microstructure
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Taurine, a sulphur - containing amino acid, has been termed a functional nutrient. Its synthetic form is a common ingredient in supplements and energy drinks. There is no information concerning taurine impact on bone microstructure after prolonged supplemental use. Also, differences in bone parameters of mice following taurine exposure are unknown. In this study, a detailed microstructure of compact and trabecular bone tissues of mice subchronically exposed to taurine was determined. Animals (n=12) were segregated into three groups: E1 group - mice received 20 mg/kg b.w. of taurine per day during 8 weeks; E2 group - mice were fed by taurine at a dose of 40 mg/kg b.w. for 8 weeks and a control (C) group. Decreased density of secondary osteons, increased sizes of primary osteon's vascular canals (P<0.05) were observed in taurine - treated animals. Cortical bone thickness, trabecular thickness were decreased (P<0.05) in E1 group, and relative volume of trabecular bone was lower (P<0.05) in E2 group as compared to C group. According to our results, prolonged taurine exposure at the doses used in this study can negatively affect both compact and trabecular bone tissues microstructure.
- MeSH
- femur účinky léků patologie fyziologie MeSH
- kortikální kost cytologie účinky léků fyziologie MeSH
- kostní denzita účinky léků fyziologie MeSH
- myši MeSH
- náhodné rozdělení MeSH
- rozvrh dávkování léků MeSH
- taurin aplikace a dávkování toxicita MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Patofyzioiogickým podkladem narkolepsie-kataplexie je ztráta hypokretinových neuronů posterolaterálního hypotalamu. Předpokládaným projevem tohoto deficitu je změna mikrostruktury a autonomních funkcí ve spánku u těchto pacientů. Cílem studie bylo hodnocení mikrostruktury NREM (non-rapid eye movement) spánku metodou sledování cyklických alternujících vzorců (CAP) a změny variability srdeční frekvence (HRV). Do studie bylo zahrnuto 15 pacientů s narkolepsiíkataplexií (průměrný věk 35 8,5 věkové rozmezí 22-44 let) a 15 zdravých kontrol (31 ± 11,4; 19-48 let). Obě skupiny podstoupily 2 následná polysomnografická vyšetření, pro analýzu CAP a HRV byla zpracována data ze 2. noci. Prokázali jsme signifikantní snížení CAP, provázené sníŽením LF a zvýšením HF složky při redukci poměru LF/HF v průběhu NREM spánku. Výsledky vyjadřují poruchu kolísání prahu probuzení u narkolepsie-kataplexie, která je provázena redukcí tonu sympatiku během NREM spánku. Domníváme se, narkolepsie nevzniká pouze v důsledku poruchy regulace REM spánku, nýbrž že je současně vlivem deficientní hypokretinové modulace alt porušena i regulace NREM spánku.
The present study was aimed at analysing the non-rapid eye movement (NREM) sleep microstructure by the cyclic alternating pattern (CAP) and at assessing the heart rate variability (HRV) changes in patiens with narcolepsy, hypothesizing a correlation of an abnormal sleep microstructure and abnormal autonomic response with a selective loss of hypocretin-containing neurons in narcolepsy. Fifteen patients with narcolepsy-cataplexy (mean age 35±8.5; age range 22-44), and 15 age and sex matched controls (mean age 31±11.4; age range 19-48) were included in the study. All subjects underwent polysomnography recordings for two consecutive nights in a standard laboratory setting. The sleep scoring was focused on the CAP and HRV analysis. A significant decrease in CAP rate as well as significant reduction of the LF spectral band and the LF/HF ratio, and the elevation of the HF spectral component during NREM 4 stage were revealed in narcoleptics compared to controls. Our results suggest that physiological fluctuation of arousal during sleep described as CAP is impaired in narcolepsy and accompained by reduced sympathetic tone during SWS. We have hypothesized that the whole sleep regulation process is altered in narcolepsy and not only REM sleep mechanisms.
- MeSH
- elektroencefalografie metody využití MeSH
- finanční podpora výzkumu jako téma MeSH
- interpretace statistických dat MeSH
- lidé MeSH
- narkolepsie diagnóza etiologie MeSH
- neuropeptidy nedostatek MeSH
- poruchy spánku a bdění diagnóza etiologie patofyziologie MeSH
- spánek REM fyziologie MeSH
- srdeční frekvence fyziologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- srovnávací studie MeSH
Acrylamide (AA) is one of the most common toxins in foods. Its effect on bone microstructure has not been investigated. The aim of our study was to analyze the impact of acute exposure to AA on femoral bone microstructure in mice. Adult animals were treated perorally with 2 doses of AA (E1 group, 1 mg/kg b.w.) in a 24-h period and with 3 doses of AA (E2 group, 1 mg/kg b.w.) in a 48-h period. Mice exposed to AA had smaller sizes of primary osteon's vascular canals. Secondary osteons were significantly smaller in mice from E2 group; however their increased number (from 38 % to 77 %) was identified in both E1 and E2 groups. In these groups, a higher number of resorption lacunae (from 100 % to 122 %) was also found. The values for bone volume, trabecular number were increased and that for trabecular separation was decreased in mice administered AA. Significantly higher value of bone surface was observed in mice from E1 group whereas trabecular thickness was increased in E2 group. The effect of AA on microstructure of compact and trabecular bone tissues is different. In our study, one dose of AA was used and acute effects of AA were investigated. Therefore, further studies are needed to study mechanisms by which AA acts on bone.
- MeSH
- akrylamid toxicita MeSH
- femur diagnostické zobrazování účinky léků patologie MeSH
- kontaminace potravin * MeSH
- kortikální kost diagnostické zobrazování účinky léků patologie MeSH
- myši MeSH
- rentgenová mikrotomografie MeSH
- trabekulární kostní tkáň diagnostické zobrazování účinky léků patologie MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
J. N. Čermák (Czermak) se narodil v Praze (1828) v rodině oddané lékařské vědě a praxi. Náležel k Purkyňovým žákům – ve Vratislavi jako jeho student, později v Praze jako jeho asistent. Čermák působil jako profesor fyziologie na několika univerzitách v Rakousku ve Štýrskem Hradci, v Krakově a v Pešti. Byl považován za nejvhodnějšího Purkyňova nástupce, avšak Purkyně Čermákovo přání pracovat v Praze vedle něho jako mimořádný profesor zdvořile, ale rozhodně odmítl. Čermák přijímá pozvání univerzity v Jeně a konečně v Lipsku, kde roku 1873 umírá. Čermákovo jméno je ve stomatologické literatuře známé ve spojení s popisem interglobulárních prostor v dentinu. Jeho výzkum se zabývá také fyziologií smyslů a řeči, závrati, cirkulace krve. Proslulost získal vypracováním metody vyšetření hrtanu zrcátkem vlastní konstrukce a zavedením zadní rhinoskopie.
J. N. Čermák (Czermak) was born in Prague (1828) in a family devoted to medical practice and science.He belongs to Purkyně's pupils – in Wroclav as his student, later in Prague as his assistant. Čermak as professor of physiology was active at several universities in Graz, Cracow, Pest .He was considered to be most suitable successor of Purkyně. But Purkyně Czearmak's wish to work as extraordinary Professor in Prague, politely, but firmly refuses. Čermak accepts invitation from university at Jena and finally from Leipzig, where in 1873 dies. Čermak's name is known in dental literature in connection with the description of interglobular spaces in dentin. His research also concerns the physiology of senses, of voice, vertigo, blood circulation. He became famous for the elaboration of method for larynx examination by the mirror of his own construction and the introduction of posterior rhinoscopy.
- Klíčová slova
- interglobulární dentin,
- MeSH
- dějiny 19. století MeSH
- fyziologie MeSH
- laryngoskopie MeSH
- Check Tag
- dějiny 19. století MeSH
- Publikační typ
- biografie MeSH
- O autorovi
- Čermák, Jan Nepomuk, 1828-1873 Autorita
Our study aimed to investigate subacute exposure to alcohol in relation to bone microstructure of mice. Animals from experimental (E) group drank a solution composed of 15 % ethanol and water for 14 days (one remodeling cycle), while those from control (C) group drank only water. In the compact bone of E group, decreased bone formation and increased porosity were observed which corresponds with lower levels of serum alkaline phosphatase and glutathione. Alcohol significantly increased sizes of primary osteon's vascular canals and decreased those of secondary osteons, Haversian canals. Relative bone volume, bone mineral density (BMD), relative bone volume without marrow cavity were also lower in E group. On the contrary, trabecular bone microstructure did not differ significantly between E and C groups. Liver function test showed higher levels of alanine aminotransferase, aspartate aminotransferase in alcohol-fed mice. Serum calcium, phosphate were significantly lower in E group. According to our study, only changes in compact bone microstructure of mice following one remodeling cycle were observed due to both direct and indirect effects of alcohol.
- MeSH
- ethanol aplikace a dávkování toxicita MeSH
- kostní denzita účinky léků fyziologie MeSH
- kostní matrix diagnostické zobrazování účinky léků fyziologie MeSH
- myši MeSH
- zobrazování trojrozměrné metody MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
The neural architecture of the corpus callosum shows pronounced inter-individual differences. These differences are thought to affect timing of interhemispheric interactions and, in turn, functional hemispheric asymmetries. The present study aimed at elucidating the neuronal mechanisms underlying this relationship. To this end, we used a combined DTI and EEG study design. In 103 right-handed and healthy adult participants, we determined the microstructural integrity of the posterior third of the corpus callosum and examined in how far this microstructural integrity was related to between-hemisphere timing differences in neurophysiological correlates of attentional processes in the dichotic listening task. The results show that microstructural integrity of the posterior callosal third correlated with attentional timing differences in a verbal dichotic listening condition but not in a noise control condition. Hence, this association between callosal microstructure and between-hemisphere timing differences is specific for stimuli, which trigger hemispheric bottom-up processing in an asymmetric fashion. Specifically, higher microstructural integrity was associated with decreased left-right differences in the latency of the N1 event-related potential component and hence more symmetric processing of dichotic stimuli between the two hemispheres. Our data suggest that microstructure of the posterior callosal third affects functional hemispheric asymmetries by modulating the timing of interhemispheric interactions.
- MeSH
- corpus callosum fyziologie MeSH
- dospělí MeSH
- elektroencefalografie MeSH
- funkční lateralita fyziologie MeSH
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- zobrazování difuzních tenzorů MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
An increase in procollagen type I amino-terminal propeptide (PINP) early after teriparatide initiation was shown to correlate with increased lumbar spine areal BMD and is a good predictor of the anabolic response to teriparatide. Few data exist correlating PINP and bone microstructure, and no data exist in patients on teriparatide following prior potent antiresorptive treatment. This exploratory analysis aimed to investigate the effects of teriparatide on cancellous bone microstructure and correlations of bone markers with microstructure in alendronate-pretreated patients. This was a post hoc analysis of changes in bone markers and three-dimensional indices of bone microstructure in paired iliac crest biopsies from a prospective teriparatide treatment study in postmenopausal women with osteoporosis who were either treatment-naïve (TN, n=16) or alendronate-pretreated (ALN, n=29) at teriparatide initiation. Teriparatide (20μg/day) was given for 24months; biopsies were taken at baseline and endpoint, and serum concentrations of PINP and type 1 collagen cross-linked C-telopeptide (βCTX) were measured at intervals up to 24months. In the TN and ALN groups, respectively, mean (SD) increases in three-dimensional bone volume/tissue volume were 105 (356)% (P=0.039) and 55 (139)% (P<0.005) and trabecular thickness 30.4 (30)% (P<0.001) and 30.8 (53)% (P<0.001). No significant changes were observed in trabecular number or separation. In the ALN patients, 3-month change of neither PINP nor βCTX correlated with indices of cancellous bone microstructure. However, 12-month changes in biochemical bone markers correlated significantly with improvements in bone volume/tissue volume, r=0.502 (P<0.01) and r=0.378 (P<0.05), trabecular number, r=0.559 (P<0.01) and r=0.515 (P<0.01), and reduction of trabecular separation, r=-0.432 (P<0.05) and r=-0.530 (P<0.01), for PINP and βCTX, respectively. We conclude that cancellous bone microstructure improved with teriparatide therapy irrespective of prior antiresorptive use.
- MeSH
- alendronát terapeutické užití MeSH
- inhibitory kostní resorpce terapeutické užití MeSH
- kolagen typu I krev MeSH
- kostní denzita účinky léků MeSH
- lidé středního věku MeSH
- lidé MeSH
- peptidové fragmenty krev MeSH
- peptidy krev MeSH
- postmenopauzální osteoporóza farmakoterapie MeSH
- prokolagen krev MeSH
- remodelace kosti účinky léků MeSH
- senioři MeSH
- teriparatid terapeutické užití MeSH
- trabekulární kostní tkáň účinky léků MeSH
- Check Tag
- lidé středního věku MeSH
- lidé MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- klinické zkoušky MeSH
- multicentrická studie MeSH
- práce podpořená grantem MeSH
