epithelium; mucus seems to play an important defensive role, and environmental conditions may be an important predisposing factor for the infection.

Hibridación in situ para la detección de Streptococcus agalactiae en tejidos de tilapia (Oreochromis sp. ) / In situ hybridization technique for Streptococcus agalactiae detection in tilapia tissues (Oreochromis sp. )

La estreptococosis es uno de los problemas sanitarios más serios en la acuicultura mundial. En Colombia la enfermedad afecta de manera importante las explotaciones de tilapia. Se estandarizó la técnica de hibridación in situ (HIS) en tejidos de tilapia previamente identificados como positivos a la presencia de S. agalactiae por la técnica de inmunoperoxidasa indirecta (IPI) y microbiología. Se obtuvo señal positiva en el interior de los granulomas con una especificidad del 100%. Se logró amplificar significativamente la señal mediante el uso de la tiramida. La HIS en tejidos de tilapia puede ser usada para el diagnóstico y estudios de patogenésis y epidemiológicos con este microorganismo. Se requieren futuras investigaciones para optimizar la marcación de las bacterias libres en los tejidos y evaluar la sensibilidad de la técnica.

Streptococcosis is one of the most important health problems in world aquaculture. In Colombia, the disease affects significantly tilapia farms. The standardization of the HIS technique was achieved in tilapia tissues previously identified as positive for thepresence of S. agalactiae by other techniques as indirect immunoperoxidase technique (IPI) and microbiology. Positive signal was obtained within the granulomas with specificity of 100%. The usefulness of the tiramide about increasing the signal intensity was confirmed. The HIS in tilapia tissues can be used in the diagnosis, pathogenesis and epidemiological studies of the disease. Further research is required to optimize the hybridization of bacteria located free in the tissues and to assess the technique sensitivity.

Pathogenesis of Aeromonas hydrophila strain KJ99 infection and its extracellular products in two species of fish.

The distribution of antigen and pathological changes induced by an experimental infection with Aeromonas hydrophila strain KJ99, and its extracellular products, were studied in two species of fish. The microorganism was disseminated systemically and the haemodynamic and tissue changes were similar to those observed in septicaemia of mammals. Intussusception, degeneration and necrosis of the nervous plexus and muscular layers of the gastrointestinal tract were common findings.

Streptococcosis on a red tilapia, Oreochromis sp., farm: a case study.

A commercial red tilapia farm was diagnosed with Streptococcus agalactiae infection using histopathology, microbiology and immunohistochemistry. One hundred fish were randomly taken from different weight/age groups including broodstock, market fish (larger than 150 g), on-growing fish between 20 and 150 g, juveniles and larvae. Fish were clinically examined, anaesthetised and necropsied. Samples were taken from brain, liver, spleen, eyes and kidney for microbiology. All organs were processed for histopathology and an indirect immunoperoxidase test (IIP). Organs from wild fish and birds found in close proximity to the farm were also sampled for microbiology and IIP. The prevalence of lesions or infection found by IIP, histopathology and microbiology was 16%, 29% and 7% respectively. Clinical disease, lesions or infection were not seen in larvae or juveniles. By contrast, infection and disease were found in fish larger than 20 g, suggesting that the condition was linked to the intensive culture conditions of broodstock, on-growing and market fish. S. agalactiae was not found in wild fish, or in birds, by microbiology and IIP.

Patrones histólogicos de las enfermedades inflamatorias de la piel (parte II) / Histological patterns of inflammatory skin diseases

La dermatopatología es una de las más valiosas ayudas diagnósticas en la enfermedad dermatológica de todas las especies animales. El método de análisis de patrones en la lectura histopatológica ha revolucionado el campo de la dermatohistopatología y ha permitido un mejor acercamiento al diagnóstico final de las dermatopatías. Existen nueve patrones histológicos básicos: dermatitis perivascular superficial, dermatitis perivascular superficial y profunda, dermatitis nodular y difusa, dermatitis vesicular y pustulosa intraepidérmica, dermatitis vesicular y pustular subepidérmica, perifoliculitis, foliculitis y forunculosis, dermatitis fibrosante, vasculitis y paniculitis; a partir de estos patrones se genera una lista de diagnósticos diferenciales que conducen fácilmente al diagnóstico final. Es importante que tanto clínicos como patólogos se familiaricen con el uso de estos patrones en beneficio de la interpretación diagnóstica.

Estructura histológica normal de la piel del perro (estado del arte) / Normal histology structure of dog´s skin (art state)

La piel es uno de los órganos más extensos del cuerpo y cumple múltiples funciones: metabólicas, de termorregulación, sensibilidad y protección; está formada por tres capas: la epidermis, la dermis y la hipodermis; en la dermis se encuentran los anexos: folículos pilosos, glándulas sebáceas y glándulas sudoríparas; dentro de los apéndices se encuentran las uñas. Aunque la arquitectura de la piel en los animales domésticos es muy similar, existen variaciones entre especies y aun dentro de un mismo individuo en cuanto al espesor de la epidermis y la dermis, las clases y la disposición de los folículos pilosos y las estructuras anexas. Teniendo en cuenta que las enfermedades dermatológicas son muy frecuentes en la práctica clínica con pequeños animales, en el presente artículo se revisan los aspectos histológicos normales de la piel del perro para poder comprender los cambios que ocurren en la enfermedad dermatológica en esta especie.

Early damages to lung capillaries in enzootic pneumonia of rabbits.

The present study is part of a series of investigations aimed at characterizing the "enzootic pneumonia" phenomenon in rabbits, both from the clinical-epidemiological and the pathophysiological point of view. All affected rabbits included in this study showed an acute injury to pulmonary microvasculature, similar to changes reported in pulmonary infections caused by Gram-negative bacteria. Similar alterations were not found in the control rabbits. The clinical and morphological findings revealed certain similarities between the Enzootic Pneumonia Syndrome of rabbits and Adult Respiratory Distress Syndrome (ARDS) of man. Therefore, it is suggested that, just as in the human syndrome, heterophils (PMN) are directly involved in the pathogenesis of the process. Many of the similarities noted between the two syndromes would make it possible to postulate the natural disease in rabbits as an eventual animal model suitable for extrapolating data to humans.