The aim of this study was to describe qualitatively and quantitatively dietary supplements (DS) and medication use in elite athletes. Athletes (n=912; age 23.9 ± 6 years; 72% male) reported medications and DSs taken within 3 days before doping control. We analyzed data collected from 2006 to 2008, identified and classified substances. Total of 74.6% athletes reported use of at least one substance, 61.2% took DS (3.17 per user) and 40.6% took medications. Among users, 21.2% reported the use of six and more different products, and one took 17 different products at the same time. Majority of medication users took non-steroidal anti-inflammatory drugs (NSAID) (24.7%), and 22.2% used more than one NSAID. We found no gender differences in DS use (P=0.83). Individual sport athletes used more DS (P<0.01). Our study showed widespread use of DS and drugs by elite athletes. Consumption of DS with no evident performance or health benefits, demonstrated the need for specific educational programs focused on DS use. Amount, quantity and combination of the reported products raised concern about the risk of potential side effects.

An observation study in mice suggesting that the chromatin of macula densa cells undergoes loss of structural complexity that is most pronounced immediately after birth and remains during the first month of postnatal life. The findings add to the knowledge about the changes that take place in the kidney during postnatal development function and tissue structural organization, which are linked to changes in physiological function. ABSTRACT:Aim: To determine whether complexity of chromatin structure in kidney macula densa cells (MDC) decreases during postnatal development in mice.Methods: The levels of chromatin structural complexity were measured by determining fractal dimension of MDC nuclei. Kidney tissue was obtained from the total of 32 male Swiss albino mice divided into four age groups (n = 8): newborn (0 days), 10 days old, 20 days old and 30 days old. For a total of 640 MDC chromatin structures, fractal dimension, lacunarity, as well as parameters of Grey level co-occurrence matrix (GLCM) texture were determined.Results: Chromatin fractal dimension in animals aged 10 days, 20 days and 30 days was significantly lower (P < 0.05, P < 0.01 and P < 0.001, respectively), compared with newborn mice. This complexity reduction of chromatin architecture is in accordance with previously published studies, which detected generalized and sustained loss of both tissue and cell complexity during aging. The loss of complexity was texture-independent, since there was no statistically significant difference (P > 0.05) in both chromatin angular second moment and inverse difference moment between the age groups. Conclusion:Our results indicate that age-related nuclear intrinsic factors which do not influence chromatin texture may have an important role in MDC postnatal development.

There is compelling evidence that postexercise heart rate recovery (HRR) is a valid indicator of sympaticovagal balance. It is also used in prescription and monitoring of athletic training. The purpose of our study was to determine HRR after maximal exercise among elite athletes with respect to age. A total of 274 elite male Caucasian athletes were randomly selected from the larger sample and divided into two groups: adolescent (group Y) and adult athletes (≥18 years; group A). They performed maximal cardiopulmonary exercise testing on a treadmill. Heart rate recovery was calculated as the rate of decline of HR from peak exercise to rates 1, 2 and 3 min after cessation of exercise (HRR1, HRR2 and HRR3). A significantly higher HRR1 was found in group A (29·5 ± 15·6 versus 22·4 ± 10·8, P<0·001), but HRR3 was higher in group Y (82·7 ± 10·2 versus 79·9 ± 12·25; P = 0·04). Stepwise multivariate linear regression analysis showed that, among all subjects, the HRR1 alone was independently associated with age (P<0·001). The maximal oxygen consumption (VO max) was in a negative relationship with HRR1 and in a positive one with HRR3 (P<0·05) with respect to all athletes. The HRR during 3 min postexercise should be reported for the purpose of better assessing functional adaptation to exercise among elite athletes as well as the age-associated differences in recovery. Higher values of HRR1 should be expected in older athletes, and HRR3 could be used as an index of aerobic capacity, irrespective of age.

No abstract

Summary Recent studies have suggested that silver nanoparticles (AgNPs) may affect cell DNA structure in in vitro conditions. In this paper, we present the results indicating that AgNPs change nuclear complexity properties in isolated human epithelial buccal cells in a time‐dependent manner. Epithelial buccal cells were plated in special tissue culture chamber / slides and were kept at 37°C in an RPMI 1640 cell culture medium supplemented with L‐glutamine. The cells were treated with colloidal silver nanoparticles suspended in RPMI 1640 medium at the concentration 15 mg L−1. Digital micrographs of the cell nuclei in a sample of 30 cells were created at five different time steps: before the treatment (controls), immediately after the treatment, as well as 15 , 30 and 60 min after the treatment with AgNPs. For each nuclear structure, values of fractal dimension, lacunarity, circularity, as well as parameters of grey level co‐occurrence matrix (GLCM) texture, were determined. The results indicate time‐dependent reduction of structural complexity in the cell nuclei after the contact with AgNPs. These findings further suggest that AgNPs, at concentrations present in today's over‐the‐counter drug products, might have significant effects on the cell genetic material.

We present here the improved design and development of optical sensor for non-invasive measurements of arterial blood flow waveform. The sensor is based on a physical principle of reflective photoplethysmography (PPG). As the light source we used serially connected infrared diodes whereas NPN silicon phototransistors were used as light detectors. The electronic components were molded into square package and poured with silicone. Such preparation produced an elastic superficies that allowed excellent attachment of the sensor on the skin's surface. Moreover, a serial connection of infrared diodes and phototransistors completely eliminated signal artifacts caused by minor muscle contractions. The sensor recording performances were examined at the photoplethysmographic sites on three different arteries; the commune carotid, femoral and radial and, on each site the sensor demonstrated remarkable capability to make a consistent, reproducible measurements. Because of the advantageous physical and electrical properties, the new sensor is suitable for various cardiovascular diagnostics procedures, especially when long-term measurements of arterial blood flow waveform are required, for monitoring of different parameters in cardiovascular units and for research.

Determination of the heart rate recovery (HRR) after the session of a physical activity, represents the valuable parameter for the investigation of autonomic balance and its dynamic in the general population, but also in the population of elite athletes. However, the methodology for its determination and analysis is still not entirely specified. It is necessary to define an adequate protocol of cardiopulmonary exercise test, by choosing an adequate ergometer (treadmill, ergo-bicycle or step bench). Organization of recovery period (active or passive), after the session of exercise is also very important, because its protocol interfered significantly with the value of HRR. Interpretation of obtained HRR values varies a lot, and researcher has freedom to choose the most adequate way, in accordance with the objectives of his study. Following paper represents a short review of determination, interpretation and analysis of HRR, followed by the latest recommendations.Key words: heart rate recovery, cardiopulmonary exercise test, maximal oxygen uptake, autonomic balance SažetakPraćenje oporavka srčane frekvencije nakon sesije fizičke aktivnosti (engl. heart rate recovery, HRR) predstavlja veoma značajan parametar koji možemo koristiti u cilju izučavanja balansa autonomnog nervnog sistema, kako u opštoj populaciji, tako i u populaciji vrhunskih sportista. Metodologija koja se koristi za određivanje i analizu HRR, međutim, još uvek nije adekvatno definisana. Prvenstveno je potrebno definisati adekvatan protokol testa opterećenja koji koristimo u svrhu određivanja HRR, a zatim i odabrati odgovarajući ergometar (tredmil, ergo -bicikl ili step -klupica). Potrebno je definisati i protokol perioda oporavka (da li će oporavak biti aktivan ili pasivan), budući da odabrani protokol značajno utiče na dobijene vrednosti HRR. Interpretacija dobijenih vrednosti HRR veoma varira od studije do studije, tako da istraživači imaju slobodu da izaberu način interpretacije koji najviše odgovara potrebama specifičnog istraživanja. Uzevši u obzir gore navedene činjenice, naš rad predstavlja jedan kratak pregled protokola koje možemo koristiti u određivanju, interpretaciji i analizi vrednosti HRR, prateći najnovije preporuke. Ključne reči: oporavak srčane frekvencije, test fizičkog opterećenja, maksimalna potrošnja kiseonika, balans autonomnog nervnog sistema

SažetakUvod: Kao jedna od prednosti redovne fizičke aktivnosti navodi se niža srčana frekvencija u miru i njen brži oporavak nakon testa maksimalnog opterećenja, kao posledica jačeg parasimpatičkog (vagusnog) tonusa. Oporavak srčane frekvencije se koristi kao pouzdan parametar fizičke utreniranosti, ali i u prognostičke svrhe kao parametar rizika za obolevanje od kardiovaskularnih bolesti. Cilj: Cilj ove studije je da pokaže postojanje statistički značajnih razlika u oporavku srčanih frekvencija nakon maksimalnog opterećenja i razlike frekvencija u mirovanju između različitih grupa vrhunskih sportista. Materijal i metode: Ovom studijom je obuhvaćeno 575 odraslih (23,1 ± 4,3 godina) sportista muškog pola, podeljenih u četiri grupe sportova: sportove veštine, snage, mešovitih disciplina i izdržljivosti. Svi ispitanici su izveli maksimalni, progresivni kardiopulmonalni test fizičkim opterećenjem na traci za trčanje. Oporavak srčane frekvencije u prvom (ΔHRR1) i trećem minutu (ΔHRR3) definisan je razlikom maksimalne srčane frekvencije i frekvencije u prvom, odnosno trećem minutu po okončanju vežbanja. Rezultati: Statistički značajno niže vrednosti srčane frekvencije u mirovanju zabeležene su u grupi izdržljivosti (56,2 ± 10,6 min -1 ) u odnosu na grupe sportova veština, snage i mešovitih disciplina (62,9 ± 11,4; 61,5 ± 10,0; 59,9 ± 10,4 min ) u odnosu na grupe sportova veštine, snage i mešovitih disciplina (24,3 ± 10,9; 25,5 ± 11,2; 27,8 ± 15,6 min -1 ) (p = 0,05). Vrednosti ΔHRR3 su bile značajno više u grupi snage, mešovi-tih disciplina i izdržljivosti (74,8 ± 14,3; 79,5 ± 12,7; 79,4 ± 12,6 min -1 ) u odnosu na grupu veština (67,3 ± 16,1 min -1 ) (p = 0,05). Zaključak: Treniranje sportova iz grupe izdržljivosti najviše doprinosi smanjenju srčane frekvencije u mirovanju i brzini njenog oporavka u prvom minutu nakon vežbanja zbog preovlađujućeg parasimpatičkog tonusa. Ključne reči: srčana frekvencija, oporavak, trening, sportisti Abstract Introduction: One of the benefits of regular physical activity is lower resting heart rate and its faster recovery after maximal exercise test, as a result of a stronger parasympatic (vagal) tone. Heart rate recovery is used as reliable parameter for prescription of the training program and also in prognostic purposes as a parameter of risk for developing cardiovascular diseases. Aim: The purpose of this study is to show significant differences in heart rate recovery after maximal exercise test and resting heart rate among different groups of elite athletes. Material and Methods: This study subjected 575 adult (23.1 ± 4.3 years), male athletes divided into four sport groups: skill, power, mixed and endurance. Every subject performed progressive, maximal cardiopulmonary exercise test on a treadmill. Heart rate recovery in first (ΔHRR1) and third (ΔHRR3) minute was calculated as a difference of maximal heart rate and heart rate in the first and the third minute after cessation of exercise, respectively. Results: Compared to skill, power and mixed group (62.9 ± 11.4; 61.5 ±...