The mTOR pathway and transgenic animals with deletion of the TSC gene in the regeneration of the nervous system and selected models of sciatic nerve damage

Traumatic damage to the nervous system has been a common occurrence for years, reducing patients' quality of life. The mammalian target of rapamycin (mTOR) pathway plays a key role in nervous system physiology, including by controlling nerve cell survival and differentiation. Excessive activation of the mTOR pathway leads to an increase in cell cycle protein activity and apoptosis of nerve cells. Moreover, current findings suggest the involvement of the mTOR pathway in neuroplasticity. The use of transgenic animals with deletion of the TSC gene as well as various models of sciatic nerve damage, allows activation of the mTOR pathway. Currently, the results confirm that inactivation of point mutations in TSC-1 or TSC-2 genes, activates the canonical signaling pathway of the mTORC-1 complex, in turn, reactivation of the mTORC-1 pathway through the absence of the TSC-1 gene in mature neurons induces axonal regeneration. Dysfunction of the mTORC-1 pathway in Schwann cells (SC) inhibits myelination of nerve fibers. The aim of the present study is to understand the physiology and role of the mTOR pathway as well as to demonstrate the impact of TSC gene deletion in the regeneration of the nervous system. Current research on the activity of the mTOR pathway may provide new strategies to intensify peripheral nerve regeneration.

Assessment of metabolomics in patients with multiple sclerosis as an indicator of disease development, including relapsing-remitting, primary progressive and secondary progressive stage

Metabolomics is a scientific field whose topics include qualitative and quantitative analysis of metabolites, defined as the total set of low-molecular-weight chemical compounds not exceeding 1500 Da. Along with genomics, transcriptomics, and proteomics, it is categorized as a field of science, currently using state-of-the-art diagnostic tools that, in the face of modern medicine, allow a holistic approach to the patient. The presence of metabolites in the analyzed biological material, in contrast to the information contained directly in the genetic material, reflects the current physiological state of the cell, and represents an integral relationship between genotype and phenotype, which can directly contribute in the future to the knowledge of the molecular basis in specific disease entities. An additional aspect that is in favor of metabolic analysis is their decidedly smaller number compared to at least genes, transcriptomes, and proteins. Despite the development of many "omics" technologies, there is a lack of integrative and linking studies to see the full picture of cellular pathways in the future. Such linkage would improve our insight into human pathologies, leading to a revolution in preclinical and clinical research in disease diagnosis, prognosis, drug response and drug development.

Cerebral metabolism of glucose and selected glucose transporters in neurodegenerative diseases

Cerebral glucose metabolism is an issue of researchers’ interest for a long time. Disturbed transport and metabolism of glucose in the brain lead to development of numerous neurological pathologies. Recently, a significant correlation between perturbed cerebral glucose metabolism and development of neurodegenerative diseases has been shown. Glucose, a monosaccharide, is the main source of energy for brain cells. Brain is the organ which is the most sensitive to changes in blood glucose level. Perturbed glucose transport leads to disorders of the central glucose metabolism. Neurodegenerative diseases are defined in the literature as progressive and irreversible degeneration of nerve tissue, causing cell death as a result of degenerative processes. The aim of this article is to discuss the physiology and the role of selected glucose transporters in the development of neurodegenerative diseases: expression of selected GLUT1 and GLUT3 transporters in Alzheimer's and Huntington's diseases. Understanding of the cerebral glucose metabolism may be a crucial factor in fight with central nervous system diseases.

Application of peripheral nerve conduits in clinical practice: A literature review

Understanding the pathomechanisms behind peripheral nerve damage and learning the course of regeneration seem to be crucial for selecting the appropriate methods of treatment. Autografts are currently the gold standard procedure in nerve reconstruction. However, due to the frequency of complications resulting from autografting and a desire to create a better environment for the regeneration of the damaged nerve, artificial conduits have become an approved alternative treatment method. The aim of this mini-review is to present the nerve scaffolds that have been applied in clinical practice to date, and the potential directions of developments in nerve conduit bioengineering. Articles regarding construction and characterization of nerve conduits were used as the theoretical background. All papers, available in PubMed database since 2000, presenting results of application of artificial nerve conduits in clinical trials were included into this mini-review. Fourteen studies including ≤10 patients and 10 trials conducted on >10 patients were analyzed as well as 24 papers focused on artificial nerve conduits per se. Taking into consideration the experiences of the authors investigating nerve conduits in clinical trials, it is essential to point out the emergence of bioresorbable scaffolds, which in the future may significantly change the treatment of peripheral nerve injuries. Also worth mentioning among the advanced conduits are hybrid conduits, which combine several modifications of a synthetic material to provide the optimal regeneration of a damaged nerve.

Can we use thermal imaging to evaluate the effects of carpal tunnel syndrome surgical decompression?

Research is intended to verify if thermal imaging can be used in diagnosing and monitoring the carpal tunnel syndrome (CTS).This disease is not easy to diagnose using traditional methods. Also, the difficulties in monitoring carpal tunnel surgery effects necessitate new, noninvasive method, which gives more information.The research group consists of 15 patients with CTS and control group of healthy people. All patients who were examined before surgery were also tested 4 weeks after surgery, to check the effects of treatment. In addition a lot of our patients had or will have open carpel tunnel release surgery. Diagnosis of CTS was performed by thermal imaging in both hands from phalanges to the area of the wrist on the external and palmar side of the palm.Using infrared (IR) camera one can observe high temperature gradient on hand-tested areas and these differences prove the diagnosis. Moreover patients after surgery have better temperature distribution and it was closer to control group. Results prove that surgery is the best, and currently, the only method to treat CTS.Thermal imaging may be helpful in diagnosing CTS.

Endovascular Approach to Glomus Jugulare Tumors

Background

Paragangliomas are benign neuroendocrine tumors derived from the glomus cells of the vegetative nervous system. Typically, they are located in the region of the jugular bulb and middle ear. The optimal management is controversial and can include surgical excision, stereotactic radiosurgery and embolization.

Case Report

We report the endovascular approach to three patients harboring glomus jugulare paragangliomas. In all cases incomplete occlusion of the lesions was achieved and recanalization in the follow-up period was revealed. Two patients presented no clinical improvement and the remaining one experienced a transient withdrawal of tinnitus.

Conclusions

It is technically difficult to achieve complete obliteration of glomus jugulare tumors with the use of embolization and the subtotal occlusion poses a high risk of revascularization and is not beneficial in terms of alleviating clinical symptoms.

Variable spatial magnetic field influences peripheral nerves regeneration in rats

Generator of spatial magnetic field is one of most recent achievements among the magnetostimulators. This apparatus allows to obtain the rotating magnetic field. This new method may be more effective than other widely used techniques of magnetostimulation and magnetotherapy. We investigated the influence of alternating, spatial magnetic field on the regeneration of the crushed rat sciatic nerves. Functional and morphological evaluations were used. After crush injury of the right sciatic nerve, Wistar C rats (n = 80) were randomly divided into four groups (control and three experimental). The experimental groups (A, B, C) were exposed (20 min/day, 5 d/week, 4 weeks) to alternating spatial magnetic field of three different intensities. Sciatic Functional Index (SFI) and tensometric assessments were performed every week after nerve crush. Forty-eight hours before the sacrificing of animals, DiI (1,1'-di-octadecyl-3,3,3',3'-tetramethyloindocarbocyanine perchlorate) was applied 5 mm distally to the crush site. Collected nerves and dorsal root ganglia (DRG) were subjected to histological and immunohistochemical staining. The survival rate of DRG neurons was estimated. Regrowth and myelination of the nerves was examined. The results of SFI and tensometric assessment showed improvement in all experimental groups as compared to control, with best outcome observed in group C, exposed to the strongest magnetic field. In addition, DRG survival rate and nerve regeneration intensity were significantly higher in the C group. Above results indicate that strong spatial alternating magnetic field exerts positive effect on peripheral nerve regeneration and its application could be taken under consideration in the therapy of injured peripheral nerves.