Different requirements of ICAM-1/LFA-1 adhesion in allorecognition and self-restricted antigen recognition by class II-specific T cell clones.

We have analyzed the influence of non-antigen-specific interactions between ICAM-1 and LFA-1 in target recognition by allospecific and antigen-specific T cells at the clonal level, using human and mouse fibroblasts transfected with HLA-DR1 or DR2 with or without co-expression of ICAM-1, as antigen-presenting cells. The results show a great heterogeneity in the requirements for ICAM-1/LFA-1 interactions for antigen-specific and alloreactive T cell responses and this requirement may depend on the avidity of any particular interaction. The data also show that for most alloreactive clones, ICAM-1/LFA-1 adhesion is not sufficient to facilitate efficient T cell recognition of its target molecule.

Toxicology of petroleum hydrocarbons.

Before discussing the toxicologic effects of petroleum hydrocarbons, the author reviews the considerable resources available today to investigators in this area. He then covers the toxicology of the major classes of petroleum hydrocarbons, including aliphatic, alicyclic and aromatic compounds.

Designs and operational characteristics of inhalation exposure equipment--a review.

The development of equipment for use in the experimental study of the effects of inhalable airborne materials has been reviewed. Reference is made to early descriptions of apparatus employed in the mid-nineteenth century up to the present conventional stainless steel and glass units. Whole body chambers, head only arrangements and face mask devices are described.