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Field-grown bean plants (Phaseolus vulgaris L. cv. Taylor's Horticultural) were exposed to ambient air pollution in open-top chambers (OTCs) at two sites (urban and rural) in Northern Italy. At each site three OTCs received charcoal/Purafil filtered air (F) and three ambient non-filtered air (NF). Net photosynthesis, stomatal conductance and transpiration of selected leaves were measured from July to September 1989. The results showed that net photosynthesis of NF plants decreased progressively during the season in comparison with the F ones. The difference was greatest at September (-40%, at urban site and 23% at rural site). The maximum impairment of photosynthesis occurred during the ripening of the pods. For about 2 wk in August stomatal conductance of NF plants was greater than that of F plants at both sites. Later in August and in September the situation was reversed and stomatal conductance of NF plants was significantly lower than that of F ones. By this time a significant negative correlation between net photosynthesis and sub-stomatal carbon dioxide concentration was found in NF plants at both sites, indicating an increased importance of non-stomatal limitation of photosynthesis. The measured leaves did not show any visible symptom of damage at the time of the physiological measurements; however brown spots on the upper surface became evident later on 20% of total leaves of NF plants. Ambient ozone is suspected to be the major air contaminant involved in causing the observed physiological effects. [ABSTRACT FROM AUTHOR]

Patients with advanced head and neck squamous cell carcinoma (HNSCC) are severely immunocompromised. In virtually all such patients who have been studied, reduced numbers of circulating CD3+ T-cell-receptor (TCR)alpha/beta+ T lymphocytes, a reduction of natural killer (NK) activity, and a poor induction of lymphokine-activated killer (LAK) cell activity (following in vitro treatment with recombinant interleukin-2 [rIL-2]) have been detected. Recently, however, it has been demonstrated that perilymphatic injections of low doses of rIL-2 may induce a local reduction of tumor masses in these patients. The present study, a cooperative pilot effort on the clinical effects of this route of administration, showed an activation of the lytic machinery in lymphocytes belonging to the T-cell lineage, as well as a potentiation of NK activity in the peripheral blood. These findings demonstrated that the severe immunodeficiency of HNSCC patients may be at least partially corrected by in vivo administration of rIL-2.