Inflammatory and immune responses in the cochlea: potential therapeutic targets for sensorineural hearing loss

The inner ear was previously assumed to be an immune-privileged organ due to the existence of its tight junction-based blood-labyrinth barrier. However, studies performed during the past decade revealed that the mesenchymal region of the cochlea, including its lateral wall, is a common site of inflammation. Neutrophils do not enter this region, which is consistent with the old dogma; however, bone marrow-derived resident macrophages are always present in the spiral ligament of the lateral wall and are activated in response to various types of insults, including noise exposure, ischemia, mitochondrial damage and surgical stress. Recent studies have also revealed another type of immune cell, called perivascular melanocyte-like macrophages (PVM/Ms), in the stria vascularis. These dedicated antigen-presenting cells also control vascular contraction and permeability. This review discusses a series of reports regarding inflammatory/immune cells in the cochlear lateral wall, the pathways involved in cochlear damage and their potential as therapeutic targets

Mapping of Notch signaling in the developing organ of Corti in common marmosets

IntroductionThe well-regulated development of the sensory epithelium is essential for hearing. This process involves the specification of a pro-sensory epithelium containing common progenitors that differentiate into hair and supporting cells. Notch signaling is one of the most critical pathways during these processes, and its modification is thought to be a feasible approach for treating hearing loss. Despite interspecies differences between rodents and primates or humans, most of our current knowledge regarding cochlear development has been obtained from rodent models.MethodsWe therefore examined and mapped the expression patterns of Notch signal components in the developing cochlea of the common marmoset (Callithrix jacchus), a small monkey species native to the New World, a primate model animal.ResultsIn contrast to the preserved expression patterns of the Notch signaling components in the hair cell differentiation between primates and rodents, we unveiled relatively large interspecies differences during the maturation of supporting cells.DiscussionThis improved knowledge of Notch signaling during primate cochlear development will facilitate the development of future regenerative therapies

Visualization of nerve fibers around the carotid bifurcation with use of a 9.4 Tesla microscopic magnetic resonance diffusion tensor imaging with tractography

BACKGROUND: Precise imaging of nerves have been challenging in the head and neck region, mainly due to low spatial resolution. Here, we investigated how nerves in the head and neck region could be visualized using an ultra-high magnetic field MR system. METHODS: We used formol-carbol-fixed human cadaveric necks and obtained MR diffusion tensor images (DTIs) using a 9.4 Tesla (T) ultra-high magnetic field MR system. Afterward, we prepared tissue sections and checked the anatomic relationships between the neurons and the carotid artery in order to confirm that the visualized fibers are indeed neuron fibers. RESULTS: We were able to identify nerves, including the vagus nerve, the hypoglossal nerve, and the spinal-accessory nerve. Hematoxylin-eosin stained histological sections confirmed neuron fibers in the same anatomic position. CONCLUSION: This technique has the feasibility to be applied for a more accurate anatomic understanding, maybe even close to a histological level

¿De vuelta a Los ocho años? A propósito de La guerra de Figueres, de Guillermo Villegas Hoffmaister

El libro de Guillermo Villegas Hoffmeister, “La guerra de Figueres”, tiene sin duda el subtítulo exacto Crónica de ocho años, porque eso es lo que es. Basado en alguna documentación escrita, en sus propios recuerdos personales y en una revisión de los periodos de la década de 1940, la obra se presenta ante todo como un producto de entrevistas realizadas por el autor a distintos personajes de la época. El resultado final es una narrativa descriptiva y parcializada, que combina alguna información interesante con datos sin importancia y algunas notables inexactitudes históricas: por ejemplo, el autor afirma que ¡el partido republicano nacional fue fundado por Maximiliano Fernández en 1909!, y en lo que parece ser producto de un lamentable descuido de él y de la EUNED, fecha la batalla de tejar el 13 de marzo en vez del 13 de abril de 1948…UCR::Vicerrectoría de Investigación::Unidades de Investigación::Artes y Letras::Centro de Investigación en Identidad y Cultura Latinoamérica (CIICLA

Location of a defect in a concrete block by a non-destructive technique

This paper describes a method to estimate the position of a crack in a concrete block using several vibration pick-ups. An array of vibration pick-ups is attached on the concrete block, and a vibration pulse is forced by using a small hammer. If there is a crack, a reflection wave is generated from the position of the crack. Therefore, conventional methods to estimate the position of vibration source seems to be useful for this purpose. However, since the concrete block is elastic, there are three wave propagation modes; the surface wave mode, the primary wave mode and the secondary wave mode. Since the necessary primary wave mode is not significant in magnitude, we cannot estimate the position by the conventional methods. To increase the S/N, we had already proposed a method to eliminate the first-coming surface wave. However, the method was insufficient to achieve a higher S/N. Therefore, this paper proposes a new method to achieve a better location of a crack. Some experiments were carried out, and good results were obtained