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The beneficial effects of ultraviolet light on cutaneous vitamin D synthesis, calcium metabolism, and bone formation are well known. Regarding the increasing fear of side effects from ultraviolet B (UV-B), lamps with less energy in the UV-B range have been developed. Two spectra with differences in the emission of UV-B have therefore been evaluated for their influence on calcium metabolism. A group of 24 healthy male volunteers was subdivided into two treatment groups. Group 1 was exposed to lamps with higher energy of total UV-B but less energy at the wavelengths below 300 nm than the lamps used in group 2. All subjects were irradiated ten times within 12 days. Exposure time was 3 min in the first session and time of exposure was increased by 10% in every following irradiation (suberythematous doses only). Before the first irradiation, 3 days after the last exposure, and after 4 more weeks, the serum parameters of bone metabolism were determined by standard laboratory methods. Significantly increased levels of 25-hydroxyvitamin D3 were found in both groups. There was only a slight increase of 1,25-dihydroxyvitamin D3. Parathyroid hormone decreased significantly in group 2 only. The data would suggest beneficial effects on bone metabolism for both regimens. The observed effects were more pronounced when shorter wavelengths (group 2) were applied, although the total energy of UV-B was lower in these lamps.

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One hundred twenty-one patients treated for nasopharyngeal carcinoma with radiation therapy were analyzed; 85 were male, 36 were female. Twenty-one percent had tumour stage T0/T1; 32.5%, T2; 27.5%, T3; and 19%, T4. In 75% of the cases, the lymph nodes were involved. Twelve patients underwent a neck dissection. Histology showed squamous cell carcinoma in 38%, lymphoepitheloid carcinoma in 41.4%, undifferentiated carcinoma in 19%, and adenocarcinoma in 2%. Beginning in 1980, a modified radiation technique with large portals and an increase of the dose from 57.1 Gy to 61.5 Gy targe volume dose was used. Five year overall survival was 32.1%, recurrence-free survival, 30.7%; and local recurrence free survival, 45.8%. Age, sex, and T stage had no significant influence on survival. Multivariate analysis (Cox model) showed that involvement of the lymph nodes, histology, and the new irradiation technique with the higher total dose significantly influenced survival.

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