Developmental characteristics and response to iron toxicity of root border cells in rice seedlings

To investigate the Fe^2＋ effects on root tips in rice plant, experiments were carried out using border cells in vitro. The border cells were pre-planted in aeroponic culture and detached from root tips. Most border cells have a long elliptical shape. The number and the viability of border cells in situ reached the maxima of 1600 and 97.5%, respectively, at 20---25 mm root length. This mortality was more pronounced at the first 1-12 h exposure to 250 mg/L Fe^2＋ than at the last 12-36 h. After 36 h, the cell viability exposed to 250 mg/L Fe^2＋ decreased to nought, whereas it was 46.5% at 0 mg/L Fe^2＋. Increased Fe^2＋ dosage stimulated the death of detached border cells from rice cultivars. After 4 h Fe^2＋ treatment, the cell viabilities were _〉80% at 0 and 50 mg/L Fe^2＋ treatment and were 〈62% at 150, 250 and 350 mg/L Fe^2＋ treatment; The viability of border cells decreased by 10% when the Fe^2＋ concentration increased by 100 mg/L. After 24 h Fe^2＋ treatment, the viabilities of border cells at all the Fe^2＋ levels were 〈65%; The viability of border cells decreased by 20% when the Fee＋ concentration increased by 100 mg/L. The decreased viabilities of border cells indicated that Fe^2＋ dosage and treatment time would cause deadly effect on the border cells. The increased cell death could protect the root tips from toxic harm. Therefore, it may protect root from the damage caused by harmful iron toxicity.

Visual feedback therapy for restoration of upper limb function of stroke patients

Objective:To investigate the effects of mirror neuron theory-based visual feedback therapy(VFT)on restoration of upper limb function of stroke patients and motor-related cortical function using functional magnetic resonance imaging(fMRI).Methods:Hemiplegic stroke patients were randomly divided into two groups:a VFT group and a control(CTL)group.Sixteen patients in the VFT group received conventional rehabilitation(CR)and VFT for 8 weeks,while 15 patients in the CTL group received only CR.The Barthel Index(BI)was used to assess the activities of daily living at baseline and the 8th week of the recovery training period.The Fugl-Meyer assessment(FMA)scale,somatosensory evoked potential(SEP),and fMRI were used to evaluate the recovery effect of the training therapies.The latencies and amplitudes of N9 and N20 were measured.Before recovery training,fMRI was performed for all patients in the VFT and CTL groups.In addition,17 patients(9 in the VFT group and 8 in the CTL group)underwent fMRI for follow-up 2 months after treatment.Qualitative data were analyzed using the x2 test.The independent sample t-test was used to compare normally distributed data among different groups,the paired sample t-test was used to compare data between groups,and the non-parametric test was used to comparing data without normal distribution among groups.Results:There were no significant differences between the VFT and CTL group in all indexes.However,after 8 weeks of recovery training,these indexes were all significantly improved(P<0.05).As compared with the CTL group,the FMA scores,BI,and N9/N20 latencies and amplitudes of SEP in the VFT group were significantly improved(P<0.05).Two months after recovery training,fMRI showed that the degree of activation of the bilateral central anterior gyrus.parietal lobe,and auxiliary motor areas was significantly higher in the VFT group than the CTL group(P<0.05).Conclusions:VFT based on mirror neuron theory is an effective approach to improve upper extremity motor function and daily activity performance of stroke patients.The therapeutic mechanism promotes motor relearning by activating the mirror neuron system and motor cortex.SEP amplitudes increased only for patients who participated in visual feedback.VFT promotes sensory-motor plasticity and behavioral changes in both the motor and sensory domains.

Effect of action observation therapy on daily activities and motor recovery in stroke patients

Objective:To evaluate the effects of action observation therapy,which is based on mirror neuron theory,on upper limb function and activities of daily living in patients with stroke.Methods:Sixty-one patients with stroke were randomly divided into two groups;those in the control group received routine rehabilitation treatment and nursing,whereas those in the experimental group additionally received eight weeks of action observation therapy for 30 min,six times per week.Patients receiving action observation therapy watched videos depicting a model performing specific motor actions typically performed in daily life before enacting the same actions themselves.All patients were assessed using the FugleMeyer assessment,Barthel index and the modified Ashworth scale at baseline and at eight weeks,after treatment.Results:After the eight weeks of treatment,both groups of patients exhibited significant improvement in all the measurements(all p<0.05).Furthermore,the FugleMeyer assessment,Barthel index and modified Ashworth scale scores were significantly higher in the experimental group compared to the control group(all p<0.05).Conclusion:Action observation therapy significantly improves upper extremity motor function and performance of activities of daily living,and alleviates upper limb spasticity in patients with stroke.