RESUMO
Primaquine is the mainstream antimalarial drug to prevent Plasmodium vivax relapses. However, this drug can induce hemolysis in patients with glucose-6-phosphate dehydrogenase deficiency. Nanostructure formulations of primaquine loaded with D-galactose were used as a strategy to target the drug to the liver and decrease the hemolytic risks. Nanoemulsion (NE-Pq) and nanochitosan (NQ-Pq) formulations of primaquine diphosphate containing D-galactose were prepared and characterized by their physicochemistry properties. Pharmacokinetic and biodistribution studies were conducted using Swiss Webster mice. A single dose of 10 mg/kg of each nanoformulation or free primaquine solution was administered by gavage to the animals, which were killed at 0.5, 1, 2, 4, 8, and 24 hours. Blood samples and tissues were collected, processed, and analyzed by high-performance liquid chromatography. The nanoformulation showed sizes around 200 nm (NE-Pq) and 400 nm (NQ-Pq) and physicochemical stability for over 30 days. Free primaquine solution achieved higher primaquine Cmax in the liver than NE-Pq or NQ-Pq at 0.5 hours. However, the half-life and mean residence time (MRT) of primaquine in the liver were three times higher with the NQ-Pq formulation than with free primaquine, and the volume distribution was four times higher. Conversely, primaquine's half-life, MRT, and volume distribution in the plasma were lower for NQ-Pq than for free primaquine. NE-Pq, on the other hand, accumulated more in the lungs but not in the liver. Galactose-coated primaquine nanochitosan formulation showed increased drug targeting to the liver compared to free primaquine and may represent a promising strategy for a more efficient and safer radical cure for vivax malaria.
Assuntos
Antimaláricos , Quitosana , Galactose , Fígado , Primaquina , Primaquina/farmacocinética , Primaquina/química , Animais , Camundongos , Fígado/metabolismo , Fígado/efeitos dos fármacos , Galactose/química , Quitosana/química , Antimaláricos/farmacocinética , Nanopartículas/química , Distribuição Tecidual , Nanoestruturas/química , MasculinoRESUMO
Despite the criticism and reservations made about him still nowadays, Louis Pasteur may be considered one of the most important scientists of the last two centuries in public health, even if the work of the numerous scientists who preceded him have largely contributed to the successes he obtained without following too much to the rules of deontology and ethics currently in force in the world of research and medicine. He has definitively put down, by his experiments, the "theory of spontaneous generation" in force since antiquity, validated that of "germs or microbes", enacted the first rules of asepsis, while inspiring those of the antisepsis applied by Joseph Lister, and developed a certain number of vaccinations in veterinary and human medicine, including the anti-rabies, the one which made him famous all over the world. All this was not done without difficulty and Pasteur encountered for a large part of his life the misunderstanding of his contemporaries and the hostility of the medical world to which he did not belong. The authors comment in this text the movie The Story of Louis Pasteur by William Dieterle, filmed in 1936, based on the knowledge acquired since that date and doing the part of the real and the fiction.
Malgré les critiques et les réserves dont il est l'objet aujourd'hui, Louis Pasteur peut être considéré comme l'un des scientifiques les plus importants de ces deux derniers siècles en matière de santé publique, même si les apports des nombreux hommes de science qui l'ont précédé ont largement contribué aux succès qu'il obtint sans trop se soucier des règles de déontologie et d'éthique actuellement en vigueur dans le monde de la recherche et de la médecine. Il a mis définitivement à bas, par ses expériences, la « théorie de la génération spontanée ¼ en vigueur depuis l'Antiquité, validé celle « des germes ou microbes ¼, édicté les premières règles de l'asepsie tout en inspirant celles de l'antisepsie appliquée par Joseph Lister et mit au point un certain nombre de vaccinations en médecine vétérinaire puis humaine, notamment celle contre la rage, ce qui le rendit célèbre dans le monde entier. Tout cela ne s'est pas fait sans difficulté, et Pasteur s'est heurté pendant une grande partie de sa vie à l'incompréhension de ses contemporains et à l'hostilité du monde médical auquel il n'appartenait pas. Les auteurs commentent dans ce texte le film L'Histoire de Louis Pasteur de William Dieterle, tourné en 1936, en s'appuyant sur les connaissances acquises depuis cette date et en faisant la part du réel et de l'imaginé.
Assuntos
Filmes Cinematográficos , História do Século XIX , História do Século XX , Filmes Cinematográficos/história , Vacina Antirrábica/história , Pesquisa/história , Vacinas/históriaRESUMO
WHAT IS KNOWN AND OBJECTIVE: Malaria is a potentially severe disease, widespread in tropical and subtropical areas. Apart from parasite drug resistance, which receives the largest share of attention, several factors directly influence the response to antimalarial treatment such as incorrect doses, adverse drug events, lack of adherence to treatment, drug quality and drug-drug interactions. Pharmacotherapy follow-up can be used to monitor and improve the effectiveness of treatment, prevent drug-related problems and ensure patient safety. The aim of this study was to describe the results of the implementation of pharmacotherapy follow-up of patients with malaria seen at a reference centre for malaria diagnosis and treatment (CPD-Mal) located in the city of Rio de Janeiro, an area without malaria transmission. METHODS: A descriptive study was conducted from January 2009 to September 2013 at the Instituto Nacional de Infectologia Evandro Chagas (INI) of the Fundação Oswaldo Cruz (Fiocruz). All malaria patients enrolled in the study were treated according to the Brazilian Malaria Therapy Guidelines. Data collected during pharmacotherapy follow-up were recorded in a standardized form. The variables included were age, gender, comorbidities, antimalarials and concomitant medications used, adverse drug reactions (ADR), clinical and parasitological cure times, and treatment outcomes classified as success, recurrence (recrudescence or relapse); and lost to follow-up. The ADR were classified by severity (DAIDS-NIH), organ system affected (WHO-ART) and likelihood to be caused by drugs (Naranjo scale). RESULTS AND DISCUSSION: One hundred thirteen cases of malaria were included. Patients were aged between 13 and 66 years and the majority of them (75.2%) were male. Ninety-four ADR were observed, most classified as mild (85.1%), related to disorders of the gastrointestinal system (63.8%), such as nausea and vomiting, and assessed as "possibly" caused by the antimalarial drugs (91.5%). The majority of clinical (90.9%) and parasitological (87.1%) cure occurred less than 72 hours after treatment initiation. Pharmacotherapy follow-up of malaria treatment by surveillance activities is therefore important regarding information about treatment outcomes as well as patient safety, resulting in better patient care and reducing the chance of relapses. The results underscore its use as a tool for monitoring adherence and drug resistance outside an endemic area. WHAT IS NEW AND CONCLUSION: Pharmacotherapy follow-up should be considered a useful malaria surveillance tool that can be developed by reference centres for comprehensive health care assistance and monitoring of therapeutic resistance.
Assuntos
Antimaláricos/uso terapêutico , Malária/tratamento farmacológico , Adolescente , Adulto , Antimaláricos/efeitos adversos , Brasil , Criança , Resistência a Medicamentos , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/etiologia , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva , Medicina de Viagem/métodos , Resultado do Tratamento , Adulto JovemRESUMO
Several questions regarding the production and functioning of autoantibodies (AAb) during malaria infection remain open. Here we provide an overview of studies conducted in our laboratory that shed some light on the questions of whether antiphospholipid antibodies (aPL) and other AAb associated with autoimmune diseases (AID) can recognize Plasmodia antigens and exert anti-parasite activity; and whether anti-parasite phospholipid antibodies, produced in response to malaria, can inhibit phospholipid-induced inflammatory responses and protect against the pathogenesis of severe malaria. Our work showed that sera from patients with AID containing AAb against dsDNA, ssDNA, nuclear antigens (ANA), actin, cardiolipin (aCL) and erythrocyte membrane antigens recognize plasmodial antigens and can, similarly to monoclonal AAb of several specificities including phospholipid, inhibit the growth of P. falciparum in vitro. However, we did not detect a relationship between the presence of anti-glycosylphosphatidylinositol (GPI) antibodies in the serum and asymptomatic malaria infection, although we did register a relationship between these antibodies and parasitemia levels in infected individuals. Taken together, these results indicate that autoimmune responses mediated by AAb of different specificities, including phospholipid, may have anti-plasmodial activity and protect against malaria, although it is not clear whether anti-parasite phospholipid antibodies can mediate the same effect. The potential effect of anti-parasite phospholipid antibodies in malarious patients that are prone to the development of systemic lupus erythematosus or antiphospholipid syndrome, as well as the (possibly protective?) role of the (pathogenic) aPL on the malaria symptomatology and severity in these individuals, remain open questions.
Assuntos
Autoanticorpos/sangue , Autoimunidade , Malária/imunologia , Glicosilfosfatidilinositóis/imunologia , Humanos , Parasitemia/imunologia , Fosfolipídeos/imunologiaRESUMO
Aotus and Saimiri are non-human primate models recommended by the World Health Organization for experimental studies in malaria, especially for vaccine pre-clinical trials. However, research using these primates is hindered by the lack of specific reagents to evaluate immune responses to infection or vaccination. As a step toward developing molecular tools for cytokine expression studies in these species, primer pairs for 18 cytokine gene fragments were designed based on human DNA sequences and used to amplify the corresponding genes in Aotus infulatus and Saimiri sciureus genomic DNA samples. IFNγ, TNFα, LTA, IL2, IL3, IL4, IL5, IL6, IL10, IL12, IL13, CSF2 and TGFß2 gene fragments were amplified and sequenced. Primer pairs for IL8, IL17, IL18, IL27 and MIF failed to generate amplification products. When compared to the available corresponding human and non-human primate sequences, most--except IL3 and IL4--showed identity degrees above 90%. Small variations in sequence can help to explain the failure to amplify certain genes or the amplification only at lower annealing temperatures as compared to human DNA samples for several primer pairs. The sequences made available provide the basis for designing molecular tools such as primers for real time PCR specific for A. infulatus and/or S. sciureus. The nucleotide sequences reported in this paper have been submitted to the GenBank nucleotide sequence database and have been assigned accession numbers DQ985386 to DQ985389, DQ989356 to DQ989369, FJ89020 to FJ89024, and FJ89029.
Assuntos
Citocinas/genética , Modelos Animais de Doenças , Malária/genética , Análise de Sequência de DNA , Animais , Aotidae , Sequência de Bases , Primers do DNA , Humanos , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , SaimiriRESUMO
Antibody and T-cell reactivities to Plasmodium vivax merozoite surface protein 9 (PvMSP9) were evaluated in a cross-sectional study of individuals naturally exposed to malaria infections living in Ribeirinha, a native riverine community and in Colina, a transmigrant community, Rondonia, Brazil. The antibody responses to PvMSP9-RIRIIand PvMSP9-Nt domains in Ribeirinha were higher compared with Colina and correlated with age and time of malaria exposure. IgG2 was most prevalent for PvMSP9-RII in both communities, and IgG1 was the predominant isotype for PvMSP9-Nt and PvMSP9-RIRII in Ribeirinha. IFN-gamma and IL-4 predominated in Ribeirinha, while IFN-gamma predominated in Colina. Variation in exposure to P. vivax likely accounts for the differences observed in cytokine and antibody levels between the two populations studied.
Assuntos
Anticorpos Antiprotozoários/imunologia , Malária Vivax/imunologia , Proteínas de Membrana/imunologia , Plasmodium vivax/imunologia , Proteínas de Protozoários/imunologia , Adulto , Animais , Anticorpos Antiprotozoários/sangue , Formação de Anticorpos/imunologia , Brasil/epidemiologia , Estudos de Coortes , Estudos Transversais , Epitopos de Linfócito T/imunologia , Feminino , Humanos , Imunidade Ativa , Imunidade Celular , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Interferon gama/sangue , Interferon gama/imunologia , Interleucina-4/sangue , Interleucina-4/imunologia , Malária Vivax/epidemiologia , Masculino , Pessoa de Meia-Idade , Prevalência , Proteínas Recombinantes/imunologia , Adulto JovemRESUMO
Malaria was a nationwide problem in Brazil in the 1940's. However during the late fifties a national and successful campaign gained strength in the country decreasing malaria to its lowest level by 1960, when only 36,9 thousand cases were registered. Although the Malaria Eradication Program of the Ministry of Health in Brazil succeeded by the late 60's in freeing the majority of the country from malaria transmission, it was unable to contain the rapid spread of the disease in the Amazon Basin. In the 1970's the Amazon region witnessed a huge transformation. Colonization programs sponsored by the government, mining exploration, massive migration and the construction of roads and dams brought a new reality for which the area was not prepared. The last data available show that in 2007, the Amazon registered around 450 thousand cases, 99.9% of the national cases. P. vivax has been reported as representing around 80% of all malaria cases. P. vivax is thought to cause little mortality but like P. falciparum, P. vivax accounts for vast amounts of morbidity and for huge burdens on the prosperity of endemic communities. However, in the last few years a pattern of unusual clinical complications with fatal cases associated with it have been reported in Brazil and is a matter of tremendous concern in the Brazilian community of malariologists. In addition, the emergence of P. vivax strains resistant to chloroquine and primaquine in some reports needs to be further investigated. In contrast, asymptomatic infections by P. falciparum and P. vivax were detected in epidemiological studies in the states of Rondonia and Amazonas. Seropidemiological studies investigating the type of immune responses elicited in naturally exposed populations to several malaria vaccine candidates in Brazilian populations have also been providing important information on whether immune responses specific to those antigens are generated in natural infections and their immunogenic potential as vaccine candidates. In fact ultimate test of a malaria vaccine will be determined in field trials under natural conditions of parasite exposure.
Assuntos
Imunidade Inata , Malária Vivax/diagnóstico , Malária Vivax/epidemiologia , Animais , Anticorpos Antiprotozoários/sangue , Antimaláricos , Brasil/epidemiologia , Cloroquina , Resistência a Medicamentos , Humanos , Malária Vivax/imunologia , Plasmodium vivax/imunologia , PrimaquinaRESUMO
The immunogenicity and protective efficacy of various antigen-adjuvant formulations derived either from the merozoite-surface protein-3 (MSP-3) or the glutamate-rich protein (GLURP) of Plasmodium falciparum were evaluated in Saimiri sciureus monkeys. These proteins were selected for immunogenicity studies based primarily on their capacity of inducing an antibody-dependent cellular inhibition effect on parasite growth. Some of the S. sciureus monkeys immunized with MSP-3(212-380)-AS02 or GLURP(27-500)-alum were able to fully or partially control parasitaemia upon an experimental P. falciparum [Falciparum Uganda Palo Alto (FUP-SP) strain] blood-stage infection, and this protection was related to the prechallenge antibody titres induced. The data are indicative that MSP-3 and GLURP can induce protective immunity against an experimental P. falciparum infection using adjuvants that are acceptable for human use and this should trigger further studies with those new antigens.
Assuntos
Anticorpos/sangue , Antígenos de Protozoários/farmacologia , Vacinas Antimaláricas/farmacologia , Malária Falciparum/prevenção & controle , Plasmodium falciparum/imunologia , Proteínas de Protozoários/farmacologia , Animais , Anticorpos/imunologia , Antígenos de Protozoários/administração & dosagem , Antígenos de Protozoários/imunologia , Imunofluorescência , Memória Imunológica/efeitos dos fármacos , Memória Imunológica/imunologia , Vacinas Antimaláricas/administração & dosagem , Vacinas Antimaláricas/imunologia , Peptídeos/administração & dosagem , Peptídeos/imunologia , Peptídeos/farmacologia , Proteínas de Protozoários/administração & dosagem , Proteínas de Protozoários/imunologia , SaimiriRESUMO
The genetic polymorphism of the surface merozoite protein 2 (MSP-2) was evaluated in Plasmodium falciparum isolates from individuals with uncomplicated malaria living in a Brazilian endemic area of Peixoto de Azevedo. The frequency of MSP-2 alleles and the survival of genetically different populations clones in 104 isolates were verified by Southern blot and SSCP-PCR. Single and mixed infections were observed in similar frequencies and the rate of detection of FC27 and 3D7 allelic families was equivalent. Eight alleles were identified and among them, the sequence polymorphism was mainly attributed to variations in the repetitive region. Interestingly, in three alleles nucleotide polymorphism was identical to that detected in a previous study, conducted in 1992, in a near Brazilian endemic area. This finding demonstrated the genetic similarity between two isolate groups, besides the certain temporal stability in the allelic patterns. The implications of these data for studies on the genetic diversity are also discussed.
Assuntos
Antígenos de Protozoários/genética , Doenças Endêmicas , Variação Genética , Malária Falciparum/epidemiologia , Plasmodium falciparum/isolamento & purificação , Proteínas de Protozoários/genética , Alelos , Sequência de Aminoácidos , Animais , Southern Blotting , Brasil/epidemiologia , Frequência do Gene , Genes de Protozoários , Humanos , Malária Falciparum/parasitologia , Dados de Sequência Molecular , Plasmodium falciparum/genética , Reação em Cadeia da Polimerase , Polimorfismo Genético , Polimorfismo Conformacional de Fita Simples , Alinhamento de Sequência , Análise de Sequência de DNARESUMO
More than 30 years after the first report of successful vaccination against malaria using radiation-attenuated sporozoites, an effective malaria vaccine is not yet available. However, field and experimental data indicate that it can be developed. An astonishing amount of data has accumulated concerning parasite biology, host-parasite interactions, immunity and escape mechanisms, targets and modulators of immune responses. Nevertheless, so far this knowledge has not been enough to make us understand how to properly manipulate the whole system to build an effective vaccine. In this article, we describe candidate antigens, mechanisms, targets and trials performed with potential malaria vaccines and discuss the approaches, in vivo and in vitro models, constraints and how technologies such as DNA vaccination, genomics/proteomics and reverse immunogenetics are providing exciting results and opening new doors to make malaria vaccine a reality.