Metemoglobinemia em pacientes com malária por Plasmodium vivax em uso oral de primaquina

A primaquina pode acarretar sérios eventos adversos, com destaque para a toxicidade ao sangue. O objetivo deste trabalho é determinar a metemoglobinemia de 20 pacientes com malária por Plasmodium vivax tratados com primaquina, comparando-os segundo o sexo e a expressão da glicose-6-fosfato desidrogenase. Métodos: Quantificação da metemoglobina por espectrofotometria visível e avaliação qualitativa da glicose-6-fosfato desidrogenase. Resultados: A metemoglobinemia variou de 2,85 a 5,45% nos pacientes do sexo masculino e de 3,77 a 7,34% no feminino. Conclusões: A instituição da terapia aumentou de maneira significativa os teores de metemoglobina, sem manifestação clínica evidente e independente do sexo e da atividade enzimática.

Concentrações plasmáticas de primaquina e metemoglobinemia em pacientes com malária por Plasmodium vivax

A malária vivax é uma doença que a cerca de 40% da população mundial, utiliza-se no tratamento desta, cloroquina (150 mg) e primaquina (15 mg). Esta é uma 8- aminoquinolina com ação esquizonticida tecidual. Dentre seus efeitos adversos se destaca a capacidade de oxidar a hemoglobina, de maneira dose dependente, que é agravada nos indivíduos com deficiência da glicose-6-fosfato desidrogenase. Ao se considerar a ausência de estudos referentes aos teores de metemoglobina e sua correlação com as concentrações plasmáticas de primaquina nos pacientes com malária vivax, justifica-se a realização deste estudo empregando-se como ferramentas a monitorização das concentrações sanguíneas de primaquina e sua correlação com os teores de metemoglobina. Neste sentido, foi realizado seguimento clínico-laboratorial de 20 pacientes com malária vivax antes (D0) e após três (D3), sete (D7) e quatorze (D14) dias iniciado o tratamento, bem como a validação do método para determinação de primaquina por cromatografia líquida de alta eficiência (CLAE). A metemoglobinemia foi avaliada pela técnica de Hegesh et al. (1970) e a glicose-6-fosfato desidrogenase pelo teste colorimétrico de Brewer et al. (1962). A metodologia validada demonstrou parâmetros aplicáveis à determinação de primaquina, cujos teores médios em D3, D7 e D14 foram de 227±106 ng/mL, 191±97 ng/mL e 160±128ng/mL. Não foram obervadas diferenças significativas nas concentrações do fármaco quanto ao sexo dos pacientes participantes e nos diversos dias do estudo. Os teores médios de metemoglobina em D0, D3, D7 e D14 foram de 1,15±0,9%, 4,1±2%, 5,7±2% e 3±1,4%, respectivamente. Foi observado aumento no teor de metemoglobina após administração do fármaco, sem diferença quanto ao sexo. Não foi observada correlação significativa entre os teores de metemoglobina e as concentrações plasmáticas de primaquina em ambos os sexos. Os coeficientes de correlação de Pearson para os sexos masculino e feminino foram 0.8296 e 0.8137, respectivamente. Foi observada deficiência da expressão da enzima glicose-6- fosfato desidrogenase em seis pacientes do sexo masculino sem diferenças entre os teores de metemoglobina e das concentrações plasmáticas de Primaquina, quando comparados com pacientes com expressão normal da enzima.

Influence of salts on the coexistence curve and protein partitioning in nonionic aqueous two-phase micellar systems

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Evaluation of Antimalarial Activity and Toxicity of a New Primaquine Prodrug

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Hematological and biochemical changes in a Phrynops geoffroanus (Schweigger, 1812) population in response to environmental stressors

Turtles are among the most endangered vertebrate groups, and the main threats to populations are environmental pollution and habitat degradation. The species Phrynops geoffroanus, popularly known as “Geoffroy’s side-necked turtle”, has proliferated in polluted environments, where adverse conditions could influence their living habits and physiological condition. Studies that monitor the effects of environmental pollution are key to understanding the species’ biology and designing effective conservation strategies. Thus, the analysis of hematological and biochemical parameters has been shown to be important in assessing the health of wild animals and risks for the animal and ecosystem. This study aimed to assess the environmental influence on the physiology of a P. geoffroanus population through the evaluation of antioxidant status and responses to environmental stressors, compared to specimens from a place under controlled conditions. Blood samples of 60 specimens were collected, 30 from the Felicidade Stream, polluted environment, within the city of São José do Rio Preto, and 30 from the “Reginaldo Uvo Leone” breeding farm, Tabapuã, SP, a place under controlled conditions, whose samples constituted the control group. They were evaluated by hemogram and by determining thiobarbituric acid reactive species (TBARS), Trolox-equivalent antioxidant capacity (TEAC) and the activities of the antioxidant enzymes catalase and glucose-6-phosphate dehydrogenase (G6PDH). There was a wide variation in hematological parameters of P. geoffroanus from the urban environment. The red blood cell count and hemoglobin values were significantly less than those observed in animals from the breeding farm (P = 0.0004; P = 0.0371, respectively). There was a significant increase in the number of thrombocytes (P < 0.0001) and leukocytes (P < 0.0001) in the animals from Felicidade Stream. The stress indices were similar between the two groups (P = 0.4077). TBARS levels showed the cytotoxic potential of compounds in the urban environment, whose animals had elevated levels of lipid peroxidation (P < 0.0001), despite showing a response to environmental damages with increase in antioxidant capacity, as demonstrated by the TEAC assay (P = 0.0207). The lower catalase enzyme activity noted in individuals from the urban environment (P = 0.000184) could be due to the presence of inhibitory compounds. On the other hand, G6PDH activity was higher (P = 0.002962), where this enzyme acts in the generation of NADPH, which is used in several detoxification pathways. We conclude that environmental contamination can increase oxidative damages and generate physiological changes in this species. These data are very useful for the conservation of P. geoffroanus and turtles in general, and confirm that these techniques are effective in monitoring natural regions and that P. geoffroanus can serve as an environmental contamination bioindicator.

A protein kinase screen of Neurospora crassa mutant strains reveals that the SNF1 protein kinase promotes glycogen synthase phosphorylation

Glycogen functions as a carbohydrate reserve in a variety of organisms and its metabolism is highly regulated. The activities of glycogen synthase and glycogen phosphorylase, the rate-limiting enzymes of the synthesis and degradation processes, respectively, are regulated by allosteric modulation and reversible phosphorylation. To identify the protein kinases affecting glycogen metabolism in Neurospora crassa, we performed a screen of 84 serine/threonine kinase knockout strains. We identified multiple kinases that have already been described as controlling glycogen metabolism in different organisms, such as NcSNF1, NcPHO85, NcGSK3, NcPKA, PSK2 homologue and NcATG1. In addition, many hypothetical kinases have been implicated in the control of glycogen metabolism. Two kinases, NcIME-2 and NcNIMA, already functionally characterized but with no functions related to glycogen metabolism regulation, were also identified. Among the kinases identified, it is important to mention the role of NcSNF1. We showed in the present study that this kinase was implicated in glycogen synthase phosphorylation, as demonstrated by the higher levels of glycogen accumulated during growth, along with a higher glycogen synthase (GSN) ±glucose 6-phosphate activity ratio and a lesser set of phosphorylated GSN isoforms in strain Ncsnf1KO, when compared with the wild-type strain. The results led us to conclude that, in N. crassa, this kinase promotes phosphorylation of glycogen synthase either directly or indirectly, which is the opposite of what is described for Saccharomyces cerevisiae. The kinases also play a role in gene expression regulation, in that gdn, the gene encoding the debranching enzyme, was down-regulated by the proteins identified in the screen. Some kinases affected growth and development, suggesting a connection linking glycogen metabolism with cell growth and development.

Ajuste metabólico e respostas imunes de pacus juvenis alimentados com diferentes níveis de carboidratos e submetidos a jejum prolongado

Pós-graduação em Zootecnia - FCAV

Mycorrhization alters foliar soluble amino acid composition and influences tolerance to Pb in Calopogonium mucunoides

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Influência da temperatura nas respostas aos biocidas diazinon e carbaril em Dilocarcinus pagei Stimpson, 1861

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Metabolismo do malondialdeído em peixes: implicações na avaliação da peroxidação lipídica como biomarcador de contaminação aquática

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Metabolismo do malondialdeído em peixes: implicações na avaliação da peroxidação lipídica como biomarcador de contaminação aquática

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Underlying Factors Associated with Anemia in Amazonian Children: A Population-Based, Cross-Sectional Study

Background: Although iron deficiency is considered to be the main cause of anemia in children worldwide, other contributors to childhood anemia remain little studied in developing countries. We estimated the relative contributions of different factors to anemia in a population-based, cross-sectional survey. Methodology: We obtained venous blood samples from 1111 children aged 6 months to 10 years living in the frontier town of Acrelandia, northwest Brazil, to estimate the prevalence of anemia and iron deficiency by measuring hemoglobin, erythrocyte indices, ferritin, soluble transferrin receptor, and C-reactive protein concentrations. Children were simultaneously screened for vitamin A, vitamin B-12, and folate deficiencies; intestinal parasite infections; glucose-6-phosphate dehydrogenase deficiency; and sickle cell trait carriage. Multiple Poisson regression and adjusted prevalence ratios (aPR) were used to describe associations between anemia and the independent variables. Principal Findings: The prevalence of anemia, iron deficiency, and iron-deficiency anemia were 13.6%, 45.4%, and 10.3%, respectively. Children whose families were in the highest income quartile, compared with the lowest, had a lower risk of anemia (aPR, 0.60; 95% CI, 0.37-0.98). Child age (<24 months, 2.90; 2.01-4.20) and maternal parity (>2 pregnancies, 2.01; 1.40-2.87) were positively associated with anemia. Other associated correlates were iron deficiency (2.1; 1.4-3.0), vitamin B-12 (1.4; 1.0-2.2), and folate (2.0; 1.3-3.1) deficiencies, and C-reactive protein concentrations (>5 mg/L, 1.5; 1.1-2.2). Conclusions: Addressing morbidities and multiple nutritional deficiencies in children and mothers and improving the purchasing power of poorer families are potentially important interventions to reduce the burden of anemia.

Assessment of the sublethal toxicity of organochlorine pesticide endosulfan in juvenile common carp (Cyprinus carpio)

This study is aimed at evaluating the sublethal effects of endosulfan (EDS) in juvenile common carp (Cyprinus carpio). For this purpose, fish were exposed for 15 days to the technical EDS (95% pure) diluted in dimethyl sulfoxide (DMSO) 0.1% of the total volume in water solution in a semi-static system at sublethal concentration (1 mu g/L). Subsequently, the liver somatic index (LSI) and factor condition (K) were determined. The total cytocrome P450 (CYP), CYP1A isoform, and the ethoxyresorufin-O-deethylase (EROD) activity were determined from the hepatic microsomal fraction as well as the activity of the oxidative stress enzyme system such as superoxide dismutase (SOD), catalase (CAT), glutathione-S-transferase (GST), glutathione peroxidase (GP(X)), glutathione reductase (GR), and glucose-6-phosphate dehydrogenase (G6PDH). Among the parameters assessed, EDS at the sublethal concentration in subchronic exposure caused significant changes in liver somatic indices as well as induction of the phase I biotransformation system and oxidative stress in juvenile common carp (Cyprinus carpio). Thus, it is seen that the use of biochemical biomarkers of environmental contamination in this study proved to be an extremely important tool for detecting the adverse effects of xenobiotics in the aquatic environment, even at low concentration.

RNA extraction from ten year old formalin-fixed paraffin-embedded breast cancer samples: a comparison of column purification and magnetic bead-based technologies

Abstract Background The development of protocols for RNA extraction from paraffin-embedded samples facilitates gene expression studies on archival samples with known clinical outcome. Older samples are particularly valuable because they are associated with longer clinical follow up. RNA extracted from formalin-fixed paraffin-embedded (FFPE) tissue is problematic due to chemical modifications and continued degradation over time. We compared quantity and quality of RNA extracted by four different protocols from 14 ten year old and 14 recently archived (three to ten months old) FFPE breast cancer tissues. Using three spin column purification-based protocols and one magnetic bead-based protocol, total RNA was extracted in triplicate, generating 336 RNA extraction experiments. RNA fragment size was assayed by reverse transcription-polymerase chain reaction (RT-PCR) for the housekeeping gene glucose-6-phosphate dehydrogenase (G6PD), testing primer sets designed to target RNA fragment sizes of 67 bp, 151 bp, and 242 bp. Results Biologically useful RNA (minimum RNA integrity number, RIN, 1.4) was extracted in at least one of three attempts of each protocol in 86–100% of older and 100% of recently archived ("months old") samples. Short RNA fragments up to 151 bp were assayable by RT-PCR for G6PD in all ten year old and months old tissues tested, but none of the ten year old and only 43% of months old samples showed amplification if the targeted fragment was 242 bp. Conclusion All protocols extracted RNA from ten year old FFPE samples with a minimum RIN of 1.4. Gene expression of G6PD could be measured in all samples, old and recent, using RT-PCR primers designed for RNA fragments up to 151 bp. RNA quality from ten year old FFPE samples was similar to that extracted from months old samples, but quantity and success rate were generally higher for the months old group. We preferred the magnetic bead-based protocol because of its speed and higher quantity of extracted RNA, although it produced similar quality RNA to other protocols. If a chosen protocol fails to extract biologically useful RNA from a given sample in a first attempt, another attempt and then another protocol should be tried before excluding the case from molecular analysis.

myo-Inositol uptake is essential for bulk inositol phospholipid but not glycosylphosphatidylinositol synthesis in Trypanosoma brucei

myo-Inositol is an essential precursor for the production of inositol phosphates and inositol phospholipids in all eukaryotes. Intracellular myo-inositol is generated by de novo synthesis from glucose 6-phosphate or is provided from the environment via myo-inositol symporters. We show that in Trypanosoma brucei, the causative pathogen of human African sleeping sickness and nagana in domestic animals, myo-inositol is taken up via a specific proton-coupled electrogenic symport and that this transport is essential for parasite survival in culture. Down-regulation of the myo-inositol transporter using RNA interference inhibited uptake of myo-inositol and blocked the synthesis of the myo-inositol-containing phospholipids, phosphatidylinositol and inositol phosphorylceramide; in contrast, it had no effect on glycosylphosphatidylinositol production. This together with the unexpected localization of the myo-inositol transporter in both the plasma membrane and the Golgi demonstrate that metabolism of endogenous and exogenous myo-inositol in T. brucei is strictly segregated.