Analysis of two quorum sensing-deficient isolates of Pseudomonas aeruginosa.

Three strains of Pseudomonas aeruginosa were isolated: wild-type (WT, NO4) showed normal quorum sensing (QS), whereas QSD3 and QSD7 were QS-deficient (QSD) containing limited N-butyryl homoserine lactone (C4-HSL). The autoinducer activity produced by NO4 was found to be at least 50-fold higher than those by the QSD3 and the QSD7 strains. The QSDs produced lower levels of phenazine compounds (pyocyanin), siderophores (pyoverdine) and biosurfactants (rhamnolipids) than NO4. Therefore, the swarming motility and the swimming motility of the QSD3 and the QSD7 strains also decreased. Treatment with exogenous C4-HSL completely restored rhamnolipid production in both QSDs, suggesting that the biosynthesis of C4-HSL is defective. However, the biofilm production of the QSDs reached much higher levels than those of wild-types (NO4 and P. aeruginosa PAO1). And both QSD strains were more resistant than wild-type cell (NO4) against kanamycin and tobramycin. The RpoS gene, which function is related with QS, is point-nonsense mutated in QSD3 strain. But eleven QS-related genes in QSD3 were not mutated, compared to those of PAO1, which carries intact QS genes and is used as a positive control. This study is helpful in the development of novel approaches in the treatment of P. aeruginosa infections.

Views of physiatrists and physical therapists on the use of gait-training robots for stroke patients.

[Purpose] Gait-training robots have been developed for stroke patients with gait disturbance. It is important to survey the views of physiatrists and physical therapists on the characteristics of these devices during their development. [Subjects and Methods] A total of 100 physiatrists and 100 physical therapists from 38 hospitals participated in our questionnaire survey. [Results] The most common answers about the merits of gait-training robots concern improving the treatment effects (28.5%), followed by standardizing treatment (19%), motivating patients about treatment (17%), and improving patients' self-esteem (14%). The subacute period (1-3 months post-stroke onset) was most often chosen as the ideal period (47.3%) for the use of these devices, and a functional ambulation classification of 0-2 was the most selected response for the optimal patient status (27%). The preferred model was the treadmill type (47.5%) over the overground walking type (40%). The most favored commercial price was $50,000-$100,000 (38.3%). The most selected optimal duration for robot-assisted gait therapy was 30-45 min (47%), followed by 15-30 min (29%), 45-60 min (18%), ≥ 60 min (5%), and < 15 min (1%). [Conclusion] Our study findings could guide the future designs of more effective gait-training robots for stroke patients.

Nobiletin protects dopaminergic neurons in the 1-methyl-4-phenylpyridinium-treated rat model of Parkinson's disease.

This study investigated the effect of nobiletin, a flavonoid found in citrus fruits, on the degeneration of dopaminergic (DA) neurons in a neurotoxin model of Parkinson's disease (PD). 1-Methyl-4-phenylpyridinium (MPP(+)) was unilaterally injected into the median forebrain bundle of rat brains (to generate a neurotoxin model of PD) with or without daily intraperitoneal injection of nobiletin. Our results showed that nobiletin treatment at 10 mg/kg bw, but not at 1 or 20 mg/kg bw, significantly protected DA neurons in the substantia nigra (SN) of MPP(+)-treated rats. In parallel to the neuroprotection, nobiletin treatment at 10 mg/kg inhibited microglial activation and preserved the expression of the glial cell line-derived neurotrophic factor, which is a therapeutic agent against PD, in the SN. These results suggest that the proper supplementation with nobiletin may protect against the neurodegeneration involved in PD.

The effect of a hand-stretching device during the management of spasticity in chronic hemiparetic stroke patients.

OBJECTIVE: To describe a hand-stretching device that was developed for the management of hand spasticity in chronic hemiparetic stroke patients, and the effects of this device on hand spasticity. METHODS: Fifteen chronic hemiparetic stroke patients with finger flexor spasticity were recruited and randomly assigned to an intervention group (8 patients) or a control group (7 patients). The stretching device consists of a resting hand splint, a finger and thumb stretcher, and a frame. In use, the stretched state was maintained for 10 minutes per exercise session, and the exercise was performed twice daily for 4 weeks. Spasticity of finger flexor muscles in the two groups was assessed 3 times, 4 weeks apart, using the Modified Ashworth Scale (MAS). Patients in the intervention group were assessed twice (pre-1 and pre-2) before and once (post-1) after starting the stretching program. RESULTS: Mean MAS (mMAS) scores at initial evaluations were not significantly different at pre-1 in the intervention group and at 1st assessment in the control group (p>0.05). In addition, no significant differences were observed between mMAS scores at pre-1 and pre-2 in the intervention group (p>0.05). However, mMAS scores at post-1 were significantly lower than that at pre-2 in the intervention group (p<0.05). Within the control group, no significant changes in mMAS scores were observed between 1st, 2nd, and 3rd assessments (p>0.05). In addition, mMAS scores at post-1 in the intervention group were significantly decreased compared with those at the 3rd assessment in the control group (p<0.05). CONCLUSION: The devised stretching device was found to relieve hand spasticity effectively in chronic hemiparetic stroke patients.