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PubMed1986

Ca++ localization in boar spermatozoa by the pyroantimonate technique and X-ray microanalysis.

Intracellular, loosely bound Ca++ has been localized electron microscopically in freshly ejaculated boar spermatozoa by in situ precipitation with potassium antimonate. Ca++ was identified as the cation precipitated by testing the EGTA-sensitivity of the precipitates and by X-ray microprobe analysis. The data obtained revealed that the outer acrosomal membrane is the preferential site for Ca++ precipitation in the sperm head.

Animals↗
PubMed1992

The role of the rat submandibular gland in the excretion of bis (tributyltin) oxide: electron microscopy, X-ray microanalysis and atomic absorption analysis.

The role of the submandibular glands in the excretion of parenterally administered bis (tributyltin) oxide (TBTO) was studied. Fine structural alterations of the submandibular glands were observed with an electron microscope. Accumulation sites of TBTO were determined with an X-ray microanalyzer and tin concentrations in saliva and blood were measured by atomic absorption spectrophotometry.

Animals↗
PubMed1992

Preparation of aqueous standards for low temperature X-ray microanalysis.

A technique, using Nuclepore polycarbonate membrane filters as a containing medium for very small volumes of ionic standard solutions, to produce homogeneous ice standards is described. The standards are suitable for use in a scanning electron microscope. The relationship between elemental X-ray counts and ionic concentration is found to be linear. The method is rapid and simple. Minimum detectable concentrations are given.

Electron Probe Microanalysis↗
PubMed1993

Fine structure and elemental composition of fresh and frozen dog spermatozoa.

Dog spermatozoa from fresh ejaculates and after freezing-thawing were air-dried on to grids and subjected to X-ray microanalysis or examined by scanning and transmission electron microscopy. The spermatozoa subjected to freezing-thawing presented major changes in their morphology, which included the loss of acrosomal contents, seen both by the swelling and rarefaction of the acrosome and the loss of electron-dense acrosomal material. In many cells the acrosomal damage, including the equatorial region, was conspicuous, with vesiculization of the acrosomal membranes. The plasmalemma remained, in most cases, apparently intact. X-ray microanalysis of the sperm aliquots showed a significant decrease in the amount of most selected elements after freezing-thawing. The extent to which concentrations of phosphorus and sulfur decreased in the sperm head region suggested that major changes in the chromatin occurred during the freeze-thaw process.

Acrosome↗
PubMed2001

Observation of impurities in ice.

This paper presents a new method for determining the microstructural location of impurities in polycrystalline ice, which involves allowing the ice to sublimate under vacuum and then identifying the concentrated impurities using energy dispersive X-ray microanalysis in a low-vacuum scanning electron microscope. The method allows the presence of impurities in both the grain boundaries and the lattice of natural polycrystalline ice to be observed. Using this technique on natural ice, filaments consisting chiefly of NaCl were observed in some grain boundaries, small amounts of sulfur and chlorine were found in the grain interiors of the ice, and large concentrations of sulfur were observed in inclusions.

Electron Probe Microanalysis↗
PubMed1991

Calcium content and concretions of pineal glands of young and old rats. A scanning and X-ray microanalytical study.

Calcium content and pineal concretions were studied in young (2-3 months) and old (28 months) Wistar rats. Samples, deep-frozen by liquid propane isopentane and freeze-dried were analysed by means of X-ray microanalysis in a scanning electron microscope. Total semi-quantitative measurements revealed that pineals of old rats showed a marked increase of calcium compared with the pineals of young rats. It is thus suggested that a calcium-rich environment is responsible for the growth of pineal concretions, which only appear in old rats. Pineal calcifications in rats could thus be an indicator of aging and/or of a degenerating state.

Aging↗
PubMed2004

An ultrastructural study of cellular response to variation in porosity in phase-pure hydroxyapatite.

Hydroxyapatite has been shown to be biocompatible and bioactive. Incorporation of porosity has been shown to enhance osteointegration; however, difficulty in controlling the extent and type of porosity has limited investigation into determining the role of both macro- and microporosity. The current investigation reports on the synthesis of four types of phase-pure hydroxyapatite with varying levels of porosity (HA1-HA4), and with defined levels of macro- and microporosities. Transmission electron microscopy was used to evaluate qualitatively the effect of these two parameters on cell-material interactions following a 30-day incubation period. Biological mineralization was observed within vesicles and the needle-like minerals were confirmed as hydroxyapatite using X-ray microanalysis. This demonstrated the suitability of primary human osteoblast-like cells as a tool to assess the extent of mineralization. Furthermore, internalization of hydroxyapatite particles was observed. Our findings show that the variation in macro- and microporosity does not affect the extent of cell-material interaction, with collagen synthesis evident in all samples.

Cell Communication↗
PubMed1990

Ion distribution in leaf cells of Egeria densa.

The lement concentrations of intracellular compartments of leaf cells of Egeria densa are estimated by X-ray microanalysis. Ultrathin frozen-dried sections are used in TEM mode. The concentrations of Na, Mg, P, Cl, K, and Ca are determined in the cell wall, cytoplasm and chloroplasts. The cell wall represents a Donnan free space with a negative fixed charge concentration of 360 mval/l water. The water fraction of the cytoplasm is between 85 and 90% and strikes the bounds of possibility of that method.

Chloroplasts↗
PubMed1993

The antibacterial activity of haemin compared with cobalt, zinc and magnesium protoporphyrin and its effect on potassium loss and ultrastructure of Staphylococcus aureus.

The unique antibacterial properties of Fe-protoporphyrin (haemin) on Staphylococcus aureus, compared to Co-protoporphyrin (Co-PP), Mg-protoporphyrin (Mg-PP) and Zn-protoporphyrin (Zn-PP) are described. Only haemin (20 microM) exhibits a strong light-independent antibacterial effect on S. aureus; the other metalloporphyrins, Co-PP, Mg-PP or Zn-PP, have no antibacterial effect in the dark. Only light photosensitization of Mg-PP-treated cells resulted in the inhibition of the bacterial growth, while Co-PP or Zn-PP were photodynamically inactive. A notable effect of haemin on inactivation of S. aureus was the induction of immediate ion fluxes as determined by X-ray microanalysis (XRMA) of fast-frozen cells. A marked efflux of K (96%) and Cl (94%) was expressed immediately as determined by X-ray microanalysis of S. aureus cells treated with haemin for 5 min. Only 48% loss of Na was detected in the cells under these treatment conditions, while P content was increased by 150%. Electron microscopy analysis revealed the appearance of a mesosome-like structure connected to the new septa, filamentous chromosome and arrays of aggregated ribosomes in the cytoplasm. We propose that haemin has multiple cellular targets for its oxidative effect in S. aureus.

Anti-Bacterial Agents↗
PubMed1991

Biological calcium absorption edge imaging using monochromatic synchrotron radiation.

Soft X-ray contact absorption edge images of unfixed, unstained biological specimens were made using monochromatic synchrotron radiation. X-ray contact replicas of unfixed, hydrated biological specimens at the nitrogen absorption edge and above and below the CaLIII absorption edge were compared to comparative conventional morphological and elemental high-resolution imaging methods (scanning and transmission electron microscopy, TEM-histochemistry and TEM-X-ray microanalysis). Soft X-ray absorption edge images made above the calcium absorption edge clearly revealed morphological detail and identified regions ladened with calcium as verified by TEM histochemistry of identical spores. Similarly, nitrogen absorption edge images identified residual nitrogenous material in the spore resuspension medium, and non-viable spores with nitrogen loss due to protoplast disaggregation.

Bacillus subtilis↗
PubMed1982

The effect of orally administered cadmium on the ultrastructure of the rat prostate.

The effects of cadmium and nickel chloride, administered in drinking water at 5 and 50 ppm, on the rat prostate are described. Zinc concentrations in the two lobes of the gland were unaffected by the metals and no consistent changes were observed at the subcellular level by X-ray microanalysis. The ultrastructural appearance of the prostate gland in rats of varying ages was unaltered following cadmium administration at those levels, while plasma testosterone concentrations did not differ significantly in cadmium treated animals. Low levels of cadmium (less than 5 ppm) were accumulated by the ventral lobe of the prostate, although the metal was not detectable subcellularly. The results are discussed in relation to human prostatic carcinoma.

Administration, Oral↗
PubMed1984

Fe-rich corpuscles in Diplogonoporus grandis detected using X-ray microanalysis.

An energy dispersive X-ray microanalysis of the individual corpuscles in the parenchyma of Diplogonoporus grandis was performed for the chemical identification of their inorganic composition. Besides the corpuscles showing distinct peaks for calcium, a major inorganic element, a type of corpuscle showing distinct peaks for iron was observed. It is suggested that it is necessary to examine not only the whole corpuscles isolated but also individual corpuscles in the tissue when studying the nature and roles of corpuscles in cestodes.

Animals↗
PubMed1984

Deposits on hydrophilic 'bandage' lenses. A scanning electronmicroscopic and x-ray microanalytic study.

Scanning electronmicroscopy of 34 continuously worn Sauflon PW 'bandage' lenses showed an initial deposition of cellular debris, followed by an increasing, general, non-penetrating, organic coating, particularly on the anterior lens surface. No microorganisms were found. X-ray microanalysis of the 34 Sauflon PW lenses as well as 11 daily worn Hydroflex m lenses showed that elements may be added to or 'washed out' from the lenses during storage before preparation for microscopy. The elements obtained were constituents of both normal tear fluid and lens storage solutions. Only sulphur appeared firmly bound in the deposits, probably as sulphur-containing macromolecules of ocular mucus. Calcium was only detected in a few cases.

Contact Lenses, Hydrophilic↗
PubMed1995

The isolation and characterization of magnesium whitlockite crystals from human articular cartilage.

A number of basic calcium phosphate crystals have been demonstrated in human articular tissues. The exact relationship between crystal deposition and disease remains obscure, although there is evidence supporting a rapid degenerative arthropathy within a specific set of patients. Limited reports of 'cuboid' calcium phosphate microcrystals in articular cartilage have been made over the last 10 years. In this study the occurrence of such crystals, not apparent by light microscopy, in human articular cartilage has been confirmed by transmission electron microscopy and X-ray microanalysis of tissue prepared by aqueous and anhydrous processing techniques. A crystal isolation technique involving collagenase digestion, centrifugation and sodium hypochlorite treatment was developed enabling crystal characterization by electron and X-ray diffraction. Crystals were identified as magnesium whitlockite; the first report of this mineral in articular cartilage. The presence of this mineral phase in normal and osteoarthritic articular cartilage is discussed with consideration given to physical conditions known to favor whitlockite formation and those extant in articular cartilage.

Calcium Phosphates↗
PubMed1992

An evaluation of smear layer with various desensitizing agents after tooth preparation.

According to hydrodynamics, any agent blocking the dentinal tubules reduces the flow of fluids and diminishes hypersensitivity. The properties of the desensitizing agents that sponsor tubular occlusion and the barrier efficiency resulting from the interaction of the smear layer with test materials were examined with the scanning electron microscope and energy-dispersive x-ray microanalysis. Selected dentinal desensitizing was accomplished with burnishing procedures, cavity varnish, calcium hydroxide, and topical fluoride. Subjective evaluations were also recorded clinically after tooth preparation. This investigation indicated that the smear layer did not protect against zinc phosphate cement, and that cavity varnish prevented the formation of the smear plugs. The smear layer and plugs were basically composed of calcium and phosphorus, the major ingredients of dentin.

Adult↗
PubMedDate not supplied

Elemental composition of ischemic myocardium determined by x-ray microanalysis.

Elemental composition of ischemic myocardium was attempted with x-ray microanalysis. Energy dispersive spectrum exhibited calcium K alpha and phosphorus K alpha peaks from mitochondrial deposits, and Ca K alpha peaks from nucleus, contraction bands, and Z lines of the ischemic myocardial cell. Ca and P contents were confirmed with wavelength dipersive spectrometers. Mg was present in the mitochondrial deposits which lacked Ca. This study suggests a formation of phosphate salt of Ca at different intracellular sites and also of Mg with mitochondrial deposits.

Animals↗
PubMed2003

Ultrastructural analysis of salivary calculus in combination with X-ray microanalysis.

Ultrastructural studies of salivary calculi were performed. Scanning electron microscopic examination of the calculi revealed lamellar and concentric structures. Granular or globular structures and pyramid structures were found on the surface of the calculi, and in some cases a scaly structure corresponding to fiber and bacteria was recognized. X-ray microanalysis showed the main constitutes of the calculi to be Ca and P. Transmission electron microscopic examination revealed a fine fibrous structure near the degenerated organelles, and analyses of the structure by electron diffraction revealed hydroxyapatite. Calcification was found around the degenerative organelles in the form of lipid-like structures, mitochondria, lysosomes, and microbial structures. Judging from our results, as one of the processes leading to calculi formation, it is speculated that degenerative substances are emitted by saliva, by some phenomenon, and calcification around these substances then occurs, contributing to the formation of calculi.

Electron Probe Microanalysis↗
PubMed1995

Contamination of titanium castings by aluminium oxide blasting.

OBJECTIVES: It is desirable that the surfaces of surgical implants be uncontaminated by foreign materials to avoid untoward tissue reactions, and grit blasting is widely assumed to leave clean metal surfaces. SEM examination and X-ray microanalysis of a recovered 'pure' titanium implant casting that was associated with tissue breakdown revealed embedded particles of alumina. The casting had been cleaned of investment by blasting with alumina grit. METHODS: A variety of treatments of cast titanium plates was used: (a) to establish that the observed aluminium was due to the blasting grit, and (b) to determine whether removal of investment could be achieved effectively by other means. SEM examination and X-ray microanalysis were used. RESULTS: The detected aluminium was associated with embedded fragments identified as coming from the blasting grit. Acid-pickling and mechanical (rotary instrument) trimming produced minimally contaminated surfaces. CONCLUSIONS: Whilst unproven, the presence of the alumina is viewed with great concern as a possible causative agent in the observed tissue breakdown and procedures avoiding alumina blasting are recommended as a precautionary measure.

Aluminum Oxide↗