Flexible transbronchial needle aspiration in the diagnosis of sarcoidosis.

The histopathologic diagnosis of sarcoidosis requires the presence of noncaseating granulomas. Transbronchoscopic lung biopsy (TBLB) has been considered the procedure of choice when less invasive tissue samples are unavailable. A total of 51 consecutive patients suspected of having sarcoidosis underwent combined TBLB and flexible transbronchial needle aspirate (TBNA). In 18 of the 30 patients (60 percent) with stage I disease, the diagnosis was confirmed by TBLB and 16 (53 percent) were confirmed by TBNA. The combined use of both procedures increased the diagnostic yield to 83 percent. The remaining 21 patients with stage II disease had their diagnosis confirmed in 16 (76 percent) cases by TBLB and 10 (48 percent) by TBNA with a combined diagnostic yield of 86 percent. Seven (23 percent) patients with stage I disease and 2 (10 percent) with stage II disease had their conditions diagnosed by TBNA. We conclude that combining TBNA with TBLB increases the diagnostic yield in pulmonary sarcoidosis; TBNA should complement TBLB in the diagnosis of this disease.

Buthionine sulfoximine treatment impairs rat diaphragm function.

Activation of the glutathione (GSH) redox cycle with production of glutathione disulfide (GSSG) has been shown to occur in the diaphragm during inspiratory resistive loading (RB). Buthionine sulfoximine (BSO) lowers tissue GSH by irreversibly inhibiting the rate-limiting synthesis enzyme gamma-glutamylcysteine synthetase. We investigated the effects of BSO on rat diaphragm function, both at rest and after a period of RB. Rats in the RB groups underwent inspiratory RB until they were unable to sustain 70% of their maximal airway pressure. A portion of the diaphragm was analyzed for GSH and GSSG levels, and measurements of in vitro contractile properties included contraction times, maximal tetanic tension (Po), maximal twitch tension (Pt), and force frequency curves. BSO treatment produced a profound depletion of diaphragmatic GSH. Neither BSO nor RB alone significantly altered diaphragm contractile properties at this load of RB. But, in BSO-RB rats, there was a significant decrease in Pt, Po, and tetanic tension at all frequencies of stimulation compared with those in other groups. These data reveal that animals treated with BSO followed by inspiratory resistive loading exhibit marked diaphragm impairment, suggesting that GSH may play an important role in protecting the diaphragm from the stress induced by this resistive breathing protocol.

Diethylmaleate produces diaphragmatic impairment after resistive breathing.

Formation of oxygen-derived free radicals and activation of the glutathione (GSH) redox cycle has been associated with impaired rat diaphragm performance. Diethylmaleate (DEM) given intraperitoneally irreversibly conjugates with GSH, resulting in marked decreases in tissue concentrations of GSH. We have investigated the effects of acute GSH depletion by DEM on diaphragmatic function during resistive breathing (RB) in the rat. The experimental groups were 1) control, 2) DEM alone, 3) RB, and 4) DEM with RB (DEM + RB). RB was obtained by inspiratory RB until the rats were unable to sustain 70% of maximum airway opening pressure. A portion of the diaphragm was frozen for biochemical assays, and the rest of the diaphragm was prepared for measurement of in vitro contractile properties, including maximum tetanic tension, twitch tension, force-frequency curves, and contraction times. DEM treatment produced a profound depletion of GSH in the DEM and DEM + RB groups. Neither DEM nor RB alone significantly altered diaphragm contractile properties. In DEM + RB rats, however, there was a significant decrease in maximum tetanic tension, twitch tension, and tetanic tension. These data reveal that DEM produced an acute depletion of GSH in the diaphragm without impairment of the muscle in nonstressed rats. In the presence of DEM-induced GSH depletion, RB did result in marked diaphragm impairment. The depletion of GSH and the subsequent impairment in diaphragm contractility after RB suggest that GSH may play an important role in protecting the diaphragm against oxidative stress associated with RB.

Noncardiogenic pulmonary edema associated with accidental hypothermia.

The pulmonary system may be significantly affected by hypothermia. The association between NCPE and hypothermia is controversial. A 59-year-old man with mild hypothermia presented with NCPE after passive external rewarming following accidental immersion in water. The patient's course was uneventful after 48 h, allowing immediate withdrawal of assisted ventilation and supplemental oxygen.