Chronic infection during placental malaria is associated with up-regulation of cycloxygenase-2

<p>Abstract</p> <p>Background</p> <p>Placental malaria (PM) is associated with poor foetal development, but the pathophysiological processes involved are poorly understood. Cyclooxygenase (COX) and lipoxygenase (LOX) which convert fatty acids to prostaglandins and leukotrienes, play important roles in pregnancy and foetal development. COX-2, currently targeted by specific drugs, plays a dual role as it associates with both pre-eclampsia pathology and recovery during infection. The role of COX during PM was questioned by quantifying at delivery COX-1, COX-2, 15-LOX, and IL-10 expression in two groups of malaria infected and uninfected placenta.</p> <p>Methods</p> <p>Placental biopsies were collected at delivery for mRNA isolation and quantification, using real time PCR.</p> <p>Results</p> <p>COX-2 and IL-10 mRNAs increased mainly during chronic infections (nine- and five-times, respectively), whereas COX-1 transcripts remained constant. COX-2 over-expression was associated with a higher birth weight of the baby, but with a lower rate of haemoglobin of the mother. It was associated with a macrophage infiltration of the placenta and with a low haemozoin infiltration. In the opposite way, placental infection was associated with lower expression of 15-LOX mRNA. A high degree of haemozoin deposition correlates with low birth weight and decreased expression of COX-2.</p> <p>Conclusion</p> <p>These data provide evidence that COX-2 and IL-10 are highly induced during chronic infection of the placenta, but were not associated with preterm delivery or low birth weight. The data support the involvement of COX-2 in the recovery phase of the placental infection.</p

Contributions of a qualitative study in the understanding of health access and care practices in Southern Lao PDRCONTRIBUTIONS OF A QUALITATIVE STUDY IN THE UNDERSTANDING OF HEALTH ACCESS AND CARE PRACTICES IN SOUTHERN LAO PDR

Poster based on a master thesis on acess to medecine and care particies in southern Lao PDR - 201

High prevalence of placental malaria and low birth weight in Sahelian Periurban area

The impact of placental malaria in African urban areas is poorly documented. We therefore conducted a study during the rainy season in Dakar, an area with low malaria transmission. Two groups of delivering women were enrolled according to the detection of PfHRP2 in placental blood. Ten percent of the women were positive for parasites in the placenta, and microscopic examination showed, respectively, 17%, 22%, and 44% of past, acute, and chronic infection. The mean birth weight decreased drastically with the infection of the placenta (2,684 +/- 67 versus 3,085 +/- 66 g for controls), particularly with chronic infection. Chronic infection was not linked with parasiteamia in maternal venous blood. Seventy-six percent of positive women were anemic (46% of the controls). Severe anemia was also associated with chronic infection. Long-lasting infections are the most deleterious to mother and infant and are most likely associated with drug resistance of parasites

IgG responses to gSG6-P1 according to adult perception of mosquito bites.

<p>Anti-gSG6-P1 IgG responses represented according to the degree of perception of mosquito bites (Fig. 3a) and taking into account the use of bed nets (Fig. 3b). Boxes indicate the middle 50% of the data; horizontal lines in the boxes indicate medians of the individual data; lengths of boxes correspond to the inter-quartile ranges. In Fig. 3B, bed net and non-bed net users are represented white and grey boxes, respectively. The horizontal black dotted line represents the cut-off of IgG responder. Statistical significant differences of specific IgG between bed net and non-bed net users are indicated.</p

Proportion of use of vector control measures in the populations of 45 districts of Dakar urban region.

<p>The proportion of use in the total population (children and adults), children or adults was calculated for each type of vector control measure listed. The standard error of each proportion is indicated in brackets. “n” represents the effectiveness of individuals in each group. “Others” means simultaneous use of two or more of the listed vector control tools by populations.</p

Relationship between use of bed net and other vector control tools in the study population.

<p>Relationship between use of bed net and other vector control tools in the study population.</p

IgG responses to gSG6-P1 according to the use of ITN and age (in children) and sampling period (in adults).

<p>Specific IgG responses are shown for ITN (white boxes) and non-ITN (grey boxes) users according to age in children (Fig. 2a) and period of sampling in adults (Fig. 2b). Boxes indicate the middle 50% of the data; horizontal lines in the boxes indicate medians of the individual data; lengths of boxes correspond to the inter-quartile ranges. The horizontal black dotted line represents the cut-off of IgG responder and “n” the effectiveness of each individual group. Statistical significant differences of specific IgG between bed net and non-bed net users are indicated. October 1 and 2, November 1 and 2 and December 1 and 2 represent sampling periods between, respectively, 01^st –15^th and 16^th –31^st October, 01^st –15^th and 16^th –30^st November and 01^st –15^th and 16^th –31^st December 2008.</p

Factors influencing specific IgG response to gSG6-P1 peptide.

<p>Intercept = when the values of all independent variables are zero (e.g. the value of median IgG response in someone with no risk factors). The estimated coefficient and the degree of significance (p-value) are indicated. A positive coefficient means that the explanatory variable increases the probability of IgG response to gSG6-P1, while a negative coefficient means that the variable decreases the probability of IgG response to gSG6-P1.</p

Localization of the studied sites in Dakar.

<p>The 50 blood spot-sampling (in yellow) sites are proportionally localized on the map. Enclosed asterisks represent the 5 prosperous residential districts of the Dakar department in which the collected blood samples were not enough for several reasons. The 45 remaining districts in which sufficient blood spot-samples were collected for immunological assays are numbered from 1 to 45 on the map. DK, PK, GUE and RF are, respectively, Dakar, Pikine, Guediawaye and Rufisque, the four departments of Dakar region. The brown base of the map represents the area not inhabited by humans. The darker areas correlate with the presence of vegetation.</p