Ferromagnetic materials in patients: detection before MR imaging

A number of surgical clips and other metallic materials embedded within patients have ferromagnetic properties that present a potential hazard when in the strong fields associated with magnetic resonance imaging. Several types of magnetometers and metal detectors were investigated as possible pre-imaging screening devices. The sensitivities and costs of these devices are given.     

Aktuelles aus dem Medizinrecht

Ohne Zusammenfassung

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Current aspects of forensic lawFrom October 2004 to March 2005

     

Acetaldehyde: déjà vu du jour

OBJECTIVE: The possibility that acetaldehyde is responsible for some of the central nervous system effects of ethanol has been a popular hypothesis for many years. This review examines the evidence of a role for acetaldehyde in the actions of ethanol in the brain. METHOD: The literature review was confined primarily to effects of acetaldehyde in the central nervous system in the realization that a great deal of information is also available on the actions of acetaldehyde in the periphery. The emphasis is on more recent findings, with only occasional references to older work. RESULTS: There are studies implicating acetaldehyde in nearly every central nervous system effect of ethanol that has been studied. With a few exceptions, the evidence for most of these effects is conflicting. For many years the dogma was that the brain did not metabolize ethanol. Any effects of acetaldehyde were therefore held to be due to acetaldehyde diffusing in from the blood. Recently, however, it has been established that ethanol is metabolized to acetaldehyde (primarily by catalase) and then to acetate (by aldehyde dehydrogenase) in the brain. These findings remove the problem that acetaldehyde does not penetrate the brain very well but leave questions as to what it does there. Almost invariably, the concentrations of acetaldehyde in the brain, under normal conditions of ethanol intoxication, are in the low micromolar range. Inhibition of aldehyde dehydrogenase will lead to increases of both peripheral and central acetaldehyde and usually to increases in the effects of ethanol or to behaviorally aversive effects. Stimulation of catalase should lead to increased levels of acetaldehyde in the brain, but this has not been directly demonstrated. Inhibition of catalase should lead to decreased acetaldehyde concentrations in vivo, but, again, this has not been directly demonstrated. Various effects of the direct application of acetaldehyde to the brain have been noted, but in most studies the concentration of acetaldehyde resulting from such manipulations has not been determined, and it is probably higher than that occurring during ethanol intoxication. These experiments tell us what acetaldehyde is capable of doing, not what it does after administration of ethanol. Still, this is a first step. CONCLUSIONS: Acetaldehyde is a product of ethanol metabolism in the brain. It clearly has central nervous system effects in its own right. The jury is still out as to whether it has effects under normal conditions of ethanol intoxication. This will remain the case until direct measurement of acetaldehyde concentrations in the brain is routinely accomplished under conditions in which behavioral effects of ethanol are also measured.     

The National Alzheimer's Coordinating Center (NACC) Database: an Alzheimer disease database

The National Alzheimer's Coordinating Center (NACC) is responsible for developing and maintaining a database of patient information collected from the 29 Alzheimer disease centers (ADCs) funded by the National Institute on Aging. Each of the centers collects center-determined data elements on patients enrolled into its center and transmits a minimum dataset to NACC. Data are managed differently at each center depending on that center's research needs. The centers' data systems vary from a single personal computer running spreadsheet software to a network of servers running an advanced data management system such as Oracle. The challenge for NACC is to expand and adjust previously collected data elements into an integrated database that could be used for administrative as well as research purposes. In addition, NACC sought to allow the centers to have the flexibility they needed for data submission. To accomplish this task, NACC designed a database that contained separate specific datasets each with individual data elements. NACC also designed a data management system to easily collect and manage these data. The NACC web site (www.alz.washington.edu) was created to allow access to the data.     

高压培养对血管内皮细胞t-PA和PAI-1的影响及卡托普利干预的效果

目的：高血压常伴有纤溶功能的异常,但其机制尚不清楚。本研究拟观察高静水压培养对人脐静脉内皮细胞（HUVECs）t-PA和PAI-1的影响以及卡托普利的干预效果,并探讨其可能的作用机制。方法：选用第4～6代HU-VECs,接种于24孔培养板中。依培养压力分为3组：大气压组（0mmHg）,中压组（90mmHg）,高压组（180mmHg）。在同一压力组,根据不同药物干预又分为两个亚组。即对照组（Ctrl）和卡托普利组（Cap,10^-5mol/L）。每组6份标本。采用ELISA法测定上清液t-PA和PAI-1的抗原浓度,并用细胞内总蛋白进行标化（单位：ng/μg proteins）。同时测定细胞内Ca^2＋浓度（nmol/L）。结果：与大气压组相比,中压和高压组t-PA浓度均显著降低,PAI-1浓度显著增高,t-PA/PAI-1比值显著降低,[Ca^2＋]i也显著增高。卡托普利对大气压组的t-PA、PAI-1和[Ca^2＋]i无显著影响,但在两个高压组,卡托普利显著升高t-PA浓度,显著降低PAI-1浓度,t-PA/PAI-1比值显著升高,[Ca^2＋]i显著地降低。结论：高静水压可损害内皮细胞的纤溶功能,而卡托普利的干预可降低高压所升高的[Ca^2＋]i,并改善高静水压对内皮细胞纤溶功能的影响。     

Dynamic holographic imaging of the beating human heart

Background--Currently, the reporting and archiving of echocardiographic data suffer from the difficulty of representing heart motion on printable 2-dimensional (2D) media. Methods and Results--We studied the capability of holography to integrate motion into 2D echocardiographic prints. Images of normal human hearts and of a variety of mitral valve function abnormalities (mitral valve prolapse, systolic anterior motion of the mitral leaflets, and obstruction of the mitral valve by a myxoma) were acquired digitally on standard echocardiographic machines. Images were processed into a data format suitable for holographic printing. Angularly multiplexed holograms were then printed on a prototype holographic "laser" printer, with integration of time in vertical parallax, so that heart motion became visible when the hologram was tilted up and down. The resulting holograms displayed the anatomy with the same resolution as the original acquisition and allowed detailed study of valve motion with side-by-side comparison of normal and abnormal findings. Comparison of standard echocardiographic measurements in original echo frames and corresponding hologram views showed an excellent correlation of both methods (P<0.0001, r2=0.979, mean bias=2.76 mm). In this feasibility study, both 2D and 3D holographic images were produced. The equipment needed to view these holograms consists of only a simple point-light source. Conclusions--Holographic representation of myocardial and valve motion from echocardiographic data is feasible and allows the printing on a 2D medium of the complete heart cycle. Combined with the recent development of online holographic printing, this novel technique has the potential to improve reporting, visualization, and archiving of echocardiographic imaging.     

Dermatomyositis in childhood. Review of eight cases

Eight cases of dermatomyositis in children admitted to Scottish hospitals between 1962 and 1972 have been reviewed. 6 of the 8 were currently in complete remission. In the other 2 cases the disease remained active in 1 and 1 had died of cardiac failure 6 years after the onset of disease. 5 had developed extensive soft tissue calcification for which 2 were treated with ethanehydroxydiphosphonate, one showing definite improvement and the other no change. All had been treated with corticosteroids and two in addition had had cytotoxic agents (methotrexate or cyclophosphamide). The overal prognosis had probably been improved by the use of corticosteroids but not by the cytotoxic drugs. Only one of the patients was incapacitated by residual contractures or calcinosis.     

1型糖尿病研究新进展

40年前创立的青少年糖尿病研究基金会((JDRF)是一个致力于通过支持研究来探寻1型糖尿病(TIDM)及其并发症治疗方法的组织.20世纪70年代有学者提出,TIDM和2型糖尿病(T2DM)的发病机制有根本的不同,T1DM与主要组织相容性复合体的人白细胞抗原(HLA)有独特相关性,有胰岛细胞自身抗体.     

Exogenous lung surfactant: effect on radiographic appearance in premature infants

At birth, premature infants of 25-29 weeks gestation, at high risk for development of neonatal respiratory distress syndrome (RDS), were given a single dose (90 mg) of calf lung surfactant extract (CLSE) by intratracheal instillation. The frequency and severity of RDS were assessed with use of a simple radiographic scoring system in which pulmonary parenchymal densities and the prominence of the air-bronchogram effect were used as indicators of widespread atelectasis. Radiographs were obtained in surfactant-treated and control infants within the first 90 minutes of life as part of an initial evaluation of their pulmonary status. Subsequent examinations were performed at less than 24 hours and less than 48 hours of age. Radiographic assessment of lung disease compared consistently with coordinated data on oxygen and mean airway pressure requirements of the infants. Both indicated a significantly decreased frequency and severity of RDS in the infants treated with surfactant. The results provide supporting evidence of the effectiveness of exogenous lung surfactant replacement in mitigating RDS in very premature infants.