Secret History: Return of the Black Death Channel 4, 7-8pm In 1348 the Black Death swept through London, killing people within days of the appearance of their first symptoms. Exactly how many died, and why, has long been a mystery. This Secret History documentary follows experts as they pick through the evidence and reveal why the plague killed on such a scale. And they ask, what might be coming next?

Medscape

eMedicine创建于1996年，由近万名临床医师作为作者或编辑参与此临床医学知识库的建设，其中编辑均是来自美国哈佛、耶鲁、斯坦福、芝加哥、德克萨斯、加州大学等各分校医学院的教授或副教授。

eMedicine

Errors and margins in radiotherapy.

Accumulation of toxic protein aggregates-amyloid-β (Aβ) plaques and hyperphosphorylated tau tangles-is the pathological hallmark of Alzheimer disease (AD). Aβ accumulation has been hypothesized to result from an imbalance between Aβ production and clearance; indeed, Aβ clearance seems to be impaired in both early and late forms of AD. To develop efficient strategies to slow down or halt AD, it is critical to understand how Aβ is cleared from the brain. Extracellular Aβ deposits can be removed from the brain by various clearance systems, most importantly, transport across the blood-brain barrier. Findings from the past few years suggest that astroglial-mediated interstitial fluid (ISF) bulk flow, known as the glymphatic system, might contribute to a larger portion of extracellular Aβ (eAβ) clearance than previously thought. The meningeal lymphatic vessels, discovered in 2015, might provide another clearance route. Because these clearance systems act together to drive eAβ from the brain, any alteration to their function could contribute to AD. An understanding of Aβ clearance might provide strategies to reduce excess Aβ deposits and delay, or even prevent, disease onset. In this Review, we describe the clearance systems of the brain as they relate to proteins implicated in AD pathology, with the main focus on Aβ.

/pdf/clearance-systems-in-the-brain-implications-for-alzheimer-5ed0fh7q5o.pdf

Clearance systems in the brain—implications for Alzheimer disease

Purpose: To compile and review data on the topic of organ motion and its management Methods and Materials: Data were classified into three categories: (a) patient position-related organ motion, (b) interfraction organ motion, and (c) intrafraction organ motion Data on interfraction motion of gynecological tumors, the prostate, bladder, and rectum are reviewed Literature pertaining to the intrafraction movement of the liver, diaphragm, kidneys, pancreas, lung tumors, and prostate is compiled Methods for managing interfraction and intrafraction organ motion in radiation therapy are also reviewed

Organ motion and its management

Purpose : To quantify prostate and seminal vesicle positional changes (target motion) between treatment planning and delivery, and to identify the factors contributing to target motion. Methods and Materials : Thirty patients with adenocarcinoma of the prostate were prospectively evaluated by analyzing two sequential planning computerized tomography (CT) scans (S 1 , obtained prior to treatment, and S 2 , obtained during the fourth week of treatment) for each patient. All anatomical volumes of interest (soft tissue and bony) were reconstructed from transverse CT images and projected onto anterior and lateral beam's-eye view projections. Positional changes between S 1 and S 2 were eliminated by applying a rigid body translation and rotation. Target motion was then measured by recording the positional change between S 1 and S 2 at the edges (right, left, superior, inferior). Potential correlation of target motion with bladder volume, rectal volume, and rectal diameter changes were evaluated by linear regression analysis. Results : Neither the prostate nor seminal vesicles remained fixed with respect to bony anatomy between S 1 and S 2 . The distribution of positional changes were generally small (< 0.5 cm), but maximum displacements of 1.5-2.2 cm did occur, particularly in the lateral view. In this study, bladder volume changes between the scans were small and did not correlate with target motion (p = 0.67). Both rectal volume and rectal diameter changes correlated with target motion for both the prostate (p = 0.004 and 0.005, respectively) and seminal vesicles (p < 0.001 and < 0.001, respectively). However, neither the initial rectal volume nor the initial rectal diameter could be used to predict subsequent target motion when evaluated either singly or as part of a multiple regression model. Conclusions : Target motion occurs during the course of treatment planning and delivery and should be considered when designing conformal radiation fields. Although the target position at the time of planning CT may differ substantially from the mean treatment position, target motion cannot be predicted by evaluating simply measured parameters from a single scan, or double scan sequence.

Analysis of prostate and seminal vesicle motion : implications for treatment planning

Radiologic Evaluation in Lung Cancer: Diagnosis and Staging

Our objective was to determine if CT or MR imaging findings could be used to accurately predict resectability in patients with biopsy-proved malignant pleural mesotheliomas.CT and MR findings in 41 consecutive patients with malignant mesotheliomas who were referred to the thoracic surgery clinic for extrapleural pneumonectomy were studied by thoracic radiologists before surgery. Review of radiologic studies focused on local invasion of three separate regions: the diaphragm, chest wall, and mediastinum. Results of all imaging examinations were carefully correlated with intraoperative, gross, and microscopic pathologic findings.After radiologic and clinical evaluation, 34 patients (83%) had thoracotomy; 24 of these had tumors that were resectable. The sensitivity was high (> 90%) for both CT and MR in each region. Specificity, however, was low, probably because of the small number of patients with unresectable tumors.CT and MR provided similar information on resectability in most cases. Sensitivity was high...

https://www.ajronline.org/doi/pdfplus/10.2214/ajr.159.5.1414806

Malignant pleural mesothelioma: value of CT and MR imaging in predicting resectability.

Blended learning in medical education: Use of an integrated approach with web-based small group modules and didactic instruction for teaching radiologic anatomy1

Lymphangiomas are rare benign tumors most often seen in childhood When they occur in adults, radiologic diagnosis can be difficult A retrospective study of the CT and MR appearances of thoracic lymphangiomas in adult patients was performed in order to describe the range of radiologic features of these tumorsCases of adult lymphangioma at three institutions were identified in the records of 19 patients, predominantly female, 18-67 years oldThe most common CT appearance was a smoothly marginated cystic mass Unusual features included calcification, spiculated margins, and homogeneous soft-tissue attenuation The majority of cases were located in the anterior or superior mediastinum Unusual locations included the pericardium, pulmonary hilum, and pulmonary parenchyma Signal characteristics on MR images variedThe radiographic appearance of lymphangiomas in the chest in adult patients is varied The diagnosis cannot be suggested on the basis of radiologic studies alone

Kitt Shaffer

Papers

Analysis of prostate and seminal vesicle motion : implications for treatment planning

Radiologic Evaluation in Lung Cancer: Diagnosis and Staging

Malignant pleural mesothelioma: value of CT and MR imaging in predicting resectability.

Blended learning in medical education: Use of an integrated approach with web-based small group modules and didactic instruction for teaching radiologic anatomy1

Thoracic lymphangioma in adults: CT and MR imaging features.