The interleukin-6 (IL-6) signal is transduced through membrane-anchored gp130, which is associated with IL-6 receptor (IL-6R) in the presence of IL-6. Soluble forms of gp130 (sgp130) with molecular weights of 90 and 110 Kd were found in human serum. In the presence of recombinant IL- 6 (rIL-6), serum sgp130 were capable of associating with serum sIL-6R. By the sandwich enzyme-linked immunosorbent assay, healthy human sera was shown to contain 390 +/- 72 ng/mL of sgp130. A mouse pro-B-cell line-derived transfectant, BAF-130, expressing human gp130 was used to examine the function of serum sgp130. When supplemented with rIL-6, human serum induced DNA synthesis in BAF-130 cells, whereas the serum deprived of sIL-6R did not. In contrast, the DNA synthesis induced in BAF-130 cells by rIL-6-supplemented serum was increased when the serum was deprived of sgp130. These results indicated that serum sgp130 could negatively regulate the IL-6 signal. Recently, gp130 has been shown to be involved in the signaling processes of oncostatin M, leukemia inhibitory factor, and ciliary neurotropic factor, in addition to those of IL-6. Recombinant sgp130 showed inhibitory effect on the biologic function of such cytokines. This work implies physiologic roles of naturally produced serum sgp130 in modulating signals through gp130.

From a spot in the north Pacific basin with the longitude 170°05'W and latitude 38°26'N we have obtained a boring core of sediments of the Quaternary and Tertiary periods incessantly piled up presumably at the ocean bottom. In our laboratory a sensitive micro-astatic magnetometer as shown in Fig. 1 was set up to detect the weak magnetic vector preserved in the sediments. Permanent magnets we used are so small (0.5 and 5.0 mm in diameter and length respectively) that leaking flux out of the free poles can hardly disturb the remanence of the specimens placed close to the magnetometer during measurement. No effect of remagnetization was observed even when the core surface was brought within 3 mm from the poles. Underneath the magnetometer the core column is rotated about its longitudinal axis while it is kept standing upright. The horizontal component of the fossil magnetism stored in the upper part of the column is determinable then from the deflection of the magnetometer. Next a slice 1 mm thick is cut off from the head of the column by using non-magnetic knife of beryllium copper. The slice is measured and removed. The remaining column is then shifted upwards exactly 1 mm onto the magnetometer and is rotated again about the same longitudinal axis and deflection measured. This simple procedure is repeated more than 1000 times till the height of the column is reduced approximately 2 rn from top. The uppermost slice has the strongest magnetic torque which brings about deflection to be measured on the magnetometer. The torque decreases from top downwards, the rate being 1/r3, where r is the distance from top. From the rate of sedimentation1> '2> we may estimate that each slice of the core represents about 500 years of sedimentation in this part of the basin. The change of magnetic field as the depth increases