2,184 research outputs found
Oral and pharyngeal cancer in South Asians and non-South Asians in relation to socioeconomic deprivation in South East England.
No full textFrom UK Thames Cancer Registry data, after controlling for socioeconomic deprivation of area of residence, South Asian males showed a higher relative risk of oral (1.36; 95% CI: 1.11, 1.67), but not of pharyngeal cancer than non-South Asian males, whereas South Asian females had much higher risks of these cancers (3.67; 95% CI: 2.97, 4.53 and 2.06; 95% CI: 1.44, 2.93), respectively, than non-South Asians
Constraint Handling in RV-GOMEA
No full textThe Real-Valued Gene-pool Optimal Mixing Evolutionary Algorithm (RV-GOMEA) is a state-of-the-art algorithm for single-objective, real-valued optimization. As many practical applications are inherently constrained, evolutionary algorithms are equipped with constraint handling techniques to allow optimizing constrained problems. The approach currently in use with RV-GOMEA prioritizes solution feasibility over the objective value in all cases, pressuring the algorithm to find feasible solutions. However, this can be inefficient if the constrained optimum is located at the constraint boundary, as search is discouraged from exploring the search space close to infeasible solutions.In this thesis, several well-known constraint handling techniques from literature are adapted for use with RV-GOMEA and evaluated on different benchmark problems, identifying the strengths and limitations of the various techniques. Furthermore, the inefficiency of the current technique is investigated in detail. Based on the insights gained, modifications to the existing techniques are proposed, leading to promising preliminary results.Computer Science | Artificial Intelligenc
Using all-cause mortality to define severe RV dilation with RV/LV volume ratio
No full textAbstractRight ventricular (RV) end-diastolic volume (EDV) to left ventricular (LV) EDV ratio using cardiovascular magnetic resonance imaging (CMR) is an important parameter for RV size evaluation in additional to indexed EDV. We explore the severity partition for RV dilation using mortality in a population of 62 patients with pulmonary hypertension (PH). Cine short-axis images were acquired with a 1.5 T MR scanner using a steady-state free precession sequence. The optimal cutoff to classify severe RV dilation was determined by a receiver-operating curve (ROC) analysis based on mortality. We further defined mild and moderate categories by the standard deviation distance between normal and severely dilated and found the categories RV dilation by RV/LV volume ratio to be “mild” (1.27–1.69), “moderate” (1.70–2.29) and “severe” (≥2.30). There were significant differences in RVEDV and RV ejection fraction between “mild”, “moderate” and “severe” groups (p < 0.001). The “severe” category had a significantly higher mortality when compared to the “non-severe” categories (p < 0.001) while there was no difference among the “non-severe” dilated groups. We have shown that severe RV dilation partition can be defined using mortality with RV/LV volume ratio, which offers an outcome based grading of the “severe” category of RV dilation.</jats:p
Serial RV wall stress measurements:association with right ventricular function in repaired Tetralogy of Fallot patients
No full textBackground: Optimal timing of pulmonary valve replacement (PVR) in Tetralogy of Fallot (TOF) patients remains challenging. Ventricular wall stress is considered to be an early marker of right ventricular (RV) dysfunction.Objectives: To investigate the association of RV wall stresses and their change over time with functional parameters in TOF patients.Methods: Ten TOF patients after surgical repair with moderate/severe pulmonary regurgitation were included. At two timepoints (median follow-up time 7.2 years), patient-specific computational biventricular models for wall stress assessment were created using CMR short-axis cine images and echocardiography-based RV pressures. RV ejection fraction (RVEF), NT-proBNP and cardiopulmonary exercise tests were used as outcome measures reflecting RV function. Associations between regional RV diastolic wall stress and RV function were investigated using linear mixed models.Results: Increased wall stress correlated with lower RV mass (rrm = −0.70, p = 0.017) and lower RV mass-to-volume (rrm = −0.80, p = 0.003) using repeated measures. Wall stress decreased significantly over time, especially in patients with a stable RVEF (p < 0.001). Higher wall stress was independently associated with lower RVEF, adjusted for left ventricular ejection fraction, RV end-diastolic volume and time since initial surgery (decrease of 1.27% RVEF per kPa increase in wall stress, p = 0.029) using repeated measurements. No association was found between wall stress, NT-proBNP, and exercise capacity.Conclusions: Using a computational method to calculate wall stress locally in geometrically complex ventricles, we demonstrated that lower wall stress might be important to maintain ventricular function. RV wall stress assessment can be used in serial follow-up, and is potentially an early marker of impending RV dysfunction
Usefulness of tricuspid annular velocity in identifying global RV dysfunction in patients with primary pulmonary hypertension: A comparison with 3D echo-derived right ventricular ejection fraction
No full textWhile right ventricular (RV) function and size are important clinical markers in several cardiac conditions, the assessment of RV function by two-dimensional (2D) echocardiography remains challenging, due to the complexity of RV geometry. We therefore sought to compare an easily-measured parameter, peak systolic velocity of tricuspid annulus (TAPSV) obtained by tissue Doppler imaging (TDI), to right ventricular ejection fraction (RVEF) measured by real time three-dimensional echocardiography (RT3DE) and to explore what TAPSV cutoff values would be useful in detecting global RV dysfunction. We enrolled 20 patients affected by primary pulmonary hypertension and 30 consecutive healthy volunteers, who underwent transthoracic echocardiography, RT3DE and tissue Doppler evaluation. TAPSV had a statistically significant correlation with RVEF (r = 0.66, P < 0.001). With RV dysfunction defined as RVEF < 40%, a TAPSV cutoff value of 9.5 cm/sec yielded the best compromise between sensitivity, specificity, and positive predictive value and negative predictive value. In conclusion, a TAPSV cutoff value of 9.5 cm/sec yields significantly high sensitivity and specificity and appears to be a valid compromise in detecting RV dysfunction, TAPSV values however are not useful in evaluating the severity of RV dysfunction
Predicted age-specific efficacy on severe RV-GE and all RV-GE.
No full text<p>A) Vaccine efficacy: Severe RV-GE. B) Vaccine efficacy: All RV-GE.</p
Environmental and Parental Influences on Offspring Health and Growth in Great Tits (Parus major)
No full textPMCID: PMC3728352This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
The RV from HLHS exhibits depleted cellular content.
No full texta, Bright-field images of spontaneously generated C-spheres obtained from HLHS patient (7 month of age) and patient with dilated cardiomyopathy (DCM) (6 months of age). Scale bar, 200 μm. b, Bright-field images of C-spheres obtained from both DCM-RV and DCM-LV heart samples propagated in multiple passages. Scale bar, 400 μm. c, Representative fluorescence microscopy images of C-spheres derived from the LV and the RV of HLHS patient immunostained for vimentin (in green) and c-kit (in red). Scale bar 100 μm. d, Representative fluorescence microscopy images of C-sphere-derived cells (CDCs) obtained from the RV and the LV of end-stage HLHS immunostained for various differentiation markers, including stem cell antigen c-kit, fibronectin, fibroblast marker Fsp-1, early cardiogenic marker (β-myosin heavy chain, MF-20) and mesenchymal cell marker vimentin. Scale bar, 100 μm. Nuclei were marked with DAPI staining (in blue). e, Percentage of c-kit and vimentin positive cells in CDCs isolated from HLHS-LV versus CDCs isolated from HLHS-RV. Bar graphs represent mean values ± SEM, n = 10 random fields. c-kit, ** P value P value<0.0001.</p
Prognostic Value of RV Abnormalities on CMR in Patients With Known or Suspected Cardiac Sarcoidosis
No full textBackground Left ventricular abnormalities in cardiac sarcoidosis (CS) are associated with adverse cardiovascular events, whereas the prognostic value of right ventricular (RV) involvement found on cardiac magnetic resonance is unclear. Objectives This study aimed to systematically assess the prognostic value of right ventricular ejection fraction (RVEF) and RV late gadolinium enhancement (LGE) in known or suspected CS. Methods This study was prospectively registered in PROSPERO (CRD42022302579). PubMed, Embase, and Web of Science were searched to identify studies that evaluated the association between RVEF or RV LGE on clinical outcomes in CS. A composite endpoint of all-cause death, cardiovascular events, or sudden cardiac death (SCD) was used. A meta-analysis was performed to determine the pooled risk ratio (RR) for these adverse events. The calculated sensitivity, specificity, and area under the curve with 95% CIs were weighted and summarized. Results Eight studies including a total of 899 patients with a mean follow-up duration of 3.2 ± 0.7 years were included. The pooled RR of RV systolic dysfunction was 3.1 (95% CI: 1.7-5.5; P < 0.01) for composite events and 3.0 (95% CI: 1.3-7.0; P < 0.01) for SCD events. In addition, CS patients with RV LGE had a significant risk for composite events (RR: 4.8 [95% CI: 2.4-9.6]; P < 0.01) and a higher risk for SCD (RR: 9.5 [95% CI: 4.4-20.5]; P < 0.01) than patients without RV LGE. Furthermore, the pooled area under the curve, sensitivity, and specificity of RV LGE for identifying patients with CS who were at highest SCD risk were 0.8 (95% CI: 0.8-0.9), 69% (95% CI: 50%-84%), and 90% (95% CI: 70%-97%), respectively. Conclusions In patients with known or suspected CS, RVEF and RV LGE were both associated with adverse events. Furthermore, RVLGE shows good discrimination in identifying CS patients at high risk of SCD
Schematic representation of differentiation capacity in LV and RV in HLHS.
No full texta, C-spheres generated from LV in HLHS are comprised of continuously layered double-positive c-kit+ and vimentin+ cells. C-spheres generate cardiosphere-derived cells which possess adherence properties consistent with a cardiac mesenchymal cell (CMC), and exhibit differentiation capacity into multiple cardiovascular lineage cell types as shown. Immature cardiomyocytes are more frequent in the LV than the RV. b, Excessive RV mechanical stress results in depletion of regenerative capacity in the RV in HLHS. CMCs within HLHS-RV tissue are sparsely distributed on the surface of the tissue fragments and create a non-spherical shape. These cells are vimentin-positive and c-kit-negative and become incompetent for differentiation as a result of stress-induced senescence. CMCs, cardiac mesenchymal cells; EC, endothelial cells; CM, cardiomyocyte; FB, fibroblast; SMC, smooth muscle cell.</p
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