Study of the roles of caspase-3 and nuclear factor kappa B in myenteric neurons in a P2X7 receptor knockout mouse model of ulcerative colitis.

BACKGROUND: The literature indicates that the enteric nervous system is affected in inflammatory bowel diseases (IBDs) and that the P2X7 receptor triggers neuronal death. However, the mechanism by which enteric neurons are lost in IBDs is unknown. AIM: To study the role of the caspase-3 and nuclear factor kappa B (NF-κB) pathways in myenteric neurons in a P2X7 receptor knockout (KO) mouse model of IBDs. METHODS: Forty male wild-type (WT) C57BL/6 and P2X7 receptor KO mice were euthanized 24 h or 4 d after colitis induction by 2,4,6-trinitrobenzene sulfonic acid (colitis group). Mice in the sham groups were injected with vehicle. The mice were divided into eight groups (n = 5): The WT sham 24 h and 4 d groups, the WT colitis 24 h and 4 d groups, the KO sham 24 h and 4 d groups, and the KO colitis 24 h and 4 d groups. The disease activity index (DAI) was analyzed, the distal colon was collected for immunohistochemistry analyses, and immunofluorescence was performed to identify neurons immunoreactive (ir) for calretinin, P2X7 receptor, cleaved caspase-3, total caspase-3, phospho-NF-κB, and total NF-κB. We analyzed the number of calretinin-ir and P2X7 receptor-ir neurons per ganglion, the neuronal profile area (µm²), and corrected total cell fluorescence (CTCF). RESULTS: Cells double labeled for calretinin and P2X7 receptor, cleaved caspase-3, total caspase-3, phospho-NF-κB, or total NF-κB were observed in the WT colitis 24 h and 4 d groups. The number of calretinin-ir neurons per ganglion was decreased in the WT colitis 24 h and 4 d groups compared to the WT sham 24 h and 4 d groups, respectively (2.10 ± 0.13 vs 3.33 ± 0.17, P < 0.001; 2.92 ± 0.12 vs 3.70 ± 0.11, P < 0.05), but was not significantly different between the KO groups. The calretinin-ir neuronal profile area was increased in the WT colitis 24 h group compared to the WT sham 24 h group (312.60 ± 7.85 vs 278.41 ± 6.65, P < 0.05), and the nuclear profile area was decreased in the WT colitis 4 d group compared to the WT sham 4 d group (104.63 ± 2.49 vs 117.41 ± 1.14, P < 0.01). The number of P2X7 receptor-ir neurons per ganglion was decreased in the WT colitis 24 h and 4 d groups compared to the WT sham 24 h and 4 d groups, respectively (19.49 ± 0.35 vs 22.21 ± 0.18, P < 0.001; 20.35 ± 0.14 vs 22.75 ± 0.51, P < 0.001), and no P2X7 receptor-ir neurons were observed in the KO groups. Myenteric neurons showed ultrastructural changes in the WT colitis 24 h and 4 d groups and in the KO colitis 24 h group. The cleaved caspase-3 CTCF was increased in the WT colitis 24 h and 4 d groups compared to the WT sham 24 h and 4 d groups, respectively (485949 ± 14140 vs 371371 ± 16426, P < 0.001; 480381 ± 11336 vs 378365 ± 4053, P < 0.001), but was not significantly different between the KO groups. The total caspase-3 CTCF, phospho-NF-κB CTCF, and total NF-κB CTCF were not significantly different among the groups. The DAI was recovered in the KO groups. Furthermore, we demonstrated that the absence of the P2X7 receptor attenuated inflammatory infiltration, tissue damage, collagen deposition, and the decrease in the number of goblet cells in the distal colon. CONCLUSION: Ulcerative colitis affects myenteric neurons in WT mice but has a weaker effect in P2X7 receptor KO mice, and neuronal death may be associated with P2X7 receptor-mediated caspase-3 activation. The P2X7 receptor can be a therapeutic target for IBDs.

Study of tumor necrosis factor receptor in the inflammatory bowel disease.

Ulcerative colitis (UC) and Crohn's disease (CD) are part of Inflammatory Bowel Diseases (IBD) and have pathophysiological processes such as bowel necrosis and enteric neurons and enteric glial cells. In addition, the main inflammatory mediator is related to the tumor necrosis factor-alpha (TNF-α). TNF-α is a me-diator of the intestinal inflammatory processes, thus being one of the main cytokines involved in the pathogenesis of IBD, however, its levels, when measured, are present in the serum of patients with IBD. In addition, TNF-α plays an important role in promoting inflammation, such as the production of interleukins (IL), for instance IL-1ß and IL-6. There are two receptors for TNF as following: The tumor necrosis factor 1 receptor (TNFR1); and the tumor necrosis factor 2 receptor (TNFR2). They are involved in the pathogenesis of IBD and their receptors have been detected in IBD and their expression is correlated with disease activity. The soluble TNF form binds to the TNFR1 receptor with, and its activation results in a signaling cascade effects such as apoptosis, cell proliferation and cytokine secretion. In contrast, the transmembrane TNF form can bind both to TNFR1 and TNFR2. Recent studies have suggested that TNF-α is one of the main pro-inflammatory cytokines involved in the pathogenesis of IBD, since TNF levels are present in the serum of both patients with UC and CD. Intravenous and subcutaneous biologics targeting TNF-α have revolutionized the treatment of IBD, thus becoming the best available agents to induce and maintain IBD remission. The application of antibodies aimed at neutralizing TNF-α in patients with IBD that induce a satisfactory clinical response in up to 60% of patients, and also induced long-term maintenance of disease remission in most patients. It has been suggested that anti-TNF-α agents inactivate the pro-inflammatory cytokine TNF-α by direct neutralization, i.e., resulting in suppression of inflammation. However, anti-TNF-α antibodies perform more complex functions than a simple blockade.

New virtual platform for teaching comparative animal neuroanatomy based on metameric slices of the central nervous system.

With the limitations imposed by the COVID-19 pandemic, new technologies were used as methods to continue teaching and learning activities. This scenario brought forth the need to develop online tools for teaching. Therefore, this research aimed to develop a digital platform linking the knowledge about the central nervous system (CNS) anatomy from feline, equine, and sheep models. The platform was produced from the analysis of a collection of mesoscopic slides made from the sequenced cross-section of the CNS of a feline, an equine, and a sheep. All sections were analysed and stained using the Paul-Wiegert modified technique. The platform was organized in four modules: (1) Neuroanatomy of the Central Nervous System; (2) Neuroanatomy of Feline; (3) Neuroanatomy of Equine; and (4) Neuroanatomy of sheep. For each module, an explanatory document in PDF was developed, as well as video lectures and a descriptive atlas identifying the structures present in the encephalon and in the cervical part of the spinal cord. Even though there are numerous online platforms that allow the study of veterinary anatomy of different species and organs, the veterinary neuroanatomy platform presented here is the first platform that conjointly addresses the CNS anatomy of felines, equines, and sheep. Future research applying this platform as an aid to the study of neuroanatomy by students, teachers, and veterinary professionals should validate its use as a complementary tool for teaching and learning animal neuroanatomy.

Macroscopic, morphometric, and tomographic features of the mandible of the collared peccary (Pecari tajacu) applied to clinical morpho-physiology and imaging.

Veterinary dentistry is one of the specialties with the greatest potential to contribute to animal welfare; however, it requires a deep anatomical knowledge of the region to be treated. Therefore, the aim was to describe the macroscopic, morphometric, and tomographic anatomy of the mandible of the collared peccary in order to provide support for a better understanding of local morpho-physiology and to improve clinical procedures and interpretation of imaging exams in live adult specimens. Four mandibles from wild adult Pecari tajacu were used. The mandibles were submitted to CT scanning, and comparative analyses were performed using multiplanar views. Afterward, mandibular morphometry was conducted following the literature. Each hemimandible is composed of body, angle, and ramus. The main bony landmarks are the mandibular foramen, three main lateral mental foramina, two medial mental foramina, condylar and coronoid processes, and mandibular and angular notches. The teeth are bunodont, and the dental formula is I3/C1/PM3/M3. All bony structures were observed both in the prepared mandible and in the tomographic images and their 3D reconstruction. No obvious differences were observed in the morphometric data between males and females, or between right and left hemimandibles. It can be concluded that the mandible of the collared peccary may be anatomically structured to favor its omnivorous feeding habit. CT scan proved to be an excellent tool for evaluating the teeth and mandible, and it also provides reliable 3D bone reconstructions that can be helpful in the structural identification and the planning of oral care in live adult animals.

Comparative study of the digastric and the stylohyoid muscles between wild boars (Sus scrofa scrofa) and domestic swine (Sus scrofa domesticus): revisiting the gross anatomy.

Considering Suidae Familie as a perfect and viable experimental biomedical model for research applied to human medicine, it has been sought to describe the comparative anatomy of the digastric and the stylohyoid muscles between boars and domestic swine. Heads of Sus scrofa scrofa and Sus scrofa domesticus were dissected. The digastric muscle presented only one muscle belly as anatomical component of a tendinous origin in the jugular process of the occipital bone, and muscle insertion in the midventral edge of the caudal two thirds of the body of the mandible. Thus, its function is fundamentally associated with the lowering and the retracting of the mandible which, by the way, can deliver greater muscle power at lesser energy expense. For the stylohyoid muscle, the tendinous origin was in the laterocaudal edge of the dorsal third of the stylohyoid bone. The muscle insertion - primarily, was in the lateral and caudal edges from the mid third portion up to the ventral extremity of the thyrohyoid bone, and secondarily as a laterolateral aponeurotic blade which would unite, in a bilateral manner, an insertion that was common to the sternohyoid, the geniohyoid, and the mylohyoid muscles in a median ventral region. This morphology were similar to the two specimens studied expanding the information available, which were completely unknown for the suidae until the moment.

Enteric nervous system and inflammatory bowel diseases: Correlated impacts and therapeutic approaches through the P2X7 receptor.

The enteric nervous system (ENS) consists of thousands of small ganglia arranged in the submucosal and myenteric plexuses, which can be negatively affected by Crohn's disease and ulcerative colitis - inflammatory bowel diseases (IBDs). IBDs are complex and multifactorial disorders characterized by chronic and recurrent inflammation of the intestine, and the symptoms of IBDs may include abdominal pain, diarrhea, rectal bleeding, and weight loss. The P2X7 receptor has become a promising therapeutic target for IBDs, especially owing to its wide expression and, in the case of other purinergic receptors, in both human and model animal enteric cells. However, little is known about the actual involvement between the activation of the P2X7 receptor and the cascade of subsequent events and how all these activities associated with chemical signals interfere with the functionality of the affected or treated intestine. In this review, an integrated view is provided, correlating the structural organization of the ENS and the effects of IBDs, focusing on cellular constituents and how therapeutic approaches through the P2X7 receptor can assist in both protection from damage and tissue preservation.

Comparative anatomy of blue-and-yellow macaw (Ara ararauna) and toco toucan (Ramphastos toco) beaks using macroscopic analysis and computerized tomography / Anatomía comparada de los picos de guacamayo azul y amarillo (Ara ararauna) y de tucán toco (Ramphastos toco) mediante análisis macroscópico y tomografía computarizada

SUMMARY: Clinically, avian medicine still finds it very difficult to treat wild patients due to the lack of reliable information about their anatomy and physiological parameters that make comparative analyzes possible. Considering that computed tomography (CT) is one of the most viable alternatives in radiography of the head, we describe the comparative anatomy of the beak in the Ara ararauna and the Ramphastos toco through this imaging modality and macroscopy analysis, providing additional information about their conformation and topography for clinical exams. Adult specimens of each were dissected after the CT and beaks were removed for macroscopic analyses. The macroscopic and tomographic findings for both species confirm the similarities in beak morphology and the dietary peculiarities of each.The CT scan proved to be a useful tool to visualize internal structures of the skull through a detailed virtopsy of regions that are difficult to access by the usual necropsy with a scalpel.

RESUMEN: Debido a la escasa información de la anatomía y de los parámetros fisiológicos que hacen posible los análisis comparativos en la medicina aviar, clínicamente resulta muy difícil el tratamiento de estos animales. Considerando que la tomografía computarizada es una buena alternativa, estudiamos la anatomía comparativa del pico en Ara ararauna y Toco Toucan utilizando imágenes y un análisis de macroscopía. Estos métodos proporcionaron información adicional referente a su conformación y topografía para el trabajo clínico. Después de analizar la tomografía se disecaron las muestras de especímenes adultos y se retiraron los picos para un análisis macroscópico. Los hallazgos macroscópicos y tomográficos para ambas especies corroboraron la relación morfológica entre los picos y las peculiaridades dietéticas de cada uno. Se demostró además, que la tomografía computarizada es una herramienta útil para visualizar las estructuras internas del cráneo de las aves, a través de una virtopsia detallada en áreas de difícil acceso durante una necropsia habitual.

Morphometry of the mandibular foramen applied to the local anesthetic block to inferior alveolar nerve in boars (Sus scrofa scrofa Linnaeus, 1758) / Morfometria do forame mandibular aplicada ao bloqueio anestésico local do nervo alveolar inferior de javalis (Sus scrofa scrofa Linnaeus, 1758)

Boars kept on commercial farms use their canine teeth as a mechanism of defense and attack in order to express their natural instincts, which could result in fractures of the teeth and jaws. Thus, utilizing local desensitization of the inferior alveolar nerve is crucial for executing therapeutic procedures in the oral cavities of those animals. Then, the goal is to carry out the morphometry of the mandibular foramen of that species, correlating it with the mandibular structures, while doing so in the safest manner for the animals. For that purpose, six hemimandibles of young-aged Sus scrofa scrofa were used, from which the proposed measurements were taken. On average, the lateral margin of the condylar process stood 142.43 mm away from the root of the lower medial incisive tooth. The longitudinal axis of the body of the mandible measured 22.3 mm at the level of the diastema that exists between the fourth lower premolar tooth and the first lower molar tooth. The mandibular foramen, from the caudal limit of the ventral margin, would be positioned at 26.6 mm from the ventral margin of the angle of the mandible in that level, 34.92 mm away from the medial margin of the condylar process, and 38.63 mm away from the dorsal limit from the caudal margin of the coronoid process. The lack of statistically significant differences, and observing that the osseous accident under scrutiny had been positioned in the ramus of the mandible, indicated that the proposed procedure should be performed from the introduction of the needle in an oblique and rostrodorsal direction for 2.0 cm, and angulated at 60º with the anatomic reference created by the medial demarcation obtained via the support of the thumb on the lateral margin of the ramus of the mandible, ventrally to the zygomatic arch, all while preserving neighboring structures and establishing an unheard-of anesthetic methodology for boars.(AU)

Javalis mantidos em criatórios comerciais utilizam os dentes caninos como mecanismo de defesa e ataque a fim de expressar seus instintos naturais, o que pode resultar em fraturas dentárias e da mandíbula propriamente dita. Desta forma, propiciar a dessensibilização local do nervo alveolar inferior é essencial para a execução de procedimentos terapêuticos na cavidade oral destes animais. Logo, objetivou-se realizar a morfometria do forame mandibular desta espécie a fim de correlacioná-lo com as estruturas mandibulares, inferindo, também, sobre a forma mais segura de realização da referida técnica nos espécimes. Para tanto, foram utilizadas seis hemimandíbulas de Sus scrofa scrofa jovens, a partir das quais foram realizadas as mensurações propostas. Em média, a margem lateral do processo condilar distanciou-se 142,43 mm da raiz do dente incisivo medial inferior; o eixo longitudinal do corpo da mandíbula mediu 22,3 mm ao nível do diastema existente entre o quarto dente pré-molar e o primeiro dente molar inferiores; e o forame mandibular, a partir do extremo caudal de sua margem ventral, posicionou-se a 26,6 mm da margem ventral do ângulo da mandíbula neste nível, 34,92 mm da margem medial do processo condilar, e 38,63 mm do extremo dorsal da margem caudal do processo coronóide. Na falta de diferenças estatisticamente significantes, e observando que o acidente ósseo estudado posicionou-se no ramo da mandíbula, indica que o procedimento proposto deva ser realizado a partir da introdução da agulha em sentido oblíquo rostroventral por 2,0 cm e angulada a 60º com o referencial anatômico criado pela delimitação medial obtida pelo apoio do dedo polegar na margem lateral do ramo da mandíbula, ventralmente ao arco zigomático, preservando as estruturas próximas e definindo-se uma metodologia anestésica inédita para os Javalis.(AU)

Morphometry of mental foramina applied to local anesthesia in hoary fox (Lycalopex vetulus Lund, 1842) / Morfometría de forámenes mentales aplicada a la anestesia local en zorro de campo común (Lycalopex vetulus Lund, 1842)

In order to perform local anaesthetic blockade of the mental nerves, it is fundamentally to determine anatomical references, including the precise identification of the mental foramina; however, the literature does not present specific data on such structures in the Hoary Fox. Therefore, the objective was describing the morphometry of the mental foramina of this specie, in order to correlate its topographies with the mandibular anatomical reference points, supporting the effective technique for mental desensitization. For this purpose, four mandibles of adult bodies of Lycalopex vetulus were used. Bilaterally, three mental foramina were observed located on the rostral third of the lateral margin of the mandibular body. One of them is more caudal, positioned ventrally to the lower third premolar tooth; a medium one, is located ventrally to the lower first premolar tooth; and a rostral one, placed ventrally to the lower intermediate incisor tooth. There were no statistically significant differences between the antimeres. Therefore, it is indicated that the local anaesthetic block of the mental nerves in this species should be performed by inserting the needle approximately 4.4 mm in a ventrodorsal direction. It is necessary positioning it perpendicularly to the ventral margin of the mandibular body and juxtaposed to its lateral face, using as anatomical reference the interalveolar space located between the first two lower premolar teeth. Thus, that the point established for anaesthetic injection (caudal limit of the ventral margin of the middle mental foramen), provides greater safety for its realization since, for small animals, the recommendation for blockade is represented by needle penetration on the direction of emergence of the mental nerve and artery from this foramen, which makes these structures more exposed to iatrogenic lesions resulting from the technique.

Para realizar el bloqueo anestésico local de los nervios mentales, es fundamental determinar referencias anatómicas, incluida la identificación precisa de los forámenes mentales; sin embargo, la literatura no presenta datos específicos referente a estas estructuras en el zorro de campo común. Por lo tanto, el objetivo fue describir la morfometría de los forámenes mentales de esta especie, para correlacionar sus topografías con los puntos de referencia anatómicos mandibulares, apoyando la técnica efectiva para la desensibilización mental. Para este propósito, se utilizaron cuatro mandíbulas de Lycalopex vetulus adultos. Bilateralmente, se observaron tres resistencias mentales ubicadas en el tercio rostral del margen lateral del cuerpo mandibular. Uno de ellos es más caudal, posicionado ventralmente hacia el tercer diente premolar inferior; uno mediano, localizado ventralmente hacia el primer diente premolar inferior; y uno rostral, colocado ventralmente al diente incisivo intermedio inferior. No se observaron diferencias estadísticamente significativas entre los antímeros. Por lo tanto, el bloqueo anestésico local de los nervios mentales en esta especie debe realizarse insertando la aguja aproximadamente 4,4 mm en dirección ventrodorsal. Es necesario colocar ésta perpendicularmente al margen ventral del cuerpo mandibular y yuxtapuesto a su cara lateral, utilizando como referencia anatómica, el espacio interalveolar ubicado entre los dos primeros dientes premolares inferiores. De este modo, el punto establecido para la inyección de anestesia (límite caudal del margen ventral del foramen mental medio), proporciona una mayor seguridad para su realización ya que, para los animales pequeños, la recomendación de bloqueo está representada por la penetración de la aguja en la dirección de emergencia del nervio mental y la arteria de este foramen, lo que hace que estas estructuras estén más expuestas a las lesiones iatrogénicas resultantes de la técnica.

Origin and distribution of the coronary arteries of boars / Origem e distribuição das artérias coronárias de javalis

The heart of a domestic swine is similar to that of a human regarding anatomy, blood perfusion, and distribution of nurturing arteries. In addition to the similarities, its low cost compared with other species is also one of the reasons these animals have been increasingly used in medical schools and in clinical, surgical, and pharmacological studies. Therefore, we aimed to identify the origin and distribution of the right and left coronary arteries of boars, emphasizing the configuration and macroscopic representativity of their branches while characterizing a possible dominance concerning the type of circulation and the potential use of this animal as an experimental model, hence boars are the ancestors of the domestic pigs. The left coronary artery has bifurcated into paraconal interventricular branch and circumflex branch; or it has trifurcated into paraconal interventricular branch, the oblique branch, and into the left circumflex branch. The right coronary artery has originated the marginal branches to the right ventricle and the right circumflex branch, which has branched out in the subsinuous interventricular branch. Anastomoses have stood out among the paraconal and subsinuous interventricular branches ­ where a right dominant coronary artery occurred ­ and between the right and left circumflex branches. We concluded that the morphology and the distribution of the coronary arteries of boars resemble those of a human and, thus, our results are useful for the conception of experimental hemodynamics and possible use as process models.(AU)

O coração dos suínos domésticos apresenta semelhanças ao dos humanos mediante a anatomia, perfusão sanguínea e configuração da distribuição de suas artérias nutridoras. Tendo um menor custo para sua aquisição quando comparado a outras espécies, e dada sua similaridade apresentada, o uso desses animais nas escolas de medicina, em estudos clínicos, cirúrgicos e farmacológicos tem aumentado. Portanto, objetivou-se identificar a origem e distribuição das artérias coronárias direita e esquerda de javalis com ênfase na configuração e representatividade macroscópica dos ramos derivados das mesmas, caracterizando uma possível dominância quanto ao tipo de circulação e o potencial uso deste suídeo como modelo experimental, visto que são considerados ancestrais dos suínos domésticos. A artéria coronária esquerda bifurcou-se e deu origem aos ramos interventricular paraconal e circunflexo esquerdo, ou trifurcou-se nos ramos interventricular paraconal, oblíquo e circunflexo esquerdo. Já a artéria coronária direita deu origem aos ramos marginal para o ventrículo direito e circunflexo direito que, por sua vez, ramificou-se no ramo interventricular subsinuoso. Foram evidenciadas anastomoses entre os ramos interventriculares paraconal e subsinuoso, e entre os ramos circunflexos direito e esquerdo e, conforme tal origem do ramo interventricular subsinuoso, a forma de dominância coronariana foi predominantemente direita. Conclui-se que a morfologia e distribuição das artérias coronárias de javalis se assemelham à do homem e, desse modo, nossos resultados são úteis para sua concepção da hemodinâmica experimental, e possível utilização como modelos processuais.(AU)