High - The Biological Effects Of Hypoxia Radiotherapy Normal Tissue And The Feasibility Of Clinical Application

It is well known, most of the solid tumors have different degrees of hypoxic cells. This is due to the abnormal construction and fuction of tumor blood vessel and results in the transportation difference of oxygen between tumor and normal tissue.How to utilizing the effection of oxyen is very important in clinical work.The HO+LO irradiation means: after 5 minutes HO (95%O₂+5%CO ₂)inhalation, then switch to LO(10%O₂ + 5%CO₂ + 85%N₂) with irradiation started silmutaneously. This method showed marked radiosensitizing effect to tumor, but not or slight to the normal tissue. For obtaining data for further clinical trials, a series of animal experiments has been conducted.Part 1. Animals which breathing air, HO+LO or HO alone were irradiated, and the histologic changes in the intestinal crypts and the lung fibrosis were observed. The number of regenerating crypts was counted, if a mouse is exposed to X -ray in the dose-range of 10-166y, the numbers of crypts seen in histological section on day 3. 5 postirradiation is decreased below the control group, the dose- survival curves showed, PF=1. 019(Protective Factor. between HO+LO group and AIR) , PF=0.79(between HO group and AIR group). The size of lung fibrosis was 2213 (scale)/lung (AIR), 2310(scale)/lung(HO+LO) and 6460(scale)/lung(HO )respectively. Through the use of lavaging techniques , alveolar surfactant has been elevated post...