Ventricular pressures in phonating excised larynges.
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ABSTRACT:
SUBMITTER: Alipour F
PROVIDER: S-EPMC3427366 | biostudies-other | 2012 Aug
REPOSITORIES: biostudies-other
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Project description:Purpose The excised canine larynx provides an advantageous experimental framework in the study of voice physiology. In recent years, signal processing methods have been applied to analyze phonations in excised canine larynx experiments. However, phonations have a highly complex and nonstationary nature corresponding to different proportions of regular and chaotic signal elements. Current nonlinear dynamic methods that are used to assess the degree of irregularity in the voice fail to recognize the distribution of voice type components (VTCs). Method Based on measures of intrinsic dimension, this article presents a method to analyze the VTC distribution of phonations in excised canine larynx experiments. Thirty-nine phonation samples from 13 excised canine larynges at three different subglottal pressures were analyzed. Results Phonation produced with subglottal pressures above phonation instability pressure (PIP) and below phonation threshold pressure (PTP) resulted in high proportions of Voice Types 3 and 4, characterized by chaotic and noisy signals. Phonation produced with pressure between PTP and PIP contained mostly Type 1 voice, characterized by a regular and nearly periodic signal. Mean proportions of all VTCs varied significantly in comparisons of phonations produced with Sub-PTP and PTP as well as in comparisons of phonations produced with PTP and PIP. Conclusions Across all VTCs, the VTC profiles of normal and abnormal phonation differ significantly. Normal phonation is strongly associated with VTC1 (Voice Type Component 1), whereas abnormal phonation exhibits increased VTC4 (Voice Type Component 4). The study further demonstrates the ability of intrinsic dimension to successfully detect multiple voice types in an acoustic signal and highlights the need for expanded use of intrinsic dimension in human voice. Supplemental Material https://doi.org/10.23641/asha.14417585.
| S-EPMC8608150 | biostudies-literature
Project description:Understanding the viability of the ischemic myocardial tissue is a critical issue in determining the appropriate surgical procedure for patients with chronic heart failure after myocardial infarction (MI). Conventional MI evaluation methods are; however, preoperatively performed and/or give an indirect information of myocardial viability such as shape, color, and blood flow. In this study, we realize the evaluation of MI in patients undergoing cardiac surgery by Raman spectroscopy under label-free conditions, which is based on intrinsic molecular constituents related to myocardial viability. We identify key signatures of Raman spectra for the evaluation of myocardial viability by evaluating the infarct border zone myocardium that were excised from five patients under surgical ventricular restoration. We also obtain a prediction model to differentiate the infarcted myocardium from the non-infarcted myocardium by applying partial least squares regression-discriminant analysis (PLS-DA) to the Raman spectra. Our prediction model enables identification of the infarcted tissues and the non-infarcted tissues with sensitivities of 99.98% and 99.92%, respectively. Furthermore, the prediction model of the Raman images of the infarct border zone enabled us to visualize boundaries between these distinct regions. Our novel application of Raman spectroscopy to the human heart would be a useful means for the detection of myocardial viability during surgery.
| S-EPMC6168494 | biostudies-literature
Project description:Echocardiographic assessment of diastolic dysfunction depends on surrogate parameters. In recent years, guideline committees attempted to combine these parameters to diagnostic flowcharts allowing for correct classification of left ventricular filling pressures (LVFP). The value of these diagnostic tools is limited if the applied surrogate parameters are elevated due to other reasons as is the case with maximal tricuspid regurgitation velocity. We aimed to compare the accuracy of the 2009 and the 2016 guideline recommendations in patients with pulmonary hypertension (PH). We included 101 consecutive patients who underwent right heart catheterization and transthoracic echocardiography for suspicion of PH. For the final analysis, only patients with PH were considered. The 2009 and 2016 recommendations for the assessment of diastolic function by echocardiography were applied on each patient. A total of 63 PH patients were included in the final analysis, 43% had elevated LVFP. By using the 2009 recommendations, sensitivity for correct classification of diastolic dysfunction was 67%, specificity was 82%, area under the curve (AUC) was 0.74. By using the 2016 recommendations, sensitivity for correct classification of diastolic dysfunction was 84%, specificity was 80%, AUC was 0.82. In ROC comparison, the AUC for the 2016 recommendations with 0.82 was significantly better compared to the AUC of 0.74 for the 2009 recommendations (p = 0.04). Our study demonstrates that the 2016 recommendations for echocardiographic evaluation of diastolic function are superior to the 2009 recommendations in estimating left ventricular filling pressures in patients with PH.
| S-EPMC6486531 | biostudies-literature
Project description:AimThe aim of this study was to assess PCWP with passive leg-lifting (PLL) and exercise, in two groups of patients presenting with normal left ventricular ejection fraction (LVEF); one group with elevated NT-proBNP (eBNP), and one with normal NT-proBNP (nBNP) plasma concentration.Methods and resultsFifty-one patients with eBNP (NT-proBNP ≥ 125 ng/l) and LVEF > 50%, were investigated and compared with 34 patients with nBNP (NT-proBNP < 125 ng/l) and LVEF > 50%. Both groups underwent right heart catheterization (RHC) at rest, PLL and exercise. From RHC, mean pulmonary arterial pressure (mPAP), cardiac output (CO), and PCWP were measured. All nBNP patients had PCWP < 15 mmHg at rest, and a PCWP of < 25 mmHg with PLL and during exercise. Patients with eBNP had higher (p < 0.01) resting mPAP, PCWP, and mPAP/CO. These values increased with exercise; however, CO increased less in comparison with nBNP patients (p = 0.001). 20% of patients with eBNP had a PCWP > 15 mmHg at rest, this percentage increased to 47% with PLL and 41% had a PCWP > 25 mmHg during exercise. Of those with PCWP > 25 mmHg during exercise, 91% had a PCWP > 15 mmHg with PLL. A PCWP > 15 mmHg on PLL had a 91% sensitivity and 92% specificity in predicting exercise-induced PCWP of > 25 mmHg.ConclusionIn patients presenting with eBNP, PLL can predict which patients will develop elevated PCWP with exercise. These findings highlight the role of stress assessment.
| S-EPMC7098926 | biostudies-literature
Project description:AimsWe reported that patients with small aortic valve area (AVA) and low flow despite preserved left ventricular ejection fraction (LVEF), i.e. 'paradoxical' low flow (PLF), have worse outcomes compared with patients with normal flow (NF), although they generally have a lower mean gradient (MG). The aortic valve weight (AVW) excised at the time of valve replacement is a flow-independent marker of stenosis severity. The objective of this study was to compare the AVW of patients with PLF and MG<40 mmHg with the AVW of patients with NF and MG≥40 mmHg.Methods and resultsWe recruited 250 consecutive patients undergoing valve replacement (Cohort A) for severe stenosis. Among them, 33 (13%) were in PLF [LVEF > 50% but stroke volume index (SVi) ≤ 35 mL/m(2)] with MG < 40 mmHg (PLF-LG group) and 105 (42%) were in NF (LVEF > 50% and SVi > 35 mL/m(2)) with MG ≥ 40 mmHg (NF-HG group). Despite a much lower MG (29 ± 7 vs. 53 ± 10 mmHg; P < 0.0001), patients in the PLF-LG group had a similar AVA (0.73 ± 0.12 vs. 0.69 ± 0.13; P = 0.19) compared with those in the NF-HG group. The AVW [median (interquartile): 1.90 (1.63-2.50) vs. 2.60 (1.66-3.32)] and prevalence of bicuspid phenotype (15 vs. 42%) were lower in the PLF-LG group than in the NF-HG group. However, AVWs analysed separately in the tricuspid and bicuspid valves were similar in both groups [tricuspid valves: 1.80 (1.63-2.50) vs. 2.30 (1.58-3.00) g; P = 0.26 and bicuspid valves: 2.72 (1.73-3.61) vs. 2.60 (2.10-3.55) g; P = 0.93]. When using cut-point values of AVW established in another series of non-consecutive patients (n = 150, Cohort B) with NF and concordant Doppler-echocardiographic findings, we found that the percentage of patients with evidence of severe stenosis in Cohort A was 70% in patients with PLF-LG and 86% in patients with NF-HG.ConclusionThe aortic valve weight data reported in this study provide evidence that a large proportion of patients with PLF and low-gradient have a severe stenosis and that the gradient may substantially underestimate stenosis severity in these patients. A multi-parametric approach including all Doppler-echocardiographic parameters of valve function as well as other complementary diagnostic tests may help correctly identify these patients.
| S-EPMC4187204 | biostudies-literature
Project description:Spliceosomal introns are ubiquitous non-coding RNAs typically destined for rapid debranching and degradation. Here, we describe 34 excised Saccharomyces cerevisiae introns that, although rapidly degraded in log-phase growth, accumulate as linear RNAs under either saturated-growth conditions or other stresses that cause prolonged inhibition of TORC1, a key integrator of growth signaling. Introns that become stabilized remain associated with components of the spliceosome and differ from other spliceosomal introns in having a short distance between their lariat branch point and 3´ splice site, which is necessary and sufficient for their stabilization. Deletion of these unusual introns is disadvantageous in saturated conditions and causes aberrantly high growth rates of yeast chronically challenged with the TORC1 inhibitor rapamycin. Reintroduction of native or engineered stable introns suppresses this aberrant rapamycin response. Thus, excised introns function within the TOR growth-signaling network of S. cerevisiae, and more generally, excised spliceosomal introns can have biological functions.
2018-10-29 | GSE121765 | GEO
Project description:Pulmonary involvement in Coronavirus disease 2019 (COVID-19) may affect right ventricular (RV) function and pulmonary pressures. The prognostic value of tricuspid annular plane systolic excursion (TAPSE), systolic pulmonary artery pressure (PAPS), and TAPSE/PAPS ratios have been poorly investigated in this clinical setting. This is a multicenter Italian study, including consecutive patients hospitalized for COVID-19. In-hospital mortality and pulmonary embolism (PE) were identified as the primary and secondary outcome measures, respectively. The study included 227 (16.1%) subjects (mean age 68 ± 13 years); intensive care unit (ICU) admission was reported in 32.2%. At competing risk analysis, after stratifying the population into tertiles, according to TAPSE, PAPS, and TAPSE/PAPS ratio values, patients in the lower TAPSE and TAPSE/PAPS tertiles, as well as those in the higher PAPS tertiles, showed a significantly higher incidence of death vs. the probability to be discharged during the hospitalization. At univariable logistic regression analysis, TAPSE, PAPS, and TAPSE/PAPS were significantly associated with a higher risk of death and PE, both in patients who were and were not admitted to ICU. At adjusted multivariable regression analysis, TAPSE, PAPS, and TAPSE/PAPS resulted in independently associated risk of in-hospital death (TAPSE: OR 0.85, CI 0.74-0.97; PAPS: OR 1.08, CI 1.03-1.13; TAPSE/PAPS: OR 0.02, CI 0.02 × 10-1-0.2) and PE (TAPSE: OR 0.7, CI 0.6-0.82; PAPS: OR 1.1, CI 1.05-1.14; TAPSE/PAPS: OR 0.02 × 10-1, CI 0.01 × 10-2-0.04). Echocardiographic evidence of RV systolic dysfunction, increased PAPS, and poor RV-arterial coupling may help to identify COVID-19 patients at higher risk of mortality and PE during hospitalization.
| S-EPMC8705674 | biostudies-literature
Project description:Echocardiographic assessment of left ventricular (LV) filling pressures is performed using a multi-parametric algorithm. Left atrial (LA) strain was recently found to accurately classify the degree of diastolic dysfunction. We hypothesized that LA strain could be used as a stand-alone marker and sought to identify and test a cutoff, which would accurately detect elevated LV pressures. We studied 76 patients with a spectrum of LV function who underwent same-day echocardiogram and invasive left-heart catheterization. Speckle tracking was used to measure peak LA strain. The protocol involved a retrospective derivation group (N = 26) and an independent prospective validation cohort (N = 50) to derive and then test a peak LA strain cutoff which would identify pre-A-wave LV diastolic pressure > 15 mmHg. The guidelines-based assessment of filling pressures and peak LA strain were compared side-by-side against invasive hemodynamic data. In the derivation cohort, receiver-operating characteristic analysis showed area under curve of 0.76 and a peak LA strain cutoff < 20% was identified as optimal to detect elevated filling pressure. In the validation cohort, peak LA strain demonstrated better agreement with the invasive reference (81%) than the guidelines algorithm (72%). The improvement in classification using LA strain compared to the guidelines was more pronounced in subjects with normal LV function (91% versus 81%). In summary, the use of a peak LA strain to estimate elevated LV filling pressures is more accurate than the current guidelines. Incorporation of LA strain into the non-invasive assessment of LV diastolic function may improve the detection of elevated filling pressures.
| S-EPMC6353699 | biostudies-literature
Project description:BackgroundIn ≈25% of patients with heart failure and reduced left-ventricular ejection fraction, right-ventricular (RV), and left-ventricular (LV) filling pressures are discordant (ie, one is elevated while the other is not). Whether clinical assessment allows detection of this discordance is unknown. We sought to determine the agreement of clinically versus invasively determined patterns of ventricular congestion.MethodsIn 156 heart failure and reduced LV ejection fraction subjects undergoing invasive hemodynamic assessment, we categorized patterns of ventricular congestion (no congestion, RV only, LV only, or both) based on clinical findings of RV (jugular venous distention) or LV (hepatojugular reflux, orthopnea, or bendopnea) congestion. Agreement between clinically and invasively determined (RV congestion if right atrial pressure [RAP] ≥10 mm Hg and LV congestion if pulmonary capillary wedge pressure [PCWP] ≥22 mm Hg) categorizations was the primary end point.ResultsThe frequency of clinical patterns of congestion was: 51% no congestion, 24% both RV and LV, 21% LV only, and 4% RV only. Jugular venous distention had excellent discrimination for elevated RAP (C=0.88). However, agreement between clinical and invasive congestion patterns was poor, к=0.44 (95% CI, 0.34-0.55). While those with no clinical congestion usually had low RAP and PCWP (67/79, 85%), over one-half (24/38, 64%) with isolated LV clinical congestion had PCWP <22 mm Hg, most (5/7, 71%) with isolated RV clinical congestion had PCWP ≥22 mm Hg, and ≈one-third (10/32, 31%) with both RV and LV clinical congestion had elevated RAP but PCWP <22 mm Hg.ConclusionsWhile clinical examination allows accurate detection of elevated RAP, it does not allow accurate detection of discordant RV and LV filling pressures.
| S-EPMC8595783 | biostudies-literature
Project description:Spliceosomal introns are ubiquitous non-coding RNAs that are typically destined for rapid debranching and degradation. Here we describe 34 excised introns in Saccharomyces cerevisiae that-despite being rapidly degraded in log-phase growth-accumulate as linear RNAs under either saturated-growth conditions or other stresses that cause prolonged inhibition of TORC1, which is a key integrator of growth signalling. Introns that become stabilized remain associated with components of the spliceosome and differ from other spliceosomal introns in having a short distance between their lariat branch point and 3' splice site, which is necessary and sufficient for their stabilization. Deletion of these unusual introns is disadvantageous in saturated conditions and causes aberrantly high growth rates in yeast that are chronically challenged with the TORC1 inhibitor rapamycin. The reintroduction of native or engineered stable introns suppresses this aberrant rapamycin response. Thus, excised introns function within the TOR growth-signalling network of S. cerevisiae and, more generally, excised spliceosomal introns can have biological functions.
| S-EPMC6464110 | biostudies-literature