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Find video protocols related to scientific articles indexed in Pubmed.
Aldehyde dehydrogenase 2 in sporadic Parkinson's disease.
Parkinsonism Relat. Disord.
PUBLISHED: 07-12-2014
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Aldehyde dehydrogenases (ALDH) play a key role in neuronal protection. They exert this function by metabolizing biogenic amine-related aldehydes, e.g. 3,4-dihydroxyphenylacetaldehyde (DOPAL), and by protecting neurons against aldehyde- and oxidative stress-related neurotoxicity. The role of these different isoenzymes has been discussed in other neurodegenerative disorders before. It is somewhat surprising that only few studies have investigated their role in the aetiology of Parkinson's disease (PD), in both the degeneration of dopaminergic neurons and the formation of Lewy bodies. Earlier studies report severe alterations of the cytosolic isoform of ALDH expression (ALDH 1A1) in the substantia nigra of patients with PD. However, there are no data regarding the activity of ALDH 2 located at the inner mitochondrial membrane. Since mitochondrial dysfunctions are hypothesized to be of importance in the aetiology of PD we have examined the enzymatic activity of mitochondrial ALDH 2 in post-mortem putamen and frontal cortex of patients with PD and controls. We found that mitochondrial ALDH 2 activity in contrast to the frontal cortex was significantly increased in the putamen of patients with PD compared to controls.
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Cholinergic blockade under working memory demands encountered by increased rehearsal strategies: evidence from fMRI in healthy subjects.
Eur Arch Psychiatry Clin Neurosci
PUBLISHED: 06-03-2011
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The connection between cholinergic transmission and cognitive performance has been established in behavioural studies. The specific contribution of the muscarinic receptor system on cognitive performance and brain activation, however, has not been evaluated satisfyingly. To investigate the specific contribution of the muscarinic transmission on neural correlates of working memory, we examined the effects of scopolamine, an antagonist of the muscarinic receptors, using functional magnetic resonance imaging (fMRI). Fifteen healthy male, non-smoking subjects performed a fMRI scanning session following the application of scopolamine (0.4 mg, i.v.) or saline in a placebo-controlled, repeated measure, pseudo-randomized, single-blind design. Working memory was probed using an n-back task. Compared to placebo, challenging the cholinergic transmission with scopolamine resulted in hypoactivations in parietal, occipital and cerebellar areas and hyperactivations in frontal and prefrontal areas. These alterations are interpreted as compensatory strategies used to account for downregulation due to muscarinic acetylcholine blockade in parietal and cerebral storage systems by increased activation in frontal and prefrontal areas related to working memory rehearsal. Our results further underline the importance of cholinergic transmission to working memory performance and determine the specific contribution of muscarinic transmission on cerebral activation associated with executive functioning.
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Prestimulus vigilance predicts response speed in an easy visual discrimination task.
Behav Brain Funct
PUBLISHED: 04-21-2011
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Healthy adults show considerable within-subject variation of reaction time (RT) when performing cognitive tests. So far, the neurophysiological correlates of these inconsistencies have not yet been investigated sufficiently. In particular, studies rarely have focused on alterations of prestimulus EEG-vigilance as a factor which possibly influences the outcome of cognitive tests. We hypothesised that a low EEG-vigilance state immediately before a reaction task would entail a longer RT. Shorter RTs were expected for a high EEG-vigilance state.
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Impact of antipsychotics on cytokine production in-vitro.
J Psychiatr Res
PUBLISHED: 02-11-2011
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A growing body of data from genetic, immunological and clinical studies indicates an involvement of the immune system in the pathophysiology of schizophrenia and suggests that the modulation of the cytokine system by antipsychotics may be one cause for the improvement of psychotic symptoms. However, the influence of the typical antipsychotics chlorpromazine and haloperidol, and the effect of typical and atypical antipsychotics on the TSST-1-stimulated blood cell secretion of cytokines, and specifically the interleukin (IL)-17 production have not been studied so far, although IL-17 is a leading pro-inflammatory cytokine.
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Alteration of the pro-oxidant xanthine oxidase (XO) in the thalamus and occipital cortex of patients with schizophrenia.
World J. Biol. Psychiatry
PUBLISHED: 11-15-2010
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Mounting evidence shows that oxidative stress (OS) and the purine/adenosine system play a key role in the pathophysiology of schizophrenia. Lately, our group pointed out that not only antioxidants, but also the prooxidant system plays an important role in neuro-psychiatric disorders. Xanthine oxidase (XO) is an enzyme of special interest in this context, since it acts as a prooxidant, but its main product is a vastly important antioxidant, uric acid (UA). Furthermore, XO plays major part in the purine/adenosine metabolism, which has been hypothesised to play a role in schizophrenia as well.
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Laboratory parameters and appetite regulators in patients with anorexia nervosa.
J Psychiatr Pract
PUBLISHED: 06-01-2010
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Anorexia nervosa (AN) has serious negative effects on multiple organs and systems of the human body. As patients often do not make their eating disorder the subject of discussion, the physician is forced to rely on the physical examination and laboratory parameters as diagnostic hints. Obvious signs of AN are a body mass index (BMI) below 17.5 kg/m, dry and scaly skin, lanugo, edema, acrocyanosis, petechias, dental problems, and low blood pressure. However, because the often complex laboratory alterations can be difficult for the general psychiatrist to interpret, this article presents some useful guidelines. The plasma of patients with AN often shows alterations in laboratory parameters and appetite regulators, including electrolytes, liver enzymes, leukocyte count, hemoglobin (Hb), leptin, neuropeptide Y (NPY), triiodothyronine (T3), follicle-stimulating hormone (FSH), luteinizing hormone (LH), estrogen, ghrelin, pancreatic polypeptide (PP), tumor necrosis factor-alpha (TNF-alpha), and cortisol. Medical problems secondary to AN or due to the treatment itself may lead to further laboratory abnormalities. To date, despite these associated laboratory alterations, the diagnosis of anorexia is a clinical one, based on weight and specific psychopathology.
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Can enzyme kinetics of prooxidants teach us a lesson about the treatment of Alzheimers disease: a pilot post-mortem study.
World J. Biol. Psychiatry
PUBLISHED: 04-13-2010
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Oxidative stress (OS), is defined as an imbalance of pro- and antioxidants, leading to increased production of free radicals, which can lead to cell damage and death, has been postulated as important factors in the pathogenesis of neurodegenerative disorders such as Alzheimers disease (AD). Most research has concentrated on the antioxidant system, for the first time, this proof of concept study examines the prooxidant system by investigating kinetic parameters of the free radical producing enzyme xanthine oxidase directly in post mortem brain tissue.
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Increased xanthine oxidase in the thalamus and putamen in depression.
World J. Biol. Psychiatry
PUBLISHED: 03-12-2010
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A growing body of literature suggests persistent and selective structural changes in the cortico-limbic-thalamic-striatal system in patients with recurrent depressive disorder (DD). Oxidative stress is thought to play a key role in these processes. So far, the main scientific focus has been on antioxidant enzymes in this context. For the first time, this proof of concept study examines the activity of the free radicals producing the enzyme, xanthine oxidase (XO), directly in the cortico-limbic-thalamic-striatal system of patients with recurrent depression. The activity of XO was ascertained in the cortico-limbic-thalamic-striatal regions in post-mortem brain tissue of patients with recurrent depressive episodes and individuals without any neurological or psychiatric history (7/7). We measured the XO activity in following brain areas: hippocampus, regio entorhinalis, thalamus, putamen and caudate nucleus. In this study, we report a significant increase of XO activity in the thalamus and the putamen of patients with depression. Our findings contribute to the growing body of evidence suggesting that oxidative stress plays a pivotal role in certain brain areas in recurrent depressive disorder.
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TNF-alpha and ghrelin: opposite effects on immune system, metabolism and mental health.
Protein Pept. Lett.
PUBLISHED: 03-11-2010
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Tumor necrosis factor-alpha (TNF-alpha) is a glycoprotein hormone with important functions in inflammation and apoptosis. It plays a significant role as a pro-inflammatory cytokine in the defense against viral, bacterial and parasitic infections and autoimmune disorders. Furthermore, it influences energy homeostasis and has an anorexigenic effect on the hypothalamus. TNF-alpha has also been shown to be involved in the pathogenesis of psychiatric disorders such as depression or narcolepsy. Ghrelin is a peptide hormone which primarily regulates eating behavior through modulation of expression of orexigenic peptides in the hypothalamus. Ghrelin administration increases food intake and body weight, while weight loss in turn increases ghrelin levels. Secondly, it posesses anti-inflammatory properties. It also seems to have an impact on mental health as it is has been suggested to have antidepressant and anxiolytic properties. Therefore, TNF-alpha and ghrelin seem to have opposite effects regarding the hypothalamic regulation of eating behavior, modulation of the immune response and the state of mental health.
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Regulatory T cells increased while IL-1? decreased during antidepressant therapy.
J Psychiatr Res
PUBLISHED: 01-15-2010
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Regulatory T cells (Tregs, CD4(+)CD25(hi)) are specialized in steering the immune response and cytokine release to maintain tolerance to self-antigens. As cytokines such as interleukin (IL)-1?, IL-6 and interferon (IFN)-? have been shown to be involved in the pathophysiology of depression and cytokine levels have been shown to change during successful antidepressant treatment, we tested the involvement CD4(+)CD25(hi) Tregs in these immunological processes during antidepressant therapy.
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COMT genotype and its role on hippocampal-prefrontal regions in declarative memory.
Neuroimage
PUBLISHED: 01-11-2010
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Memory dysfunction is a prominent feature in schizophrenia. Impairments of declarative memory have been consistently linked to alterations especially within hippocampal-prefrontal regions. Due to the high heritability of schizophrenia, susceptibility genes and their modulatory impact on the neural correlates on memory are of major relevance. In the present study the influence of the COMT val(158)met status on the neural correlates of declarative memory was investigated in healthy subjects.
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Muscarinic antagonist effects on executive control of attention.
Int. J. Neuropsychopharmacol.
PUBLISHED: 10-01-2009
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Acetylcholine plays a major role in mediating attention processes. We investigated the muscarinic antagonist effect of scopolamine on functional neuro-anatomy of attention and cognition. We assessed 12 healthy volunteers while performing the Attention Network Task on 0.4 mg scopolamine and placebo in a single-blind randomized trial in a 1.5 T magnetic resonance scanner. Neurocognitive measures included verbal learning, verbal memory, verbal fluency, trail making, digit span, a continuous performance task and a planning task (Tower of London). When compared to placebo, scopolamine increased reaction times for conflicting stimulus processing, together with decreasing brain activation in the anterior cingulate cortex (a brain region involved in conflict processing) suggestive of a muscarinic antagonist effect on executive control of attention. Contrary to the notion of a predominantly right-hemispheric lateralization of cognitive processes associated with orienting attention, scopolamine reduced brain activity in left superior and left middle frontal brain areas. Our neuropsychological test data revealed a selective effect of scopolamine on verbal learning and memory while other cognitive domains, such as planning and working memory, were unaffected. These findings are consistent with muscarinic modulation of dopaminergic neurotransmission in frontal attention networks when processing conflicting information.
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Nicotinic antagonist effects on functional attention networks.
Int. J. Neuropsychopharmacol.
PUBLISHED: 09-09-2009
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Cholinergic neurotransmission has been implicated in memory and attention. We investigated the effect of the non-competitive nicotinic antagonist mecamylamine on three components of attention processes (i.e. alerting, orienting and executive control) in 12 healthy male subjects whilst performing the Attention Network Task (ANT) in a magnetic resonance imaging (MRI) scanner. Participants received 15 mg mecamylamine in a single blind and placebo- controlled randomized procedure 90 min prior to obtaining functional MRI data. Our results confirm previous reports of beneficial effects of cueing (alerting and orienting) and detrimental effects of conflict (executive control) on reaction times when performing the ANT. The functional MRI data confirmed distinct neural networks associated with each of the three attention components. Alerting was associated with increased left temporal lobe activation while orienting increased bilateral prefrontal, right precuneus and left caudate activation. Executive control activated anterior cingulate and precuneus. Mecamylamine slowed overall response time and down-regulated brain activation associated with orienting and to some extent brain activation associated with executive control when compared to placebo. These findings are consistent with nicotinic modulation of orienting attention by cueing and executive control when responding to conflicting information. The latter nicotine antagonist effect may be mediated via cholinergic modulation of dopamine neurotransmission in mesolimbic pathways.
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The effect of the COMT val(158)met polymorphism on neural correlates of semantic verbal fluency.
Eur Arch Psychiatry Clin Neurosci
PUBLISHED: 03-31-2009
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Variation in the val(158)met polymorphism of the COMT gene has been found to be associated with cognitive performance. In functional neuroimaging studies, this dysfunction has been linked to signal changes in prefrontal areas. Given the complex modulation and functional heterogeneity of frontal lobe systems, further specification of COMT gene-related phenotypes differing in prefrontally mediated cognitive performance are of major interest. Eighty healthy individuals (54 men, 26 women; mean age 23.3 years) performed an overt semantic verbal fluency task while brain activation was measured with functional magnetic resonance imaging (fMRI). COMT val(158)met genotype was determined and correlated with brain activation measured with fMRI during the task. Although there were no differences in performance, brain activation in the left inferior frontal gyrus [Brodmann area 10] was positively correlated with the number of val alleles in the COMT gene. COMT val(158)met status modulates brain activation during the language production on a semantic level in an area related to executive functions.
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From psychosurgery to neuromodulation: deep brain stimulation for intractable Tourette syndrome.
World J. Biol. Psychiatry
PUBLISHED: 02-20-2009
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Tourette syndrome is a neuropsychiatric disorder characterized by motor and vocal tics. It is often associated with depression, obsessive-compulsive symptoms, self-injurious behaviour and attention deficit-hyperactivity disorder (ADHD). In intractable patients, neuromodulation using deep brain stimulation (DBS) has widely replaced psychosurgery. Three different key structures are defined for DBS, the medial portion of the thalamus, the globus pallidus internus and the anterior limb of the internal capsule/nucleus accumbens. This is a comprehensive overview on the effect of DBS on motor and non-motor symptoms using different case series and two larger studies.
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Time perception at different EEG-vigilance levels.
Behav Brain Funct
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Human time perception is influenced by various factors such as attention and drowsiness. Nevertheless, the impact of cerebral vigilance fluctuations on temporal perception has not been sufficiently explored. We assumed that the state of vigilance ascertained by electroencephalography (EEG) during the perception of a given auditory rhythm would influence its reproduction. Thus, we hypothesised that the re-tapping interval length and the accuracy of reproduction performance would vary depending on the state of vigilance determined by EEG.
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Impact of clozapine, N-desmethylclozapine and chlorpromazine on thromboxane production in vitro.
Med Chem
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Thromboxane A2 (TxA2) and the activation of its receptor have been shown to modulate vasoconstriction and platelet aggregation as well as dopaminergic and serotonergic signalling. Dopaminergic and serotonergic systems play a crucial role in the pathophysiology of schizophrenia and these systems are the main targets of antipsychotics (APs). As the first antipsychotic (AP) chlorpromazine (CPZ) has already been shown to reduce TxA2, we hypothesized that the AP clozapine and its metabolite N-desmethylclozapine (NDMC) might also influence TxA2 production. We measured levels of thromboxane B2 (TxB2), the metabolite of the very unstable molecule TxA2, in unstimulated and stimulated blood samples of 10 healthy female subjects in a whole blood assay using toxic shock syndrome toxin-1 (TSST-1) and monoclonal antibody against surface antigen CD3 combined with protein CD40 (OKT3/CD40) as stimulants. Blood was supplemented with the APs CPZ, clozapine or NDMC in one of four different concentrations. Additionally, thromboxane levels were measured in blood without the addition of APs under different stimulation conditions. Under TSST-1 as well as OKT3/CD40 stimulation, mean TxB2 concentrations were significantly (p < 0.05) decreased by clozapine over all applied concentrations. NDMC led to a decrease in TxB2 levels under unstimulated conditions as well as under TSST-1 stimulation. CPZ reduced TxB2 production at low concentrations under unstimulated and TSST-1- stimulated conditions. Clozapine, NDMC and CPZ possibly act on neurotransmitter systems via modulation of TxA2 or TxB2 production. Additionally, known side effects of APs such as orthostatic hypotension may be a result of changes in the concentrations of TxA2 or TxB2.
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Lack of data on depression-like states and antidepressant pharmacotherapy in patients with epilepsy: randomised controlled trials are badly needed.
Curr. Pharm. Des.
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The prevalence of depression in patients with epilepsy (PWE) is high. To elucidate the nature of depression in PWE, a comparison was made between PWE and patients with idiopathic depression (PWID), applying 3 test batteries: Beck Depression Inventory II (BDI-II), Center for Epidemiologic Studies Depression Scale (CES-D) and Buss-Perry Aggression Questionnaire (BAQ). The former 2 rating scales were developed to measure depressive symptoms, while the latter was designed to detect anger and aggressive states. As a result, the group of patients with PWE showed significantly higher BAQ scores in comparison to those with PWID. Further, the BAQ and BDI scores were closely related within a group of PWE, while BAQ and BDI scores were not correlated with each other within a group of PWID. With regard to pharmaceutical therapy, the safety of antidepressants, especially SSRIs, is well established. However, there has been only one randomized controlled trial (RCT) thus far, which failed to show a significant difference in efficacy between placebo and various antidepressants. In contrast, there are two RCTs regarding the efficacy of LTG. The clinical profile of the depressiolytic effects of LTG in PWE may be different from that of antidepressants in patients with idiopathic depression, in that BAQ is more sensitive measure than BDI or CES-D. It is now widely recognized that the failure to treat depression in PWE can result in serious consequences. However, even a fundamental question, such as whether antidepressants are as effective in this population as in PWID, remains to be answered.
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Neurobiology of depression and novel antidepressant drug targets.
Curr. Pharm. Des.
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Depression is one of the most common psychiatric conditions affecting numerous individuals in the world. However, the currently available antidepressant medication shows low response and remission rates. Thus, new antidepressants need to be discovered or developed. Aiming to describe the current neurobiological hypotheses regarding the pathophysiology of depression and in order to give an overview of novel possible antidepressant drug targets, we reviewed publications and studies referring to the neurobiology of depression. This review included genetics, epigenetics and gene expression, neuroanatomy and structural anatomy, neurochemistry, neuroendocrinology, neuroimmunology and novel drug targets using a MEDLINE/Pubmed search. The search was augmented by a manual search of bibliographies, textbooks, and abstracts from recent scientific meetings. On the one hand, the literature reveals in part contradictory information, but on the other hand, it shows convergent information regarding the relevance of research targets apart from the monoamine deficiency hypothesis of depression such as epigenetic phenomena and changes in neuronal and glial function and structure. Recent neurobiological findings in these areas of research provide multidimensional perspectives for the progress in the psychopharmacological treatment of depression.
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Accessibility, standards and challenges of electroconvulsive therapy in Western industrialized countries: a German example.
World J. Biol. Psychiatry
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The aim of the study was to document the present situation of electroconvulsive therapy (ECT) in Germany, compare its handling with regard to other industrialized countries and with regard to a survey 12 years ago.
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Alcohol consumption, genetic variants in alcohol deydrogenases, and risk of cardiovascular diseases: a prospective study and meta-analysis.
PLoS ONE
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First, to investigate and compare associations between alcohol consumption and variants in alcohol dehydrogenase (ADH) genes with incidence of cardiovascular diseases (CVD) in a large German cohort. Second, to quantitatively summarize available evidence of prospective studies on polymorphisms in ADH1B and ADH1C and CVD-risk.
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What is Visualize?

JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

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We use abstracts found on PubMed and match them to JoVE videos to create a list of 10 to 30 related methods videos.

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In developing our video relationships, we compare around 5 million PubMed articles to our library of over 4,500 methods videos. In some cases the language used in the PubMed abstracts makes matching that content to a JoVE video difficult. In other cases, there happens not to be any content in our video library that is relevant to the topic of a given abstract. In these cases, our algorithms are trying their best to display videos with relevant content, which can sometimes result in matched videos with only a slight relation.