Raoultella ornithinolytica bacteremia in an infant with visceral heterotaxy.

A case of Raoultella ornithinolytica bacteremia in an infant with visceral heterotaxy is reported. Physical examination was remarkable for markedly red skin flushing, not unlike that seen during histamine fish poisoning. R. ornithinolytica is a histamine-producing bacterium recently elucidated as a major cause of histamine fish poisoning. Only 2 other cases of human infection by R. ornithinolytica have been reported.

Hidradenitis suppurativa managed with adalimumab.

Hidradenitis suppurativa (HS), a chronic, inflammatory, relapsing disease of the apocrine glands in the skin, commonly occurs in women aged 20 to 40 years. Patients typically present with discomfort and/or itching associated with papules or nodules that may recur and lead to abscess formation and sinus tracts. Recent reports have demonstrated that adalimumab, a tumor necrosis factor (TNF) antagonist, may be effective in the treatment of patients with HS who have failed conventional therapy. The authors describe 3 patients who experienced the resolution of skin lesions associated with HS after treatment with adalimumab. The patients found this treatment to be convenient, as they could administer the therapy at home, and 1 patient was able to avoid surgical intervention through use of TNF-antagonist therapy. Adalimumab may resolve symptoms of HS when conventional therapy fails. More studies are necessary to investigate the efficacy and safety of adalimumab for the treatment of HS.

Interactions of the human calcitonin fragment 9-32 with phospholipids: a monolayer study.

Human calcitonin and its C-terminal fragment 9-32 (hCT(9-32)) administered in a spray translocate into respiratory nasal epithelium with an effect similar to intravenous injection. hCT(9-32) is an efficient carrier to transfer the green fluorescent protein into excised bovine nasal mucosa. To understand the translocation of hCT(9-32) across plasma membranes, we investigated its interactions with phospholipids and its interfacial structure using model lipid monolayers. A combination of physicochemical methods was applied including surface tension measurements on adsorbed and spread monolayers at the air-water interface, Fourier transform infrared, circular dichroism, and atomic force microscopy on Langmuir-Blodgett monolayers. The results disclose that hCT(9-32) preferentially interacts with negatively charged phospholipids and does not insert spontaneously into lipid monolayers. This supports a nonreceptor-mediated endocytic internalization pathway as previously suggested. Structural studies revealed a random coil conformation of hCT(9-32) in solution, transforming to alpha-helices when the peptide is localized at lipid-free or lipid-containing air-water interfaces. Atomic force microscopy studies of monolayers of the peptide alone or mixed with dioleoylphosphatidylcholine revealed that hCT(9-32) forms filaments rolled into spirals. In contrast, when interacting with dioleoylphosphatidylglycerol, hCT(9-32) does not adopt filamentous structures. A molecular model and packing is proposed for the spiral-forming hCT(9-32).

Protein structural changes induced by their uptake at interfaces.

For insertion into lipidic media, most hydrosoluble proteins must cross the lipid-water interface and thus undergo conformational transitions. According to their chemical sequences these transitions may be restricted to changes involving only the tertiary structure, while for other proteins this environment modification will induce drastic changes such as the unfolding of large domains. The structural transitions are mainly governed by the presence of hydrophobic domains and/or by the existence of induced amphipathic properties.