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At least 37 records · Page 2Linked to original sources
PubMed1977

Identification of stainless steel welding fume particulates in human lung and environmental samples using electron probe microanalysis.

Open lung biopsy specimens from two welders and air samples from their workplace environments were examined with the electron probe microanalyzer. X-ray analysis showed that the majority of particles found in the lung tissue from both workers and in the air samples to be composed of varying amounts of iron, chromium, manganese and nickel, the major components of some types of stainless steel. Based upon these analyses, it was concluded that the majority of the particles in both biopsy specimens were a result of the workplace environment.

Air Pollutants, Occupational↗
PubMed1978

Electron probe microanalysis of red blood cells. I. Methods and evaluation.

The concentrations of potassium, sodium, and iron in human and sheep red blood cells were measured with an electron probe. Cells were prepared for analysis by spraying them on pyrolytic graphite supports. The results obtained with this spray technique agreed well with values measured on similar cells that were prepared for analysis by freezing, sectioning, and freeze-drying. Higher Na concentrations and lower K concentrations were found to be associated with lower cell volumes in human and high-potassium sheep cells. In low-potassium sheep cells the reverse was found, lower Na and higher K concentrations were associated with lower cell volumes. However, the amounts of iron were found to remain relatively constant in all human cells.

Cell Membrane Permeability↗
PubMed1991

Line analysis of interface layer on dentin by means of electron-probe microanalysis.

Three types of brominated methacrylates, SBPPM, BPylM, and BNEM, were synthesized. The distribution of Br, Ca, and Fe at the interface between dentin treated with the 10-3 solution and resin containing these monomers was analyzed using an electron-probe microanalyzer (EPMA) in order to predict the composition and thickness of the interface layer on dentin for the corresponding unbrominated methacrylates. There was no significant difference between the brominated and unbrominated methacrylates in either the bond strength to the treated dentin or in the thickness of the interface layer on dentin observed with a scanning electron microscope (SEM). The thickness determined with EPMA was equivalent to that observed with SEM. The concentration of each brominated methacrylate in the interface layer was higher than the original concentration in the resin monomers, and BNEM showed higher concentration than the others. The presence of Fe in the layer was confirmed by EPMA.

Animals↗
PubMed1990

[Electron-probe microanalysis examination of acid-proof dentin layer].

To predict the presence and thickness of the acid-proof dentin layer by the method of combining the halogenated methacrylate and electron-probe microanalyzer (EPMA), 2-methacryloyloxyethyl hydrogen chloromaleate (CIMEM) used as a base monomer for a bonding agent and 2-bromoethyl methacrylate (2 BEM), 2-(4-bromophenyl)ethyl methacrylate (BPy1EM), 2-(4-bromo-1-naphthyl)ethyl methacrylate (BNEM) and 2,4,6-tribromophenoxy methacrylate (TriBr-PM) used as tracers were synthesized. The bond strength to dentin treated with 37% phosphoric acid solution for 30 sec. was not statistically different for the bonding agents with and without tracers. The SEM micrographs revealed that the layers, which may be acid-proof dentin layers, were 3-4 microns thick at the resin-dentin interface for all bonding agents. According to EPMA analysis, cps of C1Ka and BrLa increase at the same points and the acid-proof dentin layer thickness was about 4 microns.

Acid Etching, Dental↗
PubMed1975

Evaluation of silicon and germanium retention in rat tissues and diatoms during cell and organelle preparation for electron probe microanalysis.

Chemical, radiochemical and x-ray microanalysis assays were used to define parameters of silicon (Si) retention during preparation og biologic samples (rat liver, spleen, kidney, lung, diatoms and cell organelles) for x-ray microanalysis, Due to its longer half-life 68-Fe was used in some cases to trace SI. Leaching of Si from cells and organelles by the aqueous preparation media was overcome by use of the freeze-substitution process. Cells were treated with 30% glycerol hypertonic sucrose medium to reduce ice damage. Embedment in Spurr's low viscosity epoxy resin medium caused no apparent Si loss. A semiquantitative evaluation showed 0.5 x 10-8 to 0.3 x 10-17 g detectable Si in isolated rat liver mitochondria in thin sections, which is within the instrument's range of detection. This study indicateds that the presence of Si in the mitochondria is not the rsult of contamination.

Animals↗
PubMed1977

Electron probe microanalysis of chemical elemental content of single human red cells.

Sodium, potassium, iron and sulfur contents of single human red cells were measured using electron microprobe microanalysis. Three preparative procedures were compared, and the most reliable technique was found to be spraying of cells onto polished pyrolytic graphite by atomization. Primary standards were prepared by adjusting the intracellular electrolyte content of red cells, eliminating the need to correct for X-ray absorption. Samples were stable under the electron beam during analysis, and could be stored for long periods of time. Strong correlations were found between the X-ray intensities of iron and sulfur and between potassium and sodium. X-ray intensities of potassium and sodium were found to be directly proportional to internal ionic content. Large populations of single cells could be analyzed and the distribution of their elemental content studied.

Electron Probe Microanalysis↗
PubMed1992

Electron probe microanalysis of the otolithic membrane. A methodological and quantitative study.

The effect of tissue preparation on calcium and potassium weight percent in the otoconial layer in the utricle and saccule was studied in four groups of OF1 mice with electron probe X-ray microanalysis. Glutaraldehyde and freeze-drying, glutaraldehyde and air-drying, air-drying, and cryo-fixation and freeze-drying were compared. Ca and K changed significantly in the utricle depending on the method used (P < 0.001), and K changed significantly in the saccule (P < 0.001). We chose cryo-fixation with freeze-drying for the quantitative analysis of the otolithic membrane because this method provided the highest values of Ca and K with minimum loss of Ca and K. Microcrystalline salt standards mounted on scanning electron microscopy holders were used for the quantification of Ca and K by the peak-to-local-background (P/B) ratio method. The P/B ratio in standards with reproducible results, when plotted against weight percent, gave a straight line for Ca (r = 0.99, P < 0.001) and K (r = 0.98, P < 0.001). The Ca and K weight percent in otoconia showed similar frequency distributions in the utricle and saccule.

Animals↗
PubMed1979

Electron probe microanalysis of elemental composition of mouse cardiac myocytes during post-natal maturation.

Elemental concentrations in the cytoplasm and nucleus of t tests post-natal mouse myocytes were measured at 2, 4, 8, 16, 32 days and in adults using electron probe X-ray microanalysis. Using an analysis of variance test, significant age dependent changes were found in intracellular potassium, sulfur, phosphorus, and chlorine concentrations (mg/kg dry weight), while sodium and magnesium concentrations did not show significant changes. The application of t tests following linear regression analyses (age versus concentration for each element) did, however, give a significant slope for cytoplasmic sodium, potassium, sulfur, and phosphorus values. The findings correspond closely with an emission spectroscopy-titrimetric study of whole heart ventricle of the same developmental period (Hazelwood and Nichols, '70).

Aging↗
PubMed1991

Electron probe microanalysis of calcium release and magnesium uptake by endoplasmic reticulum in bee photoreceptors.

Honey bee photoreceptors contain large sacs of endoplasmic reticulum (ER) that can be located unequivocally in freeze-dried cryosections. The elemental composition of the ER was determined by electron probe x-ray microanalysis and was visualized in high-resolution x-ray maps. In the ER of dark-adapted photoreceptors, the Ca concentration was 47.5 +/- 1.1 mmol/kg (dry weight) (mean +/- SEM). During a 3-sec nonsaturating light stimulus, approximately 50% of the Ca content was released from the ER. Light stimulation also caused a highly significant increase in the Mg content of the ER; the ratio of Mg uptake to Ca released was approximately 0.7. Our results show unambiguously that the ER is the source of Ca2+ release during cell stimulation and suggest that Mg2+ can nearly balance the charge movement of Ca2+.

Animals↗