An international network (PlaNet) to evaluate a human placental testing platform for chemicals safety testing in pregnancy.

The human placenta is a critical life-support system that nourishes and protects a rapidly growing fetus; a unique organ, species specific in structure and function. We consider the pressing challenge of providing additional advice on the safety of prescription medicines and environmental exposures in pregnancy and how ex vivo and in vitro human placental models might be advanced to reproducible human placental test systems (HPTSs), refining a weight of evidence to the guidance given around compound risk assessment during pregnancy. The placental pharmacokinetics of xenobiotic transfer, dysregulated placental function in pregnancy-related pathologies and influx/efflux transporter polymorphisms are a few caveats that could be addressed by HPTSs, not the specific focus of current mammalian reproductive toxicology systems. An international consortium, "PlaNet", will bridge academia, industry and regulators to consider screen ability and standardisation issues surrounding these models, with proven reproducibility for introduction into industrial and clinical practice.

Post traumatic stress disorder, neuroscience, and the law.

Post-Traumatic Stress Disorder (PTSD) is a complex psychiatric condition, the effects of which can be seriously debilitating. As it originates from a specific traumatic event, it often impacts soldiers and victims of violent crime. It is currently one of the most frequently litigated mental diseases. Neuroscience is slowly discovering the neural bases of PTSD and other psychiatric ailments and is building tests to distinguish actual patients from non-suffering individuals. We examine the current state of neuroscientific research on PTSD and its biomarkers, focusing on a recent experiment by Apostolos Georgopoulos and coworkers. Then we analyze the legal consequences of these scientific advances, both in civil and criminal law, from a comparative perspective. Neuro-technology is likely to provide courts with a new kind of evidence, which will not replace but add to older behavioral evidence. Furthermore, it will weaken the so far standing distinction between physical and emotional harm. However, even extremely sensitive tests (>95%) can have insufficient accuracy if the prevalence of a condition in the tested population is low. Therefore, the law ought to take into account the prevalence of PTSD and other psychiatric conditions when the decision whether to admit neuro-evidence in courts or not is made.

Fetal cerebral energy metabolism and electrocardiogram during experimental umbilical cord occlusion and resuscitation.

OBJECTIVE: The purpose of this experimental study was to elucidate alterations in fetal energy metabolism in relation to ECG changes during extreme fetal asphyxia, postnatal resuscitation and the immediate post-resuscitatory phase. STUDY DESIGN: Five near-term fetal sheep were subjected to umbilical cord occlusion until cardiac arrest followed by delivery, resuscitation and postnatal pressure-controlled ventilation. Four sheep served as sham controls and were delivered immediately after ligation of the umbilical cord. Fetal ECG was analysed online for changes of the ST segment. Fetal metabolism was monitored by intracerebral and subcutaneous microdialysis catheters. RESULTS: Fetal ECG reacted on cord occlusion with an increase in the T-wave height followed by changes in intracerebral levels of oxidative parameters. Cerebral lactate/pyruvate ratio and glutamate increased to median (range) of 240 (200-744) and 34.0 (22.6-60.5) mmol/l, respectively; both parameters returned to baseline after resuscitation. Cerebral glucose decreased to 0.1 (0.08-0.12) mmol/l after occlusion and increased above baseline upon resuscitation. In subcutaneous tissue as well as blood the increase in lactate occurred with a delay compared to cerebral levels. CONCLUSION: The fetal ECG changes related to asphyxia preceded the increase in excitotoxicity as determined by increase in cerebral glutamate during asphyxia. Cerebral lactate increase was superior to subcutaneous lactate increase.

Monoamine transporters in human endometrium and decidua.

BACKGROUND: Monoamines play important roles in decidualization, implantation, immune modulation and inflammation. Furthermore, monoamines are potent vasoactive mediators that regulate blood flow and capillary permeability. Regulation of the uterine blood flow is important both during menstruation and pregnancy. Adequate monoamine concentrations are essential for a proper implantation and physiological development of pregnancy. Unlike most transmitter substances, monoamines are recycled by monoamine transporters rather than enzymatically inactivated. Their intracellular fate is influenced by their lower affinity for inactivating enzymes than for vesicular transporters located in intracellular vesicles. Thus, cells are capable not only of recapturizing and degrading monoamines, but also of storing and releasing them in a controlled fashion. METHODS: The general objective of the present review is to summarize the role of the monoamine transporters in the female human reproduction. Since the transporter proteins critically regulate extracellular monoamine concentrations, knowledge of their distribution and cyclic variation is of great importance for a deeper understanding of the contribution of monoaminergic mechanisms in the reproductive process. MEDLINE was searched for relevant publications from 1950 to 2007. RESULTS: Two families of monoamine transporters, neuronal and extraneuronal monoamine transporters, are present in the human endometrium and deciduas. CONCLUSIONS: New knowledge about monoamine metabolism in the endometrium during menstruation and pregnancy will increase understanding of infertility problems and may offer new pharmacological approaches to optimize assisted reproduction.

The organic cation transporters (OCT1, OCT2, EMT) and the plasma membrane monoamine transporter (PMAT) show differential distribution and cyclic expression pattern in human endometrium and early pregnancy decidua.

The non-neuronal monoamine transporters (OCT1, OCT2, EMT, and PMAT) play a key role in the clearance of monoamines from extracellular compartments. In a previous report we described endometrial distribution and cyclic variation of the vesicular monoamine transporter (VMAT2) mRNA and the neuronal norepinephrine transporter (NET) mRNA. In the present study we used in situ hybridization, real-time PCR and immunohistochemistry to reveal tissue distribution and cyclic variation of mRNA for the non-neuronal monoamine transporters in the human endometrium and early pregnancy decidua. We found that non-neuronal monoamine transporters are predominantly expressed in the stroma. The plasma membrane monoamine transporter (PMAT) mRNA expression peaked in the proliferative phase, whereas the extra-neuronal monoamine transporter (EMT) mRNA expression peaked in the secretory phase. The organic cation transporter 2 (OCT2) mRNA expression was exclusively detected in few scattered stromal cells and OCT1 mRNA was not detected at all. Our present results demonstrate that PMAT, EMT, and OCT2 transporters are expressed in the endometrial stroma and can potentially regulate reuptake of monoamines in general and histamine in particular. Taken together with our previous finding of VMAT2 mRNA in epithelial cells, we suggest a paracrine interaction between stromal and epithelial cells, which may modulate certain steps of the reproductive process.

Histamine uptake by human endometrial cells expressing the organic cation transporter EMT and the vesicular monoamine transporter-2.

Cellular reuptake of monoamines, which is mediated by cell membrane transporters, is followed by accumulation in vesicles by vesicular monoamine transporters (VMAT). The aim of this study was to demonstrate the presence of functional monoamine transporters with high affinity for histamine in human endometrial tissue, since histamine has been implicated as a paracrine signal during endometrial decidualization and embryo implantation. In situ hybridization with (35)S-labelled cRNA probes was used for detection of the organic cationic transporter-2 (OCT-2), the extraneuronal monoamine transporter (EMT), and VMAT-2 in cryosections of normal human endometrial tissue. To identify functional transporters for histamine in endometrial cells, we incubated primary cultures of stromal cells and cultures of attached glands with (3)H-labelled histamine. Cultures were pretreated with either corticosterone, a specific inhibitor of EMT, or reserpine, a specific inhibitor of VMAT-2. EMT mRNA was localized in the stroma with peak expression in the secretory phase, whereas OCT-2 mRNA was expressed by few cells in the stroma throughout the cycle. VMAT-2 mRNA was localized in the stroma during the proliferative phase and in the epithelium during the secretory phase. Thus, EMT and VMAT-2, which both have high affinity for histamine, are strongly expressed in endometrial cells. Both corticosterone and reserpine significantly reduced the uptake of (3)H-histamine in stromal cells during the proliferative as well as the secretory phase. This indicates the presence of functional EMT and VMAT-2 transporter proteins throughout the cycle, even though their periods of maximal mRNA expression were limited. The results of uptake experiments with glandular epithelial cells confirmed not only the presence of functional VMAT-2 transporter protein in the secretory phase but also the absence of a histamine-specific plasma membrane transporter throughout the cycle. Thus, endometrial tissue contains both plasma membrane and vesicular membrane monoamine transporters with high affinity for histamine. They can potentially influence the reproductive process by the uptake of extracellular histamine and subsequent release on demand.

Plasma membrane and vesicular monoamine transporters in normal endometrium and early pregnancy decidua.

The uterus is innervated by adrenergic sympathetic fibres, and the endometrium has a capability for endogenous monoamine synthesis. Extracellular monoamine levels are regulated primarily through re-uptake by specific membrane-bound transporter proteins dopamine transporter (DAT), norepinephrine transporter (NET) and serotonin transporter (SERT). Intracellular storage of monoamines involves vesicular transporter proteins (VMAT1 and VMAT2). This study explored gene expression of the monoamine transporters in normal endometrium throughout the menstrual cycle and early decidua. In-situ hybridization histochemistry revealed three general classes of expression patterns: (i). epithelial expression of NET mRNA; (ii). increasing stromal expression of VMAT2 mRNA in the proliferative phase; and (iii). increasing epithelial expression of VMAT2 mRNA during the secretory phase. Real time PCR showed low expression levels of NET in all phases of the endometrial cycle and a higher expression of VMAT2 mRNA in the mid-secretory phase. Our results suggest that several monoamine transporters may have menstrual cycle phase-specific functions in endometrial biology by maintaining adequate levels of monoamines. Re-uptake and regulated release of monoamines may also modulate several steps of the reproductive processes such as embryo implantation and decidua formation.