[A case of Wegener's granulomatosis presenting as severe acute respiratory failure].

A 19-year-old man was admitted to another hospital. Pulmonary suppuration was diagnosed and was treated with antibiotics. However, he developed acute respiratory failure, which required intubation and ventilation with 100% oxygen. After treatment with nitric oxide inhalation and corticosteroid pulse therapy, the patient's condition stabilized and he gradually regained a satisfactory pulmonary function. He was discharged about 3 months after admission with a pulmonary function close to normal. Approximately 1 month later, the patient was admitted to our hospital because of a 2-week history of fever and chest and ocular pain. A chest radiograph obtained upon admission showed a nodule with a cavity in the upper lobe of the right lung. Pulmonary suppuration was again suspected, and antibiotics were given. The fever persisted and chest radiograph on hospital day 19 showed marked extension of the nodules. At that time, the patient complained of nasal obstruction and hoarseness and his sclera showed intense congestion, indicating episcleritis. Wegener's granulomatosis was diagnosed on the basis of the clinical picture, PR3-ANCA titer (63 EU) and nasal biopsy findings. After treatment with prednisolone and cyclophosphamide, his condition stabilized, and he recovered gradually. However, his condition remains poor despite continued therapy. This is an extremely rare case of Wegener's granulomatosis presenting as severe acute respiratory failure.

[A case of Swyer-James syndrome with interesting chest radiographs].

A 28-year-old man was admitted for further examination after overinflation of the right lung was observed on a screening chest radiograph. The chest radiograph on admission showed increased radiolucency of the left lung and overinflation of the right lung, associated with a shift of the mediastinum toward the midline on expiration. High-resolution CT on expiration showed air trapping in the left lung and in part of the right lower lobe. Pulmonary perfusion scintigraphy showed a markedly decreased perfusion in these areas. Pulmonary angiography revealed small left pulmonary arteries with diminished peripheral vascular branches. Bronchoscopy showed no abnormality of either bronchus. Swyer-James syndrome was diagnosed on the basis of these findings. Although bronchial damage due to the lower respiratory tract infection during childhood is considered a very important factor in the pathogenesis of this syndrome, many patients have no history of airway infection, as in this case. This is a rare case of Swyer-James syndrome presenting with marked overinflation of the unaffected lung in an asymptomatic adult. Progression of this compensative overinflation probably involved asymptomatic damage caused by the weakness of the affected lung.

Redistribution of ERK/MAP kinase to uropod-like structures in interleukin-3-induced cell shape changes.

Interleukin-3 (IL-3) is one of the cytokines of significance for the regulation of hematopoiesis and inflammation. Recently, we established IL-3-dependent Ba/F3 pro-B cells ectopically expressing RON tyrosine kinase, a receptor for macrophage-stimulating protein (MSP), and showed that MSP stimulation specifically promoted cell morphological changes through tyrosine phosphorylation of the IL-3 common beta-chain receptor subunit (betac) by activated RON kinase without activation of JAK2 tyrosine kinase. Here we investigate the IL-3 signaling pathway leading to morphological changes through tyrosine phosphorylation of betac. Treatment of RON-expressing cells with PD98059 or U0126, inhibitors of mitogen-activated protein kinase kinase activity, blocked both IL-3- and MSP-induced morphological changes. Upon stimulation with IL-3 or MSP, extracellular-regulated kinase (ERK) and F-actin were redistributed in uropod-like structures. ERK and F-actin were colocalized within uropod-like structures, and a majority of F-actin were localized around the peripheries of accumulated ERK. Tyrosine phosphorylation of ERK was detected after stimulation with IL-3 or MSP, whereas treatment with U0126 specifically inhibited IL-3- or MSP-induced ERK phosphorylation but not tyrosine phosphorylation of betac. These results suggest that the activation and localization of ERK to uropod-like structures play a role in IL-3-induced morphological changes.