In vitro development of isolated ectoderm from axolotl gastrulae

Development ◽  
1984 ◽  
Vol 80 (1) ◽  
pp. 321-330
Author(s):  
Jonathan M. W. Slack
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Light Microscopy ◽  
Outer Layer ◽  
Microscope Examination ◽  
Animal Pole ◽  
In Vitro Development ◽  
Electron Microscope Examination ◽  
Vitro Development

The development of ectoderm isolated from the animal pole of axolotl gastrulae is monitored by light microscopy, electron microscopy and analysis of newly synthesized proteins, glycoproteins and glycolipids. When control embryos are undergoing neurulation it is shown that the explants autonomously begin to express epidermal markers and do not express mesodermal markers. However the results suggest that not all the cells become epidermal and electron microscope examination shows that only the outer layer does so, the inner cells remaining undifferentiated.

Selective Sampling and Orientation of Non-Homogeneous Tissues

1968 ◽  
Vol 26 ◽  
pp. 98-99
Author(s):  
C. C. Clawson ◽  
L. W. Anderson ◽  
R. A. Good
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Light Microscopy ◽  
Random Sampling ◽  
New Method ◽  
Microscope Examination ◽  
Small Areas ◽  
Selective Sampling ◽  
Large Numbers ◽  
Specific Orientation

Investigations which require electron microscope examination of a few specific areas of non-homogeneous tissues make random sampling of small blocks an inefficient and unrewarding procedure. Therefore, several investigators have devised methods which allow obtaining sample blocks for electron microscopy from region of tissue previously identified by light microscopy of present here techniques which make possible: 1) sampling tissue for electron microscopy from selected areas previously identified by light microscopy of relatively large pieces of tissue; 2) dehydration and embedding large numbers of individually identified blocks while keeping each one separate; 3) a new method of maintaining specific orientation of blocks during embedding; 4) special light microscopic staining or fluorescent procedures and electron microscopy on immediately adjacent small areas of tissue.

In vitro development of inner cell masses isolated from t0/t0 and tw5/tw5 mouse embryos

Development ◽  
1980 ◽  
Vol 60 (1) ◽  
pp. 419-428
Author(s):  
Brigid Hogan ◽  
Martha Spiegelman ◽  
Dorothea Bennett
Keyword(s):  
Outer Layer ◽  
Inner Core ◽  
Mouse Embryos ◽  
Advanced Stage ◽  
In Vitro Development ◽  
Vitro Development

Inner cell masses (ICMs) isolated immunosurgically from mouse blastocysts segregating the homozygous lethal mutants t0/t0 and tw5/tw5 were cultured in vitro. Presumed t0/t0 ICMs fail to grow after three days in culture (equivalent gestational day 7·5) when they consist of an outer layer of endoderm cells surrounding about 30 epiblast cells. Presumed homozygous tw5/tw5 ICMs develop to a more advanced stage in culture and on the seventh day (equivalent gestational day 11·5) consist of an inner core of disorganized ectoderm cells with a small proamniotic cavity, surrounded by multiple layers of endoderm cells.

Search for Voids in a Reactor Calandria Sample by Means of Positron Annihilation and Electron Microscopy

1974 ◽  
Vol 52 (3) ◽  
pp. 278-280 ◽  
Author(s):  
S. M. Kim ◽  
W. J. L. Buyers ◽  
P. Martel ◽  
G. J. C. Carpenter
Keyword(s):  
Electron Microscopy ◽  
Angular Distribution ◽  
Electron Microscope ◽  
Positron Annihilation ◽  
Neutron Irradiation ◽  
Cold Working ◽  
Annealed Sample ◽  
Microscope Examination ◽  
Density Of Dislocations ◽  
Electron Microscope Examination

We have measured the positron annihilation angular distribution in 1S Al subjected to neutron irradiation while part of the NRX reactor calandria, in annealed IS Al, and in heavily deformed 1S Al, which simulates the cold working of the calandria sample before irradiation. The FWHM in the calandria and deformed samples were found to be similar and 11% narrower than that in the annealed sample, indicating that the dominant defects in the calandria are dislocations rather than voids. Electron microscope examination of the above samples also indicated a high density of dislocations and no significant void population in the neutron irradiated calandria.

ELECTRON MICROSCOPY OF THE IN VITRO DEVELOPMENT OF MAMMALIAN MOTOR END PLATES

1971 ◽  
Vol 183 (1 Myasthenia Gr) ◽  
pp. 33-45 ◽  
Author(s):  
G. D. Pappas ◽  
E. R. Peterson ◽  
E. B. Masurovsky ◽  
S. M. Crain
Keyword(s):  
Electron Microscopy ◽  
In Vitro Development ◽  
Motor End Plates ◽  
Vitro Development

scholarly journals LOCALIZATION OF STRUCTURAL POLYMERS IN THE CELL WALL OF NEUROSPORA CRASSA

1967 ◽  
Vol 35 (2) ◽  
pp. 295-302 ◽  
Author(s):  
P. R. Mahadevan ◽  
E. L. Tatum
Keyword(s):  
Electron Microscopy ◽  
Cell Wall ◽  
Electron Microscope ◽  
Neurospora Crassa ◽  
Outer Layer ◽  
Light Microscope ◽  
Structural Integrity ◽  
Selective Removal ◽  
Microscope Examination ◽  
Structural Polymers

The distribution and localization of structural polymers in the cell wall of Neurospora crassa has been studied by selective removal and light and electron microscope examination. Observations with the light microscope indicated that each polymer by itself can provide structural integrity to the cell wall. Examination by electron microscopy showed that the cell wall consists of an outer layer of thick fibrils, identified chemically as a glucan-peptide-galactosamine complex, and an inner layer made up of ß-1,3 glucan and thin fibrils of chitin.

Characterization of submicrometer fluid Inclusions in minerals by Analytical/Transmission Electron Microscopy and electron diffraction

1990 ◽  
Vol 48 (4) ◽  
pp. 424-424
Author(s):  
George Guthrie ◽  
David Veblen
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Microscope ◽  
Electron Diffraction ◽  
Light Microscopy ◽  
Fluid Inclusions ◽  
Energy Dispersive Spectrometer ◽  
Analytical Transmission Electron Microscopy ◽  
Transmission Electron

The nature of a geologic fluid can often be inferred from fluid-filled cavities (generally <100 μm in size) that are trapped during the growth of a mineral. A variety of techniques enables the fluids and daughter crystals (any solid precipitated from the trapped fluid) to be identified from cavities greater than a few micrometers. Many minerals, however, contain fluid inclusions smaller than a micrometer. Though inclusions this small are difficult or impossible to study by conventional techniques, they are ideally suited for study by analytical/ transmission electron microscopy (A/TEM) and electron diffraction. We have used this technique to study fluid inclusions and daughter crystals in diamond and feldspar.Inclusion-rich samples of diamond and feldspar were ion-thinned to electron transparency and examined with a Philips 420T electron microscope (120 keV) equipped with an EDAX beryllium-windowed energy dispersive spectrometer. Thin edges of the sample were perforated in areas that appeared in light microscopy to be populated densely with inclusions. In a few cases, the perforations were bound polygonal sides to which crystals (structurally and compositionally different from the host mineral) were attached (Figure 1).

Development of an in vitro Model for the Study of the Response of Equine Tendon Fibroblasts to Injury and Medication

1997 ◽  
Vol 10 (01) ◽  
pp. 6-11 ◽  
Author(s):  
R. F. Rosenbusch ◽  
L. C. Booth ◽  
L. A. Dahlgren
Keyword(s):  
Electron Microscopy ◽  
Extracellular Matrix ◽  
Light Microscopy ◽  
Light And Electron Microscopy ◽  
Tendon Healing ◽  
Matrix Proteins ◽  
Isolated Cells ◽  
Superficial Digital Flexor Tendon ◽  
Vitro Model

SummaryEquine tendon fibroblasts were isolated from explants of superficial digital flexor tendon, subcultured and maintained in monolayers. The cells were characterized by light microscopy, electron microscopy and radiolabel studies for proteoglycan production. Two predominant cell morphologies were identified. The cells dedifferentiated toward a more spindle shape with repeated subcultures. Equine tendon fibroblasts were successfully cryopreserved and subsequently subcultured. The ability to produce proteoglycan was preserved.The isolated cells were identified as fibroblasts, based on their characteristic shape by light microscopy and ultrastructure and the active production of extracellular matrix proteins. Abundant rough endoplasmic reticulum and the production of extracellular matrix products demonstrated active protein production and export. Proteoglycans were measurable via liquid scintillation counting in both the cell-associated fraction and free in the supernatant. This model is currently being utilized to study the effects of polysulfated glycosaminoglycan on tendon healing. Future uses include studying the effects of other pharmaceuticals, such as hyaluronic acid, on tendon healing.A model was developed for in vitro investigations into tendon healing. Fibroblasts were isolated from equine superficial digital flexor tendons and maintained in monolayer culture. The tenocytes were characterized via light and electron microscopy. Proteoglycan production was measured, using radio-label techniques. The fibroblasts were cryopreserved and subsequently subcultured. The cells maintained their capacity for proteoglycan production, following repeated subculturing and cryopreservation.

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