Formation of photoproducts and cytotoxicity of bilirubin irradiated with turquoise and blue phototherapy light.

Aim: To compare a new turquoise ("green") fluorescent phototherapy lamp (490 nm) with a conventional blue phototherapy lamp (450 nm) with respect to cytotoxicity and photochemical effects of bilirubin.

Methods: Mouse lymphoma cells (L5178Y-R) in the presence of bilirubin solutions were exposed to phototherapy light. Occurrence of necrosis and apoptosis, reduction of mitotic index and inhibited cell growth was assayed by appropriate methods.

Effects of bilirubin and phototherapy on osmotic fragility and haematoporphyrin-induced photohaemolysis of normal erythrocytes and spherocytes.

Aim: To study the effects of phototherapy on erythrocyte haemolysis in vitro and to determine possible differences in sensitivity to phototherapy between normal erythrocytes and spherocytes.

Methods: Erythrocytes from four normal healthy donors and two donors with hereditary spherocytosis were treated with bilirubin (160 microM) in the presence of human serum albumin in the molecular ratio bilirubin/albumin 0.8.

Bilirubin-induced cell death during continuous and intermittent phototherapy and in the dark.

Aim: To compare continuous and intermittent light exposure in the presence of bilirubin with respect to cellular damage. Furthermore, it was of interest to characterize the nature of cellular toxicity of bilirubin in the dark.

Method: A murine lymphoma cell line, L5178Y-R (LY-R), was exposed to solutions of bilirubin (160 microM) supplemented with human serum albumin (200 microM) and irradiated with phototherapy light (Philips 20W/52) at a constant total dose of approximately 500 kJ/m2.

In vitro cell death induced by irradiation and chemicals relevant for dental applications; dose-response and potentiation effects.

Resin-based dental materials polymerized using blue light are frequently used in dental practice and may come in contact with the oral mucosa. Remnants from oral hygiene product ingredients, such as sodium lauryl sulfate (SLS), add to the chemical exposure of the mucosa. The aim of the present in vitro study was to elucidate the cytotoxic effects in terms of apoptosis and necrosis after exposures to combinations of an adhesive (0.

Health hazards associated with curing light in the dental clinic.

The assessment of side effects of substances encountered in odontology by patients and the dental team must include the direct and indirect effects of irradiation emitted from polymerisation devices. The eyes of the lamp operators are at risk from acute and cumulative effects, mainly due to back-reflection of the blue light. Furthermore, phototoxic and photoallergic reactions originating from absorbed radiation in endogenous or exogenous substances accumulated in the operators' eyes and skin (hands) as well as the patients' oral mucosa must also be taken into consideration.