Electromechanical and robotic devices for gait and balance rehabilitation of children with neurological disability: a systematic review

In the last two decades, a growing interest has been focused on gait and balance robot-assisted rehabilitation in children with neurological disabilities. Robotic devices allow the implementation of intensive, task-specific training fostering functional recovery and neuroplasticity phenomena. However, limited attention has been paid to the protocols used in this research framework. This systematic review aims to provide an overview of the existing literature on robotic systems for the rehabilitation of gait and balance in children with neurological disabilities and their rehabilitation applications. The literature search was carried out independently and synchronously by three authors on the following databases: MEDLINE, Cochrane Library, PeDro, Institute of Electrical and Electronics Engineers, ScienceDirect, and Google Scholar. The data collected included three subsections referring to clinical, technical, and regulatory aspects. Thirty-one articles out of 81 found on the primary literature search were included in the systematic review. Most studies involved children with cerebral palsy. Only one-third of the studies were randomized controlled trials. Overall, 17 devices (nine end-effector systems and eight exoskeletons) were investigated, among which only 4 (24%) were bore the CE mark. Studies differ on rehabilitation protocols duration, intensity, and outcome measures. Future research should improve both rehabilitation protocols\u2019 and devices\u2019 descriptions

S-Glutathionylation at Cys328 and Cys542 Impairs STAT3 Phosphorylation.

STAT3 is a latent transcription factor that promotes cell survival and proliferation and is often constitutively active in cancers. Although many reports provide evidence that STAT3 is a direct target of oxidative stress, its redox regulation is poorly understood. Under oxidative conditions STAT3 activity can be modulated by S-glutathionylation, a reversible redox modification of cysteine residues. This suggests the possible cross-talk between phosphorylation and glutathionylation and points out that STAT3 is susceptible to redox regulation. Recently, we reported that decreasing the GSH content in different cell lines induces inhibition of STAT3 activity through the reversible oxidation of thiol groups. In the present work, we demonstrate that GSH/diamide treatment induces S-glutathionylation of STAT3 in the recombinant purified form. This effect was completely reversed by treatment with the reducing agent dithiothreitol, indicating that S-glutathionylation of STAT3 was related to formation of protein-mixed disulfides. Moreover, addition of the bulky negatively charged GSH moiety impairs JAK2-mediated STAT3 phosphorylation, very likely interfering with tyrosine accessibility and thus affecting protein structure and function. Mass mapping analysis identifies two glutathionylated cysteine residues, Cys328 and Cys542, within the DNA-binding domain and the linker domain, respectively. Site direct mutagenesis and in vitro kinase assay confirm the importance of both cysteine residues in the complex redox regulatory mechanism of STAT3. Cells expressing mutant were resistant in this regard. The data presented herein confirmed the occurrence of a redox-dependent regulation of STAT3, identified the more redox-sensitive cysteines within STAT3 structure, and may have important implications for development of new drugs

The Dimerization Domain in Outer Segment Guanylate Cyclase Is a Ca²⁺-Sensitive Control Switch Module

Membrane-bound guanylate cyclases harbor a region called the dimerization or linker domain, which aids the enzymes in adopting an optimal monomer–monomer arrangement for catalysis. One subgroup of these guanylate cyclases is expressed in rod and cone cells of vertebrate retina, and mutations in the dimerization domain of rod outer segment guanylate cyclase 1 (ROS-GC1, encoded by the <i>GUCY2D</i> gene) correlate with retinal cone-rod dystrophies. We investigate how a Q847L/K848Q double mutation, which was found in patients suffering from cone-rod dystrophy, and the Q847L and K848Q single-point mutations affect the regulatory mechanism of ROS-GC1. Both the wild type and mutants of heterologously expressed ROS-GC1 were present in membranes. However, the mutations affected the catalytic properties of ROS-GC1 in different manners. All mutants had higher basal guanylate cyclase activities but lower levels of activation by Ca²⁺-sensing guanylate cyclase-activating proteins (GCAPs). Further, incubation with wild-type GCAP1 and GCAP2 revealed for all ROS-GC1 mutants a shift in Ca²⁺ sensitivity, but activation of the K848Q mutant by GCAPs was severely impaired. Apparent affinities for GCAP1 and GCAP2 were different for the double mutant and the wild type. Circular dichroism spectra of the dimerization domain showed that the wild type and mutants adopt a prevalently α-helical structure, but mutants exhibited lower thermal stability. Our results indicate that the dimerization domain serves as a Ca²⁺-sensitive control module. Although it is per se not a Ca²⁺-sensing unit, it seems to integrate and process information regarding Ca²⁺ sensing by sensor proteins and regulator effector affinity

Clinical improvement of ocular surface parameters in dry eye patients following treatment with urea/crosslinked-hyaluronate eyedrops correlates with the secretion of MUC-4

Objectives: To assess the ocular surface status after treatment with urea/crosslinked hyaluronate (U-HACL) tear substitute in dry eye (DE) patients. Methods: Seventeen DE patients were included in the study. They instilled U-HACL drops three times/day for 2 months. Symptoms (by OSDI and VAS), osmolarity, tear film (through Schirmer and tear film breakup time), corneal and conjunctival damage (with NEI and van Bijsterveld scores), impression cytology (number of PAS positive cells and MUC-4 immunostaining), and tear sampling were analyzed pre- and posttreatment. Results: After the treatment, there was a significant improvement of VAS (7.16 ± 2.59 vs. 3.94 ± 2.23), OSDI (56.96 ± 25.97 vs. 29.94 ± 20.15), Schirmer (8.22 ± 6.86 vs. 10.66 ± 6.92), TFBUT (3.16 ± 2.28 vs. 5.55 ± 2.47), NEI (7.16 ± 2.50 vs. 2.88 ± 2.80), and van Bijsterveld (10.27 ± 4.25 vs. 6.5 ± 3.79) score, p &lt; 0.01. There was a significant increase of PAS positive cells and MUC-4 (respectively, 44.21 ± 14.8 vs. 67.0 ± 10.1 and 49.79 ± 20.0 vs. 75.9 ± 20.7), p &lt; 0.01. Conclusion: The rise of MUC-4 expression probably contributed to the increase in ocular wettability and amelioration of clinical parameters following the administration of U-HACL eye drops

Differential Nanosecond Protein Dynamics in Homologous Calcium Sensors

Shaping the temporal response of photoreceptors is facilitated by a well-balanced second messenger cascade, in which two neuronal Ca²⁺-sensor proteins operate in a sequential relay mechanism. Although they share structurally similar sensing units, they differentially activate the same target protein. Here, as a prototypical case in Ca²⁺-mediated signal processing, we investigate differential cellular responsiveness in protein conformational dynamics on a nanosecond time scale. For this, we have site-specifically labeled cysteine residues in guanylate cyclase-activating protein GCAP1 by the fluorescent dye Alexa647 and probed its local environment via time-resolved fluorescence spectroscopy. Fluorescence lifetime and rotational anisotropy measurements reveal a distinct structural movement of the polypeptide chain around position 106 upon release of Ca²⁺. This is supported by analyzing the diffusional dye motion in a wobbling-in-a-cone model and by molecular dynamics simulations. We conclude that GCAP1 and its cellular cognate GCAP2 operate by distinctly different switching mechanisms despite their high structural homology