Digital surface scanning in flap perfusion

Monitoring vascular perfusion of transferred tissue is essential in reconstructive surgery to recognize early flap failure. The aim of this study was to evaluate the ability of a digital surface scanner to detect vascular perfusion disorders through the monitoring of skin colour changes. A total of 160 surface scans of the forearm skin were performed with a TRIOS 3D scanner. Vascular compromise was simulated at different time-points by intermittent occlusion of the blood supply to the forearm skin (first the arterial blood supply and then the venous blood supply). Skin colour changes were examined according to the hue, saturation, and value colour scale. Colour differences were analysed with a paired t-test. Significant differences were observed between the colour of the normal skin and that of the vascular compromised skin (P < 0.01). The surface scanner could distinguish between arterial occlusion and venous congestion (P < 0.01). A digital surface scan is an objective, non-invasive tool to detect early vascular perfusion disorders of the skin.     

Differentiating ictal/subclinical spikes and waves in childhood absence epilepsy by spectral and network analyses: A pilot study

ObjectiveChildhood absence epilepsy (CAE) is a disease with distinct seizure semiology and electroencephalographic (EEG) features. Differentiating ictal and subclinical generalized spikes and waves discharges (GSWDs) in the EEG is challenging, since they appear to be identical upon visual inspection. Here, spectral and functional connectivity (FC) analyses were applied to routine EEG data of CAE patients, to differentiate ictal and subclinical GSWDs.MethodsTwelve CAE patients with both ictal and subclinical GSWDs were retrospectively selected for this study. The selected EEG epochs were subjected to frequency analysis in the range of 1–30 Hz. Further, FC analysis based on the imaginary part of coherency was used to determine sensor level networks.ResultsDelta, alpha and beta band frequencies during ictal GSWDs showed significantly higher power compared to subclinical GSWDs. FC showed significant network differences for all frequency bands, demonstrating weaker connectivity between channels during ictal GSWDs.ConclusionUsing spectral and FC analyses significant differences between ictal and subclinical GSWDs in CAE patients were detected, suggesting that these features could be used for machine learning classification purposes to improve EEG monitoring.SignificanceIdentifying differences between ictal and subclinical GSWDs using routine EEG, may improve understanding of this syndrome and the management of patients with CAE.     

基于《医学六要》补肝汤辨证加味治疗腰椎间盘突出症回顾分析

目的:分析基于明代医家张三锡《医学六要》补肝汤辨证加味在腰椎间盘突出症中的治疗价值,以此对《医学六要》补肝思想进行继承创新。方法:对湖南省中医药研究院附属医院、湘潭市中医医院、北京中医药大学深圳医院2008年8月—2019年12月采取张三锡补肝汤辨证加味治疗的9741例腰椎间盘突出症患者,进行回顾性分析。结果:优3791例,良3740例,可1228例,差982例,总有效率达89.92%。各疾病分型及中医证型疗效情况如下。①膨出型腰椎间盘突出症的临床疗效最好,其次为中央突出型,脱出游离型疗效相对最差;②突出物在a域以内者临床疗效最好、其次为在b域以内者,突出物达到d域者疗效相对最差;③以寒湿型和血瘀型的临床疗效最好,不在《中医病证诊断疗效标准》中列出的其他型疗效相对最差;④以单纯L5~S1为责任节段的临床疗效最好,双节段或多节段椎间盘突出者疗效相对最差;⑤以单纯出现下肢症状和(或)体征者临床疗效最好、其次为单纯腰部出现症状和(或)体征,腰部和腿部同时出现症状和(或)体征者疗效相对最差;⑥病程以≤7天者疗效最好,≥3年者疗效相对最差。基于《医学六要》补肝汤辨证加味在腰椎间盘突出症的治疗应用上安全有效。结论:基于《医学六要》补肝汤辨证加味可用于指导腰椎间盘突出症的临床治疗,应对该补肝思想进行深入研究和继承创新。     

基因组拷贝数变异测序与染色体核型分析在胎儿遗传学诊断中的比较

目的比较基因组拷贝数变异测序(CNV-seq)技术和染色体核型分析和在产前胎儿遗传学诊断中的应用价值。方法收集来我院有产前诊断指征进行羊水穿刺的259例孕妇,取材后,送检染色体核型分析和CNV-seq,比较两种方法在产前诊断中的优缺点。结果259例标本中,共诊断异常染色体核型及微缺失微重复23例,总阳性诊断率8.88%(23/259),CNV-seq结果显示,共有22例染色体拷贝数异常(12例三体+9例微缺失微重复+1例三倍体),检出率为8.49%;染色体核型分析结果显示为:17例染色体异常(12例三体+3例结构异常+1例嵌合型+1例三倍体),检出率为6.56%。此外还检出染色体多态7例。结论CNV-seq与染色体核型分析对于染色体非整倍体的检测效力一致,CNV-seq能检测染色体微缺失微重复,染色体核型分析则能诊断出三体具体核型,在怀疑性染色体异常时,建议行两者联合检测。     

Risk-based cost-benefit analysis of alternative vaccines against COVID-19 in Brazil: Coronavac vs. Astrazeneca vs. Pfizer

We propose a probabilistic model to quantify the cost-benefit of mass Vaccination Scenarios (VSs) against COVID-19. Through this approach, we conduct a six-month simulation, from August 31st, 2021 to March 3rd, 2022, of nine VSs, i.e., the three primary vaccine brands in Brazil (CoronaVac, AstraZeneca and Pfizer), each with three different vaccination rates (2nd doses per week). Since each vaccine has different individual-level effectiveness, we measure the population-level benefit as the probability of reaching herd immunity (HI). We quantify and categorize the cost-benefit of VSs through risk graphs that show: (i) monetary cost vs. probability of reaching HI; and (ii) number of new deaths vs. probability of reaching HI. Results show that AstraZeneca has the best cost-benefit when prioritizing acquisition costs, while Pfizer is the most cost-beneficial when prioritizing the number of deaths. This work provides helpful information that can aid public health authorities in Brazil to better plan VSs. Furthermore, our approach is not restricted to Brazil, the COVID-19 pandemic, or the mentioned vaccine brands. Indeed, the method is flexible so that this study can be a valuable reference for future cost-benefit analyses in other countries and pandemics, especially in the early stages of vaccination, when data is scarce and uncertainty is high.     

Vaccine effectiveness against onward transmission of SARS-CoV2-infection by variant of concern and time since vaccination,Belgian contact tracing, 2021

BackgroundDuring the first half of 2021, we observed high vaccine effectiveness (VE) against SARS-CoV2-infection. The replacement of the alpha-‘variant of concern’ (VOC) by the delta-VOC and uncertainty about the time course of immunity called for a re-assessment.MethodsWe estimated VE against transmission of infection (VET) from Belgian contact tracing data for high-risk exposure contacts between 26/01/2021 and 14/12/2021 by susceptibility (VEs) and infectiousness of breakthrough cases (VEi) for a complete schedule of Ad26.COV2.S, ChAdOx1, BNT162b2, mRNA-1273 as well as infection-acquired and hybrid immunity. We used a multilevel Bayesian model and adjusted for personal characteristics (age, sex, household), background exposure, calendar week, VOC and time since immunity conferring-event.FindingsVET-estimates were higher for mRNA-vaccines, over 90%, compared to viral vector vaccines: 66% and 80% for Ad26COV2.S and ChAdOx1 respectively (Alpha, 0–50 days after vaccination). Delta was associated with a 40% increase in odds of transmission and a decrease of VEs (72–64%) and especially of VEi (71–46% for BNT162b2). Infection-acquired and hybrid immunity were less affected by Delta. Waning further reduced VET-estimates: from 81% to 63% for BNT162b2 (Delta, 150–200 days after vaccination). We observed lower initial VEi in the age group 65–84 years (32% vs 46% in the age group 45–64 years for BNT162b2) and faster waning. Hybrid immunity waned slower than vaccine-induced immunity.InterpretationVEi and VEs-estimates, while remaining significant, were reduced by Delta and waned over time. We observed faster waning in the oldest age group. We should seek to improve vaccine-induced protection in older persons and those vaccinated with viral-vector vaccines.     

医学影像纹理分析在软组织肿瘤中的研究进展

近年来凭借大数据及深度学习使得以纹理分析(Texture Analysis)为代表的影像组学迅猛发展。随着纹理分析方法及影像新技术的不断研发应用,近年来纹理分析被越来越多的应用于临床研究,为疾病、尤其是肿瘤的诊断、分级与疗效预测评估提供有价值的医学影像依据。本文总结了纹理分析的常用方法、流程,并对软组织肿瘤的研究现况进行调查,作一综述。