Regenerative peripheral nerve interfaces for real-time,proportional control of a Neuroprosthetic hand

Introduction

Regenerative peripheral nerve interfaces (RPNIs) are biological constructs which amplify neural signals and have shown long-term stability in rat models. Real-time control of a neuroprosthesis in rat models has not yet been demonstrated. The purpose of this study was to: a) design and validate a system for translating electromyography (EMG) signals from an RPNI in a rat model into real-time control of a neuroprosthetic hand, and; b) use the system to demonstrate RPNI proportional neuroprosthesis control.

Methods

Animals were randomly assigned to three experimental groups: (1) Control; (2) Denervated, and; (3) RPNI. In the RPNI group, the extensor digitorum longus (EDL) muscle was dissected free, denervated, transferred to the lateral thigh and neurotized with the residual end of the transected common peroneal nerve. Rats received tactile stimuli to the hind-limb via monofilaments, and electrodes were used to record EMG. Signals were filtered, rectified and integrated using a moving sample window. Processed EMG signals (iEMG) from RPNIs were validated against Control and Denervated group outputs.

Results

Voluntary reflexive rat movements produced signaling that activated the prosthesis in both the Control and RPNI groups, but produced no activation in the Denervated group. Signal-to-Noise ratio between hind-limb movement and resting iEMG was 3.55 for Controls and 3.81 for RPNIs. Both Control and RPNI groups exhibited a logarithmic iEMG increase with increased monofilament pressure, allowing graded prosthetic hand speed control (R²?=?0.758 and R²?=?0.802, respectively).

Conclusion

EMG signals were successfully acquired from RPNIs and translated into real-time neuroprosthetic control. Signal contamination from muscles adjacent to the RPNI was minimal. RPNI constructs provided reliable proportional prosthetic hand control.

     

Home-based cycling program tailored to older people with lumbar spinal stenosis: Barriers and facilitators

Background

Lumbar-flexion-based endurance training, namely cycling, could be effective in reducing pain and improving function and health-related quality of life in older people with chronic low back pain.

Nonreconstruction Options for Treating Medial Ulnar Collateral Ligament Injuries of the Elbow in Overhead Athletes

Purpose of Review

This review aims to describe the nonreconstructive options for treating ulnar collateral ligament (UCL) injuries ranging from nonoperative measures, including physical therapy and biologic injections, to ligament repair with and without augmentation.

Recent Findings

Nonoperative options for UCL injuries include guided physical therapy and biologic augmentation with platelet-rich plasma (PRP). In some patients, repair of the UCL has shown promising return to sport rates by using modern suture and suture anchor techniques. Proximal avulsion injuries have shown the best results after repair. Currently, there is growing interest in augmentation of UCL repair with an internal brace.

Summary

The treatment of UCL injuries involves complex decision making. UCL reconstruction remains the gold standard for attritional injuries and complete tears, which occur commonly in professional athletes. However, nonreconstructive options have shown promising results for simple avulsion or partial thickness UCL injuries. Future research comparing reconstructive versus nonreconstructive options is necessary.

     

Pilot Trial of a Comprehensive Summer Psychosocial Treatment for High-Functioning Young Children with ASD

This study examined the feasibility and preliminary outcomes of a comprehensive summer psychosocial treatment (summerMAX^yc) for high-functioning young children, ages 4–6 years, with ASD (HFASD). The 5-week treatment, conducted 5 days per week, 6 h per day, included skills instruction and therapeutic activities targeting social/social-communication skills, facial-emotion recognition, and interest expansion. A behavioral system was implemented to increase skills acquisition and maintenance and reduce ASD symptoms and problem behaviors. Feasibility was supported in high levels of treatment fidelity and child, parent, and staff clinician satisfaction. Significant post-treatment improvements were found for 9 of 10 outcome measures including parent and staff clinician ratings of targeted social/social-communication skills, ASD symptoms, and broader adaptive social and communication skills, and staff clinician ratings of daily living skills. Results suggested that summerMAX^yc was feasible and may yield positive outcomes for 4–6 year olds with HFASD.     

The interplay between metabolic alterations,diastolic strain rate and exercise capacity in mild heart failure with preserved ejection fraction: a cardiovascular magnetic resonance study

Background

Heart failure (HF) is characterized by altered myocardial substrate metabolism which can lead to myocardial triglyceride accumulation (steatosis) and lipotoxicity. However its role in mild HF with preserved ejection fraction (HFpEF) is uncertain. We measured myocardial triglyceride content (MTG) in HFpEF and assessed its relationships with diastolic function and exercise capacity.

Methods

Twenty seven HFpEF (clinical features of HF, left ventricular EF >50%, evidence of mild diastolic dysfunction and evidence of exercise limitation as assessed by cardiopulmonary exercise test) and 14 controls underwent ¹H-cardiovascular magnetic resonance spectroscopy (¹H-CMRS) to measure MTG (lipid/water, %), ³¹P-CMRS to measure myocardial energetics (phosphocreatine-to-adenosine triphosphate - PCr/ATP) and feature-tracking cardiovascular magnetic resonance (CMR) imaging for diastolic strain rate.

Results

When compared to controls, HFpEF had 2.3 fold higher in MTG (1.45?±?0.25% vs. 0.64?±?0.16%, p?=?0.009) and reduced PCr/ATP (1.60?±?0.09 vs. 2.00?±?0.10, p?=?0.005). HFpEF had significantly reduced diastolic strain rate and maximal oxygen consumption (VO₂ max), which both correlated significantly with elevated MTG and reduced PCr/ATP. On multivariate analyses, MTG was independently associated with diastolic strain rate while diastolic strain rate was independently associated with VO₂ max.

Conclusions

Myocardial steatosis is pronounced in mild HFpEF, and is independently associated with impaired diastolic strain rate which is itself related to exercise capacity. Steatosis may adversely affect exercise capacity by indirect effect occurring via impairment in diastolic function. As such, myocardial triglyceride may become a potential therapeutic target to treat the increasing number of patients with HFpEF.

     

Interstitial Cystitis: An Update on the Disease Process and Treatment

Abstract

Interstitial cystitis (IC) is a chronic pain disorder of the bladder that is often underdiagnosed and mistreated. The difficulties in diagnosis stem from numerous theories regarding pathophysiology and etiology, including the breakdown of the glycosaminoglycan (GAG) layer, altered permeability of the urothelium, uroinflammation, and neural up-regulation. Dysfunction of the bladder increases the struggle for proper treatment and continues to prove difficult for health care providers to correctly diagnose and manage IC. If diagnosed and/or managed inappropriately, IC may contribute to increased symptom burden and decreased quality of life with respect to activities of daily living. When evaluating a patient’s clinical presentation in combination with predefined risk factors, a health care provider can better establish a true diagnosis of IC, which, in turn, leads to better management of IC-associated symptoms. This review will help health care providers better understand the disease process by discussing pathophysiology, pain pathways, and common symptoms of IC, with the goal of better aiding them in the proper diagnosis and treatment of patients with IC.     

The influence of substituent field and resonance effects on the ease of N-heterocyclic carbene formation from imidazolium rings

Using a set of twelve selected substituents, the influence of substituent properties on the ease of deprotonation of imidazolium cations and mesoionic imidazolium-4-olates measured by the CREF index has been investigated. Significant correlations between CREF values and the Swain and Lupton field (F) and resonance (R) substituent constants have been found. In all cases the field effect has the greatest influence but resonance effects are also significant.

The influence of substituents on the relative acidity of C–H bonds.