Minimally Invasive Intradiscal Delivery of BM-MSCs via Fibrous Microscaffold Carriers

Current treatments of degenerated intervertebral discs often provide only temporary relief or address specific causes, necessitating the exploration of alternative therapies. Cell-based regenerative approaches showed promise in many clinical trials, but limitations such as cell death during injection and a harsh disk environment hinder their effectiveness. Injectable microscaffolds offer a solution by providing a supportive microenvironment for cell delivery and enhancing bioactivity. This study evaluated the safety and feasibility of electrospun nanofibrous microscaffolds modified with chitosan (CH) and chondroitin sulfate (CS) for treating degenerated NP tissue in a large animal model. The microscaffolds facilitated cell attachment and acted as an effective delivery system, preventing cell leakage under a high disc pressure. Combining microscaffolds with bone marrow-derived mesenchymal stromal cells demonstrated no cytotoxic effects and proliferation over the entire microscaffolds. The administration of cells attached to microscaffolds into the NP positively influenced the regeneration process of the intervertebral disc. Injectable poly(l-lactide-co-glycolide) and poly(l-lactide) microscaffolds enriched with CH or CS, having a fibrous structure, showed the potential to promote intervertebral disc regeneration. These features collectively address critical challenges in the fields of tissue engineering and regenerative medicine, particularly in the context of intervertebral disc degeneration.

Laser-Assisted Fabrication of Injectable Nanofibrous Cell Carriers

The use of injectable biomaterials for cell delivery is a rapidly expanding field which may revolutionize the medical treatments by making them less invasive. However, creating desirable cell carriers poses significant challenges to the clinical implementation of cell-based therapeutics. At the same time, no method has been developed to produce injectable microscaffolds (MSs) from electrospun materials. Here the fabrication of injectable electrospun nanofibers is reported on, which retain their fibrous structure to mimic the extracellular matrix. The laser-assisted micro-scaffold fabrication has produced tens of thousands of MSs in a short time. An efficient attachment of cells to the surface and their proliferation is observed, creating cell-populated MSs. The cytocompatibility assays proved their biocompatibility, safety, and potential as cell carriers. Ex vivo results with the use of bone and cartilage tissues proved that NaOH hydrolyzed and chitosan functionalized MSs are compatible with living tissues and readily populated with cells. Injectability studies of MSs showed a high injectability rate, while at the same time, the force needed to eject the load is no higher than 25 N. In the future, the produced MSs may be studied more in-depth as cell carriers in minimally invasive cell therapies and 3D bioprinting applications.

Three-Dimensional Printable Conductive Semi-Interpenetrating Polymer Network Hydrogel for Neural Tissue Applications

Intrinsically conducting polymers (ICPs) are widely used to fabricate biomaterials; their application in neural tissue engineering, however, is severely limited because of their hydrophobicity and insufficient mechanical properties. For these reasons, soft conductive polymer hydrogels (CPHs) are recently developed, resulting in a water-based system with tissue-like mechanical, biological, and electrical properties. The strategy of incorporating ICPs as a conductive component into CPHs is recently explored by synthesizing the hydrogel around ICP chains, thus forming a semi-interpenetrating polymer network (semi-IPN). In this work, a novel conductive semi-IPN hydrogel is designed and synthesized. The hybrid hydrogel is based on a poly(N-isopropylacrylamide-co-N-isopropylmethacrylamide) hydrogel where polythiophene is introduced as an ICP to provide the system with good electrical properties. The fabrication of the hybrid hydrogel in an aqueous medium is made possible by modifying and synthesizing the monomers of polythiophene to ensure water solubility. The morphological, chemical, thermal, electrical, electrochemical, and mechanical properties of semi-IPNs were fully investigated. Additionally, the biological response of neural progenitor cells and mesenchymal stem cells in contact with the conductive semi-IPN was evaluated in terms of neural differentiation and proliferation. Lastly, the potential of the hydrogel solution as a 3D printing ink was evaluated through the 3D laser printing method. The presented results revealed that the proposed 3D printable conductive semi-IPN system is a good candidate as a scaffold for neural tissue applications.

Repeat Administration of Bone Marrow-Derived Mesenchymal Stem Cells for Treatment of Amyotrophic Lateral Sclerosis

Background

The aim of this study was to investigate repeated intrathecal injection of autologous bone marrow-derived mesenchymal stem cells (BM-D MSCs) to patients for treatment of sporadic amyotrophic lateral sclerosis (ALS).

Material/Methods

Autologous MSCs were isolated from the patients’ bone marrow, plated, expanded, harvested, and passaged. Stem cells from a single bone marrow collection were used for 3 injections per patient, given over a 3-month period. Outcomes were measured with the Revised Amyotrophic Lateral Sclerosis Functional Rating Scale (ALSFRS-R). Participants were observed for a minimum of 6 months before transplantation to assess the natural course of ALS and for the same amount of time after transplantation to compare the rate of disease progression, estimated based on average monthly changes in ALSFRS-R scores. Data from 8 of the 15 participants eligible for the study were analyzed.

Results

The safety of the MSC injections was confirmed and various effects of the therapy were documented. In patients who had ALS with an inherently slow course, there were no significant changes in the rate of disease progression. In patients who had ALS with an inherently rapid course, slowing of the disease was noted following treatment with MSCs. However, because that subgroup was so small, it was not possible to assess whether the changes were statistically significant.

Conclusions

Identifying groups of patients who are not responding or potentially responding negatively to injection of MSCs may help prevent it from being offered to individuals who may not benefit from the therapy. One of the limitations of this treatment method is the amount of time required for long-lasting preparation of bone marrow-derived MSCs for a disease that is rapidly progressive. Therefore, it is worth looking for other allogeneic sources of stromal cells for these types of injections.

Immune Response to COVID-19: Can We Benefit from the SARS-CoV and MERS-CoV Pandemic Experience?

The global range and high fatality rate of the newest human coronavirus (HCoV) pandemic has made SARS-CoV-2 the focus of the scientific world. Next-generation sequencing of the viral genome and a phylogenetic analysis have shown the high homology of SARS-CoV-2 to other HCoVs that have led to local epidemics in the past. The experience acquired in SARS and MERS epidemics may prove useful in understanding the SARS-CoV-2 pathomechanism and lead to effective treatment and potential vaccine development. This study summarizes the immune response to SARS-CoV, MERS-CoV, and SARS-CoV-2 and focuses on T cell response, humoral immunity, and complement system activation in different stages of HCoVs infections. The study also presents the quantity and frequency of T cell responses, particularly CD4+ and CD8+; the profile of cytokine production and secretion; and its relation to T cell type, disease severity, and utility in prognostics of the course of SARS, MERS, and COVID-19 outbreaks. The role of interferons in the therapy of these infections is also discussed. Moreover, the kinetics of specific antibody production, the correlation between humoral and cellular immune response and the immunogenicity of the structural HCoVs proteins and their utility in the development of a vaccine against SARS, MERS, and COVID-19 has been updated.

Influence of Bone Marrow-Derived Mesenchymal Stem Cell Therapy on Oxidative Stress Intensity in Minimally Conscious State Patients

Neurological disorders, including minimally conscious state (MCS), may be associated with the presence of high concentrations of reactive oxygen species within the central nervous system. Regarding the documented role of mesenchymal stem cells (MSCs) in oxidative stress neutralization, the aim of this study is to evaluate the effect of bone marrow-derived MSC (BM-MSC) transplantation on selected markers of oxidative stress in MCS patients. Antioxidant capacity was measured in cerebrospinal fluid (CSF) and plasma collected from nine patients aged between 19 and 45 years, remaining in MCS for 3 to 14 months. Total antioxidant capacity, ascorbic acid and ascorbate concentrations, superoxide dismutase, catalase, and peroxidase activity were analyzed and the presence of tested antioxidants in the CSF and plasma was confirmed. Higher ascorbic acid (AA) content and catalase (CAT) activity were noted in CSF relative to plasma, whereas superoxide dismutase (SOD) activity and total antioxidant capacity were higher in plasma relative to CSF. Total antioxidant capacity measured in CSF was greater after BM-MSC transplantations. The content of ascorbates was lower and CAT activity was higher both in CSF and plasma after the administration of BM-MSC. The above results suggest that MSCs modulate oxidative stress intensity in MCS patients, mainly via ascorbates and CAT activity.

COMPLEX TREATMENT OF AMYOTROPHIC LATERAL SCLEROSIS PATIENT

Amyotrophic lateral sclerosis is a progressive and fatal degenerative neuromuscular disease with few if any treatment options and physical rehabilitation addressing specific deficits is the most frequent form of therapy. Patients also suffer from depression and increased anxiety. Our purpose was to assess the neurorehabilitation effectiveness in a patient with amyotrophic lateral sclerosis who underwent stem cell transplantation but refused physiotherapy due to depression. Disease progression was followed using the revised Amyotrophic Lateral Sclerosis Functional Rating Scale bimonthly for six months pre- and then post-stem cell transplantation. Psychological traits were assessed using six standardized tests. Quantitative electroencephalogram diagnostics was performed before the first and after the last neurofeedback session, and sessions were conducted on a 3-times-a-week basis. The physiotherapy protocol included proprioceptive neuromuscular facilitation, electrical modalities unit applied to the lumbar spine area, and breathing, relaxation and walking exercises, among others. Increased motivation and marked decrease in the pain level was associated with the patient's willingness to complete physiotherapy, which resulted in improvements in most neuromuscular deficits and in increased respiratory capacity. During the 12 post-rehabilitation months, progression of the disease decelerated, and a positive behavioral change was noted. The study suggested that neurofeedback could be used as a neurorehabilitation component of the personalized complex rehabilitation protocol in patients with amyotrophic lateral sclerosis.

Feline hip joint anatomy in magnetic resonance images

The aim of this study was to develop an anatomical model of the feline hip joint for low-field magnetic resonance imaging (LF-MRI) based on high-field magnetic resonance imaging (HF-MRI). The study was performed on six adult clinically healthy European shorthair cats, aged 1-3 years, with body weight of 2.8-4.4 kg. The animals were examined with the use of the Vet-MRI Grande Esaote LF (0.25 T) scanner and high-field Siemens Magnetom TRIO (3 T) MRI scanner. In the LF-MRI, most satisfactory results in T1-weighted images were obtained when TE was 26 ms in all three planes and when TR was 350-950 ms in the transverse plane, 950-1150 ms in the sagittal plane and 520-750 ms in the dorsal plane. In T2-weighted images, TE was 90 ms in the transverse and dorsal plane and 120 ms in the sagittal plane. The results were presented as images acquired with LF-MRI scanners in three planes. The slice thickness was 3 mm for each plane. In LF-MRI, muscles in the hip joint region and round ligament were well visualized. Unlike in LF-MRI, the cross section of the femoral nerve was identified in HF-MRI scans. In examinations of the feline hip joint, the main limitations of LF-MRI were a lack of reliable contrast between articular cartilage and synovial fluid as well as longer scan time. Despite the above, LF-MRI images were characterized by good contrast between bones and the surrounding soft tissues.

The Role of Glia in Canine Degenerative Myelopathy: Relevance to Human Amyotrophic Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by progressive degeneration of motor neurons and grim prognosis. Over the last decade, studies on neurodegenerative diseases pointed on the role of glia in supporting the proper function of neurons. Particularly, oligodendrocytes were shown to be essential through myelin production and supplying axons with energy metabolites via monocarboxylate transporters (MCT). We have used dogs with naturally occurring degenerative myelopathy (DM) which closely resembles features observed in human ALS. We have performed two types of analysis of spinal cord tissue samples: histology and molecular analysis. Histology included samples collected from dogs that succumbed to the DM at different disease stages, which were compared to age-matched controls as well as put in the context of young spinal cords. Molecular analysis was performed on spinal cords with advanced DM and age-matched samples and included real-time PCR analysis of selected gene products related to the function of neurons, oligodendrocytes, myelin, and MCT. Demyelination has been detected in dogs with DM through loss of eriochrome staining and decreased expression of genes related to myelin including MBP, Olig1, and Olig2. The prominent reduction of MCT1 and MCT2 and increased MCT4 expression is indicative of disturbed energy supply to neurons. While Rbfox3 expression was not altered, the ChAT production was negatively affected. DM in dogs reproduces main features of human ALS including loss of motor neurons, dysregulation of energy supply to neurons, and loss of myelin, and as such is an ideal model system for highly translational studies on therapeutic approaches for ALS.

Safety of intrathecal injection of Wharton's jelly-derived mesenchymal stem cells in amyotrophic lateral sclerosis therapy

Animal experiments have confirmed that mesenchymal stem cells can inhibit motor neuron apoptosis and inflammatory factor expression and increase neurotrophic factor expression. Therefore, mesenchymal stem cells have been shown to exhibit prospects in the treatment of amyotrophic lateral sclerosis. However, the safety of their clinical application needs to be validated. To investigate the safety of intrathecal injection of Wharton's jelly-derived mesenchymal stem cells in amyotrophic lateral sclerosis therapy, 43 patients (16 females and 27 males, mean age of 57.3 years) received an average dose of 0.42 × 10⁶ cells/kg through intrathecal administration at the cervical, thoracic or lumbar region depending on the clinical symptoms. There was a 2 month interval between two injections. The adverse events occurring during a 6-month treatment period were evaluated. No adverse events occurred. Headache occurred in one case only after first injection of stem cells. This suggests that intrathecal injection of Wharton's Jelly-derived mesenchymal stem cells is well tolerated in patients with amyotrophic lateral sclerosis. This study was approved by the Bioethical Committee of School of Medicine, University of Warmia and Mazury in Olsztyn, Poland (approval No. 36/2014 and approval No. 8/2016). This study was registered with the ClinicalTrials.gov (identifier: NCT02881476) on August 29, 2016.

MRI-guided intracerebral convection-enhanced injection of gliotoxins to induce focal demyelination in swine

Demyelinating disorders such as multiple sclerosis (MS) or transverse myelitis are devastating neurological conditions with no effective cure. Prevention of myelin loss or restoration of myelin are key for successful therapy. To investigate the disease and develop cures animal models with good clinical relevance are essential. The goal of the current study was to establish a model of focal demyelination in the brain of domestic pig using MRI-guided gliotoxin delivery. The rationale for developing a new myelin disease model in the domestic pig was based on the fact that the brain in pigs is anatomically and histologically much more similar to that of humans compared to the rodent brain. For MRI-assisted gliotoxin injection, eight 30 kg pigs were subjected to treatment with lysolecithin (20, 30 mg/ml); or with ethidium bromide (0.0125, 0.05, 0.2 mg/ml). Animals were placed in an MRI scanner for intraparenchymal targeting of gliotoxin into the corona radiata (250 μl over 1h), with real-time monitoring of toxin distribution on T1 scans and monitoring of lesion evolution over seven days using both T1 and T2 scans. After the last MRI, animals were transcardially perfused and brains were processed for histological and immunofluorescent analysis. Gadolinium-enhanced T1 MRI during injection demonstrated biodistribution of the contrast (as a surrogate marker for toxin distribution) and its diffusion through the brain parenchyma. Lesion induction was confirmed on T2-weighted MRI and histopathology, thus enabling the establishment of optimal doses of gliotoxins. To conclude, MRI-guided focal demyelination in swine is accurate and provides real-time confirmation of gliotoxin, thus facilitating placement of focal lesions with high precision. This new model of focal demyelination can be used for further investigation and development of novel therapeutic approaches.

Migration of human mesenchymal stem cells stimulated with pulsed electric field and the dynamics of the cell surface glycosylation

BACKGROUND

The analysis of the stem cells' glycome dynamics at different stages of differentiation and migration makes possible the exploration of the cell surface glycans as markers of the stem cell functional status, and, in the future, compatibility between transplanted cell and host environment.

OBJECTIVES

The objective of our study was to develop novel techniques of investigating cell motility and to assess whether the electric field of the therapeutic spinal cord stimulation system used in vivo contributes to the migration of human mesenchymal stem cells (hMSCs) in vitro.

MATERIAL AND METHODS

We have investigated the electrotaxis of bone marrow-derived MSCs using pulsed electric field (PEF) in the range of 16-80 mV/mm and the frequency of 130 Hz and 240 Hz. The PEF-related dynamics of the cell surface glycosylation was evaluated using 6 plant lectins recognizing individual glycans.

RESULTS

Pulsed electric field at physiological levels (10 mV/mm; 130 Hz) did not influence cellular motility in vitro, which may correspond to the maintenance of the transplanted cells at the lesion site in vivo. An increase of the PEF intensity and the frequency exceeding physiological levels resulted in an increase in the cellular migration rate in vitro. Pulsed electric field elevated above physiological intensity and frequency (40-80 mV/mm; 240 Hz), but not at physiological levels, resulted in changes of the cell surface glycosylation.

CONCLUSIONS

We found the described approach convenient for investigations and for the in vitro modeling of the cellular systems intended for the regenerative cell transplantations in vivo. Probing cell surface glycomes may provide valuable biomarkers to assess the competence of transplanted cells.

Therapeutic Potential of Stem Cells in Follicle Regeneration

Alopecia is caused by a variety of factors which affect the hair cycle and decrease stem cell activity and hair follicle regeneration capability. This process causes lower self-acceptance, which may result in depression and anxiety. However, an early onset of androgenic alopecia is associated with an increased incidence of the metabolic syndrome and an increased risk of the cardiac ischaemic disease. The ubiquity of alopecia provides an encouragement to seek new, more effective therapies aimed at hair follicle regeneration and neoregeneration. We know that stem cells can be used to regenerate hair in several therapeutic strategies: reversing the pathological mechanisms which contribute to hair loss, regeneration of complete hair follicles from their parts, and neogenesis of hair follicles from a stem cell culture with isolated cells or tissue engineering. Hair transplant has become a conventional treatment technique in androgenic alopecia (micrografts). Although an autologous transplant is regarded as the gold standard, its usability is limited, because of both a limited amount of material and a reduced viability of cells obtained in this way. The new therapeutic options are adipose-derived stem cells and stem cells from Wharton's jelly. They seem an ideal cell population for use in regenerative medicine because of the absence of immunogenic properties and their ease of obtainment, multipotential character, ease of differentiating into various cell lines, and considerable potential for angiogenesis. In this article, we presented advantages and limitations of using these types of cells in alopecia treatment.

CRISPR/Cas9 Technology as an Emerging Tool for Targeting Amyotrophic Lateral Sclerosis (ALS)

The clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein-9 nuclease (Cas9) is a genome editing tool that has recently caught enormous attention due to its novelty, feasibility, and affordability. This system naturally functions as a defense mechanism in bacteria and has been repurposed as an RNA-guided DNA editing tool. Unlike zinc-finger nucleases (ZFNs) and transcription activator-like effector nucleases (TALENs), CRISPR/Cas9 takes advantage of an RNA-guided DNA endonuclease enzyme, Cas9, which is able to generate double-strand breaks (DSBs) at specific genomic locations. It triggers cellular endogenous DNA repair pathways, contributing to the generation of desired modifications in the genome. The ability of the system to precisely disrupt DNA sequences has opened up new avenues in our understanding of amyotrophic lateral sclerosis (ALS) pathogenesis and the development of new therapeutic approaches. In this review, we discuss the current knowledge of the principles and limitations of the CRISPR/Cas9 system, as well as strategies to improve these limitations. Furthermore, we summarize novel approaches of engaging the CRISPR/Cas9 system in establishing an adequate model of neurodegenerative disease and in the treatment of SOD1-linked forms of ALS. We also highlight possible applications of this system in the therapy of ALS, both the inherited type as well as ALS of sporadic origin.

The feasibility of the CD271+ and CD271- mesenchymal stromal cell enrichment toward nucleus pulposus-like cells

INTRODUCTION

Factors promoting nerve cell ingrowth are considered responsible for chronic back pain resulting from the intervertebral disc degeneration (IDD). One of the recent exploratory IDD treatments is stem cell transplantation therapy. The CD271 (low-affinity nerve growth factor receptor) has been identified as a mark-er of the most homogeneous mesenchymal stem cell (MSC) subset. It is capable of promoting differentiation along adipogenic, osteogenic and chondrogenic lineages and producing significantly higher levels of cytokines as compared to the total population of plastic adherence-mesenchymal stem cells (PA-MSCs). We investigated the ability of CD271+ MSCs to differentiate into chondrocyte-like cells of the nucleus pulposus (NP) of intervertebral disc. We also examined CD271- MSCs, using PA-MSCs as a control cell population.

MATERIAL AND METHODS

Bone marrow derived PA-MSCs and its two subsets, CD271- MSCs and CD271+ MSCs, were seeded in collagen scaffolds. After two weeks of growth in NP-differentiation medium, RNA was isolated from cells-scaffold constructs and was analyzed by q-PCR for expression of NP markers. Glycosaminoglycans were analyzed biochemically directly in cells-scaffold constructs.

RESULTS

Expression of NP markers - extracellular matrix components such as aggrecan, collagen type II and glycosaminoglycans on both RNA and the protein levels - was significantly higher in CD271- MSCs compared to the CD271+ MSCs and PA-MSCs cell populations.

CONCLUSIONS

CD271- MSCs may be superior candidates for NP restorative treatment compared to CD271+ MSCs and PA-MSCs due to their ability of expressing NP-supporting extracellular matrix components at levels higher than the other two studied MSC subsets.

Real-time MRI for precise and predictable intra-arterial stem cell delivery to the central nervous system

Stem cell therapy for neurological disorders reached a pivotal point when the efficacy of several cell types was demonstrated in small animal models. Translation of stem cell therapy is contingent upon overcoming the challenge of effective cell delivery to the human brain, which has a volume ∼1000 times larger than that of the mouse. Intra-arterial injection can achieve a broad, global, but also on-demand spatially targeted biodistribution; however, its utility has been limited by unpredictable cell destination and homing as dictated by the vascular territory, as well as by safety concerns. We show here that high-speed MRI can be used to visualize the intravascular distribution of a superparamagnetic iron oxide contrast agent and can thus be used to accurately predict the distribution of intra-arterial administered stem cells. Moreover, high-speed MRI enables the real-time visualization of cell homing, providing the opportunity for immediate intervention in the case of undesired biodistribution.

Disseminated Pancreatic Neuroendocrine Neoplasm (NEN) with an Uncommon Localisation in the Central Nervous System. A Case Report

BACKGROUND

Neuroendocrine neoplasms (NEN) are rare neoplasms that originate from neuroendocrine cells and are characterized by the potential of hormonal activity. Approximately 70% of these tumours are located in the gastrointestinal system (GI), followed by the bronchi, endocrine glands-like C cells of the thyroid (medullary carcinoma), the parasympathetic and sympathetic system (paragangliomas, pheochromocytoma) and other very rare locations. The prevalence of cerebral metastases in neuroendocrine tumours is estimated by various authors to be approximately 1.5-5%. When the primary tumour is located in the pancreas, it is associated with a risk of cerebral metastases lower than 2%.

CASE REPORT

We describe a patient with a disseminated pancreatic NEN that presented with an isolated lesion in the brain. We gathered the important data via medical history,, observation, analysis of medical records, imaging and others diagnostic tests. Despite the fairly rare prevalence of cerebral metastases in NENs, a neurological work-up should be performed. This should include neuroimaging of the brain, preferably with MR, together with the somatostatin receptor scintigraphy (SRS), in each clinically suspicious case. A histopathological examination of the CNS tumour can confirm a dedifferentiation of NEN in the direction of a neuroendocrine carcinoma (NEC - neuroednocrine carcinoma) with a poor prognosis.

CONCLUSIONS

Cerebral metastases are diagnosed in 1.5-5% of patients with a neuroendocrine neoplasm. In each case suggestive of a dissemination into the central nervous system, MRI of the brain should be performed.

Stem cells for ALS: An overview of possible therapeutic approaches

Amyotrophic lateral sclerosis (ALS) is an unusual, fatal, neurodegenerative disorder leading to the loss of motor neurons. After diagnosis, the average lifespan ranges from 3 to 5 years, and death usually results from respiratory failure. Although the pathogenesis of ALS remains unclear, multiple factors are thought to contribute to the progression of ALS, such as network interactions between genes, environmental exposure, impaired molecular pathways and many others. The neuroprotective properties of neural stem cells (NSCs) and the paracrine signaling of mesenchymal stem cells (MSCs) have been examined in multiple pre-clinical trials of ALS with promising results. The data from these initial trials indicate a reduction in the rate of disease progression. The mechanism through which stem cells achieve this reduction is of major interest. Here, we review the to-date pre-clinical and clinical therapeutic approaches employing stem cells, and discuss the most promising ones.

Glial-restricted precursors as potential candidates for ALS cell-replacement therapy

Amyotrophic lateral sclerosis is a multifactorial progressive neurodegenerative disorder leading to severe disability and death within 3-5 years after diagnosis. The main mechanisms underlying the disease progression are poorly known but according to the current knowledge, neuroinflammation is a key player in motor neurons damage. Astrocytes constitute an important cell population involved in neuroinflammatory reaction. Many studies confirmed their striking connection with motor neuron pathology and therefore they might be a target for the treatment of ALS. Cell-based therapy appears to be a promising strategy. Since direct replacement or restoring of motor neurons using various stem cells is challenging, enrichment of healthy donor-derived astrocytes appears to be a more realistic and beneficial approach. The effects of astrocytes have been examined using transplantation of glial-restricted precursors (GRPs) that represent one of the earliest precursors within the oligodendrocytic and astrocytic cell lineage. In this review, we focused on evidence-based data on astrocyte replacement transplantation therapy using GRPs in animal models of motor neuron diseases. The efficacy of GRPs engrafting is very encouraging. Furthermore, the lesson learned from application of lineage-restricted precursors in spinal cord injury (SCI) indicates that differentiation of GRPs into astrocytes before transplantation might be more advantageous in the context of axon regeneration. To sum up, the studies of glial-restricted precursors have made a step forward to ALS research and might bring breakthroughs to the field of ALS therapy in the future.

MR monitoring of minimally invasive delivery of mesenchymal stem cells into the porcine intervertebral disc

Purpose

Bone marrow stem cell therapy is a new, attractive therapeutic approach for treatment of intervertebral disc (IVD) degeneration; however, leakage and backflow of transplanted cells into the structures surrounding the disc may lead to the formation of undesirable osteophytes. The purpose of this study was to develop a technique for minimally invasive and accurate delivery of stem cells.

Methods

Porcine mesenchymal stem cells (MSCs) were labeled with superparamagnetic iron oxide nanoparticles (SPIO, Molday ION rhodamine) and first injected into the explanted swine lumbar IVD, followed by ex vivo 3T MRI. After having determined sufficient sensitivity, IVD degeneration was then induced in swine (n=3) by laser-evaporation. 3 x 10⁶ SPIO-labeled cells embedded within hydrogel were injected in 2 doses using a transcutaneous cannula and an epidural anesthesia catheter. T2-weighted MR images were obtained at 3T before and immediately after cell infusion. Two weeks after injection, histological examination was performed for detection of transplanted cells.

Results

MSCs were efficiently labeled with Molday ION rhodamine. Cells could be readily detected in the injected vertebral tissue explants as distinct hypointensities with sufficient sensitivity. MR monitoring indicated that the MSCs were successfully delivered into the IVD invivo, which was confirmed by iron-positive Prussian Blue staining of the tissue within the IVD.

Conclusion

We have developed a technique for non-invasive monitoring of minimally invasive stem delivery into the IVD at 3T. By using a large animal model mimicking the anatomy of IVD in humans, the present results indicate that this procedure may be clinically feasible.

Three-dimensional morphometry of the A1 segment of the anterior cerebral artery with neurosurgical relevance

BACKGROUND

Despite research in the anatomical sciences for the last 200 years, some structures of the human body remain controversial or incompletely described. One of these structures is the A1 segment of the anterior cerebral artery (ACA).

OBJECTIVE

To analyze the A1 segment of the ACA using novel stereoscopic methods because the 3-dimensional morphometry of the ACA is important to neurosurgeons.

METHODS

A digital-image computer-based system was used to analyze the A1 segment of 230 ACAs derived from computed tomography. Data analysis included the inner diameter, length, and volume and calculation of A1 symmetry, hypoplasia, and deviation, and tortuosity indexes.

RESULTS

Hypoplasia of the A1 segment was found in 0.87% and only on the right sides, whereas asymmetry was found in 42.6% and was more common in female patients. Right A1 segments tended to be longer in male patients, and this reached significance. Also of significance was the correlation of an increased length with age. Right A1 segments tended to have greater volumes, and this was significant in a comparison of male and female patients. Tortuosity indexes tended to be greater for left sides, but deviation indexes tended to be greater on the right sides.

CONCLUSION

Morphometric data of the A1 segment of the ACA as analyzed in the present study may be of utility to the neurosurgeon. Right A1 segments tend to be more tortuous, more deviated, longer, and narrower than left A1 segments.

Detailed 3D-morphometry of the anterior communicating artery: potential clinical and neurosurgical implications

PURPOSE

Although a site common for pathology and of great importance to the neurosurgeon, the three-dimensional (3D) morphometry of the anterior communicating artery (ACoA) has had incomplete descriptions in the literature.

METHODS

Using a novel 3D digital-image computer data analysis system, 115 patients underwent evaluation of their ACoA based on DICOM files derived from CT angiography. Measurements included the length, internal diameter, volume, deviation index (DI) and tortuosity index (TI).

RESULTS

Of 115 samples, 85 were visualized clearly enough for morphometric analysis. The mean internal diameter was 1.86 mm and this tended to be greater in males (P < 0.05). The mean length of the ACoA was 3.99 mm and the mean volume was 11.61 mm(3). The mean TI for the ACoA was 0.84 and the mean DI was 0.62 mm. A significant relationship between DI and length, DI and volume, and DI and TI were found. The significant correlation of diameter to volume, and length related to volume, DI and TI, as well as TI related to length, volume and DI were noticed. There were no relationship between any parameter and age.

CONCLUSIONS

A detailed knowledge of the 3D-morphometry of the ACoA demonstrates that in almost 50% of individuals the ACoA is straight in their course. Detailed data regarding arterial topography and trajectory as found in our study may be also of use in detecting early changes in this vessel due to pathology and may assist in the treatment of vascular lesions and planning of neurosurgical or interventional radiological procedures in the region including ACoA aneurysms.

Three-dimensional morphometrical analysis of the M1 segment of the middle cerebral artery: potential clinical and neurosurgical implications

With an increase in the understanding of the formation and treatment of cerebral aneurysms and an improvement in imaging technology, actual standardized measurement values for the cerebral arteries are necessary. Therefore, the aim of this study was to provide a detailed assessment of the three-dimension (3D) morphology (vessel's curvature and trajectory) and 3D-morphometry of the M1 segment of the middle cerebral artery using computer tomography angiography (CTA) images. The DICOM files from CTA of 40 male and 75 female individuals with a mean age of 50.1 years were analyzed using an interactive postprocessing 3D volume-rendering algorithm. Specifically, the M1 segment was evaluated. Calculations included the length, internal diameter, volume, deviation (DI) and tortuosity indices (TI). The M1 segment had a mean internal diameter of 2.23 mm and was greater in men. M1 asymmetry was identified in 23.4% of the individuals and was more common in women. The mean length was 15.62 mm and the left M1 segments were a little longer. The mean volume of the M1 segments was 63.92 mm(3) , and this was typically greater in men and on the left sides. The mean TI and DI for the M1 segment were 0.91 and 2.17 mm, respectively. Therefore, the M1 segments are only slightly curved or straight in their course. In addition, the longest vascular M1 segments are more deviated (curved) and more tortuous. Such standardized data as presented herein may be useful in the preprocedural evaluation of patients with intracranial vascular pathology of the M1 segment.

Three-dimensional morphometry of the A2 segment of the anterior cerebral artery with neurosurgical relevance

Most prior morphometry data regarding the A2 segment of the anterior cerebral artery (ACA) have been based on cadaveric measurements. With newer imaging modalities, surgical techniques, and minimally invasive procedures, new standards for the anatomy of this vessel are necessary. A novel computer-based data system was used to analyze the three-dimensional (3D) morphometry of 230 A2 segments. In addition, tortuosity (TI) and deviation indices (DI) for this segment were calculated. The mean internal diameter of the A2 segment was 1.86 mm, and segments tended to be larger in men and on left sides. A2 segments were asymmetrical in 43%, and this was more common in women. Lengths tended to be greater on right sides and in men. Volumes were greater in men and increased with age, which was statistically significant. These gender differences were found to be statistically significant (P < 0.05), for both volume and diameter. TI was equal among sides, but DI was more often greater on right sides. The correlation coefficient ratio for length and DI was statistically significant. It is important to understand various 3D morphometrical differences particularly between genders. By constructing blood flow simulation models and during revascularization procedures, surgeons are able to gain a better understanding of each patient's vascular anatomy. These additional 3D data regarding the anatomy of the postcommunicating parts of the ACA may be useful to the neurosurgeon and interventional neuroradiologist. These data may assist with an earlier diagnosis of pathologies affecting the 3D morphology of the ACA.

Immunodetection of cocaine- and amphetamine-regulated transcript in the rumen, reticulum, omasum and abomasum of the sheep

Enteric nerves harbour a wide array of neuropeptides playing a key role in the regulation of gastrointestinal tract functions. In this study, the distribution patterns of cocaine- and amphetamine-regulated transcript-immunoreactive (CART-IR) nerve fibres as well as the percentages of CART-positive enteric neurons were immunohistochemically assessed in the rumen, reticulum, omasum and abomasum of the sheep. Double staining were applied, to elucidate whether neuropeptide Y (NPY), vasoactive intestinal polypeptide (VIP), substance P (SP), somatostatin or serotonin co-exist in CART-IR gastric structures. In the rumen, reticulum, omasum and abomasum, a majority of myenteric neurons identified by immunoreactivity to Hu C/D were CART-positive (47.1 +/- 3.6%, 45.1 +/- 3.0%, 41.6 +/- 2.6% and 40.9 +/- 2.9% respectively). The smooth musculature of the forestomachs as well as abomasum was innervated with numerous CART-IR nerve fibres. Blood vessels-associated CART-positive nerve terminals were identified in the submucosa of the reticulum only. Lamina muscularis mucosae of the omasum and abomasum was moderately innervated with CART-IR nerve terminals. In the abomasum sparse CART-IR nerve fibres were seen between mucosal glands. A small population of endocrine cells of the abomasum also exhibited the presence of CART. All neuronal elements as well as endocrine cells IR to CART were negative to somatostatin and/or serotonin. No immunoreactivity to VIP, NPY and/or SP was found in myenteric ganglia-projecting CART-positive nerve fibres. The co-localization of CART with VIP, NPY and/or SP was regularly observed in myenteric neurons as well as the smooth muscle layer- and lamina muscularis mucosae-projecting nerve fibres. CART-IR nerve terminals located between mucosal glands of the abomasum frequently co-stored VIP, NPY and/or SP. Although the exact function of CART in the ovine forestomachs/stomach has to be elucidated, several potential functions (like enteric nerves protection) have been suggested.

Early results of percutaneous laser disc decompression (PLDD) as a treatment of discopathic lumbar pain

Background. The purpose of this paper is to present the technique of percutaneous laser disc decompression (PLDD), give some indications for its use, and provide a preliminary evaluation of the clinical effectiveness of this procedure in the treatment of low back pain, based on the authors' own experience. Material and methods. We performed a prospective analysis of treatment outcome in 212 patients who received PLDD in our clinic between March 2003 and January 2004, and who reported for the planned follow-up examination. Results. In 79.2% of these cases we achieved resolution or significant reduction of pain, and this effect persisted throughout the observation period of 6 weeks post surgery. In 3.8% of our patients, transient improvement was followed by intensification of low back pain, associated with the appearance of the most common complication after PLDD: inflammation of the disk and adjacent fragments of the elastic lamina of the vertebral bodies. Conclusions. In most cases PLDD is not a genuine alternative to open surgery on lumbar discopathy. It is most often administered to patients who have chronic pain from a slight extrusion of the disc, typically not qualified for surgery as the treatment method of choice. All other patients, even with larger herniations, can be administered PLDD as a last attempt at minimally invasive treatment prior to surgery, provided there are no obvious features of disruption of the posterior longitudinal ligament.

Percutaneous laser lumbar disc decompression - mechanism of action, indications and contraindications

This article describes the development of minimally invasive methods in the treatment of lumbar discopathy, with particular attention to percutaneous laser disc decompression (PLDD). The authors discus the therapeutic operating mechanism of PLDD, emphasizing the importance of the thermal characteristics of laser light, which is responsible for the vaporization and ablation of a small amount of tissue from the nucleus pulposus. This causes a significant reduction in pressure in the closed structure of the disc, and consequently reduced compression exerted by the disk on the dural sac and the nerve roots. Improvement in the flow of cerebro-spinal fluid has also been observed on the level at which the operation is performed. On the basis of our own experience and the reports of other authors, we have specified indications and contra-indications for PLDD. Our conclusion is that PLDD is an effective treatment method for low back pain and ischialgia caused by protrusion or herniation of the nucleus pulposus, with elimination or significant reduction in symptoms in over 75% of those treated; reduction or resolution of neurological deficits that arise in the course of lumbar discopathy has also been observed. This method enables one-stage treatment of multi-level degenerative changes in the intervertebral disc. The only absolute contraindications for PLDD are the presence of sequestration, disturbances in blood coagulation, and bacterial infection.

Experimental aspects of cerebrospinal hemodynamics: the relationship between blood flow velocity waveform and cerebral autoregulation

The dynamic relationships among mean flow velocity, its pulsatile amplitude (FVa), cortical cerebral blood flow (CBF), and cerebral perfusion pressure (CPP) were studied in normal rabbits and rabbits with subarachnoid hemorrhage using 8-MHz pulsed transcranial Doppler ultrasound and hydrogen clearance under conditions of systemic hypotension and intracranial hypertension. A two-slope relationship was observed between FVa and CPP with a break point that correlated closely with the lower limit of CBF autoregulation in each animal. Below this CPP break point, FVa varied directly with CPP, and above the break point FVa varied inversely with CPP. In this experimental model, an inverse correlation between FVa and CPP indicates intact CBF autoregulation, whereas loss of that correlation implies exhaustion of autoregulatory reserve. Simultaneous recording and computation of FVa, CPP, and the correlation coefficient between FVa and CPP may be a means of monitoring CBF autoregulation in clinical practice.

A computer system for the identification of the cerebrospinal compensatory model

A computer system, based on IBM PC, was designed for the cerebrospinal compensatory model identification. The intracranial pressure (ICP) signal, registered during the lumbo-lumbar infusion test is analyzed by means of the spectral analysis algorithm in order to measure precisely the pulse wave amplitude. The amplitude and the mean ICP level, calculated repetetively within the period of about 8 seconds, are stored on the disk and form the basis for further model identification. Three different methods of identification were applied. They enable one to estimate the fundamental model parameters, such as: resistance to the cerebrospinal fluid resorption, pressure-volume index, baseline pressure, rate of formation of the cerebrospinal fluid. Statistical evaluation of the results of the infusion test analysis obtained by means of the system described in two groups of hydrocephalic patients (children and adults) is presented.

Comparison between classic-differential and automatic shunt functioning on the basis of infusion tests

Infusion tests were performed in order to examine cerebrospinal compensatory ability in two groups of patients with impaired compensation, subjected to shunt implantation. The functioning of the classic differential shunts was compared to the automatically (Orbis-Sigma) functioning shunts. The reference group, with intact compensatory parameters is also presented. The influence of different types of shunts on the intracranial compensation ability was compared. Automatic shunts produce less decrease in the resorption resistance of CSF in the post-shunted examination than the classic differential shunts. Classic differential shunts disturb the mono-exponential character of the pressure-volume relationship in a higher degree than automatic shunts. Shunt functioning models were proposed as well as the method of detection of eventual recovery to the normal resorption reserve. This method can be applied only to patients with automatic shunts.

The role of cerebrospinal compensatory parameters in the estimation of functioning of implanted shunt system in patients with communicating hydrocephalus (preliminary report)

Twelve patients presenting with communicating hydrocephalus were studied. In 9 cases where the mean ICP level remained below 10 mmHg the symptoms of normal pressure hydrocephalus were observed. All of the patients were treated by shunt system implantation. The clinical and psychological state, cranial computerized tomography and parameters of the cerebrospinal compensatory mechanisms, evaluated using the constant rate infusion test were compared before and after treatment. In most of the patients (11) the pathologically enlarged ventricles persisted. Only in three cases no clinical improvement was noticed. In this group the resistance to the cerebrospinal fluid absorption and the fluid formation rate were estimated as normal. In the group with improvement the normalization of the resistance (4), decrease in the cerebrospinal fluid formation rate (4) and decrease in the cerebrospinal system elasticity (1) can be pointed out as factors responsible for improvement manifested after shunting. Therefore the resorption resistance and the formation of cerebrospinal fluid should be considered as predictive factors in the shunt implantation in hydrocephalic patients, and play an important role in the diagnosis of this entity.

[Effect of stimulation of the spinal cord on phasic and tonic reflexes in patients with central motor neuron damage]

Spinal cord stimulation (SCS) is a method enabling the control of increased muscle tonus to be achieved in various spinal cord injuries. Polyelectromyographic (PEMG) methods were used for neurophysiological assessment of the degree of cord damage and persistent spinal reflexes as well as supramedullary influences. The analysed material comprised 40 PEMG records in 19 patients with spastic paraparesis or paraplegia after cord injury, cord tumour or multiple sclerosis. In 15 cases tentative epidural cord stimulation was done and 11 patients received implantation of a system for long-term stimulation. In most cases the epidural electrodes were implanted below the damaged segment, usually in the thoracic part of the cord. Before and after SCS beginning PEMG was done with a 16-channel Mingograph Siemens Elema with simultaneous recording of the responses from the symmetric muscles: quadriceps, semitendinous, adductor femoris, anterior tibialis and triceps surae. The effect of SCS was analysed on exteroceptive and proprioceptive reactions during testing of knee and ankle reflexes, and on the response of the muscles to vibration. In most patients a reduction was observed of the intensity of tendon reflexes, particularly the spread of the reflex to the contralateral extremity was no longer seen. The vibration reflex had a tonic character persisting in 48% of the studied muscles, even in patients with clinically complete transsection of the cord. The change of the character of monosynaptic reflexes and the presence of the vibration reflex suggest that SCS modifies the proprioceptive segmental spinal reactions.

[Post-traumatic intracerebral hematoma]

Fifty-five cases of post-traumatic intracerebral haematomas are analyzed, discussing the diagnostic value of such preliminary methods as plain skull films, EEG, echoencephalography. These methods, together with clinical findings make the diagnosis of intracerebral haematoma likely. The final diagnosis was based on carotid arteriography and computerized tomography of the brain, which provided additional information on traumatic brain damage. The diagnostic sensitivity of CT was higher. The considerable prognostic importance of the degree of consciousness disturbances and their duration is stressed. In the group of patients with lucidum intervallum the mortality was higher. Four patients were treated conservatively since CT demonstrated in them only small haematomas without displacement of the ventricles. The remaining patients were treated surgically removing the haematomas through craniotomy or craniectomy. In 54% of these cases improvement was obtained. The 33% mortality was moderate as compared with previous reports.

[Conservative treatment of selected cases of chronic paracerebral hematoma]

The authors report an analysis of the course of 16 cases treated conservatively for paracerebral haematomas. The diagnosis was based on angiographic findings of computerized tomography (CT). Haematoma resorption was confirmed by CT. The follow-up was from 3 months to 6 years. The patients were in a general good condition without or with only transient signs of focal central nervous system damage, the thickness of the haematomas was never over 15 mm. In all cases the haematomas were resorbed, 15 patients feel well and lead an active life, in one case signs of organic brain injury developed connected with dilatation of the ventricular system and cortico-subcortical atrophy. In the light of the observed material and a literature review criteria are suggested which could indicate expected good effects of conservative treatment in such cases.

[Treatment of trigeminal neuralgia by glycerol gangliolysis of the trigeminal ganglion]

Sixteen cases are reported treated with glycerol gangliolysis of Gasser's ganglion for trigeminal neuralgia. Glycerol was injected into Meckel's cavum from the percutaneous approach of Härtel with radiological monitoring. In the follow-up from 6 months to 2 years in 75% of cases no recurrence of neuralgia was observed. No complications were noted. The method seems to be particularly indicated in elderly patients and those with concomitant internal diseases in whom a decompressing operation in the area of the cerebellopontine angle is connected with greater risk.

[Secondary post-traumatic intracerebral hematomas]

Two cases are reported of post-traumatic intracerebral haematoma development several days after trauma, as demonstrated by serial computerized tomograms of the brain. In both cases the haematoma was removed surgically. The pathological mechanisms of such haematomas is analysed calling attention to the possibility of secondary bleeding appearance in foci of contusion of the brain. The importance is stressed of computerized tomography in the diagnosis of these post-traumatic complications.

[A case of tumor of the pineal body treated with gamma rays of Co-60]

A 21-year-old patients was admitted to hospital with symptoms suggesting a tumour in the area of the epiphysis. Computer tomography confirmed the initial diagnosis. Since signs were present of increased intracranial pressure a Pudenz valve was implanted and in the second stage of treatment radiotherapy with radioactive cobalt was applied. A very good result was obtained with control CT failing to demonstrate presence of the tumour and hydrocephalus.

Properties of mechanoreceptor afferent fibres in left inferior cardiac nerve

Single afferent fibres with receptive field in the heart chambers and great vessels were dissected from the thoracic sympathetic chain. The fibres were identified by the electrical stimulation of the left inferior cardiac nerve, which was left in continuity with the heart. Fifty-six percent of the afferent fibres from the left inferior cardiac nerve were spontaneously active, the rest was silent. The spontaneously active fibres with receptive field in the aorta or left ventricle fired in close relation to the cardiac cycle as revealed by constructing post-R-wave time histogram of their activity. Fibres with cardiac rhythmicity were all myelinated. The second group of the spontaneously active fibres had their receptive field in the left atrium. The activity of these fibres was slightly or not at all correlated with cardiac cycle. They were both myelinated fibres.