Publications by authors named "Mena M"

Amyloid deposition is one of the central neuropathological abnormalities in Alzheimer's disease (AD) but it also takes places in many neurodegenerative diseases such as prionic disorders, Huntington's disease (HD) and others. Up to very recently amyloid formation was considered a very slow process of deposition of an abnormal protein due to genetic abnormalities or post-translational modification of the deposited protein. Recent data suggest that the process of amyloidogenesis may be much more rapid in many cases and due to multiple mechanisms.

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This study was designed to examine the type of changes experienced by the CB1 receptor, a key element of the cannabinoid signaling system, in the basal ganglia of different mouse mutants generated by deletion of specific genes associated with the development of Parkinson's disease in humans [PARK1 (alpha-synuclein), PARK2 (parkin) or PARK6 (PINK1)]. We observed that CB1 receptor-mRNA levels were significantly reduced in the caudate-putamen in the three models under examination when animals were analyzed at early phases (< or = 12 months of age). This decrease was, in general, associated with a reduction in CB1 receptor binding in the substantia nigra and the globus pallidus, particularly in the case of alpha-synuclein-deficient mice.

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Parkin mutations produce Parkinson's disease (PD) in humans and nigrostriatal dopamine lesions related to increased free radicals in mice. We examined the effects of NP7, a synthetic, marine derived, free radical scavenger which enters the brain, on H(2)O(2) toxicity in cultured neurons and glia from wild-type (WT) and parkin null mice (PK-KO). NP7, 5-10 microM, prevented the H(2)O(2) induced apoptosis and necrosis of midbrain neuronal and glial cultures from WT and PK-KO mice.

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The imido-nitrido complex [{Ti(eta(5)-C(5)Me(5))(mu-NH)}(3)(mu(3)-N)] entraps mercury(ii) or silver(i) halides MX(n) to give cube-type adducts [X(n)M{(mu(3)-NH)(3)Ti(3)(eta(5)-C(5)Me(5))(3)(mu(3)-N)}] which react with alkali metal bis(trimethylsilyl)amide reagents to afford [M(2){(mu(3)-N)(n)(mu(3)-NH)(2-n)Ti(3)(eta(5)-C(5)Me(5))(3)(mu-NH)(mu(3)-N)}(2)] (M = Hg, n = 2; M = Ag, n = 1) where two [Ti(3)N(4)] cores are linked by two mercury or silver atoms in a linear geometry.

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Background: Adherence to the Mediterranean diet (Med-Diet) is associated with a reduced risk of cardiovascular disease (CVD). However, the molecular mechanisms involved are not fully understood.

Objective: The objective was to compare the effects of 2 Med-Diets with those of a low-fat diet on immune cell activation and soluble inflammatory biomarkers related to atherogenesis in subjects at high risk of CVD.

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Hirschsprung disease (HSCR) is a developmental disorder characterized by the absence of ganglion cells in the myenteric and submucosal plexuses due to a defect in the migration process of neural crest neuroblasts. Manifestation of the disease has been linked to the dysfunction of two principal signalling pathways involved in the enteric nervous system (ENS) formation: the RET-GDNF and the EDN3-EDNRB receptor systems. However, the NTF3/NTRK3 signalling pathway plays an essential role in the development of the ENS suggesting a potential role for those genes in the pathogenesis of HSCR.

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The role of glia in Parkinson's disease (PD) is very interesting because it may open new therapeutic strategies in this disease. Traditionally it has been considered that astrocytes and microglia play different roles in PD: Astroglia are considered the "good" glia and have traditionally been supposed to be neuroprotective due to their capacity to quench free radicals and secrete neurotrophic factors, whereas microglia, considered the "bad" glia, are thought to play a critical role in neuroinflammation. The proportion of astrocytes surrounding dopamine (DA) neurons in the substantia nigra, the target nucleus for neurodegeneration in PD, is the lowest for any brain area, suggesting that DA neurons are more vulnerable in terms of glial support than any neuron in other brain areas.

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Parkinson's disease (PD) is a neurodegenerative disorder affecting nearly 3 million patients in Europe and North America, characterized by a core phenotype of motor deficits, akinesia, rigidity, postural disturbance and tremor, which is complicated by other neurological deficits during its long progression. Our knowledge about the pathophisiology of PD was limited, up to 25 years ago, to the observation of the lesion of the nigro-striatal dopamine neurons in these patients. The subjects who developed PD as a consequence of exposure to neurotoxic compounds, increased our knowledge about the pathogenesis of this disease.

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Using a positional cloning approach supported by comparative genomics, we have identified a previously unreported gene, EYS, at the RP25 locus on chromosome 6q12 commonly mutated in autosomal recessive retinitis pigmentosa. Spanning over 2 Mb, this is the largest eye-specific gene identified so far. EYS is independently disrupted in four other mammalian lineages, including that of rodents, but is well conserved from Drosophila to man and is likely to have a role in the modeling of retinal architecture.

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Estrogens are considered neurotrophic for dopamine neurons. Parkinson's disease is more frequent in males than in females, and more prevalent in females with short reproductive life. Estrogens are neuroprotective against neurotoxic agents for dopamine neurons in vivo and in vitro.

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Treatment of [{TiCp*(mu-NH)} 3(mu 3-N)] ( 1; Cp* = eta (5)-C 5Me 5) with yttrium and erbium halide complexes [MCl 3(THF) 3.5] and [MCpCl 2(THF) 3] (Cp = eta (5)-C 5H 5) gives cube-type adducts [Cl 3M{(mu 3-NH) 3Ti 3Cp* 3(mu 3-N)}] and [CpCl 2M{(mu 3-NH) 3Ti 3Cp* 3(mu 3-N)}]. An analogous reaction of 1 with [{MCp 2Cl} 2] in toluene affords [Cp 3M(mu-Cl)ClCpM{(mu 3-NH) 3Ti 3Cp* 3(mu 3-N)}] (M = Y, Er).

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Deposition of proteins leading to amyloid takes place in some neurodegenerative diseases such as Alzheimer's disease and Huntington's disease. Mutations of tau and parkin proteins produce neurofibrillary abnormalities without deposition of amyloid. Here we report that mature, parkin null, over-expressing human mutated tau (PK(-/-)/Tau(VLW)) mice have altered behaviour and dopamine neurotransmission, tau pathology in brain and amyloid deposition in brain and peripheral organs.

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A family of novel titanasiloxanes containing the structural unit ([Ti(eta 5-C5Me5)O]3) were synthesized by hydron-transfer processes involving reactions with equimolecular amounts of mu3-alkylidyne derivatives [(Ti(eta 5-C5Me5)(mu-O))(3)(mu3-CR)] (R=H (1), Me (2)) and monosilanols, R3'Si(OH), silanediols, R2'Si(OH)2, and the silanetriol tBuSi(OH)3. Treatment of 1 and 2 with triorganosilanols (R'=Ph, iPr) in hexane affords the new metallasiloxane derivatives [(Ti(eta 5-C5Me5)(mu-O))(3)(mu-CHR)(OSiR3')] (R=H, R'=Ph (3), iPr (4); R=Me, R'=Ph (5), iPr (6)). Analogous reactions with silanediols, (R'=Ph, iPr), give the cyclic titanasiloxanes [(Ti(eta 5-C5Me5)(mu-O))(3)(mu-O2SiR'2)(R)] (R=Me, R'=Ph (7), iPr (8); R=Et, R'=Ph (9), iPr (10)).

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In a model of glial-specific chemical anoxia, we have examined how astrocytes influence both synaptic transmission and the viability of hippocampal pyramidal neurons. This relationship was assessed using electrophysiological, pharmacological, and biochemical techniques in rat slices and cell cultures, and oxidative metabolism was selectively impaired in glial cells by exposure to the mitochondrial gliotoxin, fluoroacetate. We found that synaptic transmission was blocked shortly after inducing glial metabolic stress and peri-infarct-like spreading depression (SD) waves developed within 1 to 2 h of treatment.

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Fibroblast growth factors (FGFs) are important for dopamine neurons in health and disease. Acidic (aFGF) and basic (bFGF) fibroblast growth factors increase the survival and growth of dopamine cells. Nigrostriatal dopamine neurons, the target cells for degeneration in Parkinson's disease, display receptors for basic fibroblast growth factor and these receptors are decreased in the brain of parkinsonian patients.

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Objectives: We have investigated the extent of contamination with wheat, barley, rye or a mixture of these cereals in a large number of grains and commercial oats. We have also attempted to identify the type of cereal contaminant.

Methods: Sandwich R5 ELISA (using either gliadins or hordeins as standards), western blot, matrix-assisted laser desorption/ionization time-of-flight mass spectrometric and quantitative real-time PCR (Q-PCR) techniques have been used to analyze a total of 134 oats, comprising grains and commercial oat products collected from Europe, the United States and Canada.

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The [{TiCp*(micro-O)}3(mu3-CH)] (1) metalloligand, (Cp* = eta5-C5Me5), coordinates in a 1:1 ratio to [AlMe3] or 9-BBN to give [{Me3Al}{(mu3-O)(mu-O)2(TiCp)2(TiCp)3(mu3-CH)}](2) or [{(C8H14)B}(mu-H) {(mu3-O)(mu-O)2(TiCp*)3(mu3-CH)}](4), respectively, partial hydrolysis of 2 leads to the new hydroxo-aluminium derivative [{MeAl} {(mu-OH)(mu3-O)}2{(mu-O)2(TiCp*)3-(mu3-CH)}2](3).

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A biosensor design involving coimmobilization of fructose dehydrogenase (FDH) and inulinase (INU) on a gold nanoparticle-cysteamine (Cyst) self-assembled monolayer (SAM)-modified gold electrode (Au(coll)-Cyst-AuE), for the determination of the carbohydrate inulin in foodstuffs, is reported. Tetrathiafulvalene (TTF), used as the mediator, was also coimmobilized by crosslinking with glutaraldehyde. INU catalyzes the hydrolysis of inulin, forming fructose that is detected through the fructose dehydrogenase system by the electrochemical oxidation of TTF at the bioelectrode.

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Parkin mutations in humans produce parkinsonism whose pathogenesis is related to impaired protein degradation, increased free radicals, and abnormal neurotransmitter release. The role of glia in parkin deficiency is little known. We cultured midbrain glia from wild-type (WT) and parkin knock-out (PK-KO) mice.

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Hispanic adolescents have been shown to have high prevalence of sexually transmitted infections and HIV, and substance abuse has been linked to risky sexual behaviors. The literature indicates that good parent-adolescent communication about sexual risk and safe sexual behaviors may help protect youth, yet little is known about this type of communication in Hispanic families. This article reports data on adolescent and parent factors associated with communication about moral and birth control talk between 108 Hispanic substance abusing adolescents and their parents.

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Background: Moderate alcohol consumption is cardioprotective. The mechanism for this beneficial effect might be reduced inflammatory responses, as suggested by prospective studies and small clinical trials in men. No studies have evaluated the antiinflammatory effects of wine in women.

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In this paper is considered a new computerized approach to the determination of concentrations of phenolic compounds (caffeic acid and catechol). An integrated artificial neural network (ANN)/laccase biosensor is designed. The data collected (current signals) from amperometric detection of the laccase biosensor were transferred into an ANN trained computer for modeling and prediction of output.

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