Consequences of Gestational Malaria on Birth Weight: Finding the Best Timeframe for Intermittent Preventive Treatment Administration

To investigate the consequences of intermittent preventive treatment (IPTp) timing on birth weight, we pooled data from two studies conducted in Benin between 2005 and 2010: a prospective cohort of 1037 pregnant women and a randomised trial comparing sulfadoxine-pyrimethamine (SP) to mefloquine in 1601 women. A total of 1439 women (752 in the cohort and 687 in the SP arm of the randomised trial) who delivered live singletons were analysed. We showed that an early intake of the first SP dose (4 months of gestation) was associated with a lower risk of LBW compared to a late intake (6–7 months of gestation) (aOR = 0.5 p = 0.01). We also found a borderline increased risk of placental infection when the first SP dose was administered early in pregnancy (aOR = 1.7 p = 0.1). This study is the first to investigate the timing of SP administration during pregnancy. We clearly demonstrated that women who had an early intake of the first SP dose were less at risk of LBW compared to those who had a late intake. Pregnant women should be encouraged to attend antenatal visits early to get their first SP dose and a third dose of SP could be recommended to cover the whole duration of pregnancy and to avoid late infections of the placenta

Analysis of IgG with specificity for variant surface antigens expressed by placental Plasmodium falciparum isolates

BACKGROUND: Pregnancy-associated malaria (PAM) is caused by Plasmodium falciparum-infected erythrocytes that can sequester in placental intervillous space by expressing particular variant surface antigens (VSA) that can mediate adhesion to chondroitin sulfate A (CSA) in vitro. IgG antibodies with specificity for the VSA expressed by these parasites (VSA(PAM)) are associated with protection from maternal anaemia, prematurity and low birth weight, which is the greatest risk factor for death in the first month of life. METHODS: In this study, the development of anti-VSA(PAM )antibodies in a group of 151 women who presented to the maternity ward of Albert Schweitzer Hospital in Lambaréné, Gabon for delivery was analysed using flow cytometry assays. Plasma samples from placenta infected primiparous women were also investigated for their capacity to inhibit parasite binding to CSA in vitro. RESULTS: In the study cohort, primiparous as well as secundiparous women had the greatest risk of infection at delivery as well as during pregnancy. Primiparous women with infected placentas at delivery showed higher levels of VSA(PAM)-specific IgG compared to women who had no malaria infections at delivery. Placental isolates of Gabonese and Senegalese origin tested on plasma samples from Gabon showed parity dependency and gender specificity patterns. There was a significant correlation of plasma reactivity as measured by flow cytometry between different placental isolates. In the plasma of infected primiparous women, VSA(PAM)-specific IgG measured by flow cytometry could be correlated with anti-adhesion antibodies measured by the inhibition of CSA binding. CONCLUSION: Recognition of placental parasites shows a parity- and sex- dependent pattern, like that previously observed in laboratory strains selected to bind to CSA. Placental infections at delivery in primiparous women appear to be sufficient to induce functional antibodies which can both recognize the surface of the infected erythrocytes as well as block their binding to CSA. The correlation between serum reactivities of placental field isolates from different geographic locations and collected at different times is indicative of the conserved nature of the antigen(s) mediating PAM

Cellular immune response to Plasmodium falciparum after pregnancy is related to previous placental infection and parity

BACKGROUND: Malaria in pregnancy is characterised by the sequestration of Plasmodium falciparum-infected erythrocytes in placental intervillous spaces. Placental parasites express a specific phenotype, which allows them to cytoadhere to chondroitin sulfate A expressed by syncytiotrophoblasts. Malaria infection during pregnancy allows the acquisition of antibodies against placental parasites, these antibodies are thought to be involved in protection during subsequent pregnancies. METHODS: To investigate the development of a cellular response to placental parasites during pregnancy, peripheral blood mononuclear cells were collected from women at the time of their confinement. The study was performed in Cameroon where malaria transmission is perennial. In vitro cell proliferation and cytokine production were measured in response to non-malarial activators (concanavalin A and PPD), a recombinant protein from P. falciparum MSP-1, and erythrocytes infected by two P. falciparum lines, RP5 and W2. Like placental parasites, the RP5 line, but not W2, adheres to chondroitin sulfate A and to syncytiotrophoblasts. RESULTS: The proliferative response to all antigens was lower for cells obtained at delivery than 3 months later. Most interestingly, the cellular response to the RP5 line of P. falciparum was closely related to parity. The prevalence rate and the levels of response gradually increased with the number of previous pregnancies. No such relationship was observed with W2 line, or MSP-1 antigen. CONCLUSIONS: This suggests the occurrence of an immune response more specific for the RP5 line in women having had multiple pregnancies, and who are likely to develop immunity to pregnancy-associated parasites. Both humoral and cellular mechanisms may account for the lower susceptibility of multigravidae to malaria

Infections with Plasmodium falciparum during pregnancy affect VAR2CSA DBL-5 domain-specific T cell cytokine responses

Background: Current knowledge of human immunological responses to pregnancy-associated malaria-specific Plasmodium falciparum protein VAR2CSA concerns almost exclusively B cell-driven antibody-mediated activity. Knowledge of VAR2CSA-specific T cell-mediated activity is minimal by comparison, with only a single published report of a study investigating VAR2CSA-derived peptide-specific T cell responses. The study described here represents an attempt to redress this balance. Methods: Within the framework of a cohort study of 1037 pregnant Beninese, sub-groups were selected on the basis of the documented presence/absence of infection with P. falciparum and conducted detailed immunological assessments both at inclusion into the study and at delivery. Peripheral blood mononuclear cells were isolated, stimulated in vitro, and VAR2CSA DBL-5 domain-specific, IFN-gamma-secreting T-cell frequencies and cytokine responses were quantified using flow cytometric techniques. Multivariate analyses were used to determine primarily whether the T cell-mediated DBL5-specific activity measured was associated with infection by P. falciparum adjusted for gravidity, anaemia and other cofactors. Results: Infections with P. falciparum detected at inclusion were associated with enhanced non-specific TNF responses, whilst diminished non-specific and DBL-5-specific IL-10 responses were associated with infections detected at delivery. Infections during pregnancy led to enhanced non-specific and DBL-5-specific IFN-gamma responses detectable at delivery but to concomitantly lower DBL-5-specific CD8+ IFN-gamma responses. Prospective assessments indicated that non-specific pro-inflammatory responses detectable at inclusion in the study were associated with the occurrence of infections subsequently during pregnancy. Conclusions: The findings represent a first step in elucidating the quantity and quality of cellular immunological responses to VAR2CSA, which will help in the development of the primary vaccine candidate for prevention of pregnancy-associated malaria

Findings of the Survey on Prevention of Plagiarism in Lithuanian Research Journals

AbstractAt the end of 2011, the Association of Lithuanian Serials initiated a survey, which aimed to ascertain whether Lithuanian journal editors, reviewers and authors encountered plagiarism, self-plagiarism and how they understood originality of a paper. Additionally, the survey looked at methods used for plagiarism prevention by editors and reviewers as well as ways, in which editors managed issues related to plagiarism. The survey suggests that no unanimous decision exists regarding the originality of a manuscript and that editors expect reviewers to identify plagiarism with little use of technologies. While answering to survey questions, respondents provided numerous comments. This demonstrates that plagiarism is a burning issue and scientific misconduct policy is needed in Lithuania. The survey was conducted during the period when the Lithuanian Research Council initiated the procedure for establishing the Ombudsman position. The Lithuanian Research Council funded several projects in 2012 and 2013, the aim of which was to familiarise the Lithuanian academic community with plagiarism prevention technologies and ethical aspects in academic publishing. The projects administrated by the Association of Lithuanian Serials provide research journal publishers and researchers related to journal publishing with a possibility of using CrossCheck system and discussing editorial policies

Impact of the use and efficacy of long lasting insecticidal net on malaria infection during the first trimester of pregnancy - a pre-conceptional cohort study in southern Benin.

BACKGROUND: Malaria in pregnancy is prevalent in Sub-Saharan Africa. The first trimester of pregnancy is a critical period and the best preventive measure is Long Lasting Insecticidal Nets (LLIN). Unfortunately, few studies have been conducted which focuses on the usage and efficacy of LLIN on malaria prevention during the first trimester. METHODS: We assessed the use and effectiveness of LLIN in early pregnancy in Benin and its impact on malaria infection risk. We followed-up a cohort of 240 pregnant women from pre-conception to the end of the first trimester of pregnancy in Southern Benin. Parasitological, maternal and LLIN data were actively collected before, at the beginning and end of the first trimester of pregnancy. A Cox regression model was used to determine the relationship between the time to onset of the first malaria infection and the use, physical integrity, and bio-efficacy of the LLIN, adjusted for relevant covariables. RESULTS: The good use, good physical integrity and biological efficacy of LLIN were associated with a decreased risk of occurrence of the first malaria infection in early pregnancy (HRa = 0.38; (0.18-0.80); p < 0.001; HRa = 0.59; (0.29-1.19); p < 0.07; HRa = 0.97; (0.94-1.00); p < 0.04 respectively), after adjustment for other covariates. Primi/secundigravidity and malaria infection before pregnancy were associated with a risk of earlier onset of malaria infection. CONCLUSION: The classically used LLIN's indicators of possession and use may not be sufficient to characterize the true protection of pregnant women in the first trimester of pregnancy. Indicators of physical integrity and bio-efficacy should be integrated with those indicators in evaluation studies

Dynamics of Submicroscopic Plasmodium falciparum Infections Throughout Pregnancy: A Preconception Cohort Study in Benin.

BACKGROUND: In the context of global malaria elimination efforts, special attention is being paid to submicroscopic Plasmodium falciparum infections. In pregnant, sub-Saharan African women, such infections are more prevalent than microscopic infections, and are thought to have adverse effects on both mothers' and newborns' health. However, no study has studied the dynamics and determinants of these infections throughout pregnancy. Retard de Croissance Intra-uterin et Paludisme (RECIPAL), a preconception cohort study carried out in Benin between 2014 and 2017, represented a unique opportunity to assess this issue. METHODS: We used data from 273 pregnant Beninese women who were followed-up from preconception to delivery. We studied the dynamics of and factors influencing submicroscopic (and microscopic) P. falciparum infections during the 3 trimesters of pregnancy, using an ordinal logistic mixed model. RESULTS: The incidence rate of submicroscopic P. falciparum infections during pregnancy was 12.7 per 100 person-months (95% confidence interval [CI] 10.8-14.9), compared to 6.7 per 100 person-months (95% CI 5.5-8.1) for microscopic infections. The prevalences were highest in the first trimester for both submicroscopic and microscopic infections. After adjustment for potential confounding factors, we found that those of young age and those with a submicroscopic P. falciparum infection prior to pregnancy were at significantly higher risks of submicroscopic and microscopic infections throughout pregnancy, with a more pronounced effect in the first trimester of pregnancy. CONCLUSIONS: The first trimester of pregnancy is a particularly high-risk period for P. falciparum infection during pregnancy, especially for the youngest women. Malaria prevention tools covering the preconception period and early pregnancy are urgently needed to better protect pregnant women and their newborns

A Genotyping Study in Benin Comparing the Carriage of Plasmodium falciparum Infections Before Pregnancy and in Early Pregnancy: Story of a Persistent Infection

BACKGROUND: Malaria infections in the first trimester of pregnancy are frequent and deleterious for both mother and child health. To investigate if these early infections are newly acquired or already present in the host, we assessed whether parasites detected before pregnancy and those detected in early pregnancy are the same infection. METHODS: We used data from the preconceptional "RECIPAL" study (Benin, 2014-2017). Sixty-three pregnant women of 411 included who had a malaria infection detected by quantitative polymerase chain reaction both before pregnancy and at the first antenatal care (ANC) visit were selected for this study. Two highly polymorphic markers, msp-2 and glurp, and a fragment-analysis method were used to enumerate the Plasmodium falciparum genotypes and to quantify their proportions within isolates. An infection was considered as persistent when identical msp-2 and glurp genotypes were found in the corresponding prepregnancy and early-pregnancy samples. RESULTS: The median time between the 2 malaria screenings was 3 months. The median gestational age at the first ANC visit was 6.4 weeks. Most infections before pregnancy were submicroscopic infections. Based on both msp-2 and glurp genotyping, the infection was similar before and in early pregnancy in 46% (29/63) of cases. CONCLUSIONS: Almost half of P. falciparum infections detected in the first trimester originate before pregnancy. Protecting young women from malaria infection before pregnancy might reduce the prevalence of malaria in early pregnancy and its related poor maternal and birth outcomes.Impact du paludisme précoce au cours de la grossesse sur la croissance fœtale au Béni

Семантичні зміни в лексичному складі російської та української мов

Использование вычислительной техники и радиоэлектроники способствовало формированию специальной группы лексических единиц. Номинация новых явлений и понятий является актуальной проблемой нынешнего этапа развития языка. Изменение семантического наполнения – это один из способов решения данной проблемы. Расширение или сужение семантического объема слов способствует обогащению лексической системы, а именно терминологии.Використання обчислювальної техніки та радіоелектроніки спричинило формування спеціальної групи лексичних одиниць. Номінація нових явищ та понять є актуальною проблемою теперішнього етапу розвитку мови. Зміна семантичного об'єму – це один із засобів вирішення даної проблеми. Звуження або розширення семантичного наповнення сприяє збагаченню лексичної системи, а саме термінології.Using of radio-electronic devices forced the formation of a special group of lexical units. The nomination of new processes and notions is an actual problem of today's language development. Semantic changes of existing units is one of the decisions of the problem. Widening and narrowing of semantic meanings promotes the enrichment of lexical system, especially the system of terminology