伽玛能谱仪分析226Ra的部分影响因素的研究

目的通过对γ能谱分析226Ra的部分影响因素进行有针对性的测量, 进一步优化γ能谱针对226Ra活度的分析方法, 以求得到更为精准的测量结果。方法利用实验室高纯锗γ能谱仪, 开展样品密封时间的跟踪测量、铅室本底波动影响测量, 分析方法与子体核素特征γ射线能峰选择等方面研究。结果样品密封12 d后, 226Ra-222Rn衰变系基本达到平衡。测量屏蔽铅室本底中222Rn昼夜波动明显且无明显规律, 向铅室内注入氮气的方式可降低或避免本底波动影响。针对31份密封23 d后测量的土壤样品, 采用效率曲线法分析的结果表明, 351.9 keV能峰计算的226Ra结果普遍高于609.3 keV能峰, 高出的比例范围为8.0%～20.7%;采用相对比较法分析的结果表明, 两能峰偏差的比例范围为-4.1%～10.3%。结论在样品密封后第12天进行测量时, 建议考虑由衰变系平衡因素引入约4%的不确定度。通过铅室内注入氮气避免本底波动时, 须注意铅室内腔体积与氮气注入流量的匹配关系。采用效率曲线法分析226Ra活度时, 214Bi(609.3 keV)能峰存在级联符合相加影响, 应避免选用;采用相对比较法...     

Beta 2-integrin and L-selectin are obligatory receptors in neutrophil aggregation [see comments]

We have recently found that antibodies to L-selectin, the homing receptor on neutrophils, are as effective as those to beta 2-integrin at blocking formyl peptide-stimulated aggregation. Therefore, we investigated the requirements for expression of L-selectin and beta 2- integrin on adjacent cells during aggregation. Fluorescence flow cytometry allowed characterization of aggregates on the basis of size and color, as well as antibody binding to these two adhesive molecules. Formyl peptide-stimulated aggregate formation was measured for individual populations fluorescently labeled red (LDS-751) or green (CD44-FITC), and interpopulation red-green cell conjugates. Blocking either the beta 2-integrin or L-selectin adhesive epitope with monoclonal antibody on individual cell populations resulted in an approximately 50% reduction in two-color aggregation as compared with that in unblocked samples. Shedding the L-selectin on a cell population by preincubation with complexes of lipopolysaccharide and its plasma membrane binding protein also decreased aggregation to a control population by approximately 50%. We examined the aggregation of neutrophils from patients genetically deficient in beta 2-integrin and clinically leukocyte adhesion deficient (LAD). LAD adhesion to normal neutrophils was dependent on the expression of L-selectin on LAD cells and beta 2-integrin on normal cells. Thus, the minimum requirement for adhesion between two mixed populations of neutrophils was that one population expressed the beta 2-integrin and the other expressed the L- selectin adhesive epitope.     

急性脑梗死后继发不安腿综合征20例分析及文献复习

目的 总结急性脑梗死后继发不安腿综合征(RLS)的临床、影像学特征.方法 回顾性分析2012年1月至2019年1月北京友谊医院诊治的20例急性脑梗死后继发RLS患者的临床表现、头颅磁共振(MRI)影像及治疗方案,总结其临床特征.结果 20例急性脑梗死后继发RLS患者的年龄为(62.65±9.40)岁;其中男性12例,女...     

联动成像模式对提高结直肠息肉检出率的有效性研究

目的 评估联动成像模式（linked color imaging,LCI)提高结直肠息肉检出率,尤其是腺瘤检出率的有效性。方法 回顾性分析2018年5月—2019年3月入院接受LASEREO系统结肠镜LCI模式或普通白光（white light imaging,WLI）模式检查的患者,比较两种模式下结肠镜检查整体息肉检出率、腺瘤检出率、扁平息肉检出率、小息肉(≤5 mm)检出率及右半结肠息肉检出率的差异。用国际照明委员会（Commission Internationale de L\"Eclairage,CIE）于1976年制定的L*a*b*颜色空间分析比较两种模式下腺瘤性息肉与周边黏膜的色差（ΔE）。结果 LCI组患者整体息肉检出率,尤其是腺瘤检出率高于WLI组,差异有统计学意义(45.53%比32.83%,P=0.038;53.65%比39.62%,P=0.009)。LCI组腺瘤性息肉与周边黏膜的色差（ΔE）明显高于WLI组,差异有统计学意义（27.24±8.67比15.28±6.68,P<0.001）,且LCI组扁平息肉、小息肉及右半结肠息肉检出率均高于WLI组,差异有统计学意义（61.98%比47.17%,P=0.005;60.94%比42.77%,P=0.001;45.83%比32.70%,P=0.012）。结论 LCI能有效提高结直肠息肉检出率,尤其是腺瘤检出率,值得临床推广应用。     

通过竞争性内源RNA调控网络筛查肝细胞癌预后相关分子

目的:通过构建肝细胞癌(hepatocellular carcinoma,HCC)的竞争性内源RNA(competing endogenous RNAs,ce RNA调控网络,寻找与HCC发生发展及预后相关的分子。方法:从TCGA数据库下载HCC转录组数据,通过\"Perl\"语言处理转化得到mRNA、lncRNA和miRNA的表达谱矩阵。通过\"Edge R\"包提取3种RNA的差异表达基因(differential expression genes,DGEs),其阈值为|log FC|>2.0且P<0.01。通过数据库比对得到差异lncRNA-差异miRNA、差异miRNA-差异m RNA关系对,导入至Cytoscape软件构建ceRNA调控网络图。整理3种DGEs相关的生存数据,通过\"Survival\"包及Kaplan-Meier Plotter分析软件进行生存分析,绘制DGEs的生存曲线,分析获取预后相关基因。结果:成功构建HCC的lncRNA相关ceRNA调控网络,通过该网络分析DGEs间的相互作用和调控关系,获取3条lncRNA-miRNA-mRNA调控关系对,其中1条调控通路(CCDC26-hsa-mir-141-EPHA2)符合ceRNA理论。预后分析显示,14个mRNA高表达组患者生存率低于低表达组,可作为HCC不良预后的生物标志物;1个lncRNA(TSPEAR-AS1)和2个mRNA(CPEB3和PROK2)低表达组患者生存率低于高表达组(P<0.05或P<0.01),可能是HCC的保护性基因。结论:通过HCC lncRNA相关的ceRNA调控网络筛查到高表达的14个mRNA可能为HCC不良预后相关分子,低表达的1个lncRNA和2个mRNA可能为HCC良好预后相关分子,研究结果为HCC治疗和预后测评提供了参考依据。     

视网膜中央静脉阻塞玻璃体积血合并原发性高血压的手术疗效

目的:分析视网膜中央静脉阻塞玻璃体积血合并原发性高血压的手术疗效.方法:回顾性分析2011-03/2015-03因玻璃体积血在我院行玻璃体切割的原发性高血压患者83例83眼,根据术中所见,其中有28眼玻璃体积血由视网膜中央静脉阻塞引起,术后随访9~36(平均22.4)mo.检查记录患者手术前后最佳矫正视力、术后并发症情况,并进行统计分析.结果:视网膜中央静脉阻塞玻璃体积血合并原发性高血压发生率为33.7%;术后最佳矫正视力3.3~4.5,术后最佳矫正视力提高24眼(86%),视力不变4眼(14%),无视力下降患者,手术前后视力相比差异有统计学意义(P<0.05);术后发生黄斑水肿5眼,发生率18%;所有患者术后均没有发生视网膜脱离及复发玻璃体积血.结论:手术治疗合并原发性高血压的视网膜中央静脉阻塞玻璃体积血疗效好,可减少并发症,提高视力.     

OCT检测POAG患者RNFL厚度的改变及视野缺损情况

目的:探讨OCT检测原发性开角型青光眼(POAG)患者视网膜神经纤维层厚度(RNFL)的改变及视野缺损情况.方法:回顾性病例系列研究.将POAG患者158例158眼作为POAG组,其中早期81眼,中期47眼,晚期30眼,选取同期体检无眼部相关疾病者50例50眼作为对照组.检测上方、下方、鼻侧、颞侧RNFL厚度及视野平均缺损值,POAG患者随诊3mo观察连续性变化.结果:POAG组随诊前及随诊3mo上方、下方、鼻侧、颞侧RNFL厚度均低于对照组,视野平均缺损值多于对照组,差异有统计学意义(P<0.05);早期POAG患者各部位RNFL厚度、视野平均缺损值与对照组比较差异无统计学意义(P>0.05),但各部位RNFL厚度高于中期、晚期POAG患者,视野平均缺损值少于中期、晚期POAG患者,差异有统计学意义(P<0.05);POAG组随诊前和随诊3mo各部位RNFL、视野平均缺损值比较差异无统计学意义(P>0.05).Pearson相关分析显示,上方、下方、鼻侧、颞侧RNFL厚度与视野平均缺损值均呈负相关关系(r=-0.719、-0.615、-0.681、-0.518,均P<0.05).结论:OCT可监测POAG患者RNFL厚度变化,且与视野平均缺损呈负相关关系,可用于POAG早期诊断.     

Postamputation neuromas and other symptomatic stump abnormalities: detection with CT

One of the potentially troublesome sequelae of limb amputations is the development of stump neuromas at the severed ends of major nerves. The ability to define them and to distinguish them from other causes of stump pain is of considerable clinical significance. Computed tomography was performed on ten lower limb amputees with stump pain. Five patients had neuromas that were manifest as focal or generalized alteration in the caliber, size, or contour of the nerve trunk in the affected stump. The remaining five patients each had an abnormality detected; these abnormalities included heterotopic bone formation, popliteal artery aneurysm, lipoma, scar tissue, and abscess in the contralateral limb.     

Targeted Disruption of the CXCL12/CXCR4 Axis Inhibits Osteolysis in a Murine Model of Myeloma‐Associated Bone Loss

The plasma cell (PC) malignancy, multiple myeloma (MM), is unique among hematological malignancies in its capacity to cause osteoclast (OC)‐mediated skeletal destruction. We have previously shown that elevated plasma levels of PC‐derived CXCL12 are associated with presence of X‐ray detectable osteolytic lesions in MM patients. To further investigate this relationship, plasma levels of CXCL12 and βCrossLaps, a marker of bone loss, were measured. A strong correlation between levels of CXCL12 and OC‐mediated bone resorption was identified. To confirm the OC‐activating potential of MM PC‐derived CXCL12 in vivo, we established a model of MM‐mediated focal osteolysis, wherein MM PC lines, such as RPMI‐8226, were injected into the tibias of nude mice. Implanting RPMI‐8226 gave rise to osteolytic lesions proximal to the tumor, resulting in a 5% decrease in bone volume (BV) compared with vehicle control. Importantly, bone loss was significantly inhibited with systemic administration of the CXCL12/CXCR4 antagonist T140. Furthermore, implanting CXCL12‐overexpressing RPMI‐8226 cells resulted in a 13% decrease in BV and was associated with increased OC recruitment proximal to the tumor, increased serum matrix metalloproteinase activity, and increased levels of collagen I degradation products. These findings confirm our hypothesis that MM PC‐derived CXCL12 stimulates the recruitment and activity of OC, thereby contributing to the formation of MM osteolytic lesions.