scholarly journals Left-right asymmetry in heart development and disease: forming the right loop

Development ◽  
2018 ◽  
Vol 145 (22) ◽  
pp. dev162776 ◽  
Author(s):  
Audrey Desgrange ◽  
Jean-François Le Garrec ◽  
Sigolène M. Meilhac
Keyword(s):  
Heart Development ◽  
Right Loop ◽  
Left Right Asymmetry ◽  
The Right

Brain asymmetry, immunity, handedness

Open Medicine ◽  
2012 ◽  
Vol 7 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Zlatislav Stoyanov ◽  
Lyoubka Decheva ◽  
Irina Pashalieva ◽  
Piareta Nikolova
Keyword(s):  
Immune Response ◽  
Human Brain ◽  
Right Hemisphere ◽  
Functional Organization ◽  
Brain Asymmetry ◽  
Internal Environment ◽  
Living Nature ◽  
Left Right Asymmetry ◽  
The Right

AbstractThe principle of symmetry-asymmetry is widely presented in the structural and functional organization of the nonliving and living nature. One of the most complex manifestations of this principle is the left-right asymmetry of the human brain. The present review summarizes previous and contemporary literary data regarding the role of brain asymmetry in neuroimmunomodulation. Some handedness-related peculiarities are outlined additionally. Brain asymmetry is considered to be imprinted in the formation and regulation of the individual’s responses and relationships at an immunological level with the external and internal environment. The assumptions that the hemispheres modulate immune response in an asymmetric manner have been confirmed in experiments on animals. Some authors assume that the right hemisphere plays an indirect role in neuroimmunomodulation, controlling and suppressing the left hemispheric inductive signals.

Double aortic arch presenting with a foreign object in the oesophagus: a case report and imaging diagnosis

2017 ◽  
Vol 27 (8) ◽  
pp. 1651-1653
Author(s):  
Xiuzhen Yang ◽  
Jingjing Ye ◽  
Zhan Gao
Keyword(s):  
Aortic Arch ◽  
Ct Angiography ◽  
Subclavian Artery ◽  
Three Dimensional ◽  
Double Aortic Arch ◽  
Foreign Object ◽  
Right Loop ◽  
Dimensional Reconstruction ◽  
History Of ◽  
The Right

AbstractIn this article, we report a rare case of double aortic arch. The case presented initially with a foreign object in the oesophagus. The patient was a 2-year-old boy, who was referred with primary symptoms of tussis (15 days) and emesis (2 days). He had a history of ingesting a coin. Routine chest X-ray indicated a rounded, metal foreign object in the upper oesophagus. A half-Yuan coin was removed by gastroduodenoscopy. Echocardiographic imaging suggested that the patient had double aortic arch, which was subsequently diagnosed by CT angiography with three-dimensional reconstruction. The right subclavian artery arose from the right loop of the double aortic arch. The left subclavian artery as well as left and right common carotid arteries had distinct origins from the left aortic arch. Imaging also indicated atresia of the distal left arch. The patient underwent corrective surgery and made a full recovery. Despite the rarity, double aortic arch should be considered when patients present with a foreign object in the oesophagus. Echocardiography and CT angiography can inform the diagnosis.

Global Scatterometer Observations of the Structure of Tropical Cyclone Wind Fields

2020 ◽  
Vol 148 (11) ◽  
pp. 4673-4692
Author(s):  
Ali Tamizi ◽  
Ian R. Young ◽  
Agustinus Ribal ◽  
Jose-Henrique Alves
Keyword(s):  
Tropical Cyclone ◽  
Surface Wind ◽  
Radial Distance ◽  
Wind Fields ◽  
Forward Movement ◽  
Left Right Asymmetry ◽  
The Right ◽  
Very Large Database ◽  
Left Front ◽  
Tropical Cyclone Center

AbstractA very large database containing 24 years of scatterometer passes is analyzed to investigate the surface wind fields within tropical cyclones. The analysis confirms the left–right asymmetry of the wind field with the strongest winds directly to the right of the tropical cyclone center (Northern Hemisphere). At values greater than 2 times the radius to maximum winds, the asymmetry is approximately equal to the storm velocity of forward movement. Observed wind inflow angle (i.e., storm motion not subtracted) is shown to vary both radially and azimuthally within the tropical cyclone. The smallest observed wind inflow angles are found in the left-front quadrant with the largest values in the right-rear quadrant. As the velocity of forward movement increases and the central pressure decreases, observed inflow angles ahead of the storm decrease and those behind the storm increase. In the right-rear quadrant, the observed inflow angle increases with radius from the storm center. In all other quadrants, the observed inflow angle is approximately constant as a function of radial distance.

scholarly journals Cerberus–Nodal–Lefty–Pitx signaling cascade controls left–right asymmetry in amphioxus

2017 ◽  
Vol 114 (14) ◽  
pp. 3684-3689 ◽  
Author(s):  
Guang Li ◽  
Xian Liu ◽  
Chaofan Xing ◽  
Huayang Zhang ◽  
Sebastian M. Shimeld ◽  
...  
Keyword(s):  
Gene Expression ◽  
Transcription Factor ◽  
Feedback Loops ◽  
Signaling Cascade ◽  
Nodal Signaling ◽  
Transcription Activator ◽  
Gene Expression Cassette ◽  
Left Right Asymmetry ◽  
The Right ◽  
Target Transcription Factor

Many bilaterally symmetrical animals develop genetically programmed left–right asymmetries. In vertebrates, this process is under the control of Nodal signaling, which is restricted to the left side by Nodal antagonists Cerberus and Lefty. Amphioxus, the earliest diverging chordate lineage, has profound left–right asymmetry as a larva. We show that Cerberus, Nodal, Lefty, and their target transcription factor Pitx are sequentially activated in amphioxus embryos. We then address their function by transcription activator-like effector nucleases (TALEN)-based knockout and heat-shock promoter (HSP)-driven overexpression. Knockout of Cerberus leads to ectopic right-sided expression of Nodal, Lefty, and Pitx, whereas overexpression of Cerberus represses their left-sided expression. Overexpression of Nodal in turn represses Cerberus and activates Lefty and Pitx ectopically on the right side. We also show Lefty represses Nodal, whereas Pitx activates Nodal. These data combine in a model in which Cerberus determines whether the left-sided gene expression cassette is activated or repressed. These regulatory steps are essential for normal left–right asymmetry to develop, as when they are disrupted embryos may instead form two phenotypic left sides or two phenotypic right sides. Our study shows the regulatory cassette controlling left–right asymmetry was in place in the ancestor of amphioxus and vertebrates. This includes the Nodal inhibitors Cerberus and Lefty, both of which operate in feedback loops with Nodal and combine to establish asymmetric Pitx expression. Cerberus and Lefty are missing from most invertebrate lineages, marking this mechanism as an innovation in the lineage leading to modern chordates.

scholarly journals Nodal signalling in Xenopus : the role of Xnr5 in left/right asymmetry and heart development

Open Biology ◽  
2016 ◽  
Vol 6 (8) ◽  
pp. 150187 ◽  
Author(s):  
Emmanuel Tadjuidje ◽  
Matthew Kofron ◽  
Adnan Mir ◽  
Christopher Wylie ◽  
Janet Heasman ◽  
...  
Keyword(s):  
Heart Development ◽  
Cardiac Troponin ◽  
Axis Formation ◽  
Mrna Levels ◽  
Blastula Stage ◽  
Signalling Molecules ◽  
Tailbud Stage ◽  
Heart Field ◽  
Left Right Asymmetry

Nodal class TGF-β signalling molecules play essential roles in establishing the vertebrate body plan. In all vertebrates, nodal family members have specific waves of expression required for tissue specification and axis formation. In Xenopus laevis , six nodal genes are expressed before gastrulation, raising the question of whether they have specific roles or act redundantly with each other. Here, we examine the role of Xnr5. We find it acts at the late blastula stage as a mesoderm inducer and repressor of ectodermal gene expression, a role it shares with Vg1. However, unlike Vg1, Xnr5 depletion reduces the expression of the nodal family member xnr1 at the gastrula stage. It is also required for left/right laterality by controlling the expression of the laterality genes xnr1, antivin ( lefty ) and pitx2 at the tailbud stage. In Xnr5-depleted embryos, the heart field is established normally, but symmetrical reduction in Xnr5 levels causes a severely stunted midline heart, first evidenced by a reduction in cardiac troponin mRNA levels, while left-sided reduction leads to randomization of the left/right axis. This work identifies Xnr5 as the earliest step in the signalling pathway establishing normal heart laterality in Xenopus .

scholarly journals From zebrafish heart jogging genes to mouse and human orthologs: using Gene Ontology to investigate mammalian heart development.

F1000Research ◽  
2014 ◽  
Vol 2 ◽  
pp. 242 ◽  
Author(s):  
Varsha K Khodiyar ◽  
Doug Howe ◽  
Philippa J Talmud ◽  
Ross Breckenridge ◽  
Ruth C Lovering
Keyword(s):  
Gene Ontology ◽  
Heart Development ◽  
Nervous System Development ◽  
Model Organisms ◽  
Ontology Term ◽  
Developmental Processes ◽  
Cellular Processes ◽  
Mammalian Heart ◽  
Left Right Asymmetry ◽  
Zebrafish Heart

For the majority of organs in developing vertebrate embryos, left-right asymmetry is controlled by a ciliated region; the left-right organizer node in the mouse and human, and the Kuppfer’s vesicle in the zebrafish. In the zebrafish, laterality cues from the Kuppfer’s vesicle determine asymmetry in the developing heart, the direction of ‘heart jogging’ and the direction of ‘heart looping’.  ‘Heart jogging’ is the term given to the process by which the symmetrical zebrafish heart tube is displaced relative to the dorsal midline, with a leftward ‘jog’. Heart jogging is not considered to occur in mammals, although a leftward shift of the developing mouse caudal heart does occur prior to looping, which may be analogous to zebrafish heart jogging. Previous studies have characterized 30 genes involved in zebrafish heart jogging, the majority of which have well defined orthologs in mouse and human and many of these orthologs have been associated with early mammalian heart development. We undertook manual curation of a specific set of genes associated with heart development and we describe the use of Gene Ontology term enrichment analyses to examine the cellular processes associated with heart jogging.  We found that the human, mouse and zebrafish ‘heart jogging orthologs’ are involved in similar organ developmental processes across the three species, such as heart, kidney and nervous system development, as well as more specific cellular processes such as cilium development and function. The results of these analyses are consistent with a role for cilia in the determination of left-right asymmetry of many internal organs, in addition to their known role in zebrafish heart jogging. This study highlights the importance of model organisms in the study of human heart development, and emphasises both the conservation and divergence of developmental processes across vertebrates, as well as the limitations of this approach.

scholarly journals The Determination Factors of Left-Right Asymmetry Disorders - a Short Review

2017 ◽  
Vol 90 (2) ◽  
pp. 139-146 ◽  
Author(s):  
Andreea Catana ◽  
Adina Patricia Apostu
Keyword(s):  
Heart Defects ◽  
Short Review ◽  
Model Organisms ◽  
Rare Disorders ◽  
Clinical Complexity ◽  
Genetic And Environmental Factors ◽  
Left Right Asymmetry ◽  
The Right ◽  
Laterality Defects ◽  
Clinical Problems

Laterality defects in humans, situs inversus and heterotaxy, are rare disorders, with an incidence of 1:8000 to 1:10 000 in the general population, and a multifactorial etiology. It has been proved that 1.44/10 000 of all cardiac problems are associated with malformations of left-right asymmetry and heterotaxy accounts for 3% of all congenital heart defects. It is considered that defects of situs appear due to genetic and environmental factors. Also, there is evidence that the ciliopathies (defects of structure or function) are involved in development abnormalities. Over 100 genes have been reported to be involved in left-right patterning in model organisms, but only a few are likely to candidate for left-right asymmetry defects in humans. Left-right asymmetry disorders are genetically heterogeneous and have variable manifestations (from asymptomatic to serious clinical problems). The discovery of the right mechanism of left-right development will help explain the clinical complexity and may contribute to a therapy of these disorders.

The homeobox gene Pitx2: mediator of asymmetric left-right signaling in vertebrate heart and gut looping

Development ◽  
1999 ◽  
Vol 126 (6) ◽  
pp. 1225-1234 ◽  
Author(s):  
M. Campione ◽  
H. Steinbeisser ◽  
A. Schweickert ◽  
K. Deissler ◽  
F. van Bebber ◽  
...  
Keyword(s):  
Ectopic Expression ◽  
Homeobox Gene ◽  
Zebrafish Embryos ◽  
Lateral Plate Mesoderm ◽  
Lateral Plate ◽  
Left Right Asymmetry ◽  
The Right ◽  
Pitx2 Expression

Left-right asymmetry in vertebrates is controlled by activities emanating from the left lateral plate. How these signals get transmitted to the forming organs is not known. A candidate mediator in mouse, frog and zebrafish embryos is the homeobox gene Pitx2. It is asymmetrically expressed in the left lateral plate mesoderm, tubular heart and early gut tube. Localized Pitx2 expression continues when these organs undergo asymmetric looping morphogenesis. Ectopic expression of Xnr1 in the right lateral plate induces Pitx2 transcription in Xenopus. Misexpression of Pitx2 affects situs and morphology of organs. These experiments suggest a role for Pitx2 in promoting looping of the linear heart and gut.

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