Victims of sexual offences: aspects impacting on participation, cooperation and engagement with the interview process.

The way in which police officers interview sexual offence victims is pivotal to how their cases proceed through the criminal justice system (CJS). However, such interviews have previously been found to be lacking in overall quality, with some interviewers finding them technically difficult and stressful to conduct. In addition, victims often feel disbelieved, unsafe and/or uncomfortable during their police interview. The present study provides insight into the personal experiences of five female adult rape/sexual assault victims regarding their police interviews and the aspects that encouraged them to cooperate and engage during the interview process. Following semi-structured interviews, interpretative phenomenological analysis (IPA) was used to identify three key themes: (i) heading into the unknown, (ii) difficulty of talking about the crime and (iii) helpful and unhelpful interviewer approaches. Implications for practice are discussed, together with the need to further our understanding of this specialist area of police work.

The effect of anti-emetic drugs on rat embryonic heart activity.

Nausea and vomiting of pregnancy (NVP) is the most common medical complaint during pregnancy affecting up to 70% of pregnant women worldwide. Some antiemetic medications (AEM) (droperidol, domperidone, granisetron, metoclopramide and trifluoperazine) used to treat NVP have the unwanted side effect of hERG blockade. The hERG potassium channel is essential for normal heart rhythm in both the adult human and the human and rat embryo. Animal studies show hERG blockade in the embryo causes bradycardia and arrhythmia leading to cardiovascular malformations and other birth defects. Whole rat embryo in vitro culture was used to determine the effect of the above listed AEM and meclizine on the heart rate of Gestational day 13 rat embryos. These embryos are similar in size and heart development to 5-6-week human embryo. The results showed that all of the AEMs caused a concentration-dependent bradycardia. Droperidol had the lowest margin of safety.

The effects of nifedipine and ivabradine on the functionality of the early rat embryonic heart. Are these drugs a risk in early human pregnancy?

BACKGROUND: When the human heart begins its earliest contractions from day 21, it lacks a functional autonomic nerve supply. Instead, contractions are generated by regular calcium transients later augmented by the funny current (If ) produced by sinoatrial-like cells. This study examined effects of blocking these currents in the early rat embryonic heart. METHODS: Rat embryos were incubated in vitro with either the calcium channel blocker nifedipine and/or the funny current (If ) blocker ivabradine for 1 hr to examine the effects of these drugs on the activity of the embryonic heart. RESULTS: On gestational day (GD) 10, nifedipine (0.45-1.8 µM) caused asystole at high concentrations (8/10 embryos at 1.8 µM and 3/10 embryos at 0.9 µM) and markedly increased embryonic heart rate (EHR) in all surviving embryos but likely reduced blood flow due to weak contractions. Ivabradine (1.5 µM) caused a 29% reduction in EHR in GD 10 embryos and a greater than 50% reduction in EHR for GD 11-14 embryos. Combined exposure to both nifedipine and ivabradine resulted in an additive effect. The increased EHR due to nifedipine was reduced by the ivabradine. CONCLUSION: The results suggest that exposure to nifedipine in human pregnancy 3-4 weeks postfertilization may cause a direct effect on the embryonic heart resulting in reduced blood flow leading to abnormal heart and/or blood vessel development and/or embryonic death. Accidental exposure to ivabradine in the organogenic period would be expected to cause embryonic bradycardia, hypoxia, malformations, and embryonic death. This drug is currently contraindicated in pregnancy.

Ondansetron and teratogenicity in rats: Evidence for a mechanism mediated via embryonic hERG blockade.

The potent hERG channel blocking drug ondansetron is used off-label for treatment of nausea and vomiting in early pregnancy. Some human epidemiological studies have associated ondansetron with fetal cardiovascular defects and orofacial clefts. This study investigated the effects of ondanestron on embryonic heart rhythm of gestational day (GD) 13 rat embryos in vitro and then integrated the results with published animal teratology, and animal and human pharmacokinetic studies to perform a risk evaluation. Ondansetron caused concentration dependent bradycardia and arrhythmia. Cardiovascular malformations in rats occurred at exposures slightly higher than those in early human pregnancy. Together the results suggest that ondansetron can have teratogenic potential in rats and humans mediated via hERG block and severe heart rhythm disturbances in the embryo. The risk may be increased in human pregnancy if additional risk factors are present such as hypokalemia.

Editor's Highlight: Ethylene Glycol Teratogenicity: A Role for Embryonic Acidosis?

Ethylene glycol (EG) is a developmental toxicant in pregnant rats and mice. A suggested mechanism for this toxicity is that the EG metabolite, glycolic acid (GA), causes acidosis which may affect the embryonic heart rate (HR). This inhibition would cause periods of embryonic bradycardia and arrhythmia resulting in increased embryonic death and malformation in surviving embryos. This hypothesis was investigated using gestational day (GD) 11 and 13 rat embryos in vitro. Increasing concentrations of GA or lactic acid in the incubation medium caused a decrease in external pH (pHe) and a concentration-dependent decrease in embryonic HR. Increased concentrations of GA or lactic acid with pHe corrected to normal levels did not affect HR. Severely decreased pHe, caused by reduced NaHCO3 in the incubation medium, had little effect on the HR of GD 13 embryos but substantially reduced the HR of GD 11 embryos. These results suggest that increased monocarboxylate concentration (glycolate or lactate) needs to be in combination with increased H+ concentration (low pHe) to influence the embryonic HR. These results implicate the monocarboxylate transporter reported to be present in the early postnatal rat heart, the chick embryonic heart throughout development, and the chorioallantoic placenta. The results showed some evidence that the adverse effect of GA and reduced pHe on the embryonic HR increased with duration of exposure and hence lends support to the suggested mechanism of embryotoxicity for EG.

Abnormal pregnancy outcome associated with high-dose maternal tranylcypromine therapy: Case report and literature review.

BACKGROUND: Tranylcypromine is a non-selective inhibitor of monamine oxidase which also inhibits the reuptake of norepinephrine. Spontaneous hypertensive reactions to the drug have been reported. In sheep tranylcypromine has been shown to cause a dose-dependent reduction in uterine blood flow. A similar effect in a pregnant woman might induce constriction of the uterine arteries and temporary fetal hypoxia. CASES: MotherSafe is a state-based Teratogen Information service and currently provides counselling to around 22,000 consumers and healthcare professionals annually regarding exposures during pregnancy and breastfeeding We report on the outcome of 2 pregnancies in a patient treated with high dose tranylcypromine as well as pimozide, diazepam and alprazolam. The first pregnancy resulted in fetal death and autopsy revealed facial dysmorphism with ocular hypertelorism, cardiac defect and placental infarcts. The second pregnancy continued to term but the baby had similar dysmorphic features as well as an atrio-ventricular septal defect and craniosynostosis. CONCLUSIONS: Due to their unpredictable interactions with many drugs and foods, MAO inhibitors such as tranylcypromine are not commonly used to treat depression and reports of use in pregnancy are rare. We report the outcome of 2 pregnancies with exposure to high doses of tranylcypromine resulting in children with a similar pattern of malformations. The aetiology is unknown but may relate to the vasoactive properties of the drug in above-therapeutic doses.

Control of the heart rate of rat embryos during the organogenic period.

The aim of this study was to gain insight into whether the first trimester embryo could control its own heart rate (HR) in response to hypoxia. The gestational day 13 rat embryo is a good model for the human embryo at 5-6 weeks gestation, as the heart is comparable in development and, like the human embryo, has no functional autonomic nerve supply at this stage. Utilizing a whole-embryo culture technique, we examined the effects of different pharmacological agents on HR under normoxic (95% oxygen) and hypoxic (20% oxygen) conditions. Oxygen concentrations ≤60% caused a concentration-dependent decrease in HR from normal levels of ~210 bpm. An adenosine agonist, AMP-activated protein kinase (AMPK) activator and KATP channel opener all caused bradycardia in normoxic conditions; however, putative antagonists for these systems failed to prevent or ameliorate hypoxia-induced bradycardia. This suggests that the activation of one or more of these systems is not the primary cause of the observed hypoxia-induced bradycardia. Inhibition of oxidative phosphorylation also decreased HR in normoxic conditions, highlighting the importance of ATP levels. The ß-blocker metoprolol caused a concentration-dependent reduction in HR supporting reports that ß1-adrenergic receptors are present in the early rat embryonic heart. The cAMP inducer colforsin induced a positive chronotropic effect in both normoxic and hypoxic conditions. Overall, the embryonic HR at this stage of development is responsive to the level of oxygenation, probably as a consequence of its influence on ATP production.

A comparison of drug-induced cardiotoxicity in rat embryos cultured in human serum or protein free media.

INTRODUCTION: Although much reproductive toxicology research is performed in live animals there is increasing use of in vitro techniques primarily to identify potential hazards with human exposure. As many in vitro studies are undertaken using protein free media, the standard protocol is to compare the effect concentration determined in vitro with the predicted therapeutic free plasma concentration in humans. The aim of the present study was to test this rationale by comparing the effect of a small number of therapeutic drugs on heart rate of rodent embryos cultured in human sera or protein free serum. METHODS: Whole rat embryos were cultured in protein-free media or human serum to which drugs (amiodarone, citalopram, dofetilide, haloperidol, paroxetine, quetiapine, or trazodone) known to induce embryonic bradycardia were added. Embryonic heart rate was observed before and after addition of drugs. RESULTS: Most of the tested drugs (5/7) caused a greater decrease in embryonic heart rate in human sera than predicted based on the protein binding of the drug. DISCUSSION: The results suggest that there is less unbound drug in the protein free media and/or more unbound drug in the human sera than predicted. Variables such as saturated protein binding and pH cannot fully explain our results. Since the results did not validate the original rationale, reproductive toxicity results obtained using protein free in vitro techniques may not have the large safety factors predicted on the basis of protein binding.

Effects of macrolide antibiotics on rat embryonic heart function in vitro.

The Swedish Medical Product Agency (MPA) has listed erythromycin as a suggested human teratogen, causing cardiovascular malformations. It is further suggested that this may be a class effect of macrolide antibiotics. The proposed teratogenic mechanism is blockade of the human ether-á-go-go-related (hERG)/IKr current in the embryonic heart causing bradycardia and arrhythmia resulting in altered cardiac blood flow and/or embryonic hypoxia. To test this hypothesis, we examined the effect of three macrolide antibiotics on the function of the rat embryonic heart. Gestational day 13 rat embryos in vitro were exposed to erythromycin (25-500 µM), clarithromycin (25-500 µM), or azithromycin (100 µM to 1 mM) for 3 hr. The effect on the embryonic heart was monitored every hour. The results showed that erythromycin and clarithromycin caused a concentration-dependent bradycardia. Twenty-five micromolar was a no-effect concentration for erythromycin and was close to a no-effect concentration for clarithromycin. Azithromycin only caused significant bradycardia at 1 mM. Additional studies were performed with the embryos cultured at 40°C instead of 38°C, to mimic fever. The increased temperature increased the number of arrhythmias but did not worsen the drug-induced bradycardia. The results support the concept that erythromycin and clarithromycin can adversely affect the embryonic heart but only at concentrations well outside expected embryonic exposure in the human.

Therapeutic drugs that slow the heart rate of early rat embryos. Is there a risk for the human?

During the organogenic period of development the cardiovascular system of the embryo fulfills several functions including delivery of oxygen and nutrients and a hemodynamic role necessary for cardiac morphogenesis, angiogenesis and hematopoiesis. It is expected that at each stage of embryonic development there is an ideal embryonic heart rate and contractility that maintains the optimal blood flow and pressure to fulfill these various functions. In vitro rat embryo culture studies have revealed that many therapeutic drugs (antiarrhythmics, antidepressants, antipsychotics and anticonvulsants), that may be taken during human pregnancy, cause a concentrationdependent slowing of the embryonic heart and irregular heart rate at higher concentrations. The concentrations causing bradycardia in vitro are often close to human therapeutic plasma concentrations and raise concern that these drugs can potentially cause embryonic death or malformations, and that current reproductive toxicity testing does not adequately examine possible effects of drugs on the embryo's cardiac function.

The effect on rat embryonic heart rate of Na+, K+, and Ca2+ channel blockers, and the human teratogen phenytoin, changes with gestational age.

In this study, we compared the effects of four ion channel blockers on rat embryonic heart function during the organogenic period from gestational day (GD) 10 to 15, to determine the changes in dependence on ion channels during rat cardiac development. Rat embryos in culture were exposed to either the human ether-á-go-go-related gene potassium channel blocker, dofetilide (400 nM); the sodium channel blocker, lidocaine (250 µM); the L-type calcium channel blocker, nifedipine (1.8 µM); or the multichannel blocker, phenytoin (200 µM). Lidocaine slowed the heart rate (HR) with the effect becoming more severe with increasing GD. Dofetilide slowed the embryonic HR and caused arrhythmias with the most severe effect on GD 11 to 13. Nifedipine primarily caused a negative inotropic effect except on GD 10 when it stopped the heart in most embryos. Phenytoin stopped the heart of most GD 10 to 12 embryos while on GD 13 to 15 phenytoin slowed the heart. The results demonstrate that as the rat heart develops during the organogenic period its functional dependence on ion channels changes markedly. These changes are important for understanding drug effects on the embryo during pregnancy and the methodology used provides a simple procedure for assessing drug effects on the developing heart.

Comparative effects of sodium channel blockers in short term rat whole embryo culture.

This study was undertaken to examine the effect on the rat embryonic heart of two experimental drugs (AZA and AZB) which are known to block the sodium channel Nav1.5, the hERG potassium channel and the l-type calcium channel. The sodium channel blockers bupivacaine, lidocaine, and the l-type calcium channel blocker nifedipine were used as reference substances. The experimental model was the gestational day (GD) 13 rat embryo cultured in vitro. In this model the embryonic heart activity can be directly observed, recorded and analyzed using computer assisted image analysis as it responds to the addition of test drugs. The effect on the heart was studied for a range of concentrations and for a duration up to 3h. The results showed that AZA and AZB caused a concentration-dependent bradycardia of the embryonic heart and at high concentrations heart block. These effects were reversible on washout. In terms of potency to cause bradycardia the compounds were ranked AZB>bupivacaine>AZA>lidocaine>nifedipine. Comparison with results from previous studies with more specific ion channel blockers suggests that the primary effect of AZA and AZB was sodium channel blockage. The study shows that the short-term rat whole embryo culture (WEC) is a suitable system to detect substances hazardous to the embryonic heart.

The teratogenic effect of dofetilide during rat limb development and association with drug-induced bradycardia and hypoxia in the embryo.

BACKGROUND: Dofetilide is an antiarrhythmic drug that blocks the cardiac repolarizing current IKr ((IKr, rapid component of the delayed rectifying potassium current). Previous studies have shown that (a) IKr is essential for normal cardiac function of the embryonic heart and (b) dofetilide is teratogenic in rodents. This study was undertaken to examine the mechanism by which dofetilide causes limb defects on gestational day 13 (GD 13) in the rat. METHODS: Rats were treated with dofetilide (single oral dose, 5 mg/kg) on GD 13 and embryonic heart rates assessed by ultrasound (Vevo770, VisualSonics, Toronto, Ontario, Canada) 2 hr later. Fetuses were examined for malformations on GD 20. In a separate experiment, dofetilide treatment of GD 13 rats was followed 2, 4, 12, or 24 hr with iv dosing with the hypoxia marker, pimonidazole (60 mg/kg). Embryos were collected and heart rates were assessed in vitro and hypoxia in embryo limbs analyzed. RESULTS: A teratogenic dose of dofetilide at a susceptible stage of development (GD 13) resulted in a period of bradycardia and arrhythmia of the embryonic heart and hypoxia in the developing limbs (GD 13) resulting in limb malformations (GD 20). CONCLUSIONS: Drugs that induce periods of bradycardia and/or arrhythmia of the embryonic heart and cause the embryo to become hypoxic are potential human teratogens.

Antidepressants cause bradycardia and heart block in GD 13 rat embryos in vitro.

This study investigated the effects of a range of antidepressant drugs on the heart of gestation day 13 rat embryos in vitro. The general hypothesis was that the drugs would adversely affect the function of the embryonic heart since they all have some cardiac ion channel blocking activity in addition to their main pharmacological effect on neurotransmitters. The results showed that all the tested drugs caused bradycardia in a generally concentration-dependent manner. At higher concentrations most of the drugs caused some degree of heart block consistent with sodium channel blockade and some drugs also showed negative inotropy associated with blockade of the L-type calcium channel. One drug, trazodone, caused arrhythmia consistent with blockade of the hERG (human ether-a-go-go related gene) potassium channel. In general the effects on the embryonic rat heart were only seen at "free drug" concentrations much greater than those likely to occur in pregnant women taking antidepressant medication. The least margin of safety was seen with the tricyclic antidepressants and the serotonin antagonist and reuptake inhibitor trazodone.

The effect of drugs with ion channel-blocking activity on the early embryonic rat heart.

This study investigated the effects of a range of pharmaceutical drugs with ion channel-blocking activity on the heart of gestation day 13 rat embryos in vitro. The general hypothesis was that the blockade of the I(Kr)/hERG channel, that is highly important for the normal functioning of the embryonic rat heart, would cause bradycardia and arrhythmia. Concomitant blockade of other channels was expected to modify the effects of hERG blockade. Fourteen drugs with varying degrees of specificity and affinity toward potassium, sodium, and calcium channels were tested over a range of concentrations. The rat embryos were maintained for 2 hr in culture, 1 hr to acclimatize, and 1 hr to test the effect of the drug. All the drugs caused a concentration-dependent bradycardia except nifedipine, which primarily caused a negative inotropic effect eventually stopping the heart. A number of drugs induced arrhythmias and these appeared to be related to either sodium channel blockade, which resulted in a double atrial beat for each ventricular beat, or I(Kr)/hERG blockade, which caused irregular atrial and ventricular beats. However, it is difficult to make a precise prediction of the effect of a drug on the embryonic heart just by looking at the polypharmacological action on ion channels. The results indicate that the use of the tested drugs during pregnancy could potentially damage the embryo by causing periods of hypoxia. In general, the effects on the embryonic heart were only seen at concentrations greater than those likely to occur with normal therapeutic dosing.

Acardiac fetus: evidence in support of a vascular/hypoxia pathogenesis for isolated oral clefting.

BACKGROUND: The acardiac human fetus represents an accident of monozygotic twinning or higher multiple births due to an artery-to-artery and a vein-to-vein anastomosis in the monochorial placenta. Blood returning to the placenta through the umbilical artery of a normal cotwin is directed into the umbilical artery of the acardiac twin such that blood reaching the cranial end of the embryo is likely to be poorly oxygenated resulting in a number of structural defects including oral clefts. Although retrograde perfusion as a cause of hypoxia is unique to the acardiac fetus, there is ample evidence from animal studies that hypoxia is associated with facial clefting. METHODS: Twenty-six acardiac fetuses were examined at UCSD Medical Center between 1974 and 2003. RESULTS: In 12 of the 26, the cephalic end of the fetus was sufficiently intact to document the structures of the face. Of these, cleft lip +/- palate was present in five and cleft palate alone was present in one. In all six, the oral cleft followed the normal planes of facial closure. The cotwin in all six cases was normal. CONCLUSIONS: This article suggests that decreased blood flow/hypoxia to the cephalic end of the fetus may be an important contributor to the development of cleft lip +/- palate and cleft palate alone in the acardiac fetus and raises the possibility that this may also be a mechanism responsible for oral clefting in singletons.

New proposals for testing drugs with IKr-blocking activity to determine their teratogenic potential.

Drugs blocking the potassium current IKr, either as an intended pharmacologic effect (eg antiarrhythmics dofetilide and almokalant) or as an unwanted side-effect (eg antihistamine astemizole, propulsive drug cisapride, antidepressive drugs and macrolide antibiotics) are potential human teratogens. It is the contention of this paper that the existing repeat dose regimen used in teratology studies to fulfil regulatory requirements, does not properly identify the teratogenic risk of these drugs. Results from conventional studies for dofetilide and almokalant showed high rates of postimplantation embryonic death with few malformed fetuses. For astemizole and cisapride only embryonic death was seen. These latter results were not considered important because they occurred either in the presence of maternal toxicity and/or at high doses. Subsequent studies have shown that IKr-blockers are highly teratogenic when administered on single gestational days (GD) during a sensitive period of rat pregnancy (GD 10-14) when they induce a high incidence of stage-specific malformations. This teratogenic activity of astemizole and cisapride was missed in the original teratology studies. Mechanistically IKr-blockers cause bradycardia and arrhythmia of the embryonic heart and while an embryo may be able to survive a single day exposure to a teratogenic dose, repeat dosing often leads to death of the embryo. With this review we suggest that new drugs identified at the preclinical stage of development as having IKr-blocking properties, should undergo more comprehensive teratology testing including single GD dosing and studies using embryo culture. This would further help identify and characterise their teratogenic potential.

The effect of hypoxia in development.

There is increasing evidence that the oxygen supply to the human embryo in the first trimester is tightly controlled, suggesting that too much oxygen may interfere with development. The use of hypoxia probes in mammalian embryos during the organogenic period indicates that the embryo is normally in a state of partial hypoxia, and this may be essential to control cardiovascular development, perhaps under the control of hypoxia-inducible factor (HIF). A consequence of this state of partial hypoxia is that disturbances in the oxygen supply can more easily lead to a damaging degree of hypoxia. Experimental mammalian embryos show a surprising degree of resilience to hypoxia, with many organogenic stage embryos able to survive 30-60 min of anoxia. However, in some embryos this degree of hypoxia causes abnormal development, particularly transverse limb reduction defects. These abnormalities are preceded by hemorrhage/edema and tissue necrosis. Other parts of the embryo are also susceptible to this hypoxia-induced damage and include the genital tubercle, the developing nose, the tail, and the central nervous system. Other frequently observed defects in animal models of prenatal hypoxia include cleft lip, maxillary hypoplasia, and heart defects. Animal studies indicate that hypoxic episodes in the first trimester of human pregnancy could occur by temporary constriction of the uterine arteries. This could be a consequence of exposure to cocaine, misoprostol, or severe shock, and there is evidence that these exposures have resulted in hypoxia-related malformations in the human. Exposure to drugs that block the potassium current (IKr) can cause severe slowing and arrhythmia of the mammalian embryonic heart and consequently hypoxia in the embryo. These drugs are highly teratogenic in experimental animals. There is evidence that drugs with IKr blockade as a side effect, for example phenytoin, may cause birth defects in the human by causing periods of embryonic hypoxia. The strongest evidence of hypoxia causing birth defects in the human comes from studies of fetuses lacking hemoglobin (Hb) F. These fetuses are thought to be hypoxic from about the middle of the first trimester and show a range of birth defects, particularly transverse limb reduction defects.

The relationship between cleft lip, maxillary hypoplasia, hypoxia and phenytoin.

Cleft lip (CL) is a common malformation that has both genetic and exogenous causes. The main pharmaceutical cause is exposure to phenytoin during early facial development in the 5th to 6th weeks of gestation. Phenytoin also causes CL if administered to pregnant rats during the period of early facial development. Evidence is presented that in the pregnant rat, a teratogenic dose of phenytoin slows the early embryonic heart and causes a prolonged period of embryonic hypoxia. It is proposed that this hypoxia, through an undefined downstream mechanism, leads to the development of CL. The involvement of hypoxia in the pathogenesis of CL is in agreement with studies in mouse strains with a spontaneous rate of CL in which exposure to hypoxia has been shown to increase the rate and hyperoxia to decrease the rate. Other exogenous risk factors during pregnancy for human CL include maternal cigarette smoking, residence at high altitude and exposure to corticosteroids. It is suggested that these exposures all involve an increased risk of embryonic hypoxia. It has been proposed that phenytoin affects the embryonic heart by inhibition of the human-ether-a-go-go (HERG) potassium channel. Phenytoin also inhibits sodium and calcium channels and these properties may also be involved in the observed effect on the embryonic heart. Phenytoin-induced bradycardia leading to embryonic hypoxia may be an important mechanism by which phenytoin causes birth defects.