Artificial quartz dust exposure may cause associated pneumoconiosis. From November 2019 to July 2020, a total of 27 cases of silicosis associated with artificial quartz stone manufacturers were diagnosed and treated in the Occupational disease Department of Suzhou Fifth People's Hospital. The average age of onset was (46.8±6.6) years, and the average working age of dust exposure was (5.7±1.7) years.The main feature of high KV chest radiography is P/S shadow with strip shadow. CT imaging findings showed diffuse small nodules and ground glass shadows with band shadows. The lesions were mainly distributed in the upper lung, accompanied by pleural thickening, lymphadenopathy and calcification. The pulmonary function impairment was mainly mild restrictive ventilation disorder, and the bronchial mucosa longitudinal plica was the main manifestation under tracheoscopy. The age of silicosis of workers in artificial quartz stone production enterprises is younger, the working age of dust exposure is short, the lung function and bronchial mucosa have a certain degree of damage, and effective preventive measures should be taken in time.
Adult ; Child ; Child, Preschool ; Dust ; Humans ; Middle Aged ; Occupational Exposure/adverse effects* ; Pneumoconiosis/complications* ; Quartz/analysis* ; Silicosis/diagnosis*

BACKGROUND: Bone tissue engineering based on pluripotent stem cells (PSCs) is a new approach to deal with bone defects. Protocols have been developed to generate osteoblasts from PSCs. However, the low efficiency of this process is still an important issue that needs to be resolved. Many studies have aimed to improve efficiency, but developing accurate methods to determine efficacy is also critical. Studies using pluripotency to estimate efficacy are rare. Telomerase is highly associated with pluripotency. METHODS: We have described a quantitative method to measure telomerase activity, telomeric repeat elongation assay based on quartz crystal microbalance (QCM). To investigate whether this method could be used to determine the efficiency of in vitro osteogenic differentiation based on pluripotency, we measured the pluripotency pattern of cultures through stemness gene expression, proliferation ability and telomerase activity, measured by QCM. RESULTS: We showed that the pluripotency pattern determined by QCM was similar to the patterns of proliferation ability and gene expression, which showed a slight upregulation at the late stages, within the context of the general downregulation tendency during differentiation. Additionally, a comprehensive gene expression pattern covering nearly every stage of differentiation was identified. CONCLUSION: Therefore, this assay may be powerful tools for determining the efficiency of differentiation systems based on pluripotency. In this study, we not only introduce a new method for determining efficiency based on pluripotency, but also provide more information about the characteristics of osteogenic differentiation which help facilitate future development of more efficient protocols.
Bone and Bones ; Down-Regulation ; Gene Expression ; In Vitro Techniques ; Methods ; Mouse Embryonic Stem Cells ; Osteoblasts ; Pluripotent Stem Cells* ; Quartz Crystal Microbalance Techniques ; Telomerase* ; Up-Regulation

BACKGROUND: Occupational exposure to crystalline silica is a potential risk factor for various systemic autoimmune diseases including systemic sclerosis. The etiology of systemic sclerosis is not conclusively known, but there are epidemiological studies that show the relationship between exposure to crystalline silica and risk of systemic sclerosis. Here we report, for the first time, two cases of crystalline silica-related systemic sclerosis in patients who worked in crystal processing in the jewelry-manufacturing field. CASE PRESENTATION: Case 1 is a 57-year-old man who had worked mainly in crystal processing for multiple jewelry-processing companies for 17 years, since the age of 15 years. He contracted tuberculosis at the age of 25 years and showed Raynaud's phenomenon of both the hands and feet at age 32 years. Digital cyanosis and sclerosis developed at approximately age 41 years. The patient was diagnosed with systemic sclerosis at age 48 years. Case 2 is a 52-year-old man who worked in crystal processing for various jewelry-processing companies for 7 years, since the age of 23 years. He first showed signs of cyanosis in the third and fourth digits of both hands at age 32 years, was diagnosed with Raynaud's syndrome at age 37 years, and was diagnosed with systemic sclerosis at age 38 years. Crystal processing is a detailed process that involves slabbing and trimming the selected amethyst and quartz crystals, which requires close proximity of the worker's face with the target area. In the 1980s and 1990s, the working hours were 12 h per day, and the working environment involved 15 workers crowded into a small, 70-m2 space with poor ventilation. CONCLUSION: Two workers who processed crystals with a maximum crystalline silica content of 56.66% developed systemic sclerosis. Considering the epidemiological and experimental evidence, exposure to crystalline silica dust was an important risk factor for systemic sclerosis. An active intervention is necessary to reduce exposure in similar exposure groups in the field of jewelry processing.
Autoimmune Diseases ; Crystallins* ; Cyanosis ; Dust ; Epidemiologic Studies ; Foot ; Hand ; Humans ; Jewelry* ; Korea* ; Middle Aged ; Occupational Exposure ; Quartz ; Risk Factors ; Scleroderma, Systemic* ; Sclerosis ; Silicon Dioxide* ; Tuberculosis ; Ventilation

OBJECTIVETo develop a quartz crystal microbalance (QCM) immunosensor with high sensitivity and selectivity for the rapid detection of diethylstilbestrol.

METHODSDextran was used as reducing agent for preparing gold nanoparticles (AuNPs) with the size of 40 nm. The AuNPs were coupled with anti-DES antibody after amination. A monolayer was generated after immersing the quartz crystal into the solution of 5 mmol/L 11-mercaptoundecanoic acid(MUA) for 16 hours. After the monolayer was activated by 1-ethyl-3-(3-dimethylaminopropry) carbodiimide hydrochloride (EDC·HCl) and N-hydrosuccinimide (NHS), 20 μl of 2.2 mg/ml DES-HS-BSA was dropped onto the surface of crystal to prepare a sensitive membrane which can recognize DES specifically. Then, 50 μl of 1 mol/L ethanolamine (pH 8.5) was used to seal the carboxylic groups to make the sensitive membrane which could identify DES specifically. QCM immunosensor was used as detection platform to optimize the reaction conditions. Under the optimized conditions, 10 μl of 28 μg/ml AuNPs-antibody was mixed with 10 μl of 0.03-2.5 μg/ml DES, and the mixture was added on the sensitive membrane. QCM immunosensor was used to detect the signals and the standard curve was obtained at the same time. The detection limit was calculated based on the standard curve. The specificity was evaluated by testing DES and its analogues with the same concentration.

RESULTSThe optimized concentration for the immobilization of DES-HS-BSA on the surface of QCM was 2.2 mg/ml. The optimized concentration for coupling anti-DES antibody with AuNPs was 7 μg/ml and 15 nmol/L, respectively. The optimized concentration of AuNPs-antibody was 14 μg/ml. The logarithm of DES concentration was proportional to the frequency shift in the range of 0.16-500 ng/ml, Δf=-24.170 lgCDES+69.71, R(2)=0.998. The detection limit of this method was 0.13 ng/ml. DES analogues could not influence the detection of DES obviously, so the sensor had good specificity.

CONCLUSIONThe quartz crystal microbalance immunosensor with gold nanoparticals amplification could detect DES sensitively and rapidly.

Biosensing Techniques ; Diethylstilbestrol ; isolation & purification ; Gold ; Limit of Detection ; Nanoparticles ; Quartz Crystal Microbalance Techniques

The development and validation of a method for the determination of concentrations of thiocyanate in human plasma are described here. A modified colorimetric method of Bowler was used with the following alteration in Monica Manual, Part III. In order to obtain the same sensitivity in low amounts of clinical samples, quartz SUPRASIL(R) micro cuvettes have been used. The quantitation range was between 25-500 microM. Accuracy and precision of the quality control samples, linearity of the calibration curve, dilution, spike recovery and stability under various conditions were evaluated in the validation of the method and all demonstrated acceptable results. All validation results met good laboratory practice acceptance and FDA requirements to be acceptable for application in clinical trials. The validated method has been used for a Phase I clinical study in cancer patients orally administered with either 60 mg or 80 mg of GDC-0425 containing a cyanide (CN-) group. The thiocyanate levels from patients before and after drug administration showed no clinically significant differences.
Calibration ; Humans* ; Plasma* ; Quality Control ; Quartz ; Spectrophotometry*

OBJECTIVETo compare the effects of oral treatment with tetrandrine (TD) and N-acetylcys-teine (NAC) separately or jointly on silica-exposed rats.

METHODS40 sprague-Dawly (SD) rats were randomly divided into normal saline group, quartz group, TD treatment group (50 mg/kg), NAC treatment group (500 mg/kg) and combined treatment group (TD: 50 mg/kg + NAC: 500 mg/kg). Rats in normal saline group and other groups received intratracheal instillation of normal saline and quartz dust suspension respectively. Treatment groups were given TD, NAC separately or jointly via esophagus the next day after instillation, once a day and six times a week for 30 consecutive days. At the end of experiment, the pathological changes of lung tissues were evaluated by the methods of Foot, HE and Masson staining, the level of hydroxyproline (HYP), malondjalde-hyde (MDA), tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in lung tissues were measured by alkaline hydrolysis method, the barbituric acid method and enzyme-linked immunosorbent assay (ELISA) respectively.

RESULTSCompared with the quartz group, lymph nodes/body coefficients in all treatment groups and lung/body coefficient in combined treatment group were significantly decreased (P < 0.05). Pathology results showed that the normal saline group demonstrated no obvious evidence of lung damage. The quartz group lungs silicotic lesions focused on II~III level, the TD treatment group was mainly with I level, the NAC treatment group was mainly with I~II level, and the combined treatment group only showed little silicotic nodule, no obvious fibrosis. HYP content in TD treatment group and combined treatment group were significantly lower than that in the quartz group (P < 0.05), while it showed no obvious change in NAC treatment group. MDA content in lung tissues of each treatment group (TD treatment group, NAC treatment group and combined treatment group) were 18.80 ± 2.94, 20.13 ± 4.01 and 17.05 ± 3.52 nmol/ml respectively, which lower than in the quartz group (23.99 ± 3.26 nmol/ml). The level of IL-6 in lung tissues of the quartz group were 89.57 ± 8.78 pg/ml. After TD and NAC monotherapy, the IL-6 content decreased to 79.22 ± 9.65 pg/ml and 81.63 ± 5.72 pg/ml, and it decreased more significantly after combined medication (74.37 ± 3.17 pg/ml). The level of TNF-α in the quartz group were 59.05 ± 4.48 pg/ml. After TD and NAC monotherapy, the TNF-α content decreased to 50.48 ± 2.76 pg/ml and 54.28 ± 4.30 pg/ml, and it decreased more significantly after combined medication (49.10 ± 4.98 pg/ml).

CONCLUSIONNAC and TD could reduce MDA, TNF-α and IL-6 levels in lung tissue, and alleviate SiO2-induced pulmonary fibrosis in rats. Combined treatment with TD and NAC was more effective than TD or NAC treatment separately.

Acetylcysteine ; pharmacology ; Animals ; Benzylisoquinolines ; pharmacology ; Disease Models, Animal ; Dust ; Hydroxyproline ; metabolism ; Interleukin-6 ; metabolism ; Lung ; pathology ; Malondialdehyde ; metabolism ; Pulmonary Fibrosis ; chemically induced ; drug therapy ; Quartz ; toxicity ; Rats ; Rats, Wistar ; Silicon Dioxide ; toxicity ; Silicosis ; drug therapy ; Tumor Necrosis Factor-alpha ; metabolism

OBJECTIVETo investigate the role of calcium activated-potassium channels (KCa) in the injury to rat alveolar macrophages induced by quartz.

METHODSThe experiments were conducted on a rat alveolar macrophage cell line (NR8383) in vitro, where crystal silica (100 üg/ml) and amorphous silica (100 üg/ml) were used as the test substances and the cells without any treatment as negative controls. At first the effects of two kinds of quartz were compared. Then KCa special inhibitors (Paxilline for BK, Tram-34 for IK, Apamin for SK) were added in different doses to the in vitro test system with 100 üg/ml crystal quartz as matrix, to observe the function of such channels. Cell viability, lactate dehydrogenase (LDH), interleukin-1β (IL-1β) and tumor necrosis factor-a (TNF-α) were tested.

RESULTSComparing to the negative control group, cell viability reduced, LDH leakage, IL-1β and TNF-α release increased significantly in the amorphous quartz group, furthermore, the effects by crystal quartz were much more serious than those by amorphous quartz, with a statistical significance (P < 0.01). Comparing to the crystal quartz group, IK blockers (Tram-34) led to increase in cell viability significantly, with a statistical significance (P < 0.01); all the KCa specific blockers (Paxilline, Tram-34, Apamin) could reduce LDH leakage and IL-1β release, with a statistical significance (P < 0.05); meanwhile, BK and IK blockers (Paxilline,Tram-34) were able to reduce TNF-α release,with a statistical significance (P < 0.05).Reduction of IL-1β and TNF-α by Tram-34 was dose-dependent, but not so in the other two blockers.

CONCLUSIONBlocking calcium-activated potassium channels (KCa) could reduce cell membrane damage as well as IL-1β and TNF-α release induced by crystal quartz in the rat alveolar macrophages cell line in vitro, which might serve as a signal in the early regulation of inflammatory responses by quartz.

Animals ; Calcium ; metabolism ; Cell Line ; Interleukin-1beta ; metabolism ; Macrophages, Alveolar ; cytology ; metabolism ; Potassium Channels, Calcium-Activated ; metabolism ; Quartz ; toxicity ; Rats ; Tumor Necrosis Factor-alpha ; metabolism

OBJECTIVETo investigate the role of oxidative stress in the endoplasmic reticulum stress-induced apoptosis of alveolar macrophages triggered by quartz dust.

METHODSSeventy-two healthy adult Wistar rats were randomly divided into control group, quartz dust group, quartz dust plus N-acetyl cysteine (NAC) group, and NAC group, with 18 rats in each group. One milliliter of sterile saline (for the control and NAC groups) or 1 ml of saline with 5%ultrafine quartz dust (for dust group and dust plus NAC group) was given to each rat by non-exposed endotracheal infusion. From the second day after dust infusion, rats in dust plus NAC group and NAC group received intragastric administration of NAC (100 mg/kg). In each week, the treatment with NAC lasted for 5 consecutive days, followed by 2 days' interval. For each group, 6 rats were randomly selected on the 14th, 28th, or 56th day after dust exposure; they were sacrificed by bloodletting from the femoral artery, and the lungs were collected. Bronchoalveolar lavage fluid was collected to separate macrophages. The protein expression of caspase-12 in alveolar macrophages, the apoptosis rate and reactive oxygen species (ROS) content of alveolar macrophages, and the protein carbonyl content of alveolar macrophages were determined by Western blot, flow cytometry, and colorimetry, respectively.

RESULTSIncreased protein expression of caspase-12, apoptosis rate, and content of ROS and protein carbonyl were discovered on the 14th day in the dust group, in comparison with the control group (P < 0.05), and the increase lasted till the 28th and 56th days. (P < 0.05). Compared with the dust group, the dust plus NAC group showed significant decreases in the content of ROS on the 14th, 28th, and 56th days (P < 0.05), significant decreases in the content of protein carbonyl on the 28th and 56th days (P < 0.05), and significant decreases in the protein expression of caspase-12 and apoptosis rate (P < 0.05).

CONCLUSIONOxidative stress is potentially involved in the endoplasmic reticulum stress-induced apoptosis of alveolar macrophages triggered by quartz dust. Oxidative damage of protein in the endoplasmic reticulum may play an important role in the process.

Animals ; Caspase 12 ; metabolism ; Dust ; Endoplasmic Reticulum Stress ; drug effects ; Macrophages, Alveolar ; drug effects ; pathology ; Male ; Oxidative Stress ; drug effects ; Protein Carbonylation ; Quartz ; toxicity ; Rats ; Rats, Wistar ; Reactive Oxygen Species ; metabolism

Teeth that have short clinical crown, which are not alone enough to support the definitive restoration can be best treated using the post and core system. The advantages of fiber post over conventional metallic post materials have led to its wide acceptance. In addition to that the combination of aesthetic and mechanical benefits of fiber post has provided it with a rise in the field of dentistry. Also the results obtained from some clinical trials have encouraged the clinicians to use the fiber posts confidently. Fiber posts are manufactured from pre-stretched fibers impregnated within a resin matrix. The fibers could that be of carbon, glass/silica, and quartz, whereas Epoxy and bis-GMA are the most widely used resin bases. But recently studies are also found to be going on for polyimide as possible material for the fiber post resin base as a substitute for the conventional materials.
Bisphenol A-Glycidyl Methacrylate ; Carbon ; Crowns ; Dentin ; Dentistry ; Quartz ; Tooth

OBJECTIVES: Light-curing of resin-based materials (RBMs) increases the pulp chamber temperature, with detrimental effects on the vital pulp. This in vitro study compared the temperature rise under demineralized human tooth dentin during light-curing and the degrees of conversion (DCs) of three different RBMs using quartz tungsten halogen (QTH) and light-emitting diode (LED) units (LCUs). MATERIALS AND METHODS: Demineralized and non-demineralized dentin disks were prepared from 120 extracted human mandibular molars. The temperature rise under the dentin disks (n = 12) during the light-curing of three RBMs, i.e. an Ormocer-based composite resin (Ceram. X, Dentsply DeTrey), a low-shrinkage silorane-based composite (Filtek P90, 3M ESPE), and a giomer (Beautifil II, Shofu GmbH), was measured with a K-type thermocouple wire. The DCs of the materials were investigated using Fourier transform infrared spectroscopy. RESULTS: The temperature rise under the demineralized dentin disks was higher than that under the non-demineralized dentin disks during the polymerization of all restorative materials (p < 0.05). Filtek P90 induced higher temperature rise during polymerization than Ceram.X and Beautifil II under demineralized dentin (p < 0.05). The temperature rise under demineralized dentin during Filtek P90 polymerization exceeded the threshold value (5.5degrees C), with no significant differences between the DCs of the test materials (p > 0.05). CONCLUSIONS: Although there were no significant differences in the DCs, the temperature rise under demineralized dentin disks for the silorane-based composite was higher than that for dimethacrylate-based restorative materials, particularly with QTH LCU.
Dental Pulp Cavity ; Dentin* ; Humans ; Molar ; Polymerization* ; Polymers* ; Quartz ; Spectroscopy, Fourier Transform Infrared ; Tooth ; Tungsten