In vivo Characterization of Four 18F-Labeled S1PR1 Tracers for Neuroinflammation

Molecular Imaging and Biology - The sphingosine-1-phosphate receptor 1 (S1PR1) is an important biomarker for imaging inflammation in the central nervous system (CNS). Herein, we report our recent...     

Comparison of Somatostatin Receptor 2-Targeting PET Tracers in the Detection of Mouse Atherosclerotic Plaques

Purpose

Rupture-prone atherosclerotic plaques are characterized by accumulation of macrophages, which have shown to express somatostatin type 2 receptors. We aimed to investigate whether somatostatin receptor-targeting positron emission tomography (PET) tracers, [⁶⁸Ga]DOTANOC, [¹⁸F]FDR-NOC, and [⁶⁸Ga]DOTATATE, can detect inflamed atherosclerotic plaques.

Procedures

Atherosclerotic IGF-II/LDLR^?/?ApoB^100/100 mice were studied in vivo and ex vivo for tracer uptake into atherosclerotic plaques. Furthermore, [⁶⁸Ga]DOTANOC and [⁶⁸Ga]DOTATATE were compared in a head-to-head setting for in vivo PET/X-ray computed tomography (CT) imaging characteristics.

Results

Ex vivo uptake of [⁶⁸Ga]DOTANOC and [⁶⁸Ga]DOTATATE in the aorta was higher in atherosclerotic mice compared to control C57Bl/6N mice, while the aortic uptake of [¹⁸F]FDR-NOC showed no genotype difference. Unlike [¹⁸F]FDR-NOC, [⁶⁸Ga]DOTANOC and [⁶⁸Ga]DOTATATE showed preferential binding to atherosclerotic plaques with plaque-to-wall ratio of 1.7?±?0.3 and 2.1?±?0.5, respectively. However, the aortic uptake and aorta-to-blood ratio of [⁶⁸Ga]DOTANOC were higher compared to [⁶⁸Ga]DOTATATE in in vivo PET/CT imaging.

Conclusion

Our results demonstrate superior applicability for [⁶⁸Ga]DOTANOC and [⁶⁸Ga]DOTATATE in the detection of atherosclerotic plaques compared to [¹⁸F]FDR-NOC.

     

Quantitative Analysis and Parametric Imaging of 18F-Labeled Monomeric and Dimeric RGD Peptides Using Compartment Model

Purpose

Non-invasive PET imaging with radiolabeled RGD peptides for ??_v??₃ integrin targeting has become an important tool for tumor diagnosis and treatment monitoring in both pre-clinical and clinical studies. To better understand the molecular process and tracer pharmacokinetics, we introduced kinetic modeling in the investigation of ¹⁸F-labeled RGD peptide monomer ¹⁸F-FP-c(RGDyK) (denoted as ¹⁸F-FPRGD) and dimer ¹⁸F-FP-PEG3-E[c(RGDyK)]₂ (denoted as ¹⁸F-FPPRGD2).

Procedures

MDA-MB-435 tumor-bearing mice underwent 60?min dynamic PET scans following the injection of either ¹⁸F-FPRGD or ¹⁸F-FPPRGD2. Blocking studies with pre-injection of a blocking mass dose were performed for both monomeric and dimeric RGD groups. ¹⁸F-FPRAD (RAD) was used as a negative control. Kinetic parameters (K ₁, k ₂, k ₃, k ₄) of a three-compartment model were fitted to the dynamic data to allow quantitative comparisons between the monomeric and dimeric RGD peptides.

Results

Dimeric RGD peptide tracer showed significantly higher binding potential (Bp_ND?=?k₃/k₄, 5.87?±?0.31) than that of the monomeric analog (2.75?±?0.48, p?=?0.0022, n?=?4/group). The Bp_ND values showed a significantly greater ratio (dimer/monomer ~2.1) than the difference in %ID/g uptake measured from static images (dimer/monomer ~1.5, p?=?0.0045). Significant decrease in Bp_ND was found in the blocked groups compared with the unblocked ones (dimer p?=?0.00024, monomer p?=?0.005, n?=?4/group). Similarly, the RAD control group showed the lowest Bp_ND value among all the test groups, as the RAD peptide does not bind to integrin ??_v??₃. Volume of distribution (V _T?=?K ₁/k ₂(1?+?k ₃/k ₄)) could be separated into non-specific (V _ND?=?K ₁/k ₂) and specific (V _S?=?K ₁ k ₃/(k ₂ k ₄)) components. Specific distribution volume (V _S) was the dominant component of V _T in the unblocked groups and decreased in the blocked groups. Unblocked RGD dimer also showed higher V _S than that of the monomer (dimer V _S?=?2.38?±?0.15, monomer V _S?=?0.90?±?0.17, p?=?0.0013, n?=?4/group), well correlated with Bp_ND calculations. Little difference in V _ND was found among all groups. Moreover, parametric maps allowed quantitative analysis at voxel level and provided higher tumor-to-background contrast for Bp_ND maps than the static images. Tumor heterogeneity in kinetic parameters was found in parametric images, which could not be clearly identified in static intensity images.

Conclusions

The pharmacokinetics of both monomeric and dimeric RGD peptide tracers was compared, and the RGD dimers showed significantly higher binding affinity than the monomeric analogs. Kinetic parameters were demonstrated to be valuable for separating specific and non-specific binding and may allow more sensitive and detailed quantification than simple standardized uptake value analysis.     

三种术式子宫切除的效果比较

[目的]探讨经腹子宫全切术(TAH)、阴式子宫全切术(TVH)、腹腔镜辅助下阴式子宫全切术(LAVH)的特点及效果.[方法]回顾性分析2002年1月至2005年12月间TAH 1 060例、TVH 72例、LAVH 59例的临床资料.[结果]TAH组的手术时间(78.7±6.3)min显著短于TVH组(95.2±30.2)min和LAVH组(90.2±30.7)min;术中出血量LAVH组(100±55.1)ml和TVH(110±56.1)ml显著少于TAH组(139.3±7.8)ml;术后镇痛率TAH组(74.1%,785例)显著高于TVH组(20.8%,15例)和LAVH组(18.6%,11例);术后住院时间TAH组(12.1±1.1)d显著长于TVH组(8.5±4.2)d和LAVH组(5.5±1.3)d;术后发热率TAH组(5.9%,63例),TVH组(4.2%,3例),LAVH组(5.1%,3例)差异均无显著性.[结论]TVH和LAVH创伤小、病人痛苦少,术后恢复快.而LAVH适应的指征更宽.     

不同吸氧去氮法对全麻诱导期无通气期安全时限影响的比较

目的：探讨不同吸氧去氮方法对全麻诱导期无通气期安全时限的影响。方法：45例气管插管患者随机分为常规吸氧去氮组（3MIN组）、30 s深呼吸4次组（4DB组）与60 s深呼吸8次组（8DB组）。所有患者入手术室后在呼吸空气情况下采集动脉血气标本测定血气分析,并记录SpO2值,吸氧结束时记录SpO2和动脉血的血气分析。记录各例患者SpO2降至97%、95%、93%的时间,在SpO2降至93%时采集动脉血标本测定血气分析。结果：三组SpO2降至97%、95%、93%各时点的时间,3MIN组患者与8DB组相近（P〉0.05）,而均明显长于4DB组（P〈0.05）;吸氧后动脉血二氧化碳分压（PaCO2）值三组相近,但在SpO2降至93%时点,3MIN组与8DB组的PaCO2值均明显高于4DB组（P〈0.05）;吸氧后PaO2值3MIN组与8DB组相近（P〉0.05）,而均明显高于4DB组（P〈0.05）。结论：全麻诱导前的给氧方法中,60 s深呼吸8次法、传统吸氧去氮法的吸氧去氮效果明显优于30 s深呼吸4次法。     

Development and In Vivo Preclinical Imaging of Fluorine-18-Labeled Synaptic Vesicle Protein 2A (SV2A) PET Tracers

Molecular Imaging and Biology - Synaptic vesicle protein 2A (SV2A) serves as a biomarker of synaptic density and positron emission tomography (PET) imaging of SV2A could provide a tool to assess...     

94例子宫肌瘤剔除术的3种术式临床比较

【目的】评价开腹子宫肌瘤剔除术（TAM）、阴式子宫肌瘤剔除术（TVM）、腹腔镜下子宫肌瘤剔除术（LM）的疗效及优缺点。【方法】回顾分析TAM33例,TVM33例,LM28例的临床资料。【结果]TVM组手术时间为（62．73±3．67）min,手术时间最短,LM组次之,为（94．82±3．81）min,TAM组最长,为（98．79±4．96）min。TVM组和后两组比较均有统计学意义（P〈0．01）。TAM组术后肛门排气时间长于TVM组和LM镜组,有统计学意义（P〈0．01）。TAM组术后住院天数均长于TVM组和LM组,有统计学差异（P〈0．01）。【结论】3种手术方式各有其优缺点,手术方法的抉择应做到因人而异。     

A Comparison of Three Cervical Immobilization Devices

Objective. Prehospital cervical spinal cord injuries (SCIs) are rare but potentially catastrophic. Although spinal immobilization is resource-intensive, emergency medical services (EMS) personnel commonly immobilize trauma patients to prevent exacerbation of unrecognized SCI during transport. We compared the stabilization properties of a novel rigid, cervical immobilization collar (XCollar) with those of one-piece andtwo-piece rigid collars commonly used in the prehospital setting. Methods. This was a prospective laboratory study of healthy adult volunteers to determine total cervical motion in the horizontal, coronal, andsagittal planes in both seated andsupine positions. Goniometric techniques were used to measure head andneck movement after marking anatomic landmarks. Ranges of motion were compared with a one-way analysis of variance (ANOVA). A Bonferroni correction was applied for multiple comparisons, setting significance at p ≤ 0.004. Results. Twenty-five subjects (11 men; 14 women) completed the study. The subject pool represented a wide range of morphometrics. For most measurements, the XCollar permitted 10–15 millimeters of movement when applied without manual cervical stabilization. This was less than the movement permitted by both comparison collars. On average, the XCollar permitted less than 10 millimeters of movement in the sagittal andhorizontal planes when the subject was in the seated position. Conclusions. The XCollar provided superior cervical stabilization without augmentation by manual stabilization in healthy adult volunteers in both the seated andsupine positions when compared with other one-piece andtwo-piece rigid cervical collars. Although maximal stabilization was achieved only after the subjects were secured to a long spine board with a cervical immobilization device, the XCollar can provide an acceptable alternative to manual cervical stabilization in situations where the number of patients exceeds the number of EMS providers available to provide care.     

Current and Future Status of Blood Flow Tracers

Myocardial perfusion imaging is important for the management of patients with suspected or known coronary artery disease. Nuclear cardiology is the most widely used noninvasive approach for the assessment of myocardial perfusion. The available single-photon emission CT (SPECT) flow agents are characterized by a rapid myocardial extraction and by a cardiac uptake proportional to blood flow. In addition, different positron emission tomography (PET) tracers may be used for the absolute quantitative measurement of myocardial blood flow and coronary flow reserve. However, the available SPECT and PET tracers for myocardial perfusion imaging have some limitations that must be considered to maximize their clinical applications and there is still a well-recognized need for the development of new perfusion tracers with more ideal properties. This review illustrates the current status and the future perspectives of blood flow tracers for SPECT and PET myocardial perfusion imaging.     

Metabolic and Molecular Imaging with Hyperpolarised Tracers

Since reaching the clinic, magnetic resonance imaging (MRI) has become an irreplaceable radiological tool because of the macroscopic information it provides across almost all organs and soft tissues within the human body, all without the need for ionising radiation. The sensitivity of MR, however, is too low to take full advantage of the rich chemical information contained in the MR signal. Hyperpolarisation techniques have recently emerged as methods to overcome the sensitivity limitations by enhancing the MR signal by many orders of magnitude compared to the thermal equilibrium, enabling a new class of metabolic and molecular X-nuclei based MR tracers capable of reporting on metabolic processes at the cellular level. These hyperpolarised (HP) tracers have the potential to elucidate the complex metabolic processes of many organs and pathologies, with studies so far focusing on the fields of oncology and cardiology. This review presents an overview of hyperpolarisation techniques that appear most promising for clinical use today, such as dissolution dynamic nuclear polarisation (d-DNP), parahydrogen-induced hyperpolarisation (PHIP), Brute force hyperpolarisation and spin-exchange optical pumping (SEOP), before discussing methods for tracer detection, emerging metabolic tracers and applications and progress in preclinical and clinical application.     

A Comparison of Three Measures of Elder Abuse

PURPOSE: To present a comparison of three measures for assessing elder abuse. DESIGN AND METHODS: Three measures for assessing elder abuse were identified through a literature review. The characteristics and uses of each measure were reviewed and evaluated. FINDINGS: The Indicators of Abuse (IOA) is a 22-item tool for discriminating abuse and nonabuse cases; it is completed by a health care professional after a home assessment is conducted. The Elder Abuse and Neglect Assessment (EAI) is a 44-item scale comprised of seven sections to review signs, symptoms, and subjective complaints of elder abuse, neglect, exploitation, and abandonment; it can be used by health care providers in all clinical settings. The Elder Abuse Screening Test (EAST) is a 15-item tool to be completed by a health care provider based on the patient's responses. This screening tool is limited because of the small unrepresentative samples used to test it, the low internal consistency, and a relatively high false-negative rate. CONCLUSIONS: An instrument to accurately assess elder abuse in long-term care is needed. Proper identification of elder abuse is the first step in assisting victims in dealing with abusive situations.     

3种胃管固定方法的效果探讨

目的探讨3种胃管固定方法的临床应用效果。方法将120例留置胃管的患者按随机数字表法分为传统组、额头固定组和改良组,每组40例,分别采用传统法、额头固定法和改良固定法进行置管固定,对3组方法的脱管原因(患者自拔、咳嗽或喷嚏、患者自行翻身、胶布松脱等)、脱管发生率、胃管留置时间及留置效果(对皮肤、咽部刺激,舒适度、脱管等)进行比较。结果改良组因不同原因造成的脱管发生率明显低于传统组和额头固定组、胃管留置时间长于传统组和额头固定组、胃管留置效果优于传统组和额头固定组(均P<0.05)。结论改良固定法可有效地增加胃管的牢固性,防止胃管脱出,增加患者舒适度,有效地降低费用。     

Comparison of Thrombophlebitis Associated with Three Cephalosporin Antibiotics

A double-blind study with volunteers was performed to determine the incidence and severity of thrombophlebitis associated with cephalothin, cephapirin, cefamandole, and a water control. Although there were no statistical differences in the incidence of thrombophlebitis, cephalothin resulted in significantly more severe thrombophlebitis compared with the other agents.     

几种包皮环切术式的临床观察比较

目的:探讨不同方法行包皮环切术的临床效果.方法:回顾性分析2008年1月至2011年8月采用不同方法行包皮环切术的临床资料1 247例.其中传统包皮环切术982例、激光袖套状包皮环切术123例、包皮环环扎术142例,并对其手术平均耗时、水肿消退期时间、术后并发症如术后创口出血、术后感染、术后线头反应、术后伤口裂开、再次手术率,进行临床观察比较.结果:传统包皮环切术组的手术时间(26.8±5.9) min及术后水肿消退时间(13.8±4.5)d分别介于激光袖套状包皮环切术组和包皮环环扎术组之间,3组比较差异均有统计学意义(P＜0.05).在术后并发症发生率和再次手术情况方面,传统包皮环切术组分别是0.7％(7/982)和0.2％ (2/982),激光袖套状包皮环切术组分别是4.9％(6/123)和0.8％(1/123),包皮环环扎术组分别是12.9％(16/142)和4.2％(6/142),3组手术方式对比差异也具有统计学意义(P＜0.05),传统包皮环切术组并发症及再次手术的发生率均最小.结论:激光袖套状包皮环切术手术耗时长、术后恢复期长、术后并发症多.包皮环环扎术手术耗时短、术后恢复快、不残留线头、外形美观,但感染率高,一旦感染伤口易裂开,必须控制感染后重新清创缝合.传统包皮环切术比较包皮环环扎术手术耗时、术后水肿消退期虽长,但术后并发症少,再次手术率低,较为安全可靠.     

Tracers: they're not just for accreditation surveys

Conducting periodic tracers will help your staff improve their performance, enhance communications with other hospital departments, and become more familiar with Joint Commission on Accreditation of Healthcare Organizations standards and terminology. Address specific service lines (i.e., pneumonia, stroke) to identify more targeted opportunities for improvement. Pay particular attention to handoffs and documentation when conducting your own internal tracers. Mock surveys, including tracers, can be valuable tools for ensuring ongoing readiness for Joint Commission visits.     

人工流产中三种镇痛方法的比较

10 99例行人工流产孕妇随机分为 4组 ,3组分别用异丙酚、笑气联合利多卡因、单纯利多卡因术中镇痛 ,对照组不用药。结果镇痛组镇痛总有效率明显高于对照组 (P <0 .0 1) ,无痛率以异丙酚组最高 (P <0 .0 1) ,总有效率笑气联合利多卡因组与异丙酚组相比无显著差异 (P >0 .0 5 )。异丙酚镇痛效果最佳 ,但需呼吸循环监护 ,笑气联合利多卡因镇痛效果佳 ,手术要求简单 ,可在基层医院推广。     

三种高脂血症实验性大鼠模型的比较

目的:比较3种高脂血症大鼠的造模方法,为实验研究选择最佳高脂血症动物模型提供依据。方法:40只SD大鼠随机分为普通饲料喂养(A组)、植物油高脂饲料喂养(B组)、猪油高脂饲料喂养(C组)及脂肪乳剂灌胃喂养(D组)各10只。1个月后比较3组大鼠的总胆固醇(TC)、甘油三酯(TG)、高密度脂蛋白-胆固醇(HDL-C)、低密度脂蛋白-胆固醇(LDL-C)及肝脏形态学改变。结果:与A组比较,TC在B、C、D组均明显升高;TG在C组明显升高;HDL-C在C组明显下降,D组则明显上升;LDL-C在B、C、D组均明显升高(均P0.05,0.01)。结论:综合以上各组大鼠4个指标的升降情况,以猪油固体饲料喂养的大鼠最符合高脂血症诊断标准,且比较接近人类饮食成分及方式,造模效果理想。     

3种不同入径子宫肌瘤剔除术的临床比较

目的比较腹腔镜下子宫肌瘤剔除术(Laparoscopic myomectomy,LM)、经阴道子宫肌瘤剔除术(Transvaginalmyomectomy,TVM)和经腹子宫肌瘤剔除术(Transabdominal myomectomy,TAM)的临床特点,探讨3种术式的利弊。方法回顾性分析2010年7月～2011年10月于天津市中心妇产科医院行子宫肌瘤剔除术患者的临床资料,其中LM组65例,TVM组50例,TAM组75例,对三组患者术中及术后临床指标进行比较。结果 LM组手术时间、住院费用均高于TVM组、TAM组(P<0.05),后两组比较差异无统计学意义(P>0.05);术中出血量、血红蛋白下降程度、术后住院时间及术后镇痛率为LM组