Fetal Concentrations Research Articles

Transplacental Transfer of Oxytocin and Its Impact on Neonatal Cord Blood and In Vitro Retinal Cell Activity.

The development of fetal organs can be impacted by systemic changes in maternal circulation, with the placenta playing a pivotal role in maintaining pregnancy homeostasis and nutrient exchange. In clinical obstetrics, oxytocin (OXT) is commonly used to induce labor. To explore the potential role of OXT in the placental homeostasis of OXT, we compared OXT levels in neonatal cord blood among neonates (23-42 weeks gestation) whose mothers either received prenatal OXT or experienced spontaneous labor. Our previous research revealed that the oxytocin receptor (OXTR), essential in forming the blood-retina barrier, is expressed in the retinal pigment epithelium (RPE). We hypothesized that perinatal OXT administration might influence the development of the neural retina and its vasculature, offering therapeutic potential for retinal diseases such as retinopathy of prematurity (ROP). Plasma OXT levels were measured using a commercial OXT ELISA kit. Human fetal RPE (hfRPE) cells treated with OXT (10 µM) were assessed for gene expression via RNA sequencing, revealing 14 downregulated and 32 upregulated genes. To validate these differentially expressed genes (DEGs), hfRPE cells were exposed to OXT (0.01, 0.1, 1, or 10 µM) for 12 h, followed by RNA analysis via real-time PCR. Functional, enrichment, and network analyses (Gene Ontology term, FunRich, Cytoscape) were performed to predict the affected pathways. This translational study suggests that OXT likely crosses the placenta, altering fetal OXT concentrations. RNA sequencing identified 46 DEGs involved in vital metabolic and signaling pathways and critical cellular components. Our results indicate that the perinatal administration of OXT may affect neural retina and retinal vessel development, making OXT a potential therapeutic option for developmental eye diseases, including ROP.

Chronic late gestation fetal hyperglucagonaemia results in lower insulin secretion, pancreatic mass, islet area and beta- and α-cell proliferation.

Fetal glucagon concentrations are elevated in the presence of a compromised intrauterine environment, as in cases of placental insufficiency and perinatal acidaemia. Our objective was to investigate the impact of late gestation fetal hyperglucagonaemia on in vivo insulin secretion and pancreatic islet structure. Chronically catheterized late gestation fetal sheep received an intravenous infusion of glucagon at low (5ng/kg/min; GCG-5) or high (50ng/kg/min; GCG-50) concentrations or a vehicle control (CON) for 8-10days.Glucose-stimulated fetal insulin secretion (GSIS) was measured following 3h (acute response) and 8-10days (chronic response) of experimental infusions. Insulin, glucose and amino acid concentrations were measured longitudinally. The pancreas was collected at the study end for histology and gene expression analysis. Acute exposure (3h) to GCG-50 induced a 3-fold increase in basal insulin concentrations with greater GSIS. Meanwhile, chronic exposure to both GCG-5 and GCG-50 decreased basal insulin concentrations 2-fold by day 8-10. Chronic GCG-50 also blunted GSIS at the study end. Fetal amino acid concentrations were decreased within 24h of GCG-5 and GCG-50, while there were no differences in fetal glucose. Histologically, GCG-5 and GCG-50 had lower β- and α-cell proliferation, as well as lower α-cell mass and pancreas weight, while GCG-50 had lower islet area. This study demonstrates that chronic glucagon elevation in late gestation fetuses impairs β-cell proliferation and insulin secretion, which has the potential to contribute to later-life diabetes risk. We speculate that the action of glucagon in lower circulating fetal amino acid concentrations may have a suppressive effect on insulin secretion. KEY POINTS: We have previously demonstrated in a chronically catheterized fetal sheep model that experimentally elevated glucagon in the fetus impairs placental function, reduces fetal protein accretion and lowers fetal weight. In the present study, we further characterized the effects of elevated fetal glucagon on fetal physiology with a focus on pancreatic development and β-cell function. We show that experimentally elevated fetal glucagon results in lower β- and α-cell proliferation, as well as decreased insulin secretion after 8-10days of glucagon infusion. These results have important implications for β-cell reserve and later-life predisposition to diabetes.

The Interplay of Persistent Organic Pollutants and Mediterranean Diet in Association With the Risk of Gestational Diabetes Mellitus.

Certain foods characterizing the alternate Mediterranean diet (aMED) are high in persistent organic pollutants (POPs), which are related to greater gestational diabetes mellitus (GDM) risk. We examined the associations of combined aMED and POP exposure with GDM. aMED score of 1,572 pregnant women was derived from food frequency questionnaires at early pregnancy within the U.S. Fetal Growth Study and plasma concentrations of 76 POPs, including organochlorine pesticides, polybrominated diphenyl ethers, polychlorinated biphenyls (PCBs), and per- and polyfluoroalkyl substances, were measured. Associations of combined aMED score and exposure to POPs with GDM risk were examined by multivariable logistic regression models. In 61 of 1,572 (3.88%) women with GDM, 25 of 53 included POPs had a detection rate >50%. Higher POP levels appeared to diminish potential beneficial associations of aMED score with GDM risk, with the lowest GDM risk observed among women with both high aMED score and low POP concentrations. Specifically, adjusted log-odds ratios of GDM risk comparing women with low PCB and high aMED score with those with low aMED score and high PCB concentrations was -0.74 (95% CI -1.41, -0.07). Inverse associations were also observed among women with low aMED score and high TransNo_chlor, PCB182_187, PCB196_203, PCB199, and PCB206. These associations were more pronounced among women with overweight or obesity. Pregnant women who consumed a healthy Mediterranean diet but had a low exposure to POP concentrations had the lowest GDM risk. Future endeavors to promote a healthy diet to prevent GDM may consider concurrent POP exposure.

Establishment a cell line of splenic fibroblasts from golden pompano and its application in heavy metal toxicology and pathogen infection

A cell line derived from golden pompano Trachinotus ovatus splenic fibroblasts (TOSF) was established, its application in toxicology and virus susceptibility was demonstrated in this study. The TOSF cells grew fastest with the L-15 medium containing 10% fetal bovine serum concentration at 28 °C. The chromosomal number of normal TOSF cells was 2N = 48. TOSF cells showed high sensitivity to grouper iridovirus (SGIV) and nervous necrosis virus (NNV). Cadmium and copper had toxic effects on TOSF cells, which could cause an oxidative stress response in TOSF cells and activate the antioxidant system to regulate the reactive oxygen species (ROS), malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), and glutathione reductase (GSH) level in the cells. Cadmium and copper had an impact on the replication of SGIV and NNV in the TOSF cells, and copper could limit the proliferation of Aeromonas hydrophila in TOSF cells. Generally, the TOSF cell line can apply for heavy metal toxicity mechanisms study and environment monitoring, as well as the pathogen infection mechanism research.

Long-chain perfluoroalkylether carboxylic acids PFO5DoA and PFO4DA alter glucose, bile acid, and thyroid hormone homeostasis in fetal rats from 5-day maternal oral exposure

Chemical monitoring studies in North Carolina, USA and Shandong, China have reported detections of perfluoroalkylether carboxylic acids of increasing chain length with ether bonds between each fluorinated carbon. Despite detection there is limited hazard data available to inform risk assessment. Here, we exposed pregnant Sprague-Dawley rats to two of these compounds, perfluoro-3,5,7,9-butaoxadecanoic acid (PFO4DA) and perfluoro-3,5,7,9,11-pentaoxadodecanoic acid (PFO5DoA), from gestation days 18-22 across a series of doses (0.3 - 62.5 mg/kg/d) via oral gavage. PFO5DoA was acutely toxic to rat dams and fetuses at the top two doses (30 and 62.5 mg/kg), while PFO4DA did not cause acute toxicity at any doses tested. PFO5DoA significantly increased maternal liver weight (≥3 mg/kg; 28% increase at 10 mg/kg) while PFO4DA did not affect maternal liver weight up to 62.5 mg/kg. PFO4DA and PFO5DoA both significantly reduced serum total thyroxine in maternal (≥10 mg/kg for both) and fetal (≥1 mg/kg) rats. Both compounds significantly reduced fetal liver glycogen concentrations, increased fetal serum total bile acids, and altered expression levels of multiple genes associated with glucose metabolism in the fetal liver. Serum concentrations of PFO5DoA were higher than PFO4DA in both rat dams and fetuses at equivalent maternal oral doses indicating greater accumulation. Dose response modelling of several fetal endpoints as a function of serum molar concentration indicates PFO5DoA was ∼3-4-fold more potent than PFO4DA. PFO5DoA and PFO4DA produced maternal and fetal toxicity from short-term oral maternal exposure indicating need for additional toxicity data to evaluate potential human health risks.

The influence of fetal bovine serum concentration on stemness and neuronal differentiation markers in stem cells from human exfoliated deciduous teeth

Dental Stem Cells (DSCs) from discarded teeth are a non-invasive and ethically favorable source with the potential for neurogenesis due to their ectodermal origin. Stem cells from human exfoliated deciduous teeth (SHED) are particularly promising due to their high differentiation potential and relative immaturity compared to other Mesenchymal Stromal Cells (MSCs). Markers like CD56 and CD271 are critical in identifying MSC subpopulations for therapeutic applications because of their roles in neurodevelopment and maintaining stemness. This study investigates how fetal bovine serum (FBS) concentrations affect the expression of CD56 and CD271 in SHED, influencing their stemness and neuronal differentiation potential. SHEDs were isolated from various donors, cultured, and characterized for MSC traits using markers such as CD14, CD19, CD29, CD34, CD45, CD73, CD90, CD105, CD56, and CD271. Culturing SHED in different FBS conditions (standard 15 %, reduced 1 % and 5 %, and FBS-free) showed that lower FBS concentrations increase CD271 and CD56 expression while maintaining the standard MSC immunophenotype. Importantly, the enhanced expression of these markers can be induced even after SHEDs have been expanded in standard FBS concentrations. These findings suggest that FBS concentration can optimize SHED culture conditions, enhancing their suitability for regenerative medicine and tissue engineering applications.

Developmental neurotoxicity evaluation of acrylamide based on in vitro to in vivo extrapolation by pregnancy PBTK modelling

Acrylamide (ACR) is a known neurotoxicant that can pass the placenta and has been detected in breast milk. Some in vivo and in vitro studies indicate that ACR exposure might lead to developmental neurotoxicity (DNT). Here, we have developed a physiologically-based toxicokinetic model for a pregnant human population using PK-Sim. We performed an in vitro to in vivo extrapolation (IVIVE) of data collected from human neuroblastoma SH-SY5Y cells exposed during differentiation to ACR. The developed PBTK model was successfully evaluated and predicted fetal plasma concentrations in the low nM range after exposing the model to an estimated average daily intake for pregnant women. The IVIVE showed that low concentrations of ACR (fM-nM) that induced attenuated differentiation of the SH-SY5Y neuronal cell model, were relevant for human exposure to ACR from oral intake. However, doses estimated in the IVIVE from concentrations in the µM range, were found to be unrealistic by exposure through food intake for an average daily intake. However, in case of exposure due to environmental pollution or occupational exposure, these concentrations may be reached in fetal plasma. The findings in this study raise the concern regarding ACR exposure during pregnancy as well as the relevance of testing concentrations in vitro that are several orders of magnitude higher than the predicted fetal plasma concentrations.

A Study to Assess the Effectiveness of Structured Teaching Programme on Knowledge Regarding Effect of Caffeinated Food on Fetus among Primigravida Women in Selected Hospitals, Bangalore

A Study was conducted to assess the effectiveness of structured teaching program on knowledge regarding effect of caffeinated food on fetus among primary gravida women in selected hospital, Bangalore. Quasi experimental one group pre-test post-test design (O1 X O2) was adopted for this study. Purposive sampling technique was used to select 60 samples. Structured teaching program was implemented to the primary gravida women for 21 days. Post-test was done after a week of intervention. The data were gathered and analyzed by descriptive and inferential statistical method. The findings revealed that During pretest 17(28.33%) and 43(71.66%) of the samples had inadequate and moderate knowledge respectively. During post-test 48(80%) and 05(8.33%) and 7(11.66%) of samples had moderate, inadequate and adequate knowledge. The paired ‘t’ value for knowledge was 5.25 Which was greater than the table value 1.67 at P ≤ 0.05 level indicating the difference in mean was true difference and structured teaching program was effective in increasing knowledge regarding caffeinated food on fetus among primigravida women. Significant association was found on only family’s annual income hence research hypothesis are retained. Eating a well-balanced diet is crucial for a pregnant women and caffeine has been shown to increase epinephrine concentrations in mother and fetus resulting in decreased placental blood flow and hypoxia.

Alteration of mature neuronal marker of β-III tubulin expression in differentiated SH-SY5Y cells by refinement of foetal bovine serum concentration

BackgroundThe process of differentiating neuroblastoma cells (SH-SY5Y) is crucial for obtaining mature neuronal markers. However, there is variability in the concentrations of foetal bovine serum (FBS) used in the differentiation media, ranging from 1 to 10%. This inconsistency in FBS concentrations may contribute to the inconsistent differentiation of cells. To improve the utility of the SH-SY5Y cell line as a model for neuronal cell culture, we investigated the impact of FBS concentrations in the differentiation media using Dulbecco's modified eagle medium and 10 μM all-trans-retinoic acid (ATRA). The aim of this study was to optimise the concentrations of FBS in the differentiation media of SH-SY5Y cells. Our study focused on assessing the length of dendrites in neuronal cells and the expression of β-III tubulin, a marker indicative of mature neurons. SH-SY5Y cells were differentiated with 10 µM of ATRA for 7 days. Four treatment groups with different FBS concentrations (1%, 3%, 5%, and 10%) were examined to assess the alteration of cellular morphology and dendritic length. The expression of the mature neuron marker β-III tubulin was evaluated using immunocytochemistry technique.ResultsSH-SY5Y cells' dendrite length was significantly longer (p < 0.05) when there was a higher concentration of FBS in the differentiation medium. The result was confirmed with the significant increase of β-III tubulin expression (p < 0.001) of the differentiated SH-SY5Y cells that have been incubated with higher concentrations of FBS in the differentiation medium.ConclusionsWe concluded that optimised concentrations of FBS in the differentiation media display longer length of the dendrites and express higher production of β-III tubulin in the differentiated SH-SY5Y cells. The consistency of serum concentration used in the differentiation media is important to produce a sustainable in vitro neuronal model of SH-SY5Y cells for neurodegenerative studies.

Maternal obesogenic diet during pregnancy and its impact on fetal hepatic function in baboons.

Maternal obesity (MO) increases the risk of later-life liver disease in offspring, especially in males. This may be due to impaired cytochrome P450 (CYP) enzyme activity driven by an altered maternal-fetal hormonal milieu. MO increases fetal cortisol concentrations that may increase CYP activity; however, glucocorticoid receptor (GR)-mediated signaling can be modulated by alternative GR isoform expression. We hypothesized that MO induces sex-specific changes in GR isoform expression and localization that contribute to reduced hepatic CYP activity. Nonpregnant, nulliparous female baboons were assigned to either an ad libitum control diet or a high-fat, high-energy diet (HF-HED) at 9 months pre pregnancy. At 165 days' gestation (term = 180 days), fetal liver samples were collected (n = 6/sex/group). CYP activity was quantified using functional assays, and GR was measured using quantitative RT-PCR and Western blot. CYP3A activity was reduced in the HF-HED group, whereas CYP2B6 activity was reduced in HF-HED males only. Total GR expression was increased in the HF-HED group. Relative nuclear expression of the antagonistic GR isoform GRβ was increased in HF-HED males only. Reduced CYP activity in HF-HED males may be driven in part by dampened hepatic-specific glucocorticoid signaling via altered GR isoform expression. These findings highlight targetable mechanisms that may reduce later-life sex-specific disease risk.

Assessment of Marijuana Use During Pregnancy and its Effects on Neonatal Outcomes

Background: According to the American College of Obstetricians and Gynecologists (ACOG), marijuana is the most used drug during pregnancy, and its self-reported prevalence ranges from ~2% to 7%. ACOG currently recommends against marijuana use during pregnancy due to inconclusive data regarding its safety and health effects. However, we know that THC readily crosses the placenta and can reach high fetal concentrations on repeated exposures. Several reports have linked adverse infant outcomes, such as low birth weight and abnormal neurological development, to marijuana use in pregnancy. Yet, many pregnant women continue to use marijuana throughout gestation as they believe it is safe, highlighting the role that education on marijuana use in pregnancy may aid in decreasing its usage. Furthermore, the growing legalization of marijuana may lead to further increase in marijuana use during pregnancy. Purpose: We aimed to identify the reported use of marijuana during pregnancy in our patient population, prior to legalization, and examine its effects on maternal and neonatal outcomes. We hypothesized that those who reported using marijuana during pregnancy would have higher rates of maternal complications and adverse neonatal outcomes. Methods: A retrospective chart review (IRB #21-823) was conducted which included pregnant women and their neonates who were admitted and delivered in 2019 at HSHS St. John’s Hospital in Springfield, Illinois to assess marijuana use prior to legalization and to investigate neonatal outcomes of infants who were exposed to marijuana, including the need for respiratory support or assisted ventilation after delivery. Other data extracted included demographic characteristics, the mother’s medical and obstetrical history, intrapartum and postpartum events and all documented substance use during pregnancy including tobacco, marijuana and illicit drugs. A logistic regression was used to assess marijuana use as a predictor of respiratory outcomes in infants. Odds ratios with 95% confidence intervals (CI) are reported. Results: In our study, 599 charts were reviewed. Of those, 69 reported marijuana use during pregnancy, or 11.5%, which importantly, is higher than the reported national average of 2-7%. Previous studies have shown a high correlation between marijuana, tobacco and illicit drug use. Additionally, studies have demonstrated that tobacco and illicit drug use result in poor neonatal outcomes. Therefore, we focused on a subpopulation of mothers who only reported marijuana use during pregnancy to remove these confounders. As a result, 112 subjects were removed from the analysis who reportedly used tobacco and/or other illicit drugs in addition to marijuana in order to exclusively focus on the effect of maternal marijuana use on neonatal outcomes. In this subpopulation of 477 subjects, the rate of marijuana use was 5.5% (lower than the overall population), but the effects of marijuana on neonatal outcomes was found to be significant. Demographics were as follows: mean age 28.2 ± 0.25 years; race, ethnicity: 76% White, non-Hispanic and 23% were other (i.e., African American/black, Asian, native Hawaiian/pacific islander, white and Hispanic, non-white and Hispanic or another race). In this subpopulation, admission to the NICU and small for gestational age were not significantly different between marijuana users and non-users. However, marijuana users did have higher odds of preterm birth (OR=3.8, CI: 1.5-9.6; p=0.004). Additionally, marijuana users had increased odds of having an infant that required respiratory support (OR=3.9, CI: 1.4-10.3; p=0.005) and assisted ventilation (OR=4.6, CI: 1.6-13.1; p=0.003). Yet, no adverse maternal outcomes were associated with exclusive marijuana use. Conclusion: Rates of marijuana use during pregnancy in our population is higher than the reported national average. Moreover, infants whose mothers exclusively used marijuana during pregnancy experienced higher rates of neonatal complications. Thorough screening and counseling regarding marijuana use in pregnancy and during breastfeeding is recommended, although there is no uniform process at this time. Implementing a standardized screening methodology and approach to education on the adverse neonatal effects of marijuana use in pregnancy during prenatal visits may be an effective intervention to improve neonatal outcomes in our patient population. This education is of particular importance in light of the recent legalization of marijuana.

Metformin use in pregnancy: What about long-term effects in offspring?

Metformin use in pregnancy is increasing worldwide. Unlike insulin, metformin crosses the placenta. Consequently, maternal and fetal concentrations are comparable. Teratogenic effects are not reported, nor are adverse pregnancy outcomes. Reduced risk of hypertensive disorders, hypoglycemia, and macrosomia are potential benefits, together with lower gestational weight gain. Although metformin has been prescribed for pregnant women during the last 40 years, long-term data regarding offspring outcomes are still lacking. Independent of maternal glycemic control, recent meta-analyses report lower birthweight but accelerated postnatal growth and higher body mass index in metformin-exposed children. The longest follow-up study of placebo-controlled metformin exposure in utero found an increased prevalence of central adiposity and obesity among children 5-10 years old. Recently, a Danish study reported a threefold increased risk of genital anomalies in boys, whose fathers used metformin around the time of conception. This commentary addresses the current controversies on metformin use in pregnancy.

IGF-1 infusion increases growth in fetal sheep when euinsulinemia is maintained.

Insulin-like growth factor 1 (IGF-1) is a critical fetal anabolic hormone. IGF-1 infusion to the normally growing sheep fetus increases the weight of some organs but does not consistently increase body weight. However, IGF-1 infusion profoundly decreases fetal plasma insulin concentrations, which may limit fetal growth potential. In this study, normally growing late-gestation fetal sheep received an intravenous infusion of either: IGF-1 (IGF), IGF-1 with insulin and dextrose to maintain fetal euinsulinemia and euglycemia (IGF+INS), or vehicle control (CON) for 1 week. The fetus underwent a metabolic study immediately prior to infusion start and after 1 week of the infusion to measure uterine and umbilical uptake rates of nutrients and oxygen. IGF+INS fetuses were 23% heavier than CON (P = 0.0081) and had heavier heart, liver, and adrenal glands than IGF and CON (P < 0.01). By design, final fetal insulin concentrations in IGF were 62% and 65% lower than IGF+INS and CON, respectively. Final glucose concentrations were similar in all groups. IGF+INS had lower final oxygen content than IGF and CON (P < 0.0001) and lower final amino acid concentrations than CON (P = 0.0002). Final umbilical oxygen uptake was higher in IGF+INS compared to IGF and CON (P < 0.05). Final umbilical uptake of several essential amino acids was higher in IGF+INS compared to CON (P < 0.05). In summary, maintaining euinsulinemia and euglycemia during fetal IGF-1 infusion is necessary to maximally support body growth. We speculate that IGF-1 and insulin stimulate placental nutrient transport to support fetal growth.

Optimization of the betamethasone and dexamethasone dosing regimen during pregnancy: a combined placenta perfusion and pregnancy physiologically based pharmacokinetic modeling approach

BackgroundAntenatal betamethasone and dexamethasone are prescribed to women who are at high risk of premature birth to prevent neonatal respiratory distress syndrome. The current treatment regimens, effective to prevent neonatal RDS, may be suboptimal. Recently, concerns have been raised regarding possible adverse long-term neurological outcomes due to high fetal drug exposures. Data from non-human primates and sheep suggest maintaining a fetal plasma concentration above 1 ng/mL for 48 hours to retain efficacy, while avoiding undesirable high fetal plasma levels. ObjectiveWe aimed to re-evaluate the current betamethasone and dexamethasone dosing strategies to assess estimated fetal exposure and provide new dosing proposals that meet the efficacy target but avoid excessive peak exposures. Study designA pregnancy physiologically-based pharmacokinetic model was used to predict fetal drug exposures. To allow prediction of the extent of betamethasone and dexamethasone exposure in the fetus, placenta perfusion experiments were conducted to determine placental transfer. Placental transfer rates were integrated in the PBPK model to predict fetal exposure and model performance was verified using published maternal and fetal PK data. The verified pregnancy physiologically-based pharmacokinetic models were then used to simulate alternative dosing regimens to establish a model-informed dose. ResultsEx vivo data showed that both drugs extensively cross the placenta. For betamethasone 15.7 ± 1.7% and for dexamethasone 14.4 ± 1.5% of the initial maternal perfusate concentration reached the fetal circulations at the end of the 3-hour perfusion period. Pregnancy physiologically-based pharmacokinetic models that include these ex vivo-derived placental transfer rates, accurately predicted maternal and fetal exposures resulting from current dosing regimens. The dose simulations suggest that for betamethasone intramuscular a dose reduction from 2 dosages 11.4 mg, 24 hours apart, to 4 dosages 1.425 mg, 12 hours apart would avoid excessive peak exposures and still meet the fetal response threshold. For dexamethasone, the dose may be reduced from four times 6 mg every 12 hours to 8 times 1.5 mg every 6 hours. ConclusionA combined placenta perfusion and pregnancy physiologically-based pharmacokinetic modeling approach adequately predicted both maternal and fetal drug exposures of two antenatal corticosteroids. Strikingly, our PBPK simulations suggest that drug doses might be reduced drastically to still meet earlier proposed efficacy targets and minimize peak exposures. We propose the provided model-informed dosing regimens are used to support further discussion on an updated antenatal corticosteroid scheme and design of clinical trials to confirm the effectiveness and safety of lower doses.

Evaluation of Various Approaches to Estimate Transplacental Clearance of Vancomycin for Predicting Fetal Concentrations using a Maternal-Fetal Physiologically Based Pharmacokinetic Model.

Evaluating drug transplacental clearance is vital for forecasting fetal drug exposure. Ex vivo human placenta perfusion experiments are the most suitable approach for this assessment. Various in silico methods are also proposed. This study aims to compare these prediction methods for drug transplacental clearance, focusing on the large molecular weight drug vancomycin (1449.3g/mol), using maternal-fetal physiologically based pharmacokinetic (m-f PBPK) modeling. Ex vivo human placenta perfusion experiments, in silico approaches using intestinal permeability as a substitute (quantitative structure property relationship (QSPR) model and Caco-2 permeability in vitro-in vivo correlation model) and midazolam calibration model with Caco-2 scaling were assessed for determining the transplacental clearance (CLPD) of vancomycin. The m-f PBPK model was developed stepwise using Simcyp, incorporating the determined CLPD values as a crucial input parameter for transplacental kinetics. The developed PBPK model of vancomycin for non-pregnant adults demonstrated excellent predictive performance. By incorporating the CLPD parameterization derived from ex vivo human placenta perfusion experiments, the extrapolated m-f PBPK model consistently predicted maternal and fetal concentrations of vancomycin across diverse doses and distinct gestational ages. However, when the CLPD parameter was derived from alternative prediction methods, none of the extrapolated maternal-fetal PBPK models produced fetal predictions in line with the observed data. Our study showcased that combination of ex vivo human placenta perfusion experiments and m-f PBPK model has the capability to predict fetal exposure for the large molecular weight drug vancomycin, whereas other in silico approaches failed to achieve the same level of accuracy.

Exagamglogene Autotemcel for Transfusion-Dependent β-Thalassemia

BackgroundExagamglogene autotemcel (exa-cel) is a nonviral cell therapy designed to reactivate fetal hemoglobin synthesis through ex vivo clustered regularly interspaced short palindromic repeats (CRISPR)–Cas9 gene editing of the erythroid-specific enhancer region of BCL11A in autologous CD34+ hematopoietic stem and progenitor cells (HSPCs).MethodsWe conducted an open-label, single-group, phase 3 study of exa-cel in patients 12 to 35 years of age with transfusion-dependent β-thalassemia and a β0/β0, β0/β0-like, or non–β0/β0-like genotype. CD34+ HSPCs were edited by means of CRISPR-Cas9 with a guide mRNA. Before the exa-cel infusion, patients underwent myeloablative conditioning with pharmacokinetically dose-adjusted busulfan. The primary end point was transfusion independence, defined as a weighted average hemoglobin level of 9 g per deciliter or higher without red-cell transfusion for at least 12 consecutive months. Total and fetal hemoglobin concentrations and safety were also assessed.ResultsA total of 52 patients with transfusion-dependent β-thalassemia received exa-cel and were included in this prespecified interim analysis; the median follow-up was 20.4 months (range, 2.1 to 48.1). Neutrophils and platelets engrafted in each patient. Among the 35 patients with sufficient follow-up data for evaluation, transfusion independence occurred in 32 (91%; 95% confidence interval, 77 to 98; P<0.001 against the null hypothesis of a 50% response). During transfusion independence, the mean total hemoglobin level was 13.1 g per deciliter and the mean fetal hemoglobin level was 11.9 g per deciliter, and fetal hemoglobin had a pancellular distribution (≥94% of red cells). The safety profile of exa-cel was generally consistent with that of myeloablative busulfan conditioning and autologous HSPC transplantation. No deaths or cancers occurred.ConclusionsTreatment with exa-cel, preceded by myeloablation, resulted in transfusion independence in 91% of patients with transfusion-dependent β-thalassemia. (Supported by Vertex Pharmaceuticals and CRISPR Therapeutics; CLIMB THAL-111 ClinicalTrials.gov number, NCT03655678.)

Targeted Linked-Read Sequencing for Direct Haplotype Phasing of Parental GJB2/SLC26A4 Alleles: A Universal and Dependable Noninvasive Prenatal Diagnosis Method Applied to Autosomal Recessive Nonsyndromic Hearing Loss in At-Risk Families

Noninvasive prenatal diagnosis (NIPD) for autosomal recessive nonsyndromic hearing loss (ARNSHL) has been rarely reported until recent years. Additionally, the existing method can not be used for challenging genome loci (eg, copy number variations, deletions, inversions, or gene recombinants) or on families without proband genotype. This study assessed the performance of relative haplotype dosage analysis (RHDO)-based NIPD for identifying fetal genotyping in pregnancies at risk of ARNSHL. Fifty couples carrying pathogenic variants associated with ARNSHL in either GJB2 or SLC26A4 were recruited. The RHDO-based targeted linked-read sequencing combined with whole gene coverage probes was used to genotype the fetal cell-free DNA of 49 families who met the quality control standard. Fetal amniocyte samples were genotyped using invasive prenatal diagnosis (IPD) to assess the performance of NIPD. The NIPD results showed 100% (49/49) concordance with those obtained through IPD. Two families with copy number variation and recombination were also successfully identified. Sufficient specific informative single-nucleotide polymorphisms for haplotyping, as well as the fetal cell-free DNA concentration and sequencing depth, are prerequisites for RHDO-based NIPD. This method has the merits of covering the entire genes of GJB2 and SLC26A4, qualifying for copy number variation and recombination analysis with remarkable sensitivity and specificity. Therefore, it has clinical potential as an alternative to traditional IPD for ARNSHL.

In silico modeling for ex vivo placenta perfusion of nicotine.

Nicotine readily crosses the placenta to reach fetuses. However, membrane transporters, e.g., organic cation transporters (OCTs) play a role in the clearance of nicotine from the fetal to the maternal side, and this is rarely investigated clinically. In this work, we use an in silico model to simulate an ex vivo placenta perfusion experiment, which is the gold standard for measuring the transplacental permeability of compounds, including nicotine. The model consists of a system of seven ordinary differential equations (ODEs), where each equation represents the nicotine concentration in compartments that emulate the ex vivo experiment setup. The transport role of OCTs is simulated bi-directionally at the placenta's basal membrane (the fetal side). We show that the model can not only reproduce the actual ex vivo experiment results, but also predict the likely maternal and fetal nicotine concentrations when the OCT transporters are inhibited, which leads to a ∼12% increase in fetal nicotine concentration after 2hours of OCT modulated nicotine perfusion. In conclusion, a first in silico model is proposed in this paper that can be used to simulate some subtle features of trans-placental properties of nicotine.

First Results on the Presence of Mycotoxins in the Liver of Pregnant Fallow Deer (Dama dama) Hinds and Fetuses.

Reproductive abnormalities have been observed in fallow deer populations in Hungary. We supposed mycotoxin contamination to be one of the possible causes because multi-mycotoxin contamination is known to be dangerous even at low toxin levels, especially for young animals. We investigated the spatial pattern of mycotoxin occurrences and the relationship between maternal and fetal mycotoxin levels. A total of 72 fallow deer embryos and their mothers were sampled in seven forested regions in Hungary in the 2020/2021 hunting season. We analyzed Aflatoxin (AF), Zearalenone (ZEA), Fumonizin B1 (FB1), DON, and T2-toxin concentrations in maternal and fetal livers by ELISA. AF was present in 70% and 82%, ZEA in 41% and 96%, DON in 90% and 98%, T2-toxin in 96% and 85%, and FB1 in 84% and 3% of hind and fetus livers, respectively. All mycotoxins passed into the fetus, but only Fumonizin B1 rarely passed. The individual variability of mycotoxin levels was extremely high, but the spatial differences were moderate. We could not prove a relation between the maternal and fetal mycotoxin concentrations, but we found an accumulation of ZEA and DON in the fetuses. These results reflect the possible threats of mycotoxins to the population dynamics and reproduction of wild fallow deer.

The role of fetal hemoglobin in the artificial placenta: A premature ovine model.

A radical paradigm shift in the treatment of premature infants failing conventional treatment is to recreate fetal physiology using an extracorporeal Artificial Placenta (AP). The aim of this study is to evaluate the effects of changing fetal hemoglobin percent (HbF%) on physiology and circuit function during AP support in an ovine model. Extremely premature lambs (n = 5) were delivered by cesarean section at 117-121 d estimated gestational age (EGA) (term = 145d), weighing 2.5 ± 0.35kg. Lambs were cannulated using 10-14Fr cannulae for drainage via the right jugular vein and reinfusion via the umbilical vein. Lambs were intubated and lungs were filled with perfluorodecalin to a meniscus with a pressure of 5-8cm H2O. The first option for transfusion was fetal whole blood from twins followed by maternal red blood cells. Arterial blood gases were used to titrate AP support to maintain fetal blood gas values. The mean survival time on circuit was 119.6 ± 39.5h. Hemodynamic parameters and lactate were stable throughout. As more adult blood transfusions were given to maintain hemoglobin at 10mg/dL, the HbF% declined, reaching 40% by post operative day 7. The HbF% was inversely proportional to flow rates as higher flows were required to maintain adequate oxygen saturation and perfusion. Transfusion of adult blood led to decreased fetal hemoglobin concentration during AP support. The HbF% was inversely proportional to flow rates. Future directions include strategies to decrease the priming volume and establishing a fetal blood bank to have blood rich in HbF.