In vitro and in vivo selectin-blocking activities of sulfated lipids and sulfated sialyl compounds

There is accumulating evidence that sulfated lipids, sulfated oligosaccharides and other sulfated compounds are reactive with selectins in a manner that interferes with selectin interactions with their natural ligands. In the report we describe the ability of sulfated lipids (sulfatides and gangliosides) and multimeric forms of sulfated sialic acid to block binding of P- and E-selectin-Ig to neutrophils. The in vivo ability of these compounds to block lung injury in rats following i.v. infusion of purified cobra venom factor (CVF), which induces injury that is L- and P-selectin dependent, was also determined as well as effects on recruitment of neutrophils, as measured by lung myeloperoxidase. There was a significant correlation between the ability of sulfated lipids and sialyl compounds to interfere in vitro with P-selectin-Ig binding to neutrophils and to protect against P-selectin-dependent acute lung injury induced by CVF. The biological effects of these sulfated compounds were also associated with diminished accumulation of neutrophils. The protective effects of these compounds may be linked to their ability to interfere with P- selectin binding to counter-receptors on neutrophils.      

诺氟沙星的吸附行为及其测定

诺氟沙星在0.05mol·L^-1NH₄Cl (pH 5.8)溶液中,出现一灵敏的示波极谱还原峰。峰电位为-1.44 V (vs SCE)。峰高与诺氟沙星的浓度在1.0×10^-7～4.0×10^-6mol·L^-1范围内成正比,检出限为5.0×10^-8mol·L^-1,并用于样品的测定。用线性扫描与循环伏安法等手段研究体系的吸附性质。实验表明,该电极过程为具有吸附性的不可逆过程。     

Kalman滤波分光光度法同时测定多相脂质体口服液中氟尿嘧啶和尼泊金的含量

本文提出了对测量值平滑后,用Kalman滤波分光光度法同时测定多相脂质体口服液中氟尿嘧啶和尼泊金的含量,改善了滤波效果,较好地解决了复杂基质存在下多组分的同时测定。用人工合成样考察表明,在269～273nm间滤波结果较好。用分别相当制剂标示量80,100,120%的两组分九种可能组合人工合成样品考查结果表明,氟尿嘧啶和尼泊金的回收率分别为99.3～102.6%和97.8～103.0%;当存在系统误差时,回收率分别为99.4～102.7%和97.0～102.9%     

鼠肺门剥脱后肺淋巴引流中断对抗体反应的影响

肺移植后肺感染的发生率比其它器官移植后明显增高，这提示移植肺的免疫反应可能受损。为了研究肺淋巴引流中断对抗体反应的影响，我们用肺门剥脱鼠作为模型，设计了３个实验：（１）用着色淋巴造影术目视检查肺门淋巴管的再生；（２）在支气管内滴注碳粒子后观察粒子从肺到肺引流淋巴结的运输；（３）用羊红细胞使肺免疫后测定抗体反应。结果显示肺门淋巴管被肺门剥脱术所中断，在术后７天开始再生；在术后第１周粒子运输到肺引流淋巴结受阻，此后逐渐恢复正常；在肺门剥脱后７天和１０天免疫的鼠血清抗体反应缺如或低下，其后１月内恢复。由此得出结论，只要抗原不能经淋巴管从肺运送到肺引流淋巴结，肺门剥脱肺内的抗原抗体反应就受到损害。该发现可部分地解释为什么在肺移植后最初几周内经常发生肺感染。     

What did the doctor say--what did the patient hear? Operational knowledge in clinical communication

OBJECTIVES: We aim to introduce Piaget's concept of 'operational knowledge' from the cognitive theory of learning--as a contribution to the broader understanding of clinical interaction. METHOD: Our study involves a theoretical presentation of different kinds and levels of human understanding, illustrated by a case story in which the difference between operational and figurative knowledge was demonstrated. This study used the case story of a male patient aged 80, who was suffering from ulcerative colitis. We appealed to the reader's perceived relevance of these perspectives, in order to understand what was going on between doctor and patient. RESULTS: The case story demonstrates the phenomenon of operational knowledge in the patient, the close links between communicative action and cognitive understanding, and the importance for the doctor of reflecting upon this level of interaction. CONCLUSION: According to the patient-centred clinical method, the doctor should explore the social and emotional context of the patient in order to understand the meaning of the illness. We suggest that a cognitive dimension should also be added, and that the concept of 'operational knowledge' might be useful for such investigations.