Peripheral Nerve Structure Research Articles

Association of polymorphic variants of the GSTP1 and GSTM1 genes with signs of tunnel syndromes in patients with vibration disease (pilot study)

Introduction. The data on the association between GSTs gene variants and the risk of developing carpal tunnel syndrome (CTS) determine the feasibility of studying the relationship with changes in the nerve structure of the upper limbs identified by ultrasound examination in patients with vibration disease (VD). The aim of the study was to investigate the association of polymorphic variants of the GSTP1 and GSTM1 genes with signs of tunnel syndromes in VD patients. Materials and methods. Polymorphic variants of the GSTP1 (rs1695 and rs1138272) and GSTM1 genes in one hundred forty male VD patients were studied using PCR-RT method. High-resolution ultrasonography parameters were used to evaluate the morphological structure of the peripheral nerves of the upper limbs in patients, including the cross-sectional area (CSA) of the peripheral nerves. Results. A significant gain in CSA maximum of the median nerve was found in carriers of the GSTM1–/– genotype relative to those in the GSTM1+ polymorphic variant of the GSTM1 gene (p=0.014). At the same time, AG-GSTP1 (Ile105Val) heterozygote carriers were less resistant to vibration exposure compared to the AA homozygote ones. The AG carriers had a shorter period of vibration exposure (p=0.017), which was observed against the background of a pronounced tendency to a decrease in the period of vibration exposure at the time of VD diagnosis (p=0.034). Limitations. Limitations include the small number of examined patients and the analysis of associations of polymorphic variants of GSTs genes only with CSA values without taking into account the clinical and functional status of patients. Conclusion. The results obtained indicate that GSTs genes involved in protection against oxidative stress, may be associated with the development of CTS in VD patients. Further investigations are needed involving a larger number of VD patients with simultaneous analysis of the morphological structure of peripheral nerves, as well as of electrophysiological and clinical studies.

Ultrasound for pain interventions: peripheral nerve and musculoskeletal structures

Ultrasound for pain interventions: peripheral nerve and musculoskeletal structures

FK506 contributes to peripheral nerve regeneration by inhibiting neuroinflammatory responses and promoting neuron survival.

JOURNAL/nrgr/04.03/01300535-202507000-00031/figure1/v/2024-09-09T124005Z/r/image-tiff FK506 (Tacrolimus) is a systemic immunosuppressant approved by the U.S. Food and Drug Administration. FK506 has been shown to promote peripheral nerve regeneration, however, its precise mechanism of action and its pathways remain unclear. In this study, we established a rat model of sciatic nerve injury and found that FK506 improved the morphology of the injured sciatic nerve, increased the numbers of motor and sensory neurons, reduced inflammatory responses, markedly improved the conduction function of the injured nerve, and promoted motor function recovery. These findings suggest that FK506 promotes peripheral nerve structure recovery and functional regeneration by reducing the intensity of inflammation after neuronal injury and increasing the number of surviving neurons.

Preparation of bilayer tissue-engineered polyurethane/poly-L-lactic acid nerve conduits and their in vitro characterization for use in peripheral nerve regeneration

BackgroundDue to loss of peripheral nerve structure and/or function resulting from trauma, accidents, and other causes, peripheral nerve injuries continue to be a major clinical problem. These injuries can cause partial or total loss of sensory, motor, and autonomic capabilities as well as neuropathic pain. PNI affects between 13 and 23 out of every 100,000 people annually in developed countries. Regeneration of damaged nerves and restoration of function after peripheral nerve injury remain significant therapeutic challenges. Although autologous nerve graft transplantation is a viable therapy option in several clinical conditions, donor site morbidity and a lack of donor tissue often hinder full functional recovery. Biomimetic conduits used in tissue engineering to encourage and direct peripheral nerve regeneration by providing a suitable microenvironment for nerve ingrowth are only one example of the cutting-edge methods made possible by this field. Many innate extracellular matrix (ECM) structures of different tissues can be successfully mimicked by nanofibrous scaffolds. Nanofibrous scaffolds can closely mimic the surface structure and morphology of native ECMs of many tissues.MethodsIn this study, we have produced bilayer nanofibrous nerve conduit based on poly-lactic acid/polyurethane/multiwall carbon nanotube (PLA/PU/MWCNT), for application as composite scaffolds for static nerve tissue engineering. The contact angle was indicated to show the hydrophilicity properties of electrospun nanofibers. The SEM images were analyzed to determine the fiber’s diameters, scaffold morphology, and endometrial stem cell adhesion. Moreover, MTT assay and DAPI staining were used to show the viability and proliferation of endometrial stem cells.ResultsThe constructed bilayer PLA/PU/MWCNT scaffolds demonstrated the capacity to support cell attachment, and the vitality of samples was assessed using SEM, MTT assay, and DAPI staining technique.ConclusionsAccording to an in vitro study, electrospun bilayer PLA/PU/MWCNT scaffolds can encourage the adhesion and proliferation of human endometrial stem cells (hEnSCs) and create the ideal environment for increasing cell survival.

High serum prevalence of autoreactive IgG antibodies against peripheral nerve structures in patients with neurological post-COVID-19 vaccination syndrome.

Patients suffering from neurological symptoms after COVID-19 vaccination (post-COVID-19 vaccination syndrome (PCVS)) have imposed an increasing challenge on medical practice, as diagnostic precision and therapeutic options are lacking. Underlying autoimmune dysfunctions, including autoantibodies, have been discussed in neurological disorders after SARS-CoV-2 infection and vaccination. Here, we describe the frequency and targets of autoantibodies against peripheral nervous system tissues in PCVS. Sera from 50 PCVS patients with peripheral neurological symptoms after COVID-19 vaccination and 35 vaccinated healthy controls were used in this study. IgG autoreactivity was measured via indirect immunofluorescence assays on mouse sciatic nerve teased fibers. The frequencies of autoantibodies were compared between groups using Fisher's exact test. Serum anti-ganglioside antibodies were measured in ganglioside blots. Autoantibody target identification was performed using immunoprecipitation coupled to mass spectrometry. Subsequent target confirmation was conducted via cell-based assays and ELISA. Compared with controls, PCVS patients had a significantly greater frequency of autoantibodies against peripheral nervous system structures (9/50(18%) vs 1/35(3%); p=0.04). Autoantibodies bound to paranodes (n=5), axons (n=4), Schmidt-Lanterman incisures (n=2) and Schwann cell nuclei (n=1). Conversely, antibodies against gangliosides were absent in PCVS patients. Target identification and subsequent confirmation revealed various subunits of neurofilaments as well as DFS-70 as autoantibody epitopes. Our data suggest that autoantibodies against nervous system tissue could be relevant in PCVS patients. Autoantibodies against neurofilaments and cell nuclei with so far non-established links to this disease spectrum should be further elucidated to determine their biomarker potential.

Problems of diagnosis and treatment of chronic pain syndrome in patients with variants of the structure of peripheral nerves. A series of clinical cases

AIM: To assess the presence of variants of the structure of peripheral nerves as possible risk factors for chronic pain syndrome on the example of a series of clinical cases.
 MATERIALS AND METHODS: The systematization and analysis of data from domestic and foreign literature on pathophysiology, clinic, diagnosis and treatment of complex regional pain syndrome has been carried out. Research method: system analysis, presentation of a series of clinical cases.
 RESULTS: A series of clinical cases is presented. The main risk factors for chronic pain syndrome are presented. The conditions and diseases that need to be differentially diagnosed if complex regional pain syndrome is suspected are systematized: tunnel syndromes (carpal tunnel syndrome), diabetic polyneuropathy, HIV polyneuropathy, postherpetic neuralgia, neurogenic claudication/lumbar stenosis, central post-stroke pain, upper thoracic syndrome apertures.
 CONCLUSION: Today, practitioners and neurophysiologists are not sufficiently aware of the existence of interneural anastomoses and features, typical electroneuromyographic signs, as a result of which in most cases the obtained electroneuromyographic data are interpreted erroneously. Variants of the structure of nerves can give an incorrect clinical picture of the condition of peripheral nerves and lead to untimely diagnosis and treatment of chronic pain syndrome, complex regional pain syndrome. Improvements in diagnostic methods, as well as widely introduced high-tech examination methods, in particular electroneuromyography, magnetic resonance imaging and ultrasound, are helping to increase the frequency of detection of abnormalities in the structure of peripheral nerves. In the presented clinical cases, patients had structural variants that gave an incorrect clinical picture of the condition of the peripheral nerves and led to untimely diagnosis and treatment — the development of chronic pain syndrome.

Motor fiber function in spinal muscular atrophy-analysis of conduction velocity distribution.

The motor neuron survival protein, which is deficient in spinal muscular atrophy (SMA), performs numerous cellular functions. Currently, SMA is believed to be a multi-organ disease, including lesion of various structures of the central and peripheral nervous systems. Motor nerve damage, especially in milder SMA types, is controversial. This prompted the conduct of the electrophysiological studies in adults with SMA types 2 and 3 presented in this paper. The study group consisted of 44 adult patients with SMA types 2 and 3. All patients underwent neurological examination with Hammersmith Functional Motor Scale-Expanded (HFMSE) assessment. Standard electrophysiological studies in the ulnar nerve and conduction velocity distribution (CVD) tests were performed in all patients and controls. A prolongation of the distal latency and lowering of the motor potential amplitude with no changes in CVD were found in the whole patient group. There were no dependencies on the number of gene copies. Patients with low HFSME value had slower standard conduction velocity, CVD in upper and median quartiles, and narrower CVD spread; in milder SMA, CVD spread was greater than in controls. The significant reduction in motor response amplitude in SMA seems to be primarily related to motor neuron loss and directly proportional to its severity. The coexisting rearrangement in the peripheral nerve structure is present in SMA, and this could be partially caused by a coexisting demyelinating process. Nerve remodeling mainly affects large fibers and occurs in more severe SMA types with significant disability.

Electrospun Nanofibrous Conduit Filled with a Collagen-Based Matrix (ColM) for Nerve Regeneration.

Traumatic nerve defects result in dysfunctions of sensory and motor nerves and are usually accompanied by pain. Nerve guidance conduits (NGCs) are widely applied to bridge large-gap nerve defects. However, few NGCs can truly replace autologous nerve grafts to achieve comprehensive neural regeneration and function recovery. Herein, a three-dimensional (3D) sponge-filled nanofibrous NGC (sf@NGC) resembling the structure of native peripheral nerves was developed. The conduit was fabricated by electrospinning a poly(L-lactide-co-glycolide) (PLGA) membrane, whereas the intraluminal filler was obtained by freeze-drying a collagen-based matrix (ColM) resembling the extracellular matrix. The effects of the electrospinning process and of the composition of ColM on the physicochemical performance of sf@NGC were investigated in detail. Furthermore, the biocompatibility of the PLGA sheath and ColM were evaluated. The continuous and homogeneous PLGA nanofiber membrane had high porosity and tensile strength. ColM was shown to exhibit an ECM-like architecture characterized by a multistage pore structure and a high porosity level of over 70%. The PLGA sheath and ColM were shown to possess stagewise degradability and good biocompatibility. In conclusion, sf@NGC may have a favorable potential for the treatment of nerve reconstruction.

Integrating plasma metabolomics and gut microbiome to reveal the mechanisms of Huangqi Guizhi Wuwu Decoction intervene diabetic peripheral neuropathy

Ethnopharmacological relevanceHuangqi Guizhi Wuwu Decoction (HGWD) is a classic traditional Chinese herbal formula from “Synopsis of Golden Chamber,” which is used to treat blood stagnation and has been used for alleviating diabetic peripheral neuropathy (DPN) in the clinic. However, the mechanisms of HGWD intervention DPN are still to be discovered. Aim of the studyThis study aims to explore the mechanism of HGWD intervention DPN by integrating plasma metabolomics and gut microbiome. Materials and methodsBKS Cg-m+/+Leprdb/J (db/db) mice with DPN were at 16 weeks of age. The indices of DPN phenotypes in db/db mice, pathomorphology of the sciatic nerve, intraepithelial nerve fibers (IENF) of the foot pad, levels of blood lipids and oxidative stress, and inflammatory reaction were used to appraise the HGWD efficacy. Finally, the pharmacological mechanisms of HGWD intervening DPN were explored by metabolomics and 16S rRNA gene sequencing. ResultsHGWD reversed DPN phenotypes in db/db mice, improved peripheral nerve structure, ameliorated the level of blood lipids and nerve growth factor in plasma, enhanced antioxidant capacity, and alleviated inflammatory responses. Plasma metabolomics disclosed that HGWD remarkably regulated the unusual levels of thirty-seven metabolites involved in sphingolipid metabolism, biosynthesis of unsaturated fatty acids, arachidonic acid metabolism, and amino acid biosynthesis pathways. The gut microbiome showed that nine bacteria were highly correlated with the efficacy of HGWD in DPN. Integrating analysis of microbiome and metabolomics demonstrated that the interaction of four bacteria with four metabolic pathways might be the significant mechanism of HGWD intervention in DPN. ConclusionsThe mediation of gut microbiota and plasma metabolism may be the potential mechanism of HGWD ameliorating DPN in db/db mice. The interaction of Lactobacillus, Alloprevotella, Bacteroides, and Desulfovibio with four metabolic pathways might be the critical mechanism for HGWD treating DPN.

ЦЕНТРAЛЬНAЯ СЕНСИТИЗAЦИЯ ПРИ ПСOРИAТИЧЕСКOМ AРТРИТЕ

Introduction. Chronic pain consists of nociceptive, neuropathic and nociplastic components. Nociplastic pain based on central sensitization. Patients with central sensitization may experience severe pain even with no any signs of clinical and laboratory inflammation, and describe it in descriptors of neuropathic pain. The prevalence and influence of central sensitization in clinical and laboratory activity, the development of mood disorders in patients with psoriatic arthritis are not explored well. Aim. To assess the prevalence of central sensitization in patients with psoriatic arthritis, to compare the parameters of patients with and without central sensitization. Materials and methods. We examined 107 patients with psoriatic arthritis: number of tender and swollen joints, severity of pain, patient global assessment, and C-reactive protein were determined. Activity of disease was assessed with Disease activity in psoriatic arthritis, Ankylosing Spondylitis Disease Activity Score. Central sensitization was determined with Central Sensitization Inventory, presence of anxiety and depression - with Hospital Anxiety and Depression Scale. Descriptors of neuropathic pain were determined with Pain Detect Questionnaire. Statistical processing was carried out with Statistics 26.0. Differences were considered significant at p-value < 0.05. Results and discussion. Central sensitization was found in 46 (43%) patients – they had patient global assessment (p=0.004) and severity of pain (p=0.002) in higher values. The C-reactive protein (p=0.423), Disease activity in psoriatic arthritis (p=0.083) did not differ between groups, but the Ankylosing Spondylitis Disease Activity Score (p=0.002) was higher in patients with central sensitization. High prevalence of anxiety (25.2%) and depression (40.2%) was found; more often in patients with central sensitization (p=0.001 and p=0.004). Most of patients described the tactile allodynia, «electric shocks», and burning. Conclusion. Significant contribution of central sensitization to the persistence of pain in patients with psoriatic arthritis was found. The frequency of clinically significant anxiety and depression in patients with psoriatic arthritis was shown, as well as their higher prevalence among patients with central sensitization. Patients with psoriatic arthritis often described pain like neuropathic pain, which can indicate both local damage to the nervous system and the formation of pain sensitization without direct damage to peripheral nerve structures.

Immediate and short-term effects of eccentric muscle contractions on structural, morphological, mechanical, functional and physiological properties of peripheral nerves: A protocol for a systematic review and meta-analysis.

It is widely acknowledged that eccentric muscle contractions may cause skeletal muscle damage. However, there is little knowledge about the impact of eccentric contractions on non-muscular structures. Animal and human studies revealed that eccentric contractions can also induce immediate and short-term nerve dysfunction. The purpose of this review is to examine whether eccentric muscle contractions induce immediate and short-term effects on structural, morphological, mechanical, functional and physiological properties of peripheral nerves, from both animal and human studies. A systematic review of randomised (RCTs) and non-randomised controlled trials will be conducted. Four electronic databases (i.e., Medline/Pubmed, Science Direct, PEDro and Cochrane) will be searched using predefined search terms to identify relevant studies. Eligible studies have to comprise any type of eccentric contraction of upper or lower limb muscles. Primary outcomes will include measures related to structure, morphology, mechanical, functional and physiological properties of peripheral nerves. Two independent reviewers will assess eligibility, evaluate risk of bias, and extract relevant data. In human studies, the risk of bias will be assessed by the Cochrane Collaboration risk of bias tool (RoB 2.0 tool) for RCTs and by risk of bias in non-randomised studies of interventions (ROBINS-I) for non-randomised controlled trials; while for animal studies, the risk of bias will be assessed using the SYRCLE's RoB tool. A narrative synthesis will be conducted for all included studies. Also, if appropriate, a meta-analysis will be performed, where the effect size of each outcome will be determined by the standardized mean difference as well as the 95% confidence intervals. I2 statistics will be used to assess heterogeneity. For this study, no ethical approval is required. Findings will be disseminated widely through peer-reviewed publication and conference presentations. The protocol has been registered at the International Prospective Register of Systematic Reviews (PROSPERO). Registration number: CRD42021285767.

Facilitation of Cell Cycle and Cellular Migration of Rat Schwann Cells by O-Carboxymethyl Chitosan to Support Peripheral Nerve Regeneration.

O-carboxymethyl chitosan (CM-chitosan), holds high potential as a valuable biomaterial for nerve guidance conduits (NGCs). However, the lack of explicit bioactivity on neurocytes and poor duration that does not match nerve repair limit the restorative effects. Herein, CM-chitosan-based NGC is designed to induce the reconstruction of damaged peripheral nerves without addition of other activation factors. CM-chitosan possesses excellent performance in vitro for nerve tissue engineering, such as increasing the organization of filamentous actin and the expression of phospho-Akt, and facilitating the cell cycle and migration of Schwann cells. Moreover, CM-chitosan exhibits increased longevity upon cross-linking (C-CM-chitosan) with 1, 4-Butanediol diglycidyl ether, and C-CM-chitosan fibers possess appropriate biocompatibility. In order to imitate the structure of peripheral nerves, multichannel bioactive NGCs are prepared from lumen fillers of oriented C-CM-chitosan fibers and outer warp-knitted chitosan pipeline. Implantation of the C-CM-chitosan NGCs to rats with 10-mm defects of peripheral nerves effectively improve nerve function reconstruction by increasing the sciatic functional index, decreasing the latent periods of heat tingling, enhancing the gastrocnemius muscle, and promoting nerve axon recovery, showing regenerative efficacy similar to that of autograft. The results lay a theoretical foundation for improving the potential high-value applications of CM-chitosan-based bioactive materials in nerve tissue engineering.

Study of the nerve endings and mechanoreceptors of the medial meniscotibial ligament of the knee: A structural and distribution analysis

BackgroundThe aim of the present study is to describe the morphology and distribution of the nerve endings of the meniscotibial ligament (MTL) of the knee, in order to understand the interaction between the proprioceptive system and knee mechanics. MethodsTwenty medial MTLs were obtained from deceased organ donors. The ligaments were measured, weighed and cut. Sections (10 mm) were prepared on hematoxylin and eosin-stained slides for analysis of tissue integrity, and 50 mm sections were submitted to immunofluorescence with the protein gene product (PGP) 9.5 as primary antibody and Alexa Fluor 488 as secondary antibody, followed by microscopic analysis. ResultsThe medial MTL was identified in 100% of the dissections, with average length, width, thickness and weight of 7.07 ± 1.34 mm, 32.25 ± 3.09 mm, 3.53 ± 0.27 mm and 0.67 ± 0.13 g, respectively. The hematoxylin and eosin-stained histological sections exhibited typical ligament structure, with dense well-organized collagen fibers and vascular tissue. All the specimens analyzed contained type I (Ruffini) mechanoreceptors and free (type IV) nerve endings, varying from parallel to intertwined fibers. Nerve endings not classified with different irregular shapes were also found. Most type I mechanoreceptors were found close to the MTL insertions on the tibial plateau, while the free nerve endings were found adjacent to the capsule. ConclusionThe medial MTL showed a peripheral nerve structure, primarily type I and IV mechanoreceptors. These findings suggest that the medial MTL is important for proprioception and medial knee stabilization.

A Review of the Hybrid Description of Diabetes Mellitus

Elevated blood sugar levels, which are either brought on by inadequate insulin synthesis by the pancreas or by incorrect insulin usage by the body, characterize diabetes mellitus, a chronic metabolic disease. Diabetes mellitus can cause renal failure, and those with the condition are at least 10 times more likely to have to amputate a foot due to diabetes than those without it. High blood sugar levels are thought to contribute to kidney and heart problems. A rapid rate of beta cell malfunction and sequences resulting from an absolute lack of insulin hormone secretion may be used to describe type 1 diabetes mellitus. Type 1 diabetes mellitus often manifests itself in young patients, although it may also affect adults. Diabetic neuropathy, one of the most severe microvascular complications of diabetes mellitus, is characterized by a metabolic-vascular disorder that compromises the structure and function of peripheral somatic or autonomic nerves without inducing inflammation. Dehydration brought on by osmotic diuresis, which impacts hyperviscosity and a hypercoagulable condition, and elevated blood glucose levels are typical symptoms of a hyperosmolar hyperglycemic state. People with type 1 diabetes are 12 times more likely than those with type 2 diabetes to develop diabetic nephropathy.

Fluorescence imaging of peripheral nerve function and structure.

Peripheral nerve injuries are common and can cause catastrophic consequences. Although peripheral nerves have notable regenerative capacity, full functional recovery is often challenging due to a number of factors, including age, the type of injury, and delayed healing, resulting in chronic disorders that cause lifelong miseries and significant financial burdens. Fluorescence imaging, among the various techniques, may be the key to overcome these restrictions and improve the prognosis because of its feasibility and dynamic real-time imaging. Intraoperative dynamic fluorescence imaging allows the visualization of the morphological structure of the nerve so that surgeons can reduce the incidence of medically induced injury. Axoplasmic transport-based neuroimaging allows the visualization of the internal transport function of the nerve, facilitating early, objective, and accurate assessment of the degree of regenerative repair, allowing early intervention in patients with poor recovery, thereby improving prognosis. This review briefly discusses peripheral nerve fluorescent dyes that have been reported or could potentially be employed, with a focus on their role in visualizing the nerve's function and anatomy.

Homology in Structural and Functional Organization of the Fibrous Framework of the Derma and Paraneural Connective Tissue Components

Background: The recent increase in hostilities throughout the globe is one of the main factors that damage both the skin and peripheral nerves (PN), mainly of the upper and lower extremities. The duration of treatment of the injured limb and the rate of recovery of its functions are directly related to the structural integrity of the connective tissue (CT) sheath apparatus of the PN, which further actualizes the study of its micromorphological components. The structural integrity of the peripheral nerve includes not only the preservation of its conductive component but also the membranes surrounding it, providing complete morphofunctional unity. Thus, the study of the features of their tissue organization, vascularization and innervation, with the obligatory comparison of data with homologous tissue of different topography and possible extrapolation of data, determined the purpose of this work. The aim of this study was to analyze the dynamics of changes in the fibrous components of the paraneurium and dermis in onto- and phylogenesis under the influence of various factors and to compare the data obtained for their further extrapolation. Methods and Results: The study was conducted on mature male Wistar rats under standard vivarium conditions. The material for the study was the CT sheaths of the PN of the extremities and skin areas, 1x1 cm in size, to the depth of the subcutaneous fascia of animals. The cadaver material was taken on Days 1, 3, 7, 10, and 28 of ontogeny. The resulting biomaterial was fixed in a 10% buffered neutral formalin solution and embedded in paraffin, according to the standard method. Microtomized, the resulting histological sections were stained with hematoxylin and eosin, according to the method of Mallory and Van Gieson. A comprehensive morphological study was performed using light and electron microscopy. The study revealed the presence of two stages in the ontogeny of the CT, forming the dermis of the skin and paraneural CT structures of PN. In the first stage, structural elements are formed, considering the topography of the CT; in the second, they are differentiated, leading to a qualitative-quantitative transformation due to the appearance of a number of additional functions, an active period of body growth, and taking into account the action of various environmental factors. At earlier stages of ontogenesis, thin, flattened fibrous structures without a clear organization are observed in the field of view in the dermis of the skin. In the paraneurium, the components that form it are not sufficiently expressed. At later periods, the shape and architectonics of the fibrous component change, structurization and an increase in the thickness of the fibers occur and pronounced heterogeneity of the cellular component is observed.

Minimising complications and improving the success of peripheral regional blockade.

Peripheral regional blockade is a type of regional anaesthesia involving depositing local anaesthetics around a specific nerve or bundle of nerves that help transmit nociceptive signals to higher centres, such as the thalamus and somatosensory cortex. It is not only a widely used technique that provides surgical anaesthesia, but also acts as an essential part of the armamentarium against postoperative pain and pain following major skeletal trauma. This article discusses the structure and function of peripheral nerves, the classification and pathophysiology of peripheral nerve injury and, finally, how practising anaesthetists are committed to maximising success and minimising harm when performing peripheral nerve blockade in the operating theatre.

Modern MRI Diagnostics of Upper-Extremity-Related Nerve Injuries-A Prospective Multi-Center Study Protocol for Diagnostics and Follow Up of Peripheral Nerve Injuries.

(1) Background: Peripheral nerve injuries are severe injuries with potentially devastating impairment of extremity function. Correct and early diagnosis as well as regular regeneration observation is of utmost importance for individualized reconstruction and the best possible results. Currently, diagnoses and follow-up examinations are based on clinical examinations supported with electroneurography, which often causes delays in treatment and can result in impaired healing. However, there is currently no diagnostic device that can reliably correlate the anatomic–pathological parameters with the functional–pathological changes initially and during therapy. With new technologies such as MR neurography (MRN), precise visualization of potential nerve damage and visualization of the reinnervation processes is assumed to accelerate clinical decision making and accompaniment of individualized treatment. (2) Methods/Design: This prospective clinical study will examine 60 patients after peripheral nerve lesion aged 18–65 years from trauma timepoint onward. Patients should be observed over a period of 18–24 months with regular clinical examinations, electroneurography, and ultrasound to compare the potential of MRN to current gold-standard diagnostic tools. Furthermore, 20 patients with the same inclusion criteria stated above, with an internal fixation and osteosyntheses of humerus fractures, will be examined to determine the visibility of peripheral nerve structures in close proximity to metal. (3) Discussion: Peripheral nerve injuries are often accompanied with severe, expensive, and long-lasting impairment of extremity function. An early and precise diagnosis of the nerve lesion, as well as the healing course, is crucial to indicate the right therapy as soon as possible to save valuable time for nerve regeneration. Here, new technologies such as MRN aim to visualize nerve injuries on fascicular level, providing not only early diagnosis and therapy decisions, but also providing a precise tool for monitoring of reinnervation processes. As severe injuries of a nerve are often accompanied with bone fractures and internal fixation, we also aim to evaluate the visualization feasibility of nerves in close proximity to metal, and ultimately improve the outcome and extremity function of patients after a peripheral nerve injury.

Methacrylic acid-based biomaterials promote peripheral innervation in the subcutaneous space of mice

Peripheral nerve innervation is essential for regulating tissue repair and regeneration. MAA-based biomaterials have been previously shown to promote angiogenesis. Here we show a new role for MAA-based biomaterials in promoting terminal axon nerve growth. Our results demonstrate that MAA-based biomaterials promote peripheral nerve growth in an Igf-1 and Shh dependent manner. The resulting nerves increased the sensitivity of treated mice paws to nociception. iDISCO clearing showed that MAA increased the presence of peripheral nerve structures in whole explants. MAA was also able to increase the expression of key neuronal markers and growth factors in a peripheral neuropathy model, the diabetic db/db mouse, suggesting that MAA-based biomaterials may be relevant to treatment of peripheral neuropathy. Moreover, in a peripheral neuropathy model, MAA was able to up-regulate the expression of growth factors for an extended duration suggesting MAA may prevent degeneration through an effect on factors that promote survival. As all tissues are innervated, MAA-based biomaterials could have broad applications in the promoting regeneration and preventing degeneration of peripheral nerves.

Experimental models of vibration disease (literature review)

Introduction. Long-term vibration exposure to the human body is a risk factor for the development of occupational diseases and comorbid conditions causing, first of all, the pathology of the nervous system, as well as the cardiovascular, gastrointestinal tract and musculoskeletal systems. Pathogenetic aspects of vibration exposure at the molecular level remain open and require the search for adequate experimental animal models. The review describes experimental methods for studying vibration disease. A literature search was conducted in the databases MedLine, PubMed, Web of Science, Scopus, Google Scholar, CyberLeninka and RSCI. The results of experimental studies differ due to the difference in frequencies and duration of vibration exposure. Sanitary and hygienic characteristics of workplaces of coal-mining enterprises in Kuzbass. Data are given at the levels of local and whole-body vibration at the workplaces of an underground sinker, a stope miner, and a mining machine operator. Experimental modelling of local and whole-body vibration. Experimental methods of vibration exposure to laboratory rats, mice and rabbits at the local and whole-body levels are described. The presented experimental models are as close as possible to real vibration effects in production conditions. Vibration at frequencies above 4 Hz has been shown to cause changes in the structure and functions of peripheral vessels and nerves, along with hypoxic damage of the brain, heart, kidneys, liver, and skeletal muscles. Conclusion. Experimental modelling of vibration disease makes it possible to study the organ-specific molecular mechanisms of damaging vibration exposure to the body and develop effective preventive and therapeutic measures.