'Wax bloom' on beeswax cultural heritage objects: Exploring the causes of the phenomenon.

The term 'wax bloom' is used to describe a thin whitish crystalline layer that develops on the surface of beeswax objects under specific conditions. This phenomenon is undesirable, especially in the cases of objects with aesthetic or informational value, such as wax sculptures or historical seals. A combination of solid-state NMR and FTIR measurements allowed to obtain fairly detailed insight into the problem and to suggest a probable mechanism of its development. Secondary crystallization of unsaturated hydrocarbons from beeswax was determined as a primary cause. After the macroscopic solidification of beeswax from the melt, these molecules remain for months in a highly mobile, liquid-like state. This facilitates their diffusion to the surface, where they eventually crystallize, forming the 'wax bloom' effect. Although these results are of particular interest with respect to the conservation of beeswax artifacts, they are relevant to this material in general and help with understanding its unique properties.

Storage of RBCs results in an increased susceptibility for complement-mediated degradation.

OBJECTIVE: The objective of this study was to elucidate whether complement activation occurs during the storage of RBCs in newly formulated PAGGS-M storage medium. BACKGROUND: The reason for red blood cell (RBC) storage lesions is not yet fully understood. The contribution of complement to RBC storage lesion has not been extensively characterised. STUDY DESIGN AND METHODS: We investigated the surface expression of CD35, CD55, CD59 and CD47, as well as deposition of C3d, using flow cytometry over a storage period of up to 42 days on a weekly basis. C3d and the immunoglobulins IgG, IgM and IgA were additionally investigated via the direct antiglobulin test (DAT). The effect of contact with homologous serum for 30 min at 37 °C was also performed for C3d and CD35 and is subsequently termed as a 'transfusion simulation (TS)'. RESULTS: A weak but significant increase of C3d was observed prior to TS (anova P = 0.0103), whereas a stronger increase from 74.0 ± 12.4 to 101.2 ± 9.7 was observed post-TS (anova; P < 0.0001). These findings were confirmed by the DAT. CD35, CD55 and CD47 demonstrated a decrease in their expression over storage time (anova; P < 0.0001 each). The majority of changes occurred following 14 days. There was neither a decrease of CD59 observed nor an increase of IgG, IgM and IgA. CONCLUSION: RBCs are becoming increasingly susceptible to spontaneous complement deposition following TS, which might be associated with the decrease of C35 and CD55 by proteolytic cleavage and vesiculation during storage. As the impact of storage lesions is rather controversial, institutions involved in blood collection and administration of blood products should focus on carrying out research on the prevention of storage lesions.

Photodynamic therapy in selected cases at the ENT Clinic, Innsbruck: case reports.

Although photodynamic therapy (PDT) for the treatment of head and neck cancer has proved useful in other departments (J. Feyh, A. Goetz and W. Muller, Photodynamic therapy in head and neck surgery, J. Photochem. Photobiol. B: Biol., 7 (1990) 353-358; V.G. Schweitzer, Photodynamic therapy for treatment of head and neck cancer, Arch. Otolaryngol. Head Neck Surg., 102 (1990) 225-232; B.L. Wenig, D.M. Kurtzmann and L.I. Grossweiner, Photodynamic therapy in the treatment of squamous cell carcinomas of the head and neck, Arch. Otolaryngol. Head Neck Surg., 116 (1990) 1267-1270), it is not a standard therapy at the ENT Department of the University Clinic Innsbruck. PDT has only been applied in a few selected cases. Photosan 3 (dihaematoporphyrin either, DHE) was used as photosensitizer at a dose of 2.5 mg (kg body weight)-1 administered intravenously 24-48 h prior to photoirradiation. In one case, Photosan 3 was applied topically in a solution with 40% dimethylsulphoxide (DMSO). The light source was an argon dye laser with a wavelength of 630 nm and a power of 100 mW cm-2, coupled with a cylindrical or spherical applicator and a lens fibre tip. Patients suffering from cancer of the palatine arch, tonsil, nasal septum and glottis are reported. These selected cases had previous treatment (e.g. chemotherapy, percutaneous irradiation and surgery), and PDT was either performed as a palliative treatment for recurrence or in elderly patients to avoid inappropriate extensive and mutilating surgery.