基于二氧化硅、百草枯、博莱霉素建立3种大鼠肺纤维模型的差异蛋白质组学分析

目的 以二氧化硅、百草枯、博莱霉素诱导的大鼠肺纤维化(PF)模型为研究对象,以期在3种大鼠PF模型中探究存在差异表达的参与PF发生、发展相关的关键蛋白.方法 应用同位素标记相对与绝对定量技术(iTRAQ)结合液相色谱-串联质谱(LC-MS/MS)分析3种大鼠PF模型肺组织蛋白表达谱;采用Proteome Discove...     

Local cerebral blood flow in spontaneously breathing rats subjected to graded isobaric hypoxia

Local cerebral blood flow (l-CBF) was measured with an autoradiographic technique in spontaneously breathing rats exposed to air or gas mixtures of O2 and N2, giving inspired oxygen fractions (FiO2) ranging from 0.21 to 0.07. The arterial O2 tension (PaO2) changed from 10.9 +/- 0.3 (FiO2 0.21) to 3.9 kPa (FiO2 0.07) (82 +/- 2 to 29 mmHg). Hypoxia caused hyperventilation, and the arterial CO2 tension (PaCO2) fell from 5.21 +/- 0.05 kPa (FiO2 0.21) to 3.27 kPa (FiO2 0.07) (39.1 +/- 0.4 to 24.5 mmHg). The hyperventilatory response was markedly augmented when changing FiO2 from 0.13 to 0.11, causing a fall in PaCO2 of 0.75 kPa and a shift in arterial pH from 7.45 +/- 0.01 (FiO2 0.13) to 7.54 +/- 0.01 (FiO2 0.11). The l-CBF response to hypoxia was found to be biphasic for all the observed regions. At FiO2 0.13, l-CBF was measured about 75% above control but at FiO2 0.11, only 30% above control. A further reduction in FiO2 to 0.07 caused a marked increase in l-CBF, at least 240% of control; however, the applied CBF technique did not admit quantitation. These results suggest that the mechanisms controlling the cerebrovascular response to hypoxia and changes in arterial CO2 tensions are different. The results also indicate that hyperventilation might be harmful to the patient suffering from acute hypoxia.     

Hyperbaric vs. isobaric bupivacaine for spinal anaesthesia for elective caesarean section: a Cochrane systematic review

Both isobaric and hyperbaric bupivacaine have been used for spinal anaesthesia for elective caesarean section, but it is not clear if one is better than the other. The primary objective of this systematic review was to determine the effectiveness and safety of hyperbaric bupivacaine compared with isobaric bupivacaine administered during spinal anaesthesia for elective caesarean section. We included 10 studies with 614 subjects in the analysis. There was no evidence of differences either in the risk of conversion to general anaesthesia, with a relative risk (95%CI) of 0.33 (0.09–1.17) (very low quality of evidence), or in the need for supplemental analgesia, the relative risk (95%CI) being 0.61 (0.26–1.41) (very low quality of evidence). There was also no evidence of a difference in the use of ephedrine, the amount of ephedrine used, nausea and vomiting, or headache. Hyperbaric bupivacaine took less time to reach a sensory block height of T4, with a mean difference (95%CI) of ?1.06 min (?1.80 to ?0.31). Due to the rarity of some outcomes, dose variability, use of adjuvant drugs and spinal technique used, future clinical trials should look into using adequate sample size to investigate the primary outcome of the need for supplemental analgesia.     

剖宫产术布比卡因扩散与脑脊液生化特性的关系

目的探讨剖宫产术脑脊液生化特性与等比重布比卡因扩散的关系。方法腰麻的一次剂量为布比卡因与脑脊液之比15 mg:3 mL稀释混合而成药液,剖宫产腰麻剂量为10 mg/3 mL。比较分析100例剖宫产妇女与58例非妊娠妇女、61例男性与58例非妊娠妇女、22例绝经妇女与36例未绝经妇女(在58例非妊娠妇女组内)中的脑脊液生化5项与最大麻醉水平。结果男性患者脑脊液氯、总蛋白等指标与女性有明显差异(P<0.05)。剖宫产组的年龄以及脑脊液渗透压、总蛋白、钠等4项指标显著低于非妊娠妇女组,而最大麻醉水平显著高于非妊娠妇女组(P<0.01),其中脑脊液渗透压差异最明显。绝经妇女组与未绝经妇女组相比较除年龄外,各指标差异均无统计学意义。结论布比卡因腰麻剖宫产术100例的调查可见脑脊液渗透压与脊髓阻滞程度(麻醉水平)有相关关系。     

Serum proteomic changes in adults with obstructive sleep apnoea

To examine whether differentially expressed proteins are present in the serum of patients with obstructive sleep apnoea (OSA), iTRAQ techniques (isobaric tags for relative and absolute quantification) were employed in a prospective study. Individuals were assigned to either a non‐OSA control group (apnoea–hypopnoea index, AHI <5) or an OSA group (AHI ≥5). Blood samples were collected, aliquoted and frozen at ?80 °C. Protein digestion and tagging with iTRAQ4plex^® and mass spectrometry analysis was then performed (MALDI TOF/TOF). Ten male subjects were included in the control group (age = 45 ± 9.7 years) and 30 male patients in the OSA group (age = 45 ± 10.7 years), the latter being then subdivided into three severity groups. A total of 103 proteins were identified with differential levels between patients with OSA and controls. Of these, 11 proteins were underexpressed and 19 were overexpressed in patients with OSA. C4BPA and thrombospondin were underexpressed in all three OSA severity groups. Among the overexpressed proteins, 13 were overexpressed in the mild OSA group, seven in the moderate group and five in the severe group. Analysis of interactions between the identified proteins revealed that protein alterations in OSA are primarily associated with derangements in lipid and vascular metabolic pathways. This study provides initial evidence that differential protein expression occurs in adults with OSA, and that such proteins change according to disease severity, and appear to primarily involve lipid and vascular metabolic pathways.     

Comparative physiological and proteomic analyses reveal the actions of melatonin in the reduction of oxidative stress in Bermuda grass (Cynodon dactylon (L). Pers.)

The fact of melatonin as an important antioxidant in animals led plant researchers to speculate that melatonin also acts in the similar manner in plants. Although melatonin has significant effects on alleviating stress‐triggered reactive oxygen species (ROS), the involvement of melatonin in direct oxidative stress and the underlying physiological and molecular mechanisms remain unclear in plants. In this study, we found that exogenous melatonin significantly alleviated hydrogen peroxide (H₂O₂)‐modulated plant growth, cell damage, and ROS accumulation in Bermuda grass. Additionally, 76 proteins significantly influenced by melatonin during mock or H₂O₂ treatment were identified by gel‐free proteomics using iTRAQ (isobaric tags for relative and absolute quantitation). Metabolic pathway analysis showed that several pathways were markedly enhanced by melatonin and H₂O₂ treatments, including polyamine metabolism, ribosome pathway, major carbohydrate metabolism, photosynthesis, redox, and amino acid metabolism. Taken together, this study provides more comprehensive insights into the physiological and molecular mechanisms of melatonin in Bermuda grass responses to direct oxidative stress. This may relate to the activation of antioxidants, modulation of metabolic pathways, and extensive proteome reprograming.     

iTRAQ技术鉴定小鼠睾丸发育差异表达蛋白的研究

目的 用同量异位素标记的相对和绝对定量(isobaric tags for relative and absolute quantitation,iTRAQ)技术结合液相色谱质谱技术构建3周龄小鼠与成年小鼠睾丸蛋白差异表达谱系。 方法 分别抽提3周龄小鼠与成年小鼠睾丸总蛋白质,iTRAQ标记,液相色谱（LC）分离蛋白质,LTQ Orbitrap^{TM质谱仪进行蛋白质鉴定。 结果 鉴定出20个差异表达蛋白质,其中18个为3周龄小鼠睾丸高表达蛋白质,2个为成年睾丸高表达蛋白质。差异表达蛋白质主要参与细胞的有丝分裂、减数分裂、细胞增殖、分化、凋亡及精子发生等重要细胞事件。 结论 用目前最新的定量蛋白质组技术,构建的3周龄小鼠睾丸与成年睾丸差异表达蛋白谱系对研究睾丸功能、精子发生有一定理论价值,为定量蛋白组学技术在雄性生殖领域的应用奠定了基础。}