Three-dimensional reconstruction of a mammalian Z-band from skeletal muscle

1992 ◽  
Vol 50 (1) ◽  
pp. 542-543
Author(s):  
J. P. Schroeter ◽  
M. A. Goldstein ◽  
J. P. Bretaudiere ◽  
R. L. Sass
Keyword(s):  
Skeletal Muscle ◽  
Cross Sections ◽  
Three Dimensional ◽  
Square Lattice ◽  
Back Projection ◽  
Axial Filament ◽  
Dimensional Reconstruction ◽  
Rat Soleus Muscle ◽  
Tilt Series ◽  
Three Dimensional Models

We have completed 3-d reconstructions of several regions of the Z-band in relaxed rat soleus muscle using the method of weighted back projection on a tilt series from two different longitudinal sections. Various displays of the reconstructions were interpreted after corrections for section shrinkage and comparisons to three dimensional models. Examination of cross-sections of the reconstructed Z-bands reveal that the lattice is in the small square form. We have previously shown that this form of the Z-band lattice is predominate in relaxed skeletal muscle. The reconstructions reveal that cross-connecting Z-filaments are arranged in opposing pairs along the axial filament. Successive pairs of filaments are rotated by ninety degrees about the axial filament, thus generating the four-fold appearance seen in the projected small square lattice.

scholarly journals Three-dimensional structure of the Z band in a normal mammalian skeletal muscle.

1996 ◽  
Vol 133 (3) ◽  
pp. 571-583 ◽  
Author(s):  
J P Schroeter ◽  
J P Bretaudiere ◽  
R L Sass ◽  
M A Goldstein
Keyword(s):  
Skeletal Muscle ◽  
Cross Sections ◽  
Three Dimensional ◽  
Square Lattice ◽  
Actin Binding ◽  
Dimensional Structure ◽  
Mammalian Skeletal Muscle ◽  
Axial Filament ◽  
Three Dimensional Structure ◽  
Dimensional Reconstruction

The three-dimensional structure of the vertebrate skeletal muscle Z band reflects its function as the muscle component essential for tension transmission between successive sarcomeres. We have investigated this structure as well as that of the nearby I band in a normal, unstimulated mammalian skeletal muscle by tomographic three-dimensional reconstruction from electron micrograph tilt series of sectioned tissue. The three-dimensional Z band structure consists of interdigitating axial filaments from opposite sarcomeres connected every 18 +/- 12 nm (mean +/- SD) to one to four cross-connecting Z-filaments are observed to meet the axial filaments in a fourfold symmetric arrangement. The substantial variation in the spacing between cross-connecting Z-filament to axial filament connection points suggests that the structure of the Z band is not determined solely by the arrangement of alpha-actinin to actin-binding sites along the axial filament. The cross-connecting filaments bind to or form a "relaxed interconnecting body" halfway between the axial filaments. This filamentous body is parallel to the Z band axial filaments and is observed to play an essential role in generating the small square lattice pattern seen in electron micrographs of unstimulated muscle cross sections. This structure is absent in cross section of the Z band from muscles fixed in rigor or in tetanus, suggesting that the Z band lattice must undergo dynamic rearrangement concomitant with crossbridge binding in the A band.

A comparison of the Three-Dimensional structures of Z bands in unstimulated and rigor skeletal muscle

1995 ◽  
Vol 53 ◽  
pp. 1080-1081
Author(s):  
J.P. Schroeter ◽  
R.J. Edwards ◽  
M.A. Goldstein
Keyword(s):  
Skeletal Muscle ◽  
Electron Micrographs ◽  
Cross Sections ◽  
Structural Transition ◽  
Three Dimensional ◽  
Square Lattice ◽  
Thin Sections ◽  
Tomographic Method ◽  
Dimensional Reconstruction ◽  
Rat Soleus Muscle

Previous studies (reviewed in ref. 1) lead to the expectation that Z bands from unstimulated skeletal muscle exhibit the unactivated small square form of the Z band lattice. Rigor Z bands, on the other hand are expected to exhibit the basket-weave form of the Z band lattice associated with activation in skeletal muscle. This Z band structural transition has been investigated by three-dimensional reconstruction of Z bands and nearby I bands in unstimulated and rigor rat soleus muscle. The reconstructions were calculated using the tomographic method of weighted back-projection on a series of electron micrographs of longitudinal thin sections of muscle.Examination of Z band cross-sections of the reconstructions reveals that the unstimulated muscle does indeed exhibit the expected small square lattice form. Furthermore, Z band cross sections of the rigor reconstructions reveal the expected basket-weave lattice form. The lattice dimensions were 20 +- 1 nra for the small square lattice and 27 +- 4 nm for the basket-weave lattice, consistent with the results from electron micrographs of cross-sections.

Three-Dimensional Reconstruction reconstruction of A Z band from rigor skeletal muscle

1994 ◽  
Vol 52 ◽  
pp. 308-309
Author(s):  
J.P. Schroeter ◽  
R.J. Edwards ◽  
M. A. Goldstein
Keyword(s):  
Cross Sections ◽  
Lattice Spacing ◽  
Three Dimensional ◽  
Section Thickness ◽  
Back Projection ◽  
Dimensional Reconstruction ◽  
Rat Soleus Muscle ◽  
Projection Techniques ◽  
Tilt Series ◽  
Muscle Section

We have produced three dimensional reconstructions of several regions of the Z band and the nearby I band in rat soleus muscle in rigor. The reconstructions were calculated using weighted back-projection techniques on electron micrograph tilt series taken about two orthogonal axes. Examination of cross-sections of the reconstructed Z bands reveal that the lattice is in the basket-weave form. We have previously shown that this form of the Z band lattice predominates in the muscle in rigor. The reconstructions reveal a dense net of cross-connecting Z-filaments in the Z band, which interconnect the axial filaments in a projected four-fold array.The Z band lattice spacing was measured as 27 +− 4 nm, consistent with values seen in electron micrographs of cross sections of this muscle. The Z spacing and the form of the lattice show little distortion from that observed in cross sections, despite a beam induced change in section thickness from ∼80 to 45 nm. This suggests that, as in previous Z band reconstructions in unstimulated muscle, section shrinkage in the Z band does not occur by means of a uniform collapse throughout the section.

scholarly journals Differences in trochlear groove based on morphometric measurements of three-dimensional reconstruction models between native knees and five different femoral component designs in Chinese subjects

2020 ◽  
Author(s):  
shi chang chen ◽  
Hua Xu ◽  
Shaohua Gong
Keyword(s):  
Femoral Component ◽  
Cross Section ◽  
Cross Sections ◽  
Three Dimensional ◽  
Lateral Position ◽  
Trochlear Groove ◽  
Dimensional Reconstruction ◽  
Total Knee ◽  
Three Dimensional Models ◽  
Prosthetic Knees

Abstract Background: The p rosthetic trochlear design is important in postoperative patellofemoral kinematics and knee function. However, little research has been conducted on the differences in trochlear groove between native and prosthetic knees. We aimed to investigate the differences between Chinese native knees and prosthetic knees of five different femoral component designs using three-dimensional computerized quantification Of the entire trochlear length. Methods: Virtual total knee arthroplasty was performed using three-dimensional models of 42 healthy Chinese knees matched to the femoral components of five different prosthe tic systems by mechanical alignment . T he deepest points of the trochlear groove were marked in multiple cross sections for both the native and prosthetic knees . Taking the lower extremity mechanical axis as reference line, the differences in the mediolateral location of the trochlear groove were analyzed between the native and prosthetic knees. Results: From the proximal to the distal end, the native trochlear groove started from 0° cross section and extended laterally and then medially , with its turning point located at 69° cross section . T he prosthetic trochlear groove showed a similar medial orientation and extended more proximally, but varied in mediolateral location and the length extending to the intercondylar notch . Compared with the proximal portion of the native trochlear groove , the prosthetic knee s extended along a paradoxical orientation and started from a more proximal and lateral position to 3.2 mm in the 0° cross section , with maximal discrepancy. Distally, the prosthetic trochlear groove s were located significantly medial to 2.4 mm in the 69° cross section , with maximal discrepancy. Conclusion: The prosthetic trochlear design varie d among the different types and did not conform to the native knee in terms of shape, orientation, and location, which may cause soft tissue tension imbalance and abnormal patellofemoral biomechanics during knee flexion. This study may provide useful information for creating prosthetic trochlear design s that conform with the native knee anatomy to optimize patellofemoral biomechanics and reduce the risk of patellofemoral complications.

scholarly journals Differences in trochlear groove based on morphometric measurements of three-dimensional reconstruction models between native knees and five different femoral component designs in Chinese subjects

2020 ◽  
Author(s):  
Shi Chang Chen ◽  
Hua Xu ◽  
Shaohua Gong
Keyword(s):  
Femoral Component ◽  
Cross Section ◽  
Cross Sections ◽  
Three Dimensional ◽  
Lateral Position ◽  
Trochlear Groove ◽  
Dimensional Reconstruction ◽  
Total Knee ◽  
Three Dimensional Models ◽  
Prosthetic Knees

Abstract Background: The prosthetic trochlear design is important in postoperative patellofemoral kinematics and knee function. However, little research has been conducted on the differences in trochlear groove between native and prosthetic knees. We aimed to investigate the differences between Chinese native knees and prosthetic knees of five different femoral component designs using three-dimensional computerized quantification of the entire trochlear length.Methods: Virtual total knee arthroplasty was performed using three-dimensional models of 42 healthy Chinese knees matched to the femoral components of five different prosthetic systems by mechanical alignment. The deepest points of the trochlear groove were marked in multiple cross sections for both the native and prosthetic knees. Taking the lower extremity mechanical axis as reference line, the differences in the mediolateral location of the trochlear groove were analyzed between the native and prosthetic knees.Results: From the proximal to the distal end, the native trochlear groove started from 0° cross section and extended laterally and then medially, with its turning point located at 69° cross section. The prosthetic trochlear groove showed a similar medial orientation and extended more proximally, but varied in mediolateral location and the length extending to the intercondylar notch. Compared with the proximal portion of the native trochlear groove, the prosthetic knees extended along a paradoxical orientation and started from a more proximal and lateral position to 3.2 mm in the 0° cross section, with maximal discrepancy. Distally, the prosthetic trochlear grooves were located significantly medial to 2.4 mm in the 69° cross section, with maximal discrepancy.Conclusion: The prosthetic trochlear design varied among the different types and did not conform to the native knee in terms of shape, orientation, and location, which may cause soft tissue tension imbalance and abnormal patellofemoral biomechanics during knee flexion. This study may provide useful information for creating prosthetic trochlear designs that conform with the native knee anatomy to optimize patellofemoral biomechanics and reduce the risk of patellofemoral complications.

Three-Dimensional Reconstruction of Two Forms of the Chaperonin GRO EL

1990 ◽  
Vol 48 (1) ◽  
pp. 258-259
Author(s):  
J.L. Carrascosa ◽  
G. Abella ◽  
S. Marco ◽  
M. Muyal ◽  
J.M. Carazo
Keyword(s):  
Three Dimensional ◽  
The Other ◽  
Two Dimensional ◽  
Series Method ◽  
Three Dimensional Reconstruction ◽  
Structural Components ◽  
E Coli ◽  
Dimensional Reconstruction ◽  
Morphogenetic Factors ◽  
Tilt Series

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.

Three-dimensional tomography using a soft X-ray holographic microscope and CCD camera

1998 ◽  
Vol 5 (3) ◽  
pp. 1088-1089 ◽  
Author(s):  
Norio Watanabe ◽  
Sadao Aoki
Keyword(s):  
Tungsten Wire ◽  
Three Dimensional ◽  
Numerical Aperture ◽  
Ccd Camera ◽  
Depth Resolution ◽  
Projection Data ◽  
Back Projection ◽  
X Ray ◽  
Dimensional Reconstruction ◽  
Transverse Resolution

The depth resolution of a soft X-ray hologram is much worse than its transverse resolution because a single soft X-ray hologram has a small numerical aperture. To obtain a three-dimensional image, in-line holograms of a specimen were recorded from various directions and reconstructed to obtain two-dimensional projection data. Then, a three-dimensional reconstruction was performed by back-projection of these reconstructed holograms. Three-dimensional images of a tungsten wire of diameter 10 µm and a fossil of a diatom were obtained.

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