CLINICOPATHOLOGIC conference.
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Beryllium↗
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Results for “BERYLLIUM OXIDE”
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Measurement of beryllium in biological samples by accelerator mass spectrometry: applications for studying chronic beryllium disease.
A method using accelerator mass spectrometry (AMS) has been developed for quantifying attomoles of beryllium (Be) in biological samples. This method provides the sensitivity to trace Be in biological samples at very low doses with the purpose of identifying the molecular targets involved in chronic beryllium disease. Proof of the method was tested by administering 0.001, 0.05, 0.5, and 5.0 microg of 9Be and 10Be by intraperitoneal injection to male mice and removing the spleen, liver, femurs, blood, lungs, and kidneys after 24 h of exposure. These samples were prepared for AMS analysis by tissue digestion in nitric acid, followed by further organic oxidation with hydrogen peroxide and ammonium persulfate and, last, precipitation of Be with ammonium hydroxide and conversion to beryllium oxide at 800 degrees C. The 10Be/9Be ratio of the extracted beryllium oxide was measured by AMS, and Be in the original sample was calculated. Results indicate that Be levels were dose-dependent in all tissues and the highest levels were measured in the spleen and liver. The measured 10Be/9Be ratios spanned 4 orders of magnitude, from 10(-10) to 10(-14), with a detection limit of 3.0 x 10(-14), which is equivalent to 0.8 amol of 10Be. These results show that routine quantification of nanogram levels of Be in tissues is possible and that AMS is a sensitive method that can be used in biological studies to understand the molecular dosimetry of Be and mechanisms of toxicity.
Animals↗
Risks of beryllium disease related to work processes at a metal, alloy, and oxide production plant.
OBJECTIVES: To describe relative hazards in sectors of the beryllium industry, risk factors of beryllium disease and sensitisation related to work process were sought in a beryllium manufacturing plant producing pure metal, oxide, alloys, and ceramics. METHODS: All 646 active employees were interviewed; beryllium sensitisation was ascertained with the beryllium lymphocyte proliferation blood test on 627 employees; clinical evaluation and bronchoscopy were offered to people with abnormal test results; and industrial hygiene measurements related to work processes taken in 1984-93 were reviewed. RESULTS: 59 employees (9.4%) had abnormal blood tests, 47 of whom underwent bronchoscopy. 24 new cases of beryllium disease were identified, resulting in a beryllium disease prevalence of 4.6%, including five known cases (29/632). Employees who had worked in ceramics had the highest prevalence of beryllium disease (9.0%). Employees in the pebble plant (producing beryllium metal) who had been employed after 1983 also had increased risk, with a prevalence of beryllium disease of 6.4%, compared with 1.3% of other workers hired in the same period, and a prevalence of abnormal blood tests of 19.2%. Logistic regression modelling confirmed these two risk factors for beryllium disease related to work processes and the dependence on time of the risk at the pebble plant. The pebble plant was not associated with the highest gravimetric industrial hygiene measurements available since 1984. CONCLUSION: Further characterisation of exposures in beryllium metal production may be important to understanding how beryllium exposures confer high contemporary risk of beryllium disease.
Adult↗
[The bonding mechanisms of base metals for metal-ceramic crown microstructure analysis of bonding agent and gold bond between porcelain and base metals].
The use of base metal alloys for porcelain fused to a metal crown and bridges has increased recently because of lower price, high hardness, high tensile strength and high elastic modulus. The addition of beryllium to base metal alloys increased fluidity and improved casting fitness. Beryllium also controlled surface oxidation and bonding strength. The bonding agent and gold bonding agent also affected the bonding strength between porcelain and metal alloys. Four commercially available ceramic base alloys were studied (two alloys contained beryllium element, another two did not). The purpose of this investigation was to study the microstructure between porcelain matrix, bonding agent and alloy matrix interfaces. A scanning electron micro-probe analyzer and energy dispersive X-ray spectroscopy (EDXS) were used to study the distribution of elements (Ni, Cr, Mo, Cu, O, Si, Sn, Al) in four base alloys. The following results were obtained: 1. The thickness of the oxidized layer of Rexillium III alloy and Unitbond alloy (contained beryllium) was thinner than Unibond alloy and Wiron 88 alloy (no beryllium). 2. The thickness of the oxidized layer of alloys in air (10 minutes and 30 minutes) was thinner in Unitbond (2.45 microns and 3.80 microns) and thicker in Wiron 88 (4.39 microns and 5.96 microns). 3. The thickness of the oxidized layer occurring for a duration of ten minutes (in vaccum) showed that the Rexillium III alloy was the thinnest (1.93 microns), and Wiron 88 alloy was the thickest (2.30 microns). But in thirty minutes (vacuum), Unitbond alloy was the thinnest (3.37 microns), and Wiron 88 alloy was the thickest (5.51 microns). 4. The intensity of Cr elements was increased obviously near the interface between Unitbond alloy, Wiron 88 alloy (no beryllium) and oxidized layer, but the intensity of Ni and Mo elements was slightly increased. The intensity of Cr element was not increased markedly between Rexillium III alloy, Unitbond alloy (beryllium) and oxidized layer. 5. A white-grayish oxidized layer appeared at the metal-ceramic interfaces but the thickness of oxidized layer was not obviously different. 6. The use of bonding agent at metal-ceramic interface leads to the deposition of many Sn elements at about 40 microns range within the porcelain surface. 7. Second interaction phases at the porcelain layer appeared when gold bonding agent was used, and a 50-100 microns microleakage occurred at the metal-ceramic interface.
Dental Bonding↗
[Oxidation processes in the lungs of rats following poisoning by beryllium compounds].
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Animals↗
Current Perspectives on Occupational Cancer Risks.
On the basis of the International Agency for Research on Cancer's evaluations of occupational exposures, 22 occupational agents are classified as human carcinogens and an additional 22 agents as probable human carcinogens. In addition, evidence of increased risk of cancer was associated with particular industries and occupations, although no specific agents could be identified as etiologic factors. The main problem in the construction and interpretation of such lists is the lack of detailed qualitative and quantitative knowledge about exposures to known or suspected carcinogens. The recent examples of recognized occupational carcinogens, such as cadmium, beryllium, and ethylene oxide, stress the importance of the refinement in the methods for exposure assessment and for statistical analysis on the one hand and the potential benefits from the application of biomarkers of exposure and early effect on the other hand. Other trends that may be identified include the increasing practice of multicentric studies and investigations of exposures relevant to white collar workers and women. Finally, there is a need for investigation of occupational cancer risks in developing countries.
Journal Article↗
[The shear bond strength of porcelain and base metal alloys for metal-ceramic crown the study of metal roughness and microstructure].
The metal-ceramic crown has become a predominant restoration in fixed prosthodontics. The base metal has the quality of lower price, high tensile strength, high elastic modulus. The base metal alloy that contain beryllium element increases fluidity and improved casting performance. Beryllium also controls surface oxidation and affects the metal ceramic bonds. Preparation of surface prior to porcelain bonding has been a subject of controversy among dental ceramists. Two ceramic base metal alloys (one alloy contains beryllium, another is not) were studied. This investigation evaluated the polishing effects of 50 microns, 100 microns aluminum oxide sandblasting, carbide bur, carborundum point and separating disk upon two base metal alloys, Rexillium III and Wiron 88. A scanning electron microscope was used to study the surface texture. The following results were obtained: 1. The most roughest surface was created with 50 microns aluminum oxide sandblasting. The carbide bur produced the least roughed surface. 2. There are specific surface texture patterns after polishing with five different grinding materials. 3. The metal surfaces treated with 50 microns and 100 microns aluminum oxide have same micro-structure pictures, but there are much more undercuts treated with 100 microns aluminum oxide. 4. The usage of carbide bur resulted in less undercuts of metal surface at two metal alloys. 5. The usage of carborundum point and disk resulted in abrasive particles that retained on the grinding metal surface at two metal alloys. 6. The surface of Wiron 88 alloy usually had wrinkle texture but not the Rexillium III alloy.
Crowns↗
[The shear bond strength of porcelain and base metal alloys for metal-ceramic crown (VI)].
The popularity of base metal alloy for porcelain fused to a metal crown and bridges has increased recently because of lower price, superior yield strength and modulus of elasticity (rigidity). The use of these alloys give them the potential advantage of thinner coping with less material and the required rigidity for long-span fixed partial dentures. The addition of beryllium to base metal alloys increases fluidity and improves casting fit. Beryllium also controls surface oxidation and bonding strength. Oxidation heat treatment of the metal is used to remove entrapped air, eliminate organic material and form the metal oxidized layer. The bonding agent and gold bonding agent also affect the bonding strength between porcelain and metal alloys. Four commercially available ceramic base alloys (two alloys contain beryllium element, another two do not) are studied. The purposes of this investigation are to test the shear bond strength between porcelain and metal alloy under different conditions (oxidized layer removed or not, gold bonding agent and uniseal bonding agent used in combination, separately or not at all). The following results were obtained: 1. Whether the oxidized layer was removed or not did not have a significant effect on the bond strength of porcelain (p > 0.05). 2. When different metal alloys was used, Wiron 88 alloy showed significantly the best bond strength of all alloys tested (p < 0.05). 3. When different bonding agent were used, the combination of bonding agent and gold bonding agent showed the best bond strength of all bonding agents tested. It showed a significantly higher bonding strength than opaque layer and gold bonding agent. 4. Vita porcelain powder showed a significantly higher bond strength than did Unibond porcelain (p < 0.05). 5. When opaque layer was used and when no bonding agent was used, the porcelain powder significantly affected the bond strength (p < 0.0001). The Vita porcelain showed a significantly higher bond strength than did Unibond porcelain. Wiron 88 alloy showed significantly the high bond strength than Rexillium III alloy (p < 0.05). 6. When bonding agent was used, the porcelain powder and alloy significantly affected bond strength. The Vita porcelian showed a significantly higher bond strength than did Unibond porcelain. Wiron 88 alloy showed significantly the best bond strength than other alloys Wiron (p < 0.05). 7. When bonding agent and gold bonding agent were used, the porcelain powder significantly affected the bond strength (p < 0.05). The Vita porcelain showed a significantly higher bond strength than did Unibond porcelain (p < 0.05). 8. When gold bonding agent was used, there was not any bond strength between metal and powder.
Crowns↗
[The effect of magnesium on the process of oxidation in rat liver and lung homogenates in experimental beryllium poisoning].
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Animals↗
Role of the Alexandrite laser for removal of tattoos.
BACKGROUND AND OBJECTIVE: The development of the Alexandrite laser for the removal of blue-black tattoos is described. STUDY DESIGN/MATERIALS AND METHODS: The responses of an animal study, using professionally tattooed skin and a human study involving 22 (professional and nonprofessional) blue-black tattoos, to the Alexandrite laser are reported. RESULTS: Histopathologic evaluation of tattooed pig skin biopsies demonstrated the method of removal of dermal tattoo pigment. An average 11.6 treatments were required to remove completely the ten human blue-black professional tattoos compared to an average of 10.3 treatments to reach the same endpoint in six subjects with nonprofessional tattoos. CONCLUSION: Of significance was the fact that unlike the Q-switched Ruby and Nd:YAG lasers where punctate bleeding and tissue splattering have been reported to occur during laser tattoo removal, epidermal integrity was maintained during exposure of tattooed skin to the Q-switched Alexandrite laser at therapeutic fluences used.
Adult↗
Bank of calibrated BeO ceramic dosimeters for TSEE and TL.
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Beryllium↗
Immobilisation of beryllium in solid waste (red-mud) by fixation and vitrification.
The objective of this study was to obtain information on the immobilization of beryllium (Be) in solid waste generated in the extraction process of beryllium from its ore, Beryl. This solid waste, termed red-mud, contains oxides of iron, aluminium, calcium, magnesium and beryllium. The red-mud waste contains beryllium at levels above the permissible limit, which prevents its disposal as solid waste. The total beryllium content in the red-mud analysed showed value ranging from 0.39 to 0.59% Be The studies showed that 50% of the total beryllium in red-mud can be extracted by water by repeated leaching over a period of 45 days. The cement mix, casting into cement blocks, was subjected to leachability studies over a period of 105 days and immobilization factor (IF factor) was determined. These IF values, of the order of 102, were compared with those obtained by performing leachability study on vitrified red-mud masses produced at different temperature conditions. Direct heating of the red-mud gave the gray coloured, non-transparent vitreous mass (as 'bad glass') showed effective immobilisation factor for beryllium in red-mud of the order of 10(4).
Beryllium↗
Modulation of alpha 4 beta 1 and alpha 5 beta 1 integrin expression: heterogeneous effects of Q-switched ruby, Nd:YAG, and alexandrite lasers on melanoma cells in vitro.
BACKGROUND AND OBJECTIVE: Integrins of the beta 1 family are cellular adhesion molecules that play an important role in cell attachment and migration by interacting with extracellular matrix molecules. Agents such as hormones, cytokines, and ultraviolet radiation have all been shown to have an integrin modulating potential. The present study indicates that radiation of Q-switched lasers is also able to induce transient changes in integrin expression levels on human melanoma cells in vitro. STUDY DESIGN/MATERIALS AND METHODS: Radiation from Q-switched Ruby (694 nm), Alexandrite (755 nm), and Nd:YAG laser (1,064 nm) with fluences comparable to those that are generally used in treating dermatologic lesions were used to irradiate a subconfluent layer of human melanoma cells. After fixed time intervals, the cells were harvested either to analyse the integrin expression by flow cytometry or to investigate changes in cell attachment, spreading, and migration. RESULTS: It was established that all three types of laser were able to cause a significant downregulation of both the alpha 4 and the common beta 1 integrin subunit. The Alexandrite and Ruby lasers also induced a decrease in alpha 5 expression; however, the cells treated with the Nd:YAG laser showed a marked upregulation of the alpha 5 subunit. The expression of the other beta 1 integrin subunits was shown to be unaltered after laser treatment. Downregulation of the alpha 4 upregulation of the alpha 5 integrin subunit expression resulted in, respectively, decreased and increased attachment and spreading on fibronectin, the extracellular matrix ligand for both the alpha 4 beta 1 and alpha 5 beta 1 integrins. Marked upregulation of the alpha 5 subunit also resulted in a higher migration rate. CONCLUSION: Taken together, these results show that nonlethal doses of Q-switched laser radiation are able to induce changes in cellular behavior in vitro by modulating the integrin expression pattern.
Aluminum Oxide↗
Use of the alexandrite laser (755 nm, 100 nsec) for tattoo pigment removal in an animal model.
BACKGROUND: All previous treatment modalities for the removal of tattoos, with the possible exception of the Q-switched ruby and YAG lasers, result in scarring. OBJECTIVE: The purpose of this study was to investigate the use of a new laser that may remove tattoo pigment without leaving a scar. METHODS: A Yucatan micropig was tattooed by a professional tattoo artist with black, blue, green, and red pigments. These tattoos were then treated with single overlapping pulses with the alexandrite laser (wavelength 755 nm, pulse 100 nsec) and evaluated clinically and histologically. Comparison treatment with an argon laser (wavelength 488 nm, 514 nm, continuous-wave) and flashlamp-pumped dye laser (wavelength 585 nm, pulse 450 microseconds) was performed as well for removal of red tattoo pigment. RESULTS: The alexandrite laser was found to be very effective in removal of professional and amateur black tattoo pigment, moderately effective in removal of blue and green pigment, and minimally effective in removal of red pigment. No scarring was seen clinically or histologically. CONCLUSION: The alexandrite laser shows promise as a treatment modality for tattoo removal without scarring.
Aluminum Oxide↗
Raman microscopic study at 300 and 77 K of some pegmatite minerals from the Iveland-Evje area, Aust-Agder, Southern Norway.
The Raman spectra at 300 and 77 K of beryl, columbite-tantalite and topaz single crystals from pegmatites in the Iveland-Evje area are described in detail. The beryl is shown to contain mainly water type I and less of type II in its channels, while CO2 is only a very minor channel constituent. Cooling to 77 K results in minor shifts towards higher wavenumbers for most bands. The Si-O vibrations at 1009 and 1066 cm(-1) show a doubling to four bands at 1015, 1072, 1087 and 1149 cm(-1) due to structural rearrangements in the hexameric rings forming the channels in the beryl crystal structure. In addition a new band becomes visible around 1155 cm(-1). The tantalite could not be analysed in detail due to strong fluorescence. The Raman spectrum of the yellow topaz from Solås is comparable to that of the colourless topaz from Topaz Mountain, Thomas Range, Utah. Upon cooling to 77 K, two OH-stretching bands become visible around 3644 and 3655 cm(-1), which were not observed at room temperature.
Aluminum Silicates↗
[Ureteroscopic lithotripsy using the laser].
The Cagliari urology team is very satisfied with the use of the dye laser for ureteroscopic lithotripsy. This apparatus is recommended in units possessing a well equipped endourology room, otherwise it is simpler to use endoureteric ballistic lithotripsy, which also provides good results.
Aluminum Oxide↗
Toxicological effects of beryllium on platelets and vascular endothelium.
Although ample research has described the toxic effects of the metal beryllium on the respiratory apparatus, less is known about its effects on the vascular apparatus, including pulmonary blood vessels. We investigated the in vitro effects of beryllium on endothelial vascular adenosine diphosphatase activity and prostacyclin production in bovine aortic endothelium, and on nitric oxide release in isolated rabbit arteries. Rabbit and human platelet responsiveness was also evaluated. Beryllium inhibited vascular endothelial adenosine diphosphatase activity, prostacyclin production, and nitric oxide release, thus inducing functional alterations in vascular endothelial cells. It also induced platelet hyperreactivity to arachidonic acid, as shown by a lowering of the threshold of aggregating concentration and by concurrently increasing thromboxane production. In contrast, beryllium left the response to aggregating and nonaggregating concentrations of ADP and collagen unchanged. These findings show that beryllium may impair some vascular endothelial functions and alter the interaction between platelet and endothelial mediators.
Animals↗
Health hazards of welding fumes.
Even in the twenty-first century, welding is still a common and a highly skilled occupation. The hazardous agents associated with welding processes are acetylene, carbon monoxide, oxides of nitrogen, ozone, phosgene, tungsten, arsenic, beryllium, cadmium, chromium, cobalt, copper, iron, lead, manganese, nickel, silver, tin, and zinc. All welding processes involve the potential hazards for inhalation exposures that may lead to acute or chronic respiratory diseases. According to literature described earlier it has been suggested that welding fumes cause the lung function impairment, obstructive and restrictive lung disease, cough, dyspnea, rhinitis, asthma, pneumonitis, pneumoconiosis, carcinoma of the lungs. In addition, welding workers suffer from eye irritation, photokeratitis, cataract, skin irritation, erythema, pterygium, non-melanocytic skin cancer, malignant melanoma, reduced sperm count, motility and infertility. Most of the studies have been attempted previously to evaluate the effects of welding fumes. However, no collectively effort illuminating the general effects of welding fumes on different organs or systems or both in human has not been published. Therefore, the aim of this review is to gather the potential toxic effects of welding fumes documented by individual efforts and provide informations to community on hazards of welding.
Air Pollutants, Occupational↗