Origin of the irideal striated muscle in birds

Development ◽  
1985 ◽  
Vol 88 (1) ◽  
pp. 1-13
Author(s):  
Kensuke E. Nakano ◽  
Harukazu Nakamura
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Stromal Cells ◽  
Striated Muscle ◽  
Muscle Cells ◽  
Chick Embryos ◽  
Dorsal Part ◽  
Nuclear Marker ◽  
Transmission Electron ◽  
The Right

The aim of the present study was to elucidate the origin of the striated muscle cells in the avian iris. For this purpose we adopted interspecific transplantation between quail and chick embryos because quail cells can be used as biological markers in this system. We transplanted isotopically and isochronically (6- to 7-somite stage) a fragment of a dorsal part of the quail neural anlage into a chick embryo at the level corresponding to the posterior prosencephalon and the mesencephalon on the right-hand side. In the chimaeric embryo, the iris epithelium comprised host chick cells, while most of the stromal cells of the iris on the operated side possessed the quail nuclear marker. At 19 days after the operation, the striated muscle cells had differentiated in the chimaeric embryo. These cells, as well as connective tissue cells and the Schwann cells of the iris of the chimaera, were shown to possess typical quail nuclei by light and transmission electron microscopy. From these findings, we conclude that the striated muscle cells originate from the neural crest.

Cleavage in the chick embryo

Development ◽  
1978 ◽  
Vol 43 (1) ◽  
pp. 55-69
Author(s):  
Ruth Bellairs ◽  
F. W. Lorenz ◽  
Tania Dunlap
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Chick Embryo ◽  
Cell Membrane ◽  
Cortical Region ◽  
Chick Embryos ◽  
Membrane Formation ◽  
Transmission Electron

Chick embryos ranging from the stage of first cleavage to that of about 700 cells were removed from the oviduct and examined by transmission electron microscopy. Beneath the cell membrane is a yolk-free cortical region containing microfilaments. Beneath this lies cytoplasm which contains yolk spheres which are graded in size, the dorsal ones being smaller than the ventral ones. The subgerminal periblast possesses a greater proportion of yolk to cytoplasm than do the cells proper, but it merges with the cytoplasm at the incomplete borders of the ‘open’ cells. Specialized accumulations of membranes lie in the marginal periblast, and it is suggested that they play a role in cell membrane formation.

scholarly journals Developmental reorganization of the skeletal framework and its surface lamina in fusing muscle cells.

1981 ◽  
Vol 91 (1) ◽  
pp. 103-112 ◽  
Author(s):  
A B Fulton ◽  
J Prives ◽  
S R Farmer ◽  
S Penman
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Concanavalin A ◽  
Muscle Cells ◽  
Surface Proteins ◽  
Transmission Electron ◽  
Continuous Surface ◽  
Internal Networks ◽  
Structural Networks ◽  
Whole Mounts

The skeletal framework of cells, composed of internal structural fibers, microtrabeculae, and the surface lamina, is revealed with great clarity after extraction with detergent. When muscle cells fuse to form a multinucleated myotube, their skeletal framework reorganizes extensively. When myoblasts prepare to fuse, the previously continuous surface lamina develops numerous lacunae unique to this stage. The retention of iodinated surface proteins suggests that the lacunae are not formed by the extraction of lamina proteins. The lacunae appear to correspond to extensive patches that do not bind concanavalin A and are probably regions of lipid bilayer devoid of glycoproteins. The lacunae appear to be related to fusion and disappear rapidly after the multinucleated myotube is formed. When muscle cells fuse, their internal structural networks must interconnect to form the framework of the myotube. Transmission electron microscopy of skeletal framework whole mounts shows that proliferating myoblasts have well developed and highly interconnected internal networks. Immediately before fusion, these networks are extensively reorganized and destabilized. After fusion, a stable, extensively cross-linked internal structure is reformed, but with a morphology characteristic of the myotube. Muscle cells therefore undergo extensive reorganization both on the surface and internally at the time of fusion.

scholarly journals Telocytes and Lymphatics of the Human Colon

Life ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1001
Author(s):  
Mihai Zurzu ◽  
Mihnea Ioan Nicolescu ◽  
Laurențiu Mogoantă ◽  
Stelian Pantea ◽  
Mugurel Constantin Rusu
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Stromal Cells ◽  
Immunohistochemical Study ◽  
Human Colon ◽  
Morphological Type ◽  
Double Labelling ◽  
Perivascular Cells ◽  
Transmission Electron ◽  
Myenteric Ganglia

Background: Telocytes (TCs) are a peculiar morphological type of stromal cells. They project long and moniliform telopodes, visible on various bidimensional sections. Originally regarded as “interstitial Cajal-like cells”, gastrointestinal TCs were CD34+. Further double-labelling studies found that colon TCs are negative for the expressions of the PDGFR-α and α-SMA. However, the TCs in colon were not distinguished specifically from endothelial cells (ECs), vascular or lymphatic. A combinational approach is important for accurate TC identification. Hence, we designed an immunohistochemical study of human colon to check whether ECs and CD34+ TCs express different markers. Methods: Immunohistochemistry was performed on archived paraffin-embedded samples of human colon (nine cases) for the following markers: CD31, CD34, CD117/c-kit and D2-40 (podoplanin). Results: A distinctive population of CD34+ TCs was found coating the myenteric ganglia. However, also perivascular cells and vascular ECs were CD34+. c-kit expression was equally found in interstitial Cajal cells (ICCs) and perivascular cells. The CD34 TCs did not express c-kit. As they were equally CD31- and D2-40- they were assessed as different from ECs. Conclusions: Testing specific markers of ECs, vascular and lymphatic, in the same tissues in which CD34+ TCs are found, is much more relevant than to identify TCs by transmission electron microscopy alone.

scholarly journals Stoichiometry and Interdiffusion in PZT Thin Films Studied by Transmission Electron Microscopy

1999 ◽  
Vol 596 ◽  
Author(s):  
L. Sagalowicz ◽  
P. Muralt ◽  
S. Hiboux ◽  
T. Maeder ◽  
K. Brooks ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Silicon Oxide ◽  
Sol Gel ◽  
Pyrochlore Phase ◽  
Second Phase ◽  
Adhesion Layer ◽  
Transmission Electron ◽  
The Right ◽  
Electrode Systems

AbstractElectrode stability, interdiffusion, phase purity and deviation from stoichiometry at the PZT-electrode interface are key issues in PZT thin film integration. This article highlights the use of transmission electron imaging combined with energy dispersive spectroscopy (EDS) for the investigation of these phenomena. The accuracy of the EDS analysis is discussed. It will be shown that using a standard PZT sample and controlled conditions, reliable analysis can be performed.Diffusion mechanisms have been studied for Pt based electrode systems and RuO2-based electrode systems developed for direct integration onto silicon. The materials studied were composed of stacks of silicon-silicon oxide, an adhesion layer (Ti, Ta or TiOx), an electrode (Pt or RuG2) and PZT (45/55). The PZT was deposited by sol gel using the same parameters to allow for comparison of the different electrodes. Four different electrode / adhesion layer materials were compared (Pt/Ti, Pt/TiOx, Pt/Ta and RuO2 / TiO2). In the case of Pt, lead and oxygen diffusion through the electrode is observed. While the initial Ta layer transforms into a homogeneous pyrochlore phase, the Ti adhesion layer is heavily deformed. In the case of TiOx the lead is mainly incorporated at the interfaces with Pt and with SiO2. No lead diffusion to the adhesion layer is observed for the RuO2 electrode. In-situ sputtering and sol-gel deposition of PZT are also compared. The sol-gel films are close to the right stoichiometry for the perovskite while the sputtered films contained an excess of lead. No sign of second phase is found by X-ray diffraction (XRD), by EDS and by high resolution transmission electron microscopy (HRTEM) which suggests that the excess lead is accommodated in the perovskite lattice.

scholarly journals Good Preservation of Stromal Cells and No Apoptosis in Human Ovarian Tissue after Vitrification

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Raffaella Fabbri ◽  
Rossella Vicenti ◽  
Maria Macciocca ◽  
Gianandrea Pasquinelli ◽  
Roberto Paradisi ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Light Microscopy ◽  
Stromal Cells ◽  
Ovarian Tissue ◽  
Tunel Assay ◽  
Ovarian Tissue Cryopreservation ◽  
Human Ovarian Tissue ◽  
Transmission Electron ◽  
Oocyte Cytoplasm

The aim of this study was to develop a vitrification procedure for human ovarian tissue cryopreservation in order to better preserve the ovarian tissue. Large size samples of ovarian tissue retrieved from 15 female-to-male transgender subjects (18–38 years) were vitrified using two solutions (containing propylene glycol, ethylene glycol, and sucrose at different concentrations) in an open system. Light microscopy, transmission electron microscopy, and TUNEL assay were applied to evaluate the efficiency of the vitrification protocol. After vitrification/warming, light microscopy showed oocyte nucleus with slightly thickened chromatin and irregular shape, while granulosa and stromal cells appeared well preserved. Transmission electron microscopy showed oocytes with slightly irregular nuclear shape and finely dispersed chromatin. Clear vacuoles and alterations in cellular organelles were seen in the oocyte cytoplasm. Stromal cells had a moderately dispersed chromatin and homogeneous cytoplasm with slight vacuolization. TUNEL assay revealed the lack of apoptosis induction by vitrification in all ovarian cell types. In conclusion after vitrification/warming the stromal compartment maintained morphological and ultrastructural features similar to fresh tissue, while the oocyte cytoplasm was slightly damaged. Although these data are encouraging, further studies are necessary and essential to optimize vitrification procedure.

Characterisation and cryopreservation of the ovarian preantral follicle population from Spix’s yellow-toothed cavies (Galea spixii Wagler, 1831)

2017 ◽  
Vol 29 (3) ◽  
pp. 594 ◽  
Author(s):  
Érica C. G. Praxedes ◽  
Gabriela L. Lima ◽  
Andréia M. Silva ◽  
Carlos A. C. Apolinário ◽  
José A. B. Bezerra ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Light Microscopy ◽  
Population Analysis ◽  
Ovarian Tissue ◽  
Morphological Aspect ◽  
Preantral Follicle ◽  
Transmission Electron ◽  
The Mean ◽  
The Right

The aim of the present study was to characterise the ovarian preantral follicle (PF) population and to establish a solid surface vitrification (SSV) process using dimethyl sulfoxide (DMSO) as a cryoprotectant for preservation of ovarian tissue from yellow-toothed cavies (Galea spixii). Ovaries were fixed for PF population analysis or were subjected to the SSV process. The mean (± s.e.m.) PF population per ovarian pair was estimated to be 416.0 ± 342.8. There were 140.0 ± 56.0 (63.4%) and 125.0 ± 58.0 (64.0%) primary follicles on the right and left ovaries, respectively. The proportion of this follicle category was significantly greater than that of other follicle categories (P < 0.05). The diameter of follicles (123.7 ± 18.3 µm), oocytes (50.1 ± 5.0 µm) and nuclei (14.27 ± 2.01 µm) was larger for secondary ones when compared with other PFs categories. Most PFs were morphologically normal (94.6%), with light microscopy identifying only a few atretic follicles (5.4%). After SSV, there was a reduction in the proportion of morphologically normal PFs compared with the non-vitrified group (69.5% vs 91.2%, respectively). Transmission electron microscopy revealed preservation of oocytes and granulosa cell membranes and the morphological aspect of follicles; the primary change observed in some vitrified PFs was the presence of vacuoles in the oocytes and granulosa cells cytoplasm and turgid mitochondria. In conclusion, the present study provides an estimative and characterization for the PF population in ovaries of G. spixii. Moreover, we report its PFs cryopreservation using an SSV process.

Techniques for Transmission Electron Microscopy of Fiber-Matrix Interfaces in Aluminum Alloy-Boron Composites by Ion Erosio

1971 ◽  
Vol 29 ◽  
pp. 204-205
Author(s):  
G. G. Shaw
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Aluminum Alloy ◽  
Electron Beam ◽  
Pure Aluminum ◽  
Ion Milling ◽  
Transmission Electron ◽  
Fiber Matrix ◽  
Ion Erosion ◽  
Row Of Fibers

The morphology and composition of the fiber-matrix interface can best be studied by transmission electron microscopy and electron diffraction. For some composites satisfactory samples can be prepared by electropolishing. For others such as aluminum alloy-boron composites ion erosion is necessary.When one wishes to examine a specimen with the electron beam perpendicular to the fiber, preparation is as follows: A 1/8 in. disk is cut from the sample with a cylindrical tool by spark machining. Thin slices, 5 mils thick, containing one row of fibers, are then, spark-machined from the disk. After spark machining, the slice is carefully polished with diamond paste until the row of fibers is exposed on each side, as shown in Figure 1.In the case where examination is desired with the electron beam parallel to the fiber, preparation is as follows: Experimental composites are usually 50 mils or less in thickness so an auxiliary holder is necessary during ion milling and for easy transfer to the electron microscope. This holder is pure aluminum sheet, 3 mils thick.

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