Maturation-dependent effects of chlorpyrifos and parathion and their oxygen analogs on acetylcholinesterase and neuronal and glial markers in aggregating brain cell cultures.

An in vitro model, the aggregating brain cell culture of fetal rat telencephalon, has been used to study the maturation-dependent sensitivity of brain cells to two organophosphorus pesticides (OPs), chlorpyrifos and parathion, and to their oxon derivatives. Immature (DIV 5-15) or differentiated (DIV 25-35) brain cells were treated continuously for 10 days. Acetylcholinesterase (AChE) inhibitory potency for the OPs was compared to that of eserine (physostigmine), a reversible AChE inhibitor. Oxon derivatives were more potent AChE inhibitors than the parent compounds, and parathion was more potent than chlorpyrifos. No maturation-dependent differences for AChE inhibition were found for chlorpyrifos and eserine, whereas for parathion and paraoxon there was a tendency to be more effective in immature cultures, while the opposite was true for chlorpyrifos-oxon. Toxic effects, assessed by measuring protein content as an index of general cytotoxicity, and various enzyme activities as cell-type-specific neuronal and glial markers (ChAT and GAD, for cholinergic and GABAergic neurons, respectively, and GS and CNP, for astrocytes and oligodendrocytes, respectively) were only found at more than 70% of AChE inhibition. Immature compared to differentiated cholinergic neurons appeared to be more sensitive to OP treatments. The oxon derivates were found to be more toxic on neurons than the parent compounds, and chlorpyrifos was more toxic than parathion. Eserine was not neurotoxic. These results indicate that inhibition of AChE remains the most sensitive macromolecular target of OP exposure, since toxic effects were found at concentrations in which AChE was inhibited. Furthermore, the compound-specific reactions, the differential pattern of toxicity of OPs compared to eserine, and the higher sensitivity of immature brain cells suggest that the toxic effects and inhibition of AChE are unrelated.

Copy number variation characteristics in subpopulations of patients with autism spectrum disorders.

Autism spectrum disorders (ASDs) are a heterogeneous group of disorders with a complex genetic etiology. We used high-resolution whole genome array-based comparative genomic hybridization (array-CGH) to screen 223 ASD patients for gene dose alterations associated with susceptibility for autism. Clinically significant copy number variations (CNVs) were identified in 18 individuals (8%), of which 9 cases (4%) had de novo aberrations. In addition, 20 individuals (9%) were shown to have CNVs of unclear clinical relevance. Among these, 13 cases carried rare but inherited CNVs that may increase the risk for developing ASDs, while parental samples were unavailable in the remaining seven cases. Classification of all patients into different phenotypic and inheritance pattern groups indicated the presence of different CNV patterns in different patient groups. Clinically relevant CNVs were more common in syndromic cases compared to non-syndromic cases. Rare inherited CNVs were present in a higher proportion of ASD cases having first- or second-degree relatives with an ASD-related neuropsychiatric phenotype in comparison with cases without reported heredity (P = 0.0096). We conclude that rare CNVs, encompassing potential candidate regions for ASDs, increase the susceptibility for the development of ASDs and related neuropsychiatric disorders giving us further insight into the complex genetics underlying ASDs.

Transition from pediatric to adult health care: expectations of adolescents with chronic disorders and their parents.

The aim of this study was to assess the expectations of adolescents with chronic disorders with regard to transition from pediatric to adult health care and to compare them with the expectations of their parents. A cross-sectional study was carried out including 283 adolescents with chronic disorders, aged 14-25 years (median age, 16.0 years), and not yet transferred to adult health care, and their 318 parents from two university children's hospitals. The majority of adolescents and parents (64%/70%) perceived the ages of 18-19 years and older as the best time to transfer to adult health care. Chronological age and feeling too old to see a pediatrician were reported as the most important decision factors for the transfer while the severity of the disease was not considered important. The most relevant barriers were feeling at ease with the pediatrician (45%/38%), anxiety (20%/24%), and lack of information about the adult specialist and health care (18%/27%). Of the 51% of adolescents with whom the pediatric specialist had spoken about the transfer, 53% of adolescents and 69% of parents preferred a joint transfer meeting with the pediatric and adult specialist, and 24% of these adolescents declared that their health professional had offered this option. In summary, the age preference for adolescents with chronic disorders and their parents to transfer to adult health care was higher than the upper age limits for admission to pediatric health care in many European countries. Anxiety and a lack of information of both adolescents and their parents were among the most important barriers for a smooth and timely transfer according to adolescents and parents.

Frequent users of emergency departments present very high prevalence of mental health and substance use disorders, which are largery underdiagnosed by clinicians.

Background: The objective of this study was to determine if mental health and substance use diagnoses were equally detected in frequent users (FUs) compared to infrequent users (IUs) of emergency departments (EDs). Methods: In a sample of 399 adult patients (>= 18 years old) admitted to a teaching hospital ED, we compared the mental health and substance use disorders diagnoses established clinically and consigned in the medical files by the ED physicians to data obtained in face-to-face research interviews using the Primary Care Evaluation of Mental Disorders (PRIME-MD) and the Alcohol, Smoking and Involvement Screening Test (ASSIST). Between November 2009 and June 2010, 226 FUs (>4 visits within a year) who attended the ED were included, and 173 IUs (<= 4 visits within a year) were randomly selected from a pool of identified patients to comprise the comparison group. Results: For mental health disorders identified by the PRIME-MD, FUs were more likely than IUs to have an anxiety (34 vs. 16%, Chi2(1) = 16.74, p <0.001), depressive (47 vs. 25%, Chi2(1) = 19.11, p <0.001) or posttraumatic stress (PTSD) disorder (11 vs. 5%, Chi2(1) = 4.87, p = 0.027). Only 3/76 FUs (4%) with an anxiety disorder, 16/104 FUs (15%) with a depressive disorder and none of the 24 FUs with PTSD were detected by the ED medical staff. None of the 27 IUs with an anxiety disorder, 6/43 IUs (14%) with a depressive disorder and none of the 8 IUs with PTSD were detected. For substance use disorders identified by the ASSIST, FUs were more at risk than IUs for alcohol (24 vs. 7%, Chi2(1) = 21.12, p <0.001) and drug abuse/dependence (36 vs. 25%, Chi2(1) = 5.52, p = 0.019). Of the FUs, 14/54 (26%) using alcohol and 8/81 (10%) using drugs were detected by the ED physicians. Of the IUs, 5/12 (41%) using alcohol and none of the 43 using drugs were detected. Overall, there was no significant difference in the rate of detection of mental health and substance use disorders between FUs and IUs (Fisher's Exact Test: anxiety, p = 0.567; depression, p = 1.000; PTSD, p = 1.000; alcohol, p = 0.517; and drugs, p = 0.053). Conclusions: While the prevalence of mental health and substance use disorders was higher among FUs, the rates of detection were not significantly different for FUs vs. IUs. However, it may be that drug disorders among FUs were more likely to be detected.

Revising the Cannabis Use Disorders Identification Test (CUDIT) by means of Item Response Theory.

Cannabis use among adolescents and young adults has become a major public health challenge. Several European countries are currently developing short screening instruments to identify 'problematic' forms of cannabis use in general population surveys. One such instrument is the Cannabis Use Disorders Identification Test (CUDIT), a 10-item questionnaire based on the Alcohol Use Disorders Identification Test. Previous research found that some CUDIT items did not perform well psychometrically. In the interests of improving the psychometric properties of the CUDIT, this study replaces the poorly performing items with new items that specifically address cannabis use. Analyses are based on a sub-sample of 558 recent cannabis users from a representative population sample of 5722 individuals (aged 13-32) who were surveyed in the 2007 Swiss Cannabis Monitoring Study. Four new items were added to the original CUDIT. Psychometric properties of all 14 items, as well as the dimensionality of the supplemented CUDIT were then examined using Item Response Theory. Results indicate the unidimensionality of CUDIT and an improvement in its psychometric performance when three original items (usual hours being stoned; injuries; guilt) are replaced by new ones (motives for using cannabis; missing out leisure time activities; difficulties at work/school). However, improvements were limited to cannabis users with a high problem score. For epidemiological purposes, any further revision of CUDIT should therefore include a greater number of 'easier' items.

Ammonia toxicity to the brain.

Hyperammonemia can be caused by various acquired or inherited disorders such as urea cycle defects. The brain is much more susceptible to the deleterious effects of ammonium in childhood than in adulthood. Hyperammonemia provokes irreversible damage to the developing central nervous system: cortical atrophy, ventricular enlargement and demyelination lead to cognitive impairment, seizures and cerebral palsy. The mechanisms leading to these severe brain lesions are still not well understood, but recent studies show that ammonium exposure alters several amino acid pathways and neurotransmitter systems, cerebral energy metabolism, nitric oxide synthesis, oxidative stress and signal transduction pathways. All in all, at the cellular level, these are associated with alterations in neuronal differentiation and patterns of cell death. Recent advances in imaging techniques are increasing our understanding of these processes through detailed in vivo longitudinal analysis of neurobiochemical changes associated with hyperammonemia. Further, several potential neuroprotective strategies have been put forward recently, including the use of NMDA receptor antagonists, nitric oxide inhibitors, creatine, acetyl-L-carnitine, CNTF or inhibitors of MAPKs and glutamine synthetase. Magnetic resonance imaging and spectroscopy will ultimately be a powerful tool to measure the effects of these neuroprotective approaches.

Clinical Proton MR Spectroscopy in Central Nervous System Disorders.

A large body of published work shows that proton (hydrogen 1 [(1)H]) magnetic resonance (MR) spectroscopy has evolved from a research tool into a clinical neuroimaging modality. Herein, the authors present a summary of brain disorders in which MR spectroscopy has an impact on patient management, together with a critical consideration of common data acquisition and processing procedures. The article documents the impact of (1)H MR spectroscopy in the clinical evaluation of disorders of the central nervous system. The clinical usefulness of (1)H MR spectroscopy has been established for brain neoplasms, neonatal and pediatric disorders (hypoxia-ischemia, inherited metabolic diseases, and traumatic brain injury), demyelinating disorders, and infectious brain lesions. The growing list of disorders for which (1)H MR spectroscopy may contribute to patient management extends to neurodegenerative diseases, epilepsy, and stroke. To facilitate expanded clinical acceptance and standardization of MR spectroscopy methodology, guidelines are provided for data acquisition and analysis, quality assessment, and interpretation. Finally, the authors offer recommendations to expedite the use of robust MR spectroscopy methodology in the clinical setting, including incorporation of technical advances on clinical units. © RSNA, 2014 Online supplemental material is available for this article.

Role of PPARβ in keratinocyte adhesion and migration during skin wound healing

RESUME L'homéostasie du tissu cutané est assurée par des interactions étroites entre les cellules le composant et par l'équilibre entre la différenciation et la prolifération des kératinocytes devant permettre un renouvellement constant du tissu. Après une blessure, les kératinocytes environnant la zone blessée sont activés par des cytokines. Ils acquièrent alors un phénotype migratoire qui s'accompagne d'une modulation de l'activité protéolytique de la matrice extra cellulaire, d'une modulation de la dynamique du cytosquelette d'active, de la polarisation de la cellule, de l'affaiblissement des contacts entre cellules et de changements dans leurs contacts avec la matrice extra cellulaire. PPARβ est un facteur de transcription activé par les acides gras et leurs dérivés. Il appartient à la famille des récepteurs nucléaires aux hormones et son expression est avérée dans les kératinocytes des follicules pileux et dans les kératinocytes inter-folliculaires activés par la blessure cutanée. Le rôle de PPARβ dans la peau est principalement lié à son effet protecteur contre l'apoptose ainsi qu'à son implication dans l'équilibre dynamique entre la prolifération et la différentiation des kératinocytes. L'objet de ce travail fut de déterminer le rôle de PPARβ dans les processus d'adhésion et de migration des kératinocytes activés durant la régénération de l'épithélium blessé. Nous avons montré que les souris dépourvues du gène codant pour PPARβ ont de sévères imperfections affectant la morphologie de l'épithélium. Ce phénotype est corrélé à la modulation imparfaite du réseau d'active chez les souris dépourvues de PPARβ, à un défaut de localisation de l'intégrine α3 impliquée dans les complexes induisant la migration cellulaire, ainsi qu'à la modulation de l'expression d'acteurs majeurs affectant l'activité protéolytique de la matrice extra cellulaire. En conclusion, nos résultats montrent que PPARβ est impliqué dans le contrôle de la dynamique du cytosquelette d'active et la polarisation des kératinocytes activés. PPARβ étant impliqué dans l'acquisition d'un phénotype migratoire, il est légitime de se demander s'il intervient de même dans d'autres types cellulaires, par exemple dans la transition épithéliale-mésenchymateuse durant le développement, ou encore la progression de cellules tumorales. SUMMARY Highly coordinated intercellular interactions and single cell metabolism ensure cell and tissue maintenance of the skin. Healing of a skin wound involves keratinocyte activation by cytokines and growth factors. Activated keratinocytes acquire a motile phenotype that requires extracellular matrix remodeling and subsequent ligand activation through proteolytic activity, as well as cytoskeletal reorganisation induced by the release of cell-cell junctions and by the signalling relayed via integrin receptors and their cytoplasmic adaptors. PPARβ is a transcription factor activated by polyunsaturated fatty acids and fatty acid derivatives which belong to the nuclear hormone receptor superfamily. It is expressed in activated keratinocytes where it plays an essential role in protecting them from apoptosis. In addition, it plays an important function in hair follicle morphogenesis at the time of elongation, via the regulation of the balance between keratinocyte differentiation and proliferation. The aim of the present work was to determine if PPARβ is also involved in the regulation of migration and adhesion properties of keratinocytes during skin wound healing. We have shown that wounded PPARβ null mice display severe abnormalities of the keratinocyte migratory layer as shown at the histological level and using three-dimensional reconstruction. This altered migratory phenotype is correlated to altered dynamic of the actin cytoskeleton network, impaired α3 integrin localisation in migrating keratinocytes and changes in the expression of a key actor involved in extracellular matrix proteolytic activity. These results show that PPARβ is implicated in the fine tuning of the actin network organisation and the polarisation of activated keratinocytes following an epithelial wound. Whether these mechanisms are also controlled by PPARβ in other cell types during epithelial mesenchymal transition or tumour cell progression is an interesting question to rise.

Neutralization of Macrophage Migration Inhibitory Factor (MIF) by Fully Human Antibodies Correlates with Their Specificity for the β-Sheet Structure of MIF.

The macrophage migration inhibitory factor (MIF) is a proinflammatory cytokine that recently emerged as an attractive therapeutic target for a variety of diseases. A diverse panel of fully human anti-MIF antibodies was generated by selection from a phage display library and extensively analyzed in vitro. Epitope mapping studies identified antibodies specific for linear as well as structural epitopes. Experimental animal studies revealed that only those antibodies binding epitopes within amino acids 50-68 or 86-102 of the MIF molecule exerted protective effects in models of sepsis or contact hypersensitivity. Within the MIF protein, these two binding regions form a β-sheet structure that includes the MIF oxidoreductase motif. We therefore conclude that this β-sheet structure is a crucial region for MIF activity and a promising target for anti-MIF antibody therapy.

Zoledronate inhibits endothelial cell adhesion, migration and survival through the suppression of multiple, prenylation-dependent signaling pathways.

BACKGROUND: Recent evidence indicates that zoledronate, a nitrogen-containing bisphosphonate used to treat conditions of increased bone resorption, may have anti-angiogenic activity. The endothelial cells signaling events modulated by zoledronate remain largely elusive. OBJECTIVES: The aim of this work was to identify signaling events suppressed by zoledronate in endothelial cells and responsible for some of its biological effects. METHODS: Human umbilical vein endothelial cells (HUVEC) were exposed to zoledronate, isoprenoid analogs (i.e. farnesol and geranylgeraniol) and various inhibitors of signaling, and the effect on adhesion, survival, migration, actin cytoskeleton and signaling events characterized. RESULTS: Zoledronate reduced Ras prenylation, Ras and RhoA translocation to the membrane, and sustained ERK1/2 phosphorylation and tumor necrosis factor (TNF) induced JNK phosphorylation. Isoprenoid analogs attenuated zoledronate effects on HUVEC adhesion, actin stress fibers and focal adhesions, migration and survival. Isoprenoid analogs also restored Ras prenylation, RhoA translocation to the membrane, sustained FAK and ERK1/2 phosphorylation and prevented suppression of protein kinase B (PKB) and JNK phosphorylation in HUVEC exposed to TNF in the presence of zoledronate. Pharmacological inhibition of Rock, a RhoA target mediating actin fiber formation, phosphatidylinositol 3-kinase, an activator of PKB, MEK1/2, an activator of ERK1/2, and JNK, recapitulated individual zoledronate effects, consistent with the involvement of these molecules and pathways and their inhibition in the zoledronate effects. CONCLUSIONS: This work has demonstrated that zoledronate inhibits HUVEC adhesion, survival, migration and actin stress fiber formation by interfering with protein prenylation and has identified ERK1/2, JNK, Rock, FAK and PKB as kinases affected by zoledronate in a prenylation-dependent manner.

The impact of personality characteristics on the clinical expression in neurodegenerative disorders--a review.

Clinical experience suggests that longstanding personality characteristics as a person's most distinctive features of all are likely to play a role in how someone with dementia copes with his increasing deficiencies. Personality characteristics may have a pathoplastic effect on both behavioral and psychological symptoms (BPS) or on cognition as well as cognitive decline. Cognitive disorders accompanied by BPS are a tremendous burden for both the patient and their proxies. This review suggests that premorbid personality characteristics are co-determinants of BPS in cognitive disorders, but much effort is needed to clarify whether or not specific premorbid personality traits are associated with specific BPS as no strong links have so far emerged. This review further shows that a growing field of research is interested in the links not only between quite short-lived emotional states and cognitive processes, but also between longstanding personality traits and cognition in both healthy individuals and patients with neurodegenerative disorders. Furthermore, a few studies found that specific premorbid personality traits may be risk factors for neurodegenerative diseases. However, research findings in this area remain scarce despite a huge literature on personality and cognitive disorders in general. An important shortcoming that hampers so far the progress of our understanding in these domains is the confusion in the literature between longstanding premorbid personality traits and transient personality changes observed in neurodegenerative diseases. Few studies have based their assessments on accepted personality theories and carefully investigated premorbid personality traits in patients with cognitive disorders, although assessing personality may be complicated in these patients. Studying the impact of personality characteristics in cognitive disorders is an especially promising field of research in particular when concomitantly using neurobiological approaches, in particular structural brain imaging and genetic studies as suggested by as yet rare studies. Improved understanding of premorbid personality characteristics as determinants of both BPS or cognitive capacities or decline is likely to influence our attitudes towards the treatment of demented patients and ultimately to help in alleviating a patient's and their proxies' burden.

Primary cutaneous posttransplant lymphoproliferative disorders in solid organ transplant recipients: a multicenter European case series.

Primary cutaneous posttransplant lymphoproliferative disorders (PTLD) are rare. This retrospective, multicenter study of 35 cases aimed to better describe this entity. Cases were (re)-classified according to the WHO-EORTC or the WHO 2008 classifications of lymphomas. Median interval between first transplantation and diagnosis was 85 months. Fifty-seven percent of patients had a kidney transplant. Twenty-four cases (68.6%) were classified as primary cutaneous T cell lymphoma (CTCL) and 11 (31.4%) as primary cutaneous B cell PTLD. Mycosis fungoides (MF) was the most common (50%) CTCL subtype. Ten (90.9%) cutaneous B cell PTLD cases were classified as EBV-associated B cell lymphoproliferations (including one plasmablastic lymphoma and one lymphomatoid granulomatosis) and one as diffuse large B cell lymphoma, other, that was EBV-negative. Sixteen (45.7%) patients died after a median follow-up of 19.5 months (11 [68.8%] with CTCL [6 of whom had CD30(+) lymphoproliferative disorders (LPD)] and 5 [31.2%] with cutaneous B cell PTLD. Median survival times for all patients, CTCL and cutaneous B cell PTLD subgroups were 93, 93, and 112 months, respectively. Survival rates for MF were higher than those for CD30(+) LPD. The spectrum of primary CTCL in organ transplant recipients (OTR) is similar to that in the general population. The prognosis of posttransplant primary cutaneous CD30(+) LPD is worse than posttransplant MF and than its counterpart in the immunocompetent population. EBV-associated cutaneous B cell LPD predominates in OTR.

Differential effects of glutamate transporter inhibitors on the global electrophysiological response of astrocytes to neuronal stimulation

Astrocytes are responsible for regulating extracellular levels of glutamate and potassium during neuronal activity. Glutamate clearance is handled by glutamate transporter subtypes glutamate transporter 1 and glutamate-aspartate transporter in astrocytes. DL-threo-beta-benzyloxyaspartate (TBOA) and dihydrokainate (DHK) are extensively used as inhibitors of glial glutamate transport activity. Using whole-cell recordings, we characterized the effects of both transporter inhibitors on afferent-evoked astrocyte currents in acute cortical slices of 3-week-old rats. When neuronal afferents were stimulated, passive astrocytes responded by a rapid inward current followed by a persistent tail current. The first current corresponded to a glutamate transporter current. This current was inhibited by both inhibitors and by tetrodotoxin. The tail current is an inward potassium current as it was blocked by barium. Besides inhibiting transporter currents, TBOA strongly enhanced the tail current. This effect was barium-sensitive and might be due to a rise in extracellular potassium level and increased glial potassium uptake. Unlike TBOA, DHK did not enhance the tail current but rather inhibited it. This result suggests that, in addition to inhibiting glutamate transport, DHK prevents astrocyte potassium uptake, possibly by blockade of inward-rectifier channels. This study revealed that, in brain slices, glutamate transporter inhibitors exert complex effects that cannot be attributed solely to glutamate transport inhibition.