VOLUME 13, NUMBER 03 • OCTOBER 19, 2001

In the Lab

Newsbriefs

In early May each year Professor David Gadsby and collaborators, along with other scientists from around the world, arrive at the Marine Biological Laboratory in Woods Hole, Mass., at the same time as the migrating squid Loligo paelei, whose giant axons contain millions of sodium/ potassium pumps, crucial proteins that sustain a cell’s electrical gradient. It was already known that these pumps extrude three sodium ions from the cell, then take in two potassium ions, but the researchers recently found that the sodium ions are released in a strict sequence, one at a time. This past spring they successfully road-tested new custom software that lets them monitor all three steps simultaneously, at high resolution. The new software will allow a closer look at the shape changes that the pumps undergo during this vital cellular process.

In the results of the first large prospective study of Waldenstrom's macroglobulinemia, lead author Madhav Dhodapkar, assistant professor and head of the Laboratory of Tumor Immunology and Immunotherapy, helped establish the first staging system for the disease. Waldenstrom's macroglobulinemia is a rare, chronic cancer that is classified as a plasma cell neoplasm. It affects plasma cells, which develop from B lymphocytes, or B cells. In the disease, abnormal plasma cells multiply out of control. They invade the bone marrow, lymph nodes and spleen, and produce excessive amounts of the antibody IgM. Excess IgM in the blood causes hyperviscosity of the blood.

The study also measured disease response to the purine analog fludaribine phosphate (FAMP). Purine analogs such as FAMP and 2-chlorodeoxyadenosine (2-CDA) have shown remarkable activity in low-grade lymphoproliferative disorders. Thirty-six percent of the 231 patients in the study responded to FAMP therapy, with 2 percent entering complete remission. A significant new finding of the study, reported in the July 1 edition of Blood, was that b2M measurement should be incorporated into the initial evaluation of patients with Waldenstrom's macroglobulinemia. Serum b2M is also a dominant prognostic factor in both multiple myeloma and chronic lymphocytic leukemia. The multicenter study by the Southwest Oncology Group began in 1992.