Hormonal dependence of DNA synthesis in mammary carcinoma cells in vitro

Explants of C3H-mouse and rat R3230AC mammary carcinomas were cultured on chemically defined medium for study of the effects of the hormonal environment on synthesis of DNA. Synthesis in the more slowly proliferating C3H carcinoma cells is stimulated by insulin and inhibited by estrogenic hormones as in normal mammary epithelial cells. Rat R3230AC mammary carcinoma cells can initiate synthesis of DNA independently of insulin or estrogenic hormones. Autonomous growth with respect to these hormonal controls correlates with rapid proliferation, but it is not an essential characteristic of the neoplastic mammary cell.     

通草提取物对奶牛乳腺上皮细胞乳糖合成及相关基因表达的影响

为探讨通草对奶牛乳腺上皮细胞乳糖合成及相关基因表达的影响,采用不同剂量通草提取物处理奶牛乳腺上皮细胞,利用四甲基偶氮唑盐(MTT)法检测乳腺上皮细胞增殖能力,乳糖/半乳糖检测试剂盒(Lactose/D-Galactose (Rapid) Assay Kit)检测乳腺上皮细胞培养液中乳糖含量,实时荧光定量PCR技术检测乳腺上皮细胞乳糖合成相关基因葡萄糖转运蛋白1(GLUT1)、葡萄糖转运蛋白4(GLUT4)、葡萄糖转运蛋白8(GLUT8)、葡萄糖转运蛋白12(GLUT12)、己糖激酶Ⅰ(HKⅠ)、己糖激酶Ⅱ(HKⅡ)、β-1,4-半乳糖基转移酶-1(β-4GALT1)和α-乳清白蛋白(α-LA)基因mRNA表达水平。结果表明,200、400、600μg(生药)·mL-1通草提取物提高奶牛乳腺上皮细胞增殖能力(P<0.05),促进奶牛乳腺上皮细胞合成分泌乳糖(P<0.05),并显著上调细胞GLUT1、GLUT8、HKⅡ、β-4GALT1及α-LA mRNA表达水平(P<0.05),但对GLUT4、GLUT12和HKⅠmRNA表达水平无显著影响(P>0.05)。研究表明,适当浓度通草提取物可提高奶牛乳腺上皮细胞增殖能力,并通过上调乳腺上皮细胞GLUT1、GLUT8、HKⅡ、β-4GALT1和α-LA的mRNA表达,促进乳腺上皮细胞合成乳糖。     

Prolactin receptors in estrogen receptor-deficient mammary carcinoma

We demonstrate for the first time the presence of specific high-affinity receptors for prolactin in rat mammayy carcinoma. There appear to be no significant differences between normal rat mammary tissue and the transplantable, estrogen receptor-deficient R3230AC tumor with regard to the number of binding sites, the affinity of the receptor for prolactin, or the specificity of binding.     

乳腺特异性共表达4种脂肪酸合成酶载体 及其稳转山羊成纤维细胞系的构建

为改善山羊乳品质,创制乳汁中富含n-3不饱和脂肪酸的奶山羊育种新材料,首先构建了一种山羊乳腺特异性表达载体,以实现n-3不饱和脂肪酸合通路中4种脂肪酸合成酶基因(fat-1,fads2,elovl5和scd-1)的共表达。为初步验证该载体的有效性,通过脂质体法转染小鼠乳腺上皮细胞系C127,经G418筛选收集阳性C127转基因细胞,并对其进行反转录PCR(RT-PCR)检测。结果表明,4种基因均可在C127细胞转基因中表达。将该多基因共表达载体转染奶山羊成纤维细胞,通过G418筛选获得了稳定转染的细胞系。PCR结果显示,4个目的基因均成功整合到奶山羊成纤维细胞基因组中。总之,本研究成功构建了乳腺特异性共表达4种脂肪酸合成酶转基因载体及其山羊转基因细胞系,为创制乳腺特异性表达多不饱和脂肪酸的转基因奶山羊奠定了基础。     

Milk and lactose intolerance in healthy Orientals

Nineteen of 20 healthy Oriental adults living in the United States developed abdominal cramps and diarrhea after ingesting an amount of lactose equivalent to that in one quart of milk; 14 reported similar symptoms after one or two glasses of milk; all had consumed milk as infants without having such symptoms. Two of 20 Caucasians tested were intolerant to milk and lactose. Many Orientals therefore may have a genetically determined lactase deficiency that may lead to intolerance to milk. Since lactase deficiency is also common among Negroes, the bulk of the world's adult population is probably intolerant to milk.     

生殖激素对龟类生殖调控的研究进展

迄今为止,已发现有11种生殖激素参与龟类生殖调控。雌二醇和睾酮在促性腺激素释放激素、卵泡刺激素和黄体生成素的调控下主导调控龟类性腺发育、配子生成、交配、产卵及子代性别决定等重要生殖环节。孕酮、前列腺素、精氨酸催产素、皮质酮、甲状腺素和褪黑激素协同调节龟类生殖活动。在人工繁殖方面,使用GnRH等有助于克服龟类繁殖障碍,提高繁殖效率。对生殖激素对龟类生殖活动的调控作用与机理及其应用的研究进展进行了综述。     

Hormonal termination of larval diapause in Dermacentor albipictus

The molting hormone, alpha-ecdysone, and an analog triangle up(7)-5beta-cholestene-2beta,3beta, 14alpha-triol-6-one when applied externally, terminates diapause in larvae of the winter tick, Dermacentor albpictus. This is the first reported hormonal termination of diapause in an arthropod other than an insect.     

Hormonal regulation of growth in unfertilized cotton ovules

Exogenous plant growth regulators can substitute for pollination, fertilization, and subsequent embryo development in cotton. Isolated, unfertilized, immature ovules enlarge in the presence of kinetin, and both enlarge and produce fibers in the presence of indoleacetic acid or gibberellic acid or both. An extract of germinating cotton pollen qualitatively mimics the effect of exogenous hormones.     

激素间相互作用对植物茎伸长生长的调控综述

植物茎的伸长受多种内外因素的调节和控制,其中内部的内源植物激素如赤霉素、生长素等的调控起重要作用,且内源激素不但通过内源激素水平调控,而且还通过激素间的相互作用调节和控制茎的伸长。笔者介绍了各种内源植物激素(如生长素与赤霉素、生长素与油菜素内酯,赤霉素与油菜素内酯,生长素与乙烯等)之间的相互作用调控植物茎的伸长生长的研究概况。     

Hormonal induction of vascular tissue in tobacco pith in vitro

The direct addition of indole-3-acetic acid into sterile-cultured stem pith sections of Nicotiana tabacum through inserted glass pipettes has induced cell division and differentiation where such activity would not normally occur. This evidence lends support to the theory that indole-3-acetic acid is the hormone that limits xylogenesis.     

牛乳超滤透过液中乳糖酶法水解的研究

研究了黑曲霉乳糖酶在牛乳超滤透过液中的应用，探讨了温度、乳糖浓度、酶使用量、时间及ｐＨ对透过液中乳糖水解的影响，通过试验确定了透过液中乳糖酶法水解的优化工艺条件（６０℃、乳糖浓度１２％、酶使用量４．０ｇ／１００ｇ乳糖、时间１６５ｍｉｎ），在此条件下，经１２０ｍｉｎ和１６５ｍｉｎ水解，水解度分别达到８２．４％和９２．１％．     

Chelation of calcium by lactose: its role in transport mechanisms

Lactose, like other sugars and polyols, prevents or delays the precipitation of calcium ion in the presence of bicarbonate buffer. That an uncharged calcium-lactose complex is formed was demonstrated by the use of paper electrophoresis and of calcium-45 as a label for the complex. Enhancement of the intestinal absorption of calcium ion by sugars could result from a complex of low molecular weight.     

大鼠不同时期乳腺组织及血清中孕激素变化规律

探讨大鼠不同时期乳腺组织及血液中孕激素（P）变化规律。选择雌性SD大鼠42只,分为7个时期,每个时期6只：分别为处女期,妊娠第6天、12天、18天,泌乳第6天、12天、18天。分别处死大鼠取乳腺组织及血清,通过放射免疫检测不同时期孕激素含量。结果表明血清中：处女期P含量最低,妊娠后呈现上升趋势,其中妊娠18d与各个时期差异显著（P〈0．05）;泌乳后又呈现下降趋势。7个时期中处女期与其它6个时期差异显著（P〈0．05）;乳腺组织：7个时期整体呈下降趋势,并且处女期与妊娠、泌乳整个时期差异显著（P〈0．05）。结果显示：孕激素在乳腺细胞发育、启动和维持泌乳方面发挥重要作用。     

大鼠不同时期乳腺组织及血液中雌激素变化规律

研究大鼠不同时期乳腺及血液中雌激素变化规律。选择雌性SD大鼠42只,分别为处女期、妊娠前、中、后期,每期间隔6d,泌乳期前、中、后期,每期间隔6d,每期6只。规定时间取各期大鼠乳腺组织及血清。通过放免测各个时期雌激素含量并进行分析。结果表明大鼠血清E2水平中处女期最高,妊娠开始呈现先降后升趋势,而泌乳各时期呈逐渐下降趋势。处女期与其它时期差异显著(P<0.05),整个妊娠期以妊娠后期最高,且差异不显著(P>0.05);泌乳前、中、后期明显高于妊娠期水平(P<0.05);乳腺E2:泌乳前期最高,然后呈现下降趋势,处女期与各期差异显著(P<0.05),泌乳前期明显高于其它时期(P<0.05),而显著高于妊娠中期和后期(P<0.05)。雌激素在维持乳腺发育及启动和维持泌乳方面发挥着重要作用。