Diagnóstico histopatológico de arterioesclerosis en perros (Canis lupusfamiliaris) / Histopathological diagnosis of arteriosclerosis in dogs (Canis lupus familiaris) / Diagnóstico histopatológico de arteriosclerose em cachorros (Canis lupus familiaris)

La arterioesclerosis es el endurecimiento de las arterias debido a cambios en las estructuras histológicas de la pared vascular, como hipertrofia muscular, tejido conectivo, depósito de calcio, lípidos, etc. La ateroesclerosis se caracteriza por la formación de placas fibrosas en la íntima, que a menudo tiene un núcleo central rico en lípidos; esta patología es el tipo más común de arterioesclerosis en la especie humana y, por lo tanto, de gran importancia para su estudio. Algunos autores reportan que la arterioesclerosis es común, pero de poca importancia en animales domésticos; además encasillan al perro (Canis lupus familiaris) como aterorresistente. Sin embargo, en la actualidad son varios los reportes de lesiones vasculares similares a las observadas en humanos, que están relacionadas con la estrecha convivencia en su papel de mascota. Por tanto, la presente investigación se enfoca en la búsqueda y descripción de lesiones histopatológicas concernientes a arterioesclerosis en perros, mediante un estudio retrospectivo de la casuística del Laboratorio de Patología Veterinaria de la Universidad Nacional de Colombia. Después de revisar los informes de necropsia e histopatología, se seleccionaron 52 casos de perros que reportaban uno o varios factores predisponentes para el desarrollo de arterioesclerosis; las láminas histopatológicas fueron inicialmente evaluadas con la tinción de hematoxilina y eosina y se capturaron fotomicrografías de utilidad para futuras investigaciones. En 23 de los 52 casos seleccionados se observaron diferentes características de lesiones relacionadas con esta entidad, como vacuolas translúcidas, paredes de aspecto hialino, proliferación de tejido muscular o conectivo y deposiciones de mineral y pigmentos. Adicionalmente, en algunos casos se utilizó la coloración tricrómica de Masson para confirmar la presencia de tejido conectivo y muscular. Por último, se plantearon hipótesis sobre la posible asociación de diferentes factores (condición corporal, edad, sexo, raza y enfermedad concurrente) con la presentación de lesiones.

Arteriosclerosis means the hardening of the arteries due to changes in the histological structure of the vascular wall, such as muscle hypertrophy, connective tissue, calcium deposit, lipids, etc. Atherosclerosis is characterized by the formation of fibrous intimal plaques which often have a rich lipid core; this disease is the most common type ofArteriosclerosis in humans and, therefore, of great importance for study. Some authors report that Arteriosclerosis is common, but of little importance, in domestic animals; they also describe the dog (Canis lupus familiaris) as athero-resistant; however, at present there are several reports presenting vascular lesions similar to those observed in humans, related to close cohabitation in their role as pets. Therefore, this study focuses on the research and description ofhistopathological lesions related to Arteriosclerosis in dogs, based on a retrospective study of casuistry at the Laboratory of Veterinary Pathology of the Universidad Nacional de Colombia. After reviewing necropsy and histopathology reports, 52 cases of dogs were selected where one or more predisposing factors for the development of Arteriosclerosis were reported; the histopathology slides were initially evaluated through hematoxylin and eosin staining, and photomicrographs were captured for future research. In 23 of the 52 cases different characteristics of injuries related to this disease were observed, such as translucent vacuoles, walls of hyaline appearance, muscle or connective tissue proliferation, and deposition of mineral and pigments. Additionally, in some cases, Masson's trichrome staining was used to confirm the presence of connective and muscle tissue. Finally, hypotheses were formulated about the possible association of different factors (body condition, age, sex, race, and concurrent disease) with the presentation of these injuries.

Arteriosclerose significa endurecimento das artérias devido às mudanças nas estruturas histológicas da parede vascular como: hipertrofia muscular, tecido conectivo, depósito de cálcio, lipídeos, etc. A aterosclerose se caracteriza pela formação de placas fibrosas na íntima que normalmente têm um núcleo central rico em lipídeos; esta patologia é o tipo mais comum de arteriosclerose na espécie humana e, portanto, de grande importância para seu estudo. Alguns autores reportam que a arteriosclerose é comum, porém de pouca importância em animais domésticos e que é rara; além do mais situa o cachorro (Canis lupus familiaris) como resistente a esta; contudo, atualmente são vários os relatórios da apresentação de lesões vasculares similares às observadas em humanos, sendo relacionadas com a estreita convivência em seu papel de mascote. Portanto, a presente pesquisa se enfoca na busca e descrição de lesões histopatológicas concernentes a arteriosclerose em cachorros, mediante um estudo retrospectivo da casuística do Laboratório de Patologia Veterinária da Universidade Nacional da Colômbia. Depois de revisar os relatórios de necropsia e histopatologia se selecionaram 52 casos de cachorros que reportavam um ou vários fatores predisponentes para o desenvolvimento de arteriosclerose; as lâminas histopatológicas foram inicialmente avaliadas com a coloração de hematoxilina e eosina e se capturaram foto micrografias de utilidade para futuras pesquisas. Em 23 dos 52 casos selecionados se observaram diferentes características de lesões relacionadas com esta entidade como: vacúolos translúcidos, paredes de aspecto hialino, proliferação de tecido muscular ou conectivo e deposições de mineral e pigmentos. Adicionalmente, em alguns casos se utilizou a coloração tricrômica de Masson para confirmar a presença de tecido conectivo e muscular. Por último, se abordaram hipóteses sobre a possível associação de diferentes fatores (condição corporal, idade, sexo, raça e doença concomitante) com a apresentação de lesões.

First histopathological study in kidneys of rodents naturally infected with Leptospira pathogenic species from Yucatan, Mexico

OBJECTIVE@#To report the renal histological lesions in synanthropic rodents, Mus musculus and Rattus rattus, naturally infected with Leptospira spp., captured in a rural community in Yucatan, Mexico.@*METHODS@#Kidney samples of synanthropic rodents were collected from a rural community in Yucatan, Mexico. Polymerase chain reaction was used to detect Leptospira spp. infection. Tissue kidney was fixed in 10% buffered formalin, processed according to the usual techniques for paraffin inclusion, cut and stained with hematoxylin and eosin, and examined using a conventional electronic microscope.@*RESULTS@#A total of 187 rodents were captured. Nine individuals (4.8%) were positive for Leptospira spp. in the molecular analysis. All renal lesions observed in the histopathological study had been reported previously for Leptospira spp. infection.@*CONCLUSIONS@#The histopathological lesions are present in the kidneys, plus the results of the polymerase chain reaction confirm that these rodents are true carriers of Leptospira spp.

First histopathological study in kidneys of rodents naturally infected with Leptospira pathogenic species from Yucatan, Mexico

Objective: To report the renal histological lesions in synanthropic rodents, Mus musculus and Rattus rattus, naturally infected with Leptospira spp., captured in a rural community in Yucatan, Mexico. Methods: Kidney samples of synanthropic rodents were collected from a rural community in Yucatan, Mexico. Polymerase chain reaction was used to detect Leptospira spp. infection. Tissue kidney was fixed in 10% buffered formalin, processed according to the usual techniques for paraffin inclusion, cut and stained with hematoxylin and eosin, and examined using a conventional electronic microscope. Results: A total of 187 rodents were captured. Nine individuals (4.8%) were positive for Leptospira spp. in the molecular analysis. All renal lesions observed in the histopathological study had been reported previously for Leptospira spp. infection. Conclusions: The histopathological lesions are present in the kidneys, plus the results of the polymerase chain reaction confirm that these rodents are true carriers of Leptospira spp.

Presencia de lesiones histopatológicas relacionadas con el método de eutanasia / Histopathological lesions related to euthanasia method

Introducción: los métodos experimentales son un valioso instrumento para estudiar los procesos biológicos del hombre. Se hace necesario buscar el método de eutanasia a emplear para obtener las menores variaciones posibles del tejido. Objetivo: identificar la presencia de lesiones histopatológicas relacionadas con el método de eutanasia, en busca del adecuado para realizar el estudio del daño múltiple de órganos. Métodos: se estudiaron ratones Balb/c, del sexo femenino, de 20 ± 2 g, con edad de 12 semanas. Se subdividieron en tres grupos correspondientes a los métodos de tracción y dislocación cervical, de inmersión en nitrógeno líquido durante 7 s y de sobreanestesia con pentobarbital en dosis de 60 mg/kg. La autopsia se realizó inmediatamente in situ, y se obtuvieron fragmentos de varios órganos, fijados en formol al 10 % y procesados para ser incluidos en parafina, cortados y coloreados con hematoxilina/eosina. Resultados: las lesiones encontradas entre focales y parciales en el pulmón fueron aspectos importantes. El edema cerebral se presentó en la dislocación cerebral y en la sobreanestesia. La inmersión en nitrógeno líquido durante 7 s proporcionó muerte instantánea y obtención de fragmento para estudios histopatológicos con el mínimo de alteraciones. Conclusiones: el estudio histopatológico de los diferentes métodos de eutanasia mostró que la inmersión en nitrógeno líquido fue el de menor cambios posmorten, por lo que es adecuado para emplear en estudios donde se requiera evaluar cambios histopatológicos desde los cambios leves de lesión en los diferentes órganos. Por eso, es recomendable para estudios de la respuesta inflamatoria sistémica en modelos experimentales.

Introduction: experimental methods are valuable tools for studying human biological processes. It is necessary to find the proper method of euthanasia to be used for obtaining the lowest possible variations of tissue. Objective: to identify the presence of histopathological lesions related to euthanasia method, in the search of suitable one for the study of multiple organ failure. Methods: BALB/c, female mice weighing 20 ± 2 g, aged 12 weeks. They were included into three groups corresponding to the methods of traction and cervical dislocation, immersion in liquid nitrogen for 7 s and over anesthesia with pentobarbital 60 mg/kg. Autopsy was performed immediately on the spot, and fragments of various organs were obtained, fixed in 10% formalin. These fragments were processed for inclusion in paraffin, sectioned and stained with hematoxylin/eosin. Results: lesions found in the lung between focal and partial were important aspects. Cerebral edema occurred in brain dislocation and over anesthesia groups. Immersion in liquid nitrogen for 7 s afforded instantaneous death nod obtaining fragment for histopathological studies with minimum alterations. Conclusions: the histopathological examination of the various methods of euthanasia showed that immersion in liquid nitrogen had lower postmortem changes, making its use suitable in studies which require assessing histopathological changes from slight changes in different organs lesions. It is therefore advisable for studies of systemic inflammatory response in experimental models.