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The use of nanoparticles (NPs) and research on antimicrobial activity is increasing. The use of NPs in catheters, on medical textiles and other surfaces in the healthcare settings is still a challenge because the non-specific nature of the antibacterial effect is different from known antimicrobial agents and biocides.

antimicrobial polymers, nanoparticles, development, platinum

Increased levels of copper are considered as contributing factor in the progression of neurodegenerative diseases by promoting oxidative stress conditions. The aim of our study was to examine effects of ethanolic extract of propolis (EEP) against copper-induced death in cultured P19 neuronal cells. Propolis is a heterogeneous resinous product collected by honey-bees. Due to its well documented health beneficial effects, including antioxidative and neuroprotective, propolis and its extracts are widely used in traditional and modern medicine. Surprisingly, we found that small, per se non-toxic concentrations of EEP exacerbated copper-induced death of P19 neurons. The neurotoxic effect of small concentrations of EEP was particularly pronounced in severe oxidative stress. In the presence of excess copper EEP increased production of reactive oxygen species (ROS) and stimulated caspase-3/7 activity. EEP also promoted copper-induced increase in the expression of transcription factor p53 and its downstream target Bax. The detrimental effects of EEP were accompanied with a prominent up-regulation of glyceraldehyde 3-phosphate dehydrogenase (GAPDH), a metabolic enzyme that may sense oxidative stress and participate in cell death events. SB203580, an inhibitor of p38 mitogen-activated protein kinase (MAPK) completely prevented toxic effects of EEP in severe oxidative stress conditions, whereas SP600125, an inhibitor of c-Jun N-terminal kinase (JNK), demonstrated a significant pro-death effect. Our data indicates a pro-oxidative and apoptotic mode of EEP action in the presence of excess copper, and suggest an important role of ROS/p53/p38 crosstalk in death cascade. Although propolis is considered as a safe natural remedy, the obtained results pointed out that caution is required during its prolonged consumption in certain medical conditions. Our study also emphasized that detailed pharmacological and toxicological studies must be carried out for propolis and other natural dietary supplements in order to identify the entire repertoire of their undesirable side-effects.

Here we report the evaluation of biofilm formation inhibition by primaquine and halogenaniline fumardiamides.

Introduction: Excitotoxicity is a form of neuronal death induced by increased glutamate signaling. It is involved in ischemia-induced brain damage, traumatic brain injury and various neurodegenerative diseases. Prolonged activation of ionotropic glutamate receptors results in substantial calcium overload that ends in oxidative stress-related apoptotic death. We studied neuroprotective potential of zolpidem, a drug that posses structural similarity to antioxidant melatonin and exerts its central effects acting at GABAA receptor complex. Materials and methods: Effects of zolpidem were studied in the culture of P19 neurons. Neuronal death was induced by exposure to 300 microM glutamate for 3 hours. 24 h later we monitored changes in neuronal viability, generation of reactive oxygen species (ROS) and caspase-3/7 activity. Protein expression of transcription factor p53 and phosphorylated Akt was determined by western blot method, whereas gene expression analysis of Bax, Bcl-2 and p53 was assessed by the semiquantitative RT-PCR method. Results: Zolpidem prevented glutamate-induced neuronal death. It attenuated enhancement of ROS generation, increase in p53 and Bax expression and caspase-3/7 activity, and induced prominent over-activation of Akt kinase. The pro-survival effect and pAkt induction were prevented in the presence of wortmannin, an inhibitor of phosphatidylinositol-3-kinase (PI3K). Interestingly, flumazenil, a GABAA receptor antagonist, did not affect zolpidem-mediated neuroprotection, whereas PK11195, a drug that modulates mitochondrial translocator protein 18 kDa (TSPO) and F0F1-ATPase, prevented effect of zolpidem. Conclusion: The obtained results suggest promising therapeutic potential of zolpidem against excitotoxic insults and highlight importance of mitochondria and Akt signalling as valuable therapeutic targets against glutamate-mediated neurodegeneration.

After proper sanitation of apiary with clinical visable outbreak, the disinfection of beekeeping beekeeping equipment and enviromnent is crucuial preventive masure of disease reappearance. As general chemical disinfectants are often recommended, the aim of this work was to analyse efficacy of commercial disinfectants Sekusept Aktiv and Incidin Oxy Wipe S.

Nosema disease is a parasitic disease of adult honeybees caused by microsporidia from the genus Nosema. It has detrimental effects on strength, productivity and immune suppression of honeybee colonies, so an appropriate control of this disease is advisable. Effective microorganisms are combinations of numerous species of useful microbes, which are widely used in different fields. As a novel approach in therapy, we hypothesize the EM® PROBIOTIC for beekeeping usage could play an important role in suppression of Nosema spp. invasion and in stimulating synthesis of vitellogenin which has impact in immunological responses and pathogen defense at both, the individual and honeybee colony level. The aim of this study was to determine the influence of additional feeding of honeybee colonies with the EM® PROBIOTIC for beekeeping usage on the previously mentioned parameters. Honeybee colonies fed probiotic were given sugar solution, with three different dilutions (2.5% ; 5% ; 10%) of commercial probiotic called EM® PROBIOTIC FOR BEES. Sampling of workers hemolymph was performed 13th and 22nd day after initial feeding. The number of Nosema spp. spores was determined by counting spores using Malassez hemocytometer and concentrations of vitellogenin in hemolymph samples were determined by MyBioSource elisa kit using spectrophotometer. Results showed that concentrations of vitellogenin were increased and significantly different (p

SAHAquines represent hybrid drugs, developed as a combination of SAHA, an anticancer drug with weak antiplasmodial activity, and an antiplasmodial agent bearing 8-aminoquinoline or 4-aminoquinoline motifs with low anticancer activity, i.e. primaquine (PQ), chloroquine (CQ) or mefloquine (MQ). Two generations of SAHAquines were designed, prepared and biologically evaluated. In the 1st generation SAHA motif was combined with PQ. The designed hybrid drugs differ in linker length/type and/or functional groups: compounds 1 are esters, 2 are carboxylic acids, 4 are unsubstituted and 3 and 5 are O-benzyl and O- methyl substituted hydroxamic acids. 2nd generation of SAHAquines, fumaric acid diamides 6−8 were designed as Michael acceptors. One of the amide bonds was achieved with a terminal amino group of PQ, CQ or MQ, while the other amide bond was realized with halogen anilines. To fully explore the biological potential of SAHAquines, an extensive screening was performed: antiproliferative (a panel of cancer cell lines), antiplasmodial (both erythrocytic and hepatic stages), antibacterial (G(+) and G(−) bacteria and several Mycobacterium species) and antiviral (a series of DNA and RNA viruses) activity was evaluated. So far, results have shown that SAHAquines of the 1st generation exert antiproliferative and antiplasmodial activity on both erythrocytic and hepatic stages, while the 2nd generation SAHAquines exhibit significant biofilm eradication capacity. Further testing is in progress.

Copper is an essential transition metal with multiple cellular functions mainly related to diverse types of oxidation and reduction reactions. Although mechanisms of copper storage and availability are tightly regulated, some factors, such as occupational hazard, environmental contamination and inborn errors of Cu metabolism, may overwhelm intracellular storage capacity, leading to copper accumulation and undesirable cellular effects. Deregulation of copper homeostasis is recognized as an important factor in the etiology of a number of devastating neurodegenerative disorders, including Alzheimer's disease, Parkinson's disease and amyotrophic lateral sclerosis. The aim of the present study was to investigate potential neuroprotective effects of flavonoid quercetin, one of the most potent scavengers of reactive oxygen species (ROS), against copper-induced toxicity and to elucidate mechanisms of its action at the molecular and cellular level in the culture of differentiated P19 neurons. P19 neurons were obtained by the differentiation procedure from the P19 mouse embryonal carcinoma cells in the presence of retinoic acid, and were exposed to quercetin and copper for 24 h. Survival of P19 neurons in the presence of copper, quercetin and inhibitors of signalling pathways was determined by the colorimetric 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide (MTT) assay. ROS accumulation was measured by the assay that utilizes the cell permeable substrate, 2’, 7’- dichlorofluorescin diacetate. Changes in the nuclear condensation that are characteristic for the programmed type of cell death were assessed by Hoechst staining. Measurement of the activities of key apoptotic markers caspase-3 and -7 was performed with Apo-ONE® Homogeneous Caspase-3/7 Assay (Promega). Copper- and quercetin-induced changes in the protein expression were determined by the Western blot method. In a dose-dependent manner, a concomitant treatment with quercetin improved viability of moderately-injured P19 neurons exposed to 0.5 mM CuSO4 for 24 h. Quercetin decreased ROS formation and prevented caspase-3/7 activation and chromatin condensation. Neuroprotective effects of quercetin were pharmacologically prevented by the inhibition of ERK1/2 and phosphoinositide 3-kinase/Akt signalling by exposure to UO126 and wortmannin, respectively. Preliminary results indicate that treatment with copper and quercetin also affected expression of transcription factor p53 at the protein level. In neurons that were more severely damaged by exposure to 1 mM CuSO4, quercetin exerted strong pro-oxidative action and further exacerbated cytotoxic effects. Quercetin exerted beneficial and desirable pro-survival effects in moderately injured neurons by affecting intracellular signalling pathways and attenuating ROS production, but was also able to enhance pro-oxidative copper-effects with detrimental biological consequences at higher copper concentrations. As herbal formulations are nowadays widely used in the prevention and therapy of oxidative-stress driven neuronal injuries, observed findings indicate that caution is required about taking dietary antioaxidative supplements and also for the future development of novel therapeutic drugs that are based on the structural backbone of the natural polyphenolic compounds.

Recently we have described preparation [1] and evaluation of antiproliferative [2], antioxidative [2] and antimalarial activity [3] of novel amino acid-primaquine ureidoamides 1a-f. In order to further investigate their biological activity, we found it worth to test their antimicrobial effects against a panel of Gram-positive, Gram-negative bacteria and fungal species. The title compounds showed very weak antimicrobial activity, with the exception of compounds 1a and 1d which exhibited moderate activity against some bacterial species. However, we have also tested the efficacy of compounds 1a-e on the biofilm formation by different bacterial and yeast strains. The results, expressed as minimum biofilm eradication concentration (MBEC), showed that the potency against biofilm formed by Escherichia coli ATCC 8739 and ATCC 10536 of all tested compounds was rather prominent, with even lower MBEC than that of the referent antibiotic gentamycin (MBEC = 25 µg/mL), especially for compounds 1a and 1c (MBEC = 6.25 µg/mL). The same compounds were also very potent as inhibitors of biofilm formed by Pseudomonas aeruginosa ATCC 27853, and somewhat less potent against P. aeruginosa ATCC 9027. Compound 1a had MBEC for S. aureus ATCC 6538 comparable with MBEC of gentamycin. On the other hand, none of the tested ureidoamides was effective against biofilm formation by Enterococcus faecalis. MBECs of almost all tested compounds against biofilm formed by Candida albicans ATCC 10231 and ATCC 90028 was at the level of referent antimicotic amphotericin, especially for the latter strain. The highest activity against biofilm formation by C. kefyr showed compounds 1d, 1e and 1f (MBEC = 25, 6.25 and 6.25 µg/mL, respectively). However, it has been found that the compounds are not effective against biofilm formation by C. parapsylosis ATCC 22019, C. tropicalis ATCC 750 and C. krusei ATCC 14243. Having in mind all the above mentioned facts, the tested ureidoamides 1a-f could serve as lead compounds in the development of novel inhibitors of biofilm formation.

Excitotoxicity is the pathological process in which neurons are damaged by excessive glutamate spillover, the major fast excitatory neurotransmitter in the mammalian central nervous system, and consequent prolonged stimulation of N-methyl-D-aspartate (NMDA) glutamate receptors. Excitotoxicity-related neuronal degeneration contributes to ischemia-induced brain damage, traumatic brain injury, epilepsy, and various chronic neurodegenerative diseases such as Parkinson's and Alzheimer's disease. Although intracellular pathways responsible for the glutamate-induced neuronal death are not completely understood, it is known that glutamate enhances accumulation of reactive oxygen species (ROS) and induces oxidative stress. The aim of our study was to investigate a potential neuroprotective effect of zolpidem, a drug that acts via GABAA receptor complex and possess structural analogy with melatonin, an endogenous compound with antioxidative properties, against glutamate-induced toxicity in the culture of differentiated P19 neurons that express both GABAA and NMDA receptors. P19 neurons were obtained from the mouse embryonal carcinoma cells in the presence of retinoic acid. They were exposed to glutamate (300 µM, 3 hours) and then to zolpidem (10 µM, 2 hours). 24 hours later, the survival of P19 neurons was determined by the colorimetric 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide (MTT) method and trypan blue assay. ROS accumulation was measured by the assay that utilizes the cell permeable substrate, 2’, 7’- dichlorofluorescin diacetate. Effect on plasma membrane integrity was determined by CytoTox-ONETM Homogeneous Membrane Integrity Assay (Promega). Changes in the nuclear condensation that are characteristic for the programmed type of cell death were assessed by Hoechst staining. Measurement of the activities of key apoptotic markers caspase-3 and -7 was performed with Apo-ONE® Homogeneous Caspase-3/7 Assay (Promega). Glutamate- and zolpidem-induced changes in the protein expression of transcription factor p53 and activated (phosphorylated) Akt were determined by the Western blot method, while changes in the expression of apoptosis-related genes (Bax, Bcl-2, p53 and fos) were monitored by the semiquantitative RT-PCR method. Zolpidem post-treatment diminished glutamate-induced decrease in viability of P19 neurons. Although zolpidem prevented glutamate-induced ROS increase, it failed to prevent neuronal death induced by exposure to hydrogen peroxide and excess copper ions that trigger much higher accumulation of ROS, thus indicating that neuroprotective effect of zolpidem against glutamate toxicity was not achieved solely by direct antioxidant activity. Zolpidem also prevented induction of caspase-independent programmed cell death, as well as the glutamate-induced p53 and Bax increase at the transcriptional and translational level. The neuroprotective effect of zolpidem was prevented in the presence of 100 nM wortmannin, an inhibitor of phosphoinositide 3-kinase (PI3K)/Akt signalling pathway. The obtained results indicate that neuroprotective effect of zolpidem against glutamate-induced neuronal injury is predominantly achieved via PI3K/Akt signalling. Although further studies are required to better elucidate mechanisms of neuroprotective action of zolpidem at the cellular and molecular level, the presented findings are promising regarding the potential use of zolpidem in the reduction of excitotoxicity-related neuronal dysfunction and degeneration.

Infekcije povezane sa zdravstvenom skrbi predstavljaju problem za sigurnost bolesnika. Čiste ruke su najznačajniji činitelj koji može smanjiti pojavnost infekcija povezanih sa zdravstvenom skrbi. Cilj istraživanja bio je utvrditi postoji li razlika u suradljivosti pri higijeni ruku zdravstvenih djelatnika prije i nakon edukacije. Istraživanjem su obuhvaćene medicinske sestre, fizioterapeuti i laboranti. Opservirani su postupci higijene ruku prema mjerama pravilne higijene ruku Svjetske zdravstvene organizacije. Za utvrđivanje razlika među proporcijama između dvaju nezavisnih uzoraka rabio se Fisherov egzaktni test. Nakon edukacije značajno je viša (P < 0.001) suradljivost u higijeni ruku. Značajno više laboranata provodi higijenu ruku (P = 0.046) nakon edukacije. Provedena edukacija je značajno utjecala na povećanje suradljivosti u higijeni ruku.

In the thematic issue edited the prominent authors bring novel knowledge on GABAergic system functions and give the overview of several GABA-related therapeutic options with intention to discuss evidence on the therapeutic potential and the rationale of novel GABAergic treatment of several disorders only recently connected, among others, to the abnormal function of GABAergic neurotransmission. Namely, the early clinical studies or pre-clinical evidences suggest that a promising GABAergic strategy could be developed since GABA targeting could reduce the symptoms associated with several diseases whose symptoms were recently attributed to the imbalanced inhibitory/excitatory GABA signal.

Hypnotic zolpidem produces its effects via the benzodiazepine binding site in α1-containing GABAA receptors. The aim of the study was to assess the influence of duration of zolpidem treatment and its withdrawal, as well as the role of alpha1-containing GABAA receptors in the development of physical dependence and tolerance. Namely, recombinant receptors can be used to characterize mechanisms involved in different processes in the brain and to delineate the contribution of specific receptor subtypes. To address the influence of chronic zolpidem treatment we exposed HEK293 cells stably expressing alpha1beta2gamma2S recombinant GABAA receptors for seven consecutive days, while withdrawal periods lasted for 24, 48, 72 and 96 hours. Using radioligand binding studies we determined that chronic zolpidem treatment did not induce changes in either GABAA receptor number or in the expression of subunit mRNAs. We observed the enhancement of binding sites and upregulated expression of subunit mRNAs only following 96-hour withdrawal. Moreover, zolpidem treatment and its withdrawal (All time points) induced functional uncoupling between GABA and benzodiazepine binding sites in the GABAA receptor complex. Accordingly, it might be assumed that zolpidem withdrawal-induced uncoupling of GABAA receptors is associated with altered GABAA receptor subunit mRNA expression. The results presented here provide an insight into molecular and cellular mechanisms probably underlying adaptive changes of GABAA receptor function in response to chronic usage and withdrawal of zolpidem and perhaps the observed molecular changes could be linked to the tolerance and dependence produced upon prolonged treatment with other GABAergic drugs.

Honeybee colonies are exposed to numerous unfavourable threats from various diseases and environmental factors. Nosemosis type C is primarily a disease of the digestive tract in adult honey bees caused by the microsporidian Nosema ceranae. Since there is no authorized veterinary medicinal product for the treatment of the same and antibiotics are currently forbidden throughout the European Union due to possible determination residue levels in honey, it is important to find alternative treatments to control Nosemosis type C. The food supplements are fed to honey bees to supply the nutritive requirements of colonies in areas and during periods when natural food sources (pollen, nectar or honey) are inadequate or not available and they can improve the body functions, digestion, and help better utilization of food and development of their immune system.The aim of this study is to examine the effect of repeated applications of various food supplements (including herbs, minerals and protein ingredients) on the biochemical and histochemical indicators, including concentrations of total proteins and glucose. Mentioned parameters were determinated in five day old larvae samples originated from colonies repeatedly fed with different food additives (Nozevit, NozevitPlus, Eko ZeoPet, BeeWell AminoPlus, BPC-157). Additional feeding was performed according to manufacturerʼs instructions for use, respectively, and for Eko ZeoPet and BPC-157 was recalculate on the basis of described use in human and veterinary medicine. Sampling were performed 10th, 20th and 30th day from initial feeding. Total protein concentrations were measured using Bradford protein assay spectroscopic analytical procedure in suspension of larvae tissue. Glucose was measured using commercial Glucose (GO) Assay Kit. For the purpose of describing glycogen and/or oxidable dioles content we used the Periodic Acid-Schiff Reaction (PAS). Control group of honeybee colonies were fed with sugar syrup without any food supplement.Results for total proteins mean values concentrations ranges as follows: Nozevit 0.087-0.120 ; NozevitPlus 0.094-0.137 ; Eko ZeoPet 0.088-0.120 ; BeeWell Aminoplus 0.087-0.114 ; and BPC-157 0.091-0.114 (mg/mg larvae tissue), respectively. Among these results and also glucose concentrations isn’t found statistically significant difference, as well as between experimental and control group of honeybee colonies.

Copper, a transition metal with essential biological functions, exerts neurotoxic effects when present in excess. The aim of the present study was to explore the effects of quercetin, a plant-derived flavonoid and one of the most potent scavengers of reactive oxygen species (ROS), on the survival of differentiated P19 neurons exposed to high concentrations of copper ions. The obtained results indicate that effects of quercetin were determined by the severity of toxic insult. In moderately injured neurons exposed to 0.5 mM CuSO4 for 24 hours, 150 μM quercetin increased viability of P19 neurons by preventing ROS production, caspase-3/7 activity and chromatin condensation. Neuroprotective effect of quercetin on the survival of P19 neurons was prevented in the presence of wortmannin, an inhibitor of the PI3K/Akt signalling pathway. Treatment with 1 mM CuSO4 induced severe decrease in neuronal survival, due to very pronounced ROS accumulation, caspase-3/7 activation, and changed expression of genes involved in intracellular signalling and induction of apoptosis (p53, c-fos, Bcl-2 and Bax). In these conditions presence of 150 μM quercetin failed to affect neuronal survival, while 30 μM quercetin demonstrated strong pro-oxidative action and further exacerbated cytotoxic effects of copper, as evidenced by additional decrease in neuronal viability and very pronounced increase in ROS formation. The obtained results indicate the dual nature of quercetin action in copper-driven neurodegeneration. Both findings should be considered in the future development of novel antioxidative therapeutic strategies based on polyphenolic structures.