Effects of zymosan-activated plasma and phorbol myristate acetate on isolated, perfused rabbit lungs

The effects of complement activation on pulmonary vascular permeability are disputed. In rabbit lungs perfused with autologous blood, zymosan activated plasma (ZAP) induced a moderate increase in pulmonary vascular resistance (PVR), but did not detectably change the vascular permeability within 2 h. The stronger neutrophil granulocyte (PMN) activator, phorbol myristate acetate (PMA), usually gave larger PVR increases and also increased pulmonary vascular permeability. Lungs from neutropenic animals, similarly perfused and given PMA, showed unchanged PVR reactions but had no apparent increase in vascular permeability. Lungs perfused with cell-free medium and given PMA displayed modest PVR increases, and no measurable permeability change. The lung preparatory procedure itself markedly influenced leukocyte circulation. Exsanguination of lung donors decreased the concentration of circulating PMN significantly, and they virtually disappeared from the perfusate within minutes after start of lung perfusion. PMN-mediated effects must therefore have been caused by cells already sequestered in the lungs. We conclude that ZAP does not induce an increased pulmonary vascular permeability in isolated, perfused rabbit lungs, in contrast to PMA. The permeability effects of PMA appear to be PMN dependent.     

以乙二胺为核心的聚酰胺-胺树形高分子的合成及毛细管电泳分离研究

在-30℃下合成了1．0G～6.0G聚酰胺．胺(PAMAM)树形高分子，并采用核磁共振、元素分析对其进行了表征；采用毛细管电泳对1．0GPAMAM进行了分离。结果表明：在该温度下合成的PAMAM具有较好的结构完整性，而毛细管电泳是一种有效的分离提纯PAMAM树形高分子的方法。     

羟乙基淀粉对内毒素感染大鼠肺部毛细血管通透性的影响

目的 观察羟乙基淀粉(HES 200/0.5)对内毒素感染大鼠肺部毛细血管通透性的影响。方法 雄性Wistar大鼠42只随机分为对照组,内毒素组(LPS,6 mg/kg),LPS HES组(HES,3.75、7.5、15、30ml/kg)及HES对照组(30ml/kg)。分别于LPS注入后4 h检测肺组织毛细血管通透性、肺湿干重比、肺组织中性粒细胞(PMN)浸润,2 h检测肺组织核转录因子kappaB(NF-κB)水平。结果3.75 ml/kg和7.5 ml/kg HES显著降低肺毛细血管通透性、湿干重比和PMN浸润(P<0.05),3.75、7.5和15 ml/kgHES显著降低肺NF-κB活性(P<0.05)。结论较低剂量HES具有抑制感染状念下毛细血管漏的作用,这种作用的产生可能与其降低肺组织PMN浸润、抑制核转录因子NF-κB有关。     

微波辅助提取茯苓中茯苓多糖的研究

目的将微波辅助提取新技术应用于茯苓水溶性多糖的提取，寻求最佳提取工艺。方法采用均匀优化设计试验条件，以苯酚-硫酸法测定样品中多糖含量。对超声辅助提取和传统水提法比较，并对水解前后的微波提取多糖衍生物用毛细管电泳检测。结果最佳提取条件：时间为18min；固液比为1：50；微波占空比42％，此时提取率为2．792％。优于传统。结论微波辅助提取速度更快、提取效率更高；毛细管电泳检测表明微波提取茯苓多糖过程合理，能得到较理想的提取物。     

Does Fluid Flow Across the Intestinal Mucosa Affect Quantitative Oral Drug Absorption? Is It Time for a Reevaluation?

Purpose. Hydrophilic and charged solutes have a lower membrane permeability which is due to a lower partition into the lipid membrane (low solubility in the membrane phase) and/or a slower transcellular diffusion coefficient. They are therefore anticipated to be absorbed through the paracellular route, which is a consequence of diffusion and a convective volume flow through the water-filled intercellular space. Methods. Two approaches have been used to investigate the mechanisms underlying the paracellular drug transport across the intestinal mucosa: (a) including water transport by exposing the apical side of the epithelium with a hypotonic solution, and (b) stimulated paracellular transport by widening of tight junction and increased water absorption as a consequence of the sodium-coupled transport of nutrients. Results. Among the first studies that recognized this fluid flux dependent transmucosal transport of drugs, was one published by Oschenfahrt & Winne in 1973 and the one by Kitazawa et al. in 1975. During the last two decades the importance of this paracellular route for drug delivery have been explored in vitro and in situ. Conclusions. The limits concerning molecular weight, shape, ionization and the effect of physiological stimulants, such as luminal concentrations of nutrients, osmolality and motility, are currently under investigation. However, recently published in vivo human data by ourselves and others indicate that the promising results obtained in vitro and in situ for various hydrophilic compounds might not be valid in quantitative aspects in humans, especially not for drugs with a molecular weight over 200.     

A New Method for Estimating Dermal Absorption from Chemical Exposure. 3. Compared with Steady-State Methods for Prediction and Data Analysis

Purpose. This paper compares unsteady-state and steady-state methods for estimating dermal absorption or analyzing dermal absorption data. The unsteady-state method accounts for the larger absorption rates during short exposure times as well as the hydrophilic barrier which the viable epidermis presents to lipophilic chemicals. Methods. Example calculations for dermal absorption from aqueous solutions are presented for five environmentally relevant chemicals with molecular weights between 50 and 410 and log₁₀K_ow between 0.91 and 6.8: chloromethane, chloroform, chlordane, 2,3,7,8-TCDD, and dibenz(a,h)anthracene. Also, the new method is used to evaluate experimental procedures and data analyses of in vivo and in vitro permeation measurements. Results. In the five example cases, we show that the steady-state approach significantly underestimated the dermal absorption. Also, calculating permeability values from cumulative absorption data measured for exposure periods less than 18 times the stratum corneum lag time will overestimate the actual permeability. Conclusions. In general, steady-state predictions of dermal absorption will underestimate dermal absorption predictions which consider unsteady-state conditions. Permeability values calculated from data sets which include unsteady-state data will be incorrect. Strategies for analyzing in vitro diffusion cell experiments and confirming steady state are described.     

糖皮质激素受体阻断对烫伤大鼠肺、肾血管壁通透性变化的影响

我们以糖皮质激素受体（ＧＲ）的竞争性拮抗剂ＲＵ３８４８６（简称ＲＵ４８６）阻断大鼠体内的ＧＲ，并通过检测肺、肾组织匀浆中荧光标记白蛋白的含量，观察了烫伤后１２ｈ大鼠肺、肾血管壁通透性的变化以及阻断ＧＲ对这种变化的影响。结果显示：烫伤后１２ｈ，大鼠肺、肾组织匀浆中荧光标记白蛋白含量明显高于对照组（肺：Ｐ＜０．０５；肾：Ｐ＜０．００１）；阻断ＧＲ后再烫伤大鼠，其肺、肾组织匀浆中的荧光白蛋白含量又显著高于烫伤组（Ｐ＜０．０５）。提示：①烫伤后１２ｈ，大鼠肺、肾血管壁通透性明显升高。②ＧＲ减少可加重烫伤所致的血管壁通透性升高，并可逆转内源性糖皮质激素（ＧＣ）稳定血管壁通透性的作用。     

Acute heart failure and acute renal failure in Kawasaki disease

Acute renal failure and acute heart failure are rare in Kawasaki disease. We experienced two patients with Kawasaki disease who presented acute renal failure and acute heart failure. These two patients gave us an important insight into the understanding of water balance and fluid therapy in Kawasaki disease. One patient showed acute prerenal failure due to fluid exudation from the intravascular to the extravascular space, and subsequent acute heart failure. The other patient showed acute heart failure caused by fluid infusion for the treatment of dehydration. It is suggested that acute renal failure could be caused by a fluid shift from the intravascular to the extravascular space in Kawasaki disease. It is also demonstrated that the reserve of cardiac function could be decreased in patients with Kawasaki disease due to myocarditis even with normal echocardiography and chest X-rays.     

Reversible and irreversible effects of chemical fixation on the NMR properties of single cells.

The effects of chemical fixation are known to alter MR parameters, such as relaxation times and the apparent diffusion coefficient (ADC) of water. It is often assumed that such changes are reversible after samples have been reimmersed in a buffer solution for a sufficient period of time. In this study we characterize the changes associated with fixation of single Xenopus laevis oocytes and their subsequent reimmersion in buffer. Substantial reductions in both T(1) and T(2) values were measured for all compartments of the cell after fixation, with the cytoplasm showing larger changes than the nucleus. After reimmersion in buffer, there were small but statistically significant differences in MR parameters between fresh and reimmersed cells. Experiments with a gadolinium (Gd) contrast agent showed evidence of irreversible changes in the permeability of cellular membranes to small molecules.     

小鼠眼球中脂肪酸组成分析

用气相色谱法分析了小鼠眼球中脂肪酸的组成及百分含量。分离是在２５ｍ×０．２５ｍｍＰＥＧ－２０Ｍ熔融石英毛细管柱内进行，眼球中１２种主要饱和及不饱和脂肪酸得到了定性和定量。本实验可为有关眼疾病的治疗、预防及生化方面的深入研究提供有意义的信息。