Indiana University-Purdue University Indianapolis (IUPUI) / Introduction: Regenerative endodontic procedures require adequate disinfection of immature teeth with necrotic pulps. Regeneration endodontic procedures have been shown to increase width and length of dentin after disinfection of the root canal system with various antibiotic pastes such as double antibiotic paste (DAP). DAP is composed of an equal ratio of metronidazole and ciprofloxacin. After the root canal system is disinfected with DAP, it is later flushed out with 17-percent EDTA. There is a need for a radiopaque component in the DAP to facilitate proper placement. Following disinfection with DAP, a residual antibacterial effect is formed in dentin. It is not known if this effect is modified by making DAP radiopaque. Objectives: The residual antibacterial effects of a radiopaque double antibiotic paste against a bacterial isolate obtained from an immature tooth with necrotic pulp on radicular dentin will be explored utilizing various strengths of DAP (1 mg/mL, 10 mg/mL, and 25 mg/mL) after 1 week and 4 weeks. Materials and Methods: Dentin samples of 4x4-mm will be prepared from previously extracted human posterior teeth. The samples will be assigned to seven treatment groups in a random fashion (G1 will be treated with 25-, G2-10, and G3-1 mg/mL of radiopaque DAP. G4 will be treated with the radiopaque filler without DAP. G5 will be treated with Ca(OH)2 and G6 sterile water with bacterial biofilm, and G7 will be sterile water). The groups will be treated for both 1 week 4 weeks. These samples will then be stored in a phosphate buffered saline (PBS) solution for 1 week and then inoculated with the cultured bacterial isolate from an immature tooth with necrotic pulp. The specimens will be incubated for three weeks to permit adequate formation of a biofilm. The biofilm will be detached, diluted and spirally plated onto blood agar plates and incubated for a total of 48 hours in 5-percent CO2 at 37°C. The number of CFUs/mL will be counted using an automated colony counter. A two way ANOVA and Fisher’s Protected Least Significant Differences test using 5-percent significance level will be used to evaluate the resulting data. Expected outcome: A residual antibacterial effect will be observed on radicular dentin samples when treated with radiopaque DAP. Conclusion: Using a radiopaque DAP that provides residual antibacterial effects, further awareness into regenerative endodontic procedures will be gained leading to alterations in treating such cases. / 2020-06-30

No description available.

京都大学 / 新制・課程博士 / 博士(農学) / 甲第25329号 / 農博第2595号 / 新制||農||1105(附属図書館) / 京都大学大学院農学研究科応用生命科学専攻 / (主査)教授 渡邊 隆司, 教授 阪井 康能, 教授 飛松 裕基 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DFAM

Diss. (sammanfattning) Linköping : Linköpings universitet, 2005. / Härtill 5 uppsatser.

Diss. Linköping : Linköpings universitet, 2007.

Le travail présenté dans ce manuscrit inclut la synthèse organique des différents types de calixarènes, l'étude de leurs propriétés optiques, des simulations théoriques pour déterminer leurs conformations favorables et leurs utilisations pour stabiliser des nanoparticules. Des nanoparticules d’argent, d’or, de platine et des nanoparticules bimétalliques (Ag-Au) ont été synthétisées en utilisant par réduction radiolytique ainsi que la synthèse la photochimique. Ces nanoparticules sont stabilisées en utilisant des calixarènes et divers polymères. Les nanomatériaux ont été caractérisés par spectroscopie d’absorption UV-Visible et spectroscopie de fluorescence et par des observations en microscopie électronique en transmission. Comme les nanoparticules métalliques sont connues pour leurs applications dans divers domaines, des propriétés antibactériennes de nanoparticules d'argent et des propriétés électrocatalytiques des nanoparticules d'or ont été testées. / The work presented in this manuscript includes the organic synthesis of different types of calixarenes, the study of their optical properties, computational studies for determination of their favourable conformations and their use in the stabilisation of nanoparticles. Silver, gold, platinum and bimetallic (Ag-Au) nanoparticles were synthesised using radiolytic reduction as well as photochemical method. These nanoparticles were stabilised by calixarenes and also other ligands which included several polymers. The nanomaterials were characterised using UV-Visible absorption and fluorescence spectroscopy and transmission electron microscopy (TEM) measurements. As metal nanoparticles are known for their applications in various fields, the antibacterial properties of silver nanoparticles and the electrocatalytic properties of gold nanoparticles were tested.

Introdução: Reação Adversa a Medicamento (RAM) é qualquer resposta prejudicial ou indesejável e não intencional que ocorre com medicamentos em doses normalmente utilizadas no homem para profilaxia, diagnóstico, tratamento de doença ou para modificação de funções fisiológicas. Atualmente, representa uma das principais causas de morbidade e mortalidade na área da saúde. Objetivo: Analisar as reações adversas a medicamentos e fatores associados em pacientes ortopédicos tratados com antibióticos. Método: Coorte prospectiva conduzida com 273 pacientes ortopédicos internados no Instituto Nacional de Traumatologia e Ortopedia, Rio de Janeiro, Brasil. A coleta de dados ocorreu nos anos de 2012 e 2013, por meio de instrumento composto por variáveis demográficas-clínicas e terapia medicamentosa. Para identificação das RAMs realizou-se o monitoramento ativo, composto de: entrevista, análise de prontuários e exames laboratoriais. As RAMs consideradas graves foram analisadas por meio do formulário do Instituto Catalão de Farmacologia, Espanha. Na análise dos dados utilizaram-se os testes Mann-Whitney, Qui-Quadrado, exato de Fisher e regressão logística, com significância de p 0,05. Resultados: A incidência de RAM foi de 41%. O grupo com RAM apresentou maior média de idade (43,3; DP 10,9), tempo de internação (72,7; DP 40,9) e número de medicamentos concomitantes (13,2; DP 4,1). Os fatores associados foram número de medicamentos, uso de antimicobacteriano (OR 2,44; IC 1,3944,270) e carbapenêmicos (OR 2,38; IC 1,167 4,872). Identificaram-se 466 RAM, cuja maioria (67,1%) foi classificada como leve. No grupo de pacientes com RAMs graves identificaram-se leucopenia (46,6%), insuficiência renal aguda (40%) e hepatite medicamentosa (26,6%). Os antibióticos foram os principais medicamentos suspeitos de causar as RAMs graves (76,4%), sendo os mais frequentes (23,5%) formados pela tríade: amicacina + vancomicina + piperacilina com tazobactam. Conclusão: A incidência de RAM é maior quando se incorpora ao serviço de farmacovigilância a técnica de monitoramento contínuo dos pacientes hospitalizados e se utiliza a analise de exames laboratoriais como preditores para suspeitas de RAMs potencialmente graves / Introduction: Adverse Drug Reaction (ADR) is any noxious, undesired or unintended response which occurs in the use of normal dosages of drugs for prophylaxis, diagnosis, treatments or for modifying physiologic functions. Nowadays, ADR represents one of the main causes of morbidity and mortality in the health service area. Objective: To analyze the occurrence of adverse reaction to drugs and factors related to orthopedic patients treated with antibiotics. Method: The prospective cohort study was conducted in 273 orthopedic patients hospitalized at the Brazilian Institute of Traumatology and Orthopedics in Rio de Janeiro. The data collection was made during the years 2012 and 2013, using instruments composed by demographic-clinical variables and drug therapies. With the purpose of identifying occurrences of ADRs, during active monitoring, interviews were conducted, medical charts and exams were analyzed. In addition, the occurrence of ADRs considered harmful was analyzed by using a form provided by the Catalan Institute of Pharmacology, Spain. In the study of the data collected, was made use of Mann-Whitney tests, Chi-Squared test, Fishers exact test and logist regression, with p-value 0,05. Results: The occurrence of ADRs was of 41%. This group was composed by individuals with major age rage (43,3, SD 10,9), major time spent hospitalized (72,7; SD 40,9), and quantity of concurrent drugs used (13,2; SD 4,1). Also, the related factors were the number of drugs, the usage of Antimicobacterial agents (OR 2,44, CI 1,394-4,270) and Carbapenemases (OR 2,38; CI 1,167 4,872). During the study, there were identified 466 ADRs, and the majority (67,1%) was classified as low-grade. Additionally, in the group of patients with harm adverse reactions, it was possible to identify leukopenia (46,6%), acute kidney failure (40%) and drug-induced hepatitis (26,6%). The antibiotics were the main drugs suspected to be the cause of potentially harmful ADRs (76,4%), being the most frequent (23,5%) formed by the triad: amikacin + vancomycin + piperacillin-tazobactam. Conclusion: The occurrence of ADRs is higher when the practice of continuous monitoring of hospitalized patients is incorporated to the pharmacovigilance service, and the analyzes of lab exams are used as predictors for the suspicion of potentially harmful ADRs

O objetivo do presente estudo clínico foi compreender o efeito do uso prévio de agentes antimicrobianos na diversidade e a estrutura do microbioma procariótico de saliva, biofilme supragengival e canal radicular de dentes com infecção endodôntica aguda. Realizaram-se coletas microbiológicas de saliva (S), biofilme supragengival (BS) e canal radicular (CR) de pacientes que não utilizaram antibióticos (G1: n=6) e de pacientes que utilizaram antibióticos (G2: n=6). Para a caracterização das comunidades de procariotos por meio de sequenciamento de alto rendimento, foram produzidos pools de seis amostras para cada um dos sítios. A região hipervariável V3-V4 do gene 16S rRNA foi amplificada e a plataforma Illumina MiSeq foi empregada para análise das sequências geradas. Foram determinadas a presença e abundância relativa das unidades taxonômicas operacionais (OTUs) em cada amostra. Procedeu-se a análise de alfa-diversidade para cada amostra, considerando-se as métricas de Simpson, dominância, estimativa de riqueza de Chao-I e o Índice de Shannon. Os valores obtidos foram comparados por meio de testes estatísticos. Para a análise dos índices de beta-diversidade, empregou-se o método de agrupamento UPGMA, com jackknifing e método de comparação UniFrac com peso. A representação gráfica tridimensional da beta-diversidade foi realizada por meio de análise de coordenadas principais. A técnica de PCR gene específico foi empregada para determinar a presença de genes relacionados à resistência bacteriana para agentes beta-lactâmicos (blaTEM, blaZ, ampC, mecA), macrolídeos (ermB, ermC, mefA), tetraciclinas (tetM, tetQ, tetW), lincosamidas (lnuB, lsaB) e vancomicina (vanA, vanD, vanE). A similaridade para a presença/ausência de genes de resistência nas amostras de S, BS e CR em G1 e G2 foi determinada por meio de coeficiente de agrupamento, utilizando-se o método UPGMA com distância Euclidiana. Todos os pacientes apresentavam infecção endodôntica aguda, caracterizada pela presença de dor espontânea, necrose pulpar e dor à percussão vertical. Aumento de volume foi observado em 8/12 pacientes. Os pacientes do Grupo 2 utilizaram beta-lactâmicos previamente à consulta (amoxicilina = 5; cefalexina = 1). Há predomínio de integrantes do domínio Bactéria em todas S, BS e CR. Archaea pertencentes ao gênero Methanobrevibacter foram encontradas apenas em amostras de CR, constituindo menos de 1% do total de OTUs (G1-CR = 0,319%; G2-CR = 0,014%). Há predomínio de bactérias dos filos Firmicutes e Bacteroidetes em amostras de S, BS e CR. Há redução intensa no percentual de OTUs pertencentes ao Filo Firmicutes em amostras de saliva, quando antibiótico foi utilizado (G1-S = 75,371; G2-S = 35,242). Comportamento oposto ocorreu neste ecossistema para integrantes do Filo Bacteroidetes (G1-S = 12,657; G2-S = 33,947). Tanto em G1 quanto em G2, bactérias do gênero Streptococcus predominam em amostras de S e BS. Em canais radiculares, maiores percentuais de OTUs foram observados para os gêneros Porphyromonas e Prevotella. As métricas de alfadiversidade indicam que o uso prévio de antimicrobiano parece oportunizar o estabelecimento de espécies antes menos abundantes, especialmente em saliva (dominância: G1-S>G2-S; índice de Shanon: G1-S<G2-S; índice de Simpson: G1- S<G2-S; índice de Chao-1: G1-S<G2-S). A análise de beta-diversidade mostra proximidade entre G1-BS e G2-BS; há distanciamento entre G1-S e G2-S. As amostras G1-CR e G2-CR estão mais distantes de S e BS, sugerindo maior seleção imposta pelo ecossistema do CR aos procariotos. Os genes de resistência mais frequentemente detectados foram tetM, tetQ, tetM, ermB e mefA. Não foram detectados genes vanA, vanD, vanE, blaZ, mecA, lnuB e ermC. O gene ermB foi frequentemente detectado em amostras de S, BS e CR em ambos os grupos. Em pacientes que não utilizaram antibiótico, o gene tetM e o gene tetQ foram detectados simultaneamente em S, BS e CR (tetM = 4/6; tetQ = 3/6). A análise multivariada não demonstrou nível de agrupamento alto entre amostras de um mesmo paciente, de um mesmo ecossistema, ou de um mesmo grupo. A partir dos resultados do presente estudo, observou-se que a utilização de agente antimicrobiano betalactâmico parece alterar parâmetros composicionais de comunidades de procariotos na cavidade bucal. Entretanto, particularidades relativas a cada ecossistema podem modular a extensão deste efeito, parecendo ser mais intensos em amostras de S do que em BS e CR. / The present clinical study aimed to assess the effect of antibiotics over the diversity and structure in prokaryotic communities of saliva, supragengival biofilm and root canal of teeth with acute primary infections. Samples of saliva (S), supragengival biofilm (BS) and root canal of teeth with acute primary infections (CR) were collected from patients, and were grouped according with the previous use of antibiotic (G1 = no antibiotics; G2 = antibiotics). Pooled samples for each community were evaluated. DNA sequencing was performed with MiSeq (Illumina). The V3-V4 hypervariable region from the 16S rRNA gene was amplified. The presence and relative abundance of the operational taxonomic units (OTUs) was determined for each sample. Alpha-diversity analysis was performed with the Simpson’s index, dominance, Chao-1 richness index and Shannon’s index. Statistical analysis was carried out to compare their values for each community.Beta-diversity was computed through UPGMA clustering and jackknifing. The principal coordinate analysis employed weighted UniFrac. Gene-specific PCR was employed to detect resistance genes to lactamics (blaTEM, blaZ, ampC, mecA), macrolides (ermB, ermC, mefA), tetracyclines (tetM, tetQ, tetW), lincosamides (lnuB, lsaB) e vancomycin (vanA, vanD, vanE). The UPGA clustering analysis with Euclidean distance was applied to investigate the existence of similar groups of samples. A dendrogram was constructed to show the arrangement of the sample groups produced by clustering. All the patients had primary acute endodontic infections, with spontaneous pain, pulp necrosis and tenderness on percussion. Swelling was observed for 8 out of 12 patients. Patients from G2 had lactamics before the urgency appointment (amoxicillin = 5; cephalexin = 1). Bacteria were predominant in S, BS and CR samples. Archaea belonging to the genus Methanobrevibacter were only detected in RC samples and comprised less than 1% of all the OTUs G1-CR = 0.319%; G2-CR = 0.014%). The great majority of the detected OTUs in S, BS, and CR belonged to the phyla Firmicutes and Bacteroidetes. Reduction in the percentage of Firmicutes was observed in G2-S (G1-S = 75.371%; G2-S = 35.242%). A distinct behavior was demonstrated by the Bacteroidetes (G1- S = 12.657%; G2-S = 33.947%). Components belonging to the genus Streptococcus were predominant in S and BS, for both G1 and G2. CR harbored high percentage of species belonging to the genus Porphyromonas and Prevotella. The alpha-diversity indexes demonstrated that the G2-S had an increase in low abundant species (dominance: G1- S>G2-S; Shanon index: G1-S<G2-S; Simpson index: G1-S<G2-S; Chao-1 index: G1-S<G2- S). Beta-diversity showed that G1-BS and G2-BS had close spatial distribution. G1-CR and G2-CR were more distant from S and BS samples. The RC may promote a most intense species selection, due to environmental conditions. The most frequently detected genes associated with resistance to antibiotics were tetM, tetQ, tetM, ermB, and mefA. The genes vanA, vanD, vanE, blaZ, mecA, lnuB, and ermC were not detected in the samples. The gene ermB was frequently detected in S, BS and CR samples. In patients from G1, tetM and tetQ were detected simultaneously in all the three environments (tetM = 4/6; tetQ = 3/6). There was no clustering behavior for samples belonging to different environments in the same patients and between the same environment samples from different groups. An overall analysis from the data allows for suggesting that the use of lactamic agents may alter compositional parameters from prokaryotic communities in the oral cavity to different extents. Specific environmental characteristics from each site may modulate the effect that seemed to be more intense for S than for BS and CR.

Apart from the nutrition factor, a threshold cell density of 10 8 cells per ml was established as an independent mediator which could elicit phenotypic tolerance under nutrient-rich conditions, producing phenotypes which were markedly different from those observable under starvation in terms of drug specificity. Such cell density effects could be attributed to (i) impeded diffusion of drug and nutrient molecules, which simultaneously suppressed the deleterious effects of antibiotics and elicited cellular protection responses, and (ii) a hitherto undefined quorum sensing-like induction signal which was detectable in spent media of nutrient-supplemented but not starving populations. This finding indicates that bacteria can initiate active defense through cell density sensing even in the absence of starvation stress. / Bacteria respond swiftly to environmental perturbations, often becoming insensitive to bactericidal antibiotics. The underlying basis of this tolerance phenomenon, which presumably involves physiological adaptation mechanisms that counteract antibiotic-induced lethality in bacteria, remains poorly-defined. In this study, the fundamental issues of antibiotic tolerance development were addressed, with a focus on elucidating the environmental cues and genetic determinants that regulate this phenotypic switching process. / By examining the relationship between exogenous nutrition status and antibiotic susceptibility in bacteria, amino acids deprivation was identified as a prerequisite condition for tolerance development, during which a repertoire of drug-sepcific phenotypes evolved according to the relative abundances of other key essential nutrients. Sustainability of tolerance was highly dependent on a lack of carbon source and the duration of nutrition stress. Importantly, organisms which experienced prolonged starvation (over 24 h) were found to harbor subpopulations which remained drug-tolerant in nutrient-rich medium, suggesting that antibiotic persisters originated from starvation-induced precursor organisms. / Comparative transcriptomic analysis showed that transient tolerance elicited by amino acids starvation was characterized by global metabolic down-regulation, whereas emergence of sustainable phenotypes was tightly coupled to a metabolically active state. Gene knockout analysis on established tolerance determinants, such as hipA, phoU and glpD, revealed that their roles in tolerance development were condition and drug specific, suggesting that the cellular network governing starvation-mediated tolerance was highly complex. Studies on selected determinants further revealed the functional roles of multiple stress signaling and protection systems, including the stringent and SOS responses, heat shock proteins, oxidative defense enzymes, and several novel determinants. Among them, the SOS response was specifically required for development of tolerance to fluoroquinolones, whereas products of two novel genes, yhfZ and yqgB, were predominantly involved in protection against both fluoroquinolones and aminoglycosides. Taken together, results of gene expression and deletion studies depict the involvement of multiple protection systems in sustaining antibiotic stress for a prolonged period. This idea was supported by results of functional studies, which suggested that growth inhibition by bacteriostatic agents, impedance of antibiotic entry and neutralization of hydroxyl radicals were in each case not sufficient to produce significant phenotypic tolerance. / In conclusion, starvation and high cell density-mediated responses were identified as complementary tolerance induction factors in bacteria. Further elucidation of the core components of bacterial "multidrug tolerance regulon" should enable development of more effective strategies for combating resilient microbial infections. / Fung, Ka Chun. / Advisers: Raphael Chan; Edward Chan. / Source: Dissertation Abstracts International, Volume: 73-02, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 136-152). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.

Orientador: Elisa Maria Aparecida Giro / Banca: Josemeri Hebling / Banca: Regina Maria Puppin Rontani / Resumo: A incorporação de agentes antibacterianos aos sistemas adesivos dentinários autocondicionantes tem sido proposta com o intuito de eliminar bactérias residuais presentes na dentina, prevenindo, assim, a recorrência de cárie. O presente trabalho teve como objetivo avaliar a atividade antibacteriana dos sistemas adesivos dentinários autocondicionantes: Clearfil Protect Bond (CPB), Clearfil SE Bond (CSEB), Xeno III (XIII) e Clearfil Tri-S Bond (C3SB), com e sem fotoativação, sobre bactérias cariogênicas, bem como a influência da dentina humana na atividade antibacteriana destes sistemas adesivos, utilizando o método de difusão em ágar. A solução de digluconato de clorexidina a 0,2% foi utilizada como controle positivo. O componente adesivo do CPB e do CSEB, o líquido A do XIII e o C3SB não apresentaram atividade antibacteriana quando aplicados sobre discos de papel. O conjunto primer e adesivo do CPB não fotoativado promoveu a maior inibição contra S. mutans (p<0,05), enquanto que com a fotoativação, não houve diferença entre esses componentes juntos e o primer isoladamente. Para o L. acidophillus, o primer do CPB apresentou a maior atividade antibacteriana nas duas condições de fotoativação (p<0,05). Quando os materiais foram aplicados sobre discos de dentina, somente a CHX promoveu efeito inibitório, o qual foi de menor intensidade do que quando aplicada sobre discos de papel (p<0,05). A CHX apresentou maior atividade antibacteriana sobre S. mutans quando comparado com L. acidophillus (p<0,05). Pode-se observar que a fotoativação reduziu significantemente a 18 atividade antibacteriana dos sistemas adesivos autocondicionantes, que a presença do MDPB no sistema adesivo dentinário é importante para a atividade antibacteriana sobre bactérias cariogênicas, e que a dentina atua como barreira de proteção eliminando ou reduzindo a ação antibacteriana de materiais odontológicos. / Abstract: The incorporation of antibacterial agents in self-etching dentin bonding systems has been introduced in attempts to eliminate dentin residual bacteria, preventing secondary caries. Therefore, the aim of this study was to evaluate the antibacterial activity of cured and uncured self-etching dentin bonding systems Clearfil Protect Bond (CPB), Clearfil SE Bond (CSEB), Xeno III (XIII) and Clearfil Tri-S Bond (C3SB), against S. mutans and L. acidophillus, by the agar disc-diffusion test, as well as to evaluate the influence of human dentin on their antibacterial activity. A 0.2% aqueous solution of chlorhexidine (CHX) was used as a positive control. CPB and CSEB bond component, liquid A of Xeno III and C3SB did not show any antibacterial activity when applied onto paper discs. The primer and bond set of uncured CPB presented the strongest inhibitory activity against S. mutans (p<0.05), however after light-activation, no difference was observed between these components together and when primer was applied individually. Independently of light-activation conditions, CPB primer showed the strongest antibacterial activity against L. acidophillus (p>0.05). When the materials were applied onto dentin discs, only CHX presented inhibitory activity, which was less intense than when it was applied onto paper discs (p<0.05). CHX showed stronger antibacterial activity against S. mutans than against L. acidophillus (p<0.05). In conclusion, light-activation significantly reduced the antibacterial activity, the presence of MDPB in adhesive systems is important to the inhibitory effect against cariogênico 20 bacteria, and the dentin acted as a protection barrier reducing or inhibiting the antibacterial activity of dental materials. / Mestre