scholarly journals Three‐dimensional reconstruction of defects in congenital diaphragmatic hernia: a fetal MRI study

2019 ◽  
Vol 53 (6) ◽  
pp. 816-826 ◽  
Author(s):  
F. Prayer ◽  
M. Metzelder ◽  
W. Krois ◽  
P. C. Brugger ◽  
G. M. Gruber ◽  
...  
2021 ◽  
Vol 5 ◽  
pp. 56-60
Author(s):  
O.Ya. Slobodyanik ◽  
V.V. Bila ◽  
V.M. Tyshkevych ◽  
M.V. Protsyk ◽  
V.S. Shevchenko

Congenital diaphragmatic hernia is a rare congenital anomaly of diaphragmatic development with a frequency of approximately 1 in 2,500 live births. The structural defect is accompanied by pathophysiological disorders, in particular, pulmonary hypertension, as well as pulmonary hypoplasia of various degrees, which actually determine the severity of the defect. In 84% of cases, the diaphragmatic hernia is located on the left dome of the diaphragm, possible right-sided and left-sided localization of the malformation, which is 14 and 2%, respectively.The defect can be either isolated or combined with other congenital anomalies, such as congenital heart disease or chromosomal abnormalities. Violation of the closure of the diaphragm during the 4-10th week of fetal development leads to the formation of the diaphragmatic grid. During the same period (5th week of gestation) is the formation of lungs and bronchs. Three-dimensional ultrasound diagnosis allows to detect prenatal defect in almost 60% of fetuses. Fetal MRI is a method of choosing the anatomical assessment of the lungs, determining their volume allows you to more accurately predict the development of complications and the required amount of care after birth. The article is devoted to the description of clinical observation of ENT with a description of the features of perinatal diagnosis and organization of postnatal care. The defect was diagnosed at 31 weeks, vaginal delivery occurred during full-term pregnancy. The complex of resuscitation measures, preoperative preparation, the course of the postoperative period is described. Timely prenatal diagnosis of EDC and its anatomical variant makes it possible to correctly develop the patient’s route, starting with the tactics of pregnancy, method of delivery, as well as to predict the algorithm of staff actions at birth and subsequent treatment of the newborn.


Author(s):  
J. Frank ◽  
B. F. McEwen ◽  
M. Radermacher ◽  
C. L. Rieder

The tomographic reconstruction from multiple projections of cellular components, within a thick section, offers a way of visualizing and quantifying their three-dimensional (3D) structure. However, asymmetric objects require as many views from the widest tilt range as possible; otherwise the reconstruction may be uninterpretable. Even if not for geometric obstructions, the increasing pathway of electrons, as the tilt angle is increased, poses the ultimate upper limitation to the projection range. With the maximum tilt angle being fixed, the only way to improve the faithfulness of the reconstruction is by changing the mode of the tilting from single-axis to conical; a point within the object projected with a tilt angle of 60° and a full 360° azimuthal range is then reconstructed as a slightly elliptic (axis ratio 1.2 : 1) sphere.


Author(s):  
Nicolas Boisset ◽  
Jean-Christophe Taveau ◽  
Jean Lamy ◽  
Terence Wagenknecht ◽  
Michael Radermacher ◽  
...  

Hemocyanin, the respiratory pigment of the scorpion Androctonus australis is composed of 24 kidney shaped subunits. A model of architecture supported by many indirect arguments has been deduced from electron microscopy (EM) and immuno-EM. To ascertain, the disposition of the subunits within the oligomer, the 24mer was submitted to three-dimensional reconstruction by the method of single-exposure random-conical tilt series.A sample of native hemocyanin, prepared with the double layer negative staining technique, was observed by transmisson electron microscopy under low-dose conditions. Six 3D-reconstructions were carried out indenpendently from top, side and 45°views. The results are composed of solid-body surface representations, and slices extracted from the reconstruction volume.The main two characters of the molecule previously reported by Van Heel and Frank, were constantly found in the solid-body surface representations. These features are the presence of two different faces called flip and flop and a rocking of the molecule around an axis passing through diagonnally opposed hexamers. Furthermore, in the solid-body surface of the top view reconstruction, the positions and orientations of the bridges connecting the half molecules were found in excellent agreement with those predicted by the model.


Author(s):  
J.L. Carrascosa ◽  
G. Abella ◽  
S. Marco ◽  
M. Muyal ◽  
J.M. Carazo

Chaperonins are a class of proteins characterized by their role as morphogenetic factors. They trantsiently interact with the structural components of certain biological aggregates (viruses, enzymes etc), promoting their correct folding, assembly and, eventually transport. The groEL factor from E. coli is a conspicuous member of the chaperonins, as it promotes the assembly and morphogenesis of bacterial oligomers and/viral structures.We have studied groEL-like factors from two different bacteria:E. coli and B.subtilis. These factors share common morphological features , showing two different views: one is 6-fold, while the other shows 7 morphological units. There is also a correlation between the presence of a dominant 6-fold view and the fact of both bacteria been grown at low temperature (32°C), while the 7-fold is the main view at higher temperatures (42°C). As the two-dimensional projections of groEL were difficult to interprete, we studied their three-dimensional reconstruction by the random conical tilt series method from negatively stained particles.


2006 ◽  
Vol 175 (4S) ◽  
pp. 82-82
Author(s):  
Gustavo Ayala ◽  
Rile Li ◽  
Hong Oai ◽  
Mohammad Sayeeddudin ◽  
Timothy C. Thompson ◽  
...  

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