基于自动勾画和快速蒙特卡罗计算的放射治疗全身器官剂量数据库平台的可行性研究

目的:探讨建立一种放射治疗全身器官剂量数据库平台的可行性。方法:使用基于深度学习的自动勾画软件DeepViewer?1例食管癌患者的全身CT上勾画全身器官，然后利用基于GPU加速的蒙特卡罗软件ARCHER计算相应的器官剂量分布，最后利用Lyman-Kutcher-Burman（LKB）模型评估放疗患者正常组织并发症概率（NTCP）。结果:针对该病例，成功建立基于DeepViewer?ARCHER和LKB模型的全身器官剂量数据库，发现距离靶区越近的器官剂量越大，其中心脏与靶区间距离最小，剂量为14.11 Gy，但因其模型参数特殊，通过LKB模型计算的NTCP为0.00%；左、右肺的剂量分别为3.19和1.16 Gy，但是NTCP值却很大，分别为2.13%和1.60%。对于距离靶区较远的头颈部器官（视交叉、视神经和眼）和腹部器官（直肠、膀胱和股骨头）剂量分别约为9和2 mGy，并且NTCP均近似为0.00%。结论:研究结果证明通过自动勾画软件DeepViewer?蒙特卡罗软件ARCHER和LKB模型建立全身器官剂量数据库的可行性。     

Psoriasis confined strictly to vitiligo areas – a Koebner‐like phenomenon?

Vitiligo and psoriasis are both common skin disorders. However, psoriasis strictly confined to pre-existing vitiligo areas is rare and suggests a causal relationship. We report here on two patients with a strict anatomical colocalization of vitiligo and psoriasis. The histopathological examinations showed typical changes for both diseases together with a dense infiltrate of CD4+ and CD8+ T cells. By immunohistochemistry, intracytoplasmatic granzyme B and tumour necrosis factor alpha (TNF-alpha) were detected within the T-cell population, suggesting the functional activity of these cells and the creation of a local T helper 1 (Th1)-cytokine milieu. Additionally, in one patient we could identify anti-melanocytic T cells by tetramer staining and enzyme-linked immunospot (ELISPOT) analysis. These skin-infiltrating lymphocytes might trigger, by the local production of Th-1 cytokines such as TNF-alpha and interferon-gamma (IFN-gamma), the eruption of psoriatic plaques in patients with a genetic predisposition for psoriasis.     

Heart Rate Variability Predicts Severe Hypotension after Spinal Anesthesia

Background: Hypotension due to vasodilatation after spinal anesthesia (SA) may be harmful. Heart rate variability, an indirect measure of autonomic control, may predict hypotension.

Methods: One hundred patients were studied. Retrospectively, heart rate variability was analyzed in 30 patients, classified depending on the lowest systolic blood pressure (SBP) after SA. Seventy patients were studied prospectively, assigned to one of two groups by their low to high frequency ratio (LF/HF) before SA. Sensitivity and specificity of LF/HF for prediction of decrease of SBP greater 20% of baseline were tested.

Results: Retrospective analysis showed differences of LF/HF depending on the degree of hypotension after SA. Prospective analysis demonstrated significant differences of SBP after SA depending on baseline LF/HF (mean +/- SD): low LF/HF (1.3 +/- 0.7) = > SBP: 91 +/- 8% of baseline versus high LF/HF (5.5 +/- 2.4) = > SBP: 66 +/- 10% of baseline (P < 0.05). Baseline LF/HF as well as high frequency and proportional decrease of SBP after SA correlated significantly, in contrast to baseline hemodynamic parameters heart rate and SBP. A receiver operator curve characteristic analysis showed a sensitivity and specificity of LF/HF > 2.5 of 85% to predict SBP decrease of greater than 20% of baseline after SA.     

Cannabis and driving: A new perspective

Cannabis and driving is an emerging injury‐prevention concern. The incidence of driving while affected by cannabis is rising in parallel with increased cannabis use in the community. Younger drivers are at particular risk. Improvements in research methodology, technology and laboratory testing methods have occurred in the last 10 years. These cast doubt on earlier results and conclusions. Studies now show that cannabis has a significant impairing effect on driving when used alone and that this effect is exaggerated when combined with alcohol. Of particular concern is the presence of cannabis as the sole psychoactive drug in an increasing number of road fatalities and the lack of any structural response to this problem. A review of testing methods, laboratory and real driving studies, and recent epidemiological studies is presented. Suggestions for methods of further data collection and future public policy are made.     

Aktualisierte Kurzfassung der Leitlinien zur Pr?vention, Diagnostik und Therapie der nosokomial erworbenen Pneumonie

Hintergrund:  

Die nosokomiale Pneumonie gehört zu den häufigsten nosokomialen Infektionen und ist die häufigste auf der Intensivstation. Die nosokomiale Pneumonie ist mit einer signifikanten Mortalität und Morbidität assoziiert, und ihr Auftreten verschlechtert die Prognose des Patienten deutlich. Nach der Definition der DRGs auch im deutschen Krankenhaussystem ist die nosokomiale Pneumonie überwiegend Sache des Krankenhauses und kann somit nicht nur das Ergebnis der Patientenbehandlung, sondern auch das finanzielle Ergebnis des Krankenhauses beeinträchtigen.     

Endocrine evaluation after endoscopic third ventriculostomy (ETV) in children

Objective Endoscopic third ventriculostomy (ETV) is a standard procedure for the treatment of obstructive hydrocephalus in children. Main part of the procedure is the perforation of the third ventricle floor (tuber cinereum). This structure is part of the hypothalamic–pituitary neuronal network of cerebral endocrine regulation. There are no systematic data available about the endocrine status after ETV in children. Materials and methods We examined 20 children who had undergone ETV. Examination included laboratory tests (adrenocorticotropic hormone, prolactin, insulin-like growth factor 1 [IGF-1], IGF-binding protein 3 [IGFBP-3], fT3, fT4, thyroid-stimulating hormone [TSH], serum osmolarity, electrolytes, glucose, urea, follicle-stimulating hormone [FSH] and luteinizing hormone [LH], and testosterone in selected patients), measurement of weight, height, and head circumference, and physical examination. The study was approved by the Ethics Committee of the Medical Faculty of Kiel University. Results In seven patients, prolactin was moderately elevated. One patient demonstrated a significantly increased prolactin (56.3 ng/ml). In all eight patients, this was the only laboratory value that was out of the normal range; all other parameters were normal. Three other patients showed one abnormal parameter (decrease in FSH and LH, increase in TSH, decrease in IGF-1 and IGFBP-3). In nine patients, weight or height was not within the 3rd to 97th centiles for age. Discussion and conclusion More patients than expected demonstrated endocrine laboratory abnormalities. However, there was no clinical relevance in any of the studied patients. It remains inconclusive whether ETV contributes to the abnormalities of prolactin levels or to other endocrine parameters in pediatric patients. Longitudinal studies are necessary to delineate the effect of ETV on endocrine regulation. Presented at the Third World Conference of the International Study Group on Neuroendoscopy (ISGNE), Marburg, Germany, 15–18 June 2005.