摘要:

Marginal zone B-cell lymphoma of extranodal mucosa-associated lymphoid tissue (MALT) type is recognized as a distinct clinicopathologic entity in the revised European-American lymphoma (REAL) and recently published World Health Organization (WHO) classifications. These neoplasms are thought to arise from the extranodal equivalent of the lymph node marginal zone. Two recurrent chromosomal translocations, to date, have been implicated in the pathogenesis of these neoplasms. The t(11;18)(q21;q21), which is far more common, disrupts theapi2 gene on chromosome 11q21 and themalt1 (mlt) gene on chromosome 18q21, resulting in the synthesis of a novel fusion gene and protein, API2-MALT1. The t(1;14)(p22;q32), which is uncommon, juxtaposes thebcl-10 gene on chromosome 1p22 adjacent to the immunoglobulin heavy chain (IgH) gene on chromosome 14, wherein BCL10 is overexpressed via the influence of the IgH enhancer. BCL-10 may then form a complex with MALT1 in the cell. Both translocations result in increased inhibition of apoptosis, conferring a survival advantage. Recent work suggests that API2-MALT1 and BCL-10-MALT1 may activate NF-kB and a common downstream signaling pathway.

ISSN:1072-4109    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

Chlamydia trachomatisinfection is the most common bacterial sexually transmitted disease. The authors examined the relation between chronic endometritis, which they term plasma cell endometritis (PCE), and chlamydial infection using plasmid-based polymerase chain reaction (PCR) and immunohistochemical staining (IHC) of paraffin-embedded endometrial sections.C. trachomatisinfection was detected in 5 (24%) of 21 cases of PCE and in 1 (4%) of histologically normal endometrium. The diagnosis of chronic endometritis (with plasma cells confirmed by methyl green pyronin staining) was correctly made in 74% of the cases originally diagnosed as PCE and in 23% of control cases originally diagnosed as normal. The authors conclude that the histopathologic finding of plasma cells in endometrial samples should encourage further examination for chlamydial infection.

ISSN:1072-4109    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

The sugar &agr;-L-fucose is overexpressed in many human malignancies, especially on specific glycoproteins, glycolipids, certain mucins, and putative cell adhesion ligands found on cancer cell surfaces. Many of these molecules are known or suspected mediators of cell-cell adhesion, cell signaling, motility, or invasion. As knowledge of fucose metabolism evolves and specific mechanisms of its distribution and incorporation are more exactly documented, modulation of fucose expression in cancer is becoming increasingly more feasible. The authors propose that cancer cell surface &agr;-L-fucose is a logical target for selective therapeutic ablation. Reduction of fucose content on the surfaces of malignant cells should effectively cripple the cells' physiologic functions by altering or dysregulating cell-cell or cell-matrix interactions, critical for maintaining the malignant phenotype. Significant therapeutic benefits might include modulation of adhesion abnormalities in the cancer cells, reduction of cancer cell motility or invasiveness, reexposure to immune surveillance, or a combination of these events.

ISSN:1072-4109    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

This article reviews practical and theoretical aspects of margin assessment for surgically excised ductal carcinoma in situ of the breast. Different methods of assessing surgical margins are discussed, including selected tangential sections, the margin shaving, and cavity peel methods. Criteria for margin adequacy and the relevance of margin status in the selection of cases for breast conservation are discussed in the context of other important risk factors for local failure.

ISSN:1072-4109    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

The RET proto-oncogene encodes a cell membrane tyrosine-kinase receptor protein whose ligands belong to the glial cell line–derived neurotrophic factor. RET functions as a multicompetent receptor complex that includes &agr;GFRs and RET. Somatic rearrangements of RET designated as RET/PTC (from papillary thyroid carcinoma) were identified in papillary thyroid carcinoma before RET was recognized as the susceptibility gene for MEN2. There are now at least at least 15 types of RET/PTC rearrangements involving RET and 10 different genes. RET/PTC1 and RET/PTC3 are by far the most common rearrangements. All of the rearrangements are due to DNA damage and result in the fusion of the RET tyrosine-kinase (RET-TK) domain to the 5`-terminal region of heterologous genes. RET/PTC rearrangements are very common in radiation-induced tumors but have been detected in variable proportions of sporadic (i.e., non–radiation associated) papillary carcinomas. It is estimated that up to approximately half the papillary thyroid carcinomas in the United States and Canada harbor RET/PTC rearrangements, most commonly RET/PTC-1, followed by RET/PTC-3 and occasionally RET/PTC-2. The cause of these rearrangements in sporadic papillary carcinomas is not known, but the close association between their presence and the papillary carcinoma phenotype indicates that they play a causative role in tumor development. The proposed mechanisms of RET/PTC-induced tumorigenesis and the clinical and pathologic implications of RET/PTC activation are discussed.

ISSN:1072-4109    

出版商:OVID    

年代:2001

数据来源: OVID

ISSN:1072-4109    

出版商:OVID    

年代:2001

数据来源: OVID

ISSN:1072-4109    

出版商:OVID    

年代:2001

数据来源: OVID

ISSN:1072-4109    

出版商:OVID    

年代:2001

数据来源: OVID

ISSN:1072-4109    

出版商:OVID    

年代:2001

数据来源: OVID

ISSN:1072-4109    

出版商:OVID    

年代:2001

数据来源: OVID