Gregory Sloop

Gregory Sloop
Idaho College of Osteopathic Medicine

M.D.

About

90
Publications
15,961
Reads
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2,061
Citations
Citations since 2017
29 Research Items
678 Citations
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Introduction
"I can't understand why people are frightened of new ideas. I'm frightened of the old ones." - John Cage, 1912-92, U.S. composer and music theorist. I invite you to read essays I have written for the general public. "Managing the Diseases of Superabundance," https://medium.com/@bigdaddypathologist/managing-the-diseases-of-superabundance-2d998e0537e4, "The Vascular Elasticity Theory of Aging," https://medium.com/@bigdaddypathologist/the-vascular-elasticity-theory-of-aging-f70d25fb2652, and "What Do Paradigm Shifts Look Like?" https://medium.com/@bigdaddypathologist/what-do-paradigm-shifts-look-like-e8f06c00c11f
Additional affiliations
July 1995 - September 2005
LSU Medical Center in New Orleans
Position
  • Professor (Associate)
July 1995 - September 2005
Louisiana State University
Position
  • Professor (Associate)

Publications

Publications (90)
Article
Serum hypercholesterolemia is theorized to accelerate atherogenesis by augmenting cholesterol accumulation (insudation) in the arterial intima. The author views this theory as an example of what the noted philosopher of science Imre Lakatos called 'degenerative science', because data have forced several modifications of the theory. Although the the...
Article
Full-text available
1. Increased blood or plasma viscosity has been observed in almost all conditions associated with accelerated atherosclerosis. Cognizant of the enlarging body of evidence implicating increased viscosity in atherogenesis, we hypothesize that the effects of low-density lipoprotein and high-density lipoprotein on blood viscosity correlate with their a...
Article
Full-text available
Deaths due to atherothrombosis are increasing throughout the world except in the lowest socio-demographic stratum. This is despite 60 years of study and expenditure of billions of dollars on lipid theory. Nevertheless, mainstream atherothrombosis theory persists even though it has failed numerous tests. Contrary data are ignored, consistent with th...
Article
Full-text available
Inflammation causes hyperviscosity. This phenomenon is fully expressed in coronavirus 2019. The cardiac complications of coronavirus 2019 are most commonly caused by hyperviscosity, not viral invasion of endothelial cells or cardiomyocytes. This hyperviscosity is caused by high concentrations of acute phase reactants, especially fibrinogen, and imm...
Article
Full-text available
Many of the complications of severe coronavirus disease-2019 (COVID-19) are caused by blood hyperviscosity driven by marked hyperfibrinogenemia. This results in a distinctive hyperviscosity syndrome which affects areas of high and low shear. A change in blood viscosity causes a threefold inverse change in blood flow, which increases the risk of thr...
Article
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This paper examines the changes needed to make a circulatory system suitable for life in Antarctic waters.
Article
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Background The copy number of the oligonucleotide 5’-purine-uridine-uridine-purine-uridine-3’ (purUUpurU) motif in a viral genome was previously shown to correlate with the severity of acute illness. This study aimed to determine whether purUUpurU content correlates with virulence in other single-strand RNA (ssRNA) viruses that vary in clinical sev...
Article
Full-text available
Background Coronavirus disease 2019 (COVID-19) can be associated with pathologic inflammation. The authors hypothesize that a high copy number of a purine-uridine-rich nucleotide motif is present in the genome of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and hyperactivates innate immunity. Methods The number of purine-uridine-uri...
Article
Full-text available
We explain basic hemorheology, the abnormalities of blood viscosity in renal failure patients, the effect of hemodialysis on blood viscosity, how protein-bound uremic toxins and gut-derived uremic toxins cause disease, and how blood viscosity can be used to improve management of hemodialysis patients.
Preprint
Full-text available
Hemodialysis typically increases blood viscosity. Increased blood viscosity plays a role in accelerating atherothrombosis, anemia, and decreasing life expectancy in hemodialysis patients. Elevated blood viscosity increases the risk of thrombosis, decreases tissue perfusion, and increases systemic vascular resistance. Elevated blood viscosity also r...
Article
Full-text available
In contemporary medical literature two essential aspects for optimal blood flow are often overlooked: blood viscosity and preferential flow patterns in the cardiovascular system. Blood is a non-Newtonian fluid, which means that its viscosity is not constant, but will rise exponentially at a lower blood velocity. Also, increased levels of inflammato...
Article
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Myocarditis and thrombosis following immunization for coronavirus disease 2019 is caused by elevated blood viscosity due to the host inflammatory response. Inflammation elevates blood viscosity by causing hemoconcentration and the acute phase reaction, which increases the concentration of large proteins such as fibrinogen and immunoglobins and decr...
Raw Data
This is an essay I published on Medium.com. It was written for the general public, but the info it contains will be new to many physicians and scientists.
Article
Full-text available
Blood viscosity is increased by elevated concentrations of acute phase reactants and hypergammaglobulinemia in inflammation. These increase blood viscosity by increasing plasma viscosity and fostering erythrocyte aggregation. Blood viscosity is also increased by decreased erythrocyte deformability, as occurs in malaria. Increased blood viscosity co...
Article
https://medium.com/@bigdaddypathologist/managing-the-diseases-of-superabundance-2d998e0537e4
Conference Paper
Full-text available
The results of this study can easily be explained by the "healthy user/adherer" effect. People who adhere to preventative treatments are more likely to follow other aspects of a healthy lifestyle. High perceived psychological stress is associated with an increased risk of coronary heart disease [1]. A drug with limited efficacy or even a placebo co...
Preprint
Full-text available
This is a letter in response to the impact of the CANTOS study and canakinumab on cardiology in the year since the study was published.
Article
Full-text available
Apolipoprotein(a) [apo(a)] is an apolipoprotein unique to lipoprotein(a) [Lp(a)]. Although it has no known function, Lp(a) is a risk factor for accelerated atherothrombosis. We hypothesize that LPA, the gene which encodes apo(a), is a heretofore unrecognized unprocessed pseudogene created by duplication of PLG, the gene which encodes plasminogen. U...
Article
Full-text available
The authors hypothesize that consumption of interesterified fats may be the cause of the continuous increase in cardiovascular deaths in the United States which began in 2011. Interesterification is a method of producing solid fats from vegetable oil and began to supplant partial hydrogenation for this purpose upon recognition of the danger of tran...
Article
Full-text available
The authors hypothesize that thrombosis causes both the complications of atherosclerosis as well as the underlying lesion, the atherosclerotic plaque, which develops from the organization of mural thrombi. These form in areas of slow blood flow, which develop because of flow separation created by changing vascular geometry and elevated blood viscos...
Chapter
Areas of low shear in the arterial tree are prone to develop atherosclerotic plaques. In areas of changing arterial geometry, such as branches and curves, regions of low shear develop because of asymmetric redistribution of erythrocyte velocity. This process is dampened by aortic compliance, which decreases peak systolic blood velocity and augments...
Book
The impact of blood viscosity on health and disease has been neglected, even though viscosity is a fundamental property of any fluid. It is inversely proportional to flow, so increased blood viscosity predisposes to thrombosis. Blood viscosity is directly related to systemic vascular resistance, and so blood viscosity affects blood pressure. Blood...
Chapter
Before the advent of evidence-based medicine, occasional successes with therapeutic phlebotomy may have occurred in cases of hypertension, pneumonia, polycythemia vera, and "plethora." The successful use of therapeutic phlebotomy in treating pulmonary hypertension, metabolic syndrome, angina pectoris, and improving cerebral blood flow are reviewed....
Chapter
Atherosclerosis is a disease of low shear. All genuine risk factors for atherosclerosis accelerate the disease process by creating larger areas of lower shear via increased aortic stiffness, increased blood viscosity, or both. Areas of low shear are predisposed to developing mural thrombi. Organization of mural thrombi results in an atherosclerotic...
Article
Full-text available
Validated formulae have been used to estimate low-and high-shear blood viscosity without the need for direct measurement. These formulae are dependent on common laboratory measurements, hematocrit and plasma protein concentration, making them convenient for use in large clinical studies. These formulae may be adequate for correlating blood viscosit...
Article
Full-text available
Uric acid may be a risk factor for atherosclerotic cardiovascular disease, although the data conflict and the mechanism by which it may cause cardiovascular disease uncertain. This study was performed to test the hypothesis that uric acid, an anion at physiologic pH, can cause erythrocyte aggregation, which itself is associated with cardiovascular...
Article
Full-text available
Without an active regulatory feedback loop, increased blood viscosity could lead to a vicious cycle of ischemia, increased erythropoiesis, further increases of blood viscosity, decreased tissue perfusion with worsened ischemia, further increases in red cell mass, etc. We suggest that an increase in blood viscosity is detected by mechanoreceptors in...
Article
Full-text available
Normal aortic compliance allows cardiac output to be distributed throughout the cardiac cycle, resulting in lower peak blood velocity. Loss of compliance with aging, hypertension, and possibly other risk factors for atherosclerosis increases peak blood velocity, creating eddy currents in areas of changing vascular geometry, as well as creating adve...
Article
Full-text available
The pathogenesis of several major cardiovascular diseases, including atherosclerosis, hypertension, and the metabolic syndrome, is not widely understood because the role of blood viscosity is overlooked. Low-density lipoprotein accelerates atherosclerosis by increasing blood viscosity in areas of low flow or shear, predisposing to thrombosis. Ather...
Article
Full-text available
Renewed interest in the age-old concept of "bloodletting", a therapeutic approach practiced until as recently as the 19th century, has been stimulated by the knowledge that blood loss, such as following regular donation, is associated with significant reductions in key hemorheological variables, including whole blood viscosity (WBV), plasma viscosi...
Article
Despite continuing advances in both prevention and treatment of acute cardiovascular disease events, the high prevalence of cardiovascular disease reveals limitations in the understanding of its etiology. Blood viscosity is a measure of the resistance of blood to flow and has been clinically correlated with numerous established cardiovascular risk...
Article
To determine the effect of age on the extent of pathogenesis of Staphylococcus keratitis in the mouse. Corneas of young and aged mice (BALB/c, A/J, and C57BL/6) were scarified and topically inoculated with S. aureus. Slit lamp examination (SLE) and histopathology were performed, and bacterial colony forming units and myeloperoxidase activity were d...
Article
To evaluate the effect of age and other risk factors for atherosclerosis on arterial blood velocity, carotid arteries in 179 healthy individuals ranging from 21 to 102 years old were examined using color Doppler ultrasonography. Velocity in common and internal carotid arteries decreased consecutively from young adults to very elderly people except...
Article
A case of furuncular myiasis is reported. The life cycle of the parasite, differential diagnosis, host response, and therapy are briefly discussed.
Article
To investigate the corneal virulence of toxin-deficient mutants of Staphylococcus aureus in young and aged mice in a topical inoculation model of keratitis. Corneas of young and aged A/J mice were scarified and topically inoculated with a log phase S. aureus parent strain (8325-4), an alpha-toxin-deficient mutant (DU1090), or an Agr-defective mutan...
Article
Interferon regulatory factor-1 (IRF-1) is a transcription factor with antiviral, proinflammatory and tumor suppressor properties. We examined the role of IRF-1 in dextran sulfate sodium colitis, a murine model of inflammatory bowel disease, to determine if absence of the gene would protect against colitis. C57BL/6J mice with a targeted disruption o...
Article
To assess the frequency of shedding of herpes simplex virus type 1 (HSV-1) DNA in tears and saliva of asymptomatic individuals. Fifty subjects without signs of ocular herpetic disease participated. Serum samples from all subjects were tested for HSV IgG antibodies by enzyme-linked immunosorbent assay (ELISA) and for HSV-1 by neutralization assay. H...
Article
Peripheral facial nerve palsy is a common sequela of traumatic craniofacial injury, often resulting in dramatic and sometimes permanent functional deficits. Exogenous agents and methods of repair that accelerate axonal regeneration would be of great benefit to the multitude of patients with facial nerve injuries. The objective of this study was to...
Article
To examine whether the atherosclerotic risk from cholesterol is modified by serum glucose level. Data from the Pathobiological Determinants of Atherosclerosis in Youth (PDAY) study of 1530 individuals with complete autopsy data for total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C) and hemoglobin A1c (HbA1c) were examined with any...
Article
To define factors that protect the eye from Staphylococcus aureus keratitis and limit tissue damage once keratitis occurs. Rabbit tears were analyzed for bactericidal and phospholipase A(2) (PLA(2)) activities on S. aureus. Inhibition by spermidine of PLA(2) anti-staphylococcal activity in tears was tested in vitro and in vivo. Rabbits immunized wi...
Article
To establish, in the scarified mouse eye, a new model of Staphylococcus aureus keratitis suitable for studies of pathogenesis and host defense mechanisms. Corneas of three strains of mice (BALB/c, A/J, and C57BL/6) were scarified and inoculated with S. aureus strain 8325-4. Mice underwent slit lamp examination (SLE) at 1, 3, 5, 7, and 9 days after...
Article
The association of Chlamydia pneumoniae (C. pneumoniae) detection with atherosclerosis has been controversial because of recent conflicting results. In order to assess how and to what extent C. pneumoniae detection contributes to atherosclerosis, the association between immunohistochemical detection of C. pneumoniae antigen, intimal lesions, and th...
Article
Full-text available
To determine the pathogenic role of gamma- and alpha-toxin in a rabbit model of Staphylococcus aureus keratitis. S. aureus strains Newman (expressing gamma-toxin), Newman Delta(hlg) (deficient in gamma-toxin), Newman Delta(hlg)/pCU1 hlg(+) (chromosomal gamma-toxin-deficient mutant rescued by a plasmid encoding gamma-toxin), and Newman Delta(hla) (a...
Article
PURPOSE. To determine the pathogenic role of gamma- and alpha-toxin in a rabbit model of Staphylococcus aureus keratitis. METHODS. S. aureus strains Newman (expressing gamma-toxin), Newman Deltahlg (deficient in gamma-toxin), Newman Deltahlg/pCU1 hlg(+) (chromosomal gamma-toxin- deficient mutant rescued by a plasmid encoding gamma-toxin), and Newma...
Article
The chapter presents a rationale for determining the localization of oxidation-specific epitopes. The chapter also discusses the methods by which these epitopes can be localized with particular attention to immunohistochemistry. Additionally, it describes technical issues associated with immunohistochemistry for oxidation-specific epitopes and prov...
Article
Atherosclerotic plaque-like lesions are prevalent in synthetic arteriovenous shunts created to provide vascular access for hemodialysis. Similarities to atherosclerotic plaques in native arteries include eccentric location, immunoreactivity for smooth muscle actin, dystrophic calcifications, superimposed thrombi, and foam cells. Fatty streaks were...
Article
Full-text available
To develop a topical inoculation model of Staphylococcus aureus keratitis in which scarification, contact lenses, and spermidine are used to inhibit the host defenses and to investigate the role of alpha-toxin in this infection. An alpha-toxin-positive parent strain (8325-4), its isogenic alpha-toxin-negative mutant (DU1090), and a genetically resc...
Article
To determine the effectiveness of lysostaphin treatment of experimental endophthalmitis caused by methicillin-resistant Staphylococcus aureus (MRSA). In one experiment, rabbits were injected in the mid-vitreous with 50 or 200 CFU of S. aureus; untreated groups and groups injected intra-vitreally at 8 or 24 hours postinfection with vehicle or lysost...
Article
Full-text available
I urge anyone interested in this topic to read "The psychoanalysis and death of George Gershwin: an American tragedy", by Mark Leffert, M.D., The Journal of the American Academy of Psychoanalysis and Dynamic Psychiatry" 39(3): 421-452, 2011. I think this is the last word on the topic. Dr. Leffert reviews the topic throughougly and even manages to a...
Article
To test the hypothesis that peak blood velocity in the common carotid artery is increased in association with elevated blood pressure, the authors measured peak common carotid blood velocity in 458 subjects by color Doppler ultrasonography. Blood pressure was measured at the time of ultrasound examination by automated sphygmomanometer. Peak blood v...
Article
We prospectively evaluated the diameter of the common bile duct in 1,018 patients between the ages of 60 to 96 over a 4 year period to determine if there is a significant change in its size with aging. All of the patients included in the study were being evaluated primarily for carotid or peripheral vascular disease. Any patients with a history of...
Article
The raised fatty streak (fatty plaque) is the gross term for the lesion intermediate between the juvenile (flat) fatty streak and the raised lesion of atherosclerosis. We measured the percentage of intimal surface involved with flat fatty streaks, raised fatty streaks, and raised lesions in the aortas and right coronary arteries of 2876 autopsied p...
Article
Fifty-seven sections of human vessels, collected in the Pathobiological Determinants of Atherosclerosis in Youth study from individuals aged 25-34, were stained with two monoclonal antibodies to oxidatively-modified lysine. Intensity and extent of immunoreactivity were graded by three pathologists. Aorta from a Watanabe heritable hyperlipidemic (WH...
Article
The author proposes that paired helical filaments, which contain the protein tau in the fibrillar or beta-pleated sheet conformation, compete with microtubules for binding to nascent, soluble tau. Binding of nascent tau to tau in the beta-pleated sheet conformation autocatalyzes the conformational change into the beta-pleated sheet conformation. As...
Article
To determine if the DNA strand breaks caused by tissue sectioning result in terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labeling (TUNEL) reactivity. The incidence and location of TUNEL-positive nuclei were determined in 5- and 15-micron sections of human stomach. Five- and 15-micron sections of tonsil were stai...
Article
Full-text available
Objective.—To determine if the DNA strand breaks caused by tissue sectioning result in terminal deoxynucleotidyl transferase–mediated deoxyuridine triphosphate nick end-labeling (TUNEL) reactivity. Methods.—The incidence and location of TUNEL-positive nuclei were determined in 5- and 15-μm sections of human stomach. Five- and 15-μm sections of tons...
Article
Full-text available
The inflammatory response during Staphylococcus keratitis was analyzed biochemically and histologically to determine the source of the neutrophils infiltrating the tear film and cornea. Rabbit eyes were swabbed and then examined by slit-lamp microscopy at 0, 5, 10, 15, 20, and 25 hours after intracorneal inoculation with Staphylococcus aureus. Bact...
Article
Given the enlarging body of evidence implicating increased blood viscosity in atherogenesis, the authors hypothesize that lipoproteins modulate the atherogenic process by affecting blood viscosity. In order to define the magnitude of the effect of lipoproteins on blood viscosity, capillary viscometry was performed on blood from 16 healthy, fasting...
Article
Two morphologic patterns of fatty streak were identified on examination of 74 aortas from the Pathobiological Determinants of Atherosclerosis in Youth study. Pattern 1, which predominated in 78% of aortas, is characterized by broad bands of intense stain which extend to the proximal edge of ostia. Pattern 2, which predominated in 11%, is characteri...
Article
The hemorheologic-hemodynamic theory of atherogenesis suggests that atherosclerosis is a disease of low shear, which prolongs the residence time of atherogenic particles on the endothelium. Prolonged residence of lipid-rich particles results in a fatty streak. Prolonged residence of platelet microthrombi results in a raised lesion (atherosclerotic...
Article
To determine the effect of long-term aspirin therapy on the prevalence of symptomatic atherosclerosis, autopsy results from 44 arthritis patients taking aspirin were compared with a cohort from the general autopsy population. No decrease in the prevalence of symptomatic atherosclerosis was noted in patients with less than 8 years of arthritis, comp...
Article
Sir,—As Meyers et al note, data regarding the iron hypothesis of atherogenesis are inconsistent,1 and data regarding the closely allied oxidation hypothesis are also conflicting.2 Thus, I suggest that the beneficial effect of blood donation on cardiovascular disease is caused by a reduction in haematocrit and blood viscosity. Haematocrit was shown...
Article
Previous studies from this laboratory have demonstrated, in a rabbit model of keratitis, a relationship between the corneal virulence of Staphylococcus aureus and the alpha-toxin activity of the infecting bacteria. This study is a histopathological characterization of the action of purified alpha-toxin on corneal tissue. Alpha-toxin was purified by...
Article
The author proposes that all major risk factors, including elevated serum low-density lipoprotein, cause atherosclerosis by increasing viscosity, creating larger areas of decreased blood flow, thereby perpetuating the interaction of atherogenic elements with the endothelium. Low-density lipoprotein causes increased viscosity by fostering erythrocyt...
Article
Severe transfusion reactions occur much less often than minor reactions, but it is difficult to discriminate clinically between impending severe reactions and minor reactions. Therefore, whenever a reaction occurs, the transfusion should be discontinued and a laboratory workup initiated to rule out an acute hemolytic transfusion reaction. At a mini...
Article
We report a case of type I cryoglobulinemia with cold agglutinin activity complicating allogeneic bone marrow transplantation. To our knowledge, this complication has not been previously reported. We also discuss possible etiologic mechanisms for this unusual event.

Questions

Questions (3)
Question
I didn't receive training in the scientific method and had to teach myself about Sir Karl Popper and Thomas Kuhn. I was a medical student, so that's not surprising. But graduate students at the school where I was faculty didn't either. My impression is that students are not formally introduced to the scientific method.
Question
I wonder if concern for possible adverse effects on health has limited utilization of interesterification technology.
Question
This question is inspired by the debate over the eficacy (or lack thereof) of statins in response to Max Chartrand's question, "If recent research demonstrates that synthetic statins pose higher risks than earlier reported, what are the best solutions for optimal health?"  Fifty percent of myocardial infarctions occur in subjects without overt hyperlipidemia, and 20% of MI's occur in the absence of any classic risk factors?  So far, cholesteryl ester transfer protein inhibitors have flopped in a major way, at the development cost of hundreds of millions of dollars.  Do you think atherogenesis is really understood?

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