Relationship between vessel density and expression of vascular endothelial growth factor and basic fibroblast growth factor in small cell lung cancer in vivo and in vitro.

In 21 human small cell lung cancer (SCLC) cell lines, we determined the expression of mRNA and secreted protein levels of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF). The VEGF expression was highly variable between cell lines, with a > 100-fold variation, under identical in vitro conditions. The bFGF expression in cell lines was generally very low. Nine of the cell lines were further analyzed during growth as solid tumor xenografts in nude mice (in vivo). A more uniform VEGF protein expression was present in vivo. Compared with the variable in vitro expression, VEGF was relatively up-regulated in the tumor lines CPH 54A and CPH 54B and down-regulated in GLC 3. One line, DMS 79, had a high VEGF expression in vivo as well as in vitro. The vessel density was determined by Chalkley point counting on CD31 immunostained cryosections of tumors of each of the nine SCLC lines. We found a strong positive correlation between vessel density and tissue VEGF protein expression (r(s) = 0.75; P = 0.02) and a comparatively strong negative correlation (r(s) = -0.80; P = 0.01) between vessel density and tissue bFGF expression. No significant correlation was present between vessel density and in vitro VEGF expression. We conclude that VEGF and bFGF expression is dependent on microenvironmental conditions, as well as cell line-specific factors, and that a strong positive correlation exists between in vivo VEGF expression and vessel density, whereas high tissue levels of bFGF are not correlated with higher vessel densities in SCLC xenografts.

Application of ultrasonic backscattering for level measurement and process monitoring of expanded-bed adsorption columns.

Expanded-bed adsorption is a newly commercialized technique for the purification of proteins from cellular debris in downstream processing. An expanded bed presents the possibility of protein recovery in a single step, eliminating the often costly clarification processing steps such as ultrafiltration, centrifugation, and precipitation. A major obstacle to the successful commercialization of this technology is the inability to accurately monitor and control the bed height in these systems. Fluctuations in the feedstock viscosity are common during normal operation and tend to make the operation and control of expanded beds for biological applications complex and difficult. We develop a level measurement technique based upon ultrasonics. It is shown that this technique has great promise for bed-height measurement in expanded-bed adsorption systems. Furthermore, the bed-height measurement can be used in feedback control strategies for bed-height regulation. The proposed ultrasonic sensor is also capable of monitoring for plugging and bubbling in the column.

The treatment of the hemolytic-uremic syndrome with inhibitors of platelet function.

In four patients with clinical and laboratory manifestations of the hemolytic-uremic syndrome, the administration of aspirin and dipyridamole was associated with a dramatic and rapid increase in the platelet count. In three of the four patients there was also improvement in neurologic or renal function. No subject experienced bleeding or other untoward effects. We conclude that a trial of aspirin and dipyridamole therapy is warranted early in the course of the hemolytic-uremic syndrome.