Merozoites Obtained through a Simpler Method Do Not Survive in Classically Activated Macrophages.

Malaria is caused by apicomplexan parasites of the genus. is an excellent animal model for the study of human malaria caused by . Merozoites invade erythrocytes but are also found in other host cells including macrophages from the spleen and liver.

Development of new dinuclear Fe(III) coordination compounds with nanomolar antitrypanosomal activity.

Chagas disease is a neglected tropical disease caused by the protozoan pathogen . The disease is a major public health problem affecting about 6 to 7 million people worldwide, mostly in Latin America. The available therapy for this disease is based on two drugs, nifurtimox and benznidazole, which exhibit severe side effects, including resistance, severe cytotoxicity, variable efficacy and inefficiency in the chronic phase.

Inhibition of nitric oxide production of activated mice peritoneal macrophages is independent of the Toxoplasma gondii strain.

Background: Toxoplasma gondii causes toxoplasmosis and is controlled by activated macrophages. However, infection of macrophages by tachyzoites induces TGF-β signaling (TGF-s) inhibiting nitric oxide (NO) production. NO inhibition may be a general escape mechanism of distinct T.

Apoptotic mimicry as a strategy for the establishment of parasitic infections: parasite- and host-derived phosphatidylserine as key molecule.

The establishment of parasitic infection is dependent on the development of efficient strategies to evade the host defense mechanisms. Phosphatidylserine (PS) molecules are pivotal for apoptotic cell recognition and clearance by professional phagocytes. Moreover, PS receptors are able to trigger anti-inflammatory and immunosuppressive responses by phagocytes, either by coupled enzymes or through the induction of regulatory cytokine secretion.

CD4 T Cell-Dependent Macrophage Activation Modulates Sustained PS Exposure on Intracellular Amastigotes of .

amastigotes can make use of surface-exposed phosphatidylserine (PS) molecules to promote infection and non-classical activation of macrophages (MΦ), leading to uncontrolled intracellular proliferation of the parasites. This mechanism was quoted as apoptotic mimicry. Moreover, the amount of PS molecules exposed on the surface of amastigotes correlates with the susceptibility of the host.

Anatomopathological changes, quantification and distribution of spp. in regions of the proventriculus and ventriculus of naturally- and experimentally-infected ostriches.

Nematodes of the genus parasitize ostriches, causing high mortality rates. These nematodes are found in the proventriculus and ventriculus of ostriches, but little is known about their distribution and the possible anatomopathological changes they cause in the various regions of these organs. This paper describes the distribution and quantification of and pathological changes found in regions of the proventriculus and ventriculus of ostriches with high and low levels of both natural and experimental infection.

Alterations in the Mitochondrial Physiology of Biomphalaria glabrata (Mollusca: Gastropoda) After Experimental Infection by Angiostrongylus cantonensis (Nematoda: Metastrongylidae).

Background: Angiostrongylus cantonensis is a metastrongylid nematode that has a heteroxenous cycle, where snails act as intermediate hosts and the rodents Rattus rattus and Rattus novergicus are the definitive hosts. However, humans may act as accidental hosts presenting an atypical form of parasitism. This fact has motivated research to better understand systems of relationships involving A.

Novel organic salts based on quinoline derivatives: The in vitro activity trigger apoptosis inhibiting autophagy in Leishmania spp.

Leishmaniases are infectious diseases, caused by protozoa of the Leishmania genus. These drugs present high toxicity, long-term administration, many adverse effects and are expensive, besides the identification of resistant parasites. In this work, the antileishmanial activity of quinoline derivative salts (QDS) was evaluated, as well as the toxicity on mammalian cells and the mechanism of action of the most promising compound.

Identification of IgE-binding peptide and critical amino acids of Jatropha curcas allergen involved in allergenic response.

Increasing energy demand has spurred interest in the use of biofuels. Jatropha curcas (physic nut), an inedible oilseed, is a potential source of bioenergy. The seeds, however, contain allergens such as Jat c 1, a 2S albumin that can induce hypersensitivity reactions in humans and result in allergic diseases.

Further evidence that naphthoquinone inhibits Toxoplasma gondii growth in vitro.

Toxoplasmosis is a widely disseminated disease caused by Toxoplasma gondii, an intracellular protozoan parasite. Standard treatment causes many side effects, such as depletion of bone marrow cells, skin rashes and gastrointestinal implications. Therefore, it is necessary to find chemotherapeutic alternatives for the treatment of this disease.

Experimental infection with the Toxoplasma gondii ME-49 strain in the Brazilian BR-1 mini pig is a suitable animal model for human toxoplasmosis.

Toxoplasma gondii causes toxoplasmosis, a worldwide disease. Experimentation with pigs is necessary for the development of new therapeutic approaches to human diseases. BR-1 mini pigs were intramuscularly infected with T.

Toxoplasma gondii oral infection induces intestinal inflammation and retinochoroiditis in mice genetically selected for immune oral tolerance resistance.

Toxoplasmosis is a worldwide disease with most of the infections originating through the oral route and generates various pathological manifestations, ranging from meningoencephalitis to retinochoroiditis and inflammatory bowel disease. Animal models for these pathologies are scarce and have limitations. We evaluated the outcome of Toxoplasma gondii oral infection with 50 or 100 cysts of the ME-49 strain in two lines of mice with extreme phenotypes of susceptibility (TS) or resistance (TR) to immune oral tolerance.

Culture of mouse peritoneal macrophages with mouse serum induces lipid bodies that associate with the parasitophorous vacuole and decrease their microbicidal capacity against Toxoplasma gondii.

Lipid bodies [lipid droplets (LBs)] are lipid-rich organelles involved in lipid metabolism, signalling and inflammation. Recent findings suggest a role for LBs in host response to infection; however, the potential functions of this organelle in Toxoplasma gondii infection and how it alters macrophage microbicidal capacity during infection are not well understood. Here, we investigated the role of host LBs in T.

Toxoplasma gondii infection of activated J774-A1 macrophages causes inducible nitric oxide synthase degradation by the proteasome pathway.

Classically activated macrophages produce nitric oxide (NO), which is a potent microbicidal agent. NO production is catalyzed by inducible nitric oxide synthase (iNOS), which uses arginine as substrate producing NO and citruline. However, it has been demonstrated that NO production is inhibited after macrophage infection of Toxoplasma gondii, the agent of toxoplasmosis, due to iNOS degradation.

Population dynamics of Libyostrongylus dentatus and L. douglassii of ostriches raised in the Northern Rio de Janeiro State, Brazil.

Libyostrongylus genus contains three species of gastrointestinal nematodes that infect ostriches. Of these, only Libyostrongylus douglassii has been implicated in diseases and lower productivity. A morphological diagnosis method allowing the discrimination of infective larvae of L.

Chickens treated with a nitric oxide inhibitor became more resistant to Plasmodium gallinaceum infection due to reduced anemia, thrombocytopenia and inflammation.

Malaria is a serious infectious disease caused by parasites of the Plasmodium genus that affect different vertebrate hosts. Severe malaria leads to host death and involves different pathophysiological phenomena such as anemia, thrombocytopenia and inflammation. Nitric oxide (NO) is an important effector molecule in this disease, but little is known about its role in avian malaria models.

New insight into the morphology of Eurytrema coelomaticum (Trematoda, Dicrocoeliidae) cercariae by light, scanning, and transmission electron microscopies.

Eurytrema coelomaticum is a digenetic trematode that parasitizes the pancreatic ducts of ruminants. In the present study, the morphology of the cercariae was analyzed using light, scanning, and transmission electron microscopies. The size of the larvae was larger than that reported in the literature.

Efficacy of albendazole and moxidectin and resistance to ivermectin against Libyostrongylus douglassii and Libyostrongylus dentatus in ostriches.

Anthelmintic resistance has emerged globally as a problem amongst nematode of livestock and has been particularly well documented in equine and small ruminants. There are no studies regarding the efficacy of anthelmintics against the hematophagous nematodes in ostriches, Libyostrongylus dentatus; and just a few on L. douglassii.

A new type of pterocarpanquinone that affects Toxoplasma gondii tachyzoites in vitro.

Toxoplasma gondii, the agent of Toxoplasmosis, is an obligate intracellular protozoan able to infect a wide range of vertebrate cells, including nonprofessional and professional phagocytes. Therefore, drugs must have intracellular activities in order to control this parasite. The most common therapy for Toxoplasmosis is the combination of sulfadiazine and pyrimethamine.

Phosphatidylserine exposure by Toxoplasma gondii is fundamental to balance the immune response granting survival of the parasite and of the host.

Phosphatidylserine (PS) exposure on the cell surface indicates apoptosis, but has also been related to evasion mechanisms of parasites, a concept known as apoptotic mimicry. Toxoplasma gondii mimics apoptotic cells by exposing PS, inducing secretion of TGF-beta1 by infected activated macrophages leading to degradation of inducible nitric oxide (NO) synthase, NO production inhibition and consequently persisting in these cells. Here PS⁺ and PS⁻ subpopulation of tachyzoites were separated and the entrance mechanism, growth and NO inhibition in murine macrophages, and mice survival and pathology were analyzed.

Mixed infection with Libyostrongylus dentatus and Libyostrongylus douglassii induces a heterophilic inflammatory infiltrate in the proventriculus of ostriches.

Libyostrongylus dentatus and Libyostrongylus douglassii are haematophagous nematodes found in the proventriculus and the ventriculus of ostriches. Pathological damage leading to bird death has been attributed to L. douglassii.