Freezing and lyophilization have been utilized for decades to stabilize pharmaceutical and food products. Freezing a solution that contains dissolved salt and/or organic matter produces pure primary ice crystal grains separated by freeze-concentrated solutions (FCS). The microscopic size of the primary ice crystals depends on the cooling conditions and the concentration of the solutes. It is generally accepted that primary ice crystals size influences the rate of sublimation and also can impact physico-chemical behaviour of the species in the FCS. This article, however, presents a case where the secondary ice formed inside the FCS plays a critical role. We microscoped the structures of ice-cast FCS with an environmental scanning electron microscope and applied the aggregation-sensitive spectroscopic probe methylene blue to determine how the microstructure affects the molecular arrangement. We show that slow cooling at -50 °C produces large salt crystals with a small specific surface, resulting in a high degree of molecular aggregation within the FCS. In contrast, fast liquid nitrogen cooling yields an ultrafine structure of salt crystals having a large specific surface area and, therefore, inducing smaller aggregation. The study highlights a critical role of secondary ice in solute aggregation and introduces methylene blue as a molecular probe to investigate freezing behaviour of aqueous systems with crystalline solute.
- MeSH
- led * MeSH
- lyofilizace MeSH
- methylenová modř * MeSH
- roztoky MeSH
- voda chemie MeSH
- zmrazování MeSH
- Publikační typ
- časopisecké články MeSH
- Klíčová slova
- gama sonda, magnetická detekce sentinelové uzliny,
- MeSH
- biopsie sentinelové lymfatické uzliny MeSH
- lidé MeSH
- lymfoscintigrafie metody MeSH
- melanom diagnostické zobrazování diagnóza MeSH
- methylenová modř aplikace a dávkování škodlivé účinky terapeutické užití MeSH
- nádory prsu diagnostické zobrazování diagnóza MeSH
- sentinelová uzlina * diagnostické zobrazování patologie MeSH
- Check Tag
- lidé MeSH
In this study, a mercury meniscus-modified silver solid amalgam electrode was used for the first time for the detection of UV-induced DNA damage. The integrity of the double-stranded DNA (dsDNA) layer was detected indirectly using the evaluation of the methylene blue reduction within its accumulation into dsDNA after the UV irradiation of the biosensor surface with two different wavelengths (254 nm and 365 nm), monitored by differential pulse voltammetry. Moreover, a simple electrochemical characterization of the biosensor surface was performed using cyclic voltammetry of the redox indicator hexaammineruthenium chloride (RuHex) present in the solution. Electrochemical impedance spectroscopy (EIS) was used in both cases for the verification of results. Individual electrochemical signals depend on the time of biosensor exposure to UV irradiation as well as on the selected wavelengths and are different for both used types of dsDNA (salmon sperm and calf thymus). The highest degradation degree up to 60% was observed using sensitive EIS of methylene blue after 10 min irradiation of the biosensor at 254 nm. The use of RuHex seems to be less sensitive for the detection of dsDNA structural changes, when the degradation degree up to 40% was observed, using EIS at the same conditions.
- MeSH
- biosenzitivní techniky * metody MeSH
- DNA chemie MeSH
- elektrochemické techniky metody MeSH
- elektrody MeSH
- lidé MeSH
- methylenová modř chemie MeSH
- poškození DNA MeSH
- sperma MeSH
- stříbro * MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
A series of new tertiary phenothiazine derivatives containing a quinoline and a pyridine fragment was synthesized by the reaction of 1-methyl-3-benzoylthio-4-butylthioquinolinium chloride with 3-aminopyridine derivatives bearing various substituents on the pyridine ring. The direction and mechanism of the cyclization reaction of intermediates with the structure of 1-methyl-4-(3-pyridyl)aminoquinolinium-3-thiolate was related to the substituents in the 2- and 4-pyridine position. The structures of the compounds were analyzed using 1H, 13C NMR (COSY, HSQC, HMBC) and X-ray analysis, respectively. Moreover, the antiproliferative activity against tumor cells (A549, T47D, SNB-19) and a normal cell line (NHDF) was tested. The antibacterial screening of all the compounds was conducted against the reference and quality control strain Staphylococcus aureus ATCC 29213, three clinical isolates of methicillin-resistant S. aureus (MRSA). In silico computation of the intermolecular similarity was performed using principal component analysis (PCA) and hierarchical clustering analysis (HCA) on the pool of structure/property-related descriptors calculated for the novel tetracyclic diazaphenothiazine derivatives. The distance-oriented property evaluation was correlated with the experimental anticancer activities and empirical lipophilicity as well. The quantitative shape-based comparison was conducted using the CoMSA method in order to indicate the potentially valid steric, electronic and lipophilic properties. Finally, the numerical sampling of similarity-related activity landscape (SALI) provided a subtle picture of the SAR trends.
- MeSH
- antibakteriální látky chemie farmakologie MeSH
- antitumorózní látky chemie farmakologie MeSH
- fenothiaziny chemie MeSH
- heterocyklické sloučeniny chemie MeSH
- lidé MeSH
- mikrobiální testy citlivosti MeSH
- nádorové buňky kultivované MeSH
- nádory farmakoterapie MeSH
- Staphylococcus aureus účinky léků MeSH
- vztahy mezi strukturou a aktivitou MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- MeSH
- amisulprid aplikace a dávkování terapeutické užití MeSH
- antipsychotika aplikace a dávkování terapeutické užití MeSH
- aripiprazol aplikace a dávkování terapeutické užití MeSH
- dospělí MeSH
- flufenazin aplikace a dávkování terapeutické užití MeSH
- klozapin aplikace a dávkování terapeutické užití MeSH
- lidé středního věku MeSH
- lidé MeSH
- paranoidní schizofrenie diagnóza farmakoterapie komplikace MeSH
- psychoterapie MeSH
- psychotické poruchy diagnóza farmakoterapie patologie MeSH
- schizofrenie a poruchy s psychotickými rysy * diagnóza farmakoterapie patofyziologie MeSH
- schizofrenie diagnóza farmakoterapie patofyziologie MeSH
- schizotypální porucha osobnosti diagnóza farmakoterapie MeSH
- výsledek terapie MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- kazuistiky MeSH
- MeSH
- dítě v pěstounské péči psychologie MeSH
- dospělí MeSH
- inteligenční testy MeSH
- lidé MeSH
- mentální retardace * diagnóza etiologie komplikace psychologie MeSH
- methotrimeprazin aplikace a dávkování terapeutické užití MeSH
- porucha chování etiologie farmakoterapie MeSH
- psychologické techniky MeSH
- psychoterapie metody MeSH
- výsledek terapie MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- ženské pohlaví MeSH
- Publikační typ
- kazuistiky MeSH
- MeSH
- antagonisté dopaminu metabolismus MeSH
- antidepresiva metabolismus MeSH
- antipsychotika metabolismus MeSH
- bronchodilatancia metabolismus MeSH
- flufenazin metabolismus MeSH
- induktory cytochromu P450 CYP1A2 metabolismus MeSH
- inhibitory proteinkinas metabolismus MeSH
- kontraceptiva orální hormonální metabolismus MeSH
- kouř analýza škodlivé účinky MeSH
- kouření cigaret škodlivé účinky MeSH
- látky pro odvykání kouření farmakologie metabolismus MeSH
- lékové interakce * MeSH
- lidé MeSH
- olanzapin metabolismus MeSH
- polycyklické aromatické uhlovodíky farmakokinetika farmakologie škodlivé účinky MeSH
- prostředky pro ukončení závislosti na tabáku MeSH
- theofylin farmakologie metabolismus MeSH
- vareniklin farmakokinetika farmakologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- přehledy MeSH
Since 2002, no clinical candidate against Alzheimer's disease has reached the market; hence, an effective therapy is urgently needed. We followed the so-called "multitarget directed ligand" approach and designed 36 novel tacrine-phenothiazine heterodimers which were in vitro evaluated for their anticholinesterase properties. The assessment of the structure-activity relationships of such derivatives highlighted compound 1dC as a potent and selective acetylcholinesterase inhibitor with IC50 = 8 nM and 1aA as a potent butyrylcholinesterase inhibitor with IC50 = 15 nM. Selected hybrids, namely, 1aC, 1bC, 1cC, 1dC, and 2dC, showed a significant inhibitory activity toward τ(306-336) peptide aggregation with percent inhibition ranging from 50.5 to 62.1%. Likewise, 1dC and 2dC exerted a remarkable ability to inhibit self-induced Aβ1-42 aggregation. Notwithstanding, in vitro studies displayed cytotoxicity toward HepG2 cells and cerebellar granule neurons; no pathophysiological abnormality was observed when 1dC was administered to mice at 14 mg/kg (i.p.). 1dC was also able to permeate to the CNS as shown by in vitro and in vivo models. The maximum brain concentration was close to the IC50 value for acetylcholinesterase inhibition with a relatively slow elimination half-time. 1dC showed an acceptable safety and good pharmacokinetic properties and a multifunctional biological profile.
- MeSH
- acetylcholinesterasa metabolismus MeSH
- Alzheimerova nemoc * farmakoterapie MeSH
- amyloidní beta-protein MeSH
- butyrylcholinesterasa metabolismus MeSH
- cholinesterasové inhibitory farmakologie MeSH
- fenothiaziny farmakologie MeSH
- myši MeSH
- racionální návrh léčiv MeSH
- takrin * farmakologie MeSH
- vztahy mezi strukturou a aktivitou MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Refrakterní distributivní šok představuje u kriticky nemocných stav s excesivní smrtností. Neadrenergní vasopresory, mezi které patří i methylenová modř, získávají stále na významu jako tzv. záchranná léčba u vazoparalytických stavů. V tomto přehledového článku shrnujeme dosavadní literární evidenci použití methylenové modři v indikaci refrakterního šoku u kriticky nemocných pacientů.
Refractory distributive shock is associated with excessive mortality in critically ill patients. Non-adrenergic vasopressors, including methylene blue, are often considered as an adjuvant therapy to the usual, catecholamine-based vasopressor treatment. In this narrative review we summarize the current scientific evidence on the use of methylene blue in the treatment of refractory distributive shock in different clinical situations.
- Klíčová slova
- distributivní šok, refrakterní šok, vaskulární hyporesponzivita,
- MeSH
- lidé MeSH
- methylenová modř * terapeutické užití MeSH
- šok * farmakoterapie MeSH
- vazoplegie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- přehledy MeSH
Laser ablation in liquid (LAL), one of the attractive methods for fabrication of nanoparticles, was used for the modification of carbon cloth (CC) by deposition of palladium nanoparticles (Pd NPs); a simple stirring method was deployed to deposit Pd NPs on the CC surface. Characterization techniques viz X-ray diffraction (XRD), Fourier transform infrared (FT-IR), scanning electron microscope (SEM), energy-dispersive X-ray spectrometry (EDS) and inductively coupled plasma atomic emission spectroscopy (ICP-AES) were applied to study the surface of the ensuing samples which confirmed that LAL technique managed to fabricate and deposit the Pd NPs on the surface of CC. In addition, the catalytic prowess of the carbon cloth-Pd NPs (CC/Pd NPs) was investigated in the NaBH4- or HCOOH-assisted reduction of assorted environmental pollutants in aqueous medium namely hexavalent chromium [Cr(VI)], 4-nitrophenol (4-NP), congo red (CR) and methylene blue (MB). The CC/Pd NPs system has advantages such as high stability/sustainability, high catalytic performance and easy reusability.
- MeSH
- chemické látky znečišťující vodu analýza chemie MeSH
- chrom MeSH
- katalýza MeSH
- Kongo červeň MeSH
- kovové nanočástice chemie MeSH
- lasery MeSH
- methylenová modř chemie MeSH
- nitrofenoly MeSH
- palladium chemie MeSH
- spektrometrie rentgenová emisní MeSH
- spektroskopie infračervená s Fourierovou transformací MeSH
- textilie MeSH
- uhlík MeSH
- Publikační typ
- časopisecké články MeSH