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1.
J Neurosci ; 44(17)2024 Apr 24.
Artículo en Inglés | MEDLINE | ID: mdl-38438256

RESUMEN

Recognizing faces regardless of their viewpoint is critical for social interactions. Traditional theories hold that view-selective early visual representations gradually become tolerant to viewpoint changes along the ventral visual hierarchy. Newer theories, based on single-neuron monkey electrophysiological recordings, suggest a three-stage architecture including an intermediate face-selective patch abruptly achieving invariance to mirror-symmetric face views. Human studies combining neuroimaging and multivariate pattern analysis (MVPA) have provided convergent evidence of view selectivity in early visual areas. However, contradictory conclusions have been reached concerning the existence in humans of a mirror-symmetric representation like that observed in macaques. We believe these contradictions arise from low-level stimulus confounds and data analysis choices. To probe for low-level confounds, we analyzed images from two face databases. Analyses of image luminance and contrast revealed biases across face views described by even polynomials-i.e., mirror-symmetric. To explain major trends across neuroimaging studies, we constructed a network model incorporating three constraints: cortical magnification, convergent feedforward projections, and interhemispheric connections. Given the identified low-level biases, we show that a gradual increase of interhemispheric connections across network-layers is sufficient to replicate view-tuning in early processing stages and mirror-symmetry in later stages. Data analysis decisions-pattern dissimilarity measure and data recentering-accounted for the inconsistent observation of mirror-symmetry across prior studies. Pattern analyses of human fMRI data (of either sex) revealed biases compatible with our model. The model provides a unifying explanation of MVPA studies of viewpoint selectivity and suggests observations of mirror-symmetry originate from ineffectively normalized signal imbalances across different face views.


Asunto(s)
Reconocimiento Facial , Humanos , Masculino , Femenino , Reconocimiento Facial/fisiología , Adulto , Neuroimagen/métodos , Estimulación Luminosa/métodos , Modelos Neurológicos , Corteza Visual/fisiología , Corteza Visual/diagnóstico por imagen , Imagen por Resonancia Magnética/métodos , Adulto Joven
2.
Artículo en Inglés, Español | MEDLINE | ID: mdl-38710465

RESUMEN

INTRODUCTION: Biological therapies used for the treatment of inflammatory bowel disease (IBD) have shown to be effective and safe, although these results were obtained from studies involving mostly a young population, who are generally included in clinical trials. The aim of our study was to determine the efficacy and safety of the different biological treatments in the elderly population. METHODS: Multicenter study was carried out in the GETECCU group. Patients diagnosed with IBD and aged over 65 years at the time of initiating biological therapy (infliximab, adalimumab, golimumab, ustekinumab or vedolizumab) were retrospectively included. Among the patients included, clinical response was assessed after drug induction (12 weeks of treatment) and at 52 weeks. Patients' colonoscopy data in week 52 were assessment, where available. Regarding complications, development of oncological events during follow-up and infectious processes occurring during biological treatment were collected (excluding bowel infection by cytomegalovirus). RESULTS: A total of 1090 patients were included. After induction, at approximately 12-14 weeks of treatment, 419 patients (39.6%) were in clinical remission, 502 patients (47.4%) had responded without remission and 137 patients (12.9%) had no response. At 52 weeks of treatment 442 patients (57.1%) had achieved clinical remission, 249 patients had responded without remission (32.2%) and 53 patients had no response to the treatment (6.8%). Before 52 weeks, 129 patients (14.8%) had discontinued treatment due to inefficacy, this being significantly higher (p<0.0001) for Golimumab - 9 patients (37.5%) - compared to the other biological treatments analyzed. With respect to tumor development, an oncological event was observed in 74 patients (6.9%): 30 patients (8%) on infliximab, 23 (7.14%) on adalimumab, 3 (11.1%) on golimumab, 10 (6.4%) on ustekinumab, and 8 (3.8%) on vedolizumab. The incidence was significantly lower (p=0.04) for the vedolizumab group compared to other treatments. As regards infections, these occurred in 160 patients during treatment (14.9%), with no differences between the different biologicals used (p=0.61): 61 patients (19.4%) on infliximab, 39 (12.5%) on adalimumab, 5 (17.8%) on golimumab, 22 (14.1%) on ustekinumab, and 34 (16.5%) on vedolizumab. CONCLUSIONS: Biological drug therapies have response rates in elderly patients similar to those described in the general population, Golimumab was the drug that was discontinued most frequently due to inefficacy. In our experience, tumor development was more frequent in patients who used anti-TNF therapies compared to other targets, although its incidence was generally low and that this is in line with younger patients based on previous literature.

3.
Chemphyschem ; 24(9): e202200682, 2023 May 02.
Artículo en Inglés | MEDLINE | ID: mdl-36720702

RESUMEN

The understanding of the molecular- and colloidal-structure of asphaltenes has seen a major progress; however, there are still issues that require answer. One of them is the location of the heteroatoms in the polycyclic aromatic hydrocarbon (PAH) fused aromatic ring (FAR) region of asphaltenes. Therefore, the effect on the frontier molecular orbitals (HOMO-LUMO) energy-gap due to the addition of a heteroatom (N or S) to PAHs, which are candidates of the PAH region in asphaltenes, has been systematically analyzed by placing S or N in various sites of the PAH molecule. The S is introduced as a thiophenic ring in a bay region, while the N is introduced as a pyridinic-N, which are prevalent forms in the asphaltene-PAH. 174 PAHs are studied with five fused aromatic rings (5FAR) to 10FAR. The π-electron allocation in resonant π-sextets and isolated double bonds is obtained using the Y-rule. The frontier orbitals optical transition is calculated with the ZINDO/S method. Within a FAR family an increment of π-sextets produces and increase of the HOMO-LUMO energy-gap. There is a linear relationship between the Y-rule mapping (percentage of fraction of π-sextet bond divided by nFAR) and the HOMO-LUMO energy-gap. In addition, the effect on the frontier orbitals energy-gap and on the π-electronic allocation due to the presence of N and S is negligible; therefore, to reach conclusions related to the asphaltene-PAH based on conclusions reached for PAH systems, with no heteroatoms, is a reasonable approach.

4.
J Strength Cond Res ; 36(4): 1158-1161, 2022 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-32058358

RESUMEN

ABSTRACT: Morin, JB, Capelo-Ramirez, F, Rodriguez-Pérez, MA, Cross, MR, and Jimenez-Reyes, P. Individual adaptation kinetics following heavy resisted sprint training. J Strength Cond Res 36(4): 1158-1161, 2022-The aim of this study was to test individual adaptation kinetics to a high-resistance sprint training program designed to improve maximal horizontal power (Pmax), and compare the group and individual results of a classical "pre-post" analysis, and a "pre-peak" approach. Thirteen male and 9 female trained sprinters had their 30-m sprint performance and mechanical outputs assessed 1 week before (PRE), and one (POST, W1), 2 (W2), 3 (W3) and 4 (W4) weeks after a 10-week training block (10 repetitions of 20-m resisted sprints at the load associated to the apex of their velocity-power relationship: i.e., 90 ± 10% body mass on average (range: 75-112%). We observed clearly different outcomes on all variables for the PRE-POST vs. PRE-PEAK analyses. The PRE-PEAK analysis showed a larger (almost double) increase in Pmax (9.98 ± 5.27% on average, p < 0.01) than the PRE-POST (5.39 ± 5.87%, p < 0.01). Individual kinetics of post-training adaptations show that peak values were not captured in the POST (W1) assessment (generally observed at W3 and W4). Finally, the week of greatest Pmax output differed strongly among subjects, with most subjects (7/22) peaking at W4. In conclusion, after a 10-week high-resistance sprint training block, a classical 1-week-PRE to 1-week-POST assessment could not capture peak adaptation, which differed among athletes. Adopting a similar approach in practice or research should improve insight into the true effects of training stimuli on athletic capabilities.


Asunto(s)
Rendimiento Atlético , Entrenamiento de Fuerza , Carrera , Atletas , Femenino , Humanos , Cinética , Masculino , Entrenamiento de Fuerza/métodos
5.
An Acad Bras Cienc ; 93(3): e20190961, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34105700

RESUMEN

We study a five-parameter model called the Weibull Burr XII (WBXII) distribution, which extends several models, including new ones. This model is quite flexible in terms of the hazard function, which exhibits increasing, decreasing, upside-down bathtub, and bathtub shapes. Its density function allows different forms such as left-skewed, right-skewed, reversed-J, and bimodal. We aim to provide some general mathematical quantities for the proposed distribution, which can be useful to real data analysis. We develop a shiny application to provide interactive illustrations of the WBXII density and hazard functions. We estimate the model parameters using maximum likelihood and derive a profile log-likelihood for all members of the Weibull-G family. The survival analysis application reveals that the WBXII model is suitable to accommodate left-skewed tails, which are very common when the variable of interest is the time to failure of a product. The income application is related to player salaries within a professional sports league and it is peculiar because the mean of the player's salaries is much higher than for most professions. Both applications illustrate that the new distribution provides much better fits than other models with the same and less number of parameters.


Asunto(s)
Distribuciones Estadísticas , Funciones de Verosimilitud , Análisis de Supervivencia
6.
J Chem Inf Model ; 60(2): 611-620, 2020 02 24.
Artículo en Inglés | MEDLINE | ID: mdl-31714770

RESUMEN

In the present contribution, we have developed a database, called the FAR-database, where the acronym FAR stands for Fused Aromatic Rings, which presents the results of nuclear independent chemical shifts calculations, NICS(0), NICS(1), NICS(0)ZZ, and NICS(1)ZZ, of 660 neutral benzenoid-PAHs and cyclopenta-fused PAHs. The FAR-database provides NICS data of aromaticity of PAHs that could be used in data science and machine learning. To the best of our knowledge, no such database is available in the literature. The importance of this database lies in its potential to transform data into insight and knowledge. Additionally, a new visual representation of the NICS aromaticity pattern, based on the magnitude of the NICS value, is presented. Nowadays calculations of NICS(0)ZZ or NICS(1)ZZ have become popular methods to evaluate aromaticity of systems. By looking at all the 660 systems in the FAR-database, it becomes evident that NICS(0), NICS(1), and NICS(1)ZZ present similar NICS aromaticity patterns for most of the systems. But the NICS aromaticity patterns found with NICS(0)ZZ in many cases do not agree with the NICS aromaticity patterns found with NICS(0), NICS(1), and NICS(1)ZZ. There are cases where the NICS(0)ZZ aromaticity pattern does not show an aromatic character at all. From XY NICS scan at planes from Z = 0 to Z = 1, it is found that as the Z-height is increased, the π-electron ring current effects are dominant, and the σ-bonding contributions are diminished. Therefore, it is recommended here to compute NICS(1)ZZ instead of NICS(0)ZZ when analyzing NICS of PAHs.


Asunto(s)
Bases de Datos Farmacéuticas , Hidrocarburos Policíclicos Aromáticos/química , Espectroscopía de Resonancia Magnética , Modelos Moleculares , Conformación Molecular , Teoría Cuántica
7.
Ann Hepatol ; 19(6): 668-673, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32683094

RESUMEN

INTRODUCTION AND OBJECTIVES: The association between non-alcoholic fatty liver disease and cerebral hemodynamics arises from cardiovascular damage mechanisms such as endothelial dysfunction, arterial wall increased stiffness, high thickness of the intimate index of the internal carotid artery, left ventricular hypertrophy, left diastolic dysfunction, calcification coronary arteries and increased epicardial fat. The multidirectional relationship between systemic inflammation and lipid metabolism constitutes a common and simultaneous mechanism that causes vascular damage. This study aims to provide insight into the relationship between non-alcoholic fatty liver disease and the function of systemic circulation and cerebral circulation using Doppler ultrasound. PATIENTS AND METHODS: Is an observational, cross-sectional, prospective, comparative study conducted at Medica Sur Hospital. Thirty-five patients were selected consecutively. The patients consulted neurological service for various symptoms without severity criteria, such as vertigo, primary headache and balance disturbances. RESULTS: There is a difference in the variables mean of the right MCA PI (p = 0.023), left MCA PI" (p = 0.004), and left VA PI (p = 0.036) between the control and NAFLD groups. The correlation analysis between these variables and the CAP showed a positive correlation of the three variables with the CAP, "right MCA PI" (r = 0.384), left MCA PI "(r = 0.509) and" left VA PI " (r = 0.551). CONCLUSIONS: This study demonstrates a subclinical process of the middle cerebral artery in subjects with NAFLD, which suggests it may be involved in the disease development and points the need to make decisions for this liver manifestation prevention and treatment.


Asunto(s)
Arterias Cerebrales/fisiopatología , Venas Cerebrales/fisiopatología , Circulación Cerebrovascular/fisiología , Enfermedad del Hígado Graso no Alcohólico/fisiopatología , Adulto , Anciano , Velocidad del Flujo Sanguíneo/fisiología , Estudios de Casos y Controles , Arterias Cerebrales/diagnóstico por imagen , Venas Cerebrales/diagnóstico por imagen , Estudios Transversales , Femenino , Humanos , Masculino , Persona de Mediana Edad , Enfermedad del Hígado Graso no Alcohólico/diagnóstico por imagen , Estudios Prospectivos , Flujo Pulsátil/fisiología , Ultrasonografía Doppler , Resistencia Vascular/fisiología
8.
J Strength Cond Res ; 34(6): 1581-1590, 2020 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-28700515

RESUMEN

González-Hernández, JM, García-Ramos, A, Castaño-Zambudio, A, Capelo-Ramírez, F, Marquez, G, Boullosa, D, and Jiménez-Reyes, P. Mechanical, metabolic, and perceptual acute responses to different set configurations in full squat. J Strength Cond Res 34(6): 1581-1590, 2020-This study aimed to compare mechanical, metabolic, and perceptual responses between 2 traditional (TR) and 4 cluster (CL) set configurations. In a counterbalanced randomized order, 11 men were tested with the following protocols in separate sessions (sets × repetitions [interrepetition rest]): TR1: 3 × 10 [0 seconds]; TR2: 6 × 5 [0 seconds]; CL1: 3 × 10 [10 seconds]; CL2: 3 × 10 [15 seconds]; CL3: 3 × 10 [30 seconds]; CL4: 1 × 30 [15 seconds]. The exercise (full squat), number of repetitions (30), interset rest (5 minutes), and resistance applied (10 repetition maximum) was the same for all set configurations. Mechanical fatigue was quantified by measuring the mean propulsive velocity during each repetition and the change in countermovement jump height observed after each set and after the whole training session. Metabolic and perceptual fatigue were assessed via the blood lactate concentration and the OMNI perceived exertion scale measured after each training set, respectively. The mechanical, metabolic, and perceptual measures of fatigue were always significantly higher for the TR1 set configuration. The 2 set configurations that most minimized the mechanical measures of fatigue were CL2 and CL3. Perceived fatigue did not differ between the TR2, CL1, CL2, and CL3 set configurations. The lowest lactate concentration was observed in the CL3 set configuration. Therefore, both the CL2 and CL3 set configurations can be recommended because they maximize mechanical performance. However, the CL2 set configuration presents 2 main advantages with respect to CL3 (a): it reduces training session duration, and (b) it promotes higher metabolic stress, which, to some extent, may be beneficial for inducing muscle strength and hypertrophy gains.


Asunto(s)
Ejercicio Físico/fisiología , Fuerza Muscular/fisiología , Percepción , Entrenamiento de Fuerza/métodos , Adulto , Fenómenos Biomecánicos , Humanos , Ácido Láctico/sangre , Masculino , Fatiga Muscular/fisiología , Postura , Descanso/fisiología , Adulto Joven
9.
J Strength Cond Res ; 34(8): 2220-2226, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-29952872

RESUMEN

Párraga-Montilla, JA, García-Ramos, A, Castaño-Zambudio, A, Capelo-Ramírez, F, González-Hernández, JM, Cordero-Rodríguez, Y, and Jiménez-Reyes, P. Acute and delayed effects of a resistance training session leading to muscular failure on mechanical, metabolic, and perceptual responses. J Strength Cond Res 34(8): 2220-2226, 2020-This study explored the acute and delayed (24 and 48 hours after exercise) effects of a resistance training session leading to muscular failure. Eleven resistance-trained men completed a training session consisting on 3 sets of repetitions to failure during the back-squat exercise performed at the maximum possible speed with a load equivalent to a mean propulsive velocity (MPV) of 1 m·s (≈60% of 1 repetition maximum). A number of mechanical (number of repetitions and starting MPV of the set, MPV achieved against the 1MPV load, countermovement jump [CMJ] height, and handgrip strength), metabolic (lactate, uric acid, and ammonia concentrations), and perceptual (OMNI-RES perceived exertion) variables were measured. The results revealed (a) a decrease of 38.7% in set 2 and 54.7% in set 3 of the number of repetitions performed compared with the first set (p < 0.05), (b) a reduction in the MPV of the repetitions and an increase in lactate concentration and OMNI-RES values with the succession of sets (p < 0.05), (c) comparable decrements in CMJ height after the 3 sets (25-32%), (d) a decrease in CMJ height (p < 0.05; 6.7-7.9%) and in the MPV attained against the 1MPV load (p < 0.05; 13-14%) after 24 and 48 hours of completing the training session, but no significant changes were observed in handgrip strength (p > 0.05; <2%), and (e) uric acid and ammonia concentrations above the basal levels (p < 0.05). The large decrements in mechanical performance together with the high metabolic stress discourage the frequent use of resistance training sessions leading to muscular failure.


Asunto(s)
Fatiga Muscular/fisiología , Fuerza Muscular/fisiología , Músculo Esquelético/fisiología , Entrenamiento de Fuerza/métodos , Adolescente , Adulto , Amoníaco/sangre , Fuerza de la Mano , Humanos , Ácido Láctico/sangre , Masculino , Postura , Factores de Tiempo , Ácido Úrico/sangre , Adulto Joven
10.
J Strength Cond Res ; 34(3): 663-670, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-29076963

RESUMEN

García-Ramos, A, González-Hernández, JM, Baños-Pelegrín, E, Castaño-Zambudio, A, Capelo-Ramírez, F, Boullosa, D, Haff, GG, and Jiménez-Reyes, P. Mechanical and metabolic responses to traditional and cluster set configurations in the bench press exercise. J Strength Cond Res 34(3): 663-670, 2020-This study aimed to compare mechanical and metabolic responses between traditional (TR) and cluster (CL) set configurations in the bench press exercise. In a counterbalanced randomized order, 10 men were tested with the following protocols (sets × repetitions [inter-repetition rest]): TR1: 3 × 10 (0-second), TR2: 6 × 5 (0-second), CL5: 3 × 10 (5-second), CL10: 3 × 10 (10-second), and CL15: 3 × 10 (15-second). The number of repetitions (30), interset rest (5 minutes), and resistance applied (10 repetition maximum) were the same for all set configurations. Movement velocity and blood lactate concentration were used to assess the mechanical and metabolic responses, respectively. The comparison of the first and last set of the training session revealed a significant decrease in movement velocity for TR1 (Effect size [ES]: -0.92), CL10 (ES: -0.85), and CL15 (ES: -1.08) (but not for TR2 [ES: -0.38] and CL5 [ES: -0.37]); while blood lactate concentration was significantly increased for TR1 (ES: 1.11), TR2 (ES: 0.90), and CL5 (ES: 1.12) (but not for CL10 [ES: 0.03] and CL15 [ES: -0.43]). Based on velocity loss, set configurations were ranked as follows: TR1 (-39.3 ± 7.3%) > CL5 (-20.2 ± 14.7%) > CL10 (-12.9 ± 4.9%), TR2 (-10.3 ± 5.3%), and CL15 (-10.0 ± 2.3%). The set configurations were ranked as follows based on the lactate concentration: TR1 (7.9 ± 1.1 mmol·L) > CL5 (5.8 ± 0.9 mmol·L) > TR2 (4.2 ± 0.7 mmol·L) > CL10 (3.5 ± 0.4 mmol·L) and CL15 (3.4 ± 0.7 mmol·L). These results support the use of TR2, CL10, and CL15 for the maintenance of high mechanical outputs, while CL10 and CL15 produce less metabolic stress than TR2.


Asunto(s)
Músculo Esquelético/fisiología , Entrenamiento de Fuerza/métodos , Levantamiento de Peso/fisiología , Adulto , Ejercicio Físico , Humanos , Ácido Láctico/sangre , Masculino , Descanso/fisiología , Adulto Joven
11.
An Acad Bras Cienc ; 91(1): e20170856, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30994747

RESUMEN

We define a new lifetime model based on compounding the Lindley and Nadarajah-Haghighi distributions. The proposed distribution is very competitive to other lifetime models. Some of its mathematical properties are investigated including generating function, mean residual life, moments, Bonferroni and Lorenz curves and mean deviations. We discuss the estimation of the model parameters by maximum likelihood. We provide a simulation study and two applications to real data for illustrative purposes. We prove empirically that the new distribution yields good fits to both data sets, and it can be a useful alternative for other classical lifetime models.


Asunto(s)
Modelos Estadísticos , Análisis de Supervivencia , Algoritmos , Método de Montecarlo , Probabilidad , Estándares de Referencia , Reproducibilidad de los Resultados , Factores de Tiempo
12.
An Acad Bras Cienc ; 90(3): 2553-2577, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30304207

RESUMEN

We propose a new lifetime model called the exponentiated power generalized Weibull (EPGW) distribution, which is obtained from the exponentiated family applied to the power generalized Weibull (PGW) distribution. It can also be derived from a power transform on an exponentiated Nadarajah-Haghighi random variable. Since several structural properties of the PGW distribution have not been studied, they can be obtained from those of the EPGW distribution. The model is very flexible for modeling all common types of hazard rate functions. It is a very competitive model to the well-known Weibull, exponentiated exponential and exponentiated Weibull distributions, among others. We also give a physical motivation for the new distribution if the power parameter is an integer. Some of its mathematical properties are investigated. We discuss estimation of the model parameters by maximum likelihood and provide two applications to real data. A simulation study is performed in order to examine the accuracy of the maximum likelihood estimators of the model parameters.

13.
J Stroke Cerebrovasc Dis ; 27(9): 2453-2465, 2018 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-30029838

RESUMEN

INTRODUCTION: Stroke represents an attractive target for cell therapy. Although different types of cells have been employed in animal models with variable results, the human adipose-derived stem cells (hASCs) have demonstrated favorable characteristics in the treatment of diseases with inflammatory substrate, but experience in their intracerebral administration is lacking. The purpose of this study is to evaluate the effect and safety of the intracerebral application of hASCs in a stroke model. METHODS: A first group of Athymic Nude mice after stroke received a stereotactic injection of hASCs at a concentration of 4 × 104/µL at the penumbra area, a second group without stroke received the same cell concentration, and a third group had only stroke and no cells. After 7, 15, and 30 days, the animals underwent fluorodeoxyglucose-positron emission tomography and magnetic resonance imaging; subsequently, they were sacrificed for histological evaluation (HuNu, GFAP, IBA-1, Ki67, DCX) of the penumbra area and ipsilateral subventricular zone (iSVZ). RESULTS: The in vitro studies found no alterations in the molecular karyotype, clonogenic capacity, and expression of 62 kDa transcription factor and telomerase. Animals implanted with cells showed no adverse events. The implanted cells showed no evidence of proliferation or differentiation. However, there was an increase of capillaries, less astrocytes and microglia, and increased bromodeoxyuridine and doublecortin-positive cells in the iSVZ and in the vicinity of ischemic injury. CONCLUSIONS: These results suggest that hASCs in the implanted dose modulate inflammation, promote endogenous neurogenesis, and do not proliferate or migrate in the brain. These data confirm the safety of cell therapy with hASCs.


Asunto(s)
Isquemia Encefálica/terapia , Trasplante de Células Madre , Tejido Adiposo/citología , Animales , Encéfalo/irrigación sanguínea , Encéfalo/diagnóstico por imagen , Encéfalo/metabolismo , Encéfalo/patología , Isquemia Encefálica/diagnóstico por imagen , Isquemia Encefálica/metabolismo , Isquemia Encefálica/patología , Proliferación Celular , Modelos Animales de Enfermedad , Proteína Doblecortina , Gliosis/diagnóstico por imagen , Gliosis/metabolismo , Gliosis/patología , Gliosis/terapia , Humanos , Masculino , Ratones Desnudos , Microglía/metabolismo , Microglía/patología , Actividad Motora , Neovascularización Patológica/diagnóstico por imagen , Neovascularización Patológica/metabolismo , Neovascularización Patológica/patología , Neovascularización Patológica/terapia , Neuronas/metabolismo , Neuronas/patología , Distribución Aleatoria , Trasplante de Células Madre/efectos adversos , Células Madre/citología , Trasplante Heterólogo
14.
Ear Hear ; 38(1): e57-e68, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-27556522

RESUMEN

OBJECTIVES: The objectives of this study were to evaluate the effect of reimplanting a cochlear implant electrode in animal normal-hearing cochlea to propose measures that may prevent cochlear injury and, given its close phylogenetic proximity to humans, to evaluate the macaque as a model for electroacoustic stimulation. DESIGN: Simultaneous, bilateral surgical procedures in a group of 5 normal-hearing specimens (Macaca fascicularis) took place in a total of 10 ears. Periodic bilateral auditory testing (distortion product otoacoustic emissions and auditory brainstem evoked responses [ABR]) took place during a 6-month follow-up period. Subsequently, unilateral explantation and reimplantation was performed. Auditory follow-up continued up to 12 months, after which animals were sacrificed and both temporal bones extracted for histological analysis. RESULTS: Implantation and reimplantation surgeries were performed without complications in 9 of 10 cases. Full insertion depth was achieved at reimplantation in four of five ears. Auditory evaluation: Statistically significant differences between implanted and reimplanted were observed for the frequencies 2000 and 11,000 Hz, the remaining frequencies showed no differences for distortion product otoacoustic emission. Before the procedure, average thresholds with click-stimuli ABR of the five animals were 40 dB SPL (implanted group) and 40 dB SPL (reimplanted group). One week after first implantation, average thresholds were 55 dB SPL and 60 dB, respectively. After 12 months of follow-up, the average thresholds were 72.5 dB SPL (implanted group) and 65 dB SPL (reimplanted group). Hearing loss appeared during the first weeks after the first implantation and no deterioration was observed thereafter. Differences for ABR under click stimulus were not significant between the two ear groups. Similar results were observed with tone-burst ABR. A 15 dB shift was observed for the implanted group preoperatively versus 1-week post surgery and an additional 17.5 dB shift was seen after 12-month follow-up. For the reimplanted group, a 20 dB shift was observed within the first week post reimplantation surgery and an additional 5 dB after 6 months follow-up. Statistical analysis revealed significant differences between the implanted and reimplanted ear groups for frequencies 4000 Hz (p = 0.034), 12000 Hz (p = 0.031), and 16,000 Hz (p = 0.031). The histological analysis revealed that the electrode insertion was minimally traumatic for the cochlea, mainly indicating rupture of the basilar membrane in the transition area between the basal turn and the first cochlear turn only in Mf1 left ear. CONCLUSIONS: With application of minimally traumatic surgical techniques, it is possible to maintain high rates of hearing preservation after implantation and even after reimplantation. Partial impairment of auditory thresholds may occur during the first weeks after surgery, which remains stable. Considering the tonotopic distribution of the cochlea, we found a correlation between the histological lesions sites and the auditory findings, suggesting that a rupture of the basilar membrane may impact hearing levels. The macaque was observed to be a functionally and anatomically an excellent animal model for cochlear implantation.


Asunto(s)
Implantación Coclear/métodos , Implantes Cocleares , Remoción de Dispositivos , Pérdida Auditiva/fisiopatología , Animales , Cóclea/lesiones , Electrodos Implantados , Potenciales Evocados Auditivos del Tronco Encefálico , Macaca fascicularis , Emisiones Otoacústicas Espontáneas , Reoperación/métodos
15.
Clin Anat ; 29(4): 481-92, 2016 May.
Artículo en Inglés | MEDLINE | ID: mdl-26779936

RESUMEN

The cortico-basal ganglia and corticothalamic projections have been extensively studied in the context of neurological and psychiatric disorders. Deep brain stimulation (DBS) is known to modulate many of these pathways to produce the desired clinical effect. The aim of this work is to describe the anatomy of the main circuits of the basal ganglia using tractography in a surgical planning station. We used imaging studies of 20 patients who underwent DBS for movement and psychiatric disorders. We segmented the putamen, caudate nucleus (CN), thalamus, and subthalamic nucleus (STN), and we also segmented the cortical areas connected with these subcortical areas. We used tractography to define the subdivisions of the basal ganglia and thalamus through the generation of fibers from the cortical areas to the subcortical structures. We were able to generate the corticostriatal and corticothalamic connections involved in the motor, associative and limbic circuits. Furthermore, we were able to reconstruct the hyperdirect pathway through the corticosubthalamic connections and we found subregions in the STN. Finally, we reconstructed the cortico-subcortical connections of the ventral intermediate nucleus, the nucleus accumbens and the CN. We identified a feasible delineation of the basal ganglia and thalamus connections using tractography. These results could be potentially useful in DBS if the parcellations are used as targets during surgery.


Asunto(s)
Ganglios Basales/anatomía & histología , Corteza Cerebral/anatomía & histología , Estimulación Encefálica Profunda/métodos , Modelos Anatómicos , Tálamo/fisiología , Corteza Cerebral/diagnóstico por imagen , Imagen de Difusión Tensora , Femenino , Humanos , Imagenología Tridimensional , Imagen por Resonancia Magnética , Masculino , Trastornos Mentales/patología , Persona de Mediana Edad , Trastornos del Movimiento/patología , Estudios Retrospectivos
16.
Neurocirugia (Astur) ; 27(6): 296-303, 2016.
Artículo en Español | MEDLINE | ID: mdl-27091228

RESUMEN

Erdheim-Chester disease is a non-Langerhans histiocytosis. Until 2014 at least 550 cases have been reported. According to European Rare Disease Organization and National Organization for Rare Disorders it is a rare disease. The most common symptom is bone pain in the lower extremities and it usually appears between the 5th and 7th decades of life. The diagnostic is based on immunohistochemical results: S100(+/-), CD68(+), and CD1a(-), the latter 2 are mandatory. The best treatment nowadays is alpha-interferon or pegylated alpha-2. The overall survival is 96% at one year and 68% at 5 years. Central nervous system involvement is associated with a worse outcome. Two cases are presentedwith central nervous system lesions in the absence of lesions in other organs on their onset. Very few cases have been reported with this kind of presentation. We also noted that these patients had recurrences or new lesions at 8 months. A follow-up is proposed with brain MRI and thoraco-abdominal PET every 3-4 months.


Asunto(s)
Enfermedad de Erdheim-Chester/diagnóstico , Preescolar , Enfermedad de Erdheim-Chester/complicaciones , Humanos , Imagen por Resonancia Magnética , Dolor/etiología
17.
J Neurosci ; 34(36): 12155-67, 2014 Sep 03.
Artículo en Inglés | MEDLINE | ID: mdl-25186759

RESUMEN

Humans recognize faces and objects with high speed and accuracy regardless of their orientation. Recent studies have proposed that orientation invariance in face recognition involves an intermediate representation where neural responses are similar for mirror-symmetric views. Here, we used fMRI, multivariate pattern analysis, and computational modeling to investigate the neural encoding of faces and vehicles at different rotational angles. Corroborating previous studies, we demonstrate a representation of face orientation in the fusiform face-selective area (FFA). We go beyond these studies by showing that this representation is category-selective and tolerant to retinal translation. Critically, by controlling for low-level confounds, we found the representation of orientation in FFA to be compatible with a linear angle code. Aspects of mirror-symmetric coding cannot be ruled out when FFA mean activity levels are considered as a dimension of coding. Finally, we used a parametric family of computational models, involving a biased sampling of view-tuned neuronal clusters, to compare different face angle encoding models. The best fitting model exhibited a predominance of neuronal clusters tuned to frontal views of faces. In sum, our findings suggest a category-selective and monotonic code of face orientation in the human FFA, in line with primate electrophysiology studies that observed mirror-symmetric tuning of neural responses at higher stages of the visual system, beyond the putative homolog of human FFA.


Asunto(s)
Cara/anatomía & histología , Modelos Neurológicos , Reconocimiento Visual de Modelos , Rotación , Corteza Visual/fisiología , Adulto , Femenino , Humanos , Masculino , Vehículos a Motor
18.
Neuroimage ; 121: 193-204, 2015 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-26162550

RESUMEN

It is a principal open question whether noninvasive imaging methods in humans can decode information encoded at a spatial scale as fine as the basic functional unit of cortex: cortical columns. We addressed this question in five magnetoencephalography (MEG) experiments by investigating a columnar-level encoded visual feature: contrast edge orientation. We found that MEG signals contained orientation-specific information as early as approximately 50 ms after stimulus onset even when controlling for confounds, such as overrepresentation of particular orientations, stimulus edge interactions, and global form-related signals. Theoretical modeling confirmed the plausibility of this empirical result. An essential consequence of our results is that information encoded in the human brain at the level of cortical columns should in general be accessible by multivariate analysis of electrophysiological signals.


Asunto(s)
Corteza Cerebral/fisiología , Magnetoencefalografía/métodos , Reconocimiento Visual de Modelos/fisiología , Adulto , Estudios de Factibilidad , Femenino , Humanos , Masculino , Adulto Joven
19.
Langmuir ; 31(4): 1400-9, 2015 Feb 03.
Artículo en Inglés | MEDLINE | ID: mdl-25558765

RESUMEN

This work includes both experimental and theoretical studies of the wetting property changes of water on a surface of poly(dimethylsiloxane) (PDMS) modified with different amounts of acrylic acid (AA). The default surface properties of PDMS were changed from hydrophobic to hydrophilic behavior which was characterized with contact angle measurements by two approaches: (i) experimental tests of samples subjected to a photografting polymerization procedure to obtain a functionalized surface and (ii) DPD (dissipative particle dynamics) simulations which also involve the calculation of sets of repulsive parameters determined following two methods: the use of the "Blends" module in the Materials Studio software and the calculation of cohesive energy density with molecular simulations. Changes of contact angle values observed from both experimental and numerical simulation results provide qualitative and quantitative information on the wetting behavior of photografted surfaces.

20.
Med Sci Monit ; 21: 1745-51, 2015 Jun 16.
Artículo en Inglés | MEDLINE | ID: mdl-26079849

RESUMEN

BACKGROUND: Cancer development involves an "injury" to the respiratory machinery (Warburg effect) due to decreased or impaired mitochondrial function. This circumstance results in a down regulation of some of the ATPase subunits of the malignant tissue. The objective of this work was to assess and compare the relative expression of mRNA of mitochondrial ATPase subunits between samples of thyroid cancer and benign nodules. MATERIAL AND METHODS: Samples from 31 patients who had an operation for PTC at the General Hospital of Mexico were snap-frozen and stored at -70°C. Thirty-five patients who had an operation for benign tumors were also included in the study. mRNA expression levels of alpha, beta, gamma, and epsilon subunits of F1 and "c12" of subunit Fo were determined by real-time RT-PCR (by duplicate), in order to determine if abnormal expression of these genes could partially explain the Warburg effect in papillary thyroid cancer (PTC). RESULTS: ATP5E transcript alteration (down-expression) was highly associated to PTC diagnosis OR=11.76 (95% confidence interval, 1.245-237.98; p=0.04). CONCLUSIONS: Relative down-expression of ATP5E transcript was highly associated with PTC diagnosis. This transcript alteration may be used as a tumoral marker in papillary thyroid cancer.


Asunto(s)
Carcinoma/enzimología , Carcinoma/genética , ATPasas de Translocación de Protón Mitocondriales/genética , Proteínas/genética , ARN Mensajero/genética , Neoplasias de la Tiroides/enzimología , Neoplasias de la Tiroides/genética , Adolescente , Adulto , Anciano , Biomarcadores de Tumor/biosíntesis , Biomarcadores de Tumor/genética , Carcinoma/patología , Carcinoma Papilar , Regulación hacia Abajo , Femenino , Expresión Génica , Humanos , Masculino , Persona de Mediana Edad , ATPasas de Translocación de Protón Mitocondriales/biosíntesis , Estudios Prospectivos , Proteínas/metabolismo , ARN Mensajero/metabolismo , Cáncer Papilar Tiroideo , Neoplasias de la Tiroides/patología , Adulto Joven , Proteína Inhibidora ATPasa
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