scholarly journals Morphological Changes in the Skin and Wool Fibres of Merino Sheep Infused with Mouse Epidermal Growth Factor

1983 ◽  
Vol 36 (4) ◽  
pp. 419 ◽  
Author(s):  
DE Hollis ◽  
RE Chapman ◽  
BA Panaretto ◽  
GPM Moore
Keyword(s):  
Electron Microscope ◽  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Scanning Electron Microscope ◽  
Intravenous Infusion ◽  
Morphological Changes ◽  
Merino Sheep ◽  
Epidermal Growth ◽  
Skin Samples ◽  
Scanning Electron

Intravenous infusion of 4�5-4�7 mg of mouse epidermal growth factor (mEGF) into nine castrated male Merino sheep for 26 h resulted in complete casting of the fleeces 6-8 days later. The morphological changes which occurred in the skin were studied in skin samples taken before infusion and at intervals between 1 hand 42 days after the infusion had begun. Wool fibres from the shed fleeces were examined with the scanning electron microscope.

scholarly journals Detection of Epidermal Growth Factor Receptor Dimers on Wet and Intact Eukaryotic Cells in an Environmental Scanning Electron Microscope

2013 ◽  
Vol 19 (S2) ◽  
pp. 138-139 ◽  
Author(s):  
D. Peckys ◽  
U. Werner ◽  
N. de Jonge
Keyword(s):  
Epidermal Growth Factor Receptor ◽  
Electron Microscope ◽  
Growth Factor ◽  
Scanning Electron Microscope ◽  
Growth Factor Receptor ◽  
Eukaryotic Cells ◽  
Environmental Scanning ◽  
Epidermal Growth ◽  
Receptor Dimers ◽  
Scanning Electron

Extended abstract of a paper presented at Microscopy and Microanalysis 2013 in Indianapolis, Indiana, USA, August 4 – August 8, 2013.

Effect of vinblastine and cytochalasin B on the cytoskeletal domains in 3T3 cells

1981 ◽  
Vol 48 (1) ◽  
pp. 55-73
Author(s):  
J.H. Temmink ◽  
H. Spiele
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Cytochalasin B ◽  
Morphological Changes ◽  
Ultrastructural Changes ◽  
3T3 Cells ◽  
Cytoplasmic Material ◽  
Transmission Electron ◽  
Cytoskeletal Elements ◽  
Scanning Electron

Normal 3T3 cells were exposed to vinblastine and cytochalasin B in an attempt to correlate the morphological changes of the cell surface as seen in the scanning electron microscope with ultrastructural changes of the cytoskeletal elements as seen in critical-point-dried cells in the transmission electron microscope. Special attention was given to the changes in the cytoplasmic domains distinguished in a previous paper. Cytochalasin B primarily affects the ultrastructure of the cytocortical domain by inducing the formation of condensation foci on the cytoplasmic material. Vinblastine not only induces the depolymerization of microtubules and the perinuclear concentration of intermediate filaments, but it also causes the disappearance of stress fibres from the cortical cytoplasm and the widening of the cytocortex at the expense of the endoplasmic domain. These results support the hypothesis that the differentiation in ultrastructural domains is dependent on the spreading of the cells and their adhesion to substrate.

scholarly journals Coactivation of Rac1 and Cdc42 at Lamellipodia and Membrane Ruffles Induced by Epidermal Growth Factor

2004 ◽  
Vol 15 (3) ◽  
pp. 1003-1010 ◽  
Author(s):  
Kazuo Kurokawa ◽  
Reina E. Itoh ◽  
Hisayoshi Yoshizaki ◽  
Yusuke Ohba Takeshi Nakamura ◽  
Michiyuki Matsuda
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Morphological Changes ◽  
Critical Role ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
A431 Cells ◽  
Major Function ◽  
Membrane Ruffling ◽  
Epidermal Growth

A major function of Rho-family GTPases is to regulate the organization of the actin cytoskeleton; filopodia, lamellipodia, and stress fiber are regarded as typical phenotypes of the activated Cdc42, Rac, and Rho, respectively. Using probes based on fluorescent resonance energy transfer, we report on the spatiotemporal regulation of Rac1 and Cdc42 at lamellipodia and membrane ruffles. In epidermal growth factor (EGF)-stimulated Cos1 and A431 cells, both Rac1 and Cdc42 were activated diffusely at the plasma membrane, followed by lamellipodial protrusion and membrane ruffling. Although Rac1 activity subsided rapidly, Cdc42 activity was sustained at lamellipodia. A critical role of Cdc42 in these EGF-induced morphological changes was demonstrated as follows. First, phorbol 12-myristate 13-acetate, which activated Rac1 but not Cdc42, could not induce full-grown lamellipodia in Cos1 cells. Second, a GTPase-activating protein for Cdc42, KIAA1204/CdGAP, inhibited lamellipodial protrusion and membrane ruffling without interfering with Rac1 activation. Third, expression of the Cdc42-binding domain of N-WASP inhibited the EGF-induced morphological changes. Therefore, Rac1 and Cdc42 seem to synergistically induce lamellipodia and membrane ruffles in EGF-stimulated Cos1 cells and A431 cells.

Inhibition and Reversal of Salmonella Typhimurium Attachment to Poultry Skin Using Zinc Chloride

2001 ◽  
Vol 64 (4) ◽  
pp. 456-461 ◽  
Author(s):  
RAJESH NAYAK ◽  
P. BRETT KENNEY ◽  
GARY K. BISSONNETTE
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Salmonella Typhimurium ◽  
Zinc Chloride ◽  
Cell Detachment ◽  
Attached Bacteria ◽  
Attachment Model ◽  
Control Water ◽  
Skin Samples ◽  
Scanning Electron

A skin attachment model was used to determine if ZnCl2 would reverse or inhibit Salmonella attachment to broiler skin. In the reversal experiments, skin samples, treated first with 1 ml of Salmonella Typhimurium suspension (108 CFU/ml) for 30 min, were then treated with 25 or 50 mM ZnCl2 for 5 or 15 min. Zinc chloride solutions were applied while the culture was present on the skin. In the inhibition experiments, ZnCl2 solutions were added first; treatment solutions were discarded after 5 or 15 min of application, and then the culture was added. Firmly and loosely attached Salmonella were enumerated on xylose lactose tergitol plates. A duplicate section of skin, subjected concurrently to the above treatments, was observed under a scanning electron microscope to enumerate attached bacteria directly. In the reversal experiments, 25 and 50 mM ZnCl2 reduced (P < 0.01) firmly attached cells by 77 and 89%, respectively, when compared to the control (water). Micrographs indicated that 25 and 50 mM ZnCl2 reduced (P < 0.1) Salmonella attachment by 69 and 99.9%, respectively, in the reversal experiments. In the inhibition experiments, 25 and 50 mM ZnCl2 reduced (P < 0.01) firmly attached cells by 82 and 91%, respectively. Reduction of Salmonella may be attributed, in part, to the bactericidal activity of ZnCl2 in addition to bacterial cell detachment.

The JSM-890 ultra high resolution Scanning Electron Microscope

1989 ◽  
Vol 47 ◽  
pp. 88-89
Author(s):  
M. Kersker ◽  
C. Nielsen ◽  
H. Otsuji ◽  
T. Miyokawa ◽  
S. Nakagawa
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
Scanning Electron Microscope ◽  
Morphological Changes ◽  
High Current Density ◽  
High Signal ◽  
Extensive Experience ◽  
Transmission Electron ◽  
Electron Microscopes ◽  
Scanning Electron

Historically, ultra high spatial resolution electron microscopy has belonged to the transmission electron microscope. Today, however, ultra high resolution scanning electron microscopes are beginning to challenge the transmission microscope for the highest resolution.To accomplish high resolution surface imaging, not only is high resolution required. It is also necessary that the integrity of the specimen be preserved, i.e., that morphological changes to the specimen during observation are prevented. The two major artifacts introduced during observation are contamination and beam damage, both created by the small, high current-density probes necessary for high signal generation in the scanning instrument. The JSM-890 Ultra High Resolution Scanning Microscope provides the highest resolution probe attainable in a dedicated scanning electron microscope and its design also accounts for the problematical artifacts described above.Extensive experience with scanning transmission electron microscopes lead to the design considerations of the ultra high resolution JSM- 890.

Sign in / Sign up

Export Citation Format

Share Document