A 56-year-old man developed infiltrated erythemas on the trunk, extremities, and face with marked facial edema, one month after taking mexiletine hydrochloride for his arrhythmia. A number of pustules were also noted on the surface of erythemas on his chest and face. Laboratory examination showed liver dysfunction and hypereosinophilia. The culture from pustules was sterile. Histological examination of the biopsied skin from a pustular lesion revealed a subcorneal abscess, and perivascular infiltration of lymphocytes, mononuclear cells and eosinophils in the upper dermis. The skin lesions and facial edema as well were improved within three weeks by withdrawal of mexiletine hydrochloride. Patch tests with 10% and 20% mexiletine hydrochloride in petrolatum showed positive reaction, however, pustules were not provoked on the tested site. We conclude that pustules, infiltrated erythema and facial edema were the signs of acute exanthematous pustular drug eruption induced by mexiletine hydrochloride.

Acute Disease↗

PubMedDate not supplied

Validation of the mouse peripheral blood micronucleus assay using acridine orange supravital staining with urethane.

The mouse peripheral blood micronucleus assay using acridine orange supravital staining was compared with the standard bone marrow assay using urethane (ethyl carbamate)-treated mice. Urethane was intraperitoneally injected to CD-1 and BDF1 mice at doses ranging from 62 to 1000 and 62 to 250 mg/kg, respectively. Peripheral blood was collected from the tail 0, 24, 48, and 72 h and bone marrow cells were smeared at 24 and 42 h after the treatment. Although the response of micronucleus induction in peripheral reticulocytes was delayed by about 24 h compared to that in bone marrow polychromatic erythrocytes, the maximum frequencies of micronucleated young erythrocytes were comparable. Therefore, the peripheral blood micronucleus assay using the acridine orange supravital staining method may provide a good alternative to the conventional bone marrow assay.

Acridine Orange↗

PubMedDate not supplied

Reversible MR findings of hemolytic uremic syndrome with mild encephalopathy.

We report the reversible MR findings in a 7-year-old girl with hemolytic uremic syndrome and mild encephalopathy. The splenium of the corpus callosum showed isointense to low signal intensity on T1-weighted images and high signal intensity on T2-weighted images, representing local edema. These findings returned to near normal on MR images obtained 1 week later. The patient recovered without CNS impairment.

Brain↗