Comparative morphofunctional analysis of axial skeleton excluding the skull of primates based on the anatomical, radiographic, and tomographic description of the black-striped capuchin (Sapajus libidinosus Spix, 1823).

Comparative anatomy the basis for studies of evolution, and radiographic and tomographic aspects, as auxiliary methods in the investigation of anatomical particularities, reinforce evolutionary research. Therefore, the aim of this study was to describe the vertebrae, sternum, and ribs of the capuchin monkey (Sapajus libidinosus) by means of anatomical dissection and radiographic and tomographic images. To this purpose, four cadavers were used in the anatomical analysis and five living animals for the imaging exams. The bones were described and compared with data from other primates species found in literature. Student's t-test for independent samples was performed. The vertebral column of the comprises seven cervical, 13 or 14 thoracic, five or six lumbar, two or three sacral, and 23 or 24 caudal vertebrae. The atlas is characterized by three foramina on the wing. The seventh cervical vertebra had a transverse foramen in one specimen. The anticlinal vertebra is always the penultimate thoracic one, the ninth pair of ribs is always the last sternal pair, and the last two are buoyant. The sternal was composed of five or six sternebrae. The lumbar vertebrae showed a bifurcated spinous process. Three different sacral morphologies were observed. The structures identified macroscopically could be well determined through radiographic and tomographic images. S. libidinosus presented anatomical characteristics more similar to those of man and of platirrinos monkeys. The knowledge obtained by macroscopic anatomy and tomographic and radiological exams contributes significantly to comparative evolutionary studies.

Osteology applied to image diagnosis of the forelimb of the black-striped capuchin (Sapajus libidinosus Spix, 1823).

Macroscopic bone analysis and evaluation through imaging methods are essential in the recognition of natural and altered structures. Therefore, this study aimed at describing the osteology the thoracic limb of Sapajus libidinosus in bone pieces, identifying them in radiographic and tomographic images. For this, four cadavers were used in the macroscopic analysis and five animals for the imaging exams, of which four were euthanized and added to the macroscopic stage. For imaging exams, the animals were kept anesthetized. All bones were documented, structures described, and compared with literature data from human and nonhuman primates. There was no statistical difference between males and females regarding the length of the forelimb bones. Most of the bone structures of the scapula were well identified in the imaging methods, being more restricted in the ventrodorsal projection. The clavicle presented very limited visualization. The humerus, as well as the radius and ulna, were not well portrayed in their proximal and distal epiphyses by radiography. However, they were well identified on tomography. All structures described in the macroscopic image of the carpal and metacarpal bones could be identified through radiography and tomography, and the radiographic examination of this region is an excellent method for identifying fractures. The glenoid notch of the scapula was not visualized by any imaging method. S. libidinosus presented anatomical characteristics more similar to those of neotropical primates and man, being a great indicator of an experimental model for studies in these species.

Anatomy applied to image diagnosis of the hind limb in the black-striped capuchin (Sapajus libidinosus Spix, 1823).

The knowledge of anatomy and imaging exams emerges as an important tool in the study of evolutionary processes of a species, in the elaboration of diagnosis, and the successful choice of the appropriate clinical and surgical procedures. Therefore, this study aims to describe the osteology of the hind limb of Sapajus libidinosus by means of gross, radiographic, and tomographic images. Four cadavers were used in the macroscopic analysis and five animals for the imaging exams, of which four were eventually euthanized and added to the macroscopic study. For imaging exams, they were kept anesthetized. All bones of the hind limb were documented, their structures were described, and compared with data in the literature from human and nonhuman primates. We have performed Student's t test for independent samples. There was no statistical difference between the sexes regarding the length of the hind limb bones. The coxal bone was largely well described using imaging methods. A small penile bone was present at the tip of the penis and it could be identified by all analysis methods. The femur, as well as the tibia and fibula, were not well portrayed in their proximal and distal epiphyses by radiography (Rx). However, they were well identified on tomography. No third trochanter was observed in the femur and the patella had a triangular shape. All the structures described by gross anatomy of the tarsus and metatarsus could be identified by Rx and tomography. More subtle structures, such as the popliteal notch on the tibia, and the gluteal tuberosity pectineal line and facies aspera on the coxal bone, were not identified by medical imaging. S. libidinosus presented anatomical characteristics that were similar to those of larger New World and Old World monkeys, including man. This suggests it's value as an experimental model for studies in recent primates.

A New Species of Pachysentis Meyer, 1931 (Acanthocephala: Oligacanthorhynchidae) in the Brown-Nosed Coati Nasua nasua (Carnivora: Procyonidae) from Brazil, with Notes on the Genus and a Key to Species.

INTRODUCTION: Pachysentis comprises 10 species, which have been reported parasitizing mammals in Africa and the American continent. However, species of Pachysentis have not been described in brow-nosed coatis. Pachysentis lauroi n. sp. (Oligacanthorhynchidae: Acanthocephala) is described from the brown-nosed coati Nasua nasua (Linnaeus, 1766) Storr, 1780 (Procyonidae: Carnivora) in the Brazilian Pantanal wetlands of the Mato Grosso do Sul State, Brazil. METHODS: Specimens were studied using light and scanning electron microscopy. RESULT: The new species is distinguished from other species of Pachysentis by the number of hooks in each longitudinal row (12 rows of 4 hooks, total of 48 hooks), presence of barbs on all hooks, and the organization of the cement glands. Notes on the genus Pachysentis [14] and a key to its species are provided. Critical comments on some species with a dubious diagnosis and questionable or missed key taxonomic characteristics are also reviewed. We also discuss the zoogeography of the members of the genus.

Electrocardiographic parameters of Sapajus libidinosus (SPIX, 1823) after chemical immobilization with tiletamine-zolazepam.

BACKGROUND: Tiletamine-zolazepam is a widely used as an alternative chemical immobilization method in non-human primates, with a safe application pathway and necessary relaxation. In order to determine the electrocardiographic parameters of Sapajus libidinosus after intramuscular tiletamine-zolazepam administration at the dose of 5 mg/kg, nine animals were submitted to anesthesia. METHODS: The interpretation of the electrocardiogram determined: heart rate in bpm and heart rhythm, P wave, P-R interval, R wave, QRS complex, T wave, Q-T interval, corrected QT interval and electrical axis. The mean HR was 206 ± 32 bpm. RESULTS: The majority of the monkeys showed normal sinus rhythm, but one animal showed sinus tachycardia. The most commonly observed electrical axis was between +30° and +90°. Two animals presented bigger alterations in the tracing such as low amplitude QRS and T wave bigger than 1/4 of the R wave. CONCLUSIONS: The administration of tiletamine-zolazepam was safe and efficacious, with minimal cardiovascular effects.

Ovary and vaginal epithelium dynamics during the estrous cycle in Dasyprocta prymnolopha Wagler, 1831: ultrasound and cytological examinations.

The objective of the present study was to monitor and characterize morphological alterations in ovaries of agouti (Dasyprocta prymnolopha), reared in captivity, by using abdominal ultrasonography. All animals underwent daily vaginal cytological examination to identify the current cycle phase. For each phase of the estrous cycle, ultrasound examinations were carried out to identify and describe the morphology of both ovaries. Topographic parameters in an ultrasound window were established to locate the ovaries. The agouti estrous cycle lasted an average of 29.94 ± 6.77 days. During vaginal cytology examinations, all cell types were identified, and each phase of the estrous cycle was established by cell counts. No significant alterations were observed in the assessed ovarian morphometry measurements. In 75% of the animals examined, ovarian follicle presence was observed in the proestrus phase.

Comparative pattern of growth and development of Echinostoma paraensei (Digenea: Echinostomatidae) in hamster and Wistar rat using light and confocal laser scanning microscopy.

Echinostoma paraensei (Digenea: Echinostomatidae) lives in the duodenum and bile duct of rodents and is reported as a useful model for studies on the biology of flatworms. Here, we compared the growth and development of pre and post ovigerous worms collected 3, 7, 14 and 21 days post infection from experimentally infected hamster (permissive host) and Wistar rat (less permissive hosts). Linear measurements and ratios were examined by light (morphology and morphometry) and confocal laser scanning microscopy. At day 3, either worm from hamsters or rats were small with poorly developed gonads. At seven day, worms increased in size and morphometric differences between hosts are statistically significant after this time. In addition, adult worms (14 and 21 days of age) harvested from hamster showed developed gonads and vitelline glands laterally distributed on the body, whereas worms from rat showed atrophied reproductive system characterized by underdeveloped vitelline glands and stunted ovary. The worm rate recovery in rat decreased from 29.3% (day 7) to 20.6% (day 14) and 8% (day 21), whilst it remained around 37% in hamster. In conclusion, this is the first appointment demonstrating that low permissiveness influences the reproductive system of echinostome since the immature stages of development. The phenotypic analysis evidenced that hamster provides a more favorable microenvironment for gonads development than rat, confirming golden hamster as a permissive host, whereas Wistar rat is less permissive host.

Light and scanning electron microscopy study of in vitro effects of artesunate in newly excysted metacercariae of Echinostoma paraensei (Trematoda: Digenea).

Chemotherapy of food-borne trematodes relies on two drugs, praziquantel and tricabendazole, and there is growing interest in finding alternative therapies. Plant oil extracts have long been used in traditional Chinese medicine as sources of bioactive compounds with antiparasitic activity. Species of the genus Echinostoma are used as good models to test effective compounds against food-borne trematodes. This study evaluated the anthelmintic activity of crude artesunate extracts in vitro on newly excysted metacercariae of Echinostoma paraensei by light and scanning electron microscopy (SEM). The flukes were incubated with 1 µg/mL, 10 µg/mL, 25 µg/mL, 50 µg/mL and 100 µg/mL of artesunate for 4, 12, 24, 48 and 72 h. When the exposure time and concentration of artesunate increased, there were changes in motor activity, tegument damage and death. Blebs and swelling were the most common damages quantified on the tegument. The in vitro study reproduced results described for other immature flukes incubated with artemisinin derivatives. Excysted metacercariae of E. paraensei constitute a good model to study in vitro drug effects.

A new acanthocephalan species (Archiacanthocephala: Oligacanthorhynchidae) from the crab-eating fox (Cerdocyon thous ) in the Brazilian pantanal wetlands.

A new species of Oligacanthorhynchidae (Acanthocephala) Prosthenorchis cerdocyonis n. sp. is described from 17 specimens collected from the small intestine of the crab-eating fox Cerdocyon thous Linnaeus, 1766 (Canidae: Carnivora) found in the Brazilian Pantanal wetlands. Specimens were studied using light and scanning electron microscopy. Characteristic features distinguishing the new species from others already described are presented, such as size of the body, the position of lemnisci, size of the eggs, host, and geographical distribution. Details of the body surface obtained by scanning electron microscopy, such as the presence of 2 lateral papillae in the proximal region of the proboscis, the presence of barbs in hooks, and a robust and festooned collar, helped to identify the species. Until now, specimens belonging to Prosthenorchis reported from Cerdocyon thous were not identified to species. Furthermore, the new species is the first to be recorded in C. thous found in the Pantanal wetlands.

Development of the reproductive system of Echinostoma paraensei in Mesocricetus auratus analyzed by light and confocal scanning laser microscopy.

This study was performed to gain insight into the maturation of the reproductive system of Echinostoma paraensei worms grown in an early infection of Mesocricetus auratus. Hamsters were infected with 100 metacercariae and necropsied on days 3, 5, 7, 10 and 14 post infection (dpi). Recovered flukes stained with hydrochloric carmine were preserved as whole mounts and analyzed by light and confocal scanning laser microscopy. The average worm recovery was 43.7 per host. Images of the male and female reproductive systems were taken. The ovary and anterior and posterior testis were evidenced on day 3, while the ootype and cirrus sac were present on day 5. Confocal imaging showed primordium testis and ovary as a cluster of primordial cells from day 3 onward. The testes, ovary, cirrus sac and uterus organs were already present during the first week of life. The two testes were seen as individual structures on 7 dpi while the cirrus sac and vitelline glands were in development. The ovary was connected to the uterus while the ootype was adjacent to it. Both testes were larger than the ovary, showing cells at different stages of development, but with few bundles of functional spermatozoa in 10 day-old worms. On day 14, eggs and spermatozoa were seen in the uterus and seminal vesicle, respectively, while oocytes appeared in the ootype as fertilized eggs. We conclude that the reproductive system of E. paraensei was functional on 14 dpi in the hamsters.

A new heligmonellid species (Nematoda) from Oligoryzomys nigripes (Rodentia: Sigmodontinae) in the Atlantic Forest, Brazil.

Stilestrongylus lanfrediae n. sp. is described from the small intestine of Oligoryzomys nigripes (Cricetidae: Sigmodontinae) collected in the Atlantic Forest (Rio de Janeiro State, Teresópolis, Brazil). The new species shows some similarities to Stilestrongylus stilesi, Stilestrongylus freitasi, Stilestrongylus inexpectatus, Stilestrongylus moreli, and Stilestrongylus andalgala, but it can be distinguished from these species by the following combination of characters: 26 ridges in males and 25 in females at the mid-body, asymmetrical caudal bursa with a pattern of type 2-2-1, rays 6 markedly shorter than other lateral rays, rays 8 inserted asymmetrically on dorsal trunk and shorter than other species, and a proportion of spicule length in relation to body length (SpL/BL) of 25-29%. The new species is also distinguished from other species of Stilestrongylus by the asymmetry of the branches of the dorsal ray and by having the longest spicules.

A new metastrongilid species (Nematoda: Metastrongylidae): a lungworm from Akodon montensis (Rodentia: Sigmodontinae) in Brazil.

Angiostrongylus lenzii n. sp. (Nematoda: Metastrongyloidea) is described and illustrated from the pulmonary artery of the wild rodent Akodon montensis Thomas, 1913, collected in the municipality of Teresopólis, Rio de Janeiro State, Brazil. It represents the 17th species of the genus and the 2nd in South America as parasites in rodents. This new species is the most similar morphologically to Angiostrongylus vasorum, Angiostrongylus gubernaculatus, Angiostrongylus schmidti, and Angiostrongylus morerai. It can be distinguished from them by the morphology of the caudal bursa, ventral rays 2 and 3 with conspicuous knobs, differences in width and length of lateral and dorsal rays, presence of rays 8, and length of spicules.