Evidência da ação antiparasitária da azitromicina na infecção experimental de camundongos pelo Plasmodium berghei / Experimental infection in mice by Plasmodium berghei: an evidence of antiparasitic action of azithromycin

Infections of Plasmodium berghei in mice was stopped by azithromycin which was administered orally in dosages of 100mg/kg, for 28 days. This antibiotic was given since the same day that the animals were infected. The outcome suggests the necessity of more investigations on this antiparasitic activity.

A azitromicina debelou a infecção experimental de camundongos pelo Plasmodium berghei quando administrada, pela via oral e durante 28 dias, na dose de 100mg/kg, iniciada no mesmo dia em que os animais foram infectados. Mediante uso de 10mg/kg houve insucesso. Os resultados obtidos suscitam investigações complementares sobre a referida atividade antiparasitária desse medicamento.

[Evaluation of antiparasitic activity of allopurinol, against Trypanosoma cruzi, in experimental system using infected triatomines]. / Avaliação da atividade antiparasitária do alopurinol, referente ao Trypanosoma cruzi, em sistema experimental que utiliza triatomíneos infectados.

The antiparasitic activity of allopurinol, against Trypanosoma cruzi, was evaluated by a procedure using infected triatomines. This methodology indicated that the drug was unable to eliminate the protozoa in the digestive tract of the insects. Therefore, further knowledge to improve our understanding of allopurinol in the context of the etiologic treatment of infection by T. cruzi was not acquired. Despite this finding the drug continues to be used, even though its performance appears to be full of divergences and contradictions.

[The evaluation of the efficacy of azithromycin and pyrimethamine used alone or in combination in the treatment of an experimental infection in mice by Toxoplasma gondii]. / Avaliação da eficácia da azitromicina e da pirimetamina, usadas isolada ou associadamente, no tratamento de infecção experimental de camundongos pelo Toxoplasma gondii.

The efficacy of azithromycin and pyrimethamine in experimental infection of mice with Toxoplasma gondii was tested. Daily dosages of 200 mg/kg and 12.5 mg/kg, respectively, were given orally over a period of ten days. The medications were administered in combination or separately. The combined use of the drugs yielded better results, and a similar investigation using a cystogenic strain of the parasite will be conducted in a future study.

[Utility of gamma rays in prophylaxis of transmissible malaria by blood transfusion]. / Estudo sobre a eventual utilidade de raios gama na profilaxia da malária transmissível por transfusão de sangue.

This study was carried out to evaluate the fortuitons advantage of using gamma irradiation in the prophylaxis of transmissible malaria by blood transfusion, with mice as the experimental model. In the first step, when the infected blood with Plasmodium berghei was submitted to 2,500 rad and 5,000 rad, with or without metronidazol, there was no success, because the animals presented parasitaemia and died after inoculation of irradiated blood. However, there was partial success in the second step, when the infected blood received 10,000 and 15,000 rad, and was inoculated in mice, which showed infection, and presented a survival rate of 20% and 40%, respectively, with later negativation of blood infected by P. berghei.

Estudo sobre a eventual utilidade de raios gama na profilaxia da malária transmissível por transfusão de sangue / Utility of gamma rays in prophylaxis of transmissible malaria by blood transfusion

This study was carried out to evaluate the fortuitons advantage of using gamma irradiation in the prophylaxis of transmissible malaria by blood transfusion, with mice as the experimental model. In the first step, when the infected blood with Plasmodium berghei was submitted to 2,500 rad and 5,000 rad, with or without metronidazol, there was no success, because the animals presented parasitaemia and died after inoculation of irradiated blood. However, there was partial success in the second step, when the infected blood received 10,000 and 15,000 rad, and was inoculated in mice, which showed infection, and presented a survival rate of 20% and 40%, respectively, with later negativation of blood infected by P. berghei.

O estudo foi realizado com o objetivo de avaliar a eventual utilidade de raios gama na profilaxia da malária transmissível por transfusão de sangue, tendo sido, para isso, usados camundongos infectados pelo Plasmodium berghei. Na primeira fase, quando submetemos sangue deles retirado a 2.500 e 5.000rad, com associação ou não de metronidazol, não obtivemos sucesso, já que todos os animais antes sem a parasitose apresentaram parasitemia e morreram após inoculação do sangue irradiado. Porém, ocorreu êxito parcial na segunda fase, ao serem empregados 10.000 e 15.000rad, porquanto 20% e 40% dos roedores, respectivamente, embora tenham ficado infectados, sobreviveram, com posterior negativação quanto à presença do P. berghei.

Tratamento de ratos, experimentalmente infectados pelo Strongyloides venezuelensis, através da ivermectina administrada por via oral / The treatment of rats experimentally infected with Strongyloides venezuelensis by orally administered ivermectin

Em modelo experimental, baseado na infecção de ratos pelo Strongyloides venezuelensis, foi avaliada a atividade terapêutica de duas preparações de ivermectina, para usos veterinário e humano. Houve interesse em verificar a efetividade em relação a vermes adultos e formas larvárias. A administração dos fármacos ocorreu sempre por via oral e a posologia correspondeu à dose única de 0,2mg/kg. Considerados os vermes adultos e as formas larvárias, o produto para emprego veterinário propiciou eliminações expressas pelas porcentagens de 98,0% e 84,2%; quanto à outra preparação, as taxas situaram-se em 59,3% e 73,0%, respectivamente. O estudo revelou, então, utilidade do anti-helmíntico quando usada a via oral e, também, mostrou significativa ação sobre as formas larvárias, certamente valiosa quando vigente a modalidade disseminada da estrongiloidíase.

Strongyloides venezuelensis experimental infection in rats was treated by two different oral preparations of ivermectin, 0.2 mg/kg. One was a human formula used by WHO in the treatment of onchocerciasis; the other was a veterinary preparation. Adult worms and larvae were evaluated. The human formulation cleared both forms in 59.3% (adult worms) and 73.0% (larvae), whereas the veterinary one cleared 98.0% and 84.2%, respectively. The antilarval action is very useful when treating systemic strongyloidiasis.

[Oocysts of Cryptosporidium sp in feces: comparison of the modified Kinyoun and Heine methods]. / Pesquisa de oocistos de Cryptosporidium sp em fezes: comparação entre os métodos de Kinyoun modificado e de Heine.

The diagnosis of intestinal infection by Cryptosporidium sp is crucial today; with the progression of the AIDS epidemic, many cases of cryptosporidiosis have appeared in this setting and in other immunodeficiency diseases. We compared the advantages and disadvantages of Heine's method and modified Kinyoun's method in the following parameters: morphology of the parasite, quantitation of cysts, stability of the staining characteristics timewise on the slides and time spend at staining. All positive fecal smears were obtained from patients with AIDS. The sensitivity of these two techniques was the same. The choice should be made by the best aspects of each method. Heine's was better for quantitation of the cysts and was faster. Kinyoun's was better for conserving the stained smear.

[Casual influence of the stimulation of macrophage production by proteose-peptone, in the experimental infection of mice by Plasmodium berghei]. / Estudo sobre eventual influência do estímulo para produção de macrófagos, por meio da proteose-peptona, na infecção experimental de camundongos pelo Plasmodium berghei.

Proteose-peptone is a known powerful stimulator of macrophages. This stimulation was studied in an experimental malaria infection model, using Plasmodium berghei in mice. Parasitemia and mortality did not change in stimulated animals, and macrophage mobilization, contrary to other published papers, was not effective to increase either parasite levels in the blood or mortality.

Novo processo para triagem de medicamentos na infeccao experimental pelo Trypanosoma cruzi / New process for screening of drugs in experimental infection with Trypanosoma cruzi

E proposto processo para triagem da capacidade terapeutica de medicamentos na infeccao experimental pelo Trypanosoma cruzi. O metodo tem base no emprego de triatomineos parasitados que se alimentam, decorridos periodos diferentes para haver compatibilizacao com niveis sanguineos, em camundongos aos quais foi administrado o farmaco sob apreciacao; assim, o tubo digestivo do hemiptero participara como estrutura propicia a avaliacao. Em observacao inicial, ocorreu utilizacao do benzonidazol, que se mostrou apenas parcialmente ativo, pelo menos de acordo com a maneira de execucao do novo procedimento.

Tentativas de criacao de triatomineos em laboratorio por meio de alimentacao "in vitro" / Attempts for cultivation of triatominae in laboratory through \"in vitro\" feeding

Para simplificar a criacao de triatomineos em laboratorio, necessaria, por exemplo, a execucao do xenodiagnostico e em estudos de carater biologico, foi tentada alimentacao "in vitro", mediante emprego de sangue, citratado ou desfibrinado, de galinhas abatidas em matadouro avicola. Para avaliacao da eficacia desse proposito, observacoes de duas naturezas, com Triatoma infestans, tiveram lugar, atraves das seguintes medidas; a) analise do encadeamento de estadios nifais sucessivos e da exequibilidade de satisfatorios acasalamentos, oviposicao fertil e adequada reproducao; b) apreciacao da infectividade e da viabilidade do Trypanosoma cruzi nos insetos. Como conclusao, ficou evidente que, a despeito da facilitacao operacional, o intuito nao conduziu ao exito desejado, ja que o procedimento classico, usado como controle, mostrou-se sempre superior.