- 期刊
開發上皮集落鑑定系統以評估豬皮膚之放射線敏感度
Development of an Epidermal Microcolony Assay System for Measurement of Radiosensitivity in the Pig Skin
摘要
目的：利用與人類皮膚非常相近之豬皮膚。發展最為精確可靠且具有量化功能的豬上皮微小集落鑑定技術，以提供皮膚放射線傷害之良好研究模式。 材料與方法：平均體重約為30公斤之白色雄性Landrace豬隻於適應飼養環境2周以上，並同時於左側腹面利用刺青方法劃出4×4公分範圍，於每一照野間隔5公分情況下，先行給予吸入麻醉並分別照射 22.5,25.0及27.5Gy之3MeV電子射線劑量。照射後第14天起利用色差計(chromometer)測定紅斑反應程度並於△E值達到高峰之後一天進行皮膚取樣。切下中間2×2公分組織經過固定、水解、DNA染色。清除真皮層內所含結締組織後。將僅剩的上皮層予以封片，並利用光學顯微鏡計數每平方公分大於50個細胞的集落數目，並進一步求得劑量反應曲線及D(下標 0)值。 結果：利用色差計所測得之值可見，皮膚紅斑反應高峰期的△E值約介於5至8左右，且此高峰值僅存在約2天時問。多數豬隻△E值之高峰期約介於照射後玲至21天之問。本技術獲取之集落影像呈現出細胞核染色深，排列規則而緊密。同時可見分裂細胞它與周圍市細胞形成強烈對比，因此計讀容易。所獲取之活存曲線D(下標 0)。值為3.05±0.38Gy。 結論；大豬隻皮膚放射線研究之重要性人人皆知，但基於人力、物力、時問及精確性之考暈，仍舊必須針對照射劑量準確度，最適合的取樣時機，皮膚組織之固定，染色及上皮組織之分離。等做最佳的組合。 方能成為良好的傷害鑑定模式。研究結果證實本技術之優越性及實用陸。相信對於皮膚早、晚期放射線傷害之研究必將引起廣泛的注意或應用。
並列摘要
Purpose: To develop an accurate and quantitative measurement technique of the pig epidermal micro-colonies as an ideal model system for radiation research on the skin. Materials and Methods: White male pigs weighing about 30kg were kept in a separate cage indoors and quarantined for at least 2 weeks before irradiation. All animals were tattooed on the left flank with Indian ink at size of 4×4 cm and a gap of 5cm between the fields. Prior to irradiation the animals were anaesthetized with a gas mixture. Radiation dose was given at 22.5, 25.0 and 27.5Gy using 3MeV electrons. At 14 days after irradiation, a chromometer was used to determined the degree of erythema, the skin samples were taken on the next day after erythema reached the maximum. Only 2×2cm skin samples were cutted, fixed, hydrolysed, stained, connective tissues removed, epidermal sheets prepared and mounted for final colony counting under the microscope. Furthermore, a dose..response curve and D(subscript 0) value were obtained. Results: The maximum AR value were between 5 to 8, this peak value only lasts for about 2 days. Normally the maximum SE value appeared between days 18 to 21. The pattern of the present epidermal microcolonies appears to have dark nuclear stain, regular and compact cellular arrangement with few mitotic cells, which forms strong contrast to the surrounding cells. The D(subscript o) value deduced from the surviving curve was 3.05±0.38Gy. Conclusions: The importance of pig skin in radiation research is known for many years by many experts. However, the development of an optimal assay system has to rely on the best combination of the accuracy of radiation dose delivery, optimal sampling time, skin fixation, staining and epidermal sheet separation etc. The present results proved it's superiority and applicability in terms of the assay technique. We believe that this technique will draw much attention to the people who study early and late radiation injury on the skin.