挤压家兔后肢导致急性肝损伤和抗氧化能力降低

目的本实验观察挤压家兔后肢导致肝氧化损伤,探讨氧化应激在挤压家兔后肢导致肝损伤中的作用。方法用标准重物间断压迫家兔后肢复制模型。采用生化方法检测ALT和AST活性;分析天平称重方法检测肝脏湿干重比值(W/D);比色法测定肝组织超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、谷胱甘肽过氧化物酶(GSH-Px)活性和总抗氧化能力(T-AOC)以及丙二醛(MDA)含量变化;并观察肝组织病理学改变。结果血清ALT和AST活性明显增高(P<0.01),肝细胞明显肿胀,肝窦轻度淤血,而肝脏湿干重比值(W/D)轻度增加(P<0.05);肝脏氧化损伤明显加重,MDA含量增高,而肝脏抗氧化能力下降,SOD、CAT、GSH-Px活性和T-AOC分别比对照组降低了17%、29%、24%和21%(P均<0.01)。结论挤压家兔后肢引起急性肝损伤及肝脏的抗氧化能力下降;肝脏局部抗氧化能力下降可能是肝损伤的重要因素。     

Advisory committees at FDA: the Hinchey Amendment and "conflict of interest" waivers

In approving the Food and Drug Administration's (FDA) Fiscal Year 2007 budget, the House approved an amendment that would prevent the agency from using appropriated funds to waive certain conflicts of interest identified by members of its advisory committees. The amendment, introduced by Representative Hinchey and known as the Hinchey Amendment, provides that no funds may be used to: waive a conflict of interest under Section 505(n)(4) of the Federal Food, Drug, and Cosmetic Act (FDCA) for any voting member of an FDA advisory committee or panel; or make a certification under Section 208(b)(3) of Title 18 of the U.S. Code for any such voting member. This creates a problem, as ties to industry create the very expertise that FDA values in its outside advisors-under the Hinchey Amendment, these very ties would prevent them from serving as advisors to FDA during the drug approval process. The author opposes this change in the law and argues that the Hinchey Amendment would undermine congressional efforts in 1962 and 1989 to carefully balance the goals of attracting qualified experts and protecting agency decisionmaking. Further, the author argues, this change is unnecessary at FDA, because experts on FDA advisory committees divulge their connections to the industry, because the committees offer only advice and do not make agency decisions, and because the agency is under the watchful eye of Congress, the public, and public interest groups. The Article concludes that although FDA's advisory committee conflict-of-interest process can be improved, congressional action is unnecessary, and a change in the law through amendment to an appropriations bill that does not go through the ordinary legislative process (as an amendment to the FDCA or Title 18 would) is inappropriate. Instead, recommendations from organizations studying FDA practice, such as the OIG, GAO, and IOM, should be used to carefully and reflectively amend the process at the agency level, within the existing statutory framework.     

Lethal mixed intoxication with propofol in a medical layman

The authors report on a drug fatality of a 21-year-old man with a propofol (2,6-di-isopropylphenol) dependency. Propofol was detected in tissues and body fluids using SPME-GC/MS methods. The postmortem concentrations of propofol were 364 ng/ml in urine, 71 ng/ml in heart blood and 79 ng/ml in femoral blood. The drug addict had only an autodidactic medical knowledge, but had inserted himself a permanent cannula for intravenous injection of propofol several times a day. The injection material was bought via online auctions from eBay. The case illustrates how job-related drug dependencies become indistinct due to the free access to information and goods via the Internet.     

Reduction of postmortem angiography-induced tissue edema by using polyethylene glycol as a contrast agent dissolver

Postmortem investigation is increasingly supported by computed tomography (CT) and magnetic resonance imaging, in which postmortem minimal invasive angiography has become important. The newly introduced approach using an aqueous contrast agent solution provided excellent vessel visualization but was suspected to possibly cause tissue edema artifacts in histological investigations. The aim of this study was to investigate on a porcine heart model whether it is possible to influence the contrast agent distribution within the soft tissue by changing its viscosity by dissolving the contrast agent in polyethylene glycol (PEG) as a matrix medium. High-resolution CT scans after injection showed that viscosities above c. 15 mPa s (65% PEG) prevented a contrast agent distribution within the capillary bed of the left ventricular myocardium. Thereby, the precondition of edema artifacts could be reduced. Its minimal invasive application on human corpses needs to be further adapted as the flow resistance is expected to differ between different tissues.