Helicobacter pylori (hereinafter referred to as H. pylori) is a gram-negative bacteria which colonises the human stomach mucosa. Its role in the aethiopathogenesis of chronic gastritis, ulcer disorders of the gastroduodenum and MALT-lymphoma has been clearly demonstrated, and in connection with the occurrence of stomach cancer it has been indicated by the World Health Organisation (WHO) as a class I carcinogen. H. pylori infection can be detected from samples of stomach mucosa taken in an endoscopic examination (rapid urease test, microscopic examination, culture), or the non-invasive method can be used (13 C-Urea Breath Test or H. Pylori stool antigen test - HpSA). Effective therapy of H. pylori infection resides in the administration of a combination of antibiotics and a proton pump inhibitor. In recent years the resistance of bacterial strains to used antibiotics has been increasing on a worldwide scale, and we can also observe this trend in the case of H. pylori. If the level of resistance exceeds 20 % for clarithromycin and 40 % for metronidazole, these antibiotics are not recommended for the treatment of an infection caused by this bacteria. In a group of 61 patients at the Department of Internal Medicine at the University Hospital Motol who had undergone an endoscopic examination of the...

[pt] O surfactante pulmonar é um sistema lipo-proteico que atua na interface alveolar com vital importância para manter funcional a mecânica respiratória. Os comprometimentos na sua função estão associados a diversas infecções pulmonares. Os sistemas de administração de fármacos baseados em surfactantes pulmonares derivados de animais são complexos, dificultando a compreensão do papel individual das moléculas hóspedes nas suas interações com a membrana. Aqui apresentamos uma caracterização de um extrato surfactante de pulmão porcino de grau clínico misturado com os antibióticos Levofloxacina e Claritromicina, usando uma abordagem multi-técnica – em conjunto com a metodologia de monocamadas de Langmuir– consistindo de isotermas de pressão de superfície-area, microscopia de ângulo de Brewster (BAM), espectroscopia de reflexão-absorção do infravermelho com modulação da polarização (PM-IRRAS), reflectometria de nêutrons (NR), ensaios in vitro e simulações de dinâmica molecular. Avaliou-se o efeito de ambos os antibióticos na estrutura das monocamadas de surfactantes de origem porcino bem como em monocamadas de DPPC. Foi revelado que a estabilidade / integridade das monocamadas é preservada na presença de ambas as drogas. Os sistemas mistos de antibiótico / surfactante pulmonar aumentam a atividade antibacteriana contra bactérias Gram-positivas (Bacillus cereus) e Gram-negativas (Escherichia coli). Essas descobertas fornecem novas percepções sobre a otimização de sistemas eficientes de administração de medicamentos para o tratamento de condições patológicas no nível respiratório. / [en] The lipo-proteic surfactant system acting at the alveolar interface is of vital importance for keeping functional the respiratory mechanics. Its impairments are associated with several pulmonary infections. Drug delivery systems based on animal-derived lung surfactants are complex making it difficult to understand the individual role of guest molecules in membrane interactions. Here we present a characterization of a clinical-grade porcine lung surfactant extract mixed with the antibiotics Levofloxacin and Clarithromycin, using a multi-technique approach –in conjunction with the Langmuir-monolayer methodology– consisting of surface pressure-area isotherms, Brewster angle microscopy (BAM), polarization modulation-infrared reflection-adsorption spectroscopy (PM-IRRAS), neutron reflectometry (NR), in vitro assays, and molecular dynamics simulations. The effect of both antibiotics in the structure of porcine lung surfactant monolayers as well as in DPPC monolayers was examined. It was revealed that the stability/integrity of the monolayers is preserved in the presence of both drugs. The mixed antibiotic/lung surfactant systems enhance the antibacterial activity against Gram-positive (Bacillus cereus) and Gram-negative (Escherichia coli) bacteria. These findings provide new insights into the optimization of efficient drug delivery systems for the treatment of pathological conditions at the respiratory level.

Claritromicina e clofazimina são utilizadas no tratamento da hanseníase e em infecções causadas pelo complexo Mycobacterium avium, comuns em portadores do HIV. Devido à escassez de dados sobre a toxicidade de esquemas terapêuticos que associam estes fármacos, este estudo teve por objetivo avaliar os efeitos adversos desta terapia, em ratos machos Wistar, por meio da determinação de parâmetros hematológicos, hemostáticos e bioquímicos e correlação destes parâmetros com a dose e concentração plasmática dos medicamentos, em regime de doses únicas e múltiplas. Para tanto foram realizados: a) contagem global e específica de leucócitos (método manual) e ensaios de fagocitose e burst oxidativo de neutrófilos (citometria de fluxo); b) contagem de plaquetas (método manual), tempo de protrombina, tempo de tromboplastina parcial ativada, níveis plasmáticos dos fatores VII e X (método automatizado); c) níveis séricos de gama-glutamiltransferase (método cinéticocolorimétrico) e bilirrubinas total e direta (método colorimétrico); d) concentrações plasmáticas dos fármacos (Cromatografia Líquida de Alta Eficiência). Não houve diferenças entre as concentrações plasmáticas dos fármacos administrados em monoterapia ou politerapia. Entretanto, tanto clofazimina como claritromicina tiveram redução das concentrações plasmáticas em regime de doses múltiplas, quando comparadas à dose única. Houve aumento do número de leucócitos (dose múltipla) e de células polimorfonucleares (doses única e múltipla) nos grupos tratados com claritromicina em monoterapia ou associada à clofazimina, e redução das células mononucleares, em doses única e múltipla, nos mesmos grupos. Os fármacos parecem inverter a proporção entre células mono e polimorfonucleares. Observou-se aumento do burst oxidativo nos animais tratados com os fármacos tanto em monoterapia como em regime de politerapia. Entretanto, não houve diferença entre os tratamentos com os fármacos em relação ao controle DMSO, em dose única. Em doses múltiplas, os tratamentos com clofazimina e claritromicina em monoterapia ou politerapia estimularam o aumento do burst oxidativo (p < 0,0001) em relação ao controle DMSO. Não foram verificadas diferenças na fagocitose entre os grupos tratados e controle, tanto em dose única como em doses múltiplas. Tempo de protrombina e tempo de tromboplastina parcial ativada não foram alterados com o uso dos fármacos. Os fatores VII e X da coagulação tiveram aumento de suas atividades quando os ratos foram tratados em regime de dose múltipla com claritromicina, em regime de mono e politerapia. Houve perda de cerca de 8 % do peso de ratos tratados com clofazimina e 18 % daqueles tratados com claritromicina ou com a associação dos dois fármacos, no esquema de doses múltiplas, entretanto não houve diferença entre os grupos quando foram avaliados os níveis de gama-glutamiltransferase e bilirrubinas total e direta. Concluindo, clofazimina e claritromicina provocam alterações hematológicas, hemostáticas e bioquímicas e os resultados de concentração plasmática são valiosos para avaliação de efeitos adversos em estudos comparativos de monoterapia e politerapia entre os medicamentos. / Clarithromycin and clofazimine have been used to treat leprosy and infections caused by Mycobacterium avium complex in HIV patients. Because there are few data about the toxicity of treatment regimens involving these drugs, this study aimed to evaluate the adverse effects of this therapy in male Wistar rats through the determination of hematological, haemostatic and biochemical parameters and correlate them with the dose and plasma concentrations of drugs, under a single and multiple dose regimen. Evaluation was performed as follows: a) Global and specific count of leukocytes (manual method), phagocytosis and oxidative burst of neutrophils assays (flow cytometry), b) platelet count (manual method), prothrombin time, activated partial thromboplastin time, plasma levels of factors VII and X (automated method), c) Gamma-glutamyltransferase (kinetic-colorimetric method) and total and direct bilirubin serum levels (colorimetric method), d) plasma concentrations of drugs (High-Performance Liquid Chromatography). There were no differences between plasma concentrations of the drugs administered in monotherapy or polytherapy. However, the concentrations of both clofazimine and clarithromycin have decreased in plasma in multiple dose regimen compared to single dose. There was an increase in the number of leukocytes (multiple dose) and polymorphonuclear cells (single and multiple doses) in the groups treated with clarithromycin in monotherapy or in association with clofazimine, and a decrease in the number of mononuclear cells in single and multiple doses, in the same groups. Both drugs seemed to reverse the proportion between mononuclear and polymorphonuclear cells. The oxidative burst was observed in animals treated with drugs in polytherapy or in monotherapy, however there was no difference between the treatment with drugs and the control with DMSO in single dose. In multiple doses, treatment with clofazimine and clarithromycin in monotherapy or polytherapy stimulated the increase of oxidative burst (p <0.0001) compared to control. There were no differences in phagocytosis between the treated and control groups in single and multiple doses. Prothrombin time and activated partial thromboplastin time have not changed with the use drugs. In contrast, the activities of factors VII and X of coagulation have increased when rats were treated with multiple doses regimes with clarithromycin alone or in association with clofazimine. There was weight loss of 8% in rats treated with clofazimine and 18% in those treated with clarithromycin or with association of the drugs in the multiple doses regimen. However, there was no difference between the groups when gammaglutamyltransferase and total and direct bilirubin levels were analyzed. Therefore, clofazimine and clarithromycin induce hematological, hemostatic and biochemical changes and the results of plasma concentration is valuable for assessing adverse effects in comparative studies of monotherapy and polytherapy of these drugs.

Abstract: The role of bacterial biofilms in patients with persistent CRS is of growing concern. The limited efficacy of some medical and surgical treatments for CRS illustrates the need for further progress in this area. The current treatments of chronic rhinosinusitis are concentrated on medical +/- surgical therapy. In this thesis, we consider two methods performed in chronic rhinosinusitis, endoscopic sinus surgery and long term low-dose macrolide therapy, and consider how they can affect bacterial biofilms. The effect of endoscopic sinus surgery on bacterial biofilms and the clinical impact of this condition on CRS patients may be far more profound than we can currently understand. To understand the impact of ESS on bacterial biofilms, we have performed the first prospective study to evaluate the effect of ESS on bacterial biofilms in patients with CRS and patients’ clinical outcomes after 3 months follow-up. We have shown that ESS results in a statistically significant improvement in QoL, subjective and objective outcome measures. In terms of bacterial biofilms, the mean OD630nm of isolates was significantly reduced after 3 months follow-up (p=0.043). No correlations between the reduction of bacterial biofilms with any of the objective, subjective and QoL outcomes were seen in our study. Macrolides have demonstrated their anti-inflamatory effects in the treatment of diffuse panbronchiolitis, asthma, cystis fibrosis and chronic rhinosinusitis. In recent years, there are a number of in vitro studies supporting the anti-biofilm effects of macrolide antibiotics, especially at sub-MICs level. These have shown that macrolides alter the outer membrane, lipopolysaccharide of biomass and inhibit the expression of other bacterial virulence factors which may disrupt the adherence of bacteria to form biofilms. Long term low dose macrolide therapy, therefore, may transform bacterial biofilms from the protected organized form into the plantonic form. In this thesis, we also report the first in vivo efficacy of long term low dose macrolides on bacterial biofilms in patients with CRS. Patients receiving oral macrolide showed significant improvements in subjective, objective and QoL scores following a 12 week course. Nasal swabs were taken from CRS patients at the first visit and 3 months after macrolide therapy. Using the microtiter biofilm assay, these swabs showed a reduction in the mean OD630nm of isolates in 8/12 patients. While it is well-known that bacterial biofilms are established in CRS patients, the relationship between the improvement of clinical symptoms and the severity of bacterial biofilm is less clear.

Claritromicina era considerada um antibiótico de escolha para infecções causadas pelo complexo Mycobacterium abscessus, entretando, recentemente falhas no tratamento com este antibiótico têm sido reportadas. A resistência adquirida a claritromicina está relacionada à mutações pontuais que acarretam substituição da adenina na posição 2058 ou na posição 2059 na região do gene rrl que codifica o domínio peptidil transferase do rRNA 23S. Um mecanismo secundário de resistência à claritromicina tem sido descrito como resistência induzida, que é conferida pelo polimorfismo T/C no nucleotídeo 28 do gene erm(41). A resistência adquirida pode ser detectada em até 3 dias de incubação do M. abscessus com a claritromicina enquanto que a resistência induzida requer mais do que 5 dias de incubação. Por outro lado, o uso de marcadores moleculares para detecção de resistência adquirida e induzida no complexo M. abscessus têm sido propostos. O objetivo desse estudo foi avaliar o perfil de suscetibilidade e os marcadores moleculares de resistência à claritromicina no complexo M. abscessus. Um total de 42 isolados de um estudo prévio de vigilância, entre os anos 2007 e 2013 foram utilizados. O perfil de suscetibilidade para a claritromicina foi determinado por microdiluição em caldo com leituras em 3, 5, 7 e 14 dias. Mutações nos genes rrl e erm(41) foram avaliados por PCR com primers específicos e posterior sequenciamento. Resistência à claritromicina, em até 3 dias de incubação, foi observada em 31 dos 42 (73,8%) isolados. Resistência induzida à claritromicina foi observada em 6 de 11 (54,5%) isolados que apresentaram resistência após 5 ou 7 dias de incubação. Todos os isolados com resistência induzida foram M. abscessus subsp. massiliense. Além disso, todos os 28 isolados de M. abscessus subsp. massiliense apresentaram deleção em erm(41). Apenas cinco isolados foram sensíveis à claritromicina após 14 dias de incubação. Nenhum dos 42 isolados apresentaram mutação pontual na região de peptidil transferase do rRNA 23S e todos os isolados apresentaram o polimorfismo T/C no nucleotídeo 28 do gene erm(41). Os dados deste estudo indicam a falta de correlação dos marcadores moleculares com a expressão de resistência à claritromicina. / Infections due to Mycobacterium abscessus complex used to respond to clarithromycin treatment but more recently treatment failure with this antibiotic has been reported. Acquired resistance to clarithromycin is related to substitutions at the adenine either at position 2058 or at position 2059 in a region of the rrl gene encoding to the peptidyltransferase domain of the 23S rRNA. A secondary mechanism related to clarithromycin resistance has been described as an inducible resistance, conferred by T/C polymorphism at the 28th nucleotide in erm(41) gene. Acquired resistance can be detected up to 3 days of incubation of the M. abscessus with the clarithromycin while inducible resistance requires more than 5 days of incubation. Molecular markers to detect acquired and inducible resistance in M. abscessus complex isolates were proposed. This study evaluated the profile of susceptibility and the molecular markers of clarithromycin resistance in M. abscessus complex. A total of 42 isolates from a previous surveillance study (2007 to 2013) were used in this study. The susceptibility profile for clarithromycin was determined by broth microdilution with reads at 3, 5, 7 and 14 days. Mutations in rrl and erm(41) genes were evaluated by PCR with specific primers followed by sequencing. Clarithromycin resistance, up to 3 days of incubation, was observed in 31 of 42 (73.8%) isolates. Inducible clarithromycin resistance was observed in 6 of 11 (54.5%) isolates which presented resistance only after 5 or 7 days of incubation. All isolates with inducible resistance were identified as M. abscessus subsp. massiliense. Moreover, all 28 M. abscessus subsp. massiliense had a deletion in erm(41). Only five isolates proved to be susceptible to clarithromycin after 14 days of incubation. None of the 42 isolates presented a point mutation in the peptidyltransferase region of the 23S rRNA (rrl) and all isolates presented the T/C polymorphism at the 28th nucleotide of the erm(41) gene. The data of this study indicates a lack of correlation of molecular markers of clarithromycin resistance for both acquired and inducible resistance to clarithromycin.

Claritromicina era considerada um antibiótico de escolha para infecções causadas pelo complexo Mycobacterium abscessus, entretando, recentemente falhas no tratamento com este antibiótico têm sido reportadas. A resistência adquirida a claritromicina está relacionada à mutações pontuais que acarretam substituição da adenina na posição 2058 ou na posição 2059 na região do gene rrl que codifica o domínio peptidil transferase do rRNA 23S. Um mecanismo secundário de resistência à claritromicina tem sido descrito como resistência induzida, que é conferida pelo polimorfismo T/C no nucleotídeo 28 do gene erm(41). A resistência adquirida pode ser detectada em até 3 dias de incubação do M. abscessus com a claritromicina enquanto que a resistência induzida requer mais do que 5 dias de incubação. Por outro lado, o uso de marcadores moleculares para detecção de resistência adquirida e induzida no complexo M. abscessus têm sido propostos. O objetivo desse estudo foi avaliar o perfil de suscetibilidade e os marcadores moleculares de resistência à claritromicina no complexo M. abscessus. Um total de 42 isolados de um estudo prévio de vigilância, entre os anos 2007 e 2013 foram utilizados. O perfil de suscetibilidade para a claritromicina foi determinado por microdiluição em caldo com leituras em 3, 5, 7 e 14 dias. Mutações nos genes rrl e erm(41) foram avaliados por PCR com primers específicos e posterior sequenciamento. Resistência à claritromicina, em até 3 dias de incubação, foi observada em 31 dos 42 (73,8%) isolados. Resistência induzida à claritromicina foi observada em 6 de 11 (54,5%) isolados que apresentaram resistência após 5 ou 7 dias de incubação. Todos os isolados com resistência induzida foram M. abscessus subsp. massiliense. Além disso, todos os 28 isolados de M. abscessus subsp. massiliense apresentaram deleção em erm(41). Apenas cinco isolados foram sensíveis à claritromicina após 14 dias de incubação. Nenhum dos 42 isolados apresentaram mutação pontual na região de peptidil transferase do rRNA 23S e todos os isolados apresentaram o polimorfismo T/C no nucleotídeo 28 do gene erm(41). Os dados deste estudo indicam a falta de correlação dos marcadores moleculares com a expressão de resistência à claritromicina. / Infections due to Mycobacterium abscessus complex used to respond to clarithromycin treatment but more recently treatment failure with this antibiotic has been reported. Acquired resistance to clarithromycin is related to substitutions at the adenine either at position 2058 or at position 2059 in a region of the rrl gene encoding to the peptidyltransferase domain of the 23S rRNA. A secondary mechanism related to clarithromycin resistance has been described as an inducible resistance, conferred by T/C polymorphism at the 28th nucleotide in erm(41) gene. Acquired resistance can be detected up to 3 days of incubation of the M. abscessus with the clarithromycin while inducible resistance requires more than 5 days of incubation. Molecular markers to detect acquired and inducible resistance in M. abscessus complex isolates were proposed. This study evaluated the profile of susceptibility and the molecular markers of clarithromycin resistance in M. abscessus complex. A total of 42 isolates from a previous surveillance study (2007 to 2013) were used in this study. The susceptibility profile for clarithromycin was determined by broth microdilution with reads at 3, 5, 7 and 14 days. Mutations in rrl and erm(41) genes were evaluated by PCR with specific primers followed by sequencing. Clarithromycin resistance, up to 3 days of incubation, was observed in 31 of 42 (73.8%) isolates. Inducible clarithromycin resistance was observed in 6 of 11 (54.5%) isolates which presented resistance only after 5 or 7 days of incubation. All isolates with inducible resistance were identified as M. abscessus subsp. massiliense. Moreover, all 28 M. abscessus subsp. massiliense had a deletion in erm(41). Only five isolates proved to be susceptible to clarithromycin after 14 days of incubation. None of the 42 isolates presented a point mutation in the peptidyltransferase region of the 23S rRNA (rrl) and all isolates presented the T/C polymorphism at the 28th nucleotide of the erm(41) gene. The data of this study indicates a lack of correlation of molecular markers of clarithromycin resistance for both acquired and inducible resistance to clarithromycin.

Claritromicina e clofazimina são utilizadas no tratamento da hanseníase e em infecções causadas pelo complexo Mycobacterium avium, comuns em portadores do HIV. Devido à escassez de dados sobre a toxicidade de esquemas terapêuticos que associam estes fármacos, este estudo teve por objetivo avaliar os efeitos adversos desta terapia, em ratos machos Wistar, por meio da determinação de parâmetros hematológicos, hemostáticos e bioquímicos e correlação destes parâmetros com a dose e concentração plasmática dos medicamentos, em regime de doses únicas e múltiplas. Para tanto foram realizados: a) contagem global e específica de leucócitos (método manual) e ensaios de fagocitose e burst oxidativo de neutrófilos (citometria de fluxo); b) contagem de plaquetas (método manual), tempo de protrombina, tempo de tromboplastina parcial ativada, níveis plasmáticos dos fatores VII e X (método automatizado); c) níveis séricos de gama-glutamiltransferase (método cinéticocolorimétrico) e bilirrubinas total e direta (método colorimétrico); d) concentrações plasmáticas dos fármacos (Cromatografia Líquida de Alta Eficiência). Não houve diferenças entre as concentrações plasmáticas dos fármacos administrados em monoterapia ou politerapia. Entretanto, tanto clofazimina como claritromicina tiveram redução das concentrações plasmáticas em regime de doses múltiplas, quando comparadas à dose única. Houve aumento do número de leucócitos (dose múltipla) e de células polimorfonucleares (doses única e múltipla) nos grupos tratados com claritromicina em monoterapia ou associada à clofazimina, e redução das células mononucleares, em doses única e múltipla, nos mesmos grupos. Os fármacos parecem inverter a proporção entre células mono e polimorfonucleares. Observou-se aumento do burst oxidativo nos animais tratados com os fármacos tanto em monoterapia como em regime de politerapia. Entretanto, não houve diferença entre os tratamentos com os fármacos em relação ao controle DMSO, em dose única. Em doses múltiplas, os tratamentos com clofazimina e claritromicina em monoterapia ou politerapia estimularam o aumento do burst oxidativo (p < 0,0001) em relação ao controle DMSO. Não foram verificadas diferenças na fagocitose entre os grupos tratados e controle, tanto em dose única como em doses múltiplas. Tempo de protrombina e tempo de tromboplastina parcial ativada não foram alterados com o uso dos fármacos. Os fatores VII e X da coagulação tiveram aumento de suas atividades quando os ratos foram tratados em regime de dose múltipla com claritromicina, em regime de mono e politerapia. Houve perda de cerca de 8 % do peso de ratos tratados com clofazimina e 18 % daqueles tratados com claritromicina ou com a associação dos dois fármacos, no esquema de doses múltiplas, entretanto não houve diferença entre os grupos quando foram avaliados os níveis de gama-glutamiltransferase e bilirrubinas total e direta. Concluindo, clofazimina e claritromicina provocam alterações hematológicas, hemostáticas e bioquímicas e os resultados de concentração plasmática são valiosos para avaliação de efeitos adversos em estudos comparativos de monoterapia e politerapia entre os medicamentos. / Clarithromycin and clofazimine have been used to treat leprosy and infections caused by Mycobacterium avium complex in HIV patients. Because there are few data about the toxicity of treatment regimens involving these drugs, this study aimed to evaluate the adverse effects of this therapy in male Wistar rats through the determination of hematological, haemostatic and biochemical parameters and correlate them with the dose and plasma concentrations of drugs, under a single and multiple dose regimen. Evaluation was performed as follows: a) Global and specific count of leukocytes (manual method), phagocytosis and oxidative burst of neutrophils assays (flow cytometry), b) platelet count (manual method), prothrombin time, activated partial thromboplastin time, plasma levels of factors VII and X (automated method), c) Gamma-glutamyltransferase (kinetic-colorimetric method) and total and direct bilirubin serum levels (colorimetric method), d) plasma concentrations of drugs (High-Performance Liquid Chromatography). There were no differences between plasma concentrations of the drugs administered in monotherapy or polytherapy. However, the concentrations of both clofazimine and clarithromycin have decreased in plasma in multiple dose regimen compared to single dose. There was an increase in the number of leukocytes (multiple dose) and polymorphonuclear cells (single and multiple doses) in the groups treated with clarithromycin in monotherapy or in association with clofazimine, and a decrease in the number of mononuclear cells in single and multiple doses, in the same groups. Both drugs seemed to reverse the proportion between mononuclear and polymorphonuclear cells. The oxidative burst was observed in animals treated with drugs in polytherapy or in monotherapy, however there was no difference between the treatment with drugs and the control with DMSO in single dose. In multiple doses, treatment with clofazimine and clarithromycin in monotherapy or polytherapy stimulated the increase of oxidative burst (p <0.0001) compared to control. There were no differences in phagocytosis between the treated and control groups in single and multiple doses. Prothrombin time and activated partial thromboplastin time have not changed with the use drugs. In contrast, the activities of factors VII and X of coagulation have increased when rats were treated with multiple doses regimes with clarithromycin alone or in association with clofazimine. There was weight loss of 8% in rats treated with clofazimine and 18% in those treated with clarithromycin or with association of the drugs in the multiple doses regimen. However, there was no difference between the groups when gammaglutamyltransferase and total and direct bilirubin levels were analyzed. Therefore, clofazimine and clarithromycin induce hematological, hemostatic and biochemical changes and the results of plasma concentration is valuable for assessing adverse effects in comparative studies of monotherapy and polytherapy of these drugs.

C-reactive protein (CRP) is a component of innate immunity. The concentration of CRP in serum increases in microbial infections including Streptococcus pneumoniae infection. Employing a mouse model of pneumococcal infection, it has been shown that passively administered human wild-type CRP protects mice against infection, provided that CRP is injected into mice within two hours of administering pneumococci. Engineered CRP (E-CRP) molecules have been reported recently; unlike wild-type CRP, passively administered E-CRP protected mice against infection even when E-CRP was injected into mice after twelve hours of administering pneumococci. The current study was aimed at comparing the protective capacity of E-CRP with that of an antibiotic clarithromycin. We established a mouse model of pneumococcal infection in which both E-CRP and clarithromycin, when used alone, provided minimal but equal protection against infection. In this model, the combination of E-CRP and clarithromycin drastically reduced bacteremia and increased survival of mice when compared to the protective effects of either E-CRP or clarithromycin alone. E-CRP was more effective in reducing bacteremia in mice treated with clarithromycin than in untreated mice. Also, there was 90% reduction in antibiotic dosing by including E-CRP in the antibiotic-treatment for maximal protection of infected mice. These findings provide an example of cooperation between the innate immune system and molecules that prevent multiplication of bacteria, and that should be exploited to develop novel combination therapies for infections against multidrug-resistant pneumococci. The reduction in antibiotic dosing by including E-CRP in the combination therapy might also resolve the problem of developing antibiotic resistance.

Pullulan is a non-ionic water-soluble polysaccharide which is produced from starch by the yeast-like fungus Aureobasidium pullulans. Pullulan is known for its non-toxicity and biocompatibility. Most pullulan modifications are intended to reduce its water solubility or to introduce charged or reactive groups for functionality. Polysaccharides that have been hydrophobically modified and contain carboxyl groups are commonly used in drug delivery systems because of their ability to provide pH-controlled drug release. We demonstrated in this dissertation the regioselective synthesis of a range of 6-carboxypullulan ethers that are promising anionic derivatives for drug delivery applications. These compounds have also shown impressive surfactant properties. Another class of pullulan derivatives was synthesized by regioselective introduction of amine and amide groups to the pullulan backbone. These chemical groups are known to play a fundamental role in the biological activity of important polysaccharides, such as chitin and chitosan, therefore, the pullulan derivatives synthesized herein, which are structural isomers of those polymers, possess great potential for biomedical applications. Clarithromycin (CLA) is an aminomacrolide antibiotic whose physical properties are fascinating and challenging. It has very poor solubility at neutral intestinal pH, but much higher solubility under acidic conditions. Therefore, CLA dissolves better in the stomach than in the small intestine; but CLA is also quite labile towards acid-catalyzed degradation. We report herein a study on amorphous solid dispersion (ASD) of CLA with promising carboxyl-containing cellulose derivatives, both as macro and nanoparticles. This approach was intended to improve CLA solubility in neutral media, to protect it from acid degradation, and thereby increase its uptake from the small intestine and ultimately its bioavailability. We have also prepared ASDs of selected anti-HIV drugs, ritonavir (RTV), efavirenz (EFV) and etravirine (ETR) with the cellulosic derivative carboxymethyl cellulose acetate butyrate (CMCAB). This polymer was efficient in stabilizing RTV and EFV in their amorphous form in the solid phase and all ASDs provided significant enhancement of drug solution concentration. / Ph. D.

Sucrose acetate isobutyrate (SAIB), a randomly substituted sucrose approximating sucrose diacetate hexaisobutyrate, is produced by Eastman Chemical Company for a variety of applications. SAIB is widely used in the food industry as a weighting agent to disperse flavoring oils in primarily citrus-based soft drink beverages. Additionally, SAIB is currently being marketed by another company as a parenteral drug delivery system. The studies reported here focused on investigating SAIB as an excipient, or delivery vehicle, for use in oral delivery of several drugs, including ibuprofen, saquinavir, and clarithromycin. Dissolution experiments were conducted using both ibuprofen and caffeine, and results suggest that SAIB can be used in dosage forms to control release rate. Pharmacokinetic studies in which laboratory rats were dosed with formulations containing drugs such as ibuprofen, saquinavir, and clarithromycin suggest that SAIB may act to reduce animal-to-animal variability in drug concentration profiles in some cases, and that it may also enhance gastroretention of the dosage forms. Finally, dosage form imaging studies suggest but do not reliably confirm that SAIB may aid in promoting gastric retention, which would make its use in dosage form formulation beneficial for administration of drugs whose action is intended to occur in the stomach.