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Robert H Anderson - One of the best experts on this subject based on the ideXlab platform.
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timing of fontan completion in children with functionally univentricular hearts and Isomerism the impact of age weight and pre fontan arterial oxygen saturation
Pediatric Cardiology, 2019Co-Authors: Peter C Frommelt, Saul Flores, Robert H Anderson, Rohit Loomba, James S TweddellAbstract:Isomerism, or heterotaxy, impacts morbidity and mortality after various stages of univentricular palliation. Timing of Fontan completing in these patients based on preoperative factors has not been investigated previously. The aim of this study was to determine the impact of preoperative factors on various outcomes including length of hospital stay and duration of chest tubes. A cross-sectional study was conducted. Patients with Isomerism having undergone Fontan at the Children’s Hospital of Wisconsin between 1998 and 2014 were identified. Preoperative, operative, and postoperative data were collected on these patients. Linear regression analysis was conducted to determine preoperative characteristics associated with various postoperative outcomes. Receiver operator curve analysis was also performed to determine the sensitivity and specificity of age and pre-Fontan arterial oxygen saturation in predicting increased length of hospitalization and increased duration of chest tubes. Younger age and lower pre-Fontan arterial oxygen saturation were associated with increased length of hospitalization while younger age, lower pre-Fontan arterial oxygen saturation, interrupted inferior caval vein, and worse pre-Fontan atrioventricular valve regurgitation were associated with increased length of chest tubes. Age, arterial oxygen saturation, pulmonary arteriovenous malformations, interruption of the inferior caval vein, and atrioventricular valve regurgitation should all be taken into consideration when timing Fontan completion in patients with Isomerism. Arterial oxygen saturations between 82 and 84% with an approximate age of 3 years appear to be a time at which it is reasonable to consider Fontan in patients with Isomerism.
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Is an Appreciation of Isomerism the Key to Unlocking the Mysteries of the Cardiac Findings in Heterotaxy?
MDPI AG, 2018Co-Authors: Robert H Anderson, Diane E Spicer, Rohit LoombaAbstract:Pediatric cardiologists treating patients with severe congenital cardiac defects define “visceral heterotaxy” on the basis of Isomerism of the atrial appendages. The isomeric features represent an obvious manifestation of disruption of left-right asymmetry during embryonic development. Thus, there are two subsets of individuals within the overall syndrome, with features of either right or left Isomerism. Within the heart, it is only the atrial appendages that are truly isomeric. The remainder of the cardiac components shows variable morphology, as does the arrangement of the remaining body organs. Order is provided in this potentially chaotic arrangement simply by describing the specific features of each of the systems. These features as defined by clinicians, however, seem less well recognized by those investigating the developmental origins of the disruption of symmetry. Developmental biologists place much greater emphasis on ventricular looping. Although the direction of the loop can certainly be interpreted as representing an example of asymmetry, it is not comparable to the isomeric features that underscore the clinical syndromes. This is because, thus far, there is no evidence of ventricular Isomerism, with the ventricles distinguished one from the other on the basis of their disparate anatomical features. In similar fashion, some consider transposition to represent abnormal lateralization, but again, clinical diagnosis depends on recognition of the lateralized features. In this review, therefore, we discuss the key questions that currently underscore the mismatch in the approaches to “lateralization” as taken by clinicians and developmental biologists
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segregating bodily Isomerism or heterotaxy potential echocardiographic correlations of morphological findings
Cardiology in The Young, 2017Co-Authors: Cornelia Tremblay, Peter C Frommelt, Rohit Loomba, Donald G Perrin, Diane E Spicer, Carl L Backer, Robert H AndersonAbstract:BACKGROUND Bodily Isomerism, also referred to as heterotaxy, involves predominantly the thoracic organs, although other organs are usually abnormally positioned. Previously assessed on the basis of splenic anatomy, it is now understood that Isomerism is better segregated on the basis of atrial appendage morphology. This allows for anticipation of associated findings. We aimed to assess the accuracy of segregation based on the morphology of the atrial appendages and other structures more easily identified by echocardiography. METHODS We reviewed postmortem specimens of hearts from the archives at four institutions categorised as obtained from patients with "heterotaxy". The cardiac structures were analysed using sequential segmental analysis. Non-cardiac structures were also examined if available. Statistical analyses were performed to compare differences in the settings of right as opposed to left Isomerism. RESULTS Specimens were available from 188 patients. Of these, 57 had left Isomerism, and 131 had right Isomerism. Atrial appendages were isomeric in all patients. A coronary sinus was found only in left Isomerism, whereas a terminal crest, or a Eustachian valve, was found only in right Isomerism. Interruption of the inferior caval vein was associated with left Isomerism, whereas totally anomalous pulmonary venous connection was associated with right Isomerism. CONCLUSION Isomerism is uniformly segregated on the basis of the morphology of the atrial appendages, itself defined by the extent of the pectinate muscles. Other features such as the presence of a coronary sinus and systemic venous return can further help with such segregation of Isomerism.
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Isomerism in the setting of the so-called “heterotaxy”: The usefulness of computed tomographic analysis
Wolters Kluwer Medknow Publications, 2017Co-Authors: Shumpei Mori, Robert H Anderson, Tatsuya Nishii, Kensuke Matsumoto, Rohit S LoombaAbstract:The most complex combinations of congenital cardiac malformations are found in the setting of bodily Isomerism. The question remains, however, as to whether evidence of cardiac Isomerism is always to be found in the setting of bodily Isomerism, also known as “heterotaxy.” We have previously shown that, when assessed on the basis of the extent of the pectinate muscles relative to the atrioventricular junctions, there is always Isomerism of the atrial appendages in this setting. Doubt has been remained, however, as to whether these cardiac features can accurately be recognized during life. We have now encountered two patients showing features of the left and right bodily Isomerism. Examinations of these patients made using computed tomography show that all features of Isomerism, no matter how complex, can now be visualized during life. The images currently presented show, furthermore, that the features of the so-called “heterotaxy” can be seen during life, not only within the heart but also in all the thoracic and abdominal organs, albeit that the isomeric features are confined to the thoracic organs. Based on the images presented, we argue that if each system of organs is analyzed and described in independent fashion; then it is possible for clinicians to exclude any suggestion of ambiguity and to provide accurate descriptions of the overall arrangement. We further discuss the appropriate terminology to describe the entity we prefer to call Isomerism, along with the indications and usefulness of computed tomography in revealing the anatomic features of the congenitally malformed heart
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manifestations of bodily Isomerism
Cardiovascular Pathology, 2016Co-Authors: Rohit Loomba, Diane E Spicer, Carl L Backer, Muhammad Mustafa Ahmed, Robert H AndersonAbstract:We report the findings present in 49 postmortem specimens from patients with so-called heterotaxy, concentrating on those found in the extracardiac systems of organs. Also known as bodily Isomerism, we suggest that it is important to segregate the syndromes into their isomeric subtypes to be able to make inferences regarding likely extracardiac and intracardiac findings to allow for proper surveillance. We demonstrate that this is best done on the basis of the atrial appendages, which were isomeric in all the hearts obtained from the specimens available for our inspection. The abdominal organs do not demonstrate Isomerism, and they show variable features when compared to the isomeric atrial appendages.
M Imlau - One of the best experts on this subject based on the ideXlab platform.
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high contrast high resolution photochromic silicone polymer based on photoswitchable ru bpy 2 oso pf 6 building blocks
Photonics Research, 2013Co-Authors: Kristin Springfeld, Volker Dieckmann, M ImlauAbstract:The implementation of photoinduced linkage Isomerism in molecular-based optical materials represents a promising approach for the synthesis of high-contrast, high-resolution photosensitive materials that are necessary for high-density (holographic) data storage and/or real-three-dimensional (holographic) displays. The unsolved task of embedding a photofunctional coordination complex into a matrix like polymer polydimethylsiloxane (PDMS) with photoinduced Isomerism of a SO-bond in the sulfoxide compound [Ru(bpy)2OSO]PF6 is addressed. This approach allows to preserve the spectral properties within the solid dielectric environment, with an impact of PDMS on population and relaxation dynamics. All data are discussed in the framework of photofunctionality, storage, and display applications.
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pronounced photosensitivity of molecular ru bpy 2 oso solutions based on two photoinduced linkage isomers
Optics Express, 2009Co-Authors: Volker Dieckmann, Sebastian Eicke, Jeffrey J Rack, Theo Woike, M ImlauAbstract:Photosensitive properties of [Ru(bpy)2(OSO)] ∙ PF6 dissolved in propylene carbonate originating from photoinduced linkage Isomerism have been studied by temperature and exposure dependent transmission and UV/Vis absorption spectroscopy. An exceeding photochromic photosensitivity of S = (63 ± 10) × 103 cm l J−1 mol−1 is determined. It is attributed to a maximum population of 100% molecules in the photoinduced isomers, a unique absorption cross section per molecule and a very low light exposure of Q0 = (0.25 ± 0.03) Ws cm−2 for Isomerism. Relaxation studies of O-bonded to S-bonded isomers at different temperatures verify the existence of two distinct structures of linkage isomers determined by the activation energies of EA,1 = (0.76 ± 0.08) eV and EA,2 = (1.00 ± 0.14) eV.
Lindsey D. Allan - One of the best experts on this subject based on the ideXlab platform.
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prenatal diagnosis of left atrial Isomerism
Heart, 2009Co-Authors: Spyridon Pepes, Vita Zidere, Lindsey D. AllanAbstract:Objective: To describe the cardiac anomalies and outcome in the fetus with left atrial Isomerism. Methods: All fetuses with a diagnosis of left atrial Isomerism between 1998 and 2008 were identified. Gestational age at diagnosis, the nuchal translucency, the karyotype, the cardiac findings and outcome were noted. A literature search from 1990 identified four publications reporting 10 or more cases of fetal left atrial Isomerism. The same data, where available, were collected from these papers for comparison. Results: There were 41 fetuses with this diagnosis seen in our centre. All cases had an interrupted inferior vena cava with azygous continuation. Associated cardiac defects were similar in our series and in the 129 cases reported in the literature and are therefore grouped together. They included complete atrioventricular septal defect (68%), complete heart block (38%), viscerocardiac heterotaxy (54%), double outlet right ventricle (23%), right ventricular outflow tract obstruction (35%), left ventricular outflow tract obstruction (21%) and total anomalous pulmonary vein drainage (5%). In our series, there were 22 pregnancy terminations, seven intrauterine deaths, one neonatal death, one infant death and one was lost to follow-up. Of the continuing pregnancies only 50% in our series and 60% in the reported series survived. Conclusion: Left atrial Isomerism presents a varied spectrum of cardiac malformations when it is detected prenatally. Complete heart block, complex cardiac abnormalities and fetal hydrops are poor prognostic features. Those with only minor cardiac malformations are at risk postnatally for biliary atresia and for bowel obstruction due to malrotation.
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color atlas of fetal cardiology
1994Co-Authors: Lindsey D. Allan, Gurleen Sharland, Ac CookAbstract:The normal foetal heart anomalies of venous connection atrial Isomerism the atrial septum atrioventricular defects univentricular atrioventricular connection ventricular septal defects anomalies of the atrioventricular valves hypoplastic right and left ventricles pulmonary and aortic stenosis tetralogy of fallot complete transposition corrected transpostion double outlet right ventricle common arterial trunk aortic interruption and coarctation cardiac tumours miscellaneous anomalies.
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disposition of the atrioventricular conduction tissues in the heart with Isomerism of the atrial appendages its relation to congenital complete heart block
Journal of the American College of Cardiology, 1992Co-Authors: Nuala Fagg, Robert H Anderson, Andrew C Cook, Lindsey D. AllanAbstract:Abstract Objectives . Our goal was to compare histologically the mechanisms producing congenital complete heart block in normally structured hearts and in hearts with Isomerism of the atrial appendages. Background . It is known that several different histologic patterns can underscore the existence of congenital complete heart block in the normally structured heart, and that block is particularly frequent in the setting of Isomerism of the atrial appendages. The histologic findings in the latter setting were compared and contrasted with those found in the normally structured heart. Methods . Serial section techniques were used to study 14 hearts with Isomerism of the atrial appendage (12 with left Isomerism and 2 with right Isomerism) and 7 normally structured hearts. Results . Discontinuity between the atrioventricular (AV) node and the ventricular conduction tissues was found in 10 of the 12 hearts with left Isomerism; the other 2 hearts had a normally formed conduction axis and heart block was not present in these cases. In both hearts with right Isomerism, “slings” of ventricular conduction tissue connected dual AV nodes; congenital complete heart block was not present in either case. In six of the seven cases with a normally structured heart, anti-Ro antibodies had been found in the maternal serum. All six of these hearts had discontinuity between the atrial tissues and the ventricular conduction axis. Intraventricular discontinuity was found in the seventh case, in which anti-Ro antibodies were not found in the mother. Conclusions . The pattern of congenital complete heart block in cases with left Isomerism is discontinuity between the AV node and the conduction axis, in contrast to the pattern of atrial-axis discontinuity produced in the normally structured heart when anti-Ro antibodies are found in the maternal serum.
Prasad V Bharatam - One of the best experts on this subject based on the ideXlab platform.
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geometrical Isomerism in guanabenz free base synthesis characterization crystal structure and theoretical studies
Crystal Growth & Design, 2019Co-Authors: Deepika Kathuria, Sumit S Chourasiya, Aabid Abdullah Wani, Manjeet Singh, Subash Chandra Sahoo, Prasad V BharatamAbstract:Guanabenz is a drug used for the treatment of hypertension, and it exhibits Isomerism and tautomerism. In this article, X-ray diffraction studies (single crystal and powder) as well as thermochemical analysis on the guanabenz have been reported. The results indicated that E/Z-Isomerism in guanabenz is responsible for the identification of two solid forms, Form I (E-isomer) and Form II (Z-isomer). These two forms may be treated as geometrical polymorphs. Form I of guanabenz was already known. Identification of Form II and its X-ray structure are reported first time in this article. Quantum chemical analysis and two-dimensional fingerprint plots as Hirshfeld surfaces of these two forms highlight the differences in intermolecular hydrogen bonding, energy differences, and π-stacking interactions. The quantum chemical studies indicate that Form I (E-isomer) is more stable than Form II (Z-isomer) by 2.13 kcal/mol. The presence of Form II in the crystal structure has been rationalized by quantum chemical calcula...
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Geometrical Isomerism in Guanabenz Free Base: Synthesis, Characterization, Crystal Structure, and Theoretical Studies
2019Co-Authors: Deepika Kathuria, Sumit S Chourasiya, Aabid Abdullah Wani, Manjeet Singh, Subash Chandra Sahoo, Prasad V BharatamAbstract:Guanabenz is a drug used for the treatment of hypertension, and it exhibits Isomerism and tautomerism. In this article, X-ray diffraction studies (single crystal and powder) as well as thermochemical analysis on the guanabenz have been reported. The results indicated that E/Z-Isomerism in guanabenz is responsible for the identification of two solid forms, Form I (E-isomer) and Form II (Z-isomer). These two forms may be treated as geometrical polymorphs. Form I of guanabenz was already known. Identification of Form II and its X-ray structure are reported first time in this article. Quantum chemical analysis and two-dimensional fingerprint plots as Hirshfeld surfaces of these two forms highlight the differences in intermolecular hydrogen bonding, energy differences, and π-stacking interactions. The quantum chemical studies indicate that Form I (E-isomer) is more stable than Form II (Z-isomer) by 2.13 kcal/mol. The presence of Form II in the crystal structure has been rationalized by quantum chemical calculations on the basis of dimerization energies that suggest that the dimer of the Z-isomer is more stable than the dimer of the E-isomer by ∼7 kcal/mol
Deepika Kathuria - One of the best experts on this subject based on the ideXlab platform.
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geometrical Isomerism in guanabenz free base synthesis characterization crystal structure and theoretical studies
Crystal Growth & Design, 2019Co-Authors: Deepika Kathuria, Sumit S Chourasiya, Aabid Abdullah Wani, Manjeet Singh, Subash Chandra Sahoo, Prasad V BharatamAbstract:Guanabenz is a drug used for the treatment of hypertension, and it exhibits Isomerism and tautomerism. In this article, X-ray diffraction studies (single crystal and powder) as well as thermochemical analysis on the guanabenz have been reported. The results indicated that E/Z-Isomerism in guanabenz is responsible for the identification of two solid forms, Form I (E-isomer) and Form II (Z-isomer). These two forms may be treated as geometrical polymorphs. Form I of guanabenz was already known. Identification of Form II and its X-ray structure are reported first time in this article. Quantum chemical analysis and two-dimensional fingerprint plots as Hirshfeld surfaces of these two forms highlight the differences in intermolecular hydrogen bonding, energy differences, and π-stacking interactions. The quantum chemical studies indicate that Form I (E-isomer) is more stable than Form II (Z-isomer) by 2.13 kcal/mol. The presence of Form II in the crystal structure has been rationalized by quantum chemical calcula...
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Geometrical Isomerism in Guanabenz Free Base: Synthesis, Characterization, Crystal Structure, and Theoretical Studies
2019Co-Authors: Deepika Kathuria, Sumit S Chourasiya, Aabid Abdullah Wani, Manjeet Singh, Subash Chandra Sahoo, Prasad V BharatamAbstract:Guanabenz is a drug used for the treatment of hypertension, and it exhibits Isomerism and tautomerism. In this article, X-ray diffraction studies (single crystal and powder) as well as thermochemical analysis on the guanabenz have been reported. The results indicated that E/Z-Isomerism in guanabenz is responsible for the identification of two solid forms, Form I (E-isomer) and Form II (Z-isomer). These two forms may be treated as geometrical polymorphs. Form I of guanabenz was already known. Identification of Form II and its X-ray structure are reported first time in this article. Quantum chemical analysis and two-dimensional fingerprint plots as Hirshfeld surfaces of these two forms highlight the differences in intermolecular hydrogen bonding, energy differences, and π-stacking interactions. The quantum chemical studies indicate that Form I (E-isomer) is more stable than Form II (Z-isomer) by 2.13 kcal/mol. The presence of Form II in the crystal structure has been rationalized by quantum chemical calculations on the basis of dimerization energies that suggest that the dimer of the Z-isomer is more stable than the dimer of the E-isomer by ∼7 kcal/mol
