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Results for “Electron Probe Microanalysis”

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PubMedDate not supplied

[Indoor pollution from airborne glass fibers in biomedical research laboratories].

It is known that the presence of fibers in indoor environment is able to lead to irritative symptoms of skin and mucous membranes. Such troubles have been repeatedly claimed by workers in biomedical research laboratories of our University. For this reason, an investigation for the evaluation of the risk and for propose preventional solutions has been performed (also for absolve fully to D.Lgs. 626/94). On account of the environmental investigations has been revealed the presence of rock wool fibers-included in a water lime matrix-sprayed in big quantity on the ceilings. Therefore, the phases and the methods followed for the analysis of the risks are showed together with evaluations in order to the preventional interventions, also on the basis of what has been established by the lawgiver.

Air Pollution, Indoor↗
PubMed2003

Localization of Hg and Pb in the palps, the digestive gland and the gills in Mytilus galloprovincialis (L.) using autometallography and X-ray microanalysis.

The intracellular localization of heavy metals using autometallography (AMG) and X-ray microanalysis was studied in the palps, the digestive gland and the gills of mussels Mytilus galloprovincialis, after an experimental exposure to 0.1 mg l(-1) of Hg and 0.1 mg l(-1) of Pb, for 30 and 60 days. In the examined tissues, autometallographical black silver deposits (BSD) were localized mainly in the residual bodies and heterolysosomes of the digestive cells, as well as in the dense bodies of the epithelial cells. Metal deposition after Hg exposure was much more abundant compared to Pb exposure. Using X-ray microanalysis, Hg was traced on the BSD in all examined tissues, while Pb was not traced in these deposits. The results are discussed in comparison to previous results on long-term exposure to the same metals; in addition, the palps are introduced as a new metal storing organ and, finally, the use of X-ray microanalysis under a scanning electron microscope in order to enhance the specificity of AMG is suggested.

Animals↗
PubMed1994

FNA of extraskeletal myxoid chondrosarcoma: cytomorphologic, EM, and X-ray microanalysis features.

Extraskeletal myxoid chondrosarcoma, an unusual soft tissue lesion which preferentially affects the extremities, is a prime candidate for "pathologist performed" fine-needle aspirates (FNA) because it preferentially affects the extremities [Enzinger and Shiraki, Hum Pathol 1972;3:421-435] and is usually an accessible lesion. Cytomorphologically, the neoplasm consists of clusters of fairly uniform cells, lacking cartilaginous differentiation, with a metachromatic matrix when stained with Diff-Quik (DQ). While subtle, this neoplasm has distinct features and must be distinguished for other neoplasms in the differential diagnosis because patient evaluation, prognosis, and therapy will vary greatly. We present a case characteristic of this tumor in which FNA derived material was subjected to light microscopy, X-ray microanalysis, and immunohistochemical studies; each modality provided data essential to the correct diagnosis.

Aged↗
PubMed1997

Direct evidence for uptake of intact liposomes encapsulating silver sulfadiazine by cultured human keratinocytes based on combined transmission electron microscopy and X-ray microanalysis.

Cultured human keratinocytes were exposed to liposomally encapsulated silver sulfadiazine, free silver sulfadiazine, silver sulfadiazine cream, and a corresponding vehicle for 5 min to 24 h. Phagocytosis of intact liposomes by keratinocytes was demonstrated in vitro by combined X-ray microanalysis and electron microscopy. Silver as an active part of the antimicrobial served as an electron-dense marker.

Anti-Infective Agents, Local↗
PubMed1984

Some recent experience with the scanning electron microscope in corrosion research.

Corrosion and oxidation are the results of chemical reaction between a solid surface (such as of a metal or alloy) and its environment, to form a corrosion product. The product may adhere to the surface, thereby usually providing some protection from further attack, or may be removed from it (e.g. by volatilization or by dissolution in the environment). In either case this leads to changes in topography, morphology and, often, composition of the surface. Study of such changes can provide considerable information and assistance in the determination of the mechanisms of degradation. Scanning electron microscopy with associated microanalysis has thus enabled significant advances to be made in understanding many corrosion and oxidation processes. The progress attained in several areas where the technique has played a major part but has been extended to its maximum capabilities is discussed and related to the particular advantages and limitations of scanning electron microscopy in this field. One such area is the study of high-temperature corrosion processes. Here, the high resolution and depth of focus of the instrument have provided detailed information on the microstructure of high-temperature oxide and other corrosion-product scales and underlying alloy. For instance, the sizes and distributions of pores in the scales give important insight into the possibility of growth mechanisms involving gas-phase transport within the scales themselves. Associated microanalysis can assist in identification of rate-determining layers and of other localized diffusion paths which can short-circuit bulk lattice diffusion.

Alloys↗
PubMed2002

Detection of aluminium by energy dispersive X-ray microanalysis at high accelerating voltages with semi-thin sections of biological sample.

Aluminium (Al) was detected in semi-thin sections of three organs, the duodenum, liver and kidney, of ddY strain mouse by energy dispersive X-ray microanalysis at high accelerating voltages around 300 kV. Firstly, to determine the conditions best for detecting Al, several adult ddY mice were injected intraperitoneally with aluminium chloride (AlCl3) and the duodenums were fixed, embedded and sectioned at various thicknesses and subjected to energy dispersive X-ray microanalysis at various accelerating voltages from 100 to 400 kV. From the results obtained, 1.0 microm-thick sections observed at 300 kV resulted in the highest peak-counts/background ratios and were shown to be the most suitable for X-ray microanalysis. Secondly, ddY mice aged four weeks were administered orally with 2% AlCl3 at pH 2.5 for two weeks and the three organs (duodenum, liver and kidney) were subjected to X-ray microanalysis under the same condition found above. The results were compared with light microscopic Al staining of the same tissues. Aluminium was detected in lysosomes of the three kinds of tissues with higher sensitivity by energy dispersive X-ray microanalysis by light microscopic observation. From the results, it was suggested that Al dissolved in acidic water was absorbed in the duodenum and accumulated in the liver and kidney.

Aluminum↗
PubMed1979

Principles of X-ray microanalysis in biology.

Progress in biological X-ray microanalysis has been limited in recent years by specimen preparation procedures. Instrumentation and high levels of sensitivity for low concentrations are well developed for a large number of biological applications but reliable preparation of samples in the thick or thin form has yet to be establisehd. In addition the possible damage of specimens by the electron probe has been incompletely studied in the majority of applications. In this review the basic principles of X-ray production, design and operation of X-ray detectors, quantitative procedures for thick and thin samples, analytical operation of the microscope, and current specimen preparation techniques are briefly described with the aim of highlighting weaknesses and discussing recent developments in each field.

Animals↗
PubMed1979

Distribution of corrosion products in teeth restored with metal crowns retained by stainless steel posts.

The nature and distribution of corrosion products in teeth restored with metal crowns retained by stainless steel posts were examined by means of energy-dispersive X-ray microanalysis, microradiography, and electron microscopy. The corrosion products consisted of calcium, phosphorous, iron, chromium, nickel, zinc, stannum and other elements. A possible root fracturing mechanism is discussed.

Corrosion↗
PubMed1987

Distribution of iron in pig placenta (Sus scrofa dom. L.).

Iron distribution was studied in pig placentae between 21 day till the end of pregnancy (113) with the use of histochemical and cytochemical methods and X-ray microanalysis. Iron content was measured in fetal and maternal part of the placenta with chemical methods. Iron presence was confirmed in maternal and fetal erythrocytes, cells and secretion of uterine glands and trace amount in trophoblast lining regular areolae. No significant differences were found in iron content in fetal and maternal part of the placenta throughout the entire studied period. With the applied histochemical method of iron determination according to Perls, potassium ferrocyanide also adsorbs in sites where mucopolysaccharides are present, in which iron presence has not been detected with the use of X-ray microanalysis.

Animals↗
PubMed2000

The skin barrier: analysis of physiologically important elements and trace elements.

Changes in the properties of the skin barrier should have correlates in the physiological status of the differentiating epidermal cells. However, the quantitative distributions of physiologically important elements and trace elements of the skin has been a neglected area of research for lack of tools to investigate this highly differentiated tissue. With the event of the particle probes, the electron microprobe and the scanning proton microprobe, it has become possible to investigate different aspects of normal skin physiology as well as pathophysiological processes. In addition penetration profiles of allergenic metals can be demonstrated with the trace element sensitive proton probe. Future approaches to the study of skin physiology in normal and pathological conditions should incorporate other techniques including immunological and biochemical tagging of particular cells to achieve a broad basis for interpretations of data.

Allergens↗
PubMedDate not supplied

A quantitative cryo-scanning X-ray microanalysis protocol for the examination of the eye.

Analysis of elements present in fluids contained in small, poorly accessible sections of biological tissue is challenging. The choroid of the eye, which is a vascular tissue approximately 100 microm thick, surrounds the retina for the purposes of nutrient supply and metabolite removal, and which in the chick shows dramatic volumetric change in response to visual experiences. Because fluid homeostasis is critical to good vision, a complete understanding of the ionic changes driving large shifts in ocular fluids is required. However, the structure of the choroid and retina make extraction of pure fluids for analysis extremely difficult. Elemental x-ray analysis on a transverse chorioretinal specimen was performed after rapid freezing of a whole chick eye in liquid nitrogen, and mechanically fracturing the frozen globe. Using a Polaron Cryotrans System on a Cambridge S-360 scanning electron microscope and a Kevex Quantum detector, spectra were obtained for blood vessels, lymphatic vessels and vitreous that were readily visible at 265x. Analysis was performed on a frozen control solution of the elements found in the vessels. The elements and their concentrations found in blood vessels by x-ray analysis compared well with those from whole blood as established by conventional means. The analysis for lymph yielded results compatible with expectations; no other published data for small lymphatics enable a direct comparison. In conclusion, x-ray analysis can be used to acquire information that is otherwise unobtainable from tissue in situ. The same bulk-frozen elemental microanalysis protocol would have application to other organs and tissues when access to the site would destroy the integrity of the tissue under investigation.

Animals↗
PubMed1996

Heterogeneous ultrastructure of melanosome formation in the goldfish induced by osmotic stress.

In this study, melanophore cytodifferentiation in the fins of xanthic goldfish that had been exposed to osmotic stress for 18 days was investigated. It was found that multi-vesicular bodies (MVB) are not the only type of premelanosome. Granules having a homogeneous matrix also function as premelanosomes. The presence of acid phosphatase reaction product inside the melanin granules indicated that these organelles in this animal were also related to lysosomes. DOPA-oxidase of tyrosinase, the key enzyme in melanogenesis, was surprisingly not only detected in melanocytes but also in the Golgi stacks of dermal cells. Due to the mechanisms of premelanosome formation it is evident that cytoplasmic material also serves as substrate for melanogenesis. EDX microanalysis was performed to measure the ionic composition of the melanin granules. After aldehyde fixation the newly-formed melanin granules did not contain Na, but had accumulated Ca.

Acid Phosphatase↗
PubMed1979

Mucosubstances of rabbit granulocytes studied by means of electron-microscopic radioautography and X-ray microanalysis.

Rabbit bone marrow cells have been studied by means of light- and electron-microscopic radioautography and X-ray microanalysis. Carrier free sulfuric acid was used as the radioactive precursor in this experiment. Immature granulocytes showed more active incorporation than mature ones. Silver grains were observed in the Golgi apparatus and granules in three kinds of granulocytes. Electron-microscopically, immature granules showed the incorporation of inorganic sulfate, while mature ones did not. Sulfur was detected in all kinds of granules of the three granulocyte types by X-ray microanalysis. It is concluded that incorporated inorganic sulfur may be utilized for the synthesis of acid glycosaminoglycans and the sulfur detected by X-ray microanalysis may be that contained in the acid glycosaminoglycan. The sulfur detected in the specific granules of the heterophil probably derives from proteins or polypeptides incorporating sulfur containing amino acids.

Animals↗