Publications by authors named "Marcelo Abidu Figueiredo"

Purpose: To histologically quantify the different tissues that make up the porcine ureter, (epithelial, connective, and muscular tissue) in the three segments labelled: cranial, middle and caudal, in order to identify the segment most compatible for use as a vascular graft.

Methods: Fifteen porcine ureters were collected, divided into the three segments, and the samples were stained with hematoxylin and eosin, picrosirius red and Weigert's resorcin-fuchsin. The immunohistochemistry technique was applied for alpha-smooth muscle actin.

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Article Synopsis
  • - Marmosets (Callithrix spp) are small monkeys used in research, but detailed information about their kidney anatomy and blood supply is limited, prompting this study to gather basic anatomical data for future research.
  • - The study involved dissecting 50 marmoset cadavers to analyze kidney size and positioning, finding that female marmosets had larger kidneys, and that the right kidney was typically positioned higher than the left in both sexes.
  • - Results showed a consistent correlation between the body length and kidney length, with kidney locations varying but generally aligning with patterns seen in other primates, indicating anatomical similarities across species.
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Purpose: To test the use of rainbow trout skin as a surgical mesh in abdominal hernioplasties in rats.

Methods: The experiment involved 20 Wistar rats receiving implants of trout skin processed for disinfection in 0.5% glutaraldehyde and preserved in 100% glycerin.

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Background: Analysing the literature about the reproductive anatomy on New World Primates, one can see the need of standardisation on the description methods and, more importantly, the lack of detailed information. The problem is aggravated by the difficult access to specimens of the endangered species such as Brachyteles sp. This paper's objective was to extend knowledge on the male reproductive anatomy of these primates.

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This study aims to investigate the anatomy of coronary arteries and their primary branches in neotropical carnivores, given the functional significance of coronary circulation and the limited existing descriptions in this order. For this purpose, coronary arteries were dissected, and their branches were counted in 74 hearts from 20 species belonging to five families: Canidae, Mustelidae, Procyonidae, Mephitidae, and Felidae. In all specimens of the suborder Caniformia, the subsinuosal interventricular branch originated at the end of the circumflex branch of the left coronary artery (LCA).

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Studies on brain anatomy can clarify specific evolutionary and behavioural aspects of wild animals. The rich diversity in a broad range of habitats makes carnivorans especially eligible for studying the relations between the brain form and behaviour, cognitive, sensorial and motor traits. This study compared the brain's contour and total and segmented brain volumetry in three species of neotropical carnivorans.

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There are few scientific reports on the histology of the phallus of ratite birds. The aim of this study was to conduct a histochemical analysis to determine the distribution of smooth muscle cells and the volumetric density (Vv) of the fibres of the elastic system in the ostrich phallus. Adult ostriches, 14 months old, were used.

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Purpose: Despite the high frequency of hernioplasties worldwide, their complications and recurrences are still a challenge to be overcome. The search for prostheses that aim to promote the correction of hernia defects has been a challenge. For this purpose, the materials used in hernioplasties must be biocompatible, promote the formation of little or no peritoneal adhesion, possess compatible texture and flexibility, providing the necessary resistance to protect the viscera and allow the movement of the abdomen.

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Breed traits seem to influence the dimensions of the cerebral ventricles in dogs. The ratios between the ventricles and the brain are crucial diagnostic criteria for suspected canine cognitive dysfunction (CCD). This study aimed to establish linear computed tomography (CT)-scan measurements of the cerebral ventricles in 55 Poodle dogs aged >7 years.

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Various animal models are used for research; however, non-human primates are well suited for biomedical research owing to their genetic homology with humans. The objective of this research was the anatomical characterization of red howler's kidneys in view of the scarcity of information in the literature. Protocols were approved by the Committee for Ethics in the Use of Animals at the Federal Rural University of Rio de Janeiro (number 018/2017).

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Puma yagouaroundi is a wild felid with wide distribution on the American continent. This paper aims to describe the origin and motor distribution of the nerves of the brachial plexus of P. yagouaroundi and compare the findings with the available descriptions for the Carnivora order.

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The Military Police of Rio de Janeiro state use dogs as a decisive tool for patrol and detection of drugs, weapons, and explosives. Complementary tests, such as echocardiography, are essential to maintain the integrity of these animals. This study aimed to evaluate the echocardiographic parameters of the working dogs belonging to the Military Police of Rio de Janeiro and compare them with the available data.

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Thoracic limbs are extremely versatile and exhibit informative characteristics about habits of the Carnivora order in the wild. Despite this relevance, comparative studies with quantitative variables on thoracic limb muscles are still scarce in carnivorans. The aims of this study were to measure the mass of the intrinsic muscles of the thoracic limb of neotropical species of the Carnivora order and to establish comparative conjectures.

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Anatomical variation in wild canids is rarely described. Altered shapes, uni- or bilaterally situated, were observed in ventral laminae of C6 and/or in C7 vertebral body of two fox species: Lycalopex gymnocercus and Cerdocyon thous. The specimens were young adults, collected dead on highways in southern Brazil.

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The clavicle is a bone whose development is related to the versatility of the thoracic limbs in mammals. Studies with vestigial structures are scarce and controversial, especially in the order Carnivora. The objective of this study was to verify the presence and to investigate the shape and constitution of the clavicle in neotropical carnivores.

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The characteristics of the muscles of the thoracic limb were evaluated in 22 specimens of Lycalopex gymnocercus. Descriptive and comparative analyses showed similarity with other canids in terms of topography and tendon insertions. Differences with the domestic dog were observed in the pectoralis profundus, triceps brachii and interflexorii muscles.

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Article Synopsis
  • The study aimed to investigate how hormonal deprivation affects the extracellular matrix in the penises of neutered cats compared to intact cats.
  • Researchers collected 27 penile samples, conducting histomorphometric analysis to examine various tissue parameters, such as elastic and collagen fiber density.
  • Results indicated that neutered cats had significantly lower elastic fiber density and higher collagen fiber density, suggesting reduced tissue compliance which may contribute to urethral obstructive disease.
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  • Pteronotus personatus is an insectivore bat with a high-protein diet, while Anoura geoffroyi is a nectarivore bat that consumes sugars like sucrose, glucose, and fructose.
  • The study aimed to compare the morphology of the endocrine pancreas in these two bat species using histological, stereological, and immunohistochemical techniques.
  • Results showed significant differences in pancreatic islet size, total number of islets, volume density, and distribution of α and β cells, indicating that their differing diets impact pancreatic structure and function.
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Twenty thoracic limbs of ten Lycalopex gymnocercus were dissected to describe origin and distribution of the nerves forming brachial plexuses. The brachial plexus resulted from the connections between the ventral branches of the last three cervical nerves (C6, C7, and C8) and first thoracic nerve (T1). These branches connected the suprascapular, subscapular, axillary, musculocutaneous, radial, median and ulnar nerves to the intrinsic musculature and connected the brachiocephalic, thoracodorsal, lateral thoracic, long thoracic, cranial pectoral and caudal pectoral nerves to the extrinsic musculature.

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Purpose: To update the gross and sonographic anatomy and propose landmarks to perform ultrasound-guided (US-guided) axillary brachial plexus block (BPB) in rabbits.

Methods: Forty New Zeeland's rabbit (NZR) cadavers were dissected and the nerves were trimmed, identified, measured, and photographed. Additionally, in twenty NZRs, sonographic images of brachial plexus (BP) were performed through a simple-resolution ultrasound device.

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Purpose: To assess pain in the immediate postoperative period in cats submitted into two different celiotomy techniques for ovariohysterectomy.

Methods: Fourteen healthy female cats up to three years old with a mean weight 2.75 kg, without breed specification, were used in this double blind experiment.

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Purpose: To determine the minimum volume of methylene blue (MB) to completely color the brachial plexus (BP) nerves, simulating an effective anesthetic block in cats.

Methods: Fifteen adult male cat cadavers were injected through subscapular approach with volumes of 2, 3, 4, 5 and 6 ml in both forelimbs, for a total of 30 brachial plexus blocks (BPB). After infusions, the specimens were carefully dissected preserving each nervous branch.

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Objective: To assess the morphological changes of penile vascular structures and the corpus cavernosum area in alloxan-induced diabetic rabbits.

Materials And Methods: Twenty male rabbits (2 months old) were divided into two groups with 10 rabbits each, the control group (CG) and the diabetic group (DG). The animals from DG received an intravenous injection of alloxan (100mg/kg) to induce the diabetes.

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Article Synopsis
  • The study aimed to explore how elastic fiber content in different tissues of the rabbit penis changes as the rabbits age.
  • Researchers sacrificed groups of rabbits at various ages (30, 120, 240, and 730 days) and analyzed tissue samples to determine elastic fiber volume with specific staining techniques.
  • Results showed a significant increase in elastic fiber content in older rabbits, especially in the corpus spongiosum, but this trend plateaued or decreased at two years old, suggesting possible age-related changes in penile tissue properties.
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  • Diphylla ecaudata, a vampire bat that primarily feeds on bird blood, has significant dietary adaptations affecting its pancreatic structure.
  • This study examined the pancreas of D. ecaudata and found a total of 23,900 pancreatic islets with varying sizes and distinct distributions of hormone-producing cells (insulin, glucagon, somatostatin).
  • The pancreas shows unique islet characteristics compared to other mammals, indicating specialized endocrine functions adapted to its hematophagous diet.
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