We investigated the paraclinical profile of monosymptomatic optic neuritis (ON) and its prognosis for multiple sclerosis (MS). The correct identification of patients with very early MS carrying a high risk for conversion to clinically definite MS is important when new treatments are emerging that hopefully will prevent or at least delay future MS. We conducted a prospective single observer and population-based study of 147 consecutive patients (118 women, 80%) with acute monosymptomatic ON referred from a catchment area of 1.6 million inhabitants between January 1, 1990 and December 31, 1995. Of 116 patients examined with brain MRI, 64 (55%) had three or more high signal lesions, 11 (9%) had one to two high signal lesions, and 41 (35%) had a normal brain MRI. Among 143 patients examined, oligoclonal IgG (OB) bands in CSF only were demonstrated in 103 patients (72%). Of 146 patients analyzed, 68 (47%) carried the DR15,DQ6,Dw2 haplotype. During the study period, 53 patients (36%) developed clinically definite MS. The presence of three or more MS-like MRI lesions as well as the presence of OB were strongly associated with the development of MS (p < 0.001). Also, Dw2 phenotype was related to the development of MS (p = 0.046). MRI and CSF studies in patients with ON give clinically important information regarding the risk for future MS.

Role boundary and role insufficiency were the factors that had the highest association with occupational stress. Occupational health education and occupational training programmes may be necessary to improve the knowledge and ability of nurses to cope with job demands and reduce occupational stress.

BackgroundWe report the concentrations and distributions of urinary arsenic (As) metabolites in 233 residents exposed to 20, 90, or 160 μg/L inorganic arsenic (iAs) in drinking water from three villages in Hohhot, Inner Mongolia, China, that formed one control and two exposed groups.MethodsWe used hydride generation-atomic absorption spectrometry (HGAAS) to determine iAs, monomethylarsonic acid (MMA), and dimethylarsinic acid (DMA).ResultsThe concentrations of each urinary As species in the two exposed groups were significantly higher than in the control group for both children and adults. Both children and adults in exposed groups had higher percent iAs and MMA and lower percent DMA, and low primary and secondary methylation indices (PMI and SMI, respectively) than those in the control group. However, children showed significant increases in percent DMA and the SMI as well as decreases in the percent MMA when the iAs exposure level increased from 90 to 160 μg/L. In addition, children in the two exposed groups showed lower percent MMA but higher percent DMA and higher SMI than adults in the same exposed group. No significant differences in As metabolite concentrations and distributions were found between males and females in each group. A significant correlation was also found in the SMI between 11 pairs of children and their mothers from the 160-μg/L–exposed group.ConclusionsChildren had higher a capacity for secondary methylation of As than adults when exposed to the same concentrations of iAs in drinking water. Exposure to As may increase the capacity for methylation in children to some extent.

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