Propidium iodide (PI) and YO-PRO-1 (YPI) dyes are routinely used to determine sperm viability in many livestock species. It is commonly accepted that these dyes penetrate only sperm cells with damaged plasma membranes. Recently, however, the mechanism of dye uptake unrelated to damaged plasma membranes, but instead related to pannexin channels in dog and stallion sperm cells was demonstrated. This pilot study aimed to evaluate the role of pannexins in the uptake of PI and YPI dyes on Wallachian frozen-thawed ram spermatozoa by flow cytometry using probenecid, a specific inhibitor of pannexin channels. Additionally, the expression of pannexins in Wallachian sperm was evaluated directly (by qRT-PCR). The results demonstrate the active role of pannexin channels in the uptake of PI and YPI dyes on frozen-thawed Wallachian ram sperm. In conclusion, when using the PI or YPI exclusion assay to determine Wallachian frozen-thawed ram sperm viability, the danger of overestimating the number of spermatozoa with the damaged plasma membrane must be considered. The observed breed-specific, and more importantly, individual differences in gene expression as well as in dye uptake indicate the need for further studies.
- MeSH
- barvicí látky MeSH
- benzoxazoly MeSH
- chinolinové sloučeniny * MeSH
- jodidy * MeSH
- koně MeSH
- kryoprezervace metody veterinární MeSH
- pilotní projekty MeSH
- propidium MeSH
- psi MeSH
- sperma MeSH
- spermie MeSH
- uchování spermatu * veterinární metody MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- psi MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
The strong antifungal effect of sulfonated polystyrene nanoparticles (NPs) with an encapsulated tetraphenylporphyrin (TPP) photosensitizer is reported here. TPP is activated by visible light, resulting in the generation of singlet oxygen. Its antifungal action is potentiated in the presence of potassium iodide, yielding I2/I3−, another antifungal species. The NPs exhibit no dark toxicity, but a broad spectrum of antifungal photodynamic effects. The efficiency of this rapid killing (on the order of minutes) depends on the concentration of TPP NPs, potassium iodide, yeast species and temperature. A strong antifungal activity of TPP NPs is demonstrated on eleven pathogenic and opportunistic pathogenic yeast species (six Candida species and other yeast species, including melanized Hortaea werneckii). The composition and architecture of yeast cell envelope structures clearly influence the efficacy of photodynamic therapy. Candida krusei is the most sensitive to photodynamic therapy. Despite expectations, melanin does not provide Hortaea cells with marked resistance compared to white yeast species. The kinetics of the interaction of NPs with yeast cells is also described. This study may inspire and promote the fabrication of a new type of antiseptic for various skin injuries in clinical medicine.
A new mechanism for the abiotic production of molecular iodine (I2) from iodate (IO3-), which is the most abundant iodine species, in dark conditions was identified and investigated. The production of I2 in aqueous solution containing IO3- and nitrite (NO2-) at 25 °C was negligible. However, the redox chemical reaction between IO3- and NO2- rapidly proceeded in frozen solution at -20 °C, which resulted in the production of I2, I-, and NO3-. The rapid redox chemical reaction between IO3- and NO2- in frozen solution is ascribed to the accumulation of IO3-, NO2-, and protons in the liquid regions between ice crystals during freezing (freeze concentration effect). This freeze concentration effect was verified by confocal Raman microscopy for the solute concentration and UV-visible absorption spectroscopy with cresol red (acid-base indicator) for the proton concentration. The freezing-induced production of I2 in the presence of IO3- and NO2- was observed under various conditions, which suggests this abiotic process for I2 production is not restricted to a specific region and occurs in many cold regions. NO2--induced activation of IO3- to I2 in frozen solution may help explain why the measured values of iodine are larger than the modeled values in some polar areas.
- MeSH
- dusitany MeSH
- jod * MeSH
- jodičnany * MeSH
- jodidy MeSH
- zmrazování MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Aqueous dispersions of sulfonated polystyrene nanoparticles (average diameter: 30 ± 14 nm) with encapsulated 5,10,15,20-tetraphenylporphyrin (TPP) are promising candidates for antibacterial treatments due to the photogeneration of cytotoxic singlet oxygen species O2(1Δg) under physiological conditions using visible light. The antibacterial effect on gram-negative Escherichia coli was significantly enhanced after the addition of nontoxic potassium iodide (0.001-0.01 M) because photogenerated O2(1Δg) oxidized iodide to I2/I3-, which is another antibacterial species. The improved antibacterial properties were predicted using luminescence measurements of O2(1Δg), transient absorption of TPP triplets and singlet oxygen-sensitized delayed fluorescence (SODF). In contrast to a solution of free photosensitizers, the aqueous dispersion of photoactive nanoparticles did not exhibit any quenching of the excited states after the addition of iodide or any tendency toward aggregation and/or I3--induced photo-aggregation. We also observed a decrease in the lifetime of O2(1Δg) and a significant increase in SODF intensity at higher temperatures, due to the increased oxygen diffusion coefficient in nanoparticles and aqueous surroundings. This effect corresponds with the significantly stronger antibacterial effect of nanoparticles at physiological temperature (37 °C) in comparison with that at room temperature (25 °C).
- MeSH
- antibakteriální látky farmakologie MeSH
- časové faktory MeSH
- Escherichia coli účinky léků MeSH
- fotosenzibilizující látky farmakologie MeSH
- jodidy farmakologie MeSH
- kinetika MeSH
- luminiscence MeSH
- mikrobiální testy citlivosti MeSH
- nanočástice chemie ultrastruktura MeSH
- nanovlákna chemie ultrastruktura MeSH
- teplota * MeSH
- Publikační typ
- časopisecké články MeSH
Coumarin derivatives are well known fluorescence reporters for investigating biological systems due to their strong micro-environment sensitivity. Despite having wide range of environment sensitive fluorescence probes, the potential of 6,7-dimethoxy-coumarin has not been studied extensively so far. With a perspective of its use in protein studies, namely using the unnatural amino acid technology or as a substrate for hydrolase enzymes, we study acetyloxymethyl-6,7-dimethoxycoumarin (Ac-DMC). We investigate the photophysics and hydration dynamics of this dye in aerosol-OT (AOT) reverse micelles at various water contents using the time dependent fluorescence shift (TDFS) method. The TDFS response in AOT reverse micelles from water/surfactant ratio of 0 to 20 confirms its sensitivity towards the hydration and mobility of its microenvironment. Moreover, we show that the fluorophore can be efficiently quenched by halide ions. Hence, we conclude that the 6,7-dimethoxy-methylcoumarin fluorophore is useful for studying hydration parameters in biologically relevant systems.
In order to increase the early warning ability of the radiation monitoring network of the Czech republic, a high-volume aerosol sampler was upgraded with a NaI(Tl) probe placed directly above the aerosol filter. The paper demonstrates the possibility of using a method based on principal component regression to accurately subtract the complicated natural background caused by radon decay products. This approach yielded minimum detectable activities of 8mBq/m3, 3mBq/m3 and 7mBq/m3 for 131I, 134Cs and 137Cs, respectively, after 24h of sampling.
- MeSH
- aerosoly MeSH
- algoritmy MeSH
- analýza hlavních komponent MeSH
- jodidy MeSH
- lidé MeSH
- monitorování radiace přístrojové vybavení metody statistika a číselné údaje MeSH
- radioaktivní látky znečišťující vzduch analýza MeSH
- radioizotopy cesia analýza MeSH
- radioizotopy jodu analýza MeSH
- regresní analýza MeSH
- sodík MeSH
- spektrometrie gama přístrojové vybavení metody statistika a číselné údaje MeSH
- thallium MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Česká republika MeSH
- MeSH
- agonisté adrenergních beta-receptorů terapeutické užití MeSH
- hormony kůry nadledvin terapeutické užití MeSH
- jodid draselný terapeutické užití MeSH
- kombinovaná farmakoterapie metody MeSH
- lidé MeSH
- management nemoci MeSH
- methimazol terapeutické užití MeSH
- propylthiouracil terapeutické užití MeSH
- průzkumy a dotazníky * MeSH
- retrospektivní studie MeSH
- stupeň závažnosti nemoci * MeSH
- thyreostatika terapeutické užití MeSH
- thyroxin krev MeSH
- trijodthyronin krev MeSH
- tyreotoxická krize * diagnóza farmakoterapie mortalita MeSH
- výsledek terapie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- souhrny MeSH
- Geografické názvy
- Japonsko MeSH
The presence of iodide (I(-)) in water during disinfection and oxidative treatment of water is a potential health concern because of the formation of iodinated disinfection by-products (DBPs), which may be more toxic than chlorinated DBPs. The kinetics of the oxidation of I(-) by a greener oxidant, ferrate(VI) (Fe(VI)O4(2-), Fe(VI)) was determined as a function of pH. The second-order rate constants (k, M(-1) s(-1)) decreased from 3.9 × 10(4) M(-1) s(-1) at pH 5.0 to 1.2 × 10(1) M(-1) s(-1) at pH 10.3. The kinetics results could be described by the reactivity of monoprotonated species of Fe(VI) (HFe(VI)O4(-)) with I(-). In excess I(-) concentration, triiodide (I3(-)) was formed and the stoichiometry of ∼1:1 ([Fe(VI)]:[I3(-)]) was found in both acidic and basic pH. Ferrate(V) (Fe(V)O4(3-), Fe(V)) and ferrate(IV) (Fe(VI)O4(4-), Fe(IV)) also showed the formation of I3(-) in presence of excess I(-). A mechanism of the formation of I3(-) is proposed, which is consistent with the observed stoichiometry of 1:1. The oxidative treatment of I(-) in water will be rapid (t1/2 = 0.6 s at pH 7.0 using 10 mg L(-1) K2FeO4). The implications of the results and their comparison with the oxidation of I(-) by conventional disinfectants/oxidants in water treatment are briefly discussed.
- MeSH
- chemické látky znečišťující vodu analýza chemie MeSH
- čištění vody metody MeSH
- dezinficiencia MeSH
- halogenace MeSH
- jodidy analýza chemie MeSH
- kinetika MeSH
- oxidace-redukce MeSH
- oxidancia chemie MeSH
- železo chemie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, U.S. Gov't, Non-P.H.S. MeSH
Recently performed environmental risk assessments of ivermectin demonstrated the need to complete the information regarding the fate of ivermectin in environment. There is also a lack of information concerning the fate and stability of praziquantel. The forced degradation study and photocatalytic degradation pathways in aqueous TiO2 suspensions of the two anthelmintics ivermectin and praziquantel were investigated and compared. The degradation efficiency increased for both compounds with the increase in the TiO2 concentration from 0.25 to 2.00 g L(-1), and then remained constant. The estimated k-values were from 0.36 h(-1) to 0.64 h(-1) for IVE and from 0.29 h(-1) to 0.47 h(-1) for PZQ, respectively. The degradation rate was not significantly impacted by the change of the pH value (pH 3, 5, 7, and 9) at 2.0 g L(-1) of TiO2. The photo degradation was about 90% for both compounds after 5 h of irradiation and it was significantly inhibited in the presence of iodide anion and isopropyl alcohol, which indicated, that hydroxyl radicals as well as holes contributed to the degradation of both anthelmintics. The contribution of hydroxyl radicals and holes was 92.1% for IVE and 93.2% for PZQ, respectively. Photocatalytic process of ivermectin resulted in three degradation intermediates; another two were formed during acidic and basic hydrolysis. Praziquantel underwent degradation to six degradation intermediates; four of them were formed under photocatalytic irradiation. The intermediates were identified using UHPLC-MS/MS. UV/TiO2 photolysis has been found as an effective advanced oxidation technology for the decontamination of ivermectin and praziquantel.
- MeSH
- 2-propanol chemie MeSH
- anthelmintika chemie MeSH
- chemické látky znečišťující vodu chemie MeSH
- čištění vody metody MeSH
- fotolýza MeSH
- ivermektin chemie MeSH
- jodidy chemie MeSH
- oxidace-redukce MeSH
- praziquantel chemie MeSH
- regenerace a remediace životního prostředí metody MeSH
- suspenze MeSH
- tandemová hmotnostní spektrometrie MeSH
- titan chemie účinky záření MeSH
- ultrafialové záření MeSH
- vysokoúčinná kapalinová chromatografie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- MeSH
- dítě MeSH
- exoftalmus MeSH
- jodidy aplikace a dávkování MeSH
- komplikace těhotenství MeSH
- lidé MeSH
- maternofetální výměna látek MeSH
- methimazol aplikace a dávkování MeSH
- nemoci novorozenců MeSH
- novorozenec s nízkou porodní hmotností krev MeSH
- novorozenec MeSH
- tachykardie diagnóza etiologie farmakoterapie MeSH
- tyreotoxikóza * diagnóza farmakoterapie krev MeSH
- Check Tag
- dítě MeSH
- lidé MeSH
- novorozenec MeSH
- Publikační typ
- kazuistiky MeSH
