绿豆活性肽对小鼠H22肝癌移植瘤的抑制作用

【目的】研究绿豆活性肽对小鼠H22肝癌移植瘤的抑制作用,为绿豆资源的综合利用提供参考。【方法】建立H22鼠肝癌荷瘤小鼠模型,研究不同剂量(400,800和1 600mg/kg)绿豆活性肽对小鼠H22移植性肿瘤的抑制作用及对胸腺、脾脏指数和血液生化指标的影响;采用ELISA测定瘤组织TE端粒酶活性以及Bcl-2、Bax的表达量,初步探究绿豆活性肽的作用机制。【结果】绿豆活性肽对荷瘤小鼠H22肿瘤的生长有明显的抑制作用,给药剂量为1 600mg/kg时抑制率达32.6%;绿豆活性肽能增大荷瘤小鼠胸腺指数和脾脏指数,升高血液中白细胞水平,降低血清中谷草转氨酶、谷丙转氨酸和碱性磷酸酶水平;能显著抑制TE端粒酶活性,减弱Bcl-2表达而增强Bax的表达。【结论】绿豆活性肽对H22荷瘤小鼠有明显的抑瘤作用,且无毒副作用,这可能是通过调节免疫功能、抑制TE端粒酶活性、促进肿瘤细胞Bax表达以及抑制Bcl-2表达而实现的。     

Detection of a cellular oncogene in spontaneous liver tumors of B6C3F1 mice

An active cellular oncogene was demonstrated in hepatocellular neoplasms arising spontaneously in 24-month-old B6C3F1 mice. DNA isolated from the tumorous tissue and transfected into NIH 3T3 cells showed an 82 percent (9 of 11 animals) frequency of foci induction. In contrast, DNA isolated from the surrounding nontumorous hepatic tissue from the same animals and DNA from other 24-month-old B6C3F1 mice without tumors did not cause transformation in the NIH 3T3 cell assay. This strain of mouse is used extensively in carcinogen bioassays, and the observed high frequency of transformation (82 percent, compared to 10 to 20 percent in humans) supports the concept that the B6C3F1 mouse is hypersusceptible to liver tumor development. It also emphasizes the need to further understand the mechanisms of oncogene activation in animals used for long-term studies of toxicity and oncogenicity before evaluating potential human risk.     

Effect of synthetic smong on spontaneous activity of mice

Mice allowed to run in a revolving-drum activity cage are sensitive indicators of air pollution. They respond to the presence of synthetic smog by diminishing their 24-hour activity in the revolving wheels. The redLIction in wheel activity is comparatively greater for larger amounts of smog.     

Increased incidence of tumor metastases in female mice

Most of the tumor cells injected into the tail vein of mice fail to survive at the site of arrest in the lungs, but the percentage of surviving cells is higher in females than in males. The surviving cells, however, grow at a similar and constant rate in both sexes.     

Epithelial origin of polyoma salivary tumors in mice: evidence based on chromosome-marked cells

Trypsin dissection of epithelium from mesenchyme of salivary gland rudiments allows reassembly of glands having either epithelium or mesenchyme selectively marked by T(6) chromosomes. Virus-induced tumors in such glands invariably bear the karyotype of the epithelial component. The method solves a specific example from a group of classical problems concerning epithelial as opposed to mesenchymal origin of neoplasms.     

Influence of uterine site on occurrence of spontaneous cleft lip in mice

It has been found that within the A/Jax strain, embryos in the uterine site nearest the ovary develop cleft lip (with or without cleft palate) significantly more often than embryos in other positions in the uterus.     

Immunological studies on urinary bladder tumors of rats and mice

Human neoplasms derived from the same tissue have been previously shown to have tumor associated antigens characterizing that tissue type. Evidence is now presented for the existence of analogous antigens common to both rat bladder papillomas and carcinomas, and for antigens common to mouse bladder carcinomas. Rats immunized with syngeneic urinary bladder papillomas, then challenged with a methylcholanthrene pellet inserted into the bladder, develop (4 to 6 months later) fewer primary bladder tumors than rats immunized with normal bladder tissue.     

GABA对小鼠离体十二指肠活动影响的研究

采用常规麦氏浴槽灌流法 ,研究了外源性γ -氨基丁酸 (GABA)及其类似物对离体小鼠十二指肠活动的影响 ,结果显示 :GABA明显抑制了离体小鼠十二指肠的自发活动 ,并明显存在剂量依赖性。GABAA 受体阻断剂印防己毒素和GABAB 受体激动剂巴氯芬均明显模拟此效应 ,增强阿托品对十二指肠的抑制作用 ,并逆转酚妥拉明对小鼠离体十二指肠的增强作用 ,所有的药物对肠段的活动频率均无影响。这些结果表明GABA对小鼠离体十二指肠的抑制作用是由GABAA 受体正性作用与GABAB 受体负性作用共同调节的 ,在生理状态下 ,以GABAB 受体的作用为主。GABAB 受体的这种作用可能是通过肠胆碱能系统介导来完成 ,也可能是独立的GABA能系统和 (或 )非胆碱能系统来完成 ,而与肾上腺素能系统无关     

Induction of tumors in mice by genomic hypomethylation

Genome-wide DNA hypomethylation occurs in many human cancers, but whether this epigenetic change is a cause or consequence of tumorigenesis has been unclear. To explore this phenomenon, we generated mice carrying a hypomorphic DNA methyltransferase 1 (Dnmt1) allele, which reduces Dnmt1 expression to 10% of wild-type levels and results in substantial genome-wide hypomethylation in all tissues. The mutant mice were runted at birth, and at 4 to 8 months of age they developed aggressive T cell lymphomas that displayed a high frequency of chromosome 15 trisomy. These results indicate that DNA hypomethylation plays a causal role in tumor formation, possibly by promoting chromosomal instability.     

Puromycin: effect on memory of mice when injected with various cations

Puromycin dihydrochloride neutralized with bases of potassium, lithium, calcium, or magnesium fails to block expression of memory of maze learning in mice, unlike puromycin neutralized with NaOH. This failure may be due to cationic binding at anionic membrane sites with a resultant exclusion of sufficient peptidyl-puromycin to make it ineffective in blocking memory.     

Intracerebral saline: effect on memory of trained mice treated with puromycin

It was shown that puromycin administered to mice 1 or more days after maze-learning blocks expression of memory; the blockage can be removed by intracerebral injections of saline. We present evidence that intracerebral injections of saline are relatively ineffective in restoring memory when puromycin is administered either before or immediately after training; in these two situations puromycin appears to interfere with consolidation of memory.     

芍黄颗粒对小鼠银屑病模型的治疗作用研究

为了探讨芍黄颗粒对小鼠银屑病模型的治疗作用,采用咪喹莫特致小鼠银屑病模型观察芍黄颗粒对银屑病模型小鼠皮损组织病理变化、表皮厚度及皮肤组织中增殖细胞核抗原(PCNA)表达的影响;采用小鼠阴道上皮病理模型及小鼠尾鳞片上皮病理模型观察芍黄颗粒对小鼠阴道上皮有丝分裂及小鼠尾鳞片表皮颗粒层形成的影响。结果表明,与模型组比较,芍黄颗粒各剂量组均能显著减小银屑病模型小鼠皮肤厚度(P<0.05),芍黄颗粒5.0、10.0 g/kg剂量对小鼠背部皮损有改善作用且能显著减少小鼠皮肤组织中PCNA蛋白表达量;芍黄颗粒10.0 g/kg剂量能明显抑制小鼠阴道上皮细胞有丝分裂,对小鼠尾鳞片表皮颗粒层形成有显著促进作用。表明芍黄颗粒可通过影响表皮细胞过度增殖、角化不全而减小皮肤厚度、改善皮损,抑制阴道上皮细胞有丝分裂,促进小鼠尾鳞片表皮颗粒层形成等来治疗银屑病,为银屑病治疗的有效药物。     

6-Mercaptopurine treatment of pregnant mice: effects on second and third generations

The immunosuppressive drug 6-mercaptopurine is embryotoxic in mice. Of the surviving female offspring of mice treated with low doses of 6-mercaptopurine during pregnancy, despite normal body weight and general appearance, many were either sterile or, if they became pregnant, had smaller litters and more dead fetuses as compared to offspring of mothers that had not received the drug.     

肌肽对小鼠抗疲劳作用的试验研究

研究了肌肽对小鼠抗疲劳的作用.每个试验中小鼠分为4组,分别以0,50,100,200mg·kg-1肌肽连续灌胃30d后,观察小鼠负重游泳时间,测定抗疲劳相关生化指标.试验结果表明,中、高剂量组(100,200mg·kg-1)肌肽均能延长小鼠负重游泳时间;小鼠运动后产生的乳酸量、肝糖原消耗量、血清尿素氮、肌肉组织SOD,GSH消耗量和MDA产生量,与对照组相比均有不同程度减少;说明肌肽具有不同程度的抗疲劳作用,并可能与其抗氧化功能有关.     

Leukemogenic activity of filtrates from radiation-induced lymphoid tumors of mice

Cell-free filtrates of x-ray-induced lymphoid tumors of strain C57BL/ Ka mice have elicited, on injection into newborn isologous hosts, a lymphoma incidence of 15 to 19 percent. In control mice of the same subline, the incidence of spontaneous lymphoma is about 1 percent. No leukemogenic activity could be detected in filtrates from thymi harvested at 2 to 32 days following completion of x-ray treatment. Activity was evident at 64 days and was perhaps somewhat greater at 128 days. Serial cell-free passage of filtrates in newborn F(1) hybrid mice resulted in a marked increase in lymphoma incidence (69 percent), coupled with a shortening of the median latency. Supplementary x-irradiation failed to enhance the activity of filtrates after neonatal injection.     

农户土地流转经济福利效应的多维度分析——基于多重选择处理效应模型

使用来自全国25个省2 899个固定观察点农户的调查数据,采用半参数多重选择处理效应模型实证分析土地流转对农户家庭经济福利的多维度影响.结果表明:1)农户土地流转决策受农户家庭内部环境变量和外部环境变量的共同影响,内部环境变量主要包括家庭人均土地规模、生产性固定资产、家庭经营主业、抚养比、户主年龄和受教育程度,外部环境...     

Pituitary tumors in mice after prolonged feeding of synthetic progestins

An enhanced development of pituitary tumors was observed in virgin female mice of the C57 Leaden strain following repeated oral administration of synthetic progestins. This finding appears to parallel the co-carcinogenic enhancement of mammary tumor development elicited in C3H mice treated repeatedly with progesterone.