ATIVAÇÃO in vitro DO SISTEMA COMPLEMENTO COMO MECANISMO IMUNOMODULADOR INDUZIDO PELO MESOCARPO DE BABAÇU

O babaçu (Orbignya phalerata Mart), palmeira que representa o mais importante produto do extrativismo vegetal do  Maranhão,  produz  um  fruto,  côco  babaçu,  composto  predominantemente  por  carboidratos  e  que  apresenta  efeitos imunomodulatórios. O objetivo deste trabalho foi verifcar o potencial imunomodulador do mesocarpo de babaçu por ativação do sistema complemento. Foi utilizado o extrato aquoso de mesocarpo de babaçu, na concentração de 40 mg/mL e fltrado após 24 horas. A dosagem de proteínas  foi  realizada pelo método colorimétrico de Bradford. No ensaio hemaglutinante, usou-se um  lavado de hemácias 1%  tratadas por uma hora com extrato nas concentrações de 1,25, 2,5, 5, 10, 20 e 40mg/mL,   em  triplicata,  tendo como controle a suspensão de hemácias com  tampão salina fosfato. A aglutinação foi verifcada macro  e microscopicamente,  com  a  contagem  de  rosetas. O  ensaio  de  hemólise  foi  feito  usando  o  lavado  de  hemácias tratadas ou não com extrato na concentração de 40mg/mL, incubado por duas horas com soro normal ou inativado a 56°C, para verifcar desnaturação protéica. A concentração de hemoglobina no  sobrenadante da cultura  representou a atividade hemolisante. Nossos resultados mostraram que ensaio de hemaglutinação não apresentou diferença macroscópica entre os grupos. Microscópicamente, a presença de rosetas seguiu um padrão dose-dependente, sugerindo a presença de lectina no extrato,  entretanto  a  dosagem  de  proteínas  apresentou  concentrações  baixas. No  ensaio  de  hemólise,  a  concentração  de hemoglobina  foi maior na  cultura de hemácias  tratadas  com  extrato que o  controle. Para  confrmar  a  ação das proteinas do complemento, as hemácias tratadas com extrato foram incubadas com soro inativado, sendo verifcada uma redução da hemólise, se igualando ao controle. Os resultados mostram que o efeito imunomodulador do mesocapo de babaçu apresenta a participação do sistema complemento, possivelmente através da via das lectinas.Descritores: Mesocarpo de babaçu. Imunomodulação. Sistema Complemento; Lectinas. Carboidrato. AbstractEvaluation of complement system activation  in vitro as an  immunomodulation mechanism  induced by babassu mesocarp. Babassu (Orbignya phalerata Mart.), palm tree that represents the most important product extractive industry of Maranhão, produces a fruit, babassu coconut, composed mainly for carbohydrates and has immunomodulatory effects. The aim of the study was to investigate the immunomodulatory potencial of babassu mesocarp by activation of the complement system. We used the aqueous extract of babassu mesocarp concentration of 40 mg/mL and fltered after 24 hours. The measure protein concentration was performed by the colorimetric method of Bradford. In the hemagglutination assay was used a suspension of erythrocytes 1% treated or not  for one hour with extract concentrations 1,25, 2,5, 5, 10, 20 e 40mg/mL  in  triplicate, using  the suspension of erythrocytes  in phosphate buffered saline as control. Agglutination was observed macroscopically and microscopically by counting rosettes. The hemolysis assay was performed using the suspension of erythrocytes treated or not with extract concentration 40 mg/mL, incubated for two hours with normal serum or inactivated at 56º to check protein denaturation. Hemoglobin concentration in the in the culture supernatant represented hemolyzing  activity. Our  results  showed  that  hemagglutination  assay  showed  no macroscopic  difference  between  the groups. Microscopically,  the  presence  of  rosettes  followed  a  dose-dependent,  suggesting  the  presence  of  lectin  in  the extract, however measure protein showed low concentrations. In hemolysis assay, the concentration of hemoglobin was higher  in  culture  of  erythrocytes  treated with  extract  than  the  control. To  confrm  the  action  of  complement  proteins, erythrocytes treated with extract were incubated with inactivated serum, being observed a reduction of hemolysis similar to  control.  The  results  show  that  the  immunomodulatory  effect  of  babassu mesocarp  shows  the  participation  of  the complement system, possibly by way of lectins.Descriptors: Babassu Mesocarp. Immunomodulation. Complement System. Lectins. Carbohydrate

Trypanosoma cruzi Immune Response Modulation Decreases Microbiota in Rhodnius prolixus Gut and Is Crucial for Parasite Survival and Development

Trypanosoma cruzi in order to complete its development in the digestive tract of Rhodnius prolixus needs to overcome the immune reactions and microbiota trypanolytic activity of the gut. We demonstrate that in R. prolixus following infection with epimastigotes of Trypanosoma cruzi clone Dm28c and, in comparison with uninfected control insects, the midgut contained (i) fewer bacteria, (ii) higher parasite numbers, and (iii) reduced nitrite and nitrate production and increased phenoloxidase and antibacterial activities. In addition, in insects pre-treated with antibiotic and then infected with Dm28c, there were also reduced bacteria numbers and a higher parasite load compared with insects solely infected with parasites. Furthermore, and in contrast to insects infected with Dm28c, infection with T. cruzi Y strain resulted in a slight decreased numbers of gut bacteria but not sufficient to mediate a successful parasite infection. We conclude that infection of R. prolixus with the T. cruzi Dm28c clone modifies the host gut immune responses to decrease the microbiota population and these changes are crucial for the parasite development in the insect gut

Acceptability of an open-label wait-listed trial design: Experiences from the PROUD PrEP study

Background PROUD participants were randomly assigned to receive pre-exposure prophylaxis (PrEP) immediately or after a deferred period of one-year. We report on the acceptability of this open-label wait-listed trial design. Methods Participants completed an acceptability questionnaire, which included categorical study acceptability data and free-text data on most and least liked aspects of the study. We also conducted in-depth interviews (IDI) with a purposely selected sub-sample of participants. Results Acceptability questionnaires were completed by 76% (415/544) of participants. After controlling for age, immediate-group participants were almost twice as likely as deferred-group participants to complete the questionnaire (AOR:1.86;95%CI:1.24,2.81). In quantitative data, the majority of participants in both groups found the wait-listed design acceptable when measured by satisfaction of joining the study, intention to remain in the study, and interest in joining a subsequent study. However, three-quarters thought that the chance of being in the deferred-group might put other volunteers off joining the study. In free-text responses, data collection tools were the most frequently reported least liked aspect of the study. A fifth of deferred participants reported ‘being deferred’ as the thing they least liked about the study. However, more deferred participants disliked the data collection tools than the fact that they had to wait a year to access PrEP. Participants in the IDIs had a good understanding of the rationale for the open-label wait-listed study design. Most accepted the design but acknowledged they were, or would have been, disappointed to be randomised to the deferred group. Five of the 25 participants interviewed reported some objection to the wait-listed design. Conclusion The quantitative and qualitative findings suggest that in an environment where PrEP was not available, the rationale for the wait-listed trial design was well understood and generally acceptable to most participants in this study

Nutrition, mental health and violence: from pregnancy to postpartum Cohort of women attending primary care units in Southern Brazil - ECCAGE study

<p>Abstract</p> <p>Background</p> <p>Woman's nutritional status, before and during pregnancy, is a strong determinant of health outcomes in the mother and newborn. Gestational weight gain and postpartum weight retention increases risk of overweight or obesity in the future and they depend on the pregestational nutritional status and on food consumption and eating behavior during pregnancy. Eating behavior during pregnancy may be the cause or consequence of mood changes during pregnancy, especially depression, which increases likelihood of postpartum depression. In Brazil, a study carried out in the immediate postpartum period found that one in three women experienced some type of violence during pregnancy. Violence and depression are strongly associated and both exposures during pregnancy are associated with increased maternal stress and subsequent harm to the infant. The main objectives of this study are: to identify food intake and eating behaviors patterns; to estimate the prevalence of common mental disorders and the experience of violence during and after pregnancy; and to estimate the association between these exposures and infant's health and development.</p> <p>Methods/Design</p> <p>This is a cohort study of 780 pregnant women receiving care in 18 primary care units in two cities in Southern Brazil. Pregnant women were first evaluated between the 16^thand 36^thweek of pregnancy at a prenatal visit. Follow-up included immediate postpartum assessment and around the fifth month postpartum. Information was obtained on sociodemographic characteristics, living circumstances, food intake, eating behaviors, mental health and exposure to violence, and on infant's development and anthropometrics measurements.</p> <p>Discussion</p> <p>This project will bring relevant information for a better understanding of the relationship between exposures during pregnancy and how they might affect child development, which can be useful for a better planning of health actions aiming to enhance available resources in primary health care.</p