LEONARDO KENJI SAKAUE KOYAMA
Projetos de Pesquisa
Unidades Organizacionais
Instituto Central, Hospital das Clínicas, Faculdade de Medicina
5 resultados
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- Who and Where are the University of Sao Paulo Medical School Graduates?(2019) GAMEIRO, Gustavo Rosa; KOYAMA, Leonardo Kenji Sakaue; CRUZ, Ana Luisa Ito Baptista da; CASSENOTE, Alex Jones Flores; GUILLOUX, Aline Gil Alves; SEGURADO, Aluisio Augusto Cotrim; SCHEFFER, Mario CesarOBJECTIVE: To evaluate the impact of a complex-care-based medical school in the context of the Brazilian health care system on students' career choices. METHODS: This was a retrospective cross-sectional study based on medical regulatory organization records. It included records for 7,419 physicians who graduated from FMUSP. Geographic data were analyzed using Kernel maps, and the statistical analysis was performed with SPSS (R) version 24.0. A p-value less than 0.05 was considered significant. RESULTS: Of the 7,419 physicians, 68.6% (95% CI 67.5-69.7) were male, and 20.7% (95% CI 19.8%-21.7%) had no medical specialty, compared to 46.4% nationwide. Internal medicine and surgery-based specialties were more popular, accounting for 39.4% (95% CI 38.3%-40.5%) and 16.8% (95% CI 15.5%-17.6%) of our study group, compared to the Brazilian averages of 25.9% and 13.5%. Our graduates also had a higher probability of staying in Sao Paulo City, especially when born outside the city. CONCLUSION: We believe that FMUSP remains an interesting model for studying the impact of a highly specialized center on the education and career choices of medical students.
- Epithelial-mesenchymal transition related to bone invasion in oral squamous cell carcinoma(2022) VANINI, Jaqueline Vaz; KOYAMA, Leonardo Kenji Sakaue; MATOS, Leandro Luongo de; FIGUEREDO JUNIOR, Jose Martins; CERNEA, Claudio Roberto; NAGANO, Cibele Pidorodeski; COUTINHO-CAMILLO, Claudia Malheiros; HSIEH, Ricardo; LOURENCO, Silvia VanessaIntroduction: Bone invasion is an important prognostic factor in oral squamous cell carcinoma, leading to a lower survival rate and the use of aggressive treatment approaches. Epithelial-mesenchymal transition (EMT) is possibly involved in this process, because it is often related to mechanisms of cell motility and invasiveness. This study examined whether a panel of epithelial-mesenchymal markers are present in cases of oral squamous cell carcinoma with bone invasion and whether these proteins have any relationship with patients' clinical-pathological parameters and prognostic factors. Methods: Immunohistochemical analysis of E-cadherin, twist, vimentin, TGF beta 1, and periostin was performed in paraffin-embedded samples of 62 oral squamous cell carcinoma cases. Results: The analysis revealed that most cases (66%) presented with a dominant tumor infiltrative pattern in bone tissue, associated with lower survival rates, when compared with cases with a dominant erosive invasion pattern (P = 0.048). Twenty-seven cases (43%) expressed markers that were compatible with total or partial EMT at the tumor-bone interface. There was no association between evidence of total or partial EMT and other demographic or prognostic features. E-cadherin-positive cases were associated with tobacco smoking (P = 0.022); vimentin-positive cases correlated with tumors under 4 cm (P = 0.043). Twistexpression was observed in tumors with a dominant infiltrative pattern (P = 0.041) and was associated with the absence of periostin (P = 0.031). Conclusion: We observed evidence of total or partial EMT in oral squamous cell carcinoma bone invasion. The transcription factor twist appears to be involved in bone invasion and disease progression. (C) 2022 The Authors.
- Oral Squamous Cell Carcinoma Bone Invasion: Possible Roles of E-Cadherin in Osteoclastogenesis and Bone Infiltration(2021) KOYAMA, Leonardo Kenji Sakaue; NAGANO, Cibele Pidorodeski; VANINI, Jaqueline Vaz; JR, Jose Martins Figueredo; MATOS, Leandro Luongo de; CERNEA, Claudio Roberto; COUTINHO-CAMILLO, Claudia Malheiros; LOURENCO, Silvia VanessaIntroduction: Squamous cell carcinoma is the most common cancer of the oral cavity. When the tumor invades the bone tissue, the prognostic and survival rates decrease a lot, and the treatment becomes more aggressive, with several damages to the patient and health system. Many of the molecular mechanisms of bone invasion process are not understood yet, but it is already known that one of central processes of tumor evolution - adjacent tissues invasion and metastasis - is a large spectrum of phenotypic changes in epithelial cells to mesenchymal, in a process named as epithelial-mesenchymal transition (EMT). Loss of E-cadherin, an important epithelial cell adhesion protein, is a hallmark of this phenomenon. The objective of this retrospective study is to evaluate the expression of E-cadherin protein, comparing its distribution with clinical characteristics of the patients and possibly relation to EMT. Methods: Sixty-two cases with respective clinical data were analyzed by comparing immunohistochemical, H and E staining, and clinical data, observing the tumor-bone interface (TBI) and the surrounding tumor that had no direct contact with the bone surface (ST). Results: Forty cases were positive for E-cadherin (64%) with a heterogeneous pattern. Statistical analysis showed a significant difference between the presence of E-cadherin expression and tobacco smokers. Also, the equal or weaker protein expression in the ST than TBI is related to a worse overall survival. No statistically significant difference in other prognostic factors was observed. Conclusion: Our results suggest that the tumor cells that interact with the bone tissue could gain molecular changes, like partial EMT and osteoclastogenesis induction, which facilitate their migration and increase the bone resorption, resulting in a worse patient's prognosis.
- Oral Cancer Treatment: Still an Indication for Elective Neck Dissection?(2018) KOYAMA, Leonardo Kenji Sakaue; MATOS, Leandro Luongo; KULCSAR, Marco Aurelio Vamondes; ARAUJO FILHO, Vergilius Jose Furtado de; CERNEA, Claudio RobertoIntroduction: Oral squamous cell carcinoma has a high incidence and, although elective neck dissection is recommended, the removed nodes frequently present without metastasis. This surgical approach causes disabilities and increases possible surgical complications. Objective: To evaluate the possibility of a watchful waiting approach in oral cancer. Methods: We compared 78 patients with clinical and pathological node metastases and their counterparts with pathological node metastases but without evident clinical neck disease. Therefore, we provided a theoretical comparison between the patients who had an elective neck dissection and those who waited until a clinically positive node was evident. Results: The prognostic factor rates were similar between the groups. Their regional recurrence and mortality rates had no statistical differences. Conclusion: A watchful waiting policy could be applied to selected oral cancer patients who can undergo a very close follow-up. This option would be more cost effective and less harmful than elective neck dissection. (C) 2018 S. Karger AG, Basel
- Validation of methodology for assessment of pulmonary function in patients who undergo total laryngectomy(2016) CASTRO, Mario A.; DEDIVITIS, Rogerio Aparecido; SALGE, Joao M.; KOYAMA, Leonardo K.; CERNEA, Claudio Roberto; BRANDAO, Lenine GarciaBackground. In patients submitted to laryngectomy, pulmonary complications may lead to death. A simple method with a standardized extratracheal device for the pulmonary assessment of laryngectomized patients would be very useful. The purpose of this study was to validate the methodology for pulmonary assessment in these patients through the application of an adhesive extratracheal device. Methods. This transversal study included 50 patients who had been submitted to total laryngectomy. Pulmonary tests were used to characterize the presence of respiratory functional limitation. Aiming at evaluating the reproducibility of the performed tests, parameters were used for the acceptance of the tests. A comparison of these parameters was made with 50 tests performed in nonlaryngectomized patients. Results. The total of rejected tests was greater in the control group when compared to the laryngectomized group. Conclusion. The methodology for the assessment of the pulmonary function by using the extratracheal proposed device is reliable, accurate, and reproducible. (C) 2016 Wiley Periodicals, Inc.