A novel device for the clearance and prevention of blockages within biomedical catheters

Biomedical catheters are commonly used to move fluids from one part of the body to another, or remove them from the body completely. In some instances, these catheters become occluded due to blood or other debris. Such occlusions may prove fatal or require re-operation with enormous costs and effects on the health-care system and the individual. We developed a model of occlusion in both a ventriculo-peritoneal shut system and en external ventricular drain. Having demonstrated that occlusions can be reliably generated in a manner that resembles the clinical situation we show that vibration can clear the blockages. Vibration in the 50–60 Hz range was able to maintain patency in the catheters or to clear the blockage when the catheter was completely occluded. In high concentrations of blood, 150 s of vibration applied every 30 min was able to maintain the patency of the catheter. Clinically, as the level of blood in the fluid decreases, the time intervals between vibration applications could be increased. We believe that vibration offers a safe, non-invasive method to maintain the patency of biomedical catheters.     

Active,continual fine tuning of convolutional neural networks for reducing annotation efforts

The splendid success of convolutional neural networks (CNNs) in computer vision is largely attributable to the availability of massive annotated datasets, such as ImageNet and Places. However, in medical imaging, it is challenging to create such large annotated datasets, as annotating medical images is not only tedious, laborious, and time consuming, but it also demands costly, specialty-oriented skills, which are not easily accessible. To dramatically reduce annotation cost, this paper presents a novel method to naturally integrate active learning and transfer learning (fine-tuning) into a single framework, which starts directly with a pre-trained CNN to seek “worthy” samples for annotation and gradually enhances the (fine-tuned) CNN via continual fine-tuning. We have evaluated our method using three distinct medical imaging applications, demonstrating that it can reduce annotation efforts by at least half compared with random selection.     

RICE: A method for quantitative mammographic image enhancement

We introduce Region of Interest Contrast Enhancement (RICE) to identify focal densities in mammograms. It aims to help radiologists: 1) enhancing the contrast of mammographic images; and 2) detecting regions of interest (such as focal densities) that are candidate masses potentially masked behind dense parenchyma. Cancer masking is an unsolved issue, particularly in breast density categories BI-RADS C and D. RICE suppresses normal breast parenchyma in order to highlight focal densities. Unlike methods that enhance mammograms by modifying the dynamic range of an image; RICE relies on the actual tissue composition of the breast. It segments Volumetric Breast Density (VBD) maps into smaller regions and then applies a recursive mechanism to estimate the ‘neighbourhood’ for each segment. The method then subtracts and updates the neighbourhood, or the encompassing tissue, from each piecewise constant component of the breast image. This not only enhances the appearance of a candidate mass but also helps in estimating the mass density. In extensive experiments, RICE enhances focal densities in all breast density types including the most challenging category BI-RADS D. Suitably adapted, RICE can be used as a precursor to any computer-aided diagnostics and detection system.     

Shp2 expression is upregulated in cervical cancer,and Shp2 contributes to cell growth and migration and reduces sensitivity to cisplatin in cervical cancer cells

Src homology phosphotyrosine phosphatase 2 (Shp2) has been found to be overexpressed in cervical cancer tissues. However, the influence of Shp2 on the biological behavior and sensitivity to cisplatin of cervical cancer cells remains unclear. We aimed to assess Shp2 expression in cervical tissues and cell lines and to detect the influence of Shp2 knockdown and overexpression on the biological behavior and sensitivity to cisplatin in cervical cancer cells. We found that Shp2 expression was significantly upregulated in cervical cancer tissues and cell lines, and Shp2 overexpression was associated with lymph node metastasis and a high human papillomavirus (HPV) DNA load. Shp2 knockdown inhibited cell growth and migration and enhanced sensitivity to cisplatin in the HeLa and SiHa cervical cancer cell lines. In contrast, Shp2 overexpression had the opposite effects. These tumor-promoting effects of Shp2 may be partly related to Akt signaling. In conclusion, Shp2 is involved in the occurrence and development of cervical cancer and may confer cisplatin resistance in cervical cancer. Shp2 blockade may be a new strategy for cervical cancer treatment.     

Risk stratification of coronary plaques using physiologic characteristics by CCTA: Focus on shear stress

The identification of factors determining whether a lesion progresses, destabilizes or becomes quiescent remains a challenge. Wall or endothelial shear stress (WSS or ESS, respectively), the frictional force acting on the lumen wall, is strongly associated with changes in the natural history of lesions. Several clinical intravascular imaging studies have shown a clear link between disturbed flow, typically characterized by low WSS, and plaque growth. In support of these studies, in-vitro experiments of shear stress have identified several mechanisms promoting atherosclerosis. More recently, the relationship between WSS and major adverse cardiac events has been explored. Improvements in coronary computed tomography angiography (CCTA) image resolution and quality has allowed for the calculation of WSS from CT. In this review, we provide an introduction to WSS, highlight important human and animal intravascular-based WSS studies, and discuss CT-based WSS studies to date. Finally, we discuss future directions of CCTA and WSS computation.     

T细胞参与心肌I/R损伤的研究进展

心肌I/R损伤（MI/RI）是治疗心肌梗死过程中的并发症之一,中性粒细胞、巨噬细胞等固有免疫细胞引起的炎性反应是导致MI/RI的重要原因。众多免疫细胞如何在MI/RI中发挥作用是目前研究的热点问题。近年来,越来越多的研究表明T细胞在MI/RI中发挥重要作用。本文将阐述T细胞在MI/RI中的作用及机制的研究进展,并分析目前存在的问题及发展方向。     

The SCN5A Mutation A1180V is Associated With Electrocardiographic Features of LQT3

Mutations of the SCN5A gene are associated with several arrhythmic syndromes including the Brugada syndrome, conduction disease, long QT syndrome type 3 (LQT3), atrial fibrillation, and dilated cardiomyopathy. We report LQT3 associated with an A1180V cardiac sodium channel mutation, previously associated with cardiac conduction block, and dilated cardiomyopathy in three generations of a Chinese family. Clinical, electrocardiographic (ECG), and echocardiographic examination was followed by direct sequencing of SCN5A and HERG to screen genomic DNA from blood samples. The proband presented with multiple syncopes from the age of 7 years and was found to share a mutation with two other members of his family. Continuous ECG monitoring after presentation showed prolonged QTc and biphasic T waves, multiple episodes of ventricular tachycardia and torsades de pointes. The other two mutation carriers showed ECG features of LQT3 without clinical symptoms. Transthoracic echocardiography showed normal cardiac structure in all three mutation carriers. This study shows LQT3 features associated with an A1180V cardiac sodium channel mutation, expanding the spectrum of phenotypes resulting from this mutation in which biophysical study has shown a persistent late Na⁺ current.     

基于多中心新生儿头颅MRI研究分娩方式对颅内出血发病风险的影响

目的基于MRI诊断分析不同分娩方式对新生儿颅内出血(intracranialhemorrhage,ICH)发病风险的影响。材料与方法回顾性收集6家三甲医院2011年1月至2016年10月出生14 d内行头颅MRI检查的新生儿3464例,排除临床资料不齐全、遗传代谢性疾病、先天性颅脑发育异常、产前颅内出血及MRI图像不能用于分析的病例。通过Logistic回归分析比较暴露于不同分娩方式下新生儿ICH的发病风险。结果纳入1976例新生儿进行分析,Logistic回归模型校正混杂因素后发现,与剖宫产相比,经阴道分娩的新生儿ICH的发病风险提高了4.27倍。进一步将阴道分娩分层,发现经产钳助产分娩的新生儿ICH的发病风险最高,为剖宫产的7.52倍。其中产钳助娩显著提高新生儿室管膜下-脑室内出血、蛛网膜下腔出血、硬膜下出血的发病风险。结论阴道分娩可能增加了新生儿ICH的发病风险,尤其是以产钳助产方式分娩的新生儿。