Toothed Whales Have Black Neurons in the Blue Spot.

Neuromelanin (NM) is a dark polymer pigment that is located mostly in the human substantia nigra, and in the locus ceruleus, referred to as "the blue spot". NM increases linearly with age, and has been described mainly in the human brain; however, it also occurs in the neurons of monkeys, horses, giraffes, cattle, sheep, goats, dogs, rats, and even in frogs. While in most of these mammals NM shows the histochemical and ultrastructural features typical of lipofuscins, human NM is confined within cytoplasmic organelles that are surrounded by a double membrane, suggesting an autophagic origin. In a study on the morphology of the locus ceruleus of the family Delphinidae, the presence of a variable quantity of NM in the interior of locus ceruleus neurons was observed for the first time; meanwhile, nothing is known about its ultrastructure and composition. Transmission electron microscopy demonstrated in two toothed whales-an Atlantic spotted dolphin (Stenella frontalis; family Delphinidae) and a Blainville's beaked whale (Mesoplodon densirostris; family Ziphiidae)-the presence of melanin granules associated with lipid droplets and membranes that were very similar to that of human NM. The relationship between NM and neuronal vulnerability must be studied in depth, and cetaceans may offer a new natural-spontaneous comparative model for the study of NM and its implication in neurodegenerative diseases.

Morphological Structure of the Aortic Wall in Deep Diving Cetacean Species: Evidence for Diving Adaptation.

This study analyses the aortic wall structure in nine cetacean species with deep diving habits belonging to four Odontoceti families: Ziphiidae, Kogiidae, Physteridae, and Delphinidae. Samples of ascending, thoracic and abdominal aorta were processed for histological and morphometric studies. The elastic component was higher in the proximal aortic segments, and the muscular elements increased distally in all cases. Morphometric analyses showed that all families presented a decrease in the thickness of the arterial wall and the tunica media along the aorta. The reduction was dramatic between ascending and thoracic aorta in the Physeteridae specimens; meanwhile, the other three families showed a more uniform decrease between the ascending, thoracic and abdominal aorta. The decline was not correlated with a reduced elastic or lamellar unit thickness but with a loss of lamellar units. The organization of the elements in the aortic wall did not show essential modifications between the four families, resembling the structure described previously in the shallow and intermediate diving dolphins. Our findings support that the difference in the morphometric characteristics of the different segments in the aortic wall is likely related to the diving habit more than the absolutes values of any other parameter.

Budd-Chiari-like pathology in dolphins.

Nearly two decades ago, pathologic examination results suggested that acoustic factors, such as mid-frequency active naval military sonar (MFAS) could be the cause of acute decompression-like sickness in stranded beaked whales. Acute systemic gas embolism in these whales was reported together with enigmatic cystic liver lesions (CLL), characterized by intrahepatic encapsulated gas-filled cysts, tentatively interpreted as "gas-bubble" lesions in various other cetacean species. Here we provide a pathologic reinterpretation of CLL in odontocetes. Among 1,200 cetaceans necropsied, CLL were only observed in four striped dolphins (Stenella coeruleoalba), with a low prevalence (2%, N = 179). Together, our data strongly suggest that CLL are the result of the combination of a pre-existing or concomitant hepatic vascular disorder superimposed and exacerbated by gas bubbles, and clearly differ from acute systemic gas embolism in stranded beaked whales that is linked to MFAS. Budd-Chiari-like syndrome in dolphins is hypothesized based on the present pathologic findings. Nonetheless, further researched is warranted to determine precise etiopathogenesis(es) and contributing factors for CLL in cetaceans.

Pulmonary and Systemic Skeletal Muscle Embolism in a Beaked Whale with a Massive Trauma of Unknown Aetiology.

An adult female Sowerby's beaked whale was found floating dead in Hermigua (La Gomera, Canary Islands, Spain) on 7 December 2016. Severe traumas of unknown aetiology were attributed, and the gross and microscopic findings are consistent with catastrophic trauma as a cause of death. Rib fractures affected the intercostals, transverse thoracis skeletal muscles, and thoracic rete mirabile. Degenerated muscle fibres were extruded to flow into vascular and lymphatic vessels travelling to several anatomic locations into the thoracic cavity, including the lungs, where they occluded the small lumen of pulmonary microvasculature. A pulmonary and systemic skeletal muscle embolism was diagnosed, constituting the first description of this kind of embolism in an animal. The only previous description has been reported in a woman after peritoneal dialysis. Skeletal pulmonary embolism should be considered a valuable diagnostic for different types of trauma in vivo in wild animals. This is especially valuable when working with decomposed carcasses, as in those cases, it is not always feasible to assess other traumatic evidence.

Microdissection of the Human Renal Nervous System: Implications for Performing Renal Denervation Procedures.

Despite the use of renal denervation to treat hypertension, the anatomy of the renal nervous system remains poorly understood. We performed a detailed quantitative analysis of the human renal nervous system anatomy with the goal of optimizing renal denervation procedural safety and efficacy. Sixty kidneys from 30 human cadavers were systematically microdissected to quantify anatomic variations in renal nerve patterns. Contrary to current clinical perception, not all renal innervation followed the main renal artery. A significant portion of the renal nerves (late arriving nerves) frequently reached the kidney (73% of the right kidney and 53% of the left kidney) bypassing the main renal artery. The ratio of the main renal artery length/aorta-renal hilar distance proved to be a useful variable to identify the presence/absence of these late arriving nerves (odds ratio, 0.001 (95% CI, 0.00002-0.0692; P: 0.001) with a cutoff of 0.75 (sensitivity: 0.68, specificity: 0.83, area under ROC curve at threshold: 0.76). When present, polar arteries were also highly associated with the presence of late arriving nerve. Finally, the perivascular space around the proximal main renal artery was frequently occupied by fused ganglia from the solar plexus (right kidney: 53%, left kidney: 83%) and/or by the lumbar sympathetic chain (right kidney: 63%, left kidney: 60%). Both carried innervation to the kidneys but importantly also to other abdominal and pelvic organs, which can be accidentally denervated if the proximal renal artery is targeted for ablation. These novel anatomic insights may help guide future procedural treatment recommendations to increase the likelihood of safely reaching and destroying targeted nerves during renal denervation procedures.

Morphological structure of the aortic wall in three Delphinid species with shallow or intermediate diving habits: Evidence for diving adaptation.

Some modifications in the vascular system of marine mammals provide adaptive advantages for diving. This study analyses the organisation of the aortic wall in dolphins, observing artery changes in volume and blood pressure for diving behaviour. Samples of three aortic segments (ascending, thoracic and abdominal) of three dolphin species were processed for histological and morphometric studies. The three dolphin species used, striped dolphin (Stenella coeruleoalba), Atlantic spotted dolphin (Stenella frontalis) and common dolphin (Delphinus delphis), have shallow or intermediate diving habits. Our results indicated that the components of the aortic wall of the dolphins had different dispositions in the three selected segments. The aortic wall decreased in thickness along its length due to a loss of the lamellar units in the tunica media and a thinning of the main elements of the lamellar units along the artery. The life stage had little influence on the thickness of the aortic wall except for the ascending aorta. The weight, body length, species or sex of the specimen did not significantly influence the thickness of the wall or the lamellar units. In summary, the histological and morphometric aortic structure in dolphins, in relation to the studied parameters, seems to be similar to that previously described of terrestrial mammals such as pigs, except for a larger difference in the proportion of lamellar units between the ascending and thoracic segments.

Comparative morphology, histology, and cytology of odontocete cetaceans prostates.

The prostate is the only male accessory gland in cetaceans. However, little is known about this organ in these species. Anatomical and histological characteristics of the prostate have been described in only a few cetacean species, further, one study reported a high incidence of prostatic pathologies in cetaceans that may impair reproduction. The objective of this work was to describe and compare the morphological, histological, and cytological characteristics of the prostate in different odontocete cetaceans. To this end, the prostate glands of 47 animals from nine different species of cetaceans were macroscopically and microscopically studied. Members of the families Delphinidae, Ziphiidae, and Physeteridae were included. In general, the prostate appeared as a musculo-glandular organ with two distinct parts-the Corpus prostatae and the Pars disseminata prostatae. In the pygmy sperm whale (Kogia breviceps) and the Cuvier's beaked whale (Ziphius cavirostris), the prostate was a discrete gland with a small Corpus prostatae. Microscopically, the prostates of different delphinids species shared similarities; however, the prostate of the pygmy sperm whale revealed significant histological differences compared to those of the delphinids. Immunohistochemical analysis was performed using low- and high-molecular-weight cytokeratin, vimentin, and prostatic specific antigen commercial antibodies. Electron microscopy analysis was performed on the prostate of a bottlenose dolphin and the cytomorphological differences among the major epithelial components of the prostatic epithelium were described. Anat Rec, 2019. © 2019 American Association for Anatomy Anat Rec, 303:2036-2053, 2020. © 2019 American Association for Anatomy.

The morphogenesis of the renal plexus: Renal artery and sympathetic fibers.

To examine the origin and development of the renal plexus and its relationship to the renal vessels in embryos and early human fetuses. Serial sections of 34 human embryos (stages 16 to 23 of Carnegie, 4 or 5-8 weeks) and 38 fetuses (9-19 weeks) were analyzed. Throughout the embryonic period, the kidney was not innervated by the renal plexus. Those nerves appeared at the beginning of the early fetal period (9 weeks) as branches given off by the immature autonomic abdominal plexus. The renal nerves started to approach to the kidney during the early fetal period at 9-10 weeks of development. They were distributed in close proximity to the renal arteries and their branches. They were observed first with the settlement of the renal veins. The renal artery is present as a branch of the abdominal aorta at stage 19 (between 6 and 7 weeks) prior to development of the renal plexus. The renal veins were not present during the embryonic period but appeared at the start of the fetal period, along with the renal nerves that emerged from segmented sympathetic para-aortic bodies (SPBs). Clin. Anat. 32:272-276, 2019. © 2018 Wiley Periodicals, Inc.

The gross anatomy of the renal sympathetic nerves revisited.

Catheter-based renal denervation techniques focus on reducing blood pressure in resistant hypertension. This procedure requires exact knowledge of the anatomical interrelation between the renal arteries and the targeted renal nervous plexus. The aim of this work was to build on classical anatomical studies and describe the gross anatomy and anatomical relationships of the renal arteries and nerve supply to the kidneys in a sample of human cadavers. Twelve human cadavers (six males and six females), age range 73 to 94 years, were dissected. The nervous fibers and renal arteries were dissected using a surgical microscope. The renal plexus along the hilar renal artery comprised a fiber-ganglionic ring surrounding the proximal third of the renal artery, a neural network along the middle and distal thirds, and smaller accessory ganglia along the course of the nerve fibers. The fibers of the neural network were mainly located on the superior (95.83%) and inferior (91.66%) surfaces of the renal artery and they were sparsely interconnected by diagonal fibers. Polar arteries were present in 33.33% of cases and the renal nerve pattern for these was similar to that of the hilar arteries. Effective renal denervation needs to target the superior and inferior surfaces of the hilar and polar arteries, where the fibers of the neural network are present. Clin. Anat. 29:660-664, 2016. © 2016 Wiley Periodicals, Inc.

Carotid bifurcation - clinical relevance

Common carotid artery bifurcation (CCAb) branches and topography of surrounding structures are essential for diagnosis and surgical procedures in the neck. The aim of this study was to add evidence of the variability found in the CCAb region relative to bifurcation location, arterial carotid branches and surrounding structures in the studied sample. This study was performed on 38 CCAbs from 19 cadavers. The CCAbs were located at the level of the superior border of the thyroid cartilage (TC) in 63.15% (24/38) of the cases, and at the hyoid bone (HB) level in 36.85% (14/38) of the sample. There was asymmetry between the right and the left side in 10.52 % (2/19) of the cadavers. The superior thyroid artery (STA) arose from the common carotid artery (CCA) or the CCAb in 34.21% (13/38) of the cases. The ascending pharyngeal artery (APA) arose from the internal carotid artery (ICA) in 2.6% (1/38) of the cases. The vagus nerve (VN) ran posterior to the CCAb in 89.48% (34/38) of the cases, and anterolateral in 10.58% (4/38) of the cases. The carotid body (CB) was found posterior in the angle of the CCAb in 73.68% (28/38) of the cases. The carotid bifurcation region showed a considerable variability in the studied sample. The findings of the study, together with other previously published studies, should be taken into consideration by physicians and surgeons to avoid clinical complications

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Estrogen receptor expression and synthesis in the human internal thoracic artery.

The inhibition of vascular smooth muscle cell proliferation is mediated through two intracellular estrogen receptors (ERs), ER-alpha and ER-beta. Deletion variants of ER-alpha have been decribed for cultures of smooth muscle cells. The internal thoracic artery is frequently used as coronary artery bypass graft, yet neither has it been studied for the expression of ER subtypes nor for the synthesis of the ERs in morphologically hetergeneous smooth muscle cells. Using nested RT-PCR, we have demonstrated the mRNA for ER-alpha splicing variants in intact human internal thoracic arteries. The 7A deletion variant occurred in 8 out of 12 cases, the full-length transcript in three cases. The full-length transcript was always found for the ER-beta. Immunolocalization revealed ER-positive nuclei in the desmin-positive subset of smooth muscle cells, but not in cytokeratin (CK)-positive cells of the thickened intima. Morphological evidence is presented suggesting that ER synthesis is high in the tunica media when cell proliferation of smooth muscle cells is increased. We conclude that, in internal thoracic arteries, the 7A deletion variant of ER-a occurs in 75%, whereas the full-length transcript is found in all cases. The significance remains unclear.

Relevancia de la anatomía humana en el ejercicio de la medicina de asistencia primaria y en el estudio de las asignaturas de segundo ciclo de la licenciatura en medicina / Relevance of Gross Human Anatomy in familiar medicine and in clinical disciplines of medical studies

El objetivo de este trabajo fue conocer la relevancia y la necesidad que de conocimientos en Anatomía macroscópica tenían los médicos de asistencia primaria y los alumnos de segundo ciclo de la licenciatura en Medicina. También nos interesó saber cual era su opinión sobre esta disciplina del curriculum médico. Para ello, médicos de asistencia primaria de los Centros de Salud de la provincia de las Palmas y alumnos de 6º curso de la Licenciatura en Medicina de la U.L.P.G.C., cumplimentaron un cuestionario en el que se valoraron los aspectos referidos. Ambos grupos consideraron que la Anatomía era fundamental para la exploración física y para la interpretación de técnicas de imagen. Los conocimientos más necesarios a la hora de su aplicación a la práctica y al estudio de las asignaturas clínicas fueron los de sistema nervioso y aparato locomotor. Modificarían la docencia que recibieron, incrementando el número de clases prácticas y dándole un mayor enfoque clínico. Los tres objetivos fundamentales de aprendizaje propuestos por los profesionales en ejercicio fueron: 1. Conocer las estructuras anatómicas y relaciones entre ellas 2. Reconocer estructuras anatómicas mediante técnicas de imagen y 3. Ser capaz de describir las bases anatómicas de la patología (AU)

Endothelial cell influence on dorsal root ganglion cell formation.

Although endothelial cells are known to produce neutrotrophic factors, endothelial cell influence on growth and survival of ganglion cells has not been documented. For this reason, a long-term culture technique was modified to obtain dorsal root ganglion (DRG) cells. Cells, among them neurons, were released from clusters into the medium for more than four weeks. These cells were grown together with endothelial cells either (1) in close contact as contiguous co-culture, or (2) on porous inserts for non-contiguous co-culture, and, finally, (3) without endothelial cells for ganglion cell culture. Samples from the cultures were stained for the nuclear Ki-67-antigen to detect proliferating cells, and for neurofilaments (NF) to verify the presence of DRG cells with and without mitotic figures. The contiguous co-culture contained three times as many mitotic DRG cells as other culture set ups. Nerve growth factor had no mitotic effect on the different DRG cultures, although it supported the growth of endothelial cells. It is concluded that a subpopulation of DRG cells is easily harvested from long-term DRG cultures. These DRG cells undergo mitosis when in direct contact with endothelial cells.