PBR

PBR
  • 文章类型: Journal Article
    本研究旨在评估阻塞性睡眠呼吸暂停综合征(OSAS)患者眼表参数的变化。
    在我们的横断面研究中招募了44名健康志愿者(88只眼)和27名OSAS患者(54只眼)。14例患者分为轻度和中度OSAS,13例患者被归类为重度OSAS。为了评估眼表,进行了以下测试:撕裂弯月面的高度(TMH),第一次非侵入性泪液破裂时间(FNITBUT),平均非侵入性泪液破裂时间(MNITBUT),睑板腺脱落面积评分(Meiboscore),无麻醉SchirmerI(SIT)的撕裂试验,角膜荧光素染色(CFS),部分闪烁率(PBR),脂质层厚度(LLT),眼表疾病指数(OSDI)。从研究中获得的结果在各组之间进行分析和比较。
    FNITBUT,但是,TMH较低。OSDI,CFS,OSAS组的Meiboscore和PBR高于对照组。轻度和中度以及重度OSAS亚组的TMH在统计学上显着降低,OSDI和PBR高于对照组。同时,我们发现两个OSAS亚组之间无显著差异.重度OSAS组的CFS高于轻度和中度OSAS组。显著降低FNITBUT,重度OSAS亚组的MNITBUT和Meiboscore高于对照组,重度OSAS对象的MNITBUT高于轻度和中度OSAS对象。LLT和SIT在对照组和OSAS亚组之间没有显着差异。FNITBUT和MNITBUT与BMI呈显著负相关,而Meiboscore与AHI呈显著正相关。
    OSAS患者有干眼症,而对照组则没有。提示OSAS患者应重视眼表护理。
    UNASSIGNED: This study aimed to evaluate changes in ocular surface parameters among obstructive sleep apnea syndrome (OSAS) patients.
    UNASSIGNED: 44 healthy volunteers (88 eyes) and 27 OSAS patients (54 eyes) were recruited in our cross-sectional study. 14 patients were classified as mild&moderate OSAS, and 13 patients were classified as severe OSAS. For evaluating the ocular surface, the following tests were conducted: the height of tear meniscus (TMH), first non-invasive tear break-up time (FNITBUT), mean non-invasive tear break-up time (MNITBUT), the score of Meibomian gland dropout area (Meiboscore), the tear test of anesthesia-free Schirmer I (SIT), corneal fluorescein staining (CFS), partial blinks rate (PBR), the lipid layer thickness (LLT), ocular surface disease index (OSDI). The results obtained from the study were analyzed and compared among the groups.
    UNASSIGNED: FNITBUT, MNITBUT, and TMH were lower. OSDI, CFS, Meiboscore and PBR were higher in the OSAS group than those in the control group. The mild&moderate as well as the severe OSAS subgroups had statistically significantly lower TMH, and higher OSDI and PBR than the control group. Meanwhile, we found there were no significant differences between two OSAS subgroups. CFS was higher in the severe OSAS group than the mild&moderate OSAS group. Significantly lower FNITBUT, MNITBUT and higher Meiboscore were observed in the severe OSAS subgroup than in the control group, and MNITBUT was higher in severe OSAS objects than in the mild&moderate OSAS objects. LLT and SIT did not exhibit significant differences among control and OSAS subgroups. FNITBUT and MNITBUT showed significantly negative correlations with BMI, while Meiboscore showed a significant positive correlation with AHI.
    UNASSIGNED: Patients with OSAS have a tendence of dry eyes, whereas control subjects do not. This indicates us that the OSAS patients should pay more attention to ocular surface care.
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  • 文章类型: Journal Article
    背景:转运蛋白(TSPO)是一种神经炎症标志。已经产生了不同的TSPO亲和化合物,并且随着时间的推移,放射性标记的技术已经完善。本系统综述的目的是总结用于痴呆和神经炎症成像的新型放射性示踪剂的发展。
    方法:在PubMed,Scopus,Medline,科克伦图书馆,和WebofScience数据库,选择2004年1月至2022年12月发表的研究。公认的研究考虑了TSPO示踪剂的合成,用于痴呆和神经炎症的核医学成像。
    结果:共鉴定出50篇文章。从纳入的研究文献中选择了12篇论文,排除了34篇。因此,最终选择28篇文章进行质量评估。
    结论:在开发用于PET/SPECT成像的特异性和稳定的示踪剂方面已经做出了巨大的努力。18F的长半衰期使该同位素成为11C的优选选择。然而,对此的一个新的限制是神经炎症涉及所有的大脑,这抑制了检测患者轻微炎症状态变化的可能性。对此的部分解决方案是使用小脑作为参考区域并开发更高的TSPO亲和示踪剂。此外,有必要考虑造口剂和外消旋化合物的存在会干扰药理示踪剂的作用并增加图像中的噪声比。
    Translocator protein (TSPO) is a neuroinflammation hallmark. Different TSPO affinity compounds have been produced and over time, the techniques of radiolabeling have been refined. The aim of this systematic review is to summarize the development of new radiotracers for dementia and neuroinflammation imaging.
    An online search of the literature was conducted in the PubMed, Scopus, Medline, Cochrane Library, and Web of Science databases, selecting published studies from January 2004 to December 2022. The accepted studies considered the synthesis of TSPO tracers for nuclear medicine imaging in dementia and neuroinflammation.
    A total of 50 articles was identified. Twelve papers were selected from the included studies\' bibliographies and 34 were excluded. Thus, 28 articles were ultimately selected for quality assessment.
    Huge efforts in developing specific and stable tracers for PET/SPECT imaging have been made. The long half-life of 18F makes this isotope a preferable choice to 11C. An emerging limitation to this however is that neuroinflammation involves all of the brain which inhibits the possibility of detecting a slight inflammation status change in patients. A partial solution to this is using the cerebellum as a reference region and developing higher TSPO affinity tracers. Moreover, it is necessary to consider the presence of distomers and racemic compounds interfering with pharmacological tracers\' effects and increasing the noise ratio in images.
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  • 文章类型: Journal Article
    18kDa转运蛋白(TSPO/PBR)是一种多功能进化高度保守的线粒体外膜蛋白。几十年的研究报道了TSPO/PBR在线粒体胆固醇转运和,因此,类固醇生产。然而,类固醇生成对TSPO/PBR的严格依赖性仍然存在争议。这项研究的目的是提供在基础条件下完全C57BL/6-Tspotm1GuWu(GuwiyangWurra)敲除雄性小鼠(TSPO-KO)的类固醇特征的见解。大脑中的类固醇,肾上腺,通过气相色谱-串联质谱(GC-MS/MS)测量睾丸和血浆。我们发现,在TSPO-KO小鼠中也检测到野生型(WT)小鼠中存在的类固醇,包括孕烯醇酮(PREG),孕激素,矿物质糖皮质激素和雄激素。PREG和大多数代谢物的浓度在基因型之间相似,除了与WT动物相比,TSPO-KO中肾上腺和血浆中5α-减少的孕酮代谢物(PROG)和血浆中5α-减少的皮质酮代谢物(B)的水平显着降低,建议TSPO/PBR的其他调节功能。电压依赖性阴离子选择性通道(VDAC-1)的表达水平,CYP11A1和5α-还原酶在两组之间没有显着差异。因此,在雄性小鼠中tspo基因的完全缺失不会损害体内从头类固醇生成。
    The 18 kDa translocator protein (TSPO/PBR) is a multifunctional evolutionary highly conserved outer mitochondrial membrane protein. Decades of research has reported an obligatory role of TSPO/PBR in both mitochondrial cholesterol transport and, thus, steroid production. However, the strict dependency of steroidogenesis on TSPO/PBR has remained controversial. The aim of this study was to provide insight into the steroid profile in complete C57BL/6-Tspotm1GuWu(GuwiyangWurra)-knockout male mice (TSPO-KO) under basal conditions. The steroidome in the brain, adrenal glands, testes and plasma was measured by gas chromatography coupled to tandem mass spectrometry (GC-MS/MS). We found that steroids present in wild-type (WT) mice were also detected in TSPO-KO mice, including pregnenolone (PREG), progestogens, mineralo-glucocorticosteroids and androgens. The concentrations of PREG and most metabolites were similar between genotypes, except a significant decrease in the levels of the 5α-reduced metabolites of progesterone (PROG) in adrenal glands and plasma and of the 5α-reduced metabolites of corticosterone (B) in plasma in TSPO-KO compared to WT animals, suggesting other regulatory functions for the TSPO/PBR. The expression levels of the voltage-dependent anion-selective channel (VDAC-1), CYP11A1 and 5α-reductase were not significantly different between both groups. Thus, the complete deletion of the tspo gene in male mice does not impair de novo steroidogenesis in vivo.
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  • 文章类型: Journal Article
    Human-caused mortality of wildlife is a pervasive threat to biodiversity. Assessing the population-level impact of fisheries bycatch and other human-caused mortality of wildlife has typically relied upon deterministic methods. However, population declines are often accelerated by stochastic factors that are not accounted for in such conventional methods. Building on the widely applied potential biological removal (PBR) equation, we devised a new population modeling approach for estimating sustainable limits to human-caused mortality and applied it in a case study of bottlenose dolphins affected by capture in an Australian demersal otter trawl fishery. Our approach, termed sustainable anthropogenic mortality in stochastic environments (SAMSE), incorporates environmental and demographic stochasticity, including the dependency of offspring on their mothers. The SAMSE limit is the maximum number of individuals that can be removed without causing negative stochastic population growth. We calculated a PBR of 16.2 dolphins per year based on the best abundance estimate available. In contrast, the SAMSE model indicated that only 2.3-8.0 dolphins could be removed annually without causing a population decline in a stochastic environment. These results suggest that reported bycatch rates are unsustainable in the long term, unless reproductive rates are consistently higher than average. The difference between the deterministic PBR calculation and the SAMSE limits showed that deterministic approaches may underestimate the true impact of human-caused mortality of wildlife. This highlights the importance of integrating stochasticity when evaluating the impact of bycatch or other human-caused mortality on wildlife, such as hunting, lethal control measures, and wind turbine collisions. Although population viability analysis (PVA) has been used to evaluate the impact of human-caused mortality, SAMSE represents a novel PVA framework that incorporates stochasticity for estimating acceptable levels of human-caused mortality. It offers a broadly applicable, stochastic addition to the demographic toolbox to evaluate the impact of human-caused mortality on wildlife.
    La mortalidad de la fauna causada por humanos es una amenaza continua para la biodiversidad. El análisis del impacto a nivel poblacional de la captura pesquera incidental y otras causas humanas de la mortalidad de la fauna comúnmente ha dependido de métodos determinísticos. Sin embargo, las declinaciones poblacionales con frecuencia se aceleran por los factores estocásticos que no son considerados en dichos métodos convencionales. A partir de la ecuación de extirpación biológica potencial (EBP) de extensa aplicación diseñamos una nueva estrategia de modelación poblacional para estimar los límites sustentables de la mortalidad causada por humanos y la aplicamos en un estudio de caso de los delfines nariz de botella afectados por la captura en una pesquería australiana de arrastre demersal. Nuestra estrategia, denominada mortalidad antropogénica sustentable en ambientes estocásticos (MASAM) incorpora la estocasticidad ambiental y demográfica, incluyendo la dependencia que tienen las crías por sus madres. El límite MASAM es el número máximo de individuos que pueden extirparse sin causar un crecimiento poblacional estocástico negativo. Calculamos un EBP de 16.3 delfines por año con base en la mejor estimación de abundancia disponible. Como contraste, el modelo MASAM indicó que sólo podían extirparse entre 2.3 y 8.0 delfines anualmente sin ocasionar una declinación poblacional en un ambiente estocástico. Estos resultados sugieren que las tasas reportadas de captura incidental no son sustentables a largo plazo, a menos que las tasas reproductivas sean sistemáticamente más altas que el promedio. La diferencia entre el cálculo determinístico del EBP y los límites de MASAM mostró que los enfoques determinísticos pueden subestimar el verdadero impacto de la mortalidad de la fauna causada por humanos. Lo anterior resalta la importancia de integrar la estocasticidad al evaluar el impacto de la captura incidental y otras causas humanas de la mortalidad como la caza, las medidas letales de control y las colisiones con turbinas de viento. Aunque el análisis de viabilidad poblacional (AVP) se ha utilizado para evaluar el impacto de la mortalidad causada por humanos, MASAM representa un marco novedoso de AVP que incorpora la estocasticidad para estimar los niveles aceptables de mortalidad causada por humanos. Este enfoque ofrece una adición estocástica de aplicación generalizada para las herramientas demográficas usadas para evaluar el impacto de la mortalidad causada por humanos sobre la fauna.
    在不断变化的情景下估计野生动物死亡率的持续性限度的随机模型 人类造成的野生动物死亡是对生物多样性的普遍威胁。目前, 通常依赖于确定性方法来评估渔业副渔获物和其它人为造成的野生动物死亡在种群水平上的影响。然而, 随机因素往往会加速种群数量的下降, 但这种常规方法没有将其纳入考虑。我们在已得到广泛应用的生物可移除潜在量(Potential Biological Removal, PBR)方程的基础上, 设计了一种新的种群建模方法来估计人为造成的死亡的可持续限度, 并将其应用于澳大利亚底层拖网渔业中受影响的瓶鼻海豚的案例研究。我们的方法可以称为“随机环境中的可持续人为影响死亡率(SAMSE)”, 包含了环境和种群的随机性, 还包括了后代对母亲的依赖性。SAMSE的极限是指在不引起负面的种群随机增长的情况下可以移除的最大个体数。我们根据现有最佳的丰度估计, 计算出海豚的生物可移除潜在量为每年16.2头。相比之下, SAMSE模型则显示, 在随机环境中, 为了不引起种群下降, 每年只能移除2.3至8.0头海豚。这些结果表明, 除非繁殖率持续高于平均水平, 否则长期来看报告的副渔获率是不可持续的。确定性的PBR计算和SAMSE限制之间的差异表明, 确定性方法可能低估了人为造成野生动物死亡的真实影响。这突出了整合随机性在评估副渔获或其它人为造成的死亡(如狩猎、灭杀控制措施和风力涡轮机碰撞)对野生动物的影响中的重要性。尽管种群生存力分析(PVA)已被用于评估人为造成死亡的影响, 但SAMSE代表了一个包含随机性的PVA新框架, 可以用于估计人为造成死亡的可接受水平。它为种群统计学工具补充了一种广泛适用的随机性方法, 以评估人类造成的死亡对野生动物的影响。【翻译:胡怡思;审校:聂永刚】.
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  • 文章类型: Journal Article
    背景:这是一项前瞻性队列研究,采用外侧胸壁穿支皮瓣(LCWPF)进行部分乳房再造(PBR),以促进乳腺癌手术女性的乳房保护手术(BCS)。进行该研究以研究临床和癌症结果。
    方法:被诊断为导管原位癌(DCIS)或乳腺癌的患者同意接受BCS与PBR与LCWPF。维持了一个前瞻性数据库,以收集有关临床病理特征的信息,并发症,和后续行动。多年来,患者被要求填写匿名的PROM问卷。询问已完成5年随访的妇女的医院电子记录,以评估复发/事件的发展。
    结果:在2011年至2018年期间,共有105例患者接受了LCWPFs的PBR。其中,74%的人接受了癌症切除术和PBR作为一项手术,而26%的人接受了PBR作为两阶段方法。一期术前成像的中位肿瘤大小为30mm,两期术前为39.5mm(p值=0.003)。并发症发生率低,切缘再次手术率为10%,4%的人最终需要乳房切除术。患者和临床医生在80%以上的病例中报告了良好到出色的美学结果。局部复发率(LR)为2%,远处复发率10.5%,无病生存率(DFS)86%,在4.5年的中位随访时间,远端无病生存率(DDFS)为89%,总生存率(OS)为94.8%.这个程序提供了一种有效的肿瘤治疗方法,避免乳房切除术与良好的美容效果。后续数据确定了这种方法的安全性。
    结论:这是首次发表的PBR患者复发和生存数据系列。我们打算继续进行数据收集,以评估10年后的长期结果。作者建议考虑使用这种技术来促进BCS并避免乳房切除术。
    背景:不适用。
    BACKGROUND: This is a prospective cohort study of partial breast reconstruction (PBR) with a lateral chest wall perforator flap (LCWPF) to facilitate breast conservation surgery (BCS) for women undergoing surgery for breast cancer. The study was undertaken to study the clinical and cancer outcomes.
    METHODS: Patients diagnosed with ductal carcinoma in situ (DCIS) or breast cancer who consented to undergo BCS with PBR with LCWPF were included in the study. A prospective database has been maintained to collect information on clinico-pathological features, complications, and follow-up. Patients were asked to complete an anonymised PROM questionnaire over the years. The hospital electronic records were interrogated for women who have completed 5 years follow-up to assess for development of recurrence/events.
    RESULTS: A total of 105 patients underwent PBR with LCWPFs between 2011 and 2018. Of these, 74% underwent cancer resection and PBR as one operation whilst 26% underwent PBR as a two-stage approach. The median tumor size on pre-op imaging was 30 mm for the one-stage approach and 39.5 mm for the two-stage approach (p-value=0.003). The complication rates were low and the re-operation rate for close margins was 10%, with 4% eventually requiring mastectomy. Good-to-excellent esthetic outcomes were reported in more than 80% of cases by patients and clinicians. The local recurrence rate (LR) was 2%, distant recurrence rate 10.5%, disease free survival (DFS) 86%, distant disease-free survival (DDFS) 89% and overall survival (OS) 94.8% at 4.5 years median follow-up. This procedure provides an effective oncological approach, avoiding mastectomy with a good-to-excellent cosmetic outcome. The follow-up data establishes the safety of this approach.
    CONCLUSIONS: This is the first published series of recurrence and survival data in patients undergoing PBR. We intend to continue with data collection to assess long-term outcomes beyond 10 years. The authors would recommend consideration of this technique to facilitate BCS and avoid mastectomy.
    BACKGROUND: Not applicable.
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  • 文章类型: Journal Article
    本文介绍了实验性无源双基地雷达(PBR)系统中的最新研究和多目标跟踪,该系统利用了通过多静态多普勒频移的大量非合作AM无线电信号。然而,由于复杂的数据关联假设和实际场景中没有直接使用的跟踪算法,这给PBR系统中多个空间分布式AM无线电照明器用于多目标跟踪带来了挑战。为了解决这些问题,在自主开发的系统中,经过一系列关键的阵列信号处理技术,通过构建非线性测量模型,提出了一种新颖的方法,通过使用高斯混合(GM)中的无迹变换(UT)实现迭代校正器基数平衡多目标多伯努利(CBMeMBer)来适应非线性模型。仿真和实验结果分析验证了该方法用于实际PBR系统运动多目标跟踪的可行性。
    This paper presents a description of recent research and the multi-target tracking in experimental passive bistatic radar (PBR) system taking advantage of numerous non-cooperative AM radio signals via multi-static doppler shifts. However, it raises challenges for use by multiple spatially distributed AM radio illuminators for multi-target tracking in PBR system due to complex data association hypotheses and no directly used tracking algorithm in the practical scenario. To solve these problems, after a series of key array signal processing techniques in the self-developed system, by constructing a nonlinear measurement model, the novel method is proposed to accommodate nonlinear model by using the unscented transformation (UT) in Gaussian mixture (GM) implementation of iterated-corrector cardinality-balanced multi-target multi-Bernoulli (CBMeMBer). Simulation and experimental results analysis verify the feasibility of this approach used in a practical PBR system for moving multi-target tracking.
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  • 文章类型: Journal Article
    猪白细胞抗原(SLA)通过区分自身和外来抗原并启动免疫反应,在控制免疫反应中起着核心作用。对SLA多态性的研究表明,SLA等位基因变异体之间存在关联,免疫反应,和抗病性。SLA多态性是由于宿主-病原体共同进化导致对不同环境的适应性改善,使SLA成为比较多样性研究的关键基因组区域。虽然当地适应的非洲猪体型较小,它们在恶劣的环境条件下具有增强的复原力和强大的免疫系统,据报道对某些疾病具有耐受性,包括非洲猪瘟。然而,这些猪的SLA多样性数据不可用。我们对来自HomaBay的无关本地适应的家猪的SLA进行了表征,肯尼亚,还有异国情调的猪和疣猪.我们使用逆转录聚合酶链反应(RT-PCR)基于序列的分型(SBT)方法,对这三种真菌中功能表达的SLAI类(SLA-1,SLA-2)和II类(DQB1)库进行了SLA比较多样性。我们的数据显示,与外来猪相比,适应当地的猪和疣猪的遗传多样性更高。在SLA-1,SLA-2和DQB1基因座的肽结合区域中,核苷酸取代率更高,指示适应性进化。我们在三个SLA基因座中获得了高等位基因频率,包括一些品种特异性的私人等位基因,如果证实与增强的弹性相关,这可以指导育种者通过选择来增加他们的频率。我们的研究有助于在自然环境中自由放养的动物种群中增加遗传多样性的知识,利用本地适应的肯尼亚猪的第一个DQB1基因数据。
    Swine leukocyte antigen (SLA) plays a central role in controlling the immune response by discriminating self and foreign antigens and initiating an immune response. Studies on SLA polymorphism have demonstrated associations between SLA allelic variants, immune response, and disease resistance. The SLA polymorphism is due to host-pathogen co-evolution resulting in improved adaptation to diverse environments making SLA a crucial genomic region for comparative diversity studies. Although locally-adapted African pigs have small body sizes, they possess increased resilience under harsh environmental conditions and robust immune systems with reported tolerance to some diseases, including African swine fever. However, data on the SLA diversity in these pigs are not available. We characterized the SLA of unrelated locally-adapted domestic pigs from Homa Bay, Kenya, alongside exotic pigs and warthogs. We undertook SLA comparative diversity of the functionally expressed SLA class I (SLA-1, SLA-2) and II (DQB1) repertoires in these three suids using the reverse transcription polymerase chain reaction (RT-PCR) sequence-based typing (SBT) method. Our data revealed higher genetic diversity in the locally-adapted pigs and warthogs compared to the exotic pigs. The nucleotide substitution rates were higher in the peptide-binding regions of the SLA-1, SLA-2, and DQB1 loci, indicative of adaptive evolution. We obtained high allele frequencies in the three SLA loci, including some breed-specific private alleles, which could guide breeders to increase their frequency through selection if confirmed to be associated with enhanced resilience. Our study contributes to the growing body of knowledge on genetic diversity in free-ranging animal populations in their natural environment, availing the first DQB1 gene data from locally-adapted Kenyan pigs.
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  • 文章类型: Journal Article
    背景:由于其在小胶质细胞中的飙升表达,因此易位蛋白18kDa被认为是神经炎症的重要生物标志物。该过程对于各种神经障碍是常见的。DPA-714是一种有效的TSPO特异性配体,在用正电子发射放射性核素氟-18取代氟-19后,可用于正电子发射断层扫描。[18F]DPA-714能够在体内非侵入地可视化炎症过程。这种示踪剂的放射性标记在文献中有很好的描述,包括临床使用的验证。这里,我们报告了对该过程的显着增强,该过程导致在流行的基于盒的系统上设计完全符合GMP的[18F]DPA-714的稳健合成,TrasisAllinOne,提升可靠性,吞吐量,并引入显著程度的简单性。
    结果:[18F]DPA-714是在良好的离去基团上使用经典的亲核脂肪族取代合成的,甲苯磺酸盐,使用[18F]氟化物,使用四乙基碳酸氢铵在乙腈中,在100°C。该过程在TrasisAllinOne合成器上使用内部设计的盒和序列完全自动化。相对较小的前体负载为4毫克,[18F]DPA-714在合成结束时始终具有55-71%(n=6)的高放射化学产率和117-350GBq/µmol的摩尔活性。与单个生产批次,从31-42GBq[18F]氟化物开始,可以生产13-20GBq之间的示踪剂,实现多中心研究。
    结论:据我们所知,本文提出的过程是最有效的[18F]DPA-714合成,具有良好的GMP合规性。使用TrasisAllinOne合成器提高了可靠性,并允许对生产人员进行快速培训。
    BACKGROUND: The translocator protein 18 kDa is recognised as an important biomarker for neuroinflammation due to its soaring expression in microglia. This process is common for various neurological disorders. DPA-714 is a potent TSPO-specific ligand which found its use in Positron Emission Tomography following substitution of fluorine-19 with fluorine-18, a positron-emitting radionuclide. [18F]DPA-714 enables visualisation of inflammatory processes in vivo non-invasively. Radiolabelling of this tracer is well described in literature, including validation for clinical use. Here, we report significant enhancements to the process which resulted in the design of a fully GMP-compliant robust synthesis of [18F]DPA-714 on a popular cassette-based system, Trasis AllinOne, boosting reliability, throughput, and introducing a significant degree of simplicity.
    RESULTS: [18F]DPA-714 was synthesised using the classic nucleophilic aliphatic substitution on a good leaving group, tosylate, with [18F]fluoride using tetraethylammonium bicarbonate in acetonitrile at 100∘C. The process was fully automated on a Trasis AllinOne synthesiser using an in-house designed cassette and sequence. With a relatively small precursor load of 4 mg, [18F]DPA-714 was obtained with consistently high radiochemical yields of 55-71% (n=6) and molar activities of 117-350 GBq/µmol at end of synthesis. With a single production batch, starting with 31-42 GBq of [18F]fluoride, between 13-20 GBq of the tracer can be produced, enabling multi-centre studies.
    CONCLUSIONS: To the best of our knowledge, the process presented herein is the most efficient [18F]DPA-714 synthesis, with advantageous GMP compliance. The use of a Trasis AllinOne synthesiser increases reliability and allows rapid training of production staff.
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  • 文章类型: Journal Article
    尽管有大量证据表明Rac1位于细胞核,关于核Rac1的功能和生物学意义知之甚少。这里,我们表明,响应EGF,Rac1易位到核斑点,并与核斑点标记丝氨酸/富含精氨酸的剪接因子2(SRSF2)共同定位在Cos-7细胞中。我们还表明,Rac1的核斑点定位取决于其T108磷酸化,并由包含核定位信号和Rac1GTPase活性的Rac1多聚碱基区(PBR)促进。为了深入了解Rac1在核斑点中的功能,我们在细胞核中搜索了Rac1结合蛋白。我们分离了HEK293细胞的核级分,并与GST-Rac1和拟磷酸GST-Rac1T108E孵育。我们鉴定了463种与GST-Rac1T108E相关的蛋白质,但不与GST-Rac1通过LC-MS。这些蛋白质的三个值得注意的组是:异质核核糖核蛋白(hnRNP),小核核糖核蛋白(snRNPs),和SRSF,所有这些都与前mRNA剪接有关,并与核斑点有关。我们通过免疫共沉淀进一步表明,Rac1响应EGF与SRSF2,hnRNPA1和U2A相互作用。这种相互作用取决于T108磷酸化,并受Rac1PBR和GTP酶活性的促进。我们表明,hnRNPA1以与Rac1相似的方式响应EGF而在细胞核中易位。Rac1仅与U2A\'部分共定位,并定位到与核斑点相邻的实际剪接位点。最后,我们表明Rac1调节EGF诱导的前mRNA剪接,这是由T108磷酸化介导的。我们得出结论,为了回应EGF,T108磷酸化Rac1靶向核斑点,与参与前mRNA剪接的多组蛋白质相互作用,并调节EGF诱导的前mRNA剪接。
    Despite significant evidence that Rac1 is localized to the nucleus, little is known regarding the function and biological significance of nuclear Rac1. Here, we showed that in response to EGF Rac1 was translocated to nuclear speckles and co-localized with the nuclear speckle marker Serine/arginine-rich splicing factor 2 (SRSF2) in Cos-7 cells. We also showed that the nuclear speckle localization of Rac1 was dependent on its T108 phosphorylation and facilitated by Rac1 polybasic region (PBR) that contains a nuclear localization signal and Rac1 GTPase activity. To gain insight into the function of Rac1 in nuclear speckles, we searched for Rac1 binding proteins in the nucleus. We isolated nuclear fraction of HEK 293 cells and incubated with GST-Rac1 and the phosphomimetic GST-Rac1T108E. We identified 463 proteins that were associated with GST-Rac1T108E, but not with GST-Rac1 by LC-MS/MS. Three notable groups of these proteins are: the heterogeneous nuclear ribonucleoproteins (hnRNPs), small nuclear ribonucleoproteins (snRNPs), and SRSFs, all of which are involved in pre-mRNA splicing and associated with nuclear speckles. We further showed by co-immunoprecipitation that Rac1 interacts with SRSF2, hnRNPA1, and U2A\' in response to EGF. The interaction is dependent on T108 phosphorylation and facilitated by Rac1 PBR and GTPase activity. We showed that hnRNPA1 translocated in and out of nucleus in response to EGF in a similar pattern to Rac1. Rac1 only partially colocalized with U2A\' that localizes to the actual splicing sites adjacent to nuclear speckle. Finally, we showed that Rac1 regulated EGF-induced pre-mRNA splicing and this is mediated by T108 phosphorylation. We conclude that in response to EGF, T108 phosphorylated Rac1 is targeted to nuclear speckles, interacts with multiple groups of proteins involved in pre-mRNA splicing, and regulates EGF-induced pre-mRNA splicing.
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  • 文章类型: Journal Article
    聚唾液酸(polySia)是一种不寻常的聚糖,其翻译后修饰哺乳动物细胞中的神经细胞粘附分子(NCAM)蛋白。polySia-NCAM的上调表达与许多转移性人类癌症和神经认知过程中的肿瘤进展有关。α2,8-聚唾液酸转移酶(polySTs)的ST8Sia家族的两个成员,当活化的单磷酸胞苷(CMP)-唾液酸(CMP-Sia)易位到高尔基体的内腔中时,ST8SiiaII(STX)和ST8SiiaIV(PST)都催化polySia的合成。polyST中的两个关键多元结构域,多碱基区(PBR)和多唾液酸转移酶结构域(PSTD)是NCAM蛋白的多聚唾液酸化必需的。然而,描述聚唾液酸化所需的相互作用的精确分子细节仍然未知。在这项研究中,我们假设PSTD与CMP-Sia和polySia相互作用以催化NCAM蛋白的聚唾液酸化。为了检验这个假设,我们合成了来自ST8SiaIV基因序列的35个氨基酸的PSTD肽,并将其用于研究其与CMP-Sia的相互作用,和PolySia。我们的结果表明,对于PSTD-CMP-Sia相互作用,最大的化学位移扰动(CSP)是在短H1螺旋中的氨基酸残基V251至A254,位于PSTD的N端附近。然而,在长H2螺旋中的氨基酸残基R259至T270中观察到用于PSTD-polySia相互作用的更大的CSP值。这些差异表明CMP-Sia优先结合短H1螺旋和较长H2螺旋之间的结构域。相比之下,polysia主要与PSTD的长H2螺旋结合。对于PSTD-polysia相互作用,在PSTD中长H2螺旋的N和C末端之间的20个氨基酸残基中观察到峰强度的显着降低,表明当polySia与PSTD结合时,这些残基的运动较慢。PSTD-CMP-Sia之间相互作用的特定特征,通过将其800MHz衍生的HSQC光谱与PSTD-Sia的光谱进行比较,进一步证实了PSTD-polysia,PSTD-TriSia(DP3)和PSTD-polysia。基于PSTD-CMP-Sia之间的相互作用,PSTD-polysia,PBR-NCAM和PSTD-PBR,这些发现提供了对polySia-NCAM多聚唾液酸化的分子机制的更深入的理解,因此,通过靶向两种聚唾液酸转移酶,为翻译药理学应用和开发提供了新的视角。
    Polysialic acid (polySia) is an unusual glycan that posttranslational modifies neural cell adhesion molecule (NCAM) proteins in mammalian cells. The up-regulated expression of polySia-NCAM is associated with tumor progression in many metastatic human cancers and in neurocognitive processes. Two members of the ST8Sia family of α2,8-polysialyltransferases (polySTs), ST8Sia II (STX) and ST8Sia IV (PST) both catalyze synthesis of polySia when activated cytidine monophosphate(CMP)-Sialic acid (CMP-Sia) is translocate into the lumen of the Golgi apparatus. Two key polybasic domains in the polySTs, the polybasic region (PBR) and the polysialyltransferase domain (PSTD) areessential forpolysialylation of the NCAM proteins. However, the precise molecular details to describe the interactions required for polysialylation remain unknown. In this study, we hypothesize that PSTD interacts with both CMP-Sia and polySia to catalyze polysialylation of the NCAM proteins. To test this hypothesis, we synthesized a 35-amino acid-PSTD peptide derived from the ST8Sia IV gene sequence and used it to study its interaction with CMP-Sia, and polySia. Our results showed for the PSTD-CMP-Sia interaction,the largest chemical-shift perturbations (CSP) were in amino acid residues V251 to A254 in the short H1 helix, located near the N-terminus of PSTD. However, larger CSP values for the PSTD-polySia interaction were observed in amino acid residues R259 to T270 in the long H2 helix. These differences suggest that CMP-Sia preferentially binds to the domain between the short H1 helix and the longer H2 helix. In contrast, polySia was principally bound to the long H2 helix of PSTD. For the PSTD-polySia interaction, a significant decrease in peak intensity was observed in the 20 amino acid residues located between the N-and C-termini of the long H2 helix in PSTD, suggesting a slower motion in these residues when polySia bound to PSTD. Specific features of the interactions between PSTD-CMP-Sia, and PSTD-polySia were further confirmed by comparing their 800 MHz-derived HSQC spectra with that of PSTD-Sia, PSTD-TriSia (DP 3) and PSTD-polySia. Based on the interactions between PSTD-CMP-Sia, PSTD-polySia, PBR-NCAM and PSTD-PBR, these findingsprovide a greater understanding of the molecular mechanisms underlying polySia-NCAM polysialylation, and thus provides a new perspective for translational pharmacological applications and development by targeting the two polysialyltransferases.
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