Alterations in the endocannabinoid system in the rat valproic acid model of autism

The endocannabinoid system plays a crucial role in regulating emotionality and social behaviour, however it is unknown whether this system plays a role in symptoms associated with autism spectrum disorders. The current study evaluated if alterations in the endocannabinoid system accompany behavioural changes in the valproic acid (VPA) rat model of autism. Adolescent rats prenatally exposed to VPA exhibited impaired social investigatory behaviour, hypoalgesia and reduced lococmotor activity on exposure to a novel aversive arena. Levels of the endocananbinoids, anandamide (AEA) and 2-arachidonylglycerol (2-AG) in the hippocampus, frontal cortex or cerebellum were not altered in VPA- versus saline-exposed animals. However, the expression of mRNA for diacylglycerol lipase α, the enzyme primarily responsible for the synthesis of 2-AG, was reduced in the cerebellum of VPA-exposed rats. Furthermore, while the expression of mRNA for the 2-AG-catabolising enzyme monoacylglycerol lipase was reduced, the activity of this enzyme was increased, in the hippocampus of VPA-exposed animals. CB1 or CB2 receptor expression was not altered in any of the regions examined, however VPA-exposed rats exhibited reduced PPARα and GPR55 expression in the frontal cortex and PPARγ and GPR55 expression in the hippocampus, additional receptor targets of the endocannabinoids. Furthermore, tissue levels of the fatty acid amide hydrolase substrates, AEA, oleoylethanolamide and palmitoylethanolamide, were higher in the hippocampus of VPA-exposed rats immediately following social exposure. These data indicate that prenatal VPA exposure is associated with alterations in the brain's endocannabinoid system and support the hypothesis that endocannabinoid dysfunction may underlie behavioural abnormalities observed in autism spectrum disorders.

The endocannabinoid system in the rat dorsolateral periaqueductal grey mediates fear-conditioned analgesia and controls fear expression in the presence of nociceptive tone

BACKGROUND AND PURPOSE

Endocannabinoids in the midbrain periaqueductal grey (PAG) modulate nociception and unconditioned stress-induced analgesia; however, their role in fear-conditioned analgesia (FCA) has not been examined. The present study examined the role of the endocannabinoid system in the dorsolateral (dl) PAG in formalin-evoked nociceptive behaviour, conditioned fear and FCA in rats.

EXPERIMENTAL APPROACH

Rats received intra-dlPAG administration of the CB(1) receptor antagonist/inverse agonist rimonabant, or vehicle, before re-exposure to a context paired 24 h previously with foot shock. Formalin-evoked nociceptive behaviour and fear-related behaviours (freezing and 22 kHz ultrasonic vocalization) were assessed. In a separate cohort, levels of endocannabinoids [2-arachidonoyl glycerol (2-AG) and N-arachidonoyl ethanolamide (anandamide; AEA)] and the related N-acylethanolamines (NAEs) [N-palmitoyl ethanolamide (PEA) and N-oleoyl ethanolamide (OEA)] were measured in dlPAG tissue following re-exposure to conditioned context in the presence or absence of formalin-evoked nociceptive tone.

KEY RESULTS

Re-exposure of rats to the context previously associated with foot shock resulted in FCA. Intra-dlPAG administration of rimonabant significantly attenuated FCA and fear-related behaviours expressed in the presence of nociceptive tone. Conditioned fear without formalin-evoked nociceptive tone was associated with increased levels of 2-AG, AEA, PEA and OEA in the dlPAG. FCA was specifically associated with an increase in AEA levels in the dlPAG.

CONCLUSIONS AND IMPLICATIONS

Conditioned fear to context mobilises endocannabinoids and NAEs in the dlPAG. These data support a role for endocannabinoids in the dlPAG in mediating the potent suppression of pain responding which occurs during exposure to conditioned aversive contexts.

LINKED ARTICLES

This article is part of a themed section on Cannabinoids in Biology and Medicine. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2012.165.issue-8. To view Part I of Cannabinoids in Biology and Medicine visit http://dx.doi.org/10.1111/bph.2011.163.issue-7.

A population-based study of prostate cancer chemotherapy

The use of chemotherapy in the treatment of prostate cancer is a relatively recent development, with no published data on the patterns of care in the UK. We carried out a population-based study to assess variation in the use of prostate cancer chemotherapy over time in a UK cancer network.

Mumps outbreaks in four universities in the North West of England: prevention, detection and response

Evidence suggests that primary and secondary vaccine failure have contributed to recent university-based mumps outbreaks. We describe the epidemiology and public health management of two such outbreaks that occurred simultaneously in two areas of the North West of England, affecting four universities, using data from routine surveillance, serology testing, and telephone interviews and electronic questionnaires. Vaccination status was obtained from GP records. Cases were predominantly first year students living in university halls of residence. Public health response involved active surveillance, isolation advice and targeted vaccination clinics. Many students lack natural immunity and mumps vaccination. Factors hindering the public health response include delayed notifications, inability to readily define the 'at risk' population, low vaccine uptake, and lack of an evidence-based, cost effective strategy.

[Sentinel node procedure in head and neck cutaneous melanoma]

INTRODUCTION

Sentinel lymph node (SLN) biopsy is frequently discussed in the management of cutaneous melanoma, especially in head and neck localizations where SLN biopsy is much more demanding. The benefits of SLN protocol are not proved yet. The aim of our study was to present our experience of SLN biopsy in head and neck cutaneous melanoma.

PATIENTS AND METHODS

This retrospective study included all patients managed for head and neck malignant melanoma from 2002 to 2006. We reviewed the technique, implementation and difficulties of the procedure, postoperative outcome, and complications.

RESULTS

Nineteen patients were included. An average of 2.2 lymph nodes were localized per patient using lymphoscintigraphy. Biopsy was impossible for one patient because the deep spinal node was not found. An average of 1.2 nodes was biopsied per patient. One patient presented with micrometastases. Another presented with lymphorrhea.

DISCUSSION

Sentinel node biopsy is widely performed in the management of cutaneous melanoma but remains an option for these indications in the last update of the French Society of Dermatology. SLN biopsy is difficult to implement because of the complexity of head and neck lymphatic system.

ARRDC3 suppresses breast cancer progression by negatively regulating integrin beta4

Large-scale genetic analyses of human tumor samples have been used to identify novel oncogenes, tumor suppressors and prognostic factors, but the functions and molecular interactions of many individual genes have not been determined. In this study we examined the cellular effects and molecular mechanism of the arrestin family member, ARRDC3, a gene preferentially lost in a subset of breast cancers. Oncomine data revealed that the expression of ARRDC3 decreases with tumor grade, metastases and recurrences. ARRDC3 overexpression represses cancer cell proliferation, migration, invasion, growth in soft agar and in vivo tumorigenicity, whereas downregulation of ARRCD3 has the opposite effects. Mechanistic studies showed that ARRDC3 functions in a novel regulatory pathway that controls the cell surface adhesion molecule, β-4 integrin (ITGβ4), a protein associated with aggressive tumor behavior. Our data indicates ARRDC3 directly binds to a phosphorylated form of ITGβ4 leading to its internalization, ubiquitination and ultimate degradation. The results identify the ARRCD3-ITGβ4 pathway as a new therapeutic target in breast cancer and show the importance of connecting genetic arrays with mechanistic studies in the search for new treatments.

Droplet motion in microfluidic networks: Hydrodynamic interactions and pressure-drop measurements

We present experimental, numerical, and theoretical studies of droplet flows in hydrodynamic networks. Using both millifluidic and microfluidic devices, we study the partitioning of monodisperse droplets in an asymmetric loop. In both cases, we show that droplet traffic results from the hydrodynamic feedback due to the presence of droplets in the outlet channels. We develop a recently-introduced phenomenological model [W. Engl, Phys. Rev. Lett. 95, 208304 (2005)] and successfully confront its predictions to our experimental results. This approach offers a simple way to measure the excess hydrodynamic resistance of a channel filled with droplets. We discuss the traffic behavior and the variations in the corresponding hydrodynamic resistance length L_{d} and of the droplet mobility beta , as a function of droplet interdistance and confinement for channels having circular or rectangular cross sections.

[Medical disorders and pregnancy. Gastrointestinal, neurological, cardiovascular and dermatological disorders]

A pregnant woman can present medical pathologies similar to a woman who is not pregnant. However, the clinical features of some pathologies and the diagnostic or therapeutic process might be altered due to changes produced by pregnancy and the presence of the foetus. In some cases this can limit the diagnostic methods or the therapies to be applied. This article sets out the digestive and cardiovascular pathologies, pathologies of the nervous system and dermatoses of greatest relevance due to their frequency or severity, which might be encountered in an emergency consultation. It also offers a practical approach for the initial handling and the prognosis for the mother and the foetus.

[Medical disorders and pregnancy. Respiratory, urologic, infectious and endocrinologic disorders]

Pregnancy is a state that changes the physiology of various organs and systems. The occurrence of concomitant diseases, or their presence prior to pregnancy, requires an understanding of such changes and their influence on the disease, the impact of the disease and the diagnostic and therapeutic measures on pregnant women and on the foetus. The aim of this paper is to provide a concise outline of the course of action recommended in dealing with pregnant women who attend the emergency department presenting symptoms of non-specific morbidity of pregnancy. Some of the most frequent pathologies classified by systems are presented.