Previously it has been shown that cultures of Plasmodium falciparum died following exposure to a febrile temperature of 40°C, as demonstrated by a decrease in parasitemia of the following generation. In the current study, the effect of 40°C treatment on culture media, erythrocytes, and parasite glucose consumption, were ruled out as possible influences on parasite death, demonstrating that 40°C impacted the parasites directly. Metabolic profiling of DNA synthesis, protein synthesis, and glucose utilization during exposure to 40°C clearly indicated that febrile temperatures had direct effect on major metabolic pathways and parasite development, beginning 20-24 hr after erythrocyte invasion. The ring stages were relatively refractory to heat and recovered completely if returned to 37°C. The mechanism of parasite death was investigated for evidence of an apoptosis-like pathway in cells treated with 40°C, chloroquine, and staurosporine. Lack of typical physiological hallmarks, namely, caspase activation, characteristic mitochondrial membrane potential changes, and DNA degradation as indicated by DNA laddering, eliminated ‘classical’, apoptosis as a mechanism of parasite death. Parasites dying under the influence of 40°C, staurosporine, and chloroquine initially appeared pyknotic in light and electron microscopy, as in apoptosis, but eventual swelling and lysis of the food vacuole membrane led to secondary necrosis. Initially, chloroquine did induce DNA laddering, but it was later attributed to occult white blood cell contamination. While not apoptosis, the results do not rule out other forms of temperature-induced programmed cell death.

Association of Commonwealth Universities. Commonwealth Scholarship Commission. United Kingdom.

Female adults of many mosquito species possess distinct physiological features adapting to blood feeding for successful reproduction. The disease pathogens that are transmitted by mosquitoes have evolved to take advantages of the indispensable blood feedings to complete their transmission cycles and to survive attacks from the mosquito's innate immune system. Normal egg development and mosquito immunity are tightly controlled by tissue- and stage-specific gene expression and coordinated by many signal molecules in the mosquito. Understanding gene regulation affecting mosquito reproduction and malaria parasites infection is of paramount importance for developing novel malaria control strategies. A growing body of evidence indicates that microRNAs (miRNAs) are involved in egg maturation and immune reactions against invading pathogens in mosquitoes. However, the molecular mechanisms by which specific miRNAs selectively modulate reproduction and the survival of pathogens are largely unknown. The miRNA-induced gene-silencing pathway in mosquitoes was mostly extrapolated from the studies of flies. To explore the dynamics of miRNAs in reproduction, I used small RNAs sequencing to monitor miRNAs expression and their association with Argonaute 1 (Ago1) and Argonaute 2 (Ago2) in the malaria mosquito Anopheles gambiae (An. gambiae) during the 72-h period immediately after blood feeding. I found the abundance and Ago loading of most of the mature miRNAs were relatively stable after blood ingestion. However, miRNAs of the miR-309/286/2944 cluster were considerably upregulated after blood feeding. I confirmed that miR-309 is essential for normal egg development by depletion of endogenous miR-309 with a specific antagomir. In addition, my results showed that the Ago association of some miRNAs was not proportional to their cellular abundance implying additional regulation at miRNA integration. To investigate the functional roles of miRNAs and define context-dependent miRNA-mRNA interactions during the reproductive process, I have applied an innovative experimental approach to study miRNA-mRNA interactome. CLEAR (covalent ligation of endogenous Argonaute-bound RNAs)-CLIP can generate miRNA-mRNA chimeras from UV-irradiation stabilized Ago-miRNA-mRNA complex. My results have defined tens of thousands of miRNA-mRNA interactions in mosquitoes, including novel targets for mosquito-specific miRNAs. Verification of the predicted interactions using mRNA-seq, ribosome-profiling, and luciferase reporter assay revealed a reliable miRNA-mRNA interaction network. Based on the detected interactions, I refined the paring rules for mosquito miRNAs and illustrated the dynamic pairing between different regions of miRNAs with their targets in vivo. The miRNA-mRNA interactions were compared using this approach at multiple time points before and after blood feeding. Importantly, this study showed that the interactions were dynamic and enriched in genes that are involved in metabolisms, supporting the proposed functions of miRNAs in coordinating the gene regulation in mosquito reproduction. Plasmodium falciparum (P. falciparum) is a major human malaria parasite. To understand the functions of miRNAs in the mosquito resistance to Plasmodium infection, we analyzed the miRNA-mRNA interactions after female mosquitoes taking a P. falciparum-infected blood meal or an uninfected blood meal. Comparison of the interactions revealed enhanced miRNA-mRNA interactions after P. falciparum infection involving a group of immunity-related genes. In summary, this study has provided a systematic view and significantly advanced our understanding of the miRNA functions in mosquito reproduction and P. falciparum infection. / PHD

Die Malaria ist heute noch immer die bedeutendste parasitäre Infektionskrankheit des Menschen. Hiervon sind in Endemiegebieten neben Kleinkindern insbesondere schwangere Frauen betroffen. P. falciparum weist eine hohe genetische Diversität auf. So sind in Endemiegebieten Infektionen mit P. falciparum in der Regel polyklonal. Man spricht in diesen Fällen von der Multiplizität der Infektion. Bei Schwangeren sequestrieren mit P. falciparum infizierte Erythrozyten, die spezifische Oberflächenproteine exprimieren, in der Plazenta. Hierdurch bedingt können pathologische Schwangerschafts-verläufe klinische Manifestationsformen der Malaria darstellen. Um die Diversität von P. falciparum und die Multiplizität der Infektion bei schwangeren Frauen zu erforschen, wurden in einer Querschnittsstudie im holoendemischen Malariagebiet von Agogo in Ghana über den Zeitraum von einem Jahr 474 Gebärende mit einer nachgewiesenen plazentaren Infektion von P. falciparum untersucht. Hierzu wurden die Gene, die für das "Merozoiten-Oberflächen-Protein-1" (msp-1) und "Merozoiten-Oberflächen-Protein-2" (msp-2) kodieren, aus peripher und plazentar gewonnen Isolaten typisiert. Plazentar gewonnene Isolate waren im Vergleich zu peripher gewonnenen mit einer signifikant höheren Prävalenz an polyklonalen Infektionen und einer höheren Multiplizität der Infektion assoziiert. Die höchste Multiplizität der Infektion wurde bei Erstgebärenden und jüngeren Patientinnen beobachtet. Mit zunehmendem Alter und einer höheren Anzahl an vorangegangenen Schwangerschaften fielen signifikant sowohl die Multiplizität der Infektion als auch die Parasitendichte. Zudem wurde eine hohe Korrelation zwischen der Multiplizität der Infektion und der Parasitendichte nachgewiesen. Weder das Alter noch die Parität beeinflussten diese Korrelation. Der Einfluss von Alter und Parität auf die Multiplizität der Infektion konnte somit nicht unabhängig von der Parasitendichte nachgewiesen werden. Multivariate Analysen zeigten aber, dass es unabhängig von der Parasitendichte bei plazentaren Infektionen mit zwei und mehr als zwei Klonen im Vergleich zu monoklonalen plazentaren Infektionen mit einer höheren Wahrscheinlichkeit zu einer Frühgeburt kam. Dies betraf insbesondere Erstgebärende und Frauen mit submikroskopischen plazentaren Infektionen. Ob bei polyklonalen Infektionen eine Sequestration von P. falciparum in der Plazenta durch alle oder nur durch einen Teil der zahlreichen Genotypen geschieht, die an einer Infektion bei Schwangeren beteiligt sind, ist nicht entgültig geklärt. Es wurden aus zusammengehörenden plazentar und peripher gewonnenen P.-falciparum-Isolaten die Verteilungsmuster der Genotypen verglichen. Zwar korrelierte die Multiplizität der Infektion plazentarer und peripherer Isolate, die Genotypenmuster der Plazenta und der Peripherie waren jedoch deutlich unterschiedlich. Nur in 12% der Fälle konnte eine Genotypisierung eines peripher gewonnenen Isolates das klonale Gesamtbild der Infektion nachweisen. In 67% der Fälle waren neben identischen Genotypen wenigstens in einem der beiden Isolate unterschiedliche Genotypen nachweisbar. Einzelne spezifische Genotypen traten in der gesamten Untersuchungsgruppe öfter in der Plazenta als in der peripheren Blutprobe auf. Bei Frauen, die mit den Genotypen der Allelfamilie FC27 infiziert waren, lagen signifikant häufiger klinischen Manifestationen der Malaria vor. So konnte in multivariaten Analysen eine Assoziation zwischen FC27 und einer Frühgeburtlichkeit nachgewiesen werden. Darüber hinaus war FC27 zumindest in univariater Analyse mit einer Anämie und einem verminderten Geburtsgewicht assoziiert. Dies konnte insbesondere für Primiparae und für Gebärende mit submikroskopischen plazentaren Infektionen beobachtet werden. / Malaria is still one of the most considerable parasite infections of the human being. Pregnant women are at an increased risk in endemic areas. P. falciparum shows a high genetic diversity. In endemic areas infections with P. falciparum are very often polyclonal. They are described as multiple Infections or as the multiplicity of infection. In pregnant women P.-falciparum-infected-erythrocytes which exprimate specific surface proteins sequester in the placental tissue. Often this is the course of preterm delivery, low birth weight and anaemia. To investigate the diversity of P. falciparum and the multiplicity of infection in pregnant women a cross-sectional study was conducted in the holoendemic area of Agogo in Ghana. In this study over a period of one year 474 labouring women infected with placental P.-falciparum where investigated. To examine the diversity and the multiplicity of infection merozoite surface protein-1 (msp1) block 2 and merozoite surface protein-2 (msp2) genotypes were determined in Isolates from peripheral and placental blood samples. The study showed that in comparision to isolates of peripheral blood samples isolates of placental blood samples where associated with a significant higher prevalence of polyclonal infections and a higher multiplicity of infection. The highest multiplicity of infection was found among primiparae and young women. With age and parity multiplicity of infection as well as parasite density decreased. In addition a high correlation between the multiplicity of infection and parasite density could be demonstrated. Age and parity did not influence this correlation. Thus the influence of age independent from parity on the multiplicity of infection could not be proved. However, multivariate analyses showed, that independently from parasite density placental Infections with two or more clones were in comparison to monoclonal Infections associated with a higher probability of preterm delivery. This was the case especially in primiparae and in women with submicroscopical placental Infection. Presently it is not clear, whether all or only a subset of co-infecting genotypes sequester in the placental tissue. To address this issue the genotype distribution of matched placental and peripheral P. falciparum isolates where investigated. While the multiplicity of infection of placental and peripheral isolates correlated the genotype pattern of the placenta and the periphery differed extensively. Only 12% genotyping of a peripheral Isolate showed the entire picture of the infection. In 67% of the cases despite finding identical genotypes differing genotypes in at least one of the two Isolates were detectable. Specific genotypes appeared more often in the placental than in the peripheral Isolate. In women, who were infected with genotypes of the allelic family FC27 clinical manifestation of malaria were observed more often. In multivariate analysis an association between FC27 and a preterm delivery was established. Beside this at least in univariate analyses FC27 was associated with low birth weight and anaemia. This was the case especially for primiparae and labouring women with submicroscopic placental infections.

Die Infektion mit dem Erreger der Malaria tropica, Plasmodium falciparum, verläuft individuell unterschiedlich. Während manche der Infizierten rasch an einer komplizierten Malaria versterben, zeigen andere keinerlei Symptomatik, obwohl jahrelang eine Parasitämie besteht. Was diese Individuen voneinanderen unterscheidet, ist weitgehend unbekannt. Morbidität und Mortalität der Erkrankung sind von der Auseinandersetzung zwischen Wirt und Parasit abhängig, die von exogenen und endogenen Faktoren beeinflußt wird. Unter den endogenen Faktoren spielen die genetischen Determinanten, die sowohl an angeborenen als auch an erworbenen Resistenz- und Immunmechanismen beteiligt sind, eine besondere Rolle. In den hier zusammengefaßten Arbeiten wurden als Determinanten der angeborenen Resistenz gegenüber Malaria die Sichelzellanämie, Alpha-Thalassämie, G6PD-Mangel und der HLA-Klasse-II-Polymorphismus und als genetische Einflußfaktoren von erworbenen Immunmechanismen Varianten des TNF-Promotors, von ICAM-1 und iNOS untersucht. Die Arbeiten unterstützen die Hypothese, daß die Interaktion von Mensch und Plasmodien zu einer ständigen gegenseitigen Beeinflussung und Anpassung geführt hat. Die koevolutonäre Veränderung der Genome der beiden Organismen ist wahrscheinlich mitverantwortlich für die unterschiedliche geographische Verteilung von Genvarianten sowohl des Menschen als auch der Plasmodien und scheint auch heute noch Teil einer komplexen und dynamischen Anpassung von Wirt und Parasit zu sein. / The manifestation of an infection with Plasmodium falciparum, the pathogen of malaria, is individually different. Some indiviuals have a high risk of developing severe malaria, whereas others remain asymptomatic despite a long-lasting parasitemia. The basis of these differences is unknown. Morbidity and mortality of malaria are dependent on the interaction between the host and the parasite which is influenced by exogenic and endogenic factors. The latter are determined by genetic elements involved in innate and acquired mechanisms of resistance and immunity. The studies summerized here address genetic determinants of innate resistance against malaria (sickle cell trait, alpha-thalassemia, G6PD deficiency, blood groups and HLA class II alleles) and those of acquired immunity (variants of the TNF promoter, ICAM-1, and iNOS). The results support the view that the interaction between humans and plasmodia has led to continuous mutual influences and adaptations. Probably, the co-evolution of the genomes of both organisms is jointly responsible for the different geographical distribution of parasitic and human gene variants. This process seems to be part of an ongoing complex and dynamic adaptation of the host and the parasite.

Neste estudo avaliamos a resposta imune humoral de indivíduos naturalmente expostos à malária em áreas endêmicas no Brasil. Os anticorpos IgG, IgG1, IgG2, IgG3, IgG4, IgM, IgE e IgA anti-formas eritrocitárias de Plasmodium falciparum foram determinadas por ELISA. Anticorpos IgG, IgG1, IgG2 de alta avidez e IgG3 de baixa avidez predominaram nos indivíduos sem complicações de malária ou assintomáticos, enquanto anticorpos IgG4, IgE e IgM predominaram nos indivíduos com complicações clínicas por malária. Os resultados mostram que mesmo em regiões com transmissão instável de malária pode ser observado o desenvolvimento de imunidade protetora quando anticorpos apropriados são produzidos / In this study, we have evaluated the humoral immune response of individuals naturally exposed to malaria living in endemic areas of Brazil. We determined IgG, IgG1, IgG2, IgG3, IgG4, IgM, IgE and IgA antibodies against Plasmodium falciparum blood stages by ELISA. We observed that the level of high avidity IgG, IgG1 and IgG2 and low avidity IgG3 antibodies were higher in asymptomatic individuals or with uncomplicated malaria, while IgG4, IgE and IgM antibodies were higher in individuals with complicated malaria. Taken together the results showed that even in unstable malaria regions it can be observed the development of protective immunity against malaria when appropriate antibodies are produced

Neste estudo avaliamos a resposta imune humoral de indivíduos naturalmente expostos à malária em áreas endêmicas no Brasil. Os anticorpos IgG, IgG1, IgG2, IgG3, IgG4, IgM, IgE e IgA anti-formas eritrocitárias de Plasmodium falciparum foram determinadas por ELISA. Anticorpos IgG, IgG1, IgG2 de alta avidez e IgG3 de baixa avidez predominaram nos indivíduos sem complicações de malária ou assintomáticos, enquanto anticorpos IgG4, IgE e IgM predominaram nos indivíduos com complicações clínicas por malária. Os resultados mostram que mesmo em regiões com transmissão instável de malária pode ser observado o desenvolvimento de imunidade protetora quando anticorpos apropriados são produzidos / In this study, we have evaluated the humoral immune response of individuals naturally exposed to malaria living in endemic areas of Brazil. We determined IgG, IgG1, IgG2, IgG3, IgG4, IgM, IgE and IgA antibodies against Plasmodium falciparum blood stages by ELISA. We observed that the level of high avidity IgG, IgG1 and IgG2 and low avidity IgG3 antibodies were higher in asymptomatic individuals or with uncomplicated malaria, while IgG4, IgE and IgM antibodies were higher in individuals with complicated malaria. Taken together the results showed that even in unstable malaria regions it can be observed the development of protective immunity against malaria when appropriate antibodies are produced

L’objectif du travail effectué était la recherche de nouvelles substances actives d’origine végétale, présentant soit une activité antiplasmodiale soit une activité antifongique. Cette étude a été menée suivant deux stratégies différentes: l’étude de remèdes traditionnels antipaludiques identifiés suite à des enquêtes ethnopharmacologiques, et la mise en évidence des propriétés antifongiques d’huiles essentielles grâce à une stratégie bioinspirée. La première partie du travail a permis de mettre en évidence le rôle d’un quassinoïde connu, la simalikalactone D, dans l’activité antipaludique d’une tisane de jeunes feuilles fraîches de Quassia amara L. (Simaroubaceae). Dans le cas de la décoction de rameaux de Psidium acutangulum DC. (Myrtaceae), c’est cette fois un mélange de flavonoïdes glycosylés qui est responsable de l’activité du remède. Dans le cadre de la recherche de nouvelles substances antifongiques, le criblage effectué a permis d’identifier de nombreuses huiles essentielles présentant des activités intéressantes, validant ainsi la démarche bioinspirée retenue dans ce cas. L’huile essentielle d’Otacanthus azureus (Linden) Ronse a en particulier démontré une activité remarquable, à la fois seule et en combinaison avec des antifongiques azolés. Enfin, l’étude métabolomique de la composition des huiles essentielles a permis de mettre au point un outil pouvant orienter la sélection des huiles en fonction des données obtenues en GC/MS dans l’optique de la recherche de nouvelles substances antifongiques. Ce travail démontre donc la validité des stratégies retenues – ethnopharmacologie et bioinspiration – dans la recherche de nouvelles substances bioactives. / The aim of this work was to search for new bioactive compounds, displaying either antiplasmodial or antifungal activity. Two strategies were developed here: the evaluation of traditional remedies identified as antimalarial through ethnopharmacological studies, and the search for antifungal essential oils, the criterium being here a bioinspired approach. Our work led to the discovery that the antimalarial activity of Quassia amara L. (Simaroubaceae) fresh young leaves was due to the presence of a known quassinoid, simalikalactone D. In the case of Psidium acutangulum DC. (Myrtaceae), a flavonol glycosides mixture explained the activity observed for the decoction. The search for antifungal essential oils from the Amazonian flora led to the identification of several interesting species, thus validating our bioinspired strategy. The essential oil of Otacanthus azureus (Linden) Ronse was among the most active ones, either alone or in combination with azole drugs. Eventually, a metabolomic study of the GC/MS composition of these oils allowed us to develop a statistical tool which could help to select interesting antifungal products. This work thus demonstrates the major interest of the two strategies – ethnopharmacology and bioinspiration – for the search of new bioactive compounds.

Submitted by Cássio da Cruz Nogueira (cassionogueirakk@gmail.com) on 2017-10-18T14:51:39Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_CorrelacaoTeoresSericos.PDF: 732831 bytes, checksum: 3bf43f8f4706176b775d0e79390d6d61 (MD5) / Approved for entry into archive by Irvana Coutinho (irvana@ufpa.br) on 2017-11-08T12:16:16Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_CorrelacaoTeoresSericos.PDF: 732831 bytes, checksum: 3bf43f8f4706176b775d0e79390d6d61 (MD5) / Made available in DSpace on 2017-11-08T12:16:16Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_CorrelacaoTeoresSericos.PDF: 732831 bytes, checksum: 3bf43f8f4706176b775d0e79390d6d61 (MD5) Previous issue date: 2010 / A malária é uma das principais causas de morbidade e mortalidade no mundo, com mais de 100 milhões de casos e pelo menos um milhão de mortes por ano. É uma doença presente nos países de clima tropical e subtropical do planeta. No Brasil, ocorre principalmente na região Amazônica, onde as condições climáticas favorecem a reprodução do vetor e a disseminação da doença. Com o surgimento da resistência do vetor aos inseticidas, a falta de uma vacina eficaz e, principalmente, a resistência do plasmódio aos antimaláricos disponíveis atualmente, se observou um ressurgimento e o avanço da doença pelo mundo. Dentre os fármacos empregados no tratamento da doença se destaca a mefloquina, que apresenta elevada lipossolubilidade, estando associada especificamente a um polipetídio (apo-A1) presente nas lipoproteínas de alta densidade (HDL). Desta forma, os eritrócitos infectados tendem a se ligar às partículas de HDL circulantes para obtenção do suprimento lipídico, o que favoreceria a passagem e o acúmulo do fármaco nestes. Contudo, pacientes com malária demonstram anormalidades no perfil lipídico, como diminuição dos valores do colesterol total, HDL e LDL, elevação dos valores da lac - tato desidrogenase e aumento moderado dos valores de triglicerídeos. O objetivo do trabalho consiste na correlação entre as concentrações séricas de colesterol total, HDL, LDL e triglicerídeos com os teores séricos de mefloquina (MQ) e carboximefloquina (CMQ) em pacientes com malária por Plasmodium falciparum não complicada. Para isso foi utilizado à dosagem bioquímica, através do auto analisador Cobas-plush para a determinação dos teores séricos do colesterol e frações e triglicerídeos e a Cromatografia líquida de alta efi - ciência para determinação das concentrações séricas de mefloquina e carboximefloquina. Foi observada diferença significativa nos níveis séricos de colesterol total, e das frações HDL e LDL, as quais aumentaram com o decorrer da evolução clínica dos pacientes, que corrobora com achados na literatura e foi observada diferença significativa nos níveis séricos de triglicerídeos, os quais reduziram com a evolução clínica dos pacientes. / Malaria is a major cause of morbidity and mortality worldwide, with over 100 million cases and at least one million deaths annually. It is a disease prevalent in the countries of tropical and subtropical climate of the planet. In Brazil, it occurs mainly in the Amazon region where climatic conditions favor the breeding of the vector and the spread of disease. With the emergence of vector resistance to insecticides, the lack of an effective vaccine, and especially the resistance of plasmodia to antimalarial drugs available today, there has been a resurgence and spread of the disease worldwide. Among the drugs used to treat the disease stands to mefloquine, which has high lipid solubility, being associated to a specific polipetídio (apo-A1) present in high density lipoproteins (HDL). Thus, infected erythrocytes tend to bind to circulating HDL particles to obtain the lipid supply, which would favor the passage and accumulation of the drug in these. However, malaria patients showed abnormal lipid profile, such as decreased levels of cholesterol total, HDL and LDL cholesterol, elevated values of lactate dehydrogenase, and a moderate increase of triglyceride level. This study is the correlation between serum concentrations of total cholesterol, HDL, LDL and triglycerides in serum levels of mefloquine (MQ) and carboximefloquina (CMC) in patients with falciparum malaria not complicated. For this we used the biochemical determination through self-plush Cobas analyzer to determine the levels of serum cholesterol and triglycerides and high performance liquid chromatography for determination of serum levels of mefloquine and carboximefloquina. Significant difference in serum total cholesterol, and HDL and LDL, which increased over the course of clinical evaluation, which corroborates findings in the literature and there was significant difference in serum triglycerides, which decreased with clinical outcome of patients.

Submitted by Edisangela Bastos (edisangela@ufpa.br) on 2013-05-06T22:24:50Z No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Dissertacao_DeterminacaoMefloquinaCarboximefloquina.pdf: 1291291 bytes, checksum: 9721045117f75e0d7367df44c1ce1bd2 (MD5) / Approved for entry into archive by Ana Rosa Silva(arosa@ufpa.br) on 2013-05-09T13:47:34Z (GMT) No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Dissertacao_DeterminacaoMefloquinaCarboximefloquina.pdf: 1291291 bytes, checksum: 9721045117f75e0d7367df44c1ce1bd2 (MD5) / Made available in DSpace on 2013-05-09T13:47:34Z (GMT). No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Dissertacao_DeterminacaoMefloquinaCarboximefloquina.pdf: 1291291 bytes, checksum: 9721045117f75e0d7367df44c1ce1bd2 (MD5) Previous issue date: 2008 / A determinação das concentrações plasmáticas e eritrocitárias de mefloquina (MQ) e carboximefloquina (CMQ) foram estudadas em crianças e adultos com malária por Plasmodium falciparum não complicada no estado do Amapá. Os pacientes adultos receberam esquema oral de MQ 20 mg/kg dividido em dois dias e artesunato 4 mg/kg/dia durante três dias. Para as crianças a dose de MQ seguiu o esquema preconizado pelo manual de terapêutica da malária. As concentrações eritrocitárias de MQ e CMQ foram quantificadas por cromatografia líquida de alta eficiência no terceiro dia de tratamento (D3) e os teores plasmáticos foram mensurados no terceiro e quadragésimo segundo dia após a instituição da terapia (D3 e D42). A concentração média de MQ e CMQ no plasma de crianças em D3 foram 1,84 ± 0,83 μg/mL e 1,44 ± 0,70 μg/mL, e a eritrocitária 5,26 ± 1,46 μg/mL e 1,18 ± 0,65 μg/mL. Em D42 as concentrações plasmáticas foram 0,45 ± 0,11 μg/mL e 0,51 ± 0,10 μg/mL, respectivamente. A relação entre as concentrações eritrocitárias e plasmáticas de MQ e CMQ foram 2,86 ± 1,27 e 0,75 ± 0,26. Nos indivíduos adultos, as concentrações de MQ e CMQ no plasma foram 2,43 ± 1,13 μg/mL e 1,10 ± 0,38 μg/mL, e as eritrocitárias 5,51 ± 1,92 μg/mL e 1,08 ± 0,35 μg/mL, respectivamente. A concentração plasmática em D42 foram 0,54 ± 0,15 μg/mL e 0,58 ± 0,93 μg/mL, respectivamente. A relação hemácia:plasma para MQ foi 3,03 ± 1,56 e para CMQ 1,12 ± 0,29. O coeficiente de correlação entre as concentrações plasmáticas e eritrocitárias de MQ nas crianças foi 0,035 e nos adultos 0,0436. Para CMQ o coeficiente de correlação foi 0,8722 nas crianças e 0,5155 nos adultos. O maior acúmulo de MQ no eritrócito nos permite enfatizar a importância do mecanismo de difusão simples para a entrada do fármaco na célula em função das suas características físico-químicas. / The determination of plasmatic and erythrocyte concentrations of mefloquine (MQ) and carboxymefloquine (CMQ) were studied in children and adults with malaria by Plasmodium falciparum not complicated in the Amapa state. The adult patients received oral outline of MQ 20 mg/kg divided in two days and artesunate 4 mg/kg/day for three days. For children the dose of MQ followed the schedule recommended by the manual of malaria therapy. Concentrations of MQ and CMQ in erythrocytes were quantified by high performance liquid chromatography on the third day of treatment (D3) and plasma levels were measured in the third and second fortieth day after the institution of therapy (D3 and D42). The average concentration of MQ and CMQ in plasma of children in D3 were 1.84 ± 0.83 μg/mL and 1.44 ± 0.70 μg/mL, and in erythrocytes 5.26 ± 1.46 μg/mL and 1.18 ± 0.65 μg/mL. In D42 the plasma concentrations were 0.45 ± 0.11 μg/mL and 0.51 ± 0.10 μg/mL, respectively. The relationship between plasma and erythrocytes concentrations of MQ and CMQ were 2.86 ± 1.27 and 0.75 ± 0.26. In adults, concentrations of MQ and CMQ in plasma were 2.43 ± 1.13 μg/mL and 1.10 ± 0.38 μg/mL, and in erythrocytes 5.51 ± 1.92 μg/mL and 1.08 ± 0.35 μg/mL, respectively. The plasma concentrations in D42 were 0.54 ± 0.15 μg/mL and 0.58 ± 0.93 μg/mL, respectively. The relationship erythrocyte:plasma for MQ was 3.03 ± 1.56 and 1.12 ± 0.29 to CMQ. The correlation coefficient between plasma and erythrocytes concentrations of MQ in children was 0.035 and adults 0.0436. For CMQ the correlation coefficient in children was 0.8722 and in adults 0.5155. The higher accumulation of MQ in the red blood cells allows us to emphasize the importance of the simple diffusion for the entry of the drug in the cell because of their physical and chemical characteristics.