Informatics tools to improve clinical research.

During the conduct of complex clinical trials, there are numerous sources and types of data collection and project coordination problems. Methods and approaches to address the conduct of a trial vary in both the cost and time to perform and the potential benefit. Informatics tools can help trial coordinators and investigators ensure the collection of high quality research data during all phases of a clinical trial.

Characterization of human fibroleukin, a fibrinogen-like protein secreted by T lymphocytes.

We have recently cloned the human homologue of the murine pT49 cDNA (hpT49h), a transcript encoding a protein homologous to the beta- and gamma-chains of fibrinogen. Here, we report the identification of the hpT49h gene product using mAbs generated against a peptide corresponding to the carboxyl-terminal end of the deduced protein and a recombinant protein fragment expressed in Escherichia coli. mAbs 23A6, 7B12, and 3F4 specifically recognized a protein of 70 kDa in reducing SDS-PAGE in the culture supernatant of 293T cells transiently transfected with the full length hpT49h cDNA and freshly isolated PBMC. Under nonreducing conditions, the material migrated with a molecular mass of 250 to 300 kDa, indicating that the 70-kDa protein forms a disulfide bonded complex. Because of its homology with fibrinogen, we have termed this protein fibroleukin. Fibroleukin is spontaneously secreted in vitro by freshly isolated CD4+ and CD8+ T lymphocytes. RT-PCR analysis revealed preferential expression of fibroleukin mRNA in memory T lymphocytes (CD3+/CD45R0+) compared with naive T lymphocytes (CD3+/CD45RA+). Fibroleukin production by PBMC was rapidly lost in culture. Production could be partially maintained in the presence of IFN-gamma, while T lymphocyte activation had no effect. To demonstrate fibroleukin production in vivo, we analyzed colon mucosa by immunohistology. Fibroleukin staining was detected in the extracellular matrix of the T lymphocyte-rich upper portion of the lamina propria mucosa. While the exact function of fibroleukin remains to be defined, these data suggest that fibroleukin may play a role in physiologic lymphocyte functions at mucosal sites.

An adhesion variant of the MG-63 osteosarcoma cell line displays an osteoblast-like phenotype.

MG-63 human osteosarcoma cells were selected for attachment and growth in increasing concentrations of a synthetic peptide containing the cell attachment-promoting Arg-Gly-Asp (RGD) sequence derived from the cell-binding region of fibronectin. Cells capable of attachment and growth in 5 mM concentrations of a peptide having the sequence Gly-Arg-Gly-Asp-Ser-Pro overproduce the cell surface receptor for fibronectin. No increase in fibronectin receptor gene copy number was detected by Southern blot analysis. The peptide-resistant MG-63.3A cells look very different from the MG-63 cells and resemble osteocytes. The resistant cells also grow more slowly than MG-63 cells. The enhanced expression of the fibronectin receptor on the resistant cells indicates that cells can regulate the amount of this receptor on their surface in response to environmental factors and that this may affect the phenotypic properties of the cell. MG-63.3A cells differ from MG-63 cells in their ability to form a calcified matrix in vitro and in their increased synthesis of type I collagen. The MG-63.3A cells synthesize 50-100-fold less prostaglandin E2, a mediator of bone resorption, than MG-63 cells. There is an overall down-regulation of chondroitin sulphate proteoglycans in MG-63.3A cells. These results are consistent with the hypothesis that such proteoglycans interfere with calcium phosphate deposition and with the observation that chondroitin sulphate is increased in a wide variety of neoplasms but is absent or in small amounts in normal tissue. We conclude that MG-63.3A cells represent a more differentiated cell type with osteoblast-like properties.