We investigated the impact of the deletions of genes from the final steps in the biosynthesis of ergosterol (ERG6, ERG2, ERG3, ERG5, ERG4) on the physiological function of the Saccharomyces cerevisiae plasma membrane by a combination of biological tests and the diS-C3(3) fluorescence assay. Most of the erg mutants were more sensitive than the wild type to salt stress or cationic drugs, their susceptibilities were proportional to the hyperpolarization of their plasma membranes. The different sterol composition of the plasma membrane played an important role in the short-term and long-term processes that accompanied the exposure of erg strains to a hyperosmotic stress (effect on cell size, pH homeostasis and survival of yeasts), as well as in the resistance of cells to antifungal drugs. The pleiotropic drug-sensitive phenotypes of erg strains were, to a large extent, a result of the reduced efficiency of the Pdr5 efflux pump, which was shown to be more sensitive to the sterol content of the plasma membrane than Snq2p. In summary, the erg4Δ and erg6Δ mutants exhibited the most compromised phenotypes. As Erg6p is not involved in the cholesterol biosynthetic pathway, it may become a target for a new generation of antifungal drugs.

• MeSH
• ABC transportéry genetika   metabolismus   MeSH
• antifungální látky farmakologie   MeSH
• biosyntetické dráhy genetika   MeSH
• buněčná membrána chemie   fyziologie   MeSH
• ergosterol biosyntéza   chemie   MeSH
• flukonazol farmakologie   MeSH
• fluorescenční mikroskopie MeSH
• koncentrace vodíkových iontů MeSH
• membránové potenciály fyziologie   MeSH
• methyltransferasy genetika   metabolismus   MeSH
• mnohočetná fungální léková rezistence účinky léků   genetika   fyziologie   MeSH
• molekulární struktura MeSH
• mutace MeSH
• Saccharomyces cerevisiae - proteiny genetika   metabolismus   MeSH
• Saccharomyces cerevisiae chemie   genetika   fyziologie   MeSH
• tolerance k soli genetika   fyziologie   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

• MeSH
• cyklosporiny analogy a deriváty   aplikace a dávkování   farmakologie   MeSH
• fytogenní protinádorové látky aplikace a dávkování   farmakologie   terapeutické užití   MeSH
• HL-60 buňky účinky léků   účinky záření   MeSH
• lidé MeSH
• mnohočetná léková rezistence MeSH
• nádory vaječníků farmakoterapie   radioterapie   MeSH
• paclitaxel aplikace a dávkování   farmakologie   škodlivé účinky   MeSH
• tolerance záření účinky léků   MeSH
• Check Tag
• lidé MeSH
• ženské pohlaví MeSH

Od prvých prác v roku 1986 sa na významné miesto v možnostiach ochrany pred ischemickým poškodením nielen mozgu dostal fenomén tzv. ischemickej tolerancie spočívajúci v skutočnosti, že keď sa bunka dostane do styku so subletálnym stresom, nadobudne dočasne schopnosť prežiť aj za normálnych okolností zničujúce dávky stresu. Keď sa na tento fenomén pozrieme z iného uhla, čiže v snahe bunky zničiť, zisťujeme, že prvá dávka stresora, ktorá nezničila všetky bunky, stáva sa pre prežívajúce bunky a okolité tkanivo subletálnym stresom indukujúcim vznik tolerancie, tento fakt je však známy viac ako 100 rokov pod pojmom lieková rezistencia. Pohľad z obidvoch strán a využitie získaných poznatkov môže významne pomôcť tieto predložené závažné medicínske problémy riešiť.

Since first publications in 1986 phenomenon of ischemic tolerance ascended to important place in possible methods of protection not only brain against ischemia induced damage. This robust defense mechanism consist in fact that cell in contact with sublethal stress acquires transiently ability to survive normally lethal stress. However, if we require eliminate unwanted cells from organism and first dose of stress will not kill all cells it will induce in surviving cells tolerance. This phenomenon is in fact known more than 100 years as multidrug resistance. Complex examination from both sides could be very useful in solution of these important medical problems.

• Klíčová slova
• ischémia, ischemická tolerancia, mnohopočetná lieková rezistencia apoptóza,
• Publikační typ
• abstrakty MeSH

Multidrug resistant (MDR) bacteria are recognized to be one of the most important problems in public health. The outer membrane permeability is a critical intrinsic mechanism of bacterial resistance. In addition, bacteria produce a small number of dormant persister cells causing multidrug tolerance that reduces antimicrobial efficacy. This study aimed to evaluate the inhibitory effects of the combination of aromatic isothiocyanates (ITCs) with membrane-active agents on bacterial persisters and MDR Gram-negative bacteria. Our study demonstrated that membrane-active agents, particularly ethylenediaminetetraacetic acid (EDTA) synergistically enhanced the inhibitory activity of aromatic benzyl ITC and phenethyl ITC against most Gram-negative bacteria strains with fractional inhibitory concentration index values ranging from 0.18 to 0.5 and 0.16 to 0.5, respectively, and contributed to an 8- to 64-fold minimal inhibitory concentration reduction compared with those of aromatic ITCs alone. The EDTA-aromatic ITCs combination effectively reduced the survival rates of tested bacteria and significantly eradicated bacterial persisters (p = 0.033 and 0.037, respectively). The growth kinetics analysis also supported the enhanced inhibitory effect of EDTA-aromatic ITCs combination against tested bacteria. Our results suggested an alternate treatment strategy against Gram-negative bacteria, promoting the entry of aromatic ITCs into bacterial cytoplasm to facilitate bacterial clearance and thus preventing the development of bacterial resistance.

• MeSH
• antibakteriální látky * farmakologie   MeSH
• EDTA * farmakologie   MeSH
• gramnegativní bakterie * účinky léků   MeSH
• isothiokyanatany * farmakologie   MeSH
• mikrobiální testy citlivosti * MeSH
• mikrobiální viabilita účinky léků   MeSH
• mnohočetná bakteriální léková rezistence * účinky léků   MeSH
• permeabilita buněčné membrány účinky léků   MeSH
• synergismus léků MeSH
• vnější bakteriální membrána účinky léků   MeSH
• Publikační typ
• časopisecké články MeSH

The purpose of the present study was to study the synergy potential of gallic acid-based derivatives in combination with conventional antibiotics using multidrug resistant cultures of Escherichia coli. Gallic acid-based derivatives significantly reduced the MIC of tetracycline against multidrug resistant clinical isolate of E. coli. The best representative, 3-(3',4,'5'-trimethoxyphenyl)-4,5,6-trimethoxyindanone-1, an indanone derivative of gallic acid, was observed to inhibit ethidium bromide efflux and ATPase which was also supported by in silico docking. This derivative extended the post-antibiotic effect and decreased the mutation prevention concentration of tetracycline. This derivative in combination with TET was able to reduce the concentration of TNFα up to 18-fold in Swiss albino mice. This derivative was nontoxic and well tolerated up to 300 mg/kg dose in subacute oral toxicity study in mice. This is the first report of gallic acid-based indanone derivative as drug resistance reversal agent acting through ATP-dependent efflux pump inhibition.

• MeSH
• antibakteriální látky farmakologie   MeSH
• aplikace orální MeSH
• Escherichia coli účinky léků   MeSH
• indany aplikace a dávkování   škodlivé účinky   farmakologie   MeSH
• inhibitory enzymů farmakologie   MeSH
• kyselina gallová aplikace a dávkování   škodlivé účinky   farmakologie   MeSH
• makrofágy účinky léků   MeSH
• mikrobiální testy citlivosti MeSH
• modely nemocí na zvířatech MeSH
• myši MeSH
• nežádoucí účinky léčiv MeSH
• septický šok prevence a kontrola   MeSH
• simulace molekulového dockingu MeSH
• synergismus léků * MeSH
• tetracyklin farmakologie   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Vascularized composite allotransplantation (VCA) is an evolving field of reconstructive surgery that has revolutionized the treatment of patients with devastating injuries, including those with limb losses or facial disfigurement. The transplanted units are typically comprised of different tissue types, including skin, mucosa, blood and lymphatic vasculature, muscle, and bone. It is widely accepted that the antigenicity of some VCA components, such as skin, is particularly potent in eliciting a strong recipient rejection response following transplantation. The fine line between tolerance and rejection of the graft is orchestrated by different cell types, including both donor and recipient-derived lymphocytes, macrophages, and other immune and donor-derived tissue cells (e.g., endothelium). Here, we delineate the role of different cell and tissue types during VCA rejection. Rejection of VCA grafts and the necessity of life-long multidrug immunosuppression remains one of the major challenges in this field. This review sheds light on recent developments in decoding the cellular signature of graft rejection in VCA and how these may, ultimately, influence the clinical management of VCA patients by way of novel therapies that target specific cellular processes.

• MeSH
• homologní transplantace MeSH
• imunologická tolerance MeSH
• imunosupresivní léčba MeSH
• lidé MeSH
• rejekce štěpu MeSH
• vaskularizovaná kompozitní alotransplantace * škodlivé účinky   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

Prevalencia multirezistentnej tuberkulózy (multidrug-resistant tuberculosis – MDR-TB) a extenzívne rezistentnej tuberkulózy (extensively drug-resistant tuberculosis – XDR-TB) sa vo svete alarmujúcim tempom zvyšuje. Aktuálne programy "Boja proti tuberkulóze" sú v Ruskej federácii podporované štátnou vládou, regionálnymi vládami a tiež zdravotníckymi inštitúciami. Každý región tento krajiny má však vlastné špecifiká a vyžaduje si špecifické intervencie. Napriek tomu, že niektoré nové antituberkuloticky (anti-TB) pôsobiace liečivá (bedachilín, delamanid) boli už relevantnými inštitúciami schválené a iné sľubné zlúčeniny, najmä zo skupiny oxazolidinónov, sú v rôznych fázach klinických hodnotení prebiehajúcich vo svete, nájdenie efektívnych, bezpečných, farmakokineticky výhodných, ekonomicky a logisticky dostupných anti-TB-liečiv stále zostáva pre medicínske a farmaceutické vedy veľkou výzvou. Tiosemikarbazónové liečivo perchlozón bolo v Ruskej federácii schválené v roku 2012 pre liečbu (samostatne, alebo ako aktívna zložka komplexných liečebných režimov) HIV-1-negatívnych a tiež HIV -1-pozitívnych pacientov, ktorí sú postihnutí MDR-TB alebo XDR-TB. Mechanizmus anti-TB-účinku perchlozónu by mohol byť podobný tomu, akým pôsobí tiacetazón, ktorý patrí do identickej chemickej skupiny. Perchlozóm musí byť pravdepodobne aktivovaný mykobakteriálne kódovanou oxygenázou (EthA) na reaktívne entity. Tieto aktívne formy by mohli pôsobiť viacerými mechanizmami, vrátane inhibície syntézy bunkovej steny mykobaktérií (kvôli interferencii s procesom dehydratácie syntázy mastných kyselín typu II) alebo senzitizácie bunky Mycobacterium tuberculosis voči oxidačnému stresu. V rámci relevantných predklinických a klinických štúdií perchlozónu boli potvrdené jeho výhodné farmakokinetické vlastnosti a tiež tolerovateľnosť ľudským organizmom. Aktuálne predbežné zistenia in vivo (animálne modely) by však mohli indikovať genotoxicitu po subakútnej inhalácii tohto liečiva. Z uvedeného dôvodu je veľmi žiaduce uvažovať o ďalšom vývoji výhodnejších spôsobov podania perchlozónu, ktoré sú založené na nano- a mikročasticových systémoch. Tieto inovatívne alternatívy by potenciálne zlepšili cielené dodanie liečiva, jeho účinnosť a znížili (eliminovali) by aj eventuálnu toxicitu.

The prevalence of multidrug-resistant tuberculosis (MDR- -TB) and extensively drug-resistant tuberculosis (XDR- -TB) has been increasing at an alarming rate worldwide. Today's “Fight against Tuberculosis“ programmes in the Russian Federation are subsidized by state and regional governments as well as health authorities. Each region has its own specific characteristics and needs specific interventions. Although some novel anti-tuberculosis (anti-TB) drugs (bedaquiline, delamanid) were approved by relevant authorities, and some promising compounds, especially those of oxazolidinones, are in various phases of clinical trials worldwide, the finding of effective, safe, pharmacokinetically favorable, economically and logistically accessible anti-TB agents still remains a serious challenge for medical and pharmaceutical sciences. Perchlozone, a compound containing a thiosemicarbazone scaffold, was approved in the Russian Federation in 2012 for the treatment (alone or as the active component of complex treatment regimens) of HIV-1 negative as well as HIV-1 positive patients suffering from MDR-TB or XDR-TB. Mechanism of anti-TB action of perchlozone might be similar to that of thiacetazone, which belongs into the same chemical class. Perchlozone has to be probably activated into reactive species by a mycobacterially encoded monoxygenase (EthA). The activated forms might act in multiple ways, including inhibition of mycobacterial cell wall synthesis due to interfence with a dehydration step of the type II fatty acid synthase pathway or sensitization of the Mycobacterium tuberculosis cell to oxidative stress. Favorable toxicological properties of perchlozone and its tolerability by the human organism were confirmed within revevant preclinical and clinical studies. However, recent preliminary investigations in vivo (animal models) could indicate genotoxicity after subacute inhalation of the drug. Regarding this issue, further development of more convenient nano- or microparticle-based formulations of perchlozone potentially improving targeted delivering and efficiency as well as decreasing (eliminating) its eventual toxicity might be taken into strong consideration.

• Klíčová slova
• perchlozon,
• MeSH
• antituberkulotika * farmakologie   terapeutické užití   MeSH
• HIV infekce MeSH
• hodnocení léčiv MeSH
• lidé MeSH
• multirezistentní tuberkulóza * farmakoterapie   MeSH
• Mycobacterium tuberculosis účinky léků   MeSH
• Check Tag
• lidé MeSH

Conditions facilitating resistance to quaternary ammonium compounds (QACs) were investigated in Staphylococcus aureus SK982 exposed to benzalkonium chloride (BAC; a member of QACs) under various circumstances. S. aureus SK982 carrying the qacA gene encoding for resistance to QACs was grown in the presence of stable or gradually increasing concentrations of BAC, or it was exposed to this antiseptic in the exponential phase of growth. Bacteria cultivated in the highest BAC concentrations that did not retard their growth comparing to the untreated control were subjected to real-time quantitative polymerase chain reaction analysis for relative expression of the efflux genes qacA and norA. Under such conditions, S. aureus SK982 tolerated a relatively low stable concentration of BAC (1.22 mg/L) when compared with a gradually increasing antiseptic concentration (tolerance of 4.88 mg/L). However, in both cases, qacA expression was not significant. The culture exposed in the exponential phase of growth tolerated the highest concentration of BAC (9.76 mg/L) as also accompanied by significant overexpression of qacA. Expression of norA was relatively low regardless of the conditions tested. It seems that under the short-term conditions, the phase of bacterial growth is more important for the expression of BAC resistance than the capability to adapt to this antiseptic. This study provides a deeper insight into the relevance of the qac genes in conferring resistance to QACs.

• MeSH
• antibakteriální látky aplikace a dávkování   farmakologie   MeSH
• bakteriální léková rezistence genetika   MeSH
• bakteriální proteiny genetika   MeSH
• benzalkoniové sloučeniny aplikace a dávkování   farmakologie   MeSH
• kvantitativní polymerázová řetězová reakce MeSH
• membránové transportní proteiny genetika   MeSH
• mikrobiální testy citlivosti MeSH
• proteiny spojené s mnohočetnou rezistencí k lékům genetika   MeSH
• regulace genové exprese u bakterií MeSH
• Staphylococcus aureus účinky léků   genetika   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Special attention is required when pharmacological treatment is indicated for a pregnant woman. P-glycoprotein (MDR1) is a well-known transporter localized in the maternal blood-facing apical membrane of placental syncytiotrophoblast and is considered to play an important role in protecting the developing fetus. Maraviroc, a MDR1 substrate that is registered for treatment of HIV infection, shows a low toxicity profile, suggesting favorable tolerability also if administered to pregnant women. Nevertheless, there is only poor understanding to date regarding the extent to which it permeates across the placental barrier and what are the transport mechanisms involved. Endeavoring to clarify the passage of maraviroc across placenta, we used in this study the method of closed-circuit perfusion of maraviroc across human placental cotyledon. The data obtained confirmed slight involvement of MDR1, but they also suggest possible interaction with other transport system(s) working in the opposite direction from that of MDR1. Complementary in vitro studies, including cellular experiments on choriocarcinoma BeWo cells as well as transporter-overexpressing MDCKII and A431 cell lines and accumulation in placental fresh villous fragments, revealed maraviroc transport by MRP1, OATP1A2, and OATP1B3 transporters. Based on mRNA expression data in the placental tissue, isolated trophoblasts, and fetal endothelial cells, especially MRP1 and OATP1A2 seem to play a crucial role in cooperatively driving maraviroc into placental tissue. By the example of maraviroc, we show here the important interplay of transporters in placental drug handling and its possibility to overcome the MDR1-mediated efflux.

• MeSH
• akridiny farmakologie   MeSH
• buňky MDCK MeSH
• látky proti HIV krev   metabolismus   farmakologie   MeSH
• lékové interakce MeSH
• lidé MeSH
• maravirok krev   metabolismus   MeSH
• nádorové buněčné linie MeSH
• P-glykoproteiny antagonisté a inhibitory   genetika   metabolismus   MeSH
• perfuze MeSH
• placenta účinky léků   metabolismus   MeSH
• placentární oběh MeSH
• přenašeče organických aniontů antagonisté a inhibitory   genetika   metabolismus   MeSH
• protein OATP1B3 antagonisté a inhibitory   genetika   metabolismus   MeSH
• proteiny spojené s mnohočetnou rezistencí k lékům genetika   metabolismus   MeSH
• psi MeSH
• regulace genové exprese MeSH
• ritonavir farmakologie   MeSH
• těhotenství MeSH
• tetrahydroisochinoliny farmakologie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• psi MeSH
• těhotenství MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

The genetic basis for phenicol resistance was examined in 38 phenicol-resistant clinical Escherichia coli isolates from poultry. Out of 62 isolates, 38 showed resistance for chloramphenicol and nine for florfenicol, respectively. Each strain also demonstrated resistance to a variety of other antibiotics. Molecular detection revealed that the incidence rates of the cat1, cat2, flo, flo-R, cmlA, and cmlB were 32, 29, 18, 13, 0, and 0%, respectively. Nineteen strains were tolerant to organic solvents. PCR amplification of the complete acrR (regulator/repressor) gene of five isolates revealed the amino acid changes in four isolates. DNA sequencing showed the non-synonymous mutations which change the amino acid, silent mutation, and nucleotide deletion in four isolates. MY09C10 showed neither deletion nor mutation in nucleotide. The AcrA protein of the AcrAB multidrug efflux pump was overexpressed in these strains. Complementation with a plasmid-borne wild-type acrR gene reduced the expression level of AcrA protein in the mutants and partially restored antibiotic susceptibility one- to fourfold. This study shows that mutations in acrR are an additional genetic basis for phenicol resistance.

• MeSH
• antibakteriální látky farmakologie   MeSH
• bakteriální geny genetika   MeSH
• DNA bakterií genetika   MeSH
• Escherichia coli účinky léků   genetika   izolace a purifikace   MeSH
• genotyp MeSH
• kur domácí MeSH
• membránové transportní proteiny genetika   MeSH
• mikrobiální testy citlivosti veterinární   MeSH
• mnohočetná bakteriální léková rezistence účinky léků   genetika   MeSH
• mutace MeSH
• nemoci drůbeže mikrobiologie   MeSH
• proteiny z Escherichia coli genetika   MeSH
• regulace genové exprese u bakterií MeSH
• represorové proteiny genetika   MeSH
• rezistence na chloramfenikol účinky léků   genetika   MeSH
• testy genetické komplementace veterinární   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH