1,199 research outputs found
The competitive NMDA antagonist CPP protects substantia nigra neurons from MPTP-induced degeneration in primates
Degeneration of nigrostriatal dopaminergic neurons is the primary histopathological feature of Parkinson's disease. The neurotoxin MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) induces a neurological syndrome in man and non-human primates very similar to idiopathic Parkinson's disease by selectively destroying dopaminergic nigrostriatal neurons. This gives rise to the hypothesis that Parkinson's disease may be caused by endogenous or environmental toxins. Endogenous excitatory amino acids (EAAs) such as L-glutamate could be involved in neurodegenerative disorders including Parkinson's disease. We report in this study that the competitive NMDA antagonist CPP (3-((+/-)-2-carboxypiperazin-4-yl)-propyl-1-phosphonic acid) protects nigral tyrosine hydroxylase (TH) positive neurons from degeneration induced by systemic treatment with MPTP in common marmosets. This indicates that EAAs are involved in the pathophysiological cascade of MPTP-induced neuronal cell death and that EAA antagonists may offer a neuroprotective therapy for Parkinson's disease
Headache in 25 consecutive patients with atrial septal defects before and after percutaneous closure â a prospective case series
In contrast to patent foramen ovale, that is highly prevalent in the general population, atrial
septal defect (ASD) is a rare congenital heart defect. The effect of ASD closure on headache
and migraine remains a matter of controversy. The objectives of the study were (i) to
determine headache prevalence in consecutive patients with ASD scheduled for percutaneous
closure for cardiologic indications, using the classification of the International Headache
Society and (ii) to compare headache characteristics before and after closure of ASD. In this
observational case series no a priori power analysis was performed. Twenty-five consecutive
patients were prospectively included over 27 months. Median duration of follow-up was 12
months, [Interquartile range 0]. Prevalence of active headache seemed to be increased
compared to the general population: Any headaches 88% (95% confidence interval 70-96),
migraine without aura 28% (14-48), migraine with aura 16% (6-35). After ASD closure, we
observed a slightly lower headache frequency (median frequency 1.0 [2.6] vs. 0.3 [1.5]
headaches per month; p=0.067). In patients with ongoing headaches, a significant decrease in
headache intensity (median VAS 7 [3] vs. 5 [4]; p=0.036) was reported. Three patients with
migraine with aura before the intervention reported no migraine with aura attacks at followup,
two of them reported ongoing tension-type headache, one migraine without aura. In
summary, this prospective observational study confirms the high prevalence of headache,
particularly migraine, in ASD patients and suggests a possible small beneficial effect of ASD
closure
Transcriptional alterations under continuous or pulsatile dopaminergic treatment in dyskinetic rats
Continuous dopaminergic treatment is considered to prevent or delay the occurrence of dyskinesia in patients with Parkinson's disease (PD). Rotigotine is a non-ergolinic D3>D2>D1 dopamine-receptor agonist for the treatment of PD using a transdermal delivery system providing stable plasma levels. We aimed to investigate the differential influence on gene expression of pulsatile l-DOPA or rotigotine versus a continuous rotigotine treatment. The gene expression profile within the nigro-striatal system of unilateral 6-hydroxydopamine-lesioned rats was assessed in order to differentiate potential changes in gene expression following the various treatment using Affymetrix microarrays and quantitative RT-PCR. The expression of 15 genes in the substantia nigra and of 11 genes in the striatum was altered under pulsatile treatments inducing dyskinetic motor response, but was unchanged under continuous rotigotine treatment that did not cause dyskinetic motor response. The route of administration of a dopaminergic drug is important for the induction or prevention of motor abnormalities and adaptive gene expressions. The decline of neurotrophin-3 expression under pulsatile administration was considered of particular importanc
Modeling sporadic alzheimer's disease: the insulin resistant brain state generates multiple long-term morphobiological abnormalities inclusive hyperphosphorylated tau protein and amyloid-beta. A Synthesis
Nosologically, Alzheimer's disease (AD) is not a single disorder. Missense gene mutations involved in increased formation of the amyloid-beta protein precursor derivatives amyloid-beta (Abeta)_{1-40} and Abeta_{1-42/43} lead to autosomal dominant familial AD, found in the minority of AD cases. However, millions of subjects suffer from sporadic AD (sAD) of late onset, for which no convincing evidence suggests Abeta as the primary disease-generating compound. Environmental factors operating during pregnancy and postnatally may affect susceptibility genes and stress factors (e.g., cortisol), consequently affecting brain development both structurally and functionally, causing disorders becoming manifest late in life. With aging, a desynchronization of biological systems may result, increasing further brain entropy/declining criticality. In sAD, this desynchronization may involve stress components, cortisol and noradrenaline, reactive oxygen species, and membrane damage as major candidates causing an insulin resistant brain state with decreased glucose/energy metabolism. This further leads to a derangement of ATP-dependent cellular and molecular work, of the cell function in general, as well as derangements in the endoplasmic reticulum/Golgi apparatus, axon, synapses, and membranes, in particular. A self-propagating process is thus generated, including the increased formation of hyperphosphorylated tau-protein and Abeta as abnormal terminal events in sAD rather than causing the disorder, as elaborated in the review
Molecular semiconductors and the IoffeâRegel criterion: A terahertz study on band transport in DBTTT
Terahertz electromodulation spectroscopy provides insight into the physics of charge carrier transport in molecular semiconductors. The work focuses on thin-film devices of dibenzothiopheno[6,5-b:6âČ,5âČ-f]thieno[3,2-b]thiophene. Frequency-resolved data show a Drude-like response of the hole gas in the accumulation region. The temperature dependence of the mobilities follows a T1/2 power law. This indicates that the thermal mean free path of the charge carriers is restricted by disorder. Only a fraction of approximately 5% of the injected carriers fulfills the IoffeâRegel criterion and participates in band transport.info:eu-repo/semantics/publishe
cAMP-dependent and cholinergic regulation of the electrogenic intestinal/pancreatic Na+/HCO3- cotransporter pNBC1 in human embryonic kidney (HEK293) cells
<p>Abstract</p> <p>Background</p> <p>The renal (kNBC1) and intestinal (pNBC1) electrogenic Na<sup>+</sup>/HCO<sub>3</sub><sup>- </sup>cotransporter variants differ in their primary structure, transport direction, and response to secretagogues. Previous studies have suggested that regulatory differences between the two subtypes can be partially explained by unique consensus phosphorylation sites included in the pNBC1, but not the kNBC1 sequence. After having shown activation of NBC by carbachol and forskolin in murine colon, we now investigated these pathways in HEK293 cells transiently expressing a GFP-tagged pNBC1 construct. </p> <p>Results</p> <p>Na<sup>+</sup>- and HCO<sub>3</sub><sup>-</sup>-dependent pH<sub>i </sub>recovery from an acid load (measured with BCECF) was enhanced by 5-fold in GFP-positive cells compared to the control cells in the presence of CO<sub>2</sub>/HCO<sub>3</sub><sup>-</sup>. Forskolin (10<sup>-5 </sup>M) had no effect in untransfected cells, but inhibited the pH<sub>i </sub>recovery in cells expressing pNBC1 by 62%. After preincubation with carbachol (10<sup>-4 </sup>M), the pH<sub>i </sub>recovery was enhanced to the same degree both in transfected and untransfected cells, indicating activation of endogenous alkalizing ion transporters. Acid-activated Na<sup>+</sup>/HCO<sub>3</sub><sup>- </sup>cotransport via pNBC1 expressed in renal cells is thus inhibited by cAMP and not affected by cholinergic stimulation, as opposed to the findings in native intestinal tissue. </p> <p>Conclusion</p> <p>Regulation of pNBC1 by secretagogues appears to be not solely dependent on its primary structure, but also on properties of the cell type in which it is expressed.</p
Familial neuralgia of occipital and intermedius nerves in a Chinese family
Cranial nerve neuralgia usually occurs sporadically. Nonetheless, familial cases of trigeminal neuralgia are not uncommon with a reported incidence of 1â2%, suggestive of an autosomal dominant inheritance. In contrast, familial occipital neuralgia is rarely reported with only one report in the literature. We present a Chinese family with five cases of occipital and nervus intermedius neuralgia alone or in combination in three generations. All persons afflicted with occipital neuralgia have suffered from paroxysmal âelectric waveâ-like pain for years. In the first generation, the father (index patient) was affected, in the second generation all his three daughters (with two sons spared) and in the third generation a daughterâs male offspring is affected. This familial pattern suggests an X-linked dominant or an autosomal dominant inheritance mode
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