Search results for "Left"

A multiscale X-ray phase-contrast tomography dataset of whole human left lung

2021

ABSTRACTTechnological advancements in X-ray imaging using bright and coherent synchrotron sources now allows to decouple sample size and resolution, while maintaining high sensitivity to the microstructure of soft, partially dehydrated tissues. The recently developed imaging technique, hierarchical phase-contrast tomography, is a comprehensive approach to address the challenge of organ-scale (up to tens of centimeters) soft tissue imaging with resolution and sensitivity down to the cellular level. Using this technique, we imaged ex vivo an entire human left lung at an isotropic voxel size of 25.08 μm along with local zooms down to 6.05 - 6.5 μm and 2.45 - 2.5 μm in voxel size. The high tiss…

A giant left atrium in a patient with Barlow syndrome, abnormal chordae tendineae, and perforation of the anterior mitral leaflet

2019

Isolation of the left atrial surface from cardiac multi-detector CT images based on marker controlled watershed segmentation

2006

The delineation of left atrium (LA) and pulmonary veins (PVs) anatomy from high resolution images holds importance for atrial fibrillation (AF) investigation and treatment. In this study, a semiautomatic segmentation procedure for LA and PVs inner surface from contrast enhanced CT data was developed. The procedure consists of a three dimensional marker controlled watershed segmentation applied to the external morphological gradient, followed by variable threshold surface extraction from the original intensity image. A preliminary anisotropic non-linear filtering was implemented to improve the S/N ratio of CT images. The performance of segmentation was evaluated on cardiac CT scans of 12 AF …

Quantitative study of cardiac wall motion from cine-MRI using frequency-based optical flow methods

2010

The aim of this thesis is to study parietal desynchronisation of the left ventricle from conventional cine-MRI. The first part of our work consisted in the quantification of the left ventricle wall motion of the heart directly from conventional retrospective SSFP type cine-MRI sequences used in the study of cardiac function. The developed methods for measuring displacements within the images are frequency-based optical flow methods. These techniques seem to be particularly adapted to MRI specificities. We have demonstrated their robustness in the event of Rician noise and pixel intensity variations as a function of time. These variations are often associated with the through-plane motion of…

2015

The execution of unilateral hand contractions before performance has been reported to produce behavioral aftereffects in various tasks. These effects have been regularly attributed to an induced shift in activation asymmetry to the contralateral hemisphere produced by the contractions. An alternative explanation proposes a generalized state of reduced bilateral cortical activity following unilateral hand contractions. The current experiment contrasted the above explanation models and tested the state of cortical activity after the termination of unilateral hand contractions. Twenty right-handed participants performed hand contractions in two blocks, one for each hand. Using electroencephalo…

Testis asymmetry in birds: the influences of sexual and natural selection

2014

Gonad size and shape asymmetries are particularly common in birds. Although some obvious size and shape differences between the left and right testes in birds were first documented more than a century ago, little is known about what influences the variation across species in either the degree or the direction of these asymmetries. Here we show that a left bias in size is the most likely ancestral state in most orders and families, and that there is a weak but significant negative relation between the degree of size and shape asymmetries. In extant species, testis size and shape symmetries increase with the degree of sperm competition (relative testes mass), but those relations are significa…

Association between biomarkers of inflammation and left ventricular hypertrophy in moderate chronic kidney disease.

2007

Aims: Left ventricular hyper- trophy (LVH) is a predictor for cardiovascu- lar mortality, and it is considered to be a surro- gate marker of preclinical cardiovascular dis- ease. This study aimed at evaluating whether fetuin-A plasma levels are decreased in pa- tients with moderate chronic kidney disease (CKD) and their linkage to plasma concentra- tions of hs-C-reactive protein (CRP), cardio- trophyn-1 (CT-1), tumor necrosis factor- (TNF-), propeptide of collagen Type I (PIP) and to LVH. Material and methods: We enrolled 64 moderate CKD and 55 essential hypertensives (EH) with normal renal func- tion as controls. All the patients underwent an echocardiographic examination; plasma sam- ples…

Evidence for bilateral vagal innervation of postganglionic parasympathetic neurons in chicken heart

1983

Stimulation of the cervical vagus nerves caused an output of acetylcholine (ACh) from the isolated chicken heart, which almost exclusively was released from the postganglionic neurons: (+)-tubocurarine (3 X 10(-14) M) reduced the output to 12 +/- 6% (n = 7) of the control. Stimulation of the two nerve trunks ws equally effective in releasing ACh.--Evidence that a large number of postganglionic neurons receives bilateral innervation was based on two experimental series. (1). The sum of the ACh outputs evoked by unilateral (separate) nerve stimulation of the right and the left vagus was higher than the bilaterally evoked output (100%) and increased with increasing frequencies (10, 20 and 40 H…

Identification of susceptibility genes in non-syndromic cleft lip with or without cleft palate using whole-exome sequencing

2015

Background Non-syndromic cleft lip with or without cleft palate (NSCL/P) is among the most common congenital malformations. The etiology of NSCL/P remains poorly characterized owing to its complex genetic heterogeneity. The objective of this study was to identify genetic variants that increase susceptibility to NSCL/P. Material and Methods Whole-exome sequencing (WES) was performed in 8 fetuses with NSCL/P in China. Bioinformatics analysis was performed using commercially available software. Variants detected by WES were validated by Sanger sequencing. Results By filtering out synonymous variants in exons, we identified average 8575 nonsynonymous single nucleotide variants (SNVs). We subseq…

Diuretic Therapy in Old Patients

1984

The administration of diuretics is indicated in several clinical conditions characterized by more or less severe water and salt retention (congestive heart failure, non-compensated liver cirrhosis, renal syndromes etc.), or in cases in which water and sodium depletion is supposed to improve some pathophysiological aspects of clinical symptoms (e. g. as background treatment in arterial hypertension, or as emergency treatment in left ventricular failure.