Genome Instability and Bleomicin Sensitivity Test

Procjena individualne osjetljivosti na mutagene često je dio istraživanja u epidemiološkim studijama koje prate pojavnost zloćudnih bolesti u populacijama. Posljedica djelovanja mutagena u genomu izloženih osoba jest nastanak određene, manje ili veće, količine oštećenja, uvjetovane individualnim razlikama u osjetljivosti. Viša razina takve genomske nestabilnosti znači opasnost (rizik) od razvoja zloćudnih bolesti. Interindividualne razlike u odgovoru na mutagene obično se povezuju i s promijenjenom (većinom smanjenom) sposobnosti (kapacitetom) za popravak DNA. Citogenetičke studije su pokazale da je genom tumorskih stanica nestabilniji od normalnih, a time i skloniji akumuliranju oštećenja, bilo da je nestabilnost uzrokovana nasljeđem, izloženošću ili kombinacijom tih dvaju učinaka. U oboljelih ispitanika utvrđena je povećana učestalost kromatidnih i kromosomskih aberacija naspram normalne populacije te sklonost razvoju određenih vrsta neoplazija. U praćenju povezanosti promijenjenog odgovora i pojavnosti tumora služe nam različiti biomarkeri. Kao indirektni pokazatelji uspješnosti popravka DNA često se rabe testovi osjetljivosti na mutagene u kulturama limfocita periferne krvi. Jedan od takvih testova je i bleomicinski test. Radiomimetik i citostatik, a po strukturi glikopeptid, bleomicin se u stanici prevodi u aktivni oblik sposoban cijepati molekulu DNA što uzrokuje brojne jednolančane i dvolančane lomove. Kao jednostavna i jeftina metoda, zasniva se na utvrđivanju ukupnog broja jednolančanih lomova u kromosomima limfocita uzgajanih u staničnoj kulturi koji su u uvjetima in vitro tijekom kasne G2-faze staničnog ciklusa bili izloženi bleomicinu. Ovaj revijalni rad daje pregled utjecaja raznih faktora na rezultate samog testa i pokazuje njegovu široku primjenu u proučavanju genomske nestabilnosti koju najčešće uzrokuje kombinacija raznih faktora.Estimation of individual susceptibility to mutagens is often a part of epidemiological studies monitoring the appearance of malignant disease in different populations. Genome exposure to mutagens can lead to DNA damage. The rate of damage depends on individual differences in response, which are usually associated with differences in DNA repair capacity. Cytogenetic studies have shown that the genome of tumour cells is less stable than normal cells and therefore accumulates more damage. Tumour patients show a higher frequency of chromatid and chromosomal aberrations and a predisposition to certain types of tumours. One of the common biomarkers used in monitoring tumour appearance and changed response to DNA damage is the bleomycin test. In its active form, bleomycin (glycopeptid) is a radiomimetic cytostatic that can damage the DNA molecule and cause multiple single and double strands. The bleomycin test is simple and inexpensive, and is based on scoring chromatid breaks in lymphocytes in vitro exposed to bleomycin during the late G2 phase of the cell cycle. This review looks into different factors that may affect test results and discusses its wide implementation in studies of genome instability usually caused by a combination of factors

Correction of the acid-base balance in the presence of the hypoxic-ischemic brain damage in newborns

One of the current problems of perinatal neurology is the hypoxic-ischemic brain damage in newborns associated with the influence of the hypoxia upon the fetus, intranatal and postnatal asphyxia on one hand and a lack of the efficient therapy schemes on the other hand. Due to this, the purpose of this pilotstudy isto identify the effects of drug Cytoflavin, included into the complex therapy scheme for the newborns with the cerebral ischemia of II-III stages, on the blood acid-base balance. A retrospective analysis of the results of the complex therapy for 16 newborns with the moderate (14 children) and severe (2 children) brain ischemia was performed. Cytoflavin was included in the standard therapy schemes for all children at a dose of 2 ml/kg per day at a dilution of 5% glucose solution at the ratio of 1:5, intravenously, microfluidically for 20 hours for 3 days. In addition to the standard examination, the blood acid-base balance assessment using the follow-up microgasometric method was included (after 60 min and then every 6 hours until 72 hours of observation). All children had positive tendency to the arresting of the metabolic acidosis (in the form of the decrease of the base deficiency after 24 hours and increase of pH level (the level of 7.30 was reached by 12 hours of age in full-term newborns and 24 hour of age in the preterm newborns). The revealed positive changes in the time of the metabolic acidosis arresting along with the small volumes of the infusion and good tolerability are the cause for the planning of the subsequent, more large-scale studies

Novel BODIPY Conjugates with Myrtenol: Design, Spectral Characteristics, and Possibilities for Practical Application

The synthesis of new fluorescent probes, based on biocompatible luminophors and exhibiting various specificities, is intensively developed worldwide. Many luminophors contain a hydrophobic group that limits their application for cell staining under vital conditions. Herein, we report the synthesis of two BODIPY molecules—BF2-meso-(4-butan/pentanamido-N-(((1S,5R)-6,6-dimethylbicyclo [3.1.1]hept-2-en-2-yl)methyl)-N,N-dimethylpropan-1-aminium)-3,3′,5,5′-tetramethyl-2,2′-dipyrromethene bromides—designed as 10, 11 with a spacer of either four or three CH2 groups in length, respectively. These molecules present conjugates of BODIPY luminophors with (+)-myrtenol via a quaternary ammonium group. Both terpene-BODIPY conjugates demonstrated high fluorescence efficiency in various solvents such as OctOH, DMSO and water, and were characterized by their stability at pH 1.65–9.18. The fusion of the myrtenol, a monocyclic terpene, to the BODIPY fluorophore in the meso-substituent facilitated their penetration into the filamentous fungi Fusarium solani, while impairing the binding of the latter with S. aureus, K. pneumoniae and P. aeruginosa. The additional quaternary ammonium group between the myrtenol and fluorophore moieties restored the bacterial cell-staining while it did not affect the staining of fungi. Finally, the BODIPY conjugate 11 was able to stain both Gram-positive and Gram-negative bacteria by its interaction with their cell wall (or the membrane), as well as penetrating into filamentous fungi F. solani and staining their mitochondria

Increasing the Efficacy of Treatment of <i>Staphylococcus aureus</i>–<i>Candida albicans</i> Mixed Infections with Myrtenol

Infectious diseases caused by various nosocomial microorganisms affect worldwide both immunocompromised and relatively healthy persons. Bacteria and fungi have different tools to evade antimicrobials, such as hydrolysis damaging the drug, efflux systems, and the formation of biofilm that significantly complicates the treatment of the infection. Here, we show that myrtenol potentiates the antimicrobial and biofilm-preventing activity of conventional drugs against S. aureus and C. albicans mono- and dual-species cultures. In our study, the two optical isomers, (−)-myrtenol and (+)-myrtenol, have been tested as either antibacterials, antifungals, or enhancers of conventional drugs. (+)-Myrtenol demonstrated a synergistic effect with amikacin, fluconazole, and benzalkonium chloride on 64–81% of the clinical isolates of S. aureus and C. albicans, including MRSA and fluconazole-resistant fungi, while (−)-myrtenol increased the properties of amikacin and fluconazole to repress biofilm formation in half of the S. aureus and C. albicans isolates. Furthermore, myrtenol was able to potentiate benzalkonium chloride up to sixteen-fold against planktonic cells in an S. aureus–C. albicans mixed culture and repressed the adhesion of S. aureus. The mechanism of both (−)-myrtenol and (+)-myrtenol synergy with conventional drugs was apparently driven by membrane damage since the treatment with both terpenes led to a significant drop in membrane potential similar to the action of benzalkonium chloride. Thus, due to the low toxicity of myrtenol, it seems to be a promising agent to increase the efficiency of the treatment of infections caused by bacteria and be fungi of the genus Candida as well as mixed fungal–bacterial infections, including resistant strains

<i>N</i>-(((1<i>S</i>,5<i>R</i>)-6,6-Dimethylbicyclo[3.1.1]hept-2-en-2-yl)methyl)-3-dodecan/tetradecanamido-<i>N</i>,<i>N</i>-dimethylpropan-1-aminium Bromide

The syntheses of the title compounds were performed using lauric and myristic acids. The compounds obtained were characterized using 1H-, 13C-NMR and 2D 1H-1H COSY, 1H-13C HSQC NMR, IR, and high-resolution mass spectrometry. Both compounds exhibited bactericidal activity on S. aureus comparable to that of a reference drug (miramistin). Compound 10, with lauric acid fragment, had a 16-fold higher activity on P. aeruginosa compared to compound 11, which in turn contains myristic acid fragment (with minimum inhibitory concentrations of 32 and 512 μg/mL, respectively). Compound 11 exhibited a pronounced activity against all types of fungi (higher than the activity of miramistin), while the activity of compound 10 was considerably lower. Thus, compound 11 can serve as a promising antimicrobial agent for the treatment of various fungal and staphylococcal infections, while compound 10 is of interest to treat P. aeruginosa-associated infections