Morphometry of cryopreserved organs from the gastrointestinal system of squirrel monkeys (Saimiri sciureus, Linnaeus, 1758) for improvement of management.

BACKGROUND: Nonhuman primates (NHPs) are fundamental for countless types of research and their phylogenetic similarities with humans make them valuable biomodels. Saimiri (squirrel monkeys) is the New World simian genus that is most widely used in research; however, little is known about the morphology of the gastrointestinal tract (GIT) of these animals. METHODS: The morphological and topographical aspects of GIT organs from 14 previously frozen carcasses of captive squirrel monkeys (Saimiri sciureus) were described as a means for refining clinical and laboratory diagnoses, with the aim of providing a basis for clinical assessments and animal management. The carcasses were gradually thawed, macroscopically evaluated for their appearance, measured, weighed, photographed, and necropsied. The characteristics of all the GIT organs (main and accessories) were evaluated, with measurement of the dimensions and description of the shape, consistency, and color of each one. RESULTS: The stomach of squirrel monkeys is simple and of non-compartmentalized type and the cecum does not have numerous folds, compared with other species. These characteristics are compatible with omnivorous simian species with no adaptive digestive specialization for the food fermentation process. Significant correlations were found between the weights of the carcass and GIT (p < .05); carcass and tongue (0.83; p < .01); and liver and right salivary gland (0.83; p < .01). It was also observed that the animals showed good body score conformation and GIT organs in good condition, which indicated that their nutritional management had been adequate. Regarding the correlations found among the organs: (i) squirrel monkeys with heavier carcasses had better-developed GIT with greater food storage capacity; (ii) the bigger the animal was, the greater its overall muscle development was, including that of the tongue, which would enable intensification of its feeding activity; and (iii) the measurements of the esophagus, small and large intestines, pancreas, and salivary glands were not sex-dependent in Saimiri sciureus. CONCLUSIONS: Previously cryopreserved carcasses of squirrel monkeys can be used for gastrointestinal system studies, with the potential to make clinical, zootechnical, management, and scientific contributions.

Low Aedes aegypti Vector Competence for Zika Virus from Viremic Rhesus Macaques.

Despite worldwide efforts to understand the transmission dynamics of Zika virus (ZIKV), scanty evaluation has been made on the vector competence of Aedes aegypti fed directly on viremic human and non-human primates (NHPs). We blood-fed Ae. aegypti from two districts in Rio de Janeiro on six ZIKV infected pregnant rhesus macaques at several time points, half of which were treated with Sofosbuvir (SOF). Mosquitoes were analyzed for vector competence after 3, 7 and 14 days of incubation. Although viremia extended up to eight days post monkey inoculation, only mosquitoes fed on the day of the peak of viremia, recorded on day two, became infected. The influence of SOF treatment could not be assessed because the drug was administered just after mosquito feeding on day two. The global infection, dissemination and transmission rates were quite low (4.09%, 1.91% and 0.54%, respectively); no mosquito was infected when viremia was below 1.26 × 105 RNA copies/mL. In conclusion, Ae. aegypti vector competence for ZIKV from macaques is low, likely to be due to low viral load and the short duration of ZIKV viremia in primates suitable for infecting susceptible mosquitoes. If ZIKV infection in human and macaques behaves similarly, transmission of the Zika virus in nature is most strongly affected by vector density.

Detection of Signal Regulatory Protein α in Saimiri sciureus (Squirrel Monkey) by Anti-Human Monoclonal Antibody.

Non-human primates (NHP) are suitable models for studying different aspects of the human system, including pathogenesis and protective immunity to many diseases. However, the lack of specific immunological reagents for neo-tropical monkeys, such as Saimiri sciureus, is still a major factor limiting studies in these models. An alternative strategy to circumvent this obstacle has been the selection of immunological reagents directed to humans, which present cross-reactivity with NHP molecules. In this context and considering the key role of inhibitory immunoreceptors-such as the signal regulatory protein α (SIRPα)-in the regulation of immune responses, in the present study, we attempted to evaluate the ability of anti-human SIRPα monoclonal antibodies to recognize SIRPα in antigen-presenting S. sciureus peripheral blood mononuclear cells (PBMC). As shown by flow cytometry analysis, the profile of anti-SIRPα staining as well as the levels of SIRPα-positive cells in PBMC from S. sciureus were similar to those observed in human PBMC. Furthermore, using anti-SIRPα monoclonal antibody, it was possible to detect a decrease of the SIRPα levels on surface of S. sciureus cells after in vitro stimulation with lipopolysaccharides. Finally, using computed-based analysis, we observed a high degree of conservation of SIRPα across six species of primates and the presence of shared epitopes in the extracellular domain between humans and Saimiri genus that could be targeted by antibodies. In conclusion, we have identified a commercially available anti-human monoclonal antibody that is able to detect SIRPα of S. sciureus monkeys and that, therefore, can facilitate the study of the immunomodulatory role of SIRPα when S. sciureus is used as a model.

Biologia, manejo e medicina de primatas não humanos na pesquisa biomédica / Biology, medicine and management of non-human primates in biomedical research

Contém importantes textos para os pesquisadores envolvidos nos estudos deste tema e preenche um vácuo na literatura de nosso país. A publicação aborda conceitos modernos focados na criação em cativeiro, manejo, biologia, taxonomia, medicina e controle da qualidade dessa espécie animal, que tem contribuído largamente para o desenvolvimento de novas vacinas e pesquisas sobre o tratamento de doenças, auxiliando a aprimorar a qualidade da saúde de nossa população. No que diz respeito a ética, biossegurança, reprodução, genética, controle sanitário e legislação, a publicação também dispõe de teorias e práticas que contemplam a visão que os pesquisadores devem contemplar quamdo houver necessidade - ainda indispensável - do uso de animais em experimentação.

Uso de primatas em experimentação: histórico / Use of primates in experimentation: historical

Faz uma abordagem histórica sobre a participação do primata no desenvolvimento humano. O primata não humano tem participado do desenvolvimento humano há pelo menos cinco mil anos, e pode-se encontrar evidências nos hieróglifos no antigo Egito ou em monumentos de culturas indo-asiáticas. Também é usado como pet, enquanto sua utilização em pesquisas ganhou notoriedade somente no período recente.

Biologia, manejo e medicina de primatas não humanos na pesquisa biomédica / Biology, medicine and management of non-human primates in biomedical research

Contém importantes textos para os pesquisadores envolvidos nos estudos deste tema e preenche um vácuo na literatura de nosso país. A publicação aborda conceitos modernos focados na criação em cativeiro, manejo, biologia, taxonomia, medicina e controle da qualidade dessa espécie animal, que tem contribuído largamente para o desenvolvimento de novas vacinas e pesquisas sobre o tratamento de doenças, auxiliando a aprimorar a qualidade da saúde de nossa população. No que diz respeito a ética, biossegurança, reprodução, genética, controle sanitário e legislação, a publicação também dispõe de teorias e práticas que contemplam a visão que os pesquisadores devem contemplar quamdo houver necessidade - ainda indispensável - do uso de animais em experimentação. (AU)

Uso de primatas em experimentação: histórico / Use of primates in experimentation: historical

Faz uma abordagem histórica sobre a participação do primata no desenvolvimento humano. O primata não humano tem participado do desenvolvimento humano há pelo menos cinco mil anos, e pode-se encontrar evidências nos hieróglifos no antigo Egito ou em monumentos de culturas indo-asiáticas. Também é usado como pet, enquanto sua utilização em pesquisas ganhou notoriedade somente no período recente. (AU)

Frequency of the major histocompatibility complex Mamu-A*01 allele in a closed breeding colony of rhesus monkey (Macaca mulatta) from Brazil.

BACKGROUND: Rhesus monkeys are relevant models for human diseases. The simian immunodeficiency virus (SIV) infection is an useful macaque model for assessing human immunodeficiency virus (HIV) vaccine strategies. Susceptibility and resistance to viruses have been associated with particular major histocompatibility complex (MHC) molecules. Several epitopes in the HIV structural and non-structural protein restricted by distinct MHC class I haplotypes are important targets for human cytotoxic T lymphocytes, which mediate protection against SIVmac infection. Mamu-A*01, for example, is a MHC class I molecule of rhesus monkeys that presents a peptide from SIV gag protein. METHODS: Our study determined the frequency of Mamu-A*01 in a closed colony of rhesus monkeys from Brazil by polymerase chain reaction. RESULTS: A high frequency of the allele was found in the study colony. CONCLUSION: This colony provides a significant source of A*01-positive animals to investigators.

Toxoplasmosis in squirrel monkeys: histological and immunohistochemical analysis

Necropsy findings in three cases of naturally occurring toxoplasmosis in squirrel monkeys (Saimiri sciureus) obtained as wild catches from the Amazon region were described. Histopathological evaluation of the liver, spleen, kidneys and mesenteric lymph nodes showed multiple foci of inflammation and necrosis. Typical, well-defined morphologic Toxoplasma gondii cysts and free forms of the parasite were found by immunoperoxidase staining within inflammatory infiltrates. The presence of T. gondii in the studied colony could severely influence the results of experiments performed in the animals.

Achados de necropsia em três casos de toxoplasmose ocorridos naturalmente em macacos-de-cheiro (Saimiri sciureus) obtidos de capturas na região Amazônica foram descritos. A avaliação histopatológica do fígado, baço, rins e linfonodos mesentéricos mostrou múltiplos focos de inflamação e necrose. Cistos morfológicos típicos e bem definidos de Toxoplasma gondii e formas livres foram detectados pelo método da imunoperoxidase com infiltrados inflamatórios. A presença de T. gondii na colônia de primatas estudada pode influenciar severamente os resultados de experimentos realizados nos animais.

Circulation of Campylobacter spp. in rhesus monkeys (Macaca mulatta) held in captivity: a longitudinal study.

Campylobacteriosis is an extremely important zoonosis, circulating freely in the environment. In nonhuman primates kept in open facilities and bred for experimental purposes, the presence of Campylobacter spp. could cause severe damage to the production and interfere with the results of scientific research. In this paper, we assessed the circulation of Campylobacter spp. in a colony of clinically healthy rhesus monkeys (Macaca mulatta) destined to research. The analysis was carried out during seven non-consecutive years. Data showed that despite several changes made in animal management along the studied years in order to control this zoonosis, reduction of bacterial charge did not occur. Significant differences among the age groups and sex were observed. Infants showed higher susceptibility than adult animals. In general males were more infected than females. Modifications adopted in the handling techniques need to be reviewed with the intent of improving the production, reducing bacterial infection of the stock and avoiding undesirable cross reactions in the research carried out with these animals. Therefore, this paper alerts professionals that work directly with captive rhesus monkeys about the risks of Campylobacter spp. infection and possible interference on the experimental procedures.

Studies on argyrophilic nucleolar organizer regions (AgNORs) in a spontaneous mammary gland ductal carcinoma of a captive rhesus monkey.

A spontaneous mammary gland ductal carcinoma was diagnosed in a 13-year-old female captive rhesus monkey (Macaca mulatta). The expression of argyrophilic nucleolar organizer regions (AgNORs) was studied to investigate the correlation between the histologic invasiveness and cell proliferation activity assay for predicting the biologic behavior of this tumor type. The results of this study show that the AgNOR size in tumor cells reflect the degree of malignancy when compared with the pattern of peripheral blood lymphocytes of the same individual. This is the first study showing a significant AgNOR feature of a malignant breast tumor in a rhesus monkey and it longs to provide additional diagnostic tool in tumor pathology.

Circulation of Campylobacter spp. in rhesus monkeys (Macaca mulatta) held in captivity: a longitudinal study

Campylobacteriosis is an extremely important zoonosis, circulating freely in the environment. In nonhuman primates kept in open facilities and bred for experimental purposes, the presence of Campylobacter spp. could cause severe damage to the production and interfere with the results of scientific research. In this paper, we assessed the circulation of Campylobacter spp. in a colony of clinically healthy rhesus monkeys (Macaca mulatta) destined to research. The analysis was carried out during seven non-consecutive years. Data showed that despite several changes made in animal management along the studied years in order to control this zoonosis, reduction of bacterial charge did not occur. Significant differences among the age groups and sex were observed. Infants showed higher susceptibility than adult animals. In general males were more infected than females. Modifications adopted in the handling techniques need to be reviewed with the intent of improving the production, reducing bacterial infection of the stock and avoiding undesirable cross reactions in the research carried out with these animals. Therefore, this paper alerts professionals that work directly with captive rhesus monkeys about the risks of Campylobacter spp. infection and possible interference on the experimental procedures.

Identification of fungi microflora in the ear conducts of rhesus macaques (Macaca mulatta) kept in captivity

Inúmeros fatores predisponentes podem acarretar doenças auriculares a partir de uma microbiota saprófita. A identificação da microbiota fúngica poderia auxiliar no diagnóstico e tratamento de micoses que possam se tornar patogênicas mediante um desequilíbrio homeostásico. Este trabalho objetivou identificar a microbiota fúngica saprófita no conduto auditivo médio de macacos rhesus (Macaca mulatta) clinicamente saudáveis, destinados à pesquisa biomédica. Quarenta macacos rhesus foram divididos em dois grupos. O grupo I foi formado por animais adultos, alojados em gaiolas individuais localizadas em containeres especiais de experimentação com temperatura e umidade controladas. O grupo II, originado da colônia de criação, foi formado por animais jovens, mantidos em ambientes livres, sem controle de temperatura e umidade. O cerúmen do conduto auditivo médio dos animais foi coletado através de swabs. A semeadura das amostras foi feita em placas de Petri contendo Agar Sabouraud com cloranfenicol 1 , lacradas com fita adesiva e incubadas à temperatura ambiente. Nos 20 animais do grupo I, foi encontrado o seguinte: Aspergillus (80), Candida (60), Cladosporium (5) e Rhochtorula (5). O grupo II apresentou uma diversidade maior de fungos: Cândida sp. (95), Aspergillus (20), Clachsporium sp. (60), Penicillium sp. (30), Rodotorulla sp., (15), Trychophytum verrucosum (5), Epidermophyton flocosum (5) e Scopulariopsis sp. (5). Estes dados serão úteis nos diagnósticos e tratamentos de otites e sugerem que os fatores climáticos podem ser responsáveis pelo grande número de fungos presentes nos animais do grupo II, que se encontram expostos às condições climáticas naturais.

Biologic data of Macaca mulatta, Macaca fascicularis, and Saimiri sciureus used for research at the Fiocruz primate center.

Physiological parameters of laboratory animals used for biomedical research is crucial for following several experimental procedures. With the intent to establish baseline biologic parameters for non-human primates held in closed colonies, hematological and morphometric data of captive monkeys were determined. Data of clinically healthy rhesus macaques (Macaca mulatta), cynomolgus monkeys (Macaca fascicularis), and squirrel monkeys (Saimiri sciureus) were collected over a period of five years. Animals were separated according to sex and divided into five age groups. Hematological data were compared with those in the literature by Student's t test. Discrepancies with significance levels of 0.1, 1 or 5% were found in the hematological studies. Growth curves showed that the sexual dimorphism of rhesus monkeys appeared at an age of four years. In earlier ages, the differences between sexes could not be distinguished (p < 0.05). Sexual dimorphism in both squirrel monkeys and cynomolgus monkeys occurred at an age of about 32 months. Data presented in this paper could be useful for comparative studies using primates under similar conditions.

Biologic data of Macaca mulatta, Macaca fascicularis, and Saimiri sciureusused for research at the fiocruz primate center

Physiological parameters of laboratory animals used for biomedical research is crucial for following several experimental procedures. With the intent to establish baseline biologic parameters for non-human primates held in closed colonies, hematological and morphometric data of captive monkeys were determined. Data of clinically healthy rhesus macaques (Macaca mulatta), cynomolgus monkeys (Macaca fascicularis), and squirrel monkeys (Saimiri sciureus) were collected over a period of five years. Animals were separated according to sex and divided into five age groups. Hematological data were compared with those in the literature by Student's t test. Discrepancies with significance levels of 0.1, 1 or 5 percent were found in the hematological studies. Growth curves showed that the sexual dimorphism of rhesus monkeys appeared at an age of four years. In earlier ages, the differences between sexes could not be distinguished (p < 0.05). Sexual dimorphism in both squirrel monkeys and cynomolgus monkeys occurred at an age of about 32 months. Data presented in this paper could be useful for comparative studies using primates under similar conditions.

Chronic Chagas' disease in rhesus monkeys (Macaca mulatta): evaluation of parasitemia, serology, electrocardiography, echocardiography, and radiology.

Severe chronic damage to the heart and gastrointestinal tract in patients with Chagas' disease are often observed 10-20 years after the acute phase. The course of long-lasting infection with the Colombian strain of Trypanosoma cruzi was studied in seven rhesus monkeys infected for 15-19 years. Subpatent parasitemia was detected in all studied animals, using hemoculture (two of seven), artificial xenodiagnosis (three of seven), and a polymerase chain reaction PCR (six of six). High titers of specific IgG antibody to T. cruzi persisted throughout the chronic phase of infection. Abnormal electrocardiographic (three of six) and echocardiographic (one of six) patterns detected in the T. cruzi-infected monkeys were possibly related to parasite-triggered myocardial damage. The results suggest that rhesus monkeys experimentally infected with T. cruzi, besides reproducing the acute phase of Chagas' disease, also develop chronic chagasic cardiomyopathy.

Immune response in cattle vaccinated against rabies

In order to determine the best type of rabies vaccine to use as a booster, 78 serological samples from singly vaccinated cattle were analyzed by counterimmunoelectrophoresis technique. The animals were divided into several groups, received the first vaccine dose with modified live virus vaccine (ERA strain) and were revaccinated with inactivated virus or modified live virus vaccines. Boosters were given at 2, 4, 8, 12 and 16 weeks following first vaccination. Results showed high titres in the cases of booster with inactivated vaccine. In all cases, however, detectable antibody titres declined quickly.

Resposta imune produzida por vacinas anti-rábicas em sagüis (Callithrix sp) / Immune response produced by rabies vaccines in marmosets (Callithrix sp)

Visando avaliar a resposta imunológica produzida por vacinas anti-rábicas em primatas nao humanos neotropicais, trinta sagüis (Callithrix sp) foram divididos em cinco grupos de seis indivíduos e submetidos a cinco diferentes esquemas de vacinaçäo anti-rábica, utilizando-se duas vacinas animais distintas existentes no mercado. A primeira produzida em cérebro de camundongos lactentes (Fuenzalida e Palacios), e a segunda, em cultura de células NIL-2. Acompanhamento sorológico pós-vacinal foi realizado periodicamente. Os resultados mostraram que a vacina Fuenzalida e Palacios näo foi eficaz para a proteçäo dos animais, utilizando-se uma única dose ou mesmo com o reforço. Porém, os sagüis apresentaram anticorpos detectáveis, ao adotar-se o esquema semelhante ao de pré-exposiçäo indicado para os seres humanos, e apenas um animal contraiu raiva após o desafio viral. Por outro lado, a vacina produzida em cultura de células NIL-2 produziu elevados títulos de anticorpos em todos os animais imunizados e todos os animais resistiram ao desafio viral