Continuous flow synthesis of peptides using a polyacrylamide gel resin (Expansin™)

The continuous flow syntheses of endothelin 1, proendothelin 2. ATP binding site of the CDC2 kinase 3, and fragment 18-30 of an actin 4, have been performed by using a polyacrylamide gel resin Expansin? (about 0.6 mmol NH₂/g) with the glycolamidic ester handle as labile anchorage. In addition, we report here a method of air oxidation which reduces the formation of side-products related to the formation of intermolecular disulfide bridges.     

Intranasal treatment with ovalbumin but not the major T cell epitope ovalbumin 323–339 generates interleukin-10 secreting T cells and results in the induction of allergen systemic tolerance

BACKGROUND: Nasal administration of major peptide T cell epitopes gives contradictory data on the induction of peripheral tolerance. OBJECTIVE: To compare the prophylactic effect of intranasal treatment (INT) on the development of an allergic response, using either ovalbumin (OVA) or its major T cell epitope OVA 323-339 (OVAp). METHODS: BALB/c mice were treated intranasally with OVA or OVAp and subsequently immunized s.c. with OVA. Anti-OVA-specific antibody, T cell proliferation and cytokine responses were analysed. In an adoptive transfer model using OVAp specific TCR transgenic (Tg) T cells from D011.10 mice, in vivo tracking and characterization of transferred T cells in the cervical, inguinal and bronchial lymph nodes (BLN) and in the spleen were determined by FACS analysis. RESULTS: Prophylactic INT with OVA induced T cell tolerance towards subsequent OVA s.c. immunizations, inhibiting OVA specific T cell proliferation, IgE and IgG1 production, in contrast to INT with OVAp, which was unable to induce tolerance. In vivo analysis of transferred OVA-specific TCR Tg T cells showed that INT with OVA induced a preferential activation of T cells in BLN, as opposed to a broad, systemic activation with OVAp. In vivo, OVAp INT led to faster and more sustained cell division cycles than OVA INT. Ex vivo, tolerance to OVA was associated with the generation of IL-10 secreting CD4(+) T cells in BLN of OVA-treated mice only. CONCLUSION: INT with OVA but not with OVAp led to regional (as opposed to systemic) T cell activation and the induction of IL-10 secreting CD4(+) T cells in BLN, potentially critical steps in the induction of T cell-specific tolerance via the nasal route.     

脑利钠肽在评价功能性单心室患者TCPC后心功能中的价值及意义

目的探讨脑利钠肽(BNP)在评价功能性单心室患者行全腔静脉-肺动脉连接术(TCPC)后心功能中的价值及其意义。方法选择2004年4~11月间连续在我科随访的TCPC后患者11例(TCPC组),男7例,女4例;年龄8.2±4.1岁;随访时间2.1±1.6年。按照改良R oss标准对临床心功能评分。采集外周静脉血3m l,用酶标免疫法测定血浆BNP浓度。其中6例同期用磁共振成像(M R I)测定心功能,对BNP做相关因素分析。9人健康儿童作为正常对照(对照组)。结果(1)TCPC组血浆BNP水平为400pg/m l(IQR 200-690),较对照组的110 pg/m l(IQR 90-190)增高(P=0.003);(2)M R I测定结果:TCPC组6例患者舒张期末容量指数为65.76±8.65 m l/m2,收缩期末容量指数为31.90±6.36 m l/m2,心搏出量指数为39.09±11.76 m l/m2,射血分数(EF)为0.52±0.06,心脏指数(C I)为2.38±0.58 L/m in.m2,心肌质量指数为103.49±21.57 g/m2,心肌质量/心室舒张期末容量为1.57±0.24;(3)TCPC组BNP水平与手术时年龄呈明显正相关(r=0.632,P=0.041);BNP水平与上述M R I指标、R oss评分、性别、年龄、脉搏血氧饱和度(SpO2)及主心室类型等因素无关。结论TCPC后近2年神经内分泌系统仍处于应激状态,BNP增高可能与TCPC后特有的血流动力学状态有关;血浆BNP水平不能作为正确评估TCPC后心功能状态的指标。     

正常人颈段脊柱结构内CGRP和SP阳性神经纤维的分布

目的 为深入探讨颈肩痛的发病机理。方法 用免疫组织化学方法观察人颈段脊柱结构内CGRP和SP阳性神经末梢存在的情况。结果 人颈段脊柱结构的纤维层内均有CGRP和SP免疫反应阳性神经末梢存在，多数神经末梢独立行走，呈树枝状或念珠状，少量神经末梢交织网状。结论 CGRP和SP可能参与了人颈段脊柱结构的伤害性感觉信息的传递。当人颈段脊柱结构的神经末梢受刺激时，可能引起CGRP和SP的释放和传递，这可能是引起原发性颈肩痛的原因之一。     

背根神经节内P物质、降钙素基因相关肽免疫阳性神经元与阴茎包皮系带感觉信息的传递

目的：探讨背根神经节（DRG）内P物质（SP）、降钙素基因相关肽（CGRP）免疫阳性神经元与阴茎包皮系带感觉信息传递之问的关系。方法：通过荧光金（FG）逆行标记对大鼠阴茎包皮系带内神经末梢的来源作追踪定位，并结合SP、CGRP免疫荧光标记法，研究大鼠DRG内FG标记阳性神经元中SP、CGRP免疫阳性神经元的形态和分布。结果：FG逆行标记结果发现，大鼠阴茎包皮系带内的神经末梢起源于第6腰髓对应的背根神经节（L6-DRG）和第1骶髓对应的背根神经节（S1-DRG）的神经元。对这些神经元分别作SP、CGRP免疫荧光标记后发现，标记细胞大小不等，分别呈深红色和深绿色，沿神经束成行排列或散在分布。FG／SP、FG／CGRP双标记阳性细胞均为中小型，其数量分别占FG逆行标记阳性细胞总数的1／3和1／2，FG／SP／CGRP三标记阳性细胞占FG逆行标记阳性细胞总数的1／5。结论：大鼠L6-DRG和S1-DRG内的SP、CGRP免疫阳性神经元可能参与阴茎包皮系带感觉信息的传递。     

国产重组人脑钠素与硝普钠用于心脏手术围术期处理的对比研究

目的 对重组人脑钠素（rhBNP）用于心脏手术围术期处理的可行性、安全性和有效性进行初步观察，并与硝普钠的作用进行比较。方法 选择择期心脏手术病人22例，随机分为rhBNP组（B组）和硝普钠（SNP）组（s组），每组11例。比较rhBNP与SNP对病人血流动力学和肝肾功能的影响。结果 与给药前和S组比较，B组用药后15、30、60、120和180min各点心输出量增加显著（P〈0．05，P〈0．01）；B组与给药前比较，给药后即刻、15、30和60min时点外周血管阻力下降显著（P〈0．05）；给药后即刻、15和30点与S组比较，下降显著（P〈0．05）。B组肺毛细血管楔压（PCWP）与用药前比较，用药后即刻、15、30、60、120和180min下降显著（P〈0．05，P〈0．01）；与S组比较，给药后30、60、120和180min差异有统计学意义（P〈0．05，P〈0．01）。S组PCWP与用药前比较，用药后60min、120min和180min下降显著（P〈0．05）。B组与输注rhBNP前以及S组比较，平均动脉压、心率和中心静脉压差异均无统计学意义。输注rhBNP后病人24h尿量明显增加。用药过程中以及30d后进行电话随访，未见药物不良反应。结论 rhBNP用于心脏手术围术期处理是可行的，具有改善心功能和稳定循环的作用。     

APP17肽对APP转基因小鼠学习记忆能力和海马神经细胞凋亡的影响

目的观察APP(-βamyloid precursop protein,APP)17肽(APP695中319-335肽段)对APP转基因小鼠(APP695V717I)学习、记忆能力及海马神经细胞凋亡的影响。方法3月龄的APP695转基因小鼠随机分为模型组和APP17肽治疗组,正常对照组采用月龄和性别与之相匹配的C57BL/6J小鼠。APP17肽治疗组给予皮下注射APP17肽,每只每次0.34μg,每周3次;模型组和正常对照组给予等体积NS。应用水迷宫试验观察小鼠学习、记忆功能的变化,以流式细胞技术分析海马神经细胞凋亡率和线粒体膜电位的变化。结果(1)水迷宫试验结果显示,模型组小鼠存在明显学习和记忆功能障碍,其第3、4、5天游完全程的时间[(93.22±16.35)、(86.73±20.26)、(77.13±29.35)s]和错误反应次数[(6.63±2.16)、(5.81±2.13)、(5.33±1.41)次]均较正常对照组[分别为(70.89±20.19)、(61.25±21.88)、(54.63±16.92)s和(5.01±1.93)、(2.97±0.96)、(2.31±1.01)次]增多(P<0.05);APP17肽治疗组小鼠的行为学障碍明显轻于模型组(P<0.05),其上述水迷宫检测结果与正常对照组比较差异无统计学意义。(2)与正常对照组小鼠海马神经细胞凋亡发生率[(3.13±1.19)%]和线粒体膜电位[(176.39±13.88)mV]比较,模型组凋亡发生率[(8.06±2.31)%]显著增加(P<0.01)而线粒体膜电位[(97.51±15.73)mV]明显降低(P<0.01);APP17肽治疗组检测结果与正常对照组接近,海马神经细胞凋亡发生率[(4.38±1.26)%]低于模型组(P<0.01),线粒体膜电位[(168.35±19.29)mV]高于模型组(P<0.01)。结论APP695转基因小鼠存在学习和记忆功能障碍,且其海马神经细胞凋亡率增加,线粒体膜电位降低;APP17肽能够明显改善该转基因小鼠的学习和记忆能力,其作用机制可能是通过稳定线粒体膜电位及抑制凋亡发生而实现。     

采用组织芯片技术分析胃癌组织中胃泌素和胃泌素释放肽的表达

目的研究胃癌组织中胃泌素(GAS)、胃泌素释放肽(GRP)的表达及其临床意义。方法采用组织芯片技术制作60例胃癌组织芯片,同时用生物素-链霉菌卵白素检测系统(SP)免疫组织化学方法检测胃癌组织芯片中GAS、GRP的表达。结果60例胃癌中GAS阳性率为30.0%;GRP阳性率为11.7%。中、低分化胃癌GAS、GRP阳性率高于高分化胃癌(P<0.05);印戒细胞癌GAS、GRP阳性率显著高于其他组织学类型胃癌(P<0.05);胃癌GAS、GRP阳性表达与淋巴结转移相关(P<0.05)。结论应用组织芯片大规模高效检测临床组织样本是可行的,具有快速、方便、经济、准确的特点。     

RGD多肽接枝聚复合导管桥接神经缺损的实验研究

Objective To investigate the effect of RGD peptide conjugated poly[ LA-(Glc-Lys) ]/βTCP/PLA nerve conduit for bridging peripheral nerve regeneration defect. Methods Forty-five male Wister rots were randomly divided into 3 groups, with 15 rats each. A 10 mm defect was created in the right sciatic nerve. In group A the gap was bridged by PLA tube. In group B RGD peptide conjugated poly[ LA-(Glc-Lys) ]/β-TCP/PLA nerve conduit was used to repair the defect. Autologous nerve graft was done in group C which served as control. Twelve weeks postoperatively nerve regeneration was evaluated by gross observation,electrophysiology, muscle weight and muscle morphometry of triceps surae, and ultrastructure of the regenerating nerve. Results Twelve weeks after the operation, nerve conduction velocity and muscle weight recovery of group B were better than those of group A. The differences were statistically significant( P < 0.05). There was no significant difference between group B and group C ( P > 0. 05). The results of histology and ultrastructure showed that nerve regeneration in group B and group C was significantly superior to that in group A.Conclusion RGD peptide conjugated poly[LA-(Glc-Lys)]/β-TCP/PLA conduit can achieve similar results in repairing sciatic nerve defect to that of autogentic nerve graft. It may be an ideal material to repair nerve defect.     

阿片受体对体外循环缺血再灌注损伤心肌的保护作用

目的 通过建立猪体外循环(CPB)心肌缺血再灌注(MI/R)模型对δ阿片受体激动剂脑腓肽(DADLE)介导的CPB MI/R损伤早期时相和后时相的心肌保护作用进行探讨,以期为临床心肌保护提供理论和实验依据.方法 将24只成年家猪随机分为对照组、早期时相和后时相组,每组8只常规建立CPB模型,主动脉阻断同时灌注改良St.Thomas停搏液.每组于CPB前、主动脉开放时、CPB结束时、停机后1、2 h检测冠状静脉窦血肌钙蛋白(TnT)含量,相应时间点监测左室舒张末期压(LVEDP)和左室内压最大变化速率(±ap/dt<,max>),于停机后2h取左心室心肌,进行心肌组织Gia蛋白的表达、PKC的表达和ATP含量的测定.并应用透射电镜观察心肌再灌注损伤超微结构的变化.结果 (1)和早期时相和后时相组相比,对照组心功能指标明显下降.(2)对照组的TnT较早期时相和后时相组明显升高,ATP含量明显降低.(3)和对照组相比,早期时相和后时相组Gin蛋白和PKC的表达更为明显.(4)透射电镜下早期时相和后时相组的心肌超微结构损伤均较对照组明显轻微.结论 (1)和CPB前1 h应用一次DADLE而产生的早期时相心肌保护作用相比,CPB前48 h和24 h两次应用DADLE引发的后时相心肌保护作用更为显著.(2)Gi蛋白-PKC途径可能是δ阿片受体介导的猪CPB NI/R损伤心肌保护中一条重要的信号传导途径.