No Effect of Hypercholesterolemia on Elastase-Induced Experimental Abdominal Aortic Aneurysm Progression

Objective: Epidemiological studies link hyperlipidemia with increased risk for abdominal aortic aneurysms (AAAs). However, the influence of lipid-lowering drugs statins on prevalence and progression of clinical and experimental AAAs varies between reports, engendering controversy on the association of hyperlipidemia with AAA disease. This study investigated the impact of hypercholesterolemia on elastase-induced experimental AAAs in mice. Methods: Both spontaneous (targeted deletion of apolipoprotein E) and induced mouse hypercholesterolemia models were employed. In male wild type (WT) C57BL/6J mice, hypercholesterolemia was induced via intraperitoneal injection of an adeno-associated virus (AAV) encoding a gain-of-function proprotein convertase subtilisin/kexin type 9 mutation (PCSK9) followed by the administration of a high-fat diet (HFD) (PCSK9+HFD) for two weeks. As normocholesterolemic controls for PCSK9+HFD mice, WT mice were infected with PCSK9 AAV and fed normal chow, or injected with phosphate-buffered saline alone and fed HFD chow. AAAs were induced in all mice by intra-aortic infusion of porcine pancreatic elastase and assessed by ultrasonography and histopathology. Results: In spontaneous hyper- and normo-cholesterolemic male mice, the aortic diameter enlarged at a constant rate from day 3 through day 14 following elastase infusion. AAAs, defined as a more than 50% diameter increase over baseline measurements, formed in all mice. AAA progression was more pronounced in male mice, with or without spontaneous hyperlipidemia. The extent of elastin degradation and smooth muscle cell depletion were similar in spontaneous hyper- (score 3.5 for elastin and 4.0 for smooth muscle) and normo- (both scores 4.0) cholesterolemic male mice. Aortic mural macrophage accumulation was also equivalent between the two groups. No differences were observed in aortic accumulation of CD4+ or CD8+ T cells, B cells, or mural angiogenesis between male spontaneous hyper- and normocholesterolemic mice. Similarly, no influence of spontaneous hypercholesterolemia on characteristic aneurysmal histopathology was noted in female mice. In confirmatory experiments, induced hypercholesterolemia also exerted no appreciable effect on AAA progression and histopathologies. Conclusion: This study demonstrated no recognizable impact of hypercholesterolemia on elastase-induced experimental AAA progression in both spontaneous and induced hypercholesterolemia mouse models. These results add further uncertainty to the controversy surrounding the efficacy of statin therapy in clinical AAA disease

Drug-Coated Balloon versus Plain Balloon Angioplasty in the Treatment of Infrainguinal Vein Bypass Stenosis: A Systematic Review and Meta-Analysis

The optimal endovascular therapy for vein graft stenosis (VGS) following infrainguinal arterial bypass is yet to be established. Drug-coated balloons (DCB) have rapidly improved the inferior patency outcomes of angioplasty using a conventional plain balloon (PB). This study compares the efficacy of DCBs and PBs for the treatment of infrainguinal VGS. This systematic review and meta-analysis was performed according to the PRISMA statement. Multiple electronic searches were conducted in consultation with a health science librarian in September 2022. Studies describing the comparative outcomes of angioplasty using DCBs and PBs in the treatment of infrainguinal VGS were eligible. Datasets from one randomized controlled trial and two cohort studies with a total of 179 patients were identified. The results indicated no significant difference in target lesion revascularization between DCBs and PBs (OR, 0.64; 95% CI, 0.32–1.28; p = 0.21), with no significant heterogeneity between studies. Additionally, differences in primary patency, assisted primary patency, secondary patency, and graft occlusion were not significant. Subgroup analysis showed similar effects for different DCB devices. In conclusion, DCBs showed no significant benefit in the treatment of VGS compared to PBs. Given the small population size of this meta-analysis, future trials with a larger population are desired

Clinical impact of high-attenuation and cystic areas on computed tomography in fibrotic idiopathic interstitial pneumonias

Background: Quantitative computed tomography (CT) analysis has been proposed as a means of objectively assessing fibrotic interstitial pneumonia (IP) including idiopathic pulmonary fibrosis (IPF). We investigated whether percentages of high-attenuation areas (HAA%) and cystic areas (CA%) quantified from CT images were useful as indices of fibrotic IP. Methods: CT images of 74 patients with fibrotic idiopathic interstitial pneumonias (IPF, 36; non-specific interstitial pneumonia, 9; unclassifiable idiopathic interstitial pneumonia, 29) were analyzed via in-house computer software, which automatically calculated HAA%, CA%, mean lung density (MLD), standard deviation of lung density (SD-LD), kurtosis, and skewness from CT attenuation histograms. These indices were compared in each instance with physiologic measures, visual fibrosis score, clinical diagnosis, radiologic CT pattern, and prognosis. Results: HAA% correlated significantly with physiologic measures and visual fibrosis score to a moderate extent (%forced vital capacity, rs = -0.59; % carbon monoxide diffusion capacity, rs = -0.43; fibrosis score, rs = 0.23). Densitometric parameters (MLD, SD-LD, kurtosis, and skewness) correlated significantly with physiologic measures and fibrosis score (|rs| = 0.28-0.59). CA% showed no association with pulmonary functions but differed significantly between IPF and other interstitial pneumonias (IPs) (1.50 ± 2.41 % vs. 0.41 ± 0.80 %; P < 0.01) and between the definite usual interstitial pneumonia (UIP) pattern and other patterns (1.48 ± 2.38 % vs. 0.55 ± 1.19 %; P < 0.01). On univariate analysis, HAA%, MLD, SD-LD, kurtosis, skewness, fibrosis score, and definite UIP pattern all correlated with survival, with kurtosis alone identified as a significant predictor of mortality on multivariate analysis (hazard ratio = 0.67; 95 % CI, 0.44-0.96; P = 0.03). Conclusion: CA% and HAA% are novel quantitative CT indices with differing properties in fibrotic IP evaluations. HAA% largely reflects physiologic impairments, whereas CA% corresponds with diagnosis and HRCT pattern. Of the CT indices examined, kurtosis constituted the strongest predictor of mortality

Observation of the Pitch Angle Distribution of High-Energy Ions and their Radial Transport in the Central Cell of GAMMA10 * )

Suppression of the radial transport of the particles caused by low-frequency density fluctuations is one of the important subjects in the GAMMA10 tandem mirror. In GAMMA10, plasmas are mainly produced and heated with Ion Cyclotron Range of Frequency (ICRF) waves. The plasmas heated with ICRF waves have strong temperature anisotropy, because the ions are accelerated perpendicularly to the magnetic field line. In the GAMMA10 experiments, two types of low-frequency density fluctuations are observed; one is a drift-type fluctuation and the other is a flute-type fluctuation. In this paper, we study the radial transport of ICRF-produced high-energy ions which is caused by the low-frequency density fluctuations

No Effect of Hypercholesterolemia on Elastase-Induced Experimental Abdominal Aortic Aneurysm Progression

Objective: Epidemiological studies link hyperlipidemia with increased risk for abdominal aortic aneurysms (AAAs). However, the influence of lipid-lowering drugs statins on prevalence and progression of clinical and experimental AAAs varies between reports, engendering controversy on the association of hyperlipidemia with AAA disease. This study investigated the impact of hypercholesterolemia on elastase-induced experimental AAAs in mice. Methods: Both spontaneous (targeted deletion of apolipoprotein E) and induced mouse hypercholesterolemia models were employed. In male wild type (WT) C57BL/6J mice, hypercholesterolemia was induced via intraperitoneal injection of an adeno-associated virus (AAV) encoding a gain-of-function proprotein convertase subtilisin/kexin type 9 mutation (PCSK9) followed by the administration of a high-fat diet (HFD) (PCSK9+HFD) for two weeks. As normocholesterolemic controls for PCSK9+HFD mice, WT mice were infected with PCSK9 AAV and fed normal chow, or injected with phosphate-buffered saline alone and fed HFD chow. AAAs were induced in all mice by intra-aortic infusion of porcine pancreatic elastase and assessed by ultrasonography and histopathology. Results: In spontaneous hyper- and normo-cholesterolemic male mice, the aortic diameter enlarged at a constant rate from day 3 through day 14 following elastase infusion. AAAs, defined as a more than 50% diameter increase over baseline measurements, formed in all mice. AAA progression was more pronounced in male mice, with or without spontaneous hyperlipidemia. The extent of elastin degradation and smooth muscle cell depletion were similar in spontaneous hyper- (score 3.5 for elastin and 4.0 for smooth muscle) and normo- (both scores 4.0) cholesterolemic male mice. Aortic mural macrophage accumulation was also equivalent between the two groups. No differences were observed in aortic accumulation of CD4+ or CD8+ T cells, B cells, or mural angiogenesis between male spontaneous hyper- and normocholesterolemic mice. Similarly, no influence of spontaneous hypercholesterolemia on characteristic aneurysmal histopathology was noted in female mice. In confirmatory experiments, induced hypercholesterolemia also exerted no appreciable effect on AAA progression and histopathologies. Conclusion: This study demonstrated no recognizable impact of hypercholesterolemia on elastase-induced experimental AAA progression in both spontaneous and induced hypercholesterolemia mouse models. These results add further uncertainty to the controversy surrounding the efficacy of statin therapy in clinical AAA disease