烧伤脓毒症早期膈肌内泛素基因和蛋白的表达变化及意义

目的 :探讨烧伤脓毒症时大鼠膈肌内蛋白降解信号分子——泛素的基因和蛋白表达变化及意义。方法 :大鼠背部 30 %总体表面积 度烫伤后 ,立即腹腔注射内毒素 (6 mg/ kg)制成烧伤脓毒症动物模型 ,随机分为脓毒症 2 h和 6 h组 ,另设对照组 ,每组 9只。通过 Northern杂交检测大鼠膈肌内泛素 m RNA表达的变化 ;免疫组织化学法测定膈肌内泛素蛋白水平的表达。结果 :烧伤脓毒症大鼠伤后 2和 6 h膈肌内泛素 m RNA2 .4 kb条带和 1.2 kb条带的表达较对照组均显著增强 ,且呈持续升高现象 ,其中 2 .4 kb条带的表达增强更明显 ,差异有显著性 (P均 <0 .0 1)。烧伤脓毒症大鼠伤后 2和 6 h膈肌内泛素蛋白的表达较对照组也显著增强 ,以伤后 6 h增强更明显。结论 :烧伤脓毒症早期膈肌内泛素基因和蛋白表达即显著增强 ,且呈持续升高现象 ,提示膈肌内泛素系统活性上调 ,蛋白降解增强 ,这对进一步从肌组织蛋白代谢角度研究烧伤脓毒症时膈肌功能变化及其对呼吸功能的影响机制有重要意义。     

烧伤早期大鼠骨骼肌组织泛素转录表达的变化研究

目的：研究烧伤后大鼠骨骼肌组织泛素－蛋白毒体（ubiquitin-proteasome)蛋白降解途径组成成分中泛素表达的变化,探讨烧伤后骨骼肌蛋白降解的增强与泛素－蛋白酶体蛋白降解途径表达变化间的关系。方法：借助烫伤大鼠动物模型,利用骨骼肌离体孵育系统,应用氨基酸自动分析仪测定孵育液和骨骼肌组织中酪氨酸（Tyr)和3－甲基组氨酸（3－MH）量的变化,用RNA印迹技术（Northern blot)方法测定骨骼肌组织中泛素mRNA表达水平。结果：烧伤后大鼠骨骼肌释放Tyr和3－MH增多,以3－MH增加显著;烧伤后骨骼肌组织中泛素－2．4kb的mRNA表达上调明显。泛素mRNA表达增加量与Tyr和3－MH增加量间均呈显著正相关。结论：烧伤后大鼠骨骼肌蛋白降解明显增强,其机制与泛素－蛋白酶体蛋白降解途径在转录水平被激活密切相关。     

脓毒症大鼠肝组织基因表达的研究

目的筛选脓毒症大鼠肝组织中与正常组织差异表达的基因并进行初步功能分析。方法雄性Wistar大鼠30只，随机分为模型组和空白对照组，每组15只。参照盲肠结扎穿孔术（CLP）制备大鼠脓毒症模型，采用含有4096个大鼠基因cDNA克隆的表达谱基因芯片，检测并分析脓毒症大鼠肝组织在CLP后24h的基因表达变化，并以计算机软件筛选出差异表达的基因。结果CLP后24h共筛选出522条与空白对照组相比出现差异的基因，占基因芯片总点数的12．7％，其中244条基因表达下调，278条基因表达上调。结论脓毒症导致的多器官功能障碍综合征（MODS），涉及到一系列与细胞周期、调控、细胞凋亡、免疫相关基因、各种基本生物化学物质代谢酶类基因和能量代谢相关基因、血液相关基因、癌基因相关基因、生长因子类基因、应激反应类基因、细胞信号转导相关基因、DNA结合转录和转录调节因子相关基因、DNA复制与修复相关基因、蛋白质翻译与修饰、加工、降解相关基因等相关的基因表达异常；采用基因芯片检测技术有利于全面揭示脓毒症中的基因表达模式，快速高效地发现新的研究目标和基因治疗途径。     

Elevated thrombopoietin in plasma of burned patients without and with sepsis enhances platelet activation

Summary.  Background:  Thrombopoietin (TPO) is a humoral growth factor that does not induce platelet aggregation per se , but enhances platelet activation in response to several agonists. Circulating levels of TPO are increased in patients with sepsis and are mainly related to sepsis severity. Objectives:  To investigate the potential contribution of elevated TPO levels in platelet activation during burn injury complicated or not by sepsis. Methods:  We studied 22 burned patients, 10 without and 12 with sepsis, and 10 healthy subjects. We measured plasma levels of TPO, as well as leukocyte-platelet binding and P-selectin expression. The priming activity of plasma from burned patients or healthy subjects on platelet aggregation and leukocyte-platelet binding, and the role of TPO in these effects were also studied in vitro . Results:  Burned patients without and with sepsis showed higher circulating TPO levels and increased monocyte-platelet binding compared with healthy subjects. Moreover, TPO levels, monocyte-platelet binding and P-selectin expression were significantly higher in burned patients with sepsis than in burned patients without sepsis. In vitro , plasma from burned patients without and with sepsis, but not from healthy subjects, primed platelet aggregation, monocyte-platelet binding and platelet P-selectin expression. The effect of plasma from burned patients with sepsis was significantly higher than that of plasma from burned patients without sepsis. An inhibitor of TPO prevented the priming effect of plasma from burned patients. Conclusions:  Increased TPO levels may enhance platelet activation during burn injury and sepsis, potentially participating in the pathogenesis of multi-organ failure in these diseases.     

脓毒症大鼠心脏组织基因表达变化的研究

目的 应用基因芯片技术初步分析脓毒症大鼠心脏组织细胞基因表达谱的变化.方法 雄性Wistar大鼠30只被随机分为脓毒症组和对照组,每组15只.采用盲肠结扎穿孔术(CLP)制备大鼠脓毒症模型,以透射电镜下心脏组织检查鉴定模型.应用含有22 523个大鼠基因cDNA克隆的表达谱基因芯片进行检测,以Cy3和Cy5两种荧光信号强度结果 比值均>2.0或<0.5的基因为脓毒症表达差异基因,用计算机软件筛选并分析脓毒症大鼠心脏组织术后24 h的基因表达变化,并初步分析表达差异基因与脓毒症之间的关系.结果 与对照组比较,脓毒症组大鼠心脏组织共筛选出418个出现差异表达的基因,占基因芯片总点数的1.86%,其中表达上调者200个,表达下调者218个.在已知功能基因中表达上调者84个,下调者74个,与应激反应、细胞信号转导、糖皮质激素受体、免疫反应、胰岛素样生长因子、细胞物质能量代谢等方面的相关基因功能有关.结论 脓毒症大鼠心脏组织出现一系列基因表达异常,用基因芯片检测技术可快速分析.     

脓毒症小鼠肝肺组织细胞因子mRNA表达的比较

目的：比较脓毒症时肝脏与肺脏在细胞因子表达上的差异。方法：盲肠结扎穿孔（ＣＬＰ）造成脓毒症小鼠模型,假手术组接受同样手术操作但不行ＣＬＰ。用逆转录－聚合酶链反应（ＲＴ－ＰＣＲ）的方法检测了脓毒症小鼠肝、肺组织中多种细胞因子〔促炎症细胞因子肿瘤坏死因子－α（ＴＮＦ－α）、白介素－β（ＩＬ－１β）、ＩＬ－６,抗炎症细胞因子ＩＬ－４〕ｍＲＮＡ的表达。结果：ＣＬＰ后,肺组织中促炎症细胞因子ＴＮＦ－α、ＩＬ     

Expression of proteasome subunit isoforms during spermatogenesis in Drosophila melanogaster

In this study, we sought to identify and characterize all the proteasome genes of Drosophila melanogaster. Earlier work led to the identification of two genes encoding alpha4-type 20S proteasome subunit isoforms that are expressed exclusively in the male germline. Here we extend these results and show that six of the 20S proteasome subunits, and four of the 19S regulatory cap subunits, have gene duplications encoding male-specific isoforms. More detailed analyses of two of these male-specific subunits (Prosalpha3T and Prosalpha6T), using GFP-tagged reporter transgenes, revealed that they are predominantly localized to the nucleus at later stages of spermatogenesis and are present there in mature, motile sperm. These results suggest a possible role of a 'spermatogenesis-specific' proteasome in sperm differentiation and/or function.     

脓毒症对不同类型骨骼肌蛋白降解率的影响及其机制初探

目的：厂家脓毒症时不同类型骨骼肌蛋白降解率的变化,分析其可能的机制。方法：大鼠腹腔注射内毒素制成脓毒症模型,随机分为攻击后2、6、12和24小时组,每组设正常对照;利用骨骼肌充分氧供离体孵育系统,采用氨基酸全谱分析仪测定毒症大量伸趾长肌（EDL）和比目鱼肌（SOL）蛋白降解率。用放射免疫分析（RIA）方法测定大鼠血浆中糖皮质激素含量。结果：内毒素攻击后大鼠EDL总蛋白降解率和肌纤维蛋白降解率在2和6小时较正常对照组明显增加,肌纤维蛋白九解率增加1－2倍,6小时达峰值,12和24小时均无明显变化。大鼠SOL总蛋白降解率和肌纤维蛋白解率在内毒素攻击后均未见显著变化。内毒素攻击后不同时间点血浆糖皮质激素含量较正常对照组均显著增加（P均＜0．01）。EDL肌纤维蛋白降解率与血浆糖皮质激素含量呈显著正相关（r＝0．982,P＜0．01）。结论：不同类型骨骼肌对脓毒症刺激的反应不同,快同纤维对脓毒平刺激比慢红肌纤维敏感;血浆中糖皮质激素浓度增加是导致脓毒症骨骼肌蛋白降解增强的重要因素之一。     

胰岛素强化治疗对烫伤脓毒症兔骨骼肌蛋白高降解的调节及其机制

目的探讨胰岛素强化治疗对烫伤脓毒症骨骼肌蛋白高降解的调节及机制。方法雄性日本大耳白兔30只，按随机数字表法将动物分为烫伤组（S组）、烫伤脓毒症组（SS组）、烫伤治疗组（SI组）、烫伤脓毒症治疗组（SSI组）以及对照组（C组），每组6只动物。S组使用沸水致背部30％总体表面积Ⅲ度烫伤；SS组同样条件致伤后，立即腹腔注射内毒素（2mg／kg）模拟烫伤脓毒症。SI组和SSI组从伤后2h开始经静脉泵入胰岛素，使血糖值始终波动在4．4～6．1mmol／L。通过高效液相-荧光法检测伸趾长肌和尿内三甲基组氨酸（3-MH）的含量；采用核糖核酸印迹法（Northern blot）检测伸趾长肌内泛素基因的表达变化。结果S组和SS组伸趾长肌和尿内3-MH含量较C组均显著升高（P均〈0．01）；SI组和SSI组伸趾长肌和尿内3-MH含量分别较S组和SS组显著降低（P均〈0．01）。S组和SS组伸趾长肌内编码泛素的基因转录水平则较C组显著增强（P均〈0．01）；SI组和SSI组伸趾长肌内编码泛素的基因转录水平分别较S组和SS组显著降低（P均〈0．01）。结论严重烫伤特别是合并内毒紊攻击后早期伸趾长肌细胞内泛素-蛋白酶体途径活性即显著增强，蛋白降解率显著增加。胰岛素强化治疗能通过基因水平抑制细胞内泛素-蛋白酶体途径的活性，有效降低烫伤脓毒症时骨骼肌蛋白高降解。     

The effect of insulin in combination with selenium on blood glucose and GLUT4 expression in the cardiac muscle of streptozotocin‐induced diabetic rats

We evaluated the effect of a combination of low doses of insulin (1 U/kg/day) and selenium (180 μg/kg/day) on general physiological parameters and the level of glucose transporter (GLUT4) in the cardiac muscle of streptozotocin‐induced diabetic rats. Diabetic rats were treated with insulin, selenium and a combination of insulin and selenium for 4 weeks. The levels of blood glucose and hemoglobin A1c were estimated; the level of the GLUT4 in the cardiac muscle was examined by immunoblotting and immunohistochemistry. Insulin in combination with selenium could significantly lower blood glucose and HbA1c levels and could restore disturbances in GLUT4 level in the cardiac muscle. The treatment with insulin was only partially effective in the restoration of diabetic alterations. We conclude that there was cooperation between insulin and selenium, and that the treatment of diabetic rats with combined doses of insulin and selenium was effective in the control of blood glucose and correction of altered GLUT4 distribution in diabetic rat hearts.