Evidence-Based Tools for Dietary Assessments in Nutrition Epidemiology Studies for Dementia Prevention.

Increasing evidence proposes diet as a notable modifiable factor and viable target for the reduction of Alzheimer's Disease risk and age-related cognitive decline. However, assessment of dietary exposures is challenged by dietary capture methods that are prone to misreporting and measurement errors. The utility of -omics technologies for the evaluation of dietary exposures has the potential to improve reliability and offer new insights to pre-disease indicators and preventive targets in cognitive aging and dementia. In this review, we present a focused overview of metabolomics as a validation tool and framework for investigating the immediate or cumulative effects of diet on cognitive health.

Investigating the Role of Diet and Exercise in Gut Microbe-Host Cometabolism.

We investigated the individual and combined effects of diet and physical exercise on metabolism and the gut microbiome to establish how these lifestyle factors influence host-microbiome cometabolism. Urinary and fecal samples were collected from athletes and less active controls. Individuals were further classified according to an objective dietary assessment score of adherence to healthy dietary habits according to WHO guidelines, calculated from their proton nuclear magnetic resonance (1H-NMR) urinary profiles. Subsequent models were generated comparing extremes of dietary habits, exercise, and the combined effect of both. Differences in metabolic phenotypes and gut microbiome profiles between the two groups were assessed. Each of the models pertaining to diet healthiness, physical exercise, or a combination of both displayed a metabolic and functional microbial signature, with a significant proportion of the metabolites identified as discriminating between the various pairwise comparisons resulting from gut microbe-host cometabolism. Microbial diversity was associated with a combination of high adherence to healthy dietary habits and exercise and was correlated with a distinct array of microbially derived metabolites, including markers of proteolytic activity. Improved control of dietary confounders, through the use of an objective dietary assessment score, has uncovered further insights into the complex, multifactorial relationship between diet, exercise, the gut microbiome, and metabolism. Furthermore, the observation of higher proteolytic activity associated with higher microbial diversity indicates that increased microbial diversity may confer deleterious as well as beneficial effects on the host.IMPORTANCE Improved control of dietary confounders, through the use of an objective dietary assessment score, has uncovered further insights into the complex, multifactorial relationship between diet, exercise, the gut microbiome, and metabolism. Each of the models pertaining to diet healthiness, physical exercise, or a combination of both, displayed a distinct metabolic and functional microbial signature. A significant proportion of the metabolites identified as discriminating between the various pairwise comparisons result from gut microbe-host cometabolism, and the identified interactions have expanded current knowledge in this area. Furthermore, although increased microbial diversity has previously been linked with health, our observation of higher microbial diversity being associated with increased proteolytic activity indicates that it may confer deleterious as well as beneficial effects on the host.

Addressing the pitfalls when designing intervention studies to discover and validate biomarkers of habitual dietary intake.

INTRODUCTION: Dietary exposure monitoring within populations is reliant on self-reported measures such as Food Frequency Questionnaires and diet diaries. These methods often contain inaccurate information due to participant misreporting, non-compliance and bias. Urinary metabolites derived from individual foods could provide additional objective indicators of dietary exposure. For biomarker approaches to have utility it is essential that they cover a wide-range of commonly consumed foods and the methodology works in a real-world environment. OBJECTIVES: To test that the methodology works in a real-world environment and to consider the impact of the major sources of likely variance; particularly complex meals, different food formulations, processing and cooking methods, as well as the dynamics of biomarker duration in the body. METHODS: We designed and tested a dietary exposure biomarker discovery and validation strategy based on a food intervention study involving free-living individuals preparing meals and collecting urine samples at home. Two experimental periods were built around three consecutive day menu plans where all foods and drinks were provided (n = 15 and n = 36). RESULTS: The experimental design was validated by confirming known consumption biomarkers in urinary samples after the first menu plan. We tested biomarker performance with different food formulations and processing methods involving meat, wholegrain, fruits and vegetables. CONCLUSION: It was demonstrated that spot urine samples, together with robust dietary biomarkers, despite major sources of variance, could be used successfully for dietary exposure monitoring in large epidemiological studies.

Application of 1H NMR spectroscopy to the metabolic phenotyping of rodent brain extracts: A metabonomic study of gut microbial influence on host brain metabolism.

1H NMR Spectroscopy has been applied to determine the neurochemical profiles of brain extracts from the frontal cortex and hippocampal regions of germ free and normal mice and rats. The results revealed a number of differences between germ free (GF) and conventional (CV) rats or specific pathogen-free (SPF) mice with microbiome-associated metabolic variation found to be both species- and region-dependent. In the mouse, the GF frontal cortex contained lower amounts of creatine, N-acetyl-aspartate (NAA), glycerophosphocholine and lactate, but greater amounts of choline compared to that of specific pathogen free (SPF) mice. In the hippocampus, the GF mice had greater creatine, NAA, lactate and taurine content compared to those of the SPF animals, but lower relative quantities of succinate and an unidentified lipid-related component. The GF rat frontal cortex contained higher relative quantities of lactate, creatine and NAA compared to the CV animals whilst the GF hippocampus was characterized by higher taurine and phosphocholine concentrations and lower quantities of NAA, N-acetylaspartylglutamate and choline compared to the CV animals. Of note is that, in both rat and mouse brain extracts, concentrations of hippocampal taurine were found to be greater in the absence of an established microbiome. The results provide further evidence that brain biochemistry can be influenced by gut microbial status, specifically metabolites involved in energy metabolism demonstrating biochemical dialogue between the microbiome and brain.

Metabolic Phenotyping of Diet and Dietary Intake.

Nutrition provides the building blocks for growth, repair, and maintenance of the body and is key to maintaining health. Exposure to fast foods, mass production of dietary components, and wider importation of goods have challenged the balance between diet and health in recent decades, and both scientists and clinicians struggle to characterize the relationship between this changing dietary landscape and human metabolism with its consequent impact on health. Metabolic phenotyping of foods, using high-density data-generating technologies to profile the biochemical composition of foods, meals, and human samples (pre- and postfood intake), can be used to map the complex interaction between the diet and human metabolism and also to assess food quality and safety. Here, we outline some of the techniques currently used for metabolic phenotyping and describe key applications in the food sciences, ending with a broad outlook at some of the newer technologies in the field with a view to exploring their potential to address some of the critical challenges in nutritional science.

HER2 status in breast cancer: experience of a Spanish National Reference Centre

BACKGROUND: Accurate HER2 testing is of great clinical value for the identification of breast cancer patients who are eligible for trastuzumab therapy. The aim of this study is to review breast carcinomas diagnosed from 2001 to 2007 at a Spanish National Reference Centre for HER2 testing, evaluating the agreement between HER2 immunohistochemical (IHC) tests and fluorescence in situ hybridisation (FISH) tests. METHODS: Demographic and clinical information was obtained from 2751 breast carcinoma patients. HER2 IHC and FISH tests were performed both in a local laboratory and in the reference centre. The HER2 IHC0/1+, IHC2+, IHC3+ and FISH-positive patients comprised 64%, 20%, 16% and 24% of the available population, respectively (results from the reference centre). Using statistical approaches, we evaluated the agreement between: (1) HER2 IHC and FISH tests, and (2) results provided by the local and the reference laboratories. RESULTS: The data confirmed a statistically significant relation between HER2 overexpression and amplification. We also found that instances of polysomy 17 and heterogeneous patterns of HER2 expression (heterogeneous staining distribution in different areas of the same tumour) are more frequently observed in HER2-positive tumours. Finally, since the diagnoses were made from 2001 to 2007, we could also observe a rising agreement rate between laboratories/pathologists with time. CONCLUSIONS: HER2 testing is most accurate when performed by experienced pathologists and at a high-volume reference laboratory. Polysomy 17 and HER2 heterogeneous staining patterns should also be considered for a better understanding of the variation in the anti-HER2 therapeutic response (AU)

Real-time RT-PCR analysis for evaluating the Her2/neu status in breast cancer.

OBJECTIVE: The Her2/neu status is of great clinical value in breast tumor patients. Fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC) techniques are the test of choice for many practicing pathologies. The main objective of this retrospective study was to investigate the relationship between Her2/neu breast cancer amplification and overexpression (DNA, mRNA and protein). METHODS: To accomplish this goal, we evaluated Her2/neu mRNA expression by real-time quantitative RT-PCR, gene amplification by FISH and protein expression by IHC. RESULTS: An excellent correlation between FISH and IHC Her2/neu results was observed, confirming that protein levels were directly related to DNA amplification. Polysomy 17 was frequently found in tumors showing Her2/neu overexpression. However, we did not find any statistically significant correlation among DNA, mRNA and protein levels, suggesting that Her2/neu could be post-transcriptionally regulated. CONCLUSIONS: There was a highagreement between Her2/neu gene amplification and protein overexpression but not mRNA expression levels. Nevertheless, IHC3+ and FISH-positive tumors indicated higher expression levels of Her2/neu mRNA by RT-PCR than those observed in IHC and FISH-negative tumors. These findings question the relevance of quantitative RT-PCR in routine assessment of Her2/neu overexpression in human breast cancer in the clinical laboratory setting.

Bidirectional correlation of NMR and capillary electrophoresis fingerprints: a new approach to investigating Schistosoma mansoni infection in a mouse model.

We demonstrate the statistical integration of nuclear magnetic resonance (NMR) spectroscopy and capillary electrophoresis (CE) data in order to describe a pathological state caused by Schistosoma mansoni infection in a mouse model based on urinary metabolite profiles. Urine samples from mice 53 days post infection with S. mansoni and matched controls were analyzed via NMR spectroscopy and CE. The two sets of metabolic profiles were first processed and analyzed independently and were subsequently integrated using statistical correlation methods in order to facilitate cross assignment of metabolites. Using this approach, metabolites such as 3-ureidopropionate, p-cresol glucuronide, phenylacetylglycine, indoxyl sulfate, isocitrate, and trimethylamine were identified as differentiating between infected and control animals. These correlation analyses facilitated structural elucidation using the identification power of one technique to enhance and validate the other, but also highlighted the enhanced ability to detect functional correlations between metabolites, thereby providing potential for achieving deeper mechanistic insight into the biological process.

Metabolic fingerprinting with capillary electrophoresis.

Increasingly biomedical studies require a top-down approach that can be achieved by comparing patterns, signatures or "fingerprints" of metabolites that change in response to disease, toxin exposure, environmental or genetic alterations. Capillary electrophoresis is a technique well suited for the analysis of biofluids and extracted tissue. The experimental design requires a multidisciplinary team comprising chemists, informaticians, medics, etc. Here we have reviewed the field of CE fingerprinting and organised the manuscript in four main blocks, Sample treatment is a discussion of the latest methods for extraction of compounds, Analytical methods, deals with the different versions of electrophoretic methods and detection instrumentation, Chemometrics and CE fingerprinting, explains algorithms that have been presented for peak alignment, normalization, data analysis and metabolite identification, and the Applications heading focuses in urine, plasma, organic matter and plant extract studies.

Esófago-diverticulostomía en el tratamiento del divertículo de Zenker / Esophagodiverticulostomy for the treatment of Zenker's diverticulum

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