Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 613
Filtrar
1.
Proc Biol Sci ; 287(1927): 20192779, 2020 05 27.
Artículo en Inglés | MEDLINE | ID: mdl-32429814

RESUMEN

Understanding how information about threats in the environment is shared and transmitted between individuals is crucial for explaining adaptive, survival-related behaviour in humans and other animals, and for developing treatments for phobias and other anxiety disorders. Research across species has shown that observing a conspecific's, a 'demonstrator's,' threat responses causes strong and persistent threat memories in the 'observer'. Here, we examined if physiological synchrony between demonstrator and observer can serve to predict the strength of observationally acquired conditioned responses. We measured synchrony between demonstrators' and observers' phasic electrodermal signals during learning, which directly reflects autonomic nervous system activity. Prior interpersonal synchrony predicted the strength of the observer's later skin conductance responses to threat predicting stimuli, in the absence of the demonstrator. Dynamic coupling between an observer's and a demonstrator's autonomic nervous system activity may reflect experience sharing processes facilitating the formation of observational threat associations.


Asunto(s)
Condicionamiento Clásico , Aprendizaje , Fenómenos Fisiológicos , Humanos , Conducta Imitativa
2.
Pestic Biochem Physiol ; 164: 85-90, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-32284141

RESUMEN

Pyridalyl is one of the recently discovered insecticides which has shown toxicity against several insect pests with slight- or non-lethal effects against natural enemies. Cytotoxicity and prevention of protein synthesis have been reported as pyridalyl mode of action. In the current study, adults of Bacterocera oleae, as a major pest of olive, were fed on protein hydrolysate diet containing LC50 concentration of pyridalyl to determine the possible mode of action through gene expression and amino acid profile. Results showed that treated flies had significantly higher gene expressions of cytochrome P450, insulin receptor-like, antioxidant enzymes (catalase, peroxidase, superoxide dismutase) and the enzymes involved in cell death; caspase1, caspase3, caspase8 and caspase9 compared to control. Moreover, determination of amino acid profile in the whole body of both control and pyridalyl-treated B. oleae revealed the significant higher amounts of glutamic acid, glutamine, histidine, threonine, citrulin, arginine, taurine, alanine, tyrosine, α-amino butric acid, methionine and isoleucine in the treated adults while the control flies had the higher amounts of serine, glycine and tryptophane. No significant differences were found in the amounts of asparagine and phenylalanine between control and treatments. These results are in accordance with earlier findings on mode of action of pyridalyl through activation of cytochrome P450 system and alterations in protein synthesis machinery although here other mechanisms were also reported including activation of insulin receptor and antioxidant enzymes. Moreover, it is the first report on cytotoxicity through apoptosis with engagement of caspases.


Asunto(s)
Insecticidas , Fenómenos Fisiológicos , Tephritidae , Animales , Éteres Fenílicos
3.
Annu Rev Pathol ; 15: 371-394, 2020 01 24.
Artículo en Inglés | MEDLINE | ID: mdl-31977295

RESUMEN

Modeling has enabled fundamental advances in our understanding of the mechanisms of health and disease for centuries, since at least the time of William Harvey almost 500 years ago. Recent technological advances in molecular methods, computation, and imaging generate optimism that mathematical modeling will enable the biomedical research community to accelerate its efforts in unraveling the molecular, cellular, tissue-, and organ-level processes that maintain health, predispose to disease, and determine response to treatment. In this review, we discuss some of the roles of mathematical modeling in the study of human physiology and pathophysiology and some challenges and opportunities in general and in two specific areas: in vivo modeling of pulmonary function and in vitro modeling of blood cell populations.


Asunto(s)
Investigación Biomédica/métodos , Biología Computacional/métodos , Enfermedad/etiología , Modelos Teóricos , Animales , Investigación Biomédica/tendencias , Biología Celular/tendencias , Biología Computacional/tendencias , Simulación por Computador , Humanos , Fenómenos Fisiológicos
4.
Nat Biomed Eng ; 4(2): 148-158, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-31768002

RESUMEN

Skin-mounted soft electronics that incorporate high-bandwidth triaxial accelerometers can capture broad classes of physiologically relevant information, including mechano-acoustic signatures of underlying body processes (such as those measured by a stethoscope) and precision kinematics of core-body motions. Here, we describe a wireless device designed to be conformally placed on the suprasternal notch for the continuous measurement of mechano-acoustic signals, from subtle vibrations of the skin at accelerations of around 10-3 m s-2 to large motions of the entire body at about 10 m s-2, and at frequencies up to around 800 Hz. Because the measurements are a complex superposition of signals that arise from locomotion, body orientation, swallowing, respiration, cardiac activity, vocal-fold vibrations and other sources, we exploited frequency-domain analysis and machine learning to obtain-from human subjects during natural daily activities and exercise-real-time recordings of heart rate, respiration rate, energy intensity and other essential vital signs, as well as talking time and cadence, swallow counts and patterns, and other unconventional biomarkers. We also used the device in sleep laboratories and validated the measurements using polysomnography.


Asunto(s)
Técnicas Biosensibles/instrumentación , Técnicas Biosensibles/métodos , Monitoreo Fisiológico/instrumentación , Monitoreo Fisiológico/métodos , Fenómenos Fisiológicos , Tecnología Inalámbrica/instrumentación , Clavícula , Diseño de Equipo , Ejercicio Físico/fisiología , Humanos , Procesamiento de Señales Asistido por Computador , Fenómenos Fisiológicos de la Piel , Sueño/fisiología , Vibración
5.
Sci Total Environ ; 711: 135117, 2020 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-31831233

RESUMEN

Exposure to methylmercury (MeHg) can result in detrimental health effects in wildlife. With advances in ecological indicators and analytical techniques for measurement of MeHg in a variety of tissues, numerous processes have been identified that can influence MeHg concentrations in wildlife. This review presents a synthesis of theoretical principals and applied information for measuring MeHg exposure and interpreting MeHg concentrations in wildlife. Mercury concentrations in wildlife are the net result of ecological processes influencing dietary exposure combined with physiological processes that regulate assimilation, transformation, and elimination. Therefore, consideration of both physiological and ecological processes should be integrated when formulating biomonitoring strategies. Ecological indicators, particularly stable isotopes of carbon, nitrogen, and sulfur, compound-specific stable isotopes, and fatty acids, can be effective tools to evaluate dietary MeHg exposure. Animal species differ in their physiological capacity for MeHg elimination, and animal tissues can be inert or physiologically active, act as sites of storage, transformation, or excretion of MeHg, and vary in the timing of MeHg exposure they represent. Biological influences such as age, sex, maternal transfer, and growth or fasting are also relevant for interpretation of tissue MeHg concentrations. Wildlife tissues that represent current or near-term bioaccumulation and in which MeHg is the predominant mercury species (such as blood and eggs) are most effective for biomonitoring ecosystems and understanding landscape drivers of MeHg exposure. Further research is suggested to critically evaluate the use of keratinized external tissues to measure MeHg bioaccumulation, particularly for less-well studied wildlife such as reptiles and terrestrial mammals. Suggested methods are provided to effectively use wildlife for quantifying patterns and drivers of MeHg bioaccumulation over time and space, as well as for assessing the potential risk and toxicological effects of MeHg on wildlife.


Asunto(s)
Ecosistema , Fenómenos Fisiológicos , Animales , Mercurio , Compuestos de Metilmercurio
6.
Int J Mol Sci ; 20(24)2019 Dec 11.
Artículo en Inglés | MEDLINE | ID: mdl-31835844

RESUMEN

p53, first described four decades ago, is now established as a master regulator of cellular stress response, the "guardian of the genome". p53 contributes to biological robustness by behaving in a cellular-context dependent manner, influenced by several factors (e.g., cell type, active signalling pathways, the type, extent and intensity of cellular damage, cell cycle stage, nutrient availability, immune function). The p53 isoforms regulate gene transcription and protein expression in response to the stimuli so that the cell response is precisely tuned to the cell signals and cell context. Twelve isoforms of p53 have been described in humans. In this review, we explore the interactions between p53 isoforms and other proteins contributing to their established cellular functions, which can be both tumour-suppressive and oncogenic in nature. Evidence of p53 isoform in human cancers is largely based on RT-qPCR expression studies, usually investigating a particular type of isoform. Beyond p53 isoform functions in cancer, it is implicated in neurodegeneration, embryological development, progeroid phenotype, inflammatory pathology, infections and tissue regeneration, which are described in this review.


Asunto(s)
Neoplasias/metabolismo , Fenómenos Fisiológicos , Proteína p53 Supresora de Tumor/metabolismo , Animales , Secuencia Conservada , Humanos , Mutación/genética , Neoplasias/patología , Isoformas de Proteínas/química , Isoformas de Proteínas/metabolismo , Proteína p53 Supresora de Tumor/química , Proteína p53 Supresora de Tumor/genética
7.
Elife ; 82019 12 03.
Artículo en Inglés | MEDLINE | ID: mdl-31793432

RESUMEN

The microbialization of coral reefs predicts that microbial oxygen consumption will cause reef deoxygenation. Here we tested this hypothesis by analyzing reef microbial and primary producer oxygen metabolisms. Metagenomic data and in vitro incubations of bacteria with primary producer exudates showed that fleshy algae stimulate incomplete carbon oxidation metabolisms in heterotrophic bacteria. These metabolisms lead to increased cell sizes and abundances, resulting in bacteria consuming 10 times more oxygen than in coral incubations. Experiments probing the dissolved and gaseous oxygen with primary producers and bacteria together indicated the loss of oxygen through ebullition caused by heterogenous nucleation on algae surfaces. A model incorporating experimental production and loss rates predicted that microbes and ebullition can cause the loss of up to 67% of gross benthic oxygen production. This study indicates that microbial respiration and ebullition are increasingly relevant to reef deoxygenation as reefs become dominated by fleshy algae.


Asunto(s)
Antozoos/fisiología , Biofisica , Oxígeno/metabolismo , Fenómenos Fisiológicos/fisiología , Animales , Bacterias/metabolismo , Biomasa , Carbono/metabolismo , Arrecifes de Coral , Ecosistema , Procesos Heterotróficos , Metagenoma , Microalgas/metabolismo , Agua de Mar/microbiología , Microbiología del Agua
8.
Biofouling ; 35(8): 832-839, 2019 09.
Artículo en Inglés | MEDLINE | ID: mdl-31570009

RESUMEN

The attachment efficiency of biofouling organisms on solid surfaces depends on a variety of factors, including fouler species, nutrition abundance, flow rate, surface morphology and the stiffness of the solid to which attachment is to be made. So far, extensive research has been carried out to investigate the effects of these factors on the attachment of various fouling species. However, the results obtained are species-dependent and scattered. There is no universal rule that can be applied to predict the attachment efficiency of different species. To solve this problem, the authors carried out meta-analysis of the effects of ten selected factors on attachment efficiency, resulting in a universal correlation between the attachment density and the selected factors, which was validated by attachment tests of tubeworms on PDMS surfaces. The results provide a practical approach to predicting the attachment efficiency of fouling organisms and should be of great value in the design of anti-biofouling materials.


Asunto(s)
Organismos Acuáticos/fisiología , Incrustaciones Biológicas , Dimetilpolisiloxanos/química , Modelos Biológicos , Poliquetos/fisiología , Propiedades de Superficie , Animales , Fenómenos Fisiológicos
10.
Int J Qual Stud Health Well-being ; 14(1): 1647401, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31432771

RESUMEN

Purpose: Exploring real-life experiences of Chronic Obstructive Pulmonary Disease (COPD) patients during rehabilitation can contribute with new knowledge of what has significance for their participation and chance for improved health and well-being. Therefore, this study aims to gain in-depth knowledge of COPD patients' lived experiences while following standard pulmonary out-patient rehabilitation. Methods: Combined participant observations and interviews were conducted among 21 participants in pulmonary rehabilitation. A three-leveled phenomenological-hermeneutic interpretation was applied. Results: Living with COPD was challenging due to dyspnea and other physical troubles. This caused a lack of trust in the body and complicated rehabilitation participation. When improving management of breath during rehabilitation, the patients gained a new sense of trust in the body. This was accompanied by a nascent hope and increased well-being. However, not succeeding in this left patients with a persistent lack of hope. Conclusions: Comprehensive troubles in living with COPD paradoxically prevents patients' prospect of overcoming a perceived lack of trust in their body during standard pulmonary rehabilitation. Enhancing breath management has a significant impact on COPD patients' trust in own capabilities to improve well-being and health. Future rehabilitation must accommodate COPD patients' troubles by longer-lasting, well-coordinated, individually supportive and more easily accessible programmes.


Asunto(s)
Adaptación Psicológica , Pacientes/psicología , Fenómenos Fisiológicos/fisiología , Enfermedad Pulmonar Obstructiva Crónica/psicología , Enfermedad Pulmonar Obstructiva Crónica/rehabilitación , Calidad de Vida/psicología , Anciano , Anciano de 80 o más Años , Femenino , Hermenéutica , Humanos , Masculino , Persona de Mediana Edad , Investigación Cualitativa
12.
Aquat Toxicol ; 212: 20-27, 2019 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-31039523

RESUMEN

Polybrominated diphenyl ethers (PBDEs), a series of highly persistent organic pollutants (POPs), are ubiquitous in marine ecosystems. As key primary producers, microalgae are of great importance on evaluating the environmental outcome of PBDEs pollution. In this study, the toxic mechanisms of BDE-47 on the marine diatom Thalassiosira pseudonana were evaluated by measuring multiple physiological processes. Three concentrations of BDE-47 (25, 15 and 5 µg L-1) were used along with two controls (blank: no BDE-47 or DMSO; negative control: only DMSO). Experiments lasted 144 h (6 days), in which the actual BDE-47 concentrations, cell densities, nutrient (nitrate and phosphate) uptake, pigment compositions, photosynthetic physiology, cell morphology and cellular contents (organic carbon and nitrogen) were measured at 12-48 h intervals. The toxic mechanisms of BDE-47 on T. pseudonana cells were evaluated by measuring multiple physiological processes including photosynthesis, nutrient uptake, cellular material synthesis and cell cycle progressions. The cell divisions of T. pseudonana were severely inhibited by the stress of BDE-47, but the photosynthetic parameters were much less declined and recovered earlier than the cell divisions in the same BDE-47 treatments. The unsuppressed uptake rates of nutrients, increased cell volume and cellular contents indicated the cellular material synthesis proceeded normally. Finally, we found that the cell cycle was arrested in G2/M phase under the stress of BDE-47, we thus concluded that the inhibition of cell divisions by BDE-47 was not due to the lack of energy or cellular materials, where the cell cycle arrest happened; this might be the most important toxicological outcome.


Asunto(s)
Diatomeas/efectos de los fármacos , Diatomeas/fisiología , Éteres Difenilos Halogenados/toxicidad , Fenómenos Fisiológicos/efectos de los fármacos , Contaminantes Químicos del Agua/toxicidad , Carbono/metabolismo , Ciclo Celular/efectos de los fármacos , Diatomeas/citología , Diatomeas/crecimiento & desarrollo , Nitrógeno/metabolismo , Fotosíntesis/efectos de los fármacos , Complejo de Proteína del Fotosistema II/metabolismo , Pigmentos Biológicos/metabolismo , Estrés Fisiológico/efectos de los fármacos
13.
Appl Ergon ; 78: 37-53, 2019 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-31046958

RESUMEN

This scoping review examines the effects of sit-stand desks (SSDs) on six domains: behavior (e.g. time sitting and standing), physiological, work performance, psychological, discomfort, and posture. Fifty-three articles met criteria. We determined the percentage of significant results for each domain. Forty-seven studies were experimental trials. Sample sizes ranged from six to 231 participants. Follow-up time-frames ranged from one day to one year. Sixty-one percent of behavioral (24 studies), 37% of physiological (28 studies), 7% of work performance (23 studies), 31% of psychological (11 studies), 43% of discomfort (22 studies), and 18% of posture domain results (4 studies) were significant. We conclude that SSDs effectively change behaviors, but these changes only mildly effect health outcomes. SSDs seem most effective for discomfort and least for productivity. Further study is needed to examine long-term effects, and to determine clinically appropriate dosage and workstation setup.


Asunto(s)
Estado de Salud , Diseño Interior y Mobiliario , Lugar de Trabajo , Conducta , Humanos , Movimiento , Dolor Musculoesquelético/prevención & control , Fenómenos Fisiológicos , Sedestación , Posición de Pie , Rendimiento Laboral
14.
Biomed Eng Online ; 18(1): 30, 2019 Mar 20.
Artículo en Inglés | MEDLINE | ID: mdl-30894180

RESUMEN

BACKGROUND: Entropy analysis has been attracting increasing attentions in the recent two or three decades. It assesses complexity, or irregularity, of time-series which is extraordinarily relevant to physiology and diseases as demonstrated by tremendous studies. However, the complexity can hardly be appreciated by traditional methods including time-, frequency-domain analysis, and time-frequency analysis that are the common built-in options in commercialized measurement and statistical software. To facilitate the entropy analysis of physiological time-series, a new software application, namely EZ Entropy, was developed and introduced in this article. RESULTS: EZ Entropy was developed in MATLAB® environment. It was programmed in an object-oriented style and was constructed with a graphical user interface. EZ Entropy is easy to operate through its compact graphical interface, thus allowing researchers without knowledge of programming like clinicians and physiologists to perform such kind of analysis. Besides, it offers various settings to meet different analysis needs including (1) processing single data recording, (2) batch processing multiple data files, (3) sliding window calculations, (4) recall, (5) displaying intermediate data and final results, (6) adjusting input parameters, and (7) exporting calculation results after the run or in real-time during the analysis. The analysis results could be exported, either manually or automatically, to comma-separated ASCII files, thus being compatible to and easily imported into the common statistical analysis software. Code-wise, EZ Entropy is object-oriented, thus being quite easy to maintain and extend. CONCLUSIONS: EZ Entropy is a user-friendly software application to perform the entropy analysis of time-series, as well as to simplify and to speed up this useful analysis.


Asunto(s)
Entropía , Fenómenos Fisiológicos , Programas Informáticos , Algoritmos , Interfaz Usuario-Computador
15.
Int J Nanomedicine ; 14: 1563-1573, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30880965

RESUMEN

Purpose: Undesirable complement (C) activation by nanomedicines can entail an adverse immune reaction known as C activation-related pseudoallergy (CARPA) in sensitive patients. The syndrome includes cardiopulmonary, hemodynamic, and a variety of other physiological changes that have been well described in man, pigs, dogs, and rats. However, the information on CARPA is scarce and ambiguous in mice, a species widely used in preclinical studies. The present study aimed to fill this gap by exploring signs of CARPA in mice following i.v. administration of AmBisome and Abelcet, which are nano-formulations of Amphotericin B with high risk to cause CARPA. Materials and methods: Anesthetized NMRI mice were intravenously injected with liposomal amphotericin B (Abelcet and AmBisome; 30-300 mg phospholipid/kg), drug-free high cholesterol multilamellar vesicles (HC-MLV), and positive controls, cobra venom factor (CVF) and zymosan, followed by the measurement of blood pressure (BP), heart rate, white blood cell, and platelet counts and plasma thromboxane B2 (TXB2) levels. C activation was assessed by C3a ELISA, a C3 consumption assay (PAN-C3) and a modified sheep red blood cell hemolytic assay. Results: All test agents, except HC-MLV, caused transient hypertension, thrombocytopenia, and elevation of plasma TXB2, which were paralleled by significant rises of plasma C3a in CVF and zymosan-treated animals, wherein the initial hypertension turned into hypotension and shock. Abelcet and AmBisome caused minor, delayed rise of C3a that was not associated with hypertension. The C3a receptor inhibitor SB-290157 attenuated the hypertension caused by Abelcet and decreased the BP thereafter. Conclusion: The parallelism between C3a anaphylatoxin production and severity of physiological changes caused by the different agents is consistent with CARPA underlying these changes. Although the reactive dose of liposomal phospholipids was substantially higher than that in other species (pigs, dogs), the mouse seems suitable for studying the mechanism of hypersensitivity reactions to liposomal formulations of amphotericin B, a frequent side effect of these drugs.


Asunto(s)
Anfotericina B/farmacología , Activación de Complemento/efectos de los fármacos , Fenómenos Fisiológicos/efectos de los fármacos , Animales , Presión Sanguínea/efectos de los fármacos , Frecuencia Cardíaca/efectos de los fármacos , Hemodinámica/efectos de los fármacos , Hipertensión/fisiopatología , Inmunidad Innata/efectos de los fármacos , Liposomas , Masculino , Ratones Endogámicos C57BL , Receptores de Complemento/antagonistas & inhibidores , Receptores de Complemento/metabolismo
16.
PLoS One ; 14(2): e0211722, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30707747

RESUMEN

The influence of physical oceanographic processes on the dispersal of larvae is critical for understanding the ecology of species and for anticipating settlement into fisheries to aid long-term sustainable harvest. This study examines the mechanisms by which ocean currents shape larval dispersal and supply to the continental shelf-break, and the extent to which circulation determines settlement patterns using Sagmariasus verreauxi (Eastern Rock Lobster, ERL) as a model species. Despite the large range of factors that can impact larval dispersal, we show that within a Western Boundary Current system, mesoscale circulation explains broad spatio-temporal patterns of observed settlement including inter-annual and decadal variability along 500 km of coastline. To discern links between ocean circulation and settlement, we correlate a unique 21- year dataset of observed lobster settlement (i.e., early juvenile & pueruli abundance), with simulated larval settlement. Simulations use outputs of an eddy-resolving, data-assimilated, hydrodynamic model, incorporating ERL spawning strategy and larval duration. The latitude where the East Australian Current (EAC) deflects east and separates from the continent determines the limit between regions of low and high ERL settlement. We found that years with a persistent EAC flow have low settlement while years when mesoscale eddies prevail have high settlement; in fact, mesoscale eddies facilitate the transport of larvae to the continental shelf-break from offshore. Proxies for settlement based on circulation features observed with satellites could therefore be useful in predicting broadscale patterns of settlement orders of magnitudes to guide harvest limits.


Asunto(s)
Distribución Animal/fisiología , Palinuridae/metabolismo , Animales , Australia , Simulación por Computador , Conservación de los Recursos Naturales/métodos , Explotaciones Pesqueras , Hidrodinámica , Larva , Oceanografía , Fenómenos Fisiológicos , Alimentos Marinos , Análisis Espacio-Temporal
17.
Urol Int ; 102(4): 487-491, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30731473

RESUMEN

BACKGROUND: Postmicturition dribble (PMD) is a common condition in the male population. OBJECTIVES: Despite its common occurrence, there are only a few studies on this topic so far. The aim of this study was to investigate possible physiological aspects of PMD. METHOD: Seventeen men complaining of PMD and 10 healthy subjects were assessed via uroflometry, IPSS questionnaire, IIEF-5 questionnaire, and an adapted visual analogue scale (VAS) for ejaculation force -(0-10) and the amount of bother concerning PMD (0-10) were completed. In addition to that, a retrograde urethrography at 40 and 60 cm water column as pressure unit to measure the width of the bulbar urethra was performed, and the amount of PMD was measured with an adjusted pad test. RESULTS: The PMD group showed a significantly worse IPSS score, a lower Qmax rate in uroflowmetry, a worse IIEF-5 score, and a worse VAS score concerning ejaculation force. In both groups, worse IPSS levels correlated with a low bulbar urethral diameter at 40 and 60 cm water column. -Another correlation was found between a high maximum urine flow rate and a larger bulbar urethral diameter at 40 and 60 cm. Both groups showed urine loss after micturition, with no bother (VAS 0) in the control group, whereas the PMD group showed a VAS of 6. CONCLUSIONS: PMD should be regarded as a physiological occurrence in men rather than a disease by itself. Suffering is only to be expected in combination with other lower urinary tract symptoms.


Asunto(s)
Trastornos Urinarios/fisiopatología , Micción , Urodinámica , Adulto , Anciano , Estudios de Casos y Controles , Eyaculación , Humanos , Masculino , Persona de Mediana Edad , Fenómenos Fisiológicos , Estudios Prospectivos , Reología , Índice de Severidad de la Enfermedad , Encuestas y Cuestionarios , Uretra/fisiopatología , Adulto Joven
18.
Cell ; 176(5): 952-965, 2019 02 21.
Artículo en Inglés | MEDLINE | ID: mdl-30794780

RESUMEN

Complex multicellular organisms, such as mammals, express two complete sets of chromosomes per nucleus, combining the genetic material of both parents. However, epigenetic studies have demonstrated violations to this rule that are necessary for mammalian physiology; the most notable parental allele expression phenomenon is genomic imprinting. With the identification of endogenous imprinted genes, genomic imprinting became well-established as an epigenetic mechanism in which the expression pattern of a parental allele influences phenotypic expression. The expanding study of genomic imprinting is revealing a significant impact on brain functions and associated diseases. Here, we review key milestones in the field of imprinting and discuss mechanisms and systems in which imprinted genes exert a significant role.


Asunto(s)
Impresión Genómica/genética , Impresión Genómica/fisiología , Mamíferos/genética , Alelos , Animales , Evolución Biológica , Cromosomas , Metilación de ADN , Epigénesis Genética/genética , Epigénesis Genética/fisiología , Mamíferos/metabolismo , Fenómenos Fisiológicos
19.
Environ Toxicol Chem ; 38(5): 978-987, 2019 05.
Artículo en Inglés | MEDLINE | ID: mdl-30756430

RESUMEN

Physiologically based toxicokinetic (PBTK) modeling enables researchers to predict internal tissue concentrations for various species exposed to exogenous compounds through different routes at varying concentrations without having to run in vivo experiments for each scenario. Parameters for the models may be gathered from in vivo or in vitro measurements, cross-species or cross-chemical extrapolations, literature reviews, or other models. The PBTK models, described using ordinary differential equations (ODEs), are then simulated using these parameters for a given compound/exposure/species scenario. Although they are potentially useful for regulatory toxicology, the complexity of ODE programming and simulation remains a barrier for many would-be researchers. Petri nets, a graphical modeling framework, offers a more intuitive approach to PBTK modeling. To demonstrate their utility and ease of use, we present a model of waterborne fluoranthene exposure to rainbow trout (Oncorhynchus mykiss) written and simulated in Snoopy, a graphical Petri net development and simulation software package. We converted an existing ODE PBTK model and evaluated the Petri net model against the ODE model results. The simulated tissue concentrations of the Petri net model closely mirrored the simulated concentrations of the ODE model. To convert the ODE model to a Petri net model, we introduced a new parameter, blood volume (V BLOOD ). Sensitivity analysis found V BLOOD to be very robust when varied over an order of magnitude. The resulting Petri net PBTK model has a number of advantages over ODE models, while maintaining equivalent predictive functionality. Environ Toxicol Chem 2019;00:1-10. © 2019 SETAC.


Asunto(s)
Modelos Biológicos , Fenómenos Fisiológicos , Toxicocinética , Animales , Simulación por Computador , Fluorenos/toxicidad , Oncorhynchus mykiss/fisiología , Factores de Tiempo
20.
Proc Natl Acad Sci U S A ; 116(5): 1633-1638, 2019 01 29.
Artículo en Inglés | MEDLINE | ID: mdl-30647112

RESUMEN

Recent studies have called into question the idea that facial masculinity is a condition-dependent male ornament that indicates immunocompetence in humans. We add to this growing body of research by calculating an objective measure of facial masculinity/femininity using 3D images in a large sample (n = 1,233) of people of European ancestry. We show that facial masculinity is positively correlated with adult height in both males and females. However, facial masculinity scales with growth similarly in males and females, suggesting that facial masculinity is not exclusively a male ornament, as male ornaments are typically more sensitive to growth in males compared with females. Additionally, we measured immunocompetence via heterozygosity at the major histocompatibility complex (MHC), a widely-used genetic marker of immunity. We show that, while height is positively correlated with MHC heterozygosity, facial masculinity is not. Thus, facial masculinity does not reflect immunocompetence measured by MHC heterozygosity in humans. Overall, we find no support for the idea that facial masculinity is a condition-dependent male ornament that has evolved to indicate immunocompetence.


Asunto(s)
Cara/fisiología , Complejo Mayor de Histocompatibilidad/fisiología , Adolescente , Adulto , Belleza , Conducta de Elección/fisiología , Femenino , Heterocigoto , Humanos , Inmunocompetencia/fisiología , Masculino , Masculinidad , Fenómenos Fisiológicos/fisiología , Caracteres Sexuales , Conducta Sexual/fisiología , Adulto Joven
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA