Radiossensibilizadores são definidos como agentes químicos que aumentam a sensibilidade das células hipóxicas à radiação, visando o aumento da eficácia da radioterapia no tratamento do câncer. Alguns Carboxilatos de Rh (II) e compostos nitroimidazólicos têm sido testados como radiossensibilizadores em doses elevadas de radiação, obtendo-se resultados significativos. Neste trabalho, foram sintetizados vários carboxilatos e um amidato de Rh (II): propionato, butirato, trifluoroacetato, citrato e trifluoroacetamidato, assim como os seus respectivos adutos com metronidazol, de fórmula geral: [Rh2(RCOO)4metro2] (R = CH3, C2H5, C3H7, C5 H7O5, e CF3) para o caso dos carboxilatos e [Rh2(CF3CONH) 4 metro2] para o aduto de trifluoroacetamidato. Os compostos foram caracterizados por análise elementar, espectroscopia eletrônica, infravermelho e de ressonância magnética nuclear de próton. O resultado desta caracterização permitiu estabelecer as rotas de síntese confirmando a formação dos carboxilatos tipo ponte e a presença do metronidazol nas posições axiais, numa relação 1:2. O efeito radiossensibilizador desses complexos de Rh (II) foi testado in vitro, irradiando-se, em atmosfera hipóxica, células de ovário de hamster chinês (CHO k1), na presença dos complexos, utilizando-se raios gama provenientes de uma fonte de 60Co, com doses de 2,7 e 4,3 Gy. Foi realizado teste de citotoxicidade para determinar as concentrações atóxicas de cada composto, eliminando a possibilidade de morte celular devido ao efeito tóxico dos mesmos. Na dose 2,7 Gy não houve nenhum efeito interessante; já com a dose de 4,3 Gy o [Rh2(CH3 COO)4] mostrou uma atividade radiossensibilizadora maior do que nos demais complexos. Os resultados foram semelhantes aos obtidos na literatura com doses de radiação até 10 vezes maiores. Devido à ausência de mudanças significativas no efeito radiossensibilizador entre os carboxilatos e amidato e seus respectivos adutos com metronidazol, foi determinada a constante de formação destes últimos, demonstrando que os mesmos sofrem decomposição quando em solução aquosa diluída. / Radiosensitizers are chemical agents that enhance the radiation sensitivity of hipoxic tumor cells aiming to better radiotherapy efficacy in the treatment of cancer. Some Rhodium (II) carboxylates and its adducts with nitroimidazole derivatives, have been tested as radiosensitizers in high doses of radiation, being obtained significant results. In this work, several Rhodium carboxylates and one Rhodium amidate previously described were synthesized: propionate, trifluoroacetate, citrate and , trifluoroacetamidate, as well as their respective adducts with nitroimidazole of general formula [Rh2(RCOO)4metro2] for the carboxylates and [Rh2(CF3CONH)4metro2] for the trifluoroacetamidate adduct. The compositions where characterized by elementary analysis, electronic and infrared spectroscopy and proton nuclear magnetic resonance. The results of that characterization allowed us to establish the synthesis routes and confirm the bridge type structure of the Rodhium compounds, beyond the presence of the metronidazole at the axial positions in the proportions of 1:2. The radiosensitizing effects of these Rh (II) complexes were tested in vitro by irradiation of Chinese hamster (CHO k1) cells under hipoxic atmosphere in the presence of the complexes, using gamma rays from a 60Co source and doses of 2,7 and 4,3 Gy. A cytotoxicity test has been performed to determinate the non-toxic concentrations of these compounds, in order to rule out the possibility of cellular death induced by the complexe´s cytotoxicity. A 2,7 Gy dose showed no interesting effects but under a 4,3 Gy dose, the complex Rh2(CH3 COO)4 showed a higher radiosensitizing effect than the order compounds and close to previously reported effects which required high radiation doses. As there was not a significant change in the radiosensitizing effect between the carboxylate and the amidate and their respective metronidazole adducts it was performed the measurement of the formation constant of that adducts. The results of that measurements gave evidence of adduct decomposition when in dilute aqueous solution.

A Diabetes mellitus do tipo I (IDDM), doença metabólica caracterizada pela deficiência na produção de insulina, causa profundas alterações sistêmicas, incluindo a cavidade bucal. A doença periodontal, que se apresenta mais agressiva em pacientes diabéticos, até mesmo na infância, tem como agentes etiológicos microrganismos denominados periodontopatógenos, dentre eles o Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans), anteriormente chamado Actinobacillus actinomycetemcomitans, que em associação às alterações na resposta imune e inflamatória decorrentes da diabetes, poderá causar maior reabsorção do osso alveolar precocemente em crianças. A identificação precoce destes agressores poderá ser extremamente útil para a instituição de medidas preventivas e terapêuticas que possam inibir ou minimizar os efeitos nocivos da IDDM e suas conseqüências para a cavidade bucal. Para este fim, métodos moleculares de investigação estão sendo cada vez mais utilizados, destacando-se a Reação em Cadeia da Polimerase em Tempo Real (Real-Time PCR) com alta especificidade e sensibilidade para detectar e quantificar microrganismos, mesmo em pequeno número e em meios, até então, pouco explorados como a saliva. Por fim, a utilização de um antimicrobiano seguro, que possa ser aplicado topicamente por meio da escovação dentária, como o metronidazol 25% na forma de gel, poderia reduzir ou eliminar o A. actinomycetemcomitans evitando a progressão da doença periodontal. Assim, este estudo foi realizado para observar a presença do A. actinomycetemcomitans antes e após o uso do gel de metronidazol 25% uma vez ao dia, em substituição a uma das escovações diárias. Avaliou também a influência deste protocolo de tratamento nos índices de placa, gengival e profundidade de sondagem em 32 crianças, na faixa etária de 3 a 12 anos de idade, divididas em dois grupos: diabéticos tipo I (D) e não diabéticos (ND). Para avaliação da presença do A. actinomycetemcomitans foi utilizado o método da Real-Time PCR. Os resultados obtidos sugerem que o gel de metronidazol 25%, aplicado segundo o protocolo estabelecido neste trabalho foi efetivo para a redução dos índices de placa, gengival e do A. actinomycetemcomitans, no entanto, pareceu não atuar sobre a profundidade de sondagem. Os dados obtidos sugerem que, ainda que a ocorrência da bactéria nos indivíduos avaliados tenha sido baixa e a diferença entre o grupo diabéticos e não diabéticos tenha restringido-se apenas à profundidade de sondagem, o gel estudado demonstrou ser promissor na prevenção da doença periodontal em crianças diabéticas, havendo necessidade da realização de mais estudos clínicos randomizados. / Type I Diabetes mellitus (IDDM) is a metabolic disease characterized by deficiency on the insulin production, causing great systemic alterations, including at the oral cavity. Periodontal disease is more aggressive in diabetic patients, even during the childhood, and presents as etiological microorganisms the Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans), formerly Actinobacillus actinomycetemcomitans. This microorganisms in association to alterations in the immune and inflammatory answers caused by diabetes, can promote a larger and early alveolar bone resorption even in children. So, the early identification of these aggressors could be extremely useful for the institution of preventive and therapeutic measures in order to inhibit or minimize the noxious effects of IDDM and their consequences in the oral cavity. Aiming this early identification, molecular biology methods of investigation are being used more frequently, pointing out the Real Time Polymerase Chain Reaction (Real-Time PCR), which presents high specificity and sensibility to detect and to quantify microorganisms, even in small number and in different media little explored like saliva. The use of a safe topical antibiotic, such as metronidazole 25% gel, which used in association with dental brushing, could reduce or eliminate A. actinomycetemcomitans, avoiding the progression of the periodontal disease. This study evaluated the presence of A. actinomycetemcomitans before and after the use of metronidazole 25% gel once a day, in substitution to one of the daily teeth brushing. It also evaluated the influence of this treatment protocol on the plaque, gingival and probing depth indexes. Thirty-two children, aging from 3 to 12 years were included in this study and they were divided into two groups: type I diabetic (D) and no diabetic (ND). Real-Time PCR methods were used to evaluate the presence of A. actinomycetemcomitans. The obtained data suggest that metronidazole 25% gel, applied according to the established protocol in this study, effectively reduced plaque and gingival indexes and the number of A. actinomycetemcomitans. However, no influence was observed regarding the probing depth. The obtained data suggest that, although the number of bacteria has been small and the difference between the D and ND groups was not observed only regarding probing depth, the studied antibiotic gel demonstrated to be promising in preventing periodontal disease in diabetic children. More randomized clinical trials are necessary for a final conclusion.

Obligat anaerob wachsende Bakterien sind an einer Vielzahl von Infektionen beteiligt. Dabei ist Bacteroides fragilis einer der wichtigsten opportunistischen Erreger unter den Anaerobiern. Bei Verdacht auf eine Infektion durch obligate Anaerobier muss nach Materialentnahme für die mikrobiologische Diagnostik unverzüglich eine kalkulierte Therapie eingeleitet werden. Oft ist eine chirurgische Therapie notwendig, die ebenso wie eine adäquate Antibiotikatherapie entscheidend für den Verlauf der Erkrankung ist. Wichtige Substanzen für eine Therapie bei Infektionen mit Beteiligung von B. fragilis sind Clindamycin, Imipenem, Metronidazol und Piperacillin/Tazobactam. Um Aussagen zur in vitro Wirksamkeit dieser Antibiotika gegenüber obligaten Anaerobiern treffen zu können, wurden in der vorliegenden Arbeit die Aktivitäten von verschiedenen Konzentrationen des jeweiligen Antibiotikums auf das Wachstum von sensiblen und resistenten B. fragilis Stämmen mittels Absterbekinetik untersucht. In Abhängigkeit von der zuvor ermittelten minimalen Hemmkonzentration des jeweiligen Antibiotikums wurden die Stämme in 2 Gruppen eingeteilt. Die erste Gruppe umfasst alle Stämme mit einer MHK ≤ 8 µg/ml. In der zweiten Gruppe sind die Stämme mit einer MHK > 8 µg/ml zusammengefasst. Die einzelnen Stämme wurden mit einem Vielfachen der minimalen Hemmkonzentration (MHK) beziehungsweise einem Vielfachen der im menschlichen Blutplasma maximal erreichbaren Konzentration (Cmax) des jeweiligen Antibiotikums inkubiert und die Bakterienkonzentration zu definierten Zeitpunkten ermittelt. Dadurch können sowohl die Wirksamkeit unterschiedlicher Antibiotikakonzentrationen als auch verschiedene Antibiotikaklassen miteinander verglichen und Aussagen zu Empfehlungen für kalkulierte Therapien getroffen werden.

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. Several agents are under consideration for the disinfection and conditioning phases of this therapy. Triple antibiotic paste (TAP, i.e. equal parts of ciprofloxacin, metronidazole, minocycline) is used for canal disinfection and 17% EDTA solution is used for dentin conditioning. However, TAP and EDTA cause demineralization and their effect on surface loss and surface roughness of radicular dentin during regenerative procedures has not been quantified. Surface loss may be correlated with reduced tooth strength and surface roughness may be correlated with stem cell attachment. Objectives: The aim of this in vitro study was to quantitatively investigate the surface loss and surface roughness on human radicular dentin after treatment with two concentrations of TAP followed by EDTA. Materials and Methods: Human radicular dentin specimens were prepared from extracted human anterior teeth and randomized into six experimental groups. Group 1: saline control; Group 2: 17% EDTA; Group 3: TAP 1 mg/mL; Group 4: TAP 1 mg/mL and 17% EDTA; Group 5: TAP 1,000 mg/mL; Group 6: TAP 1,000 mg/mL and 17% EDTA for 5 minutes. After TAP is applied to Groups 3-6, all groups were incubated for 4 weeks. Then, groups 2, 4, and 6 were treated with EDTA for 5 minutes. Dentin surface loss (μm) and surface roughness (Ra, μm) were quantified after various treatments using non-contact and contact profilometry, respectively. Data were analyzed by one-way analysis of variance (α = 0.05) Hypothesis: It was hypothesized that there would be a significant difference in surface loss or surface roughness between at least two treatment groups. Results: All treatment groups showed significantly higher surface loss compared to untreated control. Dentin treated with 1g/mL TAP caused significant increase in surface loss and surface roughness compared to dentin treated with 1 mg/mL TAP. However, only 1g/mL TAP treated dentin showed significantly higher surface roughness compared to untreated control. The use of EDTA after both concentrations of TAP did not have significant additive effect on surface loss and surface roughness of dentin. Conclusion: The use of 1 mg/mL TAP can minimize surface loss and surface roughness of radicular dentin compared to higher concentrations. The use of EDTA after TAP may not cause additional surface loss and surface roughness of dentin.

The aim of presented Diploma Thesis was to study an electrochemical behavior of nitroimidazole drugs metronidazole and ornidazole and to find optimal conditions for their voltammetric determination at a mercury meniscus modified silver solid amalgam electrode using DC voltammetry (DCV) and differential pulse voltammetry (DPV). Voltammetric behavior of selected drugs was investigated in dependence on the pH of the medium used (realized using a Britton-Robinson buffer (BR buffer)) and a mechanism of the reduction of both drugs was investigated using cyclic voltammetry (CV). The optimum medium for voltammetric determination of studied nitroimidazole drugs at the m-AgSAE in a region of cathodic potentials was found to be the BR buffer of pH 8.0. Then, the concentration dependences were measured in this optimum medium in the concentration range from 2·10-7 mol/L to 1·10-4 mol/L. The limits of quantification (LQs) for both metronidazole and ornidazole were found in the concentration order of 10-7 mol/L by using DCV and DPV at the m-AgSAE. The applicability of the newly developed voltammetric methods of the determination of nitroimidazole drugs was verified on the model samples of drinking and river water, with LQ ≈ 2·10-7 mol/L for both DC voltammetry and differential pulse voltammetry at the m-AgSAE....

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.

Selon les dernières estimations de l'OMS, on enregistre chaque année dans le monde 498.9 millions de nouveaux cas d'infections sexuellement transmissibles (IST) dont 276.4 millions sont dus au parasite Trichomonas vaginalis (T. vaginalis). Au niveau du tractus génital, la colonisation et l’irritation de la muqueuse vaginale par T. vaginalis favorisent la survenue de complications infectieuses. Ces infections associées peuvent conduire à des infections chroniques et avoir à terme des conséquences graves (stérilité, rupture prématuré du placenta, mort prématurée du nourrisson). De plus, ces infections vaginales représentent des facteurs qui favorisent les infections par le Virus d’Immunodéficience Humaine (VIH-1).A l’heure actuelle, la lutte contre ce type d’infections consiste à agir tant au niveau curatif, que préventif. Ainsi, l’objectif de ce projet est de développer de nouvelles formulations pour la prévention et le traitement des pathogènes qui colonisent les muqueuses vaginales. Dans ce contexte, la formulation que nous proposons est composée de metronidazole inclut dans un hydrogel thermogélifiant à base de pluronic® F127 et de chitosane. Il a été montré que cet hydrogel conserve ces propriétés physiques à une température physiologique même après dilution dans les fluides vaginaux. Ces hydrogels sont stables et permettent une libération prolongée du metronidazole. La formulation n’a montré aucune toxicité envers les cellules HeLa ni envers la muqueuse vaginale porcine. L’efficacité de cette formulation a été prouvée envers T. vaginalis et présente un effet protecteur envers les cellules HeLa en présence de T. vaginalis. L’ensemble des résultats suggère donc la capacité́ de cette formulation à constituer une double barrière, physique et pharmacologique, protectrice de la muqueuse vaginale vis-à-vis de T. vaginalis. / According to the latest WHO estimates, 498 millions of new cases of sexually transmitted infections (STIs) are recorded annually in the world, including 276.4 million due to the parasite Trichomonas vaginalis (T. vaginalis). In the genital tract colonization and irritation of the vaginal mucosa by T. vaginalis promote the occurrence of infectious complications. Associated infections can lead to chronic infections and eventually have serious consequences (infertility, premature placental abruption, premature death). In addition, these vaginal infections can promote infection by Human Immunodeficiency Virus (HIV-1).Currently, the fight against these infections is to act at curative and preventive level. Thus, the objective of this project is to develop new formulations for the prevention and treatment of pathogens that colonize the vaginal mucosa. In this context, we propose a formulation composed of metronidazole and chitosan include in a thermogelling hydrogel of pluronic F127®.It was shown that the hydrogel retains its physical properties even at a physiological temperature and after dilution in the vaginal fluids. These hydrogels are stable and allow a sustained release of the metronidazole. The formulation showed no toxicity against HeLa cells or porcine vaginal mucosa. The effectiveness of this formulation has been proven against T vaginalis and has a protective effect on HeLa cells in the presence of T. vaginalis. The overall results therefore suggest the ability of this formulation to form a double barrier, physical and pharmacological, than protect vaginal mucosa against T. vaginalis.

Hintergrund: Zahlreiche Studien haben den therapeutischen Nutzen von systemischem Antibiotika in der Behandlung schwerer Parodontitis gezeigt. Bisher ist allerdings noch nicht geklärt, welches antibiotische Behandlungkonzept das Geeignetste ist. Daher sollen in einer randomisierten, klinischen Blindstudie zwei verschiedene, systemische Antibiotika adjuvant zur konventionellen, instrumentellen Behandlung von Patienten mit rapid progressiver Parodontitis (RPP) miteinander verglichen werden. Material und Methode: 33 Patienten mit klinisch und radiologisch gesicherter RPP-Diagnose wurden auf 2 Gruppen verteilt: (1) AM-Gruppe (n=17): 500 mg Amoxicillin und 250 mg Metronidazol (3*/ Tag - 10 Tage), (2) D-Gruppe (=16) 200mg Doxycyclin am 1.Tag und 100mg Doxycyclin 13 Tage. Zu Beginn erhielten alle Patienten 3* eine professionelle Zahnreinigung, und anschlie§end Scaling und Wurzelglättung unter Lokalanästhesie in 2 Sitzungen. 3 Monate später wurde ein Recall und die Antibiose durchgeführt. Im Abstand von jeweils 3 Monaten erfolgten 2 weitere Recallsitzungen. Nach erfolgreicher Mundhygieneinstruktion und zu allen Recallsitzungen wurden alle klinischen Parameter wie Taschentiefe, relatives Attachmentlevel und das Bluten bzw. Pus nach Sondieren mit der Florida probe eruiert. Die Bestimmung 8 verschiedener Parodontalpathogene wurde mit dem DNS-Sondentest von Meridol durchgeführt. Die mikrobiologischen Proben wurden mit sterilen Papierspitzen an den vier tiefsten Taschen vor der Antibiose und zu den anschlie§enden Recalls entnommen und mit der Gensondentechnik im Labor der Wybert GmbH elmex Forschung, Lörrach, analysiert. Zur Bestimmung des IL-1-Genpolymorphismus wurde venöses Blut in der 1. Sitzung abgenommen. Die Auswertung erfolgte mit dem GenoType(R) PRTest (Hain Diagnostika GmbH). Ergebnisse: Die klinischen Parameter zeigen sowohl durch die konservative als auch durch die antibiotisch adjuvante Therapie eine signifikante klinische Verbesserung (p / Background: Several studies have shown a therapeutical benefit from systemic antibiotics in the treatment of severe periodontitis. However, it has not yet been layed down which concept of antibiotic treatment is the best. Therefore the purpose of this study is to compare two different systemic antibiotics adjunctive to a conventional, mechanical treatment of patients with rapidly progressive periodontitis (RPP) in a randomised, blinded, clinical trial. Material and methods: 33 patients with a clinically and radiographically confirmed diagnosis of RPP were distributed in two groups: (1) AM-group (n=17): 500 mg amoxicillin and 250 mg metronidazole (3*/ d - 10days), (2) D-group (=16) 200mg doxycyclin on the 1st day and 100mg doxycyclin for 13days. In the beginning the patients received 3* professional tooth cleaning, and subsequently scaling and root planning under local anaesthesia in two sessions. 3 months later a recall visit and the antibiotic regimen were carried out. In 3 months-intervals another 2 recall visits were performed. After successfull oral hygiene instructions and during all recall visits all clinical parameters like pocket depths, relative attachment level, and bleeding and pus on probing were evaluated with the Florida probe. The determination of 8 different periodontal pathogens was performed with the DNS-Sondentest of Meridol. Before the antibiotic treatment and during the following recall visits the microbiological samples were taken from the 4 deepest pockets with sterile paper points and analysed by PCR-technique in the laboratory of Wybert GmbH elmex Forschung, Lörrach. To determine the IL-1 genetic polymorphism venous blood samples were taken in the first session. The analysis was done by GenoType(R), PRTest (Hain Diagnostika GmbH). Results: The clinical parameters show a significant clinical improve by the conservative as well as by the adjunctive antibiotic treatment (p

Die systemische Verabreichung von Amoxizillin/Metronidazol (AM) als Zusatz zu Scaling/Root planing (SRP) in der Behandlung der generalisierten Aggressiven Parodontitis (gAP) führt zu guten klinischen und mikrobiologischen Ergebnissen. Die lokale antiseptische Zusatzmedikation mit Chlorhexidin in einem Controlled-Delivery-Device (PerioChip, PC) verbessert das Ergebnis von SRP in der Behandlung der Chronischen Parodontitis. Die Anwendung in der Behandlung der gAP ist bisher noch nicht untersucht worden. Ziele: Der Effekt von PC als Zusatz zu SRP in der Therapie der gAP wurde untersucht. Die Wirksamkeit wurde mit der Standardmedikation AM verglichen. Neben klinischen Parametern wurde die Konzentration des Entzündungsmarkers Calprotectin in der Sulkusflüssigkeit (SF) bestimmt. Material/Methode: 36 gAP-Patienten (18/Gruppe, 35+/-4 Jahre) wurden mit SRP und randomisiert entweder mit AM oder PC behandelt. Zur Baseline, 3 und 6 Monate nach SRP wurden die klinischen Parameter PD, CAL, BoP, Pus erhoben sowie SF-Proben tiefer und flacher Referenzstellen entnommen. Die Calprotectin-Konzentration in der SF wurde mittels ELISA bestimmt. Ergebnisse: 3 Monate nach SRP zeigten beide Gruppen signifikante Verbesserungen der klinischen Parameter, wobei noch keine Unterschiede zwischen den Gruppen bestanden. Während die AM-Gruppe stabil blieb, verschlechterten sich mehrwurzelige Zähne und tiefe Referenzstellen der PC-Gruppe wieder signifikant. Nach 6 Monaten wies die AM-Gruppe signifikant mehr CAL-Gewinn und PD-Reduktion auf. Pus war nur noch in der PC-Gruppe nachweisbar. Die Calprotectin-Konzentration war zwar in beiden Gruppen signifikant gesunken, Unterschiede zwischen den Gruppen bestanden jedoch aufgrund hoher Standardabweichungen nicht. Schlussfolgerung: AM zeigte eine bessere klinische Wirksamkeit und Langzeitstabilität als PC. Aufgrund großer interindividueller Variabilität spiegelte die SF-Konzentration von Calprotectin die klinischen Unterschiede nicht wider. / Adjunctive systemic administration of amoxicillin/metronidazole (AM) in generalized aggressive periodontitis (gAP) therapy results in good clinical and microbiological outcome. Adjunctive use of chlorhexidine within a controlled-delivery-device (PerioChip, PC) improves the outcome of scaling/root planing (SRP) in chronic periodontitis therapy. Its effect in the treatment of gAP has not been evaluated. Aims: The effect of adjunctive use of PC in the treatment of gAP was investigated. Efficacy of PC was compared to the standard treatment with AM. Clinical parameters and the concentration of the inflammation marker calprotectin within gingival crevice fluid (GCF) were measured. Material/methods: 36 gAP patients (18/group, 35+/-4 years) were treated by SRP either AM or PC. Clinical parameters PD, CAL, BoP and Pus were recorded at baseline, 3 and 6 months after therapy. GCF was sampled at deep and shallow reference sites and the concentration of calprotectin was measured by ELISA. Results: Both groups showed significant improvements of clinical parameters 3 months after SRP, however differences between groups were not significant. While the AM-group remained clinically stable, multirooted teeth and deep reference sites of the PC-group showed significant deterioration again. 6 months after SRP, the AM-group showed significant more CAL gain and PD reduction. Pus was detectable in the PC group only. The concentration of calprotectin in GCF had significantly decreased in both groups; however differences between groups were not significant due to high standard deviations. Conclusion: AM showed higher efficacy in terms of clinical treatment outcome and long-term stability than PC. Due to high interindividual variability, GCF-concentrations of calprotectin failed to reflect clinical differences.

<p>Over three million infections were reported in the United States of America in 2019. These infections were caused by either antibiotic-resistant pathogens or <i>Clostridioides difficile</i> and resulted in more than 50,000 deaths. Unfortunately, antibacterial agents are rapidly losing their ability to treat infections and the process of discovering new antibiotics is too slow to cope up with bacterial evolution. Repurposing FDA-approved drugs of well-studied safety, pharmacology and pharmacokinetics represents a faster alternative method of antibacterial drug discovery. Repurposing is more successful and less depleting method of drug discovery than classical de novo method in regard to both cost and time. In the following studies, two major pathogens are targeted, vancomycin-resistant <i>Enterococcus</i> (VRE) and <i>C. difficile</i>. Both bacteria are more prevalent in healthcare settings were more vulnerable population of elderly and immunocompromised individuals reside. In addition, healthcare settings are usually associated with higher frequency of receiving antibiotics which in turn, compromises the integrity of normal microbiota responsible for protection against invading pathogens. Furthermore, hospital stays are associated with exposure to bacterial shedding from other patients. Our aim was to identify FDA-approved drugs with novel ability to eradicate these two bacterial pathogens in the gastrointestinal tract (GIT). Notably, the GIT is considered the actual site of infection in case of <i>C. difficile while it is only a transition site for VRE where the bacteria colonize before causing true infections in other tissues. Studies against both bacteria started with an <i>in vitro</i> screening of FDA-approved drugs and clinical molecules to identify potential candidates for further investigation.</i></p><p><i>For VRE, two drugs where identified with potent inhibitory activity and favorable pharmacokinetic profiles, auranofin and ebselen. Auranofin was approved in the 1960s for the treatment of rheumatoid arthritis due to its anti-inflammatory activity. Auranofin was found to exert potent bacteriostatic activity against both vancomycin-sensitive and vancomycin-resistant <i>Enterococcus</i> strains (minimum inhibitory concentration against 90% of the strains, MIC90 = 1 µg/mL). In addition, bacteria could not develop resistant mutants against auranofin upon prolonged exposure. On the other hand, ebselen is an organoselenium compounds currently in clinical trials for several indications. Similarly, ebselen was found to be a potent inhibitor of VRE growth (MIC90 = 2 µg/mL). In addition, ebselen successfully inhibited bacterial biofilm formation and eradicated mature biofilms. In a mouse model of VRE colonization, both drugs inhibited bacterial shedding and reduced bacterial counts in the GIT of the colonized animals.</i></p><p><i>For <i>C. difficile</i>, auranofin was also found to exert potent inhibitory activity against bacterial growth (MIC90 = 2 µg/mL), toxin production and spore formation. Additionally, it was beneficial in protecting colon cells against <i>C. difficile</i> toxin-induced inflammation. Further, auranofin was found to not promote growth of VRE as seen with the current anticlostridial agents. In addition to auranofin, two more antiprotozoal drugs were found to potently inhibit <i>C. difficile</i> growth, ronidazole and secnidazole. Both drugs are 5-nitroimidazoles approved for human (secnidazole) or veterinary (ronidazole) applications. Secnidazole and ronidazole halted <i>C. difficile</i> growth at very low concentrations (MIC90 = 0.5 and 0.125 µg/mL, respectively). Furthermore, both drugs were superior to metronidazole in bacterial killing and had favorable activities against protective gut microbiota. In addition, they demonstrated efficient protection to mice in a <i>C. difficile</i> infection model. </i></p><p><i>Overall, several drugs were presented to possess favorable activities against <i>C. difficile</i> or VRE. These drugs merit more evaluation as potential candidates for the treatment of infection caused by either bacteria. </i></p><div><i><br></i></div>