Stromal vascular fraction (SVF) cells, and the adipose-derived mesenchymal stem cells they contain, have shown enhanced wound healing in vitro and in vivo, yet their clinical application has been ...limited. In this regard, understanding the mechanisms that govern SVF-enhanced wound healing would improve their application in the clinic. Here, we show that the SVF cells and keratinocytes engage in a paracrine crosstalk during wound closure, which results in a new cytokine profile that is distinct from the cytokines regularly secreted by either cell type on their own. We identify 11 cytokines, 5 of which are not regularly secreted by the SVF cells, whose expressions are significantly increased during wound closure by the keratinocytes. This new cytokine profile could be used to accelerate wound closure and initiate re-epithelialization without the need to obtain the SVF cells from the patient.
The scratch assay is an in vitro assay that allows for high-throughput quantification of wound closure by keratinocytes and fibroblasts with relative ease. However, this assay is amenable to ...experimental variables, which can result in false-positive and false-negative data, making the interpretation of such data difficult. Also, data variability decreases the sensitivity of the scratch assay. Here, we identify important sources of data variation in the scratch assay and provide rational mitigation strategies that enable robust and highly reproducible quantification of scratch width and area, and ultimately the scratch closure rates. By eliminating these sources of variability, the sensitivity of the scratch assay is enhanced, thereby allowing for identification of dependent variables with wide-ranging impacts on wound closure in a robust and standardized manner.
This study was aimed at comparing the force–velocity relationship during cycling and arm cranking in males and females. Thirty-two male and twenty-two female healthy volunteers performed a ...force–velocity test on a cycle ergometer and a cranking ergometer in a randomly selected order. The theoretical values of the maximum force at zero speed (F0) and the maximum velocity at zero braking force (v0) for the lower and upper limbs were determined, and the maximum anaerobic power (Pmax) was calculated from the individual force–velocity relationship. The Pmax and F0 of the upper limbs related to the lower limbs correspond to 78.2 ± 14.3% and 80.1 ± 17.3% in men and 65.5 ± 12.5% and 74.5 ± 6.5% in women, respectively. The theoretical maximum velocity v0 of the upper limbs to the lower limbs attained 129.1 ± 29.0% in men and 127.4 ± 26.4% in women. The results of the study can serve as reference data for the force–velocity characteristics of the upper and lower limbs of male and female athletes. The results can be used both in training and rehabilitation programs, where the starting point is the objectification of possible strength deficits in various areas of the force–velocity characteristic spectrum of the muscles of the upper and lower limbs.
The purpose of the present study was to determine if it is possible to affect the level of simple (SRT) and choice (CRT) reaction time of fencers with a specific 9-week (in total 350 minutes) ...training intervention. The research sample consisted of 19 healthy fencers (12 boys, 16±1.1 years and 7 girls, 16.4±0.9 years). Five of the tested subjects were selected as the control group that did not participate in the reaction time training. The training of the experimental group was conducted on an Electronic Fencing Target (EFT1). All tested individuals completed an entrance and exit reaction time test on the Fitrosword device, which consisted of hitting the target with an epée from the guard position after lighting of an LED light (green, red, yellow) by using various motor responses of the armed arm. No difference in reaction time (SRT, CRT) was found between the experimental and control groups for the entrance test. A significant difference between groups was found for results of the CRT (p = 0.116, d = 0.722) after the 9-week training. A significant difference in CRT was also found between the entrance and the exit tests in the experimental group (p = 0.013, r = 0.469). This difference was not significant in the case of the control group (p = 0.345, r = 0.298). Based on these results, we can assume a positive impact of specific reaction time training on response speed. We can use these results in the training process to improve reaction time, which is an important component of overall sports performance in many combat disciplines, such as karate, boxing, taekwondo, judo, and fencing, as well as motorsports, ball games, etc.
The assumption of this work is the achievement of objective results of the movement structure, which forms the basis for in-depth analysis and, consequently, for determining the upper limb movements ...that are most affected by stroke compared to healthy people.
An analysis of relevant and systematically identified features of upper limb movement in post-stroke adults is presented based on scalable hypothesis tests. The basic features were calculated using movements defined by the x, y, and z coordinates (i.e., 3D trajectory time series) and compared to the results of post-stroke patients with healthy controls of similar age.
After automatic feature selection, out of the 1004 common features of upper limb movement, the most differentiated were the upper arm movements in reaching kinematics. In terms of movement type, movements in the frontal plane (shoulder abduction and adduction) were the most sensitive to changes. The largest number of discriminating features was determined on the basis of acceleration time series.
In the 3D assessment of functional activities of the upper limb, the upper arm turned out to be the most differentiated body segment, especially during abduction and adduction movements. The results indicate a special need to pay attention to abduction and adduction movements to improve the activities of daily living of the upper limbs after a stroke.
Objective: This study aimed to assess the relative load of the midfoot and the metatarsals of both feet when schoolchildren walked with backpacks of different loads. Methods: A group of 12 healthy ...girls (9.9 ± 0.8 years; 33.8 ± 6.7 kg, 1.40 ± 0.10 m) walked barefoot to assess plantar pressures during gait without load (L0%) and with a loaded backpack equal to 10% (L10%) and 20% (L20%) of their body weight. A Footscan® system (RSscan International, Belgium) was used to determine the contact area and relative pressure impulse in the midfoot and metatarsals on the dominant (DL) and non-dominant legs (NL). Results: The effect of load was significant for the contact area of the midfoot for both NL (p = 0.013) and DL (p = 0.001). In the metatarsals, there was significantly greater relative impulse during L10% compared to L0% in the first (p = 0.041) and second (p = 0.050) metatarsals of the DL. Comparing the NL and DL showed significantly greater relative impulse on the DL in the fourth metatarsal during L10% (p = 0.023), greater contact area in the fifth metatarsal during L0% (p=0.050), and greater impulse in the midfoot during L20% (p=0.028) on the NL. Conclusions: The school backpack load influences relative plantar pressure distribution, especially in the midfoot. Further, our findings suggest greater propulsion of the DL and supporting function of the NL.
The present work studied potential differences in activation times of selected muscles associated with the motor responses of the armed arm and differences in selected muscle pairs activation during ...the fencing lunge. Twenty-eight fencers (epée fencers, aged 22.1 ± 5.4 years) grouped into elite and beginning skill levels, participated in this study. Surface electromyography was used to determine muscle activation time (time period measured from visual stimulus occurrence to the moment of muscle activation threshold detection). For motor response, we measured the time between visual stimulus occurrence and armed arm movement. A significant difference was found between elite and beginning fencers in the motor response of the armed arm. Detection of armed arm’s motor response was significantly later in beginners. Greater time disparities between arm’s motor response and muscle activation time of the m. rectus femoris on the front/lunge side was also found in beginners. Lastly, difference was detected between elite and beginning fencers regarding the muscle activation time of selected muscle pairs. Future studies and trainers can use these results to further explore key areas of motor control and biomechanics for improving of fencing performance.
DOI: http://dx.doi.org/10.5007/1980-0037.2016v18n4p391 In many sport disciplines reaction time plays a key role in the sport performance. It is good to point out for example ball games or fighting ...sports (fencing, karate etc.). The research is focused on detection of the differences in the simple and choice reaction time during visual stimulation among elite, sub-elite fencers and beginners. For the measurement a Fitrosword device and the SWORD software were used. An additional stimulus was added during measuring which should increase the overall number of stimuli, but shouldn’t force fencer to any reaction whatsoever. The results from presented study can be compared with Hicks law. The next focus of the study was to identify the difference in reaction time during two different movement tasks with different complexity movement requirements. The research was built up on a hypothesis that the results will differ among different performance groups of fencers. The difference however was overt among beginners and elite fencers (p = 0.0088, d = 0.5) in reaction time during different movement tasks (direct hit vs. lunge). The results of this research could be useful to trainers for training process organisation and increase the effectivity of muscle coordination during several movements in fencing.
PDF
