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The gaining popularity of tobacco and nicotine delivery products, such as electronic cigarettes (e-cigarettes) being perceived as relatively safe is of a medical concern. The long-term safety of these new products remains uncertain for oral health. In this study, in vitro effects of e-liquid were assessed in a panel of normal oral epithelium cell lines (NOE and HMK), oral squamous cell carcinoma (OSCC) human cell lines (CAL27 and HSC3), and a mouse oral cancer cell line (AT84) using cell proliferation, survival/cell death, and cell invasion assays. In addition, signaling pathways underlying the pro-invasive activity of e-cigarettes were evaluated by gene and protein expression analysis. We demonstrated that e-liquid promotes proliferation and anchorage-independent growth of OSCC and induces morphological changes associated with enhanced motility and invasive phenotypes. Furthermore, e-liquid-exposed cells express significantly reduced cell viability, regardless of e-cigarette flavour content. At the gene expression level, e-liquid induces changes in gene expression consistent with epithelial to mesenchymal transition (EMT) revealed by reduced expression of cell epithelial markers such as E-cadherin and enhanced expression of mesenchymal proteins like vimentin and B-catenin seen both in OSCC cell lines and normal oral epithelium cells. In summary, the ability of e-liquid to induce proliferative and invasive properties along the activation of the EMT process can contribute to the development of tumorigenesis in normal epithelial cells and promote aggressive phenotype in pre-existing oral malignant cells., (© 2023. The Author(s).)

The training of future physicians should be concurrent with the development of different skills and attitudes. This warrants the need to regularly provide students with opportunities for self-development throughout their academic career. This approach was exemplified in a medical school in the Brazilian Amazon, where students were allowed to play the role of high school teachers. As part of this exercise, they conducted reinforcement classes for high school students to increase the number of university admissions. The medical students were solely responsible for organizing and implementing this project, giving them the opportunity to develop teaching and leadership skills, enhance their understanding of communication and administration and contribute toward the society.

Objective: To evaluate the impact of an aggressive treatment approach using muscle flaps or omentopexy in infections of the sternum and anterior mediastinum following sternotomy on mortality, as compared to that of a conservative treatment approach., Methods: Data were collected prior to, during and after the surgical procedures. Group A (n = 44) included patients submitted to conservative treatment-debridement together with resuture or continuous irrigation with polyvinylpyrrolidone-iodine solutions, or even with second-intention wound healing (retrospective data). Group B (n = 9) included patients in whom infection was not resolved with conservative treatment, and who therefore underwent aggressive treatment (intermediate phase). Group C (n = 28) included patients primarily submitted to aggressive treatment (prospective data)., Results: Postoperative hospital stays were shorter in the patients submitted to aggressive treatment (p < 0.046). There were 7 deaths in group A, 1 in group B, and 2 in group C. However, the classical level of significance of alpha = 0.05 was not reached., Conclusion: Aggressive treatment also proved to be effective when the infection was not resolved with conservative treatment. These findings demonstrate that the proposed treatment provides excellent results.

Objective: The aim of this study was to assess whether the presence of procaine in crystalloid cardioplegic solution increases myocardial protection at the ultra structural level., Methods: Eighteen patients that underwent aortic valve replacement in the Hospital de Clínicas de Porto Alegre over a 10-month period were studied. They were randomly allocated into two groups: group A--eight patients receiving cardioplegia without procaine; group B--ten patients receiving cardioplegia with procaine. Myocardial biopsies were performed in three different periods: 1st--before ischemic arrest, 2nd--at the end of ischemic arrest, and 3rd--15 minutes after reperfusion., Results: The ultra structural analysis comparing the groups in the three moments did not show any statistically significant difference. The mean score in group A at moment I, II and III was 0.1 +/- 0.2; 0.4 +/- 0.3; 0.4 +/- 0.4, and group B 0.2 +/- 0.2; 0.4 +/- 0.3; 0.7 +/- 0.2. Comparative analysis of CK-MB was similar. The spontaneous return to sinus rhythm after aortic declamping in group B occurred in 70% and in group A 12.5% (p=0.024)., Conclusion: Both cardioplegic solutions tested were equally effective in myocardial preservation, and we could not demonstrate at the ultrastructural level any benefit when procaine was added. The spontaneous return to sinus rhythm after aortic declamping was significantly greater when procaine was added.

The objective of the following study was to evaluate antigenicity, malacia and revascularization in glycerin-preserved canine tracheal allografts. Trachea with six cartilage rings (2.4 to 3.1 cm) were distributed in three study groups: autograft (21), allograft (18) and glycerin-preserved (22). We implanted two segments from different groups in the greater omentum of dogs. After 28 days, latex was injected in the canine aorta before the segments were harvested. We evaluated number of sectors with functional vessels, number of vessels dyed in the submucosa, acute arteritis score, incidence of acute rejection, cartilage lesion score, and malacia. The autograft group had a larger number of dyed vessels than the glycerin-preserved group. The autograft group also had a higher average number of quadrants with functional vessels than the allograft group and the glycerin-preserved group. The allograft group had a higher mean score for acute arteritis than the autograft group and more acute rejection than the glycerin-preserved group. The cartilage lesion score did not show any significant difference between groups. Malacia was not observed in any tracheal segment. Overall, the glycerin-preserved tracheal implant had low antigenicity and good rigidity, but showed incomplete revascularization.