Radiation effects on the skin and subcutaneous tissues : implications for protection criteria and the treatment of localised accidental over exposures

Ziel

A study was carried out to define the target cells for acute epidermal reactions following alpha and beta irradiation of varying areas of mouse skin. The moist desquamation reaction, driven by basal cell damage and basal cell kinetics, peaked at 20-25 days and was resolved by 35-40 days. The reaction was area and energy dependent with a significant role in repair being played by basal cell migration from the edges of the irradiated field and from surviving hair follicle living cells. A second reaction termed acute ulceration, involving loss of epidermal and dermal cells by interphase death, occurred at 5-6 days. Acute epidermal necrosis involving interphase death of epidermal but not dermal cells occurred 6-7 days after high doses of a weak beta emitter. Alpha exposure gave a dose related response for erythema and discolouration but did not induce severe skin lesions because of lack of penetration to the basal layers.
A study was also carried out into the effects of external gamma exposure of the whole body and localised beta exposure of the skin. Minimal synergy was found when the radiations were given simultaneously, but, prolonging the immune suppression by whole body gamma radiation 7 and 14 days after the localised beta dose significantly prolonged the repair of skin lesions.
Studies of the skin cancer proneness of albino and pigmented strains of mice to ionizing radiation showed that the albino mice were 4-5 times more cancer prone. It was found that over 95% of tumours in albino mice were of dermal origin compared to 60% of tumours in pigmented mice.
The contribution of the Department of Radiology will be to concentrate on the effects of different energy radiations on mouse skin, the objective being to:
Define the anatomical site(s) of the target cell(s) for acute epidermal reactions for different absorbed doses and depth dose distributions;
To clarify any such synergism, mice will receive either desquamative or ulcerative doses of beta radiation to the skin coupled with sublethal whole body Cobalt60 doses (2.8 Gy) to simulate the conditions of a peacetime reactor accident. The effect of haemopoietic hypoplasia on the severity and duration of the skin lesions will be monitored.
Develop appropriate models for radiation-induced skin cancer in several mouse strains with different anatomical skin types. This will be the major study of this contributory laboratory and it arises from a collaborative project partially funded by the CEC RTD Programme (Contract Number B16-057-UK) which involved irradiation of mice with a wide range of beta doses (2-1000 Gy surface dose) using plane uniform 8 cm{2} sources of thulium170 or nonuniform arrays of 8 or 32 (2mm diameter) sources distributed over a same 8 cm{2} area.

Wissenschaftliches Gebiet

Programm/Programme

FP2-RADPROT 7C - Specific multiannual research and training programme (Euratom) in the field of radiation protection, 1990-1991

Thema/Themen

Data not available

Aufforderung zur Vorschlagseinreichung

Data not available

Finanzierungsplan

CSC - Cost-sharing contracts

Koordinator

St Bartholomew's Hospital Medical College

EU-Beitrag

Keine Daten

Adresse

Charterhouse Square
EC1M 6BQ London
Vereinigtes Königreich

Gesamtkosten