Effects of nutritional supplementation with leucine in serum and tumour metabolic profile of Walker 256-tumour bearing rats

Orientador: Maria Cristina Cintra Gomes MarcondesTese (doutorado) - Universidade Estadual de Campinas, Instituto de BiologiaResumo: O câncer é um problema mundial com crescente número de mortes. Um dos principais fatores que leva à morte de pacientes com câncer é a caquexia, que é definida como síndrome metabólica e nutricional caracterizada por perda de peso involuntária, principalmente devido à diminuição do tecido muscular esquelético, diminuindo mobilidade, qualidade de vida e sobrevida. Algumas suplementações dietéticas, dentre elas a dieta rica em leucina, podem reduzir os efeitos do câncer caquexia. Vários estudos têm mostrado o papel do aminoácido de cadeia ramificada, leucina em preservar a massa muscular esquelética em pacientes com câncer caquexia. A leucina ativa o complexo 1 da proteína alvo da rapamicina em mamíferos (mTORC1), importante regulador da síntese proteica no músculo esquelético. Desse modo, a leucina é reconhecida com potente estimulador da síntese proteica muscular, sendo considerada ponto chave no tratamento da caquexia. Apesar de estimular síntese proteica, os efeitos da leucina no crescimento tumoral ainda não foram elucidados. O estudo da metabolômica permite identificar e quantificar metabólitos com alta eficiência e confiabilidade, permitindo assim elucidar alterações metabólicas e atividade celular, principalmente durante o estado patológico, detectando assim a presença ou a fase de evolução de algumas doenças, dentre elas o câncer. Considerando a alta eficiência e confiabilidade da metabolômica e que os efeitos da suplementação nutricional com leucina precisam ser melhor entendidos tanto no seu aspecto sistêmico quanto sobre o tecido tumoral, o presente estudo avaliou os efeitos da dieta rica em leucina sobre o perfil metabolômico do soro e do tecido tumoral de ratas portadoras do tumor de Walker 256. Ratas Wistar foram distribuídas em 4 grupos: Controle (C), portadores de tumor de Walker (W), controle leucina (L) e portadores de tumor de Walker suplementados com dieta rica em leucina (LW). Os grupos W e LW receberam a inoculação subcutânea de 1x106 células tumorais viáveis no primeiro dia experimental. Todos os animais foram monitorados durante 19 dias, sendo pesados e avaliados quanto a evolução da massa tumoral, para posterior coleta de soro e amostras do tecido tumoral. As amostras coletadas foram mantidas em nitrogênio líquido e armazenadas em -80°C até o momento das análises. Não houve diferença do peso do tumor entre os grupos W e LW, porém no tecido tumoral LW houve aumento da expressão de proteínas relacionadas com proliferação celular (Ki-67) e síntese proteica (mTOR). Dentre os 58 metabólitos identificados, 11 apresentaram alteração no grupo W, já no grupo LW observou-se 25 metabólitos alterados, sugerindo impactos metabólicos diferentes entre os grupos portadores de tumor. Os resultados do presente estudo mostraram alterações de vias relacionadas com metabolismo de proteínas no grupo W. As vias alteradas no grupo W foram moduladas nos ratos portadores de tumor submetidos à dieta rica em leucina, grupo LW. Encontramos, aumento na síntese e degradação de corpos cetônicos, sugerindo possível mobilização e direcionamento de corpos cetônicos para o tumor no grupo LW. Concluímos que a suplementação com leucina promove modulação metabólica, favorecendo a mobilização e utilização de fontes energéticas (corpos cetônicos) que são utilizadas pela maioria dos tecidos do hospedeiro, mas não pelo tecido tumoral, devido ao fato das células neoplásicas apresentarem capacidade reduzida na metabolização de corpos cetônicos, explicando o resultado de massa tumoral semelhante entre W e LWAbstract: Cancer is a worldwide problem, and the number of deaths related to this disease continues to rise. One of the major factors that lead to death in cancer is cachexia, which handles 25¿30% of all cancer-related deaths. Cancer cachexia is a complex metabolic and nutritional syndrome characterised by involuntary weight loss, mainly due to muscle tissue wasting, leading to less mobility, impaired quality of life, and survival added to poor prognosis. Dietary supplementation can potentially reduce the effects of cancer cachexia. One of these dietary supplements is leucine, which is a branched-chain amino acid (BCAAs) that also acts as a cell signalling, leading to preserve muscle mass in cancer cachectic patients. Leucine activates the mammalian target of rapamycin complex 1 (mTORC1), which is an important regulator of protein synthesis, increasing the protein synthesis in skeletal muscle. However, mTOR signalling also promotes cell proliferation and motility, which could potentially enhance the metastasis. Thus, it is important to determine whether leucine also activates mTOR in tumour tissue. Metabolomics allows the identification and quantification of several metabolites with high precision; which allows the better understanding of the mechanisms of biological and biochemical processes in complex systems, such as cancer cachexia. We consider the metabolomics a good strategy for the identification of metabolites under the effects of leucine supplementation. Therefore, the aim of this study was to analyse the metabolomic derangements in serum and Walker-256 tumour tissue in rats under the modulatory effect of a leucine-rich diet. For this purpose, female Wistar rats were distributed into four experimental groups: C, control group; W, Walker 256 tumour-bearing group; L, leucine control group; LW, Walker 256 tumour-bearing group. We assessed metabolomic profiles of serum and tumour tissue, tumour proliferation and protein synthesis pathways. Among the 58 serum metabolites identified, 11 were changed in W group and 25 metabolites changed in LW group, suggesting a different impact on metabolic pathways between both tumour-bearing groups. The changes found in this study shows changes in the process related to protein metabolism in the W group and that this altered pathways were modulated in tumor-bearing rats fed with leucine-rich diet. We found increase in the synthesis and degradation of ketone bodies, suggesting possible mobilization and redirection of ketone bodies to the tumor in the LW group. Taking all results, we conclude that nutritional supplementation with leucine causes metabolic modulation which can favor the mobilization and utilization of energy sources by most host tissues, and jeopardizes the tumour tissue since cancer cells has reduce ability to metabolize ketone bodies for their own energy supplyDoutoradoFisiologiaDoutora em Biologia Funcional e Molecular2012/06955-0FAPES

USO DE GEOSSINTÉTICOS EM ESTRADAS NÃO PAVIMENTADAS

As estradas não pavimentadas interligam as vias principais a regiões mais afastadas, facilitando os acessos e o escoamento da produção agrícola, influenciando significativamente na economia dos países. Porém apresentam condições inadequadas de rolamento e aderência, capacidade de carga, conforto e durabilidade. Dentre as tecnologias disponíveis para solucionar os problemas associados a performance destas estradas, está o geossintético, utilizado para estabilização do subleito e reforço da base. Este estudo tem como objetivo avaliar em escala real três tipos de geossintéticos, sendo geotêxtil tecido (GTW), geotêxtil não tecido (GTNW) e geogrelha (GG), comparando o comportamento da estrada não pavimentada com e sem estes reforços. O delineamento experimental foi blocos casualizados, em esquema fatorial com testemunha, 3 x 4 + 1, correspondendo aos três tipos de Geossintéticos (GTW, GTNW e GG), quatro profundidades de instalação dos Geossintéticos (1, 2, 3 e 4) e uma testemunha sem G (G0), totalizando 12 tratamentos + 1 testemunha, com 3 blocos para cada tratamento, totalizando 39 unidades experimentais. Os resultados mostraram que estes materiais aumentam a resistência superficial da estrada, principalmente se instalados em menores profundidades, a partir de 0,10m, influenciando na redistribuição de tensões no interior do sistema, reduzindo os recalques e aumentando a capacidade da estrada não pavimentada de suportar os carregamentos que incidem sobre ela. Verificou-se que o deslocamento é mais acentuado quanto menor for a espessura da camada de solo acima do geossintético. Concluiu-se que os geossintéticos estudados, considerando a instalação de 0,10m (instalação mais próxima do rodado) o ganho foi de 20% a 33%. Palavras-chave: estradas vicinais, reforço, trilha de roda, simulador de tráfeg

Convalescent plasma for COVID-19 in hospitalised patients : an open-label, randomised clinical trial

Background: The effects of convalescent plasma (CP) therapy in hospitalised patients with coronavirus disease 2019 (COVID-19) remain uncertain. This study investigates the effect of CP on clinical improvement in these patients. Methods: This is an investigator-initiated, randomised, parallel arm, open-label, superiority clinical trial. Patients were randomly (1:1) assigned to two infusions of CP plus standard of care (SOC) or SOC alone. The primary outcome was the proportion of patients with clinical improvement 28 days after enrolment. Results: A total of 160 (80 in each arm) patients (66.3% critically ill, 33.7% severely ill) completed the trial. The median (interquartile range (IQR)) age was 60.5 (48–68) years; 58.1% were male and the median (IQR) time from symptom onset to randomisation was 10 (8–12) days. Neutralising antibody titres >1:80 were present in 133 (83.1%) patients at baseline. The proportion of patients with clinical improvement on day 28 was 61.3% in the CP+SOC group and 65.0% in the SOC group (difference −3.7%, 95% CI −18.8–11.3%). The results were similar in the severe and critically ill subgroups. There was no significant difference between CP+SOC and SOC groups in pre-specified secondary outcomes, including 28-day mortality, days alive and free of respiratory support and duration of invasive ventilatory support. Inflammatory and other laboratory marker values on days 3, 7 and 14 were similar between groups. Conclusions: CP+SOC did not result in a higher proportion of clinical improvement on day 28 in hospitalised patients with COVID-19 compared to SOC alone

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

Anais do V Encontro Brasileiro de Educomunicação: Educação midiática e políticas públicas

A presente coletânea, que chega ao público através de um suporte digital, tem como objetivo disponibilizar os papers, bem como os relatos de experiências educomunicativas apresentados durante o V ENCONTRO BRASILEIRO DE EDUCOMUNICAÇÃO, que teve como tema central: “Educação Midiática e Políticas Públicas”. O evento foi realizado em São Paulo, entre 19 e 21 de setembro de 2013, a partir de uma parceria entre o NCE/USP - Núcleo de Comunicação e Educação da USP, a Licenciatura em Educomunicação da ECA/USP, a ABPEducom – Associação Brasileira de Pesquisadores e Profissionais da Educomunicação e a FAPCOM – Faculdade Paulus de Tecnologia e Comunicação, que ofereceu seu campus, na Vila Mariana, para os atos do evento. Os presentes anais disponibilizam o texto de abertura, de autoria do coordenador geral do evento, denominado “Educação midiática e políticas públicas: vertentes históricas da emergência da Educomunicação na América Latina”. Na sequência, apresentam 61 papers sobre aspectos específicos da temática geral, resultantes de pesquisas na área, seguidos de 27 relatos de práticas educomunicativas, em nível nacional

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

1H-NMR Based Serum Metabolomics Identifies Different Profile between Sarcopenia and Cancer Cachexia in Ageing Walker 256 Tumour-Bearing Rats

Sarcopenia among the older population has been growing over the last few years. In addition, the incidence of cancers increases with age and, consequently, the development of cachexia related cancer. Therefore, the elucidation of the metabolic derangements of sarcopenia and cachexia are important to improve the survival and life quality of cancer patients. We performed the 1H-NMR based serum metabolomics in adult (A) and ageing (S) Walker 256 tumour-bearing rats in different stages of tumour evolution, namely intermediated (Wi) and advanced (Wa). Among 52 serum metabolites that were identified, 21 were significantly increased in S and 14 and 19 decreased in the Wi and Wa groups, respectively. The most impacted pathways by this metabolic alteration were related by amino acid biosynthesis and metabolism, with an upregulation in S group and downregulation in Wi and Wa groups. Taken together, our results suggest that the increase in metabolic profile in ageing rats is associated with the higher muscle protein degradation that releases several metabolites, especially amino acids into the serum. On the other hand, we hypothesise that the majority of metabolites released by muscle catabolism are used by tumours to sustain rapid cell proliferation and tumorigenesis