Uterine evaluation and gestation diagnosis in owl monkey (Aotus azarai infulatus) using the B mode ultrasound.

BACKGROUND: Gynecological and obstetrical ultrasonography has become an indispensable tool in the routine management, health evaluation and research on captive non-human primates. METHODS: Ultrasound was used to evaluate the uterus and estimate the gestation of owl monkeys. Twelve couples were selected, where five were primiparous and seven multiparous females from the National Primate Center reproductive colony, Ananindeua-PA, Brazil. The procedures were carried out using the GE Logiq 100 MP, equipped with a 7.5 MHz linear probe. RESULTS: The females showed a simple uterus, of elongated shape, regular outline and homogeneous echogenic texture. In the uterine measurements craniocaudal diameter, dorsoventral diameter and uterine volume (UV), significant differences were identified (P < 0.05) between ultrasound examinations of primiparous and multiparous females. The UV showed a positive correlation with the number of births. The gestational sac and the embryonic echo were visible between 28 and 38 days after mating. Between 48 and 68 days after mating, embryonic death was identified in all the gestations. CONCLUSIONS: The chemical (use of tranquilizers) and husbandry factors (capture stress) may be related to the prenatal death. The establishing methods of conditioning the female to the ultrasonographic exam may offer a solution to this problem.

Proechimys guyannensis: an animal model of resistance to epilepsy.

PURPOSE: The potential interest of Proechimys guyannensis (PG), a spiny rat species living in the Amazonian region, as an animal model of anticonvulsant mechanisms, prompted the investigation of the susceptibility of this animal species to different epileptogenic treatments. METHODS: Adult male Wistar and PG animals were submitted to amygdala kindling, the pilocarpine model and the intrahippocampal kainic acid (KA) model. Electrographic, behavioral, and neuropathological changes were compared between Wistar and PG animals. RESULTS: PG animals demonstrated a striking resistance to reaching stage 5 of kindling. Of the 43 PG rats submitted to the kindling process, only three animals reached stage 5. In the pilocarpine and KA models, doses lower than those used in Wistar rats were able to induce status epilepticus (SE) in PG animals. Pilocarpine-induced SE in PG had a shorter duration, rarely exceeding 2 h, in contrast to the 8- to 12- h long SE in the Wistar rat. Of the 61 PG animals injected with pilocarpine, 48 presented with SE and only two presented with some spontaneous seizures after silent periods of 60 and 66 days. KA elicited self-sustained electrographic SE in PG animals, which lasted for 72 h. None of the surviving animals presented with spontaneous seizures in the long-term observation period (up to 120 days). CONCLUSIONS: These findings indicate that the PG animal may have natural endogenous anticonvulsant mechanisms and also may be an animal model that is resistant to epileptogenic treatments.

Amygdala kindling in Proechimys guyannensis rat: an animal model of resistance to epilepsy.

PURPOSE: This study examined the effect of amygdala kindling development in Proechimys guayannensis rat, a common rodent of the Amazon basin. METHODS: Adult male P. guayannensis animals (n = 43) and adult male Wistar rats (n = 14) were submitted to electrical amygdala kindling. RESULTS: From 43 Proechimys rats submitted to the kindling process, only three animals reached stage 5 of kindling. During the kindling development (stages 4-5), these animals had behavioral alterations different from those observed in Wistar rats. A longer time spent in stages 1-3 and 5 and longer afterdischarge duration in stages 1-4 was observed in the Proechimys group compared with the Wistar group. The number of wet-dog shakes also was reduced in the Proechimys group during the kindling process. CONCLUSIONS: These findings suggest natural endogenous inhibitory mechanisms in this animal species.