234 research outputs found

    Creutzfeldt-Jakob disease and homocysteine levels in plasma and cerebrospinal fluid

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    Background: There is evidence that homocysteine contributes to various neurodegenerative disorders. Objective: To assess the values of homocysteine in patients with Creutzfeldt-Jakob disease (CJD) in both cerebrospinal fluid (CSF) and plasma. Methods: Study design: Case control study. Total homocysteine was quantified in CSF and plasma samples of CJD patients (n = 13) and healthy controls (n = 13). Results: Mean values in healthy controls: 0.15 mumol/l +/- 0.07 (CSF) and 9.10 mumol/l +/- 2.99 (plasma); mean values in CJD patients: 0.13 mumol/l +/- 0.03 (CSF) and 9.22 mumol/l +/- 1.81 (plasma). No significant differences between CJD patients and controls were observed (Mann-Whitney U, p > 0.05). Conclusions: The results indicate that the CSF and plasma of CJD patients showed no higher endogenous levels of homocysteine as compared to normal healthy controls. These findings provide no evidence for an additional role of homocysteine in the pathogenetic mechanisms underlying CJD neurodegeneration. Copyright (C) 2005 S. Karger AG, Basel

    Confirmation That MAT1A p.Ala259Val Mutation Causes Autosomal Dominant Hypermethioninemia

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    Methionine adenosyltransferase (MAT) I/III deficiency is an inborn error of metabolism caused by mutations in MAT1A, encoding the catalytic subunit of MAT responsible for the synthesis of S-adenosylmethionine, and is characterized by persistent hypermethioninemia. While historically considered a recessive disorder, a milder autosomal dominant form of MAT I/III deficiency occurs, though only the most common mutation p.Arg264His has ample evidence to prove dominant inheritance. We report a case of hypermethioninemia caused by the p.Ala259Val substitution and provide evidence of autosomal dominant inheritance by showing both maternal inheritance of the mutation and concomitant hypermethioninemia. The p.Ala259Val mutation falls in the dimer interface, and thus likely leads to dominant inheritance by a similar mechanism to that described in the previously reported dominant negative mutation, that is, by means of interference with subunits encoded by the wild-type allele

    Spatial and temporal distribution of vertical ground movements at Mt. Vesuvius in the period 1973-2009

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    Since the early ’70s vertical ground movements at Mount Vesuvius area have been investigated and monitored by the Osservatorio Vesuviano (Istituto Nazionale di Geofisica Vulcanologia - Osservatorio Vesuviano since 2001). This monitoring began with the installation of a high-precision leveling line in the region at medium-high elevations on the volcano. The deformation pattern and expected strain field assessment methods in the volcanic structure induced by inner sources has demanded in subsequent years the expansion of the leveling network up to cover the whole volcanic area, enclosing part of leveling lines of other institutions. As a result of this expansion, the Mt. Vesuvius Area Leveling Network (VALN) has today reached a length of about 270 km and consists of 359 benchmarks. It is configured in 21 circuits and is connected, westward, to the Campi Flegrei leveling network and, northward, to the Campania Plain leveling network. The data collected have been carefully re-analyzed for random and systematic errors and for error propagation along the leveling lines to identify the areas affected by significant ground movements. For each survey, the data were rigorously adjusted and vertical ground movements were evaluated by differentiating the heights calculated by the various measurements conducted by the Osservatorio Vesuviano from 1973 to 2009

    Generalized Arcsine Law and Stable Law in an Infinite Measure Dynamical System

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    Limit theorems for the time average of some observation functions in an infinite measure dynamical system are studied. It is known that intermittent phenomena, such as the Rayleigh-Benard convection and Belousov-Zhabotinsky reaction, are described by infinite measure dynamical systems.We show that the time average of the observation function which is not the L1(m)L^1(m) function, whose average with respect to the invariant measure mm is finite, converges to the generalized arcsine distribution. This result leads to the novel view that the correlation function is intrinsically random and does not decay. Moreover, it is also numerically shown that the time average of the observation function converges to the stable distribution when the observation function has the infinite mean.Comment: 8 pages, 8 figure

    Impact of the MTHFR C677T polymorphism on one-carbon metabolites: Evidence from a randomised trial of riboflavin supplementation

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    Homozygosity for the C677T polymorphism in MTHFR (TT genotype) is associated with a 24–87% increased risk of hypertension. Blood pressure (BP) lowering was previously reported in adults with the TT genotype, in response to supplementation with the MTHFR cofactor, riboflavin. Whether the BP phenotype associated with the polymorphism is related to perturbed one-carbon metabolism is unknown. This study investigated one-carbon metabolites and their responsiveness to riboflavin in adults with the TT genotype. Plasma samples from adults (n 115) screened for the MTHFR genotype, who previously participated in RCTs to lower BP, were analysed for methionine, S-adenosylmethionine (SAM), S-adenosylhomocysteine (SAH), betaine, choline and cystathionine by liquid chromatography tandem mass spectrometry (LC-MS/MS). The one-carbon metabolite response to riboflavin (1.6 mg/d; n 24) or placebo (n 23) for 16 weeks in adults with the TT genotype was also investigated. Plasma SAM (74.7 ± 21.0 vs 85.2 ± 22.6 nmol/L, P = 0.013) and SAM:SAH ratio (1.66 ± 0.55 vs 1.85 ± 0.51, P = 0.043) were lower and plasma homocysteine was higher (P = 0.043) in TT, compared to CC individuals. In response to riboflavin, SAM (P = 0.008) and cystathionine (P = 0.045) concentrations increased, with no responses in other one-carbon metabolites observed. These findings confirm perturbed one-carbon metabolism in individuals with the MTHFR 677TT genotype, and for the first time demonstrate that SAM, and cystathionine, increase in response to riboflavin supplementation in this genotype group. The genotype-specific, one-carbon metabolite responses to riboflavin intervention observed could offer some insight into the role of this gene-nutrient interaction in blood pressure

    Regulation of 5-methyltetrahydrofolate synthesis

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    S-adenosylmethionine and S-adenosylhomocysteine levels in the aging brain of APP/PS1 Alzheimer mice

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    Hyperhomocysteinemia and factors of homocysteine metabolism, S-adenosylhomocysteine (AdoHcy) and S-adenosylmethionine (AdoMet), may play a role in Alzheimer’s disease (AD). With liquid-chromatography-tandem-mass-spectrometry AdoMet and AdoHcy were determined in brains of 8- and 15-month-old APP/PS1 Alzheimer mice, and their possible roles in AD brains investigated. The finding that AdoMet levels do not differ between the genotypes in (young) 8-month-old mice, but are different in (older) 15-month-old APP/PS1 mice compared to their wild-type littermates, suggests that alterations in AdoMet are a consequence of AD pathology rather than a cause. During aging, AdoMet levels decreased in the brains of wild-type mice, whereas AdoHcy levels diminished in both wild type and APP/PS1 mice. The finding that AdoMet levels in APP/PS1 mice are not decreased during aging (in contrast to wild-type mice), is probably related to less demand due to neurodegeneration. No effect of the omega-3 fatty acid docosahexaenoic acid (DHA) or cholesterol-enriched diets on AdoMet or AdoHcy levels were found

    Fascitis necrotizante, cuando el tiempo vale oro

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    La Fascitis Necrotizante es una infección de partes blandas que puede provocar una rápida destrucción del tejido afectado con necrosis y sepsis grave, potencialmente mortal. Los factores predisponentes son diabetes, neoplasias, alcoholismo, enfermedad hepática y renal crónica, entre otras. Es una urgencia médica que requiere un tratamiento quirúrgico precoz, y terapia antibiótica endovenosa de amplio espectro con el fin de disminuir la tasa de mortalidad. Presentamos el caso de un paciente con antecedente de linfoma T hepático que presentó fascitis necrotizante en el miembro inferior izquierdo secundario a Bacillus Cereus
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