Automatic algorithm for correcting motion artifacts in time-resolved two-dimensional magnetic resonance angiography using convex projections.

Time-resolved contrast enhanced magnetic resonance angiography (MRA) may suffer from involuntary patient motion. It is noted that while MR signal change associated with motion is large in magnitude and has smooth phase variation in k-phase, signal change associated with vascular enhancement is small in magnitude and has rapid phase variation in k-space. Based upon this observation, a novel projection onto convex sets (POCS) algorithm is developed as an automatic iterative method to remove motion artifacts. The presented POCS algorithm consists of high-pass phase filtering and convex projections in both k-space and image space. Without input of detailed motion knowledge, motion effects are filtered out, while vasculature information is preserved. The proposed method can be effective for a large class of nonrigid motions, including through-plane motion. The algorithm is stable and converges quickly, usually within five iterations. A double-blind evaluation on a set of clinical MRA cases shows that a completely unsupervised version of the algorithm produces significantly better rank scores (P=0.038) when compared to angiograms produced manually by an experienced radiologist.     

重症急性胰腺炎早期治疗的探讨及分析

目的 探讨重症急性胰腺炎（SAP）早期治疗体会及外科手术治疗时机和手术方式的选择。方法 对比分析1989—1995年以早期手术为主的36例SAP（A组）与1996—2003年7年中非手术治疗为主的44例SAP（B组）的治愈率和死亡率。结果 B组的死亡率明显低于A组，A组的治愈率低于B组。结论 SAP早期的急性炎症反应期，手术只能加重对机体的打击，加重SAP全身炎症反应，增加手术死亡率。故SAP早期治疗应以非手术疗法为主。当内科治疗无效，手术治疗是唯一的选择，而手术时机的掌握和手术方式的选择更为重要，直接影响手术结果。     

门脉高压性胃病患者的胃壁血气变化

作者观测了４３例门脉高压症患者股动脉血ＰＯ２、胃网膜有动静脉胃壁支血ＰＯ２、胃壁支静脉及肘静脉血ｐＨ、ＨＣＯ３－和胃网膜右静脉压力，其中２３例并有非出血期门脉高压性胃病。结果表明：①门脉高压症患者的股动脉血ＰＯ２低于对照组；②门脉高压症患者胃网膜右动静脉胃壁支血氧分压差低于对照组，胃网膜右静脉压力高于对照组，胃壁支静脉血ｐＨ和ＨＣＯ３－低于对照组和同组肘静脉血。并有门脉高压性胃病者这些变化更为显著。提示门脉高压性胃病的发病机制在于门脉系压力增高、胃粘膜下动静脉短路开放、胃粘膜缺血缺氧和胃壁局部酸中毒。     

放疗化疗联合治疗局部晚期非小细胞肺癌43例

目的 探讨以顺铂为主的化疗方案加放疗对局部晚期非小细胞肺癌的疗效。方法 86例局部晚期非小细胞肺癌患随机分为治疗组及对照组各43例，放疗方案以CAP、EP、MVP或MOP，每人至少化疗两个周期，化疗后10～14天放射治疗，放疗采用^60Co外照射。结果 治疗组有效率83．7％，中位生存期14．5个月，对照组有效率67．4％，中位生存期10个月，两组不良反应为骨髓抑制、胃肠道反应。结论 以顺铂为主的化疗方案加放疗治疗局部晚期非小细胞肺癌的疗效较高，可提高肿瘤的局部控制率和延长生存期。     

Social and psychological factors associated with adolescents'' self-acceptance of occlusal condition

Studies using plaster models of teeth and photographs simulating the full range of occlusal conditions have found high agreement between measures of adolescent social acceptability of these conditions and perceived need for orthodontic treatment. This study examined the association between adolescents' acceptability of their own occlusal condition, severity of malocclusion, and likelihood of undergoing orthodontic treatment. The factors predicting the acceptability of occlusal condition of 13-yr-olds, as assessed by the SASOC scale, were measurements of acceptability of general physical appearance, and the severity of occlusal condition. Variability in SASOC scores appeared to be independent of gender, socioeconomic status, and ethnicity. Gender, and severity of occlusal condition were important differences between subjects who had received, planned, or were undergoing orthodontic treatment, and those who had not. Neither SASOC scores nor perceived need for treatment accounted for a significant proportion of the variance between these groups. Although adolescents seeking orthodontic treatment had a greater severity of malocclusion than those not, little difference was observed between these groups in acceptance of occlusal condition.     

Prefrontal cerebral activity during a simple “rock, paper, scissors” task measured by the noninvasive near-infrared spectroscopy method

We conducted a noninvasive near-infrared spectroscopy (NIRS) study using the game of rock, paper, scissors (RPS) as a simple neurocognitive task for the prefrontal cortex (PFC) in 15 healthy volunteers. We employed an opposite “to lose” RPS task coupled with a normal “to win” RPS task, since the former requires inhibition of behavior, one of the most important functions of the prefrontal cortex. During the NIRS examination, subjects had to present one of the three RPS hands in response to hands displayed randomly on a computer screen every 1.5 s, and were required to show hands that lose to the computer, or that beat the computer. We measured the relative concentrations of oxyhemoglobin (oxy-Hb) using the prefrontal probes of the NIRS system during the tasks. The increases in oxy-Hb during the “to win” RPS task were small, but were quite large and laterally dominant during the “to lose” RPS task. The difference between the two tasks might have been due to the participants’ cognitive conflict with losing on the RPS. We conclude that losing is better than winning on the RPS as a sensitive indicator in the NIRS examination of PFC.     

七氟醚和缺氧预适应诱导乳鼠心肌细胞HSP70表达的改变

目的 :探讨七氟醚预适应和缺氧预适应对乳鼠心肌细胞热休克蛋白 70表达的影响。方法 :第 2代培养心肌细胞随机分为正常对照组 (C组 )、缺氧 /复氧组 (A/R组 )、缺氧预适应组 (IP组 )和七氟醚预适应组 (S组 ) ,每组均缺氧 2h ,复氧 48h。分别取复氧 0 ,1,12 ,2 4,36和 48h的细胞 ,用免疫组化染色检测HSP70 表达并进行图象分析。结果 :在各个时间点 ,S组和IP组间的HSP70 表达均显著高于A/R组和C组 (P <0 .0 1) ,A/R组的HSP70 表达略高于C组 ,S组和IP组间的HSP70 表达差异无显著性 (P >0 .0 5 )。随着复氧时间的延长 ,S组和IP组间的HSP70 表达从 1h开始增加 ,2 4h表达最强 ,与 1h相比差异具有显著性 (P <0 .0 5 )。结论 :七氟醚预处理和缺氧预处理均可诱导乳鼠心肌细胞HSP70 在延迟相呈高表达 ,提示HSP70 参与了七氟醚预适应和缺氧预适应的延迟保护相。     

消炎痛及乙胺嗪对动物急性缺氧性肺、脑血管反应的影响

研究消炎痛及乙胺嗪对家兔肺、脑血管和大鼠脑微动脉缺氧反应的影响。发现吸入10％氧使家兔肺血管阻力(PVR)增加,脑血管阻力(CVR)降低,大鼠脑微动脉扩张。用消炎痛明显增强家兔缺氧性肺、脑血管反应。△PVR％由用药前26.6±16.7％增至44.2±7.7％;△CVR％则由一12.9±4.5％减至-30.7±4.7％;大鼠微动脉直径增大率(△D％)由用药前28.2±2.0％增至41.3±5.8％;用乙胺嗪则使缺氧时△PVR％由 84.6±18.1％降至 23.8±8.5％;△CVR％由-16.7±4.5％变为 6.9±2.8％;△D％由 29.7±5.8％减至 25.6±5.0％。结果表明前列腺素在缺氧性肺血管收缩反应及脑血管扩张反应中起调节作用,而白三烯则在缺氧性肺血管收缩反应中起介导作用。     

胎肌条件培养液对白血病细胞的体外效应

以髓系(HL-60)与淋系(Molt-4)细胞为观察对象,用细胞计数、细胞集落培养、台酚蓝拒染及溴化二甲噻唑二苯四唑试验为观察手段,研究胎肌条件培养液(FMCM)对白血病细胞的影响.实验标本分为4组:①对照组.②20%FMCM处理组.③阿糖胞苷(Ara-C,1×10~(-7)M/L)处理组.④混合处理组(经FMCM与Ara-C二者的处理).发现:①FMCM对两个细胞株均无明显的直接作用.②当HL-60细胞经FMCM预处理或在用Ara-C处理同时加入FMCM,Ara-C对其抑制作用可为FMCM加强,已受Ara-C抑制的HL-60细胞则无此现象.③Ara-C对Molt-4的抑制作用不受FMCM的影响.由此而初步认为:①FMCM对白血病细胞似无明显直接作用.②某些(非全部)白血病细胞对Ara-C的敏感性可为FMCM加强.③在己受抑制的细胞中不呈现这种致敏现象.①提示FMCM有可能用于白血病临床治疗.