Molecular test for screening malaria-infected blood donors to maximise recipient safety in Acre State, a Brazilian endemic area.

Background: Although blood transfusion is an essential therapeutic procedure, it can present risks, including transmitting infectious diseases, such as malaria. In Acre, the thick blood smear microscopic examination (TBS) is used to screen infected malaria blood donors. However, TBS has low sensitivity for detecting Plasmodium in situations of low parasitaemia, such as those presented by asymptomatic clinically healthy individuals.

A hypothesis to explain malaria-induced neurocognitive sequelae.

The development of malaria-induced neurocognitive and behavioral sequelae is not entirely understood. We hypothesize that liver dysfunction caused by Plasmodium infection is responsible for malaria-induced neurocognitive and behavioral sequelae. Our metabolic hypothesis not only explains neurocognitive sequelae after cerebral malaria (CM) but also after other severe, non-severe, and asymptomatic malaria infections.

Cell Death of Blood Stages Occurs in Absence of Classical Apoptotic Events and Induces Eryptosis of Parasitized Host Cells.

Elucidation of pathways regulating parasite cell death is believed to contribute to identification of novel therapeutic targets for protozoan diseases, and in this context, apoptosis-like cell death has been reported in different groups of protozoa, in which metacaspases seem to play a role. In the genus , apoptotic markers have been detected in and , and no study focusing on cell death has been reported so far. In the present study, we investigated the susceptibility of to undergo apoptotic cell death after incubating mature trophozoites with the classical apoptosis inducer staurosporine.

Theories of immune recognition: Is anybody right?

The clonal selection theory (CST) is the centrepiece of the current paradigm used to explain immune recognition and memory. Throughout the past decades, the original CST had been expanded and modified to explain new experimental evidences since its original publication by Burnet. This gave origin to new paradigms that govern experimental immunology nowadays, such as the associative recognition of antigen model and the stranger/danger signal model.

Molecular Surveillance of Artemisinin-Resistant Parasites in Mining Areas of the Roraima Indigenous Territory in Brazil.

Multidrug- and artemisinin-resistant (ART-R) parasites represent a challenge for malaria elimination worldwide. Molecular monitoring in the Kelch domain region gene allows tracking mutations in parasite resistance to artemisinin. The increase in illegal miners in the Roraima Yanomami indigenous land (YIL) could favor ART-R parasites.

Relapsing malaria in a 12-year-old Brazilian girl: A case report.

causes the vast majority of malaria cases in Brazil. The lifecycle of this parasite includes a latent stage in the liver, the hypnozoite. Reactivation of hypnozoites induces repeated relapses.

Profile of metacaspase gene expression in Plasmodium vivax field isolates from the Brazilian Amazon.

Background: Metacaspases comprise a family of cysteine proteases implicated in both cell death and cell differentiation of protists that has been considered a potential drug target for protozoan parasites. However, the biology of metacaspases in Plasmodium vivax - the second most prevalent and most widespread human malaria parasite worldwide, whose occurrence of chemoresistance has been reported in many endemic countries, remains largely unexplored. Therefore, the present study aimed to address, for the first time, the expression pattern of metacaspases in P.

A nanochitosan-D-galactose formulation increases the accumulation of primaquine in the liver.

Primaquine is the mainstream antimalarial drug to prevent 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.

Are and Gene Mutations Associated with Chloroquine-Resistant Parasites?

(1) Background: Malaria remains a significant global public health issue. Since parasites quickly became resistant to most of the available antimalarial drugs, treatment effectiveness must be constantly monitored. In Brazil, up to 10% of cases of vivax malaria resistant to chloroquine (CQ) have been registered.

Building-blocks to develop one health systems.

Notwithstanding the understandable rationale of the logical, expected and natural evolution of human behaviour towards an anthropocentric view of its relationship with other animals and the environment, a shift from this predatory "Ego-centric" behaviour towards an "Eco" conduct, with regard to their view of the world and of the global health, has become mandatory, contributing to the development of the "One Health" and of "One Health Systems" concepts. We contend for the usefulness of a building-blocks approach to facilitate an understanding of the development of One Health Systems. We assert that a building-blocks approach to One Health Systems with strong similarity to WHO's building-blocks for human health systems would help to strengthen the case for robust,resilient and anti-fragile One Health systems.

IgM antibody responses against antigens in neotropical primates in the Brazilian Atlantic Forest.

Introduction: Zoonotic transmission is a challenge for the control and elimination of malaria. It has been recorded in the Atlantic Forest, outside the Amazon which is the endemic region in Brazil. However, only very few studies have assessed the antibody response, especially of IgM antibodies, in Neotropical primates (NP).

A fatal respiratory complication of malaria caused by Plasmodium vivax.

Background: Malaria is endemic and represents an important public health issue in Brazil. Knowledge of risk factors for disease progression represents an important step in preventing and controlling malaria-related complications. Reports of severe forms of Plasmodium vivax malaria are now becoming a common place, but respiratory complications are described in less than 3% of global literature on severe vivax malaria.

Construction, Expression, and Evaluation of the Naturally Acquired Humoral Immune Response against RMC-1, a Multistage Chimeric Protein.

The PvCelTOS, PvCyRPA, and Pvs25 proteins play important roles during the three stages of the lifecycle. In this study, we designed and expressed a recombinant modular chimeric protein (PvRMC-1) composed of the main antigenic regions of these vaccine candidates. After structure modelling by prediction, the chimeric protein was expressed, and the antigenicity was assessed by IgM and IgG (total and subclass) ELISA in 301 naturally exposed individuals from the Brazilian Amazon.

Interplay Between the Immune and Nervous Cognitive Systems in Homeostasis and in Malaria.

The immune and nervous systems can be thought of as cognitive and plastic systems, since they are both involved in cognition/recognition processes and can be architecturally and functionally modified by experience, and such changes can influence each other's functioning. The immune system can affect nervous system function depending on the nature of the immune stimuli and the pro/anti-inflammatory responses they generate. Here we consider interactions between the immune and nervous systems in homeostasis and disease, including the beneficial and deleterious effects of immune stimuli on brain function and the impact of severe and non-severe malaria parasite infections on neurocognitive and behavioral parameters in human and experimental murine malaria.

Visiting Molecular Mimicry Once More: Pathogenicity, Virulence, and Autoimmunity.

The concept of molecular mimicry describes situations in which antigen sharing between parasites and hosts could benefit pathogen evasion from host immune responses. However, antigen sharing can generate host responses to parasite-derived self-like peptides, triggering autoimmunity. Since its conception, molecular mimicry and the consequent potential cross-reactivity following infections have been repeatedly described in humans, raising increasing interest among immunologists.

Chloroquine- Resistant Haplotypes in Brazilian Endemic Areas Four Decades after CQ Withdrawn.

(1) Background: Malaria is a public health problem worldwide. Despite global efforts to control it, antimalarial drug resistance remains a great challenge. In 2009, our team identified, for the first time in Brazil, chloroquine (CQ)-susceptible parasites in isolates from the Brazilian Amazon.

A short history of innate immunity.

Innate immunity refers to the mechanisms responsible for the first line of defense against pathogens, cancer cells and toxins. The innate immune system is also responsible for the initial activation of the body's specific immune response (adaptive immunity). Innate immunity was studied and further developed in parallel with adaptive immunity beginning in the first half of the 19th century and has been gaining increasing importance to our understanding of health and disease.