Mammary cancer induction by 7,12-dimethylbenz(a)anthracene: relation to age

Mammary glands were transplanted from donors treated with 7,12-dimethylbenz(a)anthracene to untreated isologous recipients. Incidence of mammary tumors in mammary grafts from 56-day-old donors was significantly higher than that in grafts from 120-day-old donors, regardless of the age of the recipient hosts. Whent mammary glands were transplanted from untreated donors to isologous recipients that subsequently received 7,12-dimethyl-benz(a)anthracene, a similar difference in tumor incidence in the grafts was observed. In contrast to mammary glands of older females, mammary glands of young adult female rats are highly vulnerable to the carcinogenic effect of 7,12-dimethylbenz(a)anthracene.     

奶牛与黄牛乳腺肥大细胞生物学性质的比较

采用组织化学染色法和免疫组织化学法对同一生理状态的黄牛与奶牛乳腺标本进行处理,比较两品种牛乳腺中肥大细胞的细胞化学性质、所产生的生物活性物质(如NO、5-HT和ER)及乳腺内含P物质(SP)的神经纤维分布特点。结果表明:两种牛乳腺中肥大细胞均为粘膜型肥大细胞,但在同一生理状态下其所产生的生物学物质不尽相同,奶牛与黄牛乳腺肥大细胞的生物学性质存在差异。     

Hormonal stimulation of lactose synthetase in mammary carcinoma

A transplantable rat mammary carcinoma (R3230AC) synthesizes significant quantities of the mammary gland enzyme lactose synthetase in the immature virgin female rat. In this hormonal environment, mammary glands do not synthesize the enzyme. Prolactin further stimulates the enzyme activity in the tumors to levels found only in mammary glands of rats in late pregnancy or during lactation.     

Activation of ras oncogenes preceding the onset of neoplasia

The identification of ras oncogenes in human and animal cancers including precancerous lesions indicates that these genes participate in the early stages of neoplastic development. Yet, these observations do not define the timing of ras oncogene activation in the multistep process of carcinogenesis. To ascertain the timing of ras oncogene activation, an animal model system was devised that involves the induction of mammary carcinomas in rats exposed at birth to the carcinogen nitrosomethylurea. High-resolution restriction fragment length polymorphism analysis of polymerase chain reaction-amplified ras sequences revealed the presence of both H-ras and K-ras oncogenes in normal mammary glands 2 weeks after carcinogen treatment and at least 2 months before the onset of neoplasia. These ras oncogenes can remain latent within the mammary gland until exposure to estrogens, demonstrating that activation of ras oncogenes can precede the onset of neoplasia and suggesting that normal physiological proliferative processes such as estrogen-induced mammary gland development may lead to neoplasia if the targeted cells harbor latent ras oncogenes.     

金黄色葡萄球菌诱发小鼠实验性乳腺炎研究

为建立小鼠乳腺炎模型,本试验选用35只泌乳期BALB/C雌鼠随机分成7组,其中6组于产后8~10 d分别用灭菌生理盐水和不同浓度的金黄色葡萄球菌悬液50μL经乳头管注入到小鼠的第4对(腹部)乳腺内,观察小鼠体温、组织病理学、间质宽度、腺泡壁厚度的变化以及乳腺组织中CFU、TNF-α和IFN-γ含量变化。结果表明:试验组小鼠体温呈现先下降后上升的趋势,以T3组明显;组织病理学显示乳腺上皮脱落,腺泡腔内大量炎性细胞浸润,以嗜中性粒细胞为主,腺泡内空泡减少,间隔增宽,炎症明显。而随着金黄色葡萄球菌用量的加大,乳腺组织的炎症程度加剧。T3组间质宽度高于其他组。与对照组相比,T3组小鼠乳腺组织中腺泡壁厚度、CFU、TNF-α及IFN-γ含量极显著升高(P<0.01)。结果表明金黄色葡萄球菌诱发小鼠试验性乳腺炎模型与炎症的免疫病理过程和炎性反应一致,可用作病理模型使用。     

犬乳腺肿瘤显微和超微病理组织学观察

收集犬乳腺肿瘤自然发生病例31例,用光镜对其进行病理组织学研究,用透射电镜对犬乳腺组织、细胞及一些病原因子的内部和表面超微结构进行细微观察。结果表明,31例犬乳腺肿瘤病例中良性12例,恶性19例。良性乳腺肿瘤以乳腺纤维腺瘤、导管内乳头状瘤多见。恶性乳腺肿瘤的超微结构主要表现为细胞浆内细胞器增多特别是粗面内质网明显增多;核分裂相明显,形态不规则,严重畸形,核固缩明显,核膜不平滑。本试验从亚细胞(细胞器)水平上认识和了解细胞的病变,以期为犬乳腺肿瘤疾病的诊断和治疗提供理论依据。     

重组溶葡萄球菌酶对金葡菌诱导试验性小鼠乳腺炎的防治研究

试验采用重组溶葡萄球菌酶探讨了对小鼠试验性乳腺炎的治疗效果.利用微量肉汤稀释法测定了重组溶葡萄球菌酶时乳源金黄色葡萄球菌(Staphylococcus aureus)的最小抑菌浓度(MIC)和最小杀菌浓度(MBC).将18只泌乳8～10 d的BALB/C母鼠随机分成正常组、阳性对照组和试验组.阳性时照组和试验组母鼠经第4对、第5对乳腺乳头管注入50μL 2.0x105CFU的细菌悬液.试验组攻菌出现症状后,每个乳腺经乳头管注入1 U·mL-1的重组溶葡萄球菌酶稀释液50μL,间隔12 h 1次.观察小鼠的临床症状,测定体温、血常规等指标.接菌66h后,颈静脉放血处死小鼠,取小鼠乳腺进行细菌计数和病理组织切片制作.结果显示,重组溶葡萄球菌酶对金黄色葡萄球菌的MIC值为0.001 U·mL-1,MBC值为0.063U·mL-1.病理组织观察显示,正常组的腺泡结构完整,而阳性对照组的乳腺组织局部被破坏,间质增宽,炎性细胞浸润严重,试验组的组织结构基本正常,有轻度充血.说明重组溶葡萄球菌酶能有效地减少细菌感染,降低组织的损伤程度,对乳腺有一定地保护作用.     

高脂日粮对初情期小鼠乳腺发育的影响及分子机制

【目的】研究高脂日粮对初情期小鼠乳腺发育的影响及可能机制。【方法】选用20只4周龄昆明雌性小鼠,设对照组和高脂日粮组,试验期4周,每周称体质量并统计采食量。试验结束后采集小鼠乳腺并称质量,采用wholemount及HE染色观察小鼠乳腺组织形态结构及导管数量。利用Western blot检测初情期小鼠乳腺组织胰岛素样生长因子1(Insulin-like growth factor1,IGF-1)、增殖相关信号通路关键蛋白蛋白激酶B(Protein kinase B,Akt)、胞外调控的蛋白激酶(Extracellular regulated protein kinase,Er K)以及炎症信号通路关键蛋白Toll样受体4(Toll-like receptor 4,TLR4)、c-Jun氨基末端激酶(c-Jun N-terminal kinase,JNK)和核因子κB激酶抑制剂(Inhibitor of nuclear factor kappa-B kinase,IKK)的表达。【结果】高脂日粮组小鼠采食量极显著低于对照组(P0.01),但在能量摄入方面与对照组无显著差异。高脂日粮组小鼠的体质量增加显著高于对照组(P0.05)。高脂日粮组小鼠在乳腺质量、乳腺质量与体质量的比值上均极显著高于对照组(P0.01)。乳腺组织的whole-mount及HE染色结果表明,高脂日粮组小鼠乳腺导管发育明显被抑制,其乳腺组织的导管数和密度明显降低,乳腺组织的终末乳芽数量也极显著低于对照组(P0.01)。高脂日粮能够显著抑制小鼠乳腺组织IGF-I的蛋白表达以及Akt、Erk和IKK的磷酸化水平(P0.01或0.05),极显著促进小鼠乳腺组织TLR4的蛋白表达(P0.01)和显著促进JNK的磷酸化水平(P0.05)。【结论】高脂日粮能够抑制初情期小鼠乳腺发育,这可能是通过抑制乳腺增殖的相关信号和促进乳腺组织炎症的相关信号来实现。     

乳腺肥大细胞的研究进展

乳腺局部免疫状态存在着特殊性,已引起许多学者的重视。但对其中肥大细胞所起的作用研究则较少。文章结合国内外文献,就乳腺肥大细胞的类型、分布、数量变化和作用等做一概述。     

Lactoperoxidase: identification and isolation from Harderian and lacrimal glands

Investigation of bovine lacrimal and harderian glands revealed the presence of the enzyme lactoperoxidase, which was isolated and purified. A nonheme, iron-containing protein was identified at the same time. Both proteins are present in milk, mammary glands, and salivary glands. Their roles are discussed: The lactoperoxidase may be important in controlling bacterial flora.     

Prevention of Brca1-mediated mammary tumorigenesis in mice by a progesterone antagonist

Women with mutations in the breast cancer susceptibility gene BRCA1 are predisposed to breast and ovarian cancers. Why the BRCA1 protein suppresses tumor development specifically in ovarian hormone-sensitive tissues remains unclear. We demonstrate that mammary glands of nulliparous Brca1/p53-deficient mice accumulate lateral branches and undergo extensive alveologenesis, a phenotype that occurs only during pregnancy in wild-type mice. Progesterone receptors, but not estrogen receptors, are overexpressed in the mutant mammary epithelial cells because of a defect in their degradation by the proteasome pathway. Treatment of Brca1/p53-deficient mice with the progesterone antagonist mifepristone (RU 486) prevented mammary tumorigenesis. These findings reveal a tissue-specific function for the BRCA1 protein and raise the possibility that antiprogesterone treatment may be useful for breast cancer prevention in individuals with BRCA1 mutations.     

Expression of a calcium-mobilizing parathyroid hormone-like peptide in lactating mammary tissue

A survey of rat tissues by RNA analysis, aimed at uncovering the physiological function of the parathyroid hormone-like peptide (PTH-LP) associated with hypercalcemia of malignancy, revealed the presence of a 1.5-kilobase messenger RNA encoding this peptide in lactating mammary glands. PTH-LP messenger RNA is expressed in mammary tissue only during lactation; it appears and disappears rapidly (2 to 4 hours) as a function of the sucking stimulus. The identity of this messenger RNA was confirmed by cloning the rat PTH-LP complementary DNA, which predicts a peptide with strong similarity to the human homolog. Moreover, extracts from lactating mammary tissue stimulated parathyroid hormone-dependent adenylate cyclase. These findings suggest that PTH-LP plays a physiological role in lactation, possibly as a hormone for the mobilization or transfer (or both) of calcium to the milk.     

CpG-DNA对金黄色葡萄球菌诱导的乳腺炎大鼠的保护研究

【目的】建立金黄色葡萄球菌（Staphylococcus aureus）感染的大鼠乳腺炎模型，并观察CpG-DNA对乳腺的保护作用。【方法】18只雌鼠分3组(n=6)，产后72h分别灌注磷酸盐缓冲液（phosphate buffer solution，PBS）（C组）、2×105CFU•ml-1（L组）和2×1012CFU•ml-1 (H组)金葡菌到第四对乳腺内，24 h处死。L组乳腺病变轻微，H组腺泡结构破坏严重，并有大量嗜中性粒细胞（polymorphonuclear neutrophils，PMN）浸润；H组乳腺组织TNF-α、IL-6水平显著上升。选择2×1012CFU•ml-1为诱发剂量观察CpG-DNA对乳腺的保护作用：72只雌鼠分成对照和试验组(n=36)，对照组产后0 h肌注PBS；试验组肌注CpG-DNA，72 h后灌注金葡菌到第四对乳腺内。分别于灌注前（定义为0 h），灌注后8、16、24、48和72 h（n=6）处死。【结果】感染初期试验组乳腺腺泡内PMN较对照组浸润迅速。试验组乳腺组织白细胞介素-6（interleukine-6，IL-6）在16、24和48 h显著高于对照组。CpG-DNA能显著提高0、24和72 h乳腺组织肿瘤坏死因子-α（tumor necrosis factor-α，TNF-α）水平。试验组8、16和72 h的乳腺组织金葡菌数显著低于对照组。CpG-DNA能显著提高乳腺组织中其特异性受体TLR-9（toll-like receptor-9）mRNA表达水平。【结论】CpG-DNA对金葡菌感染诱发大鼠乳腺炎的乳腺有保护作用。     

重组腺病毒介导的猪瘟 E0基因在山羊乳腺中的表达

为使猪温病毒(CSFV)E0蛋白在奶山羊乳腺中得以合成和分泌,一段上游带有信号肽和His标签序列的CSFVE0基因通过腺病毒穿梭载体被插入到腺病毒质粒中,将此重组质粒转染293A细胞包装得到重组腺病毒Ad-hisE0。为证明其有效性,用Ad-hisE0感染293A细胞,实时定量PCR检测显示E0基因的表达显著提高。用Ad-hisE0分别感染牛乳腺上皮细胞和泌乳期山羊乳腺,SDS-PAGE和Western blot分析结果显示出E0蛋白分别位于26ku和48ku处的2条特异性条带。证实构建的腺病毒Ad-hisE0可以介导重组融合蛋白CSFV E0在山羊乳腺中的表达和分泌。     

Sperm penetration of housefly eggs: evidence for involvement of a female accessory secretion

Removal of the paired sex accessory glands associated with the posterior reproductive tract of female houseflies inhibited penetration of the eggs by sperm, but the insemination of females without these glands appeared to be unaffected. The results indicate that either the sperm are "activated" or the permeability of the egg membrane is altered by the secretion of the accessory glands before fertilization occurs.     

山羊乳腺特异性表达慢病毒载体的构建与验证

[目的]构建山羊乳腺特异性表达尿激酶原突变体的重组慢病毒载体,证明其表达的有效性。[方法]将劳氏肉瘤病毒增强子／启动子、复制缺陷型艾滋病病毒（HIV-1）的5’端长重复序列（LTR）、HIV-1ψ卫包装信号、HIVRev反应元件、山羊B-casein调控序列、pro—UKM13、△U3／3’LTR依次连接,构建乳腺特异性表达的慢病毒载体;通过体外转染人乳腺癌细胞系（MCF-7）、仓鼠卵巢细胞（CHO）和泌乳山羊乳腺注射证明其表达有效性。[结果]构建的山羊乳腺特异性表达载体酶切鉴定是正确的;利用该载体转染细胞,采用溶圈法和Westernblot检测证实了其表达的有效性;慢病毒载体注射到泌乳山羊的乳腺,在乳汁中也检测到了尿激酶原的表达。[结论]为在转基因动物的乳腺中表达尿激酶原突变体奠定了基础。     

The Expression of the IGF Family During Mouse Mammary Gland Development

This study was to determine the patterns and levels of IGF family members＇ expression during postnatal mammary gland development. The authors investigated the protein expression profile of the major components of the IGF axis in murine mammary glands. All the proteins examined, IGF- Ⅰ, IGF- Ⅱ, and IGF- Ⅰ receptor （IGF-Ⅰ R） were expressed at greatly different levels and displayed unique expression profiles. IGF- Ⅱ and IGF- ⅠR were always expressed at significantly higher levels than IGF- Ⅰ. IGF- Ⅰwas localized in adipocytes as well as the epithelial and stromal compartments, but just distinctly expressed where mammary cells aggregated to form ducts, in virgins. The IGF- Ⅱ was localized only on the basal layer epithelial cell membranes of ducts and alveoli, with a peak level on the initiation of lactation. The higher level of IGF- ⅠR compared with IGF- Ⅰ was also found in adipocytes as well as in the epithelial and stromal compartments, especially during pregnancy and late lactation. The IGF- Ⅰ R pathway was obviously significant for the development of the mammary parenchyma and stroma. Overall, the comparison of the expression profiles of these different proteins would strongly suggest that they were likely to have different functions throughout the mammary gland development, and it also highlighted the potential interactions and coregulation of the members of this axis. It seems that IGF- Ⅱ was the major local modulator rather than IGF- Ⅰ by an IGF- Ⅰ R-independent pathway, especially for initiation of lactation. This study has demonstrated the importance and complexity of the IGF axis during mammary gland development and provides a valuable resource for future research in this area.     

黄芪多糖对内毒素诱发大鼠实验性乳腺炎的影响

选取40只SD雌性大鼠使之交配受孕。在确定其怀孕后,30只孕鼠随机分成正常对照组、阳性对照组和试验组,每组10只。试验组大鼠每天按100 mg/kg体重灌喂黄芪多糖(APS),直至试验结束,而对照组大鼠灌喂相应体积的生理盐水(PSS)。孕鼠于产后72 h分别用灭菌PSS和50μg大肠杆菌内毒素经乳头管灌注到大鼠第4对乳腺内。灌注后24 h处死大鼠,取乳腺组织和颈静脉血进行指标测定。结果显示,阳性对照组大鼠乳腺组织中肿瘤坏死因子α(TNF-α)浓度、N-乙酰-β-D-氨基葡萄糖苷酶(NAGase)活性,与正常对照组相比显著升高(P<0.05);试验组大鼠乳腺组织中TNF-α浓度、NAGase活性与阳性对照组相比,显著降低(P<0.05)。结果表明,灌喂APS可以抑制乳腺组织内炎性细胞因子TNF-α的过度释放,对内毒素诱发的大鼠实验性乳腺炎有一定的保护作用。     

The Effect ofAdministration of Rutin on Plasma Levels of Estrogen,Prolactin, Growth Hormone and Gene Expression of Their Receptors in Mammary Glands in Ovariectomized Rats

The development of mammary glands, endocrine hormone concentrations and the gene expression of related receptors were measured in ovariectomized virgin rats after adminstration of an estrogen-like plant extract, rutin. Thirty-two ovariectomized virgin Wistar rats were randomly assigned to 4 treatments with 8 animals each: gastric infusion of 2 mL normal saline per unovariectomized rat per day (Sham), gastric infusion of 2 mL normal saline per ovariectomized rat per day (Ova), gastric infusion of 60 mg rutin kg-1 body weight (BW) per ovariectomized rat per day (Ova+Rut), or intramuscular injection of 60 μg estradiol kg-1 BW per ovariectomized rat weekly (Ova+Est). Samples of blood and mammary glands were harvested to determine the levels of estrogen (E2), prolactin (PRL) and growth hormone (GH), and the gene expression of estrogen receptors (ER), prolactin receptors (PRLR) and growth hormone receptors (GHR) with radioimmunoassy (RIA) and RT-PCR technology, respectively. The E2 concentration in plasma and gland tissues from the rats of Ovx+Rut or Ovx+Est was higher than that of Ovx (P<0.05), but the plasma E2 concentration from the rats of Ovx+Rut was lower than that of Sham (P<0.05). The order of the PRL concentration in plasma and gland tissues was Ovx