Blocking expression of AHR2 and ARNT1 in zebrafish larvae protects against cardiac toxicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin

The zebrafish (Danio rerio) has become an attractive vertebrate model for studying developmental processes, and is emerging as a model system for studying the mechanisms by which xenobiotic compounds perturb normal development. Embryos treated with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) shortly after fertilization exhibit a range of adverse effects on the heart: an early reduction in cardiac myocyte number, followed by a change in heart looping and morphology, with an apparent compaction of the ventricle and overall decrease in heart size. These changes are accompanied by impaired cardiac function including a decrease in cardiac output and eventually irreversible ventricular standstill. The mechanisms involved in mediating effects of TCDD on the heart remain unknown. However, it is widely accepted that aryl hydrocarbon receptor (AHR) activation mediates endpoints of TCDD toxicity in vertebrates. In zebrafish, there are multiple forms of AHR and AHR nuclear translocator protein (ARNT) raising the question about whether different endpoints of TCDD toxicity are mediated by different components of the AHR/ARNT pathway. To address this question we used morpholino oligonucleotide technology to specifically block the expression of zfAHR2, zfARNT1, zfARNT2, and zfCYP1A, and assessed the previously described effects of TCDD on heart morphology, size, and function in the developing morphants. We report that blocking zfAHR2 and zfARNT1 expression provided protection against the TCDD-mediated alteration in heart morphology, reduced cardiac myocyte number, decreased cardiac output and ventricular standstill in zebrafish larvae, while the zfarnt2 and zfcyp1a morpholinos did not block the TCDD-induced cardiac toxicity.

Folate intake and the primary prevention of non-neural birth defects

OBJECTIVES

To investigate whether maternal periconceptional folate intake is associated with a reduction in selected non-neural birth defects in Western Australia (WA).

METHODS

Case-control study of folate intake in women whose infants had orofacial clefts (62); congenital heart defects (151); urinary tract defects (117); limb reduction defects (26); or other major birth defects (119); and 578 control women.

RESULTS

Neither folic acid supplements nor dietary folate intake in women not using supplements was significantly associated with a reduction in risk in any of the case groups. In contrast to neural tube defects, WA population data for orofacial clefts, heart defects, limb reduction defects and urinary tract defects showed no fall in prevalence since the introduction of folate promotion and voluntary food fortification.

CONCLUSIONS

This study provides no evidence of folate being an important factor in the prevention of birth defects other than neural tube defects.

Daily physical activity and perception of condition severity among male and female adolescents with congenital heart malformation

The purpose of this study was to examine among young patients with congenital heart malformation (CHM) the concordance between a cardiologist's definition of the severity of malformation and recommendations regarding physical activity and the patients' perceptions of their condition. Subjects included male (n = 55) and female (n = 45) adolescents aged between 12 and 18 years who have trivial (38%), mild (21%), or moderate (41%) CHM. Thirty-one percent of the patients rated their CHM as less severe whereas 15% rated their CHM as more severe than the cardiologist's definition. Although most patients engaged in physical activity appropriate for their condition, a noteworthy percentage engaged in activities more intense than those recommended by the patient's personal cardiologist.

Maternal MTHFR 677C>T is a risk factor for congenital heart defects: effect modification by periconceptional folate supplementation

AIMS

Periconceptional folate supplementation prevents neural tube defects and possibly congenital heart defects (CHD) as well. The search for candidate genes involved in the folate metabolism includes the methylenetetrahydrofolate reductase (MTHFR) 677C > T polymorphism. We studied the association between MTHFR 677C > T variants and CHD risk. The interaction with periconceptional folate supplementation was also investigated.

METHODS AND RESULTS

A case-control study and a family-based transmission disequilibrium test (TDT) were conducted to explore this association. In 133 triads, the TDT revealed no association of the fetal 677T allele with the development of a heart defect. In 158 mothers with a CHD-affected child, the maternal MTHFR 677CT and TT genotypes in combination with no use of periconceptional folate supplements were associated with, respectively, a three-fold (OR 3.3 95% CI 1.46-7.32) and six-fold (OR 6.3 95% CI 2.32-17.27) increased risk for conotruncal heart defects in offspring. In a case-only study, the interaction between periconceptional folate supplementation and maternal MTHFR genotype was significant (P = 0.012).

CONCLUSION

The maternal MTHFR 677C > T variants are a risk factor for CHD in offspring, confined to conotruncal heart defects. A gene-environment interaction between maternal MTFHR 677CT and TT genotypes with periconceptional folate supplementation was observed. These findings provide a mechanism of the protective role of folate and support the thesis that periconceptional folate supplementation might prevent CHD.

Partial Correction of Abnormal Cardiac Development in Caspase-8-deficient Mice by Cardiomyocyte Expression of p35

Baculovirus p 35 protein protects cells from apoptotic cell death by inhibiting caspase activation. We have established transgenic mouse lines specifically expressing p 35 in cardiomyocytes, and primary cardiomyocytes isolated from these mice exhibit resistance to staurosporine-induced apoptosis. In a previous study, we observed defects in heart formation associated with abdominal hemorrhage and cardiomyocyte cell death in caspase-8-deficient animals. In order to better understand the etiology of the cardiac defects and embryonic lethality in caspase-8-deficient mice, we crossed these mice with the p 35 transgenic animals. Although the newly generated mice still died in utero and exhibited some cardiac defects, cardiomyocyte apoptosis was suppressed and ventricular trabeculation was restored. Thus, cardiomyocyte expression of p 35 prevented cell death induced by staurosporine or caspase-8 deficiency. Additionally, our data suggest that caspase-8 plays multiple roles in cardiac development.

Congenital heart defects and maternal biomarkers of oxidative stress

BACKGROUND

Women who have had pregnancies that were affected by nonsyndromic congenital heart defects have alterations in the homocysteine-methionine pathway that may indicate increased exposure to oxidative stress or reduced antioxidant defense or both.

OBJECTIVE

Our goal was to establish a maternal metabolic risk profile for nonsyndromic congenital heart defects that would enhance current preventive strategies.

DESIGN

Using a case-control design, we measured biomarkers of the transsulfuration pathway in a population-based sample of women whose pregnancies were affected by congenital heart defects (331 cases) and in a control group of women (125 controls). Plasma concentrations of reduced and oxidized glutathione, vitamin B-6, homocysteine, cysteine, cysteinylglycine (CysGly), and glutamylcysteine (GluCys) were compared between cases and controls after adjustment for lifestyle and sociodemographic variables.

RESULTS

After covariate adjustment, cases had significantly lower mean plasma concentrations of reduced glutathione (P < 0.0001), GluCys (P < 0.0001), and vitamin B-6 (P = 0.0023) and significantly higher mean concentrations of homocysteine (P < 0.0001) and oxidized glutathione (P < 0.0001) than did controls.

CONCLUSIONS

Biomarkers of oxidative stress involved in the transsulfuration pathway were significantly higher in women with pregnancies affected by congenital heart defects than in women without such a history. Further analysis of relevant biomarkers of oxidative stress and genetic and environmental factors is required to define the basis for the observed alterations. Identifying the nature and extent of alterations in biomarkers of oxidative stress may suggest primary intervention strategies and provide clues to a greater understanding of the pathogenesis of congenital heart defects.

Folic acid supplementation and the occurrence of congenital heart defects, orofacial clefts, multiple births, and miscarriage

Key research findings relative to the question of whether maternal use of folic acid before and during pregnancy reduces the chance that offspring will be born with a congenital heart defect or an orofacial cleft are reviewed in this paper. Observational studies in general support an association between maternal use of multivitamins containing folic acid and a reduction in the occurrence of congenital heart defects and orofacial clefts. Results from one randomized controlled trial (RCT) provide the strongest evidence that multivitamins prevent congenital heart defects, but this RCT did not provide evidence that multivitamins prevent orofacial clefts. In addition, most observational and interventional studies are not designed to detect an independent effect from folic acid. Early studies suggested that periconceptional multivitamin use was associated with an increased occurrence of both miscarriages and multiple births, which has resulted in a great deal of controversy about the safety of folic acid use during pregnancy. We also review reports that were designed to answer these questions with more definitive data. When more substantial evidence about the effect of periconceptional folic acid on the occurrence of congenital heart defects and orofacial clefts is reported, we will have additional support for promoting folic acid intervention programs. All women capable of becoming pregnant should continue to consume 400 mug/d of folic acid in addition to a healthy diet as advised.

Transplanted human embryonic stem cells as biological ‘catalysts’ for tissue repair and regeneration

Human embryonic stem cells have tremendous potential in the newly emerging field of regenerative medicine. Recently, it was demonstrated that the rescue of lethal cardiac defects in Id knockout mutant mouse embryos was not due to the transplanted cells giving rise to functional new tissues within the defective embryonic heart. Instead, there is indirect evidence that the observed therapeutic effect was due to various secreted factors emanating from the transplanted cells. This therefore, introduces the exciting prospect of utilizing human embryonic stem cells as biological 'catalysts' to promote tissue repair and regeneration in transplantation therapy. However, the immunological barrier against allogenic transplantation, as well as the teratogenic potential of human embryonic stem cells poses major technical challenges. A possible strategy to overcome the immunological barrier may be to impose a temporary regimen of immunosuppressive drugs followed by their gradual withdrawal, once adequate tissue regeneration has been achieved. Other more novel alternatives include the use of microencapsulation to block interaction with the transplant recipient's immune system, and co-transplantation with bone marrow-derived mesenchymal stem cells, which have been demonstrated to possess immuno-suppressive properties. The teratogenic potential of human embryonic stem cells could possibly be alleviated by directing the differentiation of these cells to specific lineages prior to transplantation, or through mitotic inactivation (gamma irradiation or mitomycin C exposure). Co-transplantation with autologous adult stem cells may represent a novel strategy to further enhance the 'catalytic' effects of human embryonic stem cells. The various factors secreted by human embryonic stem cells could then have a concentrated localized effect on relatively large numbers of co-transplanted autologous adult stem cells, which may in turn lead to enhanced repair and regeneration of the damaged tissue or organ. Moreover, there is also a possibility that synergistic interactions between the co-transplanted human embryonic stem cells and autologous adult stem cells, may somehow produce signals for the recruitment and migration of additional endogenous adult stem cells within the recipient (i.e. peripheral blood circulation, bone marrow), which could further enhance organ/tissue regeneration. Hence, the potential use of human embryonic stem cells as biological 'catalysts' to stimulate tissue repair and regeneration, appears to hold tremendous promise in the field of regenerative medicine. This new therapeutic strategy needs to thoroughly investigated, in view of its potentially important clinical applications.

Congenital heart defects and abnormal maternal biomarkers of methionine and homocysteine metabolism

BACKGROUND

It is well established that folic acid prevents neural tube defects. Although the mechanisms remain unclear, multivitamins containing folic acid may also protect against other birth defects, including congenital heart defects.

OBJECTIVE

Our goal was to establish a maternal metabolic risk profile for nonsyndromic congenital heart defects that would enhance current preventive strategies.

DESIGN

Using a case-control design, we measured biomarkers of the folate-dependent methionine and homocysteine pathway among a population-based sample of women whose pregnancies were affected by congenital heart defects (224 case subjects) or unaffected by any birth defect (90 control subjects). Plasma concentrations of folic acid, homocysteine, methionine, S-adenosylmethionine (SAM), S-adenosylhomocysteine (SAH), vitamin B-12, and adenosine were compared, with control for lifestyle and sociodemographic variables.

RESULTS

After covariate adjustment, case subjects had higher mean concentrations of homocysteine (P < 0.001) and SAH (P < 0.001) and lower mean concentrations of methionine (P = 0.019) and SAM (P = 0.014) than did control subjects. Vitamin B-12, folic acid, and adenosine concentrations did not differ significantly between case and control subjects. Homocysteine, SAH, and methionine were identified as the most important biomarkers predictive of case or control status.

CONCLUSIONS

The basis for the observed abnormal metabolic profile among women whose pregnancies were affected by congenital heart defects cannot be defined without further analysis of relevant genetic and environmental factors. Nevertheless, a metabolic profile that is predictive of congenital heart defect risk would help to refine current nutritional intervention strategies to reduce risk and may provide mechanistic clues for further experimental studies.

[Effects of taurine on the heart defects in chick embryos which induced by homocysteine]

OBJECTIVE

To explore the effects of taurine on the heart defects in chick embryos induced by homocysteine (HCY).

METHODS

Through the teratogenicity test of Chick Embryos, the taurine and HCY were given to yolk sac of 3 day's chick embryos. Histopathological examination after another 2 days culture.

RESULTS

The occurrence of heart defects on HCY group were significantly increased. The growth of vitelline vessels was decreased. The prevention of tautine on the heart defects in chick embryos induced by HCY was very significantly effective.

CONCLUSION

Taurine can prevent the developmental disturbance of hearts induced by HCY in this experiment.

[Prenatal diagnosis of arrhythmias and conduction disturbances]

OBJECTIVES AND DESIGN

Cardiac arrhythmias are one of the most frequent indications for the fetal echocardiographic assessment. The objective of this work is to present our own results of diagnosing and treating the fetuses with arrhythmias.

MATERIALS AND METHODS

The 1485 prenatal echocardiographic examinations were performed in 1302 fetuses. The 109 of fetuses suffered from arrhythmias.

RESULTS

68 fetuses (62.8%) in the analysed group presented with arrhythmias in the form of extra-systoles, 19 fetuses (17.4%) with tachycardia and 22 (20.2%) with a complete atrioventricular block.

CONCLUSIONS

We concluded, that arrhythmias can be diagnosed precisely in the early prenatal period, which enables the introduction of the adequate pharmacological treatment and the coexistence of the fetal complete a-v block and structural heart defect in a fetus is associated with poor prognosis.

Role of nutrition in pregnancy with phenylketonuria and birth defects

OBJECTIVE

The maternal phenylketonuria (PKU) syndrome is caused by high blood phenylalanine (Phe) levels during pregnancy, leading to a host of birth defects, especially microcephaly and congenital heart disease (CHD). For finding whether the maternal PKU syndrome could be prevented, an international collaborative study was organized to evaluate treatment with a Phe-restricted diet. Blood Phe levels, maternal weight gain, and nutrient intakes during pregnancy were evaluated as to their effect on the rate of microcephaly and CHD in the offspring.

METHODS

The study was a prospective, longitudinal effort aimed at lowering blood Phe during pregnancy. Women were enrolled at time of referral for pregnancy. Nutrient intake analysis, which serves as the basis for this report, was available from 251 pregnancies. Subjects were stratified by blood Phe control of < or =600 micromol/L by 8 weeks gestation or >600 micromol/L by 8 weeks gestation. Outcome of these pregnancies was correlated to blood Phe levels, weight gain, and nutrient intake.

RESULTS

The study goal was to attain blood Phe levels of 120 to 360 micromol/L 3 months preconception; however, this goal was achieved by only a limited number of patients. Therefore, the data presented were based on blood Phe control < or =600 micromol/L or >600 micromol/L by 8 weeks of gestation. Blood Phe control of < or =600 micromol/L by 8 weeks of gestation was attained by 86 (34.3%) of the 251 women in this study, whereas the other 165 women had blood Phe control >600 micromol/L by 8 weeks of gestation. Of the 251 offspring, 166 were born with normal head circumference and 85 were born with microcephaly (<2 standard deviations below normal). Women with blood Phe >600 micromol/L at 8 weeks of gestation included 78 (92%) of the 85 infants with microcephaly compared with 8% in the group of women who had blood Phe levels < or =600 micromol/L. Weight gain during pregnancy was related to the rate of microcephaly. The highest occurrence of microcephaly (58%) was found in the pregnant women who gained <70% of recommended weight gain. Stepwise logistic regression analysis was used to determine factors associated with microcephaly. Significant factors included higher blood Phe levels when off diet, higher average Phe exposure during the pregnancy, low prepregnancy weight, poor weight gain during the pregnancy, and lower intake of protein and higher iron intake during the pregnancy. Infants with CHD were found only in the group of women who had blood Phe levels >600 micromol/L by 8 weeks of gestation. There was a higher rate of CHD in the offspring who were born to women who consumed <50% of the recommended intake of protein in the first trimester. The main source of protein for women with PKU is the medical food; therefore, when protein intake was low, vitamin and mineral intakes were also inadequate.

CONCLUSIONS

The data indicate that blood Phe control and how soon it is attained during pregnancy with PKU is important. Normal pregnancy weight gain should be encouraged to reduce microcephaly. Adequate protein and vitamin intakes early in pregnancy may have a protective effect for the prevention of CHD, even if blood Phe is elevated. The rate of microcephaly and CHD may be reduced if nutrient intake is optimal while attempting to control blood Phe levels.

Do multivitamin or folic acid supplements reduce the risk for congenital heart defects? Evidence and gaps

Congenital heart defects are among the most common congenital anomalies and are the leading cause of infant death due to congenital anomalies. Except for a few known measures, effective primary prevention is not yet feasible for most heart anomalies. Recent reports have associated the use of multivitamin supplements around the time of conception and during early pregnancy with a reduced risk for heart defects in the offspring. We review and discuss the evidence and suggest a framework for further investigation in this area.

Prenatal vitamin E improves lung and heart hypoplasia in experimental diaphragmatic [correction of diaphragamatic] hernia

Nitrofen induces in rats diaphragmatic hernia (CDH) with heart and lung hypoplasia by a mechanism involving oxidation. The aim of this study was to examine if prenatal administration of the anti-oxidant agent vitamin E (VitE) prevents to some extent heart and lung hypoplasia. Pregnant rats received on E9.5 either 100 mg of nitrofen alone or followed by 150 IU of VitE on E16.5-E20.5. Control animals received either vehicle or VitE alone. The fetuses were recovered on E21. The hearts and lungs were weighed and DNA and proteins were measured. Sections of the heart and lung were immunohistochemically stained for ki-67, Tunel and TTF-1, and the proportions of proliferating, apoptotic and TTF-1-expressing cells were determined. Cultured human pneumocytes were exposed to the same agents and similarly processed. TTF-1 expression and the proportion of proliferating cells were quantitated. The ANOVA or Kruskall-Wallis tests were used for comparison with p<0.05 as threshold of significance. Nitrofen-exposed rats had decreased lung and heart weight/body weight ratios, lung and heart DNA and protein, lung TTF-1 expression and proportion of proliferating cells in lung and heart. Additional treatment with VitE ameliorated these decreases except for lung TTF-1 and heart weight. In cultured pneumocytes, TTF-1 expression was decreased by nitrofen and rescued by VitE. Cell proliferation followed the same pattern. Antioxidant VitE partially reverses the effects of nitrofen on the heart and lungs of exposed rats. The same effects are observed in cultured human pneumocytes. These results further substantiate the oxidative nature of the effects of nitrofen and suggest that anti-oxidant agents could have a potential clinical application.

The prevention of congenital anomalies with periconceptional folic acid supplementation

Large randomized trials have demonstrated the critical role of folic acid supplementation in the prevention of neural tube defects. Since 1992, a number of national and international professional societies have released guidelines recommending folic acid supplementation of at least 0.4 mg/day for all women of childbearing age or women planning pregnancies, and 4 mg/day for women with a previous infant with a neural tube defect. Furthermore, a reduction in the incidence of congenital cardiac and urologic anomalies has been demonstrated in some studies following periconceptional folic acid supplementation. There is growing evidence of a possible role of folic acid supplementation in the prevention of other congenital anomalies, including cardiac defects. Since 1998, mandatory fortification of certain foods with folate has been associated with at least a 54% reduction in the incidence of open neural tube defects, yet rates of periconceptional folic acid use remain suboptimal, especially in minority women. Innovative strategies in educating women, health-care providers, and pharmacists on the benefits of folic acid supplementation need to be explored. Mandatory folate fortification of foods needs to be defined and monitored.

Evidence-based prevention requires evidence-based performance. The case of screening for congenital heart disease in child health care

STUDY OBJECTIVE

To illustrate to what extent the cost-effectiveness of an evidence-based prevention programme may depend on evidence-based performance, by the example of screening for congenital heart disease in Dutch child health care.

METHODS

A patient follow-up study on 290 children with congenital heart disease, of which 83 with significant disorders, diagnosed over two years, and born in the south west of the Netherlands.

RESULTS

Adequate screening for congenital heart disease at Dutch child health centres, compared to inadequate screening, proves to be effective (OR: 0.18; 95% CI: 0.04-0.87). However only 15% of all patients with significant disorders in this study was adequately screened. Total health care costs involved over two years amount to over $3 million. Of these costs, 13% are to be attributed to screening tests; 8% to referrals resulting from screening. The costs for screening and referrals, as they were actually performed, are estimated at about $72.000 per patient benefiting from it. Were all children to be screened adequately this sum would be reduced to about $15.000.

CONCLUSION

Not only should prevention programmes be evidence-based, but also outcome and quality, monitored by periodically establishing whether they are optimally performed.

Nutrient intake and congenital heart defects in maternal phenylketonuria

OBJECTIVE

The purpose of this study was to determine whether nutritional components other than high maternal blood phenylalanine levels (> or = 10 mg/dL) are associated with congenital heart defects in the offspring of women with hyperphenylalaninemia.

STUDY DESIGN

Of the 414 subjects who had live births, 249 women (60.1%) started diet treatment before 8 weeks of gestation and had nutritional assessments and infant outcome data. Maternal phenylalanine levels, protein intake, and the incidence of congenital heart defects were determined. Simple contingency table analysis was done by chi(2) and Fisher exact test.

RESULTS

A significantly increased incidence of congenital heart defects was observed in offspring of mothers with hyperphenylalaninemia who had an elevated blood phenylalanine level >10 mg/dL at 0 to 8 weeks of gestation and a protein intake of < or = 50% of the recommended dietary allowance (P <.0013).

CONCLUSION

An inadequate intake of protein during pregnancy in conjunction with elevated blood phenylalanine levels appear to have an additive effect in the incidence of congenital heart defects in the offspring of women with hyperphenylalaninemia.

The genetics of congenital heart disease: a point in the revolution

Extraordinary diagnostic precision and definitive therapies characterize the current management of congenital heart disease, but the state of the art is not perfect; and in spite of tremendous progress in diagnosis and treatment, our understanding of cause is rudimentary. During the past decade, advances in molecular genetics have defined disease gene loci and lead to identification of genes whose mutations cause congenital heart disease. Identification of additional genes and mutations will lead to improved understanding of pathophysiology of cardiovascular disease in the young. Better understanding of pathophysiology and identification of individuals at risk will provide an opportunity to develop preventive strategies. Taken as a whole, the prospect of understanding the genetic basis of congenital heart disease and translating it into improved diagnostic and therapeutic strategies has never been better.

Perinatal management of fetal cardiac anomalies in a specialized obstetric-pediatrics center

Perinatal teams dealing with fetal heart disease frequently wonder which pregnancies might be terminated, and when delivery should take place in a specialized surrounding. We present a retrospective study of 229 fetuses, in which prenatal ultrasound showed a cardiac anomaly not compatible with a standard maternity ward delivery. One hundred nineteen pregnancies were terminated (group I) while 110 pregnancies led to the birth of a live baby (group II). Pathology in group I was discovered earlier than in group II (24 vs. 29.3 weeks' gestation; p <0.01), and associated malformations or chromosomal anomalies were much more frequent in group I (80/119 vs. 9/110; p <0.001). Among live born babies, three infants with transposition of the great arteries underwent Rashkind atrioseptostomy in the delivery room. With a minimum follow-up of 12 months, 69 children (63%) have undergone surgery. Among 92 survivors (1 child is lost to follow-up), 78 (71%) are asymptomatic and 14 symptomatic. Early prenatal diagnosis of fetal heart anomalies significantly facilitates prenatal work-up and perinatal care. We present the types of pathology having led to termination and define the situations in which children are at risk of perinatal hemodynamic compromise.

Frederine, a new and promising protector against doxorubicin-induced cardiotoxicity

The flavonoid 7-monohydroxyethylrutoside (monoHER) can protect against doxorubicin-induced cardiotoxicity. A drawback of monoHER therapy would be the relatively high dose needed to obtain complete protection (500 mg/kg in mice). Therefore, we synthesized a series of new compounds with improved antioxidant properties. After characterization of antioxidant activity, cardioprotection in vitro, and possible toxic properties in hepatocytes, we selected Frederine for additional investigations in vivo. In the present study, it was found that this compound did not induce weight loss or (gross) organ changes in mice in a treatment schedule of 170 mg/kg i.p., 5 times/week during 2 weeks. We recorded the electrocardiogram telemetrically in mice during and 2 weeks after the combined treatment with doxorubicin (4 mg/kg, i.v.) and 5 times Frederine (68 mg/kg, i.p.; equimolar to 100 mg/kg monoHER) for 6 weeks. Complete protection against doxorubicin-induced cardiotoxicity was found, indicating that Frederine is at least 5 times more potent than monoHER. Frederine did not have a negative influence on the antiproliferative effects of doxorubicin on A2780, OVCAR-3, and MCF-7 cells in vitro and on OVCAR-3 xenografts grown in nude mice when administered 5 min before doxorubicin (8 mg/kg i.v.) and 4 days thereafter with an interval of 24 h. It can be concluded that we succeeded in designing a better cardioprotector than monoHER. Therefore, Frederine merits further investigation as a possible protector against doxorubicin-induced cardiotoxicity in cancer patients.

[Fetal and genetic aspects of congenital heart disease]

Fetal cardiology includes the assessment of the fetal heart for congenital heart disease (CHD) and arrhythmias, the management of affected fetuses, including parental counselling for the therapeutic options, the planning of the delivery and the postnatal care. This requires a close collaboration between obstetricians, neonatologists and pediatric cardiologists. Because of restricted financial sources extensive fetal echocardiographic assessment is reserved for pregnancies with increased risk for CHD, which includes a family history of CHD, suspicion of a cardiac or extracardiac fetal abnormalities at obstetric routine ultrasonography, fetal arrhythmias and chromosomal anomalies. Since most CHD occur in pregnancies without increased risk an ultrasound screening of the fetal heart during routine pregnancy ultrasound is recommended. Most forms of CHD can potentially be detected in utero, especially the severe ones with considerable fetal and postnatal morbidity and mortality. The prenatal diagnosis of a major cardiac malformation requires further assessments for extracardiac and chromosomal disorders. The deliveries of patients with major cardiac anomalies in a tertiary obstetric center close to a pediatric cardiac facility allows optimal perinatal and postnatal management. This may be of crucial importance for cardiac malformations which are arterial duct dependent postnatally. Many CHD have genetic causes. Well established is the association of CHD and the trisomies 13, 18 and 21, as well as the monosomy XO (Turner syndrome). During the last years more and more molecular genetic causes for CHD could be demonstrated. The most significant one is the microdeletion 22q11 syndrome (CATCH 22 syndrome), which is associated with different conotruncal anomalies. Also for various other congenital cardiac malformations and syndromes a genetic cause could be demonstrated. The search for genetic cofactors is important as it affects parental counselling and patient care.