Quantitative assessment of aerosol contamination generated during tooth grinding with a speed-increasing handpiece.

OBJECTIVES: Tooth grinding produces a significant amount of aerosol particles. The aim of this study was to quantitatively assess particle contamination produced from tooth grinding with a speed-increasing handpiece across a real-world clinical setting. METHODS: All molar crowns were pretreated into cylinders with a uniform size. A novel computer-assisted numerical control system was used to parametrically study the bur speed: from 20,000 (20 K) to 200 K rpm at 20 K rpm intervals. 5-minute tooth grinding was performed in triplicate at each speed setting. Three online real-time particle counters (ORPC; TR-8301, TongrenCo.) were placed at 3 positions (0.5, 1, and 1.5 m) to evaluate particle production. All experimental instruments were controlled remotely. The data obtained were statistically analyzed using descriptive statistics and non-parametric tests (Scheirer-Ray-Hare and Kruskal-Wallis/ Dunn-Bonferroni tests, p < 0.05). RESULTS: The concentration level of aerosol particles production during the grinding experiment was elevated above the control group for all conditions, and increased with bur speed at any location (the maximum peak, reaching 5.59 × 107 particles/m3, at 200 K and 1 m), with differences between conditions. The effect of speed on the increment of particles across different channels compared to the control group was statistically significant among locations (p < 0.001). CONCLUSIONS: Statistically significant particle contamination was produced using a speed-increasing handpiece, but the contamination level for each experimental condition was reduced to baseline within 30 min, and most particles with a diameter greater than 1üm produced at low speeds (80 K or lower) tended to settle within 1 m. CLINICAL RELEVANCE: Our study suggested that the use of a speed-increasing handpiece below 80 K and 30 min of fallow time may lead to an adequate reduction in the health effects of particle contamination.

Efficacy of oral colon-specific delivery capsule of low-molecular-weight heparin on ulcerative colitis.

Low-molecular-weight heparin has the potential for the treatment of ulcerative colitis, and targeted drug delivery to the colon is important for topical treatment of this disease, so low-molecular-weight heparin oral colon-specific delivery capsule was prepared, and the in vitro and in vivo drug release behavior was investigated. The macroscopical and histological scoring systems, wet colon mass index and myeloperoxidase activity were assessed to evaluate the efficacy of the capsule after administered orally to experimental colitis mice. Serum levels, including tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and a link factor of blood coagulation and inflammation factor Xa (FXa) were assayed by enzyme-linked immunosorbent assay. The expression of Musashi-1 (as an intestinal stem cell marker) in the colons was assessed by immunohistochemical analysis. The in vitro and in vivo drug release studies clearly indicated that the specific coated capsules were capable of protecting low-molecular-weight heparin from releasing in stomach and small intestine, while specifically delivering at colon. The oral colon-specific delivery capsule of low-molecular-weight heparin could attenuate macroscopic and histological features of colitis. The results showed that low-molecular-weight heparin oral colon-specific delivery capsule significantly decreased the serum levels of TNF-α, IL-6 as well as FXa, while increased the expression of Musashi-1 in colon compared with acetic acid-induced ulcerative colitis model group. The results showed that low-molecular-weight heparin oral colon-specific delivery capsule had the potential for treatment of inflammatory bowel disease.

The relationship between the structure of dermatan sulfate derivatives and their antithrombotic activities.

To study the relationship between the structure of dermatan sulfate (DS) derivatives and their anti-thrombotic activities, DS-derived oligosaccharides (with different structures and relative molecular weight (M(r))) were prepared, and the effects of the DS-derived oligosaccharides on the activities of heparin cofactor II (HCII), activated protein C (APC), blood platelet, and vascular endothelial cells were studied. The major disaccharides of DS and polysulfated dermatan sulfate (PSDS) were IdoA-1-->3-GalNAc-4-OSO(3) and IdoA-2OSO(3)-1-->3-GalNAc4, 6-diOSO(3), respectively. The results showed that the consequence of the thrombotic inhibitory effects of DS and its derivatives were as follows: PSDS>low molecular weight polysulfated dermatan sulfate (LPSDS)>DS. Both DS and PSDS inhibited platelet aggregation in the concentration-dependent manner, and the IC(50) value of DS and PSDS is 12.7+/-1.3 and 28.6+/-0.9 mg/mL, respectively. DS oligosaccharides (DSOSs) and PSDS oligosaccharides (PSDSOSs) both significantly inhibited P-selectin expression on platelet surface (P<0.01), while DSOSs have no different effect compared with PSDSOSs. DSOSs and PSDSOSs significantly enhanced the activity of HCII in inhibiting thrombin in the plasma. The most active PSDSOS was PSDSOS(1) with M(r) of 4959, which enhanced the HCII activity by 91% (P<0.01). The experiments on APC activity showed that DS and its derivatives enhanced APC activity. The most active PSDSOS was PSDSOS(3) with M(r) of 2749, which enhanced the APC activity to 331+/-27% (P<0.01). DSOSs and PSDSOSs enhanced tissue plasminogen activator (t-PA) activity and reduced the plasminogen activator inhibitor (PAI) activity from cultured human umbilical vein endothelial cells (HUVEC), resulting in the ratio of t-PA/PAI going up. PSDSOSs which have the same M(r) as DSOSs produced more active effects in above assays, except for platelet aggregation.

Effects of dermatan sulfate derivatives on platelet surface P-selectin expression and protein C activity in blood of inflammatory bowel disease patients.

AIM: To investigate the effect of dermatan sulfate (DS) derivatives on platelet surface P-selectin expression and blood activated protein C (APC) activity in patients with inflammatory bowel disease (IBD), and to clarity the anti-inflammatory mechanism of DS derivatives. METHODS: Dermatan sulfate (DS) was sulfated with chlorosulfonic acid to prepare polysulfated dermatan sulfate (PSDS). The major disaccharides of DS and PSDS were determined by 1H nuclear magnetic resonance spectroscopy (1H-NMR) and 13C-NMR. Both DS and PSDS were depolymerized with hydrogen peroxide. The fragments were separated by gel filtration chromatography. The effects of DS derivatives on P-selectin expression were assayed by ELISA method, and blood APC activity was assayed by the synthetic chromogenic substrate method. RESULTS: The major disaccharides of DS and PSDS were IdoA-1-3-GalNAc-4-SO3 and IdoA-2SO3-1-3-GalNAc4, 6-diSO3, respectively. Compared with the adenosine diphosphate stimulated group and IBD control group, DS and its derivatives all had significant inhibitory effects on P-selectin expression (P<0.01), but there was no difference between DS-derived oligosaccharides (DSOSs) and PSDS-derived oligosaccharides (PSDSOSs). The experiments on APC activity showed that DS and its derivatives all enhanced APC activity. The most active DSOS was the one with a relative molecular weight (Mr) of 4,825, which enhanced the APC activity from 106.5+/-11.5% to 181.8+/-22.3% (P<0.01). With the decrease of Mr, the activity of DSOSs decreased gradually. The effect of PSDS on APC activity enhancement was more significant than that of DS, and the APC activity was raised to 205.2+/-22.1% (P<0.01). All the PSDSOSs were more active than DSOSs on the basis of comparable Mr. With the decrease of Mr, the activity of PSDSOSs increased gradually, and the most active PSDSOS was PSDSOS3 with Mr of 2,749, which enhanced the APC activity to 331.2+/-27.8% (P<0.01), then the activity of PSDSOSs decreased gradually. CONCLUSION: DS and its derivatives can significantly inhibit P-selectin expression on platelet surface, but the effect has no correlation with DS molecular mass and sulfation. The effect of DS or its derivatives on APC activity at molecular level involves complex mechanisms that depend on the molecular mass, the degree of sulfation, and the heterogeneous composition of DS. On the same molecular size, the higher the degree of DS sulfation, the more significant the effect on enhancing APC activity.

Inhibitory effect of heparin-derived oligosaccharides on secretion of interleukin-4 and interleukin-5 from human peripheral blood T lymphocytes.

AIM: To investigate the inhibitory effect of heparin-derived oligosaccharides (Oligs) on secretion of interleukin-4 (IL-4) and interleukin-5 (IL-5) from human peripheral blood T lymphocytes (PBTLs). METHODS: Oligs were prepared by three different heparin depolymerization methods and separated by gel filtration chromatography. PBTLs from ten adult patients with allergic eosinophilic gastroenteritis were treated with phytahematoagglutinin (PHA) and Oligs. The supernatants from the cell culture of PBTLs were harvested and subjected to the determination of IL-4 and IL-5 contents by ELISA method. RESULTS: At the concentration of 5 microg/mL, Oligs with different Mr had different effects on the secretion of IL-4 and IL-5. The tetrasaccharide with Mr of 1,142, produced by depolymerizing heparin with hydrogen peroxide, had the strongest inhibitory effect on the secretion of IL-4. It decreased the IL-4 content from 375.6+/-39.2 ng/L (PHA group) to 12.5+/-5.7 ng/L (P<0.01). The hexasaccharide with Mr of 1,806, produced by depolymerizing heparin with beta-elimination method, had the strongest inhibitory effect on the secretion of IL-5. It decreased the IL-5 content from 289.2+/-33.4 ng/L (PHA group) to 22.0+/-5.2 ng/L (P<0.01). CONCLUSION: The inhibitory activity of Oligs on the secretion of IL-4 and IL-5 from human PBTLs closely depends on their molecular structure, and there may be an essential structure to act as an inhibitor. The most effective inhibitors of IL-4 and IL-5 secretion are tetrasaccharides and hexasaccharides, respectively.