ENDOTHELIAL CELL CULTURE AND SEEDING OF PROSTHETIC VASCULAR GRAFTS: AN EXPERIMENTAL STUDY

Current synthetic vascular prostheses do not acquire lining of vascular endothelium in humans or dogs. Endothelial seeding of vascular grafts has been proposed as a means of reducing the thrombogenicity of these grafts. We examined feasibility of cultivating endothelial cells (EC) by tissue culture technique and their subsequent seeding onto small diameter polytetra fluoroethylene (PTFE) grafts. Twenty adult dogs underwent common carotid artery interposition with 4 mm PTFE grafts. Ten dogs received seeded and the remaining ten received unseeded grafts. Grafts were removed at 4 and 12 weeks and their gross/morphological features compared. Cumulative patency rates for seeded grafts were 70% as compared to unseeded ones 30%. Seeded grafts were completely surfaced with a mono-layer of endothelium by 4 weeks. Small graft patency appears to be related to the establishment of an endothelial surface, the development of which is clearly facilitated by seeding with autogenous endothelium.KEY WORDS: Endothelial cell seeding, Vascular grafts     

2-[对-(二甲氨基)苯乙烯]氯化甲基吡啶对大鼠心电图、豚鼠左心房收缩及乳头肌动作电位的影响

2-[对-(二甲氨基)苯乙烯]氯化甲基吡啶(DSPM-Cl),是由氯取代2-[对-(二甲氨基)苯乙烯]碘化甲基吡啶(DSPM)上的碘而得。本文应用心电图、机械收缩描记方法及细胞内标准微电极技术,研究DSPM-Cl对大鼠心电图(ECG)、豚鼠心房肌量效曲线及对豚鼠乳头肌快反应动作电位(AP)、高钾除极慢反应动作电位(SAP)的影响。结果显示,DSPM-Cl(2mg·kg^-1)对大鼠有明显的负性频率、负性传导作用,分别使PP间期、PR间期延长达66.2%(P<0.01),17.0%(P<0.01),50μmol·L^-1能明显抑制左心房收缩力,非竟争性拮抗Iso及CaCl₂对豚鼠左心房的正性肌力作用,PD^2'分别为4.6,4.34,100μmol·L^-1DSPM-Cl延长动作电位时程APD₉₀,有效不应期(ERP),降低高钾除极豚鼠乳头肌0期最大上升速率Vmax,其作用与Ver相似,提示DSPM-Cl可能为钙拮抗剂。     

Cloning of cDNA coding for connective tissue activating peptide III from a human platelet-derived lambda gt11 expression library

We report here the cloning of the cDNA coding for platelet connective tissue-activating peptide-III (CTAP-III) from a lambda gt11 expression library prepared using messenger RNA (mRNA) isolated from human platelets. The open reading frame of the clone coded for a protein with 128 amino acid residues. Since the precursor of CTAP-III, platelet basic protein (PBP is 94 amino acids long, the 5'-translated region of the cDNA codes for a leader sequence 34 amino acids long. This leader sequence, like the sequence of mature CTAP-III, shows significant homology to the sequence of platelet factor 4 (PF4), the only other platelet specific alpha-granule protein cloned until now, from a human erythroleukemic (HEL) cell line-derived cDNA library. These leader sequences are probably critical for targeting such proteins to the alpha-granule. Northern blot hybridization with platelet and megakaryocyte mRNA shows a single species mRNA of approximately 0.8 kb, suggesting that the corresponding cDNA is full length. The cloning of platelet specific CTAP-III provides additional evidence for the platelet specificity of the cDNA library used.