Calculation of Clinical r.b.e. Values for Neutrons

Summary

A method is described for calculating r.b.e. values for normal tissues at risk in clinical neutron beam therapy. This is based on the assumption that with high l.e.t. radiations the slope of the cell survival curve is steeper, mainly in the initial or low-dose region. This effect is quantified by using two coefficients, one (ε) to produce a proportionate increase in the initial slope, and a second (η) determining the change in the terminal slope (D₀) of the survival curve.

Analysis of published experimental data shows ε to be a variable quantity, different for different tissues; ε is larger when the survival curve has a large shoulder or slope ratio (ρ). By contrast, η is relatively constant (for a given beam) and less dependent on the tissue or end-point studied.

For low doses, the r.b.e. approaches ε, which can be calculated given η (characteristic of the beam) and ρ (characteristic of the relevant tissue) [ε = η + ρ(η ? 1)]. This provides a useful approximation to the clinical r.b.e. for specific tissues relative to conventionally fractionated low-l.e.t. photons.     

Three‐dimensional first‐pass myocardial perfusion MRI using a stack‐of‐spirals acquisition

Three‐dimensional cardiac magnetic resonance perfusion imaging is promising for the precise sizing of defects and for providing high perfusion contrast, but remains an experimental approach primarily due to the need for large‐dimensional encoding, which, for traditional 3DFT imaging, requires either impractical acceleration factors or sacrifices in spatial resolution. We demonstrated the feasibility of rapid three‐dimensional cardiac magnetic resonance perfusion imaging using a stack‐of‐spirals acquisition accelerated by non‐Cartesian k‐t SENSE, which enables entire myocardial coverage with an in‐plane resolution of 2.4 mm. The optimal undersampling pattern was used to achieve the largest separation between true and aliased signals, which is a prerequisite for k‐t SENSE reconstruction. Flip angle and saturation recovery time were chosen to ensure negligible magnetization variation during the transient data acquisition. We compared the proposed three‐dimensional perfusion method with the standard 2DFT approach by consecutively acquiring both data during each R–R interval in cardiac patients. The mean and standard deviation of the correlation coefficients between time intensity curves of three‐dimensional versus 2DFT were 0.94 and 0.06 across seven subjects. The linear correlation between the two sets of upslope values was significant (r = 0.78, P < 0.05). Magn Reson Med, 2013. © 2012 Wiley Periodicals, Inc.     

Erfahrungen mit der gefäßgestielten Fibula in der Rekonstruktion von ossären Defekten bei primär malignen Knochentumoren

To bridge large bone defects after resection of primary malignant bone tumors, an autologous free vascularized fibular graft was used in 31 patients (15 x upper limb, 16 x lower limb). The median bone defect measured 16 cm (7-29.5 cm). At the lower extremity the vascularized fibular transplant was reinforced with an allograft and different osteosyntheses. At the upper limb stabilization of the transplant was obtained exclusively by plate osteosynthesis or condylar plate. Applications and the authors' experiences are described and discussed in terms of clinical outcome, graft union, functional outcome, and complications for each localization. After a median of 48 months, ten complications at the upper limb and eight complications at the lower limb, respectively, were seen requiring secondary surgical revision. Major complications such as perioperative deaths or secondary amputations were not observed. Functional evaluation showed better results for the lower than for the upper extremity, due mainly to en bloc resection of proportionally large amounts of soft tissues around the shoulder girdle for local tumor control. Despite the demanding operative procedure and a large number of controllable complications, the good functional outcome and high patient satisfaction indicate that the free vascularized fibular graft is an option for limb-sparing surgery of primary malignant bone tumors.     

Vascular endothelial growth factor and its receptor expression during the process of fracture healing

Objective： To study the expression regularity of vascular endothelial growth factor （VEGF） during the process of fracture healing, and the type of VEGF receptor expressed in the vascular endothelial cells of the fracture site.
Methods： The fracture model was made in the middle part of left radius in 35 rabbits. The specimens from the fracture site were harvested at 8, 24, 72 hours and 1, 3, 5, 8 weeks, and then fixed, decalcified, and sectioned frozenly to detect the expression of VEGF and its receptor at the fracture site by in situ hybridization and immunochemical assays.
Results： VEGF mRNA and VEGF expression was detected in many kinds of cells at the fracture site during 8 hours to 8 weeks after fracture. Fltl receptor of VEGF was found in the vascular endothelial cells at the fracture site during 8 hours to 8 weeks after fracture, and strong expression of flkl receptor was detected from 3 days to 3 weeks after fracture.
Conclusions： The expression of VEGF and fltl receptor appears during the whole course of fracture healing, especially from 1 to 3 weeks. Flkl receptor is highly expressed in a definite period after fracture. VEGF is proved to be involved in the vascular reconstruction and fracture healing.     

B7-H1及其受体PD-1在膀胱癌患者外周血免疫细胞中的表达及其临床意义

目的：研究膀胱癌患者外周血中树突状细胞（dendritic cells,DCs）表面B7-H1和CD8＋T淋巴细胞表面PD-1的表达情况及其临床意义。方法：分离30例膀胱癌患者外周血单个核细胞（peripheral blood mononuclear cell,PBMC）,联合培养后采用流式细胞术检测DCs表面B7-HI及CD8＋,T细胞表面PD-1的表达情况。结果：膀胱癌患者外周血DCs表面B7-H1表达水平及CD8＋T细胞表面PD-1表达水平均明显高于正常人,差异具有显著统计学意义（P〈0．01）,并且二者的表达水平随着病理分级和临床分期的增加均升高,差异有统计学意义（P〈0．05）。结论：在膀胱癌发生发展过程中存在着DCs表面B7-H1和CD8＋T细胞表面PD-1分子表达的上调,B7-H1／PD-1信号通路可能在T细胞免疫应答的初始阶段亦参与了膀胱癌免疫逃逸的发生。     

清金化痰汤对慢性阻塞性肺疾病急性加重期模型大鼠肺组织 Foxp3和 RORγt 表达的影响

目的探讨清金化痰汤对慢性阻塞性肺疾病急性加重期(AECOPD)模型大鼠肺组织叉头翼状螺旋转录因子P3(Foxp3)、维甲酸相关孤核受体γt(RORγt)表达的影响。方法 40只SPF Wistar雄性大鼠随机分为正常组、模型组、清金化痰汤组、克拉霉素组。除正常组外,其余组采取气道滴注脂多糖(LPS)联合烟熏的方法建立AECOPD气道黏液高分泌模型,并同时连续30 d分别给予生理盐水、清金化痰汤(8.4 g/kg)、克拉霉素(50 mg/kg)灌胃。实验第31天,提取大鼠肺组织,制作病理切片,并采用免疫组化法检测肺组织中黏蛋白5AC(Muc5AC)、中性粒细胞弹性蛋白酶(NE)的表达,观察Foxp3和RORγt的表达,免疫印迹法检测肺组织中Foxp3和RORγt的蛋白表达。结果与正常组比较,模型组Foxp3表达量无明显差异(P0.05),RORγt、Muc5AC、NE表达显著升高,Foxp3/RORγt显著下降(P0.01);清金化痰汤组与模型组比较,Foxp3表达量无明显差异(P0.05),RORγt、Muc5AC、NE表达显著降低,Foxp3/RORγt显著升高(P0.01或P0.05)。清金化痰汤组与克拉霉素组比较,Muc5AC显著降低(P0.05)。结论清金化痰汤可显著下调模型大鼠肺组织中RORγt蛋白表达,上调Foxp3/RORγt,这可能是清金化痰汤调节AECOPD黏液高分泌的机制之一。     

Die extrakorporale Therapie septischer Patienten

Zusammenfassung Trotz zahlreicher Fortschritte in der Intensivmedizin stellt die Behandlung von Patienten mit schwerer Sepsis und septischem Schock eine medizinische Herausforderung dar. In der Pathogenese der systemischen Inflammation (SIRS) kommt es zur exzessiven Freisetzung von multiplen endogenen und exogenen inflammatorischen Mediatoren [z. B. Lipopolysaccharid (LPS), Tumor-Nekrose-Faktor (TNF)-α, Interleukin (IL)-1, IL-6] und zur Entwicklung eines Multi- Organ-Versagen (MOV). Dies führt bekannterma?en zu schlechten überlebenszahlen septischer Patienten. Ein komplexes dynamisches Kontrollsystem führt in der Abfolge meist zur zeitnahen gegen-regulatorischen antiinflammatorischen Antwort mittels Induktion anti-inflammatorischer Mediatoren (IL-10, transforming growth factor-beta [TGF-β]). In einer gro?en Anzahl septischer Patienten kommt es durch eine Persistenz des inflammatorischen Reizes zu einer Deaktivierung von antigenpr?sentierenden Zellen bzw. zu einem Versagen des zellvermittelten Immunsystems („Immunparalyse“). Unselektive und selektive intermittierende und kontinuierliche extrakorporale Therapieverfahren wurden evaluiert, ob diese in der Lage sind, in inflammatorische durch den klinischen Verlauf günstig zu beeinflussen. Technologische Fortschritte im Hinblick auf die Entwicklung von extrakorporalen Plasmapherese- bzw. Adsorptionsverfahren bieten heute neue, effektive M?glichkeiten, Mediatoren aus der Blutbahn septischer Patienten zu entfernen. In der vorliegenden übersichtsarbeit werden aktuell verfügbare und zukünftige adjunktive extrakorporale Therapiestrategien vorgestellt und vor dem Hintergrund aktueller Studien diskutiert.      

Inverse relationship between colonic (Na+ + K+)-ATPase activity and degree of mucosal inflammation in inflammatory bowel disease

In inflammatory bowel disease (IBD), mucosal damage and loss of colonic function are regarded as major consequences of inflammation. Decreased colonic (Na⁺ + K⁺)-ATPase activities with diminished reabsorption of sodium and water have been found in active stages of ulcerative colitis. In this study, we report an inverse relationship between colonic (Na⁺ + K⁺)-ATPase activity and the degree of mucosal inflammation in 19 patients with IBD of mild to moderate disease activity. Various macroscopic and histologic types of mucosal lesions were differently associated with the (Na⁺ + K⁺)-ATPase activities. 5-nucleotidase activity was not associated with the degree of mucosal inflammation or the kind of macroscopic or histologic lesions. Our findings support the view that, in contrast to 5-nucleotidase, (Na⁺ + K⁺)-ATPase activity may better reflect the severity of mucosal damage and the degree of inflammation in IBD.