小鼠粒细胞白血病细胞体外细胞系L_(833)的建立及其生物学特性的研究

本文用小鼠可移植性粒细胞白血病瘤株L_(801)的骨髓细胞,经体外培养建立了粒细胞白血病细胞系(株),定名为L(833)。三年来在体外已传至280余代,细胞生长迅速稳定,经不同途径动物接种致瘤率均为100％。经细胞学、细胞化学、病理学和超微结构等检查,均证明本细胞系(株)仍为粒细胞白血病细胞。L_(833)细胞系细胞染色体分析证明仍然是亚二倍体,众数39条,Y染色体丢失和存在一个标记染色体。L_(833)-A和L_(833)-B(利用半琼脂法分选出的细胞集落定名为A和B)染色体除了上述变化外,还各自存在一个标记染色体。本系细胞对所用各类抗癌药物均有不同程度的敏感性。对辐射(γ线)也很敏感,L_(833)和L_(833)-A的D_0值分别为98.8和104.9 rad。其结果和L_(801)基本是一致的,它的建立不但对于深入研究白血病和其药物筛选等有重要意义,而且利用体外瘤株进行有关研究更直观、经济和易于进行精确定量研究。     

ESTABLISHMENT OF A MODEL OF TRANSPLANTABLE MYELOCYTIC LEUKEMIA (L_(801)) IN LACA MICE

A transplantable myelocytic leukemia model of LACA mice, designated by the name of L_(801), was established by intravenous injection of spleen cell suspension from mice with radiation-induced myclocytic leukemia into mice of the same strain.Until now, for more than three years, the L_(801) has maintained stable and rapid growth and has been reproduced for over 130 serial passages. The incidence of leukemia in inoculated animals was approximately 100% and mean survival time was 10.9±2.1 days. The L_(801) is of myelocytic type which has been determined by cytological, cytochemical, pathological and ultrastructural observations. Its karyotype was hypodiploid, characterized by modal number of 39, loss of Y chromosome and an abnormal huge marker chromosome. The cell cycle duration of the L_(801) was 16 h. C-type viral particles were observed under the electron-microscope. The L_(801) was sensitive, to varying extents, to various anti-tumor agents.We presume that the L_(801) is a useful tool in studies on me     

STUDY ON LATE EFFECTS OF RADIOIODINE ON RATS

This paper describes the results observed on 850 male Wistar rats for two years after intraperitoneal injection with ~(131)I, ~(132)I or ~(125)I of different radioactivities. The incidence of thyroid malignant tumor was 45.8% when the dose absorbed by the thyroid gland was 7.8 Gy in the ~(131)I groups, and even tumors of lung and soft tissue, and malfunction of kidney and immune organs could be elicited when the radioiodine was overdosed. Both ~(132)I and ~(125)I have their optimal carcinogenic dose ranges and optimal doses of carcinogenesis. As the dosage decreases to a certain level, a low-limit dose incapable of inducing cancers may be present. ~(131)I induced mainly papillary and mixed type carcinomas, ~(132)I chiefly follicular and undifferentiated type carcinomas, while ~(125)I induced follicular and medullary carcinomas. The paper also discusses cytochemical DNA quantitative assays of different histological types of thyroid gland carcinomas, holding that reference to such data as decreasing serum     

ESTABLISHMENT AND BIOLOGICAL PROPERTIES OF MOUSE GRANULOCYTIC LEUKEMIC CELL LINE-L_(833)

A granulocytic Leukemic cell line, called L_(833), has been established through culturing in vitro frommouse bone marrow of transplantable granulocytic leukemia. More than 280 passages have been performedin 3 years. Cell growth has been rapid and stable. Incidence of tumour formation was 100% with variousroutes of inoculation. The nature of granulocytic leukemia was confirmed by examination of cytology,cytochemistry, pathology and ultrastructural changes. Analysis proved chromosomes to be hypodiploid with model number of 39, loss of chromosomes, andpresence of a marker. Besides the chromosomal change as mentioned above, both L_(883-A) and L_(833-B)derived from colonies formed from the L_(833) cells cultuerd in semi-solid agar medium, have their ownmarker. The cell line was sensitive to various types of antitumour agents in varying degrees. It was alsosensitive to ionizing radiation. D_0 values of L_(833) and L_(833-A) cells were 98.8 and 104.9 rad, respec-tively. The results were similar to that of L_(8     

Studies on Mechanisms and Blockade of Carcinogenic Action of Female Sex Hormones

Tumours of mice are induced by administration of Inj. Hydroxyprogesteroni Caproatis Co. (EP) in a practical subthreshold dose of carcinogenesis or 2. 5-5 times the human contraceptive dose (simply referred to as 2. 5- to 5-fold dose) combined with whole-body 0. 5 Gy gamma-ray irradiation. Malignant transformation of Syrian golden hamster embryo (SHE) cells is also induced by 5-fold dose of EP combined with 0. 3 Gy gamma-ray irradiation in vitro, thereby indicating that synergistic carcinogenesis can be obtained by combined use of physical and chemical carcinogens.The mechanisms of synergistic carcinogenesis have been further explained by cytogenetics, damage extent of the target cell DNA and production of free radicals. The Chinese traditional medicine with antioxidat-ing effect (Sulekang Capsule, SC), food additive--butylated hydroxyanisole (BHA) and green tea can effectively inhibit the carcinogenic effect of EP or EP combined with gamma rays in mice. They all have marked ability to scavenge or remove     

EXPERIMENTAL STUDIES ON THE LATE EFFECTS OF FEMALE SEX HORMONES

Inj. Hydroxyprogesterone Co. (EP) was injected i.m. into female Wistar rats, different strains of mice of both sex and Syrian golden hamsters with doses of 5--100 times the human contraceptive dose once or twice a month for 10--32 times. In some experiments EP was combined with whole-body 3 Gy gamma ray radiation once or twice. Results show that EP has obvious carcinogenicity and can enhance the gamma ray carcinogenicity, thereby increasing the tumor incidence or the ratio of malignant to benign turnouts. Carcinogenic mechanisms of EP have also been studied.     

雌性激素致癌作用的机制和对其阻断的研究

本文从实际致癌阈剂量下的小剂量复方己酸孕酮注射液(EP),折合成人的2.5倍和5倍剂量和γ线0.5Gy照射联合诱发了小鼠肿瘤;EP5倍量和γ线0.3Gy体外照射联合诱发了SHE细胞的恶性转化,进一步说明理化致癌因子联合应用可达到协同致癌作用。从细胞遗传学、靶细胞DNA损伤程度和自由基的产生进一步阐明两者协同致癌的机制。具有抗氧化作用的中药(苏乐康)、食品添加剂——BHA和绿茶等有效地抑制了致癌作用,同时观察到它们均具有较强的捕获或清除自由基、减轻DNA损伤的作用。     

雌性激素的远后效应实验研究

本文用复方己酸孕酮注射液(EP)给雌性大鼠以及不同品系雌性和雄性小鼠肌内注射,剂量按体重折合成人的5—100倍,每月注射1次或2次,共10—32次。部分实验与钴-60γ线联合应用,全身照射3Gy,1次或2次,观察其致癌和有害的非致癌效应。实验结果表明,EP具有明显的致癌作用;与γ线联合应用明显加重γ线的致癌作用。本文对EP的致癌机制也进行了讨论。     

放射性碘核素对大鼠远后效应的研究

本文报道用850只雄性Wistar大鼠,腹腔注射不同强度的~(131)I,~(132)I,~(125)I后观察二年的结果。当~(131)I甲状腺吸收剂量为7.8GY时,甲状腺恶性肿瘤的发生率为45.8％,注入强度过大时,还可引起肺、软组织的肿瘤及肾脏、免疫器官的损伤。~(132)I和~(125)I都显示有最适致癌剂量范围及最适致癌剂量,当剂量降到某一数值时,可能存在一个不致癌剂量的实际下限值。~(131)I主要诱发甲状腺乳头状腺癌和混合癌,~(132)I主要为滤泡性腺癌和未分化癌,~(125)I主要为滤泡性腺癌和髓样癌。本文还讨论了甲状腺不同组织学类型癌细胞DNA定量细胞化学测定结果,认为,如参考血清中T_4降低,TSH升高,CIC升高等变化,它们对甲状腺癌的早期诊断可能是有帮助的。