Microparticle-Induced Coagulation Relates to Coronary Artery Atherosclerosis in Severe Aortic Valve Stenosis

Background

Circulating microparticles (MPs) derived from endothelial cells and blood cells bear procoagulant activity and promote thrombin generation. Thrombin exerts proinflammatory effects mediating the progression of atherosclerosis. Aortic valve stenosis may represent an atherosclerosis-like process involving both the aortic valve and the vascular system. The aim of this study was to investigate whether MP-induced thrombin generation is related to coronary atherosclerosis and aortic valve calcification.

Methods

In a cross-sectional study of 55 patients with severe aortic valve stenosis, we assessed the coronary calcification score (CAC) as indicator of total coronary atherosclerosis burden, and aortic valve calcification (AVC) by computed tomography. Thrombin-antithrombin complex (TATc) levels were measured as a marker for thrombin formation. Circulating MPs were characterized by flow cytometry according to the expression of established surface antigens and by measuring MP-induced thrombin generation.

Results

Patients with CAC score below the median were classified as patients with low CAC, patients with CAC Score above the median as high CAC. In patients with high CAC compared to patients with low CAC we detected higher levels of TATc, platelet-derived MPs (PMPs), endothelial-derived MPs (EMPs) and MP-induced thrombin generation. Increased level of PMPs and MP-induced thrombin generation were independent predictors for the severity of CAC. In contrast, AVC Score did not differ between patients with high and low CAC and did neither correlate with MPs levels nor with MP-induced thrombin generation.

Conclusion

In patients with severe aortic valve stenosis MP-induced thrombin generation was independently associated with the severity of CAC but not AVC indicating different pathomechanisms involved in coronary artery and aortic valve calcification.     

Pitavastatin Reduces Inflammation in Atherosclerotic Plaques in Apolipoprotein E-Deficient Mice with Late Stage Renal Disease

Objectives

Chronic renal disease (CRD) accelerates atherosclerosis and cardiovascular calcification. Statins reduce low-density lipoprotein-cholesterol levels in patients with CRD, however, the benefits of statins on cardiovascular disease in CRD remain unclear. This study has determined the effects of pitavastatin, the newest statin, on arterial inflammation and calcification in atherogenic mice with CRD.

Methods and Results

CRD was induced by 5/6 nephrectomy in cholesterol-fed apolipoprotein E-deficient mice. Mice were randomized into three groups: control mice, CRD mice, and CRD mice treated with pitavastatin. Ultrasonography showed that pitavastatin treatment significantly attenuated luminal stenosis in brachiocephalic arteries of CRD mice. Near-infrared molecular imaging and correlative Mac3 immunostaining demonstrated a significant reduction in macrophage accumulation in pitavastatin-treated CRD mice. Pitavastatin treatment reduced levels of osteopontin in plasma and atherosclerotic lesions in CRD mice, but did not produce a significant reduction in calcification in atherosclerotic plaques as assesses by histology. CRD mice had significantly higher levels of phosphate in plasma than did control mice, which did not change by pitavastatin. In vitro, pitavastatin suppressed the expression of osteopontin in peritoneal macrophages stimulated with phosphate or calcium/phosphate in concentrations similar to those found in human patients with CRD.

Conclusion

Our study provides in vivo evidence that pitavastatin reduces inflammation within atherosclerotic lesions in CRD mice.     

Association Studies of Calcium-Sensing Receptor (CaSR) Polymorphisms with Serum Concentrations of Glucose and Phosphate,and Vascular Calcification in Renal Transplant Recipients

Background

Cardiovascular disease is the major cause of death in renal transplant recipients (RTRs) and linked to arterial calcification. The calcium-sensing receptor (CaSR), a G-protein coupled receptor, plays a pivotal role in extracellular calcium homeostasis and is expressed in the intimal and medial layers of the arterial wall. We investigated whether common CASR gene variants are predictors for aortic and coronary artery calcification or influence risk factors such as serum calcium, phosphate and glucose concentrations in RTRs.

Methods

Two hundred and eighty four RTRs were investigated for associations between three CASR promoter region single nucleotide polymorphisms (SNPs) (rs115759455, rs7652589, rs1501899), three non-synonymous CASR coding region SNPs (A986S, R990G, Q1011E), and aortic and coronary artery calcium mass scores, cardiovascular outcomes and calcification risk factors that included serum phosphate, calcium, total cholesterol and glucose concentrations.

Results

Multivariate analysis revealed that RTRs homozygous for the minor allele (SS) of the A986S SNP, when compared to those homozygous for the major allele (AA), had raised serum glucose concentrations (8.7±5.4 vs. 5.7±2.1 mmol/L, P<0.05). In addition, RTRs who were heterozygous (CT) at the rs115759455 SNP, when compared to those homozygous for the major allele (CC), had higher serum phosphate concentrations (1.1±0.3 vs. 1.0±0.2 mmol/L, P<0.05). CASR SNPs were not significant determinants for aortic or coronary artery calcification, and were not associated with cardiovascular outcomes or mortality in this RTR cohort.

Conclusions

Common CASR SNPs may be independent predictors of serum glucose and phosphate concentrations, but are not determinants of vascular calcification or cardiovascular outcomes.     

The appearance and modulation of osteocyte marker expression during calcification of vascular smooth muscle cells

Background

Vascular calcification is an indicator of elevated cardiovascular risk. Vascular smooth muscle cells (VSMCs), the predominant cell type involved in medial vascular calcification, can undergo phenotypic transition to both osteoblastic and chondrocytic cells within a calcifying environment.

Methodology/Principal Findings

In the present study, using in vitro VSMC calcification studies in conjunction with ex vivo analyses of a mouse model of medial calcification, we show that vascular calcification is also associated with the expression of osteocyte phenotype markers. As controls, the terminal differentiation of murine calvarial osteoblasts into osteocytes was induced in vitro in the presence of calcifying medium (containing ß-glycerophosphate and ascorbic acid), as determined by increased expression of the osteocyte markers DMP-1, E11 and sclerostin. Culture of murine aortic VSMCs under identical conditions confirmed that the calcification of these cells can also be induced in similar calcifying medium. Calcified VSMCs had increased alkaline phosphatase activity and PiT-1 expression, which are recognized markers of vascular calcification. Expression of DMP-1, E11 and sclerostin was up-regulated during VSMC calcification in vitro. Increased protein expression of E11, an early osteocyte marker, and sclerostin, expressed by more mature osteocytes was also observed in the calcified media of Enpp1^−/− mouse aortic tissue.

Conclusions/Significance

This study has demonstrated the up-regulation of key osteocytic molecules during the vascular calcification process. A fuller understanding of the functional role of osteocyte formation and specifically sclerostin and E11 expression in the vascular calcification process may identify novel potential therapeutic strategies for clinical intervention.     

RNA Interference of Myocyte Enhancer Factor 2A Accelerates Atherosclerosis in Apolipoprotein E-Deficient Mice

Objective

Myocyte enhancer factor-2A (MEF 2A) has been shown to be involved in atherosclerotic lesion development, but its role in preexisting lesions is still unclear. In the present study we aim to assess the role of MEF 2A in the progression of pre-existing atherosclerosis.

Methods

Eighty apolipoprotein E-deficient mice (APOE KO) were randomly allocated to control, scramble and MEF 2A RNA interference (RNAi) groups, and constrictive collars were used to induce plaque formation. Six weeks after surgery, lentiviral shRNA construct was used to silence the expression of MEF 2A. Carotid plaques were harvested for analysis 4 weeks after viral vector transduction. Inflammatory gene expression in the plasma and carotid plaques was determined by using ELISAs and real-time RT-PCR.

Results

The expression level of MEF 2A was significantly reduced in plasma and plaque in the RNAi group, compared to the control and NC groups, whereas the expression level of pro-inflammatory cytokines was markedly increased. Silencing MEF 2A using lentiviral shRNA significantly reduced the plaque collagen content and fibrous cap thickness, as well as increased plaque area. However, silencing MEF 2A had no obvious effect on plaque lipid content.

Conclusions

Lentivirus-mediated MEF 2A shRNA accelerates inflammation and atherosclerosis in APOE KO mice, but has no effect on lipoprotein levels in plasma.     

A Unique Combination of Nutritionally Active Ingredients Can Prevent Several Key Processes Associated with Atherosclerosis In Vitro

Introduction

Atherosclerosis is the underlying cause of cardiovascular disease that leads to more global mortalities each year than any other ailment. Consumption of active food ingredients such as phytosterols, omega-3 polyunsaturated fatty acids and flavanols are known to impart beneficial effects on cardiovascular disease although the combined actions of such agents in atherosclerosis is poorly understood. The aim of this study was to screen a nutritional supplement containing each of these active components for its anti-atherosclerotic effect on macrophages in vitro.

Results

The supplement attenuated the expression of intercellular adhesion molecule-1 and macrophage chemoattractant protein-1 in human and murine macrophages at physiologically relevant doses. The migratory capacity of human monocytes was also hindered, possibly mediated by eicosapentaenoic acid and catechin, while the ability of foam cells to efflux cholesterol was improved. The polarisation of murine macrophages towards a pro-inflammatory phenotype was also attenuated by the supplement.

Conclusion

The formulation was able to hinder multiple key steps of atherosclerosis development in vitro by inhibiting monocyte recruitment, foam cell formation and macrophage polarisation towards an inflammatory phenotype. This is the first time a combination these ingredients has been shown to elicit such effects and supports its further study in preclinical in vivo models.     

2013 ACC/AHA versus 2004 NECP ATP III Guidelines in the Assignment of Statin Treatment in a Korean Population with Subclinical Coronary Atherosclerosis

Background

The usefulness of the 2013 ACC/AHA guidelines for the management of blood cholesterol in the Asian population remains controversial. In this study, we investigated whether eligibility for statin therapy determined by the 2013 ACC/AHA guidelines is better aligned with the presence of subclinical coronary atherosclerosis detected by CCTA (coronary computed tomography angiography) compared to the previously recommended 2004 NCEP ATP III guidelines.

Methods

We collected the data from 5,837 asymptomatic subjects who underwent CCTA using MDCT during routine health examinations. Based on risk factor assessment and lipid data, we determined guideline-based eligibility for statin therapy according to the 2013 ACC/AHA and 2004 NCEP ATP III guidelines. We defined the presence and severity of subclinical coronary atherosclerosis detected in CCTA according to the presence of significant coronary artery stenosis (defined as >50% stenosis), plaques, and the degree of coronary calcification.

Results

As compared to the 2004 ATP III guidelines, a significantly higher proportion of subjects with significant coronary stenosis (61.8% vs. 33.8%), plaques (52.3% vs. 24.7%), and higher CACS (CACS >100, 63.6% vs. 26.5%) was assigned to statin therapy using the 2013 ACC/AHA guidelines (P < .001 for all variables). The area under the curves of the pooled cohort equation of the new guidelines in detecting significant stenosis, plaques, and higher CACS were significantly higher than those of the Framingham risk calculator.

Conclusions

Compared to the previous ATP III guidelines, the 2013 ACC/AHA guidelines were more sensitive in identifying subjects with subclinical coronary atherosclerosis detected by CCTA in an Asian population.     

Renal Interstitial Arteriosclerotic Lesions in Lupus Nephritis Patients: A Cohort Study from China

Objective

The aim of this study was to evaluate renal arteriosclerotic lesions in patients with lupus nephritis and investigate their associations with clinical and pathological characteristics, especially cardio-vascular features.

Design

A retrospective cohort study.

Participants

Seventy-nine patients with renal biopsy-proven lupus nephritis, diagnosed between January 2000 and June 2008 from Peking University First Hospital.

Results

In clinico-pathological data, patients with arteriosclerosis had higher ratio of hypertension and more severe renal injury indices compared with patients with no renal vascular lesions. More importantly, patients with renal arteriosclerosis had worse cardiac structure and function under transthoracic echocardiographic examination. Patients with renal arteriosclerosis tend to have higher ratios of combined endpoints compared with those of no renal vascular lesions, although the difference didn’t reach statistical meanings (P = 0.104).

Conclusion

Renal arteriosclerotic lesion was common and associated with vascular immune complex deposits in lupus nephritis. It might have a certain degree of association with poor outcomes and cardiovascular events, which needs further explorations.     

Quantification of Calcium Amount in a New Experimental Model: A Comparison between Ultrasound and Computed Tomography

Purpose

Calcification is an important prognostic factor in aortic valve stenosis. However, there is no ultrasound (US) method available to accurately quantify calcification in this setting to date. We aimed to validate a new US method for measuring the amount of calcium in an in vitro model, and compare it to computed tomography (CT), the current imaging gold standard.

Materials and Methods

An agar phantom (2% agar) was made, containing 9 different amounts of calcium-hydroxyapatite Ca₅(PO₄)₃OH (2 to 50mg). The phantoms were imaged with micro-CT and US (10 MHz probe). The calcium area (area_calcium) and its maximum pixel value (PV_max) were obtained. These values were summed to calculate CT and US calcium scores (∑(area_calcium × PV_max)) and volumes (∑area_calcium). Both US- and CT-calcium scores were compared with the calcium amounts, and with each other.

Results

Both calcium scores correlated significantly with the calcium amount (R² = 0.9788, p<0.0001 and R² = 0.8154, p<0.0001 for CT and US respectively). Furthermore, there was a significant correlation between US and CT for calcium volumes (R² = 0.7392, p<0.0001) and scores (R² = 0.7391, p<0.0001).

Conclusion

We developed a new US method that accurately quantifies the amount of calcium in an in vitro model. Moreover it is strongly correlated with CT.     

Critical Parameters of the In Vitro Method of Vascular Smooth Muscle Cell Calcification

Background

Vascular calcification (VC) is primarily studied using cultures of vascular smooth muscle cells. However, the use of very different protocols and extreme conditions can provide findings unrelated to VC. In this work we aimed to determine the critical experimental parameters that affect calcification in vitro and to determine the relevance to calcification in vivo.

Experimental Procedures and Results

Rat VSMC calcification in vitro was studied using different concentrations of fetal calf serum, calcium, and phosphate, in different types of culture media, and using various volumes and rates of change. The bicarbonate content of the media critically affected pH and resulted in supersaturation, depending on the concentration of Ca²⁺ and Pi. Such supersaturation is a consequence of the high dependence of bicarbonate buffers on CO₂ vapor pressure and bicarbonate concentration at pHs above 7.40. Such buffer systems cause considerable pH variations as a result of minor experimental changes. The variations are more critical for DMEM and are negligible when the bicarbonate concentration is reduced to ¼. Particle nucleation and growth were observed by dynamic light scattering and electron microscopy. Using 2mM Pi, particles of ~200nm were observed at 24 hours in MEM and at 1 hour in DMEM. These nuclei grew over time, were deposited in the cells, and caused osteogene expression or cell death, depending on the precipitation rate. TEM observations showed that the initial precipitate was amorphous calcium phosphate (ACP), which converts into hydroxyapatite over time. In blood, the scenario is different, because supersaturation is avoided by a tightly controlled pH of 7.4, which prevents the formation of PO₄ ^3--containing ACP.

Conclusions

The precipitation of ACP in vitro is unrelated to VC in vivo. The model needs to be refined through controlled pH and the use of additional procalcifying agents other than Pi in order to reproduce calcium phosphate deposition in vivo.     

Zileuton, 5-Lipoxygenase Inhibitor,Acts as a Chemopreventive Agent in Intestinal Polyposis,by Modulating Polyp and Systemic Inflammation

Purpose

Leukotrienes and prostaglandins, products of arachidonic acid metabolism, sustain both systemic and lesion-localized inflammation. Tumor-associated Inflammation can also contribute to the pathogenesis of colon cancer. Patients with inflammatory bowel disease (IBD) have increased risk of developing colon cancer. The levels of 5-lipoxygenase (5-LO), the key enzyme for leukotrienes production, are increased in colon cancer specimens and colonic dysplastic lesions. Here we report that Zileuton, a specific 5-LO inhibitor, can prevent polyp formation by efficiently reducing the tumor-associated and systemic inflammation in APC^Δ468 mice.

Experimental Design

In the current study, we inhibited 5-LO by dietary administration of Zileuton in the APC^Δ468 mouse model of polyposis and analyzed the effect of in vivo 5-LO inhibition on tumor-associated and systemic inflammation.

Results

Zileuton-fed mice developed fewer polyps and displayed marked reduction in systemic and polyp-associated inflammation. Pro-inflammatory cytokines and pro-inflammatory innate and adaptive immunity cells were reduced both in the lesions and systemically. As part of tumor-associated inflammation Leukotriene B4 (LTB4), product of 5-LO activity, is increased focally in human dysplastic lesions. The 5-LO enzymatic activity was reduced in the serum of Zileuton treated polyposis mice.

Conclusions

This study demonstrates that dietary administration of 5-LO specific inhibitor in the polyposis mouse model decreases polyp burden, and suggests that Zileuton may be a potential chemo-preventive agent in patients that are high-risk of developing colon cancer.     

Initial Experience with a Wireless Ultrasound-Guided Vacuum-Assisted Breast Biopsy Device

Objective

To determine the imaging characteristic of frequent target lesions of wireless ultrasound (US)-guided, vacuum-assisted breast biopsy (Wi-UVAB) and to evaluate diagnostic yield, accuracy and complication of the device in indeterminate breast lesions.

Materials and Methods

From March 2013 to October 2014, 114 women (age range, 29–76 years; mean age, 50.0 years) underwent Wi-UVAB using a 13-gauge needle (Mammotome Elite^®; Devicor Medical Products, Cincinnati, OH, USA). In 103 lesions of 96 women with surgical (n = 81) or follow-up (n = 22) data, complications, biopsy procedure, imaging findings of biopsy targets and histologic results were reviewed.

Results

Mean number of biopsy cores was 10 (range 4–25). Nine patients developed moderate bleeding. All lesions were suspicious on US, and included non-mass lesions (67.0%) and mass lesions (33.0%). Visible calcifications on US were evident in 57.3% of the target lesions. Most of the lesions (93.2%) were nonpalpable. Sixty-six (64.1%) were malignant [ductal carcinoma in situ (DCIS) rate, 61%] and 12 were high-risk lesions (11.7%). Histologic underestimation was identified in 11 of 40 (27.5%). DCIS cases and in 3 of 9 (33.3%) high-risk lesions necessitating surgery. There was no false-negative case.

Conclusion

Wi-UVAB is very handy and advantageous for US-unapparent non-mass lesions to diagnose DCIS, especially for calcification cases. Histologic underestimation is unavoidable; still, Wi-UVAB is safe and accurate to diagnose a malignancy.     

Thalidomide Inhibits Alternative Activation of Macrophages In Vivo and In Vitro: A Potential Mechanism of Anti-Asthmatic Effect of Thalidomide

Background

Thalidomide is known to have anti-inflammatory and immunomodulatory actions. However, the effect and the anti-asthmatic mechanism of thalidomide in the pathogenesis of asthmatic airways are not fully understood.

Objective

This study is designed to determine the effect and the potential mechanism of thalidomide in the pathogenesis of asthmatic airways using animal model of allergic asthma.

Methods

Six-week-old female BALB/C mice were sensitized with alum plus ovalbumin (OVA) and were exposed to OVA via intranasal route for 3 days for challenge. Thalidomide 200 mg/kg was given via gavage twice a day from a day before the challenge and airway hyperresponsivenss (AHR), airway inflammatory cells, and cytokines in bronchoalveolar lavage fluids (BALF) were evaluated. The expression levels of pro-inflammatory cytokines and other mediators were evaluated using ELISA, real time (RT)-qPCR, and flow cytometry. CRL-2456, alveolar macrophage cell line, was used to test the direct effect of thalidomide on the activation of macrophages in vitro.

Results

The mice with thalidomide treatment showed significantly reduced levels of allergen-induced BALF and lung inflammation, AHR, and the expression of a number of pro-inflammatory cytokines and mediators including Th2 related, IL-17 cytokines, and altered levels of allergen-specific IgG1/IgG2a. Of interesting note, thalidomide treatment significantly reduced expression levels of allergen- or Th2 cytokine-stimulated alternative activation of macrophages in vivo and in vitro.

Conclusion

These studies highlight a potential use of thalidomide in the treatment of allergic diseases including asthma. This study further identified a novel inhibitory effect of thalidomide on alternative activation of macrophages as a potential mechanism of anti-asthmatic effect of thalidomide.     

Coronary arterial calcification in rheumatoid arthritis: comparison with the Multi-Ethnic Study of Atherosclerosis

Introduction

Although cardiovascular morbidity and mortality are increased in rheumatoid arthritis, little is known about the burden of subclinical coronary atherosclerosis in these patients.

Methods

Using computed tomography, coronary artery calcification was measured in 195 men and women with rheumatoid arthritis aged 45 to 84 years without clinical cardiovascular disease and compared with 1,073 controls without rheumatoid arthritis enrolled in the Baltimore cohort of the Multi-Ethnic Study of Atherosclerosis.

Results

The prevalence of coronary calcification (Agatston score > 0) was significantly higher in men, but not women, with rheumatoid arthritis after adjusting for sociodemographic and cardiovascular risk factors (prevalence ratio = 1.19; P = 0.012). Among participants with prevalent calcification, those with rheumatoid arthritis had adjusted mean Agatston scores 53 units higher than controls (P = 0.002); a difference greater for men than women (P for interaction = 0.017). In all analyses, serum IL-6 attenuated the association between rheumatoid arthritis and coronary calcification, suggesting its role as a potential mediator of enhanced atherosclerosis. Notably, increasing severity of rheumatoid arthritis was associated with a higher prevalence and extent of coronary calcification among both men and women with rheumatoid arthritis, and for all age categories. The largest percentage difference in coronary arterial calcification between rheumatoid arthritis patients and their nonrheumatoid arthritis counterparts was observed in the youngest age category.

Conclusions

Increasing rheumatoid arthritis disease severity was associated with a higher prevalence and greater extent of coronary artery calcification, potentially mediated through an atherogenic effect of chronic systemic inflammation. Gender and age differences in association with coronary calcification suggest that preventive measures should be emphasized in men with rheumatoid arthritis, and considered even in younger rheumatoid arthritis patients with low levels of traditional cardiovascular risk factors.     

Microcystic Inner Nuclear Layer Changes and Retinal Nerve Fiber Layer Defects in Eyes with Glaucoma

Objective

To examine microcystic inner nuclear layer (INL) changes in glaucomatous eyes and to determine associated factors.

Design

Retrospective, cross-sectional, observational study.

Methods

Two hundred seventeen eyes of 133 patients with primary open angle glaucoma (POAG), 41 eyes of 32 patients with preperimetric glaucoma and 181 normal eyes of 117 subjects were ultimately included. Microcystic INL lesions were examined with infrared fundus images and with 19 vertical spectral domain optical coherence tomography (SD-OCT) images in the macular area.

Results

Microcystic INL changes were observed in 6.0% of eyes with POAG, but none of the normal eyes or eyes with preperimetric glaucoma showed microcystic INL changes. The proportion of eyes with advanced glaucoma was significantly larger (P = 0.013) in eyes with microcystic lesions than without. The visual field mean deviation (MD) slope was also significantly worse (P = 0.027) in eyes with microcystic lesions. No significant differences were observed in age, sex, refraction, axial length, intraocular pressure, or MD value between eyes with and without microcystic INL lesions. In several cases, microcystic INL lesions occurred along with glaucomatous visual field progression. The retinal nerve fiber layer (RNFL) thickness (P = 0.013) and ganglion cell layer (GCL) + inner plexiform layer thickness (P = 0.023) were significantly lower in areas with microcystic lesions than without. The INL was also significantly thicker (P = 0.002) in areas with microcystic lesions.

Conclusions

Microcystic INL lesions in glaucomatous eyes are closely associated with RNFL and GCL thinning and correlated with worse MD slope. These INL lesions may indicate focal and progressive damage in glaucoma.     

[18F]FDG Accumulation in Early Coronary Atherosclerotic Lesions in Pigs

Objective

Inflammation is an important contributor to atherosclerosis progression. A glucose analogue ¹⁸F-fluorodeoxyglucose ([¹⁸F]FDG) has been used to detect atherosclerotic inflammation. However, it is not known to what extent [¹⁸F]FDG is taken up in different stages of atherosclerosis. We aimed to study the uptake of [¹⁸F]FDG to various stages of coronary plaques in a pig model.

Methods

First, diabetes was caused by streptozotocin injections (50 mg/kg for 3 days) in farm pigs (n = 10). After 6 months on high-fat diet, pigs underwent dual-gated cardiac PET/CT to measure [¹⁸F]FDG uptake in coronary arteries. Coronary segments (n = 33) were harvested for ex vivo measurement of radioactivity and autoradiography (ARG).

Results

Intimal thickening was observed in 16 segments and atheroma type plaques in 10 segments. Compared with the normal vessel wall, ARG showed 1.7±0.7 times higher [¹⁸F]FDG accumulation in the intimal thickening and 4.1±2.3 times higher in the atheromas (P = 0.004 and P = 0.003, respectively). Ex vivo mean vessel-to-blood ratio was higher in segments with atheroma than those without atherosclerosis (2.6±1.2 vs. 1.3±0.7, P = 0.04). In vivo PET imaging showed the highest target-to-background ratio (TBR) of 2.7. However, maximum TBR was not significantly different in segments without atherosclerosis (1.1±0.5) and either intimal thickening (1.2±0.4, P = 1.0) or atheroma (1.6±0.6, P = 0.4).

Conclusions

We found increased uptake of [¹⁸F]FDG in coronary atherosclerotic lesions in a pig model. However, uptake in these early stage lesions was not detectable with in vivo PET imaging. Further studies are needed to clarify whether visible [¹⁸F]FDG uptake in coronary arteries represents more advanced, highly inflamed plaques.     

Tenotomy or Tenodesis for the Long Head of Biceps Lesions in Shoulders: A Systematic Review and Meta-Analysis

Background

Both tenotomy and tenodesis have been widely used for the treatment of long head of biceps tendon (LHBT) lesions, but the optimal strategy remains considerably controversial. In this meta-analysis of published studies, we compared the results of the two procedures.

Methods

A literature search that compared tenotomy with tenodesis was performed using MEDLINE, and Embase until August 2014. A total of 7 studies reporting data on 622 subjects were included. Study quality was evaluated using the PEDro critical appraisal tool and the NO quality assessment tool.

Results

Data synthesis showed higher functional outcomes, a lower complication rate, and longer surgical time in patients managed with tenodesis compared to tenotomy (Constant score, P = 0.02; Popeye sign, P < 0.001; cramp pain, P = 0.04; surgical time, P < 0.001, respectively).

Conclusion

This meta-analysis indicates that tenodesis results in better arm function and lower incidences of cramp pain and Popeye sign in LHBT lesions, while the procedure required longer surgical time compared to tenotomy. More sufficiently powered studies would be required to further determine the optimal strategy.     

Myocardial Structural and Biological Anomalies Induced by High Fat Diet in Psammomys obesus Gerbils

Background

Psammomys obesus gerbils are particularly prone to develop diabetes and obesity after brief period of abundant food intake. A hypercaloric high fat diet has been shown to affect cardiac function. Here, we sought to determine whether a short period of high fat feeding might alter myocardial structure and expression of calcium handling proteins in this particular strain of gerbils.

Methods

Twenty Psammomys obesus gerbils were randomly assigned to receive a normal plant diet (controls) or a high fat diet. At baseline and 16-week later, body weight, plasma biochemical parameters (including lipid and carbohydrate levels) were evaluated. Myocardial samples were collected for pathobiological evaluation.

Results

Sixteen-week high fat dieting resulted in body weight gain and hyperlipidemia, while levels of carbohydrates remained unchanged. At myocardial level, high fat diet induced structural disorganization, including cardiomyocyte hypertrophy, lipid accumulation, interstitial and perivascular fibrosis and increased number of infiltrating neutrophils. Myocardial expressions of pro-apoptotic Bax-to-Bcl-2 ratio, pro-inflammatory cytokines [interleukin (IL)-1β and tumor necrosis factor (TNF)-α], intercellular (ICAM1) and vascular adhesion molecules (VCAM1) increased, while gene encoding cardiac muscle protein, the alpha myosin heavy polypeptide (MYH6), was downregulated. Myocardial expressions of sarco(endo)plasmic calcium-ATPase (SERCA2) and voltage-dependent calcium channel (Cacna1c) decreased, while protein kinase A (PKA) and calcium-calmodulin-dependent protein kinase (CaMK2D) expressions increased. Myocardial expressions of ryanodine receptor, phospholamban and sodium/calcium exchanger (Slc8a1) did not change.

Conclusions

We conclude that a relative short period of high fat diet in Psammomys obesus results in severe alterations of cardiac structure, activation of inflammatory and apoptotic processes, and altered expression of calcium-cycling determinants.     

Lack of a Functioning P2X7 Receptor Leads to Increased Susceptibility to Toxoplasmic Ileitis

Background

Oral infection of C57BL/6J mice with the protozoan parasite Toxoplasma gondii leads to a lethal inflammatory ileitis.

Principal Findings

Mice lacking the purinergic receptor P2X7R are acutely susceptible to toxoplasmic ileitis, losing significantly more weight than C57BL/6J mice and exhibiting much greater intestinal inflammatory pathology in response to infection with only 10 cysts of T. gondii. This susceptibility is not dependent on the ability of P2X7R-deficient mice to control the parasite, which they accomplish just as efficiently as C57BL/6J mice. Rather, susceptibility is associated with elevated ileal concentrations of pro-inflammatory cytokines, reactive nitrogen intermediates and altered regulation of elements of NFκB activation in P2X7R-deficient mice.

Conclusions

Our data support the thesis that P2X7R, a well-documented activator of pro-inflammatory cytokine production, also plays an important role in the regulation of intestinal inflammation.     

Rapid mass movement of chloroplasts during segment formation of the calcifying siphonalean green alga, Halimeda macroloba

Background

The calcifying siphonalean green alga, Halimeda macroloba is abundant on coral reefs and is important in the production of calcium carbonate sediments. The process by which new green segments are formed over-night is revealed here for the first time.

Methodology/Principal Findings

Growth of new segments was visualised by epifluorescence and confocal microscopy and by pulse amplitude modulation (PAM) fluorimetry. Apical colourless proto-segments were initiated on day 1, and formed a loose network of non-calcified, non-septate filaments, containing no chloroplasts. Rapid greening was initiated at dusk by i) the mass movement of chloroplasts into these filaments from the parent segment and ii) the growth of new filaments containing chloroplasts. Greening was usually complete in 3–5 h and certainly before dawn on day 2 when the first signs of calcification were apparent. Mass chloroplast movement took place at a rate of ∼0.65 µm/s. Photosynthetic yield and rate remained low for a period of 1 to several hours, indicating that the chloroplasts were made de novo. Use of the inhibitors colchicine and cytochalasin d indicated that the movement process is dependent on both microtubules and microfilaments.

Significance

This unusual process involves the mass movement of chloroplasts at a high rate into new segments during the night and rapid calcification on the following day and may be an adaptation to minimise the impact of herbivorous activity.