Fiber Counts Research Articles

Diffusion tensor imaging of superficial prefrontal white matter in healthy aging

The prefrontal cortex (PFC) is a heterogenous structure that is highly susceptible to the effects of aging. Few studies have investigated age effects on the superficial white matter (WM) contained within the PFC using in-vivo magnetic resonance imaging (MRI). This study used diffusion tensor imaging (DTI) tractography to examine the effects of age, sex, and intracranial volume (ICV) on superficial WM within specific PFC subregions, and to model the relationships with age using higher order polynomial regression modelling. PFC WM of 140 healthy individuals, aged 18–85, was segmented into medial and lateral orbitofrontal, medial prefrontal, and dorsolateral prefrontal subregions. Differences due to age in microstructural parameters such as fractional anisotropy (FA), axial and radial diffusivities, and macrostructural measures of tract volumes, fiber counts, average fiber lengths, and average number of fibers per voxel were examined. We found that most prefrontal subregions demonstrated age effects, with decreases in FA, tract volume, and fiber counts, and increases in all diffusivity measures. Age relationships were mostly non-linear, with higher order regressions chosen in most cases. Declines in PFC FA began at the onset of adulthood while the greatest changes in diffusivity and volume did not occur until middle age. The effects of age were most prominent in medial tracts while the lateral orbitofrontal tracts were less affected. Significant effects of sex and ICV were also observed in certain parameters. The patterns mostly followed myelination order, with late-myelinating prefrontal subregions experiencing earlier and more pronounced age effects, further supporting the frontal theory of aging.

Ultrahigh Fiber Count and High-Density Cables, Deployments, and Systems

Since the 1980s, the single-core optical fiber cable has been the essential data transmission wiring media, with ongoing increases in deployments. Its use case has broadened, with transmission distances ranging from meters to 10000s km, including intrabuilding, fiber-to-the-home (FTTH), terrestrial, and even submarine trunk lines. Currently, optical fiber cable deployment is strongly driven by cloud-based storage, X as a Service (XaaS), and worldwide data center (DC) functionality with the optical interconnection of massive servers on DC campuses. Hence, it is quite natural that the optical fiber cable industry has developed ultrahigh fiber count, high density, and small diameter optical fiber cable, e.g., 6912-fiber-count cable. With high-density cables, massive data capacity can be installed at one time while saving limited space in an underground duct. High-density cable designs have been developed not just by cable structure optimization but through the process of bundling fibers and the use of high-grade optical fibers. Moreover, many enabling technologies have been developed to support the deployment of ultrahigh fiber count cables, such as fiber identification, connectors, mass fusion splicing, and storage systems for fusion splicing points. In this article, state-of-the-art technologies and prospects for ultrahigh-count and ultrahigh-density optical fiber cables and enabling technologies are explained.

Anatomical distribution of CGRP-containing lumbosacral spinal afferent neurons in the mouse uterine horn.

Sensory stimuli from the uterus are detected by spinal afferent neurons whose cell bodies arise from thoracolumbar and lumbosacral dorsal root ganglia (DRG). Using an in vivo survival surgical technique developed in our laboratory to remove select DRG from live mice, we recently quantified the topographical distribution of thoracolumbar spinal afferents innervating the mouse uterine horn, revealed by loss of immunoreactivity to calcitonin gene-related peptide (CGRP). Here, we used the same technique to investigate the distribution of lumbosacral uterine spinal afferents, in which L5-S1 DRG were unilaterally removed from adult female C57BL/6J mice (N = 6). Following 10–12 days recovery, CGRP immunoreactivity was quantified along the length of uterine horns using fluorescence immunohistochemistry. Relative to myometrial thickness, overall CGRP density in uterine tissues ipsilateral to L5-S1 DRG removal was reduced compared to the DRG-intact, contralateral side (P = 0.0265). Regionally, however, myometrial CGRP density was unchanged in the cranial, mid, and caudal portions. Similarly, CGRP-expressing nerve fiber counts, network lengths, junctions, and the proportion of area occupied by CGRP immunoreactivity were unaffected by DRG removal (P ≥ 0.2438). Retrograde neuronal tracing from the caudal uterine horn revealed fewer spinal afferents here arise from lumbosacral than thoracolumbar DRG (P = 0.0442) (N = 4). These data indicate that, unlike thoracolumbar DRG, lumbosacral spinal afferent nerves supply relatively modest sensory innervation across the mouse uterine horn, with no regional specificity. We conclude most sensory information between the mouse uterine horn and central nervous system is likely relayed via thoracolumbar spinal afferents.

Brain structural connectome in neonates with prenatal opioid exposure.

IntroductionInfants with prenatal opioid exposure (POE) are shown to be at risk for poor long-term neurobehavioral and cognitive outcomes. Early detection of brain developmental alterations on neuroimaging could help in understanding the effect of opioids on the developing brain. Recent studies have shown altered brain functional network connectivity through the application of graph theoretical modeling, in infants with POE. In this study, we assess global brain structural connectivity through diffusion tensor imaging (DTI) metrics and apply graph theoretical modeling to brain structural connectivity in infants with POE.MethodsIn this prospective observational study in infants with POE and control infants, brain MRI including DTI was performed before completion of 3 months corrected postmenstrual age. Tractography was performed on the whole brain using a deterministic fiber tracking algorithm. Pairwise connectivity and network measure were calculated based on fiber count and fractional anisotropy (FA) values. Graph theoretical metrics were also derived.ResultsThere were 11 POE and 18 unexposed infants included in the analysis. Pairwise connectivity based on fiber count showed alterations in 32 connections. Pairwise connectivity based on FA values showed alterations in 24 connections. Connections between the right superior frontal gyrus and right paracentral lobule and between the right superior occipital gyrus and right fusiform gyrus were significantly different after adjusting for multiple comparisons between POE infants and unexposed controls. Additionally, alterations in graph theoretical network metrics were identified with fiber count and FA value derived tracts.ConclusionComparisons show significant differences in fiber count in two structural connections. The long-term clinical outcomes related to these findings may be assessed in longitudinal follow-up studies.

Reconstructing historical exposure to asbestos: the validation of 'educated guesses'.

In both the epidemiological and legal context, the causal attribution of asbestos-related lung diseases requires retrospective exposure assessment (REA). To assess the correlation between the retrospective assessment of occupational and anthropogenic environmental exposure to asbestos and its content in the lung tissue. Based on the available exposure information, a team of occupational physicians retrospectively assessed cumulative exposure to asbestos in 24 subjects who died of asbestos-related diseases. The asbestos lung content was analysed using analytical scanning electron microscope (SEM-EDS). The Log10 asbestos fibre count in the autoptic samples was predicted as a function of the Log10 estimated cumulative exposure using univariate regression analysis. The median count of asbestos fibres by grams of dry weight (ff/gdw) in the lung tissue was 81 339 (range 0-2 135 849.06); it was 287 144 (range 0-2 135 849.06) among the occupationally exposed, and 29 671 (range 0-116 891) among the subjects who only had anthropogenic environmental and/or household exposure. Amphiboles, and particularly amosite (52%) and crocidolite (43%), were detected in all the study subjects. Chrysotile was not detected in any of the samples. Overall, the retrospective estimate of lifetime cumulative exposure to asbestos showed a moderate correlation with the total asbestos fibre count in the autoptic lung, with the regression model explaining 38-55% of the total variance. Detailed information on occupational, environmental and household exposure circumstances would be indispensable for experienced industrial hygienists and/or occupational physicians to reliably assess past exposure to amphiboles or mixed types of asbestos.

An efficient virtual modeling regard to the axial tensile and transverse compressive behaviors of the twisted yarns

The mechanical properties of yarns have a decisive effect on the performance of fiber-reinforced composite materials. Predictive simulations of the mechanical response of yarns are, thus, necessary for damage evaluation and geometric reconstruction of textiles. This paper proposed a quasi-fiber scale virtual modeling method regard to the axial tensile and transverse compressive behaviors of the twisted yarns. A stochastic properties model of the yarn was established for characterizing the statistical distribution of tensile strength. The variation of modeling parameters, including coefficient of friction, the amounts of virtual fibers per yarn and element length, versus calculation accuracy has been determined based on axial tensile and transverse compressive behavior of quartz fibers. The relationship between modeling parameters and mechanical behavior of yarn was established within the scope of this study. Axial tensile and transverse compressive behavior of yarns with different twists were predicted. The results show that balance between the modeling precision and computational efficiency can be achieved using the parameters, the COF of 0.35, virtual fiber count of 122 and Le of 0.3. This efficient modeling method is meaningful to be developed in further virtual weaving research.

Association of clinical outcomes and connectivity in awake versus asleep deep brain stimulation for Parkinson disease.

Deep brain stimulation (DBS) for Parkinson disease (PD) is traditionally performed with awake intraoperative testing and/or microelectrode recording. Recently, however, the procedure has been increasingly performed under general anesthesia with image-based verification. The authors sought to compare structural and functional networks engaged by awake and asleep PD-DBS of the subthalamic nucleus (STN) and correlate them with clinical outcomes. Levodopa equivalent daily dose (LEDD), pre- and postoperative motor scores on the Movement Disorders Society-Unified Parkinson's Disease Rating Scale part III (MDS-UPDRS III), and total electrical energy delivered (TEED) at 6 months were retroactively assessed in patients with PD who received implants of bilateral DBS leads. In subset analysis, implanted electrodes were reconstructed using the Lead-DBS toolbox. Volumes of tissue activated (VTAs) were used as seed points in group volumetric and connectivity analysis. The clinical courses of 122 patients (52 asleep, 70 awake) were reviewed. Operating room and procedure times were significantly shorter in asleep cases. LEDD reduction, MDS-UPDRS III score improvement, and TEED at the 6-month follow-up did not differ between groups. In subset analysis (n = 40), proximity of active contact, VTA overlap, and desired network fiber counts with motor STN correlated with lower DBS energy requirement and improved motor scores. Discriminative structural fiber tracts involving supplementary motor area, thalamus, and brainstem were associated with optimal clinical improvement. Areas of highest structural and functional connectivity with VTAs did not significantly differ between the two groups. Compared to awake STN DBS, asleep procedures can achieve similarly optimal targeting-based on clinical outcomes, electrode placement, and connectivity estimates-in more efficient procedures and shorter operating room times.

Neurogranin inhibits calcineurin in murine soleus muscle: Effects of heterozygous knockdown on muscle adaptations to tenotomy and fatigue resistance

Neurogranin (Ng) is a calmodulin (CaM) binding protein that negatively regulates calcineurin - a Ca2+/CaM-dependent phosphatase that can mitigate the slow-to-fast fibre type shift observed with muscle unloading. Here, we questioned whether heterozygous deletion of Ng (Ng+/−) would enhance calcineurin activity, thereby minimizing the slow-to-fast fibre type shift caused by muscle unloading. As expected, soleus muscles from young adult (3–4 months old) Ng± mice had lowered Ng content and enhanced calcineurin activity when compared to soleus muscles obtained from male age-matched wild-type (WT) mice. Two weeks after tenotomy surgery, where the soleus and gastrocnemius tendons were severed, soleus total fibre count were found to be similarly reduced across both genotypes. However, significant reductions in myofibre cross-sectional area were only found in WT mice and not Ng± mice. Furthermore, while soleus muscles from both WT and Ng± mice exhibited a slow-to-fast fibre type shift with tenotomy, soleus muscles from Ng± mice, in both sham and tenotomized conditions, had a greater proportion of oxidative fibres (type I and IIA) compared with that of WT mice. Corresponding well with this, we found that soleus muscles from Ng± mice were more fatigue resistant compared with those obtained from their WT counterparts. Collectively, these findings show that heterozygous Ng deletion increases calcineurin activation, preserves myofibre size in response to unloading, and promotes the oxidative fibre type to ultimately enhance fatigue resistance. This study demonstrates the role of Ng in regulating calcineurin in vivo and its influence on skeletal muscle form and function.

Effect of neuroanatomy on corticomotor excitability during and after transcranial magnetic stimulation and intermittent theta burst stimulation.

Individual neuroanatomy can influence motor responses to transcranial magnetic stimulation (TMS) and corticomotor excitability after intermittent theta burst stimulation (iTBS). The purpose of this study was to examine the relationship between individual neuroanatomy and both TMS response measured using resting motor threshold (RMT) and iTBS measured using motor evoked potentials (MEPs) targeting the biceps brachii and first dorsal interosseus (FDI). Ten nonimpaired individuals completed sham‐controlled iTBS sessions and underwent MRI, from which anatomically accurate head models were generated. Neuroanatomical parameters established through fiber tractography were fiber tract surface area (FTSA), tract fiber count (TFC), and brain scalp distance (BSD) at the point of stimulation. Cortical magnetic field induced electric field strength (EFS) was obtained using finite element simulations. A linear mixed effects model was used to assess effects of these parameters on RMT and iTBS (post‐iTBS MEPs). FDI RMT was dependent on interactions between EFS and both FTSA and TFC. Biceps RMT was dependent on interactions between EFS and and both FTSA and BSD. There was no groupwide effect of iTBS on the FDI but individual changes in corticomotor excitability scaled with RMT, EFS, BSD, and FTSA. iTBS targeting the biceps was facilitatory, and dependent on FTSA and TFC. MRI‐based measures of neuroanatomy highlight how individual anatomy affects motor system responses to different TMS paradigms and may be useful for selecting appropriate motor targets when designing TMS based therapies.

Asbestos Lung Burden Does Not Predict Survival in Malignant Pleural Mesothelioma: A Necropsy-Based Study of 185 Cases

IntroductionMalignant pleural mesothelioma is an asbestos-related disease with poor survival. The prognostic role of histologic subtype is well established. Some studies (without a biological hypothesis) suggested that higher asbestos lung burden is associated with reduced survival. MethodsWe selected subjects from two series of necropsies: residents in Brescia province (North-West Italy) and workers (or persons living with them) employed in the Monfalcone shipyards (North-East Italy). Asbestos fibers and asbestos bodies in lung samples were counted using a scanning electron and an optical microscope, respectively. Separately in the two series, we analyzed median survival time and fitted multivariable Cox regression models (adjusted for sex, period and age at diagnosis, and histopatholocical diagnosis) to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for three levels of asbestos fiber counts (reference: <1 million fibers/g of dry lung tissue). ResultsWe analyzed 185 necropsies, 83 in Brescia and 102 in Monfalcone. Despite a much higher lung burden in Monfalcone patients, median survival was slightly shorter in Brescia (8.3 mo) than in Monfalcone (10.2 mo). In Brescia, medium (1.0–9.9) and high (10+) fiber burden HRs were 0.91 (95% CI: 0.54–1.53) and 1.23 (95% CI: 0.41–3.70), respectively. In Monfalcone, the corresponding HRs were 1.18 (95% CI: 0.59–2.35) and 1.63 (95% CI: 0.77–3.45), respectively. ConclusionsNo relationship between asbestos lung burden and survival was found. Histologic subtype was the strongest prognostic determinant.

Lake microbiome and trophy fluctuations of the ancient hemp rettery

Lake sediments not only store the long-term ecological information including pollen and microfossils but are also a source of sedimentary DNA (sedDNA). Here, by the combination of traditional multi-proxy paleolimnological methods with the whole-metagenome shotgun-sequencing of sedDNA we were able to paint a comprehensive picture of the fluctuations in trophy and bacterial diversity and metabolism of a small temperate lake in response to hemp retting, across the past 2000 years. Hemp retting (HR), a key step in hemp fibre production, was historically carried out in freshwater reservoirs and had a negative impact on the lake ecosystems. In Lake Slone, we identified two HR events, during the late stage of the Roman and Early Medieval periods and correlated these to the increased trophy and imbalanced lake microbiome. The metagenomic analyses showed a higher abundance of Chloroflexi, Planctomycetes and Bacteroidetes and a functional shift towards anaerobic metabolism, including degradation of complex biopolymers such as pectin and cellulose, during HR episodes. The lake eutrophication during HR was linked to the allochthonous, rather than autochthonous carbon supply—hemp straws. We also showed that the identification of HR based on the palynological analysis of hemp pollen may be inconclusive and we suggest the employment of the fibre count analysis as an additional and independent proxy.

Using an HDAC Inhibitor to Alter Muscle Growth in Fetal Pigs

A broad spectrum histone deacetylase (HDAC) inhibitor, butyrate, has been shown to promote increased myofiber size by altering satellite cell (SC) activity. The use of dietary supplementation of butyrate to affect muscle development has been hampered by its technical and pharmacokinetic properties. Most of these can be overcome with the use of tributyrin (TB), a butyrate prodrug. Dietary supplementation of TB was able to promote muscle growth by increasing myofiber size in neonatal pigs. We hypothesized that muscle growth during fetal development may be improved by increased fiber number through the dietary supplementation of TB to gestating sows. Nine sows of 53.6 ±1.08 gestational days (gd) were randomly assigned to one of three dietary treatment groups (n=3). These dietary treatments were a basal diet, basal diet + 1% TB, and the basal diet + 2% TB. All diets were made isocaloric with the addition of oil and wheat flour. Fetal piglets were removed at 107.6 ±1.5 gd. Weights and body lengths were recorded for all fetuses. Sections of Longissimus dorsi and Psoas major were collected from the median male, median female, the smallest, and the largest piglets of each litter and frozen for future histological analysis. Two novel methods for objective description of muscle fiber organization were evaluated, including fiber eccentricity (measure of elongation), and proportion of primary myofibers. The most significant difference in cross sectional area (CSA) was found within LD muscle with TB supplementation causing a significant reduction compared to control animals (p value &lt; 0.05). Fibers from 1% TB animals were significantly more elongated than control (p value &lt; 0.05). The proportion of primary to secondary myofibers was significantly higher in muscle from 2% TB treated piglets compared to control (p value &lt; 0.05). The smaller CSA together with a similar body weight across individual piglets (p &gt;0.05) suggest that TB supplementation increased myofiber number. The increased fiber count may be further supported by more elongated myofibers suggesting alterations to muscle fiber organization and an improved development of primary fibers. Further studies to elucidate the impact of TB supplementation during gestation and early postnatal life are warranted.

Effects of Curcumin and Tetracycline Gel on Experimental Induced Periodontitis as an Anti-Inflammatory, Osteogenesis Promoter and Enhanced Bone Density through Altered Iron Levels: Histopathological Study.

Adjunctive use of antimicrobials with scaling and root planing (SRP) is necessary to better eradicate dental biofilm. Tetracycline (T) is the most commonly used antimicrobial; however, it has limitations. This study evaluates the effect of curcumin (CU) as adjunct to SRP on inflammatory markers, collagen fiber deposition, and altered iron level. A total of 32 Wistar rats were divided into five groups: no experimental periodontitis (healthy control), experimental periodontitis (EPD), EPD treated with SRP alone (SRP), EPD treated with SRP+T (SRP+T), and EPD treated with SRP+CU (SRP+CU). After 2 and 4 weeks of treatment, tissue samples were assessed by hematoxylin and eosin, and special stains (Perls’ stain and Masson’s Trichrome) for counting of inflammatory cells, angiogenesis, collagen fibers, and iron deposition. Significant reductions in inflammatory cells infiltration and alveolar bone resorption with angiogenesis and collagen fibers deposition were detected after 2 and 4 weeks in both SRP+T and SRP+CU groups. SRP+CU resulted in a significant reduction in osteoclast numbers (week 2) and iron deposition (week 4) in bone trabeculae as compared to SRP and SRP+T groups. The adjunctive use of CU showed comparable results to T in the reduction in inflammation and bone resorption. Furthermore, CU has potential osteogenesis and healing effects.

Toward SDM-Based Submarine Optical Networks: A Review of Their Evolution and Upcoming Trends

Submarine networks have evolved alongside terrestrial ones over the past several decades. Although there are similarities between these two network categories (e.g., the need to cover ultra-long-haul distances and transport huge amounts of data), there are also important differences that have dictated their different evolutionary paths. Space division multiplexing (SDM) promises to be the ultimate solution to cover future capacity needs and overcome problems of both networks. In this work, we review recent and future submarine technologies, focusing on all critical sectors: cable systems, amplifiers’ technology, submarine network architectures, electrical power- feeding issues, economics, and security. Such an analysis, with the level of detail provided in this manuscript, is not available in the literature so far. We first overview all recently announced SDM-based submarine cable systems, compare their performance (capacity-distance product), and analyze the reasons that led to the first SDM submarine deployment. Also, we report up-to-date experimental results of submarine transmission demonstrations and perform a qualitative categorization that relies on their features. Moreover, based on all latest advances and our study findings, we try to predict the future of SDM submarine optical networks mainly in the fields of fiber types, fiber counts per cable, fiber-coating variants, modulation formats, as well as the type and layout structure of optical amplifiers. More specifically, results show that SDM can offer higher capacities (in order of Pb/s) compared to its counterparts, supported by novel network technologies: pump-farming amplification schemes, high counts up to 50 parallel fiber pairs, thinner fiber coating variants (200 μm), and optimum spectral efficiency (2–3 b/s/Hz). Finally, we conclude that tradeoffs between capacity and implementation complexity and cost will have to be carefully considered for future deployments of submarine cable systems.

Experimental Investigation on Strengthening of Soft Clay Brick Masonry Columns under Compression with Fiber-Reinforced Inorganic and Organic Matrixes

Masonry made with soft clay brick is commonly used in gravity load bearing of construction in India. The masonry piers and walls typically fail by vertical splitting. The purpose of this study is to improve the strength of masonry columns under compression using wrapping for additional confinement. The compressive load carrying performance and capacity of masonry columns wrapped with fiber reinforced composites in organic and inorganic matrixes are compared. For the purpose of overall improvements in cost and durability, glass and basalt fiber reinforcement is used. 30-40% improvement in the compressive performance of masonry prisms was achieved for both Organic and Inorganic matrixes. However, the specimens with inorganic matrixes were found to exhibit higher ductility compared to organic matrixes. Glass fibers were found to be more effective in wrapping masonry specimens compared to Basalt fiber specimens owing to its higher fiber count per unit length. Analytical models for predicting the compressive capacity of masonry columns with wrapping are verified against the experimental results.

Epilepsy-related white matter network changes in patients with frontal lobe glioma

PurposeEpilepsy is a common symptom in patients with frontal lobe glioma. Tumor-related epilepsy was recently considered a type of network disease. Glioma can severely influence the integrity of the white matter network. The association between white matter network changes and presurgical epilepsy remains unclear in glioma patients. This study aims to identify alterations to the subcortical brain networks caused by glioma and glioma-related epilepsy. MethodsSixty-one patients with frontal lobe gliomas were enrolled and stratified into the epileptic and non-epileptic groups. Additionally, 14 healthy participants were enrolled after matching for age, sex, and education level. All participants underwent diffusion tensor imaging. Graph theoretical analysis was applied to reveal topological changes in their white matter networks. Regions affected by tumors were excluded from the analysis. ResultsGlobal efficiency was significantly decreased (p = 0.008), while the shortest path length increased (p = 0.02) in the left and right non-epileptic groups compared to the controls. A total of five edges exhibited decreased fiber count in the non-epileptic group (p < 0.05, false discovery rate-corrected). The topological properties and connectional edges showed no significant differences when comparing the epileptic groups and the controls. Additionally, the degree centrality of several nodes connected to the alternated edges was also diminished. ConclusionsCompared to the controls, the epilepsy groups showed raletively intact WM networks, while the non-epileptsy groups had damaged network with lower efficiency and longer path length. These findings indicated that the occurrence of glioma related epilepsy have association with white matter network intergrity.

A Preliminary Study of the Efficacy of Transcranial Direct Current Stimulation in Trigeminal Neuralgia.

The purpose of this study is to assess the efficacy of transcranial direct current stimulation (tDCS) in patients with treatment-refractory trigeminal neuralgia (TN) and examine the utility of neuroimaging methods in identifying markers of such efficacy. Six patients with classical TN refractory to maximal medical treatment, underwent tDCS (three cases inhibitory/cathodic and three cases excitatory/anodic stimulation). All patients underwent pre- and posttreatment functional magnetic resonance imaging (fMRI) during block-design tasks (i.e., Pain, Pain + tDCS, tDCS) as well as single-shell diffusion MRI (dMRI) acquisition. The precise locations of tDCS electrodes were identified by neuronavigation. Five therapeutic tDCS sessions were carried out for each patient with either anodic or cathodic applications. The Numeric Rating Scale of pain (NRS) and the Headache Disability Index (HDI) were used to score the subjective efficacy of treatment. Altered activity of regional sites was identified by fMRI and associated changes in the spinothalamocortical sensory tract (STCT) were measured by the dMRI indices of fractional anisotropy (FA) and mean diffusivity (MD). Fiber counts of the bilateral trigeminal root entry zone (REZ) were performed as an added measure of fiber loss or recovery. All patients experienced a significant reduction in pain scores with a substantial decline in HDI (P value < 0.01). Following a course of anodic tDCS, the ipsilateral caudate, globus pallidus, somatosensory cortex, and the contralateral globus pallidus showed a significantly attenuated activation whereas cathodic tDCS treatment resulted in attenuation of the thalamus and globus pallidus bilaterally, and the somatosensory cortex and anterior cingulate gyrus contralaterally. dMRI analysis identified a substantial increase (>50%) in the number of contralateral sensory fibers in the STCT with either anodic or cathodic tDCS treatment in four of the six patients. A significant reduction in FA (>40%) was observed in the ipsilateral REZ in the posttreatment phase in five of the six patients. Preliminary evidence suggests that navigated tDCS presents a promising method for alleviating the pain of TN. Different patterns of activation manifested by anodic and cathodic stimulation require further elaboration to understand their implication. Activation and attenuation of responses at various sites may provide further avenues for condition treatment.

Effect of Neuroanatomy on Intermittent Theta Burst Stimulation Motor Evoked Potentials

<h3>Research Objectives</h3> Previous work noted that there are significant variabilities in motor response to intermittent theta-burst stimulation (iTBS). It is possible this variability results from individual neuroanatomical differences. The current objective was to investigate the effect of individual neuroanatomy on first dorsal interosseous (FDI) and biceps brachii motor evoked potentials (MEPs) in response to iTBS. <h3>Design</h3> Cross-sectional study using a convenience sample. <h3>Setting</h3> Research laboratory. <h3>Participants</h3> Ten healthy individuals (7 females, 23.5 ± 5 years) participated in this study. Participants completed two iTBS sessions (one each targeting the FDI and biceps cortical hotspots) and an MRI on separate days. <h3>Interventions</h3> Not applicable. <h3>Main Outcome Measures</h3> MEPs were calculated using data acquired with a Magstim Super Rapid2 Plus1 stimulator via a 70 mm double air film coil to the primary motor cortex and electromyography signals were measured from dominant FDI and biceps. Head models were generated from T1 & T2 weighted MRI. Diffusion tensor imaging was used to determine fiber tract geometry for FDI and biceps corticospinal tracts. We then established neuroanatomical parameters including: fiber tract surface area (FTSA), tract fiber count (TFC), and brain scalp distance (BSD). Cortical electric field strength (EFS) was calculated using simulated stimulation of head models and finite element analysis. <h3>Results</h3> For the FDI, there was no effect of iTBS (p = 0.223) but individual changes in corticomotor excitability scaled with stimulation type and resting motor potential (p < 0.001), EFS (p = 0.001), BSD (p = 0.004), and FTSA (p = 0.011). iTBS had a faciliatory response on the biceps and was dependent on FTSA (p < 0.001) and TFC (p < 0.001). <h3>Conclusions</h3> Our results show that MRI-based measures of neuroanatomy, specifically cortical architecture and tract anatomy, impact how the motor system responds to iTBS, subject to target-specific cortical control organization. MRI-based modeling of individual neuroanatomy may be a useful approach in selection of motor targets when designing iTBS-based therapies. <h3>Author(s) Disclosures</h3> None.

Effect of Neuroanatomy on Transcranial Magnetic Stimulation Resting Motor Thresholds

<h3>Research Objectives</h3> Previous research has demonstrated that anatomical complexities of cortical regions determine transcranial magnetic stimulation (TMS) induced electric fields in the brain, which impact the response to TMS-based therapies. The current objective was to investigate the effect of individual neuroanatomy on first dorsal interosseous (FDI) and biceps brachii resting motor thresholds (RMT) in response to TMS. <h3>Design</h3> Cross-sectional study using a convenience sample. <h3>Setting</h3> Research laboratory. <h3>Participants</h3> Ten healthy individuals (7 females, 23.5 ± 5 years) participated in this study. Each participant completed two TMS sessions (one each targeting the FDI and biceps cortical hotspots) and an MRI of the head on separate days. <h3>Interventions</h3> Not applicable. <h3>Main Outcome Measures</h3> RMTs were determined using a Magstim Super BiStim stimulator via a 70 mm figure-of-eight coil to the left primary motor cortex and electromyography signals were measured from right FDI and biceps. Head models were generated based on T1 & T2 weighted MRI, while diffusion tensor imaging was used to determine fiber tract geometry for FDI and biceps corticospinal tracts. Via the models, we established neuroanatomical parameters including: fiber tract surface area (FTSA), tract fiber count (TFC), and brain scalp distance (BSD). Cortical electric field strength (EFS) was calculated using simulated stimulation of head models and finite element analysis. <h3>Results</h3> For the FDI, RMT was dependent on the interaction between individually modeled parameters: 1) EFS and FTSA (p = 0.036), and 2) EFS and TFC (p = 0.004). For the biceps, RMT was dependent on the interaction between 1) EFS and FTSA (p = 0.022) and 2) EFS and BSD (p = 0.010). <h3>Conclusions</h3> Our study results show that MRI-based measures of neuroanatomy, specifically cortical architecture and tract anatomy, differentially impact how the motor system responds to TMS. MRI-based modeling of individual neuroanatomy may be a useful approach to select appropriate motor targets when designing TMS based therapies. <h3>Author(s) Disclosures</h3> None.

The role of intercellular mediators in the regulation of reparative processes of chronic wounds when using photobiomodulation therapy

Objective: The treatment of chronic wounds is one of the actual problems in medicine. Photobiomodulation (PBM) has gained considerable recognition among treatment modalities for various medical problems including wound repair processes. This research aims to investigate the role of intercellular mediators in the regulation of reparative processes of chronic wounds with the PBM therapy in the experiment. Methods: Studies were performed on 12 Wistar rats weighing 250 ± 30g. Rats were used for modeling a chronic wound. Animals were divided into two groups: control and experimental.The animal wounds from the experimental group were treated with low-intensity laser radiation from “Lika-therapist М” in continuous mode using a wavelength of 660 nm, output power at 50 mWt, energy density at 1 J/cm² once per day for 5 days. On the 14th day after the application of wounds, 6 rats from each group were removed from the experiment. PBM efficiency was evaluated with intercellular mediators analysis, as well as with histological examination. ELISA serum analysis was done for quantifying interleukin- 1β (IL-1β), tumor necrosis factor alpha (TNF-α), interleukin-4 (IL-4), interleukin-6 (IL-6), interleukin-10 (IL-10) and granulocyte macrophage colony stimulating factor (GM-CSF). Statistical processing of the results was performed using the Statistica 6.0 analysis package. Result: PBM effect on the expression of intercellular mediators in blood serum of animals with chronic wounds after 14 days after wound modeling, showed: increase of cytokine IL-1β (p &gt; 0,05) and IL-4 (p &lt; 0,05) levels; decrease of TNF-α and IL-10 levels (p &lt; 0,05); without significant changes were concentrations IL-6 and GM-CSF. The histological study showed decrease vascular count and better organization of collagen fibers in experimental group. Conclusion: Histological studies of wound healing revealed an earlier transition of the process to the remodeling phase with the use of PBM therapy. PBM therapy can be an instrument for optimizing the reparative process by correcting the regulation by intercellular mediators. Bangladesh Journal of Medical Science Vol. 21 No. 02 April’22 Page : 398-403