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3.
J Vet Intern Med ; 2022 Mar 23.
Artículo en Inglés | MEDLINE | ID: mdl-35319111

RESUMEN

BACKGROUND: Limited data exist on the diagnosis and successful medical management of suspected pancreatic abscessation, and the appropriate terminology of this condition. HYPOTHESIS/OBJECTIVES: To describe the diagnosis and management of pancreatic fluid accumulations in dogs where pancreatic fluid cytology results were available, to describe those medically and surgically managed at the same institution, and reconsider the terminology describing acute pancreatitis with pancreatic fluid accumulation. ANIMALS: Fifteen dogs treated for suspected pancreatic abscessation at a university teaching hospital between January 2010 and March 2020. METHODS: Retrospective descriptive study. RESULTS: Ultrasonographic findings described pancreatic fluid accumulations as hypoechoic in 10/15 and anechoic in 2/15 cases, ranging between 1.6 and 7 cm in diameter (median, 3.5 cm). No complications were documented after ultrasound guided fine-needle aspiration. Cytologically, all samples revealed a predominantly neutrophilic inflammation. 11/15 samples yielded a negative culture (9/11 received antimicrobials before sampling) and in 4 cases culture was positive. 7/15 were initially managed surgically including all 4 infected cases. 4/7 surgically managed cases were discharged, including 2 infected cases. The remaining 3/7 surgically managed cases were euthanized due poor quality of life. 8/15 cases were managed medically; 7/8 were discharged, 1 died. 3/7 then represented, and underwent successful surgical intervention after recrudescence of clinical signs, and all were discharged. The remaining 4 medically managed cases did not require further therapeutic intervention, with no clinical deterioration on reassessment. CONCLUSIONS AND CLINICAL IMPORTANCE: Medical management is a viable treatment option for some dogs with pancreatic fluid accumulation, or as a prequel to surgical management. Subclassifications of pancreatic fluid accumulations using diagnostic findings could enable more tailored management approaches and accurate prognostication.

5.
J Neurooncol ; 156(2): 353-363, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34997451

RESUMEN

INTRODUCTION: Recurrent glioblastoma (rGBM) prognosis is dismal. In the absence of effective adjuvant treatments for rGBM, re-resections remain prominent in our arsenal. This study evaluates the impact of reoperation on post-progression survival (PPS) considering rGBM genetic makeup. METHODS: To assess the genetic heterogeneity and treatment-related changes (TRC) roles in re-operated or medically managed rGBMs, we compiled demographic, clinical, histopathological, and next-generation genetic sequencing (NGS) characteristics of these tumors from 01/2005 to 10/2019. Survival data and reoperation were analyzed using conventional and random survival forest analysis (RSF). RESULTS: Patients harboring CDKN2A/B loss (p = 0.017) and KDR mutations (p = 0.031) had notably shorter survival. Reoperation or bevacizumab were associated with longer PPS (11.2 vs. 7.4-months, p = 0.006; 13.1 vs 6.2, p < 0.001). Reoperated patients were younger, had better performance status and greater initial resection. In 136/273 (49%) rGBMs undergoing re-operation, CDKN2A/B loss (p = 0.03) and KDR mutations (p = 0.02) were associated with shorter survival. In IDH-WT rGBMs with NGS data (n = 166), reoperation resulted in 7.0-month longer survival (p = 0.004) than those managed medically. This reoperation benefit was independently identified by RSF analysis. Stratification analysis revealed that EGFR-mutant, CDKN2A/B-mutant, NF1-WT, and TP53-WT rGBM IDH-WT subgroups benefit most from reoperation (p = 0.03). Lastly, whether or not TRC was prominent at re-operation does not have any significant impact on PPS (10.5 vs. 11.5-months, p = 0.77). CONCLUSIONS: Maximal safe re-resection significantly lengthens PPS regardless of genetic makeup, but reoperations are especially beneficial for IDH-WT rGBMs with EGFR and CDKN2A/B mutations with TP53-WT, and NF1-WT. Histopathology at recurrence may be an imperfect gauge of disease severity at progression and the imaging progression may be more reflective of the prognosis.


Asunto(s)
Neoplasias Encefálicas , Glioblastoma , Recurrencia Local de Neoplasia , Reoperación , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patología , Neoplasias Encefálicas/cirugía , Receptores ErbB/genética , Variación Genética , Glioblastoma/genética , Glioblastoma/patología , Glioblastoma/cirugía , Humanos , Recurrencia Local de Neoplasia/genética , Recurrencia Local de Neoplasia/cirugía , Pronóstico , Análisis de Supervivencia
6.
Neurosci Biobehav Rev ; 131: 1288-1304, 2021 12.
Artículo en Inglés | MEDLINE | ID: mdl-34687699

RESUMEN

In this paper, we introduce a new generative model for an active inference account of preparatory and selective attention, in the context of a classic 'cocktail party' paradigm. In this setup, pairs of words are presented simultaneously to the left and right ears and an instructive spatial cue directs attention to the left or right. We use this generative model to test competing hypotheses about the way that human listeners direct preparatory and selective attention. We show that assigning low precision to words at attended-relative to unattended-locations can explain why a listener reports words from a competing sentence. Under this model, temporal changes in sensory precision were not needed to account for faster reaction times with longer cue-target intervals, but were necessary to explain ramping effects on event-related potentials (ERPs)-resembling the contingent negative variation (CNV)-during the preparatory interval. These simulations reveal that different processes are likely to underlie the improvement in reaction times and the ramping of ERPs that are associated with spatial cueing.


Asunto(s)
Percepción del Habla , Señales (Psicología) , Electroencefalografía , Potenciales Evocados , Humanos , Tiempo de Reacción
7.
Hum Brain Mapp ; 42(17): 5595-5608, 2021 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-34459062

RESUMEN

When listening to music, pitch deviations are more salient and elicit stronger prediction error responses when the melodic context is predictable and when the listener is a musician. Yet, the neuronal dynamics and changes in connectivity underlying such effects remain unclear. Here, we employed dynamic causal modeling (DCM) to investigate whether the magnetic mismatch negativity response (MMNm)-and its modulation by context predictability and musical expertise-are associated with enhanced neural gain of auditory areas, as a plausible mechanism for encoding precision-weighted prediction errors. Using Bayesian model comparison, we asked whether models with intrinsic connections within primary auditory cortex (A1) and superior temporal gyrus (STG)-typically related to gain control-or extrinsic connections between A1 and STG-typically related to propagation of prediction and error signals-better explained magnetoencephalography responses. We found that, compared to regular sounds, out-of-tune pitch deviations were associated with lower intrinsic (inhibitory) connectivity in A1 and STG, and lower backward (inhibitory) connectivity from STG to A1, consistent with disinhibition and enhanced neural gain in these auditory areas. More predictable melodies were associated with disinhibition in right A1, while musicianship was associated with disinhibition in left A1 and reduced connectivity from STG to left A1. These results indicate that musicianship and melodic predictability, as well as pitch deviations themselves, enhance neural gain in auditory cortex during deviance detection. Our findings are consistent with predictive processing theories suggesting that precise and informative error signals are selected by the brain for subsequent hierarchical processing.


Asunto(s)
Corteza Auditiva/fisiología , Neuroimagen Funcional , Magnetoencefalografía , Música , Percepción de la Altura Tonal/fisiología , Adulto , Teorema de Bayes , Femenino , Humanos , Masculino , Modelos Teóricos , Adulto Joven
9.
Psychol Sci ; 32(6): 903-915, 2021 06.
Artículo en Inglés | MEDLINE | ID: mdl-33979256

RESUMEN

When people listen to speech in noisy places, they can understand more words spoken by someone familiar, such as a friend or partner, than someone unfamiliar. Yet we know little about how voice familiarity develops over time. We exposed participants (N = 50) to three voices for different lengths of time (speaking 88, 166, or 478 sentences during familiarization and training). These previously heard voices were recognizable and more intelligible when presented with a competing talker than novel voices-even the voice previously heard for the shortest duration. However, recognition and intelligibility improved at different rates with longer exposures. Whereas recognition was similar for all previously heard voices, intelligibility was best for the voice that had been heard most extensively. The speech-intelligibility benefit for the most extensively heard voice (10%-15%) is as large as that reported for voices that are naturally very familiar (friends and spouses)-demonstrating that the intelligibility of a voice can be improved substantially after only an hour of training.


Asunto(s)
Percepción del Habla , Voz , Humanos , Inteligibilidad del Habla , Reconocimiento de Voz , Entrenamiento de la Voz
10.
Neuroimage ; 237: 118107, 2021 08 15.
Artículo en Inglés | MEDLINE | ID: mdl-33933598

RESUMEN

When speech is masked by competing sound, people are better at understanding what is said if the talker is familiar compared to unfamiliar. The benefit is robust, but how does processing of familiar voices facilitate intelligibility? We combined high-resolution fMRI with representational similarity analysis to quantify the difference in distributed activity between clear and masked speech. We demonstrate that brain representations of spoken sentences are less affected by a competing sentence when they are spoken by a friend or partner than by someone unfamiliar-effectively, showing a cortical signal-to-noise ratio (SNR) enhancement for familiar voices. This effect correlated with the familiar-voice intelligibility benefit. We functionally parcellated auditory cortex, and found that the most prominent familiar-voice advantage was manifest along the posterior superior and middle temporal gyri. Overall, our results demonstrate that experience-driven improvements in intelligibility are associated with enhanced multivariate pattern activity in posterior temporal cortex.


Asunto(s)
Neuroimagen Funcional , Reconocimiento en Psicología/fisiología , Percepción Social , Inteligibilidad del Habla/fisiología , Percepción del Habla/fisiología , Lóbulo Temporal/fisiología , Adulto , Anciano , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Voz , Adulto Joven
11.
Sci Rep ; 11(1): 7475, 2021 04 02.
Artículo en Inglés | MEDLINE | ID: mdl-33811259

RESUMEN

Functional recovery after brain damage varies widely and depends on many factors, including lesion site and extent. When a neuronal system is damaged, recovery may occur by engaging residual (e.g., perilesional) components. When damage is extensive, recovery depends on the availability of other intact neural structures that can reproduce the same functional output (i.e., degeneracy). A system's response to damage may occur rapidly, require learning or both. Here, we simulate functional recovery from four different types of lesions, using a generative model of word repetition that comprised a default premorbid system and a less used alternative system. The synthetic lesions (i) completely disengaged the premorbid system, leaving the alternative system intact, (ii) partially damaged both premorbid and alternative systems, and (iii) limited the experience-dependent plasticity of both. The results, across 1000 trials, demonstrate that (i) a complete disconnection of the premorbid system naturally invoked the engagement of the other, (ii) incomplete damage to both systems had a much more devastating long-term effect on model performance and (iii) the effect of reducing learning capacity within each system. These findings contribute to formal frameworks for interpreting the effect of different types of lesions.


Asunto(s)
Encéfalo/patología , Encéfalo/fisiopatología , Simulación por Computador , Recuperación de la Función/fisiología , Potenciales de Acción , Conducta , Humanos , Modelos Biológicos , Plasticidad Neuronal/fisiología
12.
Vet Clin Pathol ; 50(1): 52-56, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33655523

RESUMEN

BACKGROUND: Gray eosinophils, resembling those in sighthound dog breeds, have not previously been reported in cats. OBJECTIVES: We aimed to provide a morphologic, cytochemical, and ultrastructural description of gray eosinophils in cats. METHODS: Blood films examined as part of routine hematology profiles in cats from May 2015 to July 2018 were evaluated for the presence of gray eosinophils. When identified with modified Wright stain, cells were morphologically assessed and additionally stained with Diff-Quik, ALP, Luna, and Luxol fast blue stains and compared with feline controls. Two cases were prepared for transmission electron microscopy (TEM) and compared with a feline control. RESULTS: Gray eosinophils were identified in 9 of 2641 cats during the study period. Compared with typical feline eosinophils, these cells contained abundant round granules instead of the characteristic rod-shaped specific granules. These granules lacked the characteristic intense pink/red staining with Romanowsky stains and did not stain with ALP, Luna, or Luxol fast blue stains. On TEM, the classical electron-dense core of these granules was replaced by a core with fragmented or amorphous internal material. Typical eosinophils were not identified in any cat in which gray eosinophils were identified. CONCLUSIONS: The distinct morphologic, cytochemical, and ultrastructural changes in gray feline eosinophils might be associated with a reduction or lack of major basic protein (MBP) in specific granule cores. Similar to canine gray eosinophils, accurate recognition of these cells is essential to prevent their misclassification as toxic neutrophils.


Asunto(s)
Colorantes , Eosinófilos , Animales , Gatos , Perros , Recuento de Leucocitos/veterinaria , Microscopía Electrónica de Transmisión/veterinaria , Coloración y Etiquetado/veterinaria
13.
Hear Res ; 399: 107998, 2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-32732017

RESUMEN

This paper introduces active listening, as a unified framework for synthesising and recognising speech. The notion of active listening inherits from active inference, which considers perception and action under one universal imperative: to maximise the evidence for our (generative) models of the world. First, we describe a generative model of spoken words that simulates (i) how discrete lexical, prosodic, and speaker attributes give rise to continuous acoustic signals; and conversely (ii) how continuous acoustic signals are recognised as words. The 'active' aspect involves (covertly) segmenting spoken sentences and borrows ideas from active vision. It casts speech segmentation as the selection of internal actions, corresponding to the placement of word boundaries. Practically, word boundaries are selected that maximise the evidence for an internal model of how individual words are generated. We establish face validity by simulating speech recognition and showing how the inferred content of a sentence depends on prior beliefs and background noise. Finally, we consider predictive validity by associating neuronal or physiological responses, such as the mismatch negativity and P300, with belief updating under active listening, which is greatest in the absence of accurate prior beliefs about what will be heard next.


Asunto(s)
Audición , Lenguaje , Ruido/efectos adversos , Percepción del Habla
14.
Cereb Cortex ; 31(3): 1582-1596, 2021 02 05.
Artículo en Inglés | MEDLINE | ID: mdl-33136138

RESUMEN

In our everyday lives, we are often required to follow a conversation when background noise is present ("speech-in-noise" [SPIN] perception). SPIN perception varies widely-and people who are worse at SPIN perception are also worse at fundamental auditory grouping, as assessed by figure-ground tasks. Here, we examined the cortical processes that link difficulties with SPIN perception to difficulties with figure-ground perception using functional magnetic resonance imaging. We found strong evidence that the earliest stages of the auditory cortical hierarchy (left core and belt areas) are similarly disinhibited when SPIN and figure-ground tasks are more difficult (i.e., at target-to-masker ratios corresponding to 60% rather than 90% performance)-consistent with increased cortical gain at lower levels of the auditory hierarchy. Overall, our results reveal a common neural substrate for these basic (figure-ground) and naturally relevant (SPIN) tasks-which provides a common computational basis for the link between SPIN perception and fundamental auditory grouping.


Asunto(s)
Corteza Auditiva/fisiología , Enmascaramiento Perceptual/fisiología , Percepción del Habla/fisiología , Adulto , Atención/fisiología , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Ruido
15.
Cortex ; 135: 92-107, 2021 02.
Artículo en Inglés | MEDLINE | ID: mdl-33360763

RESUMEN

We investigated auditory processing in a young patient who experienced a single embolus causing an infarct in the right middle cerebral artery territory. This led to damage to auditory cortex including planum temporale that spared medial Heschl's gyrus, and included damage to the posterior insula and inferior parietal lobule. She reported chronic difficulties with segregating speech from noise and segregating elements of music. Clinical tests showed no evidence for abnormal cochlear function. Follow-up tests confirmed difficulties with auditory segregation in her left ear that spanned multiple domains, including words-in-noise and music streaming. Testing with a stochastic figure-ground task-a way of estimating generic acoustic foreground and background segregation-demonstrated that this was also abnormal. This is the first demonstration of an acquired deficit in the segregation of complex acoustic patterns due to cortical damage, which we argue is a causal explanation for the symptomatic deficits in the segregation of speech and music. These symptoms are analogous to the visual symptom of simultaneous agnosia. Consistent with functional imaging studies on normal listeners, the work implicates non-primary auditory cortex. Further, the work demonstrates a (partial) lateralisation of the necessary anatomical substrate for segregation that has not been previously highlighted.


Asunto(s)
Agnosia , Corteza Auditiva , Percepción Auditiva , Femenino , Humanos , Imagen por Resonancia Magnética , Habla
16.
Andrologia ; 52(11): e13859, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-33026690

RESUMEN

Human ejaculates collected for in vitro procedures show variably rapid increases in osmolality, depending on enzymatic degradation of compounds. Changes in osmolality can affect cell functions due to the energy consuming processes needed to control cell volume. The aim was to examine the effects of a hypotonic challenge for spermatozoa exposed to increased osmolality. Spermatozoa were selected by density gradient centrifugation and washed in media with different osmolalities. Osmolality was measured by freezing-point depression and sperm velocities by CASA. Swimming pattern observations and assessments of tail morphology of fixed spermatozoa were done with phase contrast microscopy. Increased osmolality did not change the curvilinear velocity (VCL), while decreased osmolality reduced or abolished VCL nonreversibly. For spermatozoa first exposed to 400 mOsm/kg, reversal of osmolality to 290 mOsm/kg reduced the VCL and the average path velocity (VAP) permanently. Hypotonic challenges increased sperm tail coiling and folding in a dose-response pattern. Spermatozoa once adjusted to high osmolality in the liquefied ejaculate are likely to suffer if exposed to a medium with a lower osmolality. For improved success of Assisted Reproductive Technologies (ART), it appears to be important to minimise the duration of sperm exposure to the ejaculate, by early dilution or sperm preparation.


Asunto(s)
Motilidad Espermática , Espermatozoides , Humanos , Masculino , Concentración Osmolar , Cola del Espermatozoide
17.
Neuron ; 108(3): 401-412, 2020 11 11.
Artículo en Inglés | MEDLINE | ID: mdl-32871106

RESUMEN

Epidemiological studies identify midlife hearing loss as an independent risk factor for dementia, estimated to account for 9% of cases. We evaluate candidate brain bases for this relationship. These bases include a common pathology affecting the ascending auditory pathway and multimodal cortex, depletion of cognitive reserve due to an impoverished listening environment, and the occupation of cognitive resources when listening in difficult conditions. We also put forward an alternate mechanism, drawing on new insights into the role of the medial temporal lobe in auditory cognition. In particular, we consider how aberrant activity in the service of auditory pattern analysis, working memory, and object processing may interact with dementia pathology in people with hearing loss. We highlight how the effect of hearing interventions on dementia depends on the specific mechanism and suggest avenues for work at the molecular, neuronal, and systems levels to pin this down.


Asunto(s)
Encéfalo/fisiopatología , Demencia/etiología , Demencia/fisiopatología , Pérdida Auditiva/complicaciones , Pérdida Auditiva/fisiopatología , Percepción Auditiva/fisiología , Humanos
18.
Sci Rep ; 10(1): 13997, 2020 08 19.
Artículo en Inglés | MEDLINE | ID: mdl-32814792

RESUMEN

Speech-in-noise (SiN) perception is a critical aspect of natural listening, deficits in which are a major contributor to the hearing handicap in cochlear hearing loss. Studies suggest that SiN perception correlates with cognitive skills, particularly phonological working memory: the ability to hold and manipulate phonemes or words in mind. We consider here the idea that SiN perception is linked to a more general ability to hold sound objects in mind, auditory working memory, irrespective of whether the objects are speech sounds. This process might help combine foreground elements, like speech, over seconds to aid their separation from the background of an auditory scene. We investigated the relationship between auditory working memory precision and SiN thresholds in listeners with normal hearing. We used a novel paradigm that tests auditory working memory for non-speech sounds that vary in frequency and amplitude modulation (AM) rate. The paradigm yields measures of precision in frequency and AM domains, based on the distribution of participants' estimates of the target. Across participants, frequency precision correlated significantly with SiN thresholds. Frequency precision also correlated with the number of years of musical training. Measures of phonological working memory did not correlate with SiN detection ability. Our results demonstrate a specific relationship between working memory for frequency and SiN. We suggest that working memory for frequency facilitates the identification and tracking of foreground objects like speech during natural listening. Working memory performance for frequency also correlated with years of musical instrument experience suggesting that the former is potentially modifiable.


Asunto(s)
Pérdida Auditiva Sensorineural/fisiopatología , Audición/fisiología , Memoria a Corto Plazo/fisiología , Percepción del Habla/fisiología , Habla/fisiología , Adolescente , Adulto , Audiometría de Tonos Puros/métodos , Cognición/fisiología , Femenino , Pérdida Auditiva Sensorineural/diagnóstico , Humanos , Masculino , Persona de Mediana Edad , Ruido , Relación Señal-Ruido , Prueba del Umbral de Recepción del Habla/métodos , Adulto Joven
19.
Neurosci Biobehav Rev ; 118: 42-64, 2020 11.
Artículo en Inglés | MEDLINE | ID: mdl-32687883

RESUMEN

This paper presents a biologically plausible generative model and inference scheme that is capable of simulating communication between synthetic subjects who talk to each other. Building on active inference formulations of dyadic interactions, we simulate linguistic exchange to explore generative models that support dialogues. These models employ high-order interactions among abstract (discrete) states in deep (hierarchical) models. The sequential nature of language processing mandates generative models with a particular factorial structure-necessary to accommodate the rich combinatorics of language. We illustrate linguistic communication by simulating a synthetic subject who can play the 'Twenty Questions' game. In this game, synthetic subjects take the role of the questioner or answerer, using the same generative model. This simulation setup is used to illustrate some key architectural points and demonstrate that many behavioural and neurophysiological correlates of linguistic communication emerge under variational (marginal) message passing, given the right kind of generative model. For example, we show that theta-gamma coupling is an emergent property of belief updating, when listening to another.


Asunto(s)
Comunicación , Lenguaje , Percepción Auditiva , Simulación por Computador , Humanos , Lingüística
20.
J Exp Psychol Learn Mem Cogn ; 46(8): 1465-1476, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-32105143

RESUMEN

Understanding speech in adverse conditions is affected by experience-a familiar voice is substantially more intelligible than an unfamiliar voice when competing speech is present, even if the content of the speech (the words) are controlled. This familiar-voice benefit is observed consistently, but its underpinnings are unclear: Do familiar voices simply attract more attention, are they inherently more intelligible because they have predictable acoustic characteristics, or are they more intelligible in a mixture because they are more resistant to interference from other sounds? We recruited pairs of native English-speaking participants who were friends or romantic couples. Participants reported words from closed-set English sentences (i.e., Oldenburg Matrix Test; Zokoll et al., 2013) spoken by a familiar talker (the participant's partner) or an unfamiliar talker. We compared 3 masker conditions that are acoustically similar but differ in their demands: (1) English Oldenburg sentences; (2) Oldenburg sentences in a language incomprehensible to the listener (Russian or Spanish); and (3) unintelligible signal-correlated noise. We adaptively varied the target-to-masker ratio to obtain 50% speech reception thresholds. We observed a large (∼5 dB) familiar-voice benefit when the target and masker were both English sentences. This benefit was attenuated (to ∼2 dB) when the masker was in an incomprehensible language and disappeared when it was signal-correlated noise. These results suggest that familiar voices did not benefit intelligibility because they were more predictable or because they attracted greater attention, rather familiarity with a target voice reduced interference from maskers that are linguistically similar to the target. (PsycInfo Database Record (c) 2020 APA, all rights reserved).


Asunto(s)
Atención/fisiología , Reconocimiento en Psicología/fisiología , Percepción Social , Percepción del Habla/fisiología , Adulto , Femenino , Amigos , Humanos , Masculino , Enmascaramiento Perceptual/fisiología , Parejas Sexuales , Inteligibilidad del Habla/fisiología , Adulto Joven
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