Highly pathogenic avian influenza H5N1 virus infections in pinnipeds and seabirds in Uruguay: Implications for bird-mammal transmission in South America.

The highly pathogenic avian influenza viruses of clade 2.3.4.4b have caused unprecedented deaths in South American wild birds, poultry, and marine mammals. In September 2023, pinnipeds and seabirds appeared dead on the Uruguayan Atlantic coast. Sixteen influenza virus strains were characterized by real-time reverse transcription PCR and genome sequencing in samples from sea lions (Otaria flavescens), fur seals (Arctocephalus australis), and terns (Sterna hirundinacea). Phylogenetic and ancestral reconstruction analysis showed that these strains have pinnipeds most likely as the ancestral host, representing a recent introduction of clade 2.3.4.4b in Uruguay. The Uruguayan and closely related strains from Peru (sea lions) and Chile (sea lions and a human case) carry mammalian adaptative residues 591K and 701N in the viral polymerase basic protein 2 (PB2). Our findings suggest that clade 2.3.4.4b strains in South America may have spread from mammals to mammals and seabirds, revealing a new transmission route.

Inner ventricular structures and valves of the heart in white rhinoceros (Ceratotherium simum).

In this study, we describe the internal structures of both ventricles and the valvular apparatus of the heart of the white rhino. In the right of the heart, three papillary muscles were found in septal and marginal walls and m. papillaris magnus was the biggest. There was only one m. papillaris parvus in the right ventricle. The right atrioventricular valve was tricuspid, and the parietal cusp was longest. In the left of the heart, two papillary muscles were found on the septal wall and the subauricular was the biggest. The left atrioventricular valve was bicuspid and the parietal cusp was longest. There were no nodules in the valves of the pulmonary trunk and aorta, and the semilunar valves had many fibrous folds and transparent parts. Within the cardiac skeleton there was a cartilago cordis which occupied a small part of the right fibrous trigone. While the right ventricle included only one septomarginal trabecula, there were many trabeculae in the left ventricle. In both ventricles, the endocardium was thin and the subendocardial network was visible, also their continuation with the septomarginal trabeculae. We also found many trabeculae carneae in the dorsal part of the ventricles.

Distribución de las arterias coronarias en el rinoceronte blanco (Ceratotherium simum) / Distribution of coronary arteries in the white rhinoceros (Ceratotherium simum)

Nosotros disecamos un corazón de rinoceronte blanco con el objetivo de dar una descripción anatómica de la distribución de sus arterias coronarias. Se registró la longitud y el calibre de las ramas principales. Las arterias coronarias tenían el mismo calibre en su origen y la arteria coronaria derecha emitía la rama interventricular subsinusal, el rinoceronte correspondía al patrón de coronaria derecha. La arteria coronaria izquierda emitida en el seno izquierdo de la aorta se dividía en tres ramas (trifurcación), la rama interventricular paraconal, la rama circunfleja y la rama diagonal.

We dissected the heart of white rhino in order to give an anatomical description of the distribution of coronary arteries. We recorded the length and caliber of the main branches. The coronary arteries were the same caliber at its origin and the right coronary artery emitted subsinusal interventricular branch, rhinoceros corresponded to the pattern of the right coronary artery. The left coronary artery is released into the left breast of the aorta was divided into three branches (trifurcation) paraconal interventricular branch, circumflex branch and diagonal branch.

Gross anatomy of the heart in the western grey kangaroo (Macropus fuliginosus) / Anatomía macroscópica del corazón en el canguro gris occidental (Macropus fuliginosus)

The aim of this study was provide a description of the macroscopic heart anatomy of the kangaroo Macropus fuliginosus. The terms of the Nomina Anatomica Veterinaria were employed. Heart did not have interventricular sulcus. Auricles were located in both faces of the heart. Right ventricle had slight septomarginal trabecula that extended between papilar muscles and the parietal wall. Right ventricle parietal wall had plenty of trabecula carneae. Septal wall was smooth and had three papilar muscles. Papilar muscles of left ventricle were two and they were located over parietal wall. Septal walls and parietal of left ventricle were full of trabecula carneae that surrounded papilar muscles. Two vessels derived from the aorta, right and left sinus coronary arteries and a septal artery. Septal artery gave irrigation to interventricular septum and derived from left sinus of the aorta and their lumen had a higher diameter than the left coronary artery. Coronary arteries had intra myocardic route.

El objetivo de este estudio fue proporcionar una descripción de la anatomía macroscópica de corazón el canguro Macropus fuliginosus. Fueron empleados los términos de la Nomina Anatómica Veterinaria. El corazón no tuvo surco interventricular. Las aurículas se encontraban en ambas caras del corazón. El ventrículo derecho presentó una trabécula septomarginal delgada que se extendía entre los músculos de la pared papilar y parietal. La pared parietal del ventrículo derecho presentó un montón de trabéculas carnosas. La pared septal era lisa y tenía tres músculos papilares. Los músculos papilares del ventrículo izquierdo fueron dos y se encontraron en la pared parietal. Las paredes septal y parietal del ventrículo izquierdo estaban llenas de trabéculas carnosas que rodeaban los músculos papilares. Dos vasos procedentes desde la aorta, arterias del seno coronario derecho e izquierdo, y la arteria septal. La arteria septal dio irrigación al septo interventricular y derivada desde el seno izquierdo de la aorta y su lumen tuvo un mayor diámetro que la arteria coronaria izquierda. Las arterias coronarias presentaron un trayecto intramiocardico.

Gross heart anatomy of Arctocephalus australis (Zimmerman, 1783).

Little research has been carried out on the gross visceral anatomy of the Otariidae, and the anatomical information for the southern fur seals, Arctocephalus spp., is scant. The aim of the present study was to describe the external and internal conformation, and the sanguineous irrigation of the heart of Arctocephalus australis. Twelve hearts of Arctocephalus australis were studied by simple dissection. In the right ventricle the trabeculae carneae were well developed and there were three or more papillary muscles. In the left ventricle there were two papillary muscles, subatrialis and subauricularis, attached to the parietal wall. There was also a great development of trabeculae carneae which occupied almost all of the ventricle, from the left atrioventricular valve up to the proximities of the expulsion route. A large quantity of muscular strands were found extending themselves between the trabeculae carneae, becoming more dense and forming a network when near the apex. The distribution of the branches of the coronary arteries was highly variable and no heart was similar to another one in this sense. In the majority of the hearts the subsinosal interventricular branch proceeded from the right coronary artery. It is concluded that there were many differences between the heart of the Arctocephalus australis and the heart of the domestic dog, contrary to what has been suggested for other genera of Otariidae.

Foramen Vertebral Lumbar Inconstante en Bos taurus / Inconstant Lumbar Vertebral Foramen in Bos taurus

En Anatomía Veterinaria la investigación de los forámenes de la columna vertebral es necesaria para expandir nuestro conocimiento de osteología sistemática, y para el estudio de la vascularización de la columna vertebral y de la médula espinal. El objetivo de este trabajo es informar acerca de la presencia y características de forámenes inconstantes hallados en las vértebras lumbares bovinas. Quince de 100 (15 %) vértebras lumbares presentaban forámenes. Todos los forámenes estaban localizados en el cuerpo de la vértebra lumbar sobre su cara lateral derecha. Cuatro de estas vértebras eran la lumbar 2 y tres de ellas la lumbar 5.

In Veterinary Anatomy the research of the foramina of the vertebral column is necessary for to expand our knowledge of systematic osteology, and for study of the vascularization of the vertebral column and spinal cord. The objective of this work is to inform about presence and characteristics of inconstant foramina found in bovine lumbar vertebrae. Fifteen of 100 (15 %) of lumbar vertebrae presented foramina. All foramina were found at the body of lumbar vertebrae on their right lateral face. Four of these vertebrae were lumbar 2 and three of them lumbar 5.

Anatomía cardíaca de Pontoporia blainvillei / Cardiac anatomy of the Pontoporia blainvillei

El objetivo de este estudio fue describir la conformación interna y externa y la irrigación del corazón del delfín franciscana de la Plata (Pontoporia blainvillei) para lo cual fueron disecados 12 corazones. El pericardio se fijaba caudalmente al diafragma, ventralmente al músculo transverso torácico y, lateralmente, a las costillas y músculos intercostales. El corazón era aplastado dorsoventralmente, su base era craneal, su ápex era compartido por ambos ventrículos. El ventrículo izquierdo era de pared gruesa, mientras que la del ventrículo derecho más delgada y depresible. La cara ventral correspondía a la cara auricular y la cara dorsal a la cara atrial de la Nomina Anatomica Veterinaria, 2005 (NAV). En la conformación interior del atrio derecho destacaba el gran desarrollo de la cresta terminal y de la fosa oval. Dentro del ventrículo derecho, los músculos papilares se distribuían en subbarterioso, magnus y parvi. Una trabécula septomarginal se extendía entre los músculos papilares subarterioso y magnus. También fueron observadas trabéculas menores del mismo tipo, situadas más ventralmente a la anterior. Las venas pulmonares se unían en un tronco común antes de llegar al atrio izquierdo. El ventrículo izquierdo tenía dos músculos papilares bien desarrollados. La irrigación cardíaca arterial mostraba un predominio de la arteria coronaria izquierda y se notaba la presencia de anastomosis intercoronarias.

The aim of this study is to describe the external and internal conformation and the arterial irrigation of La Plata Dolphin's heart (Pontoporia blainvillei). Twelve animals obtained from nets of fishing ships were used and their hearts were studied by means of simple dissection. The pericardium was fixed caudally to the diaphragm, ventrally to the thoracic transverse muscle and laterally to the ribs and intercostal muscles. The heart weighted about 115 grams, was flattened dorsoventrally, its base was cranial, its apex was shared by both ventricles. The ventral face corresponds to the auricular face of the Nomina Anatomica Veterinaria (NAV), and the dorsal face corresponds to the atrial face. In the internal conformation of the right atrium the great development of the crista terminalis and the fossa ovalis stood out. Inside the right ventricle the papillaris muscles were observed distributed in subarteriosus, magnus and parvi. The dextra septomarginal trabecules were multiple and situated between the papillaris muscles. In the left ventricle they had two well developed papillaris muscles. The left coronary artery is the most important vessel in the arterial irrigation of the cardiac territory.