Aryl Hydrocarbon Receptor and Dioxin-Related Health Hazards-Lessons from Yusho.

Poisoning by high concentrations of dioxin and its related compounds manifests variable toxic symptoms such as general malaise, chloracne, hyperpigmentation, sputum and cough, paresthesia or numbness of the extremities, hypertriglyceridemia, perinatal abnormalities, and elevated risks of cancer-related mortality. Such health hazards are observed in patients with Yusho (oil disease in Japanese) who had consumed rice bran oil highly contaminated with 2,3,4,7,8-pentachlorodibenzofuran, polychlorinated biphenyls, and polychlorinated quaterphenyls in 1968. The blood concentrations of these congeners in patients with Yusho remain extremely elevated 50 years after onset. Dioxins exert their toxicity via aryl hydrocarbon receptor (AHR) through the generation of reactive oxygen species (ROS). In this review article, we discuss the pathogenic implication of AHR in dioxin-induced health hazards. We also mention the potential therapeutic use of herbal drugs targeting AHR and ROS in patients with Yusho.

Prenatal Diagnosis of Criss-Cross Heart Using 4-Dimensional Color Doppler Rendering.

Criss-cross heart is a rare congenital cardiac anomaly characterized by the crossing of two ventricular inflow streams. We have demonstrated the utility of 4-dimensional color Doppler rendering in diagnosing the criss-cross heart in a fetus. Four-dimensional color Doppler rendering can demonstrate the relative direction of intracardiac blood flows and facilitate recognition of the crossover of inflow streams in the same plane, confirming the criss-cross heart diagnosis in the fetus.

A rare association of left pulmonary artery sling with right pulmonary hypoplasia and total anomalous pulmonary venous connection.

We present the second reported case of left pulmonary artery sling with dextrocardia, right pulmonary hypoplasia, and total pulmonary venous connection in a fetus. This case highlights the importance of the determination of pulmonary artery arrangement by fetal echocardiography if right pulmonary hypoplasia and/or congenital heart disease is suspected.

Analysis of antenatal-onset cerebral palsy secondary to transient ischemia in utero using a national database in Japan.

AIM: We conducted a retrospective analysis of summary medical reports of children diagnosed with cerebral palsy (CP) to identify clinical features of antenatal onset of CP secondary to transient ischemia in utero. METHODS: The 658 brief summary reports available in the Japan Obstetric Compensation System for Cerebral Palsy were screened, and we identified cases of singleton pregnancy, delivered at gestational age ≥ 33 weeks and those with cord blood gas pH ≥ 7.20. Of the 137 cases identified, 84 were excluded for the following reasons: no evidence of ischemic brain lesion, clear post-natal causative factor of CP, presence of a congenital condition, and sentinel hypoxic event, such as uterine rupture. The demographic profiles of the 53 cases included in our analysis were compared to identify those with and without an abnormal variability in fetal heart rate. RESULTS: Between-group comparison identified an association between abnormal heart rate variability and a lower Apgar score at 1 min (2 vs 6; P < 0.001) and 5 min (5.5 vs 8; P = 0.002), and more frequent episodes of fetal movement loss (41% vs 10%; P = 0.027). An hypoxic event ≤ 1 week before delivery was more likely to be associated with abnormal heart rate variability (89%) and low Apgar score (82%), while events at > 1 week were associated with development of polyhydramnios (44%). CONCLUSION: In utero transient ischemic events can contribute to term or near-term CP. Careful follow-up is recommended for fetuses with a history of fetal movement loss, abnormal variability in heart rate, and polyhydramnios of unknown causes.

[Relationships between Half-Lives of Dioxins and SNPs in AhR among Yusho Patients].

Half-lives of blood levels of 2,3,4,7,8-Pentachlorodibenzofuran (PeCDF) are varied in Yusho patients. The objective was to evaluate a relationship between half-lives of PeCDF levels and types of SNP rs10249788 of aryl hydrocarbon receptor (AHR) gene in 93 Yusho patients. Based on physical symptoms, age, sex, body mass index and other factors, we set up suitable calculation formulas to fit the actual PeCDF levels thorough rates of change in PeCDF. We found that patients with C/T SNP had longer half lives than patients with C/C and T/T SNPs. Patients with T/T SNP are known to express higher amount of AHR mRNAs. However, detailed analysis could not be carried out in T/T group due to a limited number of patients (n = 11). Further research is warranted to determine the cause of the longer half-lives in C/T patients.

Selenium-binding protein 1: its physiological function, dependence on aryl hydrocarbon receptors, and role in wasting syndrome by 2,3,7,8-tetrachlorodibenzo-p-dioxin.

BACKGROUND: Selenium-binding protein 1 (Selenbp1) is suggested to play a role in tumor suppression, and may be involved in the toxicity produced by dioxin, an activator of aryl hydrocarbon receptors (AhR). However, the mechanism or likelihood is largely unknown because of the limited information available about the physiological role of Selenbp1. METHODS: To address this issue, we generated Selenbp1-null [Selenbp1 (-/-)] mice, and examined the toxic effect of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in this mouse model. RESULTS: Selenbp1 (-/-) mice exhibited only a few differences from wild-type mice in their apparent phenotypes. However, a DNA microarray experiment showed that many genes including Notch1 and Cdk1, which are known to be enhanced in ovarian carcinoma, are also increased in the ovaries of Selenbp1 (-/-) mice. Based on the different responses to TCDD between C57BL/6J and DBA/2J strains of mice, the expression of Selenbp1 is suggested to be under the control of AhR. However, wasting syndrome by TCDD occurred equally in Selenbp1 (-/-) and (+/+) mice. CONCLUSIONS: The above pieces of evidence suggest that 1) Selenbp1 suppresses the expression of tumor-promoting genes although a reduction in Selenbp1 alone is not very serious as far as the animals are concerned; and 2) Selenbp1 induction by TCDD is neither a pre-requisite for toxicity nor a protective response for combating TCDD toxicity. GENERAL SIGNIFICANCE: Selenbp1 (-/-) mice exhibit little difference in their apparent phenotype and responsiveness to dioxin compared with the wild-type. This may be due to the compensation of Selenbp1 function by a closely-related protein, Selenbp2.

2,3,4,7,8-Pentachlorodibenzofuran is far less potent than 2,3,7,8-tetrachlorodibenzo-p-dioxin in disrupting the pituitary-gonad axis of the rat fetus.

The effect of 2,3,4,7,8-pentachlorodibenzofuran (PnCDF) on the fetal pituitary-gonad axis was compared with that produced by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in Wistar rats. Maternal treatment at gestational day (GD) 15 with PnCDF and TCDD reduced the fetal expression at GD20 of pituitary luteinizing hormone (LH) and the testicular proteins necessary for steroidogenesis. The relative potencies of PnCDF ranged from 1/42nd to 1/63rd of the TCDD effect. While PnCDF, at a dose sufficient to cause a reduction in fetal LH, provoked defects in sexual behavior at adulthood, a dose less than the ED50 failed to produce any abnormality. There was a loss of fetal body weight following in utero exposure to PnCDF, and the effect of PnCDF was also much less than that of TCDD. The disturbance in fetal growth was suggested to be due to a reduction in the level of fetal growth hormone (GH) by dioxins. The disorder caused by PnCDF/TCDD in the fetal pituitary-gonad axis occurred at doses less than those needed to cause wasting syndrome in pubertal rats. The harmful effect of PnCDF relative to TCDD was more pronounced in fetal rats than in pubertal rats. These lines of evidence suggest that: 1) PnCDF as well as TCDD imprints defects in sexual behavior by disrupting the fetal pituitary-gonad axis; 2) these dioxins hinder fetal growth by reducing the expression of fetal GH; and 3) the fetal effects of PnCDF/TCDD are more sensitive than sub-acute toxicity during puberty, and the relative effect of PnCDF varies markedly depending on the indices used.

Characterization of placental transfer of polychlorinated dibenzo-p-dioxins, dibenzofurans and polychlorinated biphenyls in normal pregnancy.

AIM: Prenatal exposure to dioxins may result in many adverse health effects. However, the mechanisms by which dioxins are transferred from mother to fetus through the placenta are not well understood. The aim of this study was to investigate the differences in dioxin concentrations between maternal blood, the placenta, and cord blood in normal pregnant women, and to identify which individual congeners of these compounds are transferred from mother to fetus through the placenta. MATERIAL AND METHODS: Samples were collected from 19 pregnant Japanese women. Specific congeners of seven polychlorinated dibenzo-p-dioxins (PCDDs), 10 polychlorinated dibenzofurans (PCDFs), and four non-ortho polychlorinated biphenyls (PCBs) were analyzed. RESULTS: The TEQ concentrations of PCDDs, PCDFs, and non-ortho PCBs were 8.03, 3.39, and 3.95 pg TEQ/g lipid, respectively, in the maternal blood; 8.78, 3.61, and 0.87 pg TEQ/g lipid in the placenta; and 4.33, 1.25, 1.08 pg TEQ/g lipid in the cord blood. Among specific congeners, 1,2,3,7,8-PentaCDD and 2,3,4,7,8-PentaCDF exhibited a placenta to maternal blood ratio greater than 1.0, while OctaCDD exhibited the greatest cord blood to placenta ratio. The cord blood to maternal blood ratio of total PCDDs was significantly higher than that of total PCDFs and total non-ortho PCBs. CONCLUSION: The dioxin concentration in cord blood was approximately half of the amount in maternal blood, despite congeners showing a high toxic equivalency factor accumulating in the placenta. PCDDs were transferred more readily than PCDFs and non-ortho PCBs from maternal blood to the fetus through the placenta.

Aortic regurgitation associated with critical aortic stenosis in a fetus.

Aortic regurgitation in association with aortic stenosis is rare in the fetus. Findings have shown that severe aortic regurgitation is worsened by the increase in systemic vascular resistance after birth, resulting in low cardiac output, hypoxemia, and neonatal death. This report describes a unique case of aortic regurgitation with aortic stenosis, severe mitral regurgitation, retrograde flow in the aortic arch, and an enormous left atrium with a restrictive foramen ovale in a fetus. In this case, aortic regurgitation was diminished immediately after birth, indicating that spontaneous improvement in aortic regurgitation after birth should be taken into account when the final prognosis is predicted.

Prediction and evaluation of fetal toxicity induced by NSAIDs using transplacental kinetic parameters obtained from human placental perfusion studies.

AIM: The use of nonsteroidal anti-inflammatory drugs (NSAIDs) in full-term pregnant women leads to fetal or neonatal toxicity, such as constriction of the ductus arteriosus (DA) and persistent pulmonary hypertension in the newborn. The aim of this study was to predict quantitatively the fetal toxicity of three NSAIDs (antipyrine, salicylic acid and diclofenac) using the transplacental pharmacokinetic parameters obtained from our previous placental perfusion studies. METHODS: Human fetal plasma concentration profile after oral administration of each NSAID to the mother was estimated using the transplacental pharmacokinetic parameters and pharmacokinetic parameters in adult women. The fetal plasma concentration-response relationship for the three NSAIDs was estimated by pharmacokinetic/pharmacodynamic analysis of the results of previous studies investigating the effects of NSAIDs on the ratio of inner diameter of the DA to that of the pulmonary artery (DA/PA) in rats and the plasma concentration profiles of NSAIDs in pregnant rats. RESULTS: The risk of constriction of the DA was well predicted by the model. Mean DA/PA ratio after oral administration of diclofenac to the mother was estimated to be 39.0%, whereas both of the corresponding values after oral administration of antipyrine and salicylic acid were estimated to be 5.9%. These results suggest that the fetal risk of diclofenac is higher than those of salicylic acid and antipyrine. CONCLUSIONS: This study presents a novel approach to predict quantitatively the fetal risk of NSAIDs administered to the mother. Human placental perfusion study and pharmacokinetic/pharmacodynamic analysis may provide basic data for predicting human fetal toxicity of drugs.

Critical Ebstein anomaly in a fetus successfully managed by elective preterm delivery and surgical intervention without delay after birth.

This report describes a case of Ebstein anomaly in a fetus with cardiomegaly, severe tricuspid regurgitation, pulmonary regurgitation, and retrograde ductal flow that showed a marked increase in the size of the right atrium with advancing gestational age. Elective preterm delivery was performed at 35 weeks gestation. The prostaglandin E1 infusion resulted in more pronounced systemic hypotension and acidosis secondary to circular shunt across the patent ductus arteriosus as well as pulmonary regurgitation and tricuspid regurgitation. Emergency surgical intervention consisting of main pulmonary artery ligation, ductus arteriosus ligation, central shunt creation, and plication of the right atrium without cardiopulmonary bypass was performed 4 h after birth. At the age of 16 days, the Starnes procedure was performed. The infant's postoperative course was uneventful. A fetus that has Ebstein anomaly associated with pulmonary regurgitation is at risk for circular shunt across the patent ductus arteriosus after delivery. Planned delivery and surgical intervention without delay after birth are useful for the treatment of such cases.

Grayscale and Doppler sonographic evaluation of response to in utero treatment of hydrops fetalis caused by extralobar pulmonary sequestration.

Pulmonary sequestration is defined as nonfunctional lung tissue that lacks communication with the bronchial tree and that is supplied by an anomalous systemic vessel. In comparatively rare cases, pulmonary sequestration may lead to hydrothorax or hydrops fetalis, which is nearly universally fatal. In this report, we describe a case of pulmonary sequestration with hydrops fetalis, which was successfully treated by thoracoamniotic shunting. A sonographic Doppler study in this case suggested that the underlying mechanism of the hydropic change in a fetus with extralobar pulmonary sequestration may have differed from that in fetuses with primary hydrothorax not associated with a structural anomaly.

Prognosis and long-term neurodevelopmental outcome in conservatively treated twin-to-twin transfusion syndrome.

BACKGROUND: Amnioreduction remains a treatment option for pregnancies with twin-to-twin transfusion syndrome (TTTS) not meeting criteria for laser surgery or those in which it is not feasible. Amnioreduction is a relatively simple treatment which does not require sophisticated technical equipment. Previous reports of conservative management have indicated that major neurodevelopmental impairment occurs in 14.3-26% of survivors. The purpose of this study was to investigate long-term neurodevelopmental outcome in conservatively treated TTTS. METHODS: During the nine-year study period from January 1996 to December 2004, all pregnancies with TTTS who were admitted to our center were investigated. TTTS was diagnosed by using standard prenatal ultrasound criteria, and staged according to the criteria of Quintero et al. We reviewed gestational age at diagnosis, gestational age at delivery, the stage of TTTS at diagnosis, and diagnosis to delivery interval. Neonatal cranial ultrasound findings were reviewed and the neurodevelopmental outcomes were evaluated. RESULTS: Twenty-one pregnancies with TTTS were included. Thirteen pregnancies (62%) were treated with serial amnioreduction. The mean gestational age at delivery was 28 weeks (22-34 weeks). The perinatal mortality rate was 42.9%. Twenty survivors were followed up until at least 3 years of age. The mean age at follow-up was 6.3 years (3-12 years). Six children (30%) had neurodevelopmental impairment. Four children (20%) had major neurodevelopmental impairment and two children (10%) had minor neurodevelopmental impairment. Children with neurodevelopmental impairment were delivered before 29 weeks of gestation. CONCLUSIONS: Our study showed a high rate of perinatal mortality and a high rate of major neurodevelopmental impairment in conservatively treated TTTS. The long-term outcomes for the survivors with TTTS were good when survivors were delivered after 29 weeks of gestation.

Abnormal fetal movements, micrognathia and pulmonary hypoplasia: a case report. Abnormal fetal movements.

BACKGROUND: Micrognathia is a facial malformation characterized by mandibular hypoplasia and a small, receding chin that fails to maintain the tongue in a forward position. We previously reported a system of prenatal screening that we developed to identify fetuses with compromised central nervous system function by observing fetal behavior. In this paper we report the case of a preterm infant with micrognathia and pulmonary hypoplasia who presented abnormal fetal movements. CASE PRESENTATION: A 27-year-old Japanese primigravida at 33 weeks of gestation was referred to our hospital. Ultrasonographic examination revealed clinical polyhydramnios. Micrognathia was evident on midsagittal and 3 D scan. The lung area was less than the mean -2.0 standard deviations for the gestational age. The infant had mandibular hypoplasia and glossoptosis. After emergency cesarean delivery for non-reasuring fetal status, required immediate tracheostomy and cardiopulmonary resuscitation with mechanical ventilatory support. However, the infant's cardiopulmonary condition did not improve and she died 21 hours after birth. CONCLUSIONS: The findings of our ultrasound exam are suggestive of brain dysfunction. The observation of fetal behavior appears to be effective for the prediction of prognosis of cases with micrognathia.

Cardiac hypertrophy of one fetus and selective growth restriction of the other fetus in a monochorionic twin pregnancy.

Cardiac hypertrophy in the recipient fetus of twin-twin transfusion syndrome (TTTS) has been reported previously. We encountered an unusual set of monochorionic twins in which one twin had cardiac hypertrophy without TTTS while the other fetus had selective growth restriction. In this case, the diagnosis of selective growth restriction was made at 17 weeks of gestation, and right ventricular hypertrophy was identified in the co-twin at 21 weeks; however, no signs of TTTS were observed. At 29 weeks we concluded that the fetal circulation had deteriorated based on echocardiographic findings that included hydrops fetalis and an elevated preload index. Emergency cesarean section was performed. Our experience suggests that hypertrophic cardiomyopathy-like change in a monochorionic twin pregnancy may arise in settings outside of TTTS, including growth restriction of a co-twin. We believe our case will assist the discussion surrounding the etiology of cardiac hypertrophy in monochorionic twins.

Transplacental pharmacokinetics of diclofenac in perfused human placenta.

The aims of this study were to evaluate the transplacental transfer properties of diclofenac and to determine the effect of L-lactic acid on the transplacental transfer of diclofenac. The maternal and fetal vessels of human placenta were perfused in a single-pass mode with a solution containing diclofenac and antipyrine. The transplacental pharmacokinetic model was fitted to the time profiles of the drug concentrations in the effluent and placenta to obtain transplacental pharmacokinetic parameters. In addition, chloride ion in the perfusate was partially replaced with L-lactic acid to see the change in the transplacental transfer properties of diclofenac. The TPT(ss) value (ratio of the rate of amount transferred across the placenta to that infused in the steady state) of diclofenac was 2.22%, which was approximately one-third that of antipyrine and was significantly reduced in the presence of L-lactic acid. The transplacental pharmacokinetic model could adequately explain the transplacental transfer of diclofenac with influx clearances from maternal and fetal perfusates to placental tissue of 0.276 and 0.0345 ml/min/g cotyledon and efflux rate constants from placental tissue to maternal and fetal perfusates of 0.406 and 0.0337 min(-1), respectively. By taking into account protein binding, the placental tissue/plasma concentration ratio in humans for diclofenac was estimated to be 0.108 ml/g of cotyledon and was smaller than that of antipyrine. In conclusion, human placental perfusion and transplacental pharmacokinetic modeling allowed us to determine the transplacental transfer properties of diclofenac quantitatively. Diclofenac may share transplacental transfer system(s) with L-lactic acid.

Can we diagnose invasive cervical cancer during pregnancy as precise as in nonpregnant women?: maternal and perinatal outcome in pregnancies complicated with cervical cancers.

Cervical cancer is the most common gynecologic malignancy associated with pregnancy. However, there are no consensus guidelines that define the indications for or the optimal length of expectant management. The subjects were women who had a preexisting invasive cervical cancer or whose cancers were diagnosed during pregnancy or within 12 months after delivery. Thirty-nine consecutive women with cervical cancer, whose ages ranged from 20 to 40 years, were chosen as controls. We performed a retrospective chart review on the maternal profile and perinatal outcome and compared the clinical features between pregnancy- and non-pregnancy-associated cervical cancer in patients. The percentage of asymptomatic cases in which cancer was detected in a routine Papanicolaou test was significantly higher in the pregnant patients. The percentage of induced preterm labor or therapeutic abortions was 50%. Expectant management (mean length, 19.8 weeks) was chosen by 5 patients, and there were no cases of recurrence or death from disease. Seven subjects, including 5 patients whose diagnoses were changed from cervical intraepithelial neoplasm or condyloma to cancer, were managed as "unexpected expectant" because these subjects were not diagnosed as having stage IA/IB cancer during pregnancy. All of these subjects underwent vaginal delivery and included 2 patients with death from disease and lymph node recurrence. The percentage in which disease severity was underestimated was higher in pregnant patients. The option of therapeutic delay should be carefully discussed. Patient counseling should address the issue that risk may not be precisely estimated because of the possibility that disease severity may be underestimated during pregnancy.

Preload index of the inferior vena cava as a possible predictive marker of hydropic changes in fetuses with Ebstein anomaly.

OBJECTIVE: We aimed to investigate whether the preload index of the inferior vena cava (PLI-IVC) is of diagnostic value in predicting hydropic changes in fetuses with Ebstein anomaly. METHODS: Five cases of prenatally diagnosed Ebstein anomaly, which were managed at our institution between 1999 and 2008, were retrospectively reviewed. The PLI-IVC was calculated as the ratio between the reversed flow velocity from the right atrium and the forward velocity of the IVC. RESULTS: The PLI-IVC was high in all the cases. In 2 cases, PLI-IVC values tended to increase gradually before hydropic changes were recognized. In the cases without hydrops, PLI-IVC values exhibited a nonlinear trend throughout gestation and did not show any apparent increase. CONCLUSIONS: The upward trend of the PLI-IVC rather than the maintenance of a high value can be considered a sign of cardiac failure. The blood flow pattern in the IVC should be carefully monitored in fetuses with Ebstein anomaly for the early identification of fetal impairment.

Outcome and treatment in an antenatally diagnosed congenital cystic adenomatoid malformation of the lung.

BACKGROUND: The natural history of patients with antenatally diagnosed congenital cystic adenomatoid malformation of the lung (CCAM) is still fully unknown. In symptomatic patients with respiratory distress, an operation is performed during the neonatal period. However, in asymptomatic patients, the optimal timing of the operation remains controversial. During the period from 1977 to 2007, we experienced 14 CCAM patients diagnosed antenatally. Therefore, we investigated the outcome of antenatally diagnosed CCAM patients to clarify the optimal treatment for such patients. METHODS: Fourteen patients were reviewed regarding the antenatal ultrasonography findings and postnatal clinical course. They were then classified into three groups according to the clinical manifestations. Group A was associated with hydrops fetalis (n = 2), group B had respiratory symptoms just after birth (n = 6), and group C was asymptomatic at birth (n = 6). The postnatal clinical courses in three groups were reviewed. RESULTS: In group A, all two patients with hydrops fetalis died just after birth. In group B, six patients had a severe respiratory distress and underwent operation during the neonatal period. In group C, five out of six patients were asymptomatic and received elective operation during the early infant period. In the remaining one patient, the lesion spontaneously disappeared over time after birth. The mean age at the time of operation in group B and group C was 4.5 days and 4.5 months of age, respectively. In almost all patients in group C, we performed an operation within the first 6 months. During this observation period, we did not experience any complications associated with CCAM. CONCLUSION: In patients with hydrops fetalis, fetal intervention is thought to be needed. In patients with asymptomatic CCAM, an elective operation during the early infant period is recommended to prevent the risk of complications associated with CCAM before 6 months of age. In addition, we recommend the performance of a partial lung resection using an axillary skin crease incision in order to obtain a good postoperative quality of life.