Incidence of congenital toxoplasmosis among infants born to HIV-coinfected mothers: case series and literature review

Introduction:There is a paucity of data on the occurrence of congenital toxoplasmosis in children born to mothers dually infected with HIV and Toxoplasma gondii.Objective:To evaluate aspects of the mother–infant pairs associated with vertical transmission of toxoplasmosis in women co-infected with HIV in a referral center for perinatally acquired infections in Belo Horizonte, Brazil.Methods:Descriptive study of HIV vertically exposed children, with congenital toxoplasmosis, followed at a referral center (cohort/Belo Horizonte). Prenatal and post-natal variables for the mother–infant pairs were evaluated. A literature review with no filtering for time and language was performed to identify reports of congenital toxoplasmosis in HIV vertically exposed children.Results:Among 2007 HIV vertically exposed children evaluated in the period from 1998 to 2011, 10 cases of congenital toxoplasmosis were identified (incidence: 0.5%, 95% confidence interval: 0.24–0.91). In searching the literature 22 additional cases in 17 reports were found. Combining the findings of our cohort with other reported cases, 50% (16/32) of congenital toxoplasmosis in HIV vertically exposed children were from Brazil. The cases of congenital toxoplasmosis in HIV vertically exposed children identified in Brazil occurred mainly in the post-Highly Active Antiretroviral Therapy era (p = 0.002) and presented a lower death rate (p = 0.003) than those from other countries. In the cohort/Belo Horizonte, HIV infection was identified mainly during gestation; T. gondii vertical transmission was observed in pregnant women with CD4+>500 cells/mm3 and latent toxoplasmosis. High rates of ocular lesions (87.5%) and central nervous system involvement (70%) were detected.Conclusions:The risk of vertical transmission of T. gondii in HIV-infected women is low and has been usually associated with maternal immunosuppression and elevated viral load. However, our findings of congenital toxoplasmosis in children born to HIV-infected mothers with latent toxoplasmosis and not immunosuppressed emphasize the need for careful follow-up in these cases

Sugar metabolism and developmental stages of rubber tree (Hevea brasiliensis L.) seeds

Changes in the concentration of sugars and sucrose metabolism enzymes can characterize the developmental stages of a seed. In recalcitrant species such as Hevea brasiliensis L., little is known about these changes. We aimed to evaluate the three main stages of development of rubber tree seeds – histodifferentiation, cell elongation and accumulation of reserves. The activities of acid and neutral invertases (E.C. 3.2.1.26) and sucrose synthase (EC 2.4.1.13), and the concentrations of reducing sugars (RS), total soluble sugars (TSS) and sucrose (Suc) were determined concomitantly with the histochemical and anatomical evaluation of seed structure. Histodifferentiation in rubber tree seeds occurs up to 75 days after anthesis (DAA). The concentration of RS is high and of Suc is low during seed histodifferentiation, which occurs along with a visible increase in the number of cell divisions. After that period, there is an increase in the concentration of Suc (mg g−1) and in the number and size of starch granules, and a decrease in the concentration of RS (mg g−1). At that point, cell elongation occurs. At 135 DAA, there is an inversion in the concentration of these two sugars and an increase in reserve accumulation. Thus, in seeds of the evaluated clone, the period up to 75 DAA is characterized as the histodifferentiation stage, while from that time up to 120 DAA the cell elongation stage takes place. The final stage of seed maturation and reserve accumulation begins at 135 DAA, and the seed, including the embryo, is completely formed at 175 DAA