Transfer of the palmaris brevis motor branch to the thenar motor branch: A cadaveric preliminary study.

Objective: High median nerve injuries can lead to poor distal recovery, especially poor functioning of median innervated thenar muscles involved in thumb opposition and palmar abduction. The palmaris brevis (PB) is a small subcutaneous muscle innervated by ulnar nerve. Innervation of the PB is in most of cases provided by the ulnar digital nerve to the little finger.

New human in vitro co-culture model of keratinocytes and sensory neurons like cells releasing substance P with an evaluation of the expression of ZIKV entry receptors: A potent opportunity to test Zika virus entry and to study Zika virus' infection in neurons?

During the course of acute ZIKV infection, pruritus is a cardinal symptom widely documented in the literature. Its frequent association with dysesthesia and several dysautonomic manifestations, suggests a pathophysiological mechanism involving the peripheral nervous system. The aim of this study was to develop a functional human model to potentially able to be infected by ZIKV: by demonstrating the functionality on a new human model of co-culture of keratinocyte and sensory neuron derived from induced pluripotent stem cells using a classical method of capsaicin induction and SP release, and verify the presence of ZIKV entry receptor in these cells.

Basic mechanisms of itch.

Pruritus (or itch) is an unpleasant sensation leading to a desire to scratch. In the epidermis, there are selective C or Aδ epidermal nerve endings that are pruriceptors. At their other ends, peripheral neurons form synapses with spinal neurons and interneurons.

Anatomical contacts between sensory neurons and epidermal cells: an unrecognized anatomical network for neuro-immuno-cutaneous crosstalk.

Sensory neurons innervating the skin are conventionally thought to be the sole transducers of touch, temperature, pain and itch. However, recent studies have shown that keratinocytes - like Merkel cells - act as sensory transducers, whether for innocuous or noxious mechanical, thermal or chemical stimuli, and communicate with intraepidermal free nerve endings via chemical synaptic contacts. This paradigm shift leads to consideration of the whole epidermis as a sensory epithelium.

Merkel Cells Are Multimodal Sensory Cells: A Review of Study Methods.

Merkel cells (MCs) are rare multimodal epidermal sensory cells. Due to their interactions with slowly adapting type 1 (SA1) Aβ low-threshold mechanoreceptor (Aβ-LTMRs) afferents neurons to form Merkel complexes, they are considered to be part of the main tactile terminal organ involved in the light touch sensation. This function has been explored over time by , , , and approaches.

Do Merkel complexes initiate mechanical itch?

Itch is a common sensation which is amenable to disabling patients' life under pathological and chronic conditions. Shared assertion easily limits itch to chemical itch, without considering mechanical itch and alloknesis, its pathological counterpart. However, in recent years, our understanding of the mechanical itch pathway, particularly in the central nervous system, has been enhanced.

A re-innervated skin model of non-histaminergic itch and skin neurogenic inflammation: PAR2-, TRPV1- and TRPA1-agonist induced functionality.

Background: Skin, and epidermis, is innervated by sensory nerve fibres. Interactions between them and signal transduction are only partially elucidated in physiological/pathological conditions, especially in pruritus.

Objectives: To study the mechanisms involved in pruritus , we developed a skin explant model re-innervated by sensory neurons.

Sensitive Skin Syndrome: A Low-Noise Small-Fiber Neuropathy Related to Environmental Factors?

Background And Objectives: Patients frequently complain of mild, transient, unpleasant skin sensations that cannot be diagnosed as common neuropathies. Dermatologists have termed these symptoms "sensitive skin syndrome." This narrative review was performed for a better knowledge by other specialists.

Gastric cancer cell death analyzed by live cell imaging of spheroids.

Gastric cancer (GC) is the third cause of cancer-related mortality worldwide and is often diagnosed at advanced stages of the disease. This makes the development of more comprehensive models and efficient treatments crucial. One option is based on repurposing already marketed drugs as adjuvants to chemotherapy.

Chronic itch: emerging treatments following new research concepts.

Until recently, itch pathophysiology was poorly understood and treatments were poorly effective in relieving itch. Current progress in our knowledge of the itch processing, the numerous mediators and receptors involved has led to a large variety of possible therapeutic pathways. Currently, inhibitors of IL-31, IL-4/13, NK receptors, opioids and cannabinoids, JAK, PDE4 or TRP are the main compounds involved in clinical trials.

Biofabrication of a three dimensional human-based personalized neurofibroma model.

Neurofibromas are the most characteristic feature of neurofibromatosis type 1 (NF1), a multisystemic disorder caused by aberrations in the neurofibromin gene (NF1). Despite significant progress over the last several years in understanding this disease, a suitable in vitro model to better mimic neurofibroma formation and growth has yet to be described. There is therefore a need to establish an in vitro, three dimensional model that allows the incorporation of multicellular lineages and the modulation of the cellular microenvironment-known to be important for cellular crosstalk and distribution of soluble factors-to study neurofibroma biology and morphogenesis.

Neurological Disturbances of Ciguatera Poisoning: Clinical Features and Pathophysiological Basis.

Ciguatera fish poisoning (CFP), the most prevalent seafood poisoning worldwide, is caused by the consumption of tropical and subtropical fish contaminated with potent neurotoxins called ciguatoxins (CTXs). Ciguatera is a complex clinical syndrome in which peripheral neurological signs predominate in the acute phase of the intoxication but also persist or reoccur long afterward. Their recognition is of particular importance in establishing the diagnosis, which is clinically-based and can be a challenge for physicians unfamiliar with CFP.

Keratinocytes Communicate with Sensory Neurons via Synaptic-like Contacts.

Objective: Pain, temperature, and itch are conventionally thought to be exclusively transduced by the intraepidermal nerve endings. Although recent studies have shown that epidermal keratinocytes also participate in sensory transduction, the mechanism underlying keratinocyte communication with intraepidermal nerve endings remains poorly understood. We sought to demonstrate the synaptic character of the contacts between keratinocytes and sensory neurons and their involvement in sensory communication between keratinocytes and sensory neurons.

PAR2, Keratinocytes, and Cathepsin S Mediate the Sensory Effects of Ciguatoxins Responsible for Ciguatera Poisoning.

Ciguatera fish poisoning is caused by the consumption of fish contaminated with ciguatoxins (CTXs). The most distressing symptoms are cutaneous sensory disturbances, including cold dysesthesia and itch. CTXs are neurotoxins known to activate voltage-gated sodium channels, but no specific treatment exists.

Intra-epidermal nerve endings progress within keratinocyte cytoplasmic tunnels in normal human skin.

Intra-epidermal nerve endings, responsible for cutaneous perception of temperature, pain and itch, are conventionally described as passing freely between keratinocytes, from the basal to the granular layers of the epidermis. However, the recent discovery of keratinocyte contribution to cutaneous nociception implies that their anatomical relationships are much more intimate than what has been described so far. By studying human skin biopsies in confocal laser scanning microscopy, we show that intra-epidermal nerve endings are not only closely apposed to keratinocytes, but can also be enwrapped by keratinocyte cytoplasms over their entire circumference and thus progress within keratinocyte tunnels.

Lifting the veil on the keratinocyte contribution to cutaneous nociception.

Cutaneous nociception is essential to prevent individuals from sustaining injuries. According to the conventional point of view, the responses to noxious stimuli are thought to be exclusively initiated by sensory neurons, whose activity would be at most modulated by keratinocytes. However recent studies have demonstrated that epidermal keratinocytes can also act as primary nociceptive transducers as a supplement to sensory neurons.

Overexpression of certain transient receptor potential and Orai channels in prostate cancer is associated with decreased risk of systemic recurrence after radical prostatectomy.

Background: Several studies had suggested the potential role of calcium signaling in prostate cancer (PCa) prognosis and agressiveness. We aimed to investigate selected proteins contributing to calcium (Ca ) signaling, (Orai, stromal interaction molecule (STIM), and transient receptor potential (TRP) channels) and involved in cancer hallmarks, as independent predictors of systemic recurrence after radical prostatectomy (RP).

Methods: A case-control study including 112 patients with clinically localized PCa treated by RP between 2002 and 2009 and with at least 6-years' follow-up.

Role of Keratinocytes in Sensitive Skin.

Sensitive skin is a clinical syndrome defined by the occurrence of unpleasant sensations such as burning, stinging, tingling, pricking, or itching in response to various normally innocuous physical, chemical, and thermal stimuli. These particular symptoms have led the consideration of a potential dysfunction of the intra-epidermal nerve fibers (IENF) that are responsible for pain, temperature, and itch perception. This neuronal hypothesis has just been reinforced by recent studies suggesting that sensitive skin could become assimilated to small fiber neuropathy.

Cutaneous nociception: Role of keratinocytes.

Recent years have brought an enhanced understanding of keratinocyte contribution to cutaneous nociception. While intra-epidermal nerve endings were classically considered as the exclusive transducers of cutaneous noxious stimuli, it has now been demonstrated that epidermal keratinocytes can initiate nociceptive responses, like Merkel cells do for the innocuous mechanotransduction. In the light of recent in vivo findings, this article outlines this paradigm shift that points to a not yet considered population of sensory epidermal cells.

Intraepidermal nerve fibres are not the exclusive tranducers of nociception.

The goal of this article is to provide an insight of the most recent data on cutaneous nociception. Indeed recent studies have demonstrated that keratinocytes closely participate in sensory transduction, and therefore, intraepidermal free nerve endings are not exclusive transducers of pain. Therefore, the results of neurophysiological studies should be interpreted in the light of this information.

Immune effects of the neurotoxins ciguatoxins and brevetoxins.

Ciguatoxins (CTXs) and brevetoxins (PbTxs) are phycotoxins that can accumulate along the marine food chain and thus cause seafood poisoning in humans, namely "ciguatera fish poisoning" (CFP) and "neurotoxic shellfish poisoning" (NSP), respectively. CFP is characterized by early gastrointestinal symptoms and typical sensory disorders (paraesthesia, pain, pruritus and cold dysaesthesia), which can persist several weeks and, in some cases, several months or years. NSP is considered a mild form of CFP with similar but less severe symptoms.