587 research outputs found
Role of Perivascular and Visceral Adipose Tissues in Murine Models of Obesity and Atherosclerosis: A Dissertation
Expansion of visceral adipose tissue correlates with the metabolic syndrome and increased cardiovascular risk. Hypertrophied visceral fat becomes inflamed, causing increased lipolysis, decreased triglyceride storage, and lipotoxicity in skeletal muscle and liver resulting in insulin resistance. Perivascular adipose tissue is a normal component of the adventitia of arteries in humans and animals. Whether or not perivascular adipose also becomes inflamed in obesity is an important question, as this may be an additional, direct mechanism by which obesity causes vascular inflammation and disease.
Thus, for the first part of my thesis, we asked the question: does perivascular adipose in mice become inflamed with high fat feeding? In contrast to visceral adipose, macrophage gene expression was not increased in perivascular adipose in response to high fat diet, and this correlated with reduced F480 antigen positive cells as seen by immunohistochemistry and flow cytometry. Interestingly, perivascular adipose surrounding the thoracic aorta was similar to brown adipose tissue, a highly thermogenic fat depot, as shown by histology and DNA microarrays. Moreover, inter-scapular brown adipose was also resistant to diet induced inflammation in comparison to visceral adipose. These findings suggest that brown adipose in the perivascular niche may serve to protect the vasculature from diet induced inflammation, or from cold exposure, or both; whether or not brown perivascular adipose tissue exists in humans has yet to be determined.
In the second part of my thesis, we evaluated the role of perivascular adipose tissue in the apolipoprotein E knockout mouse, which exhibits severe hyperlipidemia and atherosclerosis, but is resistant to diet induced obesity and glucose intolerance. We tested the hypothesis that in this model of severe atherosclerosis, inflammation of perivascular adipose does occur. However, we were surprised to find that macrophage specific gene expression, as determined by either microarray analysis or quantitative polymerase chain reaction, was not increased in either the perivascular or the visceral adipose of high fat diet fed apolipoprotein E knockout mice. While the visceral adipose of wild type mice had extensive alterations in gene expression in response to high fat diet, in particular, enrichment of inflammatory gene expression and broad down regulation of peroxisome proliferator activated receptor gamma target genes, apolipoprotein E knockout visceral adipose did not. Importantly, the apolipoprotein E knockout visceral adipose instead showed increased expression of genes encoding enzymes in fatty acid oxidation pathways. High fat diet fed apolipoprotein E knockout visceral adipose was also characterized by smaller adipocyte size.
We conclude that, 1) inflammation in thoracic perivascular adipose does not occur in conjunction with diet induced obesity in normal animals nor with atherosclerosis in apolipoprotein E knockout mice, 2) thoracic perivascular adipose tissue is essentially identical to brown adipose tissue in mice, thus potentially protecting the vasculature from the cold, and 3) apolipoprotein E knockout mice remain lean on a high fat diet, despite hyperlipidemia and atherosclerosis, and the decreased adiposity correlates with decreased adipocyte size and adipose inflammation but increased oxidation of fatty acids. Consistent with previous work showing apolipoprotein E controls adipocyte uptake and deposition of triglyceride, its absence prevents adipocyte hypertrophy and resultant inflammation of visceral adipose tissue. Thus limiting adipocyte acquisition of fatty acids may be advantageous, provided that compensatory mechanisms to prevent sustained hyperlipidemia and peripheral organ lipotoxicity can be activated
Reflections by a Convicted Bystander and a Companion of Jesus
The purpose of this essay is to explain the reasons and benefits in bringing together the topics of Feminism and Jesuit education for a First-Year Seminar, to detail the curriculum steps and considerations in designing and proposing such a course, and to suggest a final list of overall dos and don’ts for running this course after one semester’s experience
Finding God in All Things ... and Back Home
Note: Jesuit philosophy and spirituality are known for their meditative and reflective dimensions. Accordingly, the Spiritual Exercises of Saint Ignatius include the elements of examination, meditation, consideration, and contemplation. These can be summarized in a single term, reflection. Jesuit higher education all too often and too easily can be distracted by the business and processes of the academy, necessary but not sufficient to achieve its real goals of personal formation and transformation. It is reflection that aids these ultimate aims. In this inaugural issue, and in subsequent issues, JHE is pleased to present a reflective article that calls us to imagine, to reason and to engage our affective sensibilities; in other words, it is a call to deep reflection – without which Jesuit higher education remains incomplete. - General Editor
Inaugural Address for Regis University
Inaugural Address Regis University September 25, 201
Emerging evidence for beneficial macrophage functions in atherosclerosis and obesity-induced insulin resistance
The discovery that obesity promotes macrophage accumulation in visceral fat led to the emergence of a new field of inquiry termed immunometabolism . This broad field of study was founded on the premise that inflammation and the corresponding increase in macrophage number and activity was a pathologic feature of metabolic diseases. There is abundant data in both animal and human studies that supports this assertation. Established adverse effects of inflammation in visceral fat include decreased glucose and fatty acid uptake, inhibition of insulin signaling, and ectopic triglyceride accumulation. Likewise, in the atherosclerotic plaque, macrophage accumulation and activation results in plaque expansion and destabilization. Despite these facts, there is an accumulating body of evidence that macrophages also have beneficial functions in both atherosclerosis and visceral obesity. Potentially beneficial functions that are common to these different contexts include the regulation of efferocytosis, lipid buffering, and anti-inflammatory effects. Autophagy, the process by which cytoplasmic contents are delivered to the lysosome for degradation, is integral to many of these protective biologic functions. The macrophage utilizes autophagy as a molecular tool to maintain tissue integrity and homeostasis at baseline (e.g., bone growth) and in the face of ongoing metabolic insults (e.g., fasting, hypercholesterolemia, obesity). Herein, we highlight recent evidence demonstrating that abrogation of certain macrophage functions, in particular autophagy, exacerbates both atherosclerosis and obesity-induced insulin resistance. Insulin signaling through mammalian target of rapamycin (mTOR) is a crucial regulatory node that links nutrient availability to macrophage autophagic flux. A more precise understanding of the metabolic substrates and triggers for macrophage autophagy may allow therapeutic manipulation of this pathway. These observations underscore the complexity of the field immunometabolism , validate its importance, and raise many fascinating and important questions for future study
Spontaneous coronary artery dissection in a patient with autosomal dominant polycystic kidney disease: a case report
BACKGROUND: Spontaneous coronary artery dissection is an uncommon syndrome. Its prevalence among patients with polycystic kidney disease is very rare, with no previously reported involvement of the right posterior descending coronary artery.
CASE PRESENTATION: We describe the case of a middle-aged Caucasian woman with polycystic kidney disease who presented with a non-ST elevation myocardial infarction. Cardiac catheterization revealed a dissection of her right posterior descending coronary artery. She was treated with dual antiplatelet therapy and had a favorable outcome.
CONCLUSION: We report a rare and interesting case of spontaneous coronary artery dissection of the right posterior descending coronary artery in a patient with polycystic kidney disease. It is important to consider spontaneous coronary artery dissection in the differential diagnosis of patients with polycystic kidney disease who present with an acute coronary syndrome
Acute symptomatic sinus bradycardia in a woman treated with pulse dose steroids for multiple sclerosis: a case report
INTRODUCTION: Sinus bradycardia has been reported after administration of pulse dose steroids, although most cases have occurred in children and are asymptomatic. We report a case of acute symptomatic sinus bradycardia due to pulse dose steroids in a woman with multiple sclerosis. Interestingly, this patient also suffered from inappropriate sinus tachycardia due to autonomic involvement of multiple sclerosis.
CASE PRESENTATION: A 48-year-old Caucasian woman with multiple sclerosis and chronic palpitations due to inappropriate sinus tachycardia was prescribed a 5-day course of intravenous methylprednisolone for treatment of an acute flare. Immediately following the fourth dose of intravenous methylprednisolone, she developed dyspnea, chest heaviness, and lightheadedness. She was referred to the emergency department where an electrocardiogram showed marked sinus bradycardia (40 beats per minute). Initial laboratory test results, including a complete blood count, basic metabolic profile and cardiac biomarkers, were normal. She was admitted for observation on telemetry monitoring. Her heart rate gradually increased and her symptoms resolved. Her outpatient dose of atenolol, taken for symptomatic inappropriate sinus tachycardia, was resumed.
CONCLUSIONS: Our patient\u27s acute symptoms were attributed to symptomatic sinus bradycardia due to pulse dose steroid treatment. Although several theories have been suggested to explain this phenomenon, the exact mechanism still remains unknown. It does not warrant any specific treatment, as it is a self-limiting side effect that resolves after discontinuing steroid infusion. Young patients who are free of any active cardiac conditions can safely be administered pulse dose steroids without monitoring. However, older patients with active cardiac conditions should have heart rate and blood pressure monitoring during infusion. Our patient also suffered from inappropriate sinus tachycardia, a manifestation of autonomic involvement of multiple sclerosis that has not been previously described. This case has implications for the pathogenesis and treatment of dysautonomia in patients with multiple sclerosis
Jesuit Worldwide Learning Graduations in Kakuma Refugee Camp and Dzaleka Refugee Camp July 2018
In July 2018, Father John Fitzgibbons, S.J. and Father Daniel Hendrickson, S.J., Presidents of Regis and Creighton Universities, respectively, hosted the Graduation Ceremonies at Kakuma Refugee Camp, Kenya and Dzaleka Refugee Camp, Malawi. Fifty students received Diplomas in Liberal Studies during the ceremonies. This article includes a brief description of Jesuit Worldwide Learning precedes Father Fitzgibbons’ speech to the graduates
Differentiating Pseudo Versus True Aortic Stenosis in Patients Without Contractile Reserve: A Diagnostic Dilemma
Low-flow, low-gradient (LF-LG) aortic stenosis with depressed left ventricular (LV) ejection fraction is a diagnostic challenge that is frequently encountered in the management of valvular heart disease. True-severe LF-LG aortic stenosis is amenable to valve replacement, whereas pseudo-severe aortic stenosis requires management of the underlying cardiomyopathy. This distinction is important as it serves as a critical branch point in guiding therapeutic decisions. We present the case of a 71-year-old male with LF-LG aortic stenosis who had a reduced and biphasic augmentation of LV flow during dobutamine stress echocardiography (DSE). Further evaluation revealed a stenotic left subclavian artery proximal to the left internal mammary artery graft to the left anterior descending (LAD) artery. Bypass of the subclavian stenosis reversed the LAD territory ischemia and confirmed pseudo-severe aortic stenosis on repeat DSE. Traditional DSE parameters are inconclusive in patients with LF-LG aortic stenosis with poor flow reserve. Calculation of the projected orifice area or measurement of aortic valve calcium via multidetector computed tomography (MDCT) may be required in this scenario. Most importantly, reversible causes of LV dysfunction identified during DSE for LF-LG aortic stenosis require a different treatment approach than that of true aortic stenosis
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