Comparison between total intravenous anesthesia with propofol and intermittent bolus of tiletamine-zolazepam in capuchin monkey (Sapajus apella) / Comparação entre anestesia total intravenosa com propofol e bolus intermitente de tiletamina-zolazepam em macaco-prego (Sapajus apella)

Dissociative anesthesia results in stressful and long recovery periods in monkeys and use of injectable anesthetics in medical research has to be refined. Propofol has promoted more pleasure wake up from anesthesia. The objectives of this study were to investigate the use of intravenous anesthetic propofol, establishing the required infusion rate to maintain surgical anesthetic level and comparing it to tiletamine-zolazepam anesthesia in Sapajus apella. Eight healthy capuchin monkeys, premedicated with midazolam and meperidine, were anesthetized with propofol (PRO) or tiletamine-zolazepam (TZ) during 60 minutes. Propofol was infused continually and rate was titrated to effect and tiletamine-zolazepam was given at 5mg/kg IV bolus initially and repeated at 2.5mg/kg IV bolus as required. Cardiopulmonary parameters, arterial blood gases, cortisol, lactate and quality and times to recovery were determined. Recovery quality was superior in PRO. Ventral recumbency (PRO = 43.0±21.4 vs TZ = 219.3±139.7 min) and normal ambulation (PRO = 93±27.1 vs TZ = 493.7±47.8 min) were faster in PRO (p<0.05). Cardiopulmonary effects did not have marked differences between groups. Median for induction doses of propofol was 5.9mg/kg, varying from 4.7 to 6.7mg/kg, Mean infusion rate was 0.37±0.11mg/kg/min, varying during the one-hour period. In TZ, two animals required three and five extra doses. Compared to tiletamine-zolazepam, minor post-anesthetic adverse events should be expected with propofol anesthesia due to the faster and superior anesthetic recovery. (AU)

A anestesia dissociativa em primatas resulta em recuperação anestésica lenta e estressante, e, portanto, o uso de anestesia injetável em pesquisas médicas precisa ser refinado. Por outro lado, o propofol promove recuperação mais suave. Os objetivos desse estudo foram investigar o uso do anestésico intravenoso propofol, estabelecer a taxa de infusão contínua necessária para manter anestesia cirúrgica, e comparar tal técnica com a dissociativa tiletamina-zolazepam em Sapajus apella. Oito macacos-prego saudáveis foram pré-medicados com midazolam e meperidina, e posteriormente anestesiados com propofol (PRO) ou tiletamina-zolazepam (TZ) durante 60 minutos. O propofol foi administrado em infusão contínua, e a taxa foi titulada ao efeito, já a tiletamina-zolazepam foi administrada em 5mg/kg IV como bolus inicial, e repiques de 2,5mg/kg IV conforme necessário. Os parâmetros cardiopulmonares, hemogasometria arterial, cortisol, e lactato, além da qualidade e duração da recuperação anestésica foram determinados. A qualidade da recuperação anestésica foi superior em PRO. O tempo para atingir decúbito ventral (PRO = 43,0±21,4 vs TZ = 219,3±139,7 min) e ambulação normal (PRO = 93±27,1 vs TZ = 493,7±47,8 min) foram mais rápidos em PRO (p<0,05). As variáveis cardiopulmonares não diferiram entre os grupos. A mediana para dose de indução com propofol foi de 5,9mg/kg, variando de 4,7 a 6,7mg/kg. A taxa de infusão contínua média de propofol foi de 0,37±0,11mg/kg/min, variando ao longo dos 60 minutos. Em TZ, dois animais necessitaram de três e cinco repiques. Comparado à tiletamina-zolazepam, menos efeitos adversos pós-anestésicos devem ser esperados com o propofol, devido à recuperação mais suave e rápida.(AU)

Influência de diferentes protocolos de contenção nosvalores do eletrocardiograma de macacos-da-noite (Aotus azarae infulatus) / Influence of different restraint protocols for the electrocardiogram values of feline night monkeys (Aotus azarae infulatus)

Macacos-da-noite são muito susceptíveis ao estresse e por isso a contenção química ou física deve ser cuidadosamente avaliada antes de qualquer procedimento. Protocolos anestésicos podem alterar alguns parâmetros fisiológicos, sendo o eletrocardiograma (ECG) um exame muito utilizado para avaliação do ritmo e da frequência cardíaca. O objetivo deste estudo foi avaliar a influência de quatro diferentes protocolos de contenção sobre o ECG realizado em Aotus azarae infulatus. Para isso foram utilizados 10 animais, machos, adultos, submetidos à contenção com a associação tiletamina/zolazepam (TZ), isoflurano (ISO), associação cetamina e midazolam (CET) e contenção física (CF). Não foram observadas diferenças nos parâmetros de ondas e complexos obtidos no ECG em todos os grupos testados, no entanto, durante a avaliação do traçado os animais do grupo CF apresentaram uma quantidade maior de alterações. Concluiu-se que os protocolos de contenção utilizados não alteraram os valores do ECG e que não foi possível considerar o grupo CF como controle devido causar mais alterações do que todos os protocolos testados.(AU)

Feline night monkeys are very susceptible to stress and therefore the physical or chemical restraint should be carefully evaluated before any procedure. Anesthetic protocols can alter some physiological parameters, and electrocardiogram (ECG) is a commonly exam used for evaluation of the rhythm and heart rate. The objective of this study was to evaluate the influence of four different protocols of restraining on ECG in Aotus azarae infulatus, in order to identify the best method of restraining in these primates. For that, we used 10 adult feline night monkeys, males, submitted to restraining protocols with the association tiletamine and zolazepam - (TZ), isoflurane (ISO), association ketamine and midazolam (CET) and physical restraint (CF). No differences were observed in the parameters wave and ECG complexes obtained in all groups tested; however, during the evaluation of the trace the animals of group CF showed a greater amount of change. It was concluded that the restraint protocols used did not change the values of the ECG, and it was not possible to consider the CF group as control due to more caused alterations than all other tested protocols.(AU)

Anatomia e histologia do trato urinário do macaco-prego (Sapajus apella) / Anatomy and histology of the urinary tract in the capuchin monkey (Sapajus apella

Sapajus apella é um primata do Novo Mundo de porte médio e com distribuição geográfica desde a América do Sul até a Argentina. São bons modelos para estudo e nos últimos anos vêm sendo amplamente utilizados para este fim. A destruição progressiva do habitat natural desses animais os tem levado a migrarem para outras regiões, tornando-os, assim, mais susceptíveis à caça predatória. A necessidade de preservação das espécies silvestres desperta interesse por um maior conhecimento anatômico e clínico para estes animais. O presente estudo teve como objetivo examinar e descrever os aspectos morfológicos, quanto a anatomia macroscópica e microscópica dos órgãos do sistema urinário de fêmeas da espécie Sapajus apella visando estender o conhecimento anatômico para esta espécie. Foram utilizadas quatro fêmeas, oriundas do Centro Nacional de Primatas de Ananindeua/PA. istema urinário de S. apella apresenta características similares a outros primatas tanto humanos quanto não humanos e aos animais domésticos. Os rins apresentaram aspectos macroscópicos semelhantes aos rins de humanos, mas com a mesma classificação de outros primatas não humanos e alguns animais domésticos. A bexiga assemelhou-se aos animais domésticos e aos primatas de maneira geral, humano e não humano. O mesmo ocorreu quando analisamos estes órgãos histologicamente.

Sapajus apella is a primate of the New World of midsize and with geographical distribution from South America to Argentina. Good models for the study and in recent years have been widely used for this purpose. The progressive destruction of the natural habitat of these animals has led to migrate to other regions, thus making them more susceptible to hunting predator. The need for the preservation of wild species arouses interest by a greater anatomic and clinical knowledge of these animals. The present study was aimed to examine and describe the morphological aspects, as far as the macroscopic and microscopic anatomy of the organs of the urinary system of female Sapajus apella aiming to extend the anatomical knowledge for this species. Four females were used, from the National Center of Primates in Ananindeua - PA. The urinary system of S. apella has similar characteristics to other primates both human and non-human and domestic animals. The kidneys showed macroscopic aspects similar to the kidneys of humans, but with the same classification of other non-human primates and some domestic animals. The bladder was similar to domestic animals and primates in general, human and non-human. The same occurred when we analyze these components histologically.

Splenic architecture disruption and parasite-induced splenocyte activation and anergy in Plasmodium falciparum-infected Saimiri sciureus monkeys.

BACKGROUND: The understanding of the mechanisms of immunity in malaria is crucial for the rational development of interventions such as vaccines. During blood stage infection, the spleen is considered to play critical roles in both immunity and immunopathology of Plasmodium falciparum infections. METHODS: Saimiri sciureus monkeys were inoculated with blood stages of P. falciparum (FUP strain) and spleens removed during acute disease (days 7 and 13 of infection) and during convalescence (15 days after start of chloroquine treatment). Cytokine (IFNγ, TNFα, IL2, IL6, IL10, and IL12) responses of splenocytes stimulated with P. falciparum-parasitized red blood cells were assessed by real-time PCR using specific Saimiri primers, and histological changes were evaluated using haematoxylin-eosin and Giemsa-stained slides. RESULTS: Early during infection (day 7, 1-2% parasitaemia), spleens showed disruption of germinal centre architecture with heavy B-cell activation (centroblasts), and splenocytes showed increased expression of IFNγ, IL6 and IL12 upon in vitro stimuli by P. falciparum-parasitized red blood cells (pRBC). Conversely, 15 days after treatment of blood stage infection with chloroquine, splenocytes showed spontaneous in vitro expression of TNFα, IL2, IL6, IL10, and IL12, but not IFNγ, and stimulation with P. falciparum pRBC blocked the expression of all these cytokines. During the acute phase of infection, splenic disarray with disorganized germinal centres was observed. During convalescence, spleens of the chloroquine-treated animals showed white pulp hyperplasia with extensive lymphocyte activation and persistency of heavily haemozoin-laden macrophages throughout the red pulp. CONCLUSIONS: Inability to eliminate haemozoin is likely involved in the persistent lymphocyte activation and in the anergic responses of Saimiri splenocytes to P. falciparum pRBC, with important negative impact in immune responses and implications for the design of malaria vaccine.

Continuous infusion of propofol or intermittent bolus of tiletamine-zolazepam in squirrel monkeys (Saimiri sciureus).

OBJECTIVE: To investigate an infusion of propofol for anesthesia in comparison to tiletamine-zolazepam anesthesia, evaluating physiological variables and recovery in squirrel monkeys. STUDY DESIGN: Prospective non-blinded randomized study. ANIMALS: Eight healthy squirrel monkeys (Saimiri sciureus), aged 3 years and weighing 0.340-0.695 kg. METHODS: Premedication was intramuscular midazolam (0.5 mg) and meperidine (4 mg). Anesthesia was induced with intravenous (IV) propofol (4 mg kg(-1)  minute(-1) ) and maintained with propofol starting at 0.4 mg kg(-1)  minute(-1) (PRO, n = 4) or IV tiletamine-zolazepam (5 mg kg(-1) ) and maintained with supplementary doses of TZ (TZ, n = 4). Cardiopulmonary variables were measured continuously. Arterial blood gases and lactate concentration were measured at the end of anesthesia. Quality and times of recovery were determined. Repeatedly measured data for significant differences were tested between groups with t-test and within groups by anova. RESULTS: Median time for induction of anesthesia in PRO was 180 seconds. Mean maintenance infusion rate of propofol was 0.43 ± 0.05 mg kg(-1)  minute(-1) , varying during the 1 hour period. One monkey died after administration of TZ; others required 1, 4, or 8 supplemental doses. Cardiopulmonary variables were similar between groups, but hypotension was recorded. Recovery times to ventral recumbency in PRO (32 ± 17 minutes) and TZ (84 ± 11 minutes) and normal ambulation in PRO (58 ± 22 minutes) and TZ (358 ± 109minutes) were significantly different (p < 0.05). Recovery quality was superior in PRO, with less ataxia and fewer unsuccessful attempts to stand. Lactate concentration was not different between treatments. CONCLUSIONS AND CLINICAL RELEVANCE: Cardiopulmonary variables were similar between protocols, aside from the higher incidence of hypotension in PRO, indicating that further studies with a larger number of animals are required. Compared to tiletamine-zolazepam, propofol anesthesia provided faster and superior anesthetic recovery in these animals.

Continuous infusion of propofol or intermittent bolus of tiletamine-zolazepam in feline night monkeys (Aotus infulatus).

BACKGROUND: Although commonly used, dissociative anesthesia results in unsatisfactory and long recovery periods. The intravenous anesthetic propofol seems to be the most advantageous solution. The objectives of this study were to investigate the required infusion rate of propofol to maintain surgical anesthesia and to compare it to tiletamine-zolazepam in Aotus infulatus. METHODS: Eight healthy feline night monkeys were anesthetized with propofol (PRO) or tiletamine-zolazepam (TZ) during 60 minutes. Cardiopulmonary parameters, arterial blood gases and lactate and quality and times to recovery were determined. RESULTS: Mean infusion rate of propofol was 0.53 ± 0.10 mg/kg/minute. Cardiopulmonary effects did not show marked differences between groups. Times for hanging, ventral recumbency, and normal ambulation were lower in PRO. Establishment of desirable anesthetic depth was easier, recovery quality was superior, and lactate levels were lower in PRO. CONCLUSIONS: Compared with tiletamine-zolazepam, minor post-anesthetic adverse events should be expected with propofol anesthesia, as well as faster and better anesthetic recovery.

Anatomy and morphometric aspects of the trachea of Saimiri sciureus Linnaeus, 1758: knowledge for emergency procedures.

The aim of this work is to study the morphological characteristics of the trachea of Saimiri sciureus through quantification and measurement of the cartilaginous rings, providing information to facilitate the election of more appropriate endotracheal tube, laryngeal mask or tracheostomy tube for anesthetic and emergency procedures, as it is a species of Neotropical primates most commonly used as biological models, and little is known about their morphology. Nine animals were investigated, being 4 adults and 5 young acquired from the Centro Nacional de Primatas (National Primate Center - CENP) - Ananindeua - PA, which died from natural causes and then fixed in aqueous buffered formalin 10%. Saimiri sciureus trachea comprises an average of 32.8 incomplete rings and an average length of 3.74 cm in young animals, while in adults it demonstrated an average of 30.25 rings and average length of 3.67 cm. The shape of the light and its proportion varied along the trachea. Endotracheal tube with a diameter the 2.0 - 2.5 mm, laryngeal mask number 1.0 or tracheostomy tube neonatal Shiley number 3.0, can be placed in animals weighing 600 g - 1.2 Kg. Given the great importance of the species studied, which is widely used as a biological model, the detailing on the morphology and morphometry of tracheal animal studies provides new approaches needed in respiratory emergency, as well as, facilitates the development of future anesthetic protocols.

Origem e distribuição do plexo braquial de Saimiri sciureus / Origin and distribution of the brachial plexus of Saimiri sciureus

Os autores descreveram a origem e composição do plexo braquial de quatro Saimiri sciureus, pertencentes ao Centro Nacional de Primatas (Cenp), Ananindeua/PA, os quais foram fixados com formaldeído e dissecados. Os achados revelaram que o plexo braquial desta espécie é constituído por fibras neurais provenientes da união das raízes dorsais e ventrais das vértebras cervicais C4 a C8 e torácica T1, e organizado em quatro troncos. Cada tronco formou um nervo ou um grupo de nervos, cuja origem variou entre os animais; na maioria, foi encontrado o tronco cranial originando o nervo subclávio, o tronco médio-cranial dando origem aos nervos supraescapular, subescapular, parte do radial, e em alguns casos ao nervo axilar, nervo musculocutâneo e ao nervo mediano; o tronco médio-caudal formou parte do nervo radial, e em alguns casos os nervos axilar, nervo musculocutâneo, nervo mediano, nervo toracodorsal, nervo ulnar e nervo cutâneo medial do antebraço, sendo os dois últimos também originados no tronco caudal.

The authors described the origin and composition of the brachial plexus of four Saimiri sciureus, from the National Primate Center (Cenp), Ananindeua/PA, which were fixed with formaldehyde and dissected. Findings revealed that the brachial plexus of this species is composed by nervous fibers from the roots of cervical vertebrae C4 to C8 and thoracic vertebrae T1, and organized into four branchs. Each branch has formed a nerve or a group of nerves, the origin was varied between animals, mostly were found the cranial trunk originate the subclavian nerve; the medium-cranial originate the suprascapular, subscapular, part of radial and in some cases the axillary, musculocutaneous and median nerves; the medium-caudal trunk originate part of radial nerve and in some cases the axillary, musculocutaneous, median, thoracodorsal, ulnar and medial cutaneous of forearm nerves, the last two nerves also originate from the caudal trunk.

Caring about medullary anesthesia in Saimiri sciureus: the conus medullaris topography.

Saimiri sciureus is a New World non-human primate (NHP) that inhabits Brazilian rain forests. Surgical interventions in wild NHPs can be considered common both for experimental studies procedures and corrective procedures for endangered species. Among various anesthetic procedures, the epidural anesthesia or blockades, depending on the surgical procedure, might be considered elective for wild monkeys, mostly based on its safeness, efficiency and non-time consuming characteristics. However its safeness would be limiting because of the spinal cord arrangement. Notwithstanding the available former studies on New World NHP anatomy, the description of the medullar cone of Saimiri sciureus is still scarce. Therefore, we believe that the better understanding the medullar cone of Saimiri sciureus would contribute to improve the applicability of epidural procedures in the species. Vertebrae architecture of Saimiri sciureus was composed by 9 lumbar, 3 sacral and 18 coccygeal vertebrae, and the medullar cone measured about 3.3 cm. We can conclude that the conus medullaris in Saimiri sciureus is situated more caudally in comparison to other species.

Macroscopic aspects of Saimiri sciureus dura mater / Aspectos macroscópicos da dura mater de Saimiri sciureus

Saimiri sciureus is a small New World primate (NHP) commonly called macaco-de-cheiro that inhabits the tropical forests of the Amazon basin. Anatomical features are not well studied in most primates, and the encephalic morphology and related structures are still quite unknown. Comparative anatomy of the meninges in South American primates is still scarce. Dura mater, arachnoid and pia mater are a group of stratified layers that surrounds and promotes protection to the medulla spinalis. This study aimed to shed light on the anatomy of dura mater in Samiri sciureus in order to contribute to the neuroscience in primates. We investigated three young females and two males of S. sciureus. Specimens were fixed through perfusion with a 10 percent formaldehyde aqueous solution. In S. sciureus encephalus few gyrus and circunvolutions, and a very delicate system consisting of eight sinus venosus was found between the dura mater layers. Based on our findings, we can conclude that the Saimiri sciureus dura mater is quite similar to other mammals, however we detected a new sinus venosus formation at the level of parietal bone, named sinus parietalis, what appears to be its first description.

Saimiri sciureus, com nome comum de macaco-de-cheiro, é um pequeno primata do Novo Mundo (PNM) que habita as florestas tropicais da Bacia Amazônica. Os detalhes anatômicos de primatas são pouco conhecidos e a anatomia comparada de animais selvagens da América do Sul é escassa, mais especificamente, sobre as meninges de PNM. Meninges pertencem a um sistema de membrana responsável por envolver e proteger o Sistema Nervoso Central; consiste em três membranas: dura mater, aracnoide e pia mater. Este estudo objetivou a elucidação do comportamento anatômico da dura mater de S. sciureus com o intuito de contribuir para a área de neurociências em primatas. Foram investigados três fêmeas e dois machos jovnes de S. sciureus. Os espécimes de meninges foram fixados por perfusão usando solução aquosa 10 por cento de formaldeído. O encéfalo de S. sciureus demonstrou um número baixo de giros e circunvoluções, e um sistema delicado de oito seios venosos foi verificado entre as camadas da dura mater. Baseados em nossos achados podemos concluir que a dura mater de S. sciureus é similar aos de outros mamíferos, no entanto, apresenta a formação de um novo seio venoso em nível ao osso parietal, sendo denominado de seio parietal. Isto parece ser a primeira descrição deste seio.

Caring about medullary anesthesia in Saimiri sciureus: the conus medullaris topography

Saimiri sciureus is a New World non-human primate (NHP) that inhabits Brazilian rain forests. Surgical interventions in wild NHPs can be considered common both for experimental studies procedures and corrective procedures for endangered species. Among various anesthetic procedures, the epidural anesthesia or blockades, depending on the surgical procedure, might be considered elective for wild monkeys, mostly based on its safeness, efficiency and non-time consuming characteristics. However its safeness would be limiting because of the spinal cord arrangement. Notwithstanding the available former studies on New World NHP anatomy, the description of the medullar cone of Saimiri sciureus is still scarce. Therefore, we believe that the better understanding the medullar cone of Saimiri sciureus would contribute to improve the applicability of epidural procedures in the species. Vertebrae architecture of Saimiri sciureus was composed by 9 lumbar, 3 sacral and 18 coccygeal vertebrae, and the medullar cone measured about 3.3 cm. We can conclude that the conus medullaris in Saimiri sciureus is situated more caudally in comparison to other species.

Saimiri sciureus é um primata não humano do novo mundo (NHP) que habita as florestas úmidas brasileiras. Intervenções cirúrgicas em NHP selvagens podem ser consideradas comuns em estudos experimentais ou procedimentos corretivos para espécies em perigo. Entre os vários procedimentos anestésicos, a anestesia ou bloqueio epidural depende do procedimento cirúrgico a ser realizado, podendo ser considerada eletiva para macacos selvagens baseada na segurança, eficiência e pouco tempo consumido, entretanto sua segurança pode estar limitada devido ao arranjo da medula espinhal. Apesar de existirem estudos anatômicos disponíveis de NHP a descrição do cone medular do Saimiri sciureus permanece escassa. Portanto, nós acreditamos que o melhor entendimento a respeito do cone medular do Saimiri sciureus pode contribuir para melhorar a aplicabilidade de procedimentos epidurais nesta espécie. A arquitetura vertebral do Saimiri sciureus é composta por 9 vértebras lombares, 3 sacrais e 18 coccígeas e o cone medular apresentou tamanho médio de 3,3 cm. Podemos concluir que o cone medular Saimiri sciureus está situado mais caudalmente em comparação com outras espécies.

Immunization of Saimiri sciureus monkeys with a recombinant hybrid protein derived from the Plasmodium falciparum antigen glutamate-rich protein and merozoite surface protein 3 can induce partial protection with Freund and Montanide ISA720 adjuvants.

The immunogenicity and efficacy of a hybrid recombinant protein derived from the N-terminal end of the glutamate-rich protein (GLURP) and the C-terminal portion of the merozoite surface protein 3 (MSP3) of Plasmodium falciparum was evaluated in Saimiri sciureus monkeys. The GLURP/MSP3 hybrid protein, expressed in Lactococcus lactis, was administered in association with alum, Montanide ISA720, or complete or incomplete Freund adjuvant (CFA/IFA) in groups of five animals each. The three formulations were shown to be immunogenic, but the one with alum was shown to be weak compared to the other two, particularly CFA/IFA, which provided very high antibody titers (enzyme-linked immunosorbent assay titers of >3,000,000 and immunofluorescence antibody test titers of 6,400). After a challenge infection with P. falciparum FUP strain, all five monkeys from the GLURP/MSP3-alum group showed a rapid increase in parasitemia, reaching 10% and were treated early. The two monkeys with the highest antibody titers in group GLURP/MSP3-Montanide ISA720 had a delay in the course of parasitemia and were treated late due to a low hematocrit. In the GLURP/MSP3-CFA/IFA group, parasitemia remained below this threshold in four of the five animals and, after it reached a peak, parasitemia started to decrease and monkeys were treated late. When all animals were grouped according to the outcome, a statistically significant association between high antibody titers and partial protection was observed. The challenge infection boosted the antibody titers, and the importance of this event for vaccine efficacy in areas where this parasite is endemic is discussed. In conclusion, these data suggest that GLURP and MSP3 can induce protection against malaria infection if antibodies are induced at properly high titers.

Aotus infulatus monkey is susceptible to Plasmodium falciparum infection and may constitute an alternative experimental model for malaria

Aotus is one of the WHO-recommended primate models for studies in malaria, and several species can be infected with Plasmodium falciparum or P. vivax. Here we describe the successful infection of the species A. infulatus from eastern Amazon with blood stages of P. falciparum. Both intact and splenectomized animals were susceptible to infection; the intact ones were able to keep parasitemias at lower levels for several days, but developed complications such as severe anemia; splenectomized monkeys developed higher parasitemias but no major complications. We conclude that A. infulatus is susceptible to P. falciparum infection and may represent an alternative model for studies in malaria.