成人正常股骨解剖测量及其在膝关节置换的临床意义

[目的]为膝关节置换准确截骨和获得良好的下肢力线，对中原地区成人股骨干进行相关测量。[方法]（1）选取47根成人正常股骨标本，拍摄正、侧位数码照片，进行定点、划线、测量五角。（2）实体上确定股骨髓内定位杆进针点的位置：[结果]（1）各角度值反映了股骨远端在冠状位和矢状位的解剖形态。（2）进针点与股骨滑车中心水平距离平均为6．21mm，与后交叉韧带止点前缘距离平均为6．70mm。[结论]（1）股骨远端1／3段与股骨近端1／3段向外侧、前侧成角，且前倾角度大于外翻角度。所以股骨远端在决定股骨髓内定位杆的位置时，冠状面上的力线对位和矢状面上的对位均很重要。（2）全膝关节置换术中确定进针点可参考股骨滑车中心和股骨髁后交叉韧带止点的位置。     

基底动脉缝隙连接蛋白的分布

目的：探讨正常脑血管缝隙连接蛋白的分布。方法：采用RT—PCR、免疫组化方法测定多种缝隙连接蛋白在大白兔基底动脉的表达。结果：(1)RT—PCR发现大白兔基底动脉血管组织中至少存在Xx45、Cx43、Cx40和Cx37四种缝隙连接蛋白mRNA表达；(2)免疫组化证实Cx45和Cx43主要分布于血管内皮，平滑肌细胞间末见Cx45和Cx43的染色。结论：大白兔基底动脉血管组织存在丰富的缝隙连接蛋白的表达，与体内其它弹力血管相比，缝隙连接蛋白的分布模式有其特殊性。     

保留假体清创治疗人工膝关节置换术后感染的作用

[目的]探讨保留假体清创在治疗人工膝关节置换术后感染中的可行性、适应证、成功和失败的相关因素以及注意事项.[方法]回顾分析本院自1990～2004年收治的人工膝关节置换术后感染病例,发现9例病人在治疗开始时曾尝试采用清创灌注冲洗的方法保留假体,对这9例病人进行总结,并对可能影响清创是否成功的因素进行统计学分析.[结果]本组9例病人中4例保留了假体,平均随访18个月（10～25个月）,感染均无复发.由于病例数较少,本研究针对可能影响清创成功的因素未能得出有意义的统计学结果,但从结果看：急性感染清创容易成功,而慢性感染则很难获得成功;表皮葡萄球菌成功率较高,金黄色葡萄球菌均失败;表面膝置换成功率较高,而铰链膝置换则难以获得成功;出现症状后应该抓紧时间进行清创,延误的时间越长,成功的可能性越低.[结论]保留假体清创在人工膝关节置换术后感染的治疗中有一定的应用价值,对于术后急性感染病人和术后晚期急性血源性感染病人应尝试进行保留假体清创治疗,但必须严格掌握手术时机及适应证才能获得成功.     

强直性脊柱炎股骨近段形态学改变对全髋关节置换术假体选择的意义

目的分析强直性脊柱炎股骨近段的形态学改变,及其改变对全髋关节置换术假体选择的意义。方法1999年1月~2004年6月,将13例(16髋)强直性脊柱炎患者设为选择组,患者均已出现关节强直,需行全髋关节置换术。另16例(19髋)为对照组,为非强直性脊柱炎患者而拟行全髋关节置换术。两组患者均摄髋关节正侧位X线片,测量Singh指数、髓腔张开指数、皮质形态指数及皮质骨指数,并进行统计学分析。结果选择组Singh指数、髓腔张开指数及皮质形态指数分别为3.81±0.54、2.63±0.41及2.02±0.38,对照组分别为4.63±0.62、3.03±0.27及2.76±0.28,两组比较差异均有统计学意义(P<0.05)。选择组皮质骨指数为1.69±0.69,对照组为2.12±0.24,两组比较差异无统计学意义(P>0.05)。选择组患者髓腔呈烟囱型10例13髋,普通型3例3髋;对照组烟囱型3例3髋,普通型13例16髋。结论强直性脊柱炎的全髋关节置换术应采用骨水泥型人工关节假体,并根据患者髓腔形态使用定制型骨水泥假体,以达到更好的近段固定效果。对于有严重骨质疏松者应按关节翻修术处理。     

WHERE ARE THE GATES IN GAP JUNCTION CHANNELS?

1. In the formation and function of gap junction channels two types of gates ought to be discriminated: the docking gate and the channel gates proper. The docking gate is involved in the transformation of a closed hemichannel to a patent gap junction channel. By definition the trigger mechanism for this gate and maybe even the gate itself is contained within the extracellular loops of the gap junction proteins, the connexins. The channel gates proper determine the open and closed states of the complete gap junction channels. 2. Probing the docking gate by mutagenesis of connexins and by synthetic peptides indicates that this gate is the consequence of complex interactions between a large fraction of the amino acids comprising the extracellular loops. Probably both inter- and intra-molecular interactions are involved, and disulfide exchange may be entailed in the stabilization of the open and closed states. 3. Of the various effectors on the channel gate(s) the voltage effects have obtained the most scrutiny to date. The response of gap junction channels and hemichannels is diverse, the various channels respond differently to transjunctional and membrane potential. No equivalent to the S4 segment representing the voltage sensor in other voltage dependent ion channels is present in the connexin sequences, instead mutations in various segments of connexins have been reported to affect the voltage dependence of gap junction channels. To understand the complexity of voltage effects on gap junction channels, non-connexin peptides may need to be considered as voltage sensors or as modifiers thereof.     

Catastrophic failure of modular Zirconia—Ceramic femoral head components after total hip arthroplasty

Catastrophic failure of two zirconia—ceramic modular femoral heads occurred, despite the theoretical improved toughness of zirconia—ceramic relative to alumina—ceramic. This experience led the authors to return to cobalt—chromium as the metal of choice for articulation against polyethylene in total hip arthroplasty.     

The role of primary total hip replacement for the treatment of the displaced femoral neck fractures

Summary The management of displaced intracapsular fractures of the hip is still controversial because of the high incidence of complications after internal fixation or hemiarthroplasty. To avoid some of these complications we have used primary total hip replacement for independently mobile patients over 65 years of age.Of 49 patients who were interviewed an average of 4.6 years after total hip replacement, 81.6% had excellent or good results as assessed by the Harris Hip Score. At that time two hips had been revised and another converted to Girdlestone due to deep infection. The survival of the prostheses was at 5 years 91.3%.It is concluded that total hip replacement is an established method of management for a selected group of patients with this injury, but further prospective studies are needed in order to define the groups of patients that benefit the most.     

全髋置换术对下肢短缩的治疗

目的：探讨全髋关节置换术对肢体短缩的纠正。方法：2000年2月～2002年12月,将30例接受单侧全髋关节置换术的患进行了研究：男19例,女12例。术前通过临床及对骨盆前后位X线片的测量评估双下肢不等长的程度,然后利用模板预测髋臼及股骨假体的置入位置，估计股骨颈的截骨水平以维持双下肢等长。术中先标记并测量股骨近端至髋臼上方两标记之间的距离，而后在术前估计的位置进行股骨颈截骨。置入假体试模之后再次测量两标记之间的距离和检查髋周软组织的张力、关节活动和drop-kick试验。最后通过调整股骨头假体颈部或头部长度进一步进行纠正。结果：22例肢体短缩2cm以上的病人中。术后双下肢等长(双下肢相差在1cm内)20例，2例仍有短缩，1例短3cm，另1例短1．5cm。8例肢体短缩在1～2cm的病人术后肢体完全等长。全部病人没有髋关节的僵硬和疼痛，活动范围恢复75％以上26例，恢复50％～75％4例。结论：通过术前测量评估，术中定位测量。术中软组织充分松解，置入假体试模后再次测量和检查髋周软组织的张力、关节活动和drop-kick试验,可以有效地治疗下肢的短缩。     

全反式维甲酸对急性白血病骨髓基质细胞GJIC功能的影响

目的 观察在全反式维甲酸(ATRA)作用下急性白血病骨髓基质细胞间连接蛋白43(Cx43)表达的变化及通讯功能的改变.方法 体外培养急性白血病骨髓基质细胞,传代后加入ATRA(1×10-5mol/L),采用细胞免疫化学及流式细胞术检测加药前后Cx43表达的变化;采用细胞划痕染料传输技术比较二者间隙连接细胞间通讯(GJIC)功能的差异.结果 急性白血病骨髓基质细胞加药前后,细胞免疫化学方法检测Cx43表达的阳性率分别为47.2%±2.04%和54.5%±5.66%,流式细胞术检测Cx43的含量为38.75%±23.95%和49.5%±5.46%;加药后染料可传输至4～5列细胞,明显高于加药前(P＜0.01).结论 加入ATRA后,急性白血病骨髓基质细胞间通讯功能较加药前明显增强.     

In the Context of Risk: Supportive Adults and the School Engagement of Middle School Students*

Abstract: Many students in the United States, particularly those from lower income or racially/ethnically diverse families, are exposed to clusters of risk factors that have a negative impact on school success. This study examined the association between the number of supportive and caring adults in the home, school, and neighborhood and the school engagement of students in early adolescence. Results revealed that students who reported such supportive adults in their lives also reported higher levels of psychological and behavioral engagement with their schooling. Additionally, including measures of environmental risk factors in analytical models of the school engagement of middle school students reduced otherwise statistically significant race/ethnicity differences to nonsignificance. Implications for practice and policy are discussed.