Pneumomediastinum and subcutaneous emphysema secondary to dental extraction: Two case reports.

BACKGROUND: Dental extraction is a common operation in oral surgery and is usually accompanied by pain, swelling, and local infection. The application of high-speed air turbines increases the comfort of alveolar surgery and makes it more minimally-invasive. However, high-speed gas can enter the subcutaneous tissue of the face and neck or even the chest and mediastinum, which is a serious iatrogenic complication. CASE SUMMARY: We describe two cases of severe subcutaneous and mediastinal emphysema caused by high-speed turbine splitting during dental extraction. The first case involved a 34-year-old man who complained of swelling of the face, mild chest tightness, and chest pain after dental extraction. Computed tomography (CT) scan showed a large amount of gas in the neck, chest wall, and mediastinum. The second case involved a 54-year-old woman who complained of swelling and pain of the neck after dental extraction. CT showed a large amount of gas collected in the neck and mediastinum. Both of them used high-speed turbine splitting during dental extraction. CONCLUSION: High-speed turbine splitting during dental extraction may lead to severe subcutaneous and mediastinal emphysema. Dentists should carefully operate to avoid emphysema. If emphysema occurs, CT can be used to improve the diagnosis. The patient should be informed, and the complications dealt with carefully.

Ethanol supernatant extracts of Gynura procumbens could treat nanodiethylnitrosamine-induced mouse liver cancer by interfering with inflammatory factors for the tumor microenvironment.

ETHNOPHARMACOLOGICAL RELEVANCE: Gynura procumbens (Lour.) Merr, (Family Asteraceae), which serves as both medicine and food in traditional ethnic medicine, has the effects of diminishing inflammation, relieving cough, reducing blood glucose and lipids levels, mitigating hepatotoxicity, and can be used for liver cancer prevention and treatment. AIM OF THE STUDY: To explore how the ethanol extract of Gynura procumbens stems (EEGS) can effectively intervene in the tumor microenvironment, it is necessary to study the mechanism of EEGS on the chemical toxicant nanodiethylnitrosamine (nanoDEN) that induces liver cancer. MATERIALS AND METHODS: EEGS contains large quantities of caffeoylquinic acid (CAC) and non-caffeoylquinic acid (n-CAC), which can be separated by high-performance liquid chromatography. The liver cancer model that was induced by the chemical toxin, nanoDEN, was used to clarify the effective mechanism for tumor intervention of the EEGS and its active ingredients. RESULTS: (1) after interventions with the four drugs on liver cancer, the tumor nodules were obviously reduced and inflammation levels improved. (2) The immunohistochemical staining results showed that both the EEGS and its active ingredients could significantly reverse the abnormal changes in inflammation, proliferation, aging and hypoxia-related proteins in mouse liver tissues that were caused by nanoDEN. (3) Real-time PCR results showed that compared with the nanoDEN group, the expression levels of inflammatory, fatty, and fibrosis-related factors in each group after drug intervention were decreased. (4) The transmission electron microscopy measurements showed that the EEGS significantly reversed the nanostructure changes in hepatocytes that were induced by nanoDEN. CONCLUSION: The EEGS component of Gynura procumbens is effective in preventing and treating liver cancer by interfering with the inflammatory microenvironment during oncogenesis induced by nanoDEN.

Bone marrow mesenchymal stem cells induce M2 microglia polarization through PDGF-AA/MANF signaling.

BACKGROUND: Bone marrow mesenchymal stem cells (BMSCs) are capable of shifting the microglia/macrophages phenotype from M1 to M2, contributing to BMSCs-induced brain repair. However, the regulatory mechanism of BMSCs on microglia/macrophages after ischemic stroke is unclear. Recent evidence suggests that mesencephalic astrocyte-derived neurotrophic factor (MANF) and platelet-derived growth factor-AA (PDGF-AA)/MANF signaling regulate M1/M2 macrophage polarization. AIM: To investigate whether and how MANF or PDGF-AA/MANF signaling influences BMSCs-mediated M2 polarization. METHODS: We identified the secretion of MANF by BMSCs and developed transgenic BMSCs using a targeting small interfering RNA for knockdown of MANF expression. Using a rat middle cerebral artery occlusion (MCAO) model transplanted by BMSCs and BMSCs-microglia Transwell coculture system, the effect of BMSCs-induced downregulation of MANF expression on the phenotype of microglia/macrophages was tested by Western blot, quantitative reverse transcription-polymerase chain reaction, and immunofluorescence. Additionally, microglia were transfected with mimics of miR-30a*, which influenced expression of X-box binding protein (XBP) 1, a key transcription factor that synergized with activating transcription factor 6 (ATF6) to govern MANF expression. We examined the levels of miR-30a*, ATF6, XBP1, and MANF after PDGF-AA treatment in the activated microglia. RESULTS: Inhibition of MANF attenuated BMSCs-induced functional recovery and decreased M2 marker production, but increased M1 marker expression in vivo or in vitro. Furthermore, PDGF-AA treatment decreased miR-30a* expression, had no influence on the levels of ATF6, but enhanced expression of both XBP1 and MANF. CONCLUSION: BMSCs-mediated MANF paracrine signaling, in particular the PDGF-AA/miR-30a*/XBP1/MANF pathway, synergistically mediates BMSCs-induced M2 polarization.

Raman Spectroscopic Study of the Structure of CaO-SiO2-Al2O3-Based Flux.

Due to the [Al] reaction with the CaO-SiO2-based mold flux used in the high-Al steels continuous casting processes, decreasing the SiO2 content is decreased and the Al2O3 content in mold flux is increased, thus converting the original CaO-SiO2-based mold flux into a CaO-SiO2-Al2O3-based mold flux. This conversion of the mold fluxes can cause the problem of high-Al steels continuous casting. Hence, study on the structural characteristics of the CaO-SiO2-Al2O3- based mold flux can provide fundamental data to design optimum fluxes for high Al-containing steels. In this paper, the structural characteristics of the CaO-SiO2-based and CaO-SiO2-Al2O3-based flux were studied by Raman spectroscopy. The results have shown that, the CaO-SiO2-based flux was the silicate structure whose main micro-structure units were Q0, Q1, Q2 and Q3. The network breakers prefer to depolymerize the silicate network in CaO-SiO2-Al2O3-based flux. While the CaO-SiO2-Al2O3-based flux with low SiO2 content, the [AlO4] tetrahedron was entered the silicate network and the melt converted into the aluminosilicates structure, the formation of Al-O-Al linkages and Si-O-Al linkages increased the degree of disorder of network. The results of Li2O replace Na2O and CaO replace MgO have shown that the ions will influence the formation of [AlO4] tetrahedron linkages. CaF2 replace CaO shown that the polymerization degree of mold slag decreased first, and then increased with the content of CaF2 more than 13 mol%. So, the influences of the ions type and the ions content on the structure were both need considered while designing the CaO-SiO2-Al2O3-based flux.