Liraglutide protects Rin‐m5f β cells by reducing procoagulant tissue factor activity and apoptosis prompted by microparticles under conditions mimicking Instant Blood‐Mediated Inflammatory Reaction

Instant Blood‐Mediated Inflammatory Reaction (IBMIR) occurs at the vicinity of transplanted islets immediately after intraportal infusion and is characterized by cytokine secretion, tissue factor (TF) expression, and ß cell loss. Microparticles (MPs) are cellular effectors shed from the plasma membrane of apoptotic cells. Modulation of the properties of ß cell‐derived MPs by liraglutide was assessed in a cellular model designed to mimic IBMIR oxidative and inflammatory conditions. Rin‐m5f rat β cells were stimulated by H₂O₂ or a combination of IL‐1β and TNF‐α. Cell‐derived MPs were applied to naive Rin‐m5f for 24 h. Apoptosis, MP release, TF activity, P‐IκB expression, and MP‐mediated apoptosis were measured in target cells. Direct protection by liraglutide was shown by a significant decrease in the oxidative stress‐induced apoptosis (18.7% vs. 7.6%, P < 0.0001 at 1 μm liraglutide) and cellular TF activity (?40% at 100 nm liraglutide). Indirect cytoprotection led to 20% reduction in MP generation, thereby lowering MP‐mediated apoptosis (6.3% vs. 3.7%, P = 0.022) and NF‐κB activation (?50%) in target cells. New cytoprotective effects of liraglutide were evidenced, limiting the expression of TF activity by ß cells and the generation of noxious MPs. Altogether, these data suggest that liraglutide could target pro‐apoptotic and pro‐inflammatory MPs in transplanted islets.     

椎板切除术后预防硬膜外瘢痕粘连的实验研究

为了寻找预防椎板切除后硬膜粘连的材料，选用家兔３０只，随机分为三组，每组１０只。每只作Ｌ３、Ｌ５椎板切除，形成两个大小１ｃｍ×０．５ｃｍ的缺损，一个缺损无任何覆盖，作空白对照；另一个缺损分别在硬膜外覆盖几丁糖、聚乳酸（ＰＬＡ）膜及明胶海绵，即为几丁糖组、ＰＬＡ膜组及明胶海绵组。术后２，４，６，８及１０周处死动物，通过肉眼、光镜及透射电镜，观察瘢痕生长及硬膜外粘连情况。结果表明，几丁糖组和ＰＬＡ膜组硬膜外均光滑、无增厚，硬膜外腔隙未见纤维组织增生或粘连；几丁糖具有明显抑制成纤维细胞生长和促进表皮细胞生长的作用，切口愈合快。而各组空白对照和明胶海绵组硬膜外纤维组织增生或粘连明显，硬膜外腔隙基本消失。认为，可生物降解吸收的几丁糖、ＰＬＡ膜能有效地预防椎板切除术后瘢痕粘连。     

Material Properties of Subchondral Bone from Patients with Osteoporosis or Osteoarthritis by Microindentation testing and Electron Probe Microanalysis

Cancellous bone from patients with osteoarthritis (OA) has a reduced material density and appears to be undermineralized. It is hypothesized that this will result in a reduction in the mechanical stiffness and strength of the bone matrix. In this study, bone was obtained from superior and inferior sites, subjected to relatively high and low loads, respectively, from human femoral heads retrieved after surgery for osteoporotic hip fracture (OP), or for hip arthroplasty due to OA. Microindentation testing was used to measure the hardness of cancellous bone at various depths from the subchondral bone plate. The elemental composition from immediately adjacent microscopic sites was determined using electron probe microanalysis (EPMA). Overall, OA bone was found to have hardness values that were 7% lower than those from OP bone. Bone from the inferior site was harder than that from the superior in both diseases except in female OP patients. There was no variation with depth below the subchondral plate and no difference between sexes. No difference was found in the composition of the bone from the different disease groups and no correlation was found between hardness and any of the composition measurements. Though only an indirect measurement of stiffness, the reduction in hardness values supports the hypothesis that OA bone has a reduced elastic modulus.     

Expression of type IV collagen in the developing human kidney

The distribution of α1–6 chains of type IV collagen (α1–6(IV)) in human fetal kidneys was examined by indirect immunofluorescence. By 11 weeks of gestation, α1, 2, 3, 4, and 6(IV) were already present, but α5(IV) appeared relatively late, at 21 weeks. α1(IV) and α2(IV) were present in all basement membranes, α3(IV) and α4(IV) were restricted to the glomerular basement membrane and parts of the tubular basement membrane. α5(IV) was distributed in the glomerular basement membrane, Bowman’s capsule, and parts of the tubular basement membrane. α6(IV) was present in the Bowman’s capsule, parts of the tubular basement membrane, and occurred in parts of the glomerular basement membrane at the early capillary loop stage, but disappeared during the later capillary loop stage. Received October 23, 1997; received in revised form and accepted February 6, 1998     

Changes in bone mineralization,architecture and mechanical properties due to long-term (1 year) administration of pamidronate (APD) to adult dogs

The goal of this study was to evaluate the effect of 1 year of APD administration on bone mineralization and bone mineral chemistry in the dog. Disodium pamidronate (APD) was given orally by gavage to mature beagle dogs at doses of 0, 2.5, 12.5 and 25.0 mg/kg per day (0.1% concentration for 12 months) as part of a long-term toxicity study. The os ilium and a vertebra were used to determine the mineralization profile and, subsequently, each density fraction was analysed chemically. Theribs were used to determine lattice parameters of the apatite crystal size using X-ray diffraction. The sternum was used to determine selected morphometric parameters using image analysis of specimen X-ray films and subsequently to determine mechanical properties using velocity-of-sound techniques. We found that for both the ilium and the vertebrae there was a significant shift of the mineralization profile towards greater density in a dose-related manner. This effect levelled off with the highest dose because the shift in mineralization profile correlated better with the square root of the dose than with the dose. Together with data on crystal size, which show an increase in lattice parameters and a decrease in crystal size with dose, our data lead us to believe that long-term administration of APD leads to an increase in bone mineralization without major changes in bone chemistry of Ca, Mg, and P and with a decrease in bone apatite crystal size. The image analysis shows a dose-related increase in trabecular bone volume and thickness. Furthermore, the elastic modulus of the trabecular bone increased linearly with the square root of the administered dose. These findings suggest that APD treatment increases the packing density of bone crystals and may decrease the solubility of bone mineral.     

添加特需营养素的营养支持对手术创伤后肠黏膜形态和屏障功能的影响

目的 探讨补充益生菌等特需营养素对手术应激后机体肠道屏障功能、上皮紧密连接及微生态的影响.方法 SD大鼠70只随机分成对照组、全肠外营养组(TPN组)、普通肠内营养组(EN组)和生态免疫肠内营养组(EEN组).建立创伤应激模型,接受等氮、等能量营养支持后光镜和电镜下观察肠黏膜形态和紧密连接,比较肠道细菌脏器易位率、肠道菌群数量及肠黏膜occludin蛋白免疫组织化学表达.结果 (1)电镜下观察,TPN组肠上皮损伤程度较严重,而EN组和EEN损伤程度较轻,肠上皮紧密连接、微绒毛较完整;光镜下chiu分级,TPN组和EN及EEN组比较差异有统计学意义(P<0.05).(2)EEN组和EN组肠道跨膜结合蛋白表达明显优于TPN组,且EEN和EN组间差异也有统计学意义(P<0.05).(3)EEN组和EN组肝、肺和肠系膜淋巴结的肠道细菌易位率低于TPN组,差异有统计学意义(P<0.05).(4)EEN组和EN组肠道内乳酸杆菌和双歧杆菌数量均高于TPN组,差异有统计学意义(P<0.05).结论 联合益生菌、肠道黏膜营养素、免疫营养素的营养支持能明显改善肠道微生态环境,维持肠道黏膜屏障和紧密连接,从而防止肠道菌群易位.     

聚乳酸生物可吸收膜在甲状腺手术中的应用

目的 探讨聚乳酸生物可吸收膜在甲状腺手术中应用的可行性和有效性.方法 甲状腺手术患者120例,将120例患者随机分为实验组和对照组.根据术中喉返神经显露程度,又分别分为单侧喉返神经显露组(A组)和双侧喉返神经显露组(B组)两个亚组.实验组患者将聚乳酸生物可吸收膜分别置于甲状腺手术创腔内喉返神经表面和颈前肌群表面与颈阔肌层之间.对照组不使用生物膜.对患者声音状况及颈部不适感进行术后定期随访.结果 (1)手术后当天,实验组和对照组患者均未出现声音嘶哑.术后3天后开始有患者出现声音嘶哑,为迟发性声音嘶哑.迟发性声音嘶哑发生率为3.33％ (4/120),实验组1例(占1.7％),对照组3例(占5.0％).采用GRBAS系统评分,实验组和对照组术后各个观察点声音嘶哑发生率比较,差异无统计学意义(P＞0.05).采用TVQ量表评分,实验组和对照组在术后1个月时比较,差异有统计学意义(P＜0.05);术后6个月时,仅B组比较,差异有统计学意义(P＜0.05);(2)第5天,实验组和对照组电子喉镜随访结果比较差异无统计学意义(P＞0.05);术后6个月比较,差异有统计学意义(P＜0.05).(3)术后1个月时,实验组颈部不适感发生比例和严重程度均低于对照组,差异有统计学意义(P＜0.05);术后6个月时比较,差异无统计学意义(P＞0.05).结论 聚乳酸生物可吸收膜在甲状腺手术中,具有保护喉返神经,促进声音恢复的作用,可减轻患者术后颈部牵扯及挛缩感.     

前列腺特异性膜抗原启动子增强子调控重组质粒的构建及鉴定

目的探讨前列腺特异性膜抗原(PSMA)启动子和增强子调控目的基因表达的前列腺细胞特异性，了解增强子增强转录效率的能力。方法采用PCR方法从前列腺癌细胞DNA中分别扩增PSMA启动子和增强子序列，先后克隆到含有报告基因绿色荧光蛋白(GFP)的质粒载体，脂质体介导基因转染不同癌细胞并观察GFP在不同细胞的表达情况。结果成功构建质粒pEGFP—PS—MAPro和pEGFP-PSMAEP，转染结果显示PSMA表达阳性的LNCaP细胞中存在GFP的有效表达，且pEGFP—PSMAEP的调控转录能力较pEGFP—PSMAPro强20倍。结论PSMA启动子增强子调控GFP表达的重组质粒的构建证明该调控序列具有前列腺细胞特异性，增强子能够明显增强启动子的转录效率，增加了目的基因的表达水平。PSMA启动子和增强子的共调控可以保证基因表达的强度和细胞特异性，为前列腺癌基因靶向性治疗研究提供实验依据。     

survivin启动子与PSMA启动子/增强子在前列腺癌细胞系中的转录活性比较

目的:通过研究并比较前列腺特异性膜抗原(PSMA)基因启动子、增强子和survivin基因启动子在不同前列腺癌细胞系(LNCaP和PC-3细胞)中的转录活性,为前列腺癌的靶向性基因治疗提供依据。方法:采用PCR扩增PSMA基因的启动子、增强子和survivin基因启动子,分别克隆入pGL3-Basic,脂质体转染前列腺癌细胞和张氏肝细胞,检测各启动子在细胞中的转录活性。结果:survivin基因启动子在前列腺癌细胞中均具有较强活性,均明显高于PSMA启动子/增强子,其中S2pro启动活性最强,达到CMV启动子活性的1/3,然而,survivin启动子及PSMA启动子/增强子在肝细胞系中几乎不表达。结论:survivin启动子在前列腺癌细胞中具有较强启动活性,可望成为新的前列腺癌靶向性基因治疗工具。