Fractal analysis of dental radiographs to detect periodontitis-induced trabecular changes

Background and Objective: The aim was to evaluate fractal analysis as a tool to quantitatively measure the impact of periodontal disease on surrounding bone. The diagnosis of periodontitis is based on information obtained from clinical and radiographic examinations. The current standard use of dental radiographs is visual inspection, often with no quantitative analysis. Fractal analysis can be used to examine trabecular bone patterns among periodontal patients. Material and Methods: Patients (n = 108) from the University of Southern California School of Dentistry were classified into three groups: healthy, moderate and severe periodontitis. A region of interest was selected from periapical radiographs. Image processing was applied to correct for lighting irregularity, and the box‐counting method was used to calculate a fractal dimension. ANOVA and ANCOVA were used to measure fractal dimension differences between all groups. Results: According to the statistical tests, significant differences in average fractal dimensions were measured between healthy and moderate periodontitis groups (p < 0.01) and between healthy and severe periodontitis groups (p < 0.001). Higher fractal dimensions were measured in healthy periodontal patients. Conclusion: Fractal analysis evidenced significant differences between patients affected and not affected by periodontitis. The box‐counting method quantitatively describes the severity of bone disease and can be used to improve current diagnostic techniques.     

Emergence and spread of Chlamydia trachomatis variant, Sweden

A variant of Chlamydia trachomatis that had escaped detection by commonly used systems was discovered in Sweden in 2006. In a nationwide study, we found that it is now prevalent across Sweden, irrespective of the detection system used. Genetic analysis by multilocus sequence typing identified a predominant variant, suggesting recent emergence.     

Evaluation of diagnostic scores with adjustment for covariates

Diagnostic tests yield measurements on very different types of scales. Quantitative scales may consist of non-negative integers, either unbounded or bounded, with a fixed number of different values, or they may consist of continuous or percentage values. Remembering a different threshold value for each diagnostic variable would be cumbersome, in particular if covariates have to be taken into account. As a convenient way to overcome such problems we propose to compute z-scores for all measurements. They will be adjusted for covariates so that any individual can be judged on any test result on one single scale with an appropriate standard normal quantile as threshold. Two issues need to be addressed: Selection of covariates in the regression model which delivers the adjustment and normality of the residuals. The first will be treated by cross-validation and the latter by applying an appropriate transformation. We apply this methodology to neuropsychological tests and adjust for age, length of education and sex. Normality of residuals is needed on the diagnostically relevant side only. This allows to use parametric transformations, which can be easily implemented, e.g. in database systems. Since we have measurements at baseline and at follow-up we also analyze change values in a similar manner. For ease of interpretation, we transform the resulting z-scores back to the original scale.     

Prognostic relevance of adding MRI data to WHO 2016 and cIMPACT‐NOW updates for diffuse astrocytic tumors in adults. Working toward the extended use of MRI data in integrated glioma diagnosis

Assess the contribution of preoperative MRI data in improving grading of adult astrocytomas reclassified according to the WHO 2016 and cIMPACT‐NOW update 3. Retrospective unicentric cohort study of 679 adult patients treated for newly diagnosed diffuse astrocytic and oligodendroglial tumors (January 2006–December 2016). We first systematically compared radiological (contrast enhancement present [CE+] vs. absent [CE−]) and histopathological findings (microvascular proliferation present [MPV+] vs. absent [MPV−]) to validate whether this comparing step of neoangiogenesis represents an efficient method to appreciate the representativity of the tumoral sampling. We focused on 629 cases of astrocytomas for radio‐histological integrated analyses. In 598 cases (95.1%), neoangiogenesis evaluated by MRI or histology (CE+/MPV+ or CE−/MPV−) was identical. For the CE+/MPV− and CE−/MPV+ groups (23 cases), the radio‐histological face‐to‐face evaluation allowed us to assess that for 13 cases (56.5%) the reason for this discrepancy was an undersampled tumor. We analyzed the group of CE+/MPV− (n = 8) and CE−/MPV+ (n = 2) in verified image‐guided tumoral samples. Finally, we identified three new prognostic subgroups for molecular glioblastomas: (1) “non‐representative sampling” (n = 9), (2) “Non neoangiogenic glioblastoma at the time of diagnosis, without contrast enhancement and microvascular proliferation” (n = 8), and (3) “contrast enhancing glioblastoma but without microvascular proliferation in a representative sample” (n = 4). Neoangiogenesis processes should be assessed to improve the prognosis accuracy of the current integrated diagnosis. We suggest adding imaging analyses during the neuropathological analysis of astrocytomas in adults.     

多平面经食管超声心动图的临床应用价值

目的　评价多平面经食管超声心动图 (TEE)在心血管病疾病诊断及治疗监测中的应用价值。方法　应用TEE对 3 7例经胸超声心动图诊断效果不满意患者进行检查。结果　所有患者均耐受TEE检查 ,纠正了 10例患者经胸超声心动图的诊断。 4例继发孔型房间隔缺损患者在TEE监测下行Amplatzer堵塞器关闭 ,效果良好。结论　TEE是一项安全、有效的诊断技术 ,对某些心血管疾病的诊断和介入监测具有重要的价值 ,值得推广应用     

费兆馥中医诊断学教案——颈项部诊法

针对中医诊断学教学与临床实用脱节的现象,费兆馥教授提出了"分部诊断教学法"。以颈项部诊法教案为例,主要从颈项部的结构与功能、病理变化、常见证候、典型医案、经典文献五个方面进行阐释。     

浅谈实验诊断学的教学改革

针对实验诊断学中教学滞后于临床的问题,借鉴他人教改经验,进行一系列的教学改革。通过开展教学互动,加强见习教学,改革考试方法,提高分析能力等措施,充分调动学生积极思考和主动参与意识,提高了教学质量。     

Nucleic Acid Testing (NAT) of Organ Donors: Is the ‘Best’ Test the Right Test? A Consensus Conference Report

Nucleic acid testing (NAT) for HIV, HBV and HCV shortens the time between infection and detection by available testing. A group of experts was selected to develop recommendations for the use of NAT in the HIV/HBV/HCV screening of potential organ donors. The rapid turnaround times needed for donor testing and the risk of death while awaiting transplantation make organ donor screening different from screening blood‐or tissue donors. In donors with no identified risk factors, there is insufficient evidence to recommend routine NAT, as the benefits of NAT may not outweigh the disadvantages of NAT especially when false‐positive results can lead to loss of donor organs. For donors with identified behavioral risk factors, NAT should be considered to reduce the risk of transmission and increase organ utilization. Informed consent balancing the risks of donor‐derived infection against the risk of remaining on the waiting list should be obtained at the time of candidate listing and again at the time of organ offer. In conclusion, there is insufficient evidence to recommend universal prospective screening of organ donors for HIV, HCV and HBV using current NAT platforms. Further study of viral screening modalities may reduce disease transmission risk without excessive donor loss.