慢性低氧所致肺动脉高压对大鼠肺动脉内蛋白激酶Cα的膜转位和蛋白表达量的影响

目的 通过观察慢性低氧所致肺动脉高压对大鼠肺动脉内蛋白激酶Cα(PKCα)的膜转位和蛋白表达量的影响,初步探讨PKCα在慢性低氧诱导大鼠肺动脉高压的发生和发展过程中所起的作用.方法 采用慢性常压低氧[氧浓度(10±0.1)％]大鼠肺动脉高压模型,将雄性SD大鼠随机分为正常对照组、低氧1d、3d、7d、14 d和21d组,检测大鼠右心室收缩压(RVSP)和右心室肥厚指数(RVHI),肺组织苏木精-伊红(HE)染色,应用蛋白免疫印迹和免疫组织化学的方法检测PKCα膜转位和蛋白表达水平的变化.结果 ①低氧1d、3d、7d、14 d和21d组与正常对照组相比,RVSP和RV/(LV+S)比值均明显增加(P＜0.05),低氧暴露3d、7d、14 d和21 d后大鼠肺动脉壁明显增厚;②PKCα的蛋白表达量在慢性低氧1d、3d、7d和14 d后比正常对照组明显下降(P＜0.05).结论 PKCα蛋白表达量的下调可能参与了慢性低氧诱导的大鼠肺动脉高压的发生和发展过程.     

蛋白激酶Mζ维持长时记忆机制的研究进展

背景突触的长时程增强（long-term potentiation,LTP）作为神经系统可塑性与学习记忆机制的经典电生理模型已得到广泛研究,LTP诱导阶段的分子机制已明确,但在记忆存储阶段维持信息的分子机制目前仍不清楚。蛋白激酶Mζ（protein kinaseMζ,PKMζ）是一种具有持续活性的蛋白激酶C的亚型,是维持LTP及长时记忆的必要分子。目的现就当前PKM‘维持长时记忆机制的研究及其进展作一综述。内容分别描述了PKMζ的概述、记忆存储的分子机制、记忆擦除和相关疾病4个方面的内容。趋势人们将对PKMζ在保存信息、维持长时记忆中的作用及其可能机制进行更深入的研究。     

HMGB1 与claudin-1 在重症急性胰腺炎肠黏膜屏障损伤中的表达及意义

目的：探讨高迁移率族蛋白B1（HMGB1）与claudin-1在重症急性胰腺炎（SAP）肠黏膜屏障损伤时的表达改变及意义。方法：将24只雄性Wistar大鼠随机均分为假手术组,SAP模型组（模型组）,SAP模型+HMGB1 抑制剂丙酮酸乙酯（EP）处理组（EP处理组）。SAP模型采用5%牛磺胆胆酸钠逆行胰管注射法,EP处理组于造模后2 h尾静脉注射EP溶液。各组大鼠于术后24 h处死,测定血浆淀粉酶（AMY）,内毒素（LPS）,血浆二胺氧化酶（DAO）水平;观察肠黏膜的病理学变化;免疫组织化学法观察肠黏膜claudin-1蛋白的表达;RT-PCR法检测肠组织HMGB1和claudin-1 mRNA的表达。结果：与假手术组比较,模型组大鼠血浆AMY,LPS和DAO水平均明显升高（均P<0.05）;小肠黏膜屏障受损,上皮细胞间紧密连接破坏;肠黏膜claudin-1蛋白表达降低,肠组织HMGB1 mRNA表达升高,claudin-1 mRNA的表达降低。与模型组比较,EP处理组肠组织HMGB1 mRNA表达降低,claudin-1蛋白与mRNA表达升高,各损伤指标均明显改善。结论：SAP肠黏膜屏障损伤可能与肠组织HMGB1表达升高,从而下调紧密连接蛋白claudin-1的表达有关;HMGB1抑制剂EP对SAP肠黏膜屏障损伤具有保护作用。

     

肝癌组织特异性蛋白磷酸酶2A催化性C亚基α亚型显性负性突变体表达载体抑制肝癌移植瘤生长的体内研究

目的 构建腺病毒为载体的肝癌组织特异性启动子驱动的蛋白磷酸酶2A催化性C亚基α亚型显性负性突变体(domina negative form of protein phosphatase 2A catalytic subunit α,DN-PP2Acα)表达载体,研究其对肝癌生长的影响.方法 前期研究已构建了甲胎蛋白(alpha-fetoprotein,AFP)基因增强子和磷酸甘油酸激酶(phosphoglycerate kinase,pgk)基因启动子组合形成的肝癌组织特异性AFpg启动子,并将AFpg启动子和DN-PP2Acα编码序列构建成AFpg启动子调控的DN-PP2Acα表达载体.将该载体重组到腺病毒载体中.Western印迹法检测PP2Ac表达水平.MTT法检测细胞生长.用荷瘤裸鼠进行体内研究.结果 AFpg启动子调控的DN-PP2Acα表达载体可特异性地使DN-PP2Acα表达于AFP阳性肝癌细胞HepG2,并抑制细胞及移植瘤的生长,而对AFP阴性肝癌细胞株SK-HEP-1、正常肝细胞株L-02和移植瘤的生长无明显影响.结论 AFpg启动子调控的DN-PP2Acα表达载体能特异性地抑制AFP阳性肝癌细胞的生长,可用于肝癌组织特异性基因治疗.     

Effects of a Serotonin S2-Receptor Blocker on Healing of Acute and Chronic Tendon Injuries

The beneficial effects of serotonin S₂-receptor blockers on healing skin and muscle ulcers and refractory lesions such as leprosy and diabetic and ischemic ulcers have been reported previously, but their mechanisms of actions are not clear. The present study sought to elucidate the action of an S₂-receptor blocker, metrenperone, on the healing of collagenase-induced injuries in superficial digital flexor tendons of two groups of rabbits. In one group, oral and topical therapy for 28 days with metrenperone, was started within 48 hr of a single acute injury. The animals were then left untreated for another 60 days, when it was found that most of the morphological, biochemical, and biomechanical characteristics of the healed tendons matched those of their normal uninjured controls. Injured, untreated controls showed poor healing. In the second group of animals, tendon injury was induced by four separate injections of collagenase at weekly intervals. The rabbits were left for another 60 days, before being treated with metrenperone for 26 days. This delayed treatment had no apparent effect on the biomechanical, biochemical, or morphological characteristics of the healing tendons. It appeared that metrenperone had a significant effect on collagen turnover and organization of scar tissue, but only while the inflammatory and fibroplastic processes were active in the early stages of healing. S₂-receptor blockers may, therefore, be of potential value for modulating repair in acutely injured collagenous tissue.     

Ivan Petrovich Pavlov

Twelve African green monkeys were implanted with recombinant human osteogenic protein-1 (rhOP-1) placed on a bovine bone-derived Type I collagen carrier to characterize healing in an ulna segmental bone defect model at 1, 3, 12, and 20 weeks postoperative. Defect healing was evaluated by plain film radiography, computed tomography (CT), magnetic resonance imaging (MRI), bone mineral density (BMD), and histologic analysis. Radiographically, new bone formation was observed as early as 3 weeks postoperative. By 6 weeks, new bone was visible in five of six defects. Increased quantity and mineralization of the new bone were apparent by 12 weeks. Reformation of the medullary cavity with appearance of marrow elements was demonstrated by CT and MRI at 20 weeks. BMD studies revealed a significant increase in the presence of bone with time. Histology at 1 week demonstrated that the implant material was well contained in the defect, and a proliferation of cells occurred at the defect borders. At 3 weeks cell proliferation continued and cell phenotype differentiation was recognized. By 12 weeks substantially less residual carrier was found in the defects, and calcifying tissues with plump chondrocytes, osteoblasts, and immature woven bone were observed. Areas of lamellar and woven bone were identified at 12 weeks, with advanced remodeling and revascularization observed at 20 weeks. The use of osteoinductive implants may provide an alternative to autologous and allogeneic bone tissue in the therapeutic approach to bone defects and promotion of fusion by eliminating the donor site morbidity associated with autogenous bone and the decreased efficacy and potential for disease transmission associated with allogeneic bone.     

PLK1在前列腺癌中的表达及其临床意义

目的 探讨丝氨酸/苏氨酸蛋白激酶1(PLK1)在前列腺癌中的表达及其临床意义.方法 应用免疫组化PV-9000两步法检测PLK1在51例前列腺癌组织,35例良性前列腺增生组织中的表达.结果 PLK1在前列腺癌组织中呈过表达,与良性前列腺增生组织相比,差异十分显著(P＜0.05).在前列腺癌组织高、中、低分化组的表达均有显著性差异(P＜0.05),在C～D期的表达明显高于A～B期的表达,有显著性差异(P＜0.05);其表达与病理Glease评分呈正相关(r=0.622,P＜0.01),与临床分期呈正相关(r =0.522,P＜0.01),与年龄、术前PSA无明显相关性.结论 PLK1在前列腺癌中高表达,与肿瘤的增值活性相关,在前列腺癌的发生发展中起重要作用,可能成为治疗前列腺癌的一个新的理想靶点.     

BONE-INDUCTIVE EFFICACY OF RECOMBINANT HUMAN BONE MORPHOGENETIC PROTEIN-2 EXPRESSED IN ESCHERICHIA COLI: AN EXPERIMENTAL STUDY IN RAT MANDIBULAR DEFECTS

Because to our knowledge the efficacy of prokaryotically expressed recombinant human bone morphogenetic proteins (rhBMP) to promote orthotopic osteogenesis has not previously been investigated, our aim was to test the efficacy of rhBMP-2 produced in Escherichia coli to promote bone healing in a standardised experimental bone healing model in rat mandibles. Different doses of rhBMP-2 were delivered in an absorbable collagen sponge carrier, and microporous barrier membranes were placed over half the number of defects in each treatment group, thereby making intraosseous cells the only recruitment source for new osteogenic cells. Results were evaluated by computerised image analysis after 12 and 24 days. The relative efficacy of rhBMP-2 preparations of different purity was also compared. E coli-produced rhBMP-2 stimulated bone healing, but its efficacy was estimated to be about one order of magnitude less than that of rhBMP-2 expressed in eukaryotic cells. We conclude that bacterially expressed rhBMP-2 is osteogenic in vivo, although higher doses will be required than of rhBMP-2 expressed in mammalian cell lines.     

SUSPENSION OF THE EYELID TO THE CHECK LIGAMENT OF THE SUPERIOR FORNIX FOR CONGENITAL BLEPHAROPTOSIS

A new surgical procedure for the treatment of all types of congenital blepharoptosis is described: suspension of the eyelid to the check ligament of the superior fornix. This is a dynamic suspension technique by which the check ligament, which is an extension of Tenon's capsule and normally inserts into the superior conjunctival fornix, is brought forward and sutured to the tarsus, which raises the eyelid. This technique does not sacrifice or add any tissue and is simple to repeat if necessary. Sixty-two patients were operated on using the technique and followed up for a mean of 23 months (range 3 months to 9.6 years). In a group of patients not operated on before for ptosis, 50 eyelids were raised with 74% normalisation, 22% improvement, and one eyelid each that showed only slight change or overcorrection. In a group of patients with 27 eyelids operated on before using other techniques, 67% of the eyelids were normalised, 30% were improved, and only one eyelid showed no change. In conclusion, this new technique has proved to be quite successful in raising the level of the upper eyelid in congenital blepharoptosis, with results at least comparable to those of most other techniques. The advantages with the check ligament over other techniques are the minimal trauma of the surgery, its simplicity, and its repeatability.