A comparison of oxidative stress in smokers and non-smokers: an <Emphasis Type="Italic">in vivo</Emphasis> human quantitative study of <Emphasis Type="Italic">n</Emphasis>-3 lipid peroxidation

Background

Cigarette smoking is believed to cause oxidative stress by several mechanisms, including direct damage by radical species and the inflammatory response induced by smoking, and would therefore be expected to cause increased lipid peroxidation. The aim was to carry out the first study of the relationship of smoking in humans to the level of n-3 lipid peroxidation indexed by the level of ethane in exhaled breath.

Methods

Samples of alveolar air were obtained from 11 smokers and 18 non-smokers. The air samples were analyzed for ethane using mass spectrometry.

Results

The two groups of subjects were matched with respect to age and gender. The mean cumulative smoking status of the smokers was 11.8 (standard error 2.5) pack-years. The mean level of ethane in the alveolar breath of the group of smokers (2.53 (0.55) ppb) was not significantly different from that of the group of non-smokers (2.59 (0.29) ppb; p = 0.92). With all 29 subjects included, the Spearman rank correlation coefficient between ethane levels and cumulative smoking status was -0.11 (p = 0.58), while an analysis including only the smokers yielded a corresponding correlation coefficient of 0.11 (p = 0.75).

Conclusion

Our results show no evidence that cigarette smoking is related to increased n-3 lipid peroxidation as measured by expired ethane.

     

Mutation analysis of the Ras pathway genes<Emphasis Type="Italic"> NRAS</Emphasis>,<Emphasis Type="Italic"> HRAS</Emphasis>,<Emphasis Type="Italic"> KRAS</Emphasis> and<Emphasis Type="Italic"> BRAF</Emphasis> in glioblastomas

Aberrant activation of Ras signaling is a common finding in human glioblastomas. To determine the contribution of Ras gene mutations to this aberration, we screened 94 glioblastomas for mutations in the three Ras family genes NRAS, KRAS and HRAS. All tumors were additionally analyzed for mutations in BRAF, which encodes a Ras-regulated serine/threonine kinase with oncogenic properties. Mutation analysis of the entire coding regions of NRAS and KRAS, as well as the known mutation hot-spot sites in HRAS, identified somatic point mutations in two glioblastomas, both affecting codon 12 of NRAS (c.35G>A, p.G12D). Three additional tumors carried BRAF mutations altering the known hot-spot codon 599 (c.1796T>A, p.V599E). None of these five glioblastomas showed amplification of the EGFR or PDGFRA genes, while three of the tumors, including two with NRAS and one with BRAF mutation, demonstrated PTEN missense mutations or loss of PTEN mRNA expression. Taken together, our data suggest activating mutations in NRAS or BRAF as a molecular alteration that contributes to aberrant Ras signaling in a small fraction of glioblastomas.     

<Emphasis Type="Italic">c</Emphasis><Emphasis Type="Italic">-MYC</Emphasis> amplification and expression in astrocytic tumors

Point mutations and genomic multiplications in the α-synuclein (αSYN) gene cause autosomal-dominant Parkinson’s disease. Moreover, αSYN fibrils are the major component of Lewy bodies, the neuropathological hallmarks of Parkinson’s disease and dementia with Lewy bodies as well as of glial cytoplasmic inclusions in multiple system atrophy. These diseases are collectively referred to as α-synucleinopathies. Cellular mechanisms regulating αSYN fibril formation and toxicity are intensely studied in vitro, and in cell culture and diverse animal models. Specific neuropathology was achieved in transgenic mouse models using several promoters to express human wild-type and mutant αSYN in brain regions affected by the various α-synucleinopathies. Somatodendritic accumulation of the transgenic αSYN with neuritic distortions was a common finding. The nigrostriatal dopaminergic projections were surprisingly resistant to α-synucleinopathy in transgenic mice, although they tended to be more vulnerable to neurotoxins. In a few mouse models, αSYN aggregated in an age-dependent manner into genuine fibrillar amyloid. Brain region selective αSYN neuropathology correlated with specific behavioral impairments, such as locomotor dysfunction and cognitive decline. Thus, the αSYN fibrillization process is tightly linked to neuropathology. The role and thus therapeutic potential of post-translational modifications (ubiquitinylation, oxidation, phosphorylation, truncation) and modifier genes on αSYN neuropathology can now be assessed in valid transgenic mouse models of α-synucleinopathies.     

Sequence analysis of <Emphasis Type="Italic">Drd2</Emphasis>, <Emphasis Type="Italic">Drd4</Emphasis>, and <Emphasis Type="Italic">Dat1</Emphasis> in SHR and WKY rat strains

Background  

The Spontaneously Hypertensive Rat (SHR) shows a number of behaviours that closely parallel those seen in children with attention-deficit hyperactivity disorder. These include motor hyperactivity, excessive responses under a fixed-interval/extinction schedule, difficulty in acquiring operant tasks and increased sensitivity to immediate behavioural reinforcement. As in children with ADHD, the behavioural and cognitive deficits in the SHR are responsive to stimulants, including d-amphetamine and d,l-methylphenidate. The non-hyperactive Wistar Kyoto (WKY) rat strain is often used as a control in behavioural studies of the SHR, and WKY itself has been suggested to be a useful animal model of depression. Numerous studies have shown that dopaminergic neurotransmission is altered between the two strains. Human genetic studies have found associations between several dopaminergic genes and both ADHD and depression.     

Association study of <Emphasis Type="Italic">interleukin 2</Emphasis> (<Emphasis Type="Italic">IL2</Emphasis>) and <Emphasis Type="Italic">IL4</Emphasis> with schizophrenia in a Japanese population

Interleukin 2 (IL-2) and IL-4 are pleiotropic cytokines regulating Th1/Th2 balance and have a regulatory activity in brain function. Thus these cytokines have been implicated in the pathophysiology of schizophrenia. The latest studies provided controversial results regarding the genetic associations of these cytokines. The functional polymorphisms, IL2-330T/G and IL4-590C/T, were associated with schizophrenia in a German population, although contradictory findings were also reported in a Korean population. To ascertain whether IL2 and IL4 contribute to vulnerability to schizophrenia, we conducted a moderate-scale case-control (536 patients and 510 controls) association study for seven polymorphisms in Japanese subjects. There were no significant associations of these genes with schizophrenia using either single marker or haplotype analyses. The present study suggests that IL2 and IL4 do not contribute to vulnerability to schizophrenia in the Japanese population.     

A single nucleotide change in the mumps virus F gene affects virus fusogenicity <Emphasis Type="Italic">in vitro</Emphasis> and virulence <Emphasis Type="Italic">in vivo</Emphasis>

Mumps virus is highly neurotropic, with evidence of infection of the central nervous system in more than half of clinical cases. In the prevaccine era, mumps was a major cause of viral meningitis in most developed countries. Despite efforts to attenuate the virus, some mumps vaccines have retained virulence properties and have caused aseptic meningitis in vaccinees, resulting in public resistance to vaccination in some countries. Ensuring the safety of mumps vaccines is an important public health objective, as the need for robust immunization programs has been made clear by the recent resurgence of mumps outbreaks worldwide, including the United States, which in 2006 experienced its largest mumps outbreak in 20 years. To better understand the molecular basis of mumps virus attenuation, the authors developed two infectious full-length cDNA clones for a highly neurovirulent strain of mumps virus. The clones differed at only one site, possessing either an A or G at nucleotide position 271 in the F gene, to represent the heterogeneity identified in the original virulent clinical isolate. In comparison to the clinical isolate, virus rescued from the A-variant cDNA clone grew to higher cumulative titers in vitro but exhibited similar cytopathic effects in vitro and virulence in vivo. In contrast, virus rescued from the G-variant cDNA clone, in comparison to the clinical isolate and the A-variant, was more fusogenic in vitro but replicated to lower cumulative titers and was less neurovirulent in vivo. These data suggest that nucleotide position 271 in the F gene plays a significant role in virus pathogenesis. This infectious clone system will serve as a key tool for further examination of the molecular basis for mumps virus neurovirulence and neuroattenuation.     

Association of <Emphasis Type="Italic">CILP</Emphasis>, <Emphasis Type="Italic">COL9A2</Emphasis> and <Emphasis Type="Italic">MMP3</Emphasis> Gene Polymorphisms with Lumbar Disc Degeneration in an Indian Population

Lumbar disc degeneration (LDD) is a multifactorial disorder caused by genetic and environmental factors. Polymorphisms in several structural and inflammatory genes like collagens, aggrecan, matrix metalloproteinases are associated with the risk of disc degeneration. In this study, we analyzed the role of a few important single nucleotide polymorphisms in cartilage intermediate layer protein (CILP), collagen 9A2 (COL9A2) and matrix metalloproteinase 3 (MMP3) genes in LDD from an Indian population. Two hundred patients with LDD and 200 healthy controls were recruited for the study. Genotyping was performed by allelic discrimination assay. The rs2073711 polymorphism (CILP gene - GG genotype) was associated with reduced risk of LDD in the Indian population (OR?=?0.43, p?=?0.016). The rs591058 polymorphism (MMP3 gene - TT genotype) is found to be associated with lower risk among women (OR?=?0.34, p?=?0.041). No significant association was found between COL9A2 polymorphism rs7533552 and the risk of LDD. We conclude that the CILP gene polymorphism (rs2073711) is associated with a lower risk of LDD, the MMP3 (rs591058) gene polymorphism is associated with LDD among women, and the TT genotype confers a lower risk of LDD.     

<Emphasis Type="Italic">Clostridium septicum</Emphasis> Pneumocephalus

Background

Spontaneous pneumocephalus in the nontraumatic setting is distinctly unusual. Pneumocephalus from central nervous system infection with Clostridium septicum has been rarely reported, and more commonly reflects a later stage of abscess formation. We present an unusual case of invasive C. septicum infection without an associated diagnosed malignancy presenting with rapidly progressive CNS pathology and resultant early pneumocephalus.

Methods

Medical records, radiologic imaging, and microbiological specimens of a case were reviewed.

Results

A 66-year-old male presented with a history of two witnessed generalized tonic–clonic seizures on awakening. He was found unresponsive at the scene by paramedics and subsequently intubated. There was no reported antecedent symptomatology, such as headache, fever, chills, focal weakness, and speech or gait disturbances. Medical history was remarkable only for diet-controlled hypertension. Computed tomography (CT) head imaging revealed an abnormal right parietal hypodensity. The patient was evaluated per the acute stroke protocol but was not deemed a candidate for intervention or thrombolytic therapy given the uncertainty of his clinical presentation; intravenous antibiotics were administered for possible sepsis. Follow-up CT imaging of the head performed 8 h later revealed right parieto-temporal pneumocephalus with extensive cerebral edema and effacement of basilar cisterns. Neurosurgical intervention was not deemed appropriate given the catastrophic nature of his injury and the patient subsequently expired 14 h after presentation. Blood cultures grew gram-positive rods in three of four bottles identified as C. septicum.

Conclusions

Clostridium septicum is an uncommon and often fatal cause of nontraumatic pneumocephalus. This underscores the need for a high index of clinical suspicion in cases with unexplained pneumocephalus, as early diagnosis remains the key to survival. In survivors of C. septicum infection, subsequent colonoscopy should be considered to exclude undiagnosed or occult gastrointestinal malignancy.

     

Caspase-3 activation is required for reovirus-induced encephalitis <Emphasis Type="Italic">in vivo</Emphasis>

Reovirus infection of neonatal mice provides a classic experimental system for understanding the molecular pathogenesis of central nervous system (CNS) viral infection. CNS tissue injury, caused by many human neurotropic viruses, including herpes viruses and West Nile virus, is associated with caspase-dependent apoptotic neuronal cell death. We have previously shown that reovirus-induced CNS tissue injury results from apoptosis and is associated with activation of both death-receptor and mitochondrial apoptotic pathways culminating in the activation of the downstream effector caspase, caspase-3. In order to directly investigate the role of caspase-3 in virus-induced neuronal death and CNS tissue injury during encephalitis, we have compared the pathogenesis of reovirus CNS infection in mice lacking the caspase-3 gene (caspase-3 (−/−)) to syngeneic wild-type mice. Prior studies of antiapoptotic treatments for reovirus-infected mice have indicated that protection from reovirus-induced neuronal injury can occur without altering the viral titer in the brains of infected mice. We now show that reovirus infection of caspase-3 (−/−) mice was associated with dramatic reduction in severity of CNS tissue injury, decreased viral antigen and titer in the brain, and enhanced survival of infected mice. Following intracerebral inoculation, the authors also show that virus spread from the brain to the eyes in reovirus-infected caspase-3 (−/−) mice, indicating that viral spread was intact in these mice. Examination of brains of long-term survivors of reovirus infection among caspase-3 (−/−) mice showed that these mice eventually clear their CNS viral infection, and do not manifest residual or delayed CNS tissue injury.     

<Emphasis Type="Italic">CIC</Emphasis> and <Emphasis Type="Italic">FUBP1</Emphasis> mutations in oligodendrogliomas,oligoastrocytomas and astrocytomas

CIC and FUBP1 mutations have recently been detected in oligodendrogliomas but not in oligoastrocytomas. However, allelic losses in the regions on chromosomal arms 19q and 1p harboring CIC and FUBP1 are a common feature of both, oligodendrogliomas and oligoastrocytomas. To resolve this discrepancy, we analyzed CIC and FUBP1 mutations in a set of primary brain tumors including 18 oligodendrogliomas and 42 oligoastrocytomas. In addition, we analyzed 10 astrocytomas and 16 glioblastomas with allelic losses on 19q as well as a set of 12 medulloblastomas for CIC mutations. CIC mutations were found in 15/18 oligodendrogliomas, 14/42 oligoastrocytomas and 3/10 preselected astrocytomas. With the exception of a single case, all CIC mutations occurred in tumors with combined 1p/19q losses. In contrast to oligodendrogliomas where CIC mutations were always detected along with 1p/19q co-deletion, CIC mutations were only found in 52 % of the 1p/19q co-deleted oligoastrocytomas. FUBP1 mutations were detected in 7/61 tumors, all presenting with CIC mutations. FUBP1 mutations appear to cluster in the DNA binding domain spanning exons 5–14. CIC and FUBP1 mutations exclusively occurred in presence of either IDH1 or IDH2 mutations. Our data confirm CIC and FUBP1 mutations in oligodendrogliomas and demonstrate the presence of these mutations in oligoastrocytomas.     

Update Anti-<Emphasis Type="Italic">N</Emphasis>-Methyl-<Emphasis Type="Italic">D</Emphasis>-Aspartat-Rezeptor-Enzephalitis

Autoimmune encephalitis is a group of autoimmune inflammatory disorders affecting both grey and white matter of the central nervous system. Encephalitis with autoantibodies against the N?methyl-D-aspartate receptor (NMDA-R) is the most frequent autoimmune encephalitis syndrome presenting with a characteristic sequence of psychiatric and neurological symptoms. Treatment necessitates a close interdisciplinary cooperation. This article provides an update on the current knowledge on diagnostic standards, pathogenesis, and treatment strategies for anti-NMDA-R encephalitis from psychiatric and neurological perspectives.     

Twenty-three microsatellite loci for <Emphasis Type="Italic">Styrax confusus</Emphasis> and <Emphasis Type="Italic">Styrax japonicus</Emphasis> (Styracaceae)

Twelve microsatellite loci were isolated from an enriched genomic library of the rock scallop (Spondylus calcifer). One locus was monomorphic. Overall polymorphic loci, the mean numbers of alleles per locus at one locality was 9.6 (range 3–16), and the average observed and expected heterozygosities were 0.650 and 0.707, respectively. Three loci deviated from Hardy–Weinberg equilibrium, and from these, one locus had and excess of heterozygotes and the other two loci showed deficits of heterozygotes likely due to the presence of null alleles. No evidence of linkage disequilibrium was found among loci. These loci are the first microsatellites ever reported for the monotypic family Spondylidae, and will be useful to validate the predictions of oceanographic larval transport models and connectivity between patchy reefs within fishing areas and marine reserves in the northern Gulf of California, Mexico.     

<Emphasis Type="Italic">In vivo</Emphasis> neurochemical characterization of Anatoxin-a evoked dopamine release from striatum

Summary. Anatoxin-a (AnTx) is a natural neurotoxin, which acts as a potent and stereoselective agonist at the nicotinic acetylcholine receptors. The in vivo actions of the AnTx on dopamine (DA) release are scarcely characterized. The aim of this study was to determine the neurochemical bases for AnTx-induced striatal DA release, using the brain microdialysis technique, in freely moving rats. Local application of AnTx (3.5 mM) through the microdialysis probe produced an increase in striatal DA levels (701 ± 51% with respect to basal values). The effect of infusion of AnTx in Ca²⁺-free Ringer medium, in Na⁺-free Ringer medium and with TTX in the medium, was inhibited. Also, reserpine pre-treatment blocked the action of AnTx on striatal DA levels. To investigate the involvement of the DA transporter, the effects of AnTx were observed in the presence of nomifensine. The coadministration of AnTx and nomifensine evoked an additive effect on striatal DA levels. The latter results show that the DA release is not mediated by a decreased DA uptake. Taken as a whole, these results suggest that the effects of AnTx are predominantly mediated by an exocytotic mechanism, Ca²⁺-, Na⁺- and TTX-dependent, and not by a mechanism mediated by the DA transporter.     

<Emphasis Type="Italic">DAT1</Emphasis> and <Emphasis Type="Italic">DRD4</Emphasis> genes involved in key dimensions of adult ADHD

Attention-deficit hyperactivity disorder (ADHD) is a highly heritable neurodevelopmental disorder often persisting in adulthood. Genetic studies of ADHD mainly focused on the Dopamine Transporter (DAT1) and the Dopamine Receptor 4 (DRD4) genes. Nevertheless, polymorphisms of these genes explain only a small fraction of the assigned risk, suggesting that intermediate dimensions and environmental factors should also be considered. We investigated in 77 adult ADHD subjects compared to 474 controls, how polymorphisms within the genes coding for DAT1 (40-bp VNTR in 3′UTR), the Dopamine Receptor 2 (DRD2) (rs1799732) and DRD4 (48-bp VNTR in exon 3), may modulate the expression of the disorder. By genotyping DAT1, we detected a new 9.5R allele showing a deletion of 40 bp and also an insertion of 19 bp compared to the 10R allele. This novel allele was found to be significantly protective for ADHD (p < 0.0001). Another significant difference was found in the distribution of DRD4 48-bp VNTR 6R allele when comparing patients and controls (p = 0.0007). In addition significant results were also found for DAT1 9.5R allele, which was associated with impulsiveness (p = 1.98 × 10^?4) and trait anger scores (p = 7.66 × 10^?4). Moreover, impulsiveness scores were partly modulated by an interaction between the DRD4 48-bp VNTR 6R allele and childhood maltreatment (p = 0.01), however, this result did not resist correction for multiple comparisons. Altogether, our results show the putative involvement of DAT1 and DRD4 genes in the aetiology of ADHD with a main role in modulation of key dimensions of the disorder.     

The complete mitochondrial genomes of two globally invasive ants,the Argentine ant <Emphasis Type="Italic">Linepithema</Emphasis><Emphasis Type="Italic">humile</Emphasis> and the little fire ant <Emphasis Type="Italic">Wasmannia auropunctata</Emphasis>

Ants are among the most widespread and damaging of invasive alien species. Here, we report the complete mitochondrial genomes for two globally invasive ants: the Argentine ant Linepithema humile and the little fire ant Wasmannia auropunctata. The circular genomes of L. humile and W. auropunctata are 15,929 and 16,362 bp in length, respectively, and encode the same typical set of 37 mitochondrial genes (i.e. 13 PCGs, 22 tRNAs and two rRNAs) and one control region. The mitochondrial genome of W. auropunctata harbors a unique gene arrangement (‘rrnS-trnV-CR-trnM-trnI-trnQ-nad2-trnW-trnC-trnY’; the underlines indicate inverted genes) between rrnL and cox1. Phylogenetic analysis largely corroborated the traditional taxonomy, except for L. humile which was found to be more related to those taxa of the subfamilies Formicinae and Myrmicinae than to the consubfamilial Leptomyrmex pallens. Our genomic data can be readily used for genetic assays of these two globally invasive ants.