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 2 hours 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.

Congenital SARS-CoV-2 Infection in Two Neonates with Confirmation by Viral Culture of the Placenta in One Case

Congenital infections with SARS-CoV-2 are uncommon. We describe two confirmed congenital SARS-CoV-2 infections using descriptive, epidemiologic and standard laboratory methods and in one case, viral culture. Clinical data were obtained from health records. Nasopharyngeal (NP) specimens, cord blood and placentas when available were tested by reverse transcriptase real-time PCR (RT-PCR). Electron microscopy and histopathological examination with immunostaining for SARS-CoV-2 was conducted on the placentas. For Case 1, placenta, umbilical cord, and cord blood were cultured for SARS-CoV-2 on Vero cells. This neonate was born at 30 weeks, 2 days gestation by vaginal delivery. RT-PCR tests were positive for SARS-CoV-2 from NP swabs and cord blood; NP swab from the mother and placental tissue were positive for SARS-CoV-2. Placental tissue yielded viral plaques with typical morphology for SARS-CoV-2 at 2.8 × 10² pfu/mL confirmed by anti-spike protein immunostaining. Placental examination revealed chronic histiocytic intervillositis with trophoblast necrosis and perivillous fibrin deposition in a subchorionic distribution. Case 2 was born at 36 weeks, 4 days gestation. RT-PCR tests from the mother and infant were all positive for SARS-CoV-2, but placental pathology was normal. Case 1 may be the first described congenital case with SARS-CoV-2 cultivated directly from placental tissue.

SARS-CoV-2 Transplacental Transmission: A Rare Occurrence? An Overview of the Protective Role of the Placenta

The outbreak of the coronavirus disease 2019 (COVID-19) pandemic, caused by novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has resulted in a global public health crisis, causing substantial concern especially to the pregnant population. Pregnant women infected with SARS-CoV-2 are at greater risk of devastating pregnancy complications such as premature delivery and stillbirth. Irrespective of the emerging reported cases of neonatal COVID-19, reassuringly, confirmatory evidence of vertical transmission is still lacking. The protective role of the placenta in limiting in utero spread of virus to the developing fetus is intriguing. The short- and long-term impact of maternal COVID-19 infection in the newborn remains an unresolved question. In this review, we explore the recent evidence of SARS-CoV-2 vertical transmission, cell-entry pathways, placental responses towards SARS-CoV-2 infection, and its potential effects on the offspring. We further discuss how the placenta serves as a defensive front against SARS-CoV-2 by exerting various cellular and molecular defense pathways. A better understanding of the placental barrier, immune defense, and modulation strategies involved in restricting transplacental transmission may provide valuable insights for future development of antiviral and immunomodulatory therapies to improve pregnancy outcomes.

Trypanosoma cruzi Isolates Naturally Adapted to Congenital Transmission Display a Unique Strategy of Transplacental Passage

Chagas disease is mainly transmitted by vertical transmission (VT) in nonendemic areas and in endemic areas where vector control programs have been successful. For the present study, we isolated natural Trypanosoma cruzi strains vertically transmitted through three generations and proceeded to study their molecular mechanism of VT using mice. No parasitemia was detected in immunocompetent mice, but the parasites were able to induce an immune response and colonize different organs. VT experiments revealed that infection with different strains did not affect mating, pregnancy, or resorption, but despite low parasitemia, VT strains reached the placenta and resulted in higher vertical transmission rates than strains of either moderate or high virulence. While the virulent strain modulated more than 2,500 placental genes, VT strains modulated 150, and only 29 genes are shared between them. VT strains downregulated genes associated with cell division and replication and upregulated immunomodulatory genes, leading to anti-inflammatory responses and tolerance. The virulent strain stimulated a strong proinflammatory immune response, and this molecular footprint correlated with histopathological analyses. We describe a unique placental response regarding the passage of T. cruzi VT isolates across the maternal-fetal interphase, challenging the current knowledge derived mainly from studies of laboratory-adapted or highly virulent strains. IMPORTANCE The main findings of this study are that we determined that there are Trypanosoma cruzi strains adapted to transplacental transmission and completely different from the commonly used laboratory reference strains. This implies a specific strategy for the vertical transmission of Chagas disease. It is impressive that the strains specialized for vertical transmission modify the gene expression of the placenta in a totally different way than the reference strains. In addition, we describe isolates of T. cruzi that cannot be transmitted transplacentally. Taken together, these results open up new insights into the molecular mechanisms of this insect vector-independent transmission form.

Possible Routes for Zika Virus Vertical Transmission in Human Placenta: A Comprehensive Review

Zika virus (ZIKV) infections have gained notoriety due to congenital abnormalities. Pregnant women have a greater risk of ZIKV infection and consequent transmission to their progeny due to the immunological changes associated with pregnancy. ZIKV has been detected in amniotic fluid, as well as in fetal and neonatal tissues of infected pregnant women. However, the mechanism by which ZIKV reaches the fetus is not well understood. The four dengue virus serotypes have been the most widely used flaviviruses to elucidate the host-cell entry pathways. Nevertheless, it is of increasing interest to understand the specific interaction between ZIKV and the host cell, especially in the gestation period. Herein, the authors describe the mechanisms of prenatal vertical infection of ZIKV based on results from in vitro, in vivo, and ex vivo studies, including murine models and nonhuman primates. It also includes up-to-date knowledge from ex vivo and natural infections in pregnant women explaining the vertical transmission along four tracks: transplacental, paracellular, transcytosis mediated by extracellular vesicles, and paraplacental route and the antibody-dependent enhancement process. A global understanding of the diverse pathways used by ZIKV to cross the placental barrier and access the fetus, along with a better comprehension of the pathogenesis of ZIKV in pregnant females, may constitute a fundamental role in the design of antiviral drugs to reduce congenital disabilities associated with ZIKV.

A Five-Week-Old Twin With Profound Anemia: A Case Report of Asymmetric Congenital Babesiosis

We present a case report and review of the literature of congenital transmission of babesiosis in a five-week-old twin neonate evaluated for lethargy and difficulty with feeding. On presentation to the pediatric emergency department, the patient appeared pale and was found to be profoundly anemic with intraerythrocytic ringed parasites consistent with Babesia microti visible on a thin smear. The patient received a blood transfusion and was treated with a regimen of atovaquone and azithromycin with full recovery. The other twin remained asymptomatic with negative Babesia polymerase chain reaction testing.

Reproductive Health Risks Associated with Occupational and Environmental Exposure to Pesticides

A marked reduction in fertility and an increase in adverse reproductive outcomes during the last few decades have been associated with occupational and environmental chemical exposures. Exposure to different types of pesticides may increase the risks of chronic diseases, such as diabetes, cancer, and neurodegenerative disease, but also of reduced fertility and birth defects. Both occupational and environmental exposures to pesticides are important, as many are endocrine disruptors, which means that even very low-dose exposure levels may have measurable biological effects. The aim of this review was to summarize the knowledge collected between 2000 and 2020, to highlight new findings, and to further interpret the mechanisms that may associate pesticides with infertility, abnormal sexual maturation, and pregnancy complications associated with occupational, environmental and transplacental exposures. A summary of current pesticide production and usage legislation is also included in order to elucidate the potential impact on exposure profile differences between countries, which may inform prevention measures. Recommendations for the medical surveillance of occupationally exposed populations, which should be facilitated by the biomonitoring of reduced fertility, is also discussed.

Transplacental Innate Immune Training via Maternal Microbial Exposure: Role of XBP1-ERN1 Axis in Dendritic Cell Precursor Programming

We recently reported that offspring of mice treated during pregnancy with the microbial-derived immunomodulator OM-85 manifest striking resistance to allergic airways inflammation, and localized the potential treatment target to fetal conventional dendritic cell (cDC) progenitors. Here, we profile maternal OM-85 treatment-associated transcriptomic signatures in fetal bone marrow, and identify a series of immunometabolic pathways which provide essential metabolites for accelerated myelopoiesis. Additionally, the cDC progenitor compartment displayed treatment-associated activation of the XBP1-ERN1 signalling axis which has been shown to be crucial for tissue survival of cDC, particularly within the lungs. Our forerunner studies indicate uniquely rapid turnover of airway mucosal cDCs at baseline, with further large-scale upregulation of population dynamics during aeroallergen and/or pathogen challenge. We suggest that enhanced capacity for XBP1-ERN1-dependent cDC survival within the airway mucosal tissue microenvironment may be a crucial element of OM-85-mediated transplacental innate immune training which results in postnatal resistance to airway inflammatory disease.

Alpha-lipoic acid ameliorates cytarabine-induced developmental anomalies in rat fetus

Cytarabine (Ara-C) is a nucleoside analogue used in the treatment of cancers and viral infections. It has teratogenic potential and causes a variety of birth defects in fetuses. Alpha-lipoic acid (ALA) is a natural antioxidant offers protection against the developmental toxicity induced by drug- or toxicant-exposure or pathological conditions. This study was aimed at evaluating the protective effect of ALA against Ara-C induced developmental toxicity in rat fetus. Pregnant rats divided into five groups and received normal saline, ALA200 mg/kg, Ara-C12.5 mg/kg, Ara-C25 mg/kg and, Ara-C25 mg/kg plus ALA200 mg/kg respectively from gestational day (GD) 8 to GD14 and sacrificed on GD21. Ara-C treatment led to a significant and dose-dependent decrease in food intake, weight gain, placental weight, and an increase in oxidative stress in pregnant rats. Further, the in-utero exposure to Ara-C led to an increase in fetal mortality, resorptions, oxidative stress, external morphological anomalies and limb abnormalities, and impaired ossification. Co-administration of ALA resulted in amelioration of the footprints of Ara-C induced toxicity in pregnant rats as well as the fetus. These findings indicate that the ALA supplementation offers protection against developmental toxicity caused by Ara-C prenatal exposure in rats.

Congenital Leishmaniasis in a Newborn Infant Whose Mother was Coinfected With Leishmaniasis and HIV

In utero transmission of Leishmania infantum is the putative mechanism of congenital leishmaniasis. However, this hypothesis is based on limited research. In addition, the consequences for infant newborn development remain to be clarified by additional data. We report here the occurrence, specific management, and monitoring of congenital leishmaniasis in a newborn infant whose mother was coinfected with leishmaniasis and human immunodeficiency virus; transplacental transmission, confirmed by overt clinical disease at birth, was documented, which provides, to our knowledge, the first evidence of hepatic and neurologic impairment in an infant with congenital visceral leishmaniasis.

In Utero Exposure to Benzo[a]pyrene Induces Ovarian Mutations at Doses That Deplete Ovarian Follicles in Mice

Polycyclic aromatic hydrocarbons like benzo[a]pyrene (BaP) are ubiquitous environmental contaminants formed during incomplete combustion of organic materials. Our prior work showed that transplacental exposure to BaP depletes ovarian follicles and increases prevalence of epithelial ovarian tumors later in life. We used the MutaMouse transgenic rodent model to address the hypothesis that ovarian mutations play a role in tumorigenesis caused by prenatal exposure to BaP. Pregnant MutaMouse females were treated with 0, 10, 20, or 40 mg/(kg day) BaP orally on gestational days 7-16, covering critical windows of ovarian development. Female offspring were euthanized at 10 weeks of age; some ovaries with oviducts were processed for follicle counting; other ovaries/oviducts and bone marrow were processed for determination of lacZ mutant frequency (MF). Mutant plaques were pooled within dose groups and sequenced to determine the mutation spectrum. BaP exposure caused highly significant dose-related decreases in ovarian follicles and increases in ovarian/oviductal and bone marrow mutant frequencies at all doses. Absence of follicles, cell packets, and epithelial tubular structures were observed with 20 and 40 mg/(kg day) BaP. Depletion of ovarian germ cells was inversely associated with ovarian MF. BaP induced primarily G > T and G > C transversions and deletions in ovaries/oviducts and bone marrow cells and produced a mutation signature highly consistent with that of tobacco smoking in human cancers. Overall, our results show that prenatal BaP exposure significantly depletes ovarian germ cells, causes histopathological abnormalities, and increases the burden of ovarian/oviductal mutations, which may be involved in pathogenesis of epithelial ovarian tumors. Environ. Mol. Mutagen. 60:410-420, 2019. © 2018 Her Majesty the Queen in Right of Canada.

Mitochondrial DNA, nuclear context, and the risk for carcinogenesis

The inheritance of mitochondrial DNA (mtDNA) from mother to child is complicated by differences in the stability of the mitochondrial genome. Although the germ line mtDNA is protected through the minimization of replication between generations, sequence variation can occur either through mutation or due to changes in the ratio between distinct genomes that are present in the mother (known as heteroplasmy). Thus, the unpredictability in transgenerational inheritance of mtDNA may cause the emergence of pathogenic mitochondrial and cellular phenotypes in offspring. Studies of the role of mitochondrial metabolism in cancer have a long and rich history, but recent evidence strongly suggests that changes in mitochondrial genotype and phenotype play a significant role in the initiation, progression and treatment of cancer. At the intersection of these two fields lies the potential for emerging mtDNA mutations to drive carcinogenesis in the offspring. In this review, we suggest that this facet of transgenerational carcinogenesis remains underexplored and is a potentially important contributor to cancer. Environ. Mol. Mutagen. 60:455-462, 2019. © 2018 Wiley Periodicals, Inc.

Particulate matter-associated micronuclei frequencies in maternal and cord blood lymphocytes

Studies associate particulate matter (PM) exposure with pulmonary, cardiovascular, and neurologic diseases. Elevated levels of coarse (PM10) and fine (PM2.5) PM have been reported in the Mexico City metropolitan area during the last two decades. There is limited information if these conditions affect newborns. We associated maternal exposure to PM reported by the monitoring stations considering the place of residence of each participant with the presence of genotoxic damage (cytome analysis) in maternal and umbilical cord blood (UCB) lymphocytes. Eighty-four healthy women in their last quarter of pregnancy met the inclusion criteria. Each volunteer exposure was estimated according to the average PM2.5 and PM10 levels during the last month of gestation. The micronuclei (MN) frequencies in UCB lymphocyte cultures ranged between 0 and 9. They also showed lower cell proliferation indexes than their mothers. There was a strong correlation between the maternal and the UCB MN frequency (ρ = 0.3767, P = 0.0002). Multiple regression analysis including PM10 and PM2.5 levels, maternal age, and occupation, showed a significant and positive association between UCB MN frequency and PM2.5. A statistically significant increase in the MN frequency in both maternal and UCB lymphocytes was observed in samples obtained during the dry season (higher PM levels) as compared with the MN frequency in blood samples obtained during the rainy season (lower PM levels). These results suggest that PM, mainly PM_2.5 , can cross the placenta causing DNA damage in fetal cells which may increase the potential for diseases during childhood or adult life. Environ. Mol. Mutagen. 60:421-427, 2019. © 2019 Wiley Periodicals, Inc.

Novel multiplex assay for profiling influenza antibodies in breast milk and serum of mother-infant pairs

Background: During early life, systemic protection to influenza is passively provided by transplacental transfer of IgG antibodies and oral and gastrointestinal mucosal protection via breast milk (BM) containing predominantly IgA. Immune imprinting, influenced by initial exposure of the infant immune system to influenza, has recently been recognized as an important determinant of future influenza immune responses. Methods: We utilized stored frozen BM from a prospective birth cohort to assess immune factors in human milk. The earliest available BM and a paired, timed serum sample was assessed from each of  7 mothers. Paired infant serum samples were assayed at up to three time points during the first 12 months of life, one prior to assumed disappearance of transplacentally transferred IgG, and one after. We utilized a novel multiplex assay to assess mothers' and infants' IgG and IgA antibodies in serum to a panel of  30 individual recombinant hemagglutinin (rHA) proteins of influenza virus strains and chimeric rHAs. We also characterized IgA and IgG antibody levels in breast milk which provide mucosal protection. Results: Our pilot results, analyzing a small number of samples demonstrate the feasibility of this method for studying paired maternal-infant IgG and IgA anti-influenza immunity patterns. Unlike IgG antibodies, breast milk influenza virus HA-specific IgA antibody levels and patterns were mostly discordant compared to serum.  As expected, there was a steady decay of infant influenza specific IgG levels by 6 to 8 months of age, which was not, however, comparable in all infants. In contrast, most of the infants showed an increase in IgA responses throughout the first year of life Conclusions:  This new analytical method can be applied in a larger study to understand the impact of maternal imprinting on influenza immunity.

Novel multiplex assay for profiling influenza antibodies in breast milk and serum of mother-infant pairs

Background: During early life, systemic protection to influenza is passively provided by transplacental transfer of IgG antibodies and oral and gastrointestinal mucosal protection via breast milk (BM) containing predominantly IgA. Immune imprinting, influenced by initial exposure of the infant immune system to influenza, has recently been recognized as an important determinant of future influenza immune responses. Methods: We utilized stored frozen BM from a prospective birth cohort to assess immune factors in human milk. The earliest available BM and a paired, timed serum sample was assessed from each of  7 mothers. Paired infant serum samples were assayed at up to three time points during the first 12 months of life, one prior to assumed disappearance of transplacentally transferred IgG, and one after. We utilized a novel multiplex assay to assess mothers' and infants' IgG and IgA antibodies in serum to a panel of  30 individual recombinant hemagglutinin (rHA) proteins of influenza virus strains and chimeric rHAs. We also characterized IgA and IgG antibody levels in breast milk providing mucosal protection. Results: Our pilot results, analyzing a small number of samples demonstrate the feasibility of this method for studying paired maternal-infant IgG and IgA anti-influenza immunity patterns. Unlike IgG antibodies, breast milk influenza virus HA-specific IgA antibody levels and patterns were mostly discordant compared to serum.  As expected, there was a steady decay of infant influenza specific IgG levels by 6 to 8 months of age, which was not, however, comparable in all infants. In contrast, most of the infants showed an increase in IgA responses throughout the first year of life Conclusions:  This new analytical method can be applied in a larger study to understand the impact of maternal imprinting on influenza immunity.

Neuroteratogenic Viruses and Lessons for Zika Virus Models

The Centers for Disease Control and Prevention has confirmed that Zika virus (ZIKV) causes congenital microcephaly. ZIKV now joins five other neuroteratogenic (NT) viruses in humans and ZIKV research is in its infancy. In addition, there is only one other NT human arbovirus (Venezuelan equine encephalitis virus), which is also poorly understood. But further insight into ZIKV can be found by evaluating arboviruses in domestic animals, of which there are at least seven NT viruses, three of which have been well studied. Here we review two key anatomical structures involved in modeling transplacental NT virus transmission: the placenta and the fetal blood-brain barrier. We then survey major research findings regarding transmission of NT viruses for guidance in establishing a mouse model of Zika disease that is crucial for a better understanding of ZIKV transmission and pathogenesis.

Antenatal pharmacokinetics and placental transfer of N-acetylcysteine in chorioamnionitis for fetal neuroprotection

OBJECTIVE

To determine the pharmacokinetics (PK) and placental transfer of intravenous (i.v.) N-acetylcysteine (NAC) in mothers with a clinical diagnosis of chorioamnionitis (CA) and determine the PK of i.v. NAC in their infants.

STUDY DESIGN

In this prospective, double-blind study i.v. NAC 100 mg/kg/dose or saline was administered within 4 hours of CA diagnosis to pregnant women ≥24 weeks' gestation and then every 6 hours until delivery. Maternal PK and placental transfer were determined with maternal blood and matched maternal and cord venous blood. Neonatal PK estimates were determined from i.v. NAC (12.5-25 mg/kg/dose) administered every 12 hours for 5 doses. Noncompartmental analyses were performed for maternal and neonatal PK estimates.

RESULTS

Eleven mothers (5 preterm, 6 near-term) and 12 infants (1 set of twins) received NAC. Maternal clearance (CL) of NAC was faster than in nonpregnant adults, with a terminal elimination half-life of 1.2 ± 0.2 hours. The NAC cord to maternal ratio was 1.4 ± 0.8, suggesting rapid placental transfer and slower rate of fetal CL. Neonatal PK estimates for near-term compared with preterm infants showed a significantly shorter terminal elimination half-life (5.1 vs 7.5 hours, respectively) and greater CL (53.7 vs 45.0 mL/h/kg, respectively).

CONCLUSIONS

Maternal CL and placental transfer of NAC was rapid, with umbilical cord concentrations frequently exceeding maternal concentrations. The administration of NAC to mothers with CA achieves predictable NAC plasma concentrations in the fetus, indicating that antenatal neuroprotection may be possible for these newborns at high risk for neuroinflammation.

Fetal and neonatal thyrotoxicosis

Fetal thyrotoxicosis is a rare disease occurring in 1 out of 70 pregnancies with Grave's disease or in 1 out of 4000-50,000 deliveries. The mortality is 12-20%, usually from heart failure, but other complications are tracheal compression, infections and thrombocytopenia. It results from transfer of thyroid stimulating immunoglobulins from mother to fetus through the placenta. This transplacental transfer begins around 20(th) week of pregnancy and reaches its maximum by 30(th) week. These autoantibodies bind to the fetal thyroid stimulating hormone (TSH) receptors and increase the secretion of the thyroid hormones. The mother has an active autoimmune thyroid disease or has been treated for it in the past. She may be absolutely euthyroid due to past treatment by drugs, surgery or radioiodine ablation, but still have active TSH receptor stimulating autoantibodies, which can cause fetal thyrotoxicosis. The other features of this disease are fetal tachycardia, fetal goiter and history of spontaneous abortions and findings of goiter, ascites, craniosyntosis, fetal growth retardation, maceration and hydrops at fetal autopsy. If untreated, this disease can result in intrauterine death. The treatment for this disease consists of giving carbimazole to the mother, which is transferred through the placenta to the fetus. The dose of carbimazole is titrated with the fetal heart rate. If the mother becomes hypothyroid due to carbimazole, thyroxine is added taking advantage of the fact that very little of thyroxine is transferred across the placenta. Neonatal thyrotoxicosis patients are very sick and require emergency treatment. The goal of the treatment is to normalize thyroid functions as quickly as possible, to avoid iatrogenic hypothyroidism while providing management and supportive therapy for the infant's specific signs and symptoms.

The epigenome as a potential mediator of cancer and disease prevention in prenatal development

Epigenetic events establish a particular gene expression signature for each cell type during differentiation and fertilization. Disruption of these epigenetic programs in response to environmental stimuli during prenatal exposure dysregulates the fetal epigenome, potentially impacting susceptibility to disease later in life (the fetal basis of adult disease). Maternal dietary modifications during gestation and lactation play a pivotal role in the period of fetal (re)programming. Recently, many studies have demonstrated the impact of maternal nutrition on the fetal epigenome. This review discusses the complex interplay among various environmental factors and epigenetic mechanisms that have been found to affect offspring in human and animal models. Further, it summarizes the impact of various dietary phytochemicals capable of modulating the epigenome with regard to diverse human cancers and childhood cancer, specifically those with potential environmental etiology through maternal consumption during pregnancy and lactation. Other dietary agents that are still untested as to their effectiveness in transplacental studies are also discussed. The recent developments discussed herein enhance current understanding of how chemopreventive agents act and their potential to impact the prenatal epigenome; they may also aid efforts to identify dietary interventions that can be beneficial in treating and preventing disease.

Placental transfer of conjugated bisphenol A and subsequent reactivation in the rat fetus

BACKGROUND

Bisphenol A (BPA), a well-known endocrine disruptor, is highly glucuronidated in the liver, and the resultant BPA-glucuronide (BPA-GA) is excreted primarily into bile. However, in rodents, prenatal exposure to low doses of BPA can adversely affect the fetus, despite the efficient drug-metabolizing systems of the dams. The transport mechanisms of BPA from mother to fetus are unknown.

OBJECTIVES

To test our hypothesis that BPA-GA-an inactive metabolite-is passed through the placenta to the fetus, where it affects the fetus after reactivation, we investigated the placental transfer of BPA-GA and reactivation to BPA in the fetus.

METHODS

After performing uterine perfusion with BPA-GA in pregnant rats, we examined the expression and localization of the placental transporters for drug metabolites in the perfusate by reverse-transcriptase polymerase chain reaction and immunohistochemistry. We also investigated the deconjugation of BPA-GA in the fetus and examined uridine 5 -diphospho-glucuronosyltransferase (UGT) activity toward BPA and the expression of UGT isoforms in fetal liver.

RESULTS

We detected BPA-GA and deconjugated BPA in the fetus and amniotic fluid after perfusion. In the trophoblast cells, organic anion-transporting polypeptide 4a1 (Oatp4a1) was localized on the apical membrane, and multidrug resistance-associated protein 1 (Mrp1) was localized to the basolateral membrane. We observed deconjugation of BPA-GA in the fetus; furthermore, we found the expression of UGT2B1, which metabolizes BPA, to be quite low in the fetus.

CONCLUSIONS

These results demonstrate that BPA-GA is transferred into the fetus and deconjugated in the fetus because of its vulnerable drug-metabolizing system.

Arsenic exposure in utero and nonepidermal proliferative response in adulthood in Tg.AC mice

To expand our knowledge on the transplacental carcinogenic potential of inorganic arsenic, pregnant Tg.AC mice received drinking water with 0, 42.5, or 85 ppm arsenite from gestation day 8 to 18. After birth, groups (n = 25) of offspring received topical 12-O-tetradecanoyl phorbol-13-acetate (TPA) (2 microg twice a week) for 36 weeks and were killed; nonskin tumors were assessed. Arsenic increased adrenal cortical adenomas (ACAs; 25%-29%) compared with control (0%) independent of TPA in all male groups. Arsenic increased urinary bladder (UB) hyperplasia in males, but only with TPA. Arsenic induced ACAs in all female groups (control 0%; arsenic 17%-26%). Arsenic-treated females had UB hyperplasia in most groups (control 0%; arsenic 26%-32%), with 2 UB papillomas. All arsenic-treated females had uterine hyperplasia (26%-40%; control 4%) independent of TPA, and 3 had uterine tumors. Thus, arsenic in utero rapidly induces ACAs and uterine and UB preneoplasias in Tg.AC mice, showing transplacental carcinogenic potential in yet another strain of mice.

The study transplacental chikungunya virus antibody kinetics, Thailand

Antibodies to chikungunya virus were detected by hemagglutination-inhibition assay in 33.6% of 2,000 infants' cord sera at delivery. Follow-up of 24 seropositive infants showed that the half-life of antibody persistence was 35.5 days. Chikungunya virus infection is common in Thailand, and routine use of diagnostic assays is needed.