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2.
Foods ; 12(6)2023 Mar 12.
Article in English | MEDLINE | ID: mdl-36981124

ABSTRACT

In this study, the feasibility of storing Marmande tomatoes (Solanum lycopersicum, cv Rojito) under hypobaric conditions was evaluated. The fruits were sorted into four lots of 72 fruits each. One lot was considered as a control, and the fruits were kept in the open box, while the fruits of the rest of the three remaining lots were enclosed in airtight containers and subjected to 101, 75 and 50 Kpa, respectively. Control fruits and airtight containers were kept at room temperature, and every three days from the beginning of the experiment the following main quality parameters were analysed: ethylene production rate, firmness, colour, total solids content, ascorbic acid, total phenolics and pigments, as well as a sensory analysis carried out by panellists. The results show that sub-atmospheric storage led a reduction in ethylene production, which was associated with a delay in ripening. The differences in the evolution of pigments were very significant, while a large degradation of chlorophylls was observed in the control fruits and in those kept at 101 kPa, in the fruits kept at 75 kPa and 50 kPa the degradation was much slower. In relation to carotenoid pigments, it was observed that sub-atmospheric treatments delayed their appearance compared to control and 101 kPa fruits. In relation to other quality parameters, it was found that control fruit and fruit held at 101 kPa softened more rapidly than fruit under sub-atmospheric conditions, whose loss of firmness was more gradual with differences found only at 9 and 12 days of storage with respect to fruit firmness at harvest. The appearance of these fruits was evaluated with the same score as at the time of harvesting, during 9 of the 12 days of the experiment, then a positive effect of sub-atmospheric treatments was also found in the sensory analysis. The results suggest that sub-atmospheric storage could be a suitable method of increasing the shelf-life of fruits.

3.
J Exp Psychol Anim Learn Cogn ; 48(1): 29-45, 2022 Jan.
Article in English | MEDLINE | ID: mdl-35143243

ABSTRACT

Three experiments (a, b, c) combined to provide a well-powered examination of the effects of stimulus pre-exposure and conditioning on visual attention using an eye tracker and a space-shooter video game where a colored flashing light predicted an attacking spaceship. In each, group "control" received no pre-exposure to the light, group "same" received pre-exposure in the same context as conditioning, and group "different" received pre-exposure in a different context. Experiments differed in visual details regarding the game (1a vs. 1b and 1c) or minor details in the setup of the eye tracker (1a and 1b vs. 1c). Overall, pre-exposure retarded acquisition of keyboard responding. That effect was enhanced, rather than attenuated, by a context change. Separating participants by sign and goal trackers showed the context change enhanced the pre-exposure effect in goal trackers and reduced it in sign trackers. Visual attention to the light declined during pre-exposure and did not recover with either conditioning or a context switch. Visual attention to the light decreased during conditioning. Visual goal tracking toward where the spaceship would appear was also retarded with pre-exposure. Unlike the keyboard responding, a context change led to more normal goal-tracking acquisition. Results are discussed in terms of theories of attention and the potential effects of demand characteristics on the task. (PsycInfo Database Record (c) 2022 APA, all rights reserved).


Subject(s)
Conditioning, Classical , Psychomotor Performance , Humans , Motivation
4.
Pharmaceutics ; 13(9)2021 Sep 15.
Article in English | MEDLINE | ID: mdl-34575549

ABSTRACT

Modifying hydrogels in order to enhance their conductivity is an exciting field with applications in cardio and neuro-regenerative medicine. Therefore, we have designed hybrid alginate hydrogels containing uncoated and protein-coated reduced graphene oxide (rGO). We specifically studied the adsorption of three different proteins, BSA, elastin, and collagen, and the outcomes when these protein-coated rGO nanocomposites are embedded within the hydrogels. Our results demonstrate that BSA, elastin, and collagen are adsorbed onto the rGO surface, through a non-spontaneous phenomenon that fits Langmuir and pseudo-second-order adsorption models. Protein-coated rGOs are able to preclude further adsorption of erythropoietin, but not insulin. Collagen showed better adsorption capacity than BSA and elastin due to its hydrophobic nature, although requiring more energy. Moreover, collagen-coated rGO hybrid alginate hydrogels showed an enhancement in conductivity, showing that it could be a promising conductive scaffold for regenerative medicine.

5.
J Exp Psychol Anim Learn Cogn ; 47(2): 104-119, 2021 Apr.
Article in English | MEDLINE | ID: mdl-34264718

ABSTRACT

Two experiments with humans determined whether reduced conditioning following pre-exposure to the conditioned stimulus could be explained by conditioned inhibition (Experiment 1 [E1]) or extinction of responding that the conditioned stimulus (CS) might elicit during pre-exposure (Experiment 2 [E2]). In a video game task (Nelson et al., 2014), participants learned to respond to lights that signaled attacking spaceships. In E1, a red light was either pre-exposed or not pre-exposed between groups prior to conditioning with a green light. Summation tests of red combined with green produced no evidence of conditioned inhibition. In E2, participants received either no pre-exposure to the light, exposure in the same context in which the conditioning would occur, or exposure in a different context. These conditions were factorially combined with whether the light and spaceship were similar (same color) or dissimilar (different colors). In the similar conditions, the light elicited weak responding during pre-exposure, which extinguished. Such extinction did not occur in the dissimilar conditions. Conditioning occurred more rapidly in the similar conditions than in the dissimilar ones, but both conditions showed an equivalent context-dependent pre-exposure effect. Pre-exposure reduced conditioning regardless of whether it reduced responding prior to conditioning. The data are consistent with animal research (Lubow et al., 1968) showing no relation between responding during pre-exposure and the effects of stimulus pre-exposure. Theories which account for the effects of stimulus pre-exposure are discussed, with the conclusion that the data are most consistent with the ideas presented by Wagner (1981). (PsycInfo Database Record (c) 2021 APA, all rights reserved).


Subject(s)
Conditioning, Classical , Extinction, Psychological , Animals , Conditioning, Operant , Humans
6.
Data Brief ; 34: 106681, 2021 Feb.
Article in English | MEDLINE | ID: mdl-33426241

ABSTRACT

Distribution area and surface are both parameters of paramount importance for habitat management, monitoring and conservation. Here we present the distribution of eight zonal forest types of mainland Spain that are consistent with the Habitat Types (HT) listed in Annex I of the European Union Habitats Directive 92/43 EC. Their dominant species and HT codes are Fagus sylvatica (9120, 9130 and 9150), Quercus robur and Q. pyrenaica (9230), Q. suber (9330), Pinus uncinata (9430), P. nigra ssp. salzmannii (9530) and P. pinea (subset of 9540). These distributions are based on tesserae from the 1:50,000 Spanish Forest Map and are the result of sorting assisted by supplementary databases. The distributions are presented as vector coverages, and provide three information levels of increasing detail: geographic distribution, basic forest type and structural forest patch. Two R scripts are also included with the dataset. They implement a segmented regression approach to investigate forest fragmentation on these or other patch-like data.

7.
J Exp Psychol Anim Learn Cogn ; 46(4): 422-442, 2020 Oct.
Article in English | MEDLINE | ID: mdl-33030954

ABSTRACT

The renewal effect is often explained as a side effect of the extinction context acting as a negative occasion setter. Four experiments tested whether extinction contexts show the selective-transfer property of occasion setters. Experiments 1-3 used a predictive judgment task where participants rated the probability of certain foods (cues) producing gastric malaise (outcomes) in different restaurants (contexts). Experiment 4 used a behavioral suppression task where sensor lights (cues) served as signals to suppress firing responses in certain galaxies (contexts). All 4 (Experiments 1-4) addressed whether a potentially negative occasion-setting context transferred its modulatory power to an extinguished (presumably occasion set) target in the test phase of an ABC renewal design. Experiments 2-4 further assessed the possibility that the extinction context acts as a conditioned inhibitor by testing a simple excitor on a context where extinction occurred. Neither selective (occasion-setting) nor nonselective transfer (conditioned inhibition) was demonstrated. Implications for theories of renewal and occasion-setting are discussed. (PsycInfo Database Record (c) 2020 APA, all rights reserved).


Subject(s)
Conditioning, Classical/physiology , Extinction, Psychological/physiology , Inhibition, Psychological , Transfer, Psychology/physiology , Adult , Cues , Female , Humans , Male , Psychomotor Performance/physiology , Young Adult
8.
Pharmaceutics ; 12(6)2020 06 11.
Article in English | MEDLINE | ID: mdl-32545286

ABSTRACT

The use of embedded cells within alginate matrices is a developing technique with great clinical applications in cell-based therapies. However, one feature that needs additional investigation is the improvement of alginate-cells viability, which could be achieved by integrating other materials with alginate to improve its surface properties. In recent years, the field of nanotechnology has shown the many properties of a huge number of materials. Graphene oxide (GO), for instance, seems to be a good choice for improving alginate cell viability and functionality. We previously observed that GO, coated with fetal bovine serum (FBS) within alginate hydrogels, improves the viability of embedded myoblasts. In the current research, we aim to study several proteins, specifically bovine serum albumin (BSA), type I collagen and elastin, to discern their impact on the previously observed improvement on embedded myoblasts within alginate hydrogels containing GO coated with FBS. Thus, we describe the mechanisms of the formation of BSA, collagen and elastin protein layers on the GO surface, showing a high adsorption by BSA and elastin, and a decreasing GO impedance and capacitance. Moreover, we described a better cell viability and protein release from embedded cells within hydrogels containing protein-coated GO. We conclude that these hybrid hydrogels could provide a step forward in regenerative medicine.

9.
ACS Appl Mater Interfaces ; 12(14): 16436-16441, 2020 Apr 08.
Article in English | MEDLINE | ID: mdl-32182419

ABSTRACT

Membranes are a critical technology for energy-efficient separation processes. The routine method of evaluating membrane performance is a permeation measurement. However, such measurements can be limited in terms of their utility: membrane microstructure is often poorly characterized; membranes or sealants leak; and conditions in the gas phase are poorly controlled and frequently far-removed from the conditions employed in the majority of real processes. Here, we demonstrate a new integrated approach to determine permeation rates, using two novel supported molten-salt membrane geometries. In both cases, the membranes comprise a solid support with laser-drilled pores, which are infiltrated with a highly CO2-selective molten carbonate salt. First, we fabricate an optically transparent single-crystal, single-pore model membrane by local laser drilling. By infiltrating the single pore with molten carbonate, monitoring the gas-liquid interface optically, and using image analysis on gas bubbles within the molten carbonate (because they change volume upon controlled changes in gas composition), we extract CO2 permeation rates with exceptional speed and precision. Additionally, in this arrangement, microstructural characterization is more straightforward and a sealant is not required, eliminating a major source of leakage. Furthermore, we demonstrate that the technique can be used to probe a previously unexplored driving force region, too low to access with conventional methods. Subsequently, we fabricate a leak-free tubular-supported molten-salt membrane with 1000 laser-drilled pores (infiltrated with molten carbonate) and employ a CO2-containing sweep gas to obtain permeation rates in a system that can be described with unprecedented precision. Together, the two approaches provide new ways to measure permeation rates with increased speed and at previously inaccesible conditions.

10.
Behav Processes ; 164: 237-251, 2019 Jul.
Article in English | MEDLINE | ID: mdl-31100330

ABSTRACT

Two experiments used eye tracking to examine visual searching for expected outcomes in humans during an associative-learning task. In both, participants learned to press keys on a keyboard to activate weapons to repel invading spaceships in the presence of predictive "sensors." In both experiments, eye tracking showed that participants came to direct their overt visual attention to the portions of the screen where the spaceship would arrive during the presentation of the sensor in a cue-specific manner. Participants also directed attention to the weapon that was used to repel the spaceship. The same results were observed regardless of whether participants were responding on the keyboard, or not (Experiment 2). Pupil dilations occurred to the appearance of the spaceship from the first trial and occurred to the predictive sensor stimuli on later trials in both experiments, suggesting that they might be conditioned responses. In Experiment 2 participants again looked for the expected outcome, but dilations to the predictive stimuli were shown to be an artifact of responding and not due to conditioning. The discussion involves the implications for investigating attention to predictive stimuli using eye trackers, roles of context in behavior, and the utility of outcome searching and pupil dilations as indexes of learning.


Subject(s)
Anticipation, Psychological/physiology , Attention/physiology , Conditioning, Classical , Adult , Cues , Eye Movements/physiology , Female , Humans , Male , Pupil/physiology , Young Adult
11.
IUCrJ ; 6(Pt 1): 128-135, 2019 Jan 01.
Article in English | MEDLINE | ID: mdl-30713710

ABSTRACT

The first fluorination of the cuspidine-related phases of Ln4(Al2O7□)O2 (where Ln = Sm, Eu, Gd) is reported. A low-temperature reaction with poly(vinyl-idene difluoride) lead to the fluorine being substituted in place of oxygen and inserted into the vacant position between the dialuminate groups. X-ray photoelectron spectroscopy shows the presence of the F 1s photoelectron together with an increase in Al 2p and rare-earth 4d binding energies supporting F incorporation. Energy-dispersive X-ray spectroscopy analyses are consistent with the formula Ln4(Al2O6F2)O2, confirming that substitution of one oxygen by two fluoride atoms has been achieved. Rietveld refinements show an expansion in the cell upon fluorination and confirm that the incorporation of fluoride in the Ln4(Al2O7□)O2 structure results in changes in Al coordination from four to five. Thus, the isolated tetrahedral dialuminate Al2O7 groups are converted to chains of distorted square-based pyramids. These structural results are also discussed based on Raman spectra.

12.
Neuroscience ; 420: 12-21, 2019 11 10.
Article in English | MEDLINE | ID: mdl-30458218

ABSTRACT

Soluble N-ethylmaleimide sensitive factor attachment protein receptor (SNARE) proteins mediate membrane fusion events in eukaryotic cells. Traditionally recognized as major players in regulating presynaptic neurotransmitter release, accumulative evidence over recent years has identified several SNARE proteins implicated in important postsynaptic processes such as neurotransmitter receptor trafficking and synaptic plasticity. Here we analyze the emerging data revealing this novel functional dimension for SNAREs with a focus on the molecular specialization of vesicular recycling and fusion in dendrites compared to those at axon terminals and its impact in synaptic transmission and plasticity.


Subject(s)
Neuronal Plasticity/physiology , Neurons/metabolism , SNARE Proteins/metabolism , Synaptic Transmission/physiology , Animals , Humans
13.
Food Sci Nutr ; 6(8): 2066-2078, 2018 Nov.
Article in English | MEDLINE | ID: mdl-30510708

ABSTRACT

BACKGROUND: Organic soilless production in containers requires substrates with appropriate physicochemical and biological properties to ensure that production is sustainable and profitable for several production cycles. The main objective of this study was to comprehensively evaluate these properties in three different mixtures of organic substrates (vermicompost [V] and coconut fibers [CF] in ratios 20V80CF, 40V60CF, 60V40CF) for four horticultural crop production cycles (PCs) using vermicompost tea (VT) as the main source of nutrients. RESULTS: Readily available water (25%) in the control treatment (20V80CF) was below the recommended limit, and dry bulk density (>450 g/L) surpassed the recommended limit in the 60V40CF treatment (p < 0.05). In terms of chemical properties, cations and anions in the saturated media extract decreased significantly to values below established optimal conditions. Furthermore, the substrates presented high enzymatic activity in successive production cycles (p < 0.05), including dehydrogenase (350-400 µg TFF g-1), acid phosphatase (4,700 µg p-nitrophenol g-1 soil hr-1), and ß-glucosidase (1,200 µg p-nitrophenol g-1 soil hr-1) activity during transformation from organic matter to inorganic compounds. CONCLUSION: The 40V60CF treatment presents adequate physicochemical and biological characteristics for reuse for more than four growing cycles when organic supplements are administered.

14.
Behav Processes ; 157: 148-160, 2018 Dec.
Article in English | MEDLINE | ID: mdl-30261206

ABSTRACT

Learning to Learn (LTL) is the transfer of learning, separate from stimulus generalization, that appears across tasks that share a similar structure. Three experiments examined this phenomenon in both conditioning and extinction learning in humans. The latter effect is of special interest given the failures in the literature to obtain transfer of extinction between stimuli. Conditioning and extinction with one stimulus increased the rate of conditioning and, surprisingly, extinction of a different stimulus (Experiment 1). The effects appeared in the absence of physical generalization. The transfer of extinction was not enhanced by conditions that increased the chances of a mediated extinction effect (Experiment 2). Finally, Experiment 3 ruled out three possible sources for the effect in extinction: a common unconditioned-stimulus representation, a common reinforcement history, and within-stimuli associations. Overall, the findings are consistent with the idea that LTL is an emergent (non-immediate) form of mediated generalization that is dependent upon memory structures retrieved by trial outcomes. The over- or under-prediction of the outcome on the first trial with a new task might retrieve prior episodes associated with similar prediction errors promoting transfer.


Subject(s)
Conditioning, Classical , Extinction, Psychological , Learning , Adolescent , Conditioning, Operant , Female , Humans , Male , Reinforcement, Psychology , Transfer, Psychology , Young Adult
15.
J Vasc Bras ; 17(1): 3-9, 2018.
Article in English | MEDLINE | ID: mdl-29930675

ABSTRACT

BACKGROUND: Endovascular treatment (ET) of iliac occlusive disease (IOD) is well established in literature. Use of stents in IOD has achieved long-term limb salvage and patency rates similar to those of open surgery, with lower morbidity and mortality rates. OBJECTIVES: To report the long-term outcomes, particularly limb salvage and patency rates, of ET for IOD and the factors associated with these outcomes. METHODS: This retrospective cohort study included patients with IOD who underwent iliac angioplasty (IA), between January 2009 and January 2015. Patients with critical limb ischemia or incapacitating claudication were included. RESULTS: In total, 48 IA procedures were performed in 46 patients, with an initial technical success rate of 95.83%. Failure occurred in two patients, who were excluded, leaving 44 patients and 46 IA. The primary patency, secondary patency, limb salvage, and survival rates at 1200 days were 88%, 95.3%, 86.3%, and 69.9%, respectively. Univariate and multivariate Cox regression revealed that the primary patency rate was significantly worse in patients with TASC type C/D than in patients with TASC type A/B (p = 0.044). Analysis of factors associated with major amputation using Cox regression showed that the rate of limb loss was greater in patients with TASC type C/D (p = 0.043). Male gender was associated with reduced survival (p = 0.011). CONCLUSIONS: TASC type C/D was associated with a higher number of reinterventions and with worse limb loss and primary patency rates. Male gender was associated with a worse survival rate after ET of IOD.


CONTEXTO: O tratamento endovascular da doença oclusiva ilíaca (DOI) é bem estabelecido. O uso de stents nas angioplastias ilíacas (AI) alcançou estimativas de salvamento de membro e perviedade similares às de cirurgias abertas, porém com menor morbimortalidade. OBJETIVOS: Demonstrar os desfechos clínicos a longo prazo, principalmente as estimativas de salvamento de membro (ESM) e perviedade, do tratamento endovascular da DOI e os fatores associados. MÉTODO: Estudo de coorte retrospectiva e consecutiva incluindo pacientes com DOI e isquemia crítica ou claudicação limitante submetidos a AI entre janeiro de 2009 a janeiro de 2015. RESULTADOS: Foram realizadas 48 AI em 46 pacientes, com uma taxa de sucesso técnico inicial de 95,83%. Ocorreu falha técnica em dois pacientes, os quais foram excluídos da análise, restando 44 pacientes e 46 AI. As estimativas de perviedade primária, perviedade secundária, ESM e sobrevida aos 1.200 dias foram de 88%, 95,3%, 86,3% e 69,9%, respectivamente. A regressão de Cox univariada e multivariada revelou que a perviedade primária foi pior em pacientes com classificação TASC C/D do que em pacientes TASC A/B (p = 0,044). Quando analisamos os fatores associados à amputação maior, verificou-se que lesões TASC tipo C/D (p = 0,043) apresentaram piores resultados. O sexo masculino foi associado com sobrevida reduzida (p = 0,011). CONCLUSÕES: Classificação TASC tipo C/D foi associada a um maior número de reintervenções, maior perda de membro e piores estimativas de perviedade primária. O sexo masculino foi associado a uma pior sobrevida.

16.
J. vasc. bras ; 17(1): 3-9, jan.-mar. 2018. tab, graf
Article in English | LILACS | ID: biblio-894155

ABSTRACT

Abstract Background Endovascular treatment (ET) of iliac occlusive disease (IOD) is well established in literature. Use of stents in IOD has achieved long-term limb salvage and patency rates similar to those of open surgery, with lower morbidity and mortality rates. Objectives To report the long-term outcomes, particularly limb salvage and patency rates, of ET for IOD and the factors associated with these outcomes. Methods This retrospective cohort study included patients with IOD who underwent iliac angioplasty (IA), between January 2009 and January 2015. Patients with critical limb ischemia or incapacitating claudication were included. Results In total, 48 IA procedures were performed in 46 patients, with an initial technical success rate of 95.83%. Failure occurred in two patients, who were excluded, leaving 44 patients and 46 IA. The primary patency, secondary patency, limb salvage, and survival rates at 1200 days were 88%, 95.3%, 86.3%, and 69.9%, respectively. Univariate and multivariate Cox regression revealed that the primary patency rate was significantly worse in patients with TASC type C/D than in patients with TASC type A/B (p = 0.044). Analysis of factors associated with major amputation using Cox regression showed that the rate of limb loss was greater in patients with TASC type C/D (p = 0.043). Male gender was associated with reduced survival (p = 0.011). Conclusions TASC type C/D was associated with a higher number of reinterventions and with worse limb loss and primary patency rates. Male gender was associated with a worse survival rate after ET of IOD.


Resumo Contexto O tratamento endovascular da doença oclusiva ilíaca (DOI) é bem estabelecido. O uso de stents nas angioplastias ilíacas (AI) alcançou estimativas de salvamento de membro e perviedade similares às de cirurgias abertas, porém com menor morbimortalidade. Objetivos Demonstrar os desfechos clínicos a longo prazo, principalmente as estimativas de salvamento de membro (ESM) e perviedade, do tratamento endovascular da DOI e os fatores associados. Método Estudo de coorte retrospectiva e consecutiva incluindo pacientes com DOI e isquemia crítica ou claudicação limitante submetidos a AI entre janeiro de 2009 a janeiro de 2015. Resultados Foram realizadas 48 AI em 46 pacientes, com uma taxa de sucesso técnico inicial de 95,83%. Ocorreu falha técnica em dois pacientes, os quais foram excluídos da análise, restando 44 pacientes e 46 AI. As estimativas de perviedade primária, perviedade secundária, ESM e sobrevida aos 1.200 dias foram de 88%, 95,3%, 86,3% e 69,9%, respectivamente. A regressão de Cox univariada e multivariada revelou que a perviedade primária foi pior em pacientes com classificação TASC C/D do que em pacientes TASC A/B (p = 0,044). Quando analisamos os fatores associados à amputação maior, verificou-se que lesões TASC tipo C/D (p = 0,043) apresentaram piores resultados. O sexo masculino foi associado com sobrevida reduzida (p = 0,011). Conclusões Classificação TASC tipo C/D foi associada a um maior número de reintervenções, maior perda de membro e piores estimativas de perviedade primária. O sexo masculino foi associado a uma pior sobrevida.


Subject(s)
Humans , Male , Female , Middle Aged , Aged , Arterial Occlusive Diseases/surgery , Endovascular Procedures , Iliac Artery , Sex Factors , Retrospective Studies , Angioplasty , Limb Salvage , Chronic Limb-Threatening Ischemia/surgery , Amputation, Surgical
17.
Sci Total Environ ; 613-614: 1489-1497, 2018 Feb 01.
Article in English | MEDLINE | ID: mdl-28802894

ABSTRACT

This work illustrates the application of a simulation model to analyse how swiftly large-scale land-use changes can drive broad territories to collapse. In this sense, the economic needs of a population should not clash with the natural environment but rather be reconciled with it. Abundant literature deals with the integration of socioeconomic drivers, ecological aspects, farming management, and climatology related to Algerian rangeland degradation. The present study seeks to compare the time course of Alfa grass biomass and the livestock raised on these distinctive rangelands under two different land-use strategies. The traditional one has nomads as the main inhabitants of these lands. For centuries, their strategy for alleviating pressure on resources was to move from one area to other. The more recent sedentary land-use leads to overgrazing supported by the massive use of cheap supplemental feed. Additionally, the model was used as a platform to launch scenarios for sustainable land-use management under a competitive market-economy. A key finding for preserving grazing resources was the increment of supplemental feed prices, which is compatible with stocking rates higher than the historical ones.

19.
Oncotarget ; 8(12): 19522-19533, 2017 Mar 21.
Article in English | MEDLINE | ID: mdl-28076849

ABSTRACT

PURPOSE: Metabolomics is the comprehensive global study of metabolites in biological samples. In this retrospective pilot study we explored whether serum metabolomic profile can discriminate the presence of human breast cancer irrespective of the cancer subtype. METHODS: Plasma samples were analyzed from healthy women (n = 20) and patients with breast cancer after diagnosis (n = 91) using a liquid chromatography-mass spectrometry platform. Multivariate statistics and a Random Forest (RF) classifier were used to create a metabolomics panel for the diagnosis of human breast cancer. RESULTS: Metabolomics correctly distinguished between breast cancer patients and healthy control subjects. In the RF supervised class prediction analysis comparing breast cancer and healthy control groups, RF accurately classified 100% both samples of the breast cancer patients and healthy controls. So, the class error for both group in and the out-of-bag error were 0. We also found 1269 metabolites with different concentration in plasma from healthy controls and cancer patients; and basing on exact mass, retention time and isotopic distribution we identified 35 metabolites. These metabolites mostly support cell growth by providing energy and building stones for the synthesis of essential biomolecules, and function as signal transduction molecules. The collective results of RF, significance testing, and false discovery rate analysis identified several metabolites that were strongly associated with breast cancer. CONCLUSIONS: In breast cancer a metabolomics signature of cancer exists and can be detected in patient plasma irrespectively of the breast cancer type.


Subject(s)
Biomarkers, Tumor/blood , Breast Neoplasms/blood , Breast Neoplasms/diagnosis , Metabolome , Metabolomics/methods , Plasma/metabolism , Case-Control Studies , Female , Follow-Up Studies , Gas Chromatography-Mass Spectrometry , Humans , Pilot Projects , Retrospective Studies
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