Dissecting spatial knowledge from spatial choice by hippocampal NMDA receptor deletion

Hippocampal NMDA receptors (NMDARs) and NMDAR-dependent synaptic plasticity are widely considered crucial substrates of long-term spatial memory, although their precise role remains uncertain. Here we show that Grin1(ΔDGCA1) mice, lacking GluN1 and hence NMDARs in all dentate gyrus and dorsal CA1 principal cells, acquired the spatial reference memory water maze task as well as controls, despite impairments on the spatial reference memory radial maze task. When we ran a spatial discrimination water maze task using two visually identical beacons, Grin1(ΔDGCA1) mice were impaired at using spatial information to inhibit selecting the decoy beacon, despite knowing the platform's actual spatial location. This failure could suffice to impair radial maze performance despite spatial memory itself being normal. Thus, these hippocampal NMDARs are not essential for encoding or storing long-term, associative spatial memories. Instead, we demonstrate an important function of the hippocampus in using spatial knowledge to select between alternative responses that arise from competing or overlapping memories.     

Synthesis, biological evaluation and molecular modeling of GW 501516 analogues

Eleven analogues of GW 501516 (1) were prepared and subjected to biological testing in a semi-high throughput human skeletal muscle cell assay. The assay testing indicated that all analogues elicited oxidation of oleic acid. Among the most potent agonists, 2e (2-{2-ethyl-4-[(4-methyl-2-(4-trifluoromethylphenyl)thiazol-5-yl)methylthio]phenoxy}-2-methylpropanoic acid), was also subjected to a luciferase-based transfection assay, which showed that this compound is a potent agonist against PPARδ and a moderate agonist against PPARα. Docking of compound 2e into PPARδ revealed that it occupied the agonist binding site and exhibited key hydrogen bonding interactions with His323, His449, and Tyr473.     

Acute pain relief in children: use of rating scales and analgesia

Evidence suggests that children who are in pain and who present to emergency departments receive sub-optimal pain assessment and relief. Many factors contribute to this unacceptable quality of care, including emergency nurses' lack of knowledge about the appropriate pain assessment tools. This article refers to a literature review and case study to discuss children's pain assessment tools. It concludes that an education programme for emergency nurses could be provided to augment their awareness of best practice pain assessment and management guidelines.     

Aquaporin-4 regulates extracellular space volume dynamics during high-frequency synaptic stimulation: a gene deletion study in mouse hippocampus

Little is known about the physiological roles of aquaporin-4 (AQP4) in the central nervous system. AQP4 water channels are concentrated in endfeet membranes of astrocytes but also localize to the fine astrocytic processes that abut central synapses. Based on its pattern of expression, we predicted that AQP4 could be involved in controlling water fluxes and changes in extracellular space (ECS) volume that are associated with activation of excitatory pathways. Here, we show that deletion of Aqp4 accentuated the shrinkage of the ECS that occurred in the mouse hippocampal CA1 region during activation of Schaffer collateral/commissural fibers. This effect was found in the stratum radiatum (where perisynaptic astrocytic processes abound) but not in the pyramidal cell layer (where astrocytic processes constitute but a minor volume fraction). For both genotypes the ECS shrinkage was most pronounced in the pyramidal cell layer. Our data attribute a physiological role to AQP4 and indicate that this water channel regulates extracellular volume dynamics in the mammalian brain.     

The occurrence of non-anatomical therapeutic chemical-international nonproprietary name molecules in suspected illegal or illegally traded health products in Europe: A retrospective and prospective study

The General European Official Medicines Control Laboratory (OMCL) Network (GEON), co-ordinated by the European Directorate for the Quality of Medicines & HealthCare (EDQM), regularly organises market surveillance studies on specific categories of suspected illegal or illegally traded products. These studies are generally based on a combination of retrospective and prospective data collection over a defined period of time. This paper reports the results of the most recent study in this context with the focus on health products containing non-Anatomical Therapeutic Chemical-International Nonproprietary Name (ATC-INN) molecules. In total 1104 cases were reported by 16 countries for the period between January 2017 and the end of September 2019. The vast majority of these samples (83%) were collected from the illegal market, while only 3% originated from a legal source. For the rest of the samples, categorisation was not possible. Moreover, 69% of all the reported samples were presented as medicines, including sexual performance enhancers, sports performance enhancers, physical performance enhancers and cognitive enhancers or nootropic molecules that act on the central nervous system (CNS). Although the popularity of anabolics, PDE-5 inhibitors and CNS drugs in illegal products has already been reported, the study showed some new trends and challenges. Indeed, 11% of the samples contained molecules of biological origin, that is, research peptides, representing the second most reported category in this study. Furthermore, the study also clearly shows the increasing popularity of Selective Androgen Receptor Modulators and nootropics, two categories that need attention and should be further monitored.     

Estrogen receptor expression and gene promoter methylation in non-small cell lung cancer - a short report

Purpose

In the past, anomalous estrogen receptor (ER) regulation has been associated with various lung pathologies, but so far its involvement in lung cancer initiation and/or progression has remained unclear. Here, we aimed at assessing in vivo and in vitro ER expression and its possible epigenetic regulation in non-small cell lung cancer (NSCLC) samples and their corresponding normal tissues and cells.

Methods

ERα and ERβ gene expression levels were assessed using real time quantitative PCR (RT-qPCR), whereas ERα and ERβ gene promoter methylation levels were assessed using DNA bisulfite conversion followed by pyrosequencing. We included NSCLC (n = 87) and adjacent histologically normal lung tissue samples from lung cancer patients (n = 184), primary normal bronchial epithelial-derived cell cultures (n = 11), immortalized bronchial epithelial-derived cell lines (n = 3) and NSCLC derived cell lines (n = 9).

Results

Using RT-qPCR we found significantly lower ERα and ERβ expression levels in the NSCLC tissue samples compared to their normal adjacent tissue samples. These lower ER expression levels were confirmed in vitro using primary normal bronchial epithelial-derived cell cultures, immortalized bronchial epithelial-derived cell lines and NSCLC-derived cell lines. By using this latter panel of cells, we found that ER gene promoter hypermethylation was associated with decreased ER expression. In addition we found that in tumor and normal lung tissues, smoking was associated with decreased ER expression and that normal lung tissues with a low ERβ expression level exhibited increased smoking-related DNA adducts.

Conclusions

Taken together, our results indicate that decreased ER expression mediated by DNA methylation may play a role in NSCLC development.

     

Steroid secretion following exposure of ovarian follicular cells to three different natural mixtures of persistent organic pollutants (POPs)

This study investigated in vitro endocrine disrupting effects of three mixtures of POPs: 'Marine mix' extracted from Atlantic cod liver, and two mixtures extracted from burbot liver, 'Mj?sa mix' and 'Losna mix'. The POP mixtures were chemically characterized. Co-culture of theca and granulosa cells, were exposed for 48h with different doses of 'Marine mix', 'Mj?sa mix' or 'Losna mix'. As an end point cell viability was determinated by LDH test, steroid analysis by EIA and caspase-3 by colorimetric substrate. Chemical characterization of the mixtures demonstrated that the 'Marine mix' contained high levels of DDTs and PCBs. In the 'Mj?sa mix', the dominant pollutants were BDEs and HBCD. The concentrations of POPs measured in the 'Losna mix' were considerably lower. All mixtures used in the present study had a stimulatory effect on testosterone and estradiol secretion with 'Marine mix'>'Mj?sa mix'>'Losna mix'. These results show that even a mixture containing background concentrations of POPs significantly affected steroid secretion. A higher steroidogenic response in low dose ranges, compared with high dose ranges indicated xenobiotic-conditioning hormesis. This could complicate predictions of effects in risk assessments.