BACKGROUND: Low levels of vitamin D have been associated with several autoimmune diseases. A growing body of evidence supports the association of vitamin D with skeletal muscle damage, regeneration, and energy and lipid metabolism. The aim was to analyse vitamin D and its receptor (VDR) in the muscle tissue of patients with idiopathic inflammatory myopathies (IIM) and to relate them to clinical parameters and muscle lipid and energy metabolism. METHODS: Forty-six patients with IIM and 67 healthy controls (HC) were included in the study. 27 IIM patients participated in a 24-week exercise intervention. Muscle biopsies were obtained from 7 IIM patients before/after training, 13 non-exercising IIM controls, and 21 HC. Circulating concentrations of 25(OH)D and 1,25(OH)D were measured. Gene expression of VDR and CYP27B1, the enzyme converting 25(OH)D to hormonally active 1,25(OH)D, was determined by qPCR in muscle tissue and primary muscle cells. Lipid oxidative metabolism was assessed in muscle tissue (mRNA, qPCR) and primary muscle cells (radioactive assays). RESULTS: Lower levels of active 1,25(OH)D were observed in IIM patients compared with HC (mean ± SD: 125.0 ± 45.4 vs. 164.7 ± 49.2 pmol/L; p < 0.0001). 25(OH)D was associated with CRP (r = -0.316, p = 0.037), MITAX (r = -0.311, p = 0.040) and HAQ (r = -0.390, p = 0.009) in IIM. After 24 weeks of training, active 1,25(OH)D was associated with MMT8 (r = 0.866, p < 0.0001), FI-2 (r = 0.608, p = 0.013) and HAQ (r = -0.537, p = 0.032). Gene expression of both VDR and CYP27B1 in primary muscle cells decreased after training (p = 0.031 and p = 0.078, respectively). Associations of VDR mRNA in muscle tissue with MMT-8 (IIM: r = -0.559, p = 0.013), serum CK (HC: r = 0.484, p = 0.031), myoglobin (IIM: r = 0.510, p = 0.026) and myostatin (IIM: r = -0.519, p = 0.023) were observed. The expression of VDR in differentiated muscle cells correlated negatively with the complete oxidation of palmitic acid (r = -0.532, p = 0.028). Muscle mRNA of carnitine palmitoyl transferase 1 (CPT1) (downregulated in IIM, p = 0.001) correlated positively with serum 1,25(OH) vitamin D (r = 0.410, p = 0.042). CONCLUSION: Reduced biologically active vitamin D in circulation suggests its impaired metabolism in IIM. Serum vitamin D levels and gene expression of its receptor and activating enzyme in muscle tissue were modified by regular exercise and associated with disease manifestations, physical fitness, and muscle lipid metabolism of IIM patients.
- MeSH
- 1-alfa-hydroxylasa 25-hydroxyvitaminu D3 metabolismus MeSH
- dospělí MeSH
- kosterní svaly * metabolismus MeSH
- lidé středního věku MeSH
- lidé MeSH
- metabolismus lipidů * fyziologie MeSH
- myozitida * metabolismus MeSH
- receptory kalcitriolu * metabolismus MeSH
- senioři MeSH
- tělesná výkonnost * fyziologie MeSH
- vitamin D * krev metabolismus MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
OBJECTIVES: Idiopathic inflammatory myopathies/IIM are associated with changes in muscle-specific microRNA/miR. Exercise improves muscle function and metabolism in parallel with changes in miR expression. We investigated the effects of disease and exercise on miRs in differentiated muscle cells/myotubes from IIM patients and controls. METHODS: Samples of m. vastus lateralis were obtained by needle biopsy from IIM patients before/after 6-month training and from matched sedentary healthy controls. Muscle cell cultures were established and exposed to saturated fatty acid during differentiation. MiR-133a,-133b,-206,-1 and their target genes (qPCR), fat oxidation (FOx), lipids (chromatography) and mitochondrial oxidative phosphorylation (OxPHOS) complexes (immunoblotting) were measured. Interrelations between in vitro miRs and metabolism of myotubes as well as clinical parameters and disease activity/MITAX were explored. RESULTS: Levels of miRs were higher in myotubes derived from IIM patients compared to healthy controls (up to 3.5-fold, p<0.05). Neither 6-month training (IIM patients) nor in vitro palmitate treatment modulated myomiRs in myotubes. However, miR-133a,-133b, and miR-1 correlated negatively with FOx (p<0.01), triacylglycerols (p<0.05) and OxPHOS complex-V (p<0.05) and positively with OxPHOS complex-I (p<0.05) in myotubes. MiR-133a and miR-133b in myotubes were related to disease activity and fasting glycaemia in vivo (both p<0.05). CONCLUSIONS: Upregulation of microRNAs involved in myogenesis and regeneration in muscle cells derived from IIM patients indicates activation of compensatory epigenetic mechanisms, potentially aimed to counteract disease progression. Relationships of microRNAs with in vitro metabolic profile of muscle cells as well as with clinical parameters support the role of muscle-specific microRNAs in modulating muscle metabolism and clinical state of patients.
- MeSH
- cvičení fyziologie MeSH
- kosterní svalová vlákna metabolismus patologie MeSH
- kosterní svaly fyziologie MeSH
- kultivované buňky MeSH
- lidé MeSH
- mikro RNA * genetika metabolismus MeSH
- myozitida * patologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Red-backed shrikes (Lanius collurio) behave quite differently towards two common nest predators. While the European jay (Garrulus glandarius) is commonly attacked, in the presence of the Eurasian magpie (Pica pica), shrikes stay fully passive. We tested the hypotheses that this passive response to the magpie is an alternative defense strategy. Nesting shrikes were exposed to the commonly attacked European kestrel (Falco tinnunculus) in a situation in which i) a harmless domestic pigeon, ii) a commonly attacked European jay, and iii) a non-attacked black-billed magpie are (separately) presented nearby. The kestrel dummy presented together with the magpie dummy was attacked with a significantly lower intensity than when it was presented with the other intruders (pigeon, jay) or alone. This means that the presence of the magpie inhibited the shrike's defense response towards the other intruder. These results support our previous hypotheses that shrikes use an alternative defense strategy in the magpie's presence. We hypothesize that the magpie is able to associate the active defense of the shrikes with the close proximity of a nest and that shrikes try not to draw the magpie's attention to the nest. The reason why this strategy is not used against the jay remains unanswered as jays as well as magpies show very similar cognitive and foraging skills enabling them to individuate the nest presence according to active parental defense.
- MeSH
- hnízdění * MeSH
- predátorské chování * MeSH
- ptáci * MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
OBJECTIVE: The aim of the study was to evaluate the influence of Er:YAG laser irradiation on the debonding of metal and ceramic brackets and enamel damage ex vivo. BACKGROUND DATA: The principle of safe bracket debonding is to degrade the adhesive resin strength connecting the tooth and bracket. Removal of adhesive resin from tooth surfaces without iatrogenic damage (enamel loss) is generally the main problem of the otherwise very successful method of aesthetic straightening of teeth. METHODS: Forty ceramic and metal brackets (Clarity™ Advanced and Victory Series™; 3M Unitek, Monrovia, CA) were standardly bonded to buccal polished enamel surfaces of 30 caries-free human third molars. Two types of adhesive resins (Transbond™ XT Light Cure Adhesive; 3M Unitek, and Variolink II Professional Set; Ivoclar Vivadent AG) were used. Before debonding, the brackets in the laser group were irradiated with the Er:YAG laser (FJFI CVUT) 280 mJ, 250 μs long, repetition rate 6 Hz, spot focus 1 mm, and 140 sec. The control group was debonded without the laser irradiation. During the bracket irradiation, temperature changes inside the tooth were monitored using a thermal image infrared camera. The enamel surface was investigated by SEM. RESULTS: It has been observed that bracket removal was easier after the Er:YAG laser irradiation, and temperature rise was limited (from 2.0°C to 3.2°C) also for metal brackets. As against the nonirradiated samples, SEM investigation has confirmed no damage to enamel. CONCLUSIONS: Irradiation with Er:YAG laser radiation before debonding of ceramic brackets significantly decreases the bonding failure and amount of remaining adhesive.
- MeSH
- dospělí MeSH
- lasery pevnolátkové * MeSH
- lidé MeSH
- mikroskopie elektronová rastrovací MeSH
- mladiství MeSH
- molár třetí MeSH
- ortodontické zámky * MeSH
- povrchové vlastnosti MeSH
- techniky in vitro MeSH
- testování materiálů MeSH
- zubní lepené konstrukce - odstranění přístrojové vybavení MeSH
- zubní sklovina zranění účinky záření MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- mladiství MeSH
- Publikační typ
- časopisecké články MeSH
We compared the responses of the nesting red-backed shrikes (Lanius collurio) to three dummies of a common nest predator, the Eurasian jay (Garrulus glandarius), each made from a different material (stuffed, plush, and silicone). The shrikes performed defensive behaviour including attacks on all three dummies. Nevertheless, the number of attacks significantly decreased from the stuffed dummy through the plush dummy and finally to the silicone dummy. Our results show that wild birds use not only colours but also other surface features as important cues for recognition and categorization of other bird species. Moreover, the silicone dummy was attacked only when presented after the stuffed or plush dummy. Thus, we concluded that the shrikes recognized the jay only the stuffed (with feathered surface) and plush (with hairy surface) dummies during the first encounter. Recognition of the silicon dummy (with glossy surface) was facilitated by previous encounters with the more accurate model. This process resembles the effect of perceptual priming, which is widely described in the literature on humans.
Úvod a cíl: Cílem studie bylo srovnat účinek laserové ablace v kontaktním a nekontaktním módu a zjistit, jaký vliv mají oba typy preparace na vazbu s ultrazvukově vrstveným materiálem, tedy především jaká je jeho modelovatelnost a jaká vzniká chemická i mechanická vazba u takovéto výplně. Metody: Parametry erbiového laseru pro kontaktní preparaci byly 250 mJ/pulz, opakovací frekvence 15 Hz, výkon 3,75 W. Pro bezkontaktní laserovou ablaci byly použity následující hodnoty: 600 mJ/pulz, 6 Hz, 3,6 W. Struktura skloviny a dentinu po laserové preparaci byla analyzována v rastrovacím elektronovém mikroskopu. Kavity byly vyplněny ultrazvukem aktivovaným kompozitním materiálem. Chemická a mechanická vazba byla pozorována rastrovacím elektronovým mikroskopem. Penetrační spára byla hodnocena kvantitativně stupněm penetrace barviva metylenové modři. Fischerův exaktní test (p < 0,05) byl použit pro statistické vyhodnocení výsledků. Výsledky: Kontaktní i nekontaktní mód vytváří dobře ohraničené kavity s jasně určeným rozhraním mezi sklovinou, dentinem a kompozitem v rozsahu 5167,31 μm versus 5356,31 μm. V řezech nejsou vidět defekty, ultrazvuková koncovka dobře navrství výplň do kavity. Penetrační spáry viditelné po průniku metylenové modři se pohybují v rozsahu 481,19 μm versus 611,94 μm. Rozdíl mezi oběma technikami není statisticky významný. Závěr: Kavity preparované laserem v kontaktním módu vyplněné ultrazvukem aktivovaným kompozitním materiálem chrání výplň před vznikem penetrační spáry.
Introduction: The comparison of tissue quality and its restoration after contact, and non-contact Er: YAG (2940 nm) laser radiation ablation was evaluated. Methods: Laser setting for contact ablation was 250 mJ/pulse, pulse repetition rate 15 Hz, average power 3.75 W. For non-contact ablation these values were: 600 mJ/pulse, 6 Hz, 3.6 W. Structure of enamel and dentin after laser ablation was analyzed in scanning electron microscope. All cavities were filled by sonic-activated composite resin. Chemical and mechanical bond was observed in scanning electron microscope. Microleakage was assessed quantitatively by the degree of methylene blue dye penetration. Fischer exact test (p < 0.05) was used for statistical evaluation. Results: Contact and non-contact laser treatments prepared similar cavities (5167.31 μm versus 5356.31 μm). Defocusing of non-contact therapy has direct influence on the dye penetration microleakage presence (481.19 μm versus 611.94 μm) but this increase was not statistical significant. Conclusion: Cavity prepared by contact mode with sonic-activated composite filling protects microleakage formation.
- MeSH
- dentinová adheziva MeSH
- laserová terapie * metody přístrojové vybavení MeSH
- lasery pevnolátkové * využití MeSH
- lidé MeSH
- molár třetí MeSH
- preparace zubní kavity * metody MeSH
- složené pryskyřice MeSH
- trvalá zubní náhrada MeSH
- výzkum MeSH
- zubní nástroje MeSH
- zubní sklovina MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- práce podpořená grantem MeSH
