Accuracy and utility of three-dimensional contrast-enhanced magnetic resonance angiography in planning carotid stenting

BackgroundContrast-enhanced magnetic resonance angiography (CE-MRA) is a proven diagnostic tool for the evaluation of carotid stenosis; however, its utility in planning carotid artery stenting (CAS) has not been addressed. This study assessed the accuracy of three-dimensional CE-MRA as a noninvasive screening tool, compared with digital subtraction angiography (DSA), for evaluating carotid and arch morphology before CAS.MethodsIn a series of 96 CAS procedures during a 2-year period, CE-MRAs and DSAs with complete visualization from the aortic arch to the intracranial circulation were obtained before CAS in 60 patients. Four additional patients, initially considered potential candidates for CAS, were also evaluated with CE-MRA and DSA. The two-by-two table method, receiver operating characteristic curve, and Bland-Altman analyses were used to characterize the ability of CE-MRA to discriminate carotid and arch anatomy, suitability for CAS, and degree of carotid stenosis.ResultsThe sensitivity and specificity of CE-MRA were, respectively, 100% and 100% to determine CAS suitability, 87% and 100% to define aortic arch type, 93% and 100% to determine severe carotid tortuosity, and 75% and 98% to detect ulcerated plaques. CE-MRA had 87% sensitivity and 100% specificity for the detection of carotid stenosis ≥80%. The accuracy of CE MRA to determine optimal imaging angles and stent and embolic protection device sizes was >90%. The operative technique for CAS was altered because of the findings of preoperative CE-MRA in 22 procedures (38%). The most frequent change in the operative plan was the use of the telescoping technique in 11 cases (18%). CAS was aborted in four patients (5%) due to unfavorable anatomy identified on CE-MRA, including prohibitive internal carotid artery tortuosity (n = 1), long string sign of the internal carotid artery (n = 2), and concomitant intracranial disease (n = 1). Among patients considered suitable for CAS by CE-MRA, technical success was 100%, and the 30-day stroke/death rate was 1.6%.ConclusionsContrast-enhanced magnetic resonance angiography of the arch and carotid arteries is accurate in determining suitability for CAS and may alter the operative technique. Certain anatomic contraindications for CAS may be detected without DSA. Although CE-MRA is less accurate to estimate the degree of stenosis, it can accurately predict imaging angles, and stent and embolic protection device size, which may facilitate safe and expeditious CAS

Did the ancient egyptians record the period of the eclipsing binary Algol - the Raging one?

The eclipses in binary stars give precise information of orbital period changes. Goodricke discovered the 2.867 days period in the eclipses of Algol in the year 1783. The irregular orbital period changes of this longest known eclipsing binary continue to puzzle astronomers. The mass transfer between the two members of this binary should cause a long-term increase of the orbital period, but observations over two centuries have not confirmed this effect. Here, we present evidence indicating that the period of Algol was 2.850 days three millenia ago. For religious reasons, the ancient Egyptians have recorded this period into the Cairo Calendar, which describes the repetitive changes of the Raging one. Cairo Calendar may be the oldest preserved historical document of the discovery of a variable star.Comment: 26 pages, 5 figures, 11 table

WW domain-containing oxidoreductase promotes neuronal differentiation via negative regulation of glycogen synthase kinase 3β

WW domain-containing oxidoreductase (WWOX), a putative tumour suppressor, is suggested to be involved in the hyperphosphorylation of Alzheimer's Tau. Tau is a microtubule-associated protein that has an important role in microtubule assembly and stability. Glycogen synthase kinase 3β (GSK3β) has a vital role in Tau hyperphosphorylation at its microtubule-binding domains. Hyperphosphorylated Tau has a low affinity for microtubules, thus disrupting microtubule stability. Bioinformatics analysis indicated that WWOX contains two potential GSK3β-binding FXXXLI/VXRLE motifs. Immunofluorescence, immunoprecipitation and molecular modelling showed that WWOX interacts physically with GSK3β. We demonstrated biochemically that WWOX can bind directly to GSK3β through its short-chain alcohol dehydrogenase/reductase domain. Moreover, the overexpression of WWOX inhibited GSK3β-stimulated S396 and S404 phosphorylation within the microtubule domains of Tau, indicating that WWOX is involved in regulating GSK3β activity in cells. WWOX repressed GSK3β activity, restored the microtubule assembly activity of Tau and promoted neurite outgrowth in SH-SY5Y cells. Conversely, RNAi-mediated knockdown of WWOX in retinoic acid (RA)-differentiated SH-SY5Y cells inhibited neurite outgrowth. These results suggest that WWOX is likely to be involved in regulating GSK3β activity, reducing the level of phosphorylated Tau, and subsequently promoting neurite outgrowth during neuron differentiation. In summary, our data reveal a novel mechanism by which WWOX promotes neuronal differentiation in response to RA

From Craft to Nature: The Emergence of Natural Teleology

A teleological explanation is an explanation in terms of an end or a purpose. So saying that ‘X came about for the sake of Y’ is a teleological account of X. It is a striking feature of ancient Greek philosophy that many thinkers accepted that the world should be explained in this way. However, before Aristotle, teleological explanations of the cosmos were generally based on the idea that it had been created by a divine intelligence. If an intelligent power made the world, then it makes sense that it did so with a purpose in mind, so grasping this purpose will help us understand the world. This is the pattern of teleological explanation that we find in the Presocratics and in Plato. However, with Aristotle teleology underwent a change: instead of thinking that the ends were explanatory because a mind had sought to bring them about, Aristotle took the ends to operate in natural beings independently of the efforts of any creative intelligence. Indeed, he thought that his predecessors had failed to understand what was distinctive of nature, namely, that its ends work from the inside of natural beings themselves

Aristotle on the Matter for Birth, Life, and the Elements

This essay considers three case studies of Aristotle’s use of matter, drawn from three different scientific contexts: menstrual fluid as the matter of animal generation in the Generation of Animals, the living body as matter of an organism in Aristotle’s On the Soul (De Anima), and the matter of elemental transformation in Generation and Corruption. I argue that Aristotle conceives of matter differently in these treatises (1) because of the different sorts of changes under consideration, and (2) because sometimes he is considering the matter for one specific change, and sometimes the matter for all of a thing’s natural changes. My account allows me to explain some of the strange features that Aristotle ascribes to the matter for elemental transformation in Generation and Corruption II. These features were interpreted by later commentators as general features of all matter. I argue that they are a result of the specific way that Aristotle thinks about the transmutation of the elements

Autism, Realism, And System Balance In A Student Group.

PhDSocial psychologyUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/185333/2/6106426.pd

Effects of member influence in an organization: Phenomenology versus organization structure

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/86725/1/astannen-effects_member_influence.pd

Organizational Control Structure

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/86662/1/Human_Relations-1963-Smith-299-316.pd