1.Compensation and Diagnosis of Asbestos Related Disease.
Korean Journal of Family Medicine 2009;30(5):335-343
Asbestos is a fibrous silicate that was widely used because of its heat resistance properties. Asbestos exposure affects workers involved in mining or processing asbestos or those involved in the use of asbestos in the shipbuilding, construction, and textile- and insulation-manufacturing industries. There are three commonly available types of asbestos; chrysotile (white asbestos), amosite (brown asbestos), and crocidolite (blue asbestos). All three have been associated with cancerous and non-cancerous lung disease. Asbestos-related diseases includes benign pleural effusion, pleural plaques, diffuse pleural thickening (a non-malignant disease affecting the lung lining), rounded atelectasis, asbestosis (a scarring of the lung tissue caused by asbestos), mesothelioma and lung cancer. Mesothelioma is a malignant pleural or peritoneal tumor that rarely occurs in patients who have not been exposed to asbestos. The latency period of most asbestos-related disease is 10 years or longer, asbestos-related disease remains an important public health issue. The clinical diagnosis of asbestos related diseases should be based on a detailed interview of the patient and occupational data on asbestos exposure, signs and symptoms, radiological and lung physiological findings and selected cytological, histological and other laboratory studies. Radiological imaging plays a pivotal role in the diagnosis and management of asbestos-related disease.
Asbestos
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Asbestos, Amosite
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Asbestos, Crocidolite
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Asbestos, Serpentine
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Asbestosis
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Cicatrix
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Compensation and Redress
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Hot Temperature
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Humans
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Latency Period (Psychology)
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Lung
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Lung Diseases
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Lung Neoplasms
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Mesothelioma
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Mining
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Pleural Effusion
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Public Health
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Pulmonary Atelectasis
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Silicates
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Workers' Compensation
2.Monitoring and analysis of asbestos concentration in working environment of different asbestos-producing technologies in a certain area.
Zhaoqiang JIANG ; Junqiang CHEN ; JianLin LOU ; Chao MIAO ; Dichu SHAO ; Xing ZHANG
Chinese Journal of Industrial Hygiene and Occupational Diseases 2015;33(11):833-837
OBJECTIVETo analyze asbestos exposure level between 1984 and 2010 in a district of malignant mesothelioma with clustering incidence in Zhejiang Province, in order to improve the recognizing and early diagnosis of malignant mesothelioma, protect the health of workers.
METHODSMonitoring data of total asbestos dust concentration in the air of workplace from 1984 to 2010 in asbestos textile enterprises, family hand spinning operation, brake production, and asbestos board production in Zhejiang Province were collected in the local CDC. A total of 766 TWA copies of mass concentration were collected, and 1233 copies of MAC data. Asbestos mass concentration and fibre counting concentration of 29 points of family hand spinning operation were parallel determinated in the same time and the same sampling point. Raw asesbtos materials and dust composition of local asbestos processing corporations were collected and analyzed using X-ray diffraction method.
RESULTSRaw materials of asbestos used between 1984 and 2010 in this area were chrysotile from Sichuan, Qinghai, Xinjiang, Russia, Zimbabwe, and some were mixed with SiO2, CaCO3 and other impurities. Raw materials used in asbestos board production were blue asbestos. Dust concentration between 1960s and 1980s in asbestos processing plants far exceeded the national standard. After then the dust concentration decreased significantly, but still higher than the national standard. 95.2% of air dust concentrations in the workplaces of asbestos factories exceeded the standard, and dust concentrations of workplaces of raw material, spinning, weaving, carding and labor insurance were above 90% in which carding work had the highest median concentration. 37.9% of dust mass concentrations in hand spinning work exceeded the standard where textile machinery side had the highest value. Beating job in asbestos board manufacturing and grinding job in brake production had higher concentrations.
CONCLUSIONSMost of production technologies in asbestos processing industry exceed the standard level, indicating that the workers were at risk for malignant mesothelioma and other asbestos related diseases, which should draw high attention.
Asbestos ; analysis ; Asbestos, Crocidolite ; analysis ; Asbestos, Serpentine ; analysis ; China ; epidemiology ; Dust ; analysis ; Humans ; Lung Neoplasms ; epidemiology ; Mesothelioma ; epidemiology ; Occupational Diseases ; epidemiology ; Silicon Dioxide ; analysis ; Workplace
3.Comparison of biocompatibility of four root perforation repair materials.
Min Kyung KANG ; In Ho BAE ; Jeong Tae KOH ; Yun Chan HWANG ; In Nam HWANG ; Won Mann OH
Journal of Korean Academy of Conservative Dentistry 2009;34(3):192-198
This study was carried out in order to determine in vitro biocompatibility of white mineral trioxide aggregate (MTA), and to compare it with that of the commonly used materials, i. e. calcium hydroxide liner (Dycal), glass ionomer cement (GIC), and Portland cement which has a similar composition of MTA. To assess the biocompatibility of each material, cytotoxicity was examined using MG-63 cells. The degree of cytotoxicity was evaluated by scanning electron microscopy (SEM) and a colorimetric method, based on reduction of the tetrazolium salt 2,3 bis {2methoxy 4nitro 5[(sulfenylamino) carbonyl] 2H tetrazolium hydroxide} (XTT) assay. The results of SEM revealed the cells in contact with GIC, MTA, and Portland cement at 1 and 3 days were apparently healthy. In contrast, cells in the presence of Dycal appeared rounded and detached. In XTT assay, the cellular activities of the cells incubated with all the test materials except Dycal were similar, which corresponded with the SEM observation. The present study supports the view that MTA is a very biocompatible root perforation repair material. It also suggests that cellular response of Portland cement and GIC are very similar to that of MTA.
Acrylic Resins
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Aluminum Compounds
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Calcium Compounds
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Calcium Hydroxide
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Drug Combinations
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Glass Ionomer Cements
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Glutamates
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Guanine
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Humans
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Hydroxides
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Microscopy, Electron, Scanning
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Minerals
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Oxides
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Silicates
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Silicon Dioxide
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Pemetrexed
4.Effect of Asbestos on Fibroblast Proliferation of Rat.
Kyoung Ah KIM ; Dong Won LEE ; Young LIM ; Im Goung YUN
Korean Journal of Occupational and Environmental Medicine 1996;8(3):392-402
Asbestosis is a chronic inflammatory disorder of lower respiratory tract in which alveolar wall are progressively thickened by a fibrotic process. Fibrotic process characterized by an expansion of fibroblast and collagenous extracellular matrix secreted from this fibroblast. Alveolar macrophage is believed to be a primary target cell and major participant in the evolution of lung fibrosis after asbestos inhalation. Alveolar macrophage are known to release a variety of substance that induce tissue damage and stimulate inflammatory cells and fibroblast. Macrophage also release a variety of metabolite of arachidonic acid. Of these, PGE(2) is known to suppress fibroblast proliferation. Asbestos may be a very effective stimulus for fibroblasts without triggering the relase of PGE(2). To assess the fibrogenic properties of asbestos according to kind and dosage of asbestos and the ability of PGE(2) to suppress the proliferation of fibroblast, alveolar macrophages cultured with crocidolite, amosite and chrysotile in presence or absence of PGE(2)10(-5)M. At 24 hours after alveolar macrophage cultured with various stimuli, the released fibronectin and TNF-alpha was measured. Viability of alveolar macrophages was observed and growth promoting activity of macrphage supernatant to fibroblasts was quantified. The results were as follows; 1. The viability of alveoair macrophages stimulated with asbestos fiber was markedly decreased compared with control group except chrysotile 10 microgram group. Crocidolite and amosite were more cytotoxic than chrysotile. 2. All of asbestos augmented fibronectin production in concentration dependent fashion. 3. There was a significant positive correlation between TNF-alpha production in supernatant and fiber concentration. 4. Supernatant from alveolar macrophages cultured with asbestos were inducible a significant increase in fibroblast proliferation. 5. Incubation of avieolar macrophages with asbestos in the presence of PGE(2) resulted in significant decrease of TNF-alpha production in supernant. 6. Supernatant from alveolar macrophages cultured with asbestos were inducible a: sig nificnat decrease in fibroblast proliferation when PGE(2) was added. The result of this study strongly suggested that crocidolite and amosite were more cytotoxic and fibrogenic and exogenous PGE(2) suppressed fibroblast proliferation following exposed to asbestos.
Animals
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Arachidonic Acid
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Asbestos*
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Asbestos, Amosite
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Asbestos, Crocidolite
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Asbestos, Serpentine
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Asbestosis
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Collagen
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Extracellular Matrix
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Fibroblasts*
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Fibronectins
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Fibrosis
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Inhalation
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Lung
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Macrophages
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Macrophages, Alveolar
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Rats*
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Respiratory System
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Tumor Necrosis Factor-alpha
5.Selenium: More than just a micronutrient mineral.
Nasar Alwahaibi ; Jamaludin Mohamed
Malaysian Journal of Nutrition 2007;13(1):101-107
Selenium is a micronutrient mineral found mainly in soils. Studies on selenium have increased rapidly worldwide especially after it has been shown to reduce the risk of certain types of cancer in humans and animals. The exact mechanism of action on how selenium inhibits diseases, in particular cancer, is still unknown. To date, the use of selenium in preventing or treating diseases is limited. However, many aspects about the biochemistry of selenium have been identified. This article reviews a number of key clinical, experimental and epidemiological studies on selenium as an anti-carcinogenic agent for some types of cancers. Some nutritional information on selenium and its recommended intake are also included. More clinical and experimental studies are needed to confirm previous findings on the role of selenium as an anticarcinogenic agent.
Selenium
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Selenium measurement
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Minerals
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experiment
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Clinical
6.Ingredients and cytotoxicity of MTA and 3 kinds of Portland cements.
Seok Woo CHANG ; Hyun Mi YOO ; Dong Sung PARK ; Tae Seok OH ; Kwang Shik BAE
Journal of Korean Academy of Conservative Dentistry 2008;33(4):369-376
The aim of this study was to compare the compositions and cytotoxicity of white ProRoot MTA (white mineral trioxide aggregate) and 3 kinds of Portland cements. The elements, simple oxides and phase compositions of white MTA (WMTA), gray Portland cement (GPC), white Portland cement (WPC) and fast setting cement (FSC) were measured by inductively coupled plasma atomic emission spectrometry (ICP-AES), X-ray fluorescence spectrometry (XRF) and X-ray diffractometry (XRD). Agar diffusion test was carried out to evaluate the cytotoxicity of WMTA and 3 kinds of Portland cements. The results showed that WMTA and WPC contained far less magnesium (Mg), iron (Fe), manganese (Mn), and zinc (Zn) than GPC and FSC. FSC contained far more aluminum oxide (Al2O3) than WMTA, GPC, and WPC. WMTA, GPC, WPC and FSC were composed of main phases, such as tricalcicium silicate (3CaO.SiO2), dicalcium silicate (2CaO.SiO2), tricalcium aluminate (3CaO.Al2O3), and tetracalcium aluminoferrite (4CaO.Al2O3.Fe2O3). The significance of the differences in cellular response between WMTA, GPC, WPC and FSC was statistically analyzed by Kruskal-Wallis Exact test with Bonferroni's correction. The result showed no statistically significant difference (p > 0.05). WMTA, GPC, WPC and FSC showed similar compositions. However there were notable differences in the content of minor elements, such as aluminum (Al), magnesium, iron, manganese, and zinc. These differences might influence the physical properties of cements.
Agar
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Aluminum
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Aluminum Oxide
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Calcium Compounds
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Diffusion
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Glutamates
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Guanine
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Humans
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Iron
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Magnesium
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Manganese
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Oxides
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Plasma
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Silicates
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Spectrometry, X-Ray Emission
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Spectrum Analysis
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Zinc
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Pemetrexed
7.Physical and chemical properties of pulp capping materials based on bioactive glass.
Yun Zi LONG ; Si Yi LIU ; Wen LI ; Yan Mei DONG
Journal of Peking University(Health Sciences) 2018;50(5):887-891
OBJECTIVE:
To investigate the physical and chemical properties of pulp capping materials based on bioactive glass (BG).
METHODS:
Novel BG pulp capping materials were composed of powder and fluid. The powder was BG (82.36% SiO2, 15.36% CaO, and 2.28% P2O5) synthesized by using the sol-gel method combined with template technology. Two kinds of fluid were provided: (1) phosphate buffer (PB) solution and (2) phosphate buffer solution with 1% sodium alginate (SA) addition. After mixing the powder and fluid, BG-PB and BG-PB-SA were prepared. Setting time and compressive strength of the BG pulp capping materials were tested by setting time loading system and mechanical testing machine. Statistical analysis was performed using the independent sample t-test, with the significance set at 0.05. pH meters was used to test the pH of the BG pulp capping materials and mineral trioxide aggregate (MTA). The sealing ability of the BG pulp capping materials and MTA was tested by methylene blue dye leakage model. Statistical analysis was performed using one-way ANOVA analysis and LSD multiple comparison, with the significance set at 0.05.
RESULTS:
(1) Setting time: the initial and final setting time of BG-PB were (7.2±0.3) min and (12.7±0.9) min, respectively. And the initial and final setting time of BG-PB-SA was (7.5±0.3) min and (13.6±1.6) min. There was no significant difference between BG-PB and BG-PB-SA groups (P>0.05). (2) Compressive strength: the compressive strength of BG-PB was (16.5±1.8) MPa at 1 day and (14.1±3.7) MPa at the end of 28 days. However, the compressive strength of BG-PB-SA was (26.6±6.3) MPa on day 1 and (21.6±5.6) MPa on day 28, which was significantly higher than that of BG-PB (P<0.05). (3) pH: the pH of BG pulp capping materials' bulk immersed in simulated body fluid (SBF) went up to 8.06, and the highest pH of MTA was 8.47. Significant difference was observed between the BG pulp capping materials and MTA (P<0.05). (4) Sealing ability: the optical density (D) in positive control group was significantly higher than ln BG-PB, BG-PB-SA and MTA groups (P<0.05). And BG-PB and BG-PB-SA showed the similar favorable sealing ability with MTA, and no significant difference was observed among the three groups (P>0.05).
CONCLUSION
The novel BG pulp capping materials showed good physical properties, especially BG's setting time was short; BG pulp capping materials are promising.
Aluminum Compounds
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Calcium Compounds
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Compressive Strength
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Dental Pulp Capping
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Glass
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Materials Testing
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Oxides
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Silicates
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Silicon Dioxide
8.Preparation and properties of silica/hydroxyapatite whiskers porous ceramics scaffold.
Yuxi WAN ; Qiangguo CHEN ; Tingting YAN
Chinese Journal of Reparative and Reconstructive Surgery 2023;37(9):1142-1148
OBJECTIVE:
To investigate the preparation and properties of the novel silica (SiO 2)/hydroxyapatite (HAP) whiskers porous ceramics scaffold.
METHODS:
The HAP whiskers were modified by the SiO 2 microspheres using the Stöber method. Three types of SiO 2/HAP whiskers were fabricated under different factors (for the No.1 samples, the content of tetraethoxysilane, stirring time, calcination temperature, and soaking time were 10 mL, 12 hours, 560℃, and 0.5 hours, respectively; and in the No.2 samples, those were 15 mL, 24 hours, 650℃, and 2 hours, respectively; while those in the No.3 samples were 20 mL, 48 hours, 750℃, and 4 hours, respectively). The phase and morphology of the self-made HAP whisker and 3 types of SiO 2/HAP whiskers were detected by the X-ray diffraction analysis and scanning electron microscopy. Taken the self-made HAP whisker and 3 types of SiO 2/HAP whiskers as raw materials, various porous ceramic materials were prepared using the mechanical foaming method combined with extrusion molding method, and the low-temperature heat treatment. The pore structure of porous ceramics was observed by scanning electron microscopy. Its porosity and pore size distribution were measured. And further the axial compressive strength was measured, and the biodegradability was detected by simulated body fluid. Cell counting kit 8 method was used to conduct cytotoxicity experiments on the extract of porous ceramics.
RESULTS:
The SiO 2 microspheres modified HAP whiskers and its porous ceramic materials were prepared successfully, respectively. In the SiO 2/HAP whiskers, the amorphous SiO 2 microspheres with a diameter of 200 nm, uniform distribution and good adhesion were attached to the surface of the whiskers, and the number of microspheres was controllable. The apparent porosity of the porous ceramic scaffold was about 78%, and its pore structure was composed of neatly arranged longitudinal through-holes and a large number of micro/nano through-holes. Compared with HAP whisker porous ceramic, the axial compressive strength of the SiO 2/HAP whisker porous ceramics could reach 1.0 MPa, which increased the strength by nearly 4 times. Among them, the axial compressive strength of the No.2 SiO 2/HAP whisker porous ceramic was the highest. The SiO 2 microspheres attached to the surface of the whiskers could provide sites for the deposition of apatite. With the content of SiO 2 microspheres increased, the deposition rate of apatite accelerated. The cytotoxicity level of the prepared porous ceramics ranged from 0 to 1, without cytotoxicity.
CONCLUSION
SiO 2/HAP whisker porous ceramics have good biological activity, high porosity, three-dimensional complex pore structure, good axial compressive strength, and no cytotoxicity, which make it a promising scaffold material for bone tissue engineering.
Animals
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Durapatite
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Porosity
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Vibrissae
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Apatites
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Ceramics
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Silicon Dioxide
9.Relationship Between Mineral Fiber-Induced Pulmonary Tissue Reaction and MIP-2.
Kyoung Ah KIM ; Young LIM ; Dong Won LEE ; Heung Nam KIM ; Hwang Sin CHANG ; Ji Hong KIM ; Hwa Suck SUH ; Chung Yill PARK ; Im Goung YUN
Korean Journal of Occupational and Environmental Medicine 1997;9(4):650-658
The pulmonary recruitment and activation of inflammatory cells, in particular, neutrophils is thought to contribute to lung injury resulting from dust exposure. MIP-2 (macrophage inflammatory protein-2) which is a member of C-X-C chemokine plays a key role in neutrophil recruitment to sites of tissue injury. Especially, mineral fiber induced pulmonary response is as a model for the neutrophil recruitment. Therefore, we evaluated the distribution of MIP-2 expression in lung tissue of mineral fiber exposed rat using immunohistochemical study and the relationship between degree of inflammation of lower respiratory tract and MIP-2 expression. Total cell counts in bronchoalveolar lavage (BAL) fluid in mineral fiber-exposed group were markedly increased compared with each control group even not in ceramic fiber group. Number of neutrophil in BAL fluid in mineral fiber-exposed group were markedly increased compared with each control group until 4th week but except ceramic fiber group. In chrysotile group, number of neutrophil in BAL fluid were markedly increased compared with control group at 8th week. Lung tissue instilled with all kinds of mineral fibers showed remarkable developments of bronchus associated lymphoid tissue (BALT) and small multiple granulomas but not for ceramic fiber group. In chrysotile group, multiple granuloma and inflammatory change were more profuse response compared with other groups. MIP-2 was predominently expresses in epithelial cells of bronchioles and bronchus and was express also found in macrophages with lung section at 1 week after fiber instillation. Small amount of epithelial cell associated MIP-2 was present in chrysotile at 8 week group. But MIP-2 was not seen in epithelial cells and macrophages in the lung tissue instilled with crocidolite, ceramic fiber and glass fiber at 8 weeks. Our finding suggest that MIP-2 is predominantly expressed in bronchial epithelial cells of lung from mineral fiber-exposed rat and correlated with inflammatory cell, especially neutrophil, recruitment and tissue reaction. And we documented that MIP-2 expression and neutrophil recruitment in man-made vitreous fiber-exposed rat, especially glass fiber, less than chrysotile.
Animals
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Asbestos, Crocidolite
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Asbestos, Serpentine
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Bronchi
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Bronchioles
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Bronchoalveolar Lavage
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Cell Count
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Ceramics
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Dust
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Epithelial Cells
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Glass
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Granuloma
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Inflammation
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Lung
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Lung Injury
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Lymphoid Tissue
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Macrophages
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Mineral Fibers
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Neutrophil Infiltration
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Neutrophils
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Rats
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Respiratory System
10.Mineral trioxide aggragate pulpotomy for the treatment of immature permanent teeth with irreversible pulpitis: a preliminary clinical study.
Chufang PENG ; Yuming ZHAO ; Yuan YANG ; Man QIN ; Email: QIN-MAN@FOXMAIL.COM.
Chinese Journal of Stomatology 2015;50(12):715-719
OBJECTIVETo evaluate the preliminary clinical effect of mineral trioxide aggragate (MTA) pulpotomy on immature permanent teeth with irreversible pulpitis.
METHODSTwenty-six immature permanent teeth with irreversible pulpitis were recuited from Department of Pediatric Dentistry, Peking University School and Hospital of Stomatology. These teeth were treated with partial or full pulpotomy according to the condition of pulp bleeding. MTA was used as pulp capping material. Patients were recalled periodically after the treatment. Clinical and radiographic effects were evaluated.
RESULTSAt one year follow-up, 20 teeth were evaluated as healed or healing, 2 teeth were evaluated as failure and 4 teeth were dropped out. The success rate was considered 91% (20/22). A dentinal bridge was radiographcally observed underneath the pulpotomy site in 13 teeth(65%, 13/20).
CONCLUSIONSMTA pulpotomy is an effective method for the treatment of immature permanent teeth with irreversible pulpitis. But further research with longer follow up period is required.
Aluminum Compounds ; therapeutic use ; Beijing ; Calcium Compounds ; therapeutic use ; Child ; Dental Pulp Capping ; methods ; Dentition, Permanent ; Follow-Up Studies ; Humans ; Minerals ; Molar ; Oxides ; therapeutic use ; Pulpitis ; surgery ; Pulpotomy ; methods ; Silicates ; therapeutic use