The modification of meteorological factors on the relationship between air pollution and periodontal diseases: an exploration based on different interaction strategies.

We aimed to characterize the association between air pollutants exposure and periodontal diseases outpatient visits and to explore the interactions between ambient air pollutants and meteorological factors. The outpatient visits data of several large stomatological and general hospitals in Hefei during 2015-2020 were collected to explore the relationship between daily air pollutants exposure and periodontal diseases by combining Poisson's generalized linear model (GLMs) and distributed lag nonlinear model (DLNMs). Subgroup analysis was performed to identify the vulnerability of different populations to air pollutants exposure. The interaction between air pollutants and meteorological factors was verified in both multiplicative and additive interaction models. An interquartile range (IQR) increased in nitrogen dioxide (NO2) concentration was associated with the greatest lag-specific relative risk (RR) of gingivitis at lag 3 days (RR = 1.087, 95% CI 1.008-1.173). Fine particulate matter (PM2.5) exposure also increased the risk of periodontitis at the day of exposure (RR = 1.049, 95% CI 1.004-1.096). Elderly patients with gingivitis and periodontitis were both vulnerable to PM2.5 exposure. The interaction analyses showed that exposure to high levels of NO2 at low temperatures was related to an increased risk of gingivitis, while exposure to high levels of NO2 and PM2.5 may also increase the risk of gingivitis and periodontitis in the high-humidity environment, respectively. This study supported that NO2 and PM2.5 exposure increased the risk of gingivitis and periodontitis outpatient visits, respectively. Besides, the adverse effects of air pollutants exposure on periodontal diseases may vary depending on ambient temperature and humidity.

Association of urinary heavy metal combined exposure with periodontitis among US adults from NHANES 2011-2014.

Some heavy metals are associated with periodontitis; whereas most of these associations have focused on individual metal, there are no specific studies on the effects of combined heavy metal exposure on periodontitis. We conducted an analysis on the association between urinary heavy metal exposure and periodontitis in participants aged 30 years and older using multiple logistic regression and Bayesian kernel machine regression (BKMR). This analysis was performed on data from the National Health and Nutrition Examination Survey from 2011 to 2014. The study found that using logistic regression, the 4th quartile of urinary lead and molybdenum and the 3rd quartile of urinary strontium were positively associated with periodontitis compared to the reference quartile after adjusting for covariates. Odds ratio (OR) with 95% confidence interval (CI) was 1.738 (1.069-2.826), 1.515 (1.025-2.239), and 1.498 (1.010-2.222), respectively. The 3rd and 4th quartiles of urinary cobalt were negatively associated with periodontitis, and their ORs and 95% CIs were 0.639 (0.438-0.934) and 0.571 (0.377-0.964), respectively. The BKMR model showed that urinary barium, lead, and molybdenum were positively associated with periodontitis in a range of concentrations and urinary cobalt, manganese, tin, and strontium were negatively correlated with periodontitis. Furthermore, the overall association between urinary heavy metals and periodontitis was positive. Our study provides evidence for an association between exposure to multiple urinary heavy metals and periodontitis. However, further longitudinal studies are needed to explore the specific mechanisms involved.

Delivery of Rapamycin by Liposomes Synergistically Enhances the Chemotherapy Effect of 5-Fluorouracil on Colorectal Cancer.

BACKGROUND: Rapamycin is a promising agent for treating tumors, but clinical applications of rapamycin are limited due to its poor water solubility and low bioavailability. This paper constructs a liposome delivery system for rapamycin to improve the effect in treating colorectal cancer. METHODS: We prepared the rapamycin liposomes using the ethanol injection method. The cellular uptake and biodistribution were detected by LC-MS and in vivo imaging system. MTT assay, transwell migration experiment, flow cytometry, and Western blot analysis evaluated the antitumor effect of rapamycin liposomes in vitro. Furthermore, HCT-116 tumor-bearing mice were used to assess the therapeutic efficacy of rapamycin liposomes in vivo. RESULTS: The prepared rapamycin liposomes had a particle size of 100±5.5 nm and with a narrow size distribution. In vitro cellular uptake experiments showed that the uptake of rapamycin liposomes by colorectal cells was higher than that of free rapamycin. Subsequently, in vivo imaging experiments also demonstrated that rapamycin liposomes exhibited higher tumor accumulation. Therefore, the ability of rapamycin liposomes to inhibit tumor proliferation, migration and to induce tumor apoptosis is superior to that of free rapamycin. We also demonstrated in vivo good antitumor efficacy of the rapamycin liposomes in HCT-116 xenograft mice. In addition, rapamycin liposomes and 5-FU can synergistically improve the efficacy of colorectal cancer via the Akt/mTOR and P53 pathways. CONCLUSION: Collectively, rapamycin liposomes are a potential treatment for colorectal cancer, as it not only improves rapamycin's antitumor effect but also synergistically enhances 5-FU's chemotherapy effect.

Survival and differentiation of neuroepithelial stem cells on chitosan bicomponent fibers.

Chitosan is a popular biomaterial used in tissue engineering. Fibers of chitosan could provide a favorable anatomical substrate for cell growth which provides a promising application for axonal regeneration during peripheral injury. Neuroepithelial stem cells (NEPs) are the most primitive neural stem cells with multipotential for neuronal and glia differentiation. To assess the biocompatibility between NEPs and chitosan fibers, and to explore whether the NEPs have the ability to differentiation on chitosan fibers, NEPs were harvested from the neural tube and seeded on chitosan fibers in in vitro culture. The biocompatibility of chitosan fibers was tested by MTT assays. The growth and survival were observed by light and scanning electronic microscope at different times in culture. And, the differentiation of NEPs was examined by immunocytochemical staining. The results indicated that NEPs could grow on the chitosan fibers and attach firmly to the surface of fibers. On chitosan fibers, NEPs could differentiate into neurons and glia. Our study demonstrated that chitasan fibers had a good biocompatibility with NEPs which affords a potential alternative for the repair of peripheral nerve injury.

[Effect of decompression combined with curettage and autogenous bone cement implantation on large cysts of the jaw].

Decompression and curettage can result are effective as treatments for large jaw cysts, which are common diseases in the clinic. Based on a treatment used in a previous study, this paper proposes a "three-step method" to treat large jaw cyst and repair the bone defect by decompression, curettage, and autologous dental bone powder implantation. This paper introduces the processes and key points of the operation involved in the abovementioned method.

Ethylene polymerization by new chromium catalysts based on carborane [SSO] ligands.

Tridentate carborane [S, S, O] ligands 2a-2b [(HOC6H2R2-4,6)(CH2)SC(B10H10)C(Ph)2P=S, R = (t)Bu (2a), R = Me (2b)] were synthesized and characterized. Reaction of CrCl3(THF)3 with the sodium salts of ligands 2a and 2b afford six-coordinated chromium complexes 3a and 3b. EXAFS spectroscopy performed on complex 3a to describe the coordination chemistry of ligand 2a around chromium center. DFT calculations were also performed on complex 3a to analyze the structure. The preliminary screening results revealed that six-coordinated chromium complexes 3a-3b displayed good catalytic activities towards ethylene polymerization in the presence of modified methylaluminoxane. The effect of polymerization parameters such as cocatalyst, reaction temperature, ethylene pressure, and reaction time on polymerization behavior were investigated in detail. The polymer obtained from this homogeneous catalytic reaction has a fibroid morphology.