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Purpose. Lens proteins underwent nonenzymatic glycation, and the advanced glycation end products (AGEs) were detected by immunological assays. One of the major AGE structures is Nε-(carboxymethyl)lysine (CML). Since the involvement of AGEs in the pathogenesis of diabetic complications is speculated, the effects of CML formation on proteins were studied. Methods. CML adducts were generated in recombinant αA-and αB-crystallins by incubation with glyoxylic acid and NaBH3CN. SDS-PAGE and size exclusion chromatography were used to detect subunit degradation and high-molecular-weight (HMW) aggregation. Conformational change was determined by fluorescence and circular dichroism (CD) measurements. The chaperone function was studied by DTT-induced aggregation of insulin. Results. Lysine modification was estimated to be 60–90% depending on the conditions of incubation. No subunit degradation or HMW aggregation was observed. Fluorescence and CD measurements detected a conformational change in CML adducts. Measurements of chaperone-like activity, however, indicated that the formation of CML increased the protein's ability to protect insulin against DTT-induced aggregation. Conclusions. Although CML adducts of αA- and αB-crystallins, the major AGE structures formed in vitro, changed protein conformation, no subunit degradation and HMW aggregation were observed. Moreover, the CML adducts increased chaperone-like activity of both αA- and αB-crystallins. The results suggest that CML formation alone may not play a major role in protein aggregation and lens opacity. [ABSTRACT FROM AUTHOR]

There are two tryptophan residues in the lens αB-crystallin, Trp9 and Trp60. We prepared two Trp → Phe substituted mutants, W9F and W60F, for use in a spectroscopic study. The two tryptophan residues contribute to Trp fluorescence and near-ultraviolet circular dichroism (UV CD) differently. The major difference in the near-UV CD is the contribution of 1La of Trp: it is positive in W60F but becomes negative in W9F. Further analysis of the near-UV CD shows an increased intensity in the region of 270-280 nm for W60F, suggesting that the Tyr48 is affected by the W60F mutation. It appears that Trp60 is located in a more rigid environment than Trp9, which agrees with a recent structural model in which Trp60 is in a β-strand. [ABSTRACT FROM AUTHOR]

Background: The coronary computed tomography angiography features of acute spontaneous coronary artery dissection, an important cause of acute coronary syndrome in young women, have not been assessed., Methods: The "Virtual" Multicenter Mayo Clinic Spontaneous Coronary Artery Dissection Registry was established in 2010 and includes retrospective and prospective patient data. Retrospective assessment of acute coronary computed tomography angiography images was performed for 14 patients (16 vessels) who had images performed within two days of invasive coronary angiography diagnosis of acute spontaneous coronary artery dissection., Results: Four pertinent diagnostic coronary features of acute spontaneous coronary artery dissection were observed in order of prevalence: 1) abrupt luminal stenosis (64%); 2) intramural hematoma (50%); 3) tapered luminal stenosis (36%); and 4) dissection (14%). Additional findings include epicardial fat stranding (42%), coronary tortuosity (29%), and coronary bridge (14%). Fifty percent of patients had myocardial hypoperfusion in the myocardial distribution of the dissected coronary artery., Conclusions: We define key coronary computed tomography angiography features of acute spontaneous coronary artery dissection, the most common of which are abrupt luminal stenosis and intramural hematoma. Importantly, intramural hematoma appears similar to noncalcified atherosclerotic plaque, emphasizing the importance of invasive coronary angiography for acute diagnosis of spontaneous coronary artery dissection until the sensitivity and specificity of coronary computed tomography angiography is better understood.

Objective: The purpose of this article is to introduce a technique for transrectal drainage of deep pelvic abscesses performed under interactive MRI guidance., Conclusion: A new method for triorthogonal image plane MRI guidance was developed and used to interactively monitor the puncture needle on continuously updated sets of adjustable three-plane images. The merits and limitations of the technique are highlighted and the patient population that is likely to benefit from this approach is suggested.