Monoclonal antibody characterization of a chymotrypsin-like molecule on neutrophil membrane associated with cellular activation.

Monoclonal antibody 1-15 (Ab 1-15), is a murine anti-human neutrophil (PMN) IgG1 that inhibits PMN effector responses to N-formyl-met-leu-phe (FMLP) and phorbol myristate acetate. In this study, the effects of Ab 1-15 on PMN membrane-related functions were characterized: Ab 1-15 inhibited PMN superoxide (O-2) response to FMLP by 60% (P less than 0.005) without effect on the onset or duration of O-2 production. This inhibition of O-2 response was associated with a significant inhibition of PMN chymotrypsin-like, but not trypsin-like, protease activity. Cell fractionation studies indicated the presence of an Ab 1-15 inhibitable, chymotryptic neutral protease activity in PMN membranes. In studies of Ab 1-15 effects on membrane-related second messenger pathways, Ab 1-15 augmented both FMLP- and isoproterenol-induced intracellular cAMP accumulation, whereas alpha-chymotrypsin decreased PMN cAMP response to these stimuli. Our data suggest that the function-inhibiting, anti-PMN monoclonal Ab 1-15 defines a PMN chymotryptic enzyme on the membrane surface that is involved in regulation of two membrane-related functions, O-2 generation and cAMP generation.

CT-guided cutting-needle biopsies of selected chest lesions.

In an effort to improve on our diagnostic yield from percutaneous transthoracic biopsy, we used 14-gauge cutting needles in 56 selected patients. These biopsies were preceded by 18-, 20-, or 22-gauge aspirations in 42 patients, allowing a direct comparison of the efficacy of the needle types. Specific diagnoses were made by cutting-needle biopsy in 78% (25/32) of patients with nonlymphoproliferative malignancies, in 73% (8/11) with lymphoma or thymoma, and in 54% (7/13) of patients with benign diseases. In those in whom both aspiration and cutting needles were employed, a higher percentage of specific diagnoses was achieved by cutting-needle biopsy than by aspiration biopsy: 72% vs 64% in nonlymphoproliferative malignancies, 62% vs 12% in the lymphoproliferative group, and 55% vs 22% in benign disorders. Complications were encountered in 20% of all patients studied. This study shows that, for selected chest lesions, CT-guided cutting-needle biopsies can be performed safely and are useful, especially in the diagnosis of lymphoproliferative or benign disease.