Combined functional electrical stimulation (FES) and robotic system for wrist rehabiliation after stroke.

Functional electrical stimulation (FES) and rehabilitation robots are techniques used to assist in post-stroke rehabilitation. However, FES and rehabilitation robots are still separate systems currently; and their combined training effects on persons after experiencing a stroke have not been well studied yet. In this work, a new combined FES-robot system driven by user's voluntary intention was developed for wrist joint training after stroke. The performance of the FES-robot assisted wrist tracking was evaluated on five subjects with chronic stroke. With simultaneous assistance from both the FES and robot parts of the system, the motion accuracy was improved and excessive activation in elbow flexor was reduced during wrist tracking.

Mediation of oxidative stress in hypothalamic ghrelin-associated appetite control in rats treated with phenylpropanolamine.

Phenylpropanolamine (PPA)-induced appetite control is associated with oxidative stress in the hypothalamus. This study explored whether hypothalamic antioxidants participated in hypothalamic ghrelin system-associated appetite control in PPA-treated rats. Rats were given PPA daily for 4 days, and changes in food intake and the expression of neuropeptide Y (NPY), the cocaine- and amphetamine-regulated transcript (CART), superoxide dismutase, catalase, ghrelin, acyl ghrelin (AG), ghrelin O-acyltransferase (GOAT) and the ghrelin receptor (GHSR1a) were examined and compared. Results showed that both food intake and the expression of NPY and ghrelin/AG/GOAT/GHSR1a decreased in response to PPA treatment with maximum decrease on Day 2 of the treatment. In contrast, the expression of antioxidants and CART increased, with the maximum increase on Day 2, with the expression opposite to that of NPY and ghrelin. A cerebral infusion of either a GHSR1a antagonist or reactive oxygen species scavenger modulated feeding behavior and NPY, CART, antioxidants and ghrelin system expression, showing the involvement of ghrelin signaling and oxidative stress in regulating PPA-mediated appetite control. We suggest that hypothalamic ghrelin signaling system, with the help of antioxidants, may participate in NPY/CART-mediated appetite control in PPA-treated rats.

Silibinin inhibits invasion of oral cancer cells by suppressing the MAPK pathway.

Oral squamous cell carcinoma (OSCC) is the most common malignancy of the oral cavity. Here, we provide molecular evidence associated with the anti-metastatic effect of silibinin by showing a marked inhibition of the invasion and motility of SCC-4 tongue cancer cells, with 89% and 66.4% of inhibition, respectively, by 100 microM of silibinin. This effect was associated with a reduced expression of MMP-2 and u-PA, together with an enhanced expression of TIMP-2 and PAI-1. Silibinin also exerted an inhibitory effect on the phosphorylation of ERK1/2. Additionally, pre-treatment of SCC-4 cancer cells with 10 and 20 microM of U0126, a specific MEK inhibitor, resulted in a reduced expression of MMP-2 (18.7 and 51.4%) and u-PA (19.2 and 48.9%) concomitantly with a marked inhibition of cell invasion (13.7 and 45.7%). Finally, silibinin was evidenced by its inhibition of the metastasis of Lewis lung carcinoma (LLC) cells in vivo. These results suggested that silibinin can reduce the invasion and metastasis of tumor cells, and such a characteristic may be of great value in the development of a potential cancer therapy.

Central dopamine action modulates neuropeptide-controlled appetite via the hypothalamic PI3K/NF-κB-dependent mechanism.

Hypothalamic neuropeptides, including neuropeptide Y (NPY) and proopiomelanocortin (POMC), have been found to control the appetite-suppressing effect of amphetamine (AMPH). In this study, we have examined whether dopamine receptor (DAR), phosphatidylinositol 3-kinase (PI3K) and nuclear factor-kappaB (NF-κB) are involved in AMPH's action. We administered AMPH to rats once a day for 4 days and assessed and compared changes in hypothalamic NPY, melanocortin receptor 4 (MC4R), PI3K, pAkt and NF-κB expression. We found that the inhibition of DAR increased NPY, but decreased MC4R, PI3K and NF-κB expression, compared with AMPH-treated rats. Moreover, MC4R, PI3K, pAkt and NF-κB increased with the maximum response on Day 2, which was consistent with the response of feeding behavior, but was opposite to the expression of NPY. Furthermore, we found that the intracerebroventricular infusion of the PI3K inhibitor or NF-κB antisense could attenuate AMPH-induced anorexia, and partially reverse the expression of NPY, MC4R, PI3K, Akt and NF-κB back toward a normal level. We, therefore, suggest that DAR-PI3K-NF-κB signaling in the hypothalamus plays functional roles in the modulation of NPY and POMC neurotransmissions and in the control of AMPH-evoked appetite suppression.

Post-stroke wrist rehabilitation assisted with an intention-driven functional electrical stimulation (FES)-robot system.

In this work, a novel FES-robot system was developed for wrist rehabilitation training after stroke. The FES-robot system could be continuously controlled by electromyography (EMG) from the residual wrist muscles to facilitate wrist flexion and extension tracking tasks on a horizontal plane by providing assistance from both FES and robot parts. The system performance with five different assistive combinations from the FES and robot parts was evaluated by subjects with chronic stroke (n=5). The results suggested that the assistance from the robot part mainly improved the movement accuracy in the tracking tasks; and the assistance from the FES part mainly suppressed the excessive muscular activities from the elbow joint. The best combination was when the assistances from FES and robot was 1:1, and the results showed better wrist tracking performance with less muscle co-contraction from the elbow joint.

Effectiveness of functional electrical stimulation (FES)-robot assisted wrist training on persons after stroke.

A functional electrical stimulation (FES)-robot system controlled by subjects' motor intention was developed in our previous study. The effectiveness of the FES-robot on wrist training was investigated in this work. Five hemiplegic subjects with chronic stroke were recruited for an FES-robot assisted wrist training with 20 sessions. After the training, motor improvements were found in the wrist and fingers, represented by significant increase (P < 0.05) in clinical scores of the Fugl-Meyer Assessment (FMA), the Action Research Arm Test (ARAT), and the Modified Ashworth Score (MAS). Muscle coordination in the upper limb was also improved during the training as assessed by electromyography. The increased ARAT scores suggested improved upper limb motor functions, especially in the hand and fingers, compared to no improvement in previous study with only interactive robot-assisted wrist training without FES.

An intention driven hand functions task training robotic system.

A novel design of a hand functions task training robotic system was developed for the stroke rehabilitation. It detects the intention of hand opening or hand closing from the stroke person using the electromyography (EMG) signals measured from the hemiplegic side. This training system consists of an embedded controller and a robotic hand module. Each hand robot has 5 individual finger assemblies capable to drive 2 degrees of freedom (DOFs) of each finger at the same time. Powered by the linear actuator, the finger assembly achieves 55 degree range of motion (ROM) at the metacarpophalangeal (MCP) joint and 65 degree range of motion (ROM) at the proximal interphalangeal (PIP) joint. Each finger assembly can also be adjusted to fit for different finger length. With this task training system, stroke subject can open and close their impaired hand using their own intention to carry out some of the daily living tasks.

Influence of trace elements and nitrogen sources on versicolorin production by a mutant strain of Aspergillus parasiticus.

A mutant strain of Aspergillus parasiticus blocked in aflatoxin biosynthesis accumulates versicolorin A and versicolorin C. The effect of trace elements on the growth and versicolorin production by this strain was studied in a defined medium. The omission of manganese was slightly stimulatory to versicolorin production; when zinc was omitted from the medium, no detectable versicolorins were produced. Experiments on nitrogen sources in a high-sucrose medium indicated that fourfold to fivefold increases in versicolorin yields could be obtained by substituting 3 ml/l corn steep liquor or 0.1 M NH4NO3 for the 0.023 M (NH4)2SO3 used previously as the nitrogen source in studies on versicolorin production by this strain. These improved yields will facilitate attempts to accumulate enough versicolorin A and versicolorin C for toxicity and carcinogenicity testing. Chromatographic profiles of mycelial extracts of cultures grown in a defined medium with 0.1 M NH4NO3 as the nitrogen source revealed 2 previously unrecognized compounds. The accumulation of these new metabolites in a mutant blocked in aflatoxin production may indicate that they are biosynthetically related to aflatoxin.