Objectives: The relationship between the isokinetic maximal strength of internal or external shoulder rotation and serve speed in tennis is well established, yet the influence of segmental mass, height, and high-speed shoulder rotation strength on serve performance in junior players remains unclear. This study aimed to investigate the relationship between concentric or eccentric isokinetic shoulder strength, segmental mass, height, and first-serve speed aimed at the T-target zone. Methods: Fifteen male junior competitive tennis players (mean ± SD: age 15.9 ± 0.9 years; height: 180.1 ± 7.2 cm; body mass: 66.1 ± 5.7 kg) were assessed for maximal isokinetic strength during concentric and eccentric internal and external shoulder rotations. Segmental mass (arm, leg, and trunk) was measured using dual-energy X-ray absorptiometry, and serve speed was recorded using a radar gun. Results: Concentric shoulder rotations at 210°/s demonstrated significant positive correlations with serve speed for both external (ρ = 0.71, p ≤ 0.01) and internal rotation (ρ = 0.61, p ≤ 0.05). Although lean arm mass partially mediated the relationship between shoulder strength and serve speed (indirect effect = 0.502, 95% CI: -0.156 to 1.145), this mediation effect was not statistically significant. Height was moderately correlated with serve speed (ρ = 0.68, p ≤ 0.01) but did not moderate the relationship between shoulder strength and serve speed. Conclusions: Concentric shoulder strength at higher angular velocities and segmental mass contribute to serve speed in junior tennis players. While height provides structural advantages, strength and lean mass play important roles, emphasizing the need for targeted training programs.

• Publication type
• Journal Article MeSH

Úvod: Dutina ústní představuje komplexní systém, kde probíhá vzájemná chemická komunikace mezi tkáněmi, mikrobiotou a složkami sliny a potravy. Tento článek je zaměřen na hormetické efekty a elektrofilní sloučeniny, které mohou hrát roli v obranných mechanismech proti oxidačnímu stresu a zánětlivým procesům. Hormetické efekty, vyvolané subletálními nebo subtoxickými stresory, mohou aktivovat reparační mechanismy a posílit odolnost tkání proti poškození. Metodika: Analýza byla provedena prostřednictvím vyhledávání ve třech elektronických databázích: Web of Science, PubMed a Scopus. V rámci rešerše jsme se soustředili na studie publikované mezi lety 2000 a 2023, které se zabývaly oxidačně-redukčními procesy, zánětlivými stavy a aktivací Nrf2 dráhy v ústní dutině. Vyloučeny byly studie zaměřené na nádorová onemocnění. Závěr: Elektrofilní sloučeniny působí jako jeden z činitelů zasahujících do homeostázy dutiny ústní a mohou tak představovat terapeutický potenciál v zubním lékařství, konkrétně v parodontologii. Zjištění založená na in vitro a preklinických studiích však vyžadují další ověření v klinických podmínkách, přičemž je třeba zvážit i interakce s orální mikrobiotou.

Introduction: The oral cavity is a complex system in which mutual chemical communication occurs between tissues, microbiota, and components of saliva and food. This paper focuses on hormetic effects and electrophilic compounds, which can play a role in defense mechanisms against oxidative stress and inflammatory processes. Hormetic effects, induced by sublethal or subtoxic stressors, can activate repair mechanisms and enhance tissue resistance to damage. Methods: The analysis was conducted through searches in three electronic databases: Web of Science, PubMed, and Scopus. Our research focused on studies published between 2000 and 2023 that dealt with redox processes, inflammatory conditions, and activation of the Nrf2 pathway in the oral cavity. Studies focused on cancerous diseases were excluded. Conclusion: Electrophilic compounds act as one of the agents that interfere with the homeostasis of the oral cavity, and can thus find therapeutic potential in dentistry, specifically in periodontology. However, findings based on in vitro and preclinical studies require further verification under clinical conditions, and also considering interactions with oral microbiota.

• MeSH
• Antioxidant Response Elements * physiology   MeSH
• Stress, Physiological MeSH
• Homeostasis physiology   MeSH
• Hormesis physiology   MeSH
• Humans MeSH
• Metabolic Networks and Pathways MeSH
• Oxidation-Reduction MeSH
• Mouth * physiology   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Systematic Review MeSH

Electrochemical methods can be used not only for the sensitive analysis of proteins but also for deeper research into their structure, transport functions (transfer of electrons and protons), and sensing their interactions with soft and solid surfaces. Last but not least, electrochemical tools are useful for investigating the effect of an electric field on protein structure, the direct application of electrochemical methods for controlling protein function, or the micromanipulation of supramolecular protein structures. There are many experimental arrangements (modalities), from the classic configuration that works with an electrochemical cell to miniaturized electrochemical sensors and microchip platforms. The support of computational chemistry methods which appropriately complement the interpretation framework of experimental results is also important. This text describes recent directions in electrochemical methods for the determination of proteins and briefly summarizes available methodologies for the selective labeling of proteins using redox-active probes. Attention is also paid to the theoretical aspects of electron transport and the effect of an external electric field on the structure of selected proteins. Instead of providing a comprehensive overview, we aim to highlight areas of interest that have not been summarized recently, but, at the same time, represent current trends in the field.

• MeSH
• Electrochemical Techniques * methods   MeSH
• Electrochemistry MeSH
• Oxidation-Reduction MeSH
• Proteins * MeSH
• Electron Transport MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Review MeSH

• MeSH
• Cannabidiol * pharmacology   MeSH
• Rats MeSH
• Dronabinol * pharmacology   MeSH
• Animals MeSH
• Check Tag
• Rats MeSH
• Animals MeSH
• Publication type
• Letter MeSH

In this contribution, a comprehensive study of the redox transformation, electronic structure, stability and photoprotective properties of phytocannabinoids is presented. The non-psychotropic cannabidiol (CBD), cannabigerol (CBG), cannabinol (CBN), cannabichromene (CBC), and psychotropic tetrahydrocannabinol (THC) isomers and iso-THC were included in the study. The results show that under aqueous ambient conditions at pH 7.4, non-psychotropic cannabinoids are slight or moderate electron-donors and they are relatively stable, in the following order: CBD > CBG ≥ CBN > CBC. In contrast, psychotropic Δ9-THC degrades approximately one order of magnitude faster than CBD. The degradation (oxidation) is associated with the transformation of OH groups and changes in the double-bond system of the investigated molecules. The satisfactory stability of cannabinoids is associated with the fact that their OH groups are fully protonated at pH 7.4 (pKa is ≥ 9). The instability of CBN and CBC was accelerated after exposure to UVA radiation, with CBD (or CBG) being stable for up to 24 h. To support their topical applications, an in vitro dermatological comparative study of cytotoxic, phototoxic and UVA or UVB photoprotective effects using normal human dermal fibroblasts (NHDF) and keratinocytes (HaCaT) was done. NHDF are approx. twice as sensitive to the cannabinoids' toxicity as HaCaT. Specifically, toxicity IC50 values for CBD after 24 h of incubation are 7.1 and 12.8 μM for NHDF and HaCaT, respectively. None of the studied cannabinoids were phototoxic. Extensive testing has shown that CBD is the most effective protectant against UVA radiation of the studied cannabinoids. For UVB radiation, CBN was the most effective. The results acquired could be used for further redox biology studies on phytocannabinoids and evaluations of their mechanism of action at the molecular level. Furthermore, the UVA and UVB photoprotectivity of phytocannabinoids could also be utilized in the development of new cannabinoid-based topical preparations.

• MeSH
• Antioxidants * pharmacology   MeSH
• Cannabidiol * MeSH
• Humans MeSH
• Dronabinol MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

Publikace se zaměřuje na elektrochemickou a biochemickou analýzu molekul. Určeno odborné veřejnosti.

• MeSH
• Electrochemical Techniques MeSH
• Electrochemistry MeSH
• Clinical Chemistry Tests MeSH
• Molecular Biology MeSH
• Publication type
• Monograph MeSH

• Conspectus
• Biochemie. Molekulární biologie. Biofyzika
• NML Fields
• biochemie
• chemie, klinická chemie

Musculus piriformis je významný sval pro biomechaniku člověka. Jedná se o nejsilnější a nejodolnější zevní rotátor kyčelního kloubu, jde i o silný abduktor. Při mnoha pohybových aktivitách, včetně sportu, je výrazně zatěžován. Při řadě patologických stavů dochází k jeho reflexní dlouhodobé hyperaktivaci, a proto u mnoha osob nacházíme hypertonus a často hypertrofii a zkrácení. Vzhledem k intimnímu kontaktu k nervus ischiadicus dochází k dráždění nervových vláken. To buď jen tlakem hypertrofického svalu, nebo když nerv prochází alespoň částí svých vláken skrz sval a dochází k tahové neuropatii. Vzniká tak ischialgie , spadající do skupiny low back pain. Mezi několik klinických testů, používaných v praxi, patří i FAIR test (flexe , addukce, vnitřní rotace), který napíná sval a v případě zvýšení či vyvolání ischialgií jej hodnotíme jako pozitivní. V naší studii jsme se zaměřili na korelaci výsledků FAIR s nálezem na MRI. Náš soubor se skládal z 25 pacientů s chronickou ischialgií, 11 mužů, 14 žen. S normálním klinickým neurologickým nálezem, s vyloučením kořenové léze S1, diskopatie L5/S1, revmatologickým či infekčním onemocněním, patologií kyčelního kloubu. Po klinickém vyšetření byli pacienti vyšetřeni na MRI s projekcí na oblast m.piriformis. Z 25 vyšetřených jsme u 11 na MRI nalezli kompresi n. ischiadicus ve foramen infrapiriforme, u 4 kompresi nervu při průchodu svalem, u 4 nebyla žádná známka jakékoliv iritace nervu, u 6 byla nalezena jiná patologie. Z výsledku vyplývá, že FAIR test má vysokou senzitivitu při diagnostice iritace n. ischiadicus v oblasti foramen infrapiriforme, či při průchodu svalem. Zároveň nám ale výsledky ukázaly, že bez adekvátního zobrazení nejsme schopni odlišit funkční iritaci n. ischiadicus od dráždění jiným patologickým procesem. Proto z hlediska řádné diagnostiky nezbývá než toto vyšetření doporučit jako součást přesné diagnostiky.

Musculus piriformis is an important muscle for human biomechanics. It is the most powerful and resistant external rotator of the hip joint as well as a strong abductor. In many locomotive activities including sports it is the subject to reflex long term hyperactivation, and we therefore encounter excessive tonus (hypertonus) and often hypertrophy and shortened muscle. In view of the intimate contact with the narvus ischiadicus the nervous filaments are irritated. It is either due to the pressure of the hypertrophic muscle or the situation when the nerve passes at least partly through the muscle and a traction neuropathy develops. It results to ischialgia which belongs to the low back pain group. Several clinical tests used in practice include the FAIR text (flexion, adduction, internal rotation), which stretches the muscle and in case of increased or provoked ischialgia it is evaluated as positive. In our study we paid attention to the correlation of the FAIR results with MRI finding. Our cohort included 25 patients with chronic ischialgia, 11 men and 14 women with normal clinical neurological findings. We excluded root lesion S1, discopathy L5/S1, rheumatological or infectious disease and a pathology of the hip joint. After a clinical examination the patients were examined on the MRI projection to the area of m. piriformis. In 11 out of the 25 patients examined by NRI we found compression of n. ischiadicus (ischiadic nerve) in foramen infrapiriforme, compression the nerve in passing the muscle in four, no sign of irritation of the nerve in other four patients and other kinds of pathology in six. The results indicated high sensitivity of the GFSAIR test in diagnostics of irritation of n. ischiadicus in the region of foramen infrapiriforme or in passage through the muscle. At the same time the results revealed that without adequate imaging it is impossible to differentiate functional irritation of ischiadic nerve from an irritation by another pathological process. Therefore, from the point of view of correct diagnostics until the recommendation to make it a part of precise diagnostics.

• MeSH
• Adult MeSH
• Clinical Studies as Topic MeSH
• Middle Aged MeSH
• Humans MeSH
• Low Back Pain diagnosis   etiology   MeSH
• Magnetic Resonance Imaging methods   MeSH
• Sciatic Neuropathy diagnostic imaging   MeSH
• Sciatic Nerve diagnostic imaging   MeSH
• Aged MeSH
• Piriformis Muscle Syndrome * diagnostic imaging   diagnosis   MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Aged MeSH
• Female MeSH

Elektrochemické metody hrají významnou roli nejenom v základním fyzikálně-chemickém výzkumu, ale jsou široce využívány také pro analytické účely. Dnes nachází uplatnění ve vývoji nových čidel (senzorů) a v miniaturizované laboratorní technice pracující jak ve stacionárním, tak i průtočném režimu. Od druhé poloviny 20. století byly elektrochemické přístupy aplikovány v biochemickém a biofyzikálním výzkumu, což vedlo ke vzniku nové samostatné disciplíny bioelektrochemie.

Předkládaná skripta poskytují přehledné informace o nejdůležitějších moderních instrumentálních metodách, jejich principech a současném využití nejenom v klinické praxi, ale i v biomedicínském či farmaceutickém výzkumu. Při jejich tvorbě autoři vycházeli z konceptu laboratorní medicíny. Obsah studijního textu byl z edukačních důvodů rozdělen na preanalytickou fázi laboratorního vyšetření, na skupinu metod detekčních a skupinu metod izolačních, separačních a amplifikačních se zaměřením na analýzu v kapalinách.

The development of clinically applicable portable sensors and multiplex protein biomarker assays is one of the most important goals of laboratory medicine today. Sensing strategies based on electrochemical devices are discussed in this overview, with special emphasis on detection principles derived from voltammetry, electrogenerated chemiluminescence, bipolar electrochemistry and impedance-based measurements. Up-to-date examples of electrochemical methods in biomedical research and development are highlighted here, including critical evaluation and future directions of the analysis, development and validation of new protein biomarkers.

• MeSH
• Biomarkers analysis   MeSH
• Biosensing Techniques methods   MeSH
• Electrochemical Techniques methods   MeSH
• Humans MeSH
• Microarray Analysis methods   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH