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PubMed1975

Intranuclear silicon detection in a subcutaneous connective tissue cell by energy-dispersive x-ray miscroanalysis using fresh air-dried spread.

Silicon was detected by energy-dispersive x-ray microanalysis in the nucleus of a subcutaneous connective tissue cell of mice fed normally. To eliminate contamination, pieces of connective tissue were spread on copper grids and examined without any treatment by an energy-dispersive spectrometer with a scanning transmission apparatus attached to an electron microscope. Scanning transmission electron microscopy of the spread has demonstrated a well-preserved ultrastructure. Fibrous structures, nuclei and nucleoli of cells and mitochondrial granules were recognized. Electron probe analysis showed peaks for silicon at three spots on the nucleus of a cell in addition to those for phosphorus, sulfur, chlorine, potassium and calcium, whereas no peak of silicon could be detected at the spots on nuclei of other cells, mitochondrial granules and electron-lucent area on the same grid as the above. Silicon appears to play a significant role in the nucleus. Applicability of the technique to know the distribution of easily contaminating elements and diffusible substances is shown.

Air↗
PubMedDate not supplied

[Scanning electron microscopy and elementary analytic studies of osteosarcoma].

By scanning electron microscopical (SEM) screening analyses of 14 osteosarcomas characteristic three-dimensional structures of tumor osteoid could be demonstrated. These osteoid formations are highly characteristic for osteosarcoma; we did not find them at any other bone tumor or tumor like lesion until now. With these results a better understanding of characteristic growth patterns of bone tumors could be achieved by SEM. No specific results could be found by elementar analysis, x-ray microanalysis, x-ray fluorescence and x-ray diffractometer techniques. The significance of single interesting values has to be evaluated in the future.

Bone Neoplasms↗
PubMed1982

Localization of calcium in fibrocytes associated with the "substantia amorpha" in the skin of toad, Bufo bufo (L.) (Amphibia, Anura).

Using the potassium pyroantimonate-technique in the fibrocytes associated with the calcium-containing granules of the substantia amorpha within the dermis of Bufo bufo numerous electron-dense deposits have been observed. Reaction product lies in the mitochondria, at the plasma membranes and in various vesicular structures. X-ray microanalysis confirmed that pyroantimonate was predominantly associated with calcium. It is suggested that certain organelles of the fibrocytes are capable of sequestering calcium ions and that the fibrocytes are involved in the Ca-metabolism of the substantia amorpha.

Animals↗
PubMed1976

An X-ray microanalytical azo dye technique for the localization of acid phosphatase activity.

A new method is described for the histochemical localization of acid phosphatase. Naphthol AS BI, enzymatically released from naphthyl AS BI phosphoric acid, is coupled with diazotized 2,5-dibromoaniline to produce a fine insoluble red azo dye. The histochemical and cytochemical localization of this final reaction product in rat liver is described. In the electron microscope, sites of the azo dye can be detected by X-ray microanalysis of ultrathin cryosections of reactive tissue.

Acid Phosphatase↗
PubMed1990

Cadmium toxicity to the cornea of pregnant rats: electron microscopy and x-ray microanalysis.

Cadmium toxicity to the cornea of pregnant rats was studied using the electron microscope and x-ray microanalyzer. In in-vivo experiments, severe corneal edema occurred in pregnant dams that received intraperitoneal injections of cadmium sulphate for 4 days during gestation, but not in nonpregnant rats. Prominent swelling of mitochondria and the occurrence of intra- and intercellular vacuoles in the corneal endothelium were observed only in pregnant dams. In in-vitro experiments, electron-dense deposits consisting of cadmium-oxine complexes were preferentially found in swollen mitochondria of the endothelial cells. Cadmium peaks were obtained from these deposits with x-ray microanalysis. These data suggest that the corneal edema observed after administration of cadmium may imply the disturbance of pump function and barrier function of the corneal endothelium due to the primary toxic effects of this metal on mitochondria.

Animals↗
PubMed1992

Articular cartilage vesicles generate calcium pyrophosphate dihydrate-like crystals in vitro.

OBJECTIVE: To identify the morphology of a mineral-forming of adult porcine hyaline articular cartilage digest and characterize the mineral it forms. METHODS: Electron microscopy, Fourier transform infrared (FTIR) spectroscopy, x-ray microanalysis, compensated polarized light microscopy, and biochemical studies including 14C-labeled UDPG pyrophosphohydrolase radiometric assay. RESULTS: This fraction of articular cartilage digest contained membrane-limited vesicles resembling growth plate cartilage matrix vesicles and formed mineral after only 24 hours in physiologic salt solution containing 1 mM ATP: The mineral contained inorganic pyrophosphate, 95% of which derived from ATP, and phosphate, 93% of which derived from inorganic phosphate in the medium. The FTIR spectrum of this mineral closely resembled the spectrum of standard calcium pyrophosphate dihydrate (CPPD) crystals. Compensated polarized light microscopy showed positively birefringent, rod-shaped crystals morphologically identical to CPPD. Ca:P ratios, defined by energy-dispersive microanalysis, were also consistent with CPPD. CONCLUSION: The articular cartilage vesicle fraction of porcine hyaline cartilage is capable of generating mineral that strongly resembles CPPD.

Adenosine Triphosphate↗
PubMed2003

Limitations on the s-state approach to the interpretation of sub-angstrom resolution electron microscope images and microanalysis.

The s-state approach is useful for analysing transmission electron microscope images of a thin crystalline foil consisting of well-separated atomic columns. It assumes that the signal collected (e.g., the annular dark-field image, the EELS spectrum) can be attributed to only the lowest-energy bound eigenstate of the two-dimensional projected potential of a single column. When, however, columns are close, the form of the bound states depends on more than one column, which implies that interpretation of the signal may not be so simple. For closely spaced columns we show that the simple s-state approach fails for the case of a sub-Angstrom probe initially centred on one column of a pair, because two bound states are excited. The energy in the probe is almost completely transferred to the neighbouring column after it has propagated some tens of nanometres through the foil and then is transferred back. Signals which relate directly to the local probe intensity (e.g. annular dark-field formed by thermal diffuse scattering, EELS) must be analysed in terms of the two bound states. Accurate calculations of bound states of pairs of columns are more demanding than for a single column but sufficient accuracy can be achieved from knowledge of the 1s-states of isolated columns. We provide formulae for the bound states of a column pair. These can be used to determine if image analysis requires the extension to the s-state approach described in this paper.

Algorithms↗
PubMed1985

Placental calcification: ultrastructural and X-ray microanalytic studies.

Calcification is common in human placentas and is widely recognized as a normal part of maturation and aging of this organ. Eleven human placentas were studied by light and electron microscopy to elucidate the mechanism of placental calcification. Earliest mineral deposits were seen along the trophoblastic basement membrane of the chorionic villi undergoing fibrinoid degeneration. Transmission electron microscopic examination revealed crystalline deposits within small membrane-bound vesicles; the latter appear to be derived from degenerating cells and were particularly numerous within the basement membrane. X-ray microanalysis of these deposits revealed calcium and phosphorus peaks and the pattern of calcium hydroxyapatite was noted by electron diffraction. This pattern of calcification, i.e., precipitation of calcium hydroxyapatite in association with extracellular membrane bound vesicles, is similar to that seen in physiologic and pathologic calcifications of other tissues.

Calcification, Physiologic↗
PubMed1992

Characterisation of the ultrastructure of glass-ionomer (poly-alkenoate) cement.

Set glass-ionomer cements were sectioned with a diamond knife and examined in the transmission electron microscope. Their appearance was in accordance with the theoretical structure of these materials, close examination revealing glass particles surrounded by a siliceous layer set in a hydrogel matrix. The elemental composition of each region was determined by X-ray microanalysis (energy dispersive). The results of microanalysis supported the ultrastructural observations, with ions that originated from the glass particles being detected throughout the matrix of the set cement. It was suggested that the mobility of these ions in the matrix phase was important in determining the biocompatibility and adhesive properties of glass-ionomer cements.

Electron Probe Microanalysis↗
PubMed1994

Particles found in lung and brain following subureteral injection of polytetrafluoroethylene paste are not teflon particles.

We injected 0.3 ml. of polytetrafluoroethylene paste (Polytef) behind the left submucosal ureter in 4 mini-pigs and 4 dogs, and 2 dogs and 2 mini-pigs underwent sham operation and acted as controls. Two mini-pigs were injected with 0.5 ml. polytetrafluoroethylene (Teflon) suspended in 50 ml. of normal saline into a peripheral vein and 2 dogs were injected with 0.5 ml. polytetrafluoroethylene into a bladder vein. In addition, 4 dogs were injected with 0.1 ml. polytetrafluoroethylene paste suspended in 20 ml. saline into the right carotid artery. The lungs and brain from half of the animals who had subureteral and intravascular injection of polytetrafluoroethylene paste as well as sham operated animals were dissolved in sodium hypochlorite solution. The resulting organ suspensions were then centrifuged and the smear preparations of the precipitate were examined by polarized light microscopy, scanning electron microscopy and x-ray microanalysis. Polytetrafluoroethylene paste suspended in saline acted as positive control for polytetrafluoroethylene particles. Lungs and brain from the remaining animals were fixed in formalin solution. The brain and lungs of animals who underwent subureteral injection with a minimal amount of polytetrafluoroethylene paste carefully placed in the submucosal plane showed no evidence of polytetrafluoroethylene on histological examination, polarized light microscopy, scanning electron microscopy and x-ray microanalysis.

Animals↗
PubMed1982

X-ray microanalysis of hydrated biological specimens.

Using a wide angle backscattered electron detector (BED), glutaraldehyde fixed or unfixed specimens of biological soft tissues such as hen oviduct, kidney, liver, duodenum of mouse as well as mitochondrial fraction from rat liver were observed under low vacuum (0.3 to 0.5 torr) at magnifications from x300 to 10,000. The backscattered electron images (BEI) of glutaraldehyde fixed hen oviduct were correlated to X-ray microanalysis. Intracellular secretion granules in such unhydrated, uncoated and unstained slices of hen oviduct preserved Ca even after glutaraldehyde fixation. Backscattered electron images of unfixed duodenum and kidney of mice were not satisfactory for observing intracellular structures, though X-ray microanalysis could detect P,S,Cl and K over cut surfaces of such hydrated unfixed tissue. Compared with frozen dehydrated specimen, the hydrated unfixed tissue tends to preserve more potassium and less chlorine. Cytochemical reaction product of succinate dehydrogenase (SDH-ase) activity in isolated mitochondria from rat liver was detectable in hydrated condition. Quick and easy assessment of localized elements in surgical specimens by combination of wet-SEM and X-ray microanalysis will be a new tool for clinical application of SEM. In spite of obvious limitations of this method, especially of its spatial resolution both in backscattered electron image and in bulk specimen X-ray microanalysis, the combination of wet-SEM and X-ray microanalysis provides information which has not been available in the past.

Animals↗
PubMed1983

Quantitative x-ray microanalysis of the elemental composition of individual myocytes in hypoxic rabbit myocardium.

The purpose of this study was to use energy dispersive x-ray microanalysis to test the following hypotheses: (1) that individual myocytes may exhibit important variation in the severity of alterations in intracellular ionic homeostasis in response to hypoxia and (2) that hypoxic myocytes may accumulate certain elements in quantities sufficient to impair organellar function and structure. A rabbit interventricular septal preparation with attached small right ventricular papillary muscles was used to obtain control oxygenated myocardium (six papillary muscles) and myocardium rendered hypoxic for 1 to 1 1/2 hr (n = 8). Myocardium not perfused in vitro was also obtained (n = 4). Microanalysis was performed on freeze-dried thin sections of unfixed papillary muscles. Elemental concentrations were determined by suitable cryostandards of elements of interest. Sarcoplasm and mitochondria of most hypoxic myocytes exhibited significant alterations of diffusible elements, including increases in sodium and chloride and decreases in potassium, phosphorus, and magnesium, without major change in calcium. The most severely altered myocytes showed evidence of calcium overloading manifested by markedly increased levels of mitochondrial calcium and phosphorus associated with formation of electron-dense mitochondrial inclusions. Levels of mitochondrial calcium and phosphorus exceeded those previously found to markedly impair the function and structure of isolated mitochondria. Thus x-ray microanalysis of unfixed cryosections provides direct measurements of subcellular alterations in elemental composition of individual myocytes in injured myocardium and demonstrates that both calcium and phosphorus accumulate in mitochondria of severely injured myocytes in concentrations sufficient to exert deleterious effects on these organelles.

Animals↗