Cíl studie: Asymetrický dimethylarginin (ADMA) působí jako endogenní inhibitor syntázy oxidu dusnatého a je považován za nový kardiovaskulární rizikový faktor. Plazmatická koncentrace ADMA je zvýšená u nemocných léčených hemodialýzou (HD) a může u nich přispívat k endotelové dysfunkci. V literatuře bylo publikováno, že metabolismus ADMA je úzce spojen s metabolismem homocysteinu. Cílem naší studie bylo otestovat vztah ADMA a dalších kardiovaskulárních rizikových faktorů u HD nemocných. Typ studie: Observační. Pracoviště: Ústav klinické biochemie a hematologie a 1. interní klinika LF UK a FN v Plzni, Česká republika. Materiál a metody: Stanovili jsme hladiny ADMA metodou ELISA, celkový cholesterol a HDL-cholesterol, apolipoproteiny AI (apoA) a B (apoB), triglyceridy (TG), oxidované LDL částice (oxLDL), C-reaktivní protein (CRP) měřením ultrasenzitivní metodou, lipoprotein (a), látky reagující s kyselinou thiobarbiturovou (TBARS) a homocystein (Hcy) v plazmě u 176 dlouhodobě HD nemocných (70 žen, 106 mužů; průměrný věk ± SD = 66,4 ± 10,63 roků). Plazmatické hladiny ADMA jsme stanovili navíc u 73 zdravých mužů (průměrný věk ± SD = 48,15 ± 5,78 roků), kteří tvořili kontrolní skupinu. Pro porovnání koncentrace ADMA mezi těmito dvěma skupinami byl použit Wilcoxonův nepárový test. Vztahy mezi proměnnými ve skupině HD nemocných byly vyhodnoceny použitím korelačního koeficientu podle Spearmana. Nezávislost ADMA byla hodnocena mnohočetnou regresní analýzou. Výsledky: Průměrná koncentrace ADMA u skupiny HD nemocných byla statisticky významně vyšší než u kontrolní skupiny (1,13 ± 0,22; medián = 1,14 μmol/l vs 0,75 ± 0,15; median = 0,72 μmol/l; CI = 0,33 – 0,44; p < 0,001). Významné korelace byly nalezeny mezi BMI a oxLDL (r = 0,33; p < 0,001), apoA a CRP (r = -0,28; p < 0,001); apoB a oxLDL (r = 0,75; p < 0,001) a mezi TG a oxLDL (r = 0,45; p < 0,001). Žádný vztah nebyl nalezen mezi ADMA a Hcy (r = -0,07; p = 0,39). Mnohočetná regrese prokázala, že hladina ADMA je nezávislá na BMI, věku, i na všech ostatních měřených parametrech. Závěr: Hladina ADMA je nezávislá na všech ostatních kardiovaskulárních rizikových faktorech včetně homocysteinu u HD nemocných., Objective: Asymmetric dimethylarginine (ADMA) is an endogenous inhibitor of nitric oxide synthase and is regarded as a novel risk factor for cardiovascular disease. ADMA concentrations are increased in blood of haemodialysis (HD) patients and may contribute to endothelial dysfunction in them. It was published that the metabolic pathways of ADMA are connected to the metabolic cycle of homocysteine. The aim of our study was to test a relation of ADMA to other cardiovascular risk factors in HD patients. Design: Observational study. Settings: Institute of Clinical Biochemistry and Haematology and 1st Department of Internal Medicine of Charles University Medical Faculty and Faculty Hospital, Pilsen, Czech Republic. Material and Methods: We analysed ADMA levels by ELISA method, total and HDL cholesterols, apolipoproteins AI (apoA) and B (apoB), triglycerides (TG), oxidized LDL (oxLDL), C-reactive protein measured by ultrasensitive method (CRP), lipoprotein (a), thiobarbituric acid reactive substances (TBARS) and homocysteine (Hcy) in plasma of 176 chronically HD patients (70 females, 106 males; mean age ± SD = 66.4 ± 10.63 years). ADMA levels were determined also in 73 healthy men (mean age ± SD = 48.15 ± 5.78). Comparison of ADMA concentration between the two studied groups was performed by the Wilcoxon unpaired test. Relations among variables in the group of HD patients were evaluated using the Spearman correlation. Independence of ADMA was assessed by multiple regression analysis. Results: Average ADMA concentration in HD patients was significantly higher than control values (1.13 ± 0.22, median = 1.14 μmol/l vs. 0.75 ± 0.15, median = 0.72 μmol/l; CI = 0.33 to 0.44, p < 0.001). Interesting correlations were found between BMI and oxLDL (r = 0.33, p < 0.001), apoA and CRP (r = -0.28, p < 0.001), apoB and oxLDL (r = 0.75, p < 0.001) and finally TG and oxLDL (r = 0.45, p < 0.001). No correlation was found between ADMA and Hcy (r = -0.07, p = 0.39). Multiple regression analysis revealed that ADMA is independent from BMI, age and all other measured parameters. Conclusion: ADMA is independent of all other measured cardiovascular risk factors including homocysteine in HD patients., Roman Cibulka, R. Široká, D. Rajdl, and Lit. 20
Level of asymmetric dimethylarginine (ADMA) is elevated and endothelial progenitor cells (EPC) and stem cells (SC) are decreased in patients undergoing renal transplantation (Tx) and may contribute to cardiovascular complications. We tested the hypothesis that ADMA, EPC and SC can be influenced with regular physical exercise early after Tx. Blood samples of ADMA, EPC, SC, adipocytokines and metabolic parameters were randomly obtained from 50 transplant patients before and 6 months after exercise program (Group I). Fifty age, sex HLA typing, duration of dialysis and immunosupression regimen-matched non exercising transplant were examined as controls (Group II). After 6 months, in Group I ADMA decreased (3.50±0.45 vs 2.11±0.35 μmol/l, P<0.01) and was lower comparing to Grou II (P<0.01), SC and EPC also decreased (2816±600 vs 2071±480 cells/ml resp. 194±87 to 125±67 cells/ml, P<0.02). Next changes in Group I: adiponectin (P<0.01), leptin (P<0.01), resistin (P<0.02). Visfatin, blood lipids, HbA1c, insulin and blood pressure were also influenced by training program (P<0.05)., V. Teplan, I. Králová Lesná, J. Piťha, A. Mahrová, J. Racek, I. Valkovský, A. Sekerková, M. Štollová., and Obsahuje bibliografii
A recently discussed cardiovascular risk factor, asymmetric dimethylarginine (ADMA), is known to act as an endogenous inhibitor of endothelial nitric oxide synthase. The aim of this study was to establish 1) the relationship between ADMA and ultrasonographically or biochemically determined endothelial dysfunction in children, and 2) the effect of folate supplementation on these parameters. The study cohort included 32 children with familial hypercholesterolemia (FH), 30 with diabetes mellitus type 1 (DM1) and 30 age-matched healthy children as the control group. Furthermore, twenty-eight randomly selected FH and DM1 children were re-examined after 3-months supplementation with folic acid. Baseline levels of ADMA and oxidized low density lipoproteins (oxLDL) were significantly higher in FH group than in DM1 and healthy children. Children in DM1 group had significantly lower concentration of homocysteine, but ADMA levels were normal. Folic acid supplementation significantly lowered homocysteine and hsCRP levels in both FH and DM1 group; however, ADMA and oxLDL concentrations remained unaltered. In conclusion, ADMA and oxLDL appear to be associated with endothelial dysfunction in children with FH. Administration of folic acid did not influence these markers in both FH and DM1 children., P. Jehlička ... [et al.]., and Obsahuje seznam literatury
We complement the recently introduced classes of lower and upper semilinear copulas by two new classes, called vertical and horizontal semilinear copulas, and characterize the corresponding class of diagonals. The new copulas are in essence asymmetric, with maximum asymmetry given by 1/16. The only symmetric members turn out to be also lower and upper semilinear copulas, namely convex sums of Π and M.
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The gob side entry retaining with high water material is often used in coal mines. To study the stress evolution characteristics of surrounding rock and asymmetric support control technology of gob side entry retaining with high water material, the evolution law of stress and deformation of surrounding rock in gob side entry retaining during working face mining is studied by theoretical analysis, numerical simulation and field measurement. According to the stress variation of overlying strata during the mining process of the working face, the mechanical models before and after the basic roof fracture were established respectively. The stress and deformation of the filling body and the roof on the side of the filling body are larger, and the stress and deformation of the solid coal and the roof on the side of solid coal are smaller. The maximum stress is at 3 m away from the roadway. The first weighting step distance is 40 m and the periodic weighting step distance is 30 m. Based on the stress and deformation characteristics of the roadway surrounding, the roadway surrounding support is divided into filling bodyside, solid coal side, and middle part of roadway roof. The asymmetric support technology of "filling body+ double row hydraulic prop+ I-beam+ high-strength pretension anchor cable+ high-strength bolt" is proposed. The field engineering practice shows that the surrounding rock control effect of asymmetric support technology with high water material is good., Qiyuan Shan, Yongli Liu, Tao Li and Zhupeng Jin., and Obsahuje bibliografii
Hemispheric EEG slow-potential asymmetry (SPA) during a one-dimensional horizontal tracking task was recorded over Oi, O2, C3 and C4 electrode positions. The time instants of tracking error occurrences (CXJT events) and their corrections (IN events) were used as synchronization events in selected EEG epochs. The central values (medians) of amplitudes in the averaged 500 ms EEG epochs were used for SPA description. Significant negative correlations between medians calculated for the time epochs prior to and after the events were found indicating a specific influence of these events on SPA. Prior IN events the left hemisphere (represented by Oi and C3 positions only) was more negative than the right one, while it was significantly more positive after the same type of events. An opposite relationship was suggested for OUT events.
Stenóza cervikálního kanálu může vést ke kompresi krční míchy a představuje nejvýznamnější mechanický faktor v patofyziologii cervikální spondylogenní myelopatie. Míšní tkáň je však vůči kompresi poměrně odolná a k rozvoji manifestní myelopatie dochází až při vyšším stupni komprese a v kombinaci s dalšími patofyziologickými faktory, zejm. dynamickým faktorem a zevním traumatem. Asymptomatická spondylogenní komprese krční míchy (ASCCC) je velmi častým nálezem zvláště v populaci vyššího věku nad 50 let. Objektivizace a kvantifikace cervikální stenózy a komprese krční míchy jsou však nejednotné a nejsou jasně stanoveny prediktory progrese do manifestní myelopatie a s tím související indikace případné preventivní chirurgické dekomprese. Přehled obsahuje nejčastěji používané metody stanovení cervikální stenózy a cervikální míšní komprese pomocí zobrazovacích metod. Nativní radiogram a výpočetní tomografie mají význam v objektivizaci cervikální stenózy, zatímco dominantní metodou objektivizace míšní komprese je magnetická rezonance (MR). Z parametrů, které nejvíce korelují s klinickou manifestací komprese, jsou uváděny příčná plocha míchy v místě komprese a přítomnost intenzitních změn míšního signálu. Z novějších zobrazovacích modalit je nejcitlivější MR zobrazení tenzorů difúze. Z prognostických faktorů rozvoje manifestní myelopatie u ASCCC jsou obecně akceptovány přítomnost manifestní radikulopatie a abnormita motorických a senzomotorických evokovaných potenciálů. Význam zobrazovacích metod v predikci rozvoje manifestní myelopatie a benefit provedení preventivní dekomprese ve skupině nemocných s asymptomatickou kompresí a vyšším rizikem rozvoje manifestní myelopatie bude nutné ověřit dalšími studiemi., Cervical spinal stenosis may lead to cervical cord compression and represents the most important mechanical factor in pathophysiology of cervical spondylotic myelopathy. Medullar tissue is, however, rather resistant to compression and development of symptomatic myelopathy occurs only when higher degree stenosis is present and in combination with other pathophysiological factors, mainly dynamic compression and trauma. Asymptomatic spondylotic cervical cord compression (ASCCC) is a quite frequent finding in older population above the age of fifty. However, reliability of the methods used to verify and quantify cervical stenosis and cervical cord compression is low and clear predictors of development of symptomatic myelopathy and related indication of potential preventive surgical decompression in ASCCC have not been determined yet. The overview discusses the most frequently used methods to establish cervical spinal stenosis and cervical cord compression using imaging methods. Radiogram and especially computed tomography are important for verification of cervical spinal stenosis, while magnetic resonance imaging (MRI) is a preferable method to detect cervical cord compression. The cross‑sectional spinal cord area and T2 MRI spinal cord hyperintensity are among the parameters considered to be the most closely correlated with clinical manifestation of spinal cord compression. Among newly introduced imaging modalities, MRI diffusion tensor imaging seems to be the most promising one. The presence of symptomatic radiculopathy and abnormality of motor and somatosensory evoked potentials are among generally accepted predictors of symptomatic myelopathy. The importance of imaging methods as predictors of symptomatic myelopathy development as well as benefits of preventive surgical decompression in ASCCC individuals with high risk of developing symptomatic myelopathy is to be established in future studies. Key words: cervical spinal stenosis – cervical spondylotic myelopathy – asymptomatic spondylotic cervical cord compression – magnetic resonance imaging – diffusion tensor imaging –computed tomography The authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manuscript met the ICMJE “uniform requirements” for biomedical papers., and I. Kovalová, J. Bednařík, M. Keřkovský, B. Adamová, Z. Kadaňka
Kyselina močová je u človeka biologicky aktívny koncový produkt metabolizmu purínov. Zvýšené koncentrácie kyseliny močovej sprevádzajú metabolický syndróm a jeho komponenty už u detí a mladistvých. K hyperurikémii prispieva konzumácia nápojov prisládzaných fruktózou, nakoľko je jediným sacharidom, pri ktorého metabolizme vzniká kyselina močová. Súčasné vedomosti neumožňujú odlíšiť, či je hyperurikémia kauzálnou príčinou komponentov metabolického syndrómu, alebo len sprievodným znakom naznačujúcim zvýšené riziko vzniku kardiovaskulárnych ochorení. V súčasnosti neexistuje konsenzus či a ako liečiť asymptomatickú hyperurikémiu u detí a mladistvých. Zaujať zásadný postoj k týmto otázkam umožnia len výsledky randomizovaných kontrolovaných prospektívnych štúdií, ktoré poskytnú dôkazy o prospešných účinkoch tejto liečby na prevalenciu metabolického syndrómu a incidenciu kardiovaskulárnych chorôb., In humans, uric acid represents a biologically active end-product of purine nucleotides. Several studies in children and adolescents documented an association between hyperuricaemia and the components metabolic syndrome. High intake of fructose-sweetened beverages might increase uricaemia, since fructose is the only saccharide which metabolism results in the formation of uric acid. Current knowledge does not allow distinguishing whether hyperuricaemia is causally related to the components of metabolic syndrome, or rather represents a marker of an enhanced risk, and poor outcome. No guidelines exist whether or not to treat asymptomatic hyperuricaemia in the adolescents. Randomized controlled prospective clinical studies are needed to elucidate whether uric acid-lowering management would beneficially affect the prevalence of metabolic syndrome, and the incidence of cardiovascular disease., and Ivana Koborová, Radana Gurecká, Anna Hlavatá, Katarína Šebeková