Efficacy of a hybrid assistive limb in post-stroke hemiplegic patients: a preliminary report

<p>Abstract</p> <p>Background</p> <p>Robotic devices are expected to be widely used in various applications including support for the independent mobility of the elderly with muscle weakness and people with impaired motor function as well as support for nursing care that involves heavy laborious work. We evaluated the effects of a hybrid assistive limb robot suit on the gait of stroke patients undergoing rehabilitation.</p> <p>Methods</p> <p>The study group comprised 16 stroke patients with severe hemiplegia. All patients underwent gait training. Four patients required assistance, and 12 needed supervision while walking. The stride length, walking speed and physiological cost index on wearing the hybrid assistive limb suit and a knee-ankle-foot orthosis were compared.</p> <p>Results</p> <p>The hybrid assistive limb suit increased the stride length and walking speed in 4 of 16 patients. The patients whose walking speed decreased on wearing the hybrid assistive limb suit either had not received sufficient gait training or had an established gait pattern with a knee-ankle-foot orthosis using a quad cane. The physiological cost index increased after wearing the hybrid assistive limb suit in 12 patients, but removal of the suit led to a decrease in the physiological cost index values to equivalent levels prior to the use of the suit.</p> <p>Conclusions</p> <p>Although the hybrid assistive limb suit is not useful for all hemiplegic patients, it may increase the walking speed and affect the walking ability. Further investigation would clarify its indication for the possibility of gait training.</p

Monkeys mutant for PKD1 recapitulate human autosomal dominant polycystic kidney disease.

Autosomal dominant polycystic kidney disease (ADPKD) caused by PKD1 mutations is one of the most common hereditary disorders. However, the key pathological processes underlying cyst development and exacerbation in pre-symptomatic stages remain unknown, because rodent models do not recapitulate critical disease phenotypes, including disease onset in heterozygotes. Here, using CRISPR/Cas9, we generate ADPKD models with PKD1 mutations in cynomolgus monkeys. As in humans and mice, near-complete PKD1 depletion induces severe cyst formation mainly in collecting ducts. Importantly, unlike in mice, PKD1 heterozygote monkeys exhibit cyst formation perinatally in distal tubules, possibly reflecting the initial pathology in humans. Many monkeys in these models survive after cyst formation, and cysts progress with age. Furthermore, we succeed in generating selective heterozygous mutations using allele-specific targeting. We propose that our models elucidate the onset and progression of ADPKD, which will serve as a critical basis for establishing new therapeutic strategies, including drug treatments

Role of rac1 in fibronectin-induced adhesion and motility of human corneal epithelial cells. Invest Ophthalmol Vis Sci.

PURPOSE. The fibronectin-integrin system plays an important role in adhesion and migration of corneal epithelial cells and thereby contributes to epithelial wound healing. The role of Rac1, a member of the Rho family of GTPases, in the intracellular signaling responsible for regulation of the adhesion and motility of corneal epithelial cells by fibronectin was examined. METHODS. Simian virus 40 -transformed human corneal epithelial (HCE) cells were plated on fibronectin or on bovine serum albumin as a control. Cell motility was monitored by time-lapse video microscopy. The actin cytoskeleton and focal adhesions were detected by staining of cells with rhodamine-phalloidin and antibodies to phosphotyrosine, respectively. The activation of Rac1 and phosphorylation of its effector PAK were evaluated with a pull-down assay and immunoblot analysis, respectively. The effects of mutant forms of Rac1 were determined by cell transfection. RESULTS. HCE cells plated on fibronectin manifested greater levels of cell adhesion and motility than did those plated on bovine serum albumin. Fibronectin also induced the accumulation of F-actin and the formation of focal adhesions at the cell periphery as well as the activation of Rac1 and the phosphorylation of PAK. Expression of the dominant negative mutant Asn17Rac1 inhibited the effects of fibronectin on cell adhesion and motility, the actin cytoskeleton, and focal adhesions. Expression of the constitutive active mutant Val12Rac1 mimicked the effects of fibronectin on F-actin and focal adhesions. CONCLUSIONS. Rac1 is necessary for the promotion of HCE cell adhesion and motility by fibronectin. It therefore probably plays an important role in corneal wound healing. (Invest Ophthalmol Vis Sci