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Changes in ventilatory capacity during the work shift were studied in workers exposed to tea dust in tea-packing plants, wood dust in two furniture factories, and virtually no dust in an inoperational power station. The FEV1 and FVC in workers exposed to dust were found to decline during the work shift by a small but significant volume. The MMFR, Vmax 50% and Vmax 75% were to variable to display any trend. No dose-response relationship could be discerned between the fall in workers' ventilatory capacity and the concentrations of airborne dust or microbes to which they were exposed. Bronchodilators could reverse the fall in FEV1.

Bone marrow myeloblasts in 15 patients with myelodysplastic syndromes were quantitated with monoclonal antibodies using the immunoalkaline phosphatase technique. Positive blasts were identified in 7 of the 15 cases with at least one of three antibodies reactive with acute myelomonocytic leukaemic cells (PMN-6, PMN-29, AML 2-23) which were non-reactive with normal myeloblasts. In 5 of these cases increased PM-81 positivity was associated with expression of at least one of the other antigens (PM-81 antibody reacts with all types of acute myeloid leukaemic cells and a certain percentage of normal myeloblasts). The data suggest an aberration of myeloid differentiation in myelodysplastic syndromes which is reflected in altered surface marker features.