RP-HPLC法测定牛蒡子中木脂素的含量

用RP-HPLC法分离并测定了牛蒡子中5种2,3-二苄基丁内酯型木脂素——牛蒡甙(Ⅰ)、牛蒡酚A(Ⅱ)、牛蒡酚F(Ⅲ)、牛蒡甙元(Ⅳ)、牛蒡素B(Ⅴ)。以安定为内标,分析柱C₁₈,甲醇-水-乙腈-四氢呋喃(57:49:11:1)为流动相,梯度流速,1.0～1.5m1/min。检测波长220nm,线性范围0.029～0.242μg,相关系数r=0.9993～0.9999,回收率96.14～104.99%。本法简便、快速、灵敏。     

Manpower, entrepreneurs, and antitrust

The problem of nonradiologists practicing radiology is discussed. The trend toward moving the practice of radiology out of the hospital and into the office setting favors the entrepreneur, radiologist and nonradiologist alike. Many clinicians are setting up offices with radiological facilities. Because of the threat of antitrust litigation, radiological societies may be discouraged from speaking out against this practice.     

Activation and proliferation signals in murine macrophages: synergistic interactions between the hematopoietic growth factors and with phorbol ester for DNA synthesis

There has been recent interest in the synergistic interactions between the growth factors involved in the in vitro control of hematopoiesis and other cell lineages. As a convenient model system, such interactions governing the DNA synthesis in murine bone marrow-derived macrophages (BMMs) were studied. By themselves, murine colony- stimulating factor-1 (CSF-1) and recombinant murine granulocyte- macrophage CSF (GM-CSF) were stimulators of DNA synthesis in quiescent or noncycling BMMs, whereas recombinant murine interleukin-3 (IL-3) and the phorbol ester, 12-O-tetradecanoyl-phorbol-13-acetate (TPA), were weak mitogens. On the other hand, murine granulocyte CSF (G-CSF), concanavalin A (Con A), and lipopolysaccharide (LPS) were inactive on their own. When the quiescent BMMs were exposed to combinations of the CSFs, there were striking synergistic effects for both GM-CSF and IL-3 with suboptimal doses of CSF-1, with a smaller effect for GM-CSF with IL-3 and little or no effect for CSF-1 with G-CSF. CSF-1, GM-CSF, and IL-3 could also synergize with TPA; CSF-1 cooperated with 1-oleoyl-2- acetylglycerol (OAG), both sets of results pointing to an interaction with protein kinase C. LPS completely abolished the CSF-1-mediated stimulation of DNA synthesis. We propose that BMMs are suitable normal cells in which to examine in depth the various mechanistic possibilities for these interactions.