Bioactive metabolites of OMEGA-6 and OMEGA-3 fatty acids are associated with inflammatory cytokine concentrations in maternal and infant plasma at the time of delivery

BACKGROUND & AIMS

Inflammation is necessary for a healthy pregnancy. However, unregulated or excessive inflammation during pregnancy is associated with severe maternal and infant morbidities, such as pre-eclampsia, abnormal infant neurodevelopment, or preterm birth. Inflammation is regulated in part by the bioactive metabolites of omega-6 (n-6) and omega-3 (n-3) fatty acids (FAs). N-6 FAs have been shown to promote pro-inflammatory cytokine environments in adults, while n-3 FAs have been shown to contribute to the resolution of inflammation; however, how these metabolites affect maternal and infant inflammation is still uncertain. The objective of this study was to predict the influence of n-6 and n-3 FA metabolites on inflammatory biomarkers in maternal and umbilical cord plasma at the time of delivery.

METHODS

Inflammatory biomarkers (IL-1β, IL-2, IL-6, IL-8, IL-10, and TNFα) for maternal and umbilical cord plasma samples in 39 maternal-infant dyads were analyzed via multi-analyte bead array. Metabolites of n-6 FAs (arachidonic acid and linoleic acid) and n-3 FAs (eicosapentaenoic acid and docosahexaenoic acid) were assayed via liquid chromatography-mass spectrometry. Linear regression models assessed relationships between maternal and infant inflammatory markers and metabolite plasma concentrations.

RESULTS

Increased plasma concentrations of maternal n-6 metabolites were predictive of elevated pro-inflammatory cytokine concentrations in mothers; similarly, higher plasma concentrations of umbilical cord n-6 FA metabolites were predictive of elevated pro-inflammatory cytokine concentrations in infants. Higher plasma concentrations of maternal n-6 FA metabolites were also predictive of elevated pro-inflammatory cytokines in infants, suggesting that maternal n-6 FA status has an intergenerational impact on the inflammatory status of the infant. In contrast, maternal and cord plasma concentrations of n-3 FA metabolites had a mixed effect on inflammatory status in mothers and infants, which may be due to the inadequate maternal dietary intake of n-3 FAs in our study population.

CONCLUSIONS

Our results reveal that maternal FA status may have an intergenerational impact on the inflammatory status of the infant. Additional research is needed to identify how dietary interventions that modify maternal FA intake prior to or during pregnancy may impact maternal and infant inflammatory status and associated long-term health outcomes.

The impact of iron supplementation on the preterm neonatal gut microbiome: A pilot study

OBJECTIVE

The gastrointestinal microbiome in preterm infants exhibits significant influence on optimal outcomes-with dysbiosis shown to substantially increase the risk of the life-threatening necrotizing enterocolitis. Iron is a vital nutrient especially during the perinatal window of rapid hemoglobin production, tissue growth, and foundational neurodevelopment. However, excess colonic iron exhibits potent oxidation capacity and alters the gut microbiome-potentially facilitating the proliferation of pathological bacterial strains. Breastfed preterm infants routinely receive iron supplementation starting 14 days after delivery and are highly vulnerable to morbidities associated with gastrointestinal dysbiosis. Therefore, we set out to determine if routine iron supplementation alters the preterm gut microbiome.

METHODS

After IRB approval, we collected stool specimens from 14 infants born <34 weeks gestation in the first, second, and fourth week of life to assess gut microbiome composition via 16S rRNA sequencing.

RESULTS

We observed no significant differences in either phyla or key genera relative abundance between pre- and post-iron timepoints. We observed notable shifts in infant microbiome composition based on season of delivery.

CONCLUSION

Though no obvious indication of iron-induced dysbiosis was observed in this unique study in the setting of prematurity, further investigation in a larger sample is warranted to fully understand iron's impact on the gastrointestinal milieu.

Omega-3 Polyunsaturated Fatty Acid Levels in Maternal and Cord Plasma Are Associated with Maternal Socioeconomic Status

Omega-3 (n-3) polyunsaturated fatty acids (PUFAs) play a crucial role in fetal growth and neurodevelopment, while omega-6 (n-6) PUFAs have been associated with adverse pregnancy outcomes. Previous studies have demonstrated that socioeconomic status (SES) influences dietary intake of n-3 and n-6 PUFAs, but few studies have evaluated the association between maternal and cord plasma biomarkers of PUFAs and socioeconomic markers. An IRB-approved study enrolled mother-infant pairs (n = 55) at the time of delivery. Maternal and cord plasma PUFA concentrations were analyzed using gas chromatography. Markers of SES were obtained from validated surveys and maternal medical records. Mann-Whitney U tests and linear regression models were utilized for statistical analysis. Maternal eicosapentaenoic acid (EPA) (p = 0.02), cord EPA (p = 0.04), and total cord n-3 PUFA concentrations (p = 0.04) were significantly higher in college-educated mothers vs. mothers with less than a college education after adjustment for relevant confounders. Insurance type and household income were not significantly associated with n-3 or n-6 PUFA plasma concentrations after adjustment. Our findings suggest that mothers with lower educational status may be at risk of lower plasma concentrations of n-3 PUFAs at delivery, which could confer increased susceptibility to adverse pregnancy and birth outcomes.

Evaluation of Vitamin E Isoforms in Placental Tissue and Their Relationship with Maternal Dietary Intake and Plasma Concentrations in Mother-Infant Dyads

α-tocopherol is a vitamin E isoform with potent antioxidant activity, while the γ-tocopherol isoform of vitamin E exerts more pro-inflammatory effects. In maternal-fetal environments, increased plasma α-tocopherol concentrations are associated with positive birth outcomes, while higher γ-tocopherol concentrations are linked with negative pregnancy outcomes. However, little is known about tocopherol concentrations in placental tissue and their role in modulating placental oxidative stress, a process that is implicated in many complications of pregnancy. The objectives of this research are to evaluate the concentrations of α- and γ-tocopherol in placental tissue and assess relationships with maternal and umbilical cord plasma concentrations. A total of 82 mother-infant dyads were enrolled at the time of delivery, and maternal and umbilical cord blood samples and placenta samples were collected. α- and γ-tocopherol concentrations in these samples were analyzed by high-performance liquid chromatography (HPLC). γ-tocopherol concentrations demonstrated significant, positive correlations among all sample types (p-values < 0.001). Placental tissue had a significantly lower ratio of α:γ-tocopherol concentrations when compared to maternal plasma and umbilical cord plasma (2.9 vs. 9.9 vs. 13.2, respectively; p < 0.001). Additional research should explore possible mechanisms for tocopherol storage and transfer in placental tissue and assess relationships between placental tocopherol concentrations and measures of maternal-fetal oxidative stress and clinical outcomes of pregnancy.

Plasma Retinol Concentrations and Dietary Intakes of Mother-Infant Sets in Singleton versus Twin Pregnancy

Vitamin A (retinol) is essential for normal fetal development, but the recommendation for maternal dietary intake (Retinol Activity Equivalent, RAE) does not differ for singleton vs. twin pregnancy, despite the limited evaluation of retinol status. Therefore, this study aimed to evaluate plasma retinol concentrations and deficiency status in mother-infant sets from singleton vs. twin pregnancies as well as maternal RAE intake. A total of 21 mother-infant sets were included (14 singleton, 7 twin). The HPLC and LC-MS/HS evaluated the plasma retinol concentration, and data were analyzed using the Mann-Whitney U test. Plasma retinol was significantly lower in twin vs. singleton pregnancies in both maternal (192.2 vs. 312.1 vs. mcg/L, p = 0.002) and umbilical cord (UC) samples (102.5 vs. 154.4 vs. mcg/L, p = 0.002). The prevalence of serum-defined vitamin A deficiency (VAD) <200.6 mcg/L was higher in twins vs. singletons for both maternal (57% vs. 7%, p = 0.031) and UC samples (100% vs. 0%, p < 0.001), despite a similar RAE intake (2178 vs. 1862 mcg/day, p = 0.603). Twin pregnancies demonstrated a higher likelihood of vitamin A deficiency in mothers, with an odds ratio of 17.3 (95% CI: 1.4 to 216.6). This study suggests twin pregnancy may be associated with VAD deficiency. Further research is needed to determine optimal maternal dietary recommendations during twin gestation.

Nutrition Support Practices for Infants Born <750 Grams or <25 Weeks Gestation: A Call for More Research

With advances in medical care and efforts to care for continually smaller and younger preterm infants, the gestational age of viability has decreased, including as young as 21 or 22 weeks of gestation [...].

Polyunsaturated Fatty Acids in Mother, Infant, and Placental Tissue, and Their Relationship With Pre-Pregnancy BMI

Objectives

Maternal obesity produces inflammation, which may result in adverse pregnancy outcomes such as preterm birth. Polyunsaturated fatty acids (PUFA), including omega-6 (n-6) and omega-3 (n-3) fatty acids, regulate inflammation and may mitigate the negative effects of inflammation. Previous studies report higher n-6 and lower n-3 PUFA concentration in early to mid-pregnancy for individuals with higher pre-pregnancy BMI (pBMI). However, the relationship between PUFA concentration at delivery and pBMI are not well understood. The purpose of this study is to determine the relationship between pBMI and maternal plasma, umbilical cord plasma, and placental PUFA concentrations, as well as PUFA intrauterine transfer percentage (IUTP).

Methods

Following IRB approval, maternal plasma, umbilical cord plasma, and placental samples were collected at delivery from 55 maternal-infant dyads. IUTPs for each PUFA (linoleic acid (LA), α-linolenic acid (ALA), arachidonic acid (AA), docosapentaenoic acid (DPA), docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA)) were calculated as [cord blood]/[maternal blood] × 100. Spearman's correlations assessed relationships between PUFA levels, PUFA IUTP, and pBMI. Linear regression models were adjusted for smoking status. A p-value < 0.05 was considered statistically significant.

Results

The mean pBMI for our cohort was 28.7 kg/m². Preceding pregnancy, 21% of mothers were normal or underweight, 36% overweight, and 43% obese. Maternal LA (R = −0.3, p = 0.03), maternal DHA (R = −0.27, p = 0.04), and placental EPA (R = −0.42, p = 0.02) were significantly correlated with maternal pBMI. After adjusting for smoking status, no correlations remained significant. PUFA cord levels and PUFA IUTP were not correlated to pBMI.

Conclusions

To our knowledge, this is the first study exploring relationships between pBMI and PUFA levels at delivery. Our findings contrast with previous research reporting correlations between PUFA levels and pBMI in early to mid-pregnancy. The effects of pBMI on PUFA status may be most prominent early in pregnancy. Future research should explore the relationship between pBMI and PUFA levels across all stages of pregnancy.

Funding Sources

UNMC Pediatrics Department; Child Health Research Institute.

Comparison of Vitamin E Isoforms Among Plasma, Breast Milk, and Dietary Intake Measure of Mother-Infant Dyads

Objectives

Vitamin E is a fat-soluble nutrient with four isoforms: α-, β-, δ-, and γ-tocopherol. These isoforms differentially modulate inflammation and are related to important perinatal outcomes such as preterm delivery and Apgar scores. Understanding the dietary consumption of these isoforms and their respective prevalence in biological samples is an important component to optimize nutritional recommendations. The purpose of this study is to compare tocopherol isoform proportions among maternal, cord, and neonatal plasma; maternal breast milk; and maternal dietary intake.

Methods

Samples of maternal breast milk and maternal, cord, and neonatal plasma were obtained within 1 month following delivery for maternal-infant dyads (N = 17) from the neonatal intensive care unit. Maternal dietary intake was assessed using the Harvard Willett Food Frequency Questionnaire. Relative proportions of α-, δ-, and γ-tocopherol in each sample type were measured and median tocopherol concentrations were compared using Kruskal-Wallis tests. A p-value < 0.05 was statistically significant.

Results

Total tocopherol concentrations were significantly different across sample groups (P < 0.001). Concentrations were highest in maternal serum, followed by neonatal serum, maternal breast milk, and umbilical cord serum. In all samples, α-tocopherol had the highest relative proportion, followed by γ- and δ-tocopherol, respectively. Compared to all biological samples, the dietary intake proportion of γ-tocopherol was significantly higher (P < 0.001), while the proportion of α-tocopherol was significantly lower (p = 0.04).

Conclusions

We observed significant differences in tocopherol concentrations across related biological samples, with maternal plasma containing the highest concentration and umbilical cord plasma the lowest. Mothers also consumed significantly higher percentages of γ-tocopherol than those found in both their plasma and breast milk. This suggests that proportions of individual tocopherol isoforms are influenced by factors other than dietary intake. Additional research should explore these associations in a larger cohort and analyze the effects of supplementation on tocopherol concentrations.

Funding Sources

UNMC Pediatrics Department; Child Health Research Institute.

Do Maternal Dietary Carotenoids Modify the Relationship Between Pre-Pregnancy BMI and Pregnancy Outcomes? Findings From An Exploratory Analysis

Objectives

Previous studies show that pre-pregnancy BMI (pBMI) is an independent determinant for pregnancy outcomes, but less is known about what mediates this relationship. Carotenoids are dietary antioxidants that may be able to attenuate inflammation and oxidative stress generated by maternal obesity. The objective of this study is to determine whether carotenoid levels have the potential to modify the relationship between pBMI pregnancy outcomes in a cohort of mothers who delivered at a Midwestern academic medical center.

Methods

Following IRB approval, maternal and cord blood samples were collected in mother-infant pairs. Serum nutrient levels were measured using High Performance Liquid Chromatography. Maternal serum carotenoids (including lutein + zeaxanthin, beta-cryptoxanthin, total lycopene, alpha-carotene, total beta-carotene, and retinol) and pBMI data were available for 229 mothers. BMIs recorded up to 10 weeks into pregnancy were considered pBMI. Logistic regression models assessed relationships between pBMI and binary pregnancy outcomes (caesarian section (CS), preeclampsia, and gestational diabetes). Initial models were adjusted for infant gestational age (GA). Subsequent models adjusted for levels of pro-vitamin A (retinol) and non-provitamin A (lutein + zeaxanthin) carotenoids. A p-value of < 0.05 was considered statistically significant.

Results

Preceding pregnancy, 1.3% (n = 3), 40.2% (n = 92), 27.5% (n = 63), and 31.0% (n = 71) of the mothers were underweight, normal weight, overweight, and obese, respectively. In the models adjusted for GA, pBMI was associated with higher risk of CS (odds ratio [OR] 1.06, p = 0.01), preeclampsia (OR 1.07, p < 0.001) and gestational diabetes (OR 1.10, p = 0.007). In two separate models, one adjusting for retinol levels and one for non-provitamin A carotenoid levels, associations with preeclampsia were no longer significant. Associations with CS and gestational diabetes remained significant after adjustment.

Conclusions

In this population, there was evidence of maternal carotenoid levels modifying the relationship between pBMI and preeclampsia. Future studies should further explore the ability of carotenoids to influence pregnancy outcomes.

Funding Sources

UNMC Pediatrics Department; Child Health Research Institute.

Assessing the Impact of Socioeconomic Status on Maternal and Cord Serum Omega-3 Polyunsaturated Fatty Acid Levels

Objectives

Omega-3 (n-3) polyunsaturated fatty acids (PUFAs) are essential in fetal growth and development and have been shown to modulate inflammatory processes throughout the lifespan. Previous studies have demonstrated that individuals with lower socioeconomic status (SES) may be at risk for low intake of n-3 PUFAs, however, no research has compared the concentrations of these nutrients present in maternal and cord serum between markers of SES. The purpose of this study is to assess the relationship between markers of SES and levels of n-3 PUFAs in maternal and cord serum in a group of patients delivering at a Midwest Academic Medical Center.

Methods

An IRB-approved study enrolled mother-infant pairs (n = 55) at the time of delivery for collection of maternal and cord serum samples. n-3 PUFA levels quantified included Eicosapentaenoic acid (EPA), Docosahexaenoic acid (DHA), and total n-3 PUFAs. Markers of SES include private vs public insurance, income ≤ 150% of the poverty line vs > 150%, and college degree earners vs no college degree. The Mann-Whitney U test was used to assess differences in n-3 PUFA levels between SES groups. A P < 0.05 was considered statistically significant.

Results

Median gestational age at delivery was 39.3 weeks. Significantly higher nutrient levels were present in college-educated mothers vs less than college-educated mothers in median maternal EPA (9.44 µg/mL vs 5.13 µg/mL, p = 0.010), cord EPA (1.88 µg/mL vs 1.40 µg/mL, p = 0.011), cord DHA (37.96 µg/mL vs 32.80 µg/mL, p = 0.014), and total cord n-3 PUFAs (44.23 µg/mL vs 39.34 µg/mL, p = 0.024). Median cord EPA levels were significantly higher in those with private insurance compared to public (1.79 µg/mL, 1.18 µg/mL, p = 0.022). Additionally, median cord EPA levels were significantly higher in those > 150% the poverty line (1.79 µg/mL, 1.10 µg/mL, p = 0.030).

Conclusions

Our findings suggest that individuals with lower SES may be at risk for lower serum levels of n-3 PUFAs in pregnancy, which could increase their susceptibility to adverse birth and pregnancy outcomes. Future studies should focus on replicating these results in a larger, more heterogeneous sample and should consider analyzing additional markers of SES.

Funding Sources

UNMC Pediatrics Department; Child Health Research Institute.

Omega-6 and Omega-3 Fatty Acid-Derived Oxylipins from the Lipoxygenase Pathway in Maternal and Umbilical Cord Plasma at Delivery and Their Relationship with Infant Growth

Omega-3 and omega-6 fatty acids are important for neonatal development and health. One mechanism by which omega-3 and omega-6 fatty acids exert their effects is through their metabolism into oxylipins and specialized pro-resolving mediators. However, the influence of oxylipins on fetal growth is not well understood. Therefore, the objective of this study was to identify oxylipins present in maternal and umbilical cord plasma and investigate their relationship with infant growth. Liquid chromatography-tandem mass spectrometry was used to quantify oxylipin levels in plasma collected at the time of delivery. Spearman's correlations highlighted significant correlations between metabolite levels and infant growth. They were then adjusted for maternal obesity (normal body mass index (BMI: ≤30 kg/m²) vs. obese BMI (>30 kg/m²) and smoking status (never vs. current/former smoker) using linear regression modeling. A p-value < 0.05 was considered statistically significant. Our study demonstrated a diverse panel of oxylipins from the lipoxygenase pathway present at the time of delivery. In addition, both omega-3 and omega-6 oxylipins demonstrated potential influences on the birth length and weight percentiles. The oxylipins present during pregnancy may influence fetal growth and development, suggesting potential metabolites to be used as biomarkers for infant outcomes.

QuPath Digital Immunohistochemical Analysis of Placental Tissue

Background:

QuPath is an open-source digital image analyzer notable for its user-friendly design, cross-platform compatibility, and customizable functionality. Since it was first released in 2016, at least 624 publications have reported its use, and it has been applied in a wide spectrum of settings. However, there are currently limited reports of its use in placental tissue. Here, we present the use of QuPath to quantify staining of G-protein coupled receptor 18 (GPR18), the receptor for the pro-resolving lipid mediator Resolvin D2, in placental tissue.

Methods:

Whole slide images of vascular smooth muscle (VSM) and extravillous trophoblast (EVT) cells stained for GPR18 were annotated for areas of interest. Visual scoring was performed on these images by trained and in-training pathologists, while QuPath scoring was performed with the methodology described herein.

Results:

Bland–Altman analyses showed that, for the VSM category, the two methods were comparable across all staining levels. For EVT cells, the high-intensity staining level was comparable across methods, but the medium and low staining levels were not comparable.

Conclusions:

Digital image analysis programs offer great potential to revolutionize pathology practice and research by increasing accuracy and decreasing the time and cost of analysis. Careful study is needed to optimize this methodology further.

Plasma Concentrations and Maternal-Umbilical Cord Plasma Ratios of the Six Most Prevalent Carotenoids across Five Groups of Birth Gestational Age

Carotenoids are antioxidant nutrients with the potential to provide protection against oxidative stress. Plasma carotenoid concentrations are lower in newborn infants compared to their mothers; however, limited information is available regarding how concentrations differ by gestational age. The objective of this research is to assess maternal and umbilical cord plasma carotenoid concentrations and maternal-umbilical cord plasma ratios across five groups of birth gestational age. Mother-infant dyads were enrolled at delivery for collection of maternal and umbilical cord blood. Plasma carotenoids were analyzed by HPLC and LC-MS/MS. Birth gestational age was categorized into five groups, and the Kruskal–Wallis test compared carotenoid concentrations and maternal-umbilical cord plasma ratios between these groups. A p-value of < 0.05 was considered statistically significant. 370 mother-infant dyads were included, with most infants delivered at early term (20.3%) or term (64.6%). Though maternal plasma concentrations increased with birth gestational age, we observed less variability in umbilical cord plasma concentrations, thus the maternal-umbilical cord plasma ratio also increased with birth CGA groups for lutein + zeaxanthin (p = 0.008), β-cryptoxanthin (p = 0.027), α-carotene (p = 0.030); β-carotene approached significance (p = 0.056). Additional research is needed to determine if carotenoid concentrations were physiologic to varying gestational ages or if they were impacted by factors associated with preterm birth.

Early Enteral Feeding in Preterm Infants: A Narrative Review of the Nutritional, Metabolic, and Developmental Benefits

Enteral feeding is the preferred method of nutrient provision for preterm infants. Though parenteral nutrition remains an alternative to provide critical nutrition after preterm delivery, the literature suggests that enteral feeding still confers significant nutritional and non-nutritional benefits. Therefore, the purpose of this narrative review is to summarize health and clinical benefits of early enteral feeding within the first month of life in preterm infants. Likewise, this review also proposes methods to improve enteral delivery in clinical care, including a proposal for decision-making of initiation and advancement of enteral feeding. An extensive literature review assessed enteral studies in preterm infants with subsequent outcomes. The findings support the early initiation and advancement of enteral feeding impact preterm infant health by enhancing micronutrient delivery, promoting intestinal development and maturation, stimulating microbiome development, reducing inflammation, and enhancing brain growth and neurodevelopment. Clinicians must consider these short- and long-term implications when caring for preterm infants.

Growth and Malnutrition Assessment of Neonates Admitted to a Government Hospital in Nakuru, Kenya

Background and Aims: Inadequate nutrient provision causes neonatal growth failure and malnutrition. Therefore, this study aimed to 1) quantify infant growth velocity from birth to hospital discharge, 2) determine the incidence of neonatal malnutrition at the time of discharge from a government hospital newborn unit in Nakuru, Kenya. Methods: After ethical approval, data was collected for infants (n=104) hospitalized >14 days (June 2016 - December 2018) including: birth gestational age (GA), birth and discharge weight (grams, g) with z-scores (2013 Fenton Preterm or 2006 World Health Organization 0-2 Year growth chart), hospital length of stay (LOS) days. Growth during hospitalization was calculated in g/day [(discharge weight – birth weight)/LOS] and g/kilogram(kg)/day [1000xln(birth weight/discharge weight)/LOS). Malnutrition was diagnosed by birth to discharge weight z-score change (decline): mild = 0.8-1.2 standard deviations (SD), moderate = >1.2-2.0 SD, severe = >2.0 SD. P-value <0.05 was significant. Results: 94/104 (90.4%) infants were preterm with median birth GA 32 weeks, weight 1500 g (z-score -0.33), LOS 21 days and discharge weight 1735 g (z-score -1.95). Median weight gain was 8.2 g/day or 5.2 g/kg/day with weight z-score change -1.34 SD. Linear regression predicted each hospital day decreased z-score by -0.031 (p<0.001). At discharge, 81.7% of infants met malnutrition criteria—27.1% mild, 49.4% moderate, 23.5% severe. Conclusions: Infants with LOS >14 days in a government hospital newborn unit in Nakuru, Kenya, experience growth rates below recommended velocities by the World Health Organization (23-34 grams/day from 0-4 months). Nutrition intervention is necessary to support appropriate growth.

Intrauterine Transfer of Polyunsaturated Fatty Acids in Mother-Infant Dyads as Analyzed at Time of Delivery

Polyunsaturated fatty acids (PUFAs) are essential for fetal development, and intrauterine transfer is the only supply of PUFAs to the fetus. The prevailing theory of gestational nutrient transfer is that certain nutrients (including PUFAs) may have prioritized transport across the placenta. Numerous studies have identified correlations between maternal and infant fatty acid concentrations; however, little is known about what role maternal PUFA status may play in differential intrauterine nutrient transfer. Twenty mother–infant dyads were enrolled at delivery for collection of maternal and umbilical cord blood, and placental tissue samples. Plasma concentrations of PUFAs were assessed using gas chromatography (GC-FID). Intrauterine transfer percentages for each fatty acid were calculated as follows: ((cord blood fatty acid level/maternal blood fatty acid level) × 100). Kruskal–Wallis tests were used to compare transfer percentages between maternal fatty acid tertile groups. A p-value < 0.05 was considered significant. There were statistically significant differences in intrauterine transfer percentages of arachidonic acid (AA) (64% vs. 65% vs. 45%, p = 0.02), eicosapentaenoic acid (EPA) (41% vs. 19% vs. 17%, p = 0.03), and total fatty acids (TFA) (27% vs. 26% vs. 20%, p = 0.05) between maternal plasma fatty acid tertiles. Intrauterine transfer percentages of AA, EPA, and TFA were highest in the lowest tertile of respective maternal fatty acid concentration. These findings may indicate that fatty acid transfer to the fetus is prioritized during gestation even during periods of maternal nutritional inadequacy.

Effect of Maternal Retinol Status at Time of Term Delivery on Retinol Placental Concentration, Intrauterine Transfer Rate, and Newborn Retinol Status

Retinol (vitamin A) is essential, so the objective of this Institutional Review Board approved study is to evaluate retinol placental concentration, intrauterine transfer, and neonatal status at time of term delivery between cases of maternal retinol adequacy, insufficiency, and deficiency in a United States population. Birth information and biological samples were collected for mother–infant dyads (n = 260). Maternal and umbilical cord blood retinol concentrations (n = 260) were analyzed by HPLC and categorized: deficient (≤0.7 umol/L), insufficient (>0.7–1.05 umol/L), adequate (>1.05 umol/L). Intrauterine transfer rate was calculated: (umbilical cord blood retinol concentration/maternal retinol concentration) × 100. Non-parametric statistics used include Spearman’s correlations, Mann–Whitney U, and Kruskal–Wallis tests. p-values <0.05 were statistically significant. Only 51.2% of mothers were retinol adequate, with 38.4% insufficient, 10.4% deficient. Only 1.5% of infants were retinol adequate. Placental concentrations (n = 73) differed between adequate vs. deficient mothers (median 0.13 vs. 0.10 μg/g; p = 0.003). Umbilical cord blood concentrations were similar between deficient, insufficient, and adequate mothers (0.61 vs. 0.55 vs. 0.57 μmol/L; p = 0.35). Intrauterine transfer increased with maternal deficiency (103.4%) and insufficiency (61.2%) compared to adequacy (43.1%), p < 0.0001. Results indicate that intrauterine transfer rate is augmented in cases of maternal retinol inadequacy, leading to similar concentrations in umbilical cord blood at term delivery.

Associations Between Maternal Tocopherol Levels and Pregnancy-Induced Blood Pressure Changes

Objectives

Vitamin E plays different roles in health based on its three isoforms: alpha (α)-tocopherol is anti-inflammatory, gamma (γ)-tocopherol is pro-inflammatory, delta (δ)-tocopherol remains unknown. As inflammation may promote hypertension, the objective of this study is to examine relationships between maternal serum tocopherol levels at time of delivery and pregnancy-related blood pressure (BP) changes. Hypothesis is that increased level of α-tocopherol has favorable effects and γ-tocopherol has adverse effects on maternal BP.

Methods

An IRB-approved cross-sectional study enrolled mother-infant dyads (n = 342) at time of delivery (Omaha, NE, USA) for collection of electronic health data and maternal blood. High-performance liquid chromatography analyzed serum tocopherol levels. Maternal BP values were collected from 1st and 3rd trimester clinic/hospital visits with changes calculated in systolic BP and mean arterial pressure (MAP = diastolic BP + 1/3(systolic BP – diastolic BP). Mothers were classified as hypertensive if: systolic BP ≥140, diastolic BP ≥ 90, or diagnosis of preeclampsia. Two-sample t-test and Pearson correlation coefficients compared relationships between serum tocopherol levels and BP data. P-value &lt; 0.05 was significant.

Results

Mean maternal age was 28.5 years, majority (61.4%) Caucasian, 10.4% (n = 29) with hypertension. Mean serum levels: α-tocopherol 15,229 + 5849 mcg/L, γ-tocopherol 1642 + 868 mcg/L, δ-tocopherol 226 + 164 mcg/L, with α: γ ratio 11.5 + 8.7. Mean serum α-tocopherol level was higher in normotensive vs. hypertensive mothers (15,751 vs. 13,819 mcg/L; P = 0.06). Ratio of α: γ demonstrated an inverse correlation with change in maternal systolic BP (r = −0.128; P = 0.03). No other relationships were significant.

Conclusions

Increasing maternal α-tocopherol and α: γ ratio has favorable association with maintaining normal BP during pregnancy. More research is needed to specifically identify serum thresholds and tocopherol isoform ratios for favorably reducing risk of pregnancy-related hypertension.

Funding Sources

Department of Pediatrics and the Child Health Research Institute at the University of Nebraska Medical Center and Children's Hospital & Medical Center (Omaha, NE).

Fat-soluble nutrients and Omega-3 fatty acids as modifiable factors influencing preterm birth risk

Preterm birth is a leading cause of child morbidity and mortality, so strategies to reduce early birth must remain a priority. One key approach to enhancing birth outcomes is improving maternal dietary intake. Therefore, the purpose of this review is to discuss mechanisms on perinatal status of fat-soluble nutrients (carotenoids, retinol, tocopherols) and omega-3 fatty acids and how they impact risk for preterm birth. Literature review demonstrates that maternal dietary intake and biological (blood and placental tissue) levels of fat-soluble nutrients during pregnancy may provide antioxidative, anti-inflammatory, and immunomodulatory health benefits. Omega-3 fatty acids also promote increased production of specialized pro-resolving mediators, subsequently mediating inflammation resolution. Combined effects of these nutrients support appropriate placental organogenesis and function. Consequently, fat-soluble nutrients and omega-3 fatty acids serve as strong influencers for preterm birth risk. As dietary intake remains a modifiable factor, future intervention would benefit from a focus on optimizing perinatal status of these specific nutrients.

Quantification of Lutein + Zeaxanthin Presence in Human Placenta and Correlations with Blood Levels and Maternal Dietary Intake

Lutein + zeaxanthin (L + Z) are carotenoids recognized in eye health, but less is known about their status during pregnancy. While quantified in maternal and umbilical cord blood, they have never been analyzed in placenta. The purpose of this study is to quantify combined L + Z concentrations in human placenta and correlate with levels in maternal dietary intake, maternal serum, and umbilical cord blood. The proportions of combined L + Z were compared within diet, placenta, maternal serum, and umbilical cord blood among additional carotenoids (lycopene, β-cryptoxanthin, α-carotene, and β-carotene). This Institutional Review Boardapproved cross-sectional study enrolled 82 mother-infant pairs. Placenta, maternal serum, and umbilical cord blood samples were analyzed for carotenoids concentrations. Mothers completed a food frequency questionnaire and demographic/birth outcome data were collected. L + Z were present in placenta, median 0.105 micrograms/gram (mcg/g) and were significantly correlated with maternal serum (r = 0.57; p < 0.001), umbilical cord blood levels (r = 0.49; p = 0.001), but not dietary intake (p = 0.110). L + Z were the most prevalent in placenta (49.1%) umbilical cord blood (37.0%), but not maternal serum (18.6%) or dietary intake (19.4%). Rate of transfer was 16.0%, the highest of all carotenoids. Conclusively, L + Z were identified as the two most prevalent in placenta. Results highlight unique roles L + Z may play during pregnancy.

Immunohistochemical characteristics of porcine intrahepatic nerves under physiological conditions and after bisphenol A administration

BACKGROUND

The neurochemistry of hepatic nerve fibres was investigated in large animal models after dietary exposure to the endocrine disrupting compound known as bisphenol A (BPA).

MATERIALS AND METHODS

Antibodies against neuronal peptides were used to study changes in hepatic nerve fibres after exposure to BPA at varying concentrations using standard immunofluorescence techniques. The neuropeptides investigated were substance P (SP), galanin (GAL), pituitary adenylate cyclase activating polypeptide (PACAP), calcitonin gene regulated peptide (CGRP) and cocaine and amphetamine regulated transcript (CART). Immunoreactive nerve fibres were counted in multiple sections of the liver and among multiple animals at varying exposure levels. The data was pooled and presented as mean ± standard error of the mean.

RESULTS

It was found that all of the nerve fibres investigated showed upregulation of these neural markers after BPA exposure, even at exposure levels currently considered to be safe. These results show very dramatic increases in nerve fibres containing the above-mentioned neuropeptides and the altered neurochemical levels may be causing a range of pathophysiological states if the trend of over-expression is extrapolated to developing humans.

CONCLUSIONS

This may have serious implications for children and young adults who are exposed to this very common plastic polymer, if the same trends are occurring in humans.

Randomized trial of two doses of vitamin D3 in preterm infants <32 weeks: Dose impact on achieving desired serum 25(OH)D3 in a NICU population

BACKGROUND

Recommendations for vitamin D supplementation for preterm infants span a wide range of doses. Response to vitamin D supplementation and impact on outcomes in preterm infants is not well understood.

OBJECTIVE

Evaluate serum 25(OH)D3 concentration changes after 4 weeks in response to two different doses of vitamin D3 supplementation in a population of premature infants and quantify the impact on NICU outcomes.

DESIGN

32 infants born at 24-32 weeks gestation were prospectively randomized to receive 400 or 800 IU/day vitamin D3 supplementation. Serum 25(OH)D3 levels were measured every 4 weeks. The Wilcoxon signed rank test was used to compare serum levels of 25(OH)D3 at 4 weeks and each subsequent time point. A p-value of <0.05 was considered statistically significant.

RESULTS

Serum 25(OH)D3 levels at birth were 41.9 and 42.9 nmol/l for infants in the 400 IU group and 800 IU group, respectively (p = 0.86). Cord 25(OH)D3 concentrations significantly correlated with gestational age (r = 0.40, p = 0.04). After 4 weeks of D3 supplementation, median 25(OH)D3 levels increased in both groups (84.6vs. 105.3 nmol/l for 400 vs. 800 IU/day respectively, with significantly more improvement in the higher dose (p = 0.048). Infants in the 400 IU group were significantly more likely to have dual energy x-ray absorptiometry (DEXA) bone density measurements <10 percentile (56% vs 16%, p = 0.04).

CONCLUSIONS

Improvement in 25(OH)D3 levels at 4 weeks, bone density, and trends towards improvement in linear growth support consideration of a daily dose of 800 IU of vitamin D for infants <32 weeks cared for in the NICU.

Comparison of a Powdered, Acidified Liquid, and Non-Acidified Liquid Human Milk Fortifier on Clinical Outcomes in Premature Infants

We previously compared infant outcomes between a powdered human milk fortifier (P-HMF) vs. acidified liquid HMF (AL-HMF). A non-acidified liquid HMF (NAL-HMF) is now commercially available. The purpose of this study is to compare growth and outcomes of premature infants receiving P-HMF, AL-HMF or NAL-HMF. An Institutional Review Board (IRB) approved retrospective chart review compared infant outcomes (born < 2000 g) who received one of three HMF. Growth, enteral nutrition, laboratory and demographic data were compared. 120 infants were included (P-HMF = 46, AL-HMF = 23, NAL-HMF = 51). AL-HMF infants grew slower in g/day (median 23.66 vs. P-HMF 31.27, NAL-HMF 31.74 (p < 0.05)) and in g/kg/day, median 10.59 vs. 15.37, 14.03 (p < 0.0001). AL-HMF vs. NAL-HMF infants were smaller at 36 weeks gestational age (median 2046 vs. 2404 g, p < 0.05). However AL-HMF infants received more daily calories (p = 0.21) and protein (p < 0.0001), mean 129 cal/kg, 4.2 g protein/kg vs. P-HMF 117 cal/kg, 3.7 g protein/kg , NAL-HMF 120 cal/kg, 4.0 g protein/kg. AL-HMF infants exhibited lower carbon dioxide levels after day of life 14 and 30 (p < 0.0001, p = 0.0038). Three AL-HMF infants (13%) developed necrotizing enterocolitis (NEC) vs. no infants in the remaining groups (p = 0.0056). A NAL-HMF is the most optimal choice for premature human milk-fed infants in a high acuity neonatal intensive care unit (NICU).

Overview of the role of vitamins and minerals on the kynurenine pathway in health and disease

The kynurenine pathway (KP) of L-tryptophan metabolism produces several neuroactive metabolites with an amino acid structure. These metabolites may play an important role in the pathophysiology of irritable bowel syndrome, Alzheimer's disease, Parkinson's disease, Huntington's disease, schizophrenia, AIDS-dementia complex, depression, epilepsy and the aging process. Modulation of the KP through inhibition or stimulation of enzyme synthesis and activity can be an alternative approach to traditional therapy. Furthermore, it may be responsible for the altered functioning of the enteric nervous system and the central nervous system. There is evidence that the KP is sensitive to changes in the concentration of many vitamins and minerals that play a crucial role as coenzymes and cofactors in the de novo synthesis of nicotinamide adenine dinucleotide coenzyme. A reduction in the availability of the active form of vitamin B6 (pyridoxal 5'-phosphate, PLP) is known to affect tryptophan hydroxylase, kynurenine aminotransferase and kynureninase (KYNU). Vitamin B2 deficiencies result in a reduction in the activity of the flavin adenine dinucleotide dependent enzyme, kynurenine 3-monooxygenase. Minerals are also responsible for the proper functioning of enzymes engaged in L-tryptophan metabolism. Mn(2+), Zn(2+), Co(2+) and Cu(2+) influence KYNU activity, and Mg(2+) regulates quinolinate phosphoribosyl transferase. Fe(2+) is responsible for the proper functioning of both indoleamine 2,3-dioxygenase and 3-hydroxy-anthranilic acid dioxygenase. Changes in the concentration of KP metabolites and in enzymatic activity have been found in many pathological states. Therefore, it is justifiable to regulate the concentration of certain kynurenines or enzymes in the KP which may provide a potential therapeutic target for the treatment of various health impairments. This review demonstrates the role of vitamin and mineral activity on the KP, which may have an effect on the proper functioning of the human organism. Surplus administration of vitamins did not elicit any beneficial effects on L-tryptophan metabolism. Whether a mineral surplus influences L-tryptophan metabolism is still not established. It seems that cofactor deficiencies influence the KP far more than surpluses.

Response of vitamin D binding protein and free vitamin D concentrations to vitamin D supplementation in hospitalized premature infants

OBJECTIVE

The objective of this study was to evaluate the relationship between 25(OH)D, Vitamin D Binding Protein (DBP), and free vitamin D in premature infants.

METHODS

Thirty-two infants <32 weeks' gestation were randomized to two different levels of vitamin D3 supplementation (400 vs. 800 IU/day). 25(OH)D levels were measured by LC-MS/MS; DBP was measured by validated ELISA. Free vitamin D was calculated using molar ratios of 25(OH)D and DBP. The Wilcoxon signed rank test was used to compare DBP, free D and 25(OH)D levels; Spearman's correlation coefficients were used to assess correlations.

RESULTS

The mean gestational age at birth was 30.5 weeks; mean birth weight was 1405 g. Mean 25(OH)D levels at birth were 17.3 ng/mL; DBP levels were 297 mg/L, and estimated free vitamin D levels were 18.9. There was a statistically significant change in 25(OH)D levels after 8 weeks (24.6 vs. 39.1 ng/mL in the 400 vs. 800 group, respectively, p=0.02). DBP levels from birth to 8 weeks showed a statistically significant decrease (267 vs. 208, p=0.04). Estimated free 25(OH)D concentrations increased over the study period, from 18.9 at birth to 64.7 at 8 weeks of age (p=0.0001). Free vitamin D levels at birth were associated with global DEXA bone mineral content at discharge from the NICU (r=0.58, p=0.05).

CONCLUSION

Supplementation with vitamin D3 increased the free portion of the vitamin D metabolite, providing increased bioavailable substrate. Improved free vitamin D levels may improve measurable outcomes such as bone mineral content and deserve further evaluation.

Comparison of the effect of two human milk fortifiers on clinical outcomes in premature infants

The use of human milk fortifiers (HMF) helps to meet the high nutritional requirements of the human milk-fed premature infant. Previously available powdered products have not met the protein requirements of the preterm infant population and many neonatologists add powder protein modulars to help meet protein needs. The use of powdered products is discouraged in neonatal intensive care units (NICU) due to concern for invasive infection. The use of a commercially available acidified liquid product with higher protein content was implemented to address these two concerns. During the course of this implementation, poor growth and clinically significant acidosis of infants on Acidified Liquid HMF (ALHMF) was observed. The purpose of this study was to quantify those observations by comparing infant outcomes between groups receiving the ALHMF vs. infants receiving powdered HMF (PHMF). A retrospective chart review compared outcomes of human milk-fed premature infants<2000 g receiving the ALHMF (n=23) and the PHMF (n=46). Infant growth, enteral feeding tolerance and provision, and incidence of necrotizing enterocolitis (NEC), metabolic acidosis, and diaper dermatitis were compared between the two groups. No infants were excluded from this study based on acuity. Use of ALHMF resulted in a higher incidence of metabolic acidosis (p=0.002). Growth while on HMF as measured in both g/kg/day (10.59 vs. 15.37, p<0.0001) and in g/day (23.66 vs. 31.27, p=0.0001) was slower in the ALHMF group, on increased mean cal/kg/day (128.7 vs. 117.3, p=0.13) with nearly twice as many infants on the ALHMF requiring increased fortification of enteral feedings beyond 24 cal/ounce to promote adequate growth (48% vs. 26%, p=0.10). Although we were not powered to study NEC as a primary outcome, NEC was significantly increased in the ALHMF group. (13% vs. 0%, p=0.03). Use of a LHMF in an unrestricted NICU population resulted in an increase in clinical complications within a high-acuity NICU, including metabolic acidosis and poor growth. Although further research is needed to assess outcomes among infants with a variety of clinical acuities, gestational ages, and weights to confirm these findings, based on this experience, caution is urged to avoid potential risks.

Parenteral nutrition additive shortages: the short-term, long-term and potential epigenetic implications in premature and hospitalized infants

Nutrition support practitioners are currently dealing with shortages of parenteral nutrition micronutrients, including multivitamins (MVI), selenium and zinc. A recent survey from the American Society of Enteral and Parenteral Nutrition (ASPEN) indicates that this shortage is having a profound effect on clinical practice. A majority of respondents reported taking some aggressive measures to ration existing supplies. Most premature infants and many infants with congenital anomalies are dependent on parenteral nutrition for the first weeks of life to meet nutritional needs. Because of fragile health and poor reserves, they are uniquely susceptible to this problem. It should be understood that shortages and rationing have been associated with adverse outcomes, such as lactic acidosis and Wernicke encephalopathy from thiamine deficiency or pulmonary and skeletal development concerns related to inadequate stores of Vitamin A and D. In this review, we will discuss the current parenteral shortages and the possible impact on a population of very low birth weight infants. This review will also present a case study of a neonate who was impacted by these current shortages.

NCD activation of tubulin polymerization

Tubulin dimer (tT) was purified from turkey erythrocytes. The motor domain of Drosophila non-claret disjunctional protein, NCD(335-700), was expressed in E. coli and purified. At 37 degrees C in the presence of GTP, the rate of polymerization of tT to microtubule (tMt) is accelerated over threefold by the presence of NCD(335-700). At 10 degrees C, the rate of tT polymerization is increased from zero, within experimental error, in the absence of NCD(335-700) to rates near those observed at 37 degrees C when NCD(335-700) is present. The NCD(335-700) concentration dependence of the rate indicated the reactive species was NCD(335-700)(n).tT, with n approximately 2. At 10 degrees C in the absence of GTP, polymerization does not occur, but tT activates NCD(335-700) MgATPase activity 10-fold. For the same conditions, using mians-NCD(335-700), which is modified with 2-(4'-maleimidylanilino) naphthalene-6-sulfonic acid, the apparent K(D) for binding to tT is 2.3 x 10(-5) M in the presence of MgADP. Replacing ADP with AMPPNP or ATP has a negligible effect on K(D). Mians-NCD(335-700) binding to tMt is 10-fold stronger than to tT. The above data indicate NCD(335-700) binds at a functional site on tT. The stoichiometry is consistent with the formation of NCD(335-700)(2).tT which in vitro accelerates self-assembly initiation and/or polymerization by binding a second tT in a position favorable for tubulin-tubulin interaction. The data suggest that in vivo functional NCD binding to microtubule involves one motor domain binding to alpha- and beta-subunits at the interface of two different tubulin dimers in a protofilament.

The 0.78 A structure of a serine protease: Bacillus lentus subtilisin

Ultrahigh-resolution X-ray diffraction data from cryo-cooled, B. lentus subtilisin crystals has been collected to a resolution of 0.78 A. The refined model coordinates have a rms deviation of 0.22 A relative to the same structure determined at room temperature and 2.0 A resolution. Several regions of main-chain and side-chain disorder have been identified for 21 out of 269 residues in one polypeptide chain. Hydrogen atoms appear as significant peaks in the Fo - Fc difference electron density map, and carbon, nitrogen, and oxygen atoms can be differentiated. The estimated standard deviation (ESD) for all main-chain non-hydrogen bond lengths is 0.009 A and 0.5 degrees for bond angles based on an unrestrained full-matrix least-squares refinement. Hydrogen bonds are resolved in the serine protease catalytic triad (Ser-His-Asp). Electron density is observed for an unusual, short hydrogen bond between aspartic acid and histidine in the catalytic triad. The hydrogen atom, identified by NMR in numerous serine proteases, appears to be shared by the heteroatoms in the bond. This represents the first reported correlation between detailed chemical features identified by NMR and those in a cryo-cooled crystallographic structure determination at ultrahigh resolution. The short hydrogen bond, designated "catalytic hydrogen bond", occurs as part of an elaborate hydrogen bond network, involving Asp of the catalytic triad. While unusual, these features appear to have conserved analogues in other serine protease families although specific details differ from family to family.