Abstract
Background
Patterns of local endothelial shear stress (ESS) are heterogeneous along the course of individual coronary artery plaques. It is unknown how this heterogeneity affects the local ...natural history of plaque burden (PB) over time.
Objectives
To determine the effect of local ESS patterns along the course of coronary plaques at baseline on the heterogeneity of subsequent PB progression, regression, and quiescence in human coronary arteries and its link to clinical events.
Methods
302 patients from the PREDICTION study were included in the study. The PREDICTION study was an anatomic natural history followup study of patients treated for an acute coronary syndrome (ACS) performed in 15 Japanese clinical sites, as previously published 1. Invasive imaging was performed at baseline and, per protocol, at 6-10 months follow-up. Arterial geometry and ESS were derived from angiography/intravascular ultrasound-based vascular profiling. Plaques were identified as regions with plaque thickness > 0.5 mm in at least 3 consecutive 3-mm segments. Plaque progression was defined as change in PB (plaque area/total vessel area*100%) PB >+5% increase, regression as <-5% decrease, and quiescence as no change. The location of each sequential 3-mm segment along the plaque was related to the minimum lumen area (MLA). Performance of PCI in followup was assessed relative to the magnitude of PB change over time.
Results
661 plaques (5,658 3-mm segments) from 591 coronary arteries were identified. 56% of 3-mm segments per plaque manifested PB progression, 60% PB regression, and 96% quiescence, and the presence and number of these PB changes were significantly related to plaque length (p<0.002). PB change >20% was associated with low ESS (0.75±0.31 Pa) and marked regression (PB change <-20%) with high ESS (3.94±0.04 Pa) (p<0.001, Figure 1 right panel). 3-mm segments exhibiting substantial PB progression were located along the full length of the plaque, and seldom at the MLA (p=0.874, (Figure 1 left panel), while substantial PB regression was significantly located at the MLA (p<0.001). With increasing ∆PB progression in individual 3-mm segments, a significant increase in performance of PCI was observed (p=0.012, Figure 2).
Conclusions
PB natural history of 3-mm segments within an individual plaque is heterogeneous, driven by local ESS, with substantial plaque progression/luminal encroachment developing along the entire course of the plaque, and typically not near the MLA. PCI was associated with the magnitude of PB progression/luminal encroachment, regardless of where the progression occurred.Figure 1Figure 2
A Monte Carlo simulation was performed on the folding transition of a single stiff polymer chain. We have adapted a polymer model: neighboring beads are connected by a stick and the length of each ...stick is taken as
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of the Kuhn length. Among the products of the folding from the single chain, the toroidal structure is found to be the most stable. Rod and fused structures between rod and toroid are also generated as metastable states with almost infinite lifetime. These morphologies resemble the experimental structures observed with electron microscopy for the products of collapse from single duplex DNA chains.
Background: Recently established mucosal biopsy criteria reliably differentiate idiopathic inflammatory bowel disease (IBD) from other forms of colitis (non-IBD), and Crohn disease involving the ...colon (CD) from ulcerative colitis (UC) but were inconvenient in practical use because of the need for relatively complicated calculations. Our objectives were to establish simple criteria in which calculation could be done in the user's head and to measure their validity. Methods: On the basis of the above original criteria, we constructed two sets of criteria in which coefficients and constants were simplified to integral numbers. The first set of criteria consisted of the diagnostic categories 'definite IBD', 'probable IBD', 'unknown', 'probable non-IBD', and 'definite non-IBD'. Similarly, the second set had five categories from 'definite CD' to 'definite UC'. The validity of the criteria was evaluated in 117 patients with CD, 125 with UC, and 484 with non-IBD. Results: In categories of probable IBD and probable non-IBD both sensitivity and specificity exceeded 96.3%. Probable CD and probable UC showed sensitivities of 95.7% and 92.0% and specificities of 93.6% and 98.3%. Conclusions: Despite simplified coefficients and constants, the validity appeared to be high enough to apply the present criteria to routine work.
We evaluated the usefulness of contrast-enhanced, wide-band harmonic gray scale imaging for the diagnosis of hepatocellular carcinoma and compared it with helical computed tomography. Forty-eight ...patients with 61 hepatocellular carcinoma lesions were scanned by contrast-enhanced, wide-band harmonic gray scale imaging after an intravenous bolus injection of the contrast agent Levovist. Fifty-seven of the 61 hepatocellular carcinoma lesions showed hypervascular enhancement, and intratumoral vessels could be observed in 40 of the 57 lesions. Helical computed tomography revealed a high-attenuation area in 54 of the 61 lesions, whereas the other lesions showed an equivocal-attenuation area. Contrast-enhanced, wide-band harmonic gray scale imaging is a useful method for diagnosing the vascularity of hepatocellular carcinoma.
DC excitation of transformers due to geomagnetically induced currents was studied by model experiments. First, differences in the DC excitation phenomenon due to the iron core structure were studied ...using three typical small-scale models. The results verified that single-phase three-legged cores were most susceptible and three-phase three-legged cores least susceptible to such excitation effects. Secondly, the local heating due to DC excitation was quantitatively assessed using large-scale core form and shell form models with the most susceptible single-phase three-legged cores. The results demonstrated that the maximum temperature rise was approximately 110/spl deg/C due to the GIC (200 A/3 phases).< >
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