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Full-Text Articles in Life Sciences
Strontium And Bromide As Tracers In X-Ray Microanalysis Of Biological Tissue, Joanna Wroblewski, Samuel Sagström, Helmy Mulders, Godfried M. Roomans
Strontium And Bromide As Tracers In X-Ray Microanalysis Of Biological Tissue, Joanna Wroblewski, Samuel Sagström, Helmy Mulders, Godfried M. Roomans
Scanning Microscopy
Since energy dispersive X-ray microanalysis cannot distinguish between isotopes of the same element, alternative methods have to be used to get information similar to that obtained in experiments with radioactive tracers. In the present study, strontium was used as a tracer for calcium, and bromide as a tracer for chloride. Rats were injected with strontium chloride in vivo, and the uptake of strontium in the acinar cells of the submandibular gland was studied. Eventually a Sr/Ca ratio of 0.3 was reached. In some animals, secretion of mucus had been elicited by stimulation with isoproterenol 4 h prior to injection …
Bone Lining Cells: Structure And Function, Scott C. Miller, Louis De Saint-Georges, Beth M. Bowman, Webster S. S. Jee
Bone Lining Cells: Structure And Function, Scott C. Miller, Louis De Saint-Georges, Beth M. Bowman, Webster S. S. Jee
Scanning Microscopy
Bone lining cells (BLC's) cover inactive (nonremodeling) bone surfaces, particularly evident in the adult skeleton. BLC's are thinly extended over bone surfaces, have flat or slightly ovoid nuclei, connect to other BLC's via gap junctions, and send cell processes into surface canaliculi. BLC's can be induced to proliferate and differentiate into osteogenic cells and may represent a source of "determined" osteogenic precursors. BLC's and other cells of the endosteal tissues may be an integral part of the marrow stromal system and have important functions in hematopoiesis, perhaps by controlling the inductive microenvironment. Because activation of bone remodeling occurs on inactive …
Application Of The Pyroantimonate Method And Electron Probe Microanalysis To The Study Of Glycogen Metabolism In Liver, Pascale Mentré, Sylvain Halpern
Application Of The Pyroantimonate Method And Electron Probe Microanalysis To The Study Of Glycogen Metabolism In Liver, Pascale Mentré, Sylvain Halpern
Scanning Microscopy
Glycogen distribution in the liver of mouse under different metabolic conditions was studied by the pyroantimonate (PA) method combined with semi-quantitative electron probe microanalysis (EPMA). In the liver of animals subjected to a sugar-rich diet, glycogen granules were abundant and electron transparent. In fasted animals, they were less numerous and stained by PA, which indicates the presence of a complexed cation. This cation was identified as calcium by EPMA. In both cases, adjacent cytoplasmic areas contained "masked" calcium not revealed by PA but detected by EPMA, which is characteristic of a neutral complexed form; but in the case of the …
Calcium Levels In Ruffle-Ended And Smooth-Ended Maturation Ameloblasts, S. H. Ashrafi, D. R. Eisenmann, A. E. Zaki
Calcium Levels In Ruffle-Ended And Smooth-Ended Maturation Ameloblasts, S. H. Ashrafi, D. R. Eisenmann, A. E. Zaki
Scanning Microscopy
Scanning electron microscopy was used to distinguish the topographical characteristics of two maturation ameloblast types in freeze-dried blocks of enamel organ tissue. This distinction was based primarily upon the configuration of the distal ends of the ameloblasts and the presence or absence of wide intercellular spaces.
Energy dispersive x-ray spectrometry was applied to compare calcium levels in various regions of tissue identified as constituting either ruffle-ended or smooth ended ameloblasts. Greater levels of calcium were found in the distal ends of the ruffle-ended cells than in their proximal ends. In addition, greater calcium levels were found in the distal ends …
X-Ray Microanalysis Of Calcium Containing Organelles In Resin Embedded Tissue, G. Nicaise, I. Gillot, A. K. Julliard, E. Keicher, S. Blaineau, J. Amsellem, J. C. Meyran, M. L. Hernandez-Nicaise, B. Ciapa, C. Gleyzal
X-Ray Microanalysis Of Calcium Containing Organelles In Resin Embedded Tissue, G. Nicaise, I. Gillot, A. K. Julliard, E. Keicher, S. Blaineau, J. Amsellem, J. C. Meyran, M. L. Hernandez-Nicaise, B. Ciapa, C. Gleyzal
Scanning Microscopy
The localization of calcium in cell organelles at the electron microscope level is often achieved through cytochemical techniques, and verified by X-ray microanalysis. Various methods have been used to cytochemically detect calcium or calcium-binding sites : calcium loading, calcium substitution by strontium, barium, or even lead, and calcium precipitation by oxalate, phosphate, fluoride, or pyroantimonate. Their results may have heuristic value, particularly in preliminary studies of poorly known cell types. A complementary and more physiological approach is offered by quantitative measurement of the total calcium content of organelles after cryofixation.
Resin embedding is less demanding than cryomicrotomy and gives better …