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.

The structure of blood-tumor barrier and distribution of chemotherapeutic drugs in non-small cell lung cancer brain metastases.

BACKGROUND: Brain metastasis is an important cause of increased mortality in patients with non-small cell lung cancer (NSCLC). In brain metastasis, the blood-brain barrier (BBB) is frequently impaired, forming blood-tumor barrier (BTB). The efficacy of chemotherapy is usually very poor. However, the characteristics of BTB and the impacts of BTB on chemotherapeutic drug delivery remain unclear. The present study investigated the structure of BTB, as well as the distribution of routine clinical chemotherapeutic drugs in both brain and peripheral tumors. METHODS: Bioluminescent image was used to monitor the tumor load after intracranial injection of lung cancer Lewis cells in mice. The permeability of BBB and BTB was measured by fluorescent tracers of evans blue and fluorescein sodium. Transmission electron microscopy (TEM), immunohistochemistry and immunofluorescence were performed to analyze structural differences between BBB and BTB. The concentrations of chemotherapeutic drugs (gemcitabine, paclitaxel and pemetrexed) in tissues were assayed by liquid chromatography with tandem mass spectrometry (LC-MS/MS). RESULTS: Brain metastases exhibited increased BTB permeability compared with normal BBB detected by fluorescence tracers. TEM showed abnormal blood vessels, damaged endothelial cells, thick basement membranes, impaired intercellular endothelial tight junctions, as well as increased fenestrae and pinocytotic vesicles in metastatic lesions. Immunohistochemistry and immunofluorescence revealed that astrocytes were distributed surrounded the blood vessels both in normal brain and the tumor border, but no astrocytes were found in the inner metastatic lesions. By LC-MS/MS analysis, gemcitabine showed higher permeability in brain metastases. CONCLUSIONS: Brain metastases of lung cancer disrupted the structure of BBB, and this disruption was heterogeneous. Chemotherapeutic drugs can cross the BTB of brain metastases of lung cancer but have difficulty crossing the normal BBB. Among the three commonly used chemotherapy drugs, gemcitabine has the highest distribution in brain metastases. The permeability of chemotherapeutic agents is related to their molecular weight and liposolubility.

The effect of tetrandrine combined with cisplatin on proliferation and apoptosis of A549/DDP cells and A549 cells.

BACKGROUND: Non-small cell lung cancer comprises the majority of lung cancer cases and is insensitive to chemotherapy. Most patients develop drug resistance. Recently, tetrandrine (TET), a bis-benzylisoquinoline alkaloid, was identified as a novel anti-cancer agent. However, the effect of tetrandrine combined with cisplatin on lung cancer has not yet been studied. We aimed to identify a possible synergistic effect between tetrandrine and cisplatin, besides, to investigate the effects of TET in combination with DDP on proliferation and apoptosis in cisplatin-resistant and cisplatin-sensitive A549 cell lines, and to study the underlying mechanism. METHODS: Cell viability was confirmed with CCK8 assays, and the IC50 values for each treatment group were calculated. The synergistic interaction of these drugs was evaluated using an isobolographic analysis. Proliferation was assessed by EDU staining. Hoechst staining and flow cytometry were used to assess apoptosis. Apoptosis- and autophagy-associated proteins were analyzed by western blot. Transmission electron microscopy was used to detect autophagy, RFP-GFP-LC3 lentivirus was used to perform autophagic flux assay. RESULTS: Tetrandrine and cisplatin exerted synergistic cytotoxic effects on both cisplatin-resistant and cisplatin-sensitive A549 cell lines. The combination of tetrandrine and cisplatin induced apoptosis and inhibited proliferation in a synergistic manner. The formation of autophagosomes was evident by transmission electron microscopy. The autophagic flux of combination treatment was increased. CONCLUSIONS: Tetrandrine synergized with cisplatin to reduce the viability of cisplatin-resistant and cisplatin-sensitive A549 cells, tetrandrine could reverse the resistance of A549 cells to cisplatin. Tetrandrine combined with cisplatin could induce autophagy. Therefore, tetrandrine is a potent autophagy agonist and may be a promising drug for the treatment of non-small cell lung cancer.