钙离子内流参与利妥昔单抗增强辐射诱导的Raji细胞凋亡

钙离子是细胞生命活动的重要信使,刺激B细胞受体可诱导细胞内钙库的损耗,导致质膜上调控钙库的钙通道激活。已经发现,随着游离钙离子稳态被打破以及CD20与其单克隆抗体（利妥昔单抗）偶联,可导致细胞凋亡。细胞转染CD20后,可增加钙离子通过质膜进入细胞内,证明CD20具有调节细胞周期进程和作为钙离子通道平衡细胞内外钙浓度的功能。在Ramos B细胞中,src家族蛋白酪氨酸激酶的CD20调节刺激提高了细胞内钙离子浓度,并且诱导了Caspase 3的活性。除此之外,利妥昔单抗诱导的CD20和脂筏的高亲和性是钙进入细胞和激活下游凋亡信号的先决条件,与B细胞抗原受体的表达密切相关。在淋巴瘤细胞系中,利妥昔单抗联合辐射能显著提高辐射诱导细胞凋亡,利妥昔单抗通过改变细胞程序性死亡相关蛋白的表达、提高细胞内ROS水平、调节细胞周期等提高淋巴瘤细胞的辐射敏感性。然而,钙离子是否参与辐射和CD20靶向诱导细胞死亡尚不明确。闵凤玲等的“Influx of extracellular calcium participates in rituximab-enhanced ionizing radiation-induced apoptosis in Raji cells”一文,研究了利妥昔单抗和X射线照射后,淋巴瘤细胞内钙离子水平变化与DNA双链断裂和辐射诱导细胞死亡的关系,探讨了利妥昔单抗在辐射诱导细胞死亡中的作用机制。     

利妥昔单抗免疫化疗联合自体外周血干细胞移植治疗CD20+B细胞性非霍奇金淋巴瘤的临床研究

目的 分析和探讨利妥昔单抗联合自体外周血造血干细胞移植(APBSCT)序贯维持治疗对CD20+B细胞非霍奇金淋巴瘤(NHL)的疗效.方法 搜集2005年1月—2011年1月诊断为侵袭性和(或)难治复发性CD20+B细胞NHL并接受APBSCT治疗的60例患者的临床资料.分为2组:治疗组(n=25),APBSCT前应用利妥昔单抗3～4次,采集自体干细胞前1d加用利妥昔单抗治疗1次(375mg/m2)体内净化干细胞,移植后每3～6个月应用利妥昔单抗联合白细胞介素-2(100万U/次,缓慢静滴)维持治疗3～4次;对照组35例,除未用利妥昔单抗以外,其他处理与治疗组相同.结果 利妥昔单抗在移植前、干细胞采集前及移植后巩固治疗中均未发现明显不良反应.治疗组和对照组采集单个核细胞数分别为(8.2±2.9)×108/kg和(8.4±3.9)×108/kg(P=0.822),CD34+细胞数分别为(12.3±12.7)×106/kg和(13.2±13.9)×106/kg(P=0.799).治疗组均顺利完成造血重建,对照组3例造血重建失败.两组中性粒细胞恢复时间和血小板恢复时间差异无统计学意义.移植后所有病例均达完全缓解(CR),中位随访22(2 ～ 81)个月,治疗组2例复发,对照组6例复发.治疗组3年总体生存率有高于对照组的趋势(91.6％ vs 69.5％,P=0.060).结论 侵袭性和(或)难治复发性CD20+B细胞NHL患者APBSCT前后应用利妥昔单抗不影响造血干细胞的采集和造血重建,且有望提高治疗效果、改善总体生存.     

低剂量利妥昔单抗治疗15例温抗体型自身免疫性溶血性贫血的疗效观察

目的观察低剂量利妥昔单抗联合地塞米松治疗15例温抗体型自身免疫性溶血性贫血的疗效及安全性。方法对2007年1月—2012年10月我院收治的15例温抗体型自身免疫性溶血性贫血(WAIHA)患者(其中1例为Evans综合征)采用以下方案进行治疗:在第1、8、15、22天给予利妥昔单抗100 mg/次;给予利妥昔单抗前5 d开始给予地塞米松20mg/d,共5次。结果总有效率为86.7%(13/15),中位起效时间为2个月(四分位数间距1.5个月),中位随访时间为12个月(四分位数间距4个月)。复发患者再次强化治疗仍有效。部分缓解患者抗体效价降低。1例Evans综合征患者未出现出血倾向,血小板持续维持在(90~130)×10~9/L。所有患者对该治疗方案耐受性良好,不良事件发生率低。结论低剂量利妥昔单抗联合地塞米松治疗WAIHA安全、高效。     

小剂量利妥昔单抗治疗难治及复发性温抗体型AIHA临床研究

目的探讨小剂量利妥昔单抗治疗难治及复发温抗体型自身免疫性溶血性贫血(AIHA)的有效性和安全性。方法研究纳入11例难治及复发温抗体型自身免疫性溶血性贫血患者,给予利妥昔单抗100 mg静脉滴注,每周1次,连用4周;通过动态观察血红蛋白、网织红细胞、总胆红素、间接胆红素、乳酸脱氢酶及直接抗人球蛋白试验(DAT)变化评价疗效,采用流式细胞术检测治疗前后CD3~+、CDl9~+CD20~+淋巴细胞数,免疫比浊法定量检测治疗前后血清免疫球蛋白(IgG、IgM、IgA)水平。结果治疗后,11例患者中5例(45.45%)完全缓解,3例(27.27%)部分缓解,而3例(27.28%)无效,总有效率为72.72%。小剂量利妥昔单抗治疗前后血清免疫球蛋白及CD3~+淋巴细胞数无明显变化(P>0.05),但CDl9~+CD20~+淋巴细胞数较治疗前明显下降(P<0.01),并达到清除水平。2例患者输注小剂量利妥昔单抗过程中发生输液反应,1例随访期间发生细菌性肺炎,经抗感染后治愈。结论小剂量利妥昔单抗治疗难治及复发温抗体型自身免疫性溶血性贫血安全、有效的,但其最佳用药方案尚需更多临床患者观察加以验证。     

新型抗uPAR人源化抗体的表达和活性检测

目的制备抗尿激酶型纤溶酶原激活物受体（uPAR）人源化抗体并初步检测它们与抗原的亲和能力。方法通过计算机辅助设计的结果,合成新型抗uPAR抗体的轻链和重链可变区基因序列,通过重叠PCR方法,拼接成完整的轻链和重链基因并克隆入pIRES双向表达载体。瞬时转染293T细胞,收取细胞上清,rProtein A亲和层析法纯化目的抗体,并进行SDS-PAGE和免疫印迹鉴定,采用Biacore3000技术检测抗体与抗原的结合能力。结果成功构建5种表达载体S1~S5,纯化的抗体在还原SDS-PAGE中表现为相对分子质量约为25×103和55×103两条带;免疫印迹分析表明,该人源化抗体可与羊抗人IgG特异性结合。Biacore3000实验结果表明,S2、S4和S5抗体与抗原具有良好的亲和活性,且亲和活性分别为1.74×10-8,1.49×10-8和1.05×10-8mol/L。结论成功构建并表达了5种抗uPAR人源化抗体,其中S2、S4和S5具有良好的抗原结合能力。     

99Tc m-利妥昔单抗SPECT/CT乳腺癌前哨淋巴结显像的临床评价

目的 探讨99Tcm-利妥昔单抗（99Tcm- Rituximab）SPECT/CT对乳腺癌前哨淋巴结（SLN）的诊断效能。 方法 回顾性分析2019年7月至2020年7月于海南省肿瘤医院经组织病理学检查证实的22例女性乳腺癌患者的临床资料,患者年龄37~73岁（中位年龄50.5岁）。所有患者术前均行99Tcm-利妥昔单抗SPECT/CT显像,分析图像并统计SLN的数量。显像后1~2 h进行手术,术中采用便携式γ探测器探测SLN,以术中检出的SLN数量为“金标准”,评估99Tcm-利妥昔单抗SPECT/CT的诊断效能。 结果 99Tcm-利妥昔单抗SPECT/CT显像共检出SLN 67枚,以1~3 枚者居多（68%,15/22）,术中γ探测器共检出SLN 81枚,以2~4 枚者居多（73%,16/22）。以患者为单位,99Tcm-利妥昔单抗显像的灵敏度为100%（22/22）、总符合率为100%（22/22）;以淋巴结为单位,灵敏度为83%（67/81）、阳性预测值为100%（67/67）、总符合率为83%（67/81）。 结论 99Tcm-利妥昔单抗 SPECT/CT对乳腺癌SLN的诊断灵敏度及符合率高,具有较好的临床应用性。      

利妥昔单抗对重症肌无力的治疗作用

利妥昔单抗（fituximab,RTX,美罗华）是针对B细胞表面CD20抗原分子而通过基因重组技术生产的嵌合型单克隆抗体,1997年11月获FDA批准的第一个用于治疗人类恶性、顽固性滤泡低分化型非霍奇金淋巴瘤的单抗产品。随着研究的不断深入,RTX在一些自身免疫性疾病中得到应用,     

抗A型肉毒毒素鼠源性单克隆抗体的制备和鉴定

目的：制备与鉴定抗A型肉毒神经毒素重链C端（ heavy chain of botulinum neurotoxin serotype A, BoNT／AHc）特异性鼠单克隆抗体。方法通过纯化BoNT／AHc抗原、免疫BALB／c小鼠并建立杂交瘤细胞以制备鼠单抗,用ELISA、Western印迹实验和抗体分型试剂盒进行分析鉴定,并通过ELISA检测鼠单抗与BoNT／AHc突变体结合,初步鉴定其在BoNT／AHc的结合表位。结果得到纯度较高的BoNT／AHc抗原,制备了4株特异性鼠单抗1A4、3H3、3H7、5H8。间接ELISA结果显示,单抗细胞上清效价均＞3．0×103;Western印迹检测结果显示,单抗均能与BoNT／AHc特异性结合;抗体亚型鉴定结果为1A4、3H7属于IgG1（Κ）,3H3属于IgM（Κ）,而5H8属于IgG2b （Κ）;叠加ELISA实验表明,4株单抗抗原识别表位相近;用ELISA检测单抗与BoNT／AHc突变体结合实验结果初步确定了4株单抗与BoNT／AHc的结合表位。结论对抗A型肉毒毒素鼠源性抗体完成了制备和鉴定,为肉毒毒素中和抗体的开发与阐明中和抗体的表位奠定了基础。     

西妥昔单抗对人肝癌细胞HepG2的体外效应

目的探讨西妥昔单抗（爱必妥,cetuximab,Erbitux）对人肝癌细胞HepG2的体外效应。方法流式细胞术检测HepG2细胞表面表皮生长因子受体（EGFR）的表达。细胞划痕及Transwell实验检测西妥昔单抗对HepG2细胞迁移能力的影响。Western印迹检测西妥昔单抗对HepG2细胞EGFR、AKT及ERK表达及活化的影响。碘化丙啶（propidium lodide,PI）染色检测西妥昔单抗对细胞周期的影响。结果流式细胞分析结果显示,HepG2细胞表面存在较高水平的EGFR表达;细胞划痕及Transwell结果表明,西妥昔单抗对HepG2细胞迁移能力具有明显的抑制效应;Western印迹结果证明西妥昔单抗能显著降低HepG2细胞内EGFR、AKT及ERK的磷酸化水平;细胞周期分析显示西妥昔单抗作用24 h剂量依赖性影响HepG2细胞周期进程,并将其阻抑在G0/G1期。结论西妥昔单抗可以抑制高表达EGFR的肝癌细胞系HepG2胞内关键信号蛋白的活化,阻滞其细胞周期,抑制肝癌细胞的迁移能力。     

467例乳腺癌患者^99Tc^m-利妥昔单抗前哨淋巴结显像结果分析

目的探讨应用前哨淋巴结（SLN）显像剂^99Tc^m-利妥昔单克隆抗体（简称利妥昔单抗,美罗华）进行乳腺癌SLN活组织检查（SLNB）的可行性与可靠性,以及不同因素对SLN显像及SLNB的影响。方法467例乳腺癌患者在超声引导下于乳腺肿块周围及肿块表面皮下注射^99Tc^m-利妥昔单抗后行SLN显像。术中凭显像结果行腋窝区SLNB,将切取的SLN行常规HE染色及免疫组织化学检查。结果SLN显像成功率99．14％（463／467）,共显示SLN837枚,人均1．79枚（837／467）,分布于腋窝区、内乳区、乳腺组织内及锁骨下区。腋窝区SLNB成功率99．57％（465／467）,手术共探测到SLN1182枚,人均2．53枚。病理检查发现腋窝SLN有转移者131例,转移SLN194枚。其中1例单纯由免疫组织化学法发现微小转移灶。患者年龄、显像时间、病理类型、临床分期、显像前是否行乳腺肿块手术切取活组织检查对SLN显影率、SLNB成功率及SLN转移率均无影响。不同病理类型及临床分期的患者其SLN转移率的差异有统计学意义（χ^2=14．134,29．184,P均〈0．05）。结论应用^99Tc^m-利妥昔单抗行乳腺癌SLN显像及SLNB成功率较高,具有较好的临床应用前景。     

Stress MR imaging for evaluation of popliteal artery entrapment

The popliteal artery entrapment (PAE) syndrome has been recognized as a cause of arterial occlusion in young people. It is the result of an anomaly of the relationship between the popliteal artery and the gastrocnemius muscle. Eight young healthy volunteers (16 legs) and six patients (10 legs) with suspected PAE underwent magnetic resonance (MR) imaging. Gradient-echo images were obtained in axial planes with the leg at rest and during active plantar flexion against resistance. Imaging at rest allowed identification of PAE signs in only one leg, which had an anomalous medial course of the popliteal artery. In the other cases, only the stress technique was able to show signal loss in the popliteal artery due to muscular compression (two legs) or the presence of accessory muscle slip around the vessel (two legs), as confirmed at surgery. MR imaging is therefore a useful technique for the diagnosis of PAE because of its capability of combining information obtainable with other modalities.     

MR imaging of muscle and tender points in fibromyalgia

Fibromyalgia is a syndrome manifested by chronic, diffuse muscu-loskeletal aching and soreness, palpable muscle tender points, and other symptoms. Standardized clinical diagnostic criteria have recently been developed. Skeletal muscle has been postulated as the end organ in this disease. Biochemical, histologic, electromyographic, and conventional radiographic studies have demonstrated no definitive abnormality. This study sought to establish whether magnetic resonance (MR) imaging could demonstrate any abnormality in these patients. Eighteen patients were entered in the study, 14 of whom were able to complete their examinations. T1 -weighted, T2-weighted, gradient-echo, and STIR (short-tau inversion-recovery) sequences were performed in all patients, with selected patients examined with T1weighted, gadopentetate dimeglu-mine-enhanced sequences. The trapezius and suboccipital regions were imaged in patients who, clinically, had active fibro-myalgia. No abnormalities could be detected. The authors conclude that the conventional MR imaging used in this study was unable to depict any primary skeletal muscle abnormality in fibromyalgia.     

Controversies in cervical spine imaging in trauma patients

No area of emergency radiology has generated as much discussion in recent years as the subject of cervical spine imaging for trauma patients. This review will be in three parts. The first will examine the indications for cervical imaging and will focus on those factors that make patients at high risk or low risk for cervical injury. The second part will discuss the merits of radiography and computed tomography as the main screening diagnostic examination. In addition to the roles of each modality in the evaluation process, such factors as efficacy of diagnosis, time (duration) of study, and cost will be discussed. Finally, the third part will explore the methods currently employed to clear the cervical spine in comatose patients.Presented at the Annual Meeting of the American Society of Emergency Radiology, Las Vegas, Nevada, 22–25 October, 2003     

Uterine contractions: Possible diagnostic pitfall at MR imaging

A total of 206 nongravid patients with various gynecologic problems underwent pelvic magnetic resonance (MR) examinations that included both sagittal T2-weighted and contrast agent–enhanced T1-weighted images. MR images were retrospectively reviewed to identify changes in endometrial configuration on serial images obtained during the same MR examination. In 20 MR examinations (all in women of reproductive age), endometrial distortion due to myometrial bulging was noted on T2-weighted or contrast-enhanced T1-weighted images. It was absent on other MR images obtained at different times. Myometrial bulging exhibited low signal intensity in 18 examinations. The finding resembled adenomyosis or leiomyoma on T2-weighted or contrast-enhanced T1-weighted images. These results evidence the presence of transient myometrial bulging and transient low-intensity myometrium in the nongravid uterus. This phenomenon is thought to represent uterine contraction. Clinicians should be aware of the potential presence of transient low-signal-intensity myometrial bulging that could present diagnostic problems in the normal uterus.     

Brodie Abscess: MR imaging appearance in 10 patients

The magnetic resonance (MR) imaging features of Brodie abscess have not yet been fully evaluated. Ten patients with Brodie abscess, eight of long bone and two of vertebra, were studied with MR imaging. Long bone abscess had a characteristic “target” appearance with four layers: (a) a center with low signal intensity on T1-weighted images and high signal intensity on T2-weighted and STIR (short-inversion-time inversion recovery) images, (b) an inner ring isointense to muscle on T1-weighted images and with high signal intensity on T2-weighted and STIR images, (c) an outer ring hypoin-tense on all images, and (d) a peripheral halo hypointense on T1-weighted images. In six of eight cases, a soft-tissue mass was found. The two vertebral abscesses had a less specific appearance, with low signal intensity on T1-weighted images and high signal intensity on T2-weighted and STIR images. Only the peripheral halo was clearly identified in both cases.     

Adrenal tissue characterization with 0.5-T MR imaging: Value of T2*-weighted images

The authors investigated the value of magnetic resonance (MR) imaging at 0.5 T for distinguishing adrenal adenomas from adrenal metastases. The series included 23 adrenal adenomas (18 nonhyperfunctioning, five hyperfunctioning) and 23 adrenal metastases from various organs. Adrenal tumor–liver signal intensity ratios on T1-, T2-, and T2*-weighted images were calculated for adrenal tissue characterization. Adrenal adenomas were more precisely distinguished from adrenal metastases on T2*-weighted images (21 of 23, 91%) than on T2-weighted images (15 of 23, 65%). T1-weighted images were not useful for this distinction. In conclusion, T2*-weighted images were better than routine T2-weighted images for distinguishing adrenal adenomas from adrenal metastases. It can be postulated that the total signal intensity of adrenal adenomas, which contain some fat components, decreased on T2*-weighted images because of an out-of-phase effect.     

Dynamic contrast-enhanced MR imaging assessment of vascularized free fibular grafts

Magnetic resonance (MR) imaging may be a noninvasive method for assessing perfusion of vascularized bone grafts placed for treatment of avascular necrosis. One proximal femur of seven beagles was devascularized, with insertion of a vascularized fibular graft. MR imaging at 1 week (seven dogs) and 6 weeks (five dogs) after surgery included pre- and postcontrast spin-echo sequences, unenhanced twodimensional time-of-flight (TOF) vascular imaging, and dynamic gradient-echo imaging during infusion of gadolinium. Relative signal intensity values of selected regions obtained from the dynamic gradientecho images were plotted as percent enhancement versus time. In the operated hip, MR imaging did not show enhancement in six of seven femoral heads and greater trochanters at 1 week after surgery, with similar results after 6 weeks. MR imaging of fibular grafts 6 weeks after surgery showed an initial rapid increase in enhancement and a subsequent slower increase in five of five dogs, although no enhancement was seen in six of seven dogs at 1 week. These findings contrasted with a rapid initial increase in enhancement followed by slow decline in non-operated hips. Two-dimensional TOP imaging did not show the vascular pedicle of the graft in any dog. Findings of radionuclide bone scanning performed 1 week after surgery were consistent with devascularization of the operated femur and fibular graft. However, tetracycline distribution and histologic findings confirmed the viability of five of five grafts within the devascularized femurs 6 weeks after surgery. Thus, dynamic contrast-enhanced MR imaging at 6 weeks after surgery is valuable for assessing vascular bone graft perfusion, while similar imaging at 1 week may suggest otherwise.     

Pericerebellar fluid collections in infancy,sequelae of birth injury? A retrospective CT study

Summary Retrospective analysis of axial CT scans from 600 consecutive pediatric patients revealed 37 patients (6%) with abnormal low density pericerebellar spaces. Fourteen of these 37 patients (38%) were diagnosed as cerebellar atrophy, whereas 23 of the 37 patients (62%) were diagnosed as mass-like pericerebellar fluid collections. Detailed analysis of the morphology of these spaces suggests that the CT criteria proposed in this paper distinguish between (a) those low attenuation pericerebellar spaces that represent cisternal dilatation caused by cerebellar atrophy (Group I — Atrophy) and (b) those low attenuation pericerebellar spaces that represent low density mass-like collections of fluid which distort a relatively normal cerebellum (Group II — Collections). Analysis of the medical records of the patients in Group II — Collections reveal a high incidence of prematurity, developmental delay, difficult birth and head trauma, possibly indicating that such collections represent sequelae of birth.     

Localized proton MR spectroscopy of the brain in children

Small-voxel (3.0–8.0 cm³), magnetic resonance (MR) imaging–guided proton MR spectroscopy was performed in 54 patients (aged 6 days to 19 years) with intracranial masses (n = 16), neurodegenerative disorders (n = 34), and other neurologic diseases (n = 4) and in 23 age-matched control subjects without brain disease. A combined short TE (18 msec) stimulatedecho acquisition mode (STEAM) and long TE (135 and/or 270 msec) spin-echo point-resolved spatially localized spectroscopy (PRESS) protocol, using designed radio-frequency pulses, was performed at 1.5 T. STEAM spectra revealed short T2 and/or strongly coupled metabolites; prominent resonances were obtained from N-acetyl aspartate (NAA), choline-containing compounds (Cho), and total creatine (tCr). Lactate was well resolved with the long TE PRESS sequence. Intracranial tumors were readily differentiated from cerebrospinal fluid (CSF) collections. All tumors showed low NAA, high Cho, and reduced tCr levels. Neurodegenerative disorders showed low or absent NAA levels and enhanced mobile lipid, glutamate and glutamine, and inositol levels, consistent with neuronal loss, gliosis, demyelination, and amino acid neuro-toxicity. Preliminary experience indicates that proton MR spectroscopy can contribute in the evaluation of central nervous system abnormalities of infants and children.