Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “RADIODERMATITIS”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 739 records · Page 41Linked to original sources
PubMed1998

The inhibitory effect of glabridin from licorice extracts on melanogenesis and inflammation.

Glabridin is the main ingredient in hydrophobic fraction of licorice extract affecting on skins. In this study, we investigated inhibitory effects of glabridin on melanogenesis and inflammation using cultured B16 murine melanoma cells and guinea pig skins. The results indicated that glabridin inhibits tyrosinase activity of these cells at concentrations of 0.1 to 1.0 microg/ml and had no detectable effect on their DNA synthesis. Combined analysis of SDS-polyacrylamide gel electrophoresis and DOPA staining on the large granule fraction of these cells disclosed that glabridin decreased specifically the activities of T1 and T3 tyrosinase isozymes. It was also shown that UVB-induced pigmentation and erythema in the skins of guinea pigs were inhibited by topical applications of 0.5% glabridin. Anti-inflammatory effects of glabridin in vitro were also shown by its inhibition of superoxide anion productions and cyclooxygenase activities. These data indicated that glabridin is a unique compound possessing more than one function; not only the inhibition of melanogenesis but also the inhibition of inflammation in the skins. By replacing each of hydroxyl groups of glabridin with others, it was revealed that the inhibitory effect of 2'-O-ethyl glabridin was significantly stronger than that of 4'-O-ethyl-glabridin on melanin synthesis in cultured B16 cells at the concentration of 1.0 mg/ml. With replacement of both of two hydroxyl groups, the inhibitory effect was totally lost. Based on these data, we concluded that two hydroxyl groups of glabridin are important for the inhibition of melanin synthesis and that the hydroxyl group at the 4' position of this compound is more closely related to melanin synthesis.

Administration, Topical↗
PubMed2004

Objective measurements of radiotherapy-induced erythema.

BACKGROUND/AIMS: The development of acute radiation erythema is a common phenomenon among patients under-going radiotherapy treatment. Because of the absence of reliable objective classification methods, the degree of skin reaction can at present mainly be judged subjectively in the clinic. This has motivated the present preliminary study,concerning the first steps in the development of an objective method for skin reaction classification. METHODS: Three non-invasive techniques were used:near-infrared (NIR) spectroscopy, laser Doppler perfusion imaging and digital photography. The NIR spectra were analysed with principal component analysis (PCA), and the results from the other two with traditional univariate methods. Measurements were made on breast cancer patients who had been exposed to different irradiation doses. A total of 28 breast cancer patients participated one to three times each; 12 were treated with photons at 4 or 6MeV and 16 were treated with high-energy electrons between 10 and 20 MeV to a maximum dose of 50 Gy. RESULTS: PCA of NIR spectra shows that information on radiation dose lies mainly in the first principal component. It is observed that the higher the dose the higher the score value. The results from the laser Doppler measurements show that in 79% of the cases the perfusion increases significantly with radiation dose. Analysis of the digital photography shows that a proposed skin redness index(SRI), increases with a higher radiation dose. However,the increase in most cases is not significant. By combining all data, correlation to radiation doses was seen for 74% of the patients who participated more than once. CONCLUSION: All three non-invasive methods correlate with the radiation dose but to various degrees. NIR spectroscopy, laser Doppler and a combination of the three techniques are the most promising methods for characterising erythema.

Breast Neoplasms↗
PubMed2006

[Radiotherapy of basal cell carcinoma of the face and head: Importance of low dose per fraction on long-term outcome].

BACKGROUND: Radiotherapy plays an important role in the treatment of basal cell carcinoma of the face and head and achieves cure rates of 92-96 %. Different fractionation concepts of radiotherapy have been described. This study investigates the efficacy, as well as acute and chronic toxicity, of a slightly hypo-fractionated radiotherapy schedule. PATIENTS AND METHODS: 85 patients with 104 tumors underwent radiotherapy for basal cell carcinoma of the face and head. The radiotherapy schedule was 5 x 3 Gray/week up to a total dose of 57 Gray in 95 % of patients. Acute and late radiotherapy toxicity and cosmetic outcome were evaluated in long-term follow-up. RESULTS: No recurrence was observed. In 87 % of tumors, only low acute toxicity occurred at the end of radiotherapy. Late toxicity, if observed, was low in most patients. "Excellent" or "good" cosmesis was achieved in 94 % of tumors at last follow-up. CONCLUSIONS: Our radiotherapy schedule achieves a very high local control rate and very good cosmetic and functional results. This fractionation can be recommended as a standardized radiotherapy treatment for basal cell carcinoma of the face and head.

Aged↗
PubMedDate not supplied

Enhancement of hidden structures of early skin fibrosis using polarization degree patterns and Pearson correlation analysis.

The skin of athymic nude mice is irradiated with a single dose of x-ray irradiation that initiated fibrosis. Digital photographs of the irradiated mice are taken by illuminating the mouse skin with linearly polarized probe light of 650 nm. The specific pattern of the surface distribution of the degree of polarization enables the detection of initial skin fibrosis structures that were not visually apparent. Data processing of the raw spatial distributions of the degree of polarization based on Fourier filtering of the high-frequency noise improves subjective perception of the revealed structure in the images. In addition, Pearson correlation analysis provides information about skin structural size and directionality.

Algorithms↗
PubMed2004

Comparative skin dose measurement in the treatment of anal canal cancer: conventional versus conformal therapy.

The subject of this work was to compare the effect of Conventional and Conformal techniques, used for anal canal cancer treatments, on the skin dose deposition. Skin dose was measured on a Rando phantom using XR-T GAFCHROMIC film. A skin surface dose histogram was constructed and a skin dose profile in the sagittal direction of the perineal region was measured, for both techniques. The measured skin dose in the anterior and posterior region of the skin exposed to radiation is from two to ten times higher when using a conventional technique. In the perineal region, an 85% of the prescription isodose line spreads over 25% of the perineum for conformal technique as compared to 65% with conventional techniques. In addition, conformal technique dose profiles confine better the anatomical position of the anal verge than conventional techniques. Results presented in this work confirm clinically observed improvement in the radiation-induced dermatitis when using the conformal technique.

Anus Neoplasms↗
PubMedDate not supplied

"Battered data"--some clinical effects of the abuse of multiple regression methods: the NSD.

The NSD equation, D = 1850 x T0.11 x N0.24, is a celebrated transmogrification of Cohen's two well-known collations of data on response to clinical irradiations (3 degrees erythema and 0.90 ablation of skin cancer) in which the relation of D and T is fixed by the data selected by Cohen and the additional constraint that N correspond to a schedule of five treatments per week is imposed subsequently by Ellis. The present paper shows that the equation, if correct, would have little clinical significance because the proportion, P, in which the dose, D, elicits the 3 degree erythema is unspecified: D = D(P) = D(?). Since the two Cohen collations each summarize the measurements on a different set of observational units, it is questionable whether the equation can be correct. This paper further shows that the appropriate (Least Squares) estimates of the three-parameter equation derived for the Cohen data under the Ellis constraint (five treatments per week) is in fact: D(1.0) = 1710 x T0.54 x N-0.26. The paper shows that the NSD equation is also incorrect because the ad hoc method by which Ellis estimates the exponents is inconsistent with the constraints imposed by Cohen and Ellis upon the parameters of the multivariate frequency distribution of the data set. The paper shows that the method by which the correct LS estimates of the exponents were obtained from the Cohen-Ellis data is consistent with these constraints and, therefore, this equation is a correct graduation of any other set of treatment regimens which is also consistent with the Cohen and Ellis constraints. The paper further shows that for such data sets there are, in fact, only two independent continuous variables, either D and T or D and N, since the Ellis constraint requires that N and T be collinear. Thus, the best linear graduation has the typical form: D congruent to 1900T0.32. This is "best" in the usual sense: both prediction and confidence intervals are provided for the estimates of the conditional "tolerance dose" D; these are not inflated by the presence of a collinear variable. This equation is biased, however, by the absence of the collinear variable. The TDF and the CRE concepts are derived from the NSD and, therefore, the deficiencies of the latter concept which we discuss may be expected to encumber these progeny as well. The two characteristic features of the Cohen (Ellis)-type data which impede the construction of useful estimates of the putative separate effects of N and T upon the response of tissues to irradiation are that (1) these data do not include specifications of either a tissue defect or its incidence, and (2) the variables N and T are collinear. Appendices I and II describe methods by which the effects of these features may be eliminated (I) or reduced (II).

Carcinoma, Squamous Cell↗
PubMed1994

Death of a classified worker probably caused by overexposure to gamma radiation.

This paper describes the case of an industrial radiographer who was seriously overexposed to gamma radiation. The exact circumstances of this exposure were not established but it was concluded that he was repeatedly irradiated probably to a total average whole body dose of at least 10 Gy over several years. Also, a much larger dose to a hand required its partial amputation. He developed myelodysplasia, which progressed to acute myeloid leukaemia from which he died. Karyotypic examination of the leukaemic blasts showed changes very similar to those associated with secondary leukaemia that may develop after radio or chemotherapy. The paper describes his medical case history, the investigation of his workplace, and the attempts to estimate his radiation dose by chromosomal analysis of blood lymphocytes and electron spin resonance of dental enamel and bone.

Acute Disease↗