准直器验收测试方法研究

目的单晶体γ相机测试标准中平面系统空间分辨率和灵敏度不能有效反映准直器的质量问题，需寻找更好的方法进行准直器验收测试。方法通过测试２０只平行孔准直器平面系统均匀性，并辅以测试断层均匀性和直接观察准直器内部结构，对准直器进行验收。结果平面系统均匀性是检测准直器的有效指标。对于系统泛源图像出现较明显非均匀区域，或准直器积分均匀性＞３％的准直器为验收不合格。结论系统均匀性测试为准直器验收中最佳方法。     

Synergistic effects of malononitrilamides (FK778, FK779) with tacrolimus (FK506) in prevention of acute heart and kidney allograft rejection and reversal of ongoing heart allograft rejection in the rat

BACKGROUND: The effects of tacrolimus (FK506) and malononitrilamides (MNA) (FK778 and FK779) monotherapy and combination therapy were examined in prevention of acute heart and kidney allograft rejection and reversal of ongoing acute heart allograft rejection in the rat. METHODS: Brown Norway (RT1n)-to-Lewis (RT11) and ACI (RT1a)-to-Lewis (RT11) combinations were used, respectively, for heart and kidney transplantation models. Immunosuppressants were administered orally from day 1 to day 14 for preventing acute rejection and from day 4 to day 34 after transplantation for the reversal of ongoing acute rejection. RESULTS: In the prevention of acute heart rejection model, recipient rats treated with monotherapy of tacrolimus or MNA (FK778, FK779) showed a dose-related prolongation of mean survival time (MST) compared with naive control rats (P<0.01). The mean survival time in combination therapy of tacrolimus (FK506) and FK778 indicated that an additive to synergistic interaction was produced when compared with the respective monotherapies (combination index [CI]=0.631-1.022). These results were reproducible with tacrolimus and FK779 combination therapy (CI=0.572-0.846). Furthermore, similar results were also found in the prevention of acute kidney allograft rejection in the rat (CI=0.137-0.516). In the reversal of ongoing acute heart allograft rejection, combination therapy of tacrolimus and FK778 demonstrated a strong synergistic interaction (CI=0.166-0.970) compared with monotherapy of tacrolimus or FK778. CONCLUSIONS: Combination therapy of tacrolimus and MNA (FK778, FK779) produces synergistic effects in prevention of acute heart and kidney rejection and reversal of ongoing heart allograft rejection in the rat.     

术前肌注咪唑安定对听觉诱发电位指数和血浆内皮素的影响

目的　比较和评价麻醉手术前使用咪唑安定或苯巴比妥钠对患者焦虑、顺行性遗忘、听觉诱发电位指数和血浆内皮素的影响。方法　 4 0例年龄 2 0～ 6 0岁、ASAⅠ～Ⅱ级的择期手术患者 ,随机分为两组。Ⅰ组麻醉前 30min肌肉注射苯巴比妥钠 0 1g +阿托品 0 5mg(n =2 0 ) ;Ⅱ组于麻醉前 30min肌肉注射咪唑安定 0 0 6mg/kg(41～ 6 0岁 )和 0 0 8mg/kg(2 0～ 4 0岁 ) +阿托品 0 5mg(n=2 0 )。分别于用药前后测定患者收缩压 (SBP)、舒张压 (DBP)、心率 (HR)、指脉搏血氧饱和度(SpO2 )、呼吸频率 (RR)、焦虑视觉模拟评分 (AVAT)、听觉诱发电位指数 (AEPI)、顺行性遗忘程度和血浆内皮素 (ET 1)浓度变化。结果　两组患者在用药前后SBP、DBP、HR、SpO2 和RR无明显变化(P >0 0 5 ) ;Ⅰ组在用药前后AVAT、AEPI和ET 1浓度变化无差异 (P >0 0 5 ) ,顺行性遗忘率 2 0 % ;Ⅱ组用药后 30minAVAT、AEPI和ET 1浓度均低于用药前 (P <0 0 5 ) ,顺行性遗忘率为 75 %显著高于Ⅰ组 (P <0 0 1)。结论　与苯巴比妥钠相比 ,咪唑安定可有效减轻患者麻醉手术前焦虑情绪 ,获得更好的顺行性遗忘和镇静效果 ,且能减轻麻醉手术前应激反应     

Microsim医学模拟培训系统在实习学员临床思维培训中的应用

目的　评估Microsim 医学模拟培训系统在实习学员临床思维培训中的价值及可行性。方法　以2009级、2010级临床医学五年制96名学员为研究对象,随机分组为两组,每组48人。A组在呼吸内科临床实习3周后通过Microsim医学模拟培训系统进行病例学习1周,B组在呼吸内科临床实习4周。观察两组学员实习结束后临床思维考核成绩及教学满意度,数据应用SPSS 17.0进行统计分析,计量资料进行配对t 检验,计数资料采用χ2检验。结果　Microsim医学模拟培训系统评估报告得分[（89.37±7.18） vs. （61.95±15.34）],组间差异有统计学意义。学员临床思维能力考核中得分,分析问题能力[（89.95±4.02） vs. （75.51±6.34）]、处理问题能力[（78.81±8.09） vs. （59.67±9.33）]、处理流程[（86.74±6.59） vs. （70.39±7.05）]和处理效果[（88.61±8.16） vs. （63.54±11.48）]方面,２组间差异有统计学意义。但沟通交流得分[（82.47±5.23） vs. （84.09±3.72）],组间无统计学差异。89.6%（43人）的学员认为Microsim医学模拟培训系统能明显提高临床思维能力,但只有58.3%（28人）的学员认为能巩固基本理论知识。结论　Microsim医学模拟培训系统可提高学员临床思维能力及临床综合处置能力,可作为临床实习教学的有效补充。     

CT、ECT在脊柱关节病诊断中的价值

目的 探讨CT、ECT核素骨显像对脊柱关节病（SpA)的诊断价值。方法 对临床诊断为SpA患者63例（其中强直性脊柱炎26例，未分化脊柱关节病37例）同时进行骶髂关节CT扫描和ECT全身及骶髂关节局部显像。结果 CT对未分化脊柱关节病检查阳性率为24.3%(9/37)。远低ECT检查阳性率64.9%(24/37)；ECT对强直性脊柱炎的诊断阳性率为53.8%(14/26)。结论 ECT核素骨显像早期诊断SpA较CT敏感，具有重要价值。     

Bone growth patterns in Chinese children and adolescents: a 6-year follow-up study provides evidence for sexual dimorphism and tracking

Summary We prospectively examined bone growth patterns in 894 children aged 6–17 years at the baseline visit, with a 6-year follow-up. Results show bone “tracking” over a six-year interval and sexual dimorphism of bone attained levels and timing of peak bone growth. Our findings underscore childhood and adolescence as critical periods for building bone and developing gender differences. Introduction Bone growth patterns were prospectively examined in 894 Chinese children (496 males), aged 6–17 yrs, from a population-based twin cohort. Whole-body bone area (BA), bone mineral content (BMC), and bone mineral density (BMD) were measured by DEXA at baseline and a 6-yr follow-up. Methods Graphic smoothing plots and generalized estimating equations were used to model bone attained levels, growth, and “tracking”. Results Attained levels of BMC and BA increased curvilinearly with age. Male attained levels were higher than females after age ∼15 yr, but BMD was lower between 13–17 yrs (Tanner stage I to IV). In both genders, peak BMC and BMD growth lagged ∼2 yrs behind peak BA growth, which lagged 2 yrs behind peak height growth. Peak bone growth occurred 1–3 yrs later in males. Over the 6-yr follow-up, all bone measurements “tracked”, but “shifting” across ranks also occurred, and baseline tertile ranking influenced bone growth. Females with early menarche had higher attained levels than females with late menarche at age 12–13 yrs. Conclusion Our findings confirm and expand previous studies on peak bone growth conducted in Caucasian cohorts, particularly sexually dimorphic and maturational effects. The significant “tracking” of bone measurements in this 6-yr follow-up study underscores the importance that osteoporosis prevention should begin in childhood and adolescence. Fengxiu Ouyang and Binyan Wang contributed equally to this article. Source(s) of support: This study is supported in part by grant R01 HD049059, R01 HL0864619 and R01 AR045651 from the National Institute of Health and by the Food Allergy Project.     

Requirement of MyD88 for macrophage-mediated islet xenograft rejection after adoptive transfer

BACKGROUND: Porcine antigen primed and CD4+ T-cell activated macrophages are able to migrate to and destroy porcine xenografts. However, the specific signaling mechanisms involved remain to be identified. METHODS: In this study macrophages which lack the universal toll-like receptor (TLR) adaptor MyD88 were used to investigate the role of TLR in the recognition and activation of macrophages in islet xenograft rejection. Macrophages were isolated from rejecting MyD88(-/-) and wild-type C57BL/6 mice that were recipients of neonatal porcine pancreatic cell cluster (NPCC) xenografts, and were transferred to NPCC recipient NOD-SCID mice. RESULTS: Both wild-type C57BL/6 and MyD88(-/-) mice rejected NPCC xenografts 8 and 10 days, respectively after transplantation, and the grafts were heavily infiltrated with CD4+ T cells and macrophages. However, graft infiltrating macrophages from rejecting MyD88(-/-) recipients demonstrated impaired up-regulation of TLR expression and impaired activation phenotype, when compared to those from rejecting C57BL/6 recipients. Transfer of NOD-SCID recipients with macrophages from rejecting C57BL/6 mice resulted in NPCC xenograft rejection along with massively infiltrated macrophages 8 days after transfer, whereas NPCC xenografts in NOD-SCID mice transferred with macrophages from rejecting MyD88(-/-) mice remained intact until the end of this study, 90 days after transfer, with insulin-positive islets and no infiltration by macrophages. CONCLUSION: This study demonstrates that deletion of MyD88 causes impaired macrophage activation after pig islet xenotransplantation. However, graft survival is not prolonged and xenografts are rejected rapidly by alternate mechanisms.     

供者NK细胞及其嵌合状态在异基因造血干细胞移植中的研究进展

目前,异基因造血干细胞移植(allo-HSCT)已广泛应用于造血系统疾病的治疗,但移植术后也存在一系列并发症。NK细胞的运用为改善allo-HSCT受者预后带来希望,供者来源NK细胞通过其细胞膜上的杀伤细胞免疫球蛋白样受体与其配体错配发挥同种异体反应,该过程具有保留移植物抗白血病和减少移植物抗宿主病双重效应。NK细胞是allo-HSCT后受者体内最早重建的免疫细胞群,因此移植后供、受者NK细胞嵌合状态评估对预测疾病预后及指导干预治疗具有重要意义。基于NK细胞嵌合状态的供者NK细胞输注免疫干预疗法可改善疾病预后,在血液系统疾病治疗中表现出良好的应用前景。本文就近年来供者NK细胞及其嵌合状态在allo-HSCT中的研究进展作一综述。