Ever since proteomics was proven to be capable of characterizing a large number of differences in both protein quality and quantity, it has been applied in various areas of biomedicine, ranging from the deciphering molecular pathogenesis of diseases to the characterization of novel drug targets and the discovery of potential diagnostic biomarkers. Indeed, the biomarker discovery in human plasma is clearly one of the areas with enormous potential. However, without proper planning and implementation of specific techniques, the efforts and expectations may very easily be hampered. Numerous earlier projects aimed at clinical proteomics, characterized by exaggerated enthusiasm, often underestimated some principal obstacles of plasma biomarker discovery. Consequently, ambiguous and insignificant results soon led to a more critical view in this field. In this article, we critically review the current state of proteomic approaches for biomarker discovery and validation, in order to provide basic information and guidelines for both clinicians and researchers. These need to be closely considered prior to initiation of a project aimed at plasma biomarker discovery. We also present a short overview of recent applications of clinical proteomics in biomarker discovery., V. Tambor ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
Dental composite materials often contain monomers with bisphenol A (BPA) structure in their molecules, e.g. bisphenol-A glycidyl dimethacrylate (Bis-GMA). In this study, it was examined whether dental restorative composites could be a low-dose source of BPA or alternative bisphenols, which are known to have endocrine-disrupting effects. Bis-GMA-containing composites Charisma Classic (CC) and Filtek Ultimate Universal Restorative (FU) and “BPA-free” Charisma Diamond (CD) and Admira Fusion (AF) were examined. Specimens (diameter 6 mm, height 2 mm, n=5) were light-cured from one side for 20 s and stored at 37 °C in methanol which was periodically changed over 130 days to determine the kinetics of BPA release. BPA concentrations were measured using a dansyl chloride derivatization method with liquid chromatography - tandem mass spectrometry detection. The amounts of BPA were expressed in nanograms per gram of composite (ng/g). BPA release from Bis-GMA-containing CC and FU was significantly higher compared to “BPA-free” CD and AF. The highest 1-day release was detected with FU (15.4±0.8 ng/g), followed by CC (9.1±1.1 ng/g), AF (2.1±1.3 ng/g), and CD (1.6±0.8 ng/g), and the release gradually decreased over the examined period. Detected values were several orders of magnitude below the tolerable daily intake (4 µg/kg body weight/day). Alternative bisphenols were not detected. BPA was released even from “BPA-free” composites, although in significantly lower amounts than from Bis-GMA-containing composites. Despite incubation in methanol, detected amounts of BPA were substantially lower than current limits suggesting that dental composites should not pose a health risk if adequately polymerized., Markéta Šimková, Antonín Tichý, Michaela Dušková, Pavel Bradna., and Obsahuje bibliografii
Cíl studie: Na základě soudobých studií podat přehled o hlavních biologických funkcích lipoproteinů o vysoké hustotě (HDL), zejména ve vztahu k reverznímu transportu cholesterolu a k jejich protizánětlivému působení. Popsat pravděpodobné mechanismy vzniku dysfunkčních prozánětlivých HDL a uvést některé parametry asociované s tímto procesem. Podat přehled o laboratorních metodách stanovení kvantitativních, strukturních a funkčních vlastností HDL, včetně moderních metod založených na hmotové spektrometrii. Typ studie: přehledový článek Závěr: V případě systémového zánětu a/nebo oxidačního stresu dochází ke vzniku dysfunkčních HDL akumulujících oxidanty. Probíhá strukturní modifikace apolipoproteinu AI, což vede mimo jiné k inhibici reverzního transportu cholesterolu a tvorbě prozánětlivých HDL. Na ztrátě příznivých vlastností HDL se podílí modifikace proteinové i lipidové složky HDL. Izolované měření HDL cholesterolu nemusí u některých syndromů bezvýhradně korelovat s mírou kardiovaskulárního rizika a v některých situacích je vhodné stanovit markery mapující strukturu a funkci HDL., Objective: On the basis of recent studies to make an overview concerning the crucial biological functions of high density lipoproteins (HDL), with emphasis on the role in reverse cholesterol transport and their antiinflammatory traits. The aim was to describe probable mechanisms of dysfunctional proinflammatory HDL formation with introduction some of associated parameters. To present laboratory methods for determination of quantitative, structural and functional qualities of HDL, including advanced mass spectrometry techniques. Study design: review Conclusion: In the case of systemic inflammation and/or oxidative stress, the formation of dysfunctional HDL accumulating oxidants takes place, including apo AI structural modifications. This process can lead to the inhibition of reverse cholesterol transport and proinflammatory HDL generation, among others. Loss of beneficial qualities results from modification of both lipid and protein components of HDL. In some cases, an isolated quantitative measurement of HDL cholesterol may not fully correlate with cardiovascular risk and it is eligible to determine some of structural and/or functional markers of HDL., Novotný D., Karásek D., Vaverková H., Malina P., and Literatura
Příspěvek poskytuje přehlednou informaci o základních fyzikálních principech, na nichž pracují současné hmotnostní spektrometry, a informaci o základních principech některých důležitých soudobých hmotnostně spektrálních metod v biologickém výzkumu., Jiří Knížek, Zdeněk Půlpán, Martin Hubálek, Ladislav Beránek, Petr Pokorný., and Obsahuje seznam literatury
Cíl: Poskytnout základní přehled proteomických přístupů a metod a zhodnotit potenciál jejich využití v klinické praxi. Typ: Přehledová práce V klinické praxi roste význam laboratorních vyšetření pro zjištění aktuálního stavu pacientů. Mezi významnou skupinu molekul patří bezesporu proteiny, jejichž stanovení nejen umožňuje, ale i usnadňuje, urychluje a zpřesňuje diagnostiku. Hledání nových proteinových molekul s diagnostickým potenciálem se proto stalo jedním z důležitých cílů proteomiky. Proteomické přístupy zahrnující separaci a identifikaci molekul pomocí pokročilých analytických technologií a bioinformatiky jsou dnes využívány zejména při hledání nových potenciálních proteinových a peptidových markerů ve snadno dostupném klinickém materiálu. Některé proteomické metody začaly být využívány v posledních letech i pro následné ověřování diagnostického významu objevených markerů a v budoucnu mohou najít uplatnění i při rutinním laboratorním vyšetření. Cílem této práce je poskytnout základní přehled proteomických přístupů a metod a zhodnotit jejich význam pro klinickou praxi., Objective: The review provides basic overview of proteomic approaches and methods and evaluates their potential towards clinical practice. Design: Review The role of laboratory biomarker assessment in patient diagnosis determination has been increasing. Proteins unquestionably rank among very important molecules. Protein assessment of which not only enables, but can also accelerate and facilitate the diagnosis and make it more accurate. Hence, discovery of proteins with diagnostic potential has become one of the main goals of proteomics. Currently, proteomic approaches involving separation and identification of molecules by means of advanced analytical technologies and bioinformatics are typically used for the discovery of protein and peptide biomarkers in well accessible clinical material. However, in recent years some of the methods have been employed also for subsequent verification of the diagnostic potential of newly discovered biomarkers and are believed to be used also for routine laboratory settings in the future. The aim of the work is to provide an overview of proteomic approaches and methods and evaluate their relevance for clinical practice., Vajrychová M., Tambor V., Lenčo J., and Literatura 35
Cíl studie: Metabolomika se stává důležitým nástrojem v klinickém výzkumu a diagnostice lidských onemocnění. V této studii byla použita necílená metabolomická analýza suchých krevních skvrn (DBS) pro diagnostiku dědičných metabolických poruch (DMP). Typ studie: Klinická aplikace Materiál a metody: Vzorky DBS byly analyzovány technikou vysoce účinné kapalinové chromatografie ve spojení s hmotnostním spektrometrem s vysokým rozlišením. Data byla zpracována a statisticky vyhodnocena s použitím softwaru R. Výsledky: Bylo porovnáváno 20 kontrolních vzorků vůči třem vzorkům od pacientů s fenylketonurií a třem vzorkům od pacientů s leucinózou. Všechny pacientské vzorky se podařilo rozlišit od kontrolních na základě příslušných markerů jednotlivých onemocnění. Závěry: Tato studie ukazuje, že necílená metabolomika může být uplatněna při diagnostice DMP., Objective: Metabolomics has become an important tool in clinical research and diagnosis of human diseases. In this work we applied untargeted metabolomic analysis of dry blood spots (DBS) for diagnosing inherited metabolic disorders (IMDs). Design: Clinical application Material and methods: DBS samples were analyzed by high performance liquid chromatography coupled with high-resolution mass spectrometer. Data were processed and statistically evaluated using R software. Results: We compared 20 control samples with three samples from patients with phenylketonuria and three samples from patients with maple syrup urine disease. All patient samples were distinguished from controls based on appropriate markers of the disorders. Conclusion: This study shows that untargeted metabolomics can be applied for diagnosing various IMDs., Janečková H., Wojtowicz P., Hron K., Friedecký D., Adam T., and Literatura 5
The present study was undertaken to identify potentially immunoreactive proteins of the muscle larvae (ML) and adult stage (Ad) of the nematode Trichinella spiralis Owen, 1835. To identify immunoreactive proteins that are specifically recognised by anti-Trichinella antibodies, ML and Ad crude extracts and their excretory-secretory (E-S) products were subjected to sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblot with serum samples from pigs experimentally infected with T. spiralis. A total of 18 bands were selected for final identification by liquid chromatography-tandem mass spectrometry. To further understand the functions of the proteins identified in this study, gene ontology terms were applied. Results showed that the specific antibodies against T. spiralis reacted with protein bands matching heat shock proteins, aminopeptidase, enolase, isocitrate dehydrogenase NADP-dependent, tropomyosin, P49 antigen, serine proteinase, secreted 5'-nucleotidase, antigen targeted by protective antibodies, 53 kDa E-S antigen, putative trypsin and paramyosin. Three proteins common for both adult stage and muscle larvae, including heat shock proteins, enolase and 5'-nucleotidase, might play important role during T. spiralis infection. These proteins are presumably presented to the host immune system and may induce humoral immune response. Thus, these proteins may be potential antigens for early diagnosis and the development of a vaccine against the parasite., Justyna Bien, Wladyslaw Cabaj, Bozena Moskwa., and Obsahuje bibliografii
In this study, we presented a new approach for quantification of bicarbonate (HCO3-) molecules bound to PSII. Our method, which is based on a combination of membrane-inlet mass spectrometry (MIMS) and 18O-labelling, excludes the possibility of "non-accounted" HCO3- by avoiding (1) the employment of formate for removal of HCO3- from PSII, and (2) the extremely low concentrations of HCO3-/CO2 during online MIMS measurements. By equilibration of PSII sample to ambient CO2 concentration of dissolved CO2/HCO3-, the method ensures that all physiological binding sites are saturated before analysis. With this approach, we determined that in spinach PSII membrane fragments 1.1 ± 0.1 HCO3- are bound per PSII reaction center, while none was bound to isolated PsbO protein. Our present results confirmed that PSII binds one HCO3- molecule as ligand to the non-heme iron of PSII, while unbound HCO3- optimizes the water-splitting reactions by acting as a mobile proton shuttle., K. Tikhonov, D. Shevela, V. V. Klimov, J. Messinger., and Obsahuje bibliografické odkazy
Práce poskytuje stručný přehled metod stanovení 25-hydroxyvitaminu D v séru. Uvádíme informace o referenčních metodách, referenčních materiálech, o rutinních metodách separačních (LC-MS/MS) a imunochemických. Uveden je problém nedostatečné srovnatelnosti výsledků rutinních metod a systematických diferencí mezi nimi. Pojednáno je o možných interferencích, zejména vazebného proteinu pro vitamin D, o stavu kvality měření, požadavcích na kvalitu a o úrovni jeho standardizace. Stručně je pojednáno o interpretaci laboratorních výsledků měření a rozhodovacích limitech., Communication deals with brief, but complete rewiew of analytical methods of serum vitamin D determination. Reference methods, reference materials, routine separation LC-MS/MS methods and immunochemical methods are rewiewed. Lack of comparability, requirement on analytical quality, possibility of creation the reference system and bias against reference method are described. Interference of vitamin D bound protein (DBP) are introduced. Lack of of standardization is described. Basic information on the interpretation of results and on the cut off values are briefly published., Friedecký B., Vávrová J., and Literatura 24