Mack J. Fulwyler

Flow cytometric detection and quantitation of immune complexes using human C1q-coated microspheres

A solid phase human C1q-binding fluorescent immunoassay for the measurement of immune complexes in human serum was developed. The solid phase used was 5 micron diameter polystyrene microspheres. Serum immune complexes bound to the C1q-coated microspheres were measured by flow cytometry using fluoresceinated anti-human IgG, and heat-aggregated human IgG as a standard. Patient samples were assayed and results compared to a standard fluoroimmunometric C1q-binding immune complex assay. Greater differences in circulating immune complexes were observed between the healthy control group mean and the mean of the patient values in the microsphere-flow cytometric method than were seen in the standard assay. In the microsphere-flow cytometric assay, the mean patient value was 7.5 times greater than the control mean, whereas in the standard assay the mean patient value was 2.8 times the control mean. Preliminary results suggest greater sensitivity of the microsphere-flow cytometric method over the other method.

Biphasic calcium response of platelet-derived growth factor stimulated glioblastoma cells is a function of cell confluence

Previous reports have linked the spiking or two‐phased character of calcium transients evoked by platelet‐derived growth factor (PDGF) to the position of cells in the cell cycle without regard to cell–cell contact and communication. Because cell confluence can regulate growth factor receptor expression and dephosphorylation, we investigated the effect of cell culture confluence and cell cycle on calcium responses of PDGF‐BB–stimulated A172 glioblastoma cells.

Abstracts presented at ISAC European International Conference for Flow Cytometry and Image Analysis, Epona, Hungary, May 13–16, 1999.

To facilitate research cooperation among the nations of Central and Eastern Europe, ISAC supported the Epona Cytometry Conference in eastern Hungary near Debrecen and the Hortobagy National Park. This was the first ISAC sponsored conference held in Hungary. The 150 attendees included scientists from Hungary, Austria, the Czech Republic, Croatia, Slovenia, Romania, Poland, Ukraine, and Russia. There was also representation from Western Europe, North America, and Japan. Presentations and posters were of typically high ISAC quality. In addition, the Epona meeting attracted an impressive selection of commercial exhibits that provided contacts and improved the awareness of advanced analytical cytology for the attendees. The Epona conference was organized with Hungarian passion and skill by Professor Sandor Damjanovich, Dr. Janos Szollosi, and the members of the Biophysics and Cell Biology Department of the Medical School of Debrecen. The Department has been active in cytometry for over 20 years, and in hosting the conference, it also celebrated the 20th anniversary of its installment of the first cell sorter in Eastern Europe. The successful meeting demonstrates that Hungarians are strong contenders for the organization of future ISAC meetings. During my 1999 Fulbright Scholarship in Professor Damjanovichs Department, I traveled extensively and can verify that there are other unique sites in Hungary—Sopron, Pecs, Lake Balaton, and Budapest—for ISAC meetings. The site of the conference was on the Hungarian Puszta or plain near the Hortobagy National Park, which offered tours to observe “Hungarian Cowboys,” long-horned cattle, twisted-horn sheep, hairy pigs, and water buffalo, which were brought into the Carpathian Basin by the Magyars. Located in beautiful grasslands on the edge of the Park, the Epona Village was an excellent site for the meeting and is distinctly Hungarian. The timing of the conference was dramatic. Hungary was admitted to NATO in April and the Kosovo conflict with Yugoslavia began a few weeks later. During the conference, NATO air raids into Kosovo were being conducted from bases in southern Hungary. There was much concerned discussion among the attendees of the Kosovo situation. All regretted the loss of life, and all shared the hope that creating cooperative projects in science, agriculture, business, and education will lower international tension. In supporting the Epona conference, ISAC contributed importantly to cooperative science.