scholarly journals ELECTRON PROBE ANALYSIS OF THE CALCIUM DISTRIBUTION IN CELLS OF THE EMBRYONIC CHICK CHORIOALLANTOIC MEMBRANE I. A CRITICAL EVALUATION OF TECHNIQUES

1972 ◽  
Vol 20 (6) ◽  
pp. 401-413 ◽  
Author(s):  
JAMES R. COLEMAN ◽  
A. RAYMOND TEREPKA
Keyword(s):  
Electron Probe ◽  
Critical Evaluation ◽  
Chorioallantoic Membrane ◽  
Embryonic Chick ◽  
Total Calcium ◽  
Electron Probe Analysis ◽  
X Ray ◽  
Chick Chorioallantoic Membrane ◽  
Minor Losses

The chorioallantoic membrane of the developing chick embryo is an epithelium that actively transports calcium. The methodology utilized to prepare this soft tissue for calcium localization with the electron probe x-ray microanalyzer is presented in detail. The preparative procedures are evaluated according to general histochemical principles and in relationship specifically to electron probe investigations. It is shown that the method employed in these studies preserves the normal fine structure of the tissue, prevents selective loss of calcium, permits only minor losses of total calcium and appears to maintain the distribution of calcium that existed in vivo. Examples are presented of artifacts that can be induced during tissue sectioning and mounting procedures. Problems of defining electron probe resolution in biologic specimens are discussed, and the critical importance of evaluating x-ray images in association with simultaneously generated sample current images is emphasized.

scholarly journals ELECTRON PROBE ANALYSIS OF THE CALCIUM DISTRIBUTION IN CELLS OF THE EMBRYONIC CHICK CHORIOALLANTOIC MEMBRANE II. DEMONSTRATION OF INTRACELLULAR LOCATION DURING ACTIVE TRANSCELLULAR TRANSPORT

1972 ◽  
Vol 20 (6) ◽  
pp. 414-424 ◽  
Author(s):  
JAMES R. COLEMAN ◽  
A. RAYMOND TEREPKA
Keyword(s):  
Electron Probe ◽  
Chorioallantoic Membrane ◽  
Embryonic Chick ◽  
Ion Regulation ◽  
Electron Probe Analysis ◽  
Intracellular Location ◽  
Transcellular Transport ◽  
Calcium Sequestration ◽  
Chick Chorioallantoic Membrane ◽  
Probe Analysis

Electron probe analysis of the embryonic chick chorioallantoic membrane reveals that calcium is located at discrete sites in the ectodermal cell layer of the membrane. The calcium loci are found at characteristic sites within distinctive "capillary-covering" cells. Evidence is presented that the calcium identified by electron probe analysis is that pool of calcium undergoing active transcellular transport. Mitochondria and/or endoplasmic reticulum do not appear to be responsible for the observed calcium sequestration. It is suggested that the calcium might be contained within endocytotic vesicles, and a hypothesis is advanced which could reconcile endocytotic transcellular transport by specialized cells with previously proposed models for intracellular calcium ion regulation.

The chick embryo chorioallantoic membrane model: a research approach for ex vivo and in vivo experiments

2021 ◽  
Vol 28 ◽  
Author(s):  
Ana Isabel Fraguas-Sánchez ◽  
Cristina Martín-Sabroso ◽  
Ana Isabel Torres-Suárez
Keyword(s):  
Animal Models ◽  
Chorioallantoic Membrane ◽  
New Drugs ◽  
Biological Research ◽  
Research Areas ◽  
Chick Chorioallantoic Membrane ◽  
Biodistribution Studies ◽  
Toxicological Studies ◽  
Cam Model

Background: The chick chorioallantoic membrane (CAM) model has attracted a great deal of interest in pharmaceutical and biological research as an alternative or complementary in vivo assay to animal models. Traditionally, CAM assay has been widely used to perform some toxicological studies, specifically to evaluate the skin, ocular and embryo toxicity of new drugs and formulations, and perform angiogenesis studies. Due to the possibility to generate the tumors onto the CAM, this model has also become an excellent strategy to evaluate the metastatic potential of different tumours and test the efficacy of novel anticancer therapies in vivo. Moreover, in the recent years, its use has considerably grown in other research areas, including the evaluation of new anti-infective agents, the development of biodistribution studies and tissue engineering research. Objectives: This manuscript provides a critical overview of the use of CAM model in pharmaceutical and biological research, especially to test the toxicity of new drugs and formulations and the biodistribution and the efficacy of novel anticancer and anti-infective therapies, analyzing its advantages and disadvantages compared to animal models. Conclusion: The chick chorioallantoic membrane model shows great utility in several research areas, such as cancer, toxicology, biodistribution studies and anti-infective therapies. In fact, it has become an intermediate stage between in vitro experiments and animal studies, and, in the case of toxicological studies (skin and ocular toxicity), has even replaced the animal models.

A note on the occurrence of chevkinite, allanite, and zirkelite on St. Kilda, Scotland

1982 ◽  
Vol 46 (341) ◽  
pp. 445-448 ◽  
Author(s):  
R. R. Harding ◽  
R. J. Merriman ◽  
P. H. A. Nancarrow
Keyword(s):  
Rare Earth ◽  
Great Britain ◽  
Electron Probe ◽  
Energy Dispersive ◽  
X Ray Diffraction ◽  
Electron Probe Analysis ◽  
Accessory Minerals ◽  
X Ray ◽  
Probe Analysis ◽  
Recorded Occurrence

AbstractThe occurrence of three accessory minerals with significant rare earth contents in Tertiary acid rocks of St. Kilda is described. Allanite, zirkelite, and chevkinite were identified by electron probe analysis (with energy-dispersive attachment) and the chevkinite confirmed by X-ray diffraction. Brief comparison is made with other Tertiary occurrences of RE minerals. This is the first recorded occurrence of chevkinite in Great Britain.

Electron Probe Microanalysis of Zinc-Bearing Hexagonal Ferrites

1965 ◽  
Vol 9 ◽  
pp. 304-313
Author(s):  
J. R. Shappirio
Keyword(s):  
Electron Probe ◽  
Hexagonal Ferrites ◽  
Structural Units ◽  
Electron Probe Analysis ◽  
X Ray ◽  
Layer Structures ◽  
Cell Data ◽  
Unit Cell Data ◽  
The Ideal

AbstractThe electron probe is shown to be an effective tool for the analysis of the series of ferrimagnetic oxides referred to as the hexagonal ferrites. This series of compounds) containing barium, Fe3+, and a divalent metal cation, is formed by an ordered stacking of basic structural units in varying ratios. The ideal, complex stoichiornewy of these polytype-like mixed-layer structures can be computed from X-ray unit cell data; the various structures and their predicted stoichiometry are reviewed. Results of electron probe analysis of zinc-bearing single-crystal hexagonal ferrites are compared with theoretical values, the various correction procedures applied to the probe data are presented, and the limitations of the method in the analysis of hexagonal ferrites are discussed. The information obtained from this study has laid the groundwork for the determination of chemistry in substituted members of the hexagonal ferrite group, and will contribute significantly to the interpretation of the magnetic properties exhibited by these compounds.

Cosmochlore—a new examination

1981 ◽  
Vol 44 (335) ◽  
pp. 265-267 ◽  
Author(s):  
A. G. Couper ◽  
M. H. Hey ◽  
R. Hutchison
Keyword(s):  
Electron Probe ◽  
Optical Data ◽  
Electron Probe Analysis ◽  
X Ray ◽  
Probe Analysis

AbstractExamination of cotype cosmochlore from the Toluca meteorite confirms Laspeyres's observations (1897) in every respect, except that what he determined as iron was largely titanium. His data are completed by an electron-probe analysis and by full optical and X-ray data. Accepting the identity of cosmochlore and ureyite, the optical data of Frondel and Klein (1965) for the latter are partly in error or misprinted.

scholarly journals Untersuchungen am System Vanadium—Gallium

1966 ◽  
Vol 21 (5) ◽  
pp. 531-540 ◽  
Author(s):  
R. G. Maier ◽  
Y. Uzel ◽  
H. Kandler
Keyword(s):  
Crystal Structure ◽  
Phase Diagram ◽  
Electron Probe ◽  
Liquidus Curve ◽  
X Ray Diffraction ◽  
Equilibrium Conditions ◽  
Electron Probe Analysis ◽  
X Ray ◽  
Oxygen System ◽  
Annealing Experiments

The phase diagram of the vanadium-gallium system was investigated by means of thermoanalysis, microscopy, x-ray diffraction, and electron probe analysis.The liquidus curve was measured in the range from 40—80% Gallium. The existence of the known phases V3Ga (Cr3Si-typ), V6Ga5 (Ti6Sn5-typ), V6Ga7 (Cu5Zn8-typ), V2Ga5 (Mn2Hg5-typ), V4GaO and V5Ga3Ox (Mn5Si3-typ) was reestablished. The existence of V3GaOx and V5 (Ga, Si)3Ox is stated and their crystal structure investigated.It is shown that the oxygen content of he samples greatly influences the equilibrium conditions of the system. By means of annealing experiments and dilatometric measurements the phase diagram of the vanadium-gallium-oxygen system was investigated in the range of small oxygen contents.

scholarly journals Isolation and characterization of an inhibitor of neovascularization from scapular chondrocytes.

1992 ◽  
Vol 119 (2) ◽  
pp. 475-482 ◽  
Author(s):  
M A Moses ◽  
J Sudhalter ◽  
R Langer
Keyword(s):  
Growth Factor ◽  
Potent Inhibitor ◽  
Chorioallantoic Membrane ◽  
Boyden Chamber ◽  
Chick Chorioallantoic Membrane ◽  
Isolation And Characterization ◽  
Apparent Homogeneity ◽  
Sds Page ◽  
And Migration

An inhibitor of neovascularization from the conditioned media of scapular chondrocytes established and maintained in serum-free culture has been isolated and characterized. To determine whether this chondrocyte-derived inhibitor (ChDI) was capable of inhibiting neovascularization in vivo, this protein was assayed in the chick chorioallantoic membrane assay. ChDI was a potent inhibitor of angiogenesis in vivo (4 micrograms = 87% avascular zones). This inhibitor is also an inhibitor of fibroblast growth factor-stimulated capillary endothelial cell (EC) proliferation and migration, as well as being an inhibitor of mammalian collagenase. ChDI significantly suppressed capillary EC proliferation in a dose-dependent, reversible manner with an IC50 (the inhibitory concentration at which 50% inhibition is achieved) of 2.025 micrograms/ml. Inhibition by ChDI of growth factor-stimulated capillary EC migration was also observed using a modified Boyden chamber assay (IC50 = 255 ng/ml). SDS-PAGE analysis followed by silver staining of ChDI purified to apparent homogeneity revealed a single band having an M(r) of 35,550. Gel elution experiments demonstrated that only protein eluting at this molecular weight was anti-angiogenic. These studies are the first demonstration that chondrocytes in culture can produce a highly enriched, potent inhibitor of neovascularization which also inhibits collagenase.

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