Maternal consumption of polyphenol-rich foods in late pregnancy and fetal ductus arteriosus flow dynamics

OBJECTIVE

To test the hypothesis that maternal consumption of polyphenol-rich foods during third trimester interferes with fetal ductal dynamics by inhibition of prostaglandin synthesis.

STUDY DESIGN

In a prospective analysis, Doppler ductal velocities and right-to-left ventricular dimensions ratio of 102 fetuses exposed to polyphenol-rich foods (daily estimated maternal consumption >75th percentile, or 1089 mg) were compared with 41 unexposed fetuses (flavonoid ingestion <25th percentile, or 127 mg).

RESULT

In the exposed fetuses, ductal velocities were higher (systolic: 0.96+/-0.23 m/s; diastolic: 0.17+/-0.05 m/s) and right-to-left ventricular ratio was higher (1.23+/-0.23) than in unexposed fetuses (systolic: 0.61+/-0.18 m/s, P<0.001; diastolic: 0.11+/-0.04 m/s, P=0.011; right-to-left ventricular ratio: 0.94+/-0.14, P<0.001).

CONCLUSION

As maternal polyphenol-rich foods intake in late gestation may trigger alterations in fetal ductal dynamics, changes in perinatal dietary orientation are warranted.

ATIVIDADE ANTIMICROBIANA DO MEL DA ABELHA NATIVA SEM FERRÃO NANNOTRIGONA TESTACEICORNIS (HYMENOPTERA: APIDAE, MELIPONINI)

RESUMO Diversas propriedades medicinais como antibacteriana, antifúngica, cicatrizante e antioxidante são popularmente relatadas ao mel. Poucos estudos têm sido realizados sobre atividade antimicrobiana (AA) do mel de abelhas sociais da subfamília Meliponinae. O objetivo deste estudo foi investigar a AA do mel de Nannotrigona testaceicornis, uma espécie de abelha indígena sem ferrão. Para a avaliação da AA do mel foi empregado o método da difusão em ágar, utilizando-se discos de 6 mm de diâmetro em presença de 10 diferentes microrganismos, obtidos de focos de infecções clínicas. Os testes indicaram resistência em: Enterobacter aerogenes, Enterobacter cloacae, Proteus mirabilis, Staphylococcus aureus, Streptococcus ? -hemolítico; e indicaram sensibilidade em: Escherichia coli, Proteus spp., Pseudomonas aeruginosa, Streptococcus pyogenes, bem como Staphylococcus spp. coagulase. Vinte e três antibióticos comerciais distintos foram também avaliados no presente estudo. Os resultados obtidos até o momento apontam para um excelente potencial terapêutico deste produto apícola.

ESTUDO COMPARATIVO DA ATIVIDADE ANTIMICROBIANA DE EXTRATOS DE ALGUMAS ÁRVORES NATIVAS

RESUMO Este estudo avaliou as atividades antimicrobianas (AA) de extratos hidro-alcoólicos, obtidos de 17 espécies de árvores nativas do Brasil. Para os ensaios de antibiose foi utilizado o método da difusão em ágar, frente a 10 diferentes microrganismos, isolados de inóculos obtidos de focos de infecções clínicas. Dos 170 testes realizados, 25% mostraram alta AA, destacando-se extratos de Bixaorellana, Psidiumguajava e Anacardium occidentale. Excepcional AA foi observada em Mimosa tenuiflora contra Streptococcus pyogenes, Proteus mirabilis, Shigella sonnei, Staphylococcus aureus e Staphylococcus spp. coagulase-negativa, e os extratos de Stryphnodendron adstringens e Eugenia uniflora contra Escherichia coli, Providencia spp., Streptococcus pyogenes, Proteus mirabilis, Shigella sonnei, Staphylococcus aureus e Staphylococcus spp. coagulase-negativa. Ensaios de antibiose com antibióticos comerciais foram realizados contra estas bactérias, com a finalidade de se comparar o potencial de AA de extratos destas árvores.

PRÓPOLIS: UMA REVISÃO DOS RECENTES ESTUDOS DE SUAS PROPRIEDADES FARMACOLÓGICAS

RESUMO Própolis de Apis mellifera L. (Hymenoptera, Apidae) é um produto da colméia, elaborado a partir de exsudatos de resinas que as abelhas recolhem de determinadas plantas. A composição química da própolis é complexa e relacionada à diversidade vegetal encontrada em torno da colméia. Embora a própolis seja utilizada em medicina popular por milhares de anos, a falta de padrões que avaliem de maneira precisa suas atividades farmacológicas, dificulta a estandardização de produtos comerciais que garanta sua eficácia e segurança terapêutica para humanos e outros animais. Nesta revisão estão sumarizados alguns desenvolvimentos recentes da pesquisa farmacológica da própolis, enfocando-se as atividades antiinflamatórias, antimicrobianas, antineoplásica e antioxidante.

Mouse ear edema modulation by different propolis ethanol extracts

The anti-inflammatory activity of 14 commercial ethanol extracts of propolis were evaluated, using a mouse ear inflammation model induced by arachidonic acid. Indometacin was also assayed as standard anti-inflammatory agent. Different activities were observed and discussed. This model could be used to assess the anti-inflammatory quality of propolis extracts and facilitate their posological usage on skin edema resulting from wounds.

Resistance of Trypanosoma cruzi to blood clearance induced by acute-phase immune mouse serum

To investigate functional changes in Trypanosoma cruzi parasites induced during their interaction with the vertebrate host, we compared the blood clearance profiles of blood forms isolated from infected normal mice (Reg-Tc) or from infected mice immunodepressed after treatment with cyclophosphamide (Cy-Tc). Parasite blood numbers were measured at various time intervals in animals injected intravenously (i.v.) with 1-2 x 10(6) T. cruzi of either isolate. In the absence of added immune sera (spontaneous clearance), Reg-Tc and Cy-Tc were cleared from blood at similar rates. However, when acute immune mouse serum (Ac-IMS) was injected i.v. 2 min after inoculation of parasites, a significant proportion of Cy-Tc only was cleared from the blood an hour later, whereas Reg-Tc were not, their clearance profile being identical to that observed in mice injected with normal mouse serum. Cy-Tc susceptibility to Ac-IMS was not the result of a toxic effect of cyclophosphamide over T. cruzi as parasites recovered from animals immunodepressed by irradiation before infection were cleared similarly by acute serum. Contrary to Ac-IMS, chronic immune mouse serum induced similar rates of disappearance of Reg-Tc and Cy-Tc from blood. Our results suggest the occurrence of T. cruzi selection or modification during the acute phase, which leads to an increased parasite resistance to the clearance properties of acute-phase antibodies.

Evolution of subpatent parasitaemia in Trypanosoma cruzi chronically infected mice with the help of a cyclophosphamide amplification transfer assay

We have evaluated the sensitivity of the classical blood subinoculation method, modified through cyclophosphamide treatment of transferred mice, for the detection of occult parasitaemias in Trypanosoma cruzi chronically infected mice. Besides its simplicity, the method was shown to be highly sensitive for both the "chronic" phase parasites (99% of chronic cases were shown to harbour occult parasitaemias) and for the acute phase parasites (T. cruzi could be detected in 53.8% of animals transferred with one Y strain parasite and in 20% of animals transferred with one CL strain parasite). Using acute phase bloodforms, the assay proved to be more sensitive than conventional subinoculation when dealing with the CL, but not the Y strain of the parasite. With the help of this parasite detection tool, we have studied during a one year period, the evolution of subpatent parasitaemias in a group of mice which survived through chemotherapy from lethal acute phase of T. cruzi infection. Cyclophosphamide transfer assay revealed occult parasitaemias in 100% of the chronic animals, nevertheless, continuous and discontinuous patterns of positivity were observed.

Vaccination of Callithrix jacchus (Linné, 1758) marmosets with the PF strain of Trypanosoma cruzi

Callithrix jacchus marmosets, vaccinated more than once with high doses of the PF strain of Trypanosoma cruzi, showed a certain degree of parasitemia related to the number of parasites injected. Thirty days after vaccination, all animals were alive and showed no apparent morbid symptoms. The relationship between the dose of injected trypanosomes and the observed parasitemias is discussed and analysed as well as the immunologic incompetence of the experimental animals used.

The effect of an immune RNA (RNAi) against Trypanosoma cruzi infection in mice

Immune ribonucleic acid (RNAi) was extracted with phenol from the spleen of mice immunized with the avirulent PF strain of Trypanosoma cruzi. These preparations were able to induce immunocompetent cells to answer as a secondary response to later challenges with the virulent Y strain of the same parasite. The preparations of RNAi were"immunogenic" and free of proteins. The RNAi preparations were sensitive to pancreatic RNAase and lost their immune effect when pretreated with this enzyme. The injections of normal RNA (RNAn) obtained by the same method showed that this polymer acts as an immuno supressor or competitive agent. The electrophoretic profiles of the RNAi preparations in polyacrylamide gels showed normal and characteristic migration patterns (28S, 18S and 4.5S). These results demonstrate the development of an immune state against T. cruzi infection in mice injected with RNAi, in the absence of living parasites.

The protective effect of the epimastigote forms of the PF strain of Trypanosoma cruzi against a virulent homologous infection

Epimastigotes are assumed to be non-infective forms of trypanosomes. However, epimastigotes of the PF strain of the Trypanosoma cruzi when injected in mice, in a single low dose, conferred on the animals a very good protection against challenge of a virulent homologous strain.