No / Mono- and disaccharide-functionalised conjugates of the fluoroquinolone antibiotic ciprofloxacin have been synthesised and used as chemical probes of the bacterial uptake of glycosylated ciprofloxacin. Their antimicrobial activities against a panel of clinically relevant bacteria were determined: the ability of these conjugates to inhibit their target DNA gyrase and to be transported into the bacteria was assessed by using in vivo and in vitro assays. The data suggest a lack of active uptake through sugar transporters and that although the addition of monosaccharides is compatible with the inhibition of DNA gyrase, the addition of a disaccharide results in a significant decrease in antimicrobial activity.

Indiana University-Purdue University Indianapolis (IUPUI) / Introduction: Regenerative endodontic therapy in immature teeth with necrotic pulps triggers continued root development, thereby improving the prognosis of these teeth. Disinfection of the canal is accomplished with an intracanal medicament, such as triple antibiotic paste (TAP) composed of metronidazole, ciprofloxacin, and minocycline. A modified triple antibiotic paste (MTAP) that replaces minocycline with clindamycin has recently been suggested to avoid the tooth discoloration and potential demineralization from minocycline. The effect these pastes have on radicular dentin is unknown. Objectives: The aim of this study was to investigate the effects of two intracanal medicaments used during endodontic regeneration, TAP and MTAP, at concentrations of 1 g/mL and 1 mg/mL, on the microhardness and chemical structure of radicular dentin. Materials and Methods: Roots from extracted, unrestored, non-carious human premolar teeth were sectioned. An antibiotic paste (MTAP or TAP) or sterile water (control) was applied to treatment groups and stored for four weeks in 80-percent humidity at 37 °C. The effect of each paste on the microhardness of radicular dentin was measured using a Vickers Microhardness Tester (n = 17) to take three pretreatment and post-treatment measurements at both 500 µm and 1000 µm from the pulp-dentin interface. The chemical structure was assessed from dentin specimens treated with the same medicaments or sterile water for four weeks. After treatment, three measurements were taken on each specimen using Attenuated Total Reflection Fourier Transform Infrared Spectroscopy to measure the phosphate/amide I ratios of dentin (n = 7). Results: The 1 g/mL of TAP or MTAP and the 1 mg/mL methylcellulose-based TAP caused significant reduction in microhardness of roots compared with untreated control roots at 500 µm and 1000 µm from the pulp-dentin interface. Furthermore, the methylcellulose-based 1 mg/mL TAP and MTAP caused significantly less reduction in microhardness compared with 1 g/mL TAP and MTAP. The 1 g/mL of TAP and DAP caused significantly lower phosphate/amide I ratios compared with other groups. Conclusion: The use of methylcellulose based 1 mg/mL of TAP and MTAP may minimize the reduction in microhardness of roots compared with the currently used 1 g/mL concentration of these antibiotics.

<p>Uvod: U pro&scaron;losti žučne kiseline su uglavnom razmatrane sa stanovi&scaron;ta njihove funkcije koju obavljaju u crevima jer posreduju u varenju masti i apsorpciji liposolubilnih vitamina. Nedavne studije potvrđuju da žučne kiseline ne igraju samo ulogu u varenju masti, nego se pona&scaron;aju i kao signalni molekuli koji stupaju u interakciju sa raznim receptorima uključujući nuklearne receptore i receptore vezane za G-proteine. Kao amfipatični molekuli one su sposobne da reaguju sa fosfolipidima ćelijskih membrana i da pobolj&scaron;avaju prolazak lekova kroz njih. Stoga se žučne kiseline razmatraju kao promoteri u bukalnim, okularnim i nazalnim farmaceutskim formulacijama. Cilj: Svrha ovog istraživanja je bila da se ispitaju žučne kiseline i njihovi okso derivati kao jedinjenja koja utiču na propustljivost ćelijskih membrana i prolazak lekova do ciljnih tkiva. Materijal i metod: Interakcije makrolidnih antibiotika i žučnih kiselina su ispitivane uz pomoć NMR difuzionih merenja i relaksacije paramagnetičnim jonima. Retencioni parametri odabranih žučnih kiselina su dobijeni kori&scaron;ćenjem hromatografije na normalnim fazama i evaluisani su primenom pet različitih softvera. In vivo ekaperimenti su sprovedeni na 126 eksperimentalnih životinja koje su bile podeljene u 21 grupu. Rezultati: Vezivanje žučnih kiselina za micele je indikovano razlikama u hemijskom pomeranju makrolida i pro&scaron;irenju signala kao posledica redukovane mobilnosti unutar micela. Dodatak micela žučnih kiselina povećava solubilizaciju makrolida za faktor približno 2-3. Sprovedena korelaciona analiza pokazala je značajnu zavisnost između faktora retencije i intestinalne apsorpcije, prodora u MDCK epitelne ćelije, permeabilnost kroz kožu, logBB i PPB%. Putem implementacije in vivo eksperimentalnog dela pokazano je da žučne kiseline utiču na prolazak makrolida u tkivo mozga, bubrega i jetre. Zaključak: Ispitivane žučne kiseline pokazuju dobre farmakokinetske karakteristike i olak&scaron;avaju prolazak makrolida kroz različite ćelijske membrane.</p> / <p>Introduction: In the past, bile acids were mostly considered to function in the intestine where they play a role in digestion of fats and mediate absorption of fat-soluble vitamins. Recent studies confirm that bile acids not only facilitate solubilization of fats but behave as signal molecules that interact with various receptors including nuclear receptors and G protein-coupled receptors. As amphipathic molecules they are able to interact with phospholipids of cells membranes and enhance drugs permeation. Thus, bile acids are considered as drug promoters in buccal, ocular, nasal, and transdermal dosage forms. Purpose: The purpose of this research was to investigate bile acids and its oxo derivatives as enhancers in drug permeability. Three research methods to evaluate the characteristics of bile acids and its properties were used. Material and method: The interaction between macrolide antibiotics and bile acids was investigated by NMR chemical-shift titration, self-diffusion measurements and paramagnetic relaxation enhancements. Retention parameters of selected bile acids are acquired by normal-phase thin layer chromatography and evaluated using five different softwares. In vivo experiments were conducted on 126 animals which were divided in 21 groups. Results: Binding bile acids to the micelles is indicated by differences in the chemical shift of the macrolides and line broadening as a consequence of reduced mobility in the micelle. Addition of bile micelles increases the solubility of macrolide antibiotics by a factor of approximately 2&ndash;3. Examined correlation analysis confirmed significant dependence between retention factor and intestinal absorption, MDCK epithelial cells, skin permeability, logBB and PPB%. Through the implementation of in vivo experiments it is shown that bile acids promote penetration of macrolides in brain tissue, kidney and liver. Conclusion: Investigated bile acids showed good pharmacokinetic properties and facilitate in macrolides permeation through various membranes.</p>

<p>Uvod: Antimikrobna rezistencija bakterija predstavlja globalni problem. Najvažniji faktor za njen nastanak je neadekvatna primena antibiotika, koja podrazumeva: Upotrebu antibiotika bez odgovarajuće dijagnoze, neadekvatan izbor leka, dužinu<br />primene i doziranje. Zbog specifičnosti populacije vitalno ugroženih bolesnika u jedinicama intenzivne terapije (JIT) i bolničkih infekcija uzrokovanih multirezistentnim bakterijama, primena antibiotika je na ovim odeljenjima učestala. Pokazana je povezanost između razvoja antimikrobne rezistencije i veličine potro&scaron;nje antibiotika u JIT. Cilj: Analiza primene antibiotika prema indikacijama na Klinici za anesteziju i intenzivnu terapiju, KC Vojvodine, zatim analiza stanja antimikrobne rezistencije<br />najče&scaron;ćih uzročnika bolničkih infekcija i analiza korelacije između navedenih uzročnika bolničkih infekcija i empirijski primenjivane antibiotske terapije na Klinici za anesteziju i intenzivnu terapiju. Materijal i metode: Prospektivna, opservaciona studija, sprovedena u jednogodi&scaron;njem period, u JIT, Klinike za anesteziju i intenzivnu terapiju, uključila je 856 ispitanika, oba pola, starijih od 18 godina kod kojih je tokom hospitalizacije u JIT bio primenjen antibiotik. Ispitanici su, radi prikupljanja podataka, bili podeljeni u dve grupe u zavisnosti od toga da li su imali bolničku infekciju ili ne. Adekvatnost primene antibiotika je analizirana prema indikacijama (hirur&scaron;ka profilaksa, bolničke infekcije, vanbolničke infekcije i drugo), a u odnosu na izbor antibiotika, dužinu primene, režim doziranja, veličinu pojedinačne doze i način promene terapije (prema preporukama farmakoterapijskog vodiča The Sanford guide to antimicrobial therapy i antimikrobnoj osetljivosti bakterijskih uzročnika bolničkih infekcija u JIT. Za izračunavanje potro&scaron;nje antibiotika u JIT kori&scaron;ćena je ATC/DDD metodologija. Podaci o antimikrobnoj osetljivosti dobijeni su iz rezultata mikrobiolo&scaron;ke obrade uzorkovanog materijala. Statistička analiza je izvr&scaron;ena pomoću statističkog paketa IBM SPSS 21 Statistics. Podaci su predstavljeni tabelarno i grafički, obrađeni su standardnim statističkim testovima, a statistička značajnost određivanja je bila na nivou p&lt; 0,05. Ispitivanje povezanosti između potro&scaron;nje anibiotika i antimikrobne rezistencije urađeno je primenom Pirsonovog koeficijenta korelacije. Rezultati: Izbor antibiotika kod bolesnika u JIT nije bio adekvatan u 52,19% preskripcija. Izbor empirijski indikovanih antibiotika za lečenje bolničkih infekcija nije bio u skladu antimikrobnom osetljivo&scaron;ću izolovanog uzročnika u 78,44% preskripcija. Izbor antibiotika za hirur&scaron;ku profilaksu nije bio adekvatan u 55,6% preskripcija. Antimikrobna rezistencija Acinetobacter spp.na karbapeneme, fluorohinolone i cefalosporine bila je preko 90%, na aminoglikozide preko 70%. Klebsiella pneumoniae bila je rezistentna na fluorohinolone i cefalosporine 80%, dok je na grupu karbapenema bila 18%. Pseudomonas aeruginosa je bio rezistentan na karbapeneme i aminoglikozide preko 50%, na antipseudomonasne cefalosporine preko 40%. Na kolistin nije zabeležena rezistencija ni jedne izolovane bakterijske vrste. Značajna pozitivna korelacija zabeležena je između potro&scaron;nje empirijski indikovanog meropenema i rezistencije Acinetobacter spp. Zaključak: U vise od 50% slučajeva primena antibiotika u JIT nije bila u skladu sa stanjem antimikrobne rezistencije bakterijskih uzročnika bolničkih infekcija i savremenim farmakoterapijskim protokolima. Antimikrobna rezistencija Acinetobacter spp, Klebsiellae pneumoniae и Pseudomonas aeruginosae je iznosila preko 20% na antibiotike preporučene savremenim farmakoterapijskim smernicama, osim u slučaju rezistencije Klebsiellaе pneumoniae na grupu karbapenema. Između pojave rezistencije Acinetobacter spp. i potro&scaron;nje empirijski indikovanog meropenema utvrđena je statistički značajna pozitivna povezanost, dok za druge dve navedene bakterijske vrste ova povezanost nije bila statistički značajna. Na osnovu podataka o najče&scaron;ćim bakterijskim uzročnicima i njihovoj antimikrobnoj osetljivosti za empirijsku<br />terapiju pneumonija mogao bi biti preporučen jedino kolistin, dok bi za lečenje urinarnih infekcija mogao biti preporučen imipenem ili meropenem. Potrebno je promeniti farmakoterapijski pristup u primeni antibiotika u JIT.</p> / <p>Uvod: Antimikrobna rezistencija bakterija predstavlja globalni problem. Najvažniji faktor za njen nastanak je neadekvatna primena antibiotika, koja podrazumeva: Upotrebu antibiotika bez odgovarajuće dijagnoze, neadekvatan izbor leka, dužinu<br />primene i doziranje. Zbog specifičnosti populacije vitalno ugroženih bolesnika u jedinicama intenzivne terapije (JIT) i bolničkih infekcija uzrokovanih multirezistentnim bakterijama, primena antibiotika je na ovim odeljenjima učestala. Pokazana je povezanost između razvoja antimikrobne rezistencije i veličine potro&scaron;nje antibiotika u JIT. Cilj: Analiza primene antibiotika prema indikacijama na Klinici za anesteziju i intenzivnu terapiju, KC Vojvodine, zatim analiza stanja antimikrobne rezistencije<br />najče&scaron;ćih uzročnika bolničkih infekcija i analiza korelacije između navedenih uzročnika bolničkih infekcija i empirijski primenjivane antibiotske terapije na Klinici za anesteziju i intenzivnu terapiju. Materijal i metode: Prospektivna, opservaciona studija, sprovedena u jednogodi&scaron;njem period, u JIT, Klinike za anesteziju i intenzivnu terapiju, uključila je 856 ispitanika, oba pola, starijih od 18 godina kod kojih je tokom hospitalizacije u JIT bio primenjen antibiotik. Ispitanici su, radi prikupljanja podataka, bili podeljeni u dve grupe u zavisnosti od toga da li su imali bolničku infekciju ili ne. Adekvatnost primene antibiotika je analizirana prema indikacijama (hirur&scaron;ka profilaksa, bolničke infekcije, vanbolničke infekcije i drugo), a u odnosu na izbor antibiotika, dužinu primene, režim doziranja, veličinu pojedinačne doze i način promene terapije (prema preporukama farmakoterapijskog vodiča The Sanford guide to antimicrobial therapy i antimikrobnoj osetljivosti bakterijskih uzročnika bolničkih infekcija u JIT. Za izračunavanje potro&scaron;nje antibiotika u JIT kori&scaron;ćena je ATC/DDD metodologija. Podaci o antimikrobnoj osetljivosti dobijeni su iz rezultata mikrobiolo&scaron;ke obrade uzorkovanog materijala. Statistička analiza je izvr&scaron;ena pomoću statističkog paketa IBM SPSS 21 Statistics. Podaci su predstavljeni tabelarno i grafički, obrađeni su standardnim statističkim testovima, a statistička značajnost određivanja je bila na nivou p&lt; 0,05. Ispitivanje povezanosti između potro&scaron;nje anibiotika i antimikrobne rezistencije urađeno je primenom Pirsonovog koeficijenta korelacije. Rezultati: Izbor antibiotika kod bolesnika u JIT nije bio adekvatan u 52,19% preskripcija. Izbor empirijski indikovanih antibiotika za lečenje bolničkih infekcija nije bio u skladu antimikrobnom osetljivo&scaron;ću izolovanog uzročnika u 78,44% preskripcija. Izbor antibiotika za hirur&scaron;ku profilaksu nije bio adekvatan u 55,6% preskripcija. Antimikrobna rezistencija Acinetobacter spp.na karbapeneme, fluorohinolone i cefalosporine bila je preko 90%, na aminoglikozide preko 70%. Klebsiella pneumoniae bila je rezistentna na fluorohinolone i cefalosporine 80%, dok je na grupu karbapenema bila 18%. Pseudomonas aeruginosa je bio rezistentan na karbapeneme i aminoglikozide preko 50%, na antipseudomonasne cefalosporine preko 40%. Na kolistin nije zabeležena rezistencija ni jedne izolovane bakterijske vrste. Značajna pozitivna korelacija zabeležena je između potro&scaron;nje empirijski indikovanog meropenema i rezistencije Acinetobacter spp. Zaključak: U vise od 50% slučajeva primena antibiotika u JIT nije bila u skladu sa stanjem antimikrobne rezistencije bakterijskih uzročnika bolničkih infekcija i savremenim farmakoterapijskim protokolima. Antimikrobna rezistencija Acinetobacter spp, Klebsiellae pneumoniae i Pseudomonas aeruginosae je iznosila preko 20% na antibiotike preporučene savremenim farmakoterapijskim smernicama, osim u slučaju rezistencije Klebsiellae pneumoniae na grupu karbapenema. Između pojave rezistencije Acinetobacter spp. i potro&scaron;nje empirijski indikovanog meropenema utvrđena je statistički značajna pozitivna povezanost, dok za druge dve navedene bakterijske vrste ova povezanost nije bila statistički značajna. Na osnovu podataka o najče&scaron;ćim bakterijskim uzročnicima i njihovoj antimikrobnoj osetljivosti za empirijsku<br />terapiju pneumonija mogao bi biti preporučen jedino kolistin, dok bi za lečenje urinarnih infekcija mogao biti preporučen imipenem ili meropenem. Potrebno je promeniti farmakoterapijski pristup u primeni antibiotika u JIT.</p> / <p>Introduction: Antimicrobial resistance is a global health problem.The most important factor in the development of antimicrobial resistance is inadequate use of antibiotics, which means: inadequate diagnosis of bacterial infection, inadequate antibiotic choice, dosage and duration of therapy. Specificities of critically ill patients and nosocomial infections caused by multidrug-resistant pathogens are important reasons for large antibiotic consumption in ICU settings. Many studies have confirmed a positive correlation between antibiotic use and antimicrobial resistance. Aims: The aims of this study were: to analyze the use of antibiotics at the ICU of the Clinic for anesthesia and intensive care at the Clinical Centre of Vojvodina, according to indications for antibiotic treatment; to analyze the pattern of antimicrobial resistance ofthe most common bacteria causing hospital acquired infections in our participants and to analyze the correlation between the consumption of empirically indicated antibiotics and antimicrobial resistance pattern. Methodology: Prospective observational study was conducted during a one-year period at the Clinic for anesthesia and intensive care, Clinical Centre of Vojvodina. The study included 856 participatns, aged over 18 years and of both genders. The participants were divided into two cohorts, depending on whether they showed symptoms of hospital-acquired infection or not. Adequacy of antibiotic use was analyzed with regard to indication for antibiotic treatment (surgical prophylaxis, treatment of hospital acquired infection, outpatient infection or other) and with regard to antibiotic choice, dosage and duration of treatment. An adequate antibiotic choice was compared to the resistance pattern of positive bacterial isolates as outlined by The Sanford guide to antimicrobial therapy). To calculate the consumption of antibiotics in ICU we used ATC/DDD methodology. Data on antibacterial sensitivity was obtained from the results of microbiological analysis of sample materials. IBM SPSS version 21 was used for statistical analysis, standard statistical tests were applied. The results were presented in tables and graphs. Statistically significant correlation was set at the value of p˂0.05. Pearson correlation coefficient was used to measure the strength between variables. Results: Antibiotic choice was inadequate in 52,19% of all antibiotic prescriptions for all indications. Antibiotic choice in surgical prophylaxis was inadequate in 55,59% of prescriptions for this indication. Inadequate choice of empirically indicated antibiotics (for treatment of hospital-acquired infections) according to antimicrobial resistance pattern occurred in 78,44% of all prescription for this indication. The three the most important bacterial causative agents of hospital acquired infections in ICU were: Acinetobacter spp, Klebsiella pneumonia and Pseudomonas aeruginosa. The resistance of Acinetobacter spp. to antibiotic groups was as follows: to carbapenems, fluoroquinolones and cephalosporins over 90% and to aminoglycosides over 70%. The antimicrobial resistance of Klebsiella pneumoniae was: to fluoroquinolones and cephalosporins over 80% and to carbapenems up to 20%. The resistance pattern of Pseudomonas aeruginosa was as follows: to carbapenems and aminoglykozides over 50%, and to antipseudomonal cephalosporins over 40%. Statistically significant correlation was found between the consumption of empirically prescribed meropenem and antimicrobial resistance of Acinetobacter spp. Conclusion:In more than 50% of antibiotic prescriptions at ICU, regardless of indication, the choice of prescribed antibiotics was inadequate. Antimicrobial resistance pattern of Acinetobacter spp, Klebsiella pneumoniae and Pseudomonas aeruginosa to antibiotics recomennded by contemporary guidelines for antimicrobial therapy was over 20%, except in the case of the resistance of Klebsiellae peneumoniae to carbapenems. Statistically significant correlation was found between the consumption of empirically prescribed meropenem and antimicrobial resistance of Acinetobacter spp. No statistically significant correlation was observed in the other two bacterial strains. Initial, empiric therapy for nosocomial pneumonia in our ICU, should be colistin, and for urinary tract infection imipenem or meropenem. It is important to change antibiotic prescribing praxis in ICU.</p>

As international travel is rapidly increasing, more people are being exposed to potentially more antibiotic resistant bacteria, a changed infectious disease epidemiology, and an increased risk of accidents and crime. Research-based advice is needed to adequately inform travellers about these risks. We studied travellers who sought advice from the Travel Medicine Clinic at the Department of Infectious Diseases, Umeå University Hospital, as well as university students from Umeå, Stockholm, and Gothenburg travelling abroad for study, research, and clinical exchange programs. From retrospective data at the Travel Medicine Clinic, we found that pre-existing health problems were rare among travellers from Umeå seeking pre- travel health advice and vaccinations. In addition, we found that the travel destination and the sex of the traveller affected vaccination levels. Although hepatitis A is endemic to both Thailand and Turkey, compared to travellers to Thailand few travellers to Turkey visited the clinic for hepatitis A vaccination. The data also revealed that more women than men were vaccinated against Japanese encephalitis despite comparable trips. A prospective survey study showed that travellers felt that the pre-travel health advice they received was helpful. Two-thirds of the travellers followed the advice given although they still fell ill to the same extent as those who were not compliant with the advice. Factors outside the control of travellers likely affect the travel-related morbidity. Compared to older travellers, younger travellers were less compliant with advice, fell ill to a greater extent, and took greater risks during travel. In a prospective survey study, we found that healthcare students had higher illness rates and risk exposure when abroad compared to students from other disciplines. This difference was mainly due to the fact that healthcare students more often travelled to developing regions during their study period abroad. When abroad, half of all students increased their alcohol consumption and this was linked to an increased risk of theft and higher likelihood of meeting a new sex partner. The healthcare students participating in the survey study also submitted stool samples before and after travel. These samples were tested for the presence of antibiotic resistance, both by selective culturing for ESBL-PE (Extended-Spectrum Beta-Lactamase Producing Enterobacteriaceae) as well as by metagenomic sequencing. About one-third (35%) of the students became colonised by ESBL-PE following their study abroad. The strongest risk factor for colonisation was travel destination; for example, 70% of students who had travelled to India became colonised. Antibiotic treatment during travel was also a significant risk factor for colonisation. The stool samples from a subset of study subjects were analysed using metagenomic sequencing. From this we learned that although the majority of resistance genes in the gut microbiome remained unchanged following travel, several clinically important resistance genes increased, most prominently genes encoding resistance to sulphonamide, trimethoprim, and beta-lactams. Overall, taxonomic changes associated with travel were small but the proportion of Proteobacteria, which includes several clinically important bacteria (e.g., Enterobacteriaceae), increased in a majority of the study subjects. Clearly, there are risks associated with international travel and these risks include outside factors as well as the personal behaviour of travellers. We believe our results can be used to develop better pre-travel advice for tourists as well as university students studying abroad resulting in safer travel.

Diss. (sammanfattning) Linköping : Univ., 2004. / Härtill 5 uppsatser.

<p>Nesavesna upotreba antibiotika izazvala je razvoj antimikrobne rezistencije zabrinjavajućih razmera. Porast rezistencije prema konvencionalnim antimikrobicima nametnuo je potrebu pronalaska novih supstanci, koje će biti delotvorne protiv otpornih sojeva. U poslednje četiri decenije, dominira trend da se lekovi i lekovita sredstava prave na bazi prirodnih proizvoda, a naročito biljnog materijala. Hemijski sastav plodova porodice ruža (Rosaceae) upućuje na to da bi određene vrste ove porodice biljaka mogle ispoljavati antimikrobno dejstvo. Plodovi voća porodice Rosaceae istraživani u okviru ove disertacije su: malina (Rubus idaeus), kupina (Rubus fruticosus), tre&scaron;nja (Prunus avium), vi&scaron;nja (Prunus cerasus) i aronija (Aronia prunifolia). Predmet istraživanja ove doktorske disertacije je antimikrobno tj. antibakterijsko, antigljivično, antialgalno i antivirusno dejstvo sokova i ekstrakata plodova odabranog voća porodice Rosaceae gajenog i prikupljenog na teritoriji Srbije na &scaron;irok spektar humanih i animalnih patogenih mikroorganizama.Sokovi su dobijeni ceđenjem svežih plodova voća. Ekstrakti su dobijeni iz ostataka voća nakon ceđenja (tropa) metodom dvostruke etanolne ekstrakcije. Nakon ceđenja i ekstrakcije sprovođeno je uparavanje do suva sokova i ekstrakata. HPLC metodom je ispitano prisutstvo 23 hemijske komponente u svakom od sokova i ekstrakata. Antimikrobna analiza je sprovedena na 21 mikroorganizmu, od čega su 15 bile bakterije, 2 gljivice, 2 alge i 2 virusi. Od navedenih mikroorganizama 14 je bilo autohtonih izolata, a 7 referentnih sojeva. Ispitivanje antibakterijskog, antifungalnog i antialgalnog dejstva plodova odabranog voća je sprovedeno difuzionom i mikrodilucionom metodom. Analiza antivirusne aktivnosti plodova odabranog voća je sprovedena posmatranjem inhibicije citopatogenog efekta (CPE) virusnih čestica na ćelijsku kulturu. Sve studije su sprovedene u triplikatu. Rezultati hemijske analize su obrađeni statistikom metodom srednje vrednosti, uz računanje standardne devijacije. Eksperimentalno dobijeni podaci u okviru ispitivanja antibakterijskog, antigljivičnog i antialgalnog dejstva su uvr&scaron;teni u statističku analizu. Metodom aproksimacije je utvrđena tačna koncentracija soka ili ekstrakta koja daje željeni efekat na ispitivani mikroorganizam. Rezultati analize antivirusnog dejstva su statistički obrađeni metodom srednje vrednosti. Kako bi se utvrdio stepen povezanosti rezultata dobijenih u okviru antimikrobnih analiza sa hemijskim supstancama prisutnim u plodovima odabranog voća sprovedena je regresiona analiza za vaki pojedinačni slučaj. Antibakterisjko, antiungalno i antialgalno dejstvo sokova i ekstrakata je upoređeno sa istim dejstvima konvencionalnih antimikrobnih lekova. Najveću ukupnu količinu ispitivanih supstanci je sadržao ekstrakt kupine (3965,56 mg/ml), a najmanju ekstrakt tre&scaron;nje (161,44 mg/ml). Od svih ispitivanih hemijskih supstanci, samo su: antocijani, katehin, galna kiselina i vitamin C, prisutni u svim ispitivanim sokovima i ekstraktima. Sve ispitivane biljke sadrže veću količinu supstanci u ekstraktu, osim kod tre&scaron;nje, kod koje se veća količina supstanci nalazi u soku. U najvećoj meri su u sokovima i ekstraktima plodova biljaka prisutni antocijani i to najvi&scaron;e kod kupine od ekstrakata, a kod maline od sokova. Antimikrobno (antibakterijsko, antifungalno, antialgalno i antivirusno) dejstvo je dokazano za svaki od sokova i/ili ekstrakata plodova odabranog voća. Po prosečnim vrednostima rezultata dilucione analize antimikrobnog i dejstva na MDBK ćelije, protiv najvećeg broja mikroorganizama najdelotvorniji je bio ekstrakt kupine, a neaktivan ili najslabije aktivan (aktivan u najvećoj koncentraciji) sok tre&scaron;nje. Prosečne vrednosti antimikrobnog i dejstva na MDBK ćelije su bile u opsegu od 0,71 mg/ml do 100 mg/ml. Sve ispitivane supstance su pokazale antibakterijsku aktivnost u ispitivanim koncentracijama na sve ispitivane bakterije, osim soka maline na Escherichia-u coli i soka aronije na Klebsiella-u pneumoniae. Ekstrakti su bolje delovali u većini slučajeva, uz nekoliko izuzetaka. Sve ispitivane supstance su pokazale antfiungalnu aktivnost na Candida-u albicans ATCC 24433, osim soka aronije. Na autohtoni soj Candida-e albicans su delovali samo ekstrakti kupine i tre&scaron;nje. Ekstrakti su bolje delovali u većini slučajeva, osim kupine na Candida-u albicans ATCC 24433, u kojem je dejstvo soka bilo jednako sa dejstvom ekstrakta. Iako su skoro svi ispitivani sokvi i ekstrakti ispoljili antialgalno dejstvo, na Prototheca-u wickerhamii nisu delovali vi&scaron;nja i sok maline, dok sok aronije nije delovao antialgalno ni na jednu od ispitivanih Prototheca. Ekstrakti su bolje delovali u većini slučajeva, osim maline kod koje je, u oba slučaja, bolje delovao sok. Sve ispitivane supstance su pokazale antivirusnu aktivnost na Bovine herpesvirus i Bovine viral diarrhea virus, kao i toksičnost na MDBK ćelije, osim sokova maline i tre&scaron;nje, koji su bili neaktivni protiv Bovine herpesvirus-a. Ekstrakti su bolje delovali u većini slučajeva, osim tre&scaron;nje na MDBK ćelije i Bovine viral diarrhea virus, na koje je jače delovao sok. U potpunosti jednako delovanje soka i ekstrakta je uočeno kod aronije za sva tri dejstva i maline za toksičnost na MDBK ćelije. Pri ispitivanju difuzionom metodom antibiotik je ispoljio jače dejstvo u odnosu na sokove i ekstrakte, osim ekstrakata kupine, maline i vi&scaron;nje na Trueperella-u pyogenes. Pri ispitivanju dilucionom metodom, dejstvo ekstrakata i sokova na Gram pozitivne bakterije je bilo uporedivo sa dejstvom Streptomicina, dok je dejstvo antibiotika na Gram negativne bakterije bilo jače u odnosu na sokove i ekstrakte, izuzetev jačeg dejstva ekstrakta maline protiv Escherichia-e coli. Nistatin je sve antifungalne i antialgalne efekte na gljivice i alge obuhvaćene istraživanjem ispoljio u manjim koncentracijama u odnosu na ispitivane sokove i ekstrakte.Najpovezanije sa antibakterijskim dejstvom sokova i ekstrakata na odgovarajuće mikroorganizme su bile: kumarinska, ferulna i galna kiselina, katehin. Najveći procenat povezanosti sa antimikrobnom aktivnosti ploda imali su antocijani na Enterococcus faecalis (71,94%). Najmanje povezani sa antimikrobnom aktivnosti na odgovarajuće mikroorganizme su bili: hlorogenska kiselina, kempferol, kumarinska i siringinska kiselina, vitamin C, vanilinska kiselina, epikatehin, katehin, rutin, krisin, elaginska i p-hidroksibenzoeva kiselina. Saznanja dobijena u okviru ove disertacije pro&scaron;iruju obim znanja o antimikrobnom dejtvu voća i predstavljaju osnovicu za svrsishodniju primenu voća kako u ishrani tako i u terapiji. Međutim, dalja istraživanja u smislu pro&scaron;irenja spektra ispitivanih mikroorganizama, antimikrobnih studija pojedinačnih komponenti iz plodova i mehanizama dejstva su potrebna.</p> / <p>Nonconscientious use of antibiotics has caused the development of antimicrobial resistance of worrying proportions. The increase in resistance to conventional antimicrobials has imposed a need to find new substances that will be effective against resistant strains. Over the last four decades, the trend is to medicines and medicinal products be made on the basis of natural products, and especially plant material. The chemical composition of the Rose family (Rosaceae) fruits suggests that certain species of this family of plants may exhibit an antimicrobial effect. The fruits of the Rosaceae family studied in the framework of this dissertation are: Raspberry (Rubus idaeus), Blackberry (Rubus fruticosus), Cherry (Prunus avium), Cherry (Prunus cerasus) and Aronia (Aronia prunifolia). The subject of the research of this doctoral dissertation is antimicrobial ie. antibacterial, antifungal, antialgal and antiviral effects of juices and fruit extracts, of the selected fruit of the Rosaceae family collected on the territory of Serbia, on a wide range of human and animal pathogenic microorganisms. Juices were obtained by the process of squeezing fresh fruits. The extracts were obtained from residues of fruits after extraction (pomace) by the double ethanol extraction method. After squeezing and extraction, evaporation to dryness of juices and extracts was carried out. The presence of 23 chemical components in each of the juices and extracts was examined by the HPLC method. Antimicrobial analysis was carried out on 21 microorganisms, of which 15 were bacteria, 2 fungi, 2 algae and 2 viruses. 14 of these microorganisms were autochthonous isolates and 7 reference strains. The antibacterial, antifungal and antialgal effect of the selected fruit was tested by the diffusion and microdilution method. The analysis of the fruits antiviral activity was carried out by observing the inhibition of cytopathogenic effect (CPE) of viral particles per cell culture. All studies were conducted in triplicate. The results of the chemical analysis were processed by means of a mean value method, with calculation of the standard deviation. The experimentally obtained data within the antibacterial, antifungal and antialgal examination were included in the statistical analysis. The method of approximation was used in order to determine the exact concentration of the juice or extract, which gives the desired effect on the examined microorganisms. The results of the antiviral analysis were statistically processed using the mean value method. In order to determine the degree of correlation of the results obtained in the framework of antimicrobial analysis with the chemical substances present in the fruits of the selected fruit, regression analysis was carried out for each individual case. Antibacterial, antifungal and antialgic effects of juices and extracts are compared with he same effects of conventional antimicrobial drugs, Streptomycin and Nystatin. The largest total amount of test substances was contained by blackberry extract (3965.56 mg/ ml), and the smallest by extract of sweet cherry (161.44 mg/ ml). Of all the investigated chemicals, only: anthocyanins, catechins, gallic acids and vitamin C were present in all examined juices and extracts. All investigated plants contain a higher amount of substances in the extract, except for sweet cherries, in which a greater amount of substances is present in the juice. In the juices and extracts of fruits anthocyanins are present to the greatest extent, mostly in the blackberry extract, and in raspberry juices. According to the average values of the results of the dilution analysis of the antimicrobial and the effect on the MDBK cell, the most effective was the blackberry extract and the most active inactive (active in the highest concentration) cherry juice against the most numerous microorganisms. The average antimicrobial values and effects on the MDBK cells were in the range of 0.71 mg/ ml to 100 mg/ ml. All investigated substances showed antibacterial activity in the tested concentrations on all examined bacteria, except raspberry juice on Escherichia coli and aronia juice on Klebsiella pneumoniae. Extracts acted better in most cases, with few exceptions. All investigated substances showed antifungal activity on Candida albicans ATCC 24433, except aronia juice. On the autochthonous Candida albicans, only blackberry and sweet cherry extracts were active. Extracts worked better in most cases, except for blackberry on Candida albicans ATCC 24433, in which the effect of the juice was equally efficient as the extract. Although almost all of the examined juices and extracts exhibited an antialgal effect, the sour cherry and raspberry juice did not work on the Prototheca wickerhamii, while the aronia juice did not express antialgal activity to any of tested Prototheca isolates. Extracts worked better in most cases, apart from raspberries, wich juice was stronger in both cases. All investigated substances showed antiviral activity on Bovine herpesvirus and Bovine viral diarrhea virus, as well as the toxicity to MDBK cells, except for raspberry and cherry juices, that were inactive against Bovine herpesvirus. The extracts worked better in most cases, except sweet cherries on MDBK cells and Bovine viral diarrhea virus, whose juice had stronger effect. The equally effective action of juice and extract was observed in aronia for all three effects and raspberries for toxicity to MDBK cells. In the diffusion test, antibiotic showed a stronger effect than juices and extracts, except for extracts of blackberry, raspberry and sour cherries on Trueperella pyogenes. In a dilution study, the effect of extracts and juices on Gram-positive bacteria was comparable to that of Streptomycin, while the effect of the antibiotic on Gram negative bacteria was stronger than juices and extracts, with exception of the stronger effect of raspberry extract against Escherichia coli. Nystatin has expressed its all antifungal and antialgal effects on fungi and algae included in the study in smaller concentrations compared to the examined juices and extracts. The most consistent with the antibacterial effect of juices and extracts on the appropriate microorganisms were: coumarin, ferulan and gallic acid, catechin. The highest percentage of association with antimicrobial activity of the fruits was given by anthocyanins to Enterococcus faecalis (71.94%). The least related to the antimicrobial activity on the appropriate microorganisms were: chlorogenic acid, champferol, coumarin and saringic acid, vitamin C, vanillic acid, epicatechin, catechin, rutin, chrysin, elaginic and p-hydroxybenzoic acid. The knowledge gained through this dissertation expands the scope of knowledge on antimicrobial activity of fruits and forms the basis for more effective use of fruits in both therapy and nutrition. However, further research in terms of extending the range of examined microorganisms, antimicrobial studies of individual fruits components and mechanisms of action are required.</p>

Indiana University-Purdue University Indianapolis (IUPUI) / Endodontic regeneration treatment of necrotic immature teeth has gained popularity in recent years. The approach suggests a biological alternative to induce a continuous root development. In this project, three in vitro experiments were conducted to investigate the effect of three medicaments used in endodontic regeneration on mechanical properties and chemical structure of radicular dentin. In the first experiment, we investigated longitudinally the effect of medicaments on the indentation properties of the root canal surface of immature teeth using a novel BioDent reference point indenter. A significant difference in the majority of indentation parameters between all groups was found after one-week and one-month application of medicaments (p<0.0001): triple antibiotic paste (TAP) > double antibiotic paste (DAP) > control > calcium hydroxide [Ca(OH)2]. The four-week exposure of dentin to TAP and DAP caused 43% and 31% increase in total indentation distance outcome, respectively. In the second experiment, we investigated longitudinally the effect of medicaments on the chemical structure of immature radicular dentin by measuring the phosphate/amide I ratios of dentin using Attenuated Total Reflection Fourier Transform Infrared Spectroscopy. Phosphate/amide I ratios were significantly different between the four groups after one week, two weeks and four week application of medicaments (p<0.0001): Ca(OH)2-treated dentin > untreated dentin > DAP-treated dentin > TAP-treated dentin. In the third experiment, we investigated longitudinally the effect of medicaments on root fracture resistance and microhardness of radicular dentin. For the microhardness, the two-way interaction between group and time was significant (p<0.001). TAP and DAP caused a significant and continuous decrease in dentin microhardness after one and three month application, respectively. The three-month intracanal application of Ca(OH)2 significantly increased the microhardness of root dentin. The time factor had a significant effect on fracture resistance (p<0.001). All medicaments caused significant decrease in fracture resistance ranging between 19%-30% after three month application compared to one week application. The three medicaments used in endodontic regeneration caused significant change in the chemical integrity of the superficial radicular dentin and significantly affected the indentation properties of the root canal surface. Furthermore, the three month intracanal application of medicaments significantly reduced the fracture resistance of roots.

Indiana University-Purdue University Indianapolis (IUPUI) / Purpose: Dental sealant forms a physical barrier to prevent pit and fissure caries; therefore, the retention rate becomes a main factor of the sealant’s effectiveness. Electrospun nylon-6/N6 nanofibers have shown good mechanical properties, such as high tensile strength and fracture toughness. Chitosan/CH has received significant attention due to properties such as antibacterial activity. The purpose of this study was to synthesize and evaluate the effect of incorporating N6 and CH electrospun nanofibers on the physical-mechanical and antibacterial properties of an experimental resin-based sealant. Methods and Materials: Nanofiber synthesis: N6 pellets were dissolved in 1,1,1,3,3,3-hexafluoro-2-propanol at a concentration of 10wt%. Practical-grade chitosan was dissolved in trifluoroacetic acid and dichloromethane (60:40 TFA/DCM) at 7 wt%. Electrospinning parameters were optimized in order to fabricate defect-free N6 and chitosan nanofiber mats. Morphological and chemical characterizations were performed by scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy, respectively after vacuum drying the mats for 48 h. The average fiber diameter was determined from SEM images by measuring the diameter of 120 fibers using ImageJ software. Experimental Sealant: N6 and CH electrospun mats (3×3cm2) were immersed into a resin mixture of BIS-GMA/TEGDMA. Once no bubbles were seen, the resin-modified N6 and CH mats were put on a glass plate, light-cured (“TRIAD 2000”) for 2 min and then submitted to a cryomilling process to obtain a fine micron-sized powder. Three different filler levels (1 wt%, 2.5 wt%, 5 wt%) were used to prepare the N6 and CH incorporated resin-based sealants. Additionally, a commercially available resin-based sealant and the experimental resin mixture (unfilled) were used as controls. Three-point flexural testing, Vickers microhardness testing, and agar diffusion testing were performed on the experimental sealants and the commercial sealant. Data were analyzed by one-way ANOVA and Fisher's Protected Least Significant Differences Pair-wise comparisons between groups (5%). Results: The average fiber diameter for N6 was found to be 503±304 nm and 595±411 nm for CH. No significant difference was found between fiber diameter (p = 0.0601). FTIR confirmed the characteristic peaks for N6 ((CO-NH and [-(CH2)5-].) and CH (N-H and C2F3O2-). CH-5% group had significantly higher (p = 0.0000) FS (115.3±4.5 MPa) than all other groups. CH-1% and CH-2.5% groups had significantly higher FS than the control (unfilled) (p = 0.0016 and p = 0.0033 respectively); Helioseal Clear (p = 0.0000), and nylon groups. N6-5% had significantly higher flexural strength than Helioseal Clear (p = 0.0013) and N6-2.5% (p = 0.0250). CH-1% had significantly higher hardness values than all other groups, and CH-5% (p = 0.0414) had significantly higher values than N6-2.5%. No antibacterial inhibition was seen in any of the tested groups. Conclusions: CH and N6 nanofibers were successfully prepared via electrospinning and used to modify the experimental resin-based dental sealants. The overall results indicated that CH-containing sealants presented the highest flexural strength and hardness; however, none of the CH groups displayed antimicrobial properties. Further investigation is needed to enhance the physico-mechanical properties of the experimental resin-based sealants using nylon-6 and CH.

Indiana University-Purdue University Indianapolis (IUPUI) / Introduction: Regenerative endodontic therapy in immature teeth promotes continuation of root development and likely increases the prognosis of these teeth. The use of double antibiotic paste (DAP), equal parts of ciprofloxacin and metronidazole, followed by the dentin conditioner, ethylenediaminetetraacetic acid (EDTA), has been suggested for canal disinfection and facilitation of stem cell attachment/proliferation, respectively. However, the effect is unknown when all these agents are used on on radicular dentin surfaces to facilitate the level of stem cell proliferation. Objectives: The aim of this in-vitro study is to compare the proliferation of human dental pulp stem cells (hDPSCs) on human radicular dentin treated with two different concentrations of DAP followed by EDTA. Materials and Methods: Human premolars and incisors were prepared into standardized polished 4 mm x4 mm radicular dentin specimens. Groups of specimens were treated with DAP 500 mg/mL, DAP 1 mg/mL, DAP 500 mg/mL followed by 17-percent EDTA, DAP 1 mg/mL followed by 17-percent EDTA; 17% EDTA, or no treatment. All groups treated with antibiotics were incubated with DAP at 37°C for one week. All specimens were washed with distilled water. The hDPSCs were seeded across all specimens and unattached cells were collected after 24 hours. LDH assay was completed on unattached cells for quantification. Three days after attachment, WST viability and LDH cytotoxicity assays were performed. Hypothesis: There is no significant difference in hDPSC viability, unattachment, and cytotoxicity on dentin specimens treated with DAP and 17-percent EDTA. Clinical Significance: These results can be used to help identify the best treatment concentrations when using DAP and/or EDTA to promote endodontic regeneration. Results: The results demonstrated significantly less viability of hDPSCs on specimens treated with 500 mg/mL DAP with and without 17-percent EDTA. Groups treated with 1 mg/mL DAP, 1 mg/mL DAP and 17-percent EDTA, and 17-percent EDTA alone had no statistically significant difference in viability compared with control untreated dentin. The results of the unattached cells from the LDH demonstrated that cells from the specimens treated with solely 500 mg/mL and 1 mg/mL DAP had significantly higher levels of unattached cells when compared with all other groups. The LDH assays in summation with the WST assays showed a trend of a lack of proliferation on groups treated with 500 mg/mL DAP with and without 17-percent EDTA. Conclusions: Paste-like concentrations (500 mg/mL) of DAP are detrimental to hDPSC viability, whereas the present study supports the use of low-concentration antibiotics consistent with current recommendations for intracanal medicaments used during endodontic regenerative procedures.