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1.
J Reconstr Microsurg ; 39(1): 70-80, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-35764300

RESUMO

BACKGROUND: Microvascular hepatic artery reconstruction (MHAR) is associated with decreased rates of hepatic artery thrombosis (HAT) in living donor liver transplantation (LDLT). There is a paucity of literature describing the learning points and initiation of this technique at the institutional level. The objective of this study is to report our institutional experience using MHAR in adult LDLT with a focus on technique and outcomes. METHODS: A retrospective review of adult patients who underwent LDLT from January 2012 to December 2020 was conducted. Patients were divided into two groups, those who underwent LDLT without MHAR and with MHAR. We analyzed cases for technical data including donor and recipient artery characteristics, anastomotic techniques, intraop events, and postop complications. A Mann-Whitney test was performed to compare outcomes between non-MHAR and MHAR patients. RESULTS: Fifty non-MHAR and 50 MHAR patients met inclusion criteria. Median age at transplantation was 58 (interquartile range [IQR] 11.8) and 57.5 years (IQR 14.5), respectively. Median follow-up for MHAR patients was 12.8 months (IQR 11.6). The most common recipient arteries were the right hepatic artery (HA) (58%) and left HA (20%). Median size of recipient and donor arteries were 3.3 mm (IQR 0.7) and 3.1 mm (IQR 0.7), resulting in a median mismatch size of 0.3 mm (IQR 0.4). Median microanastomosis time was 44 minutes (IQR 0). HAT, graft failure, and mortality rates were higher in the non-MHAR cohort (6% vs. 0%, 8% vs. 0%, and 16% vs. 6%, respectively); however, these did not reach statistical significance. CONCLUSION: This study found lower rates of HAT and graft failure after implementing MHAR, though statistical significance was not achieved. Larger cohort studies are needed to further assess the potential benefit of MHAR in adult LDLT. From our experience, MHAR requires cooperation between the transplant and microsurgical teams, with technical challenges overcome with appropriate instrumentation and planning.


Assuntos
Transplante de Fígado , Trombose , Humanos , Adulto , Criança , Transplante de Fígado/efeitos adversos , Transplante de Fígado/métodos , Doadores Vivos , Resultado do Tratamento , Artéria Hepática/cirurgia , Trombose/etiologia , Estudos Retrospectivos , Anastomose Cirúrgica/efeitos adversos
2.
J Surg Oncol ; 126(2): 217-238, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35389520

RESUMO

Cutaneous metastases (CM) are neoplastic lesions involving the dermis or subcutaneous tissues, originating from another primary tumor. Breast cancer is commonest primary solid tumor, representing 24%-50% of CM patients. There is no "standard of care" on management. In particular, the role of surgery in the treatment of cutaneous metastases from breast carcinoma (CMBC) remains controversial. This systematic review evaluates the role of cutaneous metastasectomy in breast cancer and provides an overview of existing treatment types.


Assuntos
Neoplasias da Mama , Neoplasias Pulmonares , Metastasectomia , Neoplasias Cutâneas , Neoplasias da Mama/patologia , Neoplasias da Mama/cirurgia , Feminino , Humanos , Neoplasias Pulmonares/cirurgia
3.
Can J Psychiatry ; 67(10): 745-754, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35522196

RESUMO

OBJECTIVES: To determine the efficacy and safety of blue-light therapy in seasonal and non-seasonal major depressive disorder (MDD), by comparison to active and inactive control conditions. METHODS: We searched Web of Science, EMBASE, Medline, PsycInfo, and Clinicaltrials.gov through January 17, 2022, for randomized controlled trials (RCTs) using search terms for blue/blue-enhanced, light therapy, and depression/seasonal affective disorder. Two independent reviewers extracted data. The primary outcome was the difference in endpoint scores on the Structured Interview Guide for the Hamilton Depression Rating Scale - Seasonal Affective Disorder (SIGH-SAD) or the Structured Interview Guide for the Hamilton Depression Rating Scale with Atypical Depression Supplement (SIGH-ADS) between blue light and comparison conditions. Secondary outcomes were response (≥ 50% improvement from baseline to endpoint on a depression scale) and remission rates (endpoint score in the remission range). RESULTS: Of 582 articles retrieved, we included nine RCTs (n = 347 participants) assessing blue-light therapy. Seven studies had participants with seasonal MDD and two studies included participants with non-seasonal MDD. Four studies compared blue light to an inactive light condition (efficacy studies), and five studies compared it to an active condition (comparison studies). For the primary outcome, a meta-analysis with random-effects models found no evidence for the efficacy of blue-light conditions compared to inactive conditions (mean difference [MD] = 2.43; 95% confidence interval [CI], -1.28 to 6.14, P = 0.20); however, blue-light also showed no differences compared to active conditions (MD = -0.11; 95% CI, -2.38 to 2.16, P = 0.93). There were no significant differences in response and remission rates between blue-light conditions and inactive or active light conditions. Blue-light therapy was overall well-tolerated. CONCLUSIONS: The efficacy of blue-light therapy in the treatment of seasonal and non-seasonal MDD remains unproven. Future trials should be of longer duration, include larger sample sizes, and attempt to better standardize the parameters of light therapy.


Assuntos
Transtorno Depressivo Maior , Transtorno Afetivo Sazonal , Depressão , Transtorno Depressivo Maior/terapia , Humanos , Fototerapia , Ensaios Clínicos Controlados Aleatórios como Assunto , Transtorno Afetivo Sazonal/terapia
4.
J Community Health ; 47(1): 127-135, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34480684

RESUMO

Tattoos of formerly gang-involved and incarcerated individuals can negatively impact their ability to reintegrate into society. Laser tattoo removal is essential to helping individuals obtain employment, re-cultivate positive relationships, and disengage from gangs. The objective of this study is to describe the demographics and motivations for laser tattoo removal at a large nonprofit clinic. This was a single center retrospective study conducted on patients presenting to Ya'stuvo Tattoo Removal between January 2016-December 2018 and had at least three laser tattoo removal sessions. Data was recorded on patient demographics, geographic location of residence (e.g. zipcode), comorbidities, probation/parole status, referral source, transportation mode, and motivations for receiving and removing tattoos. A representative sample of 862 patients was used to conduct our analysis. Average age at first visit was 30. 16% (n = 134) were on probation, 8% (n = 66) were on parole, and 63% (n = 544) did not report their probation/parole status. Reasons for receiving a tattoo included gangs (46%, n = 368), a current or ex-relationship (28%, n = 223), and decoration (20%, n = 159). The most common reasons for tattoo removal were employment (66%, n = 546), readiness to change life (47%, n = 392), maturity (47%, n = 392), family (43%, n = 356), and negative attention from tattoos (37%, n = 303). The current study highlights the importance of laser tattoo removal in reintegration and gang disengagement. Expanding cost efficient laser tattoo removal is paramount to meet the safety and socioeconomic needs of this population.


Assuntos
Tatuagem , Humanos , Lasers , Motivação , Estudos Retrospectivos , Populações Vulneráveis
5.
Neuroimage ; 208: 116436, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31809885

RESUMO

Auditory distance perception and its neuronal mechanisms are poorly understood, mainly because 1) it is difficult to separate distance processing from intensity processing, 2) multiple intensity-independent distance cues are often available, and 3) the cues are combined in a context-dependent way. A recent fMRI study identified human auditory cortical area representing intensity-independent distance for sources presented along the interaural axis (Kopco et al. PNAS, 109, 11019-11024). For these sources, two intensity-independent cues are available, interaural level difference (ILD) and direct-to-reverberant energy ratio (DRR). Thus, the observed activations may have been contributed by not only distance-related, but also direction-encoding neuron populations sensitive to ILD. Here, the paradigm from the previous study was used to examine DRR-based distance representation for sounds originating in front of the listener, where ILD is not available. In a virtual environment, we performed behavioral and fMRI experiments, combined with computational analyses to identify the neural representation of distance based on DRR. The stimuli varied in distance (15-100 â€‹cm) while their received intensity was varied randomly and independently of distance. Behavioral performance showed that intensity-independent distance discrimination is accurate for frontal stimuli, even though it is worse than for lateral stimuli. fMRI activations for sounds varying in frontal distance, as compared to varying only in intensity, increased bilaterally in the posterior banks of Heschl's gyri, the planum temporale, and posterior superior temporal gyrus regions. Taken together, these results suggest that posterior human auditory cortex areas contain neuron populations that are sensitive to distance independent of intensity and of binaural cues relevant for directional hearing.


Assuntos
Córtex Auditivo/fisiologia , Percepção Auditiva/fisiologia , Mapeamento Encefálico , Sinais (Psicologia) , Percepção de Distância/fisiologia , Adulto , Córtex Auditivo/diagnóstico por imagem , Discriminação Psicológica/fisiologia , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Modelos Teóricos , Vias Neurais/fisiologia , Psicofísica , Adulto Jovem
6.
Brain Topogr ; 33(4): 477-488, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32441009

RESUMO

Auditory attention allows us to focus on relevant target sounds in the acoustic environment while maintaining the capability to orient to unpredictable (novel) sound changes. An open question is whether orienting to expected vs. unexpected auditory events are governed by anatomically distinct attention pathways, respectively, or by differing communication patterns within a common system. To address this question, we applied a recently developed PeSCAR analysis method to evaluate spectrotemporal functional connectivity patterns across subregions of broader cortical regions of interest (ROIs) to analyze magnetoencephalography data obtained during a cued auditory attention task. Subjects were instructed to detect a predictable harmonic target sound embedded among standard tones in one ear and to ignore the standard tones and occasional unpredictable novel sounds presented in the opposite ear. Phase coherence of estimated source activity was calculated between subregions of superior temporal, frontal, inferior parietal, and superior parietal cortex ROIs. Functional connectivity was stronger in response to target than novel stimuli between left superior temporal and left parietal ROIs and between left frontal and right parietal ROIs, with the largest effects observed in the beta band (15-35 Hz). In contrast, functional connectivity was stronger in response to novel than target stimuli in inter-hemispheric connections between left and right frontal ROIs, observed in early time windows in the alpha band (8-12 Hz). Our findings suggest that auditory processing of expected target vs. unexpected novel sounds involves different spatially, temporally, and spectrally distributed oscillatory connectivity patterns across temporal, parietal, and frontal areas.


Assuntos
Atenção , Córtex Auditivo , Percepção Auditiva , Magnetoencefalografia , Estimulação Acústica , Mapeamento Encefálico , Feminino , Humanos , Lobo Parietal
7.
Neuroimage ; 161: 1-8, 2017 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-28818692

RESUMO

Auditory working memory (WM) processing in everyday acoustic environments depends on our ability to maintain relevant information online in our minds, and to suppress interference caused by competing incoming stimuli. A challenge in communication settings is that the relevant content and irrelevant inputs may emanate from a common source, such as a talkative conversationalist. An open question is how the WM system deals with such interference. Will the distracters become inadvertently filtered before processing for meaning because the primary WM operations deplete all available processing resources? Or are they suppressed post perceptually, through an active control process? We tested these alternative hypotheses by measuring magnetoencephalography (MEG), EEG, and functional MRI (fMRI) during a phonetic auditory continuous performance task. Contextual WM maintenance load was manipulated by adjusting the number of "filler" letter sounds in-between cue and target letter sounds. Trial-to-trial variability of pre- and post-stimulus activations in fMRI-informed cortical MEG/EEG estimates was analyzed within and across 14 subjects using generalized linear mixed effect (GLME) models. High contextual WM maintenance load suppressed left auditory cortex (AC) activations around 250-300 ms after the onset of irrelevant phonetic sounds. This effect coincided with increased 10-14 Hz alpha-range oscillatory functional connectivity between the left dorsolateral prefrontal cortex (DLPFC) and left AC. Suppression of AC responses to irrelevant sounds during active maintenance of the task context also correlated with increased pre-stimulus 7-15 Hz alpha power. Our results suggest that under high auditory WM load, irrelevant sounds are suppressed through a "late" active suppression mechanism, which prevents short-term consolidation of irrelevant information without affecting the initial screening of potentially meaningful stimuli. The results also suggest that AC alpha oscillations play an inhibitory role during auditory WM processing.


Assuntos
Ritmo alfa/fisiologia , Atenção/fisiologia , Córtex Auditivo/fisiologia , Percepção Auditiva/fisiologia , Conectoma/métodos , Magnetoencefalografia/métodos , Memória de Curto Prazo/fisiologia , Córtex Pré-Frontal/fisiologia , Adulto , Córtex Auditivo/diagnóstico por imagem , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Córtex Pré-Frontal/diagnóstico por imagem , Adulto Jovem
8.
Neuroimage ; 124(Pt A): 858-868, 2016 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-26419388

RESUMO

Spatial and non-spatial information of sound events is presumably processed in parallel auditory cortex (AC) "what" and "where" streams, which are modulated by inputs from the respective visual-cortex subsystems. How these parallel processes are integrated to perceptual objects that remain stable across time and the source agent's movements is unknown. We recorded magneto- and electroencephalography (MEG/EEG) data while subjects viewed animated video clips featuring two audiovisual objects, a black cat and a gray cat. Adaptor-probe events were either linked to the same object (the black cat meowed twice in a row in the same location) or included a visually conveyed identity change (the black and then the gray cat meowed with identical voices in the same location). In addition to effects in visual (including fusiform, middle temporal or MT areas) and frontoparietal association areas, the visually conveyed object-identity change was associated with a release from adaptation of early (50-150ms) activity in posterior ACs, spreading to left anterior ACs at 250-450ms in our combined MEG/EEG source estimates. Repetition of events belonging to the same object resulted in increased theta-band (4-8Hz) synchronization within the "what" and "where" pathways (e.g., between anterior AC and fusiform areas). In contrast, the visually conveyed identity changes resulted in distributed synchronization at higher frequencies (alpha and beta bands, 8-32Hz) across different auditory, visual, and association areas. The results suggest that sound events become initially linked to perceptual objects in posterior AC, followed by modulations of representations in anterior AC. Hierarchical what and where pathways seem to operate in parallel after repeating audiovisual associations, whereas the resetting of such associations engages a distributed network across auditory, visual, and multisensory areas.


Assuntos
Córtex Auditivo/fisiologia , Vias Auditivas/fisiologia , Percepção Auditiva/fisiologia , Percepção Visual/fisiologia , Estimulação Acústica , Adulto , Animais , Gatos , Sincronização Cortical , Eletroencefalografia , Potenciais Evocados Auditivos/fisiologia , Feminino , Humanos , Magnetoencefalografia , Masculino , Pessoa de Meia-Idade , Estimulação Luminosa , Córtex Visual/fisiologia , Vocalização Animal , Adulto Jovem
9.
Neuroimage ; 143: 116-127, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27608603

RESUMO

Despite recent advances in auditory neuroscience, the exact functional organization of human auditory cortex (AC) has been difficult to investigate. Here, using reversals of tonotopic gradients as the test case, we examined whether human ACs can be more precisely mapped by avoiding signals caused by large draining vessels near the pial surface, which bias blood-oxygen level dependent (BOLD) signals away from the actual sites of neuronal activity. Using ultra-high field (7T) fMRI and cortical depth analysis techniques previously applied in visual cortices, we sampled 1mm isotropic voxels from different depths of AC during narrow-band sound stimulation with biologically relevant temporal patterns. At the group level, analyses that considered voxels from all cortical depths, but excluded those intersecting the pial surface, showed (a) the greatest statistical sensitivity in contrasts between activations to high vs. low frequency sounds and (b) the highest inter-subject consistency of phase-encoded continuous tonotopy mapping. Analyses based solely on voxels intersecting the pial surface produced the least consistent group results, even when compared to analyses based solely on voxels intersecting the white-matter surface where both signal strength and within-subject statistical power are weakest. However, no evidence was found for reduced within-subject reliability in analyses considering the pial voxels only. Our group results could, thus, reflect improved inter-subject correspondence of high and low frequency gradients after the signals from voxels near the pial surface are excluded. Using tonotopy analyses as the test case, our results demonstrate that when the major physiological and anatomical biases imparted by the vasculature are controlled, functional mapping of human ACs becomes more consistent from subject to subject than previously thought.


Assuntos
Córtex Auditivo/fisiologia , Mapeamento Encefálico/métodos , Córtex Cerebral/diagnóstico por imagem , Veias Cerebrais/diagnóstico por imagem , Pia-Máter/diagnóstico por imagem , Percepção da Fala/fisiologia , Adulto , Córtex Auditivo/diagnóstico por imagem , Mapeamento Encefálico/normas , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Pia-Máter/irrigação sanguínea , Adulto Jovem
10.
Neuroimage ; 114: 49-56, 2015 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-25842290

RESUMO

Naturalistic stimuli such as movies are increasingly used to engage cognitive and emotional processes during fMRI of brain hemodynamic activity. However, movies have been little utilized during magnetoencephalography (MEG) and EEG that directly measure population-level neuronal activity at a millisecond resolution. Here, subjects watched a 17-min segment from the movie Crash (Lionsgate Films, 2004) twice during simultaneous MEG/EEG recordings. Physiological noise components, including ocular and cardiac artifacts, were removed using the DRIFTER algorithm. Dynamic estimates of cortical activity were calculated using MRI-informed minimum-norm estimation. To improve the signal-to-noise ratio (SNR), principal component analyses (PCA) were employed to extract the prevailing temporal characteristics within each anatomical parcel of the Freesurfer Desikan-Killiany cortical atlas. A variety of alternative inter-subject correlation (ISC) approaches were then utilized to investigate the reliability of inter-subject synchronization during natural viewing. In the first analysis, the ISCs of the time series of each anatomical region over the full time period across all subject pairs were calculated and averaged. In the second analysis, dynamic ISC (dISC) analysis, the correlation was calculated over a sliding window of 200 ms with 3.3 ms steps. Finally, in a between-run ISC analysis, the between-run correlation was calculated over the dynamic ISCs of the two different runs after the Fisher z-transformation. Overall, the most reliable activations occurred in occipital/inferior temporal visual and superior temporal auditory cortices as well as in the posterior cingulate, precuneus, pre- and post-central gyri, and right inferior and middle frontal gyri. Significant between-run ISCs were observed in superior temporal auditory cortices and inferior temporal visual cortices. Taken together, our results show that movies can be utilized as naturalistic stimuli in MEG/EEG similarly as in fMRI studies.


Assuntos
Córtex Cerebral/fisiologia , Eletroencefalografia/métodos , Magnetoencefalografia/métodos , Percepção Visual/fisiologia , Adolescente , Adulto , Artefatos , Feminino , Humanos , Masculino , Filmes Cinematográficos , Estimulação Luminosa , Processamento de Sinais Assistido por Computador , Adulto Jovem
11.
Proc Natl Acad Sci U S A ; 109(27): 11019-24, 2012 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-22699495

RESUMO

Neuronal mechanisms of auditory distance perception are poorly understood, largely because contributions of intensity and distance processing are difficult to differentiate. Typically, the received intensity increases when sound sources approach us. However, we can also distinguish between soft-but-nearby and loud-but-distant sounds, indicating that distance processing can also be based on intensity-independent cues. Here, we combined behavioral experiments, fMRI measurements, and computational analyses to identify the neural representation of distance independent of intensity. In a virtual reverberant environment, we simulated sound sources at varying distances (15-100 cm) along the right-side interaural axis. Our acoustic analysis suggested that, of the individual intensity-independent depth cues available for these stimuli, direct-to-reverberant ratio (D/R) is more reliable and robust than interaural level difference (ILD). However, on the basis of our behavioral results, subjects' discrimination performance was more consistent with complex intensity-independent distance representations, combining both available cues, than with representations on the basis of either D/R or ILD individually. fMRI activations to sounds varying in distance (containing all cues, including intensity), compared with activations to sounds varying in intensity only, were significantly increased in the planum temporale and posterior superior temporal gyrus contralateral to the direction of stimulation. This fMRI result suggests that neurons in posterior nonprimary auditory cortices, in or near the areas processing other auditory spatial features, are sensitive to intensity-independent sound properties relevant for auditory distance perception.


Assuntos
Córtex Auditivo/fisiologia , Vias Auditivas/fisiologia , Percepção Auditiva/fisiologia , Modelos Neurológicos , Localização de Som/fisiologia , Estimulação Acústica/métodos , Adaptação Fisiológica/fisiologia , Adulto , Córtex Auditivo/citologia , Vias Auditivas/citologia , Mapeamento Encefálico , Sinais (Psicologia) , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Neurônios/fisiologia , Psicoacústica , Percepção Espacial/fisiologia , Adulto Jovem
12.
Neuroimage ; 86: 461-9, 2014 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-24185023

RESUMO

Based on the infamous left-lateralized neglect syndrome, one might hypothesize that the dominating right parietal cortex has a bilateral representation of space, whereas the left parietal cortex represents only the contralateral right hemispace. Whether this principle applies to human auditory attention is not yet fully clear. Here, we explicitly tested the differences in cross-hemispheric functional coupling between the intraparietal sulcus (IPS) and auditory cortex (AC) using combined magnetoencephalography (MEG), EEG, and functional MRI (fMRI). Inter-regional pairwise phase consistency (PPC) was analyzed from data obtained during dichotic auditory selective attention task, where subjects were in 10-s trials cued to attend to sounds presented to one ear and to ignore sounds presented in the opposite ear. Using MEG/EEG/fMRI source modeling, parietotemporal PPC patterns were (a) mapped between all AC locations vs. IPS seeds and (b) analyzed between four anatomically defined AC regions-of-interest (ROI) vs. IPS seeds. Consistent with our hypothesis, stronger cross-hemispheric PPC was observed between the right IPS and left AC for attended right-ear sounds, as compared to PPC between the left IPS and right AC for attended left-ear sounds. In the mapping analyses, these differences emerged at 7-13Hz, i.e., at the theta to alpha frequency bands, and peaked in Heschl's gyrus and lateral posterior non-primary ACs. The ROI analysis revealed similarly lateralized differences also in the beta and lower theta bands. Taken together, our results support the view that the right parietal cortex dominates auditory spatial attention.


Assuntos
Atenção/fisiologia , Percepção Auditiva/fisiologia , Relógios Biológicos/fisiologia , Sincronização Cortical/fisiologia , Lateralidade Funcional/fisiologia , Lobo Parietal/fisiologia , Lobo Temporal/fisiologia , Estimulação Acústica/métodos , Mapeamento Encefálico , Sinais (Psicologia) , Humanos , Masculino , Adulto Jovem
13.
Proc Natl Acad Sci U S A ; 108(10): 4182-7, 2011 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-21368107

RESUMO

How can we concentrate on relevant sounds in noisy environments? A "gain model" suggests that auditory attention simply amplifies relevant and suppresses irrelevant afferent inputs. However, it is unclear whether this suffices when attended and ignored features overlap to stimulate the same neuronal receptive fields. A "tuning model" suggests that, in addition to gain, attention modulates feature selectivity of auditory neurons. We recorded magnetoencephalography, EEG, and functional MRI (fMRI) while subjects attended to tones delivered to one ear and ignored opposite-ear inputs. The attended ear was switched every 30 s to quantify how quickly the effects evolve. To produce overlapping inputs, the tones were presented alone vs. during white-noise masking notch-filtered ±1/6 octaves around the tone center frequencies. Amplitude modulation (39 vs. 41 Hz in opposite ears) was applied for "frequency tagging" of attention effects on maskers. Noise masking reduced early (50-150 ms; N1) auditory responses to unattended tones. In support of the tuning model, selective attention canceled out this attenuating effect but did not modulate the gain of 50-150 ms activity to nonmasked tones or steady-state responses to the maskers themselves. These tuning effects originated at nonprimary auditory cortices, purportedly occupied by neurons that, without attention, have wider frequency tuning than ±1/6 octaves. The attentional tuning evolved rapidly, during the first few seconds after attention switching, and correlated with behavioral discrimination performance. In conclusion, a simple gain model alone cannot explain auditory selective attention. In nonprimary auditory cortices, attention-driven short-term plasticity retunes neurons to segregate relevant sounds from noise.


Assuntos
Atenção , Córtex Auditivo/fisiologia , Plasticidade Neuronal , Ruído , Eletroencefalografia , Humanos , Imageamento por Ressonância Magnética
14.
J Cogn Neurosci ; 25(11): 1926-43, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23915050

RESUMO

In everyday listening situations, we need to constantly switch between alternative sound sources and engage attention according to cues that match our goals and expectations. The exact neuronal bases of these processes are poorly understood. We investigated oscillatory brain networks controlling auditory attention using cortically constrained fMRI-weighted magnetoencephalography/EEG source estimates. During consecutive trials, participants were instructed to shift attention based on a cue, presented in the ear where a target was likely to follow. To promote audiospatial attention effects, the targets were embedded in streams of dichotically presented standard tones. Occasionally, an unexpected novel sound occurred opposite to the cued ear to trigger involuntary orienting. According to our cortical power correlation analyses, increased frontoparietal/temporal 30-100 Hz gamma activity at 200-1400 msec after cued orienting predicted fast and accurate discrimination of subsequent targets. This sustained correlation effect, possibly reflecting voluntary engagement of attention after the initial cue-driven orienting, spread from the TPJ, anterior insula, and inferior frontal cortices to the right FEFs. Engagement of attention to one ear resulted in a significantly stronger increase of 7.5-15 Hz alpha in the ipsilateral than contralateral parieto-occipital cortices 200-600 msec after the cue onset, possibly reflecting cross-modal modulation of the dorsal visual pathway during audiospatial attention. Comparisons of cortical power patterns also revealed significant increases of sustained right medial frontal cortex theta power, right dorsolateral pFC and anterior insula/inferior frontal cortex beta power, and medial parietal cortex and posterior cingulate cortex gamma activity after cued versus novelty-triggered orienting (600-1400 msec). Our results reveal sustained oscillatory patterns associated with voluntary engagement of auditory spatial attention, with the frontoparietal and temporal gamma increases being best predictors of subsequent behavioral performance.


Assuntos
Atenção/fisiologia , Percepção Auditiva/fisiologia , Sinais (Psicologia) , Orientação/fisiologia , Adulto , Córtex Cerebral/fisiologia , Interpretação Estatística de Dados , Eletroencefalografia , Feminino , Lobo Frontal/fisiologia , Lateralidade Funcional/fisiologia , Humanos , Magnetoencefalografia , Masculino , Lobo Parietal/fisiologia , Adulto Jovem
15.
Neuroimage ; 83: 1098-108, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23921102

RESUMO

Auditory attention and working memory (WM) allow for selection and maintenance of relevant sound information in our minds, respectively, thus underlying goal-directed functioning in everyday acoustic environments. It is still unclear whether these two closely coupled functions are based on a common neural circuit, or whether they involve genuinely distinct subfunctions with separate neuronal substrates. In a full factorial functional MRI (fMRI) design, we independently manipulated the levels of auditory-verbal WM load and attentional interference using modified Auditory Continuous Performance Tests. Although many frontoparietal regions were jointly activated by increases of WM load and interference, there was a double dissociation between prefrontal cortex (PFC) subareas associated selectively with either auditory attention or WM. Specifically, anterior dorsolateral PFC (DLPFC) and the right anterior insula were selectively activated by increasing WM load, whereas subregions of middle lateral PFC and inferior frontal cortex (IFC) were associated with interference only. Meanwhile, a superadditive interaction between interference and load was detected in left medial superior frontal cortex, suggesting that in this area, activations are not only overlapping, but reflect a common resource pool recruited by increased attentional and WM demands. Indices of WM-specific suppression of anterolateral non-primary auditory cortices (AC) and attention-specific suppression of primary AC were also found, possibly reflecting suppression/interruption of sound-object processing of irrelevant stimuli during continuous task performance. Our results suggest a double dissociation between auditory attention and working memory in subregions of anterior DLPFC vs. middle lateral PFC/IFC in humans, respectively, in the context of substantially overlapping circuits.


Assuntos
Atenção/fisiologia , Percepção Auditiva/fisiologia , Memória de Curto Prazo/fisiologia , Vias Neurais/fisiologia , Córtex Pré-Frontal/fisiologia , Adulto , Mapeamento Encefálico , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Masculino , Adulto Jovem
16.
Neuroimage ; 78: 325-38, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23563228

RESUMO

The acquisition time of BOLD contrast functional MRI (fMRI) data with whole-brain coverage typically requires a sampling rate of one volume in 1-3s. Although the volumetric sampling time of a few seconds is adequate for measuring the sluggish hemodynamic response (HDR) to neuronal activation, faster sampling of fMRI might allow for monitoring of rapid physiological fluctuations and detection of subtle neuronal activation timing information embedded in BOLD signals. Previous studies utilizing a highly accelerated volumetric MR inverse imaging (InI) technique have provided a sampling rate of one volume per 100 ms with 5mm spatial resolution. Here, we propose a novel modification of this technique, the echo-shifted InI, which allows TE to be longer than TR, to measure BOLD fMRI at an even faster sampling rate of one volume per 25 ms with whole-brain coverage. Compared with conventional EPI, echo-shifted InI provided an 80-fold speedup with similar spatial resolution and less than 2-fold temporal SNR loss. The capability of echo-shifted InI to detect HDR timing differences was tested empirically. At the group level (n=6), echo-spaced InI was able to detect statistically significant HDR timing differences of as low as 50 ms in visual stimulus presentation. At the level of individual subjects, significant differences in HDR timing were detected for 400 ms stimulus-onset differences. Our results also show that the temporal resolution of 25 ms is necessary for maintaining the temporal detecting capability at this level. With the capabilities of being able to distinguish the timing differences in the millisecond scale, echo-shifted InI could be a useful fMRI tool for obtaining temporal information at a time scale closer to that of neuronal dynamics.


Assuntos
Mapeamento Encefálico/métodos , Imageamento por Ressonância Magnética/métodos , Córtex Visual/fisiologia , Humanos , Processamento de Imagem Assistida por Computador/métodos , Estimulação Luminosa
17.
Plast Reconstr Surg Glob Open ; 11(7): e5120, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37448761

RESUMO

In this report, we present a 57-year-old man with chronic bilateral lower extremity wounds from nonuremic calciphylaxis, which were successfully reconstructed using a piscine-derived acellular dermal matrix. The acellular dermal matrix incorporated quickly, providing a wound bed that was amenable to skin grafting. We demonstrate that this is an effective off-the-shelf solution for these chronic wounds, resulting in pain reduction and complete closure of the wounds, allowing the patient to return to his previous baseline activities, and improving his quality of life.

18.
Burns ; 49(1): 15-25, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-35842270

RESUMO

INTRODUCTION: Mucormycosis is an opportunistic fungal infection with a high mortality rate. Though typically associated with diabetes and other conditions that affect innate immune function, infections can also be precipitated by conditions such as trauma and burns. Burn patients are particularly susceptible to fungal infections due to the immune dysfunction that often accompany their wounds. Indeed case series have described mucormycosis to occur in patients with burn injuries, however the factors contributing to mortality have not been well described. Thus, the purpose of our review was to identify factors contributing to morbidity and mortality in burn patients with Mucormycosis. METHODS: A systematic review of the literature of mucormycosis infection in burn injury patients was performed on Pubmed and Google Scholar using the keywords: Mucor, Mucorales, Mucormycosis, Mucormycotina, Zygomycosis and burn or thermal injury. Clinical trials, observational studies, case reports, and case reviews were included if they provided information regarding mortality in adult and pediatric burn patients diagnosed with mucormycosis, review articles, non-English articles, and articles without patient information were excluded. No time limit was placed on our review. Individual patient data was stratified based on mortality. Statistical analysis was performed to investigate the relationship between patient risk factors and mortality, and the Oxford Level of Evidence was used to evaluate study quality. RESULTS: 46 articles were included in our final review, encompassing 114 patients. On average, survivors had a total body surface area (TBSA)% of 46 (SD 19.8) while non-survivors had a TBSA of 65% (SD 16.4), and this difference was significant (p < .001). Patients with disseminated mucormycosis experienced an 80% mortality rate compared to 36% mortality rate in patients with localized disease (p < .001). We found no statistically significant difference in mean age (p > .05), diabetes (p > .05), mean delay in diagnosis (p > .05), time to antifungal therapy (p > .05), or type of therapy used (p > .05) between survivors and non-survivors. Our review was limited by the lack of prospective, controlled trials; thus, our review primarily consists of case reports. CONCLUSION: Disseminated infections and higher TBSA both increased the risk of mortality in burn patients with mucormycosis, while diabetes did not increase mortality risk. The severity of the initial injury and infection locations must be taken into consideration to inform patient prognosis.


Assuntos
Queimaduras , Mucormicose , Adulto , Humanos , Criança , Queimaduras/terapia , Mucormicose/epidemiologia , Mucormicose/diagnóstico , Mucormicose/microbiologia , Fatores de Risco , Prognóstico , Estudos Retrospectivos
19.
Case Rep Infect Dis ; 2022: 7250294, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35480341

RESUMO

A 67-year-old male presented with complaints of weakness, fatigue, and shortness of breath in the context of a recent hospitalization for the same unresolved symptoms. After a largely nonspecific clinical presentation, a chest X-ray revealed a loculated pleural effusion. Culture of the postthoracentesis exudate revealed the culprit to be the aerobic Gram-negative bacterium Francisella tularensis. Amidst reports of potential resurgence, clinicians should be aware of the possible presentations of tularemia and consider it in the case of an ostensibly contributory patient history.

20.
J Burn Care Res ; 43(2): 368-373, 2022 03 23.
Artigo em Inglês | MEDLINE | ID: mdl-34534314

RESUMO

Pain following burn injury is associated with long-term health consequences in the pediatric population. Literature suggests nonpharmacologic treatment may provide improved pain control as an effective adjunct for these patients. This study aims to summarize randomized controlled trials on nonpharmacologic procedural pain management in pediatric burn patients. A systematic review was conducted on nonpharmacologic procedural pain management techniques used in the pediatric burn population. Fifteen studies were included and involved virtual reality, distraction devices, child life therapy, directed play, digital tablet games, cartoons, hypnosis, and music therapy. Treatment was effective in 8 out of 15 studies. Compared to controls, nonpharmacologic treatments reduced mid procedure pain by 19.7% and post-procedure pain by 20.1%. This study demonstrates that nonpharmacologic therapy can be an effective adjunct in pediatric procedural burn pain management, however further studies are needed to develop standardized algorithms to integrate nonpharmacologic treatments with pharmacologic therapies.


Assuntos
Queimaduras , Dor Processual , Queimaduras/complicações , Queimaduras/terapia , Criança , Humanos , Dor/etiologia , Manejo da Dor/métodos , Dor Processual/etiologia , Dor Processual/prevenção & controle , Ensaios Clínicos Controlados Aleatórios como Assunto
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