L-精氨酸对大鼠急性肺损伤和内皮素水平的影响

［ 目的］ 观察Ｌ 精氨酸对大鼠急性肺损伤和内皮素水平的影响．［ 方法］ 将３０ 只Ｗｉｓｔａｒ 大鼠随机分为正常组、损伤组、Ｌ 精氨酸组,各组在乌拉坦麻醉下用微量注射器从股静脉给药物,观察１２０ｍｉｎ 时的动脉血氧分压、肺组织中的内皮素变化和肺水含量变化．［ 结果］Ｌ 精氨酸可以提高动脉血氧分压,减轻肺水肿,但对肺组织内皮素水平却无影响．［ 结论］Ｌ 精氨酸可以减轻大鼠急性肺损伤时肺水肿,但不影响内皮素的分泌．     

Elective affinities: a Tudor–Aubergine tale of germline partnership

In Drosophila melanogaster and many other metazoans, the specification of germ cells requires cytoplasmic inheritance of maternally synthesized RNA and protein determinants, which are assembled in electron-dense cytoplasmic structures known as germ or polar granules, found at the posterior end of the oocytes. Recent studies have shown that the formation of germ granules is dependent on the interaction of proteins containing tudor domains with the piwi-interacting RNA (piRNA)-binding Piwi proteins, and such interactions are dependent on symmetrically dimethylated arginines (sDMAs) of Piwi proteins. Tudor–Piwi interactions are crucial and are conserved in the germ cells of sexually reproducing animals, including mammals. In the September 1, 2010, issue of Genes & Development, Liu and colleagues (pp. 1876–1881) use a combination of genetics, biochemistry, and crystallography to uncover the molecular and structural details of how Tudor recognizes and binds the sDMAs of the Piwi protein Aubergine.     

精氨酸对治疗性内镜逆行胰胆管造影后急性胰腺炎的预防作用

目的 :探讨精氨酸对治疗性内镜逆行胰胆管造影 (ERCP)后急性胰腺炎的预防作用。方法 :173例胰管均显影的患者随机分成治疗组 (A组 ,n =87)和对照组 (B组 ,n =86 ) ,A组治疗前、后静滴精氨酸 ,B组除不用精氨酸外 ,其他处理方法同A组。结果 :治疗性ERCP后高淀粉酶血症发生率 ,A组和B组分别为 2 7 6 %和 6 5 1% (P <0 0 1) ,急性胰腺炎发生率分别为2 3%和 11 6 % (P <0 0 5 )。结论 :精氨酸对治疗性ERCP后急性胰腺炎有明显的预防作用。     

Immunonutrition in High‐Risk Surgical Patients

Background: Immunomodulating diets (IMDs) have been demonstrated to improve immune function and modulate inflammation. However, the clinical benefit of these diets in patients undergoing elective surgery is controversial. The goal of this meta‐analysis was to determine the impact of IMDs on the clinical outcomes of high‐risk patients undergoing elective surgery. Methods: The review included prospective, controlled, clinical trials that compared the clinical outcome of elective surgical patients who were randomized to receive an IMD or a control enteral diet. Studies were stratified according to the type of IMD and the timing of the initiation of the IMD. Data were abstracted on study design, study size, patient population, and IMD used. The outcomes of interest were the acquisition of new infections, wound complications, length of hospital stay (LOS), and mortality. Meta‐analytic techniques were used to analyze the data. Results: Twenty‐one relevant studies were identified, which included a total of 1918 patients. Immunonutrition significantly reduced the risk of acquired infections, wound complications, and LOS. The mortality rate was 1% in both groups. The treatment effect was similar regardless of the timing of the commencement of the IMD. The benefits of immunonutrition required both arginine and fish oil. Conclusions: An immunomodulating enteral diet containing increased amounts of both arginine and fish oil should be considered in all high‐risk patients undergoing major surgery. Although the optimal timing cannot be determined from this study, it is suggested that immunonutrition be initiated preoperatively when feasible.     

葡萄糖、精氨酸影响新生大鼠胰B细胞群的形态定量研究

目的 :研究葡萄糖、精氨酸对新生大鼠胰 B细胞群的影响。方法 :选用 Wistar新生大鼠 ,自出生后第 2日起腹腔注射葡萄糖加精氨酸 ,共 6天。分别于出生后第 10天、2 0天剖腹取胰腺 ,进行常规 HE及免疫组织化学 (PAP)染色 ,显示胰岛及 B细胞。并结合图像分析仪测量胰岛及 B细胞。并结合图像分析仪测量胰岛及 B细胞的直径。结果 :生后 2 0天 ,实验组大鼠胰 B细胞群较第 10天的明显增大 ,而对照组 B细胞群却较第 10天显著缩小 ;第 2 0天两组胰岛直径均较第 10天的小 ,但以对照组的变化明显。结论 :在葡萄糖、精氨酸的作用下 ,新生大鼠胰 B细胞群及胰岛其它内分泌细胞增生     

未经提取的血浆中精氨酸加压素的放射免疫测定

应用本教研室制备的兔抗AVP血清,我们建立了人及大鼠未经提取的血浆AVP的放射免疫测定法(RIA)。本法灵敏度为1.2pg/管,相当于血浆浓度为4pg/ml。回收率分别为112％(人血浆)和117％(鼠血浆)。加样量与测出量及与标准曲线之间有很好的平行关系。组内和多间变异系数(C.V.％)分别为.24％和23.04％。用本法测得4名正常人血浆AVP含量平均为5.2pg/ml,10只正常大鼠血浆AVP浓度为4.2±0.34pg/ml(X±SE)。’禁水36小时后,大鼠血浆AVP含量为34.3±9.7 pg/ml(X±SE)。本法能测定病理生理状态下AVP含量的变化,为某些疾病的诊断及研究提供一种有效的手段。     

L-精氨酸对乳猪深低温停循环脑代谢与结构的影响

目的　通过深低温停循环 ( DHCA)转流模型 ,研究左旋精氨酸 ( L- arg)在低温缺血时对脑代谢和结构的影响。　方法　采用上海种白猪 ,3～ 4周龄 ,随机均分成 4组 :L- arg组 ,左旋硝基精氨酸甲酯 ( L- NAME)组 ,L- arg L-NAME组和对照组 ,每组 10只。按临床方法行心肺转流术 ,于转流前、降温末、复温末和转流结束等分别测定颈内静脉一氧化氮 ( NO)、脑皮质三磷酸腺苷 ( ATP)和颈内静脉乳酸含量。并行脑组织学和超微结构观察。　结果　降温末 L-NAME组和对照组 NO含量较其它两组明显下降 ( P<0 .0 1)。复温末 ,除 L- NAME组外 ,其余 3组均恢复至转流前水平( P<0 .0 1) ,L- arg组 NO水平在复温末较转流前高 ( P<0 .0 1)。转流开始后大脑皮质 ATP即有明显下降 ,L- arg组下降幅度最小 ,且在复温末已接近转流前水平 ;L- NAME组下降幅度最大 ( P<0 .0 1)。转流开始后颈内静脉乳酸含量即升高 ,L- arg组和 L- arg L- NAME组上升幅度较小 ;降温末和转流结束乳酸含量较其它两组低 ( P<0 .0 1)。大脑皮质组织学和超微结构检查显示 ,大脑皮质细胞结构变化 L- arg组和 L- arg L- NAME组较对照组和L- NAME组轻。　结论　深低温停循环手术时 ,应用 L- arg具有较好的脑保护作用 ,而 L- NAME有脑损害作用。 L- arg可部分     

Cyclic and linear bradykinin analogues: implications for B2 antagonist design

Abstract: Bradykinin (BK, Arg-Pro-Pro-Gly-Phe-Ser-Pro-Phe-Arg) antagonists are potentially useful for treating inflammation, pain and severe trauma. To identify what chemical features might promote effective antagonism, we replaced Arg¹ and Pro⁷ with structurally constrained and proteolytic-resistant residues, such as Bip (biphenylalanine), Dip (diphenylalanine) or 2Ind (indane amino acid). To determine which BK folding might lead to favourable interactions with receptors, the effects of cyclo^(3,8) vs. cyclo^(5,8) analogues were compared. The resulting BK analogues were examined for their agonistic and antagonistic activities in guinea pig ileum, rat uterus and depressor assays. The results suggest that co-planarity of the residue-7 side chain with its backbone NH is important for potent agonism as well as antagonism, and a d -directed side chain is crucial for antagonism. For residue-1 an l -orientation is important, and Dip¹ may mimic a folded Arg¹ side chain to elicit agonistic activities, with Bip¹ mimicking an extended Arg¹ side chain to elicit inhibitory activities. However, ileal and uterine receptors appear to prefer differently folded BK. For ileum, a BK conformation in which residues-3 and -8 are proximal to each other, but apart from residue-5, led to improved pA₂.