Since the late 1990s, a respiratory syndrome has been repetitively observed in humans concomitant with Ostreopsis spp. blooms (mainly O. cf. ovata) in the Mediterranean area. Previous studies have demonstrated that O. cf. ovata produces analogues of palytoxin (ovatoxins and a putative palytoxin), one of the most potent marine toxins. On the basis of the observed association between O. cf. ovata blooms, respiratory illness in people, and detection of palytoxin complex in algal samples, toxic aerosols, containing Ostreopsis cells and/or the toxins they produce, were postulated to be the cause of human illness. A small scale monitoring study of marine aerosol carried out along the Tuscan coasts (Italy) in 2009 and 2010 is reported. Aerosols were collected concomitantly with O. cf. ovata blooms, and they were analyzed by both PCR assays and LC-HRMS. The results, besides confirming the presence of O. cf. ovata cells, demonstrated for the first time the occurrence of ovatoxins in the aerosol at levels of 2.4 pg of ovatoxins per liter of air. Given the lack of toxicological data on palytoxins by inhalation exposure, our results are only a first step toward a more comprehensive understanding of the Ostreopsis-related respiratory syndrome.

Type 1 diabetes mellitus is thought to derive from organ-specific autoimmune reactions, probably triggered by environmental factors. In view of the possible involvement of mumps virus and reoviruses in the pathogenesis of autoimmune endocrine disease, serum antibody levels to these viruses were measured in newly-diagnosed diabetic patients aged 5 to 25 years and in matched control subjects. Diabetic patients showed a significantly lower prevalence and reduced titers of antibodies to mumps and reoviruses. By contrast, the antibody response to measles virus (a non-diabetogenic agent) was remarkably similar in the two groups. It is suggested that individuals with an impaired humoral response to some viral agents are at increased risk of developing diabetes when exposed to pancreotropic viruses.

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Killed Staphylococcus aureus strain Cowan I cells inhibit contact sensitivity to oxazolone in mice, when given intravenously 24–72 h before sensitization. With transfer experiments it was found that the cells responsible for the suppression are antigen-specific, nylon-adherent, resistant to antitheta serum + C, and sensitive to anti-mouse Ig serum + C. These suppressor B cells bear anti-oxazolone immunoglobulins and appear to exert their suppressive activity by preventing the contact sensitizer from reaching the specific reactive T cells.

The peripheral blood lymphocyte response of patients with ankylosing spondylitis (AS) to several polyclonal B cell activators was investigated. No differences were found in the reactivity to pokeweed mitogen and protein A between patients and controls; in contrast, the peripheral blood lymphocyte response to Staphylococcus aureus strain Cowan I (SAC) was significantly higher in patients with AS than in controls. This responsiveness was not influenced either by the presence of the HLA-B27 antigen or by environmental factors or associated diseases, and it was higher in patients with active AS than in those with inactive disease. The percentage of circulating B celis was normal. The responses to T celi mitogens and the percentages of T celi subpopulations were similar in patients and in controls. The peripheral blood lymphocyte hyperactivity of patients with AS to SAC was associated with an increased in vitro production of immunoglobulins.