Dynamic Indicators That Impact the Outcomes of Thoracic Endovascular Aortic Repair in Complicated Type B Aortic Dissection

PurposeTo investigate dynamic variables obtained from retrospective computed tomography angiography for ability to predict thoracic endovascular aortic repair (TEVAR) outcomes in patients with complicated type B aortic dissection (cTBAD).Materials and MethodsSeventy-nine patients with cTBAD who received TEVAR from March 2009 to June 2018 were retrospectively enrolled. Relative true lumen area (r-TLA) was computed at the level of tracheal bifurcation every 5% of all R-R intervals. Parameters that reflect the state of intimal motion were evaluated, including difference between maximum and minimum r-TLA (D-TLA) and true lumen collapse. The endpoints comprised early (≤ 30 days) and late (> 30 days) outcomes after intervention.ResultsOverall early mortality rate was 13.9% (11/79), and early adverse events rate was 24.1% (19/79). Patients who received TEVAR within 2 days of symptom onset demonstrated the worst outcomes. A longer time of r-TLA < 25% in 1 cardiac cycle (P = .049) and larger D-TLA (P < .001) were correlated to an increased early death. In addition, D-TLA was an independent predictor of early mortality. Area under the curve of D-TLA was 0.849 (95% confidence interval 0.730–0.967) for predicting early mortality and 0.742 (95% CI 0.611–0.873) for predicting early adverse events. Survival and event-free survival rates during follow-up were decreased in the D-TLA > 21.5% group compared with the D-TLA ≤ 21.5% group (all P < .001).ConclusionsLarger D-TLA is correlated with worse postoperative outcomes and might be a crucial parameter for future risk stratification in patients with cTBAD.     

Conditional estimation of sensitivity and specificity from a phase 2 biomarker study allowing early termination for futility

Development of a disease screening biomarker involves several phases. In phase 2 its sensitivity and specificity is compared with established thresholds for minimally acceptable performance. Since we anticipate that most candidate markers will not prove to be useful and availability of specimens and funding is limited, early termination of a study is appropriate, if accumulating data indicate that the marker is inadequate. Yet, for markers that complete phase 2, we seek estimates of sensitivity and specificity to proceed with the design of subsequent phase 3 studies. We suggest early stopping criteria and estimation procedures that adjust for bias caused by the early termination option. An important aspect of our approach is to focus on properties of estimates conditional on reaching full study enrollment. We propose the conditional‐UMVUE and contrast it with other estimates, including naïve estimators, the well‐studied unconditional‐UMVUE and the mean and median Whitehead‐adjusted estimators. The conditional‐UMVUE appears to be a very good choice. Copyright © 2008 John Wiley & Sons, Ltd.     

经皮顺行交锁钉治疗股骨干骨折

目的:评价经皮顺行交锁钉治疗股骨干骨折的临床疗效.方法:对79例82处股骨干骨折采用髋部小切口经皮顺行交锁钉治疗,观察疗效.结果:75例(92%)获得了良好的解剖对位并达到一期愈合,6例(8%)迟缓愈合.另外,由于再次手术1例(1%)发生了深部感染.失血量较少(平均小于100 mL),切口平均长25 mm.1年后随访只有10%髋部疼痛.结论:与传统手术方式相比,经皮技术术中出血少、对周围组织创伤少,是一个安全又有效的方法.     

Analysis of signal-to-noise behavior in Cartesian continuous sampling sequences: predictions and experimental validation of opportunities for improved image SNR.

Image signal-to-noise ratio (SNR) limits many MRI applications. Here we propose a method to improve SNR based on continuous sampling (CS) during each TR without significant increases in acquisition time. The general concept of CS is defined here as sampling the NMR signal immediately after slice excitation including ramp times, both the dephase and rephase lobes, the phase-encoding (PE) gradient application, and the slice refocusing gradient. This study analyzes several cases of CS and demonstrates a specific case where sampling occurs during an isolated and balanced readout gradient in order to increase SNR in a rectilinear Cartesian sequence without significantly increasing overall acquisition time. The noise correlation consequences of rectilinear CS are mathematically derived and proven through simulation. The SNR improvement of up to approximately 40% measured in both phantom and asymptomatic human volunteer images is comparable to theoretical prediction of increased SNR proportional to the increase in the square root of the sampling time.     

Organization of amygdaloid projections to the mediodorsal thalamus and prefrontal cortex: a fluorescence retrograde transport study in the rat

Previous studies have shown that the amygdala projects to both the mediodorsal thalamic nucleus (MD) and its cortical projection area, the prefrontal cortex (PFC). In this investigation rats received injections of different fluorescent retrograde tracers (true blue and diamidino yellow) into MD and either the lateral, polar, or medial PFC in order to examine the relationship of amygdaloid neurons with cortical and/or thalamic projections. PFC injections labeled neurons in the basolateral (BL), basomedial (BM), ventral endopiriform (EnV), and rostral lateral nuclei as well as the periamygdaloid cortex (PAC) and the medial part of the amygdalohippocampal area (AHA). In BL, which contained the great majority of neurons projecting to PFC, most labeled cells were concentrated in particular parts of the nucleus and were topographically organized. The overwhelming majority of labeled neurons in BL were large pyramidal or piriform cells that correspond to class I neurons described in Golgi studies. Occasional small neurons with thin dendrites were also observed; these cells may be class II neurons. MD injections labeled numerous cells in the anterior division of the cortical nucleus, medial nucleus, and caudomedial part of the central nucleus. Moderate numbers of labeled cells were found in caudal portions of BM and PAC, whereas scattered cells were observed throughout the rest of the amygdala with the exception of the lateral nucleus. In BL and AHA many MD-projecting neurons were observed along nuclear boundaries and in the adjacent white matter. Neurons in BL, BM, and AHA usually had large elongated or irregular somata and two to four primary dendrites that branched sparingly. Other cells had smaller ovoid somata. The morphology and distribution of MD-projection cells in the basolateral amygdala indicate that they are primarily large class II neurons. Double-labeled amygdaloid neurons, labeled by both cortical and thalamic injections, were observed only in a small number of animals. Control experiments suggest that most of the double-labeled cells in these cases were artifacts caused by spread of the thalamic injectate into the third ventricle with subsequent uptake by fibers in the anterior commissure. Thus the findings of this study suggest that different neuronal populations in the amygdala project to the two poles of the MD-PFC system. In the basolateral amygdala class I neurons are the predominant cell type involved in PFC projections, whereas a subpopulation of class II neurons, hitherto thought to be primarily local-circuit neurons, project to MD.     

XX true hermaphroditism in Southern African Blacks: Exclusion of SRY sequences and uniparental disomy of the X chromosome

A molecular investigation of 16 Bantu-speaking Black XX true hermaphrodites was undertaken in an attempt to determine the cause of the disorder. Y-specific sequences, including sequences mapping to the sexdetermining region of the Y, were shown to be absent from lymphocyte tissue of all 16 patients tested. Y chromosome sequences were also absent from the ovarian and testicular components of both ovotestes of a single XX true hermaphrodite, thus excluding gonadal mosaicism involving Y chromosome sequences. Since there is evidence for Xp genes involved in testis determination/differentiation, uniparental disomy of the X chromosome was investigated in 14 XXTH families. Uniparental disomy was excluded in 12 of the 14 families, and isodisomy was excluded in the remaining two cases. © 1995 Wiley-Liss, Inc.     

论真气学说(一)——一般概念“气”的源流

“气”和“真气”是真气学说的基本概念，长期以来使用混乱。“气”是构成宇宙万物的精微物质，不能简单认为是某种元素，真气是相对于“气”的无形的功能，以质能说明两者的关系。研究“气”的重点是“真气”，真气的特性有非形态性、非常规性、超常性和系统性。作为一般概念“真气”的特性，涵盖中医学真气的特性。     

Dissected Aorta Repair Through Stent Implantation trial: Canadian results

Objectives

We describe the Canadian results of the Ascyrus Medical Dissection Stent (AMDS), a novel partially uncovered aortic arch hybrid graft implanted antegrade during hypothermic circulatory arrest to promote true lumen expansion and enhance aortic remodeling.

赤芍的抑菌作用及其防治慢性牙周炎的机制研究

目的 研究赤芍提取物对牙龈卟啉单胞菌（Porphyromonas gingivalis，P.g）、具核梭杆菌（Fusobacterium nucleatum，F.n）和伴放线聚集杆菌（Actinobacillus Actinomycetes，A.a）的抑菌作用，并通过网络药理学方法分析赤芍防治慢性牙周炎（chronic periodontitis，CP）的潜在分子机制和药理活性。方法 采用倍比稀释法测定赤芍提取物对3种牙周致病菌（P.g、F.n、A.a）的最低抑菌浓度（minimum inhibitory concentration，MIC）及最低杀菌浓度（minimal bactericidal concentration，MBC）。借助TCMSP数据库获取赤芍化学成分及作用靶点，通过Genecards等数据库获取CP疾病靶点，韦恩分析取交集。利用Cytoscape 3.7.2软件构建赤芍防治CP的“成分-靶点-疾病”网络，采用STRING数据库构建蛋白互作网络（Protein protein interaction network，PPI network），并进行基因本体（Gene Ontology，GO）和京都基因和基因组百科全书（Kyoto Encyclopedia of Genes and Genomes，KEGG）富集分析。结果 赤芍提取物对P.g、F.n、A.a的MIC分别为2.0、4.0、4.0 g/L，MBC分别为4.0、8.0、8.0 g/L。分析获得赤芍活性成分29个，CP疾病靶点2 132个，交集靶点89个。赤芍治疗CP的主要活性成分有黄芩苷、鞣花酸等，关键靶点包括白细胞介素-6（Interleukin-6，IL-6）等。GO富集分析得到蛋白质异构化活性等126个GO条目，KEGG富集分析得到丝裂原活化蛋白激酶（Mitogen-activated protein kinase，MAPK）等110条通路。结论 赤芍提取物对3种牙周致病菌均有不同程度的抑菌作用，初步阐述了赤芍的主要成分、作用靶点和相关通路在防治CP中具有重要的研究价值，为进一步深入临床研究提供实验依据和理论支持。