Larsen B, Cheng H F, Galask R P
Am J Obstet Gynecol. 1979 Sep 1;135(1):14-21.
A radiometric bioassay based on the continuous monitoring of 14CO2 released from labeled glucose in the presence of amniotic fluid or amniotic fluid with added phosphate has been employed to detect the presence of a phosphate-sensitive bacterial inhibitor in amniotic fluid near term. The time required for detection of the inhibitory activity is approximately 12 hours, in contrast to approximately 36 hours required for a previously reported technique. Application of this radiometric bioassay to demonstrate bacterial growth inhibition by amniotic fluid and physicochemical properties of the inhibitory activity yielded results comparable to those obtained with the older method of plate counts of viable bacteria. By the new technique it was possible to demonstrate that the inhibitory activity was phosephate sensitive, heat stable, inactivated by metal chelation, removed by bentonite, and present in a low-molecular-weight fraction of amniotic fluid.
一种基于在羊水或添加了磷酸盐的羊水中对标记葡萄糖释放的(^{14}CO_2)进行连续监测的放射性生物测定法，已被用于检测足月时羊水中磷酸盐敏感细菌抑制剂的存在。检测抑制活性所需的时间约为12小时，而先前报道的技术所需时间约为36小时。应用这种放射性生物测定法来证明羊水对细菌生长的抑制作用以及抑制活性的物理化学性质，其结果与用较老的活细菌平板计数法得到的结果相当。通过新技术可以证明，抑制活性对磷酸盐敏感、热稳定、可被金属螯合灭活、可被膨润土去除，并且存在于羊水的低分子量组分中。
