Examining play sand products for asbestos contamination.
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Asbestos↗
Biomedical subjects
J S Webber
Publications and source records attributed to J S Webber.
Diagnostic utility of a mouse monoclonal antibody (5-21-3) employed as a competitive probe in an immunoassay to detect antibody to HIV-1 gp41.
A mouse monoclonal antibody, designated 5-21-3, was raised against HIV-1 gp41 using detergent-disrupted virus as the immunogen. Antibody 5-21-3 was conjugated to horseradish peroxidase (HRP) and employed as a competitive probe against normal and HIV-1 antibody-positive sera in an immunoassay to detect the presence of antibody to HIV-1 gp41. The diagnostic utility of the competitive monoclonal immunoassay was assessed by correlation to a similar assay which employed HRP-labeled polyclonal IgG from a gp41-seropositive donor as the competitive probe. The monoclonal immunoassay was greater than 98% as sensitive and 99% as specific as the polyclonal immunoassay, regardless of the geographic source or disease state of the donor. The monoclonal immunoassay also was nearly as effective as the polyclonal immunoassay in detecting points of seroconversion in individuals enrolled in longitudinal studies. Of particular interest was the finding that the epitope recognized by monoclonal antibody 5-21-3 did not map to the well-characterized gp41 immunodominant region.
Animals↗
Asbestos-contaminated drinking water: its impact on household air.
Asbestos contamination in excess of 10 billion fibers per liter was detected in a community's drinking water. To assess the possibility of waterborne asbestos becoming airborne, air samples were collected from impacted houses receiving contaminated water from three control houses. Collected within each house were three samples on 0.6-micrometer-pore Nuclepore filters and three samples on 0.8-micrometer-pore Millipore filters. In addition, bulk samples of suspect material and water samples were collected. Mean waterborne asbestos concentrations were 24 million fibers per liter (MFL) in the impacted houses versus only 1.1 MFL in the control houses. Transmission electron microscopy revealed that airborne asbestos concentrations were highest in impacted houses, with airborne asbestos concentrations positively correlated with waterborne concentrations. For fiber and mass measurements on both filter types, airborne asbestos concentrations were significantly higher in the impacted houses: mean concentrations in impacted houses were 0.12 fibers/cm3 and 1.7 ng/m3 on Nuclepore filters and 0.053 fibers/cm3 and 2.3 ng/m3 on Millipore filters versus only 0.037 fibers/cm3 and 0.31 ng/m3 on Nuclepore filters and 0.0077 fibers/cm3 and 0.14 ng/m3 on Millipore filters from control houses. Also detected in the air samples from impacted houses were clusters of chrysotile, often with several hundreds of fibers. When estimates of these individual fibers were added to the total fiber count, the difference between the impacted and control houses became even greater. The increased concentrations in impacted houses were due primarily to short (less than 1 micrometer) fibers. Bulk samples did not reveal likely materials within the impacted houses to account for these differences. Thus high levels of waterborne asbestos were apparently the source of increased concentrations of airborne asbestos within these houses.
Air Pollutants↗
Reliable detection of individuals seropositive for the human immunodeficiency virus (HIV) by competitive immunoassays using Escherichia coli-expressed HIV structural proteins.
We molecularly cloned the gag and env genes of the human immunodeficiency virus (HIV) and expressed fragments of these genes in Escherichia coli. Using the recombinant core and envelope proteins, we developed two competitive immunoassays (CIAs). Samples that recognized either the envelope or core proteins were considered positive for antibodies to HIV. This test system was comparable with western blot in detecting antibodies in patients with AIDS or AIDS-related complex that were repeatably reactive in the HIV screening test. All 360 individuals who were positive by western blot were positive by the CIA. A total of 844 samples repeatably reactive by an ELISA screening test were negative both by western blot and by the CIA; 48 samples positive by ELISA, but negative or indeterminate by western blot, were positive by the CIA. Alternate research procedures verified the positivity of these individuals. These data indicate that the CIA described here may be useful as an adjunct or alternative to the western blot.
AIDS-Related Complex↗
A microcomputer program for the generation of random grid squares in quantitative analysis.
Subjectivity in selecting random grid squares for routine quantitative analysis can be circumvented through a combination of finder grids and a computer program. The simple BASIC program described in this paper generates a list of random grid-square numbers, which are sequentially analyzed. The concept was applied in the quantitation of asbestos and other microparticles in environmental samples. The use of finder grids and this program can also be useful in quality-control programs and in cross-referencing analyses, as well as in the study of biological specimens.
Asbestos↗
Performance evaluation of the Abbott HTLV III EIA, a test for antibody to HTLV III in donor blood.
An enzyme immunoassay (EIA), designed to detect antibodies to human T-cell lymphotropic virus type III (HTLV III), was evaluated. The antibody test was found to be highly sensitive; serum from 221 of 223 (99.1%) patients with acquired immune deficiency syndrome (AIDS) was positive for antibodies to HTLV III. In addition, the antibody test was found to be highly specific; approximately 99.75% of 20,720 serum or plasma samples from blood donors were negative for antibody to HTLV III. In most cases, the Western Blot analysis agreed well with the EIA. Eighty-one of 82 (98.8%) EIA-positive samples from patients with AIDS were Western Blot positive. Of the EIA-positive blood donors, 21 of 36 (58%) were detected and confirmed by Western Blot analysis. A solid-phase competitive EIA also was evaluated as an alternate procedure. The preliminary results indicate that this immunoassay has a high degree of sensitivity and specificity and could serve as an alternate procedure to detect antibody to HTLV III.
Acquired Immunodeficiency Syndrome↗