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ABSTRACT: Fourteen Sprague-Dawley male rats were randomly divided into 2 groups which were given CdCl2 at the doses of 0 and 1.5 mg
/kg for 12 weeks. Before sacrifice, microCT scanning were performed on the proximal tibia and urine were collected for cadmium
and N-acetyl-beta-D-glucosaminidase assay, then all of rats were sacrificed and blood was collected for biomarkers measurement;
bone tissues were collected for bone mass, histology and biomechanical analysis. The cadmium in blood, urine, bone and kidney
of rats treated with cadmium was significantly higher than those in the control group. The bone mineral density, and bone
mineral ability of rats treated with cadmium were obviously decreased by 20%–50% compared to controls. Bone microstructure
index and trabecular separation of rats treated with cadmium were obviously lower (−50%) and significantly higher (+150%)
than that in the control group. Bone biomechanical property decreased by 30%–60% in cadmium treated rats compared to control.
Tartrate-resistant acid phosphatase 5b and alkaline phosphatase levels of rats treated with cadmium were significantly higher
than those in control, but serum osteocalcin level decreased greatly by cadmium. Obvious proximal tubule damage occurred after
cadmium exposure. These observations gave clear and comprehensive evidence that cadmium exposure could induce itai-itai-like
syndrome in male rats.
KeywordsCadmium–Bone microstructure–Tartrate-resistant acid phosphatase 5b–Bone mineral density–Micro-computed tomography–Itai-itai-like syndrome
Central European Journal of Medicine 04/2012; 6(4):425-434. · 0.31 Impact Factor
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ABSTRACT: The aim of this study was to evaluate the effects of a simulated porcelain-fused-to-metal (PFM) firing process on the surface,
corrosion behavior, and cell culture response of two cobalt–chromium (Co–Cr) dental alloys. Two Co–Cr dental alloys were tested—a
high and a low molybdenum (Mo)-containing alloys. Before PFM firing, as-cast alloy specimens were examined for their microstructure,
surface composition, and hardness. Corrosion behavior was evaluated using electrochemical impedance spectroscopy tests. Mouse
3T3 fibroblasts were exposed indirectly to specimens and MTT cell proliferation assays were performed after 3 and 6days.
The cell culture medium exposed to specimens was analyzed for metal ion release. After firing, similar alloy specimens were
examined for the same properties. The tests showed that the PFM firing changed both alloys’ microstructures and hardness values.
After PFM firing, the corrosion resistance of the low Mo-containing Co–Cr alloy decreased statistically, which corresponded
with a reduction of Cr and oxygen levels in the surface oxides via X-ray photoelectron spectroscopy. Also, the MTT assay of
this alloy decreased significantly corresponding with an obvious increase of Co release after the firing. For the high Mo-containing
Co–Cr alloy, the surface composition, corrosion resistance, and cell culture response were not significantly changed after
PFM firing. The results suggested that the corrosion resistance and biocompatibility of the low Mo-containing Co–Cr alloy
decreased after PFM firing, whereas the firing process had little effect on the same properties of the high Mo-containing
Co–Cr alloy.
Journal of Materials Science 04/2012; 46(5):1359-1368. · 2.02 Impact Factor
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ABSTRACT: The combined effects of γ-irradiation and cadmium (Cd) exposures on osteoblasts were observed in the present study. Osteoblasts were exposed to γ-irradiation (0.5 Gy) and Cd (0-0.5 μmol/L). Cell viability, alkaline phosphatase (ALP) activity, mineralization ability, cell apoptosis and genes expression of ALP, osteocalcin (OC) and caspase 3 were observed. Low concentrations of Cd exposure had no obvious influence on cell viability, ALP activity and apoptosis. However, low levels of Cd exposure combined with γ-irradiation induced more toxic effects on osteoblasts than those treated with Cd or irradiation alone. High concentrations of Cd combined with irradiation exposure induced more significant inhibition in cell viability, ALP activity and mineralization ability than those exposed to Cd or irradiation alone. Meanwhile, OC and ALP mRNA expression of cells treated with Cd combined with irradiation were down-regulated more significantly than those treated with Cd or irradiation alone. Cd combined with γ-irradiation could obviously enhance osteoblast apoptosis and up-regulated caspase 3 mRNA expression compared with those treated with Cd or irradiation alone. This study indicated that ionizing irradiation can enhance Cd toxic effects on osteoblast viability and differentiation and apoptosis may play an important role in this progress.
Environmental toxicology and pharmacology. 12/2011; 33(2):149-57.
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ABSTRACT: Recently, TiO(2) nanotube layers are widely used in orthopedics and dental applications because of their good promotion effect on bone cells. Furthermore, peptide sequences such as arginine-glycine-aspartic acid are used to modify Ti implant for binding to cell surface integrins through motif. In this study, a cellular adhesive peptide of arginine-glycine-aspartic acid-cysteine (RGDC) was immobilized onto anodized TiO(2) nanotubes on Ti to examine its in vitro responses on rat bone marrow stromal cells (BMSCs). Materials were characterized by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy techniques. High-resolution C1s scans suggested the presence of RGDC on the surface and SEM images confirmed the nanotubes were not destroyed after modification. BMSCs adhesion and osteogenic gene expression were detected in TiO(2) nanotube layers with and without RGDC modification by fluorescence microscopy, confocal laser scanning microscopy, SEM, and realtime polymerase chain reaction (Real-time PCR). Results showed that the TiO(2) nanotube layers immobilized with RGDC increased BMSCs adhesion compared to nonfunctionalized nanotubes after 4 h of cultivation. Furthermore, the osteogenic gene expression of BMSCs was dramatically enhanced on the TiO(2) nanotube layers immobilized with RGDC (10 mM) compared to the TiO(2) nanotube layers immobilized with RGDC (1 mM) and non-functionalized anodized Ti. Our results from in vitro study provided evidence that Ti anodized to possess nanotubes and then further functionalized with RGDC should be further studied for the design of better biomedical implant surfaces.
Journal of Materials Science Materials in Medicine 12/2011; 23(2):527-36. · 2.32 Impact Factor
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ABSTRACT: Low level of cadmium exposure may have direct effects on bone. But the probable mechanism is far from clarified. Using a co-culture system, the present study investigated the effects of low level of cadmium exposure on osteoclast differentiation in the presence of osteoblasts. Primary osteoblasts were isolated from calvarial bone of newborn Sprague Dawley rats. Primary osteoblasts and RAW264.7 cells were exposed to cadmium (0-60 nmol/l) in a co-culture system. Then, osteoblast viability was observed by MTT (3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide) assay. Osteoclast formation and tartrate-resistant acid phosphatase 5b levels were determined by tartrate-resistant acid phosphatase staining and enzyme-linked immunosorbent assay. Osteoprotegerin and receptor activator of NF-kB ligand mRNA expression in osteoblasts were studied via reverse transcription polymerase chain reaction. Viability of osteoblast was obviously decreased by Cd exposure (P < 0.05). Cadmium significantly stimulated the formation of osteoclasts in co-culture system (7.5-60 nmol/l) compared with the control. The levels of tartrate-resistant acid phosphatase 5b in RAW264.7 cells co-cultured with osteoblasts were significantly enhanced by cadmium exposure compared with that without cadmium. The mRNA expression of receptor activator of NF-kB ligand was upregulated by cadmium at 15 and 60 nmol/l. But cadmium had no obvious influence on osteoprotegerin mRNA expression. This data suggested that osteoblasts might be involved in the progress of cadmium effects on osteoclasts.
Biological trace element research 11/2011; 146(3):349-53. · 1.92 Impact Factor
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ABSTRACT: This study describes a nose prosthetic rehabilitation using computer-aided design and manufacturing (CAD-CAM) technology after facial disfigurement because of a total rhinectomy.
A patient with a total rhinectomy was scheduled for a nasal prosthesis. Based on the 3-D model of the patient's face reconstructed with the CT data, a four-piece mould for the nasal prosthesis was prototyped using a CAD-CAM procedure. Conventional silicone was processed with this physical mould to fabricate the definitive nasal prosthesis.
A silicone nasal prosthesis was manufactured. The size, shape, and cosmetic look of the prosthesis were satisfactory and matched the nasal defect area well.
The protocol presented herein illustrates favorable clinical treatment outcomes in the prosthetic rehabilitation after a total rhinectomy by means of CAD-CAM technology.
Supportive Care in Cancer 07/2011; 19(7):1055-9. · 2.09 Impact Factor
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ABSTRACT: The mechanism of cadmium effects on bone is not fully understood. In this study, we investigated the effects of cadmium on osteoclasts differentiation and the probable mechanism. RAW264.7 cells were exposed to cadmium (0-60 nmol/L) in the presence or absence of receptor-activated nuclear factor κ B ligand (RANKL) for 5 days. Then, the viability, tartrate-resistant acid phosphatase (TRAP) activity and the formation of TRAP positive multinucleated osteoclasts were observed. Receptor activator of nuclear factor κ B (RANK), tumor necrosis factor receptor associated factor 6 (TRAF6), c-src, c-fos, fos-related antigen 1 (Fra1) expression were determined by reverse transcription polymerase chain reaction. Cadmium increased TRAP activity (20-40%) and TRAP positive cell formation in the presence of RANKL, but had no obvious influence on them without RANKL. RANK, TRAF6, Fra1, c-src and c-fos (at 15-30 nmol/L) expression were enhanced (30-70%) by cadmium in the presence of RANKL, but cadmium had little influence on them in the absence of RANKL. This study demonstrated that cadmium could induce differentiation of osteoclasts precursor into osteoclasts in the presence of RANKL. Even though the changes of gene expression were small, RANKL/RANK and downstream genes may play an important role in cadmium effects on osteoclasts.
Food and chemical toxicology: an international journal published for the British Industrial Biological Research Association 06/2011; 49(9):2392-7. · 2.99 Impact Factor
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ABSTRACT: To investigate the variation of the corrosion resistance of anodized oxidation film on titanium by electrochemical methods.
TiO2 nanotube layer was formed on Ti surface by anodization. The morphology was observed with scanning electron microscope (SEM) and the crystal phase was analyzed using X-ray diffraction(XRD) before and after annealing. Polarization curves were examined by electrochemical methods.
Titanium oxide nanotubes with 80 nm diameter and 400 nm length was seen on Ti after anodization. The annealing nanotubes was anatase crystalline phase by X-ray diffraction analysis. The self-corrosion potential and break-down potential of smooth Ti were significantly lower than TiO2 nanotubes by anodization (P < 0.05). The self-corrosion current and passived current were significantly higher than TiO2 nanotubes by anodization (P < 0.05). Annealing improved the corrosion resistance of anodized oxidation film on titanium.
The results of electrochemical examinations indicate that the TiO2 nanotubes by anodization increases the corrosion resistance of titanium.
Hua xi kou qiang yi xue za zhi = Huaxi kouqiang yixue zazhi = West China journal of stomatology 04/2011; 29(2):203-5.
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ABSTRACT: Titanium oxide nanotubes prepared by anodization have received considerable attention in the biomaterials domain. The objective of this study was to demonstrate the electrochemical behavior of different diameter TiO(2) nanotube layers on titanium in phosphate buffered saline (PBS) and Dulbecco's minimum essential medium+10% fetal calf serum (D-FCS) using open circuit potentials (OCP), electrical impedance spectroscopy (EIS), and a potentiodynamic polarization test. The results showed that the nanotubes had higher OCP, higher resistance of the inter barrier layer (R(b)), and lower I(pass) in the two test solutions compared to the smooth Ti, especially the 30 nm diameter nanotubes. The corrosion resistance of the nanotubes in D-FCS was higher than in PBS because of protein adsorption from the D-FCS solution as suggested by scanning electron microscope (SEM) images. In addition, protein aggregates of 30 nm diameter nanotubes caused the model of EIS spectra to transform from two-layer to three-layer. The corrosion behavior of the nanotubes for use as a dental implant material is discussed.
Colloids and surfaces. B, Biointerfaces 03/2011; 84(2):400-5. · 2.60 Impact Factor
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ABSTRACT: This study evaluated the corrosion behaviour and surface properties of a commercial cobalt-chromium (Co-Cr) alloy and two nickel-chromium (Ni-Cr) alloys [beryllium (Be)-free and Be-containing] before and after a simulated porcelain-firing process. Before porcelain firing, the microstructure, surface composition and hardness, electrochemical corrosion properties, and metal-ion release of as-cast alloy specimens were examined. After firing, similar alloy specimens were examined for the same properties. In both as-cast and fired conditions, the Co-Cr alloy (Wirobond C) showed significantly more resistance to corrosion than the two Ni-Cr alloys. After firing, the corrosion rate of the Be-free Ni-Cr alloy (Stellite N9) increased significantly, which corresponded to a reduction in the levels of Cr, molybdenum (Mo), and Ni in the surface oxides and to a reduction in the thickness of the surface oxide film. The corrosion properties of the Co-Cr alloy and the Be-containing Ni-Cr alloy (ChangPing) were not significantly affected by the firing process. Porcelain firing also changed the microstructure and microhardness values of the alloys, and there were increases in the release of Co and Ni ions, especially for Ni from the Be-free Ni-Cr alloy. Thus, the corrosion rate of the Be-free Ni-Cr alloy increased significantly after porcelain firing, whereas the firing process had little effect on the corrosion susceptibility of the Co-Cr alloy and the Be-containing Ni-Cr alloy.
European Journal Of Oral Sciences 02/2011; 119(1):93-101. · 1.88 Impact Factor
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ABSTRACT: With the help of electrochemical impedance spectroscopy (EIS), the purpose of the study was to investigate the corrosion resistance of CoCr alloys ,NiCr alloys and commercially pure Ti(cp Ti) in the artificial saliva(AS).
With the EIS, a test was made on the three alloys/metals in the AS (See Bode plot and Nyquist plot). And then, an analysis was made on what was known in the test by the software of ZSimpWin, after which the corrosion resistance of the alloys/metals was evaluated against the parameters of equivalent circuit [R(CR)].
In the Nyquist plot, the capacitance arc radius was in the sequence of cp Ti>CoCr>NiCr. From the Bode plot, an one time constant was able to be obtained. That was the capacitor layer. According to the equivalent circuit[R(CR)], there was no significant difference in the capacitor layer of the three alloys/metals. And the sequence of the impedance value of the three alloys/metals was cp Ti>CoCr>NiCr.
The EIS results suggest that the three alloys/metals have a great corrosion resistance with cp Ti having the highest corrosion resistance and that CoCr alloys is better than NiCr alloys in the corrosion resistance. Supported by Research Fund of Science and Technology Commission of Shanghai Municipality (Grant No.08DZ2271100) and Shanghai Leading Academic Discipline Project(Grant No.T0202).
Shanghai kou qiang yi xue = Shanghai journal of stomatology 04/2010; 19(2):168-72.
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ABSTRACT: It is well known that the growth of osteoblast cultured on titanium with nanotube layers can be significantly increased compared to unanodized surfaces. In the current study, the corrosion behavior of titanium with nanotube layers was studied in naturally aerated Hank's solution using open circuit potentials (OCP), electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization tests. The electrochemical results indicated that TiO2 nanotube layers on titanium showed a better corrosion resistance in simulated biofluid than that of smooth-Ti. The OCP, corrosion rate (I(corr)), passive current density (I(pass)) and the oxygen evolution potential (E(o)) were significantly influenced by titanium oxide nanotube layers acquired by anodization. The anatase nanotube layer showed higher OCP and smaller current density than the amorphous nanotube layer. EIS analysis showed that the annealing had a significant effect on the corrosion resistance of the outer tube layer (R(t)), but little effect on the corrosion resistance of the inter-barrier layer (R(b)) for nanotube layers. The results suggested that titanium with TiO2 nanotube layers has an adequate electrochemical behavior for use as a dental implant material.
Biomedical Materials 12/2009; 4(6):065012. · 2.16 Impact Factor
