OBJECTIVETo prepare and evaluate novel chlorine dioxide-based disinfectant powder in single-pack that is more convenient for use and transportation.

METHODSOrthogonal experiment was performed to determine the recipe of the disinfectant powder. Stability test, suspension quantitative bactericidal test, simulation field trial, and animal toxicity test were carried out to observe its bactericidal and toxicological effects.

RESULTSThe orthogonal experiment showed that the type of water solution had no effect on the disinfectant powder and the best ratio of sodium chlorite to solid acid was 1:3. Ten grams of the disinfectant powder was fully dissolved in 20 mL water for 2 min, and diluted to 500 mL in water. After 5-10 min, the concentration of chlorine dioxide (ClO2) solution was 266 mg/L to 276 mg/L. After stored at 54 degrees C for 14 d, the average concentration of ClO2 was decreased by 5.03%. Suspension quantitative bactericidal test showed that the average killing logarithm (KL) value for both Staphylococcus aureus and Escherichia coli in 100 mg/L ClO2 solution for 2 min was over 5.00. in simulation field trial, the average descending KL value for Escherichia coli in the solution containing 100 mg/L ClO2 for 5 min was over 3.00. The mouse acute LD50 in the solution 5 times exceeded 5000 mg/kg. The disinfectant powder was not toxic and irritative to rabbit skin and had no mutagenic effect on mouse marrow polychromatic erythrocytes (PCE).

CONCLUSIONThe stability and bactericidal efficacy of solid chlorine dioxide-based disinfectant powder in single-pack are good. The solution containing 100 mg/L ClO2 can kill vegetative forms of bacteria. The concentration of ClO2 on the disinfecting surface of objects is 100 mg/L. The disinfectant powder is not toxic and irritative.

Chlorine Compounds ; pharmacology ; Disinfectants ; pharmacology ; Escherichia coli ; drug effects ; Oxides ; pharmacology ; Staphylococcus aureus ; drug effects

OBJECTIVES: This study aimed to investigate the effect of new biomimetic micro/nano surfaces on the osteoclastic differentiation of RAW264.7 macrophages by simulating natural osteons for the design of concentric circular structures and modifying graphene oxide (GO). METHODS: The groups were divided into smooth titanium surface group (SS), concentric microgrooved titanium surface group (CMS), and microgroove modified with GO group (GO-CMS). The physicochemical properties of the material surfaces were studied using scanning electron microscopy (SEM), contact-angle measurement, atomic force microscopy, X-ray photoelectron spectroscopy analysis, and Raman spectroscopy. The effect of the modified material surface on the cell biological behavior of RAW264.7 was investigated by cell-activity assay, SEM, and laser confocal microscopy. The effect on the osteoclastic differentiation of macrophages was investiga-ted by tartrate-resistant acid phosphatase (TRAP) immunofluorescence staining and quantitative real-time polymerase chain reaction (qRT-PCR) experiments. RESULTS: Macrophages were arranged in concentric circles along the microgrooves, and after modification with GO, the oxygen-containing groups on the surface of the material increased and hydrophilicity increased. Osteoclasts in the GO-CMS group were small in size and number and had the lowest TRAP expression. Although it promoted the proliferation of macrophages in the GO-CMS group, the expression of osteoclastic differentiation-related genes was lower than that in the SS group, and the difference was statistically significant (P<0.05). CONCLUSIONS Concentric circular microgrooves restricted the fusion of osteoclasts and the formation of sealing zones. Osteomimetic concentric microgrooves modified with GO inhibited the osteoclastic differentiation of RAW 264.7 macrophages.
Graphite/pharmacology* ; Titanium/pharmacology* ; Haversian System ; Macrophages ; Cell Differentiation ; Oxides/pharmacology* ; Surface Properties

This study was aimed to investigate the change of expression and activity of protein phosphatases type 2A (PP2A) during the apoptosis of NB4 and MR2 cells induced by Arsenic trioxide (ATO). NB4 and MR2 cells were incubated with Okadaic acid (OKA) (0.5 nmol/L), ATO (0.5 - 2.0 micromol/L), and the combination of OKA and ATO at the same doses as in the single-agent treatment respectively. Then the proliferation of NB4 and MR2 cells was determined by MTT assay, the morphologic changes of cells were evaluated by Wright's staining, the apoptosis rates were detected by flow cytometry. At last, the activities of PP2A were evaluated by the serine/threonine phosphatase assay system, and the levels of PP2A subunits were detected by Western blot analysis. The results showed that ATO inhibited proliferation of NB4 and MR2 cells, and the inhibition rates of ATO on the two cells significantly increased after the addition of OKA. OKA could augment the apoptosis of NB4 and MR2 cells induced by ATO. During the apoptosis of NB4 and MR2 cells, the activity of PP2A decreased with increasing concentration of ATO, and OKA augmented the inhibitory effect of ATO on the activity. The level of PP2A structural subunit (PP2A-A) decreased during ATO-induced apoptosis of NB4 and MR2 cells, that expressions of B and C subunits of PP2A were relatively unaltered. It is concluded that the activity of PP2A decreases with increasing concentration of ATO during the apoptosis of NB4 and MR2 cells, and the decrease of the activity of PP2A maybe is related to the repression of expression of PP2A -A subunit; the inhibition of the activity of PP2A can promote the ATO induced apoptosis of NB4 and MRL cells.
Apoptosis ; drug effects ; Arsenicals ; pharmacology ; Cell Line, Tumor ; Humans ; Oxides ; pharmacology ; Protein Phosphatase 2 ; metabolism

Apoptosis ; drug effects ; Arsenicals ; pharmacology ; Cell Line, Tumor ; drug effects ; Humans ; Leukemia ; pathology ; Oxides ; pharmacology

Apoptosis ; drug effects ; Arsenicals ; pharmacology ; Cell Line, Tumor ; Humans ; Oxides ; pharmacology

OBJECTIVETo investigate whether ascorbic acid could enhance the efficacy of arsenic trioxide (As(2)O(3)) combined with 2, 3-dimethoxy-1, 4-naphthoquinone (DMNQ) in inducing the apoptosis of leukemia cell line U937 and its possible mechanism.

METHODSFlow cytometry and electron microscopy were applied to detect apoptosis of U937 cells after treatment with various combinations of As(2)O(3), DMNQ and ascorbic acid for 24 hours.

RESULTSAs(2)O(3) and DMNQ induced-apoptosis of U937 cells was enhanced (35.24%-->61.20%) upon cotreatment with ascorbic acid. Catalase could reverse this effect of DMNQ. Ascorbic acid had no effect on DMNQ-induced apoptosis of U937 cells.

CONCLUSIONAscorbic acid enhanced the apoptosis of U937 cells via reactive oxygen species-dependent pathway in the presence of As(2)O(3).

Apoptosis ; drug effects ; Arsenicals ; pharmacology ; Ascorbic Acid ; pharmacology ; Drug Synergism ; Flow Cytometry ; Humans ; Naphthoquinones ; pharmacology ; Oxides ; pharmacology ; U937 Cells

Animals ; Antineoplastic Agents ; pharmacology ; Apoptosis ; drug effects ; Arsenicals ; pharmacology ; HeLa Cells ; pathology ; Humans ; Leukemia, Promyelocytic, Acute ; pathology ; Oxides ; pharmacology

This study was aimed to investigate the effects of arsenic trioxide (As2O3) combined with TPA on cell cycle, cell differentiation and apoptosis of K562 cell line, and their possible mechanisms. K562 cells were treated with 200 nmol/L TPA, 2 µmol/L As2O3 alone and 200 nmol/L TPA combined with 2 µmol/L As2O3. The proliferative inhibition rates were determined with CCK-8. Annexin V and agarose gel electrophoresis were adopted to detect apoptosis. Colony formation test was used to determine the colony-formation efficiency. Flow cytometry was used to detect the cell differentiation and cell cycle changes. Western blot was employed to detect the expression of P38 and p-P38 proteins. The results showed that combination treatment had synergistic effects on the proliferative inhibition and apoptosis, which were much higher than those treated alone. As2O3 could decrease the colony formation ability of K562 cells. The cells treated with both TPA and As2O3 expressed far more CD11b antigens compared with cells exposed to As2O3 alone. K562 cells treated with TPA were arrested in G1 phase compared with the control group, As2O3 increased the percentage of K562 cells in the G2 phase. The combination treatment increased the expression of p-P38 of K562 cells compared with the cells exposed As2O3 alone. It is concluded that TPA can enhance the effect of As2O3 on inducing apoptosis and adjusting cell cycle , which will expect to provide a new therapeutic program.
Apoptosis ; drug effects ; Arsenicals ; pharmacology ; Cell Cycle ; drug effects ; Drug Synergism ; Humans ; K562 Cells ; Oxides ; pharmacology ; Tetradecanoylphorbol Acetate ; pharmacology

OBJECTIVETo evaluate the changes in dimensional accuracy of dental gypsum casts after immersion in stable chlorine dioxide (SCD) disinfectant solution.

METHODSEach of 90 specimens was made of type III,type IV and type V dental stone, respectively,which were further divided into 9 groups (n=10). The gypsum casts were immersed in 3.71,7.41 and 11.12 mmol/L SCD disinfectant solution for 5, 10 and 15 min, respectively. The dimensional accuracy of dental gypsum casts were measured with outside diameter in micrometer before and after immersion. The data were analyzed using analysis of variance (ANVOA) at 95% confidence level.

RESULTThere were no significant changes in dimensional accuracy of all dental gypsum casts treated by same concentration of SCD solution for 5, 10 and 15 min. And the dimensional accuracy of all dental gypsum casts treated with different concentrations of SCD for the same duration did not change.

CONCLUSIONSCD disinfectant solution has no impact on dimensional stability of dental gypsum casts.

Calcium Sulfate ; Chlorine Compounds ; pharmacology ; Dental Impression Materials ; Dental Models ; Disinfectants ; pharmacology ; Disinfection ; methods ; Immersion ; Oxides ; pharmacology

OBJECTIVETo evaluate the colouration of zirconia ceramic by adding three kinds of rare earth oxides. The influence of the pigments concentration on the mechanical properties and the microstructure was also analyzed.

METHODSAdded different concentrations of CeO(2), Er(2)O(3) and Pr(6)O(11) in tetragonal zirconia poly crystals stabilized with 3 mol% yttria (3Y-T2P) powder, compacted at 200 MPa using cold isostatic pressure, and sintered to 1 400 degrees C. The heating rate was 150 degrees C/h and the dwelling time was 2 hours. The chromaticity of sintered bodies was measured with chroma meter. The relative density, hardness, flexure strength and fracture toughness were investigated as well. The phase stability of the colorized and pure zirconia was evaluated by X-ray diffraction (XRD) using an automated diffractometer. The microstructures of the specimens were evaluated by scanning electron microscope (SEM).

RESULTSSeveral kinds of color achieved by the different pigments praseodym oxide, cerium oxide and erbium oxide were presented in the CIELab system. The a* value increased with the added amount of Er(2)O(3), while b* value rose with the increasing amount of CeO(2) and Pr(6)O(11). However, three pigments failed to decrease L* value and the sintered body appeared too bright. Adding three pigments influenced flexure strength of zirconia ceramic significantly, but had little influence on the hardness and fracture toughness. Microscopy revealed the relationship between the porosity and shapes of grains was correlated to strength of the diphase ceramics. No additional phase could be detected by XRD, except t-ZrO(2) in all colorized samples after sintering at 1 400 degrees C for 120 min.

CONCLUSIONSZirconia ceramic can be colorized by CeO(2), Er(2)O(3), and Pr(6)O(11). Pigments even in a small amount influence the mechanical properties of the colorized zirconia material, which necessitates further investigation.

Coloring Agents ; pharmacology ; Dental Porcelain ; chemistry ; Dental Stress Analysis ; Metals, Rare Earth ; pharmacology ; Oxides ; pharmacology ; Prosthesis Coloring ; Zirconium ; chemistry