Nanomaterials in the Environment Acquire an "Eco-Corona" Impacting their Toxicity to Daphnia Magna-a Call for Updating Toxicity Testing Policies.

Nanomaterials (NMs) are particles with at least one dimension between 1 and 100 nm and a large surface area to volume ratio, providing them with exceptional qualities that are exploited in a variety of industrial fields. Deposition of NMs into environmental waters during or after use leads to the adsorption of an ecological (eco-) corona, whereby a layer of natural biomolecules coats the NM changing its stability, identity and ultimately toxicity. The eco-corona is not currently incorporated into ecotoxicity tests, although it has been shown to alter the interactions of NMs with organisms such as Daphnia magna (D. magna). Here, the literature on environmental biomolecule interactions with NMs is synthesized and a framework for understanding the eco-corona composition and its role in modulating NMs ecotoxicity is presented, utilizing D. magna as a model. The importance of including biomolecules as part of the current international efforts to update the standard testing protocols for NMs, is highlighted. Facilitating the formation of an eco-corona prior to NMs ecotoxicity testing will ensure that signaling pathways perturbed by the NMs are real rather than being associated with the damage arising from reactive NM surfaces "acquiring" a corona by pulling biomolecules from the organism's surface.

Experiences with peer support for breastfeeding in Beirut, Lebanon: A qualitative study.

BACKGROUND: Despite the beneficial effects of peer support on breastfeeding, research on the process of peer support is scarce. In Lebanon, exclusive breastfeeding is only 15% in infants below six months. A multidisciplinary team launched a multi-component breastfeeding support intervention, with peer support, and professional lactation support provided by International Board Certified Lactation Consultants (IBCLs) to target this decline. AIM: To describe the experiences of breastfeeding mothers and peer support providers with the process of breastfeeding support, and the influence of the intervention on their social support system. METHODS: Using a qualitative methodology, a purposive sample of breastfeeding and support mothers was accessed from among those who completed their six months interview in the trial taking place in two hospitals in Beirut, Lebanon. Data were collected from 43 participants using in-depth interviews and following the data saturation principle. All interviews were audio recorded and transcribed verbatim. Thematic analysis was conducted, guided by the principles of grounded theory. RESULTS: Breastfeeding mothers were satisfied with their breastfeeding experience, and extremely appreciative of the support provided by their peers and the IBCLCs. They experienced these forms of support differently. Peer support was perceived to be important in encouraging breastfeeding continuation, whereas IBCLC support was influential in problem solving. CONCLUSION: These findings can improve our understanding of the peer and professional lactation support process within the social context, and the realities of breastfeeding mothers, and help facilitate the scaling up of interventions in similar contexts.

The psychometric properties of the Ages and Stages Questionnaires-3 in Arabic: Cross-sectional observational study.

BACKGROUND: Screening for developmental delay is recommended for pediatricians, yet validated screening tools in Arabic are scarce. AIMS: Assess the reliability, validity, sensitivity and specificity of the Arabic ASQ-3 in detecting developmental delays in children aged 4-33 months. STUDY DESIGN: Cross-sectional observational study. SUBJECTS: A sample of 491 children from all Lebanese governorates from five age groups (4, 10, 18, 27 and 33 months). OUTCOME MEASURES: Internal consistency using Cronbach's alpha (Cα), convergent construct validity using Pearson Correlation Coefficient (CC) comparing ASQ-3 in Arabic (A-ASQ-3) to Bayley scale for infant development (BSID-III) scores were computed. A subset sample (n = 35) underwent assessment with BSID-III for convergent validity, and sensitivity and specificity. A-ASQ-3 scores were compared to the US mean cutoff scores. RESULTS: Subjects' mean age was 17.75 ±â€¯10.6 months. Cα was 0.85; Pearson CC showed positive moderate correlation between A-ASQ-3 gross and fine motor scores and BSID-III composite motor scores (r = 0.42, p = 0.002; r = 0.39, p = 0.004, respectively); and positive moderate correlation between A-ASQ-3 problem solving and BSID-III cognitive scores (r = 0.43, p = 0.001). A-ASQ-3 had 100% sensitivity and 50% specificity for cognitive scores; 60% sensitivity and 70% specificity for motor scores. CONCLUSION: A-ASQ-3 has adequate reliability and validity for the tested age groups. It is plausible that this would hold true for the rest of the questionnaires. Further testing is needed to make the five clusters more aligned with the US sample scores and to improve the sensitivity and specificity.

A multi-component intervention to support breastfeeding in Lebanon: A randomized clinical trial.

BACKGROUND: Effective evidence-based breastfeeding support interventions can bolster breastfeeding practices. This study investigated the effect of a multi-component breastfeeding support intervention delivered in hospital and home settings on six-month exclusive breastfeeding (EBF) relative to standard care. METHODS: This is a parallel group, randomized clinical trial, in which 362 healthy pregnant women with singleton pregnancy were randomly allocated to a multi-component intervention that included antenatal breastfeeding education, professional, and peer support, delivered in hospital and home settings for six months (experimental, n = 174), or to standard care (control, n = 188). The primary outcome was six-month EBF rate. Secondary outcomes were exclusive and any breastfeeding rates at one and three months, maternal breastfeeding knowledge, attitude, and behavior at six months, and satisfaction with the intervention. RESULTS: The crude six-month EBF rate was similar in both groups (35.2% vs. 28.1% in the experimental and control groups, respectively, p = 0·16). In adjusted analysis, six-month exclusivity was twice as likely in the experimental group relative to standard care (OR = 2.02; 95%CI: 1.20 to 3.39); whereas the odds for any breastfeeding were similar. Participants compliant with all three components were six times more likely to practice EBF for six months relative to standard care (OR = 6.63; 95% CI: 3.03 to 14.51). Breastfeeding knowledge of the experimental group, at six months, was significantly improved compared to the control. No changes were observed in breastfeeding attitude or behavior. CONCLUSIONS: Combining education with peer and professional breastfeeding support improved six-month breastfeeding exclusivity and knowledge.

Metabolomic method to detect a metabolite corona on amino-functionalized polystyrene nanoparticles.

Protein coronas on nanoparticles (NPs) affect their physicochemical properties, cellular uptake, and toxicity, and have been described extensively. To date, studies of the occurrence of small molecule (metabolite) coronas are limited. We sought to determine whether a metabolite corona forms on NPs, using high-sensitivity metabolomics combined with a model system for freshwater ecotoxicology (Daphnia magna feeding on Chlorella vulgaris). Using amino-functionalized polystyrene NPs (NH2-pNPs), we showed the impact of this material on Daphnia feeding to provide a rationale for the detailed molecular investigations. We then employed a targeted LC-MS/MS approach for sodium dodecyl sulfate (SDS) as an analog to signaling molecules known to occur in our freshwater model system and optimized a corona extraction method for this representative metabolite. Next, we performed an untargeted discovery-based metabolomics study - using high-sensitivity nanoelectrospray direct infusion mass spectrometry (DIMS) - to enable an unbiased assessment of the metabolite corona of NH2-pNPs in the freshwater model system. Our results demonstrate that SDS was successfully recovered from NH2-pNPs, confirming that the extraction protocol was fit-for-purpose. Untargeted DIMS metabolomics reproducibly detected 100 s of small molecule peaks extracted from NH2-pNPs exposed to conditioned media from the D. magna-C. vulgaris model system. Attempts to annotate these extracted metabolites, including by using van Krevelen and Kendrick Mass Defect plots, indicate a diverse range of metabolites that were not clustered into any particular class. Overall we demonstrate the existence of an ecologically relevant metabolite corona on the surface of NPs through application of a high-sensitivity, untargeted mass spectrometry metabolomics workflow.

Adaptation and Validation of the Arabic Version of the Infant Breastfeeding Knowledge Questionnaire among Lebanese Women.

BACKGROUND: Valid instruments that can reliably assess maternal breastfeeding knowledge in Arabic-speaking populations are nonexistent. The availability of such an instrument is essential for investigators working in this field. OBJECTIVE: This study aimed to describe the adaptation and validation of the Arabic Breastfeeding Knowledge Questionnaire (BFK-A) from the original 20-item English version. METHODS: A translated version of the 20-item BFK was validated among 417 Lebanese women after pilot testing for clarity, comprehension, length, and cultural appropriateness. Exploratory factor analysis was run to examine dimensionality of the instrument and Kuder-Richardson-20 (KR-20) was used to assess its internal consistency. RESULTS: The BFK-A is a unidimensional scale with acceptable internal consistency reliability (KR-20 = 0.652) after the exclusion of 4 items. Higher breastfeeding knowledge levels were strongly and statistically significantly associated with higher mean scores for the validated Arabic Iowa Infant Feeding Attitude Scale ( P < .001), thus confirming its construct validity. CONCLUSION: The Arabic 16-item BFK-A has an acceptable reliability, similar to the original instrument. Further studies are encouraged to confirm the validity of the 16-item BFK-A among other Arab populations. There is also a need to develop more reliable instruments to use in lactation research in this context.

Secreted protein eco-corona mediates uptake and impacts of polystyrene nanoparticles on Daphnia magna.

Nanoparticles (NPs) are defined as having at least one external dimension between 1 and 100 nm. Due to their small size, NPs have a large surface area to volume ratio giving them unique characteristics that differ from bulk material of the same chemical composition. As a result these novel materials have found numerous applications in medical and industrial fields with the result that environmental exposure to NPs is increasingly likely. Similarly, increased reliance on plastic, which degrades extremely slowly in the environment, is resulting in increased accumulation of micro-/nano-plastics in fresh and marine waters, whose ecotoxicological impacts are as yet poorly understood. Although NPs are well known to adsorb macromolecules from their environment, forming a biomolecule corona which changes the NP identity and how it interacts with organisms, significantly less research has been performed on the ecological corona (eco-corona). Secretion of biomolecules is a well established predator-prey response in aquatic food chains, raising the question of whether NPs interact with secreted proteins, and the impact of such interaction on NP uptake and ecotoxicity. We report here initial studies, including optimisation of protocols using carboxylic-acid and amino modified spherical polystyrene NPs, to assess interaction of NPs with biomolecules secreted by Daphnia magna and the impact of these interactions on NP uptake, retention and toxicity towards Daphnia magna. BIOLOGICAL SIGNIFICANCE: Daphnia magna are an important environmental indicator species who may be especially sensitive to nanoparticles (NPs) as a result of being filter-feeders. This paper demonstrates for the first time that proteins released by Daphnia magna create an eco-corona around polystyrene NPs which causes heightened uptake of the NPs and consequently increases toxicity. The secreted protein eco-corona also causes the NPs to be less efficiently removed from the gut of D. magna and NPs remaining in the gut of D. magna affected the rate of subsequent feeding. Thus, fate of NPs in the environment should be evaluated and monitored under more realistic exposure scenarios.

Shape and Charge of Gold Nanomaterials Influence Survivorship, Oxidative Stress and Moulting of Daphnia magna.

Engineered nanomaterials (ENMs) are materials with at least one dimension between 1-100 nm. The small size of ENMs results in a large surface area to volume ratio, giving ENMs novel characteristics that are not traditionally exhibited by larger bulk materials. Coupled with large surface area is an enormous capacity for surface functionalization of ENMs, e.g., with different ligands or surface changes, leading to an almost infinite array of variability of ENMs. Here we explore the effects of various shaped (spheres, rods) and charged (negative, positive) gold ENMs on Daphnia magna (D. magna) in terms of survival, ENM uptake and production of reactive oxygen species (ROS), a key factor in oxidative stress responses. We also investigate the effects of gold ENMs binding to the carapace of D. magna and how this may induce moulting inhibition in addition to toxicity and stress. The findings suggest that ENM shape and surface charge play an important role in determining ENM uptake and toxicity.

Carbon nanotube compared with carbon black: effects on bacterial survival against grazing by ciliates and antimicrobial treatments.

The ingestion and digestion of Escherichia coli by the ciliated protozoan, Tetrahymena thermophila, was investigated after an initial exposure to either water-soluble single-walled carbon nanotubes (SWNT) or to carbon black (CB). Both SWNT and CB were internalised and visible in food vacuoles of ciliates. When presented with E. coli expressing green-fluorescent protein (GFP), these ciliates internalised bacteria as well. However, ciliates that had first internalised SWNT but not CB subsequently externalised or egested vesicle-like structures with fluorescent bacteria inside. These egested bacteria were viable and less susceptible than planktonic E. coli to killing either by the antibiotic, chloramphenicol or the disinfectant, glutaraldehyde. These results suggest that SWNT can alter the intracellular trafficking of vesicles within ciliates, leading to bacterial prey being packaged externally and protected for a time from environmental killing, which could have implications for sewage treatment and for public health.

A putatively functional haplotype in the gene encoding transforming growth factor beta-1 as a potential biomarker for radiosensitivity.

PURPOSE: To determine whether genetic variability in TGFB1 is related to circulating transforming growth factor-ß1 (TGF-ß1) plasma concentrations after radiotherapy and to radiosensitivity of lymphoid cells. PATIENTS AND METHODS: Transforming growth factor-ß1 plasma concentrations (n=79) were measured in patients 1 year after radiotherapy and chromosomal aberrations (n=71) ex vivo before therapy start. Furthermore, TGF-ß1 secretion and apoptosis were measured in isolated peripheral blood mononuclear cells of 55 healthy volunteers. These phenotypes were analyzed in relation to five germline polymorphisms in the 5' region of the TGFB1 gene. Because of high linkage disequilibrium, these five polymorphisms reflect frequent genetic variation in this region. A presumed impact of TGF-ß1 on DNA damage or repair was measured as micronucleus formation in 30 lymphoblastoid cell lines. RESULTS: We identified a hypofunctional genetic haplotype termed H3 tagging the 5' region of the TGFB1 gene encoding TGF-ß1. H3 was associated with lower TGF-ß1 plasma concentrations in patients (p=0.01) and reduced TGF-ß1 secretion in irradiated peripheral blood mononuclear cells (p=0.003). Furthermore, cells with H3 were less prone to induction of chromosomal aberrations (p=0.001) and apoptosis (p=0.003) by irradiation. The hypothesis that high TGF-ß1 could sensitize cells to DNA damage was further supported by increased micronuclei formation in 30 lymphoblastoid cell lines when preincubated with TGF-ß1 before irradiation (p=0.04). CONCLUSIONS: On the basis of TGF-ß1 plasma levels and radiation sensitivity of lymphoid cells, this study revealed a putatively hypofunctional TGFB1 haplotype. The significance of this haplotype and the suggested link between TGF-ß1 function and DNA integrity should be further explored in other cell types, as well as other experimental and clinical conditions.