Search results for "IBA"

New potent antibacterials against Gram-positive multiresistant pathogens: effects of side chain modification and chirality in linezolid-like 1,2,4-ox…

2014

The effects of side chain modification and chirality in linezolid-like 1,2,4-oxadiazoles have been studied to design new potent antibacterials against Gram-positive multidrug-resistant pathogens. The adopted strategy involved a molecular modelling approach, the synthesis and biological evaluation of new designed compounds, enantiomers separation and absolute configuration assignment. Experimental determination of the antibacterial activity of the designed (S)-1-((3-(4-(3-methyl-1,2,4-oxadiazol-5- yl)phenyl)-oxazolidin-2-one-5-yl)methyl)-3-methylthiourea and (S)-1-((3-(3-fluoro-4-(3-methyl-1,2,4- oxadiazol-5-yl)phenyl)-oxazolidin-2-one-5-yl)methyl)-3-methylthiourea against multidrug resistan…

Effect of Ribavirin on the Mutation Rate and Spectrum of Hepatitis C Virus In Vivo

2009

ABSTRACTTheir extremely error-prone replication makes RNA viruses targets for lethal mutagenesis. In the case of hepatitis C virus (HCV), the standard treatment includes ribavirin, a base analog with an in vitro mutagenic effect, but the in vivo mode of action of ribavirin remains poorly understood. Here, we test the mutagenic effects of ribavirin plus interferon treatment in vivo using a new method to estimate mutation rates based on the analysis of nonsense mutations. We apply this methodology to a large HCV sequence database containing over 15,000 reverse transcription-PCR molecular clone sequences from 74 patients infected with HCV. We obtained an estimate of the spontaneous mutation ra…

Interferon-alpha inhibits hepatitis C virus subgenomic RNA replication by an MxA-independent pathway.

2001

Hepatitis C virus (HCV) persists in the majority of infected individuals and is a major cause of chronic hepatitis, liver cirrhosis and hepatocellular carcinoma. Chronic hepatitis C is currently treated with interferon (IFN)-α or with a combination of IFN-α and ribavirin. The availability of an HCV replicon system (Lohmann et al., Science 285, 110–113, 1999) allowed the investigation of the effects of IFN on genuine HCV replication in cultured cells. It is shown here that IFN-α inhibits subgenomic HCV RNA replication in HuH-7 human hepatoma cells. Immunofluorescence, Western blot and Northern blot analysis revealed that levels of both HCV protein and replicon RNA were reduced after treatme…

Photosynthesized silver-polyaminocyclodextrin nanocomposites as promising antibacterial agents with improved activity

2016

Ag nanocomposites were prepared by photoreduction of ammoniacal silver acetate in the presence of poly-{6-[3-(2-(3-aminopropylamino)ethylamino)propylamino]}-(6-deoxy)-β-CD (amCD). The obtained systems were characterized by means of various complementary techniques (UV-vis, FT-IR, TEM, SAED). In particular, FT-IR spectroscopy evidenced a partial oxidative degradation of the polyamine branches of the capping auxiliary, due to the fact that these groups function as a sacrificial reducing agent in the photoinduced formation of the Ag metal core. TEM and SAED micrographs showed that the Ag cores possess a relatively low polydispersity and a significantly crystalline character. The Ag–amCD system…

PROPERTIES AND APPLICATIONS OF POLYAMINOCYCLODEXTRIN DERIVATIVES

Nel presente lavoro sono state prese in esame le potenziali applicazioni delle poliamminociclodestrine. In particolare, diversi derivati poliamminociclodestrinici (amCD) sono stati ottenuti utilizzando un approccio sintetico diretto, tramite reazione di sostituzione nucleofila tra la heptakis-(6-deossi)-(6-bromo)-βCD (BrβCD) e poliammine lineari. Una volta effettuata l’opportuna caratterizzazione NMR, ESI-MS e potenziometrica, sono state investigate diverse possibili utilizzazioni di tali materiali. Anzitutto, sono state valutate le capacità di dare complessi di inclusione host-guest con diversi derivati organici sia delle amCD libere che di materiali costituiti da nanospugne a base di amCD…

Induction of ambuic acid derivatives by the endophytic fungus Pestalotiopsis lespedezae through an OSMAC approach

2021

Abstract Ten new ambuic acid derivatives, pestallic acids H–Q including one new iodinated natural product along with two known compounds, ambuic acid and ambuic acid 18-acetate, were obtained through fermentation of the endophytic fungus Pestalotiopsis lespedezae on solid rice medium with 3.5% NaI. Pestallic acids H–Q were undetectable in cultures of the fungus grown on solid rice medium lacking NaI or in those where NaI had been replaced by NaCl or NaBr. The structures of the new metabolites were established on basis of 1D/2D NMR and HRESIMS data. Their absolute configurations were determined by Mosher’s method and TDDFT-ECD calculations. The compounds failed to show antibacterial activity…

Nekrotizējošā fascīta izraisošo mikroorganismu un antibakteriālās terapijas vērtēšana

2018

Nekrotizējošais fascīts ir nekrotizējoša mīksto audu infekcija ar ļoti augstu letalitāti, par darba mērķi tika izvirzīts noskaidrot un izvērtēt kāda ir biežāk pielietotā empīriskā antibakteriālā terapija un biežāko baktēriju floru nekrotizējošā fascīta gadījumā Rīgas Austrumu klīniskās universitātes slimnīcas stacionārā „Gaiļezers” un „Biķernieki” laika posmā no 2008. gada līdz 2018.gadam. Darba teorētiskajā daļā tiek analizēta zinātniskā literatūra par diagnozi - nekrotizējošais fascītus, tā cēloņiem un riskiem, diagnostiku kā arī ārstēšanas principiem. Darbā apkopoti jaunāko publikāciju dati par diagnozes veidojošajiem un to noteicošajiem faktoriem. Diplomdarba mērķis: Retrospektīvā pētīj…

Antibacterial and antioxidant activities in Sideritis italica (Miller) Greuter et Burdet essential oils

2006

Sideritis italica (Miller) Greuter et Burdet is a widespread Lamiacea in the Mediterranean region used in traditional medicine. Essential oils were antibacterial against nine ATCC and as many clinically isolated Gram-positive and Gram-negative bacterial strains. Antibacterial activity was also found against Helicobacter pylori: a dose-dependant inhibition was shown between 5 and 25 microg/ml. The antibacterial activity of the oils was expressed as MICs (minimum inhibitory concentrations) and MBCs (minimum bactericidal concentrations). At a concentration between 3.9 and 250 microg/ml the oils showed a significant antibacterial effect against both Gram-negative and Gram-positive bacteria. In …

Large scale motions in models of human nicotinic receptors

2014

Faktiskā kļūda

2017

Bakalaura darba tēma ir “Faktiskā kļūda”. Faktiskā kļūda tradicionāli ir viens no diviem kļūdas institūta veidiem. Latvijas krimināltiesībās kļūdas institūtam nav normatīvais regulējums, kā rezultātā tās saturs tiek atklāts krimināltiesību teorijā. Izvēlētā bakalaura darba tēma ir aktuāla, jo faktiskā kļūda ietekmē personas psihiskās attieksmes veidošanos pret noziedzīgā nodarījuma objektīvajām pazīmēm. Bakalaura darba tēmas ietvaros autore, aplūkojot ārzemju un Latvijas krimināltiesību teorijas nostādnes, izteiks savus secinājumus saistībā ar faktiskās kļūdas saturu un izpratni, kā arī piedāvās piemērus nestandarta faktiskās kļūdas gadījumiem. Atslēgvārdi: Faktiskā kļūda, nodoms, vaina, ap…