Morphological Characterization of Diaphragm in Common Squirrel Monkey (Saimiri sciureus)

ABSTRACT The wall of the diaphragm can be affected by congenital or acquired alterations which allow the passage of viscera between the abdominal and chest cavities, allowing the formation of a diaphragmatic hernia. We characterized morphology and performed biometrics of the diaphragm in the common squirrel monkey Saimiri sciureus. After fixation, muscle fragments were collected and processed for optical microscopy. In this species the diaphragm muscle is attached to the lung by phrenopericardial ligament. It is also connected to the liver via the coronary and falciform ligaments. The muscle is composed of three segments in total: 1) sternal; 2) costal, and 3) a segment consisting of right and left diaphragmatic pillars. The anatomical structures analyzed were similar to those reported for other mammals. Histological analysis revealed stable, organized muscle fibers with alternation of light and dark streaks, indicating transverse striation.

Frequency of histopathological changes in Howler monkeys ( Alouatta sp. ) naturally infected with yellow fever virus in Brazil

Abstract: INTRODUCTION: Due to the importance that Howler monkeys have on the yellow fever (YF) epidemiological sylvatic cycle in Brazil, more accurate morphological diagnostic criteria needs to be established, especially considering the differences that may exist between the genera of Brazilian non-human primates (NHPs) involved in yellow fever virus (YFV) epizootics. METHODS: Records of YF epizootics in NHPs in Brazil between 2007 and 2009 were obtained from the Brazilian Ministry of Health database to select YF positive (n=98) Howler monkeys (Alouatta sp.) for this study. The changes described in the histopathological reports were categorized by organ and their frequencies calculated. RESULTS: The most frequent lesions observed in the animals with YF were hepatocyte apoptosis (Councilman body formation), midzonal hepatocyte necrosis, steatosis, liver hemorrhage, inflammatory mononuclear cell infiltration of the liver, renal acute tubular necrosis and interstitial nephritis. Midzonal hepatocyte necrosis, steatosis and hemorrhage presented positive correlations with apoptosis of hepatocytes, suggesting strong YFV pathogenic effect association; they were also the main histopathological changes in the Alouatta sp. A pronounced negative correlation between apoptosis of hepatocytes and hepatic mononuclear cell infiltration pointed to significant histopathological differences between YFV infection in Howler monkeys and humans. CONCLUSIONS: The results warn that NHPs may exhibit different response patterns following YFV infection and require a more careful diagnosis. Presumptive diagnosis based on primate histopathological lesions may contribute to public health service control.

Histopathologic findings of pulmonary acariasis in a rhesus monkeys breeding unit / Aspectos histopatológicos da acaríase pulmonar em uma criação de macacos rhesus

Histological lesions in the lungs of rhesus monkeys (Macaca mulatta) related with Pneumonyssus simicola were evidenced. The most prominent pathologic alterations included numerous thin-walled cysts 1-5 mm diameter scattered throughout the lungs, bronchiolitis, peribronchiolitis where the mites were found associated with pigmented and non-pigmented materials. Our study included data from 347 rhesus monkeys submitted to necropsies during 20 years. Four adult debilitated animals were found with pulmonary acariasis which showed a very low incidence of parasite (1.2 percent) in the colony. Most of the published literature described as common and widespread pulmonary acariasis in Old World monkeys. The present study confirms the ubiquity of P. simicola in captive born and raised rhesus monkeys that would compromise experimental studies involving the respiratory system.

Foram evidenciadas lesões histológicas nos pulmões de macacos rhesus (Macaca mulatta) relacionadas ao Pneumonyssus simicola. As principais alterações incluíram numerosos cistos variando de 1-5 mm de diâmetro, com paredes finas e amplamente distribuídos nos pulmões; bronquiolite e peribronquiolite, onde os ácaros foram encontrados associados com materiais particulados pigmentados ou não. Nosso estudo incluiu dados de 347 macacos rhesus submetidos a necropsias no decorrer de 20 anos. A acaríase pulmonar foi diagnosticada em quatro animais adultos debilitados, o que representou uma incidência muito baixa do parasita (1,2 por cento) na colônia. A literatura descreve uma alta incidência de acaríase pulmonar em macacos do Velho Mundo. O presente estudo confirma a ubiqüidade do P. simicola em macacos rhesus nascidos e manejados em cativeiro, que compromete sua utilização em estudos experimentais envolvendo o sistema respiratório.

Morphometric and ultrastructural analysis of different pituitary cell populations in undernourished monkeys

Undernutrition elicited by a low-protein diet determines a marked reduction of hypophyseal activity and affects the function of the respective target organs. The objective of the present investigation was to study the ultrastructural and quantitative immunohistochemical changes of the different pituitary cell populations in undernourished monkeys that had been previously shown to have significant changes in craniofacial growth. Twenty Saimiri sciureus boliviensis monkeys of both sexes were used. The animals were born in captivity and were separated into two groups at one year of age, i.e., control and undernourished animals. The monkeys were fed ad libitum a 20 percent (control group) and a 10 percent (experimental group) protein diet for two years. Pituitaries were processed for light and electron microscopy. The former was immunolabeled with anti-GH, -PRL, -LH, -FSH, -ACTH, and -TSH sera. Volume density and cell density were measured using an image analyzer. Quantitative immunohistochemistry revealed a decrease in these parameters with regard to somatotrophs, lactotrophs, gonadotrophs and thyrotrophs from undernourished animals compared to control ones. In these populations, the ultrastructural study showed changes suggesting compensatory hyperfunction. On the contrary, no significant changes were found in the morphometric parameters or the ultrastructure of the corticotroph population. We conclude that in undernourished monkeys the somatotroph, lactotroph, gonadotroph, and thyrotroph cell populations showed quantitative immunohistochemical changes that can be correlated with ultrastructural findings

Infecçäo experimental de macacos Cebus apella sp pelo Trypanosoma cruzi: avaliaçäo clínica, eletrocardiográfica e anatomopatológica / The experimental infection of Cebus apella sp by Trypanosoma cruzi: its clinical electrocardiography and anatomopathological assessment

Dos trinta e dois macacos capturados no interior do Estado de Säo Paulo e mantidos em laboratório em gaiolas individuais (24 a 25 Cº e 70 por cento de umidificaçäo) após vários xenodiagnósticos negativos, 12 foram infectados por via intraperitoneal com diferentes cepas de Trypanosoma cruzi, cujas formas tripomastigotas injetadas variaram de 1.10**5 a 5.10**6. Os 20 macacos restantes foram mantidos como controle. No período de 1 a 6 anos tanto animais inoculados como os näo inoculados, foram submetidos a xenodiagnóstico e teste sorológico de aglutinaçäo direta, exame clínico e o eletrocardiograma. Posteriormente os macacos foram necropsiados e todos os órgäos submetidos a exame macro e microscópico. O exame clínicos e o eletrocardiograma näo revelaram alteraçöes. Dos 12 macaços infectados, 4 apresentaram evidências de infecçäo ao exame histopatológico: um com formas amastigotas nos tecidos e 3 com miocardite crônica de grau leve. A parasitemia foi comprovada em 66,66 por cento dos animais na fase aguda e a sorologia em 91,66 por cento na fase crônica. Conclui-se que os macacos Cebus näo expressaram suscepitibilidade ao desenvolvimento das lesöes que caracterizam a fase crônica da doença de Chagas mas poderiam ser usados para manter as cepas de T. cruzi e estudos de pesquisa sorológico a longo termo