Comparison between sex and age class on some physiological, thermal, and hematological indices of the cerrado's marmoset (Callithrix penicillata)*

Safety and immunogenicity of the anti-cocaine vaccine UFMG-VAC-V4N2 in a non-human primate model

A promising strategy for cocaine addiction treatment is the anti-drug vaccine. These vaccines induce the production of anticocaine antibodies, capable of linking to cocaine, and decrease the passage of cocaine throughout the blood-brain barrier, decreasing drug activity in the brain. Our research group developed a new vaccine candidate, the UFMG-V4N2, to treat cocaine use disorders (CUD) using an innovative carrier based on calixarenes. This study assessed the safety and immunogenicity of the anti-cocaine vaccine UFMG-VAC-V4N2 in a non-human primate toxicity study using single and multiple vaccine doses. The UFMG-VAC-V4N2 yielded only mild effects in the injection site and did not influence the general health, feeding behavior, or hematological, renal, hepatic, or metabolic parameters in the vaccinated marmosets. The anti-cocaine vaccine UFMG-VAC-V4N2 presented a favorable safety profile and induced the expected immune response in a non-human primate model of Callithrix penicillata. This preclinical UFMG-VAC-V4N2 study responds to the criteria required by international regulatory agencies contributing to future anticocaine clinical trials of this anti-cocaine vaccine.

Hematology and blood chemistry reference values of free-ranging Callithrix geoffroyi in Urban environment in Espírito Santo state, Brazil

BACKGROUND

The Callithrix geoffroyi are increasingly present in Brazilian urban areas, where they are vulnerable to health problems. The purpose of this study was a description of hematology and nine blood chemistry parameters of free-ranging C. geoffroyi.

METHODS

Thirty individuals were captured in urban-forested settings. The marmosets were anesthetized, venopunctioned, and released shortly after recovery. The analysis was carried on in a veterinary laboratory, using automatic cells counter, staining methods, and an automatic biochemical analyzer.

RESULTS AND CONCLUSIONS

Male and female free-ranging C. geoffroyi have similar hematological and blood chemistry values. The adults presented higher concentrations of erythrocytes (P <.02) and hemoglobin (P <.02) than young marmosets. The platelet concentration was lower (P <.05) in adults comparing to young marmosets. There were not statistically significant differences between young and adult blood chemistry concentrations. This is the first time that are presented hematology and blood biochemistry data on free-ranging C. geoffroyi.

Abdominal ultrasound in Saguinus ursulus

BACKGROUND

The classification of Saguinus ursulus as a new taxon and the vulnerability of this species highlighted the need for data on its specific morphophysiological attributes. This study used ultrasound to determine the typical characteristics of pelvic-abdominal structures and organs.

METHODS

Nine healthy primates of the species S. ursulus were evaluated, through ultrasound tests, to determine the morphometry of the organs of the pelvic-abdominal cavity and the levels of ovarian activity.

RESULTS

Topography, morphology, and biometrics of the organs were described. It was observed that organs of S. ursulus are similar to those of other Neotropical primate species. However, the kidney morphology is different,the left is triangular and the right is elliptical, while the gallbladder is bilobed.

CONCLUSION

Ultrasonography has proven to be efficient and effective for organ evaluation. The ultrasound findings are a first step toward understanding the physiology of a less-known species.

Haematological and biochemical parameters of wild capuchin monkeys in Brasília, Federal District-Brazil

BACKGROUND

Wild capuchin monkeys (Sapajus libidinosus) usually are found in conserved forests near the zoo and the urban areas of Brasília city, Brazil. In this study, some capuchin monkeys were captured using traps, followed by safe biological procedures for their overall health analysis, based on specific haematological and biochemical tests of blood samples.

METHODS

Blood was collected from a total of 17 monkeys for the determination of parameters, namely packed cell volume (PCV), leucocytes, erythrocytes, platelets and triglycerides. Statistical analyses for average values, median, standard deviation and range were performed.

RESULTS

These parameters were set based on the minimum and maximum values obtained from the blood tests. Data are presented in tabulated form.

CONCLUSIONS

Capture procedures were based on animal safety analysis for free-living animals and would help future studies on wild animals. The collected samples used in this study suggested the animals to be apparently healthy in their habitat.

Searching for the Haplorrhine Heterotherm: Field and Laboratory Data of Free-Ranging Tarsiers

The observation of heterothermy in a single suborder (Strepsirrhini) only within the primates is puzzling. Given that the placental-mammal ancestor was likely a heterotherm, we explored the potential for heterothermy in a primate closely related to the Strepsirrhini. Based upon phylogeny, body size and habitat stability since the Late Eocene, we selected western tarsiers (Cephalopachus bancanus) from the island of Borneo. Being the sister clade to Strepsirrhini and basal in Haplorrhini (monkeys and apes), we hypothesized that C. bancanus might have retained the heterothermic capacity observed in several small strepsirrhines. We measured resting metabolic rate, subcutaneous temperature, evaporative water loss and the percentage of heat dissipated through evaporation, at ambient temperatures between 22 and 35°C in fresh-caught wild animals (126.1 ± 2.4 g). We also measured core body temperatures in free-ranging animals. The thermoneutral zone was 25-30°C and the basal metabolic rate was 3.52 ± 0.06 W.kg-1 (0.65 ± 0.01 ml O2.g-1.h-1). There was no evidence of adaptive heterothermy in either the laboratory data or the free-ranging data. Instead, animals appeared to be cold sensitive (Tb ~ 31°C) at the lowest temperatures. We discuss possible reasons for the apparent lack of heterothermy in tarsiers, and identify putative heterotherms within Platyrrhini. We also document our concern for the vulnerability of C. bancanus to future temperature increases associated with global warming.

Effects of acute systemic cocaine administration on the cortisol, ACTH and prolactin levels of black tufted-ear marmosets

The effect of acute systemic cocaine administration on total circulating cortisol, adrenocorticotropin hormone (ACTH) and prolactin levels of nine adult black tufted-ear marmoset monkeys (Callithrix penicillata) was investigated. For each subject, two blood samples were obtained after an i.p. injection of 10 and 20mg/kg of cocaine: one sample was drawn 30-min post-injection, while the second was following a 60-min interval. Blood samples were also obtained 0, 30 and 60 min following a saline injection. The 20 mg/kg dose of cocaine induced a significant decrease in ACTH levels 60 min after being administered. Circulating levels of cortisol, on the other hand, increased significantly 60 min after the 20 mg/kg dose. Prolactin concentrations decreased significantly 30 and 60 min after both doses of cocaine had been administered (10 and 20 mg/kg). Finally, the content of the three hormones analyzed remained constant 0, 30 and 60 min post-saline administrations. Therefore, an acute systemic cocaine challenge alters the basal circulating levels of ACTH, cortisol and prolactin of marmoset monkeys. A distinct response pattern was observed for each hormone analyzed, possibly related to specific negative feedback mechanisms and/or this species glucocorticoid-resistance. The use of this small neotropical primate may thus provide a unique opportunity to investigate cocaine-induced neuroendocrine effects.