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Sample records for flow-mediated dilation relation

  1. Treatment of denture-related stomatitis improves endothelial function assessed by flow-mediated vascular dilation.

    PubMed

    Osmenda, Grzegorz; Maciąg, Joanna; Wilk, Grzegorz; Maciąg, Anna; Nowakowski, Daniel; Loster, Jolanta; Dembowska, Elżbieta; Robertson, Douglas; Guzik, Tomasz; Cześnikiewicz-Guzik, Marta

    2017-02-01

    The presence of oral inflammation has recently been linked with the pathogenesis of cardiovascular diseases. While numerous studies have described links between periodontitis and endothelial dysfunction, little is known about the influence of denture-related stomatitis (DRS) on cardiovascular risk. Therefore, the aim of this study was to determine whether the treatment of DRS can lead to improvement of the clinical measures of vascular dysfunction. The DRS patients were treated with a local oral antifungal agent for 3 weeks. Blood pressure, flow-mediated dilatation (FMD) and nitroglycerine-mediated vascular dilatation (NMD) were measured during three study visits: before treatment, one day and two months after conclusion of antifungal therapy. Flow-mediated dilatation measurements showed significant improvement of endothelial function 2 months after treatment (FMD median 5%, 95 CI: 3-8.3 vs. 11%, 95% CI: 8.8-14.4; p < 0.01), while there was no difference in control, endothelium-independent vasorelaxations (NMD; median = 15.3%, 95% CI: 10.8-19.3 vs. 12.7%, 95% CI: 10.6-15; p = 0.3). Other cardiovascular parameters such as systolic (median = 125 mm Hg; 95% CI: 116-129 vs. 120 mm Hg, 95% CI: 116-126; p = 0.1) as well as diastolic blood pressure and heart rate (median = 65.5 bpm, 95% CI: 56.7-77.7 vs. 71 bpm, 95% CI: 66.7-75; p = 0.5) did not change during or after the treatment. Treatment of DRS is associated with improvement of endothelial function. Since endothelial dysfunction is known to precede the development of severe cardiovascular disorders such as atherosclerosis and hypertension, patients should be more carefully screened for DRS in general dental practice, and immediate DRS treatment should be advised.

  2. Treatment of denture-related stomatitis improves endothelial function assessed by flow-mediated vascular dilation

    PubMed Central

    Osmenda, Grzegorz; Maciąg, Joanna; Wilk, Grzegorz; Maciąg, Anna; Nowakowski, Daniel; Loster, Jolanta; Dembowska, Elżbieta; Robertson, Douglas; Guzik, Tomasz

    2016-01-01

    Introduction The presence of oral inflammation has recently been linked with the pathogenesis of cardiovascular diseases. While numerous studies have described links between periodontitis and endothelial dysfunction, little is known about the influence of denture-related stomatitis (DRS) on cardiovascular risk. Therefore, the aim of this study was to determine whether the treatment of DRS can lead to improvement of the clinical measures of vascular dysfunction. Material and methods The DRS patients were treated with a local oral antifungal agent for 3 weeks. Blood pressure, flow-mediated dilatation (FMD) and nitroglycerine-mediated vascular dilatation (NMD) were measured during three study visits: before treatment, one day and two months after conclusion of antifungal therapy. Results Flow-mediated dilatation measurements showed significant improvement of endothelial function 2 months after treatment (FMD median 5%, 95 CI: 3–8.3 vs. 11%, 95% CI: 8.8–14.4; p < 0.01), while there was no difference in control, endothelium-independent vasorelaxations (NMD; median = 15.3%, 95% CI: 10.8–19.3 vs. 12.7%, 95% CI: 10.6–15; p = 0.3). Other cardiovascular parameters such as systolic (median = 125 mm Hg; 95% CI: 116–129 vs. 120 mm Hg, 95% CI: 116–126; p = 0.1) as well as diastolic blood pressure and heart rate (median = 65.5 bpm, 95% CI: 56.7–77.7 vs. 71 bpm, 95% CI: 66.7–75; p = 0.5) did not change during or after the treatment. Conclusions Treatment of DRS is associated with improvement of endothelial function. Since endothelial dysfunction is known to precede the development of severe cardiovascular disorders such as atherosclerosis and hypertension, patients should be more carefully screened for DRS in general dental practice, and immediate DRS treatment should be advised. PMID:28144257

  3. [Analysis of differences in flow-mediated dilation in relation to the treatment of coronary patients].

    PubMed

    Novo García, Enrique; Balaguer, Javier; Jiménez, Eulalia; García Lledó, Alberto; Caballero, Manuela; Chaparro, Manuel

    2003-02-01

    Flow-mediated dilation (FMD) is thought to be related to the development of coronary disease. We were interested in knowing the degree of FMD in a large sample of coronary patients in relation to the therapy they were given in clinical practice. We studied 1,081 coronary patients (age 68 +/- 12 years, 73% male) in which FMD was evaluated in the brachial artery. The patients were classified into 5 treatment groups (416 who receive 2 or more treatments were excluded): group A: 81 controls treated with aspirin, group B: 198 treated with ACE inhibitors, group C: 106 with calcium antagonists, group D: 145 with beta-blockers, and group E: 135 with lipid lowering medication (93% statins). ANOVA was used to analyze the differences between groups. With regard to the number of risk factors present in each group, the patients treated with ACE inhibitors (2.44 +/- 0.79 vs 2.14 +/- 0.89; p < 0.05) and statins (3.45 +/- 0.70 vs 2.14 +/- 0.89; p < 0.05) had more risk factors than GrA and higher levels of LDL-cholesterol (ACE inhibitors 145.0 +/- 33.5 vs 128.5 +/- 32.2 and statins 157.8 +/- 45.3 vs 128.5 +/- 32.2; p < 0.05). GrB had a higher glycemia than controls (123.4 +/- 32.2 vs 114.7 +/- 33.7; p < 0.05). The control group was younger than the therapeutic groups (p < 0.05). Compared with the control group, FMD was significantly higher only in the group treated with ACE inhibitors (3.42 +/- 6.01 vs 0.82 +/- 6.04; p < 0.05). Multivariate logistical regression showed that treatment with ACE inhibitors and statins (p < 0.05) were independent predictors of FMD > 4%. Treatment with ACE inhibitors or statins was predictive of the normalization of FMD in coronary patients in clinical practice.

  4. Relation of Biochemical Parameters with Flow-mediated Dilatation in Patients with Metabolic Syndrome

    PubMed Central

    Sipahioglu, Nurver Turfaner; Ilerigelen, Barıs; Gungor, Zeynep B.; Ayaz, Gulsel; Ekmekci, Hakan; Gurel, Cigdem Bayram; Can, Gunay; Sonmez, Huseyin; Ulutin, Turgut; Sipahioglu, Fikret

    2017-01-01

    Background: Metabolic syndrome (MetS) is one of the high cardiovascular (CV) situations. Endothelial dysfunction, which is a common finding in patients with MetS, is related with increased CV risk. In patients with MetS, the effect of the major CV risk factors, not included in the MetS definition, on endothelial dysfunction is not well known. The aim of this study was to determine the effect of major CV risk factors such as gender, smoking, family history, and biochemical parameters on endothelial dysfunction in patients with MetS. Methods: The study was performed between December 2010 and August 2014. A total of 55 patients (15 females and 40 males) with MetS and 81 healthy controls (37 females and 44 males) with a body mass index <25 kg/m2 were enrolled in the study. Endothelial dysfunction was measured by flow-mediated dilatation (FMD), oxidative stress parameters; high-sensitivity C-reactive protein (hs-CRP), oxidized low-density lipoprotein (ox-LDL), endothelial nitric oxide synthase (e-NOS), nitric oxide, and cell adhesion markers; von Willebrand factor, and e-selectin. Platelet aggregation (endothelial adenosine diphosphate), total platelet count, and mean platelet volume were additionally analyzed and demographic parameters were explored. Student's t-test, Mann-Whitney U-test, and Chi-square test were used to analyze the results. Results: The fasting blood glucose (z = 3.52, P = 0.001), hs-CRP (z = 3.23, P = 0.004), ox-LDL (z = 2.62, P = 0.013), and e-NOS (z = 2.22, P = 0.026) levels and cardiac risk score (z = 5.23, P < 0.001) were significantly higher in patients with MetS compared with the control group. Smoking was correlated with decreased FMD (χ2 = 9.26, P = 0.002) in MetS patients but not in the control group. Conclusions: Increased ox-LDL, hs-CRP, and e-NOS are likely to be a result of oxidative stress, a condition in which an imbalance occurs between the production and inactivation of reactive nitrogen and oxygen species. In addition, in patients

  5. Relations of Arterial Stiffness and Brachial Flow-Mediated Dilation With New-Onset Atrial Fibrillation: The Framingham Heart Study.

    PubMed

    Shaikh, Amir Y; Wang, Na; Yin, Xiaoyan; Larson, Martin G; Vasan, Ramachandran S; Hamburg, Naomi M; Magnani, Jared W; Ellinor, Patrick T; Lubitz, Steven A; Mitchell, Gary F; Benjamin, Emelia J; McManus, David D

    2016-09-01

    The relations of measures of arterial stiffness, pulsatile hemodynamic load, and endothelial dysfunction to atrial fibrillation (AF) remain poorly understood. To better understand the pathophysiology of AF, we examined associations between noninvasive measures of vascular function and new-onset AF. The study sample included participants aged ≥45 years from the Framingham Heart Study offspring and third-generation cohorts. Using Cox proportional hazards regression models, we examined relations between incident AF and tonometry measures of arterial stiffness (carotid-femoral pulse wave velocity), wave reflection (augmentation index), pressure pulsatility (central pulse pressure), endothelial function (flow-mediated dilation), resting brachial arterial diameter, and hyperemic flow. AF developed in 407/5797 participants in the tonometry sample and 270/3921 participants in the endothelial function sample during follow-up (median 7.1 years, maximum 10 years). Higher augmentation index (hazard ratio, 1.16; 95% confidence interval, 1.02-1.32; P=0.02), baseline brachial artery diameter (hazard ratio, 1.20; 95% confidence interval, 1.01-1.43; P=0.04), and lower flow-mediated dilation (hazard ratio, 0.79; 95% confidence interval, 0.63-0.99; P=0.04) were associated with increased risk of incident AF. Central pulse pressure, when adjusted for age, sex, and hypertension (hazard ratio, 1.14; 95% confidence interval, 1.02-1.28; P=0.02) was associated with incident AF. Higher pulsatile load assessed by central pulse pressure and greater apparent wave reflection measured by augmentation index were associated with increased risk of incident AF. Vascular endothelial dysfunction may precede development of AF. These measures may be additional risk factors or markers of subclinical cardiovascular disease associated with increased risk of incident AF. © 2016 American Heart Association, Inc.

  6. Aerobic Capacity and Postprandial Flow Mediated Dilation.

    PubMed

    Ballard, Kevin D; Miller, James J; Robinson, James H; Olive, Jennifer L

    The consumption of a high-fat meal induces transient vascular dysfunction. Aerobic exercise enhances vascular function in healthy individuals. Our purpose was to determine if different levels of aerobic capacity impact vascular function, as measured by flow mediated dilation, following a high-fat meal. Flow mediated dilation of the brachial artery was determined before, two- and four-hours postprandial a high-fat meal in young males classified as highly trained (n = 10; VO2max = 74.6 ± 5.2 ml·kg·min(-1)) or moderately active (n = 10; VO2max = 47.3 ± 7.1 ml·kg·min(-1)). Flow mediated dilation was reduced at two- (p < 0.001) and four-hours (p < 0.001) compared to baseline for both groups but was not different between groups at any time point (p = 0.108). Triglycerides and insulin increased at two- (p < 0.001) and four-hours (p < 0.05) in both groups. LDL-C was reduced at four-hours (p = 0.05) in highly trained subjects, and two- and four-hours (p ≤ 0.01) in moderately active subjects. HDL-C decreased at two- (p = 0.024) and four-hours (p = 0.014) in both groups. Glucose increased at two-hours postprandial for both groups (p = 0.003). Our results indicate that a high-fat meal results in reduced endothelium-dependent vasodilation in highly trained and moderately active individuals with no difference between groups. Thus, high aerobic capacity does not protect against transient reductions in vascular function after the ingestion of a single high-fat meal compared to individuals who are moderately active.

  7. ULTRASOUND ASSESSMENT OF FLOW-MEDIATED DILATION: A TUTORIAL

    PubMed Central

    Harris, Ryan A.; Nishiyama, Steven K.; Wray, D. Walter; Richardson, Russell S.

    2010-01-01

    Developed in 1992, the flow-mediated dilation test is now the most commonly utilized non-invasive assessment of vascular endothelial function in humans. Since its inception, scientists have refined their understanding of the physiology, analysis, and interpretation of this measurement. Recently, a significant growth of knowledge has added to our understanding and implementation of this clinically relevant research methodology. Therefore, this tutorial provides timely insight into recent advances and practical information related to the ultrasonic assessment of vascular endothelial function in humans. PMID:20351340

  8. Impairment of flow-mediated dilation correlates with aortic dilation in patients with Marfan syndrome.

    PubMed

    Takata, Munenori; Amiya, Eisuke; Watanabe, Masafumi; Omori, Kazuko; Imai, Yasushi; Fujita, Daishi; Nishimura, Hiroshi; Kato, Masayoshi; Morota, Tetsuro; Nawata, Kan; Ozeki, Atsuko; Watanabe, Aya; Kawarasaki, Shuichi; Hosoya, Yumiko; Nakao, Tomoko; Maemura, Koji; Nagai, Ryozo; Hirata, Yasunobu; Komuro, Issei

    2014-07-01

    Marfan syndrome is an inherited disorder characterized by genetic abnormality of microfibrillar connective tissue proteins. Endothelial dysfunction is thought to cause aortic dilation in subjects with a bicuspid aortic valve; however, the role of endothelial dysfunction and endothelial damaging factors has not been elucidated in Marfan syndrome. Flow-mediated dilation, a noninvasive measurement of endothelial function, was evaluated in 39 patients with Marfan syndrome. Aortic diameter was measured at the aortic annulus, aortic root at the sinus of Valsalva, sinotubular junction and ascending aorta by echocardiography, and adjusted for body surface area (BSA). The mean value of flow-mediated dilation was 6.5 ± 2.4 %. Flow-mediated dilation had a negative correlation with the diameter of the ascending thoracic aorta (AscAd)/BSA (R = -0.39, p = 0.020) and multivariate analysis revealed that flow-mediated dilation was an independent factor predicting AscAd/BSA, whereas other segments of the aorta had no association. Furthermore, Brinkman index had a somewhat greater influence on flow-mediated dilation (R = -0.42, p = 0.008). Although subjects who smoked tended to have a larger AscAd compared with non-smokers (AscA/BSA: 17.3 ± 1.8 versus 15.2 ± 3.0 mm/m(2), p = 0.013), there was no significant change in flow-mediated dilation, suggesting that smoking might affect aortic dilation via an independent pathway. Common atherogenic risks, such as impairment of flow-mediated dilation and smoking status, affected aortic dilation in subjects with Marfan syndrome.

  9. Relation of high cytomegalovirus antibody titres to blood pressure and brachial artery flow-mediated dilation in young men: the Cardiovascular Risk in Young Finns Study.

    PubMed

    Haarala, A; Kähönen, M; Lehtimäki, T; Aittoniemi, J; Jylhävä, J; Hutri-Kähönen, N; Taittonen, L; Laitinen, T; Juonala, M; Viikari, J; Raitakari, O T; Hurme, M

    2012-02-01

    Human cytomegalovirus (CMV) infection is associated with a higher risk of cardiovascular disease in immunocompromised organ transplant patients. It has been linked with the pathogenesis of elevated arterial blood pressure. However, controversy exists as to whether CMV infection is associated with endothelial function, and little is known about its role as a potential risk factor for early atherosclerosis development at a young age. We aimed to discover if CMV antibody titres are associated with early vascular changes (carotid intima-media thickness, carotid artery distensibility and brachial artery flow-mediated dilation), blood pressure elevation or other traditional cardiovascular risk factors. CMV antibody titres were measured in 1074 women and 857 men (aged 24-39 years) taking part in the Cardiovascular Risk in Young Finns study. CMV antibody titres were significantly higher in women compared to men. In men, high CMV antibody titres were associated directly with age (P < 0·001) and systolic (P = 0·053) and diastolic (P = 0·002) blood pressure elevation, and associated inversely with flow-mediated dilation (P = 0·014). In women, CMV antibody titres did not associate with any of the analysed parameters. In a multivariate regression model, which included traditional atherosclerotic risk factors, CMV antibody titres were independent determinants for systolic (P = 0·029) and diastolic (P = 0·004) blood pressure elevation and flow-mediated dilation (P = 0·014) in men. High CMV antibody titres are associated independently with blood pressure and brachial artery flow-mediated dilation in young men. This association supports the hypothesis that common CMV infection and/or an immune response to CMV may lead to impaired vascular function at a young age. © 2012 The Authors. Clinical and Experimental Immunology © 2012 British Society for Immunology.

  10. Relations among Adiposity and Insulin Resistance with Flow-Mediated Dilation, Carotid Intima-Media Thickness, and Arterial Stiffness in Children

    PubMed Central

    Ryder, Justin R.; Dengel, Donald R.; Jacobs, David R.; Sinaiko, Alan; Kelly, Aaron S.; Steinberger, Julia

    2015-01-01

    Objective To determine the associations of adiposity and insulin resistance with measures of vascular structure and function in children. Study design A cross-sectional study included 252 children (age 15.1±2.4 yrs; body mass index (BMI)-percentile 68.2±26.5%; Tanner 2–5). Measurements of body fat percentage (BF%) were obtained with dual-energy X-ray absorptiometry (DXA) and visceral fat (VAT) with computed tomography (CT). Insulin resistance was measured with hyperinsulinemic euglycemic clamp. Vascular measurements for endothelial function (brachial artery flow-mediated dilation [FMD]), vascular structure (carotid intima-media thickness [cIMT]), vascular stiffness (carotid incremental elastic modulus [cIEM]), and pulse wave velocity (PWV) were analyzed by tertiles of adiposity and insulin resistance. Additional analyses with ANCOVA and linear regression, were adjusted for Tanner, sex, race, and family relationship; FMD was also adjusted for baseline artery diameter. Results FMD was positively associated with high adiposity (BMI, BF%, and VAT) (p<0.01 all). Insulin resistance was not associated with FMD. cIMT was significantly, positively related to obesity, VAT, and insulin resistance (p<0.05 all). No differences in cIEM and PWV were observed in relation to adiposity or insulin resistance. Conclusions The findings suggest that adiposity is associated with higher FMD, and insulin resistance and VAT are associated with higher cIMT in children. Further research is needed to clarify the progression of these relations. PMID:26427963

  11. The Importance of Velocity Acceleration to Flow-Mediated Dilation

    PubMed Central

    Stoner, Lee; Young, Joanna M.; Fryer, Simon; Sabatier, Manning J.

    2012-01-01

    The validity of the flow-mediated dilation test has been questioned due to the lack of normalization to the primary stimulus, shear stress. Shear stress can be calculated using Poiseuille's law. However, little attention has been given to the most appropriate blood velocity parameter(s) for calculating shear stress. The pulsatile nature of blood flow exposes the endothelial cells to two distinct shear stimuli during the cardiac cycle: a large rate of change in shear at the onset of flow (velocity acceleration), followed by a steady component. The parameter typically entered into the Poiseuille's law equation to determine shear stress is time-averaged blood velocity, with no regard for flow pulsatility. This paper will discuss (1) the limitations of using Posieuille's law to estimate shear stress and (2) the importance of the velocity profile—with emphasis on velocity acceleration—to endothelial function and vascular tone. PMID:22315688

  12. Relation of nonalcoholic fatty liver disease and Framingham Risk Score to flow-mediated dilation in patients with cardiometabolic risk factors.

    PubMed

    Pastori, Daniele; Loffredo, Lorenzo; Perri, Ludovica; Baratta, Francesco; Scardella, Laura; Polimeni, Licia; Pani, Arianna; Brancorsini, Monica; Albanese, Fabiana; Catasca, Elisa; Del Ben, Maria; Violi, Francesco; Angelico, Francesco

    2015-05-15

    Nonalcoholic fatty liver disease (NAFLD) has a high prevalence in the general population. Brachial artery flow-mediated dilation (FMD) is a surrogated marker of early atherosclerosis. Few data investigating the relation between FMD, NAFLD, and cardiovascular (CV) risk are available. We recruited 367 consecutive outpatients with cardiometabolic risk factors who underwent ultrasound scanning for liver steatosis and FMD. Mean age was 54.2 ± 12.2 years, and 37% were women. NAFLD was present in 281 patients (77%). Median FMD was 5.1%. FMD was significantly reduced in patients with NAFLD (p <0.001), diabetes (p = 0.001), history of coronary heart disease (p = 0.034), and metabolic syndrome (p = 0.050) and in those taking antihypertensive drugs (p = 0.022). Women disclosed greater FMD than males (p = 0.033). Moreover, FMD inversely correlated with age (Spearman rank correlation test [Rs], -0.171; p = 0.001), waist circumference (Rs, -0.127; p = 0.016), fasting blood glucose (Rs, -0.204; p <0.001), and gamma-glutamyl transpeptidase (Rs, -0.064; p = 0.234). At multivariate regression analysis, fasting blood glucose (β, -0.148; p = 0.008), age (β, -0.158; p = 0.005), and the presence of NAFLD (β, -0.132; p = 0.016) inversely correlated with FMD, whereas female gender predicted a better FMD (β, 0.125; p = 0.022). FMD and Framingham Risk Score (FRS) were inversely correlated (Rs, -0.183; p <0.001). After dividing patients into low (FRS <10; FMD, 5.5% [3.1% to 8.9%]), intermediate (FRS 10 to 20; FMD, 4.9% [2.7% to 7.5%]), and high (FRS >20; FMD, 3.3% [1.7% to 4.5%]) risk, FMD significantly decreased across risk classes of FRS (p = 0.003). At multivariate regression analysis, both FRS (β, -0.129; p = 0.016) and NAFLD (β, -0.218; p <0.001) were variables independently associated with FMD. In conclusion, the presence of NAFLD and FRS inversely correlated with FMD.

  13. Flow Mediated Dilatation as a Biomarker in Vascular Surgery Research

    PubMed Central

    Handa, Ashok

    2017-01-01

    Endothelial dysfunction is one of the hallmarks of atherogenesis, and correlates with many cardiovascular risk factors. One of the features of endothelial dysfunction is the loss of nitric oxide (NO) bioavailability, resulting in derangements in the vasodilatory response of the vessel wall. Flow mediated dilatation (FMD) of the brachial artery is an accepted method for non-invasive assessment of systemic endothelial function. FMD is examined extensively in the context of cardiovascular research, and has been utilised as a routine assessment in large cohorts such as the Framingham Heart Study, Young Finns Study, and Gutenberg Heart Study. However, FMD is less known in the context of vascular surgery research, despite the similarities between the underpinning disease mechanisms. This review will provide a summary of FMD in terms of its history of development and the conduct of the test in research settings. It will further highlight the key literature of FMD as a biomarker for vascular surgeons, particularly in the context of abdominal aortic aneurysms and lower limb peripheral arterial disease. PMID:28674324

  14. Flow Mediated Dilatation and Progression of Abdominal Aortic Aneurysms

    PubMed Central

    Lee, Regent; Bellamkonda, Kirthi; Jones, Amy; Killough, Nicholas; Woodgate, Felicity; Williams, Matthew; Cassimjee, Ismail; Handa, Ashok

    2017-01-01

    Objective/Background Biomarker(s) for prediction of the future progression rate of abdominal aortic aneurysms (AAA) may be useful to stratify the management of individual patients. AAAs are associated with features of systemic inflammation and endothelial dysfunction. Flow mediated dilatation (FMD) of the brachial artery is a recognised non-invasive measurement for endothelial function. We hypothesised that FMD is a potential biomarker of AAA progression and reflects the temporal changes of endothelial function during AAA progression. Methods In a prospectively recruited cohort of patients with AAAs (Oxford Abdominal Aortic Aneurysm Study), AAA size was recorded by antero-posterior diameter (APD) (outer to outer) on ultrasound. Annual AAA progression was calculated by (ΔAPD/APD at baseline)/(number of days lapsed/365 days). FMD was assessed at the same time as AAA size measurement. Analyses of data were performed in the overall cohort, and further in subgroups of AAA by size (small: 30–39 mm; moderate: 40–55 mm; large: > 55 mm). Results FMD is inversely correlated with the diameter of AAAs in all patients (n = 162, Spearman’s r = −.28, p < .001). FMD is inversely correlated with AAA diameter progression in the future 12 months (Spearman’s r = −.35, p = .001), particularly in the moderate size group. Furthermore, FMD deteriorates during the course of AAA surveillance (from a median of 2.0% at baseline to 1.2% at follow-up; p = .004), while surgical repair of AAAs (n = 50 [open repair n = 22, endovascular repair n = 28)] leads to an improvement in FMD (from 1.1% pre-operatively to 3.8% post-operatively; p < .001), irrespective of the type of surgery. Conclusion FMD is inversely correlated with future AAA progression in humans. FMD deteriorates during the natural history of AAA, and is improved by surgery. The utility of FMD as a potential biomarker in the context of AAA warrants further investigation. PMID:28416190

  15. Crucial role of NO and endothelium-derived hyperpolarizing factor in human sustained conduit artery flow-mediated dilatation.

    PubMed

    Bellien, Jeremy; Iacob, Michele; Gutierrez, Laurence; Isabelle, Marc; Lahary, Agnes; Thuillez, Christian; Joannides, Robinson

    2006-12-01

    Whether NO is involved or not in sustained conduit artery flow-mediated dilatation in humans remains unclear. Moreover, the role of endothelium-derived hyperpolarizing factor (EDHF), synthesized by cytochrome epoxygenases and acting through calcium-activated potassium channels, and its relationship with NO during flow-mediated dilatation have never been investigated previously. In 12 healthy subjects we measured radial artery diameter (echotracking) and blood flow (Doppler) during flow-mediated dilatation induced by gradual distal hand skin heating (34 to 44 degrees C), during the local infusion of saline and inhibitors of NO synthase (N(G)-monomethyl-l-arginine [l-NMMA]: 8 to 20 micromol/min per liter), calcium-activated potassium channels (tetraethylammonium chloride: 9 micromol/min per liter), and cytochrome epoxygenases (fluconazole: 0.4 to 1.6 micromol/min per liter), alone and in combination. Mean wall shear stress, the flow-mediated dilatation stimulus, was calculated at each level of flow, and the diameter-wall shear stress relationship was constructed. During heating, compared with saline, the diameter-shear stress relationship was shifted downward by l-NMMA, tetraethylammonium, fluconazole, and, in a more pronounced manner, by the combinations of l-NMMA with tetraethylammonium or with fluconazole. Therefore, maximal radial artery flow-mediated dilatation, compared with saline (0.62+/-0.03 mm), was decreased under our experimental conditions by l-NMMA (-39+/-4%), tetraethylammonium chloride (-14+/-4%), fluconazole (-18+/-6%), and to a greater extent, by the combinations of l-NMMA with tetraethylammonium (-64+/-4%) or with fluconazole (-71+/-3%). This study demonstrates that NO and a cytochrome-related EDHF are involved in peripheral conduit artery flow-mediated dilatation in humans during sustained flow conditions. Moreover, the synergistic effects of the inhibitors strongly suggest a functional interaction between NO and EDHF pathways.

  16. A meta-analysis of randomized controlled trials of telmisartan for flow-mediated dilatation.

    PubMed

    Takagi, Hisato; Umemoto, Takuya

    2014-09-01

    There have been a number of small-sized underpowered randomized controlled trials to assess effects of telmisartan on flow-mediated dilatation (FMD). To determine whether telmisartan increases FMD, we performed a meta-analysis of these trials. MEDLINE, EMBASE and the Cochrane Central Register of Controlled Trials were searched through December 2013. Eligible studies were prospective randomized controlled trials of telmisartan reporting FMD as an outcome. Search terms included: telmisartan; endothelial function/dysfunction; flow-mediated dilation/dilatation/vasodilation/vasodilatation; and randomized, randomly or randomization. Included studies were reviewed to determine the number of patients randomized, mean duration of treatment and percent changes of FMD. Of 25 potentially relevant articles screened initially, seven reports of randomized trials enrolling a total of 398 patients were identified and included. A pooled analysis of the seven trials demonstrated a statistically significant increase in FMD by 48.7%, with telmisartan relative to control in the random-effects model (mean difference, 48.72%; 95% confidence interval, 15.37-82.08%; P for effect=0.004; P for heterogeneity <0.00001). Exclusion of any single trial from the analysis did not substantively alter the overall result of our analysis. There was no evidence of significant publication bias. In conclusion, the present meta-analysis of seven randomized controlled trials enrolling a total of 398 patients confirmed the evidence of a significant increase in FMD with telmisartan, which suggests that telmisartan may improve endothelial dysfunction.

  17. Genetic contribution to brachial artery flow-mediated dilation: The Northern Manhattan Family Study

    PubMed Central

    Suzuki, Keiko; Juo, Suh-Hang Hank; Rundek, Tanja; Boden-Albala, Bernadette; Disla, Norbelina; Liu, Rui; Park, Naeun; Di Tullio, Marco R.; Sacco, Ralph L.; Homma, Shunichi

    2007-01-01

    Background Brachial artery flow-mediated dilation (FMD) is a non-invasive measure of endothelial function. Endothelial dysfunction has been associated with traditional vascular risk factors and increased risk of cardiovascular disease. The importance of genetic contribution to FMD and baseline brachial artery diameter has not been shown in Hispanic populations. The purpose of this study was to estimate the heritability of FMD. Methods Flow mediated dilation and brachial artery diameter were measured in a subset of Caribbean Hispanic families from the ongoing Northern Manhattan Family Study (NOMAFS), which studies the contribution of genetics to stroke and cardiovascular risk factors. The age- and sex-adjusted heritability of FMD was estimated using variance component methods. Results The current data include 620 subjects (97 probands and 523 relatives) from 97 families. The age and sex-adjusted heritability of brachial artery diameter was 0.57 (p < 0.01). The age- and sex-adjusted heritability of FMD was 0.20 (p = 0.01). After additional adjustment for systolic and diastolic blood pressure, body mass index, smoking, lipid, diabetes mellitus, medication, and baseline brachial artery diameter, the heritability of FMD was 0.17 (p = 0.01). Conclusions We found modest heritability of FMD. FMD might be a reasonable phenotype for further investigation of genetic contribution to atherosclerosis. PMID:17462653

  18. The clinical relevance of the percentage flow-mediated dilation index.

    PubMed

    Atkinson, Greg; Batterham, Alan M

    2015-02-01

    In 2010, the American College of Cardiology Foundation and American Heart Association could not recommend brachial artery percentage flow-mediated dilation (FMD%) for risk assessment of coronary artery disease (CAD) in asymptomatic adults. We aimed to scrutinise past and recently published findings regarding FMD% in this same context of clinical utility and conclude that (1) the question of whether brachial FMD% is a suitable substitute for coronary vasodilation is addressed by method agreement statistics rather than the correlation coefficients that have been reported in past studies. Also, the much-repeated view that brachial FMD% and coronary vasodilation are "closely related" is not entirely justified, even before the influence of baseline lumen diameters on this relationship is accounted for; (2) along with the specialist training and the considerable time (≥1 h) that is required for the FMD% protocol, the error in individual measurements and population reference ranges is too large for clinical decisions to be robust on individual patients; (3) many interventions that are proposed to change FMD% also change baseline artery diameter, which can bias estimates of any intervention effects on the flow-mediated response per se, and (4) the FMD% index generates spurious correlations between shear rate, artery diameter and endothelial function, which may help to explain the apparent paradoxes of FMD% being higher in obese people and lower in athletes. In conclusion, the clinical relevance of brachial artery flow-mediated dilation is unclear at present. The dependence of the chosen index, FMD%, on initial artery size has contributed to this lack of clarity.

  19. Potentially spurious correlations between arterial size, flow-mediated dilation, and shear rate.

    PubMed

    Veglia, Fabrizio; Amato, Mauro; Giovannardi, Marta; Ravani, Alessio; Tedesco, Calogero C; Frigerio, Beatrice; Sansaro, Daniela; Tremoli, Elena; Baldassarre, Damiano

    2014-12-01

    The use of indices formed from the ratio of 2 variables often generates spurious correlations with other variables that are mathematically coupled. In this context, we examined the correlations between percent flow-mediated dilation, baseline diameter, and shear rate. In a sample of 315 participants, with and without substantial vascular risk factors, the observed correlation coefficients between the variables were of a similar magnitude to those reported in the literature. We then applied a Monte Carlo procedure based on random permutations to remove any physical or physiological explanation for these correlations. We found that the median residual correlation coefficients were comparable with those observed in our original sample. When the confounding influence of artery size was adjusted for, the mean difference in percent flow-mediated dilation between high-risk and low-risk samples was halved. These findings indicate that the widely reported correlations between flow-mediated dilation, basal artery diameter, and shear rate have a substantial spurious component. This is because percent flow-mediated dilation and shear rate are mathematically coupled to artery size.

  20. Characterizing Methods of Measuring Flow-Mediated Dilation in the Brachial Artery

    NASA Technical Reports Server (NTRS)

    Callender, Ariane R.

    2010-01-01

    Regulation of vascular tone is one of the many important functions of the vascular endothelium. Endothelial dysfunction is a critical early event in the pathogenesis of atherosclerosis and occurs in the absence of angiographic disease. Flow-Mediated Dilation (FMD) is a noninvasive technique commonly used to evaluate endothelium-dependent vasodilation in humans and gauge the health of the cardiovascular system. Reductions in brachial artery FMD have been strongly correlated with disease progression and are predictive of future cardiac events. The flow stimulus for brachial artery FMD occurs as a result of the increased shear stress following deflation of an occlusion cuff around the upper arm. Using 2-dimensional ultrasound, changes in arterial diameter up to 5-minutes following cuff deflation are calculated from baseline image measurements. Along with pulsed Doppler measures of flow velocity through the artery, flow-mediated, endothelium-dependent vasodilation can be assessed. There is debate among investigators, however, about the proper positioning of the occlusion cuff during FMD testing. It is thought that placement of the cuff around the upper arm may not accurately reflect the impact of nitric oxide, a critically important molecule released as a result of the increased shear stress created by the FMD technique. Data suggest that the production of other endogenous metabolites may also contribute to FMD-related changes when positioning the cuff around the upper arm. To overcome the potential influence of such molecules, researchers now suggest that the occlusion cuff be placed below the elbow allowing a more precise estimate of nitric oxide mediated dilation. The purpose of this study is to compare the differences in FMD between the two methodologies of occlusion cuff placement. In addition, this study will determine the method that is easier for ultrasound technicians to perform and will produce a low coefficient of variance between technicians. Ultimately

  1. Critical Role for Telomerase in the Mechanism of Flow-Mediated Dilation in the Human Microcirculation

    PubMed Central

    Freed, Julie K.; Durand, Matthew J.; Riedel, Michael; Ait-Aissa, Karima; Green, Paula; Hockenberry, Joseph C.; Morgan, R. Garret; Donato, Anthony J.; Peleg, Refael; Gasparri, Mario; Rokkas, Chris K.; Santos, Janine H.; Priel, Esther; Gutterman, David D.

    2016-01-01

    Rationale: Telomerase is a nuclear regulator of telomere elongation with recent reports suggesting a role in regulation of mitochondrial reactive oxygen species. Flow-mediated dilation in patients with cardiovascular disease is dependent on the formation of reactive oxygen species. Objective: We examined the hypothesis that telomerase activity modulates microvascular flow-mediated dilation, and loss of telomerase activity contributes to the change of mediator from nitric oxide to mitochondrial hydrogen peroxide in patients with coronary artery disease (CAD). Methods and Results: Human coronary and adipose arterioles were isolated for videomicroscopy. Flow-mediated dilation was measured in vessels pretreated with the telomerase inhibitor BIBR-1532 or vehicle. Statistical differences between groups were determined using a 2-way analysis of variance repeated measure (n≥4; P<0.05). L-NAME (Nω-nitro-L-arginine methyl ester; nitric oxide synthase inhibitor) abolished flow-mediated dilation in arterioles from subjects without CAD, whereas polyethylene glycol-catalase (PEG-catalase; hydrogen peroxide scavenger) had no effect. After exposure to BIBR-1532, arterioles from non-CAD subjects maintained the magnitude of dilation but changed the mediator from nitric oxide to mitochondrial hydrogen peroxide (% max diameter at 100 cm H2O: vehicle 74.6±4.1, L-NAME 37.0±2.0*, PEG-catalase 82.1±2.8; BIBR-1532 69.9±4.0, L-NAME 84.7±2.2, PEG-catalase 36.5±6.9*). Conversely, treatment of microvessels from CAD patients with the telomerase activator AGS 499 converted the PEG-catalase-inhibitable dilation to one mediated by nitric oxide (% max diameter at 100 cm H2O: adipose, AGS 499 78.5±3.9; L-NAME 10.9±17.5*; PEG-catalase 79.2±4.9). Endothelial-independent dilation was not altered with either treatment. Conclusions: We have identified a novel role for telomerase in re-establishing a physiological mechanism of vasodilation in arterioles from subjects with CAD. These findings

  2. Critical Role for Telomerase in the Mechanism of Flow-Mediated Dilation in the Human Microcirculation.

    PubMed

    Beyer, Andreas M; Freed, Julie K; Durand, Matthew J; Riedel, Michael; Ait-Aissa, Karima; Green, Paula; Hockenberry, Joseph C; Morgan, R Garret; Donato, Anthony J; Peleg, Refael; Gasparri, Mario; Rokkas, Chris K; Santos, Janine H; Priel, Esther; Gutterman, David D

    2016-03-04

    Telomerase is a nuclear regulator of telomere elongation with recent reports suggesting a role in regulation of mitochondrial reactive oxygen species. Flow-mediated dilation in patients with cardiovascular disease is dependent on the formation of reactive oxygen species. We examined the hypothesis that telomerase activity modulates microvascular flow-mediated dilation, and loss of telomerase activity contributes to the change of mediator from nitric oxide to mitochondrial hydrogen peroxide in patients with coronary artery disease (CAD). Human coronary and adipose arterioles were isolated for videomicroscopy. Flow-mediated dilation was measured in vessels pretreated with the telomerase inhibitor BIBR-1532 or vehicle. Statistical differences between groups were determined using a 2-way analysis of variance repeated measure (n≥4; P<0.05). L-NAME (N(ω)-nitro-L-arginine methyl ester; nitric oxide synthase inhibitor) abolished flow-mediated dilation in arterioles from subjects without CAD, whereas polyethylene glycol-catalase (PEG-catalase; hydrogen peroxide scavenger) had no effect. After exposure to BIBR-1532, arterioles from non-CAD subjects maintained the magnitude of dilation but changed the mediator from nitric oxide to mitochondrial hydrogen peroxide (% max diameter at 100 cm H2O: vehicle 74.6±4.1, L-NAME 37.0±2.0*, PEG-catalase 82.1±2.8; BIBR-1532 69.9±4.0, L-NAME 84.7±2.2, PEG-catalase 36.5±6.9*). Conversely, treatment of microvessels from CAD patients with the telomerase activator AGS 499 converted the PEG-catalase-inhibitable dilation to one mediated by nitric oxide (% max diameter at 100 cm H2O: adipose, AGS 499 78.5±3.9; L-NAME 10.9±17.5*; PEG-catalase 79.2±4.9). Endothelial-independent dilation was not altered with either treatment. We have identified a novel role for telomerase in re-establishing a physiological mechanism of vasodilation in arterioles from subjects with CAD. These findings suggest a new target for reducing the oxidative milieu

  3. Detailed exploration of the endothelium: parameterization of flow-mediated dilation through principal component analysis.

    PubMed

    Laclaustra, Martin; Frangi, Alejandro F; Garcia, Daniel; Boisrobert, Loïc; Frangi, Andres G; Pascual, Isaac

    2007-03-01

    Endothelial dysfunction is associated with cardiovascular diseases and their risk factors (CVRF), and flow-mediated dilation (FMD) is increasingly used to explore it. In this test, artery diameter changes after post-ischaemic hyperaemia are classically quantified using maximum peak vasodilation (FMDc). To obtain more detailed descriptors of FMD we applied principal component analysis (PCA) to diameter-time curves (absolute), vasodilation-time curves (relative) and blood-velocity-time curves. Furthermore, combined PCA of vessel size and blood-velocity curves allowed exploring links between flow and dilation. Vessel diameter data for PCA (post-ischaemic: 140 s) were acquired from brachial ultrasound image sequences of 173 healthy male subjects using a computerized technique previously reported by our team based on image registration (Frangi et al 2003 IEEE Trans. Med. Imaging 22 1458). PCA provides a set of axes (called eigenmodes) that captures the underlying variation present in a database of waveforms so that the first few eigenmodes retain most of the variation. These eigenmodes can be used to synthesize each waveform analysed by means of only a few parameters, as well as potentially any signal of the same type derived from tests of new patients. The eigenmodes obtained seemed related to visual features of the waveform of the FMD process. Subsequently, we used eigenmodes to parameterize our data. Most of the main parameters (13 out of 15) correlated with FMDc. Furthermore, not all parameters correlated with the same CVRF tested, that is, serum lipids (i.e., high LDL-c associated with slow vessel return to a baseline, while low HDL-c associated with a lower vasodilation in response to similar velocity stimulus), thus suggesting that this parameterization allows a more detailed and factored description of the process than FMDc.

  4. Putative endothelial progenitor cells are associated with flow-mediated dilation in refractory hypertensives.

    PubMed

    Oliveras, Anna; de la Sierra, Alejandro; Martínez-Estrada, Ofelia M; Larrousse, María; Vázquez, Susana; Soler, Maria José; Zuasti, Mercedes; Vila, Joan S; Reina, Manuel; Roca-Cusachs, Alex; Lloveras, Josep

    2008-01-01

    Hypertension has been related to endothelial dysfunction. Patients with refractory hypertension (RH) have a reduced number of endothelial progenitor cells (EPCs). To evaluate if blood EPC levels relate to endothelium-dependent vasodilation (ED-VD) in RH. We analyzed 29 RH confirmed by 24-h ambulatory blood pressure monitoring and assessed complete clinical and laboratory evaluation. EPCs were isolated from peripheral mononuclear cells (MNC) by flow cytometry. ED-VD was determined measuring flow-mediated dilation (FMD) by venous occlusion plethysmography. Results. Circulating EPCs/10(5) MNC (median [Q1-Q3]): 23.0 [4.5-53.8]. FMD (median [Q1-Q3]): 211.7 [79.5-365.8]%. Significant correlations with log-FMD: EPCs (r = 0.469; p = 0.018) and homocysteine (r = -0.414; p = 0.045). There was no collinearity between EPCs and homocysteine. FMD did not correlate with age, gender, office BP, 24-h systolic blood pressure or 24-h diastolic blood pressure, laboratory parameters, C-reactive-protein, left ventricular-mass index, dyslipidaemia, smoking habit and statin or angiotensin system blockers treatment. Multiple linear regression analysis showed that after age-adjustment, EPC (p = 0.027) and homocysteine (p = 0.004) were the only variables that predicted FMD (R = 0.740). After dividing patients according to EPC number, patients in the lower tertile showed a significantly reduced FMD compared with those in the group of the two upper tertiles of EPC: log-FMD (mean+/-SD): 4.7+/-0.9 vs 5.6+/-0.8, respectively (p = 0.031). ED-VD independently correlates with circulating EPCs in RH. Homocysteine is also an independent predictor of lower FMD in such patients.

  5. The Association between Flow-Mediated Dilation and Physical Function in Older Men

    PubMed Central

    WELSCH, MICHAEL A.; DOBROSIELSKI, DEVON A.; ARCE-ESQUIVEL, ARTURO A.; WOOD, ROBERT H.; RAVUSSIN, ERIC; ROWLEY, CHRISTINA; JAZWINSKI, S. MICHAL

    2010-01-01

    The probability that an individual is able to live independently decreases sharply below the threshold score of 57 units on the physical functional performance (PFP-10) test. Purpose To examine the relation between brachial artery flow-mediated dilation (BAFMD) on individual and total scores on the PFP-10. We hypothesized that lower scores on the PFP-10 test would be associated with lower BAFMD. Methods Sixty-four men (age, 84 ± 11 yr) from the Louisiana Healthy Aging Study were studied. Participants were classified by their performance on the PFP-10 test (Class I, score <26; Class II, score between 26 and 57; and Class III, score > 57). BAFMD was assessed after 5 min of forearm occlusion, using high-resolution ultrasonography. Results The average total score on the PFP-10 test and BAFMD were 42.9 ± 22 U and 2.76 ± 2.13%, respectively. The BAFMD was associated with total PFP-10 score (r = 0.45, P = 0.0001) and age (r = −0.36, P = 0.003). BAFMD was significantly different (P = 0.001) between the PFP-10 classes (Class I, 1.44% [95% CI, 0.49–2.39]; Class II, 2.67% [95% CI, 1.95–3.38]; and Class III, 4.01% [95% CI, 3.16–4.85]). Conclusions This study reports significant relationships between BAFMD and individual and combined measures of physical function in elderly men. More specifically, when individuals were categorized based on their PFP-10 total score, those in the highest functional class, exhibited the highest BAFMD, compared to those in the middle class, who had greater vasoreactivity than those in the lowest functional class. PMID:18580402

  6. Aortic stiffness and flow-mediated dilatation in normotensive offspring of parents with hypertension.

    PubMed

    Evrengul, Harun; Tanriverdi, Halil; Kilic, Ismail D; Dursunoglu, Dursun; Ozcan, Emin E; Kaftan, Asuman; Kilic, Mustafa

    2012-08-01

    Although hypertension has been shown to be one of the most important risk factors for atherosclerosis, data about the presence of subclinical atherosclerosis in normotensive offspring with parental history of hypertension are scarce. Accordingly, the current study was designated to evaluate flow-mediated dilatation and aortic stiffness, which are early signs of atherosclerosis in young subjects with parental history of hypertension. A total of 140 [corrected] healthy, non-obese subjects in the age group of 18-22 years were included in this study and divided into two groups. The first group included 70 offspring of hypertensive parents and the second group included 70 offspring of normotensive parents as controls. In all subjects, endothelium-dependent and endothelium-independent vasodilatation of the brachial artery and aortic elastic parameters were investigated using high-resolution Doppler echocardiography. Offspring of hypertensive parents demonstrated higher values of aortic stiffness (7.1 plus or minus 1.88 and 6.42 plus or minus 1.56, respectively) but lower distensibility (9.47 plus or minus 1.33 and 11.8 plus or minus 3.36 square centimetres per dyne per 106) and flow-mediated dilatation (4.57 plus or minus 1.3 versus 6.34 plus or minus 0.83 percent, p equals 0.0001, respectively) than offspring of hypertensive parents. We observed blunted endothelium-dependent dilatation and aortic stiffness in offspring of hypertensive parents compared with offspring of normotensive [corrected] parents. This is evident in the absence of overt hypertension and other diseases, suggesting that parental history of hypertension is a risk for subclinical atherosclerosis and it may contribute to the progression to hypertension and overt atherosclerosis in later life.

  7. Accurate evaluation of viscoelasticity of radial artery wall during flow-mediated dilation in ultrasound measurement

    NASA Astrophysics Data System (ADS)

    Sakai, Yasumasa; Taki, Hirofumi; Kanai, Hiroshi

    2016-07-01

    In our previous study, the viscoelasticity of the radial artery wall was estimated to diagnose endothelial dysfunction using a high-frequency (22 MHz) ultrasound device. In the present study, we employed a commercial ultrasound device (7.5 MHz) and estimated the viscoelasticity using arterial pressure and diameter, both of which were measured at the same position. In a phantom experiment, the proposed method successfully estimated the elasticity and viscosity of the phantom with errors of 1.8 and 30.3%, respectively. In an in vivo measurement, the transient change in the viscoelasticity was measured for three healthy subjects during flow-mediated dilation (FMD). The proposed method revealed the softening of the arterial wall originating from the FMD reaction within 100 s after avascularization. These results indicate the high performance of the proposed method in evaluating vascular endothelial function just after avascularization, where the function is difficult to be estimated by a conventional FMD measurement.

  8. SpLiNeS: automatic analysis of ecographic movies of flow-mediated dilation

    NASA Astrophysics Data System (ADS)

    Bartoli, Guido; Menegaz, Gloria; Dragoni, Saverio; Gori, Tommaso

    2007-03-01

    In this paper, we propose a fully automatic system for analyzing ecographic movies of flow-mediated dilation. Our approach uses a spline-based active contour (deformable template) to follow artery boundaries during the FMD procedure. A number of preprocessing steps (grayscale conversion, contrast enhancing, sharpening) are used to improve the visual quality of frames coming from the echographic acquisition. Our system can be used in real-time environments due to the high speed of edge recognition which iteratively minimizes fitting errors on endothelium boundaries. We also implemented a fully functional GUI which permits to interactively follow the whole recognition process as well as to reshape the results. The system accuracy and reproducibility has been validated with extensive in vivo experiments.

  9. The Effects of Exercise Training on Brachial Artery Flow-Mediated Dilation: A Meta-analysis.

    PubMed

    Early, Kate S; Stewart, Abigail; Johannsen, Neil; Lavie, Carl J; Thomas, Jerry R; Welsch, Michael

    2017-03-01

    Flow-mediated dilation, a barometer of cardiovascular (CV) health, is reported to increase with exercise training (ET); however, the potential moderating factors of ET are not clear to date. The purpose of this study was to determine the effect of ET assessed by brachial artery flow-mediated dilation (BAFMD). Authors searched PubMed between January 1999 and December 2013, bibliographies, and reviews to identify studies examining ET and BAFMD. Two independent reviewers extracted quality, descriptive, exercise, and outcome data of eligible studies. Data were presented as weighted effect sizes (ESs) and 95% confidence limits. Analysis included 66 studies reporting BAFMD data (1865 ET and 635 control subjects). Overall, ET had significant improvements in BAFMD compared with controls (P < .0001). Exercise training at higher ET intensities resulted in a greater increase in BAFMD (9.29; 95% CI, 5.09-13.47) than lower ET intensities (3.63; 95% CI, -0.56 to 7.83) or control (-0.42; 95% CI, -2.06 to 1.21). Subjects whose ET duration was ≥150 min/wk (11.33; 95% CI, 7.15-15.51) had a significant improvement in BAFMD compared with those with <150 min/wk (4.79; 95% CI, 3.08-6.51) or control (-0.30; 95% CI, -1.99 to 1.39). Age (P = .11) and baseline artery diameter (P = .31) did not modify the BAFMD response to ET. Exercise training contributes to a significant increase in BAFMD. These results provide indirect evidence that ET alters a well-known factor associated with the primary and secondary prevention of CV diseases. Exercise training interventions, including greater intensity and duration, may optimize the increase in BAFMD.

  10. Systemic endothelial function measured by flow-mediated dilation is impaired in patients with urolithiasis.

    PubMed

    Yencilek, Esin; Sarı, Hakan; Yencilek, Faruk; Yeşil, Ezgi; Aydın, Hasan

    2016-11-23

    Some in vitro and animal studies have shown endothelial dysfunction in hyperoxaluria models indicating its role in pathogenesis of urolithiasis and relation to CVD. The aim of this study was to investigate endothelial function in patients with urolithiasis in relation to urinary stone risk factors and metabolic parameters. A total of 120 subjects without any known CVD (60 with urolithiasis and 60 healthy subjects) were included into study. Fasting blood and 24-h urine samples were collected to study metabolic parameters (glucose and lipids) and urine stone risk factors (oxalate, citrate, uric acid, and calcium, pH). Endothelial function was assessed as flow-mediated dilation (FMD) at the brachial artery. Age, sex, and body mass index were similar in patients and controls. Of urine stone risk factors, oxalate and citrate were higher in patients than controls. Fasting blood glucose, total LDL cholesterol, and triglyceride were higher, and HDL cholesterol was lower in patients than controls. Although within normal limits systolic blood pressure was higher in patient group, patients with urolithiasis had a lower %FMD than controls. Percent FMD was negatively correlated with urinary oxalate/creatinine ratio (p = 0.019, r = -0.315), calcium/creatinine ratio (p = 0.0001, r = -0.505) age (p < 0.001, r = -0.694), BMI (p < 0.001, r = -0.838), total cholesterol (p < 0.001, r = -0.559), and triglyceride (p < 0.001, r = -0.529). Urine oxalate/creatinine ratio was positively correlated with age (p = 0.01, r = 0.327) and calcium/creatinine ratio with BMI (p = 0.001, r = 0.410). This is the first study demonstrating endothelial dysfunction in human subjects with urolithiasis. This indicates a possible predictive role of urolithiasis in future development of cardiovascular diseases.

  11. Consumption of energy beverage is associated with attenuation of arterial endothelial flow-mediated dilatation

    PubMed Central

    Higgins, John P; Yang, Benjamin; Herrin, Nikki E; Yarlagadda, Santi; Le, George T; Ortiz, Brandon L; Ali, Asif; Infanger, Stephen C

    2017-01-01

    AIM To investigate whether consumption of an energy drink will acutely impair endothelial function in young healthy adults. METHODS Energy drinks are being consumed more and more worldwide, and have been associated with some deaths in adolescents and young adults, especially when consumed while exercising. After fasting and not smoking for at least 8 h prior, eleven medical students (9 males) received an electrocardiogram, blood pressure and pulse check, and underwent baseline testing (BL) of endothelial function using the technique of endothelium-dependent flow mediated dilatation (FMD) with high-resolution ultrasound (according to recommended guidelines of the University of Wisconsin Atherosclerosis Imaging Research Program Core Laboratory). The subjects then drank an energy beverage (EB), a 24-oz can of Monster Energy, and the above was repeated at 90 min after consumption. The relative FMD (%) was calculated as the ratio between the average post-cuff release and the baseline diameter. Each image was checked for quality control, and each artery diameter was measured from the media to media points by two experts, 3 measurements at the QRS complex, repeated on 3 separate beats, and then all were averaged. RESULTS Subjects characteristics averages (given with standard deviations) include: Age 24.5 ± 1.5 years, sex 9 male and 2 female, weight 71.0 ± 9.1 kg, height 176.4 ± 6.0 cm, BMI 22.8 ± 2.7 kg/m2. The hemodynamics were as follows, BL vs EB group respectively (mean ± SD): Heart rate 65.2 ± 11.3 vs 68.2 ± 11.8 beats per minute, systolic blood pressure 114.0 ± 10.4 mmHg vs 114.1 ± 10.4 mmHg, diastolic blood pressure 68.8 ± 9.3 mmHg vs 70.6 ± 7.1 mmHg; all were not significantly different. However after drinking the EB, a significantly attenuated peak FMD response was measured (mean ± SD): BL group 5.9% ± 4.6% vs EB group 1.9% ± 2.1%; P = 0.03). Given the increased consumption of energy beverages associated with exercise in young adults, more research

  12. Consumption of energy beverage is associated with attenuation of arterial endothelial flow-mediated dilatation.

    PubMed

    Higgins, John P; Yang, Benjamin; Herrin, Nikki E; Yarlagadda, Santi; Le, George T; Ortiz, Brandon L; Ali, Asif; Infanger, Stephen C

    2017-02-26

    To investigate whether consumption of an energy drink will acutely impair endothelial function in young healthy adults. Energy drinks are being consumed more and more worldwide, and have been associated with some deaths in adolescents and young adults, especially when consumed while exercising. After fasting and not smoking for at least 8 h prior, eleven medical students (9 males) received an electrocardiogram, blood pressure and pulse check, and underwent baseline testing (BL) of endothelial function using the technique of endothelium-dependent flow mediated dilatation (FMD) with high-resolution ultrasound (according to recommended guidelines of the University of Wisconsin Atherosclerosis Imaging Research Program Core Laboratory). The subjects then drank an energy beverage (EB), a 24-oz can of Monster Energy, and the above was repeated at 90 min after consumption. The relative FMD (%) was calculated as the ratio between the average post-cuff release and the baseline diameter. Each image was checked for quality control, and each artery diameter was measured from the media to media points by two experts, 3 measurements at the QRS complex, repeated on 3 separate beats, and then all were averaged. Subjects characteristics averages (given with standard deviations) include: Age 24.5 ± 1.5 years, sex 9 male and 2 female, weight 71.0 ± 9.1 kg, height 176.4 ± 6.0 cm, BMI 22.8 ± 2.7 kg/m(2). The hemodynamics were as follows, BL vs EB group respectively (mean ± SD): Heart rate 65.2 ± 11.3 vs 68.2 ± 11.8 beats per minute, systolic blood pressure 114.0 ± 10.4 mmHg vs 114.1 ± 10.4 mmHg, diastolic blood pressure 68.8 ± 9.3 mmHg vs 70.6 ± 7.1 mmHg; all were not significantly different. However after drinking the EB, a significantly attenuated peak FMD response was measured (mean ± SD): BL group 5.9% ± 4.6% vs EB group 1.9% ± 2.1%; P = 0.03). Given the increased consumption of energy beverages associated with exercise in young adults, more research is needed. Energy

  13. A control systems approach to quantify wall shear stress normalization by flow-mediated dilation in the brachial artery.

    PubMed

    van Bussel, Frank C G; van Bussel, Bas C T; Hoeks, Arnold P G; Op 't Roodt, Jos; Henry, Ronald M A; Ferreira, Isabel; Vanmolkot, Floris H M; Schalkwijk, Casper G; Stehouwer, Coen D A; Reesink, Koen D

    2015-01-01

    Flow-mediated dilation is aimed at normalization of local wall shear stress under varying blood flow conditions. Blood flow velocity and vessel diameter are continuous and opposing influences that modulate wall shear stress. We derived an index FMDv to quantify wall shear stress normalization performance by flow-mediated dilation in the brachial artery. In 22 fasting presumed healthy men, we first assessed intra- and inter-session reproducibilities of two indices pFMDv and mFMDv, which consider the relative peak and relative mean hyperemic change in flow velocity, respectively. Second, utilizing oral glucose loading, we evaluated the tracking performance of both FMDv indices, in comparison with existing indices [i.e., the relative peak diameter increase (%FMD), the peak to baseline diameter ratio (Dpeak/Dbase), and the relative peak diameter increase normalized to the full area under the curve of blood flow velocity with hyperemia (FMD/shearAUC) or with area integrated to peak hyperemia (FMD/shearAUC_peak)]. Inter-session and intra-session reproducibilities for pFMDv, mFMDv and %FMD were comparable (intra-class correlation coefficients within 0.521-0.677 range). Both pFMDv and mFMDv showed more clearly a reduction after glucose loading (reduction of ~45%, p≤0.001) than the other indices (% given are relative reductions): %FMD (~11%, p≥0.074); Dpeak/Dbase (~11%, p≥0.074); FMD/shearAUC_peak (~20%, p≥0.016) and FMD/shearAUC (~38%, p≤0.038). Further analysis indicated that wall shear stress normalization under normal (fasting) conditions is already far from ideal (FMDv < 1), which (therefore) does not materially change with glucose loading. Our approach might be useful in intervention studies to detect intrinsic changes in shear stress normalization performance in conduit arteries.

  14. Flow-mediated dilation benefits of mesoglycan in peripheral artery disease.

    PubMed

    Gossetti, B; Antignani, P L; Jabbour, J; Martinelli, O

    2015-08-01

    Mesoglycan, composed of natural glycosaminoglycans, is used for treatment in arterial and venous disease for its benefits on endothelial glicocalix. Little is known about mesoglycan impact on endothelial blood flow regulation. We sought to evaluate the effects of mesoglycan intermittently added to back-ground treatments on impairment of endothelial function in peripheral arterial disease (PAD) patients. We studied the effects of a 2+2 months oral treatment with 50 mg b.i.d. of mesoglycan, intervalled by 2 months without mesoglycan, in 540 PAD patients on four occasions (visit 1: baseline, visit 2: 2 months, visit 3: 4 months and visit 4: 6 months). At these time visits we assessed brachial artery endothelial-dependent flow-mediated dilation (FMD), together with femoral intima-medial thickness (IMT), and walking distance (WD). There were significant changes in FMD (1.88%, CI 95%: 1.13, 2.63; P<0.001), IMT (-0.05 mm, CI 95%: -0.07,-0.02; P<0.001) and WD (38,9%, CI 95% 33.2, 44.8; P<0.001). The positive effects and benefit were maintained during the two-months interval without mesoglycan treatment. Significant changes in FMD were observed in a number of patient groups, stratified for risk factors (aging, sex, smoke, diabetes, dyslipidemia, hypertension). Two months cycles with mesoglycan improved endothelial function in PAD patients, with a parallel reduction of atherosclerotic damage and amelioration of clinical condition.

  15. Prediction of early and late preeclampsia by flow-mediated dilation of the brachial artery*

    PubMed Central

    Brandão, Augusto Henriques Fulgêncio; Evangelista, Aline Aarão; Martins, Raphaela Menin Franco; Leite, Henrique Vítor; Cabral, Antônio Carlos Vieira

    2014-01-01

    Objective To assess the accuracy in the prediction of both early and late preeclampsia by flow-mediated dilation of the brachial artery (FMD), a biophysical marker for endothelial dysfunction. Materials and Methods A total of 91 patients, considered at high risk for development of preeclampsia were submitted to brachial artery FMD between 24 and 28 weeks of gestation. Results Nineteen out of the selected patients developed preeclampsia, 8 in its early form and 11 in the late form. With a cut-off value of 6.5%, the FMD sensitivity for early preeclampsia prediction was 75.0%, with specificity of 73.3%, positive predictive value (PPV) of 32.4% and negative predictive value (NPV) of 91.9%. For the prediction of late preeclampsia, sensitivity = 83.3%, specificity = 73.2%, PPV = 34.4% and NPV = 96.2% were observed. And for the prediction of all associated forms of preeclampsia, sensitivity = 84.2%, specificity = 73.6%, PPV = 45.7% and NPV = 94.6% were observed. Conclusion FMD of the brachial artery is a test with good accuracy in the prediction of both early and late preeclampsia, which may represent a positive impact on the follow-up of pregnant women at high risk for developing this syndrome. PMID:25741086

  16. Assessment of flow-mediated dilation in humans: a methodological and physiological guideline

    PubMed Central

    Black, Mark A.; Pyke, Kyra E.; Padilla, Jaume; Atkinson, Greg; Harris, Ryan A.; Parker, Beth; Widlansky, Michael E.; Tschakovsky, Michael E.; Green, Daniel J.

    2011-01-01

    Endothelial dysfunction is now considered an important early event in the development of atherosclerosis, which precedes gross morphological signs and clinical symptoms. The assessment of flow-mediated dilation (FMD) was introduced almost 20 years ago as a noninvasive approach to examine vasodilator function in vivo. FMD is widely believed to reflect endothelium-dependent and largely nitric oxide-mediated arterial function and has been used as a surrogate marker of vascular health. This noninvasive technique has been used to compare groups of subjects and to evaluate the impact of interventions within individuals. Despite its widespread adoption, there is considerable variability between studies with respect to the protocols applied, methods of analysis, and interpretation of results. Moreover, differences in methodological approaches have important impacts on the response magnitude, can result in spurious data interpretation, and limit the comparability of outcomes between studies. This review results from a collegial discussion between physiologists with the purpose of developing considered guidelines. The contributors represent several distinct research groups that have independently worked to advance the evidence base for improvement of the technical approaches to FMD measurement and analysis. The outcome is a series of recommendations on the basis of review and critical appraisal of recent physiological studies, pertaining to the most appropriate methods to assess FMD in humans. PMID:20952670

  17. Redundant Vasodilator Pathways Underlying Radial Artery Flow-Mediated Dilation Are Preserved in Healthy Aging

    PubMed Central

    Ballard, Kevin D.; Tschakovsky, Michael E.; Zaleski, Amanda L.; Polk, Donna M.; Thompson, Paul D.; Kiernan, Francis J.; Parker, Beth A.

    2014-01-01

    Background. Blocking nitric oxide (NO) and vasodilator prostanoids (PN) does not consistently reduce flow-mediated dilation (FMD) in young adults. The impact of aging on the contribution of NO and PG to FMD is unknown. Methods. FMD was measured in older adults (n = 10, 65 ± 3 y) after arterial infusion of saline, N(G)-monomethyl-L-arginine (L-NMMA), and ketorolac + L-NMMA. Data were compared to published data in young adults. Results. L-NMMA reduced FMD in older adults (8.9 ± 3.6 to 5.9 ± 3.7%) although this was not statistically significant (P = 0.08) and did not differ (P = 0.74) from the reduction observed in young adults (10.0 ± 3.8 to 7.6 ± 4.7%; P = 0.03). Blocking PN did not affect FMD in young or older adults. In older adults, L-NMMA reduced (n = 6; range = 36–123% decrease), augmented (n = 3; 10–122% increase), or did not change FMD (n = 1; 0.4% increase). After PN blockade, FMD responses were reduced (n = 2), augmented (n = 6), or unaffected (n = 1). Conclusions. NO or PN blockade did not consistently reduce FMD in healthy older adults, suggesting the existence of redundant vasodilator phenotypes as observed previously in young adults. PMID:24963406

  18. The impact of handgrip exercise duty cycle on brachial artery flow-mediated dilation.

    PubMed

    King, Trevor J; Slattery, David J; Pyke, Kyra E

    2013-07-01

    Endothelial function is essential for vasoprotection and regulation of vascular tone. Using handgrip exercise (HGEX) to increase blood flow-associated shear stress is an increasingly popular method for assessing brachial artery endothelial function via flow-mediated dilation (FMD). However, different exercise duty cycles [ratio of handgrip relaxation: contraction (seconds)] produce different patterns of brachial artery shear stress with distinct antegrade/retrograde magnitudes. To determine the impact of HGEX duty cycle on brachial artery %FMD, three distinct duty cycles were employed while maintaining a uniform mean shear stress. Brachial artery diameter and mean blood velocity were assessed via echo and Doppler ultrasound in 16 healthy male subjects. Shear stress was estimated as shear rate (SR = blood velocity/brachial artery diameter) and the target mean SR during HGEX was 75 s(-1). Subjects performed three 6-min HGEX trials on each of 2 days (like trials averaged). In each trial, subjects performed one of the three randomly ordered HGEX duty cycles (1:1, 3:1, 5:1). %FMD was calculated from baseline to the end of HGEX and (subset N = 10) during each minute of HGEX. Data are mean ± SD. As intended, mean SR was uniform across duty cycles (6 min HGEX average: 72.9 ± 4.9s(-1), 72.6 ± 3.6s(-1), 72.8 ± 3.5 s(-1), p = 0.835), despite differences in antegrade/retrograde SR (p < 0.001). End-exercise %FMD (4.0 ± 1.3 %, 4.1 ± 2.2 %, 4.2 ± 1.4 %, p = 0.860) and %FMD during exercise (p = 0.939) were not different between duty cycles. These data indicate that the endothelium responds to the mean shear stress and is not specifically sensitive to the contraction/relaxation or retrograde shear stress created by a range of HGEX protocols.

  19. Flow-Mediated Dilation and Neurocognition: Systematic Review and Future Directions.

    PubMed

    Naiberg, Melanie R; Newton, Dwight F; Goldstein, Benjamin I

    2016-01-01

    Previous literature indicates that flow-mediated dilation (FMD) is associated with impaired cognition among patients with stroke. The relationship between FMD and cognition in individuals without cerebrovascular disease has yet to be systematically reviewed. The literature was searched using MEDLINE. Exclusion criteria were as follows: focus on neurological disease (e.g., stroke), animal studies, no quantitative measure of endothelial function or cognition, newborn studies, articles with no original data, and articles that are irrelevant to the topic of interest. Neurocognitive tests were categorized in the following domains: executive function, memory (general, working, episodic/semantic, verbal, visual), global cognitive function, information processing speed, language, psychomotor speed, and visual-spatial ability. The search yielded 700 articles, of which 10 articles, consisting of 2791 participants, met the criteria for inclusion. Most studies conclude that impaired FMD is associated with poorer neuropsychological functioning, particularly in executive functioning (effect sizes: r = 0.07-0.58) and working memory tasks (effect sizes: r = 0.19-0.39). No association was found between other subdomains of memory and FMD. Visual spatial tasks, information processing speed, language tasks, and global cognition were not associated with FMD overall; however fewer studies examined these domains. Even in the absence of cerebrovascular disease, there are links between cognition, particularly executive tasks, and vascular function. Public health implications include the potential value of examining FMD as a predictor of cognitive decline, as well as the potential value of improving cognition through pharmacological and behavioral interventions that improve vascular function. Future studies incorporating neuroimaging measures of cerebral blood flow are warranted.

  20. Age and sex relationship with flow-mediated dilation in healthy children and adolescents

    PubMed Central

    Dengel, Donald R.; Stratton, Gareth; Kelly, Aaron S.; Steinberger, Julia; Zavala, Hanan; Marlatt, Kara; Perry, Daniel; Naylor, Louise H.; Green, Daniel J.

    2015-01-01

    Flow-mediated dilation (FMD) is a noninvasive technique used to measure conduit artery vascular function. Limited information is available on normative FMD values in healthy children and adolescents. The objective of this study was to assess relationships between age and sex with FMD across childhood and adolescence. Nine hundred and seventy-eight asymptomatic children (12 ± 3 yr, range 6–18 yr, 530 male) underwent ultrasonic brachial artery assessment before and after 5 min of forearm ischemia. Sex differences in FMD and baseline artery diameter were assessed using mixed linear models. Baseline artery diameter was smaller in females than males [2.96 mm (95% CI: 2.92–3.00) vs. 3.24 mm (3.19–3.28), P < 0.001] and increased with age across the cohort (P < 0.001). Diameter increased between ages 6 and 17 yr in males [from 2.81 mm (2.63, 3.00) to 3.91 mm (3.68, 4.14)] but plateaued at age 12 yr in females. Males had a lower FMD [7.62% (7.33–7.91) vs. 8.31% (7.95–8.66), P = 0.024], specifically at ages 17 and 18 yr. There was a significant effect of age on FMD (P = 0.023), with a reduction in FMD apparent postpuberty in males. In conclusion, the brachial artery increases structurally with age in both sexes; however, there are sex differences in the timing and rate of growth, in line with typical sex-specific adolescent growth patterns. Males have a lower FMD than females, and FMD appears to decline with age; however, these findings are driven by reductions in FMD as males near maturity. The use of age- and sex-specific FMD data may therefore not be pertinent in childhood and adolescence. PMID:26251515

  1. Impact of acute exercise on brachial artery flow-mediated dilatation in young healthy people

    PubMed Central

    2012-01-01

    Background Although chronic effects of exercise on endothelial function are established, the impact of acute exercise on flow-mediated dilatation (FMD) of brachial artery has not been elucidated yet. Methods Eighty-six young healthy volunteers were prospectively enrolled from January 2011 to December 2011. The subjects completed FMD tests at rest and immediately after treadmill exercise test. Primary outcome was the impact of acute exercise on FMD, measured by the difference of FMD before and after exercise. Secondary outcomes were the relationship of gender and exercise habit with FMD. Results Seventy-four subjects who met the eligibility criteria were included for analysis. Thirty-five (47.3%) were male, and the mean age was 22.7±2.7 years. FMD was reduced after exercise (8.98±4.69 to 7.51±4.03%; P=0.017) and the reduction was found in female group (10.36±5.26 to 7.62±3.71%; P=0.002) but not in male group. Post-exercise FMD was significantly impaired in subjects who did not exercise regularly (6.92±3.13% versus 8.95±5.33%; P=0.003). The decrease of FMD after exercise was greater in female group (−2.75±5.28% versus 0.27±3.24%; P=0.003) and was associated with exercise habit (β=2.532; P=0.027). Conclusions In healthy young subjects, FMD was reduced after a bout of acute exercise. The impact of acute exercise showed significant differences according to gender and exercise habit. FMD impairment after acute exercise was observed in females and subjects without regular exercise. PMID:23031621

  2. Age and sex relationship with flow-mediated dilation in healthy children and adolescents.

    PubMed

    Hopkins, Nicola D; Dengel, Donald R; Stratton, Gareth; Kelly, Aaron S; Steinberger, Julia; Zavala, Hanan; Marlatt, Kara; Perry, Daniel; Naylor, Louise H; Green, Daniel J

    2015-10-15

    Flow-mediated dilation (FMD) is a noninvasive technique used to measure conduit artery vascular function. Limited information is available on normative FMD values in healthy children and adolescents. The objective of this study was to assess relationships between age and sex with FMD across childhood and adolescence. Nine hundred and seventy-eight asymptomatic children (12 ± 3 yr, range 6-18 yr, 530 male) underwent ultrasonic brachial artery assessment before and after 5 min of forearm ischemia. Sex differences in FMD and baseline artery diameter were assessed using mixed linear models. Baseline artery diameter was smaller in females than males [2.96 mm (95% CI: 2.92-3.00) vs. 3.24 mm (3.19-3.28), P < 0.001] and increased with age across the cohort (P < 0.001). Diameter increased between ages 6 and 17 yr in males [from 2.81 mm (2.63, 3.00) to 3.91 mm (3.68, 4.14)] but plateaued at age 12 yr in females. Males had a lower FMD [7.62% (7.33-7.91) vs. 8.31% (7.95-8.66), P = 0.024], specifically at ages 17 and 18 yr. There was a significant effect of age on FMD (P = 0.023), with a reduction in FMD apparent postpuberty in males. In conclusion, the brachial artery increases structurally with age in both sexes; however, there are sex differences in the timing and rate of growth, in line with typical sex-specific adolescent growth patterns. Males have a lower FMD than females, and FMD appears to decline with age; however, these findings are driven by reductions in FMD as males near maturity. The use of age- and sex-specific FMD data may therefore not be pertinent in childhood and adolescence. Copyright © 2015 the American Physiological Society.

  3. Impaired handgrip exercise-induced brachial artery flow-mediated dilation in young obese males.

    PubMed

    Slattery, David J; Stuckless, Troy J R; King, Trevor J; Pyke, Kyra E

    2016-05-01

    Flow mediated dilation (FMD) stimulated by different shear stress stimulus profiles may recruit distinct transduction mechanisms, and provide distinct information regarding endothelial function. The purpose of this study was to determine whether obesity influences brachial artery FMD differently depending on the shear stress profile used for FMD assessment. The FMD response to a brief, intermediate, and sustained shear stress profile was assessed in obese (n = 9) and lean (n = 19) young men as follows: brief stimulus, standard reactive hyperemia (RH) following a 5 min forearm occlusion (5 min RH); intermediate stimulus, RH following a 15 min forearm occlusion (15 min RH); sustained stimulus, 10 min of handgrip exercise (HGEX). Brachial artery diameter and mean shear stress were assessed using echo and Doppler ultrasound, respectively, during each FMD test. There was no group difference in HGEX shear stress (p = 0.390); however, the obese group had a lower HGEX-FMD (5.2 ± 3.0% versus 11.5 ± 4.4%, p < 0.001). There was no group difference in 5 min RH-FMD (p = 0.466) or 15 min RH-FMD (p = 0.181); however, the shear stress stimulus was larger in the obese group. After normalization to the stimulus the 15 min RH-FMD (p = 0.002), but not the 5 min RH-FMD (p = 0.118) was lower in the obese group. These data suggest that obesity may have a more pronounced impact on the endothelium's ability to respond to prolonged increases in shear stress.

  4. [Maternal endothelial function in the course of pregnancy and postpartum - ultrasound-based longitudinal assessment using flow-mediated dilatation (FMD)].

    PubMed

    Seeliger, C; Brueckmann, A; Schleußner, E

    2012-12-01

    NO-triggered vasodilatation decreases peripheral vascular resistance in pregnancy. Using a noninvasive ultrasound technique, flow-mediated vasodilatation can be quantified. We used this technique to detect changes in endothelial function during pregnancy and postpartum. In a prospective longitudinal study 16 healthy pregnant women were assessed for flow-mediated dilatation of the brachial artery during pregnancy (first trimester T 1 < 14th gestational week, second trimester T 2 ≥ 14th - 27th gestational week, third trimester T 3 ≥  28th gestational week) and postpartum (> 6 weeks postpartum). As a control group, flow-mediated dilatation was determined in 19 healthy non-pregnant women. Flow-mediated dilatation (%) increased significantly in normal human pregnancy from the first trimester (T1 8.0 ± 5.58 vs. T 2 15.2 ± 5.19, p < 0.003) to the second trimester and reached its maximum in mid-trimester. Towards the end of pregnancy, flow-mediated dilatation decreased significantly (T2 vs. T 3 9.15 ± 3.61, p < 0.004). Mean values of flow-mediated dilatation are significantly higher during the second and third trimester of pregnancy compared to non-pregnant controls (T2 vs. NP 6.17 ± 4.39, p < 0.001; T 3 vs. NP, p < 0.047). Postpartum flow-mediated dilatation decreased to values of early pregnancy. During pregnancy maternal endothelial function shows an increase in flow-mediated dilatation and then reverts postpartum. Using ultrasound-based measurement of flow-mediated dilatation, these physiological changes in pregnancy can be reliably detected. © Georg Thieme Verlag KG Stuttgart · New York.

  5. Endothelial function is impaired in relation to alcohol intake even in the case of light alcohol consumption in Asian men; Flow-mediated Dilation Japan (FMD-J) Study.

    PubMed

    Oda, Nozomu; Kajikawa, Masato; Maruhashi, Tatsuya; Iwamoto, Yumiko; Kishimoto, Shinji; Matsui, Shogo; Hidaka, Takayuki; Kihara, Yasuki; Chayama, Kazuaki; Goto, Chikara; Aibara, Yoshiki; Nakashima, Ayumu; Noma, Kensuke; Tomiyama, Hirofumi; Takase, Bonpei; Yamashina, Akira; Higashi, Yukihito

    2017-03-01

    Heavy drinking should be a predictor of endothelial dysfunction. However, there is little information on the effects of light to moderate alcohol consumption on endothelial function. The purpose of this study was to estimate the effects of dose-dependent alcohol consumption on endothelial function. We measured flow-mediated vasodilation (FMD) in 2734 men aged 21-81years who provided information on alcohol intake at 3 general hospitals. The subjects were divided into 5 groups; non-drinkers (0g/week), light drinkers (>0 to 140g/week), moderate drinkers (>140 to 280g/week), heavy drinkers (>280 to 420g/week), and excessive heavy drinkers (>420g/week). FMD showed a gradual decrease in accordance with alcohol consumption in the entire study population (non-drinkers, 6.6±3.4%; light drinkers, 6.2±3.0%; moderate drinkers, 6.0±3.0%; heavy drinkers, 5.5±2.9%; excessive heavy drinkers, 5.3±3.0%; P<0.001). There was a significant difference in FMD between the light alcohol drinker group and the non-drinker group (P=0.015). After adjustment for other risk factors, the odds of having FMD in the lowest quartile was found to be significantly increased in the 4 drinker groups than in the non-drinker group: light (OR, 1.38; 95% CI, 1.10 to 1.75), moderate (OR, 1.36; 95% CI, 1.01 to 1.82), heavy (OR, 2.05; 95% CI, 1.46 to 2.87), excessive (OR, 2.04; 95% CI, 1.43 to 2.89). These findings suggest that FMD is impaired in relation to alcohol consumption and that FMD is significantly smaller even in light alcohol drinkers than in non-drinkers. Alcohol intake per se may be harmful for vascular function. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  6. Endothelial function and sleep: associations of flow-mediated dilation with perceived sleep quality and rapid eye movement (REM) sleep.

    PubMed

    Cooper, Denise C; Ziegler, Michael G; Milic, Milos S; Ancoli-Israel, Sonia; Mills, Paul J; Loredo, José S; Von Känel, Roland; Dimsdale, Joel E

    2014-02-01

    Endothelial function typically precedes clinical manifestations of cardiovascular disease and provides a potential mechanism for the associations observed between cardiovascular disease and sleep quality. This study examined how subjective and objective indicators of sleep quality relate to endothelial function, as measured by brachial artery flow-mediated dilation (FMD). In a clinical research centre, 100 non-shift working adults (mean age: 36 years) completed FMD testing and the Pittsburgh Sleep Quality Index, along with a polysomnography assessment to obtain the following measures: slow wave sleep, percentage rapid eye movement (REM) sleep, REM sleep latency, total arousal index, total sleep time, wake after sleep onset, sleep efficiency and apnea-hypopnea index. Bivariate correlations and follow-up multiple regressions examined how FMD related to subjective (i.e., Pittsburgh Sleep Quality Index scores) and objective (i.e., polysomnography-derived) indicators of sleep quality. After FMD showed bivariate correlations with Pittsburgh Sleep Quality Index scores, percentage REM sleep and REM latency, further examination with separate regression models indicated that these associations remained significant after adjustments for sex, age, race, hypertension, body mass index, apnea-hypopnea index, smoking and income (Ps < 0.05). Specifically, as FMD decreased, scores on the Pittsburgh Sleep Quality Index increased (indicating decreased subjective sleep quality) and percentage REM sleep decreased, while REM sleep latency increased (Ps < 0.05). Poorer subjective sleep quality and adverse changes in REM sleep were associated with diminished vasodilation, which could link sleep disturbances to cardiovascular disease.

  7. Measuring flow-mediated dilation through transverse and longitudinal imaging: comparison and validation of methods

    NASA Astrophysics Data System (ADS)

    Stroz, Marianne J.; Fenster, Aaron

    2010-11-01

    Three-dimensional ultrasound images (3DUS), having two spatial and one temporal dimension, were taken of the brachial artery during baseline conditions, in the transverse and longitudinal planes. The transverse images were analyzed by three different techniques used to quantify flow-mediated dilation (FMD): (1) measuring vessel area manually (TIMA), (2) measuring vessel area semi-automatically (TISA) and (3) measuring vessel diameter (TID). The inter- and intra-observer variability and transducer repositioning variability of each method were compared to each other and to the variability of measurements taken using the traditional method of measuring vessel FMD through measuring vessel diameter on longitudinal images (LID). The percent coefficient-of-variation describing the inter-observer variability (COVinter) was similar for the methods, indicating that each method was equally reproducible by the different observers. The percent coefficient-of-variation describing the intra-observer variability (COVintra) and the smallest detectable percent change in diameter (Δdintra) for each method indicated that TID was the most precise at measuring vessel diameter, and could measure the smallest changes in diameter between successive measurements (COVintra = 0.31%, Δdintra = 0.87%). LID performed the poorest (COVintra = 0.57%, Δdintra = 1.59%). The percent coefficient-of-variation describing transducer repositioning (COVrep) and the smallest detectable percent change in FMD over time (ΔFMD) for each method indicated that TIMA was the most reproducible method (COVrep = 2.35%, ΔFMD = 6.52%) closely followed by TISA. TID performed the poorest (COVrep = 5.37%, ΔFMD = 14.89%). TIMA and TISA were found not to be statistically different so we suggest TISA as the method of choice to maximize reproducibility between measurements over time, as it is faster and simpler to perform. In each experiment it was clear that transverse imaging introduced equal or less variability into

  8. Measuring flow-mediated dilation through transverse and longitudinal imaging: comparison and validation of methods.

    PubMed

    Stroz, Marianne J; Fenster, Aaron

    2010-11-07

    Three-dimensional ultrasound images (3DUS), having two spatial and one temporal dimension, were taken of the brachial artery during baseline conditions, in the transverse and longitudinal planes. The transverse images were analyzed by three different techniques used to quantify flow-mediated dilation (FMD): (1) measuring vessel area manually (TIMA), (2) measuring vessel area semi-automatically (TISA) and (3) measuring vessel diameter (TID). The inter- and intra-observer variability and transducer repositioning variability of each method were compared to each other and to the variability of measurements taken using the traditional method of measuring vessel FMD through measuring vessel diameter on longitudinal images (LID). The percent coefficient-of-variation describing the inter-observer variability (COV(inter)) was similar for the methods, indicating that each method was equally reproducible by the different observers. The percent coefficient-of-variation describing the intra-observer variability (COV(intra)) and the smallest detectable percent change in diameter (Δd(intra)) for each method indicated that TID was the most precise at measuring vessel diameter, and could measure the smallest changes in diameter between successive measurements (COV(intra) = 0.31%, Δd(intra) = 0.87%). LID performed the poorest (COV(intra) = 0.57%, Δd(intra) = 1.59%). The percent coefficient-of-variation describing transducer repositioning (COV(rep)) and the smallest detectable percent change in FMD over time (ΔFMD) for each method indicated that TIMA was the most reproducible method (COV(rep) = 2.35%, ΔFMD = 6.52%) closely followed by TISA. TID performed the poorest (COV(rep) = 5.37%, ΔFMD = 14.89%). TIMA and TISA were found not to be statistically different so we suggest TISA as the method of choice to maximize reproducibility between measurements over time, as it is faster and simpler to perform. In each experiment it was clear that transverse imaging introduced equal or less

  9. Sex impacts the flow-mediated dilation response to acute aerobic exercise in older adults.

    PubMed

    Yoo, Jeung-Ki; Pinto, Michelle M; Kim, Han-Kyul; Hwang, Chueh-Lung; Lim, Jisok; Handberg, Eileen M; Christou, Demetra D

    2017-05-01

    There is growing evidence of sex differences in the chronic effect of aerobic exercise on endothelial function (flow-mediated dilation; FMD) in older adults, but whether there are sex differences also in the acute effect of aerobic exercise on FMD in older adults is unknown. The purpose of this study was to test the hypothesis that sex modulates the FMD response to acute aerobic exercise in older adults. Thirteen older men and fifteen postmenopausal women (67±1 vs. 65±2years, means±SE, P=0.6), non-smokers, free of major clinical disease, participated in this randomized crossover study. Brachial artery FMD was measured: 1) prior to exercise; 2) 20min after a single bout of high-intensity interval training (HIIT; 40min; 4×4 intervals 90% peak heart rate (HRpeak)), moderate-intensity continuous training (MICT; 47min 70% HRpeak) and low-intensity continuous training (LICT; 47min 50% HRpeak) on treadmill; and 3) following 60-min recovery from exercise. In older men, FMD was attenuated by 45% following HIIT (5.95±0.85 vs. 3.27±0.52%, P=0.003) and by 37% following MICT (5.97±0.87 vs. 3.73±0.47%, P=0.03; P=0.9 for FMD response to HIIT vs. MICT) and was normalized following 60-min recovery (P=0.99). In postmenopausal women, FMD did not significantly change in response to HIIT (4.93±0.55 vs. 6.31±0.57%, P=0.14) and MICT (5.32±0.62 vs. 5.60±0.68%, P=0.99). In response to LICT, FMD did not change in postmenopausal women nor older men (5.21±0.64 vs. 6.02±0.73%, P=0.7 and 5.70±0.80 vs. 5.55±0.67%, P=0.99). In conclusion, sex and exercise intensity influence the FMD response to acute aerobic exercise in older adults. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Flow-mediated Dilation: Can New Approaches Provide Greater Mechanistic Insight into Vascular Dysfunction in Preeclampsia and Other Diseases?

    PubMed Central

    Weissgerber, Tracey L.

    2015-01-01

    Endothelial dysfunction is a key feature of preeclampsia, and may contribute to increased cardiovascular disease risk years after pregnancy. Flow-mediated dilation (FMD) is a non-invasive endothelial function test that predicts cardiovascular event risk. New protocols allow researchers to measure three components of the FMD response: FMD, low flow-mediated constriction and the shear stimulus. This review encourages researchers to think beyond “low FMD” by examining how these three components may provide additional insights into the mechanisms and location of vascular dysfunction. The review then examines what FMD studies reveal about vascular dysfunction in preeclampsia, while highlighting opportunities to gain greater mechanistic insight from new protocols. Studies using traditional protocols show that FMD is low in mid-pregnancy prior to preeclampsia, at diagnosis, and for three years post-partum. However, FMD returns to normal by ten years post-partum. Studies using new protocols are needed to gain more mechanistic insight. PMID:25182159

  11. Short-term exercise training improves flow-mediated dilation and circulating angiogenic cell number in older sedentary adults.

    PubMed

    Landers-Ramos, Rian Q; Corrigan, Kelsey J; Guth, Lisa M; Altom, Christine N; Spangenburg, Espen E; Prior, Steven J; Hagberg, James M

    2016-08-01

    Cardiovascular disease risk increases with age due, in part, to impaired endothelial function and decreased circulating angiogenic cell (CAC) number and function. We sought to determine if 10 days of aerobic exercise training improves endothelial function, CAC number, and intracellular redox balance in older sedentary adults. Eleven healthy subjects (4 men, 7 women), 61 ± 2 years of age participated in 60 min of aerobic exercise at 70% maximal oxygen consumption for 10 consecutive days while maintaining body weight. Before and after training, endothelial function was measured as flow-mediated dilation of the brachial artery and fasting blood was drawn to enumerate 3 CAC subtypes. Intracellular reactive oxygen species (ROS) and nitric oxide (NO) in CD34+ CACs were measured using fluorescent probes and reinforced via real-time quantitative polymerase chain reaction. Flow-mediated dilation improved significantly following training (10% ± 1.3% before vs. 16% ± 1.4% after training; P < 0.05). Likewise, CD34+/KDR+ number increased 104% and KDR+ number increased 151% (P < 0.05 for both), although CD34+ number was not significantly altered (P > 0.05). Intracellular NO and ROS levels in CD34+ CACs were not different after training (P > 0.05 for both). Messenger RNA expression of SOD1, endothelial nitric oxide synthase, and NADPH oxidase 2 and neutrophil cytosolic factor 1 in CD34+ CACs was not significantly altered with training (P > 0.05). In conclusion, 10 consecutive days of aerobic exercise increased flow-mediated dilation and CAC number in older, previously sedentary adults, but did not affect intracellular redox balance in CD34+ CACs. Overall, these data indicate that even short-term aerobic exercise training can have a significant impact on cardiovascular disease risk factors.

  12. A comparison of Doppler waveform parameters versus flow-mediated vascular dilation of the brachial artery in pregnant women.

    PubMed

    Landres, Inna V; Small, Maria; Sirjusingh, Adesh; Ramsewak, Samuel; Williams, Keith P

    2014-07-01

    Flow mediated dilation of the brachial artery is impaired with endothelial dysfunction. We previously identified that brachial artery waveforms were changed in preeclamptic women. We therefore sought to compare Doppler waveform analysis with flow mediated vascular dilation (FMVD) measurements in pregnant women. A cross sectional study of 71 pregnant women at >20weeks gestation comparing FMVD measurements with Doppler waveform parameters was performed. Research was conducted at three hospitals and two geographic settings; (1) Yale-New Haven Hospital in New Haven, CT, (2) Mount Hope Maternity and (3) Port of Spain General Hospital in Trinidad. Brachial artery Doppler waveform measurements were done at baseline and 90s post cuff-release. From the Doppler waveforms we assessed percent change in Peak Systolic Velocity (% ΔPSV), systolic acceleration, acceleration time and pulsatility index and compared them with the percent change in FMVD. Statistical analysis using Student's t tests and correlation coefficient was done as necessary. Correlation analysis between the % change in the Doppler waveform parameters and the % change in mean FMVD identified only the waveform parameter of % ΔPSV as significantly correlated (p=0.040). FMVD remains the gold standard for assessment of endothelial dysfunction. A correlation was observed between the Doppler measured % ΔPSV and FMVD, which may allow it to be used to assess endothelial dysfunction changes under different conditions was identified. Copyright © 2014 International Society for the Study of Hypertension in Pregnancy. Published by Elsevier B.V. All rights reserved.

  13. Vascular function assessed by passive leg movement and flow-mediated dilation: initial evidence of construct validity.

    PubMed

    Rossman, Matthew J; Groot, H Jonathan; Garten, Ryan S; Witman, Melissa A H; Richardson, Russell S

    2016-11-01

    The vasodilatory response to passive leg movement (PLM) appears to provide a novel, noninvasive assessment of vascular function. However, PLM has yet to be compared with the established noninvasive assessment of vascular health, flow-mediated dilation (FMD). Therefore, as an initial evaluation of the construct validity of PLM and upright seated and supine PLM as well as brachial (BA) and superficial femoral (SFA) artery FMDs were performed in 10 young (22 ± 1) and 30 old (73 ± 2) subjects. During upright seated PLM, the peak change in leg blood flow (ΔLBF) and leg vascular conductance (ΔLVC) was significantly correlated with BA (r = 0.57 and r = 0.66) and SFA (r = 0.44 and r = 0.41, ΔLBF and ΔLVC, respectively) FMD. Furthermore, although the relationships were not as strong, the supine PLM response was also significantly correlated with BA (r = 0.38 and r = 0.35) and SFA (r = 0.39 and r = 0.35, ΔLBF and ΔLVC, respectively) FMD. Examination of the young and old separately, however, revealed that significant relationships persisted in both groups only for the upright seated PLM response and BA FMD (young: r = 0.73 and r = 0.77; old: r = 0.35 and r = 0.45, ΔLBF and ΔLVC, respectively). Normalizing FMD for shear rate during PLM abrogated all significant relationships between the PLM and FMD response, suggesting a role for nitric oxide (NO) in these associations. Collectively, these data indicate that PLM, particularly upright seated PLM, likely provides an index of vascular health analogous to the traditional FMD test. Given the relative ease of PLM implementation, these data have important positive implications for PLM as a clinical vascular health assessment.

  14. Brachial artery flow-mediated dilatation and carotid intima-media thickness in young ED patients with insulin resistance.

    PubMed

    Chen, S-F; Yao, F-J; Sun, X-Z; Wu, R-P; Huang, Y-P; Zheng, F-F; Yang, Q-Y; Han, D-Y; Xie, M-Q; Ding, M; Zhang, Y; Liu, G-H; Deng, C-H

    2016-09-01

    The evidence of a close relationship between cardiovascular disease and erectile dysfunction (ED) is well documented. The aim of this study is to investigate whether there is an early asymptomatic impairment of the peripheral vasculature in young ED patients without obvious cardiovascular disease. We studied a total of 261 ED patients (19-40 years old) and 40 age-matched healthy controls. All participants received questionnaires of cardiovascular risk factors and erectile function assessment, were subjected to lab tests of fasting blood sample, and underwent the ultrasonographic examination of brachial artery flow-mediated dilation (FMD) and carotid intima-media thickness (c-IMT). Insulin resistance (IR) was measured by the homeostasis model assessment of insulin resistance (HOMA-IR). Compared with normal human controls, FMD was significantly lower, whereas the average c-IMT was significantly greater in ED patients. An inverse correlation was found between FMD and mean c-IMT. The ED patients had significantly higher levels of fasting glucose, fasting insulin and HOMA-IR index, but showed relatively lower total testosterone and prolactin levels than the controls. Both FMD and c-IMT showed a significant correlation with International Index of Erectile Function-5 questionnaire (IIEF-5) score, age and HOMA-IR. Multivariate stepwise regression analysis demonstrated that age, HOMA-IR and IIEF-5 score were the risk factors associated with FMD and c-IMT. In conclusion, young ED patients in association with IR display diminished FMD and increased c-IMT. Furthermore, ED, HOMA-IR and age are independent predictors of the two subclinical atherosclerotic markers.

  15. AT1 receptor blockade prevents the decrease in conduit artery flow-mediated dilatation during NOS inhibition in humans.

    PubMed

    Bellien, Jeremy; Iacob, Michele; Eltchaninoff, Helene; Bourkaib, Ryad; Thuillez, Christian; Joannides, Robinson

    2007-06-01

    Whether AT(1) (angiotenin II type 1) receptor blockade can prevent the decrease in conduit artery FMD (flow-mediated dilatation) during NOS (nitric oxide synthase) inhibition by alternative endothelial pathways has not been explored previously in humans. In 12 healthy subjects, we measured radial artery diameter (echotracking) and flow (Doppler) during FMD induced by sustained reactive hyperaemia during a control period and following NOS inhibition [1.5 mg.min(-1).l(-1) L-NMMA (N(G)-monomethyl-L-arginine)], after a single oral administration of telmisartan (80 mg) or placebo, using a randomized double-blind cross-over design. In six volunteers, we also assessed the roles of prostacyclin and EDHF (endothelium-derived hyperpolarizing factor) during radial FMD after AT(1) receptor blockade by oral administration of aspirin (500 mg) alone, aspirin+L-NMMA or aspirin+L-NMMA+fluconazole (a cytochrome epoxygenases inhibitor; 0.37 mg.min(-1).l(-1)). Telmisartan did not affect radial artery FMD in the control period (10.9+/-0.6% with placebo compared with 9.9+/-0.7% with telmisartan), but prevented its decrease after L-NMMA (9.3+/-0.8% with placebo compared with 12.6+/-1.2% with telmisartan; P<0.05) with no modification in baseline parameters, hyperaemia and radial artery endothelium-independent dilatation to sodium nitroprusside. Moreover, in telmisartan-treated subjects, radial artery FMD, compared with control (9.0+/-1.0%), was not modified by aspirin alone (9.4+/-0.7%) or associated with L-NMMA (9.5+/-0.5%), but was reduced by the combination of aspirin, L-NMMA and fluconazole (7.5+/-0.6%; P<0.05). These results demonstrate that AT(1) receptor blockade prevents the decrease in conduit artery FMD during NOS inhibition in humans, suggesting the development of a compensatory endothelial mechanism. This mechanism appears to be independent of prostacyclin and could possibly be related to an EDHF release.

  16. A registration-based approach to quantify flow-mediated dilation (FMD) of the brachial artery in ultrasound image sequences.

    PubMed

    Frangi, Alejandro F; Laclaustra, Martín; Lamata, Pablo

    2003-11-01

    Flow-mediated dilation (FMD) offers a mechanism to characterize endothelial function and, therefore, may play a role in the diagnosis of cardiovascular diseases. Computerized analysis techniques are very desirable to give accuracy and objectivity to the measurements. Virtually all methods proposed up to now to measure FMD rely on accurate edge detection of the arterial wall, and they are not always robust in the presence of poor image quality or image artifacts. A novel method for automatic dilation assessment based on a global image analysis strategy is presented. We model interframe arterial dilation as a superposition of a rigid motion and a scaling factor perpendicular to the artery. Rigid motion can be interpreted as a global compensation for patient and probe movements, an aspect that has not been sufficiently studied before. The scaling factor explains arterial dilation. The ultrasound sequence is analyzed in two phases using image registration to recover both transformation models. Temporal continuity in the registration parameters along the sequence is enforced with a Kalman filter since the dilation process is known to be a gradual physiological phenomenon. Comparing automated and gold standard measurements (average of manual measurements) we found a negligible bias (0.05%FMD) and a small standard deviation (SD) of the differences (1.05%FMD). These values are comparable with those obtained from manual measurements (bias = 0.23%FMD, SD(intra-obs) = 1.13%FMD, SD(inter-obs) 1.20%FMD). The proposed method offers also better reproducibility (CV = 0.40%) than the manual measurements (CV = 1.04%).

  17. Effect of Selective Mineralocorticoid Receptor Blockade on Flow-Mediated Dilation and Insulin Resistance in Older Adults with Metabolic Syndrome.

    PubMed

    Hwang, Moon-Hyon; Yoo, Jeung-Ki; Luttrell, Meredith; Meade, Thomas H; English, Mark; Christou, Demetra D

    2015-10-01

    The prevalence of metabolic syndrome is especially high in older adults. Metabolic syndrome is associated with impaired vascular endothelial function, insulin resistance, and increased risk for cardiovascular disease but the underlying mechanisms are not fully elucidated. Plasma aldosterone is independently associated with metabolic syndrome and is linked to endothelial dysfunction and insulin resistance. Thus, we hypothesized that mineralocorticoid receptor (MR) blockade would improve flow-mediated dilation and insulin resistance in older adults with metabolic syndrome. To test this hypothesis, we conducted a balanced, randomized, double-blind, placebo-controlled, crossover study using selective MR blockade (eplerenone; 100 mg/day) for 1 month with 1 month washout in older adults with metabolic syndrome (62.6 ± 3.2 yrs; mean ± standard error). We evaluated brachial artery flow-mediated dilation (ultrasonography), oxidative stress (oxidized low-density lipoproteins and F2-isoprostanes) and insulin resistance (homeostatic model assessment). In response to MR blockade, flow-mediated dilation (5.37 ± 0.85 vs. 5.98 ± 1.29%; placebo vs. eplerenone; P = 0.4), oxidized low-density lipoproteins (51.6 ± 11.5 vs. 56.1 ± 10.9 U/L; P = 0.6), and F2-isoprostanes (0.07 ± 0.02 vs. 0.06 ± 0.01 pg/mL; P = 0.3) did not improve. Insulin resistance also did not change following MR blockade (1.04 ± 0.26 vs. 1.38 ± 0.50; P = 0.6). However, MR blockade resulted in a large reduction (10 mmHg) in systolic blood pressure (140 ± 6 vs. 130 ± 6 mmHg; P = 0.02), with no significant change in diastolic blood pressure (81 ± 3 vs. 75 ± 2 mmHg; P = 0.2). Our data do not support a contributing role for MRs in endothelial dysfunction and insulin resistance in older adults with metabolic syndrome. However, our findings suggest MR activation is an important contributor to systolic hypertension in

  18. Exposure-response modeling of flow-mediated dilation provides an unbiased and informative measure of endothelial function.

    PubMed

    Van Brackle, Charles Henry; Harris, Ryan A; Hallow, Karen Melissa

    2016-12-15

    The brachial artery flow-mediated dilation (FMD) test is the most widely utilized, method to evaluate endothelial function non-invasively in humans by calculating the percent change in diameter (FMD%). However, the underutilized velocity and diameter time-course data coupled with confounding influences in shear exposure, noise, and upward bias make the FMD test less desirable. In this study, we developed an exposure-response model-based approach that not only quantifies FMD based on the rich velocity and diameter data, it overcomes previously acknowledged challenges. FMD data were obtained from 15 apparently healthy participants, each exposed to 4 different cuff occlusion durations. The velocity response following cuff release was described by an exponential model with two parameters defining peak velocity and rate of decay. Shear exposure derived from velocity was used to drive the diameter response model, which consists of additive constriction and dilation terms. Three parameters describing distinct aspects of the vascular response to shear (magnitude of the initial constriction response, and magnitude and time constant of the dilation response) were estimated for both the individuals and population. These parameters are independent of shear exposure. Thus, this approach produces identifiable and physiologically meaningful parameters that may provide additional information for comparing differences between experimental groups or over time, and provides a means to completely account for shear exposure.

  19. Noninvasive Measurement of Transient Change in Viscoelasticity Due to Flow-Mediated Dilation Using Automated Detection of Arterial Wall Boundaries

    NASA Astrophysics Data System (ADS)

    Ikeshita, Kazuki; Hasegawa, Hideyuki; Kanai, Hiroshi

    2011-07-01

    We measured the stress-strain relationship of the radial arterial wall during a heartbeat noninvasively. In our previous study, the viscoelasticity of the intima-media region was estimated from the stress-strain relationship, and the transient change in viscoelasticity due to flow-mediated dilation (FMD) was estimated. In this estimation, it is necessary to detect the lumen-intima boundary (LIB) and the media-adventitia boundary (MAB). To decrease the operator dependence, in the present study, a method is proposed for automatic and objective boundary detection based on template matching between the measured and adaptive model ultrasonic signals. Using this method, arterial wall boundaries were appropriately detected in in vivo experiments. Furthermore, the transient change in viscoelasticity estimated from the stress-strain relationship was similar to that obtained manually. These results show the feasibility of the proposed method for automatic boundary detection enabling an objective and appropriate analysis of the transient change in viscoelasticity due to FMD.

  20. Dose-dependent increases in flow-mediated dilation following acute cocoa ingestion in healthy older adults

    PubMed Central

    Feehan, Robert P.; Kunselman, Allen R.; Preston, Amy G.; Miller, Debra L.; Lott, Mary E. J.

    2011-01-01

    An inverse relation exists between intake of flavonoid-rich foods, such as cocoa, and cardiovascular-related mortality. Favorable effects of flavonoids on the endothelium may underlie these associations. We performed a randomized, double-blind, placebo-controlled study to test the hypothesis that acute cocoa ingestion dose dependently increases endothelium-dependent vasodilation, as measured by an increase in brachial artery flow-mediated dilation (FMD), in healthy older adults. Measurements were obtained before (preingestion) and after (1- and 2-h postingestion) ingestion of 0 (placebo), 2, 5, 13, and 26 g of cocoa in 23 adults (63 ± 2 yr old, mean ± SE). Changes in brachial artery FMD 1- and 2-h postingestion compared with preingestion were used to determine the effects of cocoa. FMD was unchanged 1 (Δ−0.3 ± 0.2%)- and 2-h (Δ0.1 ± 0.1%) after placebo (0 g cocoa). In contrast, FMD increased both 1-h postingestion (2 g cocoa Δ0.0 ± 0.2%, 5 g cocoa Δ0.8 ± 0.3%, 13 g cocoa Δ1.0 ± 0.3%, and 26 g cocoa Δ1.6 ± 0.3%: P < 0.05 compared with placebo for 5, 13, and 26 g cocoa) and 2-h postingestion (2 g cocoa Δ0.5 ± 0.3%, 5 g cocoa Δ1.0 ± 0.3%, 13 g cocoa Δ1.4 ± 0.2%, and 26 g cocoa Δ2.5 ± 0.4%: P < 0.05 compared with placebo for 5, 13, and 26 g cocoa) on the other study days. A serum marker of cocoa ingestion (total epicatechin) correlated with increased FMD 1- and 2-h postingestion (r = 0.44–0.48; both P < 0.05). Collectively, these results indicate that acute cocoa ingestion dose dependently increases brachial artery FMD in healthy older humans. These responses may help to explain associations between flavonoid intake and cardiovascular-related mortality in humans. PMID:21903881

  1. Effect of Folic Acid and Betaine Supplementation on Flow-Mediated Dilation: A Randomized, Controlled Study in Healthy Volunteers

    PubMed Central

    Olthof, Margreet R; Bots, Michiel L; Katan, Martijn B; Verhoef, Petra

    2006-01-01

    Objectives: We investigated whether lowering of fasting homocysteine concentrations, either with folic acid or with betaine supplementation, differentially affects vascular function, a surrogate marker for risk of cardiovascular disease, in healthy volunteers. As yet, it remains uncertain whether a high concentration of homocysteine itself or whether a low folate status—its main determinant—is involved in the pathogenesis of cardiovascular disease. To shed light on this issue, we performed this study. Design: This was a randomized, placebo-controlled, double-blind, crossover study. Setting: The study was performed at Wageningen University in Wageningen, the Netherlands. Participants: Participants were 39 apparently healthy men and women, aged 50–70 y. Interventions: Participants ingested 0.8 mg/d of folic acid, 6 g/d of betaine, and placebo for 6 wk each, with 6-wk washout in between. Outcome Measures: At the end of each supplementation period, plasma homocysteine concentrations and flow-mediated dilation (FMD) of the brachial artery were measured in duplicate. Results: Folic acid supplementation lowered fasting homocysteine by 20% (−2.0 μmol/l, 95% confidence interval [CI]: −2.3; −1.6), and betaine supplementation lowered fasting plasma homocysteine by 12% (−1.2 μmol/l; −1.6; −0.8) relative to placebo. Mean (± SD) FMD after placebo supplementation was 2.8 (± 1.8) FMD%. Supplementation with betaine or folic acid did not affect FMD relative to placebo; differences relative to placebo were −0.4 FMD% (95%CI, −1.2; 0.4) and −0.1 FMD% (−0.9; 0.7), respectively. Conclusions: Folic acid and betaine supplementation both did not improve vascular function in healthy volunteers, despite evident homocysteine lowering. This is in agreement with other studies in healthy participants, the majority of which also fail to find improved vascular function upon folic acid treatment. However, homocysteine or folate might of course affect cardiovascular

  2. Combined B-Mode and Multigate Spectral Doppler-Mode Imaging for Flow-Mediated Dilation Investigation

    NASA Astrophysics Data System (ADS)

    Francalanci, Lorenzo; Palombo, Carlo; Ghiadoni, Lorenzo; Bini, Giacomo; Bassi, Luca; Tortoli, Piero

    Flow-mediated dilation (FMD) is an established non-invasive method to assess the endothelial function by ultrasound. Blood flow in the brachial artery is restricted by a cuff for about 5 min: during the reactive hyperemia following occlusion release, the consequent increase in wall shear stress stimulates the endothelial cells to release nitric oxide, a powerful vasodilator that causes relaxation of tunica media smooth muscle. By measuring the arterial diameter change induced by reactive hyperemia, a possible endothelial dysfunction can be detected. The traditional approach consists in the evaluation of arterial diameter changes, while the shear stress increase (i.e. the stimulus for dilation) has not been directly estimated so far. This paper describes an approach to simultaneously measure the wall shear rate (WSR), i.e. the blood velocity gradient near the walls, and the associated diameter changes. The WSR is measured through multigate spectral Doppler (MSD) analysis while B-Mode images are processed to estimate the instantaneous diameter. This approach was implemented in the ULtrasound Advanced Open Platform (ULA-OP), which can be programmed to arbitrarily interleave B- and PW Doppler- Modes. The method implementation and the results of a clinical validation over 15 healthy volunteers are reported.

  3. Flow-mediated dilatation, using time course data, shows maturation of the brachial artery from young children to mid-adolescents.

    PubMed

    Kontos, Anna; Pamula, Yvonne; Martin, James; Gent, Roger; Lushington, Kurt; Baumert, Mathias; Willoughby, Scott; Richardson, Malcolm; Couper, Jennifer; Kennedy, Declan

    2015-03-01

    Flow-mediated dilatation (FMD) is a tool widely used to measure arterial responsiveness to sheer stress. However, there is scant literature to show how the peripheral arterial response changes as the vascular system matures. One reason for this is that the feasibility of measuring FMD in younger children has not been established. The aim of the present study was to assess brachial artery function at rest and during the FMD response after 4 min ischaemia of the forearm in children aged 6-15 years. Time to reach maximum FMD (FMDmax ) was found to be correlated with age (r = 0.4, P < 0.05), resting brachial artery diameter (r = 0.4, P < 0.05), height (r = 0.4, P < 0.05), body mass index (BMI; r = 0.45, P < 0.05), body surface area (r = 0.44, P < 0.05) and resting blood flow (r = 0.37, P < 0.05). However, there was no correlation between the traditional FMD response at 60 s or FMD maximal dilation and age, resting brachial artery diameter, height, weight, BMI, body surface area and resting blood flow. In conclusion, the time taken to reach the maximal dilation response is related to age, brachial artery luminal diameter and body habitus, but not the traditional measure of FMD response at 60 s or the maximal dilatation percentage. © 2014 Wiley Publishing Asia Pty Ltd.

  4. Transition in the mechanism of flow-mediated dilation with aging and development of coronary artery disease.

    PubMed

    Beyer, Andreas M; Zinkevich, Natalya; Miller, Bradley; Liu, Yanping; Wittenburg, April L; Mitchell, Michael; Galdieri, Ralph; Sorokin, Andrey; Gutterman, David D

    2017-01-01

    In microvessels of patients with coronary artery disease (CAD), flow-mediated dilation (FMD) is largely dependent upon the endothelium-derived hyperpolarizing factor H2O2. The goal of this study is to examine the influence of age and presence or absence of disease on the mechanism of FMD. Human coronary or adipose arterioles (~150 µm diameter) were prepared for videomicroscopy. The effect of inhibiting COX [indomethacin (Indo) or NOS (L-NAME), eliminating H2O2 (polyethylene glycol-catalase (PEG-CAT)] or targeting a reduction in mitochondrial ROS with scavengers/inhibitors [Vitamin E (mtVitamin E); phenylboronic acid (mtPBA)] was determined in children aged 0-18 years; young adults 19-55 years; older adults >55 years without CAD, and similarly aged adults with CAD. Indo eliminated FMD in children and reduced FMD in younger adults. This response was mediated mainly by PGI2, as the prostacyclin-synthase-inhibitor trans-2-phenyl cyclopropylamine reduced FMD in children and young adults. L-NAME attenuated dilation in children and younger adults and eliminated FMD in older adults without CAD, but had no effect on vessels from those with CAD, where mitochondria-derived H2O2 was the primary mediator. The magnitude of dilation was reduced in older compared to younger adults independent of CAD. Exogenous treatment with a sub-dilator dose of NO blocked FMD in vessels from subjects with CAD, while prolonged inhibition of NOS in young adults resulted in a phenotype similar to that observed in disease. The mediator of coronary arteriolar FMD evolves throughout life from prostacyclin in youth, to NO in adulthood. With the onset of CAD, NO-inhibitable release of H2O2 emerges as the exclusive mediator of FMD. These findings have implications for use of pharmacological agents, such as nonsteroidal anti-inflammatory agents in children and the role of microvascular endothelium in cardiovascular health.

  5. Fibrate therapy and flow-mediated dilation: A systematic review and meta-analysis of randomized placebo-controlled trials.

    PubMed

    Sahebkar, Amirhossein; Giua, Renato; Pedone, Claudio; Ray, Kausik K; Vallejo-Vaz, Antonio J; Costanzo, Luisa

    2016-09-01

    Flow-mediated dilation (FMD) of the brachial artery reflects endothelium-dependent vasodilator function; since it correlates with coronary endothelial function, its reduction could predict cardiovascular events. Several studies have investigated the potential impact of fibrates therapy on endothelial function, but clinical findings have not been fully consistent. We aimed to conduct a meta-analysis of randomized placebo-controlled trials in order to clarify whether fibrate therapy could improve endothelial function. A systematic search in PubMed-Medline, SCOPUS, Web of Science and Google Scholar databases was performed to identify randomized placebo-controlled trials investigating the effect of fibrates on endothelial function as estimated by FMD. A random-effects model and generic inverse variance method were used for meta-analysis. Sensitivity analysis, risk of bias evaluation, and publication bias assessment were carried out using standard methods. Random-effects meta-regression was used to evaluate the impact of treatment duration on the estimated effect size. Fifteen trials with a total of 556 subjects met the eligibility criteria. Fibrate therapy significantly improves FMD (weighted mean difference [WMD]: 1.64%, 95% CI: 1.15, 2.13, p<0.001) and the result was confirmed in both subgroups with treatment durations ≤8 weeks (WMD: 1.35%, 95% CI: 0.85, 1.86, p<0.001) and >8 weeks (WMD: 2.55%, 95% CI: 1.21, 3.89, p<0.001). When the analysis was stratified according to the fibrate type, a significant effect was observed with fenofibrate but not with gemfibrozil, though difference between the two subgroups was not significant. Meta-analysis of data from trials where nitrate mediated dilation (NMD) was available did not suggest a significant change in NMD following treatment with fibrates. The results of this meta-analysis suggest that fibrates may exert beneficial effects on endothelial function, even over a short-term treatment course.

  6. SALT LOADING HAS A MORE DELETERIOUS EFFECT ON FLOW-MEDIATED DILATION IN SALT-RESISTANT MEN THAN WOMEN

    PubMed Central

    Lennon-Edwards, S.; Ramick, M.G.; Matthews, E.L.; Brian, M.S.; Farquhar, W.B.; Edwards, D.G.

    2014-01-01

    Background and Aims Dietary sodium loading has been shown to adversely impact endothelial function independently of blood pressure (BP). However, it is unknown whether dietary sodium loading impacts endothelial function differently in men as compared to women. The aim of this study was to test the hypothesis that endothelial-dependent dilation (EDD) would be lower in men as compared to women in response to a high sodium diet. Methods and Results Thirty subjects (14F, 31±2y; 16M, 29±2y) underwent a randomized, crossover, controlled diet study consisting of 7 days of low sodium (LS; 20 mmol/day) and 7 days of high sodium (HS; 300–350 mmol/day). Salt-resistance was determined by a change in 24-hr mean arterial pressure (MAP)≤ 5 mmHg between HS and LS as assessed on day 7 of each diet. Blood and 24-hr urine were also collected and EDD was assessed by brachial artery flow-mediated dilation(FMD). By design, MAP was not different between LS and HS conditions and urinary sodium excretion increased on HS diet (p<0.01). FMD did not differ between men and women on the LS diet (10.2±0.65 vs. 10.7±0.83; p>0.05) and declined in both men and women on HS (p<0.001). However, FMD was lower in men as compared to women on HS (5.7±0.5 vs. 8.6±0.86; p<0.01). Conclusions HS reduced FMD in both men and women. In response to a HS diet, FMD was lower in men compared to women suggesting a greater sensitivity of the vasculature to high sodium in men. PMID:24989702

  7. Novel non-invasive method of measurement of endothelial function: enclosed-zone flow-mediated dilatation (ezFMD).

    PubMed

    Ukawa, Teiji; Takayanagi, Tsuneo; Morimoto, Haruka; Higashi, Yukihito; Idei, Naomi; Yoshizumi, Masao; Tsuji, Toshio

    2012-12-01

    Measurement of flow-mediated dilatation (FMD) is the conventional non-invasive method for assessment of endothelial function; however, it requires an expensive ultrasound system and high levels of technical skill. Therefore, we developed a novel method for measurement of endothelial function, namely, measurement of ezFMD. ezFMD estimates the degree of vasodilatation from the oscillation signals transmitted to a sphygmomanometer cuff attached to the upper arm. The objective of this study was to validate the principle underlying the measurement of ezFMD, and to evaluate the repeatability of the ezFMD measurements. We observed the blood vessel behavior and oscillometric pattern in ten subjects. When the cuff was inflated to the level of the mean blood pressure, the oscillation amplitude increased with increasing degree of vasodilatation. In experiment to evaluate the repeatability of the ezFMD measurement, the average difference between the paired measurements was 3.7 %, the standard deviation was 11.5 %, and the average coefficient of variation value for the 11 paired measurements was 23.7 %. These results suggest the validity of the principle underlying the measurement of the ezFMD for the assessment of endothelial function. And, this study suggests that the repeatability of the ezFMD measurements is superior to that of the conventional measurement of FMD.

  8. Change in Elasticity Caused by Flow-Mediated Dilation Measured Only for Intima-Media Region of Brachial Artery

    NASA Astrophysics Data System (ADS)

    Sugimoto, Masataka; Hasegawa, Hideyuki; Kanai, Hiroshi

    2005-08-01

    Endothelial dysfunction is considered to be an initial step of arteriosclerosis [R. Ross: N. Engl. J. Med. 340 (2004) 115]. For the assessment of the endothelium function, brachial artery flow-mediated dilation (FMD) caused by increased blood flow has been evaluated with ultrasonic diagnostic equipment. In the case of conventional methods, the change in artery diameter caused by FMD is measured [M. Hashimoto et al.: Circulation 92 (1995) 3431]. Although the arterial wall has a layered structure (intima, media, and adventitia), such a structure is not taken into account in conventional methods because the change in diameter depends on the characteristic of the entire wall. However, smooth muscle present only in the media contributes to FMD, whereas the collagen-rich hard adventitia does not contribute. In this study, we measure the change in elasticity of only the intima-media region including smooth muscle using the phased tracking method [H. Kanai et al.: IEEE Trans. Ultrason. Ferroelectr. Freq. Control 43 (1996) 791]. From the change in elasticity, FMD measured only for the intima-media region by our proposed method was found to be more sensitive than that measured for the entire wall by the conventional method.

  9. A single Mediterranean meal does not impair postprandial flow-mediated dilatation in healthy men with subclinical metabolic dysregulations.

    PubMed

    Lacroix, Sébastien; Des Rosiers, Christine; Gayda, Mathieu; Nozza, Anna; Thorin, Éric; Tardif, Jean-Claude; Nigam, Anil

    2016-08-01

    Cardiovascular risk factors are known to exacerbate high-saturated fatty acid meal (HSFAM)-induced endothelial dysfunction, but the influence of subclinical metabolic dysregulations and the acute impact of a single mixed Mediterranean-type meal (MMM) remains unknown. Thus, this study has the objective to evaluate the metabolic and vascular effect of such meals in healthy subjects with or without subclinical fasting metabolic dysregulations. Twenty-eight healthy males without overt cardiovascular risk factors randomly ingested 1 of 2 isocaloric meals on separate days. Plasma metabolic markers, fatty acid (FA) profile, and endothelial function (flow-mediated dilatation; FMD) were assessed at baseline and 2 and 4 h after meal ingestion. Unsupervised hierarchical clustering identified 2 subgroups of participants (n = 11 and 17) differing by their baseline metabolic profiles. The MMM did not significantly alter postprandial endothelial function in all subjects, irrespective of baseline metabolic parameters. In contrast, the HSFAM induced postprandial endothelial dysfunction (Δ%FMDabsolute = -5.28 ± 2.54, p < 0.01 vs. MMM) in a subgroup of individuals with significantly greater body mass index, fasting insulinemia, and lipid parameters (n = 11). Finally, the postprandial plasma FA profiles were differentially enriched by the HSFAM and MMM, notably with saturated FAs and omega-3 polyunsaturated FAs, respectively. Collectively, our results highlight the detrimental impact of a single HSFAM on endothelial function in healthy individuals displaying subclinical fasting metabolic dysregulations. Such individuals could benefit from MMM, demonstrated herein to be without any acute detriment to endothelial function.

  10. The incremental value of brachial flow-mediated dilation measurements in risk stratification for incident cardiovascular events: a systematic review.

    PubMed

    Peters, Sanne A E; den Ruijter, Hester M; Bots, Michiel L

    2012-06-01

    Abstract Adequate risk assessment for cardiovascular disease (CVD) is essential as a guide to initiate drug treatment. Current methods based on traditional risk factors could be improved considerably. Although brachial flow-mediated dilation (FMD) predicts subsequent cardiovascular events, its predictive value on top of traditional risk factors is unknown. We performed a systematic review to evaluate the incremental predictive value of FMD on top of traditional risk factors in asymptomatic individuals. Using PubMed and reference tracking, three studies were identified that reported on the incremental value of FMD using change in the area under the curve (AUC). Two large cohort studies found no improvement in AUC when FMD was added to traditional risk prediction models, whereas one small case-control study found an improvement. One study used the net reclassification improvement (NRI) to assess whether FMD measurement leads to correct risk stratification in risk categories. Although this study did not find an improvement in AUC, the NRI was statistically significant. Based on the reclassification results of this study, FMD measurement might be helpful in risk prediction. Evidence supporting the use of FMD measurement in clinical practice for risk stratification for CVD on top of traditional risk factors is limited, and future studies are needed.

  11. Adherence to guidelines strongly improves reproducibility of brachial artery flow-mediated dilation.

    PubMed

    Greyling, Arno; van Mil, Anke C C M; Zock, Peter L; Green, Daniel J; Ghiadoni, Lorenzo; Thijssen, Dick H

    2016-05-01

    Brachial artery FMD is widely used as a non-invasive measure of endothelial function. Adherence to expert guidelines is believed to be of vital importance to obtain reproducible measurements. We conducted a systematic review of studies reporting on the reproducibility of the FMD in order to determine the relation between adherence to current expert guidelines for FMD measurement and its reproducibility. Medline-database was searched through July 2015 and 458 records were screened for FMD reproducibility studies reporting the mean difference and variance of repeated FMD measurements. An adherence score was assigned to each of the included studies based on reported adherence to published guidelines on the assessment of brachial artery FMD. A Typical Error Estimate (TEE) of the FMD was calculated for each included study. The relation between the FMD TEE and the adherence score was investigated by means of Pearson correlation coefficients and multiple linear regression analysis. Twenty-seven studies involving 48 study groups and 1537 subjects were included in the analyses. The adherence score ranged from 2.4 to 9.2 (out of a maximum of 10) and was strongly and inversely correlated with FMD TEE (adjusted R(2) = 0.36, P < 0.01). Use of automated edge-detection software, continuous diameter measurement, true peak diameter for %FMD calculation, a stereostatic probe holder, and higher age emerged as factors associated with a lower FMD TEE. These data demonstrate that adherence to current expert consensus guidelines and applying contemporary techniques for measuring brachial artery FMD decreases its measurement error. Copyright © 2016 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

  12. Characterization of skin dermis microcirculation in flow-mediated dilation using optical sensor with pressurization mechanism.

    PubMed

    Yamakoshi, Yoshiki; Kotani, Kazuhiko; Taniguchi, Nobuyuki; Miwa, Takashi

    2013-05-01

    Blood flows out of microvessels in the dermis when pressure higher than arterial blood pressure is applied to the fingertip, and subsequently re-flows into the microcirculation when pressure is released. Both the blood outflow and the reflow characteristics of microcirculation under pressurization are associated with microvasculature, blood and blood pressure. This study describes a novel method of measuring blood inflow and outflow characteristics of dermis microcirculation. An optical sensor, which is furnished with a 571 nm wavelength light source and a photodetector, is pressed to the skin surface using a pressure higher than the human subject's systolic arterial pressure. Hemoglobin concentration by change of the blood flow amount is estimated by the Beer-Lambert law. This method is applied to the measurement of blood inflow and outflow characteristics of microcirculation caused by reactive hyperemia after ischemia with duration of 5 min. Among three parameters evaluated, the one relating to the amplitude of pulsation shows a close correlation with conventional plethysmography, while the other two show varying time responses. Our method provides a new and useful insight into pathophysiology in health and disease conditions and may help researchers better understand the underlying mechanisms of numerous microcirculation-influenced diseases and medical conditions.

  13. Impaired Flow-Mediated Dilation Before, During and After Preeclampsia: A Systematic Review and Meta-analysis

    PubMed Central

    Weissgerber, Tracey L.; Milic, Natasa M.; Milin-Lazovic, Jelena S.; Garovic, Vesna D.

    2015-01-01

    Endothelial dysfunction is believed to play a critical role in preeclampsia, however it is unclear whether this dysfunction precedes the pregnancy or is caused by early pathophysiological events. It is also unclear for how long vascular dysfunction may persist post-partum, and whether it represents a mechanism linking preeclampsia with future cardiovascular disease. Our objective was to determine whether women with preeclampsia have worse vascular function compared to women who did not have preeclampsia by performing systematic review and meta-analysis of studies that examined endothelial dysfunction using flow-mediated dilation (FMD). We included studies published before May 29, 2015 that examined FMD before, during and after preeclampsia. Differences in FMD between study groups were evaluated by standardized mean differences. Out of 610 abstracts identified through PubMED, EMBASE and Web of Science, 37 studies were eligible for the meta-analysis. When compared to women who did not have preeclampsia, women who had preeclampsia had lower FMD prior to the development of preeclampsia (~20–29 weeks gestation), at the time of preeclampsia, and for three years post-partum, with the estimated magnitude of the effect ranging between 0.5 and 3 standard deviations. Similar effects were observed when the analysis was limited to studies that excluded women with chronic hypertension, smokers, or both. Vascular dysfunction predates preeclampsia and may contribute to its pathogenesis. Future studies should address whether vascular changes that persist after preeclamptic pregnancies may represent a mechanistic link with the increased risk for future cardiovascular disease. PMID:26711737

  14. Acute effects of sildenafil on flow mediated dilatation and cardiovascular autonomic nerve function in type 2 diabetic patients.

    PubMed

    Stirban, Alin; Laude, Dominique; Elghozi, Jean-Luc; Sander, Denise; Agelink, Marcus W; Hilz, Max J; Ziegler, Dan

    2009-02-01

    Sildenafil, frequently used as on demand medication for the treatment of erectile dysfunction (ED), has been suggested to improve endothelial function but also to alter blood pressure (BP) and induce sympathetic activation. In people with type 2 diabetes mellitus (T2DM), a high-risk population, the safety profile and the effects on endothelial function of a maximal sildenafil dose (100 mg) have not been investigated and therefore constituted the aim of our study. A double-blind, placebo-controlled, cross-over trial using a single dose of 100 mg sildenafil or placebo has been conducted in 40 subjects with T2DM without known CVD. Haemodynamic parameters, flow mediated dilatation (FMD) in brachial artery, cardiovascular autonomic function tests and spontaneous baroreflex sensitivity (BRS) were measured. Sixty minutes after administration of sildenafil but not placebo, a fall of supine systolic blood pressure (SBP) (-5.41 +/- 1.87 vs. + 0.54 +/- 1.71 mmHg) and diastolic blood pressure (DBP) (-4.46 +/- 1.13 vs. + 0.89 +/- 0.94 mmHg), as well as orthostatic SBP (-7.41 +/- 2.35 vs. + 0.94 +/- 2.06 mmHg) and DBP (-5.65 +/- 1.45 vs. + 1.76 +/- 1.00 mmHg) during standing occurred, accompanied by an increase in heart rate (+1.98 +/- 0.69 vs. - 2.42 +/- 0.59 beats/min) (all p < 0.01 vs. placebo). Changes in BP to standing up, FMD, time domain and frequency domain indices of heart rate variability (HRV) and BRS were comparable between sildenafil and placebo. Sildenafil administered at a maximum single dose to T2DM men results in a mild increase in heart rate and decrease in BP, but it induces neither an acute improvement of FMD nor any adverse effects on orthostatic BP regulation, HRV and BRS. Copyright (c) 2008 John Wiley & Sons, Ltd.

  15. Patients with Obstructive Sleep Apnea Display Decreased Flow-Mediated Dilatation: Evidence from a Meta-Analysis

    PubMed Central

    Wang, Yuyu; Xu, Huajun; Qian, Yingjun; Guan, Jian; Yi, Hongliang; Yin, Shankai

    2017-01-01

    Background Endothelial dysfunction, which can be measured by flow-mediated dilatation (FMD), is an early clinical marker of atherosclerosis, which is considered to be the main cause of the observed cardiovascular complications in obstructive sleep apnea (OSA) patients. The association between OSA and endothelial dysfunction has been reported in a number of studies; however, the findings are not entirely consistent. Our aim was to meta-analytically synthesize the existing evidence to explore the association between OSA and endothelial dysfunction. Material/Methods Data from PubMed, EMBASE, the Cochrane library, and Google Scholar for all trials that investigated the relationship between endothelial dysfunction and OSA were systematically reviewed. The minimum inclusion criteria for the studies were reporting of the Apnea-Hypopnea Index (AHI) and FMD measurements (as an indicator of endothelial dysfunction) for both OSA and control groups. Data from case-control studies that met the inclusion criteria were extracted. Results Twenty-eight studies comprising a total of 1496 OSA patients and 1135 controls were included in the meta-analysis. A random-effects model was used. The weighted mean difference in the FMD measurements was −3.07 and the 95% confidence interval was −3.71 to −2.43 (P<0.01). Meta-regression analysis showed that age, sex, body mass index (BMI), blood pressure, glucose, high-density lipoprotein (HDL) cholesterol, and low-density lipoprotein (LDL) cholesterol did not explain the heterogeneity. Conclusions This meta-analysis showed that patients with OSA have decreased FMD, which may contribute to the development of atherosclerosis. PMID:28245208

  16. Impact of reduced daily physical activity on conduit artery flow-mediated dilation and circulating endothelial microparticles

    PubMed Central

    Boyle, Leryn J.; Credeur, Daniel P.; Jenkins, Nathan T.; Padilla, Jaume; Leidy, Heather J.; Thyfault, John P.

    2013-01-01

    Physical inactivity promotes the development of cardiovascular diseases. However, few data exist examining the vascular consequences of short-term reductions in daily physical activity. Thus we tested the hypothesis that popliteal and brachial artery flow-mediated dilation (FMD) would be reduced and concentrations of endothelial microparticles (EMPs) would be elevated following reduced daily physical activity. To examine this, popliteal and brachial artery FMD and plasma levels of EMPs suggestive of apoptotic and activated endothelial cells (CD31+/CD42b− and CD62E+ EMPs, respectively) were measured at baseline and during days 1, 3, and 5 of reduced daily physical activity in 11 recreationally active men (25 ± 2 yr). Subjects were instructed to reduce daily physical activity by taking <5,000 steps/day and refraining from planned exercise. Popliteal artery FMD decreased with reduced activity (baseline: 4.7 ± 0.98%, reduced activity day 5: 1.72 ± 0.68%, P < 0.05), whereas brachial artery FMD was unchanged. In contrast, baseline (pre-FMD) popliteal artery diameter did not change, whereas brachial artery diameter decreased (baseline: 4.35 ± 0.12, reduced activity day 5: 4.12 ± 0.11 P < 0.05) following 5 days of reduced daily physical activity. CD31+/CD42b− EMPs were significantly elevated with reduced activity (baseline: 17.6 ± 9.4, reduced activity day 5: 104.1 ± 43.1 per μl plasma, P < 0.05), whereas CD62E+ EMPs were unaltered. Collectively, our results provide evidence for the early and robust deleterious impact of reduced daily activity on vascular function and highlight the vulnerability of the vasculature to a sedentary lifestyle. PMID:24072406

  17. The combined influence of fat consumption and repeated mental stress on brachial artery flow-mediated dilatation: a preliminary study.

    PubMed

    Poitras, Veronica J; Slattery, David J; Levac, Brendan M; Fergus, Stevenson; Gurd, Brendon J; Pyke, Kyra E

    2014-04-01

    Experienced separately, both acute mental stress and high-fat meal consumption can transiently impair endothelial function, and the purpose of the present study was to investigate their combined impact. On four separate days, 10 healthy men (23 years old) underwent brachial artery flow-mediated dilatation (FMD) tests, before and hourly for 4 h post-consumption of a high-fat (HFM; 54 g fat) or low-fat meal (LFM; 0 g fat; each meal ∼ 1000 calories), with hourly mental stress (mental arithmetic, speech) or control (counting) tasks (conditions HFM+S, LFM+S, HFM and LFM). Data are presented as means ± SD. Plasma triglycerides increased and remained elevated after the high-fat but not the low-fat meal (P = 0.004) and were not affected by mental stress (P = 0.329). Indices of stress reactivity increased during mental stress tasks (mean arterial pressure, ∼ 20 mmHg; heart rate, ∼ 22 beats min(-1); salivary cortisol, ∼ 2.37 nmol l(-1); and plasma noradrenaline, ∼ 0.17 ng ml(-1)) and were not influenced by meal (P > 0.05). There was no effect of the type of meal on FMD (P = 0.562); however, FMD was 4.5 ± 0.5% in the control conditions and 5.8 ± 0.6% in the mental stress conditions (P = 0.087), and this difference was significant when normalized for the shear stress stimulus (FMD/area under the curve of shear stress, P = 0.045). Overall, these preliminary data suggest that postprandial FMD was augmented with mental stress irrespective of meal type. These results are contrary to previous reports of impaired endothelial function after mental stress or fat consumption independently and highlight the need to further investigate the mechanisms underlying the interactions between these factors.

  18. Targeting inflammation using salsalate in patients with type 2 diabetes: effects on flow-mediated dilation (TINSAL-FMD).

    PubMed

    Goldfine, Allison B; Buck, J Stewart; Desouza, Cyrus; Fonseca, Vivian; Chen, Yii-Der Ida; Shoelson, Steven E; Jablonski, Kathleen A; Creager, Mark A

    2013-12-01

    To test whether inhibiting inflammation with salsalate improves endothelial function in patients with type 2 diabetes (T2D). We conducted an ancillary study to the National Institutes of Health-sponsored, multicenter, randomized, double-masked, placebo-controlled trial evaluating the safety and efficacy of salsalate in targeting inflammation to improve glycemia in patients with T2D. Flow-mediated, endothelium-dependent dilation (FMD) and endothelium-independent, nitroglycerin-mediated dilation (NMD) of the brachial artery were assessed at baseline and 3 and 6 months following randomization to either salsalate 3.5 g/day or placebo. The primary end point was change in FMD at 6 months. A total of 88 participants were enrolled in the study, and data after randomization were available for 75. Patients in the treatment and control groups had similar ages (56 years), BMI (33 kg/m(2)), sex (64% male), ethnicity, current treatment, and baseline HbA1c (7.7% [61 mmol/mol]). In patients treated with salsalate versus placebo, HbA1c was reduced by 0.46% (5.0 mmol/mol; P < 0.001), fasting glucose by 16.1 mg/dL (P < 0.001), and white blood cell count by 430 cells/µL (P < 0.02). There was no difference in the mean change in either FMD (0.70% [95% CI -0.86 to 2.25%]; P = 0.38) or NMD (-0.59% [95% CI -2.70 to 1.51%]; P = 0.57) between the groups treated with salsalate and placebo at 6 months. Total and LDL cholesterol were 11 and 16 mg/dL higher, respectively, and urinary albumin was 2.0 µg/mg creatinine higher in the patients treated with salsalate compared with those treated with placebo (all P < 0.009). Salsalate does not change FMD in peripheral conduit arteries in patients with T2D despite lowering HbA1c. This finding suggests that salsalate does not have an effect on vascular inflammation, inflammation does not cause endothelial dysfunction in T2D, or confounding effects of salsalate mitigate favorable effects on endothelial function.

  19. Effect of reactive hyperemia on carotid-radial pulse wave velocity in hypertensive participants and direct comparison with flow-mediated dilation: a pilot study.

    PubMed

    Kamran, Haroon; Salciccioli, Louis; Ko, Eun Hee; Qureshi, Ghazanfar; Kazmi, Haris; Kassotis, John; Lazar, Jason

    2010-01-01

    This pilot study assessed the effects of hyperemia on carotid-radial pulse wave velocity (PWV) in 39 normotensive (NT) and 23 hypertensive (HT) participants using applanation tonometry. Pulse wave velocity was measured at 1- and at 2-minute intervals. Baseline PWV was similar between the groups (P = .59). At 1 minute, PWV decreased (8.5 +/- 1.2 to 7.1 +/- 1.4 m/s, P < .001) in NT but not in HT (P = .83). Hyperemic PWV (DeltaPWV) response differed between the groups (-16% vs + 1.0%, P < .001). On multivariate analysis, HT, not age or blood pressure was independently related to DeltaPWV (R(2) = .43, P < .01). Among patients with cardiovascular risk factors/disease, DeltaPWV was inversely related to flow-mediated dilation (FMD; R( 2) = .43, P < .003). hyperemia decreases PWV(1min) in NT but not in HT. DeltaPWV is inversely related to FMD. Blunted hyperemic PWV response may represent impaired vasodilatory reserve.

  20. Effect of cocoa/chocolate ingestion on brachial artery flow-mediated dilation and its relevance to cardiovascular health and disease in humans.

    PubMed

    Monahan, Kevin D

    2012-11-15

    Prospective studies indicate that high intake of dietary flavanols, such as those contained in cocoa/chocolate, are associated with reduced rates of cardiovascular-related morbidity and mortality in humans. Numerous mechanisms may underlie these associations such as favorable effects of flavanols on blood pressure, platelet aggregation, thrombosis, inflammation, and the vascular endothelium. The brachial artery flow-mediated dilation (FMD) technique has emerged as a robust method to quantify endothelial function in humans. Collectively, the preponderance of evidence indicates that FMD is a powerful surrogate measure for firm cardiovascular endpoints, such as cardiovascular-related mortality, in humans. Thus, literally thousands of studies have utilized this technique to document group differences in FMD, as well as to assess the effects of various interventions on FMD. In regards to the latter, numerous studies indicate that both acute and chronic ingestion of cocoa/chocolate increases FMD in humans. Increases in FMD after cocoa/chocolate ingestion appear to be dose-dependent such that greater increases in FMD are observed after ingestion of larger quantities. The mechanisms underlying these responses are likely diverse, however most data suggest an effect of increased nitric oxide bioavailability. Thus, positive vascular effects of cocoa/chocolate on the endothelium may underlie (i.e., be linked mechanistically to) reductions in cardiovascular risk in humans.

  1. Vitamin D3 supplementation for 16 weeks improves flow-mediated dilation in overweight African American adults

    PubMed Central

    Harris, Ryan A; Pedersen-White, Jennifer; Guo, De-Huang; Stallmann-Jorgensen, Inger S.; Keeton, Daniel; Huang, Ying; Shah, Yashesh; Zhu, Haidong; Dong, Yanbin

    2013-01-01

    Background A growing body of evidence has linked vitamin D deficiency to increased risk of cardiovascular disease. Vitamin D deficiency is also more common in African Americans for whom an increased cardiovascular disease risk exists. This study sought to test the hypothesis that 16 weeks of 60,000 IU monthly supplementation of oral vitamin D3 would improve flow-mediated dilation (FMD) in African Americans, whereas no change would be observed in the placebo group. Methods A randomized, double blind, placebo controlled clinical trial was conducted. Fifty-seven African American adults were randomly assigned to either the placebo group or vitamin D group. Results Following 16 weeks of placebo (n=23; mean age 31±2 years) or 60,000 IU monthly oral vitamin D3 (n=22; mean age 29±2 years), serum concentrations of 25 hydroxyvitamin D increased from 38.2±3.0 nmol/L to 48.7±3.2 nmol/L and 34.3±2.2 nmol/L to 100.9±6.6 nmol/L, respectively. No changes in serum parathyroid hormone, serum calcium, or urine calcium/creatinine were observed following either treatment. Following 16 weeks of treatment, significant improvements in FMD were only observed in the vitamin D group (1.8±1.3%), whereas the placebo group had no change (-1.3±0.6%). Similarly, the vitamin D group exhibited an increase in absolute change in diameter (0.005±0.004 cm) and FMD/shear (0.08±0.04 %/s-1, AUC × 103) following treatment, whereas no change (-0.005±0.002 cm and -0.02±0.02 %/s-1, AUC, respectively) was observed following placebo. Conclusions Supplementation of 60,000 IU monthly oral vitamin D3 (~2000 IU per day) for 16 weeks is effective at improving vascular endothelial function in African American adults. PMID:21311504

  2. Carotid intima-media thickness and flow-mediated dilation in obese children with non-alcoholic fatty liver disease.

    PubMed

    Torun, Emel; Aydın, Sinem; Gökçe, Selim; Özgen, İlker Tolga; Donmez, Tuğrul; Cesur, Yaşar

    2014-12-01

    This study aimed to understand the role of non-alcoholic fatty liver disease (NAFLD) in increasing the risk of atherosclerosis in obese pediatric patients. The study included 109 obese children (age, 9-15 years) and a control group comprising 44 healthy age- and gender-matched children with normal weight. NAFLD was diagnosed using conventional ultrasound (US) examination. Both right carotid intima-media thickness (CIMT) and flow-mediated dilation (FMD) were assessed in addition to anthropometric measures and serum biochemical parameters, including lipid profile and fasting glucose and insulin levels. Homeostatic model assessment of insulin resistance (HOMA-IR) was calculated as a measure of insulin resistance. Mean age and gender distributions were similar in the obese children and control group (p=0.168 and p=0.705, respectively). Median body mass index standard deviation scores of obese children with grade II-III NAFLD were significantly higher than those of obese children without hepatosteatosis (p<0.001). Median total cholesterol levels were similar in all the groups (p=0.263). Low-density lipoprotein cholesterol and triglyceride levels increased and high-density lipoprotein cholesterol levels decreased significantly as the grade of steatosis increased (p<0.001, p<0.05, and p=0.05, respectively). Median alanine aminotransaminase (ALT) and HOMA-IR levels of obese children with grade II-III NAFLD were significantly higher than those of obese children without NAFLD (p=0.01) and obese children with grade I NAFLD (p=0.001). CIMT was significantly correlated with the grade of steatosis (p<0.001) and level of ALT (p=0.005). Linear regression analysis showed that the grade of hepatosteatosis had a significant effect on CIMT. FMD decreased as the grade of hepatosteatosis increased, but it did not reach a significant level. The obese children with hepatosteatosis showed increased CIMT, as indicated by the grade of steatosis, compared with healthy controls and obese

  3. Inorganic nitrate ingestion improves vascular compliance but does not alter flow-mediated dilatation in healthy volunteers.

    PubMed

    Bahra, M; Kapil, V; Pearl, V; Ghosh, S; Ahluwalia, A

    2012-05-15

    Ingestion of inorganic nitrate elevates blood and tissue levels of nitrite via bioconversion in the entero-salivary circulation. Nitrite is converted to NO in the circulation, and it is this phenomenon that is thought to underlie the beneficial effects of inorganic nitrate in humans. Our previous studies have demonstrated that oral ingestion of inorganic nitrate decreases blood pressure and inhibits the transient endothelial dysfunction caused by ischaemia-reperfusion injury in healthy volunteers. However, whether inorganic nitrate might improve endothelial function per se in the absence of a pathogenic stimulus and whether this might contribute to the blood pressure lowering effects is yet unknown. We conducted a randomised, double-blind, crossover study in 14 healthy volunteers to determine the effects of oral inorganic nitrate (8 mmol KNO(3)) vs. placebo (8 mmol KCl) on endothelial function, measured by flow-mediated dilatation (FMD) of the brachial artery, prior to and 3h following capsule ingestion. In addition, blood pressure (BP) was measured and aortic pulse wave velocity (aPWV) determined. Finally, blood, saliva and urine samples were collected for chemiluminescence analysis of [nitrite] and [nitrate] prior to and 3h following interventions. Inorganic nitrate supplementation had no effect on endothelial function in healthy volunteers (6.9±1.1% pre- to 7.1±1.1% post-KNO(3)). Despite this, there was a significant elevation of plasma [nitrite] (0.4±0.1 μM pre- to 0.7±0.2 μM post-KNO(3), p<0.001). In addition these changes in [nitrite] were associated with a decrease in systolic BP (116.9±3.8mm Hg pre- vs. 112.1±3.4 mm Hg post-KNO(3), p<0.05) and aPWV (6.5±0.1 m/s pre- to 6.2±0.1 post-KNO(3), p<0.01). In contrast KCl capsules had no effect on any of the parameters measured. These findings demonstrate that although inorganic nitrate ingestion does not alter endothelial function per se, it does appear to improve blood flow, in combination with a

  4. The Effect of Cilostazol on Endothelial Function as Assessed by Flow-Mediated Dilation in Patients with Coronary Artery Disease

    PubMed Central

    Mori, Hiroyoshi; Maeda, Atsuo; Wakabayashi, Kohei; Sato, Tokutada; Sasai, Masahiro; Tashiro, Kazuma; Iso, Yoshitaka; Ebato, Mio

    2016-01-01

    Aim: The vascular endothelium plays a key role in the pathophysiology of atherosclerosis. Flow-mediated dilation (FMD) is a novel way of assessing endothelial function. Cilostazol is a unique antiplatelet drug that also has the potential to improve endothelial function. The objective of this present study was to investigate the effects of cilosatzol on endothelial function as assessed by FMD. Methods: Fifty-one patients with coronary artery disease (CAD) were assigned to one of two groups: the Cilostazol(+) group (with cilostazol) and Cilostazol(−) group (without cilostazol). In addition to conventional dual antiplatelet therapy with aspirin and clopidogrel/ticlopidine, the Cilostazol(+) group (n = 27) was also given cilostazol (100 mg/day). The Cilostazol(−) group (n = 24) did not receive cilostazol. FMD was assessed at enrollment and after 6–9 months. Results: The FMD of both the Cilostazol(+) and Cilostazol(−) groups remained similar at 5.2 (interquartile range: 3.8–8.5) to 5.4 (interquartile range: 4.2–6.7) (P = 0.29) and 5.0 (interquartile range: 3.6–6.4) to 4.9 (interquartile range: 4.0–7.0) (P = 0.38), respectively. However, the diameters of the baseline and maximal brachial arteries tended to increase in the Cilostazol(−) group (baseline: 4.2 ± 0.7 to 4.4 ± 0.7, P = 0.18; maximal: 4.5 ± 0.7 to 4.6 ± 0.7 P = 0.22), whereas that of the Cilostazol(−) group tended to decrease (baseline: 4.1 ± 0.6 to 3.9 ± 0.5, P = 0.10; maximal: 4.3 ± 0.7 to 4.1 ± 0.5, P = 0.05). The rates of change in the baseline diameter (Cilostazol(+): 3.7 ± 9.8% vs. Cilostazol(−): −3.8 ± 12.2%, P = 0.03) and maximal diameter (Cilostazol(+): +3.1 ± 8.9% vs. Cilostazol(−): −4.4 ± 12.0%, P = 0.02) were significantly different. Conclusion: Although cilostazol didn't affect the FMD, there was a significant difference in the rates of change in baseline and maximal brachial artery diameter. This may have a beneficial effect in patients with cardiovascular

  5. [Brachial artery flow-mediated dilation in healthy men, men with risk factors, and men with acute myocardial infarction. Importance of occlusion-cuff position].

    PubMed

    Dalli, Ernesto; Segarra, Leopoldo; Ruvira, Jorge; Esteban, Esther; Cabrera, Abraham; Lliso, Ramón; López, Esther; Llopis, Enric; Sotillo, José F

    2002-09-01

    Flow-mediated dilation (FMD) is endothelium-dependent and can be assessed by ultrasound in the brachial artery. We sought to determine the most suitable position for the occlusion cuff for the study of FMD in three groups of adult men. We included 160 subjects, mean age 58.5 7.8 years: 40 healthy subjects, 80 with cardiovascular risk factors, and 40 patients with AMI. In a subgroup of 60 subjects, the first 10, 30, and 20 of each group, respectively, FMD was evaluated twice, after upper arm occlusion and forearm occlusion to induce hyperemia. In the initial substudy, the FMD after upper arm occlusion was 7.6 2.4% in healthy subjects, 5.1 2.2% in men with risk factors (p < 0.0001), and 3.5 2.2% in AMI patients (p < 0.041, with respect to the risk-factor group). FMD after forearm occlusion was 4.6 1.5%, 2.3 2.1% (p < 0.006), and 2.2 1.9%, respectively, with no significant statistical differences between the risk-factor and AMI groups. Only upper arm occlusion was performed in the remaining participants, as planned, because it provided the most accurate information. Overall, the FMD was, respectively, 7.8 3.1%, 5 2.6% (p < 0.0001) and 3.3 3% (p < 0.004, with respect to the risk-factor group). FMD was directly related to HDL cholesterol and inversely related to resting diameter and number of risk factors. The best approach to studying FMD is proximal occlusion since it allows for a better stratification of the with endothelial dysfunction. With this technique, a worsening of endothelial function in acute myocardial infarction can be demonstrated.

  6. Serum amyloid P (SAP) is associated with impaired brachial artery flow-mediated dilation in chronically HIV-1 infected adults on stable antiretroviral therapy.

    PubMed

    Zungsontiporn, Nath; Ndhlovu, Lishomwa C; Mitchell, Brooks I; Stein, James H; Kallianpur, Kalpana J; Nakamoto, Beau; Keating, Sheila M; Norris, Philip J; Souza, Scott A; Shikuma, Cecilia M; Chow, Dominic C

    2015-11-01

    This study aimed to evaluate the relationship between inflammatory biomarkers and endothelial dysfunction (ED), as measured by brachial artery flow-mediated dilation (FMD). We conducted a cross-sectional analysis utilizing baseline data of 135 participants with HIV infection on stable antiretroviral therapy (ART) in the Hawaii Aging with HIV-Cardiovascular (HAHC-CVD) study who had available baseline inflammatory biomarkers and brachial artery FMD measurements. We observed significant associations between brachial artery FMD and baseline brachial artery diameter, age, male gender, traditional cardiovascular disease (CVD) risk factors such as BMI, waist to hip ratio, hypertension, systolic blood pressure (BP), diastolic BP, and LDL cholesterol, and 10-year coronary heart disease (CHD) risk estimated by Framingham risk score (FRS). Of all biomarkers tested, higher level of C-reactive protein (CRP) (beta =  - 0.695, P = 0.030) and serum amyloid P (SAP) (beta =  - 1.318, P = 0.021) were significantly associated with lower brachial artery FMD in univariable regression analysis. After adjusting for baseline brachial artery diameter, age, and selected traditional CVD risk factors in multivariable model, SAP remained significantly associated with brachial artery FMD (beta =  - 1.094, P = 0.030), while CRP was not (beta =  - 0.391, P = 0.181). Serum amyloid P was independently associated with impaired brachial artery FMD and may potentially relate to ED and increased CVD risk in HIV-infected patients on stable ART.

  7. Flow-mediated dilatation (FMD) and prevalence of cardiovascular risk factors: the value of FMD assessment in high risk patients is limited.

    PubMed

    Mizia-Stec, Katarzyna; Wieczorek, Joanna; Orszulak, Michał; Mizia, Magdalena; Gieszczyk-Strózik, Klaudia; Sikora-Puz, Agnieszka; Haberka, Maciej; Lasota, Bartosz; Chmiel, Artur

    2014-01-01

    Since flow-mediated dilatation (FMD) is influenced by different factors, its clinical usefulness and validation is widely discussed. To assess the major factors that determine FMD values in a wide range of subjects with and without cardiovascular (CV) risk factors/diseases (CVRF/CVD). 617 consecutive patients (mean age: 50.1 ± 14.9 years, males: 349/56.5%) hospitalised between 2005 and 2011 were enrolled into the study. Demographic data and CVRF/CVD with a significant impact on FMD values were analysed: hyperlipidaemia, active smoking, arterial hypertension, coronary artery disease, diabetes mellitus and heart valve disease. The population was divided depending on the number of coexisting CVRF/CVD (0-, 1-, 2-, 3-, 4-, 5-CVRF/CVD groups). The median FMD value in the entire group of patients was 10% (5-17). An analysis of the FMD percentage in particular groups showed significantly higher FMD values in patients without any CVRF/CVD (group 0), as well as in patients with one coexisting CVRF/CVD (group 1) compared to the other groups. The presence of two or more CVRF/CVD was not associated with a significantly higher FMD reduction. The analysis of patients with only one CVRF/CVD revealed the lowest FMD values in patients with coronary artery disease. FMD is related to the number of traditional CVRF/CVDs; however, coronary artery disease has the most significant influence on FMD decrease among analysed factors. The value of FMD assessment in high risk patients is limited.

  8. Assessment of endothelial dysfunction by flow-mediated dilatation in men on long-term androgen deprivation therapy for prostate cancer.

    PubMed

    Gilbert, Stephen E; Tew, Garry A; Bourke, Liam; Winter, Edward M; Rosario, Derek J

    2013-09-01

    What is the central question of this study? Androgen deprivation therapy (ADT) for prostate cancer has been linked with increased cardiovascular risk, but the mechanisms are unclear. Is there evidence that endothelial dysfunction, as evidenced by reduced flow-mediated dilatation (FMD), is associated with ADT? What is the main finding and its importance? Reduction in FMD with preservation of glyceryl trinitrate-mediated dilatation indicates endothelial dysfunction in men with prostate cancer on long-term ADT compared with well-matched control subjects. Vascular endothelial dysfunction associated with long-term ADT for prostate cancer might explain the observed epidemiological increases in adverse cardiovascular events. Assessment of FMD may be useful in the monitoring of cardiovascular risk in men with prostate cancer on ADT. Androgen deprivation therapy (ADT) in men with prostate cancer has been linked to an increased incidence of cardiovascular events and mortality, but the underpinning mechanisms are unclear. Endothelial dysfunction is considered a precursor for cardiovascular disease. Previous studies have reported variably on the association between ADT and endothelial function. This blinded case-control study examined endothelial function, using high-resolution ultrasound to measure flow-mediated dilatation (FMD) and glyceryl trinitrate (GTN)-mediated-dilatation in the brachial artery, in 20 men with prostate cancer (69 ± 7 years old) treated by ADT (median duration 22 months, range 6-133 months) and 20 men without prostate cancer (69 ± 5 years old) matched for age, physical activity, coexistent cardiovascular disease and body mass index. The magnitude of dilatation was calculated traditionally and allometrically scaled, adjusting for baseline diameter. There were no differences between groups for resting vascular measures (means ± SD). Flow-mediated dilatation was lower in men on ADT than in control subjects (3.9 ± 2.1 versus 5.9 ± 3.8% for traditional

  9. Exenatide improves endothelial function assessed by flow mediated dilation technique in subjects with type 2 diabetes: results from an observational research.

    PubMed

    Irace, Concetta; De Luca, Simona; Shehaj, Ermal; Carallo, Claudio; Loprete, Antonio; Scavelli, Faustina; Gnasso, Agostino

    2013-01-01

    The GLP-1 receptor agonist exenatide has been approved for adjunctive treatment of type 2 diabetes. Continuous GLP-1 infusion improves endothelial function in vivo; no evidence about a beneficial effect of exenatide on vascular function has been published. The aim of our observational study was to evaluate whether exenatide would improve brachial artery function evaluated by the flow mediated dilation (FMD) technique, compared with glimepiride, in subjects with type 2 diabetes. FMD time course was assessed by ultrasound, after 5 min forearm ischaemia, at baseline and after 16-week treatment. At the end of the study FMD was significantly higher in subjects who assumed exenatide compared with glimepiride (9.1 ± 3.6 vs. 5.6 ± 1.0, p = 0.01). Even if limited by the small number of studied subjects, who were not matched in the two treatment groups, this research study represents the first FMD evidence suggesting that chronic administration of exenatide improves arterial dilation.

  10. The effect of α1 -adrenergic blockade on post-exercise brachial artery flow-mediated dilatation at sea level and high altitude.

    PubMed

    Tymko, Michael M; Tremblay, Joshua C; Hansen, Alex B; Howe, Connor A; Willie, Chris K; Stembridge, Mike; Green, Daniel J; Hoiland, Ryan L; Subedi, Prajan; Anholm, James D; Ainslie, Philip N

    2017-03-01

    Our objective was to quantify endothelial function (via brachial artery flow-mediated dilatation) at sea level (344 m) and high altitude (3800 m) at rest and following both maximal exercise and 30 min of moderate-intensity cycling exercise with and without administration of an α1 -adrenergic blockade. Brachial endothelial function did not differ between sea level and high altitude at rest, nor following maximal exercise. At sea level, endothelial function decreased following 30 min of moderate-intensity exercise, and this decrease was abolished with α1 -adrenergic blockade. At high altitude, endothelial function did not decrease immediately after 30 min of moderate-intensity exercise, and administration of α1 -adrenergic blockade resulted in an increase in flow-mediated dilatation. Our data indicate that post-exercise endothelial function is modified at high altitude (i.e. prolonged hypoxaemia). The current study helps to elucidate the physiological mechanisms associated with high-altitude acclimatization, and provides insight into the relationship between sympathetic nervous activity and vascular endothelial function. We examined the hypotheses that (1) at rest, endothelial function would be impaired at high altitude compared to sea level, (2) endothelial function would be reduced to a greater extent at sea level compared to high altitude after maximal exercise, and (3) reductions in endothelial function following moderate-intensity exercise at both sea level and high altitude are mediated via an α1 -adrenergic pathway. In a double-blinded, counterbalanced, randomized and placebo-controlled design, nine healthy participants performed a maximal-exercise test, and two 30 min sessions of semi-recumbent cycling exercise at 50% peak output following either placebo or α1 -adrenergic blockade (prazosin; 0.05 mg kg( -1) ). These experiments were completed at both sea-level (344 m) and high altitude (3800 m). Blood pressure (finger photoplethysmography

  11. Omega-3 fatty acid therapy dose-dependently and significantly decreased triglycerides and improved flow-mediated dilation, however, did not significantly improve insulin sensitivity in patients with hypertriglyceridemia.

    PubMed

    Oh, Pyung Chun; Koh, Kwang Kon; Sakuma, Ichiro; Lim, Soo; Lee, Yonghee; Lee, Seungik; Lee, Kyounghoon; Han, Seung Hwan; Shin, Eak Kyun

    2014-10-20

    Experimental studies demonstrate that higher intake of omega-3 fatty acids (n-3 FA) improves insulin sensitivity, however, we reported that n-3 FA 2g therapy, most commonly used dosage did not significantly improve insulin sensitivity despite reducing triglycerides by 21% in patients. Therefore, we investigated the effects of different dosages of n-3 FA in patients with hypertriglyceridemia. This was a randomized, single-blind, placebo-controlled, parallel study. Age, sex, and body mass index were matched among groups. All patients were recommended to maintain a low fat diet. Forty-four patients (about 18 had metabolic syndrome/type 2 diabetes mellitus) in each group were given placebo, n-3 FA 1 (O1), 2 (O2), or 4 g (O4), respectively daily for 2 months. n-3 FA therapy dose-dependently and significantly decreased triglycerides and triglycerides/HDL cholesterol and improved flow-mediated dilation, compared with placebo (by ANOVA). However, each n-3 FA therapy did not significantly decrease high-sensitivity C-reactive protein and fibrinogen, compared with placebo. O1 significantly increased insulin levels and decreased insulin sensitivity (determined by QUICKI) and O2 significantly decreased plasma adiponectin levels relative to baseline measurements. Of note, when compared with placebo, each n-3 FA therapy did not significantly change insulin, glucose, adiponectin, glycated hemoglobin levels and insulin sensitivity (by ANOVA). We observed similar results in a subgroup of patients with the metabolic syndrome. n-3 FA therapy dose-dependently and significantly decreased triglycerides and improved flow-mediated dilation. Nonetheless, n-3 FA therapy did not significantly improve acute-phase reactants and insulin sensitivity in patients with hypertriglyceridemia, regardless of dosages. Copyright © 2014. Published by Elsevier Ireland Ltd.

  12. High-frequency ultrasonographic imaging of the endothelium-dependent flow-mediated dilatation (FMD) in a brachial artery: normative ranges in a group of low CV risk subjects of different ages.

    PubMed

    Ryliskyte, Ligita; Ghiadoni, Lorenzo; Plantinga, Yvonne; Janaviciene, Silvija; Petrulioniene, Zaneta; Laucevicius, Aleksandras; Gintautas, Jonas

    2004-01-01

    High-frequency ultrasonographic imaging of flow-mediated dilatation (FMD) in a brachial artery, as non-invasive technique, was used for the clinical evaluation of endothelial function (EF) in 115 subjects (ages 44.19+/-12.23 (26 to 83) free of coronary heart disease or its equivalents. Our aim was to study the normative ranges for FMD in subjects of different age groups with low cardiovascular risk factors. The mean FMD was 8.23+/-4.51% (0 to 20.9). Multivariate analysis revealed that there were only two independent predictors of FMD: resting vessel diameter (r = -0.45, p<0.0001) and age (r = -0.55, p<0.0001). The multiple regression equation for this data was FMD = 25.5-0.17 x age-2.6 x resting vessel diameter. Our study demonstrates that FMD in low cardiovascular risk patients inversely correlates with age as well as brachial artery diameter. Normative ranges of FMD could be predicted for different age groups. In addition to conventional methods for the assessment of cardiovascular risk by using a population-based approach (score indexes such as SCORE, FRAMINGH, PROCAM), high-frequency ultrasonographic imaging of flow-mediated dilatation (FMD) in the brachial artery is now becoming an accepted method for the assessment of an individual patient's cardiovascular risk. Although preliminary guidelines have been published, this technique has interpretive limitations. In a study that was published earlier, the authors estimated diameter-related normal ranges of FMD. Several articles reported cut points between control and diseased groups. Data about the impact of age on FMD are also available in the literature. However, this is the first attempt to classify normal values into groups according to age and diameter.

  13. Sex Specific Effects of Habitual Aerobic Exercise on Brachial Artery Flow-Mediated Dilation in Middle-Aged and Older Adults

    PubMed Central

    Pierce, Gary L.; Eskurza, Iratxe; Walker, Ashley E.; Fay, Tara N.; Seals, Douglas R.

    2013-01-01

    Brachial artery flow-mediated dilation (FMD) is impaired with aging and is associated with increased risk for cardiovascular disease (CVD). We determined if regular aerobic exercise improves brachial artery FMD in middle-aged/older (MA/O) men and postmenopausal women. In sedentary MA/O adults (age 55 – 79 years) without CVD, 8 weeks of brisk walking (6 days/week for ~50 min/day; randomized, controlled design) increased treadmill time ~20% in both MA/O men (n=11) and postmenopausal women (n=15) (P<0.01), without altering body composition or circulating CVD risk factors. Brachial artery FMD increased > 50% in the MA/O men (4.6 ± 0.6 to 7.1 ± 0.6%, P < 0.01), but did not change in the postmenopausal women (5.1 ± 0.8 vs. 5.4 ± 0.7%, P = 0.50). No changes occurred in the non-exercising controls. In a separate cross-sectional study (n =167), brachial artery FMD was ~50% greater in endurance exercise-trained (6.4 ± 0.4%, n = 45) vs. sedentary (4.3 ± 0.3%, n = 60) MA/O men (P < 0.001), whereas there were no differences between endurance-trained (5.3 ± 0.7%, n = 20) and sedentary (5.6 ± 0.5%, n = 42) postmenopausal women (P = 0.70). Brachial artery lumen diameter, peak hyperemic shear rate and endothelium independent dilation did not differ with exercise intervention or in the endurance-exercise vs. sedentary groups. Regular aerobic exercise is consistently associated with enhanced brachial artery FMD in MA/O men, but not in postmenopausal women. Some postmenopausal women without CVD may be less responsive to habitual aerobic exercise than MA/O men. PMID:20642454

  14. Black Tea Increases Circulating Endothelial Progenitor Cells and Improves Flow Mediated Dilatation Counteracting Deleterious Effects from a Fat Load in Hypertensive Patients: A Randomized Controlled Study

    PubMed Central

    Grassi, Davide; Draijer, Richard; Schalkwijk, Casper; Desideri, Giovambattista; D’Angeli, Anatolia; Francavilla, Sandro; Mulder, Theo; Ferri, Claudio

    2016-01-01

    (1) Background: Endothelial dysfunction predicts cardiovascular events. Circulating angiogenic cells (CACs) maintain and repair the endothelium regulating its function. Tea flavonoids reduce cardiovascular risk. We investigated the effects of black tea on the number of CACs and on flow-mediated dilation (FMD) before and after an oral fat in hypertensives; (2) Methods: In a randomized, double-blind, controlled, cross-over study, 19 patients were assigned to black tea (150 mg polyphenols) or a placebo twice a day for eight days. Measurements were obtained in a fasted state and after consuming whipping cream, and FMD was measured at baseline and after consumption of the products; (3) Results: Compared with the placebo, black tea ingestion increased functionally active CACs (36 ± 22 vs. 56 ± 21 cells per high-power field; p = 0.006) and FMD (5.0% ± 0.3% vs. 6.6% ± 0.3%, p < 0.0001). Tea further increased FMD 1, 2, 3, and 4 h after consumption, with maximal response 2 h after intake (p < 0.0001). Fat challenge decreased FMD, while tea consumption counteracted FMD impairment (p < 0.0001); (4) Conclusions: We demonstrated the vascular protective properties of black tea by increasing the number of CACs and preventing endothelial dysfunction induced by acute oral fat load in hypertensive patients. Considering that tea is the most consumed beverage after water, our findings are of clinical relevance and interest. PMID:27854314

  15. Black Tea Increases Circulating Endothelial Progenitor Cells and Improves Flow Mediated Dilatation Counteracting Deleterious Effects from a Fat Load in Hypertensive Patients: A Randomized Controlled Study.

    PubMed

    Grassi, Davide; Draijer, Richard; Schalkwijk, Casper; Desideri, Giovambattista; D'Angeli, Anatolia; Francavilla, Sandro; Mulder, Theo; Ferri, Claudio

    2016-11-16

    (1) Background: Endothelial dysfunction predicts cardiovascular events. Circulating angiogenic cells (CACs) maintain and repair the endothelium regulating its function. Tea flavonoids reduce cardiovascular risk. We investigated the effects of black tea on the number of CACs and on flow-mediated dilation (FMD) before and after an oral fat in hypertensives; (2) Methods: In a randomized, double-blind, controlled, cross-over study, 19 patients were assigned to black tea (150 mg polyphenols) or a placebo twice a day for eight days. Measurements were obtained in a fasted state and after consuming whipping cream, and FMD was measured at baseline and after consumption of the products; (3) Results: Compared with the placebo, black tea ingestion increased functionally active CACs (36 ± 22 vs. 56 ± 21 cells per high-power field; p = 0.006) and FMD (5.0% ± 0.3% vs. 6.6% ± 0.3%, p < 0.0001). Tea further increased FMD 1, 2, 3, and 4 h after consumption, with maximal response 2 h after intake (p < 0.0001). Fat challenge decreased FMD, while tea consumption counteracted FMD impairment (p < 0.0001); (4) Conclusions: We demonstrated the vascular protective properties of black tea by increasing the number of CACs and preventing endothelial dysfunction induced by acute oral fat load in hypertensive patients. Considering that tea is the most consumed beverage after water, our findings are of clinical relevance and interest.

  16. A controlled comparison of brachial artery flow mediated dilation (FMD) and digital pulse amplitude tonometry (PAT) in the assessment of endothelial function in systemic lupus erythematosus.

    PubMed

    Aizer, J; Karlson, E W; Chibnik, L B; Costenbader, K H; Post, D; Liang, M H; Gall, V; Gerhard-Herman, M D

    2009-03-01

    The utility of flow mediated dilation (FMD) a measure of endothelial function is limited by operator dependence. Pulse amplitude tonometry (PAT) is a novel, less operator-dependent technique to assess endothelial function. This study compares PAT to FMD in SLE and controls. Thirty women with SLE and 31 controls were enrolled. Medications, cardiovascular disease and risk factors, SLE activity (SLAM-R) and damage (SLICC-DI) were recorded. FMD and PAT were performed simultaneously. Endothelium-independent function was assessed with nitroglycerin. Average age was 48.3 +/- 10.1 years, SLE duration 16.2 years, SLAM-R 8.3 and SLICC-DI 1.0. Framingham Risk Scores were < or =2% in most subjects. There were no differences between SLE cases and controls in FMD, PAT or response to nitroglycerin. This study found no association between FMD and PAT in SLE or controls. In the 17 SLE cases with a history of Raynaud's, correlation between FMD and PAT was 0.50 (P = 0.04). There was no difference in endothelial function assessed by FMD or PAT in SLE cases versus controls. FMD did not correlate with PAT except in SLE cases with a history of Raynaud's. Correlation between FMD and PAT may be stronger in populations with greater variation in endothelial function and more cardiovascular risk factors.

  17. Improvement in Accuracy of Ultrasonic Measurement of Transient Change in Viscoelasticity of Radial Arterial Wall Due to Flow-Mediated Dilation by Adaptive Low-Pass Filtering

    NASA Astrophysics Data System (ADS)

    Ikeshita, Kazuki; Hasegawa, Hideyuki; Kanai, Hiroshi

    2012-07-01

    In our previous study, the stress-strain relationship of the radial arterial wall was measured and the viscoelasticity of the intima-media region was estimated from the stress-strain relationship. Furthermore, the transient change in viscoelasticity due to flow-mediated dilation (FMD) was estimated by the automated detection of wall boundaries. In the present study, the strain rate was adaptively filtered to improve the accuracy of viscoelasticity estimation by decreasing the high-frequency noise. Additionally, in a basic experiment, this method was validated using a silicone tube (simulating artery). In the basic experiment, the elasticity was estimated with a mean error of 1.2%. The elasticity measured at each beam position was highly reproducible among measurements, whereas there was a slight variation in measured elasticity among beams. Consequently, in in vivo measurements, the normalized mean square error (MSE) was clearly decreased. Additionally, the stress-strain relationship of the radial arterial wall was obtained and the viscoelasticity was estimated accurately. The inner small loop, which corresponds to the negative pressure wave caused by the closure of the aortic valve, can be observed using the adaptive low-pass filtering (LPF). Moreover, the transient changes in these parameters were similar to those in the previous study. These results show the potential of the proposed method for the thorough analysis of the transient change in viscoelasticity due to FMD.

  18. Relationship Between Brachial Artery Flow-Mediated Dilation, Carotid Artery Intima-Media Thickness and Coronary Flow Reserve in Patients With Coronary Artery Disease

    PubMed Central

    Oz, Fahrettin; Elitok, Ali; Bilge, Ahmet Kaya; Mercanoglu, Fehmi; Oflaz, Huseyin

    2012-01-01

    Background The aim of this study was to assess the relationship between brachial artery flow mediated dilation (FMD), carotid artery intima-media thickness (IMT) and coronary flow reserve (CFR) in patients with coronary artery disease (CAD). Methods Fifty patients with coronary artery disease, except left anterior descending artery (LAD), who showed no cardiac symptoms and 45 control subjects underwent assessment of brachial artery FMD, carotid artery intima-media thickness by high-resolution ultrasound. In addition, transthoracic second harmonic Doppler echocardiography was used to measure CFR. Results All of the parameters were found to be correlated with each other. CFR correlated with brachial artery FMD (r = 0.232, P < 0.05) and with carotid IMT (r = -0.403, P < 0.001). Carotid IMT correlated with brachial artery FMD (r = -0.211, P < 0.05). Conclusion Transthoracic CFR correlated with well-established noninvasive predictors of atherosclerosis and we suggest that it can be used as a surrogate for coronary atherosclerosis.

  19. Correlation between brachial artery flow-mediated dilation and endothelial microparticle levels for identifying endothelial dysfunction in children with Kawasaki disease.

    PubMed

    Ding, Yue-Yue; Ren, Yan; Feng, Xing; Xu, Qiu-Qin; Sun, Ling; Zhang, Jian-Min; Dou, Ji-Juan; Lv, Hai-Tao; Yan, Wen-Hua

    2014-03-01

    We investigated vascular endothelial dysfunction by sonographic features of flow-mediated dilation (FMD) and circulating endothelial microparticles (EMPs) in Kawasaki disease (KD). Twenty-eight patients with KD were prospectively grouped according to stage of disease: acute, subacute, and convalescent. In addition, 28 healthy children and 28 febrile children were selected as controls. And cases in the convalescent phase were divided into two subgroups: coronary artery lesion (CAL) and no coronary lesion (NCAL). CD144(+)/CD42b(-), CD62E(+), and CD105(+) EMPs were measured by flow cytometry; FMD was obtained by sonography. There were significant differences in FMD among the five groups. When compared with healthy controls, there were significantly greater numbers of CD144(+)/CD42b(-), CD62E(+), and CD105(+) EMPs and a higher proportion of CD62E(+) EMPs in KD patients. The proportions and numbers of CD144(+)/CD42b(-), CD62E(+), and CD105(+) EMPs in KD patients were not statistically different than in febrile controls. There were no significant differences in FMD and EMPs between the CAL and NCAL subgroups. There were significantly negative correlations between the values of FMD and EMPs in the three phases of KD. The increased levels of EMPs have significant correlation with decreased values of FMD, both of which may reflect endothelial dysfunction in child KD.

  20. Relationship of levels of Vitamin D with flow-mediated dilatation of brachial artery in patients of myocardial infarction and healthy control: A case–control study

    PubMed Central

    Malik, Sarthak; Giri, Subhash; Madhu, S. V.; Rathi, Vinita; Banerjee, B. D.; Gupta, Nikhil

    2016-01-01

    Background: Cardiovascular diseases (CVD) remain the leading cause of death worldwide. Vitamin D deficiency has been linked to increased risk of adverse CV events. Vitamin D deficiency may be responsible for endothelial dysfunction which in turn affects the onset and progression of coronary artery disease and its risk factors, directly or indirectly through various mechanisms. Materials and Methods: It was case–control study. A total of 50 cases of acute myocardial infarction (AMI) (aged 40–60 years), admitted to medicine emergency/CCU, were taken as per ACC/AHA 2007 guidelines. An equal number of age- and sex-matched controls were also taken. Risk factors of AMI, flow-mediated dilatation (FMD), and 25(OH)D levels were studied in all cases and controls. Correlation was also studied between FMD and 25(OH)D. Results: The mean values of FMD were 18.86 ± 5.39% and 10.35 ± 4.90% in controls and cases, respectively (P < 0.05). The endothelial dilatation after glyceryl trinitrate (GTN) was also studied and was found to be 26.175 ± 4.25% and 18.80 ± 5.72% in controls and cases, respectively (P < 0.05). The mean levels of 25(OH)D in controls and cases were 25.45 ± 12.17 and 14.53 ± 8.28 ng/ml, respectively. In this study, 56% of subjects were Vitamin D deficient, 25% were Vitamin D insufficient, and only 19% had Vitamin D in normal range. A positive correlation coefficient was found between FMD and 25(OH) Vitamin D levels (r = 0.841, P < 0.01). In this study, a positive correlation coefficient was also found between endothelial dilatation after GTN and 25(OH)D levels (r = 0.743, P < 0.01). Conclusion: In this study, it was found that FMD was markedly impaired in patients of AMI when compared to controls. It was also found that majority of the study population was Vitamin D deficient; however, the deficiency was more severe in patients of AMI. We also found out that FMD was positively correlated (r = 0.841) to the deficiency state of Vitamin D in all the study

  1. Cardiorespiratory fitness modulates the acute flow-mediated dilation response following high-intensity but not moderate-intensity exercise in elderly men.

    PubMed

    Bailey, Tom G; Perissiou, Maria; Windsor, Mark; Russell, Fraser; Golledge, Jonathan; Green, Daniel J; Askew, Christopher D

    2017-05-01

    Impaired endothelial function is observed with aging and in those with low cardiorespiratory fitness (V̇o2peak). Improvements in endothelial function with exercise training are somewhat dependent on the intensity of exercise. While the acute stimulus for this improvement is not completely understood, it may, in part, be due to the flow-mediated dilation (FMD) response to acute exercise. We examined the hypothesis that exercise intensity alters the brachial (systemic) FMD response in elderly men and is modulated by V̇o2peak Forty-seven elderly men were stratified into lower (V̇o2peak = 24.3 ± 2.9 ml·kg(-1)·min(-1); n = 27) and higher fit groups (V̇o2peak = 35.4 ± 5.5 ml·kg(-1)·min(-1); n = 20) after a test of cycling peak power output (PPO). In randomized order, participants undertook moderate-intensity continuous exercise (MICE; 40% PPO) or high-intensity interval cycling exercise (HIIE; 70% PPO) or no-exercise control. Brachial FMD was assessed at rest and 10 and 60 min after exercise. FMD increased after MICE in both groups {increase of 0.86% [95% confidence interval (CI), 0.17-1.56], P = 0.01} and normalized after 60 min. In the lower fit group, FMD was reduced after HIIE [reduction of 0.85% (95% CI, 0.12-1.58), P = 0.02] and remained decreased at 60 min. In the higher fit group, FMD was unchanged immediately after HIIE and increased after 60 min [increase of 1.52% (95% CI, 0.41-2.62), P < 0.01, which was correlated with V̇o2peak, r = 0.41; P < 0.01]. In the no-exercise control, FMD was reduced in both groups after 60 min (P = 0.05). Exercise intensity alters the acute FMD response in elderly men and V̇o2peak modulates the FMD response following HIIE but not MICE. The sustained decrease in FMD in the lower fit group following HIIE may represent a signal for vascular adaptation or endothelial fatigue.NEW & NOTEWORTHY This study is the first to show that moderate-intensity continuous cycling exercise increased flow-mediated dilation (FMD) transiently

  2. Assessment of flow-mediated dilatation in the superficial femoral artery using a sustained shear stress stimulus via calf plantar-flexion exercise.

    PubMed

    King, T J; Schmitter, S M; Pyke, K E

    2017-06-01

    What is the central question of this study? The aim was to establish the ability of a newly designed leg exercise technique to produce sustained elevations in shear rate that stimulate flow-mediated dilatation (FMD) in the superficial femoral artery and to determine the repeat trial stability of the FMD response. What is the main finding and its importance? Calf plantar-flexion exercise can be used to increase shear stress and stimulate FMD in the superficial femoral artery. However, the magnitude of FMD varied systematically when multiple trials were repeated in short succession. The superficial femoral artery (SFA) is susceptible to vascular disease, and a technique to assess flow-mediated dilatation (FMD) in this vessel in response to a sustained shear stress stimulus could provide important information about endothelial function. The aim of this study was to establish the ability of a newly designed SFA leg exercise-FMD (LEX-FMD) technique to produce sustained elevations in shear rate, which stimulate FMD, and to determine the repeat trial stability of the FMD response. The SFA FMD stimulated by reactive hyperaemia (RH) and calf plantar-flexion exercise (LEX) was assessed via ultrasound in 19 healthy men (n = 10) and women (n = 9). The two experimental visits included either four trials of LEX-FMD or four trials of RH-FMD. The shear stress stimulus was estimated as the shear rate (blood velocity/SFA diameter). Results are expressed as the means ± SD. The LEX steady-state shear rate was consistent between trials (P = 0.176), whereas the RH shear rate area under the curve was higher in trial 1 versus trials 2-4 (P < 0.05). The %RH-FMD (four-trial mean 4.9 ± 2.5%) and absolute RH-FMD were not significantly different between trials (P = 0.465 and P = 0.359, respectively). Both %LEX-FMD and absolute LEX-FMD were higher during trial 3 (4.8 ± 3.4%) than trial 1 (3.6 ± 2.7%; P = 0.026 and P = 0.026, respectively). The magnitude of RH

  3. High dietary sodium reduces brachial artery flow-mediated dilation in humans with salt-sensitive and salt-resistant blood pressure.

    PubMed

    Matthews, Evan L; Brian, Michael S; Ramick, Meghan G; Lennon-Edwards, Shannon; Edwards, David G; Farquhar, William B

    2015-06-15

    Recent studies demonstrate that high dietary sodium (HS) impairs endothelial function in those with salt-resistant (SR) blood pressure (BP). The effect of HS on endothelial function in those with salt-sensitive (SS) BP is not currently known. We hypothesized that HS would impair brachial artery flow-mediated dilation (FMD) to a greater extent in SS compared with SR adults. Ten SR (age 42 ± 5 yr, 5 men, 5 women) and 10 SS (age 39 ± 5 yr, 5 men, 5 women) healthy, normotensive participants were enrolled in a controlled feeding study consisting of a run-in diet followed by a 7-day low dietary sodium (LS) (20 mmol/day) and a 7-day HS (300 mmol/day) diet in random order. Brachial artery FMD and 24-h BP were assessed on the last day of each diet. SS BP was individually assessed and defined as a change in 24-h mean arterial pressure (MAP) of >5 mmHg between the LS and HS diets (ΔMAP: SR -0.6 ± 1.2, SS 7.7 ± 0.4 mmHg). Brachial artery FMD was lower in both SS and SR individuals during the HS diet (P < 0.001), and did not differ between groups (P > 0.05) (FMD: SR LS 10.6 ± 1.3%, SR HS 7.2 ± 1.5%, SS LS 12.5 ± 1.7%, SS HS 7.8 ± 1.4%). These data indicate that an HS diet impairs brachial artery FMD to a similar extent in adults with SS BP and SR BP.

  4. High dietary sodium reduces brachial artery flow-mediated dilation in humans with salt-sensitive and salt-resistant blood pressure

    PubMed Central

    Matthews, Evan L.; Brian, Michael S.; Ramick, Meghan G.; Lennon-Edwards, Shannon; Edwards, David G.

    2015-01-01

    Recent studies demonstrate that high dietary sodium (HS) impairs endothelial function in those with salt-resistant (SR) blood pressure (BP). The effect of HS on endothelial function in those with salt-sensitive (SS) BP is not currently known. We hypothesized that HS would impair brachial artery flow-mediated dilation (FMD) to a greater extent in SS compared with SR adults. Ten SR (age 42 ± 5 yr, 5 men, 5 women) and 10 SS (age 39 ± 5 yr, 5 men, 5 women) healthy, normotensive participants were enrolled in a controlled feeding study consisting of a run-in diet followed by a 7-day low dietary sodium (LS) (20 mmol/day) and a 7-day HS (300 mmol/day) diet in random order. Brachial artery FMD and 24-h BP were assessed on the last day of each diet. SS BP was individually assessed and defined as a change in 24-h mean arterial pressure (MAP) of >5 mmHg between the LS and HS diets (ΔMAP: SR −0.6 ± 1.2, SS 7.7 ± 0.4 mmHg). Brachial artery FMD was lower in both SS and SR individuals during the HS diet (P < 0.001), and did not differ between groups (P > 0.05) (FMD: SR LS 10.6 ± 1.3%, SR HS 7.2 ± 1.5%, SS LS 12.5 ± 1.7%, SS HS 7.8 ± 1.4%). These data indicate that an HS diet impairs brachial artery FMD to a similar extent in adults with SS BP and SR BP. PMID:26078434

  5. Effects of carnitine supplementation on flow-mediated dilation and vascular inflammatory responses to a high-fat meal in healthy young adults.

    PubMed

    Volek, Jeff S; Judelson, Daniel A; Silvestre, Ricardo; Yamamoto, Linda M; Spiering, Barry A; Hatfield, Disa L; Vingren, Jakob L; Quann, Erin E; Anderson, Jeffrey M; Maresh, Carl M; Kraemer, William J

    2008-11-15

    Because carnitine has been shown to decrease oxidative stress and improve endothelial cell functioning, we examined the effects of carnitine supplementation on postprandial flow-mediated dilation (FMD) and circulating biomarkers of inflammation and oxidative stress after a high-fat meal. A randomized, double-blind, placebo-controlled, crossover study design was used. Thirty men and women (age 30 +/- 8 year, body mass 72.9 +/- 17.1 kg, body fat 13.0 +/- 6.4%) participated in 2 vascular testing days, each preceded by 3 weeks of supplementation with either 2 g/day of L-Carnitine (L-Carnitine L-Tartrate) or placebo with a 3- to 5-week washout period between trials. Brachial artery FMD in response to 5 minutes of upper arm occlusion and circulating markers of oxidative stress and inflammation were measured in the fasting state and after a standardized high-fat meal. After 3 weeks of supplementation, peak FMD in the fasting state was similar between the carnitine and placebo trials, averaging 6.6%. Peak FMD during the postprandial period decreased to 5.8% at 1.5 hours during placebo and increased to 7.7% during the carnitine trial (n = 30: p = 0.043 for supplement by time interaction effect). This improvement in postprandial vascular function was most dramatic in subjects who showed a decrease in peak FMD in response to the meal (n = 15: p = 0.003 for supplement by time interaction effect). There was a significant increase in postprandial lipemia and plasma interleukin-6 but no effect of supplementation. There were no significant postprandial changes or supplement effects for plasma tumor necrosis factor-alpha and malondialdehyde. In conclusion, consistent with other work showing a beneficial effect of carnitine on vascular function, these findings indicate that carnitine supplementation in healthy individuals improves postprandial FMD after a high-fat meal.

  6. Sex-specific effects of habitual aerobic exercise on brachial artery flow-mediated dilation in middle-aged and older adults.

    PubMed

    Pierce, Gary L; Eskurza, Iratxe; Walker, Ashley E; Fay, Tara N; Seals, Douglas R

    2011-01-01

    Brachial artery FMD (flow-mediated dilation) is impaired with aging and is associated with an increased risk of CVD (cardiovascular disease). In the present study, we determined whether regular aerobic exercise improves brachial artery FMD in MA/O (middle-aged/older) men and post-menopausal women. In sedentary MA/O adults (age, 55-79 years) without CVD, 8 weeks of brisk walking (6 days/week for approx. 50 min/day; randomized controlled design) increased treadmill time approx. 20% in both MA/O men (n=11) and post-menopausal women (n=15) (P<0.01), without altering body composition or circulating CVD risk factors. Brachial artery FMD increased >50% in the MA/O men (from 4.6±0.6 to 7.1±0.6%; P<0.01), but did not change in the post-menopausal women (5.1±0.8 compared with 5.4±0.7%; P=0.50). No changes occurred in the non-exercising controls. In a separate cross-sectional study (n=167), brachial artery FMD was approx. 50% greater in endurance-exercise-trained (6.4±0.4%; n=45) compared with sedentary (4.3±0.3%; n=60) MA/O men (P<0.001), whereas there were no differences between endurance-trained (5.3±0.7%, n=20) and sedentary (5.6±0.5%, n=42) post-menopausal women (P=0.70). Brachial artery lumen diameter, peak hyperaemic shear rate and endothelium-independent dilation did not differ with exercise intervention or in the endurance exercise compared with sedentary groups. In conclusion, regular aerobic exercise is consistently associated with enhanced brachial artery FMD in MA/O men, but not in post-menopausal women. Some post-menopausal women without CVD may be less responsive to habitual aerobic exercise than MA/O men.

  7. Mitochondrial sources of H2O2 generation play a key role in flow-mediated dilation in human coronary resistance arteries.

    PubMed

    Liu, Yanping; Zhao, Hongtao; Li, Hongwei; Kalyanaraman, B; Nicolosi, Alfred C; Gutterman, David D

    2003-09-19

    We previously showed that hydrogen peroxide (H2O2) contributes to flow-induced dilation in human coronary resistance arteries (HCRAs); however, the source of this H2O2 is not known. We hypothesized that the H2O2 is derived from superoxide (O2*-) generated by mitochondrial respiration. HCRAs were dissected from right atrial appendages obtained from patients during cardiac surgery and cannulated with micropipettes. H2O2-derived radicals and O2*- were detected by electron spin resonance (ESR) using BMPO as the spin trap and by histofluorescence using hydroethidine (HE, 5 micromol/L) and dichlorodihydrofluorescein (DCFH, 5 micromol/L). Diameter changes to increases in pressure gradients (20 and 100 cm H2O) were examined in the absence and the presence of rotenone (1 micromol/L), myxothiazol (100 nmol/L), cyanide (1 micromol/L), mitochondrial complex I, III, and IV inhibitors, respectively, and apocynin (3 mmol/L), a NADPH oxidase inhibitor. At a pressure gradient of 100 cm H2O, ubisemiquinone and hydroxyl radicals were detected from effluents of vessels. Including superoxide dismutase and catalase in the perfusate reduced the ESR signals. Relative ethidium and DCFH fluorescence intensities in HCRAs exposed to flow were enhanced (1.45+/-0.15 and 1.57+/-0.12, respectively compared with no-flow) and were inhibited by rotenone (0.87+/-0.17 and 0.95+/-0.07). Videomicroscopic studies showed that rotenone and myxothiazol blocked flow-induced dilation (% max. dilation at 100 cm H2O: rotenone, 74+/-3% versus 3+/-13%; myxothiazol, 67+/-3% versus 28+/-4%; P<0.05). Neither cyanide nor apocynin altered flow-induced dilation. These results suggest that shear stress induced H2O2 formation, and flow-induced dilation is derived from O2*- originating from mitochondrial respiration.

  8. Flow Mediated Dilatation, Carotid Intima Media Thickness, Ankle Brachial Pressure Index and Pulse Pressure in Young Male Post Myocardial Infarction Patients in India

    PubMed Central

    Giri, Subhash; Rathi, Vinita; Ranga, Gajender Singh

    2016-01-01

    Introduction Due to increase in Coronary Artery Disease (CAD) at a younger age, we should try to diagnose atherosclerotic process and population at risk, at the earliest. Flow Mediated Dilatation (FMD), Carotid Intima-Media Thickness (CIMT) and Ankle-Brachial Pressure Index (ABI) are probable markers for early atherosclerosis and may be useful in coronary risk stratification. Aim To compare and correlate the FMD, CIMT, ABI and Pulse Pressure (PP) in young male patients of Myocardial Infarction (MI) with age and sex matched healthy controls. Materials and Methods Eighty male patients of MI aged ≤45 years, who presented to the Cardiac Care Unit and Department of Medicine of Guru Teg Bahadur Hospital, Delhi, India, from November 2010 to April 2012 were recruited consecutively for this case control study and same number of age and sex matched healthy controls were also analyzed. Six weeks after MI, FMD of the brachial artery, intima media thickness of carotid artery, ABPI and PP were measured in the cases and compared with healthy controls. Results The FMD was lower among young patients of MI than controls (p<0.001). CIMT was higher among cases than controls (p=0.001). ABI was lower among cases than controls (p<0.001). Compared to controls, PP was higher among cases (p=0.001). In all subjects, a negative correlation between FMD and CIMT (r=–0.220, p=0.005) and a positive correlation between FMD and ABPI (r=0.304, p<0.001) was found. A statistically significant negative correlation was found between endothelial dependent FMD and PP among cases and control groups (r=–0.209, p=0.007). Conclusion Biophysical parameters were deranged in young post MI patients. Majority of our young male patients fell in low risk Framingham risk score but still they manifested with CAD. Despite six weeks of treatment among young male patients of MI, various biophysical parameters were still deranged. PMID:27891375

  9. Acute psychological and physical stress transiently enhances brachial artery flow-mediated dilation stimulated by exercise-induced increases in shear stress.

    PubMed

    Szijgyarto, Ingrid C; Poitras, Veronica J; Gurd, Brendon J; Pyke, Kyra E

    2014-08-01

    Exercise elevates conduit artery shear stress and stimulates flow-mediated dilation (FMD). However, little is known regarding the impact of acute psychological and physical stress on this response. The purpose of this study was to examine the impact of the Trier Social Stress Test (TSST (speech and arithmetic tasks)) and a cold pressor test (CPT) with and without social evaluation (SE) on exercise-induced brachial artery FMD (EX-FMD). A total of 59 healthy male subjects were randomly assigned to 1 of 3 conditions: TSST, CPT, or CPT with SE. During 6 min of handgrip exercise, brachial artery EX-FMD was assessed before and 15 and 35 min poststress with echo and Doppler ultrasound. Shear stress was estimated as shear rate, calculated as brachial artery mean blood velocity/brachial artery diameter. Results are means ± SD. All conditions elicited significant physiological stress responses. Salivary cortisol increased from 4.6 ± 2.4 nmol/L to 10.0 ± 5.0 nmol/L (p < 0.001; condition effect: p = 0.292). Mean arterial pressure increased from 98.6 ± 12.1 mm Hg to 131.9 ± 18.7 mm Hg (p < 0.001; condition effect: p = 0.664). Exercise shear rate did not differ between conditions (p = 0.592), although it was modestly lower poststress (prestress: 72.3 ± 4.5 s(-1); 15 min poststress: 70.8 ± 5.4 s(-1); 35 min poststress: 70.6 ± 6.1 s(-1); trial effect: p = 0.011). EX-FMD increased from prestress to 15 min poststress in all conditions (prestress: 6.2% ± 2.8%; 15 min poststress: 7.9% ± 3.2%; 35 min poststress: 6.6% ± 2.9%; trial effect: p < 0.001; condition effect: p = 0.611). In conclusion, all conditions elicited similar stress responses that transiently enhanced EX-FMD. This response may help to support muscle perfusion during stress.

  10. Endothelial Function Is Impaired in Patients Receiving Antihypertensive Drug Treatment Regardless of Blood Pressure Level: FMD-J Study (Flow-Mediated Dilation Japan).

    PubMed

    Maruhashi, Tatsuya; Soga, Junko; Fujimura, Noritaka; Idei, Naomi; Mikami, Shinsuke; Iwamoto, Yumiko; Iwamoto, Akimichi; Kajikawa, Masato; Matsumoto, Takeshi; Oda, Nozomu; Kishimoto, Shinji; Matsui, Shogo; Hashimoto, Haruki; Aibara, Yoshiki; Yusoff, Farina Binti Mohamad; Hidaka, Takayuki; Kihara, Yasuki; Chayama, Kazuaki; Noma, Kensuke; Nakashima, Ayumu; Goto, Chikara; Tomiyama, Hirofumi; Takase, Bonpei; Kohro, Takahide; Suzuki, Toru; Ishizu, Tomoko; Ueda, Shinichiro; Yamazaki, Tsutomu; Furumoto, Tomoo; Kario, Kazuomi; Inoue, Teruo; Koba, Shinji; Watanabe, Kentaro; Takemoto, Yasuhiko; Hano, Takuzo; Sata, Masataka; Ishibashi, Yutaka; Node, Koichi; Maemura, Koji; Ohya, Yusuke; Furukawa, Taiji; Ito, Hiroshi; Ikeda, Hisao; Yamashina, Akira; Higashi, Yukihito

    2017-10-01

    Hypertension is associated with endothelial dysfunction. Blood pressure significantly correlates with endothelial function in antihypertensive drug-naive subjects. The purpose of this study was to determine whether treatment status affects the relationship between blood pressure and endothelial function. We measured flow-mediated vasodilation (FMD) in 2297 subjects, including 1822 antihypertensive drug-naive subjects and 475 treated hypertensive patients. FMD significantly decreased in relation to increase in systolic blood pressure (8.2±3.1% in subjects with systolic blood pressure of <120 mm Hg, 7.5±2.8% for 120-129 mm Hg, 7.1±2.8% for 130-139 mm Hg, and 6.7±2.6% for ≥140 mm Hg; P<0.001). Systolic blood pressure was independently associated with FMD in untreated subjects. In contrast, there was no significant relationship between systolic blood pressure and FMD in treated hypertensive patients (4.6±3.1% in treated hypertensives with systolic blood pressure of <120 mm Hg, 4.8±2.7% for 120-129 mm Hg, 4.9±2.8% for 130-139 mm Hg, and 4.5±2.3% for ≥140 mm Hg; P=0.77). Propensity score matching analysis revealed that the prevalence of endothelial dysfunction defined as FMD of less than the division point for the lowest tertile, and the middle tertile of FMD was significantly higher in treated hypertensive patients than in untreated subjects in all systolic blood pressure categories. Endothelial function assessed by FMD was impaired regardless of the level of blood pressure achieved by antihypertensive drug treatment in hypertensive patients. © 2017 American Heart Association, Inc.

  11. Long-term effects of weight loss with a very-low carbohydrate, low saturated fat diet on flow mediated dilatation in patients with type 2 diabetes: A randomised controlled trial.

    PubMed

    Wycherley, Thomas P; Thompson, Campbell H; Buckley, Jonathan D; Luscombe-Marsh, Natalie D; Noakes, Manny; Wittert, Gary A; Brinkworth, Grant D

    2016-09-01

    Very-low carbohydrate diets can improve glycaemic control in patients with type 2 diabetes (T2DM). However, compared to traditional higher carbohydrate, low fat (HighCHO) diets, they have been associated with impaired endothelial function (measured by flow mediated dilatation [FMD]) that is possibly related to saturated fat. This study aimed to examine the effects of a 12-month hypocaloric very-low carbohydrate, low saturated fat (LowCHO) diet compared to an isocaloric HighCHO diet. One hundred and fifteen obese patients with T2DM (age:58.4 ± 0.7 [SEM] yr, BMI:34.6 ± 0.4 kg/m(2), HbA1c:7.33 [56.3 mmol/mol] ± 0.10%) were randomised to consume an energy restricted LowCHO diet (Carb:Pro:Fat:Sat-Fat 14:28:58: < 10% energy; n = 58) or isocaloric HighCHO diet (53:17:30: < 10%; n = 57) whilst undertaking exercise (60 min, 3/wk). Bodyweight, HbA1c and FMD were assessed. Seventy eight participants completed the intervention (LowCHO = 41, HighCHO = 37). Both groups experienced similar reductions in weight and HbA1c (-10.6 ± 0.7 kg, -1.05 ± 0.10%; p < 0.001 time, p ≥ 0.48 time × diet). FMD did not change (p = 0.11 time, p = 0.20 time × diet). In patients with obesity and T2DM, HighCHO diet and LowCHO diet have similar effects on endothelial function. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  12. AGEs breaking and antioxidant treatment improves endothelium-dependent dilation without effect on flow-mediated remodeling of resistance arteries in old Zucker diabetic rats

    PubMed Central

    2014-01-01

    Background A chronic increase in blood flow in resistance arteries is associated with increased lumen diameter (outward remodeling) and improved endothelium (NO)-mediated relaxation. Flow-mediated remodeling of resistance arteries is essential for revascularization in ischemic diseases. Nevertheless, it is impaired in 12 to 24-month old rats and in young Zucker Diabetic Fatty (ZDF) rats due to advanced glycation end products (AGEs) and oxidative stress. As type 2 diabetes occurs preferentially in older subjects we investigated flow-mediated remodeling and the effect of the AGEs breaker ALT-711 associated or not to the antioxidant TEMPOL in one-year old lean (LZ) and ZDF rats. Methods Mesenteric resistance arteries were exposed to high (HF) or normal blood flow (NF) in vivo. They were collected after 2 weeks for in vitro analysis. Results In LZ rats, diameter expansion did not occur despite a significant increase in blood flow in HF arteries. Nevertheless, endothelium-mediated relaxation was higher in HF than in NF arteries. ALT-711, alone or in combination with TEMPOL, restored outward remodeling in HF arteries in association with AGEs reduction. TEMPOL alone had no effect. ALT-711, TEMPOL or the combination of the 2 drugs did not significantly affect endothelium-mediated relaxation in HF and NF arteries. In ZDF rats, diameter did not increase despite the increase in blood flow and endothelium-mediated relaxation was further decreased in HF arteries in association with AGEs accumulation and excessive oxidative stress. In both NF and HF arteries, endothelium-mediated relaxation was lower in ZDF than in LZ rats. ALT-711, TEMPOL or their combination did not improve remodeling (diameter equivalent in HF and NF arteries). In parallel, they did not reduce AGEs level and did not improve MMPs activity. Nevertheless, ALT-711 and TEMPOL partly improved endothelium-mediated relaxation through a reduction of oxidative stress and the association of ALT-711 and TEMPOL fully

  13. AGEs breaking and antioxidant treatment improves endothelium-dependent dilation without effect on flow-mediated remodeling of resistance arteries in old Zucker diabetic rats.

    PubMed

    Freidja, Mohamed L; Vessières, Emilie; Toutain, Bertrand; Guihot, Anne-Laure; Custaud, Marc-Antoine; Loufrani, Laurent; Fassot, Céline; Henrion, Daniel

    2014-03-03

    A chronic increase in blood flow in resistance arteries is associated with increased lumen diameter (outward remodeling) and improved endothelium (NO)-mediated relaxation. Flow-mediated remodeling of resistance arteries is essential for revascularization in ischemic diseases. Nevertheless, it is impaired in 12 to 24-month old rats and in young Zucker Diabetic Fatty (ZDF) rats due to advanced glycation end products (AGEs) and oxidative stress. As type 2 diabetes occurs preferentially in older subjects we investigated flow-mediated remodeling and the effect of the AGEs breaker ALT-711 associated or not to the antioxidant TEMPOL in one-year old lean (LZ) and ZDF rats. Mesenteric resistance arteries were exposed to high (HF) or normal blood flow (NF) in vivo. They were collected after 2 weeks for in vitro analysis. In LZ rats, diameter expansion did not occur despite a significant increase in blood flow in HF arteries. Nevertheless, endothelium-mediated relaxation was higher in HF than in NF arteries. ALT-711, alone or in combination with TEMPOL, restored outward remodeling in HF arteries in association with AGEs reduction. TEMPOL alone had no effect. ALT-711, TEMPOL or the combination of the 2 drugs did not significantly affect endothelium-mediated relaxation in HF and NF arteries.In ZDF rats, diameter did not increase despite the increase in blood flow and endothelium-mediated relaxation was further decreased in HF arteries in association with AGEs accumulation and excessive oxidative stress. In both NF and HF arteries, endothelium-mediated relaxation was lower in ZDF than in LZ rats. ALT-711, TEMPOL or their combination did not improve remodeling (diameter equivalent in HF and NF arteries). In parallel, they did not reduce AGEs level and did not improve MMPs activity. Nevertheless, ALT-711 and TEMPOL partly improved endothelium-mediated relaxation through a reduction of oxidative stress and the association of ALT-711 and TEMPOL fully restored relaxation to the

  14. Impaired flow-mediated dilation response and carotid intima-media thickness in patients with type 1 diabetes mellitus with a mean disease duration of 4.1 years.

    PubMed

    Tacito, Lúcia Helena Bonalume; Pires, Antonio Carlos; Yugar-Toledo, Juan Carlos

    2017-07-13

    This study aimed at assessing the endothelial function in patients with Type 1 diabetes (T1DM) using flow-mediated dilation (FMD) response and carotid artery intima-media thickness (CIMT). This study enrolled 32 T1DM patients (mean disease duration 4.1 years) and 28 age-matched controls (CTL Group). Endothelial function and CIMT were assessed with high-resolution ultrasound using standardized offline measurements. FMD was significantly lower in patients in the T1DM Group (8.9 ± 3.2%) compared with those in the CTL Group (13.3 ± 4.3%; P-value < 0.0001). Similarly, CIMT differed significantly between T1DM patients (0.525 ± 0.03 mm) and controls (0.508 ± 0.03 mm; P-value = 0.041). Even though, the values are within the normal range for age. Patients with T1DM have impaired endothelial function characterized by reduced FMD when compared to controls. However, vascular remodeling as seen by increases in CIMT was not found in this study.

  15. Relation of Season and Temperature to Endothelium-Dependent Flow-Mediated Vasodilation in Subjects Without Clinical Evidence of Cardiovascular Disease (From The Framingham Heart Study)

    PubMed Central

    Widlansky, Michael E.; Vita, Joseph A.; Keyes, Michelle J.; Larson, Martin G.; Hamburg, Naomi M.; Levy, Daniel; Mitchell, Gary F.; Osypiuk, Ewa W.; Vasan, Ramachandran S.; Benjamin, Emelia J.

    2007-01-01

    Multiple studies have documented an increased incidence of cardiovascular events in the winter, but the pathophysiological mechanisms remain incompletely understood. We hypothesized that brachial flow and flow-mediated dilation (FMD) would vary by season and temperature. We related season and temperature to ultrasonic brachial artery endothelium-dependent FMD% (n=2587), baseline flow velocity and maximal reactive hyperemia (n=1973) in the Framingham Offspring cohort (mean age 61±10 years; 53% women). We obtained outdoor temperature from National Climate Data Center records for Bedford, Massachusetts (about 14 miles from testing site) and we measured the examination room temperature. In multivariable models, FMD% was highest in summer and lowest in winter (3.01±0.09 vs. 2.56±0.10%, respectively; P=0.02 for differences across all 4 seasons). FMD% was highest in the warmest and lowest in the coldest outdoor temperature quartiles. In stepwise models adjusting for risk factors, and selecting among season, outdoor temperature, and room temperature, FMD% was associated with season (P=0.02); temperature did not enter the model. In contrast, hyperemic flow velocity was significantly lower for cooler, and higher for warmer room temperatures (P=0.02 overall); season did not enter the model. Season, outdoor and room temperature were each retained in a stepwise model of baseline flow velocity (P<0.0001, P=0.02, P<0.0001, respectively). In conclusion, we observed a significant association between season and FMD. Microvascular vasodilator function, as reflected by hyperemic flow, was more strongly related to temperature than season. In conclusion, we speculate that endothelial dysfunction may be 1 of the mechanisms influencing seasonal variation in cardiovascular events. PMID:17659939

  16. Relation of improvement in endothelium-dependent flow-mediated vasodilation after rosiglitazone to changes in asymmetric dimethylarginine, endothelin-1, and C-reactive protein in nondiabetic patients with the metabolic syndrome.

    PubMed

    Wang, Tzung-Dau; Chen, Wen-Jone; Cheng, Wern-Cherng; Lin, Jong-Wei; Chen, Ming-Fong; Lee, Yuan-Teh

    2006-10-15

    The mechanisms by which thiazolidinediones exert beneficial effects on the endothelium are still not clear. We examined the effects of rosiglitazone on the plasma markers of metabolic control (glucose, insulin, adiponectin, resistin, and lipid profiles), markers of inflammation (high-sensitivity C-reactive protein [CRP], interleukin-6, soluble CD40 ligand, intercellular adhesion molecule-1, and vascular cell adhesion molecule-1), and markers of vasoreactivity (asymmetric dimethylarginine [ADMA] and endothelin-1) and analyzed the relations between changes in endothelium-dependent flow-mediated dilation of the brachial artery and changes in these markers to elucidate their roles in mediating the vascular protective effects of rosiglitazone. Of 70 nondiabetic patients who met a modified National Cholesterol Education Program definition of the metabolic syndrome, 35 were randomized to receive rosiglitazone (4 mg/day) and 35 to receive placebo for 8 weeks. At study end, treatment with rosiglitazone had significantly reduced plasma insulin (-25%, p = 0.004) and resistin (-16%, p <0.001), increased adiponectin (164%, p <0.001), low-density lipoprotein cholesterol (16%, p = 0.005), and apolipoprotein-B (14%, p = 0.003), and decreased CRP (-30%, p = 0.005), soluble CD40 ligand (-20%, p = 0.014), ADMA (-16%, p <0.001), and endothelin-1 (-11%, p <0.001) concentrations and systolic and diastolic blood pressures. Rosiglitazone treatment significantly improved flow-mediated dilation (p <0.001) and nitroglycerin-induced vasodilation (p = 0.001) of the right brachial artery. On multivariate analysis, changes in ADMA, endothelin-1, and CRP were independent predictors of improved endothelial reactivity with rosiglitazone. In conclusion, we have, for the first time, demonstrated the independent associations between the improvement in flow-mediated dilation and reductions in ADMA, endothelin-1, and CRP after 8 weeks of treatment with rosiglitazone in nondiabetic patients with the

  17. Combined Therapy with Renin-Angiotensin System and Calcium Channel Blockers in Type 2 Diabetic Hypertensive Patients with Proteinuria: Effects on Soluble TWEAK, PTX3, and Flow-Mediated Dilation

    PubMed Central

    Yilmaz, Mahmut Ilker; Carrero, Juan Jesús; Martín-Ventura, Jose Luis; Sonmez, Alper; Saglam, Mutlu; Celik, Turgay; Yaman, Halil; Yenicesu, Mujdat; Eyileten, Tayfun; Moreno, Juan Antonio; Egido, Jesús

    2010-01-01

    Background and objectives: Soluble TNF-like weak inducer of apoptosis (sTWEAK) and long pentraxin-3 (PTX3) concentrations have been associated with endothelial function in patients with chronic kidney disease (CKD). This study tested the hypothesis that the improvement in endothelial function after initiation of angiotensin II receptor blocker (valsartan), calcium channel blocker (amlodipine) therapy, or a combination of both is directly linked to the normalization of sTWEAK and PTX3. Design, setting, participants, & measurements: One-hundred-eight diabetic CKD stage I patients with hypertension (56% men, 46.7 ± 5.3 years) were allocated to a 12-week intervention with amlodipine (10 mg/d), valsartan (160 mg/d), or their combination. Plasma levels of sTWEAK, PTX3, and flow-mediated dilation (FMD) were studied during the interventions. Results: All treatment strategies effectively increased FMD and reduced proteinuria, confirming a more prone reduction with the combined therapy. These improvements were followed by significant PTX3 reductions. Valsartan alone and in combination with amlodipine achieved significant incremental raises in sTWEAK plasma levels. More importantly, the changes observed in sTWEAK (β = 0.25, P = 0.006) or PTX3 (β = −0.24, P = 0.007) plasma levels were independently associated with the improvement in ultrasonographically measured FMD. Conclusions: This study shows that treatment with antihypertensive drugs improves FMD and normalizes proteinuria, PTX3, and sTWEAK in diabetic CKD stage I patients with hypertension. The improvement in FMD was independently associated with PTX3 and sTWEAK normalization. Two surrogate biomarkers of endothelial function are therefore identified with potential as therapeutic targets. The study was registered in clinicaltrials.gov as NCT00921570. PMID:20430947

  18. Improved test of time dilation in special relativity.

    PubMed

    Saathoff, G; Karpuk, S; Eisenbarth, U; Huber, G; Krohn, S; Muñoz Horta, R; Reinhardt, S; Schwalm, D; Wolf, A; Gwinner, G

    2003-11-07

    An improved test of time dilation in special relativity has been performed using laser spectroscopy on fast ions at the heavy-ion storage-ring TSR in Heidelberg. The Doppler-shifted frequencies of a two-level transition in 7Li+ ions at v=0.064c have been measured in the forward and backward direction to an accuracy of Deltanu/nu=1 x 10(-9) using collinear saturation spectroscopy. The result confirms the relativistic Doppler formula and sets a new limit of 2.2 x 10(-7) for deviations from the time dilation factor gamma(SR)=(1-v2/c2)(-1/2).

  19. The computational power of time dilation in special relativity

    NASA Astrophysics Data System (ADS)

    Biamonte, Jacob

    2014-03-01

    The Lorentzian length of a timelike curve connecting both endpoints of a classical computation is a function of the path taken through Minkowski spacetime. The associated runtime difference is due to time-dilation: the phenomenon whereby an observer finds that another's physically identical ideal clock has ticked at a different rate than their own clock. Using ideas appearing in the framework of computational complexity theory, time-dilation is quantified as an algorithmic resource by relating relativistic energy to an nth order polynomial time reduction at the completion of an observer's journey. These results enable a comparison between the optimal quadratic Grover speedup from quantum computing and an n=2 speedup using classical computers and relativistic effects. The goal is not to propose a practical model of computation, but to probe the ultimate limits physics places on computation. Parts of this talk are based on [J.Phys.Conf.Ser. 229:012020 (2010), arXiv:0907.1579]. Support is acknowledged from the Foundational Questions Institute (FQXi) and the Compagnia di San Paolo Foundation.

  20. Serum nitric oxide levels and flow-mediated dilatation in patients with Sheehan syndrome and the effect of combination therapy consisting of L-thyroxine, prednisolone, and conjugated estrogen/medroxyprogesterone acetate.

    PubMed

    Bahceci, Mithat; Pasa, Semir; Akay, Hatice O; Tuzcu, Alpaslan; Tumer, Cemil; Gokalp, Deniz

    2008-04-01

    Baseline and stimulated nitric oxide (NO) levels were higher, whereas baseline arterial diameter, FMD-stimulated NO increment, and arterial dilatation ratio were lower in Sheehan syndrome (SS) patients than in control subjects. After combination therapy consisting of prednisolone, L-thyroxine, and conjugated estrogen, baseline and stimulated NO levels of SS remained as high, but FMD-stimulated NO, NO increment ratio, and arterial dilatation ratio increased with treatment.

  1. Neural Correlates of Fast Pupil Dilation in Nonhuman Primates: Relation to Behavioral Performance and Cognitive Workload

    PubMed Central

    Hampson, R.E.; Opris, Ioan; Deadwyler, S.A.

    2010-01-01

    Pupil dilation in humans has been previously shown to correlate with cognitive workload, whereby increased frequency of dilation is associated with increased degree of difficulty of a task. It has been suggested that frontal oculomotor brain areas control cognitively-related pupil dilations, but this has not been confirmed due to lack of animal models of cognitive workload and task-related pupil dilation. This is the first report of a wavelet analysis applied to continuous measures of pupil size used to detect the onset of abrupt pupil dilations and the frequency of those dilations in nonhuman primates (NHPs) performing a trial-unique delayed match to sample (DMS) task. An additional unique finding shows that electrophysiological recordings in the same animals revealed correlated firing of neurons in frontal cortex with different components of pupil dilation during task performance. It is further demonstrated that the frequency of fast pupil dilations (but not rate of eye movements) correlated with cognitive workload during task performance. Such correlations suggest that frontal neuron encoding of pupil dilation provides critical feedback to other brain areas involved in the processing of complex visual information. PMID:20226215

  2. Severity of mastalgia in relation to milk duct dilatation.

    PubMed

    Peters, Friedolf; Diemer, Petra; Mecks, Olaf; Behnken L, Lütje J

    2003-01-01

    The etiology of mastalgia is poorly understood. Histology cannot detect any distinct characteristics. This investigation therefore applied ultrasonography to mastalgia patients to investigate morphological structures and to obtain further insights into the pathophysiology of mastalgia. The aim of the study was to analyze the significance of milk duct dilatation in patients with mastalgia. A total of 335 premenopausal women participated in a genital and breast cancer screening program. Of these, 123 women were asymptomatic and 212 complained of breast pain (136 had cyclical mastalgia; 76 reported the noncyclical type). The width of milk ducts was measured by ultrasonography and correlated with the intensity of breast pain. The site of the pain was correlated with duct dilatation. Statistical analysis was performed using the t test, the chi(2) test, analysis of variance, and Pearson correlation. In asymptomatic women, the maximum mean width of the milk ducts was 1.8 +/- 0.84 mm, in cyclical mastalgia 2.34 +/- 1.10 mm, and 3.89 +/- 1.26 mm in noncyclical mastalgia (P <.001). The intensity of pain showed a significant, positive correlation with the width of the milk ducts (r =.5008, P <.001). Noncyclical mastalgia patients located the pain at the site where dilated ducts were detected ultrasonographically (P <.001). The results of this study demonstrate that duct ectasia is a major factor in mastalgia. The degree of duct dilatation correlates positively with the intensity of breast pain. In the noncyclical type of pain, there is a positive correlation between the site of duct dilatation and the site of pain.

  3. Relating Pupil Dilation and Metacognitive Confidence during Auditory Decision-Making.

    PubMed

    Lempert, Karolina M; Chen, Yu Lin; Fleming, Stephen M

    2015-01-01

    The sources of evidence contributing to metacognitive assessments of confidence in decision-making remain unclear. Previous research has shown that pupil dilation is related to the signaling of uncertainty in a variety of decision tasks. Here we ask whether pupil dilation is also related to metacognitive estimates of confidence. Specifically, we measure the relationship between pupil dilation and confidence during an auditory decision task using a general linear model approach to take into account delays in the pupillary response. We found that pupil dilation responses track the inverse of confidence before but not after a decision is made, even when controlling for stimulus difficulty. In support of an additional post-decisional contribution to the accuracy of confidence judgments, we found that participants with better metacognitive ability - that is, more accurate appraisal of their own decisions - showed a tighter relationship between post-decisional pupil dilation and confidence. Together our findings show that a physiological index of uncertainty, pupil dilation, predicts both confidence and metacognitive accuracy for auditory decisions.

  4. Relating Pupil Dilation and Metacognitive Confidence during Auditory Decision-Making

    PubMed Central

    Lempert, Karolina M.; Chen, Yu Lin; Fleming, Stephen M.

    2015-01-01

    The sources of evidence contributing to metacognitive assessments of confidence in decision-making remain unclear. Previous research has shown that pupil dilation is related to the signaling of uncertainty in a variety of decision tasks. Here we ask whether pupil dilation is also related to metacognitive estimates of confidence. Specifically, we measure the relationship between pupil dilation and confidence during an auditory decision task using a general linear model approach to take into account delays in the pupillary response. We found that pupil dilation responses track the inverse of confidence before but not after a decision is made, even when controlling for stimulus difficulty. In support of an additional post-decisional contribution to the accuracy of confidence judgments, we found that participants with better metacognitive ability – that is, more accurate appraisal of their own decisions – showed a tighter relationship between post-decisional pupil dilation and confidence. Together our findings show that a physiological index of uncertainty, pupil dilation, predicts both confidence and metacognitive accuracy for auditory decisions. PMID:25950839

  5. A Simple Derivation of Time Dilation and Length Contraction in Special Relativity

    ERIC Educational Resources Information Center

    Behroozi, Fred

    2014-01-01

    Undergraduate physics majors typically begin their study of modern physics with special relativity. It is here that physics students first encounter the counterintuitive concepts of time dilation and length contraction. Unfortunately, the derivations of these results are often cloaked in several layers of analysis that render them rather…

  6. A Simple Derivation of Time Dilation and Length Contraction in Special Relativity

    ERIC Educational Resources Information Center

    Behroozi, Fred

    2014-01-01

    Undergraduate physics majors typically begin their study of modern physics with special relativity. It is here that physics students first encounter the counterintuitive concepts of time dilation and length contraction. Unfortunately, the derivations of these results are often cloaked in several layers of analysis that render them rather…

  7. Flow mediated endothelium function: advantages of an automatic measuring technique

    NASA Astrophysics Data System (ADS)

    Maio, Yamila; Casciaro, Mariano E.; José Urcola y, Maria; Craiem, Damian

    2007-11-01

    The objective of this work is to show the advantages of a non invasive automated method for measuring flow mediated dilation (FMD) in the forearm. This dilation takes place in answer to a shear tension generated by the increase of blood flow, sensed by the endothelium, after the liberation of an occlusion sustained in the time. The method consists of three stages: the continuous acquisition of images of the brachial artery using ultrasound techniques, the pulse to pulse measurement of the vessel's diameter by means of a border detection algorithm, and the later analysis of the results. By means of this technique one cannot only obtain the maximum dilation percentage (FMD%), but a continuous diameter curve that allows to evaluate other relevant aspects such as dilation speed, dilation sustain in time and general maneuver performance. The simplicity of this method, robustness of the technique and accessibility of the required elements makes it a viable alternative of great clinical value for diagnosis in the early detection of numerous cardiovascular pathologies.

  8. Late gadolinium enhanced cardiovascular magnetic resonance of lamin A/C gene mutation related dilated cardiomyopathy

    PubMed Central

    2011-01-01

    Background The purpose of this study was to identify early features of lamin A/C gene mutation related dilated cardiomyopathy (DCM) with cardiovascular magnetic resonance (CMR). We characterise myocardial and functional findings in carriers of lamin A/C mutation to facilitate the recognition of these patients using this method. We also investigated the connection between myocardial fibrosis and conduction abnormalities. Methods Seventeen lamin A/C mutation carriers underwent CMR. Late gadolinium enhancement (LGE) and cine images were performed to evaluate myocardial fibrosis, regional wall motion, longitudinal myocardial function, global function and volumetry of both ventricles. The location, pattern and extent of enhancement in the left ventricle (LV) myocardium were visually estimated. Results Patients had LV myocardial fibrosis in 88% of cases. Segmental wall motion abnormalities correlated strongly with the degree of enhancement. Myocardial enhancement was associated with conduction abnormalities. Sixty-nine percent of our asymptomatic or mildly symptomatic patients showed mild ventricular dilatation, systolic failure or both in global ventricular analysis. Decreased longitudinal systolic LV function was observed in 53% of patients. Conclusions Cardiac conduction abnormalities, mildly dilated LV and depressed systolic dysfunction are common in DCM caused by a lamin A/C gene mutation. However, other cardiac diseases may produce similar symptoms. CMR is an accurate tool to determine the typical cardiac involvement in lamin A/C cardiomyopathy and may help to initiate early treatment in this malignant familiar form of DCM. PMID:21689390

  9. Receptive Vocabulary Knowledge in Low-Functioning Autism as Assessed by Eye Movements, Pupillary Dilation, and Event-Related Potentials

    DTIC Science & Technology

    2012-06-01

    INTRODUCTION Approximately 50% of individuals affected by autism fail to develop useful speech , and many of these individuals never learn to communicate...Functioning Autism as Assessed by Eye Movements, Pupillary Dilation, and Event-Related Potentials PRINCIPAL INVESTIGATOR: Barry Gordon...Knowledge in Low-Functioning Autism as Assessed by Eye- Movements, Pupillary Dilation, and Event-Related Potentials 5b. GRANT NUMBER W81XWH-10-1-0404

  10. Left ventricular chamber dilatation in hypertrophic cardiomyopathy: related variables and prognosis in patients with medical and surgical therapy.

    PubMed Central

    Seiler, C.; Jenni, R.; Vassalli, G.; Turina, M.; Hess, O. M.

    1995-01-01

    BACKGROUND--To determine the incidence and prognosis of left ventricular dilatation and systolic dysfunction in 139 patients with hypertrophic cardiomyopathy during long term follow up. METHODS--Left ventricular chamber dilatation and systolic dysfunction (both together referred to as left ventricular chamber dilatation) were determined echocardiographically. Chamber dilatation was defined as an increase in the left ventricular end diastolic diameter of > 2% per year combined with a decrease in midventricular systolic fractional shortening of > 2% per year of follow up [10.3 (SD 6) years]. The predictive value for left ventricular chamber dilatation of clinical, invasive, and echocardiographic variables and its prognosis were assessed. RESULTS--In 119 of 139 individuals (86%), left ventricular chamber size and systolic function remained stable (group 1), and in 20/139 patients (14%) left ventricular chamber dilatation occurred during follow up (group 2). At baseline examination, symptoms such as dyspnoea and syncope occurred less often in group 1 than in group 2; New York Heart Association classification was lower in group 1 than in group 2 (P = 0.001). Left ventricular mass index relative to sex specific normal values was increased by 18% in group 1 and by 41% in group 2 (P = 0.04). Cumulative survival rates were slightly although not significantly higher in group 1 than in group 2. Event-free survival was significantly higher in group 1 than in group 2 (P < 0.05). CONCLUSIONS--(1) The development of left ventricular chamber dilatation and systolic dysfunction in hypertrophic cardiomyopathy occurs in approximately 1.5% of the patients per year. (2) Factors associated with left ventricular dilatation are dyspnoea, syncope, a higher functional classification, and a higher degree of left ventricular hypertrophy. (3) Patients with chamber dilatation have a worse prognosis than those without, particularly regarding quality of life. PMID:8562235

  11. Relations between fetal head descent and cervical dilatation during individual uterine contractions in the active stage of labor.

    PubMed

    Barnea, Ofer; Luria, Oded; Jaffa, Ariel; Stark, Michael; Fox, Harold E; Farine, Dan

    2009-08-01

    The relationship between instantaneous changes in fetal head station and cervical dilatation within the individual contraction during the active stage of labor were studied and an index of labor progress was suggested. Cervix dilatation and fetal head station were measured continuously in 30 nullipara women (mean age 27.5, standard deviation 4.8). The continuous measurements enabled the analysis of each variable and the analysis of the relations between these two variables. The relationship between the head station and the cervical dilatation were demonstrated by plotting one against the other during a contraction. This led to the definition of a contraction vector that integrates the interaction between the two variables. The angle of this vector, that indicates this relation, was plotted against mean head station to demonstrate change along the delivery process regardless of time to normalize the progress and allow comparison between different women with different labor durations. This plot showed a sharp change from almost zero into a steep curve at about zero head station. A zero angle indicates that the cervix dilates during a contraction with little effect on head station while a steep angle indicates a significant effect of cervical dilatation on head station during the contraction. The contraction-vector angle reflects the changing intra-contraction relationship between head station and cervical dilatation. The angle of this vector may serve as an indicator of labor progress.

  12. Effect of fructose and sucralose on flow-mediated vasodilatation in healthy, white European males.

    PubMed

    Memon, Muhammad Qasim; Simpson, Elizabeth Jane; Macdonald, Ian Andrew

    2014-07-01

    To assess how acute consumption of fructose affects flow-mediated dilatation in brachial artery. The randomised cross-over study was conducted at the University of Nottingham's Medical School, Nottingham, United Kingdom in July 2009. Ten healthy, white European males visited the laboratory twice, on separate mornings. On each visit, the volunteers consumed water (3 ml/kg bodyweight) and rested semi-supine on the bed. After 30 minutes, baseline diastolic brachial artery diameter and blood velocity was measured. At 60 minutes, blood velocity and five scans of brachial artery diameter were recorded before a blood pressure cuff was inflated on the forearm for 5 minutes and at 50-60-70-80 and 90 sec after cuff deflation. Fifteen minutes later, the volunteers consumed 500 ml of test-drink containing either fructose (0.75 g/kg bodyweight) or sucralose (sweetness-matched with fructose drink); 45 minutes later, baseline and flow-mediated dilatation was re-measured. Pre-drink and post-drink baseline values were similar on two occasions (p > 0.05). Brachial artery diameter increased (p < 0.05) by 7 +/- 3% pre-fructose and by 6.9 +/- 3% above baseline values post-fructose with no significant difference in these responses (p < 0.15). It increased (p < 0.05) by 5.9 +/- 3% above baseline before and by 6.7 +/- 2% (p < 0.01) after sucralose; a significant difference was noted in these flow-mediated dilatation responses (p < 0.02). Responses before and after sucralose were not different from those before and after fructose (p < 0.294). Acute ingestion of fructose or sucralose had no effect on flow-mediated dilatation measured at brachial artery.

  13. Heart rate variability in idiopathic dilated cardiomyopathy: relation to disease severity and prognosis.

    PubMed Central

    Yi, G.; Goldman, J. H.; Keeling, P. J.; Reardon, M.; McKenna, W. J.; Malik, M.

    1997-01-01

    OBJECTIVE: To assess the clinical importance of heart rate variability (HRV) in patients with idiopathic dilated cardiomyopathy (DCM). PATIENTS AND METHODS: Time domain analysis of 24 hour HRV was performed in 64 patients with DCM, 19 of their relatives with left ventricular enlargement (possible early DCM), and 33 healthy control subjects. RESULTS: Measures of HRV were reduced in patients with DCM compared with controls (P < 0.05). HRV parameters were similar in relatives and controls. Measures of HRV were lower in DCM patients in whom progressive heart failure developed (n = 28) than in those who remained clinically stable (n = 36) during a follow up of 24 (20) months (P = 0.0001). Reduced HRV was associated with NYHA functional class, left ventricular end diastolic dimension, reduced left ventricular ejection fraction, and peak exercise oxygen consumption (P < 0.05) in all patients. DCM patients with standard deviation of normal to normal RR intervals calculated over the 24 hour period (SDNN) < 50 ms had a significantly lower survival rate free of progressive heart failure than those with SDNN > 50 ms (P = 0.0002, at 12 months; P = 0.0001, during overall follow up). Stepwise multiple regression analysis showed that SDNN < 50 ms identified, independently of other clinical variables, patients who were at increased risk of developing progressive heart failure (P = 0.0004). CONCLUSIONS: HRV is reduced in patients with DCM and related to disease severity. HRV is clinically useful as an early non-invasive marker of DCM deterioration. PMID:9068391

  14. Decision-related pupil dilation reflects upcoming choice and individual bias

    PubMed Central

    de Gee, Jan Willem; Knapen, Tomas; Donner, Tobias H.

    2014-01-01

    A number of studies have shown that pupil size increases transiently during effortful decisions. These decision-related changes in pupil size are mediated by central neuromodulatory systems, which also influence the internal state of brain regions engaged in decision making. It has been proposed that pupil-linked neuromodulatory systems are activated by the termination of decision processes, and, consequently, that these systems primarily affect the postdecisional brain state. Here, we present pupil results that run contrary to this proposal, suggesting an important intradecisional role. We measured pupil size while subjects formed protracted decisions about the presence or absence (“yes” vs. “no”) of a visual contrast signal embedded in dynamic noise. Linear systems analysis revealed that the pupil was significantly driven by a sustained input throughout the course of the decision formation. This sustained component was larger than the transient component during the final choice (indicated by button press). The overall amplitude of pupil dilation during decision formation was bigger before yes than no choices, irrespective of the physical presence of the target signal. Remarkably, the magnitude of this pupil choice effect (yes > no) reflected the individual criterion: it was strongest in conservative subjects choosing yes against their bias. We conclude that the central neuromodulatory systems controlling pupil size are continuously engaged during decision formation in a way that reveals how the upcoming choice relates to the decision maker’s attitude. Changes in brain state seem to interact with biased decision making in the face of uncertainty. PMID:24449874

  15. Decision-related pupil dilation reflects upcoming choice and individual bias.

    PubMed

    de Gee, Jan Willem; Knapen, Tomas; Donner, Tobias H

    2014-02-04

    A number of studies have shown that pupil size increases transiently during effortful decisions. These decision-related changes in pupil size are mediated by central neuromodulatory systems, which also influence the internal state of brain regions engaged in decision making. It has been proposed that pupil-linked neuromodulatory systems are activated by the termination of decision processes, and, consequently, that these systems primarily affect the postdecisional brain state. Here, we present pupil results that run contrary to this proposal, suggesting an important intradecisional role. We measured pupil size while subjects formed protracted decisions about the presence or absence ("yes" vs. "no") of a visual contrast signal embedded in dynamic noise. Linear systems analysis revealed that the pupil was significantly driven by a sustained input throughout the course of the decision formation. This sustained component was larger than the transient component during the final choice (indicated by button press). The overall amplitude of pupil dilation during decision formation was bigger before yes than no choices, irrespective of the physical presence of the target signal. Remarkably, the magnitude of this pupil choice effect (yes > no) reflected the individual criterion: it was strongest in conservative subjects choosing yes against their bias. We conclude that the central neuromodulatory systems controlling pupil size are continuously engaged during decision formation in a way that reveals how the upcoming choice relates to the decision maker's attitude. Changes in brain state seem to interact with biased decision making in the face of uncertainty.

  16. Dilated cardiomyopathy.

    PubMed

    Weintraub, Robert G; Semsarian, Christopher; Macdonald, Peter

    2017-02-09

    Dilated cardiomyopathy is defined by the presence of left ventricular dilatation and contractile dysfunction. Genetic mutations involving genes that encode cytoskeletal, sarcomere, and nuclear envelope proteins, among others, account for up to 35% of cases. Acquired causes include myocarditis and exposure to alcohol, drugs and toxins, and metabolic and endocrine disturbances. The most common presenting symptoms relate to congestive heart failure, but can also include circulatory collapse, arrhythmias, and thromboembolic events. Secondary neurohormonal changes contribute to reverse remodelling and ongoing myocyte damage. The prognosis is worst for individuals with the lowest ejection fractions or severe diastolic dysfunction. Treatment of chronic heart failure comprises medications that improve survival and reduce hospital admission-namely, angiotensin converting enzyme inhibitors and β blockers. Other interventions include enrolment in a multidisciplinary heart failure service, and device therapy for arrhythmia management and sudden death prevention. Patients who are refractory to medical therapy might benefit from mechanical circulatory support and heart transplantation. Treatment of preclinical disease and the potential role of stem-cell therapy are being investigated.

  17. Stress and Dilatancy Relation of Methane Hydrate Bearing Sand with Various Fines Content

    NASA Astrophysics Data System (ADS)

    Hyodo, M.

    2016-12-01

    This study presents an experimental and numerical study on the shear behaviour of methane hydrate bearing sand with variable confining pressures and methane hydrate saturations. A representative grading curve of Nankai Trough is selected as the grain size distribution of host sand to artificially produce the methane hydrate bearing sand. A shear strength estimation equation for methane hydrate bearing sand from test results is established. A simple constitutive model has been proposed to predict the stress-strain response of methane hydrate bearing sand based on a few well-known relationships. Experimental results indicate that the inclination of stress-dilatancy curve becomes steeper with a rise in methane hydrate saturation. A revised stress-dilatancy equation has been integrated with this simple model to consider the variance in the inclination of stress-dilatancy curve. The mean stress Pcr at critical state when the peak stress ratio reduces to the residual stress ratio increases with the level of methane hydrate saturation. The dilatancy parameter a tends to increase with the methane hydrate saturation. The shear deformability parameter A exhibits a decreasing tendency with the rise in methane hydrate saturation at each confining pressure. This model is capable of reasonably predicting the strength and stiffness enhancement and the dilation behaviour as methane hydrate saturation increases. The volumetric variation from contraction to expansion of MH bearing sand at a lower confining pressure and only pure volumetric contraction a higher confining pressure can be represented by this simple model.

  18. Receptive Vocabulary Knowledge in Low-Functioning Autism as Assessed by Eye Movements, Pupillary Dilation, and Event-Related Potentials

    DTIC Science & Technology

    2011-06-01

    18 W81XWH-10-1-0404 4 INTRODUCTION Approximately 50% of individuals affected by autism fail to develop useful speech , and many of...sets for these two individuals. Our autism specialist and our speech -language pathologist have also been working together to determine the best...10-1-0404 TITLE: Receptive Vocabulary Knowledge in Low-Functioning Autism as Assessed by Eye Movements, Pupillary Dilation, and Event-Related

  19. Infectious agents and inflammation in donated hearts and dilated cardiomyopathies related to cardiovascular diseases, Chagas' heart disease, primary and secondary dilated cardiomyopathies.

    PubMed

    Mangini, Sandrigo; Higuchi, Maria de Lourdes; Kawakami, Joyce Tiyeko; Reis, Marcia Martins; Ikegami, Renata Nishiyama; Palomino, Suely Aparecida Pinheiro; Pomerantzeff, Pablo Maria Alberto; Fiorelli, Alfredo Inácio; Marcondes-Braga, Fabiana Goulart; Bacal, Fernando; Ferreira, Sílvia Moreira Ayub; Issa, Victor Sarli; Souza, Germano Emílio Conceição; Chizzola, Paulo Roberto; Bocchi, Edimar Alcides

    2015-01-15

    Clinical and experimental conflicting data have questioned the relationship between infectious agents, inflammation and dilated cardiomyopathy (DCM). The aim of this study was to determine the frequency of infectious agents and inflammation in endomyocardial biopsy (EMB) specimens from patients with idiopathic DCM, explanted hearts from different etiologies, including Chagas' disease, compared to donated hearts. From 2008 to 2011, myocardial samples from 29 heart donors and 55 patients with DCMs from different etiologies were studied (32 idiopathic, 9 chagasic, 6 ischemic and 8 other specific etiologies). Inflammation was investigated by immunohistochemistry and infectious agents by immunohistochemistry, molecular biology, in situ hybridization and electron microscopy. There were no differences regarding the presence of macrophages, expression of HLA class II and ICAM-I in donors and DCM. Inflammation in Chagas' disease was predominant. By immunohistochemistry, in donors, there was a higher expression of antigens of enterovirus and Borrelia, hepatitis B and C in DCMs. By molecular biology, in all groups, the positivity was elevated to microorganisms, including co-infections, with a higher positivity to adenovirus and HHV6 in donors towards DCMs. This study was the first to demonstrate the presence of virus in the heart tissue of chagasic DCM. The presence of inflammation and infectious agents is frequent in donated hearts, in the myocardium of patients with idiopathic DCM, myocardial dysfunction related to cardiovascular diseases, and primary and secondary cardiomyopathies, including Chagas' disease. The role of co-infection in Chagas' heart disease physiopathology deserves to be investigated in future studies. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  20. Dilated cardiomyopathy secondary to rickets-related hypocalcaemia: eight case reports and a review of the literature.

    PubMed

    Yilmaz, Osman; Olgun, Hasim; Ciftel, Murat; Kilic, Omer; Kartal, Ibrahim; Iskenderoglu, Nebahat Y; Laloglu, Fuat; Ceviz, Naci

    2015-02-01

    Dilated cardiomyopathy is usually idiopathic and may arise secondary to infections or metabolic or genetic causes. Another rare cause is hypocalcaemia. Owing to the fact that calcium plays an essential role in excitation and contraction of myocardial muscle, myocardial contractility may decline in patients with hypocalcaemia. Patients with symptoms of congestive heart failure and rickets-related hypocalcaemia were assessed clinically and by echocardiography in a paediatric cardiology clinic. Echocardiography was performed for all patients. Rickets was diagnosed according to the clinical, laboratory, and radiologic findings. Maternal lifestyle and living conditions were investigated, and the maternal 25-OH vitamin D3 blood level was measured. We evaluated eight patients who developed heart failure as a result of severe hypocalcaemia associated with rickets between August, 1999 and June, 2012. The age distribution of the patients was 3-12 months. Laboratory results were consistent with advanced-stage rickets. Severe hypocalcaemia was detected in all patients. The maternal 25-OH vitamin D3 levels were low. Echocardiography revealed increased pre-treatment left ventricle end-systolic and end-diastolic diameters for age and reduced ejection fraction and fractional shortening. After clinical improvement, the patients were discharged. Severe hypocalcaemia associated with rickets must always be kept in mind among the causes of dilated cardiomyopathy and impaired cardiac function in infants. If diagnosed and treated in time, dilated cardiomyopathy and severe heart failure related to rickets respond well.

  1. The AMP-Related Kinase (AMPK) Induces Ca(2+)-Independent Dilation of Resistance Arteries by Interfering With Actin Filament Formation.

    PubMed

    Schubert, Kai Michael; Qiu, Jiehua; Blodow, Stephanie; Wiedenmann, Margarethe; Lubomirov, Lubomir T; Pfitzer, Gabriele; Pohl, Ulrich; Schneider, Holger

    2017-07-07

    Decreasing Ca(2+) sensitivity of vascular smooth muscle (VSM) allows for vasodilation without lowering of cytosolic Ca(2+). This may be particularly important in states requiring maintained dilation, such as hypoxia. AMP-related kinase (AMPK) is an important cellular energy sensor in VSM. Regulation of Ca(2+) sensitivity usually is attributed to myosin light chain phosphatase activity, but findings in non-VSM identified changes in the actin cytoskeleton. The potential role of AMPK in this setting is widely unknown. To assess the influence of AMPK on the actin cytoskeleton in VSM of resistance arteries with regard to potential Ca(2+) desensitization of VSM contractile apparatus. AMPK induced a slowly developing dilation at unchanged cytosolic Ca(2+) levels in potassium chloride-constricted intact arteries isolated from mouse mesenteric tissue. This dilation was not associated with changes in phosphorylation of myosin light chain or of myosin light chain phosphatase regulatory subunit. Using ultracentrifugation and confocal microscopy, we found that AMPK induced depolymerization of F-actin (filamentous actin). Imaging of arteries from LifeAct mice showed F-actin rarefaction in the midcellular portion of VSM. Immunoblotting revealed that this was associated with activation of the actin severing factor cofilin. Coimmunoprecipitation experiments indicated that AMPK leads to the liberation of cofilin from 14-3-3 protein. AMPK induces actin depolymerization, which reduces vascular tone and the response to vasoconstrictors. Our findings demonstrate a new role of AMPK in the control of actin cytoskeletal dynamics, potentially allowing for long-term dilation of microvessels without substantial changes in cytosolic Ca(2+). © 2017 American Heart Association, Inc.

  2. Left ventricular filling in dilated cardiomyopathy: relation to functional class and hemodynamics.

    PubMed

    Vanoverschelde, J L; Raphael, D A; Robert, A R; Cosyns, J R

    1990-05-01

    Left ventricular systolic function does not correlate well with functional class in patients with dilated cardiomyopathy. To determine whether the correlation is better with Doppler indexes of left ventricular diastolic function, 34 patients with dilated cardiomyopathy (M-mode echocardiographic end-diastolic dimension greater than 60 mm, fractional shortening less than 25%, increased E point-septal separation) were studied. Patients were classified into two groups according to functional class. Group 1 consisted of 16 patients in New York Heart Association functional class I or II; group 2 included 18 patients in functional class III or IV. Left ventricular dimensions, fractional shortening, left ventricular mass, meridional end-systolic wall stress, peak early and late transmitral filling velocities and their ratio, isovolumetric relaxation period and time to peak filling rate were computed from pulsed wave Doppler and M-mode echocardiograms and calibrated carotid pulse tracings. Right heart catheterization was performed in 20 of 34 patients. No differences were observed between groups with regard to age, gender distribution, heart rate, blood pressure and M-mode echocardiographic-derived indexes of systolic function. Peak early filling velocity (72 +/- 13 versus 40 +/- 10 cm/s, p less than 0.001) was higher and atrial filling fraction (27 +/- 4% versus 46 +/- 8%, p less than 0.001) was lower in group 2 than in group 1. The ratio of early to late transmitral filling velocities was higher in group 2 patients (2.3 +/- 0.5 versus 0.7 +/- 0.2, p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

  3. Measurement of Flow-Mediated Vasodilatation.

    PubMed

    Tomiyama, Hirofumi; Saisu, Tomoko; Yamashina, Akira

    2017-04-06

    The FMDJ study, a multicenter prospective observational study conducted in Japan, demonstrated the acceptable reliability of measurement of flow-mediated vasodilatation (FMD) using a semi-automatic device in individual institutions. However, in about 10% of Japanese subjects, adequate scans to determine the brachial arterial diameter failed to be obtained. The prevalence of inadequate scans was higher in women than in men, while obesity had no influence on the inadequate scan rate. The FMDJ study also proposed that attending periodic refresher courses on the measurement of FMD is needed for maintaining competency. Finally, the FMDJ study proposed reference values for FMD. Thus, FMD measurement may be categorized as a clinically applicable tool on the basis of class IIb (exploratory cohort study with good reference standards) evidence.

  4. An anatomic study of the tensor veli palatini and dilatator tubae muscles in relation to eustachian tube and velar function.

    PubMed

    Barsoumian, R; Kuehn, D P; Moon, J B; Canady, J W

    1998-03-01

    In a gross anatomic study of 20 sides in 16 human head specimens, the tensor veli palatini, the dilatator tubae, and the tensor tympani muscles were studied. The tensor veli palatini was observed to insert onto the anterior one-third of the pterygoid hamulus, whereas the dilatator tubae rounded the middle one-third of the pterygoid hamulus without an insertion. Thus, the dilatator tubae, not the tensor veli palatini, could serve to tense the anterior velum. An insertion from the superior pharyngeal constrictor muscle onto the posterior one-third of the hamulus could provide a curbing function for the dilatator tubae muscle. Adipose tissue, located at the hamulus, could provide lubrication for the tendinous fibers of the dilatator tubae as they round the hamulus. The dilatator tubae was observed to attach to the hook of the eustachian tube and is accepted as the tubal dilator. Observed on 13 of 20 sides in 11 specimens, the bulk of the dilatator tubae remained distinct from the tensor veli palatini despite a connective tissue alliance and intermingling of some muscle fibers. On 5 of 20 sides in 5 specimens, fibers of the dilatator tubae intermingled extensively with the tensor veli palatini. Of the 20 dilatator tubae muscles dissected, 2 were observed to be deficient. The tensor veli palatini was observed to be continuous with the tensor tympani. Full color versions of the figures are available at the following website: http://www.shc.uiowa.edu/papers/tensor/.

  5. Does altered aortic flow in marfan syndrome relate to aortic root dilatation?

    PubMed Central

    Wang, Hung‐Hsuan; Chiu, Hsin‐Hui; Tseng, Wen‐Yih Isaac

    2016-01-01

    Purpose To examine possible hemodynamic alterations in adolescent to adult Marfan syndrome (MFS) patients with aortic root dilatation. Materials and Methods Four‐dimensional flow MRI was performed in 20 MFS patients and 12 age‐matched normal subjects with a 3T system. The cross‐sectional areas of 10 planes along the aorta were segmented for calculating the axial and circumferential wall shear stress (WSSaxial, WSScirc), oscillatory shear index (OSIaxial, OSIcirc), and the nonroundness (NR), presenting the asymmetry of segmental WSS. Pearson's correlation analysis was performed to present the correlations between the quantified indices and the body surface area (BSA), aortic root diameter (ARD), and Z score of the ARD. P < 0.05 indicated statistical significance. Results Patients exhibited lower WSSaxial in the aortic root and the WSScirc in the arch (P < 0.05–0.001). MFS patients exhibited higher OSIaxial and OSIcirc in the sinotubular junction and arch, but lower OSIcirc in the descending aorta (all P < 0.05). The NR values were lower in patients (P < 0.05). The WSSaxial or WSScirc exhibited moderate to strong correlations with BSA, ARD, or Z score (R2 = 0.50–0.72) in MFS patients. Conclusion The significant differences in the quantified indices, which were associated with BSA, ARD, or Z score, in MFS were opposite to previous reports for younger MFS patients, indicating that altered flows in MFS patients may depend on the disease progress. The possible time dependency of hemodynamic alterations in MFS patients strongly suggests that longitudinal follow‐up of 4D Flow is needed to comprehend disease progress. J. Magn. Reson. Imaging 2016;44:500–508. PMID:26854646

  6. Neopterin and beta-2 microglobulin relations to immunity and inflammatory status in nonischemic dilated cardiomyopathy patients.

    PubMed

    Wojciechowska, Celina; Wodniecki, Jan; Wojnicz, Romuald; Romuk, Ewa; Jacheć, Wojciech; Tomasik, Andrzej; Skrzep-Poloczek, Bronisława; Spinczyk, Beata; Nowalany-Kozielska, Ewa

    2014-01-01

    The aim of the study was to assess the relationships among serum neopterin (NPT), β2-microglobulin (β2-M) levels, clinical status, and endomyocardial biopsy results of dilated cardiomyopathy patients (DCM). Serum NPT and β-2 M were determined in 172 nonischaemic DCM patients who underwent right ventricular endomyocardial biopsy and 30 healthy subjects (ELISA test). The cryostat biopsy specimens were assessed using histology, immunohistology, and immunochemistry methods (HLA ABC, HLA DR expression, CD3 + lymphocytes, and macrophages counts). The strong increase of HLA ABC or HLA DR expression was detected in 27.2% patients-group A-being low in 72.8% patients-group B. Neopterin level was increased in patients in group A compared to healthy controls 8.11 (4.50-12.57) versus 4.99 (2.66-8.28) nmol/L (P < 0.05). β-2 microglobulin level was higher in DCM groups A (2.60 (1.71-3.58)) and B (2.52 (1.51-3.72)) than in the control group 1.75 (1.28-1.96) mg/L, P < 0.001. Neopterin correlated positively with the number of macrophages in biopsy specimens (P < 0.05) acute phase proteins: C-reactive proteins (P < 0.05); fibrinogen (P < 0.01); and NYHA functional class (P < 0.05) and negatively with left ventricular ejection fraction (P < 0.05). Neopterin but not β-2 microglobulin concentration reflected immune response in biopsy specimens. Neopterin correlated with acute phase proteins and stage of heart failure and may indicate a general immune and inflammatory activation in heart failure.

  7. Flow-mediated dilation and exercise blood pressure in healthy adolescents

    USDA-ARS?s Scientific Manuscript database

    Objectives: Atherosclerosis is a process that begins in youth. The endothelium plays an essential role in regulating blood flow and protecting against progression of the initial stages of the atherosclerotic process. Few studies have investigated the relationship between aerobic fitness and exerc...

  8. Functional networks of nucleocytoplasmic transport-related genes differentiate ischemic and dilated cardiomyopathies. A new therapeutic opportunity.

    PubMed

    Molina-Navarro, María Micaela; Triviño, Juan Carlos; Martínez-Dolz, Luis; Lago, Francisca; González-Juanatey, Jose Ramón; Portolés, Manuel; Rivera, Miguel

    2014-01-01

    Heart failure provokes alterations in the expression of nucleocytoplasmic transport-related genes. To elucidate the nucleocytoplasmic transport-linked functional network underlying the two major causes of heart failure, ischemic cardiomyopathy (ICM) and dilated cardiomyopathy (DCM), we examined global transcriptome profiles of left ventricular myocardium tissue samples from 31 patients (ICM, n = 10; DCM, n = 13) undergoing heart transplantation and control donors (CNT, n = 8) using RNA-Sequencing and GeneMANIA. Comparative profiling of ICM versus control and DCM versus control showed 1081 and 2440 differentially expressed genes, respectively (>1.29-fold; P<0.05). GeneMANIA revealed differentially regulated functional networks specific to ICM and DCM. In comparison with CNT, differential expression was seen in 9 and 12 nucleocytoplasmic transport-related genes in ICM and DCM groups, respectively. DDX3X, KPNA2, and PTK2B were related to ICM, while SMURF2, NUP153, IPO5, RANBP3, NOXA1, and RHOJ were involved in DCM pathogenesis. Furthermore, the two pathologies shared 6 altered genes: XPO1, ARL4, NFKB2, FHL3, RANBP2, and RHOU showing an identical trend in expression in both ICM and DCM. Notably, the core of the derived functional networks composed of nucleocytoplasmic transport-related genes (XPO1, RANBP2, NUP153, IPO5, KPNA2, and RANBP3) branched into several pathways with downregulated genes. Moreover, we identified genes whose expression levels correlated with left ventricular mass index and left ventricular function parameters in HF patients. Collectively, our study provides a clear distinction between the two pathologies at the transcriptome level and opens up new possibilities to search for appropriate therapeutic targets for ICM and DCM.

  9. Microstructural formulation of stress dilatancy

    NASA Astrophysics Data System (ADS)

    Wan, Richard; Guo, Peijun

    2014-03-01

    In this work, we show that the well-known Rowe's stress-dilatancy relation can be readily recovered from a micromechanical analysis of an assembly of rigid particles as a purely dissipative system in the case of a regular packing. When the analysis is extended to a random packing, one can explicitly incorporate the dependence of fabric, density and stress level on dilatancy, a basic aspect of geomaterial behaviour. The resulting microstructurally based stress dilatancy relation can be easily implemented as a non-associated flow rule in any standard elastoplastic model. Some numerical simulations of stress-dilatancy with initial fabric as a controlling variable are presented to illustrate the developed model. xml:lang="fr"

  10. Assessment of pain after elective abortion relating to the use of misoprostol for dilatation of the cervix.

    PubMed

    Gagné, Alexandra; Guilbert, Edith; Ouellet, Jacinthe; Roy, Valérie; Tremblay, Jean-Guy

    2010-03-01

    Our objective was to compare the use of misoprostol to that of laminaria tents for dilatation of the cervix before a surgical elective abortion (EAB) during the first trimester, with regard to the pain caused (1) during insertion, for both methods, (2) immediately before the EAB, and (3) one hour after the procedure. One hundred two women were recruited at Clinique de planification des naissances du Centre hospitalier universitaire de Québec, CHUL pavilion, between March 1, 2006 and March 1, 2007, for a tracking study. Fifty-three women were given 400 microg of misoprostol intravaginally, three to four hours before the EAB, and a laminaria tent was inserted in 49 women, 16 to 24 hours before the EAB. A visual analog scale was used to determine the pain score. One hour after EAB, severe pain was reported in 6% of the participants who were given misoprostol. The pain score post-EAB was 3.8 times higher in women who were given misoprostol than in those who had a laminaria tent inserted (P = 0.004). The pain score during insertion of the dilatation method was 33 times higher with the laminaria tent than with misoprostol (P < 0. 001), and 30% of women who had a laminaria tent inserted felt severe pain. While misoprostol may increase pain after EAB in a small percentage of women, it remains an efficient, easy to use, low-cost method for dilating the cervix before an EAB. It is one of the options that may be offered to women when a pre-EAB dilatation of the cervix is required, after discussing its benefits and disadvantages with them.

  11. Regulation of vascular tone and pulse wave velocity in human muscular conduit arteries: selective effects of nitric oxide donors to dilate muscular arteries relative to resistance vessels.

    PubMed

    Fok, Henry; Jiang, Benyu; Clapp, Brian; Chowienczyk, Phil

    2012-11-01

    Arterial tone in muscular conduit arteries may influence pressure wave reflection through changes in diameter and pulse wave velocity. We examined the relative specificity of vasodilator drugs for radial artery and forearm resistance vessels during intrabrachial arterial infusion. The nitric oxide (NO) donors, nitroglycerine and nitroprusside, and brain natriuretic peptide were compared with the α-adrenergic antagonist phentolamine, calcium-channel antagonist verapamil, and hydralazine. Radial artery diameter was measured by high resolution ultrasound, forearm blood flow by strain gauge plethysmography, and pulse wave velocity by pressure recording cuffs placed over the distal brachial and radial arteries. Norepinephrine was used to constrict the radial artery to generate a greater range of vasodilator tone when examining pulse wave velocity. Despite dilating resistance vasculature, phentolamine and verapamil had little effect on radial artery diameter (mean dilation <9%). By contrast, for comparable actions on resistance vessels, nitroglycerine and nitroprusside but not brain natriuretic peptide had powerful actions to dilate the radial artery (dilations of 31.3 ± 3.6%, 23.6 ± 3.1%, and 9.8 ± 2.0% for nitroglycerine, nitroprusside, and brain natriuretic peptide, respectively). Changes in pulse wave velocity followed those in arterial diameter irrespective of the signaling pathway used to modulate arterial tone (R=-0.89, P<0.05). Basal tone in human muscular arteries is relatively unaffected by α-adrenergic or calcium-channel blockade, but is functionally or directly antagonized by NO donors. The differential response to NO donors suggests that there is potential to manipulate the downstream pathway to confer greater specificity for large arteries with a resultant decrease in pressure wave reflection and systolic blood pressure.

  12. Dilating Eye Drops

    MedlinePlus

    ... sometimes used to treat eye diseases, such as amblyopia and inflammation. How long do dilating drops last? ... used to treat certain eye diseases, such as amblyopia and inflammation in the eye. These therapeutic dilating ...

  13. Endothelial dysfunction in normoglycaemic first-degree relatives of type 2 diabetes mellitus complicated with hyperuricaemia.

    PubMed

    Zhang, Junxia; Xiang, Lin; Zhang, Bilin; Cheng, Yangyang

    2017-03-01

    To reveal the effect of hyperuricaemia on endothelial function in normoglycaemic first-degree relatives of type 2 diabetes mellitus. In all, 40 first-degree relatives of type 2 diabetes mellitus with hyperuricaemia, 40 first-degree relatives of type 2 diabetes mellitus with normouricaemia and 35 healthy subjects without diabetic family history were recruited in this study. Anthropometric parameters as well as blood pressure, blood lipids, fasting blood glucose, fasting insulin, C-reactive protein, tumour necrosis factor-α and interleukin-6 were measured. Insulin resistance was assessed with homoeostasis model assessment index-insulin resistance index. To assess endothelial function, high-resolution ultrasonography was used for measuring flow- and nitroglycerine-mediated brachial artery vasodilation. When compared with control, flow-mediated dilation was lower in first-degree relatives with or without hyperuricaemia (both p < 0.001). When compared with first-degree relative subjects with normouricaemia, there were lower flow-mediated dilation ( p < 0.001) and higher levels of uric acid ( p < 0.001), fasting blood glucose ( p < 0.001), C-reactive protein ( p = 0.001), tumour necrosis factor-α ( p < 0.001) and interleukin-6 ( p < 0.001) in first-degree relative subjects with hyperuricaemia. Flow-mediated dilation was found to be negatively related to uric acid ( r = -0.597, p < 0.001). Stepwise multiple regressions demonstrated that uric acid was a significant determinant of flow-mediated dilation independent of other variables in first-degree relatives of type 2 diabetes mellitus (β = -0.677, p < 0.001; confidence interval: -0.010 to -0.006). Further endothelial dysfunction is found in normoglycaemic first-degree relatives of type 2 diabetes mellitus complicated with hyperuricaemia.

  14. VAP-1 blockade prevents subarachnoid hemorrhage-associated cerebrovascular dilating dysfunction via repression of a neutrophil recruitment-related mechanism.

    PubMed

    Xu, Haoliang; Testai, Fernando D; Valyi-Nagy, Tibor; N Pavuluri, Mani; Zhai, Fengguo; Nanegrungsunk, Danop; Paisansathan, Chanannait; Pelligrino, Dale A

    2015-04-07

    Our previous findings indicated that in rats subjected to subarachnoid hemorrhage (SAH), suppression of post-SAH neuroinflammation via vascular adhesion protein-1 (VAP-1) blockade provides significant neuroprotection. We and others have reported that neuroinflammation contributes to cerebral microvascular impairment. Thus, in the present study, we tested the hypotheses that: (1) treatment with LJP-1586, a selective VAP-1 blocker, prevents SAH-associated pial arteriolar dilating dysfunction; and (2) the vasculoprotective effect of LJP-1586 arises from inhibiting SAH-elicited neutrophil recruitment. We utilized an endovascular perforation model of SAH. Rats subjected to SAH were either treated with LJP-1586 or rendered neutropenic via anti-neutrophil-antibody treatment. Findings from these groups were compared to their respective control groups. At 48 h post-SAH, rats were evaluated for neurobehavioral function, pial venular leukocyte trafficking, and pial arteriolar reactivity to topically-applied acetylcholine (ACh) and S-nitroso-N-acetyl penicillamine (SNAP). Pial arteriolar responses decreased at 48 h post-SAH. However, in the presence of LJP-1586, those responses were significantly preserved. Neutrophil-depletion yielded a substantial suppression of SAH-associated leukocyte adhesion and infiltration. This was accompanied by a significant preservation of pial arteriolar dilating function, suggesting a direct link between neutrophil recruitment and the loss of cerebral microvascular reactivity. Moreover, neutrophil depletion also was associated with significant protection of neurobehavioral function. The present findings suggest that attenuating SAH-linked elevation in neutrophil trafficking will protect against the development of microvascular dysfunction and subsequent neurological impairment.

  15. Bootstrapping Time Dilation Decoherence

    NASA Astrophysics Data System (ADS)

    Gooding, Cisco; Unruh, William G.

    2015-10-01

    We present a general relativistic model of a spherical shell of matter with a perfect fluid on its surface coupled to an internal oscillator, which generalizes a model recently introduced by the authors to construct a self-gravitating interferometer (Gooding and Unruh in Phys Rev D 90:044071, 2014). The internal oscillator evolution is defined with respect to the local proper time of the shell, allowing the oscillator to serve as a local clock that ticks differently depending on the shell's position and momentum. A Hamiltonian reduction is performed on the system, and an approximate quantum description is given to the reduced phase space. If we focus only on the external dynamics, we must trace out the clock degree of freedom, and this results in a form of intrinsic decoherence that shares some features with a proposed "universal" decoherence mechanism attributed to gravitational time dilation (Pikovski et al in Nat Phys, 2015). We note that the proposed decoherence remains present in the (gravity-free) limit of flat spacetime, emphasizing that the effect can be attributed entirely to proper time differences, and thus is not necessarily related to gravity. Whereas the effect described in (Pikovski et al in Nat Phys, 2015) vanishes in the absence of an external gravitational field, our approach bootstraps the gravitational contribution to the time dilation decoherence by including self-interaction, yielding a fundamentally gravitational intrinsic decoherence effect.

  16. Neonatal dilated cardiomyopathy.

    PubMed

    Soares, Paulo; Rocha, Gustavo; Pissarra, Susana; Soares, Henrique; Flôr-de-Lima, Filipa; Costa, Sandra; Moura, Cláudia; Dória, Sofia; Guimarães, Hercília

    2017-03-01

    Cardiomyopathies are rare diseases of the heart muscle, of multiple causes, that manifest with various structural and functional phenotypes but are invariably associated with cardiac dysfunction. Dilated cardiomyopathy is the commonest cardiomyopathy in children, and the majority present before one year of age. Its etiology may be acquired or genetic. Myocarditis is an important cause and is responsible for the majority of acquired cases. Inherited (familial) forms of dilated cardiomyopathy may occur in 25-50% of patients. Echocardiographic and tissue Doppler studies are the basis for diagnosis of dilated cardiomyopathy in most patients. Marked dilatation of the left ventricle with global hypokinesis is the hallmark of the disease. This review will cover the classification, epidemiology and management of newborns with dilated cardiomyopathy. In particular, a comprehensive and up-to-date review of the genetic study of dilated cardiomyopathy and of detailed echocardiographic assessment of these patients will be presented.

  17. Note: Flow mediated skin fluorescence—A novel technique for evaluation of cutaneous microcirculation

    NASA Astrophysics Data System (ADS)

    Piotrowski, L.; Urbaniak, M.; Jedrzejczak, B.; Marcinek, A.; Gebicki, J.

    2016-03-01

    This note describes a newly developed technique for evaluation of cutaneous microcirculation. The technique called Flow Mediated Skin Fluorescence (FMSF) is based on monitoring of NADH fluorescence intensity emitted from the skin tissue cells of a forearm. The changes in fluorescence intensity as a function of time in response to blocking and releasing of blood flow in a forearm are used as a measure of oxygen transport with blood to the tissue, which directly correlates with the skin microcirculation status. Preliminary results collected for healthy volunteers and patients experiencing serious cardiovascular problems indicated a usefulness of FMSF technique for evaluation of health related perturbations in cutaneous microcirculation.

  18. Note: Flow mediated skin fluorescence--A novel technique for evaluation of cutaneous microcirculation.

    PubMed

    Piotrowski, L; Urbaniak, M; Jedrzejczak, B; Marcinek, A; Gebicki, J

    2016-03-01

    This note describes a newly developed technique for evaluation of cutaneous microcirculation. The technique called Flow Mediated Skin Fluorescence (FMSF) is based on monitoring of NADH fluorescence intensity emitted from the skin tissue cells of a forearm. The changes in fluorescence intensity as a function of time in response to blocking and releasing of blood flow in a forearm are used as a measure of oxygen transport with blood to the tissue, which directly correlates with the skin microcirculation status. Preliminary results collected for healthy volunteers and patients experiencing serious cardiovascular problems indicated a usefulness of FMSF technique for evaluation of health related perturbations in cutaneous microcirculation.

  19. Patterns of Mechanical Inefficiency in Pediatric Dilated Cardiomyopathy and Their Relation to Left Ventricular Function and Clinical Outcomes.

    PubMed

    Forsha, Daniel; Slorach, Cameron; Chen, Ching Kit; Sherman, Ashley; Mertens, Luc; Barker, Piers; Kisslo, Joseph; Friedberg, Mark K

    2016-03-01

    Pediatric dilated cardiomyopathy (DCM) is associated with death or transplantation and is typically considered a homogeneous process affecting global left ventricular (LV) function. However, assessment of regional abnormalities that contribute to pumping inefficiencies is lacking. The aim of this study was to define regional strain patterns of mechanical inefficiency in the broader context of LV discoordination (dysfunction and timing abnormalities) and to evaluate their associations with LV function and clinical outcomes. Multiplanar apical LV echocardiographic images from patients with pediatric DCM (n = 56) and control subjects (n = 20) were analyzed by two-dimensional longitudinal speckle-tracking strain analysis to identify segmental strain patterns and global contraction groups. Clinical outcome (death or transplantation vs transplantation-free survival) and echocardiographic data were evaluated. Outcome groups were compared using the Fisher exact test, the χ(2) test, or analysis of variance (with P values ≤ .05 considered to indicate statistical significance). Of 56 patients with DCM, 29 (52%) progressed to death or transplantation. Five segmental strain patterns were observed that were used to define seven contraction groups by regional contractility and/or timing discoordination. The group(s) with the most discoordination had the most LV dysfunction (P = .0004) and a trend toward the highest frequency of death or transplantation (P = .069). Interreader reproducibility of segmental strain patterns agreed in 165 or 180 (92%) segments tested (κ = 0.90). Control subjects had normal strain patterns. A heterogeneous mixture of abnormalities in the regional wall mechanics that lead to inefficient pump mechanics through functional and timing abnormalities were seen in this cohort and were categorized into natural subgroups. More severe LV discoordination was associated with increased LV dysfunction and a trend toward death or transplantation

  20. Parent reports of health-related quality of life and heart failure severity score independently predict outcome in children with dilated cardiomyopathy.

    PubMed

    den Boer, Susanna L; Baart, Sara J; van der Meulen, Marijke H; van Iperen, Gabriëlle G; Backx, Ad P; Ten Harkel, Arend D; Rammeloo, Lukas A; du Marchie Sarvaas, Gideon J; Tanke, Ronald B; Helbing, Willem A; Utens, Elisabeth M; Dalinghaus, Michiel

    2017-08-01

    Dilated cardiomyopathy in children causes heart failure and has a poor prognosis. Health-related quality of life in this patient group is unknown. Moreover, results may provide detailed information of parents' sense of their child's functioning. We hypothesised that health-related quality of life, as rated by parents, and the paediatric heart failure score, as assessed by physicians, have both predictive value on outcome. Methods and results In this prospective study, health-related quality of life was assessed by parent reports: the Infant Toddler Quality of Life questionnaire (0-4 years) or Child Health Questionnaire-Parent Form 50 (4-18 years) at 3-6-month intervals. We included 90 children (median age 3.8 years, interquartile range (IQR) 0.9-12.3) whose parents completed 515 questionnaires. At the same visit, physicians completed the New York University Pediatric Heart Failure Index. Compared with Dutch normative data, quality of life was severely impaired at diagnosis (0-4 years: 7/10 subscales and 4-18 years: 8/11 subscales) and ⩾1 year after diagnosis (3/10 and 6/11 subscales). Older children were more impaired (p<0.05). After a median follow-up of 3 years (IQR 2-4), 15 patients underwent transplantation. Using multivariable time-dependent Cox regression, "physical functioning" subscale and the Heart Failure Index were independently predictive of the risk of death and heart transplantation (hazard ratio 1.24 per 10% decrease of predicted, 95% confidence interval (CI) 1.06-1.47 and hazard ratio 1.38 per unit, 95% CI 1.19-1.61, respectively). Physical impairment rated by parents and heart failure severity assessed by physicians independently predicted the risk of death or heart transplantation in children with dilated cardiomyopathy.

  1. Sinuplasty (Balloon Catheter Dilation)

    MedlinePlus

    ... development of the balloon dilating catheter and its adaptation to sinus surgery. In the 1980s, the field ... used in endoscopic sinus surgery. It is the adaptation or application of minimally-invasive balloon technology to ...

  2. Inflammatory dilated cardiomyopathy (DCMI).

    PubMed

    Maisch, Bernhard; Richter, Anette; Sandmöller, Andrea; Portig, Irene; Pankuweit, Sabine

    2005-09-01

    Cardiomyopathies are heart muscle diseases, which have been defined by their central hemodynamics and macropathology and divided in five major forms: dilated (DCM), hypertrophic (HCM), restrictive (RCM), right ventricular (RVCM), and nonclassifiable cardiomyopathies (NCCM). Furthermore, the most recent WHO/WHF definition also comprises, among the specific cardiomyopathies, inflammatory cardiomyopathy as a distinct entity, defined as myocarditis in association with cardiac dysfunction. Idiopathic, autoimmune, and infectious forms of inflammatory cardiomyopathy were recognized. Viral cardiomyopathy has been defined as viral persistence in a dilated heart. It may be accompanied by myocardial inflammation and then termed inflammatory viral cardiomyopathy (or viral myocarditis with cardiomegaly). If no inflammation is observed in the biopsy of a dilated heart (< 14 lymphocytes and macrophages/mm(2)), the term viral cardiomyopathy or viral persistence in DCM should be applied according to the WHF Task Force recommendations. Within the German heart failure net it is the authors' working hypothesis, that DCM shares genetic risk factors with other diseases of presumed autoimmune etiology and, therefore, the same multiple genes in combination with environmental factors lead to numerous different autoimmune diseases including DCM. Therefore, the authors' primary goal is to acquire epidemiologic data of patients with DCM regarding an infectious and inflammatory etiology of the disease. Circumstantial evidence points to a major role of viral myocarditis in the etiology of DCM. The common presence of viral genetic material in the myocardium of patients with DCM provides the most compelling evidence, but proof of causality is still lacking. In addition, autoimmune reactions have been described in many studies, indicating them as an important etiologic factor. Nevertheless, data on the proportion of patients, in whom both mechanisms play a role are still missing.A pivotal role for

  3. Flow-Mediated Change in Viscoelastic Property of Radial Arterial Wall Measured by 22 MHz Ultrasound

    NASA Astrophysics Data System (ADS)

    Ikeshita, Kazuki; Hasegawa, Hideyuki; Kanai, Hiroshi

    2009-07-01

    The endothelial dysfunction is considered to be an initial step in atherosclerosis. Additionally, it was reported that the smooth muscle, which constructs the media of the artery, changes its characteristics owing to atherosclerosis. Therefore, it is essential to develop a method of assessing the regional endothelial function and mechanical properties of the arterial wall. To evaluate the endothelial function, a conventional technique of measuring the transient change in the diameter of the brachial artery caused by flow-mediated dilation (FMD) after the release of avascularization is used. However, this method can not evaluate the mechanical properties of the wall. We previously developed a method for the simultaneous measurements of waveforms of radial strain and blood pressure in the radial artery. In this study, the viscoelasticity of the arterial wall was estimated from the measured stress-strain relationship using the least-squares method and the transient changes in the mechanical properties of the arterial wall ware revealed. From in vivo experimental results, the stress-strain relationship showed a hysteresis loop and viscoelasticity was estimated by the proposed method. The slope of the loop decreased owing to FMD, which resulted in the decrease in estimated elastic modulus. The increase in the area of the loop occurred after recirculation, which corresponds to the increase in the ratio of the loss modulus (depends on viscosity) to the elastic modulus when the Voigt model is assumed. In this study, the variance in estimates was evaluated by in vivo measurement for 10 min. The temporal decrease in static elasticity after recirculation due to FMD was much larger than the evaluated variance. These results show a potential of the proposed method for the thorough analysis of the transient change in viscoelasticity due to FMD.

  4. Receptive Vocabulary Knowledge in Low Functioning Autism as Assessed by Eye Movements, Pupillary Dilation, and Event Related Potentials

    DTIC Science & Technology

    2014-06-01

    important in educational, therapeutic, and other clinical settings in which individuals with autism are taught new words. What was the impact on...language assessment using event-related potentials: Development of a clinical protocol. Developmental Medicine and Child Neurology, 41, 740–747. Colombo, J...Connolly, J. F. (2003). Electrophysiological assess- ment of language function following stroke. Clinical Neurophysiology, 114, 662–672. Dahan, D

  5. Recovery of Flow-Mediated Vasodilatation after Repetitive Measurements Is Involved in Early Vascular Impairment: Comparison with Indices of Vascular Tone

    PubMed Central

    Inaba, Hatsumi; Takeshita, Kyosuke; Uchida, Yasuhiro; Hayashi, Motoharu; Okumura, Takahiro; Hirashiki, Akihiro; Yoshikawa, Daiji; Ishii, Hideki; Yamamoto, Koji; Nakayama, Takayuki; Hirayama, Masaaki; Matsumoto, Hiroyuki; Matsushita, Tadashi; Murohara, Toyoaki

    2014-01-01

    In repetitive measurements of flow-mediated dilatation (FMD), the duration of the interval between measurements remains controversial. In this pilot study, we conducted three sequential measurements of low–flow-mediated constriction (L-FMC), FMD and flow-mediated total dilation (FMTD; L-FMC+ FMD) at baseline and intervals of 15 and 60 min in 30 healthy males. FMD15, L-FMC15, and FMTD15 were significantly lower than the respective first measurements, but all indices showed full recovery at 60 min in all subjects. The baseline diameter was slightly increased at 15 min and restored at 60 min, but the maximum diameter, and the baseline and reactive flow velocity unchanged. We examined the relationship between recovery rate of FMTD at 15 min (FMTD-R) and cardio-ankle vascular index (CAVI). Univariate analysis showed moderate correlation between FMTD-R, and CAVI and L-FMC0. Patients were divided according to FMTD-R value; the low-FMTD-R group [below the median value (−26.2%)] included a significantly higher proportion of smokers and higher CAVI values than the high-FMTD-R group. The reproducibility of FMTD and FMTD-R was evaluated in another group of 25 healthy subjects. The range of variation across measurements was 1.1% for FMTD and 4.6% for FMTD-R; with intraclass correlation coefficients of 0.93 and 0.95, respectively. The present study demonstrated blunted recovery of FMD within 15 min, suggesting the need for selection of a more adequate interval between measurements to avoid underestimation of FMD in subsequent measurements. The findings demonstrated the reproducibility of FMTD-R and FMTD measurements, and that FMTD-R might be involved in arterial stiffness and early vascular impairment in the healthy subjects. PMID:24392103

  6. Acute limb heating improves macro- and microvascular dilator function in the leg of aged humans.

    PubMed

    Romero, Steven A; Gagnon, Daniel; Adams, Amy N; Cramer, Matthew N; Kouda, Ken; Crandall, Craig G

    2017-01-01

    Local heating of an extremity increases blood flow and vascular shear stress throughout the arterial tree. Local heating acutely improves macrovascular dilator function in the upper limbs of young healthy adults through a shear stress-dependent mechanism but has no such effect in the lower limbs of this age group. The effect of acute limb heating on dilator function within the atherosclerotic prone vasculature of the lower limbs of aged adults is unknown. Therefore, the purpose of this study was to test the hypothesis that acute lower limb heating improves macro- and microvascular dilator function within the leg vasculature of aged adults. Nine young and nine aged adults immersed their lower limbs at a depth of ~33 cm into a heated (~42°C) circulated water bath for 45 min. Before and 30 min after heating, macro (flow-mediated dilation)- and microvascular (reactive hyperemia) dilator functions were assessed in the lower limb, following 5 min of arterial occlusion, via Doppler ultrasound. Compared with preheat, macrovascular dilator function was unchanged following heating in young adults (P = 0.6) but was improved in aged adults (P = 0.04). Similarly, microvascular dilator function, as assessed by peak reactive hyperemia, was unchanged following heating in young adults (P = 0.1) but was improved in aged adults (P < 0.01). Taken together, these data suggest that acute lower limb heating improves both macro- and microvascular dilator function in an age dependent manner.

  7. Activated nuclear transcription factor {kappa}B in patients with myocarditis and dilated cardiomyopathy-relation to inflammation and cardiac function

    SciTech Connect

    Alter, Peter . E-mail: palter@med.uni-marburg.de; Rupp, Heinz; Maisch, Bernhard

    2006-01-06

    Objectives and background: Myocarditis is caused by various agents and autoimmune processes. It is unknown whether viral genome persistence represents inactive remnants of previous infections or whether it is attributed to ongoing adverse processes. The latter also applies to the course of autoimmune myocarditis. One principal candidate for an adverse remodeling is nuclear factor-{kappa}B (NF{kappa}B). Methods: A total of 93 patients with suspected myocarditis/cardiomyopathy was examined. Hemodynamics were assessed by echocardiography as well as right and left heart catheterization. Endomyocardial biopsies were taken from the left ventricle. Biopsies were examined by immunohistochemistry and PCR for viral genomes. Selective immunostaining of activated NF{kappa}B was performed. Results: NF{kappa}B was increased in patients with myocarditis when compared with controls (11.1 {+-} 7.1% vs. 5.0 {+-} 5.3%, P < 0.005) whereas dilated cardiomyopathy showed no significant increase. Patients with myocarditis and preserved left ventricular function exhibited increased activated NF{kappa}B when compared with reduced function (r {sup 2} = 0.72, P < 0.001). In parallel, inverse correlation of NF{kappa}B and left ventricular enddiasstolic volume was found (r {sup 2} = 0.43, P < 0.02). Increased activated NF{kappa}B was found in adenovirus persistence when compared with controls (P = 0.001). Only a trend of increased NF{kappa}B activation was seen in cytomegalovirus persistence. Parvovirus B19 persistence did not affect NF{kappa}B activation. Conclusions: Increased activation of NF{kappa}B is related to inflammatory processes in myocarditis. Since activated NF{kappa}B correlates with left ventricular function, it could be assumed that NF{kappa}B activation occurs at early stages of inflammation. Potentially, NF{kappa}B could inhibit loss of cardiomyocytes by apoptosis and protect from cardiac dilation. Since NF{kappa}B is a crucial key transcription factor of inflammation, its

  8. The pathogenesis of proventricular dilatation disease.

    PubMed

    Tizard, Ian; Shivaprasad, H L; Guo, Jianhua; Hameed, Samer; Ball, Judith; Payne, Susan

    2016-12-01

    Bornaviruses cause neurologic diseases in several species of birds, especially parrots, waterfowl and finches. The characteristic lesions observed in these birds include encephalitis and gross dilatation of the anterior stomach - the proventriculus. The disease is thus known as proventricular dilatation disease (PDD). PDD is characterized by extreme proventricular dilatation, blockage of the passage of digesta and consequent death by starvation. There are few clinical resemblances between this and the bornaviral encephalitides observed in mammals. Nevertheless, there are common virus-induced pathogenic pathways shared across this disease spectrum that are explored in this review. Additionally, a review of the literature relating to gastroparesis in humans and the control of gastric mobility in mammals and birds points to several plausible mechanisms by which bornaviral infection may result in extreme proventricular dilatation.

  9. Genetics of hypertrophic and dilated cardiomyopathy.

    PubMed

    Friedrich, Felix W; Carrier, Lucie

    2012-10-01

    Cardiomyopathies are categorized as extrinsic, being caused by external factors, such as hypertension, ischemia, inflammation, valvular dysfunction, or as intrinsic, which correspond to myocardial diseases without identifiable external causes. These so called primary cardiomyopathies can be categorized in four main forms: hypertrophic, dilated, restrictive, and arrhythmogenic right ventricular cardiomyopathy. Cardiomyopathies are diagnosed by clinical expression, echocardiography, electrocardiography, non-invasive imaging, and sometimes by cardiac catheterization to rule out external causes as ischemia. The two main forms of primary cardiomyopathies are the hypertrophic and dilated cardiomyopathies. Most of hypertrophic cardiomyopathy and 20-50% of dilated cardiomyopathy are familial showing a wide genetic and phenotypic heterogeneity. This review presents the current knowledge on the causative genes, molecular mechanisms and the genotype � phenotype relations of hypertrophic and dilated cardiomyopathies.

  10. Early Progressive Dilated Cardiomyopathy in a Family with Becker Muscular Dystrophy Related to a Novel Frameshift Mutation in the Dystrophin Gene Exon 27

    PubMed Central

    Tsuda, Takeshi; Fitzgerald, Kristi; Scavena, Mena; Gidding, Samuel; Cox, Mary O.; Marks, Harold; Flanigan, Kevin M.; Moore, Steven A.

    2014-01-01

    We report a family in which two male siblings with Becker muscular dystrophy (BMD) developed severe dilated cardiomyopathy (DCM) and progressive heart failure (HF) at age 11; one died at age 14 years while awaiting heart transplant and the other underwent left ventricular assist device (LVAD) implantation at the same age. Genetic analysis of one sibling showed a novel frameshift mutation in exon 27 of Duchenne muscular dystrophy (DMD) gene (c.3779_3785delCTTTGGAins GG), in which 7 base pairs are deleted and two are inserted. While this predicts an amino acid substitution and premature termination (p.Thr1260Argfs*8), muscle biopsy dystrophin immunostaining instead indicates that the mutation is more likely to alter splicing. Despite relatively preserved skeletal muscular performance, both siblings developed progressive heart failure secondary to early onset DCM. In addition, their 7 year old nephew with delayed gross motor development, mild proximal muscle weakness, and markedly elevated serum creatine kinase (CK) level (> 13,000 IU/L) at 16 months was recently demonstrated to have the familial DMD mutation. Here we report a novel genotype of BMD with early onset DCM and progressive lethal heart failure during early adolescence. PMID:25537791

  11. Early-progressive dilated cardiomyopathy in a family with Becker muscular dystrophy related to a novel frameshift mutation in the dystrophin gene exon 27.

    PubMed

    Tsuda, Takeshi; Fitzgerald, Kristi; Scavena, Mena; Gidding, Samuel; Cox, Mary O; Marks, Harold; Flanigan, Kevin M; Moore, Steven A

    2015-03-01

    We report a family in which two male siblings with Becker muscular dystrophy (BMD) developed severe dilated cardiomyopathy (DCM) and progressive heart failure (HF) at age 11 years; one died at age 14 years while awaiting heart transplant and the other underwent left ventricular assist device implantation at the same age. Genetic analysis of one sibling showed a novel frameshift mutation in exon 27 of Duchenne muscular dystrophy (DMD) gene (c.3779_3785delCTTTGGAinsGG), in which seven base pairs are deleted and two are inserted. Although this predicts an amino-acid substitution and premature termination (p.Thr1260Argfs*8), muscle biopsy dystrophin immunostaining instead indicates that the mutation is more likely to alter splicing. Despite relatively preserved skeletal muscular performance, both the siblings developed progressive HF secondary to early-onset DCM. In addition, their 7-year-old nephew with delayed gross motor development, mild proximal muscle weakness and markedly elevated serum creatine kinase level (>13 000 IU l(-1)) at 16 months was recently demonstrated to have the familial DMD mutation. Here, we report a novel genotype of BMD with early-onset DCM and progressive lethal HF during early adolescence.

  12. Parallel decrease in arterial distensibility and in endothelium-dependent dilatation in young women with a history of pre-eclampsia.

    PubMed

    Pàez, Olga; Alfie, José; Gorosito, Marta; Puleio, Pablo; de Maria, Marcelo; Prieto, Noemì; Majul, Claudio

    2009-10-01

    Pre-eclampsia not only complicates 5 to 8% of pregnancies but also increases the risk of maternal cardiovascular disease and mortality later in life. We analyzed three different aspects of arterial function (pulse wave velocity, augmentation index, and flow-mediated dilatation), in 55 nonpregnant, normotensive women (18-33 years old) according to their gestational history: 15 nulliparous, 20 with a previous normotensive, and 20 formerly pre-eclamptic pregnancy. Former pre-eclamptic women showed a significantly higher augmentation index and pulse wave velocity (P < 0.001 and P < 0.05, respectively) and lower flow-mediated dilatation (p = 0.01) compared to control groups. In contrast, sublingual nitroglycerine elicited a comparable vasodilatory response in the three groups. The augmentation index correlated significantly with pulse wave velocity and flow-mediated dilatation (R = 0.28 and R = -0.32, respectively, P < 0.05 for both). No significant correlations were observed between augmentation index or flow-mediated dilatation with age, body mass index (BMI), brachial blood pressure, heart rate, or metabolic parameters (plasma cholesterol, glucose, insulin, or insulin resistance). Birth weight maintained a significantly inverse correlation with the augmentation index (R = -0.51, p < 0.002) but not with flow-mediated dilatation. Our findings revealed a parallel decrease in arterial distensibility and endothelium-dependent dilatation in women with a history of pre-eclampsia compared to nulliparous women and women with a previous normal pregnancy. A high augmentation index was the most consistent alteration associated with a history of pre-eclampsia. The study supports the current view that the generalized arterial dysfunction associated with pre-eclampsia persists subclinically after delivery.

  13. Mitochondrial-related gene expression profiles suggest an important role of PGC-1alpha in the compensatory mechanism of endemic dilated cardiomyopathy

    SciTech Connect

    He, Shu-Lan; Tan, Wu-Hong; Zhang, Zeng-Tie; Zhang, Feng; Qu, Cheng-Juan; Lei, Yan-Xia; Zhu, Yan-He; Yu, Han-Jie; Xiang, You-Zhang; and others

    2013-10-15

    Keshan disease (KD) is an endemic dilated cardiomyopathy with unclear etiology. In this study, we compared mitochondrial-related gene expression profiles of peripheral blood mononuclear cells (PBMCs) derived from 16 KD patients and 16 normal controls in KD areas. Total RNA was isolated, amplified, labeled and hybridized to Agilent human 4×44k whole genome microarrays. Mitochondrial-related genes were screened out by the Third-Generation Human Mitochondria-Focused cDNA Microarray (hMitChip3). Quantitative real-time PCR, immunohistochemical and biochemical parameters related mitochondrial metabolism were conducted to validate our microarray results. In KD samples, 34 up-regulated genes (ratios≥2.0) were detected by significance analysis of microarrays and ingenuity systems pathway analysis (IPA). The highest ranked molecular and cellular functions of the differentially regulated genes were closely related to amino acid metabolism, free radical scavenging, carbohydrate metabolism, and energy production. Using IPA, 40 significant pathways and four significant networks, involved mainly in apoptosis, mitochondrion dysfunction, and nuclear receptor signaling were identified. Based on our results, we suggest that PGC-1alpha regulated energy metabolism and anti-apoptosis might play an important role in the compensatory mechanism of KD. Our results may lead to the identification of potential diagnostic biomarkers for KD in PBMCs, and may help to understand the pathogenesis of KD. Highlights: • Thirty-four up-regulated genes were detected in KD versus health controls. • Forty pathways and four networks were detected in KD. • PGC-1alpha regulated energy metabolism and anti-apoptosis in KD.

  14. Continuous controllable balloon dilation: a novel approach for cervix dilation

    PubMed Central

    2012-01-01

    Background Cervical dilation using mechanical dilators is associated with various complications, such as uterine perforation, cervical laceration, infections and intraperitoneal hemorrhage. To achieve safe and painless cervical dilation, we constructed a new medical device to achieve confident mechanical cervical dilation: a continuous controllable balloon dilator (CCBD). Methods Controlled pumping of incompressible fluid into the CCBD increases the pressure and outer diameter of the CCBD, continuously dilating the cervical canal. The reliability of the CCBD was confirmed in vitro (testing for consistency and endurance, with no detected risk for breakage) and in vivo. A multi-center clinical study was conducted,with 120 pregnant women randomly assigned to one of three groups: Group I,control group, no dilation;Group II,mechanical dilation, Hegar dilator (HeD); and Group III,CCBD. The tissue material for histological evaluation was obtained from the endocervical mucosa before and after dilation using the HeD or CCBD. Results The CCBD dilations were successful and had no complications in all 40 patients of Group III. The cervical tissue was markedly less damaged after CCBD dilation compared with HeD dilation (epithelium damage: 95% (HeD) vs. 45% (CCBD), P <0.001; basal membrane damage: 82.5% (HeD) vs. 27.5% (CCBD), P <0.001; stromal damage: 62.5% (HeD) vs. 37.5% (CCBD), P <0.01). Cervical hemorrhagia was observed in 90% of the patients after HeD dilation versus in 32.5% of the patients after CCBD dilation. Conclusions The CCBD should be used as a replacement for mechanical dilators to prevent uterine and cervical injury during cervical dilation. Trial registration ISRCTN54007498 PMID:23088906

  15. 6D.03: FLOW-MEDIATED DILATATION (FMD) AND ENDOTHELIUM-INDEPENDENT DILATATION (EID) IN PATIENTS WITH MULTIFOCAL FIBROMUSCULAR DYSPLASIA: A CROSS-SECTIONAL STUDY.

    PubMed

    Khettab, H; Lorthior, A; Niarra, R; Chambon, Y; Jeunemaitre, X; Plouin, P F; Laurent, S; Boutouyrie, P; Azizi, M

    2015-06-01

    Fibromuscular dysplasia (FD) is a rare idiopathic, segmental, non-atherosclerotic non-inflammatory vascular disease. We previously showed that FD is a general arterial disease with focal exacerbation of the trait. However, whether endothelial dysfunction may be involved in the pathophysiology of FD is unclear. In a cross sectional study, we compared the endothelial function between 50 patients with multifocal FD of renal/carotid arteries confirmed by CT-angiography, 50 essential hypertensive (EH) patients matched for age, sex, ethnicity and BP and 50 healthy subjects (HS) matched for age, sex and ethnicity. Exclusion criteria were: tobacco consumption, hypercholesterolemia, diabetes, aspirin or statin treatment. Brachial artery (BA) FMD after release of hand ischemia and glyceryl trinitrate (GTN)-induced EID was measured using a high-resolution radiofrequency-based echotracking system blind to the diagnosis. FD, EH and HS were well matched (52yrs, 85% women, 80% caucasian). SBP was higher in FD (125 ± 15mmHg) and EH (121 ± 12mmHg) than EH (113 ± 10mmHg) despite antihypertensive treatments. BA external diameter was significantly lower in FD than in both HS and EH before, during and after hand ischemia and after GTN. BA intima media thickness (IMT), internal diameter did not differ between the 3 groups. FMD (%) or EID (%) did not significantly differ between the 3 groups. BA flow velocity did not significantly differ in any experimental condition.(Figure is included in full-text article.) : In conclusion, despite showing similar acute vasodilatory responses to flow and GTN, FD patients differed from EH and HS in terms of arterial morphology with smaller BA diameter associated with similar IMT. This paradoxical remodeling may suggest a chronic defect in the endothelium-dependent pathways involved in arterial remodeling in FD patients.

  16. Ventricular expression of atrial natriuretic polypeptide and its relations with hemodynamics and histology in dilated human hearts. Immunohistochemical study of the endomyocardial biopsy specimens.

    PubMed

    Takemura, G; Fujiwara, H; Horike, K; Mukoyama, M; Saito, Y; Nakao, K; Matsuda, M; Kawamura, A; Ishida, M; Kida, M

    1989-11-01

    To investigate the mechanism of expression of atrial natriuretic polypeptide (ANP) in human ventricles, we conducted an immunohistochemical study of ANP in biventricular endomyocardial biopsy specimens obtained from a total of 49 patients with cardiac dilatation due to dilated cardiomyopathy (21 patients), postmyocarditis (18 patients), or volume overload (five patients) and subjects with no dilatation as controls (five patients). Four-micron thick sections were stained by an indirect immunoperoxidase method using monoclonal antibody to alpha-human ANP as the primary antibody. The frequency of ANP-present myocytes was calculated in each specimen and compared with clinical, echocardiographic, hemodynamic, angiographic, and histologic parameters. ANP-present myocytes were noted in all of the 21 patients with dilated cardiomyopathy, in 11 of the 18 patients with postmyocarditis, in four of the five patients with volume overload, and in zero of the five controls. The mean percentage of ANP-present myocytes was significantly greater in the left-side specimens (35 +/- 37%) than in the right-side ones (2 +/- 4%). The percentage of ANP-present myocytes in the left-side specimens significantly correlated with peak systolic or end-diastolic wall stress (r = 0.67 and 0.58), left ventricular end-systolic or end-diastolic volume index (r = 0.75 and 0.69), or left ventricular end-diastolic pressure (r = 0.42) and inversely correlated with ejection fraction (r = -0.73), systolic left ventricular wall thickness (r = -0.58), or cardiac index (r = -0.30). Expression of ANP was rarely seen in the cases with normal wall stresses, normal ejection fraction, normal volume, or normal myocyte size. However, it was seen frequently even in hearts with normal levels of left ventricular end-diastolic pressure and cardiac index (compensated hearts). The percent of ANP-present myocytes in both sides significantly correlated with size of myocytes (r = 0.48 at right and r = 0.57 at left side) or

  17. Understanding the dilation and dilation relaxation behavior of graphite-based lithium-ion cells

    NASA Astrophysics Data System (ADS)

    Bauer, Marius; Wachtler, Mario; Stöwe, Hendrik; Persson, Jon V.; Danzer, Michael A.

    2016-06-01

    The dilation of lithium-ion cells is sensitive towards swelling phenomena caused by both graphite staging processes and lithium plating on graphite anodes. In this work, the dilation behavior of graphite/NMC pouch cells is studied with a focus on relaxation phenomena occurring after current pulses. In order to prevent misleading interpretations due to thermal effects, thermal expansion is quantified and a method for the thermal compensation of dilation data is developed. Dilation data are recorded for quasi-equilibrium cycling as well as for current pulses at high rates. In the quasi-equilibrium case, the staging behavior is characterized based on dilation and voltage data. By comparison with a graphite half-cell measurement, the major effects in full cell dilation are confirmed to be anode related. In the high rate case, the dilation responses to the actual pulse and the subsequent relaxation phases are recorded systematically. Positive and negative relaxation phenomena are observed depending on the SOC. They are ascribed to both graphite staging and lithium plating processes. A model is presented explaining the unexpected relaxation effects by a temporary coexistence of three or more staging compounds during high rate lithiation and delithiation. Our data thereby confirm the shrinking annuli model introduced by Heβ and Novák.

  18. [Etiopathogenesis of dilated cardiomyopathies].

    PubMed

    Petronio, A S; Manes, M T; Di Meco, F; Nardini, V; Pecori, F; Ceccherini-Nellis, L; Barsotti, A; Mariani, M

    1993-12-01

    This study was carried out on 43 patients affected by dilated cardiomyopathy to investigate some of the etiopathological hypotheses on this illness. The Authors investigated: the persistence of virus genoma (coxsackie, HBV) on endomyocardial biopsies; the pattern of the II class major histocompatibility complex (MHC) were in the blood lymphocytes; the microvascular aspect of coronary circulation in the endomyocardial biopsies. Finally, in a separated group of 19 patients, the microvascular circulation was studied on skin biopsies and correlated with diabetic, valvular and normal subject. The results showed a 14% positivity for the presence of the virus genoma and a significant predominate of DR5 in the II class MHC of patients with a worse ventricular function. Capillary vessels of the coronary microcirculation were dilated in the 48% of the patients, especially in more compromised subjects. Viral myocarditis seem to play a role in the etiopathogenesis of dilated cardiomyopathies (DCM) and the pattern of MHC could influence the progression of the illness. The microcirculation is probably a pathophysiological aspect. No etiological hypothesis seems to predominate.

  19. Gastric Necrosis due to Acute Massive Gastric Dilatation

    PubMed Central

    Pergel, Ahmet; Yucel, Ahmet Fikret; Sahin, Dursun Ali; Ozer, Ender

    2013-01-01

    Gastric necrosis due to acute massive gastric dilatation is relatively rare. Vascular reasons, herniation, volvulus, acute gastric dilatation, anorexia, and bulimia nervosa play a role in the etiology of the disease. Early diagnosis and treatment are highly important as the associated morbidity and mortality rates are high. In this case report, we present a case of gastric necrosis due to acute gastric dilatation accompanied with the relevant literature. PMID:23983714

  20. A new methodological approach to assess cardiac work by pressure-volume and stress-length relations in patients with aortic valve stenosis and dilated cardiomyopathy.

    PubMed

    Alter, P; Rupp, H; Rominger, M B; Klose, K J; Maisch, B

    2008-01-01

    In experimental animals, cardiac work is derived from pressure-volume area and analyzed further using stress-length relations. Lack of methods for determining accurately myocardial mass has until now prevented the use of stress-length relations in patients. We hypothesized, therefore, that not only pressure-volume loops but also stress-length diagrams can be derived from cardiac volume and cardiac mass as assessed by cardiac magnetic resonance imaging (CMR) and invasively measured pressure. Left ventricular (LV) volume and myocardial mass were assessed in seven patients with aortic valve stenosis (AS), eight with dilated cardiomyopathy (DCM), and eight controls using electrocardiogram (ECG)-gated CMR. LV pressure was measured invasively. Pressure-volume curves were calculated based on ECG triggering. Stroke work was assessed as area within the pressure-volume loop. LV wall stress was calculated using a thick-wall sphere model. Similarly, stress-length loops were calculated to quantify stress-length-based work. Taking the LV geometry into account, the normalization with regard to ventricular circumference resulted in "myocardial work." Patients with AS (valve area 0.73+/-0.18 cm(2)) exhibited an increased LV myocardial mass when compared with controls (P<0.05). LV wall stress was increased in DCM but not in AS. Stroke work of AS was unchanged when compared with controls (0.539+/-0.272 vs 0.621+/-0.138 Nm, not significant), whereas DCM exhibited a significant depression (0.367+/-0.157 Nm, P<0.05). Myocardial work was significantly reduced in both AS and DCM when compared with controls (129.8+/-69.6, 200.6+/-80.1, 332.2+/-89.6 Nm/m(2), P<0.05), also after normalization (7.40+/-5.07, 6.27+/-3.20, 14.6+/-4.07 Nm/m(2), P<0.001). It is feasible to obtain LV pressure-volume and stress-length diagrams in patients based on the present novel methodological approach of using CMR and invasive pressure measurement. Myocardial work was reduced in patients with DCM and noteworthy

  1. Reactivity to low-flow as a potential determinant for brachial artery flow-mediated vasodilatation.

    PubMed

    Aizawa, Kunihiko; Elyas, Salim; Adingupu, Damilola D; Casanova, Francesco; Gooding, Kim M; Strain, W David; Shore, Angela C; Gates, Phillip E

    2016-06-01

    Previous studies have reported a vasoconstrictor response in the radial artery during a cuff-induced low-flow condition, but a similar low-flow condition in the brachial artery results in nonuniform reactivity. This variable reactivity to low-flow influences the subsequent flow-mediated dilatation (FMD) response following cuff-release. However, it is uncertain whether reactivity to low-flow is important in data interpretation in clinical populations and older adults. This study aimed to determine the influence of reactivity to low-flow on the magnitude of brachial artery FMD response in middle-aged and older individuals with diverse cardiovascular risk profiles. Data were analyzed from 165 individuals, divided into increased cardiovascular risk (CVR: n = 115, 85M, 67.0 ± 8.8 years) and healthy control (CTRL: n = 50, 30M, 63.2 ± 7.2 years) groups. Brachial artery diameter and blood velocity data obtained from Doppler ultrasound were used to calculate FMD, reactivity to low-flow and estimated shear rate (SR) using semiautomated edge-detection software. There was a significant association between reactivity to low-flow and FMD in overall (r = 0.261), CTRL (r = 0.410) and CVR (r = 0.189, all P < 0.05) groups. Multivariate regression analysis found that reactivity to low-flow, peak SR, and baseline diameter independently contributed to FMD along with sex, the presence of diabetes, and smoking (total R(2) = 0.450). There was a significant association between reactivity to low-flow and the subsequent FMD response in the overall dataset, and reactivity to low-flow independently contributed to FMD These findings suggest that reactivity to low-flow plays a key role in the subsequent brachial artery FMD response and is important in the interpretation of FMD data. © 2016 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.

  2. A Symmetry Approach to Time Dilation.

    ERIC Educational Resources Information Center

    Dunne, Peter

    1995-01-01

    Outlines an approach to introduce students to special relativity using a discussion of stopclocks and measurement of the transmission of light pulses to produce a natural derivation of the time dilation factor. Aims at providing a frame of reference from which they can be tempted to explore special relativity at a more sophisticated level. (JRH)

  3. Mathematical Modeling of Blood Clot Fragmentation During Flow-Mediated Thrombolysis

    PubMed Central

    Bajd, Franci; Serša, Igor

    2013-01-01

    A microscale mathematical model of blood clot dissolution based on coarse-grained molecular dynamics is presented. In the model, a blood clot is assumed to be an assembly of blood cells interconnected with elastic fibrin bonds, which are cleaved either biochemically (bond degradation) or mechanically (bond overstretching) during flow-mediated thrombolysis. The effect of a thrombolytic agent on biochemical bond degradation was modeled phenomenologically by assuming that the decay rate of an individual bond is a function of the remaining noncleaved bonds in the vicinity of that bond (spatial corrosion) and the relative stretching of the bond (deformational corrosion). The results of simulations indicate that the blood clot dissolution process progresses by a blood-flow-promoted removal of clot fragments, the sizes of which are flow-dependent. These findings are in good agreement with the results of our recent optical-microscopy experimental studies on a model of blood clot dissolution, as well as with clinical observations. The findings of this study may contribute to a better understanding of the clot fragmentation process and may therefore also help in designing new, safer thrombolytic approaches. PMID:23473501

  4. On turbulence in dilatant dispersions

    NASA Astrophysics Data System (ADS)

    Baumert, Helmut Z.; Wessling, Bernhard

    2016-07-01

    This paper presents a new theory on the behaviour of shear-thickening (dilatant) fluids under turbulent conditions. The structure of a dilatant colloidal fluid in turbulent motion may be characterized by (at least) four characteristic length scales: (i) the ‘statistically largest’ turbulent scale, {λ }0, labeling the begin of the inertial part of the wavenumber spectrum; (ii) the energy-containing scale, { L }; (iii) Kolmogorov’s micro-scale, {λ }{ K }, related with the size of the smallest vortices existing for a given kinematic viscosity and forcing; (iv) the inner (‘colloidal’) micro-scale, {λ }i, typically representing a major stable material property of the colloidal fluid. In particular, for small ratios r={λ }i/{λ }{ K }∼ { O }(1), various interactions between colloidal structures and smallest turbulent eddies can be expected. In the present paper we discuss particularly that for ρ ={λ }0/{λ }{ K }\\to { O }(1) turbulence (in the narrow, inertial sense) is strangled and chaotic but less mixing fluid motions remain. We start from a new stochastic, micro-mechanical turbulence theory without empirical parameters valid for inviscid fluids as seen in publications by Baumert in 2013 and 2015. It predicts e.g. von Karman’s constant correctly as 1/\\sqrt{2 π }=0.399. In its generalized version for non-zero viscosity and shear-thickening behavior presented in this contribution, it predicts two solution branches for the steady state: The first characterizes a family of states with swift (inertial) turbulent mixing and small {λ }{ K }, potentially approaching {λ }i. The second branch characterizes a state family with ρ \\to { O }(1) and thus strangled turbulence, ρ ≈ { O }(1). Stability properties and a potential dynamic commuting between the two solution branches had to be left for future research.

  5. Aortic dilation, genetic testing, and associated diagnoses.

    PubMed

    Zarate, Yuri A; Sellars, Elizabeth; Lepard, Tiffany; Tang, Xinyu; Collins, R Thomas

    2016-04-01

    The aims of this study were to determine the genetic diagnoses most frequently associated with aortic dilation in a large population and to describe the results of genetic testing in the same. A retrospective review of records from patients with known aortic dilation identified through an echocardiogram database was performed. During the study period, different chromosomal microarray platforms and molecular diagnostic techniques were used. A total of 715 patients (mean age, 9.7 years; 67% male) met study inclusion criteria. The overall frequency of underlying presumptive or confirmed genetic diagnoses was 17% (125/715). Molecular evaluation for possible underlying aortopathy-related disorders was performed in 9% of patients (66/715). Next-generation sequencing panels were performed in 16 patients, and pathogenic abnormalities were detected in 4 (25%). Microarrays were conducted in 10% of patients (72/715), with a total of 23 pathogenic copy-number variants identified in 19 patients (26%). Marfan syndrome was the most frequently recognized genetic disorder associated with aortic dilation, but other cytogenetic abnormalities and associated diagnoses also were identified. The differential diagnosis in patients with aortic dilation is broad and includes many conditions outside the common connective tissue disorder spectrum. A genetics evaluation should be considered to assist in the diagnostic evaluation.Genet Med 18 4, 356-363.

  6. Surface dilatational viscosity of Langmuir monolayers

    NASA Astrophysics Data System (ADS)

    Lopez, Juan; Vogel, Michael; Hirsa, Amir

    2003-11-01

    With increased interest in microfluidic systems, interfacial phenomena is receiving more attention. As the length scales of fluid problems decrease, the surface to volume ratio increases and the coupling between interfacial flow and bulk flow becomes increasingly dominated by effects due to intrinsic surface viscosities (shear and dilatational), in comparison to elastic effects (due to surface tension gradients). The surface shear viscosity is well-characterized, as cm-scale laboratory experiments are able to isolate its effects from other interfacial processes (e.g., in the deep-channel viscometer). The same is not true for the dilatational viscosity, because it acts in the direction of surface tension gradients. Their relative strength scale with the capillary number, and for cm-scale laboratory flows, surface tension effects tend to dominate. In microfluidic scale flows, the scaling favors viscosity. We have devised an experimental apparatus which is capable of isolating and enhancing the effects of dilatational viscosity at the cm scales by driving the interface harmonically in time, while keeping the interface flat. In this talk, we shall present both the theory for how this works as well as experimental measurements of surface velocity from which we deduce the dilatational viscosity of several monolayers on the air-water interface over a substantial range of surface concentrations. Anomalous behavior over some range of concentration, which superficially indicates negative viscosity, maybe explained in terms of compositional effects due to large spatial and temporal variations in concentration and corresponding viscosity.

  7. Post-earthquake dilatancy recovery

    NASA Technical Reports Server (NTRS)

    Scholz, C. H.

    1974-01-01

    Geodetic measurements of the 1964 Niigata, Japan earthquake and of three other examples are briefly examined. They show exponentially decaying subsidence for a year after the quakes. The observations confirm the dilatancy-fluid diffusion model of earthquake precursors and clarify the extent and properties of the dilatant zone. An analysis using one-dimensional consolidation theory is included which agrees well with this interpretation.

  8. Airflow and optic flow mediate antennal positioning in flying honeybees

    PubMed Central

    Roy Khurana, Taruni; Sane, Sanjay P

    2016-01-01

    To maintain their speeds during navigation, insects rely on feedback from their visual and mechanosensory modalities. Although optic flow plays an essential role in speed determination, it is less reliable under conditions of low light or sparse landmarks. Under such conditions, insects rely on feedback from antennal mechanosensors but it is not clear how these inputs combine to elicit flight-related antennal behaviours. We here show that antennal movements of the honeybee, Apis mellifera, are governed by combined visual and antennal mechanosensory inputs. Frontal airflow, as experienced during forward flight, causes antennae to actively move forward as a sigmoidal function of absolute airspeed values. However, corresponding front-to-back optic flow causes antennae to move backward, as a linear function of relative optic flow, opposite the airspeed response. When combined, these inputs maintain antennal position in a state of dynamic equilibrium. DOI: http://dx.doi.org/10.7554/eLife.14449.001 PMID:27097104

  9. Flow mediated interactions between two cylinders at finite Re numbers

    NASA Astrophysics Data System (ADS)

    Gazzola, Mattia; Mimeau, Chloe; Tchieu, Andrew A.; Koumoutsakos, Petros

    2012-04-01

    We present simulations of two interacting moving cylinders immersed in a two-dimensional incompressible, viscous flow. Simulations are performed by coupling a wavelet-adapted, remeshed vortex method with the Brinkman penalization and projection approach. This method is validated on benchmark problems and applied to simulations of a master-slave pair of cylinders. The master cylinder's motion is imposed and the slave cylinder is let free to respond to the flow. We study the relative role of viscous and inertia effects in the cylinders interactions and identify related sharp transitions in the response of the slave. The observed differences in the behavior of cylinders with respect to corresponding potential flow simulations are discussed. In addition, it is observed that in certain situations the finite size of the slave cylinders enhances the transport so that the cylinders are advected more effectively than passive tracers placed, respectively, at the same starting position.

  10. Esophageal dilation in eosinophilic esophagitis.

    PubMed

    Richter, Joel E

    2015-10-01

    Tissue remodeling with scaring is common in adult EoE patients with long standing disease. This is the major factor contributing to their complaints of solid food dysphagia and recurrent food impactions. The best tests to define the degree of remodeling are barium esophagram, high resolution manometry and endoscopy. Many physicians are fearful to dilate EoE patients because of concerns about mucosal tears and perforations. However, multiple recent case series attest to the safety of esophageal dilation and its efficacy with many patients having symptom relief for an average of two years. This chapter will review the sordid history of esophageal dilation in EoE patients and outline how to perform this procedure safely. The key is graduated dilation over one to several sessions to a diameter of 15-18 mm. Postprocedural pain is to be expected and mucosal tears are a sign of successful dilation, not complications. In some healthy adults, occasional dilation may be preferred to regular use of medications or restricted diets. This approach is now supported by recent EoE consensus statements and societal guidelines.

  11. Dilatational band formation in bone

    PubMed Central

    Poundarik, Atharva A.; Diab, Tamim; Sroga, Grazyna E.; Ural, Ani; Boskey, Adele L.; Gundberg, Caren M.; Vashishth, Deepak

    2012-01-01

    Toughening in hierarchically structured materials like bone arises from the arrangement of constituent material elements and their interactions. Unlike microcracking, which entails micrometer-level separation, there is no known evidence of fracture at the level of bone’s nanostructure. Here, we show that the initiation of fracture occurs in bone at the nanometer scale by dilatational bands. Through fatigue and indentation tests and laser confocal, scanning electron, and atomic force microscopies on human and bovine bone specimens, we established that dilatational bands of the order of 100 nm form as ellipsoidal voids in between fused mineral aggregates and two adjacent proteins, osteocalcin (OC) and osteopontin (OPN). Laser microdissection and ELISA of bone microdamage support our claim that OC and OPN colocalize with dilatational bands. Fracture tests on bones from OC and/or OPN knockout mice (OC−/−, OPN−/−, OC-OPN−/−;−/−) confirm that these two proteins regulate dilatational band formation and bone matrix toughness. On the basis of these observations, we propose molecular deformation and fracture mechanics models, illustrating the role of OC and OPN in dilatational band formation, and predict that the nanometer scale of tissue organization, associated with dilatational bands, affects fracture at higher scales and determines fracture toughness of bone. PMID:23129653

  12. Polymorphism in the ADRB2 gene explains a small portion of intersubject variability in pain relative to cervical dilation in the first stage of labor.

    PubMed

    Terkawi, Abdullah S; Jackson, William M; Hansoti, Shehnaz; Tabassum, Rabeena; Flood, Pamela

    2014-07-01

    Variability in labor pain has been associated with demographic, clinical, and psychological factors. Polymorphisms of the β2-adrenergic receptor gene (ADRB2) influence sensitivity to experimental pain in humans and are a risk factor for chronic pain. The authors hypothesized that polymorphisms in ADRB2 may influence labor pain. After Institutional Review Board approval and written informed consent, the authors prospectively obtained hourly pain reports from 233 nulliparous parturients during the first stage of labor, of which 199 were included in the current analysis. DNA from blood samples was genotyped at polymorphisms in the genes for the β2-adrenergic receptor, the μ opioid receptor subtype 1, catechol-O-methyltransferase, fatty acid amide hydrolase, and the oxytocin receptor. Labor pain as a function of cervical dilation was modeled with previously described methods. Patient covariates, ADRB2 genotype, and obstetrical and anesthesia treatment were evaluated as covariates in the model. Labor pain more rapidly became severe in parturients heterozygous or homozygous for the G allele at rs1042714 in the ADRB2 gene. Labor pain increased more rapidly after artificial rupture of membranes, augmentation with oxytocin, and in younger women. Inclusion of covariates explained approximately 10% of the variability between subjects. ADRB2 genotype explained less than 1% of the intersubject variability. ADRB2 genotype correlates with labor pain but explained less than 1% of the intersubject variance in the model.

  13. Comparison of pneumatic dilation with pneumatic dilation plus botulinum toxin for treatment of achalasia.

    PubMed

    Bakhshipour, Alireza; Rabbani, Romina; Shirani, Shapoor; Soleimani, Hosein A S L; Mikaeli, Javad

    2010-01-01

    Among the therapeutic options for achalasia are pneumatic dilatation (PD), an appropriate long-term therapy, and botulinum toxin injection (BT) that is a relatively short-term therapy. This study aimed to compare therapeutic effect of repetitive pneumatic dilation with a combined method (botulinum toxin injection and pneumatic dilation) in a group of achalasia patients who are low responder to two initial pneumatic dilations. Thirty-four patients with documented primary achalasia that had low response to two times PD (<50% decrease in symptom score and barium height at 5 minute in timed esophagogram after 3 month of late PD) were randomized to receive pneumatic dilation (n=18) or botulinum toxin injection and pneumatic dilation by four weeks interval (n=16), PD and BT+PD groups respectively. Symptom scores were evaluated before and at 1, 6 and 12 months after treatment. Clinical remission was defined as a decrease in symptom score > or = 50% of baseline. There were no significant differences between the two groups in gender, age and achalasia type. Remission rate of patients in BT-PD group in comparison with PD group were 87.5% vs. 67.1% (P = 0.7), 87.5% vs. 61.1% (P = 0.59) and 87.5% vs. 55.5% (P = 0.53) at 1, 6 and 12 months respectively .There were no major complications in either group. The mean symptom score decreased by 62.71% in the BT-PD group (P < 0.002) and 50.77% in the PD group (P < 0.01) at the end of the first year. Despite a better response rate in BT+PD group, a difference was not statistically significant. A difference may be meaningful if a large numbers of patients are included in the study.

  14. On the Variable Dilatancy Angle in Rocks Around Underground Galleries

    NASA Astrophysics Data System (ADS)

    Salehnia, Fatemeh; Collin, Frédéric; Charlier, Robert

    2017-03-01

    Correct estimation of the dilatant behavior of a rock has an essential role in a realistic numerical simulation of the fracturing threshold during the rock deformation process and its post-failure response, based on experimental and field observations. This importance has been poorly treated in most of the numerical analyses dealing with the rock engineering common problems such as deep excavations. The dilatancy angle as a commonly used parameter for describing the dilatation response of a rock is mostly simplified to be a constant value. Contrarily, a literature review declares the inadequacy of this approach in those rock mechanics applications. In the present paper, a new formula for considering the variable dilatancy angle is presented which relates this parameter to the plastic shear strain in the course of a loading procedure. It is aimed at characterizing an evolution of the dilatant or contracting volumetric response of a rock as well as giving the possibility to simulate a dilatant/contracting transitional behavior. The model is applied to simulate the development of strain localization, in shear band mode, within the inevitable excavation damaged zone created around an underground opening in rock. It is illustrated that using the model of variable dilatancy angle in a deep excavation modeling could help to better reproduce the fractures development around the opening in the course of tunneling.

  15. Assessment of ventricular function in dilated cardiomyopathies.

    PubMed

    Pak, P H; Kass, D A

    1995-05-01

    Regardless of its cause, systolic dysfunction in dilated cardiomyopathy triggers a wide variety of compensatory responses resulting in cardiac dilatation, fluid retention, and systemic vasoconstriction. Standard therapy with vasodilators, digoxin, and diuretics can provide symptomatic relief in many patients. However, many others do not respond adequately, and mortality from heart failure remains high. This has driven the search for novel therapies. To evaluate the efficacy and decipher mechanisms of action of these treatments, accurate assessments of left ventricular function are valuable. In particular, one seeks indexes that are cardiac-specific, in that they are minimally influenced by vascular loading conditions. An increasingly used "gold standard" that can achieve this goal is the invasively measured pressure-volume relation. Newer noninvasive methods have yielded several surrogates that have the key advantage of being applicable to chronic disease assessment. In this report, we review the current state-of-the-art in left ventricular function assessment, and describe recent advances in its noninvasive evaluation.

  16. Time dilation in quantum systems and decoherence

    NASA Astrophysics Data System (ADS)

    Pikovski, Igor; Zych, Magdalena; Costa, Fabio; Brukner, Časlav

    2017-02-01

    Both quantum mechanics and general relativity are based on principles that defy our daily intuitions, such as time dilation, quantum interference and entanglement. Because the regimes where the two theories are typically tested are widely separated, their foundational principles are rarely jointly studied. Recent works have found that novel phenomena appear for quantum particles with an internal structure in the presence of time dilation, which can take place at low energies and in weak gravitational fields. Here we briefly review the effects of time dilation on quantum interference and generalize the results to a variety of systems. In addition, we provide an extended study of the basic principles of quantum theory and relativity that are of relevance for the effects and also address several questions that have been raised, such as the description in different reference frames, the role of the equivalence principle and the effective irreversibility of the decoherence. The manuscript clarifies some of the counterintuitive aspects arising when quantum phenomena and general relativistic effects are jointly considered.

  17. User-guided automated segmentation of time-series ultrasound images for measuring vasoreactivity of the brachial artery induced by flow mediation

    NASA Astrophysics Data System (ADS)

    Sehgal, Chandra M.; Kao, Yen H.; Cary, Ted W.; Arger, Peter H.; Mohler, Emile R.

    2005-04-01

    Endothelial dysfunction in response to vasoactive stimuli is closely associated with diseases such as atherosclerosis, hypertension and congestive heart failure. The current method of using ultrasound to image the brachial artery along the longitudinal axis is insensitive for measuring the small vasodilatation that occurs in response to flow mediation. The goal of this study is to overcome this limitation by using cross-sectional imaging of the brachial artery in conjunction with the User-Guided Automated Boundary Detection (UGABD) algorithm for extracting arterial boundaries. High-resolution ultrasound imaging was performed on rigid plastic tubing, on elastic rubber tubing phantoms with steady and pulsatile flow, and on the brachial artery of a healthy volunteer undergoing reactive hyperemia. The area of cross section of time-series images was analyzed by UGABD by propagating the boundary from one frame to the next. The UGABD results were compared by linear correlation with those obtained by manual tracing. UGABD measured the cross-sectional area of the phantom tubing to within 5% of the true area. The algorithm correctly detected pulsatile vasomotion in phantoms and in the brachial artery. A comparison of area measurements made using UGABD with those made by manual tracings yielded a correlation of 0.9 and 0.8 for phantoms and arteries, respectively. The peak vasodilatation due to reactive hyperemia was two orders of magnitude greater in pixel count than that measured by longitudinal imaging. Cross-sectional imaging is more sensitive than longitudinal imaging for measuring flow-mediated dilatation of brachial artery, and thus may be more suitable for evaluating endothelial dysfunction.

  18. Genetic basis of dilated cardiomyopathy.

    PubMed

    Pérez-Serra, Alexandra; Toro, Rocio; Sarquella-Brugada, Georgia; de Gonzalo-Calvo, David; Cesar, Sergi; Carro, Esther; Llorente-Cortes, Vicenta; Iglesias, Anna; Brugada, Josep; Brugada, Ramon; Campuzano, Oscar

    2016-12-01

    Dilated cardiomyopathy is a rare cardiac disease characterized by left ventricular dilatation and systolic dysfunction leading to heart failure and sudden cardiac death. Currently, despite several conditions have been reported as aetiologies of the disease, a large number of cases remain classified as idiopathic. Recent studies determine that nearly 60% of cases are inherited, therefore due to a genetic cause. Progressive technological advances in genetic analysis have identified over 60 genes associated with this entity, being TTN the main gene, so far. All these genes encode a wide variety of myocyte proteins, mainly sarcomeric and desmosomal, but physiopathologic pathways are not yet completely unraveled. We review the recent published data about genetics of familial dilated cardiomyopathy.

  19. Formation and interpretation of dilatant echelon cracks.

    USGS Publications Warehouse

    Pollard, D.D.; Segall, P.; Delaney, P.T.

    1982-01-01

    The relative displacements of the walls of many veins, joints, and dikes demonstrate that these structures are dilatant cracks. We infer that dilatant cracks propagate in a principal stress plane, normal to the maximum tensile or least compressive stress. Arrays of echelon crack segments appear to emerge from the peripheries of some dilatant cracks. Breakdown of a parent crack into an echelon array may be initiated by a spatial or temporal rotation of the remote principal stresses about an axis parallel to the crack propagation direction. Near the parent-crack tip, a rotation of the local principal stresses is induced in the same sense, but not necessarily through the same angle. Incipient echelon cracks form at the parent-crack tip normal to the local maximum tensile stress. Further longitudinal growth along surfaces that twist about axes parallel to the propagation direction realigns each echelon crack into a remote principal stress plane. The walls of these twisted cracks may be idealized as helicoidal surfaces. An array of helicoidal cracks sweeps out less surface area than one parent crack twisting through the same angle. Thus, many echelon cracks grow from a single parent because the work done in creating the array, as measured by its surface area decreases as the number of cracks increases. -from Authors

  20. Idiopathic dilatation of pulmonary artery

    PubMed Central

    Sharma, Rahul Kumar; Talwar, Deepak; Gupta, Sameer K; Bansal, Shobhit

    2016-01-01

    Idiopathic dilatation of pulmonary arteries (IDPA) is a rare abnormality of pulmonary arteries, the reported incidence in literature being as low as 0.007% in autopsy samples. With the improvement in diagnostic modalities, antemortem diagnosis of IDPA has been increasingly established by excluding diseases that induce pulmonary arterial enlargement. Here, we present a rare case of idiopathic dilatation of the pulmonary artery admitted with shortness of breath where IDPA was diagnosed as an incidental finding using computed tomography pulmonary angiography and cardiac catheterization. PMID:27891002

  1. Fibrosis of extracellular matrix is related to the duration of the disease but is unrelated to the dynamics of collagen metabolism in dilated cardiomyopathy.

    PubMed

    Rubiś, Paweł; Wiśniowska-Śmialek, Sylwia; Wypasek, Ewa; Biernacka-Fijalkowska, Barbara; Rudnicka-Sosin, Lucyna; Dziewiecka, Ewa; Faltyn, Patrycja; Khachatryan, Lusine; Karabinowska, Aleksandra; Kozanecki, Artur; Tomkiewicz-Pająk, Lidia; Podolec, Piotr

    2016-12-01

    Fibrosis of extracellular matrix (ECM) in dilated cardiomyopathy (DCM) corresponds to the myocardial over-production of various types of collagens. However, mechanism of this process is poorly understood. To investigate whether enhanced metabolism of ECM occur in DCM. Seventy consecutive DCM patients (pts) (48 ± 12.1 years, EF 24.4 ± 7.4 %) and 20 healthy volunteers were studied. Based on symptoms duration, pts were divided into new-onset (n = 35, 6 months) and chronic DCM (n = 35, >6 months). Markers of collagen type I and III synthesis-procollagen type I carboxy- and amino-terminal peptides (PICP and PINP) and procollagen type III carboxy- and amino-terminal peptides (PIIICP and PIIINP), collagen 1 (col-1), ECM metabolism controlling factors-tumor growth factor beta-1 (TGF1-β), connective tissue growth factor (CTGF), and ECM degradation enzymes-matrix metalloproteinases (MMP-2, MMP-9) and their tissue inhibitor (TIMP-1) were measured in serum. All pts underwent right ventricular endomyocardial biopsy to study ECM fibrosis. The presence of fibrosis was detected in 24 (34.3 %) pts and was more prevalent in chronic DCM [17 (48.6 %) vs. 7 (20 %), p < 0.01]. The levels of PIIINP [4.41 (2.17-6.08) vs. 3.32 (1.69-5.02) ng/ml, p < 0.001], CTGF [3.82 (0.48-23.87) vs. 2.37 (0.51-25.32) ng/ml, p < 0.01], MMP-2 [6.06 (2.72-14.8) vs. 4.43 (2.27-7.4) ng/ml, p < 0.001], MMP-9 [1.98 (0.28-9.25) vs. 1.01 (0.29-3.59) ng/ml, p < 0.002)], and TIMP-1 [15.29 (1.8-36.17) vs. 2.61 (1.65-24.09) ng/ml, p < 0.004] were significantly higher in DCM, whereas levels of col-1 [57.7 (23.1-233.4) vs. 159.4 (31.2-512.9) pg/ml, p < 0.001] were significantly lower in DCM compared to controls. There were no differences in all measured serum markers of ECM metabolism between newonset and chronic DCM and as well as fibrosis positive and negative pts. Fibrosis was weakly correlated only with the duration of DCM (r = 0.23, p < 0.05), however, not a single serum marker

  2. Congenital duodenal web: successful management with endoscopic dilatation

    PubMed Central

    Poddar, Ujjal; Jain, Vikas; Yachha, Surender Kumar; Srivastava, Anshu

    2016-01-01

    Background and study aims: Congenital duodenal web (CDW) is an uncommon cause of duodenal obstruction and endoscopic balloon dilatation has been reported in just eight pediatric cases to date. Here we are reporting three cases of CDW managed successfully with balloon dilatation. Cases and methods: In 2014 we diagnosed three cases of CDW on the basis of typical radiological and endoscopic findings. Endoscopic balloon dilatation was done under conscious sedation with a through-the-scope controlled radial expansion (CRE) balloon. Results: All three children presented late (median age 8 [range 2 – 9] years) with bilious vomiting, upper abdominal distension, and failure to thrive. One of them had associated Down syndrome and another had horseshoe kidney. In all cases, CDW was observed in the second part of the duodenum beyond the ampulla, causing partial duodenal obstruction. After repeated endoscopic dilatation (2 – 4 sessions), all three patients became asymptomatic. None of the patients experienced complications after balloon dilatation. Conclusions: Duodenal diaphragm should be suspected in patients with abdominal distension with bilious vomiting, even in relatively older children. Endoscopic balloon dilatation is a simple and effective method of treating this condition. PMID:27004237

  3. Resveratrol Improved Flow-Mediated Outward Arterial Remodeling in Ovariectomized Rats with Hypertrophic Effect at High Dose

    PubMed Central

    Petit, Marie; Guihot, Anne-Laure; Grimaud, Linda; Vessieres, Emilie; Toutain, Bertrand; Menet, Marie-Claude; Nivet-Antoine, Valérie; Arnal, Jean-François; Loufrani, Laurent; Procaccio, Vincent; Henrion, Daniel

    2016-01-01

    Objectives Chronic increases in blood flow in resistance arteries induce outward remodeling associated with increased wall thickness and endothelium-mediated dilatation. This remodeling is essential for collateral arteries growth following occlusion of a large artery. As estrogens have a major role in this remodeling, we hypothesized that resveratrol, described as possessing phytoestrogen properties, could improve remodeling in ovariectomized rats. Methods Blood flow was increased in vivo in mesenteric arteries after ligation of adjacent arteries in 3-month old ovariectomized rats treated with resveratrol (5 or 37.5 mg/kg per day: RESV5 or RESV37.5) or vehicle. After 2 weeks arterial structure and function were measured in vitro in high flow (HF) and normal flow (NF) arteries isolated from each rat. Results Arterial diameter was greater in HF than in NF arteries in ovariectomized rats treated with RESV5 or RESV37.5, not in vehicle-treated rats. In mice lacking estrogen receptor alpha diameter was equivalent in HF and NF arteries whereas in mice treated with RESV5 diameter was greater in HF than in NF vessels. A compensatory increase in wall thickness and a greater phenylephrine-mediated contraction were observed in HF arteries. This was more pronounced in HF arteries from RESV37.5-treated rats. ERK1/2 phosphorylation, involved in hypertrophy and contraction, were higher in RESV37.5-treated rats than in RESV5- and vehicle-treated rats. Endothelium-dependent relaxation was greater in HF than in NF arteries in RESV5-treated rats only. In HF arteries from RESV37.5-treated rats relaxation was increased by superoxide reduction and markers of oxidative stress (p67phox, GP91phox) were higher than in the 2 other groups. Conclusion Resveratrol improved flow-mediated outward remodeling in ovariectomized rats thus providing a potential therapeutic tool in menopause-associated ischemic disorders. This effect seems independent of the estrogen receptor alpha. Nevertheless

  4. Decreased nitrate-mediated dilatation in patients with coronary artery ectasia: an ultrasonographic evaluation of brachial artery.

    PubMed

    Aksoy, Yuksel; Acikgoz, Nusret; Sivri, Nasir; Bariskaner, Emrah; Akturk, Erdal; Turhan, Hasan; Yetkin, Ertan

    2006-05-01

    Coronary artery ectasia has been defined as localized or diffuse nonobstructive lesions of the epicardial coronary arteries with a luminal dilation exceeding the 1.5-fold of normal adjacent segment or vessel diameter. Although coronary artery disease is supposed to be responsible for more than 50% of coronary ectasia, the precise pathology of coronary artery ectasia is not clearly understood. The brachial artery ultrasound test for flow-mediated endothelial-dependent vasodilatory function includes administration of sublingual nitrates to examine the vasodilating effect of an exogenous source of nitric oxide. In the present study, we aimed to compare flow-mediated and nitrate-mediated responses of brachial artery in patients with coronary artery ectasia and patients with coronary artery disease. Thirty-six consecutive patients with coronary artery ectasia in combination with coronary artery disease and 42 age-matched and sex-matched patients with coronary artery disease alone were included in the study. Flow-mediated and nitrate-mediated dilatations were measured in all patients using a high-resolution B-mode ultrasonographic system. Baseline brachial artery diameters in patients with coronary artery ectasia were not statistically different from those in patients with coronary artery disease (4.2+/-0.6 vs. 4.0+/-0.6 mm, respectively, P=0.16). Although the forearm flow-mediated dilatation of the patients with coronary artery ectasia did not differ from that of patients with coronary artery disease alone (5.5+/-3.8 vs. 4.8+/-3.6%, respectively, P=0.41), nitrate-mediated dilatation was significantly lower than that of patients with coronary artery disease alone (7.9+/-5.2 vs. 10.9+/-5.4%, respectively, P=0.02). We have shown that patients with coronary artery ectasia have decreased nitrate-mediated response of brachial artery compared with patients with coronary artery disease alone, suggesting more severe dysfunction or, possibly, destruction of the media layer in

  5. Endothelial Dysfunction and Brachial Intima-Media Thickness: Long Term Cardiovascular Risk with Claudication Related to Peripheral Arterial Disease: A Prospective Analysis

    PubMed Central

    Hafner, Franz; Kieninger, Andrea; Meinitzer, Andreas; Gary, Thomas; Froehlich, Harald; Haas, Elke; Hackl, Gerald; Eller, Philipp; Brodmann, Marianne; Seinost, Gerald

    2014-01-01

    Objective Endothelial dysfunction plays a key role in the development, progression, and clinical manifestation of atherosclerosis, and in symptomatic peripheral arterial disease, endothelial dysfunction and enlarged intima-media thickness might be associated with increased cardiovascular risk. Flow-mediated dilatation and serologic parameters are used to evaluate individual endothelial function. Brachial intima-media thickness, a less recognized parameter of cardiovascular risk, is independently associated with coronary artery disease. The aim of this study was to evaluate the prognostic value of ultrasound and serologic parameters of endothelial function in relation to cardiovascular mortality in peripheral arterial disease. Design monocentric, prospective cohort study. Methods Flow mediated dilatation and brachial intima-media thickness were assessed in 184 (124 male) patients with peripheral arterial disease (Rutherford stages 2–3). Serologic parameters of endothelial function included asymmetric dimethylarginine (ADMA), symmetric dimethylarginine (SDMA), and L-homoarginine. Cardiovascular events were recorded during a follow-up of 99.1±11.1 months. Subjects who died of noncardiovascular causes were excluded from further analysis. Results Eighty-two patients (44.6%) died during follow-up after a mean duration of 49.7±28.3 months. There were 49 cardiovascular deaths (59.8%) and 33 other deaths (40.2%). Flow mediated dilatation was associated with cardiovascular death [1.17% (0.0, 4.3) vs. 4.1% (1.2, 6.4), p<0.001]. Intima-media thickness was greater in patients who succumbed to cardiovascular disease [0.37 mm (0.30, 0.41)] than in survivors [0.21 mm (0.15, 0.38), p<0.001]. Brachial intima-media thickness above 0.345 mm was most predictive of cardiovascular death, with sensitivity and specificity values of 0.714 and 0.657, respectively (p<0.001). Furthermore, ADMA levels above 0.745 µmol/l and SDMA levels above 0.825 µmol/l were significantly associated with

  6. Dilated cardiomyopathy and inclusion body myositis.

    PubMed

    Ballo, Piercarlo; Chiodi, Leandro; Cameli, Matteo; Malandrini, Alessandro; Federico, Antonio; Mondillo, Sergio; Zuppiroli, Alfredo

    2012-04-01

    Inclusion body myositis (IBM) is the most common inflammatory myopathy after 50 years of age. In contrast to polymyositis and dermatomyositis, in which cardiac involvement is relatively common, current evidences indicate that IBM is not associated with cardiac disease. We report the case of a patient with biopsy-proven IBM who developed heart failure and major ventricular arrhythmias secondary to dilated cardiomyopathy few months after the clinical onset of IBM, and in whom no pathophysiologic causes explaining cardiac enlargement and dysfunction were found by laboratory and instrumental investigations. The hypothesis of a pathophysiologic association between the two conditions is discussed.

  7. Genetics Home Reference: X-linked dilated cardiomyopathy

    MedlinePlus

    ... Conditions X-linked dilated cardiomyopathy X-linked dilated cardiomyopathy Printable PDF Open All Close All Enable Javascript ... the expand/collapse boxes. Description X-linked dilated cardiomyopathy is a form of heart disease. Dilated cardiomyopathy ...

  8. Role of fault gouge dilatancy on aseismic deformation transients

    NASA Astrophysics Data System (ADS)

    Liu, Yajing; Rubin, Allan M.

    2010-10-01

    In the vicinity of episodic aseismic transients in several subduction zones, the presence of interstitial fluids and near-lithostatic pore pressure has been proposed to interpret seismic observations of high P to S wave speed ratio and high Poisson's ratio. Under such conditions, fault stabilization by dilatancy-induced suction during increased shear strain rates becomes very efficient. We analyze the frictional and hydraulic conditions for spontaneous transients on a fluid-infiltrated fault including dilatancy and pore compaction in the framework of rate and state friction with a "membrane diffusion" approximation. In both a simplified spectral model and a 2-D Cascadia-like subduction fault model, the fault response is mainly controlled by three nondimensional parameters: (1) W/h*, the along-dip width of the high pore pressure, velocity-weakening fault relative to a characteristic nucleation size, (2) a drainage parameter U, the relative time scales for fluid diffusion and friction evolution, and (3) a dilatancy parameter E, the relative contributions to stress drop from dilatancy and friction evolution. The incorporation of dilatancy enables aseismic transients at much larger values of W/h* than is possible under conditions of constant pore pressure. An analytic estimate of the maximum slip velocity as a function of W/h*, E, and U is derived and agrees reasonably well with the simulation results. The dependence of the properties of modeled transients on the drainage parameter U is similar to that on the dilatancy parameter E. For U (E) less than 1, maximum velocity decreases, while recurrence period remains relatively constant. For U (E) greater than 1, maximum velocity approaches the steady state velocity, and recurrence period approaches the period at neutral stability. In the subduction fault model using gabbro gouge friction properties, the slip per episode and the recurrence period increase with W/h*, generally following the trend defined without dilatancy

  9. Antarctic Analog for Dilational Bands on Europa

    NASA Technical Reports Server (NTRS)

    Hurford, T. A.; Brunt, K. M.

    2014-01-01

    Europa's surface shows signs of extension, which is revealed as lithospheric dilation expressed along ridges, dilational bands and ridged bands. Ridges, the most common tectonic feature on Europa, comprise a central crack flanked by two raised banks a few hundred meters high on each side. Together these three classes may represent a continuum of formation. In Tufts' Dilational Model ridge formation is dominated by daily tidal cycling of a crack, which can be superimposed with regional secular dilation. The two sources of dilation can combine to form the various band morphologies observed. New GPS data along a rift on the Ross Ice Shelf, Antarctica is a suitable Earth analog to test the framework of Tufts' Dilational Model. As predicted by Tufts' Dilational Model, tensile failures in the Ross Ice Shelf exhibit secular dilation, upon which a tidal signal can be seen. From this analog we conclude that Tufts' Dilational Model for Europan ridges and bands may be credible and that the secular dilation is most likely from a regional source and not tidally driven.

  10. Antarctic analog for dilational bands on Europa

    NASA Astrophysics Data System (ADS)

    Hurford, T. A.; Brunt, K. M.

    2014-09-01

    Europa's surface shows signs of extension, which is revealed as lithospheric dilation expressed along ridges, dilational bands and ridged bands. Ridges, the most common tectonic feature on Europa, comprise a central crack flanked by two raised banks a few hundred meters high on each side. Together these three classes may represent a continuum of formation. In Tufts' Dilational Model ridge formation is dominated by daily tidal cycling of a crack, which can be superimposed with regional secular dilation. The two sources of dilation can combine to form the various band morphologies observed. New GPS data along a rift on the Ross Ice Shelf, Antarctica is a suitable Earth analog to test the framework of Tufts' Dilational Model. As predicted by Tufts' Dilational Model, tensile failures in the Ross Ice Shelf exhibit secular dilation, upon which a tidal signal can be seen. From this analog we conclude that Tufts' Dilational Model for Europan ridges and bands may be credible and that the secular dilation is most likely from a regional source and not tidally driven.

  11. Diagnostic criteria for congenital biliary dilatation 2015.

    PubMed

    Hamada, Yoshinori; Ando, Hisami; Kamisawa, Terumi; Itoi, Takao; Urushihara, Naoto; Koshinaga, Tsugumichi; Saito, Takeshi; Fujii, Hideki; Morotomi, Yoshiki

    2016-06-01

    The Diagnostic Criteria for Pancreaticobiliary Maljunction 2013 were published by the Japanese Study Group on Pancreaticobiliary Maljunction (JSGPM) in 2014. The committee of JSGPM for diagnostic criteria for pancreaticobiliary maljunction has established the standard diameter of the bile duct, and a definition of dilatation of the bile duct was proposed in 2014. The committee of JSGPM prepared the diagnostic criteria for congenital biliary dilatation in 2014, and a final revised version was approved in 2015. Congenital biliary dilatation is defined as a congenital malformation involving both local dilatation of the extrahepatic bile duct, including the common bile duct, and pancreaticobiliary maljunction. However, cases associated with intrahepatic bile duct dilatation can also be included. Various kinds of pathological conditions can occur on hepatobiliary systems and pancreas by bile duct dilatation and pancreaticobiliary maljunction. For a diagnosis of congenital biliary dilatation, both abnormal dilatation of the bile duct and pancreaticobiliary maljunction must be evident by either imaging test or anatomical examination. Acquired or secondary dilatation of the bile duct by obstruction due to biliary stones or malignancy should be strictly excluded. Diagnostic criteria for congenital biliary dilatation 2015 were established from Japan representing a world first. © 2016 Japanese Society of Hepato-Biliary-Pancreatic Surgery.

  12. Change in dynamic visual acuity (DVA) by pupil dilation.

    PubMed

    Ueda, Tetsuo; Nawa, Yoshiaki; Yukawa, Eiichi; Taketani, Futoshi; Hara, Yoshiaki

    2006-01-01

    This study was conducted to assess dynamic visual acuity (DVA) under pupil dilation. Pupil dilation may negatively affect driving performance. Thirty healthy young adults (mean age 29.4 years) with pupil dilation participated in this study as the Mydrin P group. In addition to them, 15 healthy young adults (mean age 28.5 years) without pupil dilation were enrolled as the control group. DVA was measured binocularly with free-head viewing at 0, 30, 60, 120, and 360 min after mydriatic drop instillation in both eyes. Pupil size was measured at each time. In the Mydrin P group, DVA significantly improved at 30, 60, and 120 min (ANOVA; p < .01) but returned to the predilation level at 360 min (ANOVA; p = .61). Pupil size changed from 4.1 to 7.8 mm (ANOVA; p < .01) at 30 min after the instillation, and this level was maintained up to 120 min but returned to normal within 360 min. In the control group, DVA did not significantly change at all measured times (ANOVA; p > .9). DVA was significantly (p < .05) correlated with the pupil size at all measured times. The improvement in DVA was related to the enlargement of the pupil. This study suggests that the pupil size is one factor that may affect DVA. Potential applications of this study include useful information to assess the effect of pupil dilation on driving performance.

  13. Discussion of “The relation between dilatancy, effective stress and dispersive pressure in granular avalanches” by P. Bartelt and O. Buser (DOI: 10.1007/s11440-016-0463-7)

    USGS Publications Warehouse

    Iverson, Richard M.; George, David L.

    2016-01-01

    A paper recently published by Bartelt and Buser (hereafter identified as “the authors”) aims to clarify relationships between granular dilatancy and dispersive pressure and to question the effective stress principle and its application to shallow granular avalanches (Bartelt and Buser in Act Geotech 11:549–557, 2). The paper also criticizes our own recent work, which utilizes the concepts of evolving dilatancy and effective stress to model the initiation and dynamics of water-saturated landslides and debris flows. Here we first explain why we largely agree with the authors’ views of dilatancy and dispersive pressure as they apply to depth-integrated granular avalanche models, and why we disagree with their views of effective stress and pore-fluid pressure. We conclude by explaining why the authors’ characterization of our recently developed D-Claw model is inaccurate.

  14. Percutaneous dilatational tracheostomy following total artificial heart implantation.

    PubMed

    Spiliopoulos, Sotirios; Dimitriou, Alexandros Merkourios; Serrano, Maria Rosario; Guersoy, Dilek; Autschbach, Ruediger; Goetzenich, Andreas; Koerfer, Reiner; Tenderich, Gero

    2015-07-01

    Coagulation disorders and an immune-altered state are common among total artificial heart patients. In this context, we sought to evaluate the safety of percutaneous dilatational tracheostomy in cases of prolonged need for mechanical ventilatory support. We retrospectively analysed the charts of 11 total artificial heart patients who received percutaneous dilatational tracheostomy. We focused on early and late complications. We observed no major complications and no procedure-related deaths. Early minor complications included venous oozing (45.4%) and one case of local infection. Late complications, including subglottic stenosis, stomal infection or infections of the lower respiratory tract, were not observed. In conclusion, percutaneous dilatational tracheostomy in total artificial heart patients is safe. Considering the well-known benefits of early tracheotomy over prolonged translaryngeal intubation, we advocate early timing of therapy in cases of prolonged mechanical ventilation. © The Author 2015. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

  15. Dilated Cardiomyopathy Induced by Chronic Starvation and Selenium Deficiency

    PubMed Central

    2016-01-01

    Protein energy malnutrition (PEM) has been rarely documented as a cause of cardiovascular abnormalities, including dilated cardiomyopathy. Selenium is responsible for antioxidant defense mechanisms in cardiomyocytes, and its deficiency in the setting of PEM and disease related malnutrition (DRM) may lead to exacerbation of the dilated cardiomyopathy. We report a rare case of a fourteen-year-old boy who presented with symptoms of congestive heart failure due to DRM and PEM (secondary to chronic starvation) along with severe selenium deficiency. An initial echocardiogram showed severely depressed systolic function consistent with dilated cardiomyopathy. Aggressive nutritional support and replacement of selenium and congestive heart failure medications that included diuretics and ACE inhibitors with the addition of carvedilol led to normalization of the cardiac function within four weeks. He continues to have significant weight gain and is currently completely asymptomatic from a cardiovascular standpoint. PMID:27994905

  16. The pupil dilation response to visual detection

    NASA Astrophysics Data System (ADS)

    Privitera, Claudio M.; Renninger, Laura W.; Carney, Thom; Klein, Stanley; Aguilar, Mario

    2008-02-01

    The pupil dilation reflex is mediated by inhibition of the parasympathetic Edinger-Westphal oculomotor complex and sympathetic activity. It has long been documented that emotional and sensory events elicit a pupillary reflex dilation. Is the pupil response a reliable marker of a visual detection event? In two experiments where viewers were asked to report the presence of a visual target during rapid serial visual presentation (RSVP), pupil dilation was significantly associated with target detection. The amplitude of the dilation depended on the frequency of targets and the time of the detection. Larger dilations were associated with trials having fewer targets and with targets viewed earlier during the trial. We also found that dilation was strongly influenced by the visual task.

  17. Mechanism of aortic root dilation and cardiovascular function in tetralogy of Fallot.

    PubMed

    Seki, Mitsuru; Kuwata, Seiko; Kurishima, Clara; Nakagawa, Ryo; Inuzuka, Ryo; Sugimoto, Masaya; Saiki, Hirofumi; Iwamoto, Yoichi; Ishido, Hirotaka; Masutani, Satoshi; Senzaki, Hideaki

    2016-05-01

    The aortic root dilation in tetralogy of Fallot (TOF) is a long-term clinical problem, because a severely dilated aorta can lead to aortic regurgitation, dissection, or rupture, which can be fatal, necessitating surgical intervention. The details of the mechanism of aortic root dilation, however, are unclear. We have shown that aortic stiffness is increased in patients with repaired TOF, and may mirror the histological abnormality of elastic fiber disruption and matrix expansion. This aortic stiffness is related closely to the aortic dilation, indicating that aortic stiffness may be a predictor of outcome of aortic dilation. Furthermore, the aortic volume overload is a very important determinant of aortic diameter in TOF patients before corrective surgery. In addition, a chromosomal abnormality and the transforming growth factor-β signaling pathway, a major contributor to aortic dilation in Marfan syndrome, also affect this mechanism. In this way, aortic dilation in TOF patients is suggested to be a multifactorial disorder. The aim of this review was therefore to clarify the mechanism of aortic dilation in TOF, focusing on recent research findings. Studies linking histopathology, mechanical properties, molecular/cellular physiology, and clinical manifestations of aortic dilation facilitate appropriate treatment intervention and improvement of long-term prognosis of TOF. © 2016 Japan Pediatric Society.

  18. [Monitoring cervical dilatation by impedance].

    PubMed

    Salvat, J; Lassen, M; Sauze, C; Baud, S; Salvat, F

    1992-01-01

    Several different physics procedures have been tried to mechanize the recording of partograms. Can a measure of impedance of tissue Z using potential difference V, according to Ohm's law V = Z1, and 1 is a constant, be correlated with a measure of cervical dilatation using vaginal examination? This was our hypothesis. The tissue impedance meter was made to our design and applied according to a bipolar procedure. Our work was carried out on 28 patients. 10 patients were registered before labour started in order to test the apparatus and to record the impedance variations without labour taking place, and 18 patients were registered in labour to see whether there was any correlation. The level of impedance in the cervix without labour was 302.7 Ohms with a deviation of 8.2. Using student's t tests it was found that there was a significant correlation (p less than 0.001) in four measurements between the impedance measure and measures obtained by extrapolating the degrees of dilatation calculated from vaginal examination. This is a preliminary study in which we have defined the conditions that are necessary to confirm these first results and to further develop the method.

  19. Pupil dilation signals uncertainty and surprise in a learning gambling task.

    PubMed

    Lavín, Claudio; San Martín, René; Rosales Jubal, Eduardo

    2013-01-01

    Pupil dilation under constant illumination is a physiological marker where modulation is related to several cognitive functions involved in daily decision making. There is evidence for a role of pupil dilation change during decision-making tasks associated with uncertainty, reward-prediction errors and surprise. However, while some work suggests that pupil dilation is mainly modulated by reward predictions, others point out that this marker is related to uncertainty signaling and surprise. Supporting the latter hypothesis, the neural substrate of this marker is related to noradrenaline (NA) activity which has been also related to uncertainty signaling. In this work we aimed to test whether pupil dilation is a marker for uncertainty and surprise in a learning task. We recorded pupil dilation responses in 10 participants performing the Iowa Gambling Task (IGT), a decision-making task that requires learning and constant monitoring of outcomes' feedback, which are important variables within the traditional study of human decision making. Results showed that pupil dilation changes were modulated by learned uncertainty and surprise regardless of feedback magnitudes. Interestingly, greater pupil dilation changes were found during positive feedback (PF) presentation when there was lower uncertainty about a future negative feedback (NF); and by surprise during NF presentation. These results support the hypothesis that pupil dilation is a marker of learned uncertainty, and may be used as a marker of NA activity facing unfamiliar situations in humans.

  20. Pupil dilation signals uncertainty and surprise in a learning gambling task

    PubMed Central

    Lavín, Claudio; San Martín, René; Rosales Jubal, Eduardo

    2014-01-01

    Pupil dilation under constant illumination is a physiological marker where modulation is related to several cognitive functions involved in daily decision making. There is evidence for a role of pupil dilation change during decision-making tasks associated with uncertainty, reward-prediction errors and surprise. However, while some work suggests that pupil dilation is mainly modulated by reward predictions, others point out that this marker is related to uncertainty signaling and surprise. Supporting the latter hypothesis, the neural substrate of this marker is related to noradrenaline (NA) activity which has been also related to uncertainty signaling. In this work we aimed to test whether pupil dilation is a marker for uncertainty and surprise in a learning task. We recorded pupil dilation responses in 10 participants performing the Iowa Gambling Task (IGT), a decision-making task that requires learning and constant monitoring of outcomes’ feedback, which are important variables within the traditional study of human decision making. Results showed that pupil dilation changes were modulated by learned uncertainty and surprise regardless of feedback magnitudes. Interestingly, greater pupil dilation changes were found during positive feedback (PF) presentation when there was lower uncertainty about a future negative feedback (NF); and by surprise during NF presentation. These results support the hypothesis that pupil dilation is a marker of learned uncertainty, and may be used as a marker of NA activity facing unfamiliar situations in humans. PMID:24427126

  1. Flow-mediated coupling on projectiles falling in a superlight granular medium

    NASA Astrophysics Data System (ADS)

    Caballero-Robledo, Gabriel A.; Solano-Altamirano, Juan M.; Kamphorst, Vincent; Pacheco-Vázquez, Felipe; Ruiz-Suárez, J. C.

    2012-11-01

    Interesting collective motion emerges when several heavy disks fall in a quasi 2D granular bed of extremely light grains [F. Pacheco-Vázquez and J.C. Ruiz-Suárez, Nat. Comms. 1, 123 (2010)]. In particular, when two disks impact side by side they initially repel, then they attract each other, until they finally stop. We perform experiments and Discrete Element Soft-Particle simulations to determine the range of action and the origin of these attractive and repulsive flow-mediated forces. Our findings suggest that repulsion results from jamming of grains between intruders while attraction would be due to a ``granular pressure'' drop in the region between intruders caused by a high flow velocity of grains: a Bernoulli-like effect.

  2. Elastomeric microposts integrated into microfluidics for flow-mediated endothelial mechanotransduction analysis.

    PubMed

    Lam, Raymond H W; Sun, Yubing; Chen, Weiqiang; Fu, Jianping

    2012-04-24

    Mechanotransduction is known as the cellular mechanism converting insoluble biophysical signals in the local cellular microenvironment (e.g. matrix rigidity, external mechanical forces, and fluid shear) into intracellular signalling to regulate cellular behaviours. While microfluidic technologies support a precise and independent control of soluble factors in the cellular microenvironment (e.g. growth factors, nutrients, and dissolved gases), the regulation of insoluble biophysical signals in microfluidics, especially matrix rigidity and adhesive pattern, has not yet been achieved. Here we reported an integrated soft lithography-compatible microfluidic methodology that could enable independent controls and modulations of fluid shear, substrate rigidity, and adhesive pattern in a microfluidic environment, by integrating micromolded elastomeric micropost arrays and microcontact printing with microfluidics. The geometry of the elastomeric micropost array could be regulated to mediate substrate rigidity and adhesive pattern, and further the elastomeric microposts could be utilized as force sensors to map live-cell subcellular contractile forces. To illustrate the general application of our methodology, we investigated the flow-mediated endothelial mechanotransduction process and examined specifically the involvement of subcellular contractile forces in the morphological realignment process of endothelial cells under a sustained directional fluid shear. Our results showed that the cytoskeletal contractile forces of endothelial cells were spatiotemporally regulated and coordinated to facilitate their morphology elongation process along the direction of flow. Together, our study provided an integrated microfluidic strategy to modulate the in vitro cellular microenvironment with both defined soluble and insoluble signals, and we demonstrated its application to investigate quantitatively the involvement of cytoskeletal contractile forces in the flow-mediated

  3. Elastomeric microposts integrated into microfluidics for flow-mediated endothelial mechanotransduction analysis

    PubMed Central

    Lam, Raymond H. W.; Sun, Yubing; Chen, Weiqiang; Fu, Jianping

    2014-01-01

    Mechanotransduction is known as the cellular mechanism converting insoluble biophysical signals in the local cellular microenvironment (e.g. matrix rigidity, external mechanical forces, and fluid shear) into intracellular signalling to regulate cellular behaviours. While microfluidic technologies support a precise and independent control of soluble factors in the cellular microenvironment (e.g. growth factors, nutrients, and dissolved gases), the regulation of insoluble biophysical signals in microfluidics, especially matrix rigidity and adhesive pattern, has not yet been achieved. Here we reported an integrated soft lithography-compatible microfluidic methodology that could enable independent controls and modulations of fluid shear, substrate rigidity, and adhesive pattern in a microfluidic environment, by integrating micromolded elastomeric micropost arrays and microcontact printing with microfluidics. The geometry of the elastomeric micropost array could be regulated to mediate substrate rigidity and adhesive pattern, and further the elastomeric micropost could be utilized as force sensors to map live-cell subcellular contractile forces. To illustrate the general application of our methodology, we investigated the flow-mediated endothelial mechanotransduction process and examined specifically the involvement of subcellular contractile forces in the morphological realignment process of endothelial cells under a sustained directional fluid shear. Our results showed that the cytoskeletal contractile forces of endothelial cells were spatiotemporally regulated and coordinated to facilitate their morphology elongation process along the direction of flow. Together, our study provided an integrated microfluidic strategy to modulate the in vitro cellular microenvironment with both defined soluble and insoluble signals, and we demonstrated its application to investigate quantitatively the involvement of cytoskeletal contractile forces in the flow-mediated

  4. Interactions between Multiple Recruitment Drivers: Post-Settlement Predation Mortality and Flow-Mediated Recruitment

    PubMed Central

    Knights, Antony M.; Firth, Louise B.; Walters, Keith

    2012-01-01

    Background Dispersal is a primary driver in shaping the future distribution of species in both terrestrial and marine systems. Physical transport by advection can regulate the distance travelled and rate of propagule supply to a habitat but post-settlement processes such as predation can decouple supply from recruitment. The effect of flow-mediated recruitment and predation on the recruitment success of an intertidal species, the eastern oyster Crassostrea virginica was evaluated in two-replicated field experiments. Two key crab species were manipulated to test predator identity effects on oyster mortality. Findings Recruitment was ∼58% higher in high flow compared to low flow, but predation masked those differences. Predation mortality was primarily attributed to the blue crab Callinectes sapidus, whilst the mud crab Panopeus herbstii had no effect on recruit mortality. Recruit mortality from predation was high when recruit densities were high, but when recruit density was low, predation effects were not seen. Under high recruitment (supply), predation determined maximum population size and in low flow environments, recruitment success is likely determined by a combination of recruitment and resource limitation but not predation. Conclusions Four processes are demonstrated: (1) Increases in flow rate positively affect recruitment success; (2) In high flow (recruitment) environments, resource availability is less important than predation; (3) predation is an important source of recruit mortality, but is dependent upon recruit density; and (4) recruitment and/or resource limitation is likely a major driver of population structure and functioning, modifying the interaction between predators and prey. Simultaneous testing of flow-mediated recruitment and predation was required to differentiate between the role of each process in determining population size. Our results reinforce the importance of propagule pressure, predation and post-settlement mortality as

  5. Left ventricular reverse remodeling is not related to biopsy-detected extracellular matrix fibrosis and serum markers of fibrosis in dilated cardiomyopathy, regardless of the definition used for LVRR.

    PubMed

    Rubiś, Paweł; Wiśniowska-Śmiałek, Sylwia; Biernacka-Fijałkowska, Barbara; Rudnicka-Sosin, Lucyna; Wypasek, Ewa; Kozanecki, Artur; Dziewięcka, Ewa; Faltyn, Patrycja; Karabinowska, Aleksandra; Khachatryan, Lusine; Hlawaty, Marta; Leśniak-Sobelga, Agata; Kostkiewicz, Magdalena; Płazak, Wojciech; Podolec, Piotr

    2017-06-01

    Left ventricular reverse remodeling (LVRR) is reported in dilated cardiomyopathy (DCM) patients (pts). However, numerous definitions of LVRR exist. Measurements of serum markers of fibrosis provide insight into myocardial fibrosis. The relationship between LVRR and fibrosis is poorly understood. From July 2014 until October 2015, we included 63 consecutive DCM pts (48 ± 12.1 years, EF 24.4 ± 7.4%) with completed baseline and 3-month follow-up echocardiograms. LVRR was assessed on the basis of four differing definitions. Procollagens type I and III carboxy- and amino-terminal peptides (PICP, PINP, PIIICP, and PIIINP), collagen 1, ostepontin, tumor growth factor beta-1, connective tissue growth factor, and matrix metalloproteinases (MMP-2, MMP-9), and their tissue inhibitor (TIMP-1) were measured in serum. In addition, all pts underwent right ventricular endomyocardial biopsy. Depending on the definition chosen, LVRR could be diagnosed in between 14.3 and 50.8% pts. Regardless of the LVRR definition used, the frequency of LVRR was similar in fibrosis negative and positive DCM. Minor differences of markers of fibrosis were detected between pts with and without LVRR. For every LVRR definition, adjusted and unadjusted models were constructed to evaluate the predictive value of serum fibrosis parameters. Only an increase of TIMP-1 by 1 ng/ml was found to independently increase the probability of LVRR by 0.016%. The choice of a particular definition of LVRR determines the final diagnosis, and this has a profound impact on subsequent management. LVRR is unrelated to biopsy-detected ECM fibrosis. Serum markers of fibrosis are only weakly related to LVRR, and are not of use in the prediction of LVRR.

  6. A Numerical Study on Dilation of a Saw-Toothed Rock Joint Under Direct Shear

    NASA Astrophysics Data System (ADS)

    Oh, J.; Li, Y.; Mitra, R.; Canbulat, I.

    2017-04-01

    The roughness of a rock joint gives rise to the phenomenon of dilatancy. Numerous studies have been conducted to examine their dilation behaviour partly due to its importance as a stabilising effect. While previous researchers have improved the understanding of dilation behaviour and identified important parameters affecting the magnitude of dilation during shear, there is still a lack of quantification of the method for predicting the dilation angle. This paper describes a systematic parametric study to investigate the effect of relative normal stress and geometric properties on the dilation of a saw-toothed rock joint by using a distinct element method code with Voronoi tessellation. The applicability of the numerical model was assessed by calibration with a series of standard laboratory tests. The simulation results indicate that the magnitude of relative normal stress plays the most important role among parameters and quantify how much those parameters affect the dilation behaviour during shear. The findings of this study, presented in a normalised relation, can be employed when dilation values need to be determined in rock engineering practice.

  7. [Percutanous dilation tracheotomy: our experience].

    PubMed

    Domènech, I; Mateu, T; Cisa, E; Juan, A; Gil, E; Palau, M; Dicenta, M

    2004-01-01

    Percutaneous dilation Tracheotomy (PDT) is becoming a popular alternative to surgical tracheotomy. In our hospital, we recently adopted the use of the PDT in intensive care unit patients. The objective [corrected] of this investigation is to characterize and quantify the rate of complications for PDT. A prospective study of 60 PDT performed at different intesive care units, betweem September 2002 to July 2003. The intraoperative time for PDT was 8 minutes. Complications included 6 cases of mild intraoperative hemorrhage, 1 case of moderate intraoperative hemorrhage, 4 cases of mild postoperative hemorrhage and 1 case of subcutaneous emphysema. PDT is a good alternative to surgical tracheotomy and should be added to the otolaryngologists armamentarium of surgical airway procedures.

  8. Cervical dilatation on presentation for preterm labor and subsequent preterm birth.

    PubMed

    How, Helen Y; Khoury, Jane C; Sibai, Baha M

    2009-01-01

    We sought to determine the risk of preterm (< 32 weeks) delivery as it relates to cervical dilatation at presentation of an initial preterm labor admission episode. We retrospectively reviewed the records of all patients presenting with preterm contractions at 22 to 32 weeks' gestation. Multiple regression was used to analyze the relationship between the interval from initial preterm labor admission episode to delivery and cervical dilatation at presentation. Logistic regression analysis was used to identify variables associated with preterm birth. Mean gestational age on admission for preterm labor episode was 28.1 +/- 2.9 weeks. With a cervical dilatation of 0 to 1 cm, 6% of the women delivered within 48 hours, 20% delivered at < 32 weeks, and 38% delivered at < 35 weeks. With cervical dilatation of 6 to 10 cm, 89% delivered in < 24 hours, 11% between 24 and 48 hours, 94% delivered at < 32 weeks, and 100% delivered at < 35 weeks. Time from admission for initial preterm labor episode to delivery was inversely associated with cervical dilatation. Variables associated with preterm birth at < 32 weeks' gestation were cervical dilatation ( P < 0.0001), gestational age ( P < 0.0001), and effacement ( P < 0.0001) at presentation. In women who experience preterm contractions, cervical dilatation on admission is inversely related to interval to delivery. However, women with cervical dilatation of 0 to 1 cm are still at significant risk for preterm delivery: 19/94 (20%) at < 32 weeks' gestation and 40/104 (38%) at < 35 weeks' gestation.

  9. 21 CFR 876.5365 - Esophageal dilator.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Esophageal dilator. 876.5365 Section 876.5365 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5365 Esophageal dilator. (a...

  10. 21 CFR 876.5365 - Esophageal dilator.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Esophageal dilator. 876.5365 Section 876.5365 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5365 Esophageal dilator. (a...

  11. 21 CFR 876.5450 - Rectal dilator.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Rectal dilator. 876.5450 Section 876.5450 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5450 Rectal dilator. (a) Identification. A rectal...

  12. 21 CFR 876.5450 - Rectal dilator.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Rectal dilator. 876.5450 Section 876.5450 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5450 Rectal dilator. (a) Identification. A rectal...

  13. 21 CFR 876.5520 - Urethral dilator.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Urethral dilator. 876.5520 Section 876.5520 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5520 Urethral dilator. (a...

  14. 21 CFR 876.5470 - Ureteral dilator.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ureteral dilator. 876.5470 Section 876.5470 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5470 Ureteral dilator. (a...

  15. 21 CFR 876.5520 - Urethral dilator.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Urethral dilator. 876.5520 Section 876.5520 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5520 Urethral dilator. (a...

  16. 21 CFR 876.5470 - Ureteral dilator.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Ureteral dilator. 876.5470 Section 876.5470 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5470 Ureteral dilator. (a...

  17. 21 CFR 874.3900 - Nasal dilator.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Nasal dilator. 874.3900 Section 874.3900 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES EAR, NOSE, AND THROAT DEVICES Prosthetic Devices § 874.3900 Nasal dilator. (a) Identification. A...

  18. 21 CFR 874.3900 - Nasal dilator.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Nasal dilator. 874.3900 Section 874.3900 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES EAR, NOSE, AND THROAT DEVICES Prosthetic Devices § 874.3900 Nasal dilator. (a) Identification. A...

  19. 21 CFR 874.3900 - Nasal dilator.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Nasal dilator. 874.3900 Section 874.3900 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES EAR, NOSE, AND THROAT DEVICES Prosthetic Devices § 874.3900 Nasal dilator. (a) Identification. A...

  20. Intermittent self-dilatation for urethral stricture disease in males.

    PubMed

    Jackson, Matthew J; Veeratterapillay, Rajan; Harding, Chris K; Dorkin, Trevor J

    2014-12-19

    Intermittent urethral self-dilatation is sometimes recommended to reduce the risk of recurrent urethral stricture. There is no consensus as to whether it is a clinically effective or cost-effective intervention in the management of this disease. The purpose of this review is to evaluate the clinical effectiveness and cost-effectiveness of intermittent self-dilatation after urethral stricture surgery in males compared to no intervention. We also compared different programmes of, and devices for, intermittent self-dilatation. . We searched the Cochrane Incontinence Group Specialised Register (searched 7 May 2014), CENTRAL (2014, Issue 4), MEDLINE (1 January 1946 to Week 3 April 2014), PREMEDLINE (covering 29 April 2014), EMBASE (1 January 1947 to Week 17 2014), CINAHL (31 December 1981 to 30 April 2014) OpenGrey (searched 6 May 2014), ClinicalTrials.gov (6 May 2014), WHO International Clinical Trials Registry Platform (6 May 2014), Current Controlled Trials (6 May 2014) and the reference lists of relevant articles. Randomised and quasi-randomised trials where one arm was a programme of intermittent self-dilatation for urethral stricture were identified. Studies were excluded if they were not randomised or quasi-randomised trials, or if they pertained to clean intermittent self-catheterisation for bladder emptying. Two authors screened the records for relevance and methodological quality. Data extraction was performed according to predetermined criteria using data extraction forms. Analyses were carried out in Cochrane Review Manager (RevMan 5). The primary outcomes were patient-reported symptoms and health-related quality of life, and risk of recurrence; secondary outcomes were adverse events, acceptability of the intervention to patients and cost-effectiveness. Quality of evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. Eleven trials were selected for inclusion in the review, including a total of 776

  1. Intraventricular vortex properties in nonischemic dilated cardiomyopathy.

    PubMed

    Bermejo, Javier; Benito, Yolanda; Alhama, Marta; Yotti, Raquel; Martínez-Legazpi, Pablo; Del Villar, Candelas Pérez; Pérez-David, Esther; González-Mansilla, Ana; Santa-Marta, Cristina; Barrio, Alicia; Fernández-Avilés, Francisco; Del Álamo, Juan C

    2014-03-01

    Vortices may have a role in optimizing the mechanical efficiency and blood mixing of the left ventricle (LV). We aimed to characterize the size, position, circulation, and kinetic energy (KE) of LV main vortex cores in patients with nonischemic dilated cardiomyopathy (NIDCM) and analyze their physiological correlates. We used digital processing of color-Doppler images to study flow evolution in 61 patients with NIDCM and 61 age-matched control subjects. Vortex features showed a characteristic biphasic temporal course during diastole. Because late filling contributed significantly to flow entrainment, vortex KE reached its maximum at the time of the peak A wave, storing 26 ± 20% of total KE delivered by inflow (range: 1-74%). Patients with NIDCM showed larger and stronger vortices than control subjects (circulation: 0.008 ± 0.007 vs. 0.006 ± 0.005 m(2)/s, respectively, P = 0.02; KE: 7 ± 8 vs. 5 ± 5 mJ/m, P = 0.04), even when corrected for LV size. This helped confining the filling jet in the dilated ventricle. The vortex Reynolds number was also higher in the NIDCM group. By multivariate analysis, vortex KE was related to the KE generated by inflow and to chamber short-axis diameter. In 21 patients studied head to head, Doppler measurements of circulation and KE closely correlated with phase-contract magnetic resonance values (intraclass correlation coefficient = 0.82 and 0.76, respectively). Thus, the biphasic nature of filling determines normal vortex physiology. Vortex formation is exaggerated in patients with NIDCM due to chamber remodeling, and enlarged vortices are helpful for ameliorating convective pressure losses and facilitating transport. These findings can be accurately studied using ultrasound.

  2. Intraventricular vortex properties in nonischemic dilated cardiomyopathy

    PubMed Central

    Benito, Yolanda; Alhama, Marta; Yotti, Raquel; Martínez-Legazpi, Pablo; del Villar, Candelas Pérez; Pérez-David, Esther; González-Mansilla, Ana; Santa-Marta, Cristina; Barrio, Alicia; Fernández-Avilés, Francisco; del Álamo, Juan C.

    2014-01-01

    Vortices may have a role in optimizing the mechanical efficiency and blood mixing of the left ventricle (LV). We aimed to characterize the size, position, circulation, and kinetic energy (KE) of LV main vortex cores in patients with nonischemic dilated cardiomyopathy (NIDCM) and analyze their physiological correlates. We used digital processing of color-Doppler images to study flow evolution in 61 patients with NIDCM and 61 age-matched control subjects. Vortex features showed a characteristic biphasic temporal course during diastole. Because late filling contributed significantly to flow entrainment, vortex KE reached its maximum at the time of the peak A wave, storing 26 ± 20% of total KE delivered by inflow (range: 1–74%). Patients with NIDCM showed larger and stronger vortices than control subjects (circulation: 0.008 ± 0.007 vs. 0.006 ± 0.005 m2/s, respectively, P = 0.02; KE: 7 ± 8 vs. 5 ± 5 mJ/m, P = 0.04), even when corrected for LV size. This helped confining the filling jet in the dilated ventricle. The vortex Reynolds number was also higher in the NIDCM group. By multivariate analysis, vortex KE was related to the KE generated by inflow and to chamber short-axis diameter. In 21 patients studied head to head, Doppler measurements of circulation and KE closely correlated with phase-contract magnetic resonance values (intraclass correlation coefficient = 0.82 and 0.76, respectively). Thus, the biphasic nature of filling determines normal vortex physiology. Vortex formation is exaggerated in patients with NIDCM due to chamber remodeling, and enlarged vortices are helpful for ameliorating convective pressure losses and facilitating transport. These findings can be accurately studied using ultrasound. PMID:24414062

  3. Characterization and Long-Term Prognosis of Postmyocarditic Dilated Cardiomyopathy Compared With Idiopathic Dilated Cardiomyopathy.

    PubMed

    Merlo, Marco; Anzini, Marco; Bussani, Rossana; Artico, Jessica; Barbati, Giulia; Stolfo, Davide; Gigli, Marta; Muça, Matilda; Naso, Paola; Ramani, Federica; Di Lenarda, Andrea; Pinamonti, Bruno; Sinagra, Gianfranco

    2016-09-15

    Dilated cardiomyopathy (DC) is the final common pathway of different pathogenetic processes and presents a significant prognostic heterogeneity, possibly related to its etiologic variety. The characterization and long-term prognosis of postmyocarditic dilated cardiomyopathy (PM-DC) remain unknown. This study assesses the clinical-instrumental evolution and long-term prognosis of a large cohort of patients with PM-DC. We analyzed 175 patients affected with DC consecutively enrolled from 1993 to 2008 with endomyocardial biopsy (EMB) data available. PM-DC was defined in the presence of borderline myocarditis at EMB or persistent left ventricular dysfunction 1 year after diagnosis of active myocarditis at EMB. Other patients were defined as affected by idiopathic dilated cardiomyopathy (IDC). Analysis of follow-up evaluations was performed at 24, 60, and 120 months. We found 72 PM-DC of 175 enrolled patients (41%). Compared with IDC, patients with PM-DC were more frequently females and less frequently presented a familial history of DC. No other baseline significant differences were found. During the long-term follow-up (median 154, first to third interquartile range 78 to 220 months), patients with PM-DC showed a trend toward slower disease progression. Globally, 18 patients with PM-DC (25%) versus 49 with IDC (48%) experienced death/heart transplantation (p = 0.045). The prognostic advantage for patients with PM-DC became significant beyond 40 months of follow-up. At multivariable time-dependent Cox analysis, PM-DC was confirmed to have a global independent protective role (hazard ratio 0.53, 95% confidence interval 0.28 to 0.97, p = 0.04). In conclusion, PM-DC is characterized by better long-term prognosis compared with IDC. An exhaustive etiologic characterization appears relevant in the prognostic assessment of DC.

  4. Pupil dilation in the Simon task as a marker of conflict processing.

    PubMed

    van Steenbergen, Henk; Band, Guido P H

    2013-01-01

    Cognitive demands in response conflict paradigms trigger negative affect and avoidance behavior. However, not all response conflict studies show increases in physiological indices of emotional arousal, such as pupil diameter. In contrast to earlier null-results, this study shows for the first time that small (about 0.02 mm) conflict-related pupil dilation can be observed in a Simon task when stimuli do not introduce a light reflex. Results show that response-conflict in Simon trials induces both pupil dilation and reaction-time costs. Moreover, sequential analyses reveal that pupil dilation mirrors the conflict-adaptation pattern observed in reaction time (RT). Although single-trial regression analyses indicated that pupil dilation is likely to reflect more than one process at the same time, in general our findings imply that pupil dilation can be used as an indirect marker of conflict processing.

  5. Pupil dilation in the Simon task as a marker of conflict processing

    PubMed Central

    van Steenbergen, Henk; Band, Guido P. H.

    2013-01-01

    Cognitive demands in response conflict paradigms trigger negative affect and avoidance behavior. However, not all response conflict studies show increases in physiological indices of emotional arousal, such as pupil diameter. In contrast to earlier null-results, this study shows for the first time that small (about 0.02 mm) conflict-related pupil dilation can be observed in a Simon task when stimuli do not introduce a light reflex. Results show that response-conflict in Simon trials induces both pupil dilation and reaction-time costs. Moreover, sequential analyses reveal that pupil dilation mirrors the conflict-adaptation pattern observed in reaction time (RT). Although single-trial regression analyses indicated that pupil dilation is likely to reflect more than one process at the same time, in general our findings imply that pupil dilation can be used as an indirect marker of conflict processing. PMID:23754997

  6. Ultrasound assessment of endothelial-dependent flow-mediated vasodilation of the brachial artery in clinical research.

    PubMed

    Alley, Hugh; Owens, Christopher D; Gasper, Warren J; Grenon, S Marlene

    2014-10-22

    The vascular endothelium is a monolayer of cells that cover the interior of blood vessels and provide both structural and functional roles. The endothelium acts as a barrier, preventing leukocyte adhesion and aggregation, as well as controlling permeability to plasma components. Functionally, the endothelium affects vessel tone. Endothelial dysfunction is an imbalance between the chemical species which regulate vessel tone, thombroresistance, cellular proliferation and mitosis. It is the first step in atherosclerosis and is associated with coronary artery disease, peripheral artery disease, heart failure, hypertension, and hyperlipidemia. The first demonstration of endothelial dysfunction involved direct infusion of acetylcholine and quantitative coronary angiography. Acetylcholine binds to muscarinic receptors on the endothelial cell surface, leading to an increase of intracellular calcium and increased nitric oxide (NO) production. In subjects with an intact endothelium, vasodilation was observed while subjects with endothelial damage experienced paradoxical vasoconstriction. There exists a non-invasive, in vivo method for measuring endothelial function in peripheral arteries using high-resolution B-mode ultrasound. The endothelial function of peripheral arteries is closely related to coronary artery function. This technique measures the percent diameter change in the brachial artery during a period of reactive hyperemia following limb ischemia. This technique, known as endothelium-dependent, flow-mediated vasodilation (FMD) has value in clinical research settings. However, a number of physiological and technical issues can affect the accuracy of the results and appropriate guidelines for the technique have been published. Despite the guidelines, FMD remains heavily operator dependent and presents a steep learning curve. This article presents a standardized method for measuring FMD in the brachial artery on the upper arm and offers suggestions to reduce intra

  7. Forceful dilatation under endoscopic control in the treatment of achalasia: a randomised trial of pneumatic versus metallic dilator.

    PubMed Central

    Mearin, F; Armengol, J R; Chicharro, L; Papo, M; Balboa, A; Malagelada, J R

    1994-01-01

    Forceful dilatation under endoscopic control is a well established treatment of achalasia; several different types of dilators can be used. This study prospectively compared the clinical and manometric efficacy of a single dilatation using two different dilators. Forty one patients were randomly assigned to forceful dilatation under endoscopic control with either a pneumatic dilator (n = 17) or a metallic dilator (n = 24). Thereafter, the patients received periodic clinical and manometric evaluation for one year (before and one, six, and 12 months after dilatation). One month after dilatation all but one of the subjects in each group had experienced good to excellent results and their clinical improvement persisted for the one year follow up. Two patients (one in each group) were perforated during the procedure and required surgical treatment. Recovery was uneventful in both cases. Resting lower oesophageal sphincter pressure (mean (SEM)) significantly and similarly decreased after both methods of dilatation (pneumatic dilator: before dilatation 37 (3) mm Hg, one year after dilatation 18 (3) mm Hg; metallic dilator: before dilatation 34 (2) mm Hg, one year after dilatation 17 (3) mm Hg; p < 0.05 for both). It is concluded that in the treatment of achalasia a single dilatation under endoscopic control with either pneumatic or metallic dilator yield comparable clinical and manometric results and similar complication rates. The use of one or other dilator should depend more on the preference and experience of the endoscopist than on the type of device. PMID:7959186

  8. Genetic Variations Leading to Familial Dilated Cardiomyopathy

    PubMed Central

    Cho, Kae Won; Lee, Jongsung; Kim, Youngjo

    2016-01-01

    Cardiomyopathy is a major cause of death worldwide. Based on pathohistological abnormalities and clinical manifestation, cardiomyopathies are categorized into several groups: hypertrophic, dilated, restricted, arrhythmogenic right ventricular, and unclassified. Dilated cardiomyopathy, which is characterized by dilation of the left ventricle and systolic dysfunction, is the most severe and prevalent form of cardiomyopathy and usually requires heart transplantation. Its etiology remains unclear. Recent genetic studies of single gene mutations have provided significant insights into the complex processes of cardiac dysfunction. To date, over 40 genes have been demonstrated to contribute to dilated cardiomyopathy. With advances in genetic screening techniques, novel genes associated with this disease are continuously being identified. The respective gene products can be classified into several functional groups such as sarcomere proteins, structural proteins, ion channels, and nuclear envelope proteins. Nuclear envelope proteins are emerging as potential molecular targets in dilated cardiomyopathy. Because they are not directly associated with contractile force generation and transmission, the molecular pathways through which these proteins cause cardiac muscle disorder remain unclear. However, nuclear envelope proteins are involved in many essential cellular processes. Therefore, integrating apparently distinct cellular processes is of great interest in elucidating the etiology of dilated cardiomyopathy. In this mini review, we summarize the genetic factors associated with dilated cardiomyopathy and discuss their cellular functions. PMID:27802374

  9. Genetic Variations Leading to Familial Dilated Cardiomyopathy.

    PubMed

    Cho, Kae Won; Lee, Jongsung; Kim, Youngjo

    2016-10-01

    Cardiomyopathy is a major cause of death worldwide. Based on pathohistological abnormalities and clinical manifestation, cardiomyopathies are categorized into several groups: hypertrophic, dilated, restricted, arrhythmogenic right ventricular, and unclassified. Dilated cardiomyopathy, which is characterized by dilation of the left ventricle and systolic dysfunction, is the most severe and prevalent form of cardiomyopathy and usually requires heart transplantation. Its etiology remains unclear. Recent genetic studies of single gene mutations have provided significant insights into the complex processes of cardiac dysfunction. To date, over 40 genes have been demonstrated to contribute to dilated cardiomyopathy. With advances in genetic screening techniques, novel genes associated with this disease are continuously being identified. The respective gene products can be classified into several functional groups such as sarcomere proteins, structural proteins, ion channels, and nuclear envelope proteins. Nuclear envelope proteins are emerging as potential molecular targets in dilated cardiomyopathy. Because they are not directly associated with contractile force generation and transmission, the molecular pathways through which these proteins cause cardiac muscle disorder remain unclear. However, nuclear envelope proteins are involved in many essential cellular processes. Therefore, integrating apparently distinct cellular processes is of great interest in elucidating the etiology of dilated cardiomyopathy. In this mini review, we summarize the genetic factors associated with dilated cardiomyopathy and discuss their cellular functions.

  10. Dilational Response of Voided Polycrystals

    NASA Astrophysics Data System (ADS)

    Savage, Daniel J.; Cazacu, Oana; Knezevic, Marko

    2017-05-01

    Finite-element (FE) cell model computations have been used to gain insights into the ductile response of porous polycrystals. Generally, the behavior of the matrix is described by a J 2-plasticity model. In this article, we present a new computational approach to FE cell models for porous polycrystals deforming by slip based on crystal plasticity. The cell provides the homogenized dilational response, where the constitutive response of every integration point is based on a single-crystal visco-plasticity law. The calculations are performed for a body-centered cubic polycrystal with random texture. Axisymmetric tensile and compressive loadings are imposed corresponding to the fixed values of the stress triaxiality and to two possible values of the Lode parameter. The resulting numerical yield points are compared with those obtained using a J 2-FE cell and an analytical model. The predictions confirm the combined effects of the mean stress and third-invariant on yielding recently revealed by the analytical model.

  11. The genetics of dilated cardiomyopathy

    PubMed Central

    Dellefave, Lisa; McNally, Elizabeth M.

    2010-01-01

    Purpose of review More than forty different individual genes have been implicated in the inheritance of dilated cardiomyopathy. For a subset of these genes, mutations can lead to a spectrum of cardiomyopathy that extends to hypertrophic cardiomyopathy and left ventricular noncompaction. In nearly all cases, there is an increased risk of arrhythmias. With some genetic mutations, extracardiac manifestations are likely to be present. The precise genetic etiology can usually not be discerned from the cardiac and/or extracardiac manifestations and requires molecular genetic diagnosis for prognostic determination and cardiac care. Recent findings Newer technologies are influencing genetic testing, especially cardiomyopathy genetic testing, where an increased number of genes are now routinely being tested simultaneously. While this approach to testing multiple genes is increasing the diagnostic yield, the analysis of multiple genes in one test is also resulting in a large amount of genetic information of unclear significance. Summary Genetic testing is highly useful in the care of patients and families, since it guides diagnosis, influences care and aids in prognosis. However, the large amount of benign human genetic variation may complicate genetic results, and often requires a skilled team to accurately interpret the findings. PMID:20186049

  12. Dilated Cardiomyopathy Revealing Cushing Disease

    PubMed Central

    Marchand, Lucien; Segrestin, Bérénice; Lapoirie, Marion; Favrel, Véronique; Dementhon, Julie; Jouanneau, Emmanuel; Raverot, Gérald

    2015-01-01

    Abstract Cardiovascular impairments are frequent in Cushing's syndrome and the hypercortisolism can result in cardiac structural and functional changes that lead in rare cases to dilated cardiomyopathy (DCM). Such cardiac impairment may be reversible in response to a eucortisolaemic state. A 43-year-old man with a medical past of hypertension and history of smoking presented to the emergency department with global heart failure. Coronary angiography showed a significant stenosis of a marginal branch and cardiac MRI revealed a nonischemic DCM. The left ventricular ejection fraction (LVEF) was estimated as 28% to 30%. Clinicobiological features and pituitary imaging pointed toward Cushing's disease and administration of adrenolytic drugs (metyrapone and ketoconazole) was initiated. Despite the normalization of cortisol which had been achieved 2 months later, the patient presented an acute heart failure. A massive mitral regurgitation secondary to posterior papillary muscle rupture was diagnosed as a complication of the occlusion of the marginal branch. After 6 months of optimal pharmacological treatment for systolic heart failure, as well as treatment with inhibitors of steroidogenesis, there was no improvement of LVEF. The percutaneous mitral valve was therefore repaired and a defibrillator implanted. The severity of heart failure contraindicated pituitary surgery and the patient was instead treated by stereotaxic radiotherapy. This is the first case reporting a Cushing's syndrome DCM without improvement of LVEF despite normalization of serum cortisol levels. PMID:26579807

  13. Dilational Response of Voided Polycrystals

    NASA Astrophysics Data System (ADS)

    Savage, Daniel J.; Cazacu, Oana; Knezevic, Marko

    2017-02-01

    Finite-element (FE) cell model computations have been used to gain insights into the ductile response of porous polycrystals. Generally, the behavior of the matrix is described by a J 2-plasticity model. In this article, we present a new computational approach to FE cell models for porous polycrystals deforming by slip based on crystal plasticity. The cell provides the homogenized dilational response, where the constitutive response of every integration point is based on a single-crystal visco-plasticity law. The calculations are performed for a body-centered cubic polycrystal with random texture. Axisymmetric tensile and compressive loadings are imposed corresponding to the fixed values of the stress triaxiality and to two possible values of the Lode parameter. The resulting numerical yield points are compared with those obtained using a J 2-FE cell and an analytical model. The predictions confirm the combined effects of the mean stress and third-invariant on yielding recently revealed by the analytical model.

  14. Simple fast noninvasive technique for measuring brachial wall mechanics during flow mediated vasodilatation analysis

    NASA Astrophysics Data System (ADS)

    Mahmoud, Ahmed M.; Stapleton, Phoebe A.; Frisbee, Jefferson C.; D'Audiffret, Alexandre; Mukdadi, Osama M.

    2009-02-01

    Measurement of flow-mediated vasodilatation (FMD) in brachial and other conduit arteries has become a common method to asses the status of endothelial function in vivo. In spite of the direct relationship between the arterial wall multi-component strains and FMD responses, direct measurement of wall strain tensor due to FMD has not yet been reported in the literature. In this work, a noninvasive direct ultrasound-based strain tensor measuring (STM) technique is presented to assess changes in the mechanical parameters of the vascular wall during FMD. The STM technique utilizes only sequences of B-mode ultrasound images, and starts with segmenting a region of interest within the artery and providing the acquisition parameters. Then a block matching technique is employed to measure the frame to frame local velocities. Displacements, diameter change, multi-component strain tensor and strain rates are then calculated by integrating or differentiating velocity components. The accuracy of the STM algorithm was assessed using a phantom study, and was further validated using in vivo data from human subjects. Results indicate the validity and versatility of the STM algorithm, and describe how parameters other than the diameter change are sensitive to pre- and post-occlusion, which can then be used for accurate assessment of atherosclerosis.

  15. Clinical significance of main pancreatic duct dilation on computed tomography: Single and double duct dilation

    PubMed Central

    Edge, Mark D; Hoteit, Maarouf; Patel, Amil P; Wang, Xiaoping; Baumgarten, Deborah A; Cai, Qiang

    2007-01-01

    AIM: To study the patients with main pancreatic duct dilation on computed tomography (CT) and thereby to provide the predictive criteria to identify patients at high risk of significant diseases, such as pancreatic cancer, and to avoid unnecessary work up for patients at low risk of such diseases. METHODS: Patients with dilation of the main pancreatic duct on CT at Emory University Hospital in 2002 were identified by computer search. Clinical course and ultimate diagnosis were obtained in all the identified patients by abstraction of their computer database records. RESULTS: Seventy-seven patients were identified in this study. Chronic pancreatitis and pancreatic cancer were the most common causes of the main pancreatic duct dilation on CT. Although the majority of patients with isolated dilation of the main pancreatic duct (single duct dilation) had chronic pancreatitis, one-third of patients with single duct dilation but without chronic pancreatitis had pancreatic malignancies, whereas most of patients with concomitant biliary duct dilation (double duct dilation) had pancreatic cancer. CONCLUSION: Patients with pancreatic double duct dilation need extensive work up and careful follow-up since a majority of these patients are ultimately diagnosed with pancreatic cancer. Patients with single duct dilation, especially such patients without any evidence of chronic pancreatitis, also need careful follow-up since the possibility of pancreatic malignancy, including adenocarcinoma and intraductal papillary mucinous tumors, is still high. PMID:17461473

  16. Nemaline myopathy with dilated cardiomyopathy in childhood.

    PubMed

    Gatayama, Ryohei; Ueno, Kentaro; Nakamura, Hideaki; Yanagi, Sadamitsu; Ueda, Hideaki; Yamagishi, Hiroyuki; Yasui, Seiyo

    2013-06-01

    We present a case of a 9-year-old boy with nemaline myopathy and dilated cardiomyopathy. The combination of nemaline myopathy and cardiomyopathy is rare, and this is the first reported case of dilated cardiomyopathy associated with childhood-onset nemaline myopathy. A novel mutation, p.W358C, in ACTA1 was detected in this patient. An unusual feature of this case was that the patient's cardiac failure developed during early childhood with no delay of gross motor milestones. The use of a β-blocker did not improve his clinical course, and the patient died 6 months after diagnosis of dilated cardiomyopathy. Congenital nonprogressive nemaline myopathy is not necessarily a benign disorder: deterioration can occur early in the course of dilated cardiomyopathy with neuromuscular disease, and careful clinical evaluation is therefore necessary.

  17. An Erupted Dilated Odontoma: A Rare Presentation

    PubMed Central

    Sharma, Gaurav; Nagra, Amritpreet; Singh, Gurkeerat; Nagpal, Archna; Soin, Atul; Bhardwaj, Vishal

    2016-01-01

    A dilated odontoma is an extremely rare developmental anomaly represented as a dilatation of the crown and root as a consequence of a deep, enamel-lined invagination and is considered a severe variant of dens invaginatus. An oval shape of the tooth lacking morphological characteristics of a crown or root implies that the invagination happened in the initial stages of morphodifferentiation. Spontaneous eruption of an odontoma is a rare occurrence and the occurrence of a dilated odontoma in a supernumerary tooth is even rarer with only a few case reports documented in the English literature. We present an extremely rare case of erupted dilated odontoma occurring in the supernumerary tooth in anterior maxillary region in an 18-year-old male, which, to the best of our knowledge, is the first ever case reported in English literature. PMID:26989523

  18. 21 CFR 876.5365 - Esophageal dilator.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... and weighted with mercury or a metal olive-shaped weight that slides on a guide, such as a string or... esophageal or gastrointestinal bougies and the esophageal dilator (metal olive). (b) Classification. Class...

  19. 21 CFR 876.5365 - Esophageal dilator.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... and weighted with mercury or a metal olive-shaped weight that slides on a guide, such as a string or... esophageal or gastrointestinal bougies and the esophageal dilator (metal olive). (b) Classification. Class...

  20. 21 CFR 876.5365 - Esophageal dilator.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... and weighted with mercury or a metal olive-shaped weight that slides on a guide, such as a string or... esophageal or gastrointestinal bougies and the esophageal dilator (metal olive). (b) Classification. Class...

  1. Familial dilated cardiomyopathy: a transverse and longitudinal clinical and echocardiographic study.

    PubMed

    Lestuzzi, C; Nicolosi, G L; Neri, A; Pavan, D; Mimo, R; Dall'Aglio, V; Favero, S; Castorina, G; Zanuttini, D

    1991-11-01

    The familial occurrence of hypertrophic cardiomyopathy is well known; familial dilated cardiomyopathy has so far received less attention. Ten families with two or more members affected by dilated cardiomyopathy were studied by echocardiography. In 3 out of 10 families, a transverse study extended to even apparently healthy subjects was carried out, which included a total of 45 subjects. In 19 out of the 45, dilated cardiomyopathy (either symptomatic or asymptomatic) was diagnosed at echocardiography. Three more relatives, already dead of the disease, were identified through hospital records. A clinical and echocardiographic longitudinal study, lasting up to 11 years, was carried out in 5 of the 10 families. During the follow-up, 8 out of 19 patients who, at first examination were affected by dilated cardiomyopathy, died, one improved, 3 remained in stable condition and 7 were lost at follow-up. One of two patients who presented echocardiographic findings suggestive of border-line dilated cardiomyopathy returned to normality and the other developed dilated cardiomyopathy. The clinical and echocardiographic findings in our patients, and in their relatives, suggest the possibility that idiopathic dilated cardiomyopathy may be a multifactorial disease in which genetic factors might play a variable role.

  2. Aortic dilatation in children with systemic hypertension.

    PubMed

    Gupta-Malhotra, Monesha; Devereux, Richard B; Dave, Archana; Bell, Cynthia; Portman, Ronald; Milewicz, Diana

    2014-04-01

    The aim of the study was to determine the presence of aortic dilatation in hypertensive children, the prevalence of which is 4% to 10% in hypertensive adults. Prospectively enrolled multiethnic children, untreated for their hypertension, underwent an echocardiogram to exclude congenital heart disease and evaluate for end-organ damage and aortic size. The aorta was measured in the parasternal long-axis view at three levels: the sinus of Valsalva, supra-tubular junction, and the ascending aorta. Aortic dilatation was determined by z-score >2 at any one of the levels measured. Hypertension was defined as blood pressure above the 95th percentile based on the Fourth Working Group criteria confirmed by 24-hour ambulatory blood pressure monitoring. Among 142 consecutive hypertensive children (median age, 14 years; 45% females) aortic dilatation was detected in 2.8% (95% confidence interval, 1%-7%; median age, 16 years; 100% females). Children with aortic dilatation, when compared with those without, had significantly more aortic valve insufficiency (P = .005) and left ventricular hypertrophy (P = .018). Prevalence of aortic dilatation was 2.8% and was associated with significantly more aortic insufficiency and left ventricular hypertrophy in comparison to those without aortic dilatation.

  3. Aortic Dilatation in Children with Systemic Hypertension

    PubMed Central

    Gupta-Malhotra, Monesha; Devereux, Richard B.; Dave, Archana; Bell, Cynthia; Portman, Ronald; Milewicz, Diana

    2014-01-01

    Background The aim of the study was to determine presence of aortic dilatation in hypertensive children, the prevalence of which is 4–10% in hypertensive adults. Methods Prospectively enrolled multiethnic children untreated for their hypertension, underwent an echocardiogram to exclude congenital heart disease and evaluate for end-organ damage and aortic size. The aorta was measured in the parasternal long-axis view at 3 levels: the sinus of Valsalva, supra-tubular junction and the ascending aorta. Aortic dilatation was determined by z-score > 2 at any 1 of the levels measured. Hypertension was defined as blood pressure above the 95th percentile based on the Fourth Working Group criteria confirmed by 24-hour ambulatory blood pressure monitoring. Results Among 142 consecutive hypertensive children (median age 14 years, 45% females) aortic dilatation was detected in 2.8% (95% CI 1% to 7%, median age 16 years, 100% females). Children with aortic dilatation, when compared to those without, had significantly more aortic valve insufficiency (p = 0.005) and left ventricular hypertrophy (p = 0.018). Conclusions Prevalence of aortic dilatation was 2.8% and was associated with significantly more aortic insufficiency and left ventricular hypertrophy in comparison to those without aortic dilatation. PMID:24507486

  4. High Dietary Sodium Intake Impairs Endothelium-Dependent Dilation in Healthy Salt-Resistant Humans

    PubMed Central

    DuPont, Jennifer J.; Greaney, Jody L.; Wenner, Megan M.; Lennon-Edwards, Shannon L.; Sanders, Paul W.; Farquhar, William B.; Edwards, David G.

    2014-01-01

    Excess dietary sodium has been linked to the development of hypertension and other cardiovascular diseases. In humans, the effects of sodium consumption on endothelial function have not been separated from the effects on blood pressure. The present study was designed to determine if dietary sodium intake affected endothelium-dependent dilation (EDD) independently of changes in blood pressure. Fourteen healthy salt resistant adults were studied (9M, 5F; age 33 ± 2.4 years) in a controlled feeding study. After a baseline run-in diet, participants were randomized to a 7 day high sodium (HS) (300-350 mmol/day) and 7 day low sodium (LS) (20 mmol/day) diet. Salt resistance, defined as a ≤ 5 mm Hg change in a 24-hour mean arterial pressure, was individually assessed while on the low sodium and high sodium diets and confirmed in the subjects undergoing study (LS: 85±1 mm Hg; HS: 85±2 mmHg). EDD was determined in each subject via brachial artery flow-mediated dilation on the last day of each diet. Sodium excretion increased during the high sodium diet (p < 0.01). EDD was reduced on the high sodium diet (Low: 10.3±0.9%, High: 7.3±0.7%, p < 0.05). The HS diet significantly suppressed plasma renin activity (PRA), plasma angiotensin II, and aldosterone (p < 0.05). These data demonstrate that excess salt intake in humans impairs endothelium-dependent dilation independently of changes in blood pressure. PMID:23263240

  5. Grape polyphenols reduce blood pressure and increase flow-mediated vasodilation in men with metabolic syndrome.

    PubMed

    Barona, Jacqueline; Aristizabal, Juan C; Blesso, Christopher N; Volek, Jeff S; Fernandez, Maria Luz

    2012-09-01

    We evaluated the effects of grape polyphenols in individuals classified with metabolic syndrome (MetS). Men (n = 24) aged 30-70 y were randomly assigned to consume either a freeze-dried grape polyphenol powder (GRAPE) or a placebo for 30 d in a double-blind, crossover design, separated by a 3-wk washout period. Participants were asked to maintain their usual diet and physical activity during the study and abstain from consuming polyphenol-rich foods. MetS criteria including blood pressure (BP) and markers of vascular endothelial function including brachial artery flow-mediated vasodilation (FMD), plasma total nitrite + nitrate (NOx) to estimate NO production, plasma soluble intercellular adhesion molecule-1 (sICAM-1), and soluble vascular cell adhesion molecule-1 (sVCAM-1) were measured at the end of each dietary period. Systolic BP (P < 0.0025) and plasma sICAM-1 concentrations (P < 0.025) were lower, whereas the FMD response was higher (P < 0.0001), during the GRAPE compared with the placebo period. In addition, changes in sVCAM-1 concentrations between periods were positively correlated with changes in systolic BP (r = 0.45; P < 0.05). Although NOx concentrations did not differ between periods, changes in systolic BP were negatively correlated with changes in NOx concentrations (r = -0.44; P < 0.05), indicating the vasodilating properties of NO. Other MetS variables did not differ between the GRAPE and placebo periods. These results suggest that GRAPE polyphenols may potentiate vasorelaxation and reduce BP and circulating cell adhesion molecules, resulting in improvements in vascular function.

  6. Flow-mediated coupling on projectiles falling within a superlight granular medium

    NASA Astrophysics Data System (ADS)

    Solano-Altamirano, J. M.; Caballero-Robledo, G. A.; Pacheco-Vázquez, F.; Kamphorst, V.; Ruiz-Suárez, J. C.

    2013-09-01

    Interesting collective motion emerges when several heavy intruder disks fall in a loose packed, quasi-two-dimensional granular bed of extremely light grains [F. Pacheco-Vázquez and J. C. Ruiz-Suárez, Nat. Commun.2041-172310.1038/ncomms1123 1, 123 (2010)]. In particular, when two disks impact side by side, they initially repel and then they attract each other until they finally stop. Here we perform experiments and discrete-element soft-particle simulations to determine the range of action and the origin of these attractive and repulsive flow-mediated forces. We find that (1) the drag force on the disks fluctuate with a characteristic length linked to force chains that build up and break; (2) the repulsive force is present when the separation of the intruder disks is less than 6 times the size of the grains of the granular bed, which is the size of an aperture that allows a continuous discharge flow from a container; (3) the attractive force has a range of action between 5 and 6 times the size of the intruder disks; and (4) attraction exists only when intruders move faster than 1 m/s. These results suggest that repulsion originates from jamming of grains between intruders, and it supports the idea that attraction could be due to a “granular pressure” drop in the region between intruders caused by a high flow velocity of grains: a Bernoulli-like effect. However, our results do not rule out other mechanisms of interaction, like fluctuation-induced forces.

  7. 21 CFR 884.4250 - Expandable cervical dilator.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Expandable cervical dilator. 884.4250 Section 884....4250 Expandable cervical dilator. (a) Identification. An expandable cervical dilator is an instrument with two handles and two opposing blades used manually to dilate (stretch open) the cervical os. (b...

  8. 21 CFR 884.4250 - Expandable cervical dilator.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Expandable cervical dilator. 884.4250 Section 884....4250 Expandable cervical dilator. (a) Identification. An expandable cervical dilator is an instrument with two handles and two opposing blades used manually to dilate (stretch open) the cervical os. (b...

  9. 21 CFR 884.4270 - Vibratory cervical dilators.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Vibratory cervical dilators. 884.4270 Section 884....4270 Vibratory cervical dilators. (a) Identification. A vibratory cervical dilator is a device designed to dilate the cervical os by stretching it with a power-driven vibrating probe head. The device is...

  10. 21 CFR 884.4270 - Vibratory cervical dilators.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Vibratory cervical dilators. 884.4270 Section 884....4270 Vibratory cervical dilators. (a) Identification. A vibratory cervical dilator is a device designed to dilate the cervical os by stretching it with a power-driven vibrating probe head. The device is...

  11. 21 CFR 884.4250 - Expandable cervical dilator.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Expandable cervical dilator. 884.4250 Section 884....4250 Expandable cervical dilator. (a) Identification. An expandable cervical dilator is an instrument with two handles and two opposing blades used manually to dilate (stretch open) the cervical os. (b...

  12. 21 CFR 884.4250 - Expandable cervical dilator.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Expandable cervical dilator. 884.4250 Section 884....4250 Expandable cervical dilator. (a) Identification. An expandable cervical dilator is an instrument with two handles and two opposing blades used manually to dilate (stretch open) the cervical os. (b...

  13. 21 CFR 884.4260 - Hygroscopic Laminaria cervical dilator.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Hygroscopic Laminaria cervical dilator. 884.4260... Devices § 884.4260 Hygroscopic Laminaria cervical dilator. (a) Identification. A hygroscopic Laminaria cervical dilator is a device designed to dilate (stretch open) the cervical os by cervical insertion of a...

  14. 21 CFR 884.4260 - Hygroscopic Laminaria cervical dilator.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Hygroscopic Laminaria cervical dilator. 884.4260... Devices § 884.4260 Hygroscopic Laminaria cervical dilator. (a) Identification. A hygroscopic Laminaria cervical dilator is a device designed to dilate (stretch open) the cervical os by cervical insertion of a...

  15. 21 CFR 884.4250 - Expandable cervical dilator.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Expandable cervical dilator. 884.4250 Section 884....4250 Expandable cervical dilator. (a) Identification. An expandable cervical dilator is an instrument with two handles and two opposing blades used manually to dilate (stretch open) the cervical os. (b...

  16. 21 CFR 884.4270 - Vibratory cervical dilators.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Vibratory cervical dilators. 884.4270 Section 884....4270 Vibratory cervical dilators. (a) Identification. A vibratory cervical dilator is a device designed to dilate the cervical os by stretching it with a power-driven vibrating probe head. The device is...

  17. 21 CFR 884.4270 - Vibratory cervical dilators.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Vibratory cervical dilators. 884.4270 Section 884....4270 Vibratory cervical dilators. (a) Identification. A vibratory cervical dilator is a device designed to dilate the cervical os by stretching it with a power-driven vibrating probe head. The device is...

  18. 21 CFR 884.4270 - Vibratory cervical dilators.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Vibratory cervical dilators. 884.4270 Section 884....4270 Vibratory cervical dilators. (a) Identification. A vibratory cervical dilator is a device designed to dilate the cervical os by stretching it with a power-driven vibrating probe head. The device is...

  19. 21 CFR 884.4260 - Hygroscopic Laminaria cervical dilator.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Hygroscopic Laminaria cervical dilator. 884.4260... Devices § 884.4260 Hygroscopic Laminaria cervical dilator. (a) Identification. A hygroscopic Laminaria cervical dilator is a device designed to dilate (stretch open) the cervical os by cervical insertion of a...

  20. 21 CFR 884.4260 - Hygroscopic Laminaria cervical dilator.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Hygroscopic Laminaria cervical dilator. 884.4260... Devices § 884.4260 Hygroscopic Laminaria cervical dilator. (a) Identification. A hygroscopic Laminaria cervical dilator is a device designed to dilate (stretch open) the cervical os by cervical insertion of a...

  1. 21 CFR 884.4260 - Hygroscopic Laminaria cervical dilator.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Hygroscopic Laminaria cervical dilator. 884.4260... Devices § 884.4260 Hygroscopic Laminaria cervical dilator. (a) Identification. A hygroscopic Laminaria cervical dilator is a device designed to dilate (stretch open) the cervical os by cervical insertion of a...

  2. Dilated cardiomyopathy in dystrophic epidermolysis bullosa

    PubMed Central

    Sidwell, R; Yates, R; Atherton, D

    2000-01-01

    BACKGROUND—Dystrophic epidermolysis bullosa (DEB) is an uncommon genetic disorder of the skin and mucosae. In 1996, we reported the occurrence of lethal dilated cardiomyopathy (DCM) in two affected children.
METHODS—In the past seven years we have routinely screened patients with severe DEB who have been under the care of this hospital by yearly clinical review, echocardiography, and quantification of plasma selenium and carnitine concentrations, as deficiency of these micronutrients is known to be associated with the development of DCM.
RESULTS—Six of 61 children have developed DCM over the seven year period of this study, four of whom have not been previously reported, and three of whom have since died. We compared the concentrations of selenium and free and total carnitine in the children who developed DCM to concentrations in those with severe DEB who did not. The concentrations of free and total carnitine when first measured were significantly lower in the children with DCM, but the selenium concentrations were not.
CONCLUSIONS—We now believe that DCM is a not infrequent complication of severe recessive DEB, and may be related in part to carnitine concentrations, though the exact mechanism remains unclear. We therefore recommend that patients with this condition should undergo regular cardiac review including echocardiography.

 PMID:10869001

  3. Genetic mutations and mechanisms in dilated cardiomyopathy.

    PubMed

    McNally, Elizabeth M; Golbus, Jessica R; Puckelwartz, Megan J

    2013-01-01

    Genetic mutations account for a significant percentage of cardiomyopathies, which are a leading cause of congestive heart failure. In hypertrophic cardiomyopathy (HCM), cardiac output is limited by the thickened myocardium through impaired filling and outflow. Mutations in the genes encoding the thick filament components myosin heavy chain and myosin binding protein C (MYH7 and MYBPC3) together explain 75% of inherited HCMs, leading to the observation that HCM is a disease of the sarcomere. Many mutations are "private" or rare variants, often unique to families. In contrast, dilated cardiomyopathy (DCM) is far more genetically heterogeneous, with mutations in genes encoding cytoskeletal, nucleoskeletal, mitochondrial, and calcium-handling proteins. DCM is characterized by enlarged ventricular dimensions and impaired systolic and diastolic function. Private mutations account for most DCMs, with few hotspots or recurring mutations. More than 50 single genes are linked to inherited DCM, including many genes that also link to HCM. Relatively few clinical clues guide the diagnosis of inherited DCM, but emerging evidence supports the use of genetic testing to identify those patients at risk for faster disease progression, congestive heart failure, and arrhythmia.

  4. Oxytocin enhances pupil dilation and sensitivity to 'hidden' emotional expressions.

    PubMed

    Leknes, Siri; Wessberg, Johan; Ellingsen, Dan-Mikael; Chelnokova, Olga; Olausson, Håkan; Laeng, Bruno

    2013-10-01

    Sensing others' emotions through subtle facial expressions is a highly important social skill. We investigated the effects of intranasal oxytocin treatment on the evaluation of explicit and 'hidden' emotional expressions and related the results to individual differences in sensitivity to others' subtle expressions of anger and happiness. Forty healthy volunteers participated in this double-blind, placebo-controlled crossover study, which shows that a single dose of intranasal oxytocin (40 IU) enhanced or 'sharpened' evaluative processing of others' positive and negative facial expression for both explicit and hidden emotional information. Our results point to mechanisms that could underpin oxytocin's prosocial effects in humans. Importantly, individual differences in baseline emotional sensitivity predicted oxytocin's effects on the ability to sense differences between faces with hidden emotional information. Participants with low emotional sensitivity showed greater oxytocin-induced improvement. These participants also showed larger task-related pupil dilation, suggesting that they also allocated the most attentional resources to the task. Overall, oxytocin treatment enhanced stimulus-induced pupil dilation, consistent with oxytocin enhancement of attention towards socially relevant stimuli. Since pupil dilation can be associated with increased attractiveness and approach behaviour, this effect could also represent a mechanism by which oxytocin increases human affiliation.

  5. Balloon dilatation in esophageal strictures in epidermolysis bullosa and the role of anesthesia.

    PubMed

    Gollu, Gulnur; Ergun, Ergun; Ates, Ufuk; Can, Ozlem S; Dindar, Huseyin

    2017-02-01

    Esophageal involvement, which causes stricture, is a complication in epidermolysis bullosa. This causes dysphagia and malnutrition and leads to deterioration of skin lesions in these patients. The charts of 11 patients with epidermolysis bullosa and esophageal stricture who were included into dilatation program between 2003 and 2015 were retrospectively reviewed. Seven of the patients were female and four were male. The median age was 14 (2-32) years. The mean body weight of patients was 27.8 (9-51) kg. The location and number of strictured parts of the esophagus were previously evaluated with upper gastrointestinal contrast study and after that flexible endoscopy was used for dilatation. Eight patients had middle esophageal, three patients had proximal esophageal and one of them had both proximal and middle esophageal strictures. The strictures were dilated 56 times in total (mean 5 times). One patient underwent gastrostomy and was medically followed-up after a perforation occurrence during the dilatation procedure. In a 32-year-old female patient, colon interposition was performed after four dilatations since optimal nutritional and developmental status could not be achieved. The dilatation program of nine patients is still in progress. Seven of them can easily swallow solid food but two of them have some difficulties in swallowing between dilatations. One patient rejected the program and quitted, while one patient refused colon interposition and died because of complications related to amyloidosis during the dilatation program. After resolution of the swallowing problem, skin lesions were observed to heal quickly. Epidermolysis bullosa is a rare cause of dysphagia. Esophageal balloon dilatation with flexible endoscopy is a safe and efficient method in patients with this condition. © 2016 International Society for Diseases of the Esophagus.

  6. Contribution of Different Anatomical and Physiologic Factors to Iris Contour and Anterior Chamber Angle Changes During Pupil Dilation: Theoretical Analysis

    PubMed Central

    Jouzdani, Sara; Amini, Rouzbeh; Barocas, Victor H.

    2013-01-01

    Purpose. To investigate the contribution of three anatomical and physiologic factors (dilator thickness, dynamic pupillary block, and iris compressibility) to changes in iris configuration and anterior chamber angle during pupil dilation. Methods. A mathematical model of the anterior segment based on the average values of ocular dimensions was developed to simulate pupil dilation. To change the pupil diameter from 3.0 to 5.4 mm in 10 seconds, active dilator contraction was applied by imposing stress in the dilator region. Three sets of parameters were varied in the simulations: (1) a thin (4 μm, 1% of full thickness) versus a thick dilator (covering the full thickness iris) to quantify the effects of dilator anatomy, (2) in the presence (+PB) versus absence of pupillary block (−PB) to quantify the effect of dynamic motion of aqueous humor from the posterior to the anterior chamber, and (3) a compressible versus an incompressible iris to quantify the effects of iris volume change. Changes in the apparent iris–lens contact and angle open distance (AOD500) were calculated for each case. Results. The thin case predicted a significant increase (average 700%) in iris curvature compared with the thick case (average 70%), showing that the anatomy of dilator plays an important role in iris deformation during dilation. In the presence of pupillary block (+PB), AOD500 decreased 25% and 36% for the compressible and incompressible iris, respectively. Conclusions. Iris bowing during dilation was driven primarily by posterior location of the dilator muscle and by dynamic pupillary block, but the effect of pupillary block was not as large as that of the dilator anatomy according to the quantified values of AOD500. Incompressibility of the iris, in contrast, had a relatively small effect on iris curvature but a large effect on AOD500; thus, we conclude that all three effects are important. PMID:23482467

  7. Cyclosporin A inhibits flow-mediated activation of endothelial nitric-oxide synthase by altering cholesterol content in caveolae.

    PubMed

    Lungu, Andreea O; Jin, Zheng-Gen; Yamawaki, Hideyuki; Tanimoto, Tatsuo; Wong, Chelsea; Berk, Bradford C

    2004-11-19

    Fluid shear stress generated by blood flowing over the endothelium is a major determinant of arterial tone, vascular remodeling, and atherogenesis. Nitric oxide (NO) produced by endothelial NO synthase (eNOS) plays an essential role in regulation of vascular function and structure by blood flow. Although cyclosporin A (CsA), an inhibitory ligand of cyclophilin A, is a widely used immunosuppressive drug, it causes arterial hypertension in part by impairing eNOS-dependent vasodilation. Here we show that CsA inhibits fluid shear stress-mediated eNOS activation in endothelial cells via decreasing cholesterol content in caveolae. Exposure of cultured bovine aortic endothelial cells to 1 mum CsA for 1 h significantly inhibited NO production and eNOS phosphorylation at Ser-1179 induced by flow (shear stress=dynes/cm2). The effect of CsA was not related to inhibition of two known eNOS kinases, protein kinase B (Akt) and protein kinase A, because CsA did not affect Akt or protein kinase A activation. In rabbit aorta perfused ex vivo, CsA also significantly inhibited flow-induced eNOS phosphorylation at Ser-1179 but had no effect on Akt measured by phosphorylation at Ser-473. However, CsA treatment decreased cholesterol content in caveolae and displaced eNOS from caveolae, which may be caused by CsA disrupting the association of caveolin-1 and cyclophilin A. The magnitude of the cholesterol depleting effect was similar to that of beta-cyclodextrin, a cholesterol-binding molecule, and beta-cyclodextrin had a similar inhibitory effect on flow-mediated eNOS activation. Treating bovine aortic endothelial cells for 24 h with 30 mug/ml cholesterol blocked the CsA effect and restored eNOS phosphorylation in response to flow. These data suggest that decreasing cholesterol content in caveolae by CsA is a potentially important pathogenic mechanism for CsA-induced endothelial dysfunction and hypertension.

  8. Nitroglycerine-induced vasodilation for assessment of vascular function: a comparison with flow-mediated vasodilation.

    PubMed

    Maruhashi, Tatsuya; Soga, Junko; Fujimura, Noritaka; Idei, Naomi; Mikami, Shinsuke; Iwamoto, Yumiko; Kajikawa, Masato; Matsumoto, Takeshi; Hidaka, Takayuki; Kihara, Yasuki; Chayama, Kazuaki; Noma, Kensuke; Nakashima, Ayumu; Goto, Chikara; Higashi, Yukihito

    2013-06-01

    Nitroglycerine-induced vasodilation has been used as a control test for flow-mediated vasodilation (FMD) to differentiate endothelium-dependent from endothelium-independent response when evaluating endothelial function in humans. Recently, nitroglycerine-induced vasodilation has also been reported to be impaired in patients with atherosclerosis. The purpose of this study was to determine the relationships between nitroglycerine-induced vasodilation and cardiovascular risk factors. We measured nitroglycerine-induced vasodilation and FMD in 436 subjects who underwent health examinations (mean age, 53 ± 19 years; age range, 19-86 years), including patients with cardiovascular diseases. There was a significant relationship between nitroglycerine-induced vasodilation and FMD (r=0.42; P<0.001). Univariate regression analysis revealed that nitroglycerine-induced vasodilation correlated with age (r=-0.34; P<0.001), systolic blood pressure (r=-0.32; P<0.001), diastolic blood pressure (r=-0.24; P<0.001), heart rate (r=-0.21; P<0.001), glucose (r=-0.23; P<0.001), and smoking pack-year (r=-0.12; P=0.01), as well as Framingham risk score (r=-0.30; P<0.001). Nitroglycerine-induced vasodilation was significantly smaller in patients with cardiovascular disease than in both subjects with and without cardiovascular risk factors (10.5 ± 5.6% versus 13.7 ± 5.4% and 15.3 ± 4.3%; P<0.001, respectively), whereas there was no significant difference in nitroglycerine-induced vasodilation between subjects with and without cardiovascular risk factors. Multivariate analysis revealed that male sex, body mass index, hypertension, diabetes mellitus, baseline brachial artery diameter, and FMD were independent predictors of nitroglycerine-induced vasodilation. These findings suggest that nitroglycerine-induced vasodilation may be a marker of the grade of atherosclerosis. FMD should be interpreted as an index of vascular function reflecting both endothelium-dependent vasodilation and

  9. Relations of exercise blood pressure response to cardiovascular risk factors and vascular function in the Framingham Heart Study.

    PubMed

    Thanassoulis, George; Lyass, Asya; Benjamin, Emelia J; Larson, Martin G; Vita, Joseph A; Levy, Daniel; Hamburg, Naomi M; Widlansky, Michael E; O'Donnell, Christopher J; Mitchell, Gary F; Vasan, Ramachandran S

    2012-06-12

    Exercise blood pressure (BP) is an important marker of left ventricular hypertrophy, incident hypertension, and future cardiovascular events. Although impaired vascular function is hypothesized to influence the BP response during exercise, limited data exist on the association of vascular function with exercise BP in the community. Framingham Offspring cohort participants (n=2115, 53% women, mean age 59 years) underwent a submaximal exercise test (first 2 stages of the Bruce protocol), applanation tonometry, and brachial artery flow-mediated dilation testing. We related exercise systolic and diastolic BP at second stage of the Bruce protocol to standard cardiovascular risk factors and to vascular function measures. In multivariable linear regression models, exercise systolic BP was positively related to age, standing BP, standing heart rate, smoking, body mass index, and the total cholesterol-to-high-density cholesterol ratio (P≤0.01 for all). Similar associations were observed for exercise diastolic BP. Carotid-femoral pulse wave velocity (P=0.02), central pulse pressure (P<0.0001), mean arterial pressure (P=0.04), and baseline brachial flow (P=0.002) were positively associated with exercise systolic BP, whereas flow-mediated dilation was negatively associated (P<0.001). For exercise diastolic BP, forward pressure wave amplitude was negatively related (P<0.0001), whereas mean arterial pressure was positively related (P<0.0001). Increased arterial stiffness and impaired endothelial function are significant correlates of a higher exercise systolic BP response. Our findings suggest that impaired vascular function may contribute to exaggerated BP responses during daily living, resulting in repetitive increments in load on the heart and vessels and increased cardiovascular disease risk.

  10. Sequential probing and dilatation in canalicular stenosis.

    PubMed

    Park, Jongyeop; Kim, Hochang

    2015-11-01

    To assess the usefulness of sequential probing for diagnosing lacrimal canalicular stenosis, and the effectiveness of bicanalicular silicone intubation after sequential dilatation in treatment. Canalicular stenosis was diagnosed by sequential probing in 22 patients (22 eyes) who were misdiagnosed as canalicular obstruction. The patients were treated by bicanalicular silicone intubation after sequential dilatation. Anatomical improvements and functional relief of epiphora were evaluated. In addition, complications were evaluated. The average age of the 22 patients was 57 years, and the average follow-up period was 13 months. The silicone tube was left in place for an average of 14 weeks. The anatomical success rate was 100 %. Fifty-four percent of patients achieved complete relief of epiphora, 32 % partial relief, and 14 % no relief. There were no complications. Sequential probing is an useful diagnostic method for canalicular stenosis. Bicanalicular silicone intubation after sequential dilatation is a simple and effective treatment, and could be performed as primary procedure for canalicular stenosis before invasive surgery.

  11. Dilated cardiomyopathy and progressive familial intrahepatic cholestasis

    PubMed Central

    James, Stephanie; Waterhouse, Deirdre; McDonald, Kenneth; O'Hanlon, Rory

    2014-01-01

    This case is of a 29-year-old man with progressive familial intrahepatic cholestasis type 1 also known as Byler's disease. At the age of 21, our patient developed non-ischaemic dilated cardiomyopathy. Cardiac MRI demonstrated global wall thinning, with significant areas of myocardial fibrosis in the mid and epicardial walls from base to apex on postgadolinium late contrast enhanced images. No shared genetic loci between dilated cardiomyopathy and Byler's or cholestatic liver disease have yet been found. This presents the first documented case of non-ischaemic dilated cardiomyopathy, with evidence of mid wall fibrosis, in association with an established diagnosis of progressive familial intrahepatic cholestasis type 1 since childhood. PMID:24654243

  12. Ageing is a process where the growth effect of neuronal noradrenaline changes progressively in favour of the flow mediated, neurodegenerative and inflammatory effect of plasma noradrenaline.

    PubMed

    Crotty, T P

    2016-08-01

    The noradrenaline stimulus has two components, one excitor, the other inhibitory. Neuronal noradrenaline is the excitor component and plasma noradrenaline is the inhibitory. The balance of effect between the two, the noradrenergic balance, is the controlled variable of the sympathetic system and determines the effect of noradrenaline. Neuronal noradrenaline stimulates tissues by diffusion from their sympathetic nerve endings, plasma noradrenaline does so by diffusion from their microcirculations. Changes in microcirculatory flow, by altering the flow mediated effect of plasma noradrenaline, are mainly responsible for altering the noradrenergic balance in the peripheral tissues; changes in CSF flow are speculated to be mainly responsible for doing the same in the brain, by altering the balance between synaptic noradrenaline in the brain and nonsynaptic noradrenaline in the subarachnoid CSF. When plasma noradrenaline alters the noradrenergic balance it triggers afferent sympathetic activity that alerts hypothalamic neurons to the event and they restore the balance and tissue homeostasis, within milliseconds, by adjusting the level of efferent sympathetic activity they project back to the affected tissue. Because the restoration is so rapid the effect of plasma noradrenaline is normally unobservable and dismissed as not having occurred. Because the hypothalamus is not involved with the responses of isolated canine lateral saphenous vein segments to noradrenaline, the effects of plasma noradrenaline in that preparation are not countered by reactive efferent activity and, consequently, are readily apparent in it. Quantitatively, they have been found to be a function of microcirculatory flow and noradrenaline concentration and, qualitatively, to be inhibitory, dilator, pro inflammatory and neurodegenerative. In life, due to a progressive increase in plasma noradrenaline concentration and, more so, in microcirculatory flow, the noradrenergic balance moves progressively in

  13. Flow-mediated-paradoxical vasoconstriction is independently associated with asymptomatic myocardial ischemia and coronary artery disease in type 2 diabetic patients.

    PubMed

    Nguyen, Minh Tuan; Pham, Isabelle; Valensi, Paul; Rousseau, Hélène; Vicaut, Eric; Laguillier-Morizot, Christelle; Nitenberg, Alain; Cosson, Emmanuel

    2014-01-15

    To investigate whether flow-mediated dilation (FMD) impairment, which precedes overt atherosclerosis, is associated with silent myocardial ischemia (SMI) and asymptomatic coronary artery disease (CAD) in type 2 diabetes. Forearm FMD was measured by ultrasonography in 25 healthy control, 30 non-diabetic overweight or obese patients and 118 asymptomatic type 2 diabetic patients with a high cardiovascular risk profile. SMI (abnormal stress myocardial scintiscan and/or stress dobutamine echocardiogram) and CAD (coronary angiography in the patients with SMI) were assessed in the diabetic cohort. FMD was lower in diabetic patients (median 0.61% (upper limits of first and third quartiles -1.22;3.2)) than in healthy controls (3.95% (1.43;5.25), p < 0.01) and overweight/obese patients (4.25% (1.74;5.56), p < 0.01). SMI was present in 60 diabetic patients, including 21 subjects with CAD. FMD was lower in patients with SMI than in those without (0.12% (-2.3;1.58) vs 1.64% (0;3.69), p < 0.01), with a higher prevalence of paradoxical vasoconstriction (50.0% vs 29.3%, p < 0.05). FMD was also lower in patients with than without CAD (-1.22% (-2.5;1) vs 1.13% (-0.4;3.28), p < 0.01; paradoxical vasoconstriction 61.9% vs 34.4%, p < 0.05). Logistic regression analyses considering the parameters predicting SMI or CAD in univariate analyses with a p value <0.10 showed that paradoxical vasoconstriction (odds ratio 2.7 [95% confidence interval 1.2-5.9], p < 0.05) and nephropathy (OR 2.6 [1.2-5.7], p < 0.05) were independently associated with SMI; and only paradoxical vasoconstriction (OR 3.1 [1.2-8.2], p < 0.05) with CAD. The negative predictive value of paradoxical vasoconstriction to detect CAD was 88.7%. In diabetic patients, FMD was independently associated with SMI and asymptomatic CAD. Trial registration number NCT00685984.

  14. Factors affecting pupil size after dilatation: the Twin Eye Study

    PubMed Central

    Hammond, C.; Snieder, H.; Spector, T.; Gilbert, C.

    2000-01-01

    BACKGROUND/AIMS—Well dilated pupils make eye surgery easier. A classic twin study was established to examine the relative importance of genes and environment in the variance of pupil size after mydriasis, and to examine the effects of other factors such as age, iris colour, and refractive error.
METHODS—506 twin pairs, 226 monozygotic (MZ) and 280 dizygotic (DZ), aged 49-79 (mean age 62.2 years, SD 5.7) were examined. Dilated pupil size was measured using a standardised grid superimposed over digital retroillumination images taken 50-70 minutes after mydriasis using tropicamide 1% and phenylephrine 10%. Univariate maximum likelihood model fitting was used to estimate genetic and environmental variance components.
RESULTS—Dilated pupil size was more highly correlated in MZ compared with DZ twins (intraclass correlation coefficients 0.82 and 0.39 respectively). A model specifying additive genetic and unique environmental factors showed the best fit to the data, yielding a heritability of 78-80%. Individual environmental factors explained 18-19% of the variance in this population. Age only accounted for 2-3% of the variance and refractive error and iris colour did not significantly contribute to the variance.
CONCLUSIONS—Pupil size after mydriasis is largely genetically determined, with a heritability of up to 80%.

 PMID:11004106

  15. Factors affecting pupil size after dilatation: the Twin Eye Study.

    PubMed

    Hammond, C J; Snieder, H; Spector, T D; Gilbert, C E

    2000-10-01

    Well dilated pupils make eye surgery easier. A classic twin study was established to examine the relative importance of genes and environment in the variance of pupil size after mydriasis, and to examine the effects of other factors such as age, iris colour, and refractive error. 506 twin pairs, 226 monozygotic (MZ) and 280 dizygotic (DZ), aged 49-79 (mean age 62.2 years, SD 5.7) were examined. Dilated pupil size was measured using a standardised grid superimposed over digital retroillumination images taken 50-70 minutes after mydriasis using tropicamide 1% and phenylephrine 10%. Univariate maximum likelihood model fitting was used to estimate genetic and environmental variance components. Dilated pupil size was more highly correlated in MZ compared with DZ twins (intraclass correlation coefficients 0.82 and 0.39 respectively). A model specifying additive genetic and unique environmental factors showed the best fit to the data, yielding a heritability of 78-80%. Individual environmental factors explained 18-19% of the variance in this population. Age only accounted for 2-3% of the variance and refractive error and iris colour did not significantly contribute to the variance. Pupil size after mydriasis is largely genetically determined, with a heritability of up to 80%.

  16. Allograft pathology in patients transplanted for idiopathic dilated cardiomyopathy.

    PubMed

    Zhang, Mingchang; Tavora, Fabio; Huebner, Thomas; Heath, Jonathan; Burke, Allen

    2012-03-01

    There are few morphologic studies on idiopathic dilated cardiomyopathy (CM) treated with transplant. We prospectively correlated gross, histologic, and clinical findings pertaining to hearts explanted in a 5-year period from patients with a clinical diagnosis of nonischemic CM and also correlated left ventricular diameter with preoperative echocardiographic reports. Of 64 patients with a clinical diagnosis of dilated cardiomyopathy (DC), 42 were men (age, 51 ± 13 y) and 22 were women (age, 42 ± 18 y). The pathologic diagnosis was idiopathic (dilated) cardiomyopathy (DC) in 55 patients (86%) and features of specific CM in 9 patients (14%). Specific diagnoses were fibrofatty change consistent with arrhythmogenic right ventricular cardiomyopathy (n=6), amyloidosis (n=2), and sarcoidosis (n=1), none of which were suspected clinically. The 55 hearts with idiopathic DC had a mean heart weight of 508 (range, 220 to 980) g. Pathologic subsets of the DC group included 4 hearts without enlargement, cavity dilatation, or significant histologic findings (minimal DC); 3 hearts with histologic evidence of healed myocarditis; and 5 hearts with mildly noncompacted left ventricle with hypertrabeculation. Five patients had prior mitral or tricuspid valve replacement/repairs to manage heart failure. There were 7 postpartum DC cases, 1 with a histologic pattern of healed myocarditis and 1 alcoholism-associated DC. Familial DC comprised 16% (9 of 55) of patients. In patients without prior assist device placement, pathologic left ventricular cavity diameter correlated with echocardiographic end-diastolic volume (r , 0.8, P<0.0001). Morphologically, DC is a heterogeneous group. Areas of fibrofatty change and features of noncompaction are not uncommon. Left ventricular measurement at explant correlates well with echocardiographic findings, with a relatively consistent underestimation of the diameter.

  17. Slip and Dilation Tendency Analysis of the Tuscarora Geothermal Area

    DOE Data Explorer

    Faulds, James E.

    2013-12-31

    Critically stressed fault segments have a relatively high likelihood of acting as fluid flow conduits (Sibson, 1994). As such, the tendency of a fault segment to slip (slip tendency; Ts; Morris et al., 1996) or to dilate (dilation tendency; Td; Ferrill et al., 1999) provides an indication of which faults or fault segments within a geothermal system are critically stressed and therefore likely to transmit geothermal fluids. The slip tendency of a surface is defined by the ratio of shear stress to normal stress on that surface: Ts = τ / σn (Morris et al., 1996). Dilation tendency is defined by the stress acting normal to a given surface: Td = (σ1-σn) / (σ1-σ3) (Ferrill et al., 1999). Slip and dilation were calculated using 3DStress (Southwest Research Institute). Slip and dilation tendency are both unitless ratios of the resolved stresses applied to the fault plane by ambient stress conditions. Values range from a maximum of 1, a fault plane ideally oriented to slip or dilate under ambient stress conditions to zero, a fault plane with no potential to slip or dilate. Slip and dilation tendency values were calculated for each fault in the focus study areas at, McGinness Hills, Neal Hot Springs, Patua, Salt Wells, San Emidio, and Tuscarora on fault traces. As dip is not well constrained or unknown for many faults mapped in within these we made these calculations using the dip for each fault that would yield the maximum slip tendency or dilation tendency. As such, these results should be viewed as maximum tendency of each fault to slip or dilate. The resulting along-fault and fault-to-fault variation in slip or dilation potential is a proxy for along fault and fault-to-fault variation in fluid flow conduit potential. Stress Magnitudes and directions Stress field variation within each focus area was approximated based on regional published data and the world stress database (Hickman et al., 2000; Hickman et al., 1998 Robertson-Tait et al., 2004; Hickman and Davatzes

  18. [Pneumatic dilation in the treatment of achalasia].

    PubMed

    Ruiz Cuesta, Patricia; Hervás Molina, Antonio José; Jurado García, Juan; Pleguezuelo Navarro, María; García Sánchez, Valle; Casáis Juanena, Luis L; Gálvez Calderón, Carmen; Naranjo Rodríguez, Antonio

    2013-10-01

    Pneumatic dilation and surgical myotomy are currently the procedures of choice to treat achalasia. The selection of one or other treatment depends on the experience of each center and patient preferences. To review the experience of pneumatic dilation in patients with achalasia in our center. We included all patients with a clinical, endoscopic and manometric diagnosis compatible with achalasia who underwent pneumatic dilation in a 19-year period. All dilations were routinely performed with a Rigiflex(®) balloon, usually at pressures of 250, 250 and 300mm Hg in three inflations of one minute, each separated by one minute. The success of the dilation was assessed on the basis of the patient's symptoms, the number of sessions, the need for surgery, and the presence of complications. A total of 171 patients were included, 53.2% men and 46.8% women, with a mean age of 51.53±17.78 years (16-87 years), from June 1993 to October 2012. A 35-mm balloon was used in 157 patients, a 30-mm balloon in 9 patients and a 40-mm balloon in 7 patients. A single dilation session was required in 108 patients, two sessions were required in 56 patients, with a mean time between the first and second sessions of 25.23±43.25 months (1-215 months), and 3 sessions were required in 7 patients with a mean time between the second and third sessions of 6.86±5.33 months (1-15 months). Outcome after dilation was successful in 81% of the patients. Of the 140 responders, 121 had complete response (complete disappearance of symptoms without recurrence) and 19 partial response (initial disappearance of symptoms with subsequent reappearance). Surgery (Heller myotomy) was required in 15.8% of the patients. Perforation occurred in 4 of the 171 patients as a complication of the technique; these perforations were satisfactorily resolved, two by conservative treatment and two by surgery. There was no mortality associated with the technique or its complications. In our series, pneumatic dilation had a

  19. Computed tomography of localized dilatation of the intrahepatic bile ducts

    SciTech Connect

    Araki, T.; Itai Y.; Tasaka, A.

    1981-12-01

    Twenty-nine patients showed localized dilatation of the intrahepatic bile ducts on computed tomography, usually unaccompanied by jaundice. Congenital dilatation was diagnosed when associated with a choledochal cyst, while cholangiographic contrast material was helpful in differentiating such dilatation from a simple cyst by showing its communication with the biliary tract when no choledochal cyst was present. Obstructive dilatation was associated with intrahepatic calculi in 4 cases, hepatoma in 9, cholangioma in 5, metastatic tumor in 5, and polycystic disease in 2. Cholangioma and intrahepatic calculi had a greater tendency to accompany such localized dilatation; in 2 cases, the dilatation was the only clue to the underlying disorder.

  20. Charged dilation black holes as particle accelerators

    NASA Astrophysics Data System (ADS)

    Pradhan, Parthapratim

    2015-03-01

    We examine the possibility of arbitrarily high energy in the center-of-mass (CM) frame of colliding neutral particles in the vicinity of the horizon of a charged dilation black hole (BH). We show that it is possible to achieve the infinite energy in the background of the dilation black hole without fine-tuning of the angular momentum parameter. It is found that the CM energy (Ecm) of collisions of particles near the infinite red-shift surface of the extreme dilation BHs are arbitrarily large while the non-extreme charged dilation BHs have the finite energy. We have also compared the Ecm at the horizon with the ISCO (Innermost Stable Circular Orbit) and MBCO (Marginally Bound Circular Orbit) for extremal Reissner-Nordstrøm (RN) BH and Schwarzschild BH. We find that for extreme RN BH the inequality becomes Ecm|r+ >Ecm|rmb >Ecm|rISCO i.e. Ecm|r+=M :Ecm | rmb =(3 +√{ 5 }/2) M :Ecm| rISCO = 4 M = ∞ : 3.23 : 2.6 . While for Schwarzschild BH the ratio of CM energy is Ecm| r+ = 2 M :Ecm| rmb = 4 M :Ecm| rISCO = 6 M =√{ 5 } :√{ 2 } :√{ 13 }/3 . Also for Gibbons-Maeda-Garfinkle-Horowitz-Strominger (GMGHS) BHs the ratio is being Ecm| r+ = 2 M :Ecm| rmb = 2 M :Ecm| rISCO = 2 M = ∞ : ∞ : ∞ .

  1. Genetics Home Reference: familial dilated cardiomyopathy

    MedlinePlus

    ... 10.1056/NEJMoa1110186. Citation on PubMed or Free article on PubMed Central Hershberger RE, Hedges DJ, Morales A. Dilated cardiomyopathy: the complexity of a diverse genetic architecture. Nat Rev Cardiol. 2013 Sep;10(9):531- ...

  2. Stability under dilations of nonlinear spinor fields

    NASA Astrophysics Data System (ADS)

    Strauss, Walter A.; Vázquez, Luis

    1986-07-01

    The stability problem of the localized solutions for classical Dirac fields with scalar self-interactions is considered in the framework of the Shatah-Strauss formalism. We study the stability and instability under dilations and provide an application to the Soler model.

  3. Stability under dilations of nonlinear spinor fields

    SciTech Connect

    Strauss, W.A.; Va-acute-accentzquez, L.

    1986-07-15

    The stability problem of the localized solutions for classical Dirac fields with scalar self-interactions is considered in the framework of the Shatah-Strauss formalism. We study the stability and instability under dilations and provide an application to the Soler model.

  4. Hypnoanalgesia for Dilatation and Curettage Pain Control

    PubMed Central

    Fathi, Mehdi; Aziz Mohammadi, Susan; Moslemifar, Mehdi; Kamali, Kurosh; Joudi, Marjan; Sabri Benhangi, Azam; Mohaddes, Mojtaba; Joudi, Mona; Mohajeri, Mozhgan

    2017-01-01

    There are many acceptable approaches ranging from light to moderate intravenous sedation or analgesic drugs that are used to provide pain control in dilatation and curettage. We report the use of hypnosis as a nonpharmacologic approach to control pain in this manner. PMID:28824863

  5. 21 CFR 874.3900 - Nasal dilator.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES EAR, NOSE, AND THROAT DEVICES Prosthetic Devices § 874.3900 Nasal dilator. (a) Identification. A nasal... nasal airflow. The device decreases airway resistance and increases nasal airflow. The external...

  6. 21 CFR 874.3900 - Nasal dilator.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES EAR, NOSE, AND THROAT DEVICES Prosthetic Devices § 874.3900 Nasal dilator. (a) Identification. A nasal... nasal airflow. The device decreases airway resistance and increases nasal airflow. The external...

  7. 21 CFR 876.5520 - Urethral dilator.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Urethral dilator. 876.5520 Section 876.5520 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL... flexibilities. The device may include a mechanism to expand the portion of the device in the urethra...

  8. 21 CFR 876.5520 - Urethral dilator.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Urethral dilator. 876.5520 Section 876.5520 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL... flexibilities. The device may include a mechanism to expand the portion of the device in the urethra...

  9. Slip and Dilation Tendency Analysis of the Patua Geothermal Area

    DOE Data Explorer

    Faulds, James E.

    2013-12-31

    Critically stressed fault segments have a relatively high likelihood of acting as fluid flow conduits (Sibson, 1994). As such, the tendency of a fault segment to slip (slip tendency; Ts; Morris et al., 1996) or to dilate (dilation tendency; Td; Ferrill et al., 1999) provides an indication of which faults or fault segments within a geothermal system are critically stressed and therefore likely to transmit geothermal fluids. The slip tendency of a surface is defined by the ratio of shear stress to normal stress on that surface: Ts = τ / σn (Morris et al., 1996). Dilation tendency is defined by the stress acting normal to a given surface: Td = (σ1-σn) / (σ1-σ3) (Ferrill et al., 1999). Slip and dilation were calculated using 3DStress (Southwest Research Institute). Slip and dilation tendency are both unitless ratios of the resolved stresses applied to the fault plane by ambient stress conditions. Values range from a maximum of 1, a fault plane ideally oriented to slip or dilate under ambient stress conditions to zero, a fault plane with no potential to slip or dilate. Slip and dilation tendency values were calculated for each fault in the focus study areas at, McGinness Hills, Neal Hot Springs, Patua, Salt Wells, San Emidio, and Tuscarora on fault traces. As dip is not well constrained or unknown for many faults mapped in within these we made these calculations using the dip for each fault that would yield the maximum slip tendency or dilation tendency. As such, these results should be viewed as maximum tendency of each fault to slip or dilate. The resulting along-fault and fault-to-fault variation in slip or dilation potential is a proxy for along fault and fault-to-fault variation in fluid flow conduit potential. Stress Magnitudes and directions Stress field variation within each focus area was approximated based on regional published data and the world stress database (Hickman et al., 2000; Hickman et al., 1998 Robertson-Tait et al., 2004; Hickman and Davatzes

  10. Esophageal dilation in head and neck cancer patients: A systematic review and meta-analysis.

    PubMed

    Moss, William J; Pang, John; Orosco, Ryan K; Weissbrod, Philip A; Brumund, Kevin T; Weisman, Robert A; Brigger, Matthew T; Coffey, Charles S

    2017-05-12

    To characterize the safety profile and effectiveness of esophageal dilation in head and neck cancer patients. A systematic review was undertaken for articles reporting outcomes of esophageal dilation in head and neck cancer patients. The Medline, Scopus, Web of Science, and Cochrane databases were searched in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Complications related to esophageal dilation in head and neck cancer patients was the primary outcome of interest. Success rates, demographic data, cancer staging, and treatment data were assessed secondarily. Statistical analyses included both qualitative and quantitative assessments. A limited meta-analysis and pooling of the data was performed using a random effects model. Of the collective 8,243 initial candidate articles, 15 retrospective studies containing data for a collective 449 patients were ultimately included in the analysis. There was significant heterogeneity in the outcomes data. With an overall complication rate of 10.6% (95% confidence interval [CI]: 4.1%,17%) and a pooled success rate of 72.9% (95% CI: 65.7%,80.1%) per patient, the articles generally supported the use of dilation. Head and neck cancer patients experience a higher rate of complications following dilation compared to patients with other causes of benign stricture. Esophageal dilation is effective in improving dysphagia, but these benefits are often transient and thus necessitate repeat interventions. Laryngoscope, 2017. © 2017 The American Laryngological, Rhinological and Otological Society, Inc.

  11. Tracheobronchial laceration after balloon dilation for benign strictures: incidence and clinical significance.

    PubMed

    Kim, Jin Hyoung; Shin, Ji Hoon; Song, Ho-Young; Shim, Tae Sun; Ko, Gi-Young; Yoon, Hyun-Ki; Sung, Kyu-Bo

    2007-04-01

    Although balloon dilation is a safe procedure, it can lead to laceration of the airway, causing bleeding, pneumothorax, pneumomediastinum, or mediastinitis. We therefore determined the incidence and clinical significance of tracheobronchial lacerations after balloon dilation for treatment of benign tracheobronchial strictures. We evaluated 97 patients who had undergone balloon dilation in 124 sessions for the treatment of benign tracheobronchial strictures. The degree of airway laceration was evaluated bronchoscopically. The cumulative airway patency rate after balloon dilation was compared in patients with and without lacerations using Kaplan-Meier survival curves and log-rank testing. There were 64 tracheobronchial lacerations (51.6%) during the 124 sessions of balloon dilation. Of these, 60 were superficial and 4 were deep, but there were no incidents of transmural laceration. In patients with lacerations, mild chest pain (n = 5), blood-tinged sputum (n = 21), and pneumomediastinum (n = 2) occurred, but all resolved completely within 24 h. All superficial lacerations healed spontaneously within 1 month, and all deep lacerations healed 2 to 9 months after conservative treatment. During the follow-up period, the median cumulative airway patency period in patients with and without lacerations was 24 and 4 months (p < 0.05), respectively. Laceration secondary to balloon dilation in the tracheobronchial tree is relatively common but rarely progresses to transmural laceration and may improve patency outcomes.

  12. Endoscopic minor papilla balloon dilation for the treatment of symptomatic pancreas divisum.

    PubMed

    Yamamoto, Natsuyo; Isayama, Hiroyuki; Sasahira, Naoki; Tsujino, Takeshi; Nakai, Yousuke; Miyabayashi, Koji; Mizuno, Suguru; Kogure, Hirofumi; Sasaki, Takashi; Hirano, Kenji; Tada, Minoru; Koike, Kazuhiko

    2014-08-01

    A subpopulation of patients with pancreas divisum experience symptomatic events such as recurrent acute pancreatitis and chronic pancreatitis. Minor papilla sphincterotomy has been reported as being an effective treatment. The aim of this study was to evaluate the safety and efficacy of endoscopic balloon dilation for the minor papilla. Between 2000 and 2012, 16 patients were retrospectively included in this study. After endoscopic balloon dilation for the minor papilla was received, a pancreatic stent or a nasal pancreatic drainage catheter was placed for 1 week. If a stricture or obstruction was evident, it was treated with balloon dilation followed by long-term stent placement (1 year). When an outflow of pancreatic juice was disturbed by a pancreatic stone, endoscopic stone extraction was performed. Balloon dilation and stent placement were achieved and were successful in all the cases (16/16; 100%). Clinical improvement was achieved in 7 (84.7%) of the 9 patients with recurrent acute pancreatitis and in 6 (85.7%) of the 7 patients with chronic pancreatitis. Early complications were observed in 1 (6.3%) patient. Pancreatitis or bleeding related to balloon dilation was not observed. Endoscopic balloon dilation for the minor papilla is feasible for the management of symptomatic pancreas divisum.

  13. Delayed brachial artery dilation response and increased resting blood flow velocity in young children with mild sleep-disordered breathing.

    PubMed

    Kontos, Anna; van den Heuvel, Cameron; Pamula, Yvonne; Martin, James; Lushington, Kurt; Baumert, Mathias; Willoughby, Scott; Gent, Roger; Couper, Jenny; Kennedy, Declan

    2015-12-01

    This study aimed to evaluate whether the vascular dysfunction perceived in adults with sleep-disordered breathing (SDB) was also evident in children with snoring referred for evaluation of clinically suspected SDB. This study compared flow-mediated dilatation (FMD), measured at the brachial artery, at rest and during hyperaemic stress between children who snore [n = 23; mean standard deviation (SD) age = 7.51 (1.3) years] and healthy, non-snoring children [n = 11; age = 8.0 (1.3) years]. Children with suspected obstructive sleep apnoea (OSA) and healthy non-snoring controls underwent overnight polysomnography (PSG). Using standard techniques, non-invasive FMD and brachial arterial blood flow velocity during rest and hyperaemia were subsequently measured by ultrasound imaging Resting and hyperaemic velocity time integral (area under the curve of mean systolic velocity × ejection time), maximal dilation response (highest percentage difference from baseline diameter) and the time taken to reach maximal dilation were calculated. Children awaiting adenotonsillectomy compared to healthy non-snoring control children had higher velocity time integrals at rest (14 ± 3 m vs. 20 ± 8 m, p < 0.01) and during hyperaemic stress (56 ± 6m vs. 63 ± 13m, p < 0.01) despite having only mild SDB on polysomnographic assessment. Lower nadir oxygen saturation values during non-rapid eye movement sleep were negatively associated with higher resting (r = -0.58, p <0.001) and hyperaemic (r = -0.36, p < 0.05) velocity time integrals. Maximal FMD dilatation response was not significantly different between snoring and non-snoring groups, but the estimated time to reach maximal dilation was significantly delayed in children who snored (60.7 ± 28.4 vs. 39.2 ± 13.2 s, p < 0.05). Children with mild SDB showed increased blood flow velocity at rest and during hyperaemic stress suggesting altered cardiovascular and

  14. Arterial microembolisation: an unusual presentation of dilated cardiomyopathy.

    PubMed Central

    Gillespie, R L; Mullen, G M; Costanzo-Nordin, M R

    1990-01-01

    Systemic embolisation is common in patients with dilated cardiomyopathy. Microembolisation as a presenting sign of dilated cardiomyopathy, however, has not been reported before. A 37 year old woman in whom dilated cardiomyopathy presented as arterial microembolisation to the toes is described. Images PMID:2310647

  15. Dilated cardiomyopathy in acromegaly: Case report and anesthesia management

    PubMed Central

    Nair, Abhijit S.; Nirale, Anand M.; Sriprakash, K.; Gopal, T. V. S.

    2013-01-01

    Patients who are diagnosed having acromegaly develop a lot of cardiovascular Complications such as hypertension, arrhythmias, systolic and diastolic dysfunction, valvular dysfunction and heart failure. Dilated cardiomyopathy (DCM) with systolic and diastolic dysfunction is relatively rare but is associated with an increased mortality. We report a case of acromegaly diagnosed at 52 years of age in a known diabetic, non-hypertensive male who had DCM with severe left ventricular dysfunction, global hypokinesia, moderate mitral regurgitation, and grade II diastolic dysfunction who was treated with diuretics, digitalis, and vasodilators. He was diagnosed with a growth hormone secreting pituitary macroadenoma and underwent endoscopic excision of the pituitary tumor under general anesthesia. PMID:25885996

  16. Assessment of artery dilation by using image registration based on spatial features

    NASA Astrophysics Data System (ADS)

    Oubel, Estanislao; Neemuchwala, Huzefa; Hero, Alfred; Boisrobert, Loic; Laclaustra, Martin; Frangi, Alejandro F.

    2005-04-01

    The use of affine image registration based on normalized mutual information (NMI) has recently been proposed by Frangi et al. as an automatic method for assessing brachial artery flow mediated dilation (FMD) for the characterization of endothelial function. Even though this method solves many problems of previous approaches, there are still some situations that can lead to misregistration between frames, such as the presence of adjacent vessels due to probe movement, muscle fibres or poor image quality. Despite its widespread use as a registration metric and its promising results, MI is not the panacea and can occasionally fail. Previous work has attempted to include spatial information into the image similarity metric. Among these methods the direct estimation of alpha-MI through Minimum Euclidean Graphs allows to include spatial information and it seems suitable to tackle the registration problem in vascular images, where well oriented structures corresponding to vessel walls and muscle fibres are present. The purpose of this work is twofold. Firstly, we aim to evaluate the effect of including spatial information in the performance of the method suggested by Frangi et al. by using alpha-MI of spatial features as similarity metric. Secondly, the application of image registration to long image sequences in which both rigid motion and deformation are present will be used as a benchmark to prove the value of alpha-MI as a similarity metric, and will also allow us to make a comparative study with respect to NMI.

  17. Specific mitochondrial DNA deletions in idiopathic dilated cardiomyopathy.

    PubMed

    Marin-Garcia, J; Goldenthal, M J; Ananthakrishnan, R; Pierpont, M E; Fricker, F J; Lipshultz, S E; Perez-Atayde, A

    1996-02-01

    Structural changes in human mitochondrial DNA (mtDNA) have been implicated in a number of clinical conditions with dysfunctions in oxidative phosphorylation called OX-PHOS diseases, some of which have cardiac involvement. The objective of this study was to assess the frequency and extent of specific mitochondrial DNA deletions in idiopathic dilated cardiomyopathy. DNA extracted from tissue derived from the left ventricle of 41 patients with idiopathic dilated cardiomyopathy and 17 controls was amplified by polymerase chain reaction using specific primers to assess the incidence and proportion of 5-kb and 7.4-kb deletions in mitochondrial DNA. In reactions using primers to detect the 5-kb deletion, an amplified product of 593 bp was found in low abundance relative to undeleted mitochondrial DNA but with high frequency in a number of controls and patients. A second deletion of 7.4 kb in size was also frequently present in controls and patients. In contrast to previous reports, these deletions were found to be present in both controls and in cardiomyopathic patients, 18 years and younger, including several infants. The 7.4-kb deletion was prominently increased in both frequency and in its proportion relative to undeleted mitochondrial DNA in patients 40 years and older with idiopathic dilated cardiomyopathy. At variance with current literature our study reports a significant presence of both 5 and 7.4-kb deletions in the young and a higher frequency and quantity of the 7.4-kb deletion in the older cardiomyopathic patients in comparison with controls. The increased accumulation of the 7.4-kb deletion as both a function of aging and cardiomyopathy is suggestive that this specific mitochondrial DNA deletion arises more likely as an effect of heart dysfunction rather than as a primary cause of cardiomyopathy.

  18. Electrocardiography during Manual Dilatation of the Anus

    PubMed Central

    Collins, R. E. C.; Fell, R. H.; Lord, P. H.

    1973-01-01

    Manual dilatation of the anus was carried out on 50 unpremedicated outpatients under propanidid, nitrous oxide, and halothane anaesthesia with E.C.G.monitoring. About half of the patients received intravenous atropine with the propanidid. The operation induced a variety of changes in heart rate but in the whole experiment only two isolated cardiac arrhythmic complexes were seen—a single defect of conduction and a solitary ventricular extrasystole. Changes in rate were not modified by atropine. It is concluded that manual dilatation of the anus is a safe procedure when carried out under the anaesthetic described and that prior medication with atropine is not necessary. This work supports the view that propanidid protects patients from most abnormalities of heart action which result from intense visceral stimulation. PMID:4712484

  19. Sheehan syndrome with reversible dilated cardiomyopathy.

    PubMed

    Laway, Bashir A; Alai, Mohammad S; Gojwari, Tariq; Ganie, Mohd A; Zargar, Abdul Hamid

    2010-01-01

    Cardiac abnormalities in patients with Sheehan syndrome are uncommon. A case of Sheehan syndrome with dilated cardiomyopathy is presented in whom hormone replacement with levothyroxine and prednisolone resulted in complete recovery of cardiomyopathy. A 25-year-old woman presented with lactation failure, secondary amenorrhea, features of hypothyroidism and a hypocortisol state following severe postpartum hemorrhage after her last child birth. She also had smear positive pulmonary tuberculosis. After starting antitubercular treatment, she developed shock, suggestive of hypocortisol crisis. Hormonal investigations revealed evidence of panhypopitutarism and magnetic resonance imaging revealed partial empty sella. Meanwhile echocardiography revealed evidence of dilated cardiomyopathy (DCM). The patient was given replacement therapy in the form of glucocorticoids and levothyroxine in addition to antitubercular treatment. She improved and on follow-up over a period of 7 months, the DCM completely reversed. To our knowledge this is the first report of reversible DCM in a patient with Sheehan syndrome.

  20. Shear-induced dilatancy of fluid-saturated faults: Experiment and theory

    NASA Astrophysics Data System (ADS)

    Samuelson, Jon; Elsworth, Derek; Marone, Chris

    2009-12-01

    Pore fluid pressure plays an important role in the frictional strength and stability of tectonic faults. We report on laboratory measurements of porosity changes associated with transient increases in shear velocity during frictional sliding within simulated fine-grained quartz fault gouge (d50 = 127 μm). Experiments were conducted in a novel true triaxial pressure vessel using the double-direct shear geometry. Shearing velocity step tests were used to measure a dilatancy coefficient (ɛ = Δϕ/Δln(v), where ϕ is porosity and v is shear velocity) under a range of conditions: background shearing rate of 1 μm/s with steps to 3, 10, 30, and 100 μm/s at effective normal stresses from 0.8 to 20 MPa. We find that the dilatancy coefficient ranges from 4.7 × 10-5 to 3.0 × 10-4 and that it does not vary with effective normal stress. We use our measurements to model transient pore fluid depressurization in response to dilation resulting from step changes in shearing velocity. Dilatant hardening requires undrained response with the transition from drained to undrained loading indexed by the ratio of the rate of porosity change to the rate of drained fluid loss. Undrained loading is favored for high slip rates on low-permeability thick faults with low critical slip distances. Although experimental conditions indicate negligible depressurization due to relatively high system permeability, model results indicate that under feasible, but end-member conditions, shear-induced dilation of fault zones could reduce pore pressures or, correspondingly, increase effective normal stresses, by several tens of megapascals. Our results show that transient increases in shearing rate cause fault zone dilation. Such dilation would tend to arrest nucleation of unstable slip. Pore fluid depressurization would exacerbate this effect and could be a significant factor in generation of slow earthquakes, nonvolcanic tremors, and related phenomena.

  1. Improved Model of Rock Mass Dilatation.

    DTIC Science & Technology

    1985-05-29

    nonlinear partial differential equations of the hyperbolic type is involved. In both cases, the numerical procedures are discussed in detail : Runge-Kutta...34 ... .. .. .. ’ ................... ":"’’t_ . 2 Geometrical interpretation of the coefficient of friction p and the dilatancy factor 9.....9 3 Variable flow rule, characterized by a...increase of the crack space (porosity) but also by sliding along intergranular surfaces (cataclastic flow ). .- .. At high confining pressure

  2. Charged Dilation Black Holes as Particle Accelerators

    NASA Astrophysics Data System (ADS)

    Pradhan, Parthapratim

    2016-07-01

    We examine the possibility of arbitrarily high energy in the Center-of-mass frame of colliding neutral particles in the vicinity of the horizon of a charged dilation black hole(BH). We show that it is possible to achieve the infinite energy in the background of the dilation black hole without fine-tuning of the angular momentum parameter. It is found that the center-of-mass energy (E_{cm}) of collisions of particles near the infinite red-shift surface of the extreme dilation BHs are arbitrarily large while the non-extreme charged dilation BHs have the finite energy. We have also compared the E_{cm} at the horizon with the ISCO(Innermost Stable Circular Orbit) and MBCO (Marginally Bound Circular Orbit) for extremal RN BH and Schwarzschild BH. We find that for extreme RN BH the inequality becomes E_{cm}mid_{r_{+}}>E_{cm}mid_{r_{mb}}> E_{cm}mid_{r_{ISCO}} i.e. E_{cm}mid_{r_{+}=M}: E_{cm}mid_{r_{mb}= ({3+√{5}}/{2})M} : E_{cm}mid_{r_{ISCO}=4M} =∞ : 3.23 : 2.6 . While for Schwarzschild BH the ratio of CM energy is E_{cm}mid_{r_{+}=2M}: E_{cm}mid_{r_{mb}=4M} : E_{cm}mid_{r_{ISCO}=6M} = √{5} : √{2} : {√{13}}/{3}. Also for Gibbons-Maeda-Garfinkle-Horowitz-Strominger (GMGHS) BHs the ratio is being E_{cm}mid_{r_{+}=2M}: E_{cm}mid_{r_{mb}=2M} : E_{cm}mid_{r_{ISCO}=2M}=∞ : ∞ : ∞.

  3. Dilatancy Instability as a Possible Seismic Mechanism

    DTIC Science & Technology

    1976-06-01

    8217’ 1 I I -- I C=0 Department of Mining Engineering South Dakota School of Mines & Technology Rapid City, South DIlkta 57701 8, 01 08105 FINAL REPORT...Title: Dilatancy Instability as a Possible Seismic Mechanism Principal Investigator: James E. Russell Professor of Mining Engineering South Dakota ...School of Mines & Technology Rapid City, South Dakota 57701 Contract Period: April 10, 1972 to November 30, 1973 Sponsored by: The U. S. Geological Survey

  4. Proventricular dilatation syndrome in large psittacine birds.

    PubMed

    Clark, F D

    1984-01-01

    Proventricular dilatation was diagnosed in 16 psittacine birds. Signs included anorexia, lethargy, weight loss, and intermittent vomiting. The proventriculus in all birds was thin-walled and impacted with ingesta and occupied most of the body cavity. Microscopic changes in the proventriculus varied from none to an infiltration of lymphocytes, macrophages, and heterophils. There was no evidence of viral or bacterial infection or lead toxicity.

  5. A pseudo-sound constitutive relationship for the dilatational covariances in compressible turbulence: An analytical theory

    NASA Technical Reports Server (NTRS)

    Ristorcelli, J. R.

    1995-01-01

    The mathematical consequences of a few simple scaling assumptions about the effects of compressibility are explored using a simple singular perturbation idea and the methods of statistical fluid mechanics. Representations for the pressure-dilation and dilatational dissipation covariances appearing in single-point moment closures for compressible turbulence are obtained. While the results are expressed in the context of a second-order statistical closure they provide some interesting and very clear physical metaphors for the effects of compressibility that have not been seen using more traditional linear stability methods. In the limit of homogeneous turbulence with quasi-normal large-scales the expressions derived are - in the low turbulent Mach number limit - asymptotically exact. The expressions obtained are functions of the rate of change of the turbulence energy, its correlation length scale, and the relative time scale of the cascade rate. The expressions for the dilatational covariances contain constants which have a precise and definite physical significance; they are related to various integrals of the longitudinal velocity correlation. The pressure-dilation covariance is found to be a nonequilibrium phenomena related to the time rate of change of the internal energy and the kinetic energy of the turbulence. Also of interest is the fact that the representation for the dilatational dissipation in turbulence, with or without shear, features a dependence on the Reynolds number. This article is a documentation of an analytical investigation of the implications of a pseudo-sound theory for the effects of compressibility.

  6. Bougie urethral dilators: revival or survival?

    PubMed Central

    Al–Adawi, Mohammad Ahmad

    2013-01-01

    Objectives To present our center's experience in managing bladder outlet obstruction (BOO) conditions using bougie dilators. We described the dilation technique methodically for teaching purpose. Patients and method Retrospectively, a total of 196 medical records over the last four years denoting BOO conditions in men, women, and children were retrieved for analysis. Data reviewed for common complications was namely: perforation, recurrence, urinary tract obstruction (UTI) and inability to overcome the obstruction. Results Among the 196 analyzed cases, 24 (12.2%) cases were cured, whereas 172 (87.8%) cases reported complications. Within the complicated cases analyzed, 134 (68.4%) cases had recurrent obstructions, 13 (6.6%) cases had perforations, 6 (3.0%) cases developed UTI, while in 19 (9.7%) cases, we failed to pass the obstruction. Conclusions In our center where urethral dilation technique has revived four years ago, it turned back to be the standard choice in managing BOO cases. We propose the technique to Urology training program directors, all over the world, to teach it as a compulsory skill for junior urologists to master. PMID:24757552

  7. Dilatancy and shear thickening of particle suspensions

    NASA Astrophysics Data System (ADS)

    Bonn, Daniel

    2013-03-01

    Shear thickening is a fascinating subject, as 99.9% of complex fluids are thinning; thickening systems thus are the ``exception to the rule'' that needs to be understood. Moreover, such tunable systems show very promising applications, e.g. to block large underground pores in oil recovery to maintain a constant oil flow by plugging water filled pores (an approach used in oil recovery by e.g. Shell), or to manufacture bulletproof vests that are comfortable to wear, but stop bullets nonetheless. We study the rheology of non-Brownian particle suspensions (notably, cornstarch) that exhibit shear thickening. Using magnetic resonance imaging (MRI), the local properties of the flow are obtained by the determination of local velocity profiles and concentrations in a Couette cell. We also perform macroscopic rheology experiments in different geometries. The results suggest that the shear thickening is a consequence of dilatancy: the system under flow attempts to dilate but instead undergoes a jamming transition, because it is confined. This proposition is confirmed by an independent measurement of the dilation of the suspension as a function of the shear rate.

  8. Dilational surface rheology of polymer solutions

    NASA Astrophysics Data System (ADS)

    Noskov, B. A.; Bykov, A. G.

    2015-06-01

    The review concerns main achievements in dilational rheology of polymer adsorption films at the gas/liquid interfaces reported in the last fifteen years. The theoretical foundations of methods of surface rheology and the key results obtained in studies of solutions of amphiphilic nonionic polymers, polyelectrolytes, proteins and their complexes with low-molecular-mass surfactants are discussed. Interest in the surface dilational rheology is mainly caused by a small number of available experimental methods for investigation of the surface of liquids, by the fact that traditional methods of measurement of the surface tension that are widely used in studies of solutions of low-molecular-mass surfactants provide little information when applied to polymer solutions owing to very slow establishment of equilibrium as well as by weak dependence of the surface tension on the polymer concentration. Progress in the surface rheology is driven by the recent studies of the stability of foams and emulsions that demonstrated a key role of the dilational surface rheological properties in the dynamics of liquid-phase disperse systems. The bibliography includes 191 references.

  9. Aortic Valve Adaptation to Aortic Root Dilatation

    PubMed Central

    Kim, Dae-Hee; Handschumacher, Mark D.; Levine, Robert A.; Sun, Byung Joo; Jang, Jeong Yoon; Yang, Dong Hyun; Kang, Joon-Won; Song, Jong-Min; Kang, Duk-Hyun; Lim, Tae-Hwan; Song, Jae-Kwan

    2015-01-01

    Background The 3-dimensional relationship between aortic root and cusp is essential to understand the mechanism of aortic regurgitation (AR) because of aortic root dilatation (ARD). We sought to test the hypothesis that the stretched cusps in ARD enlarge to compensate for ARD. Methods and Results Computed tomography imaged 92 patients (57 with ARD, 29 with moderate to severe AR, 28 without significant AR) and 35 normal controls. Specialized 3-dimensional software measured individual cusp surface areas relative to maximal mid-sinus cross-sectional area and minimal 3-dimensional annular area, coaptation area fraction, and asymmetry of sinus volumes and intercommissural distances. Total open cusp surface area increased (P<0.001) from 7.6±1.4 cm2/m2 in normals to 12.9±2.2 cm2/m2 in AR-negative and 15.2±3.3 cm2/m2 in AR-positive patients. However, the ratio of closed cusp surface area to maximal mid-sinus area, reflecting cusp adaptation, decreased from normals to AR-negative to AR-positive patients (1.38±0.20, 1.15±0.15, 0.88±0.15; P<0.001), creating the lowest coaptation area fraction. Cusp distensibility (closed diastolic versus open area) decreased from 20% in controls and AR-negative patients to 5% in AR-positive patients (P<0.001). Multivariate determinants of AR and coaptation area fraction reflected both sinus size and cusp-to-annular adaptation. ARD was also progressively asymmetrical with root size, and individual cusp surface areas failed to match this asymmetry. Conclusions Aortic cusp enlargement occurs in ARD, but cusp adaptation and distensibility become limited in prominent, asymmetrical ARD, leading to AR. Optimal AR repair tailored to individual patient anatomy can benefit from appreciating valve adaptation and 3-dimensional relationships; understanding cusp adaptation mechanisms may ultimately provide therapeutic opportunities to improve such compensation. PMID:25051951

  10. Aortic assessment of bicuspid aortic valve patients and their first-degree relatives.

    PubMed

    Straneo, Pablo; Parma, Gabriel; Lluberas, Natalia; Marichal, Alvaro; Soca, Gerardo; Cura, Leandro; Paganini, Juan J; Brusich, Daniel; Florio, Lucia; Dayan, Victor

    2017-03-01

    Background Bicuspid aortic valve patients have an increased risk of aortic dilatation. A deficit of nitric oxide synthase has been proposed as the causative factor. No correlation between flow-mediated dilation and aortic diameter has been performed in patients with bicuspid aortic valves and normal aortic diameters. Being a hereditary disease, we compared echocardiographic features and endothelial function in these patients and their first-degree relatives. Methods Comprehensive physical examinations, routine laboratory tests, transthoracic echocardiography, and measurements of endothelium-dependent and non-dependent flow-mediated vasodilatation were performed in 18 bicuspid aortic valve patients (14 type 1 and 4 type 2) and 19 of their first-degree relatives. Results The first-degree relatives were younger (36.7 ± 18.8 vs. 50.5 ± 13.9 years, p = 0.019) with higher ejection fractions (64.6% ± 1.7% vs. 58.4% ± 9.5%, p = 0.015). Aortic diameters indexed to body surface area were similar in both groups, the except the tubular aorta which was larger in bicuspid aortic valve patients (19.3 ± 2.7 vs. 17.4 ± 2.2 mm·m(-2), p = 0.033). Flow-dependent vasodilation was similar in both groups. A significant inverse correlation was found between non-flow-dependent vasodilation and aortic root diameter in patients with bicuspid aortic valve ( R = -0.57, p = 0.05). Conclusions Bicuspid aortic valve patients without aortopathy have larger ascending aortic diameters than their first-degree relatives. Endothelial function is similar in both groups, and there is no correlation with ascending aorta diameter. Nonetheless, an inverse correlation exists between non-endothelial-dependent dilation and aortic root diameter in bicuspid aortic valve patients.

  11. Stress-Dilatancy for Soils. Part II: Experimental Validation for Triaxial Tests

    NASA Astrophysics Data System (ADS)

    Szypcio, Zenon

    2016-12-01

    Different forms of the stress-dilatancy relations obtained based on the frictional theory for the triaxial condition are presented. The analysed test data show that the shear resistance of many soils is purely frictional. The angle Φ0 represents the resistance of the soil as a combined effect of sliding and particle rolling on the macro-scale during shear at the critical frictional state. The stress-plastic dilatancy relations differ not only for triaxial compression and extension but also for drained and undrained conditions. The experiment investigated shows the correctness of the frictional state theory in the triaxial condition.

  12. Cognitive effort and pupil dilation in controlled and automatic processes.

    PubMed

    Querino, Emanuel; Dos Santos, Lafaiete; Ginani, Giuliano; Nicolau, Eduardo; Miranda, Débora; Romano-Silva, Marco; Malloy-Diniz, Leandro

    2015-01-01

    The Five Digits Test (FDT) is a Stroop paradigm test that aims to evaluate executive functions. It is composed of four parts, two of which are related to automatic and two of which are related to controlled processes. It is known that pupillary diameter increases as the task's cognitive demand increases. In the present study, we evaluated whether the pupillary diameter could distinguish cognitive effort between automated and controlled cognitive processing during the FDT as the task progressed. As a control task, we used a simple reading paradigm with a similar visual aspect as the FDT. We then divided each of the four parts into two blocks in order to evaluate the differences between the first and second half of the task. Results indicated that, compared to a control task, the FDT required higher cognitive effort for each consecutive part. Moreover, the first half of every part of the FDT induced dilation more than the second. The differences in pupil dilation during the first half of the four FDT parts were statistically significant between the parts 2 and 4 (p=0.023), and between the parts 3 and 4 (p=0.006). These results provide further evidence that cognitive effort and pupil diameter can distinguish controlled from automatic processes.

  13. Cognitive effort and pupil dilation in controlled and automatic processes

    PubMed Central

    Querino, Emanuel; dos Santos, Lafaiete; Ginani, Giuliano; Nicolau, Eduardo; Miranda, Débora; Romano-Silva, Marco; Malloy-Diniz, Leandro

    2015-01-01

    The Five Digits Test (FDT) is a Stroop paradigm test that aims to evaluate executive functions. It is composed of four parts, two of which are related to automatic and two of which are related to controlled processes. It is known that pupillary diameter increases as the task’s cognitive demand increases. In the present study, we evaluated whether the pupillary diameter could distinguish cognitive effort between automated and controlled cognitive processing during the FDT as the task progressed. As a control task, we used a simple reading paradigm with a similar visual aspect as the FDT. We then divided each of the four parts into two blocks in order to evaluate the differences between the first and second half of the task. Results indicated that, compared to a control task, the FDT required higher cognitive effort for each consecutive part. Moreover, the first half of every part of the FDT induced dilation more than the second. The differences in pupil dilation during the first half of the four FDT parts were statistically significant between the parts 2 and 4 (p=0.023), and between the parts 3 and 4 (p=0.006). These results provide further evidence that cognitive effort and pupil diameter can distinguish controlled from automatic processes. PMID:28123801

  14. Dilated cardiomyopathy secondary to chronic cocaine abuse: a case report.

    PubMed

    Cooper, Chad J; Said, Sarmad; Alkhateeb, Haider; Rodriguez, Emmanuel; Trien, Remi; Ajmal, Shajeea; Blandon, Pedro A; Hernandez, German T

    2013-12-17

    Cocaine is a potent sympathomimetic agent associated with the development of possible fatal cardiovascular complications. Dysrhythmias, acute myocardial infarction, hypertension and dilated cardiomyopathy are just some of many cardiovascular effects related to the abuse of cocaine. A 38-year-old Hispanic male with a past medical history of hypertension presented with a chief complaint of progressive shortness of breath. The patient confessed to the use of cocaine for almost 18 years once per week. On examination he was hypertensive and tachycardic with a systolic murmur over the 5th intercostal space at the level of the left mid-clavicular line. Laboratory workup revealed an elevated Brain natriuretic peptide; urine toxicology was positive for cocaine. 2D-echocardiogram showed dilated cardiomyopathy. Cardiac catheterization excluded angioischemic cause. He was managed medically and subsequently discharged with drug rehabilitation. On follow-up diagnostic evaluation after 5 months of cocaine cessation, his ejection function improved significantly. The exact incidence of cocaine related cardiomyopathy is unknown and likely underreported. The clinical course is abrupt and comparatively similar to other types of cardiomyopathy. The management is like other forms of cardiomyopathy; however β-blockers should be avoided. The myocardial dysfunction is reversible with abstaining from additional cocaine ingestion. Non-invasive testing should be performed after several months to re-evaluate the treatment response.

  15. Measurement-induced-nonlocality for Dirac particles in Garfinkle-Horowitz-Strominger dilation space-time

    NASA Astrophysics Data System (ADS)

    He, Juan; Xu, Shuai; Ye, Liu

    2016-05-01

    We investigate the quantum correlation via measurement-induced-nonlocality (MIN) for Dirac particles in Garfinkle-Horowitz-Strominger (GHS) dilation space-time. It is shown that the physical accessible quantum correlation decreases as the dilation parameter increases monotonically. Unlike the case of scalar fields, the physical accessible correlation is not zero when the Hawking temperature is infinite owing to the Pauli exclusion principle and the differences between Fermi-Dirac and Bose-Einstein statistics. Meanwhile, the boundary of MIN related to Bell-violation is derived, which indicates that MIN is more general than quantum nonlocality captured by the violation of Bell-inequality. As a by-product, a tenable quantitative relation about MIN redistribution is obtained whatever the dilation parameter is. In addition, it is worth emphasizing that the underlying reason why the physical accessible correlation and mutual information decrease is that they are redistributed to the physical inaccessible regions.

  16. Consistency of time dilation in temporal profiles and spectra of gamma-ray bursts

    NASA Technical Reports Server (NTRS)

    Noriss, J. P.; Nemiroff, R. J.; Bonnell, J. T.; Scargle, J. D.; Davis, S. P.; Kouveliotou, C.; Pendleton, G.; Fishman, G. J.; Meegan, C. A.; Paciesas, W. S.

    1995-01-01

    If gamma-ray bursters are at cosmological distances-a possibility suggested by their isotropic distribution and spatial inhomogeneity-then the temporal profiles and spectra of more distant sources will be time dilated compared to those of relatively nearby sources. Analyses of bright and dim Burst and Transient Source Experiment (BATSE) gamma-ray bursts yield a relative time-dilation factor of 2.3 on timescales of pulses and event durations. We redshift the spectra of time intervals near the intensity peaks of the bright sample on a trial grid and compare with spectra of the dim sample. A redshift factor of order two-with wide latitude permitted-brings the spectra of the two brightness groups into alignment. Thus there is coarse agreement with the time-dilation factor found in the temporal domain.

  17. Long term survival effect of metoprolol in dilated cardiomyopathy

    PubMed Central

    Di, L; De Maria, R; Gavazzi, A; Gregori, D; Parolini, M; Sinagra, G; Salvatore, L; Longaro, F; Bernobich, E; Camerini, F

    1998-01-01

    Objective—To evaluate the additive effect of metoprolol treatment on long term incidence of fatal and non-fatal cardiac events in idiopathic dilated cardiomyopathy.
Design—586 patients with idiopathic dilated cardiomyopathy were prospectively enrolled in a multicentre registry and followed up for a mean (SD) of 52 (32) months. Metoprolol, carefully titrated to the maximum tolerated dose, was added to conventional heart failure treatment in 175 patients.
Results—Survival and transplant-free survival at seven years were significantly higher in the 175 metoprolol treated patients than in the remaining 411 on standard treatment (81% v 60%, p < 0.001, and 69% v 49%, p < 0.001, respectively). By multivariate analysis, metoprolol independently predicted survival and transplant-free survival (relative risk reduction values for all cause mortality and combined mortality or transplantation 51% (95% confidence interval 21% to 69%), p = 0.002, and 34% (5% to 53%), p = 0.01, respectively). New York Heart Association class, left ventricular end diastolic diameter, and pulmonary wedge pressure were also predictive. Seven year survival (80% v 62%, p = 0.004) and transplant-free survival (68% v 51%, p = 0.005) were significantly higher in 127 metoprolol treated cases than in 127 controls selected from the entire control cohort and appropriately matched. Metoprolol was associated with a 30% reduction in all cause mortality (7% to 48%, p = 0.015) and a 26% reduction in mortality or transplantation (7% to 41%, p = 0.009). 
Conclusions—The addition of metoprolol to standard heart failure treatment, including angiotensin converting enzyme inhibitors, was effective in the long term, reducing both all cause mortality and transplantation in patients with idiopathic dilated cardiomyopathy.

 Keywords: β blockade;  dilated cardiomyopathy;  heart failure PMID:9616339

  18. Chlamydia muridarum Induction of Glandular Duct Dilation in Mice

    PubMed Central

    Sun, Xin; Yang, Zhangsheng; Zhang, Hongbo; Dai, Jin; Chen, Jianlin; Tang, Lingli; Rippentrop, Sheena; Xue, Min

    2015-01-01

    Although Chlamydia-induced hydrosalpinx in women and mice has been used as a surrogate marker for tubal infertility, the medical relevance of nontubal pathologies, such as uterine horn dilation, developed in mice following chlamydial infection remains unclear. We now report that the uterine horn dilation correlates with glandular duct dilation detected microscopically following Chlamydia muridarum infection. The dilated glandular ducts pushed the uterine horn lumen to closure or dilation and even broke through the myometrium to develop extrusion outside the uterine horn. The severity scores of uterine horn dilation observed macroscopically correlated well with the number of cross sections of the dilated glandular ducts counted under microscopy. Chlamydial infection was detected in the glandular epithelial cells, potentially leading to inflammation and dilation of the glandular ducts. Direct delivery of C. muridarum into the mouse uterus increased both uterine horn/glandular duct dilation and hydrosalpinx. However, the chlamydial plasmid, which is essential for the induction of hydrosalpinx, was not required for the induction of uterine horn/glandular duct dilation. Screening 12 strains of mice for uterine horn dilation following C. muridarum infection revealed that B10.D2, C57BL/10J, and C57BL/6J mice were most susceptible, followed by BALB/cJ and A/J mice. Deficiency in host genes involved in immune responses failed to significantly alter the C. muridarum induction of uterine horn dilation. Nevertheless, the chlamydial induction of uterine horn/glandular duct dilation may be used to evaluate plasmid-independent pathogenicity of Chlamydia in susceptible mice. PMID:25824829

  19. Is endoscopic papillary balloon dilatation really a risk factor for post-ERCP pancreatitis?

    PubMed Central

    Fujisawa, Toshio; Kagawa, Koichi; Hisatomi, Kantaro; Kubota, Kensuke; Nakajima, Atsushi; Matsuhashi, Nobuyuki

    2016-01-01

    Endoscopic papillary balloon dilatation (EPBD) is useful for decreasing early complications of endoscopic retrograde cholangio-pancreatography (ERCP), including bleeding, biliary infection, and perforation, but it is generally avoided in Western countries because of a relatively high reported incidence of post-ERCP pancreatitis (PEP). However, as the efficacy of endoscopic papillary large-balloon dilatation (EPLBD) becomes widely recognized, EPBD is attracting attention. Here we investigate whether EPBD is truly a risk factor for PEP, and seek safer and more effective EPBD procedures by reviewing past studies. We reviewed thirteen randomised control trials comparing EPBD and endoscopic sphincterotomy (EST) and ten studies comparing direct EPLBD and EST. Three randomized controlled trials of EPBD showed significantly higher incidence of PEP than EST, but no study of EPLBD did. Careful analysis of these studies suggested that longer and higher-pressure inflation of balloons might decrease PEP incidence. The paradoxical result that EPBD with small-calibre balloons increases PEP incidence while EPLBD does not may be due to insufficient papillary dilatation in the former. Insufficient dilatation could cause the high incidence of PEP through the use of mechanical lithotripsy and stress on the papilla at the time of stone removal. Sufficient dilation of the papilla may be useful in preventing PEP. PMID:27468185

  20. Pupil dilation reveals top-down attentional load during spatial monitoring.

    PubMed

    Lisi, Matteo; Bonato, Mario; Zorzi, Marco

    2015-12-01

    It has long been known that the diameter of human pupil enlarges with increasing effort during the execution of a task. This has been observed not only for purely mechanical effort but also for mental effort, as for example the computation of arithmetic problems with different levels of difficulty. Here we show that pupil dilation reflects changes in visuospatial awareness induced by attentional load during multi-tasking. In the single-task condition, participants had to report the position of lateralized, briefly presented, masked visual targets ("right", "left", or "both" sides). In the multitasking conditions, participants also performed additional tasks, either visual or auditory, to increase the attentional load. Sensory stimulation was kept constant across all conditions to rule out the influence of low-level factors. Results show that event-related pupil dilation strikingly increased with task demands, mirroring a concurrent decrease in visuospatial awareness. Importantly, pupil dilation significantly differed between two dual-task conditions that required to process the same number of stimuli but yielded differed levels of accuracy (difficulty). In contrast, pupil dilation did not differ between two conditions which were equally challenging but differed both in the modality of the dual task (auditory vs. visual) and in the number of stimuli to be attended. We conclude that pupil dilation genuinely reflects the top-down allocation of supramodal attentional resources.

  1. Suppression of slip and rupture velocity increased by thermal pressurization: Effect of dilatancy

    NASA Astrophysics Data System (ADS)

    Urata, Yumi; Kuge, Keiko; Kase, Yuko

    2013-11-01

    investigated the effect of dilatancy on dynamic rupture propagation on a fault where thermal pressurization (TP) is in effect, taking into account permeability varying with porosity; the study is based on three-dimensional (3-D) numerical simulations of spontaneous ruptures obeying a slip-weakening friction law and Coulomb failure criterion. The effects of dilatancy on dynamic ruptures interacting with TP have been often investigated in one- or two-dimensional numerical simulations. The sole 3-D numerical simulation gave attention only to the behavior at a single point on a fault. Moreover, with the sole exception based on a single-degree-freedom spring-slider model, the previous simulations including dilatancy and TP have not considered changes in hydraulic diffusivity. However, the hydraulic diffusivity, which strongly affects TP, can vary as a power of porosity. In this study, we apply a power law relationship between permeability and porosity. We consider both reversible and irreversible changes in porosity, assuming that the irreversible change is proportional to the slip rate and dilatancy coefficient ɛ. Our numerical simulations suggest that the effects of dilatancy can suppress slip and rupture velocity increased by TP. The results reveal that the amount of slip on the fault decreases with increasing ɛ or exponent of the power law, and the rupture velocity is predominantly suppressed by ɛ. This was observed regardless of whether the applied stresses were high or low. The deficit of the final slip in relation to ɛ can be smaller as the fault size is larger.

  2. Japanese clinical practice guidelines for congenital biliary dilatation.

    PubMed

    Ishibashi, Hiroki; Shimada, Mitsuo; Kamisawa, Terumi; Fujii, Hideki; Hamada, Yoshinori; Kubota, Masayuki; Urushihara, Naoto; Endo, Itaru; Nio, Masaki; Taguchi, Tomoaki; Ando, Hisami

    2017-01-01

    Until now, there have been no practical clinical guidelines for congenital biliary dilatation (CBD). In this review article, the Japanese Study Group on Congenital Biliary Dilatation (JSCBD) propose to establish clinical practice guidelines for CBD. Because the evidence-based literature is relatively small, we decided to create guidelines based on the consensus of experts, using the medical literature for reference. A total of 20 clinical questions (CQs) were considered by the members of the editorial committee responsible for the guidelines. The CQs included the distinct aspects of CBD: (1) Concepts and Pathology (three CQs); (2) Diagnosis (six CQs); (3) Pancreaticobiliary Complications (three CQs); Treatments and Prognosis (eight CQs). Each statements and comments for CQs were made by the guidelines committee members. CQs were finally approved after review by members of the editorial committee and the guidelines evaluation board of CBD. These guidelines were created to provide assistance in the clinical practice of CBD management; their contents focus on clinical utility, and they include general information on CBD to make this disease more widely recognized. © 2017 Japanese Society of Hepato-Biliary-Pancreatic Surgery.

  3. Viral Myocarditis and Dilated Cardiomyopathy: Etiology and Pathogenesis.

    PubMed

    Huber, Sally A

    2016-01-01

    Myocarditis is an inflammation of the myocardium which often follows microbial infections and is a significant cause of sudden unexpected death in the young (<40 years of age) and an underlying cause of dilated cardiomyopathy. Although histologically, the disease is usually associated with infiltration of the myocardium with either eosinophils or leukocytes, use of immunosuppression is controversial outside of giant cell myocarditis and has been found to be of limited value in lymphocytic myocarditis. The relatively limited response might reflect the need for host immunity to control persistent virus infection in the heart which may be the predominant cause of the chronic myocarditis and dilated cardiomyopathy. Treating the persistent virus infection with interferon-beta improved cardiac function in a clinical trial. However, classic immunosuppressive drugs, such as cyclosporine A and cyclophosphamide, are not effective against all types of immunity and experimental myocarditis models have shown that certain immunopathogenic forms of the disease are resistant to these immunosuppressive agents. Understanding the molecular mechanisms underlying the pathogenesis of this disease and the various infectious agents which can cause it will be essential for developing effective therapeutic agents.

  4. Dilated cerebral venous system observed in growth restricted fetuses.

    PubMed

    Baron, Joel; Mastrolia, Salvatore Andrea; Shelef, Ilan; Tirosh, Dan; Daniel-Spiegel, Etty; Hershkovitz, Reli

    2017-04-03

    The dilation of the fetal cerebral veins is a rare phenomena that may be associated to a bad obstetric outcome, and is usually connected to antenatal thrombosis of the posterior dural venous sinuses. There are several descriptions of cerebral vein distension on magnetic resonance imaging (MRI), but all of them are detected postnatally. We present herein two cases of fetal antenatal cerebral dilation of the venous system, without any association to any sign of vein thrombosis, and a systematic review of literature regarding pathogenesis, diagnosis and outcomes associated to the antenatal detection of this condition with the use of MRI. To identify potentially eligible studies, we searched PubMed, Scopus, Cochrane Library (all from inception to October 20(th), 2016) and applied no language restrictions. The electronic database search provided a total of 22843 results. After the exclusion of duplicates, manuscripts that resulted not relevant to the review based on title and abstract screening, and analysis of manuscripts eligible for full-text assessment, no papers were found related to the subject reported in the present manuscript.

  5. Superluminality in dilatationally invariant generalized Galileon theories

    NASA Astrophysics Data System (ADS)

    Kolevatov, R. S.

    2015-12-01

    We consider small perturbations about homogeneous backgrounds in dilatationally invariant Galileon models. The issues we address are stability (absence of ghosts and gradient instabilities) and superluminality. We show that in the Minkowski background, it is possible to construct the Lagrangian in such a way that any homogeneous Galileon background solution is stable and small perturbations about it are subluminal. On the other hand, in the case of Friedmann-Lemaitre-Robertson-Walker (FLRW) backgrounds, for any Lagrangian functions there exist homogeneous background solutions to the Galileon equation of motion and time dependence of the scale factor, such that the stability conditions are satisfied, but the Galileon perturbations propagate with superluminal speed.

  6. Black-white differences in mortality in idiopathic dilated cardiomyopathy: the Washington, DC, dilated cardiomyopathy study.

    PubMed Central

    Coughlin, S. S.; Gottdiener, J. S.; Baughman, K. L.; Wasserman, A.; Marx, E. S.; Tefft, M. C.; Gersh, B. J.

    1994-01-01

    Racial, socioeconomic, and clinical factors were examined as predictors of survival in idiopathic dilated cardiomyopathy using cases from five Washington, DC-area hospitals. One hundred three (80.5%) of the patients were black and 25 (19.5%) were white. The black patients were less likely to have private health insurance, less educated on average, and more likely to have a household income of $15,000 or less (P < or = .05). No racial differences were found in cardiac medication usage, with the exception of beta blockers and antiarrhythmics. The cumulative survival among black patients at 12 and 24 months was 71.5% and 63.6%, respectively, as compared with 92.0% and 86.3% among whites. The 12-month survival of black patients with ventricular arrhythmias or an ejection fraction of less than 25% was particularly poor. Age, ventricular arrhythmias, ejection fraction, and cigarette usage were significant predictors of survival in univariate analysis using the proportional hazards model. The univariate association with black race was of borderline significance (P < or = .07). In multivariate analysis, age and race were statistically significant independent predictors of survival. A strong association with black race was observed with an estimated relative risk of mortality of 5.41 (P < or = .02) after adjustment for age, ejection fraction, ventricular arrhythmias, and educational attainment. Poorer survival among blacks may be caused by a greater severity of disease at the time of diagnosis or by racial differences in cardiac care, comorbid conditions, or biologic factors affecting survival. PMID:7932836

  7. Development of Dilated Cardiomyopathy and Impaired Calcium Homeostasis with Cardiac-Specific Deletion of ESRRβ.

    PubMed

    Rowe, Glenn C; Asimaki, Angeliki; Graham, Evan L; Martin, Kimberly D; Margulies, Kenneth B; Das, Saumya; Saffitz, Jeffrey E; Arany, Zoltan

    2017-01-27

    Mechanisms underlying the development of Idiopathic Dilated Cardiomyopathy (DCM) remain poorly understood. Using transcription factor expression profiling, we identified estrogen-related receptor beta (ESRRβ), a member of the nuclear receptor family of transcription factors, as highly expressed in murine hearts and other highly oxidative striated muscle beds. Mice bearing cardiac-specific deletion of ESRRβ (MHC-ERRB KO) develop dilated cardiomyopathy and sudden death at approximately 10 months of age. Isolated adult cardiomyocytes from the MHC-ERRB KO mice showed an increase in calcium sensitivity and impaired cardiomyocyte contractility, which preceded echocardiographic cardiac remodeling and dysfunction by several months. Histological analyses of myocardial biopsies from patients with various cardiomyopathies revealed that ESRRβ protein is absent from the nucleus of cardiomyocytes from patients with DCM, but not other forms of cardiomyopathy (ischemic, hypertrophic and arrhythmogenic right ventricular cardiomyopathy). Taken together these observations suggest that ESRRβ is a critical component in the onset of dilated cardiomyopathy by affecting contractility and calcium balance.

  8. On the mechanism of the coronary dilator effect of serotonin in the dog.

    PubMed

    Mena, M A; Vidrio, H

    1976-03-01

    In experiments designed to determine the nature of the coronary dilator effect of serotonin the influence of intracoronary administration of the amine on coronary perfusion pressure, heart rate and ventricular contractile force was assessed in anesthetized open-chest dogs in which the left coronary artery was perfused with blood at a constant rate. Serotonin elicited dose-related decreases in coronary perfusion pressure and increases in contractile force, and lowered heart rate slightly. The dilator response was antagonized by methysergide, slightly potentiated by practolol and unaffected by reserpine. The inotropic effect was partially antagonized by methysergide and completely blocked by practolol and reserpine. It is concluded that serotonin induces coronary dilatation by direct stimulation of specific receptors that this effect is independent of the cardiac stimulation produced by the amine, and the latter response is mediated through beta1-adrenoceptors activated by released norepinephrine.

  9. Endoscopic dilation with Savary-Gilliard bougies of stomal strictures after laparosocopic gastric bypass in morbidly obese patients.

    PubMed

    Fernández-Esparrach, Glòria; Bordas, Josep M; Llach, Josep; Lacy, Antonio; Delgado, Salva; Vidal, Josep; Cárdenas, Andrés; Pellisé, Maria; Ginès, Angels; Sendino, Oriol; Zabalza, Michel; Castells, Antoni

    2008-02-01

    Anastomotic strictures after bariatric surgery are a frequent complication that requires endoscopic management, but the optimal technique for dilation remains to be determined. The aim of this study was to evaluate the safety and efficacy of dilation with Savary-Gilliard bougies (SGB) in morbidly obese patients treated with laparoscopic Roux-en-Y gastric bypass (RYGBP). Retrospective review of prospectively collected data from a series of 474 consecutive patients with laparoscopic bariatric surgery. Four-hundred twenty four of these patients (90%) underwent a laparoscopic RYGBP. A total of 24 patients were referred for anastomotic stricture dilation with SGB from January 1998 to December 2006. A total of 24/424 patients (6%) developed a stricture that was successfully dilated with SGB. Patients were 17 females (71%) and seven males (29%) with a mean age of 41 +/- 11 years (range 24-63) and a mean BMI of 48 +/- 6 (range 40-69). The time between RYGBP and the appearance of stricture-related symptoms ranged from 29 to 154 days (mean, 69 days). The mean number of dilations was 1.6 +/- 0.6. The majority of patients required one (n = 11; 46%) or two (n = 12; 50%) dilations and only one patient required three dilations. During the initial dilation, a final diameter of 11 +/- 1.7 mm (range 7-12.8 mm) was achieved. In all cases, there was complete resolution of symptoms. There were no complications. Dilation with SGB is an effective, safe, and durable method for managing anastomotic strictures after laparoscopic RYGBP.

  10. Assessment of flow-mediated vasodilatation (FMD) of the brachial artery: effects of technical aspects of the FMD measurement on the FMD response.

    PubMed

    Bots, Michiel L; Westerink, Jan; Rabelink, Ton J; de Koning, Eelco J P

    2005-02-01

    The ability to assess endothelial function non-invasively with B-mode ultrasound has lead to its widespread application in a variety of studies. However, the absolute values obtained using this approach vary considerably across studies. We studied whether technical aspects of the methodology can explain the wide variety in absolute values across studies. A literature search was performed to identify published reports on flow-mediated vasodilatation (FMD) of the brachial artery published between 1992 and 2001. Information on type of equipment (wall track/B-mode), location of the measurement (antecubital fossa/upper arm), occlusion site (lower/upper arm), occlusion duration (min), and occlusion pressure was extracted. Patient characteristics were also extracted. For the healthy populations, mean FMD varied from 0.20 to 19.2%; for the coronary heart disease (CHD) patients FMD varied from -1.3 to 14%; for subjects with diabetes mellitus FMD varied from 0.75 to 12%. Compared with occlusion at the upper arm, lower arm occlusion was related to decreased FMD (mean difference in FMD -2.47%; 95% CI 0.55-4.39). An occlusion duration of > or =4.5 min was related to an increased FMD compared with an occlusion time of < or =4 min (mean difference 1.30%; 95% CI 0.35-2.46). These findings were adjusted for other technical aspects of the methodology and for differences in risk factors between populations. Mean FMD differs widely between studies. There is a great overlap between populations (healthy, CHD, diabetics). Our findings suggest that the technical aspects of the measurements, the location, and the duration of the occlusion may explain some of these differences, whereas type of equipment, location of the measurement, and occlusion pressure do not.

  11. Measurement of gravitational time dilation: An undergraduate research project

    NASA Astrophysics Data System (ADS)

    Burns, M. Shane; Leveille, Michael D.; Dominguez, Armand R.; Gebhard, Brian B.; Huestis, Samuel E.; Steele, Jeffrey; Patterson, Brian; Sell, Jerry F.; Serna, Mario; Gearba, M. Alina; Olesen, Robert; O'Shea, Patrick; Schiller, Jonathan

    2017-10-01

    General relativity predicts that clocks run more slowly near massive objects. The effect is small—a clock at sea level lags behind one 1000 m above sea level by only 9.4 ns/day. Here, we demonstrate that a measurement of this effect can be done by undergraduate students. Our paper describes an experiment conducted by undergraduate researchers at Colorado College and the United States Air Force Academy to measure gravitational time dilation. The measurement was done by comparing the signals generated by a GPS frequency standard (sea-level time) to a Cs-beam frequency standard at seven different altitudes above sea level. We found that our measurements are consistent with the predictions of general relativity.

  12. Posttransplant Complex Inferior Venacava Balloon Dilatation After Hepatic Vein Stenting

    SciTech Connect

    Kohli, Vikas; Wadhawan, Manav; Gupta, Subhash; Roy, Vipul

    2010-02-15

    Orthotopic and living related liver transplantation is an established mode of treatment of end-stage liver disease. One of the major causes of postoperative complications is vascular anastomotic stenosis. One such set of such complications relates to hepatic vein, inferior vena cava (IVC), or portal vein stenosis, with a reported incidence of 1-3%. The incidence of vascular complications is reported to be higher in living donor versus cadaveric liver transplants. We encountered a patient with hepatic venous outflow tract obstruction, where the hepatic vein had been previously stented, but the patient continued to have symptoms due to additional IVC obstruction. The patient required double-balloon dilatation of the IVC simultaneously from the internal jugular vein and IVC.

  13. [Preserving autologous heart operation for dilated cardiomyopathy].

    PubMed

    Hoshino, Joji; Fukada, Yasuhisa; Hirota, Masanori; Kondo, Taichi; Isomura, Tadashi

    2013-01-01

    We report non transplant surgical procedure (preserving autologous heart operation) for the patients with dilated cardiomyopathy( DCM), clinical outcomes, and the factor of predict prognosis. Since May 2000, 258 patients received surgical procedure for 11 years. We performed mitral surgery (plasty or replacement) for the patients with more than mild mitral regurgitation (MR). We performed papirally muscule plication since 2005, and we performed 2nd chordal cutting since 2008, for the patients with MR due to mitral tethering. The surgical left ventricular reconstruction( SVR) was performed for the patients with dilated left ventricular. We use spackle tracking echocardiography to decide the type of SVR since 2008. Hospital death was 18.2%, and late cardiac death was 27.5%.Almost the cause of death was congestive heart failure and ventricular arrhythmia. Five years survival was 58%, 10 years survival was 39%. Preoperative condition, emergent operation, inotropic support, intra aortic balloon pumping(IABP),affect the prognosis. But left ventricular size did not affect it. Surgical treatment for the patient with DCM should be performed with stable preoperative condition.

  14. Pupil Dilation: A Fingerprint of Temporal Selection During the “Attentional Blink”

    PubMed Central

    Zylberberg, Ariel; Oliva, Manuel; Sigman, Mariano

    2012-01-01

    Pupil dilation indexes cognitive events of behavioral relevance, like the storage of information to memory and the deployment of attention. Yet, given the slow temporal response of the pupil dilation, it is not known from previous studies whether the pupil can index cognitive events in the short time scale of ∼100 ms. Here we measured the size of the pupil in the Attentional Blink (AB) experiment, a classic demonstration of attentional limitations in processing rapidly presented stimuli. In the AB, two targets embedded in a sequence have to be reported and the second stimulus is often missed if presented between 200 and 500 ms after the first. We show that pupil dilation can be used as a marker of cognitive processing in AB, revealing both the timing and amount of cognitive processing. Specifically, we found that in the time range where the AB is known to occur: (i) the pupil dilation was delayed, mimicking the pattern of response times in the Psychological Refractory Period (PRP) paradigm, (ii) the amplitude of the pupil was reduced relative to that of larger lags, even for correctly identified targets, and (iii) the amplitude of the pupil was smaller for missed than for correctly reported targets. These results support two-stage theories of the Attentional Blink where a second processing stage is delayed inside the interference regime, and indicate that the pupil dilation can be used as a marker of cognitive processing in the time scale of ∼100 ms. Furthermore, given the known relation between the pupil dilation and the activity of the locus coeruleus, our results also support theories that link the serial stage to the action of a specific neuromodulator, norepinephrine. PMID:22973248

  15. Dilatation balloons: polymer selection, balloon design and assembly.

    PubMed

    Crittenden, J F

    1987-01-01

    The current status of coronary dilating instruments is presented from the designer's perspective. Catheter shaft design is considered by important features, common catheter materials and types of catheter construction. Among the seven companies manufacturing balloon dilating instruments, only three types of catheter and four materials are offered. Balloon design is presented by important features and by materials selected. Performance comparisons are made between the three materials used to fabricate dilating balloons: PVC, PE and PET.

  16. Duodenal adenocarcinoma presenting as a mass with aneurismal dilatation.

    PubMed

    Mama, Nadia; Ben Slama, Aïda; Arifa, Nadia; Kadri, Khaled; Sriha, Badreddine; Ksiaa, Mehdi; Jemni, Hela; Tlili-Graiess, Kalthoum

    2014-01-01

    Duodenal adenocarcinoma is frequent. Aneurysmal dilatation of the small bowel is reported to be a lymphoma characteristic imaging finding. A 57-year-old male was found to have a duodenal adenocarcinoma with aneurismal dilatation on imaging which is an exceptional feature. On laparotomy, the wall thickening of the dilated duodenum extended to the first jejunal loop, with multiple mesenteric lymph nodes and ascites. Segmental palliative resection with gastro-entero-anastomosis was done. Histopathology revealed a moderately differentiated adenocarcinoma with neuro-endocrine differentiation foci. Wide areas of necrosis and vascular emboli were responsible for the radiological feature of the dilated duodenum with wall thickening.

  17. Vaginal dilator therapy for women receiving pelvic radiotherapy.

    PubMed

    Miles, Tracie; Johnson, Nick

    2014-09-08

    Vaginal dilation therapy is advocated after pelvic radiotherapy to prevent stenosis (abnormal narrowing of the vagina), but can be uncomfortable and psychologically distressing. To assess the benefits and harms of different types of vaginal dilation methods offered to women treated by pelvic radiotherapy for cancer. Searches included the Cochrane Central Register of Controlled Trials (CENTRAL 2013, Issue 5), MEDLINE (1950 to June week 2, 2013), EMBASE (1980 to 2013 week 24) and CINAHL (1982 to 2013). Comparative data of any type, which evaluated dilation or penetration of the vagina after pelvic radiotherapy treatment for cancer. Two review authors independently assessed whether potentially relevant studies met the inclusion criteria. We found no trials and therefore analysed no data. We identified no studies for inclusion in the original review or for this update. However, we felt that some studies that were excluded warranted discussion. These included one randomised trial (RCT), which showed no improvement in sexual scores associated with encouraging women to practise dilation therapy; a recent small RCT that did not show any advantage to dilation over vibration therapy during radiotherapy; two non-randomised comparative studies; and five correlation studies. One of these showed that objective measurements of vaginal elasticity and length were not linked to dilation during radiotherapy, but the study lacked power. One study showed that women who dilated tolerated a larger dilator, but the risk of objectivity and bias with historical controls was high. Another study showed that the vaginal measurements increased in length by a mean of 3 cm after dilation was introduced 6 to 10 weeks after radiotherapy, but there was no control group; another case series showed the opposite. Three recent studies showed less stenosis associated with prophylactic dilation after radiotherapy. One small case series suggested that dilation years after radiotherapy might restore the

  18. Fluoroscopically Guided Balloon Dilation for Postintubation Tracheal Stenosis

    SciTech Connect

    Lee, Woong Hee; Kim, Jin Hyoung Park, Jung-Hun

    2013-10-15

    Purpose: Little was known about the safety and long-term efficacy of fluoroscopically guided balloon dilation for postintubation tracheal stenosis. The purpose of this study was to evaluate the safety and long-term efficacy of fluoroscopically guided balloon dilation in patients with postintubation tracheal stenosis. Methods: From February 2000 to November 2010, 14 patients underwent fluoroscopically guided balloon dilation for postintubation tracheal stenosis. Technical success, clinical success, and complications were evaluated. Patients were followed up for recurrent symptoms. Results: In all patients, fluoroscopically guided balloon dilation was technically and clinically successful with no major complications. Following the initial procedure, six patients (43 %) remained asymptomatic during a follow-up period. Obstructive symptoms recurred in eight patients (57 %) within 6 months (mean, 1.7 months), who were treated with repeat balloon dilation (n = 4) and other therapies. Of the four patients who underwent repeat balloon dilation, three became asymptomatic. One patient became asymptomatic after a third balloon dilation. On long-term (mean, 74 months) follow-up, 71 % of patients experienced relief of symptoms following fluoroscopically guided balloon dilation. Conclusions: Fluoroscopically guided balloon dilation may be safe, is easy to perform, and resulted in effective treatment in patients with postintubation tracheal stenosis.

  19. Physical dilatation of the nostrils lowers the thermal strain of exercising humans.

    PubMed

    White, M D; Cabanac, M

    1995-01-01

    Increased nasal air flow during exercise was examined as a possible heat loss avenue contributing to selective brain cooling in hyperthermic humans. On 2 separate days, eight subjects [mean (SE) age, 26.4 (1.2) years] exercised on a cycle ergometer in a warm room [28 (0.2) degrees C; 28 (5)% relative humidity] to induce a moderate level of hyperthermia. In one session the nostrils were physically dilatated [average dilatation 1.55 (0.17) times] and in the other they were not (control). Both sessions started with a 5-min resting period; then subjects pedaled at 60 W for 5 min, 100 W for 15 min, and 150 W for 20 min. During dilatation both tympanic temperature (Tty) and forehead skin blood flow, estimated by laser doppler velocimetry, were significantly lower than during the control exercise of 150 W. Rates of increase of Tty during the 100-W exercise were the same in both conditions; however, during the 150-W exercise with dilatated nostrils Tty increased at a rate significantly lower than during control [1.1 (0.3) degrees C.h-1 vs 1.5 (0.4) degrees C.h-1]. The change in the rate of increase of Tty between conditions was significantly correlated to the degree of nostril dilatation (r = -0.77, P = 0.02), suggesting that the lower Tty observed was due to nostril dilatation. Facial skin temperature was not significantly different between sessions. The results suggest that the nasal cavity may act as a heat exchanger in selective brain cooling of exercising humans.

  20. Common bile duct stones associated with pancreatobiliary reflux and disproportionate bile duct dilatation.

    PubMed

    Huh, Cheal Wung; Kim, Hee Wook; Yi, Seung Woo; Lee, Dong Ki; Lee, Se Joon

    2017-08-01

    Occult pancreatobiliary reflux (PBR) in patients with a normal pancreatobiliary junction has been studied by various methods, but the exact etiology, mechanisms, and implications of this reflux have not yet been clarified. The aim of this study was to investigate the degree of PBR and patterns of biliary ductal dilatation in patients with acute calculous cholangitis by endoscopic retrograde cholangiopancreatography (ERCP).We retrospectively evaluated the degree of PBR and pattern of bile duct dilatation in patients with acute calculous cholangitis due to distal CBD (common bile duct) stones (Group A) as compared with patients with malignant CBD obstruction due to distal CBD cancer (Group B). All related data were prospectively collected. Bile juice was aspirated at the proximal CBD for measurement of biliary amylase and lipase before the injection of contrast dye. The diameters of the CBD and the peripheral intrahepatic duct (IHD) were calculated after contrast dye injection. Patients with pancreatobiliary maljunction and/or gallstone pancreatitis were excluded from the study.ERCP was performed on 33 patients with calculous cholangitis (Group A) and 12 patients with malignant CBD obstruction (Group B). Mean levels of bile amylase and lipase were significantly higher (P < .05) in group A (1387 and 6737 U/l, respectively) versus those in group B (32 and 138 U/l, respectively). Thirty patients in group A (90.9%) showed disproportionate dilatation (i.e., CBD was and IHD was not dilated), whereas only 4 patients in group B (33%) showed disproportionate dilatation.The results of this study suggest that patients with calculous cholangitis exhibit PBR that is associated with disproportionate bile duct dilatation.

  1. Dilatation and Curettage Effect on the Endometrial Thickness

    PubMed Central

    Davar, Robab; Dehghani Firouzabadi, Razieh; Chaman Ara, Kefayat

    2013-01-01

    Background Endometrial receptivity is required for successful implantation and pregnancy. Despite the remaining controversy, many studies have shown that ultrasonographic endometrial thickness can be considered as an indicator of endometrial receptivity. Objective The study objective was to investigate the effect of dilatation and curettage on the endometrial thickness. Materials and Methods Enrolled in the study were 444 patients visited in Obstetrics & Gynecology clinic of Shahid Sadoughi hospital between Jan. 2011 to Sep. 2012. Only patients whose menstrual cycle was regular were included in study. Patients with myoma, adenomyosis, endometrial polyps or other uterine anomaly, those who smoked, whose BMI was greater than 30 and who were taking medications that could affect endometrial thickness were excluded. Endometrial thickness was measured one day before evolution (n = 444) and 5-7 days after it (n = 444) using transvaginal ultrasonography. The endometrial thicknesses were correlated to the patients’ history of dilatation and curettage. Data analysis was done through SPSS software version 16 and using descriptive statistics, independent T-test and Anova. Results Endometrial thickness in patients who had 0, 1, 2, 3 and 4 D&C were 10.00 ± 0.58, 9.83 ± 0.47, 8.90 ± 0.92, 7.42 ± 0.18 and 7.40 ± 0.07, respectively one day before ovulation (spearman’s correlation coefficient = -0.33) and 10.62 ± 0.68, 9.64 ± 0.49, 8.48 ± 0.96, 6.32 ± 0.15 and 6.90 ± 0.04, respectively, 5-7 days after ovulation (spearman’s correlation coefficient = -0.66) estradiol and progesterone levels, measured in the day of 2nd ultrasonography had not statistic relation with endometrial thickness (P = 0.27 and 0.31). The relation of endometrial thickness and age was not significant (P = 0.54 and 0.06). Conclusions Dilatation and curettage has a significant effect on the endometrial thinning. PMID:24083012

  2. Gap-flow Mediated Transport of Pollution to a Remote Coastal Site: Effects upon Aerosol Composition

    NASA Astrophysics Data System (ADS)

    Cornwell, G.; Martin, A.; Petters, M.; Prather, K. A.; Taylor, H.; Rothfuss, N.; DeMott, P. J.; Kreidenweis, S. M.

    2015-12-01

    During the CalWater 2015 field campaign, observations of aerosol size, concentration, chemical composition, and cloud activity were made at Bodega Bay, CA on the remote California coast. Strong anthropogenic influence on air quality, aerosol physicochemical properties and cloud activity was observed at Bodega Bay during periods of special meteorological conditions, known as Petaluma Gap Flow, in which air from California's interior is transported to the coast. This study utilizes single particle mass spectrometry, along with aerosol physical and chemical measurements and meteorological measurements to show that the dramatic change in aerosol properties is strongly related to regional meteorology and anthropogenically-influenced chemical processes in California's Central Valley. The change in airmass properties from those typical of a remote marine environment to properties of a continental regime has impacts on atmospheric radiative balance and cloud formation that must be accounted for in regional climate simulation.

  3. Increasing TRPV4 expression restores flow-induced dilation impaired in mesenteric arteries with aging.

    PubMed

    Du, Juan; Wang, Xia; Li, Jie; Guo, Jizheng; Liu, Limei; Yan, Dejun; Yang, Yunyun; Li, Zhongwen; Zhu, Jinhang; Shen, Bing

    2016-03-07

    The flow-stimulated intracellular Ca(2+) concentration ([Ca(2+)]i) rise in endothelial cells is an important early event leading to flow-induced blood vessel dilation. Transient receptor potential vanilloid subtype 4 (TRPV4), a Ca(2+)-permeable cation channel, facilitates the flow-stimulated [Ca(2+)]i rise. To determine whether TRPV4 is involved in age-related flow-induced blood vessel dilation impairment, we measured blood vessel diameter and nitric oxide (NO) levels and performed Ca(2+) imaging, immunoblotting, and immunostaining assays in rats. We found that the flow-induced and TRPV4 activator 4α-PDD-induced dilation of mesenteric arteries from aged rats were significantly decreased compared with those from young rats. The flow- or 4α-PDD-induced [Ca(2+)]i rise was also markedly reduced in primary cultured mesenteric artery endothelial cells (MAECs) from aged rats. Immunoblotting and immunostaining results showed an age-related decrease of TRPV4 expression levels in MAECs. Additionally, the 4α-PDD-induced NO production was significantly reduced in aged MAECs. Compared with lentiviral GFP-treated aged rats, lentiviral vector delivery of TRPV4 increased TRPV4 expression level in aged MAECs and restored the flow- and 4α-PDD-induced vessel dilation in aged mesenteric arteries. We concluded that impaired TRPV4-mediated Ca(2+) signaling causes endothelial dysfunction and that TRPV4 is a potential target for clinical treatment of age-related vascular system diseases.

  4. Vaginal dilator therapy for women receiving pelvic radiotherapy

    PubMed Central

    Miles, Tracie; Johnson, Nick

    2014-01-01

    Background Many vaginal dilator therapy guidelines advocate routine vaginal dilation during and after pelvic radiotherapy to prevent stenosis (abnormal narrowing of the vagina). The UK Gynaecological Oncology Nurse Forum recommend dilation “three times weekly for an indefinite time period”. The UK patient charity Cancer Backup advises using vaginal dilators from two to eight weeks after the end of radiotherapy treatment. Australian guidelines recommend dilation after brachytherapy “as soon as is comfortably possible” and “certainly within four weeks and to continue for three years or indefinitely if possible”. However, dilation is intrusive, uses health resources and can be psychologically distressing. It has also caused rare but very serious damage to the rectum. Objectives To review the benefits and harms of vaginal dilation therapy associated with pelvic radiotherapy for cancer. Search methods Searches included the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2008, Issue 4), MEDLINE (1950 to 2008), EMBASE (1980 to 2008) and CINAHL (1982 to 2008). Selection criteria Any comparative randomised controlled trials (RCT) or data of any type which compared dilation or penetration of the vagina after pelvic radiotherapy treatment for cancer. Data collection and analysis The review authors independently abstracted data and assessed risk of bias. We analysed the mean difference in sexual function scores and the risk ratio for non-compliance at six weeks and three months in single trial analyses. No trials met the inclusion criteria. Main results Dilation during or immediately after radiotherapy can, in rare cases, cause damage and there is no persuasive evidence from any study to demonstrate that it prevents stenosis. Data from one RCT showed no improvement in sexual scores in women who were encouraged to practice dilation. Two case series and one comparative study using historical controls suggest that dilation might be

  5. Noninvasive Assessment of Pulse-Wave Velocity and Flow-Mediated Vasodilation in Anesthetized Göttingen Minipigs

    PubMed Central

    Ludvigsen, Trine P; Wiinberg, Niels; Jensen, Christina J; Callesen, Annemette T; Andersen, Regitze W; Jørgensen, Anne Sofie H; Christoffersen, Berit Ø; Pedersen, Henrik D; Moesgaard, Sophia G; Olsen, Lisbeth H

    2014-01-01

    Few methods for noninvasive assessment of arterial stiffness and endothelial dysfunction in porcine models are available. The aim of this study was to evaluate methods for assessment of arterial stiffness and endothelial dysfunction in anesthetized Göttingen minipigs. Pulse-wave velocity (PWV) was assessed in male Göttingen minipigs (n = 8; age approximately 60 wk) by using applanation tonometry of the carotid and femoral arteries. In addition, flow-mediated vasodilation (FMD) was assessed by using vascular ultrasonography of the brachial artery to evaluate endothelial dysfunction. To evaluate the reproducibility of the methods, minipigs were anesthetized by intravenous infusion of ketamine and midazolam and examined every other day for a total of 3 trials. Neither examination day nor systolic, diastolic, or mean arterial blood pressure statistically influenced PWV or FMD. The median interexamination coefficient of variation was 17% for PWV and 59% for FMD. Measured values of PWV corresponded largely to those in clinically healthy humans, but FMD values were lower than expected for lean, young animals. Although the ketamine–midazolam anesthesia we used has been associated with minor hemodynamic effects in vivo, in vitro studies suggest that both drugs are vasodilatory. Therefore anesthesia might have influenced the endothelial response, contributing to the modest FMD response and the concurrent high coefficients of variation that we noted. We conclude that PWV—but not FMD—showed acceptable interexamination variation for its potential application in porcine models. PMID:25527028

  6. Dilatancy in the flow and fracture of stretched colloidal suspensions.

    PubMed

    Smith, M I; Besseling, R; Cates, M E; Bertola, V

    2010-11-16

    Concentrated particulate suspensions, commonplace in the pharmaceutical, cosmetic and food industries, display intriguing rheology. In particular, the dramatic increase in viscosity with strain rate (shear thickening and jamming), which is often observed at high-volume fractions, is of practical and fundamental importance. Yet, manufacture of these products and their subsequent dispensing often involves flow geometries substantially different from that of simple shear flow experiments. In this study, we show that the elongation and breakage of a filament of a colloidal fluid under tensile loading is closely related to the jamming transition seen in its shear rheology. However, the modified flow geometry reveals important additional effects. Using a model system with nearly hard-core interactions, we provide evidence of surprisingly strong viscoelasticity in such a colloidal fluid under tension. With high-speed photography, we also directly observe dilatancy and granulation effects, which lead to fracture above a critical elongation rate.

  7. Time dilation in relativistic two-particle interactions

    SciTech Connect

    Shields, B. T.; Morris, M. C.; Ware, M. R.; Su, Q.; Grobe, R.; Stefanovich, E. V.

    2010-11-15

    We study the orbits of two interacting particles described by a fully relativistic classical mechanical Hamiltonian. We use two sets of initial conditions. In the first set (dynamics 1) the system's center of mass is at rest. In the second set (dynamics 2) the center of mass evolves with velocity V. If dynamics 1 is observed from a reference frame moving with velocity -V, the principle of relativity requires that all observables must be identical to those of dynamics 2 seen from the laboratory frame. Our numerical simulations demonstrate that kinematic Lorentz space-time transformations fail to transform particle observables between the two frames. This is explained as a result of the inevitable interaction dependence of the boost generator in the instant form of relativistic dynamics. Despite general inaccuracies of the Lorentz formulas, the orbital periods are correctly predicted by the Einstein's time dilation factor for all interaction strengths.

  8. [Cardiomyopathies. I: classification of cardiomyopathies--dilated cardiomyopathy].

    PubMed

    Schultheiss, H P; Noutsias, M; Kühl, U; Lassner, D; Gross, U; Poller, W; Pauschinger, M

    2005-11-01

    Cardiomyopathies are common causes of heart failure and sudden cardiac death. According to the WHO classification, "specific" cardiomyopathies are differentiated from "idiopathic" cardiomyopathies. Thus, this classification is primarily based on pathophysiological characteristics. The diagnostic spectrum in cardiomyopathies comprises the entire spectrum of non-invasive and invasive cardiological examination techniques. The exact verification of certain cardiomyopathies necessitates additionally investigations. For example, immunohistological and molecular biological investigations of endomyocardial biopsies may confirm inflammatory cardiomyopathy, which is often induced by viruses. Several studies have shown that specific immunomodulatory treatment options can halt the progressive course of the disease. Several gene mutations have been identified in genetic/familial dilated cardiomyopathy. First-degree relatives should be screened for early stages. Primary prevention of sudden cardiac death shows increasing superiority of the implantable defibrillator compared with pharmacological approaches (i.e. amiodarone).

  9. Dilated cardiomyopathy in an American cocker spaniel with taurine deficiency.

    PubMed

    Gavaghan, B J; Kittleson, M D

    1997-12-01

    An American Cocker Spaniel with low plasma taurine concentration (< 2 nmol/mL) was presented with dyspnoea associated with pulmonary oedema and a left ventricular shortening fraction of 9%. Emergency therapy with furosemide, dobutamine, nitroglycerine and oxygen supplementation led to a good response. Chronic therapy was started with enalapril, furosemide, digoxin and taurine. Improvement in all echocardiographic indices were noted over a 22 week follow-up, most notably an increase in left ventricular shortening fraction to 20%, a decrease of E-point septal separation from 14 mm to 7 mm and marked left ventricular remodelling. This degree of improvement in myocardial function may represent a direct link between dilated cardiomyopathy in the American Cocker Spaniel and plasma taurine deficiency. Alternatively, this response may reflect a breed-related cardiomyopathy with a natural history and therapeutic response not commonly seen in the more common large breed cardiomyopathy presentations.

  10. Developmental dilatation of Virchow-Robin spaces: a genetic disorder?

    PubMed

    Bruna, Anne-Laure; Martins, Ilda; Husson, Beatrice; Landrieu, Pierre

    2009-10-01

    In childhood, widening of Virchow-Robin spaces is rarely secondary to specific progressive disorders, but more often appears in poorly characterized developmental conditions. From data collected in a neuropediatric department, we examined whether clinical data associated with "constitutional widening of Virchow-Robin spaces" allowed delineation of recognizable entities. Signs in 10 patients, mostly boys, suggested nonspecific cerebral dysfunctions, e.g., developmental delay, nonspecific epilepsy, headaches, or benign macrocephaly. Spaces were sometimes round, subsequently mimicking microcystic malacic lesions. In two patients, abnormal magnetic resonance imaging signals were evident in white matter contiguous to widened perivascular spaces, suggesting a broader disorder of fluid exchanges. Four cases occurred in two sibships. In two families, other patients exhibited early developmental difficulties. Long-term clinical and magnetic resonance imaging surveillance will clarify which cases of primary Virchow-Robin space dilatation imply a benign prognosis. Performance of magnetic resonance imaging on any relative exhibiting minor neuropsychologic handicaps would permit estimations of real genetic incidence.

  11. Balloon catheter dilatation and thrombectomy for acute aortoiliac occlusion

    PubMed Central

    Archie, Joseph P.

    1981-01-01

    A case of acute distal aortic thrombosis in an elderly high-risk patient was successfully managed with intraoperative thrombectomy and balloon catheter dilatation of the common iliac arteries. Balloon catheter dilatation may be indicated prior to bypass grafting in high-risk patients with acute aortoiliac thrombosis. PMID:15216181

  12. Significance of Main Pulmonary Artery Dilation on Imaging Studies

    PubMed Central

    Raymond, Timothy E.; Khabbaza, Joseph E.; Yadav, Ruchi

    2014-01-01

    Proper and early identification of patients who harbor serious occult illness is the first step in developing a disease-management strategy. Identification of illnesses through the use of noninvasive techniques provides assurance of patient safety and is ideal. PA dilation is easily measured noninvasively and is due to a variety of conditions, including pulmonary hypertension (PH). The clinician should be able to thoroughly assess the significance of PA dilation in each individual patient. This involves knowledge of the ability of PA dilation to accurately predict PH, understand the wide differential diagnosis of causes of PA dilation, and reverse its life-threatening complications. We found that although PA dilation is suggestive of PH, data remain inconclusive regarding its ability to accurately predict PH. At this point, data are insufficient to place PA dilation into a PH risk-score equation. Here we review the causes and complications of PA dilation, define normal and abnormal PA measurements, and summarize the data linking its association to PH, while suggesting an algorithm designed to assist clinicians in patient work-up after recognizing PA dilation. PMID:25406836

  13. Endosonography for Pancreatic Duct Dilatation without Definite Pathology on Ultrasonography.

    PubMed

    Chen, Chien-Hua; Yang, Chi-Chieh; Yeh, Yung-Hsiang

    2014-05-01

    Main pancreatic duct dilatation raises concerns about the possibility of pancreatobiliary malignancy. We evaluated the etiologic yield of endosonography (EUS) for main pancreatic duct dilatation without definite pathology on Ultrasonography (US). A retrospective review was conducted in 54 consecutive patients referred for EUS. No pathological finding (37.0%, 20/54), followed by periampullary cancer (35.2%, 19/54), was the most common finding. Elevated alkaline phosphatase (ALK-P) and marked common bile duct (CBD) dilatation (≥ 12 mm) were the predictors of malignancy (p < 0.05). Among the 37 subjects with available ALK-P and CBD diameter, the probability of malignancy was 84.6% (11/13) for both elevated ALK-P and marked CBD dilatation, 16.7% (1/6) for isolated elevated ALK-P, 18.2% (2/11) for isolated marked CBD dilatation, and none (0/7) was for subjects with neither elevated ALK-P nor marked CBD dilatation, respectively. The overall accuracy of EUS for periampullary carcinomas was 94.7% (18/19) and for choledocholithiasis was 100% (7/7), respectively. EUS had a 100.0% (20/20) sensitivity and a 97.1% (33/34) specificity in the diagnosis of no pathological obstruction. EUS is accurate for main pancreatic duct dilatation without definite pathology on US, and the presence of concomitant elevated ALK-P and CBD dilatation highly suggests malignancy.

  14. Dilated Canine Hearts: A Specimen for Teaching Cardiac Anatomy

    ERIC Educational Resources Information Center

    Cope, Lee Anne

    2008-01-01

    Dilated canine hearts were used to teach undergraduate students internal and external cardiac anatomy. The specimens were dilated using hydrostatic pressure and then fixed using 5% formalin. These specimens provided the students with an alternative to prepackaged embalmed hearts and anatomical models for studying the external and internal cardiac…

  15. Dilated Canine Hearts: A Specimen for Teaching Cardiac Anatomy

    ERIC Educational Resources Information Center

    Cope, Lee Anne

    2008-01-01

    Dilated canine hearts were used to teach undergraduate students internal and external cardiac anatomy. The specimens were dilated using hydrostatic pressure and then fixed using 5% formalin. These specimens provided the students with an alternative to prepackaged embalmed hearts and anatomical models for studying the external and internal cardiac…

  16. Cardiac dilatation and pump dysfunction without intrinsic myocardial systolic failure following chronic beta-adrenoreceptor activation.

    PubMed

    Osadchii, Oleg E; Norton, Gavin R; McKechnie, Richard; Deftereos, Dawn; Woodiwiss, Angela J

    2007-04-01

    There is no direct evidence to indicate that pump dysfunction in a dilated chamber reflects the impact of chamber dilatation rather than the degree of intrinsic systolic failure resulting from myocardial damage. In the present study, we explored the relative roles of intrinsic myocardial systolic dysfunction and chamber dilatation as mediators of left ventricular (LV) pump dysfunction. Administration of isoproterenol, a beta-adrenoreceptor agonist, for 3 mo to rats (0.1 mg.kg(-1).day(-1)) resulted in LV pump dysfunction as evidenced by a reduced LV endocardial fractional shortening (echocardiography) and a decrease in the slope of the LV systolic pressure-volume relation (isolated heart preparations). Although chronic beta-adrenoreceptor activation induced cardiomyocyte damage (deoxynucleotidyl transferase-mediated dUTP nick-end labeling) as well as beta(1)- and beta(2)-adrenoreceptor inotropic downregulation (attenuated contractile responses to dobutamine and salbutamol), these changes failed to translate into alterations in intrinsic myocardial contractility. Indeed, LV midwall fractional shortening (echocardiography) and the slope of the LV systolic stress-strain relation (isolated heart preparations) were unchanged. A normal intrinsic myocardial systolic function, despite the presence of cardiomyocyte damage and beta-adrenoreceptor inotropic downregulation, was ascribed to marked increases in myocardial norepinephrine release, to upregulation of alpha-adrenoreceptor-mediated contractile effects as determined by phenylephrine responsiveness, and to compensatory LV hypertrophy. LV pump failure was attributed to LV dilatation, as evidenced by increased LV internal dimensions (echocardiography), and a right shift and increased volume intercept of the LV diastolic pressure-volume relation. In conclusion, chronic sympathetic stimulation, despite reducing beta-adrenoreceptor-mediated inotropic responses and promoting myocyte apoptosis, may nevertheless induce pump

  17. Endoscopic balloon dilatation of Crohn’s-associated intestinal strictures: High patient satisfaction and long-term efficacy

    PubMed Central

    Rueda Guzmán, Anna; Wehkamp, Jan; Kirschniak, Andreas; Naumann, Aline; Malek, Nisar P.

    2016-01-01

    Introduction Stricture formation is a common long-term complication of Crohn’s disease. Endoscopic balloon dilatation offers a bowel-sparing treatment option, but long-term outcome and its association with patient-, stricture-, and procedure-related factors is only poorly understood. Patient satisfaction with endoscopic balloon dilatation is largely unknown. Methods We performed a retrospective review of all endoscopic balloon dilatation for Crohn’s disease-related strictures between January 2005 and January 2013. Long-term outcome, complication rates and predictive factors were evaluated. Patient satisfaction was assessed using a questionnaire and telephone interviews. Results A total of 118 balloon dilatations were performed for 69 strictures in 46 patients. One patient was excluded from further analysis due to malignancy. Median time from diagnosis of Crohn’s disease to symptomatic stricture formation was 19 years. Technical success, defined as passage of the endoscope after dilatation, was reportedly obtained in 95 of 106 procedures (89.6%). Two perforations occurred, one of which could be managed conservatively. No episodes of severe bleeding were recorded (procedure-related complication rate: 2/118; 1.7%). During a median follow-up of 4.8 years (range 0.4–8.7), 55.6% (25/45) of patients were able to avoid surgery. Of the patients, 35.6% (16/45) did not need any further intervention, 40.0% (18/45) underwent more than one dilatation, and 24.4% (11/45) were operated after the first dilatation. The percentage of patients who were satisfied with the procedure and would again opt for balloon dilation as first line therapy was 83.3% (35/42). None of the risk factors examined in this study correlated with the necessity for subsequent surgery. Discussion Endoscopic balloon dilatation is a safe and effective first line therapy for Crohn’s disease-related strictures. No technical, stenosis-, or patient-related factor reliably predicted sustained dilatation

  18. Familial Dilated Cardiomyopathy Caused by a Novel Frameshift in the BAG3 Gene

    PubMed Central

    Moncayo-Arlandi, Javier; Allegue, Catarina; Iglesias, Anna; Mangas, Alipio; Brugada, Ramon

    2016-01-01

    Background Dilated cardiomyopathy, a major cause of chronic heart failure and cardiac transplantation, is characterized by left ventricular or biventricular heart dilatation. In nearly 50% of cases the pathology is inherited, and more than 60 genes have been reported as disease-causing. However, in 30% of familial cases the mutation remains unidentified even after comprehensive genetic analysis. This study clinically and genetically assessed a large Spanish family affected by dilated cardiomyopathy to search for novel variations. Methods and Results Our study included a total of 100 family members. Clinical assessment was performed in alive, and genetic analysis was also performed in alive and 1 deceased relative. Genetic screening included resequencing of 55 genes associated with sudden cardiac death, and Sanger sequencing of main disease-associated genes. Genetic analysis identified a frame-shift variation in BAG3 (p.H243Tfr*64) in 32 patients. Genotype-phenotype correlation identified substantial heterogeneity in disease expression. Of 32 genetic carriers (one deceased), 21 relatives were clinically affected, and 10 were asymptomatic. Seventeen of the symptomatic genetic carriers exhibited proto-diastolic septal knock by echocardiographic assessment. Conclusions We report p.H243Tfr*64_BAG3 as a novel pathogenic variation responsible for familial dilated cardiomyopathy. This variation correlates with a more severe phenotype of the disease, mainly in younger individuals. Genetic analysis in families, even asymptomatic individuals, enables early identification of individuals at risk and allows implementation of preventive measures. PMID:27391596

  19. Familial dilated cardiomyopathy: A multidisciplinary entity, from basic screening to novel circulating biomarkers.

    PubMed

    de Gonzalo-Calvo, D; Quezada, M; Campuzano, O; Perez-Serra, A; Broncano, J; Ayala, R; Ramos, M; Llorente-Cortes, V; Blasco-Turrión, S; Morales, F J; Gonzalez, P; Brugada, R; Mangas, A; Toro, R

    2017-02-01

    Idiopathic dilated cardiomyopathy has become one of the most prevalent inherited cardiomyopathies over the past decades. Genetic screening of first-degree relatives has revealed that 30-50% of the cases have a familial origin. Similar to other heart diseases, familial dilated cardiomyopathy is characterized by a high genetic heterogeneity that complicates family studies. Cli'nical screening, 12-lead electrocardiogram and transthoracic echocardiogram are recommended for patients and first-degree family members. Magnetic resonance also needs to be considered. Genetic technologies have become fundamental for the clinical management of this disease. New generation sequencing methods have made genetic testing feasible for extensive panels of genes related to the disease. Recently, new imaging modalities such as speckle-tracking, strain and strain rate or magnetic resonance, and circulating biomarkers such as non-coding RNAs, have emerged as potential strategies to help cardiologists in their clinical practice. Imaging, genetic and blood-based techniques should be considered together in the evaluation and testing of familial dilated cardiomyopathy. Here, we discuss the current procedures and novel approaches for the clinical management of familial dilated cardiomyopathy.

  20. Gravitational time dilation induced decoherence in spontaneous emission

    NASA Astrophysics Data System (ADS)

    Xie, Dong; Xu, Chunling; Wang, An Min

    2017-08-01

    We investigate decoherence of quantum superpositions induced by gravitational time dilation and spontaneous emission between two atomic levels. It has been shown that gravitational time dilation can be a universal decoherence source by Pikovski et al. Here, we consider the decoherence induced by the gravitational time dilation only in the situation of spontaneous emission. We obtain the analytical results of the coherence of particle’s position state. Then, we obtain that the coherence of particle’s position state depends on reference frame because the time dilation changes the distinguishability of emitted photons from two positions of particle in different reference frames. For observing the decoherence effect induced by the gravitational time dilation, time-delayed feedback can be utilized to increase the decoherence of particle’s superposition state.

  1. Dilation of fusion pores by crowding of SNARE proteins.

    PubMed

    Wu, Zhenyong; Bello, Oscar D; Thiyagarajan, Sathish; Auclair, Sarah Marie; Vennekate, Wensi; Krishnakumar, Shyam S; O'Shaughnessy, Ben; Karatekin, Erdem

    2017-03-27

    Hormones and neurotransmitters are released through fluctuating exocytotic fusion pores that can flicker open and shut multiple times. Cargo release and vesicle recycling depend on the fate of the pore, which may reseal or dilate irreversibly. Pore nucleation requires zippering between vesicle-associated v- and target membrane t-SNAREs, but the mechanisms governing the subsequent pore dilation are not understood. Here, we probed dilation of single fusion pores using v-SNARE-reconstituted ~23 nm diameter discoidal nanolipoprotein particles (vNLPs) as fusion partners with cells ectopically expressing cognate, 'flipped' t-SNAREs. Pore nucleation required a minimum of 2, and reached a maximum above ~4 copies per face, but the probability of pore dilation was far from saturating at 15 copies, the NLP capacity. Our experimental and computational results suggest SNARE availability may be pivotal in determining whether neurotransmitters or hormones are released through a transient (kiss & run) or an irreversibly dilating pore (full fusion).

  2. Denture-Related Stomatitis Is Associated with Endothelial Dysfunction

    PubMed Central

    Osmenda, Grzegorz; Nowakowski, Daniel; Wilk, Grzegorz; Maciąg, Anna; Mikołajczyk, Tomasz; Sagan, Agnieszka; Filip, Magdalena; Dróżdż, Mirosław; Guzik, Tomasz J.

    2014-01-01

    Oral inflammation, such as periodontitis, can lead to endothelial dysfunction, accelerated atherosclerosis, and vascular dysfunction. The relationship between vascular dysfunction and other common forms of oral infections such as denture-related stomatitis (DRS) is unknown. Similar risk factors predispose to both conditions including smoking, diabetes, age, and obesity. Accordingly, we aimed to investigate endothelial function and major vascular disease risk factors in 44 consecutive patients with dentures with clinical and microbiological features of DRS (n = 20) and without DRS (n = 24). While there was a tendency for higher occurrence of diabetes and smoking, groups did not differ significantly in respect to major vascular disease risk factors. Groups did not differ in main ambulatory blood pressure, total cholesterol, or even CRP. Importantly, flow mediated dilatation (FMD) was significantly lower in DRS than in non-DRS subjects, while nitroglycerin induced vasorelaxation (NMD) or intima-media thickness (IMT) was similar. Interestingly, while triglyceride levels were normal in both groups, they were higher in DRS subjects, although they did not correlate with either FMD or NMD. Conclusions. Denture related stomatitis is associated with endothelial dysfunction in elderly patients with dentures. This is in part related to the fact that diabetes and smoking increase risk of both DRS and cardiovascular disease. PMID:25045683

  3. [Esophageal dilatation by Savary-Guillard bougies in children].

    PubMed

    Asensio Llorente, M; Broto Mangues, J; Gil-Vernet Huguet, J M; Acosta Farina, D; Marhuenda Irastorza, C; Boix-Ochoa, J

    1999-01-01

    Dilatations are considered the election treatment for esophageal stenosis of different etiologies. Different methods of dilatation have been used through the years. Security and effectiveness are the main subjects when we choose a dilatation method. We present the results of the last 3 years that Savary-Guilliard have been used, with a guide wire probe, under endoscopic control. Six patients with postsurgical stenosis and 10 with post lye ingestion stenosis were treated with the above mentioned method. The site of stenosis is localized under flexible endoscopy, and a special guide wire probe is introduced to the stomach. Once the wire is in place, different diameter bougies are introduced until a firm resistance is felt or the desired diameter is reach. In complicated cases the progression of the wire was controlled by X-rays. A total of 208 dilatations have done in 16 patients over the last three years. Six patients with postsurgical stenosis needed from two to six dilatations for their cure. Of the 10 patients who ingest lye, none of them had needed a gastrostomy. Three of them have no dysphagia after 9, 13 and 13 dilatations. The other 7 are under dilatations every 6 weeks in 6 cases and every 4 weeks in one case, been all of them in the second year of treatment. All the dilatations have been performed under general anesthesia, as outpatients. We have not had any complication under this treatment. We have found that the Savary-Guilliard method is adequate for esophageal dilatations in pediatric population. Security and effectiveness are the main points of this procedure, there is no need for a gastrostomy, and the child will have a better quality of life. This procedure is less aggressive, and this will give a shorter postop period, with no complications and the child will have a longer period of normal life between dilatations.

  4. Dietary taurine deficiency and dilated cardiomyopathy in the fox.

    PubMed

    Moise, N S; Pacioretty, L M; Kallfelz, F A; Stipanuk, M H; King, J M; Gilmour, R F

    1991-02-01

    Taurine deficiency has been implicated as a potential cause of dilated cardiomyopathy. However, the relationship between taurine and myocardial function is presently unclear. The purpose of this study was to determine whether dilated cardiomyopathy in the fox is associated with dietary taurine deficiency. A total of 68 foxes from farms with a history of death caused by dilated cardiomyopathy and 14 foxes from a farm with no history of dilated cardiomyopathy were studied. Dilated cardiomyopathy was diagnosed by echocardiography in 48% of the foxes from one farm with a positive history and in none of the foxes from the control farm. Foxes less than 9 months of age were more commonly affected than older foxes (p = 0.03). Plasma taurine concentrations were significantly less (p less than 0.01) in foxes that had dilated cardiomyopathy (26.8 +/- 16.4 nmol/ml) than in the control foxes (99.3 +/- 60.2 nmol/ml). A significantly higher (p less than 0.01) incidence of dilated cardiomyopathy was present in foxes with a history of a sibling or offspring that died of dilated cardiomyopathy than in foxes without a family history of cardiac death. In one fox with dilated cardiomyopathy that was tested, the myocardial taurine concentration was lower (1.7 mumol/gm wet weight) than that of control foxes (7.3 +/- 1.6 mumol/gm wet weight). Hepatic cysteinesulfinic acid decarboxylase activity was significantly less (p less than 0.001) in foxes with dilated cardiomyopathy (0.97 +/- 0.2 nmol/mm.mg protein) than in control foxes (2.11 +/- 0.07 nmol CO2/mm.mg protein).(ABSTRACT TRUNCATED AT 250 WORDS)

  5. Flow-mediated vasodilation as a predictor of therapeutic response to midodrine hydrochloride in children with postural orthostatic tachycardia syndrome.

    PubMed

    Liao, Ying; Yang, Jinyan; Zhang, Fengwen; Chen, Stella; Liu, Xueqin; Zhang, Qingyou; Ai, Yi; Wang, Yuli; Tang, Chaoshu; Du, Junbao; Jin, Hongfang

    2013-09-15

    This study was designed to explore the value of flow-mediated vasodilation (FMD) as a predictor of therapeutic response to midodrine hydrochloride (MD) in children with postural orthostatic tachycardia syndrome (POTS). One hundred and eight children diagnosed with POTS and 20 healthy control children were enrolled. All children with POTS received MD and were followed up for 3 months. FMD of brachial artery for each participant was measured by vascular ultrasound. Symptom scores, FMD values, and head-up test (HUT)/head-up tilt test (HUTT) outcomes were investigated before and after treatment. A receiver operating characteristic curve was used to explore the value of FMD as a predictor. Baseline FMD (%) and increased heart rate (beats per minute) during HUT/HUTT were significantly greater in children with POTS compared with control children (FMD: 11 ± 3% vs 6 ± 2%, p <0.001; increased heart rate: 38 ± 9 vs 7 ± 7 beats/min, p <0.001, respectively). Before treatment, MD responders had greater FMD values than MD nonresponders (p <0.05). Symptom scores, excessive increases in heart rate during HUT, and increased FMD values were all reduced significantly after treatment (all p <0.05). The receiver operating characteristic curve for the predictive value of FMD showed the area under the curve to be 0.790 (95% confidence interval: 0.679 to 0.902; p <0.001) at 1-month and 0.803 (95% confidence interval: 0.669 to 0.936; p <0.01) at 3-month therapy. FMD of 9.85% had a high sensitivity (1-month therapy: 71.6%; 3-month therapy: 74.4%) and specificity (1-month therapy 77.8%; 3-month therapy: 80%). In conclusion, FMD is a predictor of the efficacy of MD for treating children with POTS.

  6. Impaired flow-mediated vasodilatation is associated with increased left ventricular mass in a multiethnic population. The Northern Manhattan Study.

    PubMed

    Hasegawa, Takuya; Boden-Albala, Bernadette; Eguchi, Kazuo; Jin, Zhezhen; Sacco, Ralph L; Homma, Shunichi; Di Tullio, Marco R

    2010-04-01

    Increased left ventricular (LV) mass and endothelial dysfunction are important risk factors for cardiovascular mortality and morbidity. However, it is not clear whether endothelial dysfunction is associated with increased LV mass. We tested the hypothesis that impaired flow-mediated vasodilatation (FMD) is associated with increased LV mass in a population-based multiethnic cohort. As a part of the Northern Manhattan Study (NOMAS), we performed two-dimensional echocardiography and FMD assessment during reactive hyperemia by high-resolution ultrasonography in 867 stroke-free community participants. LV mass was calculated according to an established method. LV hypertrophy was defined as the 90th percentile of sex-specific LV mass indexed for body surface area among normal subjects. Multivariable models were used to test the association of FMD with LV mass. In multiple linear regression analysis adjusting for age, sex, body mass index, systolic blood pressure, antihypertensive medications, low-density lipoprotein cholesterol, diabetes, smoking, hematocrit, and race-ethnicity, FMD was inversely associated with LV mass (beta = -1.21 +/- 0.56, P = 0.03). The association persisted after further adjustment for any component of blood pressure (systolic, mean, and pulse pressure). In univariate logistic regression analysis, each 1% decrease in FMD was associated with an 8% higher risk of LV hypertrophy (odds ratio 1.08, 95% confidence interval 1.03-1.13 per each FMD point P < 0.01). Impaired FMD is associated with LV mass, independent of other factors associated with increased LV mass. Endothelial dysfunction might be a potential risk factor for LV hypertrophy.

  7. Effects of barnidipine in comparison with hydrochlorothiazide on endothelial function, as assessed by flow mediated vasodilatation in hypertensive patients.

    PubMed

    Muiesan, Maria Lorenza; Salvetti, Massimo; Belotti, Eugenia; Paini, Anna; Rosei, Claudia Agabiti; Aggiusti, Carlo; Scotti, Aurelio; de Ciuceis, Carolina; Rizzoni, Damiano; Rosei, Enrico Agabiti

    2011-08-01

    BACKGROUND. In hypertensive patients, endothelial dysfunction is associated with an increased incidence of cardiovascular events. Calcium-channel antagonists can reverse impaired endothelium-dependent vasodilation in different vascular districts, while conflicting results are found in the brachial artery. Aim. To investigate the effect of barnidipine in comparison with hydrochlorothiazide on endothelial function of hypertensives, as assessed by flow-mediated vasodilation (FMD) of the brachial artery. METHODS. Patients with mild to moderate hypertension (age range 26-67 years) were randomized to receive barnidipine or hydrochlorothiazide. A thorough clinical examination, including blood pressure (BP) measurement, was performed at randomization as well as after 6, 12 and 24 weeks. FMD and 24-h BP monitoring was performed at randomization, after 12 and 24 weeks. RESULTS. After 12 and 24 weeks of treatment, a significant reduction in clinic BP was observed in both groups. Furthermore, a significant reduction in 24-h SBP and DBP was observed in patients receiving barnidipine but not in those receiving diuretic. The percentage change in FMD was different between the two groups of patients treated with barnidipine (at 12 weeks +1.2 ± 2.2%, p = 0.023 and at 24 weeks +1.25 ± 3.15%, p = 0.16 from baseline) or with hydrochlorothiazide (at 12 weeks -1.0 ± 3.0. p = 0.09 and at 24 weeks -1.78 ± 2.9%, p = 0.015 from baseline). A significant difference in FMD changes between the two groups was confirmed by analysis of covariance (p = 0.031). CONCLUSIONS. In presence of a similar clinic BP reduction, an improvement of endothelial function was observed during treatment with barnidipine but not with hydrochlorothiazide, suggesting that the barnidipine may exert a favourable effect on endothelial dysfunction in hypertensive patients.

  8. Flow-Mediated Vasodilatation and Intima-Media Thickness in Patients with Coexisting Heart Failure and Diabetes Receiving Medical Therapy

    PubMed Central

    Andersen, Lisbeth Vestergaard; Wiinberg, Niels; Tuxen, Christian; Kjær, Andreas

    2011-01-01

    Objective Intensive medical treatment of heart failure (HF) patients with diabetes may reduce the endothelial dysfunction and the accelerated atherosclerotic process seen in these patients. To study this, we investigated the endothelial function and the presence of atherosclerosis as measured by flow-mediated vasodilatation (FMD) and intima-media thickness (IMT) in intensively treated patients with coexisting HF and diabetes. Research Design and Method FMD of the brachial artery and IMT of the common carotid arteries were determined in 26 patients with systolic HF and diabetes who were in intensive medical therapy, as well as in 19 healthy controls. The two groups were matched according to age and sex. In all subjects left ventricular ejection fraction was measured by two-dimensional echocardiography. Biochemical parameters including serum cholesterol, HDL and LDL, triglyceride, glucose, hemoglobin/hemoglobin-A1C (HbA1C), brain natriuretic peptide (BNP) and N-terminal pro-BNP were also assessed. Results Mean FMD and IMT did not differ significantly between patients and controls. Left ventricular ejection fraction was lower in patients compared to controls (P < 0.001). The patients had a higher mean BNP, NT pro-BNP, triglyceride, HbA1C and glucose in comparison to controls. Cholesterol, HDL-cholesterol and LDL-cholesterol were lower in patients compared to controls. Conclusions Intensively treated patients with coexisting systolic HF and diabetes seem to have normal endothelial function as measured by FMD and they have no sign of accelerated atherosclerosis as measured by IMT. This suggests a positive effect of medication on the cardiovascular alterations in this group of patients. PMID:26859486

  9. Combination of Flow-Mediated Vasodilation and Nitroglycerine-Induced Vasodilation Is More Effective for Prediction of Cardiovascular Events.

    PubMed

    Kajikawa, Masato; Maruhashi, Tatsuya; Hida, Eisuke; Iwamoto, Yumiko; Matsumoto, Takeshi; Iwamoto, Akimichi; Oda, Nozomu; Kishimoto, Shinji; Matsui, Shogo; Hidaka, Takayuki; Kihara, Yasuki; Chayama, Kazuaki; Goto, Chikara; Aibara, Yoshiki; Nakashima, Ayumu; Noma, Kensuke; Higashi, Yukihito

    2016-05-01

    Measurement of nitroglycerine-induced vasodilation has been performed to differentiate endothelium-dependent vasodilation from endothelium-independent vasodilation as a control test for flow-mediated vasodilation (FMD). Recently, nitroglycerine-induced vasodilation per se has been reported to be a useful marker of the grade of atherosclerosis. The present study aimed to evaluate the prognostic value of FMD combined with nitroglycerine-induced vasodilation for future cardiovascular events. We measured FMD and nitroglycerine-induced vasodilation in 402 subjects, including patients with cardiovascular diseases. During a median follow-up period of 32.3 months, 38 first major cardiovascular events (death from cardiovascular causes, acute myocardial infarction, stroke, and coronary revascularization) occurred. Receiver-operator characteristic curve analysis revealed that FMD alone and nitroglycerine-induced vasodilation alone can predict cardiovascular events with areas under the curve of 0.671 (cutoff 3.3%) and 0.692 (cutoff 11.6%), respectively. FMD combined with nitroglycerine-induced vasodilation predicts cardiovascular events with an area under the curve of 0.701. After adjustment for age, sex, and cardiovascular risk factors, above cutoff FMD (≥3.3%) and below cutoff nitroglycerine-induced vasodilation (<11.6%; hazard ratio, 5.55; 95% confidence interval, 1.61-25.46;P=0.006) and below cutoff FMD (<3.3%) and below cutoff nitroglycerine-induced vasodilation (<11.6%; hazard ratio, 7.20; 95% confidence interval, 2.37-31.36;P<0.001) remained strong independent indicator of cardiovascular events. These findings suggest that the combination of FMD and nitroglycerine-induced vasodilation measurements can more accurately predict cardiovascular events compared with FMD alone. URL: http://www.clinicaltrials.gov. Unique identifier: UMIN000001167. © 2016 American Heart Association, Inc.

  10. Remote arteriolar dilations caused by methacholine: a role for CGRP sensory nerves?

    PubMed

    Thengchaisri, Naris; Rivers, Richard J

    2005-08-01

    Remote vasodilation caused by arteriolar microapplication of acetylcholine cannot be completely attributed to passive cell-cell communication of a hyperpolarizing signal. The present study was undertaken to ascertain whether a neural component may be involved in the remote response. In the cheek pouch of anesthetized hamsters, methacholine (100 microM) was applied to the arteriole by micropipette for 5 s, and the arteriolar responses were measured at the site of application and at remote locations: 500 and 1,000 microm upstream from the application site. Superfusion with the local anesthetic bupivacaine attenuated a local dilatory response and abolished the conducted dilation response to methacholine. Localized micropipette application of bupivacaine 300 microm from the methacholine application site also attenuated the remote dilation but did not inhibit the local dilation. Blockade of neuromuscular transmission with botulinum neurotoxin A (1 U, 3 days), micropipette application of calcitonin gene-related peptide (CGRP) receptor inhibitor CGRP-(8-37) (10 microM) 300 microm upstream from the methacholine application site, and denervation of the CGRP sensory nerve by 2 days of capsaicin treatment reduced the conducted dilation response to methacholine but did not affect the local dilatory response. Together, these data support involvement of a TTX-insensitive nerve, specifically the CGRP containing nerve, in vascular communication. Understanding the effect of regulation of a novel neural network system on the vascular network may lead to a new insight into regulation of blood flow and intraorgan blood distribution.

  11. Post-yield Strength and Dilatancy Evolution Across the Brittle-Ductile Transition in Indiana Limestone

    NASA Astrophysics Data System (ADS)

    Walton, G.; Hedayat, A.; Kim, E.; Labrie, D.

    2017-07-01

    An extensive uniaxial and triaxial compression testing programme was performed on Indiana Limestone to assess its behaviour across the brittle-ductile transition. Particular attention has been paid to the post-yield evolution of strength and dilatancy. Specimens tested at σ 3 = 30 MPa displayed a fully ductile failure mechanism, whereas specimens tested at σ 3 = 15 MPa and σ 3 = 20 MPa displayed transitional mechanisms, which were neither fully brittle nor fully ductile. Based on an examination of failure localization and dilatancy characteristics, the stress at which crack volumetric strain begins to increase was found to be an indicator of individual specimen ductility. In contrast to less porous rocks, the reversal of total volumetric strain did not coincide with the onset of axial strain nonlinearity under unconfined conditions. With respect to post-yield strength, a major change in the rate of friction mobilization relative to plastic shear strain was observed across the brittle-ductile transition. The dilatancy of the specimens was also found to undergo a major change, with the plastic shear strains to mobilization of peak dilatancy in the ductile regime being approximately one order of magnitude higher than in the brittle regime.

  12. Dynamic functional modules in co-expressed protein interaction networks of dilated cardiomyopathy

    PubMed Central

    2010-01-01

    Background Molecular networks represent the backbone of molecular activity within cells and provide opportunities for understanding the mechanism of diseases. While protein-protein interaction data constitute static network maps, integration of condition-specific co-expression information provides clues to the dynamic features of these networks. Dilated cardiomyopathy is a leading cause of heart failure. Although previous studies have identified putative biomarkers or therapeutic targets for heart failure, the underlying molecular mechanism of dilated cardiomyopathy remains unclear. Results We developed a network-based comparative analysis approach that integrates protein-protein interactions with gene expression profiles and biological function annotations to reveal dynamic functional modules under different biological states. We found that hub proteins in condition-specific co-expressed protein interaction networks tended to be differentially expressed between biological states. Applying this method to a cohort of heart failure patients, we identified two functional modules that significantly emerged from the interaction networks. The dynamics of these modules between normal and disease states further suggest a potential molecular model of dilated cardiomyopathy. Conclusions We propose a novel framework to analyze the interaction networks in different biological states. It successfully reveals network modules closely related to heart failure; more importantly, these network dynamics provide new insights into the cause of dilated cardiomyopathy. The revealed molecular modules might be used as potential drug targets and provide new directions for heart failure therapy. PMID:20950417

  13. Unexpected death caused by rupture of a dilated aorta in an adult male with aortic coarctation.

    PubMed

    Leth, Peter Mygind; Knudsen, Peter Thiis

    2015-09-01

    Aortic coarctation (AC) is a congenital aortic narrowing. We describe for the first time the findings obtained by unenhanced post mortem computed tomography (PMCT) in a case where the death was caused by cardiac tamponade from a ruptured aneurysmal dilatation of the ascending aorta and the aortic arch without dissection combined with aortic coarctation. The patient, a 46-year-old man, was found dead at home. PMCT showed haemopericardium and dilatation of the ascending aorta and the aortic arch. This appearance led to the mistaken interpretation that the images represented a dissecting aneurysm. The autopsy showed instead a thin-walled and floppy dilatation of the ascending aorta and aortic arch with a coarctation just proximal to the ligamentum arteriosum. A longitudinal tear was found in the posterior aortic wall just above the valves. Blood in the surrounding soft tissue intersected with a large haematoma (1000ml) in the pericardial sac. Cardiac hypertrophy (556g) was observed in the patient, though no other cardiovascular abnormalities were found. Histological analysis showed cystic medial necrosis of the ascending aortic wall. A ruptured aneurysmal dilatation of the ascending aorta and the aortic arch without aortic dissection associated with AC is an uncommon cause of haemopericardium that has only been described a few times before. The case is discussed in relation to other reported cases and in the context of the present understanding of this condition.

  14. Dilatant shear band formation and diagenesis in calcareous, arkosic sandstones, Vienna Basin (Austria).

    PubMed

    Lommatzsch, Marco; Exner, Ulrike; Gier, Susanne; Grasemann, Bernhard

    2015-04-01

    The present study examines deformation bands in calcareous arkosic sands. The investigated units can be considered as an equivalent to the Matzen field in the Vienna Basin (Austria), which is one of the most productive oil reservoirs in central Europe. The outcrop exposes carbonate-free and carbonatic sediments of Badenian age separated by a normal fault. Carbonatic sediments in the hanging wall of the normal fault develop dilation bands with minor shear displacements (< 2 mm), whereas carbonate-free sediments in the footwall develop cataclastic shear bands with up to 70 cm displacement. The cataclastic shear bands show a permeability reduction up to 3 orders of magnitude and strong baffling effects in the vadose zone. Carbonatic dilation bands show a permeability reduction of 1-2 orders of magnitude and no baffling structures. We distinguished two types of deformation bands in the carbonatic units, which differ in deformation mechanisms, distribution and composition. Full-cemented bands form as dilation bands with an intense syn-kinematic calcite cementation, whereas the younger loose-cemented bands are dilatant shear bands cemented by patchy calcite and clay minerals. All analyzed bands are characterized by a porosity and permeability reduction caused by grain fracturing and cementation. The changed petrophysical properties and especially the porosity evolution are closely related to diagenetic processes driven by varying pore fluids in different diagenetic environments. The deformation band evolution and sealing capacity is controlled by the initial host rock composition.

  15. Dilatant shear band formation and diagenesis in calcareous, arkosic sandstones, Vienna Basin (Austria)

    PubMed Central

    Lommatzsch, Marco; Exner, Ulrike; Gier, Susanne; Grasemann, Bernhard

    2015-01-01

    The present study examines deformation bands in calcareous arkosic sands. The investigated units can be considered as an equivalent to the Matzen field in the Vienna Basin (Austria), which is one of the most productive oil reservoirs in central Europe. The outcrop exposes carbonate-free and carbonatic sediments of Badenian age separated by a normal fault. Carbonatic sediments in the hanging wall of the normal fault develop dilation bands with minor shear displacements (< 2 mm), whereas carbonate-free sediments in the footwall develop cataclastic shear bands with up to 70 cm displacement. The cataclastic shear bands show a permeability reduction up to 3 orders of magnitude and strong baffling effects in the vadose zone. Carbonatic dilation bands show a permeability reduction of 1-2 orders of magnitude and no baffling structures. We distinguished two types of deformation bands in the carbonatic units, which differ in deformation mechanisms, distribution and composition. Full-cemented bands form as dilation bands with an intense syn-kinematic calcite cementation, whereas the younger loose-cemented bands are dilatant shear bands cemented by patchy calcite and clay minerals. All analyzed bands are characterized by a porosity and permeability reduction caused by grain fracturing and cementation. The changed petrophysical properties and especially the porosity evolution are closely related to diagenetic processes driven by varying pore fluids in different diagenetic environments. The deformation band evolution and sealing capacity is controlled by the initial host rock composition. PMID:26300577

  16. Anatomical and clinical predictors of valve dysfunction and aortic dilation in bicuspid aortic valve disease.

    PubMed

    Evangelista, Arturo; Gallego, Pastora; Calvo-Iglesias, Francisco; Bermejo, Javier; Robledo-Carmona, Juan; Sánchez, Violeta; Saura, Daniel; Arnold, Roman; Carro, Amelia; Maldonado, Giuliana; Sao-Avilés, Augusto; Teixidó, Gisela; Galian, Laura; Rodríguez-Palomares, José; García-Dorado, David

    2017-09-01

    Bicuspid aortic valve (BAV) is associated with early valvular dysfunction and proximal aorta dilation with high heterogeneity. This study aimed to assess the determinants of these complications. Eight hundred and fifty-two consecutive adults diagnosed of BAV referred from cardiac outpatient clinics to eight echocardiographic laboratories of tertiary hospitals were prospectively recruited. Exclusion criteria were aortic coarctation, other congenital disorders or intervention. BAV morphotype, significant valve dysfunction and aorta dilation (≥2 Z-score) at sinuses and ascending aorta were established. Three BAV morphotypes were identified: right-left coronary cusp fusion (RL) in 72.9%, right-non-coronary (RN) in 24.1% and left-non-coronary (LN) in 3.0%. BAV without raphe was observed in 18.3%. Multivariate analysis showed aortic regurgitation (23%) to be related to male sex (OR: 2.80, p<0.0001) and valve prolapse (OR: 5.16, p<0.0001), and aortic stenosis (22%) to BAV-RN (OR: 2.09, p<0.001), the presence of raphe (OR: 2.75, p<0.001), age (OR: 1.03; p<0.001), dyslipidaemia (OR: 1.77, p<0.01) and smoking (OR: 1.63, p<0.05). Ascending aorta was dilated in 76% without differences among morphotypes and associated with significant valvular dysfunction. By contrast, aortic root was dilated in 34% and related to male sex and aortic regurgitation but was less frequent in aortic stenosis and BAV-RN. Normofunctional valves are more prevalent in BAV without raphe. Aortic stenosis is more frequent in BAV-RN and associated with some cardiovascular risk factors, whereas aortic regurgitation (AR) is associated with male sex and sigmoid prolapse. Although ascending aorta is the most commonly dilated segment, aortic root dilation is present in one-third of patients and associated with AR. Remarkably, BAV-RL increases the risk for dilation of the proximal aorta, whereas BAV-RN spares this area. © Article author(s) (or their employer(s) unless otherwise stated in the text of the

  17. Clinical diabetic cardiomyopathy: a two-faced disease with restrictive and dilated phenotypes.

    PubMed

    Seferović, Petar M; Paulus, Walter J

    2015-07-14

    Diabetes mellitus-related cardiomyopathy (DMCMP) was originally described as a dilated phenotype with eccentric left ventricular (LV) remodelling and systolic LV dysfunction. Recently however, clinical studies on DMCMP mainly describe a restrictive phenotype with concentric LV remodelling and diastolic LV dysfunction. Both phenotypes are not successive stages of DMCMP but evolve independently to respectively heart failure with preserved left ventricular ejection fraction (HFPEF) or reduced left ventricular ejection fraction (HFREF). Phenotype-specific pathophysiological mechanisms were recently proposed for LV remodelling and dysfunction in HFPEF and HFREF consisting of coronary microvascular endothelial dysfunction in HFPEF and cardiomyocyte cell death in HFREF. A similar preferential involvement of endothelial or cardiomyocyte cell compartments explains DMCMP development into distinct restrictive/HFPEF or dilated/HFREF phenotypes. Diabetes mellitus (DM)-related metabolic derangements such as hyperglycaemia, lipotoxicity, and hyperinsulinaemia favour development of DMCMP with restrictive/HFPEF phenotype, which is more prevalent in obese type 2 DM patients. In contrast, autoimmunity predisposes to a dilated/HFREF phenotype, which manifests itself more in autoimmune-prone type 1 DM patients. Finally, coronary microvascular rarefaction and advanced glycation end-products deposition are relevant to both phenotypes. Diagnosis of DMCMP requires impaired glucose metabolism and exclusion of coronary, valvular, hypertensive, or congenital heart disease and of viral, toxic, familial, or infiltrative cardiomyopathy. In addition, diagnosis of DMCMP with restrictive/HFPEF phenotype requires normal systolic LV function and diastolic LV dysfunction, whereas diagnosis of DMCMP with dilated/HFREF phenotype requires systolic LV dysfunction. Treatment of DMCMP with restrictive/HFPEF phenotype is limited to diuretics and lifestyle modification, whereas DMCMP with dilated

  18. Studying Dynamic Myofiber Aggregate Reorientation in Dilated Cardiomyopathy Using In Vivo Magnetic Resonance Diffusion Tensor Imaging

    PubMed Central

    von Deuster, Constantin; Sammut, Eva; Asner, Liya; Nordsletten, David; Lamata, Pablo; Stoeck, Christian T.; Razavi, Reza

    2016-01-01

    Background— The objective of this study is to assess the dynamic alterations of myocardial microstructure and strain between diastole and systole in patients with dilated cardiomyopathy relative to healthy controls using the magnetic resonance diffusion tensor imaging, myocardial tagging, and biomechanical modeling. Methods and Results— Dual heart-phase diffusion tensor imaging was successfully performed in 9 patients and 9 controls. Tagging data were acquired for the diffusion tensor strain correction and cardiac motion analysis. Mean diffusivity, fractional anisotropy, and myocyte aggregate orientations were compared between both cohorts. Cardiac function was assessed by left ventricular ejection fraction, torsion, and strain. Computational modeling was used to study the impact of cardiac shape on fiber reorientation and how fiber orientations affect strain. In patients with dilated cardiomyopathy, a more longitudinal orientation of diastolic myofiber aggregates was measured compared with controls. Although a significant steepening of helix angles (HAs) during contraction was found in the controls, consistent change in HAs during contraction was absent in patients. Left ventricular ejection fraction, cardiac torsion, and strain were significantly lower in the patients compared with controls. Computational modeling revealed that the dilated heart results in reduced HA changes compared with a normal heart. Reduced torsion was found to be exacerbated by steeper HAs. Conclusions— Diffusion tensor imaging revealed reduced reorientation of myofiber aggregates during cardiac contraction in patients with dilated cardiomyopathy relative to controls. Left ventricular remodeling seems to be an important factor in the changes to myocyte orientation. Steeper HAs are coupled with a worsening in strain and torsion. Overall, the findings provide new insights into the structural alterations in patients with dilated cardiomyopathy. PMID:27729361

  19. Pupil Dilation to Explicit and Non-Explicit Sexual Stimuli.

    PubMed

    Watts, Tuesday M; Holmes, Luke; Savin-Williams, Ritch C; Rieger, Gerulf

    2017-01-01

    Pupil dilation to explicit sexual stimuli (footage of naked and aroused men or women) can elicit sex and sexual orientation differences in sexual response. If similar patterns were replicated with non-explicit sexual stimuli (footage of dressed men and women), then pupil dilation could be indicative of automatic sexual response in fully noninvasive designs. We examined this in 325 men and women with varied sexual orientations to determine whether dilation patterns to non-explicit sexual stimuli resembled those to explicit sexual stimuli depicting the same sex or other sex. Sexual orientation differences in pupil dilation to non-explicit sexual stimuli mirrored those to explicit sexual stimuli. However, the relationship of dilation to non-explicit sexual stimuli with dilation to corresponding explicit sexual stimuli was modest, and effect magnitudes were smaller with non-explicit sexual stimuli than explicit sexual stimuli. The prediction that sexual orientation differences in pupil dilation are larger in men than in women was confirmed with explicit sexual stimuli but not with non-explicit sexual stimuli.

  20. Review article: oesophageal dilation in adults with eosinophilic oesophagitis.

    PubMed

    Bohm, M E; Richter, J E

    2011-04-01

    Eosinophilic oesophagitis is a chronic inflammatory disorder of the oesophagus, characterised by the proton pump inhibitor-refractory accumulation of eosinophils in the oesophageal epithelium (>15 intraepithelial eosinophils/high powered field). Adults present with solid food dysphagia and recurrent food impactions. Oesophageal remodelling produces the characteristic endoscopic feature of adult eosinophilic oesophagitis including strictures, rings and a narrow calibre oesophagus. To evaluate the safety and efficacy of oesophageal dilation as the initial therapy for adults with eosinophilic oesophagitis. Medline search from 1975 to November 2010 for all reports of the treatment of patients with eosinophilic oesophagitis using search words: eosinophilic oesophagitis treatment, dilation and eosinophilic oesophagitis, steroids and eosinophilic oesophagitis. Our systematic review found that 92% of patients treated with oesophageal dilation had improvement in their dysphagia symptoms for up to 1-2 years. Three case series clearly showed clinical resolution of dysphagia symptoms, independent of the degree of eosinophil infiltration, which was unchanged after dilation. Postprocedure pain for several days is common, due to some degree of mucosal tear, but true perforation very rare (<0.1%). Oesophageal dilation is an acceptable option for healthy adult eosinophilic oesophagitis patients with anatomic narrowing, possibly followed by a course of topical steroids to reduce inflammation and retard remodelling. Future studies should include a head-to-head comparison of topical steroids and oesophageal dilation, bougie vs through-the-scope balloon dilation and maintenance topical steroids compared with on-demand treatment. © 2011 Blackwell Publishing Ltd.

  1. Muscles involved in naris dilation and nose motion in rat

    PubMed Central

    Deschênes, Martin; Haidarliu, Sebastian; Demers, Maxime; Moore, Jeffrey; Kleinfeld, David; Ahissar, Ehud

    2016-01-01

    In a number of mammals muscle dilator nasi (naris) is known as a muscle that reduces nasal airflow resistance by dilating the nostrils. Here we show that in rats the tendon of this muscle inserts into the aponeurosis above the nasal cartilage. Electrical stimulation of this muscle lifts the nose and deflects it sideway towards the side of stimulation, but does not change the size of the nares. In the head-fixed alert rat, electromyographic activity of muscle dilator nasi is tightly coupled to nose motion, not to opening of the nares. Yet, contraction of muscle dilator nasi occurs during the pre-inspiratory phase of the respiratory cycle, suggesting a role in sniffing and sampling odorants. We also show that opening of the nares results from contraction of pars maxillaris profunda of the muscle nasolabialis profundus. This muscle attaches to the outer wall of the nasal cartilage and to the plate of the mystacial pad. Contraction of this muscle exerts a dual action: it pulls the lateral nasal cartilage outwardly, thus dilating the naris, and it drags the plate of the mystacial pad rostralward, provoking a slight retraction of the whiskers. On the basis of these results, we propose that muscle dilator nasi of the rat be renamed muscle deflector nasi, and that pars maxillaris profunda of the muscle nasolabialis profundus be named muscle dilator nasi. PMID:25257748

  2. The dilated bowel: a liability and an asset.

    PubMed

    Bianchi, A; Morabito, A

    2009-11-01

    The gastrointestinal tract responds to significant mechanical or functional obstruction by dilatation and hypertrophy of the segment proximal to the obstruction. Excessive dilatation compromises motility, and absorption and is associated with considerable morbidity (intraluminal stasis, sepsis) such that bowel dilatation represents a major liability that predisposes the patient to intestinal failure. The dilated bowel proximal to an obstruction provides valuable autologous material for reconstruction with "tissue appropriate to the part." Bowel elongation and dilatation are integral to the natural intestinal adaptation response to loss of small bowel and can also be induced through a structured "Bowel Expansion" program. The additional absorptive tissue that is progressively generated is essential for reconstruction of the bowel (tailoring and lengthening), to restore gastrointestinal dynamics (effective propulsion and absorption), and to reduce morbidity (intraluminal stasis, sepsis). In enhancing the prospects for enteral autonomy, dilatation and elongation of the residual autologous bowel are crucial to long-term survival and good quality life, and represent a most welcome asset. This paper reviews the impact and management of bowel dilatation along the gastrointestinal tract.

  3. Evaluation of left ventricular enlargement as a marker of early disease in familial dilated cardiomyopathy.

    PubMed

    Fatkin, Diane; Yeoh, Thomas; Hayward, Christopher S; Benson, Victoria; Sheu, Angela; Richmond, Zara; Feneley, Michael P; Keogh, Anne M; Macdonald, Peter S

    2011-08-01

    Echocardiographic screening of families with dilated cardiomyopathy has identified a subgroup of asymptomatic relatives with left ventricular enlargement (LVE). The prognostic significance of LVE in this setting is incompletely understood. We evaluated 457 asymptomatic relatives in 128 dilated cardiomyopathy families and identified 110 individuals (24%) with LVE. Serial echocardiograms in 72 untreated LVE relatives showed that 9 individuals (13%) had development of dilated cardiomyopathy over 10 to 152 months (median, 52). Thirty LVE relatives and 30 age- and sex-matched healthy control subjects were evaluated using 2-dimensional and M-mode echocardiography, tissue Doppler imaging, noninvasive pressure-volume assessment, exercise stress echocardiography, and brain natriuretic peptide levels. LVE relatives showed mild defects of systolic and diastolic LV function, with normal filling pressures and exercise-induced increments in systolic contraction in most cases. LV dimensions and fractional shortening most effectively differentiated LVE relatives from control subjects, with other functional indices lacking additive discriminative value. In a receiver operating characteristics analysis, the area under the curve for LV end-diastolic diameter (% predicted) was 0.96 (P<0.001). LV end-diastolic diameter (% predicted) >116% or LV end-diastolic diameter (% predicted) 112% to 116%+fractional shortening ≤29% had high sensitivity (100%) and specificity (93%) for LVE relatives and identified 8 of 9 progressors. LVE is a common finding in asymptomatic relatives in dilated cardiomyopathy families and can be a marker of preclinical cardiomyopathy. Assessment of LV size and contractile function is required for differentiating between pathological and physiological causes of LVE and may help to identify those at risk of disease progression.

  4. C-Reactive protein in dilated cardiomyopathy.

    PubMed

    Kaneko, K; Kanda, T; Yamauchi, Y; Hasegawa, A; Iwasaki, T; Arai, M; Suzuki, T; Kobayashi, I; Nagai, R

    1999-01-01

    The prognosis for patients with idiopathic dilated cardiomyopathy (DCM) is poor, although clinical features are variable. Prediction of outcome has been difficult in individual patients based on laboratory data. In some patients with DCM, myocardial damage secondary to viral or immune-mediated myocardial inflammation may persist. To objectively assess inflammation, we measured plasma concentrations of C-reactive protein (CRP) in 188 patients with idiopathic DCM over 5-8 years. All had dyspnea and fatigue at rest; all patients had a left ventricular ejection fraction less than 40% by echocardiography or by contrast or radionuclide ventriculography. We divided these patients into two groups: patients dying within 5 years following admission (n = 49) and the remainder surviving for at least 5 years (n = 139). CRP concentrations in the patients dying early were significantly higher than in the long-term survivors (1. 05 +/- 1.37 vs. 0.49 +/- 1.04 mg/dl, p < 0.05). Sixty-two percent of the patients with CRP>1.0 died within 5 years. In addition to other laboratory tests including electrocardiography and echocardiography, routine CRP measurements proved to be valuable for identifying high-risk patients who require special treatment strategies.

  5. [Nonischemic dilated cardiomyopathy. Parameters of autonomic tone].

    PubMed

    Demming, Thomas; Sandrock, Sarah; Bonnemeier, Hendrik

    2015-03-01

    Nonischemic dilated cardiomyopathies (DCM) are the most common reason for heart failure in developed countries after ischemic disease. They often lead to device therapy. Left ventricular ejection fraction as a single parameter to identify patients at risk for sudden cardiac death revealed inconclusive data in patients with DCM. Autonomic tone, measured by classical and innovative parameters of heart rate variability (HRV), heart rate turbulence or baroreceptor reflex, was demonstrated to give valuable prognostic information especially in patients with ischemic disease and after acute myocardial infarction. In patients with DCM, classical parameters of HRV showed inhomogeneous data in a heterogeneous patient collective caused by unsystematic measurement of single parameters in various patient collectives. Innovative parameters of HRV are promising in patients with DCM and showed prognostic relevance although patient numbers are limited and prospective data are missing. Further studies are needed in this field. Despite the in part convincing evidence for the relevance of autonomic tone as a prognostic marker in patients with DCM, their evaluation is still not part of clinical routine. Additional parameters to estimate the risk of sudden cardiac death are urgently needed.

  6. The effect of pneumatic dilation in management of postfundoplication dysphagia.

    PubMed

    Sunjaya, D; Podboy, A; Blackmon, S H; Katzka, D; Halland, M

    2017-06-01

    Fundoplication surgery is a commonly performed procedure for gastro-esophageal reflux disease or hiatal hernia repair. Up to 10% of patients develop persistent postoperative dysphagia after surgery. Data on the effectiveness of pneumatic dilation for treatment are limited. The aim of this study was to evaluate clinical outcomes and identify clinical factors associated with successful response to pneumatic dilation among patients with persistent postfundoplication dysphagia (PPFD). We retrospectively evaluated patients who had undergone pneumatic dilation for PPFD between 1999 and 2016. Patients with dysphagia or achalasia prior to fundoplication were excluded. Demographic information, surgical history, severity of dysphagia, and clinical outcomes were collected. Data pertaining to esophagram, manometry, endoscopy, and pneumatic dilation were also collected. We identified 38 patients (82% female, 95% Caucasian, and median age 59 years) with PPFD who completed pneumatic dilation. The median postfundoplication dysphagia score was 2. Eleven patients had abnormal peristalsis on manometry. Seventeen patients reported response (seven complete) with an average decrease of 1 in their dysphagia score. Fifteen patients underwent reoperation due to PPFD. Hiatal hernia repair was the only factor that predicts a higher response rate to pneumatic dilation. Only one patient in our study developed complication (pneumoperitoneum) from pneumatic dilation. We found that pneumatic dilation to be a safe treatment option for PPFD with moderate efficacy. Patients who developed PPFD after a hiatal hernia repair may gain the greatest benefit after pneumatic dilation. We were not able to identify additional clinical, radiological, endoscopic, or manometric parameters that were predictive of response. © 2017 John Wiley & Sons Ltd.

  7. Dilated cardiomyopathy update: infectious-immune theory revisited.

    PubMed

    Kawai, Chuichi; Matsumori, Akira

    2013-11-01

    Dilated cardiomyopathy is characterized by dilatation of the left or right ventricle, or both ventricles. The degree of myocardial dysfunction is not attributable to abnormal loading conditions. The infectious-immune theory has long been hypothesized to explain the pathogenesis of many etiologically unrecognized dilated cardiomyopathies. Inflammations followed by immune reactions, which may be excessive, in the myocardium, evoked by external triggers such as viral infections and/or autoimmune antibodies, continue insidiously, and lead to the process of cardiac remodeling with ventricular dilatation and systolic dysfunction. This ultimately results in dilated cardiomyopathy. Hepatitis C virus-associated heart diseases are good examples of cardiac lesions definitely induced by viral infections in humans that progress to a chronic stage through complicated immune mechanisms. Therapeutic strategies for myocarditis and dilated cardiomyopathy have been obtained through analyses of the acute, subacute, and chronic phases of experimental viral myocarditis in mice. The appropriate modulation of excessive immune reactions during myocarditis, rather than their complete elimination, appears to be a key option in the prevention and treatment of dilated cardiomyopathy. The clinical application of an NF-κB decoy and immune adsorption of IgG3 cardiac autoantibodies have been used as immunomodulating therapies and may provide novel approaches for the treatment of refractory patients with dilated cardiomyopathy. Conventional therapeutic agents for chronic heart failure such as β-blockers, angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, and aldosterone antagonists in particular should be re-evaluated on the basis of their anti-inflammatory properties in the treatment of dilated cardiomyopathy.

  8. Dilatation of the Lower Cervical Esophagus in a Cow

    PubMed Central

    Kasari, T. R.

    1984-01-01

    Acquired megaesophagus of suspected neuromuscular origin was diagnosed in a six year old Holstein cow. The dilatation was restricted to the lower cervical esophagus. Signs included projectile regurgitation of chewed ingesta at variable periods of time after swallowing, nasal discharge of mucus and feed particles, and a cough. A secondary aspiration pneumonia was associated with this condition. The dilated portion of the esophagus was detected utilizing positive contrast radiography and fiberoptic endoscopy. Treatment consisted of feed management and antibiotics. Deglutition in the cow returned to normal over a three month period despite radiographic and fiberoptic endoscopic evidence of a persistent dilatation of the esophagus. ImagesFigure 1. PMID:17422388

  9. Efficacy of Pneumatic Dilatation in Saudi Achalasia Patients

    PubMed Central

    Aljebreen, Abdulrahman M.; Samarkandi, Sara; Al-Harbi, Tahani; Al-Radhi, Haifa; Almadi, Majid A

    2014-01-01

    Background/Aims: Pneumatic dilatation (PD) is one of the effective treatments of achalasia. The aim of this study was to evaluate the efficacy of pneumatic dilation and patient satisfaction in Saudi achalasia patients. Patients and Methods: We have retrospectively recruited patients with confirmed achalasia, who underwent at least one dilatation session from January 1990 to January 2010 at a single tertiary center. Symptoms, including weight loss, dysphagia, retrosternal pain, and regurgitation, were assessed with the use of the Eckardt score (which ranges from 0 to 12, with higher scores indicating more pronounced symptoms). All patients were called and asked about their Eckardt score in addition to their satisfaction score post the dilatation procedure. The primary outcome was therapeutic success (Eckardt score ≤ 3) and patient satisfaction at the time of their calls. The secondary outcomes included the need for retreatment and the rate of complications. Results: A total of 29 patients were included, with a mean age of 40.30 (95% CI: 36.1-44.6) and 55.2% of them were males. The mean of the pre-dilatation Eckardt score was 8.3 (95% CI: 7.2-9.4), which dropped to 2.59 (95% CI: 1.7-3.5) after PD (P < 0.01) with a clinical remission of 76.7% after the first dilatation and a total failure in two patients (7%) after the third dilatation. The mean number of dilatations was 1.3 (95% CI: 1.1-1.5) where 50.7% required one dilatation, 19.2% required two dilatations, and 30.1% required three dilatations. The mean of the symptoms-free period was 53.4 months (SD 52.7, range 1-180) with symptoms recurring in 35% of patients within 2 years. The mean of post-PD patient satisfaction was 7.45 (95% CI: 6.2-8.7). Perforation, which was treated conservatively, occurred in one patient (3.5%), whereas bleeding occurred in two patients (7%). Age or gender was not found to be a predictor of Eckardt score improvement on multivariate linear regression analysis. Conclusion: PD is an

  10. Statistical analysis with dilatation for development process of human fetuses.

    PubMed

    Naito, Kanta; Notsu, Akifumi; Udagawa, Jun; Otani, Hiroki

    2017-02-01

    This paper is concerned with the development process of human fetuses. Though the development process of human fetuses still includes many unknown issues, it is known that a certain harmonious relationship between the organs can be observed. This knowledge is based on our intuition, but we have no theory which clarifies these harmonized developments. The paper aims to give a mathematical understanding of the notion of harmonized development through the use of dilatation, which is a measure of the departure from conformal mapping. The asymptotics for dilatation have been developed using certain efficient models of quasiconformal mapping. The proposed method of dilatation is effectively applied to the human fetus data.

  11. Automated detection of dilated capillaries on optical coherence tomography angiography

    PubMed Central

    Dongye, Changlei; Zhang, Miao; Hwang, Thomas S.; Wang, Jie; Gao, Simon S.; Liu, Liang; Huang, David; Wilson, David J.; Jia, Yali

    2017-01-01

    Automated detection and grading of angiographic high-risk features in diabetic retinopathy can potentially enhance screening and clinical care. We have previously identified capillary dilation in angiograms of the deep plexus in optical coherence tomography angiography as a feature associated with severe diabetic retinopathy. In this study, we present an automated algorithm that uses hybrid contrast to distinguish angiograms with dilated capillaries from healthy controls and then applies saliency measurement to map the extent of the dilated capillary networks. The proposed algorithm agreed well with human grading. PMID:28271005

  12. Test of time dilation using stored Li+ ions as clocks at relativistic speed.

    PubMed

    Botermann, Benjamin; Bing, Dennis; Geppert, Christopher; Gwinner, Gerald; Hänsch, Theodor W; Huber, Gerhard; Karpuk, Sergei; Krieger, Andreas; Kühl, Thomas; Nörtershäuser, Wilfried; Novotny, Christian; Reinhardt, Sascha; Sánchez, Rodolfo; Schwalm, Dirk; Stöhlker, Thomas; Wolf, Andreas; Saathoff, Guido

    2014-09-19

    We present the concluding result from an Ives-Stilwell-type time dilation experiment using 7Li+ ions confined at a velocity of β=v/c=0.338 in the storage ring ESR at Darmstadt. A Λ-type three-level system within the hyperfine structure of the 7Li+3S1 →3P2 line is driven by two laser beams aligned parallel and antiparallel relative to the ion beam. The lasers' Doppler shifted frequencies required for resonance are measured with an accuracy of <4×10(-9) using optical-optical double resonance spectroscopy. This allows us to verify the special relativity relation between the time dilation factor γ and the velocity β, γ√1-β2=1 to within ±2.3×10(-9) at this velocity. The result, which is singled out by a high boost velocity β, is also interpreted within Lorentz invariance violating test theories.

  13. Shear-mediated dilation of the internal carotid artery occurs independent of hypercapnia.

    PubMed

    Hoiland, Ryan L; Smith, Kurt J; Carter, Howard H; Lewis, Nia C S; Tymko, Michael M; Wildfong, Kevin W; Bain, Anthony R; Green, Daniel J; Ainslie, Philip N

    2017-07-01

    Evidence for shear stress as a regulator of carotid artery dilation in response to increased arterial CO2 was recently demonstrated in humans during sustained elevations in CO2 (hypercapnia); however, the relative contributions of CO2 and shear stress to this response remains unclear. We examined the hypothesis that, after a 30-s transient increase in arterial CO2 tension and consequent increase in internal carotid artery shear stress, internal carotid artery diameter would increase, indicating shear-mediated dilation, in the absence of concurrent hypercapnia. In 27 healthy participants, partial pressures of end-tidal O2 and CO2, ventilation (pneumotachography), blood pressure (finger photoplethysmography), heart rate (electrocardiogram), internal carotid artery flow, diameter, and shear stress (high-resolution duplex ultrasound), and middle cerebral artery blood velocity (transcranial Doppler) were measured during 4-min steady-state and transient 30-s hypercapnic tests (both +9 mmHg CO2). Internal carotid artery dilation was lower in the transient compared with steady-state hypercapnia (3.3 ± 1.9 vs. 5.3 ± 2.9%, respectively, P < 0.03). Increases in internal carotid artery shear stress preceded increases in diameter in both transient (time: 16.8 ± 13.2 vs. 59.4 ± 60.3 s, P < 0.01) and steady-state (time: 18.2 ± 14.2 vs. 110.3 ± 79.6 s, P < 0.01) tests. Internal carotid artery dilation was positively correlated with shear rate area under the curve in the transient (r(2) = 0.44, P < 0.01) but not steady-state (r(2) = 0.02, P = 0.53) trial. Collectively, these results suggest that hypercapnia induces shear-mediated dilation of the internal carotid artery in humans. This study further promotes the application and development of hypercapnia as a clinical strategy for the assessment of cerebrovascular vasodilatory function and health in humans.NEW & NOTEWORTHY Shear stress dilates the internal carotid artery in humans. This vasodilatory response occurs independent

  14. Lorentz-violating dilatations in momentum space and some extensions on nonlinear actions of Lorentz-algebra-preserving systems

    SciTech Connect

    Bernardini, A. E.; Rocha, R. da

    2007-03-15

    We work on some general extensions of the formalism for theories which preserve the relativity of inertial frames with a nonlinear action of the Lorentz transformations on momentum space. Relativistic particle models invariant under the corresponding deformed symmetries are presented with particular emphasis on deformed dilatation transformations. The algebraic transformations relating the deformed symmetries with the usual (undeformed) ones are provided in order to preserve the Lorentz algebra. Two distinct cases are considered: a deformed dilatation transformation with a spacelike preferred direction and a very special relativity embedding with a lightlike preferred direction. In both analysis we consider the possibility of introducing quantum deformations of the corresponding symmetries such that the spacetime coordinates can be reconstructed and the particular form of the real space-momentum commutator remains covariant. Eventually feasible experiments, for which the nonlinear Lorentz dilatation effects here pointed out may be detectable, are suggested.

  15. Interaction of pepsin-[C16mim]Br system: interfacial dilational rheology and conformational studies.

    PubMed

    Huang, Tian; Cao, Chong; Liu, Zi-lin; Li, Yang; Du, Feng-pei

    2014-09-21

    The interfacial rheological property is closely related to the stabilities of foams and emulsions, yet there have been limited studies on the interaction between proteins with ionic liquid-type imidazolium surfactants at the decane-water interface as well as in the bulk. Herein, we investigated the interfacial and bulk properties of pepsin (PEP) and an ionic liquid (IL), 1-hexadecyl-3-methylimidazolium bromide, [C(16)mim]Br. The interfacial pressure and dilational rheology studies were performed to describe the formation of [C(16)mim]Br-pepsin complexes. The influence of the oscillating frequency and the bulk concentration of [C(16)mim]Br on the dilational properties were explored. The conformational changes were studied by monitoring the fluorescence and far UV-CD spectra. The results reveal that the globular structure of pepsin is one of the decisive factors controlling the nature of the interfacial film. The monotonous increase in the dilational elastic modulus of pepsin-[C(16)mim]Br solutions with the surface age indicates that no loops and tails had formed. Interestingly, with an increase in the concentration of [C(16)mim]Br, the εd-c curve first passes through a plateau value due to steric hindrance and the electrostatic barrier of already absorbed tenacious pepsin-[C(16)mim]Br complexes. With the further addition of [C(16)mim]Br, the remarkable decrease in dilational elastic modulus indicates that the compact structure is destroyed gradually. The results of the fluorescence spectra and far UV-CD spectra confirm that [C(16)mim]Br did not produce perceptible changes in pepsin at the concentrations studied in the dilational experiment. Possible schematic programs of the pepsin-[C(16)mim]Br interaction model at the interface and in bulk phase are proposed.

  16. The Impact of Auditory Spectral Resolution on Listening Effort Revealed by Pupil Dilation

    PubMed Central

    Winn, Matthew B.; Edwards, Jan R.; Litovsky, Ruth Y.

    2014-01-01

    Objectives This study measured the impact of auditory spectral resolution on listening effort. Systematic degradation in spectral resolution was hypothesized to elicit corresponding systematic increases in pupil dilation, consistent with the notion of pupil dilation as a marker of cognitive load. Design Spectral resolution of sentences was varied with 2 different vocoders: (1) a noise channel vocoder with a variable number of spectral channels; and (2) a vocoder designed to simulate front-end processing of a cochlear implant, including peak-picking channel selection with variable synthesis filter slopes to simulate spread of neural excitation. Pupil dilation was measured after subject-specific luminance adjustment and trial-specific baseline measures. Mixed-effects growth curve analysis was used to model pupillary responses over time. Results For both types of vocoder, pupil dilation grew with each successive degradation in spectral resolution. Within each condition, pupillary responses were not related to intelligibility scores, and the effect of spectral resolution on pupil dilation persisted even when only analyzing trials in which responses were 100% correct. Conclusions Intelligibility scores alone were not sufficient to quantify the effort required to understand speech with poor resolution. Degraded spectral resolution results in increased effort required to understand speech, even when intelligibility is at 100%. Pupillary responses were a sensitive and highly granular measurement to reveal changes in listening effort. Pupillary responses might potentially reveal the benefits of aural prostheses that are not captured by speech intelligibility performance alone, as well as the disadvantages that are overcome by increased listening effort. PMID:25654299

  17. Resveratrol Inhibits Aortic Root Dilatation in the Fbn1C1039G/+ Marfan Mouse Model.

    PubMed

    Hibender, Stijntje; Franken, Romy; van Roomen, Cindy; Ter Braake, Anique; van der Made, Ingeborg; Schermer, Edith E; Gunst, Quinn; van den Hoff, Maurice J; Lutgens, Esther; Pinto, Yigal M; Groenink, Maarten; Zwinderman, Aeilko H; Mulder, Barbara J M; de Vries, Carlie J M; de Waard, Vivian

    2016-08-01

    Marfan syndrome (MFS) is a connective tissue disorder caused by mutations in the fibrillin-1 gene. Patients with MFS are at risk of aortic aneurysm formation and dissection. Usually, blood pressure-lowering drugs are used to reduce aortic events; however, this is not sufficient for most patients. In the aorta of smooth muscle cell-specific sirtuin-1-deficient mice, spontaneous aneurysm formation and senescence are observed. Resveratrol is known to enhance sirtuin-1 activity and to reduce senescence, which prompted us to investigate the effectiveness of resveratrol in inhibition of aortic dilatation in the Fbn1(C1039G/+) MFS mouse model. Aortic senescence strongly correlates with aortic root dilatation rate in MFS mice. However, although resveratrol inhibits aortic dilatation, it only shows a trend toward reduced aortic senescence. Resveratrol enhances nuclear localization of sirtuin-1 in the vessel wall and, in contrast to losartan, does not affect leukocyte infiltration nor activation of SMAD2 and extracellular signal-regulated kinases 1/2 (ERK1/2). Interestingly, specific sirtuin-1 activation (SRT1720) or inhibition (sirtinol) in MFS mice does not affect aortic root dilatation rate, although senescence is changed. Resveratrol reduces aortic elastin breaks and decreases micro-RNA-29b expression coinciding with enhanced antiapoptotic Bcl-2 expression and decreased number of terminal apoptotic cells. In cultured smooth muscle cells, the resveratrol effect on micro-RNA-29b downregulation is endothelial cell and nuclear factor κB-dependent. Resveratrol inhibits aortic root dilatation in MFS mice by promoting elastin integrity and smooth muscle cell survival, involving downregulation of the aneurysm-related micro-RNA-29b in the aorta. On the basis of these data, resveratrol holds promise as a novel intervention strategy for patients with MFS. © 2016 The Authors.

  18. The time course of pupil dilation evoked by visual sexual stimuli: Exploring the underlying ANS mechanisms.

    PubMed

    Finke, Johannes B; Deuter, Christian E; Hengesch, Xenia; Schächinger, Hartmut

    2017-10-01

    The early processing of visual sexual stimuli shows signs of automaticity. Moreover, there is evidence for sex-specific patterns in cognitive and physiological responding to erotica. However, little is known about the time course of rapid pupillary responses to sexual stimuli and their correspondence with other measures of autonomic activity in women and men. To study pupil dilation as an implicit measure of sexual arousal at various stages of picture processing, we presented 35 heterosexual participants with pictures showing either erotic couples or single (male/female) erotic nudes, contrasted with people involved in everyday situations. Brightness-adjusted grayscale pictures were shown for a duration of 2,500 ms within the central visual field, alternating with perceptually matched patches. Left pupil diameter was recorded at 500 Hz using a video-based eye tracker. Skin conductance and heart rate were coregistered and correlated with latent components of pupil dilation (dissociated by temporal PCA). Whereas stimulus-evoked changes in pupil size indicated virtually no initial constriction, a rapid effect of appetence emerged (dilation to erotica within 500 ms). Responses at early stages of processing were remarkably consistent across both sexes. In contrast, later phases of pupil dilation, subjective ratings, and skin conductance responses showed a sex-specific pattern. Moreover, evidence for an association of early-onset pupil dilation and heart rate acceleration was found, suggestive of parasympathetic inhibition, whereas the late component was mainly related to sympathetically mediated skin conductance. Taken together, our results indicate that different temporal components of pupil responses to erotic stimuli may reflect divergent underlying neural mechanisms. © 2017 Society for Psychophysiological Research.

  19. Comparison of mortality rates and progression of left ventricular dysfunction in patients with idiopathic dilated cardiomyopathy and dilated versus nondilated right ventricular cavities.

    PubMed

    Sun, J P; James, K B; Yang, X S; Solankhi, N; Shah, M S; Arheart, K L; Thomas, J D; Stewart, W J

    1997-12-15

    This study assesses the influence of right ventricular (RV) dilation on the progression of left ventricular (LV) dysfunction and survival in patients with idiopathic dilated cardiomyopathy (IDC). Using transthoracic echocardiography, we studied 100 patients with IDC aged 20 to 80 years (mean 55 +/- 14); 67% were men. In the apical 4-chamber view, diastolic LV and RV chamber area measurements classified patients into 2 groups: group RV enlargement+ (RV area/LV area > 0.5) included 54 patients; group RV enlargement- (no RV enlargement) had RV area/LV area < or = 0.5. Echocardiographic studies were repeated in all patients after a mean of 33 +/- 16 months. At the time of the initial study, the 2 groups did not differ in age, gender, incidence of atrial fibrillation and diabetes, left ventricular mass, and LV ejection fraction, but the RV enlargement+ group had more severe tricuspid regurgitation and less LV enlargement. After 47 +/- 22 months (range 12 to 96), patients in group RV enlargement+ had lower LV ejection fraction (29% vs 34%, p = 0.006) than patients with initial RV enlargement-. At clinical follow-up, mortality was higher (43%) in patients with initial RV enlargement+ than the RV enlargement- patients (15%), p = 0.002. For survivors, the mitral deceleration time averaged 157 +/- 36 ms; for nonsurvivors or patients who required transplant, the mitral deceleration time averaged 97 +/- 12 ms (p < 0.0001). With use of a multivariate Cox model adjusting for LV ejection fraction, LV size, and age, the relative risk ratio of mortality from initial RV enlargement+ was 4.4 (95% confidence limits 1.7 to 11.1) (p = 0.002). Thus, patients with significant RV dilation had nearly triple the mortality over 4 years and more rapidly deteriorating LV function than patients with less initial RV dilation. In IDC, RV enlargement is a strong marker for adverse prognosis that may represent a different morphologic subset.

  20. Treatment of colonic anastomotic strictures with 'through the scope' balloon dilators.

    PubMed Central

    Dinneen, M D; Motson, R W

    1991-01-01

    Stricture occurs in 1.2-4.2% of colonic anastomoses. Symptomatic strictures have previously been treated by resection and re-anastomosis and more recently by radiographically guided dilatation by a modified Seldinger technique. This paper describes the endoscopic balloon dilatation of five symptomatic cases and three asymptomatic cases. Eight patients underwent balloon dilatation of colonic anastomotic strictures. Four patients had no symptoms post dilatation and the strictures remained patient on follow-up endoscopy. All the remaining patients required re-dilatation at approximately 2 months. One of these patients underwent dilatation but remained symptomatic, the dilatation was repeated and a colonic perforation occurred at this time. Of the other three, two continue to be followed up, and are well and one patient died of disseminated malignancy. Balloon dilatation with 'through the scope' dilators is a simpler technique than radiologically guided dilatation. These early results suggest that endoscopic dilatation may avoid further surgery in some patients with anastomotic stricture. PMID:2041001

  1. Osmotic self-expanding dilation technology for treatment of sinusitis: the Vent-Os sinus dilation system.

    PubMed

    Catalano, Peter; Hester, Jerome; Mandrusov, Evgenia

    2015-01-01

    The Vent-Os Sinus Dilation System is an osmotically driven device that provides a means to access the sinus space and to dilate the maxillary sinus ostia and associated spaces in adults for diagnostic and therapeutic procedures. Unlike balloon dilation devices that use rapid, high-pressure inflation, this self-expanding device is designed to gently and gradually open the maxillary ostia. The procedure can be safely and easily completed in-office with minimal anesthetics and analgesics on board. Clinical results support excellent patency and safety outcomes with the use of this product in patients with chronic rhinosinusitis.

  2. Relationship between flow-mediated vasodilation and cardiovascular risk factors in a large community-based study

    PubMed Central

    Maruhashi, Tatsuya; Soga, Junko; Fujimura, Noritaka; Idei, Naomi; Mikami, Shinsuke; Iwamoto, Yumiko; Kajikawa, Masato; Matsumoto, Takeshi; Hidaka, Takayuki; Kihara, Yasuki; Chayama, Kazuaki; Noma, Kensuke; Nakashima, Ayumu; Goto, Chikara; Tomiyama, Hirofumi; Takase, Bonpei; Yamashina, Akira; Higashi, Yukihito

    2013-01-01

    Objective To determine the relationships between flow-mediated vasodilation (FMD) and cardiovascular risk factors, and to evaluate confounding factors for measurement of FMD in a large general population in Japan. Methods This was a cross-sectional study. A total of 5314 Japanese adults recruited from people who underwent health screening from 1 April 2010 to 31 August 2012 at 3 general hospitals in Japan. Patients’ risk factors (age, Body Mass Index, blood pressure, cholesterol parameters, glucose level and HbA1c level) and prevalence of cardiovascular disease (coronary heart disease and cerebrovascular disease) were investigated. Results Univariate regression analysis revealed that FMD correlated with age (r=−0.27, p<0.001), Body Mass Index (r=−0.14, p<0.001), systolic blood pressure (r=−0.18, p<0.001), diastolic blood pressure (r=−0.13, p<0.001), total cholesterol (r=−0.07, p<0.001), triglycerides (r=−0.10, p<0.001), high-density lipoprotein cholesterol (r=0.06, p<0.001), low-density lipoprotein cholesterol (r=−0.04, p=0.01), glucose level (r=−0.14, p<0.001), HbA1c (r=−0.14, p<0.001), and baseline brachial artery diameter (r=−0.43, p<0.001) as well as Framingham Risk score (r=−0.29, p<0.001). Multivariate analysis revealed that age (t value=−9.17, p<0.001), sex (t value=9.29, p<0.001), Body Mass Index (t value=4.27, p<0.001), systolic blood pressure (t value=−2.86, p=0.004), diabetes mellitus (t value=−4.19, p<0.001), smoking (t value=−2.56, p=0.01), and baseline brachial artery diameter (t value=−29.4, p<0.001) were independent predictors of FMD. Conclusions FMD may be a marker of the grade of atherosclerosis and may be used as a surrogate marker of cardiovascular outcomes. Age, sex, Body Mass Index, systolic blood pressure, diabetes mellitus, smoking and, particularly, baseline brachial artery diameter are potential confounding factors in the measurement of FMD. PMID:24153417

  3. In vivo vascular wall tissue characterization using a strain tensor measuring (STM) technique for flow-mediated vasodilation analyses.

    PubMed

    Mahmoud, Ahmed M; Frisbee, Jefferson C; D'Audiffret, Alexandre; Mukdadi, Osama M

    2009-10-21

    Endothelial dysfunction is considered to be a key factor in the development of atherosclerosis, and the measurement of flow-mediated vasodilation (FMD) in brachial and other conduit arteries has become a common method to assess the status of endothelial function in vivo. Based on the direct relationship between the FMD response and local shear stress on the conduit brachial artery endothelium, we hypothesize that measuring relevant changes in the brachial wall strain tensor would provide a non-invasive tool for assessing vascular mechanics during post-occlusion reactive hyperemia. Direct measurement of the wall strain tensor due to FMD has not yet been reported in the literature. In this work, a noninvasive direct ultrasound-based strain tensor measuring (STM) technique is presented to assess changes in the mechanical parameters of the vascular wall during post-occlusion reactive hyperemia and/or FMD, including local velocities and displacements, diameter change, local strain tensor and strain rates. The STM technique utilizes sequences of B-mode ultrasound images as its input with no extra hardware requirement, and its algorithm starts with segmenting a region of interest within the artery and providing the acquisition parameters. Then a block matching technique based on speckle tracking is employed to measure the frame-to-frame local velocities. Displacements, diameter change, local strain tensor and strain rates are then calculated by integrating or differentiating velocity components. The accuracy of the STM algorithm was assessed in vitro using phantom studies, where an average error of 7% was reported using different displacement ranging from 100 microm to 1000 microm. Furthermore, in vivo studies using human subjects were performed to test the STM algorithm during pre- and post-occlusion. Good correlations (|r| >0.5, P < 0.05) were found between the post-occlusion responses of diameter change and local wall strains. Results indicate the validity and

  4. In vivo vascular wall tissue characterization using a strain tensor measuring (STM) technique for flow-mediated vasodilation analyses

    NASA Astrophysics Data System (ADS)

    Mahmoud, Ahmed M.; Frisbee, Jefferson C.; D'Audiffret, Alexandre; Mukdadi, Osama M.

    2009-10-01

    Endothelial dysfunction is considered to be a key factor in the development of atherosclerosis, and the measurement of flow-mediated vasodilation (FMD) in brachial and other conduit arteries has become a common method to assess the status of endothelial function in vivo. Based on the direct relationship between the FMD response and local shear stress on the conduit brachial artery endothelium, we hypothesize that measuring relevant changes in the brachial wall strain tensor would provide a non-invasive tool for assessing vascular mechanics during post-occlusion reactive hyperemia. Direct measurement of the wall strain tensor due to FMD has not yet been reported in the literature. In this work, a noninvasive direct ultrasound-based strain tensor measuring (STM) technique is presented to assess changes in the mechanical parameters of the vascular wall during post-occlusion reactive hyperemia and/or FMD, including local velocities and displacements, diameter change, local strain tensor and strain rates. The STM technique utilizes sequences of B-mode ultrasound images as its input with no extra hardware requirement, and its algorithm starts with segmenting a region of interest within the artery and providing the acquisition parameters. Then a block matching technique based on speckle tracking is employed to measure the frame-to-frame local velocities. Displacements, diameter change, local strain tensor and strain rates are then calculated by integrating or differentiating velocity components. The accuracy of the STM algorithm was assessed in vitro using phantom studies, where an average error of 7% was reported using different displacement ranging from 100 µm to 1000 µm. Furthermore, in vivo studies using human subjects were performed to test the STM algorithm during pre- and post-occlusion. Good correlations (|r| >0.5, P < 0.05) were found between the post-occlusion responses of diameter change and local wall strains. Results indicate the validity and versatility of

  5. Treatment of microperforate hymen with serial dilation: a novel approach.

    PubMed

    Segal, Thalia R; Fried, Wendy B; Krim, Eileen Y; Parikh, Deep; Rosenfeld, David L

    2015-04-01

    Microperforate and imperforate hymens are one of the most common causes of vaginal outflow obstruction in the adolescent population. To date, these hymen anomalies are traditionally treated by hymenectomy with a cruciate excision. We report 2 cases of adolescent women with a microperforate hymen who were successfully and minimally invasively treated with progressive dilation with Hegar cervical dilators until a number 23 dilator was reached under anesthesia in the OR. Minimally invasive treatment of microperforate hymen with the use of progressive cervical dilators may be an alternative technique to the traditional excisional hymenectomy. Our patients reported satisfaction and minimal postoperative pain or scarring at 2 weeks and 6 months after the procedure. This technique can be an additional option for all women, especially those with cultural beliefs in virginity. Copyright © 2015 North American Society for Pediatric and Adolescent Gynecology. Published by Elsevier Inc. All rights reserved.

  6. Dilated hearts at high altitude: words from on high.

    PubMed

    Lankford, Harvey V; Swenson, Erik R

    2014-12-01

    From the time of the turn of the twentieth century, dilated hearts and presumed cardiac fatigue in expeditionary climbers and scientists have been the subject of much commentary in the medical and mountaineering literature. Although largely attributed by most, but not all, to left heart strain, the description of dilated hearts in these accounts is clearly that of right heart dilation as a consequence of high and sustained hypoxic pulmonary vasoconstriction with hypertensive remodeling. This essay will feature quotations from the writings of high altitude pioneers about dilated, strained, or enlarged hearts. It will give some brief physiology of the right side of the heart as background, but will focus on the words of mountaineers and mountaineering physicians as color commentary.

  7. Perceptual and not physical eye contact elicits pupillary dilation.

    PubMed

    Honma, Motoyasu; Tanaka, Yasuto; Osada, Yoshihisa; Kuriyama, Kenichi

    2012-01-01

    Eye contact is important to share communication during social interactions. However, how accurately humans can perceive the gaze direction of others toward themselves and whether pupils dilate when humans consciously or unconsciously perceive own eyes are looked by others remain unclear. In this study, we examined the relationship between the explicit perception of looking into each other's eyes and the implicit physiological response of pupillary dilation by using an original face-to-face method. We found that humans do not correctly detect the gaze direction of others. Furthermore, one's pupils dilated when one gazed at others' eyes. Awareness of others' gaze on one's eyes, rather than the actual focusing of other's gaze on one's eyes, enhanced pupillary dilation. Therefore, physiological responses are caused not when people actually look into each other's gaze, but when the consciousness of other's gaze is activated, which suggests that eye contact often involves one-way communication.

  8. Human eyes with dilated pupils induce pupillary contagion in infants.

    PubMed

    Fawcett, Christine; Arslan, Melda; Falck-Ytter, Terje; Roeyers, Herbert; Gredebäck, Gustaf

    2017-08-29

    Being sensitive and responsive to others' internal states is critical for social life. One reliable cue to what others might be feeling is pupil dilation because it is linked to increases in arousal. When adults view an individual with dilated pupils, their pupils dilate in response, suggesting not only sensitivity to pupil size, but a corresponding response as well. However, little is known about the origins or mechanism underlying this phenomenon of pupillary contagion. Here we show that 4- to 6-month-old infants show pupillary contagion when viewing photographs of eyes with varying pupil sizes: their pupils dilate in response to others' large, but not small or medium pupils. The results suggest that pupillary contagion is likely driven by a transfer of arousal and that it is present very early in life in human infants, supporting the view that it could be an adaptation fundamental for social and emotional development.

  9. Dilated cardiomyopathy: a preventable presentation of DiGeorge Syndrome.

    PubMed

    Jamieson, A; Smith, C J

    2015-01-01

    Patients with cardiac failure require careful evaluation to determine the precise nature of the cause of their illness. Genetic causes of dilated cardiomyopathy are well known but inherited conditions may lead to unexpected consequences through intermediate mechanisms not readily recognised as a feature of the inherited disorder. We describe a case of dilated cardiomyopathy resulting from prolonged hypocalcaemia due to previously undiagnosed hypoparathyroidism resulting from DiGeorge Syndrome and describe the features of this case and the treatment of hypoparathyroidism.

  10. Clinical and echocardiographic determinants in bicuspid aortic dilatation

    PubMed Central

    Peeters, Frederique E.C.M.; Van der Linden, Noreen; Thomassen, Alissa L.L.; Crijns, Harry J.G.M.; Meex, Steven J.R.; Kietselaer, Bas L.J.H.

    2016-01-01

    Abstract Bicuspid aortic valve (BAV) disease is associated with aortic dilatation. Timing of follow-up and surgery is challenging. Hence, there is an unmet clinical need for additional risk stratification. It is unclear whether valve morphology is associated with dilatation rates. Therefore, the objective of this study was to examine the association between clinical and echocardiographic determinants (including valve morphology) and aortic dimension and the progression rate of dilatation. Aortic dimensions were assessed on serial echocardiographic images between 1999 and 2014 in a population of 392 patients with BAVs in a tertiary care center in the Netherlands. Analyses using mixed linear models were performed. Mean age of participants was 48 ± 17 years and 69% were male. BAV morphology was associated with aortic dimensions, as well as age, sex, BSA, and valvular dysfunction. Tubular ascending aorta, sinus of Valsalva, and sinotubular junction showed a dilatation rate of 0.32, 0.18, and 0.06 mm/year, respectively. Dilatation rate was not associated with valve morphology. In the present study, there is no association between BAV morphology and aortic dilatation rates. Therefore, morphology is of limited use in prediction of aortic growth. Discovering fast progressors remains challenging. PMID:28033264

  11. Clusters, deformation, and dilation: Diagnostics for material accumulation regions

    NASA Astrophysics Data System (ADS)

    Huntley, Helga S.; Lipphardt, B. L.; Jacobs, Gregg; Kirwan, A. D.

    2015-10-01

    Clusters of material at the ocean surface have been frequently observed. Such accumulations of material play an important role in a variety of applications, from biology to pollution mitigation. Identifying where clusters will form can aid in locating, for example, hotspots of biological activity or regions of high pollutant concentration. Here cluster strength is introduced as a new metric for defining clusters when all particle positions are known. To diagnose regions likely to contain clusters without the need to integrate millions of particle trajectories, we propose to use dilation, which quantifies area changes of Lagrangian patches. Material deformation is decomposed into dilation and area-preserving stretch processes to refine previous approaches based on finite-time Lyapunov exponents (FTLE) by splitting the FTLE into fundamental kinematic properties. The concepts are developed theoretically and illustrated in the context of a state-of-the-art data-assimilating predictive ocean model of the Gulf of Mexico. Regions of dilation less than one are shown to be much more likely (6 times more likely in the given example) to be visited by particles than those of dilation greater than one. While the relationship is nonlinear, dilation and cluster strength exhibit a fairly good correlation. In contrast, both stretch and Eulerian divergence are found to be uncorrelated with cluster strength. Thus, dilation maps can be used as guides for identifying cluster locations, while saving some of the computational cost of trajectory integrations.

  12. Clinical implications of anti-cardiac immunity in dilated cardiomyopathy.

    PubMed

    Caforio, A L P; Mahon, N G; McKenna, W J

    2006-01-01

    Criteria of organ-specific autoimmunity are fulfilled in a subset of patients with myocarditis/dilated cardiomyopathy (DCM). In particular, circulating heart-reactive autoantibodies are found in such patients and symptom-free relatives. These autoantibodies are directed against multiple antigens, some of which are expressed in the heart (organ-specific), others in heart and some skeletal muscle fibres (partially heart-specific) or in heart and skeletal muscle (muscle-specific). Distinct autoantibodies have different frequency in disease and normal controls. Different techniques detect one or more antibodies, thus they cannot be used interchangeably for screening. It is unknown whether the same patients produce more antibodies or different patient groups develop autoimmunity to distinct antigens. IgG antibodies, shown to be cardiac- and disease-specific for myocarditis/DCM, can be used as autoimmune markers for relatives at risk as well as for identifying patients in whom immunosuppression may be beneficial. Some autoantibodies may also have a functional role, but further work is needed.

  13. Spectral dilation of L(B,H)-valued measures and its application to stationary dilation for Banach space valued processes

    NASA Technical Reports Server (NTRS)

    Miamee, A. G.

    1989-01-01

    Let B be a Banach space and H and K to Hilbert spaces. The spectral dilation of L(B,H)-valued measures is studied and it is shown that the recent results of Makagon and Salehi (1986) and Rosenberg (1982) on the dilation of L(K,H)-valued measures can be extended to hold for the general Banach space setting of L(B,H)-valued measures. These L(B,H)-valued measures are closely connected to the Banach space valued processes. This connection is recalled and as application of spectral dilation of L(B,H)-valued measures the well known stationary dilation results for scalar valued processes is extended to the case of Banach space valued processes.

  14. Spectral dilation of L(B,H)-valued measures and its application to stationary dilation for Banach space valued processes

    NASA Technical Reports Server (NTRS)

    Miamee, A. G.

    1988-01-01

    Let B be a Banach space and H and K two Hilbert spaces. The spectral dilation of L(B,H)-valued measures is studied and it is shown that the recent results of Makagon and Salehi (1986) and Rosenberg (1982) on the dilation of L(K,H)-valued measures can be extended to hold for the general Banach space setting of L(B,H)-valued measures. These L(B,H)-valued measures are closely connected to the Banach space valued processes. This connection is recalled and as application of spectral dilation of L(B,H)-valued measures the well known stationary dilation results for scalar valued processes is extended to the case of Banach space valued processes.

  15. Electrical storm in dilated cardiomyopathy treated using epicardial radiofrequency ablation as a first line therapy.

    PubMed

    Faustino, Massimiliano; Agricola, Tullio; Xyheri, Borejda; Di Girolamo, Enrico; Leonzio, Luigi; Pizzi, Carmine

    2016-09-01

    We report a patient with non-ischemic dilated cardiomyopathy and low left ventricular systolic function (28%) presenting with an electrical storm originated in epicardial scar and ablated by radiofrequency. This case report suggests that a strategy of epicardial catheter ablation is reasonable for the patient presenting with electrical storm related to structural disease with a low left ventricular ejection fraction. Copyright © 2016 Cardiological Society of India. Published by Elsevier B.V. All rights reserved.

  16. Outcomes of esophageal dilation in eosinophilic esophagitis: Safety, efficacy, and persistence of the fibrostenotic phenotype

    PubMed Central

    Runge, Thomas M.; Eluri, Swathi; Cotton, Cary; Burk, Caitlin M.; Woosley, John T.; Shaheen, Nicholas J.; Dellon, Evan S.

    2016-01-01

    Objectives Esophageal dilation is commonly performed in eosinophilic esophagitis (EoE), but there are few long-term data. The aims of this study were to assess the safety and long-term efficacy of esophageal dilation in a large cohort of EoE cases and determine the frequency and predictors of requiring multiple dilations. Methods We conducted a retrospective cohort study in the University of North Carolina EoE clinicopathological database from 2002-2014. Included subjects met consensus diagnostic criteria for EoE. Clinical, endoscopic, and histologic features were extracted, as were dilation characteristics (dilator type, change in esophageal caliber, total number of dilations) and complications. Patients with EoE who had undergone dilation were compared to those who did not and also stratified by whether they required single or multiple dilations. Results Of 509 EoE patients, 164 were dilated a total of 486 times. Those who underwent dilation had a longer duration of symptoms prior to diagnosis (11.1 vs. 5.4 yrs, p<0.001). 95 patients (58%) required >1 dilation (417 dilations total, mean of 4.4 ± 4.3 per patient). The only predictor of requiring multiple dilations was a smaller baseline esophageal diameter. Dilation was tolerated well, with no major bleeds, perforations, or deaths. The overall complication rate was 5%, primarily due to post-procedural pain. Of 164 individuals dilated, a majority (58%, or 95/164) required a second dilation. Of these individuals, 75% required dilation within 1 year. Conclusions Dilation in EoE is well-tolerated, with a very low risk of serious complications. Patients with long-standing symptoms prior to diagnosis are likely to require dilation. More than half of those dilated will require multiple dilations, often needing a second procedure within one year. These findings can be used to counsel patients with fibrostenotic complications of EoE. PMID:26753894

  17. Dilation Behavior of Thermal Spray Coatings

    NASA Astrophysics Data System (ADS)

    Bejarano Lopez, Miryan Lorena

    Thermal Spray (TS) is a very versatile manufacturing process to deposit thick coatings on a variety of substrates. Coatings are used in protective (i.e. wear, chemical attack, high temperature, etc.) and functional (i.e. sensors) applications. TS coatings have a unique lamellar microstructure as a result of the overlapping of millions of molten and partially-molten particles. During processing, high deformation by impact, high temperature, and rapid solidification lead to a complex hierarchical material system that contains a high amount of microstructural defects. The presence of defects in the microstructure contribute to differences in property values in comparison to bulk materials. Thermal stresses and residual strains arise from processing, thermal gradients and thermal exposure. Evaluation of thermal properties, in this case, the coefficient of thermal expansion (CTE) is of vital importance to enhance coating performance. In this dissertation, expansion measurements of various metals, alloys, ceramics, and cermet coatings; were carried out using various techniques (push rod dilatometry, x-ray diffraction XRD, digital image correlation DIC, and curvature method) to determine the dilation behavior at the atomic, micro- and macro-scale levels. The main results were. 1) Mathematical models (Turner and Kerner) used for composite materials, successfully predicted the CTE property of a TS coating where the primary phase is the coating material and the secondary phases can be oxides, precipitates, etc. (formed as a byproduct of the spraying process). CTE was found not to be affected by porosity. 2) Despite the anisotropic behavior characteristic of TS coatings, the experimental results shown that CTE results to be reasonable isotropic within the scope of this study. 3) The curvature method was found to be an alternative technique to obtain the CTE, as well as the Young's modulus of coating in a bi-material strip, with good approximation. 4) An anomalous expansion

  18. Two-Phase Solid/Fluid Simulation of Dense Granular Flows With Dilatancy Effects

    NASA Astrophysics Data System (ADS)

    Mangeney, Anne; Bouchut, Francois; Fernandez-Nieto, Enrique; Narbona-Reina, Gladys; Kone, El Hadj

    2017-04-01

    Describing grain/fluid interaction in debris flows models is still an open and challenging issue with key impact on hazard assessment [1]. We present here a two-phase two-thin-layer model for fluidized debris flows that takes into account dilatancy effects. It describes the velocity of both the solid and the fluid phases, the compression/ dilatation of the granular media and its interaction with the pore fluid pressure [2]. The model is derived from a 3D two-phase model proposed by Jackson [3] and the mixture equations are closed by a weak compressibility relation. This relation implies that the occurrence of dilation or contraction of the granular material in the model depends on whether the solid volume fraction is respectively higher or lower than a critical value. When dilation occurs, the fluid is sucked into the granular material, the pore pressure decreases and the friction force on the granular phase increases. On the contrary, in the case of contraction, the fluid is expelled from the mixture, the pore pressure increases and the friction force diminishes. To account for this transfer of fluid into and out of the mixture, a two-layer model is proposed with a fluid or a solid layer on top of the two-phase mixture layer. Mass and momentum conservation are satisfied for the two phases, and mass and momentum are transferred between the two layers. A thin-layer approximation is used to derive average equations. Special attention is paid to the drag friction terms that are responsible for the transfer of momentum between the two phases and for the appearance of an excess pore pressure with respect to the hydrostatic pressure. Interestingly, when removing the role of water, our model reduces to a dry granular flow model including dilatancy. We first compare experimental and numerical results of dilatant dry granular flows. Then, by quantitatively comparing the results of simulation and laboratory experiments on submerged granular flows, we show that our model

  19. For biliary dilatation, a negative endosonography needs additional image studies in weight loss suggesting malignancy.

    PubMed

    Chen, Chien-Hua; Yang, Chi-Chieh; Yeh, Yung-Hsiang

    2013-08-01

    Biliary dilatation frequently raises concerns about the possibility of pancreatobiliary diseases. This study assessed the etiologic yield of endosonography (EUS) in this situation. A retrospective review was completed with 163 consecutive patients who had undergone EUS for a dilated common bile duct (CBD) without definite pathology on ultrasonography. Binary logistic regression analysis disclosed that malignancy was positively related to weight loss and was inversely related to abdominal pain; nevertheless, choledocholithiasis was positively related to fever and elevated carbohydrate antigen 19-9 (p < 0.05). The accuracy of EUS was 95.1 % (155/163) for overall cause of biliary dilatation, 100 % (73/73) for no pathological finding, 96.3 % (26/27) for ampullary cancer, 84.6 % (11/13) for pancreatic cancer, 40.0 % (2/5) for CBD cancer, and 92.6 % (25/27) for choledocholithiasis, respectively. The accuracy of EUS decreased in the presence of malignancy (86.7 %, 39/45 vs. 98.3 %, 116/118, p = 0.006). EUS missed three CBD cancers, two pancreatic cancers, and one ampullary cancer; however, the diagnosis was rescued by computed tomography in two pancreatic cancers and one CBD cancer. EUS is accurate in patients with fever suggestive of choledocholithiasis. However, a negative EUS finding should call for additional image studies in patients with weight loss suggestive of malignancy.

  20. Complications of percutaneous transhepatic biliary drainage in patients with dilated and nondilated intrahepatic bile ducts.

    PubMed

    Weber, Andreas; Gaa, Jochen; Rosca, Bogdan; Born, Peter; Neu, Bruno; Schmid, Roland M; Prinz, Christian

    2009-12-01

    Percutaneous transhepatic biliary drainage (PTBD) have been described as an effective technique to obtain biliary access. Between January 1996 and December 2006, a total of 419 consecutive patients with endoscopically inaccessible bile ducts underwent PTBD. The current retrospective study evaluated success and complication rates of this invasive technique. PTBD was successful in 410/419 patients (97%). The success rate was equal in patients with dilated and nondilated bile ducts (p=0.820). In 39/419 patients (9%) procedure related complications could be observed. Major complications occurred in 17/419 patients (4%). Patients with nondilated intrahepatic bile ducts had significantly higher complication rates compared to patients with dilated intrahepatic bile ducts (14.5% vs. 6.9%, respectively [p=0.022]). Procedure related deaths were observed in 3 patients (0.7%). In conclusion, percutaneous transhepatic biliary drainage is an effective procedure in patients with dilated and nondilated intrahepatic bile ducts. However, patients with nondilated intrahepatic bile ducts showed a higher risk for procedure related complications.

  1. Percutaneous Placement of Metallic Stents in Malignant Biliary Obstruction: One-Stage or Two-Stage Procedure? Pre-Dilate or Not?

    SciTech Connect

    Inal, Mehmet; Aksungur, Erol; Akguel, Erol; Oguz, Mahmut; Seydaoglu, Guelsah

    2003-02-15

    The aim of this paper was to evaluate the necessity of percutaneous transhepatic catheter drainage and balloon dilation procedures performed before stent insertion. One hundred and twenty-six patients with unresectable malignant biliary obstruction underwent palliative therapy by means of percutaneous transhepatic placement of 183 metallic biliary endoprotheses. Forty-four (35%) patients underwent metallic stent insertion in a one-stage procedure and 82(65%) had undergone percutaneous transhepatic catheter drainage before stent insertion. Balloon dilation of the stenosis before stent placement (pre-dilation) was performed in 53 (42%) of 126 patients. The rate of the 30-day mortality was 11%, with no procedure-related deaths. The total rate of early complications was 29%, and 84% of these complications were due to percutaneous transhepatic catheter drainage and pre-dilation procedures. Percutaneous transhepatic catheter drainage and pre-dilation had no clinical or statistically significant effect on the patients' survival and stent patency rate. Percutaneous transhepatic catheter drainage and balloon dilation increased the cost of stent placement 18% and 19%, respectively. Palliation of malignant biliary obstruction with percutaneous transhepatic stent insertion should be done directly, in the simplest way, without performing percutaneous transhepatic catheter drainage and balloon dilation before stent placement. It is more useful, safe, and cost-effective.

  2. Endoluminal dilatation for embedded hemodialysis catheters: A case-control study of factors associated with embedding and clinical outcomes

    PubMed Central

    Talreja, Hari; Ryan, Stephen Edward; Graham, Janet; Sood, Manish M.; Hadziomerovic, Adnan; Clark, Edward

    2017-01-01

    Background With the increasing frequency of tunneled hemodialysis catheter use there is a parallel increase in the need for removal and/or exchange. A small but significant minority of catheters become embedded or ‘stuck’ and cannot be removed by traditional means. Management of embedded catheters involves cutting the catheter, burying the retained fragment with a subsequent increased risk of infections and thrombosis. Endoluminal dilatation may provide a potential safe and effective technique for removing embedded catheters, however, to date, there is a paucity of data. Objectives 1) To determine factors associated with catheters becoming embedded and 2) to determine outcomes associated with endoluminal dilatation Methods All patients with endoluminal dilatation for embedded catheters at our institution since Jan. 2010 were included. Patients who had an embedded catheter were matched 1:3 with patients with uncomplicated catheter removal. Baseline patient and catheter characteristics were compared. Outcomes included procedural success and procedure-related infection. Logistic regression models were used to determine factors associated with embedded catheters. Results We matched 15 cases of embedded tunneled catheters with 45 controls. Among patients with embedded catheters, there were no complications with endoluminal dilatation. Factors independently associated with embedded catheters included catheter dwell time (> 2 years) and history of central venous stenosis. Conclusion Embedded catheters can be successfully managed by endoluminal dilatation with minimal complications and factors associated with embedding include dwell times > 2 years and/or with a history of central venous stenosis. PMID:28346468

  3. Novel short-duration heating balloon dilatation with uniform temperature distribution: the heating conditions to suppress neo-intimal hyperplasia.

    PubMed

    Kunio, M; Shimazaki, N; Arai, T; Sakurada, M

    2011-01-01

    We investigate the relation between the influences on smooth muscle cells and the chronic performances of our novel short-duration heating balloon dilatation to reveal the heating conditions which can suppress the neo-intimal hyperplasia after our heating dilatations. The temperature of prototype balloon catheter surface was measured during short-duration heating balloon dilatation ex vivo. There existed 2 °C temperature variations in the long direction of prototype balloon catheter at a maximum. The neo-intimal hyperplasia occupancy rate after our short-duration heating dilatations were measured in vivo porcine study. The neo-intimal hyperplasia was suppressed most at 75 °C in balloon peak temperature in vivo. The estimated dead rate of smooth muscle cells at this condition was about 13% by the Arrhenius equation. We think that the suppression of neo-intimal hyperplasia was obtained after our short-duration heating dilatation due to the proper decrease of smooth muscle cells by heating and no thermal damages to the adventitia and surrounding tissues.

  4. Transhepatic Balloon Dilatation of Early Biliary Strictures in Pediatric Liver Transplantation: Successful Initial and Mid-Term Outcome

    SciTech Connect

    Belenky, Alexander; Mor, Eytan; Bartal, Gabriel; Atar, Eli; Shapiro, Riki; Bar-Nathan, Nathan; Bachar, Gil N.

    2004-09-15

    Purpose: To evaluate the initial and mid-term outcomes of transhepatic balloon dilatation for the treatment of early biliary strictures in lateral left-segment liver transplants in young children.Methods: Between April 1997 and May 2001, seven children aged 9 months to 6 years with nine benign strictures in left-segment liver grafts were treated percutaneously. Sessions of two or three dilations were performed three or four times at average intervals of 10-20 days. In each session, the biliary stenoses were gradually dilated using balloons of 3-7 mm. Follow-up ranged from 12 to 54 months (mean 27 months, median 12 months). Clinical success was defined as resolution of the stenosis, normalization of liver enzymes and lack of clinical symptoms. Results: Technical success was achieved in all nine strictures. Hemobilia occurred in one patient and was successfully treated. On follow-up, all patients had complete clinical recovery with normalization of liver function and imaging of patent bile ducts. Conclusion: Balloon dilatation is an effective and relatively safe method for the treatment of early biliary strictures in left-segment liver transplantation in young children. We recommend this approach as the initial treatment for early strictures. Metal stents or surgery should be reserved for patients with late appearance of strictures or failure of balloon dilatation.

  5. Treatment of Ureterointestinal Anastomotic Strictures by Diathermal or Cryoplastic Dilatation

    SciTech Connect

    Orsi, Franco; Penco, Silvia Matei, Victor; Bonomo, Guido; Vigna, Paolo Della; Monfardini, Lorenzo; Cobelli, Ottavio De

    2007-09-15

    Background. Ureterointestinal anastomotic strictures (UAS) complicate 10-15% of surgeries for urinary diversion and are the main cause of deterioration in renal function. Treatments are surgical revision, management with autostatic stent, balloon dilatation, endoscopic incision, and percutaneous transrenal diathermy (Acucise). A new option is cryoplastic dilatation (Polar-Cath). Purpose. To assess the feasibility, complications, and preliminary results of UAS treatment using the Acucise and Polar-Cath systems. Methods. Nineteen UAS, diagnosed by ultrasonography or computed tomography and sequential renal scintigraphy, occurred in 15 cancer patients after radical cystectomy and urinary diversion. Fifteen were managed with balloon diathermy and 4 by balloon cryoplasty in a three-stage procedure-percutaneous nephrostomy, diathermal or cryoplastic dilatation, and transnephrostomic control with nephrostomy removal-each separated by 15 days. All patients gave written informed consent. Results. Dilatations were successful in all cases. The procedure is simple and rapid (about 45 min) under fluoroscopic control and sedation. Procedural complications occurred in 1 (5%) patient with UAS after Wallace II uretero-ileocutaneostomy: a common iliac artery lesion was induced by diathermal dilatation, evident subsequently, and required surgical repair. Patency with balloon diathermy was good, with two restenoses developing over 12 months (range 1-22) of follow-up. With balloon cryoplastic dilatation, one restenosis developed in the short term; follow-up is too brief to assess the long-term efficacy. Conclusion. Our short-term results with diathermal and cryoplastic dilatation to resolve UAS are good. If supported by longer follow-up, the techniques may be considered as first-choice approaches to UAS. Surgery should be reserved for cases in which this minimally invasive technique fails.

  6. [Pneumatic dilatation of achalasia: local experience in treating 41 patients].

    PubMed

    Honein, Khalil; Slim, Rita; Yaghi, César; Kheir, Bahaa; Bou Jaoudé, Joseph; Sayegh, Raymond

    2007-01-01

    L'achalasia is the best known primary motor disorder of the esophagus in which the lower esophageal sphincter (LES) has abnormally high resting pressure and incomplete relaxation with swallowing. Pneumatic dilatation (PD) remains the first choice of treatment. Our aim was to report, in a retrospective way, our experience in treating with pneumatic dilatation 41 achalasia patients admitted to the gastroenterology unit at Hôtel-Dieu de France (HDF) hospital between 1994 and 2004. A total of 46 dilatations were performed in 41 patients with achalasia [20 males and 21 females, the mean age was 46.8 years (range, 15-90)]. All patients underwent an initial dilatation by inflating a 35 mm balloon to 7 psi three times successively under fluoroscopic control. The need for subsequent dilatation with the same technique or for surgical treatment was based on symptom assessment. The mean follow-up period was 36.7 months (3 mo-7 years). Among the patients whose follow-up information was available, a satisfactory result was achieved in 29 patients (80.5%) after only one or two sessions of pneumatic dilatation. Esophageal perforation as a short-term complication was observed in one patient (2.17%). Seven patients were referred for surgery (one for esophageal perforation and six for persistent or recurrent symptoms). In conclusion, performing balloon dilatation under fluoroscopic observation is simple, safe and efficacious for treating patients with achalasia. Referral to repeated PD or to surgical myotomy should be discussed in case of no response to a first session of PD.

  7. [Predicting value of thrombospondin-2 for coronary artery dilatation in patients with Kawasaki disease].

    PubMed

    Song, R X; Li, X H; Zhang, T; Cui, X D; Fu, J

    2016-04-01

    To investigate the predictive value of thrombospondin-2 in children with coronary artery dilatation secondary to Kawasaki disease. This study was a retrospective controlled study, the patients were divided into Kawasaki disease group and control group.Patients first time hospitalized in Children's Hospital Affiliated to Capital Institute of Pediatrics during the acute phase of Kawasaki disease were enrolled in Kawasaki disease group from May 2013 to August 2014.Sixty-four Kawasaki disease patients were enrolled into the Kawasaki disease group based on inclusion and exclusion criteria, including 39 males and 25 females, with an average age of 2.3 years.According to the results of echocardiography of children with Kawasaki disease, patients were divided into coronary artery dilatation group and non-coronary artery dilatation group, there were 33 cases in the coronary dilatation (CAD) group, 26 males and 7 females, the average age was 2.0 years, and 31 cases in the non-coronary dilatation (NCAD) group, 13 males and 18 females, the average age was 2.6 years.The control group consisted of children with fever but excluding vascular inflammatory diseases and healthy children, 32 cases in fever group, 19 males and 13 females, mean age was 4.5 years; in which healthy group had 32 cases, 18 males and 14 females and the average age was 3.3 years. Enzyme linked immunosorbent assay (ELISA) method was used to measure the levels of thrombospondin-1 (TSP-1) and TSP-2 in the plasma of each group, and the related laboratory parameters, and general information was analyzed.Multiple sets of normal distribution of data were compared by analysis of unifactorial analysis of variance and the two groups were compared by two independent samples t-test.Analysis of covariance was used to remove the effect of age.The χ(2) test was used to analyze categeorical data and receiver operating characteristic (ROC) curve for evaluating the predictive value of TSP-2. Compared with the febrile group

  8. Molecular profiling of dilated cardiomyopathy that progresses to heart failure

    PubMed Central

    Burke, Michael A.; Chang, Stephen; Wakimoto, Hiroko; Gorham, Joshua M.; Conner, David A.; Christodoulou, Danos C.; Parfenov, Michael G.; DePalma, Steve R.; Eminaga, Seda; Konno, Tetsuo; Seidman, Jonathan G.; Seidman, Christine E.

    2016-01-01

    Dilated cardiomyopathy (DCM) is defined by progressive functional and structural changes. We performed RNA-seq at different stages of disease to define molecular signaling in the progression from pre-DCM hearts to DCM and overt heart failure (HF) using a genetic model of DCM (phospholamban missense mutation, PLNR9C/+). Pre-DCM hearts were phenotypically normal yet displayed proliferation of nonmyocytes (59% relative increase vs. WT, P = 8 × 10–4) and activation of proinflammatory signaling with notable cardiomyocyte-specific induction of a subset of profibrotic cytokines including TGFβ2 and TGFβ3. These changes progressed through DCM and HF, resulting in substantial fibrosis (17.6% of left ventricle [LV] vs. WT, P = 6 × 10–33). Cardiomyocytes displayed a marked shift in metabolic gene transcription: downregulation of aerobic respiration and subsequent upregulation of glucose utilization, changes coincident with attenuated expression of PPARα and PPARγ coactivators -1α (PGC1α) and -1β, and increased expression of the metabolic regulator T-box transcription factor 15 (Tbx15). Comparing DCM transcriptional profiles with those in hypertrophic cardiomyopathy (HCM) revealed similar and distinct molecular mechanisms. Our data suggest that cardiomyocyte-specific cytokine expression, early fibroblast activation, and the shift in metabolic gene expression are hallmarks of cardiomyopathy progression. Notably, key components of these profibrotic and metabolic networks were disease specific and distinguish DCM from HCM. PMID:27239561

  9. A demonstration of ultra-high time resolution with a pulse-dilation photo-multiplier

    NASA Astrophysics Data System (ADS)

    Hares, J. D.; Dymoke-Bradshaw, A. K. L.; Hilsabeck, T. J.; Kilkenny, J. D.; Morris, D.; Horsfield, C. J.; Gales, S. G.; Milnes, J.; Herrmann, H. W.; McFee, C.

    2016-05-01

    A novel microchannel plate (MCP) intensified high-speed photo-multiplier tube making use of pulse-dilation[1] has been tested. A ramped photo-cathode voltage followed by a relatively long drift region results in a transit time which is dependent on the photo-electron birth time. This leads to temporal magnification or dilation, so providing an enhancement in time resolution of the optical signal with respect to the electrical signal at the output anode. By this means a time resolution on the order of picoseconds may be realized with a substantially slower oscilloscope. The photo-electron signal is guided from a photo-cathode to an MCP by an axial magnetic field and a short input record length is stretched by a factor up to 40X to yield significantly improved time resolution at the photo-cathode. Results of the first measurements are presented.

  10. Internal friction and absence of dilatancy of packings of frictionless polygons

    NASA Astrophysics Data System (ADS)

    Azéma, Émilien; Radjaï, Farhang; Roux, Jean-Noël

    2015-01-01

    By means of numerical simulations, we show that assemblies of frictionless rigid pentagons in slow shear flow possess an internal friction coefficient (equal to 0.183 ±0.008 with our choice of moderately polydisperse grains) but no macroscopic dilatancy. In other words, despite side-side contacts tending to hinder relative particle rotations, the solid fraction under quasistatic shear coincides with that of isotropic random close packings of pentagonal particles. Properties of polygonal grains are thus similar to those of disks in that respect. We argue that continuous reshuffling of the force-bearing network leads to frequent collapsing events at the microscale, thereby causing the macroscopic dilatancy to vanish. Despite such rearrangements, the shear flow favors an anisotropic structure that is at the origin of the ability of the system to sustain shear stress.

  11. Effects of intranasal oxytocin on pupil dilation indicate increased salience of socioaffective stimuli.

    PubMed

    Prehn, Kristin; Kazzer, Philipp; Lischke, Alexander; Heinrichs, Markus; Herpertz, Sabine C; Domes, Gregor

    2013-06-01

    To investigate the mechanisms by which oxytocin improves socioaffective processing, we measured behavioral and pupillometric data during a dynamic facial emotion recognition task. In a double-blind between-subjects design, 47 men received either 24 IU intranasal oxytocin (OXT) or a placebo (PLC). Participants in the OXT group recognized all facial expressions at lower intensity levels than did participants in the PLC group. Improved performance was accompanied by increased task-related pupil dilation, indicating an increased recruitment of attentional resources. We also found increased pupil dilation during the processing of female compared with male faces. This gender-specific stimulus effect diminished in the OXT group, in which pupil size specifically increased for male faces. Results suggest that improved emotion recognition after OXT treatment might be due to an intensified processing of stimuli that usually do not recruit much attention.

  12. Dilational and Compactional Shear Failure: Application to Siliciclastic Petroleum Reservoir rocks.

    NASA Astrophysics Data System (ADS)

    Casey, M.; Fisher, Q. J.; Knipe, R. J.

    2001-12-01

    Investigations related to the exploitation of oil reserves provide examples of brittle shear failure in rocks with well known burial, stress, temperature, compactional and diagenetic history. In addition, particular emphasis is placed on the dilational or compactional nature of the failure mode because of the influence this has on the permeability of the fault rocks. Microstructural investigations show that at shallow depths of less than 2.5 km failure during continued subsidence is by particulate flow and is usually compactional. At greater depths mechanical compaction may occur by particulate flow/ grain crushing or the rock may fail by dilational brittle failure. The main control on failure mode is the degree of cementation. At low cementation the rock fails by particulate flow (with or without fracture). Dilational shear failure occurs when the cementation has considerably reduced the porosity. We developed a model of cementation rate based on temperature controlled precipitation rate and used this to plot product of porosity and grain radius (a measure of susceptibility of the rock to crushing) against effective stress for some North Sea Reservoir rocks during their burial history. We found that the initially the low cementation rate held the crushing strength constant, causing the rocks to approach the empirical failure curve, but that at greater depths the increased cementation rate rapidly increased the strength, taking the rock mechanical state away from the failure line. Some deeply buried rocks were observed to have lower than expected amounts of cement and we ascribe this to the inhibition of precipitation by clay films. Deep, well cemented rocks, that failed by shear localised dilatant brittle shear were found to have higher permeabilities than expected on the basis of laboratory results. The natural specimens came from dilational jogs in a network of fault segments and we infer that the increased permeability is the result of deformation under

  13. Oxytocin enhances pupil dilation and sensitivity to ‘hidden’ emotional expressions

    PubMed Central

    Wessberg, Johan; Ellingsen, Dan-Mikael; Chelnokova, Olga; Olausson, Håkan; Laeng, Bruno

    2013-01-01

    Sensing others’ emotions through subtle facial expressions is a highly important social skill. We investigated the effects of intranasal oxytocin treatment on the evaluation of explicit and ‘hidden’ emotional expressions and related the results to individual differences in sensitivity to others’ subtle expressions of anger and happiness. Forty healthy volunteers participated in this double-blind, placebo-controlled crossover study, which shows that a single dose of intranasal oxytocin (40 IU) enhanced or ‘sharpened’ evaluative processing of others’ positive and negative facial expression for both explicit and hidden emotional information. Our results point to mechanisms that could underpin oxytocin’s prosocial effects in humans. Importantly, individual differences in baseline emotional sensitivity predicted oxytocin’s effects on the ability to sense differences between faces with hidden emotional information. Participants with low emotional sensitivity showed greater oxytocin-induced improvement. These participants also showed larger task-related pupil dilation, suggesting that they also allocated the most attentional resources to the task. Overall, oxytocin treatment enhanced stimulus-induced pupil dilation, consistent with oxytocin enhancement of attention towards socially relevant stimuli. Since pupil dilation can be associated with increased attractiveness and approach behaviour, this effect could also represent a mechanism by which oxytocin increases human affiliation. PMID:22648957

  14. Slip and Dilation Tendency Anlysis of McGinness Hills Geothermal Area

    DOE Data Explorer

    Faulds, James E.

    2013-12-31

    Slip and Dilation Tendency in focus areas Critically stressed fault segments have a relatively high likelihood of acting as fluid flow conduits (Sibson, 1994). As such, the tendency of a fault segment to slip (slip tendency; Ts; Morris et al., 1996) or to dilate (dilation tendency; Td; Ferrill et al., 1999) provides an indication of which faults or fault segments within a geothermal system are critically stressed and therefore likely to transmit geothermal fluids. The slip tendency of a surface is defined by the ratio of shear stress to normal stress on that surface: Ts = τ / σn (Morris et al., 1996). Dilation tendency is defined by the stress acting normal to a given surface: Td = (σ1-σn) / (σ1-σ3) (Ferrill et al., 1999). Slip and dilation were calculated using 3DStress (Southwest Research Institute). Slip and dilation tendency are both unitless ratios of the resolved stresses applied to the fault plane by ambient stress conditions. Values range from a maximum of 1, a fault plane ideally oriented to slip or dilate under ambient stress conditions to zero, a fault plane with no potential to slip or dilate. Slip and dilation tendency values were calculated for each fault in the focus study areas at, McGinness Hills, Neal Hot Springs, Patua, Salt Wells, San Emidio, and Tuscarora on fault traces. As dip is not well constrained or unknown for many faults mapped in within these we made these calculations using the dip for each fault that would yield the maximum slip tendency or dilation tendency. As such, these results should be viewed as maximum tendency of each fault to slip or dilate. The resulting along-fault and fault-to-fault variation in slip or dilation potential is a proxy for along fault and fault-to-fault variation in fluid flow conduit potential. Stress Magnitudes and directions Stress field variation within each focus area was approximated based on regional published data and the world stress database (Hickman et al., 2000; Hickman et al., 1998

  15. Relationship between dilatancy, stresses and plastic dissipation in a granular material with rigid grains

    NASA Astrophysics Data System (ADS)

    Evesque, Pierre; Stefani, Christian

    1991-11-01

    By considering a drained cohesionless granular sample made up of rigid grains and submitted to a triaxial test, we derive an equation relating the dilatancy K, the deviatoric stress q and the confining pressure p to the energy losses D_plastic due to plastic yielding. We demonstrate that the system is contracting (K le 0) at q = 0, when q is increasing and that spontaneous uncontrolled yielding begins occurring when dilatancy K is maximum. We also demonstrate the existence of the characteristic state introduced by Luong and Habib and the existence of the critical state of Schofield and Wroth. Finally, we give a method to determine the plastic losses during a triaxial cell test using the experimental data. En utilisant un postulat de reproductibilité des essais triaxiaux et une relation liant l'énergie dissipée, la dilatance K et les contraintes imposées à un échantillon, on démontre qu'un matériau granulaire ne peut que se contracter après avoir subi une contrainte de confinement isotrope (i.e. q = 0), que la rupture spontanée a lieu après un maximum de dilatance, qu'il existe un état caractéristique (au sens de Luong et Habib) et qu'il existe un état “ critique ” (au sens de Schofield et Wroth). Nous donnons de plus une méthode pour estimer la dissipation-plastique durant un essai triaxial à partir des résultats expérimentaux.

  16. Fixed and dilated: the history of a classic pupil abnormality.

    PubMed

    Koehler, Peter J; Wijdicks, Eelco F M

    2015-02-01

    The aim of this study was to investigate the development of ideas about the nature and mechanism of the fixed dilated pupil, paying particular attention to experimental conditions and clinical observations in the 19th century. Starting from Kocher's standard review in 1901, the authors studied German, English, and French texts for historical information. Medical and neurological textbooks from the 19th and 20th centuries were reviewed to investigate when and how this information percolated through neurological and neurosurgical practices. Cooper experimented with intracranial pressure (ICP) in a dog in the 1830s, but did not mention the pupils. He described dilated pupils in clinical cases without referring to the effect of light. Bright demonstrated to have some knowledge of the pupil sign (clinical observations). Realizing the unreliability of the pupil sign, Hutchinson in 1867-1868 tried to reason in which cases trepanation would be advisable. Von Leyden's 1866 animal experiments, in which he increased CSF volume by injecting protein solutions intracranially, was the first observation in which the association between fixed dilated pupils and increased ICP was established. Along with bradycardia and motor and respiratory effects, he noticed wide pupils were usually present in a comatose state. Asymmetrical dilation could not always be attributed to increased ICP, but to an oculomotor nerve lesion. Pagenstecher in 1871 extended knowledge by meticulously studying consecutive pupil phenomena with increasing pressure. In 1880, von Bergmann emphasized the significance of the ipsilateral dilation in experiments as well as in clinical cases. He distinguished the extent of pressure increase and its duration. Probably confusing irritation (epileptic head turning to the other side with pupil dilation) and lesion effects, he suggested a cortical area responsible for oculomotor phenomena, indicating what is now known as the frontal eye field. Naunyn and Schreiber (1881

  17. Clinical Effect of Endoscopic Pneumatic Dilation for Achalasia

    PubMed Central

    Cheng, Peng; Shi, Hai; Zhang, Yanjie; Zhou, Huabang; Dong, Jinhua; Cai, Yiting; Hu, Xing; Dai, Qiang; Yang, Wenyan

    2015-01-01

    Abstract Although pneumatic dilation is an accepted method for the treatment of achalasia, this therapy has high recurrence and complication rates, and prolonged follow-up studies on the parameters associated with various outcomes are rare. In this prospective 10-year follow-up study, a satisfactory therapeutic effect was achieved without serious complications. We report the therapeutic experience with pneumatic dilation, havin