肿瘤抑素抗血管活性相关肽对宫颈癌Hela细胞生长和转移抑制作用的实验研究

目的研究改造后的血管生成抑制相关肽（21肽）抗血管生成活性及对人宫颈癌Hela细胞皮下移植裸鼠模型的抑制作用,探讨其抑瘤作用机制。方法2005年8月至2006年2月哈尔滨医科大学第一临床医学院进行Hela细胞株皮下接种裸鼠造模,21肽治疗3周后,处死动物剥离肿瘤,称重并计算抑瘤率。免疫组化方法检测21肽对肿瘤组织的微血管密度（MVD）、增殖细胞核抗原（PCNA）和血管内皮生长因子（VEGF）的影响。结果21肽组平均抑瘤率可达51.89%,肿瘤组织微血管密度明显降低,与对照组比较差异有统计学意义（P〈0.05）;21肽组肿瘤组织的PCNA、VEGF呈低表达,与对照组比较差异有统计学意义（P〈0.05）。结论21肽具有显著的抗血管生成活性,可明显地抑制裸鼠宫颈癌细胞的生长,其抑制宫颈癌的作用机制可能与其降低新生血管形成和调解血管生成相关因子的表达有关。     

关于肽类生长因子对神经发育作用及其机制的认识

肽类生长因子对神经系统发育发挥着重要的调控作用，与神经退行性疾病的发生和发展也密切相关，在研究过程中要运用哲学原理作指导，充分认识肽类生长因子结构和功能的多样性、其受体及其作用机制的复杂性，处理好基础研究与实践的辨证关系，从单纯分析研究走向系统研究。     

胎盘多肽注射液辅助治疗老年晚期非小细胞肺癌的临床研究

[目的]研究采用胎盘多肽注射液辅助治疗老年晚期非小细胞肺癌(NSCLC)患者的临床效果.[方法]临床纳入84例本院收治的晚期NSCLC老年患者,按随机数字表法分为两组,每组42例.采用单药化疗方案进行治疗者作为对照组,另42患者在上述基础上加用胎盘多肽注射液治疗作为观察组,比较两组疗效.[结果]对照组总有效率、临床受益率分别为14.29％、69.05％与观察组16.67％、73.81％相比较差异无显著性(P＞0.05).治疗前两组患者免疫功能差异无显著性(P＞0.05);治疗后,观察组患者CD3、CD4、CD4/CD8以及NK细胞活性均优于对照组(P＜0.05).治疗前两组患者生活质量差异无显著性(P＞0.05);治疗后,观察组KPS、QOL评分明显高于对照组(P＜0.05).观察组不良反应发生率为14.29％,明显低于对照组28.57％(P＜0.05).[结论]采用胎盘多肽注射液辅助治疗老年晚期NSCLC效果显著,不良反应低,患者免疫功能明显提高,值得临床应用及推广.     

载脂蛋白模拟肽的研究进展

载脂蛋白模拟肽是利用现代生物技术合成的与载脂蛋白功能相当而分子量更小的一类多肽.应用这类模拟肽治疗动脉粥样硬化及其相关性疾病已成为近年来心血管疾病治疗领域的研究热点.本文就载脂蛋白模拟肽最新研究进展做一综述.     

Regions of botulinum neurotoxin A light chain recognized by human anti-toxin antibodies from cervical dystonia patients immunoresistant to toxin treatment. The antigenic structure of the active toxin recognized by human antibodies

This work was aimed at determining the BoNT/A L-chain antigenic regions recognized by blocking antibodies in human antisera from cervical dystonia patients who had become immunoresistant to BoNT/A treatment. Antisera from 28 immunoresistant patients were analyzed for binding to each of 32 overlapping synthetic peptides that spanned the entire L-chain. A mixture of the antisera showed that antibodies bound to three peptides, L11 (residues 141-159), L14 (183-201) and L18 (239-257). When mapped separately, the antibodies were bound only by a limited set of peptides. No peptide bound antibodies from all the patients and amounts of antibodies bound to a given peptide varied with the patient. Peptides L11, L14 and L18 were recognized predominantly. A small but significant number of patients had antibodies to peptides L27 (365-383) and L29 (379-397). Other peptides were recognized at very low and perhaps insignificant antibody levels by a minority (15% or less) of patients or had no detectable antibody with any of the sera. In the 3-dimensional structure, antibody-binding regions L11, L14 and L18 of the L-chain occupy surface areas and did not correlate with electrostatic potential, hydrophilicity/hydrophobicity, or temperature factor. These three antigenic regions reside in close proximity to the belt of the heavy chain. The regions L11 and L18 are accessible in both the free light chain and the holotoxin forms, while L14 appears to be less accessible in the holotoxin. Antibodies against these regions could prevent delivery of the L-chain into the neurons by inhibition of the translocation.     

Stephen C. Woods: a precocious scientist

To investigate the early scientific development of Steve Woods, I reviewed his research during the first decade after he received his doctoral degree in 1970. The main parts of his research program were conditioned insulin secretion and hypoglycemia, Pavlovian conditioning of insulin secretion before a scheduled access to food, and basal insulin as a negative-feedback signal from fat mass to the brain. These topics were pursued with experimental ingenuity; the resulting publications were interesting, clear, and rhetorically effective. Although the theoretical framework for his experiments with insulin was homeostatic, by the end of the decade he suggested that classic negative-feedback homeostasis needed to be revised to include learning acquired by lifestyle. Thus, Woods functioned as a mature scientist from the beginning of his research—he was very precocious. This precocity also characterized his teaching and mentoring as recalled by two of his students during that time, Joseph Vasselli and Paul Kulkosky. The most unusual and exemplary aspect of his precocity is that the outstanding performance of his first decade was maintained during the subsequent 30 years.     

Proteomic identification of an MHC-binding peptidome from pancreas and breast cancer cell lines

Peptides bound to cell surface MHC class I molecules allow the immune system to recognize intracellular pathogens and tumor-derived peptides. Our goal was to learn what the immune system “sees” on the surfaces of tumor cells by acid-eluting peptides from HLA molecules for extended time periods. We determined how long peptides would continue to elute over time from a pancreatic tumor cell line, Panc-1, and a breast cancer cell line, MCF-7, at pH 3.0 in citrate buffer while monitoring viability. Both cell lines demonstrated greater than 90% viability after 25 min at pH 3.0. Panc-1 remained >90% intact after 45 min at pH 3.0. Acid eluted peptide sequences were identified using LC–MS/MS and searching the NCBI refseq database. The total number of peptides eluted peaked between 40 and 45 min for Panc-1, but continued to increase over time from MCF-7. A total of 131 peptides were identified from Panc-1 while 101 peptides were identified from MCF-7 elutions. Two classes of peptides were eluted: (1) 8–10 amino acid peptides fitting the HLA-binding motifs of each cell line, and (2) peptides longer than 10 amino acids containing HLA-binding motifs of each cell line. W6/32 antibody affinity purification of intact MHC molecules after papain cleavage of MHC class I from tumor cell surfaces also indicated that peptides longer than 10 amino acids bind to class I proteins. A peptide–MHC-refolding assay further substantiated the binding of longer peptides to HLA-A*0201. Our findings provide sequences and gene names of peptides presented by MHC class I molecules from common pancreas and breast cancer cell lines. We utilized a novel refolding assay to demonstrate that peptides longer than the canonical 8–10 amino acids commonly bind in MHC class I cell surface molecules.     

青霉源抗菌肽类霉肽素的体外抑菌活性研究

目的研究抗菌肽类霉肽素（AF）的体外抑菌活性。方法通过抑菌圈法和二倍稀释法检测AF的抗菌谱和对金黄色葡萄球菌的MIC;通过检测在AF中传代菌的敏感性确定细菌是否容易对AF产生抗药菌;将AF和细菌在不同温度和pH环境作用后检测抑菌活性,明确AF发挥活性的最适温度和pH值。结果AF对大部分供试细菌和抗药菌有效,对金黄色葡萄球菌的MIC为0．8mg／ml,金黄色葡萄球菌在AF中传代200代后敏感性不变。在14℃到30℃之间AF的抑菌活性随温度升高而降低,在pH3到pH10之间AF的活性随pH值升高而降低。结论AF是一种对抗性菌有效的广谱抗菌肽,而且不容易诱导细菌产生抗药性。     

黏附肽改性纯钛表面成骨细胞的早期黏附能力研究

目的 对纯钛表面钝化态氧化膜进行生物化学活化改性,探讨生物化学改性对钛表面成骨细胞黏附的影响.方法 24个纯钛试件打磨抛光后均分为4组,每组6个;纯钛组不处理,碱-热处理组行碱-热处理,溶胶涂层组行碱-热处理+溶胶涂层处理,黏附肽组行碱-热处理+溶胶涂层+黏附精氨酸-甘氨酸-天冬氨酸-丝氨酸肽(Glycine-Tyrosine-Arginine-Glycine-Asparticacid-Serine,GYRGDS)处理.使用X射线光电子能谱(X-ray photoelectron spectroscopy,XPS)、傅里叶变换红外光谱计(Fourier transform infrared spectrometer,FTIR)分析各组钛表面化学元素及功能基团组成;在各组钛试件表面接种成骨细胞,经2.05 Pa流体剪切力作用30 min、1 h、2 h,计算细胞残留率.结果 碱-热处理组钛表面富含大量活性羟基,溶胶涂层组钛表面富含大量羟氧基团.黏附肽组钛表面经XPS及FTIR分析检测到酰胺峰,显示GYRGDS肽成功固定于钛表面.流体剪切力作用30 min、1 h和2 h后黏附肽组钛表面的成骨细胞残留率(分别为93.0%、54.4%、34.4%)均高于相应时间点其他组.结论 GYRGDS肽修饰后的钛表面成骨细胞黏附稳定性均优于非GYRGDS肽修饰组.     

Evolution and phylogeny of the corticotropin-releasing factor (CRF) family of peptides: Expansion and specialization in the vertebrates

New sequence data on CRF family members from a number of genomes has led to the modification of our understanding of CRF evolution in the Metazoa. The corticotropin-releasing factor (CRF) family of peptides include four paralogous lineages in jawed vertebrates; CRF, urotensin-I/urocortin/sauvagine, urocortin 2 (Ucn2) and urocortin 3 (Ucn3). CRF and the urotensin-I/urocortin/sauvagine group represent a gene duplication from one lineage, whereas Ucns 2 and 3 are the result of a gene duplication in the other paralogous lineage. Both paralogous lineages are the result of a gene duplication from a single ancestral peptide that occurred after the divergence of the tunicates from the ancestor that led to the evolution of chordates and vertebrates. The presence of a single CRF-like peptide in tunicates and insects suggests that a single CRF-like ancestor was present before the separation of deuterostomes and protostomes. Currently there is no strong evidence that indicates that CRF-like peptides were present in metazoan taxa that evolved before this time although the structural similarity between some CRF peptides in insects, tunicates and vertebrates with the calcitonin family of peptides hints that prior to the formation of deuterostomes and protostomes the ancestral peptide possessed both CRF and calcitonin-like structural attributes. Here, we show evidences of conservation of CRF-like function dating back to early prokaryotes. This ancestral CRF–calcitonin-like peptide may have initially resulted from a horizontal gene transfer event from prokaryotes to a protistan species that later gave rise to the metazoans.