Amiodarone-associated hemoptysis.

The manifestations of amiodarone pulmonary toxicity (APT) are generally nonspecific, and a diagnosis requires appropriate clinical history, laboratory testing consistent with toxicity, and exclusion of other disease entities. To our knowledge, hemoptysis associated with APT has not been described before; the following report describes such a case. We suggest that APT should be considered among the differential diagnosis of hemoptysis in a patient receiving amiodarone.

Comparison of the Raja and the Abrams pleural biopsy needles in patients with pleural effusion.

In 31 patients with exudative pleural effusions, we compared the diagnostic yield of the Abrams pleural biopsy needle with that of a new instrument, the Raja pleural biopsy needle. Each patient was randomly biopsied with both needles, and a total of 153 pleural biopsies were done, 73 with the Abrams needle and 80 with the Raja needle. No complications resulted from biopsies with either needle. Etiologic diagnoses were possible in 38 (52%) biopsies obtained using the Abrams needle, compared with 66 (82.5%) for those using the Raja needle; the difference in proportions for the diagnostic yield was statistically significant (p < 0.01, two-tailed Fisher's exact test). There were no significant differences between the needles in obtaining etiologic diagnoses in any specific disease category. The difference between the mean size of the pleural specimens obtained with the two needles was also statistically significant (p < 0.001, Mann-Whitney U test). The Raja pleural biopsy needle is easy and safe to use, and despite its smaller external diameter yields a significantly larger pleural tissue sample and significantly increases the diagnostic yield of pleural biopsies compared with the Abrams pleural biopsy needle.

Intrinsic positive end-expiratory pressure in ambulatory patients with airways obstruction.

In patients with severe expiratory airflow limitation, dynamic hyperinflation often occurs when inspiratory efforts are initiated at a thoracic volume above the relaxation point of the respiratory system. The result is intrinsic positive end-expiratory alveolar pressure (PEEPi). To determine whether PEEPi occurs in ambulatory patients, we measured alveolar pressure (Palv) noninvasively during tidal breathing in 8 normal subjects, 15 asthmatic subjects, and 19 patients with COPD, using a body plethysmographic technique that includes computerized corrections for nonlinear pneumotachometer output and for plethysmograph leakage. In all 8 normal subjects, 9 asthmatic subjects, and 3 COPD patients, Palv descended smoothly to zero at end expiration. In contrast, among each of the remaining 22 patients, there was an abrupt change in slope of the Palv tracing near end expiration, identifying the onset of the next inspiratory effort and indicating the presence of PEEPi, ranging from 0.2 to 9.5 cm H2O. PEEPi was significantly correlated with FRC (% of predicted); PEEPi = (0.040 x %FRC) - 3.65, r = 0.73, p < 0.001, and with the reciprocal of FEV1 (% of predicted), PEEPi = (138/%FEV1) - 1.34, r = 0.69, p < 0.001. PEEPi could be elicited in normal subjects by severe expiratory resistive loading but not by the increased expiratory muscle activity occurring during an MVV maneuver. We conclude that PEEPi is common in patients with airways obstruction, even without overt ventilatory failure, and that its severity is generally in proportion to the severity of the hyperinflation and the airways obstruction.

Synthesis of the antibacterial peptide cecropin A (1-33).

Cecropin A(1-33) was synthesized by an improved stepwise solid-phase method. The synthesis was designed to give high coupling yields and minimal amounts of byproducts. All coupling steps were monitored for completion by a new ninhydrin procedure, and the fully protected peptide-resin was analyzed for deletion peptides by the solid-phase Edman preview technique. Both methods indicated that the average coupling yield was greater than 99.8%. The unpurified peptide mixture resulting from HF cleavage and extraction into 10% acetic acid was analyzed by reverse-phase high-pressure liquid chromatography, and 93% of the total product was shown to be the desired [Trp(For)2]cecropin A(1-33), indicating an average yield per synthetic cycle of 99.8%. Removal of the formyl group at pH 9, followed by ion-exchange chromatography, gave the purified product. Cecropin A(1-33) showed antibacterial activity against both Gram-positive and Gram-negative bacteria. Against Escherichia coli, the activity was only slightly lower than that of the natural 37-residue cecropin A when tested over a 100-fold concentration range; the minimum inhibitory concentration was approximately 1 microM. The formyl derivative was somewhat less effective in killing E. coli than the free 1-33 peptide. The antibacterial activity was discussed in terms of an amphipathic alpha-helix structure and the binding of the peptide to bacterial membranes.