Micrornas as diagnostic and prognostic biomarkers

The intensive development of molecular biology and biochemistry in recent years has allowed the disclosure of intimate mechanisms of a number of processes in the cell. Numerous molecules have become useful tools for diagnosing and predicting a number of diseases. These are, for example, the small, non-coding micro RNAs (miRNAs). It was found that the majority of protein-coding genes contain miRNA-binding sites under selective pressure (1) that make them the master regulators of cellular processes. Thu

ALPHA-FIT TEST BATTERY NORMS FOR CHILDREN AND ADOLESCENTS FROM 5 TO 18 YEARS OF AGE OBTAINED BY A LINEAR INTERPOLATION OF EXISTING EUROPEAN PHYSICAL FITNESS REFERENCES

Physical fitness has been shown to be a major health factor in both children and adolescents. One of the most widely applied physical fitness test batteries in Europe is the Alpha-fit. However, there is a reference gap between some of the ages. The aim of this study was to propose interpolated physical fitness percentile scores in children and adolescents for the main tests in the Alpha-fit test battery, which can be temporarily applied until this gap is filled in by experimental research. The recently available existing European normative values for children and adolescents were linearly interpolated in order to propose percentile scores to close the gap from 9.9 to 12.9 years of age in relation to the following tests: handgrip strength, standing long jump, and 4x10m shuttle run test (SRT). Similarly, other international references were combined with regard to the 20m SRT in order, thereby, to produce a full set of norms with the appropriate interpolations. The interpolated percentile scores obtained can be applied to assess the results from the Alpha-fit test battery of children and adolescents from 5 to 18 years of age. The combined percentile curves for handgrip strength, standing long jump, 4x10m SRT, and 20m SRT showed linearity, which sharpens between the ages of 9 and 13, and is probably connected with puberty. The proposed combined and interpolated reference values can be applied in order to evaluate European children and adolescents of all ages until the missing values are established by experimental research.  Article visualizations: Note: Please click on the image for acceessing the video presentation at the 13th European & 29th World FIEP Congress in Istanbul, Turkey or access the link STK SPORT: https://www.stk-sport.co.uk. 

Dynamics of oxidative status in patients with paroxysmal atrial fibrillation

Introduction: Studies have established oxidative disorders in persistent and permanent atrial fibrillation. Our aim was to investigate oxidative status still in the early hours of paroxysmal atrial fibrillation (PAF) and monitor its changes after sinus rhythm (SR) restoration. Material and Methods: Levels of malondialdehyde and total glutathione were determined in plasma (Pl-MDA; Pl-GSH) and erythrocytes (Er-MDA; Er-GSH) together with erythrocyte glutathione peroxidase activity (GSH-Px) in 51 patients (59.84±1.6 years, 26 males). Markers were investigated upon hospital admission, 24 hours and 28 days after SR restoration. They were also determined in 52 healthy subjects (59.50±1.46 years, 26 males). Results: Mean AF duration prior to hospitalization was 8.14±0.76 hours. Upon admission, Pl-MDA and Er-MDA were significantly increased (p0.05). Conclusion: Disorder of oxidative status is detected in the early hours of PAF, which persists after SR restoration. Oxidative balance is restored slowly with time. This specific dynamics of oxidative status is most likely related to AF clinical course, namely to its manifestation and recurrences

The effect of elbow position on the handgrip strength test in children: validity and reliability of TKK 5101 and DynX dynamometers

Purpose: One of the most widely applied methods to assess upper-body strength in children and adolescents is the handgrip strength test. While in adolescents it has been determined which elbow position, and which type of dynamometer are most appropriate for achieving the maximal grip strength, in children is still not clear. Therefore, the purpose of this study was to investigate whether elbow position and the type of dynamometer affect the handgrip strength in children. Material: Grip strength was measured by TKK and DynX dynamometers, and their validity and reliability were also analysed. A total of 60 children, 6 to 11 years old, participated in this study, and performed the handgrip strength test with their elbow extended and flexed at 90 degrees. Results: While using the TKK dynamometer, grip strength was significantly higher when the test was performed with elbow extended, in contrast to those obtained with elbow flexed (14.58 +/- 3.04 kg vs 12.97 +/- 2.99 kg, p<0.001 for right, and 14.25 +/- 3.05 kg vs 12.61 +/- 2.99 kg, p<0.001 for left hand). Likewise, when using the DynX dynamometer, the difference between the two elbow positions was smaller but still significant (13.84 +/- 3.22 kg vs 13.35 +/- 3.01 kg, p=0.035 for right, and 13.35 +/- 2.95 kg vs 12.77 +/- 2.96 kg, p=0.003 for left hand). Conclusions: Both dynamometers provided sufficient results in terms of their reliability and the TKK dynamometer showed to be more valid. Performing the handgrip strength test with elbow extended appears to be the most appropriate position in order to obtain maximal results in children

COMPETITIVE BOUT MODEL AS A TOOL FOR ESTIMATION OF FEMALE KARATEKA SPECIFIC ENDURANCE

The aim of this study was to establish the functional state of female karate practitioners during a Shotokan kumite competition by measuring changes in their lactate concentration and also by designing a training exercise model, that matches the workload during competitions. Seven female karate practitioners, between the ages of 18 and 30, took part in this research, which was conducted in two stages: 1) in competitive conditions during the National Shotokan Karate Championship, where capillary blood lactate concentration was measured both after the warm-up and after each bout; 2) in training conditions, where again the blood lactate concentration was determined post warm-up and after performance of the karate kumite model, which consisted of a series of techniques designed to simulate competitive kumite, and in addition to this the heart rate was recorded continuously using a heart-rate telemetry system. According to the results from the maximal aerobic test, the training level of the female karatekas tested was comparable to that of internationally ranked competitors from other countries. The lactate concentrations measured during the competition were a more reliable predictor of the competitive ranking in comparison to VO2max. The designed karate kumite training model simulated well the level of competitive load based on a comparison of the measured lactate concentrations and those determined during the competition. In all the women tested, the heart rate measured after the simulated kumite was close to the maximal values (about 180 bpm), and thus did not adequately reflect the work intensity. In conclusion, since lactate concentration accurately reflects competitive output, and correlates with the exercise intensity during a designed training model, it could be used for evaluation of the physical load and specific endurance, particularly of female karate practitioners.  Article visualizations

A NEW APPROACH TO INTERPRETATION OF SALIVARY ALFA AMYLASE ACTIVITY CHANGES AS A STRESS INDICATOR

Contemporary sport induces a serious physical and mental stress in athletes. This could result in lowering of their sports performance. Thus, the evaluation of stress in athletes is an important milestone in their preparation. Establishing levels of stress would allow targeted work by coaches and sports specialists to increase the resistance of competitors to stress. In this regard, the use of non-invasive methods for stress testing is essential. Recently, the use of saliva as a biological research material becomes of increasing interest. The aim of this study was to establish the potential of alpha amylase activity, protein and potassium concentrations in saliva to reflect adequately the degree of stress in athletes. Eleven boxers, participants in the National Championship, took part in the study. Saliva was collected by salivetes three times: 1) one week before the competition, 2) before the draw of lot, and 3) before the first bout. The salivary alpha amylase activity (sAA), protein and potassium concentrations were detected with commercially available kits. The sAA, protein and K+ concentrations rose significantly in stress conditions. The individual values of sAA showed large differences that could be explained by the poly-allelic expression of sAA whose activity depends on the number of alleles (2 to 14) with each individual. All tested indices could serve as indicators for evaluation of stress level in athletes as a high correlation between the protein and K+ and sAA values was found. In order to evaluate the changes in sAA and to compare the individual results be-tween athletes we suggested the sAA to be presented in relative units. The activities, measured in calm conditions long time before a competition could be assumed as a baseline and the coefficient of increase in sAA in a stressful condition could be accepted as a “stress coefficient”

THE LOW SERUM FERRITIN AS AN INDICATOR OF INADEQUATE NUTRITION IN INTERNATIONAL-LEVEL FEMALE SWIMMER

Introduction: Iron deficiency is a common feature in athletes, and optimizing iron levels may become a contributing factor to improved athletic performance. Purpose: This study aimed to evaluate body iron stores and their relationship with sports performance. It also sought correlations between the swimmers’ hematological, hormonal, anthropometric, and functional status and their sports achievements. Methodology: The research involved 19 athletes (11 women and 8 men) from the Bulgarian national swimming team. They were tested for maximal aerobic capacity on a cycle ergometer and had blood samples taken to determine iron status and hematological and hormonal markers. Their swimming achievements (Swimming points) were evaluated as a percentage of the world records in the respective discipline. Results: There were statistically significant differences between the female and male swimmers for Unbound Iron Binding Capacity (UIBC) and ferritin. A higher UIBC in women indicated lower iron levels in them. Among female swimmers, five had ferritin levels below 40 ng/mL. In women, a highly reliable correlation between the Swimming points and ferritin concentration (r = .68) was observed. All male swimmers had ferritin values above 40 ng/mL, and there was no reliable correlation between ferritin concentration and Swimming points, probably because ferritin was in the optimal range and is no longer a significant performance factor. Conclusions: In swimmers, the optimal serum ferritin concentration is probably in the range of 40–90 ng/mL. Many female swimmers have a relative iron deficiency with sub-optimal ferritin values. In competitive female swimmers, low ferritin level is an indicator of both iron deficiency and inadequate diet. It can be expected that an adequate nutritional regime in athletes with low ferritin values will lead both to the replenishment of iron stores and to an increase in muscle mass and, ultimately, to an improvement in sports performance

Haberlea rhodopensis alcohol extract normalizes stress-responsive transcription of the human TP53 gene

The Orpheus flower Haberlea rhodopensis (Friv.) of the family Gesneriaceae can go into anabiosis for long periods in an almost entirely desiccated state. It is an endemic relict from the Balkan Peninsula. Alcohol extracts from H. rhodopensis contain many biologically active substances with potent antioxidant, antigenotoxic, radioprotective, revitalizing and antiaging capabilities. However, regulating the gene networks responsible for these activities is vastly unknown. This study explores the cellular mechanisms underlying the protective effect of H. rhodopensis extracts (HRE). HeLa cells (human cervix epithelial carcinoma, HeLa ATCC® CCL-2™) were used as a model. We examined the changes in catalase activity and TP53 mRNA level shortly after oxidative (H2O2) and ionizing radiation (IR) induced stress with and without pre-incubation with HRE extracts. The dynamics in the activity of catalase, a main cellular antioxidant enzyme, and the expression of the stress-responsive gene TP53 were investigated by UV spectrophotometric assay and RT-qPCR, respectively. Under the applied stress conditions, H2O2 treatment and gamma radiation, catalase activity increased. This was a sign of induced ROS generation. In the first hours after treatment, the two stressors led to opposite changes in the levels of TP53 gene expression, which were alleviated by pre-incubation with HRE in a concentration-dependent manner. The broad biological activities of the studied extract, taking into account our results, show that ability of HRE to reduce the effect of stress is achieved through complex molecular mechanisms aimed at preserving cellular homeostasis. Mechanisms include the normalization of antioxidant enzyme activity such as catalase and the activity of TP53, one of the genes responsive to stress, by up or down-regulation

FUNCTIONAL CHARACTERISTICS OF SPECIALIZED CIRCUIT TRAINING FOR KARATE COMPETITORS

Successful performance in the Kumite discipline of Karate-do requires well developed aerobic and anaerobic cell-systems for supplying energy. Therefore, more and more often over the recent years, the preparation of martial arts athletes has included intensive interval training sessions following the Tabata method. The objective of this survey was to create a highly-intensive Tabata-based circuit training that is suitable for the functional preparation of Karate competitors and for defining the physiological and the biochemical characteristics of the training load through measuring the heart rate and the con-centration of lactate in the peripheral blood. A group of six Karate practitioners, all Kumite competitors, took part in the survey. They performed tree times 10 exercises with Karate-technique elements following the classical Tabata scheme of 20 seconds work with a maximum number of repetitions and 10 seconds of break. The results proved that; 1) The heart rate increased after each circuit and exceeded 180 bpm, and in the break time it went down to 120-140 bpm; 2) The lactate concentration in the blood rose progressively after the first two circuits, and after finishing the last circle an overall decrease was registered regarding this indicator (9.3 ± 3.32 vs 13.4 ± 2.39 vs 11.8 ±1.63 mmol/L, respectively). In conclusion, the intensity of the latter circuit training model is very high because the levels of blood lactate after performing each circuit of the training were higher than the respective concentrations after Kumite competition matches at the same heart rates

NUTRITIONAL STATUS AND BODY COMPOSITION OF YOUNG ARTISTIC GYMNASTS FROM BULGARIA

Young gymnasts should not have excessive body mass because that might lead to under-performance. Therefore, children practicing gymnastics should consume a balanced diet, which will promote their physical abilities and optimal body mass. The aim of this study was to compare the nutrient intake of young Bulgarian artistic gymnasts to matched groups from the National Nutrition Survey in Bulgaria (NNSB2003). The study consisted of 76 artistic gymnasts (5 to 14 years of age) from four cities in Bulgaria, and the participants were divided into three groups in accordance with the age and gender categories applied in the NNSB2003. Anthropometric measurements were taken and a food frequency questionnaire was applied in order to assess the body composition and nutrient intake of the gymnasts. The percentile scores in the height and %Fat of the gymnasts were significantly lower than the 50th percentile of the international norms. The energy intake of the gymnasts did not differ significantly from those reported in the NNSB2003, whilst the protein intake, relative protein intake, and energy contribution of proteins were significantly higher than those in the same survey. The energy contribution of fats was above the recommended norms (15-30%), as provided by the WHO. The fat intake was slightly higher, and the carbohydrate intake was slightly lower than the recommended values in the literature, and, therefore, the former should be reduced and the latter increased in their food