- Klíčová slova
- plicní průtok,
- MeSH
- hemodynamické monitorování MeSH
- hemodynamika fyziologie MeSH
- lidé MeSH
- plicní hypertenze diagnóza klasifikace MeSH
- srdeční katetrizace * dějiny metody přístrojové vybavení MeSH
- termodiluce MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- přehledy MeSH
The increasing antibiotic resistance of microbial pathogens isolated from farm animals tissues and the environment has been the one of the most important challenges associated with the use of antibiotics. In order to achieve better production on a farm, animal feed is enriched with antibiotics often originally intended for therapeutic purposes, which may lead to notable increases in microbial resistance. One possible approach to decreasing the excessive use of antibiotics in livestock as well as antimicrobial resistance is utilizing the antimicrobial properties of natural substances. The aim of this study was to evaluate the antimicrobial activity of natural substances including carvacrol, thymol, eugenol, gallic acid, octyl gallate, cnicin and usnic acid against a wide spectrum of microorganisms. Cnicin was the only compound which was isolated from the plant with use of column chromatography. The antimicrobial activities of these natural substances were determined on the basis of their minimum inhibitory, minimum bactericidal and minimum fungicidal concentrations using the microdilution method. This determination of antimicrobial activity revealed thymol and cnicin to be effective natural substances against all tested microorganisms. Octyl gallate had a strong inhibitory and bactericidal effect against gram-positive bacteria and was the most effective against Candida strains. Usnic acid was shown to have the lowest minimum inhibitory concentrations for gram-positive bacteria. These results suggest the possible incorporation of natural substances in animal rearing in order to reduce the high amount of antibiotics which are not used directly to treat animal diseases.
- MeSH
- antibiotická rezistence MeSH
- antifungální látky analýza MeSH
- antiinfekční látky * analýza MeSH
- Bacteria MeSH
- Candida MeSH
- chov MeSH
- dobytek * MeSH
- indikátorové diluční techniky MeSH
- kultivační techniky MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- hodnotící studie MeSH
- práce podpořená grantem MeSH
Growing evidence of antibiotic-resistant pathogens is a serious medical issue that has to be addressed. Our antimicrobial research is focused on searching for novel small molecules that differ from the most clinically used antibiotics by chemical structure and mechanism. However, this fundamental research is like looking for a needle in a haystack. In addition, in vitro methods are time-consuming and expensive to screen large number of compounds in reasonable time. Off-target screening can represent a solution to find novel and effective antimicrobial agents that can eliminate these problems. Accordingly, molecular docking in the family of selected frentizole derivatives predicted their potential to inhibit bacterial nicotinate mononucleotide adenylyltransferase (NadD). This bacterial-essential specific enzyme has an important role in NAD metabolism. Thus, underlying mechanism of antimicrobials derived from frentizole would be interference with this biochemical process. Unfortunately, broth microdilution assay did not display any antimicrobial activity of tested compounds. On the other hand, herein we propose that off-target screening can facilitate searching for new drugs and that NadD could be a relevant target for antimicrobials.
- MeSH
- antiinfekční látky * chemie MeSH
- Bacteria MeSH
- benzothiazoly chemie MeSH
- indikátorové diluční techniky MeSH
- inhibitory enzymů chemie MeSH
- lidé MeSH
- nikotinamidnukleotidadenylyltransferasa * antagonisté a inhibitory MeSH
- simulace molekulového dockingu MeSH
- techniky in vitro MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- práce podpořená grantem MeSH
BACKGROUND: Many transfusion services determine the titer of potentially incompatible plasma-containing products by performing a one-dilution titer at their selected titer threshold. This study compared the results of immediate spin (IS) one-dilution titers determined by three methods with a reference standard method. METHODS: Plasma-containing products from group A and O donors were titered using the participant's routine IS one-dilution titer method. No time or temperature incubations were performed, and antihuman globulin reagent was not used. The samples were then tested using a reference method, which was a saline tube test with a 1-hour room temperature incubation; antihuman globulin was not used in the reference method. The results of the one-dilution titer were then compared to that obtained in the reference method. RESULTS: Nine centers participated in this study. There were 698 antibodies from 374 units tested by the manual IS tube one-dilution titer method; sensitivity was 0.88 (95% confidence interval [CI], 0.83-0.92), and specificity was 1.00 (95% CI, 0.98-1.00). There were 412 antibodies from 206 units tested by the manual and automated IS buffered gel card one-dilution titer method; sensitivity was 0.95 (95% CI, 0.91-0.98), and specificity was 0.87 (95% CI, 0.81-0.91). There were 98 antibodies from 49 units tested by an automated microplate IS one-dilution titer method; sensitivity was 0.76 (95% CI, 0.71-0.93), and specificity was 0.96 (95% CI, 0.92-0.99). All three methods had an accuracy rate of 90% or greater. CONCLUSION: The manual and automated one-dilution titer methods are suitable for screening plasma-containing units, although more evaluation of the automated microplate method might be required.
- MeSH
- ABO systém krevních skupin krev MeSH
- indikátorové diluční techniky MeSH
- isoprotilátky krev MeSH
- lidé MeSH
- nekompatibilita krevních skupin krev MeSH
- odběr biologického vzorku metody MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- multicentrická studie MeSH
- srovnávací studie MeSH
Microcystins are cyclic peptide toxins with hepatotoxic and tumor-promoting properties, which are produced in significant quantities (up to tens of μg/L) in freshwater cyanobacterial water blooms. Several studies reported microcystin accumulation in fish with possible food transfer to humans. These compounds are further metabolized to cysteine and glutathione conjugates which can be present in tissues in significant concentrations. In this study, we focused on the development and evaluation of robust and highly sensitive SPE-LC-MS/MS method for the analysis of microcystin conjugates in fish tissue samples. For the first time, we demonstrate the use of isotopically labeled internal standards which are essential for accurate and precise determination of analytes in complex biotic matrices. LLOQs of respective microcystin conjugates (signal-to-noise ratio; S/N > 10, peak-to-peak method) ranged from 3.3 to 5.0 ng/g of tissue fresh weight (FW). The calibration was linear within a range of concentrations from 1 to 70 ng/mL for all analyzed conjugates. The precision and repeatability of the method were very good with recoveries in the range of 88.5-107.6% and relative standard deviations between 8.8 and 13.2% for all analytes. In the follow-up study, fully validated method was used for the determination of microcystin conjugate levels in common carp exposed to microcystin-containing cyanobacterial biomass under controlled conditions. Significant amounts of microcystin conjugates (up to 55 ng/g) were found in the tissues of fish after 7 weeks of exposure. Our method was shown to be robust, sensitive, selective, and suitable for the determination of trace levels of microcystin conjugates in fish tissues.
- MeSH
- biomasa MeSH
- chromatografie kapalinová metody MeSH
- cystein analýza MeSH
- glutathion analýza MeSH
- limita detekce MeSH
- mikrocystiny analýza chemie MeSH
- radioisotopová diluční technika MeSH
- reprodukovatelnost výsledků MeSH
- sinice chemie MeSH
- tandemová hmotnostní spektrometrie metody MeSH
- Publikační typ
- časopisecké články MeSH
V polovině 90. let byla vyvinuta první metoda měření průtoku krve cévním přístupem (QVA) pro dialýzu „u lůžka“, využívající měřenínucené recirkulace při invertovaném zapojení jehel ultrazvukovou dilucí. Profylaktické měření QVA se poté stalo metodou volby připravidelném sledování stavu cévních přístupů a od roku 2016 je v ČR pojišťovnami hrazeným výkonem. Následně byla vyvinutařada alternativních metod měření QVA, většinou dilučních, ale i metod na jiném principu. Článek je přehledem všech těchto metod.Uvádí jejich principy (ultrazvuková diluce, termodiluce, optodiluce, optokoncentrace, iontová dialysance, vodivost, klasické duplexnídopplerovské měření i pouze dopplerovské měření rychlosti toku), přednosti a omezení i potřebné technické vybavení.Klíčová slova: cévní přístup, recirkulace, průtok krve, měření „u lůžka“, diluční metody, vodivost, dopplerovské měření.
In the mid-nineties, the first vascular access blood flow (QVA) measurement at the bedside has been developed, based on measurement of forced recirculation at inverted needles by ultrasonic dilution. Prophylactic QVA measurement soon became the method of choice in regular vascular access status assessment. Since 2016, this procedure is also reimbursed by all insurance companies in the Czech Republic. Subsequently, number of alternative methods of QVA evaluation was developed, mostly but not exclusively based on dilutional techniques. The article describes all those methods, their principles (ultrasonic dilution, thermodilution, optodilution/optoconcentration, ionic dialysance, conductivity step-wise change, conventional duplex-doppler and sole doppler velocity measurement), technical and performance pros and cons as well as technical means needed for practical implementation.
- Klíčová slova
- ultrazvuková diluce, optodiluce,
- MeSH
- cévní přístupy MeSH
- dialýza ledvin * metody přístrojové vybavení MeSH
- duplexní dopplerovská ultrasonografie MeSH
- hemodynamika MeSH
- krevní oběh MeSH
- lidé MeSH
- rychlost toku krve * MeSH
- termodiluce MeSH
- ultrafiltrace MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- práce podpořená grantem MeSH
- přehledy MeSH
INTRODUCTION: Various species of the Euphorbia genus contain diterpene ingenol and ingenol mebutate (ingenol-3-angelate), a substance found in the sap of the plant Euphorbia peplus and an inducer of cell death. A gel formulation of the drug has been approved by the US Food and Drug Administration (FDA) and the European Medicines Agency (EMA) for the topical treatment of actinic keratosis. OBJECTIVE: To develop a rapid and reliable method for quantification of ingenol in various plant extracts. METHODOLOGY: Methanolic extracts of 38 species of the Euphorbia genus were analysed via ultra-high performance liquid chromatography with tandem mass spectrometry (UHPLC-MS/MS) after methanolysis and solid-phase extraction (SPE) purification. The 18 O-labelled ingenol analogue was prepared and used as an internal standard for ingenol content determination and method validation. RESULTS: The highest ingenol concentration (547 mg/kg of dry weight) was found in the lower leafless stems of E. myrsinites. The screening confirms a substantial amount of ingenol in species studied previously and furthermore, reveals some new promising candidates. CONCLUSION: The newly established UHPLC-MS/MS method shows to be an appropriate tool for screening of the Euphorbia genus for ingenol content and allows selection of species suitable for raw material production and/or in vitro culture initiation. Copyright © 2017 John Wiley & Sons, Ltd.
In the early stage of drug development the solubility of drug candidate is the most crucial physicochemical parameter to be defined for the selection of lead compound. Conventional shake flask method of solubility determination has now been replaced with more precise measurements like ultraviolet absorption, nephelometry, nuclear magnetic resonance and potentiometry. The development of a simple, rapid, sensitive and precise spectrophotometric method for the routine quantitative determination of samples will definitely reduce unnecessary tedious sample preparations and the cost of materials and labour. This article accounts for the measurement of solubility limit of few selected drugs by spectrophotometry using dilution technique. This has been done to optimize the method for rapid and convenient determination of drug solubility limit. Concentration of saturated solution of drug was determined from the absorbance versus concentration plots of various diluted solutions of drug as per Beer-Lambert law and was reported as drug solubility limit.
Cíl: Aktualizace problémů měřením 25-hydroxyvitaminu D v séru. Metoda: Informace z webových stránek a dokumentů mezinárodního programu standardizace vitaminu D (VDSP) a přehled recentních prací, týkajících se tématu. Výsledky: Prozatímní pozitivní efekt výsledků standardizace vitaminu D v programu VDSP není po cca jednom roce výrazný ani v preciznosti, ani v hodnotách bias měření. Vcelku podle očekávání mají větší problémy s analytickou kvalitou imunochemické metody než separační. Proces standardizace pokračuje v roce 2016 testováním komutability kontrolních materiálů CAP USA a DEQAS UK, které jsou plánovány jako nástroje verifikace standardizačního procesu v rutinních klinických labo-ratořích. Velké úsilí je věnováno negativním vlivům na kvalitu a ovlivnění imunochemických metod, kterých je celá řada. Tyto vlivy jsou o to složitější, že jsou velmi rozdílné u různých imunochemických metod. Patří sem různá úroveň křížových reakcí u 25-hydroxyvitaminu D2, interference 24, 25-dihydroxyvitaminu D, vliv vazebného proteinu pro vitamin D (VDBP) a rozdílná reaktivita imunochemických metod pro 3-epi-25-hydroxyvitamin D3. Diskuse: Diference hodnot bias způsobují významné diference v počtech jedinců při klasifikaci deficience vitaminu D, vliv 3-epi-25-OH D3 může dělat problémy při měření a klasifikaci u dětí a ovlivnění výsledků VDBP problematizuje používání imunochemických metod u dialyzovaných pacientů.
Objective: Actualization of statement in 25-hydroxyvitamin D measurement. Method: Information from websites and other documents of international vitamin D standardization program VDSP and from recent publications deals with 25-hydroxyvitamin D measurements in human serum Results:After 1 year we can see that effect of international standardization program VDSP is negligible both in precision and bias values. Significantly higher problems with analytical quality show immunochemical methods than separate measurements. Standardization process VDSP continues in 2015-2016 by study of the commutability experiments.Their target is to create highly commutable control materials for CAP and DEQAS programs, assured reliable verification of standardization level in routine and research clinical laboratories. Many recent publications are devoted to assessment of components, negatively influenced the results of 25-hydroxyvitamin D measurements in serum samples. Objects of interest are namely 25-hydroxyvitamin D2 and its level of cross immunoreaction, influence on bias level by 24, 25-dihydroxyvitamin D content, problems with 3-epi-25-hydroxyvitamin D3, and also with vitamin D bound protein (VDSP). These influences, resulted to elevated bias values are much more frequented in immunochemical methods than in separate methods and are in different immunochemical methods very different. Discussion: Risk of increased bias values namely in immunochemical methods can decreased reliability of classification of deficiency by vitamin D in individual patients. It also can be the source of problems in analysis of children due to high concentration of 3-epi-25-hydroxyvitamin D3 and in analysis of dialyzed patients due to problems with VDBP.
- MeSH
- 24,25-dihydroxyvitamin D3 krev MeSH
- 25-hydroxyvitamin D 2 krev MeSH
- biochemická analýza krve metody normy MeSH
- chromatografie kapalinová normy MeSH
- kalcifediol krev MeSH
- kalibrace MeSH
- laboratoře MeSH
- laboratorní automatizace MeSH
- lidé MeSH
- protein vázající vitamin D krev MeSH
- radioisotopová diluční technika normy MeSH
- referenční standardy * MeSH
- reprodukovatelnost výsledků MeSH
- řízení kvality MeSH
- tandemová hmotnostní spektrometrie normy MeSH
- vitamin D * analogy a deriváty krev MeSH
- vysokoúčinná kapalinová chromatografie normy MeSH
- zkreslení výsledků (epidemiologie) * MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- práce podpořená grantem MeSH
- přehledy MeSH
- MeSH
- antinukleární protilátky imunologie krev MeSH
- autoprotilátky imunologie krev MeSH
- biosimilární léčivé přípravky * krev terapeutické užití MeSH
- fluorescenční protilátková technika nepřímá MeSH
- idiopatické střevní záněty farmakoterapie krev MeSH
- imunoenzymatické techniky * MeSH
- indikátorové diluční techniky MeSH
- infliximab * krev terapeutické užití MeSH
- lidé MeSH
- lineární modely MeSH
- monoklonální protilátky krev terapeutické užití MeSH
- protilátky imunologie krev MeSH
- reagenční diagnostické soupravy MeSH
- rozdělení chí kvadrát MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- hodnotící studie MeSH
- práce podpořená grantem MeSH
- srovnávací studie MeSH
