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1.
J Sep Sci ; 47(9-10): e2400142, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38726732

RESUMEN

Catechins, renowned for their antioxidant properties and health benefits, are commonly present in beverages, particularly tea and wine. An efficient and cost-effective salting-out assisted liquid-liquid extraction (SALLE) method has been developed and validated for the simultaneous determination of six catechins and caffeine in tea and wine samples using high-performance liquid chromatography-ultraviolet (HPLC-UV). This method demonstrates outstanding performance: linearity (1-120 µg/mL, r2 > 0.999), accuracy (96.5%-103.4% recovery), and precision (≤14.7% relative standard deviation), meeting validation requirements set by the US Food and Drug Administration. The reduced sample size (0.1 g) minimizes matrix interferences and costs without compromising sensitivity. All analytes were detected in Camellia sinensis teas, with green tea displaying the highest total catechin content (47.5-100.1 mg/mL), followed by white and black teas. Analysis of wine samples reveals the presence of catechin in all red and white wines, and epigallocatechin gallate in all red wine samples, highlighting the impact of winemaking processes on catechin content. The SALLE-HPLC-UV approach represents a green alternative by eliminating organic waste, surpassing conventional dilution methods in specificity and sensitivity for catechin determination. AGREEprep assessment emphasizes the strengths of the SALLE procedure, including material reusability, throughput efficiency, minimal sample requirements, low energy consumption, and the absence of organic waste generation.


Asunto(s)
Cafeína , Catequina , Extracción Líquido-Líquido , , Vino , Cromatografía Líquida de Alta Presión/métodos , Vino/análisis , Cafeína/análisis , Catequina/análisis , Té/química , Extracción Líquido-Líquido/métodos , Espectrofotometría Ultravioleta , Rayos Ultravioleta
2.
Molecules ; 29(8)2024 Apr 11.
Artículo en Inglés | MEDLINE | ID: mdl-38675555

RESUMEN

Anthocyanins, a subclass of flavonoids known for their vibrant colors and health-promoting properties, are pivotal in the nutritional science and food industry. This review article delves into the analytical methodologies for anthocyanin detection and quantification in food matrices, comparing quantitative and topical techniques. Quantitative methods, including High-performance Liquid Chromatography (HPLC) and Mass Spectrometry (MS), offer precise quantification and profiling of individual anthocyanins but require sample destruction, limiting their use in continuous quality control. Topical approaches, such as Near-infrared Spectroscopy (NIR) and hyperspectral imaging, provide rapid, in situ analysis without compromising sample integrity, ideal for on-site food quality assessment. The review highlights the advancements in chromatographic techniques, particularly Ultra-high-performance Liquid Chromatography (UHPLC) coupled with modern detectors, enhancing resolution and speed in anthocyanin analysis. It also emphasizes the growing importance of topical techniques in the food industry for their efficiency and minimal sample preparation. By examining the strengths and limitations of both analytical realms, this article aims to shed light on current challenges and prospective advancements, providing insights into future research directions for improving anthocyanin analysis in foods.


Asunto(s)
Antocianinas , Análisis de los Alimentos , Antocianinas/análisis , Antocianinas/química , Cromatografía Líquida de Alta Presión/métodos , Análisis de los Alimentos/métodos , Espectrometría de Masas/métodos , Espectroscopía Infrarroja Corta/métodos
3.
Gen Dent ; 71(2): 36-41, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36825972

RESUMEN

Maxillofacial defects created by the surgical resection of a tumor negatively impact the mastication, phonation, swallowing, and psychological function of patients. A 68-year-old woman received a diagnosis of oral squamous cell carcinoma involving the hard palate. The hemimaxillectomy procedure for tumor resection created a defect on the left side of the palate. This case report describes the patient's cancer treatment from presurgical planning to final rehabilitation with a conventional obturator and subsequent follow-up care for 1 year. The rehabilitation strategy was satisfactory for the patient, reestablishing lost function and esthetics.


Asunto(s)
Carcinoma de Células Escamosas , Neoplasias de la Boca , Femenino , Humanos , Anciano , Obturadores Palatinos , Paladar Duro
4.
Cell Tissue Res ; 387(2): 261-274, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-34816282

RESUMEN

Circadian rhythms are those variations in behavioral and molecular processes of organisms that follow roughly 24 h cycles in the absence of any external cue. The hypothalamic suprachiasmatic nucleus (SCN) harbors the principal brain pacemaker driving circadian rhythms. The epithalamic habenula (Hb) contains a self-sustained circadian clock functionally coupled to the SCN. Anatomically, the Hb projects to the midbrain dopamine (DA) and serotonin (5-HT) systems, and it receives inputs from the forebrain, midbrain, and brainstem. The SCN is set by internal signals such as 5-HT or melatonin from the raphe nuclei and pineal gland, respectively. However, how the Hb clock is set by internal cues is not well characterized. Hence, in the present study, we determined whether DA, noradrenaline (NA), 5-HT, and the neuropeptides orexin (ORX) and vasopressin influence the Hb circadian clock. Using PER2::Luciferase transgenic mice, we found that the amplitude of the PER2 protein circadian oscillations from Hb explants was strongly affected by DA and NA. Importantly, these effects were dose-and region (rostral vs. caudal) dependent for NA, with a main effect in the caudal part of the Hb. Furthermore, ORX also induced a significant change in the amplitude of PER2 protein oscillations in the caudal Hb. In conclusion, catecholaminergic (DA, NA) and ORXergic transmission impacts the clock properties of the Hb clock likely contributing to the circadian regulation of motivated behaviors. Accordingly, pathological conditions that lead in alterations of catecholamine or ORX activity (drug intake, compulsive feeding) might affect the Hb clock and conduct to circadian disturbances.


Asunto(s)
Relojes Circadianos , Habénula , Animales , Catecolaminas/metabolismo , Ritmo Circadiano , Habénula/metabolismo , Ratones , Ratones Transgénicos , Proteínas Circadianas Period/genética , Proteínas Circadianas Period/metabolismo , Núcleo Supraquiasmático/metabolismo
5.
Exp Eye Res ; 213: 108807, 2021 12.
Artículo en Inglés | MEDLINE | ID: mdl-34695438

RESUMEN

The retinal circadian system consists of a network of clocks located virtually in every retinal cell-type. Although it is established that the circadian clock regulates many rhythmic processes in the retina, the links between retinal cell-specific clocks and visual function remain to be elucidated. Bmal1 is a principal, non-redundant component of the circadian clock in mammals and is required to keep 24 h rhythms in the retinal transcriptome and in visual processing under photopic light condition. In the current study, we investigated the retinal function in mice with a rod-specific knockout of Bmal1. For this purpose, we measured whole retina PER2::Luciferase bioluminescence and the dark-adapted electroretinogram (ERG). We observed circadian day-night differences in ERG a- and b-waves in control mice carrying one allele of Bmal1 in rods, with higher amplitudes during the subjective night. These differences were abolished in rod-specific Bmal1 knockout mice, whose ERG light-responses remained constitutively low (day-like). Overall, PER2::Luciferase rhythmicity in whole retinas was not defective in these mice but was characterized by longer period and higher rhythmic power compared to retinas with wild type Bmal1 gene. Taken together, these data suggest that a circadian clock located in rods regulates visual processing in a cell autonomous manner.


Asunto(s)
Relojes Circadianos/fisiología , Adaptación a la Oscuridad/fisiología , Células Fotorreceptoras Retinianas Bastones/metabolismo , Factores de Transcripción ARNTL/genética , Animales , Electrorretinografía , Femenino , Regulación de la Expresión Génica/fisiología , Luciferasas/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Visión Nocturna/fisiología , Proteínas Circadianas Period/metabolismo , Estimulación Luminosa , Reacción en Cadena en Tiempo Real de la Polimerasa , Células Fotorreceptoras Retinianas Bastones/efectos de la radiación , Rodopsina/genética , Sinaptofisina/genética
6.
Extremophiles ; 25(4): 327-342, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-33993356

RESUMEN

Stromatolites are organo-sedimentary structures found principally in seas and saline lakes that contain sheets of sediments and minerals formed by layers of microbial communities, which trap sediments and induce the precipitation of minerals.A living stromatolite from the alkaline Laguna Interna in the Salar de Atacama was collected and one of the fragments was deposited in an experimental aquarium for 18 months. We used Illumina sequencing of PCR-amplified V4 regions of 16S rRNA genes from total extracted DNA to identify the microbial populations. The chemical structure was studied using X-Ray Diffraction (XRD) and bench chemical methods. We found that members belonging to the Proteobacteria, Planctomycetes, Chloroflexi and Bacteroidetes phyla dominated the bacterial communities of the living and aquarium cultured samples. The potential metabolic functionality of the prokaryotic community reveals that sulfur, nitrogen, methane and carbon fixation metabolism functions are present in the samples. This study is the first to provide new insights into the prokaryotic community composition from this unusual aquatic desert site. Further studies will be helpful to obtain a better understanding of the biotic and abiotic mechanisms residing in stromatolites from Laguna Interna, as well as to have better knowledge about the formation of these biosignatures.


Asunto(s)
Biodiversidad , Sedimentos Geológicos , Chile , ADN Bacteriano , Laboratorios , Filogenia , ARN Ribosómico 16S
7.
Eur J Nutr ; 60(8): 4621-4633, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34165614

RESUMEN

OBJECTIVES: Increased availability of high-calorie palatable food in most countries has resulted in overconsumption of these foods, suggesting that excessive eating is driven by pleasure, rather than metabolic need. The behavior contributes to the rise in eating disorders, obesity, and associated pathologies like diabetes, cardiac disease, and cancers. The mesocorticolimbic dopamine and homeostatic circuits are interconnected and play a central role in palatable food intake. The endocannabinoid system is expressed in these circuits and represents a potent regulator of feeding, but the impact of an obesogenic diet on its expression is not fully known. METHODS: Food intake and body weight were recorded in male Wistar rats over a 6-week free-choice regimen of high fat and sugar; transcriptional regulations of the endocannabinoid system were examined post-mortem in brain reward regions (prefrontal cortex, nucleus accumbens, ventral tegmental area, and arcuate nucleus). K-means cluster analysis was used to classify animals based on individual sensitivity to obesity and palatable food intake. Endocannabinoid levels were quantified in the prefrontal cortex and nucleus accumbens. Gene expression in dopamine and homeostatic systems, including ghrelin and leptin receptors, and classical homeostatic peptides, were also investigated. RESULTS: The free-choice high-fat -and sugar diet induced hyperphagia and obesity in rats. Cluster analysis revealed that the propensity to develop obesity and excessive palatable food intake was differently associated with dopamine and endocannabinoid system gene expression in reward and homeostatic brain regions. CB2 receptor mRNA was increased in the nucleus accumbens of high sugar consumers, whereas CB1 receptor mRNA was decreased in obesity prone rats. CONCLUSIONS: Transcriptional data are consistent with observations of altered dopamine function in rodents that have access to an obesogenic diet and point to cannabinoid receptors as GPCR targets involved in neuroplasticity mechanisms associated with maladaptive intake of palatable food.


Asunto(s)
Dieta , Endocannabinoides , Animales , Encéfalo , Análisis por Conglomerados , Ingestión de Alimentos , Masculino , Obesidad/etiología , Ratas , Ratas Wistar , Recompensa
8.
Cell Tissue Res ; 377(1): 81-94, 2019 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-31073908

RESUMEN

Mood state alterations are often accompanied by disruptions of daily rhythms of physiology. Circadian rhythms of physiology are controlled by a central clock harbored in the suprachiasmatic nucleus (SCN), which is functionally dependent on the rhythmic expression of several clock genes. The molecular clockwork has been identified in other extra-SCN brain regions, some of which are implicated in the regulation of motivational and emotional states, although their specific circadian role is not fully known. In mood disorders, alterations of the molecular clock have been reported. Thus, functional expression of circadian genes in the brain is compromised in mood diseases. In the present review, we describe the current evidence that implicates the clock gene alterations as an important factor in the development of mood-related disorders. Furthermore, we describe the possible role of other brain clocks, beyond the SCN, in the circadian control of mood. The comprehension of the circadian neural and genetic mechanisms underlying mood alterations might guide towards the identification of optimal drug and non-drug therapies for the cure of depression and other mood disorders.


Asunto(s)
Relojes Circadianos/genética , Péptidos y Proteínas de Señalización del Ritmo Circadiano/genética , Ritmo Circadiano/genética , Habénula/metabolismo , Trastornos del Humor/genética , Trastornos del Humor/fisiopatología , Animales , Péptidos y Proteínas de Señalización del Ritmo Circadiano/metabolismo , Drosophila melanogaster , Femenino , Humanos , Masculino , Ratones , Ratas , Núcleo Supraquiasmático/metabolismo
9.
Cell Tissue Res ; 377(2): 285-288, 2019 08.
Artículo en Inglés | MEDLINE | ID: mdl-31175443

RESUMEN

The original version of this article was revised: Figures 1 and 2 of the final PDF were not changed according to author's request during the proof corrections.

10.
Int J Cancer ; 143(11): 2777-2786, 2018 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-30171605

RESUMEN

Gastric carcinogenesis proceeds through a series of gastric cancer precursor lesions (GCPLs) leading to gastric cancer (GC) development. Although Helicobacter pylori infection initiates this process, genetic factors also play a role. We previously reported that genetic variability in MUC2 is associated with the evolution of GCPLs. In order to replicate previous results in an independent sample series and to explore whether genetic variability in other candidate genes plays a role in the evolution of GCPL, genomic DNA from 559 patients with GCPLs, recruited from 9 Spanish hospitals and followed for a mean of 12 years, was genotyped for 141 SNPs in 29 genes. After follow-up, 45.5% of the lesions remained stable, 37% regressed and 17.5% progressed to a more severe lesion. Genetic association with the evolution of the lesions (progression or regression) was analyzed by multinomial and binomial logistic regression. After correction for multiple comparisons, the results obtained confirmed the inverse association between MUC2 variants and the regression of the lesions. A significant association was also observed between NFKB1 and CD14 variants and the evolution of the lesions; interestingly, this association was with both progression and regression in the same direction, which could reflect the dual role of inflammation in cancer. Stratified analyses according to H. pylori virulence factors indicated some significant and differential effects but none of them passed the FDR test. These results confirm that genetic variability in MUC2, NFKB1 and CD14 may have a role in the evolution of the GCPLs along time and in gastric carcinogenesis.


Asunto(s)
Predisposición Genética a la Enfermedad/genética , Receptores de Lipopolisacáridos/genética , Mucina 2/genética , Subunidad p50 de NF-kappa B/genética , Polimorfismo de Nucleótido Simple/genética , Lesiones Precancerosas/genética , Neoplasias Gástricas/genética , Adulto , Anciano , Progresión de la Enfermedad , Estudios de Seguimiento , Genotipo , Infecciones por Helicobacter/genética , Helicobacter pylori/patogenicidad , Humanos , Estudios Longitudinales , Persona de Mediana Edad , Lesiones Precancerosas/patología , Neoplasias Gástricas/patología
11.
Rev Esp Enferm Dig ; 110(12): 762-767, 2018 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-30168340

RESUMEN

INTRODUCTION: colon lymphoma (CL) is an uncommon variety of non-Hodgkin lymphoma (NHL) that represents less than 0.6% of all primary colonic neoplasms. Early diagnosis is challenging as clinical manifestations are non-specific. The goal of this review was to discuss our experience over the last few years regarding the clinical, endoscopic, histological, diagnostic, therapeutic and evolutionary characteristics of CL. PATIENTS AND METHODS: a retrospective, descriptive analysis of patients with CL diagnosed from 1994 to 2016 at the Hospital Universitario de La Princesa (Madrid, Spain) was performed. RESULTS: a total of 29 patients with CL were identified, with a median age of 67 years; 18 were male (62%). The most common clinical manifestations included abdominal pain, constitutional syndrome, diarrhea and a palpable abdominal mass. Eight (27.6%) patients were asymptomatic and six (20.6%) initially presented with surgical complications. A colonoscopy was performed in 24 patients and the most common findings included diffuse infiltration and solid growth. The most common location was the descending and sigmoid colon. The most common histological subtypes included mantle B-cell NHL and diffuse large B-cell lymphoma. Chemotherapy was administered to 28 patients (96.5%), surgery was performed in six (20.7%) and combined chemo-radiotherapy was administered to one patient. Median survival was 156 months. Survival was 100.0% at one year and 55.0% at ten years. CONCLUSIONS: due to the variable aspects of CL on endoscopy, a histological study of all colonic segments is required. Chemotherapy is the treatment of choice and emergency surgery followed by chemotherapy is required for complications. Primary factors associated with poorer survival include age above 65 years, relapsing disease and partial or nil responses.


Asunto(s)
Neoplasias del Colon , Linfoma no Hodgkin , Anciano , Anciano de 80 o más Años , Neoplasias del Colon/diagnóstico , Neoplasias del Colon/mortalidad , Neoplasias del Colon/terapia , Femenino , Hospitales Universitarios , Humanos , Linfoma no Hodgkin/diagnóstico , Linfoma no Hodgkin/mortalidad , Linfoma no Hodgkin/terapia , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Tasa de Supervivencia , Factores de Tiempo
12.
Mol Phylogenet Evol ; 110: 73-80, 2017 05.
Artículo en Inglés | MEDLINE | ID: mdl-28288943

RESUMEN

Specialized species, like arboreal folivores, often develop beneficial relationships with symbionts to exploit ecologically constrained lifestyles. Although coevolution can drive speciation by specialization of a symbiont to a host, a symbiotic relationship is not indicative of coevolution between host and symbiont. We tested for coevolved relationships between highly specialized two- and three-toed sloths (Choloepus spp. and Bradypus spp., respectively) and their symbiotic algae using cophylogenies and phylogeography. Our phylogeographic analysis showed a biogeographic pattern for the sloth distribution that was not found in the algal phylogeny. We found support for congruence between the sloth and algae phylogenies, implying cospeciation, only in the Bradypus lineage. Algae host-switching occurred from Bradypus spp. to Choloepus spp. Our results support a previously hypothesized symbiotic relationship between sloths and the algae in their fur and indicate that coevolution may have played a role in algae diversification. More broadly, convergent evolution may facilitate host switching between deeply diverged host lineages.


Asunto(s)
Eucariontes/fisiología , Filogenia , Filogeografía , Perezosos/clasificación , Simbiosis/fisiología , Animales , Especificidad de la Especie
13.
FASEB J ; 30(11): 3690-3701, 2016 11.
Artículo en Inglés | MEDLINE | ID: mdl-27440795

RESUMEN

The circadian clock is thought to adjust retinal sensitivity to ambient light levels, yet the involvement of specific clock genes is poorly understood. We explored the potential role of the nuclear receptor subfamily 1, group D, member 1 (REV-ERBα; or NR1D1) in this respect. In light-evoked behavioral tests, compared with wild-type littermates, Rev-Erbα-/- mice showed enhanced negative masking at low light levels (0.1 lx). Rev-Erbα-/- mouse retinas displayed significantly higher numbers of intrinsically photosensitive retinal ganglion cells (ipRGCs; 62% more compared with wild-type) and more intense melanopsin immunostaining of individual ipRGCs. In agreement with a pivotal role for melanopsin, negative masking at low light intensities was abolished in Rev-Erbα-/- Opn4-/- (melanopsin gene) double-null mice. Rev-Erbα-/- mice showed shortened latencies of both a and b electroretinogram waves, modified scotopic and photopic b-wave and scotopic threshold responses, and increased pupillary constriction, all of which suggested increased light sensitivity. However, wild-type and Rev-Erbα-/- mice displayed no detectable differences by in vivo fundus imaging, retinal histology, or expression of cell type-specific markers for major retinal cell populations. We conclude that REV-ERBα plays a major role in retinal information processing, and we speculate that REV-ERBα and melanopsin set sensitivity levels of the rod-mediated ipRGC pathway to coordinate activity with ambient light.-Ait-Hmyed Hakkari, O., Acar, N., Savier, E., Spinnhirny, P., Bennis, M., Felder-Schmittbuhl, M.-P., Mendoza, J., Hicks, D. Rev-Erbα modulates retinal visual processing and behavioral responses to light.


Asunto(s)
Conducta Animal/fisiología , Luz , Miembro 1 del Grupo D de la Subfamilia 1 de Receptores Nucleares/metabolismo , Retina/fisiología , Opsinas de Bastones/metabolismo , Animales , Relojes Circadianos/genética , Relojes Circadianos/fisiología , Ritmo Circadiano/fisiología , Ratones Noqueados , Miembro 1 del Grupo D de la Subfamilia 1 de Receptores Nucleares/deficiencia , Estimulación Luminosa/métodos , Células Ganglionares de la Retina/fisiología , Opsinas de Bastones/genética
14.
Addict Biol ; 22(2): 411-422, 2017 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26632340

RESUMEN

The drive to eat is regulated by two compensatory brain pathways termed as homeostatic and hedonic. Hypothalamic orexinergic (ORX) neurons regulate metabolism, feeding and reward, thus controlling physiological and hedonic appetite. Circadian regulation of feeding, metabolism and rhythmic activity of ORX cells are driven by the brain suprachiasmatic clock. How the circadian clock impacts on ORX signalling and feeding-reward rhythms is, however, unknown. Here we used mice lacking the nuclear receptor REV-ERBα, a transcription repressor and a key component of the molecular clockwork, to study food-reward behaviour. Rev-Erbα mutant mice showed highly motivated behaviours to obtain palatable food, an increase in the intake and preference for tasty diets, and in the expression of the ORX protein in the hypothalamus. Palatable food intake was inhibited in animals treated with the ORX1R antagonist. Analyzing the Orx promoter, we found Retinoic acid-related Orphan receptor Response Element binding sites for Rev-Erbα. Furthermore, Rev-Erbα dampened the activation of Orx in vitro and in vivo. Our data provide evidence for a possible repressive role of Rev-Erbα in the regulation of ORX signalling, highlighting an implication of the circadian clockwork in modulating food-reward behaviours with an important impact for the central regulation of overeating.


Asunto(s)
Ingestión de Alimentos/genética , Conducta Alimentaria/fisiología , Hipotálamo/metabolismo , Neuronas/metabolismo , Miembro 1 del Grupo D de la Subfamilia 1 de Receptores Nucleares/genética , Orexinas/metabolismo , Animales , Ritmo Circadiano , Ingestión de Alimentos/efectos de los fármacos , Conducta Alimentaria/efectos de los fármacos , Masculino , Ratones , Ratones Noqueados , Antagonistas de los Receptores de Orexina/farmacología , Receptores de Orexina/metabolismo , Regiones Promotoras Genéticas , Transducción de Señal
15.
Appetite ; 117: 263-269, 2017 10 01.
Artículo en Inglés | MEDLINE | ID: mdl-28687372

RESUMEN

The suprachiasmatic nucleus (SCN) times the daily rhythms of behavioral processes including feeding. Beyond the SCN, the hypothalamic arcuate nucleus (ARC), involved in feeding regulation and metabolism, and the epithalamic lateral habenula (LHb), implicated in reward processing, show circadian rhythmic activity. These brain oscillators are functionally coupled to coordinate the daily rhythm of food intake. In rats, a free choice high-fat high-sugar (fcHFHS) diet leads to a rapid increase of calorie intake and body weight gain. Interestingly, under a fcHFHS condition, rats ingest a similar amount of sugar during day time (rest phase) as during night time (active phase), but keep the rhythmic intake of regular chow-food. The out of phase between feeding patterns of regular (chow) and highly rewarding food (sugar) may involve alterations of brain circadian oscillators regulating feeding. Here, we report that the fcHFHS diet is a successful model to induce calorie intake, body weight gain and fat tissue accumulation in mice, extending its effectiveness as previously reported in rats. Moreover, we observed that whereas in the SCN the day-night difference in the PER2 clock protein expression was similar between chow-fed and fcHFHS-fed animals, in the LHb, this day-night difference was altered in fcHFHS-exposed animals compared to control chow mice. These findings confirm previous observations in rats showing disrupted daily patterns of feeding behavior under a fcHFHS diet exposure, and extend our insights on the effects of the diet on circadian gene expression in brain clocks.


Asunto(s)
Factores de Transcripción ARNTL/metabolismo , Dieta Occidental/efectos adversos , Conducta Alimentaria , Preferencias Alimentarias , Regulación de la Expresión Génica , Habénula/metabolismo , Proteínas Circadianas Period/metabolismo , Factores de Transcripción ARNTL/genética , Adiposidad , Animales , Conducta Animal , Conducta de Elección , Ritmo Circadiano , Habénula/patología , Masculino , Ratones Endogámicos C57BL , Ratones Mutantes , Proteínas del Tejido Nervioso/genética , Proteínas del Tejido Nervioso/metabolismo , Neuronas/metabolismo , Neuronas/patología , Obesidad/etiología , Obesidad/metabolismo , Obesidad/patología , Especificidad de Órganos , Proteínas Circadianas Period/genética , Distribución Aleatoria , Núcleo Supraquiasmático/metabolismo , Núcleo Supraquiasmático/patología , Aumento de Peso
16.
Multivariate Behav Res ; 52(2): 164-177, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-27997223

RESUMEN

A common form of missing data is caused by selection on an observed variable (e.g., Z). If the selection variable was measured and is available, the data are regarded as missing at random (MAR). Selection biases correlation, reliability, and effect size estimates when these estimates are computed on listwise deleted (LD) data sets. On the other hand, maximum likelihood (ML) estimates are generally unbiased and outperform LD in most situations, at least when the data are MAR. The exception is when we estimate the partial correlation. In this situation, LD estimates are unbiased when the cause of missingness is partialled out. In other words, there is no advantage of ML estimates over LD estimates in this situation. We demonstrate that under a MAR condition, even ML estimates may become biased, depending on how partial correlations are computed. Finally, we conclude with recommendations about how future researchers might estimate partial correlations even when the cause of missingness is unknown and, perhaps, unknowable.


Asunto(s)
Interpretación Estadística de Datos , Funciones de Verosimilitud , Análisis Multivariante , Algoritmos , Simulación por Computador , Escolaridad , Humanos , Método de Montecarlo , Reproducibilidad de los Resultados , Factores Socioeconómicos , Estudiantes , Universidades
17.
J Gastroenterol Hepatol ; 31(5): 953-8, 2016 May.
Artículo en Inglés | MEDLINE | ID: mdl-26630310

RESUMEN

BACKGROUND AND AIM: In high or moderate risk populations, periodic surveillance of patients at risk of progression from gastric precursor lesions (PL) to gastric cancer (GC) is the most effective strategy for reducing the burden of GC. Incomplete type of intestinal metaplasia (IIM) may be considered as the best candidate, but it is still controversial and more research is needed. To further assess the progression of subtypes of IM as predictors of GC occurrence. METHODS: A follow-up study was carried-out including 649 patients, diagnosed with PL between 1995-2004 in 9 participating hospitals from Spain, and who repeated the biopsy during 2011-2013. Medical information and habits were collected through a questionnaire. Based on morphology, IM was sub-classified as complete (small intestinal type, CIM) and incomplete (colonic type, IIM). Analyses were done using Cox (HR) models. RESULTS: At baseline, 24% of patients had atrophic gastritis, 38% CIM, 34% IIM, and 4% dysplasia. Mean follow-up was 12 years. 24 patients (3.7%) developed a gastric adenocarcinoma during follow-up. The incidence rate of GC was 2.76 and 5.76 per 1,000 person-years for those with CIM and IIM, respectively. The HR of progression to CG was 2.75 (95% CI 1.06-6.26) for those with IIM compared with those with CIM at baseline, after adjusting for sex, age, smoking, family history of GC and use of NSAIDs. CONCLUSIONS: IIM is the PL with highest risk to progress to GC. Sub-typing of IM is a valid procedure for the identification of high risk patients that require more intensive surveillance.


Asunto(s)
Adenocarcinoma/patología , Transformación Celular Neoplásica/patología , Gastritis Atrófica/patología , Lesiones Precancerosas/patología , Neoplasias Gástricas/patología , Estómago/patología , Adenocarcinoma/epidemiología , Adulto , Biopsia , Progresión de la Enfermedad , Femenino , Estudios de Seguimiento , Gastritis Atrófica/epidemiología , Humanos , Estudios Longitudinales , Masculino , Metaplasia , Persona de Mediana Edad , Análisis Multivariante , Lesiones Precancerosas/epidemiología , Modelos de Riesgos Proporcionales , Medición de Riesgo , Factores de Riesgo , España/epidemiología , Neoplasias Gástricas/epidemiología , Encuestas y Cuestionarios , Factores de Tiempo
18.
Conserv Biol ; 29(5): 1257-67, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-25855043

RESUMEN

Conservation biologists are generally united in efforts to curtail the spread of non-native species globally. However, the colonization history of a species is not always certain, and whether a species is considered non-native or native depends on the conservation benchmark. Such ambiguities have led to inconsistent management. Within the Tongass National Forest of Alaska, the status of American marten (Martes americana) on the largest, most biologically diverse and deforested island, Prince of Wales (POW), is unclear. Ten martens were released to POW in the early 1930s, and it was generally believed to be the founding event, although this has been questioned. The uncertainty surrounding when and how martens colonized POW complicates management, especially because martens were selected as a design species for the Tongass. To explore the history of martens of POW we reviewed other plausible routes of colonization; genetically and isotopically analyzed putative marten fossils deposited in the late Pleistocene and early Holocene to verify marten occupancy of POW; and used contemporary genetic data from martens on POW and the mainland in coalescent simulations to identify the probable source of the present-day marten population on POW. We found evidence for multiple routes of colonization by forest-associated mammals beginning in the Holocene, which were likely used by American martens to naturally colonize POW. Although we cannot rule out human-assisted movement of martens by Alaskan Natives or fur trappers, we suggest that martens be managed for persistence on POW. More generally, our findings illustrate the difficulty of labeling species as non-native or native, even when genetic and paleo-ecological data are available, and support the notion that community resilience or species invasiveness should be prioritized when making management decisions rather than more subjective and less certain conservation benchmarks.


Asunto(s)
Conservación de los Recursos Naturales , Mustelidae/fisiología , Alaska , Distribución Animal , Animales , Fósiles , Islas , Mustelidae/crecimiento & desarrollo , Alineación de Secuencia , Análisis de Secuencia de ADN
19.
Proc Biol Sci ; 281(1778): 20133006, 2014 Mar 07.
Artículo en Inglés | MEDLINE | ID: mdl-24452028

RESUMEN

Arboreal herbivory is rare among mammals. The few species with this lifestyle possess unique adaptions to overcome size-related constraints on nutritional energetics. Sloths are folivores that spend most of their time resting or eating in the forest canopy. A three-toed sloth will, however, descend its tree weekly to defecate, which is risky, energetically costly and, until now, inexplicable. We hypothesized that this behaviour sustains an ecosystem in the fur of sloths, which confers cryptic nutritional benefits to sloths. We found that the more specialized three-toed sloths harboured more phoretic moths, greater concentrations of inorganic nitrogen and higher algal biomass than the generalist two-toed sloths. Moth density was positively related to inorganic nitrogen concentration and algal biomass in the fur. We discovered that sloths consumed algae from their fur, which was highly digestible and lipid-rich. By descending a tree to defecate, sloths transport moths to their oviposition sites in sloth dung, which facilitates moth colonization of sloth fur. Moths are portals for nutrients, increasing nitrogen levels in sloth fur, which fuels algal growth. Sloths consume these algae-gardens, presumably to augment their limited diet. These linked mutualisms between moths, sloths and algae appear to aid the sloth in overcoming a highly constrained lifestyle.


Asunto(s)
Conducta Animal , Mariposas Nocturnas/fisiología , Perezosos/fisiología , Simbiosis , Fenómenos Fisiológicos Nutricionales de los Animales , Animales , Biomasa , Chlorophyta/metabolismo , Chlorophyta/fisiología , Defecación , Ecosistema , Conducta Alimentaria , Herbivoria , Nitrógeno/análisis , Oviposición
20.
Multivariate Behav Res ; 49(6): 597-613, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-26735360

RESUMEN

Much research has been directed at the validity of fit indices in Path Analysis and Structural Equation Modeling (e.g., Browne, MacCallum, Kim, Andersen, & Glaser, 2002 ; Heene, Hilbert, Draxler, Ziegler, & Bühner, 2011 ; Hu & Bentler, 1999 ; Marsh, Hau, & Wen, 2004 ). Recent developments (e.g., Preacher, 2006 ; Roberts & Pashler, 2000 , 2002 ) have encouraged researchers to investigate other criteria for comparing models, including model complexity. What has not been investigated is the inherent ability of a particular data set to be fitted with a constrained set of randomly generated linear models, which we call Model Conditioned Data Elasticity (DE). In this article we show how DE can be compared with the problem of equivalent models and a more general problem of the "confoundability" of data/model combinations (see MacCallum, Wegener, Uchino, & Fabrigar, 1993 ). Using the DE package in R, we show how DE can be assessed through automated computer searches. Finally, we discuss how DE fits within the controversy surrounding the use of fit statistics.

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