Therapeutic mammaplasty.

Therapeutic mammaplasty is a term for the oncoplastic application of breast reduction and mastopexy techniques to treat selected breast tumours by breast conserving surgery (BCS). It has the potential to increase the indications for BCS as well as achieve more acceptable aesthetic results from it in suitable women. Now an established technique in the range of oncoplastic options for women with breast cancer, it finds common application and is associated with good oncological and quality of life outcomes.

A comparative study on potential cytogenetic fingerprints for radiation LET in human lymphocytes.

PURPOSE: To carry out a comparative study on potential cytogenetic fingerprints for radiation LET in human metaphase lymphocytes. MATERIALS AND METHOD: Human lymphocytes were irradiated in vitro with 3.0 Gy 60Co gamma-rays, 0.9 Gy 3H beta-rays or 0.2 Gy 2.7 Mev neutrons. Detailed chromosome aberrations were analysed by combined FISH with pan-telomere staining and specific whole-chromosome painting (1, 2 and 4). Total chromosome translocations and insertions were also analysed by multicolour whole-chromosome painting (chromosomes 1, 2 and 4 orange, chromosomes 3, 5 and 6 green). RESULTS: Among the six proposed radiation cytogenetic fingerprints, the ratio of total simple translocations to insertions (I-ratio), showed the largest difference between low-LET 60Co gamma-ray and high-LET neutron radiation. The ratios of complete exchanges to incomplete rejoinings [S(I)-ratio] and dicentrics to interstitial deletions (H-ratio), showed a similar significant difference between low- and high-LET radiation. The ratios of centric rings to interstitial deletion (G-ratio) showed a trend of LET-related difference, but the difference was not significant in this data set. The ratios of dicentrics to centric rings (F-ratio) and apparent complete exchanges to hidden complete exchanges [S(II)-ratio], showed no difference between low- and high-LET radiation. In the 1426 radiation-induced chromosome aberrations observed after 52 h culture, evidence for sister-chromatid fusion but not telomere addition was found. CONCLUSION: Pan-telomere staining plus specific whole chromosome painting allows simultaneous and objective detection of complete or incomplete chromosome exchanges and interstitial or terminal deletions in human peripheral lymphocytes. Of the six proposed cytogenetic ratios, the I-ratio is the most effective cytogenetic fingerprint for distinguishing low-LET from high-LET radiation in human metaphase human lymphocytes.

Alpha coefficient of dose-response for chromosome translocations measured by FISH in human lymphocytes exposed to chronic 60Co gamma rays at body temperature.

PURPOSE: To measure the alpha coefficient, the initial slope of the translocation dose-response curve, for 60Co gamma-rays in human lymphocytes. MATERIALS AND METHODS: Human lymphocytes were exposed to 0, 0.32, 0.62 and 0.92 Gy of chronic 60Co gamma-rays under conditions that reduce the metabolic stress to the cells. Chromosome translocation frequencies were measured using fluorescence in situ hybridization with a whole-chromosome probe cocktail specific for chromosomes 1, 2, 4 (orange) and 3, 5, 6 (green). RESULTS: A total of 72,383 metaphases were analysed (33,429 in exposed cells) in two individuals. The shape of the dose-response curves for translocations was linear, and alpha coefficient was measured as 0.024 +/- 0.002 translocations per cell per Gy for the combined data for two 24 year old male donors. CONCLUSION: The alpha coefficients measured after chronic exposure were in good agreement with that reported in the literature for acute, low-dose exposure of human lymphocytes to 60Co gamma-rays.

Exposure temperature, but not donor age, is a confounding factor for in vitro translocation production by chronic irradiation.

PURPOSE: To assess the effects of incubation temperature during irradiation, and of donor age, on the in vitro induction of chromosomal translocations in human lymphocytes. MATERIAL AND METHODS: Lymphocytes from six human male donors were scored, using fluorescence in situ hybridization, for the presence of chromosomal translocations involving chromosomes 1 to 6 after in vitro, chronic exposure (delivered continuously over 48 h at 37 degrees C or at 20 degrees C) to tritium beta-rays or 60Co gamma-rays. RESULTS: No age-related difference in the alpha coefficients of the fitted induction curves was observed for gamma-ray-exposed lymphocytes obtained from four donors whose ages ranged from 24 to 79 years, or for tritium beta-ray-exposed lymphocytes from two donors aged 36 and 62 years. Duplicate samples from one donor, irradiated concurrently at 20 degrees C or 37 degrees C, gave significantly different alpha coefficients: 0.128+/-0.008 and 0.053+/-0.004, respectively (p<0.0001). The S-ratio (the ratio of induced complete to incomplete translocations) was found to be independent of radiation dose, donor age and exposure temperature. CONCLUSIONS: For biodosimetry in chronic irradiation situations, the use of alpha coefficients derived from the dose-response curves of cells chronically irradiated in vitro at body temperature is recommended. With respect to induction rates, donor age does not appear to be a confounding factor. The S-ratio is independent of radiation doses, exposure temperatures, or donor ages.

Biological dosimetry of beta-ray exposure from tritium using chromosome translocations in human lymphocytes analyzed by fluorescence in situ hybridization.

Radiation exposures from tritium make up a substantial fraction of the occupational and accidental radiation exposures associated with the nuclear power industry. Tritiated water, the most abundant form of tritium, is of particular interest because it is readily taken up by human cells and its irradiation of the cells is spread over a period of days. To approximate the prolonged exposure and the conditions that the cells of an individual would experience in vivo, we irradiated human lymphocytes with tritiated water for 48 h in a 1:1 blood:medium mix. For estimation of the tritium beta-ray dose, a cellular water content of 0.78, based on measurements of human lymphoblastoid cells in culture medium, was used. A modified dose calculation formula was developed for the radiation exposure conditions. A total of 48,014 metaphases (14,482 in irradiated samples and 33,532 in control, unirradiated samples) in human lymphocytes cultured for 72 h after exposure were analyzed for chromosome translocations using fluorescence in situ hybridization. The linear slope (alpha coefficient) of the dose-response curve was measured to be (3.93+/-0.42) x 10(-2) and (5.26+/-0.48) x 10(-2) translocations per cell per gray for complete translocations (tc) and complete translocations plus incomplete translocations [ti(Ab)], respectively, when the data were fitted to a linear model using a weighted least-squares method. The alpha coefficient for tc is significantly lower than that for conventionally measured dicentrics after tritium beta irradiation, but the alpha coefficient for tc + ti(Ab) does not differ significantly from that for dicentrics. This is in agreement with theoretical considerations. The importance of scoring criteria is stressed. The frequency of tc + ti(Ab) is proposed to be a reliable biodosimeter for tritium exposures, and its practical use in a dose reconstruction is presented.

Radiation-induced apoptosis in human lymphocytes: potential as a biological dosimeter.

We have tested the possibility of using apoptosis (programmed cell death) in human peripheral blood lymphocytes as a short-term biological dosimeter. Lymphocytes isolated from whole blood were irradiated in culture with 250 kVp x-rays or 60Co gamma rays. Two assays were used to measure apoptosis in lymphocytes after irradiation: in situ terminal deoxynucleotidyl transferase assay and fluorescence analysis of DNA unwinding assay. Similar qualitative and quantitative results were produced by the assays, supporting the notion that the fluorescence analysis of DNA unwinding assay measured DNA fragmentation associated with apoptosis. Induction of apoptosis in lymphocytes irradiated in vitro was proportional to dose and could be detected following exposures as low as 0.05 Gy. Lymphocytes from individual donors had reproducible dose responses. There was, however, variation between donors. X-ray and gamma-ray exposures induced similar levels of apoptosis at similar doses. The induction kinetics of apoptosis in vitro indicate a maximum is reached about 72 h after irradiation. In conclusion, the in vitro experimental evidence indicates that radiation-induced apoptosis in human lymphocytes has the kinetics, sensitivity, and reproducibility to be a potential biological dosimeter.