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.

A three month inhalation toxicity study in the squirrel monkey (Saimiri sciureus) with terbutaline sulfate (Bricanyl).

A study of the subacute toxicity of inhaled terbutaline sulfate was performed in the Squirrel monkey (Saimiri sciureus). 3 groups of monkeys were exposed 1 h daily 7 days/week for 3 months to terbutaline sulfate aerosols at concentrations of 0.039, 0.

Inhalation toxicology.

Two kinds of problems associated with developing standardized procedures for the safety evaluation of new compounds are identified. The first of these is the question of the desirability of using such standard methods. It is concluded that a basic set of procedures is to be recommended, but this should be supplemented with special tests as may be indicated.

Inhalation studies of nickel sulfide in pulmonary carcinogenesis of rats.

Two hundred twenty-six specific pathogenfree male and female F344 rats were exposed to nickel sulfide inhalations for 78 weeks (5 days/wk, 6 hr/day) and observed for an adiditional 30-week period. For the same amount of time, 214 rats were exposed to filtered room air and served as controls. Rats exposed to nickel sulfide showed a significantly higher incidence of pulmonary hyperplastic and neoplastic lesions originating from the bronchial and bronchiloo-alveloar segments.

Blood fluorocarbon levels following exposure to household aerosols.

Measurement of blood fluorocarbon levels was carried out in subjects exposed to a number of household aerosol products containing fluorocarbon gases as propellants. All aerosols were used according to manufacturers' recommendations. The general purpose of the study was to determine whether with normal routine exposure to a wide variety of household aerosol products fluorocarbon could be found in the blood and if so, to check the potential toxicity of the levels reached.