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Biomedical subjects

R M Chase

Publications and source records attributed to R M Chase.

13 recordsLinked to original sources
PubMed1994

Toxic health effects including reversible macrothrombocytosis in workers exposed to asphalt fumes.

We investigated an outbreak of irritative and neurotoxic symptoms associated with exposure to asphalt fumes in a commercial lighting factory; 27 symptomatic female workers were clinically assessed including hematologic testing. When compared with a laboratory reference group (n = 107), the workers' mean platelet volume (MPV) was significantly higher and mean platelet count was lower (p = 0.013 and p = 0.048, respectively). Five months later, the factory's ventilation system was substantially modified. Follow-up assessments 6 months postmodification on 15 of the original workers documented a significant decline in acute symptoms and a lowering of the subjects' mean MPV towards normal (p = 0.0007 by paired t-test). The findings suggest that reversible macrothrombocytosis (enlarged platelets) can occur among symptomatic workers exposed to asphalt fumes.

Adult↗
PubMed1987

Correlation of serum HIV antigen and antibody with clinical status in HIV-infected patients.

An enzyme immunoassay (EIA) has been developed which detects antigen(s) (Ag) of the human immunodeficiency virus (HIV) in the serum of patients with the acquired immunodeficiency syndrome (AIDS), AIDS-related complex (ARC), and patients at high risk for HIV infection. The test has a sensitivity of approximately 50 pg/ml of HIV protein. The specificity of the assay was determined with various virus infected cell lines, normal human sera/plasma, and serum from patients not known to be at risk for HIV infection. No false-positive HIV-Ag results were seen. Sera from 69% of patients with AIDS were positive for HIV-Ag as were 46% of patients with ARC and 19% of asymptomatic, HIV-antibody-positive individuals. There were significant associations between the stage of HIV infection--ie, AIDS vs ARC vs asymptomatic--and the detection of HIV-Ag in serum (p less than 0.0001) and the lack of detection of antibody to HIV core Ag (p less than 0.0001). HIV-Ag was also found in the serum of two asymptomatic antibody-negative individuals who were at high risk for AIDS and who later developed HIV antibody. The presence of HIV-Ag in sera was confirmed by an inhibition procedure. Thus, HIV-Ag can be detected in the serum of infected individuals prior to antibody production and correlates with the clinical stage of HIV infection.

Acquired Immunodeficiency Syndrome↗
PubMed1965

The bacterial induction of homograft sensitivity. I. Effects of sensitization with group A streptococci.

Heat-killed Group A hemolytic streptococci can induce in guinea pigs a state of altered reactivity to skin homografts which is indistinguishable from that which results from sensitization with homologous tissues. Challenge of suitably prepared recipients with first-set skin homografts obtained from unrelated randomly selected donors elicits white graft reactions or accelerated rejection of such grafts. The gross and histologic appearance of these grafts is identical with that observed in similar reactions obtained in guinea pigs sensitized with homologous tissues. The ability of Group A hemolytic streptococci to induce homograft sensitivity in the guinea pig is a property shared by Types 4, 5, 6, 11, 12, 14, and 49 of Group A streptococci.

Animals↗
PubMed1965

The bacterial induction of homograft sensitivity. II. Effects of sensitization with staphylococci and other microoorganisms.

Heat-killed strains of Staphylococcus aureus and Staphylococcus albus can induce in guinea pigs a state of altered reactivity to skin homografts which is indistinguishable from that which results from sensitization with homologous tissues or Group A streptococci. Challenge of suitably prepared recipients with first-set skin homografts obtained from unrelated randomly selected donors elicits white graft reactions or accelerated rejection of such grafts. Other bacteria tested included Lancefield streptococcal groups B, C, D, E, G, H, L, and O, pneumococcus Types II, III, XIV and a rough strain, Corynebacterium xerosis, Bacillus subtilis, Escherichia coli, Aerobacter aerogenes, Salmonella typhimurium, Proteus vulgaris, Neisseria catarrhalis, Haemophilus influenzae, and two human virulent strains of Mycobacterium tuberculosis. None of these microorganisms was active in the induction of homograft sensitivity in the guinea pig. Pretreatment of recipients with Gram-negative bacterial suspensions was associated with a slight increase in the mean survival time of first-set skin homografts. Results of this study suggest the presence in staphylococci, as well as in Group A streptococci, of antigens related in their biologic effects to tissue transplantation antigens.

Animals↗