Subclinical infections of cardiac implantable electronic devices: Insights into the host–bacteria dialog from blood and pocket tissue with pyrosequencing

While bacteria exist in CIED patients without clinical signs of infection, the underlying bacterial community structure and diversity in the bloodstream and pocket tissue of asymptomatic CIED patients remain unknown. In this study, we performed high-throughput 454 pyrosequencing of bacterial 16S rDNA of blood and pocket tissue from 54 asymptomatic CIED patients as well as blood from 30 normal individuals (normal controls). Firstly, we observed a significant increase of blood bacterial diversity in patients as compared with blood of normal subjects or patient tissues. We also found significant differences in 13 blood-associated bacterial genera between patients and normal subjects, and 14 bacteria genera between blood and tissues within patients. Secondly, we found that the serum levels of four inflammatory markers (CRP, IL-1β, IL-6, and MCP-1) in CIED patients were significantly higher than those in normal subjects. Thirdly, we found that there were significant correlations between 43 bacterial species and these inflammatory markers. Taken together, our results reveal a high diversity in the microbial community in CIED patients, and suggest the potential roles of multiple bacteria co-occurrence in the CIED subclinical infections.     

Non-classical mechanisms of steroid sensing in the ovary: Lessons from the bovine oxytocin model

Steroidogenic tissues such as the ovary, testes or adrenal glands are paradoxical in that they often indicate actions of steroid hormones within a dynamic range of ligand concentration in a high nanomolar or even micromolar level, i.e. at the natural concentrations existing within those organs. Yet ligand-activated nuclear steroid receptors act classically by direct interaction with DNA in the picomolar or low nanomolar range. Moreover, global genomic studies suggest that less than 40% of steroid-regulated genes involve classical responsive elements in gene promoter regions. The bovine oxytocin gene is a key element in the maternal recognition of pregnancy in ruminants and is regulated via an SF1 site in its proximal promoter. This gene is also regulated by steroids acting in a non-classical manner, involving nuclear receptors which do not interact directly with DNA. Dose-response relationships for these actions are in the high nanomolar range. Similar ‘steroid sensing’ mechanisms may prevail for other SF1-regulated genes and predict alternative pathways by which environmental endocrine disruptors might influence the functioning of steroid-producing organs and hence indirectly the steroid-dependent control of physiology and development.     

多层螺旋CT后处理技术对小儿气道异物的诊断价值

目的探讨多层螺旋CT后处理技术在小儿气道异物临床诊断中的应用价值。方法对我院39例疑似气道异物患儿行64排CT平扫后利用后处理技术重建图像资料,影像诊断为气道异物,并回访临床支气管镜下异物探查结果进行分析讨论。结果39例患儿中提供异物吸入史的为36例,37例支气管镜下异物探查取出术结果证实为阳性,准确率达95%,2例误诊,误诊率为5%;其中2例出现阻塞性肺炎,右侧支气管21例,左侧支气管15例,支气管分叉处1例。结论根据患儿有无吸入史,结合多层螺旋CT后处理技术后重建图像,对气道异物诊断、定位及临床治疗和预后提供了重要价值。     

Platelets are efficient and protective depots for storage,distribution, and delivery of lysosomal enzyme in mice with Hurler Syndrome

Use of megakaryocytes/platelets for transgene expression may take advantage of their rapid turnover and protective storage in platelets and reduce the risk of activating oncogenes in hematopoietic stem and progenitor cells (HSCs). Here, we show that human megakaryocytic cells could overexpress the lysosomal enzyme, α-l-iduronidase (IDUA), which is deficient in patients with mucopolysaccharidosis type I (MPS I). Upon megakaryocytic differentiation, the amount of released enzyme increased rapidly and steadily by 30-fold. Using a murine MPS I model, we demonstrated that megakaryocyte/platelets were capable of producing, packaging, and storing large amounts of IDUA with proper catalytic activity, lysosomal trafficking, and receptor-mediated uptake. IDUA can be released directly into extracellular space or within microparticles during megakaryocyte maturation or platelet activation, while retaining the capacity for cross-correction in patient’s cells. Gene transfer into 1.7% of HSCs led to long-term normalization of plasma IDUA and preferential distribution of enzyme in liver and spleen with complete metabolic correction in MPS I mice. Detection of GFP (coexpressed with IDUA) in Kupffer cells and hepatocytes suggested liver delivery of platelet-derived IDUA possibly via the clearance pathway for senile platelets. These findings provide proof of concept that cells from megakaryocytic lineage and platelets are capable of generating and storing fully functional lysosomal enzymes and can also lead to efficient delivery of both the enzymes released into the circulation and those protected within platelets/microparticles. This study opens a door for use of the megakaryocytes/platelets as a depot for efficient production, delivery, and effective tissue distribution of lysosomal enzymes.The potential of therapeutic benefits from genetically modified hematopoietic stem cells (HSCs) has been supported in recent gene therapy clinical trials (1, 2). High transgene dosage or selective growth of genetically corrected HSCs appears to be necessary for achieving clinical efficacy. However, genotoxic risk caused by proviral integration-associated oncogenesis is directly concomitant with high numbers of integration events or clonal expansion (3, 4). New approaches are needed to balance the need for high transgene frequency while limiting the associated increased risk of oncogenesis.Platelets are anuclear, secretory particulate entities containing proteins stored in cytoplasmic granules that can be released upon activation (5). Healthy adults produce 2–5 × 10¹¹ platelets daily with a baseline activation rate of 1–5% (6). Use of megakaryocytes (MKs)/platelets for transgene expression may (i) take advantage of this immense cell mass and its rapid turnover (5–9 d); (ii) provide protective storage of the transgene product, which is essential for proteins sensitive to plasma pH; and (iii) continuously dispense proteins via degranulation from platelet activation at baseline (without detectable injury) and/or at sites of vascular injury. Highly efficient protein production and delivery could further reduce the need for high transgene frequency and the risk of activating oncogenes in HSCs and all their progeny. Although using platelets as a delivery system has been demonstrated for the expression of coagulation factors to treat inherited bleeding disorders in mice (7, 8), there has been no report of the feasibility of using MKs/platelets for the generation of nonhematologic proteins.Lysosomal storage diseases (LSDs) are a group of inherited disorders, often affecting multiple organs including the liver and spleen, with a cumulative incidence of 1 in 5,000–7,000 live births (9). Overexpressing lysosomal enzymes in platelets not only can provide the protection of pH-sensitive enzymes and continuous enzyme release via low physiological levels of platelet activation but may also offer the benefit of on-target delivery of platelet-derived enzymes to spleen and liver in the process of platelet clearance (10). However, maintaining proper posttranslational modifications for appropriate lysosomal trafficking and intercellular lysosomal enzyme transfer is essential for metabolic cross correction in treating these multiorgan diseases (11). It is not known whether lysosomal enzymes generated from the MK/platelet lineage would be fully functional and capable of correcting lysosomal deficits in diseased cells.In this study, we used a mouse model of Hurler syndrome, which is the severe form of mucopolysaccharidosis type I (MPS I), one of most common LSDs. It is caused by the deficiency of α-l-iduronidase (IDUA) and consequent accumulation of glycosaminoglycans (GAGs) (12, 13). We show that MKs are capable of producing large amounts of IDUA with proper catalytic function, lysosomal trafficking and receptor-mediated uptake, which could be sorted to and stored within platelets. The IDUA can be released directly into the extracellular space or within microparticles (MPs) during MK maturation or platelet activation, while retaining its ability to cross-correct cells derived from patients with MPS I.     

沙美特罗／丙酸氟替卡松对支气管哮喘患者转化生长因子β1／Smad通路的影响

目的观察沙美特罗／N酸氟替卡松对中重度持续支气管哮喘（简称哮喘）患者转化生长因子p1（transforminggrowthfactor—β1,TGF-β1）／Smad通路的影响。方法中重度持续哮喘患者30例,对照组20例。哮喘组给予规律吸入沙美特罗／N酸氟替卡松50／250／xg,2次／d,持续6个月。酶联免疫吸附试验（ELISA法）定量测血清TGF-β1、Smad2表达,宝石能谱高分辨率CT（HRCT）扫描测量气道壁厚度／气道外径（T／D）、气道壁面积占气道总面积百分比（WA％）评估气道重塑程度。结果哮喘组（治疗前）血清TGF-β1（301．5±27．3）ng／L、Smad2（1182．1±50．6）ng／L与对照组TGF—β1（55．2±12．8）ng／L、Smad2（796．4±56．2）ng／L比较差异有统计学意义（t=8．52,t=5．90,P值均〈0.05）,哮喘组（治疗后）TGF-β1,（96．1±25．6）ng／L、Smad2（853．4±49．7）ng／L与哮喘组（治疗前）比较差异具有统计学意义（t=7．21,t=3．13,P值均〈O．05）,哮喘组（治疗后）血清Smad2与对照组比较差异无统计学意义（t=0．24,P〉o．05）;哮喘组（治疗前）T／D（23．66士4．06）％较对照组（19．79士3．37）％增加,差异有统计学意义（t=3．45,P〈O．05）,哮喘组（治疗前）wA％（69．24±6．03）‰值与对照组（51．67±4．55）％比较差异有统计学意义（t=3．77,P〈O．05）。规律吸入沙美特罗／丙酸氟替卡松6个月后,哮喘组（治疗后）T／D（20,43±3．00）％、WA％（58．40±3．85）％下降,与哮喘组（冶疗前）比较差异有统计学意义（t=2．96,t=3．05．P值均〈0．05）,哮喘组（治疗后）T／D与对照组比较差异无统计学意义（t=0．95,P〉0．05）,气道重塑减轻。结论哮喘患者气道重塑伴随血TGF-β1、Smad2蛋白的表达增加,规律吸入沙美特罗j丙酸氟替卡松可以通过减少血清TGF-β1、Smad2蛋白的表达,从而减轻哮喘患者气道重塑。调节TGF-β1／Smad通路可能是治疗哮喘气道重塑的新策略。     

基于人工神经网络模型的鼻咽癌VMAT计划质量控制方法

目的训练放疗计划个体化三维剂量预测模型,并使用该模型建立计划质量控制方法。方法回顾性分析99例已临床实施的早期鼻咽癌同步加量容积旋转调强放疗(VMAT)计划,提取7个几何特征,包括各危及器官(OARs)到PTV、加量靶区和外轮廓的最小距离,及4个坐标位置关系特征。训练(89例)并验证(10例)基于人工神经网络(ANN)的三维剂量分布预测模型;然后基于该预测模型建立放疗计划质量控制方法。以各危及器官剂量学参数D2%、D25%、D50%、D75%和平均剂量(MD)为质量控制指标,通过标准为人工计划和预测剂量差别≤10%。采用由低年资物理师设计的10例计划,对该质量控制方法进行测试。结果18个头颈部OARs的主要剂量学指标,预测剂量与专家计划结果差异无统计学意义。剂量预测结果与专家计划相比,D2%、D25%、D50%、D75%和平均剂量(MD)的差别均控制在1.2 Gy以内。由低年资物理师设计的10例计划均达到常规临床剂量限值的要求,而利用建立的质量控制方法检出1例计划的脊髓、脊髓危及器官的计划体积(PRV)、脑干和脑干PRV剂量限制有待改善。根据模型预测值重新优化计划后,脊髓和脑干D2%分别降低了8.4和5.8 Gy。结论提出了一种简单易行的放疗计划质量控制方法,能克服统一性剂量限值未考虑患者特异性的缺陷,可提高个体化计划质量和稳定性。     

The J-curve relationship between diastolic pressure and coronary collateral circulation in patients with single chronic total occlusion

Background

In our previous study, we had shown that high diastolic blood pressure (DBP) was positively related to well-developed coronary collateral circulation (CCC). This study sought to find out the more precise relationship between DBP and CCC.

Methods and results

To investigate this, we conducted a study of 671 patients with single chronic total occlusion of coronary artery. The DBP of the patients was divided into six groups: ≤65 mmHg, >65–≤75 mmHg, >75–≤85 mmHg, >85–≤95 mmHg, >95–≤105 mmHg, >105 mmHg). The extent of CCC was graded as poorly-developed or well-developed collaterals according to Rentrop classification. There was a J-curve relationship between the level of DBP and the incidence of poorly-developed collaterals.

Conclusion

The relationship between DBP and CCC is similar to the J-curve relationship between DBP and cardiovascular risk. The influence of DBP on the development of CCC may be one of the pathophysiologic mechanisms of the J-curve phenomenon relating DBP to cardiovascular risk.     

Codelivery of Adriamycin and P-gp Inhibitor Quercetin Using PEGylated Liposomes to Overcome Cancer Drug Resistance

Transmembrane protein P-gp's overexpression at the drug-resistant cell membrane is the most important characteristic of multidrug resistance (MDR). Quercetin (QUE) can effectively suppress the function of P-gp to reverse MDR. This study uses QUE as the P-gp inhibitor andfilm-ultrasound technique with ammonium sulfate transmembrane gradient method to prepare long-circulating liposomes simultaneously encapsulating QUE and Adriamycin (doxorubicin) (AMD/DOX). The optimal conditions for the preparation of AMD_QUE_long-circulating liposomes (SLs) are as follows: hydrogenated soybean phospholipids (HSPC):cholesterol:DSPE-PEG 2000 = 73.07:24.36:2.57 mol/mol, QUE:HSPC = 1:20 mol/mol, AMD:HSPC = 1:7.9 w/w (NH₄₎₂SO₄ 0.15 mol/L, drug loaded (AMD) at 55°C for 25 min). The average encapsulation efficiency of AMD and QUE was 97.49% and 95.50%, respectively. The average particle size is 85 nm (n = 3), and the average zeta potential is ?14.9 mV. First, the pharmacokinetic study proved that codelivery liposomes enveloping QUE and AMD (AMD_QUE_SL) can obviously increase the blood concentration of AMD (C_max: 140.50 ± 32.37 μg/mL) and extend the half-life period of AMD in plasma (t_1/2:14.02 ± 1.54 h). Second, AMD_QUE_SL can obviously enhance the cell toxicity to AMD-resistant cell strains (HL-6/ADR and MCF-7/ADR), and the reverse effects on the resistance of HL-6/ADR and MCF-7/ADR is increased to 4.81-fold and 3.21-fold, respectively. Third, according to the in vivo pharmacodynamic study, the relative tumor volume and relative tumor growth of the AMD_QUE_SL group were the lowest. The inhibition rate of tumor growth of this group was the highest. It can be concluded that AMD_QUE_SL can effectively reverse MDR, lower cardiac toxicity of AMD in clinical treatment, and improve the clinical treatment effect of AMD.