Topical antimicrobicides hold great promise in reducing human immunodeficiency virus (HIV) transmission. Amphibian skin provides a rich source of broad-spectrum antimicrobial peptides including some that have antiviral activity. We tested 14 peptides derived from diverse amphibian species for the capacity to inhibit HIV infection. Three peptides (caerin 1.1, caerin 1.9, and maculatin 1.1) completely inhibited HIV infection of T cells within minutes of exposure to virus at concentrations that were not toxic to target cells. These peptides also suppressed infection by murine leukemia virus but not by reovirus, a structurally unrelated nonenveloped virus. Preincubation with peptides prevented viral fusion to target cells and disrupted the HIV envelope. Remarkably, these amphibian peptides also were highly effective in inhibiting the transfer of HIV by dendritic cells (DCs) to T cells, even when DCs were transiently exposed to peptides 8 h after virus capture. These data suggest that amphibian-derived peptides can access DC-sequestered HIV and destroy the virus before it can be transferred to T cells. Thus, amphibian-derived antimicrobial peptides show promise as topical inhibitors of mucosal HIV transmission and provide novel tools to understand the complex biology of HIV capture by DCs.

Roosting requirements and movements between foraging areas and roost sites were studied in four species of bats found in Tasmania, Eptesicus regulus, E. sagittula, Chalinolobus morio and Nyctophilus geofroyi, in an area of regrowth forest surrounded by mature eucalypt forest. Movements between traps and roost sites were normally about 1 km, with the maximum distance recorded being 4.8 km for a female N. geoffroyi. Different species of eucalypts were used as roost sites in proportion to their occurrence in the forest. However, large trees over 80 cm in diameter at breast height were favoured. There was no tendency to avoid roost sites close to the ground. Spaces used as roost sites had one dimension little greater than the bat itself. Five types of roost sites were distinguished: in fissures, inside burnt out boles, in hollows, under bark, and on the ground. Individuals changed roost sites frequently but roosts used by any one individual were in the same general vicinity. The factors associated with production of roost sites in trees were: large size, overmaturity, death, rot, and fire. No bats were found to roost in regrowth forest. Patches of mature forest will need to be retained to ensure a shortage of roosts does not occur as more areas of mature forest are converted to production forest.

A search for pair-produced doubly charged Higgs bosons has been performed using data samples corresponding to an integrated luminosity of about 614 pb −1 collected with the OPAL detector at LEP at centre-of-mass energies between 189 GeV and 209 GeV. No evidence for a signal has been observed. A mass limit of 98.5 GeV/c 2 at the 95% confidence level has been set for the doubly charged Higgs particle in left-right symmetric models. This is the first search for doubly charged Higgs bosons at centre-of-mass energies larger than 91 GeV.To be submitted to Phys. Lett. B

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