A 2-D/3-D model-based method to quantify the complexity of microvasculature imaged by in vivo multiphoton microscopy

This paper presents model-based information-theoretic methods to quantify the complexity of tumor microvasculature, taking into account shape, textural, and structural irregularities. The proposed techniques are completely automated, and are applicable to optical slices (3-D) or projection images (2-D). Improvements upon the prior literature include: (i) measuring local (vessel segment) as well as global (entire image) vascular complexity without requiring explicit segmentation or tracing; (ii) focusing on the vessel boundaries in the complexity estimate; and (iii) added robustness to image artifacts common to tumor microvasculature images. Vessels are modeled using a family of super-Gaussian functions that are based on the superquadric modeling primitive common in computer vision. The superquadric generalizes a simple ellipsoid by including shape parameters that allow it to approximate a cylinder with elliptical cross-sections (generalized cylinder). The super-Gaussian is obtained by composing a superquadric with an exponential function giving a form that is similar to a standard Gaussian function but with the ability to produce level sets that approximate generalized cylinders. Importantly, the super-Gaussian is continuous and differentiable so it can be fit to image data using robust non-linear regression. This fitting enables quantification of the intrinsic complexity of vessel data vis-a-vis the super-Gaussian model within a minimum message length (MML) framework. The resulting measures are expressed in units of information (bits). Synthetic and real-data examples are provided to illustrate the proposed measures.     

二维斑点追踪超声心动图左房软件及左室软件测量左房机械形变功能的一致性分析

目的 评估TomTec工作站左房及左室两种斑点追踪超声心动图软件测量左房整体纵向应变及应变率的一致性分析。方法 收集64个受检者的临床资料及超声心动图图像,两名受规范化培训医师分别应用2D-STE左房及左室软件获得左房整体纵向收缩期应变(Sct)、通道期应变(Scd)、左房储存期应变(Sr=Sct+Scd)及收缩期应变率(SRct)、通道期应变率(SRcd)、储存期应变率(SRr)。通过比较测量者内和测量者间获得的左房应变及应变率测值以评估两种软件测量的一致性有无差异。结果 （1）两种软件测量者内和测量者间的测值存在差异,仅左室软件测量者间SRcd差异有统计学意义（P=0.01）;（2）Bland-Altman一致性检验提示两种软件有较好的一致性,但左房软件测值较左室软件偏倚小,一致性区间较左室软件范围小;（3）测量者信度分析,左房软件测值较左室软件一致性好。结论 二维斑点追踪超声心动图左房专用软件较左室软件测值偏倚小,一致性范围稳定,测量者的重测信度优秀,值得在左房功能分析中推广应用。     

Smallpox vaccine,ACAM2000: Sites and duration of viral shedding and effect of povidone iodine on scarification site shedding and immune response

The U.S. Department of Defense vaccinates personnel deployed to high-risk areas with the vaccinia virus (VACV)-based smallpox vaccine. Autoinoculations and secondary and tertiary transmissions due to VACV shedding from the vaccination site continue to occur despite education of vaccinees on the risks of such infections. The objectives of this study were to investigate, in naïve smallpox vaccinees, (a) whether the vaccination site can remain contagious after the scab separates and (b) whether the application of povidone iodine ointment (PIO) to the vaccination site inactivates VACV without affecting the immune response. These objectives were tested in 60 individuals scheduled to receive smallpox vaccine. Thirty individuals (control) did not receive PIO; 30 subjects (treatment) received PIO starting on post-vaccination day 7. Counter to current dogma, this study showed that VACV continues to shed from the vaccination site after the scab separates. Overall viral shedding levels in the PIO group were significantly lower than those in the control group (p = 0.0045), and PIO significantly reduced the duration of viral shedding (median duration 14.5 days and 21 days in the PIO and control groups, respectively; p = 0.0444). At least 10% of control subjects continued to shed VACV at day 28, and 3.4% continued to shed the virus at day 42. PIO reduced the proportion of subjects shedding virus from the vaccination site from day 8 until days 21–23 compared with control subjects. Groups did not differ significantly in the proportion of subjects mounting an immune response, as measured by neutralizing antibodies, IgM, IgG, and interferon-gamma enzyme-linked immunospot assay. When applied to the vaccination site starting on day 7, PIO reduced viral shedding without altering the immune response. The use of PIO in addition to a semipermeable dressing may reduce the rates of autoinoculation and contact transmission originating from the vaccination site in smallpox-vaccinated individuals.     

我国眼视光学近五年十大研究进展

中华医学会眼科学分会眼视光学组通过学组委员投票的方式遴选出代表我国近5年(2009至2013年)眼视光学临床和基础研究领域最突出的10项研究进展,主要集中于近视眼临床和基础研究、屈光手术和视觉质量研究、角膜接触镜的研发和临床应用、视觉认知和低视力康复研究的开展及临床推广、新型技术和检查设备的应用等5个方面.这些研究在一定程度上代表了目前我国眼视光学在国际同领域的水平和影响力,部分研究成为我国眼视光学者在国际学术领域的标志性成果.     

Safety evaluation of metal exposure from commonly used moisturizing and skin-lightening creams in Nigeria

The concentrations of ten metals (Cd, Pb, Ni, Cr, Cu, Co, Fe, Mn, Zn and Al) were measured in some commonly used moisturizing and skin-lightening creams in Nigeria with a view to providing information on the risk of exposure to metals from the use of these products. The metal concentrations in these products were measured by atomic absorption spectrometry after acid digestion of the samples. The measured concentrations of metals in the skin moisturizing creams ranged from <0.15 to 6.3 μg/g Cd, <0.02 to 17.5 μg/g Cu, 2.25 to 6.25 μg/g Cr, <0.25 to 124.3 μg/g Al, 0.2 to 7.3 μg/g Pb, <0.03 to 10.7 μg/g Ni, 17.3 to 372.0 μg/g Zn, <0.02 to 1.0 μg/g Co, 17.75 to 28.8 μg/g Mn, <0.1 to 89.8 μg/g Fe while the concentrations of metals in the skin-lightening products ranged from <0.15 to 16.5 μg/g Cd, <0.02 to 10.0 μg/g Cu, 4.25 to 8.0 μg/g Cr, <0.25 to 128.0 μg/g Al, 0.5 to 4.5 μg/g Pb, <0.03 to 1.65 μg/g Ni, 24.7 to 267.5 μg/g Zn, <0.02 to 2.5 μg/g for Co, 19.3 to 31.8 μg/g Mn, 9.5 to 211.63 μg/g Fe. In a significant number (>93%) of the samples investigated the concentrations of Pb, Cd, Ni and Co were below the specified limit, or the maximal limit for impurities in colour additives in cosmetics for external use. However, Cr was found at concentrations above the allergenic limit of 1 μg/g. The results also showed that skin-lightening creams contained higher concentrations of the studied metals than the moisturizing creams, except for Ni, which indicates that persons who uses skin-lightening creams in preference to moisturizing ones, are exposed to higher concentrations of metals.     

Estimating skin sensitization potency from a single dose LLNA

Skin sensitization is an important aspect of safety assessment. The mouse local lymph node assay (LLNA) developed in the 1990s is an in vivo test used for skin sensitization hazard identification and characterization. More recently a reduced version of the LLNA (rLLNA) has been developed as a means of identifying, but not quantifying, sensitization hazard. The work presented here is aimed at enabling rLLNA data to be used to give quantitative potency information that can be used, inter alia, in modeling and read-across approaches to non-animal based potency estimation. A probit function has been derived enabling estimation of EC3 from a single dose. This has led to development of a modified version of the rLLNA, whereby as a general principle the SI value at 10%, or at a lower concentration if 10% is not testable, is used to calculate the EC3. This version of the rLLNA has been evaluated against a selection of chemicals for which full LLNA data are available, and has been shown to give EC3 values in good agreement with those derived from the full LLNA.     

Hydrogels in ophthalmic applications

More and more people worldwide are affected by severe eye diseases eventually leading to visual impairment or blindness. In most cases, the treatment involves the application of ophthalmic dosage forms such as eye drops, suspensions or ointments. Unfortunately, some of the therapeutic approaches have major shortcomings, especially in the treatment of the posterior segment of the eye, where many vision-threatening diseases originate. Therefore, research focuses on the development of new materials (e.g., for vitreous substitution) and more advanced drug delivery systems. Hydrogels are an extremely versatile class of materials with many potential applications in ophthalmology. They found widespread application as soft contact lenses, foldable intraocular lenses, in situ gelling formulations for ophthalmic drug delivery and ocular adhesives for wound repair; their use as vitreous substitutes and intravitreal drug delivery systems is currently under investigation. In this article, we review the different applications of hydrogels in ophthalmology with special emphasis placed on the used polymers and their suitability as ocular drug delivery systems.     

上海市中心城区某幼儿园一例肺结核患者密切接触者筛查情况分析

目的 分析上海市中心城区某幼儿园1例肺结核患者密切接触者筛查情况,为完善托幼机构结核病防控提供依据。方法 分别于2019年2月15日和2019年3月14日对2019年1月14日确诊的上海市中心城区某幼儿园1例肺结核教职工的128名密切接触者进行流行病学筛查,包括肺结核疑似症状筛查、结核分枝杆菌潜伏感染检测[γ干扰素释放试验(interferon-γ releaseassays,IGRA)]、胸部X线摄片或CT检查,以及痰涂片和痰培养;并对不同特征密切接触者(性别、卡介苗接种情况、有无疑似肺结核症状、近期呼吸系统疾病就诊史、暴露等级)的潜伏感染情况进行分析。结果 128名密切接触者中,幼儿107名(83.59%),教职工21名(16.41%)。疑似肺结核症状阳性率为5.47%(7/128),其中幼儿为5.61%(6/107),教职工为4.76%(1/21)。两次筛查中,共125名密接者(3名幼儿拒绝检测)进行了IGRA检测,阳性者11例(8.80%),包括幼儿4例(3.20%),教职工7例(5.60%)。肺结核的检出率为0.78%(1/128),总潜伏感染率为8.06%(10/124;排除1例确诊和3名未进行IGRA检测的幼儿),其中幼儿的潜伏感染率[2.91%(3/103)]明显低于教职工[33.33%(7/21)],差异有统计学意义(χ²=21.773,P=0.000)。7例潜伏感染教职工进行了3、6、12个月末的胸片随访,3例潜伏感染幼儿进行了3个月的预防性抗结核药品干预治疗;经1年随访观察均无续发结核病患者。单因素分析显示,接种卡介苗者的潜伏感染率[5.13%(6/117)]与未接种者(4/7)比较,差异有统计学意义(Fisher精确概率法,P=0.001);高暴露等级者的潜伏感染率[17.07%(7/41)]明显高于中暴露等级者 [3.61%(3/83)],差异有统计学意义(χ²=5.012,P=0.025)。结论 应加强托幼机构教职员工健康体检,积极行IGRA检测筛查结核病患者密切接触者,尤其是无卡介苗接种史和高暴露者。对结核分枝杆菌潜伏感染者行预防性服药或胸片随访对防止续发肺结核有重要意义。