Constant Stimulation Research Articles

A Quantitative Model of Sporadic Axonal Degeneration in the Drosophila Visual System.

In human neurodegenerative diseases, neurons undergo axonal degeneration months to years before they die. Here, we developed a system modeling early degenerative events in Drosophila adult photoreceptor cells. Thanks to the stereotypy of their axonal projections, this system delivers quantitative data on sporadic and progressive axonal degeneration of photoreceptor cells. Using this method, we show that exposure of adult female flies to a constant light stimulation for several days overcomes the intrinsic resilience of R7 photoreceptors and leads to progressive axonal degeneration. This was not associated with apoptosis. We furthermore provide evidence that loss of synaptic integrity between R7 and a postsynaptic partner preceded axonal degeneration, thus recapitulating features of human neurodegenerative diseases. Finally, our experiments uncovered a role of postsynaptic partners of R7 to initiate degeneration, suggesting that postsynaptic cells signal back to the photoreceptor to maintain axonal structure. This model can be used to dissect cellular and circuit mechanisms involved in the early events of axonal degeneration, allowing for a better understanding of how neurons cope with stress and lose their resilience capacities.SIGNIFICANCE STATEMENT Neurons can be active and functional for several years. In the course of aging and in disease conditions leading to neurodegeneration, subsets of neurons lose their resilience and start dying. What initiates this turning point at the cellular level is not clear. Here, we developed a model allowing to systematically describe this phase. The loss of synapses and axons represents an early and functionally relevant event toward degeneration. Using the ordered distribution of Drosophila photoreceptor axon terminals, we assembled a system to study sporadic initiation of axon loss and delineated a role for non-cell-autonomous activity regulation in the initiation of axon degeneration. This work will help shed light on key steps in the etiology of nonfamilial cases of neurodegenerative diseases.

The Antiarrhythmic Effect of Inhibition of the Mitochondrial Calcium Uniporter under Catecholamine Overload is Partly Dependent on Mitochondrial Function Preservation

IntroductionVentricular arrhythmias are a major cause of mortality in cardiovascular patients. Catecholamines have been associated with the development of ventricular arrhythmias and no new intervention has demonstrated efficacy in reducing mortality since the use of β‐blockers. Mitochondrial calcium transport has been deemed necessary for an adequate adrenergic response and constant adrenergic stimulation leads to mitochondrial calcium overload with subsequent mitochondrial dysfunction. Inhibition of the mitochondrial calcium uniporter (MCU) have been described to reduce asynchronized contraction in cellular and animal models. In this study, we assessed the effects that MCU inhibition by administration of Ru360, a MCU inhibitor, has on ventricular arrhythmia incidence in a model of catecholamine toxicity and characterize cellular and mitochondrial function to describe the subcellular mechanisms involved.MethodsThe study followed the national guidelines for laboratory animal use and care and was approved by the Animal Care and Use Committee. 12‐15‐week‐old C57bl/6 male mice received Ru360 or normal saline via IV, and a baseline ECG was recorded. Afterwards, Isoproterenol (400mg/kg) was administrated subcutaneously, and ECG recording was kept for another 20 minutes. Finally, hearts were excised, and cardiomyocytes and mitochondria isolated for further characterization. Data is presented as mean ± SEM. Fisher exact test was performed to evaluate arrhythmia incidence and one‐way ANOVA followed by Holm‐Sidak method for mitochondrial experiments and heart rate measurements.ResultsRu360 completely prevented the development of ventricular arrhythmias at a dose of 50nmol/kg. Mitochondrial Ca2+ transport inhibition preserved mitochondrial function and membrane integrity demonstrated by a preserved respiratory control and calcium retention capacity and a partially preserved mitochondrial membrane potential. MCU inhibition also prevented mitochondrial membrane potential loss upon the addition of a Ca2+ insult. The effects shown appear to be caused by a reduced oxidative stress, shown by a higher cytochrome c oxidase activity, that helps preserve cellular Ca2+ homeostasis as seen in confocal microscopy.ConclusionRu360 prevents arrhythmias possibly by reducing mitochondrial Ca2+ overload, preserving mitochondrial function, preventing mitochondrial ROS formation and oxidative damage, and conserving cellular Ca2+ homeostasis.

Effect of constant electric field stimulation of suspensions of selected microorganisms on geometric structure of cells

Wydawnictwo SIGMA-NOT wydaje czasopisma fachowe informujące swoich czytelników o najnowszych osiągnięciach naukowych i nowoczesnych rozwiązaniach technicznych w Polsce i na świecie, popularyzuje problemy techniczne oraz poszerza wiedzę i kulturę techniczną.

P269. Functional Connectivity Changes Between the sgACC and Meso-Cortico-Limbic Reward Network Following Deep Brain Stimulation Versus Magnetic Resonance-Guided Focused Ultrasound Capsulotomy in Depression

Functional network connectivity between the subgenual anterior cingulate cortex (sgACC) and the meso-cortico-limbic reward network (Biswal et al. 2010, Resting State Network number 17) selectively increases following DLPFC neuromodulation with transcranial magnetic stimulation (TMS) compared to other functional networks (Tik et al. 2017). Here we examined whether a similar connectivity change occurs between the sgACC and RSN-17 in patients with treatment-resistant depression (TRD) who underwent direct and constant stimulation to this region with deep brain stimulation (DBS) of the subcallosal cingulum versus magnetic resonance-guided focused ultrasound (MRgFUS) capsulotomy.

Transventricular Left Bundle Branch Pacing

Background. Implementation of conduction system permanent pacing methods in patients with cardiac bradyarrhythmias allows to maintain the physiological sequence of excitation and contraction of the ventricles and to avoid the development of heart failure due to electrical and mechanical dyssynchrony in patients with high rates of ventricular pacing.
 Case description. A 61-year-old female patient was examined and treated at the National Amosov Institute of Cardiovascular Surgery of the National Academy of Medical Sciences of Ukraine from January 25 to January 27, 2022 at the department of surgical treatment of complex cardiac arrhythmias with a diagnosis of proximal complete atrioventricular block. A two-chamber pacemaker (Vitatron Q50A2) with a ventricular lead to stimulate the His bundle region (Medtronic 3830, 69 cm) was implanted to the patient with a special delivery system (C315HIS). At an X-ray operating room, 12 ECG leads from the electrophysiological station LabSystem Pro (Bard, USA) were connected to the patient to analyze the criteria for capturing the conduction system on stimulation during ventricular lead placement, and a diagnostic quadripolar electrode was inserted into the right ventricle to record the potential of the His bundle as an X-ray reference point. During placement of the ventricular lead in the area of the His bundle due to high pacing thresholds the decision was made to implement an alternative method of conduction system pacing – left bundle branch pacing through the interventricular septum. After gradual passage of the electrode through the septum, capture of the conduction system of the heart was achieved, although no clear potential of the left bundle was registered. The interval from stimulus to peak R wave in lead V6 was 68 ms, and the interval from stimulus to peak R wave in lead V1 was 110 ms. The difference between intervals was 42 ms, which indicated the criteria of nonselective capture of the left bundle branch, with stimulation thresholds below 1 V at a pulse length of 0.5 ms. In the postoperative period, the patient was evaluated for global longitudinal deformity of the left ventricle on constant ventricular stimulation, which was carried out according to standard methods using speckle-tracking echocardiography; no signs of dyssynchrony were found. Also, the location of the endocardial electrode in the middle segments of the interventricular septum on the right ventricular side was visualized and confirmed by performing B-mode transthoracic echocardiography with subcostal access.
 Conclusions. Left bundle branch pacing, like His bundle pacing, maintains electrical and mechanical synchrony of the left ventricle at lower pacing thresholds, greater amplitude of the sensitivity signal and lower risks of lead dislocation.

Adaptation to tonic heat in healthy subjects and patients with sensory polyneuropathy.

Background Adaptation to a constant sensory stimulus involves many sites along the path of sensory volleys towards perception. The evaluation of such phenomenon may be of clinical interest. We studied adaptation to a constant temperature stimulus in healthy subjects to set normative data and in patients with sensory polyneuropathy (SPN), as proof of concept. Methods Twenty-six healthy subjects and 26 patients with SPN in the context of chemotherapy treatment with oxaliplatin for colon cancer were instructed to express through an electronic VAS system (eVAS); the level of sensation felt when a thermode set at either 39º, 41º, 43º, 45º or 47º was applied to their ventral forearm. Results The eVAS recordings showed typically an abrupt onset that slowed to approach maximum sensation and continued with a slow decrease indicating adaptation. The time to respond (TR), the velocity of the initial response (VR), the maximum sensation (MA), the time to reach MA (MAt), the onset of adaptation (AO) and the decrease in the sensation level with respect to MA at 30s after stimulus application (SL30), were dependent on the temperature level in all subjects. However, patients showed significantly delayed TR, slowed VR, decreased MA, delayed AO and reduced SL30, with respect to healthy subjects. Differences were more pronounced at low-temperature levels, with absent AO in 25 patients versus 2healthy subjects at temperatures of 39º and 41ºC. Conclusion The study of adaptation to a constant temperature stimulus can furnish valuable data for the assessment of patients with SPN. SIGNIFICANCE: We studied perceptual changes in the intensity of thermoalgesic sensation during 30s of constant temperature stimulation after an abrupt initial contact in healthy subjects and patients with sensory polyneuropathy. Patients showed delayed time to respond, decreased maximal sensation and reduced adaptation with respect to healthy subjects. Differences were more pronounced at low and intermediate temperatures (39ºC to 43ºC). The method is of easy implementation and shows clinically relevant abnormalities in patients with sensory polyneuropathy.

The crescendo pulse frequency of shear stress stimulates the endothelialization of bone marrow mesenchymal stem cells on the luminal surface of decellularized scaffold in the bioreactor

ABSTRACT A completely confluent endothelial cell (EC) monolayer is required to maintain proper vascular function in small diameter tissue-engineered vascular graft (TEVG). However, the most effective method for EC attachment to the luminal surface and formation of an entire endothelium layer that works in vitro remains a complicated challenge that requires urgent resolution. Although pulsatile flow has been shown to be better suited for the generation of functional endothelium, the optimal frequency setting is unknown. Several pulsatile flow frequencies were used to implant rat bone mesenchymal stem cells (MSC) into the lumen of decellularized porcine carotid arteries. The endothelium's integrity and cell activity were investigated in order to determine the best pulse frequency settings. The results showed that MSC were maximally preserved and exhibited maximal morphological changes with improved endothelialization performance in response to increased pulse stimulation frequency. Increased pulse frequency stimulation stimulates the expression of mechanoreceptor markers, cytoskeleton reorganization in the direction of blood flow, denser skeletal proteins fibronectin, and stronger intercellular connections when compared to constant pulse frequency stimulation. MSC eventually develops an intact endothelial layer with anti-thrombotic properties on the inner wall of the decellularized tubular lumen. Conclusion: The decellularized vessels retain the three-dimensional structure of the vasculature, have a surface topography suitable for MSC growth, and have good mechanical properties. By increasing the frequency of pulsed stimulation, MSC endothelialize the lumen of the decellularized vasculature. It is expected to have anti-thrombotic and anti-neointimal hyperplasia properties after implantation, ultimately improving the patency of TEVG.

Association Between Problematic Social Media Use and Attention-Deficit/Hyperactivity Disorder in a Sample of Lebanese Adults.

Objective: Attention-deficit/hyperactivity disorder (ADHD) has been recognized as a clinically diverse condition with elevated rates of comorbidities with other psychiatric conditions. The consequences of social media are gaining attention worldwide due to its rapidly increased use. The objective of this study was to identify an association between problematic social media use and ADHD in a Lebanese sample and determine whether depression or anxiety could be considered as mediators of this association.Methods: This cross-sectional study was conducted between January and May 2019. Proportionate random-sampling techniques were applied on all Lebanese governorates, which resulted in the recruitment of 466 community-dwelling participants. Adult ADHD was identified using the Adult ADHD Self-Report Scale.Results: Higher problematic social media use (adjusted odds ratio [aOR] = 1.065) was significantly associated with higher odds of having ADHD. When anxiety was added as an independent variable, the results showed that higher anxiety (aOR = 1.043) was significantly associated with higher odds of ADHD. Anxiety mediated the association between problematic social media use and ADHD by 26.75%.Conclusions: A clear correlation was demonstrated in this study linking problematic social media use to anxiety and ADHD symptoms. This correlation was explained by the finding that constant stimulation provided by the social network sites significantly decreased attention. Future studies should evaluate the possible mechanisms and methods to increase awareness of problematic social media use, especially among the younger generation.

Why Should Constant Stimulation of Saccular Afferents Modify the Posture and Gait of Patients with Bilateral Vestibular Dysfunction? The Saccular Substitution Hypothesis.

An ongoing EU Horizon 2020 Project called BionicVEST is investigating the effect of constant electrical stimulation (ES) of the inferior vestibular nerve in patients with bilateral vestibular dysfunction (BVD). The evidence is that constant ES results in improved postural stability and gait performance, and so the question of central importance concerns how constant ES of mainly saccular afferents in these BVD patients could cause this improved performance. We suggest that the constant ES substitutes for the absent saccular neural input to the vestibular nuclei and the cerebellum in these BVD patients and indirectly via these structures to other structures, which have been of great recent interest in motor control. One target area, the anterior midline cerebellum (the uvula), has recently been targeted as a location for deep-brain stimulation in human patients to improve postural stability and gait. There are projections from midline cerebellum to basal ganglia, including the striatum, which are structures involved in the initiation of gait. It may be that the effect of this activation of peripheral saccular afferent neurons is analogous to the effect of deep-brain stimulation (DBS) by electrodes in basal ganglia acting to help alleviate the symptoms of patients with Parkinson’s disease.

Young Children’s Experiences with Yoga after School

ABSTRACT Currently, little is known about the lived experiences of children who participate in yoga, particularly using their own words. This study provides insights into how young children aged 6 to 10 years old were able to understand their bodies within a yoga space. The purpose of this study was to investigate young children’s lived experiences of yoga through qualitative interviews. Parents of children engaged in yoga were also interviewed to gain a sense of their point of view about the experiences of yoga for their children. Results indicated yoga had assisted children to find, and express joy, and fun by moving their bodies into different shapes. The physical and psychological difficulty of some of the yoga shapes assisted children to develop a persistent mind-set which enabled them to transfer knowledge to different contexts, such as difficulties at school, and finding ways to relax, and be with themselves. Yoga as an activity after-school develops strategies such as resilience, and assists in other contexts such as school, and family. The parents’ described how they were looking for techniques to help calm their children, and how challenging this was with the constant stimulation of everyday activities. The findings suggest that yoga may have a place in the school curriculum for the purpose of teaching students’ simple coping skills when experiencing feelings of stress, and anxiety, and assist with controlling their behavior.

Altered mechanotransduction in adolescent idiopathic scoliosis osteoblasts: an exploratory in vitro study

Adolescent idiopathic scoliosis (AIS) is the most prevalent pediatric spinal deformity. We previously demonstrated elongated cilia and an altered molecular mechanosensory response in AIS osteoblasts. The purpose of this exploratory study was to characterize the mechanosensory defect occurring in AIS osteoblasts. We found that cilia length dynamics in response to flow significantly differ in AIS osteoblasts compared to control cells. In addition, strain-induced rearrangement of actin filaments was compromised resulting in a failure of AIS osteoblasts to position or elongate in function of the bidirectional-applied flow. Contrary to control osteoblasts, fluid flow had an inhibitory effect on AIS cell migration. Moreover, flow induced an increase in secreted VEGF-A and PGE2 in control but not AIS cells. Collectively our data demonstrated that in addition to the observed primary cilium defects, there are cytoskeletal abnormalities correlated to impaired mechanotransduction in AIS. Thus, we propose that the AIS etiology could be a result of generalized defects in cellular mechanotransduction given that an adolescent growing spine is under constant stimulation for growth and bone remodeling in response to applied mechanical forces. Recognition of an altered mechanotransduction as part of the AIS pathomechanism must be considered in the conception and development of more effective bracing treatments.

Evaluation of the efficacy of a new variable frequency stimulation sacral neuromodulation in the treatment of detrusor hyperactivity with impaired contractility

A total of 16 detrusor hyperactivity with impaired contractility (DHIC) patients who received 12 weeks remote variable frequency stimulation (VFS) were enrolled at the First Affiliated Hospital of Zhengzhou University from September 2020 to February 2021. The voiding diary, symptom score scales and incidence of complications were completed and recorded at baseline, constant frequency stimulation (CFS) and VFS phases. Compared with the CFS phase, voiding times, urge incontinence times and daily catheterization volume were reduced; average voiding amount and functional bladder capacity increased; and the quality of life score and mental health questionnaire assessment were improved in the VFS phase(all P<0.05). In the end, among all 16 patients, there were 14 whose symptoms had improved, and there were no new complications such as pain or infection at the implantation site, electrode displacement, and electric shock sensation in the stimulation area. VFS-SNM can not only improve the DHIC patients' lower urinary tract symptoms during storage and urination period, but also improve the patients' quality of life and satisfaction of the therapy.

The role of posterior pallial amygdala in mediating motor behaviors in pigeons

The posterior pallial amygdala (PoA) is located on the basolateral caudal telencephalon, including the basal division of PoA (PoAb) and the compact division of PoA (PoAc). PoA plays a vital role in emotion regulation and is considered a part of the amygdala in birds. However, the regulatory functions responsible for motor behaviors and emotions between PoAb and PoAc are poorly understood. Therefore, we studied the structure and function of PoA by tract-tracing methods, constant current electrical stimulation, and different dopamine receptor drug injections in pigeons (Columba livia domestica). PoAb connects reciprocally with two nuclear groups in the cerebrum: 1) a continuum comprising the temporo–parieto–occipitalis, corticoidea dorsolateralis, hippocampus, and parahippocampalis areas and 2) rostral areas of the hemisphere, including the nucleus septalis lateralis and nucleus taeniae amygdalae. Extratelencephalic projections of PoAb terminate in the lateral hypothalamic nucleus and are scattered in many limbic midbrain regions. PoAb and PoAc mainly mediated the turning movement. In the ‘open-field’ test, D1 agonist and D2 antagonist could significantly reduce the latency period for entering into the central area and increase the residence time in the central area, whereas D1 antagonist and D2 agonist had the opposite effect. PoAb and PoAc are important brain areas that mediate turning behavior.

Suckling strategies in terrestrial ungulates (Artiodactyla, Perissodactyla) and the factors influencing them: the offspring perspective

AbstractIn order to survive, ungulate young obtain their mother’s colostrum and milk through a variety of suckling strategies. Here, these strategies and the factors that influence them are reviewed and interpreted primarily from the perspective of the young. Suckling strategies are determined by a variety of factors, some of which play a role even before birth. Neonatal suckling behaviour depends first on the type of placenta and the developmental stage of the young at birth. Ungulates have an epitheliochorial placenta in which transplacental transport of immunoglobulins is impeded. Therefore, they are born in a hypo−/agammaglobulinemic state hence, timely intake of sufficient colostrum is a life-or-death situation and an unsuccessful suckling strategy is likely to result in death. Precociality enables the newborn ungulate to actively participate in the suckling process immediately after birth, which is critically important. After the prenatally defined physiological needs are satisfied, young suckling strategy is influenced by other factors. Continuous milk production requires constant use and stimulation of the mammary gland. Brain lateralization has also been found to play a role in suckling behaviour. Finally, competition between siblings or peers in the social group also influences young suckling strategies. Sibling competition particularly affects polytocous ungulates and leads to suckling order, for example. Similarly, interactions within the social group create the conditions for the emergence of specific strategies, including allosuckling, strategy of suckling a non-filial mother. The young suckling strategies in ungulates basically represent an evolutionary intertwining of offspring selfishness and selection that maximises inclusive fitness.

Strengths in Vietnam's economic growth

Economic growth is an important indicator of the quality of the economy. A common measure is the increase in gross domestic product (GDP) in a year or the increase in GDP per capita in a year. Over the past time, Vietnam's economy has made remarkable growth steps and achieved many great achievements. The constantly improving position of Vietnam in the international arena; the good control of the spread of the Covid-19 pandemic in the country; the quality of human resources have been gradually improved; The state’s constant encouragement and stimulation to develop the economy; The integration and opening of the economy are the strengths of economic growth that the article mentions. In the future, although the situation of Covid-19 is still complicated with new strains that are difficult to predict, Vietnam's economy can still achieve positive growth. The reason is that Vietnam's current policies are geared towards disease prevention combined with economic development. In this article, the author uses the method of analyzing secondary data from many reputable and reliable sources such as: ADB, UOB, General Statistics Office of Vietnam, ... to provide readers with more information, new materials, and a more thorough view on the overview picture of current status of Vietnam's economic growth in the period from 2016 to present.

Determination of the tonographic effect in the human eye using a pneumatic pressure modulator

AbstractPurposeThe tonographic effect has been observed in several studies in occulopression, repeated tonometry or ophthalmodynamometry. It describes an intraocular pressure (IOP) decrease caused by an artifical IOP increase. In healthy eyes, an IOP drop of 2–3 mmHg/min was reported. However, there are studies that show a reduced decrease of the IOP drop for instance in glaucoma patients. In this work, we present a proof of principle to determine the tonographic effect in healthy eyes by utilizing a novel pneumatic pressure modulator.MethodsThe study was conducted on 8 healthy subjects (4 m, 4 f, 1 eye each, mean age 27.4 ± 7.1 yr). All subjects passed an ophthalmic examination procedure, including visual acuity determination, tonometry, objective refraction, slit lamp examination. Exclusion criteria were myopia &lt; ‐8 dpt, anamnestic surgeries, corneal scars, eye diseases, ocular hypertension, and ongoing ocular local therapy. No anaesthetics were used. A pressure modulator (IOPstim, Imedos Systems GmbH, Jena, Germany) was used to increase the IOP to initially pathologic IOP values of about 35 mmHg (36.6 ± 2.5 mmHg). The applied pressure was kept constant for 2 minutes. The IOP was measured 4 times (at 0s, 40s, 80s, and 120s) using a rebound tonometer (Icare PRO, Icare Finland Oy, Helsinki, Finland). Linear regression was performed to calculate the average IOP decrease within the 2‐minutes interval.ResultsFor all 8 subjects, a typical decrease of the IOP was observed during a 2 min constant pressure stimulation. The mean decrease of the pressure profiles was 2.77 mmHg/min (R2 = 0.94).ConclusionsWe successfully applied a pneumatic pressure modulator to determine the tonographic effect in the human eye. For 2 min we measured the mean decrease of the IOP drop with similar values known by the literature. Application of the pneumatic pressure modulator allows the investigation of pathological reduced IOP drops that differ from normal values as shown in this study.

Follicular dendritic cells.

Follicular dendritic cells (FDCs) are unique accessory immune cells that contribute to the regulation of humoral immunity. They are multitasker cells essential for the organization and maintenance of the lymphoid architecture, induction of germinal center reaction, production of B memory cells, and protection from autoimmune disorders. They perform their activities through both antigen-driven and chemical signaling to B cells. FDCs play a crucial role in the physiological regulation of the immune response. Dis-regulation of this immune response results when FDCs retain antigens for years. This provides a constant antigenic stimulation for B cells resulting in the development of immune disorders. Antigen trapped on FDCs is resistant to therapeutic intervention causing chronicity and recurrences. Beyond their physiological immunoregulatory functions, FDCs are involved in the pathogenesis of several immune-related disorders including HIV/AIDS, prion diseases, chronic inflammatory, and autoimmune disorders. FDCs have also been recently implicated in rare neoplasms of lymphoid and hematopoietic tissues. Understanding FDC biology is essential for better control of humoral immunity and opens the gate for therapeutic management of FDC-mediated immune disorders. Thus, the biology of FDCs has become a hot research area in the last couple of decades. In this review, we aim to provide a comprehensive overview of FDCs and their role in physiological and pathological conditions.

Feedback Control of Upright Seating with Functional Neuromuscular Stimulation during a Functional Task after Spinal Cord Injury: A Case Study.

Seated stability is a major concern of individuals with trunk paralysis. Trunk paralysis is commonly caused by spinal cord injuries (SCI) at or above the thoracic spine. Current methods to improve stability restrict the movement of the user by constraining their trunk to an upright position. Feedback control of functional neuromuscular stimulation (FNS) can help maintain seated stability while still allowing the user to perform movements to accomplish functional tasks. In this study, an individual with a SCI (C7, AIS B) and an implanted stimulator capable of recruiting trunk and hip musculature unilaterally moved a weighted jar on a countertop to and from three prescribed stations directly in front, laterally, and across midline. For comparison, the tasks were performed with constant baseline stimulation and with feedback modulated stimulation based on the tilt of the trunk obtained from an external accelerometer fed into two PID controllers; one for forward trunk pitch and the other for lateral roll. The trunk pitch and roll angles were obtained through motion capture cameras and various measures of postural sway (95% fitted ellipse area, root mean squared (RMS), path length) and the repeatability (coefficient of variation (CoV), variance ratio (VR)) were calculated. Feedback control significantly increased RMS of trunk movement along the major axis of the fitted ellipse, but decreased RMS values during bending along the minor axis of motion. As a result, the fitted ellipse area decreased when deploying the jar to one of the stations and increased with the other two. The CoV indicated reduced variation in the presence of feedback controlled stimulation for all stations, and VR showed higher repeatability in trunk pitch. Plots of the trunk pitch and roll revealed a faster return to upright motion due to feedback stimulation.Clinical relevance- Feedback control in combination with FNS is a viable method to improve seated stability while still allowing dynamic movements in individuals with a SCI, thus addressing a major concern of the population.

Sputtered Ruthenium Oxide Neural Stimulation Electrodes.

We have investigated the charge-injection properties of sputtered ruthenium oxide (RuOx) coatings deposited on planar microelectrode arrays. Substantial charge was found to be available for injection within -0.6/0.6 V vs Ag|AgCl potential limits for the sputtered RuOx film. The charge-injection capacity increased further upon extending the potential limits to -0.7/0.7 V vs Ag|AgCl. No oxygen reduction, an unwanted side reaction, was observed during the pulsing of sputtered RuOx microelectrodes in phosphate buffered saline solution. Additionally, the RuOx coatings were found to be electrochemically stable for up to 1-billion-cycles of constant current stimulation pulsing at 8 nC/phase in model-ISF at 37° C.

Granulocytic Myeloid-Derived Suppressor Cells in Cystic Fibrosis.

Cystic Fibrosis (CF) is a genetic disease that causes chronic and severe lung inflammation and infection associated with high rates of mortality. In CF, disrupted ion exchange in the epithelium results in excessive mucus production and reduced mucociliary clearance, leading to immune system exacerbation and chronic infections with pathogens such as P. aeruginosa and S. aureus. Constant immune stimulation leads to altered immune responses including T cell impairment and neutrophil dysfunction. Specifically, CF is considered a Th17-mediated disease, and it has been proposed that both P. aeruginosa and a subset of neutrophils known as granulocytic myeloid suppressor cells (gMDSCs) play a role in T cell suppression. The exact mechanisms behind these interactions are yet to be determined, but recent works demonstrate a role for arginase-1. It is also believed that P. aeruginosa drives gMDSC function as a means of immune evasion, leading to chronic infection. Herein, we review the current literature regarding immune suppression in CF by gMDSCs with an emphasis on T cell impairment and the role of P. aeruginosa in this dynamic interaction.