Power spectrum analysis of EEG in a translational nonhuman primate model after chronic exposure to low levels of the common marine neurotoxin, domoic acid.

Domoic acid (DA), the focus of this research, is a marine algal neurotoxin and epileptogen produced by species in the genus Pseudo-nitzschia. DA is found in finfish and shellfish across the globe. The current regulatory limit for DA consumption (20 ppm in shellfish) was set to protect humans from acute toxic effects, but there is a growing body of evidence suggesting that regular consumption of DA contaminated seafood at or below the regulatory limit may lead to subtle neurological effects in adults. The present research uses a translational nonhuman primate model to assess neurophysiological changes after chronic exposure to DA near the regulatory limit. Sedated electroencephalography (EEG) was used in 20 healthy adult female Macaca fascicularis, orally administered 0.075 and 0.15 mg DA/kg/day for at least 10 months. Paired video and EEG recordings were cleaned and a Fast Fourier Transformation was applied to EEG recordings to assess power differences in frequency bands from 1-20 Hz. When DA exposed animals were compared to controls, power was significantly decreased in the delta band (1-4 Hz, p < 0.005) and significantly increased in the alpha band (5-8 Hz, p < 0.005), theta band (9-12 Hz, p < 0.01), and beta band (13-20 Hz, p < 0.05). The power differences were not dose dependent or related to the duration of DA exposure, or subtle clinical symptoms of DA exposure (intentional tremors). Alterations of power in these bands have been associated with a host of clinical symptoms, such as deficits in memory and neurodegenerative diseases, and ultimately provide new insight into the subclinical toxicity of chronic, low-dose DA exposure on the adult primate brain.

Cerebellar Cognitive Affective Syndrome in Costa da Morte Ataxia (SCA36).

SCA36 is an autosomal dominant spinocerebellar ataxia (SCA) affecting many families from Costa da Morte, a northwestern region of Spain. It is caused by an intronic GGCCTG repeat expansion in NOP56. In order to characterize the cognitive and affective manifestations of this cerebellar disease, a group of 30 SCA36 mutation carriers (11 preataxic and 19 ataxic patients) were assessed with a comprehensive battery of standardized tests. Phonological verbal fluency - but not semantic fluency - was already mildly impaired in preataxic subjects. In ataxic patients, both phonological and semantic fluencies were significantly below normal. Depression, while more frequent and prominent in ataxic patients, was also often present in the preataxic stage. This is the first systematic study supporting the presence of a mild cerebellar cognitive and affective syndrome in SCA36. Routine evaluation of cognitive and emotional spheres in SCA36 patients as well as asymptomatic mutation carriers should allow early detection and timely therapeutic intervention.

La ataxia espinocerebelosa 36 (SCA36): «Ataxia da Costa da Morte» / Spinocerebellar ataxia 36 (SCA36): «Costa da Morte ataxia»

Introducción-objetivos: Describir la historia del descubrimiento de la SCA36 y revisar los conocimientos actuales sobre esta entidad que, por un efecto fundador, ha pasado a ser la SCA más prevalente en Galicia (España). Desarrollo: La SCA36 es una enfermedad heredodegenerativa autosómica dominante, de inicio tardío y lenta progresión, que cursa con ataxia cerebelosa, hipoacusia neurosensorial y discreta afectación de neuronas motoras (atrofia y fasciculaciones linguales y signos piramidales leves). Ha sido descrita inicialmente en Japón (ataxia del río Asida) y en Galicia (ataxia da Costa da Morte). Se produce por una mutación (expansión intrónica de hexanucleótido) en el gen NOP56, localizado en 20p13. En los estudios de resonancia magnética se observa inicialmente atrofia vermiana superior, que se extenderá al resto del cerebelo y finalmente a la porción bulboprotuberancial del tronco cerebral, sin lesiones de sustancia blanca. Las velocidades de conducción nerviosa periférica son normales y en los estudios de potenciales evocados somatosensoriales se detecta retraso de la conducción al estimular en miembros inferiores. En los pacientes con hipoacusia, suele encontrarse en la audiometría una caída > 40dB a partir de 2.400Hz; también se observa ausencia de ondas I y II en los estudios de potenciales evocados auditivos. Conclusiones: La ataxia da Costa da Morte-SCA36 es la SCA más prevalente en Galicia (España). Dada la alta tasa de emigración de nuestra comunidad autónoma, se espera que se diagnostiquen nuevos casos en diversas latitudes, sobre todo en América Latina. Ahora está disponible el diagnóstico genético para pacientes con clínica y portadores asintomáticos. Dado el alto número de pacientes en riesgo de sufrir la enfermedad, continuamos con las investigaciones para aclarar los mecanismos moleculares patogénicos y poder encontrar una terapéutica (AU)

Introduction-objective: To describe the history of the discovery of SCA36 and review knowledge of this entity, which is currently the most prevalent hereditary ataxia in Galicia (Spain) owing to a founder effect. Development: SCA36 is an autosomal dominant hereditary ataxia with late onset and slow progression. It presents with cerebellar ataxia, sensorineural hearing loss, and discrete motor neuron impairment (tongue atrophy with denervation, discrete pyramidal signs). SCA36 was first described in Japan (Asida River ataxia) and in Galicia (Costa da Morte ataxia). The condition is caused by a genetic mutation (intronic hexanucleotide repeat expansion) in the NOP56 gene on the short arm of chromosome 20 (20p13). Magnetic resonance image study initially shows cerebellar vermian atrophy that subsequently extends to the rest of the cerebellum and finally to the pontomedullary region of the brainstem without producing white matter lesions. Peripheral nerve conduction velocities are normal, and sensorimotor evoked potential studies show delayed conduction of stimuli to lower limbs. In patients with hearing loss, audiometric studies show a drop of > 40dB in frequencies exceeding 2,500Hz. Auditory evoked potential studies may also show lack of waves I and II. Conclusions: Costa da Morte ataxia or SCA36 is the most prevalent SCA in the Spanish region of Galicia. Given the region's history of high rates of emigration, new cases may be diagnosed in numerous countries, especially in Latin America. Genetic studies are now available to patients and asymptomatic carriers. Since many people are at risk for this disease, we will continue our investigations aimed at elucidating the underlying pathogenic molecular mechanisms and discovering effective treatment (AU)

Evaluating the Calling Performance of a Rare Disease NGS Panel for Single Nucleotide and Copy Number Variants.

INTRODUCTION: Variant detection protocols for clinical next-generation sequencing (NGS) need application-specific optimization. Our aim was to analyze the performance of single nucleotide variant (SNV) and copy number (CNV) detection programs on an NGS panel for a rare disease. METHODS: Thirty genes were sequenced in 83 patients with hereditary spastic paraplegia. The variant calls obtained with LifeScope, GATK UnifiedGenotyper and GATK HaplotypeCaller were compared with Sanger sequencing. The calling efficiency was evaluated for 187 (56 unique) SNVs and indels. Five multiexon deletions detected by multiple ligation probe assay were assessed from the NGS panel data with ExomeDepth, panelcn.MOPS and CNVPanelizer software. RESULTS: There were 48/51 (94%) SNVs and 1/5 (20%) indels consistently detected by all the calling algorithms. Two SNVs were not detected by any of the callers because of a rare reference allele, and one SNV in a low coverage region was only detected by two algorithms. Regarding CNVs, ExomeDepth detected 5/5 multi-exon deletions, panelcn.MOPs 4/5 and only 3/5 deletions were accurately detected by CNVPanelizer. CONCLUSIONS: The calling efficiency of NGS algorithms for SNVs is influenced by variant type and coverage. NGS protocols need to account for the presence of rare variants in the reference sequence as well as for ambiguities in indel calling. CNV detection algorithms can be used to identify large deletions from NGS panel data for diagnostic applications; however, sensitivity depends on coverage, selection of the reference set and deletion size. We recommend the incorporation of several variant callers in the NGS pipeline to maximize variant detection efficiency.

Effect of resveratrol analogue, DMU-212, on antioxidant status and apoptosis-related genes in rat model of hepatocarcinogenesis.

The aim of the study was to examine whether antioxidant properties of 3,4,4',5-tetramethoxystilbene (DMU-212) contribute to its anticarcinogenic activity and whether DMU-212 affects the expression of apoptosis-related genes. Two-stage model of hepatocarcinogenesis was used; male Wistar rats were challenged with N-nitrosodiethylamine (NDEA), 200 mg/kg body weight (b.w.), intraperitoneal, then phenobarbital (PB) in drinking water (0.05%) was administered. Simultaneously, DMU-212 was given per os at a dose 20 or 50 mg/kg b.w. two times a week for 16 weeks. DMU-212 caused a moderate decrease in hepatic thiobarbituric acid reactive substances and protein carbonyls concentration elevated in rats treated with NDEA/PB. The activity of antioxidant enzymes examined reduced by NDEA/PB treatment was not restored in rats coadministered with DMU-212. Effects of DMU-212 on messenger RNA (mRNA) expression of antioxidant enzymes in rats challenged with NDEA/PB were diversified; no changes in their protein expression were noted in any of the groups. The expression of 17,000 genes was analyzed by Affymetrix® Rat Gene 1.1 ST Array; 15 apoptosis-related genes were selected and validated by RT-q PCR. The combined treatment with NDEA/PB and DMU-212 increased the mRNA level of some genes driving mitochondria-mediated apoptosis, whereas the mRNA expression of some anti-apoptotic genes triggering receptor-mediated apoptosis was reduced. The expression of genes encoding caspases-4, -8, -9, and -12 was also increased in rats treated with DMU-212. Although antioxidant effect of DMU-212 in rats challenged with NDEA/PB was moderate, its potential anticarcinogenic properties were demonstrated as evidenced by modulation of apoptosis-related genes.

Spinocerebellar ataxia 36 (SCA36): «Costa da Morte ataxia¼. / La ataxia espinocerebelosa 36 (SCA36): «Ataxia da Costa da Morte¼.

INTRODUCTION-OBJECTIVE: To describe the history of the discovery of SCA36 and review knowledge of this entity, which is currently the most prevalent hereditary ataxia in Galicia (Spain) owing to a founder effect. DEVELOPMENT: SCA36 is an autosomal dominant hereditary ataxia with late onset and slow progression. It presents with cerebellar ataxia, sensorineural hearing loss, and discrete motor neuron impairment (tongue atrophy with denervation, discrete pyramidal signs). SCA36 was first described in Japan (Asida River ataxia) and in Galicia(Costa da Morte ataxia). The condition is caused by a genetic mutation (intronic hexanucleotide repeat expansion) in the NOP56 gene on the short arm of chromosome 20 (20p13). Magnetic resonance image study initially shows cerebellar vermian atrophy that subsequently extends to the rest of the cerebellum and finally to the pontomedullary region of the brainstem without producing white matter lesions. Peripheral nerve conduction velocities are normal, and sensorimotor evoked potential studies show delayed conduction of stimuli to lower limbs. In patients with hearing loss, audiometric studies show a drop of >40dB in frequencies exceeding 2,500Hz. Auditory evoked potential studies may also show lack of waves I and II. CONCLUSIONS: Costa da Morte ataxia or SCA36 is the most prevalent SCA in the Spanish region of Galicia. Given the region's history of high rates of emigration, new cases may be diagnosed in numerous countries, especially in Latin America. Genetic studies are now available to patients and asymptomatic carriers. Since many people are at risk for this disease, we will continue our investigations aimed at elucidating the underlying pathogenic molecular mechanisms and discovering effective treatment.

Cellular changes, molecular pathways and the immune system following photodynamic treatment.

Photodynamic therapy (PDT) is a novel medical technique involving three key components: light, a photosensitizer molecule and molecular oxygen, which are essential to achieve the therapeutic effect. There has been great interest in the use of PDT in the treatment of many cancers and skin disorders. Upon irradiation with light of a specific wavelength, the photosensitizer undergoes several reactions resulting in the production of reactive oxygen species (ROS). ROS may react with different biomolecules, causing defects in many cellular structures and biochemical pathways. PDT-mediated tumor destruction in vivo involves cellular mechanisms with photodamage of mitochondria, lysosomes, nuclei, and cell membranes that activate apoptotic, necrotic and autophagic signals, leading to cell death. PDT is capable of changing the tumor microenvironment, thereby diminishing the supply of oxygen, which explains the antiangiogenic effect of PDT. Finally, inflammatory and immune responses play a crucial role in the long-lasting consequences of PDT treatment. This review is focused on the biochemical effects exerted by photodynamic treatment on cell death signaling pathways, destruction of the vasculature, and the activation of the immune system.

In vitro biocompatibility of Ti-45S5 bioglass nanocomposites and their scaffolds.

Titanium-10 wt % 45S5 Bioglass nanocomposites and their scaffolds were prepared by mechanical alloying (MA) followed by pressing, sintering, or combination of MA and a "space-holder" sintering process, respectively. An amorphous structure was obtained at 15 h of milling. The crystallization of the amorphous phase upon annealing led to the formation of a nanostructured Ti-10 wt % 45S5 Bioglass composite with a grain size of approximately 7 nm. The in vitro cytocompatibility of these materials was evaluated and compared with a conventional microcrystalline titanium. During the studies, established cell line of human fibroblasts CCD-39Lu was cultured in the presence of tested materials and its survival rate, and proliferation activity were examined. Furthermore, the influence of the Ti-45S5 Bioglass nanocomposites and microcrystalline titanium was tested on the growth of Candida albicans yeast. Biocompatibility tests carried out indicate that the nanocomposite Ti-10 wt % 45S5 Bioglass scaffolds could be a possible candidate for dental implants and other medicinal applications.

Clinical picture of a patient with a novel PSEN1 mutation (L424V).

Young onset dementia raises concern about familial and non degenerative dementias. We describe a patient with early dementia. At the age of 26, a woman developed symptoms of anorexia nervosa, at 30 a memory and attention deficit, and at 34 abnormal behavior with impulsivity, aggression, and dysexecutive disorder. At 36 she showed aphasia, stereotyped behavior, hyperreflexia, grasping reflex, urinary incontinence, myoclonus, and seizures. Blood and cerebrospinal fluid were normal. Brain computed tomography and single photon emission computed tomography showed diffuse cortico-subcortical atrophy and frontotemporoparietal hypoperfusion. A Leu424Val mutation was present in PSEN1 gene. PSEN1 mutations can produce Alzheimer's disease, frontotemporal dementia, and dementia with Lewy bodies phenotypes, or a combination of them. It has been proposed that the mutation type and location may influence the molecular pathogenesis and thus PSEN1 would represent a molecular connexion between these entities. This case shows a novel PSEN1 mutation with outstanding amnesic and frontal symptoms.

EEG mu rhythm and imitation impairments in individuals with autism spectrum disorder.

Imitation ability has consistently been shown to be impaired in individuals with autism. A dysfunctional execution/observation matching system has been proposed to account for this impairment. The EEG mu rhythm is believed to reflect an underlying execution/observation matching system. This study investigated evidence of differential mu rhythm attenuation during the observation, execution, and imitation of movements and examined its relation to behaviorally assessed imitation abilities. Fourteen high-functioning adults with autism spectrum disorder (ASD) and 15 IQ- and age-matched typical adults participated. On the behavioral imitation task, adults with ASD demonstrated significantly poorer performance compared to typical adults in all domains of imitation ability. On the EEG task, both groups demonstrated significant attenuation of the mu rhythm when executing an action. However, when observing movement, the individuals with ASD showed significantly reduced attenuation of the mu wave. Behaviorally assessed imitation skills were correlated with degree of mu wave attenuation during observation of movement. These findings suggest that there is execution/observation matching system dysfunction in individuals with autism and that this matching system is related to degree of impairment in imitation abilities.

Antitumor effects of 3,3',4,4',5,5'-hexahydroxystilbene in HL-60 human promyelocytic leukemia cells.

Resveratrol (3,4',5-trihydroxystilbene, RV) exerts remarkable cytostatic and cytotoxic effects against a multitude of human cancer cell lines. Since the introduction of additional hydroxyl groups was supposed to increase the biological activity of RV, we have synthesized a number of polyhydroxylated stilbene analogues as potential antitumor agents. In this study, the activity of 3,3',4,4',5,5'-hexahydroxystilbene (M8) was investigated in HL-60 human promyelocytic leukemia cells. Employing a growth inhibition assay, incubation with M8 and RV resulted in IC50 values of 6.25 and 12 microM, respectively. Using a specific Hoechst/propidium iodide double staining method, we found that M8 was able to induce apoptosis in concentrations significantly lower than those of RV. In addition, M8 arrested cells in the S phase and totally depleted cells in the G2-M phase of the cell cycle (143% and 0% of control after treatment with 12.5 microM M8, respectively). We therefore believe that this promising agent deserves further preclinical and in vivo testing.

Modulation of antioxidant defence system by dietary fat in rats intoxicated with o-toluidine.

o-Toluidine was administered to rats in the diet for four weeks at levels approximately 40, 80 and 160 mg/kg b.w. per day. Two types of diet have been used, standard (4% fat) and high fat (14% fat). Activity of antioxidant enzymes, level of glutathione and thiobarbituric acid reactive substances were measured in liver. Glutathione peroxidase was significantly increased in all treated groups while glutathione S-transferase and glutathione reductase were elevated in rats fed high-fat diet. o-Toluidine slightly enhanced catalase activity regardless of the kind of diet. Superoxide dismutase was the only enzyme whose activity was lowered in almost all treated groups. Enzymatic and nonenzymatic microsomal lipid peroxidation was enhanced 2- to 3-fold in both diet groups. Reduced glutathione level in liver was 2.3- to 4.0-fold increased in all treated groups. Our findings indicate that free radical processes can be involved in the toxic effects of o-toluidine and dietary fat can modify the response of some antioxidant enzymes to this compound.

Effect of sesquiterpene lactones on antioxidant enzymes and some drug-metabolizing enzymes in rat liver and kidney.

Previously we have reported that several sesquiterpene lactones isolated from Helenium aromaticum and Telekia speciosa showed pro-oxidative properties and caused glutathione level depletion in rat liver in vivo. In the present study we examined the in vivo effect of these lactones on antioxidant enzyme systems and some drug metabolizing enzymes in the liver and the kidney of rats. We found that the majority of the compounds increased the hepatic activity of glutathione peroxidase (GPx), glutathione reductase (GR), and catalase (CAT), but superoxide dismutase (SOD) activity was distinctly lowered by five lactones. A few of the compounds tested caused a decrease in the hepatic cytochrome P450 content and reduced the activity of NADPH-cytochrome P450 reductase, aminopyrine demethylase, aniline hydroxylase and glutathione-S-transferase. Results for the kidney showed fewer changes in activities of both classes of enzymes when compared to the liver. Not all lactones affected the enzymes under test, the most active were: linifolin, helenalin, mexicanin 1 and telekin. 6 alpha-Hydroxy-2,3-dihydroaromaticin behaved differently towards monooxygenases since it induced the activity of aminopyrine demethylase and aniline hydroxylase.

Attention deficit/hyperactivity disorder children with a 7-repeat allele of the dopamine receptor D4 gene have extreme behavior but normal performance on critical neuropsychological tests of attention.

An association of the dopamine receptor D4 (DRD4) gene located on chromosome 11p15.5 and attention deficit/hyperactivity disorder (ADHD) has been demonstrated and replicated by multiple investigators. A specific allele [the 7-repeat of a 48-bp variable number of tandem repeats (VNTR) in exon 3] has been proposed as an etiological factor in attentional deficits manifested in some children diagnosed with this disorder. In the current study, we evaluated ADHD subgroups defined by the presence or absence of the 7-repeat allele of the DRD4 gene, using neuropsychological tests with reaction time measures designed to probe attentional networks with neuroanatomical foci in D4-rich brain regions. Despite the same severity of symptoms on parent and teacher ratings for the ADHD subgroups, the average reaction times of the 7-present subgroup showed normal speed and variability of response whereas the average reaction times of the 7-absent subgroup showed the expected abnormalities (slow and variable responses). This was opposite the primary prediction of the study. The 7-present subgroup seemed to be free of some of the neuropsychological abnormalities thought to characterize ADHD.

Dopamine genes and ADHD.

Family, twin, and adoption studies have documented a strong genetic basis for ADHD/HKD, but these studies do not identify specific genes linked to the disorder. Molecular genetic studies can identify allelic variations of specific genes that are functionally associated with ADHD/HKD, and dopamine genes have been the initial candidates based on the site of action of the stimulants drugs, which for a half century have provided the primary pharmacological treatment for ADHD/HKD. Two candidate dopamine genes have been investigated and reported to be associated with ADHD/HKD: the dopamine transporter (DAT1) gene [Cook et al., American Journal of Human Genetics 1995;56:993-998, Gill et al., Molecular Psychiatry 1997;2:311-313] and the dopamine receptor D4 (DRD4) gene [LaHoste et al., Molecular Psychiatry 1996;1:121-124: Smalley et al., 1998;3:427-430; Swanson et al., Molecular Psychiatry 1998;3:38-41]. Speculative hypotheses [Swanson and Castellanos, NIH Consensus Development Conference: Diagnosis and Treatment of Attention Deficit Hyperactivity Disorder, November 1998. p. 37-42] have suggested that specific alleles of these dopamine genes may alter dopamine transmission in the neural networks implicated in ADHD/HKD (e.g. that the 10-repeat allele of the DAT1 gene may be associated with hyperactive re-uptake of dopamine or that the 7-repeat allele of the DRD4 gene may be associated with a subsensitive postsynaptic receptor). These and other variants of the dopamine hypothesis of ADHD will be discussed.

Detecting symmetric patterns in EEG data: a new method of analysis.

Theoretical models of higher cognitive function predict that cortical activity will exhibit families of spatial-temporal patterns of activity whose individual members are related to each other by specific symmetry transformations. In the trion model, it is suggested that these inherent symmetries play a vital role in how we think and reason. We have developed a method of analysis (SYMMETRIC analysis), which detects families of patterns in EEG data, and characterizes the symmetry relationships between members of those pattern families. Using this analysis, significant symmetry families have been found in EEG and single unit spike train data. If symmetry is a crucial aspect of brain function, it is possible that different pathologies are associated with specific types of symmetry relationships in brain activity that could be detected in EEG data by a SYMMETRIC analysis.

Effect of several sesquiterpene lactones on lipid peroxidation and glutathione level.

Seven sesquiterpene lactones isolated from Helenium aromaticum: helenalin, mexicanin I, linifolin A, geigerinin, and from Telekia speciosa: 6 alpha-hydroxy-2,3-dihydroaromaticin, asperilin, telekin have been tested for their hydroxyl radical scavenging activity and effect on lipid peroxidation. All compounds were found to be potent hydroxyl radical scavengers but did not affect lipid peroxidation in vitro. In vivo they exerted pro-oxidative properties and caused glutathione level depletion and elevation in glutathione peroxidase activity.

Cognitive neuroscience of attention deficit hyperactivity disorder and hyperkinetic disorder.

Currently, diagnoses of attention deficit hyperactivity disorder (ADHD) and hyperkinetic disorder (HKD) are made on the basis of phenomenology, but information is accumulating from the neurosciences about the biological bases of these disorders. Recent studies addressing the neuropsychology, neuroanatomy, neurochemistry, and molecular biology of ADHD/HKD document abnormalities in well-defined neuroanatomical networks and neurochemical pathways. Magnetic resonance imaging (MRI) studies have shown that some regions of the frontal lobes (anterior superior and inferior) and basal ganglia (caudate nucleus and globus pallidus) are about 10% smaller in ADHD groups than in control groups of children, and molecular genetic studies have shown that diagnosis of ADHD is associated with polymorphisms in some dopamine genes (the dopamine D4 receptor gene and the dopamine transporter gene).