No abstract

Free radical action has been suggested as a causal factor in multiple sclerosis. We investigated the plasma level of lipid peroxides expressed in terms of malone dialdehyde and changes in blood nonenzymatic antioxidants (glutathione, alpha-tocopherol, retinol, plasma sulfhydryl groups, and uric acid) in multiple sclerosis patients with exacerbation or in remission, including a group treated with beta-interferon. The malone dialdehyde level was increased by 38% (n.s.) during exacerbations. The blood concentration of oxidized glutathione was likewise elevated (P<0.05), while the ratio of plasma alpha-tocopherol to cholesterol plus triglyceride was decreased (P<0.001). These changes suggest increased free radical production and consumption of the scavenger molecules during the active phase of the disease. Blood reduced glutathione level was increased (P<0.01) during exacerbation and remission as well. The rise in this thiol is likely to be a compensatory mechanism defending the cells from further oxidant injuries. Beta-interferon increased plasma alpha-tocopherol levels (P<0.001) but not the lipid corrected alpha-tocopherol value. Other parameters were not influenced by the drug.

Many patients with multiple sclerosis (MS) show cognitive and emotional disorders. The purpose of this study is to evaluate the role of contingency learning in decision-making in young, non-depressed, highly functioning patients with MS (n 5 21) and in matched healthy controls (n 5 30). Executive functions, attention, short-term memory, speed of information processing, and selection and retrieval of linguistic material were also investigated. Contingency learning based on the cumulative effect of reward and punishment was assessed using the Iowa Gambling Test (IGT). In the classic ABCD version of the IGT, advantageous decks are characterized by immediate small reward but even smaller future punishment. In the modified EFGH version, advantageous decks are characterized by immediate large punishment but even larger future reward. Results revealed that patients with MS showed significant dysfunctions in both versions of the IGT. Performances on neuropsychological tests sensitive to dorsolateral prefrontal functions did not predict and did not correlate with the IGT scores. These results suggest that patients with MS show impaired performances on tasks designed to assess decision-making in a situation requiring the evaluation of long-term outcomes regardless of gain or loss, and that this deficit is not a pure consequence of

Tryptophan and its metabolites are of great interest in understanding the pathogenesis of multiple sclerosis (MS). The total levels of tryptophan and its metabolites, kynurenine and kynurenic acid were determined in plasma by capillary liquid chromatography electrospray ionisation tandem mass spectrometry. This is the first report of the plasma levels of these analytes in healthy controls and relapsing-remitting MS patients receiving long-term and acute interferon-beta (IFN-beta) treatment. Twenty-four hours post-administration increased kynurenine levels (first IFN MS versus healthy, P = 0.042) and kynurenine/tryptophan ratio (K/T; first IFN MS versus healthy, P =0.027; first IFN MS versus long-term IFN MS, P = 0.036) were found. The long-term IFN MS group had higher K/T ratios at 4 and 12 h post-administration (P = 0.015 and 0.009, respectively). The increase of K/T ratio in the first IFN MS group indicate an induction of the enzyme indolamine-2,3-dioxygenase (IDO), as reported earlier in experimental allergic encephalomyelitis. As IDO is participating in both inflammatory and neurodegenerative processes, further knowledge of its involvement in the pathogenesis of MS is of great importance.

Familial factors do not significantly affect eventual disease severity. However, they increase the probability of a progressive clinical course, either from onset or after a phase of relapsing remitting disease. The familial effect is more likely to reflect genetic than environmental conditions. The results are relevant for counseling patients and have implications for the design of studies seeking to identify factors that influence the natural history of the disease.