Margarida Maria de Lima Pompeu

In vitro and in vivo Leishmanicidal activity of 2‐hydroxy‐3‐(3‐methyl‐2‐butenyl)‐1,4‐naphthoquinone (lapachol)

This study aims to evaluate the in vitro and in vivo leishmanicidal activity of lapachol, a naphthoquinone found in the seeds and heartwood of certain tropical plants, and to compare its efficacy with a reference drug, sodium stibogluconate (Pentostam®). These compounds (0.0125–4.0 mg/mL) were evaluated in vitro against intracellular amastigotes of Leishmania (Viannia) braziliensis (LVb), then tested in an animal model (hamster) to try to reproduce the leishmanicidal activity. In vitro, lapachol exhibited an anti‐amastigote effect, whereas in vivo it did not prevent the development of LVb‐induced lesions at an oral dose of 300 mg/kg/day for 42 days. Pentostam® demonstrated a significant anti‐amastigote effect in vitro for LVb and apparent clinical cure in vivo (60 mg/kg/day). However, it could not completely eradicate parasites from the tissues of infected animals. The observation that lapachol exerts leishmanicidal activity in vitro without offering significant protection against LVb‐infected lesions in hamsters suggests that lapachol in vivo might possibly inhibit the microbicidal functioning of macrophages. Alternatively, it might be transformed into an inactive metabolite(s) or neutralized, losing its leishmanicidal activity. It is also possible that an optimal and sustained plasma level of the drug could not be achieved at the dose used in this study. Copyright

Controle do calazar canino: comparação dos resultados de um programa de eliminação rápida de cães sororreagentes por ensaio imuno-enzimático com outro de eliminação tardia de cães sororreagentes por teste de imunofluorescência indireta de eluato de papel filtro

The kala-azar control program, adopted by the Fundação Nacional de SaúdeFNS (National Health Foundation) has not been able to reduce to an acceptable level the incidence of human cases. The diagnostic method utilized is a blood eluate immunofluorescence. A dogs diagnosed as infected is eliminated a mean of eighty days after the blood collection. The low sensitivity of the test used and the continuing residence of the infected dog in the region due to the elimination delay may be critical in the lack of success of this program. In this study, the FNS standard canine control method is compared to a strategy based on ELISA identification of infected dog and elimination within 7 days. In both study areas the canine seroprevalence was noted ten months before and ten months after the intervention. In the routine FNS area a 9% decrease in seroprevalence was noted, compared to statistically significant greater 27%, reduction (p = 0.0015) in the ELISA intervention area. Key-words: Visceral leishmaniasis. Kala-azar. Epidemiologic control. Reservoir. Canine kala-azar control: aftermath comparison of a fast deletion program of serum-reactive dogs by immuno-enzimatic essay with another of late deletion program of serum-reactive dogs by indirect immunofluorescence of filter paper eluate Marcus Davis Machado Braga, Ivo Castelo Branco Coêlho, Margarida Maria Lima Pompeu, Thomas G. Evans, Isabel Tavares MacAullife, Maria Jania Teixeira e José Wellington de Oliveira Lima Revista da Sociedade Brasileira de Medicina Tropical 31:419-424, set-out, 1998. 420 No Brasil a leishmaniose visceral é causada pela Leishmania chagasi 6 22, e transmitida ao homem através da picada de um psicodídeo, a Lutzomya longipalpis 6 9 13 14. Duas espécies de mamíferos já foram incriminadas como reservatório deste parasita, uma silvestre, a raposa12, e outra doméstica, o cão1 2 3 10 11. A leishmaniose visceral humana e canina são endêmicas no Brasil, principalmente no Nordeste6 18. Nesta região, e mais especificamente, no Estado do Ceará, em humanos a doença apresenta uma prevalência de 10,08/100.000 habitantes17. O Ministério da Saúde do Brasil, desde o início da década de 60, através da então Superintendência de Campanhas de Saúde Pública (SUCAM), e mais recentemente, da Fundação Nacional de Saúde (FNS), vem desenvolvendo atividades de controle da infecção canina, em vários estados da Federação, incluindo o Ceará2 20. Este controle inclui medidas para diminuir a densidade populacional do vetor, e a identificação e eliminação de cães infectados6 20 22. Ao longo destes anos, em função da necessidade de se utilizar técnicas cada vez mais sensíveis, diferentes métodos de identificação de cães infectados têm sido propostos. Inicialmente, foi utilizado o exame parasitológico da pele e/ou vísceras3, outra técnica utilizada foi a detecção de anticorpos antileishmania, por reação de fixação do complemento8. A partir de 1982, vêm-se usando a técnica de imunofluorescência realizada em eluato de sangue colhido em papel filtro6 22. Embora a introdução da imunofluorescência ainda represente um grande avanço, esta técnica, quando realizada em eluato de papel filtro, apresenta uma sensibilidade muito baixa, quando comparada com ELISA realizada no soro4 15. Após 5 anos de atividades de controle do reservatório canino, utilizando a imunofluorescência no eluato para detectar cães infectados, observou-se que é possível reduzir a prevalência da infecção no cão até certo limite, em torno de 0,5 a 1%. Esta redução, no entanto, não se acompanha necessariamente de uma interrupção da transmissão ao homem21. Acreditamos que, entre outros fatores, a baixa sensibilidade do teste de IFI no eluato, e o tempo decorrido entre a coleta de sangue e a eliminação do cão infectado, sejam responsáveis pela permanência de cães infectados e pela manutenção da transmissão da infecção. Neste trabalho, avalia-se o impacto que a eliminação precoce de cães infectados, detectados por uma técnica de diagnóstico mais sensível, possa ter na prevalência da infecção do cão pela L. chagasi, comparando esta estratégia com aquela adotada pelo programa de controle da leishmaniose visceral, na qual cães infectados são detectados pela IFI no eluato e eliminados, em média, 80 dias depois.The kala-azar control program, adopted by the Fundacao Nacional de Saude- FNS (National Health Foundation) has not been able to reduce to an acceptable level the incidence of human cases. The diagnostic method utilized is a blood eluate immunofluorescence. A dogs diagnosed as infected is eliminated a mean of eighty days after the blood collection. The low sensitivity of the test used and the continuing residence of the infected dog in the region due to the elimination delay may be critical in the lack of success of this program. In this study, the FNS standard canine control method is compared to a strategy based on ELISA identification of infected dog and elimination within 7 days. In both study areas the canine seroprevalence was noted ten months before and ten months after the intervention. In the routine FNS area a 9% decrease in seroprevalence was noted, compared to statistically significant greater 27%, reduction (p = 0.0015) in the ELISA intervention area.The kala-azar control program, adopted by the Fundação Nacional de Saúde-FNS (National Health Foundation) has not been able to reduce to an acceptable level the incidence of human cases. The diagnostic method utilized is a blood eluate immunofluorescence. A dogs diagnosed as infected is eliminated a mean of eighty days after the blood collection. The low sensitivity of the test used and the continuing residence of the infected dog in the region due to the elimination delay may be critical in the lack of success of this program. In this study, the FNS standard canine control method is compared to a strategy based on ELISA identification of infected dog and elimination within 7 days. In both study areas the canine seroprevalence was noted ten months before and ten months after the intervention. In the routine FNS area a 9% decrease in seroprevalence was noted, compared to statistically significant greater 27%, reduction (p = 0.0015) in the ELISA intervention area.

Differences in gamma interferon production in vitro predict the pace of the in vivo response to Leishmania amazonensis in healthy volunteers

ABSTRACT The initial encounter of Leishmania cells and cells from the immune system is fundamentally important in the outcome of infection and determines disease development or resistance. We evaluated the anti-Leishmania amazonensis response of naive volunteers by using an in vitro priming (IVP) system and comparing the responses following in vivo vaccination against the same parasite. In vitro stimulation allowed us to distinguish two groups of individuals, those who produced small amounts of gamma interferon (IFN-γ) (n = 16) (low producers) and those who produced large amounts of this cytokine (n = 16) (high producers). IFN-γ production was proportional to tumor necrosis factor alpha and interleukin 10 (IL-10) levels but did not correlate with IL-5 production. Volunteers who produced small amounts of IFN-γ in vitro remained low producers 40 days after vaccination, whereas high producers exhibited increased IFN-γ production. However, 6 months after vaccination, all individuals tested produced similarly high levels of IFN-γ upon stimulation of their peripheral blood mononuclear cells with Leishmania promastigotes, indicating that low in vitro producers respond slowly in vivo to vaccination. In high IFN-γ producers there was an increased frequency of activated CD8+ T cells both in vitro and in vivo compared to the frequency in low producers, and such cells were positive for IFN-γ as determined by intracellular staining. Such findings suggest that IVP responses can be used to predict the pace of postvaccination responses of test volunteers. Although all vaccinated individuals eventually have a potent anti-Leishmania cell-mediated immunity (CMI) response, a delay in mounting the CMI response may influence resistance against leishmaniasis.

Protective Effect of an Extract from Ascaris suum in Experimental Arthritis Models

ABSTRACT We investigated the effect of an extract from a helminth (Ascaris suum) in zymosan-induced arthritis (ZYA) or collagen-induced arthritis (CIA). Rats and mice, respectively, received 1 mg and 0.1 mg zymosan intra-articularly (i.a.). Test groups received an A. suum extract either per os (p.o.) or intraperitoneally (i.p.) 30 min prior to i.a. zymosan. Controls received saline. Hypernociception was measured using the articular incapacitation test. Cell influx, nitrite, and cytokine levels were assessed in joint exudates. The synovia and distal femoral extremities were used for histopathology. Cartilage damage was assessed through determining glycosaminoglycan (GAG) content. DBA/1J mice were subjected to CIA. The test group received A. suum extract i.p. 1 day after CIA became clinically detectable. Clinical severity and hypernociception were assessed daily. Neutrophil influx was determined using myeloperoxidase activity. The A. suum extract, either i.p. or p.o., significantly and dose-dependently inhibited cell influx and hypernociception in ZYA in addition to reducing GAG loss and ameliorating synovitis. The A. suum extract reduced i.a. levels of NO, interleukin-1β (IL-1β), and IL-10 but not tumor necrosis factor alpha (TNF-α) in rats subjected to ZYA while reducing i.a. IL-10, but not IL-1β or TNF-α, levels in mice. Clinically, mice subjected to CIA treated with the A. suum extract had less severe arthritis. Hypernociception, myeloperoxidase activity, and synovitis severity were significantly reduced. These data show that a helminth extract given p.o. protects from arthritis severity in two classical arthritis models. This A. suum effect is species independent and functions orally and parenterally. The results show clinical and structural benefits when A. suum extract is given either prophylactically or therapeutically.

Distinct Leishmania braziliensis Isolates Induce Different Paces of Chemokine Expression Patterns

ABSTRACT Inflammatory events during Leishmania braziliensis infection in mice were investigated. Large lesions were directly correlated with the inflammatory reaction but not with parasite burden. Different L. braziliensis strains induce different paces of chemokine expression patterns, leading to diverse cell recruitment and differential inflammatory responses.

High-Dose Oral Fluconazole Therapy Effective for Cutaneous Leishmaniasis Due to Leishmania (Vianna) braziliensis

We report for the first time the successful use of fluconazole to treat cutaneous leishmaniasis due to Leishmania braziliensis. We used escalating doses from 5 to 8 mg/kg per day. At a dose of 5 mg/kg per day, 75% patients were cured, and at 8 mg/kg per day, the cure rate was 100%. Fluconazole was well tolerated.

1,8‐Cineole protects against liver failure in an in‐vivo murine model of endotoxemic shock

The effects of 1,8‐cineole on d‐galactosamine/lipopolysaccharide (GalN/LPS)‐induced shock model of liver injury was investigated in mice. The co‐administration of GalN (700 mg kg−1, i.p.) and LPS (5 μg kg−1, i.p.) greatly elevated serum concentrations of tumour necrosis factor‐α (TNF‐α), alanine aminotransferase and aspartate aminotransferase, and induced massive hepatic necrosis and lethality in 100% of control mice. Pretreatment with 1,8‐cineole (400 mg kg−1, p.o.) and dexamethasone (1 mg kg−1, s.c.),60 min before GalN/LPS, offered complete protection (100%) against the lethal shock and acute elevation in serum TNF‐α and serum transaminases. Hepatic necrosis induced by GalN/LPS was also greatly reduced by both 1,8‐cineole and dexamethasone treatment. The results indicate that 1,8‐cineole protects mice against GalN/LPS‐induced liver injury through the inhibition of TNF‐α production, and suggest that 1,8‐cineole may be a promising agent to combat septic‐shock‐associated pathologies.

In vivo protective effect of the lectin from Canavalia brasiliensis on BALB/c mice infected by Leishmania amazonensis

In vivo administration of Canavalia brasiliensis lectin (at the time of infection, or maintained throughout the infection) reduced the lesions of highly susceptible BALB/c mice infected by Leishmania amazonensis. At the doses used C. brasiliensis lectin (ConBr) does not interfere with penetration or fate of Leishmania in the macrophages in vitro. Since Interferon-gamma (IFN-gamma) is the major macrophage activating factor, and considered a critical element in the successful immune response against leishmaniasis, we explored its participation in this phenomenon. ConBr either in vivo or in vitro induced IFN-gamma production in normal or in leishmania-infected BALB/c mice. However we were unable to change the course of disease by in vivo IFN-gamma administration (although IFN-gamma preparations were effective in inducing a leishmanicidal effect in vitro on L. amazonensis-infected peritoneal macrophages). Additionally, IFN-gamma neutralization with anti-IFN-gamma monoclonal antibody did not alter the protection conferred by ConBr administration. These data show that lectin administration in vivo is protective in the otherwise unchecked L. amazonensis infection of BALB/c mice, and suggest that such effect is not mediated by IFN-gamma.

Postmortem Findings for 7 Neonates with Congenital Zika Virus Infection

Postmortem examination of 7 neonates with congenital Zika virus infection in Brazil revealed microcephaly, ventriculomegaly, dystrophic calcifications, and severe cortical neuronal depletion in all and arthrogryposis in 6. Other findings were leptomeningeal and brain parenchymal inflammation and pulmonary hypoplasia and lymphocytic infiltration in liver and lungs. Findings confirmed virus neurotropism and multiple organ infection.

Hantavirus infection in suspected dengue cases from State of Ceará, Brazil

1. Curso de Medicina, Universidade de Fortaleza, Fortaleza, CE. 2. Departamento de Patologia e Medicina Legal, Universidade Federal do Ceara, Fortaleza, CE. 3. Centro de Pesquisa em Virologia, Faculdade de Medicina, Universidade de Sao Paulo, Ribeirao Preto, SP. 4. Setor de Virologia, Laboratorio Central de Saude Publica do Estado do Ceara, Fortaleza, CE. 5. Nucleo de Vigilância Epidemiologica, Secretaria Estadual de Saude do Estado do Ceara, Fortaleza, CE. 6. Departamento de Saude Publica, Universidade Federal do Ceara, Fortaleza, CE.