Anti-apoptotic effect of insulin on normal hepatocytes in vitro and in vivo

Liver growth factors are known to be anti-apoptotic for hepatocytes. The potential of insulin, a liver co-mitogen, has not been thoroughly evaluated. We studied the anti-apoptotic role of insulin on primary cultures of rat hepatocytes exposed to transforming growth factor-beta (TGF-beta) as the apoptotic agent and in the left portal vein ligation model (LVPL) of liver atrophy. Results show that insulin decreases apoptosis of TGF-beta-treated hepatocyte cultures by 43% (P < 0.002) and the alanine amino transferase (ALT) release by 49% (P < 0.001). Left lobes of LPVL animals displayed a significant increase in the levels of TGF-beta mRNA. In LPVL rats receiving continuous infusion of insulin in the left lobes, the weight of the atrophic lobes was higher over a 7-day period in comparison to control animals. This was associated with lower levels of serum ALT and with a five-fold decrease in the apoptotic index in the left lobes (P < 0.0001). Induction of Akt phosphorylation and increased expression of Bcl-xl were observed in the left lobes of insulin-treated animals. In conclusion, these results show that insulin is anti-apoptotic for normal hepatocytes both in vitro and in vivo and that the action of insulin is associated with increased Bcl-xl expression and Akt activation.     

Anatomy of the crocodilian spinal vein

The crocodilian spinal vein is remarkably robust yet historically overlooked. Using corrosion casting, we describe the anatomy of this vessel and its connections with the caval and hepatic venous systems in representatives from four crocodilian genera. The spinal vein arises from an enlarged occipital sinus over the medulla and extends the entire length of the vertebral column. Unlike in squamate reptiles, the spinal vein is single (nonplexiform), voluminous, and situated dorsal to the spinal cord, and plexi lateral to the cord span between emerging intercostal veins. The connections with the other venous systems are otherwise similar to those in other tetrapods. The overall anatomy of this vessel and its abundant connections with the other venous systems indicate it likely plays a primary role in returning blood to the heart from all parts of the body. Preliminary studies of function suggest that this vessel could also play an adaptive role during basking and diving.     

Variations among clinical isolates of Staphylococcus aureus to induce expression of E-selectin and ICAM-1 in human endothelial cells

Eighteen clinical isolates of Staphylococcus aureus, nine methicillin-sensitive and nine methicillin-resistant, were investigated for their ability to induce expression of E-selectin and ICAM-1 in human endothelial cells. Upregulation of adhesion molecules varied between isolates; 17 isolates induced expression of E-selectin and 13 of ICAM-1. Some isolates induced a significant expression of E-selectin without stimulation of ICAM-1, whereas the opposite was not found. Bacterial viability was required for induction of the adhesion molecules. The kinetics of ICAM-1 expression in S. aureus-infected cells differed from those stimulated with interleukin-1beta (IL-1beta). On the other hand, expression of E-selectin was very similar in S. aureus-infected and IL-1beta-stimulated cells. There was no correlation between ability of S. aureus to induce expression of cell adhesion molecules, methicillin susceptibility, pulse field gel electrophoresis patterns, biochemical characteristics, phage typing and toxin production.     

High-level expression of naked DNA delivered to rat liver via tail vein injection

Background

High levels of foreign gene expression in mouse hepatocytes can be achieved by rapid tail vein injection of a large volume of a naked DNA solution, the ‘hydrodynamics‐based procedure’. Rats are more tolerant of the frequent phlebotomies required for monitoring blood parameters than mice, and thus are better for some biomedical research.

Methods

We tested this technique for the delivery of a therapeutic protein in normal rats, using a rat erythropoietin (Epo) expression plasmid vector, pCAGGS‐Epo.

Results

We obtained maximal Epo expression when the DNA solution was injected in a volume of 25 ml (approximately 100 ml/kg body weight) within 15 s. We observed a dose‐response relationship between serum Epo levels and the amount of injected DNA up to 800 µg. Using quantitative real‐time PCR, the vector‐derived Epo mRNA expression was mainly detected in the liver. When a lacZ expression plasmid was injected similarly, β‐galactosidase was exclusively detected in the liver, mainly in hepatocytes. Toxicity attributable to the technique was mild and transient, as assessed by histochemical analysis. Epo gene expression and erythropoiesis occurred with Epo gene transfer in a dose‐dependent manner, and persisted for at least 12 weeks, the last time point examined. Repeated administration of the plasmid DNA also effectively led to erythropoiesis.

Conclusions

These results demonstrate that gene transfer into the liver via rapid tail vein injection can easily be achieved in the rat, which is more than 10 times larger than the mouse, and has significant value for gene function analysis in rats. Copyright © 2002 John Wiley & Sons, Ltd.

     

Minor vein structure and sugar transport in Arabidopsis thaliana

Leaf and minor vein structure were studied in Arabidopsis thaliana (L.) Heynh. to gain insight into the mechanism(s) of phloem loading. Vein density (length of veins per unit leaf area) is extremely low. Almost all veins are intimately associated with the mesophyll and are probably involved in loading. In transverse sections of veins there are, on average, two companion cells for each sieve element. Phloem parenchyma cells appear to be specialized for delivery of photoassimilate from the bundle sheath to sieve element-companion cell complexes: they make numerous contacts with the bundle sheath and with companion cells and they have transfer cell wall ingrowths where they are in contact with sieve elements. Plasmodesmatal frequencies are high at interfaces involving phloem parenchyma cells. The plasmodesmata between phloem parenchyma cells and companion cells are structurally distinct in that there are several branches on the phloem parenchyma cell side of the wall and only one branch on the companion cell side. Most of the translocated sugar in A. thaliana is sucrose, but raffinose is also transported. Based on structural evidence, the most likely route of sucrose transport is from bundle sheath to phloem parenchyma cells through plasmodesmata, followed by efflux into the apoplasm across wall ingrowths and carrier-mediated uptake into the sieve element-companion cell complex. Received: 5 October 1999 / Accepted: 20 November 1999     

甜菜坏死黄脉病毒内蒙分离物RNA3序列分析及编码25kD蛋白基因在大肠杆菌中的表达

以甜菜坏死黄脉病毒（ＢＮＹＶＶ）内蒙分离物的总ＲＮＡ为模板,通过反转录－ＰＣＲ扩增获得ＢＮＹＶＶＲＮＡ３全长ｃＤＮＡ。将其克隆到ｐＧＥＭ－７Ｚｆ（＋）上,得到重组质粒ｐＧＢＹ５６。序列分析结果表明,内蒙分离物ＲＮＡ３基因组全长为１７７５ｎｔ,其中包含３个开放阅读框架,分别编码２５ｋＤ蛋白、４．６ｋＤ蛋白和一种由５９个氨基酸组成的Ｎ蛋白。与法国Ｆ２分离物、德国Ｇ１分离物和日本Ｓ分离物相比,其核苷酸序列的同源性分别为９６．４％、９６．８％和９７．３％。将２５ｋＤ蛋白编码基因克隆到ｐＪＷ２上,构建了该基因的原核表达载体。ＳＤＳ－ＰＡＧＥ和Ｗｅｓｔｅｒｎｂｌｏｔｉｎｇ分析结果表明,２５ｋＤ蛋白基因在Ｅ．ｃｏｌｉＢＬ２１（ＤＥ３）中经温度（４２℃）诱导后,可特异地表达２５ｋＤ蛋白     

Weekly osimertinib dosing prevents EGFR mutant tumor cells destined to home mouse lungs

The recently conducted ADAURA trial concludes daily dosing of adjuvant osimertinib, a third-generation EGFR tyrosine kinase inhibitor (TKI), improves disease-free survival with stage IB/II/IIIA EGFR -mutated non-small cell lung cancer patients in comparison to placebo. We have developed a preclinical orthotopic mouse model, using luciferase tagged lung adenocarcinoma cells harboring EGFR TKI sensitive exon 19 deletion to model and extend trial implications comparing a weekly vs daily dosing outcome of osimertinib to a first-generation TKI- erlotinib. We find that 100% of mice in both the groups receiving osimertinib daily or weekly before injection of cells show a complete absence of homing of cells in mice''s lungs from day three until day 18 post-injection of cells. On the other hand, 25% and 75% of mice receiving erlotinib daily and weekly before injecting cells show homing of cells to the lungs. The tumors observed in the lungs, when dissected at day 30, confirmed the colonization of the injected cells homing to the organ. Thus, our study establishes the efficacy of pretreatment with osimertinib in reducing tumor cells'' homing to mouse lungs in an in vivo mouse model.     

长链非编码RNA(lncRNA)在氧化型低密度脂蛋白诱导血管内皮细胞损伤中表达谱的变化

目的:探讨长链非编码RNA(long noncoding RNA,lnc RNA)在氧化型低密度脂蛋白(oxidized low-density lipoprotein,ox-LDL)诱导的损伤人脐静脉内皮细胞(human umbilical vein endothelial cells,HUVEC)与正常HUVEC中表达谱的差异。方法:采用lnc RNA芯片检测ox-LDL诱导的损伤HUVEC与正常HUVEC中lncRNA及mRNA的表达差异,筛选出HUVEC损伤相关的lncRNA。结果:相对于正常HUVEC,在ox-LDL诱导的损伤HUVEC中表达上调和下调超过2倍的lncRNAs和m RNAs分别有139种和113种,上调和下调超过4倍的lncRNAs和mRNAs分别有35种和28种。结论:与正常HUVEC比较,ox-LDL诱导的损伤HUVEC中lncRNA的表达谱显著变化,lncRNA可能在血管内皮细胞损伤过程中发挥一定作用。     

选择性冠状静脉动脉化搭桥术中不同移植物的应用疗效比较

目的:对比选择性冠状静脉动脉化(SCVBG)搭桥治疗弥漫性右冠状动脉狭窄病变中选择乳内动脉和大隐静脉作为桥血管的治疗效果。方法:选择2008年10月到2014年10月在我院行SCVBG搭桥的84例患者资料,其中选择大隐静脉作为桥血管进行冠状静脉动脉化搭桥患者46例(大隐静脉桥组),选择乳内动脉作为桥血管进行冠状静脉动脉化搭桥患者38例(乳内动脉桥组)。随访记录两组患者的生存情况、近期复查超声心动图、冠状动脉CTA及心绞痛复发率。结果:乳内动脉桥组患者总生存率(100%)明显高于大隐静脉桥组(82.6%)(P0.05)。乳内动脉桥组患者桥血管和心中静脉通畅率(100%)明显大于大隐静脉桥组(54.35%)(P0.05)。两组患者左心室射血分数(LVEF)较治疗前明显增加,左心室舒张期末内径(LVEDD)较治疗前明显减小(P0.05)。治疗后,乳内动脉桥组患者心绞痛复发率明显小于大隐静脉桥组(P0.05)。结论:SCVBG搭桥治疗弥漫性右冠状动脉狭窄病变中,选择乳内动脉桥效果优于大隐静脉桥,能明显提高桥血管和心中静脉通畅率,降低心绞痛复发率。     

去自主神经效应对环肺静脉消融房颤疗效的影响

目的：探讨去自主神经效应对环肺静脉消融(CPVA)治疗心房颤动(房颤)的远期成功率的影响。方法：选择104 例药物治疗无 效的、有临床症状的阵发性房颤患者作为研究对象,所有患者均接受CPVA 术。分别于术前、术后进行动态心电图检查,术后每3 个月复查一次动态心电。随访房颤消融成功率(术后3个月无房颤被定义为无复发);并记录动态心电心率变异性(HRV)以反映自 主神经功能。结果：本组研究共104 例患者完成了CPVA术,平均手术次数为(1.35术次数为。变次,成功率为77.9%,共随访(24.27 次数为。变异性个月。根据术后是否发生房颤,将患者分为成功组(81例)和复发组(23 例),所有患者CPVA术后的时域和频域各项 参数均显著降低(P<0.01),两组术后心率变异性(HRV) 各项参数均较术前明显降低,成功组患者的SNDD、SDANN、rMSSD、 PNN50、HF、TF、LF、VLF 较对照组患者呈现不同程度的降低。结论：CPVA术可使心房出现去自主神经效应,进而增加去神经化 效应,有利于提高其治疗房颤的远期成功率。