RESUMEN

Tropical forests sustain many ant species whose mating events often involve conspicuous flying swarms of winged gynes and males. The success of these reproductive flights depends on environmental variables and determines the maintenance of local ant diversity. However, we lack a strong understanding of the role of environmental variables in shaping the phenology of these flights. Using a combination of community-level analyses and a time-series model on male abundance, we studied male ant phenology in a seasonally wet lowland rainforest in the Panama Canal. The male flights of 161 ant species, sampled with 10 Malaise traps during 58 consecutive weeks (from August 2014 to September 2015), varied widely in number (mean = 9.8 weeks, median = 4, range = 1 to 58). Those species abundant enough for analysis (n = 97) flew mainly towards the end of the dry season and at the start of the rainy season. While litterfall, rain, temperature, and air humidity explained community composition, the time-series model estimators elucidated more complex patterns of reproductive investment across the entire year. For example, male abundance increased in weeks when maximum daily temperature increased and in wet weeks during the dry season. On the contrary, male abundance decreased in periods when rain receded (e.g., at the start of the dry season), in periods when rain fell daily (e.g., right after the beginning of the wet season), or when there was an increase in the short-term rate of litterfall (e.g., at the end of the dry season). Together, these results suggest that the BCI ant community is adapted to the dry/wet transition as the best timing of reproductive investment. We hypothesize that current climate change scenarios for tropical regions with higher average temperature, but lower rainfall, may generate phenological mismatches between reproductive flights and the adequate conditions needed for a successful start of the colony.

Asunto(s)

Hormigas , Clima Tropical , Animales , Cambio Climático , Bosques , Masculino , Lluvia , Estaciones del Año , Árboles

RESUMEN

The objective of this study was to evaluate the association between progesterone concentration on Days 4 and 9 of the estrus cycle and endometrial transcriptome at Day 9 in lactating grazing dairy cows. Blood samples were obtained on Days 0, 4, and 9 for progesterone measurement by chemiluminescence. Cows were assigned to one of the following groups (n = 3 per group): cows with low physiological progesterone on Day 4, cows in anestrous, cows with high physiological progesterone on Day 4, and superovulated cows. Endometrial biopsy samples were obtained on Day 9 for RNA sequencing. Quality control and determination of differentially expressed genes (false discovery rate <0.05) were determined using the edgeR package for R software. We identified 3,042 differentially expressed genes among the 4 groups. Cows having high physiological progesterone and superovulated cows showed high similarities and clustered apart from those in anestrus or having low physiological progesterone. Functional analysis using Database for Annotation, Visualization, and Integrated Discovery revealed that endometrial genes upregulated by low progesterone concentration are enriched genes involved in the immune system and inflammatory response. Conversely, cows with high physiological progesterone concentration presented an endometrial transcriptome with similarities to cows with good genetic merit for fertility, showing upregulation of genes related to uterine relaxation-contraction, focal adhesion, GnRH signaling pathway, and epidermal growth factor-like related terms, suggesting a favorable embryo environment. In conclusion, our results support the concept that there is a threshold of progesterone concentration at the beginning of the luteal phase associated with endometrial expression of critical genes involved in the preparation of the uterine environment for embryo implantation.

Asunto(s)

Enfermedades de los Bovinos/metabolismo , Endometritis/veterinaria , Endometrio/metabolismo , Ciclo Estral/fisiología , Inflamación/veterinaria , Progesterona/metabolismo , Animales , Bovinos , Regulación hacia Abajo , Endometritis/metabolismo , Femenino , Fertilidad/fisiología , Regulación de la Expresión Génica/fisiología , Inflamación/metabolismo , ARN/genética , ARN/metabolismo , Regulación hacia Arriba

RESUMEN

This study was conducted to compare efficacy of treatments with EB or GnRH and different quantities of exogenous progesterone (P4) for synchronization of time of ovulation on follicular growth and pregnancy in lactating dairy cows. In Experiment 1, 40 cows were treated with EB or GnRH and 1.9 or 3.0 g of P4 via progesterone-containing intravaginal devices (IVPD; D0), two doses of PGF2α on D7, GnRH on D9, and TAI on D10. In Experiment 2, 1,440 cows were treated with EB or GnRH and 1 g IVPD on D0, cloprostenol, eCG and EB on D7. Cows in estrus by 48 h were AIDE, and non-estrous cows were administered GnRH and TAI 60 h after IVPD removal. Non-estrous cows were AIDE 72 h after IVPD removal. In Experiment 1, P4 was greater on D7 for cows treated with GnRH than those treated with EB. The dominant follicle was larger for cows treated with GnRH than those treated with EB. In Experiment 2, for estrous cows, pregnancy per AI was greater in cows AI at 48 h compared to 60 h after IVPD removal for cows treated with GnRH, and greater with AI at 60 h after IVPD removal compared to 48 h in EB-treated cows. In non-estrous cows, there was no effect on pregnancy. In conclusion, treatment with GnRH compared with EB resulted in increased P4 regardless of amount of exogenous P4, and there were differential proportions of estrous cows pregnant depending on time of AI after IVPD removal.

Asunto(s)

Bovinos/fisiología , Estradiol/farmacología , Hormona Liberadora de Gonadotropina/farmacología , Lactancia/fisiología , Folículo Ovárico/efectos de los fármacos , Progesterona/farmacología , Administración Intravaginal , Animales , Estradiol/administración & dosificación , Femenino , Hormona Liberadora de Gonadotropina/administración & dosificación , Inseminación Artificial/veterinaria , Paridad , Embarazo , Progesterona/administración & dosificación

RESUMEN

Interpretation of brain activity responses using motor imagery (MI) paradigms is vital for medical diagnosis and monitoring. Assessed by machine learning techniques, identification of imagined actions is hindered by substantial intra- and inter-subject variability. Here, we develop an architecture of Convolutional Neural Networks (CNN) with an enhanced interpretation of the spatial brain neural patterns that mainly contribute to the classification of MI tasks. Two methods of 2D-feature extraction from EEG data are contrasted: Power Spectral Density and Continuous Wavelet Transform. For preserving the spatial interpretation of extracting EEG patterns, we project the multi-channel data using a topographic interpolation. Besides, we include a spatial dropping algorithm to remove the learned weights that reflect the localities not engaged with the elicited brain response. We evaluate two labeled scenarios of MI tasks: bi-class and three-class. Obtained results in an MI database show that the thresholding strategy combined with Continuous Wavelet Transform improves the accuracy and enhances the interpretability of CNN architecture, showing that the highest contribution clusters over the sensorimotor cortex with a differentiated behavior of rhythms [Formula: see text] and [Formula: see text].

RESUMEN

Electromagnetic source imaging (ESI) techniques have become one of the most common alternatives for understanding cognitive processes in the human brain and for guiding possible therapies for neurological diseases. However, ESI accuracy strongly depends on the forward model capabilities to accurately describe the subject's head anatomy from the available structural data. Attempting to improve the ESI performance, we enhance the brain structure model within the individual-defined forward problem formulation, combining the head geometry complexity of the modeled tissue compartments and the prior knowledge of the brain tissue morphology. We validate the proposed methodology using 25 subjects, from which a set of magnetic-resonance imaging scans is acquired, extracting the anatomical priors and an electroencephalography signal set needed for validating the ESI scenarios. Obtained results confirm that incorporating patient-specific head models enhances the performed accuracy and improves the localization of focal and deep sources.

Asunto(s)

Electroencefalografía/métodos , Cabeza/anatomía & histología , Cabeza/diagnóstico por imagen , Modelación Específica para el Paciente/estadística & datos numéricos , Adolescente , Encéfalo/anatomía & histología , Encéfalo/diagnóstico por imagen , Mapeo Encefálico/métodos , Mapeo Encefálico/estadística & datos numéricos , Niño , Preescolar , Biología Computacional , Electroencefalografía/estadística & datos numéricos , Fenómenos Electromagnéticos , Humanos , Procesamiento de Imagen Asistido por Computador/estadística & datos numéricos , Imagen por Resonancia Magnética/estadística & datos numéricos , Modelos Neurológicos , Neuroimagen/estadística & datos numéricos

RESUMEN

The development of high-throughput technologies such as next-generation sequencing for DNA sequencing together with the decrease in their cost has led to the progressive introduction of genomic profiling in our daily practice in oncology. Nowadays, genomic profiling is part of genetic counseling, cancer diagnosis, molecular characterization, and as a biomarker of prognosis and response to treatment. Furthermore, germline or somatic genomic characterization of the tumor may provide new treatment opportunities for patients with cancer. In this review, we will summarize the clinical applications and limitations of genomic profiling in oncology clinical practice, focusing on next-generation sequencing.

Asunto(s)

Biomarcadores de Tumor/genética , Mutación , Neoplasias/genética , Asesoramiento Genético/métodos , Genómica/métodos , Secuenciación de Nucleótidos de Alto Rendimiento/métodos , Humanos , Oncología Médica/métodos , Neoplasias/tratamiento farmacológico , Neoplasias/patología , Medicina de Precisión/métodos , Pronóstico

RESUMEN

INTRODUCTION: Goblet cell carcinoma (GCC) is an appendicular neoplasia representing less than 5% of all appendicular tumors, found in 0.3-0.9% of the appendectomies, 35-58% of all appendicular neoplasms, and less than 14% of malign appendix tumors. The most frequent clinical presentation is abdominal pain associated with a picture of acute appendicitis. MATERIALS AND METHODS: We present 3 clinical cases of appendix GCC, 2 subjected to cytoreductory surgery plus intraperitoneal hyperthermic chemotherapy and a third, who is currently receiving neoadjuvant treatment with a good response to chemotherapy and who will be offered the same treatment as the first two patients. Given the unpredictable behavior of these tumors, the use of molecular markers could help us to predict their behavior and prognosis. In this context, the TP73 gene would make an interesting putative marker. ∆Np73 has been described as overexpressed in a great variety of tumor types including colon cancer and this up-regulation is associated with a poor prognosis. To evidence its role in this malignancy, we evaluate here the status of ∆Np73 in the primary tumor and normal counterpart tissues, in the metastatic implants and in healthy areas of the peritoneum from the appendicular GCC patients. In addition, we checked the expression levels of this p73 variant in the tumor and normal tissue of 26 patients with colon cancer. RESULTS: Remarkably, 2 patients showed significant ∆Np73 down-regulation in both the primary tumor and the implants. Case 1 presented a fourfold decrease of levels in the primary tumor and 20-fold decrease in the implants. Case 2 showed a seven- and fourfold down-regulation in the primary tumor and implants, respectively. However, Case 3 showed an up-regulation of 53- and threefold in the primary tumor and implants, respectively. CONCLUSION: Goblet cell carcinoma of the appendix is very rate. It tends to seed throughout the peritoneum, making aggressive surgical cytoreduction and chemotherapy viable treatment options. Investigation into the molecular basis of these tumors may improve the diagnosis, prognosis and therapeutic decisions regarding these patients. ∆Np73 seems a good candidate for further analysis in longer series.

Asunto(s)

Adenocarcinoma/química , Neoplasias del Apéndice/química , Biomarcadores de Tumor/análisis , Células Caliciformes/química , Neoplasias Ováricas/química , Neoplasias Peritoneales/química , Proteína Tumoral p73/análisis , Adenocarcinoma/secundario , Adenocarcinoma/terapia , Neoplasias del Apéndice/patología , Neoplasias del Apéndice/terapia , Colon/química , Neoplasias del Colon/química , Procedimientos Quirúrgicos de Citorreducción , Regulación hacia Abajo , Femenino , Humanos , Hipertermia Inducida , Masculino , Persona de Mediana Edad , Neoplasias Ováricas/secundario , Neoplasias Peritoneales/secundario , Peritoneo/química

RESUMEN

In the recent past, estimating brain activity with magneto/electroencephalography (M/EEG) has been increasingly employed as a noninvasive technique for understanding the brain functions and neural dynamics. However, one of the main open problems when dealing with M/EEG data is its non-Gaussian and nonstationary structure. In this paper, we introduce a methodology for enhancing the data covariance estimation using a weighted combination of multiple Gaussian kernels, termed WM-MK, that relies on the Kullback-Leibler divergence for associating each kernel weight to its relevance. From the obtained results of validation on nonstationary and non-Gaussian brain activity (simulated and real-world EEG data), WM-MK proves that the accuracy of the source estimation raises by more effectively exploiting the measured nonlinear structures with high time and space complexity.

Asunto(s)

Electroencefalografía/estadística & datos numéricos , Magnetoencefalografía/métodos , Magnetoencefalografía/estadística & datos numéricos , Modelos Estadísticos , Simulación por Computador , Electroencefalografía/métodos , Humanos

RESUMEN

The early detection of Alzheimer's disease and quantification of its progression poses multiple difficulties for machine learning algorithms. Two of the most relevant issues are related to missing data and results interpretability. To deal with both issues, we introduce a methodology to predict conversion of mild cognitive impairment patients to Alzheimer's from structural brain MRI volumes. First, we use morphological measures of each brain structure to build an instance-based feature mapping that copes with missed follow-up visits. Then, the extracted multiple feature mappings are combined into a single representation through the convex combination of reproducing kernels. The weighting parameters per structure are tuned based on the maximization of the centered-kernel alignment criterion. We evaluate the proposed methodology on a couple of well-known classification machines employing the ADNI database devoted to assessing the combined prognostic value of several AD biomarkers. The obtained experimental results show that our proposed method of Instance-based representation using multiple kernel learning enables detecting mild cognitive impairment as well as predicting conversion to Alzheimers disease within three years from the initial screening. Besides, the brain structures with larger combination weights are directly related to memory and cognitive functions.

Asunto(s)

Enfermedad de Alzheimer/diagnóstico por imagen , Disfunción Cognitiva/diagnóstico por imagen , Progresión de la Enfermedad , Interpretación de Imagen Asistida por Computador/métodos , Procesamiento de Imagen Asistido por Computador/métodos , Aprendizaje Automático , Imagen por Resonancia Magnética/métodos , Neuroimagen/métodos , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Pronóstico

RESUMEN

TP73 is a member of the TP53 family whose expression has been observed altered in most human cancers and associated with the prognosis. TP73 translates into a complex number of isoforms with both oncogenic and tumour-suppressor functions and presents a complex cross-talk with other members of the family (TP53 and TP63). In this revision, we focus on the evidence that may support TP73 variants as prognostic markers in cancer. Nowadays, most publications in this topic highlight the association between overexpression of the oncogenic variants and failure to respond to chemotherapy and/or shorter survival. In addition, we comment on the putative possibilities that the detection through a liquid biopsy of TP73 variants may provide, and finally, the significance of determining the value of the combined alteration of the TP53 family members in the clinical setting.

Asunto(s)

Regulación Neoplásica de la Expresión Génica , Neoplasias/genética , Neoplasias/patología , Proteína Tumoral p73/genética , Animales , Humanos , Isoformas de Proteínas

RESUMEN

Resumen: ANTECEDENTES: la inducción del trabajo de parto es un procedimiento que se indica cuando existe riesgo de continuar el embarazo, en lugar de interrumpirlo. Esta maniobra enfrenta nuevas presiones, por lo que es necesario mantener actualizado el conocimiento sobre su indicación. En los últimos años se han desarrollado protocolos clínicos de mayor eficacia y seguridad, que han hecho más accesible este procedimiento. OBJETIVO: emitir un consenso actualizado y analizar los diferentes aspectos de la práctica cotidiana relacionada con la inducción del trabajo de parto. MATERIALES Y MÉTODOS: se integró un grupo de especialistas de trece instituciones nacionales para analizar diferentes aspectos de la práctica cotidiana de la inducción del trabajo de parto. Se siguió una metodología tipo Delphi de cuatro etapas, con bibliografía de normas clínicas internacionales de apoyo. CONCLUSIONES: la inducción del trabajo de parto considera los siguientes criterios: establecer con certeza que el procedimiento ofrece el mejor desenlace para la madre y el feto, confirmar la edad gestacional, realizar la evaluación obstétrica completa y contar con infraestructura para enfrentar las posibles complicaciones. Existen diferentes opciones para la inducción del trabajo de parto; sin embargo, en los últimos años se ha generalizado la prescripción de análogos de prostaglandinas (misoprostol) en todo el mundo. El especialista debe efectuar la evaluación individualizada de la paciente y el feto, con la finalidad de descartar situaciones que comprometan la salud de ambos. La complicación más común de la inducción del trabajo de parto es la taquisistolia, que puede asociarse con desprendimiento prematuro de placenta, rotura uterina y sufrimiento fetal agudo. Los óvulos vaginales de liberación controlada representan la única opción para retirar el estímulo con dinoprostona o misoprostol ante efectos adversos.

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Abstract: BACKGROUND: Induction of labor is a maneuver indicated when there is a greater risk of continuing the pregnancy, than interrupting it. The induction of labor faces new pressures that make it necessary for the doctor to be permanently updated. In recent years, clinical protocols of greater efficiency and safety have been developed, which have made this procedure more accessible. OBJECTIVE: To present an updated consensus and to analyze the different aspects related to the labor induction. MATERIAL AND METHODS: A Delphi-type of consensus was conducted with participation of active obstetricians and gynecologists specialists from thirteen national institutions. Major clinical-oriented topics of induction of labor were addressed. CONCLUSIONS: To induce labor, it is necessary that at least the following situations coexist: to establish with certainty that the procedure offers the best outcome for the mother and her child, to confirm the gestational age, to make a complete obstetric evaluation and to have the infrastructure Necessary to deal with possible complications. There are several options to induce labor, although in recent years the indication of prostaglandin analogues (misoprostol) has become the most common option worldwide. The specialist must make an individualized evaluation of the patient and the fetus, in order to rule out situations that may endanger the health of any of them. The most common complication of labor induction is tachysystole, which can be complicated by premature placental abruption, uterine rupture and acute fetal distress, requiring urgent attention. Controlled-release vaginal ovules are the only option available to withdraw the stimulus with dinoprostone or misoprostol in the presence of adverse effects.

RESUMEN

We studied the participation of GABA neurotransmission in the medial preoptic area (mPOA) with respect to the onset of the pup retrieval response and nest building. Pregnant female rats were implanted with bilateral cannulae in the mPOA on day 12 of pregnancy and, on day 16, the females were hysterectomised and ovariectomised and given 200 µg/kg of oestradiol benzoate. Two days later, the females received one of the following intracerebral drug treatments: GABAB agonist baclofen (200 ng); GABAB antagonist phaclofen (1 µg); GABAA antagonist bicuculline (60 ng); or physiological saline. Five minutes after intracerebral infusion, three foster pups were introduced into the females' home cage. The subjects were observed for pup grouping (retrieval) during 15 min, after which the pups were left with the female. During the next 12 h, an observation was made every 1 h to determine whether the pups had been grouped (retrieved) or not. The GABAB agonist baclofen reduced the proportion of females retrieving pups from 4 to 8 h following pup introduction. By contrast, both the GABAA antagonist bicuculline and the GABAB antagonist phaclofen enhanced the proportion of females retrieving pups during the first 3 h of observation. The latency to pup retrieval in subjects treated with the GABAB agonist baclofen was significantly longer than that in subjects given any of the antagonists. All females built a nest but baclofen reduced nest quality. These data show that activation of GABAB receptors in the mPOA has an inhibitory effect on basic maternal behaviours, whereas blockade of either the GABAA or GABAB receptor facilitates pup retrieval. It is possible that reduced GABAergic tone in the mPOA is a key element in the initiation of maternal behaviours in postparturient rats.

Asunto(s)

Estradiol/fisiología , Conducta Materna , Área Preóptica/fisiología , Receptores de GABA-A/fisiología , Receptores de GABA-B/fisiología , Animales , Baclofeno/administración & dosificación , Baclofeno/análogos & derivados , Bicuculina/administración & dosificación , Femenino , Antagonistas de Receptores de GABA-A/administración & dosificación , Agonistas de Receptores GABA-B/administración & dosificación , Antagonistas de Receptores de GABA-B/administración & dosificación , Histerectomía , Conducta Materna/efectos de los fármacos , Comportamiento de Nidificación/efectos de los fármacos , Ovariectomía , Embarazo , Área Preóptica/efectos de los fármacos , Ratas Wistar

RESUMEN

We present a novel iterative regularized algorithm (IRA) for neural activity reconstruction that explicitly includes spatiotemporal constraints, performing a trade-off between space and time resolutions. For improving the spatial accuracy provided by electroencephalography (EEG) signals, we explore a basis set that describes the smooth, localized areas of potentially active brain regions. In turn, we enhance the time resolution by adding the Markovian assumption for brain activity estimation at each time period. Moreover, to deal with applications that have either distributed or localized neural activity, the spatiotemporal constraints are expressed through [Formula: see text] and [Formula: see text] norms, respectively. For the purpose of validation, we estimate the neural reconstruction performance in time and space separately. Experimental testing is carried out on artificial data, simulating stationary and non-stationary EEG signals. Also, validation is accomplished on two real-world databases, one holding Evoked Potentials and another with EEG data of focal epilepsy. Moreover, responses of functional magnetic resonance imaging for the former EEG data have been measured in advance, allowing to contrast our findings. Obtained results show that the [Formula: see text]-based IRA produces a spatial resolution that is comparable to the one achieved by some widely used sparse-based estimators of brain activity. At the same time, the [Formula: see text]-based IRA outperforms other similar smooth solutions, providing a spatial resolution that is lower than the sparse [Formula: see text]-based solution. As a result, the proposed IRA is a promising method for improving the accuracy of brain activity reconstruction.

Asunto(s)

Algoritmos , Mapeo Encefálico/métodos , Encéfalo/fisiología , Electroencefalografía/métodos , Simulación por Computador , Bases de Datos Factuales , Humanos , Imagen por Resonancia Magnética/métodos , Cadenas de Markov , Modelos Neurológicos , Procesamiento de Señales Asistido por Computador , Factores de Tiempo

RESUMEN

The use of composite edible films made from biopolymers has attracted interest as a way to reduce pollution and recycling problems; however, the relation between barrier, mechanical and structural properties of the films have been scarcely studied. The aim of this work was to evaluate composite zein-chitosan edible films by applying common nanotechnology tools and to relate the results to zein concentration and film structural changes. Rougher, more elastic, and less hard film structures with better water vapour barrier properties were obtained using larger zein concentrations. Raman spectroscopy exhibited unexpected interactions, as indicated by the disappearance of the thiol groups of cysteine in the zein films and the appearance of O=S=O and C-O-S groups in the blended materials in conjunction with the disappearance of zein ε-amino and -NH2 functional groups in the zein film samples, thereby confirming changes in the blended film structure. Zein concentration presented linear correlations with water vapour permeability (R=-0.978) and film roughness (R=0.929). The composite films presented better barrier and mechanical properties than single ingredient films. This information shows the benefit of using protein-polysaccharide blends to prepare edible films.

Asunto(s)

Quitosano/química , Nanotecnología , Plantas Comestibles/química , Zeína/química , Fenómenos Biomecánicos , Microscopía de Fuerza Atómica , Permeabilidad , Espectrometría Raman , Difracción de Rayos X

RESUMEN

The computer-assisted analysis of biomedical records has become an essential tool in clinical settings. However, current devices provide a growing amount of data that often exceeds the processing capacity of normal computers. As this amount of information rises, new demands for more efficient data extracting methods appear. This paper addresses the task of data mining in physiological records using a feature selection scheme. An unsupervised method based on relevance analysis is described. This scheme uses a least-squares optimization of the input feature matrix in a single iteration. The output of the algorithm is a feature weighting vector. The performance of the method was assessed using a heartbeat clustering test on real ECG records. The quantitative cluster validity measures yielded a correctly classified heartbeat rate of 98.69% (specificity), 85.88% (sensitivity) and 95.04% (general clustering performance), which is even higher than the performance achieved by other similar ECG clustering studies. The number of features was reduced on average from 100 to 18, and the temporal cost was a 43% lower than in previous ECG clustering schemes.

Asunto(s)

Electrocardiografía/métodos , Contracción Miocárdica , Humanos

RESUMEN

OBJECTIVES: The use of magnets in transumbilical cholecystectomy improves triangulation and achieves optimal critical view. However, the attraction between magnets can cause collisions and their management complicates the procedure, and this will become more important in children. In order to simplify the technique, we have developed a hybrid model with a single magnet. MATERIAL AND METHODS: Retrospective review of cholecystectomies performed in our department between June 2011 and July 2012. The technique combines the use of a magnet and a curved grasper. Through transumbilical incision, a 12 mm trocar and another flexible 5 mm are placed. Laparoscope with working channel uses the 12 mm trocar. The magnet is introduced to the abdominal cavity using the working channel to provide cephalad retraction of gallbladder fundus. Curved grasper is run by the assistant to mobilize the infundibulum across flexible trocar. The surgeon operates through the working channel of the laparoscope. RESULTS: Twenty-six patients were operated on with this technique. Mean age was 14 years (4-17) and weight 50 kg (18-90). 65% were girls. The mean operative time was 62 minutes (50-70) and the critical view of safety was achieved in all cases. Instrumental collision or hands crossing were not seen. There were no intraoperative or postoperative complications. The hospital stay was 1.4 +/- 0.6 days and the median follow-up 201 days (42-429). CONCLUSIONS: The hybrid technique, combining magnet and a curved grasper, simplifies transumbilical surgery. It seems a feasible and safe for transumbilical cholecystectomy and potentially reproducible.

Asunto(s)

Colecistectomía Laparoscópica/métodos , Adolescente , Niño , Preescolar , Femenino , Humanos , Masculino , Estudios Retrospectivos , Ombligo

RESUMEN

A large proportion of cardiovascular diseases might be preventable, however, majority of this diseases occurs in rural areas where there is a poor presence of cardiologists. To overcome this issue, the use of wearable devices within the telemedicine framework would be of benefit. However, implementation of processing algorithms in smart-phones at mobile environments imposes restrictions ensuring high measurement quality of acquired ECG data, while maintaining low computation burden. This work presents an algorithm for scoring the quality of measured ECG recordings is developed. Particularly, a quality score is provided that takes into account the proportional correlation observed in acceptable signals based on a diversity scheme, and their inverse relation with standard deviation. Testing of proposed algorithm is carried out upon two different databases, the first one is of own production, while the second one is obtained from Physionet. As a result, high values of sensitivity and specificity are achieved.

Asunto(s)

Algoritmos , Arritmias Cardíacas/diagnóstico , Diagnóstico por Computador/métodos , Electrocardiografía/métodos , Humanos , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Estadística como Asunto

RESUMEN

Biosignal recordings are widely used in the medical environment to support the evaluation and the diagnosis of pathologies. Nevertheless, the main difficulty lies in the non-stationary behavior of the biosignals, difficulting the obtention of patterns characterizing the changes in physiological or pathological states. Thus, the obtention of the stationary and non-stationary components of a biosignal is still an open issue. This work proposes a methodology to detect time-homogeneities based on time-frequency analysis with aim to extract the non-stationary behavior of the biosignal. Results show an increase in the stationarity and in the distance between classes of the reconstructions from the enhanced time-frequency representations. The stationary components extracted with the proposed approach can be used to solve biosignal classification problems.

Asunto(s)

Electroencefalografía/métodos , Epilepsia/fisiopatología , Modelos Biológicos , Procesamiento de Señales Asistido por Computador , Relación Señal-Ruido , Bases de Datos Factuales , Femenino , Humanos , Masculino

RESUMEN

Microelectrode recordings are a valuable tool for assisting localization targets during deep brain stimulation procedures in Parkinson's disease neurosurgery. Attempts to automate and standardize this process have been limited by variability in patient neurophysiology and strong dynamics of microelectrode recordings. In this paper, a methodology for the identification of basal ganglia nuclei is presented that is based on a signal-dependent filter bank method using microelectrode recordings. The method is a customized realization of the discrete wavelet transform via the lifting scheme that is optimally tuned by genetic algorithms. Using this method, unique mother wavelet functions that exhibit an adaptable spectrum to the microelectrode recording dynamic are generated. Additionally, by extracting morphological features from the space-transformed microelectrode recording, it is possible to integrate them into three-dimensional (3D) feature spaces with maximum class separability. Finally, high discriminant feature spaces are fed into basic classifiers to recognize up to four basal nuclei. Comparison with several existing wavelets highlights the characteristics of new mother wavelets. Additionally, classification results show that identification of addressed nuclei in the basal ganglia can be performed with 95% confidence.

Asunto(s)

Potenciales de Acción , Algoritmos , Ganglios Basales/fisiopatología , Diagnóstico por Computador/métodos , Electroencefalografía/métodos , Enfermedad de Parkinson/diagnóstico , Enfermedad de Parkinson/fisiopatología , Humanos , Sensibilidad y Especificidad , Procesamiento de Señales Asistido por Computador

RESUMEN

The estimation of current distributions from electroencephalographic recordings poses an inverse problem, which can approximately be solved by including dynamical models as spatio-temporal constraints onto the solution. In this paper, we consider the electrocardiography source localization task, where a specific structure for the dynamical model of current distribution is directly obtained from the data by fitting multivariate autoregressive models to electroencephalographic time series. Whereas previous approaches consider an approximation of the internal connectivity of the sources, the proposed methodology takes into account a realistic structure of the model estimated from the data, such that it becomes possible to obtain improved inverse solutions. The performance of the new method is demonstrated by application to simulated electroencephalographic data over several signal to noise ratios, where the source localization task is evaluated by using the localization error and the data fit error. Finally, it is shown that estimating MVAR models makes possible to obtain inverse solutions of considerably improved quality, as compared to the usual instantaneous inverse solutions, even if the regularized inverse of Tikhonov is used.

Asunto(s)

Electroencefalografía/métodos , Procesamiento de Señales Asistido por Computador , Algoritmos , Encéfalo/patología , Simulación por Computador , Análisis de Elementos Finitos , Humanos , Imagenología Tridimensional , Modelos Lineales , Modelos Estadísticos , Análisis Multivariante , Análisis de Regresión , Reproducibilidad de los Resultados , Relación Señal-Ruido , Factores de Tiempo