[Clinical analysis of 11 cases of juvenile dermatomyositis and polymyositis].

Juvenile dermatomyositis (JDM) is characterized by microvasculopathy of the striated muscle, which indicates different etiology, clinical manifestation and prognosis from the adult-onset dermatomyositis. We experienced 10 cases of JDM and 1 case of juvenile polymyositis (JPM) in the recent 14 years, and analyzed clinical manifestation, laboratory findings, treatment anrognosis. The cases were 9 girls and 2 boys. The onset of the disease was 2 years of age in 2 patients, and 9 to 13 years of age in 9 patients. During the follow-up courses, no cases were dead or complicated with neoplasm. Skin rash was the most frequent manifestation at the onset, and facial erythema was common. Muscle weakness was observed only in 4 cases at the onset, and in all cases muscle enzymes including creatine kinase and aldolase were elevated. The clinical course was classified into three groups; monocyclic (5 cases), chronic and recurrent (4 cases), and fulminant (2 cases). Prognosis depended not on the degree of the elevated serum muscle enzymes, but on the initial therapy employed at the onset of the disease. Five cases including 2 cases of fulminant type were initially treated with methylprednisolon pulse therapy, and all of these had no recurrence. On the other hand, 6 cases were started the therapy with p.o. prednisolone. Four of them had frequent recurrences in accordance with tapering of prednisolone. These cases were effectively treated with the combination with immunosuppressants. In previous reports, JDM and JPM were reported to be a disorder which had relatively favorable prognosis. But we found that one third of the cases had chronic and recurrent courses. Methylprednisolone pulses as initial therapy may be effective in preventing the chronicity and recurrence of the disease.

Transformation of the acidophilic heterotroph Acidiphilium facilis by electroporation.

We constructed a cloning vector for use in the acidophilic heterotroph Acidiphilium facilis. The vector pAH101 (8.8 kb) was constructed from a 6.1 kb restriction fragment of the Acidiphilium plasmid pAH1 and a pUC19 carrying a beta-lactamase gene. The antibiotic resistance gene was efficiently expressed in A. facilis. Several factors which influenced the transformation efficiency were optimized, resulting in a transformation efficiency of up to 3 x 10(3) transformants per microgram of plasmid DNA at a field strength of 10 kV/cm with a 7.0 ms pulse.

The mechanism of contractile action of palytoxin on vascular smooth muscle of guinea-pig aorta.

The mode of action of palytoxin (PTX) on the contractile responses and ion movements in guinea-pig aorta was investigated. PTX (10(-8) M) induced a contraction with a latency period of 0.5-1 min, and it reached maximum after about 20 min. This contraction was not affected by phentolamine (10(-6) M). The contraction induced by PTX was rapidly abolished by removal of external Ca. Readdition of Ca restored the contraction. Verapamil, which markedly antagonized the contraction induced by some depolarizing agents (K, Ba and tetraethylammonium), decreased the rate of rise of the PTX-induced contraction, but did not affect the sustained tension level. Removal of external Na markedly inhibited the contraction induced by PTX (10(-10) - 10(-8) M), while it had no effect on the contraction induced by histamine (10(-7) - 10(-5) M). PTX rapidly decreased tissue K content with a similar time course to that of the increase in tension. Ouabain (10(-4) M) also caused contraction and decreased tissue K content in the muscle, but the rate of these changes was much slower than the PTX-induced ones. PTX increased cellular 45Ca content in normal solution, but not in Na deficient solution. These results suggest that the PTX-induced contraction in guinea-pig aorta is due to an increase in membrane Na permeability.