Delineation of Chondroid Lipoma: An Immunohistochemical and Molecular Biological Analysis

Aims. Chondroid lipoma (CL) is a benign tumor that mimics a variety of soft tissue tumors and is characterized by translocation t(11;16). Here, we analyze CL and its histological mimics. Methods. CL (n = 4) was compared to a variety of histological mimics (n = 83) for morphological aspects and immunohistochemical features including cyclinD1(CCND1). Using FISH analysis, CCND1 and FUS were investigated as potential translocation partners. Results. All CLs were strongly positive for CCND1. One of 4 myoepitheliomas, CCND1, was positive. In well-differentiated lipomatous tumors and in chondrosarcomas, CCND1 was frequently expressed, but all myxoid liposarcomas were negative. FISH analysis did not give support for direct involvement of CCND1 and FUS as translocation partners. Conclusions. Chondroid lipoma is extremely rare and has several and more prevalent histological mimics. The differential diagnosis of chondroid lipomas can be unraveled using immunohistochemical and molecular support

Very late relapse in diffuse large B-cell lymphoma represents clonally related disease and is marked by germinal center cell features

Patients with diffuse large B-cell lymphoma (DLBCL) rarely show relapse after 4 years of complete remission (CR). In this study, we addressed the following questions: (1) Does late-relapsing DLBCL represent clonally related disease or a second malignancy; and (2) is there a characteristic biologic background? In 10 of 13 DLBCL patients with relapse after 4 to 17 years, a clonal relationship was established based on identical IgH-sequences and/or identical bcl2-IgH translocation. Most (77%) showed features of germinal center (GC) cells, as defined by expression of CD10, bcl-2, and bcl-6 protein and ongoing immunoglobulin heavy chain variable region (VH) hypermutation. A GC phenotype was seen in 8 (20%) of 38 control patients matched for age, stage, and (extra)nodal localization with relapse within 2.5 years (P =.005). In conclusion, we have found evidence that late-relapsing DLBCL represents truly clonally related disease episodes in most cases and that this clinical behavior may be related to the biologic features of GC cell

Use of propidium monoazide for selective profiling of viable microbial cells during Gouda cheese ripening

DNA based microbial community profiling of food samples is confounded by the presence of DNA derived from membrane compromised (dead or injured) cells. Selective amplification of DNA from viable (intact) fraction of the community by propidium monoazide (PMA) treatment could circumvent this problem. Gouda cheese manufacturing is a proper model to evaluate the use of PMA for selective detection of intact cells since large fraction of membrane compromised cells emerges as a background in the cheese matrix during ripening. In this study, the effect of PMA on cheese community profiles was evaluated throughout manufacturing and ripening using quantitative PCR (qPCR). PMA effectively inhibited the amplification of DNA derived from membrane compromised cells and enhanced the analysis of the intact fraction residing in the cheese samples. Furthermore, a two-step protocol, which involves whole genome amplification (WGA) to enrich the DNA not modified with PMA and subsequent sequencing, was developed for the selective metagenome sequencing of viable fraction in the Gouda cheese microbial community. The metagenome profile of PMA treated cheese sample reflected the viable community profile at that time point in the cheese manufacturing

Multifocal Myxoid Liposarcoma—Metastasis or Second Primary Tumor?: A Molecular Biological Analysis

The classification of multifocal myxoid/round cell liposarcoma, which is defined as tumor presentation in at least two separate sites before manifestation in the lungs, as either metastasis or as a second primary tumor, has essential clinical consequences. Genetically, myxoid/round cell liposarcoma is characterized by t(12;16)(q13;p11) or t(12;22)(q13;q12), and various exon fusion transcripts are described with varying incidences, which permits their use as markers for clonality. Moreover, in solid tumors, analysis of loss of heterozygozity is valuable for clonality analysis. Therefore, fifteen multifocal myxoid/round cell liposarcoma patients with two to five metachronous (n = 12) or synchronous (n = 3) localizations were investigated. Using RT-PCR, the detailed molecular characteristics of the FUS-CHOP and EWS-CHOP breakpoints were determined. Loss of heterozygozity analysis at twelve loci was then used to further analyze clonal relationships. In all patients, tumor sites showed identical FUS-CHOP fusion products. In six patients, identical rare fusion transcripts were found, supporting a clonal relationship. Nine patients had the common exon5-FUS/exon2-CHOP fusion transcript, and two of these were identified as clonally related by loss of heterozygozity analysis. In all other patients, loss of heterozygozity analysis was highly suggestive of a clonal relationship, and no evidence for interpretation of a second primary tumor was found. This study supports the metastatic nature of apparent multifocal myxoid/round cell liposarcoma

Multifactorial diversity sustains microbial community stability

Item does not contain fulltextMaintenance of a high degree of biodiversity in homogeneous environments is poorly understood. A complex cheese starter culture with a long history of use was characterized as a model system to study simple microbial communities. Eight distinct genetic lineages were identified, encompassing two species: Lactococcus lactis and Leuconostoc mesenteroides. The genetic lineages were found to be collections of strains with variable plasmid content and phage sensitivities. Kill-the-winner hypothesis explaining the suppression of the fittest strains by density-dependent phage predation was operational at the strain level. This prevents the eradication of entire genetic lineages from the community during propagation regimes (back-slopping), stabilizing the genetic heterogeneity in the starter culture against environmental uncertainty