Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 20
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
Cereb Cortex ; 33(11): 7044-7060, 2023 05 24.
Artigo em Inglês | MEDLINE | ID: mdl-36786655

RESUMO

Human auditory cortex (AC) organization resembles the core-belt-parabelt organization in nonhuman primates. Previous studies assessed mostly spatial characteristics; however, temporal aspects were little considered so far. We employed co-registration of functional magnetic resonance imaging (fMRI) and magnetoencephalography (MEG) in musicians with and without absolute pitch (AP) to achieve spatial and temporal segregation of human auditory responses. First, individual fMRI activations induced by complex harmonic tones were consistently identified in four distinct regions-of-interest within AC, namely in medial Heschl's gyrus (HG), lateral HG, anterior superior temporal gyrus (STG), and planum temporale (PT). Second, we analyzed the temporal dynamics of individual MEG responses at the location of corresponding fMRI activations. In the AP group, the auditory evoked P2 onset occurred ~25 ms earlier in the right as compared with the left PT and ~15 ms earlier in the right as compared with the left anterior STG. This effect was consistent at the individual level and correlated with AP proficiency. Based on the combined application of MEG and fMRI measurements, we were able for the first time to demonstrate a characteristic temporal hierarchy ("chronotopy") of human auditory regions in relation to specific auditory abilities, reflecting the prediction for serial processing from nonhuman studies.


Assuntos
Córtex Auditivo , Animais , Humanos , Córtex Auditivo/diagnóstico por imagem , Córtex Auditivo/fisiologia , Potenciais Evocados Auditivos/fisiologia , Estimulação Acústica , Mapeamento Encefálico/métodos , Magnetoencefalografia/métodos , Imageamento por Ressonância Magnética/métodos
2.
Ann N Y Acad Sci ; 1517(1): 176-190, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36114664

RESUMO

Although there is strong evidence for the positive effects of musical training on auditory perception, processing, and training-induced neuroplasticity, there is still little knowledge on the auditory and neurophysiological short-term plasticity through listening training. In a sample of 37 adolescents (20 musicians and 17 nonmusicians) that was compared to a control group matched for age, gender, and musical experience, we conducted a 2-week active listening training (AULOS: Active IndividUalized Listening OptimizationS). Using magnetoencephalography and psychoacoustic tests, the short-term plasticity of auditory evoked fields and auditory skills were examined in a pre-post design, adapted to the individual neuro-auditory profiles. We found bilateral, but more pronounced plastic changes in the right auditory cortex. Moreover, we observed synchronization of the auditory evoked P1, N1, and P2 responses and threefold larger amplitudes of the late P2 response, similar to the reported effects of musical long-term training. Auditory skills and thresholds benefited largely from the AULOS training. Remarkably, after training, the mean thresholds improved by 12 dB for bone conduction and by 3-4 dB for air conduction. Thus, our findings indicate a strong positive influence of active listening training on neural auditory processing and perception in adolescence, when the auditory system is still developing.


Assuntos
Córtex Auditivo , Música , Adolescente , Humanos , Recém-Nascido , Percepção Auditiva/fisiologia , Córtex Auditivo/fisiologia , Magnetoencefalografia , Plasticidade Neuronal/fisiologia , Potenciais Evocados Auditivos/fisiologia , Estimulação Acústica
3.
Multisens Res ; 34(2): 113-127, 2020 08 03.
Artigo em Inglês | MEDLINE | ID: mdl-33706275

RESUMO

The crossmodal correspondence between auditory pitch and visuospatial elevation (in which high- and low-pitched tones are associated with high and low spatial elevation respectively) has been proposed as the basis for Western musical notation. One implication of this is that music perception engages visuospatial processes and may not be exclusively auditory. Here, we investigated how music perception is influenced by concurrent visual stimuli. Participants listened to unfamiliar five-note musical phrases with four kinds of pitch contour (rising, falling, rising-falling, or falling-rising), accompanied by incidental visual contours that were either congruent (e.g., auditory rising/visual rising) or incongruent (e.g., auditory rising/visual falling) and judged whether the final note of the musical phrase was higher or lower in pitch than the first. Response times for the auditory judgment were significantly slower for incongruent compared to congruent trials, i.e., there was a congruency effect, even though the visual contours were incidental to the auditory task. These results suggest that music perception, although generally regarded as an auditory experience, may actually be multisensory in nature.


Assuntos
Música , Estimulação Acústica , Percepção Auditiva , Humanos , Percepção da Altura Sonora , Tempo de Reação , Percepção Visual
4.
Int J Legal Med ; 131(6): 1597-1613, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28717962

RESUMO

Sudden infant death syndrome (SIDS) remains one of the most common causes of post-neonatal infant mortality in developed countries. Its pathogenesis is still poorly understood. The goal of the present study was to characterize changes in the proteome of SIDS compared to age-matched controls in heart and medulla tissues as well as in blood samples using two complementary quantitative proteomic techniques: 2D-DIGE and iTRAQ aiming to provide new insights into the mechanism of SIDS and to find diagnostic protein patterns. Our results revealed collectively 122 modulated proteins in SIDS of which 83 proteins were up-regulated. They are involved in metabolic processes, cellular processes, and localization. Gene expression patterns of selected proteins were further validated by reverse transcription quantitative real-time PCR (RT-qPCR). The role of hypoxia, inflammation, and apoptosis in SIDS was demonstrated by exploring some candidate proteins especially APOA1, GAPDH, S100B, zyxin, and complement component C4A. According to the results of this study, these proteins might be used as diagnostic biomarkers for SIDS. All of them were up-regulated in SIDS except for C4A that was down-regulated.


Assuntos
Proteoma/genética , Proteoma/metabolismo , Proteômica , Morte Súbita do Lactente , Apolipoproteína A-I/genética , Apolipoproteína A-I/metabolismo , Biomarcadores/metabolismo , Estudos de Casos e Controles , Complemento C4a/genética , Complemento C4a/metabolismo , Regulação para Baixo , Patologia Legal , Expressão Gênica , Gliceraldeído-3-Fosfato Desidrogenase (Fosforiladora)/genética , Gliceraldeído-3-Fosfato Desidrogenase (Fosforiladora)/metabolismo , Humanos , Lactente , Recém-Nascido , Bulbo/patologia , Miocárdio/patologia , Reação em Cadeia da Polimerase em Tempo Real , Subunidade beta da Proteína Ligante de Cálcio S100/genética , Subunidade beta da Proteína Ligante de Cálcio S100/metabolismo , Regulação para Cima , Zixina/genética , Zixina/metabolismo
5.
Brain Struct Funct ; 222(8): 3587-3603, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28397108

RESUMO

Morphological variations of the first transverse Heschl's gyrus (HG) in the human auditory cortex (AC) are common, yet little is known about their functional implication. We investigated individual morphology and function of HG variations in the AC of 41 musicians, using structural and functional magnetic resonance imaging (fMRI) as well as magnetoencephalography (MEG). Four main morphotypes of HG were (i) single HG, (ii) common stem duplication (CSD), (iii) complete posterior duplication (CPD), and (iv) multiple duplications (MD). The vast majority of musicians (90%) exhibited HG multiplications (type ii-iv) in either one (39%) or both (51%) hemispheres. In 27% of musicians, MD with up to four gyri were found. To probe the functional contribution of HG multiplications to auditory processing we performed fMRI and MEG with auditory stimulation using analogous instrumental tone paradigms. Both methods pointed to the recruitment of all parts of HG during auditory stimulation, including multiplications if present. FMRI activations extended with the degree of HG gyrification. MEG source waveform patterns were distinct for the different types of HG: (i) hemispheres with single HG and (ii) CSD exhibited dominant N1 responses, whereas hemispheres with (iii) CPD and (iv) MD exhibited dominant P1 responses. N1 dipole amplitudes correlated with the localization of the first complete Heschl's sulcus (cHS), designating the most posterior anatomical border of HG. P2 amplitudes were significantly higher in professional as compared to amateur musicians. The results suggest that HG multiplications occur much more frequently in musicians than in the general population and constitute a functional unit with HG.


Assuntos
Córtex Auditivo/anatomia & histologia , Córtex Auditivo/fisiologia , Potenciais Evocados Auditivos , Música , Estimulação Acústica , Adulto , Mapeamento Encefálico , Feminino , Humanos , Imageamento por Ressonância Magnética , Magnetoencefalografia , Masculino , Competência Profissional
6.
J Vasc Surg ; 65(3): 603-608, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28236914

RESUMO

INTRODUCTION: When a patient with ruptured abdominal aortic aneurysm (rAAA) presents at a facility ill-equipped to provide care, transfer may provide the best chance for survival. Large distances and long travel times provide challenging barriers to prompt and appropriate care in the western United States. METHODS: The Western Vascular Society (WVS) adopted a set of guidelines in considering transfer of a patient with an rAAA using published literature, membership survey and input, and existing recommendations. This article reports the guidelines and describes the process and rationale behind their development. RESULTS: Fifteen guidelines for transfer and care of rAAAs were endorsed by the WVS. CONCLUSIONS: When local care cannot be provided, transfer guidelines may standardize care for rAAAs and may be applicable across may practice settings.


Assuntos
Aneurisma da Aorta Abdominal/cirurgia , Ruptura Aórtica/cirurgia , Prestação Integrada de Cuidados de Saúde/normas , Transferência de Pacientes/normas , Aneurisma da Aorta Abdominal/diagnóstico por imagem , Aneurisma da Aorta Abdominal/mortalidade , Ruptura Aórtica/diagnóstico por imagem , Ruptura Aórtica/mortalidade , Consenso , Emergências , Medicina Baseada em Evidências/normas , Humanos , Tempo para o Tratamento/normas , Resultado do Tratamento
7.
Phytochemistry ; 117: 254-266, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26101147

RESUMO

A phytochemical investigation of Tragopogon tommasinii Sch.Bip. (Asteraceae, Cichorieae) yielded a total of 21 natural products, two simple phenolic acids (4-hydroxybenzoic acid and p-coumaric acid), four caffeic acid derivatives (chlorogenic acid, 3-O-caffeoylquinic acid, 3,5-O-dicaffeoylquinic acid, and 4,5-O-dicaffeoylquinic acid), six flavonoids (luteolin, luteolin 7-O-glucoside, vitexin, orientin, quercetin 3-O-glucoside, and isorhamnetin 3-O-glucoside), three simple bibenzyls [2-carboxyl-5-hydroxy-3-methoxy-4'-ß-glucopyranosyl-oxybibenzyl, 3-caffeoyl-(9→5)-ß-apiosyl-(1→6)-ß-glucopyranosyloxy-5,4'-dihydroxy-3'-methoxybibenzyl, 3-caffeoyl-(9→5)-ß-apiosyl-(1→6)-ß-glucopyranosyloxy-4'-dihydroxy-5,3'-dimethoxybibenzyl], three phtalides [3-(4-ß-glucopyranosyloxybenzyl)-7-hydroxy-5-methoxyphtalide, 7-ß-glucopyranosyloxy-(S)-3-(4-hydroxybenzyl)-5-methoxyphtalide, and 7-(1→6)-α-rhamnosyl-ß-glucopyranosyloxy-(S)-3-(4-hydroxybenzyl)-5-methoxyphtalide], two cannabispiradienone derivatives [3-O-ß-glucopyranosyldemethoxycannabispiradienone and 3-caffeoyl-(9→5)-ß-apiosyl-(1→6)-ß-glucopyranosyloxydemethoxycannabispiradienone], and tetra-N-coumaroyl spermine. The three bibenzyls, the latter two benzylphthalides, and both cannabispiradienone derivatives represent new natural compounds and all compounds, except the caffeic acid derivatives and the flavonoids were new for T. tommasinii. The structures were established by HR mass spectrometry, extensive 1D and 2D NMR spectroscopy, and CD spectroscopy. Moreover, the potential anti-inflammatory activities of the new compounds were assayed using human neutrophils and their production of IL-1b, IL-8, TNF-α and MMP-9 as well as the expression of TLR-4, respectively.


Assuntos
Anti-Inflamatórios/química , Anti-Inflamatórios/farmacologia , Tragopogon/química , Adulto , Células Cultivadas , Dicroísmo Circular , Avaliação Pré-Clínica de Medicamentos/métodos , Flavonoides/química , Flavonoides/farmacologia , Glucosídeos/química , Glucosídeos/farmacologia , Glicosídeos/química , Humanos , Interleucina-8/metabolismo , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Neutrófilos/efeitos dos fármacos , Neutrófilos/metabolismo , Compostos de Espiro/química , Compostos de Espiro/farmacologia , Receptor 4 Toll-Like/metabolismo , Fator de Necrose Tumoral alfa/metabolismo
8.
Cereb Cortex ; 24(5): 1127-37, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-23302811

RESUMO

Absolute pitch (AP) perception is the auditory ability to effortlessly recognize the pitch of any given tone without external reference. To study the neural substrates of this rare phenomenon, we developed a novel behavioral test, which excludes memory-based interval recognition and permits quantification of AP proficiency independently of relative pitch cues. AP- and non-AP-possessing musicians were studied with morphological and functional magnetic resonance imaging (fMRI) and magnetoencephalography. Gray matter volume of the right Heschl's gyrus (HG) was highly correlated with AP proficiency. Right-hemispheric auditory evoked fields were increased in the AP group. fMRI revealed an AP-dependent network of right planum temporale, secondary somatosensory, and premotor cortices, as well as left-hemispheric "Broca's" area. We propose the right HG as an anatomical marker of AP and suggest that a right-hemispheric network mediates AP "perception," whereas pitch "labeling" takes place in the left hemisphere.


Assuntos
Córtex Auditivo/anatomia & histologia , Córtex Auditivo/fisiologia , Potenciais Evocados Auditivos/fisiologia , Lateralidade Funcional/fisiologia , Percepção da Altura Sonora/fisiologia , Estimulação Acústica , Adulto , Mapeamento Encefálico , Eletroencefalografia , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Magnetoencefalografia , Masculino , Pessoa de Meia-Idade , Oxigênio/sangue , Psicoacústica , Tempo de Reação/fisiologia , Análise de Regressão , Adulto Jovem
9.
Cortex ; 49(10): 2822-33, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23706955

RESUMO

Natural and behaviorally relevant sounds are characterized by temporal modulations of their waveforms, which carry important cues for sound segmentation and communication. Still, there is little consensus as to how this temporal information is represented in auditory cortex. Here, by using functional magnetic resonance imaging (fMRI) optimized for studying the auditory system, we report the existence of a topographically ordered spatial representation of temporal sound modulation rates in human auditory cortex. We found a topographically organized sensitivity within auditory cortex to sounds with varying modulation rates, with enhanced responses to lower modulation rates (2 and 4 Hz) on lateral parts of Heschl's gyrus (HG) and faster modulation rates (16 and 32 Hz) on medial HG. The representation of temporal modulation rates was distinct from the representation of sound frequencies (tonotopy) that was orientated roughly orthogonal. Moreover, the combination of probabilistic anatomical maps with a previously proposed functional delineation of auditory fields revealed that the distinct maps of temporal and spectral sound features both prevail within two presumed primary auditory fields hA1 and hR. Our results reveal a topographically ordered representation of temporal sound cues in human primary auditory cortex that is complementary to maps of spectral cues. They thereby enhance our understanding of the functional parcellation and organization of auditory cortical processing.


Assuntos
Córtex Auditivo/fisiologia , Sinais (Psicologia) , Localização de Som/fisiologia , Percepção Espacial/fisiologia , Estimulação Acústica , Adulto , Mapeamento Encefálico , Interpretação Estatística de Dados , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Masculino , Oxigênio/sangue , Percepção da Altura Sonora/fisiologia , Adulto Jovem
10.
Phytochemistry ; 72(11-12): 1379-89, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21550615

RESUMO

The genus Leontopodium, mainly distributed in Central and Eastern Asia, consists of ca. 34-58 different species. The European Leontopodium alpinum, commonly known as Edelweiss, has a long tradition in folk medicine. Recent research has resulted in the identification of prior unknown secondary metabolites, some of them with interesting biological activities. Despite this, nearly nothing is known about the Asian species of the genus. In this study, we applied proton nuclear magnetic resonance (¹H NMR) spectroscopy and liquid chromatography-mass spectrometry (LC-MS) metabolic fingerprinting to reveal insights into the metabolic patterns of 11 different Leontopodium species, and to conclude on their taxonomic relationship. Principal component analysis (PCA) of ¹H NMR fingerprints revealed two species groups. Discriminators for these groups were identified as fatty acids and sucrose for group A, and ent-kaurenoic acid and derivatives thereof for group B. Five diterpenes together with one sesquiterpene were isolated from Leontopodium franchetii roots; the compounds were described for the first time for L. franchetii: ent-kaur-16-en-19-oic acid, methyl-15α-angeloyloxy-ent-kaur-16-en-19-oate, methyl-ent-kaur-16-en-19-oate, 8-acetoxymodhephene, 19-acetoxy-ent-kaur-16-ene, methyl-15ß-angeloyloxy-16,17-epoxy-ent-kauran-19-oate. In addition, differences in the metabolic profile between collected and cultivated species could be observed using a partial least squares-discriminant analysis (PLS-DA). PCA of the LC-MS fingerprints revealed three groups. Discriminating signals were compared to literature data and identified as two bisabolane derivatives responsible for discrimination of group A and C, and one ent-kaurenoic acid derivative, discriminating group B. A taxonomic relationship between a previously unidentified species and L. franchetii and Leontopodium sinense could be determined by comparing NMR fingerprints. This finding supports recent molecular data. Furthermore, Leontopodium dedekensii and L. sinense, two closely related species in terms of morphology and DNA-fingerprints, could be distinguished clearly using ¹H NMR and LC-MS metabolic fingerprinting.


Assuntos
Asteraceae/química , Cromatografia Líquida de Alta Pressão/métodos , Diterpenos/análise , Espectroscopia de Ressonância Magnética/métodos , Metaboloma , Diterpenos/química , Meio Ambiente , Espectrometria de Massas/métodos , Análise Multivariada , Raízes de Plantas/química , Análise de Componente Principal , Sesquiterpenos/análise , Sesquiterpenos/química , Especificidade da Espécie
11.
Cytometry B Clin Cytom ; 80(4): 212-20, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21374796

RESUMO

BACKGROUND: With the intention to reduce overshooting immune response, glucocorticoids are frequently administered perioperatively in children undergoing open heart surgery. In a retrospective study we investigated extensively the modulation of the humoral and cellular immune response by methylprednisolone (MP). METHODS: This study was carried out on blood samples from two groups of children who had undergone surgical correction of atrial or ventricular septal defects, either without (MP⁻, n = 10), or with MP administration (MP+, n = 23, dose median 11 (IQR 10-16) mg kg⁻¹ body weight) before cardiopulmonary bypass (CPB, duration median 42 (IQR 36-65) min). EDTA blood was obtained 24 h preoperatively, after anesthesia, at CPB begin and end, 4, 24, and 48 h after surgery, at discharge and at out-patient follow-up (median 8.2 (IQR 3.3-12.2) months after surgery). Complex blood analysis including clinical chemistry and flow cytometry were performed to monitor humoral immune response, differential blood count, lymphocyte subsets, and the degree of activation of various leukocyte subpopulations. RESULTS: The patients' postoperative courses and follow-up were uneventful. Release of IL-6 and IL8 was reduced and that of the anti-inflammatory cytokine IL-10 upregulated by MP. Significant increase of circulating neutrophils and monocytes as inflammatory reaction to surgery and CPB contact was detected in both groups. However, invasion of monocytes to the periphery was delayed with MP. CD4+ and CD8+ T-lymphocyte counts were lower with MP treatment. B-lymphocyte count increased significantly after surgery in MP+ but remained constant in MP⁻ group. CONCLUSIONS: MP treatment partially decreased the pro-inflammatory effect of CPB surgery and induced anti-inflammatory effect on the cellular and humoral level.


Assuntos
Anti-Inflamatórios/uso terapêutico , Comunicação Interatrial/cirurgia , Comunicação Interventricular/cirurgia , Imunidade Celular/efeitos dos fármacos , Imunidade Humoral/efeitos dos fármacos , Metilprednisolona/uso terapêutico , Linfócitos T CD4-Positivos/patologia , Linfócitos T CD8-Positivos/patologia , Criança , Pré-Escolar , Feminino , Comunicação Interatrial/imunologia , Comunicação Interventricular/imunologia , Humanos , Hidrocortisona/sangue , Mediadores da Inflamação/sangue , Contagem de Leucócitos , Masculino , Metilprednisolona/farmacocinética , Período Pós-Operatório
12.
J Agric Food Chem ; 58(20): 10817-23, 2010 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-20886883

RESUMO

Today, the medicinal use of wormwood (Artemisia absinthium) is enjoying a resurgence of popularity. This study presents a specific and validated high-performance liquid chromatography (HPLC)-diode array detection method for the simultaneous determination and quantification of bioactive compounds in wormwood and commercial preparations thereof. Five sesquiterpene lactones, two lignans, and a polymethoxylated flavonoid were baseline separated on RP-18 material, using a solvent gradient consisting of 0.085% (v/v) o-phosphoric acid and acetonitrile. The flow rate was 1.0 mL/min, and chromatograms were recorded at 205 nm. The stability of absinthin was tested exposing samples to light, moisture, and different temperatures. Methanolic and aqueous solutions of absinthin were found to be stable for up to 6 months. This was also the case when the solid compound was kept in the refrigerator at -35 °C. In contrast, the colorless needles, when stored at room temperature, turned yellow. Three degradation compounds (anabsin, anabsinthin, and the new dimer 3'-hydroxyanabsinthin) were identified by HPLC-mass spectrometry and HPLC-solid-phase extraction-nuclear magnetic resonance and quantified by the established HPLC method.


Assuntos
Artemisia absinthium/química , Cromatografia Líquida de Alta Pressão/métodos , Espectroscopia de Ressonância Magnética/métodos , Espectrometria de Massas/métodos , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Extração em Fase Sólida/métodos , Cromatografia de Fase Reversa/métodos , Flavonoides/química , Flavonoides/isolamento & purificação , Lactonas/química , Lactonas/isolamento & purificação , Lignanas/química , Lignanas/isolamento & purificação , Estrutura Molecular , Sesquiterpenos/química , Sesquiterpenos/isolamento & purificação
13.
Clin Neurophysiol ; 118(10): 2276-81, 2007 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17709289

RESUMO

OBJECTIVE: A clear definition of pitch and timbre is still an open debate and often both terms are mixed up in investigations of tone height. However, fundamental frequency (f(0)) and spectral envelope of a sound play a major role in the perception of tone height. Recent electrophysiological experiments showed that one sub-component of the complex N 100-signal was found to be highly correlated to the perceived tone height. METHODS: Tone height was independently varied by both, a change of f(0) and spectral envelope in order to disentangle the influence of both parameters. Relative tone height was determined psychoacoustically. Neuromagnetic responses were evaluated using source-analysis. RESULTS: Perceived tone height increases with increasing f(0) or spectral envelope. Latency of the pitch change response (PCR) reacts oppositely for the two modi of tone height change. For increasing f(0) and fixed bandpass condition, tone height increases and the latency of the PCR decreases. In contrast, for increasing the center frequency of the bandpass with fixed f(0), tone height increases, but the latency of the PCR increases. CONCLUSIONS: The neuromagnetic pitch response is influenced by both, f(0) and spectral envelope. SIGNIFICANCE: Further investigations of the influence of pitch and timbre on neurophysiological pitch responses have to take into account that both, f(0) and spectral envelope, affect tone height and latency of the PCR.


Assuntos
Percepção da Altura Sonora/fisiologia , Estimulação Acústica , Adulto , Eletrofisiologia , Potenciais Evocados Auditivos/fisiologia , Feminino , Lateralidade Funcional/fisiologia , Humanos , Imageamento por Ressonância Magnética , Magnetoencefalografia , Masculino
14.
Neuroimage ; 34(4): 1637-42, 2007 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-17175176

RESUMO

Among other auditory operations, the analysis of different sound levels received at both ears is fundamental for the localization of a sound source. These so-called interaural level differences, in animals, are coded by excitatory-inhibitory neurons yielding asymmetric hemispheric activity patterns with acoustic stimuli having maximal interaural level differences. In human auditory cortex, the temporal blood oxygen level-dependent (BOLD) response to auditory inputs, as measured by functional magnetic resonance imaging (fMRI), consists of at least two independent components: an initial transient and a subsequent sustained signal, which, on a different time scale, are consistent with electrophysiological human and animal response patterns. However, their specific functional role remains unclear. Animal studies suggest these temporal components being based on different neural networks and having specific roles in representing the external acoustic environment. Here we hypothesized that the transient and sustained response constituents are differentially involved in coding interaural level differences and therefore play different roles in spatial information processing. Healthy subjects underwent monaural and binaural acoustic stimulation and BOLD responses were measured using high signal-to-noise-ratio fMRI. In the anatomically segmented Heschl's gyrus the transient response was bilaterally balanced, independent of the side of stimulation, while in opposite the sustained response was contralateralized. This dissociation suggests a differential role at these two independent temporal response components, with an initial bilateral transient signal subserving rapid sound detection and a subsequent lateralized sustained signal subserving detailed sound characterization.


Assuntos
Estimulação Acústica , Córtex Auditivo/fisiologia , Oxigênio/sangue , Adulto , Córtex Auditivo/irrigação sanguínea , Circulação Cerebrovascular , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética/métodos , Masculino , Valores de Referência
15.
J Agric Food Chem ; 54(22): 8432-6, 2006 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-17061817

RESUMO

In organic apple orcharding there is a continuous need for natural fungicides effective against Venturia inaequalis (Cooke) Winter, the causal agent of apple scab. In this study an in vitro assay is presented for determining the germination inhibitory potential of extracts and pure compounds. From a screening of plant extracts, the methanol extract of Morus root bark revealed distinct V. inaequalis inhibiting qualities, which were subjected to a bioguided fractionation. Among the isolated metabolites [moracins M (1), O/P (2), kuwanon L (3), and sanggenons D (4), B (5), G (6), O (7), E (8), and C (9)] all the Diels-Alder adducts (3-9) showed an antifungal activity with IC50 values between 10 and 123 microM. The in vitro activity of the most active fraction (A5, IC50 39.0 +/- 4.2 microg/mL) was evaluated in vivo, confirming a distinct antifungal activity against V. inaequalis for the tested natural material.


Assuntos
Antifúngicos/isolamento & purificação , Antifúngicos/farmacologia , Ascomicetos/efeitos dos fármacos , Morus/química , Casca de Planta/química , Raízes de Plantas/química , Antifúngicos/química , Cromatografia Líquida de Alta Pressão , Estrutura Molecular , Plantas Medicinais/química
16.
Nat Neurosci ; 8(9): 1241-7, 2005 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16116442

RESUMO

The relative pitch of harmonic complex sounds, such as instrumental sounds, may be perceived by decoding either the fundamental pitch (f0) or the spectral pitch (fSP) of the stimuli. We classified a large cohort of 420 subjects including symphony orchestra musicians to be either f0 or fSP listeners, depending on the dominant perceptual mode. In a subgroup of 87 subjects, MRI (magnetic resonance imaging) and magnetoencephalography studies demonstrated a strong neural basis for both types of pitch perception irrespective of musical aptitude. Compared with f0 listeners, fSP listeners possessed a pronounced rightward, rather than leftward, asymmetry of gray matter volume and P50m activity within the pitch-sensitive lateral Heschl's gyrus. Our data link relative hemispheric lateralization with perceptual stimulus properties, whereas the absolute size of the Heschl's gyrus depends on musical aptitude.


Assuntos
Aptidão/fisiologia , Córtex Auditivo/fisiologia , Mapeamento Encefálico , Lateralidade Funcional/fisiologia , Música , Percepção da Altura Sonora/fisiologia , Estimulação Acústica/métodos , Feminino , Humanos , Imageamento Tridimensional/métodos , Imageamento por Ressonância Magnética/métodos , Magnetoencefalografia/métodos , Masculino , Psicometria
17.
Ann N Y Acad Sci ; 1060: 387-94, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16597790

RESUMO

The musical pitch of harmonic complex sounds, such as instrumental sounds, is perceived primarily by decoding either the fundamental pitch (keynote) or spectral aspects of the stimuli, for example, single harmonics. We divided 334 professional musicians, including symphony orchestra musicians, 75 amateur musicians, and 54 nonmusicians, into either fundamental pitch listeners or spectral pitch listeners. We observed a strong correlation between pitch perception preference and asymmetry of brain structure and function in the pitch-sensitive lateral areas of Heschl's gyrus (HG), irrespective of musical ability. In particular, fundamental pitch listeners exhibited both larger gray matter volume measured using magnetic resonance imaging (MRI) and enhanced P50m activity measured using magnetoencephalography (MEG) in the left lateral HG, which is sensitive to rapid temporal processing. Their chosen instruments were percussive or high-pitched instruments that produce short, sharp, or impulsive tones (e.g., drums, guitar, piano, trumpet, or flute). By contrast, spectral pitch listeners exhibited a dominant right lateral HG, which is known to be sensitive to slower temporal and spectral processing. Their chosen instruments were lower-pitched melodic instruments that produce rather sustained tones with characteristic changes in timbre (e.g., bassoon, saxophone, french horn, violoncello, or organ). Singers also belonged to the spectral pitch listeners. Furthermore, the absolute size of the neural HG substrate depended strongly on musical ability. Overall, it is likely that both magnitude and asymmetry of lateral HG, and the related perceptual mode, may have an impact on preference for particular musical instruments and on musical performance.


Assuntos
Música , Percepção da Altura Sonora , Psicoacústica , Estimulação Acústica , Aptidão , Percepção Auditiva , Encéfalo/anatomia & histologia , Mapeamento Encefálico , Comportamento de Escolha , Humanos , Imageamento por Ressonância Magnética , Magnetoencefalografia , Discriminação da Altura Tonal
18.
Nutr Cancer ; 42(1): 117-24, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-12235643

RESUMO

Hepatocytes freshly isolated from male Wistar rats fed a common diet or a vitamin A- or vitamin E-supplemented diet (each for 21, 28, or 41 days) were assayed for sensitivity to DNA breakage and cytogenetic changes induced by carcinogens. Different indirectly acting carcinogens were assayed. N-nitrosomorpholine (NMOR) was the only agent that induced DNA breaks, chromosomal aberrations, and micronuclei in all experiments. Benzo[a]pyrene (B[a]p) and dimethyldibenzo [c,g]carbazole (diMeDBC) induced only DNA breaks in all experiments. Occasionally, B[a]P induced chromosomal aberrations and micronuclei, and diMeDBC induced micronuclei, but not chromosomal aberrations. These results demonstrated that the tested carcinogens assayed at concentrations highly effective in a hypoxanthine phosphoribosyltransferase/V79 system significantly increased DNA damage, while cytogenetic changes were less frequent. In hepatocytes from rats fed vitamin A, a reduction in the severity of all three end points was observed after NMOR treatment. After B[a]P treatment, we found a reduction in DNA breaks and chromosomal aberrations; after treatment with diMeDBC, we observed a reduction in DNA breaks. Treatment with vitamin E was less effective: it reduced DNA strand breaks induced by B[a]P and partially reduced those induced by diMeDBC and NMOR and the level of micronuclei induced by NMOR and B[a]P. Both vitamins reduced the level of DNA strand breaks induced by the oxidative effect of a visible light-excited photosensitizer.


Assuntos
Carcinógenos/toxicidade , Aberrações Cromossômicas , Dano ao DNA/efeitos dos fármacos , Hepatócitos/efeitos dos fármacos , Micronúcleos com Defeito Cromossômico/efeitos dos fármacos , Vitamina A/administração & dosagem , Vitamina E/administração & dosagem , Animais , Benzo(a)pireno/toxicidade , Carbazóis/toxicidade , Células Cultivadas , Hepatócitos/ultraestrutura , Masculino , Nitrosaminas/toxicidade , Ratos , Ratos Wistar
19.
Nat Neurosci ; 5(7): 688-94, 2002 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12068300

RESUMO

Using magnetoencephalography (MEG), we compared the processing of sinusoidal tones in the auditory cortex of 12 non-musicians, 12 professional musicians and 13 amateur musicians. We found neurophysiological and anatomical differences between groups. In professional musicians as compared to non-musicians, the activity evoked in primary auditory cortex 19-30 ms after stimulus onset was 102% larger, and the gray matter volume of the anteromedial portion of Heschl's gyrus was 130% larger. Both quantities were highly correlated with musical aptitude, as measured by psychometric evaluation. These results indicate that both the morphology and neurophysiology of Heschl's gyrus have an essential impact on musical aptitude.


Assuntos
Aptidão/fisiologia , Música , Lobo Temporal/anatomia & histologia , Lobo Temporal/fisiologia , Estimulação Acústica , Adulto , Córtex Auditivo/anatomia & histologia , Córtex Auditivo/fisiologia , Potenciais Evocados Auditivos/fisiologia , Feminino , Humanos , Imageamento por Ressonância Magnética , Magnetoencefalografia , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes
20.
Eur J Endocrinol ; 146(2): 215-22, 2002 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11834431

RESUMO

OBJECTIVE: Standard treatment in hypoparathyroidism consists of calcium and vitamin D (or vitamin D analogs) but does not employ replacement of the actual missing hormone. Only few studies have evaluated the efficacy of calcium/vitamin D treatment in hypoparathyroidism; the impact of chronic hypoparathyroid disease on well-being has not been investigated previously. DESIGN: Cross-sectional, controlled study in 25 unselected women with postsurgical hypoparathyroidism since 6.4plus minus8.0 years (s.d.) on stable treatment with calcium and vitamin D (or analogs) and in 25 controls with a history of thyroid surgery but intact parathyroid function, who were matched for sex, age and time since surgery. METHODS: Assessment of well-being and mood using validated questionnaires (the revised version Symptom Checklist 90 (SCL-90-R); the Giessen Complaint List (GBB-24); and the von Zerssen Symptom List (B-L Zerssen)), serum and urinary calcium/phosphorus homeostasis, and in the hypoparathyroid patients also screening for secondary disease by kidney ultrasound, ophthalmological split lamp examination, and measurement of bone mineral density. RESULTS: Serum calcium was in the accepted therapeutic range in the majority of hypoparathyroid patients. However, calcium/phosphorus homeostasis as a whole was clearly non-physiological. Nephrolithiasis was detected in 2 and cataracts in 11 of 25 hypoparathyroid patients. As compared with controls, hypoparathyroid patients had significantly higher global complaint scores in GBB-24 (P=0.036), B-L Zerssen (P=0.002) and SCL-90-R (P=0.020) with predominant increases in the subscale scores for anxiety, phobic anxiety and their physical equivalents. CONCLUSIONS: Current standard treatment in hypoparathyroidism is not only associated with an altered calcium/phosphorus homeostasis but also fails to restore well-being in these patients. Future studies need to address the impact of more physiological treatment options like parathyroid hormone(1-34) or parathyroid transplantation on well-being and mood in these patients.


Assuntos
Afeto , Cálcio/metabolismo , Cálcio/uso terapêutico , Homeostase , Hipoparatireoidismo/tratamento farmacológico , Qualidade de Vida , Vitamina D/uso terapêutico , Adulto , Idoso , Ansiedade , Cálcio/sangue , Cálcio/urina , Catarata/complicações , Feminino , Humanos , Hipoparatireoidismo/metabolismo , Hipoparatireoidismo/psicologia , Cálculos Renais/complicações , Pessoa de Meia-Idade , Fósforo/sangue , Valores de Referência , Inquéritos e Questionários
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA