CONTEXT AND OBJECTIVE: This study aimed to evaluate different mathematical post-analysis methods of determining lactate threshold in highly and lowly trained endurance runners. DESIGN AND SETTING: Experimental laboratory study, in a tertiary-level public university hospital. METHOD: Twenty-seven male endurance runners were divided into two training load groups: lowly trained (frequency < 4 times per week, < 6 consecutive months, training velocity ≥ 5.0 min/km) and highly trained (frequency ≥ 4 times per week, ≥ 6 consecutive months, training velocity < 5.0 min/km). The subjects performed an incremental treadmill protocol, with 1 km/h increases at each subsequent 4-minute stage. Fingerprint blood-lactate analysis was performed at the end of each stage. The lactate threshold (i.e. the running velocity at which blood lactate levels began to exponentially increase) was measured using three different methods: increase in blood lactate of 1 mmol/l at stages (DT1), absolute 4 mmol/l blood lactate concentration (4 mmol), and the semi-log method (semi-log). ANOVA was used to compare different lactate threshold methods and training groups. RESULTS: Highly trained athletes showed significantly greater lactate thresholds than lowly trained runners, regardless of the calculation method used. When all the subject data were combined, DT1 and semilog were not different, while 4 mmol was significantly lower than the other two methods. These same trends were observed when comparing lactate threshold methods in the lowly trained group. However, 4 mmol was only significantly lower than DT1 in the highly trained group. CONCLUSION: The 4 mmol protocol did not show lactate threshold measurements comparable with DT1 and semi-log protocols among lowly trained athletes.RESUMO CONTEXTO E OBJETIVO: O objetivo do presente estudo é avaliar modelos matemáticos de pós-análise do limiar de lactato em grupos de corredores de longa distância muito ou pouco treinados. TIPO DE ESTUDO E LOCAL: Estudo laboratorial experimental. Hospital Público Universitário Terciário. MÉTODO: Vinte e sete corredores homens foram divididos em: pouco treinados (frequência < 4 vezes por semana, < 6 meses, velocidade ≥ 5,0 minutos/km) e muito treinados (frequência ≥ 4 vezes por semana, ≥ 6 meses, velocidade < 5,0 minutos/km). Os participantes foram submetidos a protocolo de esteira escalonado (1% inclinação) = 1 km/h por fase (4 minutos). Ao fim de cada estágio, análise da "impressão digital" metabolômica foi realizada. O limiar do lactato (i.e. velocidade em que o lactato sanguíneo aumenta exponencialmente) foi medido utilizando-se três métodos: aumento de 1 mmol/l da concentração, concentração absoluta de 4 mmol e método semi-log. ANOVA foi utilizada para comparar os diferentes limiares de lactato e grupos. RESULTADO: Atletas muito treinados apresentaram limiares de lactato maiores que os corredores pouco treinados, independentemente do método de cálculo utilizado. Comparando todos os corredores juntos, as análises de aumento de 1 mmol/l e semi-log não foram d...

Melanoma is a serious public health problem that affects the population of Latin America and is increasing rapidly compared to other types of tumors. The growth or change in this type of tumor is progressive and is in the horizontal and/or vertical direction. Breslow thickness (vertical staging) is the tumor thickness in the dermis where patients with lesion thickness less than 0.75 mm have good prognosis, unlike lesion thickness larger than 3 mm. This stage is classified into T (primary tumor): T0 (with no evidence of primary tumor); Tis (in situ melanoma); T1 (1 mm); T2 (1.01 to 2 mm); T3 (2.01 to 4 mm); and T4 (above 4 mm). Knowing some molecular markers of melanoma is essential for the identification of genetically predisposed individuals, as well as early detection of the disease. Recent works has demonstrated that microRNAs may be involved in modulation of melanoma. Dicer is an essential member of the RNase III family which controls maturation of miRNAs in the cytoplasm from microRNA precursors (pre-miRNAs). The upregulation of Dicer is associated with aggressive features and proliferation of melanoma and no other skin tumors such as carcinomas and sarcoma. In our present study, we found that the knockdown expression of Dicer using the CRISPR/CAS9 in melanoma cell line induced more chemosensitivity to cisplatin and these changes correlated with the downregulation of Dicer. We examined the consequence of Dicer knockdown on melanoma cell proliferation, clonogenic assays, and overall survival. We also compared Dicer in tissue from patients diagnosed with melanoma in different stages with the prognosis of these patients, suggesting that the reduction in Dicer expression is associated with melanoma progression. Considering the fundamental and multiple biologic roles of Dicer in various cellular processes, our results suggest that modulation of Dicer in melanoma should become a promising therapeutic candidate for further clinical application. Note: This abstract was not presented at the conference. Citation Format: Nathalia Cruz de Victo, Sandy Adjemian, Romulo dos Santos Sobreira Nunes, Rildo Aparecido Volpini, Mara Huffenbaecher Giavina-Bianchi, Cyro Festa Neto, Niels Olsen Saraiva Câmara, Gustavo Pessini Amarante-Mendes, Jacqueline de Fátima Jacysyn. Role of Dicer on human melanoma progression and resistance [abstract]. In: Proceedings of the AACR International Conference held in cooperation with the Latin American Cooperative Oncology Group (LACOG) on Translational Cancer Medicine; May 4-6, 2017; São Paulo, Brazil. Philadelphia (PA): AACR; Clin Cancer Res 2018;24(1_Suppl):Abstract nr B59.

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