Exposure of preterm neonates to toxic metals during their stay in the Neonatal Intensive Care Unit and its impact on neurodevelopment at 2 months of age.

BACKGROUND: Premature neonates might be exposed to toxic metals during their stay in the neonatal intensive care unit (NICU), which could adversely affect neurodevelopment; however, limited evidence is available. The present study was therefore designed to assess the exposure to mercury, lead, cadmium, arsenic, and manganese of preterm neonates who received total parenteral nutrition (TPN) and/or red blood cell (RBC) transfusions during their NICU stay and the risk of neurodevelopment delay at the age of 2 months. METHODS: We recruited 33 preterm neonates who required TPN during their NICU admission. Blood samples were collected for metal analysis at two different time points (admission and before discharge). Metals in the daily TPN received by preterm neonates were analyzed. Neurodevelopment was assessed using the Ages and Stages Questionnaire Edition 3 (ASQ-3). RESULTS: All samples of TPN had metal contamination: 96% exceeded the critical arsenic limit (0.3 µg/kg body weight/day); daily manganese intake from TPN for preterm neonates exceeded the recommended dose (1 µg/kg body weight) as it was added intentionally to TPN solutions, raising potential safety concerns. All samples of RBC transfusions exceeded the estimated intravenous reference dose for lead (0.19 µg/kg body weight). Levels of mercury, lead and manganese in preterm neonates at discharge decreased 0.867 µg/L (95% CI, 0.76, 0.988), 0.831 (95%CI, 0.779, 0.886) and 0.847 µg/L (95% CI, 0.775, 0.926), respectively. A decrease in ASQ-3-problem solving scores was associated with higher levels of blood lead in preterm neonates taken at admission (ß = -0.405, 95%CI = -0.655, -0.014), and with plasma manganese (ß = -0.562, 95%CI = -0.995, -0.172). We also observed an association between decreased personal social domain scores with higher blood lead levels of preterm neonates before discharge (ß = -0.537, 95%CI = -0.905, -0.045). CONCLUSION: Our findings provide evidence to suggest negative impacts on the neurodevelopment at 2 months of preterm infants exposed to certain metals, possibly related to TPN intake and/or blood transfusions received during their NICU stay. Preterm neonates may be exposed to levels of metals in utero.

Exposure of preterm neonates receiving total parenteral nutrition to phthalates and its impact on neurodevelopment at the age of 2 months.

This prospective study assessed the exposure to phthalates of preterm neonates who received total parenteral nutrition (TPN) during their stay in the neonatal intensive care unit (NICU) and the risk of neurodevelopment delays at the age of 2 months. Our study recruited 33 preterm neonates who required TPN upon NICU admission. Urine samples for analyzing phthalate metabolites were obtained at admission and then daily until the last day of receiving TPN. Phthalates in the daily TPN received by the preterm neonates were analyzed. The neurodevelopment of the neonates was assessed using the Ages and Stages Questionnaire Edition 3 (ASQ-3). Diethyl phthalate and butyl benzyl phthalate were found in all TPN samples, while 27% and 83% contained dibutyl phthalate and di-(2-ethylhexyl) phthalate (DEHP), respectively. Yet, the daily dose of each phthalate that our preterm neonates received from TPN was much lower than the recommended tolerable limit. Urinary levels of monobenzyl phthalate and four metabolites of DEHP [i.e., mono-(2-ethylhexyl) phthalate (MEHP), mono-(2-ethyl-5-hydroxyhexyl) phthalate, mono-(2-ethyl-5-oxohexyl) phthalate (MEOHP), and mono-(2-ethyl-5-carboxypentyl) phthalate (MECPP)] and the sum of four DEHP metabolites (∑4DEHP) increased significantly in preterm neonates before discharge. However, these levels were not correlated with their phthalate parent compounds in TPN, suggesting other sources of exposure in the NICU. At 2 months, we found that urinary levels of mono-iso-butyl phthalate (MiBP), MECPP, MEHP, and ∑4DEHP were inversely related to fine motor skills. After adjusting for head circumference, the inverse relationships remained significant, suggesting direct effects from phthalates. Given the extreme vulnerability of our population, it is critical to minimize exposure to phthalates during their NICU stay.

The cumulative risk assessment of phthalates exposure in preterm neonates.

Phthalates are widely used plasticizers in various consumer products and medical devices, with some reporting as having estrogenic and anti-androgenic endocrine-disrupting effects. Premature neonates may be exposed to high levels of specific phthalates during hospitalization in the neonatal intensive care unit (NICU) because of reliance on multiple medical procedures that pose a possible health risk. The present study utilized seven urinary phthalate metabolites of dibutyl phthalate isomers [(di-n-butyl phthalate (DnBP) and diisobutyl phthalate (DiBP)], butylbenzyl phthalate (BBzP), and di(2-ethylhexyl) phthalate (DEHP) that had been previously measured in 33 preterm neonates sampled at hospital admission (N = 23) and daily during their NICU stay (N = 260). We aimed to perform: (1) cumulative risk assessment (CRA) using the volume and creatinine-adjusted models; (2) examine the temporal variability of CRA from repeated measures and (3) estimate the risk of cumulative exposure to phthalates based on their anti-androgenic and/or estrogenic properties. We multiplied the relative activity of individual phthalates exhibiting estrogenic or anti-androgenic effects by daily intake. For each preterm neonate, CRA was assessed based on the hazard index (HI) metric [the sum of hazard quotients] based on three reference doses for anti-androgenicity: the tolerable daily intake (TDI) from the European Food Safety Authority, the reference dose (RfD-AA) published in 2010 and newly revised published in 2020 (NRfD-AA). The metabolites of BBzP and DEHP were 2-23 fold higher in preterm neonates during their NICU stay. Median HIs increased in the order of HINRfDAA > HIRfDAA > HITDI. In the creatinine-based model, 87% (92%), 87% (96%), and 100% (100%) of preterm neonates at admission (during NICU stay) showed HITDI, HIRfD-AA, and HINRfD-AA exceeding 1, respectively with DEHP the most prevalent. The temporal reproducibility of HI (based on three reference doses) during preterm neonate stay in the NICU was high, with intra-class correlation coefficients ranging between 0.77 and 0.97, suggesting persistent exposure to phthalates. The four phthalates that preterm neonates were exposed to in the NICU exhibited estrogenic binding and anti-androgenic effects with median values (creatinine-based) of 98.7 and 56.9 µg/kg body weight/day, respectively. This was especially true for DEHP. The results indicate that preterm neonates in this NICU setting are probably at high risk of cumulative phthalate exposure with anti-androgenic properties that may have long-term adverse reproductive and developmental effects.

A Time-Course Evaluation of DNA Damage and Neurotoxicity Induced by PEGylated Graphene Oxide Nanoparticle in Swiss Albino Mice.

PEGylated graphene oxide nanoparticle (PEG-nGO) has been commonly used as a carrier for therapeutic drugs and vaccines, because of its unique properties, such as high solubility, more stability and increased biocompatibility in physiological solutions. This study aimed to examine the DNA damage and neurotoxicity in young mice after up to 4 h of the treatment with PEG-nGO. A single dose (5 mg/kg) of intravenous injection was administered through the tail vein of adult mice. Total genomic DNA was isolated from the control and treated animals after 1 h, 2 h, and 4 h of treatments and examined for DNA damage by diphenyl assay, DNA fragmentation Assay, and FTIR (Fourier transform infrared) techniques. DNA damage studies indicated DNA fragmentation after 1 h and 2 h of treatments followed by recovery at 4 h. FTIR analysis further supported these results and showed a detailed molecular effect of the treatments that caused single and double-strand DNA breaks at 1 to 2 h after the treatments and indicated DNA damage response and recovery at 4 h. Histopathology showed neuronal apoptosis and lesions in the brain after 1 to 2 h and invasion of inflammatory response and chromatolysis after 4 h. PEG-nGO caused immediate DNA damage and cytotoxicity to the brain and its future use as a drug carrier should be considered with caution.

Essential metals, vitamins and antioxidant enzyme activities in COVID-19 patients and their potential associations with the disease severity.

The role of micronutrient deficiency in the pathogenesis of COVID-19 has been reviewed in the literature; however, the data are limited and conflicting. This study investigated the association between the status of essential metals, vitamins, and antioxidant enzyme activities in COVID-19 patients and disease severity. We recruited 155 patients, who were grouped into four classes based on the Adults guideline for the Management of Coronavirus Disease 2019 at King Faisal Specialist & Research Centre (KFSH&RC): asymptomatic (N = 16), mild (N = 49), moderate (N = 68), and severe (N = 22). We measured serum levels of copper (Cu), zinc (Zn), selenium (Se), vitamin D3, vitamin A, vitamin E, total antioxidant capacity, and superoxide dismutase (SOD). Among the patients, 30%, 25%, 37%, and 68% were deficient in Se (< 70.08 µg/L), Zn (< 0.693 µg/mL), vitamin A (< 0.343 µg/mL), and vitamin D3 (< 20.05 µg/L), respectively, and SOD activity was low. Among the patients, 28% had elevated Cu levels (> 1.401 µg/mL, KFSH&RC upper reference limit). Multiple regression analysis revealed an 18% decrease in Se levels in patients with severe symptoms, which increased to 30% after adjusting the model for inflammatory markers. Regardless of inflammation, Se was independently associated with COVID-19 severity. In contrast, a 50% increase in Cu levels was associated with disease severity only after adjusting for C-reactive protein, reflecting its possible inflammatory and pro-oxidant role in COVID-19 pathogenesis. We noted an imbalance in the ratio between Cu and Zn, with ~ 83% of patients having a Cu/Zn ratio > 1, which is an indicator of inflammation. Cu-to-Zn ratio increased to 45% in patients with mild symptoms and 34%-36% in patients with moderate symptoms compared to asymptomatic patients. These relationships were only obtained when one of the laboratory parameters (lymphocyte or monocyte) or inflammatory markers (neutrophil-to-lymphocyte ratio) was included in the regression model. These findings suggest that Cu/Zn might further exacerbate inflammation in COVID-19 patients and might be synergistically associated with disease severity. A 23% decrease in vitamin A was seen in patients with severe symptoms, which disappeared after adjusting for inflammatory markers. This finding may highlight the potential role of inflammation in mediating the relationship between COVID-19 severity and vitamin A levels. Despite our patients' low status of Zn, vitamin D3, and antioxidant enzyme (SOD), there is no evidence of their role in COVID-19 progression. Our findings reinforce that deficiency or excess of certain micronutrients plays a role in the pathogenesis of COVID-19. More studies are required to support our results.

Potential health risks of maternal phthalate exposure during the first trimester - The Saudi Early Autism and Environment Study (SEAES).

Phthalates are the most ubiquitous contaminants that we are exposed to daily due to their wide use as plasticizers in various consumer products. A few studies have suggested that in utero exposure to phthalates can disturb fetal growth and development in humans, because phthalates can interfere with endocrine function. We collected spot urine samples from 291 pregnant women in their first trimester (9.8 ± 2.3 gestational weeks) recruited in an ongoing prospective cohort study in Saudi Arabia. A second urine sample was collected within 1-7 d after enrollment. The aims of this study were to: (1) assess the extent of exposure to phthalates during the first trimester and (2) estimate the risk from single and cumulative exposures to phthalates. Most phthalate metabolites' urinary levels were high, several-fold higher than those reported in relevant studies from other countries. The highest median levels of monoethyl phthalate, mono-n-butyl phthalate (MnBP), mono-iso-butyl phthalate (MiBP), and mono-(2-ethylhexyl) phthalate (MEHP) in µg/l (µg/g creatinine) were 245.62 (197.23), 114.26 (99.45), 39.59 (34.02), and 23.51 (19.92), respectively. The MEHP levels were highest among three di (2-ethylhexyl) phthalate (DEHP) metabolites. %MEHP4, the ratio of MEHP to four di (2-ethylhexyl) phthalate metabolites (∑4DEHP), was 44%, indicating interindividual differences in metabolism and excretion. The hazard quotient (HQ) of individual phthalates estimated based on the reference dose (RfD) of the U.S. Environmental Protection Agency indicated that 58% (volume-based) and 37% (creatinine-based) of the women were at risk of exposure to ∑4DEHP (HQ > 1). Based on the tolerable daily intake (TDI) from the European Food Safety Authority, 35/12% (volume-/creatinine-based data) of the women were at risk of exposure to two dibutyl phthalate (∑DBP) metabolites (MiBP and MnBP). The cumulative risk was assessed using the hazard index (HI), the sum of HQs of all phthalates. The percentages of women (volume-/creatinine-based data) at health risks with an HI > 1 were 64/40% and 42/22% based on RfD and TDI, respectively. In view of these indices for assessing risk, our results for the anti-androgenic effects of exposing pregnant women to ∑4DEHP and ∑DBP early during pregnancy are alarming.

Effects of early and recent mercury and lead exposure on the neurodevelopment of children with elevated mercury and/or developmental delays during lactation: A follow-up study.

This follow-up study of 82 children investigated the potential impact of early and recent exposure to mercury and lead on their neurodevelopmental performance at 5-8 years of age (2017-2018). Early exposure of these children to mercury, methylmercury, and lead was assessed during lactation at 3-12 months old, as well as their mother's exposure using measurements from a cross-sectional study (2011-2013). Only infants who failed to pass the neurodevelopment screening tools and/or had elevated mercury were included in this study. Urine and hair were sampled during the follow-up study to assess the children's recent exposure to mercury, methylmercury, and lead. Their cognitive performance and visual-motor integration were also measured using the Test of Non-Verbal Intelligence (TONI) and the Beery-Visual-Motor Integration (Beery VMI), respectively. The association between alterations in urinary porphyrins excretion and exposure to metals was analyzed and their influence on the children's neurodevelopment was explored. Linear regression models revealed a significant negative association between the infants' mercury exposure during lactation and the TONI Quotient (ß = -0.298, 95%CI = -4.677, -0.414) and Beery VMI Age Equivalent scores at age 5-8 (ß = -0.437, 95%CI = -6.383, -1.844). The mothers' blood methylmercury was inversely and significantly associated with their children's TONI Quotient (ß = -0.231, 95%CI = -8.184, -0.331). In contrast, the children's Beery VMI Age Equivalent scores were positively and significantly associated with the hair methylmercury of the mothers (ß = 0.214, 95%CI = 0.088, 3.899) and their infants (ß = 0.256, 95%CI = 0.396, 4.488). These relationships suggest the presence of negative confounding that we did not take into account. Unlike mercury, there was some evidence that lead in breast milk had an inverse relationship with the children's visual-motor coordination skills. Our study did not show a clear association between children's recent exposure to metals and neurodevelopment. However, a significant inverse association was observed between the TONI Quotient and the interaction of hair methylmercury × ∑porphyrins (ß = -0.224, 95%CI = -0.86, -0.049), implying that porphyrins are a sensitive measure of low body-mercury burden. Although lead induced higher ∑porphyrins excretion in urine (ß = 0.347, 95%CI = 0.107, 0.525), their interaction did not influence children's neurodevelopmental scores. The interactions between metals and porphyrins might provide insights into their potential contributory role in the pathogenesis associated with neurological disorders or other diseases. Despite the small sample size of the present study, its findings about the association between toxic metal exposure and the high risk of poor neurodevelopmental performance are worrying, particularly at an early age, and additional research is needed using larger sample sizes.