Retarded tumor growth and greater longevity in mice after fetal irradiation by 2450‐MHz microwaves
Retarded tumor growth and greater longevity in mice after fetal irradiation by 2450‐MHz microwaves
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胎儿接受 2450 MHz 微波照射后，小鼠肿瘤生长延迟，寿命延长
DOI：
10.1002/jso.2930100603
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发表时间：
1978
影响因子：
2.5
通讯作者：
D. Justesen
中科院分区：
文献类型：
--
作者：
S. Preskorn;W. D. Edwards;D. Justesen
在两项研究的第一项中，48只常规CFW菌株小鼠在妊娠11-14天内，分别以0或35 mW/g的剂量率，每天在子宫内接受2450 MHz微波辐射20分钟。所有48只小鼠在产后第16天植入淋巴网状细胞肉瘤匀浆，然后从第19天开始，它们每天接受36次假辐射或微波辐射。胎儿暴露在辐射中，使母鼠结肠温度平均升高2.24°C，与产后第93天尸检组织学证实的较低肿瘤发生率（13% vs 46%的假辐射小鼠）相关。在第二项研究中，84只CFW小鼠在子宫内接受四种放射治疗；60只小鼠在子宫内进行假辐射，作为对照。未进行产后放射治疗。144只小鼠均于产后第16天植入该匀浆，观察近36个月可触及肿瘤的发生和寿命。在胚胎期受辐射的小鼠中，肿瘤最初的发展率较低，在植入后2.5个月，假辐射和微波辐射小鼠的“摄取”百分比与第一项研究结束时的观察结果相当。随后，辐射小鼠的肿瘤诱导率加快，第四个月后，最终患肿瘤的辐射小鼠百分比（46%）略高于对照组（40%）。在胚胎时期接受辐射的有肿瘤和无肿瘤的动物平均寿命都比相应的对照组长。通过子宫内热疗长期增强免疫能力被认为是延迟肿瘤诱导和提高生存率的原因。
In the first of two studies, 48 mice of the conventional CFW strain were sham‐radiated or radiated in utero for 20 minutes daily by 2,450‐MHz microwaves at a dose rate, respectively, of 0 or 35 mW/g during days 11–14 of gestation. All 48 mice were implanted with a homogenate of a lymphoreticular cell sarcoma on the 16th day postpartum and then, commencing on the 19th day, they underwent a series of 36 daily exposures to the sham‐ or to the microwave‐radiation. Fetal exposure to radiation, which elevated dams colonic temperatures by an average of 2.24°C, was associated with a lower incidence of tumors (13% vs 46% for fetally sham‐radiated mice) as verified histologically at necropsy on the 93rd day postpartum. In the second study, 84 CFW mice received the four radiation treatments in utero; 60 mice were sham‐radiated in utero and served as controls. Postnatal radiation was not administered. All 144 mice were implanted with the homogenate on the 16th day postpartum and then were observed for nearly 36 months for development of palpable tumors and for longevity. Tumors initially developed at a lower rate in fetally radiated mice and 2.5 months after implantation the respective percentages of “takes” in sham‐ and microwave‐irradiated mice were comparable to those observed at termination of the first study. Subsequently the rate of tumor induction in radiated mice accelerated, and after the fourth month the final percentage of radiated mice with tumors (46%) slightly exceeded that of controls (40%). Both tumor‐bearing and tumor‐free animals that had been radiated as fetuses lived longer on the average than respective controls. Long‐term augmentation of immunocompetency by in utero hyperthermia is believed to be responsible for the delayed induction of tumors and for enhancement of survival.