Characteristics of myasthenia gravis according to onset-age: Japanese nationwide survey.

OBJECTIVE: To clarify the prevalence and clinical characteristics of myasthenia gravis (MG) in Japan. METHODS: We performed a nationwide epidemiological survey of MG in Japan. The clinical features were compared among five groups of patients, divided according to onset age. A generalized additive model (GAM) was used to assess the linearity of these relationships. RESULTS: A total of 8542 patients were reported, and detailed data were analyzed for 3141 patients. The estimated number of MG patients in Japan was 15,100, giving a prevalence of 11.8 per 100,000. Elderly-onset MG (≥ 65 years) accounted for 7.3% in 1987 (adjusted for population in 2005), but this had increased to 16.8% in 2006. Infantile-onset MG (0-4 years) accounted for 10.1% in 1987, and was still as high as 7.0% in 2006. The rate of ocular MG was highest (80.6%) in infantile-onset and lowest (26.4%) in early-onset disease, but the rate rose again in the late-onset group. GAM analysis of the ocular form showed a U-shaped curve, with a dip in the 20s. Anti-acetylcholine receptor antibodies were positive in only 50% of infantile-onset, but nearly 90% of elderly-onset patients. GAM analyses assessing the concurrence of thymoma and hyperplasia both showed reversed U-shapes, with peaks in the 50s and 20s-40s, respectively. CONCLUSIONS: Persistent high incidence of infantile-onset disease and clinical heterogeneity according to onset age are characteristic features of MG in Japan.

Relationship between alcohol habits and hemorheology by a micro channel method in a general population.

BACKGROUND: Hemorheology plays an important role in the development of cardiovascular disease. The Micro Channel array Flow Analyzer (MC-FAN) (Hitachi Haramachi Electronics Co., Ltd., Bentencho, Japan) is currently considered a useful new device to analyze hemorheology. However, the relationships between various lifestyle habits and hemorheology, especially using MC-FAN, have still not been thoroughly investigated. HYPOTHESIS: The study was undertaken to determine whether there could be some correlations of lifestyle factors to hemorheology by MC-FAN. METHODS: A total of 250 asymptomatic Japanese subjects (male:female = 100:150; mean age = 49.7 y) without any medication were enrolled in the present study. Hemorheology was assessed by the whole blood passage time (WBPT) and was corrected by the saline passage time using MC-FAN. Subjects' lifestyle factors, such as smoking habits, alcohol habits, and physical activity, were self-reported. RESULTS: Partial correlation analysis for WBPT, after controlling for age, gender, hematocrit, white blood cell count, body mass index, blood pressure, blood biochemical measures, and all lifestyle habits, revealed a significant and inverse correlation between alcohol habits of 1-3 go (amount of alcohol intake) and WBPT (r = - 0.191, p = 0.003), in addition to a significant positive correlation between serum low-density lipoprotein (LDL) cholesterol and WBPT. CONCLUSIONS: These data suggest that alcohol habits may beneficially affect hemorheology by MC-FAN, expanding the protective effect of light-to-moderate alcohol consumption against cardiovascular disease.

[Congenital myasthenic syndrome].

Congenital myasthenic syndromes (CMS) are rare heterogeneous disorders in which neuromuscular transmission is compromised by one or more specific mechanisms. CMS are clinically diagnosed by a history of fatigability and muscle weakness since infancy or early childhood, a decremental EMG response and the absence of acetylcholine receptor antibodies. CMS form a heterogeneous group of disorders which are classified as originating from presynaptic, synaptic or postsynaptic defects. Molecular genetic studies reveal a various type of mutations in synapse-associated genes. However, the genetic abnormalities of many CMS are still unresolved. This article outlines the classification of CMS and etiology of individual forms.

Myasthenia gravis with thymus hyperplasia and pure red cell aplasia.

A case of myasthenia gravis (MG) with thymus hyperplasia and pure red cell aplasia (PRCA) is reported. A 57-year-old woman was diagnosed as having MG and was treated with thymectomy 26 years ago. The histology of the resected thymus was thymic lymphoid follicular hyperplasia. She developed rapidly progressive anemia and a bone marrow examination revealed PRCA. Her hematological results improved with oral administration of cyclosporine A. Cases of MG, thymoma and PRCA have been reported in the literature. We report the first case of MG without thymoma and PRCA.

Transcriptional activation of p62/A170/ZIP during the formation of the aggregates: possible mechanisms and the role in Lewy body formation in Parkinson's disease.

Formation of intracellular inclusion bodies due to defects in the protein degradation machinery is associated with the pathogenesis of neurodegenerative diseases. Sequestosomal protein p62/A170/ZIP, which is an oxidative stress-related protein and a ubiquitin-binding protein, is a component protein of Lewy bodies that are observed in patients with Parkinson's disease. The association of p62 with poly-ubiquitinated proteins may be an important step in the formation of intracellular protein aggregates like Lewy bodies. To study the role of p62 in the formation of protein aggregates in PC12 cells, we monitored the intracellular localizations of p62 and ubiquitinated proteins and the levels of both components during treatment with MG132, a proteasome inhibitor. In the early stage of aggregate formation, p62 did not always co-localize with ubiquitin. In contrast, these proteins were always co-localized in later stages. After the treatment of the cells with MG132, we found that the expression level of p62 increased due to the transcriptional activation of the gene and that higher molecular sizes of p62, corresponding to mono- and di-ubiquitinated formes, were also formed. Both the transcriptional inhibitor actinomycin D and an antisense oligonucleotide of p62 inhibited the MG132-mediated increase of p62, the sequestration of ubiquitinated proteins, and the enlargement of the aggregates. Furthermore, p62-positive aggregates were observed primarily in surviving cells. Together, these results suggest that p62 plays an important role in the protection of cells from the toxicity of misfolded proteins by enhancing aggregate formation especially in the later stages.