Plasmodium chabaudi: estradiol suppresses acquiring, but not once-acquired immunity.

This study investigates the effect of estradiol (E) on self-healing of Plasmodium chabaudi malaria in mice of the inbred strain C57BL/10. Our data show: (1) Female mice and male castrates are capable of self-healing infections when challenged with 10(6) P. chabaudi-infected erythrocytes. Self-healing is completely suppressed after pretreatment of mice with 12 micrograms E injected sc twice a week for 3 weeks. (2) The suppressive effect of E is prevented by the estrogen receptor blockers tamoxifen and clomiphene. (3) The nonsteroidal E-agonist diethylstilbestrol (DES) also suppresses self-healing. This suppressive DES effect is prevented by tamoxifen. (4) In mice immune to P. chabaudi, neither survival rate nor the course of parasitemia is affected by E, even at 10-fold higher E doses. Our data suggest that the immunosuppressive action of E is a specific genomic effect, i.e., E-induced gene products prevent the development of protective immunity against P. chabaudi.     

Adverse pregnancy outcomes are associated with Plasmodium vivax malaria in a prospective cohort of women from the Brazilian Amazon

BackgroundMalaria in Brazil represents one of the highest percentages of Latin America cases, where approximately 84% of infections are attributed to Plasmodium (P.) vivax. Despite the high incidence, many aspects of gestational malaria resulting from P. vivax infections remain poorly studied. As such, we aimed to evaluate the consequences of P. vivax infections during gestation on the health of mothers and their neonates in an endemic area of the Amazon.Methods and findingsWe have conducted an observational cohort study in Brazilian Amazon between January 2013 and April 2015. 600 pregnant women were enrolled and followed until delivery. After applying exclusion criteria, 329 mother-child pairs were included in the analysis. Clinical data regarding maternal infection, newborn’s anthropometric measures, placental histopathological characteristics, and angiogenic and inflammatory factors were evaluated. The presence of plasma IgG against the P. vivax (Pv) MSP1₁₉ protein was used as marker of exposure and possible associations with pregnancy outcomes were analyzed. Multivariate logistic regression analysis revealed that P. vivax infections during the first trimester of pregnancy are associated with adverse gestational outcomes such as premature birth (adjusted odds ratio [aOR] 8.12, 95% confidence interval [95%CI] 2.69–24.54, p < 0.0001) and reduced head circumference (aOR 3.58, 95%CI 1.29–9.97, p = 0.01). Histopathology analysis showed marked differences between placentas from P. vivax-infected and non-infected pregnant women, especially regarding placental monocytes infiltrate. Placental levels of vasomodulatory factors such as angiopoietin-2 (ANG-2) and complement proteins such as C5a were also altered at delivery. Plasma levels of anti-PvMSP1₁₉ IgG in infected pregnant women were shown to be a reliable exposure marker; yet, with no association with improved pregnancy outcomes.ConclusionsThis study indicates that P. vivax malaria during the first trimester of pregnancy represents a higher likelihood of subsequent poor pregnancy outcomes associated with marked placental histologic modification and angiogenic/inflammatory imbalance. Additionally, our findings support the idea that antibodies against PvMSP1₁₉ are not protective against poor pregnancy outcomes induced by P. vivax infections.     

Ein künstlich bestäubter Fruchtknoten vonYucca filamentosa

Ohne Zusammenfassung     

In situ remediation of aquifers contaminated with dense nonaqueous phase liquids by chemically enhanced solubilization

Chemically enhanced solubilization (CES) is an advanced variant of pump‐andtreat that results in more effective and more rapid remediation of groundwater contaminated with organic solvents and other dense nonaqueous‐phase liquids (DNAPLs). Attempts to remediate DNAPL‐contaminated groundwater by pump‐and‐treat have generally not been successful, due to the low aqueous solubility of most DNAPLs. Regions of undissolved, organic liquids slowly release additional contamination to surrounding groundwater, in effect acting as in situ sources of contamination and hindering the progress of remediation attempts. Cleaning up an aquifer can take many decades or more of pump‐and‐treat. CES accelerates pump‐and‐treat by using surfactants at low concentration to increase the solubility of organic contaminants by up to three orders of magnitude, while maintaining hydraulic control. The surfactants are chosen to maximize contaminant solubilization while minimizing decreases in the DNAPL/ water interfacial tension in order to prevent mobilization of DNAPL to uncontaminated regions. The surfactants are also selected to be nontoxic and biodegradable (many are U.S. Food and Drug Administration‐ (FDA‐) approved food additives). After the contaminants have been solubilized, they are pumped to the surface and treated by air stripping and other methods as in traditional pump‐and‐treat operations. CES has had extensive laboratory development and is now being field tested at three sites. The first field test is at Canadian Forces Base Borden, a military facility in Ontario, Canada. The field test involves the controlled contamination of a shallow sand aquifer with approximately 240 L of tetrachloroethylene (PCE). CES increased the contaminant concentration in the extracted water to over 10,000 ppm of PCE, compared with an aqueous solubility of 200 ppm. At latest report, more than 80% of the residual PCE has been removed. A second field test is currently in preparation at a chlorinated solvent manufacturing facility in Texas and a third at a DOE site with PCE, 1,1,1‐trichloroethane (TCA), and trichloroethylene (TCE) contamination.