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Sample records for flow-mediated dilation relation

  1. The Association of Homocysteine and Related Factors to Brachial Artery Diameter and Flow-Mediated Dilation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Brachial artery flow-mediated dilation (BAFMD) has been proposed as a measurement of the degree and severity of cardiovascular disease. The purpose of this study was to (1) evaluate the associations between BAFMD and homocysteine, folate, vitamin B12, vitamin B6, (2) examine the influence of 5,10-me...

  2. 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. PMID:27456517

  3. Cellular Adhesion Molecules in Healthy Subjects: Short Term Variations and Relations to Flow Mediated Dilation.

    PubMed

    Eschen, Ole; Christensen, Jeppe Hagstrup; Dethlefsen, Claus; Schmidt, Erik Berg

    2008-01-01

    The objective was primarily to describe short term intra-individual variation in serum levels of soluble adhesion molecules (sCAMs: E-selectin, P-selectin, intercellular adhesion molecule-1(sICAM-1) and vascular cellular adhesion molecule-1(sVCAM-1)) in healthy subjects. Secondly, sCAMs were correlated to brachial artery flow mediated vasodilation (FMD).Forty healthy subjects aged 24-66 years had sCAMs measured twice with 4 week intervals and short-term intra-individual variation was estimated as variation in the paired measurements after correcting for the analytical precision of the used method. At baseline, brachial FMD was measured.No difference was observed in mean sCAMs in the whole study group. Estimated intra-subject variations in sCAMs were 7.6-11.3%. In a regression analysis, significant negative association was found between sE-selectin and FMD after controlling for possible confounders (p < 0.04) while no significant correlation could be demonstrated between the other sCAMs and FMD.In conclusion, short term intra-individual variations in sCAMs were 7.6-11.3% in healthy subjects. We also found a significant negative association between sE-selectin and FMD, indicating an possible association between inflammation and dysfunction of the vascular endothelium; however further studies are required to confirm this preliminary finding.

  4. 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. PMID:25776455

  5. Velocity acceleration as a determinant of flow-mediated dilation.

    PubMed

    Stoner, Lee; McCully, Kevin K

    2012-04-01

    Shear stress is the established stimulus for flow-mediated dilation (FMD). In vivo, shear stress is typically estimated using mean blood velocity. However, mean blood velocity may not adequately characterize the shear stimulus. Pulsatile flow results in large shear gradients (velocity acceleration) at the onset of flow. The purpose of this study was to determine the importance of velocity acceleration to FMD. We define FMD as the brachial artery shear rate-diameter slope. Fourteen physically active, young (26 ± 5 years), male subjects were tested. Progressive forearm heating and handgrip exercise elicited steady-state increases in shear rate. FMD was measured prior to and following induced increases in velocity acceleration. Velocity acceleration was increased by inflating a tourniquet around the forearm to 40 mm Hg. Hierarchical linear modeling was used to estimate change in diameter with repeated measures of shear stress nested within each subject. Averaged across conditions, the 40 mm Hg cuff resulted in a 14% increase in velocity acceleration (p = 0.001). FMD was attenuated by 11.0% (p = 0.015) for the acceleration vs. control condition. However, after specifying velocity acceleration as a covariate, FMD was no longer significantly (p = 0.619) different between acceleration and control conditions. This finding suggests that mean blood velocity alone may not adequately characterize the shear stimulus.

  6. 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

  7. Impact of Rosuvastatin Treatment on HDL-Induced PKC-βII and eNOS Phosphorylation in Endothelial Cells and Its Relation to Flow-Mediated Dilatation in Patients with Chronic Heart Failure.

    PubMed

    Winzer, Ephraim B; Gaida, Pauline; Höllriegel, Robert; Fischer, Tina; Linke, Axel; Schuler, Gerhard; Adams, Volker; Erbs, Sandra

    2016-01-01

    Background. Endothelial function is impaired in chronic heart failure (CHF). Statins upregulate endothelial NO synthase (eNOS) and improve endothelial function. Recent studies demonstrated that HDL stimulates NO production due to eNOS phosphorylation at Ser(1177), dephosphorylation at Thr(495), and diminished phosphorylation of PKC-βII at Ser(660). The aim of this study was to elucidate the impact of rosuvastatin on HDL mediated eNOS and PKC-βII phosphorylation and its relation to endothelial function. Methods. 18 CHF patients were randomized to 12 weeks of rosuvastatin or placebo. At baseline, 12 weeks, and 4 weeks after treatment cessation we determined lipid levels and isolated HDL. Human aortic endothelial cells (HAEC) were incubated with isolated HDL and phosphorylation of eNOS and PKC-βII was evaluated. Flow-mediated dilatation (FMD) was measured at the radial artery. Results. Rosuvastatin improved FMD significantly. This effect was blunted after treatment cessation. LDL plasma levels were reduced after rosuvastatin treatment whereas drug withdrawal resulted in significant increase. HDL levels remained unaffected. Incubation of HAEC with HDL had no impact on phosphorylation of eNOS or PKC-βII. Conclusion. HDL mediated eNOS and PKC-βII phosphorylation levels in endothelial cells do not change with rosuvastatin in CHF patients and do not mediate the marked improvement in endothelial function. PMID:27563480

  8. Impact of Rosuvastatin Treatment on HDL-Induced PKC-βII and eNOS Phosphorylation in Endothelial Cells and Its Relation to Flow-Mediated Dilatation in Patients with Chronic Heart Failure

    PubMed Central

    Gaida, Pauline; Höllriegel, Robert; Fischer, Tina; Linke, Axel; Schuler, Gerhard; Adams, Volker; Erbs, Sandra

    2016-01-01

    Background. Endothelial function is impaired in chronic heart failure (CHF). Statins upregulate endothelial NO synthase (eNOS) and improve endothelial function. Recent studies demonstrated that HDL stimulates NO production due to eNOS phosphorylation at Ser1177, dephosphorylation at Thr495, and diminished phosphorylation of PKC-βII at Ser660. The aim of this study was to elucidate the impact of rosuvastatin on HDL mediated eNOS and PKC-βII phosphorylation and its relation to endothelial function. Methods. 18 CHF patients were randomized to 12 weeks of rosuvastatin or placebo. At baseline, 12 weeks, and 4 weeks after treatment cessation we determined lipid levels and isolated HDL. Human aortic endothelial cells (HAEC) were incubated with isolated HDL and phosphorylation of eNOS and PKC-βII was evaluated. Flow-mediated dilatation (FMD) was measured at the radial artery. Results. Rosuvastatin improved FMD significantly. This effect was blunted after treatment cessation. LDL plasma levels were reduced after rosuvastatin treatment whereas drug withdrawal resulted in significant increase. HDL levels remained unaffected. Incubation of HAEC with HDL had no impact on phosphorylation of eNOS or PKC-βII. Conclusion. HDL mediated eNOS and PKC-βII phosphorylation levels in endothelial cells do not change with rosuvastatin in CHF patients and do not mediate the marked improvement in endothelial function. PMID:27563480

  9. 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

  10. Flow-mediated dilation in the inactive limb following acute hypoxic exercise.

    PubMed

    Katayama, Keisho; Yamashita, Shin; Iwamoto, Erika; Ishida, Koji

    2016-01-01

    The purpose of this study was to elucidate the effect of acute aerobic exercise performed under hypoxic conditions on flow-mediated dilation (FMD) in the inactive limb. Seven males participated in the study. The subjects performed two submaximal leg cycling on a semirecumbent ergometer at the same relative intensity (60% peak oxygen uptake) in normoxia [inspired oxygen fraction (FIO2) = 0·21] and hypoxia (FIO2 = 0·12-0·13) for 30 min. The brachial artery diameter and blood velocity during exercise were measured via ultrasound, and the antegrade and retrograde shear rates were calculated. Before and 5, 30 and 60 min after exercise, brachial artery FMD was measured in normoxia. FMD was estimated as the percentage increase in peak diameter from the baseline diameter at prior occlusion (%FMD) and as the controlling changes in baseline diameter (the corrected-%FMD). No difference in antegrade shear rate during exercise was detected between the normoxic and hypoxic conditions, whereas the retrograde shear rate was larger during hypoxic exercise. The %FMD decreased significantly at 5 min after exercise in both normoxia and hypoxia, and it returned to pre-exercise levels within 60 min of recovery. Significant decreases in FMD at 5 min after exercise had disappeared when the baseline diameter was controlled using an analysis of covariance (the corrected-%FMD). No significant differences were observed between the normoxic and hypoxic trials in the %FMD and corrected-%FMD following exercise. These results suggest that hypoxia has no impact on endothelial function in the inactive limb following acute aerobic exercise.

  11. 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.

  12. Effects of dietary carbohydrate restriction versus low-fat diet on flow-mediated dilation.

    PubMed

    Volek, Jeff S; Ballard, Kevin D; Silvestre, Ricardo; Judelson, Daniel A; Quann, Erin E; Forsythe, Cassandra E; Fernandez, Maria Luz; Kraemer, William J

    2009-12-01

    We previously reported that a carbohydrate-restricted diet (CRD) ameliorated many of the traditional markers associated with metabolic syndrome and cardiovascular risk compared with a low-fat diet (LFD). There remains concern how CRD affects vascular function because acute meals high in fat have been shown to impair endothelial function. Here, we extend our work and address these concerns by measuring fasting and postprandial vascular function in 40 overweight men and women with moderate hypertriacylglycerolemia who were randomly assigned to consume hypocaloric diets (approximately 1500 kcal) restricted in carbohydrate (percentage of carbohydrate-fat-protein = 12:59:28) or LFD (56:24:20). Flow-mediated dilation of the brachial artery was assessed before and after ingestion of a high-fat meal (908 kcal, 84% fat) at baseline and after 12 weeks. Compared with the LFD, the CRD resulted in a greater decrease in postprandial triacylglycerol (-47% vs -15%, P = .007), insulin (-51% vs -6%, P = .009), and lymphocyte (-12% vs -1%, P = .050) responses. Postprandial fatty acids were significantly increased by the CRD compared with the LFD (P = .033). Serum interleukin-6 increased significantly over the postprandial period; and the response was augmented in the CRD (46%) compared with the LFD (-13%) group (P = .038). After 12 weeks, peak flow-mediated dilation at 3 hours increased from 5.1% to 6.5% in the CRD group and decreased from 7.9% to 5.2% in the LFD group (P = .004). These findings show that a 12-week low-carbohydrate diet improves postprandial vascular function more than a LFD in individuals with atherogenic dyslipidemia.

  13. Impact of sympathetic nervous system activity on post-exercise flow-mediated dilatation in humans.

    PubMed

    Atkinson, Ceri L; Lewis, Nia C S; Carter, Howard H; Thijssen, Dick H J; Ainslie, Philip N; Green, Daniel J

    2015-12-01

    Transient reduction in vascular function following systemic large muscle group exercise has previously been reported in humans. The mechanisms responsible are currently unknown. We hypothesised that sympathetic nervous system activation, induced by cycle ergometer exercise, would contribute to post-exercise reductions in flow-mediated dilatation (FMD). Ten healthy male subjects (28 ± 5 years) undertook two 30 min sessions of cycle exercise at 75% HR(max). Prior to exercise, individuals ingested either a placebo or an α1-adrenoreceptor blocker (prazosin; 0.05 mg kg(-1)). Central haemodynamics, brachial artery shear rate (SR) and blood flow profiles were assessed throughout each exercise bout and in response to brachial artery FMD, measured prior to, immediately after and 60 min after exercise. Cycle exercise increased both mean and antegrade SR (P < 0.001) with retrograde SR also elevated under both conditions (P < 0.001). Pre-exercise FMD was similar on both occasions, and was significantly reduced (27%) immediately following exercise in the placebo condition (t-test, P = 0.03). In contrast, FMD increased (37%) immediately following exercise in the prazosin condition (t-test, P = 0.004, interaction effect P = 0.01). Post-exercise FMD remained different between conditions after correction for baseline diameters preceding cuff deflation and also post-deflation SR. No differences in FMD or other variables were evident 60 min following recovery. Our results indicate that sympathetic vasoconstriction competes with endothelium-dependent dilator activity to determine post-exercise arterial function. These findings have implications for understanding the chronic impacts of interventions, such as exercise training, which affect both sympathetic activity and arterial shear stress.

  14. Isometric handgrip training improves local flow-mediated dilation in medicated hypertensives.

    PubMed

    McGowan, Cheri L; Visocchi, Adrienne; Faulkner, Martha; Verduyn, Robin; Rakobowchuk, Mark; Levy, Andrew S; McCartney, Neil; Macdonald, Maureen J

    2006-11-01

    Bilateral isometric handgrip (IHG) training lowers resting arterial blood pressure (BP) in medicated hypertensives. Numerous mechanisms have been suggested, but have yet to be investigated. One such mechanism is that of improved systemic endothelial-dependent vasodilation. The purpose of this investigation was twofold: (1) to determine if Bilateral IHG training had any beneficial effects on endothelial-dependent vasodilation, and (2) to see if improved systemic endothelial-dependent vasodilation was responsible for lowering BP. Sixteen participants performed four, 2 min IHG contractions at 30% of their maximal voluntary effort, using either a Bilateral (n = 7) or a Unilateral IHG protocol (n = 9), three times per week for 8 weeks. Brachial artery (BA) flow-mediated dilation (FMD, an index of endothelial-dependent vasodilation, measured in both arms) was assessed pre-and post-training. Following Bilateral IHG training, BA FMD improved in both arms (normalized to peak shear rate, 0.005 +/- 0.001 to 0.02 +/- 0.002 s(-1), P < 0.01). Following Unilateral IHG training, BA FMD improved in the trained arm only (normalized: 0.009 +/- 0.002 to 0.02 +/- 0.005 s(-1), P < 0.01). These findings suggest that although IHG training improves endothelial-dependent vasodilation, the improvements occur only locally in the trained limbs. This suggests that enhanced systemic endothelial-dependent vasodilation is not the mechanism responsible for the observed post-IHG training reductions in BP in medicated hypertensives. PMID:16924526

  15. A prospective clinical study of flow-mediated dilatation in burn injury.

    PubMed

    Turk, Emin; Caliskan, Mustafa; Karagulle, Erdal; Aydogan, Cem; Oguz, Hakan; Kulaksizoglu, Sevsen; Yildirim, Erkan; Moray, Gokhan; Haberal, Mehmet

    2014-01-01

    The authors investigated endothelial function using flow-mediated dilatation (FMD) in burn patients. This study was done in burn patients with specific criteria on admission. Blood lipid profile at 1st day, high-sensitivity C-reactive protein, and FMD were assessed at 1st and 7th days, as well as at 1st and 3rd months. The highest values of high-sensitivity C-reactive protein were detected on the 7th day, which were significantly higher than those at 1st and 3rd months. The lowest value of FMD was observed on the 7th day. FMD values were higher during the 1st month compared with the 7th day. The highest value of FMD was detected in the 3rd month. It was found that FMD values measured at 7th day and 1st month were significantly lower in patients with a burn percentage of 40 or greater. Our results suggest that inflammation is more prominent on 7th day following burn. The decrease in FMD values on 7th day after injury can be attributed to endothelial damage. The increase in FMD on 3rd month after burn is attributable to effective burn treatment and gradual decrease of inflammatory mediators. The data from this study suggest that there is endothelial dysfunction and low-grade inflammation in burn patients. This condition is more prominent in patients with a burn ratio greater than 40%. Burn patients more frequently have impaired FMD, which may be indicative of arterial endothelial dysfunction and a marker for increased atherosclerosis.

  16. 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.

  17. Peroxynitrite reduces the endothelium-derived hyperpolarizing factor component of coronary flow-mediated dilation in PECAM-1-knockout mice.

    PubMed

    Liu, Yanping; Bubolz, Aaron H; Shi, Yang; Newman, Peter J; Newman, Debra K; Gutterman, David D

    2006-01-01

    Platelet endothelial cell adhesion molecule 1 (PECAM-1) is capable of transducing signals in endothelial cells exposed to shear; however, the biological consequences of this signal transduction are unknown. Because shear stress elicits flow-mediated dilation (FMD), we examined whether steady-state FMD in mouse coronary arteries (MCAs) is affected in the PECAM-1 knockout (KO) mouse. MCAs were isolated from wild-type (WT) or KO mice and prepared for videomicroscopy, histofluorescence, Western blotting, and immunohistochemistry. FMD was examined in the absence and presence of N(omega)-nitro-l-arginine methyl ester (l-NAME) and l-NAME+indomethacin (INDO). FMD was reduced in KO relative to WT MCAs, but the l-NAME-inhibitable portion of FMD was similar between the two. The INDO-sensitive component of FMD was diminished in KO MCAs. In contrast, the residual component of dilation, presumably because of endothelium-derived hyperpolarizing factor (EDHF), was abolished in KO MCAs. Histofluorescence showed relatively more superoxide (O2-.; oxy-ethidium fluorescence) and peroxide production (dihydrochlorofluorescene fluoresecence) in KO MCAs at rest. Flow augmented O2-. and peroxide production in WT MCAs but had little effect on KO MCAs. Enhanced nitric oxide generation was observed in arteries from KO mice, accompanied with increased eNOS S1177 phosphorylation. In vessels from KO mice, treatment with ebselen decreased peroxynitrite (ONOO-) formation and improved the reduced FMD, largely due to restoration of the presumed EDHF component. These results suggest that PECAM-1 is necessary for normal FMD in the mouse coronary circulation. In the absence of this adhesion and signaling molecule, ONOO- production is increased concomitant with a reduction in both the EDHF and INDO-sensitive components of FMD. PMID:16166207

  18. 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.

  19. Higher Levels of Adiponectin in Vascular Endothelial Cells are Associated with Greater Brachial Artery Flow-mediated Dilation in Older Adults

    PubMed Central

    Yoo, Jeung-Ki; Hwang, Moon-Hyon; Luttrell, Meredith J.; Kim, Han-Kyul; Meade, Thomas H.; English, Mark; Segal, Mark S.; Christou, Demetra D.

    2015-01-01

    Adiponectin, an adipocyte-derived protein, exerts anti-atherosclerotic effects on the vascular endothelium. Recently adiponectin protein has been reported in murine vascular endothelial cells, however, whether adiponectin is present in human vascular endothelial cells remains unexplored. We sought to examine 1) adiponectin protein in vascular endothelial cells collected from older adults free of overt cardiovascular disease; 2) the relation between endothelial cell adiponectin and in vivo vascular endothelial function; and 3) the relation between endothelial cell adiponectin, circulating (plasma) adiponectin and related factors. We measured vascular endothelial function (brachial artery flow-mediated dilation using ultrasonography), vascular endothelial cell adiponectin (biopsy coupled with quantitative immunofluorescence) and circulating adiponectin (Mercodia, ELISA) in older, sedentary, non-smoking, men and women (55 – 79 years). We found that higher endothelial cell adiponectin was related with greater flow-mediated dilation (r=0.43, P<0.05) and greater flow-mediated dilation normalized for shear stress (r=0.56, P<0.01), but was not related with vascular smooth muscle responsiveness to nitric oxide (r=0.04, P=0.9). Vascular endothelial cell adiponectin was not related with circulating adiponectin (r=−0.14, P=0.6). Endothelial cell and circulating adiponectin were differentially associated with adiposity, metabolic and other factors, but both were inversely associated with renal function (r=0.44 to 0.62, P ≤ 0.04). In conclusion, higher endothelial cell adiponectin levels are associated with higher vascular endothelial function, independent of circulating adiponectin levels in older adults. PMID:25572013

  20. Effect of black tea consumption on brachial artery flow-mediated dilation and ischaemia-reperfusion in humans.

    PubMed

    Schreuder, Tim H A; Eijsvogels, Thijs M H; Greyling, Arno; Draijer, Richard; Hopman, Maria T E; Thijssen, Dick H J

    2014-02-01

    Tea consumption is associated with reduced cardiovascular risk. Previous studies found that tea flavonoids work through direct effects on the vasculature, leading to dose-dependent improvements in endothelial function. Cardioprotective effects of regular tea consumption may relate to the prevention of endothelial ischaemia-reperfusion (IR) injury. Therefore, we examined the effect of black tea consumption on endothelial function and the ability of tea to prevent IR injury. In a randomized, crossover study, 20 healthy subjects underwent 7 days of tea consumption (3 cups per day) or abstinence from tea. We examined brachial artery (BA) endothelial function via flow-mediated dilation (FMD), using high resolution echo-Doppler, before and 90 min after tea or hot water consumption. Subsequently, we followed a 20-min ischaemia and 20-min reperfusion protocol of the BA after which we measured FMD to examine the potential of tea consumption to protect against IR injury. Tea consumption resulted in an immediate increase in FMD% (pre-consumption: 5.8 ± 2.5; post-consumption: 7.2 ± 3.2; p < 0.01), whilst no such change occurred after ingestion of hot water. The IR protocol resulted in a significant decrease in FMD (p < 0.005), which was also present after tea consumption (p < 0.001). This decline was accompanied by an increase in the post-IR baseline diameter. In conclusion, these data indicate that tea ingestion improves BA FMD. However, the impact of the IR protocol on FMD was not influenced by tea consumption. Therefore, the cardioprotective association of tea ingestion relates to a direct effect of tea on the endothelium in humans in vivo.

  1. 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.

  2. 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. PMID:27320045

  3. 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.

  4. 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. PMID:24465021

  5. Impaired Flow-mediated Dilation Is Associated with Low Pulmonary Function and Emphysema in Ex-smokers

    PubMed Central

    Barr, R. Graham; Mesia-Vela, Sonia; Austin, John H. M.; Basner, Robert C.; Keller, Brad M.; Reeves, Anthony P.; Shimbo, Daichi; Stevenson, Lori

    2007-01-01

    Rationale: Basic science research suggests a causal role for endothelial dysfunction in chronic obstructive pulmonary disease (COPD). Clinical studies examining endothelial function are lacking, particularly early in the disease. Flow-mediated dilation (FMD) is a physiologic measure of endothelial reactivity to endogenous nitric oxide. Objectives: We hypothesized that lower FMD among former smokers would be associated with lower post-bronchodilator FEV1, higher percentage of emphysema using computed tomography (CT) and lower diffusing capacity. Methods: We measured FMD, pulmonary function, and CT percentage of emphysema in a random sample of 107 cotinine-confirmed former smokers in the ongoing EMCAP study. FMD was defined as percentage change in the brachial artery diameter with reactive hyperemia. Generalized additive models were used to adjust for potential confounders and assess linearity. Measurements and Main Results: Mean age of participants was 71 ± 5 years, 46% were female, and pack-years averaged 48 ± 26. Mean FMD was 3.8 ± 3.1%; mean post-bronchodilator FEV1, 2.3 ± 0.8 L; and mean CT percentage of emphysema, 26 ± 10%. A 1 SD decrease in FMD was associated with a 132-ml (95% confidence interval, 16–248 ml; P = 0.03) decrement in post-bronchodilator FEV1 and a 2.6% (95% confidence interval, 0.5–4.7%; P = 0.02) increase in CT percentage of emphysema in fully adjusted models. These associations were linear across the spectrum from normality to disease, independent of smoking history, and also significant among participants without COPD. Associations with diffusing capacity were consistent but nonsignificant (P = 0.09). The FMD–FEV1 association was entirely attributable to percentage of emphysema. Conclusions: Impaired endothelial function, as measured by FMD, was associated with lower FEV1 and higher CT percentage of emphysema in former smokers early in COPD. PMID:17761614

  6. The percentage flow-mediated dilation index: a large-sample investigation of its appropriateness, potential for bias and causal nexus in vascular medicine.

    PubMed

    Atkinson, Greg; Batterham, Alan M

    2013-12-01

    The percentage flow-mediated dilation index (FMD%) scales the increase in arterial diameter (Ddiff) as a constant proportion of baseline artery diameter (Dbase). We have demonstrated, albeit with small samples, that the scaling properties of FMD% can lead to biased inferences on endothelial dysfunction. Therefore, we aimed to investigate the underlying rationale and potential bias of FMD% using a selection of new examples from the large (n = 3499) and diverse Multi-Ethnic Study of Atherosclerosis (MESA). In this dataset, we found that smaller values of Ddiff are associated with larger values of Dbase, which contradicts the scaling properties of FMD%. Consequently, FMD% 'over-scales' and naturally generates an even stronger negative correlation between itself and Dbase. Using a data simulation, we show that this FMD%-Dbase correlation can be a statistical artefact due to inappropriate scaling. The new examples we present from MESA indicate that FMD% biases the differences in flow-mediated response between men and women, Framingham risk score categories, and diseased and healthy people. We demonstrate how FMD%, as an exposure for predicting cardiovascular disease, is confounded by its dependency on Dbase, which itself could be clinically important. This critical review, incorporating an allometric analysis of a large dataset, suggests that the FMD% index has a less-than-clear rationale, can itself generate the Dbase-dependency problem, provides biased estimates of differences in the flow-mediated response, complicates the interpretation of the flow-mediated protocol and clouds the causal pathway to vascular disease. These interpretative problems can be resolved by applying accepted allometric principles to the flow-mediated response.

  7. Flow Mediated Dilatation Is Reduced with the Progressive Stages of Glomerular Filtration Rate and Albuminuria in Type 2 Diabetic Patients without Coronary Heart Disease

    PubMed Central

    Ito, Hiroyuki; Nakashima, Mina; Meguro, Kentaro; Furukawa, Haruki; Yamashita, Hitomi; Takaki, Akifusa; Yukawa, Chizuko; Omoto, Takashi; Shinozaki, Masahiro; Nishio, Shinya; Abe, Mariko; Antoku, Shinichi; Mifune, Mizuo; Togane, Michiko

    2015-01-01

    We aimed to clarify the usefulness of measuring the flow mediated dilatation (FMD) in patients with type 2 diabetes mellitus without and with coronary heart disease (CHD). The FMD was measured in 480 patients with type 2 diabetes and in 240 nondiabetic subjects. The FMD was significantly lower in the subjects with CHD (n = 145, 5.4 ± 3.2%) than in those without CHD (n = 95, 6.9 ± 3.5%) among the nondiabetic subjects. The FMD was also lower in the subjects both with CHD (n = 161, 5.6 ± 2.8%) and without CHD (n = 319, 6.1 ± 3.3%) among the patients with diabetes compared to those without both diabetes and CHD. The FMD showed a significant positive correlation with the estimated glomerular filtration rate (eGFR) in the diabetic patients without CHD, while there was no significant association in those with CHD. The FMD was significantly lower with the progressive stages of the GFR or albuminuria in the patients without CHD among those with diabetes, although the FMD was not different in those with CHD. In conclusion, the FMD is considered to be useful for the detection of atherosclerosis in patients with type 2 diabetes, even if overt macroangiopathy is not diagnosed. PMID:26064988

  8. 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

  9. 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.

  10. 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.

  11. 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.

  12. 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

  13. Effect of hawthorn standardized extract on flow mediated dilation in prehypertensive and mildly hypertensive adults: a randomized, controlled cross-over trial

    PubMed Central

    2012-01-01

    Background Hawthorn extract has been used for cardiovascular diseases for centuries. Recent trials have demonstrated its efficacy for the treatment of heart failure, and the results of several small trials suggest it may lower blood pressure. However, there is little published evidence to guide its dosing. The blood pressure lowering effect of hawthorn has been linked to nitric oxide-mediated vasodilation. The aim of this study was to investigate the relationship between hawthorn extract dose and brachial artery flow mediated dilation (FMD), an indirect measure of nitric oxide release. Methods We used a four-period cross-over design to evaluate brachial artery FMD in response to placebo or hawthorn extract (standardized to 50 mg oligomeric procyanidin per 250 mg extract). Randomly sequenced doses of hawthorn extract (1000 mg, 1500 mg, and 2500 mg) and placebo were assigned to each participant. Doses were taken twice daily for 3 1/2 days followed by FMD and a 4-day washout before proceeding to the next dosing period. Results Twenty-one prehypertensive or mildly hypertensive adults completed the study. There was no evidence of a dose-response effect for our main outcome (FMD percent) or any of our secondary outcomes (absolute change in brachial artery diameter and blood pressure). Most participants indicated that if given evidence that hawthorn could lower their blood pressure, they would be likely to use it either in conjunction with or instead of lifestyle modification or anti-hypertensive medications. Conclusion We found no evidence of a dose-response effect of hawthorn extract on FMD. If hawthorn has a blood pressure lowering effect, it is likely to be mediated via an NO-independent mechanism. Trial Registration This trial has been registered with ClinicalTrials.gov, a service of the U.S. National Institutes of Health: NCT01331486. PMID:22458601

  14. Elevated C-Reactive Protein Levels and Enhanced High Frequency Vasomotion in Patients with Ischemic Heart Disease during Brachial Flow-Mediated Dilation

    PubMed Central

    Watanabe, Shogo; Amiya, Eisuke; Watanabe, Masafumi; Takata, Munenori; Ozeki, Atsuko; Watanabe, Aya; Kawarasaki, Shuichi; Nakao, Tomoko; Hosoya, Yumiko; Nagata, Kohzo; Nagai, Ryozo; Komuro, Issei

    2014-01-01

    Purpose The physiological role of vasomotion, rhythmic oscillations in vascular tone or diameter, and its underlying mechanisms are unknown. We investigated the characteristics of brachial artery vasomotion in patients with ischemic heart disease (IHD). Methods We performed a retrospective study of 37 patients with IHD. Endothelial function was assessed using flow-mediated dilation (FMD), and power spectral analysis of brachial artery diameter oscillations during FMD was performed. Frequency-domain components were calculated by integrating the power spectrums in three frequency bands (in ms2) using the MemCalc (GMS, Tokyo, Japan): very-low frequency (VLF), 0.003–0.04 Hz; low frequency (LF), 0.04–0.15 Hz; and high frequency (HF), 0.15–0.4 Hz. Total spectral power (TP) was calculated as the sum of all frequency bands, and each spectral component was normalized against TP. Results Data revealed that HF/TP closely correlated with FMD (r = −0.33, p = 0.04), whereas VLF/TP and LF/TP did not. We also explored the relationship between elevated C-reactive protein (CRP) levels and vasomotion. HF/TP was significantly increased in subjects with high CRP levels (CRP;>0.08 mg/dL) compared with subjects with low CRP levels (0.052±0.026 versus 0.035±0.022, p<0.05). The HF/TP value closely correlated with CRP (r = 0.24, p = 0.04), whereas the value of FMD did not (r = 0.023, p = 0.84). In addition, elevated CRP levels significantly increased the value of HF/TP after adjustment for FMD and blood pressure (β = 0.33, p<0.05). Conclusion The HF component of brachial artery diameter oscillation during FMD measurement correlated well with FMD and increased in the presence of elevated CRP levels in subjects with IHD. PMID:25299643

  15. Brachial artery diameter has a predictive value in the improvement of flow-mediated dilation after aortic valve replacement for aortic stenosis.

    PubMed

    Takata, Munenori; Amiya, Eisuke; Watanabe, Masafumi; Ozeki, Atsuko; Watanabe, Aya; Kawarasaki, Shuichi; Nakao, Tomoko; Hosoya, Yumiko; Uno, Kansei; Saito, Aya; Murasawa, Takahide; Ono, Minoru; Nagai, Ryozo; Komuro, Issei

    2015-03-01

    Aortic stenosis (AS) is the most common valvular disease and aortic valve replacement (AVR) is one of its most effective interventions. AS affects not only the left ventricle, but also vascular function beyond the stenotic valve, which can lead to various types of vascular dysfunction. However, research evaluating the effect of AS on aortic vascular function is limited. In this study, we investigated clinical meaning to evaluate endothelial function in subjects with AS. From April 2011 to April 2012, 20 consecutive adult patients with degenerative AS (mean age, 74.7 ± 7.4 years; range 50-83 years) who underwent AVR at our institution were included in the study. We measured flow-mediated dilation (FMD) to evaluate the effect of AS on endothelial function. The difference between brachial artery diameter (BAD) before (4.0 ± 0.7 mm) and after AVR (3.9 ± 0.6 mm) was not significant (p = 0.043), but FMD significantly improved after AVR (from 3.1 ± 1.8 to 6.0 ± 2.7 %, p < 0.0001). We also analyzed FMD × BAD index, endogenous vasodilatory capability independent of BAD, resulting that it also significantly increased after AVR (12.3 ± 7.0-22.5 ± 9.3, p < 0.0001). We divided patients into two groups by pre- to post-AVR change in FMD (ΔFMD); large-ΔFMD group [ΔFMD >3.0 % (median value)] and small-ΔFMD group (ΔFMD <3.0 %). There were no significant changes in age, blood pressure, heart rate, B-type natriuretic peptide, or echocardiographic parameters in either group. In contrast, BAD was significantly larger in the small ΔFMD group (4.3 ± 0.7 mm) than in the large ΔFMD group (3.7 ± 0.7 mm) (p = 0.030). In addition, cardio-thoracic ratio was significantly greater in the small ΔFMD group (58.4 ± 7.1 %) than in the large ΔFMD group (53.7 ± 4.6 %) (p = 0.048). Receiver operating characteristic curve analysis of BAD to differentiate large and small ΔFMD demonstrated an area under the curve of 0.750 (p = 0.059) and that optimal cutoff for BAD was 4.28 mm (70

  16. Impairment of endothelium-dependent dilation is an early event in children with familial hypercholesterolemia and is related to the lipoprotein(a) level.

    PubMed Central

    Sorensen, K E; Celermajer, D S; Georgakopoulos, D; Hatcher, G; Betteridge, D J; Deanfield, J E

    1994-01-01

    Familial hypercholesterolemia is associated with premature atherosclerosis. Since endothelial dysfunction is an early event in atherogenesis, we used a noninvasive method to assess endothelial function in the systemic arteries of 30 children aged 7-17 yr (median 11) with familial hypercholesterolemia (2 homozygotes, 28 heterozygotes, total cholesterol 240-696 mg/dl) and 30 healthy age- and sex-matched controls. Using high resolution ultrasound, the diameter of the superficial femoral artery was measured at rest, in response to reactive hyperemia (with increased flow causing endothelium-dependent dilation), and after sublingual glyceryltrinitrate (causing endothelium-independent vasodilation). Flow-mediated dilation was present in the controls (7.5 +/- 0.7%) but was impaired or absent in the hypercholesterolemic children (1.2 +/- 0.4%, P < 0.0001). Total cholesterol was inversely correlated with flow-mediated dilation (r = -0.61, P < 0.0001). In the hypercholesterolemic children, flow-mediated dilation was inversely related to the lipoprotein(a) level (r = -0.61, P = 0.027) but not to other lipid fractions. Glyceryltrinitrate-induced dilation was present in all subjects but was lower in the hypercholesterolemia group (10.0 +/- 0.6% vs 12.4 +/- 0.8%, P = 0.023). Thus, impaired endothelium-dependent dilation is present in children with familial hypercholesterolemia as young as 7 yr of age and the degree of impairment is related to the lipoprotein(a) level. Images PMID:8282821

  17. Assessing the perceived quality of brachial artery Flow Mediated Dilation studies for inclusion in meta-analyses and systematic reviews: Description of data employed in the development of a scoring ;tool based on currently accepted guidelines.

    PubMed

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

    2016-09-01

    Brachial artery Flow Mediated Dilation (FMD) is widely used as a non-invasive measure of endothelial function. Adherence to expert consensus guidelines on FMD measurement has been found to be of vital importance to obtain reproducible data. This article lists the literature data which was considered in the development of a tool to aid in the objective judgement of the extent to which published studies adhered to expert guidelines for FMD measurement. Application of this tool in a systematic review of FMD studies (http://dx.doi.org/10.1016/j.atherosclerosis.2016.03.011) (Greyling et al., 2016 [1]) indicated that adherence to expert consensus guidelines is strongly correlated to the reproducibility of FMD data.

  18. Assessing the perceived quality of brachial artery Flow Mediated Dilation studies for inclusion in meta-analyses and systematic reviews: Description of data employed in the development of a scoring ;tool based on currently accepted guidelines.

    PubMed

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

    2016-09-01

    Brachial artery Flow Mediated Dilation (FMD) is widely used as a non-invasive measure of endothelial function. Adherence to expert consensus guidelines on FMD measurement has been found to be of vital importance to obtain reproducible data. This article lists the literature data which was considered in the development of a tool to aid in the objective judgement of the extent to which published studies adhered to expert guidelines for FMD measurement. Application of this tool in a systematic review of FMD studies (http://dx.doi.org/10.1016/j.atherosclerosis.2016.03.011) (Greyling et al., 2016 [1]) indicated that adherence to expert consensus guidelines is strongly correlated to the reproducibility of FMD data. PMID:27284565

  19. 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

    2003-11-01

    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).

  20. Sprint interval and traditional endurance training induce similar improvements in peripheral arterial stiffness and flow-mediated dilation in healthy humans.

    PubMed

    Rakobowchuk, Mark; Tanguay, Sophie; Burgomaster, Kirsten A; Howarth, Krista R; Gibala, Martin J; MacDonald, Maureen J

    2008-07-01

    Low-volume sprint interval training (SIT), or repeated sessions of brief, intense intermittent exercise, elicits metabolic adaptations that resemble traditional high-volume endurance training (ET). The effects of these different forms of exercise training on vascular structure and function remain largely unexplored. To test the hypothesis that SIT and ET would similarly improve peripheral artery distensibility and endothelial function and central artery distensibility, we recruited 20 healthy untrained subjects (age: 23.3 +/- 2.8 yr) and had them perform 6 wk of SIT or ET (n = 5 men and 5 women per group). The SIT group completed four to six 30-s "all-out" Wingate tests separated by 4.5 min of recovery 3 days/wk. The ET group completed 40-60 min of cycling at 65% of their peak oxygen uptake (Vo2peak) 5 days/wk. Popliteal endothelial function, both relative and normalized to shear stimulus, was improved after training in both groups (main effect for time, P < 0.05). Carotid artery distensibility was not statistically altered by training (P = 0.29) in either group; however, popliteal artery distensibility was improved in both groups to the same degree (main effect, P < 0.05). We conclude that SIT is a time-efficient strategy to elicit improvements in peripheral vascular structure and function that are comparable to ET. However, alterations in central artery distensibility may require a longer training stimuli and/or greater initial vascular stiffness than observed in this group of healthy subjects.

  1. 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

    2003-11-01

    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). PMID:14611572

  2. 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.

  3. Percutaneous balloon dilatation of the mitral valve: an analysis of echocardiographic variables related to outcome and the mechanism of dilatation.

    PubMed Central

    Wilkins, G T; Weyman, A E; Abascal, V M; Block, P C; Palacios, I F

    1988-01-01

    Twenty two patients (four men, 18 women, mean age 56 years, range 21 to 88 years) with a history of rheumatic mitral stenosis were studied by cross sectional echocardiography before and after balloon dilatation of the mitral valve. The appearance of the mitral valve on the pre-dilatation echocardiogram was scored for leaflet mobility, leaflet thickening, subvalvar thickening, and calcification. Mitral valve area, left atrial volume, transmitral pressure difference, pulmonary artery pressure, cardiac output, cardiac rhythm, New York Heart Association functional class, age, and sex were also studied. Because there was some increase in valve area in almost all patients the results were classified as optimal or suboptimal (final valve area less than 1.0 cm2, final left atrial pressure greater than 10 mm Hg, or final valve area less than 25% greater than the initial area). The best multiple logistic regression fit was found with the total echocardiographic score alone. A high score (advanced leaflet deformity) was associated with a suboptimal outcome while a low score (a mobile valve with limited thickening) was associated with an optimal outcome. No other haemodynamic or clinical variables emerged as predictors of outcome in this analysis. Examination of pre-dilatation and post-dilatation echocardiograms showed that balloon dilatation reliably resulted in cleavage of the commissural plane and thus an increase in valve area. Images Fig 1 Fig 2 Fig 3 Fig 4 Fig 6 PMID:3190958

  4. 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…

  5. 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

  6. 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.

  7. Bougie dilators: simple, safe and cost-effective treatment for Crohn’s-related fibrotic anal strictures

    PubMed Central

    Kashkooli, Soleiman B.; Samanta, Sujon; Rouhani, Mehrdad; Akbarzadeh, Shoaleh; Saibil, Fred

    2015-01-01

    Summary Anal strictures with fibrotic induration have been shown to develop in up to 50% of all patients with Crohn’s disease (CD) with anal ulceration. We evaluate the technical feasibility, safety and long-term efficacy of bougie dilation for a subgroup of patients with symptomatic Crohn’s-related fibrotic anal strictures. Bougie dilation is simple to perform, relatively inexpensive and has a low risk of complications. PMID:26204140

  8. 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

  9. Relation of maternal anti-Ro/La antibodies to aortic dilation in patients with congenital complete heart block.

    PubMed

    Davey, Debra L; Bratton, Susan L; Bradley, David J; Yetman, Anji T

    2011-08-15

    An association between congenital complete atrioventricular block (cCAVB) and aortic dilation during childhood has recently been reported. We sought to further explore this relation with particular emphasis on the natural history of aortic abnormalities over time. The relation of maternal anti-Ro/La antibody status to the aortic size of children affected with cCAVB was also assessed. The patients were evaluated longitudinally with serial echocardiography. During a 15-year period, 62 patients at our institution were diagnosed with cCAVB, of whom 40% were exposed to maternal autoimmune antibodies and 35% were not. The antibody status in the remaining patients was unknown. The patients underwent 9.3 ± 6.5 echocardiograms during the follow-up period. Dilation of the ascending aorta, defined as a z score >2.0, was present on the initial echocardiogram in all patients exposed to maternal antibodies and persisted during long-term follow-up in 96% of these patients. In contrast, 5% and 10% of patients without exposure to maternal autoimmune antibodies had aortic dilation on the initial and follow-up studies, respectively (p <0.001 and p <0.001, respectively). In conclusion, patients with autoimmune-mediated cCAVB merit periodic echocardiographic monitoring into adulthood to assess persistent or progressive aortic dilation and its attendant complications.

  10. "The choledocho-pancreatic long common channel disorders" in relation to the etiology of congenital biliary dilatation and other biliary tract disease.

    PubMed

    Miyano, T; Suruga, K; Suda, K

    1981-10-01

    The amylase level of bile and various cholangiograms was studied in 36 cases of congenital biliary dilatation. (C.B.D.) The amylase level above 10000 U/L was considered to suggest the existence of choledocho-pancreatic long common channel formation. Radiologically, the dilatation of intrahepatic bile duct was seen in 9 out of 19 (47%) Type I cases and in all (100%) Type II cases. The cystic dilatation of intrahepatic bile duct was seen in all Type I cases which have cystic choledochal dilatation. On the other hand, fusiform dilatation was seen in all Type II cases with fusiform choledochal dilatation. End to side Choledocho-pancreatic anastomosis was performed to produce an experimental model of human choledocho-pancreatic long common channel disorders, thus leading to the dilatation of the common bile duct as well as the reflux of pancreatic juice into the bile duct. The reflux of Pancreatic juice and congenital stricture due to the choledocho-pancreatic long common channel formation were considered to be the important causative factors in the etiology of C.B.D.. Furthermore, pathology of the choledocho-pancreatic long common channel disorders was found to be important in relation to the etiology of both C.B.D. and other lesions of the biliary tract and pancreas.

  11. Genetics Home Reference: familial dilated cardiomyopathy

    MedlinePlus

    ... Related Dilated Cardiomyopathy Genetic Testing Registry (1 link) Primary dilated cardiomyopathy ClinicalTrials.gov (1 link) ClinicalTrials.gov Scientific articles on PubMed (1 link) PubMed OMIM (36 links) ...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  13. Data on the circulating levels of endothelial microparticles are elevated in patients with bicuspid aortic valve and are related to aortic dilation.

    PubMed

    Alegret, Josep M; Martínez-Micaelo, Neus; Aragonès, Gerard; Beltrán-Debón, Raúl

    2016-09-01

    The data included here support the research article "Circulating endothelial microparticles are elevated in bicuspid aortic valve (BAV) disease and related to aortic dilation" (Alegret et al., 2016 [1]) where circulating levels of platelet endothelial cell adhesion molecule (PECAM(+)) endothelial microparticles (EMPs) were identified as a biological variable related to aortic dilation in patients with BAV disease. The data presented in this article are composed by four tables and one figure containing the clinical and echocardiographic characteristics of the patients (Alegret et al., 2016 [1]) included in this study, and summarize the results of multivariate linear analyses. Furthermore, is also included a figure showing a representative flow cytometry dot plots and histograms used in PECAM(+) EMPs quantification is also included. PMID:27453924

  14. Th17-Related Cytokines in Systemic Lupus Erythematosus Patients with Dilated Cardiomyopathies: A Possible Linkage to Parvovirus B19 Infection

    PubMed Central

    Chen, Der-Yuan; Chen, Yi-Ming; Lan, Joung-Liang

    2014-01-01

    Dilated cardiomyopathies (DCM) are a major cause of mortality in patients with systemic lupus erythematosus (SLE). Immune responses induced by human parvovirus B19 (B19) are considered an important pathogenic mechanism in myocarditis or DCM. However, little is known about Th17-related cytokines in SLE patients with DCM about the linkage with B19 infection. IgM and IgG against B19 viral protein, and serum levels of Th17-related cytokines were determined using ELISA in eight SLE patients with DCM and six patients with valvular heart disease (VHD). Humoral responses of anti-B19-VP1u and anti-B19-NS1 antibody were assessed using Western blot and B19 DNA was detected by nested Polymerase Chain Reaction (PCR). Levels of interleukin (IL)-17, IL-6, IL-1β, and tumor necrosis factor (TNF)-α were significantly higher in SLE patients with DCM (mean ± SEM, 390.99±125.48 pg/ml, 370.24±114.09 pg/ml, 36.01±16.90 pg/ml, and 183.84±82.94 pg/ml, respectively) compared to healthy controls (51.32±3.04 pg/ml, p<0.001; 36.88±6.64 pg/ml, p<0.001; 5.39±0.62 pg/ml, p<0.005; and 82.13±2.42 pg/ml, p<0.005, respectively). Levels of IL-17 and IL-6 were higher in SLE patients with DCM versus those with VHD (both p<0.01). Five (62.5%) of DCM patients had detectable anti-B19-NS1 IgG and four (50.0%) of them had anti-B19-VP1u IgG, whereas only one (16.7%) of VHD patients had detectable anti-B19-NS1 IgG and anti-B19-VP1u IgG. Serum levels of IL-17, IL-6 and IL-1β were markedly higher in SLE patients with anti-B19-VP1u IgG and anti-B19-NS1 IgG compared to those without anti-B19-VP1u IgG or anti-B19-NS1 IgG, respectively. These suggest a potential association of B19 with DCM and Th17-related cytokines implicated in the pathogenesis of DCM in SLE patients. PMID:25462010

  15. Th17-related cytokines in systemic lupus erythematosus patients with dilated cardiomyopathies: a possible linkage to parvovirus B19 infection.

    PubMed

    Chen, Der-Yuan; Chen, Yi-Ming; Tzang, Bor-Show; Lan, Joung-Liang; Hsu, Tsai-Ching

    2014-01-01

    Dilated cardiomyopathies (DCM) are a major cause of mortality in patients with systemic lupus erythematosus (SLE). Immune responses induced by human parvovirus B19 (B19) are considered an important pathogenic mechanism in myocarditis or DCM. However, little is known about Th17-related cytokines in SLE patients with DCM about the linkage with B19 infection. IgM and IgG against B19 viral protein, and serum levels of Th17-related cytokines were determined using ELISA in eight SLE patients with DCM and six patients with valvular heart disease (VHD). Humoral responses of anti-B19-VP1u and anti-B19-NS1 antibody were assessed using Western blot and B19 DNA was detected by nested Polymerase Chain Reaction (PCR). Levels of interleukin (IL)-17, IL-6, IL-1β, and tumor necrosis factor (TNF)-α were significantly higher in SLE patients with DCM (mean ± SEM, 390.99±125.48 pg/ml, 370.24±114.09 pg/ml, 36.01±16.90 pg/ml, and 183.84±82.94 pg/ml, respectively) compared to healthy controls (51.32±3.04 pg/ml, p<0.001; 36.88±6.64 pg/ml, p<0.001; 5.39±0.62 pg/ml, p<0.005; and 82.13±2.42 pg/ml, p<0.005, respectively). Levels of IL-17 and IL-6 were higher in SLE patients with DCM versus those with VHD (both p<0.01). Five (62.5%) of DCM patients had detectable anti-B19-NS1 IgG and four (50.0%) of them had anti-B19-VP1u IgG, whereas only one (16.7%) of VHD patients had detectable anti-B19-NS1 IgG and anti-B19-VP1u IgG. Serum levels of IL-17, IL-6 and IL-1β were markedly higher in SLE patients with anti-B19-VP1u IgG and anti-B19-NS1 IgG compared to those without anti-B19-VP1u IgG or anti-B19-NS1 IgG, respectively. These suggest a potential association of B19 with DCM and Th17-related cytokines implicated in the pathogenesis of DCM in SLE patients.

  16. Modeling the pressure-dilatation correlation

    NASA Technical Reports Server (NTRS)

    Sarkar, S.

    1991-01-01

    It is generally accepted that pressure dilatation, which is an additional compressibility term in turbulence transport equations, may be important for high speed flows. Recent direct simulations of homogeneous shear turbulence have given concrete evidence that the pressure dilatation is important insofar that it contributes to the reduced growth of turbulent kinetic energy due to compressibility effects. The problem of modeling pressure dilatation is addressed. A component of the pressure dilatation is isolated which exhibits temporal oscillations and, using direct numerical simulations of homogeneous shear turbulence and isotropic turbulence, show that it has a negligible contribution to the evolution of turbulent kinetic energy. Then, an analysis for the case of homogeneous turbulence is performed to obtain a model for the nonoscillatory pressure dilatation. This model algebraically relates the pressure dilatation to quantities traditionally obtained in incompressible turbulence closures. The model is validated by direct comparison with the pressure dilatation data obtained from the simulations.

  17. Dilating Eye Drops

    MedlinePlus

    ... Conditions Most Common Searches Adult Strabismus Amblyopia Cataract Conjunctivitis Corneal Abrasions Dilating Eye Drops Lazy eye (defined) ... Loading... Most Common Searches Adult Strabismus Amblyopia Cataract Conjunctivitis Corneal Abrasions Dilating Eye Drops Lazy eye (defined) ...

  18. 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

    2015-04-01

    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.

  19. 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.

  20. Pneumatic dilatation for childhood achalasia.

    PubMed

    Babu, R; Grier, D; Cusick, E; Spicer, R D

    2001-09-01

    Treatment of achalasia by pneumatic balloon dilatation (PBD) is well established in adults. Due to limited experience and the rarity of the condition in children, there are relatively few reports in the paediatric literature. Although PBD has been reported as a primary method of treatment, there are no reports of secondary PBD for childhood achalasia. Between 1995 and 1999, five patients underwent treatment for achalasia (age: 9-14 years, M:F = 4:1). The presenting symptoms were dysphagia (5). vomiting episodes (2), aspiration (1), food-bolus obstruction (1), and failure to thrive (1). In all patients a barium swallow and manometry were used to confirm the diagnosis. Three underwent primary PBD. Two who had previously undergone surgical myotomy underwent secondary PBD for recurrence of symptoms. Dilatation was performed using a 35-mm balloon with the child under general anaesthesia. Technical success was defined as demonstration of a waist under screening at lower pressures followed by abolition of the waist at higher pressures. In addition to reviewing our results, a systematic review of the literature was performed (Medline, Cochrane Library, Pubmed, Embase). Three patients (primary dilatation) showed excellent improvement after a single dilatation. In two cases (secondary dilatation) three and five attempts were required. No complications were encountered. The mean follow-up period was 2 years (1-3.5 years) and four patients remained asymptomatic, an overall success rate of 80%. The literature review revealed similar good results in most of the recent reports. Thus, PBD as a primary treatment for childhood achalasia has a success rate of 70%-90% with minimal side effects, short hospital stay, and good patient acceptability over an operation. We have also established the usefulness of this method as a secondary treatment when symptoms recur after surgery.

  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. 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

  3. Incidence of dilated cardiomyopathy

    PubMed Central

    Abelmann, Walter H.

    1985-01-01

    Full reliable data on the incidence and prevalence of dilated cardiomyopathy are not available. In the United States, at least 0.7% of cardiac deaths are attributable to cardiomyopathy. Dilated cardiomyopathy probably contributes the great majority of these cases. The mortality rate for cardiomyopathy in males is twice that of females, and for blacks it is 2.4 times that of whites. Cardiomyopathy was diagnosed in 0.67% of patients discharged from hospitals in 1979 with diagnoses of disease of the circulatory system. Cardiomyopathy accounted for 1% of general cardiologists' and for 7% of academic cardiologists' patient encounters. In Scandinavia, population surveys suggested an annual incidence of dilated cardiomyopathy ranging from 0.73 to 7.5 cases per 100,000 population; for Tokyo this figure is 2.6. The prevalence of cardiomyopathy in underdeveloped and in tropical countries is considerably higher than in developed countries.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. Dilation and Curettage (D&C)

    MedlinePlus

    ... Advocacy For Patients About ACOG Dilation and Curettage (D&C) Home For Patients Search FAQs Dilation and ... FAQ062, February 2016 PDF Format Dilation and Curettage (D&C) Special Procedures What is dilation and curettage ( ...

  9. 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)

  10. 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.

  11. 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.

  12. A micromechanical study of dilatancy of granular materials

    NASA Astrophysics Data System (ADS)

    Kruyt, N. P.; Rothenburg, L.

    2016-10-01

    In micromechanics of granular materials, relationships are investigated between micro-scale characteristics of particles and contacts and macro-scale, continuum characteristics. Dilatancy is an important property of granular materials, defined as volume changes (dilative or compressive) induced by shear deformation. To obtain detailed information at the micro-scale, two-dimensional Discrete Element Method simulations of isobaric tests with disk-shaped particles have been performed. The required information includes the fabric tensor which characterizes statistical properties of the contact network. The dependence of the dilatancy rate on the shear strength and the fabric tensor has been investigated, based on the results of the simulations employing a dense and a loose initial system. The dilatancy rate depends in a complex, non-unique way on the shear strength, while the dependence on the fabric tensor is more amenable to analytical description. Two micromechanical mechanisms of dilatancy have been identified: (i) dilatancy due to deformation of loops that are determined by the interparticle contact network and (ii) dilatancy due to topological changes in the interparticle contact network that correspond to the creation or disruption of contacts. For the first mechanism the anisotropy in the contact network is the primary parameter, while for the second mechanism the average number of contacts per particle is the primary parameter. A fabric-based micromechanical relation for the dilatancy rate has been formulated that describes these identified mechanisms. Parameters present in this relation are determined by fitting this relation to the results of the Discrete Element Method simulations, using combined data for the dense and the loose initial system. Employing these fitted coefficients, good agreement is obtained between the results of the simulations and the predictions of the micromechanical dilatancy relation.

  13. Dilated cardiomyopathy: an anaesthetic challenge.

    PubMed

    Kaur, Haramritpal; Khetarpal, Ranjana; Aggarwal, Shobha

    2013-06-01

    Idiopathic dilated cardiomyopathy is a primary myocardial disease of unknown etiology characterized by left ventricular or biventricular dilation and impaired contractility. Depending upon diagnostic criteria used, the reported annual incidence varies between 5 and 8 cases per 100,000 populations. Dilated cardiomyopathy is defined by presence of: a) fractional myocardial shortening less than 25% (>2SD) and/or ejection fraction less than 45% (>2SD) and b) Left Ventricular End Diastolic Diameter (LVEDD) greater than 117% excluding any known cause of myocardial disease. Such cases are always a challenge to the anesthesiologist as they are most commonly complicated by progressive cardiac failure. We report the anesthetic management of a patient with dilated cardiomyopathy undergoing surgery for carcinoma breast. PMID:23905133

  14. Dilatancy in slow granular flows.

    PubMed

    Kabla, Alexandre J; Senden, Tim J

    2009-06-01

    When walking on wet sand, each footstep leaves behind a temporarily dry impression. This counterintuitive observation is the most common illustration of the Reynolds principle of dilatancy: that is, a granular packing tends to expand as it is deformed, therefore increasing the amount of porous space. Although widely called upon in areas such as soil mechanics and geotechnics, a deeper understanding of this principle is constrained by the lack of analytical tools to study this behavior. Using x-ray radiography, we track a broad variety of granular flow profiles and quantify their intrinsic dilatancy behavior. These measurements frame Reynolds dilatancy as a kinematic process. Closer inspection demonstrates, however, the practical importance of flow induced compaction which competes with dilatancy, leading more complex flow properties than expected. PMID:19658906

  15. Dilatancy in Slow Granular Flows

    NASA Astrophysics Data System (ADS)

    Kabla, Alexandre J.; Senden, Tim J.

    2009-06-01

    When walking on wet sand, each footstep leaves behind a temporarily dry impression. This counterintuitive observation is the most common illustration of the Reynolds principle of dilatancy: that is, a granular packing tends to expand as it is deformed, therefore increasing the amount of porous space. Although widely called upon in areas such as soil mechanics and geotechnics, a deeper understanding of this principle is constrained by the lack of analytical tools to study this behavior. Using x-ray radiography, we track a broad variety of granular flow profiles and quantify their intrinsic dilatancy behavior. These measurements frame Reynolds dilatancy as a kinematic process. Closer inspection demonstrates, however, the practical importance of flow induced compaction which competes with dilatancy, leading more complex flow properties than expected.

  16. 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.

  17. 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.

  18. Analysis of Compressible Mixing Layers Using Dilatational Covariances Model

    NASA Technical Reports Server (NTRS)

    Thangam, S.; Zhou, Y.; Ristorcelli, J. R.

    1996-01-01

    Compressible mixing layers are analyzed using a dilatational covariances model based on a pseudo-sound constitutive relation. The calculations are used to evaluate the different physical phenomena affecting compressible mixing layers. The rate of growth of the mixing layer is retarded by both the compressible dissipation and the pressure-dilatational covariances. The pressure-dilatational, essentially a nonequilibrium effect, reduces the amount of excess production over dissipation available for the turbulence energy growth. The pseudo-sound model also includes a history dependent portion: this is also investigated. All constants in the model and used in these computations are predicted by the theory.

  19. Universal decoherence due to gravitational time dilation

    NASA Astrophysics Data System (ADS)

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

    2016-05-01

    The absence of quantum behavior on macroscopic scales is usually attributed to decoherence -- the suppression of quantum superpositions due to interaction with an environment. Here we show that time dilation provides a universal decoherence mechanism for any complex system. The effect takes place even for isolated particles that do not interact with any external environment and causes decoherence of position and momentum of the center of mass of the system. While time dilation is very weak on earth, it is already sufficient to decohere gram-scale objects and complex molecules. The results show that novel phenomena arise at the interplay between quantum theory and general relativity even in the low energy limit. Possible experimental verifications of the effect are briefly discussed.

  20. Chronic respiratory illness as a predictor of survival in idiopathic dilated cardiomyopathy: the Washington, DC, Dilated Cardiomyopathy Study.

    PubMed Central

    Martin, S. A.; Coughlin, S. S.; Metayer, C.; René, A. A.; Hammond, I. W.

    1996-01-01

    Although bronchial asthma and emphysema have been associated with idiopathic dilated cardiomyopathy in case-control studies, little is known about the prognostic importance of chronic respiratory disease in idiopathic dilated cardiomyopathy. To study this, we examined history of bronchial asthma, emphysema and chronic bronchitis, and respiratory medication use as possible predictors of survival in idiopathic dilated cardiomyopathy using data from a Washington, DC, population-based study (n = 129). The cumulative survival rates among patients with a history of emphysema or chronic bronchitis were 60% and 48% at 12 and 36 months, respectively, compared with 81.8% and 67.2% among patients without emphysema or chronic bronchitis. The survival rates of idiopathic dilated cardiomyopathy patients with and without a history of bronchial asthma at the time of idiopathic dilated cardiomyopathy diagnosis were similar. In multivariate analysis using the proportional hazards model, only ventricular arrhythmias and ejection fraction were found to be statistically significant predictors of survival in idiopathic dilated cardiomyopathy. The adjusted relative risk estimate for emphysema and chronic bronchitis was close to one. Thus, the results of this population-based study do not suggest that history of chronic respiratory illness is an independent predictor of survival in idiopathic dilated cardiomyopathy. PMID:8961693

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

    PubMed

    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. PMID:27097104

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

    PubMed

    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.

  3. 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

  4. 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

  5. Aortic dilatation and aortopathy in congenital heart diseases.

    PubMed

    Zanjani, Keyhan Sayadpour; Niwa, Koichiro

    2013-01-01

    Longer survival after corrective surgery for congenital heart diseases has rendered late complications more important. One of these complications is aortic dilatation which may occur in patients with repaired or unrepaired disease and can progress to aneurysm, dissection, and rupture. This aortic dilatation in various congenital heart diseases does not simply mean anatomical dilatation of the aortic root, but it closely relates to the aortic pathophysiological abnormality, aortic regurgitation, and aortic and ventricular dysfunction; therefore, we can recognize this complex lesion as a new concept: "aortopathy". The pathophysiology of this disease is complex and only partially understood. In this review, we first discuss history, pathophysiology, and clinical features of aortic dilatation and aortopathy of congenital heart disease. Then we provide a review of the evaluation and management of this disease.

  6. Identification of a novel flow-mediated gene expression signature in patients with bicuspid aortic valve.

    PubMed

    Maleki, Shohreh; Björck, Hanna M; Folkersen, Lasse; Nilsson, Roland; Renner, Johan; Caidahl, Kenneth; Franco-Cereceda, Anders; Länne, Toste; Eriksson, Per

    2013-01-01

    Individuals with bicuspid aortic valve (BAV) are at significantly higher risk of developing serious aortic complications than individuals with tricuspid aortic valves (TAV). Studies have indicated an altered aortic blood flow in patients with BAV; however, the extent to which altered flow influences the pathological state of BAV aorta is unclear. In the present study, we dissected flow-mediated aortic gene expression in patients undergoing elective open heart surgery. A large collection of public microarray data sets were firstly screened for consistent co-expression with five well-characterized flow-regulated genes (query genes). Genes with co-expression probability of >0.5 were selected and further analysed in expression profiles (127 arrays) from ascending aorta of BAV and TAV patients. Forty-four genes satisfied two filtering criteria: a significant correlation with one or more of the query genes (R > 0.40) and differential expression between patients with BAV and TAV. No gene fulfilled the criteria in mammary artery (88 arrays), an artery not in direct contact with the valve. Fifty-five percent of the genes significantly altered between BAV and TAV patients showed differential expression between two identified flow regions in the rat aorta. A large proportion of the identified genes were related to angiogenesis and/or wound healing, with pro-angiogenesis genes downregulated and inhibitory genes upregulated in patients with BAV. Moreover, differential expression of ZFP36, GRP116 and PKD2 was confirmed using immunohistochemistry. Implementing a new strategy, we have demonstrated an angiostatic gene expression signature in patients with BAV, indicating impaired wound healing in these patients, potentially involved in BAV-associated aortopathy. PMID:22903503

  7. 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.

  8. Molecular Pathology of Dilated Cardiomyopathies.

    PubMed

    Pathak, S K; Kukreja, R C; Hess, M

    1996-02-01

    The term idiopathic, defined as being of unknown etiology or mechanism, is no longer applicable to the dilated cardiomyopathies. The tools of molecular biology and clinical investigation have made significant progress, and it is now to the rare and exceptional case that one is forced to apply the term idiopathic. Further, having arrived at more precise cause, direct therapeutic intervention will become possible. The concept of gene insertion and "genetic therapy" is under active investigation. Unfortunately, the significant advances in the cause and disease mechanisms of DCM have not been matched in therapeutics. With few exceptions, we indirectly treat the DCMs by managing the CHF syndrome. However, several important points have emerged. The concept of LV afterload reduction is valid and efficacious. The use of vasodilator therapy has significantly reduced both mortality and morbidity and, in certain forms of cardiomyopathy (e.g., hypertensive, alcoholic, and doxorubicin-related), have significantly altered hemodynamics and permitted the injured heart to heal and return to a near normal functional state. However, as much as we want to congratulate ourselves on the progress bought with the use of vasodilators and ACE inhibitors, one must keep in mind that under the best of circumstances, the DCMs still carry an unacceptably high morbidity and mortality. A 40% to 50% 4- to 5-year mortality rate is depressing. Herein lies the challenge. With the significant progress in pathogenesis and etiology, we now stand at the threshold of new, innovative advances in therapeutics. These new concepts in both therapeutics and prevention will require courage, dedication, and hard work. But bit by bit, these seemingly insolvable problems will yield to the discipline and imagination of the investigator. The DCMs will continue to be a challenging problem for future investigators. Progress has been dramatic, and it should continue even at an accelerated pace as we approach the twenty

  9. Asymptomatic Bile Duct Dilatation in Children: Is It a Disease?

    PubMed Central

    Son, Yeo Ju; Lee, Mi Jung; Koh, Hong

    2015-01-01

    Purpose Bile duct dilatation is a relatively common sonographic finding; nevertheless, its clinical significance in children is controversial because little research has been done in the area. Therefore, we investigated the natural course and clinical significance of biliary duct dilatation in children. Methods We performed a retrospective study of 181 children (range, 1-day-old to 17-year-old) in whom dilatation of the intrahepatic duct and/or common hepatic duct and/or common bile duct was detected by abdominal ultrasonography at the Severance Children's Hospital between November 2005 and March 2014. We reviewed and analyzed laboratory test results, clinical manifestations, and clinical course in these patients. Results Pediatric patients (n=181) were enrolled in the study and divided into two groups. The first group included 59 subjects, without definitive cause of bile duct dilatation, who did not require treatment; the second group included 122 subjects, with definitive cause of bile duct dilatation or underlying biliary disease, who did require treatment. In the first group, 24 patients (40.7%) showed spontaneous resolution of bile duct dilatation, 20 patients (33.9%) showed no change, and 15 patients (25.4%) were lost to follow-up. In the second group, 31 patients were diagnosed with choledochal cysts, and 91 patients presented with biliary tract dilatations due to secondary causes, such as gallbladder or liver disease, post-operative complications, or malignancy. Conclusion Biliary dilatation in pediatric patients without symptoms, and without laboratory and other sonographic abnormalities, showed a benign clinical course. No pathologic conditions were noted on follow-up ultrasonography. PMID:26473138

  10. 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

  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... dilator is a device designed to dilate the anal sphincter and canal when the size of the anal opening...

  12. Volume dilatation in a polycarbonate blend at varying strain rates

    NASA Astrophysics Data System (ADS)

    Hiermaier, S.; Huberth, F.

    2012-05-01

    Impact loaded polymers show a variety of strain-rate dependent mechanical properties in their elastic, plastic and failure behaviour. In contrast to purely crystalline materials, the volume of polymeric materials can significantly change under irreversible deformations. In this paper, uni-axial tensile tests were performed in order to measure the dilatation in the Polycarbonate-Acrylnitril-Butadien-Styrol (PC-ABS) Bayblend T65. The accumulation of dilatation was measured at deformation speeds of 0.1 and 500 [ mm/ s]. Instrumented with a pair of two high-speed cameras, volume segments in the samples were observed. The change in volume was quantified as relation between the deformed and initial volumes of the segments. It was observed that the measured dilatations are of great significance for the constitutive models. This is specifically demonstrated through comparisons of stress-strain relations derived from the two camera-perspectives with isochoric relations based on single-surface observations of the same experiments.

  13. Multisensory signalling enhances pupil dilation

    PubMed Central

    Rigato, Silvia; Rieger, Gerulf; Romei, Vincenzo

    2016-01-01

    Detecting and integrating information across the senses is an advantageous mechanism to efficiently respond to the environment. In this study, a simple auditory-visual detection task was employed to test whether pupil dilation, generally associated with successful target detection, could be used as a reliable measure for studying multisensory integration processing in humans. We recorded reaction times and pupil dilation in response to a series of visual and auditory stimuli, which were presented either alone or in combination. The results indicated faster reaction times and larger pupil diameter to the presentation of combined auditory and visual stimuli than the same stimuli when presented in isolation. Moreover, the responses to the multisensory condition exceeded the linear summation of the responses obtained in each unimodal condition. Importantly, faster reaction times corresponded to larger pupil dilation, suggesting that also the latter can be a reliable measure of multisensory processes. This study will serve as a foundation for the investigation of auditory-visual integration in populations where simple reaction times cannot be collected, such as developmental and clinical populations. PMID:27189316

  14. 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

  15. 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.

  16. 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.

  17. 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

  18. 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. PMID:24427126

  19. Dilated cardiomyopathy due to a phospholamban duplication.

    PubMed

    Lee, Teresa M; Addonizio, Linda J; Chung, Wendy K

    2014-10-01

    Dilated cardiomyopathy is characterised by dilation and impaired systolic function. We present the case of a child with dilated cardiomyopathy caused by a 624 kb duplication of 6q22.31, which includes the phospholamban gene. The patient also has failure to thrive and developmental delay due to complex cytogenetic abnormalities including a 5p15 deletion associated with Cri du Chat and an 11p15 duplication associated with Russell-Silver syndrome. PMID:24451198

  20. 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...

  1. 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...

  2. 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...

  3. 21 CFR 876.5470 - Ureteral dilator.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 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....

  4. 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....

  5. 21 CFR 876.5450 - Rectal dilator.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 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...

  6. 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 DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5520 Urethral dilator....

  7. 21 CFR 876.5470 - Ureteral dilator.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 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....

  8. 21 CFR 876.5470 - Ureteral dilator.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 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....

  9. 21 CFR 876.5520 - Urethral dilator.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 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....

  10. 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 DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5520 Urethral dilator....

  11. 21 CFR 876.5450 - Rectal dilator.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 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...

  12. 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....

  13. 21 CFR 876.5450 - Rectal dilator.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 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...

  14. 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...

  15. 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....

  16. 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....

  17. 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....

  18. Outpatient experience with oesophageal endoscopic dilation.

    PubMed

    Jani, P G; Mburugu, P G

    1998-07-01

    Between March 1990 and August 1997, outpatient endoscopic balloon dilation was performed for oesophageal strictures which developed secondary to malignancies, peptic strictures, post surgical narrowing, achalasia cardia, corrosive ingestion and other causes. A total of 169 dilations were performed in the 92 cases with an average of 1.8 dilation/case (Range 1 to 8). Dilation was possible in all 92 cases without the need for fluoroscopic monitoring. Twenty three (13.6%) of the dilations were performed using pneumatic balloon while in 146(86.4%) cases wire guided metal olives were used. There were nine minor complications which were treated with medication on an outpatient basis and four major complications which required inpatient care. Three of these had perforation of the oesophagus and one died. One other patient developed aspiration pneumonia and subsequently died.

  19. Dilation framing camera with 4 ps resolution

    NASA Astrophysics Data System (ADS)

    Cai, Houzhi; Zhao, Xin; Liu, Jinyuan; Xie, Weixin; Bai, Yanli; Lei, Yunfei; Liao, Yubo; Niu, Hanben

    2016-04-01

    A framing camera using pulse-dilation technology is reported in this article. The camera uses pulse dilation of an electron signal from a pulsed photo-cathode (PC) to achieve high temporal resolution. While the PC is not pulsed, the measured temporal resolution of the camera without pulse-dilation is about 71 ps. While the excitation pulse is applied on the PC, the measured temporal resolution is improved to 4 ps by using the pulse-dilation technology. The spatial resolution of the dilation framing camera is also measured, which is better than 100 μm. The relationship between the temporal resolution and the PC bias voltage is obtained. The variation of the temporal resolution with the gradient of the PC excitation pulse is also provided.

  20. 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.

  1. 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

  2. Genetics Home Reference: dilated cardiomyopathy with ataxia syndrome

    MedlinePlus

    ... dilated cardiomyopathy with ataxia syndrome dilated cardiomyopathy with ataxia syndrome Enable Javascript to view the expand/collapse ... Open All Close All Description Dilated cardiomyopathy with ataxia (DCMA) syndrome is an inherited condition characterized by ...

  3. 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

  4. An Erupted Dilated Odontoma: A Rare Presentation.

    PubMed

    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.

  5. 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. PMID:23650303

  6. 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...

  7. 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...

  8. 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...

  9. 21 CFR 876.5365 - Esophageal dilator.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 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...

  10. 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

  11. Dysregulated flow-mediated vasodilatation in the human placenta in fetal growth restriction

    PubMed Central

    Jones, Sarah; Bischof, Helen; Lang, Ingrid; Desoye, Gernot; Greenwood, Sue L; Johnstone, Edward D; Wareing, Mark; Sibley, Colin P; Brownbill, Paul

    2015-01-01

    Increased vascular resistance and reduced fetoplacental blood flow are putative aetiologies in the pathogenesis of fetal growth restriction (FGR); however, the regulating sites and mechanisms remain unclear. We hypothesised that placental vessels dictate fetoplacental resistance and in FGR exhibit endothelial dysfunction and reduced flow-mediated vasodilatation (FMVD). Resistance was measured in normal pregnancies (n = 10) and FGR (n = 10) both in vivo by umbilical artery Doppler velocimetry and ex vivo by dual placental perfusion. Ex vivo FMVD is the reduction in fetal-side inflow hydrostatic pressure (FIHP) following increased flow rate. Results demonstrated a significant correlation between vascular resistance measured in vivo and ex vivo in normal pregnancy, but not in FGR. In perfused FGR placentas, vascular resistance was significantly elevated compared to normal placentas (58 ± 7.7 mmHg and 36.8 ± 4.5 mmHg, respectively; 8 ml min−1; means ± SEM; P < 0.0001) and FMVD was severely reduced (3.9 ± 1.3% and 9.1 ± 1.2%, respectively). In normal pregnancies only, the highest level of ex vivo FMVD was associated with the lowest in vivo resistance. Inhibition of NO synthesis during perfusion (100 μm l-NNA) moderately elevated FIHP in the normal group, but substantially in the FGR group. Human placenta artery endothelial cells from FGR groups exhibited increased shear stress-induced NO generation, iNOS expression and eNOS expression compared with normal groups. In conclusion, fetoplacental resistance is determined by placental vessels, and is increased in FGR. The latter also exhibit reduced FMVD, but with a partial compensatory increased NO generation capacity. The data support our hypothesis, which highlights the importance of FMVD regulation in normal and dysfunctional placentation. Key points A correlation was found between in vivo umbilical artery Doppler velocimetry and resistance to fetal-side flow in the human ex vivo dually

  12. Ultrasound Assessment of Endothelial-Dependent Flow-Mediated Vasodilation of the Brachial Artery in Clinical Research

    PubMed Central

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

    2014-01-01

    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

  13. Transfer of nitric oxide by blood from upstream to downstream resistance vessels causes microvascular dilation

    PubMed Central

    Zhou, X.; Unthank, J. L.; Miller, S. J.; Bills, R.

    2009-01-01

    The discovery that hemoglobin, albumin, and glutathione carry and release nitric oxide (NO) may have consequences for movement of NO by blood within microvessels. We hypothesize that NO in plasma or bound to proteins likely survives to downstream locations. To confirm this hypothesis, there must be a finite NO concentration ([NO]) in arteriolar blood, and upstream resistance vessels must be able to increase the vessel wall [NO] of downstream arterioles. Arteriolar blood NO was measured with NO-sensitive microelectrodes, and vessel wall [NO] was consistently 25–40% higher than blood [NO]. Localized suppression of NO production in large arterioles over 500–1,000 μm with l-nitroarginine reduced the [NO] ∼40%, indicating as much as 60% of the wall NO was from blood transfer. Flow in mesenteric arteries was elevated by occlusion of adjacent arteries to induce a flow-mediated increase in arterial NO production. Both arterial wall and downstream arteriolar [NO] increased and the arterioles dilated as the blood [NO] was increased. To study receptor-mediated NO generation, bradykinin was locally applied to upstream large arterioles and NO measured there and in downstream arterioles. At both sites, [NO] increased and both sets of vessels dilated. When isoproterenol was applied to the upstream vessels, they dilated, but neither the [NO] or diameter downstream arterioles increased. These observations indicate that NO can move in blood from upstream to downstream resistance vessels. This mechanism allows larger vessels that generate large [NO] to influence vascular tone in downstream vessels in response to both flow and receptor stimuli. PMID:19666847

  14. 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....

  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....

  16. 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....

  17. 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....

  18. 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....

  19. 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.

  20. Characteristic adaptations of the extracellular matrix in dilated cardiomyopathy.

    PubMed

    Louzao-Martinez, Laura; Vink, Aryan; Harakalova, Magdalena; Asselbergs, Folkert W; Verhaar, Marianne C; Cheng, Caroline

    2016-10-01

    Dilated cardiomyopathy (DCM) is a relatively common heart muscle disease characterized by the dilation and thinning of the left ventricle accompanied with left ventricular systolic dysfunction. Myocardial fibrosis is a major feature in DCM and therefore it is inevitable that corresponding extracellular matrix (ECM) changes are involved in DCM onset and progression. Increasing our understanding of how ECM adaptations are involved in DCM could be important for the development of future interventions. This review article discusses the molecular adaptations in ECM composition and structure that have been reported in both animal and human studies of DCM. Furthermore, we provide a transcriptome-based catalogue of ECM genes that are associated with DCM, generated by using NCBI Gene Expression Omnibus database sets for DCM. Based on this in silico analysis, many novel ECM components involved in DCM are identified and discussed in this review. With the information gathered, we propose putative pathways of ECM adaptations in onset and progression of DCM.

  1. X-Linked Dilated Cardiomyopathy: A Cardiospecific Phenotype of Dystrophinopathy.

    PubMed

    Nakamura, Akinori

    2015-01-01

    X-linked dilated cardiomyopathy (XLDCM) is a distinct phenotype of dystrophinopathy characterized by preferential cardiac involvement without any overt skeletal myopathy. XLDCM is caused by mutations of the Duchenne muscular dystrophy (DMD) gene and results in lethal heart failure in individuals between 10 and 20 years. Patients with Becker muscular dystrophy, an allelic disorder, have a milder phenotype of skeletal muscle involvement compared to Duchenne muscular dystrophy (DMD) and sometimes present with dilated cardiomyopathy. The precise relationship between mutations in the DMD gene and cardiomyopathy remain unclear. However, some hypothetical mechanisms are being considered to be associated with the presence of some several dystrophin isoforms, certain reported mutations, and an unknown dystrophin-related pathophysiological mechanism. Recent therapy for Duchenne muscular dystrophy, the severe dystrophinopathy phenotype, appears promising, but the presence of XLDCM highlights the importance of focusing on cardiomyopathy while elucidating the pathomechanism and developing treatment.

  2. Biliary amylase and congenital choledochal dilatation.

    PubMed

    Davenport, M; Stringer, M D; Howard, E R

    1995-03-01

    The relationship between levels of biliary amylase measured at operation and clinical features was studied in a series of 55 children with congenital biliary dilatation (choledochal cyst) who presented between 1976 and 1993. There were 36 cystic and 19 fusiforms dilatations in the series. The most common modes of presentation were painless jaundice (n = 23) and pancreatitis (n = 22). Five infants presented with abnormal antenatal ultrasound examinations. Children with pancreatitis were older than those with painless jaundice (4.2 versus 1.5 years; P = .005), and a higher proportion had raised levels of biliary amylase (100% versus 44%; P < .0001). There was no difference in the age at presentation (P = .32), clinical mode of presentation (P = .3), or the level of biliary amylase (P = .25) between cystic and fusiform dilatations. A correlation was found between age at surgery and biliary amylase in the cystic (rs = 0.55; P = .001) but not in the fusiform group (P = .22). All infants with antenatal diagnoses were cystic dilatations. Choledochal cystic dilatations that were diagnosed antenatally did not have significant amylase reflux, suggesting that the aetiology of this subgroup is truly congenital. Children who present at a later age with pancreatitis invariably have high levels of biliary amylase, which is presumed to occur because of a common channel and reflux of biliary and pancreatic secretions.

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

    PubMed

    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. 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. PMID:24125260

  4. 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.

  5. 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

  6. Parallelized dilate algorithm for remote sensing image.

    PubMed

    Zhang, Suli; Hu, Haoran; Pan, Xin

    2014-01-01

    As an important algorithm, dilate algorithm can give us more connective view of a remote sensing image which has broken lines or objects. However, with the technological progress of satellite sensor, the resolution of remote sensing image has been increasing and its data quantities become very large. This would lead to the decrease of algorithm running speed or cannot obtain a result in limited memory or time. To solve this problem, our research proposed a parallelized dilate algorithm for remote sensing Image based on MPI and MP. Experiments show that our method runs faster than traditional single-process algorithm.

  7. Cystic dilation of the ventriculus terminalis

    PubMed Central

    Kawanishi, Masahiro; Tanaka, Hidekazu; Yokoyama, Kunio; Yamada, Makoto

    2016-01-01

    The ventriculus terminalis (VT) is a virtual cavity of the conus medullaris that appears during embryonic life. We presented a case with the cystic dilation of the ventriculus terminalis (CDVT) in a symptomatic patient. A 66-year-old female suffered from disturbance while walking evolving for the past 2 years. An MR image revealed a cystic dilatation of ventriculus terminalis. The patient experienced marked improvement of lower extremity strength by a fenestration of cyst and cyst-subarachnoid shunt. Treatment for asymptomatic patients seems to be the best conducted conservatively, whereas patients with focal neurological deficits seem to be best handled surgically. PMID:27695242

  8. Cystic dilation of the ventriculus terminalis

    PubMed Central

    Kawanishi, Masahiro; Tanaka, Hidekazu; Yokoyama, Kunio; Yamada, Makoto

    2016-01-01

    The ventriculus terminalis (VT) is a virtual cavity of the conus medullaris that appears during embryonic life. We presented a case with the cystic dilation of the ventriculus terminalis (CDVT) in a symptomatic patient. A 66-year-old female suffered from disturbance while walking evolving for the past 2 years. An MR image revealed a cystic dilatation of ventriculus terminalis. The patient experienced marked improvement of lower extremity strength by a fenestration of cyst and cyst-subarachnoid shunt. Treatment for asymptomatic patients seems to be the best conducted conservatively, whereas patients with focal neurological deficits seem to be best handled surgically.

  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. Management of achalasia: surgery or pneumatic dilation.

    PubMed

    Richter, Joel E; Boeckxstaens, Guy E

    2011-06-01

    Achalasia is an esophageal motility disorder of unknown cause, characterised by aperistalsis of the esophageal body and impaired lower esophageal sphincter relaxation. Patients present at all ages, primarily with dysphagia for solids/liquids and bland regurgitation. The diagnosis is suggested by barium esophagram or endoscopy and confirmed by esophageal manometry. Achalasia cannot be cured. Instead, our goal is to relieve symptoms, improve esophageal emptying and prevent the development of megaesophagus. The most successful therapies are pneumatic dilation and surgical myotomy. The advantages of pneumatic dilation include an outpatient procedure, minimal pain, return to work the next day, mild if any GERD, and can be performed in any age group and even during pregnancy. Pneumatic dilation does not hinder future myotomy, and all cost analyses find it less expensive than Heller myotomy. Laparoscopic myotomy with a partial fundoplication has the advantage of being a single procedure, dysphagia relief is longer at the cost of more troubling heartburn, and a myotomy may be more effective treatment in adolescents and younger adults, especially men. Over a two year horizon, the clinical success of pneumatic dilation and laparoscopic myotomy are comparable in a recent large European randomised trial. The prognosis for achalasia patients to return to near-normal swallowing and good quality of life are excellent, but few are "cured" with a single treatment and intermittent "touch up" procedures may be required. PMID:21303915

  11. Periodically correlated processes and their stationary dilations

    NASA Technical Reports Server (NTRS)

    Miamee, A. G.

    1988-01-01

    An explicit form for a stationary dilation for periodically correlated random processes is obtained. This is then used to give spectral conditions for a periodically correlated process to be non-deterministic, purely deterministic, minimal, and to have a positive angle between its past and future.

  12. 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...

  13. 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...

  14. 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

  15. 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 Section 884.4260 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... cervical dilator is a device designed to dilate (stretch open) the cervical os by cervical insertion of...

  16. 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 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED....4270 Vibratory cervical dilators. (a) Identification. A vibratory cervical dilator is a device...

  17. A Dilated Cardiomyopathy Revealing a Neuroblastoma: Which Link?

    PubMed

    Duhil de Bénazé, Gwenaelle; Iserin, Franck; Durand, Philippe; Schleiermacher, Gudrun; Orbach, Daniel

    2016-10-01

    Acute cardiac dysfunctions associated to neuroblastoma have rarely been reported. Cases already described are mainly related to high blood pressure, and rarely to an "acute catecholamine cardiomyopathy" more frequently found in adults with pheochromocytoma or secreting paraganglioma. We here report a case of an 8-month-old infant with severe acute cardiac failure with dilated cardiomyopathy and moderate ischemic myocardial signs, revealing a favorable histoprognosis neuroblastoma. After specific treatment, evolution was favorable, and cardiac function completely recovered. The association of reversible ischemic signs with high plasmatic level of catecholamines suggests the existence of a catecholamine-induced acute cardiac dysfunction which imitates a Tako-Tsubo syndrome in neuroblastoma.

  18. A Dilated Cardiomyopathy Revealing a Neuroblastoma: Which Link?

    PubMed

    Duhil de Bénazé, Gwenaelle; Iserin, Franck; Durand, Philippe; Schleiermacher, Gudrun; Orbach, Daniel

    2016-10-01

    Acute cardiac dysfunctions associated to neuroblastoma have rarely been reported. Cases already described are mainly related to high blood pressure, and rarely to an "acute catecholamine cardiomyopathy" more frequently found in adults with pheochromocytoma or secreting paraganglioma. We here report a case of an 8-month-old infant with severe acute cardiac failure with dilated cardiomyopathy and moderate ischemic myocardial signs, revealing a favorable histoprognosis neuroblastoma. After specific treatment, evolution was favorable, and cardiac function completely recovered. The association of reversible ischemic signs with high plasmatic level of catecholamines suggests the existence of a catecholamine-induced acute cardiac dysfunction which imitates a Tako-Tsubo syndrome in neuroblastoma. PMID:27571126

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

    PubMed

    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.

  20. Motor unit regulation of mammalian pharyngeal dilator muscle activity.

    PubMed Central

    van Lunteren, E; Dick, T E

    1989-01-01

    The present study examined the cellular regulation of one of the pharyngeal dilator muscles, the geniohyoid, by assessing its motor unit (MU) behavior in anesthetized cats. During spontaneous breathing, MU that (a) were active during inspiration only (I-MU) and (b) were active during both inspiration and expiration (I/E-MU) were identified. I-MU had a later inspiratory onset time and a shorter duration of inspiratory firing than did I/E-MU (P less than 0.002 and P less than 0.0001, respectively). I-MU were usually quiescent whereas I/E-MU were usually active during the last 20% of inspiration. I/E-MU fired more rapidly (P less than 0.00001) and for relatively longer periods of time (P less than 0.00001) during inspiration than during expiration. End-expiratory airway occlusion (preventing lung expansion during inspiration) augmented the inspiratory activity of both I-MU and I/E-MU. Conversely, end-expiratory airway occlusion reduced the absolute and relative firing durations (P less than 0.002 and P less than 0.00002, respectively) and the firing frequency (P less than 0.001) of I/E-MU activity during expiration. These results indicate that (a) the complex pattern of pharyngeal dilator muscle activity is due to the integrated activity of a heterogeneous group of MU, (b) changes in the degree to which pharyngeal dilator muscles are active result from combinations of MU recruitment/decruitment and modulations of the frequency and duration of MU firing, and (c) gating of lung-volume afferent information occurs during the respiratory cycle. PMID:2760202

  1. Safety of dilation in adults with eosinophilic esophagitis.

    PubMed

    Ally, M R; Dias, J; Veerappan, G R; Maydonovitch, C L; Wong, R K; Moawad, F J

    2013-04-01

    Esophageal dilation is an effective therapy for dysphagia in patients with stenosing eosinophilic esophagitis (EoE). Historically, there have been significant concerns of increased perforation rates when dilating EoE patients. More recent studies suggest that improved techniques and increased awareness have decreased complication rates. The aim of this study was to explore the safety of dilation in our population of EoE patients. A retrospective review of all adult EoE patients enrolled in a registry from 2006 to 2010 was performed. All patients who underwent esophageal dilation during this time period were identified and included in the analysis. Our hospital inpatient/outpatient medical records, radiology reports, and endoscopy reports were searched for evidence of any complication following dilation. Perforation, hemorrhage, and hospitalization were identified as a major complication, and chest pain was considered a minor complication. One hundred and ninety-six patients (41 years [12]; mean age [standard deviation], 80% white, 85% male) were identified. In this cohort, 54 patients (28%) underwent 66 total dilations (seven patients underwent two dilations, one patient underwent three dilations, and one patient underwent four dilations). Three dilation techniques were used (Maloney [24], Savary [29] and through-the-scope [13]). There were no major complications encountered. Chest pain was noted in two patients (4%). There were no endoscopic features (rings, furrows, plaques) associated with any complication. Type of dilator, size of dilator, number of prior dilations, and age of patient were also not associated with complications. Endoscopic dilation using a variety of dilators can be safely performed with minimal complications in patients with EoE.

  2. 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.

  3. 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}=∞ : ∞ : ∞.

  4. Habitual exercise may maintain endothelium-dependent dilation in overweight postmenopausal women.

    PubMed

    Sanders, Kate; Maresh, Carl M; Ballard, Kevin D; Creighton, Brent C; Pryor, J Luke; Kraemer, William J; Volek, Jeff S; Anderson, Jeff M

    2015-01-01

    Compared with their physically active peers, overweight sedentary postmenopausal women demonstrate impaired vascular endothelial function (VEF), substantially increasing the risk for cardiovascular disease (CVD). Habitual exercise is associated with improved VEF and reduced CVD risk. The purpose of this study was to compare brachial artery flow mediated dilation (FMD), a measure of VEF, in overweight, postmenopausal women who were physically active (EX: n = 17, BMI: 29.3 ± 3.11 kg/m2) or sedentary (CON: n = 8, BMI: 30.3 ± 3.6 kg/m2). Anthropomorphic measures were similar in both groups (P > .05). FMD was significantly greater in EX (10.24 ± 2.36%) versus CON (6.60 ± 2.18%) (P < .002). FMD was not significantly correlated with estimated VO2max (EX: r = .17, P = .52; CON: r = .20, P = .60) but was negatively associated with percent body fat in EX group (EX: r = -.48, P = .05; CON: r = .41, P = .31). These results are consistent with the positive effects of habitual exercise on VEF in overweight postmenopausal women.

  5. 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.

  6. 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.

  7. 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.

  8. Exploring Biological Motion Processing in Parkinson’s Disease Using Temporal Dilation

    PubMed Central

    Cao, Ruihua; Ye, Xing; Chen, Xingui; Zhang, Long; Chen, Xianwen; Tian, Yanghua; Hu, Panpan; Wang, Kai

    2015-01-01

    Biological motion (BM) perception is the compelling ability of the visual system to perceive complex animated movements effortlessly and promptly. A recent study has shown that BM can automatically lengthen perceived temporal duration independent of global configuration. The present study aimed mainly to investigate this temporal dilation effect of BM signals in Parkinson’s disease (PD) patients. We used the temporal dilation effect as an implicit measure of visual processing of BM. In all, 32 PD patients (under off-therapy conditions) and 32 healthy controls (HCs) participated in our study. In each trial, an upright BM sequence and an inverted BM sequence were presented within an interval in the center of the screen. We tested both canonical and scrambled BM sequences; the scrambled ones were generated by disturbing the global configuration of the canonical ones but preserving exactly the same local motion components. Observers were required to make a verbal two-alternative forced choice response to indicate which interval (the first or the second) appeared longer. Statistical analyses were conducted on the points of subjective equality (PSEs). We found that the temporal dilation effect was significantly reduced for PD patients compared with HCs in both canonical and scrambled BM conditions. Moreover, no temporal dilation effects of scrambled BM were shown in both early- and late-stage PD patients, while the temporal dilation effect of canonical BM was relatively preserved in the early stages. PMID:26381888

  9. 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.

  10. Superoxide dismutase restores endothelium-dependent arteriolar dilatation during acute infusion of nicotine.

    PubMed

    Mayhan, W G; Sharpe, G M

    1998-10-01

    We previously showed [Am. J. Physiol. 272 (Heart Circ. Physiol. 41): H2337-H2342, 1997] that nicotine impairs endothelium-dependent arteriolar dilatation. However, mechanisms that accounted for the effect of nicotine on endothelium-dependent vasodilatation were not examined. Thus the goal of this study was to examine the role of oxygen radicals in nicotine-induced impairment of arteriolar reactivity. We measured diameter of cheek pouch resistance arterioles (approximately 50 micrometer diameter) in response to endothelium-dependent (ACh and ADP) and -independent (nitroglycerin) agonists before and after infusion of vehicle or nicotine in the absence or presence of superoxide dismutase. ACh, ADP, and nitroglycerin produced dose-related dilatation of cheek pouch arterioles before infusion of vehicle or nicotine. Infusion of vehicle, in the absence or presence of superoxide dismutase (150 U/ml), did not alter endothelium-dependent or -independent arteriolar dilatation. In contrast, infusion of nicotine (2 microgram . kg-1 . min-1) impaired endothelium-dependent, but not -independent, arteriolar dilatation. In addition, the effect of nicotine on endothelium-dependent vasodilatation was reversed by topical application of superoxide dismutase. We suggest that nicotine impairs endothelium-dependent arteriolar dilatation via an increase in the synthesis/release of oxygen-derived free radicals.

  11. Is endoscopic papillary balloon dilatation really a risk factor for post-ERCP pancreatitis?

    PubMed

    Fujisawa, Toshio; Kagawa, Koichi; Hisatomi, Kantaro; Kubota, Kensuke; Nakajima, Atsushi; Matsuhashi, Nobuyuki

    2016-07-14

    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

  12. 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

  13. Prediction of positive and negative elastic dilatancy in 2D and 3D liquid foams

    NASA Astrophysics Data System (ADS)

    Rognon, P.; Molino, F.; Gay, C.

    2010-05-01

    Liquid foams have been observed to behave like immersed granular materials in at least one respect: deformation tends to raise their liquid contents, a phenomenon called dilatancy. While experimental observations evidenced the effect of a continuous deformation rate (dynamic dilatancy), we present a geometrical interpretation of both main contributions to elastic dilatancy (during elastic deformation) in foams squeezed between two solid plates (2D GG foams), which contain pseudo Plateau borders along the plates, and in 3D foams. The positive contribution is related to the increase in total Plateau border length while the negative contribution reflects the increase in total surface area of the foam. In 2D, we show that the negative dilatancy predicted by Weaire and Hutzler (Philos. Mag., 83 (2003) 2747) at very low liquid fractions is specific to ideal 2D foams (with no glass plates). In 3D, we predict that dilatancy should be positive at low liquid fractions (below 1%) and negative at moderate liquid fractions (above 4%).

  14. Analyzing gene expression profiles in dilated cardiomyopathy via bioinformatics methods

    PubMed Central

    Wang, Liming; Zhu, L.; Luan, R.; Wang, L.; Fu, J.; Wang, X.; Sui, L.

    2016-01-01

    Dilated cardiomyopathy (DCM) is characterized by ventricular dilatation, and it is a common cause of heart failure and cardiac transplantation. This study aimed to explore potential DCM-related genes and their underlying regulatory mechanism using methods of bioinformatics. The gene expression profiles of GSE3586 were downloaded from Gene Expression Omnibus database, including 15 normal samples and 13 DCM samples. The differentially expressed genes (DEGs) were identified between normal and DCM samples using Limma package in R language. Pathway enrichment analysis of DEGs was then performed. Meanwhile, the potential transcription factors (TFs) and microRNAs (miRNAs) of these DEGs were predicted based on their binding sequences. In addition, DEGs were mapped to the cMap database to find the potential small molecule drugs. A total of 4777 genes were identified as DEGs by comparing gene expression profiles between DCM and control samples. DEGs were significantly enriched in 26 pathways, such as lymphocyte TarBase pathway and androgen receptor signaling pathway. Furthermore, potential TFs (SP1, LEF1, and NFAT) were identified, as well as potential miRNAs (miR-9, miR-200 family, and miR-30 family). Additionally, small molecules like isoflupredone and trihexyphenidyl were found to be potential therapeutic drugs for DCM. The identified DEGs (PRSS12 and FOXG1), potential TFs, as well as potential miRNAs, might be involved in DCM. PMID:27737314

  15. Plummer-Vinson syndrome successfully treated by endoscopic dilatation.

    PubMed

    Enomoto, Masaru; Kohmoto, Madoka; Arafa, Usama Ahmed; Shiba, Masatsugu; Watanabe, Toshio; Tominaga, Kazunari; Fujiwara, Yasuhiro; Saeki, Yoshihiko; Higuchi, Kazuhide; Nishiguchi, Shuhei; Shiomi, Susumu; Osugi, Haruji; Kinoshita, Hiroaki; Arakawa, Tetsuo

    2007-12-01

    Plummer-Vinson (Paterson-Brown-Kelly) syndrome is uncommon nowadays. Although iron repletion improves its symptoms, endoscopic dilatation of associated esophageal webs is sometimes required. The case is described of a 69-year-old woman with Plummer-Vinson syndrome who was successfully treated by endoscopic bougienage. The patient had a longstanding history of anemia and slowly progressive dysphagia of solid food. Laboratory data on admission showed iron deficiency anemia (red blood cell count 402 x 10(4)/microL, hemoglobin 6.8 g/dL, serum iron 8 microg/dL, and serum ferritin 2.4 ng/mL). Radiographic esophagography revealed two circumferential webs at the level of the cervical esophagus. Upper gastrointestinal endoscopy showed a severe upper esophageal stricture caused by a smooth mucosal diaphragm. The patient was prescribed 40 mg of intravenous iron supplements daily for 30 days; her anemia improved but the dysphagia did not. Endoscopic bougienage was performed with the use of Celestin dilators of serially increasing diameters. The webs were easily disrupted without complications. The patient's dysphagia resolved shortly after the treatment and did not recur. This experience indicates that endoscopic bougienage is safe, effective, and relatively easy to perform in patients with severe esophageal stenosis.

  16. Porous media modeling and micro-structurally motivated material moduli determination via the micro-dilatation theory

    NASA Astrophysics Data System (ADS)

    Jeong, J.; Ramézani, H.; Sardini, P.; Kondo, D.; Ponson, L.; Siitari-Kauppi, M.

    2015-07-01

    In the present contribution, the porous material modeling and micro-structural material parameters determination are scrutinized via the micro-dilatation theory. The main goal is to take advantage of the micro-dilatation theory which belongs to the generalized continuum media. In the first stage, the thermodynamic laws are entirely revised to reach the energy balance relation using three variables, deformation, porosity change and its gradient underlying the porous media as described in the micro-dilatation theory or so-called void elasticity. Two experiments over cement mortar specimens are performed in order to highlight the material parameters related to the pore structure. The shrinkage due to CO2 carbonation, porosity and its gradient are calculated. The extracted values are verified via 14C-PMMA radiographic image method. The modeling of swelling phenomenon of Delayed Ettringite Formation (DEF) is studied later on. This issue is performed via the crystallization pressure application using the micro-dilatation theory.

  17. Refractory dilated cardiomyopathy associated with metastatic neuroblastoma.

    PubMed

    Carlson, Peter; Jefferies, John L; Kearney, Debra; Russell, Heidi

    2010-10-01

    A 2-year-old African American male presented with heart failure and an abdominal mass. Computerized tomography (CT) scan revealed a 7 cm adrenal lesion, confirmed as poorly differentiated neuroblastoma (NB). CT and meta-iodobenzoguanidine (MIBG) scans identified multiple metastases, but cardiac MIBG imaging was absent. Cardiac ejection fraction (EF) was 8% with 7% shortening fraction. The patient underwent six cycles of chemotherapy and investigational immunotherapy. Cardiac function improved to 26% EF. However, the tumor proved unresponsive to treatment. The patient died from stage IV congestive heart failure (CHF) and progressive NB. Autopsy confirmed dilated cardiomyopathy with endocardial fibroelastosis.

  18. Dilated cardiomyopathy associated with toluene abuse.

    PubMed

    Vural, Mutlu; Ogel, Kultegin

    2006-01-01

    The use of paint thinner and glue to achieve an euphoric state has been associated with serious social and health problems in children and young adults. We present the case of a 21-year-old man with dilated cardiomyopathy occurring following abuse of paint thinner and glue containing toluene as main compound. After cessation of toluene abuse, the patient recovered rapidly and completely. Because of the increasing prevalence of toluene abuse, harmful effects of this volatile agent on the heart are also discussed. PMID:16479101

  19. Prospective randomized comparison of progressive dilational vs forceps dilational percutaneous tracheostomy.

    PubMed

    Kaiser, E; Cantais, E; Goutorbe, P; Salinier, L; Palmier, B

    2006-02-01

    This trial prospectively compares two methods of percutaneous tracheostomy, both routinely used in ICU: the Ciaglia progressive dilational tracheostomy and the Griggs forceps dilational tracheostomy. One hundred patients were randomized using a single-blinded envelope method to receive progressive or forceps percutaneous tracheostomy performed at the bedside. Operative time, the occurrence of hypoxaemia or hypercapnia and complications were recorded. The progressive technique took longer than the forceps technique (median 7 (range 2-26) vs. 4 (1-16) minutes, P = 0.0005). Hypercapnia occurred in both groups but was more marked with the progressive technique (56 (16) vs. 49 (13) mmHg, P = 0.0082). Minor complications (minor bleeding, transient hypoxaemia, damage to posterior tracheal wall without emphysema) were also more frequent with the progressive technique (31 vs. 9 complications, P < 0.0001). Six major complications occurred with the progressive technique, none with the forceps technique (P = 0.0085): tension pneumothorax, posterior tracheal wall injury with subcutaneous emphysema, loss of airway with hypoxaemia, loss of stoma with impossible re-catheterization, and two conversions to another technique. In conclusion, progressive dilational tracheostomy took longer, caused more hypercapnia and more minor and major difficulties than forceps dilational tracheostomy. PMID:16494150

  20. 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.

  1. Visual recovery using small dilating eye drops.

    PubMed

    Gray, R H; Franklin, S J; Reeves, B C

    1992-08-01

    It is well established that reduced size dilating eye drops of 1% tropicamide and 10% phenylephrine (micro drops) are effective for clinical purposes. Excellent pupil dilatation (mydriasis) is achieved and pupil constriction does not occur in response to light. In this study, the effect of micro drops of 1% tropicamide on distance and near visual recovery was compared with standard drops in a group of 20 healthy volunteers. For each person studied, one eye was selected at random to be tested first with the standard drop size, and then after a minimum of one week, the same eye was again tested using a drop of the same drug one fifth standard size. An iris photograph, Snellen visual acuity at 6 m, and reading visual acuity was obtained for each test procedure: before drop instillation and at 30 min, 1, 2 and 4 h after drug instillation. Use of the micro drops caused a small but statistically significant improvement in the rate of recovery of distance and near visual acuity. These findings, allied to the known beneficial effects of reduced systemic absorption using micro drops, lend further weight to the argument that mydriasis may be achieved more safely, with fewer side effects, and with earlier return of normal vision when reduced size drops are used. It is hoped that practical micro drop dispensers will be developed.

  2. Right ventricular filling in dilated cardiomyopathy.

    PubMed Central

    Fujimoto, S.; Parker, K. H.; Gibson, D. G.

    1995-01-01

    PURPOSE--To assess right ventricular filling in dilated cardiomyopathy. PATIENTS--32 patients with dilated cardiomyopathy and 24 healthy controls. METHODS--Stroke distances were measured by pulsed Doppler echocardiography at left ventricular outflow and left and right ventricular inflow. The inflow tract dimensions of both ventricles and the outflow tract dimension of the left ventricle were measured from two dimensional images. Right and left sided atrioventricular (AV) ring excursions were measured by M mode echocardiography at the tricuspid and mitral rings. Stroke volume was derived as stroke distance multiplied by left ventricular outflow tract area. Total stroke distances were calculated as the sum of AV valve Doppler stroke distances and ring excursion. The effective orifice areas of the two AV valves were thus defined as stroke volumes divided by total stroke distance. RESULTS--Total tricuspid stroke distance was normally less than mitral (6.0 (1.7) v 7.6 (1.7) cm, P < 0.05), implying that effective orifice area of the tricuspid valve was consistently greater (6.6 (1.6) v 4.5 (0.8) cm2, P < 0.01). Total tricuspid ring excursion was normally more than mitral (2.30 (0.30) v 1.62 (0.22) cm, P < 0.01). Total tricuspid stroke distance in dilated cardiomyopathy was also less than mitral (7.8 (2.4) v 9.7 (2.8) cm, P < 0.05). Tricuspid stroke distance was significantly increased in patients with dilated cardiomyopathy compared with that in healthy controls (P < 0.05 v controls), though stroke volume was much smaller (26 (10) v 63 (11) ml, P < 0.01) so that tricuspid effective orifice area was reduced to less than half normal (2.7 (1.2) cm2, P < 0.01). Total tricuspid ring long axis excursion was more than mitral (1.37 (0.6) v 0.74 (0.21) cm, P < 0.01). Right ventricular end diastolic inflow dimension was increased compared with that in healthy controls (3.9 (0.7) v 2.8 (0.5) cm, P < 0.01), correlating inversely with tricuspid effective orifice area (r = -0.71, P

  3. Endoscopic papillary balloon dilation: revival of the old technique.

    PubMed

    Jeong, Seung Uk; Moon, Sung-Hoon; Kim, Myung-Hwan

    2013-12-01

    Radiologists first described the removal of bile duct stones using balloon dilation in the early 1980s. Recently, there has been renewed interest in endoscopic balloon dilation with a small balloon to avoid the complications of endoscopic sphincterotomy (EST) in young patients undergoing laparoscopic cholecystectomy. However, there is a disparity in using endoscopic balloon papillary dilation (EPBD) between the East and the West, depending on the origin of the studies. In the early 2000s, EST followed by endoscopic balloon dilation with a large balloon was introduced to treat large or difficult biliary stones. Endoscopic balloon dilation with a large balloon has generally been recognized as an effective and safe method, unlike EPBD. However, fatal complications have occurred in patients with endoscopic papillary large balloon dilation (EPLBD). The safety of endoscopic balloon dilation is still a debatable issue. Moreover, guidelines of indications and techniques have not been established in performing endoscopic balloon dilation with a small balloon or a large balloon. In this article, we discuss the issue of conventional and large balloon endoscopic dilation. We also suggest the indications and optimal techniques of EPBD and EPLBD.

  4. 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.

  5. 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.

  6. Anti-tumor necrosis factor-α therapy and changes of flow-mediated vasodilatation in psoriatic and rheumatoid arthritis patients.

    PubMed

    Mazzoccoli, Gianluigi; Notarsanto, Incoronata; de Pinto, Gennaro Davide; Dagostino, Mariangela Pia; De Cata, Angelo; D'Alessandro, Giuseppe; Tarquini, Roberto; Vendemiale, Gianluigi

    2010-12-01

    For a long time, the endothelial covering of the vessels has been considered an inert surface. On the contrary, the endothelial cells are active and dynamic elements in the interaction between blood and tissues. The control of the vessel basal tone is obtained by the complex balance between the relaxing and contracting endothelial factors. Previous clinical studies show that patients suffering from rheumatoid arthritis and other autoimmune rheumatologic pathologies are at high risk of death being prematurely affected by atherosclerosis and cardiovascular diseases. Blocking tumor necrosis factor (TNF)-α by biological drugs improves the endothelial function. The aim of our study was to evaluate the effects of two anti-TNF-α drugs (infliximab and etanercept) on the endothelial function by evaluating the flow-mediated dilatation (FMD), which was measured in the brachial artery before and after treatment and after 8-12 weeks. We enrolled 36 patients (average age 52 ± 9.8 years, 12 men and 24 women), 25 of them were affected by rheumatoid arthritis (RA) and 11 were affected by psoriatic arthritis (PsA) and they were divided into three groups: 10 patients were treated with etanercept, 13 patients were treated with infliximab, 13 patients were treated with DMARDs. We measured the common carotid intimal-medial thickness (ccIMT) and the endothelial function was evaluated by FMD measurement in the brachial artery, before treatment, 1 h after the beginning of treatment and after 8-12 weeks. No statistically significant difference between the three groups was found for the ultrasonographic evaluation of the carotid IMT. On the contrary, the differences between FMD values before and after the treatment in the patients treated with etanercept (13.1 ± 0.01 vs. 18.8 ± 0.01%, p < 0.01) and in the patients treated with infliximab (11.8 ± 0.09 vs. 16.7 ± 0.09%, p < 0.01) were statistically significant. Long-term evaluation for infliximab and etanercept was

  7. 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

    2016-01-01

    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. PMID:26947561

  8. Impact of non-random vibrations in Mössbauer rotor experiments testing time dilation

    NASA Astrophysics Data System (ADS)

    Friedman, Y.; Nowik, I.; Felner, I.; Steiner, J. M.; Yudkin, E.; Livshitz, S.; Wille, H.-C.; Wortmann, G.; Arogeti, S.; Levy, R.; Chumakov, A. I.; Rüffer, R.

    2016-06-01

    All experiments testing time dilation by measuring the spectral shift of a rotating Mössbauer absorber assume that vibrations do not affect the spectral shift because of their purely random nature and claim that the observed shift is due to time dilation only. Our recent experiment using the Synchrotron Mössbauer Source at ESRF revealed, however, a shift due to the non-random periodic vibration patterns caused by the rotor/bearing system. These patterns fit the predictions of the Jeffcott model for such a system with non-zero eccentricity. We have calculated this shift due to the non-random vibrations and the resulting relative shift between two states when the acceleration of the absorber is anti-parallel and parallel to the source. This relative shift exhibits the same behavior as the observed relative shift. Hence, the effect of the spectral shift due to vibrations cannot be ignored in any Mössbauer rotor experiments for testing time dilation. Recommendations for improvement of future rotor experiments testing time dilation are presented.

  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. Genetics of Human and Canine Dilated Cardiomyopathy

    PubMed Central

    Simpson, Siobhan; Edwards, Jennifer; Ferguson-Mignan, Thomas F. N.; Cobb, Malcolm; Mongan, Nigel P.; Rutland, Catrin S.

    2015-01-01

    Cardiovascular disease is a leading cause of death in both humans and dogs. Dilated cardiomyopathy (DCM) accounts for a large number of these cases, reported to be the third most common form of cardiac disease in humans and the second most common in dogs. In human studies of DCM there are more than 50 genetic loci associated with the disease. Despite canine DCM having similar disease progression to human DCM studies into the genetic basis of canine DCM lag far behind those of human DCM. In this review the aetiology, epidemiology, and clinical characteristics of canine DCM are examined, along with highlighting possible different subtypes of canine DCM and their potential relevance to human DCM. Finally the current position of genetic research into canine and human DCM, including the genetic loci, is identified and the reasons many studies may have failed to find a genetic association with canine DCM are reviewed. PMID:26266250

  11. Dilatant hardening of fluid-saturated sandstone

    NASA Astrophysics Data System (ADS)

    Makhnenko, Roman Y.; Labuz, Joseph F.

    2015-02-01

    The presence of pore fluid in rock affects both the elastic and inelastic deformation processes, yet laboratory testing is typically performed on dry material even though in situ the rock is often saturated. Techniques were developed for testing fluid-saturated porous rock under the limiting conditions of drained, undrained, and unjacketed response. Confined compression experiments, both conventional triaxial and plane strain, were performed on water-saturated Berea sandstone to investigate poroelastic and inelastic behavior. Measured drained response was used to calibrate an elasto-plastic constitutive model that predicts undrained inelastic deformation. The experimental data show good agreement with the model: dilatant hardening in undrained triaxial and plane strain compression tests under constant mean stress was predicted and observed.

  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. 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…

  14. Psoriasis and dilated cardiomyopathy: coincidence or associated diseases?

    PubMed

    Eliakim-Raz, Noa; Shuvy, Mony; Lotan, Chaim; Planer, David

    2008-01-01

    Psoriasis is a common immune-mediated disease which affects 1-3% of the population. The etiology of psoriasis is unknown. Idiopathic dilated cardiomyopathy is probably the end result of a variety of toxic, metabolic or infectious agents. During a computerized search for cardiomyopathy among all patients hospitalized with psoriasis in the Hadassah University Hospital since 1980 we found an increased prevalence of cardiomyopathy, and specifically dilated cardiomyopathy. We present 4 patients who suffer from both conditions. In accordance with previous data, an association between preexisting psoriasis and dilated cardiomyopathy is suggested. We suggest that the genetic risk factors of dilated cardiomyopathy are shared by psoriasis, and more specifically psoriatic arthritis. Alternatively, the immune reaction that is triggered in dilated cardiomyopathy leading to the progression of the disease might be enhanced in patients with psoriasis or psoriatic arthritis. Chronic inflammation and persistent secretion of proinflammatory cytokines may be considered a potential pathway, triggering the initiation and progression of dilated cardiomyopathy in psoriatic patients. Further investigation of the genetic and immune risk factors involved in dilated cardiomyopathy and in psoriasis may lead to a better understanding of the pathogenesis and treatment of dilated cardiomyopathy.

  15. Genetics Home Reference: DMD-associated dilated cardiomyopathy

    MedlinePlus

    ... 2344-7. Review. Citation on PubMed Berko BA, Swift M. X-linked dilated cardiomyopathy. N Engl J ... Gelb B, Zhu XM, Chamberlain JS, McCabe ER, Swift M. X-linked dilated cardiomyopathy. Molecular genetic evidence ...

  16. Dilated aortic root and severe aortic regurgitation causing dilated cardiomyopathy in classic Ehlers-Danlos syndrome.

    PubMed

    Zainal, Abir; Hamad, Mahmoud Nidal; Naqvi, Syed Yaseen

    2016-01-01

    Ehlers-Danlos syndrome (EDS) is a group of heritable disorders characterised by vast clinical heterogeneity ranging from the classic constellation of symptoms including skin hyperextensibility, joint hypermobility and skin fragility to the exceedingly critical consequences of arterial rupture and visceral perforation. We describe the case of a 65-year-old male with a history of classic EDS who reported of dyspnoea on exertion, orthopnoea, fatigue and palpitations. He was found to have dilated cardiomyopathy with an ejection fraction of 35%, aortic root dilation and severe aortic valve regurgitation. The authors intend to draw attention to the rare cardiac manifestations of this condition and the therapeutic challenges involved in managing such patients. PMID:27413024

  17. 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

  18. [Cervical incompetence after previous cervical dilatation and curettage (author's transl)].

    PubMed

    Grünberger, W; Riss, P

    1979-07-15

    Out of a total of 3502 deliveries over a period of two years 254 patients (7.25%) had a surgical closure of the cervix according to Shirodkar because of cervical incompetence. All 3502 records were reviewed with regard to previous obstetrical and gynecological history. In the group with Shirodkar operation the percentage of women with a history of spontaneous or induced abortions was almost twice as high as in the comparison group. The reason for the development of cervical incompetence could be a trauma to the endocervix due to mechanical dilatation since diagnostic or therapeutic dilatation and curettage was found five times more often in women with Shirodkar operation than in patients without cervical incompetence. The results show that dilatation and curettage for any indication should be performed as carefully as possible, especially in younger women of childbearing age. Chemical dilatation of the endocervix--for example with prostaglandins--seems to be preferable to mechanical dilatation.

  19. Cylindrical dilatation of the choledochus: a special type of congenital bile duct dilatation.

    PubMed

    Todani, T; Watanabe, Y; Fujii, T; Toki, A; Uemura, S; Koike, Y

    1985-11-01

    Cylindrical dilatation of the choledochus develops in 20% of patients with congenital bile duct dilatation and usually has acute-angled unions of the pancreatobiliary ductal system. Symptoms generally develop in patients over 1 year of age. The patients frequently complain of abdominal pain, vomiting, and fever as in those with acute pancreatitis. Ultrasonography and infusion cholangiography are the most useful tools in making a correct diagnosis. A high amylase level in the bile caused by the refluxing of pancreatic juice through anomalous ductal unions is commonly observed. This is responsible for biliary perforation in infancy and possibly carcinoma arising in the bile duct. The amylase concentration in the serum at the time of epigastric pain often is high, which leads to the diagnosis of acute pancreatitis. However, evidence of pancreatic inflammation is seldom noted. Accordingly, amylase in the bile may enter the circulating blood through the denuded epithelium or sinusoids of the liver. Excision of the whole extrahepatic duct along with hepaticoenterostomy would be essential for the treatment of cylindrical dilatation of the bile duct, especially when an anomalous ductal union is present.

  20. 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

  1. 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.

  2. Inherited infantile dilated cardiomyopathy in dogs: genetic, clinical, biochemical, and morphologic findings.

    PubMed

    Alroy, J; Rush, J E; Freeman, L; Amarendhra Kumar, M S; Karuri, A; Chase, K; Sarkar, S

    2000-11-01

    Dilated cardiomyopathy, a lethal disease characterized by left ventricular dilation and systolic dysfunction, is relatively common in humans and other mammals. Idiopathic dilated cardiomyopathy (IDCM) is a primary myocardial disease of unknown cause and can be a familial disorder. This report describes autosomal recessive IDCM in dogs. It occurs in Portuguese Water Dog (PWD) pups and is manifested by acute, vague clinical signs and sudden death. Affected pups have progressive reduction of fractional shortening that can be demonstrated by echocardiography prior to the development of clinical signs. Furthermore, these pups have low plasma taurine levels when consuming certain diets. Affected pups had dilation of the left ventricle and alterations in the sarcomere appearance, while immunohistochemical and biochemical studies demonstrate an increase in desmin, a cytoskeleton protein. The clinical and morphologic findings of IDCM in PWDs are distinct from those reported in adult IDCM. Finally, the clinical and echocardiographic manifestations were reversible in some pups following oral taurine supplementation for 2 months. These results suggest that IDCM in PWDs is correlated with low plasma taurine levels.

  3. 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

  4. Increased flow precedes remote arteriolar dilations for some microapplied agonists.

    PubMed

    Frame, M D

    2000-04-01

    This study asks which occurs first in time for remote responses: a dilation or a remote change in flow. Arteriolar diameter (approximately 20 microm) and fluorescently labeled red blood cell (RBC) velocity were measured in the cremaster muscle of anesthetized (pentobarbital sodium, 70 mg/kg) hamsters (n = 51). Arterioles were locally stimulated for 60 s with micropipette-applied 10 microg/ml LM-609 (alpha(v)beta(3)-integrin agonist), 10(-3) M adenosine, or 10(-3) M 3-morpholinosydnonimine (SIN-1, nitric oxide donor) as remote response agonists or with 10(-3) M papaverine, which dilates only locally. Observations were made at a remote site 1,200 microm upstream. With LM-609 or adenosine, the RBC velocity increased first (within 5 s), and the remote dilation followed 5-7 s later. N-nitro-L-arginine (100 microM) blocked the LM-609 (100%) and adenosine (60%) remote dilations. SIN-1 induced a concurrent remote dilation and decrease in RBC velocity (approximately 10 s), suggesting the primary signal was to dilate. Papaverine had no remote effects. This study suggests that, although remote responses to some agonists are induced by primary signals to dilate, additionally, network changes in flow can stimulate extensive remote changes in diameter.

  5. Predictors for frequent esophageal dilations of benign peptic strictures.

    PubMed

    Agnew, S R; Pandya, S P; Reynolds, R P; Preiksaitis, H G

    1996-05-01

    Recurrence of esophageal peptic stricture necessitating repeated dilation treatments remains a problem for many patients despite optimal acid suppressive therapy. The factors associated with frequent relapses are poorly understood. We studied retrospectively a population of 58 patients with benign peptic strictures and dysphagia treated by esophageal dilation and followed for 66.5 +/- 6.7 months. Data was collected for age, sex, heartburn, weight loss, esophagitis, Barrett's esophagus, number of dilation treatments during the first year of follow-up, frequency and number of subsequent dilation treatments, type of dilator used, and history of other concurrent treatments. Patients who lacked heartburn (P = 0.007) or who reported a history of weight loss (P = 0.006) at the time of their initial presentation required more frequent dilations during the first year of follow-up. The mean number of dilations in year 1 was 6.2 +/- 0.9 for patients lacking heartburn versus 3.2 +/- 0.5 for patients with heartburn (P = 0.004), and 9.0 +/- 1.8 for patients who reported weight loss versus 4.1 +/- 0.5 (P = 0.006) for those who did not. The patients requiring frequent treatment during their first year also required frequent subsequent dilations because of stricture recurrence (P < 0.0001). We did not demonstrate any relationship between the other factors studied and treatment frequency. These observations suggest that patients who require frequent retreatment for recurrent peptic stricture are more likely to provide a history of weight loss and less likely to complain of heartburn at initial presentation. The pattern of frequent repeat dilation for recurrent peptic strictures is established during the first year of follow-up.

  6. [Dilated cardiomyopathy induced by ectopic atrial tachycardia].

    PubMed

    Velázquez Rodríguez, E; Martínez Enríquez, A

    2000-01-01

    The deleterious effect of chronic or incessant supraventricular tachycardia on ventricular function is well-known and it has been demonstrated than can ultimately lead to dilated cardiomyopathy if unrecognized. Any variety of supraventricular tachycardia with chronic evolution may lead to left ventricular dysfunction, ectopic atrial tachycardia because of its persistent nature, often incessant and poorly responsive to antiarrhythmic drugs is a frequent cause of reversible congestive heart failure in patients without other demonstrable organic heart disease. Five patients (aged 14 to 52 years) were referred with symptoms of heart failure, NYHA functional class II (one patient), class III (one patient) and class IV (3 patients) associated with an incessant ectopic atrial tachycardia. Four patients underwent radiofrequency catheter ablation of the ectopic focus and one patient was treated with amiodarone. All patients were successfully treated and the echocardiographic assessment of left ventricular function indicated regression of the cardiomyopathy picture with recovery of systolic function, (mean left ventricular ejection fraction 39.2 +/- 6.1% before vs mean 62.4 +/- 4.8% after (p < 0.01). The clinical and echocardiographic picture of cardiomyopathy induced by incessant ectopic atrial tachycardia is reversible after successful treatment. This stresses the necessity of recognizing such arrhythmia as cause of primary heart failure. PMID:10959459

  7. Inelastic compaction, dilation and hysteresis of sandstones under hydrostatic conditions

    NASA Astrophysics Data System (ADS)

    Shalev, Eyal; Lyakhovsky, Vladimir; Ougier-Simonin, Audrey; Hamiel, Yariv; Zhu, Wenlu

    2014-05-01

    Sandstones display non-linear and inelastic behaviour such as hysteresis when subjected to cyclic loading. We present three hydrostatic compaction experiments with multiple loading-unloading cycles on Berea and Darley Dale sandstones and explain their hysteretic behaviour using non-linear inelastic compaction and dilation. Each experiment included eight to nine loading-unloading cycles with increasing maximum pressure in each subsequent cycle. Different pressure-volumetric strain relations during loading and unloading were observed. During the first cycles, under relatively low pressures, not all of the volumetric strain is recovered at the end of each cycle whereas at the last cycles, under relatively high pressures, the strain is recovered and the pressure-volumetric strain hysteresis loops are closed. The observed pressure-volumetric strain relations are non-linear and the effective bulk modulus of the sandstones changes between cycles. Observations are modelled with two inelastic deformation processes: irreversible compaction caused by changes in grain packing and recoverable compaction associated with grain contact adhesion, frictional sliding on grains or frictional sliding on cracks. The irreversible compaction is suggested to reflect rearrangement of grains into a more compact mode as the maximum pressure increases. Our model describes the `inelastic compaction envelope' in which sandstone sample will follow during hydrostatic loading. Irreversible compaction occurs when pressure is greater than a threshold value defined by the `inelastic compaction envelope'.

  8. Unilateral pupillary dilatation following septoplasty: cause for concern?

    PubMed

    Shakeel, Muhammad; Trinidade, Aaron; Khan, Imran; Johnston, Graham; Hussain, Akhtar

    2013-07-01

    We report and explain unilateral pupillary dilatation following routine septoplasty and trimming of inferior turbinates. The unilateral pupillary dilatation was caused by inadvertent instillation of sympathomimetic, (xylometazoline hydrochloride) in the eye during preparation for nasal surgery. The effect was short-lived and the patient made a full recovery. Unilateral pupillary dilatation after sinonasal surgery can be alarming due to the possibility of injury to the globe and intracranial haemorrhage but can also be explained by the mydriatic effect of the sympathomimetic nasal drops and sprays used to decongest the nose. Such possibility should be borne in mind and would help to explain and reduce the anxiety and avoid unnecessary investigations. PMID:23823962

  9. Autoimmunity to alpha myosin in a subset of patients with idiopathic dilated cardiomyopathy.

    PubMed Central

    Goldman, J. H.; Keeling, P. J.; Warraich, R. S.; Baig, M. K.; Redwood, S. R.; Dalla Libera, L.; Sanderson, J. E.; Caforio, A. L.; McKenna, W. J.

    1995-01-01

    OBJECTIVE--To use an enzyme linked immunoassay (ELISA) technique to assess frequency and disease specificity of anti-alpha-myosin antibodies in patients with dilated cardiomyopathy and their relatives. METHODS--Evaluation was performed on sera (dilution 1/320) from 123 consecutive patients with dilated cardiomyopathy (WHO criteria) (age 42 (SD 14) years), 252 of their relatives (35 (17) years), 203 healthy controls (45 (16) years), and 92 patients with ischaemic heart disease (63 (11) years). RESULTS--Abnormal antibody levels were commoner in patients with dilated cardiomyopathy (25, 20%) than in ischaemic heart disease (4, 4%), or normal controls (4, 2%, P = 0.001). Forty one (16%) of the relatives had abnormal results compared to the controls (4, 2%, P < 0.001) and antibodies were detected in 20 (38%) of pedigrees. Relatives from non-familial kindreds had higher antibody levels than those with familial disease (P << 0.001), and higher antibody levels were identified in 53 relatives of probands who had abnormal results compared to 116 relatives for whom the proband had a normal result (0.37 (SEM 0.02) v 0.22 (0.01); P < 0.001). CONCLUSIONS--The finding of anti-alpha-myosin antibodies in 20% of patients with dilated cardiomyopathy, in 16% of their asymptomatic relatives, and in 38% of families (particularly those with non-familial disease and where proband also had an abnormal result) provides additional evidence for autoimmunity against alpha myosin in a subset of patients. PMID:8541162

  10. 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.

  11. [Laminaria--a modern cervix dilatation method with more than a 100-year history].

    PubMed

    Jonasson, A

    1984-06-01

    The author surveys the history and present use of laminaria tents for cervix dilatation, their application for 1st and 2nd trimester induced abortions, combined use with other agents (prostaglandin F2alpha (PGF2a) and oxytocin), and complications. Laminaria tents are derived from 2 kinds of seaweed. They were 1st used in the US and Japan, and have been used in Sweden and Denmark for 50-60 years. Due to its hygroscopic quality, laminaria gradually dilates the cervix up to 12-13 mm, 15-16 hours after insertion. In a US study of 15,438 patients undergoing vacuum extraction abortion in the 1st trimester, the use of laminaria was found to result in 1/5 fewer complications than the Hegar method (which led to frequent injuries of the cervix musculature and sustained dilatation 6 weeks later). Combined use of laminaria 12-16 hours before injection of PGF2a reduced abortion time from 17.2 to 9.1 hours in 2nd trimester abortions. Combined use of intraamniotic PGF2a, iv oxytocin, and laminaria also reduced induced abortion time. Dilatation with laminaria 8-12 hours before injection of prostaglandin E2 (PGE2) in doses of .5 mg/4 hr or 1.0 mg/8 hr shortened abortion time considerably. The use of PGE2 also produced fewer gastrointestinal side effects than PGF2a. Application of laminaria the day before abortion inducement was found to significantly increase Bishop score values and produced a 75%-87% success rate even with an initial Bishop score of less than 5. Complications in the use of laminaria include difficulty of tent removal, cramps, and menstruation-like symptoms in 8-9% of patients. Laminaria is recommended for nontraumatic cervix dilatation because of reduced abortion time, minimal blood loss, high patient tolerance levels, and relatively low incidence of uterus perforation or cervix lacerations. PMID:6565007

  12. Serological and molecular evidence of enterovirus infection in patients with end-stage dilated cardiomyopathy.

    PubMed Central

    Muir, P.; Nicholson, F.; Illavia, S. J.; McNeil, T. S.; Ajetunmobi, J. F.; Dunn, H.; Starkey, W. G.; Reetoo, K. N.; Cary, N. R.; Parameshwar, J.; Banatvala, J. E.

    1996-01-01

    OBJECTIVE: To study the relative diagnostic value of enterovirus-specific molecular biological and serological assays in patients with end-stage dilated cardiomyopathy, and to investigate the possible role of other cardiotropic viruses in dilated cardiomyopathy. DESIGN: Analysis of recipient myocardial tissue and serum from patients with dilated cardiomyopathy and controls undergoing cardiac transplantation for end-stage cardiac disease. SETTING: University virology department and transplantation unit. METHODS: Reverse transcriptase-polymerase chain reaction and nucleotide sequence analysis of myocardial RNA and DNA; enterovirus-specific in situ hybridization; enterovirus-specific immunoglobulin M detection. RESULTS: Enterovirus RNA was detected in myocardial tissue from only a small proportion of (five of 75) hearts. However, although enterovirus-specific immunoglobulin M responses were detected in 22 (28%) of 39 controls patients, a significantly higher prevalence was observed among patients with dilated cardiomyopathy (22 (56%) of 39 patients; P < 0.005). All enteroviruses detected in myocardium showed greatest nucleotide sequence homology with coxsackievirus type B3. Detection of enterovirus RNA in myocardium by the polymerase chain reaction and by in situ hybridisation gave comparable results. Other potentially cardiotropic virus genomes, including human cytomegalovirus, influenzaviruses, and coronaviruses were not detected in myocardium. CONCLUSION: This study found that enterovirus-specific immunoglobulin M responses provided the strongest evidence of enterovirus involvement in patients with end-stage dilated cardiomyopathy. However, the high background prevalence of these responses limits their diagnostic value. The finding that enteroviruses detected in myocardium were coxsackievirus type B3 accords with recent findings in patients with acute myocarditis, and indicates that this serotype is the major cardiotropic human enterovirus. Images PMID:8868984

  13. 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

  14. Resveratrol Inhibits Aortic Root Dilatation in the Fbn1C1039G/+ Marfan Mouse Model

    PubMed Central

    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.

    2016-01-01

    Objective— 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 Fbn1C1039G/+ MFS mouse model. Approach and Results— 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. Conclusions— 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. PMID:27283746

  15. The frictional flow of a dense granular material based on the dilatant double shearing model

    SciTech Connect

    Zhu, H.; Mehrabadi, M.M.; Massoudi, M.C.

    2007-01-01

    Slow flow of granular materials, which typically occurs during the emptying of industrial storage hoppers and bins, has great industrial relevance. In the present study, we have employed our newly developed dilatant double shearing model [H. Zhu, M.M. Mehrabadi, M. Massoudi, Incorporating the effects of fabric in the dilatant double shearing model for granular materials, Int. J. Plast. 22 (2006) 628-653] to study the slow flow of a frictional, dense granular material. Although most models pertain only to the fully developed granular flow, the application of the dilatant double shearing model is shown to be valid from the onset of granular flow to the fully developed granular flow. In this paper, we use the finite element program ABAQUS/Explicit to numerically simulate the granular Couette flow and the frictional granular flow in a silo. For the granular Couette flow, the relative density variation and the velocity profile obtained by using the dilatant double shearing model are in good quantitative agreement with those obtained from a DEM simulation. For the frictional flow in a silo, the major principal stress directions are obtained at various time steps after the onset of silo discharge. We find that, in the hopper zone, the arching of the granular material between the sloping hopper walls is clearly demonstrated by the change in direction of the major principal stress. We also compare the pressure distribution along the wall before and after the onset of silo discharge. The numerical results show that the dilatant double shearing model is capable of capturing the essential features of the frictional granular flow.

  16. On the nature of gamma-ray burst time dilations

    NASA Technical Reports Server (NTRS)

    Wijers, Ralph A. M. J.; Paczynski, Bohdan

    1994-01-01

    The recent discovery that faint gamma-ray bursts are stretched in time relative to bright ones has been interpreted as support for cosmological distances: faint bursts have their durations redshifted relative to bright ones. It was pointed out, however, that the relative time stretching can also be produced by an intrinsic correlation bewteen duration and luminosity of gamma-ray bursts in a nearby, bounded distribution. While both models can explain the average amount of time stretching, we find a difference between them in the way the duration distribution of faint bursts deviates from that of bright ones, assuming the luminosity function of gamma-ray bursts is independent of distance. This allows us to distinguish between these two broad classes of model on the basis of the duration distributions of gamma-ray bursts, leading perhaps to an unambiguous determination of the distance scale of gamma-ray bursts. We apply our proposed test to the second Burst and Transient Source Experiment (BATSE) catalog and conclude, with some caution, that the data favor a cosmological interpretation of the time dilation.

  17. Keep Your Vision Healthy: Learn About Comprehensive Dilated Eye Exams

    MedlinePlus

    ... please review our exit disclaimer . Subscribe Keep Your Vision Healthy Learn About Comprehensive Dilated Eye Exams People ... should have their eyesight tested to keep their vision at its best. Children usually have vision screening ...

  18. An unusual triad: Bilateral dilated odontoma, hypodontia and peg laterals.

    PubMed

    Sebastian, Alphy Alphonsa; Ahsan, Auswaf; George, Ahkin John; Aby, John

    2013-09-01

    The dilated odontoma is an infrequent developmental alteration that appears in any area of the dental arches and can affect deciduous, permanent and supernumerary tooth. Dens invaginatus is a developmental anomaly resulting from invagination of a portion of crown forming within the enamel organ during odontogenesis. The most extreme form of dens invaginatus is known as dilated odontoma. The aim of this case report is to present a rare case of bilateral dilated odontoma affecting a microdontic permanent lateral incisor in a 30 year old female patient with hypodontia and peglateral teeth with its clinical, radiological and histological features, which has yet been not reported. Bilateral presence of dilated odontoma is not a common occurrence, although a single tooth involvement in each case has been reported in the literature.

  19. The use of radiofrequency catheter ablation to cure dilated cardiomyopathy.

    PubMed

    Schmidt, S B; Lobban, J H; Reddy, S; Hoelper, M; Palmer, D L

    1997-01-01

    Incessant supraventricular tachycardia can cause a dilated cardiomyopathy. This article discusses the case of a 55-year-old woman whose cardiomyopathy was reversed when she underwent successful radiofrequency catheter ablation of a unifocal atrial tachycardia. PMID:9197188

  20. 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.

  1. A case of nemaline myopathy with associated dilated cardiomyopathy and respiratory failure.

    PubMed

    Nagata, Rihito; Kamimura, Daisuke; Suzuki, Yoji; Saito, Toshihiko; Toyama, Hideshi; Dejima, Tohru; Inada, Haruhiko; Miwa, Yoshiyuki; Uchino, Kazuaki; Umemura, Satoshi; Shimizu, Makoto

    2011-01-01

    Nemaline myopathy is a representative form of congenital myopathy, and is characterized by nemaline bodies in muscle fibers. Here we report a 47-year-old man with congenital nemaline myopathy complicated with dilated cardiomyopathy-related heart failure, and restrictive respiratory failure. The complication of dilated cardiomyopathy in nemaline myopathy has rarely been reported. In this case, nemaline bodies were detected in the cardiac muscle fibers, demonstrating the presence of underlying disease-related myocardial degeneration. The patient responded to the combination of conventional therapy for heart failure including β-blocker and noninvasive continuous positive-pressure ventilation for respiratory failure. His general condition has been stable during a 10-month follow up period. PMID:22188717

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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

  7. Alterations in cardiac DNA methylation in human dilated cardiomyopathy

    PubMed Central

    Haas, Jan; Frese, Karen S; Park, Yoon Jung; Keller, Andreas; Vogel, Britta; Lindroth, Anders M; Weichenhan, Dieter; Franke, Jennifer; Fischer, Simon; Bauer, Andrea; Marquart, Sabine; Sedaghat-Hamedani, Farbod; Kayvanpour, Elham; Köhler, Doreen; Wolf, Nadine M; Hassel, Sarah; Nietsch, Rouven; Wieland, Thomas; Ehlermann, Philipp; Schultz, Jobst-Hendrik; Dösch, Andreas; Mereles, Derliz; Hardt, Stefan; Backs, Johannes; Hoheisel, Jörg D; Plass, Christoph; Katus, Hugo A; Meder, Benjamin

    2013-01-01

    Dilated cardiomyopathies (DCM) show remarkable variability in their age of onset, phenotypic presentation, and clinical course. Hence, disease mechanisms must exist that modify the occurrence and progression of DCM, either by genetic or epigenetic factors that may interact with environmental stimuli. In the present study, we examined genome-wide cardiac DNA methylation in patients with idiopathic DCM and controls. We detected methylation differences in pathways related to heart disease, but also in genes with yet unknown function in DCM or heart failure, namely Lymphocyte antigen 75 (LY75), Tyrosine kinase-type cell surface receptor HER3 (ERBB3), Homeobox B13 (HOXB13) and Adenosine receptor A2A (ADORA2A). Mass-spectrometric analysis and bisulphite-sequencing enabled confirmation of the observed DNA methylation changes in independent cohorts. Aberrant DNA methylation in DCM patients was associated with significant changes in LY75 and ADORA2A mRNA expression, but not in ERBB3 and HOXB13. In vivo studies of orthologous ly75 and adora2a in zebrafish demonstrate a functional role of these genes in adaptive or maladaptive pathways in heart failure. PMID:23341106

  8. What happens when we switch tasks: pupil dilation in multitasking.

    PubMed

    Katidioti, Ioanna; Borst, Jelmer P; Taatgen, Niels A

    2014-12-01

    Interruption studies typically focus on external interruptions, even though self-interruptions occur at least as often in real work environments. In this article, we therefore contrast external interruptions with self-interruptions. Three multitasking experiments were conducted, in which we examined changes in pupil size when participants switched from a primary to a secondary task. Results showed an increase in pupil dilation several seconds before a self-interruption, which we could attribute to the decision to switch. This indicates that the decision takes a relatively large amount of time. This was supported by the fact that in Experiment 2, participants were significantly slower on the self-interruption blocks than on the external interruption blocks. These findings suggest that the decision to switch is costly, but may also be open for modification through appropriate training. In addition, we propose that if one must switch tasks, it can be more efficient to implement a forced switch after the completion of a subtask instead of leaving the decision to the user.

  9. Celiac disease prevalence in Brazilian dilated cardiomyopathy patients.

    PubMed

    De Bem, Ricardo Schmit T; Da Ro Sa Utiyama, Shirley Ramos; Nisihara, Renato Mitsunori; Fortunato, Jerônimo Antônio; Tondo, Josué Augusto; Carmes, Eliane Ribeiro; Souza, Raquel Almada E; Pisani, Julio César; Amarante, Heda Maria Barska Dos Santos

    2006-05-01

    Celiac disease (CD) is a permanent condition of gluten intolerance and a number of autoimmune diseases have been associated with it. In the past few years, a relation between CD and dilated cardiomyopathy (CM) was described in Europe and United States. The aim of this study was to evaluate the prevalence of CD among south Brazilian precardiac transplant patients with advanced CM. A total of 74 patients on a list for heart transplantation were evaluated for the presence CD. The presence of anti-endomisial antibody (IgA-EmA) was determined by indirect immunofluorescence and for the anti-transglutaminase antibody (IgA anti-h-tTG) by ELISA. Serologically positive patients were submitted to upper endoscopy with intestinal biopsy. Two individuals (2.63%) were positive for IgA-EmA and 5 (6.75%) for IgA anti-h-tTG; 1 (1.35%) had both tests positive. Histologic confirmation of CD occurred only in the IgA-EmA positive patients. In conclusion, data from the present study allows recommend the screening for CD in patients with CM using IgA-EmA test as the method of choice. PMID:16758314

  10. 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.

  11. 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.

  12. 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. PMID:23551070

  13. Deformation and fluid-rock interaction in metasomatic dilatant shear bands

    NASA Astrophysics Data System (ADS)

    McCaig, A. M.

    1987-04-01

    The microstructure and microchemistry of shear bands from phyllonites along the Merens Fault in the Axial Zone of the Pyrenees are described. Deformation was accompanied by the influx of a metasomatic fluid carrying Fe and Mg which altered muscovite to chlorite and precipitated chlorite and quartz in dilatant sites. Overall volume increases in shear bands were two to two and a half times if the mobility of Al was low. Al was probably supplied to chlorites growing from solution by isovolumetric replacement of nearby muscovite by chlorite, but Fe and Mg must have been transported on a larger scale. Chlorite platelets grew with a linear-decussate fabric with 001 planes parallel to the local extension direction. The most likely geometry for dilation was in "pull-apart" sites on stepped micro-faults or shear zones. Such sites acted as pumps, drawing reactive fluid in from outside the rock along high permeability pathways parallel to the shearbands. The larger-scale pattern of circulation is unknown but field relations suggest fluid movement on a scale of hundreds of metres or more. The relatively low concentration of Fe and Mg in natural hydrothermal brines implies that fluid-rock ratios in the shear bands were high. This requires a cyclical, crack-seal mode of infiltration. Reactions may have enhanced ductility by producing fine-grained products, and by allowing the opening of dilatant sites, but deformation undoubtedly influenced the location of reactions and possibly their rates.

  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. 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, having aimed to evaluate the long-term clinical safety and efficacy of pneumatic dilation. In total, 35 consecutive patients with idiopathic achalasia who underwent pneumatic dilation were followed up at regular intervals in person or by a phone interview over a 10-year period. The mean duration of the follow-up was 43.03 ± 26.34 months (range 6–120 months). Remission was assessed by the dysphagia classification and symptom scores. Patients’ clinical symptom scores were calculated before and at 6 to 36 months, 37 to 60 months, and >60 months after therapy. The influence of the patients’ age, gender, and disease duration on the therapeutic effect was analyzed. The success rate of the operation was 97.2% (35/36), without massive hemorrhaging, perforation or other serious complications. Dysphagia after the therapy was significantly eased (P < 0.01). In total, 35 patients have been followed up for 6 to 36 months after therapy, 21 cases for 37 to 60 months, and 5 cases for >60 months, and the patients’ symptom scores separately decreased significantly compared with the pretherapy scores (P < 0.01). For these patients, the 6 to 36 months remission rate was 85.7% (30/35), the 37 to 60 months rate was 61.9% (13/21), and the >60 months rate was 40% (2/5). The dilation effect had no relationship to the patient's age, gender, and disease duration (P > 0.05). The patients in 30 cases (85.7%) were successfully treated with a single dilation, in 4 cases (11.4%) with 2 dilations, and in 1 case (2.9%) with 3 dilations

  17. 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

  18. Balloon dilators for labor induction: a historical review.

    PubMed

    Smith, James Andrew

    2013-01-01

    A number of recent articles attribute the origin of the use of cervical balloon dilation in the induction of labor to either Barnes in the 1860s or Embrey and Mollison in the 1960s. This review examines the historical record and reveals that, based on current practice attribution should rather be made to two contemporaries of Barnes: the Storer and Mattei. More importantly, Storer's warning about the rubber used in dilators was ignored, leading to decades of possibly unnecessary deaths following childbirth. To conduct this study key search terms for PubMed, Google Scholar and the website of the University of Ryerson were utilized as "Barnes", "Woodman", "balloon dilation", "balloon catheter", "foley", "colpeurynter", "cervix uteri" and "induction." Subsequent analysis was done on downloaded articles using BibDesk.

  19. Pulmonary artery dilatation: an overlooked mechanism for angina pectoris.

    PubMed

    Ginghina, Carmen; Popescu, Bogdan A; Enache, Roxana; Ungureanu, Catalina; Deleanu, Dan; Platon, Pavel

    2008-07-01

    Dilatation of the pulmonary artery may lead to the compression of adjacent structures. Of those, the extrinsic compression of the left main coronary artery is the most worrisome. We present the case of a 48-year-old woman who was diagnosed with pulmonary artery dilatation due to severe, thromboembolic pulmonary hypertension. She also had angina and coronary angiography revealed a 70% ostial stenosis of the left main coronary artery. The presence of this isolated lesion in a young woman without risk factors for atherosclerosis suggests extrinsic compression of the left main coronary artery by the dilated pulmonary artery as the likely mechanism. The patient underwent direct stenting of the left main coronary stenosis with a good result.

  20. Patient with Eating Disorder, Carnitine Deficiency and Dilated Cardiomyopathy.

    PubMed

    Fotino, A Domnica; Sherma, A

    2015-01-01

    Dilated cardiomyopathy is characterized by a dilated and poorly functioning left ventricle and can result from several different etiologies including ischemic, infectious, metabolic, toxins, autoimmune processes or nutritional deficiencies. Carnitine deficiency-induced cardiomyopathy (CDIM) is an uncommon cause of dilated cardiomyopathy that can go untreated if not considered. Here, we describe a 30-year-old woman with an eating disorder and recent percutaneous endoscopic gastrotomy (PEG) tube placement for weight loss admitted to the hospital for possible PEG tube infection. Carnitine level was found to be low. Transthoracic echocardiogram (TTE) revealed ejection fraction 15%. Her hospital course was complicated by sepsis from a peripherally inserted central catheter (PICC). She was discharged on a beta-blocker and carnitine supplementation. One month later her cardiac function had normalized. Carnitine deficiency-induced myopathy is an unusual cause of cardiomyopathy and should be considered in adults with decreased oral intake or malabsorption who present with cardiomyopathy. PMID:27159507

  1. Longitudinal shear wave and transverse dilatational wave in solids.

    PubMed

    Catheline, S; Benech, N

    2015-02-01

    Dilatation wave involves compression and extension and is known as the curl-free solution of the elastodynamic equation. Shear wave on the contrary does not involve any change in volume and is the divergence-free solution. This letter seeks to examine the elastodynamic Green's function through this definition. By separating the Green's function in divergence-free and curl-free terms, it appears first that, strictly speaking, the longitudinal wave is not a pure dilatation wave and the transverse wave is neither a pure shear wave. Second, not only a longitudinal shear wave but also a transverse dilatational wave exists. These waves are shown to be a part of the solution known as coupling terms. Their special motion is carefully described and illustrated.

  2. Pupil dilation patterns reflect the contents of consciousness.

    PubMed

    Kang, Olivia; Wheatley, Thalia

    2015-09-01

    The study of human consciousness has historically depended on introspection. However, introspection is constrained by what can be remembered and verbalized. Here, we demonstrate the utility of high temporal resolution pupillometry to track the locus of conscious attention dynamically, over a single trial. While eye-tracked, participants heard several musical clips played diotically (same music in each ear) and, later, dichotically (two clips played simultaneously, one in each ear). During dichotic presentation, participants attended to only one ear. We found that the temporal pattern of pupil dilation dynamics over a single trial discriminated which piece of music was consciously attended on dichotic trials. Deconvolving these pupillary responses further revealed the real-time changes in stimulus salience motivating pupil dilation. Taken together, these results show that pupil dilation patterns during single-exposure to dynamic stimuli can be exploited to discern the contents of conscious attention.

  3. The Efficacy of Endoscopic Papillary Balloon Dilation for Patients with Acute Biliary Pancreatitis

    PubMed Central

    Sun, Wei-Chih; Chan, Hoi-Hung; Lai, Kwok-Hung; Tsai, Tzung-Jiun; Lin, Huey-Shyan; Lin, Kung-Hung; Wang, Kai-Ming; Kao, Sung-Shuo; Chiang, Po-Hung; Cheng, Jin-Shiung; Hsu, Ping-I; Tsai, Wei-Lun; Chen, Wen-Chi; Li, Yun-Da; Wang, E-Ming

    2015-01-01

    Background. No study investigated the efficacy and safety of endoscopic papillary balloon dilation (EPBD) for the treatment of acute biliary pancreatitis (ABP). Method. We retrospectively reviewed the effects of EPBD on patients with ABP from February 2003 to December 2012. The general data, findings of image studies, details of the procedure, and outcomes after EPBD were analyzed. Result. Total 183 patients (male/female: 110/73) were enrolled. The mean age was 65.9 years. Among them, 155 patients had mild pancreatitis. The meantime from admission to EPBD was 3.3 days. Cholangiogram revealed filling defects inside the common bile duct (CBD) in 149 patients. The mean dilating balloon size was 10.5 mm and mean duration of the dilating procedure was 4.3 minutes. Overall, 124 patients had gross stones retrieved from CBD. Four (2.2%) adverse events and 2 (1.1%) intraprocedure bleeding incidents but no procedure-related mortality were noted. Bilirubin and amylase levels significantly decreased after EPBD. On average, patients resumed oral intake within 1.4 days. The clinical parameters and outcomes were similar in patients with different severity of pancreatitis. Conclusion. EPBD can be effective and safe for the treatment of ABP, even in patients presenting with severe disease. PMID:25949236

  4. The Accordion Sign in the Transplant Ureter: Ramifications During Balloon Dilation of Strictures

    SciTech Connect

    Kriegshauser, J. Scott Naidu, Sailen G.; Chang, Yu-Hui H.; Huettl, Eric A.

    2015-04-15

    PurposeThis study was designed to demonstrate the accordion sign within the transplant ureter and evaluate its ramifications during balloon dilation of strictures.MethodsA retrospective electronic chart and imaging review included demographic characteristics, procedure reports, and complications of 28 renal transplant patients having ureteral strictures treated with percutaneous balloon dilation reported in our transplant nephrology database during an 8-year period. The accordion sign was deemed present or absent on the basis of an imaging review and was defined as present when a tortuous ureter became kinked and irregular when foreshortened after placement of a wire or a catheter. Procedure-related urine leaks were categorized as occurring at the stricture if within 2 cm; otherwise, they were considered away from the stricture.ResultsThe accordion sign was associated with a significantly greater occurrence of leaks away from the stricture (P = 0.001) but not at the stricture (P = 0.34).ConclusionsThe accordion sign is an important consideration when performing balloon dilation procedures on transplant ureteral strictures, given the increased risk of leak away from the stricture. Its presence should prompt additional care during wire and catheter manipulations.

  5. Dilation of the oropharynx via selective stimulation of the hypoglossal nerve

    NASA Astrophysics Data System (ADS)

    Huang, Jingtao; Sahin, Mesut; Durand, Dominique M.

    2005-12-01

    The functional effects of selective hypoglossal nerve (HG) stimulation with a multi-contact peripheral nerve electrode were assessed using images of the upper airways and the tongue in anesthetized beagles. A biphasic pulse train of 50 Hz frequency and 2 s duration was applied through each one of the tripolar contact sets of the nerve electrode while the pharyngeal images were acquired into a computer. The stimulation current was limited to 20% above the activation threshold for maximum selectivity. The images showed that various contact sets could generate several different activation patterns of the tongue muscles resulting in medial and/or lateral dilation and closing of the airways at the tongue root. Some of these patterns translated into an increase in the oropharyngeal size while others did not have any effect. The pharyngeal sizes were not statistically different during stimulation either between the two different positions of the head (30° and 60°), or when the lateral contacts were compared with the medial ones. The contacts that had the least effect generated an average of 53 ± 15% pharyngeal dilation relative to the best contacts, indicating that the results are marginally sensitive to the contact position around the HG nerve trunk. These results suggest that selective HG nerve stimulation can be a useful technique to produce multiple tongue activation patterns that can dilate the pharynx. This may in turn increase the size of the patient population who can benefit from HG nerve stimulation as a treatment method for obstructive sleep apnea.

  6. Dilation of the oropharynx via selective stimulation of the hypoglossal nerve.

    PubMed

    Huang, Jingtao; Sahin, Mesut; Durand, Dominique M

    2005-12-01

    The functional effects of selective hypoglossal nerve (HG) stimulation with a multi-contact peripheral nerve electrode were assessed using images of the upper airways and the tongue in anesthetized beagles. A biphasic pulse train of 50 Hz frequency and 2 s duration was applied through each one of the tripolar contact sets of the nerve electrode while the pharyngeal images were acquired into a computer. The stimulation current was limited to 20% above the activation threshold for maximum selectivity. The images showed that various contact sets could generate several different activation patterns of the tongue muscles resulting in medial and/or lateral dilation and closing of the airways at the tongue root. Some of these patterns translated into an increase in the oropharyngeal size while others did not have any effect. The pharyngeal sizes were not statistically different during stimulation either between the two different positions of the head (30 degrees and 60 degrees), or when the lateral contacts were compared with the medial ones. The contacts that had the least effect generated an average of 53 +/- 15% pharyngeal dilation relative to the best contacts, indicating that the results are marginally sensitive to the contact position around the HG nerve trunk. These results suggest that selective HG nerve stimulation can be a useful technique to produce multiple tongue activation patterns that can dilate the pharynx. This may in turn increase the size of the patient population who can benefit from HG nerve stimulation as a treatment method for obstructive sleep apnea. PMID:16317230

  7. Shared Genetic Predisposition in Peripartum and Dilated Cardiomyopathies.

    PubMed

    Ware, James S; Li, Jian; Mazaika, Erica; Yasso, Christopher M; DeSouza, Tiffany; Cappola, Thomas P; Tsai, Emily J; Hilfiker-Kleiner, Denise; Kamiya, Chizuko A; Mazzarotto, Francesco; Cook, Stuart A; Halder, Indrani; Prasad, Sanjay K; Pisarcik, Jessica; Hanley-Yanez, Karen; Alharethi, Rami; Damp, Julie; Hsich, Eileen; Elkayam, Uri; Sheppard, Richard; Kealey, Angela; Alexis, Jeffrey; Ramani, Gautam; Safirstein, Jordan; Boehmer, John; Pauly, Daniel F; Wittstein, Ilan S; Thohan, Vinay; Zucker, Mark J; Liu, Peter; Gorcsan, John; McNamara, Dennis M; Seidman, Christine E; Seidman, Jonathan G; Arany, Zoltan

    2016-01-21

    Background Peripartum cardiomyopathy shares some clinical features with idiopathic dilated cardiomyopathy, a disorder caused by mutations in more than 40 genes, including TTN, which encodes the sarcomere protein titin. Methods In 172 women with peripartum cardiomyopathy, we sequenced 43 genes with variants that have been associated with dilated cardiomyopathy. We compared the prevalence of different variant types (nonsense, frameshift, and splicing) in these women with the prevalence of such variants in persons with dilated cardiomyopathy and with population controls. Results We identified 26 distinct, rare truncating variants in eight genes among women with peripartum cardiomyopathy. The prevalence of truncating variants (26 in 172 [15%]) was significantly higher than that in a reference population of 60,706 persons (4.7%, P=1.3×10(-7)) but was similar to that in a cohort of patients with dilated cardiomyopathy (55 of 332 patients [17%], P=0.81). Two thirds of identified truncating variants were in TTN, as seen in 10% of the patients and in 1.4% of the reference population (P=2.7×10(-10)); almost all TTN variants were located in the titin A-band. Seven of the TTN truncating variants were previously reported in patients with idiopathic dilated cardiomyopathy. In a clinically well-characterized cohort of 83 women with peripartum cardiomyopathy, the presence of TTN truncating variants was significantly correlated with a lower ejection fraction at 1-year follow-up (P=0.005). Conclusions The distribution of truncating variants in a large series of women with peripartum cardiomyopathy was remarkably similar to that found in patients with idiopathic dilated cardiomyopathy. TTN truncating variants were the most prevalent genetic predisposition in each disorder.

  8. Shared Genetic Predisposition in Peripartum and Dilated Cardiomyopathies

    PubMed Central

    Ware, James S.; Li, Jian; Mazaika, Erica; Yasso, Christopher M.; DeSouza, Tiffany; Cappola, Thomas P.; Tsai, Emily J.; Hilfiker-Kleiner, Denise; Kamiya, Chizuko A.; Mazzarotto, Francesco; Cook, Stuart A.; Halder, Indrani; Prasad, Sanjay K.; Pisarcik, Jessica; Hanley-Yanez, Karen; Alharethi, Rami; Damp, Julie; Hsich, Eileen; Elkayam, Uri; Sheppard, Richard; Kealey, Angela; Alexis, Jeffrey; Ramani, Gautam; Safirstein, Jordan; Boehmer, John; Pauly, Daniel F.; Wittstein, Ilan S.; Thohan, Vinay; Zucker, Mark J.; Liu, Peter; Gorcsan, John; McNamara, Dennis M.; Seidman, Christine E.; Seidman, Jonathan G.; Arany, Zoltan

    2016-01-01

    BACKGROUND Peripartum cardiomyopathy shares some clinical features with idiopathic dilated cardiomyopathy, a disorder caused by mutations in more than 40 genes, including TTN, which encodes the sarcomere protein titin. METHODS In 172 women with peripartum cardiomyopathy, we sequenced 43 genes with variants that have been associated with dilated cardiomyopathy. We compared the prevalence of different variant types (nonsense, frameshift, and splicing) in these women with the prevalence of such variants in persons with dilated cardiomyopathy and with population controls. RESULTS We identified 26 distinct, rare truncating variants in eight genes among women with peripartum cardiomyopathy. The prevalence of truncating variants (26 in 172 [15%]) was significantly higher than that in a reference population of 60,706 persons (4.7%, P = 1.3×10−7) but was similar to that in a cohort of patients with dilated cardiomyopathy (55 of 332 patients [17%], P = 0.81). Two thirds of identified truncating variants were in TTN, as seen in 10% of the patients and in 1.4% of the reference population (P = 2.7×10−10); almost all TTN variants were located in the titin A-band. Seven of the TTN truncating variants were previously reported in patients with idiopathic dilated cardiomyopathy. In a clinically well-characterized cohort of 83 women with peripartum cardiomyopathy, the presence of TTN truncating variants was significantly correlated with a lower ejection fraction at 1-year follow-up (P = 0.005). CONCLUSIONS The distribution of truncating variants in a large series of women with peripartum cardiomyopathy was remarkably similar to that found in patients with idiopathic dilated cardiomyopathy. TTN truncating variants were the most prevalent genetic predisposition in each disorder. PMID:26735901

  9. Shared Genetic Predisposition in Peripartum and Dilated Cardiomyopathies.

    PubMed

    Ware, James S; Li, Jian; Mazaika, Erica; Yasso, Christopher M; DeSouza, Tiffany; Cappola, Thomas P; Tsai, Emily J; Hilfiker-Kleiner, Denise; Kamiya, Chizuko A; Mazzarotto, Francesco; Cook, Stuart A; Halder, Indrani; Prasad, Sanjay K; Pisarcik, Jessica; Hanley-Yanez, Karen; Alharethi, Rami; Damp, Julie; Hsich, Eileen; Elkayam, Uri; Sheppard, Richard; Kealey, Angela; Alexis, Jeffrey; Ramani, Gautam; Safirstein, Jordan; Boehmer, John; Pauly, Daniel F; Wittstein, Ilan S; Thohan, Vinay; Zucker, Mark J; Liu, Peter; Gorcsan, John; McNamara, Dennis M; Seidman, Christine E; Seidman, Jonathan G; Arany, Zoltan

    2016-01-21

    Background Peripartum cardiomyopathy shares some clinical features with idiopathic dilated cardiomyopathy, a disorder caused by mutations in more than 40 genes, including TTN, which encodes the sarcomere protein titin. Methods In 172 women with peripartum cardiomyopathy, we sequenced 43 genes with variants that have been associated with dilated cardiomyopathy. We compared the prevalence of different variant types (nonsense, frameshift, and splicing) in these women with the prevalence of such variants in persons with dilated cardiomyopathy and with population controls. Results We identified 26 distinct, rare truncating variants in eight genes among women with peripartum cardiomyopathy. The prevalence of truncating variants (26 in 172 [15%]) was significantly higher than that in a reference population of 60,706 persons (4.7%, P=1.3×10(-7)) but was similar to that in a cohort of patients with dilated cardiomyopathy (55 of 332 patients [17%], P=0.81). Two thirds of identified truncating variants were in TTN, as seen in 10% of the patients and in 1.4% of the reference population (P=2.7×10(-10)); almost all TTN variants were located in the titin A-band. Seven of the TTN truncating variants were previously reported in patients with idiopathic dilated cardiomyopathy. In a clinically well-characterized cohort of 83 women with peripartum cardiomyopathy, the presence of TTN truncating variants was significantly correlated with a lower ejection fraction at 1-year follow-up (P=0.005). Conclusions The distribution of truncating variants in a large series of women with peripartum cardiomyopathy was remarkably similar to that found in patients with idiopathic dilated cardiomyopathy. TTN truncating variants were the most prevalent genetic predisposition in each disorder. PMID:26735901

  10. Slip and Dilation Tendency Analysis of the Salt Wells 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

  11. Slip and Dilation Tendency Analysis of the San Emidio 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

  12. Slip and Dilation Tendency Anlysis of Neal Hot Springs Geothermal Area

    SciTech Connect

    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

  13. Dilatation in anastomosed arteries can be an artifact of explantation.

    PubMed

    LeGrand, E K; Stoloff, D R; Kirsch, W M; Zhu, Y H; Boukouvalas, Z; Hardesty, R

    1992-01-01

    Fusiform dilation of the anastomotic site was found at explantation in the majority of rabbit femoral arteries anastomosed with newly developed microclips. This observation was also noted at sutured anastomoses. The mechanism responsible for this morphologic finding was studied by the following experiments: 1) measuring and explanting anastomosed arteries relaxed with 20% lidocaine, 2) latex casts of microclipped arteries, 3) comparing angiographic and histologic morphometric data, and 4) examining synthetic vascular graft anastomoses with identical dilatation. The observations demonstrate that trauma associated with explantation (direct dissection and fixative perfusion) leads to arterial vasoconstriction, but focal medial damage at the anastomotic site prevents constriction at this site.

  14. Rare variant mutations identified in pediatric patients with dilated cardiomyopathy

    PubMed Central

    Rampersaud, Evadnie; Siegfried, Jill D; Norton, Nadine; Li, Duanxiang; Martin, Eden; Hershberger, Ray E

    2010-01-01

    Dilated cardiomyopathy (DCM) in infants and children can be partially explained by genetic cause but the catalogue of known genes is limited. We reviewed our database of 41 cases diagnosed with DCM before 18 years of age who underwent detailed clinical and genetic evaluation, and summarize here the evidence for mutations causing DCM in these cases from 15 genes (PSEN1, PSEN2, CSRP3, LBD3, MYH7, SCN5A, TCAP, TNNT2, LMNA, MYBPC3, MYH6, TNNC1, TNNI3, TPM1, and RBM20). Thirty-five of the 41 pediatric cases had relatives with adult-onset DCM. More males (66%) were found among children diagnosed after 1 year of age with DCM. Nineteen mutations in 9 genes were identified among 15 out of 41 patients; 3 patients (diagnosed at ages 2 weeks, 9 and 13 years) had multiple mutations. Of the 19 mutations identified in 12 families, mutations in TPM1 (32%) and TNNT2 (21%) were the most commonly found. Of the 6 patients diagnosed before 1 year of age, 3 had mutations in TPM1 (including a set of identical twins), 1 in TNNT2, 1 in MYH7, and 1 with multiple mutations (MYH7 and TNNC1). Most DCM was accompanied by advanced heart failure and need for cardiac transplantation. We conclude that in some cases pediatric DCM has a genetic basis, which is complicated by allelic and locus heterogeneity as seen in adult-onset DCM. We suggest that future prospective comprehensive family-based genetic studies of pediatric DCM are indicated to further define mutation frequencies in known genes and to discover novel genetic cause. PMID:21483645

  15. Rare variant mutations identified in pediatric patients with dilated cardiomyopathy.

    PubMed

    Rampersaud, Evadnie; Siegfried, Jill D; Norton, Nadine; Li, Duanxiang; Martin, Eden; Hershberger, Ray E

    2011-01-01

    Dilated cardiomyopathy (DCM) in infants and children can be partially explained by genetic cause but the catalogue of known genes is limited. We reviewed our database of 41 cases diagnosed with DCM before 18 years of age who underwent detailed clinical and genetic evaluation, and summarize here the evidence for mutations causing DCM in these cases from 15 genes (PSEN1, PSEN2, CSRP3, LBD3, MYH7, SCN5A, TCAP, TNNT2, LMNA, MYBPC3, MYH6, TNNC1, TNNI3, TPM1, and RBM20). Thirty-five of the 41 pediatric cases had relatives with adult-onset DCM. More males (66%) were found among children diagnosed after 1 year of age with DCM. Nineteen mutations in 9 genes were identified among 15 out of 41 patients; 3 patients (diagnosed at ages 2 weeks, 9 and 13 years) had multiple mutations. Of the 19 mutations identified in 12 families, mutations in TPM1 (32%) and TNNT2 (21%) were the most commonly found. Of the 6 patients diagnosed before 1 year of age, 3 had mutations in TPM1 (including a set of identical twins), 1 in TNNT2, 1 in MYH7, and 1 with multiple mutations (MYH7 and TNNC1). Most DCM was accompanied by advanced heart failure and need for cardiac transplantation. We conclude that in some cases pediatric DCM has a genetic basis, which is complicated by allelic and locus heterogeneity as seen in adult-onset DCM. We suggest that future prospective comprehensive family-based genetic studies of pediatric DCM are indicated to further define mutation frequencies in known genes and to discover novel genetic cause. PMID:21483645

  16. Multilobed cystic dilation of the ventriculus terminalis (CDVT).

    PubMed

    Bellocchi, Silvio; Vidale, Simone; Casiraghi, Paolo; Arnaboldi, Marco; Taborelli, Angelo

    2013-01-01

    The cystic dilation of ventriculus terminalis (CDVT) is a rare anatomical variant in adulthood. In this report we describe a new case of an adult with multilobed CDVT, causing low-back pain and subjective disturbances in walking. A myelotomy with fenestration of the cyst was performed with a good clinical and radiological outcome.

  17. Multilobed cystic dilation of the ventriculus terminalis (CDVT)

    PubMed Central

    Bellocchi, Silvio; Vidale, Simone; Casiraghi, Paolo; Arnaboldi, Marco; Taborelli, Angelo

    2013-01-01

    The cystic dilation of ventriculus terminalis (CDVT) is a rare anatomical variant in adulthood. In this report we describe a new case of an adult with multilobed CDVT, causing low-back pain and subjective disturbances in walking. A myelotomy with fenestration of the cyst was performed with a good clinical and radiological outcome. PMID:23682083

  18. Pupil dilation dynamics track attention to high-level information.

    PubMed

    Kang, Olivia E; Huffer, Katherine E; Wheatley, Thalia P

    2014-01-01

    It has long been thought that the eyes index the inner workings of the mind. Consistent with this intuition, empirical research has demonstrated that pupils dilate as a consequence of attentional effort. Recently, Smallwood et al. (2011) demonstrated that pupil dilations not only provide an index of overall attentional effort, but are time-locked to stimulus changes during attention (but not during mind-wandering). This finding suggests that pupil dilations afford a dynamic readout of conscious information processing. However, because stimulus onsets in their study involved shifts in luminance as well as information, they could not determine whether this coupling of stimulus and pupillary dynamics reflected attention to low-level (luminance) or high-level (information) changes. Here, we replicated the methodology and findings of Smallwood et al. (2011) while controlling for luminance changes. When presented with isoluminant digit sequences, participants' pupillary dilations were synchronized with stimulus onsets when attending, but not when mind-wandering. This replicates Smallwood et al. (2011) and clarifies their finding by demonstrating that stimulus-pupil coupling reflects online cognitive processing beyond sensory gain.

  19. The Universality of Time Dilation and Space Contraction.

    ERIC Educational Resources Information Center

    Daly, Lisa N.; Horton, George K.

    1994-01-01

    Describes the extended general physics course taught at Rutgers University. The course presents to students at the high school algebra level the topic of analyzing a particular thought experiment that yields the time dilation formula and subsequently space contraction, velocity addition, and other 20th-century physics concepts. (MVL)

  20. Spontaneous delivery through a cervical tear without cervical os dilatation.

    PubMed

    Djokovic, Dusan; Costa, Cristina; Martins, Ana; Abushad, Shadi

    2015-01-01

    Spontaneous delivery through a cervical tear, provoked by prostaglandin-induced uterine contractions, was described in a G2P0 woman with a history of cervical dilatation and uterine curettage. This rare complication with potentially serious maternal-fetal consequences can be predicted by an aberrant cervical response to prostaglandins in parturients with previous cervical interventions. PMID:25678963

  1. Arborescent vascular dilatation mimicking Lichtenberg figures from lightning.

    PubMed

    Tempark, Therdpong; Iwasaki, Julie; Shwayder, Tor

    2014-01-01

    The clinical presentation of arborizing vascular dilatation can resemble Lichtenberg figures from lightning. Both have a feather-like or ferning pattern. We report an interesting case of pressure-induced vasodilatation (PIV) caused by temporary vascular occlusion from jeans buttons. PMID:24846790

  2. Omasal dilation and displacement in 4 Holstein dairy cows

    PubMed Central

    Bicalho, Rodrigo C.; Mayers, Heather M.; Cheong, Soon Hon; Rosa, Brielle V.; Guard, Charles L.

    2009-01-01

    Cases of omasal dilation and displacement in 4 dairy cows are described. The disease was initially diagnosed by a combination of history and clinical signs that included right-sided abdominal distension, rectal palpation, and decreased milk production. The condition was confirmed by laparotomy or necropsy. PMID:19436447

  3. Cerebral abscess complicating dilatation of a corrosive esophageal stricture.

    PubMed

    Djupesland, P; Solgaard, T; Mair, I W

    1991-01-01

    A case is presented in which a metastatic cerebral abscess developed in a 62-year-old female who required repeated dilatation for an esophageal stricture following accidental ingestion of liquid caustic soda. The literature is reviewed and management suggested for the avoidance of this uncommon complication.

  4. 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 Section 884.4260 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... conical and expansible material made from the root of a seaweed (Laminaria digitata or Laminaria...

  5. 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 Section 884.4260 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... conical and expansible material made from the root of a seaweed (Laminaria digitata or Laminaria...

  6. 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 Section 884.4260 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... conical and expansible material made from the root of a seaweed (Laminaria digitata or Laminaria...

  7. 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 Section 884.4260 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... conical and expansible material made from the root of a seaweed (Laminaria digitata or Laminaria...

  8. Spontaneous delivery through a cervical tear without cervical os dilatation

    PubMed Central

    Djokovic, Dusan; Costa, Cristina; Martins, Ana; Abushad, Shadi

    2015-01-01

    Key Clinical Message Spontaneous delivery through a cervical tear, provoked by prostaglandin-induced uterine contractions, was described in a G2P0 woman with a history of cervical dilatation and uterine curettage. This rare complication with potentially serious maternal–fetal consequences can be predicted by an aberrant cervical response to prostaglandins in parturients with previous cervical interventions. PMID:25678963

  9. Prolonged idiopathic gastric dilatation following revascularization for chronic mesenteric ischemia.

    PubMed

    Gauci, Julia L; Stoven, Samantha; Szarka, Lawrence; Papadakis, Konstantinos A

    2014-01-01

    A 71-year-old female presented with nausea, emesis, early satiety, and abdominal distension following revascularization for chronic mesenteric ischemia. Computed tomography angiogram showed gastric dilatation. Esophagogastroduodenoscopy, small bowel follow through, and paraneoplastic panel were negative. Gastric emptying was delayed. Despite conservative management, she required a percutaneous endoscopic jejunostomy. The development of a prolonged gastroparetic state has not been previously described. PMID:24975870

  10. Prolonged idiopathic gastric dilatation following revascularization for chronic mesenteric ischemia

    PubMed Central

    Gauci, Julia L.; Stoven, Samantha; Szarka, Lawrence; Papadakis, Konstantinos A.

    2014-01-01

    A 71-year-old female presented with nausea, emesis, early satiety, and abdominal distension following revascularization for chronic mesenteric ischemia. Computed tomography angiogram showed gastric dilatation. Esophagogastroduodenoscopy, small bowel follow through, and paraneoplastic panel were negative. Gastric emptying was delayed. Despite conservative management, she required a percutaneous endoscopic jejunostomy. The development of a prolonged gastroparetic state has not been previously described. PMID:24975870

  11. Intramyocardial angiogenic cell precursors in nonischemic dilated cardiomyopathy.

    PubMed

    Arom, Kitipan V; Ruengsakulrach, Permyos; Belkin, Michael; Tiensuwan, Montip

    2009-08-01

    To determine the efficacy of intramyocardial injection of angiogenic cell precursors in nonischemic dilated cardiomyopathy, 35 patients with nonischemic dilated cardiomyopathy underwent injections of angiogenic cell precursors into the left ventricle (cell group). Seventeen patients with nonischemic dilated cardiomyopathy were matched from the heart failure database to form a control group that was treated medically. Angiogenic cell precursors were obtained from autologous blood, cultured in vitro, and injected into all free-wall areas of the left ventricle in the cell group. After these injections, New York Heart Association functional class improved significantly by 1.1 +/- 0.7 classes at 284.7 +/- 136.2 days, and left ventricular ejection fraction improved in 71.4% of patients (25/35); the mean increase in left ventricular ejection fraction was 4.4% +/- 10.6% at 192.7 +/- 135.1 days. Improved quality of life was demonstrated by better physical function, role-physical, general health, and vitality domains in a short-form health survey at the 3-month follow-up. In the control group, there were no significant improvements in left ventricular ejection fraction or New York Heart Association class which increased by 0.6 +/- 0.8 classes. It was concluded that intramyocardial angiogenic cell precursor injection is probably effective in the treatment of nonischemic dilated cardiomyopathy. PMID:19713335

  12. Arborescent vascular dilatation mimicking Lichtenberg figures from lightning.

    PubMed

    Tempark, Therdpong; Iwasaki, Julie; Shwayder, Tor

    2014-01-01

    The clinical presentation of arborizing vascular dilatation can resemble Lichtenberg figures from lightning. Both have a feather-like or ferning pattern. We report an interesting case of pressure-induced vasodilatation (PIV) caused by temporary vascular occlusion from jeans buttons.

  13. Worldsheet dilatation operator for the AdS superstring

    NASA Astrophysics Data System (ADS)

    Ramírez, Israel; Vallilo, Brenno Carlini

    2016-05-01

    In this work we propose a systematic way to compute the logarithmic divergences of composite operators in the pure spinor description of the AdS 5 × S 5 superstring. The computations of these divergences can be summarized in terms of a dilatation operator acting on the local operators. We check our results with some important composite operators of the formalism.

  14. Unitary dilation models of Turing machines in quantum mechanics

    SciTech Connect

    Benioff, P.

    1995-05-01

    A goal of quantum-mechanical models of the computation process is the description of operators that model changes in the information-bearing degrees of freedom. Iteration of the operators should correspond to steps in the computation, and the final state of halting computations should be stable under iteration. The problem is that operators constructed directly from the process description do not have these properties. In general these operators annihilate the halted state. If information-erasing steps are present, there are additional problems. These problems are illustrated in this paper by consideration of operators for two simple one-step processes and two simple Turing machines. In general the operators are not unitary and, if erasing steps are present, they are not even contraction operators. Various methods of extension or dilation to unitary operators are discussed. Here unitary power dilations are considered as a solution to these problems. It is seen that these dilations automatically provide a good solution to the initial- and final-state problems. For processes with erasing steps, recording steps must be included prior to the dilation, but only for the steps that erase information. Hamiltonians for these processes are also discussed. It is noted that {ital H}, described by exp({minus}{ital iH}{Delta})={ital U}{sup {ital T}}, where {ital U}{sup {ital T}} is a unitary step operator for the process and {Delta} a time interval, has complexity problems. These problems and those noted above are avoided here by the use of the Feynman approach to constructing Hamiltonians directly from the unitary power dilations of the model operators. It is seen that the Hamiltonians so constructed have some interesting properties.

  15. Smooth endoplasmic reticulum dilation and degeneration in Purkinje neuron dendrites of aging ethanol-fed female rats.

    PubMed

    Dlugos, Cynthia A

    2006-01-01

    The effects of chronic ethanol consumption on the extensive Purkinje neuron (PN) dendritic arbor of male rats include dilation of the smooth endoplasmic reticulum (SER) and dendritic regression. The purpose of the present study was to examine the molecular layer of female rats for the presence of ethanol-related SER dilation and evidence of degeneration within the PN dendritic arbor. Twenty-one 12-month-old Fischer 344 female rats (n = 7/treatment group) received a liquid ethanol, liquid control, or rat chow diet for a period of 40 weeks. Ethanol-fed rats received 35% of their dietary calories as ethanol. Pair-fed rats received a liquid control diet that was isocaloric to the ethanol diet. Chow-fed rats received standard laboratory rat chow ad libitum. At the end of treatment, tissues from the anterior and posterior lobes of the cerebellar vermis were viewed and photographed with the electron microscope. The diameters of SER profiles were measured and the density of degenerating bodies within the PN dendritic arbor was quantitated. In the posterior lobe, ethanol-related SER dilation was apparent. In the anterior lobe, the density of degenerating bodies within PN dendritic shafts was significantly increased but SER dilation in PN dendritic shafts was absent. These results confirm that SER dilation and dendritic degeneration in PN dendrites may precede and contribute to ethanol-related regression in female rats. In addition, comparison of these results with data obtained in male rats from a previous study suggests that PN dendrites in females may be more sensitive to the effects of ethanol.

  16. What explains black-white differences in survival in idiopathic dilated cardiomyopathy? The Washington, DC, Dilated Cardiomyopathy Study.

    PubMed Central

    Coughlin, S. S.; Myers, L.; Michaels, R. K.

    1997-01-01

    We have found race to be an independent predictor of mortality in a preliminary analysis of data from an ongoing study of patients with idiopathic dilated cardiomyopathy. Our previous, analyses, however, were based on only 12 to 24 months of follow-up. In the present analysis, which is based on up to 5 years of follow-up, we extended our earlier observations and examined whether other socioeconomic factors account for the association with race. A total of 128 patients from five Washington, DC, area hospitals were included in the analysis. 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 < or = $15,000. No racial differences were found in cardiac medication usage, with the exception of beta blockers and antiarrhythmics. The cumulated survival among black patients at 12 and 60 months was 71.5% and 39.1%, respectively, compared with 92% and 31.4% among whites. Age, ventricular arrhythmias, and ejection fraction were significant predictors of survival in univariate analysis. The univariate association with black race was of borderline significance. In multivariable analysis using the proportional hazards model, age and ejection fraction were significant independent predictors of survival. The association with ventricular arrhythmias was of borderline significance. The association with black race, which was statistically nonsignificant, was diminished even further by adjustment for income and type of health insurance. Thus, the previously reported association with black race may be accounted for by socioeconomic factors related to access to health care. PMID:9145633

  17. Pupil Dilation and Object Permanence in Infants

    ERIC Educational Resources Information Center

    Sirois, Sylvain; Jackson, Iain R.

    2012-01-01

    This paper examines the relative merits of looking time and pupil diameter measures in the study of early cognitive abilities of infants. Ten-month-old infants took part in a modified version of the classic drawbridge experiment used to study object permanence (Baillargeon, Spelke, & Wasserman, 1985). The study involved a factorial design where…

  18. Neuronavigation-assisted single transseptal catheter implantation and shunt in patients with posthemorrhagic hydrocephalus and accentuated lateral ventricles dilatation

    PubMed Central

    Carvi Nievas, Mario N.

    2011-01-01

    Background: To assess the treatment of posthemorrhagic hydrocephalus with accentuated lateral ventricles dilatation by employing a single biventricular neuronavigation-assisted transseptal-implanted catheter with programmable valve and distal peritoneal derivation. Methods: A neuronavigation-assisted single transseptal biventricular catheter implantation with distal peritoneal shunt system was performed in 11 patients with posthemorrhagic hydrocephalus and accentuated lateral ventricles dilatations between 2001 and 2010. Patients with concomitant third ventricle dilatation were excluded. Several sequential frustrated attempts of temporary drainage occlusion on both sides confirmed the isolation of the lateral ventricles. Neuronavigation was employed to accurately establish the catheter surgical corridor (trajectory) across the lateral ventricles and throughout the septum pellucidum. The neurological and radiological outcomes were assessed at least 6 months after the procedure. Results: Catheter implantation was successfully performed in all patients. Only one catheter was found to be monoventricular on delayed computer tomography controls. Procedure-related complications (bleeding of infections) were not observed. No additional neurological deficits were found after shunt surgery. Six months after procedure, none required additional ventricular catheter implantations or shunt revisions. Radiological and clinical controls confirmed the shunt function and the improved neurological status of all patients. Conclusion: Single neuronavigation-assisted transseptal-implanted biventricular catheter is a valid option for the treatment of posthemorrhagic hydrocephalus with accentuated lateral ventricles dilatation. This technique reduces the number of catheters and minimizes the complexity and timing of the surgical procedure as well as potential infection's risks associated with the use of multiple shunting systems. PMID:21541201

  19. Detection of signature consistent with cosmological time dilation in gamma-ray bursts

    NASA Technical Reports Server (NTRS)

    Norris, J. P.; Nemiroff, R. J.; Scargle, J. D.; Kouveliotou, C.; Fishman, G. J.; Meegan, C. A.; Paciesas, W. S.; Bonnel, J. T.

    1994-01-01

    If gamma ray bursts are at cosmological distances-as suggested by their isotropic distribution on the sky and by their number-intensity relation-then the burst profiles will be stretched in time, by an amount proportional to the redshift, 1 + Z. We have tested data from the Compton Gamma Ray Observatory's (CGRO's) Burst and Transient Source Experiment (BATSE) for such time dilation. Out of 590 bursts observed by BATSE, 131 bursts were analyzed; bursts with durations shorter than 1.5 s were excluded. We used three tests to compare the timescales of bright and dim bursts, the latter, on average, being more distant than the former. Our measures of timescale are constructed to avoid selection effects arising from intensity differences by rescaling all bursts to fiducial levels of peak intensity and noise bias. (1) We found that the total rescaled count above background for the dim burst ensemble is approximately twice that for the brightest bursts-translating into longer durations for the dim bursts. (2) Wavelet-transform decompositions of the burst profiles confirmed that this dilation operates over a broad range of timescales. (3) Structure on the shortest timescales was examined using a procedure which aligns the highest peaks of profiles from which the noise has been optimally removed using a wavelet threshold technique. In all three tests, the dim bursts are stretched by a factor of approximately 2 relative to the bright ones, over seven octaves of timescale. We calibrated the measurements by dilating synthetic bursts that approximate the temporal characteristics of bright BATSE bursts. Results are consistent with bursts at BATSE's peak-flux completeness limit being at cosmological distances corresponding to Z approximately equal to 1, and thus with independent cosmological interpretations of the BATSE number-intensity relation. Alternative explanations of our results, arising from the nature of physical processes in bursts, are still possible.

  20. Borrowing from interventional radiology: novel technique to dilate scarred nephrostomy tract.

    PubMed

    Williams, Steve K; Bird, Vincent G; Maurici, Giuseppe; Leveillee, Raymond J

    2008-11-01

    Balloon dilation is an effective method of percutaneous renal access, but it can be impossible in patients with perirenal scarring. We report the use of an atherotomy cutting balloon for dilation of the chronic nephrostomy tract. The ease of use makes this device a useful alternative to standard dilation techniques. PMID:18657309

  1. Dens invaginatus (dilated odontome) in mandibular canine

    PubMed Central

    Halawar, Sangamesh S; Satyakiran, GVV; Krishnanand, PS; Prashanth, R

    2014-01-01

    Dens invaginatus is a developmental malformation of teeth related to shape of the teeth. Affected teeth show a deep infolding of enamel and dentin starting from the tip of the cusps and may extend deep into the root. It results from the invagination of the enamel organ into the dental papilla before calcification has occurred. Teeth most affected are maxillary lateral incisors. The presence of dens invaginatus in mandibular canine is extremely rare. The tooth was symptomatic in that it was mobile and was oriented horizontally. This article presents a case of symptomatic dens invaginatus in mandibular canine. PMID:25364169

  2. Radiocephalic Fistula Complicated by Distal Ischemia: Treatment by Ulnar Artery Dilatation

    SciTech Connect

    Raynaud, Alain; Novelli, Luigi Rovani, Xavier; Carreres, Thierry; Bourquelot, Pierre; Hermelin, Alain; Angel, C.; Beyssen, B.

    2010-02-15

    Hand ischemic steal syndrome due to a forearm arteriovenous fistula is a rare occurrence. However, its frequency is increasing with the rise in numbers of elderly and diabetic patients. This complication, which is more common for proximal than for distal accesses, can be very severe and may cause loss of hand function, damage to fingers, and even amputation of fingers or the hand. Its treatment is difficult and often leads to access loss. We report here a case of severe hand ischemia related to a radiocephalic fistula successfully treated by ulnar artery dilatation.

  3. Knock-out of nexilin in mice leads to dilated cardiomyopathy and endomyocardial fibroelastosis.

    PubMed

    Aherrahrou, Zouhair; Schlossarek, Saskia; Stoelting, Stephanie; Klinger, Matthias; Geertz, Birgit; Weinberger, Florian; Kessler, Thorsten; Aherrahrou, Redouane; Moreth, Kristin; Bekeredjian, Raffi; Hrabě de Angelis, Martin; Just, Steffen; Rottbauer, Wolfgang; Eschenhagen, Thomas; Schunkert, Heribert; Carrier, Lucie; Erdmann, Jeanette

    2016-01-01

    Cardiomyopathy is one of the most common causes of chronic heart failure worldwide. Mutations in the gene encoding nexilin (NEXN) occur in patients with both hypertrophic and dilated cardiomyopathy (DCM); however, little is known about the pathophysiological mechanisms and relevance of NEXN to these disorders. Here, we evaluated the functional role of NEXN using a constitutive Nexn knock-out (KO) mouse model. Heterozygous (Het) mice were inter-crossed to produce wild-type (WT), Het, and homozygous KO mice. At birth, 32, 46, and 22 % of the mice were WT, Het, and KO, respectively, which is close to the expected Mendelian ratio. After postnatal day 6, the survival of the Nexn KO mice decreased dramatically and all of the animals died by day 8. Phenotypic characterizations of the WT and KO mice were performed at postnatal days 1, 2, 4, and 6. At birth, the relative heart weights of the WT and KO mice were similar; however, at day 4, the relative heart weight of the KO group was 2.3-fold higher than of the WT group. In addition, the KO mice developed rapidly progressive cardiomyopathy with left ventricular dilation and wall thinning and decreased cardiac function. At day 6, the KO mice developed a fulminant DCM phenotype characterized by dilated ventricular chambers and systolic dysfunction. At this stage, collagen deposits and some elastin deposits were observed within the left ventricle cavity, which resembles the features of endomyocardial fibroelastosis (EFE). Overall, these results further emphasize the role of NEXN in DCM and suggest a novel role in EFE.

  4. Peripartum cardiomyopathy and dilated cardiomyopathy: different at heart

    PubMed Central

    Bollen, Ilse A. E.; Van Deel, Elza D.; Kuster, Diederik W. D.; Van Der Velden, Jolanda

    2015-01-01

    Peripartum cardiomyopathy (PPCM) is a severe cardiac disease occurring in the last month of pregnancy or in the first 5 months after delivery and shows many similar clinical characteristics as dilated cardiomyopathy (DCM) such as ventricle dilation and systolic dysfunction. While PPCM was believed to be DCM triggered by pregnancy, more and more studies show important differences between these diseases. While it is likely they share part of their pathogenesis such as increased oxidative stress and an impaired microvasculature, discrepancies seen in disease progression and outcome indicate there must be differences in pathogenesis as well. In this review, we compared studies in DCM and PPCM to search for overlapping and deviating disease etiology, pathogenesis and outcome in order to understand why these cardiomyopathies share similar clinical features but have different underlying pathologies. PMID:25642195

  5. Peripartum cardiomyopathy and dilated cardiomyopathy: different at heart.

    PubMed

    Bollen, Ilse A E; Van Deel, Elza D; Kuster, Diederik W D; Van Der Velden, Jolanda

    2014-01-01

    Peripartum cardiomyopathy (PPCM) is a severe cardiac disease occurring in the last month of pregnancy or in the first 5 months after delivery and shows many similar clinical characteristics as dilated cardiomyopathy (DCM) such as ventricle dilation and systolic dysfunction. While PPCM was believed to be DCM triggered by pregnancy, more and more studies show important differences between these diseases. While it is likely they share part of their pathogenesis such as increased oxidative stress and an impaired microvasculature, discrepancies seen in disease progression and outcome indicate there must be differences in pathogenesis as well. In this review, we compared studies in DCM and PPCM to search for overlapping and deviating disease etiology, pathogenesis and outcome in order to understand why these cardiomyopathies share similar clinical features but have different underlying pathologies. PMID:25642195

  6. Clinical management of dilated cardiomyopathy: current knowledge and future perspectives.

    PubMed

    Merlo, Marco; Cannatá, Antonio; Vitagliano, Alice; Zambon, Elena; Lardieri, Gerardina; Sinagra, Gianfranco

    2016-01-01

    Dilated cardiomyopathy (DCM) is a primary heart muscle disease characterized by a progressive dilation and dysfunction of either the left or both ventricles. The management of DCM is currently challenging for clinicians. The persistent lack of knowledge about the etiology and pathophysiology of this disease continues to determine important fields of uncertainty in managing this condition. Molecular cardiology and genetics currently represent the most crucial horizon of increasing knowledge. Understanding the mechanisms underlying the disease allows clinicians to treat this disease more effectively and to further improve outcomes of DCM patients through advancements in etiologic characterization, prognostic stratification and individualized therapy. Left ventricular reverse remodeling predicts a lower rate of major cardiac adverse events independently from other factors. Optimized medical treatment and device implantation are pivotal in inducing left ventricular reverse remodeling. Newly identified targets, such as angiotensin-neprilysin inhibition, phosphodiesterase inhibition and calcium sensitizing are important in improving prognosis in patients affected by DCM.

  7. Balloon Dilators for Labor Induction: a Historical Review

    PubMed Central

    Smith, James Andrew

    2013-01-01

    A number of recent articles attribute the origin of the use of cervical balloon dilation in the induction of labor to either Barnes in the 1860s or Embrey and Mollison in the 1960s. This review examines the historical record and reveals that, based on current practice attribution should rather be made to two contemporaries of Barnes: the Storer and Mattei. More importantly, Storer’s warning about the rubber used in dilators was ignored, leading to decades of possibly unnecessary deaths following childbirth. To conduct this study key search terms for PubMed, Google Scholar and the website of the University of Ryerson were utilized as “Barnes”, “Woodman”, “balloon dilation”, “balloon catheter”, “foley”, “colpeurynter”, “cervix uteri” and “induction.” Subsequent analysis was done on downloaded articles using BibDesk. PMID:24427487

  8. Reversible dilatancy in entangled single-wire materials.

    PubMed

    Rodney, David; Gadot, Benjamin; Martinez, Oriol Riu; du Roscoat, Sabine Rolland; Orgéas, Laurent

    2016-01-01

    Designing structures that dilate rapidly in both tension and compression would benefit devices such as smart filters, actuators or fasteners. This property however requires an unusual Poisson ratio, or Poisson function at finite strains, which has to vary with applied strain and exceed the familiar bounds: less than 0 in tension and above 1/2 in compression. Here, by combining mechanical tests and discrete element simulations, we show that a simple three-dimensional architected material, made of a self-entangled single long coiled wire, behaves in between discrete and continuum media, with a large and reversible dilatancy in both tension and compression. This unusual behaviour arises from an interplay between the elongation of the coiled wire and rearrangements due to steric effects, which, unlike in traditional discrete media, are hysteretically reversible when the architecture is made of an elastic fibre.

  9. Reversible dilatancy in entangled single-wire materials.

    PubMed

    Rodney, David; Gadot, Benjamin; Martinez, Oriol Riu; du Roscoat, Sabine Rolland; Orgéas, Laurent

    2016-01-01

    Designing structures that dilate rapidly in both tension and compression would benefit devices such as smart filters, actuators or fasteners. This property however requires an unusual Poisson ratio, or Poisson function at finite strains, which has to vary with applied strain and exceed the familiar bounds: less than 0 in tension and above 1/2 in compression. Here, by combining mechanical tests and discrete element simulations, we show that a simple three-dimensional architected material, made of a self-entangled single long coiled wire, behaves in between discrete and continuum media, with a large and reversible dilatancy in both tension and compression. This unusual behaviour arises from an interplay between the elongation of the coiled wire and rearrangements due to steric effects, which, unlike in traditional discrete media, are hysteretically reversible when the architecture is made of an elastic fibre. PMID:26413988

  10. Changes in myocardial cytoskeletal intermediate filaments and myocyte contractile dysfunction in dilated cardiomyopathy: an in vivo study in humans

    PubMed Central

    Di, S; Marotta, M; Salvatore, G; Cudemo, G; Cuda, G; De Vivo, F; Di, B; Ciaramella, F; Caputo, G; de Divitiis, O

    2000-01-01

    AIM—To investigate in vivo the intermediate cytoskeletal filaments desmin and vimentin in myocardial tissues from patients with dilated cardiomyopathy, and to determine whether alterations in these proteins are associated with impaired contractility.
METHODS—Endomyocardial biopsies were performed in 12 patients with dilated cardiomyopathy and in 12 controls (six women with breast cancer before anthracycline chemotherapy and six male donors for heart transplantation). Biopsy specimens were analysed by light microscopy and immunochemistry (desmin, vimentin). Myocyte contractile protein function was evaluated by the actin-myosin in vitro motility assay. Left ventricular ejection fraction was assessed by echocardiography and radionuclide ventriculography.
RESULTS—Patients with dilated cardiomyopathy had a greater cardiomyocyte diameter than controls (p < 0.01). The increase in cell size was associated with a reduction in contractile function, as assessed by actin-myosin motility (r = −0.643; p < 0.01). Quantitative immunochemistry showed increased desmin and vimentin contents (p < 0.01), and the desmin distribution was disturbed in cardiomyopathy. There was a linear relation between desmin distribution and actin-myosin sliding in vitro (r = 0.853; p < 0.01) and an inverse correlation between desmin content and ejection fraction (r = −0.773; p < 0.02). Negative correlations were also found between myocardial vimentin content and the actin-myosin sliding rate (r = −0.74; p < 0.02) and left ventricular ejection fraction (r = −0.68; p < 0.01).
CONCLUSIONS—Compared with normal individuals, the myocardial tissue of patients with dilated cardiomyopathy shows alterations of cytoskeletal intermediate filament distribution and content associated with reduced myocyte contraction.


Keywords: dilated cardiomyopathy; desmin; vimentin; cardiac biopsy; actin-myosin PMID:11083750

  11. A new rodent model for obstructive sleep apnea: effects on ATP-mediated dilations in cerebral arteries.

    PubMed

    Crossland, Randy F; Durgan, David J; Lloyd, Eric E; Phillips, Sharon C; Reddy, Anilkumar K; Marrelli, Sean P; Bryan, Robert M

    2013-08-15

    Obstructive sleep apnea (OSA), a condition in which the upper airway collapses during sleep, is strongly associated with metabolic and cardiovascular diseases. Little is known how OSA affects the cerebral circulation. The goals of this study were 1) to develop a rat model of chronic OSA that involved apnea and 2) to test the hypothesis that 4 wk of apneas during the sleep cycle alters endothelium-mediated dilations in middle cerebral arteries (MCAs). An obstruction device, which was chronically implanted into the trachea of rats, inflated to obstruct the airway 30 times/h for 8 h during the sleep cycle. After 4 wk of apneas, MCAs were isolated, pressurized, and exposed to luminally applied ATP, an endothelial P2Y2 receptor agonist that dilates through endothelial-derived nitric oxide (NO) and endothelial-dependent hyperpolarization (EDH). Dilations to ATP were attenuated ~30% in MCAs from rats undergoing apneas compared with those from a sham control group (P < 0.04 group effect; n = 7 and 10, respectively). When the NO component of the dilation was blocked to isolate the EDH component, the response to ATP in MCAs from the sham and apnea groups was similar. This finding suggests that the attenuated dilation to ATP must occur through reduced NO. In summary, we have successfully developed a novel rat model for chronic OSA that incorporates apnea during the sleep cycle. Using this model, we demonstrate that endothelial dysfunction occurred by 4 wk of apnea, likely increasing the vulnerability of the brain to cerebrovascular related accidents.

  12. Management experience of subglottic stenosis by endoscopic bougie dilatation with mitomycin C and review of literature: case series.

    PubMed

    Liew, Y T; Yong, D J; Somasundran, M; Lum, C L

    2015-03-01

    The aim of the study was to examine and analyze the epidemiology and outcome of treatment for paediatric acquired subglottic stenosis treated with endoscopic bougie dilatation and topical mitomycin C. There were 15 patients identified from 2008 until 2013. All of them had acquired subglottic stenosis due to history of intubation. Majority of the patients had grade III stenosis, with the total of seven. Three patients had grade IV; three were grade II and two were grade I. All of the patients with severe stenosis (grade III and IV) needed tracheostomy while only one in mild stenosis group (grade I and II) required it for prolonged ventilation rather than obstruction due to subglottic stenosis. All of them underwent direct laryngoscopy under general anesthesia followed by endoscopic dilatation with bougie and topical mitomycin C 0.4 mg/ml for 5 min. Aim of success in our study was decannulation of tracheostomy or absence of symptoms at exertion. We achieved 6 (60 %) successful decannulation out of 10 patients with tracheostomy (excluded the patient with tracheostomy in grade I stenosis due to prolonged ventilation). As for those without tracheostomy, 3 (75 %) out of 4 patients were asymptomatic even at exertion. Average number of dilatation was 3.1 times, with mean duration of 28 min. No complications were reported in our series. One patient with grade I stenosis passed away due to severe pneumonia unrelated to the stenosis or dilatation, and she did not have any dilatation before she passed away. Multiple related risk factors were identified such as intubation, prematurity, movement of endotracheal tube, respiratory infection, traumatic intubation and gastroesophageal reflux disease. Experience of open surgical method was very limited in our centre in Sabah in East Malaysia. Endoscopic technique plays an important role in treatment of subglottic stenosis with adjunct like mitomycin C possibly booster the successful rate.

  13. Clinical comparison of the efficiency and security of balloon dilators versus fascial dilators in percutaneous nephrolithotripsy (PCNL)

    PubMed Central

    Yang, Lingbo; Lu, Shuaiqi; Han, Xingtao; Wei, Pengtao; Yang, Jinhui; Hao, Tongtong

    2016-01-01

    Objective: To compare the efficiency and security of the balloon dilators versus fascial dilators in percutaneous nephrolithotripsy (PCNL), We compared the difference of intraoperative and postoperative parameters of patients using these two different methods of expansion and having no significant statistic differences in peroperative parameters. Methods: This is a retrospective analysis of 134 patients undergoing PCNL with upper urinary calculi from January 2012 to January 2014 in Luoyang Central Hospital affiliated to Zhengzhou University. These patients meeting the inclusion criteria were divided into two groups: the group of balloon dilators (group A) and the group of fascial dilators (group B). Two groups were compared for success rate of first expansion, clearance of stone, duration of surgery, intraoperative hemorrhage, blood transfusion rate, postoperative hospitalization and the incidence of complications. Result: In Group A, a total of 91 patients (51 men and 40 women, mean age 51.22±8.96 years, ranged from 28 to 68 years, the calculi maximum diameter from 0.9 to 4.5cm, 28 cases with a history of gravel, mean Body mass index 24.20±2.34, 73 cases with hydronephrosis and 26 cases with underlying diseases such as hypertension, diabetes and the like) undergoing PCNL were retrospectively reviewed. Similarly, In Group B, a total of 43 patients (28 men and 15 women, mean age 49.64±10.62 years, ranged from 15 to 70 years, the calculi maximum diameter from 1.1 to 5.2cm, 18 cases with a history of gravel, mean Body mass index 24.40±2.70, 38 cases with hydronephrosis and 14 cases with underlying diseases such as hypertension, diabetes and the like) undergoing PCNL were retrospectively reviewed. Our results showed that there was a statistically significant better outcome in Group A than in Group B in terms of success rate of first exploration, duration of operation, intraoperative hemorrhage, postoperative hospitalization and the incidence of complications

  14. Clinical findings and treatment in cattle with caecal dilatation

    PubMed Central

    2012-01-01

    Background This retrospective study describes the clinical and laboratory findings, treatment and outcome of 461 cattle with caecal dilatation. Results The general condition and demeanor were abnormal in 93.1% of cases, and 32.1% of the patients had colic. Ruminal motility was reduced or absent in 78.3% of cattle. In 82.6% of cases, swinging and/or percussion auscultation were positive on the right side, and 82.4% had little or no faeces in the rectum. Caecal dilatation could be diagnosed via rectal palpation in 405 (88.0%) cattle. There was caudal displacement of the dilated caecum in 291 patients, torsion around the longitudinal axis in 20 and retroflexion in 94. The most important laboratory finding was hypocalcaemia, which occurred in 85.1% of cases. Of the 461 cattle, 122 (26.5%) initially received conservative therapy (intravenous fluids, neostigmine, calcium borogluconate) and 329 (71.4%) underwent surgical treatment. Ten patients were slaughtered or euthanased after the initial physical examination. Of the 122 cattle that received conservative treatment, 42 did not respond after one to two days of therapy and required surgical treatment. The final number of cattle that were operated was 371 (80.5%). Because of a grave prognosis, 24 cases were euthanased or slaughtered intraoperatively. Another 24 cattle did not respond to one or more operations and were euthanased or slaughtered. Of the 461 patients, 403 (87.4%) responded to either conservative or surgical treatment and were cured, and 58 were euthanased or slaughtered. Conclusions Caecal dilatation can usually be diagnosed based on clinical findings and treated conservatively or surgically. Swinging and percussion auscultation as well as rectal examination are important diagnostic tools. Conservative treatment is not rewarding in cattle considered surgical candidates with suspected caecal torsion or retroflexion and surgery should not be delayed in these patients. PMID:22656369

  15. Is there cosmological time dilation in gamma-ray bursts?

    NASA Technical Reports Server (NTRS)

    Band, David L.

    1994-01-01

    Norris et al. report that the temporal structure of faint gamma-ray bursts is longer than that of bright bursts, as expected for time dilation in the cosmological models of burst origin. I show that the observed trends can easily be produced by a burst luminosity function and thus may not result from cosmological effects. A cosmological signature may be present, but the tests Norris et al. present are not powerful enough to detect these signatures.

  16. Motor unit number in a small facial muscle, dilator naris.

    PubMed

    Patel-Khurana, Nilam; Fregosi, Ralph F

    2015-10-01

    A loss of functioning motor units underlies many neuromuscular disorders. The facial nerve innervates the muscles of facial expression, including nasal muscles, which also play an important role in the regulation of airflow resistance. It is difficult to accurately assess motor unit number in the facial muscles, because the muscles are difficult to activate in isolation. Here, we apply the manual McComas method to estimate the number of motor units in a nasal dilator muscle. EMG of the dilator naris was recorded during graded stimulation of the zygomatic branch of the facial nerve in 26 subjects (12 males and 14 females), aged 20-41 years. Each subject was studied twice, on separate days, to estimate method reproducibility. As a check on our use of the McComas method, we also estimated motor unit number in the first dorsal interosseus muscle (FDI) of six subjects, as the muscle is also small and has been studied with the McComas method. Reproducibility was evaluated with a rigorous statistical approach, the Bland-Altman procedure. We estimate that dilator naris is composed of 75 ± 15.6 (SD) motor units, compared to 144 ± 35.5 in FDI. The coefficient of variation for test-retest reproducibility of dilator naris motor unit estimates was 29.6 %, similar to separate-day reproducibility reported for other muscles. Recording and stimulation were done with surface electrodes, and the recordings were of high quality and reproducible. This simple technique could be applied clinically to track motor neuron loss and to monitor facial nerve integrity.

  17. Surgical Aortic Valvuloplasty Versus Balloon Aortic Valve Dilatation in Children.

    PubMed

    Donald, Julia S; Konstantinov, Igor E

    2016-09-01

    Balloon aortic valve dilatation (BAD : is assumed to provide the same outcomes as surgical aortic valvuloplasty (SAV). However, the development of precise modern surgical valvuloplasty techniques may result in better long-term durability of the aortic valve repair. This review of the recent literature suggests that current SAV provides a safe and durable repair. Furthermore, primary SAV appears to have greater freedom from reintervention and aortic valve replacement when compared to BAD. PMID:27587493

  18. Gastric Dilatation and Volvulus in a Red Panda (Ailurus fulgens)

    PubMed Central

    Neilsen, Colleen; Mans, Christoph; Colopy, Sara A.

    2014-01-01

    A 12-year-old male red panda (Ailurus fulgens) was evaluated for acute onset inappetance, staggering, collapse, and tachypnea. Gastric dilatation and volvulus (GDV) was diagnosed by radiography, abdominal ultrasonography, and exploratory celiotomy. Torsion of the stomach was corrected and an incisional gastropexy performed to prevent recurrence. No organs were devitalized, no other abnormalities detected, and the red panda recovered fully within 72 hours. PMID:24467661

  19. Motor unit number in a small facial muscle, dilator naris

    PubMed Central

    Patel-Khurana, Nilam; Fregosi, Ralph F.

    2015-01-01

    A loss of functioning motor units underlies many neuromuscular disorders. The facial nerve innervates the muscles of facial expression, including nasal muscles, which also play an important role in the regulation of airflow resistance. It is difficult to accurately assess motor unit number in the facial muscles, because the muscles are difficult to activate in isolation. Here we apply the manual McComas method to estimate the number of motor units in a nasal dilator muscle. EMG of the dilator naris was recorded during graded stimulation of the zygomatic branch of the facial nerve in 26 subjects (12 M/14 F), aged 20–41 years. Each subject was studied twice, on separate days, to estimate method reproducibility. As a check on our use of the McComas method, we also estimated motor unit number in the first dorsal interosseus muscle (FDI) of 6 subjects, as the muscle is also small, and has been studied with the McComas method. Reproducibility was evaluated with a rigorous statistical approach, the Bland-Altman procedure. We estimate that dilator naris is composed of 75 ±15.6 (SD) motor units, compared to 144 ± 35.5 in FDI. The coefficient of variation for test-retest reproducibility of dilator naris motor unit estimates was 29.6%, similar to separate-day reproducibility reported for other muscles. Recording and stimulation were done with surface electrodes, and the recordings were of high quality and reproducible. This simple technique could be applied clinically to track motor neuron loss, and to monitor facial nerve integrity. PMID:26169101

  20. Ring cycle for dilating and constricting the nuclear pore

    PubMed Central

    Solmaz, Sozanne R.; Blobel, Günter; Melčák, Ivo

    2013-01-01

    We recently showed that the three “channel” nucleoporins, Nup54, Nup58, and Nup62, interact with each other through only four distinct sites and established the crystal structures of the two resulting “interactomes,” Nup54•Nup58 and Nup54•Nup62. We also reported instability of the Nup54•Nup58 interactome and previously determined the atomic structure of the relevant Nup58 segment by itself, demonstrating that it forms a twofold symmetric tetramer. Here, we report the crystal structure of the relevant free Nup54 segment and show that it forms a tetrameric, helical bundle that is structurally “conditioned” for instability by a central patch of polar hydrogen-bonded residues. Integrating these data with our previously reported results, we propose a “ring cycle” for dilating and constricting the nuclear pore. In essence, three homooligomeric rings, one consisting of eight modules of Nup58 tetramers, and two, each consisting of eight modules of Nup54 tetramers, are stacked in midplane and characterize a constricted pore of 10- to 20-nm diameter. In going to the dilated state, segments of one Nup58 and two Nup54 tetrameric modules reassort into a dodecameric module, eight of which form a single, heterooligomeric midplane ring, which is flexible in a diameter range of 40–50 nm. The ring cycle would be regulated by phenylalanine–glycine regions (“FG repeats”) of channel nups. Akin to ligand-gated channels, the dilated state of the midplane ring may be stabilized by binding of [cargo•transport-factor] complexes to FG repeats, thereby linking the ratio of constricted to dilated nuclear pores to cellular transport need. PMID:23479651

  1. 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. PMID:25279611

  2. Dilated odontoma: A report of two cases from a radiological perspective

    PubMed Central

    Jayachandran, S.; Kayal, L.; Sharma, Aatman; Priyanka, Khobre

    2016-01-01

    Dilated odontoma is the most extreme form of dens invaginatus. The lesion appears as a roughly spherical mass that does not resemble a tooth but in a way appears tooth - like on radiographs due to somewhat similar radiodensity. The lesion is mostly spherical in appearance and hence the term “dilated.” Occasionally, we come across cases of simultaneous pathologies. Here, we report two cases of a dilated odontoma one of which is associated with dentigerous cyst and in other case dilated odontoma pushing the maxillary sinus superiorly. Histologically, the mass was composed of dentinal tubules. These morphological and histological features are compatible with those of a dilated odontoma. PMID:27041914

  3. Anesthetic management of hysterosalpingooophorectomy in a case with severe idiopathic dilated cardiomyopathy.

    PubMed

    Kaya, Cengiz; Koksal, Ersin; Ustun, Yasemin Burcu; Semizoglu, Yasemin; Yilmaz, Nurullah

    2014-01-01

    Idiopathic dilated cardiomyopathy is a primary myocardial disease with unknown aetiology. This disease follows a prospective course that is characterized by ventricular dilation and impaired myocardial dilation. Congestive heart failure and malignant arrhythmias are the most widespread complications. The incidence of idiopathic dilated cardiomyopathy in the general population is 5-8/100.000. Because of the increased risks of perioperative complications, anesthetic management of this disease requires the application of a specific technique. This case report demonstrates the application of successful regional anesthetic management (thoracic epidural anesthesia) in a patient who had been diagnosed with severe idiopathic dilated cardiomyopathy. PMID:24937943

  4. Dilated odontoma: A report of two cases from a radiological perspective.

    PubMed

    Jayachandran, S; Kayal, L; Sharma, Aatman; Priyanka, Khobre

    2016-01-01

    Dilated odontoma is the most extreme form of dens invaginatus. The lesion appears as a roughly spherical mass that does not resemble a tooth but in a way appears tooth - like on radiographs due to somewhat similar radiodensity. The lesion is mostly spherical in appearance and hence the term "dilated." Occasionally, we come across cases of simultaneous pathologies. Here, we report two cases of a dilated odontoma one of which is associated with dentigerous cyst and in other case dilated odontoma pushing the maxillary sinus superiorly. Histologically, the mass was composed of dentinal tubules. These morphological and histological features are compatible with those of a dilated odontoma. PMID:27041914

  5. Dilated odontoma: A report of two cases from a radiological perspective.

    PubMed

    Jayachandran, S; Kayal, L; Sharma, Aatman; Priyanka, Khobre

    2016-01-01

    Dilated odontoma is the most extreme form of dens invaginatus. The lesion appears as a roughly spherical mass that does not resemble a tooth but in a way appears tooth - like on radiographs due to somewhat similar radiodensity. The lesion is mostly spherical in appearance and hence the term "dilated." Occasionally, we come across cases of simultaneous pathologies. Here, we report two cases of a dilated odontoma one of which is associated with dentigerous cyst and in other case dilated odontoma pushing the maxillary sinus superiorly. Histologically, the mass was composed of dentinal tubules. These morphological and histological features are compatible with those of a dilated odontoma.

  6. Noncompaction and Dilated Cardiomyopathy in a Patient with Schizophrenia

    PubMed Central

    Stöllberger, Claudia

    2016-01-01

    Objectives. Psychosis and left ventricular hypertrabeculation (or noncompaction) (LVHT) have not been described in the same patient. Here we report a patient with a long-term history of schizophrenia who was later diagnosed with dilated cardiomyopathy (dCMP) and LVHT. Case Report. A 47-year-old Caucasian male developed nondifferentiated schizophrenia at the age of 26 y. Since the age of 33 y he was regularly drinking alcohol. At the age of 47 y he developed heart failure. Transthoracic echocardiography showed an enlarged left ventricle, reduced systolic function, and surprisingly LVHT in the apical segment. Additionally, the left atrium was enlarged, the right ventricular cavities were mildly enlarged, and there were pulmonary hypertension and a small pericardial effusion. Cardiac MRI confirmed the echocardiographic findings. Since coronary angiography was normal, dilated cardiomyopathy was additionally diagnosed. Since he was taking clozapine during years, dilated cardiomyopathy could be due to not only alcohol consumption but also the long-term neuroleptic medication. Conclusions. LVHT may be associated with nondifferentiated psychosis. Management of LVHT is challenging in patients with psychosis due to poor compliance and adherence of these patients. Patients with LVHT and psychosis need particular attention since they usually take cardiotoxic drugs for a long time, which may further deteriorate the prognosis of LVHT. PMID:27547471

  7. Case report of a dilated odontome in the posterior mandible

    PubMed Central

    Almeida, Bruno; Silva, António; Pereira, Miguel; Silva, Mariana; Nunes, Stephanie

    2016-01-01

    Introduction Dens invaginatus (dens in dente) is a developmental malformation resulting from an invagination of enamel organ into the dental papilla, beginning at the crown and sometimes extending into the root before calcification occurs. Dilated odontome is the most extreme form of dens invaginatus and it is extremely rare in the posterior mandible. Presentation of case A 47 years old female patient with occasional episodes of diffuse pain and discomfort in the left posterior mandibular region. The extra-oral examination showed slight facial asymmetry. Panoramic and intra-oral X-rays show an intraosseous circular formation with radiopaque external limits and radiolucent interior. Discussion Computerized tomography scan reveals the bone integrity around the formation, as well as the independence of the neuro-vascular structures of the region. The most likely diagnostic option was dilated odontome. The enucleation procedure was carried out, and the fragments were sent to histopathological examination that revealed a diagnosis consistent with a dilated odontome. Conclusion In this case, the conservative surgical approach after planning was effective and predictable in the treatment of the pathology and patient symptoms without major complications. PMID:26780470

  8. The analysis and modeling of dilatational terms in compressible turbulence

    NASA Technical Reports Server (NTRS)

    Sarkar, S.; Erlebacher, G.; Hussaini, M. Y.; Kreiss, H. O.

    1989-01-01

    It is shown that the dilatational terms that need to be modeled in compressible turbulence include not only the pressure-dilatation term but also another term - the compressible dissipation. The nature of these dilatational terms in homogeneous turbulence is explored by asymptotic analysis of the compressible Navier-Stokes equations. A non-dimensional parameter which characterizes some compressible effects in moderate Mach number, homogeneous turbulence is identified. Direct numerical simulations (DNS) of isotropic, compressible turbulence are performed, and their results are found to be in agreement with the theoretical analysis. A model for the compressible dissipation is proposed; the model is based on the asymptotic analysis and the direct numerical simulations. This model is calibrated with reference to the DNS results regarding the influence of compressibility on the decay rate of isotropic turbulence. An application of the proposed model to the compressible mixing layer has shown that the model is able to predict the dramatically reduced growth rate of the compressible mixing layer.

  9. Regulation of landslide motion by dilatancy and pore pressure feedback

    USGS Publications Warehouse

    Iverson, R.M.

    2005-01-01

    A new mathematical model clarifies how diverse styles and rates of landslide motion can result from regulation of Coulomb friction by dilation or contraction of water-saturated basal shear zones. Normalization of the model equations shows that feedback due to coupling between landslide motion, shear zone volume change, and pore pressure change depends on a single dimensionless parameter ??, which, in turn, depends on the dilatancy angle ?? and the intrinsic timescales for pore pressure generation and dissipation. If shear zone soil contracts during slope failure, then ?? 0, and negative feedback permits slow, steady landslide motion to occur while positive pore pressure is supplied by rain infiltration. Steady state slip velocities v0 obey v0 = -(K/??) p*e, where K is the hydraulic conductivity and p*e is the normalized (dimensionless) negative pore pressure generated by dilation. If rain infiltration and attendant pore pressure growth continue unabated, however, their influence ultimately overwhelms the stabilizing influence of negative p*e. Then, unbounded landslide acceleration occurs, accentuated by an instability that develops if ?? diminishes as landslide motion proceeds. Nonetheless, numerical solutions of the model equations show that slow, nearly steady motion of a clay-rich landslide may persist for many months as a result of negative pore pressure feedback that regulates basal Coulomb friction. Similarly stabilized motion is less likely to occur in sand-rich landslides that are characterized by weaker negative feedback.

  10. A two-phase solid/fluid model for dense granular flows including dilatancy effects

    NASA Astrophysics Data System (ADS)

    Mangeney, Anne; Bouchut, Francois; Fernandez-Nieto, Enrique; Koné, El-Hadj; Narbona-Reina, Gladys

    2016-04-01

    Describing grain/fluid interaction in debris flows models is still an open and challenging issue with key impact on hazard assessment [{Iverson et al.}, 2010]. 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 [{Bouchut et al.}, 2016]. The model is derived from a 3D two-phase model proposed by {Jackson} [2000] based on the 4 equations of mass and momentum conservation within the two phases. This system has 5 unknowns: the solid and fluid velocities, the solid and fluid pressures and the solid volume fraction. As a result, an additional equation inside the mixture is necessary to close the system. Surprisingly, this issue is inadequately accounted for in the models that have been developed on the basis of Jackson's work [{Bouchut et al.}, 2015]. In particular, {Pitman and Le} [2005] replaced this closure simply by imposing an extra boundary condition at the surface of the flow. When making a shallow expansion, this condition can be considered as a closure condition. However, the corresponding model cannot account for a dissipative energy balance. We propose here an approach to correctly deal with the thermodynamics of Jackson's model by closing the mixture equations by a weak compressibility relation following {Roux and Radjai} [1998]. 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

  11. Blunted flow-mediated responses and diminished nitric oxide synthase expression in lymphatic thoracic ducts of a rat model of metabolic syndrome.

    PubMed

    Zawieja, Scott D; Gasheva, Olga; Zawieja, David C; Muthuchamy, Mariappan

    2016-02-01

    Shear-dependent inhibition of lymphatic thoracic duct (TD) contractility is principally mediated by nitric oxide (NO). Endothelial dysfunction and poor NO bioavailability are hallmarks of vasculature dysfunction in states of insulin resistance and metabolic syndrome (MetSyn). We tested the hypothesis that flow-dependent regulation of lymphatic contractility is impaired under conditions of MetSyn. We utilized a 7-wk high-fructose-fed male Sprague-Dawley rat model of MetSyn and determined the stretch- and flow-dependent contractile responses in an isobaric ex vivo TD preparation. TD diameters were tracked and contractile parameters were determined in response to different transmural pressures, imposed flow, exogenous NO stimulation by S-nitro-N-acetylpenicillamine (SNAP), and inhibition of NO synthase (NOS) by l-nitro-arginine methyl ester (l-NAME) and the reactive oxygen species (ROS) scavenging molecule 4-hydroxy-tempo (tempol). Expression of endothelial NO synthase (eNOS) in TD was determined using Western blot. Approximately 25% of the normal flow-mediated inhibition of contraction frequency was lost in TDs isolated from MetSyn rats despite a comparable SNAP response. Inhibition of NOS with l-NAME abolished the differences in the shear-dependent contraction frequency regulation between control and MetSyn TDs, whereas tempol did not restore the flow responses in MetSyn TDs. We found a significant reduction in eNOS expression in MetSyn TDs suggesting that diminished NO production is partially responsible for impaired flow response. Thus our data provide the first evidence that MetSyn conditions diminish eNOS expression in TD endothelium, thereby affecting the flow-mediated changes in TD lymphatic function.

  12. Early Gastric Cancer Recurrence Following Curative Resection Presenting as Biliary Tract Dilatation, Pancreatic Duct Dilatation and Intestinal Wall Thickening.

    PubMed

    Kato, Hiroyuki; Ito, Yukiko; Tanaka, Eri; Noguchi, Kensaku; Yamamoto, Shinzo; Taniguchi, Hiroyoshi; Yoshida, Hideo; Kumasaka, Toshio; Nakata, Ryo

    2016-01-01

    Early gastric cancer, especially cancer confined to the mucosa (stage T1a), is known to have a high cure rate with rare recurrence. We herein report the case of a 40-year-old female who initially presented with biliary tract dilatation, pancreatic duct dilatation and intestinal wall thickening 3 years after curative resection of pT1aN0 stage gastric cancer. The intestinal resection specimen revealed tumor cells spreading through the subserosa to the submucosa sparing mucosal membrane, which made exploratory laparotomy the only approach to confirm the diagnosis. It is always important to be aware of malignancy recurrence and clinicians should not hesitate to choose exploratory laparotomy to avoid any delay in the diagnosis and treatment. PMID:27041158

  13. Intracerebroventricular application of S100B selectively impairs pial arteriolar dilating function in rats.

    PubMed

    Changyaleket, Benjarat; Xu, Haoliang; Vetri, Francesco; Valyi-Nagy, Tibor; Paisansathan, Chanannait; Chong, Zhao Zhong; Pelligrino, Dale A; Testai, Fernando D

    2016-03-01

    S100B is an astrocyte-derived protein that can act through the receptor for advanced glycation endproducts (RAGE) to mediate either "trophic" or "toxic" responses. Its levels increase in many neurological conditions with associated microvascular dysregulation, such as subarachnoid hemorrhage (SAH) and traumatic brain injury. The role of S100B in the pathogenesis of microvasculopathy has not been addressed. This study was designed to examine whether S100B alters pial arteriolar vasodilating function. Rats were randomized to receive (1) artificial cerebrospinal fluid (aCSF), (2) exogenous S100B, and (3) exogenous S100B+the decoy soluble RAGE (sRAGE). S100B was infused intracerebroventricularly (icv) using an osmotic pump and its levels in the CSF were adjusted to achieve a concentration similar to what we observed in SAH. After 48 h of continuous icv infusion, a cranial window/intravital microscopy was applied to animals for evaluation of pial arteriolar dilating responses to sciatic nerve stimulation (SNS), hypercapnia, and topical suffusion of vasodilators including acetylcholine (ACh), s-nitroso-N-acetyl penicillamine (SNAP), or adenosine (ADO). Pial arteriolar dilating responses were calculated as the percentage change of arteriolar diameter in relation to baseline. The continuous S100B infusion for 48 h was associated with reduced responses to the neuronal-dependent vasodilator SNS (p<0.05) and the endothelial-dependent vasodilator ACh (p<0.05), compared to controls. The inhibitory effects of S100B were prevented by sRAGE. On the other hand, S100B did not alter the responses elicited by vascular smooth muscle cell-dependent vasodilators, namely hypercapnia, SNAP, or ADO. These findings indicate that S100B regulates neuronal and endothelial dependent cerebral arteriolar dilation and suggest that this phenomenon is mediated through RAGE-associated pathways. PMID:26773687

  14. Is Endoscopic Papillary Large Balloon Dilation Safe for Treating Large CBD Stones?

    PubMed Central

    Shim, Chan Sup; Kim, Ji Wan; Lee, Tae Yoon; Cheon, Young Koog

    2016-01-01

    In recent years, endoscopic papillary large balloon dilation (EPLBD) with endoscopic sphincterotomy (EST) has been shown to be an effective technique for the removal of large or difficult common bile duct (CBD) stones, as an alternative to EST. Reviewing the literature published since 2003, it is understood that EPLBD has fewer associated overall complications than EST. Bleeding occurred less frequently with EPLBD than with EST. There was no significant difference in postendoscopic retrograde cholangiopancreatography pancreatitis or perforation. Recent accumulated results of EPLBD with or even without EST suggest that it is a safe and effective procedure for the removal of large or difficult bile duct stones without any additional risk of severe adverse events, when performed under appropriate guidelines. Since use of a larger balloon can tear the sphincter as well as the bile duct, possibly resulting in bleeding and perforation, a balloon size that is equal to or smaller in diameter than the diameter of the native distal bile duct is recommended. The maximum transverse diameter of the stone and the balloon-stone diameter ratio have a tendency to affect the success or failure of complete removal of stones by large balloon dilation to prevent adverse effects such as perforation and bleeding. One should take into account the size of the native bile duct, the size and burden of stones, the presence of stricture of distal bile duct, and the presence of the papilla in or adjacent to a diverticulum. Even though the results of EPLBD indicate that it is a relatively safe procedure in patients with common duct stones with a dilated CBD, the recommended guidelines should be followed strictly for the prevention of major adverse events such as bleeding and perforation. PMID:27488319

  15. Measurement of the Surface Dilatational Viscosity of an Insoluble Surfactant Monolayer at the Air/Water Interface Using a Pendant Drop Apparatus

    NASA Technical Reports Server (NTRS)

    Lorenzo, Jose; Couzis, Alex; Maldarelli, Charles; Singh, Bhim S. (Technical Monitor)

    2000-01-01

    When a fluid interface with surfactants is at rest, the interfacial stress is isotropic (as given by the equilibrium interfacial tension), and is described by the equation of state which relates the surface tension to the surfactant surface concentration. When surfactants are subjected to shear and dilatational flows, flow induced interaction of the surfactants; can create interfacial stresses apart from the equilibrium surface tension. The simplest relationship between surface strain rate and surface stress is the Boussinesq-Scriven constitutive equation completely characterized by three coefficients: equilibrium interfacial tension, surface shear viscosity, and surface dilatational viscosity Equilibrium interfacial tension and surface shear viscosity measurements are very well established. On the other hand, surface dilatational viscosity measurements are difficult because a flow which change the surface area also changes the surfactant surface concentration creating changes in the equilibrium interfacial tension that must be also taken into account. Surface dilatational viscosity measurements of existing techniques differ by five orders of magnitude and use spatially damped surface waves and rapidly expanding bubbles. In this presentation we introduce a new technique for measuring the surface dilatational viscosity by contracting an aqueous pendant drop attached to a needle tip and having and insoluble surfactant monolayer at the air-water interface. The isotropic total tension on the surface consists of the equilibrium surface tension and the tension due to the dilation. Compression rates are undertaken slow enough so that bulk hydrodynamic stresses are small compared to the surface tension force. Under these conditions we show that the total tension is uniform along the surface and that the Young-Laplace equation governs the drop shape with the equilibrium surface tension replaced by the constant surface isotropic stress. We illustrate this technique using

  16. A comparative study of the hypoplasticity and the fabric-dependent dilatant double shearing models for granular materials

    SciTech Connect

    Zhu, H.; Mehrabadi, M.; Massoudi, M.

    2007-04-25

    In this paper, we consider the mechanical response of granular materials and compare the predictions of a hypoplastic model with that of a recently developed dilatant double shearing model which includes the effects of fabric. We implement the constitutive relations of the dilatant double shearing model and the hypoplastic model in the finite element program ABACUS/Explicit and compare their predictions in the triaxial compression and cyclic shear loading tests. Although the origins and the constitutive relations of the double shearing model and the hypoplastic model are quite different, we find that both models are capable of capturing typical behaviours of granular materials. This is significant because while hypoplasticity is phenomenological in nature, the double shearing model is based on a kinematic hypothesis and microstructural considerations, and can easily be calibrated through standard tests.

  17. Aeolian Sand Transport in the Planetary Context: Respective Roles of Aerodynamic and Bed-Dilatancy Thresholds

    NASA Astrophysics Data System (ADS)

    Marshall, J. R.; Borucki, J.; Bratton, C.

    1999-09-01

    energy of the "percussive" grain decreases (by decrease in velocity or mass). Thus, the mass of the "repercussive" grain population that is ejected from the impact site becomes a function of the scale of the stress field in relation to the scale of the bed material (self-similarity being applicable if both bed size and energy are simultaneously adjusted). In other words, in a very high energy aeolian system where an aerodynamically raised grain can ballistically raise many more grains, the amount of material lifted into the wind becomes largely a function of a dilatancy threshold. If this threshold is exceeded, grains are repercussively injected into the saltation cloud. The "dilatancy threshold" may be defined in terms of the saltation percussive force required to convert the bed, through elastic response, from a closed to an open packing system. If open packing cannot be created, the grains cannot escape from the impact site, even though the elastic deformation and percussive force may be able to reorganize the grains with respect to one another. As the crossbow experiments showed, for an ever-increasing bed grain size, a point is reached when no material can be moved because the energy of the percussive grain is insufficient to dilate the relatively coarse bed. Although this seems to be stating the obvious -- that too little energy will not cause the bed to splash -- the consequences of exceeding the "splash threshold" by dilatancy are not so obvious for high-energy aeolian transport. It is noted that the force required to elastically dilate the bed has to overcome Coulombic grain attractions such as dipole-dipole coupling, dielectric, monopole, contact-induced dipole attractions, van der Waals forces, molecular monolayer capillary forces, as well as the mechanical interlocking frictional resistance of the grains. On Mars, it is predicted that the dilatancy threshold may be the prime control of grain flux. Additional information is contained in the original.

  18. Aeolian Sand Transport in the Planetary Context: Respective Roles of Aerodynamic and Bed-Dilatancy Thresholds

    NASA Technical Reports Server (NTRS)

    Marshall, J. R.; Borucki, J.; Bratton, C.

    1999-01-01

    energy of the "percussive" grain decreases (by decrease in velocity or mass). Thus, the mass of the "repercussive" grain population that is ejected from the impact site becomes a function of the scale of the stress field in relation to the scale of the bed material (self-similarity being applicable if both bed size and energy are simultaneously adjusted). In other words, in a very high energy aeolian system where an aerodynamically raised grain can ballistically raise many more grains, the amount of material lifted into the wind becomes largely a function of a dilatancy threshold. If this threshold is exceeded, grains are repercussively injected into the saltation cloud. The "dilatancy threshold" may be defined in terms of the saltation percussive force required to convert the bed, through elastic response, from a closed to an open packing system. If open packing cannot be created, the grains cannot escape from the impact site, even though the elastic deformation and percussive force may be able to reorganize the grains with respect to one another. As the crossbow experiments showed, for an ever-increasing bed grain size, a point is reached when no material can be moved because the energy of the percussive grain is insufficient to dilate the relatively coarse bed. Although this seems to be stating the obvious -- that too little energy will not cause the bed to splash -- the consequences of exceeding the "splash threshold" by dilatancy are not so obvious for high-energy aeolian transport. It is noted that the force required to elastically dilate the bed has to overcome Coulombic grain attractions such as dipole-dipole coupling, dielectric, monopole, contact-induced dipole attractions, van der Waals forces, molecular monolayer capillary forces, as well as the mechanical interlocking frictional resistance of the grains. On Mars, it is predicted that the dilatancy threshold may be the prime control of grain flux. Additional information is contained in the original.

  19. Self-powered monitoring of repeated head impacts using time-dilation energy measurement circuit.

    PubMed

    Feng, Tao; Aono, Kenji; Covassin, Tracey; Chakrabartty, Shantanu

    2015-04-01

    Due to the current epidemic levels of sport-related concussions (SRC) in the U.S., there is a pressing need for technologies that can facilitate long-term and continuous monitoring of head impacts. Existing helmet-sensor technology is inconsistent, inaccurate, and is not economically or logistically practical for large-scale human studies. In this paper, we present the design of a miniature, battery-less, self-powered sensor that can be embedded inside sport helmets and can continuously monitor and store different spatial and temporal statistics of the helmet impacts. At the core of the proposed sensor is a novel time-dilation circuit that allows measurement of a wide-range of impact energies. In this paper an array of linear piezo-floating-gate (PFG) injectors has been used for self-powered sensing and storage of linear and rotational head-impact statistics. The stored statistics are then retrieved using a plug-and-play reader and has been used for offline data analysis. We report simulation and measurement results validating the functionality of the time-dilation circuit for different levels of impact energies. Also, using prototypes of linear PFG integrated circuits fabricated in a 0.5 μm CMOS process, we demonstrate the functionality of the proposed helmet-sensors using controlled drop tests. PMID:25838527

  20. Moving Phones Tick Slower: Creating an Android App to Demonstrate Time Dilation

    NASA Astrophysics Data System (ADS)

    Underwood, Bret; Zhai, Yunxiao

    2016-05-01

    Smartphones and tablets are packed with sensors that allow us to take experimental data, essentially making them mobile physics labs. Apps exist that make it easy to capture and analyze data from these sensors, allowing users to study diverse phenomena such as free fall acceleration, the speed of sound, radioactivity, and many others. Commonly, the use of apps in the physics classroom focuses on existing apps rather than on the creation of apps themselves. This is for a good reason-writing an app usually requires advanced knowledge of programming languages and experience with app design. These skills are generally regarded as beyond the typical physics student. However, there are app development environments, such as MIT App Inventor 2 for Android, which make the process of creating an app and utilizing the sensors much more accessible to students. Putting the ability to create and configure apps within the reach of students can also help integrate computation into the curriculum. In this article, we discuss our creation of an Android app, Time Dilation Calculator, done as part of a senior undergraduate capstone project, which uses App Inventor and a mobile device's global positioning system (GPS) receiver to calculate the time dilation effect of special relativity.

  1. Dilated cardiomyopathy in mice deficient for the lysosomal cysteine peptidase cathepsin L

    PubMed Central

    Stypmann, Jörg; Gläser, Kerstin; Roth, Wera; Tobin, Desmond J.; Petermann, Ivonne; Matthias, Rainer; Mönnig, Gerold; Haverkamp, Wilhelm; Breithardt, Günter; Schmahl, Wolfgang; Peters, Christoph; Reinheckel, Thomas

    2002-01-01

    Dilated cardiomyopathy is a frequent cause of heart failure and is associated with high mortality. Progressive remodeling of the myocardium leads to increased dimensions of heart chambers. The role of intracellular proteolysis in the progressive remodeling that underlies dilated cardiomyopathy has not received much attention yet. Here, we report that the lysosomal cysteine peptidase cathepsin L (CTSL) is critical for cardiac morphology and function. One-year-old CTSL-deficient mice show significant ventricular and atrial enlargement that is associated with a comparatively small increase in relative heart weight. Interstitial fibrosis and pleomorphic nuclei were found in the myocardium of the knockout mice. By electron microscopy, CTSL-deficient cardiomyocytes contained multiple large and apparently fused lysosomes characterized by storage of electron-dense heterogeneous material. Accordingly, the assessment of left ventricular function by echocardiography revealed severely impaired myocardial contraction in the CTSL-deficient mice. In addition, echocardiographic and electrocardiographic findings to some degree point to left ventricular hypertrophy that most likely represents an adaptive response to cardiac impairment. The histomorphological and functional alterations of CTSL-deficient hearts result in valve insufficiencies. Furthermore, abnormal heart rhythms, like supraventricular tachycardia, ventricular extrasystoles, and first-degree atrioventricular block, were detected in the CTSL-deficient mice. PMID:11972068

  2. The effect of dilatancy on velocity anisotropy in Westerly granite

    NASA Technical Reports Server (NTRS)

    Soga, N.; Mizutani, H.; Spetzler, H.; Martin, R. J., III

    1978-01-01

    Jacketed samples of Westerly granite were fractured at confining pressures up to 1 kbar, and compressional and horizontally as well as vertically polarized shear velocities were measured in orthogonal directions perpendicular to the compression axis. Changes occurring with increased strain are described, and the velocity data were analyzed by application of the Anderson et al (1974) approach. Observed and calculated velocities are found to be in good agreement, and the degree of dilatancy was determined from the differences between the strains measured perpendicularly to the compression axis and the estimated elastic strains in those directions.

  3. Dilational processes accompanying earthquakes in the Long Valley Caldera

    USGS Publications Warehouse

    Dreger, Douglas S.; Tkalcic, Hrvoje; Johnston, M.

    2000-01-01

    Regional distance seismic moment tensor determinations and broadband waveforms of moment magnitude 4.6 to 4.9 earthquakes from a November 1997 Long Valley Caldera swarm, during an inflation episode, display evidence of anomalous seismic radiation characterized by non-double couple (NDC) moment tensors with significant volumetric components. Observed coseismic dilation suggests that hydrothermal or magmatic processes are directly triggering some of the seismicity in the region. Similarity in the NDC solutions implies a common source process, and the anomalous events may have been triggered by net fault-normal stress reduction due to high-pressure fluid injection or pressurization of fluid-saturated faults due to magmatic heating.

  4. Commissural detachment and Valsalva sinus dilatation after implantation of Prima Plus stentless valve with full root technique.

    PubMed

    Ohira, Suguru; Doi, Kiyoshi; Okawa, Kazunari; Yaku, Hitoshi

    2016-06-01

    The stentless aortic bioprosthesis has been used because of its excellent hemodynamics and few valve-related complications. We report a case of redo aortic root replacement for severe aortic regurgitation and dilatation of the Valsalva sinus 7 years after the implantation of a Prima Plus aortic root bioprosthesis (Edwards LifeScience, Irvine, CA, USA) using a full root technique. Intraoperative findings showed the complete detachment of the commissure between the left and non-coronary cusps, and Valsalva sinus dilatation of the porcine aortic root bioprosthesis. Redo aortic root replacement with a 23-mm porcine bioprosthesis and 28-mm straight graft was performed. There were no findings of intimal tear, suture dehiscence, degeneration, and perforation of the bioprosthesis. Such complications associated with the Edwards Prima Plus aortic root bioprosthesis were rarely reported. Commissural detachment of a porcine stentless aortic bioprosthesis can occur; thus, careful follow-up involving echocardiography and computed tomography is necessary. PMID:25341962

  5. Balloon catheter dilatation of coarctation of the aorta in young infants.

    PubMed Central

    Finley, J P; Beaulieu, R G; Nanton, M A; Roy, D L

    1983-01-01

    In four young infants with symptomatic coarctation of the aorta the narrow aortic segment was dilated with a balloon angioplasty catheter. Three of the infants also had appreciable heart defects and one infant had undergone surgery before and had had one previous dilatation. Dilatation was well tolerated and good femoral pulses appeared in all cases, but these disappeared over one to seven days. Despite this, two patients showed some symptomatic improvement over four months. One patient died after perforation of the aorta by an angiographic catheter after dilatation. Relieving coarctation in young infants by catheter dilatation appears incomplete, but it may give symptomatic improvement. Further trial of the procedure will determine whether patients who have undergone surgery and those who have not may benefit. Careful attention to technique and avoidance of manipulations after dilatation are essential if complications are to be avoided. Images PMID:6227327

  6. [Effects of sex hormone on the dilatation of urinary tubule and acidophil body in NON mice].

    PubMed

    Sahata, H; Suzuki, S; Ago, A; Mifune, H; Sakamoto, H

    1994-10-01

    The influences of sex hormones on the dilatation of the urinary tubules and acidophil bodies were histologically investigated in NON (Non-Obese Non-diabetic) mice. Although the dilatation of the proximal tubules and acidophil bodies in NON mice were observed only in female but not in male, a slight dilatation and a few bodies were also observed in castrated male NON mice. Moreover, in ovariectomized female NON mice the dilatation and bodies were less compared with intact female NON mice. Estradiol administration induced prominent dilatation and numerous acidophil bodies, while the administration of testosterone showed a complete preventive effect. Therefore, it is suggested that the dilatation of the tubules and the acidophil bodies can be profoundly influenced by sex hormones. PMID:7805803

  7. Prograde dilatation with Tucker bougies: a technique for managing postoperative rectal strictures.

    PubMed

    Gamliel, Z; Wesson, D

    1991-11-01

    Postoperative rectal stricture is an occasional complication of abdominoperineal pull-through and low anterior resection of the rectum. Although the causes and pathogenesis of this phenomenon are poorly understood, various techniques for stricture dilatation have been described. In this article, we present two cases of severe postoperative rectal strictures that were not amenable to conventional methods of dilatation but were successfully managed by a technique of dilatation using Tucker bougies without general anesthesia.

  8. Sinus Balloon Dilation as Treatment for Acute Sphenoid Sinusitis with Impaired Vision for a Child.

    PubMed

    Zhao, Yin; Chen, Kangbing; Wang, Zonggui

    2016-01-01

    This paper is about sinus balloon dilatation in treatment of acute left sphenoid sinusitis with left impaired vision in a child. Balloon catheter dilatation (BCD) of the sinus ostia is a new technique. It has been shown to be a minimally invasive technique to manage chronic sinusitis. However, this method is rarely used in the treatment of acute sinusitis. So far, we know of no reported cases of sinus balloon dilatation in treatment of this case, especially for children.

  9. Dilated cardiomyopathy with Graves disease in a young child.

    PubMed

    Choi, Yu Jung; Jang, Jun Ho; Park, So Hyun; Oh, Jin-Hee; Koh, Dae Kyun

    2016-06-01

    Graves disease (GD) can lead to complications such as cardiac arrhythmia and heart failure. Although dilated cardiomyopathy (DCMP) has been occasionally reported in adults with GD, it is rare in children. We present the case of a 32-month-old boy with DCMP due to GD. He presented with irritability, vomiting, and diarrhea. He also had a history of weight loss over the past few months. On physical examination, he had tachycardia without fever, a mild diffuse goiter, and hepatomegaly. The chest radiograph showed cardiomegaly with pulmonary edema, while the echocardiography revealed a dilated left ventricle with an ejection fraction (EF) of 28%. The thyroid function test (TFT) showed elevated serum T3 and decreased thyroid stimulating hormone (TSH) levels. The TSH receptor autoantibody titer was elevated. He was diagnosed with DCMP with GD; treatment with methylprednisolone, diuretics, inotropics, and methimazole was initiated. The EF improved after the TFT normalized. At follow-up several months later, although the TFT results again showed evidence of hyperthyroidism, his EF had not deteriorated. His cardiac function continues to remain normal 1.5 months after treatment was started, although he still has elevated T3 and high TSH receptor antibody titer levels due to poor compliance with drug therapy. To summarize, we report a young child with GD-induced DCMP who recovered completely with medical therapy and, even though the hyperthyroidism recurred several months later, there was no relapse of the DCMP. PMID:27462586

  10. Reversible transition from a hypertrophic to a dilated cardiomyopathy

    PubMed Central

    Spillmann, Frank; Kühl, Uwe; Van Linthout, Sophie; Dominguez, Fernando; Escher, Felicitas; Schultheiss, Heinz‐Peter; Pieske, Burkert

    2015-01-01

    Abstract We report the case of a 17‐year‐old female patient with known hypertrophic cardiomyopathy and a Wolff‐Parkinson‐White syndrome. She came to our department for further evaluation of a new diagnosed dilated cardiomyopathy characterized by an enlargement of the left ventricle and a fall in ejection fraction. Clinically, she complained about atypical chest pain, arrhythmic episodes with presyncopal events, and dyspnea (NYHA III) during the last 6 months. Non‐invasive and invasive examinations including magnetic resonance imaging, electrophysiological examinations, and angiography did not lead to a conclusive diagnosis. Therefore, endomyocardial biopsies (EMBs) were taken to investigate whether a specific myocardial disease caused the impairment of the left ventricular function. EMB analysis resulted in the diagnosis of a virus‐negative, active myocarditis. Based on this diagnosis, an immunosuppressive treatment with prednisolone and azathioprine was started, which led to an improvement of cardiac function and symptoms within 3 months after initiating therapy. In conclusion, we show that external stress triggered by myocarditis can induce a reversible transition from a hypertrophic cardiomyopathy to a dilated cardiomyopathy phenotype. This case strongly underlines the need for a thorough and invasive examination of heart failure of unknown causes, including EMB investigations as recommend by the actual ESC position statement.

  11. Dilated cardiomyopathy with Graves disease in a young child

    PubMed Central

    Choi, Yu Jung; Jang, Jun Ho; Oh, Jin-Hee; Koh, Dae Kyun

    2016-01-01

    Graves disease (GD) can lead to complications such as cardiac arrhythmia and heart failure. Although dilated cardiomyopathy (DCMP) has been occasionally reported in adults with GD, it is rare in children. We present the case of a 32-month-old boy with DCMP due to GD. He presented with irritability, vomiting, and diarrhea. He also had a history of weight loss over the past few months. On physical examination, he had tachycardia without fever, a mild diffuse goiter, and hepatomegaly. The chest radiograph showed cardiomegaly with pulmonary edema, while the echocardiography revealed a dilated left ventricle with an ejection fraction (EF) of 28%. The thyroid function test (TFT) showed elevated serum T3 and decreased thyroid stimulating hormone (TSH) levels. The TSH receptor autoantibody titer was elevated. He was diagnosed with DCMP with GD; treatment with methylprednisolone, diuretics, inotropics, and methimazole was initiated. The EF improved after the TFT normalized. At follow-up several months later, although the TFT results again showed evidence of hyperthyroidism, his EF had not deteriorated. His cardiac function continues to remain normal 1.5 months after treatment was started, although he still has elevated T3 and high TSH receptor antibody titer levels due to poor compliance with drug therapy. To summarize, we report a young child with GD-induced DCMP who recovered completely with medical therapy and, even though the hyperthyroidism recurred several months later, there was no relapse of the DCMP. PMID:27462586

  12. Ventricular dilation as an instability of intracranial dynamics

    NASA Astrophysics Data System (ADS)

    Bouzerar, R.; Ambarki, K.; Balédent, O.; Kongolo, G.; Picot, J. C.; Meyer, M. E.

    2005-11-01

    We address the question of the ventricles’ dilation as a possible instability of the intracranial dynamics. The ventricular system is shown to be governed by a dynamical equation derived from first principles. This general nonlinear scheme is linearized around a well-defined steady state which is mapped onto a pressure-volume model with an algebraic effective compliance depending on the ventricles’ geometry, the ependyma’s elasticity, and the cerebrospinal fluid (CSF) surface tension. Instabilities of different natures are then evidenced. A first type of structural instability results from the compelling effects of the CSF surface tension and the elastic properties of the ependyma. A second type of dynamical instability occurs for low enough values of the aqueduct’s conductance. This last case is then shown to be accompanied by a spontaneous ventricle’s dilation. A strong correlation with some active hydrocephalus is evidenced and discussed. The transfer function of the ventricles, compared to a low-pass filter, are calculated in both the stable and unstable regimes and appear to be very different.

  13. Finite-temperature corrections in the dilated chiral quark model

    SciTech Connect

    Kim, Y.; Lee, Hyun Kyu |; Rho, M. |

    1995-03-01

    We calculate the finite-temperature corrections in the dilated chiral quark model using the effective potential formalism. Assuming that the dilaton limit is applicable at some short length scale, we interpret the results to represent the behavior of hadrons in dense and hot matter. We obtain the scaling law, f{sub {pi}}(T)/f{sub {pi}} = m{sub Q}(T)/m{sub Q} {approx_equal} m{sub {sigma}}(T)/m{sub {sigma}}while we argue, using PCAC, that pion mass does not scale within the temperature range involved in our Lagrangian. It is found that the hadron masses and the pion decay constant drop faster with temperature in the dilated chiral quark model than in the conventional linear sigma model that does not take into account the QCD scale anomaly. We attribute the difference in scaling in heat bath to the effect of baryonic medium on thermal properties of the hadrons. Our finding would imply that the AGS experiments (dense and hot matter) and the RHIC experiments (hot and dilute matter) will ``see`` different hadron properties in the hadronization exit phase.

  14. Doxorubicin induced dilated cardiomyopathy in a rabbit model: an update.

    PubMed

    Gava, Fábio N; Zacché, Evandro; Ortiz, Edna M G; Champion, Tatiana; Bandarra, Marcio B; Vasconcelos, Rosemeri O; Barbosa, José C; Camacho, Aparecido A

    2013-02-01

    Dilated cardiomyopathy (DCM) is characterized by chamber dilation and cardiac dysfunction. Because of the poor prognosis, models are needed for the investigation of and development of new therapeutic approaches, as well as stem cell therapy. Doxorubicin (DOX), used as chemotherapeutic agent, is reported to be cumulative cardiotoxic causing DCM. The aim of the study was to investigate the onset of systolic dysfunction using echocardiography in rabbits receiving two different doses of DOX (1mg/kg twice a week and 2 mg/kg once a week). Twenty rabbits were treated with doxorubicin in two different doses for 6 weeks and compared with a control group treated with NaCl 0.9%. The effect of doxorubicin on the myocardium was investigated with histological analysis and scanning electron microscopy of left ventricle (LV), as well as in the interventricular septum (IVS) and right ventricle (RV). The results showed a high mortality rate for rabbits receiving 2 mg/kg once a week. A significant reduction in systolic function was present in animals treated with DOX after 6 weeks, with decreased ejection fraction and shortening fraction. Histology and electron microscopy revealed vacuolization, intracytoplasmic granulation, necrosis and interstitial fibrosis in LV, as well as in the IVS and RV. Doxorubicin induced changes are present in the LV, RV and IVS, and the administration at the dose of 1 mg/kg twice a week for only 6 weeks is safe and sufficient to induce DCM in rabbits.

  15. Central Vein Dilatation Prior to Concomitant Port Implantation

    SciTech Connect

    Krombach, Gabriele A. Plumhans, Cedric; Goerg, Fabian; Guenther, Rolf W.

    2010-04-15

    Implantation of subcutaneous port systems is routinely performed in patients requiring repeated long-term infusion therapy. Ultrasound- and fluoroscopy-guided implantation under local anesthesia is broadly established in interventional radiology and has decreased the rate of complications compared to the surgical approach. In addition, interventional radiology offers the unique possibility of simultaneous management of venous occlusion. We present a technique for recanalization of central venous occlusion and angioplasty combined with port placement in a single intervention which we performed in two patients. Surgical port placement was impossible owing to occlusion of the superior vena cava following placement of a cardiac pacemaker and occlusion of multiple central veins due to paraneoplastic coagulopathy, respectively. In both cases the affected vessel segments were dilated with balloon catheters and the port systems were placed thereafter. After successful dilatation, the venous access was secured with a 25-cm-long, 8-Fr introducer sheath, a subcutaneous pocket prepared, and the port catheter tunneled to the venipuncture site. The port catheter was introduced through the sheath with the proximal end connected to a 5-Fr catheter. This catheter was pulled through the tunnel in order to preserve the tunnel and, at the same time, allow safe removal of the long sheath over the wire. The port system functioned well in both cases. The combination of recanalization and port placement in a single intervention is a straightforward alternative for patients with central venous occlusion that can only be offered by interventional radiology.

  16. Prospective study of outcome in antenatally diagnosed renal pelvis dilatation

    PubMed Central

    Jaswon, M.; Dibble, L.; Puri, S.; Davis, J.; Young, J.; Dave, R.; Morgan, H.

    1999-01-01

    AIMS—To ascertain the outcome associated with antenatal renal pelvis dilatation; to recommend guidelines for postnatal investigation and determine an upper limit of normal for the anterioposterior dimensions of the fetal renal pelvis.
METHODS—Infants whose antenatal ultrasound scan showed a fetal renal pelvis of 5 mm or greater were investigated using postnatal renal tract ultrasound and a micturating cystogram. Isotope studies were also performed, where appropriate.
RESULTS—Vesicoureteric reflux (VUR), the most common diagnosis, was evident in 23/104 (22%). In 14 infants with VUR the postnatal ultrasound scan was normal. There was no evidence of renal scarring or dysplasia in any of the refluxing kidneys. Other diagnoses were pelviureteric junction obstruction, renal dysplasia, and idiopathic dilatation. Antenatal counselling and parental information facilitated postnatal assessment.
CONCLUSIONS—Infants with antenatal renal pelvis measurements of 5 mm or greater should be investigated postnatally, as a significant percentage will have VUR. A normal postnatal ultrasound scan does not preclude the presence of VUR. 

 PMID:10325792

  17. Dermal lymphatic dilation in a mouse model of alopecia areata.

    PubMed

    Sundberg, John P; Pratt, C Herbert; Silva, Kathleen A; Kennedy, Victoria E; Stearns, Timothy M; Sundberg, Beth A; King, Lloyd E; HogenEsch, Harm

    2016-04-01

    Mouse models of various types of inflammatory skin disease are often accompanied by increased dermal angiogenesis. The C3H/HeJ inbred strain spontaneously develops alopecia areata (AA), a cell mediated autoimmune disorder that can be controllably expanded using full thickness skin grafts to young unaffected mice. This provides a reproducible and progressive model for AA in which the vascularization of the skin can be examined. Mice receiving skin grafts from AA or normal mice were evaluated at 5, 10, 15, and 20 weeks after engraftment. Lymphatics are often overlooked as they are small slit-like structures above the hair follicle that resemble artifact-like separation of collagen bundles with some fixatives. Lymphatics are easily detected using lymphatic vessel endothelial hyaluronan receptor 1 (LYVE1) by immunohistochemistry to label their endothelial cells. Using LYVE1, there were no changes in distribution or numbers of lymphatics although they were more prominent (dilated) in the mice with AA. Lyve1 transcripts were not significantly upregulated except at 10 weeks after skin grafting when clinical signs of AA first become apparent. Other genes involved with vascular growth and dilation or movement of immune cells were dysregulated, mostly upregulated. These findings emphasize aspects of AA not commonly considered and provide potential targets for therapeutic intervention.

  18. Dermal lymphatic dilation in a mouse model of alopecia areata.

    PubMed

    Sundberg, John P; Pratt, C Herbert; Silva, Kathleen A; Kennedy, Victoria E; Stearns, Timothy M; Sundberg, Beth A; King, Lloyd E; HogenEsch, Harm

    2016-04-01

    Mouse models of various types of inflammatory skin disease are often accompanied by increased dermal angiogenesis. The C3H/HeJ inbred strain spontaneously develops alopecia areata (AA), a cell mediated autoimmune disorder that can be controllably expanded using full thickness skin grafts to young unaffected mice. This provides a reproducible and progressive model for AA in which the vascularization of the skin can be examined. Mice receiving skin grafts from AA or normal mice were evaluated at 5, 10, 15, and 20 weeks after engraftment. Lymphatics are often overlooked as they are small slit-like structures above the hair follicle that resemble artifact-like separation of collagen bundles with some fixatives. Lymphatics are easily detected using lymphatic vessel endothelial hyaluronan receptor 1 (LYVE1) by immunohistochemistry to label their endothelial cells. Using LYVE1, there were no changes in distribution or numbers of lymphatics although they were more prominent (dilated) in the mice with AA. Lyve1 transcripts were not significantly upregulated except at 10 weeks after skin grafting when clinical signs of AA first become apparent. Other genes involved with vascular growth and dilation or movement of immune cells were dysregulated, mostly upregulated. These findings emphasize aspects of AA not commonly considered and provide potential targets for therapeutic intervention. PMID:26960166

  19. Safety and outcome using endoscopic dilatation for benign esophageal stricture without fluoroscopy

    PubMed Central

    Kabbaj, Nawal; Salihoun, Mouna; Chaoui, Zakia; Acharki, Mohamed; Amrani, Naïma

    2011-01-01

    AIM: To investigate the use of Savary-Gilliard marked dilators in tight esophageal strictures without fluoroscopy. METHODS: Seventy-two patients with significant dysphagia from benign strictures due to a variety of causes were dilated endoscopically. Patients with achalasia, malignant lesions or external compression were excluded. The procedure consisted of two parts. First, a guide wire was placed through video endoscopy and then dilatation was performed without fluoroscopy. In general, “the rule of three” was followed. Effective treatment was defined as the ability of patients, with or without repeated dilatations, to maintain a solid or semisolid diet for more than 12 mo. RESULTS: Six hundred and sixty two dilatations in a total of 72 patients were carried out. The success rate for placement of a guide wire was 100% and for dilatation 97%, without use of fluoroscopy, after 6 mo to 4 years of follow-up. The number of sessions per patient was between 1 and 7, with an average of 2 sessions. The ability of patients, after 1 or more sessions of dilatation, to maintain a solid or semisolid diet for more than 12 mo was obtained in 70 patients (95.8%). For very tight esophageal strictures, all patients improved clinically without complications after the endoscopic procedure without fluoroscopy, but we noted 3 failures. CONCLUSION: Dilatation using Savary-Gilliard dilators without fluoroscopy is safe and effective in the treatment of very tight esophageal strictures if performed with care. PMID:22180849

  20. Endoscopic Papillary Large Balloon Dilation for the Retrieval of Bile Duct Stones After Prior Billroth II Gastrectomy

    PubMed Central

    Kim, Tae-Nyeun

    2014-01-01

    Background/Aims: Endoscopic retrieval of large common bile duct (CBD) stones is often difficult in patients who have undergone Billroth II gastrectomy, as anatomic alterations may present technical barriers to successful cannulation and increase procedure-related complications. Endoscopic papillary large balloon dilation (EPLBD) can be an alternative technique for the removal of difficult stones. Accordingly, the aim of this study was to evaluate the safety and effectiveness of EPLBD for CBD stone extraction in patients with Billroth II gastrectomy. Materials and Methods: From July 2006 to November 2011, 30 patients who underwent EPLBD with limited endoscopic sphincterotomy (EPLBD + ES) or EPLBD alone for the treatment of large CBD stones (≥10 mm) after Billroth II gastrectomy were retrospectively reviewed. A large balloon dilator (12-18 mm) was used to dilate the ampullary orifice. Results: Selective cannulation was successful in 25 patients (83.3%) with a standard catheter. Of the 30 subjects, EPLBD + ES was performed in 19 and EPLBD alone in 11. The mean bile duct diameter was 17.7 ± 4.3 mm (range, 11-31 mm), and mean size of balloon dilation was 14.5 ± 2.6 mm (range, 12-18 mm). Stone removal was successfully completed in 29 patients (96.7%). Successful stone retrieval during the first session was achieved in 27 patients (90.0%). Two cases (6.7%) of mild pancreatitis responded to conservative treatment, and no perforation or mortality was encountered. Conclusions: EPLBD with or without needle knife (NK) sphincterotomy seems to be a safe and feasible modality for CBD stone retrieval in patients with prior Billroth II gastrectomy. PMID:24705151

  1. The Effects of Tetrahydro-iso-alpha Acids and Niacin on Monocyte-Edothelial Cell Interactions and Flow-mediated Vasodilation.

    PubMed

    Lamb, Joseph J; Konda, Veera R; Desai, Anuradha; Bland, Jeffrey S; Tripp, Matthew L

    2012-09-01

    Niacin favorably modifies cardiovascular risk factors but is associated with flushing and shows limited benefit in improving endothelial function. We investigated whether combining anti-inflammatory tetrahydro-iso-alpha acids (THIAA) from hops with niacin would improve endothelial function. We hypothesized that the THIAA+niacin combination would demonstrate benefits not seen with niacin alone. In an in vitro model, a THIAA+niacin mixture inhibited several TNF-α-induced cytokines in human aortic endothelial cells and in human monocytic cells and was significantly more efficacious than niacin alone. Subsequently, the effect of 125 mg THIAA and 500 mg niacin on endothelial-regulated flow-mediated vasodilation (FMD) was explored in a pilot study of 11 dyslipidemic volunteers. The 12-week treatment (2 tablets/day) resulted in a clinically relevant FMD increase compared to a trend toward an FMD decrease with placebo; the between-arm difference was statistically significant. THIAA+niacin treatment also improved total cholesterol, low-density lipoprotein cholesterol, and uric acid. No significant improvement in these parameters was observed with placebo. High-sensitivity C-reactive protein was significantly increased only in the placebo arm. Nutritional support with a THIAA+niacin combination may provide benefits for endothelial function in those with dyslipidemia. PMID:24278836

  2. Effects of supplementation with the fat-soluble vitamins E and D on fasting flow-mediated vasodilation in adults: a meta-analysis of randomized controlled trials.

    PubMed

    Joris, Peter J; Mensink, Ronald P

    2015-03-10

    The effects of fat-soluble vitamin supplementation on cardiovascular disease (CVD) risk are not clear. Therefore, we performed a meta-analysis to quantify effects of fat-soluble vitamin supplements on fasting flow-mediated vasodilation (FMD) of the brachial artery, a validated marker to assess CVD risk. Randomized placebo-controlled trials (RCTs) were identified by a systematic search till July 2014. Seven RCTs studying the effects of vitamin E supplements (range: 300 to 1800 IU per day) and nine RCTs examining the effects of vitamin D supplements, that involved, respectively, 303 and 658 adults, were included. No studies with carotenoid or vitamin K supplements were found. Vitamin E supplementation increased FMD vs. control by 2.42% (95% CI: 0.46% to 4.37%; p = 0.015). No effects of vitamin D supplementation were found (0.15%; 95% CI: -0.21% to 0.51%; p = 0.41). These effects did not depend on subject characteristics, treatment characteristics or technical aspects of the FMD measurement. However, no dose-response relationship was evident for vitamin E, statistical significance depended on one study, while the levels of supplement were far above recommended intakes. The current meta-analysis, therefore, does not provide unambiguous evidence to support the use of fat-soluble vitamin supplements to improve fasting FMD in adults.

  3. The Effects of Tetrahydro-iso-alpha Acids and Niacin on Monocyte-Edothelial Cell Interactions and Flow-mediated Vasodilation.

    PubMed

    Lamb, Joseph J; Konda, Veera R; Desai, Anuradha; Bland, Jeffrey S; Tripp, Matthew L

    2012-09-01

    Niacin favorably modifies cardiovascular risk factors but is associated with flushing and shows limited benefit in improving endothelial function. We investigated whether combining anti-inflammatory tetrahydro-iso-alpha acids (THIAA) from hops with niacin would improve endothelial function. We hypothesized that the THIAA+niacin combination would demonstrate benefits not seen with niacin alone. In an in vitro model, a THIAA+niacin mixture inhibited several TNF-α-induced cytokines in human aortic endothelial cells and in human monocytic cells and was significantly more efficacious than niacin alone. Subsequently, the effect of 125 mg THIAA and 500 mg niacin on endothelial-regulated flow-mediated vasodilation (FMD) was explored in a pilot study of 11 dyslipidemic volunteers. The 12-week treatment (2 tablets/day) resulted in a clinically relevant FMD increase compared to a trend toward an FMD decrease with placebo; the between-arm difference was statistically significant. THIAA+niacin treatment also improved total cholesterol, low-density lipoprotein cholesterol, and uric acid. No significant improvement in these parameters was observed with placebo. High-sensitivity C-reactive protein was significantly increased only in the placebo arm. Nutritional support with a THIAA+niacin combination may provide benefits for endothelial function in those with dyslipidemia.

  4. Hearing Profile in Patients with Dilated and Hypertrophic Cardiomyopathies

    PubMed Central

    El-Zarea, Gehan Abd El-Rahman; Hassan, Yasser Elsayed Mohamed; Mahmoud, Ahmed Mohamed Ahmed

    2016-01-01

    Introduction Cardiomyopathy may cause disruptions in the micro-vascular system of the stria vascularis in the cochlea, and, subsequently, may result in cochlear degeneration. Degeneration in the stria vascularis affects the physical and chemical processes in the organ of Corti, thereby causing a possible hearing impairment. The objective of this study was to assess the hearing profiles of patients with dilated and hypertrophic cardiomyopathies to determine the relationship between the degree of hearing loss and the degree and duration of the disease and to compare the dilated and hypertrophic cardiomyopathies as regards hearing profile. Methods In this case control study, we studied 21 patients (cases/study group/group 1) and 15 healthy individuals (controls/group 2). Six patients (group 1a) had hypertrophic cardiomyopathy (HCM), and 15 patients (group 1b) had dilated cardiomyopathy (DCM). The data were analyzed using the t-test, chi-squared test, Kruskal-Wallis test, and the Multiple Mann-Whitney test. Results The results of this study showed that 80% of those patients with DCM (group 1b) had bilateral sensorineural hearing loss (SNHL), and 100% of the patients with HCM (group 1a) had mild to severe bilateral sloping SNHL. Distortion Product Otoacoustic Emissions (DPOAEs) were present in 14% of the study group and in 100 % of the control group. The results of the measurements of auditory brainstem response (ABR) showed that 50% of the study group had abnormal latencies compared to the control group, and there was no correlation between the duration of the disease and the degree of hearing loss or DPOAE. Fifty percent of the patients with HCM and 35% of the patients with DCM had positive family histories of similar conditions, and 35% of those with HCM had a positive family history of sudden death. Conclusion The results of this study suggested that the link between heart disease and hearing loss and early identification of hearing loss in patients with

  5. Esophageal dilation with integrated balloon imaging: initial evaluation in a porcine model

    PubMed Central

    Siersema, Peter D.

    2013-01-01

    Background: When treating achalasia, balloon dilation is often combined with fluoroscopy to allow the lower esophageal sphincter to be visualized as it is being dilated. We sought to evaluate a new balloon dilation technology, EsoFLIP, which allows the shape of the balloon to be visualized in a nonradiographic manner by using impedance planimetry electrodes located within the dilation balloon. Methods: Two pigs weighing 35 kg were used. The EsoFLIP balloon dilator was introduced under endoscopic visualization. Successive injections of 50, 60, 70 and 85 mL into the dilation balloon permitted dilations at increasing diameters to be achieved. Following each dilation fluid was withdrawn to leave 30 mL in the balloon and an EsoFLIP image was captured to track progressive dilation of the gastroesophageal junction (GEJ). Results: The EsoFLIP catheter was safely deployed in the two pigs and no complications were noted. For pig 1, during dilation, the measured balloon diameter at the waist was 24.1, 28.9, 29.2 and 30.0 mm for balloon dilation volumes of 50, 60, 70 and 85 mL respectively. For pig 2 the corresponding diameter at the waist was 22.8, 27.1, 28.5 and 29.4 mm. The GEJ diameter increased from 12.5 and 12.4 mm to 17.4 and 17.5mm for pigs 1 and 2 respectively. Distensibility of the GEJ in pig 1 increased from 2.3 mm2/mmHg before to 4.4 mm2/mmHg after dilation and in pig 2 from 4.4 to 9.6 mm2/mmHg. The GEJ substantively achieved its final diameter after the dilation using just 50 mL in the balloon. Conclusions: We demonstrated technical feasibility and safety of the EsoFLIP dilator in a porcine model. Further studies in humans with achalasia remain to be conducted, which, besides demonstrating technical feasibility, should also evaluate the use of distensibility measurements taken during dilation to predict outcomes. PMID:23503681

  6. Prevention of age-related endothelial dysfunction by habitual aerobic exercise in healthy humans: possible role of nuclear factor κB.

    PubMed

    Walker, Ashley E; Kaplon, Rachelle E; Pierce, Gary L; Nowlan, Molly J; Seals, Douglas R

    2014-12-01

    Habitual aerobic exercise prevents age-related impairments in endothelium-dependent dilation (EDD). We have hypothesized that the pro-inflammatory transcription factor nuclear factor κB (NF-κB) impairs EDD with sedentary aging, and habitual aerobic exercise prevents this age-related suppression of EDD by NF-κB. To test this hypothesis, we have inhibited NF-κB signalling via oral salsalate administration in healthy older aerobic exercise-trained adults (OT, n=14, 58 ± 2 years), older non-exercising adults (ON, n=16, 61 ± 1 years) and young non-exercising controls (YN, n=8, 23 ± 1 years). Salsalate reduced endothelial cell expression of NF-κB p65 by ~25% in ON (P<0.05) but did not significantly change expression in OT or YN (P>0.05). EDD, assessed by brachial artery flow-mediated dilation (FMD), was improved by salsalate in ON (4.0 ± 0.7% compared with 6.8 ± 0.7%, placebo compared with salsalate, P<0.001) but did not change with salsalate in OT or YN (OT: 7.2 ± 0.7% compared with 7.7 ± 0.6%; YN: 7.6 ± 0.9% compared with 8.1 ± 0.8%; placebo compared with salsalate, P>0.05). Endothelium-independent dilation was not affected by salsalate in any group (P>0.05). In ON, vitamin C infusion improved FMD by ~30% during placebo (P<0.001) but had no affect during salsalate (P>0.05). In OT and YN, vitamin C infusion did not affect FMD during either placebo or salsalate (P>0.05). Salsalate reduced endothelial cell nitrotyrosine content by ~25% and NADPH oxidase p47phox expression by ~30% in ON (P<0.05) but had no effect in OT or YN (P>0.05). Our results suggest that endothelial NF-κB signalling is associated with oxidative stress-related impairment of EDD in healthy non-exercising but not aerobically exercising older adults. This may be a key mechanism by which regular aerobic exercise preserves endothelial function and reduces cardiovascular risk with aging.

  7. Shape waves in 2D Josephson junctions: exact solutions and time dilation.

    PubMed

    Gulevich, D R; Kusmartsev, F V; Savel'ev, Sergey; Yampol'skii, V A; Nori, Franco

    2008-09-19

    We predict a new class of excitations propagating along a Josephson vortex in two-dimensional Josephson junctions. These excitations are associated with the distortion of a Josephson vortex line and have an analogy with shear waves in solid mechanics. Their shapes can have an arbitrary profile, which is retained when propagating. We derive a universal analytical expression for the energy of arbitrary shape excitations, investigate their influence on the dynamics of a vortex line, and discuss conditions where such excitations can be created. Finally, we show that such excitations play the role of a clock for a relativistically moving Josephson vortex and suggest an experiment to measure a time dilation effect analogous to that in special relativity. PMID:18851404

  8. Some Pitfalls in Special Relativity

    ERIC Educational Resources Information Center

    Chai, An-Ti

    1973-01-01

    The problem of observing a collision between two spaceships is utilized to illustrate the misuse of time dilation and length contraction, and the incorrect description of space-time coordinates in special relativity. (Author/DF)

  9. Kidney infarction in Friedreich's ataxia with dilated cardiomyopathy.

    PubMed

    Evangelopoulos, Dimitrios Stergios; Pirvu, Tatiana Nataly; Exadaktylos, Aristomenis; Kohl, Sandro

    2012-09-30

    A 37-year-old man with advanced Friedreich's ataxia was referred to our emergency department with acute exacerbated abdominal pain of unclear aetiology. Laboratory tests showed slightly increased inflammatory parameters, elevated troponin and B-type natriuretic peptide, as well as minimal proteinuria. Transthoracic echocardiography revealed a pre-existing dilated cardiomyopathy. Abdominal sonography showed no pathological alterations. Owing to persistent pain under analgesia, a contrast-enhanced CT-abdomen was performed, which revealed a non-homogeneous perfusion deficit of the right kidney, although neither abdominal vascular alteration, cardiac thrombus, deep vein thrombosis nor a patent foramen ovale could be detected. Taking all clinical and radiological results into consideration, the current incident was diagnosed as a thromboembolic kidney infarction. As a consequence, lifelong oral anticoagulation was initiated.

  10. External nasal dilators: definition, background, and current uses

    PubMed Central

    Dinardi, Ricardo Reis; de Andrade, Cláudia Ribeiro; Ibiapina, Cássio da Cunha

    2014-01-01

    Our goal was to revise the literature about external nasal dilators (ENDs) as to their definition, history, and current uses. We reviewed journals in the PubMed and MEDLINE databases. The current uses hereby presented and discussed are physical exercise, nasal congestion and sleep, snoring, pregnancy, cancer, and healthy individuals. Numerous studies have shown that ENDs increase the cross-sectional area of the nasal valve, reducing nasal resistance and transnasal inspiratory pressure and stabilizing the lateral nasal vestibule, avoiding its collapse during final inspiration. These effects also facilitate breathing and are beneficial to patients with nasal obstruction. Furthermore, END use is simple, noninvasive, painless, affordable, and bears minimum risk to the user. Most studies have limited sample size and are mainly focused on physical exercise. In conclusion, ENDs seem useful, so further studies involving potential effects on the performance of physical tests and improvements in sleep quality are necessary, especially in children and teenagers. PMID:25419156

  11. Cardiovascular genetics: technological advancements and applicability for dilated cardiomyopathy.

    PubMed

    Kummeling, G J M; Baas, A F; Harakalova, M; van der Smagt, J J; Asselbergs, F W

    2015-07-01

    Genetics plays an important role in the pathophysiology of cardiovascular diseases, and is increasingly being integrated into clinical practice. Since 2008, both capacity and cost-efficiency of mutation screening of DNA have been increased magnificently due to the technological advancement obtained by next-generation sequencing. Hence, the discovery rate of genetic defects in cardiovascular genetics has grown rapidly and the financial threshold for gene diagnostics has been lowered, making large-scale DNA sequencing broadly accessible. In this review, the genetic variants, mutations and inheritance models are briefly introduced, after which an overview is provided of current clinical and technological applications in gene diagnostics and research for cardiovascular disease and in particular, dilated cardiomyopathy. Finally, a reflection on the future perspectives in cardiogenetics is given.

  12. Focal nodular hyperplasia with major sinusoidal dilatation: a misleading entity

    PubMed Central

    Laumonier, Hervé; Frulio, Nora; Laurent, Christophe; Balabaud, Charles; Zucman-Rossi, Jessica; Bioulac-Sage, Paulette

    2010-01-01

    Focal nodular hyperplasia (FNH) is a benign liver lesion thought to be a non-specific response to locally increased blood flow. Although the diagnosis of FNH and hepatocellular adenoma (HCA) has made great progress over the last few years using modern imaging techniques, there are still in daily practice some difficulties concerning some atypical nodules. Here, the authors report the case of a 47-year-old woman with a single liver lesion thought to be, by imaging, an inflammatory HCA with major sinusoidal congestion. This nodule was revealed to be, at the microscopical level and after specific immunostaining and molecular analysis, an FNH with sinusoidal dilatation (so-called telangiectatic focal nodular hyperplasia). PMID:22798311

  13. Relationships between left heart chamber dilatation on echocardiography and left-to-right ventricle shunting quantified by cardiac catheterization in children with ventricular septal defects.

    PubMed

    Gokalp, Selman; Guler Eroglu, Ayse; Saltik, Levent; Koca, Bulent

    2014-04-01

    Left atrium and/or left ventricle dilatation on echocardiography is considered to be an indication for closure of ventricular septal defects (VSD). No study has addressed the accuracy of using dilated left heart chambers when defining significant left-to-right shunting quantified by cardiac catheterization in isolated small or moderate VSDs. In this study, the relation between dilated left heart chambers, measured by echocardiography, and left-to-right ventricle shunting, quantified by cardiac catheterization, was evaluated in patients with isolated VSD. The medical records of all patients with isolated VSD who had undergone catheterization from 1996 to 2010 were examined retrospectively. Normative data for left heart chambers adjusted for body weight (BW) and body surface area (BSA) were used. The pulmonary-to-systemic flow ratio (Qp:Qs) was calculated by an oximetry technique. A total of 115 patients (mean age 7.3 ± 5 years) fulfilled the inclusion criteria. There was a statistically significant difference in terms of Qp:Qs between the patient groups with normal and dilated left heart chambers, when adjusted for BW and BSA (p = 0.001 and p = 0.002, respectively). But the relationships between Qp:Qs and left heart chamber sizes on echocardiography were not strong enough to be useful for making surgical decisions, as left heart chamber dilatation was not significantly associated with Qp:Qs ≥ 2 (p = 0.349 when adjusted for BW, p = 0.107 when adjusted for BSA). Left heart chamber dilatation was significantly associated with Qp:Qs ≥ 1.5 only when it was adjusted for BSA (for BW p = 0.022, for BSA p = 0.006). As a result, left heart chamber dilatation measured by echocardiography does not show significant left-to-right ventricle shunting, as quantified by catheterization. We still advocate that catheter angiography should be undertaken when left heart chambers are dilated in echocardiography in order to make decisions about closing small- to moderate-sized VSD.

  14. Individual Differences in Temporal Selective Attention as Reflected in Pupil Dilation

    PubMed Central

    Willems, Charlotte; Herdzin, Johannes; Martens, Sander

    2015-01-01

    Background Attention is restricted for the second of two targets when it is presented within 200–500 ms of the first target. This attentional blink (AB) phenomenon allows one to study the dynamics of temporal selective attention by varying the interval between the two targets (T1 and T2). Whereas the AB has long been considered as a robust and universal cognitive limitation, several studies have demonstrated that AB task performance greatly differs between individuals, with some individuals showing no AB whatsoever. Methodology/Principal Findings Here, we studied these individual differences in AB task performance in relation to differences in attentional timing. Furthermore, we investigated whether AB magnitude is predictive for the amount of attention allocated to T1. For both these purposes pupil dilation was measured, and analyzed with our recently developed deconvolution method. We found that the dynamics of temporal attention in small versus large blinkers differ in a number of ways. Individuals with a relatively small AB magnitude seem better able to preserve temporal order information. In addition, they are quicker to allocate attention to both T1 and T2 than large blinkers. Although a popular explanation of the AB is that it is caused by an unnecessary overinvestment of attention allocated to T1, a more complex picture emerged from our data, suggesting that this may depend on whether one is a small or a large blinker. Conclusion The use of pupil dilation deconvolution seems to be a powerful approach to study the temporal dynamics of attention, bringing us a step closer to understanding the elusive nature of the AB. We conclude that the timing of attention to targets may be more important than the amount of allocated attention in accounting for individual differences. PMID:26660976

  15. Serum Lipidomics Meets Cardiac Magnetic Resonance Imaging: Profiling of Subjects at Risk of Dilated Cardiomyopathy

    PubMed Central

    Sysi-Aho, Marko; Koikkalainen, Juha; Seppänen-Laakso, Tuulikki; Kaartinen, Maija; Kuusisto, Johanna; Peuhkurinen, Keijo; Kärkkäinen, Satu; Antila, Margareta; Lauerma, Kirsi; Reissell, Eeva; Jurkko, Raija; Lötjönen, Jyrki; Heliö, Tiina; Orešič, Matej

    2011-01-01

    Dilated cardiomyopathy (DCM), characterized by left ventricular dilatation and systolic dysfunction, constitutes a significant cause for heart failure, sudden cardiac death or need for heart transplantation. Lamin A/C gene (LMNA) on chromosome 1p12 is the most significant disease gene causing DCM and has been reported to cause 7–9% of DCM leading to cardiac transplantation. We have previously performed cardiac magnetic resonance imaging (MRI) to LMNA carriers to describe the early phenotype. Clinically, early recognition of subjects at risk of developing DCM would be important but is often difficult. Thus we have earlier used the MRI findings of these LMNA carriers for creating a model by which LMNA carriers could be identified from the controls at an asymptomatic stage. Some LMNA mutations may cause lipodystrophy. To characterize possible effects of LMNA mutations on lipid profile, we set out to apply global serum lipidomics using Ultra Performance Liquid Chromatography coupled to mass spectrometry in the same LMNA carriers, DCM patients without LMNA mutation and controls. All DCM patients, with or without LMNA mutation, differed from controls in regard to distinct serum lipidomic profile dominated by diminished odd-chain triglycerides and lipid ratios related to desaturation. Furthermore, we introduce a novel approach to identify associations between the molecular lipids from serum and the MR images from the LMNA carriers. The association analysis using dependency network and regression approaches also helped us to obtain novel insights into how the affected lipids might relate to cardiac shape and volume changes. Our study provides a framework for linking serum derived molecular markers not only with clinical endpoints, but also with the more subtle intermediate phenotypes, as derived from medical imaging, of potential pathophysiological relevance. PMID:21283746

  16. Serum lipidomics meets cardiac magnetic resonance imaging: profiling of subjects at risk of dilated cardiomyopathy.

    PubMed

    Sysi-Aho, Marko; Koikkalainen, Juha; Seppänen-Laakso, Tuulikki; Kaartinen, Maija; Kuusisto, Johanna; Peuhkurinen, Keijo; Kärkkäinen, Satu; Antila, Margareta; Lauerma, Kirsi; Reissell, Eeva; Jurkko, Raija; Lötjönen, Jyrki; Heliö, Tiina; Orešič, Matej

    2011-01-20

    Dilated cardiomyopathy (DCM), characterized by left ventricular dilatation and systolic dysfunction, constitutes a significant cause for heart failure, sudden cardiac death or need for heart transplantation. Lamin A/C gene (LMNA) on chromosome 1p12 is the most significant disease gene causing DCM and has been reported to cause 7-9% of DCM leading to cardiac transplantation. We have previously performed cardiac magnetic resonance imaging (MRI) to LMNA carriers to describe the early phenotype. Clinically, early recognition of subjects at risk of developing DCM would be important but is often difficult. Thus we have earlier used the MRI findings of these LMNA carriers for creating a model by which LMNA carriers could be identified from the controls at an asymptomatic stage. Some LMNA mutations may cause lipodystrophy. To characterize possible effects of LMNA mutations on lipid profile, we set out to apply global serum lipidomics using Ultra Performance Liquid Chromatography coupled to mass spectrometry in the same LMNA carriers, DCM patients without LMNA mutation and controls. All DCM patients, with or without LMNA mutation, differed from controls in regard to distinct serum lipidomic profile dominated by diminished odd-chain triglycerides and lipid ratios related to desaturation. Furthermore, we introduce a novel approach to identify associations between the molecular lipids from serum and the MR images from the LMNA carriers. The association analysis using dependency network and regression approaches also helped us to obtain novel insights into how the affected lipids might relate to cardiac shape and volume changes. Our study provides a framework for linking serum derived molecular markers not only with clinical endpoints, but also with the more subtle intermediate phenotypes, as derived from medical imaging, of potential pathophysiological relevance.

  17. Serum lipidomics meets cardiac magnetic resonance imaging: profiling of subjects at risk of dilated cardiomyopathy.

    PubMed

    Sysi-Aho, Marko; Koikkalainen, Juha; Seppänen-Laakso, Tuulikki; Kaartinen, Maija; Kuusisto, Johanna; Peuhkurinen, Keijo; Kärkkäinen, Satu; Antila, Margareta; Lauerma, Kirsi; Reissell, Eeva; Jurkko, Raija; Lötjönen, Jyrki; Heliö, Tiina; Orešič, Matej

    2011-01-01

    Dilated cardiomyopathy (DCM), characterized by left ventricular dilatation and systolic dysfunction, constitutes a significant cause for heart failure, sudden cardiac death or need for heart transplantation. Lamin A/C gene (LMNA) on chromosome 1p12 is the most significant disease gene causing DCM and has been reported to cause 7-9% of DCM leading to cardiac transplantation. We have previously performed cardiac magnetic resonance imaging (MRI) to LMNA carriers to describe the early phenotype. Clinically, early recognition of subjects at risk of developing DCM would be important but is often difficult. Thus we have earlier used the MRI findings of these LMNA carriers for creating a model by which LMNA carriers could be identified from the controls at an asymptomatic stage. Some LMNA mutations may cause lipodystrophy. To characterize possible effects of LMNA mutations on lipid profile, we set out to apply global serum lipidomics using Ultra Performance Liquid Chromatography coupled to mass spectrometry in the same LMNA carriers, DCM patients without LMNA mutation and controls. All DCM patients, with or without LMNA mutation, differed from controls in regard to distinct serum lipidomic profile dominated by diminished odd-chain triglycerides and lipid ratios related to desaturation. Furthermore, we introduce a novel approach to identify associations between the molecular lipids from serum and the MR images from the LMNA carriers. The association analysis using dependency network and regression approaches also helped us to obtain novel insights into how the affected lipids might relate to cardiac shape and volume changes. Our study provides a framework for linking serum derived molecular markers not only with clinical endpoints, but also with the more subtle intermediate phenotypes, as derived from medical imaging, of potential pathophysiological relevance. PMID:21283746

  18. Experimental studies of compaction and dilatancy during frictional sliding on faults containing gouge

    USGS Publications Warehouse

    Morrow, C.A.; Byerlee, J.D.

    1989-01-01

    Transient strength changes are observed in fault gouge materials when the velocity of shearing is varied. A transient stress peak is produced when the strain rate in the gouge is suddenly increased, whereas a transient stress drop results from a sudden change to a slower strain rate. We have studied the mechanism responsible for these observations by performing frictional sliding experiments on sawcut granite samples filled with a layer of several different fault gouge types. Changes in pore volume and strength were monitored as the sliding velocity alternated between fast and slow rates. Pore volume increased at the faster strain rate, indicating a dilation of the gouge layer, whereas volume decreased at the slower rate indicating compaction. These results verify that gouge dilation is a function of strain rate. Pore volume changed until an equilibrium void ratio of the granular material was reached for a particular rate of strain. Using arguments from soil mechanics, we find that the dense gouge was initially overconsolidated relative to the equilibrium level, whereas the loose gouge was initially underconsolidated relative to this level. Therefore, the transient stress behavior must be due to the overconsolidated state of the gouge at the new rate when the velocity is increased and to the underconsolidated state when the velocity is lowered. Time-dependent compaction was also shown to cause a transient stress response similar to the velocity-dependent behavior. This may be important in natural fault gouges as they become consolidated and stronger with time. In addition, the strain hardening of the gouge during shearing was found to be a function of velocity, rendering it difficult to quantify the change in equilibrium shear stress when velocity is varied under certain conditions. ?? 1989.

  19. Septo-Optic Dysplasia in a Newborn Presenting with Bilateral Dilated and Fixed Pupils

    PubMed Central

    Jabeen, Mehnaz; Hairfield, Amber; Swischuk, Leonard E.; Jain, Sunil K.

    2016-01-01

    Introduction We describe a newborn female infant with septo-optic dysplasia (SOD) presenting with bilateral dilated and fixed pupils. Conclusion Our report is unique because the incidental finding of bilateral dilated and fixed pupils on the newborn exam was the only clinical finding which led to a prompt work-up and eventual diagnosis of SOD. PMID:26929862

  20. Measurements of two types of dilatational waves in an air-filled unconsolidated sand

    SciTech Connect

    Hickey, C.J.; Sabatier, J.M.

    1997-07-01

    This study consists of laboratory measurements of dilatational waves propagating through an air-filled unconsolidated sand. One excitation technique consists of a loudspeaker suspended in the air above the packing of sand. A second excitation technique uses a mechanical shaker in contact with the sand. The transmitted signals are received using microphones and geophones located at various depths within the sand. An interpretation based on measured phase speeds indicates that the transmitted energy from the suspended loudspeaker source is partitioned primarily but not exclusively into the type-II dilatational wave. This wave attenuates rapidly and is only detected at depths of less than about 15 cm for this particular sample. At the deeper depths the detected signal is associated with the type-I dilatational wave. The mechanical shaker produces only a type-I dilatational wave. Both the geophone and microphone sensors can detect both types of dilatational waves. {copyright} {ital 1997 Acoustical Society of America.}

  1. [The scintigraphic assessment of the patients suffering from cardia achalasia, treated by pneumatic dilatation].

    PubMed

    Stan, Mărioara; Bălan, G; Rusu, Maria; Ciortescu, Irina; Popa, Florentina

    2002-01-01

    The esophageal scintigraphy is a technique used to evaluate the motility and the clearance of the esophagus. The patients with achalasia of the cardia were evaluated, before treating them with pneumatic dilatation and after. The reason is to evaluate the efficiency of the pneumatic dilatation technique in the treatment of esophageal achalasia. The pneumatic dilatation with an instrument type Rigiflex is a well/handled and used technique in our clinic. In the study 22 patients were included and we had in view the esophageal transit time and the residuary radioactivity before and after the pneumatic dilatation. We established an important statistical improvement of the data obtained after the dilatation comparative with the data before the treatment (p < 0.01). PMID:12638275

  2. [The usefulness of intravascular echography during the percutaneous dilatation of aortic coarctation].

    PubMed

    Goicolea, F J; Macaya, C; Iñíguez, A; Alfonso, F; Hernández Antolín, R; Vila i Costa, I; Zamorano, J; Egocheaga, I; Zarco, P

    1992-01-01

    An intravascular ultrasound study was performed in a patient, to assess the anatomy of aortic coarctation and the results obtained after percutaneous dilation with a balloon catheter. Intravascular ultrasound imaging provides important additional information, not obtainable with other diagnostic procedures, regarding aortic wall structure and thickness. After balloon dilation, aortic disruption was clearly observed, accounting, together with the stretching of the outer layers of the aortic wall, for the increase in aortic luminal area. Intravascular ultrasound permitted also the accurate assessment of the improvement obtained. Intravascular imaging was clearly superior not only to conventional angiography, but also to transesophageal echocardiography in detecting the mechanism of dilation. We conclude that ultravascular ultrasound, with the additional information that it provides, may help in the selection of patients for percutaneous dilation of the coarctation as well as contributing to the identification of the mechanism of dilation.

  3. Early development of the neorectum by balloon dilations after ileoanal anastomosis.

    PubMed

    Telander, R L; Perrault, J; Hoffman, A D

    1981-12-01

    Recently, young people with chronic ulcerative colitis and familial polyposis have been undergoing colectomy with rectal mucosectomy and ileoanal anastomosis with encouraging clinical results. However, during the early period after closing the temporary ileostomy, some patients have frequent stools, which decrease with time as the terminal ileum dilates and becomes a reservoir. To enhance the early development of the neorectal reservoir and to minimize the frequent stooling, we instituted balloon dilations of the neorectum before ileostomy closure. A group of 16 patients not undergoing balloon dilations were compared with a similar group of 13 patients who had balloon dilations. Patients undergoing balloon dilations were observed to have an increase of 40.6% per month in the measured volume of the neorectum, along with a decrease of approximately 40% in the mean number of stools at 3 mo and 34% at 6 mo, with a very acceptable clinical result.

  4. Flickering task–irrelevant distractors induce dilation of target duration depending upon cortical distance

    PubMed Central

    Okajima, Miku; Yotsumoto, Yuko

    2016-01-01

    Flickering stimuli are perceived to be longer than stable stimuli. This so-called “flicker-induced time dilation” has been investigated in a number of studies, but the factors critical for this effect remain unclear. We explored the spatial distribution of the flicker effect and examined how the flickering task-irrelevant distractors spatially distant from the target induce time dilation. In two experiments, we demonstrated that flickering distractors dilated the perceived duration of the target stimulus even though the target stimulus itself was stable. In addition, when the distractor duration was much longer than the target duration, a flickering distractor located ipsilateral to the target caused greater time dilation than did a contralateral distractor. Thus the amount of dilation depended on the distance between the cortical areas responsible for the stimulus locations. These findings are consistent with the recent study reporting that modulation of neural oscillators encoding the interval duration could explain flicker-induced time dilation. PMID:27577614

  5. Small Intestinal Submucosa Plug for Closure of Dilated Nephrostomy Tracts: A Pilot Study in Swine

    SciTech Connect

    Kakizawa, Hideyaki; Conlin, M. J.; Pavcnik, Dusan Uchida, Barry T.; Loriaux, Marc; Kim, Young Hwan; Keller, Frederick S.; Roesch, Josef

    2010-06-15

    The aim of this study was to evaluate efficacy of a plug made of small intestinal submucosa (SIS) for closure of dilated nephrostomy tract in the kidney after nephroscopy. Ten kidneys in 5 swine had nephrostomy tracts dilated up to 8 mm. The SIS plug was placed into the dilated renal cortex under nephroscopic control. Follow-up arteriograms, retrograde pyelograms, and macroscopic and histologic studies at 24 h (n = 4), 6 weeks (n = 2), and 3 months (n = 4) were performed to evaluate the efficacy of the plug. The SIS plug effectively closed the dilated nephrostomy tract. Follow-up studies showed minimal changes of the kidneys, except for 1 small infarction, regarding inflammatory and foreign-body reactions and progressive scarring of the SIS. SIS plug is effective for occlusion of dilated nephrostomy tract after nephroscopy. Its efficacy should be compared with other therapeutic options.

  6. The Eyes Have It: Sex and Sexual Orientation Differences in Pupil Dilation Patterns

    PubMed Central

    Rieger, Gerulf; Savin-Williams, Ritch C.

    2012-01-01

    Recent research suggests profound sex and sexual orientation differences in sexual response. These results, however, are based on measures of genital arousal, which have potential limitations such as volunteer bias and differential measures for the sexes. The present study introduces a measure less affected by these limitations. We assessed the pupil dilation of 325 men and women of various sexual orientations to male and female erotic stimuli. Results supported hypotheses. In general, self-reported sexual orientation corresponded with pupil dilation to men and women. Among men, substantial dilation to both sexes was most common in bisexual-identified men. In contrast, among women, substantial dilation to both sexes was most common in heterosexual-identified women. Possible reasons for these differences are discussed. Because the measure of pupil dilation is less invasive than previous measures of sexual response, it allows for studying diverse age and cultural populations, usually not included in sexuality research. PMID:22870196

  7. Flow-Mediated Endothelial Mechanotransduction

    PubMed Central

    Davies, Peter F.

    2011-01-01

    Mechanical forces associated with blood flow play important roles in the acute control of vascular tone, the regulation of arterial structure and remodeling, and the localization of atherosclerotic lesions. Major regulation of the blood vessel responses occurs by the action of hemodynamic shear stresses on the endothelium. The transmission of hemodynamic forces throughout the endothelium and the mechanotransduction mechanisms that lead to biophysical, biochemical, and gene regulatory responses of endothelial cells to hemodynamic shear stresses are reviewed. PMID:7624393

  8. Metabolic syndrome is associated with left ventricular dilatation in primary hypertension.

    PubMed

    Ratto, E; Viazzi, F; Verzola, D; Bonino, B; Gonnella, A; Parodi, E L; Bezante, G P; Leoncini, G; Pontremoli, R

    2016-03-01

    Metabolic syndrome (MS) has been shown to predict cardiovascular events in hypertension. Recently, a new four-group left ventricular (LV) hypertrophy classification based on both LV dilatation and concentricity was proposed. This classification has been shown to provide a more accurate prediction of cardiovascular events, suggesting that the presence of LV dilatation may add prognostic information. We investigated the relationship between MS and the new classification of LV geometry in patients with primary hypertension. A total of 372 untreated hypertensive patients were studied. Four different patterns of LV hypertrophy (eccentric nondilated, eccentric dilated, concentric nondilated and concentric dilated hypertrophy) were identified by echocardiography. A modified National Cholesterol Education Program definition for MS was used, with body mass index replacing waist circumference. The overall prevalence of MS and LV hypertrophy (LVH) was 29% and 61%, respectively. Patients with MS showed a higher prevalence of LVH (P=0.0281) and dilated LV geometries, namely eccentric dilated and concentric dilated hypertrophy (P=0.0075). Moreover, patients with MS showed higher LV end-diastolic volume (P=0.0005) and prevalence of increased LV end-diastolic volume (P=0.0068). The prevalence of LV chamber dilatation increased progressively with the number of components of MS (P=0.0191). Logistic regression analysis showed that the presence of MS entails a three times higher risk of having LV chamber dilatation even after adjusting for several potential confounding factors. MS is associated with LV dilatation in hypertension. These findings may, in part, explain the unfavourable prognosis observed in patients with MS.

  9. Dipyridamole dilates large cerebral arteries concomitant to headache induction in healthy subjects.

    PubMed

    Kruuse, C; Jacobsen, T B; Lassen, L H; Thomsen, L L; Hasselbalch, S G; Dige-Petersen, H; Olesen, J

    2000-09-01

    Dipyridamole is used for secondary prophylaxis in ischemic stroke and as a vasodilator agent in myocardial scintigraphy. An important side effect to administering dipyridamole is headache. The aim of the current study was to investigate the effects of dipyridamole on cerebral blood flow, large artery diameter, and headache induction. Twelve healthy subjects were included in this single-blind placebo-controlled study in which placebo (0.9% NaCl) and dipyridamole 0.142 mg/kg x min were administered intravenously over 4 minutes 1 hour apart. Blood flow velocity in the middle cerebral artery (Vmax) was recorded by transcranial Doppler and regional cerebral blood flow in the middle cerebral artery (rCBFmca) was measured using single photon emission computed tomography and 133Xenon-inhalation. Blood pressure, heart rate, and pCO2 were measured repeatedly. Headache response was scored every 10 minutes on a verbal scale from 0 to 10 (10 = worst). Dipyridamole caused a decrease in pCO2 (P < 0.001). pCO2 corrected rCBFmca was 41.7 +/- 6.9 mL/100 g x min after placebo versus 41.2 +/- 6.9 after dipyridamole (P > or = 0.05). pCO2 corrected Vmca decreased 8.4% +/- 11.7 (P < 0.001) after dipyridamole, indicating a mean 5.6% +/- 6.7 (P = 0.005) relative increase of the arterial diameter. After dipyridamole the median peak headache score was 2 (range 0 to 7) compared with 0 (range 0 to 3) after placebo (P = 0.02). Dilatation of the middle cerebral artery outlasted the headache response. In conclusion, dipyridamole causes a modest pCO2 independent dilatation of the MCA, which is time-linked to the onset, but not to the cessation, of headache.

  10. Biodegradable stent or balloon dilatation for benign oesophageal stricture: Pilot randomised controlled trial

    PubMed Central

    Dhar, Anjan; Close, Helen; Viswanath, Yirupaiahgari K; Rees, Colin J; Hancock, Helen C; Dwarakanath, A Deepak; Maier, Rebecca H; Wilson, Douglas; Mason, James M

    2014-01-01

    AIM: To undertake a randomised pilot study comparing biodegradable stents and endoscopic dilatation in patients with strictures. METHODS: This British multi-site study recruited seventeen symptomatic adult patients with refractory strictures. Patients were randomised using a multicentre, blinded assessor design, comparing a biodegradable stent (BS) with endoscopic dilatation (ED). The primary endpoint was the average dysphagia score during the first 6 mo. Secondary endpoints included repeat endoscopic procedures, quality of life, and adverse events. Secondary analysis included follow-up to 12 mo. Sensitivity analyses explored alternative estimation methods for dysphagia and multiple imputation of missing values. Nonparametric tests were used. RESULTS: Although both groups improved, the average dysphagia scores for patients receiving stents were higher after 6 mo: BS-ED 1.17 (95%CI: 0.63-1.78) P = 0.029. The finding was robust under different estimation methods. Use of additional endoscopic procedures and quality of life (QALY) estimates were similar for BS and ED patients at 6 and 12 mo. Concomitant use of gastrointestinal prescribed medication was greater in the stent group (BS 5.1, ED 2.0 prescriptions; P < 0.001), as were related adverse events (BS 1.4, ED 0.0 events; P = 0.024). Groups were comparable at baseline and findings were statistically significant but numbers were small due to under-recruitment. The oesophageal tract has somatic sensitivity and the process of the stent dissolving, possibly unevenly, might promote discomfort or reflux. CONCLUSION: Stenting was associated with greater dysphagia, co-medication and adverse events. Rigorously conducted and adequately powered trials are needed before widespread adoption of this technology. PMID:25561787

  11. Consequences of frictional melting and catastrophic dilation along caldera superfaults: Glencoe, Scotland

    NASA Astrophysics Data System (ADS)

    Clesham, Stephen; Kokelaar, Peter; Lavallee, Yan; Faulkner, Dan

    2014-05-01

    The Glencoe Caldera records complex piecemeal caldera collapse along superfaults with slip rates in sufficient to induce frictional melting. The deeply dissected volcano exposes outer fault segments with cm-scale bands of pseudotachylyte in contact with breccias, cataclasites and magmatic fault intrusions along the fault plane. Processes of frictional melting, cataclasis and intrusion were closely associated and the various materials show evidence for fluid-state mixing. At shallow depths, where the caldera faults dip outwards, rapid subsidence of the caldera footwall led to catastrophic dilation and the formation of free surfaces at low pressures. Decompressed hydrothermal systems were explosively excavated to form irregular voids behind the original fault surfaces. In such dilatant sections of the fault, frictional melts and then magma intrusions were fragmented and explosively transformed to froths or sprays that coated newly-formed void walls. We suggest that these processes are likely to have formed the lithic breccias with hydrothermally altered and thermally spalled clasts - common in caldera-related ignimbrites. Mineralogy and clast-size distribution analysis indicate that some pseudotachylytes formed virtually in-situ, from the (Dalradian) metamorphic basement psammites and quartzites, while others were apparently sourced at considerable depths. Lithic clasts and xenoliths within the fault intrusions and pseudotachylytes imply a granitic source, probably the Rannoch Moor pluton, which in turn suggests transport of frictional melt for at least several hundreds of metres up the caldera fault, conceivably as fluidized froth. Modelling and reproduction of pseudotachylyte using laboratory friction experiments are intended to investigate the conditions that generated these rocks, and to explore their mobility as melts and fragmented products, shedding light on the processes of friction in volcanic environments.

  12. TURBULENCE IN THE INTERGALACTIC MEDIUM: SOLENOIDAL AND DILATATIONAL MOTIONS AND THE IMPACT OF NUMERICAL VISCOSITY

    SciTech Connect

    Zhu, Weishan; Gu, Qiusheng; Feng, Long-long; Xia, Yinhua; Shu, Chi-Wang; Fang, Li-Zhi

    2013-11-01

    We use a suite of cosmological hydrodynamical simulations, run by two fixed grid codes, to investigate the properties of solenoidal and dilatational motions of the intergalactic medium (IGM) and the impact of numerical viscosity on turbulence in an ΛCDM universe. The codes differ only in the spatial difference discretization. We find that (1) The vortical motion grows rapidly since z = 2 and reaches ∼10 km s{sup –1}-90 km s{sup –1} at z = 0. Meanwhile, the small-scale compressive ratio r{sub CS} drops from 0.84 to 0.47, indicating comparable vortical and compressive motions at z = 0. (2) Power spectra of the solenoidal velocity possess two regimes, ∝k {sup –0.89} and ∝k {sup –2.02}, while the total and dilatational velocity follow the scaling k {sup –1.88} and k {sup –2.20}, respectively, in the turbulent range. The IGM turbulence may contain two distinct phases, the supersonic and post-supersonic phases. (3) The non-thermal pressure support, measured by the vortical kinetic energy, is comparable with the thermal pressure for ρ{sub b} ≅ 10-100, or T < 10{sup 5.5} K at z = 0.0. The deviation of the baryon fraction from the cosmic mean shows a preliminary positive correlation with the turbulence pressure support. (4) A relatively higher numerical viscosity would dissipate both the compressive and vortical motions of the IGM into thermal energy more effectively, resulting in less developed vorticity, remarkably shortened inertial range, and leading to a non-negligible uncertainty in the thermal history of gas accretion. Shocks in regions outside of clusters are significantly suppressed by numerical viscosity since z = 2, which may directly cause the different levels of turbulence between the two codes.

  13. Granular Dilatancy and its Effect on Debris-flow Dynamics

    NASA Astrophysics Data System (ADS)

    Iverson, R. M.; George, D. L.

    2012-12-01

    Landslides and debris flows commonly exhibit the effects of variable granular dilatancy, but incorporation of these effects in predictive models of debris-flow dynamics has been lacking. We have developed a depth-averaged model of debris-flow initiation and motion that includes the effects of variable dilatancy without stipulating its influence on rheology. Instead, the apparent rheology of Coulomb-frictional debris evolves during coupled evolution of the grain concentration m, basal pore-fluid pressure, flow thickness, and flow velocity. The dilatancy angle ψ plays an intermediary role in this evolution and obeys the simple relationship tan ψ = m-meq, where meq is the grain concentration in equilibrium with the ambient stress state and flow rate. Results of recent stress-controlled rheometric experiments by Boyer et al. (DOI: 10.1103/PhysRevLett.107.188301) provide our basis for estimating meq. Relaxation of m toward meq, coupled with evolution of pore pressure, allows our model to simulate a smooth transition from static limiting equilibrium of slopes to disequilibrium flow dynamics. Use of variable friction coefficients or dam-break initial conditions is unnecessary. We have evaluated predictions of our model in three ways: (1) by examining physical implications of exact solutions of simplified model equations, (2) by comparing numerical solutions with results of controlled experiments at the USGS debris-flow flume, and (3) by comparing numerical predictions with the behavior of a large (~50 million m3) debris flow that occurred at Mt. Meager, British Columbia, in 2010. Model predictions depend mostly on initial conditions, flow-path topography, and the value of a single dimensionless parameter that represents the ratio of two key timescales. One timescale governs downslope, gravity-driven motion of debris, and the other governs pore-pressure diffusion. Values of these timescales are readily calculated from source-area geometry and standard geotechnical

  14. Deformation of rock: A pressure-sensitive, dilatant material

    NASA Astrophysics Data System (ADS)

    Ord, A.

    1991-12-01

    Permanent (plastic) deformation of rock materials in the brittle regime (cataclastic flow) is modelled here in terms of Mohr-Coulomb behaviour in which all three of the parameters cohesion, friction angle and dilation angle follow hardening (or softening) evolution laws with both plastic straining and increases in confining pressure. The physical basis for such behaviour is provided by a sequence of uniaxial shortening experiments performed by Edmond and Paterson (1972) at confining pressures up to 800 MPa on a variety of materials including Gosford sandstone and Carrara marble. These triaxial compression experiments are important for the large range of confining pressures covered, and for the careful recording of data during deformation, particularly volume change of the specimens. Both materials are pressure-sensitive and dilatant. It is therefore possible to derive from these experiments a set of material parameters which allow a preliminary description of the deformation behaviour in terms of a non-associated, Mohr-Coulomb constitutive model, thus providing the first constitutive modelling of geological materials in the brittle-ductile regime. These parameters are used as input to a finite difference, numerical code (FLAC) with the aim of investigating how closely this numerical model simulates real material behaviour upon breakdown of homogeneous deformation. The mechanical and macrostructural behaviour exhibited by the numerical model is in close agreement with the physical results in that the stress-strain curves are duplicated together with localization behaviour. The results of the modelling illustrate how the strength of the upper-crust may be described by two different but still pressure-dependent models: the linear shear stress/normal stress relationship of Amontons (that is, Byerlee's Law), and a non-linear, Mohr-Coulomb constitutive model. Both include parameters of friction and both describe brittle deformation behaviour. Consideration of the non

  15. Optical clocks and relativity.

    PubMed

    Chou, C W; Hume, D B; Rosenband, T; Wineland, D J

    2010-09-24

    Observers in relative motion or at different gravitational potentials measure disparate clock rates. These predictions of relativity have previously been observed with atomic clocks at high velocities and with large changes in elevation. We observed time dilation from relative speeds of less than 10 meters per second by comparing two optical atomic clocks connected by a 75-meter length of optical fiber. We can now also detect time dilation due to a change in height near Earth's surface of less than 1 meter. This technique may be extended to the field of geodesy, with applications in geophysics and hydrology as well as in space-based tests of fundamental physics.

  16. [Intraluminal dilation of inferior vena cava stenosis after repair of the scimitar syndrome in an adult patient].

    PubMed

    Benito Bartolomé, Fernando; González García, Ana; Oliver Ruiz, José M

    2002-02-01

    A 39 year-old woman diagnosed with anomalous drainage of middle and lower right pulmonary veins to the inferior vena cava was corrected surgically by means of baffle with patch up to the left atrium. Early after the operation the patient related intolerance to small efforts and an episode of syncope. The cardiac catheterization demonstrated the presence of a severe stenosis in the inferior vena cava, in its union with the right atrium, that was successfully treated by means of intraluminal percutaneous dilation with a catheter of Inoue. After the procedure the gradient decreased and she improved tolerance to effort, which persisted 10 months later.

  17. Cervical dilation before first-trimester surgical abortion (<14 weeks' gestation).

    PubMed

    Allen, Rebecca H; Goldberg, Alisa B

    2016-04-01

    First-trimester surgical abortion is a common, safe procedure with a major complication rate of less than 1%. Cervical dilation before suction abortion is usually accomplished using tapered mechanical dilators. Risk factors for major complications in the first trimester include increasing gestational age and provider inexperience. Cervical priming before first-trimester surgical abortion has been studied using osmotic dilators and pharmacologic agents, most commonly misoprostol. Extensive data demonstrate that a variety of agents are safe and effective at causing preoperative cervical softening and dilation; however, given the small absolute risk of complications, the benefit of routine use of misoprostol or osmotic dilators in first-trimester surgical abortion is unclear. Although cervical priming results in reduced abortion time and improved provider ease, it requires a delay of at least 1 to 3 h and may confer side effects. The Society of Family Planning does not recommend routine cervical priming for first-trimester suction abortion but recommends limiting consideration of cervical priming for women at increased risk of complications from cervical dilation, including those late in the first trimester, adolescents and women in whom cervical dilation is expected to be challenging. PMID:26683499

  18. Malignant Esophagogastric Junction Obstruction: Efficacy of Balloon Dilation Combined with Chemotherapy and/or Radiation Therapy

    SciTech Connect

    Ko, Gi-Young; Song, Ho-Young Hong, Heuk-Jin; Sung, Kyu-Bo; Seo, Tae-Seok; Yoon, Hyun-Ki

    2003-04-15

    Purpose: To assess the efficacy of balloon dilation combined with chemotherapy and/or radiation therapy for palliation of dysphagia due to malignant esophagogastric junction strictures. Methods: Fluoroscopically guided balloon dilation was attempted in 20 patients. The causes of strictures were gastric adenocarcinoma (n = 10) and esophageal squamous cell carcinoma (n = 10). Scheduled chemotherapy and/or radiation therapy followed balloon dilation in all patients. Results: There were no technical failures or major complications. After balloon dilation, 15 (75%) patients showed improvement of dysphagia. No patient complained of reflux esophagitis during the follow-up period. Among the 15 patients, seven needed no further treatment for palliation of dysphagia until their deaths. The remaining eight patients underwent repeat balloon dilation(n = 4) or stent placement (n = 4)3-43 weeks (mean 15 weeks) after the initial balloon dilation because of recurrent dysphagia. Conclusion: Balloon dilation combined with chemotherapy and/or radiation therapy seems to be an easy and reasonably effective palliative treatment for malignant esophagogastric strictures.

  19. Balloon Dilatation of Pediatric Subglottic Laryngeal Stenosis during the Artificial Apneic Pause: Experience in 5 Children

    PubMed Central

    Lisý, J.; Groh, D.; Chovanec, M.; Marková, M.; Suchánek, V.; Polášková, P.; Trávníček, M.

    2014-01-01

    Introduction. Balloon dilatation is a method of choice for treatment of laryngeal stenosis in children. The aim of procedure in apneic pause is to avoid new insertion of tracheostomy cannula. Patients and Methods. The authors performed balloon dilatation of subglottic laryngeal strictures (SGS) in 5 children (3 girls and 2 boys) without tracheotomy. Two of them with traumatic and inflammatory SGS had a tracheal cannula removed in the past. The other 3 children with postintubation SGS had never had a tracheostomy before. The need for tracheostomy due to worsening stridor was imminent for all of them. Results. The total of seven laryngeal dilatations by balloon esophagoplasty catheter in apneic pause was performed in the 5 children. The procedure averted the need for tracheostomy placement in 4 of them (80%). Failure of dilatation in girl with traumatic stenosis and concomitant severe obstructive lung disease led to repeated tracheostomy. Conclusion. Balloon dilatation of laryngeal stricture could be done in the absence of tracheostomy in apneic pause. Dilatation averted threatening tracheostomy in all except one case. Early complication after the procedure seems to be a negative prognostic factor for the outcome of balloon dilatation. PMID:25013778

  20. Long-term outcomes of balloon dilation for acquired subglottic stenosis in children.

    PubMed

    Filiz, Aliye; Ulualp, Seckin O

    2014-01-01

    Objectives. Balloon dilation laryngoplasty has been suggested as an alternative treatment to open surgical treatment of acquired subglottic stenosis in children. We describe long-term outcomes of balloon dilation for acquired subglottic stenosis in children. Methods. The medical charts of children who had balloon dilation for subglottic stenosis secondary to intubation were reviewed. Data included demographics, relevant history and physical examination, diagnostic workup, and management. Outcomes of balloon dilation were assessed based on improvement in preoperative symptoms, grading of stenosis, complications, and need for additional procedures. Results. Three children (2 male, 1 female, age range: 14 weeks-1 year) underwent balloon dilation for acquired subglottic stenosis. Patients presented with stridor and increased work of breathing. Duration of intubation ranged from 2 days to 3 weeks. Patients became symptomatic 5 days to 6 weeks after extubation. Grade of subglottic stenosis was II in 2 patients and III in one. Subglottic stenosis patients had 2-3 dilations within 2-10 weeks. All patients were asymptomatic during 14-21-month follow-up. Conclusions. Serial balloon dilation was safe and successful method to manage acquired subglottic stenosis in this group of children. No recurrence was noted in a follow-up more than a year after resolution of symptoms.

  1. Insoluble layer deposition and dilatational rheology at a microscale spherical cap interface.

    PubMed

    Kotula, Anthony P; Anna, Shelley L

    2016-08-17

    The dilatational properties of insoluble monolayers are important for understanding the mechanics of biological systems and consumer products, but isolating the dilatational response of an interface is challenging due to the difficulties in separating dilatation from shear and other deformation modes. Oscillations of a microscale bubble radius are useful for generating purely dilatational flows, but the current deposition methods for insoluble layers onto fluid interfaces are not easily scaled down. In this paper, we describe a miscible solvent exchange procedure for generating insoluble layers at an air-water interface pinned at the tip of a capillary tens of micrometers in diameter. We show that the amount of surfactant adsorbed at the interface can be controlled by the initial concentration dissolved in isopropanol (the starting solvent) and the volumetric flow rate of solvent exchange. Surface pressure-area isotherms and dilatational moduli are measured concurrently for three insoluble surfactants: palmitic acid (PA), dimyristoylphosphatidylcholine (DMPC) and dipalmitoylphosphatidylcholine (DPPC). The isotherms measured on the microscale interface compare well with previous experiments performed on a Langmuir trough. However, the magnitudes of the dilatational moduli differ from those measured on either Langmuir trough or pendant drop apparatuses. Several possible reasons for the observed differences are discussed. A comparison of the dilatational modulus with the Gibbs elasticity is used to determine the presence of dilatational extra stresses at the interface. The isotherm and dilatational modulus of the insoluble component of the industrial surfactant Tween 80 are measured using this approach. The methods developed here also open the possibility for future study of the important role of finite size effects on microstructure formation and the resulting interfacial mechanics.

  2. Local renin-angiotensin system mediates endothelial dilator dysfunction in aging arteries.

    PubMed

    Flavahan, Sheila; Chang, Fumin; Flavahan, Nicholas A

    2016-09-01

    Aging impairs endothelium-dependent NO-mediated dilatation, which results from increased production of reactive oxygen species (ROS). The local generation of angiotensin II (ANG II) is increased in aging arteries and contributes to inflammatory and fibrotic activity of smooth muscle cells and arterial wall remodeling. Although prolonged in vivo ANG II inhibition improves the impaired endothelial dilatation of aging arteries, it is unclear whether this reflects inhibition of intravascular or systemic ANG II systems. Experiments were therefore performed on isolated tail arteries from young (3-4 mo) and old (22-24 mo) F344 rats to determine if a local renin-angiotensin system contributes to the endothelial dilator dysfunction of aging. Aging impaired dilatation to the endothelial agonist acetylcholine but did not influence responses to a nitric oxide (NO) donor (DEA NONOate). Dilatation to acetylcholine was greatly reduced by NO synthase inhibition [nitro-l-arginine methyl ester (l-NAME)] in young and old arteries. In isolated arteries, acute inhibition of angiotensin-converting enzyme (ACE) (perindoprilat), renin (aliskiren), or AT1 receptors (valsartan, losartan) did not influence dilatation to acetylcholine in young arteries but increased responses in old arteries. After ANG II inhibition, the dilator response to acetylcholine was similar in young and old arteries. ROS activity, which was increased in endothelium of aging arteries, was also reduced by inhibiting ANG II (perindoprilat, losartan). Renin expression was increased by 5.6 fold and immunofluorescent levels of ANG II were confirmed to be increased in aging compared with young arteries. Exogenous ANG II inhibited acetylcholine-induced dilatation. Therefore, aging-induced impairment of endothelium-dependent dilatation in aging is caused by a local intravascular renin-angiotensin system.

  3. Insoluble layer deposition and dilatational rheology at a microscale spherical cap interface.

    PubMed

    Kotula, Anthony P; Anna, Shelley L

    2016-08-17

    The dilatational properties of insoluble monolayers are important for understanding the mechanics of biological systems and consumer products, but isolating the dilatational response of an interface is challenging due to the difficulties in separating dilatation from shear and other deformation modes. Oscillations of a microscale bubble radius are useful for generating purely dilatational flows, but the current deposition methods for insoluble layers onto fluid interfaces are not easily scaled down. In this paper, we describe a miscible solvent exchange procedure for generating insoluble layers at an air-water interface pinned at the tip of a capillary tens of micrometers in diameter. We show that the amount of surfactant adsorbed at the interface can be controlled by the initial concentration dissolved in isopropanol (the starting solvent) and the volumetric flow rate of solvent exchange. Surface pressure-area isotherms and dilatational moduli are measured concurrently for three insoluble surfactants: palmitic acid (PA), dimyristoylphosphatidylcholine (DMPC) and dipalmitoylphosphatidylcholine (DPPC). The isotherms measured on the microscale interface compare well with previous experiments performed on a Langmuir trough. However, the magnitudes of the dilatational moduli differ from those measured on either Langmuir trough or pendant drop apparatuses. Several possible reasons for the observed differences are discussed. A comparison of the dilatational modulus with the Gibbs elasticity is used to determine the presence of dilatational extra stresses at the interface. The isotherm and dilatational modulus of the insoluble component of the industrial surfactant Tween 80 are measured using this approach. The methods developed here also open the possibility for future study of the important role of finite size effects on microstructure formation and the resulting interfacial mechanics. PMID:27478885

  4. Pupil dilation as an index of preferred mutual gaze duration.

    PubMed

    Binetti, Nicola; Harrison, Charlotte; Coutrot, Antoine; Johnston, Alan; Mareschal, Isabelle

    2016-07-01

    Most animals look at each other to signal threat or interest. In humans, this social interaction is usually punctuated with brief periods of mutual eye contact. Deviations from this pattern of gazing behaviour generally make us feel uncomfortable and are a defining characteristic of clinical conditions such as autism or schizophrenia, yet it is unclear what constitutes normal eye contact. Here, we measured, across a wide range of ages, cultures and personality types, the period of direct gaze that feels comfortable and examined whether autonomic factors linked to arousal were indicative of people's preferred amount of eye contact. Surprisingly, we find that preferred period of gaze duration is not dependent on fundamental characteristics such as gender, personality traits or attractiveness. However, we do find that subtle pupillary changes, indicative of physiological arousal, correlate with the amount of eye contact people find comfortable. Specifically, people preferring longer durations of eye contact display faster increases in pupil size when viewing another person than those preferring shorter durations. These results reveal that a person's preferred duration of eye contact is signalled by physiological indices (pupil dilation) beyond volitional control that may play a modulatory role in gaze behaviour. PMID:27493767

  5. Diagnosis, prevalence, and screening of familial dilated cardiomyopathy

    PubMed Central

    Sweet, Mary; Taylor, Matthew R.G.; Mestroni, Luisa

    2016-01-01

    Introduction Dilated cardiomyopathy (DCM) is the most common cardiomyopathy and occurs often in families. As an inherited disease, understanding the significance of diagnostic procedures and genetic screening within families is of utmost importance. Areas covered Genetic studies have shown that in 30–40% of familial DCM (FDC) cases a causative genetic mutation can be identified. Successful genetic analysis is highly dependent on close examination of patient and family history, and clinical guidelines exist recommending genetic testing to aid in the evaluation of family members at risk of developing FDC. Clinical genetic testing offers a resource for families to identify the etiology of their disease, and in some cases may provide clinical prognostic insight. Expert Opinion As an inherited disease, future FCD studies will focus on elucidating the remaining 60–70% of genetic causes in inherited cases and the pathogenic mechanisms leading to the phenotype. Specifically, a focus on regulatory regions, copy number variation, genetic and environmental modifiers and functional confirmatory investigations will be essential. PMID:27547593

  6. Prevalence of Celiac Disease in Children with Idiopathic Dilated Cardiomyopathy

    PubMed Central

    Zahmatkeshan, Mozhgan; Fallahpoor, Mahsa; Amoozgar, Hamid

    2014-01-01

    Objective: This study aimed to evaluate the prevalence of celiac disease (CD) in the patients with dilated cardiomyopathy (DCM). Simultaneous presentation of these two diseases has been recently reported in some studies; however, few researches have been done on children. The sooner CD is diagnosed, the better the prognosis will be, especially in the patients with a chronic disease like DCM. Methods: In this study, 82 cases were screened for CD by measuring the level of anti-body against transglutaminase (anti tTG). These cases included 41 patients with DCM labeled according to clinical evaluation and echocardiography and 41 healthy children who had been referred for routine checkup. All the patients were between 1 and 18 years old. The expired patients and those with previous diagnosis of CD were excluded from the study. Besides, the patients with positive antibody results underwent intestinal biopsy to match the serology findings with histopathology of CD in the intestine. Finally, the data were analyzed by the SPSS statistical software (v. 16) and through t-test and Pearson correlation coefficient. Findings: According to the findings, 1/41 (2.5%) DCM cases had positive tTG antibody level and negative intestinal biopsy which is classified as potential CD in the children with DCM. In addition, 7/41 (17%) patients had borderline anti body level. A direct correlation was observed between age and anti tTG level. Conclusion: It is beneficial to assess CD in DCM children with unknown cause. PMID:25793066

  7. Late Gadolinium Enhancement in Patients with Nonischemic Dilated Cardiomyopathy.

    PubMed

    Memon, Sarfaraz; Ganga, Harsha V; Kluger, Jeffrey

    2016-07-01

    One-third of all patients with heart failure have nonischemic dilated cardiomyopathy (NIDM). Five-year mortality from NIDM is as high as 20% with sudden cardiac death (SCD) as the cause in 30% of the deaths. Currently, the left ventricular ejection fraction (LVEF) is used as the main criteria to risk stratify patients requiring an implantable cardioverter defibrillator (ICD) to prevent SCD. However, LVEF does not necessarily reflect myocardial propensity for electrical instability leading to ventricular tachycardia (VT) or ventricular fibrillation (VF). Due to the differential risk in various subgroups of patients for arrhythmic death, it is important to identify appropriate patients for ICD implantation so that we can optimize healthcare resources and avoid the complications of ICDs in individuals who are unlikely to benefit. We performed a systematic search and review of clinical trials of NIDM and the use of ICDs and cardiac magnetic resonance imaging with late gadolinium enhancement (LGE) for risk stratification. LGE identifies patients with NIDM who are at high risk for SCD and enables optimized patient selection for ICD placement, while the absence of LGE may reduce the need for ICD implantation in patients with NIDM who are at low risk for future VF/VT or SCD. PMID:27071516

  8. Deception in simplicity: hereditary phospholamban mutations in dilated cardiomyopathy.

    PubMed

    Young, Howard S; Ceholski, Delaine K; Trieber, Catharine A

    2015-02-01

    The sarcoplasmic reticulum (SR) calcium pump (SERCA) and its regulator phospholamban are required for cardiovascular function. Phospholamban alters the apparent calcium affinity of SERCA in a process that is modulated by phosphorylation via the β-adrenergic pathway. This regulatory axis allows for the dynamic control of SR calcium stores and cardiac contractility. Herein we focus on hereditary mutants of phospholamban that are associated with heart failure, such as Arg(9)-Cys, Arg(9)-Leu, Arg(9)-His, and Arg(14)-deletion. Each mutant has a distinct effect on PLN function and SR calcium homeostasis. Arg(9)-Cys and Arg(9)-Leu do not inhibit SERCA, Arg(14)-deletion is a partial inhibitor, and Arg(9)-His is comparable to wild-type. While the mutants have distinct functional effects on SERCA, they have in common that they cannot be phosphorylated by protein kinase A (PKA). Arg(9) and Arg(14) are required for PKA recognition and phosphorylation of PLN. Thus, mutations at these positions eliminate β-adrenergic control and dynamic cardiac contractility. Hydrophobic mutations of Arg(9) cause more complex changes in function, including loss of PLN function and dominant negative interaction with SERCA in heterozygous individuals. In addition, aberrant interaction with PKA may prevent phosphorylation of wild-type PLN and sequester PKA from other local subcellular targets. Herein we consider what is known about each mutant and how the synergistic changes in SR calcium homeostasis lead to impaired cardiac contractility and dilated cardiomyopathy. PMID:25563649

  9. Contemporary Outcome in Patients With Idiopathic Dilated Cardiomyopathy.

    PubMed

    Broch, Kaspar; Murbræch, Klaus; Andreassen, Arne Kristian; Hopp, Einar; Aakhus, Svend; Gullestad, Lars

    2015-09-15

    Outcome is better in patients with idiopathic dilated cardiomyopathy (IDC) than in ischemic heart failure (HF), but morbidity and mortality are nevertheless presumed to be substantial. Most data on the prognosis in IDC stem from research performed before the widespread use of current evidence-based treatment, including implantable devices. We report outcome data from a cohort of patients with IDC treated according to current HF guidelines and compare our results with previous figures: 102 consecutive patients referred to our tertiary care hospital with idiopathic IDC and a left ventricular ejection fraction <40% were included in a prospective cohort study. After extensive baseline work-up, follow-up was performed after 6 and 13 months. Vital status and heart transplantation were recorded. Over the first year of follow-up, the patients were on optimal pharmacological treatment, and 24 patients received implantable devices. Left ventricular ejection fraction increased from 26 ± 10% to 41 ± 11%, peak oxygen consumption increased from 19.5 ± 7.1 to 23.4 ± 7.8 ml/kg/min, and functional class improved substantially (all p values <0.001). After a median follow-up of 3.6 years, 4 patients were dead, and heart transplantation had been performed in 9 patients. According to our literature search, survival in patients with IDC has improved substantially over the last decades. In conclusion, patients with IDC have a better outcome than previously reported when treated according to current guidelines.

  10. Effect of dilatation on scalar dissipation in turbulent premixed flames

    SciTech Connect

    Swaminathan, N.; Bray, K.N.C.

    2005-12-01

    The scalar dissipation rate signifies the local mixing rate and thus plays a vital role in the modeling of reaction rate in turbulent flames. The local mixing rate is influenced by the turbulence, the chemical, and the molecular diffusion processes which are strongly coupled in turbulent premixed flames. Thus, a model for the mean scalar dissipation rate, and hence the mean reaction rate, should include the contributions of these processes. Earlier models for the scalar dissipation rate include only a turbulence time scale. In this study, we derive exact transport equations for the instantaneous and the mean scalar dissipation rates. Using these equations, a simple algebraic model for the mean scalar dissipation rate is obtained. This model includes a chemical as well as a turbulence time scale and its prediction compares well with direct numerical simulation results. Reynolds-averaged Navier-Stokes calculations of a test flame using the model obtained here show that the contribution of dilatation to local turbulent mixing rate is important to predict the propagation phenomenon.

  11. A conduit dilation model of methane venting from lake sediments

    USGS Publications Warehouse

    Scandella, B.P.; Varadharajan, C.; Hemond, Harold F.; Ruppel, C.; Juanes, R.

    2011-01-01

    Methane is a potent greenhouse gas, but its effects on Earth's climate remain poorly constrained, in part due to uncertainties in global methane fluxes to the atmosphere. An important source of atmospheric methane is the methane generated in organic-rich sediments underlying surface water bodies, including lakes, wetlands, and the ocean. The fraction of the methane that reaches the atmosphere depends critically on the mode and spatiotemporal characteristics of free-gas venting from the underlying sediments. Here we propose that methane transport in lake sediments is controlled by dynamic conduits, which dilate and release gas as the falling hydrostatic pressure reduces the effective stress below the tensile strength of the sediments. We test our model against a four-month record of hydrostatic load and methane flux in Upper Mystic Lake, Mass., USA, and show that it captures the complex episodicity of methane ebullition. Our quantitative conceptualization opens the door to integrated modeling of methane transport to constrain global methane release from lakes and other shallow-water, organic-rich sediment systems, and to assess its climate feedbacks.

  12. [Studies on the genetic susceptibility to dilated cardiomyopathy].

    PubMed

    Li, Y Y; Zhang, J N; Ma, W Z

    1993-01-01

    HLA-DQB1,-DRB1 genes of 27 Chinese patients with dilated cardiomyopathy (DCM), 7 high risk individuals in a DCM kindred and 17 normal control subjects were analysed with the use of restriction fragment length polymorphisms (RFLP) with full length DQB1 and DRB1 cDNA probes according to the standard and nomenclature of the Xth International Histocompatibility Workshop. The resulting restriction patterns allowed genotyping of HLA-DR and HLA-DQw. D-DQw8 frequency increased significantly in patients with DCM as compared with that of the controls (P < 0.05). D-DQw4 also increased in patients although no statistical significance was shown when Chi-square value was corrected with Yate's correction, whereas D-DQw5 overrepresented in controls (P < 0.05). Over half of the high risk individuals (4/7) in the familial DCM kindred carry D-DQw8 and D-DQw4. These results support the hypothesis that HLA class II genes were associated with an increased risk for DCM, HLA-DQB rather than -DRB may confer genetic susceptibility to DCM. PMID:8104770

  13. Simulation of Dilated Heart Failure with Continuous Flow Circulatory Support

    PubMed Central

    Wang, Yajuan; Loghmanpour, Natasha; Vandenberghe, Stijn; Ferreira, Antonio; Keller, Bradley; Gorcsan, John; Antaki, James

    2014-01-01

    Lumped parameter models have been employed for decades to simulate important hemodynamic couplings between a left ventricular assist device (LVAD) and the native circulation. However, these studies seldom consider the pathological descending limb of the Frank-Starling response of the overloaded ventricle. This study introduces a dilated heart failure model featuring a unimodal end systolic pressure-volume relationship (ESPVR) to address this critical shortcoming. The resulting hemodynamic response to mechanical circulatory support are illustrated through numerical simulations of a rotodynamic, continuous flow ventricular assist device (cfVAD) coupled to systemic and pulmonary circulations with baroreflex control. The model further incorporated septal interaction to capture the influence of left ventricular (LV) unloading on right ventricular function. Four heart failure conditions were simulated (LV and bi-ventricular failure with/without pulmonary hypertension) in addition to normal baseline. Several metrics of LV function, including cardiac output and stroke work, exhibited a unimodal response whereby initial unloading improved function, and further unloading depleted preload reserve thereby reducing ventricular output. The concept of extremal loading was introduced to reflect the loading condition in which the intrinsic LV stroke work is maximized. Simulation of bi-ventricular failure with pulmonary hypertension revealed inadequacy of LV support alone. These simulations motivate the implementation of an extremum tracking feedback controller to potentially optimize ventricular recovery. PMID:24465511

  14. Pupil dilation as an index of preferred mutual gaze duration

    PubMed Central

    Binetti, Nicola; Harrison, Charlotte; Coutrot, Antoine; Johnston, Alan; Mareschal, Isabelle

    2016-01-01

    Most animals look at each other to signal threat or interest. In humans, this social interaction is usually punctuated with brief periods of mutual eye contact. Deviations from this pattern of gazing behaviour generally make us feel uncomfortable and are a defining characteristic of clinical conditions such as autism or schizophrenia, yet it is unclear what constitutes normal eye contact. Here, we measured, across a wide range of ages, cultures and personality types, the period of direct gaze that feels comfortable and examined whether autonomic factors linked to arousal were indicative of people's preferred amount of eye contact. Surprisingly, we find that preferred period of gaze duration is not dependent on fundamental characteristics such as gender, personality traits or attractiveness. However, we do find that subtle pupillary changes, indicative of physiological arousal, correlate with the amount of eye contact people find comfortable. Specifically, people preferring longer durations of eye contact display faster increases in pupil size when viewing another person than those preferring shorter durations. These results reveal that a person's preferred duration of eye contact is signalled by physiological indices (pupil dilation) beyond volitional control that may play a modulatory role in gaze behaviour. PMID:27493767

  15. Mathematical Modeling of Subthreshold Resonant Properties in Pyloric Dilator Neurons

    PubMed Central

    Vazifehkhah Ghaffari, Babak; Kouhnavard, Mojgan; Aihara, Takeshi; Kitajima, Tatsuo

    2015-01-01

    Various types of neurons exhibit subthreshold resonance oscillation (preferred frequency response) to fluctuating sinusoidal input currents. This phenomenon is well known to influence the synaptic plasticity and frequency of neural network oscillation. This study evaluates the resonant properties of pacemaker pyloric dilator (PD) neurons in the central pattern generator network through mathematical modeling. From the pharmacological point of view, calcium currents cannot be blocked in PD neurons without removing the calcium-dependent potassium current. Thus, the effects of calcium (ICa) and calcium-dependent potassium (IKCa) currents on resonant properties remain unclear. By taking advantage of Hodgkin-Huxley-type model of neuron and its equivalent RLC circuit, we examine the effects of changing resting membrane potential and those ionic currents on the resonance. Results show that changing the resting membrane potential influences the amplitude and frequency of resonance so that the strength of resonance (Q-value) increases by both depolarization and hyperpolarization of the resting membrane potential. Moreover, hyperpolarization-activated inward current (Ih) and ICa (in association with IKCa) are dominant factors on resonant properties at hyperpolarized and depolarized potentials, respectively. Through mathematical analysis, results indicate that Ih and IKCa affect the resonant properties of PD neurons. However, ICa only has an amplifying effect on the resonance amplitude of these neurons. PMID:25960999

  16. Alleviation of Photoinhibition by Co-ordination of Chlororespiration and Cyclic Electron Flow Mediated by NDH under Heat Stressed Condition in Tobacco

    PubMed Central

    Li, Qinghua; Yao, Zheng-Ju; Mi, Hualing

    2016-01-01

    much more in the mutant. The results suggest that chlororespiration and cyclic electron flow mediated by NDH may coordinate to alleviate the over-reduction of stroma, thus to keep operation of CO2 assimilation at certain extent under heat stress condition. PMID:27066014

  17. Significance of Sonographically Demonstrated Ureteral Dilatation in Evaluation of Vesicoureteral Reflux Verified with Voiding Urosonography in Children with Urinary Tract Infection

    PubMed Central

    Carovac, Aladin; Zubovic, Sandra Vegar; Carovac, Marklena; Pasic, Irmina Sefic

    2015-01-01

    Objectives: The aim of this study was to determine sensitivity, specificity, and predictive values of sonographically demonstrated ureteral dilatation in detecting vesicoureteral reflux (VUR). Methods: Ethical approval from the Ethical Committee of Clinical Center University of Sarajevo and parental consent were obtained for this prospective study involving 120 children with history of urinary tract infections (UTIs). Ultrasound examination included the evaluation of the urinary tract, with a special emphasis on evaluation of ureteral dilatation. Voiding urosonography (VUS) was carried out according to a standard protocol with the use of ultrasound contrast agent Sono Vue of second generation. Ureteral diameter greater than 3 mm was considered pathological. Proven VUR was graded into one of three stages. Results: Infectio tracti urinarii recidivans was referral diagnosis in the majority of patients. The average age of patients was 4.33 ± 3.88 years (from 2 months to 16 years of age). VUS findings were normal in 59 (49.2%), and pathological in 61 (50.8%) patients. Statistical analysis showed significant correlation between type and grade of VUR. Our data confirmed predominance of VUR in females and in children under the age of 5. Statistically significant correlation between ureteral dilatation and the existence of VUR was found, with relatively high sensitivity (67.2%), specificity (81.4%), and high positive (78.8%) and negative predictive value (70.6%), total diagnostic accuracy of 74.2% in detecting VUR, and significantly increased probability (20 – 25%) of detecting VUR in patients with sonographically confirmed ureteral dilatation. Conclusion: Sonographically confirmed ureteral dilatation can be used as a predictor of VUR in children with UTIs, and in combination with other predictors, might find a place in an evidence-based selective strategy in children with suspected VUR. PMID:26635432

  18. Exercise improves the dilatation function of mesenteric arteries in postmyocardial infarction rats via a PI3K/Akt/eNOS pathway-mediated mechanism.

    PubMed

    Wang, Youhua; Wang, Shengpeng; Wier, W Gil; Zhang, Quanjiang; Jiang, Hongke; Li, Qiuxia; Chen, Shengfeng; Tian, Zhenjun; Li, Youyou; Yu, Xiaojiang; Zhao, Ming; Liu, Jinjun; Yang, Jing; Zhang, Jing; Zang, Weijin

    2010-12-01

    Myocardial infarction (MI) has been shown to induce endothelial dysfunction in peripheral resistance arteries and thus increase peripheral resistance. This study was designed to investigate the underlying mechanisms of post-MI-related dysfunctional dilatation of peripheral resistance arteries and, furthermore, to examine whether exercise may restore dysfunctional dilatation of peripheral resistance arteries. Adult male Sprague-Dawley rats were divided into three groups: sham-operated, MI, and MI + exercise. Ultrastructure and relaxation function of the mesenteric arteries, as well as phosphatidylinositol-3 kinase (PI3K), Akt kinases (Akt), endothelial nitric oxide synthase (eNOS) activity, and phosphorylation of PI3K, Akt, and eNOS by ACh were determined. Post-MI rats exhibited pronounced ultrastructural changes in mesenteric artery endothelial cells and endothelial dysfunction. In addition, the activities of PI3K, Akt, and eNOS, and their phosphorylation by ACh were significantly attenuated in mesenteric arteries (P < 0.05-0.01). After 8 wk of exercise, not only did endothelial cells appeared more normal in structure, but also ameliorated post-MI-associated mesenteric arterial dysfunction, which were accompanied by elevated activities of PI3K, Akt, and eNOS, and their phosphorylation by ACh (P < 0.05-0.01). Importantly, inhibition of either PI3K or eNOS attenuated exercise-induced restoration of the dilatation function and blocked PI3K, Akt, and eNOS phosphorylation by ACh in the mesenteric arteries. These data demonstrate that MI induces dysfunctional dilation of peripheral resistance arteries by degradation of endothelial structural integrity and attenuating PI3K-Akt-eNOS signaling. Exercise may restore dilatation function of peripheral resistance arteries by protecting endothelial structural integrity and increasing PI3K-Akt-eNOS signaling cascades.

  19. Development of trabecular bone surrogates for kyphoplasty-balloon dilatation training.

    PubMed

    Hollensteiner, Marianne; Samrykit, Markus; Hess, Michael; Fuerst, David; Schrempf, Andreas

    2015-01-01

    Vertebral compression fractures can limit quality of life. Cement augmentation techniques show good results in attaining pain relief. Kyphoplasty enables a better restoration of vertebra height due to a dilatable balloon tamp, which is inflated in the fractured vertebra. Surgical training of vertebral cement augmentation techniques is currently performed on patients or specimens. To enable another training possibility for surgical residents, a new hybrid patient simulator was developed. Artificial vertebrae allocate a realistic haptic feedback during needle insertion. Based on these results, new polyurethane foam recipes were developed to either enable a realistic needle insertion as well as a balloon tamp dilatation. Needle insertion forces of the newly developed foams were compared against commercially available artificial trabecular bone material and balloon tamp dilatations were performed in manufactured materials. Based on the matching needle insertion forces, two suitable material compositions for needle insertion and balloon dilatation training were found. This investigation is considered as a prior study before evaluation on human specimen. PMID:26737440

  20. [Early complications of pneumatic dilatation in the treatment of primary motility disorders of the esophagus].

    PubMed

    Sala, T; Ponce, J; Pertejo, V; Linares, M; Garrigues, V; Berenguer, J

    1990-04-01

    We analyze the incidence and evolution of the early complications of 96 consecutive patients with primary esophagus motor disorders, treated with pneumatic dilatation under endoscopic control (1.4 sessions per patient). In 4 (0.042/patient, 0.029/dilatation) patients the esophagus was perforated; the diagnosis was made in the first 24 hours; pneumomediastinum was a constant finding in the radiological exploration. In three cases the complication was suspected because of the apparition of sustained thoracic pain after the dilatation maneuver and in one case the presentation symptom was bleeding of cardial mucosa, larger than usual, at the end of the dilatation. The four patients evolved favorably with conservative treatment (avoidance of oral food intake, gastroesophageal aspiration, antibiotic therapy and parenteral nutrition).

  1. Heller's cardiomyotomy compared with pneumatic dilatation for treatment of oesophageal achalasia.

    PubMed

    Mäkelä, J; Kiviniemi, H; Laitinen, S

    1991-01-01

    The records of 30 patients treated for oesophageal achalasia between 1976 and 1988 were analysed retrospectively. Early and late results were collected to compare the safety and efficacy of Heller's myotomy (n = 13) and pneumatic dilatation (n = 17). Unsatisfactory immediate postoperative results were found in 4 of 13 of the patients who had undergone myotomy (31%) and in 4 of the 17 patients treated by pneumatic dilatation (24%). More patients had improved swallowing during the first postoperative year after myotomy, but this difference ceased with time. The severity of the symptoms affected the results, and dilatations that had to be repeated more than twice were ineffective. We conclude that pneumatic dilatation is as safe as Heller's myotomy, and that although the early results are significantly better after myotomy, the late results are similar.

  2. Rare Case of Takayasu Arteritis with Concurrent Aneurysmal Dilation and Stenosis

    PubMed Central

    Skeik, Nedaa; Rodriguez, Alexander J.; Engstrom, Bjorn

    2015-01-01

    Takayasu arteritis is a rare, chronic large vessel vasculitis that primarily affects women aged 10 to 40 years of Asian descent. The inflammatory processes of the disease can result in stenosis and/or occlusion of the aorta and its branches, causing a wide range of symptoms. Rarely, damage of the elastic lamina or muscular media can cause aneurysmal dilation of the affected vessel. Diagnosis is based on the clinical presentation, laboratory proof of inflammation, and imaging finding of wall thickening in the acute phase and later arterial stenosis or occlusion. Management includes disease control with immunosuppression and some patients might require revascularization. Here, we present a rare case of Takayasu arteritis with both right common carotid artery aneurysmal dilation and stenosis at a conforming site. Although aneurysmal dilation has been sparsely reported in the Takayasu arteritis literature, our case may represent the distinct finding of concomitant dilation and stenosis in this disease. PMID:26417195

  3. Ectopic opening of cystic dilatation of the ejaculatory duct into enlarged prostatic utricle.

    PubMed

    Lin, Jian-Zhong; Wu, Hong-Fei; Wang, Ji-Chen; Le, Mei-Zhao; Yu, Hong-Bo; Zhou, He-Tong

    2012-01-01

    A 28-year-old man was referred to our department for the management of recurrent hemospermia during the past 5 years. Genital examination and hormonal levels were normal. Semen analysis showed no change in volume and pH; however, hemospermia and asthenozoospermia were observed. Ultrasonography and computed tomography scan revealed the presence of a cystic lesion with calcification in the terminal part of seminal vesicles adjoining the prostate gland. The following vasography and endoscopic retrograde urethrography demonstrated 2 communicating cystic dilatations arising from the verumontanum. The diagnosis of cystic dilatation of the ejaculatory duct opening into an enlarged prostatic utricle was reached. Transurethral unroofing of the cyst was separately performed with a successful outcome. The characteristic of the 2 cystic dilatations was confirmed by pathologic examination. To the best of our knowledge, this is the first case of ectopic cystic dilatation of the ejaculatory duct opening into an enlarged prostatic utricle.

  4. Treatment of Plummer-Vinson syndrome with Savary-Gilliard dilatation.

    PubMed

    Yasawy, Mohamed I

    2004-04-01

    The association of postcricoid dysphagia, iron deficiency anemia and upper esophageal webs is known as the Plummer-Vinson syndrome (PVS). It is predominantly a disease of middle aged females. Four patients with cervical web of the esophagus were studied, dysphagia was mostly for solids, which were non-progressive and were present for years before they presented. Initial treatment in 3 patients consisted of esophageal dilatation with savary bougies after initial rupture of the web by endoscope. In one case, due to failure to visualize the esophageal lumen by fluoroscopy guidance, guide wire was introduced and breaking of the web was performed by the endoscope, followed by bougie dilatation. In 4 patients, webs were ruptured by the endoscope and had a single session of dilatation, with no recurrence during the 3-year period of follow up. Endoscopic esophageal dilatation is simple and the procedure of choice in the treatment of "PVS" and cervical web of the esophagus.

  5. Reduction of cervical resistance by prostaglandin suppositories prior to dilatation for induced abortion.

    PubMed

    Dingfelder, J R; Brenner, W E; Hendricks, C H; Staurovsky, L G

    1975-05-01

    Several recent reports citing increased rates of prematurity among women who have had induced first-trimester abortion suggest that forceful cervical dilatation may result in cervical incompetence in future pregnancy. There appear to be conflicting clinical impressions regarding the effectiveness on cervical softening and the reduction of cervical resistance produced by various prostaglandins. The development of the Electronic Force Monitor which is capable of precise measurement of the forces encountered in overcoming resistance during dilatation provided objective evidence with which to evaluate the effects of vaginally administered prostaglandin E2 and F2alpha suppositories. Suppositories were administered 3 hours prior to cervical dilatation, after which suction curettage was performed. Compared to the nonmedicated control group, patients receiving PGF2alpha suppositories exhibited greatly reduced cervical resistance, in some cases permitting direct introduction of the suction curette without need for any preliminary dilatation. Those patients receiving PGE2 suppositories showed an intermediate degree of cervical softening.

  6. FATAL GASTRIC DILATION IN TWO ADULT BLACK-FOOTED FERRETS (MUSTELA NIGRIPES).

    PubMed

    Hinton, Jenna D; Aitken-Palmer, Copper; Joyner, Priscilla H; Ware, Lisa; Walsh, Timothy F

    2016-03-01

    Acute gastric dilation resulting in death was identified in two adult black-footed ferrets (Mustela nigripes) housed at the Smithsonian Conservation Biology Institute in Front Royal, Virginia. Both individuals were adult males (3 and 5 yr) and previously clinically healthy prior to the event. The etiology of gastric dilation in both cases could not be definitively determined, and necropsy revealed severe cardiovascular compromise secondary to bloat. Limited literature is available regarding a syndrome of this type in adult black-footed ferrets. Differential diagnoses considered included gastric dilatation volvulus (GDV), severe gastric distention of unknown origin, and gastric outflow obstruction. Given the severity of this syndrome and the findings in these two cases, acute gastric dilation should be considered in black-footed ferrets presenting with acute abdominal distention, respiratory distress, and cardiovascular compromise. PMID:27010305

  7. Eustachian Tube Dilation via a Transtympanic Approach in 6 Cadaver Heads: A Feasibility Study.

    PubMed

    Dean, Marc; Chao, Wei-Chieh; Poe, Dennis

    2016-10-01

    The goal of this study was to evaluate the feasibility of endoscopic transtympanic balloon dilation of the cartilaginous eustachian tube. To accomplish this, transtympanic balloon dilation of the cartilaginous eustachian tube was performed on 11 eustachian tubes (6 cadaver heads). The balloon catheter was introduced and passed through the protympanic orifice of the eustachian tube transtympanically under endoscopic view and cannulated without incident in all cadavers. Computed tomography was then performed postprocedure to evaluate for inadvertent dilation of the bony eustachian tube, adverse placement of the balloon, or any bony fractures. The balloon was seen to be successfully inflated in the cartilaginous portion without damage to surrounding structures in all cases. This demonstrates that under endoscopic guidance, the protympanic orifice of the eustachian tube can be feasibly cannulated and reliably traversed, allowing for targeted dilation of the cartilaginous eustachian tube from a transtympanic approach.

  8. Long-term outcome of conventional endotracheal tube balloon dilation of tracheal stenosis in a dog

    PubMed Central

    Kahane, Nili; Segev, Gilad

    2014-01-01

    This report describes a successful dilation of tracheal stenosis in a 16-year-old dog using a conventional endotracheal tube balloon. This technique should be considered as palliative treatment when owners decline other therapeutic options. PMID:24381344

  9. Efficient algorithms for dilated mappings of binary trees

    NASA Technical Reports Server (NTRS)

    Iqbal, M. Ashraf

    1990-01-01

    The problem is addressed to find a 1-1 mapping of the vertices of a binary tree onto those of a target binary tree such that the son of a node on the first binary tree is mapped onto a descendent of the image of that node in the second binary tree. There are two natural measures of the cost of this mapping, namely the dilation cost, i.e., the maximum distance in the target binary tree between the images of vertices that are adjacent in the original tree. The other measure, expansion cost, is defined as the number of extra nodes/edges to be added to the target binary tree in order to ensure a 1-1 mapping. An efficient algorithm to find a mapping of one binary tree onto another is described. It is shown that it is possible to minimize one cost of mapping at the expense of the other. This problem arises when designing pipelined arithmetic logic units (ALU) for special purpose computers. The pipeline is composed of ALU chips connected in the form of a binary tree. The operands to the pipeline can be supplied to the leaf nodes of the binary tree which then process and pass the results up to their parents. The final result is available at the root. As each new application may require a distinct nesting of operations, it is useful to be able to find a good mapping of a new binary tree over existing ALU tree. Another problem arises if every distinct required binary tree is known beforehand. Here it is useful to hardwire the pipeline in the form of a minimal supertree that contains all required binary trees.

  10. Use and outcomes of amplatz renal dilator for treatment of urethral strictures

    PubMed Central

    Akkoc, Ali; Aydin, Cemil; Kartalmıs, Mahir; Topaktas, Ramazan; Altin, Selcuk; Yilmaz, Yakup

    2016-01-01

    ABSTRACT Introduction Urethral stricture disease is still a major problem in men. Many procedures are available for the treatment of urethral strictures; urethral dilatation is one of the oldest. The blind dilatation of urethral strictures may be a difficult and potentially dangerous procedure. The purpose of this study was to describe safe urethral dilatation using amplatz renal dilator and to report outcomes. Materials and Methods From 2010 to 2014, a total of 26 men with primary urethral strictures were managed by urethral dilatation using amplatz renal dilators. The parameters analyzed included presentation of patients, retrograde urethrography (RGU) findings, pre-and postoperative maximum flow rate (Qmax) on uroflowmetry (UF) and post-void residual urine (PVR). Patients were followed-up at 1.6 and 12 months. The technique described in this paper enables such strictures to be safely dilated after endoscopic placement of a suitable guidewire and stylet over which amplatz renal dilators are introduced. Results The mean age of the patients was 57.6 (35–72) years. The median stricture length was 0.82 (0.6–1.5)cm. Pre-operative uroflowmetry showed Qmax of 7.00 (4–12) mL/sec and ultrasonography showed PVR of 75.00 (45–195)mL. Postoperatively, Qmax improved to 18.00 (15–22)mL/sec (p<0.001) at 1 month, 17.00 (13–21)mL/sec (p<0.001) at 6 months and 15.00 (12–17)mL/sec (p<0.001) at 12 months. The post-operative PVR values were 22.50 (10–60)mL (p<0.001), 30.00 (10–70)mL (p<0.001) and 30.00 (10–70) mL (p<0.001) at 1.6 12 months, respectively. The median procedure time was 15.00 (12–22) minutes. None of the patients had a recurrence during a 12-month period of follow-up. Conclusion Urethral dilatation with amplatz renal dilators avoids the risks associated with blind dilatation techniques. This tecnique is a safe, easy, well-tolerated and cost-effective alternative for treatment of urethral strictures. PMID:27256192

  11. The Role of Transtympanic Dilatation of the Eustachian Tube During Chronic Ear Surgery.

    PubMed

    Tarabichi, Muaaz; Kapadia, Mustafa

    2016-10-01

    Endoscopic technique allows visualization of the protympanic segment of the eustachian tube in patients undergoing chronic ear surgery. Balloon dilatation of the area can be undertaken with clear widening of the obstructed areas. This article discusses the authors' approach and experience with transtympanic dilatation of the eustachian tube. It includes case selection, technique, immediate postprocedure evaluation, and results, with multiple case presentations and videos. PMID:27565385

  12. Vaginal Examination Simulation Using Citrus Fruit to Simulate Cervical Dilation and Effacement

    PubMed Central

    Shea, Kathleen L

    2015-01-01

    This technical report describes the creation and use of a cervical dilation and effacement model in a pre-licensure nursing course in reproductive health. Vaginal examination is typically taught in reproductive health courses; however, nursing students do not always have sufficient opportunity to practice on actual patients. This low-cost task-training model provides undergraduate nursing students the opportunity to experience performing a vaginal examination to assess for cervical dilation and effacement during the labor process. PMID:26457235

  13. Teleological Reasoning in 4-Month-Old Infants: Pupil Dilations and Contextual Constraints

    PubMed Central

    Gredebäck, Gustaf; Melinder, Annika

    2011-01-01

    Four-month-old infants were presented with feeding actions performed in a rational or irrational manner. Infants reacted to the irrational feeding actions by dilating their pupils, but only in the presence of rich contextual constraints. The study demonstrates that teleological processes are online at 4 months of age and illustrates the usefulness of pupil dilations as a measure of social cognitive processes early in infancy. PMID:22039499

  14. Depth inloop resampling using dilation filter for free viewpoint video system

    NASA Astrophysics Data System (ADS)

    Lee, Seok; Lee, Seungsin; Wey, Hocheon; Lee, Jaejoon; Park, Dusik

    2013-03-01

    A depth dilation filter is proposed for free viewpoint video system based on mixed resolution multi-view video plus depth (MVD). By applying gray scale dilation filter to depth images, foreground regions are extended to background region, and synthesis artifacts occur out of boundary edge. Thus, objective and subjective quality of view synthesis result is improved. A depth dilation filter is applied to inloop resampling part in encoding/decoding, and post processing part after decoding. Accurate view synthesis is important in virtual view generation for autostereoscopic display, moreover there are many coding tools which use view synthesis to reduce interview redundancy in 3D video coding such as view synthesis prediction (VSP) and depth based motion vector prediction (DMVP), and compression efficiency can be improved by accurate view synthesis. Coding and synthesis experiments are performed for performance evaluation of a dilation filter with MPEG test sequences. Dilation filter was implemented on the top of the MPEG reference software for AVC based 3D video coding. By applying a depth dilation filter, BD-rate gains of 0.5% and 6.0% in terms of PSNR of decoded views and synthesized views, respectively.

  15. Using the adaptive SMA composite cylinder concept to reduce radial dilation in composite pressure vessels

    NASA Astrophysics Data System (ADS)

    Paine, Jeffrey S.; Rogers, Craig A.

    1995-05-01

    Composite materials are widely used in the design of pressurized gas and fluid vessels for applications ranging from underground gasoline storage tanks to rocket motors for the space shuttle. In the design of a high pressure composite vessel (Pi > 12 Ksi), thick-wall (R/h < 15) vessels are required. For efficient material use in composite material vessels, the radial dilation (expansion or swelling) of the composite vessel can often approach values nearing 2 percent of the diameter. Over long periods of internal pressure loading over elevated temperatures, composite material cylinders may also experience substantial creep. The short term dilation and long term creep are not problematic for applications requiring only the containment of the pressurized fluid. In applications where metallic liners are required, however, substantial dilation and creep causes plastic yielding which leads to reduced fatigue life. To applications such as a hydraulic accumulator, where a piston is employed to fit and seal the fluid in the composite cylinder, the dilation and creep may allow leakage and pressure loss around the piston. A concept called the adaptive composite cylinder is experimentally presented. Shape memory alloy wire in epoxy resin is wrapped around or within polymer matrix composite cylinders to reduce radial dilation of the cylinder. Experimental results are presented that demonstrate the ability of the SMA wire layers to reduce radial dilation. Results from experimental testing of the recovery stress fatigue response of nitinol shape memory alloy wires is also presented.

  16. Impairment of nitric oxide synthase-dependent dilatation of cerebral arterioles during infusion of nicotine.

    PubMed

    Fang, Qin; Sun, Hong; Mayhan, William G

    2003-02-01

    The effects of nicotine on nitric oxide synthase (NOS)-dependent reactivity of cerebral arterioles remain uncertain. Our first goal was to examine whether infusion of nicotine alters NOS-dependent reactivity of cerebral arterioles. Our second goal was to examine the mechanisms that may account for the effects of nicotine on cerebral arterioles. We measured the diameter of pial arterioles to NOS-dependent (ADP and acetylcholine) and NOS-independent (nitroglycerin) agonists before and after the infusion of nicotine (2 microg x kg(-1) x min(-1) iv for 30 min, followed by a maintenance dose of 0.35 microg x kg(-1) x min(-1)). ADP- and acetylcholine-induced vasodilatation was impaired after the infusion of nicotine. In contrast, nicotine did not alter vasodilatation to nitroglycerin. Next, we examined whether the impaired responses of pial arterioles during infusion of nicotine may be related to oxygen radicals. We found that application of superoxide dismutase or tetrahydrobiopterin during infusion of nicotine could prevent impaired NOS-dependent vasodilatation. Thus acute exposure of cerebral vessels to nicotine specifically impairs NOS-dependent dilatation via the production of oxygen radicals possibly related to an alteration in the utilization of tetrahydrobiopterin.

  17. Sensitivity analysis of left ventricle with dilated cardiomyopathy in fluid structure simulation.

    PubMed

    Chan, Bee Ting; Abu Osman, Noor Azuan; Lim, Einly; Chee, Kok Han; Abdul Aziz, Yang Faridah; Abed, Amr Al; Lovell, Nigel H; Dokos, Socrates

    2013-01-01

    Dilated cardiomyopathy (DCM) is the most common myocardial disease. It not only leads to systolic dysfunction but also diastolic deficiency. We sought to investigate the effect of idiopathic and ischemic DCM on the intraventricular fluid dynamics and myocardial wall mechanics using a 2D axisymmetrical fluid structure interaction model. In addition, we also studied the individual effect of parameters related to DCM, i.e. peak E-wave velocity, end systolic volume, wall compliance and sphericity index on several important fluid dynamics and myocardial wall mechanics variables during ventricular filling. Intraventricular fluid dynamics and myocardial wall deformation are significantly impaired under DCM conditions, being demonstrated by low vortex intensity, low flow propagation velocity, low intraventricular pressure difference (IVPD) and strain rates, and high-end diastolic pressure and wall stress. Our sensitivity analysis results showed that flow propagation velocity substantially decreases with an increase in wall stiffness, and is relatively independent of preload at low-peak E-wave velocity. Early IVPD is mainly affected by the rate of change of the early filling velocity and end systolic volume which changes the ventriculo:annular ratio. Regional strain rate, on the other hand, is significantly correlated with regional stiffness, and therefore forms a useful indicator for myocardial regional ischemia. The sensitivity analysis results enhance our understanding of the mechanisms leading to clinically observable changes in patients with DCM. PMID:23825628

  18. Constraining friction, dilatancy and effective stress with earthquake rates in the deep crust

    NASA Astrophysics Data System (ADS)

    Beeler, N. M.; Thomas, A.; Burgmann, R.; Shelly, D. R.

    2015-12-01

    Similar to their behavior on the deep extent of some subduction zones, families of recurring low-frequency earthquakes (LFE) within zones of non-volcanic tremor on the San Andreas fault in central California show strong sensitivity to stresses induced by the tides. Taking all of the LFE families collectively, LFEs occur at all levels of the daily tidal stress, and are in phase with the very small, ~200 Pa, shear stress amplitudes while being uncorrelated with the ~2 kPa tidal normal stresses. Following previous work we assume LFE sources are small, persistent regions that repeatedly fail during shear within a much larger scale, otherwise aseismically creeping fault zone and that the correlation of LFE occurrence reflects modulation of the fault creep rate by the tidal stresses. We examine the predictions of laboratory-observed rate-dependent dilatancy associated with frictional slip. The effect of dilatancy hardening is to damp the slip rate, so high dilatancy under undrained pore pressure reduces modulation of slip rate by the tides. The undrained end-member model produces: 1) no sensitivity to the tidal normal stress, as first suggested in this context by Hawthorne and Rubin [2010], and 2) fault creep rate in phase with the tidal shear stress. Room temperature laboratory-observed values of the dilatancy and friction coefficients for talc, an extremely weak and weakly dilatant material, under-predict the observed San Andreas modulation at least by an order of magnitude owing to too much dilatancy. This may reflect a temperature dependence of the dilatancy and friction coefficients, both of which are expected to be zero at the brittle-ductile transition. The observed tidal modulation constrains the product of the friction and dilatancy coefficients to be at most 5 x 10-7 in the LFE source region, an order of magnitude smaller than observed at room temperature for talc. Alternatively, considering the predictions of a purely rate-dependent talc friction would

  19. A Two-Phase Solid/Fluid Model for Dense Granular Flows Including Dilatancy Effects

    NASA Astrophysics Data System (ADS)

    Mangeney, Anne; Bouchut, Francois; Fernandez-Nieto, Enrique; Narbona-Reina, Gladys

    2015-04-01

    We propose a thin layer depth-averaged two-phase model to describe solid-fluid mixtures such as debris flows. It describes the velocity of the two phases, the compression/dilatation of the granular media and its interaction with the pore fluid pressure, that itself modifies the friction within the granular phase (Iverson et al., 2010). The model is derived from a 3D two-phase model proposed by Jackson (2000) based on the 4 equations of mass and momentum conservation within the two phases. This system has 5 unknowns: the solid and fluid velocities, the solid and fluid pressures and the solid volume fraction. As a result, an additional equation inside the mixture is necessary to close the system. Surprisingly, this issue is inadequately accounted for in the models that have been developed on the basis of Jackson's work (Bouchut et al., 2014). In particular, Pitman and Le replaced this closure simply by imposing an extra boundary condition at the surface of the flow. When making a shallow expansion, this condition can be considered as a closure condition. However, the corresponding model cannot account for a dissipative energy balance. We propose here an approach to correctly deal with the thermodynamics of Jackson's equations. We close the mixture equations by a weak compressibility relation involving a critical density, or equivalently a critical pressure. Moreover, we relax one boundary condition, making it possible for the fluid to escape the granular media when compression of the granular mass occurs. Furthermore, we introduce second order terms in the equations making it possible to describe the evolution of the pore fluid pressure in response to the compression/dilatation of the granular mass without prescribing an extra ad-hoc equation for the pore pressure. We prove that the energy balance associated with this Jackson closure is dissipative, as well as its thin layer associated model. We present several numerical tests for the 1D case that are compared to the

  20. A Two-Phase Solid/Fluid Model for Dense Granular Flows Including Dilatancy Effects

    NASA Astrophysics Data System (ADS)

    Mangeney, A.; Bouchut, F.; Fernández-Nieto, E. D.; Narbona-Reina, G.; Kone, E. H.

    2014-12-01

    We propose a thin layer depth-averaged two-phase model to describe solid-fluid mixtures such as debris flows. It describes the velocity of the two phases, the compression/dilatation of the granular media and its interaction with the pore fluid pressure, that itself modifies the friction within the granular phase (Iverson et al., 2010). The model is derived from a 3D two-phase model proposed by Jackson (2000) based on the 4 equations of mass and momentum conservation within the two phases. This system has 5 unknowns: the solid and fluid velocities, the solid and fluid pressures and the solid volume fraction. As a result, an additional equation inside the mixture is necessary to close the system. Surprisingly, this issue is inadequately accounted for in the models that have been developed on the basis of Jackson's work (Bouchut et al., 2014). In particular, Pitman and Le replaced this closure simply by imposing an extra boundary condition at the surface of the flow. When making a shallow expansion, this condition can be considered as a closure condition. However, the corresponding model cannot account for a dissipative energy balance. We propose here an approach to correctly deal with the thermodynamics of Jackson's equations. We close the mixture equations by a weak compressibility relation involving a critical density, or equivalently a critical pressure. Moreover, we relax one boundary condition, making it possible for the fluid to escape the granular media when compression of the granular mass occurs. Furthermore, we introduce second order terms in the equations making it possible to describe the evolution of the pore fluid pressure in response to the compression/dilatation of the granular mass without prescribing an extra ad-hoc equation for the pore pressure. We prove that the energy balance associated with this Jackson closure is dissipative, as well as its thin layer associated model. We present several numerical tests for the 1D case that are compared to the

  1. Wearing weighted backpack dilates subjective visual duration: the role of functional linkage between weight experience and visual timing.

    PubMed

    Jia, Lina; Shi, Zhuanghua; Feng, Wenfeng

    2015-01-01

    Bodily state plays a critical role in our perception. In the present study, we asked the question whether and how bodily experience of weights influences time perception. Participants judged durations of a picture (a backpack or a trolley bag) presented on the screen, while wearing different weight backpacks or without backpack. The results showed that the subjective duration of the backpack picture was dilated when participants wore a medium weighted backpack relative to an empty backpack or without backpack, regardless of identity (e.g., color) of the visual backpack. However, the duration dilation was not manifested for the picture of trolley bag. These findings suggest that weight experience modulates visual duration estimation through the linkage between the wore backpack and to-be-estimated visual target. The congruent action affordance between the wore backpack and visual inputs plays a critical role in the functional linkage between inner experience and time perception. We interpreted our findings within the framework of embodied time perception. PMID:26441748

  2. Metabolomic and Genomic Markers of Atherosclerosis as Related to Oxidative Stress, Inflammation, and Vascular Function in Twin Astronauts

    NASA Technical Reports Server (NTRS)

    Lee, Stuart M. C.; Rana, Brinda K.; Stenger, Michael B.; Sears, Dorothy D.; Smith, Scott M.; Macias, Brandon R.; Hargens, Alan R.; Sharma, Kumar; De Vivo, Immaculata

    2016-01-01

    atherosclerosis risk factors. Conversely, these will not be observed in the ground-based twin. Methods: We will measure blood and urine biomarkers of oxidative stress and inflammation as well as arterial structure and function (carotid intima-medial thickness and brachial artery flow-mediated dilation) in one twin astronaut before, during, and after long-duration spaceflight and in his twin serving as a ground-based control. Furthermore, we will measure metabolomics (targeted and untargeted approaches) and genomic markers (DNA methylation, mRNA gene expression, telomere length) to elucidate the molecular mechanisms involved. A panel of biomarkers of oxidative and inflammatory stress will be measured in venous blood samples and 24-hour (in-flight) and 48-hour (pre- and post-flight) urine pools twice before flight, early (flight days 15 and 60) and late (2 weeks before landing) during the mission, and early in the post-flight recovery phase (approximately 3-5 days after landing). Arterial structure, assessed from measures of intima-media thickness, will be measured at the same times. Arterial function will be assessed using brachial flow-mediated dilation, a well-validated measure used to assess endothelium-dependent vasodilation and a sensitive predictor of atherosclerotic risk, only before and after spaceflight. Discussion: Pre- and in-flight data collection is in progress for the space-flown twin, and similar data have been obtained from the ground-based twin. Blood and urine samples will be batch processed when received from ISS after the conclusion of the 1-year mission. Results from these individual subjects will be compared to the larger complement of subjects participating in the companion study currently ongoing in ISS astronauts.

  3. Total plasma proANP increases with atrial dilatation in horses.

    PubMed

    Van Der Vekens, N; Hunter, I; Timm, A; Decloedt, A; De Clercq, D; Deprez, P; Goetze, J P; van Loon, G

    2015-12-19

    Equine atrial natriuretic peptide (ANP) plasma concentrations are correlated with left atrial size. However, species-specific assays are lacking and the results from human assays are poorly reproducible. A new methodology called processing independent analysis (PIA) that measures the total proANP product in plasma has proven to be successful in human medicine, but has never been used in horses. The aims were to establish an equine proANP reference interval by measurement of the total proANP product using PIA and to examine the proANP concentrations in horses with atrial dilatation. Sample stability was studied by comparison of storage at -80°C and -20°C. Plasma samples were obtained from 23 healthy horses, 12 horses with moderate or severe valvular regurgitation without atrial dilatation and 42 horses with valvular regurgitation and atrial dilatation. The proANP concentration was significantly (P<0.001) higher in horses with atrial dilatation (761.4 (442.1-1859.1) pmol/l) than in healthy horses (491.6 (429.5-765.9) pmol/l; P<0.001) or horses with cardiac disease but without atrial dilatation (544.4 (457.0-677.6) pmol/l). A cut-off value (573.8 pmol/l) for detection of atrial dilatation was calculated. Sample storage at -80°C did not differ from sample storage at -20°C. The measurement of total proANP in plasma detects atrial dilatation in horses and may be useful for clinical evaluation in equine medicine.

  4. Co-seismic dilatational strain in the far field of great earthquakes

    NASA Astrophysics Data System (ADS)

    Zhang, Yan; Fu, Li-Yun; Wang, Chi-yuen; Yan, Rui; Zhao, Lian-feng

    2016-04-01

    The mechanism of the coseismic dilatational strain has been a topic of active debate. Recent studies show that the co-seismic change of dilatational strain in the far field of large earthquakes is often far greater than that predicted from static strain theory, but the underlying mechanism is not understood. Here we study this mechanism by comparing the tidal responses of crustal strain and water level documented in the Fuxin well, northeastern China, before and after three great earthquakes (the 2008 Mw 7.9 Wenchuan earthquake, the 2011 Mw 9.1 Tohoku earthquake and the 2012 Mw 8.6 Sumatra earthquake). We show that, before each earthquake, the phase of water-level fluctuation lagged behind that of the dilatational strain, due to the delay of groundwater flow to the well with respect to the tidal strain. Following each earthquake, however, the phase of water-level fluctuations increased and became the same as that of the dilatational strain. In addition, we show that the predicted change in water level from the co-seismic dilatational strain has the same sign, amplitude and time history as those of the observed coseismic change in water level. The similarity between the simulated and observed coseismic water-level change, together with the similarity in phase between the tidal response of water level and that of dilatational strain after the earthquake, suggest that the dominant mechanism for the coseismic dilatational strain in the Fuxin well is the co-seismic change in pore pressure in the vicinity of the well.

  5. The impact of capillary dilation on the distribution of red blood cells in artificial networks.

    PubMed

    Schmid, Franca; Reichold, Johannes; Weber, Bruno; Jenny, Patrick

    2015-04-01

    Recent studies suggest that pericytes around capillaries are contractile and able to alter the diameter of capillaries. To investigate the effects of capillary dilation on network dynamics, we performed simulations in artificial capillary networks of different sizes and complexities. The unequal partition of hematocrit at diverging bifurcations was modeled by assuming that each red blood cell (RBC) enters the branch with the faster instantaneous flow. Network simulations with and without RBCs were performed to investigate the effect of local dilations. The results showed that the increase in flow rate due to capillary dilation was less when the effects of RBCs are included. For bifurcations with sufficient RBCs in the parent vessel and nearly equal flows in the branches, the flow rate in the dilated branch did not increase. Instead, a self-regulation of flow was observed due to accumulation of RBCs in the dilated capillary. A parametric study was performed to examine the dependence on initial capillary diameter, dilation factor, and tube hematocrit. Furthermore, the conditions needed for an efficient self-regulation mechanism are discussed. The results support the hypothesis that RBCs play a significant role for the fluid dynamics in capillary networks and that it is crucial to consider the blood flow rate and the distribution of RBCs to understand the supply of oxygen in the vasculature. Furthermore, our results suggest that capillary dilation/constriction offers the potential of being an efficient mechanism to alter the distribution of RBCs locally and hence could be important for the local regulation of oxygen delivery. PMID:25617356

  6. Large Diameter Limbs for Dilated Common Iliac Arteries in Endovascular Aneurysm Repair. Is It Safe?

    SciTech Connect

    Malagari, Katerina Brountzos, Elias; Gougoulakis, Alexandros; Papathanasiou, Matilda; Alexopoulou, Efthymia; Mastorakou, Renata; Kelekis, Dimitris

    2004-09-15

    In this prospective study we examined whether dilated common iliac arteries (CIAs) can provide a safe distal seal in endovascular aneurysm repair (EVAR) with the use of bifurcated stent grafts with large diameter limbs. Sixteen patients with 26 dilated CIAs with a diameter of {>=}6 mm who were offered EVAR using stent grafts with large diameter limbs were included in the study (Group A). Forty-two patients who also underwent EVAR without iliac dilatation, matched for age, sex and surgical risk were used for comparison (controls-Group B). In group A mean CIA diameter was 18.2 mm (16-28) and mean abdominal aortic aneurysm (AAA) diameter was 6.87 {+-} 1.05 cm; mean age was 77.2 {+-} 4.8 yrs (67-81). Mean follow-up was 33.6 months (2.8 yrs). CIA diameter changes and development of endoleaks were assessed by CT angiography (CTA). Overall iliac dilatation was present in 16/58 of our patients (27.6%). In 10 patients dilatation was bilateral (17.3%). Partial or complete flow to the internal iliac artery (IIA) territories was preserved in all patients post-EVAR. On follow-up, stable caliber of the dilated CIAs was observed in 21 patients (84%), enlargement of 1mm in 3 (16%), and failure of the distal attachment in 1 (6.2%). Compared to the control group there was no statistical significance in the incidence of complications. Dilated common iliac arteries provide a safe distal seal in patients who have undergone EVAR, thus obviating the need for additional endovascular procedures and sparing flow in the IIA vascular bed.

  7. Potential genetic predisposition for anthracycline-associated cardiomyopathy in families with dilated cardiomyopathy

    PubMed Central

    Wasielewski, Marijke; van Spaendonck-Zwarts, Karin Y; Westerink, Nico-Derk L; Jongbloed, Jan D H; Postma, Aleida; Gietema, Jourik A; van Tintelen, J Peter; van den Berg, Maarten P

    2014-01-01

    Objective Anthracyclines are successfully used in cancer treatment, but their use is limited by their cardiotoxic side effects. Several risk factors for anthracycline-associated cardiomyopathy (AACM) are known, yet the occurrence of AACM in the absence of these known risk factors suggests that other factors must play a role. The purpose of this study was to evaluate whether a genetic predisposition for dilated cardiomyopathy (DCM) could be a potential risk factor for AACM. Methods A hospital-based registry of 162 DCM families and two hospital-based registries of patients with cancer treated with systemic cancer therapy (n>6000) were reviewed focusing on AACM. Selected patients with AACM/DCM families with possible AACM (n=21) were analysed for mutations in cardiomyopathy-associated genes and presymptomatic cardiological evaluation of first-degree relatives was performed. Results We identified five DCM families with AACM and one patient with AACM with a family member with a possible early sign of mild DCM. Pathogenic MYH7 mutations were identified in two of these six families. The MYH7 c.1633G>A (p.Asp545Asn) and c.2863G>A (p.Asp955Asn) mutations (one double mutant allele) were identified in a DCM family with AACM. The MYH7 c.4125T>A (p.Tyr1375X) mutation was identified in one patient with AACM. Conclusions This study further extends the hypothesis that a genetic predisposition to DCM could be a potential risk factor for AACM. PMID:25332820

  8. Effect of beta-blockers on insulin resistance in patients with dilated cardiomyopathy.

    PubMed

    Hara, Yuji; Hamada, Mareomi; Shigematsu, Yuji; Ohtsuka, Tomoaki; Ogimoto, Akiyoshi; Higaki, Jitsuo

    2003-08-01

    The aim of this study was to evaluate the effect of beta-blockers on insulin resistance in patients with dilated cardiomyopathy (DCM). A secondary aim was to determine the effect of this treatment on plasma concentrations of tumor necrosis factor-alpha (TNF-alpha) and to investigate the relationships between this adipocytokine and insulin resistance. Insulin resistance determined using the Homeostatic Model Assessment (HOMA), echocardiographic measurements and analysis of plasma TNF-alpha concentration were carried out in 47 patients with DCM without diabetes mellitus before and after 6 months of beta-blocker therapy. A reduction in left ventricular dimensions and an associated increase in ejection fraction occurred with beta-blocker. The treatment resulted in a significant decrease in insulin resistance (HOMA index: Baseline, 2.73+/-3.36 vs, Month 6, 1.58+/-1.33, p=0.0347). Beta-blockade was also associated with a decrease in plasma TNF-alpha concentration although no significant relationship between this change and the improvement in insulin resistance was observed. Beta-blocker therapy in patients with DCM improved not only cardiac function, but also insulin resistance. The mechanism of the change in insulin function remains unclear, but may be related to improvements in left ventricular function or an attenuation of the inhibitory effect of reduction in TNF-alpha on insulin signaling.

  9. Dilated contour extraction and component labeling algorithm for object vector representation

    NASA Astrophysics Data System (ADS)

    Skourikhine, Alexei N.

    2005-08-01

    Object boundary extraction from binary images is important for many applications, e.g., image vectorization, automatic interpretation of images containing segmentation results, printed and handwritten documents and drawings, maps, and AutoCAD drawings. Efficient and reliable contour extraction is also important for pattern recognition due to its impact on shape-based object characterization and recognition. The presented contour tracing and component labeling algorithm produces dilated (sub-pixel) contours associated with corresponding regions. The algorithm has the following features: (1) it always produces non-intersecting, non-degenerate contours, including the case of one-pixel wide objects; (2) it associates the outer and inner (i.e., around hole) contours with the corresponding regions during the process of contour tracing in a single pass over the image; (3) it maintains desired connectivity of object regions as specified by 8-neighbor or 4-neighbor connectivity of adjacent pixels; (4) it avoids degenerate regions in both background and foreground; (5) it allows an easy augmentation that will provide information about the containment relations among regions; (6) it has a time complexity that is dominantly linear in the number of contour points. This early component labeling (contour-region association) enables subsequent efficient object-based processing of the image information.

  10. [Dilated cardiomyopathy: a dynamic disease - clinical course, reverse remodeling and prognostic stratification].

    PubMed

    Merlo, Marco; Gigli, Marta; Poli, Stefano; Stolfo, Davide; Brun, Francesca; Lardieri, Gerardina; Pinamonti, Bruno; Zecchin, Massimo; Pivetta, Alberto; Vitrella, Giancarlo; Di Lenarda, Andrea; Sinagra, Gianfranco

    2016-01-01

    Dilated cardiomyopathy (DCM) is a relatively rare primary heart muscle disease with genetic or post-inflammatory etiology. In the last decade, the incidence and prevalence of the disease have significantly increased as a consequence of an earlier diagnosis supported by extensive familial screening programs and by the improvement in diagnostic techniques. Moreover, current therapeutic strategies have deeply modified the prognosis of DCM with a dramatic reduction in mortality. A significant number of patients with DCM present an impressive response to pharmacological and non-pharmacological therapy in terms of left ventricular reverse remodeling (reduction in ventricular size with improvement of systolic function), which confers a more favorable prognosis in the long term. However, the identification of patients with an increased likelihood of improvement after therapeutic optimization remains a challenging issue; in particular the assessment of arrhythmic risk carries important implications. Finally, the long-term follow-up of patients showing a significant left ventricular functional recovery under optimal treatment is still poorly known. Hence, the aim of the present review is to provide an insight into the clinical evolution/long-term follow-up of DCM, which should be actually considered a dynamic process rather than a static and chronic disease. Left ventricular reverse remodeling should be considered a key therapeutic goal, mostly associated with a long-standing recovery, but cannot be considered the expression of permanent "healing", confirming the need for a systematic and careful follow-up over time in this setting.

  11. Angiopoietin-4 increases permeability of blood vessels and promotes lymphatic dilation.

    PubMed

    Kesler, Cristina T; Pereira, Ethel R; Cui, Cheryl H; Nelson, Gregory M; Masuck, David J; Baish, James W; Padera, Timothy P

    2015-09-01

    The angiopoietin (Ang) ligands are potential therapeutic targets for lymphatic related diseases, which include lymphedema and cancer. Ang-1 and Ang-2 functions are established, but those of Ang-4 are poorly understood. We used intravital fluorescence microscopy to characterize Ang-4 actions on T241 murine fibrosarcoma-associated vessels in mice. The diameters of lymphatic vessels draining Ang-4- or VEGF-C (positive control)-expressing tumors increased to 123 and 135 μm, respectively, and parental, mock-transduced (negative controls) and tumors expressing Ang-1 or Ang-2 remained at baseline (∼60 μm). Ang-4 decreased human dermal lymphatic endothelial cell (LEC) monolayer permeability by 27% while increasing human dermal blood endothelial cell (BEC) monolayer permeability by 200%. In vivo, Ang-4 stimulated a 4.5-fold increase in tumor-associated blood vessel permeability compared with control when measured using intravital quantitative multiphoton microscopy. Ang-4 activated receptor signaling in both LECs and BECs, evidenced by tyrosine kinase with Ig and endothelial growth factor homology domains-2 (TIE2) receptor, protein kinase B, and Erk1,2 phosphorylation detectable by immunoblotting. These data suggest that Ang-4 actions are mediated through cell-type-specific networks and that lymphatic vessel dilation occurs secondarily to increased vascular leakage. Ang-4 also promoted survival of LECs. Thus, blocking Ang-4 may prune the draining lymphatic vasculature and decrease interstitial fluid pressure (IFP) by reducing vascular permeability.

  12. Deformation bands evolving from dilation to cementation bands in a hydrocarbon reservoir (Vienna Basin, Austria)

    PubMed Central

    Exner, Ulrike; Kaiser, Jasmin; Gier, Susanne

    2013-01-01

    In this study we analyzed five core samples from a hydrocarbon reservoir, the Matzen Field in the Vienna Basin (Austria). Deformation bands occur as single bands or as strands of several bands. In contrast to most published examples of deformation bands in terrigeneous sandstones, the reduction of porosity is predominantly caused by the precipitation of Fe-rich dolomite cement within the bands, and only subordinately by cataclasis of detrital grains. The chemical composition of this dolomite cement (10–12 wt% FeO) differs from detrital dolomite grains in the host rock (<2 wt% FeO). This observation in combination with stable isotope data suggests that the cement is not derived from the detrital grains, but precipitated from a fluid from an external, non-meteoric source. After an initial increase of porosity by dilation, disaggregation and fragmentation of detrital grains, a Fe-rich carbonate fluid crystallized within the bands, thereby reducing the porosity relative to the host sediment. The retention of pyrite cement by these cementation bands as well as the different degree of oil staining on either side of the bands demonstrate that these cementation bands act as effective barriers to the migration of fluids and should be considered in reservoir models. PMID:26321782

  13. Afterload reduction: a comparison of captopril and nifedipine in dilated cardiomyopathy.

    PubMed Central

    Agostoni, P G; De Cesare, N; Doria, E; Polese, A; Tamborini, G; Guazzi, M D

    1986-01-01

    Nifedipine and captopril are potent vasodilators and may be expected to help left ventricular failure by reducing afterload. Nifedipine (20 mg three times a day) and captopril (50 mg three times a day) were added to an optimal regimen of digitalis and diuretics in a double blind crossover trial in 18 cases of dilated cardiomyopathy. New York Heart Association functional class rating symptoms and exercise tolerance times improved on captopril but not on nifedipine. The reduction in pulmonary capillary wedge pressure and the increase of cardiac output on captopril indicated that the augmented functional capacity may have resulted in part from an improved performance of the left ventricle. Although there were comparable decreases in systemic vascular resistance and presumably in impedence to ejection by the left ventricle on both drugs, the dimensions of the ventricular cavity were found to be reduced by captopril and augmented by nifedipine, and only captopril reduced the afterload (wall stress). In addition, the force-length relation (between left ventricular end systolic stress and end systolic diameter) was shifted to the left of baseline by captopril and to the right by nifedipine, suggesting that muscle contractility was reduced by nifedipine and not by captopril. These results suggest that nifedipine and captopril have different effects on afterload and contractility and these may account for the different effects of these drugs on the performance of the heart and clinical responses. PMID:3516187

  14. the contribution of south Africans to the subject of dilated cardiomyopathy

    PubMed Central

    Watkins, David A; Mayosi, Bongani M

    2009-01-01

    Summary Background Dilated cardiomyopathy (DCM) is a heart muscle disease that is endemic in Africa. Over the past 50 years, South African investigators have made significant contributions to scientific elucidation of the condition. The objective of this review was to summarise their research on the subject of DCM. Methods and results We searched PubMed for articles originating from South Africa and focusing on DCM or the related condition, peripartum cardiomyopathy (PCM). Reference lists and prominent South African researchers on DCM were also consulted. The prevalence of DCM is comparable in magnitude to that of other endemic heart conditions such as hypertension and rheumatic heart disease, although by comparison, DCM may cause disproportionate morbidity from heart failure. In the African context, malnutrition, excessive alcohol intake, prior myocarditis and genetic make-up have been proposed as aetiologies, and some or all of these factors may play an interrelated role in individual disease expression. The pathogenesis of DCM is partially due to the mechanical effects of fibrosis, and the immune response to myocardial damage likely affects disease progression. Small trials of pentoxifylline plus conventional therapy have demonstrated a trend towards reduced mortality from heart failure. Conclusions Despite half a century of noteworthy research, the pathogenic mechanisms of DCM are still incompletely understood. South Africans have, however, played and should continue to play a critical role in advancing research on DCM. PMID:19287809

  15. Mechanisms of flow and ACh-induced dilation in rat soleus arterioles are altered by hindlimb unweighting

    NASA Technical Reports Server (NTRS)

    Schrage, William G.; Woodman, Christopher R.; Laughlin, M. Harold

    2002-01-01

    The purpose of this study was to test the hypothesis that endothelium-dependent dilation (flow-induced dilation and ACh-induced dilation) in rat soleus muscle arterioles is impaired by hindlimb unweighting (HLU). Male Sprague-Dawley rats (approximately 300 g) were exposed to HLU or weight-bearing control (Con) conditions for 14 days. Soleus first-order (1A) and second-order (2A) arterioles were isolated, cannulated, and exposed to step increases in luminal flow at constant pressure. Flow-induced dilation was not impaired by HLU in 1A or 2A arterioles. The cyclooxygenase inhibitor indomethacin (Indo; 50 microM) did not alter flow-induced dilation in 1As or 2As. Inhibition of nitric oxide synthase (NOS) with N(omega)-nitro-L-arginine (L-NNA; 300 microM) reduced flow-induced dilation by 65-70% in Con and HLU 1As. In contrast, L-NNA abolished flow-induced dilation in 2As from Con rats but had no effect in HLU 2As. Combined treatment with L-NNA + Indo reduced tone in 1As and 2As from Con rats, but flow-induced dilation in the presence of L-NNA + Indo was not different from responses without inhibitors in either Con or HLU 1As or 2As. HLU also did not impair ACh-induced dilation (10(-9)-10(-4) M) in soleus 2As. L-NNA reduced ACh-induced dilation by approximately 40% in Con 2As but abolished dilation in HLU 2As. Indo did not alter ACh-induced dilation in Con or HLU 2As, whereas combined treatment with L-NNA + Indo abolished ACh-induced dilation in 2As from both groups. We conclude that flow-induced dilation (1As and 2As) was preserved after 2 wk HLU, but HLU decreased the contribution of NOS in mediating flow-induced dilation and increased the contribution of a NOS- and cyclooxygenase-independent mechanism (possibly endothelium-derived hyperpolarizing factor). In soleus 2As, ACh-induced dilation was preserved after 2-wk HLU but the contribution of NOS in mediating ACh-induced dilation was increased.

  16. Adherence to Vaginal Dilation Following High Dose Rate Brachytherapy for Endometrial Cancer

    SciTech Connect

    Friedman, Lois C.; Abdallah, Rita; Schluchter, Mark; Panneerselvam, Ashok; Kunos, Charles A.

    2011-07-01

    Purpose: We report demographic, clinical, and psychosocial factors associated with adherence to vaginal dilation and describe the sexual and marital or nonmarital dyadic functioning of women following high dose rate (HDR) brachytherapy for endometrial cancer. Methods and Materials: We retrospectively evaluated women aged 18 years or older in whom early-stage endometrial (IAgr3-IIB) cancers were treated by HDR intravaginal brachytherapy within the past 3.5 years. Women with or without a sexual partner were eligible. Patients completed questionnaires by mail or by telephone assessing demographic and clinical variables, adherence to vaginal dilation, dyadic satisfaction, sexual functioning, and health beliefs. Results: Seventy-eight of 89 (88%) eligible women with early-stage endometrial cancer treated with HDR brachytherapy completed questionnaires. Only 33% of patients were adherers, based on reporting having used a dilator more than two times per week in the first month following radiation. Nonadherers who reported a perceived change in vaginal dimension following radiation reported that their vaginas were subjectively smaller after brachytherapy (p = 0.013). Adherers reported more worry about their sex lives or lack thereof than nonadherers (p = 0.047). Patients reported considerable sexual dysfunction following completion of HDR brachytherapy. Conclusions: Adherence to recommendations for vaginal dilator use following HDR brachytherapy for endometrial cancer is poor. Interventions designed to educate women about dilator use benefit may increase adherence. Although sexual functioning was compromised, it is likely that this existed before having cancer for many women in our study.

  17. Effects of grain shape on packing and dilatancy of sheared granular materials.

    PubMed

    Wegner, Sandra; Stannarius, Ralf; Boese, Axel; Rose, Georg; Szabó, Balázs; Somfai, Ellák; Börzsönyi, Tamás

    2014-07-28

    A granular material exposed to shear shows a variety of unique phenomena: Reynolds dilatancy, positional order and orientational order effects may compete in the shear zone. We study granular packing consisting of macroscopic prolate, oblate and spherical grains and compare their behaviour. X-ray tomography is used to determine the particle positions and orientations in a cylindrical split bottom shear cell. Packing densities and the arrangements of individual particles in the shear zone are evaluated. For anisometric particles, we observe the competition of two opposite effects. On the one hand, the sheared granules are dilated, on the other hand the particles reorient and align with respect to the streamlines. Even though aligned cylinders in principle may achieve higher packing densities, this alignment compensates for the effect of dilatancy only partially. The complex rearrangements lead to a depression of the surface above the well oriented region while neighbouring parts still show the effect of dilation in the form of heaps. For grains with isotropic shapes, the surface remains rather flat. Perfect monodisperse spheres crystallize in the shear zone, whereby positional order partially overcompensates dilatancy effects. However, even slight deviations from the ideal monodisperse sphere shape inhibit crystallization. PMID:24911156

  18. Elastic fields due to centers of dilatation and thermal inhomogeneities in plane-layered solids

    NASA Astrophysics Data System (ADS)

    Yu, H. Y.; Sanday, S. C.

    1993-02-01

    A N IMAGE METHOD for obtaining the solution for a center of dilatation in a three-layer elastic solid with planar interfaces is presented. The three-layered elastic solid consists of an elastic slab sandwiched between two semi-infinite elastic solids. The three elastic solids are perfectly bonded together at the two planar interfaces. The solution is given in terms of Galerkin vectors which are in terms of an infinite series of the Newtonian potential function of a mass point at the center of dilatation, its mirror images and their derivatives. As an application, the solution for the center of dilatation is used to obtain the elastic solution due to thermal inhomogeneities. The thermoelastic solution is obtained by a method which is based on the integration of properly weighted centers of dilatation over the volume occupied by the inhomogeneity. The potential functions for the problem solved are the harmonic potential functions of attracting matter filling the volume of the thermal inhomogeneity and its mirror images. The solution for the thermal elastic stresses due to an expanding (or contracting) thermal inhomogeneity (inclusion) of any shape embedded in one of the solids is given as an example. Numerical results for a spherical inclusion with pure dilatation eigenstrain are also presented and discussed.

  19. Effects of grain shape on packing and dilatancy of sheared granular materials.

    PubMed

    Wegner, Sandra; Stannarius, Ralf; Boese, Axel; Rose, Georg; Szabó, Balázs; Somfai, Ellák; Börzsönyi, Tamás

    2014-07-28

    A granular material exposed to shear shows a variety of unique phenomena: Reynolds dilatancy, positional order and orientational order effects may compete in the shear zone. We study granular packing consisting of macroscopic prolate, oblate and spherical grains and compare their behaviour. X-ray tomography is used to determine the particle positions and orientations in a cylindrical split bottom shear cell. Packing densities and the arrangements of individual particles in the shear zone are evaluated. For anisometric particles, we observe the competition of two opposite effects. On the one hand, the sheared granules are dilated, on the other hand the particles reorient and align with respect to the streamlines. Even though aligned cylinders in principle may achieve higher packing densities, this alignment compensates for the effect of dilatancy only partially. The complex rearrangements lead to a depression of the surface above the well oriented region while neighbouring parts still show the effect of dilation in the form of heaps. For grains with isotropic shapes, the surface remains rather flat. Perfect monodisperse spheres crystallize in the shear zone, whereby positional order partially overcompensates dilatancy effects. However, even slight deviations from the ideal monodisperse sphere shape inhibit crystallization.

  20. Recurrent gastric dilatation and intestinal dysmotility possibly resulting from autonomic neuropathy in a Great Dane.

    PubMed

    Spoo, Joseph W; Shelton, G Diane

    2014-01-01

    A 5 yr old female spayed Great Dane was presented for recurrent episodes of gastric dilatation, intestinal dysmotility, and one episode of gastric rupture. Numerous hematologic, radiographic, and endocrine diagnostic tests were performed with no identifiable underlying cause. Many risk factors have been identified for gastric dilatation and most were present in this Great Dane. A number of symptomatic treatments, aimed primarily at altering the gastrointestinal tract flora and motility were tried, but failed to influence the clinical course of the disease. The dog continued to worsen, experienced more frequent episodes of gastric dilatation, and developed generalized muscle atrophy. Biopsies were collected from the biceps femoris and triceps brachii muscles. A pattern of denervation atrophy was evident in both muscles, consistent with polyneuropathy. The owners elected humane euthanasia and a necropsy was performed. A striking finding at necropsy was severe loss of myelinated fibers with extensive endoneurial fibrosis in the vagus nerve, consistent with an autonomic neuropathy. Autonomic neuropathy is a previously unexplored cause of gastric dilatation and intestinal dysmotility in dogs. These findings should open new directions for exploring pathogenic mechanisms for gastric dilatation in this species.

  1. Paediatric dilated cardiomyopathy: clinical profile and outcome. The experience of a tertiary centre for paediatric cardiology.

    PubMed

    Miranda, Joana O; Costa, Liane; Rodrigues, Esmeralda; Teles, Elisa L; Baptista, Maria J; Areias, José C

    2015-02-01

    Dilated cardiomyopathy is the most common form of cardiomyopathy in the paediatric population and an important cause of heart transplantation in children. The clinical profile and course of dilated cardiomyopathy in children have been poorly characterised. A retrospective review of 61 patients (37 female; 24 male) diagnosed with dilated cardiomyopathy from January, 2005 to June, 2012 at a single institution was performed. The median age at diagnosis was 15 months. Heart failure was present in 83.6% of patients and 44.3% required intensive care. The most prevalent causes were idiopathic (47.5%), viral myocarditis (18.0%) and inherited metabolic diseases (11.5%). In viral myocarditis, Parvovirus B19 was the most common identified agent, in concurrence with the increasing incidence documented recently. Inherited metabolic diseases were responsible for 11.5% of dilated cardiomyopathy cases compared with the 4-6% described in the literature, which reinforces the importance of considering this aetiology in differential diagnosis of paediatric dilated cardiomyopathy. The overall mortality rate was 16.1% and five patients underwent heart transplantation. In our series, age at diagnosis and aetiology were the most important prognosis factors. We report no mortality in the five patients who underwent heart transplantation, after 2 years of follow-up.

  2. Eosinophilic esophagitis: dilate or medicate? A cost analysis model of the choice of initial therapy.

    PubMed

    Kavitt, R T; Penson, D F; Vaezi, M F

    2014-07-01

    Eosinophilic esophagitis (EoE) is an increasingly recognized clinical entity. The optimal initial treatment strategy in adults with EoE remains controversial. The aim of this study was to employ a decision analysis model to determine the less costly option between the two most commonly employed treatment strategies in EoE. We constructed a model for an index case of a patient with biopsy-proven EoE who continues to be symptomatic despite proton-pump inhibitor therapy. The following treatment strategies were included: (i) swallowed fluticasone inhaler (followed by esophagogastroduodenoscopy [EGD] with dilation if ineffective); and (ii) EGD with dilation (followed by swallowed fluticasone inhaler if ineffective). The time horizon was 1 year. The model focused on cost analysis of initial treatment strategies. The perspective of the healthcare payer was used. Sensitivity analyses were performed to assess the robustness of the model. For every patient whose symptoms improved or resolved with the strategy of fluticasone first followed by EGD, if necessary, it cost an average of $1078. Similarly, it cost an average of $1171 per patient if EGD with dilation was employed first. Sensitivity analyses indicated that initial treatment with fluticasone was the less costly strategy to improve dysphagia symptoms as long as the effectiveness of fluticasone remains at or above 0.62. Swallowed fluticasone inhaler (followed by EGD with dilation if necessary) is the more economical initial strategy when compared with EGD with dilation first.

  3. Treatment of dilated pores with 1410-nm fractional erbium-doped fiber laser.

    PubMed

    Suh, Dong-Hye; Chang, Ka-Yeun; Lee, Sang-Jun; Song, Kye-Yong; Choi, Jeong Hwee; Shin, Min Kyung; Jeong, Ki-Heon

    2015-04-01

    Dilated pores can be an early sign of skin aging and are a significant cosmetic concern. The 1410-nm wavelength is optimal for superficial dermal treatments up to 650 μm deep. The aim of the present study was to evaluate the clinical effectiveness and safety of the fractional erbium-doped fiber 1410-nm laser in the treatment of dilated pores. Fifteen patients with dilated facial pores underwent three laser treatments at 3-week intervals. Posttreatment skin responses and side effects were assessed at treatment and follow-up visits by study physicians. Clinical effectiveness of treatment was assessed by both study physicians and patients 3 months after the final laser treatment using a quartile grading scale. Histological examination was performed using biopsy samples taken at baseline (pretreatment) and 3 months after the last treatment. This study showed that greater than 51 % improvement in dilated pores was demonstrated in 14 of 15 patients after three sessions of laser treatments. Improvements in skin texture, tone, and smoothness were reported in all patients. Treatment was well tolerated in all patients, with no unanticipated side effects. This study demonstrates that the 1410-nm fractional erbium fiber laser is effective and safe for treatment of dilated facial pores in Fitzpatrick skin types III-IV.

  4. Cervical dilatation in late first trimester termination by prostaglandin, hylase and isogel.

    PubMed

    Mandlekar, A V; Ganguli, A C; Krishna, U R; Purandare, V N

    1981-04-01

    Pre-operative dilatation of the cervix was attempted in 223 cases prior to vacuum aspiration in patients seeking late first trimester termination beyond ten weeks. 15 Me PGF2a was used in the form of vaginal suppositories, intramuscular and intracervical injections. Dilatation of cervix of 10 mm or more was achieved within 4 hours in 86% cases with intra-cervical injections. Gastro-intestinal disturbances caused by intra-muscular injections could be avoided by intra-cervical injections, as the amount of prostaglandin required was only 100 ugm, but the success rate was significantly lower. The success with multiple dose suppositories was 80%. There was no significant difference in the success with 1.5 mgm or 1.0 mgm dosage, but the side effects were significantly higher with 1.5 mgm suppositories. Intra-cervical Hylase did not dilate the cervix but successfully softened it within 5 minutes to make metallic dilatation simple. The hygroscopic Isogel tents achieved dilatation of 10 mm or more in 73% of the patients in 12 hours. The tents as well as intra-cervical prostaglandin injection had the disadvantage of requiring an additional theatre procedure prior to suction curettage.

  5. An effective group psychoeducational intervention for improving compliance with vaginal dilation: A randomized controlled trial

    SciTech Connect

    Jeffries, Sherryl A.; Robinson, John W. . E-mail: johnrobi@cancerboard.ab.ca; Craighead, Peter S.; Keats, Melanie R.

    2006-06-01

    Purpose: Although vaginal dilation is often recommended to minimize or prevent vaginal scarring after pelvic radiotherapy, compliance with this recommendation has historically been very low. Therefore, effective intervention strategies are needed to enhance compliance with vaginal dilation after radiotherapy for gynecologic cancer. Methods and Materials: This study was a randomized controlled clinical trial of a psychoeducational intervention specifically designed to increase compliance with vaginal dilation. The information-motivation-behavioral skills model of enhancing compliance with behavioral change was the basis for the intervention design. Forty-two sexually active women, 21 to 65 years of age, diagnosed with Stages Ic-III cervical or endometrial cancer, who received pelvic radiotherapy, were randomized to either the experimental psychoeducational group or the information-only control group. Assessment via questionnaire occurred before treatment and at 6-week, 6-month, 12-month, 18-month, and 24-month follow-up. Assessment via interview also occurred at 6-month, 12-month, 18-month, and 24-month follow-up. Results: The psychoeducational intervention was successful in increasing compliance with vaginal dilation. Conclusions: This study is the first randomized controlled study to demonstrate the effectiveness of an intervention in increasing compliance with the use of vaginal dilators.

  6. Relativity on a Spreadsheet.

    ERIC Educational Resources Information Center

    Carson, S. R.

    1998-01-01

    Presents a method for using spreadsheets to model special relativistic phenomena based on the connection between electric and magnetic fields in special relativity. Uses the time dilation equation to carry out transformations between reference frames that show the connection between the fields quantitatively. (DDR)

  7. A comparison among four tract dilation methods of percutaneous nephrolithotomy: a systematic review and meta-analysis.

    PubMed

    Dehong, Cao; Liangren, Liu; Huawei, Liu; Qiang, Wei

    2013-11-01

    The purpose of this study was to evaluate the efficacy and safety of the Amplatz dilation (AD), metal telescopic dilation (MTD), balloon dilation (BD), and one-shot dilation (OSD) methods for tract dilation during percutaneous nephrolithotomy (PCNL). Relevant eligible studies were identified using three electronic databases (Medline, EMBASE, and Cochrane CENTRAL). Database acquisition and quality evaluation were independently performed by two reviewers. Efficacy (stone-free rate, surgical duration, and tract dilatation fluoroscopy time) and safety (transfusion rate and hemoglobin decrease) were evaluated using Review Manager 5.2. Four randomized controlled trials and eight clinical controlled trials involving 6,820 patients met the inclusion criteria. The pooled result from a meta-analysis showed statistically significant differences in tract dilatation fluoroscopy time and hemoglobin decrease between the OSD and MTD groups, which showed comparable stone-free and transfusion rates. Significant differences in transfusion rate were found between the BD and MTD groups. Among patients without previous open renal surgery, those who underwent BD exhibited a lower blood transfusion rate and a shorter surgical duration compared with those who underwent AD. The OSD technique is safer and more efficient than the MTD technique for tract dilation during PCNL, particularly in patients with previous open renal surgery, resulting in a shorter tract dilatation fluoroscopy time and a lesser decrease in hemoglobin. The efficacy and safety of BD are better than AD in patients without previous open renal surgery. The OSD technique should be considered for most patients who undergo PCNL therapy.

  8. Non-Surgical Management of Critically Compromised Airway Due to Dilatation of Interposed Colon

    PubMed Central

    Min, Jinsoo

    2016-01-01

    We present a rare case of critically compromised airway secondary to a massively dilated sequestered colon conduit after several revision surgeries. A 71-year-old male patient had several operations after the diagnosis of gastric cancer. After initial treatment of pneumonia in the pulmonology department, he was transferred to the surgery department for feeding jejunostomy because of recurrent aspiration. However, he had respiratory failure requiring mechanical ventilation. The chest computed tomography (CT) scan showed pneumonic consolidation at both lower lungs and massive dilatation of the substernal interposed colon compressing the trachea. The dilated interposed colon was originated from the right colon, which was sequestered after the recent esophageal reconstruction with left colon interposition resulting blind pouch at both ends. It was treated with CT-guided pigtail catheter drainage via right supraclavicular route, which was left in place for 2 weeks, and then removed. The patient remained well clinically, and was discharged home. PMID:27066087

  9. Non-Surgical Management of Critically Compromised Airway Due to Dilatation of Interposed Colon.

    PubMed

    Min, Jinsoo; Cho, Young-Jae

    2016-04-01

    We present a rare case of critically compromised airway secondary to a massively dilated sequestered colon conduit after several revision surgeries. A 71-year-old male patient had several operations after the diagnosis of gastric cancer. After initial treatment of pneumonia in the pulmonology department, he was transferred to the surgery department for feeding jejunostomy because of recurrent aspiration. However, he had respiratory failure requiring mechanical ventilation. The chest computed tomography (CT) scan showed pneumonic consolidation at both lower lungs and massive dilatation of the substernal interposed colon compressing the trachea. The dilated interposed colon was originated from the right colon, which was sequestered after the recent esophageal reconstruction with left colon interposition resulting blind pouch at both ends. It was treated with CT-guided pigtail catheter drainage via right supraclavicular route, which was left in place for 2 weeks, and then removed. The patient remained well clinically, and was discharged home. PMID:27066087

  10. Mimicking within Euclidean space a cosmological time dilation of gamma-ray burst durations

    NASA Technical Reports Server (NTRS)

    Brainerd, J. J.

    1994-01-01

    If gamma-ray burst sources are cosmological in origin, then the time dilation at large z can correlate a burst's duration with its peak flux. Detection of this effect is thought by many to be strong evidence for a cosmological burst origin. In this Letter I show that an apparent time distortion--either a dilation or contraction--is generally expected for an ensemble of bursts that is spatially limited within Euclidean space. The appearance of this effect is correlated with the falling away of the log N-log P curve from a -3/2 slope line. An example of this effect is provided by the relativistic bulk motion model, which produces a strong time dilation when spatially limited in Euclidean space. As a consequence, envidence that weak bursts have longer durations than strong bursts is not evidence of a cosmological burst origin.

  11. COSMOLOGICAL TIME DILATION IN DURATIONS OF SWIFT LONG GAMMA-RAY BURSTS

    SciTech Connect

    Zhang, Fu-Wen; Fan, Yi-Zhong; Wei, Da-Ming; Shao, Lang

    2013-11-20

    Cosmological time dilation is a fundamental phenomenon in an expanding universe, which stresses that both the duration and wavelength of the emitted light from a distant object at the redshift z will be dilated by a factor of 1 + z at the observer. By using a sample of 139 Swift long gamma-ray bursts with known redshift (z ≤ 8.2), we measure the observed duration (T {sub 90}) in the observed energy range between 140/(1 + z) keV and 350/(1 + z) keV, corresponding to a fixed energy range of 140-350 keV in the rest frame. We obtain a significant correlation between the duration and the factor 1 + z, i.e., T {sub 90} = 10.5(1 + z){sup 0.94} {sup ±} {sup 0.26}, which is consistent with that expected from the cosmological time dilation effect.

  12. [Recurrent excessive dilatation of the efferent urinary tract in pregnancy. Case report].

    PubMed

    Kindt, J; Retzke, U; Herrmann, K

    1988-01-01

    Case report on a patient with an extensive dilatation of renal pelvis and ureter during the first and the following two pregnancies. Operative drainage was performed of renal pelvis on both sides in the 24th and 28th week of the first pregnancy. The second pregnancy ended with spontaneous abortion in the 27th week of pregnancy. Percutaneous punction nephrostomy with successful course of the third pregnancy. Drainage of renal pelvis by punction nephrostomy is indicated in case of co-existence between dilatation of renal pelvis and severe illness and destruction renal parenchyma and of septic pyelonephritis in pregnancy. This procedure should also be done in case of a solitary kidney and excessive dilatation of the renal pelvis. An operative approach is recommended in renal abscess.

  13. Dilated iris vasculature in the setting of the neonatal hypoxic encephelopathy.

    PubMed

    Gorovoy, Ian R; Vaccari, Jordan C

    2015-07-01

    The differential diagnosis of dilated iris vasculature in a neonate includes retinopathy of prematurity with anterior segment plus disease, persistent fetal vasculature, intrauterine cocaine exposure, maternal diabetes, and other pathologies associated with iris neovascularization and ischemia seen in adult populations, such as central retinal vein occlusions, ocular ischemic syndrome, and chronic retinal detachment. We present neonatal hypoxic ischemic encephalopathy as a new etiology of dilated iris vasculature in a male baby who suffered a large in-utero brain vasculature insult three weeks prior to delivery but with normal fundi, no risk factors for retinopathy of prematurity (normal birth weight, and gestational age), and no other explanatory etiologies. The mechanism of the dilated iris vasculature is likely also ischemic and therefore its presence likely portends a poor prognosis. We recommend that the neonatologist evaluate for this sign for this reason and consult ophthalmology to ensure its correct etiology.

  14. Dilation and Hypertrophy: A Cell-Based Continuum Mechanics Approach Towards Ventricular Growth and Remodeling

    NASA Astrophysics Data System (ADS)

    Ulerich, J.; Göktepe, S.; Kuhl, E.

    This manuscript presents a continuum approach towards cardiac growth and remodeling that is capable to predict chronic maladaptation of the heart in response to changes in mechanical loading. It is based on the multiplicative decomposition of the deformation gradient into and elastic and a growth part. Motivated by morphological changes in cardiomyocyte geometry, we introduce an anisotropic growth tensor that can capture both hypertrophic wall thickening and ventricular dilation within one generic concept. In agreement with clinical observations, we propose wall thickening to be a stress-driven phenomenon whereas dilation is introduced as a strain-driven process. The features of the proposed approach are illustrated in terms of the adaptation of thin heart slices and in terms overload-induced dilation in a generic bi-ventricular heart model.

  15. Angiotensin degradation products mediate endothelium-dependent dilation of rabbit brain arterioles.

    PubMed

    Haberl, R L; Decker, P J; Einhäupl, K M

    1991-06-01

    This study demonstrates that the hexapeptide angiotensin II-(3-8) and L-arginine, generated through enzymatic degradation of angiotensin, mediate endothelium-dependent dilation in rabbit brain arterioles. Topical application of angiotensin II (10(-5) M) on the brain surface of anesthetized rabbits caused 21.6 +/- 4.5% (mean +/- SEM) cerebral arteriolar dilation. The cyclooxygenase inhibitor indomethacin did not change this dilation. The natural degradation product of angiotensin II in the brain, angiotensin III, also induced vasodilation at concentrations of 10(-7) to 10(-5) M. The dilation to angiotensin II and angiotensin III was eliminated in the presence of 10(-5) M methylene blue, a known inhibitor of endothelium-dependent vasodilation. Amastatin, an aminopeptidase inhibitor and blocker of enzymatic angiotensin degradation, also inhibited the response to angiotensin II and angiotensin III. The angiotensin fragment angiotensin II-(3-8), which lacks the amino-terminal L-arginine residue of angiotensin III, did not elicit an arteriolar response. When angiotensin II-(3-8) was topically applied subsequent to L-arginine, a 21.2 +/- 2.9% vasodilation was observed. L-Arginine itself induced only moderate vasodilation with a maximum of 4.0 +/- 0.9% at 10(-5) M L-arginine. The dilating response to angiotensin II-(3-8) after L-arginine was inhibited by methylene blue. It was not affected by amastatin. It is concluded that degradation products of angiotensin, rather than angiotensin II itself, induce endothelium-dependent dilation in rabbit brain arterioles without involvement of cyclooxygenase products.(ABSTRACT TRUNCATED AT 250 WORDS)

  16. Technique of percutaneous laser-assisted valve dilatation for valvar atresia in congenital heart disease.

    PubMed Central

    Rosenthal, E; Qureshi, S A; Kakadekar, A P; Anjos, R; Baker, E J; Tynan, M

    1993-01-01

    OBJECTIVE--To investigate the efficacy and safety of transcatheter laser-assisted valve dilatation for atretic valves in children with congenital heart disease. DESIGN--Prospective clinical study. SETTING--Supraregional paediatric cardiology centre. SUBJECTS--Eleven children (aged 1 day-11 years; weight 2.1-35.7 kg) with atresia of pulmonary (10) or tricuspid (one) valve underwent attempted laser-assisted valve dilatation as part of the staged treatment of their cyanotic heart disease. INTERVENTION--After delineating the atretic valve by angiography and/or echocardiography a 0.018 inch "hot tip" laser wire was used to perforate the atretic valve. Subsequently the valve was dilated with conventional balloon dilatation catheters up to the valve annulus diameter. RESULTS--Laser-assisted valve dilatation was successfully accomplished in nine children. In two neonates with pulmonary valve atresia, intact ventricular septum, and coexistent infundibular atresia the procedure resulted in cardiac tamponade: one died immediately and one later at surgery. During a follow up of 1-17 months (mean 11) two infants with pulmonary valve atresia and intact ventricular septum died (one with congestive cardiac failure). The remainder are either well palliated and do not require further procedures (three), or are awaiting further transcatheter or surgical procedures because of associated defects (four). CONCLUSIONS--Laser-assisted valve dilatation is a promising adjunct to surgery in this high risk group of patients. It may avoid surgery in some patients, and may reduce the number of surgical procedures in those requiring staged operations. Images PMID:8343325

  17. Experimental Investigation on Dilation Mechanisms of Land-Facies Karamay Oil Sand Reservoirs under Water Injection

    NASA Astrophysics Data System (ADS)

    Lin, Botao; Jin, Yan; Pang, Huiwen; Cerato, Amy B.

    2016-04-01

    The success of steam-assisted gravity drainage (SAGD) is strongly dependent on the formation of a homogeneous and highly permeable zone in the land-facies Karamay oil sand reservoirs. To accomplish this, hydraulic fracturing is applied through controlled water injection to a pair of horizontal wells to create a dilation zone between the dual wells. The mechanical response of the reservoirs during this injection process, however, has remained unclear for the land-facies oil sand that has a loosely packed structure. This research conducted triaxial, permeability and scanning electron microscopy (SEM) tests on the field-collected oil sand samples. The tests evaluated the influences of the field temperature, confining stress and injection pressure on the dilation mechanisms as shear dilation and tensile parting during injection. To account for petrophysical heterogeneity, five reservoir rocks including regular oil sand, mud-rich oil sand, bitumen-rich oil sand, mudstone and sandstone were investigated. It was found that the permeability evolution in the oil sand samples subjected to shear dilation closely followed the porosity and microcrack evolutions in the shear bands. In contrast, the mudstone and sandstone samples developed distinct shear planes, which formed preferred permeation paths. Tensile parting expanded the pore space and increased the permeability of all the samples in various degrees. Based on this analysis, it is concluded that the range of injection propagation in the pay zone determines the overall quality of hydraulic fracturing, while the injection pressure must be carefully controlled. A region in a reservoir has little dilation upon injection if it remains unsaturated. Moreover, a cooling of the injected water can strengthen the dilation potential of a reservoir. Finally, it is suggested that the numerical modeling of water injection in the Karamay oil sand reservoirs must take into account the volumetric plastic strain in hydrostatic loading.

  18. Idiopathic dilated cardiomyopathy: computerized anatomic study of relashionship between septal and free left ventricle wall

    PubMed Central

    Juliani, Paulo Sérgio; da Costa, Éder França; Correia, Aristides Tadeu; Monteiro, Rosangela; Jatene, Fabio Biscegli

    2014-01-01

    Introduction A feature of dilated cardiomyopathy is the deformation of ventricular cavity, which contributes to systolic dysfunction. Few studies have evaluated this deformation bearing in mind ventricular regions and segments of the ventricle, which could reveal important details of the remodeling process, supporting a better understanding of its role in functional impairment and the development of new therapeutic strategies. Objective To evaluate if, in basal, equatorial and apical regions, increased internal transverse perimeter of left ventricle in idiopathic dilated cardiomyopathy occurs proportionally between the septal and non-septal segment. Methods We performed an anatomical study with 28 adult hearts from human cadavers. One group consisted of 18 hearts with idiopathic dilated cardiomyopathy and another group with 10 normal hearts. After lamination and left ventricle digital image capture, in three different regions (base, equator and apex), the transversal internal perimeter of left ventricle was divided into two segments: septal and not septal. These segments were measured by proper software. It was established an index of proportionality between these segments, called septal and non-septal segment index. Then we determined whether this index was the same in both groups. Results Among patients with normal hearts and idiopathic dilated cardiomyopathy, the index of proportionality between the two segments (septal and non-septal) showed no significant difference in the three regions analyzed. The comparison results of the indices NSS/SS among normal and enlarged hearts were respectively: in base 1.99 versus 1.86 (P=0.46), in equator 2.22 versus 2.18 (P=0.79) and in apex 2.96 versus 3.56 (P=0.11). Conclusion In the idiopathic dilated cardiomyopathy, the transversal dilatation of left ventricular internal perimeter occurs proportionally between the segments corresponding to the septum and free wall at the basal, equatorial and apical regions of this chamber

  19. Dilatation of Common Iliac Arteries after Endovascular Infrarenal Abdominal Aortic Repair with Bell-Bottom Extension

    PubMed Central

    Telles, Gustavo José Politzer; Razuk Filho, Álvaro; Karakhanian, Walter Khegan; Saad, Paulo Fernandes; Saad, Karen Ruggeri; Park, Jong Hun; Siqueira, Leticia Cristina Dalledone; Caffaro, Roberto Augusto

    2016-01-01

    Objective Endovascular techniques to treat abdominal aortic aneurysms results in lower morbidity and mortality rates. However, dilation of the common iliac arteries prevents adequate distal sealing, which compromises the procedure success. The aim of this study is report the long-term outcomes of patients with abdominal aortic aneurysms associated with aneurysm of the common iliac artery following endovascular repair using a bifurcated bell-bottom stent graft. Methods This is a retrospective study that evaluated patients treated with bifurcated bell-bottom extension stent grafts to repair an infrarenal abdominal aortic aneurysm and who had at least one common iliac artery with dilatation > 1.5 cm for at least 12 months after the endovascular intervention. Results Thirty-eight patients with a mean age of 70.4±8.2 years were included. Stent graft placement was followed by dilation of the common iliac artery aneurysms in 35.3% of cases; endoleak and reoperation rates were 17.6% and 15.7%, respectively. Younger patients showed a higher rate of artery diameter increase following the procedure. The average arterial dilation was 16% in the first year, 29% in the second year, 57% in the third year and 95% from the fourth year until the end of follow-up. Conclusion Repair of infrarenal abdominal aortic aneurysms with bifurcated bell-bottom type stents when there is common iliac artery dilation is a good therapeutic option to preserve hypogastric flow. The rate of endoleak was 17.6%, and 15.7% of cases required reoperation. Younger patients are more likely to experience dilation of the common iliac artery after the procedure. PMID:27556314

  20. The Frequency of Rapid Pupil Dilations as a Measure of Linguistic Processing Difficulty.

    PubMed

    Demberg, Vera; Sayeed, Asad

    2016-01-01

    While it has long been known that the pupil reacts to cognitive load, pupil size has received little attention in cognitive research because of its long latency and the difficulty of separating effects of cognitive load from the light reflex or effects due to eye movements. A novel measure, the Index of Cognitive Activity (ICA), relates cognitive effort to the frequency of small rapid dilations of the pupil. We report here on a total of seven experiments which test whether the ICA reliably indexes linguistically induced cognitive load: three experiments in reading (a manipulation of grammatical gender match/mismatch, an experiment of semantic fit, and an experiment comparing locally ambiguous subject versus object relative clauses, all in German), three dual-task experiments with simultaneous driving and spoken language comprehension (using the same manipulations as in the single-task reading experiments), and a visual world experiment comparing the processing of causal versus concessive discourse markers. These experiments are the first to investigate the effect and time course of the ICA in language processing. All of our experiments support the idea that the ICA indexes linguistic processing difficulty. The effects of our linguistic manipulations on the ICA are consistent for reading and auditory presentation. Furthermore, our experiments show that the ICA allows for usage within a multi-task paradigm. Its robustness with respect to eye movements means that it is a valid measure of processing difficulty for usage within the visual world paradigm, which will allow researchers to assess both visual attention and processing difficulty at the same time, using an eye-tracker. We argue that the ICA is indicative of activity in the locus caeruleus area of the brain stem, which has recently also been linked to P600 effects observed in psycholinguistic EEG experiments. PMID:26799065

  1. The Frequency of Rapid Pupil Dilations as a Measure of Linguistic Processing Difficulty.

    PubMed

    Demberg, Vera; Sayeed, Asad

    2016-01-01

    While it has long been known that the pupil reacts to cognitive load, pupil size has received little attention in cognitive research because of its long latency and the difficulty of separating effects of cognitive load from the light reflex or effects due to eye movements. A novel measure, the Index of Cognitive Activity (ICA), relates cognitive effort to the frequency of small rapid dilations of the pupil. We report here on a total of seven experiments which test whether the ICA reliably indexes linguistically induced cognitive load: three experiments in reading (a manipulation of grammatical gender match/mismatch, an experiment of semantic fit, and an experiment comparing locally ambiguous subject versus object relative clauses, all in German), three dual-task experiments with simultaneous driving and spoken language comprehension (using the same manipulations as in the single-task reading experiments), and a visual world experiment comparing the processing of causal versus concessive discourse markers. These experiments are the first to investigate the effect and time course of the ICA in language processing. All of our experiments support the idea that the ICA indexes linguistic processing difficulty. The effects of our linguistic manipulations on the ICA are consistent for reading and auditory presentation. Furthermore, our experiments show that the ICA allows for usage within a multi-task paradigm. Its robustness with respect to eye movements means that it is a valid measure of processing difficulty for usage within the visual world paradigm, which will allow researchers to assess both visual attention and processing difficulty at the same time, using an eye-tracker. We argue that the ICA is indicative of activity in the locus caeruleus area of the brain stem, which has recently also been linked to P600 effects observed in psycholinguistic EEG experiments.

  2. The Frequency of Rapid Pupil Dilations as a Measure of Linguistic Processing Difficulty

    PubMed Central

    Demberg, Vera; Sayeed, Asad

    2016-01-01

    While it has long been known that the pupil reacts to cognitive load, pupil size has received little attention in cognitive research because of its long latency and the difficulty of separating effects of cognitive load from the light reflex or effects due to eye movements. A novel measure, the Index of Cognitive Activity (ICA), relates cognitive effort to the frequency of small rapid dilations of the pupil. We report here on a total of seven experiments which test whether the ICA reliably indexes linguistically induced cognitive load: three experiments in reading (a manipulation of grammatical gender match / mismatch, an experiment of semantic fit, and an experiment comparing locally ambiguous subject versus object relative clauses, all in German), three dual-task experiments with simultaneous driving and spoken language comprehension (using the same manipulations as in the single-task reading experiments), and a visual world experiment comparing the processing of causal versus concessive discourse markers. These experiments are the first to investigate the effect and time course of the ICA in language processing. All of our experiments support the idea that the ICA indexes linguistic processing difficulty. The effects of our linguistic manipulations on the ICA are consistent for reading and auditory presentation. Furthermore, our experiments show that the ICA allows for usage within a multi-task paradigm. Its robustness with respect to eye movements means that it is a valid measure of processing difficulty for usage within the visual world paradigm, which will allow researchers to assess both visual attention and processing difficulty at the same time, using an eye-tracker. We argue that the ICA is indicative of activity in the locus caeruleus area of the brain stem, which has recently also been linked to P600 effects observed in psycholinguistic EEG experiments. PMID:26799065

  3. Inadvertent migration of guidewire into Murphy's eye of endotracheal tube during percutaneous dilatational tracheostomy

    PubMed Central

    Panigrahi, Binita; Samaddar, Devi Prasad; Kumar, Tushar

    2016-01-01

    Percutaneous dilatational tracheostomy is a commonly performed bedside procedure in the Intensive Care Unit. Although serious and fatal complications have been reported, the procedure is by and large safe to perform in experienced hands. We report here an innocuous problem encountered twice. After the guidewire insertion and dilatation, subsequent railroading became difficult owing to migration of guidewire into the Murphy's eye of the endotracheal tube (ETT). Awareness about this possibility can avert inadvertent delays and complications during the procedure. A tug or gentle pulling of ETT after insertion of the guidewire rules out an impaction in the eye or other part of the ETT. PMID:27076734

  4. Use of osmotic dilators to facilitate induced midtrimester abortion: clinical evaluations.

    PubMed

    Atienza, M F; Burkman, R T; King, T M

    1984-09-01

    A number of studies evaluating an osmotic cervical dilator consisting of polyvinyl foam saturated with magnesium sulphate in women undergoing midtrimester abortion with intra-amniotic hyperosmolar urea plus prostaglandin F2a were completed. Comparisons with women receiving no pre-treatment with a laminaria tent or with one laminaria indicate that their use appears to shorten injection-abortion intervals, particularly in parous women, and reduce risk of endometritis and cervical laceration compared to women not receiving any type of device. The data suggests that two osmotic dilators may be more effective than one. Also, magnesium toxicity does not appear to be a substantial risk with their use. PMID:6595099

  5. Non-invasive evaluation of arrhythmic risk in dilated cardiomyopathy: From imaging to electrocardiographic measures

    PubMed Central

    Iacoviello, Massimo; Monitillo, Francesco

    2014-01-01

    Malignant ventricular arrhythmias are a major adverse event and worsen the prognosis of patients affected by ischemic and non-ischemic dilated cardiomyopathy. The main parameter currently used to stratify arrhythmic risk and guide decision making towards the implantation of a cardioverter defibrillator is the evaluation of the left ventricular ejection fraction. However, this strategy is characterized by several limitations and consequently additional parameters have been suggested in order to improve arrhythmic risk stratification. The aim of this review is to critically revise the prognostic significance of non-invasive diagnostic tools in order to better stratify the arrhythmic risk prognosis of dilated cardiomyopathy patients. PMID:25068017

  6. Prevention of stricture recurrence following urethral internal urethrotomy: routine repeated dilations or active surveillance?

    PubMed

    Tian, Ye; Wazir, Romel; Wang, Jianzhong; Wang, Kunjie; Li, Hong

    2016-01-01

    Strictures of the urethra are the most common cause of obstructed micturition in younger men and there is frequent recurrence after initial treatment. Currently, routine repeated dilations, including intermittent self-catheterisation (ISC) are prescribed by urologists to prevent urethral stricture recurrence. There is, however, no high level evidence available supporting the effectiveness of practicing these painful techniques. Balancing efficacy, adverse effects and costs, we hypothesize that active surveillance is a better option for preventing stricture recurrence as compared with routine repeated dilations. However, well designed, adequately powered multi-center trials with comprehensive evaluation are urgently needed to confirm our hypothesis. .

  7. Prevention of stricture recurrence following urethral internal urethrotomy: routine repeated dilations or active surveillance?

    PubMed

    Tian, Ye; Wazir, Romel; Wang, Jianzhong; Wang, Kunjie; Li, Hong

    2016-01-01

    Strictures of the urethra are the most common cause of obstructed micturition in younger men and there is frequent recurrence after initial treatment. Currently, routine repeated dilations, including intermittent self-catheterisation (ISC) are prescribed by urologists to prevent urethral stricture recurrence. There is, however, no high level evidence available supporting the effectiveness of practicing these painful techniques. Balancing efficacy, adverse effects and costs, we hypothesize that active surveillance is a better option for preventing stricture recurrence as compared with routine repeated dilations. However, well designed, adequately powered multi-center trials with comprehensive evaluation are urgently needed to confirm our hypothesis. . PMID:27576888

  8. Endovascular Repair of a Traumatic Thoracic Aortic Injury Resulting in Late Aortic Dilatation

    PubMed Central

    Ozaki, Kumi; Matsui, Osamu; Ohtake, Hiroshi; Watanabe, Go; anada, Junichiro

    2013-01-01

    We present an unusual complication following endovascular repair of traumatic thoracic aortic injury using a homemade stent-graft. Although an initial technical success was apparently obtained, the aorta showed remarkable dilatation without shortening or migration of the stent skeleton in late follow-up period. The possible cause of the dilatation was considered to be the expansion and gathering of the crimped, loosely attached, graft fabric in addition to the incomplete exclusion due to the insufficient landing zone and the limited radial force. Thus, the specific feature of stent-graft, considered to provide an advantage to treatment, has adversely affected the native aorta. PMID:24436598

  9. Pupil dilatation with tropicamide. The effects on acuity, accommodation and refraction.

    PubMed

    Montgomery, D M; MacEwan, C J

    1989-01-01

    The effect of pupil dilatation with tropicamide 1% on visual acuity and accommodation was assessed in 100 eyes of 52 consecutive patients attending the general ophthalmic outpatient clinic. Snellen visual acuity remained unchanged in 55 eyes and deteriorated by one line in 41 eyes. The remaining four eyes deteriorated by two lines. Tropicamide gave rise to a reduction in the amplitude of accommodation which tended to vary inversely with the age of the patient. However, all patients who wore reading glasses for presbyopia were still able to read when their pupils had been dilated.

  10. Curcumin ingestion and exercise training improve vascular endothelial function in postmenopausal women.

    PubMed

    Akazawa, Nobuhiko; Choi, Youngju; Miyaki, Asako; Tanabe, Yoko; Sugawara, Jun; Ajisaka, Ryuichi; Maeda, Seiji

    2012-10-01

    Vascular endothelial function is declines with aging and is associated with an increased risk of cardiovascular disease. Lifestyle modification, particularly aerobic exercise and dietary adjustment, has a favorable effect on vascular aging. Curcumin is a major component of turmeric with known anti-inflammatory and anti-oxidative effects. We investigated the effects of curcumin ingestion and aerobic exercise training on flow-mediated dilation as an indicator endothelial function in postmenopausal women. A total of 32 postmenopausal women were assigned to 3 groups: control, exercise, and curcumin groups. The curcumin group ingested curcumin orally for 8 weeks. The exercise group underwent moderate aerobic exercise training for 8 weeks. Before and after each intervention, flow-mediated dilation was measured. No difference in baseline flow-mediated dilation or other key dependent variables were detected among the groups. Flow-mediated dilation increased significantly and equally in the curcumin and exercise groups, whereas no changes were observed in the control group. Our results indicated that curcumin ingestion and aerobic exercise training can increase flow-mediated dilation in postmenopausal women, suggesting that both can potentially improve the age-related decline in endothelial function.

  11. Efficacy and safety of endoscopic papillary balloon dilation for the removal of bile duct stones: Data from a “real-life” multicenter study on Dilation-Assisted Stone Extraction

    PubMed Central

    Di Mitri, Roberto; Mocciaro, Filippo; Pallio, Socrate; Pecoraro, Giulia Maria; Tortora, Andrea; Zulli, Claudio; Attardo, Simona; Maurano, Attilio

    2016-01-01

    AIM To report data on Dilation-Assisted Stone Extraction (DASE) use in clinical practice and its efficacy and safety trough three Italian referral centers for biliopancreatic diseases treatment. METHODS From January 2011 to December 2015 we collected data on 120 patients treated with DASE. Technical success was obtained when the endoscopist was able to place the balloon trough the papilla inflating the balloon until the final diameter for an adequate time (at least 30 s). Clinical success was obtained after complete stone removal (no remaining stones were visible at the cholangiogram). RESULTS Forty-nine male (40.8%) and 71 female (59%) were enrolled. The mean age was 67.8 years ± 15.7. The mean common bile duct (CBD) dilation was 19.2 mm ± 3.9 and the mean size of stones 15.8 ± 2.9. DASE was applied as first approach in 38% (62% after initial failure of stones extraction). Technical and clinical success was of 91% and 87% respectively. In those in which DASE failed alternative treatment were adopted. After DASE 18% of patients experienced a complication (bleeding 9%, pancreatitis 8%, perforation 0.8%). At univariable analysis, elective endoscopic retrograde cholangiopancreatography (P = 0.031), DASE as first approach (P = 0.032), and cannulation of major papilla followed by guidewire insertion (P = 0.004) were related to low risk of complications. Pre-cut was related to an increased risk of complications (P = 0.01). CONCLUSION DASE allowed a higher first-session success rate and can be consider a valid alternative to endoscopic sphincterotomy not only for bigger CBD stones. PMID:27803771

  12. Progress with genetic cardiomyopathies: screening, counseling, and testing in dilated, hypertrophic, and arrhythmogenic right ventricular dysplasia/cardiomyopathy.

    PubMed

    Hershberger, Ray E; Cowan, Jason; Morales, Ana; Siegfried, Jill D

    2009-05-01

    This review focuses on the genetic cardiomyopathies: principally dilated cardiomyopathy, with salient features of hypertrophic cardiomyopathy and arrhythmogenic right ventricular dysplasia/cardiomyopathy, regarding genetic etiology, genetic testing, and genetic counseling. Enormous progress has recently been made in identifying genetic causes for each cardiomyopathy, and key phenotype and genotype information is reviewed. Clinical genetic testing is rapidly emerging with a principal rationale of identifying at-risk asymptomatic or disease-free relatives. Knowledge of a disease-causing mutation can guide clinical surveillance for disease onset, thereby enhancing preventive and treatment interventions. Genetic counseling is also indicated for patients and their family members regarding the symptoms of their cardiomyopathy, its inheritance pattern, family screening recommendations, and genetic testing options and possible results.

  13. [Acute stent thrombosis and reverse transient left ventricular dilatation after performing a single-photon emission computed tomography myocardial perfusion].

    PubMed

    Miranda, B; Pizzi, M N; Aguadé-Bruix, S; Domingo, E; Candell-Riera, J

    2015-01-01

    A 63-year-old male patient with a history of stent implantation in the left anterior descending three months before. Due to the presentation of vegetative symptoms, he was referred for gated-SPECT myocardial perfusion. During acquisition of the resting images he presented chest pain and ST segment elevation, so that urgent cardiac catheterization was performed, showing stent thrombosis. Rest perfusion imaging showed a defect in anterior and apical perfusion, more severe and extensive than in the stress images, with striking left ventricular dilatation and a fall in the ejection fraction related to the acute ischemia phenomenon. Intense exercise is associated with a transient activation of the coagulation system and hemodynamic changes that might induce thrombosis, especially in recently implanted coronary stents that probably still have not become completely endothelialized.

  14. Multiple risk factors for the gastric dilatation-volvulus syndrome in dogs: a practitioner/owner case-control study.

    PubMed

    Glickman, L T; Glickman, N W; Schellenberg, D B; Simpson, K; Lantz, G C

    1997-01-01

    A study was conducted of 101 dogs (i.e., case dogs) that had acute episodes of gastric dilatation-volvulus (GDV) and 101 dogs (i.e., control dogs) with nonGDV-related problems. The control dogs were matched individually to case dogs by breed or size, and age. Predisposing factors that significantly (p less than 0.10) increased a dog's risk of GDV were male gender, being underweight, eating one meal daily, eating rapidly, and a fearful temperament. Predisposing factors that decreased the risk of GDV significantly were a "happy" temperament and inclusion of table foods in a usual diet consisting primarily of dry dog food. The only factor that appeared to precipitate an acute episode of GDV was stress.

  15. The use of end-tidal carbon dioxide monitoring to confirm intratracheal cannula placement prior to percutaneous dilatational tracheostomy.

    PubMed

    Coleman, N A; Power, B M; van Heerden, P V

    2000-04-01

    We tested the utility of intratracheal carbon dioxide monitoring (IT-CO2) in 10 patients undergoing percutaneous dilatational tracheostomy (PDT). We have found IT-CO2 monitoring reliable in confirming the correct position of the tracheal cannula prior to tracheal dilatation using the Portex technique.

  16. Ventricular dilatation in the absence of ACE inhibitors: influence of haemodynamic and neurohormonal variables following myocardial infarction

    PubMed Central

    Walsh, J; Batin, P; Hawkins, M; McEntegart, D; Cowley, A

    1999-01-01

    Objective—To examine the relation between patterns of ventricular remodelling and haemodynamic and neurohormonal variables, at rest and during symptom limited exercise, in the year following acute myocardial infarction in patients not receiving angiotensin converting enzyme (ACE) inhibitors.
Design—A prospective observational study.
Patients—65 patients recruited following hospital admission with a transmural anterior myocardial infarction.
Methods—Central haemodynamics and neurohormonal activation at rest and during symptom limited treadmill exercise were measured at baseline before hospital discharge, one month later, and at three monthly intervals thereafter. Patients were classified according to individual patterns of change in left ventricular end diastolic volumes at rest, assessed at each visit using transthoracic echocardiography.
Results—In most patients (n = 43, 66%) ventricular volumes were unchanged or reduced. Mean (SEM) treadmill exercise capacity and peak exercise cardiac index increased at month 12 by 200 (24) seconds (p < 0.001 v baseline) and by 0.8 (0.4) l/min/m2 (p<0.05 v baseline), respectively, in this group. In patients with limited ventricular dilatation (n = 11, 17%) exercise capacity increased by 259 (52) seconds (p < 0.001 v baseline) and peak exercise cardiac index improved by 0.8 (0.7) l/min/m2 (NS). In the remaining 11 patients with progressive left ventricular dilatation, exercise capacity increased by 308 (53) seconds (p< 0.001 v baseline) and peak exercise cardiac index similarly improved by 1.3 (0.7) l/min/m2 (NS). There were trends towards increased atrial natriuretic factor (ANF) secretion at rest and at peak exercise in this group.
Conclusions—Ventricular dilatation after acute myocardial infarction is a heterogeneous process that is progressive in only a minority of patients. Compensatory mechanisms, including ANF release, appear capable of maintaining and improving exercise capacity in

  17. Cardiomyocyte-Specific Ablation of Med1 Subunit of the Mediator Complex Causes Lethal Dilated Cardiomyopathy in Mice.

    PubMed

    Jia, Yuzhi; Chang, Hsiang-Chun; Schipma, Matthew J; Liu, Jing; Shete, Varsha; Liu, Ning; Sato, Tatsuya; Thorp, Edward B; Barger, Philip M; Zhu, Yi-Jun; Viswakarma, Navin; Kanwar, Yashpal S; Ardehali, Hossein; Thimmapaya, Bayar; Reddy, Janardan K

    2016-01-01

    Mediator, an evolutionarily conserved multi-protein complex consisting of about 30 subunits, is a key component of the polymerase II mediated gene transcription. Germline deletion of the Mediator subunit 1 (Med1) of the Mediator in mice results in mid-gestational embryonic lethality with developmental impairment of multiple organs including heart. Here we show that cardiomyocyte-specific deletion of Med1 in mice (csMed1-/-) during late gestational and early postnatal development by intercrossing Med1fl/fl mice to α-MyHC-Cre transgenic mice results in lethality within 10 days after weaning due to dilated cardiomyopathy-related ventricular dilation and heart failure. The csMed1-/- mouse heart manifests mitochondrial damage, increased apoptosis and interstitial fibrosis. Global gene expression analysis revealed that loss of Med1 in heart down-regulates more than 200 genes including Acadm, Cacna1s, Atp2a2, Ryr2, Pde1c, Pln, PGC1α, and PGC1β that are critical for calcium signaling, cardiac muscle contraction, arrhythmogenic right ventricular cardiomyopathy, dilated cardiomyopathy and peroxisome proliferator-activated receptor regulated energy metabolism. Many genes essential for oxidative phosphorylation and proper mitochondrial function such as genes coding for the succinate dehydrogenase subunits of the mitochondrial complex II are also down-regulated in csMed1-/- heart contributing to myocardial injury. Data also showed up-regulation of about 180 genes including Tgfb2, Ace, Atf3, Ctgf, Angpt14, Col9a2, Wisp2, Nppa, Nppb, and Actn1 that are linked to cardiac muscle contraction, cardiac hypertrophy, cardiac fibrosis and myocardial injury. Furthermore, we demonstrate that cardiac specific deletion of Med1 in adult mice using tamoxifen-inducible Cre approach (TmcsMed1-/-), results in rapid development of cardiomyopathy and death within 4 weeks. We found that the key findings of the csMed1-/- studies described above are highly reproducible in TmcsMed1-/- mouse heart

  18. Cardiomyocyte-Specific Ablation of Med1 Subunit of the Mediator Complex Causes Lethal Dilated Cardiomyopathy in Mice

    PubMed Central

    Jia, Yuzhi; Chang, Hsiang-Chun; Schipma, Matthew J.; Liu, Jing; Shete, Varsha; Liu, Ning; Sato, Tatsuya; Thorp, Edward B.; Barger, Philip M.; Zhu, Yi-Jun; Viswakarma, Navin; Kanwar, Yashpal S.; Ardehali, Hossein; Thimmapaya, Bayar; Reddy, Janardan K.

    2016-01-01

    Mediator, an evolutionarily conserved multi-protein complex consisting of about 30 subunits, is a key component of the polymerase II mediated gene transcription. Germline deletion of the Mediator subunit 1 (Med1) of the Mediator in mice results in mid-gestational embryonic lethality with developmental impairment of multiple organs including heart. Here we show that cardiomyocyte-specific deletion of Med1 in mice (csMed1-/-) during late gestational and early postnatal development by intercrossing Med1fl/fl mice to α-MyHC-Cre transgenic mice results in lethality within 10 days after weaning due to dilated cardiomyopathy-related ventricular dilation and heart failure. The csMed1-/- mouse heart manifests mitochondrial damage, increased apoptosis and interstitial fibrosis. Global gene expression analysis revealed that loss of Med1 in heart down-regulates more than 200 genes including Acadm, Cacna1s, Atp2a2, Ryr2, Pde1c, Pln, PGC1α, and PGC1β that are critical for calcium signaling, cardiac muscle contraction, arrhythmogenic right ventricular cardiomyopathy, dilated cardiomyopathy and peroxisome proliferator-activated receptor regulated energy metabolism. Many genes essential for oxidative phosphorylation and proper mitochondrial function such as genes coding for the succinate dehydrogenase subunits of the mitochondrial complex II are also down-regulated in csMed1-/- heart contributing to myocardial injury. Data also showed up-regulation of about 180 genes including Tgfb2, Ace, Atf3, Ctgf, Angpt14, Col9a2, Wisp2, Nppa, Nppb, and Actn1 that are linked to cardiac muscle contraction, cardiac hypertrophy, cardiac fibrosis and myocardial injury. Furthermore, we demonstrate that cardiac specific deletion of Med1 in adult mice using tamoxifen-inducible Cre approach (TmcsMed1-/-), results in rapid development of cardiomyopathy and death within 4 weeks. We found that the key findings of the csMed1-/- studies described above are highly reproducible in TmcsMed1-/- mouse heart

  19. Circulating Omentin-1 Levels Are Decreased in Dilated Cardiomyopathy Patients with Overt Heart Failure.

    PubMed

    Huang, Ying; Lin, Yingzhong; Zhang, Shumin; Wang, Zhijian; Zhang, Jianwei; Chang, Chao; Liu, Ling; Ji, Qingwei; Liu, Xiaofei

    2016-01-01

    Background. Recent evidence demonstrated that the circulating levels of omentin-1 are related to the presence of ischemic heart disease and heart failure. However, omentin-1 plasma levels in patients with nonischemic dilated cardiomyopathy (DCM), which is the most common etiology of heart failure, have yet to be investigated. Methods. Plasma levels of omentin-1 and adiponectin were measured in 100 patients with DCM and 45 healthy controls. Results. Plasma omentin-1 levels significantly decreased in DCM patients compared with the control group, whereas adiponectin levels significantly increased in DCM patients compared with the control group. Plasma omentin-1 levels were negatively correlated with adiponectin (R = -0.376, P = 0.005), C-reactive protein (CRP) (R = -0.320, P = 0.001), and N-terminal pro-brain natriuretic peptide (NT-proBNP) (R = -0.365, P = 0.000) levels as well as left ventricular end-diastolic diameter (LVEDD) (R = -0.200, P = 0.046) but were positively correlated with left ventricular ejection fraction (LVEF) (R = 0.496, P = 0.000). Plasma adiponectin levels were positively correlated with CRP (R = 0.273, P = 0.006) and NT-proBNP (R = 0.329, P = 0.001) levels but were negatively correlated with fasting glucose (R = -0.218, P = 0.029) and LVEF (R = -0.615, P = 0.000) levels. Furthermore, omentin-1 (OR 0.983, 95% CI 0.970 to 0.996; P = 0.008) levels were independently associated with the presence of DCM before NT-proBNP was added. Conclusions. Omentin-1 is a novel biomarker of DCM. PMID:27313334

  20. Ventricular dilatation and brain atrophy in patients with Parkinson's disease with incipient dementia.

    PubMed

    Camicioli, Richard; Sabino, Jennifer; Gee, Myrlene; Bouchard, Thomas; Fisher, Nancy; Hanstock, Chris; Emery, Derek; Martin, W R Wayne

    2011-07-01

    Age-related ventricular enlargement is accelerated in Alzheimer's disease, but its relationship to cognitive decline in Parkinson's disease is less clear, even though dementia is common in Parkinson's disease. Our goals were to determine if greater enlargement of the ventricles and gray or white matter atrophy occurred in Parkinson's disease patients developing cognitive decline. Older nondemented patients with Parkinson's disease (33) and age- and sex-matched controls (39) were recruited and prospectively assessed for the development of significant cognitive decline over 36 months. Magnetic resonance imaging was obtained every 18 months, and ventricular volume and total brain gray and white matter volumes were measured using reliable segmentation of T1-weighted volumetric scans. Subjects with incidental intracranial abnormalities, an atypical course, and stroke as well as dropouts were excluded from a cohort of 52 patients and 50 controls. Among 33 patients and 39 controls, 10 patients and 3 controls developed significant cognitive impairment or dementia. Ventricular change and Parkinson's disease status were significantly associated with dementia. Ventricular change was significantly correlated with change in Mini-Mental Status Examination in the Parkinson's disease with dementia group (r = 0.87, P = .001). Gray matter atrophy was greater in Parkinson's disease with dementia, with similar change over time in both Parkinson's disease and Parkinson's disease with dementia. White matter volumes were not significantly different between Parkinson's disease and Parkinson's disease with dementia; however, the decrease over time might be greater in Parkinson's disease with dementia. Ventricular dilatation occurs early in the course of significant cognitive decline in patients with Parkinson's disease, possibly reflecting both cortical gray and white matter loss. PMID:21442661

  1. Flow structures and red blood cell dynamics in arteriole of dilated or constricted cross section.

    PubMed

    Gambaruto, Alberto M

    2016-07-26

    Vessel with 'circular' or 'star-shaped' cross sections are studied, representing respectively dilated or constricted cases where endothelial cells smoothly line or bulge into the lumen. Computational haemodynamics simulations are carried out on idealised periodic arteriole-sized vessels, with red blood cell 'tube' hematocrit value=24%. A further simulation of a single red blood cell serves for comparison purposes. The bulk motion of the red blood cells reproduces well-known effects, including the presence of a cell-free layer and the apparent shear-thinning non-Newtonian rheology. The velocity flow field is analysed in a Lagrangian reference frame, relative to any given red blood cell, hence removing the bulk coaxial motion and highlighting instead the complex secondary flow patterns. An aggregate formation becomes apparent, continuously rearranging and dynamic, brought about by the inter-cellular fluid mechanics interactions and the deformability properties of the cells. The secondary flow field induces a vacillating radial migration of the red blood cells. At different radial locations, the red blood cells express different residence times, orientation and shape. The shear stresses exerted by the flow on the vessel wall are influenced by the motion of red blood cells, despite the presence of the cell-free layer. Spatial (and temporal) variations of wall shear stress patters are observed, especially for the 'circular' vessel. The 'star-shaped' vessel bears considerable stress at the protruding endothelial cell crests, where the stress vectors are coaxially aligned. The bulging endothelial cells hence regularise the transmission of stresses on the vessel wall. PMID:26822224

  2. Flow structures and red blood cell dynamics in arteriole of dilated or constricted cross section.

    PubMed

    Gambaruto, Alberto M

    2016-07-26

    Vessel with 'circular' or 'star-shaped' cross sections are studied, representing respectively dilated or constricted cases where endothelial cells smoothly line or bulge into the lumen. Computational haemodynamics simulations are carried out on idealised periodic arteriole-sized vessels, with red blood cell 'tube' hematocrit value=24%. A further simulation of a single red blood cell serves for comparison purposes. The bulk motion of the red blood cells reproduces well-known effects, including the presence of a cell-free layer and the apparent shear-thinning non-Newtonian rheology. The velocity flow field is analysed in a Lagrangian reference frame, relative to any given red blood cell, hence removing the bulk coaxial motion and highlighting instead the complex secondary flow patterns. An aggregate formation becomes apparent, continuously rearranging and dynamic, brought about by the inter-cellular fluid mechanics interactions and the deformability properties of the cells. The secondary flow field induces a vacillating radial migration of the red blood cells. At different radial locations, the red blood cells express different residence times, orientation and shape. The shear stresses exerted by the flow on the vessel wall are influenced by the motion of red blood cells, despite the presence of the cell-free layer. Spatial (and temporal) variations of wall shear stress patters are observed, especially for the 'circular' vessel. The 'star-shaped' vessel bears considerable stress at the protruding endothelial cell crests, where the stress vectors are coaxially aligned. The bulging endothelial cells hence regularise the transmission of stresses on the vessel wall.

  3. Integrated Left Ventricular Global Transcriptome and Proteome Profiling in Human End-Stage Dilated Cardiomyopathy

    PubMed Central

    Kaya, Namik; Muiya, Nzioka P.; AlHarazi, Olfat; Shinwari, Zakia; Andres, Editha

    2016-01-01

    Aims The disease pathways leading to idiopathic dilated cardiomyopathy (DCM) are still elusive. The present study investigated integrated global transcriptional and translational changes in human DCM for disease biomarker discovery. Methods We used identical myocardial tissues from five DCM hearts compared to five non-failing (NF) donor hearts for both transcriptome profiling using the ABI high-density oligonucleotide microarrays and proteome expression with One-Dimensional Nano Acquity liquid chromatography coupled with tandem mass spectrometry on the Synapt G2 system. Results We identified 1262 differentially expressed genes (DEGs) and 269 proteins (DEPs) between DCM cases and healthy controls. Among the most significantly upregulated (>5-fold) proteins were GRK5, APOA2, IGHG3, ANXA6, HSP90AA1, and ATP5C1 (p< 0.01). On the other hand, the most significantly downregulated proteins were GSTM5, COX17, CAV1 and ANXA3. At least ten entities were concomitantly upregulated on the two analysis platforms: GOT1, ALDH4A1, PDHB, BDH1, SLC2A11, HSP90AA1, HSP90AB1, H2AFV, HSPA5 and NDUFV1. Gene ontology analyses of DEGs and DEPs revealed significant overlap with enrichment of genes/proteins related to metabolic process, biosynthetic process, cellular component organization, oxidative phosphorylation, alterations in glycolysis and ATP synthesis, Alzheimer’s disease, chemokine-mediated inflammation and cytokine signalling pathways. Conclusion The concomitant use of transcriptome and proteome expression to evaluate global changes in DCM has led to the identification of sixteen commonly altered entities as well as novel genes, proteins and pathways whose cardiac functions have yet to be deciphered. This data should contribute towards better management of the disease. PMID:27711126

  4. Aneurysmal dilatation without distal obstruction: a rare complication of valved bovine jugular vein conduit.

    PubMed

    Qureshi, Ahmad Usaid; Abbaker, Abd-Elmoneim A; Sivalingam, Sivakumar; Latiff, Haifa A

    2014-04-01

    Valved bovine jugular vein (Contegra) conduit is considered a suitable choice for pediatric population with congenital heart defect requiring right ventricle to main pulmonary artery connection. Intermediate follow-up studies have shown the propensity of developing distal conduit stenosis and valve thrombosis. We present a rare case of aneurysmal dilatation of the conduit leading to valve failure requiring conduit explantation. PMID:24668992

  5. Dilatation of the Proximal Cystic Duct: Is It a Variant to "Type VI" Choledochal Cyst?

    PubMed

    Kaselas, Christos; Patoulias, Dimitrios; Patoulias, Ioannis; Spyridakis, Ioannis

    2016-06-01

    Choledochal cysts are rare congenital malformations, comprising of dilatation of the biliary tree of different localization. Classically, classification of choledochal cysts describes five variants of the disease. Type VI choledochal cyst is considered by many authors as the sixth variant of this classification and is described either as a dilatation of the cystic duct or as a cystic duct cyst. We present a rare case of cystic duct dilatation that presented with acute cholangiopancreatitis and a clinical picture consistent of a choledochal cyst in a 10-year-old female patient. Cholecystectomy with excision of the cystic duct was performed. Histopathologic examination did not reveal any findings consistent with choledochal cyst. Based on these findings we speculate that in our case the dilatation of the cystic duct is a variant to type VI choledochal cyst, based on the fact that no cystic-like malformation has been identified in histology. We provide details of the pre-operative work-up and compare them with intraoperative findings in order to increase awareness of the condition. PMID:27504348

  6. Flicker Adaptation of Low-Level Cortical Visual Neurons Contributes to Temporal Dilation

    ERIC Educational Resources Information Center

    Ortega, Laura; Guzman-Martinez, Emmanuel; Grabowecky, Marcia; Suzuki, Satoru

    2012-01-01

    Several seconds of adaptation to a flickered stimulus causes a subsequent brief static stimulus to appear longer in duration. Nonsensory factors, such as increased arousal and attention, have been thought to mediate this flicker-based temporal-dilation aftereffect. In this study, we provide evidence that adaptation of low-level cortical visual…

  7. A Novel method of ensuring safe and accurate dilatation during percutaneous nephrolithotomy

    PubMed Central

    Javali, Tarun; Pathade, Amey; Nagaraj, H. K.

    2015-01-01

    ABSTRACT Objective: To report our technique that helps locate the guidewire into the ureter enabling safe dilatation during PCNL. Materials and Methods: Cases in which the guidewire failed to pass into the ureter following successful puncture of the desired calyx were subjected to this technique. A second guidewire was passed through the outer sheath of a 9 Fr. metallic dilator cannula, passed over the first guidewire. The cannula and outer sheath were removed, followed by percutaneous passage of a 6/7.5 Fr ureteroscope between the two guidewires, monitoring its progress through both the endoscopic and fluoroscopic monitors. Once the stone was visualized in the calyx a guidewire was passed through the working channel and maneuvered past the stone into the pelvis and ureter under direct endoscopic vision. This was followed by routine tract dilatation. Results: This technique was employed in 85 out of 675 cases of PCNL carried out at our institute between Jan 2010 to June 2014. The mean time required for our technique, calculated from the point of introduction of the ureteroscope untill the successful passage of the guidewire down into the ureter was 95 seconds. There were no intraoperative or postoperative complications as a result of this technique. Guidewire could be successfully passed into the ureter in 82 out of 85 cases. Conclusions: Use of the ureteroscope introduced percutaneously through the puncture site in PCNL, is a safe and effective technique that helps in maneuvering the guidewire down into the ureter, which subsequently enables safe dilatation. PMID:26689529

  8. Dilated Cardiomyopathy in a Rio Grande Wild Turkey (Meleagris gallopavo intermedia) in Southern Utah, USA, 2013.

    PubMed

    Frame, David D; Kelly, E Jane; Van Wettere, Arnaud

    2015-07-01

    A male Rio Grande Wild Turkey (Meleagris gallopavo intermedia) living in semidomestication was submitted for necropsy. Emaciation, a greatly enlarged heart, and chronic passive congestion of the liver were present. Dilated cardiomyopathy occurs in domestic turkey flocks but has not been reported in Wild Turkeys.

  9. [Clinical case of the month. Cardiac complications of acromegaly: a rare cause of dilated cardiomyopathy].

    PubMed

    Devoitille, A; Beckers, A; Piérard, L A

    2012-04-01

    Acromegaly is a disease characterized by chronic growth hormone hypersecretion. Cardiovascular complications represent the main cause of death. We present here a rare case of dilated cardiomyopathy whose diagnosis revealed an acromegaly. This will provide the opportunity to review an uncommon disease and its recently reassessed prevalence.

  10. [Cochlear implant in a patient with dilatation of the endolymphatic sac and vestibular aqueduct].

    PubMed

    Clarós, P; Sanz, J J; Clavería, M A; Costa, C; Clarós, A

    2005-03-01

    We present an 8 years patient old with a giant dilatation of the vestibular aqueduct associated with profound and progressive bilateral sensorineural hearing loss. The patient received a cochlear implant and during the surgery a pulsatile clear fluid via the cochleostomy was observed, without gusher. We present all the problems, and offer some advices for this kind of surgery.

  11. Dilated common duct sign. A potential indicator of a sphincter of Oddi dyskinesia

    SciTech Connect

    DeRidder, P.; Fink-Bennett, D.

    1984-05-01

    The cholescintigraphic findings of a Sphincter of Oddi dyskinesia (SOD) in a 45-year-old woman with persistent right upper quadrant pain and biliary colic are reported. After an overnight fast, the patient was injected with 5 mCi of Tc-99 disofenin and .02 micrograms/kg of cholecystokinin (CCK) post maximal gallbladder filling. Pre and postcholescintiscans were obtained and gallbladder ejection fractions determined. The hepatobiliary scan was normal, except for a delay in biliary-bowel transit. The gallbladder responded normally to CCK, however, the Sphincter of Oddi responded abnormally, as there was a paradoxical response to CCK manifested by a marked dilatation of the common bile duct. It was postulate that this dilatation (the dilated common duct sign) was due to an inappropriate response of the smooth muscle of the Sphincter of Oddi (contraction vs relaxation) to CCK and was the cause of this patient's biliary colic. The dilated common duct sign should alert the physician to the possibility of a Sphincter of Oddi dyskinesia.

  12. Case report: massive biliary dilatation mimicking cystic retroperitoneal masses on computed tomography.

    PubMed

    Glajchen, N; Shapiro, R S; Gendler, R; Mitty, H; Train, J S

    1993-01-01

    An unusual case is presented in which a massively dilated common bile duct produced a confusing CT image of multiple cystic areas within the abdominal cavity. Cholangiography and CT-cholangiography were useful in establishing the correct diagnosis. The differential diagnosis of cystic retroperitoneal masses is discussed.

  13. Telomere G-tail Length is a Promising Biomarker Related to White Matter Lesions and Endothelial Dysfunction in Patients With Cardiovascular Risk: A Cross-sectional Study☆

    PubMed Central

    Nezu, Tomohisa; Hosomi, Naohisa; Takahashi, Tetsuya; Anno, Kumiko; Aoki, Shiro; Shimamoto, Akira; Maruyama, Hirofumi; Hayashi, Tomonori; Matsumoto, Masayasu; Tahara, Hidetoshi

    2015-01-01

    Background The telomeric 3′-overhang (G-tail) length is essential for the biological effects of telomere dysfunction in vitro, but the association of length with aging and cardiovascular risk is unclear in humans. We investigated the association between the telomere G-tail length of leukocytes and cardiovascular risk, age-related white matter changes (ARWMCs), and endothelial function. Methods Patients with a history of cerebrovascular disease and comorbidity were enrolled (n = 102; 69 males and 33 females, 70.1 ± 9.2 years). Total telomere and telomere G-tail lengths were measured using a hybridization protection assay. Endothelial function was evaluated by ultrasound assessment of brachial flow-mediated dilation (FMD). Findings Shortened telomere G-tail length was associated with age and Framingham risk score (P = 0.018 and P = 0.012). In addition, telomere G-tail length was positively correlated with FMD values (P = 0.031) and negatively with the severity of ARWMCs (P = 0.002). On multivariate regression analysis, telomere G-tail length was independently associated with FMD values (P = 0.022) and the severity of ARWMCs (P = 0.033), whereas total telomere length was not associated with these indicators. Interpretation Telomere G-tail length is associated with age and vascular risk factors, and might be superior to total telomere length as a marker of endothelial dysfunction and ARWMC severity. PMID:26425704

  14. Vitamin C status is related to proinflammatory responses and impaired vascular endothelial function in healthy, college-aged lean and obese men.

    PubMed

    Mah, Eunice; Matos, Manuel D; Kawiecki, Diana; Ballard, Kevin; Guo, Yi; Volek, Jeff S; Bruno, Richard S

    2011-05-01

    Vitamin C supplementation has been suggested to reduce cardiovascular disease risk. However, no studies have examined the relationship between vitamin C status and vascular dysfunction in lean and obese individuals in the absence of supplementation. We examined whether vascular function is interrelated with vitamin C status and inflammation in healthy, college-aged lean and obese men with no history of dietary supplementation. A cross-sectional study was conducted during winter 2008 in lean and obese men aged 21±3 years (n=8/group). Brachial artery flow-mediated dilation (FMD) was measured to determine vascular endothelial function. Plasma antioxidants (vitamin C, vitamin E, and thiols), inflammatory proteins (C-reactive protein [CRP], myeloperoxidase [MPO], and cytokines), and cellular adhesion molecules were measured. Participants also completed 3-day food records on the days preceding their vascular testing. Group differences were evaluated by t tests, and correlation coefficients were determined by linear regression. FMD was 21% lower (P<0.05) in obese men. They also had 51% lower vitamin C intakes and 38% lower plasma vitamin C concentrations. Obese men had greater plasma concentrations of CRP, MPO, inflammatory cytokines, and cellular adhesion molecules. Participants' CRP and MPO were each inversely related (P<0.05) to FMD (r=-0.528 and -0.625) and plasma vitamin C (r=-0.646 and -0.701). These data suggest that low vitamin C status is associated with proinflammatory responses and impaired vascular function in lean and obese men. Additional study is warranted to determine whether improving dietary vitamin C intakes from food attenuate vascular dysfunction.

  15. Spontaneous Dilated Cardiomyopathy and Right-Sided Heart Failure as a Differential Diagnosis for Hepatosis Dietetica in a Production Pig

    PubMed Central

    Collins, Dalis E; Eaton, Kathryn A; Hoenerhoff, Mark J

    2015-01-01

    An experimentally naïve 37.7-kg Yorkshire-crossbred gilt died unexpectedly 2 d after arrival. Necropsy revealed severe dilated cardiomyopathy characterized grossly by markedly dilated ventricles and thinned ventricular walls and interventricular septum. Histologically there was multifocal myofiber attenuation and patchy loss of myofiber cross striations. The liver contained submassive to massive, diffuse hepatic centrilobular hemorrhage and degeneration. These lesions supported a diagnosis of dilated cardiomyopathy with right heart failure and secondary hepatic degeneration due to marked acute passive congestion. To our knowledge, this case is the first report of spontaneous dilated cardiomyopathy in swine and represents a potential diagnostic challenge regarding the differentiation of the cardiac-associated liver lesion from hepatosis dietetica. The diagnosis of dilated cardiomyopathy and right-sided heart failure was supported by the character of the hepatic lesion, absence of typical gross or histologic lesions of mulberry heart disease, and normal selenium levels. PMID:26310462

  16. Dilatancy and pore pressure effects during fracture and shear of antigorite-rich serpentinite

    NASA Astrophysics Data System (ADS)

    French, M. E.; Zhu, W.

    2015-12-01

    Geophysical observations show evidence of near-lithostatic pore pressure in fault zones that experience episodic slow slip events. In addition, dilatancy hardening is one of several hypotheses proposed to explain the transient self-sustaining nature of slow slip. Thus, pore pressure evolution is possibly an important control on slow slip behavior. Phyllosilicates are abundant in regions of subduction zones and along the deep San Andreas Fault where slow slip is observed, yet previous work on phyllosilicate-bearing rocks indicates that fracture and frictional sliding occur with little dilation of the pore space. We present experimental results of pore pressure effects during fracture and frictional shear of antigorite-rich serpentinite. Triaxial deformation experiments were conducted on intact cores 25.4 mm in diameter and 53.0 mm in length and ~1.5 mm thick gouge zones sandwiched between porous sandstone or steel sawcut forcing blocks. Experiments were conducted at room temperature, confining pressures from 50 to 100 MPa, pore pressure from 0 to 95 MPa, and axial displacement rates from 0.016 to 4.0 μm/s (shear rates from 0.02 to 5 μm/s). Foliated and macroscopically isotropic intact serpentinite samples were tested; fabric orientation is strongly correlated with both strength and dilatancy. When foliation is oriented parallel to σ1, strength and dilatancy are greatest and similar to those for crystalline rocks. When foliation is oriented 45 ° to σ1, however, dilatancy and strength are both greatly reduced. During frictional shear we observe a transition from rate-strengthening to rate-weakening behavior at ~0.5 μm/s, which is within range of typical slow slip rates and consistent with previous studies. This transition occurs concurrently with a transition from slip-induced compaction to dilation. Higher pore pressure correlates with overall higher friction coefficient, and also with lower compaction rates and higher dilation rates in the rate

  17. Primary Intraventricular Brain Abscess Resulting in Isolated Dilation of the Inferior Horn and Unilateral Hydrocephalus.

    PubMed

    Inamasu, Joji; Moriya, Shigeta; Kawazoe, Yushi; Nagahisa, Shinya; Hasegawa, Mitsuhiro; Hirose, Yuichi

    2015-01-01

    Primary intraventricular brain abscesses are rare, and there are no established treatment guidelines for this condition. We report a case in which isolated ventricular dilatation and unilateral hydrocephalus developed after seemingly successful conservative management and which required surgical diversion of the cerebrospinal fluid. A 59-year-old woman presented to our emergency department with high-grade fever and headache. Brain magnetic resonance imaging (MRI) revealed abscesses in the bilateral posterior horn. Although surgical evacuation of the abscesses was considered, conservative management with antibiotics was selected because of the paucity of severe neurological deficits and the concern that an attempt to evacuate the intraventricular abscess might lead to inadvertent rupture of the abscess capsule and acute ventriculitis. Despite reduction in the abscess volume, the patient developed an altered mental status 4 weeks after admission. Follow-up MRI revealed isolated dilation of the left inferior horn, compressing the brainstem. Emergency fenestration of the dilated inferior horn was performed, and endoscopic observation revealed an encapsulated abscess with adhesion to the ventricular wall which was thought responsible for the ventricular dilation and unilateral hydrocephalus. Two weeks after the initial surgery, the unilateral hydrocephalus was treated by placement of a ventriculoperitoneal shunt. Eradication of the intraventricular brain abscesses without surgical evacuation may justify the conservative management of this patient. However, the possibility that earlier surgical evacuation might have prevented development of the isolated ventricular dilation cannot be denied. Additional clinical experience is required to determine which treatment (surgical vs. conservative) is more appropriate in patients with primary intraventricular brain abscesses. PMID:26351446

  18. Primary Intraventricular Brain Abscess Resulting in Isolated Dilation of the Inferior Horn and Unilateral Hydrocephalus

    PubMed Central

    Inamasu, Joji; Moriya, Shigeta; Kawazoe, Yushi; Nagahisa, Shinya; Hasegawa, Mitsuhiro; Hirose, Yuichi

    2015-01-01

    Primary intraventricular brain abscesses are rare, and there are no established treatment guidelines for this condition. We report a case in which isolated ventricular dilatation and unilateral hydrocephalus developed after seemingly successful conservative management and which required surgical diversion of the cerebrospinal fluid. A 59-year-old woman presented to our emergency department with high-grade fever and headache. Brain magnetic resonance imaging (MRI) revealed abscesses in the bilateral posterior horn. Although surgical evacuation of the abscesses was considered, conservative management with antibiotics was selected because of the paucity of severe neurological deficits and the concern that an attempt to evacuate the intraventricular abscess might lead to inadvertent rupture of the abscess capsule and acute ventriculitis. Despite reduction in the abscess volume, the patient developed an altered mental status 4 weeks after admission. Follow-up MRI revealed isolated dilation of the left inferior horn, compressing the brainstem. Emergency fenestration of the dilated inferior horn was performed, and endoscopic observation revealed an encapsulated abscess with adhesion to the ventricular wall which was thought responsible for the ventricular dilation and unilateral hydrocephalus. Two weeks after the initial surgery, the unilateral hydrocephalus was treated by placement of a ventriculoperitoneal shunt. Eradication of the intraventricular brain abscesses without surgical evacuation may justify the conservative management of this patient. However, the possibility that earlier surgical evacuation might have prevented development of the isolated ventricular dilation cannot be denied. Additional clinical experience is required to determine which treatment (surgical vs. conservative) is more appropriate in patients with primary intraventricular brain abscesses. PMID:26351446

  19. Slow slip generated by dehydration reaction coupled with slip-induced dilatancy and thermal pressurization

    NASA Astrophysics Data System (ADS)

    Yamashita, Teruo; Schubnel, Alexandre

    2016-05-01

    Sustained slow slip, which is a distinctive feature of slow slip events (SSEs), is investigated theoretically, assuming a fault embedded within a fluid-saturated 1D thermo-poro-elastic medium. The object of study is specifically SSEs occurring at the down-dip edge of seismogenic zone in hot subduction zones, where mineral dehydrations (antigorite, lawsonite, chlorite, and glaucophane) are expected to occur near locations where deep slow slip events are observed. In the modeling, we introduce dehydration reactions, coupled with slip-induced dilatancy and thermal pressurization, and slip evolution is assumed to interact with fluid pressure change through Coulomb's frictional stress. Our calculations show that sustained slow slip events occur when the dehydration reaction is coupled with slip-induced dilatancy. Specifically, slow slip is favored by a low initial stress drop, an initial temperature of the medium close to that of the dehydration reaction equilibrium temperature, a low permeability, and overall negative volume change associated with the reaction (i.e., void space created by the reaction larger than the space occupied by the fluid released). Importantly, if we do not assume slip-induced dilatancy, slip is accelerated with time soon after the slip onset even if the dehydration reaction is assumed. This suggests that slow slip is sustained for a long time at hot subduction zones because dehydration reaction is coupled with slip-induced dilatancy. Such slip-induced dilatancy may occur at the down-dip edge of seismogenic zone at hot subduction zones because of repetitive occurrence of dehydration reaction there.

  20. Myocardial gene expression profiles and cardiodepressant autoantibodies predict response of patients with dilated cardiomyopathy to immunoadsorption therapy

    PubMed Central

    Ameling, Sabine; Herda, Lars R.; Hammer, Elke; Steil, Leif; Teumer, Alexander; Trimpert, Christiane; Dörr, Marcus; Kroemer, Heyo K.; Klingel, Karin; Kandolf, Reinhard; Völker, Uwe; Felix, Stephan B.

    2013-01-01

    Aims Immunoadsorption with subsequent immunoglobulin G substitution (IA/IgG) represents a novel therapeutic approach in the treatment of dilated cardiomyopathy (DCM) which leads to the improvement of left ventricular ejection fraction (LVEF). However, response to this therapeutic intervention shows wide inter-individual variability. In this pilot study, we tested the value of clinical, biochemical, and molecular parameters for the prediction of the response of patients with DCM to IA/IgG. Methods and results Forty DCM patients underwent endomyocardial biopsies (EMBs) before IA/IgG. In eight patients with normal LVEF (controls), EMBs were obtained for clinical reasons. Clinical parameters, negative inotropic activity (NIA) of antibodies on isolated rat cardiomyocytes, and gene expression profiles of EMBs were analysed. Dilated cardiomyopathy patients displaying improvement of LVEF (≥20 relative and ≥5% absolute) 6 months after IA/IgG were considered responders. Compared with non-responders (n = 16), responders (n = 24) displayed shorter disease duration (P = 0.006), smaller LV internal diameter in diastole (P = 0.019), and stronger NIA of antibodies. Antibodies obtained from controls were devoid of NIA. Myocardial gene expression patterns were different in responders and non-responders for genes of oxidative phosphorylation, mitochondrial dysfunction, hypertrophy, and ubiquitin–proteasome pathway. The integration of scores of NIA and expression levels of four genes allowed robust discrimination of responders from non-responders at baseline (BL) [sensitivity of 100% (95% CI 85.8–100%); specificity up to 100% (95% CI 79.4–100%); cut-off value: −0.28] and was superior to scores derived from antibodies, gene expression, or clinical parameters only. Conclusion Combined assessment of NIA of antibodies and gene expression patterns of DCM patients at BL predicts response to IA/IgG therapy and may enable appropriate selection of patients who benefit from this