An intra-cytoplasmic route for SARS-CoV-2 transmission unveiled by Helium-ion microscopy.

SARS-CoV-2 virions enter the host cells by docking their spike glycoproteins to the membrane-bound Angiotensin Converting Enzyme 2. After intracellular assembly, the newly formed virions are released from the infected cells to propagate the infection, using the extra-cytoplasmic ACE2 docking mechanism. However, the molecular events underpinning SARS-CoV-2 transmission between host cells are not fully understood.

A sciatic nerve gap-injury model in the rabbit.

There has been an increased number of studies of nerve transection injuries with the sciatic nerve gap-injury model in the rabbit in the past 2 years. We wanted to define in greater detail what is needed to test artificial nerve guides in a sciatic nerve gap-injury model in the rabbit. We hope that this will help investigators to fully exploit the robust translational potential of the rabbit sciatic nerve gap-injury model in its capacity to test devices whose diameter and length are in the range of those commonly applied in hand and wrist surgery (diameter ranging between 2 and 4 mm; length up to 30 mm).

Hoechst 33342 as a marker for imaging neurites of Dorsal Root Ganglion in vitro.

Fluorescent markers, generally targeting neurotubules, are used to visualize the radiating crown of growing neurites that is produced by dorsal root ganglion cells in vitro. Hoechst 33342 (2'-[4-ethoxyphenyl]-5-[4-methyl-1-piperazinyl]-2,5'-bi-1H-benzimidazole trihydrochloride trihydrate) is a widely used fluorescent DNA marker that stain both live and fixed nuclei. We have recently found that H33342 can visualize the neurites of DRG too, but only when they are fixed in formalin.

Wernicke's encephalopathy: An uncommon complication from hyperemesis gravidarum.

Hyperemesis gravidarum is a complication of pregnancy associated with severe nausea and vomiting that can lead to fluid-electrolyte imbalances and nutritional deficiencies. Wernicke's encephalopathy is a neurologic manifestation of acute thiamine (vitamin B1) deficiency. We describe a case of hyperemesis gravidarum presenting with gait ataxia and nystagmus which led to a diagnosis of Wernicke's encephalopathy.

A Flexor Digitorum Superficialis Tenodesis Technique for Surgical Treatment of Finger PIP Joint Volar Plate Chronic Avulsion.

Chronic, post-traumatic, avulsion of the proximal interphalangeal (PIP) joint volar plate represents a disabling lesion. The purpose of this report is to describe a flexor digitorum superficialis (FDS) tenodesis using a mini-bone anchor inserted into the proximal phalanx, and its clinical outcome. 15 patients with chronic post-traumatic hyperextension instability of the PIP joint were treated surgically.

A method to deliver patterned electrical impulses to Schwann cells cultured on an artificial axon.

Information from the brain travels back and forth along peripheral nerves in the form of electrical impulses generated by neurons and these impulses have repetitive patterns. Schwann cells in peripheral nerves receive molecular signals from axons to coordinate the process of myelination. There is evidence, however, that non-molecular signals play an important role in myelination in the form of patterned electrical impulses generated by neuronal activity.

Open Surgery for Trigger Finger Required Combined a1-a2 Pulley Release. A Retrospective Study on 1305 Case.

Objectives: We retrospectively reviewed 1305 open-surgery for idiopathic trigger finger performed by 4 senior hand surgeons between 2014 and 2016.

Material And Methods: Medical records and a telephone interview made with a minimum follow-up of 1 year were used to identify the recurrent rate of triggering and other complications.

Results: This retrospective study let us note that 169 fingers (13%) required simultaneous release of the A1-A2 pulleys because the sectioning of the A1 pulley alone did not lead to complete free sliding of the tendons.

Reciprocal nerve staining (RNS) for the concurrent detection of choline acetyltransferase and myelin basic protein on paraffin-embedded sections.

Background: Objective of our work was to develop a sequential double nonfluorescent immunostaining method which allows the selective identification of myelinated motor fibers in paraffin-embedded samples of peripheral nerves. Motor recovery after a nerve gap-lesion repaired by artificial nerve-guides ("conduits") is often less complete and slower than sensory recovery. The mechanism for this is not fully understood.

Trapeziometacarpal joint osteoarthritis: a prospective trial on two widespread conservative therapies.

Introduction: The trapeziometacarpal (TMC) joint osteoarthritis (OA) is at the origin of important secondary functional disability to pinch as well as a painful grip. Several conservative therapies are often considered in the early stages of TMC OA to decrease pain, recover function and slow the evolution of OA. They include massage therapy, heat applications, stretching of the first web span and assisted mobilization of the TMC joint.

"Ruffled border" formation on a CaP-free substrate: A first step towards osteoclast-recruiting bone-grafts materials able to re-establish bone turn-over.

Osteoclasts are large multinucleated giant cells that actively resorb bone during the physiological bone turnover (BTO), which is the continuous cycle of bone resorption (by osteoclasts) followed by new bone formation (by osteoblasts). Osteoclasts secrete chemotactic signals to recruit cells for regeneration of vasculature and bone. We hypothesize that a biomaterial that attracts osteoclasts and re-establishes BTO will induce a better healing response than currently used bone graft materials.

Development of a Device-Assisted Nerve-Regeneration Procedure in Disruptive Lesions of the Brachial Plexus.

Background:  We describe the development of a new surgical procedure to be used in the treatment of disruptive brachial plexus (BP) lesions. It is centered on an artificial device designed to assist nerve regeneration by providing a confined and protected environment. Nerve fibers can repair inside the device, while the adverse massive scar-tissue formation is limited to the outside of the device.

A suspended carbon fiber culture to model myelination by human Schwann cells.

Understanding of myelination/remyelination process is essential to guide tissue engineering for nerve regeneration. In vitro models currently used are limited to cell population studies and cannot easily identify individual cell contribution to the process. We established a novel model to study the contribution of human Schwann cells to the myelination process.

Debris of carbon-fibers originated from a CFRP (pEEK) wrist-plate triggered a destruent synovitis in human.

Application of carbon-fiber-reinforced-polymer (CFRP) artifacts in humans has been promoted in Orthopedic and Trauma Surgery. Literature documents the biocompatibility of materials used, namely carbon fibers (CF) and poly-ether thermoplastics, like poly-ether-ether-ketone (PEEK). A properly designed and accurately implanted composite artifact should not expose its fibers during or after surgery: however this may happen.

Peripheral nerve regeneration inside collagen-based artificial nerve guides in humans.

Purpose: Nerve gap injuries may be associated with lesions in other structures, like tendons or bones; in these cases, it is common to plan a second surgery to improve functional recovery. Since macroscopic observations of nerve regeneration in humans are rare, we exploited these second surgeries for the purpose of studying nerve regeneration in humans.

Methods: We assessed the clinical outcomes of 50 implants of collagen-based nerve guides in the upper limb.

A modified spica-splint in postoperative early-motion management of skier's thumb lesion: a randomized clinical trial.

Background: Rupture of ulnar collateral ligament of the thumb (UCL) represents a frequent injury of the hand. Surgical repair is considered the gold standard but postoperative immobilization causes partial stiffness in a percentage of cases.

Aim: The aim of this paper was to assess the effectiveness of a postoperative functional hand-based splint for the thumb which allows immediate postoperative motion.

Can we regrow a human arm? A negative perspective from an upper-limb surgeon.

If we would like to devote time and money to the task of regrowing a human arm, we should feel free to do it, in principle. However, if we recognize a purpose in biomedical research, we must scrutinize this task in the light of a possible clinical application. We will then discover that regrowing a human arm is not only likely to be not possible, but also not required in the clinic.

Persistence of abnormal electrophysiological findings after carpal tunnel release.

Practitioners may refer to experienced hand surgeons to differentiate a recurrence in carpal tunnel syndrome (CTS) from a failed carpal tunnel release. The patient may complain about the reappearance of symptoms, whatever is the cause. Nerve conduction studies (NCS) are often required by the practitioner to assist the final diagnosis.

A more detailed mechanism to explain the "bands of Fontana" in peripheral nerves.

Introduction: In 1779, Fontana identified transverse and oblique bands along peripheral nerves. Subsequent studies pointed alternatively to endoneural or perineural components as the cause. Our aim was to clarify these conflicting findings.

Combining an external fixator and an artificial nerve-guide for the treatment of a complex digital injury.

A complex digital injury, with tendon, nerve and bone losses, may pose the problem of which structure deserves the highest priority. Authors were able to treat tendon, nerve and bone lesions with the same level of priority thanks to the combined use of an external fixator and a nerve-guide.

Abductor pollicis longus hemitendon looping around the first intermetacarpal ligament as interposition following trapeziectomy: a one-year follow-up study.

Background: Trapeziectomy and ligament reconstructions are favoured by surgeons concerned that telescoping of the thumb may reduce its function. However, theoretically ligamentoplasties are at risk to develop tendinosis or tendon rupture or trigger a complex regional pain syndrome type 1.

Hypothesis: Authors tested the looping of a slip from the abductor pollicis longus (APL) tendon around the first intermetacarpal ligament.

Distal radius fractures: treatment using the Epibloc system.

The Epibloc system of percutaneous endomedullary internal fixation is best indicated for AO type A2-3 extra-articular fractures of the distal radius and AO type C1 slightly comminuted articular fractures. This system includes pins that can be inserted into the medullary canal and advanced without breaking through the second cortex. This fixation is stabilised by an external plate and rendered dynamic by the pins' elasticity which compresses the fractured surfaces.

In vivo study of ethyl-2-cyanoacrylate applied in direct contact with nerves regenerating in a novel nerve-guide.

Stitch suture is still the most recommended method to hold a nerve-guide in place but stitch suture is a well known cause of local inflammatory response. Glues of several kinds have been proposed as an alternative but they are not easy to apply in a real surgical setting. In 2006 authors developed a new concept of nerve-guide termed "NeuroBox" which is double-halved, not-degradable and rigid, and allows the use of cyanoacrylic glues.