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.

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.