Aim. To investigate how starvation during early stage of fly development affects carbohydrate metabolism in imago flies and their progeny of F1 generation. Methods. Wild-type Canton-S strain ...Drosophila melanogaster flies were used in all experiments. Flies of parental and offspring generations were used for the determination of glycogen and glucose content using the diagnostic kit Glucose-Mono-400-P according to the manufacturer's instructions. Results represent as the mean ± SEM of 3-4 replicates per group. According Student's t-test significant difference between groups was P<0.05. Graphing and statistical analysis were performed by using GraphPad Prism. Results. Starvation during development significantly influenced the level of hemolymph and body glucose in imago flies of parental generation. Hemolymph glucose concentration was lower by 34% (P=0.008) and 32% (P=0.033) in experimental females and males, respectively, as compared to control groups. Starvation during development led to lower level of body glucose in adult parental flies of both sexes. Adult males F1, generated by parents that were starved during development, showed 3-fold lower glycogen content, as compared to control. Conclusions. Starvation at early stage of development led to lower hemolymph glucose and body glucose level in imago flies. Moreover, parental starvation decreased glycogen pool in F1 males.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
The purpose of the paper is to determine the differences in the technique of body inrun position at the beginning of take-off in junior ski jumpers of different qualifications (athletic ...preparedness).
Materials and methods. The study participants were 22 junior ski jumpers aged 14-15 (a group of junior ski jumpers) during the Ukrainian Ski Jumping Championship (October 9, 2010, Vorokhta, Ukraine) and 33 ski jumpers aged 16-17 (a group of senior ski jumpers) who took part in the international competitions “Lotos Cup” in January 2010. The study analyzed the videos of take-offs of 22 athletes aged 14-15 and 33 athletes aged 16-17. The parameters of ski jumping technique and sports results were processed on the basis of video materials of the first competition series.
Results. There are significant differences (p < 0.001) in the mean values of corresponding parameters of the body position at the beginning of take-off. The data point to a tighter tuck of the body of the athletes aged 16-17. The structure coefficients of the first canonical discriminant function indicate that the function is most significantly related to the values of angles 10 (ν); 8 (ζ); 6 (θ): the inclination angle of the segment of the straight line passing through the axes of the hip and ankle joints (ν) towards the direction of the skier’s movement; the inclination angle of the segment of the straight line passing through the general center of body weight and the axis of the ankle joint (ζ) towards the direction of the skier’s movement; the inclination angle of the head towards the trunk (θ). The athletes aged 16-17 differ from the athletes aged 14-15 by the parameters characterizing the body’s tuck in the starting position – the position at the beginning of take-off.
Conclusions. The unstandardized canonical discriminant function coefficients can be used to classify the levels of proficiency in the body’s tuck in the starting position – the position at the beginning of take-off in athletes aged 14-17.
Objective. To quantify the effects of posting and custom-molding of foot orthotics on lower extremity kinematics and kinetics during running.
Design. Repeated measures.
Background. Several kinematic ...and kinetic factors have been suggested to increase a runner’s risk for injuries. It has been speculated that foot orthotics can be used to reduce injury related complaints or even prevent running injuries by affecting these factors.
Methods. Twenty one volunteers participated in this study. Kinematic and kinetic variables obtained during overground running for medial posting, custom-molding, and the combination of medial posting and custom-molding of foot orthotics were compared to a control condition. Repeated measures
anova and student
t-tests were used to detect significant differences (
α=0.05).
Results. Posting of foot orthotics reduced maximum foot eversion and ankle inversion moment and increased vertical loading rate and maximum knee external rotation moment (
P<0.05). Molding and posting and molding reduced vertical loading rate and ankle inversion moment and increased maximum foot inversion and maximum knee external rotation moment (
P<0.05).
Conclusions. The effects of posting and molding of foot orthotics are extremely different and when combining posting and molding, the effects of molding appear to be dominant. It yet remains to be determined whether posting or molding is more beneficial with respect to overuse running injuries.
Relevance The potential of foot orthotics for reducing pain and injuries is convincing. The current study provides valuable information about the role of specific structural components of foot orthotics and contributes to the knowledge about the mechanism underlying the effect of foot orthotics in running.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
The purpose of this study was to determine the relationship between differences in comfort and changes in lower extremity kinematic and kinetic variables and muscle activity in response to foot ...orthoses.
Twenty-one recreational runners volunteered for this study. Three orthotic conditions (posting, custom-molding, and posting and custom-molding) were compared with a control (flat) insert. Lower extremity kinematic, kinetic, and EMG data were collected for 108 trials per subject and condition in nine sessions per subject for overground running at 4 m.s-1. Comfort for all orthotic conditions was assessed in each session using a visual analog scale. The statistical tests used included repeated measures ANOVA, linear regression analysis, and discriminant analysis (alpha = 0.05).
Comfort ratings were significantly different between orthotic conditions and the control condition (lower, upper confidence limits; posting: -3.1, -0.8; molding: 0.4, 3.4; and posting and molding: -1.1, 1.9); 34.9% of differences in comfort were explained by changes in 15 kinematic, kinetic, and EMG variables. The 15 kinematic, kinetic, and EMG variables that partially explained differences in comfort classified 75.0% of cases correctly to the corresponding orthotic condition.
In general, comfort is an important and relevant feature of foot orthoses. Evaluations of foot orthoses using comfort do not only reflect subjective perceptions but also differences in functional biomechanical variables. Future research should focus on defining the relationship between comfort and biomechanical variables for material modifications of footwear, different modes of locomotion, and the general population.
Parental dietary nutrients epigenetically influence offspring metabolism. Our analysis revealed unforeseen patterns in how enzymes of the main metabolic pathways respond to protein content in the ...diet. We reared parental flies Drosophila melanogaster on four types of diet with different dry yeast concentrations ranging from 0.25% to 15%. The subsequent generation was fed by the same diet, so the only variable in the experiments was the yeast concentration in the parental diet. We showed that protein restriction in the parental diet led to higher lactate dehydrogenase (LDH) activity in parents, and this effect was inherited in their progeny. The transgenerational effect of parental dietary yeast on malate dehydrogenase (MDH) activity was found only in males. An elevated level of dietary yeast was sufficient to enhance alanine transaminase ( ALT) and aspartate transaminase (AST) activity in parents, however, did not affect ALT activity and decreased AST in their offspring. A low yeast parental diet was shown to cause higher urea content in F1 males. It is concluded that parental dietary yeast plays a critical role in metabolic health that can be inherited through generation.Parental dietary nutrients epigenetically influence offspring metabolism. Our analysis revealed unforeseen patterns in how enzymes of the main metabolic pathways respond to protein content in the diet. We reared parental flies Drosophila melanogaster on four types of diet with different dry yeast concentrations ranging from 0.25% to 15%. The subsequent generation was fed by the same diet, so the only variable in the experiments was the yeast concentration in the parental diet. We showed that protein restriction in the parental diet led to higher lactate dehydrogenase (LDH) activity in parents, and this effect was inherited in their progeny. The transgenerational effect of parental dietary yeast on malate dehydrogenase (MDH) activity was found only in males. An elevated level of dietary yeast was sufficient to enhance alanine transaminase ( ALT) and aspartate transaminase (AST) activity in parents, however, did not affect ALT activity and decreased AST in their offspring. A low yeast parental diet was shown to cause higher urea content in F1 males. It is concluded that parental dietary yeast plays a critical role in metabolic health that can be inherited through generation.
The purpose of this study was to quantify the effects of selected foot orthoses on muscle activity in the lower extremity during running. Nine male and 12 female recreational runners, clinically and ...functionally classified as ‘pronators’, volunteered for this study and performed over-ground running trials at 4
m/s in each of four experimental conditions: control, posting, molding, and posting & molding. Electromyographic (EMG) signals were recorded from seven lower extremity muscles. Wavelet analysis was performed to obtain EMG intensities in two frequency bands that were averaged for the pre-heel-strike and post-heel-strike intervals and for 30–100% of stance phase. Posting and custom-molding of foot orthoses increased the global EMG intensity of most muscles of the lower extremity for the stance phase of running (
P
<
0.05). The increases in EMG intensity were greater in the high- than in the low-frequency bands for some lower extremity muscles (
P
<
0.05). The effects on muscle activity of posting and custom-molding of foot orthoses differed between the three phases of running gait. The three tested foot orthoses did affect lower extremity muscle activity differently and these effects were specific to the phases of running gait. Combinations of increased requirements of controlling joint motion and minimizing soft tissue vibrations may have led to greater increases in shank muscle activity for the posted condition. The substantial changes in EMG due to orthotic interventions found in this study documents the importance of the study of muscle activity as a reaction to shoe inserts and foot orthoses.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
The purposes of this study were: (a) to determine whether subjects are able to distinguish between differences in footwear with respect to footwear comfort; and (b) to determine how reliably footwear ...comfort can be assessed using a visual analogue scale (VAS) and a protocol including a control condition during running. Intraclass correlation coefficients (ICCs) between comfort ratings for repeated conditions were high (ICC=0.799). Differences in comfort ratings between the insert conditions were significant. A paired
t-test revealed a significant difference in overall comfort ratings for the control insert when tested after the soft insert compared to when tested after the hard insert (
P=0.008). The results of this study showed that VASs provide a reliable measure to assess footwear comfort during running under the conditions that: (a) a control condition is included; and (b) the average comfort rating of sessions 4–6 is used.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
The purposes of this project were to assess the effect of four different shoe inserts on the path of the center of pressure (COP), to quantify the effect of these inserts on selected knee joint ...moments during running, and to assess the potential of COP data to predict the effects of inserts/orthotics on knee joint moments.
Kinematics for the lower extremities, resultant ankle and knee joint moments, and the path of the COP were collected from the right foot of 15 male subjects while running heel-toe with five different shoe inserts (full or half with 4.5-mm postings).
Individual movement changes with respect to the neutral insert condition were typically small and not systematic. Significant changes for the path of the COP were registered only for the full lateral insert condition with an average shift toward the lateral side. The mediolateral shift of the COP was not consistent for the full medial and the two half-shoe inserts. The subject-specific reactions to the inserts' intervention in the corresponding knee joint moments were typically not consistent. Compared with the neutral insert condition, subjects showed increases or decreases of the knee joint moments. The correlation between the individual COP shifts and the resultant knee joint moment was generally small.
The results of this study showed that subject-specific reactions to the tested inserts were often not as expected. Additionally, reactions were not consistent between the subjects. This result suggests that the prescription of inserts and/or orthotics is a difficult task and that methods must be developed to test and assess these effects. Such methods, however, are not currently available.
This paper presents an up-to-date review of research data on the specific features of lactic acid metabolism and its role as an effector of vital regulatory mechanisms. Lactic acid is an ...alpha-hydroxy monocarboxylic acid. Physical loads of submaximal intensity and some diseases can cause dramatic increase of lactic acid content in the body fluids. The excessive lactate is removed from the working muscle and either metabolized by other tissues or excreted from the human body. Alteration of the lactate-pyruvate balance is one of the main markers of the development of cardiac hypertrophy and failure. The redistribution of lactate between the cells producing it and the cells that metabolize it is vital to maintain a stable pH level in tissues and hold lactate in the body since this compound is an important energy source as well as an effector of important regulatory mechanisms. The quantification of lactate is used to assess general physical capabilities of the human body, the intensity of physical load and the rate of recovery in physical rehabilitation. Specialized proteins, which refer to the group of monocarboxylate transporters, are involved in lactate excretion and absorption by cells. The presence of various types of transporters in cell membranes that differ in affinity to lactate and the direction of transport ensures a rapid redistribution of lactic acid throughout the body and regulates the intensity and direction of its metabolism according to the physiological needs. Efficient transfer and redistribution of lactate between different tissues of the body is essential, given the participation of lactate in several important regulatory mechanisms. As an effector, lactate is involved in the regulation of angiogenesis, differentiation of myosatellitocytes, regeneration of muscle fibers, polarization of macrophages and the course of inflammatory processes. Besides, lactate participates in epigenetic mechanisms of muscle tissue metabolism regulation. Therefore, lactate is one of the key metabolites in the human body.
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