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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

SÃntese e caracterizaÃÃo de emulsÃes de Pickering a base de goma do cajueiro enxertado com lactÃdeo / Synthesis and characterization of cashew gum graft lactide Pickering emulsion

Ana Rosa Richter 05 March 2015 (has links)
O objetivo deste trabalho foi sintetizar emulsÃes de Pickering a partir da goma do cajueiro (GC) enxertada com poli lactÃdeo (PLA) para incorporaÃÃo de anfotericina B (AB), utilizando como fase oleosa o miglyol. A GC foi isolada do exsudato por precipitaÃÃo em etanol e modificada por reaÃÃo de enxertia na cadeia lateral com o PLA. O copolÃmero foi purificado por lavagem com hexano e denominado GCPLAP. Foram realizadas trÃs condiÃÃes reacionais, 1:1; 1:5 e 1:10, variando a razÃo molar GC/PLA. A confirmaÃÃo da reaÃÃo foi possÃvel atravÃs dos espectros de FTIR, pelo aparecimento de uma banda em 1700 cm-1, caracterÃstica de estiramento C=O da carbonila. O grau de substituiÃÃo foi determinado por RMN H1, que aumentou com o aumento da proporÃÃo molar de PLA. O TGA mostrou que a enxertia do PLA confere uma maior estabilidade tÃrmica à GCPLAP quando comparado a GC. Na anÃlise tÃrmica de DSC observa-se um estreitamento do pico endotÃrmico a medida em que se aumenta a proporÃÃo de PLA. NÃo foi possÃvel detectar os cristais de PLA enxertados na GC por difraÃÃo de raios-X. Pelos dois mÃtodos de citotoxicidade in vitro, MTT e LDH, foi comprovada a nÃo citotoxicidade do copolÃmero. As emulsÃes foram sintetizadas vertendo a fase orgÃnica sob a fase aquosa e houve a formaÃÃo instantÃnea das emulsÃes. O teste do fenol sulfÃrico demonstrou que para todas as condiÃÃes de emulsÃes o processo de isolamento por centrifugaÃÃo nÃo desestabiliza nem separa as nanopartÃculas das gotas de Ãleo. O tamanho das emulsÃes, determinados por espalhamento dinÃmico de luz, apresentaram distribuiÃÃo unimodal e diminuÃram apÃs o isolamento em centrÃfuga. As emulsÃes com copolÃmero GCPLAP 1:1 obtiveram os menores valores de tamanho e IPD, alÃm de melhor estabilidade com a variaÃÃo do tempo. A AB foi incorporada Ãs emulsÃes e atravÃs do espectro de UV-Vis foi possÃvel verificar que a eficiÃncia de encapsulamento em torno de 25% para todas as formulaÃÃes testadas. / The aim of this work was to synthesize Pickering emulsions from the cashew tree gum (GC) grafted with polylactide (PLA) using miglyol as oily phase as potential matrix for Amphotericin B (AB) incorporation. GC was isolated from exsudate by precipitation with ethanol and it was modified through the PLA graft reaction. The copolymer was purified and named GCPLAP. The graft reaction was performed in three GC/PLA molar ratio conditions (1:1, 1:5 and 1:10). The presence of PLA gratf to GC was confirmed by FTIR and NMR spectra. The degree of substitution was measured by RMN 1H, and it increases with increase of PLA amount in the CG/PLA molar ratio conditions. TGA analysis showed the graft of PLA provides a better thermal stability in comparison with GC. DSC thermal analysis showed a more well define peak as the PLA ratio increases. It was not possible to detect crystallization due the insertion of PLA into GC through X-ray microscopy. In vitro citotoxicity methods (MTT and HDL) confirmed the non-toxicity of the grafted polymer. Emulsions were prepared by adding the organic phase in the aqueous phase, resulting the immediate emulsion formation. The sulfuric phenol test showed the presence of CG in all emulsion prepared with differents GC/PLA molar ratio samples. The isolation by centrifugation does not destabilize or separate nanoparticles from oil droplets. The emulsion size, measured by dynamic light scattering, presented unimodal distribution and they decreased after the isolation by centrifugation. Emulsions with GCPLAP 1:1 presented the less values in size and IPD, in addiction to the best stability over time. The AB was incorporated in the emulsions and it was possible to verify the encapsulation efficiency by UV-VIS, was about 25% in all of the tested formulations.
52

Caracterização de mecanismos de resistência à terbinafina em diferentes espécies de Leishmania / Characterization of resistance mechanisms to terbinafine in different species of Leishmania

Fabrício César Dias 24 November 2008 (has links)
O fenômeno de amplificação gênica é um mecanismo de auto-preservação celular observado com freqüência no protozoário parasita Leishmania quando submetido a estímulos negativos como, por exemplo, a presença de drogas. A região H do genoma de Leishmania (Leishmania) major é um dos loci mais estudados que leva à amplificação em resposta a drogas não relacionadas, como a terbinafina. Foram isoladas linhagens de L. (L.) major e Leishmania (Viannia) braziliensis resistentes à terbinafina. Análises por corridas curtas de eletroforese em campo pulsado (PFGE) e Southern blotting revelaram que a resistência observada nestas linhagens não foi gerada pela amplificação do locus H. Sendo assim, a resistência ao inibidor da esqualeno epoxidase está sendo gerada por um outro mecanismo uma vez que outros loci podem estar envolvidos na resistência à terbinafina e através da análise diferencial do perfil de proteínas, os mutantes resistentes apresentaram diferenças na expressão de proteínas. O alvo inicial para a elucidação da resistência à terbinafina nas linhagens selecionadas foi a via de biossíntese de ergosterol. Foram escolhidos os genes da 3-cetoacil-CoA tiolase (ERG10), esqualeno sintase (ERG9 ou SQS1), esqualeno epoxidase (ERG1), oxidoesqualeno-lanosterol ciclase (ERG7) e lanosterol 14-demetilase (ERG11), de L. major e L. braziliensis, além do gene YIP1 de L. braziliensis. Para isso foram sintetizados oligonucleotídeos a partir das seqüências geradas pelo projeto genoma destas espécies depositadas em bancos de dados. Os genes ERG10, SQS1, ERG1, ERG7 e ERG11 de L. major e de L. braziliensis além do YIP1 de L. braziliensis amplificados por PCR foram clonados no vetor pGEM-T Easy, que possibilitou a construção de reagentes para ruptura de todos genes pela inserção da marca HYG e, com exceção do gene ERG7 de L. braziliensis, os genes foram subclonados no vetor pXG1. Fragmentos de restrição dos genes clonados no vetor pGEM-T Easy foram utilizados para analisar o nível de seus transcritos por northern blot. Também verificamos através de corridas curtas de PFGE e análises de Southern, que as linhagens em estudo não apresentam amplificação dos loci em estudo. A participação de genes da via de biossíntese de ergosterol de L. major e L. braziliensis e do gene YIP1 de L. braziliensis na resistência ou susceptibilidade à terbinafina e/ou anfotericina B foi verificada através de experimentos funcionais. Com esse objetivo, os genes YIP1, ERG10 e ERG1 de L. braziliensis foram transfectados na linhagem LB2904 de L. braziliensis, e os genes ERG10, SQS1, ERG1, ERG7 e ERG11 e a ruptura do gene ERG1 pelo cassete HYG de L. major foram transfectados na linhagem LT252 de L. major. Foram realizados experimentos para analisar a susceptibilidade à anfotericina B associada ou não à terbinafina, das linhagens selvagens de L. major e L. braziliensis, e a partir destes experimentos iniciais, foram selecionadas linhagens destas duas espécies resistentes à anfotericina B. Para analisar a possível função regulatória dos elementos RIME 5/2/6 de L. braziliensis, foi feita a amplificação por PCR da repetição invertida LbRIME 5/2/6b que permitiu a clonagem deste fragmento no vetor pGEM-T Easy e a sua ruptura pela marca SAT. A clonagem no vetor pGEM possibilitou a análise da interação de proteínas nucleares à repetição LbRIME 5/2/6b através do gel shift. / Gene amplification is a common phenomenon observed in Leishmania cell lines subjected to drug pressure. The H locus of Leishmania (Leishmania) major is normally found amplified in cell lines selected in unrelated drugs, as terbinafine. We selected cell lines of L. (L.) major and Leishmania (Viannia) braziliensis resistant to terbinafine. Short-run Pulsed Field Gel Electrophoresis (PFGE) and Southern blotting analysis showed that this resistance was not generated by H locus amplification. Resistance to squalene epoxidase inhibiter is being generated by other mechanism once others loci can be involved in the terbinafine resistance and through protein partner differential analysis, mutants resistant showed differences in protein expression. The initial target to terbinafine resistance elucidation in the cell lines selected was ergosterol biosynthesis pathway. We choose genes: 3-ketoacyl-CoA thiolase (ERG10), squalene synthase (ERG9 or SQS1), squalene epoxidase (ERG1), oxidosqualene-lanosterol cyclase (ERG7), and lanosterol 14-demethylase (ERG11), of L. major and L. braziliensis, besides YIP1 gene of L. braziliensis. For this, primers were synthesized using the sequences generated by genome project of these species inserted in gene bank. The genes ERG10, SQS1, ERG1, ERG7 and ERG11 of L. major and of L. braziliensis besides YIP1 of L. braziliensis were amplified by PCR and cloned into pGEM-T Easy vector that enabled all genes disruption by insertion of HYG cassette and, with exception of the ERG7 gene of L. braziliensis, genes were subcloned into shuttle-vector pXG1. Restrictions fragments of these genes were used in Northern analysis to verify the transcripts level. We verified through short-run PFGE and Southern analysis that the resistant cell lines do not show amplification of studied loci. The participation of ergosterol biosynthesis pathway genes of L. major and L. braziliensis and YIP1 gene of L. braziliensis in the resistance to terbinafine was verified in functional experiments. With this objective, the genes YIP1, ERG10 and ERG1 of L. braziliensis were transfected into LB2904 cell line of L. braziliensis, and the genes ERG10, SQS1, ERG1, ERG7 and ERG11 and the ERG1 gene disruption by HYG mark of L. major were transfected into LT252 cell line of L. major. Experiments that analyze the susceptibility to amphotericin B associated or not to terbinafine were performed using the wild type cell lines of L. major and L. braziliensis, and with this initials experiments, we selected cell lines of these two species resistant to amphotericin B. In order to analyze the possible regulatory function of the RIME 5/2/6 elements of L. braziliensis, the repeat LbRIME 5/2/6b was amplified by PCR and cloned into pGEM-T Easy vector and with this clone, the element was disrupted with a SAT cassette. The cloning into vector pGEM enabled to analyze the interaction of the nuclear protein with the repeat LbRIME 5/2/6b through gel shift assay.
53

Uso da anfotericina B lipossomal e de outras drogas no tratamento de pacientes com leishmaniose mucosa: análise da experiência em um serviço de referência para o diagnóstico e tratamento das leishmanioses, 2000-2015 / Use of liposomal amphotericin B and other drugs for the treatment of patients presenting with mucosal leishmaniasis: analysis of the experience in a referenced institute for the treatment of leishmaniasis, 2000-2015

Carolina Rocio Oliveira Santos 15 August 2018 (has links)
Introdução: As leishmanioses são antropozoonoses que constituem um grave problema de saúde pública por apresentarem um complexo espectro clínico de manifestações e relevante diversidade epidemiológica. Aproximadamente 5% dos pacientes com leishmaniose cutânea não tratada adequadamente irão desenvolver a leishmaniose mucosa (LM). As principais opções terapêuticas disponíveis para esta apresentação da doença são os antimoniais pentavalentes, a pentamidina e as anfotericinas B. As formulações lipídicas da anfotericina B tem sido desenvolvidas na tentativa de melhorar a eficácia e a tolerabilidade das anfotericinas, entretanto, ainda há escassez de estudos que avaliem eficácia, dose e segurança da anfotericina B lipossomal (AFBL) no tratamento da LM. Objetivo: Relatar a experiência do ambulatório e da enfermaria de um hospital escola com medicamentos usados no tratamento da leishmaniose mucosa, comparando a eficácia e a segurança da anfotericina B lipossomal com as outras drogas. Métodos: Foram avaliados os prontuários de todos os pacientes do Ambulatório de Leishmanioses do Departamento de Moléstias Infecciosas e Parasitárias do HC-FMUSP com diagnóstico confirmado de LM e tratados no período de janeiro de 2000 a julho de 2015. Dados clínicos e epidemiológicos foram descritos, e também avaliados os efeitos adversos e os desfechos com o uso das principais drogas para LM. Resultados: Foram avaliados 71 pacientes com leishmaniose mucosa e um total de 106 tratamentos. A maioria dos pacientes era do sexo masculino (60,6%) e da Região Nordeste do Brasil (50%). Observou-se associação de flebite (46,2%) e de tremor (30,8%) com o grupo que recebeu anfotericina B complexo lipídico e maior desenvolvimento de artralgia (16%) no grupo que recebeu o antimonial. Os pacientes tratados com anfotericina B desoxicolato apresentaram a maior taxa de insuficiência renal aguda (57,10%) em relação aos demais grupos de drogas. O grupo que usou antimonial pentavalente foi o único que desenvolveu alterações nas enzimas pancreáticas (28%) e alterações eletrocardiográficas (20%). Dos pacientes que usaram anfotericina B desoxicolato, 85,7% precisaram interromper definitivamente o tratamento, o que contribuiu para a pior taxa de cicatrização final (14,3%), enquanto a AFBL apresentou a melhor taxa (81,3%) quando comparada aos demais tratamentos, OR= 4,971 [1,829-13,508] (p= 0,001). O uso de itraconazol mostrou alta taxa de recidiva (63,6%). A dose média de AFBL usada no tratamento de LM foi 1907mg e 28,91mg/kg. Quando comparadas as drogas com a AFBL, a pentamidina foi a única que não apresentou diferença estatisticamente significante em relação aos desfechos de tratamento. Conclusão: A pentamidina e a AFBL mostraram-se, neste estudo, as melhores opções terapêuticas no tratamento da LM, sendo que a AFBL foi a droga com a maior taxa de cicatrização. Com base neste estudo e em outras experiências da literatura até o momento, o intervalo de dose compreendido entre 30 e 35 mg/kg é o que parece alcançar eficácia próxima a 100%. Sugerimos, portanto, uma dose cumulativa de 30 mg/kg para o tratamento da LM. Este estudo amplia a experiência com o uso do itraconazol e da pentamidina, e é o primeiro a descrever o uso da ABCL na LM. Apresenta, ainda, a maior casuística que conhecemos na literatura com o uso da AFBL, além de ser o primeiro estudo a compará-la com as demais drogas no tratamento da LMCRO / Introduction: Leishmaniases are anthropozoonoses that constitute a severe problem of public health as they present with a complex spectrum of manifestations and relevant epidemiologic diversity. Approximately 5% of patients with untreated cutaneous leishmaniosis will develop mucosal leishmaniasis (ML). The main treatment options for this presentation are: pentavalent antimonials, pentamidine, and amphotericins B. The lipid formulations of amphotericin B have been developed to improve efficacy and tolerability, however, there are few studies that evaluate efficacy, dosage, and safety of liposomal amphotericin B (LAB) for treatment of ML. Objective: To report outpatient and inpatient experience of a hospital school with medications used for treatment of mucosal leishmaniasis by comparing the efficacy and safety of liposomal amphotericin B with other drugs. Methodology: The medical records of all patients of the Leishmaniasis Outpatient Clinic of the Department of Infectious and Parasitic Diseases of the Hospital das Clínicas of University of São Paulo were assessed. The patients had diagnosis of ML and were treated between January 2000 and July 2015. Epidemiologic and clinical data were described, as well as adverse effects and outcomes of the main drugs for treatment of ML. Results: Seventy-one patients with ML and a total of 106 treatments were assessed. The majority of the patients were male (60.6%) and from the Northeast of Brazil (50%). There was an association of phlebitis (46.2%) and tremor (30.8%) to the group that received amphotericin B lipid complex (ABLC). There was a higher development of arthralgia (16%) in the group that received the antimonial. Patients treated with deoxycholate amphotericin B presented with the highest level of acute kidney injury (57.1%) when compared to other drugs. The group who received pentavalent antimonial was the only one to develop pancreatic enzymes abnormalities (28%) and electrocardiographic abnormalities (20%). Within the patients who used deoxycholate amphotericin B, 85.7% had to discontinue the treatment, contributing to the worst healing rate (14.3%). LAB presented with the best healing rate (81.3%) when compared to the other treatments, OR = 4.971 [1,829-13,508] (p=0,001). The use of itraconazole showed high recurrence rate (63.6%). The mean dosage of LAB for the treatment of ML was 1,907 mg and 28.91 mg/kg. When LAB was compared to other drugs, pentamidine was the only one with no statistical significance related to the outcomes of the treatment. Conclusion: In this study, pentamidine and LAB were the best therapeutic options for the treatment of ML; LAB was the drug with better healing rate. Based on this study and other references in the literature, the dosage interval between 30 and 35 mg/kg appears to reach efficacy close to 100%. Therefore, our recommendation is the use of a cumulative dosage of 30 mg/kg for the treatment of ML. This study enhances the experience of itraconazole and pentamidine, and it is the first one to describe the use of ABLC for the treatment of ML. In addition, it presents the largest casuistic known in the literature with the use of LAB, and it is a pioneer in comparing this drug with other drugs in the treatment of ML
54

NANOPARTÍCULAS MAGNÉTICAS FUNCIONALIZADAS COM BICAMADAS DE LAURATO/LAURATO E LAURATO/PLURONIC: ESTUDO DA ASSOCIAÇÃO COM ANFOTERICINA / MAGNETIC NANOPARTICLES FUNCTIONALIZED WITH AMPHOTERICIN B OF BILAYERS LAURATE/LAURATE AND LAURATE/PLURONIC: STUDY OF THE ASSOCIATION WITH AMPHOTERICIN B

SILVA, Joel Rocha da 27 May 2008 (has links)
Made available in DSpace on 2014-07-29T15:12:48Z (GMT). No. of bitstreams: 1 Dissertacao - Joel Rocha da Silva.pdf: 557734 bytes, checksum: 97955f40a90305a3592aea224371f9ea (MD5) Previous issue date: 2008-05-27 / Magnetite nanoparticles were prepared by the coprecipitation of ions Fe2+ and Fe3+ using ammonia solution as precipitating agent. Maghemite nanoparticles were prepared by forced oxidation of magnetite nanoparticles in acidic medium using nitrate ions as oxidizing agent. The magnetic nanoparticles were used to the preparation of aqueous magnetic fluids samples by the functionalization of the nanoparticles with bilayers of laurate/laurate and laurate/Pluronic. Aliquots of the magnetic fluids were dried and the resultant powders were characterized by chemical analysis (the contents of ions Fe2+ and Fe3+), X-ray powder diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR). The contents of ions Fe2+ and Fe3+ in all the samples showed that the nanoparticles are not pure magnetite or maghemite phases. X-ray powder diffraction (XRD) indicated the existence of inverse cubic spinel phase, but didn't permit the distinction between magnetite and maghemite phases. Based on the results of chemical and XRD analyses, the nanoparticles could be better characterized as reduced maghemite, which mean maghemite phase containing ions Fe2+. The average sizes of the oxide nanoparticles estimated by XRD were around of 10 nm. FTIR analyses showed that the nanoparticles were functionalized with bilayers of laurate/laurate and laurate/Pluronic. FTIR analyses also were indicative of the maghemite phase. The hydrodynamic size of the functionalized nanoparticles measured by PCS were in the range of 70-90 nm for the samples based on laurate and in the range of 100-200 nm for the samples containing Pluronic. The measurements of zeta potential showed that the magnetic fluids based on laurate bilayers presented better colloidal stability than that one based on bilayers of laurate/Pluronic. On the other hand, the studies of colloidal stability in cell culture medium by hydrodynamic size measurements showed the lost of colloidal stability of all the samples, in all the concentrations of medium investigated. The fluids with laurate/laurate bilayers showed higher ratio of aggregation in the culture medium than the fluids with laurate/Pluronic. The association of amphotericin B with nanoparticles was carried out only using the samples with laurate bilayers. The results showed that the ratio of association depends on the concentration of amphotericin added to the magnetic fluid. It was observed 100% of amphotericin association in the range of nanoparticles/amphotericin concentrations used, which in turn are adequated for posterior in vivo studies / Nanopartículas de magnetita foram preparadas pela coprecipitação dos íons Fe2+ e Fe3+ usando uma solução de amônia como o agente de precipitação. As nanopartículas de maguemita foram preparadas por oxidação forçada de nanopartículas de magnetita usando íons nitrato como o agente de oxidação, em meio ácido. As nanopartículas magnéticas foram usadas para a preparação de fluidos magnéticos aquosos pela funcionalização das nanopartículas com bicamadas de laurato/laurato e laurato/Pluronic. As alíquotas dos fluidos magnéticos foram secas e o pó resultante foi caracterizado por análise química (teores dos íons Fe2+ e Fe3+), difração de raios X pelo método do pó (DRX) e espectroscopia na região do infravermelho com transformada de Fourier (FT-IR). Os teores dos íons Fe2+ e Fe3+ em todas as amostras mostram que as nanopartículas não são fases puras da magnetita ou de maguemita. A difração de raios X (DRX) pelo método do pó indicou a existência da fase cúbica de espinélio inverso, mas não permite a distinção entre a magnetita e as fases de maguemita. Baseado nos resultados de análises químicas e de DRX, as nanopartículas poderiam ser melhor caracterizadas como maguemita reduzida, a qual resulta em uma fase de maguemita contento íons Fe2+. Os tamanhos médios das nanopartículas dos óxidos estimados por DRX foram em torno de 10 nm. As analises de FT-IR mostram que as nanopartículas foram funcionalizadas com bicamadas de laurato/laurato e laurato/Pluronic. As análises de FT-IR também foram indicativos da fase maguemita. O tamanho hidrodinâmico das nanopartículas funcionalizadas medidas por PCS foi em torno de 70-90 nm para amostras a base de laurato e em torno de 100-200 nm para amostras contendo Pluronic. As medidas de potencial zeta mostraram que os fluidos magnéticos a base de bicamada de laurato apresentam melhor estabilidade coloidal do que os a base de bicamada de laurato/Pluronic. Por outro lado, o estudo da estabilidade coloidal em meio de cultura por medidas de tamanho hidrodinâmico mostra a perda da estabilidade coloidal de todas as amostras, em todas as concentrações do meio investigado. Os fluidos com bicamadas de laurato/laurato mostraram taxas mais altas de agregação no meio de cultura do que os fluidos com laurato/Pluronic. Os estudos de associação de anfotericina B com nanopartículas foram realizados somente usando as amostras com bicamadas laurato/laurato. Os resultados mostraram que a taxa de associação depende da concentração de anfotericina adicionada ao fluido magnético. Foi observado 100% de associação da anfotericina na faixa da concentração nanopartículas/anfotericina usadas, que por sua vez são adequadas para posteriores estudos in vivo
55

Monitoramento de antifúngicos em plasma e líquor de pacientes portadores de meningite criptocócica e AIDS através de cromatografia líquida de alta eficiência UV/Vis / Antifungal monitoring in plasma and CSF of cryptococcal meningitis in patients with AIDS by HPLC UV/Vis

Grazziela Samantha Perez 17 December 2007 (has links)
Desenvolveram-se métodos bioanalíticos para determinação de anfotericina B e fluconazol em apenas 200 L de plasma e líquor (LCR) através da cromatografia líquida de alta eficiência (CLAE UV-VIS). A anfotericina B foi determinada através de CLAE-VIS utilizando p-nitrofenol como padrão interno, após purificação das matrizes biológicas com acetonitrila, seguida da análise em coluna Nova Pak C18 (150 x 3,9mm, 4 micron) e fase móvel constituída por tampão acetato 0,1M pH 5,0 e acetonitrila (50:50,v/v) 0,5mL/min em 385nm; o tempo de corrida foi 15 min. Através da validação o método mostrou-se robusto com 0,2-25,0 µg/mL(linearidade, r2 0,9999), LD 0,1 µg/mL, precisão (5,4% e 6,9%), exatidão expressa através do erro sistemático (3,3% e 2,2%): intra e interdias). Os estudos de estabilidade evidenciaram 1,0% para o erro sistemático e 3% de precisão na bandeja (tempo e condição de análise por 24 h), e os ciclos de congelamento evidenciaram boa estabilidade uma vez que todos os ensaios foram realizados em Laboratório de luz amarela. O fluconazol foi determinado através de CLAE-UV utilizando carbamazepina como padrão interno, após purificação das matrizes biológicas pela extração líquido-líquido com diclorometano em meio alcalino, seguido da análise em coluna Nova Pak C18 (150 x 3,9mm, 4 micron) e fase móvel constituída por água UP e acetonitrila (70:30,v/v) 0,5mL/min em 210nm; o tempo de corrida foi 15 min. O método mostrou-se robusto com 0,2-250 µg/mL(linearidade, r2 0,9998), LD 0,1µg/mL, com boa recuperação absoluta (98%) e relativa (100%), precisão 0,5%/1,3%, exatidão expressa através do erro sistemático (1,2%). Evidenciou-se ótima estabilidade para os extratos em bandeja (tempo e condição de análise por 24 h), na longa duração (20° C, 9 meses) e através dos ciclos de congelamento. Investigaram-se 21 pacientes adultos de ambos os sexos portadores de meningite criptocócica com AIDS após internação emergencial em terapia de alta dose com anfotericina B (1mg/Kg) e fluonazol (400 mg, 12/12 horas) durante 12 semanas. O monitoramento das concentrações de anfotericina B e fluconazol no plasma e no LCR forneceram as razões que permitiram estimar a penetração dos antifúngicos no SNC. Obtiveram-se concentrações de anfotericina B, médias (IC95%): 2,30 (0,02-5,08) µg/mL no plasma e 0,30 (0,19-0,36) µg/mL no LCR. As concentrações do fluconazol, médias (IC95%) foram: 31,7 (20,1-43,3) µg/mL no plasma e 19,4 (11,1-27,7) µg/mL no LCR. Com base nos resultados obtidos conclui-se que a penetração da anfotericina B foi insuficiente (10-27%), enquanto que a do fluconazol mostrou-se adequada com valores médios (IC95%) de 67 (47-87) %. / Analytical methods were developed to determine amphotericin B and fluconazole in only 200 L of plasma and in cerebrospinal fluid (CSF) by liquid chromatography (HPLC UVVIS). Amphotericin B was determined by HPLC - VIS using p-nitrophenol as internal standard, after the purification of biological matrices using acetonitrile, followed by chromatographic analysis in a Nova Pak C18 column (150 x 3.9mm, 4 micron) and mobile phase consisting of acetate buffer 0.1M pH 5.0 plus acetonitrile (50:50,v/v) 0.5mL/min at 385nm; the run time required was 15 min. Bioanalytical method validated showed robustness, 0.2-25,0µg/mL (linearity, r2 0.9999), DL 0.1µg/mL, precision (5.4%/6.0%), accuracy expressed as systematic error (3.3%/2.2%). The stability was investigated, error systematic was 1% for the vials on the rack (time and conditions of drug analysis, 24h). Thawing cycles showed good stability after three freezing-thawing cycles. All procedures were performed under yellow light at room temperature. Fluconazole was determined by HPLC - UV using carbamazepine as internal standard, after the purification of biological matrices using liquid-liquid extraction in alkaline medium, followed by chromatographic analysis in a Nova Pak C18 column (150 x 3.9mm, 4 micron) and mobile phase consisting of purified water plus acetonitrile (70:30,v/v) 0.5mL/min at 210nm; the run time required was 15 min. Bioanalytical method validated showed robustness, 0.2-250 µg/mL(linearity, r2 0.9998), DL 0.1µg/mL. Absolute recovery was 98% and relative recovery was 100%, intra/interday precision were 0,5/-1,3%; accuracy expressed as systematic error were 1.2%/1.2%.and relative recovery was 100%. Good stability for the vials on the rack (time and conditions of drug analysis, 24h) and long term stability (at 20o C for 9 months) were demonstrated. Also thawing cycles showed good stability after three freezing-thawing cycles. Twenty one adult patients of both sex were investigated. Inpatients with meningitis by Cryptococcus neoformans with AIDS were under high dose therapy with amphotericin B 1mg/Kg plus fluonazole 400 mg, every 12h during 12 weeks. Therapeutic monitoring of amphotericin B and fluconazole in plasma and in CSF showed ratios that indicate the penetration of antifungal drugs into CNS. Mean (CI95%) data were for amphotericin B 2.30 (0.02-5.08 ) µg/mL in plasma and 0.30 (0.19-0.36) µg/mL in CSF. Fluconazole showed 31.7 (20.1-43.3) µg/mL in plasma and 19.4 (11.1-27.7) µg/mL in CSF. Based on data obtained we conclude that the penetration of amphotericin B was poor (10-27%) while fluconazole was adequate 67% (47-87%), mean (CI95%).
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Avaliação da criptocococe experimental sistêmica em camundongos BALB/c e terapêutica com anfotericina B, fluconazol e associação. / Evaluation of experimental systemic cryptococcosis in BALB/c mice, and its treatment with amphotericin B and fluconazole, alone and in association.

Eriques Gonçalves da Silva 16 October 2007 (has links)
A criptococose clinica foi observada por volta do primeiro dia da inoculação e a sobrevida dos animais 15 dias após-inoculação (PI). Isolamos C. neoformans no cérebro a partir do 5º dia (PI) e no pulmão a partir 11º dia (PI). No 1º dia (PI) observamos por meio do tecido cerebral que já havia um quadro inicial de infecção, presença de edema, que evoluiu durante todo o período. C. neoformans foi visualizado primeiramente nos vasos capilares, o que nos leva a sugerir que seja esta rota importante para a entrada da levedura no órgão. A meningite aguda aconteceu por volta do 7º dia quando visualizamos o microrganismo na meninge e com um discreto infiltrado inflamatório. A partir do 13º dia a doença evoluiu para crônica permanecendo até o óbito dos animais. A monoterapia com anfotericina B (AMB) reduziu a sobrevida dos animais, enquanto que, o tratamento isolado com fluconazol (FLC) prolongou a mesma. A associação AMB-FLC foi eficaz, quando iniciamos o tratamento 24 horas (PI), enquanto que, o mesmo tratamento iniciado a partir do 7º dia quando já tínhamos um quadro compatível de meningite aguda não foi satisfatório. É importante ressaltar que os resultados descritos foram referentes à inoculação com isolado sensível in vitro ao fluconazol, enquanto que, o tratamento não resultou em êxito quando empregamos isolado resistente in vitro ao fluconazol. / Clinical cryptococcosis was observed on day 1 postinoculation (PI), and the animals survived until day 15 PI. C. neoformans was isolated from brain tissue starting on day 5 PI, and from lung tissue starting on day 11 PI. On day 1 PI, signs of infection were already observed in brain tissue, with presence of edema, which evolved throughout the period. C. neoformans was first seen in the capillaries, suggesting that this is an important route for the entrance of the yeast into this organ. Acute meningitis occurred around day 7 PI, when the microorganism was observed in the meninges, along with a discrete inflammatory infiltrate. From day 13 PI onward the disease became chronic, persisting until the death of the animals. Treatment with amphotericin B (AMB) alone shortened the animals\' survival, while treatment with fluconazole (FLC) alone lengthened it. Treatment with the two drugs in association was effective when treatment was begun at 24 hours PI, however, when treatment was begun at day 7 PI, already with signs of acute meningitis, the effectiveness was unsatisfactory. It is important to emphasize that these results relate to inoculation with an isolate susceptible in vitro to fluconazole, while the treatment was not effective for an isolate resistant in vitro to fluconazole.
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Determinação da sensibilidade de isolados de Leishmania a antimoniato de meglumina, anfotericina B e tamoxifeno. / Determination of the sensitivity of Leishmania isolates to meglumine antimoniate, amphotericin B and tamoxifen.

Rogéria Cristina Zauli Nascimento 24 June 2009 (has links)
Nesse trabalho avaliamos a sensibilidade a drogas in vitro de alguns isolados obtidos de pacientes brasileiros com leishmaniose cutânea. O microteste de MTT modificado mostrou-se eficaz para avaliação da sensibilidade in vitro de promastigotas de Leishmania e macrófagos de medula como modelo de infecção por L. (V.) braziliensis. A atividade de tamoxifeno e anfotericina B foi similar entre os isolados de Leishmania avaliados. Foi observada uma variação maior da sensibilidade ao Glucantime®, sendo que os isolados de L. (V.) braziliensis apresentaram maior sensibilidade a essa droga. Não foi observada correlação da resposta clínica dos pacientes ao tratamento com a atividade in vitro. Avaliamos também a eficácia de tamoxifeno no tratamento de camundongos BALB/c infectados com L. (V.) braziliensis. Observamos que 20 ou 30 mg/kg/dia de tamoxifeno por 15 dias resultou em redução no tamanho das lesões e carga parasitária em comparação com animais controle.Um isolado apresentou morfologia flagelar distinta daquela observada em promastigotas típicos de Leishmania. / In this work we evaluated the in vitro sensitivity to drugs of some isolates from Brazilian patients with cutaneous leishmaniasis. The modified MTT microtest was effective for evaluation of in vitro sensitivity of Leishmania promastigotes and macrophages from bone marrow as a model of infection by L. (V.) braziliensis. The activity of tamoxifen and amphotericin B was similar among isolates of Leishmania evaluated. Sensitivity to Glucantime®, was more variable with isolates of L. (V.) braziliensis presenting higher sensitivity to the drug. There was no correlation between clinical response to treatment with in vitro activity. We have also evaluated the effectiveness of tamoxifen in the treatment of BALB/c mice infected with L. (V.) braziliensis and observed that 20 or 30 mg/kg/day of tamoxifen for 15 days resulted in reduction in the size of lesions and parasite load when compared with control animals. One of the isolates presented atypical flagellar morphology.
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Etude de l’état d’agrégation de l’amphotéricine B dans différents systèmes d’administration / Study of amphotericin B molecular aggregation into different carrier system

Silva, André 19 October 2017 (has links)
L'amphotéricine B (AmB) est une molécule utilisée en thérapeutique pour ses propriétés antifongiques remarquables. Cependant, ses caractéristiques physico-chimiques très particulières, rendent difficile la conception et la fabrication de systèmes thérapeutiques chargés en AmB qui soient simultanément efficaces et peu toxiques. La littérature montre qu'il existe une relation intime entre la façon dont l’AmB est associée au système transporteur et les effets pharmacologiques et toxicologiques qui sont observés. Malgré de très nombreuses études, l’état d’association des molécules d’AmB dans les différentes formulations commercialisées contenant de l'AmB n’est toujours pas connus avec suffisamment de précision. Pour cette raison, le but de ce travail expérimental est de caractériser différents systèmes contenant de l'AmB, dans l’objectif de prédire les effets biologiques induits par l’état d’association de cette molécule à ces systèmes supramoléculaires. Dans ce travail, nous avons caractérisé un système micellaire original ainsi que deux autres produits similaires tout en les comparant. De plus, nous avons étudié les mécanismes par lesquels se forment des super-agrégats d’AmB par l'augmentation de la stabilité des systèmes chauffés. Dans un second temps et pour la première fois, la capacité de l’AmBisome®, à former des super-aggrégats a également été caractérisée et testée. Enfin, l'incorporation de l'AmB dans des systèmes de type nano- et micro-émulsion a été étudiée, avant d’être appliquée au traitement des maladies oculaires fongiques et de la leishmaniose viscérale. Les principales techniques utilisées pour la caractérisation physico-chimiques de l’état d’agrégation ont été : la spectroscopie électronique (UV-Vis), le dichroïsme circulaire (DC) et la diffusion dynamique de la lumière (DLS). La calorimétrie à titrage isotherme (ITC) a été utilisée afin de tenter de mesurer l’énergie de formation des super-agrégats. De plus, un dérivé soluble de l’AmB a été développé et caractérisé par spectroscopie de masse atomique, infrarouge, UV-Vis et DC. Afin de disposer d’un système d’administration adéquat, ce dérivé soluble a été ensuite incorporé dans une micro-émulsion. Au total, l’ensemble des travaux expérimentaux conduits, montrent que l’état d'agrégation moléculaire de l’AmB dépend très largement du système d’administration utilisé, ainsi que des procédés par lesquels l’AmB est associées à ces systèmes. Ces résultats ont une réelle importance pratique puisque la littérature montre sans ambiguïté que l'efficacité du médicament ainsi qu’à sa toxicité dépendent étroitement de l'état d'agrégation de l’AmB. Ainsi, dans la nanoémulsion, l’AmB se trouve dans des états agrégés et multi-agrégés. Au contraire, dans la micro-émulsion, l’AmB se présente plutôt sous forme « monomère ». Une fois chauffés, les systèmes micellaires forment des super-agrégats d'AmB, tandis que les liposomes étudiés sont incapables de donner naissance à cette structure supramoléculaire. Enfin, le dérivé soluble d'AmB que nous avons préparé présente des caractéristiques distinctes par rapport à la molécule d'origine. Cependant, une fois associé à une microémulsion, son état d'agrégation est modifié et redevient similaire à celui de l'AmB originale, comme l’indique les études en UV-Vis et en DC. On peut donc conclure de ce travail que l'état d'agrégation d'AmB varie considérablement en fonction du type de système d’administration utilisé, de la concentration de l’AmB ainsi que du mode d'incorporation de la molécule, y compris pour un même système. Enfin, ce travail a permis la mise au point d’un dérivé soluble original de l’AmB qui offre la possibilité d’utiliser des formulations aqueuses adaptées à différentes voies d’administration et pourrait renouveler l’intérêt de cette molécule ancienne dans le traitement de différentes pathologies fongiques pour lesquelles il n’existe pas de formulations réellement adapatées. / The amphotericin B (AmB) is a drug of peculiar physicochemical features: being amphiphilic and amphoteric. These characteristics turn difficult the drug load into therapeutic systems. AmB is currently available in the market as micelles, liposomes and lipid complex for injection. The literature show that there is an intimate correlation between the AmB bound to the carrier and its biological response. However, there is a deficiency concerning the physicochemical characterization of the available AmB-containing products. Therefore, the aim of this work was to characterize AmB-containing carriers seeking a prediction to its biological response. The AmB-containing micellar system was the first product available for clinical use. The patent of this product has already expired some years ago. In this work we have characterized the original system and two other similar micellar products. In addition, we studied the stability increase of heated systems, by the formation of AmB “super-aggregates”. AmBisome®, an AmB-containing liposomal system, was also characterized and, for the first time, tested for the possibility of super-aggregates formation. The AmB incorporation into nano and microemulsion systems was presented and the physicochemical characteristics evaluated, focusing mainly on applications for the treatment of fungal ocular diseases and also for visceral leishmaniasis. The main techniques used for characterization were electronic spectroscopy, circular dichroism and dynamic light scattering. The isothermal titration calorimetry (ITC) was used as an attempt to measuring the super-aggregates energy formation. Besides, an AmB soluble derivative was developed and characterized by atomic mass spectroscopy, infra-red, UV-Vis and circular dichroism. Then, this AmB-derivative was loaded into a microemulsion as a vehiculation strategy. The overall results show that the AmB-containing systems presented different molecular aggregation states that depends on the carrier, the way the drug is incorporated and also on the diluent. According to the literature, the aggregation state is associated with both, drug efficiency and toxicity. In nanoemulsion systems, the drug is found aggregated and multi-aggregated. In microemulsions, AmB is loaded as monomers. The heated micellar systems form AmB super-aggregates while the liposomal system is unable to form such molecular structure. Moreover, the AmB soluble derivative presented distinct features when compared to the original molecule. However, once incorporated into the microemulsion, the aggregation state is similar to that of the original AmB molecule, as supported by UV-Vis and circular dichroism results. It can be concluded that the AmB aggregation state varies according to the kind of carrier, the drug concentration and also the way of drug incorporation, even into one same carrier. Finally, the soluble derivative opens the possibility for drug carrying into aqueous vehicles for the treatment of many diseases by different administration routes.
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Evaluation of ligand modified poly (N-Isopropyl acrylamide) hydrogel for etiological diagnosis of corneal infection

Shivshetty, N., Swift, Thomas, Pinnock, A., Pownall, D., MacNeil, S., Douglas, I., Garg, P., Rimmer, Stephen 24 March 2022 (has links)
Yes / Corneal ulcers, a leading cause of blindness in the developing world are treated inappropriately without prior microbiology assessment because of issues related to availability or cost of accessing these services. In this work we aimed to develop a device for identifying the presence of Gram-positive or Gram-negative bacteria or fungi that can be used by someone without the need for a microbiology laboratory. Working with branched poly (N-isopropyl acrylamide) (PNIPAM) tagged with Vancomycin, Polymyxin B, or Amphotericin B to bind Gram-positive bacteria, Gram-negative bacteria and fungi respectively, grafted onto a single hydrogel we demonstrated specific binding of the organisms. The limit of detection of the microbes by these polymers was between 10 and 4 organisms per high power field (100X) for bacteria and fungi binding polymers respectively. Using ex vivo and animal cornea infection models infected with bacteria, fungi or both we than demonstrated that the triple functionalised hydrogel could pick up all 3 organisms after being in place for 30 min. To confirm the presence of bacteria and fungi we used conventional microbiology techniques and fluorescently labelled ligands or dyes. While we need to develop an easy-to-use either a colorimetric or an imaging system to detect the fluorescent signals, this study presents for the first time a simple to use hydrogel system, which can be applied to infected eyes and specifically binds different classes of infecting agents within a short space of time. Ultimately this diagnostic system will not require trained microbiologists for its use and will be used at the point-of-care. / We gratefully acknowledge support for this research by the Well- come Trust which provided funding for Shivshetty, Swift and Pinnock (Grant 0998800/B/12/Z).
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Generation and Use of Functional Hydrogels That Can Rapidly Sample Infected Surfaces

Swift, Thomas, Pinnock, A., Shivshetty, N., Pownall, David, MacNeil, S., Douglas, I., Garg, P., Rimmer, Stephen 09 August 2022 (has links)
Yes / This paper outlined our method for developing polymer-linked contact lens type materials for rapid detection and differentiation of Gram-positive, Gram-negative bacteria and fungi in infected corneas. It can be applied to both model synthetic or ex-vivo corneal models and has been successfully trialed in an initial efficacy tested animal study. First a hydrogel substrate for the swab material is selected, we have demonstrated selective swabs using a glycerol monomethacrylate hydrogel. Alternatively any commercial material with carboxylic acid functional groups is suitable but risks nonspecific adhesion. This is then functionalised via use of N-hydroxysuccinimide reaction with amine groups on the specified highly branched polymer ligand (either individually gram negative, gram positive or fungal binding polymers or a combination of all three can be employed for desired sensing application). The hydrogel is then cut into swabs suitable for sampling, used, and then the presence of gram positive, game negative and fungi are disclosed by the sequential addition of dyes (fluorescent vancomycin, fluorescein isothiocyanate and calcofluor white). In summary this method presents: Method to produce glycerol monomethacrylate hydrogels to minimize nonspecific binding Methods of attaching pathogen binding highly branched polymers to produce selective hydrogel swabs Method for disclosing bound pathogens to this swab using sequential dye addition

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