Papers by luciano valenzuela
PLOS One, 2010
While isotopes are frequently used as tracers in investigations of disease physiology (i.e., 14 C... more While isotopes are frequently used as tracers in investigations of disease physiology (i.e., 14 C labeled glucose), few studies have examined the impact that disease, and disease-related alterations in metabolism, may have on stable isotope ratios at natural abundance levels. The isotopic composition of body water is heavily influenced by water metabolism and dietary patterns and may provide a platform for disease detection. By utilizing a model of streptozotocin (STZ)-induced diabetes as an index case of aberrant water homeostasis, we demonstrate that untreated diabetes mellitus results in distinct combinations, or signatures, of the hydrogen (d 2 H) and oxygen (d 18 O) isotope ratios in body water. Additionally, we show that the d 2 H and d 18 O values of body water are correlated with increased water flux, suggesting altered blood osmolality, due to hyperglycemia, as the mechanism behind this correlation. Further, we present a mathematical model describing the impact of water flux on the isotopic composition of body water and compare model predicted values with actual values. These data highlight the importance of factors such as water flux and energy expenditure on predictive models of body water and additionally provide a framework for using naturally occurring stable isotope ratios to monitor diseases that impact water homeostasis. Citation: O'Grady SP, Wende AR, Remien CH, Valenzuela LO, Enright LE, et al. (2010) Aberrant Water Homeostasis Detected by Stable Isotope Analysis. PLoS ONE 5(7): e11699.
Journal of Agricultural and Food Chemistry, 2010
This study investigated the impact of purchase location on the stable isotope ratios of beverages... more This study investigated the impact of purchase location on the stable isotope ratios of beverages by measuring the δ 2 H and δ 18 O values of bottled water, soda, beer, and tap water collected across the contiguous United States. Measured beverage δ 2 H and δ 18 O values generally fit the Global Meteoric Water Line (GMWL), suggesting region-of-origin information is recorded in beverage water. Tap water δ 2 H and δ 18 O values were strongly correlated with the stable isotope ratios of bottled water and soda purchased in the same location. Beer water δ 2 H and δ 18 O values were also correlated with tap water, although not as strongly. Variability in δ 2 H and δ 18 O values among beverages purchased at a single location ranged from 2 to 41% and from 0.3 to 5.2%, respectively, but was generally moderate in most locations. It was concluded that the isotopic composition of local tap water is a reasonable proxy for consumers' fluid intake in most U.S. cities.
Journal of Agricultural and Food Chemistry, 2010
Models of hydrogen and oxygen incorporation in human tissues recognize the impact of geographic l... more Models of hydrogen and oxygen incorporation in human tissues recognize the impact of geographic location on the isotopic composition of fluid intake, but inputs can include nonlocal beverages, such as milk. Milk and cow drinking water were collected from dairies, and commercially available milk was purchased from supermarkets and fast food restaurants. It was hypothesized that milk water δ 2 H and δ 18 O values record geographic location information. Correlations between milk water isotope ratios and purchase location tap water were significant. However, the amount of variation in milk δ 2 H and δ 18 O values explained by tap water was low, suggesting a single estimation of fluid input isotope ratios may not always be adequate in studies. The δ 2 H and δ 18 O values of paired milk and cow drinking water were related, suggesting potential for geographical origin assignment using stable isotope analysis. As an application example, milk water δ 18 O values were used to predict possible regions of origin for restaurant samples.
PLOS One, 2012
Although the globalization of food production is often assumed to result in a homogenization of c... more Although the globalization of food production is often assumed to result in a homogenization of consumption patterns with a convergence towards a Western style diet, the resources used to make global food products may still be locally produced (glocalization). Stable isotope ratios of human hair can quantify the extent to which residents of industrialized nations have converged on a standardized diet or whether there is persistent heterogeneity and glocalization among countries as a result of different dietary patterns and the use of local food products. Here we report isotopic differences among carbon, nitrogen and sulfur isotope ratios of human hair collected in thirteen Western European countries and in the USA. European hair samples had significantly lower d 13 C values (222.7 to 218.3%), and significantly higher d 15 N (7.8 to 10.3%) and d 34 S (4.8 to 8.3%) values than samples from the USA (d 13 C: 221.9 to 215.0%, d 15 N: 6.7 to 9.9%, d 34 S: 21.2 to 9.9%). Within Europe, we detected differences in hair d 13 C and d 34 S values among countries and covariation of isotope ratios with latitude and longitude. This geographic structuring of isotopic data suggests heterogeneity in the food resources used by citizens of industrialized nations and supports the presence of different dietary patterns within Western Europe despite globalization trends. Here we showed the potential of stable isotope analysis as a population-wide tool for dietary screening, particularly as a complement of dietary surveys, that can provide additional information on assimilated macronutrients and independent verification of data obtained by those self-reporting instruments.
PLOS One, 2010
While isotopes are frequently used as tracers in investigations of disease physiology (i.e., 14 C... more While isotopes are frequently used as tracers in investigations of disease physiology (i.e., 14 C labeled glucose), few studies have examined the impact that disease, and disease-related alterations in metabolism, may have on stable isotope ratios at natural abundance levels. The isotopic composition of body water is heavily influenced by water metabolism and dietary patterns and may provide a platform for disease detection. By utilizing a model of streptozotocin (STZ)-induced diabetes as an index case of aberrant water homeostasis, we demonstrate that untreated diabetes mellitus results in distinct combinations, or signatures, of the hydrogen (d 2 H) and oxygen (d 18 O) isotope ratios in body water. Additionally, we show that the d 2 H and d 18 O values of body water are correlated with increased water flux, suggesting altered blood osmolality, due to hyperglycemia, as the mechanism behind this correlation. Further, we present a mathematical model describing the impact of water flux on the isotopic composition of body water and compare model predicted values with actual values. These data highlight the importance of factors such as water flux and energy expenditure on predictive models of body water and additionally provide a framework for using naturally occurring stable isotope ratios to monitor diseases that impact water homeostasis. Citation: O'Grady SP, Wende AR, Remien CH, Valenzuela LO, Enright LE, et al. (2010) Aberrant Water Homeostasis Detected by Stable Isotope Analysis. PLoS ONE 5(7): e11699.
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Papers by luciano valenzuela