Publications by authors named "Aparecida D Malvezi"

Chagas' disease is a life-threatening condition caused by . Patients with chronic disease may develop gastrointestinal, neurological, or associated neuro-digestive dysfunctions. CNS invasion by can occur in the acute phase, and its presence in the brain and cerebrospinal fluid was reported.

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The aim of the study was to evaluate the effect of metabolic syndrome (MetS) on female Swiss mice subjected to severe polymicrobial sepsis induced by cecal ligation and puncture (CLP). MetS was induced in neonatal Swiss mice by subcutaneous injection of monosodium glutamate (MSG) at 4 mg/g body weight from day 1 to day 5 after birth, while animals in the control group (CTL) were treated with equimolar saline solution at the same volume and period. On the 75th day of life, the CLP model was used to induce severe polymicrobial sepsis.

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Article Synopsis
  • The study investigates how aspirin (ASA) can help prevent bone loss in mice suffering from metabolic syndrome (MetS) and periodontal disease (PD).
  • Newborn mice were induced with MetS and then exposed to PD, with half receiving daily aspirin treatment, while assessing various health and bone loss parameters.
  • Findings showed that while ASA reduced bone loss in non-MetS mice, MetS mice did not respond to the treatment, highlighting the complex interaction between MetS and PD.
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Background: Sepsis is a complex condition characterized by systemic host inflammation caused by an infection. Experimental and observational studies indicate that obesity, one of the components of metabolic syndrome (MetS), or aspirin (ASA) treatment could be associated with sepsis survival. However, the effects of ASA on septic mice with MetS-induced conditions have not been explored.

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Chagas disease (CD), caused by , is a neglected tropical disease prevalent in Latin America. Infected patients are treated to eliminate the parasite, reduce the cardiomyopathy risk, and interrupt the disease transmission cycle. The World Health Organization recognizes benznidazole (BZ) and nifurtimox as effective drugs for CD treatment.

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Trypomastigote forms of Trypanosoma cruzi, the causative agent of Chagas disease, shed extracellular vesicles (EVs) that promote the susceptibility of host cells to infection. During T. cruzi infection, the immune response of the host is important for controlling parasitism, which is necessary for survival.

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Aims: Sepsis is a potentially fatal systemic inflammatory response and its underlying pathophysiology is still poorly understood. Studies suggest that obesity, a component of metabolic syndrome (MS), is associated with sepsis survival. Therefore, this study focused on investigating the influence of MS on mortality and cardiovascular dysfunction induced by sublethal cecal ligation and puncture (SL-CLP).

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Article Synopsis
  • Chagas disease, caused by the parasite Trypanosoma cruzi, relies on the survival of the parasite within immune cells (macrophages), which are essential for controlling infection and host health.* -
  • The study utilized BALB/c mice to assess the impact of Concanavalin-A (Con-A) treatment on macrophage function and response to T. cruzi infection, measuring key immune responses such as cytokine release and parasitemia.* -
  • Results indicated that Con-A treatment enhances the immune response by promoting M1 macrophage polarization, leading to increased production of trypanocidal factors and improved survival rates in infected mice.*
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Chagas disease, caused by the protozoan , is one of the main causes of death due to cardiomyopathy and heart failure in Latin American countries. The treatment of Chagas disease is directed at eliminating the parasite, decreasing the probability of cardiomyopathy and disrupting the disease transmission cycle. Benznidazole (BZ) and nifurtimox (Nfx) are recognized as effective drugs for the treatment of Chagas disease by the World Health Organization, but both have high toxicity and limited efficacy, especially in the chronic disease phase.

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We evaluated the influence of metabolic syndrome (MS) on acute Trypanosoma cruzi infection. Obese Swiss mice, 70 days of age, were subjected to intraperitoneal infection with 5 × 10 trypomastigotes of the Y strain. Cardiovascular, oxidative, inflammatory, and metabolic parameters were evaluated in infected and non-infected mice.

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During the onset of infection, an effective immune response is necessary to control parasite replication and ensure host survival. Macrophages have a central role in innate immunity, acting as an important trypanocidal cell and triggering the adaptive immune response through antigen presentation and cytokine production. However, displays immune evasion mechanisms that allow infection and replication in macrophages, favoring its chronic persistence.

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Article Synopsis
  • Chagas disease, caused by a parasite and affecting around 7 million people primarily in Latin America, involves interactions between the parasite and immune cells like monocytes and dendritic cells.
  • Research using DC-enriched peripheral human blood mononuclear cell populations showed that selective COX-2 inhibitor celecoxib and adenilate cyclase inhibitor SQ 22,536 significantly reduced parasitic infection, unlike aspirin, which did not inhibit infection or nitric oxide production.
  • The study highlights the role of COX-2 and cAMP pathways in the invasion of immune cells by the parasite, suggesting these pathways could be potential targets for developing new treatments for Chagas disease.
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Cell invasion by Trypanosoma cruzi and its intracellular replication are essential for progression of the parasite life cycle and development of Chagas disease. Prostaglandin E2 (PGE) and other eicosanoids potently modulate host response and contribute to Chagas disease progression. In this study, we evaluated the effect of aspirin (ASA), a non-selective cyclooxygenase (COX) inhibitor on the T.

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Long-chain omega-3 polyunsaturated fatty acids (LC n-3 PUFA) are known to modulate a variety of immune cell functions. On occasion, this has led to diminished host resistance to certain viral and bacterial infections. Little is known about the impact of n-3 PUFA on host resistance to parasitic infection, however, based on results from a small study conducted more than two decades ago, we hypothesized that providing mice LC n-3 PUFA will diminish host resistance to Trypanosoma cruzi, the parasitic pathogen responsible for Chagas disease.

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Article Synopsis
  • Chagas disease, caused by the parasite Trypanosoma cruzi, is a significant health issue in Latin America, and the invasion and replication of this parasite in host cells are crucial for its life cycle.
  • Research indicates that host cyclooxygenase (COX) enzymes, particularly COX-1, play a role in T. cruzi invasion; using NSAIDs like aspirin and celecoxib can inhibit the infection when cardiac cells are pretreated.
  • The study finds that COX-1's involvement leads to increased production of nitric oxide (NO) and interleukin-1β, and decreased transforming growth factor β (TGF-β), highlighting potential new targets for treating Chagas disease.
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Article Synopsis
  • Trypanosoma cruzi is a protozoan parasite that causes Chagas disease, significantly impacting millions in Latin America, and its invasion and replication in host cells are crucial for the disease's progression.* -
  • Research indicates that the host's cyclooxygenase (COX) enzyme plays a role in T. cruzi infection, with aspirin inhibiting the parasite's invasion in macrophages and leading to increased levels of IL-1β and nitric oxide.* -
  • The study highlights the interaction between prostaglandins, nitrates, and lipoxins in regulating macrophage responses to T. cruzi, enhancing understanding of the inflammatory response and potential immune strategies against the infection.*
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Mice infected with Trypanosoma cruzi, the agent of Chagas disease, rapidly develop anemia and thrombocytopenia. These effects are partially promoted by the parasite trans-sialidase (TS), which is shed in the blood and depletes sialic acid from the platelets, inducing accelerated platelet clearance and causing thrombocytopenia during the acute phase of disease. Here, we demonstrate that oral immunization of C57BL/6 mice with Phytomonas serpens, a phytoflagellate parasite that shares common antigens with T.

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Trypanosoma cruzi, the causative agent of Chagas' disease (CD), is a substantial public health concern in Latin America. Laboratory mice inoculated with T. cruzi have served as important animal models of acute CD.

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Chagas' disease is accompanied by severe anemia and oxidative stress, which may contribute to mortality. In this study, we investigated the role of 5-lipoxygenase (5-LO) in the control of parasitism and anemia associated with oxidative damage of erythrocytes in experimental Trypanosoma cruzi infection. Wild-type C57BL/6, 129Sv mice treated or not with nordihydroguaiaretic acid (NDGA, 5-LO inhibitor), mice lacking the 5-LO enzyme gene (5-LO(-/-)) and inducible nitric oxide synthase gene (iNOS(-/-)) were infected with the Y strain of T.

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Prostaglandins are known to be produced by macrophages when challenged with Trypanosoma cruzi, the etiological agent of Chagas' disease. It is not known whether these lipid mediators play a role in oxidative stress in host defenses against this important protozoan parasite. In this study, we demonstrated that inducible cyclooxygenase-mediated prostaglandin production is a key chemical mediator in the control of parasite burden and erythrocyte oxidative stress during T.

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Trypanosoma cruzi infection in mice is associated with severe hematological changes, including anemia, which may contribute to mortality. TNF-alpha and nitric oxide (NO) play a critical role in establishing host resistance to this pathogen. We hypothesized that phagocyte-derived NO damages erythrocytes and contributes to the anemia observed during T.

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