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Query: UMLS:C0027651 (tumor)
 685,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The FT37/1 tumor line induced by Agrobacterium tumefaciens on flax epicotyls contains 22-24 copies of the T-DNA encoded nopaline synthase gene per cell. All the gene copies are methylated to some extent but the methylation is not uniform, nor does it reflect the methylation level of the flanking plant DNA. This extensive methylation correlates with an extremely low level of expression of the nopaline synthase gene. Treatment of the tumor line with the in vivo demethylating drug 5-azacytidine at a concentration of 3 X 10(-5) M, resulted in the demethylation of, on average, one copy of the nopaline synthase gene per cell. This demethylation was paralleled by an increase in the transcription of the gene and indicates that cytosine methylation is capable of suppressing the expression of plant genes in vivo.
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PMID:The role of cytosine methylation in the control of nopaline synthase gene expression in a plant tumor. 619 16

The aim of our study was the detection and the characterization of submacroscopic foci of infiltrating carcinoma in the human female mammary glandular tree collateral to clinical cancer. Accordingly, we analyzed 100 breasts surgically removed by radical mastectomy. Five thin slices per case were analyzed under a dissecting microscope by subgross method of observation. Submacroscopic foci of invasive cancer, well separated and apparently independent of the primary tumor, were found in 19% of the cases and were confirmed by histologic examination. Foci of submacroscopic cancer were either single (79%) or multiple (21%), and were located in slices including or not the main tumor mass (31% and 69% of cases, respectively). Their size ranged from 1 to 4 mm. Four histologic types were represented: 1) invasive ductal NOS with productive fibrosis, scirrhous type (36% of cases); 2) invasive ductal NOS without productive fibrosis, simplex type (32% of cases); 3) invasive ductal with tubular component (16% of cases); 4) medullary (16% of cases). Concordance between histology of clinical and submacroscopic cancers was assessed in 42% of cases. A significant association of the tubular type (invasive ductal carcinoma with a consistent tubular component) of primary tumor was demonstrated (P less than 0.05), as well as with the presence of ductal and lobular proliferative changes in the collateral glandular tree (intraductal papillomas, P less than 0.01; atypical lobules, P less than 0.02). No relationship was found between submacroscopic foci of infiltrating carcinoma and neoplastic familiarity, patients' age by decades, axillary lymph node metastases, size of clinical tumor or profile of the collateral mammary glandular tree. These data support the hypothesis of a multicentric origin of human breast cancer and suggest a systemic nature of the neoplastic mammary disease. Prognostic and therapeutic implications of this concept are discussed.
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PMID:Independent submacroscopic foci of infiltrating carcinoma in breasts removed for clinical cancer. 620

A simple classification system for central nervous system neoplasms occurring primarily in infancy and childhood and largely composed of undifferentiated neuroepithelial cells is proposed. Classification is based upon appearance of the tumor as determined by light microscopy, immunocytochemical techniques, and ultrastructural features without consideration for site of origin. This classification is based on the concept that neoplastic transformation of primitive neuroepithelial cells in subependymal zones at all levels of the central nervous system or pineal body may develop into tumors largely composed of similar cells. It therefore seems appropriate to call these neoplasms primitive neuroectodermal tumors and to use descriptive terms to indicate the direction of cellular differentiation, when it has occurred. Proposed terminology for the five subtypes of undifferentiated neuroepithelial round cell tumors is as follows: 1) Primitive neuroectodermal tumor, not otherwise specified (PNET, NOS), 2) PNET with glial differentiation, 3) PNET with ependymal differentiation, 4) PNET with neuronal differentiation, and 5) PNET with multi- or bipotential differentiation. If the tumor is located in the cerebellum, medulloblastoma may be added in parentheses; if in the pineal body, pineal parenchymal neoplasm may be added.
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PMID:The cerebellar medulloblastoma and its relationship to primitive neuroectodermal tumors. 629 25

We present the DNA sequence and plant-tumor transcription pattern of some 2400 base pairs from the right border region of pTi T37 DNA from the virulent Agrobacterium tumefaciens strain T37. This region includes the entire transcription unit encompassing the nopaline synthase gene, together with parts of other transcription units. The strategy used to determine the sequence also produced two opposing series of defined, asymmetric deletions across the target DNA region, some of which may serve future purposes in the exploitation of this sequence, which is known to be expressed in a wide variety of host plant tissues.
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PMID:Structure and transcription of the nopaline synthase gene region of T-DNA. 629 24

Chimeric bacterial genes conferring resistance to aminoglycoside antibiotics have been inserted into the Agrobacterium tumefaciens tumor-inducing (Ti) plasmid and introduced into plant cells by in vitro transformation techniques. The chimeric genes contain the nopaline synthase 5' and 3' regulatory regions joined to the genes for neomycin phosphotransferase type I or type II. The chimeric genes were cloned into an intermediate vector, pMON120, and inserted into pTiB6S3 by recombination and then introduced into petunia and tobacco cells by cocultivating A. tumefaciens cells with protoplast-derived cells. Southern hybridization was used to confirm the presence of the chimeric genes in the transformed plant tissues. Expression of the chimeric genes was determined by the ability of the transformed cells to proliferate on medium containing normally inhibitory levels of kanamycin (50 micrograms/ml) or other aminoglycoside antibiotics. Plant cells transformed by wild-type pTiB6S3 or derivatives carrying the bacterial neomycin phosphotransferase genes with their own promoters failed to grow under these conditions. The significance of these results for plant genetic engineering is discussed.
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PMID:Expression of bacterial genes in plant cells. 630 51

Agrobacterium tumefaciens strains can incite plant tumors consisting of transformed cells that synthesize novel metabolites called opines. The pattern of opine synthesis is dictated by plasmid-borne genes in the pathogen; additional plasmid genes confer on the pathogen the ability to catabolize the same pattern of opines synthesized. One group of A. tumefaciens strains, AT181, EU6, and T10/73, contains closely related tumor-inducing (Ti) plasmids that encode the ability to degrade the opine nopaline; but tumors incited by these strains do not synthesize nopaline. We demonstrated by Southern blot hybridization that AT181(pTi) has no DNA homologous to the nopaline synthase gene of pTi T37, a nopaline Ti plasmid that appears to be most closely related to this group based on fingerprint analysis. Tumors incited by these seemingly anomalous strains contain a new opine that we designate succinamopine. Its structure is analogous to that of nopaline, with asparagine replacing arginine. Evidence for the structure of succinamopine, as well as those of two related metabolites, succinamopine lactam and succinopine lactam, will be published elsewhere. Ability to catabolize succinamopine, succinamopine lactam, and succinopine lactam is encoded by pTi AT181, pTi EU6, and pTi T10/73, but not by any of 15 other Ti and root-inducing plasmids tested. Three avirulent strains tested did not catabolize succinamopine, succinamopine lactam, or succinopine lactam. We propose that pTi AT181, pTi EU6, and pTi T10/73 be designated the succinamopine Ti plasmids.
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PMID:Succinamopine: a new crown gall opine. 631 54

The DNA sequence of the nopaline synthase gene (nos) from Agrobacterium tumefaciens Ti plasmid pTiT37 and adjacent regions up to the right border of the T-DNA was determined. The 5' and 3' termini of the polyadenylated nos mRNA, isolated from a T37 tobacco teratoma tumor line, were localized by S1 mapping. The final mRNA is unspliced, encoded by a region of about 1450 bp, and specifies an open reading frame of 413 amino acids. Potential transcriptional signals in the 5' flanking DNA, such as CATAAA ("TATA box") and GGTCACTAT ("CAT box"), bear close resemblance to other eukaryotic promoters. Two putative polyadenylation signals, AATAAA and AATAAT, are found about 135 and 50 bp from the 3' end, respectively. This study may provide information for the development of expression vectors for genes in plant cells; moreover, the structural gene can be used as an easy screenable marker.
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PMID:Nopaline synthase: transcript mapping and DNA sequence. 715 89

The presence of mammary lobules around overt cancer and the amount and the type of intraductal tumor component (solid, comedo, cribrous, comedo-cribrous, papillary) were defined in 493 consecutive cases of infiltrating human breast cancer to analyze the association of these parameters with other morphologic parameters, such as productive fibrosis, lymphoid infiltrate and nuclear grade. Data showed a significant inverse relationship between degree of intraductal component and productive fibrosis (p less than 0.01) and direct relationships between a) presence of lobules and degree of intraductal component (p less than 0.02) and b) intraductal component of comedo type and lymphoid infiltrate (p less than 0.02). In addition, marked though not significant associations were observed between a) absence of lobules and intraductal component of papillary type (p less than 0.10) and b) nuclear grade 1 and intraductal component of the comedo type (p less than 0.10). Data suggest that cancers with a high degree of introductal component could have a lobular origin and papillary cancer could have a ductal origin. The other relationships observed might be useful in the subclassification of NOS (not otherwise specified) breast cancer.
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PMID:Relationship of the degree and type of intraductal component with other morphologic findings in breast cancer. 723 65

Simultaneous incubation of primary rat bone-marrow-derived mononuclear phagocytes (BMMo) and tumor cells with gram-negative agents triggers within 24 h interferon gamma (IFN gamma)- and tumor necrosis factor (TNF alpha)-independent tumoricidal activity. On the other hand, BMMo that had been incubated for 24 h with gram-negative agents prior to re-exposure to the same agent had largely lost their ability to generate tumoricidal activity, although their ability to bind lipopolysaccharide (LPS) was not diminished. Parallel measurements of the kinetics of inducible nitric oxide synthase (iNOS), nitrite secretion, and tumoricidal activity triggered in primary BMMo by LPS revealed that these parameters take a coordinate course, reaching a peak within 24 h and then rapidly decaying. Down-regulation of expression of NOS protein and iNOS activity could be attributed neither to down-regulation of LPS receptors nor to L-arginine depletion.
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PMID:Coordinate up- and down-modulation of inducible nitric oxide synthase, nitric oxide production, and tumoricidal activity in rat bone-marrow-derived mononuclear phagocytes by lipopolysaccharide and gram-negative bacteria. 754 2

Salivary gland tumors pose considerable difficulty in diagnostic and prognostic assessment based on the histopathologic features alone. Cathepsin-D is overexpressed in cancer cells where its concentration in the primary tumor is correlated with increased risk of metastasis. DF3 antigen is a tumor associated glycoprotein that is specific for malignant cells of glandular origin. We examined the distribution patterns of cathepsin-D and DF3 antigens in benign (n = 11) and malignant (n = 44) salivary gland tumors of various histologic types. The frequency of cathepsin-D expression is significantly increased (p < 0.001) in salivary gland carcinomas compared to benign mixed tumors (BMT). High levels of cathepsin-D expression was frequent in carcinomas ex BMT, mucoepidermoid carcinomas, poorly differentiated adenocarcinomas-NOS and adenoid cystic carcinomas (ACC). Acinic cell carcinomas and polymorphous low-grade adenocarcinomas were mostly negative. Intense cytoplasmic staining for DF3 antigen was noted in the tumor cells of mucoepidermoid carcinomas, carcinomas ex BMT and poorly differentiated adenocarcinomas-NOS whereas other types of salivary gland carcinomas exhibited either negative or only focal membrane staining. The noted differences in the reactive patterns of cathepsin-D and DF3 antigen among various histologic types of salivary gland carcinomas may have differential diagnostic and prognostic applications.
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PMID:Cathepsin-D and tumor associated antigen DF3 in salivary gland neoplasia. Differential diagnostic and prognostic applications. 754 Jul 54


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