ABSTRACT
Sheep are recognized as useful species for translational neurodegeneration research, in particular for the study of Huntington disease. There is a lack of information regarding the detailed anatomy and connections of the basal ganglia of sheep, in normal myeloarchitectonics and in tract-tracing studies. In this work, the organization of the corticostriatal projections at the level of the putamen and globus pallidus (GP) are explored. For the first time, the myeloarchitectonic pattern of connections between the internal (IC) and the external (EC) capsules with the GP have been investigated in the sheep. Formaldehyde-fixed blocks of the striatum were treated with a metallic stain containing potassium dichromate and visualized using micro-CT (µ-CT). The trivalent chromium (Cr3+), attached to myelin phospholipids, imparts a differential contrast to the grey and white matter compartments, which allows the visualization of myelinated fascicles in µ-CT images. The fascicles were classified according to their topographical location in dorsal supreme fascicles (X, Y, apex) arising from the IC and EC; pre-commissurally, basal fascicles connecting the ventral part of the EC with the lateral zone of the ventral pallidum (VP) and, post-commissurally, superior (Z1 ), middle (Z2 ) and lower (Z3 ) fascicles, connecting at different levels the EC with the GP. The results suggest that the presumptive cortical efferent and afferent fibres to the pallidum could be organized according to a dorsal to ventrolateral topography in the sheep, similar to that seen in other mammals. The proposed methodology has the potential to delineate the myeloarchitectonic patterns of nervous systems and tracts.
Subject(s)
Chromates/chemistry , Globus Pallidus/anatomy & histology , Globus Pallidus/diagnostic imaging , Sheep/anatomy & histology , X-Ray Microtomography/veterinary , Animals , Male , Staining and Labeling/veterinaryABSTRACT
BACKGROUND: Extensor tendon disorders may cause severe functional impairments, and there is a lack of knowledge about their anatomic associations with the proximal fingernail matrix. OBJECTIVE: To delineate the association between the distal extensor pollicis longus tendon (EPLT) insertion and the limit of the fingernail matrix in the thumb. METHODS: The limit of the fingernail matrix and the distal bony insertion of the EPLT were identified in five thumbs from fresh-frozen human cadavers. An additional five thumbs were fixed and the longitudinal thumb sections were histologically analyzed. RESULTS: The terminal limit of the matrix and fingernail was dorsal and overlapped to the EPL tendon, which was located between the fingernail matrix and the phalanx, and extended dorsally to the distal section of the terminal phalanx in all ten thumb bodies. CONCLUSION: The fingernail matrix is not directly inserted into the periosteum of the dorsal section of the base to the distal phalanx, because this anatomic relationship is separated by the deep fibers of the EPLT.
ABSTRACT
Los huesos sesamoideos del primer metatarsiano no son tenidos siempre en consideración a la hora de realizar un diagnóstico, en las patologías que afectan a la región de la cabeza del primer metatarsiano. Ello es debido al escaso conocimiento de todas las entidades patológicas que pueden afectar a los sesamoideos y por la relativa poca incidencia que hasta el momento tienen. Con el aumento de las actividades de práctica deportiva, en concreto del running, cada vez se observan más afectaciones de índole clínica en esta región, relacionadas con este hueso. Métodos: Se realiza una búsqueda bibliográfica en 5 bases de datos (Medline, PubMed, Scopus, Cochrane Library y BUCea). Los términos empleados en la búsqueda fueron: sesamoids, anatomy, biomechanics, sesamoids review y sesamoids pathology. En la búsqueda inicial se tienen en cuenta los artículos con menos de 10 años, ceñidos a humanos y textos de revisión. Resultados: Se seleccionan 24 artículos que incluyen diferentes patologías con sus consiguientes diagnósticos mediante pruebas de imagen y tratamientos, tanto conservadores como quirúrgicos; así como aspectos de la biomecánica de la articulación metatarso-sesamoidea. Conclusión: Los sesamoideos debido a su anatomía, topografía y función pueden estar involucrados en un gran número de patologías; con signos y síntomas generalmente similares entre ellas y que pueden llevar al podólogo clínico a la confusión a la hora de realizar un diagnóstico y un tratamiento acertados (AU)
The first metatarsal sesamoid bones are not always taken into consideration when making a diagnosis, in pathologies that affect the region of the first metatarsal head. This is due to the insufficient knowledge of all the pathologies that can affect the sesamoids and the relative little incidence that they have. With the increment of sports activities, in particular the running, increasingly affects of the symptoms concerning this region are observed. Methods: A literature search was performed in 5 databases (Medline, PubMed, Scopus, Cochrane Library and BUCEA). The terms included in the search were: sesamoids, anatomy, biomechanics, sesamoids review and sesamoids pathology. In the initial search articles with no more than 10 years, only humans and revision texts are considered. Results: 24 articles were selected and include different pathologies with diagnosis using imaging tests and treatments, both conservative and surgical; as well as aspects from the biomechanics of the metatarsal-sesamoid joint. Conclusion: Sesamoids due of his anatomy, topography and function can be involved in a lot of pathologies; with similar signs and symptoms that can confuse the podiatry when he has to make a correct diagnosis or treatment (AU)