Lung surfactant gelation induced by epithelial cells exposed to air pollution or oxidative stress

Lung surfactant lowers surface tension and adjusts interfacial rheology to facilitate breathing. A novel instrument, the interfacial stress rheometer (ISR), uses an oscillating magnetic needle to measure the shear viscosity and elasticity of a surfactant monolayer at the air-water interface. The ISR reveals that calf lung surfactant, Infasurf, exhibits remarkable fluidity, even when exposed to air pollution residual oil fly ash (ROFA), hydrogen peroxide (H2O2), or conditioned media from resting A549 alveolar epithelial cells (AEC). However, when Infasurf is exposed to a subphase of the soluble fraction of ROFA- or H2O2-treated AEC conditioned media, there is a prominent increase in surfactant elasticity and viscosity, representing two-dimensional gelation. Surfactant gelation is decreased when ROFA-AEC are pretreated with inhibitors of cellular reactive oxygen species (ROS), or with a mitochondrial anion channel inhibitor, as well as when A549-rho0 cells that lack mitochondrial DNA and functional electron transport are investigated. These results implicate both mitochondrial and nonmitochondrial ROS generation in ROFA-AEC-induced surfactant gelation. A549 cells treated with H2O2 demonstrate a dose-dependent increase in lung surfactant gelation. The ISR is a unique and sensitive instrument to characterize surfactant gelation induced by oxidatively stressed AEC.     

补阳还五汤对红核脊髓束横断后神经元的保护作用

目的:探讨补阳还五汤(BYHWD)对红核脊髓束横断后神经元保护作用的影响。方法:雌性SD大鼠随机分为3组:1.正常组;2.实验组:C3-4右侧红核脊髓束横断后灌服补阳还五汤;3.对照组:C3-4右侧红核脊髓束横断后灌服蒸馏水;用FG逆行示踪定位红核脊髓束神经元在红核的分布。动物存活8周后,Nissl染色计数红核脊髓束神经元并计算其平均截面积。结果:红核神经元的数目和平均截面积实验组分别减少了22%和35%,对照组分别减少了42%和64%。结论:BYHWT不仅提高了轴突横断后红核神经元的存活率,还对其萎缩有抑制作用。     

Additive Antinociception between Intrathecal Sildenafil and Morphine in the Rat Formalin Test

The possible characteristics of spinal interaction between sildenafil (phosphodiesterase 5 inhibitor) and morphine on formalin-induced nociception in rats was examined. Then the role of the opioid receptor in the effect of sildenafil was further investigated. Catheters were inserted into the intrathecal space of male Sprague-Dawley rats. For induction of pain, 50 µL of 5% formalin solution was applied to the hind-paw. Isobolographic analysis was used for the evaluation of drug interaction between sildenafil and morphine. Furthermore, naloxone was intrathecally given to verify the involvement of the opioid receptor in the antinociception of sildenafil. Both sildenafil and morphine produced an antinociceptive effect during phase 1 and phase 2 in the formalin test. The isobolographic analysis revealed an additive interaction after intrathecal delivery of the sildenafil-morphine mixture in both phases. Intrathecal naloxone reversed the antinociception of sildenafil in both phases. These results suggest that sildenafil, morphine, and the mixture of the two drugs are effective against acute pain and facilitated pain state at the spinal level. Thus, the spinal combination of sildenafil with morphine may be useful in the management of the same state. Furthermore, the opioid receptor is contributable to the antinocieptive mechanism of sildenafil at the spinal level.     

Bacteremia due to Moraxella atlantae in a cancer patient

A gram-negative alkaline phosphatase- and pyrrolidone peptidase-positive rod-shaped bacterium (CCUG 45702) was isolated from two aerobic blood cultures from a female cancer patient. No identification could be reached using phenotypic techniques. Amplification of the tRNA intergenic spacers revealed fragments with lengths of 116, 133, and 270 bp, but no such pattern was present in our reference library. Sequencing of the 16S rRNA gene revealed its identity as Moraxella atlantae, a species isolated only rarely and published only once as causing infection. In retrospect, the phenotypic characteristics fit the identification as M. atlantae (formerly known as CDC group M-3). Comparative 16S rRNA sequence analysis indicates that M. atlantae, M. lincolnii, and M. osloensis might constitute three separate genera within the MORAXELLACEAE: After treatment with amoxicillin-clavulanic acid for 2 days, fever subsided and the patient was dismissed.     

休克大鼠小肠微循环灌流量和血清TNF的变化及多巴胺的作用

在39只失血性休克大鼠中，用激光多普勒微循环血流计及ELISA法测定静脉注射多巴胺前后小肠微循环增流量及血清TNF浓度的变化。结果发现随休克发展，小肠微循环血液灌流量进行性减少，TNF浓度升高。多巴胺（40μg／100gB．W．）治疗可增加小肠微循环血液油流量和降低血清TNF浓度。两者间呈显著性相关（r＝0．897，P＜0．01）。作者认为，多巴胺通过增加小肠微循环血液灌流量，改善肠壁屏障功能，减少内毒素入血，从而降低血清TNF浓度，保护了脏器功能和减轻细胞损伤。