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Background: Canes are usually prescribed for individuals with stroke with the purpose of improving walking and increasing safety. However, there is no consensus regarding the clinical effects of these aids on walking and participation. Objective: This study will examine the efficacy of the provision of a cane to improve walking and increase participation after stroke. Methods: This is a two-arm, prospectively registered, randomized trial with concealed allocation, blinded measurers, and intention-to-treat analysis. Fifty individuals with chronic stroke, categorized as slow or intermediate walkers (walking speeds ≤0.8 m/s), will participate. The experimental group will receive a single-point cane and instructions to use the cane anytime they need to walk. The control group will receive a placebo intervention, consisting of selfstretching exercises of the lower limb muscles and instructions to not use assistive devices. The primary outcome will be comfortable walking speed. Secondary outcomes will include walking step length, walking cadence, walking capacity, walking confidence, and participation. Outcomes will be collected by a researcher blinded to group allocation at baseline (Week 0), after intervention (Week 4), and one month beyond intervention (Week 8). Conclusion: The provision of a single-point cane may help improving walking of slow and intermediate walkers after stroke. If walking is enhanced, the benefits may be carried over to participation, and individuals may experience greater free-living physical activity at home and in the community. [ABSTRACT FROM AUTHOR]

Objective: To investigate the influence of hand dominance on the maintenance of gains after home-based modified constraint-induced movement therapy (mCIMT). Method: A previous randomized controlled trial was conducted to examine the addition of trunk restraint to the mCIMT. Twenty-two chronic stroke survivors with mild to moderate motor impairments received individual home-based mCIMT with or without trunk restraints, five times per week, three hours daily over two weeks. In this study, the participants were separated into dominant group, which had their paretic upper limb as dominant before the stroke (n=8), and non-dominant group (n=14) for analyses. The ability to perform unimanual tasks was measured by the Wolf Motor Function Test (WMFT) and the Motor Activity Log (MAL), whereas the capacity to perform bimanual tasks was measured using the Bilateral Activity Assessment Scale (BAAS). Results: Analysis revealed significant positive effects on the MAL amount of use and quality of the movement scales, as well as on the BAAS scores after intervention, with no differences between groups. Both groups maintained the bimanual improvements during follow-ups (BAAS-seconds 0.1, 95% CI –10.0 to 10.0), however only the dominant group maintained the unilateral improvements (MAL-amount of use: 1.5, 95% CI 0.7 to 2.3; MAL-quality: 1.3, 95% CI 0.5 to 2.1). Conclusions: Upper limb dominance did not interfere with the acquisition of upper limb skills after mCIMT. However, the participants whose paretic upper limb was dominant demonstrated better abilities to maintain the unilateral gains. The bilateral improvements were maintained, regardless of upper limb dominance. [ABSTRACT FROM AUTHOR]

Objectives: To examine the strength deficits of the shoulder complex after stroke and to characterize the pattern of weakness according to type of movement and type of isokinetic parameter. Method: Twelve chronic stroke survivors and 12 age-matched healthy controls had their shoulder strength measured using a Biodex isokinetic dynamometer. Concentric measures of peak torque and work during shoulder movements were obtained in random order at speeds of 60°/s for both groups and sides. Type of movement was defined as scapulothoracic (protraction and retraction), glenohumeral (shoulder internal and external rotation) or combined (shoulder flexion and extension). Type of isokinetic parameter was defined as maximum (peak torque) or sustained (work). Strength deficits were calculated using the control group as reference. Results: The average strength deficit for the paretic upper limb was 52% for peak torque and 56% for work. Decreases observed in the non-paretic shoulder were 21% and 22%, respectively. Strength deficit of the scapulothoracic muscles was similar to the glenohumeral muscles, with a mean difference of 6% (95% CI -5 to 17). Ability to sustain torque throughout a given range of motion was decreased as much as the peak torque, with a mean difference of 4% (95% CI -2 to 10). Conclusions: The findings suggest that people after stroke might benefit from strengthening exercises directed at the paretic scapulothoracic muscles in addition to exercises of arm elevation. Clinicians should also prescribe different exercises to improve the ability to generate force and the ability to sustain the torque during a specific range of motion. [ABSTRACT FROM AUTHOR]

Reports of abuse and toxic effects of synthetic cathinones, frequently sold as 'bath salts' or 'legal highs', have increased dramatically in recent years. One of the most widely used synthetic cathinones is 3,4-methylenedioxypyrovalerone (MDPV). The current study evaluated the abuse potential of MDPV by assessing its ability to support intravenous self-administration and to lower thresholds for intracranial self-stimulation (ICSS) in rats. In the first experiment, the rats were trained to intravenously self-administer MDPV in daily 2-hour sessions for 10 days at doses of 0.05, 0.1 or 0.2 mg/kg per infusion. The rats were then allowed to self-administer MDPV under a progressive ratio (PR) schedule of reinforcement. Next, the rats self-administered MDPV for an additional 10 days under short access (ShA; 2 hours/day) or long access (LgA; 6 hours/day) conditions to assess escalation of intake. A separate group of rats underwent the same procedures, with the exception of self-administering methamphetamine (0.05 mg/kg per infusion) instead of MDPV. In the second experiment, the effects of MDPV on ICSS thresholds following acute administration (0.1, 0.5, 1 and 2 mg/kg, i.p.) were assessed. MDPV maintained self-administration across all doses tested. A positive relationship between MDPV dose and breakpoints for reinforcement under PR conditions was observed. LgA conditions led to escalation of drug intake at 0.1 and 0.2 mg/kg doses, and rats self-administering methamphetamine showed similar patterns of escalation. Finally, MDPV significantly lowered ICSS thresholds at all doses tested. Together, these findings indicate that MDPV has reinforcing properties and activates brain reward circuitry, suggesting a potential for abuse and addiction in humans. [ABSTRACT FROM AUTHOR]

Intestinal alkaline phosphatase (IAP) is a brush-border phosphomonoesterase. Its location suggests an involvement in the uptake of nutrients, but its role has not yet been defined. IAP expression parallels that of other proteins involved in Ca absorption under vitamin D stimulation. Experiments carried out in vitro with purified IAP have demonstrated an interaction between Ca and IAP. The gut is prepared to face different levels of Ca intake over time, but high Ca intake in a situation of a low-Ca diet over time would cause excessive entry of Ca into the enterocytes. The presence of a mechanism to block Ca entry and to avoid possible adverse effects is thus predictable. Thus, in the present study, Sprague–Dawley rats were fed with different amounts of Ca in the diet (0·2, 1 and 2 g%), and the percentage of Ca absorption (%Ca) in the presence and absence of l-phenylalanine (Phe) was calculated. The presence of Phe caused a significant increase in %Ca (52·3 (sem 6·5) % in the presence of Phe v. 31·1 (sem 8·9) % in the absence of Phe, regardless of the amount of Ca intake; paired t test, P = 0·02). When data were analysed with respect to Ca intake, a significant difference was found only in the group with low Ca intake (paired t test, P = 0·03). Additionally, IAP activity increased significantly (ANOVA, P < 0·05) as Ca concentrations increased in the duodenal lumen. The present study provides in vivo evidence that luminal Ca concentration increases the activity of IAP and simultaneously decreases %Ca, acting as a minute-to-minute regulatory mechanism of Ca entry. [ABSTRACT FROM PUBLISHER]

Objective: To evaluate the effects of different instructions for the assessment of maximum walking speed during the ten-meter walking test with chronic stroke subjects. Methods: Participants were instructed to walk under four experimental conditions: (1) comfortable speed, (2) maximum speed (simple verbal command), (3) maximum speed (modified verbal command–“catch a bus”) and (4) maximum speed (verbal command + demonstration). Participants walked three times in each condition and the mean time to cover the intermediate 10 meters of a 14-meter corridor was registered to calculate the gait speed (m/s). Repeated-measures ANOVAs, followed by planned contrasts, were employed to investigate differences between the conditions (α=5%). Means, standard deviations and 95% confidence intervals (CI) were calculated. Results: The mean values for the four conditions were: (1) 0.74m/s; (2) 0.85 m/s; (3) 0.93 m/s; (4) 0.92 m/s, respectively, with significant differences between the conditions (F=40.9; p<0.001). Comfortable speed was significantly slower than the maximum speed, indicating that the participants were able to increase speeds when required. Significant differences were observed between the second condition with the third (p=0.002; 95%CI=-0.13 to -0.03) and the fourth conditions (p=0.004; 95%CI=-0.12 to -0.02) with no differences between the third and fourth conditions (p=1.00; 95%CI=-0.04 to 0.05). Conclusions: The results indicated that simple verbal commands were not sufficient to capture maximum gait speed with chronic stroke subjects. Thus, for clinical assessments and research purposes, where measurements of the maximum gait speed are necessary, modified verbal commands or demonstration strategies could be employed by physical therapists to ensure accurate information. [ABSTRACT FROM AUTHOR]

The control of body temperature in Spontaneously Hypertensive Rat (SHR) subjected to exercise in warm environment was investigated. Male SHR and Wistar rats were submitted to moderate exercise in temperate (25°C) and warm (32°C) environments while body and tail skin temperatures, as well as oxygen consumption, were registered. Total time of exercise, workload performed, mechanical efficiency and heat storage were determined. SHR had increased heat production and body temperature at the end of exercise, reduced mechanical efficiency and increased heat storage (p < 0.05). Furthermore, these rats also showed a more intense and faster increase in body temperature during moderate exercise in the warm environment (p < 0.05). The lower mechanical efficiency seen in SHR was closely correlated with their higher body temperature at the point of fatigue in warm environment (p < 0.05). Our results indicate that SHR exhibit significant differences in body temperature control during moderate exercise in warm environment characterized by increased heat production and heat storage during moderate exercise in warm environment. The combination of these responses result in aggravated hyperthermia linked with lower mechanical efficiency. [ABSTRACT FROM AUTHOR]