The response to nutritional labels: Evidence from a quasi-experiment

This paper evaluates a UK policy that aimed to improve dietary information provision by introducing nutrition labelling on retailers’ store-brand products. Exploiting the differential timing of the introduction of Front-of-Pack nutrition labels as a quasi-experiment, our findings suggest that labelling led to a reduction in the quantity purchased of labelled store-brand foods, and an improvement in their nutritional composition. More specifically, we find that households reduced the total monthly calories from labelled store-brand foods by 588 kcal, saturated fats by 14 g, sugars by 7 g, and sodium by 0.8 mg.     

Synthesis,bioconjugation and stability studies of [18F]ethenesulfonyl fluoride

Fluorine‐18 labelled prosthetic groups (PGs) are often necessary for radiolabelling sensitive biological molecules such as peptides and proteins. Several shortcomings, however, often diminish the final yield of radiotracer. In an attempt to provide higher yielding and operationally efficient tools for radiolabelling biological molecules, we describe herein the first radiochemical synthesis of [¹⁸F]ethenesulfonyl fluoride ([¹⁸F]ESF) and its Michael conjugation with amino acids and proteins. The synthesis of [¹⁸F]ESF was optimised using a microfluidic reactor under both carrier‐added (c.a.) and no‐carrier‐added (n.c.a.) conditions, affording, in a straightforward procedure, 30‐50% radiochemical yield (RCY) for c.a. [¹⁸F]ESF and 60‐70% RCY for n.c.a. [¹⁸F]ESF. The conjugation reactions were performed at room temperature using 10 mg/mL precursor in aqueous/organic solvent mixtures for 15 min. The radiochemical stability of the final conjugates was evaluated in injectable formulation and rat serum, and resulted strongly substrate dependent and generally poor in rat serum. Therefore, in this work we have optimised a straightforward synthesis of [¹⁸F]ESF and its Michael conjugation with model compounds, without requiring chromatographic purification. However, given the general low stability of the final products, further studies will be required for improving conjugate stability, before assessing the use of this PG for PET imaging.     

The vial kit formulation for preparation of no‐carrier‐added 131I‐MIBG

We have developed a new set of lyophilized kits, composed of 3 different kits, for the instant preparation of no‐carrier‐added ¹³¹I‐MIBG in the clinic. We here discussed the formulation of the kits, optimization of radiolabelling, quality control of radiolabeled ¹³¹I‐MIBG, and studies of animal biodistribution. The no‐carrier‐added (nca) ¹³¹I‐MIBG injection could be prepared within 30 minutes in the clinic with the help of the lyophilized kits. The radiochemical purity and specific activity (SA) could achieve above 98% and 6700 MBq/mg, respectively.     

Comparison of incremental concentrations of micron-sized superparamagnetic iron oxide for labelling articular cartilage derived chondroprogenitors

IntroductionIn vivo tracking of labelled cells can provide valuable information about cellular behavior in the microenvironment, migration and contribution of transplanted cells toward tissue regeneration. Articular cartilage derived chondroprogenitors (CPs) show promise as a candidate for cell-based therapy as they have been classified as mesenchymal stem cells with inherent chondrogenic potential. Iron oxide labelling is known to withstand harsh processing techniques known to be associated with staining of osteochondral specimens.Aim and methodsThe aim of our study was to investigate the feasibility of labelling CPs with micron-sized super paramagnetic iron oxide (M-SPIO) particles and to study the effects of this approach on the labelling efficiency, viability, maintenance of phenotype and potential for differentiation. Human CPs were isolated using fibronectin adhesion assay, passage 2 cells were labelled using three concentrations of M-SPIO (12.75 μg/ml, 25.5 μg/ml and 38.25 μg/ml). At sub confluence, cells were assessed for a) iron uptake by Prussian blue stain and colorimetry b) viability using 7-amino actinomycin D, c) MSC marker expression by flow cytometric analysis and d) trilineage differentiation potential.Results and conclusionIron uptake was higher with increase in M-SPIO concentration whereas CD73, CD90 marker expression significantly decreased and chondrogenic potential appreciably reduced with increase in M-SPIO concentration. In conclusion, 12.75 μg/ml M-SPIO can successfully label human articular cartilage derived chondroprogenitors with minimal effect on cellular viability, MSC marker expression and potential for differentiation.     

应用牵张成骨术整复腭裂骨质缺损的组织学研究

目的 :观察牵张成骨术整复腭裂过程中 ,新骨组织形成与改建活动的特点 ,探讨新骨生成的规律。方法 :家猫 14只为实验对象。其中 12只建立人工腭裂实验模型。实验组 (动物 10只 ) :以 0 .4mm× 2次 /d的速度与频率牵张整复腭裂缺损。于术后固定期 2、4、6、8及 12周 ,观察期结束前 6d ,各对 2只动物肌注四环素标记 ( 30mg/kg)。 6d后取标本 ,切片行荧光显微镜及组织学观察 ,并与实验对照组及空白对照组 (动物各2只 )结果对比。结果 :实验组标本牵张区新骨组织均为膜内成骨 ,由中央向外分为胶原纤维区、新骨形成区及改建成熟区 ;随时间发展 ,新生骨逐渐取代纤维组织并改建成熟。软组织也得到相应伸展。对照组裂隙无自行修复。结论 :应用牵张成骨术矫治腭裂骨质缺损 ,以原位产生新骨 ,增加骨量的方式推移骨运送盘封闭腭裂裂隙。在良好固定条件下 ,新骨形成与改建活跃 ,最终整复腭裂骨质缺损并适应功能需要     

快速上颌扩弓保持与复发的动物实验研究

目的 :研究腭中缝扩张 (Sd Sd)、牙槽突倾斜和弯曲 (At b At b)、牙齿移位 (Td Td)、牙齿倾斜 (Tt Tt)在快速扩弓、保持和复发结束时的比例变化及该变化与扩弓稳定性的关系。方法 :选择 6周龄SD雄性大鼠 2 4只 ,随机分为 3组 ,每组均设实验组 6只和对照组 2只 ,实验组经过快速扩弓期 ( 1周 )、保持期( 4周 )、复发期 ( 4周 ) ,对照组不作扩弓处理 ,制作四环素荧光标记不脱钙磨片 ,在荧光显微镜下观察并将图像输入计算机分析仪测量腭中缝的宽度 (SW )、磨牙颊尖区增宽的量 (即扩弓量M M )和磨牙牙槽嵴增宽的量 (RM RM) ,从而利用公式计算出 4个部分的比例。结果 :磨牙扩弓量 (M M )在扩弓结束时、保持结束时、复发结束时 4部分 [(Sd Sd) :(Tt Tt) :(At b At b) :(Td Td) ]的比例变化为 :45 .2 % ( 0 .47mm ):17.8% ( 0 .19mm) :2 5 .7% ( 0 .2 7mm) :11.4% ( 0 .12mm ) -5 2 .3 % ( 0 .47mm) :15 .5 % ( 0 .14mm ):18.9% ( 0 .17mm) :13 .3 % ( 0 .12mm) -61.8% ( 0 .3 4mm) :18.2 % ( 0 .10mm) :1.8% ( 0 .0 1mm) :18.2 % ( 0 .10mm )。结论 :腭中缝扩张 (Sd Sd)是快速上颌扩弓中最重要的部分 ,其稳定性关系到扩弓的成败。     

蚕丝蛋白膜法在粪便隐血试验中的应用评价

目的 通过几种隐血试验方法的比较，了解蚕丝蛋白膜法检测大便隐血试验方法的可靠性。方法 以世界卫生组织和世界胃肠镜检查协会推荐作为粪便隐血试验较为确认的胶体金免疫法为标准，同时用蚕丝蛋白膜法（自制）、免疫法（便隐血胶体金）、化学法（纸片法和联苯胺法）进行灵敏度、特异性、抗干扰和盲测试验。结果 蚕丝蛋白膜法和便隐血胶体金法的灵敏度为0．1μgHb／ml。特异性：只与人血红蛋白反应，与其它动物血不反应；与胶体金法盲测结果无明显差异（P〉0.05），与化学法（纸片法和联苯胺法）相比有非常显著性差异（P〈0．01）。90例经便隐血胶体金法确证为阳性的标本，蚕丝蛋白膜法90例结果全部呈阳性，符合率100％。结论 经临床应用结果证明，此法简便快速，灵敏度高，特异性强，适合临床应用。