Four-Dimensional Computerized Tomography （4D-CT） Reconstruction Based on the Similarity Measure of Spatial Adjacent Images

Objective：To investigate the feasibility of a 4D-CT reconstruction method based on the similarity principle of spatial adjacent images and mutual information measure. Methods：A motor driven sinusoidal motion platform made in house was used to create one-dimensional periodical motion that was along the longitudinal axis of the CT couch. The amplitude of sinusoidal motion was set to an amplitude of ±1 cm. The period of the motion was adjustable and set to 3.5 s. Phantom objects of two eggs were placed in a Styrofoam block, which in turn were placed on the motion platform. These objects were used to simulate volumes of interest Undergoing ideal periodic motion. CT data of static phantom were acquired using a multi-slice general electric （GE） LightSpeed 16-slice CT scanner in an axial mode. And the CT data of periodical motion phantom were acquired in an axial and cine-mode scan. A software program was developed by using VC ＋ ＋ and VTK software tools to resort the CT data and reconstruct the 4D-CT. Then all of the CT data with same phase were sorted by the program into the same series based on the similarity principle of spatial adjacent images and mutual information measure among them, and 3D reconstruction of different phase CT data were completed by using the software. Results：All of the CT data were sorted accurately into different series based on the similarity principle of spatial adjacent images and mutual information measures among them. Compared with the unsorted CT data, the motion artifacts in the 3 D reconstruction of sorted CT data were re- duced significantly, and all of the sorted CT series result in a 4D-CT that reflected the characteristic of the periodical motion phantom. Conclusion：Time-resolved 4D-CT reconstruction can be implemented with any general multi-slice CT scanners based on the similarity principle of spatial adjacent images and mutual information measure. The process of the 4D-CT data acquisition and reconstruction were not restricted to the hardware or software of the C     

rhGM-CSF作为成人乙肝疫苗无(弱)应答者免疫佐剂初探

Objective To investigate the effect of recombinant human granulocyte macrophage colony stimulating factor (rhGM-CSF) as adjuvant on immune response in adults of non-and hyporesponders to hepatitis B vaccine. Methods Those who were once immunized with recombined yeast gene hepatitis B vaccine more than one standard scheme in two years and negative for hepatitis B markers were randomly sorted as group A and group B. 33 adults of group A were given hepatitis B vaccine 10 μg each time. The immune procedure was O, 1 and 6month. 34 adults of group B were given rhGM-CSF 300 μg for the first day, then 10 μg each time for routine immune. The blood samples were collected before the first injection and in 1, 2 and 8 months (T1, T2, TS)following the first injection to test Anti-HBs. Results Anti-HBs positive conversion rates of group A and B at T8 was 39.39% and 64.71% respectively(P=0.038). Anti-HBs levels of group B at TI, T2, T8 were(113.85±198.56) mIU/ml, (312.40±349.44) mIU/ml, (427.74±411. 58) mIU/ml (P=0.001). There was significant difference between group A and B in T8 Anti-HBs levels(P=0.010). Conclusion Better immune response was found in the group of rhGM-CSF with hepatitis B vaccine. So rhGM-CSF can induce the immune respond to hepatitis B vaccine.     

A COMPARISON OF ATRACURIUM AND ALCURONIUM DURING HALOTHANE ANAESTHESIA BY MEASUREMENT OF THE TRAIN-OF-FOUR RESPONSE OF THE ADDUCTOR POLLICIS MUSCLE AND CLINICAL OBSERVATION

Atracurium and alcuronium have been compared during halothaneanaesthesia, by measurement of the mechanical response of theadductor pollicis muscles to train-of-four stimulation and byclinical observation. Atracurium appeared significantly shorter-actingthan alcuronium. However, results suggested that the actionof alcuronium may not be of "medium duration ". A comparisonof three indices of muscle twitch response to the train-of-fournerve stimulation, seemed to indicate that the D'/D ratio gavethe best overall index of neuromuscular blockade in this study.     

舌癌术前化疗PCNA、bcl-2、Bax基因表达及临床意义

目的 :通过舌癌术前化疗增殖细胞核抗原 (PCNA )和细胞凋亡相关基因 bcl- 2、Bax表达的研究 ,探讨舌癌的化疗作用机制。 方法 :对舌乳头状瘤、舌癌和舌癌术前化疗标本共 34例 ,采用免疫组织化学染色技术——酶标链亲和素生物素法 (L SAB)染色并进行光镜下观察。结果:PCNA在舌癌中的表达最强 ,在舌癌术前化疗中的表达明显减弱 (P <0 .0 5 ) ,其与舌乳头状瘤表达相似 (P >0 .0 5 )。 bcl- 2在舌癌术前化疗及舌乳头状瘤中低表达(P >0 .0 5 ) ,舌癌中表达明显增强 (P <0 .0 5 )。Bax在舌癌组和乳头状瘤组中表达有明显差异 (P <0 .0 5 )。结论 :化疗药物抑制肿瘤生长的机制可能与抑制肿瘤细胞增殖和诱导肿瘤细胞程序性死亡有关 ,提示舌癌术前化疗对肿瘤的预后有重要意义。     

慢性乙型肝炎患者肝组织FasL表达与血清可溶性FasL水平的关系

目的：探讨慢性乙型肝炎患者肝组织中FasL表达与血清可溶性FasL水平的关系。方法：用免疫组化方法检测60例慢性乙型肝炎患者肝穿组织FasL的表达,同时用酶联免疫吸附试验检测血清可溶性FasL。结果：重度慢性乙型肝炎患者血清中sFasL水平＞中度＞轻度,各组间差异有显著意义（P＜0．01）;慢性乙型肝炎患者肝组织FasL表达的程度和血清sFasL水平与肝组织病变的活动性一致。结论：（1）肝组织炎症程度加重,肝组织FasL抗原的表达增强,同时血清中sFasL水平升高;（2）Fas介导的肝细胞凋亡在慢性乙型肝炎的发病机制中起重要作用,抑制肝细胞Fas表达有助于减轻肝细胞损伤程度。     

口腔固定修复学临床前期实习中的问题与对策

本文总结了北京大学口腔医学院3届八年制口腔医学专业学生口腔固定修复学临床前期实习教学的经验,针对实习中出现的典型问题进行了分析,采取了相应的对策和方法,取得了良好的效果.     

组织工程支架材材料的研究进展

研究开发具有良好性能的组织工程支架材料是组织工程研究的热点之一.由于组织工程支架材料的研究面较广,文章仅从研究热点中的不同材料间的复合、致孔剂的应用、生长因子的引入三个方面,对组织工程材料的研究状况做一综述,为广大从事组织工程研究的同仁们提供参考.     

阴道炎患者HPV6/11-DNA定量分析

目的：了解女性阴道炎患者人乳头瘤病毒6／11型（HPV6／11）的感染情况。方法：荧光定量聚合酶链反应（FQ－PCR）技术检测258例门诊患者阴道分泌物中HPV6／11的病毒拷贝数。结果：共检出HPV6／11阳性者94例,阳性率36．43％,拷贝数在10^5以上者78例,占阳性者中82．98％,40岁以上年龄组阳性率高且病毒复制量均在10^5以上。结论：（1）中老年阴道炎患者就诊晚,感染重。（2）FQ－PCR检测HPV敏感,快速,准确,特别是其定量特点对临床很有意义。     

胆必清对内毒素诱导的大鼠腹腔巨噬细胞内游离钙浓度的影响

目的：探讨中药胆必清对内毒素诱导的大鼠腹腔巨噬细胞游离钙浓度的影响。方法：制备大鼠腹腔巨噬细胞并在体外进行孵育,使用荧光探针用荧光法测定钙浓度。巨噬细胞随机分为正常对照组,内毒素LPS组,小、中和大剂量中药组。结果：LPS能诱导巨噬细胞[Ca2^ ]i的升高。加入胆必清后,[Ca2^ ]i可有不同程度的降低。结论：胆必清能抑制LPS诱导的大鼠腹腔巨噬细胞内的[Ca2^ ]i升高,提示该药具有抗炎和免疫调节作用。     

McAb共刺激PBLs淋巴细胞在培养体系中的状态及超微结构的 …

通过用抗ＣＤ３,ＣＤ２８＋ＣＤ８０ ＭｃＡｂ激活健康人的ＰＢＬｓ,并以ＰＨＡ,ＩＬ－２,ＰＢＬｓ为对照组;对各组不同时间段的淋巴细胞超微结构进行观察。结果提示：ＣＤ３及ＣＤ２８＋ＣＤ８０刺激淋巴细胞增殖外,也能使淋巴细胞活化,细胞表现为胞体增大,细胞器增多,具有粗大的绒毛和突出伪足,并可见单核细胞吞噬活跃。