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At least 865 records · Page 48Linked to original sources
PubMed1985

X-ray microanalysis of psoriatic skin.

Electron probe x-ray microanalysis was used to study elemental distribution in uninvolved and involved skin from patients with psoriasis, and in skin from healthy controls. Significant differences were found between the involved and uninvolved psoriatic skin. In the involved skin, the concentrations of Mg, P, and K were higher in the stratum germinativum, spinosum, and granulosum, compared to the corresponding strata in uninvolved skin. Neither involved nor uninvolved psoriatic stratum germinativum differed markedly from nonpsoriatic control stratum germinativum. In uninvolved psoriatic skin only a lower level of K was noted. In comparison to uninvolved psoriatic skin, the elemental composition of the various strata of involved psoriatic skin shows a pattern typical for highly proliferative, nonneoplastic cells.

Adult↗
PubMed1984

Occurrence of fibrous sodium aluminumtetrafluoride particles in potrooms of the primary aluminum industry.

Inorganic fibrous particles have been found in the work environment of the primary aluminum industry. Based on scanning electron microscopic analysis, the concentrations ranged from 9 to 720 fibers/cc. The fibers were generally thinner than 0.1 micron in diameter and shorter than 5 microns. By electron microscopy, energy dispersive X-ray microanalysis, and selected area electron diffraction the fibers were identified as sodium aluminumtetrafluoride.

Air Pollutants, Occupational↗
PubMed1988

Intracellular storage of sodium and magnesium in Drosophila Malpighian tubules. X-ray microanalysis of native cryosections.

Using electron probe X-ray microanalysis after cryofixation, cryosectioning and freeze-drying we investigated the content of electron-dark vacuoles in the intermediate cell region of the proximal segment of Malpighian tubules in Drosophila larvae. According to this method these vacuoles store sodium and magnesium in a high correlation (r = 0.98) of 5:1 ratio. Phosphorus, potassium and sulfur are also stored. In the intermediate groundplasm surrounding the vacuoles the element content is different from that in the vacuoles. The significance of vacuolar sodium and magnesium storage for the ionic metabolism is unknown. In addition to Na, Mg, P, K and S the vacuoles also contain 3-OH-kynurenine and other fluorochromes. With the pyroantimonate technique intravacuolar precipitates were demonstrated. X-ray microanalysis of the precipitates revealed sodium and calcium, although following cryofixation calcium was not detectable in the vacuoles by X-ray analysis.

Animals↗
PubMed1989

Crystalloids in salivary gland pleomorphic adenomas.

Two types of crystalloids in salivary gland pleomorphic adenomas were studied by light microscopy and electron microscopy. The first type of crystalloid, the previously described tyrosine-rich crystalloid, was identified in three (1.5%) of 205 cases. The crystalloids by light microscopy assumed a radial configuration, resulting in the characteristic petal-shaped morphology. Transmission electron microscopy revealed them to be electron-dense, lobular projections without internal structure. Scanning electron microscopy demonstrated a range of morphology from rounded and intact doughnutlike structures to aggregates of irregular, loosely cohesive plates. The crystalloids were backscatter positive by backscattered electron imaging, and by x-ray microanalysis exhibited prominent calcium, phosphorus, and magnesium peaks that were not present in the adjacent tumor tissue; these three elements may be important in the formation and structure of tyrosine-rich crystalloids. The second type of crystalloid was intraductal and birefringent and was identified in 26 (12.7%) of 205 cases. In 21 of these 26 cases the crystalloids were lost on 10% formaldehyde fixation and paraffin embedding. Histochemical stains and x-ray microanalysis did not reveal a definite chemical composition, but did suggest a predominantly organic nature.

Adenoma, Pleomorphic↗
PubMed1994

X-ray scanning microanalysis of Sporothrix schenckii.

X-ray scanning microanalysis was applied to the study of fungal samples such as Sporothrix schenckii. This technique is sufficiently sensitive to detect many elements in the periodical classification of Mendeleev.

Electron Probe Microanalysis↗
PubMed2000

A study of drug-carrier interactions in dry powder inhaler formulations using the Andersen cascade impactor, X-ray microanalysis and time of flight aerosol beam spectrometry (TOFABS).

The purpose of this study was to determine the in vitro deposition of both drug (albuterol sulfate) and carrier (lactose) particles in relation to each other from a dry powder inhaler formulation using an Andersen cascade impactor (ACI) and time of flight aerosol beam spectrometry (TOFABS). In addition, scanning electron microscopy (SEM) combined with X-ray microanalysis was employed to distinguish albuterol sulfate from lactose. Drug particles apparently penetrated deeper into the impactor than lactose particles contained in the formulation. In some certain stages of impactor, drug particles were separated from lactose particles. Although the TOFABS cannot distinguish between albuterol sulfate and lactose, the TOF spectra obtained from the Aerosizer would appear to be partly indicative of the interactions which exist between drug and carrier. One symmetrical TOF peak was obtained from drug or lactose alone. The TOF peak of the drug was always lower than the TOF of lactose. The times obtained for each powder between experiments were highly reproducible and typical of material and particle size. The use of SEM-X-ray microanalysis also allowed some qualitative characterization of shape and state of association of the two components.

Aerosols↗
PubMed1981

Acridine orange stabilization of glycosaminoglycans in beginning endochondral ossification. A comparative light and electron microscopic study.

This study indicated that acridine orange, when combined with the initial fixative stabilized soluble matrix glycosaminoglycan in situ in areas where considerable glycosaminoglycan extraction is known to occur. Acridine orange was able to diffuse through bone into areas of undecalcified mineralizing cartilage and to bind with the glycosaminoglycans in these areas equally well as in growth plate cartilage matrix. Matrix staining was visible by light microscopy without further staining and was seen to vary territorially in intensity; although cellular definition was poor. This deficiency was overcome by the additional application of p phenylenediamine which stained the cells intensely. At the ultrastructure level, glycosaminoglycan was present as electron dense structures in the cartilage matrix. Preliminary X-ray microanalysis studies confirmed that the acridine orange stained structures contain sulphur; this finding extends the use of acridine orange further to quantitative analysis of glycosaminoglycan.

Acridine Orange↗
PubMed1976

X-ray microanalysis of mitochondrial deposits in ischemic myocardium.

The x-ray microanalysis technique was used to determine the chemical composition of intramitochondrial electron-dense deposits in ischemic myocardial cells. Semi-thin sections were cut from Araldite-embedded tissue and analyzed in a scanning electron microscope equipped with energy- and wavelength-dispersive spectrometers. The energy dispersive spectrum revealed calcium and phosphorus peaks over many mitochondrial deposits. Peak to background ratios of calcium, phosphorus and magnesium obtained with the wavelength dispersive spectrometer were 1.7, 8.8 and 1.2, respectively. There was no consistent relationship in the characteristic peaks of calcium and phosphorus in a given mitochondrial granule. Magnesium appears to be negligible, except in some mitochondrial deposits which lacked calcium, where it was present with a peak to background ratio of two. These results suggest formation of calcium or magnesium phosphate in the mitochondria during ischemia. X-ray microanalysis can provide detailed information on subcellular electrolyte distribution in normal and ischemic myocardial cells and should be attempted with improved methods of tissue preparation.

Animals↗
PubMedDate not supplied

[The characteristics of osteoclast localization in the bones of the extremities of the crested salamander Pleurodeles waltlii].

Localization of polynuclear osteoclasts in limb bones of ribbed newt were analyzed in consideration of calcium content in different bone structures. With using the methods of light and scanning electron microscopy and X-ray microanalysis it was shown that a critical level of cartilage calcification is need to activate osteoclasts. Osseous tissue can bind more calcium salt without resorption.

Animals↗
PubMed1987

Ultrastructural visualization of lipids in trypanosomatids.

An imidazole-buffered osmium tetroxide solution was used to visualize lipids at the ultrastructural level in the following members of the family Trypanosomatidae: Trypanosoma cruzi, T. dionisii, T. vespertilionis. T. rangeli, Crithidia deanei, C. fasciculata, C. oncopelti, and Blastocrithidia culicis. Electron-dense material was seen in various lipid droplets found in all parasites and in the multivesicular structure of members of the sub-genus Schizotrypanum. High contrast of some membranes, mainly those which enclose the mitochondrion, the nucleus, and the endoplasmic reticulum, was observed even in unstained sections. X-ray microanalysis confirmed that the electron density of lipid droplets of B. culicis and membrane-bounded dense granules of C. oncopelti was due to the presence of osmium.

Animals↗
PubMed1991

[Removal of two calcium hydroxide preparations: S.E.M. study].

Calcium hydroxide is one of the most often medication used for temporary treatment in endodontics. Different forms of preparation are available. The aim of this study is to evaluate in vitro the elimination of the pharmaceutical and the commercial forms of presentation. The aspect of the dentinal walls were analysed using SEM and X-ray microanalysis. The results show that Ca(OH)2 removal is difficult but there is no significant difference of elimination between the two forms.

Calcium Hydroxide↗
PubMed2002

Transmission electron microscopic study of early stage gamma(1) (Ag(2)Hg(3)) and beta(1) (Ag-Hg) phases: technical note.

Incomplete reaction, residual free mercury, and high volatility of mercury are often major causes of the discrepancy in chemical composition of gamma(1) measured by different methods. The high mercury volatility also proves to be a major difficulty in transmission electron microscopy (TEM) study of high mercury materials. Provided in this report is a preparation method for TEM thin foils that can largely eliminate the mercury loss problem. The results show that the lattice constant of early stage gamma(1) crystals is 10.05 Delta with a chemical composition of Ag(41.08)Hg(58.92) (or Ag(2)Hg(2.87)). The chemical composition data shows that little or no mercury is lost during specimen preparation. The lattice parameters, a and c, of beta(1) crystals are 3.01 and 4.88 Delta, respectively with a chemical composition of Ag(1.1)Hg(0.94). It seems that the present specimen preparation method allows for accurate TEM microanalysis of high mercury amalgam phases such as gamma(1) and beta(1), which has been extremely difficult to do in the past.

Crystallization↗
PubMed1983

X-ray microanalysis of cultured chondrocytes.

Methodological aspects of X-ray microanalysis of cultured chondrocytes from rabbit auricular cartilage were investigated. The cells were grown on a Formvar-film covered carbon specimen holder with a hole, which allowed examination in STEM. Several different fluids for washing away the culture medium from the cells were used. The effect of these fluids on the elemental composition of the cells was studied. The composition of cultured chondrocytes was compared with that of auricular chondrocytes in situ. Washing with 0.3 M sucrose gave the most satisfactory results. Subsequently, the specimen holders could be frozen in liquid nitrogen and the cells freeze-dried. The effects of human growth hormone on rabbit chondrocytes were investigated by X-ray microanalysis and transmission electron microscopy. Although no ultrastructural effects of hormone treatment could be observed, marked changes in the elemental concentrations in nucleus and cytoplasm of the chondrocytes were detected.

Animals↗
PubMed1986

Histochemistry of colloidal iron stained crystal associated material in urinary stones and experimentally induced intrarenal deposits in rats.

Organic material associated with the calcium oxalate crystals in urinary stones and experimentally induced nephrolithiasis was stained with colloidal iron and analysed by energy dispersive x-ray microanalysis using standard techniques. Iron was positively identified in the stained specimens indicating that some of the organic material is an acidic mucosubstance. The results also indicate that some of the organic material of urinary stones may originate in the kidneys.

Animals↗
PubMed1978

A BASIC-language program for dedicated energy-dispersive microanalysis of thin samples in TEM or STEM.

The program QTHIN combines those methods for processing energy-dispersive X-ray spectra and computing concentrations best suited to thin section microanalysis in TEM or STEM. The program is in BASIC, and so can be modified (for instance for unusual geometries, other matrices such as oxides, etc.). It is suitable for routine use on complex samples with peak overlaps, and for "not-so-thin" samples in which absorption is not negligible.

Computers↗
PubMed1985

Calcification of cartilaginous matrix in culture by constant direct-current stimulation.

Forty-six femora of nine-day-old chick embryos were stimulated by 10 microA of constant direct current via platinum wire electrodes inserted into the diaphyses as cathodes in tissue culture. Apparent calcification in the hypertrophic cartilaginous region of the diaphyses was induced by the electric stimulation. This calcification was most remarkable on both ends of the diaphyses, where fine granules were observed in electron micrographs of the cartilaginous matrix. These granules were aggregates of fine needlelike crystals containing calcium and phosphorous demonstrable by X-ray microanalysis. Incorporation of 45Ca into the femora was significantly increased by the stimulation of up to 247% of the control. This matrix calcification was of interest because it occurred in avian embryonic cartilage that is normally resorbed uncalcified before it is replaced by bone.

Animals↗