Infants of < 30 wk gestation often require respiratory support for several weeks and may develop bronchopulmonary dysplasia (BPD), which is associated with long-term pulmonary disability or death in severe cases.To...Infants of < 30 wk gestation often require respiratory support for several weeks and may develop bronchopulmonary dysplasia (BPD), which is associated with long-term pulmonary disability or death in severe cases.To examine the status of surfactant in infants at high risk for BPD, this prospective study analyzed 247 tracheal aspirate samples from 68 infants of 23-30 wk gestation who remained intubated for 7-84 d.Seventy-five percent of the infants had one or more surfactant samples with abnormal function (minimum surface tension 5.1-21.7mN/m by pulsating bubble surfactometer), which were temporally associated with episodes of infection (p = 0.01) and respiratory deterioration (p = 0.005).Comparing normal and abnormal surfactant samples, there were no differences in amount of surfactant phospholipid, normalized to total protein that was recovered from tracheal aspirate, or in relative content of phosphatidylcholine and phosphatidylglycerol.Contents of surfactant proteins (SP) A, B, and C, measured in the surfactant pellet by immunoassay, were reduced by 50%, 80%, and 72%, respectively, in samples with abnormal surface tension (p≤0.001).Onmultivariable analysis of all samples, SP-B content (r = -0.58, p < 0.0001) and SP-C content (r = -0.32, p < 0.001) were correlated with surfactant function.We conclude that most premature infants requiring continued respiratory support after 7 d of age experience transient episodes of dysfunctional surfactant that are associated with a deficiency of SP-B and SP-C.展开更多
目的:制备石杉碱甲前体液晶制剂并考察其注射性能、形态特征及体外释放度。方法:以二油酸甘油酯和大豆卵磷酯为液晶材料、无水乙醇为溶剂、石杉碱甲为主药制备石杉碱甲前体液晶制剂;用流变仪测量出黏度随剪切速率的变化曲线;用偏光显微...目的:制备石杉碱甲前体液晶制剂并考察其注射性能、形态特征及体外释放度。方法:以二油酸甘油酯和大豆卵磷酯为液晶材料、无水乙醇为溶剂、石杉碱甲为主药制备石杉碱甲前体液晶制剂;用流变仪测量出黏度随剪切速率的变化曲线;用偏光显微镜表征其吸水后形态变化;采用高效液相色谱法测定体外释放度。结果:不同配比的石杉碱甲前体液晶制剂均可以注射;当充分吸水后,大豆卵磷酯∶二油酸甘油酯=70∶30和60∶40时石杉碱甲前体液晶制剂在偏光显微镜下呈现出偏光纹理,其余比例则未呈现出偏光性;大豆卵磷酯∶二油酸甘油酯=70∶30的石杉碱甲前体液晶制剂在p H 7.4磷酸盐缓冲液(PBS 7.4溶液)中持续释药达168 h,累积释放率可达90%以上。结论:前体液晶可以作为石杉碱甲中长效释药体系。展开更多
文摘Infants of < 30 wk gestation often require respiratory support for several weeks and may develop bronchopulmonary dysplasia (BPD), which is associated with long-term pulmonary disability or death in severe cases.To examine the status of surfactant in infants at high risk for BPD, this prospective study analyzed 247 tracheal aspirate samples from 68 infants of 23-30 wk gestation who remained intubated for 7-84 d.Seventy-five percent of the infants had one or more surfactant samples with abnormal function (minimum surface tension 5.1-21.7mN/m by pulsating bubble surfactometer), which were temporally associated with episodes of infection (p = 0.01) and respiratory deterioration (p = 0.005).Comparing normal and abnormal surfactant samples, there were no differences in amount of surfactant phospholipid, normalized to total protein that was recovered from tracheal aspirate, or in relative content of phosphatidylcholine and phosphatidylglycerol.Contents of surfactant proteins (SP) A, B, and C, measured in the surfactant pellet by immunoassay, were reduced by 50%, 80%, and 72%, respectively, in samples with abnormal surface tension (p≤0.001).Onmultivariable analysis of all samples, SP-B content (r = -0.58, p < 0.0001) and SP-C content (r = -0.32, p < 0.001) were correlated with surfactant function.We conclude that most premature infants requiring continued respiratory support after 7 d of age experience transient episodes of dysfunctional surfactant that are associated with a deficiency of SP-B and SP-C.
文摘目的:制备石杉碱甲前体液晶制剂并考察其注射性能、形态特征及体外释放度。方法:以二油酸甘油酯和大豆卵磷酯为液晶材料、无水乙醇为溶剂、石杉碱甲为主药制备石杉碱甲前体液晶制剂;用流变仪测量出黏度随剪切速率的变化曲线;用偏光显微镜表征其吸水后形态变化;采用高效液相色谱法测定体外释放度。结果:不同配比的石杉碱甲前体液晶制剂均可以注射;当充分吸水后,大豆卵磷酯∶二油酸甘油酯=70∶30和60∶40时石杉碱甲前体液晶制剂在偏光显微镜下呈现出偏光纹理,其余比例则未呈现出偏光性;大豆卵磷酯∶二油酸甘油酯=70∶30的石杉碱甲前体液晶制剂在p H 7.4磷酸盐缓冲液(PBS 7.4溶液)中持续释药达168 h,累积释放率可达90%以上。结论:前体液晶可以作为石杉碱甲中长效释药体系。
