bluuebunny/crossref_metadata_2025_split huggingface dataset:
An ontology of human developmental anatomy
Authors: Hunter Amy , Kaufman Matthew H. , McKay Angus , Baldock Richard , Simmen Martin W. , Bard Jonathan B. L. 
Published: October 2003

AbstractHuman developmental anatomy has been organized as structured lists of the major constituent tissues present during each of Carnegie stages 1–20 (E1–E50, ∼8500 anatomically defined tissue items). For each of these stages, the tissues have been organized as a hierarchy in which an individual tissue is catalogued as part of a larger tissue. Such a formal representation of knowledge is known as an ontology and this anatomical ontology can be used in databases to store, organize and search for data associated with the tissues present at each developmental stage. The anatomical data for compiling these hierarchies comes from the literature, from observations on embryos in the Patten Collection (Ann Arbor, MI, USA) and from comparisons with mouse tissues at similar stages of development. The ontology is available in three versions. The first gives hierarchies of the named tissues present at each Carnegie stage (http://www.ana.ed.ac.uk/anatomy/database/humat/) and is intended to help analyse both normal and abnormal human embryos; it carries hyperlinked notes on some ambiguities in the literature that have been clarified through analysing sectioned material. The second contains many additional subsidiary tissue domains and is intended for handling tissue‐associated data (e.g. gene‐expression) in a database. This version is available at the humat site and at http://genex.hgu.mrc.ac.uk/Resources/intro.html/), and has been designed to be interoperable with the ontology for mouse developmental anatomy, also available at the genex site. The third gives the second version in GO ontology syntax (with standard IDs for each tissue) and can be downloaded from both the genex and the Open Biological Ontology sites (http://obo.sourceforge.net/)
A simple method of culture of 11.5‐day‐old rat embryos in DMEM/F12 and 20% fetal bovine serum
Authors: Ornoy A. , Yacobi S. , Yaffee P. 
Published: October 2003

AbstractPost‐implantation mouse and rat embryos are usually cultured in sera obtained from various rodents and from humans. We describe here a simple and inexpensive culture medium – Dulbecco's minimal essential medium/Ham's F12 (DMEM/F12) supplemented with 20% fetal bovine serum (FBS) – in which E11.5 rat embryos of the Hebrew University Sabra strain grow for 28 h slightly better than in heat‐inactivated 90% rat serum with 10% distilled water and addition of 1 mg mL−1glucose. They have good growth and development and a low rate of anomalies, similar to that observed in embryos cultured on rat serum. Their size, total score and olfactory system development is slightly higher than in rat embryos cultured in rat serum. About 7.2% of these embryos exhibit subcutaneous haemorrhages in various areas, but these do not seem to interfere with their growth and development. This method is not appropriate for younger embryos; in E10.5 embryos cultured for 28 h we found increased embryonic death and anomalies.
In situ hybridization and immunohistochemistry of versican, aggrecan and link protein, and histochemistry of hyaluronan in the developing mouse limb bud cartilage
Authors: Shibata S. , Fukada K. , Imai H. , Abe T. , Yamashita Y. 
Published: October 2003

AbstractWe investigated the expression pattern of versican, aggrecan, link protein and hyaluronan in the developing limb bud cartilage of the fetal mouse using in situ hybridization and/or immunohistochemistry. Versican mRNA and immunostaining were detected in the mesenchymal cell condensation of the future digital bone at E13. Versican mRNA expression rapidly disappeared from the tibial cartilage, as cartilage formation progressed during E13–15, but the immunostaining was gradually replaced by aggrecan immunostaining from the diaphysis. Immunostaining for both molecules thus had a ‘nega‐posi’ pattern and consequently versican immunostaining was still detected at the epiphyseal end at E15. This result indicated that versican functions as a temporary framework in newly formed cartilage matrix. An aggrecan‐positive region within the cartilage invariably had intense hyaluronan staining, whereas a versican‐positive region also had affinity for hyaluronan within the cartilage, but not in the mesenchymal cell condensation. Therefore, the presence of versican aggregates was not confirmed in the developing limb bud cartilage. Furthermore, although link protein was more closely related with aggrecan than versican during limb bud cartilage formation, there was a discrepancy between the expression of aggrecan and link protein in tibial cartilage at E15. In particular, only a link protein‐positive region was present in the marginal area of the metaphysis and the epiphysis at this stage. This finding may indicate a novel role for link protein.
How to measure the increase in elastic system fibres in the lamina propria of the uterine cervix of pregnant rats
Authors: Battlehner C. N. , Caldini E. G. , Pereira J. C. R. , Luque E. H. , Montes G. S. 
Published: October 2003

AbstractAs the uterus enlarges to accommodate the growing fetus during pregnancy, the cervix behaves essentially as a barrier. During ripening and delivery, it needs to become soft and distensible to allow dilation and the passage of the conceptus. As the transformations of the collagen‐containing fibres are known to be essential for ripening and delivery, it has been hypothesized that the elastic system fibres, owing to their intrinsic mechanical properties (reversible extensibility), could be involved in the shape‐recovering process immediately after delivery. In sections stained by Weigert's resorcin–fuchsin (with previous oxidation), we describe the elastic system fibres in the lamina propria of the rat uterine cervix. They are distributed following different patterns when in the endocervix or in the ectocervical–vaginal region. A third distinctive pattern (named the ‘elastic tendon’) is described here for the first time in the uterine–cervical transition. A special morphometrical protocol has been designed in order to overcome problems during the quantification process. Using the so‐called intercept counting method, it was possible to demonstrate that the elastic system fibres are increased in the cervix at the end of pregnancy. They may be involved in the immediate shape‐recovering of the cervix after delivery as well as in helping to strengthen the anchoring of the epithelium to the lamina propria, thus minimizing birth trauma.
Postnatal changes in caldesmon expression and localization in cardiac myocytes
Authors: McMartin Gail A. , Wirch Erwin , Abraham Natalia , Kargacin Gary J. 
Published: October 2003

AbstractCaldesmon is a heat‐stable protein found in both muscle and non‐muscle tissue. It binds to a number of contractile and cytoskeletal proteins and may be involved in regulating acto‐myosin interaction in smooth muscle cells and/or the assembly of microfilaments in muscle and non‐muscle cells. We have shown previously that caldesmon is localized at the Z‐lines in adult cardiac myocytes and that both the low‐ and high‐molecular‐weight forms (l‐caldesmon and h‐caldesmon, respectively) are present in atrial and ventricular myocytes. Here we examined the expression of caldesmon and its localization in freshly isolated cardiac myocytes during postnatal development and when these myocytes were grown in culture. We found that l‐caldesmon is expressed in both neonatal and adult rat ventricular myocytes. The expression of h‐caldesmon, however, was not detected in myocytes from newborn animals but increased during the first 2 weeks of postnatal development. Caldesmon was generally not co‐localized with α‐actinin at the Z‐lines in neonatal myocytes but became increasingly more so during the first 2 weeks of postnatal development. When myocytes from 5‐ and 10‐day‐old rats were grown in primary culture, h‐caldesmon expression decreased and caldesmon could not be detected at the Z‐lines in the cultured cells. These results indicate that caldesmon plays a role at the Z‐lines in adult cardiac myocytes; however, its localization at the Z‐lines is not necessary for the prenatal development that occurs at these sites or for the establishment of a contractile phenotype in cultured cardiac myocytes.
The role of retinoic acid in the morphogenesis of the neural tube
Authors: Wilson L. , Gale E. , Maden M. 
Published: October 2003

AbstractWe have examined the role of the signalling molecule, retinoic acid, in the process of neurulation and the subsequent growth and differentiation of the central nervous system using quail embryos that have developed in the absence of retinoic acid. Such retinoic acid‐free embryos undergo abnormal neural tube formation in terms of its shape and structure, but the embryos do not display spina bifida or exencephaly. The neural tubes have a wider floor plate, a thicker roof plate and a different dorsoventral shape. Phalloidin staining and electron microscopy revealed alterations in the actin filaments and the junctional complexes of the cell layer lining the lumen. Initially the neural tubes proliferated at the same rate as normal, but later the proliferation rate declined drastically and neuronal differentiation was highly deficient. There were very few motoneurons extending neurites into the periphery, and within the neural tube axon trajectories were chaotic. These results reveal several functions for retinoic acid in the morphogenesis and growth of the neural tube, many of which can be explained by defective notochord signalling, but they do not suggest that this molecule plays a role in neural tube closure.
Morphological analysis of leucocyte transmigration in the pleural cavity
Authors: Teng R. , Johkura K. , Ogiwara N. , Zhao X. , Cui L. , Iida I. , Okouchi Y. , Asanuma K. , Sasaki K. 
Published: October 2003

AbstractThe role that pleural mesothelial cells play in leucocyte transmigration into the pleural cavity was investigated in lipopolysaccharide‐stimulated mice. Changes in mesothelial cell morphology and changes in expression of adhesion molecules on mesothelial cells and leucocytes were analysed by light microscopy, immunohistochemistry, transmission electron microscopy (TEM) and immuno‐scanning electron microscopy (immuno‐SEM). After stimulation, the mesothelial cells separated completely from one another before leucocyte penetration across the mesothelial layer occurred. These changes occurred primarily in the immediate vicinity of ribs, where a large number of leucocytes accumulated. Immuno‐SEM showed that the expression of intercellular adhesion molecule‐1 (ICAM‐1) on the parietal pleural mesothelial cells was significantly up‐regulated by lipopolysaccharide stimulation, and that of vascular cell adhesion molecule‐1 (VCAM‐1) was induced. Both were restricted to the microvilli of the mesothelial cells. By contrast, expression of intercellular adhesion molecule‐2 (ICAM‐2), platelet/endothelial cell adhesion molecule‐1 (PECAM‐1), mucosal addressin cell adhesion molecule‐1 (MAdCAM‐1), endothelial leucocyte adhesion molecule‐1 (ELAM‐1), peripheral node addressin (PNAd) and fibronectin were not detected. Lymphocyte function associated antigen‐1 (LFA‐1), macrophage‐1 molecule (Mac‐1) and very late appearing antigen‐4 (VLA‐4), all ligands of ICAM‐1 and VCAM‐1, were present on the transmigrated neutrophils and macrophages. These findings demonstrate that the immediate vicinity of ribs is a source of leucocyte migration into the pleural space.
One‐Dimensional Rabbit Sinoatrial Node Models:
Authors: GARNY ALAN , KOHL PETER , HUNTER PETER J. , BOYETT MARK R. , NOBLE DENIS 
Published: October 2003

Introduction: Cardiac multicellular modeling has traditionally focused on ventricular electromechanics. More recently, models of the atria have started to emerge, and there is much interest in addressing sinoatrial node structure and function. Methods and Results: We implemented a variety of one‐dimensional sinoatrial models consisting of descriptions of central, transitional, and peripheral sinoatrial node cells, as well as rabbit or human atrial cells. These one‐dimensional models were implemented using CMISS on an SGI® Origin® 2000 supercomputer. Intercellular coupling parameters recorded in experimental studies on sinoatrial node and atrial cell‐pairs under‐represent the electrotonic interactions that any cardiomyocyte would have in a multidimensional setting. Unsurprisingly, cell‐to‐cell coupling had to be scaled‐up (by a factor of 5) in order to obtain a stable leading pacemaker site in the sinoatrial node center. Further critical parameters include the gradual increase in intercellular coupling from sinoatrial node center to periphery, and the presence of electrotonic interaction with atrial cells. Interestingly, the electrotonic effect of the atrium on sinoatrial node periphery is best described as opposing depolarization, rather than necessarily hyperpolarizing, as often assumed. Conclusion: Multicellular one‐dimensional models of sinoatrial node and atrium can provide useful insight into the origin and spread of normal cardiac excitation. They require larger than “physiologic” intercellular conductivities in order to make up for a lack of “anatomical” spatial scaling. Multicellular models for more in‐depth quantitative studies will require more realistic anatomico‐physiologic properties. (J Cardiovasc Electrophysiol, Vol. 14, pp. S121‐S132, October 2003, Suppl.)
Left Atrial Conduction Along the Coronary Sinus During Ectopic Atrial Tachycardia and Atrial Fibrillation:
Authors: CARLSON JONAS , SANTOS SUSANA , PLATONOV PYOTR G. , RASMUSSEN OLE KONGSTAD , JOHANSSON ROLF , OLSSON S. BERTIL 
Published: October 2003

Introduction: Correlation function analysis was applied to endocardial electrograms to investigate conduction patterns along the coronary sinus (CS) during sinus rhythm (SR) and atrial tachycardias. Methods and Results: Eighteen recordings were obtained from 14 patients with supraventricular tachycardias. Five atrial fibrillation (AF) recordings were compared to 10 SR recordings and 3 ectopic atrial tachycardia (EAT) recordings. The maximum correlation coefficient was used to assess similarity between signals, i.e., if they originate from the same wavefront. The cumulative time delay, calculated as pairwise summation of interelectrode time delays, was used as an indicator of activation sequence along the CS. Method validation using SR showed right‐to‐left conduction with high correlations in 8 of 10 recordings indicating one single wavefront. EAT recordings showed consistent left‐to‐right conduction with left atrial foci and right‐to‐left with right atrial focus and lower correlations than SR. All 5 AF recordings showed predominantly left‐to‐right conduction direction, also with correlations lower than SR. Conclusion: (1) Correlation function analysis can be used to assess agreement between signals and direction of activation spread. (2) Due to the position of CS, the results can be used to derive mechanisms of interatrial conduction. (3) Consistency in electrical activity propagation along CS is common in AF. (J Cardiovasc Electrophysiol, Vol. 14, pp. S148‐S153, October 2003, Suppl.)
Frequency Measures Obtained from the Surface Electrocardiogram in Atrial Fibrillation Research and Clinical Decision‐Making
Authors: BOLLMANN ANDREAS , HUSSER DANIELA , STRIDH MARTIN , SOERNMO LEIF , MAJIC MONICA , KLEIN HELMUT U. , OLSSON S. BERTIL 
Published: October 2003

Introduction: Frequency analysis of fibrillation (FAF) and time‐frequency analysis (TFA) were developed recently in order to quantify atrial electrical remodeling in atrial fibrillation (AF) from the surface ECG. This article describes the experience with these two different frequency analysis techniques in consecutive AF patients and discusses possible applications in AF research and clinical decision‐making. Methods and Results: Baseline 2‐minute, high‐gain, high‐resolution ECG recordings using three bipolar leads were obtained from 80 consecutive patients with AF lasting >24 hours. A power spectrum was obtained using Fourier analysis following spatiotemporal QRST cancellation. The dominant fibrillatory rate (in fibrillations per minute [fpm]) was derived (FAF). Stability of the instantaneous fibrillatory rate measured in overlapping 1‐second segments was expressed as the segment proportion with consecutive rate differences <6 fpm (TFA). An adequate power spectrum that could be submitted for determination of fibrillatory rate was obtained in all patients. Dominant atrial rates ranged between 288 and 534 fpm and showed a high correlation (R = 0. 878–0.911, P < 0.001) when assessed from the three different leads. The average instantaneous fibrillatory rate was inversely related with its stability (R =−0.417, P < 0.001). It was closely related with the dominant fibrillatory rate obtained from FAF (R = 0.948, P < 0.001). A literature review revealed that pharmacologic or electrical cardioversion and AF pace termination success rates were highly dependent on fibrillatory rate. Conclusion: Atrial fibrillatory rate and its variability can be reliable obtained from the surface ECG in AF patients. These parameters exhibit a significant interindividual variability allowing individual quantification of the atrial electrical remodeling process and might prove useful for predicting therapy efficacy. (J Cardiovasc Electrophysiol, Vol. 14, pp. S154‐S161, October 2003, Suppl.)
Echocardiographic and Electrocardiographic Predictors for Atrial Fibrillation Recurrence Following Cardioversion
Authors: BOLLMANN ANDREAS , HUSSER DANIELA , STEINERT REIKO , STRIDH MARTIN , SOERNMO LEIF , OLSSON S. BERTIL , POLYWKA DANIELA , MOLLING JOCHEN , GELLER CHRISTOPH , KLEIN HELMUT U. 
Published: October 2003

Introduction: Identification of suitable candidates for cardioversion currently is not based on individual electrical and mechanical atrial remodeling. Therefore, this study analyzed the meaning of atrial fibrillatory rate obtained from the surface ECG (as a measure of electrical remodeling) and left atrial size (as measure of mechanical remodeling) for prediction of early atrial fibrillation (AF) recurrence following cardioversion. Methods and Results: Forty‐four consecutive patients (26 men and 18 women, mean age 62 ± 11 years, no antiarrhythmic medication at baseline) with persistent AF were studied. Fibrillatory rate was obtained from high‐gain, high‐resolution surface ECG using digital signal processing (filtering, QRST subtraction, Fourier analysis) before electrical cardioversion. Univariate and multivariate regression analysis revealed larger systolic left atrial area (Beta = 0.176, P = 0.031) obtained by precardioversion echocardiogram from the apical four‐chamber view and higher atrial fibrillatory rate (Beta = 0.029, P = 0.021) to be independent predictors for AF recurrence (n = 13). Stratification based on the regression equation (electromechanical index [EMI]= 0.176 systolic left atrial area + 0.029 fibrillatory rate − 17.674) allowed identification of groups at low, intermediate, or high risk. No patient with an EMI < −1.85 had early AF recurrence, as opposed to 78% with an EMI > −0.25. Intermediate results (40% recurrence rate) were obtained when the calculated EMI ranged between −1.85 and −0.25 (P < 0.001). Conclusion: Fibrillatory rate obtained from the surface ECG and systolic left atrial area obtained by echocardiography may predict early AF recurrence in patients with persistent AF. These parameters might be useful in identifying candidates with a high likelihood of remaining in sinus rhythm after cardioversion. (J Cardiovasc Electrophysiol, Vol. 14, pp. S162‐S165, October 2003, Suppl.)
Atrial Excitation Assuming Uniform Propagation
Authors: DAM PETER M. van , OOSTEROM ADRIAAN van 
Published: October 2003

Introduction: We investigated the spread of the excitation wave over the atria following initiation in a given focus in an atrial model containing its overall geometry only, i.e., without atrial bundles. Methods and Results: The propagation velocity of the excitation wave was taken to be uniform, and the wall thickness was discarded. The timing of excitation of any point on the atrium thus becomes directly proportional to its shortest distance over the atrial wall to the focus. Despite these gross simplifications, the general nature of the excitation sequence found corresponded closely to clinical data reported in the literature. This suggests that the complex overall geometry of the atria dominates the timing of the excitation. A highly intriguing observation from this study was that, when looking at the pathways from the sinus node to all other points on the atrium, prominent routes became visible even though no such pathways formed part of the model of the atrial geometry used. The locations of these prominent routes coincide with those of various distinct bundles in the atria. Possible inferences of these observations are discussed. Conclusion: Based upon comparison with data from other studies, it is concluded that, during stable heart rhythms, propagation of the atrial excitation wave is well approximated by an assumption of uniform velocity, even though no atrial bundles were included in the model. The overall geometry seems to be the dominant factor in the spread of excitation. (J Cardiovasc Electrophysiol, Vol. 14, pp. S166‐S171, October 2003, Suppl.)
Study of Unipolar Electrogram Morphology in a Computer Model of Atrial Fibrillation
Authors: JACQUEMET VINCENT , VIRAG NATHALIE , IHARA ZENICHI , DANG LAM , BLANC OLIVIER , ZOZOR STEEVE , VESIN JEAN‐MARC , KAPPENBERGER LUKAS , HENRIQUEZ CRAIG 
Published: October 2003

Introduction: Electrograms exhibit a wide variety of morphologies during atrial fibrillation (AF). The basis of these time courses, however, is not completely understood. In this study, data from computer models were studied to relate features of the signals to the underlying dynamics and tissue substrate. Methods and Results: A computer model of entire human atria with a gross fiber architecture based on histology and membrane kinetics based on the Courtemanche et al. atrial model was developed to simulate paced activation and simulated AF. Unipolar electrograms were computed using a current source approximation at 256 sites in right atrium, to simulate a mapping array. The results show the following: (1) In a homogeneous and isotropic tissue, the presence of highly asymmetric electrograms is rare (<2%), although there is a marked variability in amplitude and symmetry. (2) The introduction of anisotropy increases this variability in symmetry and amplitude of the, electrograms especially for propagation across fibers. The percentage of highly asymmetric electrograms increases to 12% to 15% for anisotropy ratios greater than 3:1. (3) Multiphasic and fractionated electrograms are rarely seen in the model with uniform properties but are more common (15%–17%) in a model including regions with abrupt changes in conductivity. Beat‐to‐beat variations in the occurrence of multiphasic signals are possible with fixed anatomic heterogeneity, due to beat‐to‐beat variations in the direction of the wavefront relative to the heterogeneity. Conclusion: Analysis of the amplitude and symmetry of unipolar atrial electrograms can provide information about the electrophysiologic substrate maintaining AF. (J Cardiovasc Electrophysiol, Vol. 14, pp. S172‐S179, October 2003, Suppl.)