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1.
Neoplastic progression is a prolonged and stepwise process, while tumor growth occurs after a series of molecular alterations that culminate in tumorigenesis. The phenotypic changes of transformation in breast carcinogenesis were studied through the use of scanning and transmission electron microscopy. MCF 10F, a spontaneously immortalized human breast epithelial cell line (Soule et al., 1990), was treated with 7,12 dimethylbenz(a)anthracene (DMBA) (Calaf and Russo, 1993) and then transfected with the c-Ha-ras oncogene (Calaf et al., 1995). Treated cells showed a progression in altered morphology, anchorage independency, invasiveness and tumorigenicity in the SCID. Scanning and transmission electron microscopy illustrated that the transformed cells could be distinguished from control cells by the expression of morphological characteristics such as loss of contact inhibition, irregular size and shape, emission of long filopodia and formation of stratified layers. In contrast, control cells showed uniform, flattened and polyhedrical cells, well closely juxtaposed to each other and joined by cytoplasmic interdigitations. Control cells also did not form colonies in agar-methocel, and were not invasive or tumorigenic in SCID mice. These studies showed the progression of breast carcinogenesis by phenotypical changes induced by the carcinogen and the insertion of the c-Ha-ras oncogene.  相似文献   

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Environmental substances may be involved in the etiology of breast cancers. Many studies have found an association between cancer in humans and exposure to agricultural pesticides. Organophosphorous pesticides have been used to control mosquito plagues. Parathion and malathion, organophosphorous pesticides are cholinesterase inhibitors responsible for the hydrolysis of body choline esters, including acetylcholine at cholinergic synapses. Their primary target of action in insects is the nervous system whereby they inhibit the enzyme acetylcholinesterase at synaptic junction. Atropine is a parasympatholytic alkaloid used as an antidote to acetylcholinesterase inhibitors. We have established an experimental breast cancer model, where epithelial cells in the rat mammary gland underwent a stepwise transformation into malignant cells by exposure to pesticides (Cabello et al, 2001). The aim of this work was to examine whether pesticides were able to induce progression of malignant transformation of a human breast epithelial cell line, MCF7. These results showed that parathion and malathion increased PCNA and induced mutant p53 protein expression of MCF7 cells in comparison to controls and atropine inhibited such action. These results indicated that organophosphorous pesticides can induce more changes in this malignant breast cell line, inducing another step in the progression of the transformation process and atropine on the other hand inhibited the effect of such substances.  相似文献   

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Hematolymphoid malignancies of the breast are most commonly neoplasms of mature B-lymphocytes, and may arise as a primary disease or by secondary involvement of a systemic disease. Primary breast lymphomas (PBL) account for 0.04–0.5% of breast malignancies, less than 1% of all non-Hodgkin's lymphomas (NHL), and less than 5% of extranodal lymphomas (Lakhani et al., 2012; Swerdlow et al., 2008; Joks et al., 2011; Barişta et al., 2000; Giardini et al., 1992; Brogi and Harris, 1999; Topalovski et al., 1999).1, 2, 3, 4, 5, 6, 7 Secondary breast lymphomas (SBL) are also rare, with an estimated annual incidence of 0.07% (Domchek et al., 2002; Talwalkar et al., 2008).8, 9 Recognition of breast lesions as hematolymphoid is critical to distinguish them from other entities that can occur in the breast.  相似文献   

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 Breast cancer emerges by a multistep process which can be broadly equated to transformation of normal cells via the steps of hyperplasia, premalignant change and in situ carcinoma. The elucidation of molecular interdependencies, which lead to development of primary breast cancer, its progression, and its formation of metastases is the main focus for new strategies targetted at prevention and treatment. Cytogenetic and molecular genetic analysis of breast cancer samples demonstrates that tumour development involves the accumulation of various genetic alterations including amplification of oncogenes and mutation or loss of tumour suppressor genes. Amplification of certain oncogenes with concomitant overexpression of the oncoprotein seems to be specific for certain histological types. Loss of normal tumour suppressor protein function can occur through sequential gene mutation events (somatic alteration) or through a single mutational event of a remaining normal copy, when a germline mutation is present. The second event is usually chromosome loss, mitotic recombination, or partial chromosome deletion. Chromosome loci 16q and 17p harbour tumour suppressor genes, which seem to be pathognomonic for the development or progression of a specific histological subtype. There are an overwhelming number of abnormalities that have been identified at the molecular level which fit the model of multistep carcinogenesis of breast cancer. When the functions of all of these genes are known and how they participate in malignant progression, we will have the tools for a more rational approach to diagnosis, prevention and treatment. This review deals only with the factors that are involved in the conversion of a normal breast cell into a malignant cell rather than those required for invasion and metastases. A key critical long-term step in the molecular analysis of breast cancer will be to link the specific molecular damage with the effects of environmental carcinogens. Received: 24 October 1996 / Accepted: 11 February 1997  相似文献   

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Breast cancer is one of the common malignant diseases among women in Japan as well as in western countries, and its incidence continues to increase. Normal mammary duct epithelial cells exhibit a well-organized apicobasal polarity, which forms the basis for their specific structure and function. Although the loss of epithelial cell polarity is one of the major changes that occur during the progression of tumor cells, including breast cancer, the underlying molecular mechanisms for this, as well as their relationship to other changes such as increased proliferation and metastasis, remain to be elucidated. The atypical protein kinase C lambda/iota (aPKC lambda/iota) is involved in several signal transduction pathways, including the establishment of epithelial cell polarity. In this study we evaluated the expression and localization of aPKC lambda/iota in breast cancer by immunohistochemistry and compared our findings with the clinicopathologic factors associated with the tumor specimens. We detected aPK Clambda/iota protein overexpression in 88 of the 110 breast cancer cases (80.0%) under study, expect for decreased expression in a few cases. The immunoreactivity of aPK Clambda/iota was generally weak in ductal carcinoma in situ, but strong in invasive ductal carcinoma (IDC; P = .022). The correlation between apical or cytoplasmic aPKC lambda/iota localization and tumor pathologic type (ie, atypical ductal hyperplasia, ductal carcinoma in situ. or IDC) was also demonstrated (P < .001). These results thus indicate that the normal apicobasal polarity is lost upon the progression of a breast lesion to IDC. This is also the first evidence to show aPKC lambda/iota overexpression in breast cancer and demonstrates that its localization is associated with the trend of pathologic type of the tumor.  相似文献   

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Iacovacci et al. [(1997a) Research in Virology 148:147-151] described that the euploid diploid cells, of the normal human bone marrow-derived lymphoblastoid B-cell line TO.FE., are susceptible to hepatitis C virus (HCV) infection and support long term virus production. Transmission electron microscopy described some steps of HCV replication cycle in this in vitro infected cellular system [Serafino et al. (1997) Research in Virology 148:153-159]. In the present study, in order to identify the intracellular sites involved in HCV replication, the ultrastructural changes associated with infection in TO.FE. cells were correlated with the subcellular localisation of structural and nonstructural viral proteins. Transmission electron microscopy and confocal microscopy data indicate that these viral proteins appeared located in the Golgi apparatus and endoplasmic reticulum, suggesting an active involvement of these compartments in viral assembly and morphogenesis. Furthermore, transmission and scanning electron microscopic observations on cultures infected chronically support the hypothesis that these cellular compartments may serve as starting sites of the morphological changes associated to viral infection and replication, leading to cell-cell fusion, syncytia formation, and finally lysis of infected cells and virus release.  相似文献   

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Cystic hypersecretory intraductal carcinoma is an unusual, cystic form of intraductal breast carcinoma affecting middle-aged women. Cytopathologists have rarely encountered this lesion, with only 2 other cases having been previously reported (Colandrea et al., Arch Pathol Lab Med 1988:112:560-563; Kim et al., Acta Cytol 1997;41:892-896). In our cases, the cytologic findings of both air-dried, Diff-Quick-stained and ethanol-fixed, Papanicolaou-stained smears are presented. The cytologic hallmarks of this entity include the presence of a few scattered epithelial cells with bland nuclear morphology in a background of extensive, amorphous, pink-staining material. Cytomorphologically, the differential diagnosis includes other entities containing pink-staining material such as colloid carcinoma, mucocele-like lesion of the breast, and benign fibrocystic change.  相似文献   

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高强度聚焦超声热疗技术的发展和应用   总被引:2,自引:0,他引:2  
高强度聚焦超声热疗技术以其微创、精确度高、副作用小且并发症少而被应用于临床治疗。目前,该技术主要用于前列腺癌、肝癌、原发性恶性骨肉瘤及乳腺癌等疾病的治疗。主要论述高强度聚焦超声热疗的现状、临床应用及进展。  相似文献   

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Liede A, Metcalfe K, Offit K, Brown K, Miller S, Narod SA, Moslehi R. A family with three germline mutations in BRCAl and BRCA2 . Clin Genet 1998: 54: 215–218. 0 Munksgaard. 1998
Several cancer genetics centres offer testing for specific BRCAl and BRCAZ mutations to Ashkenazi Jewish individuals with a family history of breast and ovarian cancers. Testing involves screening for three common mutations found in this population, namely BRCA I 185delAG, 5382insC and BRCA2 6174delT (Struewing et al., Nat Genet 1995: 11: 198–200; Roa et al., Nat Genet 1996: 14 185–187; Oddoux et al., Nat Genet 1996: 14 188–190). We have identified a large Ashkenazi Jewish kindred (W9170) with ten cases of breast cancer and four cases of ovarian carcinoma. Initially, mutation analysis for this family identified a BRCAl 185delAG mutation in the proband diagnosed with three separate primary cancers of the breast, ovary and colon. Another individual in this family diagnosed with two primary cancers of the ovary and breast, was identified as having a second mutation, BRCA I 5382insC. Subsequent work found that two sisters (cousins of the proband), both diagnosed with carcinoma of the breast, had a third mutation, BRCAZ 6174delT. These three mutations have previously been found to be more common in the Ashkenazi Jewish population (References as above). The identification of all three mutations in one family, raised new implications for the manner in which testing and counselling should be offered. In our opinion, Ashkenazi Jewish individuals in breast-ovarian cancer families should be offered complete testing for the three common Ashkenazi Jewish mutations regardless of previous identification of one of these mutations in the family.  相似文献   

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Astrocytes have been proved to play a critical role in neuromodulation, neuroprotection, pH maintenance, axon guidance control during development, homeostasis preservation and blood brain barrier maintenance in the CNS (Kimmelberg and Norenberg, 1989). Quantitative changes in the expression of glial fibrillary acidic protein (GFAP), a cytoskeletal intermediate filament protein exclusively expressed in astrocytes (Bignami et al, 1972), have been observed after administration of alcohol (Framke, 1995), morphine (Beitner-Johnson et al., 1993), amphetamine and its derivates (Aguirre et al., 1999), cannabinoids (Suarez et al., 2000), nicotine (Janson and Moller, 1993), caffeine (Marret et al., 1993) and prenatal exposure to cocaine (Clarke et al., 1996; Nassogne et al., 1998). However, the general astrocytic response to drugs of abuse is still far from being defined. In the present study we examined the in vivo astroglial response to cocaine in mouse dentate gyrus, the hippocampus being a common target of neurotoxic agents (Walsh and Emerich, 1988) which has a prominent effect on learning and memory processes (Eichenbaum et al., 1992). Quantitative changes in immunoreactivity of GFAP were investigated 24 h after acute and repeated daily administration of intraperitoneal cocaine (20 mg/kg). Drug-induced morphological alterations and spatial distribution of astrocytes were evaluated by means of confocal microscope. The results show that, compared to control animals, GFAP expression is two-fold enhanced after a single cocaine injection, still significantly higher after seven consecutive daily administrations, but not statistically different after prolonged (14 days) drug treatment. Moreover, morphological and morphometric analyses reveal significant modifications in astrocytic numbers, cell size and shape complexity. These data demonstrate that in mouse dentate gyrus, cocaine exposure differently affects the expression of GFAP and induces strong changes in astrocytes proliferation rate and cell morphology. Taken together, our findings provide the first in vivo quantitative and qualitative evaluation of astrocytic response to several regimens of cocaine in adult animals brain.  相似文献   

15.
Lin TC  Lin FH  Lin JC 《Acta biomaterialia》2012,8(7):2704-2711
Hyperthermia has been reported to be an effective cancer treatment modality, as tumor cells are more temperature-sensitive than their normal counterparts. Since the ambient temperature can be increased by placing magnetic nanoparticles in an alternating magnetic field it has become of interest to incorporate these magnetic nanoparticles into biodegradable nanofibers for possible endoscopic hyperthermia treatment of malignant tumors. In this preliminary investigation we have explored various characteristics of biodegradable electrospun chitosan nanofibers containing magnetic nanoparticles prepared by different methods. These methods included: (1) E-CHS-Fe(3)O(4), with electrospun chitosan nanofibers directly immersed in a magnetic nanoparticle solution; (2) E-CHS-Fe(2+), with the electrospun chitosan nanofibers initially immersed in Fe(+2)/Fe(+3) solution, followed by chemical co-precipitation of the magnetic nanoparticles. The morphology and crystalline phase of the magnetic electrospun nanofiber matrices were determined by scanning electron microscopy, transmission electron microscopy, selected area electron diffraction, and X-ray diffraction spectroscopy. The magnetic characteristics were measured using a superconducting quantum interference device. The heating properties of these magnetic electrospun nanofiber matrices in an alternating magnetic field were investigated at a frequency of 750 kHz and magnetic intensity of 6.4 kW. In vitro cell incubation experiments indicated that these magnetic electrospun nanofiber matrices are non-cytotoxic and can effectively reduce tumor cell proliferation upon application of a magnetic field.  相似文献   

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Extracellular matrix metalloproteinase inducer (EMMPRIN), a glycoprotein present on the cancer cell plasma membrane, enhances fibroblast synthesis of matrix metalloproteinases (MMPs). The demonstration that peritumoral fibroblasts synthesize most of the MMPs in human tumors rather than the cancer cells themselves has ignited interest in the role of EMMPRIN in tumor dissemination. In this report we have demonstrated a role for EMMPRIN in cancer progression. Human MDA-MB-436 breast cancer cells, which are tumorigenic but slow growing in vivo, were transfected with EMMPRIN cDNA and injected orthotopically into mammary tissue of female NCr nu/nu mice. Green fluorescent protein was used to visualize metastases. In three experiments, breast cancer cell clones transfected with EMMPRIN cDNA were considerably more tumorigenic and invasive than plasmid-transfected cancer cells. Increased gelatinase A and gelatinase B expression (demonstrated by in situ hybridization and gelatin substrate zymography) was demonstrated in EMMPRIN-enhanced tumors. In contrast to de novo breast cancers in humans, human tumors transplanted into mice elicited minimal stromal or inflammatory cell reactions. Based on these experimental studies and our previous demonstration that EMMPRIN is prominently displayed in human cancer tissue, we propose that EMMPRIN plays an important role in cancer progression by increasing synthesis of MMPs.  相似文献   

17.
Zearalenone (ZEA) is a mycotoxin produced by some Fusarium species. ZEA often occur as a contaminant in cereal grains and animal feeds. Human exposure occurs by ingestion of mycotoxin-contaminated products and can cause serious health problems. It was established that this mycotoxin have an hepato, haemato, immuno and genotoxic properties (Maaroufi et al., 1996, Lioi et al., 2004). While most ZEA toxic effects have been quite well investigated, more studies are required to elucidate its mechanisms of toxicity. In order to better understand the molecular mechanisms involved in ZEA toxicity, we used a proteomic approach, to assess the early changes in protein expression initiated by ZEA in HepG2 cells. Our results showed that, after 8 h of exposure, cells were still viable and showed a significant change in a number of proteins involved in diverse cellular processes. These changes may provide the early affected functions and yield further insight into mechanisms underlying the involvement of mycotoxin-induced diseases.  相似文献   

18.
AIDS as immune system activation: a model for pathogenesis   总被引:3,自引:1,他引:2       下载免费PDF全文
Epidemiological evidence has implicated the human immunodeficiency virus (HIV) as the etiological agent of the acquired immunodeficiency syndrome (AIDS) (Barré-Sinoussi et al., 1983; Sarngadharan et al., 1984; Kitchen et al., 1984; Levy et al., 1984). Primary infection with HIV is accompanied by an acute flu-like illness followed by a relatively long period of asymptomatic infection, the delayed appearance of lymphadenopathy and a progressive decline in immune responsiveness. Eventually, significant reduction in T4 cell number occurs along with susceptibility to a variety of opportunistic infections. It is generally accepted that this lymphotropic retrovirus causes the depletion of the helper class of T lymphocytes (T4) by direct cytopathic effects and/or the induction of autoimmune killing of T cells (Fauci, 1987). Few objections have been raised to this model despite abundant experimental evidence that viraemia and the number of infected T cells are limited and constant throughout disease progression (Levy et al., 1985; Shaw et al., 1984; Harper et al., 1986; Duesberg, 1987). We believe that the current model for HIV-induced pathology is unsatisfactory. A hypothesis is advanced in which progressive immunodeficiency is caused by indirect mechanisms without widespread T cell infection, direct virus-mediated cytopathic effects, or autoimmunity. We propose that the latency of AIDS is not due to delayed viral expression and growth but rather to the accumulation of insults to an immune system with abnormal regulatory mechanisms induced by HIV infection of macrophages.  相似文献   

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目的 通过透射电子显微镜技术观察体外培养的嵌合体丙型肝炎病毒(HCV)感染Huh7.5细胞后胞内病毒颗粒的形态学特征及细胞内部超微结构的变化.方法 将含有全长HCV嵌合基因组的质粒pFL-J6/JFH体外转录为HCV RNA,电穿孔转染至Huh7.5细胞,实时定量聚合酶链反应(qRT-PCR)测定培养上清中病毒数量;间接免疫荧光检测病毒蛋白的表达;收取转染后细胞培养上清感染原始Huh7.5细胞,制作超薄细胞切片,透射电子显微镜技术观察被感染细胞中病毒颗粒的形态学特征及细胞超微结构的变化.结果 qRT-PCR显示不同时间点收取的转染后细胞培养上清中含有高水平的病毒量;间接免疫荧光显示病毒NSSA非结构蛋白高表达;透射电子显微镜观察到被感染的Huh7.5细胞内含有大量有包膜或无包膜的病毒样颗粒,细胞质内部分膜性细胞器增生,出现黄病毒科病毒感染后特征性结构及某种未知结构等.结论 体外培养的嵌合体HCV具有HCV颗粒的形态学特征,并能够有效感染人源性肝细胞Huh7.5.  相似文献   

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Uncombable or spun-glass hair (pili trianguli et canaliculi) is an uncommon condition in which the hair is "unmanageable" and has a distinct appearance on scanning electron microscopy. The hair is usually grossly abnormal in infancy and childhood, but may become normal later in life. Although dominant inheritance has been observed, most cases have been sporadic. Both recessive and dominant transmission with incomplete penetrance have been suggested as modes of inheritance. We report the occurrence of this condition in a young girl, her brother, and her father. Although the proposita and her brother had characteristically uncombable hair, their father appeared normal and denied any history of hair abnormality. However, the characteristic hair morphology was observed on scanning electron microscopy in all 3 relatives, documenting dominant transmission and complete penetrance of the gene in this family.  相似文献   

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