The Left Outflow Tract in Fetal Cardiac Screening Examination: Introduction of Quality Criteria Is Not Always Associated With an Improvement of Practice When Supervised by Humans.

OBJECTIVES: Since 2016, the French CNEOF included the left ventricular outflow tract (LVOT) in the second and third trimester of pregnancy in addition to the four-chamber view and the parasagittal view of the right outflow tract. The objective of this study was to define quality criteria for fetal LVOT assessment and to perform a human audit of past and current practices, before and after the implementation of those quality criteria at a large scale. METHODS: Seven quality criteria were investigated and rated from 0 to 1 during three periods of interest. Files were randomly selected from three centers, and average total and specific scores were calculated. RESULTS: LVOT pictures were present in more than 94.3% of reports. The average quality score was 5.49/7 (95% confidence interval [CI]: 5.36-5.62), 5.91/7 (95% CI: 5.80-6.03), and 5.70/7 (95% CI: 5.58-5.82) for the three centers in the three periods of interest. There was no significant difference following the introduction of the quality criteria, 2017 versus 2020, P = .054. CONCLUSION: Fetal LVOT images were present in most of ultrasound reports but the introduction of the proposed quality criteria under human supervision seems not associated with a significant change in practice.

Use of Remifentanil Associated with Lidocaine for Feticides in Late Terminations of Pregnancy: A Randomized Clinical Trial.

INTRODUCTION: In France, performance of a termination of pregnancy is legally possible without any gestational age limit. After 22 weeks of gestation, a feticide is ethically performed using usually sufentanil and lidocaine. The aim of this study was to compare the use of remifentanil, a fast-acting morphine-derivating product, instead of sufentanil. METHODS: This 2-center randomized, controlled, single-blinded phase-III treatment trial had 2 parallel arms: an experimental group using remifentanil with lidocaine versus a control group receiving sufentanil associated with lidocaine. This trial took place over a 40-month period. The primary outcome was time to fetal asystole after lidocaine injection. The secondary outcome measures were the procedure's success rate, the rate of serious maternal side effects, and the presence of cellular or tissue modifications. RESULTS: The study included 66 women, randomized into 2 groups of similar size and characteristics. Time to fetal asystole did not differ significantly between the groups, with a delay of 4 min (Q1-Q3, 2-11) in the sufentanil group and 4 min (Q1-Q3, 1-10) in the remifentanil group (p = 0.84). Similarly, the success rate of the procedure did not differ significantly. Fetal asystole was procured in <2 min and persisted >1 min for 16 (25.8%) women in our total population: 7 (22.5%) in the sufentanil group and 9 (29.0%) in the remifentanil group, p = 0.77. No severe maternal side effects were observed. Among the 49 fetopathological examinations performed, the few tissue and cell modifications observed did not cause any interpretation difficulties in either group. DISCUSSION/CONCLUSION: Use of remifentanil instead of sufentanil for feticide procedure did not improve time to fetal asystole. No harmful effect was observed for either maternal tolerance or interpretation of the histologic slides.

A score-based method for quality control of fetal hard palate assessment during routine second-trimester ultrasound examination.

INTRODUCTION: When an orofacial cleft lip is discovered, precise characterization of this malformation is necessary, especially the extension of this cleft to the secondary palate. We aimed to develop and evaluate the feasibility/reproducibility of a score-based quality control for the visualization of the fetal hard palate during the second-trimester scan. MATERIAL AND METHODS: All ultrasound images of fetal hard palate assessed routinely during second-trimester scan were retrospectively retrieved for a 6-month period. One hundred of these images were randomly selected and analyzed by two blinded reviewers, according to a scoring system (0-6 points). Criteria retained in the score were complete palate bone horizontal plate, presence of two pterygoid processes, visible alveolar ridge, and horizontal axis of insonation. A score ≥4 defined images of good quality. Inter- and intra-reviewer reproducibility was assessed. RESULTS: Inter-reviewer reproducibility was excellent with significant correlation (Pearson coefficient 0.953; P < .0001), global adjusted κ coefficient (0.86, 95% CI 0.79-0.94) and individual criteria adjusted κ coefficient always > 0.8. Rates of images of good quality (score ≥ 4) were 75%-77%, also with excellent agreement (κ coefficient 0.89, 95% CI 0.79-0.99). Intra-reviewer reproducibility retrieved the same results (excellent agreement) except for the axis of insonation (satisfactory agreement). CONCLUSIONS: This simple image scoring system for the fetal palate is easy, has excellent inter- and intra-reviewer reproducibility and could also help sonographers to correctly identify the palate structure.

Réunion Island prepared for possible Zika virus emergence, 2016.

Zika virus (ZIKV) has recently spread widely and turned into a major international public health threat. Réunion appears to offer conditions particularly favourable to its emergence and therefore prepared to face possible introduction of the virus. We designed a scaled surveillance and response system with specific objectives, methods and measures for various epidemiological phases including a potential epidemic. Several tools were developed in order to (i) detect individual cases (including a large information campaign on the disease and suspicion criteria), (ii) monitor an outbreak through several complementary systems allowing to monitor trends in disease occurrence and geographic spread and (iii) detect severe forms of the disease in collaboration with hospital clinicians. We put the emphasis on detecting the first cases in order to contain the spread of the virus as much as possible and try to avoid progress towards an epidemic. Our two main strengths are a powerful vector control team, and a close collaboration between clinicians, virologists, epidemiologists, entomologists and public health authorities. Our planned surveillance system could be relevant to Europe and island settings threatened by Zika virus all over the world.

Does prenatal MRI enhance fetal diagnosis of intra-abdominal cysts?

OBJECTIVE: The aim of this study was to evaluate the contribution of prenatal magnetic resonance imaging (MRI) to ultrasound (US) in the prenatal diagnosis of intra-abdominal cystic masses, correlated with the postnatal diagnosis. METHODS: In this retrospective, observational study, prenatal MRI and US diagnoses were compared with postnatal diagnoses. MRI was performed in 56 fetuses with intra-abdominal cyst diagnosed by US between 2004 and 2013. Final diagnosis, revealed by postnatal evaluation, was obtained for 49 of them and was taken as the reference. MRI was evaluated as superior, equal, or inferior to US. RESULTS: An accurate diagnosis was provided by US in 25 cases (51%) and by MRI in 36 out of the 49 cases (73.4%). MRI corrected the US diagnosis in 13 cases (26.5%) by providing a more precise localization or additional etiologic information. In two cases (4%), MRI wrongly changed the diagnosis correctly made by US. CONCLUSION: Prenatal MRI better characterized the nature of abdominal cystic lesions previously diagnosed by US in 13 cases. This enhanced postnatal therapeutic planning and so improved parental counseling and pregnancy management.

Thrombosis of torcular herophili: diagnosis, prenatal management, and outcome.

OBJECTIVES: The objective of this article is to describe and assess prenatal imaging findings, fetal and postnatal outcomes of thrombosis of torcular herophili, and to determine diagnostic features, pathophysiology, prognosis, and optimal management. METHODS: Over a decade, we compiled the largest single-center retrospective study of outcomes. Fetal magnetic resonance imaging (MRI) was used to confirm the sonographic suspicion and monitor thrombosis of torcular herophili. We noted prenatal and postnatal imaging specifications, pregnancy outcomes, and clinical and radiological pediatric monitoring. Analysis of findings and review of the literature allowed us to define prognostic factors. RESULTS: In eight cases of prenatal diagnosis of thrombosis of torcular herophili, MRI outcomes were specific. There were five deliveries at full term, two terminations of pregnancy, and one fetal demise in utero. Neonates had a good clinical and radiological outcome. Factors of poor prognosis were deep venous sinus thrombosis, enduring mass effect, brain parenchymal injury, and heart failure related to dural arteriovenous shunt. CONCLUSION: Among dural sinus malformations, thrombosis of torcular herophili with or without extension at the posterior segment of the longitudinal sinus frequently has a good prognosis. It is urgent to wait because the prognosis can only be ascertained over time by means of ultrasound scan and MRI monitoring.

Prenatal and neonatal phenotype of Larsen of La Réunion Island syndrome (B4GALT7-linkeropathy).

Larsen of La Réunion Island syndrome (LRS) is an autosomal recessive condition associated with multiple large joint dislocations, clubfeet, severe dwarfism, and distinctive facial features. LRS is caused by a recurrent homozygous variant in B4GALT7 gene with a founder effect in La Réunion population. Proteoglycans (PG) that are a major component of the extracellular matrix, are composed of a core protein connected to a glycosaminoglycans side chain via a tetrasaccharide linker region. B4GALT7 encodes galactosyltransferase I, one of the enzymes involved in the biosynthesis of the linker region. Conditions caused by pathogenic biallelic variants in genes implicated in the synthesis of the tetrasaccharide linker of PG are known as linkeropathies. Prenatal features are rarely described in this group of chondrodysplasias. We present a series of 12 unpublished patients having LRS and describe the perinatal phenotype. All the patients had a prenatal growth restriction with brevity of limbs. The other features revealed by ultrasounds were increased nuchal translucency at 10-12 weeks of gestation (50 %), feet abnormalities (clubfeet or metatarsus varus) (25 %), dislocation affecting at least one large joint (elbow, knee, wrist) (25 %). Bilateral bowing of femora was noted for two fetuses. Fibular hypertrophy was noted for one fetus. Prenatal helical computed tomography (CT) performed in three pregnancies showed additional data such as bowing of the forearm bones, proximal radio-ulnar synostosis, or dislocation of large joints. Prenatal sonographic and helical CT findings led to the prenatal diagnosis of LRS in four patients. We confirm that the neonatal clinical picture of LRS has an important overlap with that reported in patients with B4GALT7 deficiency outside La Réunion Island and other linkeropathies. The core of the phenotypic spectrum combines low birth height, micromelia, hypermobility, dislocation of at least one large joint, facial features with prominent eyes, microstomia, depressed nasal bridge, and midface hypoplasia. Other clinical features include clubfeet (33%), bifid thumb in one patient, and cardiac abnormalities in two patients. Radiological findings include radio-ulnar synostosis (75%), metaphyseal flaring, precocious carpal ossification, and a Swedish key appearance of the proximal femora. Finally, we also report radiological features rarely described in B4GALT7-linkeropathies, including bowing of the femora and fibular hypertrophy. Our results confirm the phenotypic continuum of LRS within linkeropathies with some additional findings, including a high frequency of clubfeet usually described in B3GALT6-linkeropathies, the presence of congenital heart diseases usually described in B3GAT3-linkeropathies, and a high frequency of metaphyseal flaring usually reported in B3GALT6 or XITLT1-linkeropathies. This is the first study that describes the perinatal phenotype in a cohort of patients with LRS. This study can help improve the prenatal diagnosis of the linkeropathies and add this group of conditions to the differential diagnosis of chondrodysplasias with multiple dislocations. In view of the founder effect for LRS in La Réunion Island, this disease should be suspected in fetuses with growth restriction and micromelia. Thus in case of LOH which include B4GALT7 identified in SNP-array, we recommend performing a targeted Sanger sequencing for the recurrent mutation c.808C > T; p. (Arg270Cys).

Application of new fetal growth standards in a multiethnic population.

OBJECTIVES: Ultrasound assessment of fetal growth is essential to reduce adverse pregnancy outcomes. Intergrowth-21st developed international standards. Currently, we use in France chart based on Hadlock's formula. This study aims to evaluate, the impact of switching from national curves to IG-21 curves or a combination of IG-21 with Hadlock. METHODS: The study population consisted of 3 697 singleton pregnancies with fetal biometry measured between 22 and 38 weeks of gestation. Z-scores were calculated for each biometry according to CFEF and IG-21. The estimated fetal weight and its Z-score were calculated using the Hadlock formula and IG-21 formula. RESULTS: We observed 21% of head circumference, 9% of abdominal circumference and 7% of femoral length below the 10th centile with Intergrowth-21. Concerning estimated fetal weight, IG-21 classified 13.8% fetuses as SGA, IG-21/Hadlock 10.8% and CFEF 16.1%. Between 36 and 38 weeks of gestation, IG-21 classified more fetuses as SGA than IG-21/Hadlock and CFEF, respectively 18%, 14.1% and 13.3%. CONCLUSION: The use of IG-21 or IG-21/Hadlock in the general population would lower the number of fetuses classified as SGA except for fetuses between 36 and 38 weeks. During this period, many decisions of induced early delivery or specific management are established to prevent adverse perinatal outcome. Those results must be supplemented by a comparison to newborns' weight.

Admission into intensive care unit in preeclampsia: a four-year population-based study in Reunion Island.

INTRODUCTION: Preeclampsia is one of the leading causes of maternal and fetal morbidity and mortality. The objective of our study was to study risk factors and complications associated with severe preeclampsia requiring intensive care unit (ICU) admission. METHODS: Retrospective comparative study over a period from 1st of January 2015 to 1st of January 2019 in the University's maternity unit of South Reunion (Indian Ocean). Our sampling included all preeclamptic patients who delivered in the Southern part of the island. Patients admitted to intensive care unit (ICU) and those who remained in the maternity unit (controls) were reviewed. RESULTS: Out of 482 preeclampsia cases, 94 women (19.5%) needed a transfer in ICU, of which only 21 (4.3%) needed invasive intensive care. Mean length of stay was 2.4 ± 2.1 days. ICU admission was associated with HELLP syndrome (OR 8.5 [4.9-14.9], p<.001), severe post-partum hemorrhage (OR 5.86 [1.29-26.70], p=.01) and early onset of preeclampsia (<34 weeks gestation), 2.97 [1.9-4.7], p<.001), leading to higher rate of C-section (OR 2.83 [1.67-4.78], p<.001). There were three patients with a history of eclampsia and no case of maternal death was reported. Fetal prognosis was much poorer in maternal ICU admissions than in controls, with outcomes including lower birth weight (1776 vs. 2304 g, p<.001) and higher perinatal morbidity (infant respiratory distress syndrome 3.70 [1.94-7.05], p<.001) and mortality (<.001). CONCLUSIONS: Women needing invasive ICU represented 4.3% of preeclampsia cases. This experience is of interest for lower resource settings such as in countries like Madagascar where very intensive ICU means are very poor, but simpler ICU surveillance is possible. Fetal prognosis was poor though no maternal death was reported. Thus, a multidisciplinary approach of patients with preeclampsia should be encouraged; admission into ICU should be facilitated, as soon as any sign of severity and complications appears.

Bis(hydroxyphenyl)methane-bisphenol F-metabolism by the HepG2 human hepatoma cell line and cryopreserved human hepatocytes.

Bisphenol F (BPF) is present in the environment and as a contaminant of food. Humans may, therefore, be exposed to BPF, and an assessment of this risk is required. BPF has been shown to have genotoxic and endocrine-disruptor properties in a human hepatoma cell line (HepG2), which is a model system for studies of xenobiotic toxicity. In this study, we investigated the ability of HepG2 cells to biotransform BPF, because metabolism may affect the observed effects of BPF, and we compared this metabolic capacity with that of human hepatocytes. Cells were incubated for 24 hours with [(3)H]-BPF. The culture medium was then concentrated and its metabolites were isolated by high-performance liquid chromatography and identified by mass spectrometry. BPF was largely metabolized into the corresponding sulfate by the HepG2 cell line. BPF was metabolized into both sulfate and glucuronide by human hepatocytes, but with differences between individuals. The metabolism of BPF in both HepG2 cells and human hepatocytes suggests the existence of a detoxification pathway. Thus, these two cell models differ in metabolic capacity. It is, therefore, very important, when assessing the toxic effects of substances in vitro, to determine, in parallel, the biotransformation capacities of the model used to extrapolate in vivo.

A prospective study evaluating congenital CMV infection in Mayotte and La Reunion Islands (France).

OBJECTIVES Congenital cytomegalovirus infection (cCMV) affects around 3400 newborns each year in France, of whom 700 will develop sequelae, primarily sensorineural hearing loss. Our objectives were (1) to evaluate incidence of cCMV in two French departments located in the Indian Ocean: Mayotte and La Reunion, and (2) evaluate interest and feasibility/acceptability of universal screening of cCMV at birth. MATERIAL AND METHODS We implemented a universal neonatal CMV screening in Mayotte during 7 months in 2019 and in La Reunion during one month in March 2020. Saliva swabs were collected in the first three days of life, and tested for CMV DNA by PCR. A short survey allowed evaluating whether this screening is acceptable and feasible. RESULTS: A total of 1026 newborns were screened: 854 in Mayotte and 172 in La Reunion. In Mayotte, cCMV incidence was evaluated at a minimum of 1.6 % (95 % CI 0.94-2.81). In La Reunion, cCMV incidence was evaluated at a minimum of 1.2 % (95 % CI -0.20-4.57). All cCMV infants were born to mothers with non-primary CMV infection. Only 0.7 % parents refused the screening. CONCLUSIONS cCMV incidence in Mayotte and La Reunion is higher than in metropolitan France. This diagnosis should not be overlooked, especially since the time dedicated to screening and its feeling by the parents seem to be acceptable.

Discordant malformations in monochorionic twins: a retrospective cohort study in La Reunion Island.

Background: Discordant malformation between monochorionic twins is a rare and unknown phenomenon.Objectives: To estimate the incidence of discordant monochorionic twins and to describe their characteristics.Study design: A retrospective multicenter cohort of pregnancies between 2002 and 2015 in La Reunion Island was analyzed, thanks to a population-based register. Only monochorionic pregnancies were included in order to analyze specifically monozygotic twins. We defined as discordant twin pairs those in which different malformations were identified for each twin and those with only one fetus showing a malformation.Results: During the study period, 203,807 births occurred, including 410 monochorionic twin pairs. Congenital anomalies rate for monochorionic twin pairs was 10.7%. We included 38 monochorionic twin pairs with discordant phenotypes, which represent 9.3% of monochorionic twin pairs and 86.4% of monochorionic twin pairs affected by congenital anomalies. Among them, both twins were affected by different congenital anomalies in 7 pairs (18.4%), and only one twin was affected in 31 pairs (81.6%). We identified 20 congenital heart anomalies (44.4%), 5 brain anomalies (11.1%), 5 genital anomalies (11.1%), 4 axial bones and skull anomalies (8.9%), 4 limb anomalies (8.9%), 4 facial anomalies (8.9%), 3 urological anomalies (6.6%), 2 thoracic anomalies (4.4%), 1 bile duct anomaly (2,2%), 1 abdominal parietal defect (2.2%), and 1 aneuploidy (2.2%). Among them, 3 (6.6%) fetuses had an association of malformations. Among the 45 fetuses with malformations, 37 fetuses (82.2%) were born alive and 21 (46.6%) had postnatal surgery.Conclusions: Despite a supposed identical genome, discordant congenital anomalies in monochorionic twin pregnancies are not exceptional and related to genetic and epigenetic mechanisms. Sonographers and pediatricians should know that in monochorionic twin a pair, the occurrence of discordant phenotypes is high (9.3%).

Genotoxic and endocrine activities of bis(hydroxyphenyl)methane (bisphenol F) and its derivatives in the HepG2 cell line.

Human can be exposed to bis(hydroxyphenyl)methane (bisphenol F or BPF) and its derivatives as environment and food's contaminants. This study was investigated to identify and to compare toxic potency of BPF, BFDGE, and two of BPF metabolites using in vitro methods. BPF did not induce any genic mutation in bacteria when the Ames test was performed according to the OECD guideline. In contrast, using Human cell lines and Comet assay, we demonstrated that BPF and Bisphenol F Diglycidyl Ether (BFDGE) were effective on HepG2 cell DNA fragmentation at non-cytotoxic concentrations. DHB was also positive but at higher concentrations, near its limit of solubility. Neither BPF, nor DHB induced a positive response in the micronucleus assay. The increase of micronuclei observed when cells were exposed to BFDGE was mostly due to a cytotoxic effect. Concerning endocrine activities, BPF increased the luciferase activity in HepG2 cells transiently transfected with a concentration dependant pattern, DHB also induced a positive response but at highest concentrations. Estrogenic responses in the HepG2 cells differed with the estrogen receptor (ER) involved. Using MDA-kb2 cell line stably transfected with pMMTV-neo-Luc, only BPF was anti-androgenic at the highest concentration (10(-5)M). Then, we demonstrated using human cell lines, especially HepG2, BPF was the most toxic compound in term of genotoxicity and endocrine activities compared to DHB and BPF-OH, the free metabolites identified in rat urine when BPF was administrated to rats.

Recurrent or first preeclampsia in multiparae: A case-control study of singleton pregnancies in Reunion Island.

Recurrent or first preeclampsia in multiparae : a case-control study of singleton pregnancies in Reunion Island Phuong Lien Tran, Pierre-Yves Robillard, Coralie Dumont, Chloé Schweizer, Asma Omarjee, Glorianne Lazaro, Silvia Iacobelli, Malik Boukerrou OBJECTIVE: To compare multiparous women with a first occurrence of preeclampsia and those with recurrent preeclampsia in singleton pregnancies. STUDY DESIGN: a 17.5-year (2001-2018) case-control study conducted in the University's maternity of South Reunion (Indian Ocean), comparing 125 patients with recurrent preeclampsia and 742 patients with a first episode of the disease (controls). Statistical analyses were performed with use of the Student t-test for comparison of continuous data and the Chi-square or Fisher exact test for comparison of categorical variables. RESULTS: There was no difference between the two groups concerning socio-demographic characteristics, post-partum haemorrhage, perinatal mortality rates. Nevertheless, recurrent preeclamptic women had a higher risk to present with prior chronic hypertension (OR 2.05 [1.30-3.23], p = 0.002), and to experience an early onset preeclampsia (< 34 weeks) compared to controls (OR 1.69 [1.15-2.48], p = 0.007). Women with recurrent preeclampsia were more prone to have C-sections (OR 1.63 [1.06-2.51], p = 0.024) mainly because of maternal indications (89.2% vs 76.4%, p = 0.008). Newborns from recurrent preeclampsia were more likely to have very low birthweight < 1500 g (OR 1.79 [1.16-2.77], p = 0.001), while there was no significant difference for gestational ages (34.1 vs 34.7 weeks). CONCLUSION: Recurrent multiparous preeclamptic women presented more severe maternal disease (with a higher rate of early onset preeclampsia). Persistent hypertension in women with a history of preeclampsia is a risk factor for developing recurrent preeclampsia, and these patients should be monitored more closely.

Recessive loss of function PIGN alleles, including an intragenic deletion with founder effect in La Réunion Island, in patients with Fryns syndrome.

Fryns syndrome (FS) is a multiple malformations syndrome with major features of congenital diaphragmatic hernia, pulmonary hypoplasia, craniofacial dysmorphic features, distal digit hypoplasia, and a range of other lower frequency malformations. FS is typically lethal in the fetal or neonatal period. Inheritance is presumed autosomal recessive. Although no major genetic cause has been identified for FS, biallelic truncating variants in PIGN, encoding a component of the glycosylphosphatidylinositol (GPI)-anchor biosynthesis pathway, have been identified in a limited number of cases with a phenotype compatible with FS. Biallelic variants in PIGN, typically missense or compound missense with truncating, also cause multiple congenital anomalies-hypotonia-seizures syndrome 1 (MCAHS1). Here we report six further patients with FS with or without congenital diaphragmatic hernia and recessive loss of function PIGN alleles, including an intragenic deletion with a likely founder effect in La Réunion and other Indian Ocean islands. Our results support the hypothesis that a spectrum of phenotypic severity is associated with recessive PIGN variants, ranging from FS at the extreme end, caused by complete loss of function, to MCAHS1, in which some residual PIGN function may remain. Our data add FS resulting from PIGN variants to the catalog of inherited GPI deficiencies caused by the disruption of the GPI-anchor biosynthesis pathway.

Analysis of the Local Lymph Node Assay (LLNA) variability for assessing the prediction of skin sensitisation potential and potency of chemicals with non-animal approaches.

The knowledge of the biological mechanisms leading to the induction of skin sensitisation has favoured in recent years the development of alternative non-animal methods. During the formal validation process, results from the Local Lymph Node Assay (LLNA) are generally used as reference data to assess the predictive capacity of the non-animal tests. This study reports an analysis of the variability of the LLNA for a set of chemicals for which multiple studies are available and considers three hazard classification schemes: POS/NEG, GHS/CLP and ECETOC. As the type of vehicle used in a LLNA study is known to influence to some extent the results, two analyses were performed: considering the solvent used to test the chemicals and without considering the solvent. The results show that the number of discordant classifications increases when a chemical is tested in more than one solvent. Moreover, it can be concluded that study results leading to classification in the strongest classes (1A and EXT) seem to be more reliable than those in the weakest classes. This study highlights the importance of considering the variability of the reference data when evaluating non-animal tests.

Estrogen receptor α and aryl hydrocarbon receptor cross-talk in a transfected hepatoma cell line (HepG2) exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin.

The prototype dioxin congener 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is known to exert anti-estrogenic effects via activation of the aryl hydrocarbon receptor (AhR) by interfering with the regulation of oestrogen homeostasis and the estrogen receptor α (ERα) signalling pathway. The AhR/ER cross-talk is considered to play a crucial role in TCDD- and E2-dependent mechanisms of carcinogenesis, though the concerted mechanism of action in the liver is not yet elucidated. The present study investigated TCDD's impact on the transcriptional cross-talk between AhR and ERα and its modulation by 17ß-estradiol (E2) in the human hepatoma cell line HepG2, which is AhR-responsive but ERα-negative. Transient transfection assays with co-transfection of hERα and supplementation of receptor antagonists showed anti-estrogenic action of TCDD via down-regulation of E2-induced ERα signaling. In contrast, enhancement of AhR signaling dependent on ERα was observed providing evidence for increased cytochrome P450 (CYP) induction to promote E2 metabolism. However, relative mRNA levels of major E2-metabolizing CYP1A1 and 1B1 and the main E2-detoxifying catechol-O-methyltransferase were not affected by the co-treatments. This study provides new evidence of a TCDD-activated AhR-mediated molecular AhR/ERα cross-talk mechanism at transcriptional level via indirect inhibition of ERα and enhanced transcriptional activity of AhR in HepG2 cells.

Genotoxic activities of the food contaminant 5-hydroxymethylfurfural using different in vitro bioassays.

5-Hydroxymethylfurfural (5-HMF) is known as an indicator of quality deterioration in a wide range of foods. 5-HMF is formed as an intermediate in the Maillard reaction and has been identified in a wide variety of heat-processed foods. In recent years, the presence of 5-HMF in foods has raised toxicological concerns: data have shown cytotoxic, genotoxic and tumoral effects but further studies suggest that 5-HMF does not pose a serious health risk. However the subject is still a matter of debate. We investigated the genotoxicity of the food-borne contaminant 5-HMF using the Ames test, the micronucleus (MN) and the single-cell gel electrophoresis (SCGE) assays in the human metabolically active HepG2 cell line. Cytotoxic effect of 5-HMF was first assessed using Alamar Blue as a sensitive sub-lethal assay. 5-HMF did not induce any genic mutation in bacteria whatever the concentration in the Ames test. Furthermore, it does not induce clastogenic or aneugenic effects in the HepG2 cells. In contrast, 5-HMF induced HepG2 DNA damage at concentrations from 7.87 to 25 mM in the comet assay suggesting a weak genotoxic effect of 5-HMF in the HepG2 cells probably repaired.