A alimentação é um dos custos mais relevantes da produção de bovinos de corte e melhorar a eficiência na utilização de nutrientes é essencial para a viabilidade da produção, dado o atual cenário de crescente demanda por proteína animal e mercado altamente competitivo. Nesse contexto, a proteômica surge como uma importante ferramenta na busca por alternativas que aumentem a eficiência alimentar (EA) de bovinos de corte. Assim, o objetivo deste trabalho é caracterizar o proteoma hepático de bovinos Nelore classificados quanto à EA. Noventa e oito animais foram avaliados em projeto anterior e seis indivíduos de baixa (BEA) e alta eficiência (AEA) tiveram amostras de fígado coletadas no abate, congeladas em Nitrogênio líquido e armazenadas em freezer à -80 ºC. Após a extração e precipitação das proteínas, as amostras foram processadas por duas abordagens distintas: digeridas com tripsina em solução e analisadas em cromatógrafo líquido de alta eficiência acoplado ao espectrômetro de massas (LC-MS/MS); e previamente separadas em gel para posterior digestão e análise (GeLC-MS/MS). Os dados adquiridos por LC-MS/MS foram analisados com o programa MaxQuant contra os bancos de Bos taurus e Bos indicus do Uniprot para identificação das proteínas, e os resultados analisados com o programa Perseus. Os dados obtidos por GeLC-MS/MS foram analisados com os programas Mascot Distiller e X! Tandem e validados no Scaffold Q+ contra o banco Bos taurus do Uniprot e os resultados analisados com os programas Scaffold Q+ e Perseus. Para abordagem LC-MS/MS, 376 proteínas foram quantificadas e submetidas à análise de abundância diferencial e construção de redes de co-expressão pelo WGCNA, identificando 42 proteínas diferencialmente abundantes (PDAs, p < 0,05) e três módulos significativamente associados à EA. Pela abordagem GeLC-MS/MS foram quantificadas 102 proteínas, das quais cinco foram PDAs (p-valor < 0,05). Três PDAs foram comuns às duas abordagens proteômicas. As proteínas associadas negativamente à EA foram principalmente relacionadas à síntese lipídica, degradação de ácidos graxos, enzimas do sistema do citocromo P450 e processos oxidativos. Por outro lado, as proteínas positivamente relacionadas à EA, foram principalmente envolvidas em processamento e enovelamento de proteínas, além de proteínas atuantes na manutenção da integridade e restauração do citoesqueleto celular. Em ambos os grupos também foram identificadas proteínas que atuam no sistema imunológico e resposta inflamatória. Estes resultados comprovam experimentos anteriores do grupo e demonstram a existência de diferença entre os proteomas do fígado de animais eficientes e ineficientes. / Feeding is one of the most relevant cost of beef cattle production and improving nutrient utilization efficiency is essential for the viability of production, given the current scenario of increasing demand for animal protein and highly competitive market. In this context, proteomics appears as an important tool in the search for alternatives that increase the feed efficiency (FE) of beef cattle. Thus, the aim of this work is to characterize the hepatic proteome of beef cattle selected for divergent FE. Ninety-eight animals were evaluated in a previous project, and six individuals with low feed efficiency (LFE) and six with high feed efficiency (HFE) had liver samples collected at slaughter, frozen in liquid Nitrogen and stored in a freezer at -80 °C. After protein extraction and precipitation, the samples were processed by two different approaches: digested with trypsin in solution and analyzed in a high efficiency liquid chromatograph coupled to the mass spectrometer (LC-MS/MS); and previously separated in gel for further digestion and analysis (GeLC-MS/MS). Data acquired by LC-MS/MS were analyzed with MaxQuant software against the Bos taurus and Bos indicus Uniprot databases for proteins identification and the results analyzed with Perseus software. The data obtained by GeLC-MS/MS were analyzed with the softwares Mascot Distiller and X! Tandem and validated in the Scaffold Q+, against Bos taurus Uniprot database and results analyzed with the softwares Scaffold Q+ and Perseus. For the LC-MS/MS approach, 376 proteins were quantified and submitted to differential abundance analysis and co-expression networks by WGCNA, identifying 42 differentially abundant proteins (DAPs, p < 0.05) and three modules significantly associated with FE. For the GeLC-MS/MS approach, 102 proteins were quantified, of which five were DAPs (p-value < 0.05). Three DAPs were common to both proteomics approaches. Proteins negatively associated with FE were mainly related to lipid synthesis, degradation of fatty acids, cytochrome P450 system enzymes and oxidative processes. On the other hand, proteins positively related to FE were mainly involved in protein processing and folding, maintenance of the integrity and restoration of the cellular cytoskeleton. In both groups were also identified proteins that play a role on the immune system and inflammatory response. These results prove previous experiments of the group and demonstrate the existence of difference between liver proteomes of efficient and inefficient animals.

Esse trabalho foi desenvolvido para avaliar a relação entre diferentes medidas de eficiência utilizadas na bovinocultura de corte e as características de desempenho, carcaça e termografia infravermelho (TIV) em bovinos Nelore confinados. Foram utilizados 111 bovinos Nelore, machos não-castrados contemporâneos, com idade aproximada de 16±2 meses, peso corporal médio de 420±55 kg. Os animais foram confinados por 91 dias, sendo 21 dias de adaptação às instalações e à dieta. A dieta foi a mesma para todos os animais e composta por 73% de concentrado e 27% de volumoso. O consumo de matéria seca (CMS) foi avaliado diariamente, enquanto o peso vivo, medidas de ultrassom para avaliação de características de carcaça e imagens de TIV foram realizadas a cada 28 dias até o dia 70. A partir dos dados de CMS foram calculados o consumo alimentar residual (CAR), ganho de peso residual (GPR), consumo e ganho residual (CGR). Após a obtenção dos dados foram realizadas análises de associação (correlação e regressão) visando à identificação de possíveis relações entre as diferentes características com as medidas de eficiência. Não houve correlação entre o GMD com o CAR (r=0,001), e com o CGR (r= 0,114), enquanto o GPR apresentou correlação com o GMD (r= 0,588). O CMS foi correlacionado com o CAR (r= 0,612) e com o CGR (r= -0,532) e não houve correlação com o GPR (r= -0,002). Não houve correlação entre as medidas de eficiência com as características de peso vivo inicial (PVI) e peso vivo final (PV70). Dentre as características de carcaça avaliadas ao abate, apenas o GPR apresentou correlação com a gordura renal pélvica e inguinal (GRPIkg), trato gastrintestinal (TGIkg) e peso de corpo vazio (PCVZkg) na ordem de (r= 0,240), (r= 0,226) e (r= 0,210), respectivamente. Entre as medidas de carcaça avaliadas por ultrassom, apenas a espessura de gordura subcutânea (EGS) final apresentou correlação com o CAR (r= 0,348), GPR (r= -0,188) e CGR (r= -0,340), enquanto a espessura de gordura da picanha (EGP) final apresentou correlação apenas com o CAR (r= 0,233) e CGR (r= -0,200). Houveram correlações entre o ganho de EGS e o CAR (r= 0,371) e CGR (r= 0,345), porém o ganho de EGP se correlacionou apenas com o CAR (r= 0,202). Não foram observadas correlações entre as medidas de eficiência e TIV, porém, esses resultados podem ter sido influenciados pelos fatores ambientais. A AOL não apresentou correlação com nenhuma das medidas de eficiência avaliadas. Dessa forma conclui-se que, o CAR é a medida que mais se aplica n seleção de animais de menor CMS, sem prejuízos as características de desempenho. Adicionalmente, o CAR e CGR selecionam animais mais eficientes em termos de menor consumo, enquanto que o GPR seleciona animais de maior GMD. / The aim of the present study was to evaluate the relationship between different efficiency indexes used in beef cattle and performance, carcass traits and thermography in Nellore cattle at the feedlot system. A total of 111 Nellore male, with around 16±2 months age and 420±55 kg of body weight, were used. The animals were confined for 91 days, with 21 days for adaptation to the facilities and diet. The diet was the same for all animals, and composed by 73% of concentrate and 27% of roughage. Dry matter intake (DMI) was evaluated daily, and performance, ultrasound measurements and infrared thermography images were performed every 28 days until day 70. From the DMI measurements, residual feed intake (RFI), residual weight gain (RWG), residual intake and body weight gain (RIG) were calculated. From the data obtained, association analysis (correlation and regression) were performed to identify the possibilities relationships between the different characteristics with the efficiency measures. The ADG showed no correlation with RFI (r= 0.001) and RIG (r= 0.114); however, the RWG was correlated with ADG (r= 0.588). DMI was correlated with RFI (r= 0.612) and RIG (r= -0.532) and there was no correlation with RWG (r= -0.002) There was no correlation between efficiency measures with initial body weight (IBW) and final body weight (BW70). For carcass traits, evaluated at slaughter, only the RWG showed correlation with pelvic renal and inguinal fat (PRIFkg), gastrintestinal tract (GITkg) and empty body weight (EBWkg) in order of the (r= 0.240), (r= 0.226) and (r= 0.210), respectively. For carcass measurements evaluated by ultrasound, the final backfat thickness (BFT) showed correlation with RFI (r= 0.348), RWG (r= -0.188) and RIG (r= -0.340), while final subcutaneous fat thickness on the Biceps femoris muscle (BFTP8) showed a correlation with RFI (r= 0.233) and RIG (r= -0.220). In addition, BFT gain has been also correlated with RFI (r= 0.371) and RIG (r= 0.345); however, the BFTP8 gain only showed correlation with the RFI (r=0.202). There was no correlation between efficiency measures and the infrared thermography (IRT). The rib eye area (REA) showed no correlation with any the efficiency measures evaluated. In conclusion, the RFI is the measure that most applies in the selection of animals of smaller DMI, without damage to the performance traits. In addition, the RFI and RIG can promoter the selection of more efficient animals by lower consumer, whereas the RWG selected great ADG animals.

Uma nutrição maternal rica em lipídios pode causar prejuízos no desenvolvimento e na vida adulta dos descendentes, como elevado risco de desenvolver alterações metabólicas e obesidade, e também parece alterar a sinalização central por opióides. Porém, estudos realizados a fim de investigar a influência da dieta hiperlipídica (HF) materna sobre o comportamento materno e o desenvolvimento da prole não são conclusivos. Este trabalho investigou a influência da dieta HF sobre a interação mãe-filhote, em duas gerações, e os efeitos imediatos e tardios sobre a prole, relacionando-os ao sistema opióide. As mães HF apresentaram prejuízos na ejeção do leite e maior expressão dos receptores opióides no hipotálamo. No geral, os descendentes HF apresentaram elevados níveis de colesterol, baixa leptina plasmática, maior expressão de peptídeos relacionados à ingestão alimentar, e menor peso. Portanto, o consumo materno de dieta HF causou alterações metabólicas, comportamentais e na expressão gênica na mãe e nos descendentes, mesmo que esses animais não tenham se tornado obesos. / A maternal nutrition high in fat may impair offspring development and adulthood, increasing the risk to develop metabolic alterations and obesity, and may modify the opioids central signaling. However, studies investigating maternal high fat (HF) diet influences on maternal behavior and offspring development are inconclusive. This study aimed to evaluate the influences of a diet high in fat on mother-pup interaction, in two generations, and its early and late effects in the offspring, connecting them to the opioid system. HF dams show decreased milk ejections and higher expression of opioid receptors in the hypothalamus. Overall, HF offspring had higher cholesterol levels, less serum leptin, higher expression of peptides related to food intake, and were lighter. Therefore, maternal intake of HF diet promoted metabolic, behavioral and gene expression alterations in the mother and her offspring, even though these animals did not become obese.

abstract: Urinary sucrose and fructose has been suggested as a predictive biomarker of total sugars intake based on research involving UK adults. The purpose of this study was to determine the association between total sugars consumption and 24-hour urinary sucrose and fructose (24uSF) in US adult population and to investigate the effect of physical activity on this association. Fifty seven free-living healthy subjects 20 to 68 years old, participated in a 15-day highly controlled feeding study, consuming their habitual diet, provided by the research metabolic kitchen. Dietary sugars were estimated using Nutrition Data System for Research (NDSR). Subjects collected eight 24-hour urine samples measured for urinary sucrose and fructose. Physical activity was assessed daily using a validated 15-day log that inquired about 38 physical activities across six domains; home activities, transportation, occupation, conditioning, sports and leisure. The mean total sugars intake and added sugars intake of the sample was 112.2 (33.1) g/day and 65.8 (29.0) g/day (9.7%EI), respectively. Significant moderate positive correlation was found between 15-d mean total sugars intake and 8-day mean 24uSF (r = 0.56, p < 0.001). Similarly, added sugars were moderately correlated with 24uSF (r = 0.56, p < 0.001), while no correlation was found between naturally-occurring sugars and 24uSF (r = 0.070, p < 0.001). In a linear multiple regression, total and added sugars each explained 30% of variability in 24uSF (Adjusted R2, p value; total sugars: 0.297, 0.001; added sugars: 0.301, p < 0.001). Physical activity had no effect on the association between dietary and urinary sugars in neither the correlation nor the linear regression analysis. 24uSF can be used as a biomarker for total and added sugars consumption in US adults, although its predictability was weaker compared to findings involving UK adults. No evidence was found showing that physical activity levels affect the association between 24uSF and total sugars intake in US adults. More detailed investigation through future feeding studies including subjects with wide range of sugars intake and of different ethnic/racial backgrounds are needed to better understand the characteristics of the biomarker and its uses. / Dissertation/Thesis / Masters Thesis Nutrition 2019

Glycemic intake influences the rise in blood glucose concentration following consumption of a carbohydrate containing meal, known as the postprandial glycemic response. The glycemic response is a result of both the type and amount of carbohydrate foods consumed and is commonly measured as the glycemic index (GI) or glycemic load (GL), where the GI is a ranking in comparison to glucose and the GL is an absolute value encompassing both the GI and amount of carbohydrate consumed. Evidence from controlled trials in rat models suggests that glycemic intake has a role in development of insulin resistance, however trials and observational studies of humans have produced conflicting results. As insulin resistance is a precursor to type 2 diabetes mellitus, lifestyle factors that could prevent development of this condition have important public health implications. Previous observational studies have used food frequency questionnaires to assess usual diet, which could have resulted in a lack of precision in assessment of individual serve sizes, and have been limited to daily measures of glycemic intake. Daily measures do not take fluctuations in glycemic intake on a per meal basis into account, which may be a more relevant measure for investigation in relation to disease outcomes. This PhD research was conducted in a group of Brisbane women aged 42 to 81 years participating in the multidisciplinary Brisbane Longitudinal Assessment of Ageing in Women (LAW study). Older women may be at particular risk of insulin resistance due to age, hormonal changes, and increases in abdominal obesity associated with menopause, and the LAW study provided an ideal opportunity to study the relationship between diet and insulin resistance. Using the diet history tool, we aimed to assess the glycemic intake of the population and hypothesised that daily GI and daily GL would be significantly positively associated with increased odds of insulin resistant status. We also hypothesised that a new glycemic measure representing peaks in GL at different meals would be a stronger predictor of insulin resistant status than daily measures, and that a specially designed questionnaire would be an accurate and repeatable dietary tool for assessment of glycemic intake. To address these hypotheses, we conducted a series of studies. To assess glycemic intake, information on usual diet was obtained by detailed diet history interview and analysed using Foodworks and the Australian Food and Nutrient (AUSNUT) database, combined with a customised GI database. Mean ± SD intakes were 55.6 ± 4.4% for daily GI and 115 ± 25 for daily GL (n=470), with intake higher amoung younger participants. Bread was the largest contributor to intakes of daily GI and GL (17.1% and 20.8%, respectively), followed by fruit (15.5% and 14.2%, respectively). To determine whether daily GI and GL were significantly associated with insulin resistance, the homeostasis model assessment of insulin resistance (HOMA) was used to assess insulin resistant status. Daily GL was significantly higher in subjects who were insulin resistant compared to those who were not (134 ± 33 versus 114 ± 24 respectively, P<0.001) (n=329); the odds of subjects in the highest tertile of GL intake being insulin resistant were 12.7 times higher when compared with the lowest tertile of GL (95% CI 1.6-100.1, P=0.02). Daily GI was not significantly different in subjects who were insulin resistant compared to those who were not (56.0 ± 3.3% versus 55.7 ± 4.5%, P=0.69). To evaluate whether a new glycemic measure representing fluctuations in daily glycemic intake would be a stronger predictor of insulin resistant status than other glycemic intake measures, the GL peak score was developed to express in a single value the magnitude of GL peaks during an average day. Although a significant relationship was seen between insulin resistant status and GL peak score (Nagelkerke’s R2=0.568, P=0.039), other glycemic intake measures of daily GL (R2=0.671, P<0.001) and daily GL per megajoule (R2=0.674, P<0.001) were stronger predictors of insulin resistant status. To develop an accurate and repeatable self-administered tool for assessment of glycemic intake, two sub-samples of women (n=44 for the validation study and n=52 for the reproducibility study) completed a semi-quantitative questionnaire that contained 23 food groupings selected to include the top 100 carbohydrate foods consumed by the study population. While there were significant correlations between the glycemic intake questionnaire and the diet history for GL (r=0.54, P<0.01), carbohydrate (r=0.57, P<0.01) and GI (r=0.40, P<0.01), Bland-Altman plots showed an unacceptable difference between individual intakes in 34% of subjects for daily GL and carbohydrate, and 41% for daily GI. Reproducibility results showed significant correlations for daily GL (r=0.73, P<0.001), carbohydrate (r=0.76, P<0.001) and daily GI (r=0.64, P<0.001), but an unacceptable difference between individual intakes in 25% of subjects for daily GL and carbohydrate, and 27% for daily GI. In summary, our findings show that a significant association was observed between daily glycemic load and insulin resistant status in a group of older women, using a diet history interview to obtain precise estimation of individual carbohydrate intake. Both the type and quantity of carbohydrate are important to consider when investigating relationships between diet and insulin resistance, although our results suggest the association is more closely related to overall daily glycemic intake than individual meal intake variations. A dietary tool that permits precise estimation of carbohydrate intake is essential when evaluating possible associations between glycemic intake and individual risk of chronic diseases such as insulin resistance. Our results also suggest that studies using questionnaires to estimate glycemic intake should state degree of agreement as well as correlation coefficients when evaluating validity, as imprecise estimates of carbohydrate at an individual level may have contributed to the conflicting findings reported in previous studies.

As dificuldades associadas à coleta de urina de 24h e à baixa credibilidade do uso do biomarcador na prática clínica para estimar a ingestão de proteína de pacientes com doença renal crônica (DRC) na fase não-dialítica sinalizam para busca de alternativas acuradas e de ampla acessibilidade para a descrição do consumo de proteína nessa população. Avaliar a acurácia de métodos de inquérito dietético para estimar o consumo de proteína em pacientes de DRC na fase não dialítica e, a concordância desses com o biomarcador de ingestão protéica. Também foi avaliado a concordâncias entre o registro alimentar (RA) e recordatório alimentar de 24 horas (Rec24h). Cento e vinte e dois pacientes com DRC na fase não dialítica, que atenderam aos critérios de elegibilidade, foram submetidos à avaliação antropométrica, laboratorial e, tiveram a ingestão de proteína estimada por três métodos de avaliação do consumo alimentar, sendo estes dois métodos de inquérito dietético e um método de biomarcador. Os métodos de inquéritos alimentares compreenderam 4 dias de RA e 2 dias de Rec24h. Para o biomarcador foi avaliado a excreção de nitrogênio uréico em uma amostra de urina de 24 horas, o qual foi utilizado em equação do equivalente protéico do aparecimento do de nitrogênio uréico (PNA). Na análise estatística dos métodos de inquérito dietético, utilizou-se o PC-Side para estimar a variabilidade da ingestão de proteína, equações para estimar o número de dias necessários para estimativas acuradas da ingestão de proteína em avaliações no nível individual e coletivo. Para avaliar a concordância entre os três métodos de avaliação do consumo de proteína, utilizou-se o Concordance correlation coefficient (CCC) e o gráfico de Bland & Altman. Resultados: Os 4 dias de RA e 2 Rec24h descreveram com acurácia elevada a ingestão de proteína no nível coletivo, sendo respectivamente de 0,85 e 0,73. Para o nível individual, com erro tolerado intermediário de 20% (acurácia de 0,8), foram necessários 6 dias de RA e 5 de Rec24h para avaliação do consumo de proteína. Ao avaliar a concordância entre o PNA com o RA e Rec24h, observou-se CCC reduzido (< 0,3). Da mesma forma, ao avaliar a dispersão individual das diferenças obtidas entre o PNA e RA e Rec24h pelo gráfico de Bland & Altman, notou-se valores amplos de limite de concordância. Por outro lado, valores mais elevados de CCC (>0,4) foram encontrados entre o RA e o Rec24h. O gráfico de Bland & Altman desses dois métodos mostrou menor dispersão. Contudo, essa melhor concordância pode ser decorrente de superestimação da correspondência entre os métodos. Além disso, a concordância reduzida observada entre o PNA e o RA e Rec24h não permitiram afirmar que os métodos de inquéritos dietéticos ofereçam medidas irreais da ingestão de proteína, nem tampouco foi possível afirmar que a medida real é aquela sugerida pelo PNA. Em pacientes com DRC na fase não dialítica, orientada a seguir dieta hipoprotéica, o RA e Rec24h podem ser usados em substituição ao uso PNA como alternativas de baixo custo e de ampla acessibilidade à prática clínica para descrever a ingestão de proteína, desde que sejam definidos o nível da avaliação, o número ideal de dias e a acurácia desejada. / It has been well described in the literature the errors inherent to the 24 hours urine collection in free-living individuals. Therefore, the assessment of protein intake in nondialyzed chronic kidney disease (CKD) patients by the urinary urea excretion in the 24 hour urine sample, may lead to important errors related to the method itself. In this regard, assessing surrogate methods is of high relevance. To evaluate the accuracy of the dietary methods to estimate the protein consumption in nondialyzed CKD patients and also to assess the agreement between a biomarker of protein intake and dietary methods. In addition, it was also evaluated the agreement between two dietary methods. One hundred and twenty-two nondialyzed CKD patients, who met the eligibility criteria, were included. All participants underwent to antropometric and laboratory assessments, and had the protein intake estimated by three methods: two methods of dietary intake and one dietary biomarker. The dietary intake comprised 4 days of food records (FRec) and 2 days of 24-hour food recall (24hFRecall). For the biomarker, it was evaluated the urinary urea nitrogen excretion in a 24 hours urine sample, which was used in the equation of the protein equivalent of nitrogen appearance (PNA). The software PC-Side was used to estimate the variability of the protein intake in the FRec and 24hFRecall. In addition, specific equations were used to assess the number of days needed to estimate the protein intake with high accuracy in the individual and collective level. In order to evaluate the agreement between the 3 methods, it was used the concordance correlation coefficient (CCC) and the Bland & Altman plot analysis (1986). In the collective level, 4 days FRec and the 2 days of 24hFRecall described the protein intake with an accuracy close the highest acceptable level, being of respectively 0.85 and 0.73. For the individual level, by accepting an intermediate tolerated error of 20% (accuracy 0.8), 6 days of FR and 5 days of 24hFR were needed for the assessment of protein intake. When assessing the agreement between the PNA and the FRec and 24hFRecall, it was observed reduced CCC (< 0.3). Likewise, when evaluating the individual differences obtained between the PNA and the FRec and 24hFRecall by the Bland & Altman plot analysis, it was observed a wide concordance limit, which is consistent with the low concordance observed between the methods. Moreover, higher values of CCC (> 0.4) were found between the FRec and 24hFRecall. The Bland & Altman plot analysis of these two methods showed more narrows differences, which is consistent with the higher CCC observed. However, this best agreement may be due to an overestimation between the methods. Furthermore, the reduced concordance observed between the PNA and the FRec and 24hFRecall does not mean that the dietary intake methods give biased or unrepresentative measurements of protein intake, nor was that the PNA gave unbiased measurements of protein intake. FRec and 24hFRecall can be used as surrogate methods for the PNA, as an alternative low cost and high applicability method in the clinical routine practice to describe the protein intake.

As dificuldades associadas à coleta de urina de 24h e à baixa credibilidade do uso do biomarcador na prática clínica para estimar a ingestão de proteína de pacientes com doença renal crônica (DRC) na fase não-dialítica sinalizam para busca de alternativas acuradas e de ampla acessibilidade para a descrição do consumo de proteína nessa população. Avaliar a acurácia de métodos de inquérito dietético para estimar o consumo de proteína em pacientes de DRC na fase não dialítica e, a concordância desses com o biomarcador de ingestão protéica. Também foi avaliado a concordâncias entre o registro alimentar (RA) e recordatório alimentar de 24 horas (Rec24h). Cento e vinte e dois pacientes com DRC na fase não dialítica, que atenderam aos critérios de elegibilidade, foram submetidos à avaliação antropométrica, laboratorial e, tiveram a ingestão de proteína estimada por três métodos de avaliação do consumo alimentar, sendo estes dois métodos de inquérito dietético e um método de biomarcador. Os métodos de inquéritos alimentares compreenderam 4 dias de RA e 2 dias de Rec24h. Para o biomarcador foi avaliado a excreção de nitrogênio uréico em uma amostra de urina de 24 horas, o qual foi utilizado em equação do equivalente protéico do aparecimento do de nitrogênio uréico (PNA). Na análise estatística dos métodos de inquérito dietético, utilizou-se o PC-Side para estimar a variabilidade da ingestão de proteína, equações para estimar o número de dias necessários para estimativas acuradas da ingestão de proteína em avaliações no nível individual e coletivo. Para avaliar a concordância entre os três métodos de avaliação do consumo de proteína, utilizou-se o Concordance correlation coefficient (CCC) e o gráfico de Bland & Altman. Resultados: Os 4 dias de RA e 2 Rec24h descreveram com acurácia elevada a ingestão de proteína no nível coletivo, sendo respectivamente de 0,85 e 0,73. Para o nível individual, com erro tolerado intermediário de 20% (acurácia de 0,8), foram necessários 6 dias de RA e 5 de Rec24h para avaliação do consumo de proteína. Ao avaliar a concordância entre o PNA com o RA e Rec24h, observou-se CCC reduzido (< 0,3). Da mesma forma, ao avaliar a dispersão individual das diferenças obtidas entre o PNA e RA e Rec24h pelo gráfico de Bland & Altman, notou-se valores amplos de limite de concordância. Por outro lado, valores mais elevados de CCC (>0,4) foram encontrados entre o RA e o Rec24h. O gráfico de Bland & Altman desses dois métodos mostrou menor dispersão. Contudo, essa melhor concordância pode ser decorrente de superestimação da correspondência entre os métodos. Além disso, a concordância reduzida observada entre o PNA e o RA e Rec24h não permitiram afirmar que os métodos de inquéritos dietéticos ofereçam medidas irreais da ingestão de proteína, nem tampouco foi possível afirmar que a medida real é aquela sugerida pelo PNA. Em pacientes com DRC na fase não dialítica, orientada a seguir dieta hipoprotéica, o RA e Rec24h podem ser usados em substituição ao uso PNA como alternativas de baixo custo e de ampla acessibilidade à prática clínica para descrever a ingestão de proteína, desde que sejam definidos o nível da avaliação, o número ideal de dias e a acurácia desejada. / It has been well described in the literature the errors inherent to the 24 hours urine collection in free-living individuals. Therefore, the assessment of protein intake in nondialyzed chronic kidney disease (CKD) patients by the urinary urea excretion in the 24 hour urine sample, may lead to important errors related to the method itself. In this regard, assessing surrogate methods is of high relevance. To evaluate the accuracy of the dietary methods to estimate the protein consumption in nondialyzed CKD patients and also to assess the agreement between a biomarker of protein intake and dietary methods. In addition, it was also evaluated the agreement between two dietary methods. One hundred and twenty-two nondialyzed CKD patients, who met the eligibility criteria, were included. All participants underwent to antropometric and laboratory assessments, and had the protein intake estimated by three methods: two methods of dietary intake and one dietary biomarker. The dietary intake comprised 4 days of food records (FRec) and 2 days of 24-hour food recall (24hFRecall). For the biomarker, it was evaluated the urinary urea nitrogen excretion in a 24 hours urine sample, which was used in the equation of the protein equivalent of nitrogen appearance (PNA). The software PC-Side was used to estimate the variability of the protein intake in the FRec and 24hFRecall. In addition, specific equations were used to assess the number of days needed to estimate the protein intake with high accuracy in the individual and collective level. In order to evaluate the agreement between the 3 methods, it was used the concordance correlation coefficient (CCC) and the Bland & Altman plot analysis (1986). In the collective level, 4 days FRec and the 2 days of 24hFRecall described the protein intake with an accuracy close the highest acceptable level, being of respectively 0.85 and 0.73. For the individual level, by accepting an intermediate tolerated error of 20% (accuracy 0.8), 6 days of FR and 5 days of 24hFR were needed for the assessment of protein intake. When assessing the agreement between the PNA and the FRec and 24hFRecall, it was observed reduced CCC (< 0.3). Likewise, when evaluating the individual differences obtained between the PNA and the FRec and 24hFRecall by the Bland & Altman plot analysis, it was observed a wide concordance limit, which is consistent with the low concordance observed between the methods. Moreover, higher values of CCC (> 0.4) were found between the FRec and 24hFRecall. The Bland & Altman plot analysis of these two methods showed more narrows differences, which is consistent with the higher CCC observed. However, this best agreement may be due to an overestimation between the methods. Furthermore, the reduced concordance observed between the PNA and the FRec and 24hFRecall does not mean that the dietary intake methods give biased or unrepresentative measurements of protein intake, nor was that the PNA gave unbiased measurements of protein intake. FRec and 24hFRecall can be used as surrogate methods for the PNA, as an alternative low cost and high applicability method in the clinical routine practice to describe the protein intake.

Uma nutrição maternal rica em lipídios pode causar prejuízos no desenvolvimento e na vida adulta dos descendentes, como elevado risco de desenvolver alterações metabólicas e obesidade, e também parece alterar a sinalização central por opióides. Porém, estudos realizados a fim de investigar a influência da dieta hiperlipídica (HF) materna sobre o comportamento materno e o desenvolvimento da prole não são conclusivos. Este trabalho investigou a influência da dieta HF sobre a interação mãe-filhote, em duas gerações, e os efeitos imediatos e tardios sobre a prole, relacionando-os ao sistema opióide. As mães HF apresentaram prejuízos na ejeção do leite e maior expressão dos receptores opióides no hipotálamo. No geral, os descendentes HF apresentaram elevados níveis de colesterol, baixa leptina plasmática, maior expressão de peptídeos relacionados à ingestão alimentar, e menor peso. Portanto, o consumo materno de dieta HF causou alterações metabólicas, comportamentais e na expressão gênica na mãe e nos descendentes, mesmo que esses animais não tenham se tornado obesos. / A maternal nutrition high in fat may impair offspring development and adulthood, increasing the risk to develop metabolic alterations and obesity, and may modify the opioids central signaling. However, studies investigating maternal high fat (HF) diet influences on maternal behavior and offspring development are inconclusive. This study aimed to evaluate the influences of a diet high in fat on mother-pup interaction, in two generations, and its early and late effects in the offspring, connecting them to the opioid system. HF dams show decreased milk ejections and higher expression of opioid receptors in the hypothalamus. Overall, HF offspring had higher cholesterol levels, less serum leptin, higher expression of peptides related to food intake, and were lighter. Therefore, maternal intake of HF diet promoted metabolic, behavioral and gene expression alterations in the mother and her offspring, even though these animals did not become obese.

A seleção de bovinos de corte para eficiência alimentar (EA) é bastante vantajosa não só do ponto de vista produtivo e econômico como também por ajudar a diminuir o impacto ambiental da produção pecuária. Por ser uma característica multifatorial e de mensuração onerosa, objetivou-se com esse trabalho, a partir da expressão gênica global hepática de animais com alta eficiência alimentar (AEA) e baixa eficiência alimentar (BEA), identificar novos genes, funções biológicas e genes reguladores associados a esse fenótipo. Para isso, 98 bovinos Nelore foram avaliados quanto ao desempenho em confinamento, medidas de EA, ultrassonografia de carcaça, bioquímica sérica, biometria, rendimento de carcaça, maciez de carne e avaliação de líquido ruminal. Além disso, 8 animais de AEA e 8 animais de BEA, selecionados pela medida de consumo e ganho residual ao final do confinamento, tiveram dados de perfil transcriptômico hepático analisados por 3 abordagens: expressão gênica diferencial, co-expressão e co-expressão diferencial. Foi observado que os grupos de AEA e BEA apresentaram desempenho igual quanto ao peso inicial e final, ganho de peso, rendimento de carcaça e área de olho de lombo. Por outro lado, os animais de BEA tiveram maior consumo de alimentos e maior deposição de gordura subcutânea e visceral. Além disso, os animais de BEA apresentaram níveis elevados de colesterol e de GGT e a análise de perfil transcriptômico mostrou estar relacionada à resposta imunológica, inflamação e metabolismo de lipídeos. Baseado nesses resultados e em pesquisas em humanos criou-se a hipótese de que os animais de BEA são mais susceptíveis a infecção bacteriana no fígado em resposta à mudança da dieta a pasto para a dieta de confinamento. / The selection of beef cattle to feed efficiency (FE) traits is very important not only from the productive and economic perspective but also for helping to reduce the environmental impact of livestock production. Being a multifactorial and expensive to measurement trait, the aim of this work was to analyze the liver global gene expression profile of animals with high feed efficiency (HFE) and low feed efficiency (LFE), to identify new genes, biological functions and regulatory genes associated to this phenotype. For this purpose, 98 Nellore cattle were evaluated regarding feedlot performance, FE measures, carcass ultrasound, serum biochemistry, biometric measures, carcass evaluation, meat tenderness and evaluation of ruminal fluid. In addition, 8 animals of HFE and 8 animals of LFE, selected by the measure of residual intake and body weight gain at the end of feeding trial, had liver transcriptomic profile data analyzed by three approaches: differential gene expression, co-expression and differential co-expression. It was observed that HFE and LFE groups showed equal performance for initial and final weight, weight gain, carcass yield and rib eye area. On the other hand, the animals of LFE had higher feed intake and increased deposition of subcutaneous and visceral fat. In addition, animals of LFE showed higher levels of cholesterol and GGT and transcriptomic profile analysis showed to be related to immune response, inflammation and lipid metabolism. Based on these results and research in humans we created the hypothesis that the LFE animals are more susceptible to bacterial infection in the liver in response to the change of pasture diet to feedlot diet.

Background: People in Cameroon are experiencing a dietary transition characterized by changing from traditional food habits to increased intake of highly processed sweet and fatty food. The rapid change in food pattern combined with an increased sedentary lifestyle has resulted in a rather high prevalence of obesity, hypertension, cardiovascular diseases and type 2 diabetes. Nutritional intake is important during adolescence for growth spurt, health, cognitive development and performance in school. Objective: The aim of this thesis was to assess dietary intake, anthropometry and physical activity of adolescents according to sex and socioeconomic status (SES) and to investigate food perceptions of adolescents living in urban and rural areas of Cameroon. Methods: Girls and boys, 12-16 years of age, were randomly selected from schools in urban and rural areas. Food frequency questionnaire, 24-hour dietary and physical activity recalls, anthropometric measurements, qualitative interviews and a background questionnaire were used for data collection. Results: The proportion of overweight was three times higher in girls (14%) compared to boys (4%). Stunting and underweight were more common among boys (15% and 6%) than girls (5% and 1%). The prevalence of stunting was two times higher among the urban adolescents with low SES (12%) compared to those with high SES (5%). The rural adolescents had the highest proportion of stunting but more muscle that the urban adolescents. The rural adolescents ate in order to live and to maintain health. Urban adolescents with low SES ate in order to maintain health, while those with high SES ate for pleasure. More than 30% of the adolescents skipped breakfast in the urban area. Urban adolescents with high SES and girls reported a more frequent consumption of in-between meals and most food groups compared to the rural adolescents, boys and those with low SES. Over 55% of the adolescents had a protein intake below 10% of the energy (E%). Twenty-six percent of the adolescents had fat intake below 25 E%, and 25% had fat intake above 35 E%. A large proportion of the adolescents had an intake of micronutrients below the estimated average recommendation. Boys and the adolescents with low SES reported a higher energy expenditure and physical activity level than girls and the adolescents with high SES, respectively. Both under- and over-reporting of energy intake were common among the adolescents. Conclusions: The present study showed that nutrient inadequacy, stunting, underweight, as well as overweight and obesity were common among the adolescents in Cameroon. Therefore an intervention program targeting both under- and overnutrition among school adolescents is needed. Sex and socioeconomic differences also need to be considered.