An instrument integrating thermal desorption (TD) to selected ion flow tube mass spectrometry (SIFT-MS) is presented, and its application to analyze volatile organic compounds (VOCs) in human breath is demonstrated for the first time. The rationale behind this development is the need to analyze breath samples in large-scale multicenter clinical projects involving thousands of patients recruited in different hospitals. Following adapted guidelines for validating analytical techniques, we developed and validated a targeted analytical method for 21 compounds of diverse chemical class, chosen for their clinical and biological relevance. Validation has been carried out by two independent laboratories, using calibration standards and real breath samples from healthy volunteers. The merging of SIFT-MS and TD integrates the rapid analytical capabilities of SIFT-MS with the capacity to collect breath samples across multiple hospitals. Thanks to these features, the novel instrument has the potential to be easily employed in clinical practice.
The aim of the study was to investigate the hyaluronic acid concentration in middle ear fluid of patients with cleft palate as an indicator of the severity of the disease. Hyaluronic acid was examined in the middle ear fluid of 65 children (48 boys and 17 girls) subjected to cleft lip surgery in neonatal period up to 10 days of age. Patients were divided into 3 groups according to the course of the disease. First group consists of 15 patients with favorable course, second group consist of 25 patients with moderate course, third group included 25 patients with an adverse course. Hyaluronic acid levels were determined by commercially available immunoassay. The concentrations of hyaluronic acid in the middle ear fluid were as follows (mean+SEM): favorable course: 14253+2393 μg/l, moderate course: 7503+1345 μg/l, adverse course: 5905+2393 μg/l. Patients with adverse course and moderate course had significantly decreased hyaluronic acid levels in middle ear fluid compared to the patients with favorable course (P=0.02 and P=0.0018). Hyaluronic acid concentration is related to the course of the disease and the lowest values are most frequent in patients with an adverse course.
- MeSH
- imunoanalýza metody MeSH
- kyselina hyaluronová analýza MeSH
- lidé MeSH
- novorozenec MeSH
- otitis media s výpotkem komplikace diagnóza MeSH
- posouzení stavu pacienta MeSH
- rozštěp patra komplikace MeSH
- střední ucho chemie MeSH
- tělesné tekutiny chemie MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- novorozenec MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
The international standard ISO 23317:2014 for the in vitro testing of inorganic biomaterials in simulated body fluid (SBF) uses TRIS buffer to maintain neutral pH. In our previous papers, we investigated the interaction of a glass-ceramic scaffold with TRIS and HEPES buffers. Both of them speeded up glass-ceramic dissolution and hydroxyapatite (HAp) precipitation, thereby demonstrating their unsuitability for the in vitro testing of highly reactive biomaterials. In this article, we tested MOPS buffer (3-[N-morpholino] propanesulfonic acid), another amino acid from the group of "Goods buffers". A highly reactive glass-ceramic scaffold (derived from Bioglass®) was exposed to SBF under static-dynamic conditions for 13/15 days. The kinetics and morphology of the newly precipitated HAp were studied using two different concentrations of (PO4 )3- ions in SBF. The pH value and the SiIV , Ca2+ , and (PO4 )3- concentrations in the SBF leachate samples were measured every day (AAS, spectrophotometry). The glass-ceramic scaffold was monitored by SEM/EDS, XRD, WD-XRF, and BET before and after 1, 3, 7, 11, and 13/15 days of exposure. As in the case of TRIS and HEPES, the preferential dissolution of the glass-ceramic crystalline phase (Combeite) was observed, but less intensively. The lower concentration of (PO4 )3- ions slowed down the kinetics of HAp precipitation, thereby causing the disintegration of the scaffold structure. This phenomenon shows that the HAp phase was predominately generated by the presence of (PO4 )3- ions in the SBF, not in the glass-ceramic material. Irrespective of this, MOPS buffer is not suitable for the maintenance of pH in SBF.
In the present work, a disposable microextraction device with a polyamide 6 nano-fibrous supported liquid membrane (SLM) is employed for the pretreatment of minute volumes of biological fluids. The device is placed in a sample vial for an at-line coupling to a commercial capillary electrophoresis instrument with UV-Vis detection (CE-UV) and injections are performed fully automatically from the free acceptor solution above the SLM with no contact between the capillary and the membrane. Up to 4-fold enrichment of model basic (nortriptyline, haloperidol, loperamide, and papaverine) and acidic (ibuprofen, naproxen, ketoprofen, and diclofenac) drugs is achieved by optimizing the ratio of the donor to the acceptor solution volumes (16 to 4 μL, respectively). The actual setup enables SLM extractions from less than a drop of sample and is suitable for pretreatment of scarce human body fluids. Two unique methods are reported for efficient clean-up and enrichment of the basic and acidic drugs from capillary blood (formed as dried blood spot), serum, and urine samples, which enable their determination at therapeutic and/or toxic levels. The hyphenation of the SLM extraction with CE-UV analysis provides good repeatability (RSD, 2.4-14.9%), linearity (r2, 0.988-1.000), sensitivity (LOD, 0.017-0.22 mg L-1), and extraction recovery (ER, 20-106%) at short extraction times (10 min) and with minimum consumption of samples and reagents. Graphical abstract.
- MeSH
- elektroforéza kapilární metody MeSH
- koncentrace vodíkových iontů * MeSH
- léčivé přípravky metabolismus MeSH
- lidé MeSH
- membrány umělé * MeSH
- mikroextrakce kapalné fáze metody MeSH
- nanovlákna * MeSH
- reprodukovatelnost výsledků MeSH
- tělesné tekutiny chemie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Proteomics is one of the crucial methods used in biomarker discovery in various human diseases. The advantage of proteomics relies in its ability to identify disease-specific proteins. One very promising strategy is to analyze body fluids that are proximal to the organ of interest and are usually less complex than tissues or blood. Such an approach increases the chance for marker definition. This article reviews current knowledge on body fluid proteomics and proteomic biomarkers of human diseases and highlights mass spectrometry as one of the crucial methods in biomarker discovery.
- MeSH
- biologické markery * MeSH
- lidé MeSH
- nádorové biomarkery * MeSH
- tělesné tekutiny chemie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- práce podpořená grantem MeSH
Arsenic is one of the inorganic pollutants typically found in natural waters, and its toxic effects on the human body are currently of great concern. For this reason, the search for detoxifying agents that can be used in a so-called "chelation therapy" is of primary importance. However, to the aim of finding the thermodynamic behavior of efficient chelating agents, extensive speciation studies, capable of reproducing physiological conditions in terms of pH, temperature, and ionic strength, are in order. Here, we report on the acid-base properties of meso-2,3-dimercaptosuccinic acid (DMSA) at different temperatures (i.e., T = 288.15, 298.15, 310.15, and 318.15 K). In particular, its capability to interact with As(III) has been investigated by experimentally evaluating some crucial thermodynamic parameters (ΔH and TΔS), stability constants, and its speciation model. Additionally, in order to gather information on the microscopic coordination modalities of As(III) with the functional groups of DMSA and, at the same time, to better interpret the experimental results, a series of state-of-the-art ab initio molecular dynamics simulations have been performed. For the sake of completeness, the sequestering capabilities of DMSA-a simple dithiol ligand-toward As(III) are directly compared with those recently emerged from similar analyses reported on monothiol ligands.
- MeSH
- arsen chemie izolace a purifikace MeSH
- chelátory chemie MeSH
- koncentrace vodíkových iontů MeSH
- kyselina dimerkaptojantarová chemie MeSH
- lidé MeSH
- ligandy MeSH
- molekulární struktura MeSH
- simulace molekulární dynamiky MeSH
- tělesné tekutiny chemie MeSH
- termodynamika MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The effect of membrane thickness on extraction performance was systematically examined in extractions through supported liquid membranes (SLM), which were in-line coupled to capillary electrophoresis (CE). Three porous polypropylene membranes with different thickness (25, 100 and 170 μm) were used as supports for SLM extractions of model basic drugs (nortriptyline, papaverine, haloperidol and loperamide) from complex samples. The analytes were transferred through the SLMs by a pH gradient and were in-line injected, separated and quantified using a commercial CE instrument with ultraviolet (UV) detection. Transfers of the model drugs through SLM decreased with the increased membrane thickness (in the order: 25 > 100 > 170 μm) and highest transfers were achieved for the thinnest membrane. Interferences from complex sample matrices were efficiently eliminated, moreover, impregnation of the 25 μm membrane required significantly reduced volume of organic solvent. Mechanical stability of the impregnated 25 μm membrane was excellent during in-line injections, which necessitated direct contact of CE separation capillary with the SLM. Repeatability of the hyphenated SLM-CE-UV method (using the 25 μm membrane) was lower than 11% (RSD values of peak areas) and calibration curves were strictly linear in 0.5-30 μg/mL concentration range (coefficients of determination ≥ 0.997). Transfers of the basic drugs from donor solutions (standard and undiluted human urine/plasma) through the SLMs ranged from 45 to 231% and limits of detection were between 0.02 and 0.15 μg/mL.
An international standard (ISO: 23317:2014) exists for the in vitro testing of inorganic biomaterials in simulated body fluid (SBF). This standard uses TRIS buffer to maintain neutral pH in SBF, but in our previous paper, we showed that the interaction of a tested glass-ceramic material with TRIS can produce false-positive results. In this study, we evaluated whether the HEPES buffer, which also belongs to the group of Good´s buffers, would be more suitable for SBF. We compared its suitability in two media: SBF with HEPES and demineralized water with HEPES. The tested scaffold (45S5 bioactive glass-based) was exposed to the media under a static-dynamic arrangement (solutions were replaced on a daily basis) for 15 days. Leachate samples were collected daily for the analysis of Ca2+ ions and Si (AAS), (PO4 )3- ions (UV-VIS), and to measure pH. The glass-ceramic scaffold was analyzed by SEM/EDS, XRD, and WD-XRF before and after 0.3, 1, 3, 7, 11, and 15 days of exposure. Our results confirmed the rapid selective dissolution of the glass-ceramic crystalline phase (Combeite) containing Ca2+ ions due to the presence of HEPES, hydroxyapatite supersaturation being reached within 24 h in both solutions. These new results suggest that, like TRIS, HEPES buffer is not suitable for the in vitro testing of highly reactive inorganic biomaterials (glass, glass-ceramics). The ISO standard for such tests requires revision, but HEPES is not a viable alternative to TRIS buffer. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 143-152, 2018.
V autorově pojetí je homeostáza základní životní funkcí. Upozorňuje na úskalí sledování změn homeostázy a na postupy, jak změny homeostázy řešit. Z teoretických základů a z mnohaletých zkušeností uvádí praktické příklady, jak pomáhat organismu zachovat dynamickou rovnováhu ve vnitřním prostředí.
In the author‘s concept is homeostasis an essential vital life function. Draws attention to the pitfalls of tracking changes of homeostasis and procedures as changes of homeostasis to deal with. Of the theoretical foundations and many years of experience provides practical examples of how to help the body maintain dynamic equilibrium in the internal environment.
- MeSH
- acidobazická rovnováha fyziologie účinky léků MeSH
- dítě MeSH
- dospělí MeSH
- elektrická impedance MeSH
- elektrokardiografie využití MeSH
- homeostáza * fyziologie účinky léků MeSH
- hypoglykemie diagnóza prevence a kontrola terapie MeSH
- hypovolemie diagnóza prevence a kontrola terapie MeSH
- hypoxie diagnóza etiologie terapie MeSH
- klinické chemické testy * metody využití MeSH
- lidé MeSH
- nepřímá kalorimetrie metody využití MeSH
- osmolární koncentrace MeSH
- referenční hodnoty MeSH
- resuscitační péče metody využití MeSH
- statistika jako téma MeSH
- tělesné tekutiny * fyziologie chemie účinky léků MeSH
- vodní a elektrolytová rovnováha fyziologie účinky léků MeSH
- Check Tag
- dítě MeSH
- dospělí MeSH
- lidé MeSH
- Publikační typ
- přehledy MeSH
Oxycodone is a widely prescribed, full agonist opioid analgesic. As such, it is used clinically to treat different kinds of painful conditions, with a relatively high potential for doping practices in athletes. In this paper, different classic and innovative miniaturised matrices from blood and urine have been studied and compared, to evaluate their relative merits and drawbacks within therapeutic drug monitoring (TDM) and to implement new protocols for anti-doping analysis. Plasma, dried blood spots (DBS) and dried plasma spots (DPS) have been studied for TDM purposes, while urine, dried urine spots (DUS) and volumetric absorptive microsamples (VAMS) from urine for anti-doping. These sampling techniques were coupled to an original bioanalytical method based on liquid chromatography-tandem mass spectrometry (LC-MS/MS) for the evaluation and monitoring of the levels of oxycodone and its major metabolites (noroxycodone and oxymorphone) in patients under pain management and in athletes. The method was validated according to international guidelines, with good results in terms of precision, extraction yield and accuracy for all considered micromatrices. Thus, the proposed sampling, pre-treatment and analysis are attractive strategies for oxycodone determination in human blood and urine, with advanced options for application to derived micromatrices. Microsampling procedures have significant advantages over classic biological matrices like simplified sampling, storage and processing, but also in terms of precision (<9.0% for DBS, <7.7% for DPS, <7.1% for DUS, <5.3% for VAMS) and accuracy (>73% for DBS, >78% for DPS, >74% for DUS, >78% for VAMS). As regards extraction yield, traditional and miniaturised sampling approaches are comparable (>67% for DBS, >74% for DPS, >75% for DUS, >75% for VAMS). All dried matrices have very low volumes, leading to a significant advantage in terms of analysis feasibility. On the other hand, this also leads to a corresponding decrease in the overall sensitivity.
- MeSH
- chromatografie kapalinová metody MeSH
- doping ve sportu metody MeSH
- krevní plazma chemie MeSH
- lidé MeSH
- miniaturizace metody MeSH
- moč chemie MeSH
- monitorování léčiv metody MeSH
- morfinany krev moč MeSH
- odběr biologického vzorku metody MeSH
- odběr vzorku krve MeSH
- oxykodon krev moč MeSH
- oxymorfon krev moč MeSH
- tandemová hmotnostní spektrometrie metody MeSH
- tělesné tekutiny chemie MeSH
- test suché kapky krve metody MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
