Molecular cloning and characterization of a Ca2+/calmodulin-insensitive adenylyl cyclase from rat brain.

Biochemical, immunological, and molecular cloning studies have suggested the existence of multiple forms of adenylyl cyclase (EC 4.6.1.1). An adenylyl cyclase cDNA clone (type II) was isolated from a rat brain library and found to encode a protein of 1090 amino acids that was homologous to but distinct from the previously described Ca2+/calmodulin-stimulated adenylyl cyclase from bovine brain. Expression of the type II cDNA in an insect cell line resulted in an increased level of adenylyl cyclase activity that was insensitive to Ca2+/calmodulin. Addition of activated Gs alpha protein to type II-containing membranes increased enzyme activity. The mRNA encoding the type II protein was expressed at high levels in brain tissue and at low levels in olfactory epithelium and lung. The existence of multiple adenylyl cyclase enzymes may provide for complex and distinct modes of biochemical regulation of cAMP levels in the brain.     

微创固定系统治疗膝关节周围复杂骨折

目的应用微创固定系统(less invasive stabilizing system,LISS)治疗膝关节周围复杂骨折,探讨其手术适应证及疗效。方法2003年12月至2004年6月应用LISS技术治疗膝关节周围复杂骨折41例,男29例,女12例;年龄24￣67岁,平均40.6岁。胫骨近端骨折28例,股骨远端骨折13例。多发伤22例(53.7%),陈旧性骨折6例(14.6%),翻修手术1例。新鲜骨折均采用关节面切开复位、干骺端闭合复位及经皮钢板固定技术;陈旧性骨折及翻修手术采用有限切开及经皮钢板固定技术。结果单侧LISS手术时间平均87.2min。全部病例随访13～21个月,平均16个月。3例股骨远端骨缺损患者平均于术后21.3周(19～24周)行植骨术,植骨术后22.3周(18～24周)骨折愈合。其余患者愈合时间平均15.1周(11～23周),完全负重时间平均16.8周(12～25周)。术中发生螺钉脱落1例,提拉复位装置断裂1例,工具断裂1例,螺钉未能按计划置入2例。术后发生关节面复位丢失1例,无感染、内固定松动、断裂及失败病例。按照Rasmussen骨折复位评分标准,优31例、良10例。术后1年关节活动范围2.4°～95.6°。术后1年HSS评分平均88.4分(58～98分),其中优27例、良10例、中3例、差1例,优良率90.2%。结论LISS为膝关节周围复杂骨折提供了一种新的治疗方法,特别是对常规方法难以处理的骨折。但其手术理念及手术技术与传统手术不同,还需要一定病例与随访的积累才能确定其疗效。     

影响肝外伤手术死亡的危险因素分析

目的分析影响肝外伤手术死亡的危险因素,探讨其临床意义。方法根据AAST和ISS标准,回顾性分析90例肝外伤手术病例,对影响手术死亡的危险因素进行单因素比较和Logistic回归分析。结果死亡15例,其中Ⅲ级2例、Ⅳ级4例、Ⅴ级9例,总体手术死亡率17%。Ⅳ~Ⅴ级肝外伤手术方式的单因素比较提示:清创性肝切除术的相对危险度是0.73;而规则性肝切除术、肝静脉或肝后下腔静脉修补术相对危险度分别是1.32、1.52。Logistic回归分析提示:ISS分会和术中失血量是影响手术死亡率的2个独立因素。结论ISS分值、术中失出血量和手术方式是影响肝外伤手术死亡的3个重要因素,娴熟的手术技能和合理的手术方式可以减少术中出血量和降低手术死亡率。     

胶质细胞瘤复发前后Cyclin D1和P16的表达

目的　探讨CyclinD1,P16在胶质瘤复发前后表达改变及其意义。方法　采用免疫组织化学LsABC法对 4 5例复发胶质瘤瘤组织、瘤旁脑组织和 10例正常脑组织CyclinD1,P16蛋白表达进行检测 ,统计分析CyclinD1,P16表达水平与胶质瘤分级、肿瘤复发的关系。结果　正常脑组织 ,瘤旁脑组织和胶质瘤组织CyclinD1表达依次升高 ,而P16的表达依次下降 ;肿瘤复发CyclinD1表达增强 ,P16的表达减弱。结论　CyclinD1与P16的表达与胶质瘤恶性进程和复发密切相关。     

长沙市小学生焦虑障碍现状调查

目的　初步了解小学儿童焦虑障碍的患病现况。方法　使用焦虑性情绪障碍筛查表 (SCARED)调查长沙市某小学 2～ 6年级的 5 6 5名小学生 ,并对量表总分≥划界分 (2 3分 )的学生进行面谈。结果　在 5 6 5名小学生 (男生2 90名 ,女生 2 75名 )中 ,SCARED筛查阳性的有 14 0名 ,占总人数的 2 4 78%。使用中国精神障碍分类与诊断标准 (第三版 ) (CCMD 3)对筛查阳性者进行面谈 ,发现符合焦虑障碍诊断标准的 32例 (男 15 ,女 17) ,患病率为 5 6 6 % ,其中儿童分离性焦虑症 7例 ,患病率为 1 2 4 % ;儿童广泛焦虑症 11例 (1 95 % ) ;儿童恐惧症 10例 (1 77% ) ;儿童社交恐惧症 14例(2 4 8% ) ;有 8例存在 2～ 3种焦虑障碍共病 ;无 1例诊断为学校恐怖症、选择性缄默症和惊恐发作。结论　在儿童中焦虑情绪存在较普遍 ,这对儿童的学习、行为、自我意识造成不良影响 ,应予以积极干预。     

维生素D衍生物联合供者骨髓细胞输注诱导异基因大鼠心脏移植免疫耐受

目的 探讨同种异基因心脏移植后免疫耐受的诱导。方法 建立大鼠颈部异位心脏移植模型，按分组分别给予门静脉输注供者骨髓细胞(DBMC)(B组)、骨化三醇灌胃(C组)、输注DBMC及骨化三醇灌胃(D组)以及环孢素A(CsA)灌胃(E组)。观察移植心脏的存活时间及心肌组织病理改变，测定心肌组织中肿瘤坏死因子及细胞间粘附分子-1 mRNA的表达以及血清钙、磷浓度，进行受者与供者及无关第三品系大鼠脾细胞混合淋巴细胞培养(MLR)。结果 D组移植心脏的存活时间较其它各组显著延长(P＜0．05)；术后7d，C组、D组、E组受者脾细胞均能显著抑制供者及第三方无关供者脾细胞作为刺激细胞引起的MLR；D组手术前后血磷、血钙浓度的差异无显著性(P＞0．05)；各组急性排斥反应的程度，D组最轻；D组肿瘤坏死因子及细胞间粘附分子-1 mRNA的表达受到显著抑制，与对照组(A组)、B、C组比较，差异有显著性(P＜0．05)。结论 骨化三醇灌胃联合DBMC输注可显著延长移植心脏的存活时间，二者具有协同作用。     

Cell transplantation to improve ventricular function in the failing heart

Current therapies for congestive heart failure are limited in efficacy or in applicability. Cardiac cell transplantation offers a novel therapeutic approach to improve heart function. Although significant progress has been made over the past decade in the development of cell transplantation, only recently have investigators studied the changes in ventricular function following cell transplantation. This review article describes the latest research developments, evaluates recent studies of ventricular function after cell transplantation, and discusses the future directions of cell transplantation as a new therapy to ‘repair broken hearts’.     

结肠CT扫描技术初探

目的 :通过分析比较结肠扫描不同充填剂与不同体位的方法 ,探讨出最佳充填剂与最佳体位以提高结肠 CT扫描质量。方法 :分别对 4 0例结肠 CT扫描病人采用不同的充填剂 ,与不同的体位 ,评价不同的充填剂与不同体位的优缺点。结果 :水作为充填剂组病灶显示情况明显优于泛影萄胺组且伪影少 ,选择不同体位组图像质量也明显优于常规体位组。结论 :结肠 CT扫描时应首选水作为充填剂 ,根据病变不同选择不同的体位 ,有利于图像质量的提高     

A quantitative analysis of valgus torque on the ACL: a human cadaveric study.

The loads needed to elicit a positive pivot shift test in a knee with an anterior cruciate ligament (ACL) rupture have not been quantified. The coupled anterior tibial translation (ATT), coupled internal tibial rotation (ITR), and the in situ force in the ACL in response to a valgus torque, an inherent component of the pivot shift test, were measured in 10 human cadaveric knee specimens. Using a robotic/universal force-moment sensor testing system, valgus torques ranging from 0.0 to 10.0 Nm were applied in nine increments on the intact and ACL-deficient knee in flexion ranging from 0 degrees to 90 degrees. At 15 degrees of knee flexion, the coupled ATT and ITR were significantly increased in the ACL-deficient knee when compared to the intact knee. Coupled ATT increased a maximum of 291% (6.7 mm, p<0.05), while coupled ITR increased a maximum of 85% (5.1 degrees, p<0.05). At 30 degrees, the increases in coupled ATT and ITR were significant at valgus loads of 3.3 Nm and greater with a maximum increase in coupled ATT of 137% (6.3 mm, p<0.05) and a maximum increase in coupled ITR of 38% (3.6 degrees, p<0.05). At 45 degrees, coupled ATT increased significantly (maximum of 69%, 4.4 mm, p<0.05), but only at torques > or =6.7 Nm. The in situ force in the ACL was less than 20 N for all flexion angles when a torque between 3.3 and 5.0 Nm was applied. Low valgus torque elicited tibial subluxation in the ACL-deficient knee with low in situ ACL forces, similar to a positive pivot shift test. Thus, application of a valgus torque may be suitable to evaluate ACL-deficient and ACL-reconstructed knees, since subluxation can be achieved with minimal harm to the ACL graft. This work is important in understanding one load component needed for the pivot shift examination; further studies quantifying other load components are essential for better comprehension of the in vivo pivot shift examination.     

Effect of link protein concentration on articular cartilage proteoglycan aggregation

Previous work has shown that alterations in proteoglycan aggregates are among the first changes detected with aging, disuse, and degeneration of articular cartilage, yet the cause or causes of these alterations remain unknown. To determine if differences in link protein concentration can explain alterations in the assembly, size, and stability of articular cartilage proteoglycan aggregates, we isolated proteoglycan monomer (aggrecan) and link protein from adult bovine articular cartilage and then assembled proteoglycan aggregates from aggrecan and 0.8% hyaluronan relative to aggrecan weight, in the presence of 0, 2, 4, 6, 8, 10, 15, and 20% concentrations of link protein relative to aggrecan weight. We determined the amount, sedimentation coefficient, and stability of the aggregates by analytical ultracentrifugation and measured their dimensions by electron microscopy with use of the monolayer technique. Increased aggregate size, as determined by ultracentrifugation, was directly correlated with an increased number of aggrecans per aggregate and with increased hyaluronan length, as determined by electron microscopy. The concentration of link protein significantly influenced aggregation: concentrations of 6–8% produced maximum aggregation, aggregate stability, and uniformity of aggrecan spacing; concentrations greater than 10% led to the formation of superaggregates (aggregates with sedimentation velocities greater than 100 S that may result from linking two or more hyaluronan filaments) but decreased aggregate stability; and concentrations of less than 4% link protein significantly decreased aggregation, the size and stability of aggregates, and the regularity of aggrecan spacing. The latter observations suggest that a decline in the concentration of link protein could decrease the organization and stability of the articular cartilage matrix.