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Sample records for flow-mediated dilation relation

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

    PubMed Central

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

    2016-01-01

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

  2. Aerobic Capacity and Postprandial Flow Mediated Dilation.

    PubMed

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

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

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

    PubMed

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

    2014-07-01

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

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

    PubMed Central

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

    2015-01-01

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

  5. 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.

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

    PubMed Central

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

    2007-01-01

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

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

    PubMed

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

    2014-12-01

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

  8. 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

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

    PubMed

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

    2007-03-01

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

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

    PubMed

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

    2016-11-23

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

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

    PubMed Central

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

    2017-01-01

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

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

    PubMed

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

    2015-01-01

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

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

    PubMed Central

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

    2014-01-01

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

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

    PubMed

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

    2013-07-01

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

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

    PubMed

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

    2016-05-01

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

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

    PubMed

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

    2016-08-01

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

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

    PubMed

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

    2016-09-01

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

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

    PubMed

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

    2016-11-01

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

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

    PubMed

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

    2016-12-15

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

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

    NASA Astrophysics Data System (ADS)

    Ikeshita, Kazuki; Hasegawa, Hideyuki; Kanai, Hiroshi

    2011-07-01

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

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

    PubMed Central

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

    2011-01-01

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

  5. 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.

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

    PubMed

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

    2017-01-01

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

  7. 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.

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

    PubMed

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

    2016-08-01

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

  9. 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.

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

    PubMed

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

    2012-12-01

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

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

    PubMed

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

    2012-06-01

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

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

    PubMed

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

    2013-05-01

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

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed Central

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

    2013-01-01

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

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

    PubMed Central

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

    2017-01-01

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

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

    PubMed

    Monahan, Kevin D

    2012-11-15

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

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

    PubMed Central

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

    2013-01-01

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

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

    PubMed

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

    2012-05-15

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

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed

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

    2013-01-01

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

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

    PubMed Central

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

    2012-01-01

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

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

    PubMed

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

    2016-11-16

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

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

    PubMed Central

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

    2016-01-01

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

  4. 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

  5. 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.

  6. 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.

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

    PubMed

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

    2003-09-19

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

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

    PubMed Central

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

    2016-01-01

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

  9. CARDIORESPIRATORY FITNESS MODULATES THE ACUTE FLOW-MEDIATED DILATION RESPONSE FOLLOWING HIGH-INTENSITY BUT NOT MODERATE-INTENSITY EXERCISE IN ELDERLY MEN.

    PubMed

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

    2017-02-16

    Impaired endothelial function is observed with ageing and with low cardiorespiratory fitness (VO2peak) whilst improvements in both are suggested to be reliant on higher-intensity exercise in the elderly. This may be due to the flow-mediated dilation (FMD) response to acute exercise of varying intensity. We examined the hypothesis that exercise-intensity alters the FMD response in healthy elderly adults, and would be modulated by VO2peak Forty-seven elderly men were stratified into lower- (VO2peak = 24.3±2.9 ml.kg(-1)min(-1), n=27) and higher-fit groups (VO2peak = 35.4±5.5 ml.kg(-1)min(-1), n=20) after a test of cycling peak power output (PPO). In randomised order, participants undertook 27 min moderate-intensity continuous (MICE; 40% PPO) or high-intensity interval cycling exercise (HIIE; 70% PPO), or no-exercise control. Brachial FMD was assessed at rest, 10 and 60 min after exercise. In control, FMD reduced in both groups (P=0.05). FMD increased after MICE in both groups [increase of 0.86 % (95% CI, 0.17 to 1.56), P=0.01], and normalised after 60 min. In the lower-fit, FMD reduced after HIIE [reduction of 0.85 % (95% CI, 0.12 to 1.58), P=0.02), and remained decreased at 60 min (P=0.05). In the higher-fit FMD was unchanged immediately after HIIE and increased after 60 min [increase of 1.52 % (95% CI, 0.41 to 2.62), P<0.01], which was correlated with VO2peak (r =0.41; P<0.01). Exercise-intensity alters the FMD response in elderly adults, and VO2peak modulates the FMD response following HIIE, but not MICE. The sustained decrease in FMD in the lower-fit may represent a signal for vascular adaptation or endothelial fatigue.

  10. Improved test of time dilation in special relativity.

    PubMed

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

    2003-11-07

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

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

    PubMed

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

    2006-10-15

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

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

    PubMed Central

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

    2010-01-01

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

  13. 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.

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

    PubMed

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

    2008-04-01

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

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

    PubMed

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

    2015-01-01

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

  16. 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…

  17. 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

  18. 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.

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

    DTIC Science & Technology

    2012-06-01

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

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

    PubMed Central

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

    1995-01-01

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

  1. 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

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

    PubMed

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

    2014-02-04

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

  3. Dilated cardiomyopathy.

    PubMed

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

    2017-02-09

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

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

    DTIC Science & Technology

    2011-06-01

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

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

    PubMed

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

    1990-05-01

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

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

    PubMed Central

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

    2016-01-01

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

  7. Measurement of Flow-Mediated Vasodilatation.

    PubMed

    Tomiyama, Hirofumi; Saisu, Tomoko; Yamashina, Akira

    2017-04-06

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

  8. Dilating Eye Drops

    MedlinePlus

    ... Frequently Asked Questions Español Condiciones Chinese Conditions Dilating Eye Drops En Español Read in Chinese What are dilating eye drops? Dilating eye drops contain medication to enlarge ( ...

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

    PubMed

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

    2014-01-01

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

  10. 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...

  11. Microstructural formulation of stress dilatancy

    NASA Astrophysics Data System (ADS)

    Wan, Richard; Guo, Peijun

    2014-03-01

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

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

    PubMed

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

    2012-11-01

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

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

    PubMed

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

    2015-04-07

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

  14. 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.

  15. Neonatal dilated cardiomyopathy.

    PubMed

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

    2017-03-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2016-03-01

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

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

    PubMed

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

    2016-03-01

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

  18. 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 ...

  19. Inflammatory dilated cardiomyopathy (DCMI).

    PubMed

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

    2005-09-01

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

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

    DTIC Science & Technology

    2013-06-01

    obsessive - compulsive behaviors (which were previously present, but have since become worse) and other anxiety-related behaviors. His parents worried that...screening questionnaire for Asperger Syndrome and other high-functioning autism spectrum disorders in school age children. Journal of Autism...Developmental Disorders , 29, 129-141. 3. Fenson, L., Marchman, V.A., Thal, D.J., Dale, P.S., Reznick, J.S., & Bates, E. (1992). MacArthur-Bates

  1. 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

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

    PubMed

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

    2017-01-01

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

  3. 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.

  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 Central

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

    2014-01-01

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

  5. Genetics of hypertrophic and dilated cardiomyopathy.

    PubMed

    Friedrich, Felix W; Carrier, Lucie

    2012-10-01

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

  6. 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.

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

    PubMed Central

    2012-01-01

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

  8. 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.

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

    PubMed

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

    1989-11-01

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

  10. 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)

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

    PubMed

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

    2016-06-01

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

  12. 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.

  13. 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.

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

    PubMed Central

    Bajd, Franci; Serša, Igor

    2013-01-01

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

  15. 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.

  16. Dilatational band formation in bone

    PubMed Central

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

    2012-01-01

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

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

    PubMed

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

    2010-01-01

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

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

    NASA Astrophysics Data System (ADS)

    Salehnia, Fatemeh; Collin, Frédéric; Charlier, Robert

    2017-03-01

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

  19. Assessment of ventricular function in dilated cardiomyopathies.

    PubMed

    Pak, P H; Kass, D A

    1995-05-01

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

  20. Time dilation in quantum systems and decoherence

    NASA Astrophysics Data System (ADS)

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

    2017-02-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2012-04-01

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

  2. 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

  3. Genetic basis of dilated cardiomyopathy.

    PubMed

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

    2016-12-01

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

  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. 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.

  6. 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

  7. 21 CFR 876.5450 - Rectal dilator.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... dilator is a device designed to dilate the anal sphincter and canal when the size of the anal opening may interfere with its function or the passage of an examining instrument. (b) Classification. Class I...

  8. Dilated cardiomyopathy and inclusion body myositis.

    PubMed

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

    2012-04-01

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

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

    PubMed Central

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

    2014-01-01

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

  10. Role of fault gouge dilatancy on aseismic deformation transients

    NASA Astrophysics Data System (ADS)

    Liu, Yajing; Rubin, Allan M.

    2010-10-01

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

  11. 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

  12. 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.

  13. 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.

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

    USGS Publications Warehouse

    Iverson, Richard M.; George, David L.

    2016-01-01

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

  15. Dilated Cardiomyopathy Induced by Chronic Starvation and Selenium Deficiency

    PubMed Central

    2016-01-01

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

  16. The pupil dilation response to visual detection

    NASA Astrophysics Data System (ADS)

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

    2008-02-01

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

  17. [Monitoring cervical dilatation by impedance].

    PubMed

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

    1992-01-01

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

  18. 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

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

    PubMed

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

    2013-01-01

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

  20. 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...

  1. 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...

  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. Intraventricular vortex properties in nonischemic dilated cardiomyopathy.

    PubMed

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

    2014-03-01

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

  4. 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

  5. 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.

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

    PubMed

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

    2012-04-24

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

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

    PubMed Central

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

    2014-01-01

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

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

    PubMed Central

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

    2012-01-01

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

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

    PubMed Central

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

    2013-01-01

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

  10. Genetic Variations Leading to Familial Dilated Cardiomyopathy.

    PubMed

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

    2016-10-01

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

  11. Genetic Variations Leading to Familial Dilated Cardiomyopathy

    PubMed Central

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

    2016-01-01

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

  12. Dilational Response of Voided Polycrystals

    NASA Astrophysics Data System (ADS)

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

    2017-02-01

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

  13. Dilated Cardiomyopathy Revealing Cushing Disease

    PubMed Central

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

    2015-01-01

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

  14. 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

  15. 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.

  16. 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...

  17. 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...

  18. 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...

  19. 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...

  20. 21 CFR 876.5365 - Esophageal dilator.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

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

  1. 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

  2. What Is a Comprehensive Dilated Eye Exam?

    MedlinePlus

    ... What is a comprehensive dilated eye exam? Healthy Vision Diabetes Diabetes Home How Much Do You Know? What You Should Know Protecting Against Vision Loss Staying on TRACK Diabetic Eye Disease FAQ ...

  3. Aortic dilatation in children with systemic hypertension.

    PubMed

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

    2014-04-01

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

  4. Aortic Dilatation in Children with Systemic Hypertension

    PubMed Central

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

    2014-01-01

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

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

    PubMed

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

    2014-10-22

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

  6. 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....

  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... Devices § 884.4260 Hygroscopic Laminaria cervical dilator. (a) Identification. A hygroscopic Laminaria cervical dilator is a device designed to dilate (stretch open) the cervical os by cervical insertion of...

  8. 21 CFR 884.4270 - Vibratory cervical dilators.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

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

  9. Genetic mutations and mechanisms in dilated cardiomyopathy.

    PubMed

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

    2013-01-01

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

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

    PubMed

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

    2013-10-01

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

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

    PubMed Central

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

    2013-01-01

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

  12. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2013-09-01

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

  14. Dilated cardiomyopathy and progressive familial intrahepatic cholestasis

    PubMed Central

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

    2014-01-01

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

  15. 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

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

    SciTech Connect

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

    1981-12-01

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

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

    PubMed

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

    2004-11-19

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

  18. 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... flexibilities. The device may include a mechanism to expand the portion of the device in the urethra...

  19. 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... flexibilities. The device may include a mechanism to expand the portion of the device in the urethra...

  20. 21 CFR 876.5520 - Urethral dilator.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

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

  1. 21 CFR 876.5520 - Urethral dilator.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

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

  2. Stability under dilations of nonlinear spinor fields

    NASA Astrophysics Data System (ADS)

    Strauss, Walter A.; Vázquez, Luis

    1986-07-01

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

  3. Stability under dilations of nonlinear spinor fields

    SciTech Connect

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

    1986-07-15

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

  4. 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...

  5. 21 CFR 874.3900 - Nasal dilator.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

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

  6. Genetics Home Reference: familial dilated cardiomyopathy

    MedlinePlus

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

  7. 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

  8. 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

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

    PubMed Central

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

    2013-01-01

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

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

    PubMed Central

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

    1990-01-01

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

  11. Sheehan syndrome with reversible dilated cardiomyopathy.

    PubMed

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

    2010-01-01

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

  12. 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.

  13. 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}=∞ : ∞ : ∞.

  14. Dilatancy Instability as a Possible Seismic Mechanism

    DTIC Science & Technology

    1976-06-01

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

  15. Improved Model of Rock Mass Dilatation.

    DTIC Science & Technology

    1985-05-29

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

  16. 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.

  17. Dilational surface rheology of polymer solutions

    NASA Astrophysics Data System (ADS)

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

    2015-06-01

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

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

    NASA Astrophysics Data System (ADS)

    Szypcio, Zenon

    2016-12-01

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

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed

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

    2015-01-01

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

  1. 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.

  2. Localization of dilatancy in Ohshima granite under constant uniaxial stress

    NASA Astrophysics Data System (ADS)

    Yanagidani, Takashi; Ehara, Shoji; Nishizawa, Osamu; Kusunose, Kinichiro; Terada, Makoto

    1985-07-01

    The localization of dilatancy during creep of Ohshima granite under uniaxial compression was observed. Hypocenters of 3933 acoustic emission (AE) events were accurately located. It was found that the mechanical behavior of Ohshima granite was controlled by the localization of microcracks. During the stage of loading up to the creep stress, which is 83% of the average short-term fracture strength, the hypocenters of AE events were randomly distributed throughout the specimen. As soon as the primary creep began, abrupt migration and clustering of AE hypocenters into several near-surface zones were observed. AE events formed volumetric concentrations. This migration and clustering strongly suggested the rapid localized development of dilatancy at the very beginning of the primary creep stage. The distribution of AE hypocenters observed in this stage was unchanged until final faulting. By the end of the primary creep stage, AE events began to concentrate into one of these clusters, while the activities of other clusters gradually decayed. This change spread broadly and continuously in time during the creep. In the most active cluster, clustering of AE events by itself gave rise to more AE events. The shape of this cluster was spheroidal with the long axis parallel to the loading axis. No evidence directly related to planar focusing of dilatancy was found. Surface strains were mapped. The axial strain distributions in the loading interval showed that the state of stress within the sample was homogeneous. A large change in both axial and circumferential strain fields occurred during the early stage of the primary creep. After this drastic change, the pattern of strain distribution remained unchanged in the subsequent stage of the creep. The accelerated increase in one of the circumferential strain gauges during the tertiary creep stage showed strongly localized deformation preceding faulting. The development of localized dilatancy identified by hypocenter locations was

  3. Long term survival effect of metoprolol in dilated cardiomyopathy

    PubMed Central

    Di, L; De Maria, R; Gavazzi, A; Gregori, D; Parolini, M; Sinagra, G; Salvatore, L; Longaro, F; Bernobich, E; Camerini, F

    1998-01-01

    Objective—To evaluate the additive effect of metoprolol treatment on long term incidence of fatal and non-fatal cardiac events in idiopathic dilated cardiomyopathy.
Design—586 patients with idiopathic dilated cardiomyopathy were prospectively enrolled in a multicentre registry and followed up for a mean (SD) of 52 (32) months. Metoprolol, carefully titrated to the maximum tolerated dose, was added to conventional heart failure treatment in 175 patients.
Results—Survival and transplant-free survival at seven years were significantly higher in the 175 metoprolol treated patients than in the remaining 411 on standard treatment (81% v 60%, p < 0.001, and 69% v 49%, p < 0.001, respectively). By multivariate analysis, metoprolol independently predicted survival and transplant-free survival (relative risk reduction values for all cause mortality and combined mortality or transplantation 51% (95% confidence interval 21% to 69%), p = 0.002, and 34% (5% to 53%), p = 0.01, respectively). New York Heart Association class, left ventricular end diastolic diameter, and pulmonary wedge pressure were also predictive. Seven year survival (80% v 62%, p = 0.004) and transplant-free survival (68% v 51%, p = 0.005) were significantly higher in 127 metoprolol treated cases than in 127 controls selected from the entire control cohort and appropriately matched. Metoprolol was associated with a 30% reduction in all cause mortality (7% to 48%, p = 0.015) and a 26% reduction in mortality or transplantation (7% to 41%, p = 0.009). 
Conclusions—The addition of metoprolol to standard heart failure treatment, including angiotensin converting enzyme inhibitors, was effective in the long term, reducing both all cause mortality and transplantation in patients with idiopathic dilated cardiomyopathy.

 Keywords: β blockade;  dilated cardiomyopathy;  heart failure PMID:9616339

  4. 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

  5. Pupil dilation reveals top-down attentional load during spatial monitoring.

    PubMed

    Lisi, Matteo; Bonato, Mario; Zorzi, Marco

    2015-12-01

    It has long been known that the diameter of human pupil enlarges with increasing effort during the execution of a task. This has been observed not only for purely mechanical effort but also for mental effort, as for example the computation of arithmetic problems with different levels of difficulty. Here we show that pupil dilation reflects changes in visuospatial awareness induced by attentional load during multi-tasking. In the single-task condition, participants had to report the position of lateralized, briefly presented, masked visual targets ("right", "left", or "both" sides). In the multitasking conditions, participants also performed additional tasks, either visual or auditory, to increase the attentional load. Sensory stimulation was kept constant across all conditions to rule out the influence of low-level factors. Results show that event-related pupil dilation strikingly increased with task demands, mirroring a concurrent decrease in visuospatial awareness. Importantly, pupil dilation significantly differed between two dual-task conditions that required to process the same number of stimuli but yielded differed levels of accuracy (difficulty). In contrast, pupil dilation did not differ between two conditions which were equally challenging but differed both in the modality of the dual task (auditory vs. visual) and in the number of stimuli to be attended. We conclude that pupil dilation genuinely reflects the top-down allocation of supramodal attentional resources.

  6. 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.

  7. Chlamydia muridarum Induction of Glandular Duct Dilation in Mice

    PubMed Central

    Sun, Xin; Yang, Zhangsheng; Zhang, Hongbo; Dai, Jin; Chen, Jianlin; Tang, Lingli; Rippentrop, Sheena; Xue, Min

    2015-01-01

    Although Chlamydia-induced hydrosalpinx in women and mice has been used as a surrogate marker for tubal infertility, the medical relevance of nontubal pathologies, such as uterine horn dilation, developed in mice following chlamydial infection remains unclear. We now report that the uterine horn dilation correlates with glandular duct dilation detected microscopically following Chlamydia muridarum infection. The dilated glandular ducts pushed the uterine horn lumen to closure or dilation and even broke through the myometrium to develop extrusion outside the uterine horn. The severity scores of uterine horn dilation observed macroscopically correlated well with the number of cross sections of the dilated glandular ducts counted under microscopy. Chlamydial infection was detected in the glandular epithelial cells, potentially leading to inflammation and dilation of the glandular ducts. Direct delivery of C. muridarum into the mouse uterus increased both uterine horn/glandular duct dilation and hydrosalpinx. However, the chlamydial plasmid, which is essential for the induction of hydrosalpinx, was not required for the induction of uterine horn/glandular duct dilation. Screening 12 strains of mice for uterine horn dilation following C. muridarum infection revealed that B10.D2, C57BL/10J, and C57BL/6J mice were most susceptible, followed by BALB/cJ and A/J mice. Deficiency in host genes involved in immune responses failed to significantly alter the C. muridarum induction of uterine horn dilation. Nevertheless, the chlamydial induction of uterine horn/glandular duct dilation may be used to evaluate plasmid-independent pathogenicity of Chlamydia in susceptible mice. PMID:25824829

  8. Dilated cerebral venous system observed in growth restricted fetuses.

    PubMed

    Baron, Joel; Mastrolia, Salvatore Andrea; Shelef, Ilan; Tirosh, Dan; Daniel-Spiegel, Etty; Hershkovitz, Reli

    2017-04-03

    The dilation of the fetal cerebral veins is a rare phenomena that may be associated to a bad obstetric outcome, and is usually connected to antenatal thrombosis of the posterior dural venous sinuses. There are several descriptions of cerebral vein distension on magnetic resonance imaging (MRI), but all of them are detected postnatally. We present herein two cases of fetal antenatal cerebral dilation of the venous system, without any association to any sign of vein thrombosis, and a systematic review of literature regarding pathogenesis, diagnosis and outcomes associated to the antenatal detection of this condition with the use of MRI. To identify potentially eligible studies, we searched PubMed, Scopus, Cochrane Library (all from inception to October 20(th), 2016) and applied no language restrictions. The electronic database search provided a total of 22843 results. After the exclusion of duplicates, manuscripts that resulted not relevant to the review based on title and abstract screening, and analysis of manuscripts eligible for full-text assessment, no papers were found related to the subject reported in the present manuscript.

  9. Viral Myocarditis and Dilated Cardiomyopathy: Etiology and Pathogenesis.

    PubMed

    Huber, Sally A

    2016-01-01

    Myocarditis is an inflammation of the myocardium which often follows microbial infections and is a significant cause of sudden unexpected death in the young (<40 years of age) and an underlying cause of dilated cardiomyopathy. Although histologically, the disease is usually associated with infiltration of the myocardium with either eosinophils or leukocytes, use of immunosuppression is controversial outside of giant cell myocarditis and has been found to be of limited value in lymphocytic myocarditis. The relatively limited response might reflect the need for host immunity to control persistent virus infection in the heart which may be the predominant cause of the chronic myocarditis and dilated cardiomyopathy. Treating the persistent virus infection with interferon-beta improved cardiac function in a clinical trial. However, classic immunosuppressive drugs, such as cyclosporine A and cyclophosphamide, are not effective against all types of immunity and experimental myocarditis models have shown that certain immunopathogenic forms of the disease are resistant to these immunosuppressive agents. Understanding the molecular mechanisms underlying the pathogenesis of this disease and the various infectious agents which can cause it will be essential for developing effective therapeutic agents.

  10. Superluminality in dilatationally invariant generalized Galileon theories

    NASA Astrophysics Data System (ADS)

    Kolevatov, R. S.

    2015-12-01

    We consider small perturbations about homogeneous backgrounds in dilatationally invariant Galileon models. The issues we address are stability (absence of ghosts and gradient instabilities) and superluminality. We show that in the Minkowski background, it is possible to construct the Lagrangian in such a way that any homogeneous Galileon background solution is stable and small perturbations about it are subluminal. On the other hand, in the case of Friedmann-Lemaitre-Robertson-Walker (FLRW) backgrounds, for any Lagrangian functions there exist homogeneous background solutions to the Galileon equation of motion and time dependence of the scale factor, such that the stability conditions are satisfied, but the Galileon perturbations propagate with superluminal speed.

  11. Development of Dilated Cardiomyopathy and Impaired Calcium Homeostasis with Cardiac-Specific Deletion of ESRRβ.

    PubMed

    Rowe, Glenn C; Asimaki, Angeliki; Graham, Evan L; Martin, Kimberly D; Margulies, Kenneth B; Das, Saumya; Saffitz, Jeffrey E; Arany, Zoltan

    2017-01-27

    Mechanisms underlying the development of Idiopathic Dilated Cardiomyopathy (DCM) remain poorly understood. Using transcription factor expression profiling, we identified estrogen-related receptor beta (ESRRβ), a member of the nuclear receptor family of transcription factors, as highly expressed in murine hearts and other highly oxidative striated muscle beds. Mice bearing cardiac-specific deletion of ESRRβ (MHC-ERRB KO) develop dilated cardiomyopathy and sudden death at approximately 10 months of age. Isolated adult cardiomyocytes from the MHC-ERRB KO mice showed an increase in calcium sensitivity and impaired cardiomyocyte contractility, which preceded echocardiographic cardiac remodeling and dysfunction by several months. Histological analyses of myocardial biopsies from patients with various cardiomyopathies revealed that ESRRβ protein is absent from the nucleus of cardiomyocytes from patients with DCM, but not other forms of cardiomyopathy (ischemic, hypertrophic and arrhythmogenic right ventricular cardiomyopathy). Taken together these observations suggest that ESRRβ is a critical component in the onset of dilated cardiomyopathy by affecting contractility and calcium balance.

  12. On the mechanism of the coronary dilator effect of serotonin in the dog.

    PubMed

    Mena, M A; Vidrio, H

    1976-03-01

    In experiments designed to determine the nature of the coronary dilator effect of serotonin the influence of intracoronary administration of the amine on coronary perfusion pressure, heart rate and ventricular contractile force was assessed in anesthetized open-chest dogs in which the left coronary artery was perfused with blood at a constant rate. Serotonin elicited dose-related decreases in coronary perfusion pressure and increases in contractile force, and lowered heart rate slightly. The dilator response was antagonized by methysergide, slightly potentiated by practolol and unaffected by reserpine. The inotropic effect was partially antagonized by methysergide and completely blocked by practolol and reserpine. It is concluded that serotonin induces coronary dilatation by direct stimulation of specific receptors that this effect is independent of the cardiac stimulation produced by the amine, and the latter response is mediated through beta1-adrenoceptors activated by released norepinephrine.

  13. Black-white differences in mortality in idiopathic dilated cardiomyopathy: the Washington, DC, dilated cardiomyopathy study.

    PubMed Central

    Coughlin, S. S.; Gottdiener, J. S.; Baughman, K. L.; Wasserman, A.; Marx, E. S.; Tefft, M. C.; Gersh, B. J.

    1994-01-01

    Racial, socioeconomic, and clinical factors were examined as predictors of survival in idiopathic dilated cardiomyopathy using cases from five Washington, DC-area hospitals. One hundred three (80.5%) of the patients were black and 25 (19.5%) were white. The black patients were less likely to have private health insurance, less educated on average, and more likely to have a household income of $15,000 or less (P < or = .05). No racial differences were found in cardiac medication usage, with the exception of beta blockers and antiarrhythmics. The cumulative survival among black patients at 12 and 24 months was 71.5% and 63.6%, respectively, as compared with 92.0% and 86.3% among whites. The 12-month survival of black patients with ventricular arrhythmias or an ejection fraction of less than 25% was particularly poor. Age, ventricular arrhythmias, ejection fraction, and cigarette usage were significant predictors of survival in univariate analysis using the proportional hazards model. The univariate association with black race was of borderline significance (P < or = .07). In multivariate analysis, age and race were statistically significant independent predictors of survival. A strong association with black race was observed with an estimated relative risk of mortality of 5.41 (P < or = .02) after adjustment for age, ejection fraction, ventricular arrhythmias, and educational attainment. Poorer survival among blacks may be caused by a greater severity of disease at the time of diagnosis or by racial differences in cardiac care, comorbid conditions, or biologic factors affecting survival. PMID:7932836

  14. 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.

  15. Pupil Dilation: A Fingerprint of Temporal Selection During the “Attentional Blink”

    PubMed Central

    Zylberberg, Ariel; Oliva, Manuel; Sigman, Mariano

    2012-01-01

    Pupil dilation indexes cognitive events of behavioral relevance, like the storage of information to memory and the deployment of attention. Yet, given the slow temporal response of the pupil dilation, it is not known from previous studies whether the pupil can index cognitive events in the short time scale of ∼100 ms. Here we measured the size of the pupil in the Attentional Blink (AB) experiment, a classic demonstration of attentional limitations in processing rapidly presented stimuli. In the AB, two targets embedded in a sequence have to be reported and the second stimulus is often missed if presented between 200 and 500 ms after the first. We show that pupil dilation can be used as a marker of cognitive processing in AB, revealing both the timing and amount of cognitive processing. Specifically, we found that in the time range where the AB is known to occur: (i) the pupil dilation was delayed, mimicking the pattern of response times in the Psychological Refractory Period (PRP) paradigm, (ii) the amplitude of the pupil was reduced relative to that of larger lags, even for correctly identified targets, and (iii) the amplitude of the pupil was smaller for missed than for correctly reported targets. These results support two-stage theories of the Attentional Blink where a second processing stage is delayed inside the interference regime, and indicate that the pupil dilation can be used as a marker of cognitive processing in the time scale of ∼100 ms. Furthermore, given the known relation between the pupil dilation and the activity of the locus coeruleus, our results also support theories that link the serial stage to the action of a specific neuromodulator, norepinephrine. PMID:22973248

  16. Dilatation balloons: polymer selection, balloon design and assembly.

    PubMed

    Crittenden, J F

    1987-01-01

    The current status of coronary dilating instruments is presented from the designer's perspective. Catheter shaft design is considered by important features, common catheter materials and types of catheter construction. Among the seven companies manufacturing balloon dilating instruments, only three types of catheter and four materials are offered. Balloon design is presented by important features and by materials selected. Performance comparisons are made between the three materials used to fabricate dilating balloons: PVC, PE and PET.

  17. 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.

  18. Physical dilatation of the nostrils lowers the thermal strain of exercising humans.

    PubMed

    White, M D; Cabanac, M

    1995-01-01

    Increased nasal air flow during exercise was examined as a possible heat loss avenue contributing to selective brain cooling in hyperthermic humans. On 2 separate days, eight subjects [mean (SE) age, 26.4 (1.2) years] exercised on a cycle ergometer in a warm room [28 (0.2) degrees C; 28 (5)% relative humidity] to induce a moderate level of hyperthermia. In one session the nostrils were physically dilatated [average dilatation 1.55 (0.17) times] and in the other they were not (control). Both sessions started with a 5-min resting period; then subjects pedaled at 60 W for 5 min, 100 W for 15 min, and 150 W for 20 min. During dilatation both tympanic temperature (Tty) and forehead skin blood flow, estimated by laser doppler velocimetry, were significantly lower than during the control exercise of 150 W. Rates of increase of Tty during the 100-W exercise were the same in both conditions; however, during the 150-W exercise with dilatated nostrils Tty increased at a rate significantly lower than during control [1.1 (0.3) degrees C.h-1 vs 1.5 (0.4) degrees C.h-1]. The change in the rate of increase of Tty between conditions was significantly correlated to the degree of nostril dilatation (r = -0.77, P = 0.02), suggesting that the lower Tty observed was due to nostril dilatation. Facial skin temperature was not significantly different between sessions. The results suggest that the nasal cavity may act as a heat exchanger in selective brain cooling of exercising humans.

  19. Dilatation and Curettage Effect on the Endometrial Thickness

    PubMed Central

    Davar, Robab; Dehghani Firouzabadi, Razieh; Chaman Ara, Kefayat

    2013-01-01

    Background Endometrial receptivity is required for successful implantation and pregnancy. Despite the remaining controversy, many studies have shown that ultrasonographic endometrial thickness can be considered as an indicator of endometrial receptivity. Objective The study objective was to investigate the effect of dilatation and curettage on the endometrial thickness. Materials and Methods Enrolled in the study were 444 patients visited in Obstetrics & Gynecology clinic of Shahid Sadoughi hospital between Jan. 2011 to Sep. 2012. Only patients whose menstrual cycle was regular were included in study. Patients with myoma, adenomyosis, endometrial polyps or other uterine anomaly, those who smoked, whose BMI was greater than 30 and who were taking medications that could affect endometrial thickness were excluded. Endometrial thickness was measured one day before evolution (n = 444) and 5-7 days after it (n = 444) using transvaginal ultrasonography. The endometrial thicknesses were correlated to the patients’ history of dilatation and curettage. Data analysis was done through SPSS software version 16 and using descriptive statistics, independent T-test and Anova. Results Endometrial thickness in patients who had 0, 1, 2, 3 and 4 D&C were 10.00 ± 0.58, 9.83 ± 0.47, 8.90 ± 0.92, 7.42 ± 0.18 and 7.40 ± 0.07, respectively one day before ovulation (spearman’s correlation coefficient = -0.33) and 10.62 ± 0.68, 9.64 ± 0.49, 8.48 ± 0.96, 6.32 ± 0.15 and 6.90 ± 0.04, respectively, 5-7 days after ovulation (spearman’s correlation coefficient = -0.66) estradiol and progesterone levels, measured in the day of 2nd ultrasonography had not statistic relation with endometrial thickness (P = 0.27 and 0.31). The relation of endometrial thickness and age was not significant (P = 0.54 and 0.06). Conclusions Dilatation and curettage has a significant effect on the endometrial thinning. PMID:24083012

  20. 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.

  1. [Cardiomyopathies. I: classification of cardiomyopathies--dilated cardiomyopathy].

    PubMed

    Schultheiss, H P; Noutsias, M; Kühl, U; Lassner, D; Gross, U; Poller, W; Pauschinger, M

    2005-11-01

    Cardiomyopathies are common causes of heart failure and sudden cardiac death. According to the WHO classification, "specific" cardiomyopathies are differentiated from "idiopathic" cardiomyopathies. Thus, this classification is primarily based on pathophysiological characteristics. The diagnostic spectrum in cardiomyopathies comprises the entire spectrum of non-invasive and invasive cardiological examination techniques. The exact verification of certain cardiomyopathies necessitates additionally investigations. For example, immunohistological and molecular biological investigations of endomyocardial biopsies may confirm inflammatory cardiomyopathy, which is often induced by viruses. Several studies have shown that specific immunomodulatory treatment options can halt the progressive course of the disease. Several gene mutations have been identified in genetic/familial dilated cardiomyopathy. First-degree relatives should be screened for early stages. Primary prevention of sudden cardiac death shows increasing superiority of the implantable defibrillator compared with pharmacological approaches (i.e. amiodarone).

  2. Time dilation in relativistic two-particle interactions

    SciTech Connect

    Shields, B. T.; Morris, M. C.; Ware, M. R.; Su, Q.; Grobe, R.; Stefanovich, E. V.

    2010-11-15

    We study the orbits of two interacting particles described by a fully relativistic classical mechanical Hamiltonian. We use two sets of initial conditions. In the first set (dynamics 1) the system's center of mass is at rest. In the second set (dynamics 2) the center of mass evolves with velocity V. If dynamics 1 is observed from a reference frame moving with velocity -V, the principle of relativity requires that all observables must be identical to those of dynamics 2 seen from the laboratory frame. Our numerical simulations demonstrate that kinematic Lorentz space-time transformations fail to transform particle observables between the two frames. This is explained as a result of the inevitable interaction dependence of the boost generator in the instant form of relativistic dynamics. Despite general inaccuracies of the Lorentz formulas, the orbital periods are correctly predicted by the Einstein's time dilation factor for all interaction strengths.

  3. Dilatancy in the flow and fracture of stretched colloidal suspensions.

    PubMed

    Smith, M I; Besseling, R; Cates, M E; Bertola, V

    2010-11-16

    Concentrated particulate suspensions, commonplace in the pharmaceutical, cosmetic and food industries, display intriguing rheology. In particular, the dramatic increase in viscosity with strain rate (shear thickening and jamming), which is often observed at high-volume fractions, is of practical and fundamental importance. Yet, manufacture of these products and their subsequent dispensing often involves flow geometries substantially different from that of simple shear flow experiments. In this study, we show that the elongation and breakage of a filament of a colloidal fluid under tensile loading is closely related to the jamming transition seen in its shear rheology. However, the modified flow geometry reveals important additional effects. Using a model system with nearly hard-core interactions, we provide evidence of surprisingly strong viscoelasticity in such a colloidal fluid under tension. With high-speed photography, we also directly observe dilatancy and granulation effects, which lead to fracture above a critical elongation rate.

  4. Developmental dilatation of Virchow-Robin spaces: a genetic disorder?

    PubMed

    Bruna, Anne-Laure; Martins, Ilda; Husson, Beatrice; Landrieu, Pierre

    2009-10-01

    In childhood, widening of Virchow-Robin spaces is rarely secondary to specific progressive disorders, but more often appears in poorly characterized developmental conditions. From data collected in a neuropediatric department, we examined whether clinical data associated with "constitutional widening of Virchow-Robin spaces" allowed delineation of recognizable entities. Signs in 10 patients, mostly boys, suggested nonspecific cerebral dysfunctions, e.g., developmental delay, nonspecific epilepsy, headaches, or benign macrocephaly. Spaces were sometimes round, subsequently mimicking microcystic malacic lesions. In two patients, abnormal magnetic resonance imaging signals were evident in white matter contiguous to widened perivascular spaces, suggesting a broader disorder of fluid exchanges. Four cases occurred in two sibships. In two families, other patients exhibited early developmental difficulties. Long-term clinical and magnetic resonance imaging surveillance will clarify which cases of primary Virchow-Robin space dilatation imply a benign prognosis. Performance of magnetic resonance imaging on any relative exhibiting minor neuropsychologic handicaps would permit estimations of real genetic incidence.

  5. Cardiac dilatation and pump dysfunction without intrinsic myocardial systolic failure following chronic beta-adrenoreceptor activation.

    PubMed

    Osadchii, Oleg E; Norton, Gavin R; McKechnie, Richard; Deftereos, Dawn; Woodiwiss, Angela J

    2007-04-01

    There is no direct evidence to indicate that pump dysfunction in a dilated chamber reflects the impact of chamber dilatation rather than the degree of intrinsic systolic failure resulting from myocardial damage. In the present study, we explored the relative roles of intrinsic myocardial systolic dysfunction and chamber dilatation as mediators of left ventricular (LV) pump dysfunction. Administration of isoproterenol, a beta-adrenoreceptor agonist, for 3 mo to rats (0.1 mg.kg(-1).day(-1)) resulted in LV pump dysfunction as evidenced by a reduced LV endocardial fractional shortening (echocardiography) and a decrease in the slope of the LV systolic pressure-volume relation (isolated heart preparations). Although chronic beta-adrenoreceptor activation induced cardiomyocyte damage (deoxynucleotidyl transferase-mediated dUTP nick-end labeling) as well as beta(1)- and beta(2)-adrenoreceptor inotropic downregulation (attenuated contractile responses to dobutamine and salbutamol), these changes failed to translate into alterations in intrinsic myocardial contractility. Indeed, LV midwall fractional shortening (echocardiography) and the slope of the LV systolic stress-strain relation (isolated heart preparations) were unchanged. A normal intrinsic myocardial systolic function, despite the presence of cardiomyocyte damage and beta-adrenoreceptor inotropic downregulation, was ascribed to marked increases in myocardial norepinephrine release, to upregulation of alpha-adrenoreceptor-mediated contractile effects as determined by phenylephrine responsiveness, and to compensatory LV hypertrophy. LV pump failure was attributed to LV dilatation, as evidenced by increased LV internal dimensions (echocardiography), and a right shift and increased volume intercept of the LV diastolic pressure-volume relation. In conclusion, chronic sympathetic stimulation, despite reducing beta-adrenoreceptor-mediated inotropic responses and promoting myocyte apoptosis, may nevertheless induce pump

  6. 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…

  7. 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

  8. 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... Devices § 884.4260 Hygroscopic Laminaria cervical dilator. (a) Identification. A hygroscopic...

  9. 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... Devices § 884.4260 Hygroscopic Laminaria cervical dilator. (a) Identification. A hygroscopic...

  10. 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... Devices § 884.4260 Hygroscopic Laminaria cervical dilator. (a) Identification. A hygroscopic...

  11. 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... Devices § 884.4260 Hygroscopic Laminaria cervical dilator. (a) Identification. A hygroscopic...

  12. Balloon catheter dilatation and thrombectomy for acute aortoiliac occlusion

    PubMed Central

    Archie, Joseph P.

    1981-01-01

    A case of acute distal aortic thrombosis in an elderly high-risk patient was successfully managed with intraoperative thrombectomy and balloon catheter dilatation of the common iliac arteries. Balloon catheter dilatation may be indicated prior to bypass grafting in high-risk patients with acute aortoiliac thrombosis. PMID:15216181

  13. Endoscopic balloon dilatation of Crohn’s-associated intestinal strictures: High patient satisfaction and long-term efficacy

    PubMed Central

    Rueda Guzmán, Anna; Wehkamp, Jan; Kirschniak, Andreas; Naumann, Aline; Malek, Nisar P.

    2016-01-01

    Introduction Stricture formation is a common long-term complication of Crohn’s disease. Endoscopic balloon dilatation offers a bowel-sparing treatment option, but long-term outcome and its association with patient-, stricture-, and procedure-related factors is only poorly understood. Patient satisfaction with endoscopic balloon dilatation is largely unknown. Methods We performed a retrospective review of all endoscopic balloon dilatation for Crohn’s disease-related strictures between January 2005 and January 2013. Long-term outcome, complication rates and predictive factors were evaluated. Patient satisfaction was assessed using a questionnaire and telephone interviews. Results A total of 118 balloon dilatations were performed for 69 strictures in 46 patients. One patient was excluded from further analysis due to malignancy. Median time from diagnosis of Crohn’s disease to symptomatic stricture formation was 19 years. Technical success, defined as passage of the endoscope after dilatation, was reportedly obtained in 95 of 106 procedures (89.6%). Two perforations occurred, one of which could be managed conservatively. No episodes of severe bleeding were recorded (procedure-related complication rate: 2/118; 1.7%). During a median follow-up of 4.8 years (range 0.4–8.7), 55.6% (25/45) of patients were able to avoid surgery. Of the patients, 35.6% (16/45) did not need any further intervention, 40.0% (18/45) underwent more than one dilatation, and 24.4% (11/45) were operated after the first dilatation. The percentage of patients who were satisfied with the procedure and would again opt for balloon dilation as first line therapy was 83.3% (35/42). None of the risk factors examined in this study correlated with the necessity for subsequent surgery. Discussion Endoscopic balloon dilatation is a safe and effective first line therapy for Crohn’s disease-related strictures. No technical, stenosis-, or patient-related factor reliably predicted sustained dilatation

  14. 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

  15. Familial dilated cardiomyopathy: A multidisciplinary entity, from basic screening to novel circulating biomarkers.

    PubMed

    de Gonzalo-Calvo, D; Quezada, M; Campuzano, O; Perez-Serra, A; Broncano, J; Ayala, R; Ramos, M; Llorente-Cortes, V; Blasco-Turrión, S; Morales, F J; Gonzalez, P; Brugada, R; Mangas, A; Toro, R

    2017-02-01

    Idiopathic dilated cardiomyopathy has become one of the most prevalent inherited cardiomyopathies over the past decades. Genetic screening of first-degree relatives has revealed that 30-50% of the cases have a familial origin. Similar to other heart diseases, familial dilated cardiomyopathy is characterized by a high genetic heterogeneity that complicates family studies. Cli'nical screening, 12-lead electrocardiogram and transthoracic echocardiogram are recommended for patients and first-degree family members. Magnetic resonance also needs to be considered. Genetic technologies have become fundamental for the clinical management of this disease. New generation sequencing methods have made genetic testing feasible for extensive panels of genes related to the disease. Recently, new imaging modalities such as speckle-tracking, strain and strain rate or magnetic resonance, and circulating biomarkers such as non-coding RNAs, have emerged as potential strategies to help cardiologists in their clinical practice. Imaging, genetic and blood-based techniques should be considered together in the evaluation and testing of familial dilated cardiomyopathy. Here, we discuss the current procedures and novel approaches for the clinical management of familial dilated cardiomyopathy.

  16. Dilation of fusion pores by crowding of SNARE proteins.

    PubMed

    Wu, Zhenyong; Bello, Oscar D; Thiyagarajan, Sathish; Auclair, Sarah Marie; Vennekate, Wensi; Krishnakumar, Shyam S; O'Shaughnessy, Ben; Karatekin, Erdem

    2017-03-27

    Hormones and neurotransmitters are released through fluctuating exocytotic fusion pores that can flicker open and shut multiple times. Cargo release and vesicle recycling depend on the fate of the pore, which may reseal or dilate irreversibly. Pore nucleation requires zippering between vesicle-associated v- and target membrane t-SNAREs, but the mechanisms governing the subsequent pore dilation are not understood. Here, we probed dilation of single fusion pores using v-SNARE-reconstituted ~23 nm diameter discoidal nanolipoprotein particles (vNLPs) as fusion partners with cells ectopically expressing cognate, 'flipped' t-SNAREs. Pore nucleation required a minimum of 2, and reached a maximum above ~4 copies per face, but the probability of pore dilation was far from saturating at 15 copies, the NLP capacity. Our experimental and computational results suggest SNARE availability may be pivotal in determining whether neurotransmitters or hormones are released through a transient (kiss & run) or an irreversibly dilating pore (full fusion).

  17. Dietary taurine deficiency and dilated cardiomyopathy in the fox.

    PubMed

    Moise, N S; Pacioretty, L M; Kallfelz, F A; Stipanuk, M H; King, J M; Gilmour, R F

    1991-02-01

    Taurine deficiency has been implicated as a potential cause of dilated cardiomyopathy. However, the relationship between taurine and myocardial function is presently unclear. The purpose of this study was to determine whether dilated cardiomyopathy in the fox is associated with dietary taurine deficiency. A total of 68 foxes from farms with a history of death caused by dilated cardiomyopathy and 14 foxes from a farm with no history of dilated cardiomyopathy were studied. Dilated cardiomyopathy was diagnosed by echocardiography in 48% of the foxes from one farm with a positive history and in none of the foxes from the control farm. Foxes less than 9 months of age were more commonly affected than older foxes (p = 0.03). Plasma taurine concentrations were significantly less (p less than 0.01) in foxes that had dilated cardiomyopathy (26.8 +/- 16.4 nmol/ml) than in the control foxes (99.3 +/- 60.2 nmol/ml). A significantly higher (p less than 0.01) incidence of dilated cardiomyopathy was present in foxes with a history of a sibling or offspring that died of dilated cardiomyopathy than in foxes without a family history of cardiac death. In one fox with dilated cardiomyopathy that was tested, the myocardial taurine concentration was lower (1.7 mumol/gm wet weight) than that of control foxes (7.3 +/- 1.6 mumol/gm wet weight). Hepatic cysteinesulfinic acid decarboxylase activity was significantly less (p less than 0.001) in foxes with dilated cardiomyopathy (0.97 +/- 0.2 nmol/mm.mg protein) than in control foxes (2.11 +/- 0.07 nmol CO2/mm.mg protein).(ABSTRACT TRUNCATED AT 250 WORDS)

  18. [Esophageal dilatation by Savary-Guillard bougies in children].

    PubMed

    Asensio Llorente, M; Broto Mangues, J; Gil-Vernet Huguet, J M; Acosta Farina, D; Marhuenda Irastorza, C; Boix-Ochoa, J

    1999-01-01

    Dilatations are considered the election treatment for esophageal stenosis of different etiologies. Different methods of dilatation have been used through the years. Security and effectiveness are the main subjects when we choose a dilatation method. We present the results of the last 3 years that Savary-Guilliard have been used, with a guide wire probe, under endoscopic control. Six patients with postsurgical stenosis and 10 with post lye ingestion stenosis were treated with the above mentioned method. The site of stenosis is localized under flexible endoscopy, and a special guide wire probe is introduced to the stomach. Once the wire is in place, different diameter bougies are introduced until a firm resistance is felt or the desired diameter is reach. In complicated cases the progression of the wire was controlled by X-rays. A total of 208 dilatations have done in 16 patients over the last three years. Six patients with postsurgical stenosis needed from two to six dilatations for their cure. Of the 10 patients who ingest lye, none of them had needed a gastrostomy. Three of them have no dysphagia after 9, 13 and 13 dilatations. The other 7 are under dilatations every 6 weeks in 6 cases and every 4 weeks in one case, been all of them in the second year of treatment. All the dilatations have been performed under general anesthesia, as outpatients. We have not had any complication under this treatment. We have found that the Savary-Guilliard method is adequate for esophageal dilatations in pediatric population. Security and effectiveness are the main points of this procedure, there is no need for a gastrostomy, and the child will have a better quality of life. This procedure is less aggressive, and this will give a shorter postop period, with no complications and the child will have a longer period of normal life between dilatations.

  19. 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

  20. Gap-flow Mediated Transport of Pollution to a Remote Coastal Site: Effects upon Aerosol Composition

    NASA Astrophysics Data System (ADS)

    Cornwell, G.; Martin, A.; Petters, M.; Prather, K. A.; Taylor, H.; Rothfuss, N.; DeMott, P. J.; Kreidenweis, S. M.

    2015-12-01

    During the CalWater 2015 field campaign, observations of aerosol size, concentration, chemical composition, and cloud activity were made at Bodega Bay, CA on the remote California coast. Strong anthropogenic influence on air quality, aerosol physicochemical properties and cloud activity was observed at Bodega Bay during periods of special meteorological conditions, known as Petaluma Gap Flow, in which air from California's interior is transported to the coast. This study utilizes single particle mass spectrometry, along with aerosol physical and chemical measurements and meteorological measurements to show that the dramatic change in aerosol properties is strongly related to regional meteorology and anthropogenically-influenced chemical processes in California's Central Valley. The change in airmass properties from those typical of a remote marine environment to properties of a continental regime has impacts on atmospheric radiative balance and cloud formation that must be accounted for in regional climate simulation.

  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. Dynamic functional modules in co-expressed protein interaction networks of dilated cardiomyopathy

    PubMed Central

    2010-01-01

    Background Molecular networks represent the backbone of molecular activity within cells and provide opportunities for understanding the mechanism of diseases. While protein-protein interaction data constitute static network maps, integration of condition-specific co-expression information provides clues to the dynamic features of these networks. Dilated cardiomyopathy is a leading cause of heart failure. Although previous studies have identified putative biomarkers or therapeutic targets for heart failure, the underlying molecular mechanism of dilated cardiomyopathy remains unclear. Results We developed a network-based comparative analysis approach that integrates protein-protein interactions with gene expression profiles and biological function annotations to reveal dynamic functional modules under different biological states. We found that hub proteins in condition-specific co-expressed protein interaction networks tended to be differentially expressed between biological states. Applying this method to a cohort of heart failure patients, we identified two functional modules that significantly emerged from the interaction networks. The dynamics of these modules between normal and disease states further suggest a potential molecular model of dilated cardiomyopathy. Conclusions We propose a novel framework to analyze the interaction networks in different biological states. It successfully reveals network modules closely related to heart failure; more importantly, these network dynamics provide new insights into the cause of dilated cardiomyopathy. The revealed molecular modules might be used as potential drug targets and provide new directions for heart failure therapy. PMID:20950417

  3. Dilatant shear band formation and diagenesis in calcareous, arkosic sandstones, Vienna Basin (Austria)

    PubMed Central

    Lommatzsch, Marco; Exner, Ulrike; Gier, Susanne; Grasemann, Bernhard

    2015-01-01

    The present study examines deformation bands in calcareous arkosic sands. The investigated units can be considered as an equivalent to the Matzen field in the Vienna Basin (Austria), which is one of the most productive oil reservoirs in central Europe. The outcrop exposes carbonate-free and carbonatic sediments of Badenian age separated by a normal fault. Carbonatic sediments in the hanging wall of the normal fault develop dilation bands with minor shear displacements (< 2 mm), whereas carbonate-free sediments in the footwall develop cataclastic shear bands with up to 70 cm displacement. The cataclastic shear bands show a permeability reduction up to 3 orders of magnitude and strong baffling effects in the vadose zone. Carbonatic dilation bands show a permeability reduction of 1-2 orders of magnitude and no baffling structures. We distinguished two types of deformation bands in the carbonatic units, which differ in deformation mechanisms, distribution and composition. Full-cemented bands form as dilation bands with an intense syn-kinematic calcite cementation, whereas the younger loose-cemented bands are dilatant shear bands cemented by patchy calcite and clay minerals. All analyzed bands are characterized by a porosity and permeability reduction caused by grain fracturing and cementation. The changed petrophysical properties and especially the porosity evolution are closely related to diagenetic processes driven by varying pore fluids in different diagenetic environments. The deformation band evolution and sealing capacity is controlled by the initial host rock composition. PMID:26300577

  4. Remote arteriolar dilations caused by methacholine: a role for CGRP sensory nerves?

    PubMed

    Thengchaisri, Naris; Rivers, Richard J

    2005-08-01

    Remote vasodilation caused by arteriolar microapplication of acetylcholine cannot be completely attributed to passive cell-cell communication of a hyperpolarizing signal. The present study was undertaken to ascertain whether a neural component may be involved in the remote response. In the cheek pouch of anesthetized hamsters, methacholine (100 microM) was applied to the arteriole by micropipette for 5 s, and the arteriolar responses were measured at the site of application and at remote locations: 500 and 1,000 microm upstream from the application site. Superfusion with the local anesthetic bupivacaine attenuated a local dilatory response and abolished the conducted dilation response to methacholine. Localized micropipette application of bupivacaine 300 microm from the methacholine application site also attenuated the remote dilation but did not inhibit the local dilation. Blockade of neuromuscular transmission with botulinum neurotoxin A (1 U, 3 days), micropipette application of calcitonin gene-related peptide (CGRP) receptor inhibitor CGRP-(8-37) (10 microM) 300 microm upstream from the methacholine application site, and denervation of the CGRP sensory nerve by 2 days of capsaicin treatment reduced the conducted dilation response to methacholine but did not affect the local dilatory response. Together, these data support involvement of a TTX-insensitive nerve, specifically the CGRP containing nerve, in vascular communication. Understanding the effect of regulation of a novel neural network system on the vascular network may lead to a new insight into regulation of blood flow and intraorgan blood distribution.

  5. Dilatant shear band formation and diagenesis in calcareous, arkosic sandstones, Vienna Basin (Austria).

    PubMed

    Lommatzsch, Marco; Exner, Ulrike; Gier, Susanne; Grasemann, Bernhard

    2015-04-01

    The present study examines deformation bands in calcareous arkosic sands. The investigated units can be considered as an equivalent to the Matzen field in the Vienna Basin (Austria), which is one of the most productive oil reservoirs in central Europe. The outcrop exposes carbonate-free and carbonatic sediments of Badenian age separated by a normal fault. Carbonatic sediments in the hanging wall of the normal fault develop dilation bands with minor shear displacements (< 2 mm), whereas carbonate-free sediments in the footwall develop cataclastic shear bands with up to 70 cm displacement. The cataclastic shear bands show a permeability reduction up to 3 orders of magnitude and strong baffling effects in the vadose zone. Carbonatic dilation bands show a permeability reduction of 1-2 orders of magnitude and no baffling structures. We distinguished two types of deformation bands in the carbonatic units, which differ in deformation mechanisms, distribution and composition. Full-cemented bands form as dilation bands with an intense syn-kinematic calcite cementation, whereas the younger loose-cemented bands are dilatant shear bands cemented by patchy calcite and clay minerals. All analyzed bands are characterized by a porosity and permeability reduction caused by grain fracturing and cementation. The changed petrophysical properties and especially the porosity evolution are closely related to diagenetic processes driven by varying pore fluids in different diagenetic environments. The deformation band evolution and sealing capacity is controlled by the initial host rock composition.

  6. Noninvasive Assessment of Pulse-Wave Velocity and Flow-Mediated Vasodilation in Anesthetized Göttingen Minipigs

    PubMed Central

    Ludvigsen, Trine P; Wiinberg, Niels; Jensen, Christina J; Callesen, Annemette T; Andersen, Regitze W; Jørgensen, Anne Sofie H; Christoffersen, Berit Ø; Pedersen, Henrik D; Moesgaard, Sophia G; Olsen, Lisbeth H

    2014-01-01

    Few methods for noninvasive assessment of arterial stiffness and endothelial dysfunction in porcine models are available. The aim of this study was to evaluate methods for assessment of arterial stiffness and endothelial dysfunction in anesthetized Göttingen minipigs. Pulse-wave velocity (PWV) was assessed in male Göttingen minipigs (n = 8; age approximately 60 wk) by using applanation tonometry of the carotid and femoral arteries. In addition, flow-mediated vasodilation (FMD) was assessed by using vascular ultrasonography of the brachial artery to evaluate endothelial dysfunction. To evaluate the reproducibility of the methods, minipigs were anesthetized by intravenous infusion of ketamine and midazolam and examined every other day for a total of 3 trials. Neither examination day nor systolic, diastolic, or mean arterial blood pressure statistically influenced PWV or FMD. The median interexamination coefficient of variation was 17% for PWV and 59% for FMD. Measured values of PWV corresponded largely to those in clinically healthy humans, but FMD values were lower than expected for lean, young animals. Although the ketamine–midazolam anesthesia we used has been associated with minor hemodynamic effects in vivo, in vitro studies suggest that both drugs are vasodilatory. Therefore anesthesia might have influenced the endothelial response, contributing to the modest FMD response and the concurrent high coefficients of variation that we noted. We conclude that PWV—but not FMD—showed acceptable interexamination variation for its potential application in porcine models. PMID:25527028

  7. Clinical diabetic cardiomyopathy: a two-faced disease with restrictive and dilated phenotypes.

    PubMed

    Seferović, Petar M; Paulus, Walter J

    2015-07-14

    Diabetes mellitus-related cardiomyopathy (DMCMP) was originally described as a dilated phenotype with eccentric left ventricular (LV) remodelling and systolic LV dysfunction. Recently however, clinical studies on DMCMP mainly describe a restrictive phenotype with concentric LV remodelling and diastolic LV dysfunction. Both phenotypes are not successive stages of DMCMP but evolve independently to respectively heart failure with preserved left ventricular ejection fraction (HFPEF) or reduced left ventricular ejection fraction (HFREF). Phenotype-specific pathophysiological mechanisms were recently proposed for LV remodelling and dysfunction in HFPEF and HFREF consisting of coronary microvascular endothelial dysfunction in HFPEF and cardiomyocyte cell death in HFREF. A similar preferential involvement of endothelial or cardiomyocyte cell compartments explains DMCMP development into distinct restrictive/HFPEF or dilated/HFREF phenotypes. Diabetes mellitus (DM)-related metabolic derangements such as hyperglycaemia, lipotoxicity, and hyperinsulinaemia favour development of DMCMP with restrictive/HFPEF phenotype, which is more prevalent in obese type 2 DM patients. In contrast, autoimmunity predisposes to a dilated/HFREF phenotype, which manifests itself more in autoimmune-prone type 1 DM patients. Finally, coronary microvascular rarefaction and advanced glycation end-products deposition are relevant to both phenotypes. Diagnosis of DMCMP requires impaired glucose metabolism and exclusion of coronary, valvular, hypertensive, or congenital heart disease and of viral, toxic, familial, or infiltrative cardiomyopathy. In addition, diagnosis of DMCMP with restrictive/HFPEF phenotype requires normal systolic LV function and diastolic LV dysfunction, whereas diagnosis of DMCMP with dilated/HFREF phenotype requires systolic LV dysfunction. Treatment of DMCMP with restrictive/HFPEF phenotype is limited to diuretics and lifestyle modification, whereas DMCMP with dilated

  8. 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

  9. Pupil Dilation to Explicit and Non-Explicit Sexual Stimuli.

    PubMed

    Watts, Tuesday M; Holmes, Luke; Savin-Williams, Ritch C; Rieger, Gerulf

    2017-01-01

    Pupil dilation to explicit sexual stimuli (footage of naked and aroused men or women) can elicit sex and sexual orientation differences in sexual response. If similar patterns were replicated with non-explicit sexual stimuli (footage of dressed men and women), then pupil dilation could be indicative of automatic sexual response in fully noninvasive designs. We examined this in 325 men and women with varied sexual orientations to determine whether dilation patterns to non-explicit sexual stimuli resembled those to explicit sexual stimuli depicting the same sex or other sex. Sexual orientation differences in pupil dilation to non-explicit sexual stimuli mirrored those to explicit sexual stimuli. However, the relationship of dilation to non-explicit sexual stimuli with dilation to corresponding explicit sexual stimuli was modest, and effect magnitudes were smaller with non-explicit sexual stimuli than explicit sexual stimuli. The prediction that sexual orientation differences in pupil dilation are larger in men than in women was confirmed with explicit sexual stimuli but not with non-explicit sexual stimuli.

  10. The dilated bowel: a liability and an asset.

    PubMed

    Bianchi, A; Morabito, A

    2009-11-01

    The gastrointestinal tract responds to significant mechanical or functional obstruction by dilatation and hypertrophy of the segment proximal to the obstruction. Excessive dilatation compromises motility, and absorption and is associated with considerable morbidity (intraluminal stasis, sepsis) such that bowel dilatation represents a major liability that predisposes the patient to intestinal failure. The dilated bowel proximal to an obstruction provides valuable autologous material for reconstruction with "tissue appropriate to the part." Bowel elongation and dilatation are integral to the natural intestinal adaptation response to loss of small bowel and can also be induced through a structured "Bowel Expansion" program. The additional absorptive tissue that is progressively generated is essential for reconstruction of the bowel (tailoring and lengthening), to restore gastrointestinal dynamics (effective propulsion and absorption), and to reduce morbidity (intraluminal stasis, sepsis). In enhancing the prospects for enteral autonomy, dilatation and elongation of the residual autologous bowel are crucial to long-term survival and good quality life, and represent a most welcome asset. This paper reviews the impact and management of bowel dilatation along the gastrointestinal tract.

  11. Dilated cardiomyopathy update: infectious-immune theory revisited.

    PubMed

    Kawai, Chuichi; Matsumori, Akira

    2013-11-01

    Dilated cardiomyopathy is characterized by dilatation of the left or right ventricle, or both ventricles. The degree of myocardial dysfunction is not attributable to abnormal loading conditions. The infectious-immune theory has long been hypothesized to explain the pathogenesis of many etiologically unrecognized dilated cardiomyopathies. Inflammations followed by immune reactions, which may be excessive, in the myocardium, evoked by external triggers such as viral infections and/or autoimmune antibodies, continue insidiously, and lead to the process of cardiac remodeling with ventricular dilatation and systolic dysfunction. This ultimately results in dilated cardiomyopathy. Hepatitis C virus-associated heart diseases are good examples of cardiac lesions definitely induced by viral infections in humans that progress to a chronic stage through complicated immune mechanisms. Therapeutic strategies for myocarditis and dilated cardiomyopathy have been obtained through analyses of the acute, subacute, and chronic phases of experimental viral myocarditis in mice. The appropriate modulation of excessive immune reactions during myocarditis, rather than their complete elimination, appears to be a key option in the prevention and treatment of dilated cardiomyopathy. The clinical application of an NF-κB decoy and immune adsorption of IgG3 cardiac autoantibodies have been used as immunomodulating therapies and may provide novel approaches for the treatment of refractory patients with dilated cardiomyopathy. Conventional therapeutic agents for chronic heart failure such as β-blockers, angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, and aldosterone antagonists in particular should be re-evaluated on the basis of their anti-inflammatory properties in the treatment of dilated cardiomyopathy.

  12. C-Reactive protein in dilated cardiomyopathy.

    PubMed

    Kaneko, K; Kanda, T; Yamauchi, Y; Hasegawa, A; Iwasaki, T; Arai, M; Suzuki, T; Kobayashi, I; Nagai, R

    1999-01-01

    The prognosis for patients with idiopathic dilated cardiomyopathy (DCM) is poor, although clinical features are variable. Prediction of outcome has been difficult in individual patients based on laboratory data. In some patients with DCM, myocardial damage secondary to viral or immune-mediated myocardial inflammation may persist. To objectively assess inflammation, we measured plasma concentrations of C-reactive protein (CRP) in 188 patients with idiopathic DCM over 5-8 years. All had dyspnea and fatigue at rest; all patients had a left ventricular ejection fraction less than 40% by echocardiography or by contrast or radionuclide ventriculography. We divided these patients into two groups: patients dying within 5 years following admission (n = 49) and the remainder surviving for at least 5 years (n = 139). CRP concentrations in the patients dying early were significantly higher than in the long-term survivors (1. 05 +/- 1.37 vs. 0.49 +/- 1.04 mg/dl, p < 0.05). Sixty-two percent of the patients with CRP>1.0 died within 5 years. In addition to other laboratory tests including electrocardiography and echocardiography, routine CRP measurements proved to be valuable for identifying high-risk patients who require special treatment strategies.

  13. Statistical analysis with dilatation for development process of human fetuses.

    PubMed

    Naito, Kanta; Notsu, Akifumi; Udagawa, Jun; Otani, Hiroki

    2017-02-01

    This paper is concerned with the development process of human fetuses. Though the development process of human fetuses still includes many unknown issues, it is known that a certain harmonious relationship between the organs can be observed. This knowledge is based on our intuition, but we have no theory which clarifies these harmonized developments. The paper aims to give a mathematical understanding of the notion of harmonized development through the use of dilatation, which is a measure of the departure from conformal mapping. The asymptotics for dilatation have been developed using certain efficient models of quasiconformal mapping. The proposed method of dilatation is effectively applied to the human fetus data.

  14. Automated detection of dilated capillaries on optical coherence tomography angiography

    PubMed Central

    Dongye, Changlei; Zhang, Miao; Hwang, Thomas S.; Wang, Jie; Gao, Simon S.; Liu, Liang; Huang, David; Wilson, David J.; Jia, Yali

    2017-01-01

    Automated detection and grading of angiographic high-risk features in diabetic retinopathy can potentially enhance screening and clinical care. We have previously identified capillary dilation in angiograms of the deep plexus in optical coherence tomography angiography as a feature associated with severe diabetic retinopathy. In this study, we present an automated algorithm that uses hybrid contrast to distinguish angiograms with dilated capillaries from healthy controls and then applies saliency measurement to map the extent of the dilated capillary networks. The proposed algorithm agreed well with human grading. PMID:28271005

  15. Dilatation of the Lower Cervical Esophagus in a Cow

    PubMed Central

    Kasari, T. R.

    1984-01-01

    Acquired megaesophagus of suspected neuromuscular origin was diagnosed in a six year old Holstein cow. The dilatation was restricted to the lower cervical esophagus. Signs included projectile regurgitation of chewed ingesta at variable periods of time after swallowing, nasal discharge of mucus and feed particles, and a cough. A secondary aspiration pneumonia was associated with this condition. The dilated portion of the esophagus was detected utilizing positive contrast radiography and fiberoptic endoscopy. Treatment consisted of feed management and antibiotics. Deglutition in the cow returned to normal over a three month period despite radiographic and fiberoptic endoscopic evidence of a persistent dilatation of the esophagus. ImagesFigure 1. PMID:17422388

  16. 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.

  17. Lorentz-violating dilatations in momentum space and some extensions on nonlinear actions of Lorentz-algebra-preserving systems

    SciTech Connect

    Bernardini, A. E.; Rocha, R. da

    2007-03-15

    We work on some general extensions of the formalism for theories which preserve the relativity of inertial frames with a nonlinear action of the Lorentz transformations on momentum space. Relativistic particle models invariant under the corresponding deformed symmetries are presented with particular emphasis on deformed dilatation transformations. The algebraic transformations relating the deformed symmetries with the usual (undeformed) ones are provided in order to preserve the Lorentz algebra. Two distinct cases are considered: a deformed dilatation transformation with a spacelike preferred direction and a very special relativity embedding with a lightlike preferred direction. In both analysis we consider the possibility of introducing quantum deformations of the corresponding symmetries such that the spacetime coordinates can be reconstructed and the particular form of the real space-momentum commutator remains covariant. Eventually feasible experiments, for which the nonlinear Lorentz dilatation effects here pointed out may be detectable, are suggested.

  18. 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

  19. Interaction of pepsin-[C16mim]Br system: interfacial dilational rheology and conformational studies.

    PubMed

    Huang, Tian; Cao, Chong; Liu, Zi-lin; Li, Yang; Du, Feng-pei

    2014-09-21

    The interfacial rheological property is closely related to the stabilities of foams and emulsions, yet there have been limited studies on the interaction between proteins with ionic liquid-type imidazolium surfactants at the decane-water interface as well as in the bulk. Herein, we investigated the interfacial and bulk properties of pepsin (PEP) and an ionic liquid (IL), 1-hexadecyl-3-methylimidazolium bromide, [C(16)mim]Br. The interfacial pressure and dilational rheology studies were performed to describe the formation of [C(16)mim]Br-pepsin complexes. The influence of the oscillating frequency and the bulk concentration of [C(16)mim]Br on the dilational properties were explored. The conformational changes were studied by monitoring the fluorescence and far UV-CD spectra. The results reveal that the globular structure of pepsin is one of the decisive factors controlling the nature of the interfacial film. The monotonous increase in the dilational elastic modulus of pepsin-[C(16)mim]Br solutions with the surface age indicates that no loops and tails had formed. Interestingly, with an increase in the concentration of [C(16)mim]Br, the εd-c curve first passes through a plateau value due to steric hindrance and the electrostatic barrier of already absorbed tenacious pepsin-[C(16)mim]Br complexes. With the further addition of [C(16)mim]Br, the remarkable decrease in dilational elastic modulus indicates that the compact structure is destroyed gradually. The results of the fluorescence spectra and far UV-CD spectra confirm that [C(16)mim]Br did not produce perceptible changes in pepsin at the concentrations studied in the dilational experiment. Possible schematic programs of the pepsin-[C(16)mim]Br interaction model at the interface and in bulk phase are proposed.

  20. Comparison of mortality rates and progression of left ventricular dysfunction in patients with idiopathic dilated cardiomyopathy and dilated versus nondilated right ventricular cavities.

    PubMed

    Sun, J P; James, K B; Yang, X S; Solankhi, N; Shah, M S; Arheart, K L; Thomas, J D; Stewart, W J

    1997-12-15

    This study assesses the influence of right ventricular (RV) dilation on the progression of left ventricular (LV) dysfunction and survival in patients with idiopathic dilated cardiomyopathy (IDC). Using transthoracic echocardiography, we studied 100 patients with IDC aged 20 to 80 years (mean 55 +/- 14); 67% were men. In the apical 4-chamber view, diastolic LV and RV chamber area measurements classified patients into 2 groups: group RV enlargement+ (RV area/LV area > 0.5) included 54 patients; group RV enlargement- (no RV enlargement) had RV area/LV area < or = 0.5. Echocardiographic studies were repeated in all patients after a mean of 33 +/- 16 months. At the time of the initial study, the 2 groups did not differ in age, gender, incidence of atrial fibrillation and diabetes, left ventricular mass, and LV ejection fraction, but the RV enlargement+ group had more severe tricuspid regurgitation and less LV enlargement. After 47 +/- 22 months (range 12 to 96), patients in group RV enlargement+ had lower LV ejection fraction (29% vs 34%, p = 0.006) than patients with initial RV enlargement-. At clinical follow-up, mortality was higher (43%) in patients with initial RV enlargement+ than the RV enlargement- patients (15%), p = 0.002. For survivors, the mitral deceleration time averaged 157 +/- 36 ms; for nonsurvivors or patients who required transplant, the mitral deceleration time averaged 97 +/- 12 ms (p < 0.0001). With use of a multivariate Cox model adjusting for LV ejection fraction, LV size, and age, the relative risk ratio of mortality from initial RV enlargement+ was 4.4 (95% confidence limits 1.7 to 11.1) (p = 0.002). Thus, patients with significant RV dilation had nearly triple the mortality over 4 years and more rapidly deteriorating LV function than patients with less initial RV dilation. In IDC, RV enlargement is a strong marker for adverse prognosis that may represent a different morphologic subset.

  1. Treatment of colonic anastomotic strictures with 'through the scope' balloon dilators.

    PubMed Central

    Dinneen, M D; Motson, R W

    1991-01-01

    Stricture occurs in 1.2-4.2% of colonic anastomoses. Symptomatic strictures have previously been treated by resection and re-anastomosis and more recently by radiographically guided dilatation by a modified Seldinger technique. This paper describes the endoscopic balloon dilatation of five symptomatic cases and three asymptomatic cases. Eight patients underwent balloon dilatation of colonic anastomotic strictures. Four patients had no symptoms post dilatation and the strictures remained patient on follow-up endoscopy. All the remaining patients required re-dilatation at approximately 2 months. One of these patients underwent dilatation but remained symptomatic, the dilatation was repeated and a colonic perforation occurred at this time. Of the other three, two continue to be followed up, and are well and one patient died of disseminated malignancy. Balloon dilatation with 'through the scope' dilators is a simpler technique than radiologically guided dilatation. These early results suggest that endoscopic dilatation may avoid further surgery in some patients with anastomotic stricture. PMID:2041001

  2. Osmotic self-expanding dilation technology for treatment of sinusitis: the Vent-Os sinus dilation system.

    PubMed

    Catalano, Peter; Hester, Jerome; Mandrusov, Evgenia

    2015-01-01

    The Vent-Os Sinus Dilation System is an osmotically driven device that provides a means to access the sinus space and to dilate the maxillary sinus ostia and associated spaces in adults for diagnostic and therapeutic procedures. Unlike balloon dilation devices that use rapid, high-pressure inflation, this self-expanding device is designed to gently and gradually open the maxillary ostia. The procedure can be safely and easily completed in-office with minimal anesthetics and analgesics on board. Clinical results support excellent patency and safety outcomes with the use of this product in patients with chronic rhinosinusitis.

  3. Perceptual and not physical eye contact elicits pupillary dilation.

    PubMed

    Honma, Motoyasu; Tanaka, Yasuto; Osada, Yoshihisa; Kuriyama, Kenichi

    2012-01-01

    Eye contact is important to share communication during social interactions. However, how accurately humans can perceive the gaze direction of others toward themselves and whether pupils dilate when humans consciously or unconsciously perceive own eyes are looked by others remain unclear. In this study, we examined the relationship between the explicit perception of looking into each other's eyes and the implicit physiological response of pupillary dilation by using an original face-to-face method. We found that humans do not correctly detect the gaze direction of others. Furthermore, one's pupils dilated when one gazed at others' eyes. Awareness of others' gaze on one's eyes, rather than the actual focusing of other's gaze on one's eyes, enhanced pupillary dilation. Therefore, physiological responses are caused not when people actually look into each other's gaze, but when the consciousness of other's gaze is activated, which suggests that eye contact often involves one-way communication.

  4. Dilated hearts at high altitude: words from on high.

    PubMed

    Lankford, Harvey V; Swenson, Erik R

    2014-12-01

    From the time of the turn of the twentieth century, dilated hearts and presumed cardiac fatigue in expeditionary climbers and scientists have been the subject of much commentary in the medical and mountaineering literature. Although largely attributed by most, but not all, to left heart strain, the description of dilated hearts in these accounts is clearly that of right heart dilation as a consequence of high and sustained hypoxic pulmonary vasoconstriction with hypertensive remodeling. This essay will feature quotations from the writings of high altitude pioneers about dilated, strained, or enlarged hearts. It will give some brief physiology of the right side of the heart as background, but will focus on the words of mountaineers and mountaineering physicians as color commentary.

  5. Flow-mediated vasodilation as a predictor of therapeutic response to midodrine hydrochloride in children with postural orthostatic tachycardia syndrome.

    PubMed

    Liao, Ying; Yang, Jinyan; Zhang, Fengwen; Chen, Stella; Liu, Xueqin; Zhang, Qingyou; Ai, Yi; Wang, Yuli; Tang, Chaoshu; Du, Junbao; Jin, Hongfang

    2013-09-15

    This study was designed to explore the value of flow-mediated vasodilation (FMD) as a predictor of therapeutic response to midodrine hydrochloride (MD) in children with postural orthostatic tachycardia syndrome (POTS). One hundred and eight children diagnosed with POTS and 20 healthy control children were enrolled. All children with POTS received MD and were followed up for 3 months. FMD of brachial artery for each participant was measured by vascular ultrasound. Symptom scores, FMD values, and head-up test (HUT)/head-up tilt test (HUTT) outcomes were investigated before and after treatment. A receiver operating characteristic curve was used to explore the value of FMD as a predictor. Baseline FMD (%) and increased heart rate (beats per minute) during HUT/HUTT were significantly greater in children with POTS compared with control children (FMD: 11 ± 3% vs 6 ± 2%, p <0.001; increased heart rate: 38 ± 9 vs 7 ± 7 beats/min, p <0.001, respectively). Before treatment, MD responders had greater FMD values than MD nonresponders (p <0.05). Symptom scores, excessive increases in heart rate during HUT, and increased FMD values were all reduced significantly after treatment (all p <0.05). The receiver operating characteristic curve for the predictive value of FMD showed the area under the curve to be 0.790 (95% confidence interval: 0.679 to 0.902; p <0.001) at 1-month and 0.803 (95% confidence interval: 0.669 to 0.936; p <0.01) at 3-month therapy. FMD of 9.85% had a high sensitivity (1-month therapy: 71.6%; 3-month therapy: 74.4%) and specificity (1-month therapy 77.8%; 3-month therapy: 80%). In conclusion, FMD is a predictor of the efficacy of MD for treating children with POTS.

  6. Flow-Mediated Vasodilatation and Intima-Media Thickness in Patients with Coexisting Heart Failure and Diabetes Receiving Medical Therapy

    PubMed Central

    Andersen, Lisbeth Vestergaard; Wiinberg, Niels; Tuxen, Christian; Kjær, Andreas

    2011-01-01

    Objective Intensive medical treatment of heart failure (HF) patients with diabetes may reduce the endothelial dysfunction and the accelerated atherosclerotic process seen in these patients. To study this, we investigated the endothelial function and the presence of atherosclerosis as measured by flow-mediated vasodilatation (FMD) and intima-media thickness (IMT) in intensively treated patients with coexisting HF and diabetes. Research Design and Method FMD of the brachial artery and IMT of the common carotid arteries were determined in 26 patients with systolic HF and diabetes who were in intensive medical therapy, as well as in 19 healthy controls. The two groups were matched according to age and sex. In all subjects left ventricular ejection fraction was measured by two-dimensional echocardiography. Biochemical parameters including serum cholesterol, HDL and LDL, triglyceride, glucose, hemoglobin/hemoglobin-A1C (HbA1C), brain natriuretic peptide (BNP) and N-terminal pro-BNP were also assessed. Results Mean FMD and IMT did not differ significantly between patients and controls. Left ventricular ejection fraction was lower in patients compared to controls (P < 0.001). The patients had a higher mean BNP, NT pro-BNP, triglyceride, HbA1C and glucose in comparison to controls. Cholesterol, HDL-cholesterol and LDL-cholesterol were lower in patients compared to controls. Conclusions Intensively treated patients with coexisting systolic HF and diabetes seem to have normal endothelial function as measured by FMD and they have no sign of accelerated atherosclerosis as measured by IMT. This suggests a positive effect of medication on the cardiovascular alterations in this group of patients. PMID:26859486

  7. Effects of barnidipine in comparison with hydrochlorothiazide on endothelial function, as assessed by flow mediated vasodilatation in hypertensive patients.

    PubMed

    Muiesan, Maria Lorenza; Salvetti, Massimo; Belotti, Eugenia; Paini, Anna; Rosei, Claudia Agabiti; Aggiusti, Carlo; Scotti, Aurelio; de Ciuceis, Carolina; Rizzoni, Damiano; Rosei, Enrico Agabiti

    2011-08-01

    BACKGROUND. In hypertensive patients, endothelial dysfunction is associated with an increased incidence of cardiovascular events. Calcium-channel antagonists can reverse impaired endothelium-dependent vasodilation in different vascular districts, while conflicting results are found in the brachial artery. Aim. To investigate the effect of barnidipine in comparison with hydrochlorothiazide on endothelial function of hypertensives, as assessed by flow-mediated vasodilation (FMD) of the brachial artery. METHODS. Patients with mild to moderate hypertension (age range 26-67 years) were randomized to receive barnidipine or hydrochlorothiazide. A thorough clinical examination, including blood pressure (BP) measurement, was performed at randomization as well as after 6, 12 and 24 weeks. FMD and 24-h BP monitoring was performed at randomization, after 12 and 24 weeks. RESULTS. After 12 and 24 weeks of treatment, a significant reduction in clinic BP was observed in both groups. Furthermore, a significant reduction in 24-h SBP and DBP was observed in patients receiving barnidipine but not in those receiving diuretic. The percentage change in FMD was different between the two groups of patients treated with barnidipine (at 12 weeks +1.2 ± 2.2%, p = 0.023 and at 24 weeks +1.25 ± 3.15%, p = 0.16 from baseline) or with hydrochlorothiazide (at 12 weeks -1.0 ± 3.0. p = 0.09 and at 24 weeks -1.78 ± 2.9%, p = 0.015 from baseline). A significant difference in FMD changes between the two groups was confirmed by analysis of covariance (p = 0.031). CONCLUSIONS. In presence of a similar clinic BP reduction, an improvement of endothelial function was observed during treatment with barnidipine but not with hydrochlorothiazide, suggesting that the barnidipine may exert a favourable effect on endothelial dysfunction in hypertensive patients.

  8. Dilated cardiomyopathy: a preventable presentation of DiGeorge Syndrome.

    PubMed

    Jamieson, A; Smith, C J

    2015-01-01

    Patients with cardiac failure require careful evaluation to determine the precise nature of the cause of their illness. Genetic causes of dilated cardiomyopathy are well known but inherited conditions may lead to unexpected consequences through intermediate mechanisms not readily recognised as a feature of the inherited disorder. We describe a case of dilated cardiomyopathy resulting from prolonged hypocalcaemia due to previously undiagnosed hypoparathyroidism resulting from DiGeorge Syndrome and describe the features of this case and the treatment of hypoparathyroidism.

  9. Clinical and echocardiographic determinants in bicuspid aortic dilatation

    PubMed Central

    Peeters, Frederique E.C.M.; Van der Linden, Noreen; Thomassen, Alissa L.L.; Crijns, Harry J.G.M.; Meex, Steven J.R.; Kietselaer, Bas L.J.H.

    2016-01-01

    Abstract Bicuspid aortic valve (BAV) disease is associated with aortic dilatation. Timing of follow-up and surgery is challenging. Hence, there is an unmet clinical need for additional risk stratification. It is unclear whether valve morphology is associated with dilatation rates. Therefore, the objective of this study was to examine the association between clinical and echocardiographic determinants (including valve morphology) and aortic dimension and the progression rate of dilatation. Aortic dimensions were assessed on serial echocardiographic images between 1999 and 2014 in a population of 392 patients with BAVs in a tertiary care center in the Netherlands. Analyses using mixed linear models were performed. Mean age of participants was 48 ± 17 years and 69% were male. BAV morphology was associated with aortic dimensions, as well as age, sex, BSA, and valvular dysfunction. Tubular ascending aorta, sinus of Valsalva, and sinotubular junction showed a dilatation rate of 0.32, 0.18, and 0.06 mm/year, respectively. Dilatation rate was not associated with valve morphology. In the present study, there is no association between BAV morphology and aortic dilatation rates. Therefore, morphology is of limited use in prediction of aortic growth. Discovering fast progressors remains challenging. PMID:28033264

  10. 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.

  11. Clinical implications of anti-cardiac immunity in dilated cardiomyopathy.

    PubMed

    Caforio, A L P; Mahon, N G; McKenna, W J

    2006-01-01

    Criteria of organ-specific autoimmunity are fulfilled in a subset of patients with myocarditis/dilated cardiomyopathy (DCM). In particular, circulating heart-reactive autoantibodies are found in such patients and symptom-free relatives. These autoantibodies are directed against multiple antigens, some of which are expressed in the heart (organ-specific), others in heart and some skeletal muscle fibres (partially heart-specific) or in heart and skeletal muscle (muscle-specific). Distinct autoantibodies have different frequency in disease and normal controls. Different techniques detect one or more antibodies, thus they cannot be used interchangeably for screening. It is unknown whether the same patients produce more antibodies or different patient groups develop autoimmunity to distinct antigens. IgG antibodies, shown to be cardiac- and disease-specific for myocarditis/DCM, can be used as autoimmune markers for relatives at risk as well as for identifying patients in whom immunosuppression may be beneficial. Some autoantibodies may also have a functional role, but further work is needed.

  12. Spectral dilation of L(B,H)-valued measures and its application to stationary dilation for Banach space valued processes

    NASA Technical Reports Server (NTRS)

    Miamee, A. G.

    1989-01-01

    Let B be a Banach space and H and K to Hilbert spaces. The spectral dilation of L(B,H)-valued measures is studied and it is shown that the recent results of Makagon and Salehi (1986) and Rosenberg (1982) on the dilation of L(K,H)-valued measures can be extended to hold for the general Banach space setting of L(B,H)-valued measures. These L(B,H)-valued measures are closely connected to the Banach space valued processes. This connection is recalled and as application of spectral dilation of L(B,H)-valued measures the well known stationary dilation results for scalar valued processes is extended to the case of Banach space valued processes.

  13. Spectral dilation of L(B,H)-valued measures and its application to stationary dilation for Banach space valued processes

    NASA Technical Reports Server (NTRS)

    Miamee, A. G.

    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.

  14. Outcomes of esophageal dilation in eosinophilic esophagitis: Safety, efficacy, and persistence of the fibrostenotic phenotype

    PubMed Central

    Runge, Thomas M.; Eluri, Swathi; Cotton, Cary; Burk, Caitlin M.; Woosley, John T.; Shaheen, Nicholas J.; Dellon, Evan S.

    2016-01-01

    Objectives Esophageal dilation is commonly performed in eosinophilic esophagitis (EoE), but there are few long-term data. The aims of this study were to assess the safety and long-term efficacy of esophageal dilation in a large cohort of EoE cases and determine the frequency and predictors of requiring multiple dilations. Methods We conducted a retrospective cohort study in the University of North Carolina EoE clinicopathological database from 2002-2014. Included subjects met consensus diagnostic criteria for EoE. Clinical, endoscopic, and histologic features were extracted, as were dilation characteristics (dilator type, change in esophageal caliber, total number of dilations) and complications. Patients with EoE who had undergone dilation were compared to those who did not and also stratified by whether they required single or multiple dilations. Results Of 509 EoE patients, 164 were dilated a total of 486 times. Those who underwent dilation had a longer duration of symptoms prior to diagnosis (11.1 vs. 5.4 yrs, p<0.001). 95 patients (58%) required >1 dilation (417 dilations total, mean of 4.4 ± 4.3 per patient). The only predictor of requiring multiple dilations was a smaller baseline esophageal diameter. Dilation was tolerated well, with no major bleeds, perforations, or deaths. The overall complication rate was 5%, primarily due to post-procedural pain. Of 164 individuals dilated, a majority (58%, or 95/164) required a second dilation. Of these individuals, 75% required dilation within 1 year. Conclusions Dilation in EoE is well-tolerated, with a very low risk of serious complications. Patients with long-standing symptoms prior to diagnosis are likely to require dilation. More than half of those dilated will require multiple dilations, often needing a second procedure within one year. These findings can be used to counsel patients with fibrostenotic complications of EoE. PMID:26753894

  15. Complications of percutaneous transhepatic biliary drainage in patients with dilated and nondilated intrahepatic bile ducts.

    PubMed

    Weber, Andreas; Gaa, Jochen; Rosca, Bogdan; Born, Peter; Neu, Bruno; Schmid, Roland M; Prinz, Christian

    2009-12-01

    Percutaneous transhepatic biliary drainage (PTBD) have been described as an effective technique to obtain biliary access. Between January 1996 and December 2006, a total of 419 consecutive patients with endoscopically inaccessible bile ducts underwent PTBD. The current retrospective study evaluated success and complication rates of this invasive technique. PTBD was successful in 410/419 patients (97%). The success rate was equal in patients with dilated and nondilated bile ducts (p=0.820). In 39/419 patients (9%) procedure related complications could be observed. Major complications occurred in 17/419 patients (4%). Patients with nondilated intrahepatic bile ducts had significantly higher complication rates compared to patients with dilated intrahepatic bile ducts (14.5% vs. 6.9%, respectively [p=0.022]). Procedure related deaths were observed in 3 patients (0.7%). In conclusion, percutaneous transhepatic biliary drainage is an effective procedure in patients with dilated and nondilated intrahepatic bile ducts. However, patients with nondilated intrahepatic bile ducts showed a higher risk for procedure related complications.

  16. Dilation Behavior of Thermal Spray Coatings

    NASA Astrophysics Data System (ADS)

    Bejarano Lopez, Miryan Lorena

    Thermal Spray (TS) is a very versatile manufacturing process to deposit thick coatings on a variety of substrates. Coatings are used in protective (i.e. wear, chemical attack, high temperature, etc.) and functional (i.e. sensors) applications. TS coatings have a unique lamellar microstructure as a result of the overlapping of millions of molten and partially-molten particles. During processing, high deformation by impact, high temperature, and rapid solidification lead to a complex hierarchical material system that contains a high amount of microstructural defects. The presence of defects in the microstructure contribute to differences in property values in comparison to bulk materials. Thermal stresses and residual strains arise from processing, thermal gradients and thermal exposure. Evaluation of thermal properties, in this case, the coefficient of thermal expansion (CTE) is of vital importance to enhance coating performance. In this dissertation, expansion measurements of various metals, alloys, ceramics, and cermet coatings; were carried out using various techniques (push rod dilatometry, x-ray diffraction XRD, digital image correlation DIC, and curvature method) to determine the dilation behavior at the atomic, micro- and macro-scale levels. The main results were. 1) Mathematical models (Turner and Kerner) used for composite materials, successfully predicted the CTE property of a TS coating where the primary phase is the coating material and the secondary phases can be oxides, precipitates, etc. (formed as a byproduct of the spraying process). CTE was found not to be affected by porosity. 2) Despite the anisotropic behavior characteristic of TS coatings, the experimental results shown that CTE results to be reasonable isotropic within the scope of this study. 3) The curvature method was found to be an alternative technique to obtain the CTE, as well as the Young's modulus of coating in a bi-material strip, with good approximation. 4) An anomalous expansion

  17. Endoluminal dilatation for embedded hemodialysis catheters: A case-control study of factors associated with embedding and clinical outcomes

    PubMed Central

    Talreja, Hari; Ryan, Stephen Edward; Graham, Janet; Sood, Manish M.; Hadziomerovic, Adnan; Clark, Edward

    2017-01-01

    Background With the increasing frequency of tunneled hemodialysis catheter use there is a parallel increase in the need for removal and/or exchange. A small but significant minority of catheters become embedded or ‘stuck’ and cannot be removed by traditional means. Management of embedded catheters involves cutting the catheter, burying the retained fragment with a subsequent increased risk of infections and thrombosis. Endoluminal dilatation may provide a potential safe and effective technique for removing embedded catheters, however, to date, there is a paucity of data. Objectives 1) To determine factors associated with catheters becoming embedded and 2) to determine outcomes associated with endoluminal dilatation Methods All patients with endoluminal dilatation for embedded catheters at our institution since Jan. 2010 were included. Patients who had an embedded catheter were matched 1:3 with patients with uncomplicated catheter removal. Baseline patient and catheter characteristics were compared. Outcomes included procedural success and procedure-related infection. Logistic regression models were used to determine factors associated with embedded catheters. Results We matched 15 cases of embedded tunneled catheters with 45 controls. Among patients with embedded catheters, there were no complications with endoluminal dilatation. Factors independently associated with embedded catheters included catheter dwell time (> 2 years) and history of central venous stenosis. Conclusion Embedded catheters can be successfully managed by endoluminal dilatation with minimal complications and factors associated with embedding include dwell times > 2 years and/or with a history of central venous stenosis. PMID:28346468

  18. 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.

  19. Treatment of Ureterointestinal Anastomotic Strictures by Diathermal or Cryoplastic Dilatation

    SciTech Connect

    Orsi, Franco; Penco, Silvia Matei, Victor; Bonomo, Guido; Vigna, Paolo Della; Monfardini, Lorenzo; Cobelli, Ottavio De

    2007-09-15

    Background. Ureterointestinal anastomotic strictures (UAS) complicate 10-15% of surgeries for urinary diversion and are the main cause of deterioration in renal function. Treatments are surgical revision, management with autostatic stent, balloon dilatation, endoscopic incision, and percutaneous transrenal diathermy (Acucise). A new option is cryoplastic dilatation (Polar-Cath). Purpose. To assess the feasibility, complications, and preliminary results of UAS treatment using the Acucise and Polar-Cath systems. Methods. Nineteen UAS, diagnosed by ultrasonography or computed tomography and sequential renal scintigraphy, occurred in 15 cancer patients after radical cystectomy and urinary diversion. Fifteen were managed with balloon diathermy and 4 by balloon cryoplasty in a three-stage procedure-percutaneous nephrostomy, diathermal or cryoplastic dilatation, and transnephrostomic control with nephrostomy removal-each separated by 15 days. All patients gave written informed consent. Results. Dilatations were successful in all cases. The procedure is simple and rapid (about 45 min) under fluoroscopic control and sedation. Procedural complications occurred in 1 (5%) patient with UAS after Wallace II uretero-ileocutaneostomy: a common iliac artery lesion was induced by diathermal dilatation, evident subsequently, and required surgical repair. Patency with balloon diathermy was good, with two restenoses developing over 12 months (range 1-22) of follow-up. With balloon cryoplastic dilatation, one restenosis developed in the short term; follow-up is too brief to assess the long-term efficacy. Conclusion. Our short-term results with diathermal and cryoplastic dilatation to resolve UAS are good. If supported by longer follow-up, the techniques may be considered as first-choice approaches to UAS. Surgery should be reserved for cases in which this minimally invasive technique fails.

  20. [Pneumatic dilatation of achalasia: local experience in treating 41 patients].

    PubMed

    Honein, Khalil; Slim, Rita; Yaghi, César; Kheir, Bahaa; Bou Jaoudé, Joseph; Sayegh, Raymond

    2007-01-01

    L'achalasia is the best known primary motor disorder of the esophagus in which the lower esophageal sphincter (LES) has abnormally high resting pressure and incomplete relaxation with swallowing. Pneumatic dilatation (PD) remains the first choice of treatment. Our aim was to report, in a retrospective way, our experience in treating with pneumatic dilatation 41 achalasia patients admitted to the gastroenterology unit at Hôtel-Dieu de France (HDF) hospital between 1994 and 2004. A total of 46 dilatations were performed in 41 patients with achalasia [20 males and 21 females, the mean age was 46.8 years (range, 15-90)]. All patients underwent an initial dilatation by inflating a 35 mm balloon to 7 psi three times successively under fluoroscopic control. The need for subsequent dilatation with the same technique or for surgical treatment was based on symptom assessment. The mean follow-up period was 36.7 months (3 mo-7 years). Among the patients whose follow-up information was available, a satisfactory result was achieved in 29 patients (80.5%) after only one or two sessions of pneumatic dilatation. Esophageal perforation as a short-term complication was observed in one patient (2.17%). Seven patients were referred for surgery (one for esophageal perforation and six for persistent or recurrent symptoms). In conclusion, performing balloon dilatation under fluoroscopic observation is simple, safe and efficacious for treating patients with achalasia. Referral to repeated PD or to surgical myotomy should be discussed in case of no response to a first session of PD.

  1. 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

  2. In vivo vascular wall tissue characterization using a strain tensor measuring (STM) technique for flow-mediated vasodilation analyses

    NASA Astrophysics Data System (ADS)

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

    2009-10-01

    Endothelial dysfunction is considered to be a key factor in the development of atherosclerosis, and the measurement of flow-mediated vasodilation (FMD) in brachial and other conduit arteries has become a common method to assess the status of endothelial function in vivo. Based on the direct relationship between the FMD response and local shear stress on the conduit brachial artery endothelium, we hypothesize that measuring relevant changes in the brachial wall strain tensor would provide a non-invasive tool for assessing vascular mechanics during post-occlusion reactive hyperemia. Direct measurement of the wall strain tensor due to FMD has not yet been reported in the literature. In this work, a noninvasive direct ultrasound-based strain tensor measuring (STM) technique is presented to assess changes in the mechanical parameters of the vascular wall during post-occlusion reactive hyperemia and/or FMD, including local velocities and displacements, diameter change, local strain tensor and strain rates. The STM technique utilizes sequences of B-mode ultrasound images as its input with no extra hardware requirement, and its algorithm starts with segmenting a region of interest within the artery and providing the acquisition parameters. Then a block matching technique based on speckle tracking is employed to measure the frame-to-frame local velocities. Displacements, diameter change, local strain tensor and strain rates are then calculated by integrating or differentiating velocity components. The accuracy of the STM algorithm was assessed in vitro using phantom studies, where an average error of 7% was reported using different displacement ranging from 100 µm to 1000 µm. Furthermore, in vivo studies using human subjects were performed to test the STM algorithm during pre- and post-occlusion. Good correlations (|r| >0.5, P < 0.05) were found between the post-occlusion responses of diameter change and local wall strains. Results indicate the validity and versatility of

  3. 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.

  4. 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.

  5. 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

  6. 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.

  7. Clinical Effect of Endoscopic Pneumatic Dilation for Achalasia.

    PubMed

    Cheng, Peng; Shi, Hai; Zhang, Yanjie; Zhou, Huabang; Dong, Jinhua; Cai, Yiting; Hu, Xing; Dai, Qiang; Yang, Wenyan

    2015-07-01

    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. These

  8. 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

  9. 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

  10. Urethral Dilatation in Women: Urologists' Practice Patterns in the UK

    PubMed Central

    Masarani, M; Willis, RG

    2006-01-01

    INTRODUCTION Review of the literature reveals little evidence to prove the efficacy of urethral dilatation for adult women with various lower urinary tract complaints. We conducted a postal survey to ascertain the actual practice of urethral dilatation among urologists in the UK. MATERIALS AND METHODS A questionnaire was mailed to 428 consultant urologists listed as full members of the British Association of Urological Surgeons. The questionnaire consisted of 8 items about urologists' perception of indications, efficacy, and the need for repeated dilatation and anaesthesia. RESULTS The questionnaire response rate was 42%. Although urethral stenosis was the most common indication (97%), the majority of urologists (69%) indicated that fewer than 25% of patients had evidence of stenosis. Overall, 61% of urologists performed dilatation 7 times or more during the last year and 55% believed that less than half of the patients experienced long-term improvement. CONCLUSIONS Despite the lack of strong evidence to support the use of urethral dilatation in women, many urologists continue to find it a useful tool in approaching women with lower urinary tract complaints. PMID:17002859

  11. Relationships between tissue dilatation and differentiation in distraction osteogenesis.

    PubMed

    Morgan, Elise F; Longaker, Michael T; Carter, Dennis R

    2006-03-01

    Mechanical factors modulate the morphogenesis and regeneration of mesenchymally derived tissues via processes mediated by the extracellular matrix (ECM). In distraction osteogenesis, large volumes of new bone are created through discrete applications of tensile displacement across an osteotomy gap. Although many studies have characterized the matrix, cellular and molecular biology of distraction osteogenesis, little is known about relationships between these biological phenomena and the local physical cues generated by distraction. Accordingly, the goal of this study was to characterize the local physical environment created within the osteotomy gap during long bone distraction osteogenesis. Using a computational approach, we quantified spatial and temporal profiles of three previously identified mechanical stimuli for tissue differentiation-pressure, tensile strain and fluid flow-as well as another candidate stimulus-tissue dilatation (volumetric strain). Whereas pressure and fluid velocity throughout the regenerate decayed to less than 31% of initial values within 20 min following distraction, tissue dilatation increased with time, reaching steady state values as high as 43% strain. This dilatation created large reductions and large gradients in cell and ECM densities. When combined with previous findings regarding the effects of strain and of cell and ECM densities on cell migration, proliferation and differentiation, these results indicate two mechanisms by which tissue dilatation may be a key stimulus for bone regeneration: (1) stretching of cells and (2) altering cell and ECM densities. These results are used to suggest experiments that can provide a more mechanistic understanding of the role of tissue dilatation in bone regeneration.

  12. Apoptosis in Endomyocardial Biopsies from Patients with Dilated Cardiomyopathy.

    PubMed

    Glumac, S; Pejić, S; Kostadinovic, S; Stojšić, Z; Vasiljevic, J

    2016-01-01

    Apoptosis is an active energy-consuming mechanism of cell death, which may contribute to heart failure in patients with dilated cardiomyopathy. Dilated cardiomyopathy is a common clinical outcome of many prolonged cardiac insults, and therefore is considered as the most prevalent form of cardiomyopathy. Loss of heart mass is highly correlated with the heart failure and mortality, thus the purpose of this study was to define the apoptotic index in patients with dilated cardiomyopathy. Apoptosis was detected by the TUNEL method in 30 patients. Biopsies were obtained from the left ventricle, and at least three specimens were taken. TUNEL-positive cardiomyocytes were found in 26 of 30 cases (86.7 %) and the mean apoptotic index for the entire specimen series was 5.41 ± 1.70 %. The analysis showed that patients with dilated cardiomyopathy had significantly higher apoptotic index (P < 0.001) than healthy subjects. One subject (man, 41 years old) had a markedly elevated apoptotic index of 52.2 %. In the remaining subjects, the percentage of cardiomyocyte death ranged from 0 % to 15.5 %. The high percentage of apoptosis found in our study may be in accordance with the clinically manifested cardiac failure in patients with dilated cardiomyopathy since in most patients we recorded the left ventricular ejection fraction values below 30 %.

  13. Time Dilation: Flash Based Interactive Story For College, Pre-college, And Public Education

    NASA Astrophysics Data System (ADS)

    Kang, Eun-Young; Lollar, I.; Armitage, P.; Perreault, S.; Shitanishi, J.; Shvarts, E.; Wells, D.; Longson, T.; Mijic, M.; State LA SciVi Project, Cal

    2009-05-01

    Concepts of Einstein's Theory of Relativity are usually considered complicated enough that in the context of public science education they are often stated but seldom explained. In our game-like interactive animated story we explain the effect of Time Dilation in the Special Theory of Relativity by pushing to the limit a real life question: can Relativity help two students in love who want the same but in a different amount of time? The user is guided to the answer with the help of a familiar looking character. This interactive story can be used in variety of educational environments.

  14. 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.

  15. Negative pressure in shear thickening band of a dilatant fluid

    NASA Astrophysics Data System (ADS)

    Nagahiro, Shin-ichiro; Nakanishi, Hiizu

    2016-12-01

    We perform experiments and numerical simulations to investigate spatial distribution of pressure in a sheared dilatant fluid of the Taylor-Couette flow under a constant external shear stress. In a certain range of shear stress, the flow undergoes the shear thickening oscillation around 20 Hz. We find that, during the oscillation, a localized thickened band rotates around the axis with the flow. Based upon experiments and numerical simulations, we show that a major part of the thickened band is under negative pressure even in the case of discontinuous shear thickening, which indicates that the thickening is caused by Reynolds dilatancy; the dilatancy causes the negative pressure in interstitial fluid, which generates contact structure in the granular medium, then frictional resistance hinders rearrangement of the structure and solidifies the medium.

  16. 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.

  17. A Tension-Based Model Distinguishes Hypertrophic versus Dilated Cardiomyopathy.

    PubMed

    Davis, Jennifer; Davis, L Craig; Correll, Robert N; Makarewich, Catherine A; Schwanekamp, Jennifer A; Moussavi-Harami, Farid; Wang, Dan; York, Allen J; Wu, Haodi; Houser, Steven R; Seidman, Christine E; Seidman, Jonathan G; Regnier, Michael; Metzger, Joseph M; Wu, Joseph C; Molkentin, Jeffery D

    2016-05-19

    The heart either hypertrophies or dilates in response to familial mutations in genes encoding sarcomeric proteins, which are responsible for contraction and pumping. These mutations typically alter calcium-dependent tension generation within the sarcomeres, but how this translates into the spectrum of hypertrophic versus dilated cardiomyopathy is unknown. By generating a series of cardiac-specific mouse models that permit the systematic tuning of sarcomeric tension generation and calcium fluxing, we identify a significant relationship between the magnitude of tension developed over time and heart growth. When formulated into a computational model, the integral of myofilament tension development predicts hypertrophic and dilated cardiomyopathies in mice associated with essentially any sarcomeric gene mutations, but also accurately predicts human cardiac phenotypes from data generated in induced-pluripotent-stem-cell-derived myocytes from familial cardiomyopathy patients. This tension-based model also has the potential to inform pharmacologic treatment options in cardiomyopathy patients.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. Follow up study of 70 patients with renal artery stenosis treated by percutaneous transluminal dilatation.

    PubMed Central

    Geyskes, G G; Puylaert, C B; Oei, H Y; Mees, E J

    1983-01-01

    Between April 1978 and April 1981, 70 patients with hypertension and renal artery stenosis were treated by percutaneous transluminal arterial dilatation. Selection of the patients was based solely on arteriographic criteria. Arteriography after dilatation showed considerable widening of the stenosed area in all patients. In 65 patients the effect of treatment on the blood pressure was assessed during follow up periods of one to four years. In 14 of these patients the hypertension was cured, in 29 it was improved, and in 22 there was no change. Patients with fibromuscular lesions benefited distinctly more than did those with atheromatous stenosis, only one of the 21 patients with fibromuscular lesions showing no change as compared with 21 of the 44 patients with atheromatous lesions. The only serious complication encountered was microcholesterol emboli, which developed in two patients with severe atheromatous lesions of the aorta. In the atheromatous group age and overall renal function had no influence on the blood pressure response. In the subgroup of patients with a unilateral lesion the renal vein renin ratios and asymmetrical curves obtained by renography had only a very limited predictive value. In experienced hands percutaneous transluminal arterial dilatation is relatively safe, and this study suggests that it should be attempted in all patients with renal artery stenosis. Only in patients with severe atheromatosis of the aorta should the risk associated with the catheterisation be weighed against the 50% or so chance of benefit from the procedure. PMID:6223685

  3. Transient interfacial tension and dilatational rheology of diffuse polymer-polymer interfaces

    NASA Astrophysics Data System (ADS)

    Peters, Gerrit W. M.; Zdravkov, Alexander N.; Meijer, Han E. H.

    2005-03-01

    We demonstrate the influence of molecular weight and molecular weight asymmetry across an interface on the transient behavior of the interfacial tension. The interfacial tension was measured as a function of time for a range of polymer combinations with a broad range of interfacial properties using a pendant/sessile drop apparatus. The results show that neglecting mutual solubility, assumed to be a reasonable approximation in many cases, very often does not sustain. Instead, a diffuse interface layer develops in time with a corresponding transient interfacial tension. Depending on the specific combination of polymers, the transient interfacial tension is found to increase or decrease with time. The results are interpreted in terms of a recently proposed model [Shi et al., Macromolecules 37, 1591 (2004)], giving relative characteristic diffusion time scales in terms of molecular weight, molecular weight distribution, and viscosities. However, the time scales obtained from this theoretical approach do not give a conclusive trend. Using oscillatory dilatational interfacial experiments the viscoelastic behavior of these diffusive interfaces is demonstrated. The time evolution of the interfacial tension and the dilatational elasticity show the same trend as predicted by the theory of diffuse interfaces, supporting the idea that the polymer combinations under consideration indeed form diffuse interfaces. The dilatational elasticity and the dilatational viscosity show a frequency dependency that is described qualitatively by a simple Fickian diffusion model and quantitatively by a Maxwell model. The characteristic diffusion times provided by the latter show that the systems with thick interfaces (tens of microseconds and more) can be considered as slower diffusive systems compared to the systems with thinner interfaces (a few micrometers in thickness and less) can be considered as fast diffusive systems.

  4. Using surface deformation to infer reservoir dilation induced by injection

    NASA Astrophysics Data System (ADS)

    Nanayakkara, Asanga Sanjeewee

    Reservoir dilations occur due to variety of subsurface injection operations including waste disposal, waterflooding, steam injection, CO 2 sequestration and aquifer storage recovery. These reservoir dilations propagate to the surrounding formations and extend up to the ground surface resulting in surface deformations. The surface deformations can be measured by using various technologies such as tiltmeters and interferometric synthetic aperture radar (InSAR) and they can be inverted to infer reservoir dilations by solving an ill-posed inverse problem. This concept forms the basis of the research work presented in this thesis. Initially, the characteristics of the surface and subsurface deformations (induced by the injection operations) and correlations between them were investigated in detail by applying both analytical (based on center of dilatation approach) and numerical methods (fully coupled finite element method). Then, a simple set of guidelines to obtain quick estimates for the surface heave characteristics were proposed. The guidelines are in the form of simple analytical equations or charts and thereby they could be very useful in obtaining preliminary assessment for the surface deformation characteristics induced by the subsurface injection operations. Next, the mathematical aspects of the inverse problem were discussed in detail and the factors affecting the accuracy of the inverse solution were investigated through an extensive parametric study including both two-dimensional and three-dimensional problems. Then, a method was developed to infer reservoir dilation (with high accuracy and high spatial resolution) using a limited number of surface deformation measurements. The proposed method was applied to infer the reservoir dilation induced by a waste disposal operation conducted at Frog Lake, Alberta and the practical issues pertaining to the proposed method were discussed. Finally, guidelines for tiltmeter array design were proposed and

  5. 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.

  6. 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

  7. 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

  8. 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

  9. Slip and Dilation Tendency Anlysis of Neal Hot Springs 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

  10. A new method for measurement of liquid dilatation parameters

    NASA Astrophysics Data System (ADS)

    Ondris, Lubomír; Rusina, Viktor

    1997-04-01

    A new user-friendly method for measuring dilatation parameters of non-volatile liquids, based on an optoelectronic hydrolevelling sensor, is described. The system is capable of measuring a liquid column height with an accuracy of about 0957-0233/8/4/004/img1 and allows determination of the temperature dilatation volume coefficient for transparent liquids with an accuracy that depends on the used thermometer accuracy. The method is also suitable for specific mass or density measurements with an accuracy comparable to that obtained with the pycnometric method.

  11. Balloon dilation of congenital supravalvular pulmonic stenosis in a dog

    PubMed Central

    Treseder, Julia R.

    2017-01-01

    Percutaneous balloon valvuloplasty is considered the standard of care for treatment of valvular pulmonic stenosis, a common congenital defect in dogs. Supravalvular pulmonic stenosis is a rare form of pulmonic stenosis in dogs and standard treatment has not been established. Although, there have been reports of successful treatment of supravalvular pulmonic stenosis with surgical and stenting techniques, there have been no reports of balloon dilation to treat dogs with this condition. Here, a case of supravalvular pulmonic stenosis diagnosed echocardiographically and angiographically in which a significant reduction in pressure gradient was achieved with balloon dilation alone is presented. PMID:27297421

  12. Dilated cardiomyopathy after electrical injury: report of two cases.

    PubMed

    Buono, Lee M; DePace, Nicholas L; Elbaum, David M

    2003-05-01

    The specific etiologic factor and pathogenesis of most dilated cardiomyopathies have yet to be described definitively. Hypotheses of the etiologic factor of idiopathic dilated cardiomyopathy (DCM) abound. This report describes two patients with electrical injury in whom DCM developed after the electrical insult in the absence of other precipitating causes. Further histologic examination of myocardial tissue after electrical injury may reveal clues regarding the pathophysiology behind electrically induced DCM. Because electrical injury may be associated with myocardial dysfunction, short- and long-term evaluation of left ventricular function may be warranted.

  13. 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

  14. Effect of carvedilol and nebivolol on oxidative stress-related parameters and endothelial function in patients with essential hypertension.

    PubMed

    Zepeda, Ramiro J; Castillo, Rodrigo; Rodrigo, Ramón; Prieto, Juan C; Aramburu, Ivonne; Brugere, Solange; Galdames, Katia; Noriega, Viviana; Miranda, Hugo F

    2012-11-01

    Oxidative stress and endothelial dysfunction have been associated with essential hypertension (EH) mechanisms. The purpose of this study was to evaluate the effect of carvedilol and nebivolol on the oxidative stress-related parameters and endothelial function in patients with EH. The studied population included 57 patients, either sex, between 30 and 75 years of age, with mild-to-moderate EH complications. Participants were randomized to receive either carvedilol (12.5 mg) (n = 23) or nebivolol (5 mg) (n = 21) for 12 weeks. Measurements included; 24-hr ambulatory blood pressure (BP), flow-mediated dilatation, levels of nitric oxide estimated as nitrite - a nitric oxide metabolite ( NO₂) - in plasma, and oxidative stress-related parameters in plasma and erythrocyte. EH patients who were treated with nebivolol or carvedilol showed systolic BP reductions of 17.4 and 19.9 mmHg, respectively, compared with baseline values (p < 0.01). Diastolic BP was reduced by 13.7 and 12.8 mmHg after the treatment with ebivolol and carvedilol, respectively (p < 0.01) (fig. 2B). Nebivolol and carvedilol showed 7.3% and 8.1% higher endothelium-dependent dilatation in relation to baseline values (p < 0.05). Ferric-reducing ability of plasma (FRAP) and reduced glutathione/oxidized glutathione (GSSH) ratio showed 31.5% and 29.6% higher levels in the carvedilol group compared with basal values; however, nebivolol-treated patients did not show significant differences after treatment. On the other hand, the NO₂ plasma concentration was not modified by the administration of carvedilol. However, nebivolol enhanced these levels in 62.1% after the treatment. In conclusion, this study demonstrated the antihypertensive effect of both beta-blockers. However, carvedilol could mediate these effects by an increase in antioxidant capacity and nebivolol through the raise in NO₂ concentration. Further studies are needed to determine the molecular mechanism of these effects.

  15. 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.

  16. Thrombus formation in a dilated torcula following aneurysmal subarachnoid haemorrhage.

    PubMed

    Haynes, H R; Visca, A; Renowden, S; Malcolm, G

    2013-08-01

    A case of thrombus formation occurring within a dilation of the dural venous sinuses following aneurysmal sub-arachnoid haemorrhage is presented. Acute neurological deterioration accompanied propagation of the thrombus. The patient was anticoagulated on day 5 post-SAH with no haemorrhagic complications and made a full recovery. The optimum time to commence anticoagulation is not clear and is discussed.

  17. 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

  18. Cystic Dilatation of the Parotid Duct of a Goat

    PubMed Central

    Slocombe, R. F.

    1980-01-01

    Cystic dilatation of the parotid duct of a goat was diagnosed by exploratory surgery and analysis of cyst contents. The cyst and its associated salivary gland were surgically removed. This case is compared with the more common salivary mucocele. ImagesFigure 1. PMID:7397617

  19. Operative balloon dilatation for pulmonary atresia with intact ventricular septum.

    PubMed Central

    Hamilton, J R; Fonseka, S F; Wilson, N; Dickinson, D F; Walker, D R

    1987-01-01

    In six infants with pulmonary atresia and intact ventricular septum operative balloon dilatation was used to achieve continuity between the right ventricle and the main pulmonary artery as the initial procedure. Two of the six subsequently needed an aortico pulmonary shunt. All six are alive and well. Images Fig PMID:3676024

  20. 21 CFR 884.4270 - Vibratory cervical dilators.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Vibratory cervical dilators. 884.4270 Section 884.4270 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... used to gain access to the uterus or to induce abortion, but is not to be used during labor when...

  1. 21 CFR 884.4270 - Vibratory cervical dilators.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Vibratory cervical dilators. 884.4270 Section 884.4270 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... used to gain access to the uterus or to induce abortion, but is not to be used during labor when...

  2. 21 CFR 884.4270 - Vibratory cervical dilators.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Vibratory cervical dilators. 884.4270 Section 884.4270 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... used to gain access to the uterus or to induce abortion, but is not to be used during labor when...

  3. 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... used to gain access to the uterus or to induce abortion, but is not to be used during labor when...

  4. Novel Borna Virus in Psittacine Birds with Proventricular Dilatation Disease

    PubMed Central

    Honkavuori, Kirsi S.; Shivaprasad, H.L.; Williams, Brent L.; Quan, Phenix-Lan; Hornig, Mady; Street, Craig; Palacios, Gustavo; Hutchison, Stephen K.; Franca, Monique; Egholm, Michael; Lipkin, W. Ian

    2008-01-01

    Pyrosequencing of cDNA from brains of parrots with proventricular dilatation disease (PDD), an unexplained fatal inflammatory central, autonomic, and peripheral nervous system disease, showed 2 strains of a novel Borna virus. Real-time PCR confirmed virus presence in brain, proventriculus, and adrenal gland of 3 birds with PDD but not in 4 unaffected birds. PMID:19046511

  5. Linkage of familial dilated cardiomyopathy to chromosome 9

    SciTech Connect

    Krajinovic, M.; Vatta, M.; Milasin, J.

    1995-10-01

    Idiopathic dilated cardiomyopathy is a heart muscle disease of unknown etiology, characterized by impaired myocardial contractility and ventricular dilatation. The disorder is an important cause of morbidity and mortality and represents the chief indication for heart transplantation. Familial transmission is often recognized (familial dilated cardiomyopathy, or FDC), mostly with autosomal dominant inheritance. In order to understand the molecular genetic basis of the disease, a large six-generation kindred with autosomal dominant FDC was studied for linkage analysis. A genome-wide search was undertaken after a large series of candidate genes were excluded and was then extended to two other families with autosomal dominant pattern of transmission and identical clinical features. Coinheritance of the disease gene was excluded for >95% of the genome, after 251 polymorphic markers were analyzed. Linkage was found for chromosome 9q13-q22, with a maximum multipoint lod score of 4.2. There was no evidence of heterogeneity. The FDC locus was placed in the interval between loci D9S153 and D9S152. Several candidate genes for causing dilated cardiomyopathy map in this region. 33 refs., 3 figs., 1 tab.

  6. Aneurysmal dilatation of medium caliber arteries in Turner syndrome.

    PubMed

    Polkampally, Pritam R; Matta, Jatin R; McAreavey, Dorothea; Bakalov, Vladimir; Bondy, Carolyn A; Gharib, Ahmed M

    2011-01-01

    Turner syndrome is the most common chromosomal abnormality in female subjects, affecting 1 in 2000 live births. The condition is associated with a generalized vasculopathy as well as congenital cardiac and other defects. We report aneurysmal dilation of medium caliber arteries involving the celiac axis and coronary vessels in two women with Turner syndrome.

  7. 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.

  8. Left coronary aneurysmal dilation and subaortic stenosis in a dog.

    PubMed

    Hernandez, Juan L; Bélanger, Marie-Claude; Benoit-Biancamano, Marie-Odile; Girard, Christiane; Pibarot, Philippe

    2008-06-01

    A 6-month-old German shepherd dog was referred for evaluation of a cardiac murmur. Upon physical examination, the auscultated heart rate was 120 beats/min, and a grade IV/VI systolic heart murmur with a point of maximal intensity over the left heart base radiating up the neck was heard. The standard echocardiographic examination showed subaortic stenosis and an anechoic tubular structure extending from the sinus of Valsalva to the left ventricular posterior wall. Aneurysmal left coronary artery (CA) was confirmed by angiography. The dog was euthanized and post-mortem examination showed severe dilatation of the proximal left CA and confirmed the subaortic stenosis. Histopathology did not demonstrate abnormalities in the walls of the CA, aorta or pulmonary artery. The exact cause of the CA aneurysmal dilation remains unknown. Subaortic stenosis, elevated coronary vascular resistance or a congenital anomaly may have contributed to the dilation. To our knowledge, coronary aneurysmal dilation has never been described in dogs. Standard echocardiography provides reliable information on coronary anatomy.

  9. Excessive urinary tract dilatation and proteinuria in pregnancy: a common and overlooked association?

    PubMed Central

    2013-01-01

    Background Proteinuria and dilatation of the urinary tract are both relatively common in pregnancy, the latter with a spectrum of symptoms, from none to severe pain and infection. Proteinuria is a rare occurrence in acute obstructive nephropathy; it has been reported in pregnancy, where it may pose a challenging differential diagnosis with pre-eclampsia. The aim of the present study is to report on the incidence of proteinuria (≥0.3; ≥0.5 g/day) in association with symptomatic-severe urinary tract dilatation in pregnancy. Methods Case series. Setting: Nephrological-Obstetric Unit dedicated to pregnancy and kidney diseases (January 2000-April 2011). Source: database prospectively updated since the start of the Unit. Retrospective review of clinical charts identified as relevant on the database, by a nephrologist and an obstetrician. Results From January 2000 to April 2011, 262 pregnancies were referred. Urinary tract dilatation with or without infection was the main cause of referral in 26 cases (predominantly monolateral in 19 cases): 23 singletons, 1 lost to follow-up, 1 twin and 1 triplet. Patients were referred for urinary tract infection (15 cases) and/or renal pain (10 cases); 6 patients were treated by urologic interventions (“JJ” stenting). Among them, 11 singletons and 1 triple pregnancy developed proteinuria ≥0.3 g/day (46.1%). Proteinuria was ≥0.5 g/day in 6 singletons (23.1%). Proteinuria resolved after delivery in all cases. No patient developed hypertension; in none was an alternative cause of proteinuria evident. No significant demographic difference was observed in patients with renal dilatation who developed proteinuria versus those who did not. An association with the presence of “JJ” stenting was present (5/6 cases with proteinuria ≥0.5 g/day), which may reflect both severer obstruction and a role for vescico-ureteral reflux, induced by the stent. Conclusions Symptomatic urinary tract dilatation may be associated with

  10. Open versus percutaneous dilatational tracheostomy: efficacy and cost analysis.

    PubMed

    Grover, A; Robbins, J; Bendick, P; Gibson, M; Villalba, M

    2001-04-01

    The economic advantages of percutaneous dilatational tracheostomies versus open tracheostomies in the operating room have been thoroughly evaluated. We are now reporting our comparison of the costs and charges of percutaneous dilatational tracheostomies with those of open bedside tracheostomies at our institution. The current literature comparing the two open techniques and the percutaneous method of placing tracheostomies was reviewed and the charges and costs for these procedures at our institution were compared. Patients were placed into one of three groups for analysis: open tracheostomies in the operating room (Group I), open tracheostomies in the intensive care unit (Group II), and percutaneous dilatational tracheostomies in the intensive care unit (Group III). Based on our own experience and a literature review it is evident that all three approaches to tracheostomies are safe. Economic analysis showed a savings of $180 in cost per procedure and a $658 savings in charges per procedure for the open method at the bedside when compared with the percutaneous method at the bedside. The professional fee for bronchoscopy was not included in this calculation; including this would lead to greater savings with the open method over the percutaneous method. Open tracheostomy in the operating room increased costs over the bedside procedure by $2194 and increased charges by $2871. For the 150 to 180 tracheostomies done each year at our institution utilization of the open technique at the bedside results in a cost savings of approximately $31,500 and a charge savings of $109,000 compared with the percutaneous dilatational tracheostomy. Both the open bedside and percutaneous dilatational methods are reasonable and safe options. However, the open bedside tracheostomy is a better utilization of resources and is more cost effective, and it is the procedure of choice at our institution.

  11. Development of dilated cardiomyopathy in Bmal1-deficient mice

    PubMed Central

    Lefta, Mellani; Campbell, Kenneth S.; Feng, Han-Zhong; Jin, Jian-Ping

    2012-01-01

    Circadian rhythms are approximate 24-h oscillations in physiology and behavior. Circadian rhythm disruption has been associated with increased incidence of hypertension, coronary artery disease, dyslipidemia, and other cardiovascular pathologies in both humans and animal models. Mice lacking the core circadian clock gene, brain and muscle aryl hydrocarbon receptor nuclear translocator (ARNT)-like protein (Bmal1), are behaviorally arrhythmic, die prematurely, and display a wide range of organ pathologies. However, data are lacking on the role of Bmal1 on the structural and functional integrity of cardiac muscle. In the present study, we demonstrate that Bmal1−/− mice develop dilated cardiomyopathy with age, characterized by thinning of the myocardial walls, dilation of the left ventricle, and decreased cardiac performance. Shortly after birth the Bmal1−/− mice exhibit a transient increase in myocardial weight, followed by regression and later onset of dilation and failure. Ex vivo working heart preparations revealed systolic ventricular dysfunction at the onset of dilation and failure, preceded by downregulation of both myosin heavy chain isoform mRNAs. We observed structural disorganization at the level of the sarcomere with a shift in titin isoform composition toward the stiffer N2B isoform. However, passive tension generation in single cardiomyocytes was not increased. Collectively, these findings suggest that the loss of the circadian clock gene, Bmal1, gives rise to the development of an age-associated dilated cardiomyopathy, which is associated with shifts in titin isoform composition, altered myosin heavy chain gene expression, and disruption of sarcomere structure. PMID:22707558

  12. Diagnostic value of hysteroscopy: correlation with histological findings after dilatation and curettage and hysterectomy.

    PubMed

    Piccolboni, G; Arlacchi, E; Cattani, P; Zardini, R; Lavanda, E; Zardini, E

    1991-01-01

    The Authors carried out a comparative assessment of hysteroscopy diagnosis and histological findings obtained by dilatation and curettage and hysterectomy. Analysis of the data shows a good correlation between hysteroscopic diagnosis and histological findings obtained with dilatation and curettage.

  13. 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

  14. 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.

  15. Joint Symbolic Dynamics Analysis of Heart Rate and Systolic Blood Pressure Interactions in Dilated Cardiomyopathy

    DTIC Science & Technology

    2007-11-02

    Abstract- The dilated cardiomyopathy (DCM) induces important changes in the autonomic control. Measures of heart rate (HR) variability and systolic...rather simple physiological interpretations and seems to be particularly suitable for risk stratification in patients with dilated cardiomyopathy ...Keywords - Symbolic dynamics, heart rate variability, blood pressure variability I. INTRODUCTION Patients suffering from dilated cardiomyopathy

  16. 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.

  17. New Altered Non-Fibrillar Collagens in Human Dilated Cardiomyopathy: Role in the Remodeling Process

    PubMed Central

    Ortega, Ana; Tarazón, Estefanía; Triviño, Juan Carlos; Martínez-Dolz, Luis; González-Juanatey, José Ramón; Lago, Francisca; Portolés, Manuel; Rivera, Miguel

    2016-01-01

    Background In dilated cardiomyopathy (DCM), cardiac failure is accompanied by profound alterations of extracellular matrix associated with the progression of cardiac dilation and left ventricular (LV) dysfunction. Recently, we reported alterations of non-fibrillar collagen expression in ischemic cardiomyopathy linked to fibrosis and cardiac remodeling. We suspect that expression changes in genes coding for non-fibrillar collagens may have a potential role in DCM development. Objectives This study sought to analyze changes in the expression profile of non-fibrillar collagen genes in patients with DCM and to examine relationships between cardiac remodeling parameters and the expression levels of these genes. Methods and Results Twenty-three human left ventricle tissue samples were obtained from DCM patients (n = 13) undergoing heart transplantation and control donors (n = 10) for RNA sequencing analysis. We found increased mRNA levels of six non-fibrillar collagen genes, such as COL4A5, COL9A1, COL21A1, and COL23A1 (P < 0.05 for all), not previously described in DCM. Protein levels of COL8A1 and COL16A1 (P < 0.05 for both), were correspondingly increased. We also identified TGF-β1 significantly upregulated and related to both COL8A1 and COL16A1. Interestingly, we found a significant relationship between LV mass index and the gene expression level of COL8A1 (r = 0.653, P < 0.05). Conclusions In our research, we identified new non-fibrillar collagens with altered expression in DCM, being COL8A1 overexpression directly related to LV mass index, suggesting that they may be involved in the progression of cardiac dilation and remodeling. PMID:27936202

  18. 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

  19. Data of methylome and transcriptome derived from human dilated cardiomyopathy.

    PubMed

    Jo, Bong-Seok; Koh, In-Uk; Bae, Jae-Bum; Yu, Ho-Yeong; Jeon, Eun-Seok; Lee, Hae-Young; Kim, Jae-Joong; Choi, Murim; Choi, Sun Shim

    2016-12-01

    Alterations in DNA methylation and gene expression have been implicated in the development of human dilated cardiomyopathy (DCM). Differentially methylated probes (DMPs) and differentially expressed genes (DEGs) were identified between the left ventricle (LV, a pathological locus for DCM) and the right ventricle (RV, a proxy for normal hearts). The data in this DiB are for supporting our report entitled "Methylome analysis reveals alterations in DNA methylation in the regulatory regions of left ventricle development genes in human dilated cardiomyopathy" (Bong-Seok Jo, In-Uk Koh, Jae-Bum Bae, Ho-Yeong Yu, Eun-Seok Jeon, Hae-Young Lee, Jae-Joong Kim, Murim Choi, Sun Shim Choi, 2016) [1].

  20. 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.

  1. Measuring cervical dilatation in human parturition using the Hall effect.

    PubMed

    Kriewall, T J; Work, B A

    1977-01-01

    An instrument was developed to continuously measure cervical dilatation in human labor. The instrument utilizes a small magnetic field source, which is attached to one edge of the cervix while a magnetic field sensor is attached to the diametrically opposite edge of the cervix. The sensor, using two Hall generators, measures orthogonal components of the field to minimize the effects of angular orientation between the source and sensor. The instrument's characteristics indicate that it can measure dilation throughout the range of 1-10 cm, but because its clinical reliability is consistent from only 1-7 cm, the equipment needs to be improved in the ways outlined in the text. This measurement, especially when analyzed with the continous measurement of intrauterine pressure, can provide the obstetrician with new insight into the physiology of labor.

  2. 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

  3. 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

  4. 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

  5. Role of diastolic properties in the transition to failure in a mouse model of the cardiac dilatation.

    PubMed

    Costandi, Peter N; Frank, Lawrence R; McCulloch, Andrew D; Omens, Jeffrey H

    2006-12-01

    Although the physiological states of hypertrophic remodeling and congestive heart failure have been intensively studied, less is known about the transition from one to the other. The use of genetically engineered murine models of heart failure has proven valuable in characterizing the progression of remodeling and its ultimate decompensation to failure. Mice deficient in the cytoskeletal muscle LIM-only protein (MLP) are known to present with a clinical picture of dilated cardiomyopathy and transition to failure as adults. Longitudinal high-field magnetic resonance (MR) cardiac imaging provided a time course of remodeling where an improvement in ejection fraction and stroke volume (15- vs. 31-wk MLP(-/-) mice; P < 0.0001) was temporally concurrent with an abrupt phase of end-diastolic chamber dilatation. Hemodynamic analysis conducted throughout that dilatation phase showed improved ratio of maximum first derivative of pressure to end-diastolic pressure (dP/dt(max)/EDP; 15- vs. 31-wk MLP(-/-) mice; P < 0.0005), ratio of minimum first derivative of pressure to EDP (dP/dt(min)/EDP; 15- vs. 31-wk MLP(-/-) mice; P < 0.003), and developed pressure (15- vs. 31-wk MLP(-/-) mice; P < 0.0001) levels in the MLP(-/-) mice. Computational modeling techniques were used to estimate the EDP volume relationship, revealing that although MLP hearts possess a stiffer stress-strain relation, chamber compliance increased as a function of dilatation. This detailed physiological characterization during a phase of rapid anatomical remodeling suggests that systolic function in the MLP(-/-) mice may temporarily improve as a result of alterations in chamber compliance, which are mediated by dilatation. In turn, a balance may exist between exploiting the Frank-Starling mechanism and altering chamber compliance that maintains function in the absence of hypertrophic growth. Though initially compensatory, this process may exhaust itself and consequently transition to a maladaptive course.

  6. [Severe obstructive sleep apnea-hypopnea syndrome with dilated cardiomyopathy leading to pulmonary hypertension: case report and literature review].

    PubMed

    Chen, R K; Hong, C; Zhou, Y M; Kuang, A L; Zhang, Y T; Qing, S M; Liu, C L; Zhang, N F

    2017-01-12

    Objective: To study the relationship between dilated cardiomyopathy and obstructive sleep apnea-hypopnea syndrome (OSAHS) and to evaluate the curative effects of continuous positive airway pressure (CPAP) in OSAHS complicated with dilated cardiomyopathy. Methods: We reported one case with the symptom of exertional dyspnea for 1 year and aggravating for 1 month. The patient finally was diagnosed with severe OSAHS complicated with dilated cardiomyopathy leading to pulmonary hypertension. A systematic literature review was performed for similar published cases in Pubmed, Wanfang and CNKI database, using the keywords (obstructive sleep apnea) OR(OSA) OR(OSAHS) AND(dilated cardiomyopathy OR DCM)from January 1990 to May 2016. Results: Our patient had no significant improvement after receiving initial treatments, including reducing cardiac preload, improving myocardial metabolism, increasing myocardial contractility, and anticoagulants. After the patient was diagnosed as having severe OSAHS by polysomnography(PSG) and treated with CPAP, his symptoms improved remarkably. The enlarged heart became smaller and the patient had no repeated dyspnea at follow-up examination. By literature review, we found 4 English original articles and 6 Chinese articles (1 review article, 1 expert note, 1 original article and 3 case reports) on OSAHS complicated by DCM.Four Chinese and 1 English articles reported that the symptoms and parameters of OSAHS with DCM was improved remarkably after treatment with CPAP. Conclusion: For patients with dilated cardiomyopathy which fails to conventional therapy, especially those accompanied by obesity, snoring, daytime sleepiness, morning dry mouth and other related symptoms, PSG should be carried out. Early CPAP therapy could improve symptoms and prognosis of OSAHS associated with DCM.

  7. [Optimal indication for surgical ventricular restoration for dilated cardiomyopathy].

    PubMed

    Wakasa, Satoru; Shingu, Yasushige; Kubota, Suguru; Minamida, Taro; Iijima, Makoto; Naito, Yuji; Ooka, Tomonori; Tachibana, Tsuyoshi; Matsui, Yoshiro

    2013-01-01

    In this study, we assessed mid-term results of surgical ventricular restoration (SVR) for dilated cardiomyopathy. The study subjects were 107 patients who underwent SVR for both ischemic (ischemic cardiomyopathy:ICM, n=57) and non-ischemic (dilated cardiomyopathy:DCM, n=50) dilated cardiomyopathy. In 49(86%)patients ICM was associated with New York heart Association(NYHA) class III or more. Preoperative left ventricular ejection fraction (LVEF) and left ventricular end-diastolic dimension(LVDd)were 22±6% and 67±9 mm, respectively. Hospital mortality was 14% and 5-year mortality was 40%. In contrast, 46( 92%) of the DCM patients presented with NYHA class III or more. Preoperative LVEF and LVDd were 20±6% and 74±9 mm, respectively. Hospital mortality was 28% and 5-year mortality was 63%. For NYHA class III or less, however, 5-year mortality rates were 23% and 39% in those with ICM and DCM, respectively. For those with NYHA functional class III or less, SVR was associated with a satisfactory survival rate and is recommended. For those with severe heart failure, however, ventricular assist devices or heart transplantation may have to be indicated.

  8. Developing a rat model of dilated cardiomyopathy with improved survival* #

    PubMed Central

    Shen, Li-juan; Lu, Shu; Zhou, Yong-hua; Li, Lan; Xing, Qing-min; Xu, Yong-liang

    2016-01-01

    To compare the continuous infusion and intermittent bolus injection administration protocols of doxorubicin (Dox) under the same cumulative dose (12 mg/kg), and establish a rat dilated cardiomyopathy model with improved survival, a total of 150 Sprague-Dawley (SD) rats were divided into three groups: a control group, administered with normal saline; a Dox 1 group, administration twice a week at 1 mg/kg; a Dox 2, administration once a week at 2 mg/kg. Mortality rates in the Dox 1 and Dox 2 groups were 22% and 48%, respectively (P<0.05). As shown by echocardiography, both Dox groups exhibited significant chamber dilatation and reduced cardiac function (all P<0.05 vs. control). Plasma brain natriuretic peptide and C-reactive protein concentrations were significantly increased (P<0.05) with both Dox regimens. The concentrations of Caspase-3 in myocardial tissues of rats significantly increased in both doxorubicin regimens. Myocardial metabolism imaging by histology and 18F-fluoro-deoxyglucose-positron emission tomography (18FDG-PET) both revealed decreased myocardial viability and necrosis, and even interstitial fibrosis, in left ventricles (LVs) in both Dox groups. Serum creatinine and aspartate aminotransferase concentrations were significantly higher in the Dox 2 model than in the Dox 1 model. Doxorubicin given at both regimens induced dilated cardiomyopathy, while its administration at lower doses with more frequent infusions reduced the mortality rate. PMID:27921402

  9. Dilatation-dissipation corrections for advanced turbulence models

    NASA Technical Reports Server (NTRS)

    Wilcox, David C.

    1992-01-01

    This paper analyzes dilatation-dissipation based compressibility corrections for advanced turbulence models. Numerical computations verify that the dilatation-dissipation corrections devised by Sarkar and Zeman greatly improve both the k-omega and k-epsilon model predicted effect of Mach number on spreading rate. However, computations with the k-gamma model also show that the Sarkar/Zeman terms cause an undesired reduction in skin friction for the compressible flat-plate boundary layer. A perturbation solution for the compressible wall layer shows that the Sarkar and Zeman terms reduce the effective von Karman constant in the law of the wall. This is the source of the inaccurate k-gamma model skin-friction predictions for the flat-plate boundary layer. The perturbation solution also shows that the k-epsilon model has an inherent flaw for compressible boundary layers that is not compensated for by the dilatation-dissipation corrections. A compressibility modification for k-gamma and k-epsilon models is proposed that is similar to those of Sarkar and Zeman. The new compressibility term permits accurate predictions for the compressible mixing layer, flat-plate boundary layer, and a shock separated flow with the same values for all closure coefficients.

  10. Congenital Intrahepatic Bile Duct Dilatation is a Potentially Curable Disease

    PubMed Central

    Mabrut, Jean-Yves; Partensky, Christian; Jaeck, Daniel; Oussoultzoglou, Elie; Baulieux, Jacques; Boillot, Olivier; Lerut, Jan; de Ville de Goyet, Jean; Hubert, Catherine; Otte, Jean-Bernard; Audet, Maxime; Ducerf, Christian; Gigot, Jean-François

    2007-01-01

    Objective: To report clinical presentation, perioperative outcome, and long-term results of surgical management of congenital intrahepatic bile duct (IHBD) dilatations (including Caroli disease) in a multi-institutional setting. Summary Background Data: Congenital IHBD dilatations are a rare congenital disorder predisposing to intrahepatic stones, cholangitis, and cholangiocarcinoma. The management remains difficult and controversial for bilobar forms of the disease or when concurrent congenital hepatic fibrosis is associated. Methods: From 1976 to 2004, 33 patients (range 11 to 79 years) were retrospectively enrolled. Disease extent into the liver was unilobar in 26 patients and bilobar in 7 patients (21%). Cholangiocarcinoma, congenital hepatic fibrosis, and intrahepatic stones were present in 2, 10, and 20 patients, respectively. Transplantations or liver resections were performed in 5 and 27 patients, respectively, whereas 1 asymptomatic patient was managed conservatively. Results: Postoperative mortality was nil. Postoperative complications occurred in 16 of 32 operated patients (50%) and additional procedures for residual stones were required in 5 patients. During a median follow-up of 80 months (1 patient being lost for follow-up) no patient developed metachronous carcinoma. Six patients (30%) developed recurrent intrahepatic stones but satisfactory late outcome was achieved in 27 patients (87%). Conclusions: Partial or total liver resection achieves satisfactory late outcome in congenital IHBD dilatations, when the affection is treated at an early stage and when the extent of liver resection is tailored to intrahepatic disease extent and takes into consideration the presence and severity of underlying chronic liver and renal diseases. PMID:17667502

  11. 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.

  12. 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

  13. Dilated Basilar Arteries in Patients with Congenital Central Hypoventilation Syndrome

    PubMed Central

    Kumar, Rajesh; Nguyen, Haidang D.; Macey, Paul M.; Woo, Mary A.; Harper, Ronald M.

    2009-01-01

    Congenital central hypoventilation syndrome (CCHS) patients show hypoventilation during sleep and severe autonomic impairments, including aberrant cardiovascular regulation. Abnormal sympathetic patterns, together with increased and variable CO2 levels, lead to the potential for sustained cerebral vasculature changes. We performed high-resolution T1-weighted imaging in 13 CCHS and 31 control subjects using a 3.0-Tesla magnetic resonance imaging scanner, and evaluated resting basilar and bilateral middle cerebral artery cross-sections. Two T1-weighted image series were acquired; images were averaged and reoriented to common space, and regions containing basilar and both middle cerebral arteries were oversampled. Cross-sections of the basilar and middle cerebral arteries were manually outlined to calculate cross-sectional areas, and differences between and within groups were evaluated. Basilar arteries in CCHS were significantly dilated over control subjects, but both middle cerebral artery cross-sections were similar between groups. No significant differences appeared between left and right middle cerebral arteries within either group. Basilar artery dilation may result from differential sensitivity to high CO2 over other vascular beds, damage to serotonergic or other chemosensitive cells accompanying the artery, or enhanced microvascular resistance, and that dilation may impair tissue perfusion, leading to further neural injury in CCHS. PMID:19822189

  14. Demosaicking using geometric duality and dilated directional differentiation

    NASA Astrophysics Data System (ADS)

    Kim, Joohyeok; Jeon, Gwanggil; Jeong, Jechang

    This paper presents a new demosaicking algorithm which uses two cost terms: the interpolation error of a low resolution image based on geometric duality and the dilated directional differentiation of color differences. Since a given high resolution image and its low resolution image obtained by sampling have similar edge properties, the proposed algorithm computes the interpolation errors for the candidate directions in the low resolution image, and exploits them as a cost term for the direction. In addition, the interpolation direction can be determined accurately even in the vicinity of object boundaries by dilating the directional differentiation of the color difference values. Through dilation, some pixels, which are in the neighborhood of an edge but classified into a flat region by simple edge detection like the Sobel filter, are reclassified. By combining this edge classifier and the weighted sum of the estimates obtained by Taylor approximation, missing pixels are interpolated. Simulation results show that the proposed demosaicking algorithm is superior to other state-of-the-art algorithms in terms of visual and objective qualities. Furthermore, the computational complexity is comparable with the existing algorithms. Therefore, the proposed algorithm is suitable for real-time implementation.

  15. 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.

  16. 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

  17. Hybrid cutting balloon dilatation for treatment of cor triatriatum sinister in a cat.

    PubMed

    Stern, Joshua A; Tou, Sandra P; Barker, Piers C A; Hill, Kevin D; Lodge, Andrew J; Mathews, Kyle G; Keene, Bruce W

    2013-09-01

    A hybrid surgical approach and balloon dilatation were performed successfully in a cat with cor triatriatum sinister and clinical signs of congestive heart failure. Left lateral thoracotomy was used to access the heart and cutting balloon followed by standard balloon dilatation were utilized to dilate the perforation in the anomalous left atrial membrane. Clinical signs resolved completely after dilation of the anomalous left atrial membrane. Based upon the outcome of this case, balloon dilatation appears to be a viable treatment option for cats affected with cor triatriatum sinister.

  18. 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

  19. 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.

  20. 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.

  1. Is endoscopic papillary large balloon dilation safe for treating large CBD stones?

    PubMed

    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.

  2. 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

  3. 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.

  4. 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.

  5. Discontinuous Shear Thickening and Dilatancy: Frictional Effects in Viscous Suspensions

    NASA Astrophysics Data System (ADS)

    Morris, Jeffrey

    2015-03-01

    Shear thickening in concentrated suspensions has been well-known for quite a long time, yet a firm consensus on the basis for very abrupt or ``discontinuous'' shear thickening (DST) seen in suspensions of large solid fraction, ϕ, has not been reached. This work addresses the DST phenomenon, and proposes a simulation method based in the Stokesian Dynamics algorithm to explore the role of various forces between the particles, including hydrodynamic, conservative potential, and frictional interactions. This work shows that allowance for friction between spherical particles suspended in a viscous liquid causes a significant reduction in the jamming solid fraction of the mixture, ϕmax, taken as the maximum fraction at which the suspension will flow. A consequence of this is a shifting of the singularity in the effective viscosity, η, to smaller ϕmax, and the frictional suspension has a larger viscosity than does the frictionless suspension of the same solid fraction, as is clear from the standard empirical modeling of η (ϕ) =(1 - ϕ /ϕmax) - α , α ~ 2 . When a counterbalancing repulsive force between the particles, representative for example of charge-induced repulsion, is incorporated in the dynamics, the mixture undergoes a transition from frictionless to frictional interactions, and from low to high effective viscosity, at a critical shear rate. Comparison with experimental data shows remarkable agreement in the features of DST captured by the method. The basic algorithm and results of both rate-controlled and stress-controlled simulations will be presented. Like the shear stress, the magnitude of the normal stress exerted by the suspended particles also increases abruptly at the critical shear rate, consistent with the long-standing notion that dilatancy and shear-thickening are synonymous. We will show that considering all shear thickening materials as dilatant is a misconception, but demonstrate the validity of the connection of dilatancy with DST in

  6. 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.

  7. 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.

  8. Completely obstructed colorectal anastomosis: a new non-electrosurgical endoscopic approach before balloon dilatation.

    PubMed

    Curcio, Gabriele; Spada, Marco; di Francesco, Fabrizio; Tarantino, Ilaria; Barresi, Luca; Burgio, Gaetano; Traina, Mario

    2010-10-07

    Benign stricture is a relatively common complication of colorectal anastomosis after low anterior resection. On occasion, the anastomosis may close completely. A variety of endoscopic techniques have been described, but there is a lack of data from controlled prospective trials as to the optimal approach. Through-the-scope balloon dilatation is well known and easy to perform. Some case reports describe different endoscopic approaches, including endoscopic electrocision with a papillotomy knife or hook knife. We report a case of a colorectal anastomosis web occlusion, treated without electrocision. Gastrografin enema and sigmoidoscopy showed complete obstruction at the anastomotic site due to the presence of an anastomotic occlusive web. In order to avoid thermal injuries, we decided to use a suprapapillary biliary puncture catheter. The Artifon catheter was inserted into the center of the circular staple line at the level of the anastomosis, and fluoroscopic identification of the proximal bowel was obtained with dye injection. A 0.025-inch guidewire was then passed through the catheter into the colon and progressive pneumatic dilatation was performed. The successful destruction of the occlusive web facilitated passage of the colonoscope, allowing evaluation of the entire colon and stoma closure after three months of follow-up. The patient tolerated the procedure well, with no complications. This report highlights an alternative non-electrosurgical approach that uses a new device that proved to be safe and useful.

  9. Endoluminal dilation technique to remove "stuck" tunneled hemodialysis catheters.

    PubMed

    Ryan, Stephen E; Hadziomerovic, Adnan; Aquino, Jose; Cunningham, Ian; O'Kelly, Kevin; Rasuli, Pasteur

    2012-08-01

    Most tunneled catheters can be easily removed after the retention cuff is dissected. Occasionally, these catheters can become resistant to removal even after application of potentially hazardous forceful traction. In addition, an infected catheter may cause life-threatening septicemia. Several methods have been described for their extraction, some of which may be available only in tertiary-care facilities. The present report describes the successful extraction of five such "stuck" catheters by using a recently described technique of endoluminal dilation. The technique appears safe and straightforward and can be performed in any interventional suite while allowing preservation of venous access.

  10. The dilatant-compactant transition in edifice-forming andesites

    NASA Astrophysics Data System (ADS)

    Heap, Michael; Farquharson, Jamie; Baud, Patrick; Lavallée, Yan; Reuschlé, Thierry

    2015-04-01

    While the mechanical behaviour of rock is often classified as brittle or ductile, ductile behaviour, defined simply as the capacity of a material to deform to a substantial strain without the tendency to localise the flow into faults, can be the result of a variety of microstructural deformation mechanisms, including microcracking (in the case of cataclastic flow); the description of ductility holds no mechanistic connotation. However, due to instances of compaction localisation, and that ductile behaviour can be driven by microcracking (i.e., brittle on the microscale), we have simplified our classification of the failure mode of rock to "dilatant" and "compactant". The failure mode of lava -- dilatant or compactive -- depends on the physical attributes of the lava, primarily the porosity and pore size, and the conditions under which it deforms. The failure mode for edifice host rock has attendant implications for the structural stability of the edifice and the efficiency of sidewall outgassing of the volcanic conduit. In this contribution we present a systematic experimental study on the failure mode of edifice-forming andesitic rocks (porosity from 8 to 25%) from Volcán de Colima, Mexico. The experiments show that, at shallow depths (< 1 km), both low and high porosity lavas dilate and fail by shear fracturing. However, deeper in the edifice (> 1 km), while low porosity (< 10%) lava remains dilatant, the failure of high porosity lava is compactive and driven by cataclastic pore collapse. Although inelastic compaction is typically characterised by the absence of strain localisation, we observe compactive localisation features in our porous andesite lavas manifested as planes of collapsed pores. In terms of volcano stability, faulting in the upper edifice could destabilise the volcano, leading to an increased risk of flank or large-scale dome collapse, while compactive deformation deeper in the edifice emerges as a viable mechanism driving volcano subsidence and

  11. Multiple Loci are associated with dilated cardiomyopathy in Irish wolfhounds.

    PubMed

    Philipp, Ute; Vollmar, Andrea; Häggström, Jens; Thomas, Anne; Distl, Ottmar

    2012-01-01

    Dilated cardiomyopathy (DCM) is a highly prevalent and often lethal disease in Irish wolfhounds. Complex segregation analysis indicated different loci involved in pathogenesis. Linear fixed and mixed models were used for the genome-wide association study. Using 106 DCM cases and 84 controls we identified one SNP significantly associated with DCM on CFA37 and five SNPs suggestively associated with DCM on CFA1, 10, 15, 21 and 17. On CFA37 MOGAT1 and ACSL3 two enzymes of the lipid metabolism were located near the identified SNP.

  12. Symmetrization of grey-scale images based on dilation

    NASA Astrophysics Data System (ADS)

    Tuzikov, Alexander V.; Krivonos, O. V.

    1996-03-01

    We generalize set symmetrization transformations based on Minkowski addition to symmetrization transformations for numerical functions. For this purpose two types of function representation are used. The first one is umbra representation, when symmetrization transformations are performed to the set of points under the graph of a function. This corresponds to introducing of transformations using gray-scale dilation. The second representation of a function is based on a family of threshold sets. Flat function symmetrization transformations are generated by corresponding set transformations operating on threshold sets.

  13. Wavelet transforms with discrete-time continuous-dilation wavelets

    NASA Astrophysics Data System (ADS)

    Zhao, Wei; Rao, Raghuveer M.

    1999-03-01

    Wavelet constructions and transforms have been confined principally to the continuous-time domain. Even the discrete wavelet transform implemented through multirate filter banks is based on continuous-time wavelet functions that provide orthogonal or biorthogonal decompositions. This paper provides a novel wavelet transform construction based on the definition of discrete-time wavelets that can undergo continuous parameter dilations. The result is a transformation that has the advantage of discrete-time or digital implementation while circumventing the problem of inadequate scaling resolution seen with conventional dyadic or M-channel constructions. Examples of constructing such wavelets are presented.

  14. 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.

  15. Epidemiology and Natural History of Recovery of Left Ventricular Function in Recent Onset Dilated Cardiomyopathies

    PubMed Central

    Givertz, Michael M.; Mann, Douglas L.

    2013-01-01

    Although the long term prognosis of patients with dilated cardiomyopathy (DCM) remains poor, approximately 25% of DCM patients with recent onset of heart failure (< 6 months) have a relatively benign clinical course with a spontaneously improvement in symptoms and partial, or in some cases complete, recovery of left ventricular (LV) function. Despite the longstanding recognition of the clinical phenomenon of LV recovery, relatively little attention has been paid to the etiology and natural history of this important group of DCM patients. Accordingly, in the present review we will focus on the epidemiology and natural history of recent onset DCM in patients who undergo spontaneous resolution of symptoms that is accompanied by recovery of LV function. PMID:24014141

  16. Adaptive pseudo dilation for gestalt edge grouping and contour detection.

    PubMed

    Papari, Giuseppe; Petkov, Nicolai

    2008-10-01

    We consider the problem of detecting object contours in natural images. In many cases, local luminance changes turn out to be stronger in textured areas than on object contours. Therefore, local edge features, which only look at a small neighborhood of each pixel, cannot be reliable indicators of the presence of a contour, and some global analysis is needed. We introduce a new morphological operator, called adaptive pseudo-dilation (APD), which uses context dependent structuring elements in order to identify long curvilinear structure in the edge map. We show that grouping edge pixels as the connected components of the output of APD results in a good agreement with the gestalt law of good continuation. The novelty of this operator is that dilation is limited to the Voronoi cell of each edge pixel. An efficient implementation of APD is presented. The grouping algorithm is then embedded in a multithreshold contour detector. At each threshold level, small groups of edges are removed, and contours are completed by means of a generalized reconstruction from markers. The use of different thresholds makes the algorithm much less sensitive to the values of the input parameters. Both qualitative and quantitative comparison with existing approaches prove the superiority of the proposed contour detector in terms of larger amount of suppressed texture and more effective detection of low-contrast contours.

  17. Dilated cardiomyopathy: the complexity of a diverse genetic architecture.

    PubMed

    Hershberger, Ray E; Hedges, Dale J; Morales, Ana

    2013-09-01

    Remarkable progress has been made in understanding the genetic basis of dilated cardiomyopathy (DCM). Rare variants in >30 genes, some also involved in other cardiomyopathies, muscular dystrophy, or syndromic disease, perturb a diverse set of important myocardial proteins to produce a final DCM phenotype. Large, publicly available datasets have provided the opportunity to evaluate previously identified DCM-causing mutations, and to examine the population frequency of sequence variants similar to those that have been observed to cause DCM. The frequency of these variants, whether associated with dilated or hypertrophic cardiomyopathy, is greater than estimates of disease prevalence. This mismatch might be explained by one or more of the following possibilities: that the penetrance of DCM-causing mutations is lower than previously thought, that some variants are noncausal, that DCM prevalence is higher than previously estimated, or that other more-complex genomics underlie DCM. Reassessment of our assumptions about the complexity of the genomic and phenomic architecture of DCM is warranted. Much about the genomic basis of DCM remains to be investigated, which will require comprehensive genomic studies in much larger cohorts of rigorously phenotyped probands and family members than previously examined.

  18. The locus for bovine dilated cardiomyopathy maps to chromosome 18.

    PubMed

    Guziewicz, K E; Owczarek-Lipska, M; Küffer, J; Schelling, C; Tontis, A; Denis, C; Eggen, A; Leeb, T; Dolf, G; Braunschweig, M H

    2007-06-01

    Bovine dilated cardiomyopathy (BDCMP) is a severe and terminal disease of the heart muscle observed in Holstein-Friesian cattle over the last 30 years. There is strong evidence for an autosomal recessive mode of inheritance for BDCMP. The objective of this study was to genetically map BDCMP, with the ultimate goal of identifying the causative mutation. A whole-genome scan using 199 microsatellite markers and one SNP revealed an assignment of BDCMP to BTA18. Fine-mapping on BTA18 refined the candidate region to the MSBDCMP06-BMS2785 interval. The interval containing the BDCMP locus was confirmed by multipoint linkage analysis using the software loki. The interval is about 6.7 Mb on the bovine genome sequence (Btau 3.1). The corresponding region of HSA19 is very gene-rich and contains roughly 200 genes. Although telomeric of the marker interval, TNNI3 is a possible positional and a functional candidate for BDCMP given its involvement in a human form of dilated cardiomyopathy. Sequence analysis of TNNI3 in cattle revealed no mutation in the coding sequence, but there was a G-to-A transition in intron 6 (AJ842179:c.378+315G>A). The analysis of this SNP using the study's BDCMP pedigree did not conclusively exclude TNNI3 as a candidate gene for BDCMP. Considering the high density of genes on the homologous region of HSA19, further refinement of the interval on BTA18 containing the BDCMP locus is needed.

  19. 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.

  20. 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.

  1. Multiple Genetic Associations with Irish Wolfhound Dilated Cardiomyopathy

    PubMed Central

    Dunning, Mark D.; Brownlie, Serena

    2016-01-01

    Cardiac disease is a leading cause of morbidity and mortality in dogs and humans, with dilated cardiomyopathy being a large contributor to this. The Irish Wolfhound (IWH) is one of the most commonly affected breeds and one of the few breeds with genetic loci associated with the disease. Mutations in more than 50 genes are associated with human dilated cardiomyopathy (DCM), yet very few are also associated with canine DCM. Furthermore, none of the identified canine loci explain many cases of the disease and previous work has indicated that genotypes at multiple loci may act together to influence disease development. In this study, loci previously associated with DCM in IWH were tested for associations in a new cohort both individually and in combination. We have identified loci significantly associated with the disease individually, but no genotypes individually or in pairs conferred a significantly greater risk of developing DCM than the population risk. However combining three loci together did result in the identification of a genotype which conferred a greater risk of disease than the overall population risk. This study suggests multiple rather than individual genetic factors, cooperating to influence DCM risk in IWH. PMID:28070514

  2. Surface dilational rheological properties in the nonlinear domain.

    PubMed

    Bykov, A G; Liggieri, L; Noskov, B A; Pandolfini, P; Ravera, F; Loglio, G

    2015-08-01

    The interfacial tension response to dilational deformation of interfacial area exhibits a (more or less) nonlinear behavior, depending on the amplitude of the deformation. Studies of such observable interfacial properties in the nonlinear domain suggest valuable information about the two-dimensional microstructure of the interfacial layer, as well as about the structure time-evolution. In this article, the emphasis is centered on the available mathematical methods for quantitatively analyzing and describing the magnitude and the characteristics of the nonlinear interfacial viscoelastic properties. Specifically, in periodic oscillation experiments the nonlinear behavior can be represented by the combination of a linear part (the surface dilational modulus), with an additional complementary Fourier analysis parameterizing the nonlinearity. Also asymmetric Lissajous plots, of interfacial tension versus deformation, are useful tools for expanding the response nonlinearity into four distinct components relevant to significant points of the cyclic loop. In connection with the mathematical methods, nonequilibrium thermodynamic formulations provide a powerful theoretical framework for investigating the interfacial dynamic properties of multiphase systems. Experimental results for adsorption layers of complex components, available in the literature, show notable nonlinear interfacial viscoelastic behavior. In particular in this review, data are illustrated for solutions of polymers and of polyelectrolyte/surfactant complexes. The observed nonlinear findings reveal formation of complexes, patches, and other different interfacial structures.

  3. Percutaneous transluminal balloon dilatation of the mitral valve in pregnancy.

    PubMed Central

    Smith, R; Brender, D; McCredie, M

    1989-01-01

    Pregnancy can cause life threatening complications in women with mitral stenosis, and there is a substantial risk of fetal death if valvotomy under cardiopulmonary bypass is required. A patient is described in whom pulmonary oedema developed after delivery of her first child by caesarean section 13 months previously. Subsequent cardiac catheterisation showed severe mitral stenosis (valve area 0.96 cm2, valve gradient 12 mm Hg, pulmonary artery pressure 30/16 mm Hg). Before valvotomy could be performed the patient again became pregnant and presented in pulmonary oedema at twenty two weeks' gestation. Medical treatment was unsuccessful and she underwent percutaneous transluminal balloon dilatation of the mitral valve. This increased the valve area to 1.78 cm2 and reduced the transmitral gradient to 6 mm Hg. The procedure was uncomplicated, and she remained symptom free on no medication. She delivered vaginally at 37 weeks' gestation. Percutaneous transluminal balloon dilatation of the mitral valve is a safe and effective alternative to mitral valvotomy in pregnancy. PMID:2757867

  4. 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.

  5. [Expansion dilatation balloons for cervical ripening in obstetric practice].

    PubMed

    Ducarme, G; Grange, J; Vital, M

    2016-02-01

    During recent decades, mechanical devices have been substituted by pharmacological methods. Their place in the therapeutic arsenal remains important with a renewed obstetrical interest for these devices. Due to a lack of data they are still not recommended as first-line. This review thus attempted to examine the use of expansion dilatation balloons (Foley catheter and double-balloons) to analyze their effectiveness in case of native uterus and previous cesarean section. Twenty-seven clinical trials had compared balloons catheter and prostaglandins in patients without a history of uterine scar. The risk of cesarean section did not differ. Mechanical methods seemed to be more effective in achieving delivery within 24hours, with fewer episodes of excessive uterine contractions, but they necessitated more oxytocin during labor. Ten clinical trials analyzed dilatation balloons in patients with previous cesarean section. More than 70% women had favorable cervical ripening (Bishop score>6), and vaginal delivery was reported between 35 and 70% of patients. The risk of uterine rupture was low between 0.64 and 0.72%, with neither increased risk of severe neonatal and maternal morbidity nor increased risk of infectious morbidity. Mechanical methods are effective and safe for third trimester cervical ripening, mainly in women with previous cesarean section. Potential advantages may include wide availability and reduction of some of the side effects.

  6. 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. PMID:27774273

  7. 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.

  8. Benidipine dilates both pre- and post-glomerular arteriole in the canine kidney.

    PubMed

    Yue, W; Kimura, S; Fujisawa, Y; Tian, R; Li, F; Rahman, M; Nishiyama, A; Fukui, T; Abe, Y

    2001-07-01

    The aim of the present study was to determine the effects of benidipine on renal function and whether benidipine may dilate the efferent arteriole as well as the afferent arteriole of the canine kidney. The effects of benidipine on the renal segmental vascular resistance were estimated using Gomez's formula with some modification. The renal hemodynamic action of benidipine was also compared with that of amlodipine. Intrarenal arterial injection of benidipine at a dose of 3 microg/kg resulted in a significant increase in renal blood flow (RBF), urine flow and urinary excretion of sodium, but not in glomerular filtration rate (GFR). Amlodipine at a dose of 300 microg/kg also increased RBF, urine flow and urinary excretion of sodium to a significant degree equivalent to that by benidipine. However, in contrast to benidipine, amlodipine significantly increased GFR. After the administration of benidipine, autoregulation of RBF and GFR was relatively maintained and the renal perfusion pressure (RPP)-RBF relation shifted upward; that is, RBFs at 75 and 50 mmHg were maintained at a higher level than those of the control. In contrast to benidipine, amlodipine diminished the autoregulation of RBF and GFR. RBFs at 75 and 50 mmHg were not different from those of the control. The afferent and efferent arteriolar resistance (Ra and Re) were calculated based on the RPP-RBF and RPP-GFR relations. Benidipine reduced both Ra and Re, but amlodipine selectively reduced Ra. Benidipine increased RBF but not GFR via the dilation of both afferent and efferent arterioles. Thus, benidipine has unique renal hemodynamic actions which differ from those by most calcium antagonists.

  9. Evaluating Adherence to Dilated Eye Examination Recommendations Among Patients with Diabetes, Combined with Patient and Provider Perspectives

    PubMed Central

    Fisher, Maxine D.; Rajput, Yamina; Gu, Tao; Singer, Joseph R.; Marshall, Amanda R.; Ryu, Seonyoung; Barron, John; MacLean, Catherine

    2016-01-01

    Background Diabetes mellitus remains the leading cause of new cases of blindness among US adults. Routine dilated eye examinations can facilitate early detection and intervention for diabetes-related eye disease, providing an opportunity to reduce the risk for diabetes-related blindness in working-aged Americans. The Healthcare Effectiveness Data and Information Set (HEDIS) established criteria for performing dilated eye examination in patients with diabetes. Objectives To obtain information about adherence and nonadherence to diabetic eye examinations among insured patients to understand the barriers to routine dilated eye examinations, and to identify ways to improve the quality of care for these patients. Methods This retrospective claims analysis is based on administrative claims from the HealthCore Integrated Research Database, a broad database representing claims from a large commercially insured population. Patients with diabetes and who had ≥1 dilated eye examinations between August 1, 2011, and July 31, 2013, were defined as adherent to the HEDIS recommendations. The analysis was augmented with findings from focus groups. The patient focus groups included adherent and nonadherent patients. The provider focus group participants were general practice or internal medicine physicians and ophthalmologists who provided medical care for the study population. For the administrative claims analysis, comparisons between the adherent and nonadherent patients were performed using t-tests for continuous data and chi-square tests for categorical data. Results Of 339,646 patients with diabetes identified in a claims data set, 43% were adherent and 57% were nonadherent to the HEDIS eye examination performance measure. The common barriers to routine eye examination cited by 29 patients across 4 focus groups included a lack of understanding of insurance benefits (N = 15), a lack of awareness of the importance of dilated eye examinations (N = 12), and time constraints (N

  10. 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

  11. Induction of cervical dilation for transcervical embryo transfer in ewes

    PubMed Central

    2014-01-01

    Background A major limitation in the application of assisted reproductive technologies in sheep arises from the inability to easily traverse the uterine cervix. The cervix of the non-pregnant ewe is a narrow and rigid structure, with 5–7 spiral folds and crypts that block its lumen. The first two folds closest to the vagina appear to be the greatest obstacle for the instrument insertion into the sheep cervix. Therefore, the dilation of the distal part of the cervix could provide the conformational change necessary to perform non-invasive transcervical procedures. The present study set out to assess the efficacy of Cervidil®, a patented dinoprostone (PgE2)-containing vaginal insert with a controlled-release mechanism, to safely induce sufficient cervical dilation for the purpose of transcervical embryo transfer (TCET) in cyclic ewes. Methods The transfer of frozen-thawed ovine embryos was attempted in 22 cross-bred Rideau Arcott x Polled Dorset ewes, with or without the pre-treatment with Cervidil® for 12 or 24 h prior to TCET. Results Cervical penetration rate was significantly improved after Cervidil® pre-treatment, with 55% (6/11) of treated versus 9% (1/11) of control animals successfully penetrated (χ2-test, p < 0.05). Within the treated ewes that were penetrated, 67% (4/6) had been exposed to Cervidil(R) for 24 h and 33% (2/6) had had a 12-h exposure (p > 0.05). Variations in the age, weight, genotype, parity, lifetime lamb production (LLP) and post-partum interval (PPI) between penetrated and non-penetrated ewes were not significant (p > 0.05). The time taken to traverse the uterine cervix was negatively correlated (p < 0.05) with the age, parity, LLP and PPI. Progesterone assays and ultrasonographic examinations performed 25 days after ET confirmed pregnancy in 2 of 7 penetrated ewes, but no fetuses were detected ultrasonographically 55 days post-TCET. Conclusions The present results indicate a significant benefit of using Cervidil

  12. 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.

  13. A Systematic Review of the Risk of Perforation During Esophageal Dilation for Patients with Eosinophilic Esophagitis

    PubMed Central

    Jacobs, John William

    2011-01-01

    Background Eosinophilic esophagitis (EoE) is associated with tissue remodeling that can result in esophageal mucosal fragility, and esophageal dilation for patients with EoE is known to cause painful mucosal lacerations. Clinicians have been admonished that patients with EoE may be exceptionally predisposed to perforation with esophageal dilation, a notion supported primarily by case reports. We have conducted a systematic review of literature on esophageal dilation in EoE in an attempt to better define the risk of perforation. Methods We searched PubMed and abstracts presented at the annual scientific meetings of the American Gastroenterological Association and the American College of Gastroenterology to identify reports on esophageal dilation in EoE. We analyzed reports meeting the following criteria: (1) the diagnosis was established from esophageal biopsy specimens revealing ≥15 eosinophils/hpf, (2) esophageal dilation was described, (3) esophageal perforations described were the result of esophageal dilation. Results We identified 18 reports for inclusion in our systematic review. The studies comprised 468 patients who underwent a total of 671 endoscopic dilations. Esophageal mucosal tears were described in most cases, but there was only one perforation among the 671 dilations (0.1%). Conclusions Our systematic review does not reveal an inordinate frequency of esophageal perforation from dilation in patients with EoE, and it is not clear that dilation is any more hazardous for patients with EoE than for patients with other causes of esophageal stricture. Although esophageal dilation must be performed with caution in all patients, the risk of perforation in EoE appears to have been exaggerated. PMID:20238250

  14. Shape Waves in 2D Josephson Junctions: Exact Solutions and Time Dilation

    NASA Astrophysics Data System (ADS)

    Gulevich, D. R.; Kusmartsev, F. V.; Savel'Ev, Sergey; Yampol'Skii, V. A.; Nori, Franco

    2008-09-01

    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.

  15. 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.

  16. 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

  17. Dilated intercellular spaces as a marker of GERD.

    PubMed

    Orlando, Lori A; Orlando, Roy C

    2009-06-01

    Gastroesophageal reflux disease (GERD) is typically heralded by the substernal burning pain of heartburn. On endoscopic examination, about one third of GERD subjects with heartburn have erosive disease, and the remainder have nonerosive reflux disease (NERD). Unlike patients with erosive disease, those with NERD (approximately 50%) often do not respond to therapy with proton pump inhibitors (PPIs), raising the question of whether they have NERD and, if they do, whether the cause of their symptoms is similar to those who respond to PPIs. Recently, biopsies established that subjects with heartburn and PPI-responsive NERD, like those with erosive esophagitis, have lesions within the esophageal epithelium known as dilated intercellular space (DIS). In this article, we discuss the physicochemical basis for DIS in acid-injured esophageal epithelium and its significance in GERD. Although DIS is not pathognomic of GERD, it is a marker of a break in the epithelial (junctional) barrier reflecting an increase in paracellular permeability.

  18. Infant and adult pupil dilation in response to unexpected sounds.

    PubMed

    Wetzel, Nicole; Buttelmann, David; Schieler, Andy; Widmann, Andreas

    2016-04-01

    Surprisingly occurring sounds outside the focus of attention can involuntarily capture attention. This study focuses on the impact of deviant sounds on the pupil size as a marker of auditory involuntary attention in infants. We presented an oddball paradigm including four types of deviant sounds within a sequence of repeated standard sounds to 14-month-old infants and to adults. Environmental and noise deviant sounds elicited a strong pupil dilation response (PDR) in both age groups. In contrast, moderate frequency deviants elicited a significant PDR in adults only. Moreover, a principal component analysis revealed two components underlying the PDR. Component scores differ, depending on deviant types, between age groups. Results indicate age effects of parasympathetic inhibition and sympathetic activation of the pupil size caused by deviant sounds with a high arousing potential. Results demonstrate that the PDR is a sensitive tool for the investigation of involuntary attention to sounds in preverbal children.

  19. The inverse problem of estimating the gravitational time dilation

    NASA Astrophysics Data System (ADS)

    Gusev, A. V.; Litvinov, D. A.; Rudenko, V. N.

    2016-11-01

    Precise testing of the gravitational time dilation effect suggests comparing the clocks at points with different gravitational potentials. Such a configuration arises when radio frequency standards are installed at orbital and ground stations. The ground-based standard is accessible directly, while the spaceborne one is accessible only via the electromagnetic signal exchange. Reconstructing the current frequency of the spaceborne standard is an ill-posed inverse problem whose solution depends significantly on the characteristics of the stochastic electromagnetic background. The solution for Gaussian noise is known, but the nature of the standards themselves is associated with nonstationary fluctuations of a wide class of distributions. A solution is proposed for a background of flicker fluctuations with a spectrum (1/ f)γ, where 1 < γ < 3, and stationary increments. The results include formulas for the error in reconstructing the frequency of the spaceborne standard and numerical estimates for the accuracy of measuring the relativistic redshift effect.

  20. Mutation in δ-Sg Gene in Familial Dilated Cardiomyopathy

    PubMed Central

    Asadi, Marzieh; Foo, Roger; Salehi, Ahmad Reza; Salehi, Rasoul; Samienasab, Mohammad Reza

    2017-01-01

    Background: Mutations in different genes including dystrophin-associated glycoprotein complex caused familial dilated cardiomyopathy which is a genetically heterogeneous disease. The δ-SG gene contains nine exons spanning a 433-kb region of genomic DNA. It encodes a 35-kDa, singlepass, and type II transmembrane glycoprotein. Materials and Methods: In this study for the first time in Iran we screened 6 patients of a large family that they had positive family history of MI or sudden death by next generation sequencing method. Results: By employing NGS method we found missense mutation (p.R97Q) of δ-SG gene in 2 of 6 patients. Conclusions: The missense mutation (p.R97Q) in familial DCM patients is reported for the first time in Iranian patients with cardiac disease. Although this mutation is already known in other populations in Iran, it is not reported before.

  1. 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

  2. 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)

  3. Pathologic aneurysmal dilation of the ascending aorta and dilation of the main pulmonary artery in patients with Kabuki syndrome: valve-sparing aortic root replacement.

    PubMed

    Dyamenahalli, Umesh; Abraham, Boban; Fontenot, Eudice; Prasad, Vinay; Imamura, Michiaki

    2007-01-01

    We report the aneurysmal dilation of the ascending aorta and the main pulmonary artery in 2 children with Kabuki syndrome. In 1 patient, there was progressive aneurysmal dilation of the ascending aorta necessitating aortoplasty. Histologic examination of the resected aorta revealed disrupted and fragmented elastic fibers in the medial layer, along with mucinous degeneration of the aortic wall. This is the first recognition and report of these findings as part of the Kabuki syndrome.

  4. 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.

  5. Stress-Dilatancy for Soils. Part I: The Frictional State Theory

    NASA Astrophysics Data System (ADS)

    Szypcio, Zenon

    2016-12-01

    An unconventional subdivision of volumetric strains, the newly formulated frictional and critical frictional states and some of energetic and stress condition assumptions result in new stress-plastic dilatancy relationships. These new stress-plastic dilatancy relationships are functions of the deformation mode and drainage conditions. The critical frictional state presented in this paper is a special case of the classical critical state.

  6. A force sensor and peak-reading recorder for measurement of cervical dilatation force.

    PubMed

    Crawford, A J; Plant, G R; Filshie, G M; Macpherson, M B; McCabe, A R

    1984-10-01

    Earlier dilatation force-sensing transducers, when subjected to side loads, suffered frictional losses which affected their accuracy. This new instrument incorporates a thermal-writing chart recorder and a digital readout of the peak force during dilatation of the cervix.

  7. 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.}

  8. Evaluation of ventricular wall stress and cardiac function in patients with dilated cardiomyopathy.

    PubMed

    Scardulla, Francesco; Rinaudo, Antonino; Pasta, Salvatore; Scardulla, Cesare

    2016-01-01

    Dilated cardiomyopathy is a heart disease characterized by both left ventricular dilatation and left ventricular systolic dysfunction, leading to cardiac remodeling and ultimately heart failure. We aimed to investigate the effect of dilated cardiomyopathy on the pump performance and myocardial wall mechanics using patient-specific finite element analysis. Results evinced pronounced end-systolic wall stress on left ventricular wall of patients with dilated cardiomyopathy as compared to that of normal hearts. In dilated cardiomyopathy, both end-diastolic and end-systolic pressure-volume relationships of left ventricle and right ventricle were shifted to the right compared to controls, suggesting reduced myocardial contractility. We hereby propose that finite element analysis represents a useful tool to assess the myocardial wall stress and cardiac work, which are responsible for progressive left ventricular deterioration and poor clinical course.

  9. 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

  10. 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

  11. [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).

  12. 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.

  13. Significance of Borrelia infection in development of dilated cardiomypathy (a pilot study).

    PubMed

    Bartůnĕk, P; Gorican, K; Veiser, T; Táborský, M; Hulínská, D

    2007-01-01

    A heart involvement known as Lyme carditis (LC), a consequence of Lyme borreliosis (LB), is relatively rare in contrast to the involvement of skin, joints and nervous system; it accounts for < 4% of all these patients in European countries. However, the diagnosis of the disease belongs to the most difficult challenges. While various forms of AV blocks dominate in the USA as confirmed by the literature, there is a clear predominance of arrhythmias of various incidence in the Czech Republic. The authors of this article focused on the form belonging to the rarest manifestations of LC, namely dilated cardiomyopathy (DCMP). The goal was to elucidate the etiological participation of Borrelia infection in the development of DCMP, which has attracted controversial opinions so far. In total, 33 patients with DCMP were enrolled in the study, 23 males and 10 females, with mean age 57.7 years (range 24-76 years). ELISA NRLB KC 90 method was used in all blood samples for detection of Borrelia infection (BI), Western blot method was used for confirmation, followed by identification of DNA of pathogenic Borreliae using PCR method. Bioptic material was examined by electronmicroscopy with an attempt to detect Spirochaetae in myocardium. 16 patients were excluded from the study owing to the absence of signs of LB. The study group included 17 patients (3 females, 13 males) with mean age 58 years (range 43-76 years), in whom the presence of Bb was proved by identification of DNA of pathogenic Borreliae or by electronmicroscopic detection of Spirochetae in myocardial bioptic sample. The findings obtained during the study confirmed that BI very probably participated in the development of dilated cardiomyopathy. It may be concluded that most of cases were either unapparent forms of LB or insufficiently treated cutaneous forms of this disease.

  14. Snap, Crackle, Pop: Dilational fault breccias record seismic slip below the brittle-plastic transition

    NASA Astrophysics Data System (ADS)

    Melosh, Ben L.; Rowe, Christie D.; Smit, Louis; Groenewald, Conrad; Lambert, Christopher W.; Macey, Paul

    2014-10-01

    Off-fault dynamic tensile cracks form behind an earthquake rupture front with distinct orientation and spacing. These cracks explode the wall rock and create breccias, which we hypothesize will preserve a unique fingerprint of dynamic rupture. Identification of these characteristic breccias may enable a new tool for identifying paleoseismic slip surfaces in the rock record. Using previous experimental and theoretical predictions, we develop a field-based model of dynamic dilational breccia formation. Experimental studies find that secondary tensile fracture networks comprise closely spaced fractures at angles of 70-90° from a slip surface, as well as fractures that branch at angles of ∼30° from a primary mode I fracture. The Pofadder Shear Zone, in Namibia and South Africa, preserves breccias formed in the brittle-ductile transition zone displaying fracture patterns consistent with those described above. Fracture spacing is approximately two orders of magnitude less than predicted by quasi-static models. Breccias are clast-supported, monomict and can display an abrupt transition from fracture network crackle breccia to mosaic breccia textures. Brecciation occurs by the intersection of off-fault dynamic fractures and wall rock fabric; this is in contrast to previous models of fluid pressure gradient-driven failure “implosion breccias”. This mechanism tends to form many similar sized clasts with particle size distributions that may not display self-similarity; where self-similarity is observed the distributions have relatively low D-values of 1.47±0.37, similar to other studies of dynamic processes. We measure slip distances at dilational breccia stepovers, estimating earthquake magnitudes between Mw 2.8-5.8 and associated rupture lengths of 0.023-3.3 km. The small calculated rupture dimensions, in combination with our geologic observations, suggest that some earthquakes nucleated within the quartz-plastic transitional zone and potentially record deep

  15. Polycystic ovary syndrome and obesity do not affect vascular parameters related to early atherosclerosis in young women without glucose metabolism disturbances, arterial hypertension and severe abnormalities of lipid profile.

    PubMed

    Barcellos, Cristiano Roberto Grimaldi; Lage, Silvia Helena Gelás; Rocha, Michelle Patrocínio; Hayashida, Sylvia Asaka Yamashita; Baracat, Edmund Chade; Romano, Angela; Brito, Vinicius Nahime; Marcondes, José Antonio Miguel

    2013-04-01

    The aim of this study was to evaluate the influence of polycystic ovary syndrome (PCOS) and obesity on vascular parameters related to early atherosclerosis (VP-EA) [brachial flow-mediated dilation (FMD), carotid intima-media thickness (CIMT) and carotid arterial compliance (CAC)] in women with minor cardiovascular risk factors (CVRFs). Twenty-five young women with PCOS and 23 eumenorrheic women matched for body mass index (BMI) were studied. The women were subdivided according to BMI and PCOS status, and comparisons were done between PCOS and Control group, regardless of BMI, and between Obese and Lean group, regardless of the presence of PCOS. Insulin resistance was higher in PCOS-group than in control-group and in obese-group than in lean-group. The median of all VP-EA evaluated were similar between PCOS-group and Control-group [FMD: 6.6 versus 8.4% (p = NS); CIMT: 48.0 versus 47.0 mm.10-2 (p = NS); CAC: 6.2 versus 5.6N-1.m4.10-10 (p = NS)] and between obese-group and lean-group [FMD: 7.8 versus 6.6% (p = NS); CIMT: 48.0 versus 47.0 mm.10-2 (p = NS); CAC: 5.7 versus 6.3N-1.m4.10-10 (p = NS)]. These results suggest that PCOS and obesity do not affect VP-EA in women with minor CVRFs.

  16. 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

  17. Aortic Root Dilatation in Mucopolysaccharidosis I–VII

    PubMed Central

    Bolourchi, Meena; Renella, Pierangelo; Wang, Raymond Y.

    2016-01-01

    The prevalence of aortic root dilatation (ARD) in mucopolysaccharidosis (MPS) is not well documented. We investigated aortic root measurements in 34 MPS patients at the Children’s Hospital of Orange County (CHOC). The diagnosis, treatment status, age, gender, height, weight and aortic root parameters (aortic valve annulus (AVA), sinuses of Valsalva (SoV), and sinotubular junction (STJ)) were extracted by retrospective chart review and echocardiographic measurements. Descriptive statistics, ANOVA, and paired post-hoc t-tests were used to summarize the aortic dimensions. Exact binomial 95% confidence intervals (CIs) were constructed for ARD, defined as a z-score greater than 2 at the SoV. The patient age ranged from 3.4–25.9 years (mean 13.3 ± 6.1), the height from 0.87–1.62 meters (mean 1.24 ± 0.21), and the weight from 14.1–84.5 kg (mean 34.4 ± 18.0). The prevalence of dilation at the AVA was 41% (14/34; 95% CI: 25%–59%); at the SoV was 35% (12/34; 95% CI: 20%–54%); and at the STJ was 30% (9/30; 95% CI: 15%–49%). The highest prevalence of ARD was in MPS IVa (87.5%). There was no significant difference between mean z-scores of MPS patients who received treatment with hematopoietic stem cell transplantation (HSCT) or enzyme replacement therapy (ERT) vs. untreated MPS patients at the AVA (z = 1.9 ± 2.5 vs. z = 1.5 ± 2.4; p = 0.62), SoV (z = 1.2 ± 1.6 vs. z = 1.3 ± 2.2; p = 0.79), or STJ (z = 1.0 ± 1.8 vs. z = 1.2 ± 1.6; p = 0.83). The prevalence of ARD was 35% in our cohort of MPS I–VII patients. Thus, we recommend screening for ARD on a routine basis in this patient population. PMID:27916847

  18. Retrospective evaluation of antibody index of human parvovirus B19 as a prognostic factor in patients with dilated and ischemic cardiomyopathy.

    PubMed

    Zedtwitz-Liebenstein, Konstantin; Robak, Oliver; Burgmann, Heinz; Frass, Michael

    2013-06-01

    Cardiotropic viral infections are important causative factors in dilated cardiomyopathy. This retrospective study examined the antibody index for human parvovirus B19 in patients suffering from dilated or ischemic cardiomyopathy as a prognostic factor for stable left ventricular function. Blood specimens from 43 patients with the diagnosis of dilated or ischemic cardiomyopathy were analyzed for human parvovirus B19 by polymerase chain reaction (PCR) and enzyme immunoassay kit for qualitative determination of IgG and IgM antibodies. To exclude patients with acute myocarditis, only patients with onset of symptoms more than 4 months previously were included. Patients with dilated cardiomyopathy and a high antibody index showed a significantly better clinical outcome when compared to patients with a low IgG antibody index (8.5 ± 2.4 vs. 3.1 ± 2.6; P = 0.006). There was no significant difference in left ventricular ejection fraction between patients with a high antibody index and patients with a lower antibody index (P = 0.59). The presence of human parvovirus B19 antibodies is associated with protective immunity. A high antibody index seems to be a good prognostic factor for the disease correlating to a relatively stable left ventricular ejection fraction.

  19. 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.

  20. Optical Clocks and Relativity

    NASA Astrophysics Data System (ADS)

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

    2010-09-01

    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.

  1. [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.

  2. Regulation of native collateral vessel dilation after coronary occlusion in the dog.

    PubMed

    Lamping, K G; Bloom, E N; Harrison, D G

    1994-02-01

    The purpose of this study was to examine mechanisms involved in the response of native collaterals to coronary occlusion. In anesthetized dogs native collaterals were identified as vessels coursing between the left anterior descending and left circumflex arteries using fluorescence angiography. After a left anterior descending occlusion in 12 dogs, collaterals < 100 microns in diameter progressively dilated by 21 +/- 4% (n = 12) 1 min after occlusion and by 39 +/- 6% 15 min after occlusion. Collaterals > 100 microns in diameter did not dilate after coronary occlusion. NG-nitro-L-arginine (1 mg/min intracoronary) caused constriction under basal conditions in collaterals < 100 microns but did not prevent the dilation of collaterals after occlusion. In contrast, glibenclamide (10(-5) M), an inhibitor of ATP-sensitive potassium channels, had no effect on baseline diameter of collaterals < 100 microns diameter but completely prevented dilation of collaterals after occlusion. We conclude that collaterals are not maximally dilated immediately after a coronary occlusion but rather progressively dilate for at least 15 min after an occlusion. This dilation of native collaterals after an occlusion is not mediated by release of an endothelium-derived relaxing factor derived from L-arginine but is mediated by activation of ATP-sensitive K+ channels.

  3. 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.

  4. 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.

  5. Mitogenic cardiomyopathy: a lethal neonatal familial dilated cardiomyopathy characterized by myocyte hyperplasia and proliferation.

    PubMed

    Chang, Kenneth T E; Taylor, Glenn P; Meschino, Wendy S; Kantor, Paul F; Cutz, Ernest

    2010-07-01

    Pediatric cardiomyopathies are a heterogenous group of conditions of which dilated cardiomyopathies are the most common clinicomorphologic subtype. However, the etiology and pathogenesis of many cases of dilated cardiomyopathies remain unknown. We describe a series of 5 cases of a rare but clinically and histologically distinctive dilated cardiomyopathy that was uniformly lethal in early infancy. The 5 cases include 2 pairs of siblings. There was parental consanguinity in 1 of the 2 pairs of siblings. Death occurred in early infancy (range, 22-67 days; mean, 42 days) after a short history of general lethargy, decreased feeding, respiratory distress, or cyanosis. There was no specific birth or early neonatal problems. Autopsy revealed congestive cardiac failure and enlarged, dilated hearts with ventricular dilatation more pronounced than atrial dilatation, and endocardial fibroelastosis. Histology showed prominent hypertrophic nuclear changes of cardiac myofibers and markedly increased myocyte mitotic activity including occasional atypical mitoses. Immunohistochemical staining for Mib1 showed a markedly increased proliferative index of 10% to 20%. Ancillary investigations, including molecular studies, did not reveal a primary cause for the cardiomyopathies. This distinctive dilated cardiomyopathy characterized by unusual histologic features of myocyte nuclear hypertrophy and marked mitotic activity is lethal in early infancy. Its occurrence in 2 pairs of siblings suggests familial inheritance. Although the underlying molecular pathogenesis remains to be elucidated, it is important to recognize this distinctive entity for purposes of genetic counseling.

  6. Laparoscopic Heller Myotomy for Non-Dilated Esophageal Achalasia in Children with Intraoperative Stepped Dilation Under Image Guidance: Attempting Complete Myotomy.

    PubMed

    Miyano, Go; Miyake, Hiromu; Koyama, Mariko; Morita, Keiichi; Kaneshiro, Masakatsu; Nouso, Hiroshi; Yamoto, Masaya; Fukumoto, Koji; Urushihara, Naoto

    2016-05-01

    This study presents a modified surgical approach to laparoscopic myotomy for achalasia using stepped dilation with a Rigiflex balloon and contrast medium under image guidance. A 10-year-old boy with persistent dysphagia and vomiting had ingested only liquids for 3 months, losing >10 kg in body weight. Barium swallow and esophageal manometry diagnosed esophageal achalasia with mild esophageal dilatation. After failed pneumatic dilatation, laparoscopic Heller myotomy with Dor fundoplication was performed. Prior to surgery, a Rigiflex balloon dilator was placed within the esophagus near the diaphragmatic hiatus. A four-port technique was used, and mobilization of the esophagus was limited to the anterior aspect. A 5-cm Heller myotomy was performed, extending another 2 cm onto the anterior gastric wall. During myotomy, the Rigiflex balloon was serially dilated from 30 to 50 mL, and filled with contrast medium under fluoroscopic image guidance in order to maintain appropriate tension on the esophagus to facilitate myotomy, and to confirm adequate myotomy with sufficient release of lower esophageal sphincter by resecting residual circular muscle fibers. Residual circular muscle fibers can be simultaneously visualized under both fluoroscopic image guidance and direct observation through the laparoscope, and they were cut precisely until the residual notch fully disappeared. Dor fundoplication was completed. The operative time was 180 minutes, and oral intake was started after esophagography on postoperative day 1. As of the 12-month follow-up, the patient has not shown any symptoms, and his postoperative course appeared satisfactory.

  7. Stroke and dilated cardiomyopathy associated with celiac disease

    PubMed Central

    Doğan, Murat; Peker, Erdal; Cagan, Eren; Akbayram, Sinan; Acikgoz, Mehmet; Caksen, Huseyin; Uner, Abdurrahman; Cesur, Yasar

    2010-01-01

    Celiac disease (CD) is manifested by a variety of clinical signs and symptoms that may begin either in childhood or adult life. Neurological symptoms without signs of malabsorption have been observed for a long time in CD. In this report, an 8-year-old girl with CD presented with rarely seen dilated cardiomyopathy and stroke. The girl was admitted with left side weakness. Her medical history indicated abdominal distention, chronic diarrhea, failure to thrive, and geophagia. On physical examination, short stature, pale skin and a grade 2 of 6 systolic murmur were detected. Muscle strength was 0/5 on the left side, and 5/5 on the right side. Coagulation examinations were normal. Tests for collagen tissue diseases were negative. Factor V Leiden and prothrombin GA20210 mutations were negative. Tandem mass spectrophotometry and blood carnitine profiles were normal. Brain magnetic resonance imaging and cerebral angiography showed an infarction area at the basal ganglia level. Examinations of serologic markers and intestinal biopsy revealed CD. We emphasize that in differential diagnosis of ischemic stroke, CD should be kept in mind. PMID:20458770

  8. Fatal proventricular dilatation disease in captive native psittacines in Brazil.

    PubMed

    Donatti, Rogério Venâncio; Resende, Maurício; Ferreira, Francisco Carlos Júnior; Marques, Marcus Vinícius Romero; Ecco, Roselene; Shivaprasad, H L; de Resende, José Sérgio; Martins, Nelson Rodrigo da Silva

    2014-03-01

    An outbreak of proventricular dilatation disease (PDD), a fatal inflammatory disease of psittacines (Aves: Psittaciformes), is described in native Brazilian psittacines. Twenty captive psittacines that died of suspected PDD were necropsied and 10 were submitted to histopathology, reverse transcriptase PCR (RT-PCR), and immunohistochemistry (IHC) for avian bornavirus (ABV). Examined species were one pileated parrot (Pionopsitta pileata), three vinaceous-breasted parrots (Amazona vinacea), two blue-winged macaws (Primolius maracana), one scarlet macaw (Ara macao), one chestnut-fronted macaw (Ara severa), one scaly-headed parrot (Pionus maximiliani), and one red-browed Amazon parrot (Amazona rhodocorytha). Gross examination and histopathology revealed typical PDD lesions in all birds. The presence of ABV was confirmed in four psittacines including one red-browed Amazon parrot, one blue-winged macaw, one scarlet macaw, and one chestnut-fronted macaw. In the red-browed Amazon parrot and in one blue-winged macaw, IHC demonstrated ABV antigens in the nucleus and cytoplasm of cells in various organs. This is the first description of PDD by ABV in Brazilian psittacines and indicates the necessity for adopting a strategic control plan for reducing its impact in native birds.

  9. Familial dilated cardiomyopathy: a worse prognosis compared with sporadic forms.

    PubMed Central

    Csanády, M.; Högye, M.; Kallai, A.; Forster, T.; Szárazajtai, T.

    1995-01-01

    OBJECTIVE--To establish the time of onset of dilated cardiomyopathy (DCM) by review of annual chest x rays, which are obligatory in Hungary. DESIGN--A retrospective survey of chest x rays of a cohort of confirmed cases of DCM, to assess time of onset of cardiomegaly. Clinical course was compared by follow up over a mean of six years from the time of diagnosis. SUBJECTS--240 patients with DCM (31 familial, 209 non-familial). Diagnosis was made by echocardiography in all cases and confirmed by coronary angiography and heart biopsy in some cases. MAIN RESULTS--At diagnosis, the mean age of the patients was 31.8 years in the familial group and 39.6 years in the non-familial group (P < 0.05). The time between the onset of cardiomegaly (cardiothoracic ratio > 0.45) and clinical diagnosis was 8.0 and 10.1 years respectively (P < 0.05). The six year survival was 6% in the familial group and 23% in the non-familial group (P < 0.05). CONCLUSIONS--The familial form of DCM is the more malignant form: it occurs at an earlier age and progresses more rapidly than non-familial DCM. Images PMID:7546997

  10. 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.

  11. 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.

  12. 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.

  13. 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

  14. 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

  15. Genetics and genomics of dilated cardiomyopathy and systolic heart failure.

    PubMed

    Tayal, Upasana; Prasad, Sanjay; Cook, Stuart A

    2017-02-22

    Heart failure is a major health burden, affecting 40 million people globally. One of the main causes of systolic heart failure is dilated cardiomyopathy (DCM), the leading global indication for heart transplantation. Our understanding of the genetic basis of both DCM and systolic heart failure has improved in recent years with the application of next-generation sequencing and genome-wide association studies (GWAS). This has enabled rapid sequencing at scale, leading to the discovery of many novel rare variants in DCM and of common variants in both systolic heart failure and DCM. Identifying rare and common genetic variants contributing to systolic heart failure has been challenging given its diverse and multiple etiologies. DCM, however, although rarer, is a reasonably specific and well-defined condition, leading to the identification of many rare genetic variants. Truncating variants in titin represent the single largest genetic cause of DCM. Here, we review the progress and challenges in the detection of rare and common variants in DCM and systolic heart failure, and the particular challenges in accurate and informed variant interpretation, and in understanding the effects of these variants. We also discuss how our increasing genetic knowledge is changing clinical management. Harnessing genetic data and translating it to improve risk stratification and the development of novel therapeutics represents a major challenge and unmet critical need for patients with heart failure and their families.

  16. 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.

  17. Acetylcholine released by endothelial cells facilitates flow‐mediated dilatation

    PubMed Central

    Wilson, Calum; Lee, Matthew D.

    2016-01-01

    Key points The endothelium plays a pivotal role in the vascular response to chemical and mechanical stimuli.The endothelium is exquisitely sensitive to ACh, although the physiological significance of ACh‐induced activation of the endothelium is unknown.In the present study, we investigated the mechanisms of flow‐mediated endothelial calcium signalling.Our data establish that flow‐mediated endothelial calcium responses arise from the autocrine action of non‐neuronal ACh released by the endothelium. Abstract Circulating blood generates frictional forces (shear stress) on the walls of blood vessels. These frictional forces critically regulate vascular function. The endothelium senses these frictional forces and, in response, releases various vasodilators that relax smooth muscle cells in a process termed flow‐mediated dilatation. Although some elements of the signalling mechanisms have been identified, precisely how flow is sensed and transduced to cause the release of relaxing factors is poorly understood. By imaging signalling in large areas of the endothelium of intact arteries, we show that the endothelium responds to flow by releasing ACh. Once liberated, ACh acts to trigger calcium release from the internal store in endothelial cells, nitric oxide production and artery relaxation. Flow‐activated release of ACh from the endothelium is non‐vesicular and occurs via organic cation transporters. ACh is generated following mitochondrial production of acetylCoA. Thus, we show ACh is an autocrine signalling molecule released from endothelial cells, and identify a new role for the classical neurotransmitter in endothelial mechanotransduction. PMID:27730645

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

    NASA Astrophysics Data System (ADS)

    Scandella, Benjamin P.; Varadharajan, Charuleka; Hemond, Harold F.; Ruppel, Carolyn; Juanes, Ruben

    2011-03-01

    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.

  19. 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

  20. Mathematical modeling of subthreshold resonant properties in pyloric dilator neurons.

    PubMed

    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 (I(Ca)) and calcium-dependent potassium (I(KCa)) 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 (I(h)) and I(Ca) (in association with I(KCa)) are dominant factors on resonant properties at hyperpolarized and depolarized potentials, respectively. Through mathematical analysis, results indicate that I h and I(KCa) affect the resonant properties of PD neurons. However, I(Ca) only has an amplifying effect on the resonance amplitude of these neurons.

  1. 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

  2. Choledochal cyst with bile duct dilatation: sonography and /sup 99m/Tc IDA cholescintigraphy

    SciTech Connect

    Han, B.K.; Babcock, D.S.; Gelfand, M.H.

    1981-06-01

    Three cases of choledochal cyst associated with intrahepatic biliary dilatation are presented. Findings on sonography included a large cystic mass in the porta hepatis separate from the gallbladder; a dilated common hepatic or common bile duct entering directly into the cyst; and smaller cystic masses of dilated central intrahepatic ducts. All three patients underwent operation with intraoperative cholangiography. Two patients had /sup 99m/Tc IDA cholescintigraphy which confirmed the diagnosis of choledochal cyst by demonstrating filling of the cyst with stasis and delayed intestinal activity. The accurate preoperative diagnosis of choledochal cyst, made by sonography combined with /sup 99m/Tc IDA cholescintigraphy, obviated invasive studies.

  3. Dilatational viscosity of dilute particle-laden fluid interface at different contact angles

    NASA Astrophysics Data System (ADS)

    Lishchuk, Sergey V.

    2016-12-01

    We consider a solid spherical particle adsorbed at a flat interface between two immiscible fluids and having arbitrary contact angle at the triple contact line. We derive analytically the flow field corresponding to dilatational surface flow in the case of a large ratio of dynamic shear viscosities of two fluids. Considering a dilute assembly of such particles we calculate numerically the dependence on the contact angle of the effective surface dilatational viscosity particle-laden fluid interface. The effective surface dilatational viscosity is proportional to the size and surface concentration of particles and monotonically increases with the increase in protrusion of particles into the fluid with larger shear viscosity.

  4. [Treatment of atresia ani type I by balloon dilatation in 5 kittens and one puppy].

    PubMed

    Tomsa, K; Major, A; Glaus, T M

    2011-06-01

    Atresia ani is the most common anorectal anomaly in small animals. In the present study, an anal stricture (atresia ani type I) in five 3 to 8 weeks old kittens and one 4 month old puppy was treated by balloon dilation. In 4 kittens and the puppy the stricture was eliminated permanently and without complications by a single intervention. Only the smallest kitten with the most severe stenosis developed a rectal fistula as a complication of repeated balloon dilation, which necessitated surgical correction. Balloon dilation proved to be an efficient therapeutic method for anal atresia type I, and can be recommended as the treatment of choice.

  5. 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

  6. Effects of sodium nitrite supplementation on vascular function and related small metabolite signatures in middle-aged and older adults

    PubMed Central

    Johnson, Lawrence C.; Brooks, Forrest A.; Evans, Trent D.; Justice, Jamie N.; Cruickshank-Quinn, Charmion; Reisdorph, Nichole; Bryan, Nathan S.; McQueen, Matthew B.; Santos-Parker, Jessica R.; Chonchol, Michel B.; Bassett, Candace J.; Sindler, Amy L.; Giordano, Tony; Seals, Douglas R.

    2015-01-01

    Insufficient nitric oxide (NO) bioavailability plays an important role in endothelial dysfunction and arterial stiffening with aging. Supplementation with sodium nitrite, a precursor of NO, ameliorates age-related vascular endothelial dysfunction and arterial stiffness in mice, but effects on humans, including the metabolic pathways altered, are unknown. The purpose of this study was to determine the safety, feasibility, and efficacy of oral sodium nitrite supplementation for improving vascular function in middle-aged and older adults and to identify related circulating metabolites. Ten weeks of sodium nitrite (80 or 160 mg/day, capsules, TheraVasc; randomized, placebo control, double blind) increased plasma nitrite acutely (5- to 15-fold, P < 0.001 vs. placebo) and chronically (P < 0.10) and was well tolerated without symptomatic hypotension or clinically relevant elevations in blood methemoglobin. Endothelial function, measured by brachial artery flow-mediated dilation, increased 45-60% vs. baseline (P < 0.10) without changes in body mass or blood lipids. Measures of carotid artery elasticity (ultrasound and applanation tonometry) improved (decreased β-stiffness index, increased cross-sectional compliance, P < 0.05) without changes in brachial or carotid artery blood pressure. Aortic pulse wave velocity was unchanged. Nitrite-induced changes in vascular measures were significantly related to 11 plasma metabolites identified by untargeted analysis. Baseline abundance of multiple metabolites, including glycerophospholipids and fatty acyls, predicted vascular changes with nitrite. This study provides evidence that sodium nitrite supplementation is well tolerated, increases plasma nitrite concentrations, improves endothelial function, and lessens carotid artery stiffening in middle-aged and older adults, perhaps by altering multiple metabolic pathways, thereby warranting a larger clinical trial. PMID:26607249

  7. Whole exome sequencing identifies a troponin T mutation hot spot in familial dilated cardiomyopathy.

    PubMed

    Campbell, Nzali; Sinagra, Gianfranco; Jones, Kenneth L; Slavov, Dobromir; Gowan, Katherine; Merlo, Marco; Carniel, Elisa; Fain, Pamela R; Aragona, Pierluigi; Di Lenarda, Andrea; Mestroni, Luisa; Taylor, Matthew R G

    2013-01-01

    Dilated cardiomyopathy (DCM) commonly causes heart failure and shows extensive genetic heterogeneity that may be amenable to newly developed next-generation DNA sequencing of the exome. In this study we report the successful use of exome sequencing to identify a pathogenic variant in the TNNT2 gene using segregation analysis in a large DCM family. Exome sequencing was performed on three distant relatives from a large family with a clear DCM phenotype. Missense, nonsense, and splice variants were analyzed for segregation among the three affected family members and confirmed in other relatives by direct sequencing. A c.517T C>T, Arg173Trp TNNT2 variant segregated with all affected family members and was also detected in one additional DCM family in our registry. The inclusion of segregation analysis using distant family members markedly improved the bioinformatics filtering process by removing from consideration variants that were not shared by all affected subjects. Haplotype analysis confirmed that the variant found in both DCM families was located on two distinct haplotypes, supporting the notion of independent mutational events in each family. In conclusion, an exome sequencing strategy that includes segregation analysis using distant affected relatives within a family represents a viable diagnostic strategy in a genetically heterogeneous disease like DCM.

  8. Whole Exome Sequencing Identifies a Troponin T Mutation Hot Spot in Familial Dilated Cardiomyopathy

    PubMed Central

    Campbell, Nzali; Sinagra, Gianfranco; Jones, Kenneth L.; Slavov, Dobromir; Gowan, Katherine; Merlo, Marco; Carniel, Elisa; Fain, Pamela R.; Aragona, Pierluigi; Di Lenarda, Andrea; Mestroni, Luisa; Taylor, Matthew R. G.

    2013-01-01

    Dilated cardiomyopathy (DCM) commonly causes heart failure and shows extensive genetic heterogeneity that may be amenable to newly developed next-generation DNA sequencing of the exome. In this study we report the successful use of exome sequencing to identify a pathogenic variant in the TNNT2 gene using segregation analysis in a large DCM family. Exome sequencing was performed on three distant relatives from a large family with a clear DCM phenotype. Missense, nonsense, and splice variants were analyzed for segregation among the three affected family members and confirmed in other relatives by direct sequencing. A c.517T C>T, Arg173Trp TNNT2 variant segregated with all affected family members and was also detected in one additional DCM family in our registry. The inclusion of segregation analysis using distant family members markedly improved the bioinformatics filtering process by removing from consideration variants that were not shared by all affected subjects. Haplotype analysis confirmed that the variant found in both DCM families was located on two distinct haplotypes, supporting the notion of independent mutational events in each family. In conclusion, an exome sequencing strategy that includes segregation analysis using distant affected relatives within a family represents a viable diagnostic strategy in a genetically heterogeneous disease like DCM. PMID:24205113

  9. Evolution of dilated cardiomyopathy (DCM) from idiopathic hypertrophic cardiomyopathy (IHCM) vs. inflammatory dilated cardiomyopathy (DCMi): a rare case of sudden death in an 8-year-old boy.

    PubMed

    Dettmeyer, Reinhard; Schmidt, Peter; Kandolf, Reinhard; Madea, Burkhard

    2004-01-01

    In rare cases, the diagnosis of hypertrophic and dilated cardiomyopathy (DCM) in children was established postmortem. Our case report deals with the sudden and unexpected death of an 8-year-old boy. The postmortem examination revealed non-obstructive hypertrophy with irregular arrangement of muscular fibers, dilatation of the ventricles, endocardial fibrosis, microfocal vacuolization with enlarged hyperchromatic nuclei, and signs of inflammation with interstitial fibrosis. We present an evolution from idiopathic cardiomyopathy to DCM. To some extent, there were morphologic signs of an inflammatory process that first led us to suspect a specific inflammatory DCM.

  10. A theoretical derivation of the dilatancy equation for brittle rocks based on Maxwell model

    NASA Astrophysics Data System (ADS)

    Li, Jie; Huang, Houxu; Wang, Mingyang

    2017-01-01

    In this paper, the micro-cracks in the brittle rocks are assumed to be penny shaped and evenly distributed; the damage and dilatancy of the brittle rocks is attributed to the growth and expansion of numerous micro-cracks under the local tensile stress. A single crack's behaviour under the local tensile stress is generalized to all cracks based on the distributed damage mechanics. The relationship between the local tensile stress and the external loading is derived based on the Maxwell model. The damage factor corresponding to the external loading is represented using the p-alpha (p-α) model. A dilatancy equation that can build up a link between the external loading and the rock dilatancy is established. A test of dilatancy of a brittle rock under triaxial compression is conducted; the comparison between experimental results and our theoretical results shows good consistency.

  11. 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.

  12. Choledochal cyst with bile duct dilatation: sonography and /sup 99/mTc IDA cholescintigraphy

    SciTech Connect

    Han, B.K.; Babcock, D.S.; Gelfand, M.H.

    1981-06-01

    Three cases of choledochal cyst associated with intrahepatic biliary dilatation are presented. Findings on sonography included a large cystic mass in the porta hepatis separate from the gallbladder; a dilated common hepatic or common bile duct entering directly into the cyst; the smaller cystic masses of dilated central intrahepatic ducts. The dilatation of the central intrahepatic bile ducts was moderate in two patients and massive in one patient. All three patients underwent operation with intraoperative cholangiography. Two patients had /sup 99/mTc IDA cholescintigraphy which confirmed the diagnosis of choledochal cyst by demonstrating filling of the cyst with stasis and delayed intestinal activity. The accurate preoperative diagnosis of choledochal cyst, made by sonography combined with /sup 99/mTc IDA cholescintigraphy, obviated invasive studies.

  13. 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.

  14. Clinical outcome, valve dysfunction, and progressive aortic dilation in a pediatric population with isolated bicuspid aortic valve.

    PubMed

    Spaziani, Gaia; Ballo, Piercarlo; Favilli, Silvia; Fibbi, Veronica; Buonincontri, Lorenzo; Pollini, Iva; Zuppiroli, Alfredo; Chiappa, Enrico

    2014-06-01

    The aim of this study was to explore the medium-term clinical outcome and the risk of progression of aortic valve disease and aortic dilation in pediatric patients with isolated bicuspid aortic valve (BAV). 179 pediatric patients with isolated BAV were prospectively followed from January 1995 to December 2010. Patients with severe valve dysfunction at baseline were excluded. Clinical outcome included cardiac death, infective endocarditis, aortic complications, cardiac surgery and percutaneous valvuloplasty. Echocardiographic endpoints were: progression of aortic stenosis (AS) or regurgitation (AR) and progressive aortic enlargement at different levels of the aortic root, evaluated as z-score. The median age at diagnosis was 7.8 [2.7-12.0] years. After a median followup of 5.4 [2.3-9.2] years, all patients were alive. The clinical endpoint occurred in 4 (2.2 %) patients (0.41 events per 100 patient-years). A progression of AS and AR was observed in 9 (5.0 %) and 29 (16.2 %) patients, respectively. The z-scores at the end of follow-up were not significantly different from baseline at the annulus, Valsalva sinuses and sinotubular junction, whereas a slight increase was observed at the level of the ascending aorta (1.9 vs 1.5, p = 0.046). Significant progressive aortic dilation occurred in a minority of patients (10.6, 5.6, 9.5, and 19.0 % respectively). The clinical outcome in pediatric patients with isolated BAV is favourable and the progression of aortic valve dysfunction and aortic dilation is relatively slow. These findings may be taken into account to better guide risk assessment and clinical follow-up in these patients.

  15. LMNA mutations in Polish patients with dilated cardiomyopathy: prevalence, clinical characteristics, and in vitro studies

    PubMed Central

    2013-01-01

    Background LMNA mutations are most frequently involved in the pathogenesis of dilated cardiomyopathy with conduction disease. The goal of this study was to identify LMNA mutations, estimate their frequency among Polish dilated cardiomyopathy patients and characterize their effect both in vivo and in vitro. Methods Between January, 2008 and June, 2012 two patient populations were screened for the presence of LMNA mutations by direct sequencing: 66 dilated cardiomyopathy patients including 27 heart transplant recipients and 39 dilated cardiomyopathy patients with heart failure referred for heart transplantation evaluation, and 44 consecutive dilated cardiomyopathy patients, referred for a family evaluation and mutation screening. Results We detected nine non-synonymous mutations including three novel mutations: p.Ser431*, p.Val256Gly and p.Gly400Argfs*11 deletion. There were 25 carriers altogether in nine families. The carriers were mostly characterized by dilated cardiomyopathy and heart failure with conduction system disease and/or complex ventricular arrhythmia, although five were asymptomatic. Among the LMNA mutation carriers, six underwent heart transplantation, fourteen ICD implantation and eight had pacemaker. In addition, we obtained ultrastructural images of cardiomyocytes from the patient carrying p.Thr510Tyrfs*42. Furthermore, because the novel p.Val256Gly mutation was found in a sporadic case, we verified its pathogenicity by expressing the mutation in a cellular model. Conclusions In conclusion, in the two referral centre populations, the screening revealed five mutations among 66 heart transplant recipients or patients referred for heart transplantation (7.6%) and four mutations among 44 consecutive dilated cardiomyopathy patients referred for familial evaluation (9.1%). Dilated cardiomyopathy patients with LMNA mutations have poor prognosis, however considerable clinical variability is present among family members. PMID:23702046

  16. Transformation of myocarditis and inflammatory cardiomyopathy to idiopathic dilated cardiomyopathy: facts and fiction.

    PubMed

    Figulla, Hans R

    2004-05-01

    There is broad evidence that enteroviruses and adenoviruses can induce an acute inflammation of the myocardium without cardiac dysfunction (i.e. myocarditis) or with cardiac dysfunction (i.e. inflammatory cardiomyopathy) that can transform to a virus-negative dilated cardiomyopathy. In the adult patient neither other viruses (parvo-B 19 virus, hepatitis C virus, cytomegalovirus) nor post-infection autoimmunity are likely to induce idiopathic dilated cardiomyopathy.

  17. [Pregnancy-conditioned dilatation of the calyceal system-sonographic diagnosis and urologic control (author's transl)].

    PubMed

    Bernaschek, G; Kratochwil, A

    1981-03-01

    Ultrasonic diagnosis provides the possibility without any irradiation hazards to follow-up the urinary excreting system in pregnancies as often as necessary. Thus it becomes possible to detect the true percentages of pregnant women with dilatation of the calyceal system, and to evaluate the course of dilatation in those women examined at different intervals. There exists as well the possibility to avoid urinary tract infections by an intensive urologic surveillance in such cases.

  18. Percutaneous drainage of gastric remnant dilatation after laparoscopic Roux-en-Y gastric bypass.

    PubMed

    Bibyan, M; Khandelwal, R G; Parmar, A K; Reddy, P K

    2012-05-01

    Roux-en-Y gastric bypass is a commonly performed bariatric procedure worldwide. Gastric remnant dilatation is an uncommon early complication of this procedure that can be fatal if treatment is delayed, as it can cause peritonitis and death. Herein we report a gastric bypass patient who presented with profound shock 3 months after the surgery. After resuscitation and evaluation, she was diagnosed as having a massive dilatation of gastric remnant, which we managed with percutaneous drainage.

  19. Segmental Dilatation of Intestine Presenting as Partial Intestinal Obstruction in a Child

    PubMed Central

    Khemakhem, Rachid; Elhassan, Elbager Othman

    2014-01-01

    Segmental dilatation of the intestine in pediatric age group is a rare entity. Patients usually present with partial intestinal obstruction which may delay surgical decision. Our case was an 18-month-old girl, who presented with partial intestinal obstruction, provisionally diagnosed as a case of Hirschsprung’s disease. Diagnostic evaluation with contrast study gave a clue of small intestinal obstruction with a dilated segment. PMID:25057472

  20. 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.

  1. Transcatheter pulmonary valve perforation and balloon dilatation in neonates with pulmonary atresia and intact ventricular septum

    PubMed Central

    Gerestein, C.G.; Berger, R.M.F.; Dalinghaus, M.; Bogers, A.J.J.C.; Witsenburg, M.

    2003-01-01

    Background Pulmonary atresia and intact ventricular septum is characterised by a great morphological variety. Treatment is not uniform. Objective To evaluate our experience with transcatheter valvotomy and balloon dilatation in neonates with pulmonary atresia and intact ventricular septum. Design Retrospective. Methods Between January 1997 and September 2000 five neonates with pulmonary atresia and intact ventricular septum underwent transcatheter valvotomy and balloon dilatation. Results The catheter intervention was performed at a mean age of 27 days (range 3-95 days). The atretic pulmonary valve was successfully perforated in all neonates. Subsequent balloon dilatation was successful in four neonates. Balloon dilatation was unsuccessful in one patient, who underwent an elective surgical valvotomy of the pulmonary valve after five days. Three patients needed a modified Blalock-Taussig shunt after a mean of 23 days. Four patients required repeated balloon dilatation after a mean of 227 days. Mean follow-up was 2.7 years (range 1-5 years). Conclusions Transcatheter perforation of the pulmonary valve membrane and balloon dilatation is a good, safe initial therapy in selected neonates with pulmonary atresia and intact ventricular septum. This procedure can prevent open-heart surgery in these patients in the first months of life. ImagesFigure 1Figure 2 PMID:25696158

  2. Surface dilational moduli of poly (ethylene oxide), poly (methyl methacrylate), and their blend films.

    PubMed

    Kato, Satoaki; Kawaguchi, Masami

    2012-10-15

    Surface dilational moduli of poly (ethylene oxide) (PEO), poly (methyl methacrylate) (PMMA), and compatible PEO/PMMA blend films spread at the air-water interface were investigated as a function of surface concentration. The surface dilational modulus of an expanded PEO film increased as the surface concentration increased to 0.4 mg/m(2), which corresponds to the limiting surface area of PEO. After peaking at this value, the surface dilational modulus decreased with an increase in the PEO concentration. Lissajous orbits of PEO films exhibited positive hysteresis loops for all surface concentration ranges. On the other hand, the surface dilational modulus of a condensed PMMA film steeply increased as the surface concentration increased. Lissajous orbits of PMMA films changed from positive hysteresis loops to negative loops at the surface concentration at which the surface pressure reached in the plateau region. The magnitude of the surface dilational modulus of PMMA was larger than that of PEO at a fixed surface concentration. The surface dilational moduli of the PEO/PMMA blend films increased with the total surface concentration and their magnitudes were less than those of the individual PMMA films and larger than those of the individual PEO films at fixed surface concentrations. Lissajous orbits of the PEO/PMMA blend films also changed from positive hysteresis loops to negative loops beyond the surface concentration at which the plateau surface pressure of PEO was attained.

  3. Left ventriculoplasty for dilated cardiomyopathy in Fukuyama-type muscular dystrophy.

    PubMed

    Yoda, Masataka; Tanabe, Hiroaki; Nishino, Ichizo; Suma, Hisayoshi

    2011-08-01

    A 29-year-old man was hospitalized because of heart failure causing dilated cardiomyopathy (DCM). On admission, he had elevated creatinine kinase levels (hyper CKemia) (4283IUl⁻) and false enlargement of bilateral calves. By a muscular biopsy, he was diagnosed as Fukuyama-type muscular dystrophy. Although neuromuscular diseases are often related to cardiomyopathy, reports showing a relation between cardiomyopathy and Fukuyama-type muscular dystrophy have been rare. Our group performed the partial left venticulectomy of the posterior wall and approximation of the papillary muscle, mitral valve annuloplasty, and tricuspid valve annuloplasty for DCM in the patient with Fukuyama-type muscular dystrophy, after obtaining informed consent from the patient and his family. At the 1-year follow-up examination, the neuromuscular symptoms had not progressed, and the left ventricular function was improved (left ventricular end-diastolic dimension (LVDd) 77-66 mm, left ventricular end-systolic dimension (LVDs) 73-59 mm, and ejection fraction (EF) 26-30%). This is the first case report of a left ventriculoplasty in a patient with Fukuyama-type muscular dystrophy.

  4. Dilated Cardiomyopathy: Normalized Multiparametric Myocardial Strain Predicts Contractile Recovery

    PubMed Central

    Henn, Matthew C.; Lawrance, Christopher P.; Kar, Julia; Cupps, Brian P.; Kulshrestha, Kevin; Koerner, Danielle; Wallace, Kathleen; Joseph, Susan; Ewald, Greg; Pasque, Michael K.

    2015-01-01

    Background Left ventricular (LV) contractile injury in dilated cardiomyopathy (DCM) may occur in a consistently heterogeneous distribution, suggesting that early injury “sentinel” regions may have prognostic significance. Heightened surveillance of these regions with high-resolution contractile metrics may predict recovery in DCM. Methods Multiple 3D strain parameters were calculated at each of 15,300 LV grid-points from systolic displacement data obtained from cardiac MRI in 124 test subjects. In 24 DCM patients, z-scores for two strain parameters at each grid-point were calculated by comparison of patient-specific strain values to respective point-specific mean and standard deviation values from a normal human strain database (n=100). Multiparametric strain z-scores were averaged over 6 LV regions at basilar, mid, and apical levels (18 sub-regions). DCM patients were stratified into 3 groups based on a blinded review of clinical contractile recovery (complete[n=7]; incomplete[n=7]; none[n=10]). Results Basilar-septal sub-regions were consistently heavily injured. Basilar-septal z-scores were significantly larger (worse) than those for the rest of the LV (2.73±1.27 vs 2.22±0.83; p=0.011) and lateral wall (2.73±1.27 vs 1.44±0.72; p<0.001). All patients with sentinel region average multiparametric strain z-scores <2 standard deviations (n=6) experienced complete recovery, while 17/18 DCM patients with z-scores >2 standard deviations experienced incomplete or no contractile recovery. Conclusions Contractile injury in DCM is heterogeneous with basilar-septal regions injured more than lateral regions. The targeting of early-injury sentinel regions for heightened surveillance with high-resolution metrics of micro-regional contractile function may accurately predict recovery on medical therapy. A 2 standard deviation z-score threshold may predict contractile recovery. PMID:26228597

  5. 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

  6. Spreading dilatation to luminal perfusion of ATP and UTP in rat isolated small mesenteric arteries

    PubMed Central

    Winter, Polly; Dora, Kim A

    2007-01-01

    Levels of ATP achieved within the lumen of vessels suggest a key autacoid role. P2Y receptors on the endothelium may represent the target for ATP, leading to hyperpolarization and associated relaxation of vascular smooth muscle through the endothelium-dependent hyperpolarizing factor (EDHF) pathway. EDHF signals radially from the endothelium to cause dilatation, and appears mechanistically distinct from the axial spread of dilatation, which we showed occurs independently of a change in endothelial cell Ca2+ in rat mesenteric arteries. Here we have investigated the potential of P2Y receptor stimulation to evoke spreading dilatation in rat resistance small arteries under physiological pressure and flow. Triple cannulation of isolated arteries enables focal application of purine and pyrimidine nucleotides to the endothelium, avoiding potential complicating actions of these agents on the smooth muscle. Nucleotides were locally infused through one branch of a bifurcation, causing near maximal local dilatation attributable to EDHF. Dilatation then spread rapidly into the adjacent feed artery and upstream against the direction of luminal flow, sufficient to increase flow into the feed artery. The rate of decay of this spreading dilatation was identical between nucleotides, and matched that to ACh, which acts only on the endothelium. In contrast, focal abluminal application of either ATP or UTP at the downstream end of cannulated arteries evoked constriction, which only in the case of ATP was also associated with modest spread of dilatation. The non-hydrolysable ADP analogue, ADPβS, acting at P2Y1 receptors, caused robust local and spreading dilatation responses whether applied to the luminal or abluminal surface of pressurized arteries. Dilatation to nucleotides was sensitive to inhibition with apamin and TRAM-34, selective blockers of small- and intermediate-conductance Ca2+-activated K+ channels, respectively. These data demonstrate that direct luminal stimulation of P

  7. 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

  8. 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

  9. Association of tumor necrosis factor-α gene G-308A polymorphism with dilated cardiomyopathy: a meta-analysis.

    PubMed

    Luo, Rong; Li, Xiaoping; Fan, Xiongwei; Yuan, Wuzhou; Wu, Xiushan

    2013-03-01

    Published data on the association between tumor necrosis factor-α (TNF-α) G-308A gene polymorphism and dilated cardiomyopathy (DCM) risk are inconclusive. To clarify the association of TNF-α G-308A gene polymorphism and DCM, a meta-analysis of case-control studies was performed. Some databases, such as PubMed and Embase, were searched to indentify related studies. Search terms included dilated cardiomyopathy, tumor necrosis factor-alpha or TNF-α or TNF alpha or tumor necrosis factor alpha, and polymorphism or mutation. Eight case-control studies involving 1487 DCM cases and 1734 normal controls were included in the meta-analysis to assess the purported association between the TNF-α G-308A gene polymorphism and the risk of DCM. A dominant genetic model was used and the comparison of GA/AA genotype versus GG genotype was performed in the present meta-analysis. The odds ratio was 1.42 (95% confidence interval: 1.05, 1.93, P=0.02), manifesting frequency of the TNF-α-308 GA/AA genotype was higher in DCM patients than the control group. TNF-α G-308A nucleotide transition might be associated with the risk of DCM.

  10. A novel locus for autosomal-dominant dilated cardiomyopathy maps to chromosome 7q22.3-31.1.

    PubMed

    Schönberger, Jost; Kühler, Leif; Martins, Elisabete; Lindner, Tom H; Silva-Cardoso, Jose; Zimmer, Michael

    2005-12-01

    Inherited dilated cardiomyopathy (DCM) is a genetically and phenotypically very heterogeneous disease. DCM is caused by mutations in multiple genes encoding proteins that are involved in force generation, force transmission, energy production and several signalling pathways. Thus, the pathophysiology of heart failure is complex and not yet fully understood. Familial forms of DCM let the way to identify new key proteins by positional cloning and to study respective pathomechanisms that are critical for normal cardiac function, but may not have been correlated with heart disease before. Here we report a three-generation pedigree including 16 individuals affected by dilated cardiomyopathy without additional phenotypes. The pedigree is consistent with autosomal-dominant inheritance and age-related penetrance. A genome-wide linkage analysis excluded linkage to all known DCM genes and loci, whereas several close markers on chromosome 7q22.3-31.1 segregated with the disease (maximum logarithm of odds score, 4.20 at D7S471 and D7S501). The disease causing mutation lies in a 9.73 Mb interval between markers D7S2545 and D7S2554 that contains no known cytoskeletal genes. Coding exons of the candidate genes LAMB1, LAMB4 and PIK3CG were screened but no mutations were identified.

  11. Regional evidence of modulation of cardiac adiponectin level in dilated cardiomyopathy: pilot study in a porcine animal model

    PubMed Central

    2012-01-01

    Background The role of systemic and myocardial adiponectin (ADN) in dilated cardiomyopathy is still debated. We tested the regulation of both systemic and myocardial ADN and the relationship with AMP-activated protein kinase (AMPK) activity in a swine model of non-ischemic dilated cardiomyopathy. Methods and results Cardiac tissue was collected from seven instrumented adult male minipigs by pacing the left ventricular (LV) free wall (180 beats/min, 3 weeks), both from pacing (PS) and opposite sites (OS), and from five controls. Circulating ADN levels were inversely related to global and regional cardiac function. Myocardial ADN in PS was down-regulated compared to control (p < 0.05), yet ADN receptor 1 was significantly up-regulated (p < 0.05). No modifications of AMPK were observed in either region of the failing heart. Similarly, myocardial mRNA levels of PPARγ, PPARα, TNFα, iNOS were unchanged compared to controls. Conclusions Paradoxically, circulating ADN did not show any cardioprotective effect, confirming its role as negative prognostic biomarker of heart failure. Myocardial ADN was reduced in PS compared to control in an AMPK-independent fashion, suggesting the occurrence of novel mechanisms by which reduced cardiac ADN levels may regionally mediate the decline of cardiac function. PMID:23164042

  12. Chronic alcohol consumption from adolescence-to-adulthood in mice - hypothalamic gene expression changes in the dilated cardiomyopathy signaling pathway

    PubMed Central

    2014-01-01

    Background Adolescence is a developmental stage vulnerable to alcohol drinking-related problems and the onset of alcoholism. Hypothalamus is a key brain region for food and water intake regulation, and is one of the alcohol-sensitive brain regions. However, it is not known what would be the alcohol effect on hypothalamus following adolescent alcohol intake, chronically over the adolescent development, at moderate levels. Results We employed a paradigm of chronic moderate alcohol intake from adolescence-to-adulthood in mice, and analyzed the alcohol effect on both behavioral and hypothalamic gene expression changes. A total of 751 genes were found and subjected to pathway analysis. The dilated cardiomyopathy (DCM) pathway was identified. The changes of ten genes under this pathway were further verified using RT-PCR. Chronic alcohol consumption during adolescence, even at moderate levels, led to a decrease of motor activity in mice, and also a concerted down regulation of signaling pathway initiating factor (SPIF) genes in the DCM signaling pathway, including β1-adrenergic receptor (Adrb1), Gs protein (Gnas), adenylyl cyclase 1 (Adcy1), and dihydropyridine receptor/L-type calcium channel (Cacna1d). Conclusions These findings suggest that adolescent alcohol intake may trigger gene expression changes in the CNS that parallel those found in the dilated cardiomyopathy signaling pathway. If such effects also take place in humans, our findings would serve as a warning against alcohol intake in youth, such as by teens and/or college students. PMID:24884436

  13. 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.

  14. From mode I cracking to dilatancy, shear, and compaction banding: Constraints from axisymmetric and poly-axial experiments and numerical models

    NASA Astrophysics Data System (ADS)

    Chemenda, A. I.; Jorand, C.; Petit, J.; Nguyen, S.

    2011-12-01

    Dilatancy bands were recently obtained in conventional axisymmetric extension tests on a synthetic physical rock analogue (granular, frictional, cohesive and dilatant) material GRAM1 at a relatively low mean stress σ within range σd < σ < σs , where σd and σs are experimentally constrained values (Chemenda et al., JGR, 2011). The walls of the opened bands have plumose morphology defined by the decohesion pattern of the material within the band, which have a complex 3-D structure. At σ < σd , the sample rupture occurs through mode I cracking and results in smooth fracture surfaces. With σ increase at σ > σs , the bands become inclined to σ1 , resulting in dilatant shear and then in compactive shear bands that have an irregular structure and geometry at a micro-scale. Pure compaction bands were not obtained (at least not evidenced) in the extension tests, but they were generated in the GRAM1 compression tests as previously in the porous rocks. At lower pressure in the compression tests were obtained compactive shear and dilatant shear bands as well as axial splitting fractures that could be originated as dilatancy bands. We also present results from poly-axial tests conducted with material GRAM2 that have slightly different properties than GRAM1. The parallelepiped GRAM2 samples are first subject to the isotropic stress σ0 and then to the uniaxial unloading under plane-strain conditions. At some stage of this process, the sample loses stability and is affected by regular networks of localization bands/fractures whose spacing depends on the loading conditions. The band type changes with the initial mean stress σ0 in the same way as in the above axisymmetric tests where normally only one band is formed. The angle ψ between the bands and σ1 direction continuously increases with σ0 . At sufficiently low σ0 , ψ = 0, which corresponds to the dilatancy bands. Their borders bear plumose features very similar to those on natural joint surfaces. Different

  15. Pulmonary Artery Dilation and Right Ventricular Function in Acute Kawasaki Disease.

    PubMed

    Numano, Fujito; Shimizu, Chisato; Tremoulet, Adriana H; Dyar, Dan; Burns, Jane C; Printz, Beth F

    2016-03-01

    Coronary artery inflammation and aneurysm formation are the most common complications of Kawasaki disease (KD). Valvulitis and myocarditis are also well described and may lead to valvar regurgitation and left ventricular dysfunction. However, functional changes in the right heart have rarely been reported. We noted several acute KD patients with dilated pulmonary arteries (PA) and thus sought to systematically characterize PA size and right-heart function in an unselected cohort of KD patients cared for at a single clinical center. Clinical, laboratory, and echocardiographic data from 143 acute KD subjects were analyzed. PA dilation was documented in 23 subjects (16.1 %); these subjects had higher median right ventricle myocardial performance index (RV MPI), higher ratio of early tricuspid inflow velocity to tricuspid annular early diastolic velocity (TV E/e'), and lower median TV e' velocity compared to the non-PA dilation group (0.50 vs 0.38 p < 0.01, 4.2 vs 3.6 p < 0.05, and 13.5 vs 15.2 cm/s p < 0.01, respectively). Almost all subjects with PA dilation had improved PA Z-score, RV MPI, and TV E/e' in the subacute phase (p < 0.01). There were no significant differences in indices of left ventricle function between PA dilation group and non-PA dilation group. In summary, PA dilation was documented in 16 % of acute KD subjects. These subjects were more likely to have echocardiographic indices consistent with isolated RV dysfunction that improved in the subacute phase. The long-term consequence of these findings will require longitudinal studies of this patient population.

  16. 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.

  17. 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.

  18. Inflammation and glandular duct dilatation of the tongue from patients with chronic Chagas disease.

    PubMed

    de Lima Pereira, Sanívia Aparecida; Rodrigues, Denise Bertulucci Rocha; da Fonseca Ferraz, Mara Lúcia; da Cunha Castro, Eumenia Costa; dos Reis, Marlene Antonia; de Paula Antunes Teixeira, Vicente

    2006-01-01

    The purpose of this study was to evaluate morphologically the tongue of individuals with chronic Chagas disease (CD) in comparison to the non-chagasic ones. Twenty-four protocol cases of autopsies were selected. They were subdivided into CD patients (10 cases) and non-chagasic ones (14 cases). The morphometric analysis was accomplished for the tongue muscle and salivary glands duct lumen area. In three CD patients, perineuritis was found, and two of them showed megaesophagus and megacolon. The intensity of the inflammation in the von Ebner's glands, the tongue muscles, and the salivary glands duct lumen area was significantly higher in the CD patients. We concluded that the CD patients show salivary glands duct dilatation, which probably would have a relation with alterations in the autonomic nervous system. The inflammation found in CD patients is in accordance with that described in comparative studies on the digestive tract and heart. These morphological findings suggest that the histopathological analysis of the tongue associated with other organs, or even in an isolated manner, can add in the diagnosis and pathogenesis of the CD chronic phase.

  19. Percutaneous dilational and surgical tracheostomy in burn patients: incidence of complications and dysphagia.

    PubMed

    Smailes, S T; Ives, M; Richardson, P; Martin, R V; Dziewulski, P

    2014-05-01

    The aim of this study is to evaluate the incidence of complications and dysphagia in relation to the timing of tracheostomy and tracheostomy technique in 49 consecutive adult burn patients. We analysed prospectively collected data. Bronchoscopy was used to diagnose tracheal stenosis and a modified Evans blue dye test was used to diagnose dysphagia. Eighteen patients received a percutaneous dilatational tracheostomy (PDT) and thirty-one patients received an open surgical tracheostomy (OST). Eight patients developed significant complications (16%) following tracheostomy, there is no difference in the incidence of complications; post op infection, stoma infection or tracheal stenosis between PDT and OST groups. Patients with full thickness neck burn who developed complications had a tracheostomy significantly earlier following autografting (p=0.05). Failed extubation is associated with dysphagia (p=0.02) whereas prolonged intubation and ventilation prior to tracheostomy independently predicts dysphagia (p=0.03). We conclude that there is no difference in the complication rates for PDT and OST in our burn patients. We recommend early closure of neck burns and tracheostomy through fully adherent autograft or at least 10 days after grafting to reduce stomal infections. For patients with no neck burn, we support early tracheostomy to reduce the likelihood of dysphagia.

  20. Broad Tissue and Cell Tropism of Avian Bornavirus in Parrots with Proventricular Dilatation Disease▿ †

    PubMed Central

    Rinder, Monika; Ackermann, Andreas; Kempf, Hermann; Kaspers, Bernd; Korbel, Rüdiger; Staeheli, Peter

    2009-01-01

    Avian bornaviruses (ABV), representing a new genus within the family Bornaviridae, were recently discovered in parrots from North America and Israel with proventricular dilatation disease (PDD). We show here that closely related viruses are also present in captive European parrots of various species with PDD. The six ABV strains that we identified in clinically diseased birds are new members of the previously defined ABV genotypes 2 and 4. Viruses of both genotypes readily established persistent, noncytolytic infections in quail and chicken cell lines but did not grow in cultured mammalian cells in which classical Borna disease virus strains replicate very efficiently. ABV antigens were present in both the cytoplasm and nucleus of infected cells, suggesting nuclear replication of ABV. The genome organization of avian and mammalian bornaviruses is highly conserved except that ABV lacks a distinct control element in the 5′ noncoding region of the bicistronic mRNA encoding the viral proteins X and P. Reverse transcription-PCR analysis demonstrated the presence of virus in many, if not all, organs of birds with PDD. Viral nucleic acid was also found in feces of diseased birds, suggesting virus transmission by the fecal-oronasal route. Immunohistochemical analysis of organs from birds with PDD revealed that infection with ABV is not restricted to cells of the nervous system. Thus, ABV exhibits a broad tissue and cell tropism that is strikingly different from classical Borna disease virus. PMID:19297496

  1. Cardiac fibroblasts mediate IL-17A–driven inflammatory dilated cardiomyopathy

    PubMed Central

    Wu, Lei; Ong, SuFey; Talor, Monica V.; Barin, Jobert G.; Baldeviano, G. Christian; Kass, David A.; Bedja, Djahida; Zhang, Hao; Sheikh, Asfandyar; Margolick, Joseph B.; Iwakura, Yoichiro; Rose, Noel R.; Čiháková, Daniela

    2014-01-01

    Inflammatory dilated cardiomyopathy (DCMi) is a major cause of heart failure in individuals below the age of 40. We recently reported that IL-17A is required for the development of DCMi. We show a novel pathway connecting IL-17A, cardiac fibroblasts (CFs), GM-CSF, and heart-infiltrating myeloid cells with the pathogenesis of DCMi. Il17ra−/− mice were protected from DCMi, and this was associated with significantly diminished neutrophil and Ly6Chi monocyte/macrophage (MO/MΦ) cardiac infiltrates. Depletion of Ly6Chi MO/MΦ also protected mice from DCMi. Mechanistically, IL-17A stimulated CFs to produce key chemokines and cytokines that are critical downstream effectors in the recruitment and differentiation of myeloid cells. Moreover, IL-17A directs Ly6Chi MO/MΦ in trans toward a more proinflammatory phenotype via CF-derived GM-CSF. Collectively, this IL-17A–fibroblast–GM-CSF–MO/MΦ axis could provide a novel target for the treatment of DCMi and related inflammatory cardiac diseases. PMID:24935258

  2. Cardiac fibroblasts mediate IL-17A-driven inflammatory dilated cardiomyopathy.

    PubMed

    Wu, Lei; Ong, SuFey; Talor, Monica V; Barin, Jobert G; Baldeviano, G Christian; Kass, David A; Bedja, Djahida; Zhang, Hao; Sheikh, Asfandyar; Margolick, Joseph B; Iwakura, Yoichiro; Rose, Noel R; Ciháková, Daniela

    2014-06-30

    Inflammatory dilated cardiomyopathy (DCMi) is a major cause of heart failure in individuals below the age of 40. We recently reported that IL-17A is required for the development of DCMi. We show a novel pathway connecting IL-17A, cardiac fibroblasts (CFs), GM-CSF, and heart-infiltrating myeloid cells with the pathogenesis of DCMi. Il17ra(-/-) mice were protected from DCMi, and this was associated with significantly diminished neutrophil and Ly6Chi monocyte/macrophage (MO/MΦ) cardiac infiltrates. Depletion of Ly6Chi MO/MΦ also protected mice from DCMi. Mechanistically, IL-17A stimulated CFs to produce key chemokines and cytokines that are critical downstream effectors in the recruitment and differentiation of myeloid cells. Moreover, IL-17A directs Ly6Chi MO/MΦ in trans toward a more proinflammatory phenotype via CF-derived GM-CSF. Collectively, this IL-17A-fibroblast-GM-CSF-MO/MΦ axis could provide a novel target for the treatment of DCMi and related inflammatory cardiac diseases.

  3. Altered protein levels in the isolated extracellular matrix of failing human hearts with dilated cardiomyopathy.

    PubMed

    DeAguero, Joshua L; McKown, Elizabeth N; Zhang, Liwen; Keirsey, Jeremy; Fischer, Edgar G; Samedi, Von G; Canan, Benjamin D; Kilic, Ahmet; Janssen, Paul M L; Delfín, Dawn A

    Dilated cardiomyopathy (DCM) is associated with extensive pathological cardiac remodeling and involves numerous changes in the protein expression profile of the extracellular matrix of the heart. We obtained seven human, end-stage, failing hearts with DCM (DCM-failing) and nine human, nonfailing donor hearts and compared their extracellular matrix protein profiles. We first showed that the DCM-failing hearts had indeed undergone extensive remodeling of the left ventricle myocardium relative to nonfailing hearts. We then isolated the extracellular matrix from a subset of these hearts and performed a proteomic analysis on the isolated matrices. We found that the levels of 26 structural proteins were altered in the DCM-failing isolated cardiac extracellular matrix compared to nonfailing isolated cardiac extracellular matrix. Overall, most of the extracellular matrix proteins showed reduced levels in the DCM-failing hearts, while all of the contractile proteins showed increased levels. There was a mixture of increased and decreased levels of cytoskeletal and nuclear transport proteins. Using immunoprobing, we verified that collagen IV (α2 and α6 isoforms), zyxin, and myomesin protein levels were reduced in the DCM-failing hearts. We expect that these data will add to the understanding of the pathology associated with heart failure with DCM.

  4. Prognostic value of thallium-201 perfusion defects in idiopathic dilated cardiomyopathy

    SciTech Connect

    Doi, Y.L.; Chikamori, T.; Tukata, J.; Yonezawa, Y.; Poloniecki, J.D.; Ozawa, T.; McKenna, W.J. )

    1991-01-15

    To assess the prognostic significance of thallium-201 perfusion defects in patients with idiopathic dilated cardiomyopathy (IDC), 43 patients underwent thallium scintigraphy in addition to clinical, echocardiographic, angiographic and hemodynamic evaluation. Eleven patients had no significant thallium perfusion abnormality, 19 had multiple small defects and 13 had a large defect. During 3.2 +/- 2.2 years, 14 patients had disease-related mortality. The patients who died had a higher incidence of ventricular tachycardia (71 vs 31%; p less than 0.02), increased cardiothoracic ratio (60 +/- 6 vs 54 +/- 6; p = 0.005), decreased fractional shortening (11 +/- 6 vs 15 +/- 5; p less than 0.05), increased pulmonary wedge pressure (15 +/- 7 vs 10 +/- 6 mm Hg; p = 0.05), increased left ventricular end-diastolic pressure (21 +/- 8 vs 14 +/- 6 mm Hg; p = 0.02) and abnormal thallium perfusion defects (13 of 14 vs 16 of 26; p less than 0.05) compared with survivors. Age, gender, left ventricular end-systolic and end-diastolic dimensions, cardiac index and ejection fraction were not statistically different in the survivors versus the patients who died. Kaplan-Meier survival estimates at 1, 3 and 5 years were 100% in patients without significant perfusion abnormality; 89, 77 and 64%, respectively, in patients with multiple small defects; and 84, 76 and 30%, respectively, in patients with a large defect (p less than 0.025 by log rank test).

  5. [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.

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

    PubMed

    Exner, Ulrike; Kaiser, Jasmin; Gier, Susanne

    2013-05-01

    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.

  7. 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

  8. 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.

  9. Effects of hypertrophic and dilated cardiomyopathy mutations on power output by human β-cardiac myosin.

    PubMed

    Spudich, James A; Aksel, Tural; Bartholomew, Sadie R; Nag, Suman; Kawana, Masataka; Yu, Elizabeth Choe; Sarkar, Saswata S; Sung, Jongmin; Sommese, Ruth F; Sutton, Shirley; Cho, Carol; Adhikari, Arjun S; Taylor, Rebecca; Liu, Chao; Trivedi, Darshan; Ruppel, Kathleen M

    2016-01-01

    Hypertrophic cardiomyopathy is the most frequently occurring inherited cardiovascular disease, with a prevalence of more than one in 500 individuals worldwide. Genetically acquired dilated cardiomyopathy is a related disease that is less prevalent. Both are caused by mutations in the genes encoding the fundamental force-generating protein machinery of the cardiac muscle sarcomere, including human β-cardiac myosin, the motor protein that powers ventricular contraction. Despite numerous studies, most performed with non-human or non-cardiac myosin, there is no clear consensus about the mechanism of action of these mutations on the function of human β-cardiac myosin. We are using a recombinantly expressed human β-cardiac myosin motor domain along with conventional and new methodologies to characterize the forces and velocities of the mutant myosins compared with wild type. Our studies are extending beyond myosin interactions with pure actin filaments to include the interaction of myosin with regulated actin filaments containing tropomyosin and troponin, the roles of regulatory light chain phosphorylation on the functions of the system, and the possible roles of myosin binding protein-C and titin, important regulatory components of both cardiac and skeletal muscles.

  10. [Ultrastructural changes of neutrophilic granulocytes in dilated cardiomyopathy and their dynamics after blood irradiation with Helium-Neon laser in vitro].

    PubMed

    Khomeriki, S G; Morozov, I A

    1998-01-01

    Venous blood from 10 patients with dilated cardiomyopathy was irradiated with a laser in vitro. The control group consisted of 20 healthy donors. The neutrophil granulocytes were separated at gradient centrifugation. Alterations of neutrophils manifested with an increase of specific cytoplasmic granules number, thickening of submembrane actin, cell configuration changes with a relative increase of their surface. Laser irradiation of the blood resulted in destruction of the altered (less resistant) cells while morphometric parameters of the remaining cells approaches those of donor cells. Thus, low-intensity laser irradiation results in the renewal of the neutrophil population in patients with dilated cardiomyopathy and normalization of structural-functional changes in the circulating neutrophil population.

  11. Segmental wall motion abnormalities in dilated cardiomyopathy: hemodynamic characteristics and comparison with thallium-201 myocardial scintigraphy

    SciTech Connect

    Yamaguchi, S.; Tsuiki, K.; Hayasaka, M.; Yasui, S.

    1987-05-01

    This study assessed the hemodynamic characteristics of segmental wall motion abnormality of the left ventricle in patients with dilated cardiomyopathy (DCM) and its relation to the thallium-201 (TI-201) myocardial scintigraphy (MPI). Left ventriculograms and MPI in 23 patients were analyzed by the use of quantitative indexes of regional wall motion and TI-201 uptake based on a mean and a standard deviation of 13 normal subjects. Relative normokinesis in our definition was more frequently seen in the inferior wall than in the anterior wall (p less than 0.01). In contrast, severe asynergy was more often seen in the anterior wall than in the inferior wall (p less than 0.01). There were 11 patients who had relative normokinesis and asynergy together. By means of the index of wall motion, the DCM patients were divided into two groups, one with segmental wall motion abnormality (SWMA) and another with diffuse wall motion abnormality (DWMA). The DWMA group had higher left ventricular end-diastolic pressures (p less than 0.05) and the tendency of large left ventricular end-diastolic volumes than the SWMA group. There was a rough correlation (r = 0.58) between the quantitative indexes of TI-201 uptake and wall motion at the same region of the left ventricle. Thus, the nonuniformity of the left ventricular wall motion was recognized in the patients with DCM and more increased preload was shown in the patients with DWMA than in the group with SWMA. Further, the regional asynergy may be related to the localized fibrosis within the left ventricle in DCM, considering the result that the worse TI-201 uptake was roughly accompanied by the more severe asynergy.

  12. Non-linear surface dilatational rheology as a tool for understanding microstructures of air/water interfaces stabilized by oligofructose fatty acid esters.

    PubMed

    van Kempen, Silvia E H J; Schols, Henk A; van der Linden, Erik; Sagis, Leonard M C

    2013-10-28

    In this paper, the rheological response of air/water interfaces, stabilized by various oligofructose fatty acid esters, to oscillatory dilatational deformations was studied and compared to the response of interfaces stabilized by sucrose esters. We have followed a traditional approach to surface rheology, where the development of the modulus as a function of time is studied as well as the frequency dependence of the modulus. We also adopted a different approach where we investigate in detail the amplitude dependence of the modulus. Finally, we studied the temperature dependence. We show that for an accurate characterization of the dilatational rheology of fluid–fluid interfaces with a complex microstructure, a protocol should be used that not only involves variations of surface pressure, frequency, and temperature, but also establishes amplitude dependence. We show that Lissajous plots of surface pressure versus deformation can be useful tools to help interpret surface dilatational behavior in terms of interfacial microstructure. The rheological response of interfaces stabilized by oligofructose esters differed significantly from the response of those stabilized by sucrose esters. Sucrose esters behaved like typical low molecular weight surfactants, and gave interfaces with relatively low moduli, a frequency scaling of the dilatational modulus with an exponent close to 0.5, and displayed no asymmetries in Lissajous plots. In contrast, the oligofructose esters gave, depending on the fatty acid tail, relatively high moduli, almost independent of frequency. Significant asymmetries were observed in the Lissajous plots, with strain hardening during compression and strain softening during extension. Our results suggest that the unusual rheological properties of interfaces stabilized by oligofructose esters may be the result of the formation of a two-dimensional soft glass phase by the oligofructose part of the ester.

  13. 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.

  14. Flexible microsensor technology for real-time navigation tracking in balloon sinus ostial dilation

    PubMed Central

    Lam, Kent; Bigcas, Jo-Lawrence; Luong, Amber; Yao, William

    2017-01-01

    Background: Microsensor navigation has the potential to aid balloon sinus ostial dilation by providing real-time tracking of balloon devices within the complex anatomy of the sinonasal cavities. Objective: This feasibility study evaluated the incorporation of a new microsensor technology into a flexible guidewire for use with current instruments in balloon sinus ostial dilation. Methods: A retrospective study was conducted to include seven men and one woman (age range, 33–68 years), who underwent balloon sinus ostial dilation with flexible microsensor navigation in the operating room setting. All the procedures were performed at target sinuses with the patient under general anesthesia, in conjunction with subsequent endoscopic sinus surgery. Results: Balloon dilation was attempted at the maxillary (n = 3), frontal (n = 14), and sphenoid (n = 1) sinuses. In all the cases, the surgical navigation system displayed the flexible wire tip as it was advanced to the target sinus ostia; this visual feedback for wire position guided the balloon placement. Successful balloon dilation with assistance of flexible microsensor navigation was performed on most sinuses, except a single frontal sinus with adjacent type 2 frontal cells. Conclusion: Flexible navigation technology may be combined with balloon sinus technology to facilitate localization of instruments in the sinus anatomy. Additional optimization of both the device and software technology is warranted. PMID:28381323

  15. Neuromuscular alterations in the dilated ileum of an adult patient with segmental lymphangiectasia.

    PubMed

    Paggi, Silvia; Ferrero, Stefano; Braidotti, Paola; de Rai, Paolo; Conte, Dario; Basilisco, Guido

    2008-09-01

    Intestinal lymphangiectasia is a rare condition, which is characterized by the dilation of small bowel lymphatics and presents with signs and symptoms of protein-losing enteropathy. Some patients have complained of occlusive symptoms attributable to the mechanical obstruction caused by the considerable mucosal edema associated with the lymphatic dilation. On the basis of the hypothesis that alterations in the neuromuscular structures controlling clearance function or gut tone may play a role in ileal dilation, we examined the resected ileum of a 48-year-old male patient with segmental lymphangiectasia histologically, immunohistochemically (for S100 protein, PGP 9.5, Bcl-2, neuron-specific enolase, neurofilaments, synaptophysin, and CD117/C-kit), and by means of electron microscopy. Histology showed pseudocystic dilation of the mucosal, submucosal, and muscular lymphatics with fragmentation of the circular and longitudinal muscle layers. Hardly any neural expression of synaptophysin was observed, but the neural structures were otherwise morphologically normal and reacted normally to the other neural markers. This case shows that neuromuscular alterations can be found in the dilated ileum of patients with segmental lymphangiectasia.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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)

  1. Titin Truncating Variants in Dilated Cardiomyopathy – Prevalence and Genotype-Phenotype Correlations

    PubMed Central

    Franaszczyk, Maria; Chmielewski, Przemyslaw; Truszkowska, Grazyna; Stawinski, Piotr; Michalak, Ewa; Rydzanicz, Malgorzata; Sobieszczanska-Malek, Malgorzata; Pollak, Agnieszka; Szczygieł, Justyna; Kosinska, Joanna; Parulski, Adam; Stoklosa, Tomasz; Tarnowska, Agnieszka; Machnicki, Marcin M.; Foss-Nieradko, Bogna; Szperl, Malgorzata; Sioma, Agnieszka; Kusmierczyk, Mariusz; Grzybowski, Jacek; Zielinski, Tomasz; Ploski, Rafal

    2017-01-01

    TTN gene truncating variants are common in dilated cardiomyopathy (DCM), although data on their clinical significance is still limited. We sought to examine the frequency of truncating variants in TTN in patients with DCM, including familial DCM (FDCM), and to look for genotype-phenotype correlations. Clinical cardiovascular data, family histories and blood samples were collected from 72 DCM probands, mean age of 34 years, 45.8% FDCM. DNA samples were examined by next generation sequencing (NGS) with a focus on the TTN gene. Truncating mutations were followed up by segregation study among family members. We identified 16 TTN truncating variants (TTN trunc) in 17 probands (23.6% of all cases, 30.3% of FDCM, 17.9% of sporadic DCM). During mean 63 months from diagnosis, there was no difference in adverse cardiac events between probands with and without TTN truncating mutations. Among relatives 29 mutation carriers were identified, nine were definitely affected (31%), eight probably affected (27.6%) one possibly affected (3.4%) and eleven were not affected (37.9%). When relatives with all affected statuses were combined, disease penetrance was still incomplete (62.1%) even after exclusion of unaffected relatives under 40 (82%) and was higher in males versus females. In all mutation carriers, during follow-up, 17.4% had major adverse cardiac events, and prognosis was significantly worse in men than in women. In conclusion, TTN truncating variants were observed in nearly one fourth of young DCM patient population, in vast majority without conduction system disease. Incomplete penetrance suggests possible influence of other genetic and/or environmental factors on the course of cardiotitinopathy. Counseling should take into account sex and incomplete penetrance. PMID:28045975

  2. Systolic-diastolic functional coupling in healthy children and in those with dilated cardiomyopathy.

    PubMed

    Friedberg, Mark K; Margossian, Renee; Lu, Minmin; Mercer-Rosa, Laura; Henderson, Heather T; Nutting, Arni; Friedman, Kevin; Molina, Kimberly M; Altmann, Karen; Canter, Charles; Sleeper, Lynn A; Colan, Steven D

    2016-06-01

    Systolic and diastolic function affect dilated cardiomyopathy (DCM) outcomes. However, systolic-diastolic coupling, as a distinct characteristic, may itself affect function but is poorly characterized. We hypothesized that echocardiographic left ventricular (LV) longitudinal systolic tissue velocities (S') correlate with diastolic longitudinal velocities (E') and that their relationship is associated with ventricular function and that this relationship is impaired in pediatric DCM. We analyzed data from the Pediatric Heart Network Ventricular Volume Variability study, using linear regression and generalized additive modeling to assess relationships between S' and E' at the lateral and septal mitral annulus. We explored relationships between the systolic:diastolic (S:D) coupling ratio (S':E' relative to age) and ventricular function. Up to 4 echocardiograms from 130 DCM patients (mean age: 9.3 ± 6.1 yr) and 1 echocardiogram from each of 591 healthy controls were analyzed. S' and E' were linearly related in controls (r = 0.64, P < 0.001) and DCM (r = 0.83, P < 0.001). In DCM, the magnitude of association between S' and E' was reduced with progressive ventricular remodeling. The S:D ratio was more strongly associated with LV function in controls vs. DCM. The septal S:D ratio was higher (presumed worse) in DCM vs. controls (0.69 ± 0.13 vs. 0.62 ± 0.12, P = 0.001). A higher septal S:D ratio was associated with worse LV dimensions (parameter estimate: 0.0061, P = 0.004), mass (parameter estimate: 0.0074, P = 0.002), ejection fraction (parameter estimate: -0.0303, P = 0.024), and inflow propagation (parameter estimate: -0.3538, P < .001). S:D coupling becomes weaker in DCM with LV remodeling and dysfunction. The S:D coupling ratio may be useful to assess coupling, warranting study in relation to patient outcomes.

  3. [Anesthetic management of a child with dilated cardiomyopathy associated with congenital fiber-type disproportion].

    PubMed

    Kawaraguchi, Yoshitaka; Taniguchi, Akihiro; Fukumitsu, Kazuo; Kinouchi, Keiko; Miyamoto, Yoshikazu; Hirao, Osamu; Kitamura, Seiji

    2002-04-01

    A 3-year-old girl, who presented with dilated cardiomyopathy in conjunction with congenital fiber-type disproportion, underwent open reduction for congenital dislocation of the hip. Preoperative echocardiography de