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Topic Review
Biography
Topic Review
Corneal Sensory Nerves
The cornea is an avascular connective tissue that is crucial, not only as the primary barrier of the eye but also as a proper transparent refractive structure. Corneal transparency is necessary for vision and is the result of several factors, including its highly organized structure, the physiology of its few cellular components, the absence of blood and lymphatic vessels in healthy conditions, the tightly controlled hydration state, and the lack of myelinated nerves, among others. The cornea is supplied by both sensory and autonomic nerves, being one of the most densely innervated tissues in the body. Corneal innervation is anatomically organized into four levels ranging from the nerve trunks in the corneal stroma to the nerve terminals in the epithelium. Electrophysiological recordings of corneal sensory nerve fibers have revealed the existence of three different functional types of sensory neurons that are classified into mechanonociceptors, polymodal nociceptors and cold thermoreceptors depending on the modality of stimuli by which they are activated. The impulse discharge is conducted by these neurons to the central nervous system, where sensory input is processed to finally evoke a sensation and to regulate ocular protective functions, such as tearing and blinking.
2.2K
21 Mar 2022
Topic Review
Spinal-Deformities and Advancement in Corrective-Orthoses
Spinal deformity is an abnormality in the spinal curves and can seriously affect the activities of daily life. The conventional way to treat spinal deformities, such as scoliosis, kyphosis, and spondylolisthesis, is to use spinal orthoses (braces). Braces have been used for centuries to apply corrective forces to the spine to treat spinal deformities or to stabilize the spine during postoperative rehabilitation. Braces have not modernized with advancements in technology, and very few braces are equipped with smart sensory design and active actuation. There is a need to enable the orthotists, ergonomics practitioners, and developers to incorporate new technologies into the passive field of bracing.
2.0K
30 Jan 2021
Topic Review
Vertebrate Cutaneous Sensory Corpuscles
Vertebrate cutaneous sensory corpuscles are specialized sensory nerve formations located in the skin of all vertebrates and responsible for tactile sensation. Functionally, they are mechanoreceptors transducing external mechanical stimuli into electrical signals which will be later led to the Central Nervous System. The afferent innervation of vertebrate skin is supplied by nerve fibers (Aβ, Aδ, C) which are originated from peripheral neurons localized in the dorsal root ganglia (DRG). Aβ nerve fibers end at the dermis level forming several morphotypes of sensory corpuscles with capacity of detecting different stimuli: Merkel cell–neurite complexes, Ruffini corpuscles, Meissner’s corpuscles and Pacinian corpuscles are present in the glabrous skin; while pilo-neural complexes are found in hairy skin. The structure of sensory corpuscles is formed by an axon, non-myelinating Schwann-like cells, a capsule of endoneurial and/or perineurial origin and extracelullar matrix molecules. The vertebrate skin contains sensory corpuscles that are receptors for different qualities of mechanosensitivity like light brush, touch, pressure, stretch or vibration. These specialized sensory organs are linked anatomically and functionally to mechanosensory neurons, which function as low-threshold mechanoreceptors connected to peripheral skin through Aβ nerve fibers. Furthermore, low-threshold mechanoreceptors associated with Aδ and C nerve fibers have been identified in hairy skin. The process of mechanotransduction requires the conversion of a mechanical stimulus into electrical signals (action potentials) through the activation of mechanosensible ion channels present both in the axon and the periaxonal cells of sensory corpuscles (i.e., Schwann-, endoneurial- and perineurial-related cells). Most of those putative ion channels belong to the degenerin/epithelial sodium channel (especially the family of acid-sensing ion channels), the transient receptor potential channel superfamilies, and the Piezo family.
1.7K
07 Sep 2020
Topic Review
Congenital Malformations in Sea Turtles
Congenital malformations can lead to embryonic mortality in many species, and sea turtles are no exception. Genetic and/or environmental alterations occur during early development in the embryo, and may produce aberrant phenotypes, many of which are incompatible with life. Causes of malformations are multifactorial; genetic factors may include mutations, chromosomal aberrations, and inbreeding effects, whereas non-genetic factors may include nutrition, hyperthermia, low moisture, radiation, and contamination. It is possible to monitor and control some of these factors (such as temperature and humidity) in nesting beaches, and toxic compounds in feeding areas, which can be transferred to the embryo through their lipophilic properties.
1.6K
22 Feb 2021
Topic Review
The Subconjunctival Space of the Eye
The subconjunctival space is the hydrophilic, fluid-filled space between the conjunctiva and the sclera. Additionally, the subconjunctival space has access to all the blood vessels found in the conjunctiva, which can help to further distribute substances throughout the whole eye. The subconjunctival space is located superior to the cornea and optimally located to distribute drugs to several different parts of the eye through minimally invasive means while limiting the development of scar tissue.
1.6K
05 May 2022
Topic Review
Mitochondrial Protein ATAD3A and Cancer
The ATPase family AAA-domain containing protein 3A (ATAD3A), a nuclear-encoded mitochondrial enzyme, contributes to mitochondrial dynamics, nucleoid organization, protein translation, cell growth, and cholesterol metabolism. The ATAD3A protein contains two coiled-coil domains (CC1 and CC2), Walker A (WA) and Walker B (WB) motifs and among them, the WA motif is responsible for ATP binding in the AAA module of ATAD3A. ATAD3A is an understudied protein in cancer, although we have demonstrated it functions as a metastasis promoter in breast cancer. At this stage of our understanding, ATAD3A dysfunction is also required and sufficient to drive oncogenic process in many types of cancer. Thus, there is a need to understand the mechanism by which ATAD3A interacts with other mitochondria-localized oncoproteins, and the targeting strategy in which ATAD3A is abrogated.
1.5K
12 Nov 2020
Topic Review
Biomechanical Factors in Track and Field Sprint Start
In athletics sprint events, the block start performance can be fundamental to the outcome of a race. Several biomechanical determinants of sprinters have been identified. In the “Set” position, an anthropometry-driven block setting facilitating the hip extension and a rear leg contribution should be encouraged. At the push-off, a rapid extension of both hips and greater force production seems to be important. After block exiting, shorter flight times and greater propulsive forces are the main features of best sprinters.
1.4K
13 Apr 2022
Topic Review
Blood-Brain Barrier: Functionalised Chitosan
The major impediment to the delivery of therapeutics to the brain is the presence of the blood-brain barrier (BBB). The BBB allows for the entrance of essential nutrients while excluding harmful substances, including most therapeutic agents; hence, brain disorders, especially tumors, are very difficult to treat. Chitosan is a well-researched polymer that offers advantageous biological and chemical properties, such as mucoadhesion and ease of functionalization. Chitosan-based nanocarriers (CsNCs) establish ionic interactions with the endothelial cells, facilitating the crossing of drugs through the BBB by adsorptive mediated transcytosis. This process is further enhanced by modifications of the structure of chitosan, owing to the presence of reactive amino and hydroxyl groups. Finally, by permanently binding ligands or molecules, such as antibodies or lipids, CsNCs have shown a boosted passage through the BBB, in both in vivo and in vitro studies which will be discussed in this review.
1.4K
21 Nov 2020
Topic Review
Bisphenols
Bisphenols (BPs), and especially bisphenol A (BPA), are known endocrine disruptors (EDCs), capable of interfering with estrogen and androgen activities, as well as being suspected of other health outcomes.
1.4K
28 Oct 2020
Topic Review
Mechanobiology of Chondrocytes
This entry is associated with a review article, published in MDPI Applied Sciences on 23 April 2020, about the current knowledge on the mechanical stimulation of mesenchymal stem cells for cartilage regeneration. Loading stresses, physiologically experienced by chondrocytes, regulate the production of glycosaminoglycan and collagen, as well as promote and preserve cell viability. Therefore, there is a rising interest in the development of devices that impose mechanical stimuli, such as compression and shear stress, on mesenchymal stem cells. The mentioned review will analyze the dynamics within the joint, the physiological stimuli experienced by the chondrocytes, and how the biomechanical stimulation can be applied to a stem cell culture in order to induce chondrogenesis. In addition to that, paper lists some of the current applications in the field.
1.2K
29 Oct 2020
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