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PubMedDate not supplied

Copper in green hair: a quantitative investigation by electron probe x-ray microanalysis.

Eleven cases of green hair were collected and hair tips were analyzed in the electron microscope by energy-dispersive x-ray microanalysis. In all cases, remarkable copper concentrations could be demonstrated (0.2-1.8% w/w). In normal hair the concentration of copper was below the detection limit (0.02% w/w). Analyses of hair cross sections showed a concentration gradient from the periphery toward the center, the periphery having higher values. This observation is in agreement with suspected contamination of the hair with copper from extraneous sources: analysis of the tapwater in patients' homes showed elevated copper concentrations. In addition, the water showed aggressive properties (pH outside the recommended range, high nitrate concentrations, heavily chlorinated). Investigations by transmission electron microscopy showed damage in the endocuticula. Experimental studies of normal unaffected hair fibers showed that treatment with a copper salt alone could result in binding of copper to the hair but that the extent of copper binding could be greatly increased by damaging the cuticula with chlorinated water. It is suggested that aggressive water attacks copper tubings leading to increased copper concentrations in tapwater and causes cuticular damage, which facilitates entry of copper into the hair.

Adolescent↗
PubMedDate not supplied

Renal hemosiderosis due to thalassemia: a light and electron microscopy study with electron probe X-ray microanalysis.

A kidney biopsy specimen with pronounced hemosiderosis from a patient with beta-thalassemia major was studied by light and electron microscopy, including X-ray microanalysis. Ferritin was absorbed from the glomerular ultrafiltrate through the parietal epithelial cells and the tubular epithelial cells and from the blood through the endothelial cells. It was transported in siderosomes into the surrounding basal lamina, where electron-dense deposits of hemosiderin were found in the outer part of the lamina densa and the reticular lamina. Fibrosis was seen as a reaction to the iron followed by severe atrophy of affected structures.

Adolescent↗
PubMed1999

Effects of tension at the site of coaptation on recovery of sciatic nerve function after neurorrhaphy: evaluation by walking-track measurement, electrophysiology, histomorphometry, and electron probe X-ray microanalysis.

The effects of tension at the site of coaptation on recovery of sciatic nerve function after neurorrhaphy were studied by evaluating walking-track measurements, nerve conduction velocity measurements, histomorphometry, and electron probe X-ray microanalysis. Forty adult male Lewis rats underwent right sciatic nerve (SN) transection followed by one of four different nerve repair procedures (N = 10 rats per group). In Group 1, the gap was repaired by end-to-end epineural coaptation. In Group 2, a 5-mm segment of SN was resected, and the defect was repaired under high tension by epineural neurorrhaphy. In Group 3, a 5-mm segment of SN was resected, and the defect was repaired with a 5-mm interposition nerve graft. In Group 4, a 5-mm segment of SN was resected. Then, to lessen the tension that follows neurorrhaphy, an anchoring suture was added. Finally, end-to-end coaptation was performed. Walking-track analysis showed better functional recovery in Group 1 than in Group 2, and better recovery in Group 3 than in Group 2. Group 4 showed a tendency toward better recovery comparing with Group 2. Electron probe X-ray microanalysis revealed higher Na, Cl, and K peaks in axoplasm accompanied by increase in the endoneural fluid pressure (EFP) in Group 2 than those of Group 1. This higher level of Na, Cl and K may be due to impairment of axonal sodium and potassium transport mechanism in Group 2. Increase in EFP may affect nerve regeneration.

Action Potentials↗
PubMed1999

Abnormal mineral composition of osteogenesis imperfecta bone as determined by electron probe X-ray microanalysis on conventional and cryosections.

Osteogenesis imperfecta (OI) is a genetic disorder of the connective tissue characterized by frequent bone fractures. The cause of bone fragility is still unknown even though substantial work on collagen has been done. We measured the calcium to phosphorus ratio (Ca/P) of bone mineral from 35 OI bone samples and 25 age- and site-matched control specimens, using electron probe X-ray microanalysis in the transmission electron microscope. Ultra-thin cryosections and conventionally prepared resin sections were used. Cryo-ultramicrotomy avoids any possible artifactual demineralization that may occur in conventional aqueous media. The Ca/P ratio obtained by these two methods was compared and there was no statistical difference between them. The results were differentiated according to the clinical types of OI for the first time. The Ca/P ratio of OI bone mineral was lower than normal in both resin and cryosections, and mirrored the severity of the disease. OI type II had the lowest ratio (Ca/P = 1.49) compared with normal age- and site-matched controls (Ca/P = 1.69). This abnormal mineral composition in OI type II could be a contributory factor to bone fragility in OI bone.

Adolescent↗
PubMed1996

Elemental composition of Na pump inhibited rabbit aorta VSM cells by electron probe X-ray microanalysis.

The Na pump in vascular smooth muscle (VSM) is likely to influence not only intracellular Na content but also the content and distribution of other cations and anions measured by electron probe X-ray microanalysis (EPXMA). The hypothesis we tested was that EPXMA of pump-inhibited VSM would yield a characteristic cellular elemental profile, providing insight into the contribution of the Na pump to the intracellular milieu and an approach to identifying when VSM operates under the constraints of pump inhibition. We assessed the contractile state and elemental EPXMA profile of rabbit aorta that was either quiescent or contracted by serotonin (10(-6) M) or ouabain (10(-6) M). VSM cytoplasm showed the anticipated low Na (28 +/- 2 mM) and high K (182 +/- 5 mM) content. With ouabain, Na rose and K fell to reverse the Na-to-K ratio (0.15 +/- 0.01 vs. 6.6 +/- 0.3; P < 0.01). With serotonin, the ratio rose slightly (0.28 +/- 0.2; P < 0.05). Nuclei and mitochondria showed a similar pattern. CI showed a small increase (56 +/- 2 to 102 +/- 4 mM) with ouabain, a shift that could not be accounted for on the basis of charge redistribution to maintain neutrality because the change in Na and K were essentially offsetting. EPXMA measures total and not ionized Ca. If changes in cytoplasmic Ca occurred, they were too small to be measured by the imaging methods employed. The sustained, myogenic contractile response of VSM to Na pump inhibition shows a characteristic elemental profile that could prove useful in its identification. Direct measurement of membrane potential during the myogenic response to Na pump inhibition should have a high priority.

Animals↗
PubMed1981

Localization of DNA phosphorus in Tipula iridescent virus by oxygen plasma microincineration. II. Electron probe X-ray microanalysis of ash constituents.

Microincinerated, 1-micrometer sections of Tipula iridescent virus (TIV) crystals were analyzed quantitatively with a wave-length-dispersive electron microprobe to determine the chemical composition of high-resolution ash patterns previously obtained from ultrathin sections of the same specimen (Thomas RS: J Histochem Cytochem 29:379, 1981). Parallel analyses were performed on intact sections. In some cases, the same section and probe tracks were analyzed both before and after ashing. The principal elemental constituent of the ash was phosphorus, representing nearly all of the phosphorus found in the unashed sections. This confirmed the likely DNA origin of most of the ash. Other elements--sulfur, calcium, sodium, and perhaps carbon and nitrogen--found in relatively small concentrations in the ash, were partly due to either to incomplete ashing or to a particulate contaminant. Similar plasma ashing and analyses of sectioned model preparations of polymethacrylate containing dissolved triphenyl phosphate confirmed that phosphorus, by itself, could be retained as a stable ash. Analyses of polymethacrylate containing aluminum as well as phosphorus disclosed an unexpected artifact--aluminum inhibited the plasma ashing. These results suggested that the wavelength-dispersive probe, able to analyze for carbon and nitrogen as well as mineral elements, should be a generally useful tool in analyzing plasma microincineration phenomena, where macroscopic results do not apply. Relatively high beam intensity used throughout the probe analyses caused obvious damage to intact sections, particularly when they were mounted on thin-film supports. In contrast, the ash appeared quite stable. This suggested that plasma ashing of biological sections, converting them into mineralogical specimens, may be generally useful in probe analyses of mineral constituents, permitting greater sensitivity via higher beam currents, higher mineral concentrations, and lower backgrounds.

Aluminum↗
PubMedDate not supplied

Characterization of atmospheric particles by electron probe X-ray microanalysis.

Microchemical glass standards were used to validate a quantitation method based on peak-to-background (P/B) ratios from electron probe x-ray microanalysis spectra. This standardless method was applied to the determination of concentrations of individual particles from Malpha or Lalpha lines, as well as from Kalpha lines. The algorithm was tested on particulate glass samples for diameters ranging from 1 to 20 microm. The determined concentrations did not depend on particle size. The certified values for elements were well matched, except for Na, which may migrate under electron bombardment. Finally, classification of qualitative results obtained for aerosol particles was completed by the P/B quantitative method.

Journal Article↗
PubMed1983

Elemental composition of the dense bodies of rat platelets determined by electron probe x-ray microanalysis of freeze-substituted sections.

A semiquantitative x-ray microanalytical study was made of dense bodies in rat and human blood platelets prepared by freeze substitution. After the freeze substitution, electron dense bodies containing 5-hydroxytryptamine(5-HT) were well preserved. Electron probe x-ray microanalyses clearly defined species differences in the cations of dense bodies of rat and man. Direct calculation of elemental concentration ratios demonstrated a high level of Mg, with lesser amounts of K and Ca in rat, while there was a negligible level of Mg in man but a high amount of Ca. These results indicate that freeze-substitution is a suitable preparation for the study of diffusible electrolytes which may open the way to quantitative analysis using appropriate standards for analytical electron microscopy of resin sections.

Animals↗
PubMed1987

Microincineration and elemental X-ray microanalysis of single Bacillus cereus T spores.

Single whole spores of bacillus cereus T were analyzed by scanning electron microscopy and electron microprobe X-ray microanalysis before and after high-temperature (600 degrees C) ashing in air. High-temperature ashing consisted of a centripetal oxidation of the spore surface combined with pyrolysis of the spore's interior. Ashing of single spores produced a compact central ash particle, mimicking the much larger unashed spore body in outline but containing craterlike microregions, and a peripheral thin ash film. Ashing mostly eliminated the spore's organic matrix; however, ash residues still gave residual carbon-characteristic X-ray counts. Ashing of single spores produced a two-, five-, and six-fold increase of potassium, magnesium, and calcium X-ray intensities, respectively. Iron, although low in actual counts, became detectable after ashing. Phosphorus characteristic X-rays were decreased by 41% after ashing, while volatilization lowered sodium and manganese X-ray intensities by over 80%. High-temperature ashing enhanced element-characteristic X-ray intensities of the non-volatilizable mineral(ized) elements of spores by compacting them into ash residues, more so than by simply abolishing their organic matrix. Microincineration appears a generally useful preconcentration technique for elemental detection and localization in X-ray microanalysis.

Bacillus cereus↗
PubMed1977

Electron probe x-ray microanalysis of small granulated cells in rat sympathetic ganglia after sequential aldehyde and dichromate treatment.

Rat adrenal medulla and celiac-mesenteric sympathetic ganglia were fixed by a glutaraldehyde/formaldehyde-potassium dichromate-osmium treatment sequence and plastic-embedded. Fine sections were examined by electron probe x-ray microanalysis. Comparable peaks for chromium (Kalpha = 5.4 keV) were obtained from cytoplasmic fields containing membrane-bounded inclusion granules in both adrenomedullary noradrenaline cells and a type (type II) of sympathetic small granulated cell whose inclusion granules closely resemble those of the adrenomedullary noradrenaline cell. Chromium was not detected in granules within adrenomedullary adrenaline cells nor in two other sympathetic small granualted cell types. In no material was chromium detected in agranular cytoplasmic or nuclear fields. Since chromium binds to the Schiff monobase formed by glutaraldehyde and noradrenaline during fixation, we infer that noradrenaline is present in the granules of the type II sympathetic small granulated cell, as well as in adrenomedullary noradrenaline cells.

Adrenal Medulla↗
PubMed1982

The elemental composition of the chloragosomes of two earthworm species (Lumbricus terrestris and Allolobophora longa) determined by electron probe X-ray microanalysis of freeze-dried cryosections.

The elemental composition of the chloragosomes of the two earth-worm species, one with complex highly active Ca-secreting calciferous glands (L. terrestris) and the other with non-secretory glands (A. longa), was determined by the electron probe X-ray microanalysis of unfixed freeze-dried cryosections. The predominant constituents of the chloragosomes of both species were P, Ca, Zn and S, with lesser quantities of K, Cl and Fe. The most striking species differences in chloragosomal chemistry were the higher concentrations (expressed as relative mass fractions) of P(x 2.1), Ca(x 1.5), and Zn(x 2.3) in L. terrestris, and the much higher S(x 19.6) in A. longa. These differences were discussed in relation to the general ecophysiology of the two species, and more specifically in relation to heavy metal uptake and binding.

Animals↗