Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Double outlet right ventricle in a human embryo (1978)
    Springer
    Virchows Archiv 379 (1978), S. 313-320 
    Details
    ISSN: 1432-2307
    Keywords: Cardiac embryology ; Double outlet right ventricle ; Bulbar ridges ; Bulboventricular fold
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A human embryo of 14 mm crown-rump length is described to exemplify the anomaly of double outlet right ventricle with subaortic defect. The configuration of endocardial swellings in the outflow portion of the heart are compatible with the general architecture of full-grown examples of the anomaly. This configuration differs considerably from normal embryonic anatomy, but is still supported by the architecture of the myoepicardial mantle. It is concluded that endocardial swellings play a secondary role in the determination of fullgrown cardiac anatomy.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00464474
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Embryology of the ventricular septum (1981)
    Springer
    Virchows Archiv 390 (1981), S. 71-79 
    Details
    ISSN: 1432-2307
    Keywords: Ventricular septum ; Cardiac embryology ; Bulbus ; Ventricle
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The formation of the ventricular septum was studied in human embryos ranging from 3.6 to 25 mm CR-length. Before septation, two distinct chambers are present which will contribute to the adult ventricles. They are called the bulbus and the ventricle. The circular constriction between these chambers is the bulboventricular fold. The anterior portion of the ventricular septum develops from this bulboventricular fold. Posteriorly, it fuses with a second septum, which is of purely ventricular origin. This is the inlet septum. Another portion of the bulboventricular fold persists as the trabecula septomarginalis. The trabecula septomarginalis divides the normal right ventricle into an inlet portion, stemming from the embryonic ventricle, and an outlet portion which derives from the bulbus.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00443898
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Development of the atrioventricular valve tension apparatus in the human heart (1998)
    Springer
    Anatomy and embryology 198 (1998), S. 317-329 
    Details
    ISSN: 1432-0568
    Keywords: Key words Congenital heart defects ; Cushions ; Extracellular matrix ; Immunohistochemistry ; Morphogenesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  Using various microscopical techniques we studied the development of the atrioventricular valves in human hearts between 5 and 19 weeks of development. Within the atrioventricular cushions two different layers could be recognized that remained present in all ages studied. The atrial layer, being present at the side of the atrioventricular orifice, was positive for laminin while the ventricular layer, that was connected to the myocardium, was positive for fibronectin and collagen III. Fate-mapping of these two layers, morphometrics, and scanning electron microscopy, supplemented with in vivo labeling of cushion tissue in chicken hearts have lead to new insights in the process of valve development. The cushions became freely movable prevalvular leaflets by delamination of ventricular myocardium underneath the cushion tissue. This myocardium gradually retracted towards annulus and papillary muscles and finally disappeared, resulting in fibrous, non-myocardial valves. The atrial layer of the cushions remained present as a jelly-like surface on the valve leaflets while the ventricular layer of the cushions became the compact fibrous tissue of the leaflets and the chords. Chordal development was first visible at 10 weeks of development when gaps were formed in the ventricular layer of the cushions on top of the papillary muscles. These gaps enlarged into the interchordal spaces while the cushion tissue in between the gaps lengthened to form the chords. We conclude that the leaflets as well as the chords of the atrioventricular valves are derived from atrioventricular cushion tissue. Myocardium is only important for loosening of the leaflets while keeping connection with the developing papillary muscles. Errors in delamination or retraction of myocardium or remodeling of cushion tissue into chords form the basis for various congenital valve anomalies.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004290050187
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Development of myocardial fiber organization in the rat heart (1996)
    Springer
    Anatomy and embryology 193 (1996), S. 559-567 
    Details
    ISSN: 1432-0568
    Keywords: Actin ; Myofibrils ; Confocal laser scanning microscopy ; Transmission electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Confocal laser-scanning microscopy of phalloidine-stained actin fibers is a relatively new tool for studying the development of myocardial fiber organization. It seems to show orientation of myocytes in rather early embryonic stages. To further evaluate the differentiation of the myocardium, this technique was compared with transmission electron microscopy in rat embryos aged between 11 and 18 days. Although the confocal images of actin filament patterns pointed to early myocyte orientation, the electron micrographs revealed that even at 17 days the ventricular myocardium was far from mature. Myofibrils never completely filled the myocytes, and lack of organization was the rule rather than the exception. The organized structure as revealed by confocal microscopy was based on cell-to-cell continuity, whereas electron microscopy showed crossing and disarray within individual myocytes. Exceptions were in the ventricular trabeculations, which showed precocious myofiber differentiation. The trabeculations probably support ventricular systole in those stages in which the free walls do not yet provide efficient contractions. The other exception was the wall of the outflow tract, which showed well-oriented myofibrils from early stages onwards. Apparently, the outflow tract has a different function in these stages. The differences found between confocal microscopy and electron microscopy suggest that some caution is indicated in the interpretation of fluorescent images of relatively low magnification.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00187927
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Anterolateral muscle bundle of the left ventricle in atrioventricular septal defect: Left ventricular outflow tract and subaortic stenosis (1991)
    Springer
    Pediatric cardiology 12 (1991), S. 83-88 
    Details
    ISSN: 1432-1971
    Keywords: Atrioventricular septal defect ; Anterolateral muscle bundle ; Subaortic stenosis ; Left ventricular outflow tract
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The anatomy of the left ventricular outflow tract (LVOT) in 77 hearts with atrioventricular septal defect (AVSD), 36 with a separate AV orifice and 41 with a common AV-orifice, were investigated. In all specimens, an anterolateral muscle bundle of the left ventricle was identified between the superior bridging leaflet and the left coronary aortic cusp. It displaced the attachment of the superior bridging leaflet, resulting in its clockwise rotation. The muscle bundle frequently bulged into the LVOT, but was never prominent enough to have caused significant subaortic stenosis. Measurement of the LVOT aortic ratio was possible in 54 hearts and ranged from 36–100%. In 23 cases (43%), there was mild to moderate subaortic narrowing with a ratio ranging from 53–88%. In six cases (11%), unequivocal subaortic stenosis was present, mainly in AVSD with separate AV orifices (five of six) and iatrogenic in one case with surgically corrected complete defect. A decreased ratio was mainly due to decreased anteroposterior width of the septum in the subaortic area, with anterior displacement of the superior bridging leaflet in cases with dense septal attachment of the superior bridging leaflet (i.e., in AVSD with separate AV orifices, type A complete defect with small ventricular septal defect, or surgically corrected complete defect). Significant subaortic stenosis was caused by hypertrophy of the ventricular septum in the subaortic area with anteroseptal twist in four cases, by anomalous chordal insertion of the superior bridging leaflet in one case, and iatrogenic in one case after surgical correction with left AV valve replacement in a type C complete defect. Other additional obstructive forces were an anomalous papillary muscle, a small left ventricle, and an aneurysm of the membranous septum.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02238408
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    The concurrence of dimensional aortic arch anomalies and abnormal left ventricular muscle bundles (1982)
    Springer
    Pediatric cardiology 2 (1982), S. 107-114 
    Details
    ISSN: 1432-1971
    Keywords: Aortic arch anomalies ; Abnormal left ventricular muscle bundles
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary This anatomical study was designed to evaluate the concept that reduced blood flow through the embryonic preductal aorta contributes to the pathogenesis of dimensional aortic arch anomalies. For that purpose the intracardiac anatomy of 151 specimens was examined, of which 22 had an interruption, five atresia, 76 tubular hypoplasia, and 48 local coarctation of the aortic arch. Associated malformations were found in 148 specimens (98%); the remaining three (2%) had isolated local coarctation. Anomalies predisposing to reduced aortic blood flow were present in 128 specimens (85%). Among the potential obstructive factors affecting early morphogenesis, three left ventricular muscular structures seem to be particularly important: (1) the anterolateral muscle bundle, (2) the posteromedial muscle, and (3) leftward deviation of the anterior part of the ventricular septum. Obstructing combinations with these types of anomaly were identified in 77 cases (51%). The embryologic aspects of these muscular structures are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02424945
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Single papillary muscle (“Parachute valve”) and double-orifice left ventricle in atrioventricular septal defect convergence of chordal attachment: Surgical anatomy and results of surgery (1990)
    Springer
    Pediatric cardiology 11 (1990), S. 29-35 
    Details
    ISSN: 1432-1971
    Keywords: Single papillary muscle ; Double orifice ; Atrioventricular septal defect
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A review of 59 anatomical specimens and of the findings in 65 surgically repaired patients with atrioventricular septal defect (AVSD), revealed four patients with a single papillary muscle and 11 with a double-orifice left ventricle. A single papillary muscle of the left ventricle occurred in 1.7% (1 of 59) of the anatomical specimens, and 6% (4 of 65) of the surgical cases. A double orifice of the left ventricle was found in 13.6% (8 of 59) of the anatomical specimens, and 7.7% (6 of 65) of the surgical cases. A single papillary muscle was only seen in cases with a complete defect. Double orifice was associated with partial, complete, or intermediate type of defect, with the highest incidence in the intermediate forms: 40% (4 of 10) of the anatomical specimens and 22% (2 of 9) of the surgical cases. In the anatomical study the specimens, with either single papillary muscle or double-orifice left ventricle, appear to be variants of the same malformation characterized by convergence of chordal insertion and underdevelopment of the left lateral leaflet. Pathology belonging to this spectrum was seen in 15% of our autopsy specimens and 14% of the surgical cases. In the surgical series good operative results were obtained with a conservative approach in cases with a favorable surgical anatomy.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02239544
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Development of the inlet portion of the right ventricle in the embryonic rat heart: The basis for tricuspid valve development (1994)
    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 239 (1994), S. 216-223 
    Details
    ISSN: 0003-276X
    Keywords: Scanning electron microscopy ; Myocardium ; Atrioventricular valves ; Embryology ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Background: Before septation the entire atrioventricular canal is connected with the ventricular inlet segment (primitive left ventricle), wheres the mature heart exhibits an exclusive connection of the right atrium to the right ventricule. The process which is responsible for this change is controversial.Methods: Graphic reconstructions of serially sectioned embryonic rat hearts as well as scanning electron micrographs of similar specimens were made.Results: The first indication of a right atrioventricular connection was seen as a groove in the atrioventricular junctional myocardium to the right of the inferior endocardial cushion. This groove expanded to form the right ventricular inlet portion. The right, inferior, and superior walls of this newly formed cavity were formed from junctional myocardium, which demarcated it from the trabeculated right ventricular portion in all developmental stages. The left wall equally developed from this junctional myocardium and formed the ventricular inlet septum. The junctional myocardium between right ventricular inlet and trabeculated portions was seen to develop into the tricuspid valve and its tension apparatus.Conclusions: The preseptation embryonic heart has no inlet portion to the right ventricle. This new cavity is created by remodelling of atrioventricular junctional myocardium. This myocardium also provides the material contribution to the tricuspid valve and its tension apparatus. Malformations of the right ventricular inlet portion and of the tricuspid valve are indissolubly linked. © 1994 Wiley-Liss, Inc.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ar.1092390212
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Development of the ventriculoarterial segment of the human embryonic heart: A morphometrics study (1993)
    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 236 (1993), S. 664-670 
    Details
    ISSN: 0003-276X
    Keywords: Stereology ; Morphometry ; Outflow tract ; Differential growth ; Shortening ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: In the literature, discussions continue on the question whether the distal portion of the cardiac outlet segment (ventriculoarterial portion, outflow tract of the embryonic heart) is subject to a shortening (absorption, retraction) during development. In 28 human embryos ranging from 4-42 mm crown-rump length, stereological estimates of volume fractions and surface densities were used to calculate the diameter and the length of the distal outlet segment and their changes during development. A significant increase was found in the wall thickness of this segment, whereas its length remained about the same. An actual shortening was not found. It is concluded that the relative change in proportions is the cause of the disagreements. It is further concluded that there is still a mechanical role for the aorticopulmonary septum in maintaining the length of the outlet segment during growth of this region. © 1993 Wiley-Liss, Inc.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ar.1092360410
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Spectrum of looping disturbances in stage 34 chicken hearts after retinoic acid treatment (1995)
    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 243 (1995), S. 101-108 
    Details
    ISSN: 0003-276X
    Keywords: Heart development ; Chick embryo ; All-trans retinoic acid ; Experimental embryology ; Double outlet right ventricle ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Background: In a recently developed chick model the teratogen retinoic acid has appeared to induce a spectrum of double outlet right ventricle, which needs further detailed evaluation. It is known that retionic acid is able to induce cardiac malformations. Although the exact mechanism is not known, an interaction with neural crest cell function is thought to exist.Methods: After treatment with 1 μg all-trans retinoic acid at Hamburger and Hamilton stage 15 and reincubation until stage 34 of development 41 chicken embryos were evaluated macroscopically and microscopically, supported by graphic reconstructions. These retinoic acid treated embryos were compared with a control group (n = 8).Results: The retinoic acid treated embryos could be divided in three groups. Group 1 (23/41) had an intact septum, group 2 (11/41) had an isolated ventricular septal defect (VSD), and group 3 (7/41) had a double outlet right ventricle (DORV). Besides, in the group with an intact septum 11 hearts showed an abnormal course of the subaortic outflow tract. In the group with DORV a straddling tricuspid orifice (7/8) and a double inlet left ventricle (1/8) could be distinguished. Considering the external contour, the hearts in the DORV group all showed a dextroposed arterial pole. Malformed pharyngeal arch arteries were found in all three groups (11/41) and with a great diversity.Conclusions: The present cardiac malformations in the chicken as a result of retinoic acid treatment are part of a continuous spectrum, varying from hearts with an intact ventricular septum and a normal course of the subaortic outflow tract to a double outlet right ventricle with a straddling tricuspid orifice or even a double inlet left ventricle. A remarkable observation in this spectrum concerns the correlation of malformations of the inflow and outflow tracts, which is explained as a cardiac looping disturbance. The disturbance of the looping process seems to lead to malalignment of septal components, although, in the chick, retinoic acid does not in general interfere with the formation of these septal components themselves. © 1995 Wiley-Liss, Inc.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ar.1092430112
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...