Low-density populations of gypsy moth, Lymantria dispar, were studied over a 10-yr period in Massachusetts. Increases in gypsy moth density were associated with declines in density of the white-footed mouse, Peromyscus leucopus, a principal predator. Furthermore, changes in density of P. leucopus populations were positively correlated with the density of acorn crops, a dominant winter food source for these mice. To demonstrate these effects we used a novel bootstrap regression method that adjusts for spatial and temporal autocorrelation in the time series data. The findings are compatible with a dual equilibrium model of gypsy moth population dynamics, in which low densities are regulated by mice and high densities are regulated by other factors, notably a virus disease.

Irritant contact dermatitis is the clinical result of sufficient inflammation arising from release of pro-inflammatory cytokines from skin cells (principally keratinocytes) in response to (usually) chemical stimuli. Different clinical forms may arise. The three main pathophysiological changes seen are skin barrier disruption, epidermal cellular changes and cytokine release. An important role of irritancy in allergic contact dermatitis (ACD) comes from earlier animal and human studies. Evidence is outlined which is consistent with a "danger model" of ACD rather than one based on a traditional "self-nonself" immune model. In such a model an antigenic signal will produce sensitization only in the presence of a danger signal; in the absence of a danger signal tolerance will occur. We propose that the danger signal in ACD is cytokine release from nonimmune skin cells (principally keratinocytes) and that both the antigenic and "danger" signals arises from the hapten.

This study illustrates that lanolin sensitization has remained at a relatively low and constant rate even in a high-risk population (i.e. patients with recent or active eczema).

Nasal S. aureus carriage is an important risk factor for SSI in MMS, conferring an over threefold increase in SSI risk. A pre-operative nasal swab provides a simple and effective risk stratification tool. The use of a topical decolonisation regimen reduces the infection rate in carriers to a level approaching non-carriers without exposure to systemic antibiotics.