Elemental analysis of occupational and environmental lung diseases by electron probe microanalyzer with wavelength dispersive spectrometer.

Occupational and environmental lung diseases are a group of pulmonary disorders caused by inhalation of harmful particles, mists, vapors or gases. Mineralogical analysis is not generally required in the diagnosis of most cases of these diseases. Apart from minerals that are encountered rarely or only in specific occupations, small quantities of mineral dusts are present in the healthy lung. As such when mineralogical analysis is required, quantitative or semi-quantitative methods must be employed. An electron probe microanalyzer with wavelength dispersive spectrometer (EPMA-WDS) enables analysis of human lung tissue for deposits of elements by both qualitative and semi-quantitative methods. Since 1993, we have analyzed 162 cases of suspected occupational and environmental lung diseases using an EPMA-WDS. Our institute has been accepting online requests for elemental analysis of lung tissue samples by EPMA-WDS since January 2011. Hard metal lung disease is an occupational interstitial lung disease that primarily affects workers exposed to the dust of tungsten carbide. The characteristic pathological findings of the disease are giant cell interstitial pneumonia (GIP) with centrilobular fibrosis, surrounded by mild alveolitis with giant cells within the alveolar space. EPMA-WDS analysis of biopsied lung tissue from patients with GIP has demonstrated that tungsten and/or cobalt is distributed in the giant cells and centrilobular fibrosing lesion in GIP. Pneumoconiosis, caused by amorphous silica, and acute interstitial pneumonia, associated with the giant tsunami, were also elementally analyzed by EPMA-WDS. The results suggest that commonly found elements, such as silicon, aluminum, and iron, may cause occupational and environmental lung diseases.

X-ray microanalysis in the scanning electron microscope.

X-ray microanalysis conducted using the scanning electron microscope is a technique that allows the determination of chemical elements in bulk or semithick specimens. The lowest concentration of an element that can be detected is in the order of a few mmol/kg or a few hundred parts per million, and the smallest amount is in the order of 10(-18) g. The spatial resolution of the analysis depends on the thickness of the specimen. For biological specimen analysis, care must be taken to prevent displacement/loss of the element of interest (usually ions). Protocols are presented for the processing of frozen-hydrated and freeze-dried specimens, as well as for the analysis of small volumes of fluid, cell cultures and other specimens. Aspects of qualitative and quantitative analysis are covered, including limitations of the technique.

The efficiency of X-ray microanalysis in low-vacuum scanning electron microscope: deposition of calcium on the surface of implanted hydrogel intraocular lens (IOL).

To examine the calcification of implanted hydrogel IOL by X-ray microanalysis, we compared conventional transmission electron microscopy (TEM) with low-vacuum scanning electron microscopy (SEM). We also compared metal coating with non metal coating in low-vacuum SEM. Calcification of IOL showed deposits which were located in the superficial substance of lens. In conventional TEM and X-ray microanalysis, calcium, phosphate and silicon were detected in the deposits. In low-vacuum SEM, the deposits detected in metal coating were calcium, phosphorus, sodium and magnesium, but not silicon. However, in non metal coating, the deposits contained not only calcium, phosphorus, silicon, sodium and magnesium, but also fluoride, aluminum and argentums. It was concluded that in conventional TEM where a specimen is fixed and dehydrated in ethanol, various elements leak out. On the other hand, when a specimen is coated with carbon and gold palladium for SEM, light elements might not be detected in X-ray microanalysis. Low-vacuum SEM preparation does not need metal coating and low-vacuum SEM appears to provide a highly efficient method for X-ray microanalysis.

Hard X-ray microprobe studies of chromium(VI)-treated V79 Chinese hamster lung cells: intracellular mapping of the biotransformation products of a chromium carcinogen.

The uptake of carcinogenic and mutagenic Cr compounds and the intracellular distribution of their biotransformation products in V79 Chinese hamster lung cells were studied by synchrotron-radiation-induced X-ray emission (SRIXE). SRIXE analysis was performed on whole cells that had been treated with either Cr(III) or Cr(V) 1,10-phenanthroline complexes, or Cr(VI). The high spatial resolution (0.3 microm) and elemental sensitivity (~10(-15) g Cr/cell) of the technique provided detailed maps of Cr and other cellular elements in thin sections prepared from Cr(VI)-treated cells. The Cr carcinogen concentrated in P-rich regions corresponding to the nucleus, as well as other areas of the cell that are likely to correspond to organelles. This is the first study that has enabled the determination of the localization of the biotransformation products of Cr(VI) carcinogens in a target lung cell.

Quantitative detection of silicone in skin by means of electron spectroscopy for chemical analysis (ESCA).

BACKGROUND: Evaluation of silicone-induced morbidity in skin has been hampered by the difficulty of detecting silicone in tissue because conventional methods are nonquantitative and insensitive. OBJECTIVE: We attempted to determine whether silicone could be identified and quantitated in skin by means of electron spectroscopy for chemical analysis (ESCA). METHODS: Skin biopsy specimens were obtained from the nose, chin, malar region, and inner arm of a patient who had received injections of silicone gel in his nose and chin. Frozen sections were dried under vacuum and examined by means of ESCA. Contiguous sections were examined by light microscopy. RESULTS: The surface concentrations of silicone were as follows: chin, 20.6% +/- 3.6%; nose, 19.0%; malar region, 2.6% +/- 1.6%; inner arm, 0.0% +/- 0.0%. Light microscopy revealed homogeneous "globules" consistent with silicone in the chin and nose sections only; the malar region and inner arm sections showed no evidence of silicone. CONCLUSION: ESCA can be used to detect silicone in skin in a specific, highly sensitive, and quantitative manner. This is the first report of quantification of silicone in skin by means of ESCA.

Coronary artery disease: improved reproducibility of calcium scoring with an electron-beam CT volumetric method.

PURPOSE: To assess the variability and reproducibility of a volumetric calcium score calculated with electron-bean computed tomographic (CT) scans of coronary arteries. MATERIALS AND METHODS: Two sets of electron-beam CT scans were obtained in patients with coronary calcification (group A) or known risk factors for coronary arterial disease (group B). The second set or scans was obtained after a brief interval (group A, n = 52) or after 1 year with no risk modification (group B, n = 27). Traditional (plaque area and attenuation) and volumetric calcium scores were calculated for each patient and lesion. RESULTS: The median percentage change for individual lesions in group A was 13% for the volumetric and 19% for the traditional score. The overall reduction in error with the volumetric score was 40% (P < .001). The median percentage change for group A patient totals was 9% for the volumetric and 15% for the traditional score (P < .001). In group B patients, the median volumetric score increased by 44% after 1 year. CONCLUSION: The volumetric score showed better reproducibility than the traditional score, and its variability was considerably less than the score increase in untreated patients after 1 year. The reproducibility of the volumetric method makes it useful for assessing the progression of coronary arterial disease on serial electron-beam CT studies.

Coronary artery calcium: alternate methods for accurate and reproducible quantitation.

RATIONALE AND OBJECTIVES: The aim of this study was to determine a more precise and accurate method of quantitating coronary artery calcium (CAC) detected with electron-beam computed tomography (CT) in patients with low CAC scores. MATERIALS AND METHODS: Two 40-section, 3-mm-collimation, electrocardiographically gated electron-beam CT examinations of the heart were performed in each patient. Fifty patients with average scores between 2 and 100, as determined with the conventional scoring algorithm, were selected. The modified conventional scoring algorithm was compared with two techniques: calculated calcium volume and approximated calcium mass. RESULTS: The percentage difference between scans ranged from 37.2% for the conventional scoring method to 28.2% and 28.4% for volume- and mass-based methods, respectively. Increasing lesion size thresholds does not improve quantitative precision and reduces accuracy in patients with small amounts of CAC. CONCLUSION: Quantification methods based on calcification volume or mass decrease score variation compared with the conventional scoring method, and increased size threshold does not improve accuracy.

An X-ray microprobe facility using synchrotron radiation.

An X-ray microprobe for trace elemental analysis at micrometer spatial resolutions, using synchrotron radiation (SR), is under development. The facility consists of two beamlines, one including a 1:1 focusing mirror and the other an 8:1 ellipsoidal mirror. At present, "white light" is used for excitation of the characteristic X-ray fluorescence lines. Sensitivities in thin biological samples are in the range of 2-20 fg in 100 microns2 areas in 5 min irradiation times. Scanning techniques, as well as microtomography and chemical speciation, are discussed. Application to a specific biomedical study is included.

Improved vacuum evaporation unit for beryllium coating for biological X-ray microanalysis.

An improved vacuum evaporator is described for coating frozen-hydrated biological samples with beryllium for X-ray microanalysis. The evaporator permits repeated coatings without bringing the main chamber to atmospheric pressure and ambient temperature. The use of a glass sleeve in the evaporation chamber facilitates cleaning.

Microanalysis in biology and medicine: ultrastructural localization of aluminum.

Four methods for the ultrastructural tracing of elements in man and animal are discussed. In addition to histochemical staining, emphasis was put on three innovative sophisticated microanalytical techniques: electron probe X-ray microanalysis, secondary ion mass spectrometry, and laser microprobe mass analysis. The principles and merits of these methods for microanalysis are reviewed. The application of these techniques for the detection of aluminum at the microscopic level is described in detail because of the clinical importance of this metal in severe chronic renal failure. A literature survey concerning the microanalysis of aluminum in biology and medicine is presented.

X-ray microanalysis: identification and quantification of elements in normal and pathologically altered cells.

It is apparent that advanced technology in X-ray microanalysis is rapidly becoming applicable to experimental cellular pathology. Additionally, it has already proven to be of significant value in diagnostic human pathology and clinical research, especially in the areas of environmental toxicology and forensic pathology. Like routine electron microscopy, X-ray microanalysis will soon be a necessary technology for any major medical center practicing 'state-of-the-art' medicine.

Combined analysis of kidney stones by X-ray diffraction and electron microprobe.

Oxalate, apatite, struvite, uric acid and cystine stones were routinely analysed by X-ray diffraction. A second analysis was performed by electron microprobe. The substances not detected by X-ray diffraction were apatite and struvite in oxalate and cystine stones. Oxalate was not found in uric acid stones because of insufficient routine sample preparation, but could be detected in a second X-ray analysis. Conclusions concerning the exact stone composition can only be reached after X-ray diffraction has been completed in conjunction with a second procedure, such as electron microprobe analysis. For clinical routine use X-ray diffraction is sufficient if adequate sample preparation is performed. The electron microprobe analysis provides further information about mixed phase formations (single or multiple layers, diffuse distributions etc.) and about inclusions in a phase, which have some clinical consequences.

Secondary ion mass microanalysis: applications in biology.

"Secondary ion emission analysis", a method of surface microanalysis proposed in 1960 by Castaing and Slodzian, has been applied to the study of biological tissues by several groups in Europe and United States. Compared to X-ray or electron energy loss analysis, the main advantage of this method as applied in biological research is its very high sensitivity which makes it possible to easily obtain images distribution of many nuclides in a tissue section even when the concentration of these nuclides is very low (0.1 ppm or less). On the other hand, the spatial resolution is not better than 0.5 micron and observation of the specimen at the ultrastructural level is not yet possible. Another disadvantage of this method is the difficulty to obtain quantitative data. Thus, in the present state of the art, the typical field of research where the biologist can take advantage of Secondary Ion Mass Microanalysis (SIMM) is the qualitative chemical and isotopic analysis of elements at a low concentration in a cellular volume of the order of 1 micron 3.