Mapping the modification of histones by the myeloperoxidase-derived oxidant hypochlorous acid (HOCl).

Histones are critical for the packaging of nuclear DNA and chromatin assembly, which is facilitated by the high abundance of Lys and Arg residues within these proteins. These residues are also the site of a range of post-translational modifications, which influence the regulatory function of histones. Histones are also present in the extracellular environment, following release by various pathways, particularly neutrophil extracellular traps (NETs). NETs contain myeloperoxidase, which retains its enzymatic activity and produces hypochlorous acid (HOCl). This suggests that histones could be targets for HOCl under conditions where aberrant NET release is prevalent, such as chronic inflammation. In this study, we examine the reactivity of HOCl with a mixture of linker (H1) and core (H2A, H2B, H3 and H4) histones. HOCl modified the histones in a dose- and time-dependent manner, resulting in structural changes to the proteins and the formation of a range of post-translational modification products. N-Chloramines are major products following exposure of the histones to HOCl and decompose over 24 h forming Lys nitriles and carbonyls (aminoadipic semialdehydes). Chlorination and dichlorination of Tyr, but not Trp residues, is also observed. Met sulfoxide and Met sulfones are formed, though these oxidation products are also detected albeit at a lower extent, in the non-treated histones. Evidence for histone fragmentation and aggregation was also obtained. These results could have implications for the development of chronic inflammatory diseases, given the key role of Lys residues in regulating histone function.

Quantifying parasite presence in relation to biological parameters of harbour porpoises Phocoena phocoena stranded on the Dutch coast.

Harbour porpoises are often found to be infected by endoparasites in several organs including the lungs and stomach as well as the heart, liver and ears. Nevertheless there is still little knowledge about the impact, ecology, transmission, and virulence of these parasitic infections. Here, we profile the presence of parasites in 4 frequently infected organs (lungs, stomach, liver and ears) in relation to biological parameters of harbour porpoises stranded along the Dutch coastline between December 2008 and December 2013. We found that parasites were common, with prevalence of 68% in lungs, 74.4% in ears, 26% in stomach and 23.5% in liver. We used generalised linear models to further quantify parasite presence in relation to biological data gathered during necropsy (sex, body length and nutritive condition). Body length (used as a proxy for age) was significant in explaining parasite presence for all organs with increasing probability of having the parasite with increasing body length. For the parasitic infections in the ears and stomach the nutritive condition was an additional significant factor, with a higher probability of parasite presence in porpoises in a poorer nutritive condition. The results of this study can be used as a baseline for assessing parasite presence in harbour porpoises and are a first step towards linking parasite infections to basic biological data gathered during necropsy.

Recurrent KIF2A mutations are responsible for classic lissencephaly.

Kinesins play a critical role in the organization and dynamics of the microtubule cytoskeleton, making them central players in neuronal proliferation, neuronal migration, and postmigrational development. Recently, KIF2A mutations were identified in cortical malformation syndromes associated with microcephaly. Here, we detected two de novo p.Ser317Asn and p.His321Pro mutations in KIF2A in two patients with lissencephaly and microcephaly. In parallel, we re-evaluated the two previously reported cases showing de novo mutations of the same residues. The identification of mutations only in the residues Ser317 and His321 suggests these are hotspots for de novo mutations. Both mutations lead to a classic form of lissencephaly, with a posterior to anterior gradient, almost indistinguishable from LIS1-related lissencephaly. However, three fourths of patients also showed variable congenital and postnatal microcephaly, up to -5 SD. Located in the motor domain of the KIF2A protein, the Ser317 and His321 alterations are expected to disrupt binding or hydrolysis of ATP and consequently the MT depolymerizing activity. This report also establishes that KIF2A mutations represent significant causes of classic lissencephaly with microcephaly.

[Ophthalmological imaging with ultrahigh field magnetic resonance tomography: technical innovations and frontier applications]. / Ophthalmologische Bildgebung mit Ultrahochfeld-Magnetresonanztomografie: technische Innovationen und wegweisende Anwendungen.

This review documents technical progress in ophthalmic magnetic resonance imaging (MRI) at ultrahigh fields (UHF, B(0) ≥ 7.0 T). The review surveys frontier applications of UHF-MRI tailored for high spatial resolution in vivo imaging of the eye, orbit and optic nerve. Early examples of clinical ophthalmic UHF-MRI including the assessment of melanoma of the choroid membrane and the characterisation of intraocular masses are demonstrated. A concluding section ventures a glance beyond the horizon and explores research promises along with future directions of ophthalmic UHF-MRI.

[Management of patients with conversion disorder]. / Beleid bij patiënten met conversiestoornis.

The symptoms of conversion disorder are not due to conscious simulation. There should be no doubt that the symptoms of conversion disorder are genuine, even if scans do not reveal any abnormalities. The management of patients with conversion disorder starts with an explanation of the diagnosis. The essence of this explanation is that patients first hear about what the diagnosis actually means and only after this about what they do not have. When explaining the diagnosis it is a good idea to use metaphors. The treatment of patients with conversion disorder is carried out together with a physical therapist. The collaboration of healthcare professionals who are involved in the treatment of a patient with conversion disorder should preferably be coordinated by the patient's general practitioner.

Rapid emergence of a virulent PB2 E627K variant during adaptation of highly pathogenic avian influenza H7N7 virus to mice.

BACKGROUND: Highly pathogenic avian influenza (HPAI) viruses pose a potential human health threat as they can be transmitted directly from infected poultry to humans. During a large outbreak of HPAI H7N7 virus among poultry in The Netherlands in 2003, bird to human transmission was confirmed in 89 cases, of which one had a fatal outcome. METHODS: To identify genetic determinants of virulence in a mammalian host, we passaged an avian H7N7/03 outbreak isolate in mouse lungs and evaluated the phenotype of the mouse-adapted variant in animal models and in vitro. RESULTS: Three passages in mouse lungs were sufficient to select a variant that was highly virulent in mice. The virus had a MLD50 that was >4.3 logs lower than that of its non-lethal parental virus. Sequence analysis revealed a single mutation at position 627 in PB2, where the glutamic acid was changed to a lysine (E627K). The mouse-adapted virus has this mutation in common with the fatal human case isolate. The virus remained highly pathogenic for chickens after its passage in mice. In ferrets, the mouse-adapted virus induced more severe disease, replicated to higher titers in the lower respiratory tract and spread more efficiently to systemic organs compared with the parental virus. In vitro, the PB2 E627K mutation had a promoting effect on virus propagation in mammalian, but not in avian cells. CONCLUSIONS: Our results show that the E627K mutation in PB2 alone can be sufficient to convert an HPAI H7N7 virus of low virulence to a variant causing severe disease in mice and ferrets. The rapid emergence of the PB2 E627K mutant during mouse adaptation and its pathogenicity in ferrets emphasize the potential risk of HPAI H7N7 viruses for human health.

Fatality following a suicidal overdose with varenicline.

The smoking cessation agent varenicline acts as a partial agonist on α(4)ß(2) nicotinic acetylcholine receptors. Although debated, several reports have linked varenicline therapy to an increased risk of suicidal thoughts and/or suicide. In addition, several non-fatal overdose cases have been reported. In this report, we utilised a sample preparation procedure suitable for postmortem samples and gas chromatography coupled to mass spectrometry to analyse samples obtained from a suicidal case in which ingestion of an overdose of varenicline had occurred. Extremely high concentrations of varenicline (>250 ng/ml) were detected in the blood of the deceased, in addition to high concentrations in urine and vitreous humour. To the best of our knowledge, similar high concentrations have not been reported yet. Although, with respect to the mechanism of death in this case, confounding factors were concomitant ethanol consumption and, importantly, potentially fatal hypothermia, this is the first report of a fatality associated with the ingestion of an overdose of varenicline.

[Conversion disorder]. / Conversiestoornis.

As described in the DSM-IV-TR, conversion disorder encompasses neurological symptoms not due to a recognised neurological disease. Some authors have suggested abandoning the label 'conversion disorder' and replacing it with the phrase 'functional neurological symptoms'. Two requirements for the diagnosis, namely, the association of psychological factors and the exclusion of feigning, produce several problems and should therefore not be included in the new criteria. Based on studies of the functional anatomy of perception and movement, it is likely that functional neurological symptoms are interpreted by patients as being involuntary and occurring spontaneously. In the current diagnostic criteria, the emphasis is on the exclusion of other disorders; clinical features that support the diagnosis have been proposed for the new criteria. Psychiatrists should be consulted if depression or anxiety disorders are suspected. If recovery comes to a standstill, such patients should be referred to psychologists who are experienced in cognitive behavioural therapy for patients with functional neurological symptoms.

Protective efficacy of Newcastle disease virus expressing soluble trimeric hemagglutinin against highly pathogenic H5N1 influenza in chickens and mice.

BACKGROUND: Highly pathogenic avian influenza virus (HPAIV) causes a highly contagious often fatal disease in poultry, resulting in significant economic losses in the poultry industry. HPAIV H5N1 also poses a major public health threat as it can be transmitted directly from infected poultry to humans. One effective way to combat avian influenza with pandemic potential is through the vaccination of poultry. Several live vaccines based on attenuated Newcastle disease virus (NDV) that express influenza hemagglutinin (HA) have been developed to protect chickens or mammalian species against HPAIV. However, the zoonotic potential of NDV raises safety concerns regarding the use of live NDV recombinants, as the incorporation of a heterologous attachment protein may result in the generation of NDV with altered tropism and/or pathogenicity. METHODOLOGY/PRINCIPAL FINDINGS: In the present study we generated recombinant NDVs expressing either full length, membrane-anchored HA of the H5 subtype (NDV-H5) or a soluble trimeric form thereof (NDV-sH5(3)). A single intramuscular immunization with NDV-sH5(3) or NDV-H5 fully protected chickens against disease after a lethal challenge with H5N1 and reduced levels of virus shedding in tracheal and cloacal swabs. NDV-sH5(3) was less protective than NDV-H5 (50% vs 80% protection) when administered via the respiratory tract. The NDV-sH5(3) was ineffective in mice, regardless of whether administered oculonasally or intramuscularly. In this species, NDV-H5 induced protective immunity against HPAIV H5N1, but only after oculonasal administration, despite the poor H5-specific serum antibody response it elicited. CONCLUSIONS/SIGNIFICANCE: Although NDV expressing membrane anchored H5 in general provided better protection than its counterpart expressing soluble H5, chickens could be fully protected against a lethal challenge with H5N1 by using the latter NDV vector. This study thus provides proof of concept for the use of recombinant vector vaccines expressing a soluble form of a heterologous viral membrane protein. Such vectors may be advantageous as they preclude the incorporation of heterologous membrane proteins into the viral vector particles.

Mutations in ISPD cause Walker-Warburg syndrome and defective glycosylation of α-dystroglycan.

Walker-Warburg syndrome (WWS) is an autosomal recessive multisystem disorder characterized by complex eye and brain abnormalities with congenital muscular dystrophy (CMD) and aberrant a-dystroglycan glycosylation. Here we report mutations in the ISPD gene (encoding isoprenoid synthase domain containing) as the second most common cause of WWS. Bacterial IspD is a nucleotidyl transferase belonging to a large glycosyltransferase family, but the role of the orthologous protein in chordates is obscure to date, as this phylum does not have the corresponding non-mevalonate isoprenoid biosynthesis pathway. Knockdown of ispd in zebrafish recapitulates the human WWS phenotype with hydrocephalus, reduced eye size, muscle degeneration and hypoglycosylated a-dystroglycan. These results implicate ISPD in a-dystroglycan glycosylation in maintaining sarcolemma integrity in vertebrates.

Mutations in SWI/SNF chromatin remodeling complex gene ARID1B cause Coffin-Siris syndrome.

We identified de novo truncating mutations in ARID1B in three individuals with Coffin-Siris syndrome (CSS) by exome sequencing. Array-based copy-number variation (CNV) analysis in 2,000 individuals with intellectual disability revealed deletions encompassing ARID1B in 3 subjects with phenotypes partially overlapping that of CSS. Taken together with published data, these results indicate that haploinsufficiency of the ARID1B gene, which encodes an epigenetic modifier of chromatin structure, is an important cause of CSS and is potentially a common cause of intellectual disability and speech impairment.

Presence of ATM protein and residual kinase activity correlates with the phenotype in ataxia-telangiectasia: a genotype-phenotype study.

Ataxia-telangiectasia (A-T) is an autosomal recessive neurodegenerative disorder with multisystem involvement and cancer predisposition, caused by mutations in the A-T mutated (ATM) gene. To study genotype-phenotype correlations, we evaluated the clinical and laboratory data of 51 genetically proven A-T patients, and additionally measured ATM protein expression and kinase activity. Patients without ATM kinase activity showed the classical phenotype. The presence of ATM protein, correlated with slightly better immunological function. Residual kinase activity correlated with a milder and essentially different neurological phenotype, absence of telangiectasia, normal endocrine and pulmonary function, normal immunoglobulins, significantly lower X-ray hypersensitivity in lymphocytes, and extended lifespan. In these patients, cancer occurred later in life and generally consisted of solid instead of lymphoid malignancies. The genotypes of severely affected patients generally included truncating mutations resulting in total absence of ATM kinase activity, while patients with milder phenotypes harbored at least one missense or splice site mutation resulting in expression of ATM with some kinase activity. Overall, the phenotypic manifestations in A-T show a continuous spectrum from severe classical childhood-onset A-T to a relatively mild adult-onset disorder, depending on the presence of ATM protein and kinase activity. Each patient is left with a tremendously increased cancer risk.

Over-expression of Grhl2 causes spina bifida in the Axial defects mutant mouse.

Cranial neural tube defects (NTDs) occur in mice carrying mutant alleles of many different genes, whereas isolated spinal NTDs (spina bifida) occur in fewer models, despite being common human birth defects. Spina bifida occurs at high frequency in the Axial defects (Axd) mouse mutant but the causative gene is not known. In the current study, the Axd mutation was mapped by linkage analysis. Within the critical genomic region, sequencing did not reveal a coding mutation whereas expression analysis demonstrated significant up-regulation of grainyhead-like 2 (Grhl2) in Axd mutant embryos. Expression of other candidate genes did not differ between genotypes. In order to test the hypothesis that over-expression of Grhl2 causes Axd NTDs, we performed a genetic cross to reduce Grhl2 function in Axd heterozygotes. Grhl2 loss of function mutant mice were generated and displayed both cranial and spinal NTDs. Compound heterozygotes carrying both loss (Grhl2 null) and putative gain of function (Axd) alleles exhibited normalization of spinal neural tube closure compared with Axd/+ littermates, which exhibit delayed closure. Grhl2 is expressed in the surface ectoderm and hindgut endoderm in the spinal region, overlapping with grainyhead-like 3 (Grhl3). Axd mutants display delayed eyelid closure, as reported in Grhl3 null embryos. Moreover, Axd mutant embryos exhibited increased ventral curvature of the spinal region and reduced proliferation in the hindgut, reminiscent of curly tail embryos, which carry a hypomorphic allele of Grhl3. Overall, our data suggest that defects in Axd mutant embryos result from over-expression of Grhl2.

Evaluation of the agonal stress: can immunohistochemical detection of ubiquitin in the locus coeruleus be useful?

The determination of the survival time after a crime as well as the concomitant physical and mental load of the victim is an important task for the forensic pathologist. The heat shock protein, ubiquitin, exerts an essential role in the cellular response to stress. We aimed to investigate the usefulness of the ubiquitin expression in the locus coeruleus as a marker for the evaluation of agonal stress. Is the amount of ubiquitin in this brain locus an indication of the length and/or intensity of the agonal period following various causes of death? The immunohistochemical (IHC) expression of ubiquitin is examined in formalin-fixed, paraffin-embedded slides of the human locus coeruleus (n = 48). The evaluation of the IHC staining is blindly performed, prior to the study of the medico-legal files. According to the length of agony, a division into subgroups is made. Three possible IHC staining patterns are observed: a staining of the neuronal nucleus or the cytoplasm or both. In addition, the number of neurons with ubiquitin expression per µm(2) is calculated in each locus coeruleus. Significant differences in the number of ubiquitin-immunoreactive neurons are noticed with respect to the length of the agony: A higher density of positive neurons is seen in case of a pronounced and extended death struggle.

Long term outcome of benign childhood epilepsy with centrotemporal spikes: Dutch Study of Epilepsy in Childhood.

PURPOSE: To determine long-term outcome in a cohort of children with newly diagnosed benign childhood epilepsy with centrotemporal spikes (BECTS). METHODS: 29 children with BECTS were included in the Dutch Study of Epilepsy in Childhood. Each child was followed for 5 years, and subsequently contacted 12-17 years after enrolment to complete a structured questionnaire. Twenty children had typical BECTS, nine had atypical BECTS (age at onset <4 years, developmental delay or learning difficulties at inclusion, other seizure types, atypical EEG abnormalities). RESULTS: Mean age at onset of epilepsy was 8.0 years with slight male preponderance. Most common seizure-types before enrolment were generalized tonic-clonic seizures (GTCS) and simple partial seizures; in 86% of the children seizures occurred during sleep. After 12-17 years, 96% had a terminal remission (TR(F)) of more than 5 years and 89% of more than 10 years. Mean duration of epilepsy was 2.7 years; mean age at reaching TR(F) was 10.6 years. Many children (63%) had experienced one or more (secondary) GTCS. Antiepileptic drugs were used by 79% of the children with a mean duration of 3.0 years. None of the children seemed to have developed learning problems or an arrest of cognitive development during follow-up. No significant differences were observed in patient characteristics or outcome between children with typical BECTS and children with atypical BECTS. CONCLUSIONS: All children in our cohort, both those with typical and atypical BECTS, had a very good prognosis with high remission rates after 12-17 years. None of the predictive factors for disease course and outcome observed in earlier studies (other seizure types, age at onset, multiple seizures at onset) were prognostic in our cohort.

A single immunization with soluble recombinant trimeric hemagglutinin protects chickens against highly pathogenic avian influenza virus H5N1.

BACKGROUND: The highly pathogenic avian influenza (HPAI) virus H5N1 causes multi-organ disease and death in poultry, resulting in significant economic losses in the poultry industry. In addition, it poses a major public health threat as it can be transmitted directly from infected poultry to humans with very high (60%) mortality rate. Effective vaccination against HPAI H5N1 would protect commercial poultry and would thus provide an important control measure by reducing the likelihood of bird-to-bird and bird-to-human transmission. METHODOLOGY/PRINCIPAL FINDINGS: In the present study we evaluated the vaccine potential of recombinant soluble trimeric subtype 5 hemagglutinin (sH5(3)) produced in mammalian cells. The secreted, purified sH5(3) was biologically active as demonstrated by its binding to ligands in a sialic acid-dependent manner. It was shown to protect chickens, in a dose-dependent manner, against a lethal challenge with H5N1 after a single vaccination. Protected animals did not shed challenge virus as determined by a quantitative RT-PCR on RNA isolated from trachea and cloaca swabs. Also in mice, vaccination with sH5(3) provided complete protection against challenge with HPAI H5N1. CONCLUSIONS/SIGNIFICANCE: Our results demonstrate that sH5(3) constitutes an attractive vaccine antigen for protection of chickens and mammals against HPAI H5N1. As these recombinant soluble hemagglutinin preparations can be produced with high yields and with relatively short lead time, they enable a rapid response to circulating and potentially pandemic influenza viruses.

Post-mortem (re)distribution of 3,4-methylenedioxymethamphetamine (MDMA, "ecstasy"): human and animal data.

In this paper, the distribution and redistribution of the amphetamine derivative, 3,4-methylenedioxymethamphetamine (MDMA, ecstasy) is brought into focus. Animal experimental data were compared with internationally reported MDMA-related human fatalities: in general, these turned out to be parallel with each other. Due to its inherent properties (e.g. significant volume of distribution), MDMA is liable to postmortem redistribution. Indeed, very high concentrations have been found in cardiac blood and tissues located centrally in the body (blood-rich organs such as lungs and liver in particular). This confirms that post-mortem redistribution due to diffusion from higher to lower concentration can easily take place, mainly at longer post-mortem intervals and when putrefaction occurs. Therefore, we can conclude that for post-mortem quantitation of amphetamine and derivatives, and MDMA in particular, peripheral blood sampling (e.g. femoral vein) remains compulsory. However, if the latter is impossible, MDMA quantification in a few alternative matrices such as vitreous humour and iliopsoas muscle may provide additional information to come to a reliable conclusion. Furthermore, it should be stressed that--at present--it is impossible to estimate the individual susceptibility to the various possible adverse effects of MDMA, which implies that it is impossible to provide a "safe" or "therapeutic" blood MDMA level. Therefore, in current forensic practice, the post-mortem pathological and toxicological findings should form an entity in order to draw a well-grounded conclusion.

Mice in ecstasy: advanced animal models in the study of MDMA.

The party drug 3,4-methylenedioxymethamphetamine -better known as MDMA or ecstasy- has numerous effects on the human body, characterized by a rush of energy, euphoria and empathy. However, also a multitude of toxic/neurotoxic effects have been ascribed to MDMA, based upon case reports and studies in animals. Given the intrinsic difficulties associated with controlled studies in human beings, most of our insights into the biology of MDMA have been gained through animal studies. The vast majority of these studies utilizes a pharmacological approach to elucidate the mechanisms by which MDMA exerts its effects. Advances in genetics during the last decade have led to the development of several mouse models (transgenic or knockout) that have greatly contributed to our understanding of MDMA biology. This review provides an overview of these genetically modified animal models, in the light of some characteristic effects of MDMA, e.g. hyperlocomotion, neurotoxicity, hyperthermia, behaviour or rewarding. Without a shadow of a doubt, the next decade will bring many more advanced animal models, such as mice with site-specific deletion or rescue of genes and more genetically modified rat models. These models will further improve our knowledge on the pharmacology and toxicity of MDMA and, possibly, may assist in developing therapies coping with potential damage in abusers of MDMA and other drugs, as well as in patients suffering from specific neuronal pathologies.