Relation between colour vision loss and occupational styrene exposure level.

AIMS: To investigate the relation between colour vision loss and the exposure level of styrene. Exposure level included the current exposure concentration, past cumulative exposure, and the maximum exposure level in the past. METHODS: Colour vision was examined by the Lanthony desaturated panel D-15 test for 76 subjects exposed to styrene in a fibreglass reinforced plastics boat plant (as an exposed group) and 102 non-exposed subjects (as a control group). The current exposure level was expressed by the concentration of atmospheric styrene and end shift urinary mandelic acid (MA) and phenylglyoxylic acid (PGA) levels. The individual cumulative exposure index (CEI) was calculated, based on the exposure frequency and urinary MA concentrations measured for the past eight years. RESULTS: The Colour Confusion Index (CCI) of the exposed group showed a significant difference from the age matched controls. However, only a slight significant relation was found between CCI and the concentration of urinary MA plus PGA. In this study, the exposed group was further divided into two subgroups (as sub-MA+PGA groups) by the median of urinary MA plus PGA of each subject. The dividing line between the subgroups was 0.24 g/g creatinine, which was equivalent to an atmospheric concentration of styrene of about 10 ppm. The CCI values of both the sub-MA+PGA groups were significantly higher than that of the control group. The relation between CCI value and the maximum exposure concentration in the past eight years was examined. It was found that the CCI values of the group with the maximum exposure concentration of styrene over 50 ppm were significantly higher than that of the other groups. CONCLUSIONS: Exposure to styrene would impair colour vision even if the exposure concentration was lower than 10 ppm. Furthermore, if the maximum concentration of styrene exposure transiently exceeded 50 ppm in the past, the styrene related damage might remain. Thus, the safe limit of exposure to styrene and the relation between exposure to styrene and the degree of damage to ocular structure, retina, optic nerve, and brain need to be re-examined.

Long-term blood pressure variability and cerebrovascular changes on CT in a community-based elderly population.

The effects of long-term blood pressure (BP) levels on cerebrovascular changes were analyzed in a community-based healthy elderly population. Cranial computed tomography (CT) was performed for 300 residents aged 69 years and older. Long-term BP during the ten years prior to CT was assessed, and the cerebrovascular changes were compared among different patterns of long-term blood pressure variability. White matter lesions (WML) and/or silent infarctions (SI) were found in 73 subjects (23.6%). Multiple logistic regression analysis showed that subjects with long-term diastolic hypertension (DHT) had the highest risk of cerebrovascular changes (adjusted odds ratio (OR), 95% confidence interval (CI); 7.1, 2.4-21.6, for WML; 7.2, 2.7-19.4, for SI), and that long-term isolated systolic hypertension (ISHT) was significantly associated with SI (adjusted OR, 95%CI, 2.3, 1.1-4.9), but not with WML (adjusted OR, 95%CI, 1.3, 0.5-3.3). Efforts to prevent both DHT and ISHT would be beneficial, though different underlying mechanisms for WML and SI were suggested.

Both the HLA-CPB1 and -DRB1 alleles correlate with risk for multiple sclerosis in Japanese: clinical phenotypes and gender as important factors.

The purpose of this study was to clarify the association of HLA-DRB1 and -DPB1 alleles with multiple sclerosis (MS) in Japanese, to determine whether optico-spinal MS (OS-MS) and conventional MS are immunogenetically distinct, and to verify the role of gender difference in HLA associations of MS. We studied HLA-DRB1 and -DPB1 polymorphisms in 166 Japanese patients with MS. Forty-seven patients were classified as having the optico-spinal MS (OS-MS) and 119 as having conventional MS. A lack of DPB1*0301 and a higher frequency of DPB1*0501 compared with controls (corrected P<0.0074; odds ratio=9.48) were found in OS-MS. By contrast, we found for the first time an association of DPB1*0301 with conventional MS in Japanese (corrected P=0.0444; odds ratio=3.28). Logistic analysis, adjusted for sex and age, revealed independent associations of DPB1*0301 (P=0.0004, adjusted odds ratio (aOR)=4.70), DPB1*0501 (P=0.0081, aOR= 2.50) and DRB1*1501 (P=0.0252, aOR=2.21) with conventional MS. However, the frequencies of DRB1*1501 and DPB1*0501 in male patients with conventional MS were equal to those in male controls while the DPB1*0301 frequency was increased in both male and female patients. We did not find any association of these HLA alleles with disease course and severity. In conclusion, OS-MS is a DPB1*0501-associated distinct subtype of MS, and DPB1*0301 is the most strongly associated allele with conventional MS in Japanese. In addition, gender plays an important role in HLA association with MS.

[A case of Sjögren syndrome associated with multiple mononeuritis and dysautonomia including bilateral tonic pupils].

Sjögren syndrome (SjS) is a glandular disease characterized by dry eyes and dry mouth. Extraglandular manifestations in SjS are also common, and peripheral nerve involvement has been reported in 10-20% of cases. We report a case of Sjögren syndrome with bilateral tonic pupils, dysautonomia, and multiple mononeuritis. The fact that sural nerve sections, in addition to marked loss of myelinated and unmyelinated fibers, showed an increased number of infiltrating macrophages without lymphocytes and aberrant expression of HLA-DR (class II) antigen in Schwann cells was an especially interesting finding. No evidence of active vasculitis was detected. The patient was treated with corticosteroids and her condition gradually improved, as confirmed by thermography. Our findings suggested the presence of specific immunological abnormalities simultaneously involving the ciliary ganglia, autonomic ganglia, and dorsal root ganglia in this peculiar form of SjS.

Neurological manifestations of primary Sjögren's syndrome in Japanese patients.

The neurological manifestations of twenty-one Japanese patients with Sjögren's syndrome (SjS) were evaluated. All patients were women, and sixteen of the twenty-one cases (76%) demonstrated objective abnormal neurological symptoms, the most frequently observed of which was trigeminal neuropathy (50%). Multiple mononeuropathy was seen in almost one-third of the examined cases (31%). Central nervous system (CNS) involvement was observed in three cases (14%). All of these values differed greatly from those previously reported. Therefore, this study revealed characteristic features of Japanese SjS and also implied the existence of different immunopathological mechanisms associated with SjS in Japanese patients.

Erdheim-Chester disease and slowly progressive cerebellar dysfunction.

A 59 year old woman developed pronounced thirst, increased water intake, and increased urinary output followed by slowly progressive cerebellar symptoms. Brain MRI showed abnormal hyperintensity on T2 weighted studies in the region of both dentate nuclei without atrophy of the cerebellum or the brainstem. A 99mTC diphosphonate bone scan showed bone lesions in the distal parts of both femurs as well as distal and proximal parts of both tibias. The diagnosis of Erdheim-Chester disease was made by bone biopsy. This is the first case of Erdheim-Chester disease presenting as a slowly progressive cerebellar syndrome and diabetes insipidus, and also showing high signal lesions in deep cerebellar nuclei on MRI. Skeletal surveys are indicated for patients with otherwise unexplained slowly progressive cerebellar symptoms.

Sequential magnetic resonance features of encephalopathy induced by systemic mastocytosis.

A 37-year-old man developed encephalopathy with prominent eosinophilia. Magnetic resonance imaging (MRI) revealed multiple T2-weighted high signal intensity lesions with dimeglumine gadopentetate (Gd-DTPA) enhancement on T1-weighted images, which were distributed in the cerebral cortex, thalamus, deep white matter and cerebellum. He was diagnosed as having systemic mastocytosis on the basis of proliferating mast cells in the bone marrow and peripheral eosinophilia. Following steroid administration, there was a rapid improvement of his symptoms and laboratory data. To our knowledge, this was the first reported case of systemic mastocytosis provoking encephalopathy with serial MRI findings.