Citations

Background: Arsenic is a well-known toxin which may contaminate household water. It is harmful when ingested over prolonged periods of time. As a result, public health experts recommend that water should be screened and treated to prevent arsenic ingestion. In the United States, the responsibility of testing and treatment of private wells falls on homeowners. Despite recommendations for routine screening, this is rarely done. Objectives: To assess the prevalence of well water use in a Midwestern patient population, how patients and clinicians perceive the risks of arsenic in well water, and whether additional resources on well water testing are desired. These findings will be used to influence tools for clinicians regarding symptom and examination findings of chronic arsenic exposure and potentiate the distribution of informational resources on well water testing. Methods: Surveys were sent via email to all actively practicing primary care clinicians at the Mayo Clinic in the United States Midwest, and all active adult patients at the Mayo Clinic in the same region. Our team analyzed survey data to determine whether both patients and clinicians are aware of the health effects of chronic arsenic toxicity from well water, the need for routine well water testing and whether each group wants more information on the associated risks. Results: Both patients and primary care clinicians worry about arsenic exposure. Patients with well water are concerned about their water safety yet feel uninformed about testing options. Clinicians do not know how prevalent well water use is among their patients, feel uninformed about the chronic risks of arsenic exposure and the physical examination associated with it. Both groups unanimously want more information on testing options. Conclusions: Our findings show a significant reliance on well water use in the American Midwest, and unanimous support for the need for further well water testing information and resources for patients and their clinicians.

Abstract Objective . This study characterized optically-stimulated luminescent dosimeter (OSLD) nanoDots for use in a therapeutic carbon beam using the Imaging and Radiation Oncology Core (IROC) framework for remote output verification. Approach . The absorbed dose correction factors for OSLD (fading, linearity, beam quality, angularity, and depletion), as defined by AAPM TG 191, were characterized for carbon beams. For the various correction factors, the effect of linear energy transfer (LET) was examined by characterizing in both a low and high LET setting. Main results . Fading was not statistically different between reference photons and carbon, nor between low and high LET beams; thus, the standard IROC-defined exponential function could be used to characterize fading. Dose linearity was characterized with a linear fit; while low and high LET carbon linearity was different, these differences were small and could be rolled into the uncertainty budget if using a single linearity correction. A linear fit between beam quality and dose-averaged LET was determined. The OSLD response at various angles of incidence was not statistically different, thus a correction factor need not be applied. There was a difference in depletion between low and high LET irradiations in a primary carbon beam, but this difference was small over the standard five readings. The largest uncertainty associated with the use of OSLDs in carbon was because of the k Q correction factor, with an uncertainty of 6.0%. The overall uncertainty budget was 6.3% for standard irradiation conditions. Significance . OSLD nanoDot response was characterized in a therapeutic carbon beam. The uncertainty was larger than for traditional photon applications. These findings enable the use of OSLDs for carbon absorbed dose measurements, but with less accuracy than conventional OSLD audit programs.

Site specific targeting remains an elusive goal for stem cell and gene therapies in the cardiovascular field. One promising option involves use of modified 3D stent designs that deliver larger cell/gene payloads to specific disease sites using the versatility of percutaneous vascular access. Here, we engineered smooth muscle cells (SMCs) placed in a 3D metallic stent scaffold to deliver high local concentrations of an angiogenic gene (VEGF165) in a porcine model of chronic total occlusion involving ameroid placement on the proximal left circumflex (LCx) artery(n≥8 per group). Engineered SMCs were retained within the mesh stent structure (479 ± 47.4 SMC/mm2) and were competent for VEGF production in vitro (8.8 ± 1.8 ng/ml in media). Following implantation, micro CT analyses revealed that stents loaded with VEGF producing SMCs significantly enhanced vasa vasora microvessel density (5.43 ± 0.46 vs 2.14 ± 0.19 vessels/mm2, p<0.001) with a concomitant increase in tissue VEGF protein levels (277.9 ± 85.7 vs 18.8 ± 4.4 pg/mg protein, p<0.0001). Formation of endothelial cell colonies from peripheral blood mononuclear cells was significantly increased with the implantation of VEGF-secreting cells suggesting increased angiogenic potential (7.0 ± 2.0 versus 41.6 ± 4.5, EC:CFU p<0.0001). VEGF secreting mesh stent placement enhanced regional blood flow analyses determined by microsphere analyses as well as improving regional wall motion in the LCx-related territory (p<0.05) as well as left ventricular function assessed in terms of ejection fraction (34.2 ± 6.7% vs 61.2 ± 5.2% P<0.001) and dp/dt (p<0.001) Our data indicate robust clinically relevant angiogenesis can be achieved in a human scale porcine chronic vascular occlusion model following stent based delivery of angiogenic cells. This may have implications for percutaneous delivery of stem cells, genes and secreted therapeutic factors in cardiovascular disease in general and in creation of percutaneous microvascular bypass networks in the setting of chronic vaso-occlusive disease in particular.

Background: The extent to which tissue factor pathway inhibitor (TFPI) may regulate the extrinsic clotting cascade, atherogenesis, and MI is uncertain. Reverse genetic studies in the mouse, including deletion of the TFPI Kunitz-1 (K1) domain, have been hindered by intrauterine lethality. We sought to determine the role of TFPI in an alternative animal model, by knocking out the zebrafish ortholog tfpia . Methods and results: High-efficiency transcription activator-like effector nucleases (TALENs), targeting the 5’ region of tfpia, were microinjected into 1-cell zebrafish embryos. Sequence analysis of genomic DNA derived from adult caudal fin tissue revealed indels causing a frameshift mutation and premature stop codon prior to K1. Somatic mutants were outcrossed to WT fish, and the embryos were screened for germline mutations. Founders (F 1 ) were raised and incrossed to produce embryos (F 2 ), including approximately 25% with the desired biallelic null mutation ( tfpia -/- ) that were physically and developmentally indistinguishable, but functionally disparate from heterozygous ( tfpia +/- ) or WT ( tfpia +/+ ) siblings. At 6 days post-fertilization (dpf), F 2 tfpia -/- larvae exhibited a reduction in time to occlusion of the dorsal aorta after exposure to ferric chloride, which was more significant in 6-dpf F 3 tfpia -/- larvae (generated by incrossing F 2 tfpia -/- adults) lacking a possible maternal effect. Furthermore, F 2 tfpia -/- fish had in vivo evidence of increased fatty streaking as late larvae, after receiving a high cholesterol diet, and enhanced cardiac injury as adults, 4 days after cryoinjury-induced MI. Conclusions: Deletion of tfpia does not significantly effect zebrafish development, but leads to hypercoagulability in early larvae, enhanced atherogenesis in late larvae, and increased injury related to MI in adults, indicating a fundamental role for TFPI in the pathogenesis of cardiovascular disease.

Introduction: Hydrochlorothiazide (HCTZ) is among the most commonly prescribed antihypertensives in the US, yet <50% of HCTZ treated patients achieve blood pressure (BP) control. Hypothesis: Integrating metabolomic and genomic profiles of HCTZ treated patients could identify novel pathways/biomarkers for optimizing the use of HCTZ. Methods: Primary analysis included 228 white hypertensives treated with HCTZ from the Pharmacogenomic Evaluation of Antihypertensive Response (PEAR) study. Genotyping was determined via Illumina Omni 1M-Quad Chip and untargeted metabolomics was performed on baseline fasting plasma samples using a GC-TOF MS platform. Pathway analysis was used to integrate metabolites significantly associated with HCTZ BP response (FDR<.05) and genetic signals at p<5x10-5 from HCTZ BP genome-wide analysis. Replication was conducted in another 212 white HCTZ treated patients. Replicated genetic signals were used to create a BP response score by summing their BP lowering alleles. We validated this score by testing it in 196 white HCTZ treated patients in the Genetic Epidemiology of Responses to Antihypertensives (GERA) study. Results: Thirteen metabolites were significantly associated with HCTZ systolic BP (SBP) and diastolic BP (DBP) responses (FDR<.05). Metabolomics-genomics integration revealed significant metabolites along with rs2727563 PRKAG2, rs12604940 DCC, and rs13262930 EPHX2, in the netrin signalling pathway (p=1x10-5), as potential markers significantly influencing HCTZ BP response. We successfully replicated those 3 genetic signals and added their alleles to create a response score which explained 11.3% and 11.9% of the variability to HCTZ SBP and DBP responses, respectively. We found that patients carrying one “response” allele had a significantly worse response than carriers of six alleles (ΔSBP/ΔDBP: -1.5/1.2 vs -16.3/-10.4 mmHg, respectively, SBP score p=1x10-8 and DBP score p=3x10-9). We further validated this response score by testing it in the GERA (DBP score p=0.03, SBP score p=0.07). Conclusion: This study highlights the power of using different omics to identify novel pathways/biomarkers of drug response, and suggests that PRKAG2, DCC and EPHX2 might be important determinants of HCTZ BP response.

Background: As the United States medical system transitions to value-based reimbursement, interested parties will increase scrutiny in testing that may not alter management or outcomes. We investigated whether transesophageal echocardiography (TEE) provokes treatment alteration across age strata in hospitalized patients undergoing a TIA/stroke work-up. Methods: Consecutive patients admitted to the Mayo Clinic Arizona healthcare system between 1/1/2010 and 2/9/2015 were evaluated. A total of 832 patients were identified of which 314 were excluded primarily due to the fact that the TEE was performed as an outpatient. Therefore, 518 subjects (mean age = 68.2 +/- 14.1 y, 42.5% female) were included. A change in treatment was defined a priori as: anticoagulation (AC) initiated for atrial fibrillation found on TEE only (i.e. not identified on telemetry), complex proximal aortic arch plaque, left atrial or left atrial appendage thrombus, intracardiac mass, intracardiac shunt (atrial septal defect (ASD)/ patent foramen ovale (PFO)) ; PFO closure; cardiac mass removal; valve replacement for endocarditis; antibiotics for endocarditis. Results: See Tables A & B Conclusion: TEE in the evaluation of hospitalized patients with TIA/stroke resulted in a change in treatment in approximately 7% of patients regardless of age. Many of the decisions to change treatment were judgment-based and therefore adoption of the routine use of TEE in all patients with TIA/stroke is dependent on institutional practice standards.

Introduction Current evidence suggests that abnormal ventriculo-vascular coupling may contribute to the development of atrial fibrillation (AF) by increasing ventricular filling pressures and consequently, left atrial pressure. Recent investigations have also suggested that inflammation might have a role in the pathophysiology of AF. We hypothesize that autoimmune vasculitis plays a significant role in the pathogenetic mechanism of AF. Methods In this longitudinal cohort study, residents of Olmsted County, MN with first- time diagnosed AF during 1980-2000 and a reference age- and sex-matched control group from the same underlying population and time period were identified and followed until death, or 2000. The relationship between autoimmune vasculitis and first documented AF was analyzed. Results Of a total of 8766 patients (mean age 61.1+14.9 years; 56% women), 691 (7.9%) were diagnosed with autoimmune vasculitis during the 20 year period. The prevalence of autoimmune vasculitis in the AF group was 9.9% and 5.9% in the control group; p <0.001, respectively. After adjusting for CAD and LV dysfunction, the odds of autoimmune vasculitis in AF was 1.7 times higher than in controls (OR 1.69, 95%; CI 1.42 - 2.01, p < 0.0001). AF patients with autoimmune vasculitis had a worse survival compared to controls; p=.0114 (log-rank test). Conclusion Autoimmune vasculitis strongly increases the risk of atrial fibrillation and portends shorter survival in the AF population. These observations may represent one mechanism linking increased arterial stiffness and inflammation in the pathogenesis and prognosis of AF as an age-related disorder.

Introduction: Cardiac veins serve as substrate for arrhythmogenesis, and are especially involved as foci in atrial fibrillation. Understanding cardiac vein anatomy along with myocardial extension into these structures can improve electrophysiological mapping and electrical isolation of arrhythmogenic substrate. Accurately defining cardiac vein anatomy is critical in improving success of ablation therapy for atrial fibrillation. Methods: We performed measurements on 620 formalin-fixed autopsy hearts explanted from October 1998 to July 2003. The integrity of the thoracic veins and their cardiac connections were examined and systematic measurements of the superior and inferior vena cavae, azygous vein, vein of Marshall, coronary sinus, and pulmonary veins were performed and data were analyzed using univariate statistics. Results: We found that muscular extensions into the pulmonary veins were visible in 99% of the examined hearts, and were circumferential around the vein ostia (99.6%). Muscle extension into the SVC was found in 78% of examined hearts. These extensions were largely circumferential around the ostium (39%), but were also found to be asymmetric in a majority of hearts. Asymmetry was found in hearts with longer muscle extensions; no symmetry was observed in extensions greater than 0.8cm. Muscle extensions into the IVC were not seen. Occasionally, macroscopic muscle extensions into the azygous vein were visible (6%). The vein of Marshall was found to be patent to probing in the majority of hearts examined (72%) and was almost always overlying the lateral left atrial endocardial ridge. Conclusions: Our data suggest that all pulmonary veins need to be electrically isolated during atrial fibrillation ablation because of the almost universal presence of myocardial tissue extending into the veins. Mapping of the SVC should be done circumferentially and if potentials are noted isolation should also be performed. The IVC did not have muscle extensions and is unlikely to be a site of arrhythmogenesis. The azygous vein occasionally had muscle extensions and thus requires mapping and possible isolation. The vein of Marshall can be a substrate for arrhythmogenesis and is accessible for ablation by targeting the lateral left atrial endocardial ridge.

Background: The tissue factor pathway regulates vascular structure in the adult through regulation of thrombin generation and signaling. Deletion of tissue factor pathway inhibitor (TFPI) in the mouse results in early intrauterine lethality, precluding study of vascular development. In addition, the carboxyl terminus of TFPI may have a TF-independent effect on vascular structure. We sought to determine the role of TFPI and its carboxyl terminus in vascular development of zebrafish. Methods and results: TFPI mRNA localization studies demonstrated expression in the developing kidney, gut, and vasculature of the zebrafish. We further assessed the role of TFPI in zebrafish angiogenesis, by injecting translational and splice-inhibiting morpholino (MO) oligonucleotides directed against zebrafish TFPI mRNA into embryos from the double transgenic zebrafish Tg(Fli1GFP); Tg(GATA1dsRed) expressing GFP in vascular endothelium and dsRed in erythroid cells. Knockdown of TFPI protein expression was subsequently confirmed by immunoblotting. In a dose-dependent manner, multiple non-overlapping MOs targeting the translation initiation site of TFPI independently and synergistically led to the formation of abnormally targeted intersegmental arteries which crossed somite boundaries by 48 hours post fertilization (hpf). Additionally, a plethoric caudal vein plexus with increased honeycombing was present by 24 hpf. This latter aspect of the phenotype was most striking after a MO targeted against a splice site involving the Kunitz 3 and carboxyl terminus domains of zebrafish TFPI was injected alone. Conclusions: TFPI is expressed during zebrafish development. Morpholino knockdown of TFPI expression alters both arterial and venous patterning in the developing zebrafish, indicating a fundamental role for TFPI in targeting of newly-formed blood vessels. Moreover, different domains of the TFPI protein may preferentially act on distinct vascular networks.