Articles: manganese.
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Manganism is a central nervous system disorder caused by toxic exposure to manganese. Manganism has been related to occupational exposures, liver diseases, prolonged parenteral nutrition, and abuse of illicit drugs. Initially manifested by a reversible neuropsychiatric syndrome (locura manganica), the main symptoms and signs of manganism are emotional lability, compulsive behavior and visual hallucinations. Locura manganica is followed by an irreversible extrapyramidal syndrome, the onset of which occurs years after chronic exposure. ⋯ Prominent Mn depositions, evidenced by T1-weighted hyperintensities in the hippocampus after subacute exposure to Mn, are compatible with the clinical picture of manganism during its early stages, and may explain its pathophysiology.
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J. Cereb. Blood Flow Metab. · Apr 2008
Manganese-enhanced MRI of brain plasticity in relation to functional recovery after experimental stroke.
Restoration of function after stroke may be associated with structural remodeling of neuronal connections outside the infarcted area. However, the spatiotemporal profile of poststroke alterations in neuroanatomical connectivity in relation to functional recovery is still largely unknown. We performed in vivo magnetic resonance imaging (MRI)-based neuronal tract tracing with manganese in combination with immunohistochemical detection of the neuronal tracer wheat-germ agglutinin horseradish peroxidase (WGA-HRP), to assess changes in intra- and interhemispheric sensorimotor network connections from 2 to 10 weeks after unilateral stroke in rats. ⋯ Behaviorally, sensorimotor functions were initially disturbed but subsequently recovered and plateaued 17 days after stroke. This study shows that manganese-enhanced MRI can provide unique in vivo information on the spatiotemporal pattern of neuroanatomical plasticity after stroke. Our data suggest that the plateau stage of functional recovery is associated with restoration of ipsilateral sensorimotor pathways and enhanced interhemispheric connectivity.
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The aim of this study was to investigate latent manganese toxicity in patients with biliary atresia and to use this tool to predict the prognosis of biliary atresia patients after Kasai's portoenterostomy. ⋯ Although the study size is small, it shows that there is a risk of latent manganese toxicity in patients with biliary atresia who have undergone Kasai's portoenterostomy. Whole blood manganese assay in conjunction with brain MRI can be used to serially monitor these patients for early detection of these complications. This tool can be used for prognosis after Kasai's portoenterostomy and can also be extremely useful in selecting patients who will need a liver transplant on a priority basis.
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Gigiena i sanitariia · Jan 2007
[Manganese provision in trained and untrained schoolchildren and students in different seasons].
Examination of trained (43 skiers) and untrained senior schoolchildren (31 senior schoolchildren), low-order students-skiers (n = 110) and untrained (n = 17) students, high-order students-skiers (n = 39) and students not going in for sports (n = 60) established that in schoolchildren and students of both groups, the content of manganese in the blood plasma and corpuscles in the trained and untrained schoolchildren and students largely depended on the pattern of muscle activity rather than a season. In young skiers and high-order athletes, the level of manganese in both blood fractions was much higher almost at all stages of a follow-up, especially in the periods of increased training and race loads than that in the untrained persons of their age. ⋯ In almost all, manganese balance was negative in both winter and summer. The exception was untrained group of students in whom manganese balance was positive in winter due the higher dietary content of the trace than that in other groups.
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Sci. Total Environ. · Jul 2006
Manganese concentrations in the air of the Montreal (Canada) subway in relation to surface automobile traffic density.
Methylcyclopentadienyl manganese tricarbonyl (MMT) is an organic derivative of manganese (Mn), used since 1976 in Canadian gasoline as an octane enhancer. Its combustion leads to the emission of Mn particles. Several studies carried out by our research group have established a correlation between atmospheric Mn concentrations and automobile traffic density, suggesting that MMT in gasoline could play a significant role. ⋯ For the other two stations, the average concentrations of MnR were twice as high and exceeded the US EPA reference concentration of 0.05 microg/m(3). Although there may be several sources of Mn from different components of the subway structure and vehicles, no correlation was found between subway traffic and atmospheric Mn in the subway. Since the air in the underground subway is pumped directly from outside without filtration, our findings strongly suggest that the combustion of MMT in automobiles is an important factor.