Asbestos exposure among finnish lung cancer patients: Occupational history and fiber concentration in lung tissue

In a series of 65 surgically treated lung cancer patients, past exposure to asbestos was evaluated by personal interviews, and by scanning electron microscopy analyses of the mineral fibers in lung tissue. Lung tissue samples of 17 autopsied male office workers were analyzed as referents. According to occupational history, 37% of the lung cancer patients had definite or probable, 31% possible, and 32% unlikely exposure to asbestos. The fiber concentration in the lung tissue ranged from <0.1 to 65 million fibers per gram dry tissue in the lung cancer group, and from <0.1 to 0.8 million fibers per gram dry tissue in the reference group. In 26% of the lung cancer patients, but in none of the referents, the fiber concentration exceeded 1 million fibers per gram dry tissue. Most of the exposed patients had been employed in various construction jobs, and valuable information about the exposure levels could be obtained by the mineral fiber analyses. In general, there was a good accord between the exposure categorization and the fiber burden measured in the lung. © 1993 Wiley-Liss, Inc.     

Spurious E rosette formation in B cell chronic lymphocytic leukemia due to monoclonal anti-sheep RBC antibody

The apparent simultaneous presence of surface markers characteristic of both B and T cells is a phenomenon being described with increasing frequency in patients with chronic lymphocytic leukemia (CLL). We describe a patient with CLL whose B lymphocytes possessed surface immunoglobulin reactive with neuraminidase-treated sheep erythrocytes (SRBCs) and produced E rosette formation. Cytofluorography using monoclonal antibodies demonstrated the B cell nature of these cells and the absence of the SRBC receptor. Further documentation that the binding of SRBCs was mediated through immunologic reaction included E rosette formation inhibition by monospecific antisera and hemagglutination of SRBCs by a paraprotein isolated from the patient's serum. Fusion of the CLL cells with a human hypoxanthine-aminopterin- thymidine-sensitive plasma cell line resulted in the production of human hybridomas that secreted the SRBC-reactive IgM antibody. An analysis of clinical histories of CLL patients whose cells exhibited this phenomenon from both immunologic and clinical perspectives is presented.     

MR angiography with two-dimensional acquisition and three-dimensional display. Work in progress

Magnetic resonance arteriograms of healthy volunteers and selected patients were produced with a new spoiled gradient-echo pulse sequence based on time-of-flight phenomena. The procedure involves sequential acquisition of many contiguous, thin (1.5-mm) axial two-dimensional sections. These volume data are then submitted to a raytracing projection program, which retrospectively yields multiple arbitrary projection angles rotating through any plane. Venous structures are suppressed with a presaturation slab superior to the current section. The slab location is advanced in concert with advancement of each new section location. The acquisition time varies from 6 to 13 minutes, depending on the number of sections acquired for three-dimensional display. This method obviates the subtraction of image data sets to suppress signals from stationary spins, is more sensitive to slow blood flow than three-dimensional methods of acquisition, and shows special promise for the study of extracranial vascular disease.     

A ricin A chain-containing immunotoxin that kills human T lymphocytes in vitro

An immunotoxin specific for human T lymphocytes was prepared by coupling an IgG2a anti-CD3 murine monoclonal antibody (64.1) to purified ricin A chain (64.1-A). Treatment of blood mononuclear cells with this immunotoxin at a concentration of 1.7 X 10(-9) mol/L for two hours at 37 degrees C in the presence of 20 mmol/L NH4Cl decreased phytohemagglutinin-stimulated protein synthesis by 95%. In addition, a sensitive culture assay showed that fewer than 0.03% T cells remained after treatment of human bone marrow mononuclear cells with 64.1-A at a concentration of 1.7 X 10(-9) mol/L. The inhibition of protein synthesis could be prevented by preincubating cells with unconjugated 64.1 antibody but not by preincubating cells with a control IgG2a antibody that binds to a different T cell antigen (CD5). At concentrations up to 1 X 10(-8) mol/L, 64.1-A had little effect on blood mononuclear cells from baboons or human myeloid precursors (CFU- GM), which do not express the CD3 antigen recognized by 64.1. Taken together, these results indicate that the toxicity of 64.1-A was specific and that 64.1-A may be a useful reagent for depleting T cells from donor marrow as a means of preventing acute graft-v-host disease after allogeneic bone marrow transplantation.     

Bronchogenic cyst presenting in the neonatal period

A term infant presented at birth with worsening respiratory distress which resulted in him requiring mechanical ventilation. A CT scan of the chest revealed a bronchogenic cyst, removal of which resulted in full recovery and, to date, no respiratory sequelae.