Evaluation of Antimalarial Activity and Toxicity of a New Primaquine Prodrug

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

Toxicity of cryoprotectants on Prochilodus lineatus (Valenciennes, 1837) (curimba) embryos in an experimental incubator (Characiformes: Prochilodontidae)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Análises morfológica e histoquímicas do ventrículo e do cérebro de operárias recém emergidas de Apis Mellifera L. (Hymenoptera, Apidae) tratadas com Thiamethoxam

Apis mellifera honeybees are social insects of economic importance, by providing honeybee products, and by the pollination of natural areas of vegetation or agricultural areas. The constant use of pesticides, including the thiamethoxam, which is an insecticide belonging to the class of neonicotinoids with neurotoxic action, is subjecting pollinators to situations of severe stress, which has been evidenced by the decrease in the density of honeybees in many parts of the world. By these considerations, the present study aimed to assess the acute toxicity of thiamethoxam for newly emerged workers of A. mellifera, and to investigate the effect of sublethal doses of this insecticide on the survival time and its cytotoxicity to the brain and midgut to the honeybees. It was established the value of the lethal concentration 50 (LC50) equal to 4.28 ng thiamethoxam/μL of food and from it, the sublethal concentrations of 0.428 ng thiamethoxam/μL (CL50/10) and 0.0428 ng thiamethoxam/μL (CL50/100), which were used in bioassays of intoxication of the honeybees. After the bioassays the bees were dissected and the brain and midguts were collected to analyze possible morphological (staining with Hematoxylin-Eosin) and histochemical alterations (Xylidine Ponceau technique, and Feulgen and PAS reactions) caused by exposure to thiamethoxam, and to calculate the lethal time (LT50) for the workers. The duration of the bioassays was 8 days after beginning of feeding. The results obtained showed that the thiamethoxam is toxic to newly-emerged workers of A. mellifera, causing changes in survival time of individuals. This study also shown that the thiamethoxam causes morphological and histochemical alterations on the midgut and brain of workers. These alterations may be reflected in physiological and behavioral changes that can modify the operation of the colony

Hydroxyurea in the sickle cell anemia: toxicity and effectiveness

Objective: to evaluate the use of hydroxyurea with regard to effectiveness and toxicity in people with sickle cell anemia. Method: this is a retrospective descriptive study, developed with 57 medical records of patients with sickle cell anemia, treated at the University Hospital Center of Campo Grande (Mato Grosso do Sul, Brazil), from 1993 to 2005. Inclusion criteria: electrophoresis of hemoglobin in medical record; regular use of drugs, for an average of 196 weeks; dosage; and hematological analyses before starting treatment. Exclusion criteria: living with other hemoglobinopathies. The variables evaluated were: neutrophils count; platelets; leukocytes; hemoglobin; time using hydroxyurea; drug response to the optimal dosage; and number and type of episodes of hospitalization. The research protocol was approved by the Ethics Committee of Universidade Federal de Mato Grosso do Sul, under the Protocol 645. Results: of the 57 medical records, 3 cases were evaluated. Comparing the hematological values, according to Portaria 872, enacted on 11/12/2002, it was found that: cases A, B, and C present an use of hydroxyurea (500 mg/day) for four years, with an average of 196 weeks. Case A, female, decreased painful episodes and frequency of hospitalization, keeping hematological values with no toxicity. In Case B, female, there was one hospitalization due to pain crises and important hemolysis. It stood out, in case C, male, neutropenia with hematological values < 2,000/mm3 . Conclusion: in the cases analyzed, we observed a drop in the number of hospitalizations with the decrease in painful crises from three to one a year, and there was no toxicity with regard to the dosage and time using hydroxyurea, in all three cases. For more comprehensive results, one suggests further study on this therapy with significant samples of this clientele.

Genotoxic activity and toxicity of Baccharis trimera Less. regarding the bioaccumulation of heavy metals

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

Avaliação dos efeitos de concentrações subletais de dimetoato no cérebro e ventrículo de Apis mellifera africanizada

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Genotoxic effect of photodynamic therapy mediated by curcumin on Candida albicans

Photodynamic therapy (PDT) is a promising method for localized and specific inactivation of fungi and bacteria. A nontoxic light-sensitive compound is taken up by cells, which are then exposed selectively to light, which activates toxicity of the compound. We investigated the potential of sublethal PDT using light-sensitive curcumin (CUR) in combination with blue (455 nm) light to promote reactive oxygen species (ROS) formation in the form of singlet oxygen and DNA damage of Candida albicans. Surprisingly, CUR-mediated PDT but also light alone caused significantly longer comet tails, an indication of DNA damage of C. albicans when compared with the negative control. The intracellular ROS production was also significantly higher for the group treated only with light. However, PDT compared to blue light alone significantly slowed DNA repair. Comet tails decreased during 30 min visualized as a 90% reduction in length in the absence of light for cells treated with light alone, while comet tails of cells treated with PDT only diminished in size about 45%. These results indicate that complex mechanisms may result in PDT in a way that should be considered when choosing the photosensitive compound and other aspects of the treatment design.

Mortalidade e efeitos subletais de Bacillus thuringiensis Berliner em Spodoptera albula (Walker, 1857)

Pós-graduação em Agronomia (Entomologia Agrícola) - FCAV

In vivo evaluation of the genetic toxicity of Rubus niveus Thunb. (Rosaceae) extract and initial screening of its potential chemoprevention against doxorubicin-induced DNA damage

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

Chitosan nanoparticles loaded the herbicide paraquat: The influence of the aquatic humic substances on the colloidal stability and toxicity

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

Biomarker evaluation in fish after prolonged exposure to nano-TiO2: influence of illumination conditions and crystal phase

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

Antiulcerogenic activity and toxicity of bauhinia holophylla hydroalcoholic extract

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

Toxicity of imidacloprid to the stingless bee Scaptotrigona postica Latreille, 1807 (Hymenoptera: Apidae)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)