No abstract

Uric acid has neuroprotective properties in experimental and clinical studies of neurodegenerative disease. It is, however, associated with increased risk of stroke, yet, despite some inconsistent findings, increasing evidence suggests it may also be related to improved stroke outcomes. We have determined whether there is an effect of plasma uric acid on the short-term outcome of stroke patients in a general hospital setting using the modified Rankin Scale (mRS). We also investigated the relationship of uric acid with other clinical correlates. Plasma uric acid was determined in 108 acute ischemic stroke patients and their mRS scores measured. Patients with a poor outcome (mRS > 2) had significantly lower uric acid than those with a better outcome; this remained after correcting for the effect of sex on uric acid concentrations. There was no significant association with other epidemiological factors or with cognitive function determined by Mini-Mental State Examination. An association between uric acid and the cerebral circulation was also found in which lower uric acid occurs with posterior artery involvement. These findings demonstrate in a naturalistic cohort of patients the association of uric acid with short-term disability following ischemic stroke. They also raise the question of whether uric acid may influence the regional brain involvement in stroke.

No abstract

Background: Exposure to environmental neurotoxins associated with agricultural work, such as pesticides, may be a risk factor for neurodegenerative disorders such as Alzheimer’s (AD) and Parkinson’s (PD) diseases. There is strong evidence that such exposure is associated with the development of PD; for AD the current evidence is equivocal. Several mechanisms are proposed to mediate this environmental toxicity, one of which is oxidative stress. Uric acid (UA) is an endogenous antioxidant, low levels of which are also implicated in neurodegenerative disease. Objective: This study aimed to determine whether agricultural work was a risk factor for AD in a population in which its association with PD was established, and whether UA was also associated with AD in this cohort. Methods: Hospital records of subjects meeting criteria for AD (n = 128) or vascular dementia (VaD) (n = 178) after hospital admission for symptoms of dementia were studied. History of agricultural work and plasma UA were recorded and their relationship to diagnosis determined. Results: In contrast to previous findings in this population in which agricultural work was strongly associated with PD, a history of agricultural work was not over-represented in hospital admission for AD versus VaD. AD was associated with a reduced level of circulating UA compared with VaD. Conclusion: Agricultural work as a likely proxy for exposure to pesticides appears not to be a risk factor for AD to the extent found in PD, perhaps reflecting their differences in neuronal pathology. Nevertheless, findings with UA suggests that oxidative stress may be an important factor in AD pathogenesis.

Monoamine oxidase type B inhibitors act in Parkinson's disease (PD) via potentiation of dopamine, but may also have neuroprotective effects by reducing oxidative damage. Oxidative damage is also a feature of environmental toxins, including pesticides, that are an established risk factor for PD. Another risk factor is low circulating uric acid (UA), which may relate to UA being the major endogenous antioxidant in the human body. We have undertaken a study of 192 initial admissions for PD in a general hospital neurology department in a partly rural region of Southern China to determine if there is an increased rate of PD in agricultural workers who have a high risk of exposure to pesticides, and how it may relate to deficits in UA. We found a disproportionately high number of agricultural workers admitted with PD (66.7% vs. 54.3% of all neurology admissions) and that PD subjects have a substantial reduction in UA. This is further reduced in agricultural workers and thus may contribute to the increased vulnerability of this group to PD.

No abstract

No abstract